[multiple changes]

[thirdparty/gcc.git] / gcc / ada / exp_ch9.adb

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                              E X P _ C H 9                               --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with Atree;    use Atree;
with Checks;   use Checks;
with Einfo;    use Einfo;
with Elists;   use Elists;
with Errout;   use Errout;
with Exp_Ch3;  use Exp_Ch3;
with Exp_Ch6;  use Exp_Ch6;
with Exp_Ch11; use Exp_Ch11;
with Exp_Dbug; use Exp_Dbug;
with Exp_Disp; use Exp_Disp;
with Exp_Sel;  use Exp_Sel;
with Exp_Smem; use Exp_Smem;
with Exp_Tss;  use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze;   use Freeze;
with Hostparm;
with Itypes;   use Itypes;
with Namet;    use Namet;
with Nlists;   use Nlists;
with Nmake;    use Nmake;
with Opt;      use Opt;
with Restrict; use Restrict;
with Rident;   use Rident;
with Rtsfind;  use Rtsfind;
with Sem;      use Sem;
with Sem_Aux;  use Sem_Aux;
with Sem_Ch6;  use Sem_Ch6;
with Sem_Ch8;  use Sem_Ch8;
with Sem_Ch9;  use Sem_Ch9;
with Sem_Ch11; use Sem_Ch11;
with Sem_Elab; use Sem_Elab;
with Sem_Eval; use Sem_Eval;
with Sem_Res;  use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo;    use Sinfo;
with Snames;   use Snames;
with Stand;    use Stand;
with Targparm; use Targparm;
with Tbuild;   use Tbuild;
with Uintp;    use Uintp;

package body Exp_Ch9 is

   --  The following constant establishes the upper bound for the index of
   --  an entry family. It is used to limit the allocated size of protected
   --  types with defaulted discriminant of an integer type, when the bound
   --  of some entry family depends on a discriminant. The limitation to entry
   --  families of 128K should be reasonable in all cases, and is a documented
   --  implementation restriction.

   Entry_Family_Bound : constant Pos := 2**16;

   -----------------------
   -- Local Subprograms --
   -----------------------

   function Actual_Index_Expression
     (Sloc  : Source_Ptr;
      Ent   : Entity_Id;
      Index : Node_Id;
      Tsk   : Entity_Id) return Node_Id;
   --  Compute the index position for an entry call. Tsk is the target task. If
   --  the bounds of some entry family depend on discriminants, the expression
   --  computed by this function uses the discriminants of the target task.

   procedure Add_Object_Pointer
     (Loc      : Source_Ptr;
      Conc_Typ : Entity_Id;
      Decls    : List_Id);
   --  Prepend an object pointer declaration to the declaration list Decls.
   --  This object pointer is initialized to a type conversion of the System.
   --  Address pointer passed to entry barrier functions and entry body
   --  procedures.

   procedure Add_Formal_Renamings
     (Spec  : Node_Id;
      Decls : List_Id;
      Ent   : Entity_Id;
      Loc   : Source_Ptr);
   --  Create renaming declarations for the formals, inside the procedure that
   --  implements an entry body. The renamings make the original names of the
   --  formals accessible to gdb, and serve no other purpose.
   --    Spec is the specification of the procedure being built.
   --    Decls is the list of declarations to be enhanced.
   --    Ent is the entity for the original entry body.

   function Build_Accept_Body (Astat : Node_Id) return Node_Id;
   --  Transform accept statement into a block with added exception handler.
   --  Used both for simple accept statements and for accept alternatives in
   --  select statements. Astat is the accept statement.

   function Build_Barrier_Function
     (N   : Node_Id;
      Ent : Entity_Id;
      Pid : Node_Id) return Node_Id;
   --  Build the function body returning the value of the barrier expression
   --  for the specified entry body.

   function Build_Barrier_Function_Specification
     (Loc    : Source_Ptr;
      Def_Id : Entity_Id) return Node_Id;
   --  Build a specification for a function implementing the protected entry
   --  barrier of the specified entry body.

   procedure Build_Contract_Wrapper (E : Entity_Id; Decl : Node_Id);
   --  Build the body of a wrapper procedure for an entry or entry family that
   --  has contract cases, preconditions, or postconditions. The body gathers
   --  the executable contract items and expands them in the usual way, and
   --  performs the entry call itself. This way preconditions are evaluated
   --  before the call is queued. E is the entry in question, and Decl is the
   --  enclosing synchronized type declaration at whose freeze point the
   --  generated body is analyzed.

   function Build_Corresponding_Record
     (N    : Node_Id;
      Ctyp : Node_Id;
      Loc  : Source_Ptr) return Node_Id;
   --  Common to tasks and protected types. Copy discriminant specifications,
   --  build record declaration. N is the type declaration, Ctyp is the
   --  concurrent entity (task type or protected type).

   function Build_Dispatching_Tag_Check
     (K : Entity_Id;
      N : Node_Id) return Node_Id;
   --  Utility to create the tree to check whether the dispatching call in
   --  a timed entry call, a conditional entry call, or an asynchronous
   --  transfer of control is a call to a primitive of a non-synchronized type.
   --  K is the temporary that holds the tagged kind of the target object, and
   --  N is the enclosing construct.

   function Build_Entry_Count_Expression
     (Concurrent_Type : Node_Id;
      Component_List  : List_Id;
      Loc             : Source_Ptr) return Node_Id;
   --  Compute number of entries for concurrent object. This is a count of
   --  simple entries, followed by an expression that computes the length
   --  of the range of each entry family. A single array with that size is
   --  allocated for each concurrent object of the type.

   function Build_Find_Body_Index (Typ : Entity_Id) return Node_Id;
   --  Build the function that translates the entry index in the call
   --  (which depends on the size of entry families) into an index into the
   --  Entry_Bodies_Array, to determine the body and barrier function used
   --  in a protected entry call. A pointer to this function appears in every
   --  protected object.

   function Build_Find_Body_Index_Spec (Typ : Entity_Id) return Node_Id;
   --  Build subprogram declaration for previous one

   function Build_Lock_Free_Protected_Subprogram_Body
     (N           : Node_Id;
      Prot_Typ    : Node_Id;
      Unprot_Spec : Node_Id) return Node_Id;
   --  N denotes a subprogram body of protected type Prot_Typ. Unprot_Spec is
   --  the subprogram specification of the unprotected version of N. Transform
   --  N such that it invokes the unprotected version of the body.

   function Build_Lock_Free_Unprotected_Subprogram_Body
     (N        : Node_Id;
      Prot_Typ : Node_Id) return Node_Id;
   --  N denotes a subprogram body of protected type Prot_Typ. Build a version
   --  of N where the original statements of N are synchronized through atomic
   --  actions such as compare and exchange. Prior to invoking this routine, it
   --  has been established that N can be implemented in a lock-free fashion.

   function Build_Parameter_Block
     (Loc     : Source_Ptr;
      Actuals : List_Id;
      Formals : List_Id;
      Decls   : List_Id) return Entity_Id;
   --  Generate an access type for each actual parameter in the list Actuals.
   --  Create an encapsulating record that contains all the actuals and return
   --  its type. Generate:
   --    type Ann1 is access all <actual1-type>
   --    ...
   --    type AnnN is access all <actualN-type>
   --    type Pnn is record
   --       <formal1> : Ann1;
   --       ...
   --       <formalN> : AnnN;
   --    end record;

   function Build_Protected_Entry
     (N   : Node_Id;
      Ent : Entity_Id;
      Pid : Node_Id) return Node_Id;
   --  Build the procedure implementing the statement sequence of the specified
   --  entry body.

   function Build_Protected_Entry_Specification
     (Loc    : Source_Ptr;
      Def_Id : Entity_Id;
      Ent_Id : Entity_Id) return Node_Id;
   --  Build a specification for the procedure implementing the statements of
   --  the specified entry body. Add attributes associating it with the entry
   --  defining identifier Ent_Id.

   function Build_Protected_Spec
     (N           : Node_Id;
      Obj_Type    : Entity_Id;
      Ident       : Entity_Id;
      Unprotected : Boolean := False) return List_Id;
   --  Utility shared by Build_Protected_Sub_Spec and Expand_Access_Protected_
   --  Subprogram_Type. Builds signature of protected subprogram, adding the
   --  formal that corresponds to the object itself. For an access to protected
   --  subprogram, there is no object type to specify, so the parameter has
   --  type Address and mode In. An indirect call through such a pointer will
   --  convert the address to a reference to the actual object. The object is
   --  a limited record and therefore a by_reference type.

   function Build_Protected_Subprogram_Body
     (N         : Node_Id;
      Pid       : Node_Id;
      N_Op_Spec : Node_Id) return Node_Id;
   --  This function is used to construct the protected version of a protected
   --  subprogram. Its statement sequence first defers abort, then locks the
   --  associated protected object, and then enters a block that contains a
   --  call to the unprotected version of the subprogram (for details, see
   --  Build_Unprotected_Subprogram_Body). This block statement requires a
   --  cleanup handler that unlocks the object in all cases. For details,
   --  see Exp_Ch7.Expand_Cleanup_Actions.

   function Build_Renamed_Formal_Declaration
     (New_F          : Entity_Id;
      Formal         : Entity_Id;
      Comp           : Entity_Id;
      Renamed_Formal : Node_Id) return Node_Id;
   --  Create a renaming declaration for a formal, within a protected entry
   --  body or an accept body. The renamed object is a component of the
   --  parameter block that is a parameter in the entry call.
   --
   --  In Ada 2012, if the formal is an incomplete tagged type, the renaming
   --  does not dereference the corresponding component to prevent an illegal
   --  use of the incomplete type (AI05-0151).

   function Build_Selected_Name
     (Prefix      : Entity_Id;
      Selector    : Entity_Id;
      Append_Char : Character := ' ') return Name_Id;
   --  Build a name in the form of Prefix__Selector, with an optional character
   --  appended. This is used for internal subprograms generated for operations
   --  of protected types, including barrier functions. For the subprograms
   --  generated for entry bodies and entry barriers, the generated name
   --  includes a sequence number that makes names unique in the presence of
   --  entry overloading. This is necessary because entry body procedures and
   --  barrier functions all have the same signature.

   procedure Build_Simple_Entry_Call
     (N       : Node_Id;
      Concval : Node_Id;
      Ename   : Node_Id;
      Index   : Node_Id);
   --  Some comments here would be useful ???

   function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id;
   --  This routine constructs a specification for the procedure that we will
   --  build for the task body for task type T. The spec has the form:
   --
   --    procedure tnameB (_Task : access tnameV);
   --
   --  where name is the character name taken from the task type entity that
   --  is passed as the argument to the procedure, and tnameV is the task
   --  value type that is associated with the task type.

   function Build_Unprotected_Subprogram_Body
     (N   : Node_Id;
      Pid : Node_Id) return Node_Id;
   --  This routine constructs the unprotected version of a protected
   --  subprogram body, which is contains all of the code in the original,
   --  unexpanded body. This is the version of the protected subprogram that is
   --  called from all protected operations on the same object, including the
   --  protected version of the same subprogram.

   procedure Build_Wrapper_Bodies
     (Loc : Source_Ptr;
      Typ : Entity_Id;
      N   : Node_Id);
   --  Ada 2005 (AI-345): Typ is either a concurrent type or the corresponding
   --  record of a concurrent type. N is the insertion node where all bodies
   --  will be placed. This routine builds the bodies of the subprograms which
   --  serve as an indirection mechanism to overriding primitives of concurrent
   --  types, entries and protected procedures. Any new body is analyzed.

   procedure Build_Wrapper_Specs
     (Loc : Source_Ptr;
      Typ : Entity_Id;
      N   : in out Node_Id);
   --  Ada 2005 (AI-345): Typ is either a concurrent type or the corresponding
   --  record of a concurrent type. N is the insertion node where all specs
   --  will be placed. This routine builds the specs of the subprograms which
   --  serve as an indirection mechanism to overriding primitives of concurrent
   --  types, entries and protected procedures. Any new spec is analyzed.

   procedure Collect_Entry_Families
     (Loc          : Source_Ptr;
      Cdecls       : List_Id;
      Current_Node : in out Node_Id;
      Conctyp      : Entity_Id);
   --  For each entry family in a concurrent type, create an anonymous array
   --  type of the right size, and add a component to the corresponding_record.

   function Concurrent_Object
     (Spec_Id  : Entity_Id;
      Conc_Typ : Entity_Id) return Entity_Id;
   --  Given a subprogram entity Spec_Id and concurrent type Conc_Typ, return
   --  the entity associated with the concurrent object in the Protected_Body_
   --  Subprogram or the Task_Body_Procedure of Spec_Id. The returned entity
   --  denotes formal parameter _O, _object or _task.

   function Copy_Result_Type (Res : Node_Id) return Node_Id;
   --  Copy the result type of a function specification, when building the
   --  internal operation corresponding to a protected function, or when
   --  expanding an access to protected function. If the result is an anonymous
   --  access to subprogram itself, we need to create a new signature with the
   --  same parameter names and the same resolved types, but with new entities
   --  for the formals.

   procedure Debug_Private_Data_Declarations (Decls : List_Id);
   --  Decls is a list which may contain the declarations created by Install_
   --  Private_Data_Declarations. All generated entities are marked as needing
   --  debug info and debug nodes are manually generation where necessary. This
   --  step of the expansion must to be done after private data has been moved
   --  to its final resting scope to ensure proper visibility of debug objects.

   procedure Ensure_Statement_Present (Loc : Source_Ptr; Alt : Node_Id);
   --  If control flow optimizations are suppressed, and Alt is an accept,
   --  delay, or entry call alternative with no trailing statements, insert
   --  a null trailing statement with the given Loc (which is the sloc of
   --  the accept, delay, or entry call statement). There might not be any
   --  generated code for the accept, delay, or entry call itself (the effect
   --  of these statements is part of the general processsing done for the
   --  enclosing selective accept, timed entry call, or asynchronous select),
   --  and the null statement is there to carry the sloc of that statement to
   --  the back-end for trace-based coverage analysis purposes.

   procedure Extract_Dispatching_Call
     (N        : Node_Id;
      Call_Ent : out Entity_Id;
      Object   : out Entity_Id;
      Actuals  : out List_Id;
      Formals  : out List_Id);
   --  Given a dispatching call, extract the entity of the name of the call,
   --  its actual dispatching object, its actual parameters and the formal
   --  parameters of the overridden interface-level version. If the type of
   --  the dispatching object is an access type then an explicit dereference
   --  is returned in Object.

   procedure Extract_Entry
     (N       : Node_Id;
      Concval : out Node_Id;
      Ename   : out Node_Id;
      Index   : out Node_Id);
   --  Given an entry call, returns the associated concurrent object, the entry
   --  name, and the entry family index.

   function Family_Offset
     (Loc  : Source_Ptr;
      Hi   : Node_Id;
      Lo   : Node_Id;
      Ttyp : Entity_Id;
      Cap  : Boolean) return Node_Id;
   --  Compute (Hi - Lo) for two entry family indexes. Hi is the index in an
   --  accept statement, or the upper bound in the discrete subtype of an entry
   --  declaration. Lo is the corresponding lower bound. Ttyp is the concurrent
   --  type of the entry. If Cap is true, the result is capped according to
   --  Entry_Family_Bound.

   function Family_Size
     (Loc  : Source_Ptr;
      Hi   : Node_Id;
      Lo   : Node_Id;
      Ttyp : Entity_Id;
      Cap  : Boolean) return Node_Id;
   --  Compute (Hi - Lo) + 1 Max 0, to determine the number of entries in a
   --  family, and handle properly the superflat case. This is equivalent to
   --  the use of 'Length on the index type, but must use Family_Offset to
   --  handle properly the case of bounds that depend on discriminants. If
   --  Cap is true, the result is capped according to Entry_Family_Bound.

   procedure Find_Enclosing_Context
     (N             : Node_Id;
      Context       : out Node_Id;
      Context_Id    : out Entity_Id;
      Context_Decls : out List_Id);
   --  Subsidiary routine to procedures Build_Activation_Chain_Entity and
   --  Build_Master_Entity. Given an arbitrary node in the tree, find the
   --  nearest enclosing body, block, package, or return statement and return
   --  its constituents. Context is the enclosing construct, Context_Id is
   --  the scope of Context_Id and Context_Decls is the declarative list of
   --  Context.

   function Index_Object (Spec_Id : Entity_Id) return Entity_Id;
   --  Given a subprogram identifier, return the entity which is associated
   --  with the protection entry index in the Protected_Body_Subprogram or
   --  the Task_Body_Procedure of Spec_Id. The returned entity denotes formal
   --  parameter _E.

   function Is_Exception_Safe (Subprogram : Node_Id) return Boolean;
   --  Tell whether a given subprogram cannot raise an exception

   function Is_Potentially_Large_Family
     (Base_Index : Entity_Id;
      Conctyp    : Entity_Id;
      Lo         : Node_Id;
      Hi         : Node_Id) return Boolean;

   function Is_Private_Primitive_Subprogram (Id : Entity_Id) return Boolean;
   --  Determine whether Id is a function or a procedure and is marked as a
   --  private primitive.

   function Null_Statements (Stats : List_Id) return Boolean;
   --  Used to check DO-END sequence. Checks for equivalent of DO NULL; END.
   --  Allows labels, and pragma Warnings/Unreferenced in the sequence as well
   --  to still count as null. Returns True for a null sequence. The argument
   --  is the list of statements from the DO-END sequence.

   function Parameter_Block_Pack
     (Loc     : Source_Ptr;
      Blk_Typ : Entity_Id;
      Actuals : List_Id;
      Formals : List_Id;
      Decls   : List_Id;
      Stmts   : List_Id) return Entity_Id;
   --  Set the components of the generated parameter block with the values
   --  of the actual parameters. Generate aliased temporaries to capture the
   --  values for types that are passed by copy. Otherwise generate a reference
   --  to the actual's value. Return the address of the aggregate block.
   --  Generate:
   --    Jnn1 : alias <formal-type1>;
   --    Jnn1 := <actual1>;
   --    ...
   --    P : Blk_Typ := (
   --      Jnn1'unchecked_access;
   --      <actual2>'reference;
   --      ...);

   function Parameter_Block_Unpack
     (Loc     : Source_Ptr;
      P       : Entity_Id;
      Actuals : List_Id;
      Formals : List_Id) return List_Id;
   --  Retrieve the values of the components from the parameter block and
   --  assign then to the original actual parameters. Generate:
   --    <actual1> := P.<formal1>;
   --    ...
   --    <actualN> := P.<formalN>;

   function Trivial_Accept_OK return Boolean;
   --  If there is no DO-END block for an accept, or if the DO-END block has
   --  only null statements, then it is possible to do the Rendezvous with much
   --  less overhead using the Accept_Trivial routine in the run-time library.
   --  However, this is not always a valid optimization. Whether it is valid or
   --  not depends on the Task_Dispatching_Policy. The issue is whether a full
   --  rescheduling action is required or not. In FIFO_Within_Priorities, such
   --  a rescheduling is required, so this optimization is not allowed. This
   --  function returns True if the optimization is permitted.

   -----------------------------
   -- Actual_Index_Expression --
   -----------------------------

   function Actual_Index_Expression
     (Sloc  : Source_Ptr;
      Ent   : Entity_Id;
      Index : Node_Id;
      Tsk   : Entity_Id) return Node_Id
   is
      Ttyp : constant Entity_Id := Etype (Tsk);
      Expr : Node_Id;
      Num  : Node_Id;
      Lo   : Node_Id;
      Hi   : Node_Id;
      Prev : Entity_Id;
      S    : Node_Id;

      function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id;
      --  Compute difference between bounds of entry family

      --------------------------
      -- Actual_Family_Offset --
      --------------------------

      function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id is

         function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
         --  Replace a reference to a discriminant with a selected component
         --  denoting the discriminant of the target task.

         -----------------------------
         -- Actual_Discriminant_Ref --
         -----------------------------

         function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
            Typ : constant Entity_Id := Etype (Bound);
            B   : Node_Id;

         begin
            if not Is_Entity_Name (Bound)
              or else Ekind (Entity (Bound)) /= E_Discriminant
            then
               if Nkind (Bound) = N_Attribute_Reference then
                  return Bound;
               else
                  B := New_Copy_Tree (Bound);
               end if;

            else
               B :=
                 Make_Selected_Component (Sloc,
                   Prefix        => New_Copy_Tree (Tsk),
                   Selector_Name => New_Occurrence_Of (Entity (Bound), Sloc));

               Analyze_And_Resolve (B, Typ);
            end if;

            return
              Make_Attribute_Reference (Sloc,
                Attribute_Name => Name_Pos,
                Prefix         => New_Occurrence_Of (Etype (Bound), Sloc),
                Expressions    => New_List (B));
         end Actual_Discriminant_Ref;

      --  Start of processing for Actual_Family_Offset

      begin
         return
           Make_Op_Subtract (Sloc,
             Left_Opnd  => Actual_Discriminant_Ref (Hi),
             Right_Opnd => Actual_Discriminant_Ref (Lo));
      end Actual_Family_Offset;

   --  Start of processing for Actual_Index_Expression

   begin
      --  The queues of entries and entry families appear in textual order in
      --  the associated record. The entry index is computed as the sum of the
      --  number of queues for all entries that precede the designated one, to
      --  which is added the index expression, if this expression denotes a
      --  member of a family.

      --  The following is a place holder for the count of simple entries

      Num := Make_Integer_Literal (Sloc, 1);

      --  We construct an expression which is a series of addition operations.
      --  See comments in Entry_Index_Expression, which is identical in
      --  structure.

      if Present (Index) then
         S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent)));

         Expr :=
           Make_Op_Add (Sloc,
             Left_Opnd  => Num,
             Right_Opnd =>
               Actual_Family_Offset (
                 Make_Attribute_Reference (Sloc,
                   Attribute_Name => Name_Pos,
                   Prefix => New_Occurrence_Of (Base_Type (S), Sloc),
                   Expressions => New_List (Relocate_Node (Index))),
                 Type_Low_Bound (S)));
      else
         Expr := Num;
      end if;

      --  Now add lengths of preceding entries and entry families

      Prev := First_Entity (Ttyp);
      while Chars (Prev) /= Chars (Ent)
        or else (Ekind (Prev) /= Ekind (Ent))
        or else not Sem_Ch6.Type_Conformant (Ent, Prev)
      loop
         if Ekind (Prev) = E_Entry then
            Set_Intval (Num, Intval (Num) + 1);

         elsif Ekind (Prev) = E_Entry_Family then
            S :=
              Etype (Discrete_Subtype_Definition (Declaration_Node (Prev)));

            --  The need for the following full view retrieval stems from this
            --  complex case of nested generics and tasking:

            --     generic
            --        type Formal_Index is range <>;
            --        ...
            --     package Outer is
            --        type Index is private;
            --        generic
            --           ...
            --        package Inner is
            --           procedure P;
            --        end Inner;
            --     private
            --        type Index is new Formal_Index range 1 .. 10;
            --     end Outer;

            --     package body Outer is
            --        task type T is
            --           entry Fam (Index);  --  (2)
            --           entry E;
            --        end T;
            --        package body Inner is  --  (3)
            --           procedure P is
            --           begin
            --              T.E;             --  (1)
            --           end P;
            --       end Inner;
            --       ...

            --  We are currently building the index expression for the entry
            --  call "T.E" (1). Part of the expansion must mention the range
            --  of the discrete type "Index" (2) of entry family "Fam".

            --  However only the private view of type "Index" is available to
            --  the inner generic (3) because there was no prior mention of
            --  the type inside "Inner". This visibility requirement is
            --  implicit and cannot be detected during the construction of
            --  the generic trees and needs special handling.

            if In_Instance_Body
              and then Is_Private_Type (S)
              and then Present (Full_View (S))
            then
               S := Full_View (S);
            end if;

            Lo := Type_Low_Bound  (S);
            Hi := Type_High_Bound (S);

            Expr :=
              Make_Op_Add (Sloc,
              Left_Opnd  => Expr,
              Right_Opnd =>
                Make_Op_Add (Sloc,
                  Left_Opnd  => Actual_Family_Offset (Hi, Lo),
                  Right_Opnd => Make_Integer_Literal (Sloc, 1)));

         --  Other components are anonymous types to be ignored

         else
            null;
         end if;

         Next_Entity (Prev);
      end loop;

      return Expr;
   end Actual_Index_Expression;

   --------------------------
   -- Add_Formal_Renamings --
   --------------------------

   procedure Add_Formal_Renamings
     (Spec  : Node_Id;
      Decls : List_Id;
      Ent   : Entity_Id;
      Loc   : Source_Ptr)
   is
      Ptr : constant Entity_Id :=
              Defining_Identifier
                (Next (First (Parameter_Specifications (Spec))));
      --  The name of the formal that holds the address of the parameter block
      --  for the call.

      Comp            : Entity_Id;
      Decl            : Node_Id;
      Formal          : Entity_Id;
      New_F           : Entity_Id;
      Renamed_Formal  : Node_Id;

   begin
      Formal := First_Formal (Ent);
      while Present (Formal) loop
         Comp := Entry_Component (Formal);
         New_F :=
           Make_Defining_Identifier (Sloc (Formal),
             Chars => Chars (Formal));
         Set_Etype (New_F, Etype (Formal));
         Set_Scope (New_F, Ent);

         --  Now we set debug info needed on New_F even though it does not come
         --  from source, so that the debugger will get the right information
         --  for these generated names.

         Set_Debug_Info_Needed (New_F);

         if Ekind (Formal) = E_In_Parameter then
            Set_Ekind (New_F, E_Constant);
         else
            Set_Ekind (New_F, E_Variable);
            Set_Extra_Constrained (New_F, Extra_Constrained (Formal));
         end if;

         Set_Actual_Subtype (New_F, Actual_Subtype (Formal));

         Renamed_Formal :=
           Make_Selected_Component (Loc,
             Prefix        =>
               Unchecked_Convert_To (Entry_Parameters_Type (Ent),
                 Make_Identifier (Loc, Chars (Ptr))),
             Selector_Name => New_Occurrence_Of (Comp, Loc));

         Decl :=
           Build_Renamed_Formal_Declaration
             (New_F, Formal, Comp, Renamed_Formal);

         Append (Decl, Decls);
         Set_Renamed_Object (Formal, New_F);
         Next_Formal (Formal);
      end loop;
   end Add_Formal_Renamings;

   ------------------------
   -- Add_Object_Pointer --
   ------------------------

   procedure Add_Object_Pointer
     (Loc      : Source_Ptr;
      Conc_Typ : Entity_Id;
      Decls    : List_Id)
   is
      Rec_Typ : constant Entity_Id := Corresponding_Record_Type (Conc_Typ);
      Decl    : Node_Id;
      Obj_Ptr : Node_Id;

   begin
      --  Create the renaming declaration for the Protection object of a
      --  protected type. _Object is used by Complete_Entry_Body.
      --  ??? An attempt to make this a renaming was unsuccessful.

      --  Build the entity for the access type

      Obj_Ptr :=
        Make_Defining_Identifier (Loc,
          New_External_Name (Chars (Rec_Typ), 'P'));

      --  Generate:
      --    _object : poVP := poVP!O;

      Decl :=
        Make_Object_Declaration (Loc,
          Defining_Identifier => Make_Defining_Identifier (Loc, Name_uObject),
          Object_Definition   => New_Occurrence_Of (Obj_Ptr, Loc),
          Expression          =>
            Unchecked_Convert_To (Obj_Ptr, Make_Identifier (Loc, Name_uO)));
      Set_Debug_Info_Needed (Defining_Identifier (Decl));
      Prepend_To (Decls, Decl);

      --  Generate:
      --    type poVP is access poV;

      Decl :=
        Make_Full_Type_Declaration (Loc,
          Defining_Identifier =>
            Obj_Ptr,
          Type_Definition =>
            Make_Access_To_Object_Definition (Loc,
              Subtype_Indication =>
                New_Occurrence_Of (Rec_Typ, Loc)));
      Set_Debug_Info_Needed (Defining_Identifier (Decl));
      Prepend_To (Decls, Decl);
   end Add_Object_Pointer;

   -----------------------
   -- Build_Accept_Body --
   -----------------------

   function Build_Accept_Body (Astat : Node_Id) return  Node_Id is
      Loc     : constant Source_Ptr := Sloc (Astat);
      Stats   : constant Node_Id    := Handled_Statement_Sequence (Astat);
      New_S   : Node_Id;
      Hand    : Node_Id;
      Call    : Node_Id;
      Ohandle : Node_Id;

   begin
      --  At the end of the statement sequence, Complete_Rendezvous is called.
      --  A label skipping the Complete_Rendezvous, and all other accept
      --  processing, has already been added for the expansion of requeue
      --  statements. The Sloc is copied from the last statement since it
      --  is really part of this last statement.

      Call :=
        Build_Runtime_Call
          (Sloc (Last (Statements (Stats))), RE_Complete_Rendezvous);
      Insert_Before (Last (Statements (Stats)), Call);
      Analyze (Call);

      --  If exception handlers are present, then append Complete_Rendezvous
      --  calls to the handlers, and construct the required outer block. As
      --  above, the Sloc is copied from the last statement in the sequence.

      if Present (Exception_Handlers (Stats)) then
         Hand := First (Exception_Handlers (Stats));
         while Present (Hand) loop
            Call :=
              Build_Runtime_Call
                (Sloc (Last (Statements (Hand))), RE_Complete_Rendezvous);
            Append (Call, Statements (Hand));
            Analyze (Call);
            Next (Hand);
         end loop;

         New_S :=
           Make_Handled_Sequence_Of_Statements (Loc,
             Statements => New_List (
               Make_Block_Statement (Loc,
                 Handled_Statement_Sequence => Stats)));

      else
         New_S := Stats;
      end if;

      --  At this stage we know that the new statement sequence does
      --  not have an exception handler part, so we supply one to call
      --  Exceptional_Complete_Rendezvous. This handler is

      --    when all others =>
      --       Exceptional_Complete_Rendezvous (Get_GNAT_Exception);

      --  We handle Abort_Signal to make sure that we properly catch the abort
      --  case and wake up the caller.

      Ohandle := Make_Others_Choice (Loc);
      Set_All_Others (Ohandle);

      Set_Exception_Handlers (New_S,
        New_List (
          Make_Implicit_Exception_Handler (Loc,
            Exception_Choices => New_List (Ohandle),

            Statements =>  New_List (
              Make_Procedure_Call_Statement (Sloc (Stats),
                Name                   => New_Occurrence_Of (
                  RTE (RE_Exceptional_Complete_Rendezvous), Sloc (Stats)),
                Parameter_Associations => New_List (
                  Make_Function_Call (Sloc (Stats),
                    Name =>
                      New_Occurrence_Of
                        (RTE (RE_Get_GNAT_Exception), Sloc (Stats)))))))));

      Set_Parent (New_S, Astat); -- temp parent for Analyze call
      Analyze_Exception_Handlers (Exception_Handlers (New_S));
      Expand_Exception_Handlers (New_S);

      --  Exceptional_Complete_Rendezvous must be called with abort still
      --  deferred, which is the case for a "when all others" handler.

      return New_S;
   end Build_Accept_Body;

   -----------------------------------
   -- Build_Activation_Chain_Entity --
   -----------------------------------

   procedure Build_Activation_Chain_Entity (N : Node_Id) is
      function Has_Activation_Chain (Stmt : Node_Id) return Boolean;
      --  Determine whether an extended return statement has activation chain

      --------------------------
      -- Has_Activation_Chain --
      --------------------------

      function Has_Activation_Chain (Stmt : Node_Id) return Boolean is
         Decl : Node_Id;

      begin
         Decl := First (Return_Object_Declarations (Stmt));
         while Present (Decl) loop
            if Nkind (Decl) = N_Object_Declaration
              and then Chars (Defining_Identifier (Decl)) = Name_uChain
            then
               return True;
            end if;

            Next (Decl);
         end loop;

         return False;
      end Has_Activation_Chain;

      --  Local variables

      Context    : Node_Id;
      Context_Id : Entity_Id;
      Decls      : List_Id;

   --  Start of processing for Build_Activation_Chain_Entity

   begin
      --  Activation chain is never used for sequential elaboration policy, see
      --  comment for Create_Restricted_Task_Sequential in s-tarest.ads).

      if Partition_Elaboration_Policy = 'S' then
         return;
      end if;

      Find_Enclosing_Context (N, Context, Context_Id, Decls);

      --  If activation chain entity has not been declared already, create one

      if Nkind (Context) = N_Extended_Return_Statement
        or else No (Activation_Chain_Entity (Context))
      then
         --  Since extended return statements do not store the entity of the
         --  chain, examine the return object declarations to avoid creating
         --  a duplicate.

         if Nkind (Context) = N_Extended_Return_Statement
           and then Has_Activation_Chain (Context)
         then
            return;
         end if;

         declare
            Loc   : constant Source_Ptr := Sloc (Context);
            Chain : Entity_Id;
            Decl  : Node_Id;

         begin
            Chain := Make_Defining_Identifier (Sloc (N), Name_uChain);

            --  Note: An extended return statement is not really a task
            --  activator, but it does have an activation chain on which to
            --  store the tasks temporarily. On successful return, the tasks
            --  on this chain are moved to the chain passed in by the caller.
            --  We do not build an Activation_Chain_Entity for an extended
            --  return statement, because we do not want to build a call to
            --  Activate_Tasks. Task activation is the responsibility of the
            --  caller.

            if Nkind (Context) /= N_Extended_Return_Statement then
               Set_Activation_Chain_Entity (Context, Chain);
            end if;

            Decl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => Chain,
                Aliased_Present     => True,
                Object_Definition   =>
                  New_Occurrence_Of (RTE (RE_Activation_Chain), Loc));

            Prepend_To (Decls, Decl);

            --  Ensure that _chain appears in the proper scope of the context

            if Context_Id /= Current_Scope then
               Push_Scope (Context_Id);
               Analyze (Decl);
               Pop_Scope;
            else
               Analyze (Decl);
            end if;
         end;
      end if;
   end Build_Activation_Chain_Entity;

   ----------------------------
   -- Build_Barrier_Function --
   ----------------------------

   function Build_Barrier_Function
     (N   : Node_Id;
      Ent : Entity_Id;
      Pid : Node_Id) return Node_Id
   is
      Ent_Formals : constant Node_Id    := Entry_Body_Formal_Part (N);
      Cond        : constant Node_Id    := Condition (Ent_Formals);
      Loc         : constant Source_Ptr := Sloc (Cond);
      Func_Id     : constant Entity_Id  := Barrier_Function (Ent);
      Op_Decls    : constant List_Id    := New_List;
      Stmt        : Node_Id;
      Func_Body   : Node_Id;

   begin
      --  Add a declaration for the Protection object, renaming declarations
      --  for the discriminals and privals and finally a declaration for the
      --  entry family index (if applicable).

      Install_Private_Data_Declarations (Sloc (N),
         Spec_Id  => Func_Id,
         Conc_Typ => Pid,
         Body_Nod => N,
         Decls    => Op_Decls,
         Barrier  => True,
         Family   => Ekind (Ent) = E_Entry_Family);

      --  If compiling with -fpreserve-control-flow, make sure we insert an
      --  IF statement so that the back-end knows to generate a conditional
      --  branch instruction, even if the condition is just the name of a
      --  boolean object. Note that Expand_N_If_Statement knows to preserve
      --  such redundant IF statements under -fpreserve-control-flow
      --  (whether coming from this routine, or directly from source).

      if Opt.Suppress_Control_Flow_Optimizations then
         Stmt :=
           Make_Implicit_If_Statement (Cond,
             Condition       => Cond,
             Then_Statements => New_List (
               Make_Simple_Return_Statement (Loc,
                 New_Occurrence_Of (Standard_True, Loc))),

             Else_Statements => New_List (
               Make_Simple_Return_Statement (Loc,
                 New_Occurrence_Of (Standard_False, Loc))));

      else
         Stmt := Make_Simple_Return_Statement (Loc, Cond);
      end if;

      --  Note: the condition in the barrier function needs to be properly
      --  processed for the C/Fortran boolean possibility, but this happens
      --  automatically since the return statement does this normalization.

      Func_Body :=
        Make_Subprogram_Body (Loc,
          Specification =>
            Build_Barrier_Function_Specification (Loc,
              Make_Defining_Identifier (Loc, Chars (Func_Id))),
          Declarations => Op_Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc,
              Statements => New_List (Stmt)));
      Set_Is_Entry_Barrier_Function (Func_Body);

      return Func_Body;
   end Build_Barrier_Function;

   ------------------------------------------
   -- Build_Barrier_Function_Specification --
   ------------------------------------------

   function Build_Barrier_Function_Specification
     (Loc    : Source_Ptr;
      Def_Id : Entity_Id) return Node_Id
   is
   begin
      Set_Debug_Info_Needed (Def_Id);

      return
        Make_Function_Specification (Loc,
          Defining_Unit_Name       => Def_Id,
          Parameter_Specifications => New_List (
            Make_Parameter_Specification (Loc,
              Defining_Identifier =>
                Make_Defining_Identifier (Loc, Name_uO),
              Parameter_Type      =>
                New_Occurrence_Of (RTE (RE_Address), Loc)),

            Make_Parameter_Specification (Loc,
              Defining_Identifier =>
                Make_Defining_Identifier (Loc, Name_uE),
              Parameter_Type      =>
                New_Occurrence_Of (RTE (RE_Protected_Entry_Index), Loc))),

          Result_Definition        =>
            New_Occurrence_Of (Standard_Boolean, Loc));
   end Build_Barrier_Function_Specification;

   --------------------------
   -- Build_Call_With_Task --
   --------------------------

   function Build_Call_With_Task
     (N : Node_Id;
      E : Entity_Id) return Node_Id
   is
      Loc : constant Source_Ptr := Sloc (N);
   begin
      return
        Make_Function_Call (Loc,
          Name                   => New_Occurrence_Of (E, Loc),
          Parameter_Associations => New_List (Concurrent_Ref (N)));
   end Build_Call_With_Task;

   -----------------------------
   -- Build_Class_Wide_Master --
   -----------------------------

   procedure Build_Class_Wide_Master (Typ : Entity_Id) is
      Loc          : constant Source_Ptr := Sloc (Typ);
      Master_Decl  : Node_Id;
      Master_Id    : Entity_Id;
      Master_Scope : Entity_Id;
      Name_Id      : Node_Id;
      Related_Node : Node_Id;
      Ren_Decl     : Node_Id;

   begin
      --  Nothing to do if there is no task hierarchy

      if Restriction_Active (No_Task_Hierarchy) then
         return;
      end if;

      --  Find the declaration that created the access type, which is either a
      --  type declaration, or an object declaration with an access definition,
      --  in which case the type is anonymous.

      if Is_Itype (Typ) then
         Related_Node := Associated_Node_For_Itype (Typ);
      else
         Related_Node := Parent (Typ);
      end if;

      Master_Scope := Find_Master_Scope (Typ);

      --  Nothing to do if the master scope already contains a _master entity.
      --  The only exception to this is the following scenario:

      --    Source_Scope
      --       Transient_Scope_1
      --          _master

      --       Transient_Scope_2
      --          use of master

      --  In this case the source scope is marked as having the master entity
      --  even though the actual declaration appears inside an inner scope. If
      --  the second transient scope requires a _master, it cannot use the one
      --  already declared because the entity is not visible.

      Name_Id     := Make_Identifier (Loc, Name_uMaster);
      Master_Decl := Empty;

      if not Has_Master_Entity (Master_Scope)
        or else No (Current_Entity_In_Scope (Name_Id))
      then
         begin
            Set_Has_Master_Entity (Master_Scope);

            --  Generate:
            --    _master : constant Integer := Current_Master.all;

            Master_Decl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc, Name_uMaster),
                Constant_Present    => True,
                Object_Definition   =>
                  New_Occurrence_Of (Standard_Integer, Loc),
                Expression          =>
                  Make_Explicit_Dereference (Loc,
                    New_Occurrence_Of (RTE (RE_Current_Master), Loc)));

            Insert_Action (Find_Hook_Context (Related_Node), Master_Decl);
            Analyze (Master_Decl);

            --  Mark the containing scope as a task master. Masters associated
            --  with return statements are already marked at this stage (see
            --  Analyze_Subprogram_Body).

            if Ekind (Current_Scope) /= E_Return_Statement then
               declare
                  Par : Node_Id := Related_Node;

               begin
                  while Nkind (Par) /= N_Compilation_Unit loop
                     Par := Parent (Par);

                     --  If we fall off the top, we are at the outer level,
                     --  and the environment task is our effective master,
                     --  so nothing to mark.

                     if Nkind_In (Par, N_Block_Statement,
                                       N_Subprogram_Body,
                                       N_Task_Body)
                     then
                        Set_Is_Task_Master (Par);
                        exit;
                     end if;
                  end loop;
               end;
            end if;
         end;
      end if;

      Master_Id :=
        Make_Defining_Identifier (Loc, New_External_Name (Chars (Typ), 'M'));

      --  Generate:
      --    typeMnn renames _master;

      Ren_Decl :=
        Make_Object_Renaming_Declaration (Loc,
          Defining_Identifier => Master_Id,
          Subtype_Mark        => New_Occurrence_Of (Standard_Integer, Loc),
          Name                => Name_Id);

      --  If the master is declared locally, add the renaming declaration
      --  immediately after it, to prevent access-before-elaboration in the
      --  back-end.

      if Present (Master_Decl) then
         Insert_After (Master_Decl, Ren_Decl);
         Analyze (Ren_Decl);

      else
         Insert_Action (Related_Node, Ren_Decl);
      end if;

      Set_Master_Id (Typ, Master_Id);
   end Build_Class_Wide_Master;

   ----------------------------
   -- Build_Contract_Wrapper --
   ----------------------------

   procedure Build_Contract_Wrapper (E : Entity_Id; Decl : Node_Id) is
      Conc_Typ : constant Entity_Id  := Scope (E);
      Loc      : constant Source_Ptr := Sloc (E);

      procedure Add_Discriminant_Renamings
        (Obj_Id : Entity_Id;
         Decls  : List_Id);
      --  Add renaming declarations for all discriminants of concurrent type
      --  Conc_Typ. Obj_Id is the entity of the wrapper formal parameter which
      --  represents the concurrent object.

      procedure Add_Matching_Formals
        (Formals : List_Id;
         Actuals : in out List_Id);
      --  Add formal parameters that match those of entry E to list Formals.
      --  The routine also adds matching actuals for the new formals to list
      --  Actuals.

      procedure Transfer_Pragma (Prag : Node_Id; To : in out List_Id);
      --  Relocate pragma Prag to list To. The routine creates a new list if
      --  To does not exist.

      --------------------------------
      -- Add_Discriminant_Renamings --
      --------------------------------

      procedure Add_Discriminant_Renamings
        (Obj_Id : Entity_Id;
         Decls  : List_Id)
      is
         Discr : Entity_Id;

      begin
         --  Inspect the discriminants of the concurrent type and generate a
         --  renaming for each one.

         if Has_Discriminants (Conc_Typ) then
            Discr := First_Discriminant (Conc_Typ);
            while Present (Discr) loop
               Prepend_To (Decls,
                 Make_Object_Renaming_Declaration (Loc,
                   Defining_Identifier =>
                     Make_Defining_Identifier (Loc, Chars (Discr)),
                   Subtype_Mark        =>
                     New_Occurrence_Of (Etype (Discr), Loc),
                   Name                =>
                     Make_Selected_Component (Loc,
                       Prefix        => New_Occurrence_Of (Obj_Id, Loc),
                       Selector_Name =>
                         Make_Identifier (Loc, Chars (Discr)))));

               Next_Discriminant (Discr);
            end loop;
         end if;
      end Add_Discriminant_Renamings;

      --------------------------
      -- Add_Matching_Formals --
      --------------------------

      procedure Add_Matching_Formals
        (Formals : List_Id;
         Actuals : in out List_Id)
      is
         Formal     : Entity_Id;
         New_Formal : Entity_Id;

      begin
         --  Inspect the formal parameters of the entry and generate a new
         --  matching formal with the same name for the wrapper. A reference
         --  to the new formal becomes an actual in the entry call.

         Formal := First_Formal (E);
         while Present (Formal) loop
            New_Formal := Make_Defining_Identifier (Loc, Chars (Formal));
            Append_To (Formals,
              Make_Parameter_Specification (Loc,
                Defining_Identifier => New_Formal,
                In_Present          => In_Present  (Parent (Formal)),
                Out_Present         => Out_Present (Parent (Formal)),
                Parameter_Type      =>
                  New_Occurrence_Of (Etype (Formal), Loc)));

            if No (Actuals) then
               Actuals := New_List;
            end if;

            Append_To (Actuals, New_Occurrence_Of (New_Formal, Loc));
            Next_Formal (Formal);
         end loop;
      end Add_Matching_Formals;

      ---------------------
      -- Transfer_Pragma --
      ---------------------

      procedure Transfer_Pragma (Prag : Node_Id; To : in out List_Id) is
         New_Prag : Node_Id;

      begin
         if No (To) then
            To := New_List;
         end if;

         New_Prag := Relocate_Node (Prag);

         Set_Analyzed (New_Prag, False);
         Append       (New_Prag, To);
      end Transfer_Pragma;

      --  Local variables

      Items      : constant Node_Id := Contract (E);
      Actuals    : List_Id := No_List;
      Call       : Node_Id;
      Call_Nam   : Node_Id;
      Decls      : List_Id := No_List;
      Formals    : List_Id;
      Has_Pragma : Boolean := False;
      Index_Id   : Entity_Id;
      Obj_Id     : Entity_Id;
      Prag       : Node_Id;
      Wrapper_Id : Entity_Id;

   --  Start of processing for Build_Contract_Wrapper

   begin
      --  This routine generates a specialized wrapper for a protected or task
      --  entry [family] which implements precondition/postcondition semantics.
      --  Preconditions and case guards of contract cases are checked before
      --  the protected action or rendezvous takes place. Postconditions and
      --  consequences of contract cases are checked after the protected action
      --  or rendezvous takes place. The structure of the generated wrapper is
      --  as follows:

      --    procedure Wrapper
      --      (Obj_Id    : Conc_Typ;    --  concurrent object
      --       [Index    : Index_Typ;]  --  index of entry family
      --       [Formal_1 : ...;         --  parameters of original entry
      --        Formal_N : ...])
      --    is
      --       [Discr_1 : ... renames Obj_Id.Discr_1;   --  discriminant
      --        Discr_N : ... renames Obj_Id.Discr_N;]  --  renamings

      --       <precondition checks>
      --       <case guard checks>

      --       procedure _Postconditions is
      --       begin
      --          <postcondition checks>
      --          <consequence checks>
      --       end _Postconditions;

      --    begin
      --       Entry_Call (Obj_Id, [Index,] [Formal_1, Formal_N]);
      --       _Postconditions;
      --    end Wrapper;

      --  Create the wrapper only when the entry has at least one executable
      --  contract item such as contract cases, precondition or postcondition.

      if Present (Items) then

         --  Inspect the list of pre/postconditions and transfer all available
         --  pragmas to the declarative list of the wrapper.

         Prag := Pre_Post_Conditions (Items);
         while Present (Prag) loop
            if Nam_In (Pragma_Name_Unmapped (Prag),
                       Name_Postcondition, Name_Precondition)
              and then Is_Checked (Prag)
            then
               Has_Pragma := True;
               Transfer_Pragma (Prag, To => Decls);
            end if;

            Prag := Next_Pragma (Prag);
         end loop;

         --  Inspect the list of test/contract cases and transfer only contract
         --  cases pragmas to the declarative part of the wrapper.

         Prag := Contract_Test_Cases (Items);
         while Present (Prag) loop
            if Pragma_Name (Prag) = Name_Contract_Cases
              and then Is_Checked (Prag)
            then
               Has_Pragma := True;
               Transfer_Pragma (Prag, To => Decls);
            end if;

            Prag := Next_Pragma (Prag);
         end loop;
      end if;

      --  The entry lacks executable contract items and a wrapper is not needed

      if not Has_Pragma then
         return;
      end if;

      --  Create the profile of the wrapper. The first formal parameter is the
      --  concurrent object.

      Obj_Id :=
        Make_Defining_Identifier (Loc,
          Chars => New_External_Name (Chars (Conc_Typ), 'A'));

      Formals := New_List (
        Make_Parameter_Specification (Loc,
          Defining_Identifier => Obj_Id,
          Out_Present         => True,
          In_Present          => True,
          Parameter_Type      => New_Occurrence_Of (Conc_Typ, Loc)));

      --  Construct the call to the original entry. The call will be gradually
      --  augmented with an optional entry index and extra parameters.

      Call_Nam :=
        Make_Selected_Component (Loc,
          Prefix        => New_Occurrence_Of (Obj_Id, Loc),
          Selector_Name => New_Occurrence_Of (E, Loc));

      --  When creating a wrapper for an entry family, the second formal is the
      --  entry index.

      if Ekind (E) = E_Entry_Family then
         Index_Id := Make_Defining_Identifier (Loc, Name_I);

         Append_To (Formals,
           Make_Parameter_Specification (Loc,
             Defining_Identifier => Index_Id,
             Parameter_Type      =>
               New_Occurrence_Of (Entry_Index_Type (E), Loc)));

         --  The call to the original entry becomes an indexed component to
         --  accommodate the entry index.

         Call_Nam :=
           Make_Indexed_Component (Loc,
             Prefix      => Call_Nam,
             Expressions => New_List (New_Occurrence_Of (Index_Id, Loc)));
      end if;

      --  Add formal parameters to match those of the entry and build actuals
      --  for the entry call.

      Add_Matching_Formals (Formals, Actuals);

      Call :=
        Make_Procedure_Call_Statement (Loc,
          Name                   => Call_Nam,
          Parameter_Associations => Actuals);

      --  Add renaming declarations for the discriminants of the enclosing type
      --  as the various contract items may reference them.

      Add_Discriminant_Renamings (Obj_Id, Decls);

      Wrapper_Id :=
        Make_Defining_Identifier (Loc, New_External_Name (Chars (E), 'E'));
      Set_Contract_Wrapper (E, Wrapper_Id);
      Set_Is_Entry_Wrapper (Wrapper_Id);

      --  The wrapper body is analyzed when the enclosing type is frozen

      Append_Freeze_Action (Defining_Entity (Decl),
        Make_Subprogram_Body (Loc,
          Specification              =>
            Make_Procedure_Specification (Loc,
              Defining_Unit_Name       => Wrapper_Id,
              Parameter_Specifications => Formals),
          Declarations               => Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc,
              Statements => New_List (Call))));
   end Build_Contract_Wrapper;

   --------------------------------
   -- Build_Corresponding_Record --
   --------------------------------

   function Build_Corresponding_Record
    (N    : Node_Id;
     Ctyp : Entity_Id;
     Loc  : Source_Ptr) return Node_Id
   is
      Rec_Ent  : constant Entity_Id :=
                   Make_Defining_Identifier
                     (Loc, New_External_Name (Chars (Ctyp), 'V'));
      Disc     : Entity_Id;
      Dlist    : List_Id;
      New_Disc : Entity_Id;
      Cdecls   : List_Id;

   begin
      Set_Corresponding_Record_Type     (Ctyp, Rec_Ent);
      Set_Ekind                         (Rec_Ent, E_Record_Type);
      Set_Has_Delayed_Freeze            (Rec_Ent, Has_Delayed_Freeze (Ctyp));
      Set_Is_Concurrent_Record_Type     (Rec_Ent, True);
      Set_Corresponding_Concurrent_Type (Rec_Ent, Ctyp);
      Set_Stored_Constraint             (Rec_Ent, No_Elist);
      Cdecls := New_List;

      --  Use discriminals to create list of discriminants for record, and
      --  create new discriminals for use in default expressions, etc. It is
      --  worth noting that a task discriminant gives rise to 5 entities;

      --  a) The original discriminant.
      --  b) The discriminal for use in the task.
      --  c) The discriminant of the corresponding record.
      --  d) The discriminal for the init proc of the corresponding record.
      --  e) The local variable that renames the discriminant in the procedure
      --     for the task body.

      --  In fact the discriminals b) are used in the renaming declarations
      --  for e). See details in einfo (Handling of Discriminants).

      if Present (Discriminant_Specifications (N)) then
         Dlist := New_List;
         Disc := First_Discriminant (Ctyp);

         while Present (Disc) loop
            New_Disc := CR_Discriminant (Disc);

            Append_To (Dlist,
              Make_Discriminant_Specification (Loc,
                Defining_Identifier => New_Disc,
                Discriminant_Type =>
                  New_Occurrence_Of (Etype (Disc), Loc),
                Expression =>
                  New_Copy (Discriminant_Default_Value (Disc))));

            Next_Discriminant (Disc);
         end loop;

      else
         Dlist := No_List;
      end if;

      --  Now we can construct the record type declaration. Note that this
      --  record is "limited tagged". It is "limited" to reflect the underlying
      --  limitedness of the task or protected object that it represents, and
      --  ensuring for example that it is properly passed by reference. It is
      --  "tagged" to give support to dispatching calls through interfaces. We
      --  propagate here the list of interfaces covered by the concurrent type
      --  (Ada 2005: AI-345).

      return
        Make_Full_Type_Declaration (Loc,
          Defining_Identifier => Rec_Ent,
          Discriminant_Specifications => Dlist,
          Type_Definition =>
            Make_Record_Definition (Loc,
              Component_List  =>
                Make_Component_List (Loc, Component_Items => Cdecls),
              Tagged_Present  =>
                 Ada_Version >= Ada_2005 and then Is_Tagged_Type (Ctyp),
              Interface_List  => Interface_List (N),
              Limited_Present => True));
   end Build_Corresponding_Record;

   ---------------------------------
   -- Build_Dispatching_Tag_Check --
   ---------------------------------

   function Build_Dispatching_Tag_Check
     (K : Entity_Id;
      N : Node_Id) return Node_Id
   is
      Loc : constant Source_Ptr := Sloc (N);

   begin
      return
         Make_Op_Or (Loc,
           Make_Op_Eq (Loc,
             Left_Opnd  =>
               New_Occurrence_Of (K, Loc),
             Right_Opnd =>
               New_Occurrence_Of (RTE (RE_TK_Limited_Tagged), Loc)),

           Make_Op_Eq (Loc,
             Left_Opnd  =>
               New_Occurrence_Of (K, Loc),
             Right_Opnd =>
               New_Occurrence_Of (RTE (RE_TK_Tagged), Loc)));
   end Build_Dispatching_Tag_Check;

   ----------------------------------
   -- Build_Entry_Count_Expression --
   ----------------------------------

   function Build_Entry_Count_Expression
     (Concurrent_Type : Node_Id;
      Component_List  : List_Id;
      Loc             : Source_Ptr) return Node_Id
   is
      Eindx  : Nat;
      Ent    : Entity_Id;
      Ecount : Node_Id;
      Comp   : Node_Id;
      Lo     : Node_Id;
      Hi     : Node_Id;
      Typ    : Entity_Id;
      Large  : Boolean;

   begin
      --  Count number of non-family entries

      Eindx := 0;
      Ent := First_Entity (Concurrent_Type);
      while Present (Ent) loop
         if Ekind (Ent) = E_Entry then
            Eindx := Eindx + 1;
         end if;

         Next_Entity (Ent);
      end loop;

      Ecount := Make_Integer_Literal (Loc, Eindx);

      --  Loop through entry families building the addition nodes

      Ent := First_Entity (Concurrent_Type);
      Comp := First (Component_List);
      while Present (Ent) loop
         if Ekind (Ent) = E_Entry_Family then
            while Chars (Ent) /= Chars (Defining_Identifier (Comp)) loop
               Next (Comp);
            end loop;

            Typ := Etype (Discrete_Subtype_Definition (Parent (Ent)));
            Hi := Type_High_Bound (Typ);
            Lo := Type_Low_Bound  (Typ);
            Large := Is_Potentially_Large_Family
                       (Base_Type (Typ), Concurrent_Type, Lo, Hi);
            Ecount :=
              Make_Op_Add (Loc,
                Left_Opnd  => Ecount,
                Right_Opnd =>
                  Family_Size (Loc, Hi, Lo, Concurrent_Type, Large));
         end if;

         Next_Entity (Ent);
      end loop;

      return Ecount;
   end Build_Entry_Count_Expression;

   ---------------------------
   -- Build_Parameter_Block --
   ---------------------------

   function Build_Parameter_Block
     (Loc     : Source_Ptr;
      Actuals : List_Id;
      Formals : List_Id;
      Decls   : List_Id) return Entity_Id
   is
      Actual   : Entity_Id;
      Comp_Nam : Node_Id;
      Comps    : List_Id;
      Formal   : Entity_Id;
      Has_Comp : Boolean := False;
      Rec_Nam  : Node_Id;

   begin
      Actual := First (Actuals);
      Comps  := New_List;
      Formal := Defining_Identifier (First (Formals));

      while Present (Actual) loop
         if not Is_Controlling_Actual (Actual) then

            --  Generate:
            --    type Ann is access all <actual-type>

            Comp_Nam := Make_Temporary (Loc, 'A');
            Set_Is_Param_Block_Component_Type (Comp_Nam);

            Append_To (Decls,
              Make_Full_Type_Declaration (Loc,
                Defining_Identifier => Comp_Nam,
                Type_Definition     =>
                  Make_Access_To_Object_Definition (Loc,
                    All_Present        => True,
                    Constant_Present   => Ekind (Formal) = E_In_Parameter,
                    Subtype_Indication =>
                      New_Occurrence_Of (Etype (Actual), Loc))));

            --  Generate:
            --    Param : Ann;

            Append_To (Comps,
              Make_Component_Declaration (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc, Chars (Formal)),
                Component_Definition =>
                  Make_Component_Definition (Loc,
                    Aliased_Present =>
                      False,
                    Subtype_Indication =>
                      New_Occurrence_Of (Comp_Nam, Loc))));

            Has_Comp := True;
         end if;

         Next_Actual (Actual);
         Next_Formal_With_Extras (Formal);
      end loop;

      Rec_Nam := Make_Temporary (Loc, 'P');

      if Has_Comp then

         --  Generate:
         --    type Pnn is record
         --       Param1 : Ann1;
         --       ...
         --       ParamN : AnnN;

         --  where Pnn is a parameter wrapping record, Param1 .. ParamN are
         --  the original parameter names and Ann1 .. AnnN are the access to
         --  actual types.

         Append_To (Decls,
           Make_Full_Type_Declaration (Loc,
             Defining_Identifier =>
               Rec_Nam,
             Type_Definition =>
               Make_Record_Definition (Loc,
                 Component_List =>
                   Make_Component_List (Loc, Comps))));
      else
         --  Generate:
         --    type Pnn is null record;

         Append_To (Decls,
           Make_Full_Type_Declaration (Loc,
             Defining_Identifier =>
               Rec_Nam,
             Type_Definition =>
               Make_Record_Definition (Loc,
                 Null_Present   => True,
                 Component_List => Empty)));
      end if;

      return Rec_Nam;
   end Build_Parameter_Block;

   --------------------------------------
   -- Build_Renamed_Formal_Declaration --
   --------------------------------------

   function Build_Renamed_Formal_Declaration
     (New_F          : Entity_Id;
      Formal         : Entity_Id;
      Comp           : Entity_Id;
      Renamed_Formal : Node_Id) return Node_Id
   is
      Loc  : constant Source_Ptr := Sloc (New_F);
      Decl : Node_Id;

   begin
      --  If the formal is a tagged incomplete type, it is already passed
      --  by reference, so it is sufficient to rename the pointer component
      --  that corresponds to the actual. Otherwise we need to dereference
      --  the pointer component to obtain the actual.

      if Is_Incomplete_Type (Etype (Formal))
        and then Is_Tagged_Type (Etype (Formal))
      then
         Decl :=
           Make_Object_Renaming_Declaration (Loc,
             Defining_Identifier => New_F,
             Subtype_Mark        => New_Occurrence_Of (Etype (Comp), Loc),
             Name                => Renamed_Formal);

      else
         Decl :=
           Make_Object_Renaming_Declaration (Loc,
             Defining_Identifier => New_F,
             Subtype_Mark        => New_Occurrence_Of (Etype (Formal), Loc),
             Name                =>
               Make_Explicit_Dereference (Loc, Renamed_Formal));
      end if;

      return Decl;
   end Build_Renamed_Formal_Declaration;

   --------------------------
   -- Build_Wrapper_Bodies --
   --------------------------

   procedure Build_Wrapper_Bodies
     (Loc : Source_Ptr;
      Typ : Entity_Id;
      N   : Node_Id)
   is
      Rec_Typ : Entity_Id;

      function Build_Wrapper_Body
        (Loc     : Source_Ptr;
         Subp_Id : Entity_Id;
         Obj_Typ : Entity_Id;
         Formals : List_Id) return Node_Id;
      --  Ada 2005 (AI-345): Build the body that wraps a primitive operation
      --  associated with a protected or task type. Subp_Id is the subprogram
      --  name which will be wrapped. Obj_Typ is the type of the new formal
      --  parameter which handles dispatching and object notation. Formals are
      --  the original formals of Subp_Id which will be explicitly replicated.

      ------------------------
      -- Build_Wrapper_Body --
      ------------------------

      function Build_Wrapper_Body
        (Loc     : Source_Ptr;
         Subp_Id : Entity_Id;
         Obj_Typ : Entity_Id;
         Formals : List_Id) return Node_Id
      is
         Body_Spec : Node_Id;

      begin
         Body_Spec := Build_Wrapper_Spec (Subp_Id, Obj_Typ, Formals);

         --  The subprogram is not overriding or is not a primitive declared
         --  between two views.

         if No (Body_Spec) then
            return Empty;
         end if;

         declare
            Actuals    : List_Id := No_List;
            Conv_Id    : Node_Id;
            First_Form : Node_Id;
            Formal     : Node_Id;
            Nam        : Node_Id;

         begin
            --  Map formals to actuals. Use the list built for the wrapper
            --  spec, skipping the object notation parameter.

            First_Form := First (Parameter_Specifications (Body_Spec));

            Formal := First_Form;
            Next (Formal);

            if Present (Formal) then
               Actuals := New_List;
               while Present (Formal) loop
                  Append_To (Actuals,
                    Make_Identifier (Loc,
                      Chars => Chars (Defining_Identifier (Formal))));
                  Next (Formal);
               end loop;
            end if;

            --  Special processing for primitives declared between a private
            --  type and its completion: the wrapper needs a properly typed
            --  parameter if the wrapped operation has a controlling first
            --  parameter. Note that this might not be the case for a function
            --  with a controlling result.

            if Is_Private_Primitive_Subprogram (Subp_Id) then
               if No (Actuals) then
                  Actuals := New_List;
               end if;

               if Is_Controlling_Formal (First_Formal (Subp_Id)) then
                  Prepend_To (Actuals,
                    Unchecked_Convert_To
                      (Corresponding_Concurrent_Type (Obj_Typ),
                       Make_Identifier (Loc, Name_uO)));

               else
                  Prepend_To (Actuals,
                    Make_Identifier (Loc,
                      Chars => Chars (Defining_Identifier (First_Form))));
               end if;

               Nam := New_Occurrence_Of (Subp_Id, Loc);
            else
               --  An access-to-variable object parameter requires an explicit
               --  dereference in the unchecked conversion. This case occurs
               --  when a protected entry wrapper must override an interface
               --  level procedure with interface access as first parameter.

               --     O.all.Subp_Id (Formal_1, ..., Formal_N)

               if Nkind (Parameter_Type (First_Form)) =
                    N_Access_Definition
               then
                  Conv_Id :=
                    Make_Explicit_Dereference (Loc,
                      Prefix => Make_Identifier (Loc, Name_uO));
               else
                  Conv_Id := Make_Identifier (Loc, Name_uO);
               end if;

               Nam :=
                 Make_Selected_Component (Loc,
                   Prefix        =>
                     Unchecked_Convert_To
                       (Corresponding_Concurrent_Type (Obj_Typ), Conv_Id),
                   Selector_Name => New_Occurrence_Of (Subp_Id, Loc));
            end if;

            --  Create the subprogram body. For a function, the call to the
            --  actual subprogram has to be converted to the corresponding
            --  record if it is a controlling result.

            if Ekind (Subp_Id) = E_Function then
               declare
                  Res : Node_Id;

               begin
                  Res :=
                     Make_Function_Call (Loc,
                       Name                   => Nam,
                       Parameter_Associations => Actuals);

                  if Has_Controlling_Result (Subp_Id) then
                     Res :=
                       Unchecked_Convert_To
                         (Corresponding_Record_Type (Etype (Subp_Id)), Res);
                  end if;

                  return
                    Make_Subprogram_Body (Loc,
                      Specification              => Body_Spec,
                      Declarations               => Empty_List,
                      Handled_Statement_Sequence =>
                        Make_Handled_Sequence_Of_Statements (Loc,
                          Statements => New_List (
                            Make_Simple_Return_Statement (Loc, Res))));
               end;

            else
               return
                 Make_Subprogram_Body (Loc,
                   Specification              => Body_Spec,
                   Declarations               => Empty_List,
                   Handled_Statement_Sequence =>
                     Make_Handled_Sequence_Of_Statements (Loc,
                       Statements => New_List (
                         Make_Procedure_Call_Statement (Loc,
                           Name                   => Nam,
                           Parameter_Associations => Actuals))));
            end if;
         end;
      end Build_Wrapper_Body;

   --  Start of processing for Build_Wrapper_Bodies

   begin
      if Is_Concurrent_Type (Typ) then
         Rec_Typ := Corresponding_Record_Type (Typ);
      else
         Rec_Typ := Typ;
      end if;

      --  Generate wrapper bodies for a concurrent type which implements an
      --  interface.

      if Present (Interfaces (Rec_Typ)) then
         declare
            Insert_Nod : Node_Id;
            Prim       : Entity_Id;
            Prim_Elmt  : Elmt_Id;
            Prim_Decl  : Node_Id;
            Subp       : Entity_Id;
            Wrap_Body  : Node_Id;
            Wrap_Id    : Entity_Id;

         begin
            Insert_Nod := N;

            --  Examine all primitive operations of the corresponding record
            --  type, looking for wrapper specs. Generate bodies in order to
            --  complete them.

            Prim_Elmt := First_Elmt (Primitive_Operations (Rec_Typ));
            while Present (Prim_Elmt) loop
               Prim := Node (Prim_Elmt);

               if (Ekind (Prim) = E_Function
                    or else Ekind (Prim) = E_Procedure)
                 and then Is_Primitive_Wrapper (Prim)
               then
                  Subp := Wrapped_Entity (Prim);
                  Prim_Decl := Parent (Parent (Prim));

                  Wrap_Body :=
                    Build_Wrapper_Body (Loc,
                      Subp_Id => Subp,
                      Obj_Typ => Rec_Typ,
                      Formals => Parameter_Specifications (Parent (Subp)));
                  Wrap_Id := Defining_Unit_Name (Specification (Wrap_Body));

                  Set_Corresponding_Spec (Wrap_Body, Prim);
                  Set_Corresponding_Body (Prim_Decl, Wrap_Id);

                  Insert_After (Insert_Nod, Wrap_Body);
                  Insert_Nod := Wrap_Body;

                  Analyze (Wrap_Body);
               end if;

               Next_Elmt (Prim_Elmt);
            end loop;
         end;
      end if;
   end Build_Wrapper_Bodies;

   ------------------------
   -- Build_Wrapper_Spec --
   ------------------------

   function Build_Wrapper_Spec
     (Subp_Id : Entity_Id;
      Obj_Typ : Entity_Id;
      Formals : List_Id) return Node_Id
   is
      function Overriding_Possible
        (Iface_Op : Entity_Id;
         Wrapper  : Entity_Id) return Boolean;
      --  Determine whether a primitive operation can be overridden by Wrapper.
      --  Iface_Op is the candidate primitive operation of an interface type,
      --  Wrapper is the generated entry wrapper.

      function Replicate_Formals
        (Loc     : Source_Ptr;
         Formals : List_Id) return List_Id;
      --  An explicit parameter replication is required due to the Is_Entry_
      --  Formal flag being set for all the formals of an entry. The explicit
      --  replication removes the flag that would otherwise cause a different
      --  path of analysis.

      -------------------------
      -- Overriding_Possible --
      -------------------------

      function Overriding_Possible
        (Iface_Op : Entity_Id;
         Wrapper  : Entity_Id) return Boolean
      is
         Iface_Op_Spec : constant Node_Id := Parent (Iface_Op);
         Wrapper_Spec  : constant Node_Id := Parent (Wrapper);

         function Type_Conformant_Parameters
           (Iface_Op_Params : List_Id;
            Wrapper_Params  : List_Id) return Boolean;
         --  Determine whether the parameters of the generated entry wrapper
         --  and those of a primitive operation are type conformant. During
         --  this check, the first parameter of the primitive operation is
         --  skipped if it is a controlling argument: protected functions
         --  may have a controlling result.

         --------------------------------
         -- Type_Conformant_Parameters --
         --------------------------------

         function Type_Conformant_Parameters
           (Iface_Op_Params : List_Id;
            Wrapper_Params  : List_Id) return Boolean
         is
            Iface_Op_Param : Node_Id;
            Iface_Op_Typ   : Entity_Id;
            Wrapper_Param  : Node_Id;
            Wrapper_Typ    : Entity_Id;

         begin
            --  Skip the first (controlling) parameter of primitive operation

            Iface_Op_Param := First (Iface_Op_Params);

            if Present (First_Formal (Iface_Op))
              and then Is_Controlling_Formal (First_Formal (Iface_Op))
            then
               Iface_Op_Param := Next (Iface_Op_Param);
            end if;

            Wrapper_Param  := First (Wrapper_Params);
            while Present (Iface_Op_Param)
              and then Present (Wrapper_Param)
            loop
               Iface_Op_Typ := Find_Parameter_Type (Iface_Op_Param);
               Wrapper_Typ  := Find_Parameter_Type (Wrapper_Param);

               --  The two parameters must be mode conformant

               if not Conforming_Types
                        (Iface_Op_Typ, Wrapper_Typ, Mode_Conformant)
               then
                  return False;
               end if;

               Next (Iface_Op_Param);
               Next (Wrapper_Param);
            end loop;

            --  One of the lists is longer than the other

            if Present (Iface_Op_Param) or else Present (Wrapper_Param) then
               return False;
            end if;

            return True;
         end Type_Conformant_Parameters;

      --  Start of processing for Overriding_Possible

      begin
         if Chars (Iface_Op) /= Chars (Wrapper) then
            return False;
         end if;

         --  If an inherited subprogram is implemented by a protected procedure
         --  or an entry, then the first parameter of the inherited subprogram
         --  must be of mode OUT or IN OUT, or access-to-variable parameter.

         if Ekind (Iface_Op) = E_Procedure
           and then Present (Parameter_Specifications (Iface_Op_Spec))
         then
            declare
               Obj_Param : constant Node_Id :=
                             First (Parameter_Specifications (Iface_Op_Spec));
            begin
               if not Out_Present (Obj_Param)
                 and then Nkind (Parameter_Type (Obj_Param)) /=
                                                         N_Access_Definition
               then
                  return False;
               end if;
            end;
         end if;

         return
           Type_Conformant_Parameters
             (Parameter_Specifications (Iface_Op_Spec),
              Parameter_Specifications (Wrapper_Spec));
      end Overriding_Possible;

      -----------------------
      -- Replicate_Formals --
      -----------------------

      function Replicate_Formals
        (Loc     : Source_Ptr;
         Formals : List_Id) return List_Id
      is
         New_Formals : constant List_Id := New_List;
         Formal      : Node_Id;
         Param_Type  : Node_Id;

      begin
         Formal := First (Formals);

         --  Skip the object parameter when dealing with primitives declared
         --  between two views.

         if Is_Private_Primitive_Subprogram (Subp_Id)
           and then not Has_Controlling_Result (Subp_Id)
         then
            Formal := Next (Formal);
         end if;

         while Present (Formal) loop

            --  Create an explicit copy of the entry parameter

            --  When creating the wrapper subprogram for a primitive operation
            --  of a protected interface we must construct an equivalent
            --  signature to that of the overriding operation. For regular
            --  parameters we can just use the type of the formal, but for
            --  access to subprogram parameters we need to reanalyze the
            --  parameter type to create local entities for the signature of
            --  the subprogram type. Using the entities of the overriding
            --  subprogram will result in out-of-scope errors in the back-end.

            if Nkind (Parameter_Type (Formal)) = N_Access_Definition then
               Param_Type := Copy_Separate_Tree (Parameter_Type (Formal));
            else
               Param_Type :=
                 New_Occurrence_Of (Etype (Parameter_Type (Formal)), Loc);
            end if;

            Append_To (New_Formals,
              Make_Parameter_Specification (Loc,
                Defining_Identifier    =>
                  Make_Defining_Identifier (Loc,
                    Chars => Chars (Defining_Identifier (Formal))),
                In_Present             => In_Present  (Formal),
                Out_Present            => Out_Present (Formal),
                Null_Exclusion_Present => Null_Exclusion_Present (Formal),
                Parameter_Type         => Param_Type));

            Next (Formal);
         end loop;

         return New_Formals;
      end Replicate_Formals;

      --  Local variables

      Loc             : constant Source_Ptr := Sloc (Subp_Id);
      First_Param     : Node_Id := Empty;
      Iface           : Entity_Id;
      Iface_Elmt      : Elmt_Id;
      Iface_Op        : Entity_Id;
      Iface_Op_Elmt   : Elmt_Id;
      Overridden_Subp : Entity_Id;

   --  Start of processing for Build_Wrapper_Spec

   begin
      --  No point in building wrappers for untagged concurrent types

      pragma Assert (Is_Tagged_Type (Obj_Typ));

      --  Check if this subprogram has a profile that matches some interface
      --  primitive.

      Check_Synchronized_Overriding (Subp_Id, Overridden_Subp);

      if Present (Overridden_Subp) then
         First_Param :=
           First (Parameter_Specifications (Parent (Overridden_Subp)));

      --  An entry or a protected procedure can override a routine where the
      --  controlling formal is either IN OUT, OUT or is of access-to-variable
      --  type. Since the wrapper must have the exact same signature as that of
      --  the overridden subprogram, we try to find the overriding candidate
      --  and use its controlling formal.

      --  Check every implemented interface

      elsif Present (Interfaces (Obj_Typ)) then
         Iface_Elmt := First_Elmt (Interfaces (Obj_Typ));
         Search : while Present (Iface_Elmt) loop
            Iface := Node (Iface_Elmt);

            --  Check every interface primitive

            if Present (Primitive_Operations (Iface)) then
               Iface_Op_Elmt := First_Elmt (Primitive_Operations (Iface));
               while Present (Iface_Op_Elmt) loop
                  Iface_Op := Node (Iface_Op_Elmt);

                  --  Ignore predefined primitives

                  if not Is_Predefined_Dispatching_Operation (Iface_Op) then
                     Iface_Op := Ultimate_Alias (Iface_Op);

                     --  The current primitive operation can be overridden by
                     --  the generated entry wrapper.

                     if Overriding_Possible (Iface_Op, Subp_Id) then
                        First_Param :=
                          First (Parameter_Specifications (Parent (Iface_Op)));

                        exit Search;
                     end if;
                  end if;

                  Next_Elmt (Iface_Op_Elmt);
               end loop;
            end if;

            Next_Elmt (Iface_Elmt);
         end loop Search;
      end if;

      --  Do not generate the wrapper if no interface primitive is covered by
      --  the subprogram and it is not a primitive declared between two views
      --  (see Process_Full_View).

      if No (First_Param)
        and then not Is_Private_Primitive_Subprogram (Subp_Id)
      then
         return Empty;
      end if;

      declare
         Wrapper_Id    : constant Entity_Id :=
                           Make_Defining_Identifier (Loc, Chars (Subp_Id));
         New_Formals   : List_Id;
         Obj_Param     : Node_Id;
         Obj_Param_Typ : Entity_Id;

      begin
         --  Minimum decoration is needed to catch the entity in
         --  Sem_Ch6.Override_Dispatching_Operation.

         if Ekind (Subp_Id) = E_Function then
            Set_Ekind (Wrapper_Id, E_Function);
         else
            Set_Ekind (Wrapper_Id, E_Procedure);
         end if;

         Set_Is_Primitive_Wrapper (Wrapper_Id);
         Set_Wrapped_Entity       (Wrapper_Id, Subp_Id);
         Set_Is_Private_Primitive (Wrapper_Id,
           Is_Private_Primitive_Subprogram (Subp_Id));

         --  Process the formals

         New_Formals := Replicate_Formals (Loc, Formals);

         --  A function with a controlling result and no first controlling
         --  formal needs no additional parameter.

         if Has_Controlling_Result (Subp_Id)
           and then
             (No (First_Formal (Subp_Id))
               or else not Is_Controlling_Formal (First_Formal (Subp_Id)))
         then
            null;

         --  Routine Subp_Id has been found to override an interface primitive.
         --  If the interface operation has an access parameter, create a copy
         --  of it, with the same null exclusion indicator if present.

         elsif Present (First_Param) then
            if Nkind (Parameter_Type (First_Param)) = N_Access_Definition then
               Obj_Param_Typ :=
                 Make_Access_Definition (Loc,
                   Subtype_Mark           =>
                     New_Occurrence_Of (Obj_Typ, Loc),
                   Null_Exclusion_Present =>
                     Null_Exclusion_Present (Parameter_Type (First_Param)),
                   Constant_Present       =>
                     Constant_Present (Parameter_Type (First_Param)));
            else
               Obj_Param_Typ := New_Occurrence_Of (Obj_Typ, Loc);
            end if;

            Obj_Param :=
              Make_Parameter_Specification (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc,
                    Chars => Name_uO),
                In_Present          => In_Present  (First_Param),
                Out_Present         => Out_Present (First_Param),
                Parameter_Type      => Obj_Param_Typ);

            Prepend_To (New_Formals, Obj_Param);

         --  If we are dealing with a primitive declared between two views,
         --  implemented by a synchronized operation, we need to create
         --  a default parameter. The mode of the parameter must match that
         --  of the primitive operation.

         else
            pragma Assert (Is_Private_Primitive_Subprogram (Subp_Id));

            Obj_Param :=
              Make_Parameter_Specification (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc, Name_uO),
                In_Present          =>
                  In_Present (Parent (First_Entity (Subp_Id))),
                Out_Present         => Ekind (Subp_Id) /= E_Function,
                Parameter_Type      => New_Occurrence_Of (Obj_Typ, Loc));

            Prepend_To (New_Formals, Obj_Param);
         end if;

         --  Build the final spec. If it is a function with a controlling
         --  result, it is a primitive operation of the corresponding
         --  record type, so mark the spec accordingly.

         if Ekind (Subp_Id) = E_Function then
            declare
               Res_Def : Node_Id;

            begin
               if Has_Controlling_Result (Subp_Id) then
                  Res_Def :=
                    New_Occurrence_Of
                      (Corresponding_Record_Type (Etype (Subp_Id)), Loc);
               else
                  Res_Def := New_Copy (Result_Definition (Parent (Subp_Id)));
               end if;

               return
                 Make_Function_Specification (Loc,
                   Defining_Unit_Name       => Wrapper_Id,
                   Parameter_Specifications => New_Formals,
                   Result_Definition        => Res_Def);
            end;
         else
            return
              Make_Procedure_Specification (Loc,
                Defining_Unit_Name       => Wrapper_Id,
                Parameter_Specifications => New_Formals);
         end if;
      end;
   end Build_Wrapper_Spec;

   -------------------------
   -- Build_Wrapper_Specs --
   -------------------------

   procedure Build_Wrapper_Specs
     (Loc : Source_Ptr;
      Typ : Entity_Id;
      N   : in out Node_Id)
   is
      Def     : Node_Id;
      Rec_Typ : Entity_Id;
      procedure Scan_Declarations (L : List_Id);
      --  Common processing for visible and private declarations
      --  of a protected type.

      procedure Scan_Declarations (L : List_Id) is
         Decl      : Node_Id;
         Wrap_Decl : Node_Id;
         Wrap_Spec : Node_Id;

      begin
         if No (L) then
            return;
         end if;

         Decl := First (L);
         while Present (Decl) loop
            Wrap_Spec := Empty;

            if Nkind (Decl) = N_Entry_Declaration
              and then Ekind (Defining_Identifier (Decl)) = E_Entry
            then
               Wrap_Spec :=
                 Build_Wrapper_Spec
                   (Subp_Id => Defining_Identifier (Decl),
                    Obj_Typ => Rec_Typ,
                    Formals => Parameter_Specifications (Decl));

            elsif Nkind (Decl) = N_Subprogram_Declaration then
               Wrap_Spec :=
                 Build_Wrapper_Spec
                   (Subp_Id => Defining_Unit_Name (Specification (Decl)),
                    Obj_Typ => Rec_Typ,
                    Formals =>
                      Parameter_Specifications (Specification (Decl)));
            end if;

            if Present (Wrap_Spec) then
               Wrap_Decl :=
                 Make_Subprogram_Declaration (Loc,
                   Specification => Wrap_Spec);

               Insert_After (N, Wrap_Decl);
               N := Wrap_Decl;

               Analyze (Wrap_Decl);
            end if;

            Next (Decl);
         end loop;
      end Scan_Declarations;

      --  start of processing for Build_Wrapper_Specs

   begin
      if Is_Protected_Type (Typ) then
         Def := Protected_Definition (Parent (Typ));
      else pragma Assert (Is_Task_Type (Typ));
         Def := Task_Definition (Parent (Typ));
      end if;

      Rec_Typ := Corresponding_Record_Type (Typ);

      --  Generate wrapper specs for a concurrent type which implements an
      --  interface. Operations in both the visible and private parts may
      --  implement progenitor operations.

      if Present (Interfaces (Rec_Typ)) and then Present (Def) then
         Scan_Declarations (Visible_Declarations (Def));
         Scan_Declarations (Private_Declarations (Def));
      end if;
   end Build_Wrapper_Specs;

   ---------------------------
   -- Build_Find_Body_Index --
   ---------------------------

   function Build_Find_Body_Index (Typ : Entity_Id) return Node_Id is
      Loc   : constant Source_Ptr := Sloc (Typ);
      Ent   : Entity_Id;
      E_Typ : Entity_Id;
      Has_F : Boolean := False;
      Index : Nat;
      If_St : Node_Id := Empty;
      Lo    : Node_Id;
      Hi    : Node_Id;
      Decls : List_Id := New_List;
      Ret   : Node_Id;
      Spec  : Node_Id;
      Siz   : Node_Id := Empty;

      procedure Add_If_Clause (Expr : Node_Id);
      --  Add test for range of current entry

      function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id;
      --  If a bound of an entry is given by a discriminant, retrieve the
      --  actual value of the discriminant from the enclosing object.

      -------------------
      -- Add_If_Clause --
      -------------------

      procedure Add_If_Clause (Expr : Node_Id) is
         Cond  : Node_Id;
         Stats : constant List_Id :=
                   New_List (
                     Make_Simple_Return_Statement (Loc,
                       Expression => Make_Integer_Literal (Loc, Index + 1)));

      begin
         --  Index for current entry body

         Index := Index + 1;

         --  Compute total length of entry queues so far

         if No (Siz) then
            Siz := Expr;
         else
            Siz :=
              Make_Op_Add (Loc,
                Left_Opnd  => Siz,
                Right_Opnd => Expr);
         end if;

         Cond :=
           Make_Op_Le (Loc,
             Left_Opnd  => Make_Identifier (Loc, Name_uE),
             Right_Opnd => Siz);

         --  Map entry queue indexes in the range of the current family
         --  into the current index, that designates the entry body.

         if No (If_St) then
            If_St :=
              Make_Implicit_If_Statement (Typ,
                Condition       => Cond,
                Then_Statements => Stats,
                Elsif_Parts     => New_List);
            Ret := If_St;

         else
            Append_To (Elsif_Parts (If_St),
              Make_Elsif_Part (Loc,
                Condition => Cond,
                Then_Statements => Stats));
         end if;
      end Add_If_Clause;

      ------------------------------
      -- Convert_Discriminant_Ref --
      ------------------------------

      function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is
         B   : Node_Id;

      begin
         if Is_Entity_Name (Bound)
           and then Ekind (Entity (Bound)) = E_Discriminant
         then
            B :=
              Make_Selected_Component (Loc,
               Prefix =>
                 Unchecked_Convert_To (Corresponding_Record_Type (Typ),
                   Make_Explicit_Dereference (Loc,
                     Make_Identifier (Loc, Name_uObject))),
               Selector_Name => Make_Identifier (Loc, Chars (Bound)));
            Set_Etype (B, Etype (Entity (Bound)));
         else
            B := New_Copy_Tree (Bound);
         end if;

         return B;
      end Convert_Discriminant_Ref;

   --  Start of processing for Build_Find_Body_Index

   begin
      Spec := Build_Find_Body_Index_Spec (Typ);

      Ent := First_Entity (Typ);
      while Present (Ent) loop
         if Ekind (Ent) = E_Entry_Family then
            Has_F := True;
            exit;
         end if;

         Next_Entity (Ent);
      end loop;

      if not Has_F then

         --  If the protected type has no entry families, there is a one-one
         --  correspondence between entry queue and entry body.

         Ret :=
           Make_Simple_Return_Statement (Loc,
             Expression => Make_Identifier (Loc, Name_uE));

      else
         --  Suppose entries e1, e2, ... have size l1, l2, ... we generate
         --  the following:

         --  if E <= l1 then return 1;
         --  elsif E <= l1 + l2 then return 2;
         --  ...

         Index := 0;
         Siz   := Empty;
         Ent   := First_Entity (Typ);

         Add_Object_Pointer (Loc, Typ, Decls);

         while Present (Ent) loop
            if Ekind (Ent) = E_Entry then
               Add_If_Clause (Make_Integer_Literal (Loc, 1));

            elsif Ekind (Ent) = E_Entry_Family then
               E_Typ := Etype (Discrete_Subtype_Definition (Parent (Ent)));
               Hi := Convert_Discriminant_Ref (Type_High_Bound (E_Typ));
               Lo := Convert_Discriminant_Ref (Type_Low_Bound  (E_Typ));
               Add_If_Clause (Family_Size (Loc, Hi, Lo, Typ, False));
            end if;

            Next_Entity (Ent);
         end loop;

         if Index = 1 then
            Decls := New_List;
            Ret :=
              Make_Simple_Return_Statement (Loc,
                Expression => Make_Integer_Literal (Loc, 1));

         elsif Nkind (Ret) = N_If_Statement then

            --  Ranges are in increasing order, so last one doesn't need guard

            declare
               Nod : constant Node_Id := Last (Elsif_Parts (Ret));
            begin
               Remove (Nod);
               Set_Else_Statements (Ret, Then_Statements (Nod));
            end;
         end if;
      end if;

      return
        Make_Subprogram_Body (Loc,
          Specification              => Spec,
          Declarations               => Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc,
              Statements => New_List (Ret)));
   end Build_Find_Body_Index;

   --------------------------------
   -- Build_Find_Body_Index_Spec --
   --------------------------------

   function Build_Find_Body_Index_Spec (Typ : Entity_Id) return Node_Id is
      Loc   : constant Source_Ptr := Sloc (Typ);
      Id    : constant Entity_Id :=
               Make_Defining_Identifier (Loc,
                 Chars => New_External_Name (Chars (Typ), 'F'));
      Parm1 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uO);
      Parm2 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uE);

   begin
      return
        Make_Function_Specification (Loc,
          Defining_Unit_Name       => Id,
          Parameter_Specifications => New_List (
            Make_Parameter_Specification (Loc,
              Defining_Identifier => Parm1,
              Parameter_Type      =>
                New_Occurrence_Of (RTE (RE_Address), Loc)),

            Make_Parameter_Specification (Loc,
              Defining_Identifier => Parm2,
              Parameter_Type      =>
                New_Occurrence_Of (RTE (RE_Protected_Entry_Index), Loc))),

          Result_Definition        => New_Occurrence_Of (
            RTE (RE_Protected_Entry_Index), Loc));
   end Build_Find_Body_Index_Spec;

   -----------------------------------------------
   -- Build_Lock_Free_Protected_Subprogram_Body --
   -----------------------------------------------

   function Build_Lock_Free_Protected_Subprogram_Body
     (N           : Node_Id;
      Prot_Typ    : Node_Id;
      Unprot_Spec : Node_Id) return Node_Id
   is
      Actuals   : constant List_Id    := New_List;
      Loc       : constant Source_Ptr := Sloc (N);
      Spec      : constant Node_Id    := Specification (N);
      Unprot_Id : constant Entity_Id  := Defining_Unit_Name (Unprot_Spec);
      Formal    : Node_Id;
      Prot_Spec : Node_Id;
      Stmt      : Node_Id;

   begin
      --  Create the protected version of the body

      Prot_Spec :=
        Build_Protected_Sub_Specification (N, Prot_Typ, Protected_Mode);

      --  Build the actual parameters which appear in the call to the
      --  unprotected version of the body.

      Formal := First (Parameter_Specifications (Prot_Spec));
      while Present (Formal) loop
         Append_To (Actuals,
           Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));

         Next (Formal);
      end loop;

      --  Function case, generate:
      --    return <Unprot_Func_Call>;

      if Nkind (Spec) = N_Function_Specification then
         Stmt :=
           Make_Simple_Return_Statement (Loc,
             Expression =>
               Make_Function_Call (Loc,
                 Name                   =>
                   Make_Identifier (Loc, Chars (Unprot_Id)),
                 Parameter_Associations => Actuals));

      --  Procedure case, call the unprotected version

      else
         Stmt :=
           Make_Procedure_Call_Statement (Loc,
             Name                   =>
               Make_Identifier (Loc, Chars (Unprot_Id)),
             Parameter_Associations => Actuals);
      end if;

      return
        Make_Subprogram_Body (Loc,
          Declarations               => Empty_List,
          Specification              => Prot_Spec,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc,
              Statements => New_List (Stmt)));
   end Build_Lock_Free_Protected_Subprogram_Body;

   -------------------------------------------------
   -- Build_Lock_Free_Unprotected_Subprogram_Body --
   -------------------------------------------------

   --  Procedures which meet the lock-free implementation requirements and
   --  reference a unique scalar component Comp are expanded in the following
   --  manner:

   --    procedure P (...) is
   --       Expected_Comp : constant Comp_Type :=
   --                         Comp_Type
   --                           (System.Atomic_Primitives.Lock_Free_Read_N
   --                              (_Object.Comp'Address));
   --    begin
   --       loop
   --          declare
   --             <original declarations before the object renaming declaration
   --              of Comp>
   --
   --             Desired_Comp : Comp_Type := Expected_Comp;
   --             Comp         : Comp_Type renames Desired_Comp;
   --
   --             <original delarations after the object renaming declaration
   --              of Comp>
   --
   --          begin
   --             <original statements>
   --             exit when System.Atomic_Primitives.Lock_Free_Try_Write_N
   --                         (_Object.Comp'Address,
   --                          Interfaces.Unsigned_N (Expected_Comp),
   --                          Interfaces.Unsigned_N (Desired_Comp));
   --          end;
   --       end loop;
   --    end P;

   --  Each return and raise statement of P is transformed into an atomic
   --  status check:

   --    if System.Atomic_Primitives.Lock_Free_Try_Write_N
   --         (_Object.Comp'Address,
   --          Interfaces.Unsigned_N (Expected_Comp),
   --          Interfaces.Unsigned_N (Desired_Comp));
   --    then
   --       <original statement>
   --    else
   --       goto L0;
   --    end if;

   --  Functions which meet the lock-free implementation requirements and
   --  reference a unique scalar component Comp are expanded in the following
   --  manner:

   --    function F (...) return ... is
   --       <original declarations before the object renaming declaration
   --        of Comp>
   --
   --       Expected_Comp : constant Comp_Type :=
   --                         Comp_Type
   --                           (System.Atomic_Primitives.Lock_Free_Read_N
   --                              (_Object.Comp'Address));
   --       Comp          : Comp_Type renames Expected_Comp;
   --
   --       <original delarations after the object renaming declaration of
   --        Comp>
   --
   --    begin
   --       <original statements>
   --    end F;

   function Build_Lock_Free_Unprotected_Subprogram_Body
     (N        : Node_Id;
      Prot_Typ : Node_Id) return Node_Id
   is
      function Referenced_Component (N : Node_Id) return Entity_Id;
      --  Subprograms which meet the lock-free implementation criteria are
      --  allowed to reference only one unique component. Return the prival
      --  of the said component.

      --------------------------
      -- Referenced_Component --
      --------------------------

      function Referenced_Component (N : Node_Id) return Entity_Id is
         Comp        : Entity_Id;
         Decl        : Node_Id;
         Source_Comp : Entity_Id := Empty;

      begin
         --  Find the unique source component which N references in its
         --  statements.

         for Index in 1 .. Lock_Free_Subprogram_Table.Last loop
            declare
               Element : Lock_Free_Subprogram renames
                         Lock_Free_Subprogram_Table.Table (Index);
            begin
               if Element.Sub_Body = N then
                  Source_Comp := Element.Comp_Id;
                  exit;
               end if;
            end;
         end loop;

         if No (Source_Comp) then
            return Empty;
         end if;

         --  Find the prival which corresponds to the source component within
         --  the declarations of N.

         Decl := First (Declarations (N));
         while Present (Decl) loop

            --  Privals appear as object renamings

            if Nkind (Decl) = N_Object_Renaming_Declaration then
               Comp := Defining_Identifier (Decl);

               if Present (Prival_Link (Comp))
                 and then Prival_Link (Comp) = Source_Comp
               then
                  return Comp;
               end if;
            end if;

            Next (Decl);
         end loop;

         return Empty;
      end Referenced_Component;

      --  Local variables

      Comp          : constant Entity_Id  := Referenced_Component (N);
      Loc           : constant Source_Ptr := Sloc (N);
      Hand_Stmt_Seq : Node_Id             := Handled_Statement_Sequence (N);
      Decls         : List_Id             := Declarations (N);

   --  Start of processing for Build_Lock_Free_Unprotected_Subprogram_Body

   begin
      --  Add renamings for the protection object, discriminals, privals, and
      --  the entry index constant for use by debugger.

      Debug_Private_Data_Declarations (Decls);

      --  Perform the lock-free expansion when the subprogram references a
      --  protected component.

      if Present (Comp) then
         Protected_Component_Ref : declare
            Comp_Decl    : constant Node_Id   := Parent (Comp);
            Comp_Sel_Nam : constant Node_Id   := Name (Comp_Decl);
            Comp_Type    : constant Entity_Id := Etype (Comp);

            Is_Procedure : constant Boolean :=
                             Ekind (Corresponding_Spec (N)) = E_Procedure;
            --  Indicates if N is a protected procedure body

            Block_Decls   : List_Id;
            Try_Write     : Entity_Id;
            Desired_Comp  : Entity_Id;
            Decl          : Node_Id;
            Label         : Node_Id;
            Label_Id      : Entity_Id := Empty;
            Read          : Entity_Id;
            Expected_Comp : Entity_Id;
            Stmt          : Node_Id;
            Stmts         : List_Id :=
                              New_Copy_List (Statements (Hand_Stmt_Seq));
            Typ_Size      : Int;
            Unsigned      : Entity_Id;

            function Process_Node (N : Node_Id) return Traverse_Result;
            --  Transform a single node if it is a return statement, a raise
            --  statement or a reference to Comp.

            procedure Process_Stmts (Stmts : List_Id);
            --  Given a statement sequence Stmts, wrap any return or raise
            --  statements in the following manner:
            --
            --    if System.Atomic_Primitives.Lock_Free_Try_Write_N
            --         (_Object.Comp'Address,
            --          Interfaces.Unsigned_N (Expected_Comp),
            --          Interfaces.Unsigned_N (Desired_Comp))
            --    then
            --       <Stmt>;
            --    else
            --       goto L0;
            --    end if;

            ------------------
            -- Process_Node --
            ------------------

            function Process_Node (N : Node_Id) return Traverse_Result is

               procedure Wrap_Statement (Stmt : Node_Id);
               --  Wrap an arbitrary statement inside an if statement where the
               --  condition does an atomic check on the state of the object.

               --------------------
               -- Wrap_Statement --
               --------------------

               procedure Wrap_Statement (Stmt : Node_Id) is
               begin
                  --  The first time through, create the declaration of a label
                  --  which is used to skip the remainder of source statements
                  --  if the state of the object has changed.

                  if No (Label_Id) then
                     Label_Id :=
                       Make_Identifier (Loc, New_External_Name ('L', 0));
                     Set_Entity (Label_Id,
                       Make_Defining_Identifier (Loc, Chars (Label_Id)));
                  end if;

                  --  Generate:
                  --    if System.Atomic_Primitives.Lock_Free_Try_Write_N
                  --         (_Object.Comp'Address,
                  --          Interfaces.Unsigned_N (Expected_Comp),
                  --          Interfaces.Unsigned_N (Desired_Comp))
                  --    then
                  --       <Stmt>;
                  --    else
                  --       goto L0;
                  --    end if;

                  Rewrite (Stmt,
                    Make_Implicit_If_Statement (N,
                      Condition       =>
                        Make_Function_Call (Loc,
                          Name                   =>
                            New_Occurrence_Of (Try_Write, Loc),
                          Parameter_Associations => New_List (
                            Make_Attribute_Reference (Loc,
                              Prefix         => Relocate_Node (Comp_Sel_Nam),
                              Attribute_Name => Name_Address),

                            Unchecked_Convert_To (Unsigned,
                              New_Occurrence_Of (Expected_Comp, Loc)),

                            Unchecked_Convert_To (Unsigned,
                              New_Occurrence_Of (Desired_Comp, Loc)))),

                      Then_Statements => New_List (Relocate_Node (Stmt)),

                      Else_Statements => New_List (
                        Make_Goto_Statement (Loc,
                          Name =>
                            New_Occurrence_Of (Entity (Label_Id), Loc)))));
               end Wrap_Statement;

            --  Start of processing for Process_Node

            begin
               --  Wrap each return and raise statement that appear inside a
               --  procedure. Skip the last return statement which is added by
               --  default since it is transformed into an exit statement.

               if Is_Procedure
                 and then ((Nkind (N) = N_Simple_Return_Statement
                             and then N /= Last (Stmts))
                            or else Nkind (N) = N_Extended_Return_Statement
                            or else (Nkind_In (N, N_Raise_Constraint_Error,
                                                  N_Raise_Program_Error,
                                                  N_Raise_Statement,
                                                  N_Raise_Storage_Error)
                                      and then Comes_From_Source (N)))
               then
                  Wrap_Statement (N);
                  return Skip;
               end if;

               --  Force reanalysis

               Set_Analyzed (N, False);

               return OK;
            end Process_Node;

            procedure Process_Nodes is new Traverse_Proc (Process_Node);

            -------------------
            -- Process_Stmts --
            -------------------

            procedure Process_Stmts (Stmts : List_Id) is
               Stmt : Node_Id;
            begin
               Stmt := First (Stmts);
               while Present (Stmt) loop
                  Process_Nodes (Stmt);
                  Next (Stmt);
               end loop;
            end Process_Stmts;

         --  Start of processing for Protected_Component_Ref

         begin
            --  Get the type size

            if Known_Static_Esize (Comp_Type) then
               Typ_Size := UI_To_Int (Esize (Comp_Type));

            --  If the Esize (Object_Size) is unknown at compile time, look at
            --  the RM_Size (Value_Size) since it may have been set by an
            --  explicit representation clause.

            elsif Known_Static_RM_Size (Comp_Type) then
               Typ_Size := UI_To_Int (RM_Size (Comp_Type));

            --  Should not happen since this has already been checked in
            --  Allows_Lock_Free_Implementation (see Sem_Ch9).

            else
               raise Program_Error;
            end if;

            --  Retrieve all relevant atomic routines and types

            case Typ_Size is
               when 8 =>
                  Try_Write := RTE (RE_Lock_Free_Try_Write_8);
                  Read      := RTE (RE_Lock_Free_Read_8);
                  Unsigned  := RTE (RE_Uint8);

               when 16 =>
                  Try_Write := RTE (RE_Lock_Free_Try_Write_16);
                  Read      := RTE (RE_Lock_Free_Read_16);
                  Unsigned  := RTE (RE_Uint16);

               when 32 =>
                  Try_Write := RTE (RE_Lock_Free_Try_Write_32);
                  Read      := RTE (RE_Lock_Free_Read_32);
                  Unsigned  := RTE (RE_Uint32);

               when 64 =>
                  Try_Write := RTE (RE_Lock_Free_Try_Write_64);
                  Read      := RTE (RE_Lock_Free_Read_64);
                  Unsigned  := RTE (RE_Uint64);

               when others =>
                  raise Program_Error;
            end case;

            --  Generate:
            --  Expected_Comp : constant Comp_Type :=
            --                    Comp_Type
            --                      (System.Atomic_Primitives.Lock_Free_Read_N
            --                         (_Object.Comp'Address));

            Expected_Comp :=
              Make_Defining_Identifier (Loc,
                New_External_Name (Chars (Comp), Suffix => "_saved"));

            Decl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => Expected_Comp,
                Object_Definition   => New_Occurrence_Of (Comp_Type, Loc),
                Constant_Present    => True,
                Expression          =>
                  Unchecked_Convert_To (Comp_Type,
                    Make_Function_Call (Loc,
                      Name                   => New_Occurrence_Of (Read, Loc),
                      Parameter_Associations => New_List (
                        Make_Attribute_Reference (Loc,
                          Prefix         => Relocate_Node (Comp_Sel_Nam),
                          Attribute_Name => Name_Address)))));

            --  Protected procedures

            if Is_Procedure then
               --  Move the original declarations inside the generated block

               Block_Decls := Decls;

               --  Reset the declarations list of the protected procedure to
               --  contain only Decl.

               Decls := New_List (Decl);

               --  Generate:
               --    Desired_Comp : Comp_Type := Expected_Comp;

               Desired_Comp :=
                 Make_Defining_Identifier (Loc,
                   New_External_Name (Chars (Comp), Suffix => "_current"));

               --  Insert the declarations of Expected_Comp and Desired_Comp in
               --  the block declarations right before the renaming of the
               --  protected component.

               Insert_Before (Comp_Decl,
                 Make_Object_Declaration (Loc,
                   Defining_Identifier => Desired_Comp,
                   Object_Definition   => New_Occurrence_Of (Comp_Type, Loc),
                   Expression          =>
                     New_Occurrence_Of (Expected_Comp, Loc)));

            --  Protected function

            else
               Desired_Comp := Expected_Comp;

               --  Insert the declaration of Expected_Comp in the function
               --  declarations right before the renaming of the protected
               --  component.

               Insert_Before (Comp_Decl, Decl);
            end if;

            --  Rewrite the protected component renaming declaration to be a
            --  renaming of Desired_Comp.

            --  Generate:
            --    Comp : Comp_Type renames Desired_Comp;

            Rewrite (Comp_Decl,
              Make_Object_Renaming_Declaration (Loc,
                Defining_Identifier =>
                  Defining_Identifier (Comp_Decl),
                Subtype_Mark        =>
                  New_Occurrence_Of (Comp_Type, Loc),
                Name                =>
                  New_Occurrence_Of (Desired_Comp, Loc)));

            --  Wrap any return or raise statements in Stmts in same the manner
            --  described in Process_Stmts.

            Process_Stmts (Stmts);

            --  Generate:
            --    exit when System.Atomic_Primitives.Lock_Free_Try_Write_N
            --                (_Object.Comp'Address,
            --                 Interfaces.Unsigned_N (Expected_Comp),
            --                 Interfaces.Unsigned_N (Desired_Comp))

            if Is_Procedure then
               Stmt :=
                 Make_Exit_Statement (Loc,
                   Condition =>
                     Make_Function_Call (Loc,
                       Name                   =>
                         New_Occurrence_Of (Try_Write, Loc),
                       Parameter_Associations => New_List (
                         Make_Attribute_Reference (Loc,
                           Prefix         => Relocate_Node (Comp_Sel_Nam),
                           Attribute_Name => Name_Address),

                         Unchecked_Convert_To (Unsigned,
                           New_Occurrence_Of (Expected_Comp, Loc)),

                         Unchecked_Convert_To (Unsigned,
                           New_Occurrence_Of (Desired_Comp, Loc)))));

               --  Small optimization: transform the default return statement
               --  of a procedure into the atomic exit statement.

               if Nkind (Last (Stmts)) = N_Simple_Return_Statement then
                  Rewrite (Last (Stmts), Stmt);
               else
                  Append_To (Stmts, Stmt);
               end if;
            end if;

            --  Create the declaration of the label used to skip the rest of
            --  the source statements when the object state changes.

            if Present (Label_Id) then
               Label := Make_Label (Loc, Label_Id);
               Append_To (Decls,
                 Make_Implicit_Label_Declaration (Loc,
                   Defining_Identifier => Entity (Label_Id),
                   Label_Construct     => Label));
               Append_To (Stmts, Label);
            end if;

            --  Generate:
            --    loop
            --       declare
            --          <Decls>
            --       begin
            --          <Stmts>
            --       end;
            --    end loop;

            if Is_Procedure then
               Stmts :=
                 New_List (
                   Make_Loop_Statement (Loc,
                     Statements => New_List (
                       Make_Block_Statement (Loc,
                         Declarations               => Block_Decls,
                         Handled_Statement_Sequence =>
                           Make_Handled_Sequence_Of_Statements (Loc,
                             Statements => Stmts))),
                     End_Label  => Empty));
            end if;

            Hand_Stmt_Seq :=
              Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts);
         end Protected_Component_Ref;
      end if;

      --  Make an unprotected version of the subprogram for use within the same
      --  object, with new name and extra parameter representing the object.

      return
        Make_Subprogram_Body (Loc,
          Specification              =>
            Build_Protected_Sub_Specification (N, Prot_Typ, Unprotected_Mode),
          Declarations               => Decls,
          Handled_Statement_Sequence => Hand_Stmt_Seq);
   end Build_Lock_Free_Unprotected_Subprogram_Body;

   -------------------------
   -- Build_Master_Entity --
   -------------------------

   procedure Build_Master_Entity (Obj_Or_Typ : Entity_Id) is
      Loc        : constant Source_Ptr := Sloc (Obj_Or_Typ);
      Context    : Node_Id;
      Context_Id : Entity_Id;
      Decl       : Node_Id;
      Decls      : List_Id;
      Par        : Node_Id;

   begin
      if Is_Itype (Obj_Or_Typ) then
         Par := Associated_Node_For_Itype (Obj_Or_Typ);
      else
         Par := Parent (Obj_Or_Typ);
      end if;

      --  When creating a master for a record component which is either a task
      --  or access-to-task, the enclosing record is the master scope and the
      --  proper insertion point is the component list.

      if Is_Record_Type (Current_Scope) then
         Context    := Par;
         Context_Id := Current_Scope;
         Decls      := List_Containing (Context);

      --  Default case for object declarations and access types. Note that the
      --  context is updated to the nearest enclosing body, block, package, or
      --  return statement.

      else
         Find_Enclosing_Context (Par, Context, Context_Id, Decls);
      end if;

      --  Do not create a master if one already exists or there is no task
      --  hierarchy.

      if Has_Master_Entity (Context_Id)
        or else Restriction_Active (No_Task_Hierarchy)
      then
         return;
      end if;

      --  Create a master, generate:
      --    _Master : constant Master_Id := Current_Master.all;

      Decl :=
        Make_Object_Declaration (Loc,
          Defining_Identifier =>
            Make_Defining_Identifier (Loc, Name_uMaster),
          Constant_Present    => True,
          Object_Definition   => New_Occurrence_Of (RTE (RE_Master_Id), Loc),
          Expression          =>
            Make_Explicit_Dereference (Loc,
              New_Occurrence_Of (RTE (RE_Current_Master), Loc)));

      --  The master is inserted at the start of the declarative list of the
      --  context.

      Prepend_To (Decls, Decl);

      --  In certain cases where transient scopes are involved, the immediate
      --  scope is not always the proper master scope. Ensure that the master
      --  declaration and entity appear in the same context.

      if Context_Id /= Current_Scope then
         Push_Scope (Context_Id);
         Analyze (Decl);
         Pop_Scope;
      else
         Analyze (Decl);
      end if;

      --  Mark the enclosing scope and its associated construct as being task
      --  masters.

      Set_Has_Master_Entity (Context_Id);

      while Present (Context)
        and then Nkind (Context) /= N_Compilation_Unit
      loop
         if Nkind_In (Context, N_Block_Statement,
                               N_Subprogram_Body,
                               N_Task_Body)
         then
            Set_Is_Task_Master (Context);
            exit;

         elsif Nkind (Parent (Context)) = N_Subunit then
            Context := Corresponding_Stub (Parent (Context));
         end if;

         Context := Parent (Context);
      end loop;
   end Build_Master_Entity;

   ---------------------------
   -- Build_Master_Renaming --
   ---------------------------

   procedure Build_Master_Renaming
     (Ptr_Typ : Entity_Id;
      Ins_Nod : Node_Id := Empty)
   is
      Loc         : constant Source_Ptr := Sloc (Ptr_Typ);
      Context     : Node_Id;
      Master_Decl : Node_Id;
      Master_Id   : Entity_Id;

   begin
      --  Nothing to do if there is no task hierarchy

      if Restriction_Active (No_Task_Hierarchy) then
         return;
      end if;

      --  Determine the proper context to insert the master renaming

      if Present (Ins_Nod) then
         Context := Ins_Nod;
      elsif Is_Itype (Ptr_Typ) then
         Context := Associated_Node_For_Itype (Ptr_Typ);
      else
         Context := Parent (Ptr_Typ);
      end if;

      --  Generate:
      --    <Ptr_Typ>M : Master_Id renames _Master;

      Master_Id :=
        Make_Defining_Identifier (Loc,
          New_External_Name (Chars (Ptr_Typ), 'M'));

      Master_Decl :=
        Make_Object_Renaming_Declaration (Loc,
          Defining_Identifier => Master_Id,
          Subtype_Mark        => New_Occurrence_Of (RTE (RE_Master_Id), Loc),
          Name                => Make_Identifier (Loc, Name_uMaster));

      Insert_Action (Context, Master_Decl);

      --  The renamed master now services the access type

      Set_Master_Id (Ptr_Typ, Master_Id);
   end Build_Master_Renaming;

   -----------------------------------------
   -- Build_Private_Protected_Declaration --
   -----------------------------------------

   function Build_Private_Protected_Declaration
     (N : Node_Id) return Entity_Id
   is
      Loc      : constant Source_Ptr := Sloc (N);
      Body_Id  : constant Entity_Id := Defining_Entity (N);
      Decl     : Node_Id;
      Plist    : List_Id;
      Formal   : Entity_Id;
      New_Spec : Node_Id;
      Spec_Id  : Entity_Id;

   begin
      Formal := First_Formal (Body_Id);

      --  The protected operation always has at least one formal, namely the
      --  object itself, but it is only placed in the parameter list if
      --  expansion is enabled.

      if Present (Formal) or else Expander_Active then
         Plist := Copy_Parameter_List (Body_Id);
      else
         Plist := No_List;
      end if;

      if Nkind (Specification (N)) = N_Procedure_Specification then
         New_Spec :=
           Make_Procedure_Specification (Loc,
              Defining_Unit_Name       =>
                Make_Defining_Identifier (Sloc (Body_Id),
                  Chars => Chars (Body_Id)),
              Parameter_Specifications =>
                Plist);
      else
         New_Spec :=
           Make_Function_Specification (Loc,
             Defining_Unit_Name       =>
               Make_Defining_Identifier (Sloc (Body_Id),
                 Chars => Chars (Body_Id)),
             Parameter_Specifications => Plist,
             Result_Definition        =>
               New_Occurrence_Of (Etype (Body_Id), Loc));
      end if;

      Decl := Make_Subprogram_Declaration (Loc, Specification => New_Spec);
      Insert_Before (N, Decl);
      Spec_Id := Defining_Unit_Name (New_Spec);

      --  Indicate that the entity comes from source, to ensure that cross-
      --  reference information is properly generated. The body itself is
      --  rewritten during expansion, and the body entity will not appear in
      --  calls to the operation.

      Set_Comes_From_Source (Spec_Id, True);
      Analyze (Decl);
      Set_Has_Completion (Spec_Id);
      Set_Convention (Spec_Id, Convention_Protected);
      return Spec_Id;
   end Build_Private_Protected_Declaration;

   ---------------------------
   -- Build_Protected_Entry --
   ---------------------------

   function Build_Protected_Entry
     (N   : Node_Id;
      Ent : Entity_Id;
      Pid : Node_Id) return Node_Id
   is
      Bod_Decls : constant List_Id := New_List;
      Decls     : constant List_Id := Declarations (N);
      End_Lab   : constant Node_Id :=
                    End_Label (Handled_Statement_Sequence (N));
      End_Loc   : constant Source_Ptr :=
                    Sloc (Last (Statements (Handled_Statement_Sequence (N))));
      --  Used for the generated call to Complete_Entry_Body

      Loc : constant Source_Ptr := Sloc (N);

      Bod_Id    : Entity_Id;
      Bod_Spec  : Node_Id;
      Bod_Stmts : List_Id;
      Complete  : Node_Id;
      Ohandle   : Node_Id;

      EH_Loc : Source_Ptr;
      --  Used for the exception handler, inserted at end of the body

   begin
      --  Set the source location on the exception handler only when debugging
      --  the expanded code (see Make_Implicit_Exception_Handler).

      if Debug_Generated_Code then
         EH_Loc := End_Loc;

      --  Otherwise the inserted code should not be visible to the debugger

      else
         EH_Loc := No_Location;
      end if;

      Bod_Id :=
        Make_Defining_Identifier (Loc,
          Chars => Chars (Protected_Body_Subprogram (Ent)));
      Bod_Spec := Build_Protected_Entry_Specification (Loc, Bod_Id, Empty);

      --  Add the following declarations:

      --    type poVP is access poV;
      --    _object : poVP := poVP (_O);

      --  where _O is the formal parameter associated with the concurrent
      --  object. These declarations are needed for Complete_Entry_Body.

      Add_Object_Pointer (Loc, Pid, Bod_Decls);

      --  Add renamings for all formals, the Protection object, discriminals,
      --  privals and the entry index constant for use by debugger.

      Add_Formal_Renamings (Bod_Spec, Bod_Decls, Ent, Loc);
      Debug_Private_Data_Declarations (Decls);

      --  Put the declarations and the statements from the entry

      Bod_Stmts :=
        New_List (
          Make_Block_Statement (Loc,
            Declarations               => Decls,
            Handled_Statement_Sequence => Handled_Statement_Sequence (N)));

      case Corresponding_Runtime_Package (Pid) is
         when System_Tasking_Protected_Objects_Entries =>
            Append_To (Bod_Stmts,
              Make_Procedure_Call_Statement (End_Loc,
                Name                   =>
                  New_Occurrence_Of (RTE (RE_Complete_Entry_Body), Loc),
                Parameter_Associations => New_List (
                  Make_Attribute_Reference (End_Loc,
                    Prefix         =>
                      Make_Selected_Component (End_Loc,
                        Prefix        =>
                          Make_Identifier (End_Loc, Name_uObject),
                        Selector_Name =>
                          Make_Identifier (End_Loc, Name_uObject)),
                    Attribute_Name => Name_Unchecked_Access))));

         when System_Tasking_Protected_Objects_Single_Entry =>

            --  Historically, a call to Complete_Single_Entry_Body was
            --  inserted, but it was a null procedure.

            null;

         when others =>
            raise Program_Error;
      end case;

      --  When exceptions can not be propagated, we never need to call
      --  Exception_Complete_Entry_Body.

      if No_Exception_Handlers_Set then
         return
           Make_Subprogram_Body (Loc,
             Specification              => Bod_Spec,
             Declarations               => Bod_Decls,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => Bod_Stmts,
                 End_Label  => End_Lab));

      else
         Ohandle := Make_Others_Choice (Loc);
         Set_All_Others (Ohandle);

         case Corresponding_Runtime_Package (Pid) is
            when System_Tasking_Protected_Objects_Entries =>
               Complete :=
                 New_Occurrence_Of
                   (RTE (RE_Exceptional_Complete_Entry_Body), Loc);

            when System_Tasking_Protected_Objects_Single_Entry =>
               Complete :=
                 New_Occurrence_Of
                   (RTE (RE_Exceptional_Complete_Single_Entry_Body), Loc);

            when others =>
               raise Program_Error;
         end case;

         --  Establish link between subprogram body entity and source entry

         Set_Corresponding_Protected_Entry (Bod_Id, Ent);

         --  Create body of entry procedure. The renaming declarations are
         --  placed ahead of the block that contains the actual entry body.

         return
           Make_Subprogram_Body (Loc,
             Specification              => Bod_Spec,
             Declarations               => Bod_Decls,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements         => Bod_Stmts,
                 End_Label          => End_Lab,
                 Exception_Handlers => New_List (
                   Make_Implicit_Exception_Handler (EH_Loc,
                     Exception_Choices => New_List (Ohandle),

                     Statements        =>  New_List (
                       Make_Procedure_Call_Statement (EH_Loc,
                         Name                   => Complete,
                         Parameter_Associations => New_List (
                           Make_Attribute_Reference (EH_Loc,
                             Prefix         =>
                               Make_Selected_Component (EH_Loc,
                                 Prefix        =>
                                   Make_Identifier (EH_Loc, Name_uObject),
                                 Selector_Name =>
                                   Make_Identifier (EH_Loc, Name_uObject)),
                             Attribute_Name => Name_Unchecked_Access),

                           Make_Function_Call (EH_Loc,
                             Name =>
                               New_Occurrence_Of
                                 (RTE (RE_Get_GNAT_Exception), Loc)))))))));
      end if;
   end Build_Protected_Entry;

   -----------------------------------------
   -- Build_Protected_Entry_Specification --
   -----------------------------------------

   function Build_Protected_Entry_Specification
     (Loc    : Source_Ptr;
      Def_Id : Entity_Id;
      Ent_Id : Entity_Id) return Node_Id
   is
      P : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uP);

   begin
      Set_Debug_Info_Needed (Def_Id);

      if Present (Ent_Id) then
         Append_Elmt (P, Accept_Address (Ent_Id));
      end if;

      return
        Make_Procedure_Specification (Loc,
          Defining_Unit_Name => Def_Id,
          Parameter_Specifications => New_List (
            Make_Parameter_Specification (Loc,
              Defining_Identifier =>
                Make_Defining_Identifier (Loc, Name_uO),
              Parameter_Type =>
                New_Occurrence_Of (RTE (RE_Address), Loc)),

            Make_Parameter_Specification (Loc,
              Defining_Identifier => P,
              Parameter_Type =>
                New_Occurrence_Of (RTE (RE_Address), Loc)),

            Make_Parameter_Specification (Loc,
              Defining_Identifier =>
                Make_Defining_Identifier (Loc, Name_uE),
              Parameter_Type =>
                New_Occurrence_Of (RTE (RE_Protected_Entry_Index), Loc))));
   end Build_Protected_Entry_Specification;

   --------------------------
   -- Build_Protected_Spec --
   --------------------------

   function Build_Protected_Spec
     (N           : Node_Id;
      Obj_Type    : Entity_Id;
      Ident       : Entity_Id;
      Unprotected : Boolean := False) return List_Id
   is
      Loc       : constant Source_Ptr := Sloc (N);
      Decl      : Node_Id;
      Formal    : Entity_Id;
      New_Plist : List_Id;
      New_Param : Node_Id;

   begin
      New_Plist := New_List;

      Formal := First_Formal (Ident);
      while Present (Formal) loop
         New_Param :=
           Make_Parameter_Specification (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Sloc (Formal), Chars (Formal)),
             Aliased_Present     => Aliased_Present (Parent (Formal)),
             In_Present          => In_Present      (Parent (Formal)),
             Out_Present         => Out_Present     (Parent (Formal)),
             Parameter_Type      => New_Occurrence_Of (Etype (Formal), Loc));

         if Unprotected then
            Set_Protected_Formal (Formal, Defining_Identifier (New_Param));
         end if;

         Append (New_Param, New_Plist);
         Next_Formal (Formal);
      end loop;

      --  If the subprogram is a procedure and the context is not an access
      --  to protected subprogram, the parameter is in-out. Otherwise it is
      --  an in parameter.

      Decl :=
        Make_Parameter_Specification (Loc,
          Defining_Identifier =>
            Make_Defining_Identifier (Loc, Name_uObject),
          In_Present => True,
          Out_Present =>
            (Etype (Ident) = Standard_Void_Type
              and then not Is_RTE (Obj_Type, RE_Address)),
          Parameter_Type =>
            New_Occurrence_Of (Obj_Type, Loc));
      Set_Debug_Info_Needed (Defining_Identifier (Decl));
      Prepend_To (New_Plist, Decl);

      return New_Plist;
   end Build_Protected_Spec;

   ---------------------------------------
   -- Build_Protected_Sub_Specification --
   ---------------------------------------

   function Build_Protected_Sub_Specification
     (N        : Node_Id;
      Prot_Typ : Entity_Id;
      Mode     : Subprogram_Protection_Mode) return Node_Id
   is
      Loc       : constant Source_Ptr := Sloc (N);
      Decl      : Node_Id;
      Def_Id    : Entity_Id;
      New_Id    : Entity_Id;
      New_Plist : List_Id;
      New_Spec  : Node_Id;

      Append_Chr : constant array (Subprogram_Protection_Mode) of Character :=
                     (Dispatching_Mode => ' ',
                      Protected_Mode   => 'P',
                      Unprotected_Mode => 'N');

   begin
      if Ekind (Defining_Unit_Name (Specification (N))) = E_Subprogram_Body
      then
         Decl := Unit_Declaration_Node (Corresponding_Spec (N));
      else
         Decl := N;
      end if;

      Def_Id := Defining_Unit_Name (Specification (Decl));

      New_Plist :=
        Build_Protected_Spec
          (Decl, Corresponding_Record_Type (Prot_Typ), Def_Id,
           Mode = Unprotected_Mode);
      New_Id :=
        Make_Defining_Identifier (Loc,
          Chars => Build_Selected_Name (Prot_Typ, Def_Id, Append_Chr (Mode)));

      --  Reference the original nondispatching subprogram since the analysis
      --  of the object.operation notation may need its original name (see
      --  Sem_Ch4.Names_Match).

      if Mode = Dispatching_Mode then
         Set_Ekind (New_Id, Ekind (Def_Id));
         Set_Original_Protected_Subprogram (New_Id, Def_Id);
      end if;

      --  The unprotected operation carries the user code, and debugging
      --  information must be generated for it, even though this spec does
      --  not come from source. It is also convenient to allow gdb to step
      --  into the protected operation, even though it only contains lock/
      --  unlock calls.

      Set_Debug_Info_Needed (New_Id);

      --  If a pragma Eliminate applies to the source entity, the internal
      --  subprograms will be eliminated as well.

      Set_Is_Eliminated (New_Id, Is_Eliminated (Def_Id));

      if Nkind (Specification (Decl)) = N_Procedure_Specification then
         New_Spec :=
           Make_Procedure_Specification (Loc,
             Defining_Unit_Name       => New_Id,
             Parameter_Specifications => New_Plist);

      --  Create a new specification for the anonymous subprogram type

      else
         New_Spec :=
           Make_Function_Specification (Loc,
             Defining_Unit_Name       => New_Id,
             Parameter_Specifications => New_Plist,
             Result_Definition        =>
               Copy_Result_Type (Result_Definition (Specification (Decl))));

         Set_Return_Present (Defining_Unit_Name (New_Spec));
      end if;

      return New_Spec;
   end Build_Protected_Sub_Specification;

   -------------------------------------
   -- Build_Protected_Subprogram_Body --
   -------------------------------------

   function Build_Protected_Subprogram_Body
     (N         : Node_Id;
      Pid       : Node_Id;
      N_Op_Spec : Node_Id) return Node_Id
   is
      Loc          : constant Source_Ptr := Sloc (N);
      Op_Spec      : Node_Id;
      P_Op_Spec    : Node_Id;
      Uactuals     : List_Id;
      Pformal      : Node_Id;
      Unprot_Call  : Node_Id;
      Sub_Body     : Node_Id;
      Lock_Name    : Node_Id;
      Lock_Stmt    : Node_Id;
      R            : Node_Id;
      Return_Stmt  : Node_Id := Empty;    -- init to avoid gcc 3 warning
      Pre_Stmts    : List_Id := No_List;  -- init to avoid gcc 3 warning
      Stmts        : List_Id;
      Object_Parm  : Node_Id;
      Exc_Safe     : Boolean;
      Lock_Kind    : RE_Id;

   begin
      Op_Spec := Specification (N);
      Exc_Safe := Is_Exception_Safe (N);

      P_Op_Spec :=
        Build_Protected_Sub_Specification (N, Pid, Protected_Mode);

      --  Build a list of the formal parameters of the protected version of
      --  the subprogram to use as the actual parameters of the unprotected
      --  version.

      Uactuals := New_List;
      Pformal := First (Parameter_Specifications (P_Op_Spec));
      while Present (Pformal) loop
         Append_To (Uactuals,
           Make_Identifier (Loc, Chars (Defining_Identifier (Pformal))));
         Next (Pformal);
      end loop;

      --  Make a call to the unprotected version of the subprogram built above
      --  for use by the protected version built below.

      if Nkind (Op_Spec) = N_Function_Specification then
         if Exc_Safe then
            R := Make_Temporary (Loc, 'R');

            Unprot_Call :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => R,
                Constant_Present    => True,
                Object_Definition   =>
                  New_Copy (Result_Definition (N_Op_Spec)),
                Expression          =>
                  Make_Function_Call (Loc,
                    Name                   =>
                      Make_Identifier (Loc,
                        Chars => Chars (Defining_Unit_Name (N_Op_Spec))),
                    Parameter_Associations => Uactuals));

            Return_Stmt :=
              Make_Simple_Return_Statement (Loc,
                Expression => New_Occurrence_Of (R, Loc));

         else
            Unprot_Call :=
              Make_Simple_Return_Statement (Loc,
                Expression =>
                  Make_Function_Call (Loc,
                    Name                   =>
                      Make_Identifier (Loc,
                        Chars => Chars (Defining_Unit_Name (N_Op_Spec))),
                    Parameter_Associations => Uactuals));
         end if;

         Lock_Kind := RE_Lock_Read_Only;

      else
         Unprot_Call :=
           Make_Procedure_Call_Statement (Loc,
             Name                   =>
               Make_Identifier (Loc, Chars (Defining_Unit_Name (N_Op_Spec))),
             Parameter_Associations => Uactuals);

         Lock_Kind := RE_Lock;
      end if;

      --  Wrap call in block that will be covered by an at_end handler

      if not Exc_Safe then
         Unprot_Call :=
           Make_Block_Statement (Loc,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => New_List (Unprot_Call)));
      end if;

      --  Make the protected subprogram body. This locks the protected
      --  object and calls the unprotected version of the subprogram.

      case Corresponding_Runtime_Package (Pid) is
         when System_Tasking_Protected_Objects_Entries =>
            Lock_Name := New_Occurrence_Of (RTE (RE_Lock_Entries), Loc);

         when System_Tasking_Protected_Objects_Single_Entry =>
            Lock_Name := New_Occurrence_Of (RTE (RE_Lock_Entry), Loc);

         when System_Tasking_Protected_Objects =>
            Lock_Name := New_Occurrence_Of (RTE (Lock_Kind), Loc);

         when others =>
            raise Program_Error;
      end case;

      Object_Parm :=
        Make_Attribute_Reference (Loc,
           Prefix         =>
             Make_Selected_Component (Loc,
               Prefix        => Make_Identifier (Loc, Name_uObject),
               Selector_Name => Make_Identifier (Loc, Name_uObject)),
           Attribute_Name => Name_Unchecked_Access);

      Lock_Stmt :=
        Make_Procedure_Call_Statement (Loc,
          Name                   => Lock_Name,
          Parameter_Associations => New_List (Object_Parm));

      if Abort_Allowed then
         Stmts := New_List (
           Build_Runtime_Call (Loc, RE_Abort_Defer),
           Lock_Stmt);

      else
         Stmts := New_List (Lock_Stmt);
      end if;

      if not Exc_Safe then
         Append (Unprot_Call, Stmts);
      else
         if Nkind (Op_Spec) = N_Function_Specification then
            Pre_Stmts := Stmts;
            Stmts     := Empty_List;
         else
            Append (Unprot_Call, Stmts);
         end if;

         --  Historical note: Previously, call to the cleanup was inserted
         --  here. This is now done by Build_Protected_Subprogram_Call_Cleanup,
         --  which is also shared by the 'not Exc_Safe' path.

         Build_Protected_Subprogram_Call_Cleanup (Op_Spec, Pid, Loc, Stmts);

         if Nkind (Op_Spec) = N_Function_Specification then
            Append_To (Stmts, Return_Stmt);
            Append_To (Pre_Stmts,
              Make_Block_Statement (Loc,
                Declarations               => New_List (Unprot_Call),
                Handled_Statement_Sequence =>
                  Make_Handled_Sequence_Of_Statements (Loc,
                    Statements => Stmts)));
            Stmts := Pre_Stmts;
         end if;
      end if;

      Sub_Body :=
        Make_Subprogram_Body (Loc,
          Declarations               => Empty_List,
          Specification              => P_Op_Spec,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts));

      --  Mark this subprogram as a protected subprogram body so that the
      --  cleanup will be inserted. This is done only in the 'not Exc_Safe'
      --  path as otherwise the cleanup has already been inserted.

      if not Exc_Safe then
         Set_Is_Protected_Subprogram_Body (Sub_Body);
      end if;

      return Sub_Body;
   end Build_Protected_Subprogram_Body;

   -------------------------------------
   -- Build_Protected_Subprogram_Call --
   -------------------------------------

   procedure Build_Protected_Subprogram_Call
     (N        : Node_Id;
      Name     : Node_Id;
      Rec      : Node_Id;
      External : Boolean := True)
   is
      Loc     : constant Source_Ptr := Sloc (N);
      Sub     : constant Entity_Id  := Entity (Name);
      New_Sub : Node_Id;
      Params  : List_Id;

   begin
      if External then
         New_Sub := New_Occurrence_Of (External_Subprogram (Sub), Loc);
      else
         New_Sub :=
           New_Occurrence_Of (Protected_Body_Subprogram (Sub), Loc);
      end if;

      if Present (Parameter_Associations (N)) then
         Params := New_Copy_List_Tree (Parameter_Associations (N));
      else
         Params := New_List;
      end if;

      --  If the type is an untagged derived type, convert to the root type,
      --  which is the one on which the operations are defined.

      if Nkind (Rec) = N_Unchecked_Type_Conversion
        and then not Is_Tagged_Type (Etype (Rec))
        and then Is_Derived_Type (Etype (Rec))
      then
         Set_Etype (Rec, Root_Type (Etype (Rec)));
         Set_Subtype_Mark (Rec,
           New_Occurrence_Of (Root_Type (Etype (Rec)), Sloc (N)));
      end if;

      Prepend (Rec, Params);

      if Ekind (Sub) = E_Procedure then
         Rewrite (N,
           Make_Procedure_Call_Statement (Loc,
             Name => New_Sub,
             Parameter_Associations => Params));

      else
         pragma Assert (Ekind (Sub) = E_Function);
         Rewrite (N,
           Make_Function_Call (Loc,
             Name                   => New_Sub,
             Parameter_Associations => Params));

         --  Preserve type of call for subsequent processing (required for
         --  call to Wrap_Transient_Expression in the case of a shared passive
         --  protected).

         Set_Etype (N, Etype (New_Sub));
      end if;

      if External
        and then Nkind (Rec) = N_Unchecked_Type_Conversion
        and then Is_Entity_Name (Expression (Rec))
        and then Is_Shared_Passive (Entity (Expression (Rec)))
      then
         Add_Shared_Var_Lock_Procs (N);
      end if;
   end Build_Protected_Subprogram_Call;

   ---------------------------------------------
   -- Build_Protected_Subprogram_Call_Cleanup --
   ---------------------------------------------

   procedure Build_Protected_Subprogram_Call_Cleanup
     (Op_Spec   : Node_Id;
      Conc_Typ  : Node_Id;
      Loc       : Source_Ptr;
      Stmts     : List_Id)
   is
      Nam       : Node_Id;

   begin
      --  If the associated protected object has entries, a protected
      --  procedure has to service entry queues. In this case generate:

      --    Service_Entries (_object._object'Access);

      if Nkind (Op_Spec) = N_Procedure_Specification
        and then Has_Entries (Conc_Typ)
      then
         case Corresponding_Runtime_Package (Conc_Typ) is
            when System_Tasking_Protected_Objects_Entries =>
               Nam := New_Occurrence_Of (RTE (RE_Service_Entries), Loc);

            when System_Tasking_Protected_Objects_Single_Entry =>
               Nam := New_Occurrence_Of (RTE (RE_Service_Entry), Loc);

            when others =>
               raise Program_Error;
         end case;

         Append_To (Stmts,
           Make_Procedure_Call_Statement (Loc,
             Name                   => Nam,
             Parameter_Associations => New_List (
               Make_Attribute_Reference (Loc,
                 Prefix         =>
                   Make_Selected_Component (Loc,
                     Prefix        => Make_Identifier (Loc, Name_uObject),
                     Selector_Name => Make_Identifier (Loc, Name_uObject)),
                 Attribute_Name => Name_Unchecked_Access))));

      else
         --  Generate:
         --    Unlock (_object._object'Access);

         case Corresponding_Runtime_Package (Conc_Typ) is
            when System_Tasking_Protected_Objects_Entries =>
               Nam := New_Occurrence_Of (RTE (RE_Unlock_Entries), Loc);

            when System_Tasking_Protected_Objects_Single_Entry =>
               Nam := New_Occurrence_Of (RTE (RE_Unlock_Entry), Loc);

            when System_Tasking_Protected_Objects =>
               Nam := New_Occurrence_Of (RTE (RE_Unlock), Loc);

            when others =>
               raise Program_Error;
         end case;

         Append_To (Stmts,
           Make_Procedure_Call_Statement (Loc,
             Name                   => Nam,
             Parameter_Associations => New_List (
               Make_Attribute_Reference (Loc,
                 Prefix         =>
                   Make_Selected_Component (Loc,
                     Prefix        => Make_Identifier (Loc, Name_uObject),
                     Selector_Name => Make_Identifier (Loc, Name_uObject)),
                 Attribute_Name => Name_Unchecked_Access))));
      end if;

      --  Generate:
      --    Abort_Undefer;

      if Abort_Allowed then
         Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
      end if;
   end Build_Protected_Subprogram_Call_Cleanup;

   -------------------------
   -- Build_Selected_Name --
   -------------------------

   function Build_Selected_Name
     (Prefix      : Entity_Id;
      Selector    : Entity_Id;
      Append_Char : Character := ' ') return Name_Id
   is
      Select_Buffer : String (1 .. Hostparm.Max_Name_Length);
      Select_Len    : Natural;

   begin
      Get_Name_String (Chars (Selector));
      Select_Len := Name_Len;
      Select_Buffer (1 .. Select_Len) := Name_Buffer (1 .. Name_Len);
      Get_Name_String (Chars (Prefix));

      --  If scope is anonymous type, discard suffix to recover name of
      --  single protected object. Otherwise use protected type name.

      if Name_Buffer (Name_Len) = 'T' then
         Name_Len := Name_Len - 1;
      end if;

      Add_Str_To_Name_Buffer ("__");
      for J in 1 .. Select_Len loop
         Add_Char_To_Name_Buffer (Select_Buffer (J));
      end loop;

      --  Now add the Append_Char if specified. The encoding to follow
      --  depends on the type of entity. If Append_Char is either 'N' or 'P',
      --  then the entity is associated to a protected type subprogram.
      --  Otherwise, it is a protected type entry. For each case, the
      --  encoding to follow for the suffix is documented in exp_dbug.ads.

      --  It would be better to encapsulate this as a routine in Exp_Dbug ???

      if Append_Char /= ' ' then
         if Append_Char = 'P' or Append_Char = 'N' then
            Add_Char_To_Name_Buffer (Append_Char);
            return Name_Find;
         else
            Add_Str_To_Name_Buffer ((1 => '_', 2 => Append_Char));
            return New_External_Name (Name_Find, ' ', -1);
         end if;
      else
         return Name_Find;
      end if;
   end Build_Selected_Name;

   -----------------------------
   -- Build_Simple_Entry_Call --
   -----------------------------

   --  A task entry call is converted to a call to Call_Simple

   --    declare
   --       P : parms := (parm, parm, parm);
   --    begin
   --       Call_Simple (acceptor-task, entry-index, P'Address);
   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --    end;

   --  Here Pnn is an aggregate of the type constructed for the entry to hold
   --  the parameters, and the constructed aggregate value contains either the
   --  parameters or, in the case of non-elementary types, references to these
   --  parameters. Then the address of this aggregate is passed to the runtime
   --  routine, along with the task id value and the task entry index value.
   --  Pnn is only required if parameters are present.

   --  The assignments after the call are present only in the case of in-out
   --  or out parameters for elementary types, and are used to assign back the
   --  resulting values of such parameters.

   --  Note: the reason that we insert a block here is that in the context
   --  of selects, conditional entry calls etc. the entry call statement
   --  appears on its own, not as an element of a list.

   --  A protected entry call is converted to a Protected_Entry_Call:

   --  declare
   --     P   : E1_Params := (param, param, param);
   --     Pnn : Boolean;
   --     Bnn : Communications_Block;

   --  declare
   --     P   : E1_Params := (param, param, param);
   --     Bnn : Communications_Block;

   --  begin
   --     Protected_Entry_Call (
   --       Object => po._object'Access,
   --       E => <entry index>;
   --       Uninterpreted_Data => P'Address;
   --       Mode => Simple_Call;
   --       Block => Bnn);
   --     parm := P.param;
   --     parm := P.param;
   --       ...
   --  end;

   procedure Build_Simple_Entry_Call
     (N       : Node_Id;
      Concval : Node_Id;
      Ename   : Node_Id;
      Index   : Node_Id)
   is
   begin
      Expand_Call (N);

      --  If call has been inlined, nothing left to do

      if Nkind (N) = N_Block_Statement then
         return;
      end if;

      --  Convert entry call to Call_Simple call

      declare
         Loc       : constant Source_Ptr := Sloc (N);
         Parms     : constant List_Id    := Parameter_Associations (N);
         Stats     : constant List_Id    := New_List;
         Actual    : Node_Id;
         Call      : Node_Id;
         Comm_Name : Entity_Id;
         Conctyp   : Node_Id;
         Decls     : List_Id;
         Ent       : Entity_Id;
         Ent_Acc   : Entity_Id;
         Formal    : Node_Id;
         Iface_Tag : Entity_Id;
         Iface_Typ : Entity_Id;
         N_Node    : Node_Id;
         N_Var     : Node_Id;
         P         : Entity_Id;
         Parm1     : Node_Id;
         Parm2     : Node_Id;
         Parm3     : Node_Id;
         Pdecl     : Node_Id;
         Plist     : List_Id;
         X         : Entity_Id;
         Xdecl     : Node_Id;

      begin
         --  Simple entry and entry family cases merge here

         Ent     := Entity (Ename);
         Ent_Acc := Entry_Parameters_Type (Ent);
         Conctyp := Etype (Concval);

         --  If prefix is an access type, dereference to obtain the task type

         if Is_Access_Type (Conctyp) then
            Conctyp := Designated_Type (Conctyp);
         end if;

         --  Special case for protected subprogram calls

         if Is_Protected_Type (Conctyp)
           and then Is_Subprogram (Entity (Ename))
         then
            if not Is_Eliminated (Entity (Ename)) then
               Build_Protected_Subprogram_Call
                 (N, Ename, Convert_Concurrent (Concval, Conctyp));
               Analyze (N);
            end if;

            return;
         end if;

         --  First parameter is the Task_Id value from the task value or the
         --  Object from the protected object value, obtained by selecting
         --  the _Task_Id or _Object from the result of doing an unchecked
         --  conversion to convert the value to the corresponding record type.

         if Nkind (Concval) = N_Function_Call
           and then Is_Task_Type (Conctyp)
           and then Ada_Version >= Ada_2005
         then
            declare
               ExpR : constant Node_Id   := Relocate_Node (Concval);
               Obj  : constant Entity_Id := Make_Temporary (Loc, 'F', ExpR);
               Decl : Node_Id;

            begin
               Decl :=
                 Make_Object_Declaration (Loc,
                   Defining_Identifier => Obj,
                   Object_Definition   => New_Occurrence_Of (Conctyp, Loc),
                   Expression          => ExpR);
               Set_Etype (Obj, Conctyp);
               Decls := New_List (Decl);
               Rewrite (Concval, New_Occurrence_Of (Obj, Loc));
            end;

         else
            Decls := New_List;
         end if;

         Parm1 := Concurrent_Ref (Concval);

         --  Second parameter is the entry index, computed by the routine
         --  provided for this purpose. The value of this expression is
         --  assigned to an intermediate variable to assure that any entry
         --  family index expressions are evaluated before the entry
         --  parameters.

         if not Is_Protected_Type (Conctyp)
           or else
             Corresponding_Runtime_Package (Conctyp) =
               System_Tasking_Protected_Objects_Entries
         then
            X := Make_Defining_Identifier (Loc, Name_uX);

            Xdecl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => X,
                Object_Definition =>
                  New_Occurrence_Of (RTE (RE_Task_Entry_Index), Loc),
                Expression => Actual_Index_Expression (
                  Loc, Entity (Ename), Index, Concval));

            Append_To (Decls, Xdecl);
            Parm2 := New_Occurrence_Of (X, Loc);

         else
            Xdecl := Empty;
            Parm2 := Empty;
         end if;

         --  The third parameter is the packaged parameters. If there are
         --  none, then it is just the null address, since nothing is passed.

         if No (Parms) then
            Parm3 := New_Occurrence_Of (RTE (RE_Null_Address), Loc);
            P := Empty;

         --  Case of parameters present, where third argument is the address
         --  of a packaged record containing the required parameter values.

         else
            --  First build a list of parameter values, which are references to
            --  objects of the parameter types.

            Plist := New_List;

            Actual := First_Actual (N);
            Formal := First_Formal (Ent);
            while Present (Actual) loop

               --  If it is a by-copy type, copy it to a new variable. The
               --  packaged record has a field that points to this variable.

               if Is_By_Copy_Type (Etype (Actual)) then
                  N_Node :=
                    Make_Object_Declaration (Loc,
                      Defining_Identifier => Make_Temporary (Loc, 'J'),
                      Aliased_Present     => True,
                      Object_Definition   =>
                        New_Occurrence_Of (Etype (Formal), Loc));

                  --  Mark the object as not needing initialization since the
                  --  initialization is performed separately, avoiding errors
                  --  on cases such as formals of null-excluding access types.

                  Set_No_Initialization (N_Node);

                  --  We must make a separate assignment statement for the
                  --  case of limited types. We cannot assign it unless the
                  --  Assignment_OK flag is set first. An out formal of an
                  --  access type or whose type has a Default_Value must also
                  --  be initialized from the actual (see RM 6.4.1 (13-13.1)),
                  --  but no constraint, predicate, or null-exclusion check is
                  --  applied before the call.

                  if Ekind (Formal) /= E_Out_Parameter
                    or else Is_Access_Type (Etype (Formal))
                    or else
                      (Is_Scalar_Type (Etype (Formal))
                        and then
                         Present (Default_Aspect_Value (Etype (Formal))))
                  then
                     N_Var :=
                       New_Occurrence_Of (Defining_Identifier (N_Node), Loc);
                     Set_Assignment_OK (N_Var);
                     Append_To (Stats,
                       Make_Assignment_Statement (Loc,
                         Name       => N_Var,
                         Expression => Relocate_Node (Actual)));

                     --  Mark the object as internal, so we don't later reset
                     --  No_Initialization flag in Default_Initialize_Object,
                     --  which would lead to needless default initialization.
                     --  We don't set this outside the if statement, because
                     --  out scalar parameters without Default_Value do require
                     --  default initialization if Initialize_Scalars applies.

                     Set_Is_Internal (Defining_Identifier (N_Node));

                     --  If actual is an out parameter of a null-excluding
                     --  access type, there is access check on entry, so set
                     --  Suppress_Assignment_Checks on the generated statement
                     --  that assigns the actual to the parameter block

                     Set_Suppress_Assignment_Checks (Last (Stats));
                  end if;

                  Append (N_Node, Decls);

                  Append_To (Plist,
                    Make_Attribute_Reference (Loc,
                      Attribute_Name => Name_Unchecked_Access,
                      Prefix         =>
                        New_Occurrence_Of
                          (Defining_Identifier (N_Node), Loc)));

               else
                  --  Interface class-wide formal

                  if Ada_Version >= Ada_2005
                    and then Ekind (Etype (Formal)) = E_Class_Wide_Type
                    and then Is_Interface (Etype (Formal))
                  then
                     Iface_Typ := Etype (Etype (Formal));

                     --  Generate:
                     --    formal_iface_type! (actual.iface_tag)'reference

                     Iface_Tag :=
                       Find_Interface_Tag (Etype (Actual), Iface_Typ);
                     pragma Assert (Present (Iface_Tag));

                     Append_To (Plist,
                       Make_Reference (Loc,
                         Unchecked_Convert_To (Iface_Typ,
                           Make_Selected_Component (Loc,
                             Prefix        =>
                               Relocate_Node (Actual),
                             Selector_Name =>
                               New_Occurrence_Of (Iface_Tag, Loc)))));
                  else
                     --  Generate:
                     --    actual'reference

                     Append_To (Plist,
                       Make_Reference (Loc, Relocate_Node (Actual)));
                  end if;
               end if;

               Next_Actual (Actual);
               Next_Formal_With_Extras (Formal);
            end loop;

            --  Now build the declaration of parameters initialized with the
            --  aggregate containing this constructed parameter list.

            P := Make_Defining_Identifier (Loc, Name_uP);

            Pdecl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => P,
                Object_Definition   =>
                  New_Occurrence_Of (Designated_Type (Ent_Acc), Loc),
                Expression          =>
                  Make_Aggregate (Loc, Expressions => Plist));

            Parm3 :=
              Make_Attribute_Reference (Loc,
                Prefix         => New_Occurrence_Of (P, Loc),
                Attribute_Name => Name_Address);

            Append (Pdecl, Decls);
         end if;

         --  Now we can create the call, case of protected type

         if Is_Protected_Type (Conctyp) then
            case Corresponding_Runtime_Package (Conctyp) is
               when System_Tasking_Protected_Objects_Entries =>

                  --  Change the type of the index declaration

                  Set_Object_Definition (Xdecl,
                    New_Occurrence_Of (RTE (RE_Protected_Entry_Index), Loc));

                  --  Some additional declarations for protected entry calls

                  if No (Decls) then
                     Decls := New_List;
                  end if;

                  --  Bnn : Communications_Block;

                  Comm_Name := Make_Temporary (Loc, 'B');

                  Append_To (Decls,
                    Make_Object_Declaration (Loc,
                      Defining_Identifier => Comm_Name,
                      Object_Definition   =>
                        New_Occurrence_Of
                           (RTE (RE_Communication_Block), Loc)));

                  --  Some additional statements for protected entry calls

                  --     Protected_Entry_Call (
                  --       Object => po._object'Access,
                  --       E => <entry index>;
                  --       Uninterpreted_Data => P'Address;
                  --       Mode => Simple_Call;
                  --       Block => Bnn);

                  Call :=
                    Make_Procedure_Call_Statement (Loc,
                      Name =>
                        New_Occurrence_Of (RTE (RE_Protected_Entry_Call), Loc),

                      Parameter_Associations => New_List (
                        Make_Attribute_Reference (Loc,
                          Attribute_Name => Name_Unchecked_Access,
                          Prefix         => Parm1),
                        Parm2,
                        Parm3,
                        New_Occurrence_Of (RTE (RE_Simple_Call), Loc),
                        New_Occurrence_Of (Comm_Name, Loc)));

               when System_Tasking_Protected_Objects_Single_Entry =>
                  --     Protected_Single_Entry_Call (
                  --       Object => po._object'Access,
                  --       Uninterpreted_Data => P'Address);

                  Call :=
                    Make_Procedure_Call_Statement (Loc,
                      Name                   =>
                        New_Occurrence_Of
                          (RTE (RE_Protected_Single_Entry_Call), Loc),

                      Parameter_Associations => New_List (
                        Make_Attribute_Reference (Loc,
                          Attribute_Name => Name_Unchecked_Access,
                          Prefix         => Parm1),
                        Parm3));

               when others =>
                  raise Program_Error;
            end case;

         --  Case of task type

         else
            Call :=
              Make_Procedure_Call_Statement (Loc,
                Name                   =>
                  New_Occurrence_Of (RTE (RE_Call_Simple), Loc),
                Parameter_Associations => New_List (Parm1, Parm2, Parm3));

         end if;

         Append_To (Stats, Call);

         --  If there are out or in/out parameters by copy add assignment
         --  statements for the result values.

         if Present (Parms) then
            Actual := First_Actual (N);
            Formal := First_Formal (Ent);

            Set_Assignment_OK (Actual);
            while Present (Actual) loop
               if Is_By_Copy_Type (Etype (Actual))
                 and then Ekind (Formal) /= E_In_Parameter
               then
                  N_Node :=
                    Make_Assignment_Statement (Loc,
                      Name       => New_Copy (Actual),
                      Expression =>
                        Make_Explicit_Dereference (Loc,
                          Make_Selected_Component (Loc,
                            Prefix        => New_Occurrence_Of (P, Loc),
                            Selector_Name =>
                              Make_Identifier (Loc, Chars (Formal)))));

                  --  In all cases (including limited private types) we want
                  --  the assignment to be valid.

                  Set_Assignment_OK (Name (N_Node));

                  --  If the call is the triggering alternative in an
                  --  asynchronous select, or the entry_call alternative of a
                  --  conditional entry call, the assignments for in-out
                  --  parameters are incorporated into the statement list that
                  --  follows, so that there are executed only if the entry
                  --  call succeeds.

                  if (Nkind (Parent (N)) = N_Triggering_Alternative
                       and then N = Triggering_Statement (Parent (N)))
                    or else
                     (Nkind (Parent (N)) = N_Entry_Call_Alternative
                       and then N = Entry_Call_Statement (Parent (N)))
                  then
                     if No (Statements (Parent (N))) then
                        Set_Statements (Parent (N), New_List);
                     end if;

                     Prepend (N_Node, Statements (Parent (N)));

                  else
                     Insert_After (Call, N_Node);
                  end if;
               end if;

               Next_Actual (Actual);
               Next_Formal_With_Extras (Formal);
            end loop;
         end if;

         --  Finally, create block and analyze it

         Rewrite (N,
           Make_Block_Statement (Loc,
             Declarations               => Decls,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => Stats)));

         Analyze (N);
      end;
   end Build_Simple_Entry_Call;

   --------------------------------
   -- Build_Task_Activation_Call --
   --------------------------------

   procedure Build_Task_Activation_Call (N : Node_Id) is
      Loc   : constant Source_Ptr := Sloc (N);
      Chain : Entity_Id;
      Call  : Node_Id;
      Name  : Node_Id;
      P     : Node_Id;

   begin
      --  For sequential elaboration policy, all the tasks will be activated at
      --  the end of the elaboration.

      if Partition_Elaboration_Policy = 'S' then
         return;
      end if;

      --  Get the activation chain entity. Except in the case of a package
      --  body, this is in the node that was passed. For a package body, we
      --  have to find the corresponding package declaration node.

      if Nkind (N) = N_Package_Body then
         P := Corresponding_Spec (N);
         loop
            P := Parent (P);
            exit when Nkind (P) = N_Package_Declaration;
         end loop;

         Chain := Activation_Chain_Entity (P);

      else
         Chain := Activation_Chain_Entity (N);
      end if;

      if Present (Chain) then
         if Restricted_Profile then
            Name := New_Occurrence_Of
                      (RTE (RE_Activate_Restricted_Tasks), Loc);
         else
            Name := New_Occurrence_Of
                      (RTE (RE_Activate_Tasks), Loc);
         end if;

         Call :=
           Make_Procedure_Call_Statement (Loc,
             Name                   => Name,
             Parameter_Associations =>
               New_List (Make_Attribute_Reference (Loc,
                 Prefix         => New_Occurrence_Of (Chain, Loc),
                 Attribute_Name => Name_Unchecked_Access)));

         if Nkind (N) = N_Package_Declaration then
            if Present (Corresponding_Body (N)) then
               null;

            elsif Present (Private_Declarations (Specification (N))) then
               Append (Call, Private_Declarations (Specification (N)));

            else
               Append (Call, Visible_Declarations (Specification (N)));
            end if;

         else
            if Present (Handled_Statement_Sequence (N)) then

               --  The call goes at the start of the statement sequence after
               --  the start of exception range label if one is present.

               declare
                  Stm : Node_Id;

               begin
                  Stm := First (Statements (Handled_Statement_Sequence (N)));

                  --  A special case, skip exception range label if one is
                  --  present (from front end zcx processing).

                  if Nkind (Stm) = N_Label and then Exception_Junk (Stm) then
                     Next (Stm);
                  end if;

                  --  Another special case, if the first statement is a block
                  --  from optimization of a local raise to a goto, then the
                  --  call goes inside this block.

                  if Nkind (Stm) = N_Block_Statement
                    and then Exception_Junk (Stm)
                  then
                     Stm :=
                       First (Statements (Handled_Statement_Sequence (Stm)));
                  end if;

                  --  Insertion point is after any exception label pushes,
                  --  since we want it covered by any local handlers.

                  while Nkind (Stm) in N_Push_xxx_Label loop
                     Next (Stm);
                  end loop;

                  --  Now we have the proper insertion point

                  Insert_Before (Stm, Call);
               end;

            else
               Set_Handled_Statement_Sequence (N,
                  Make_Handled_Sequence_Of_Statements (Loc,
                    Statements => New_List (Call)));
            end if;
         end if;

         Analyze (Call);
         Check_Task_Activation (N);
      end if;
   end Build_Task_Activation_Call;

   -------------------------------
   -- Build_Task_Allocate_Block --
   -------------------------------

   procedure Build_Task_Allocate_Block
     (Actions : List_Id;
      N       : Node_Id;
      Args    : List_Id)
   is
      T      : constant Entity_Id  := Entity (Expression (N));
      Init   : constant Entity_Id  := Base_Init_Proc (T);
      Loc    : constant Source_Ptr := Sloc (N);
      Chain  : constant Entity_Id  :=
                 Make_Defining_Identifier (Loc, Name_uChain);
      Blkent : constant Entity_Id  := Make_Temporary (Loc, 'A');
      Block  : Node_Id;

   begin
      Block :=
        Make_Block_Statement (Loc,
          Identifier   => New_Occurrence_Of (Blkent, Loc),
          Declarations => New_List (

            --  _Chain  : Activation_Chain;

            Make_Object_Declaration (Loc,
              Defining_Identifier => Chain,
              Aliased_Present     => True,
              Object_Definition   =>
                New_Occurrence_Of (RTE (RE_Activation_Chain), Loc))),

          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc,

              Statements => New_List (

                --  Init (Args);

                Make_Procedure_Call_Statement (Loc,
                  Name                   => New_Occurrence_Of (Init, Loc),
                  Parameter_Associations => Args),

                --  Activate_Tasks (_Chain);

                Make_Procedure_Call_Statement (Loc,
                  Name => New_Occurrence_Of (RTE (RE_Activate_Tasks), Loc),
                  Parameter_Associations => New_List (
                    Make_Attribute_Reference (Loc,
                      Prefix         => New_Occurrence_Of (Chain, Loc),
                      Attribute_Name => Name_Unchecked_Access))))),

          Has_Created_Identifier => True,
          Is_Task_Allocation_Block => True);

      Append_To (Actions,
        Make_Implicit_Label_Declaration (Loc,
          Defining_Identifier => Blkent,
          Label_Construct     => Block));

      Append_To (Actions, Block);

      Set_Activation_Chain_Entity (Block, Chain);
   end Build_Task_Allocate_Block;

   -----------------------------------------------
   -- Build_Task_Allocate_Block_With_Init_Stmts --
   -----------------------------------------------

   procedure Build_Task_Allocate_Block_With_Init_Stmts
     (Actions    : List_Id;
      N          : Node_Id;
      Init_Stmts : List_Id)
   is
      Loc    : constant Source_Ptr := Sloc (N);
      Chain  : constant Entity_Id  :=
                 Make_Defining_Identifier (Loc, Name_uChain);
      Blkent : constant Entity_Id  := Make_Temporary (Loc, 'A');
      Block  : Node_Id;

   begin
      Append_To (Init_Stmts,
        Make_Procedure_Call_Statement (Loc,
          Name => New_Occurrence_Of (RTE (RE_Activate_Tasks), Loc),
          Parameter_Associations => New_List (
            Make_Attribute_Reference (Loc,
              Prefix         => New_Occurrence_Of (Chain, Loc),
              Attribute_Name => Name_Unchecked_Access))));

      Block :=
        Make_Block_Statement (Loc,
          Identifier => New_Occurrence_Of (Blkent, Loc),
          Declarations => New_List (

            --  _Chain  : Activation_Chain;

            Make_Object_Declaration (Loc,
              Defining_Identifier => Chain,
              Aliased_Present     => True,
              Object_Definition   =>
                New_Occurrence_Of (RTE (RE_Activation_Chain), Loc))),

          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc, Init_Stmts),

          Has_Created_Identifier => True,
          Is_Task_Allocation_Block => True);

      Append_To (Actions,
        Make_Implicit_Label_Declaration (Loc,
          Defining_Identifier => Blkent,
          Label_Construct     => Block));

      Append_To (Actions, Block);

      Set_Activation_Chain_Entity (Block, Chain);
   end Build_Task_Allocate_Block_With_Init_Stmts;

   -----------------------------------
   -- Build_Task_Proc_Specification --
   -----------------------------------

   function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id is
      Loc     : constant Source_Ptr := Sloc (T);
      Spec_Id : Entity_Id;

   begin
      --  Case of explicit task type, suffix TB

      if Comes_From_Source (T) then
         Spec_Id :=
           Make_Defining_Identifier (Loc, New_External_Name (Chars (T), "TB"));

      --  Case of anonymous task type, suffix B

      else
         Spec_Id :=
           Make_Defining_Identifier (Loc, New_External_Name (Chars (T), 'B'));
      end if;

      Set_Is_Internal (Spec_Id);

      --  Associate the procedure with the task, if this is the declaration
      --  (and not the body) of the procedure.

      if No (Task_Body_Procedure (T)) then
         Set_Task_Body_Procedure (T, Spec_Id);
      end if;

      return
        Make_Procedure_Specification (Loc,
          Defining_Unit_Name       => Spec_Id,
          Parameter_Specifications => New_List (
            Make_Parameter_Specification (Loc,
              Defining_Identifier =>
                Make_Defining_Identifier (Loc, Name_uTask),
              Parameter_Type      =>
                Make_Access_Definition (Loc,
                  Subtype_Mark =>
                    New_Occurrence_Of (Corresponding_Record_Type (T), Loc)))));
   end Build_Task_Proc_Specification;

   ---------------------------------------
   -- Build_Unprotected_Subprogram_Body --
   ---------------------------------------

   function Build_Unprotected_Subprogram_Body
     (N   : Node_Id;
      Pid : Node_Id) return Node_Id
   is
      Decls : constant List_Id := Declarations (N);

   begin
      --  Add renamings for the Protection object, discriminals, privals, and
      --  the entry index constant for use by debugger.

      Debug_Private_Data_Declarations (Decls);

      --  Make an unprotected version of the subprogram for use within the same
      --  object, with a new name and an additional parameter representing the
      --  object.

      return
        Make_Subprogram_Body (Sloc (N),
          Specification              =>
            Build_Protected_Sub_Specification (N, Pid, Unprotected_Mode),
          Declarations               => Decls,
          Handled_Statement_Sequence => Handled_Statement_Sequence (N));
   end Build_Unprotected_Subprogram_Body;

   ----------------------------
   -- Collect_Entry_Families --
   ----------------------------

   procedure Collect_Entry_Families
     (Loc          : Source_Ptr;
      Cdecls       : List_Id;
      Current_Node : in out Node_Id;
      Conctyp      : Entity_Id)
   is
      Efam      : Entity_Id;
      Efam_Decl : Node_Id;
      Efam_Type : Entity_Id;

   begin
      Efam := First_Entity (Conctyp);
      while Present (Efam) loop
         if Ekind (Efam) = E_Entry_Family then
            Efam_Type := Make_Temporary (Loc, 'F');

            declare
               Bas : Entity_Id :=
                       Base_Type
                         (Etype (Discrete_Subtype_Definition (Parent (Efam))));

               Bas_Decl : Node_Id := Empty;
               Lo, Hi   : Node_Id;

            begin
               Get_Index_Bounds
                 (Discrete_Subtype_Definition (Parent (Efam)), Lo, Hi);

               if Is_Potentially_Large_Family (Bas, Conctyp, Lo, Hi) then
                  Bas := Make_Temporary (Loc, 'B');

                  Bas_Decl :=
                    Make_Subtype_Declaration (Loc,
                       Defining_Identifier => Bas,
                       Subtype_Indication  =>
                         Make_Subtype_Indication (Loc,
                           Subtype_Mark =>
                             New_Occurrence_Of (Standard_Integer, Loc),
                           Constraint   =>
                             Make_Range_Constraint (Loc,
                               Range_Expression => Make_Range (Loc,
                                 Make_Integer_Literal
                                   (Loc, -Entry_Family_Bound),
                                 Make_Integer_Literal
                                   (Loc, Entry_Family_Bound - 1)))));

                  Insert_After (Current_Node, Bas_Decl);
                  Current_Node := Bas_Decl;
                  Analyze (Bas_Decl);
               end if;

               Efam_Decl :=
                 Make_Full_Type_Declaration (Loc,
                   Defining_Identifier => Efam_Type,
                   Type_Definition =>
                     Make_Unconstrained_Array_Definition (Loc,
                       Subtype_Marks =>
                         (New_List (New_Occurrence_Of (Bas, Loc))),

                    Component_Definition =>
                      Make_Component_Definition (Loc,
                        Aliased_Present    => False,
                        Subtype_Indication =>
                          New_Occurrence_Of (Standard_Character, Loc))));
            end;

            Insert_After (Current_Node, Efam_Decl);
            Current_Node := Efam_Decl;
            Analyze (Efam_Decl);

            Append_To (Cdecls,
              Make_Component_Declaration (Loc,
                Defining_Identifier  =>
                  Make_Defining_Identifier (Loc, Chars (Efam)),

                Component_Definition =>
                  Make_Component_Definition (Loc,
                    Aliased_Present    => False,
                    Subtype_Indication =>
                      Make_Subtype_Indication (Loc,
                        Subtype_Mark =>
                          New_Occurrence_Of (Efam_Type, Loc),

                        Constraint   =>
                          Make_Index_Or_Discriminant_Constraint (Loc,
                            Constraints => New_List (
                              New_Occurrence_Of
                                (Etype (Discrete_Subtype_Definition
                                          (Parent (Efam))), Loc)))))));

         end if;

         Next_Entity (Efam);
      end loop;
   end Collect_Entry_Families;

   -----------------------
   -- Concurrent_Object --
   -----------------------

   function Concurrent_Object
     (Spec_Id  : Entity_Id;
      Conc_Typ : Entity_Id) return Entity_Id
   is
   begin
      --  Parameter _O or _object

      if Is_Protected_Type (Conc_Typ) then
         return First_Formal (Protected_Body_Subprogram (Spec_Id));

      --  Parameter _task

      else
         pragma Assert (Is_Task_Type (Conc_Typ));
         return First_Formal (Task_Body_Procedure (Conc_Typ));
      end if;
   end Concurrent_Object;

   ----------------------
   -- Copy_Result_Type --
   ----------------------

   function Copy_Result_Type (Res : Node_Id) return Node_Id is
      New_Res  : constant Node_Id := New_Copy_Tree (Res);
      Par_Spec : Node_Id;
      Formal   : Entity_Id;

   begin
      --  If the result type is an access_to_subprogram, we must create new
      --  entities for its spec.

      if Nkind (New_Res) = N_Access_Definition
        and then Present (Access_To_Subprogram_Definition (New_Res))
      then
         --  Provide new entities for the formals

         Par_Spec := First (Parameter_Specifications
                              (Access_To_Subprogram_Definition (New_Res)));
         while Present (Par_Spec) loop
            Formal := Defining_Identifier (Par_Spec);
            Set_Defining_Identifier (Par_Spec,
              Make_Defining_Identifier (Sloc (Formal), Chars (Formal)));
            Next (Par_Spec);
         end loop;
      end if;

      return New_Res;
   end Copy_Result_Type;

   --------------------
   -- Concurrent_Ref --
   --------------------

   --  The expression returned for a reference to a concurrent object has the
   --  form:

   --    taskV!(name)._Task_Id

   --  for a task, and

   --    objectV!(name)._Object

   --  for a protected object. For the case of an access to a concurrent
   --  object, there is an extra explicit dereference:

   --    taskV!(name.all)._Task_Id
   --    objectV!(name.all)._Object

   --  here taskV and objectV are the types for the associated records, which
   --  contain the required _Task_Id and _Object fields for tasks and protected
   --  objects, respectively.

   --  For the case of a task type name, the expression is

   --    Self;

   --  i.e. a call to the Self function which returns precisely this Task_Id

   --  For the case of a protected type name, the expression is

   --    objectR

   --  which is a renaming of the _object field of the current object
   --  record, passed into protected operations as a parameter.

   function Concurrent_Ref (N : Node_Id) return Node_Id is
      Loc  : constant Source_Ptr := Sloc (N);
      Ntyp : constant Entity_Id  := Etype (N);
      Dtyp : Entity_Id;
      Sel  : Name_Id;

      function Is_Current_Task (T : Entity_Id) return Boolean;
      --  Check whether the reference is to the immediately enclosing task
      --  type, or to an outer one (rare but legal).

      ---------------------
      -- Is_Current_Task --
      ---------------------

      function Is_Current_Task (T : Entity_Id) return Boolean is
         Scop : Entity_Id;

      begin
         Scop := Current_Scope;
         while Present (Scop) and then Scop /= Standard_Standard loop
            if Scop = T then
               return True;

            elsif Is_Task_Type (Scop) then
               return False;

            --  If this is a procedure nested within the task type, we must
            --  assume that it can be called from an inner task, and therefore
            --  cannot treat it as a local reference.

            elsif Is_Overloadable (Scop) and then In_Open_Scopes (T) then
               return False;

            else
               Scop := Scope (Scop);
            end if;
         end loop;

         --  We know that we are within the task body, so should have found it
         --  in scope.

         raise Program_Error;
      end Is_Current_Task;

   --  Start of processing for Concurrent_Ref

   begin
      if Is_Access_Type (Ntyp) then
         Dtyp := Designated_Type (Ntyp);

         if Is_Protected_Type (Dtyp) then
            Sel := Name_uObject;
         else
            Sel := Name_uTask_Id;
         end if;

         return
           Make_Selected_Component (Loc,
             Prefix        =>
               Unchecked_Convert_To (Corresponding_Record_Type (Dtyp),
                 Make_Explicit_Dereference (Loc, N)),
             Selector_Name => Make_Identifier (Loc, Sel));

      elsif Is_Entity_Name (N) and then Is_Concurrent_Type (Entity (N)) then
         if Is_Task_Type (Entity (N)) then

            if Is_Current_Task (Entity (N)) then
               return
                 Make_Function_Call (Loc,
                   Name => New_Occurrence_Of (RTE (RE_Self), Loc));

            else
               declare
                  Decl   : Node_Id;
                  T_Self : constant Entity_Id := Make_Temporary (Loc, 'T');
                  T_Body : constant Node_Id :=
                             Parent (Corresponding_Body (Parent (Entity (N))));

               begin
                  Decl :=
                    Make_Object_Declaration (Loc,
                      Defining_Identifier => T_Self,
                      Object_Definition   =>
                        New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
                      Expression          =>
                        Make_Function_Call (Loc,
                          Name => New_Occurrence_Of (RTE (RE_Self), Loc)));
                  Prepend (Decl, Declarations (T_Body));
                  Analyze (Decl);
                  Set_Scope (T_Self, Entity (N));
                  return New_Occurrence_Of (T_Self,  Loc);
               end;
            end if;

         else
            pragma Assert (Is_Protected_Type (Entity (N)));

            return
              New_Occurrence_Of (Find_Protection_Object (Current_Scope), Loc);
         end if;

      else
         if Is_Protected_Type (Ntyp) then
            Sel := Name_uObject;
         elsif Is_Task_Type (Ntyp) then
            Sel := Name_uTask_Id;
         else
            raise Program_Error;
         end if;

         return
           Make_Selected_Component (Loc,
             Prefix        =>
               Unchecked_Convert_To (Corresponding_Record_Type (Ntyp),
                 New_Copy_Tree (N)),
             Selector_Name => Make_Identifier (Loc, Sel));
      end if;
   end Concurrent_Ref;

   ------------------------
   -- Convert_Concurrent --
   ------------------------

   function Convert_Concurrent
     (N   : Node_Id;
      Typ : Entity_Id) return Node_Id
   is
   begin
      if not Is_Concurrent_Type (Typ) then
         return N;
      else
         return
           Unchecked_Convert_To
             (Corresponding_Record_Type (Typ), New_Copy_Tree (N));
      end if;
   end Convert_Concurrent;

   -------------------------------------
   -- Debug_Private_Data_Declarations --
   -------------------------------------

   procedure Debug_Private_Data_Declarations (Decls : List_Id) is
      Debug_Nod : Node_Id;
      Decl      : Node_Id;

   begin
      Decl := First (Decls);
      while Present (Decl) and then not Comes_From_Source (Decl) loop

         --  Declaration for concurrent entity _object and its access type,
         --  along with the entry index subtype:
         --    type prot_typVP is access prot_typV;
         --    _object : prot_typVP := prot_typV (_O);
         --    subtype Jnn is <Type of Index> range Low .. High;

         if Nkind_In (Decl, N_Full_Type_Declaration, N_Object_Declaration) then
            Set_Debug_Info_Needed (Defining_Identifier (Decl));

         --  Declaration for the Protection object, discriminals, privals, and
         --  entry index constant:
         --    conc_typR   : protection_typ renames _object._object;
         --    discr_nameD : discr_typ renames _object.discr_name;
         --    discr_nameD : discr_typ renames _task.discr_name;
         --    prival_name : comp_typ  renames _object.comp_name;
         --    J : constant Jnn :=
         --          Jnn'Val (_E - <Index expression> + Jnn'Pos (Jnn'First));

         elsif Nkind (Decl) = N_Object_Renaming_Declaration then
            Set_Debug_Info_Needed (Defining_Identifier (Decl));
            Debug_Nod := Debug_Renaming_Declaration (Decl);

            if Present (Debug_Nod) then
               Insert_After (Decl, Debug_Nod);
            end if;
         end if;

         Next (Decl);
      end loop;
   end Debug_Private_Data_Declarations;

   ------------------------------
   -- Ensure_Statement_Present --
   ------------------------------

   procedure Ensure_Statement_Present (Loc : Source_Ptr; Alt : Node_Id) is
      Stmt : Node_Id;

   begin
      if Opt.Suppress_Control_Flow_Optimizations
        and then Is_Empty_List (Statements (Alt))
      then
         Stmt := Make_Null_Statement (Loc);

         --  Mark NULL statement as coming from source so that it is not
         --  eliminated by GIGI.

         --  Another covert channel. If this is a requirement, it must be
         --  documented in sinfo/einfo ???

         Set_Comes_From_Source (Stmt, True);

         Set_Statements (Alt, New_List (Stmt));
      end if;
   end Ensure_Statement_Present;

   ----------------------------
   -- Entry_Index_Expression --
   ----------------------------

   function Entry_Index_Expression
     (Sloc  : Source_Ptr;
      Ent   : Entity_Id;
      Index : Node_Id;
      Ttyp  : Entity_Id) return Node_Id
   is
      Expr : Node_Id;
      Num  : Node_Id;
      Lo   : Node_Id;
      Hi   : Node_Id;
      Prev : Entity_Id;
      S    : Node_Id;

   begin
      --  The queues of entries and entry families appear in textual order in
      --  the associated record. The entry index is computed as the sum of the
      --  number of queues for all entries that precede the designated one, to
      --  which is added the index expression, if this expression denotes a
      --  member of a family.

      --  The following is a place holder for the count of simple entries

      Num := Make_Integer_Literal (Sloc, 1);

      --  We construct an expression which is a series of addition operations.
      --  The first operand is the number of single entries that precede this
      --  one, the second operand is the index value relative to the start of
      --  the referenced family, and the remaining operands are the lengths of
      --  the entry families that precede this entry, i.e. the constructed
      --  expression is:

      --    number_simple_entries +
      --      (s'pos (index-value) - s'pos (family'first)) + 1 +
      --      family'length + ...

      --  where index-value is the given index value, and s is the index
      --  subtype (we have to use pos because the subtype might be an
      --  enumeration type preventing direct subtraction). Note that the task
      --  entry array is one-indexed.

      --  The upper bound of the entry family may be a discriminant, so we
      --  retrieve the lower bound explicitly to compute offset, rather than
      --  using the index subtype which may mention a discriminant.

      if Present (Index) then
         S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent)));

         Expr :=
           Make_Op_Add (Sloc,
             Left_Opnd  => Num,
             Right_Opnd =>
               Family_Offset
                 (Sloc,
                  Make_Attribute_Reference (Sloc,
                    Attribute_Name => Name_Pos,
                    Prefix         => New_Occurrence_Of (Base_Type (S), Sloc),
                    Expressions    => New_List (Relocate_Node (Index))),
                  Type_Low_Bound (S),
                  Ttyp,
                  False));
      else
         Expr := Num;
      end if;

      --  Now add lengths of preceding entries and entry families

      Prev := First_Entity (Ttyp);
      while Chars (Prev) /= Chars (Ent)
        or else (Ekind (Prev) /= Ekind (Ent))
        or else not Sem_Ch6.Type_Conformant (Ent, Prev)
      loop
         if Ekind (Prev) = E_Entry then
            Set_Intval (Num, Intval (Num) + 1);

         elsif Ekind (Prev) = E_Entry_Family then
            S := Etype (Discrete_Subtype_Definition (Declaration_Node (Prev)));
            Lo := Type_Low_Bound  (S);
            Hi := Type_High_Bound (S);

            Expr :=
              Make_Op_Add (Sloc,
                Left_Opnd  => Expr,
                Right_Opnd => Family_Size (Sloc, Hi, Lo, Ttyp, False));

         --  Other components are anonymous types to be ignored

         else
            null;
         end if;

         Next_Entity (Prev);
      end loop;

      return Expr;
   end Entry_Index_Expression;

   ---------------------------
   -- Establish_Task_Master --
   ---------------------------

   procedure Establish_Task_Master (N : Node_Id) is
      Call : Node_Id;

   begin
      if Restriction_Active (No_Task_Hierarchy) = False then
         Call := Build_Runtime_Call (Sloc (N), RE_Enter_Master);

         --  The block may have no declarations (and nevertheless be a task
         --  master) if it contains a call that may return an object that
         --  contains tasks.

         if No (Declarations (N)) then
            Set_Declarations (N, New_List (Call));
         else
            Prepend_To (Declarations (N), Call);
         end if;

         Analyze (Call);
      end if;
   end Establish_Task_Master;

   --------------------------------
   -- Expand_Accept_Declarations --
   --------------------------------

   --  Part of the expansion of an accept statement involves the creation of
   --  a declaration that can be referenced from the statement sequence of
   --  the accept:

   --    Ann : Address;

   --  This declaration is inserted immediately before the accept statement
   --  and it is important that it be inserted before the statements of the
   --  statement sequence are analyzed. Thus it would be too late to create
   --  this declaration in the Expand_N_Accept_Statement routine, which is
   --  why there is a separate procedure to be called directly from Sem_Ch9.

   --  Ann is used to hold the address of the record containing the parameters
   --  (see Expand_N_Entry_Call for more details on how this record is built).
   --  References to the parameters do an unchecked conversion of this address
   --  to a pointer to the required record type, and then access the field that
   --  holds the value of the required parameter. The entity for the address
   --  variable is held as the top stack element (i.e. the last element) of the
   --  Accept_Address stack in the corresponding entry entity, and this element
   --  must be set in place  before the statements are processed.

   --  The above description applies to the case of a stand alone accept
   --  statement, i.e. one not appearing as part of a select alternative.

   --  For the case of an accept that appears as part of a select alternative
   --  of a selective accept, we must still create the declaration right away,
   --  since Ann is needed immediately, but there is an important difference:

   --    The declaration is inserted before the selective accept, not before
   --    the accept statement (which is not part of a list anyway, and so would
   --    not accommodate inserted declarations)

   --    We only need one address variable for the entire selective accept. So
   --    the Ann declaration is created only for the first accept alternative,
   --    and subsequent accept alternatives reference the same Ann variable.

   --  We can distinguish the two cases by seeing whether the accept statement
   --  is part of a list. If not, then it must be in an accept alternative.

   --  To expand the requeue statement, a label is provided at the end of the
   --  accept statement or alternative of which it is a part, so that the
   --  statement can be skipped after the requeue is complete. This label is
   --  created here rather than during the expansion of the accept statement,
   --  because it will be needed by any requeue statements within the accept,
   --  which are expanded before the accept.

   procedure Expand_Accept_Declarations (N : Node_Id; Ent : Entity_Id) is
      Loc    : constant Source_Ptr := Sloc (N);
      Stats  : constant Node_Id    := Handled_Statement_Sequence (N);
      Ann    : Entity_Id           := Empty;
      Adecl  : Node_Id;
      Lab    : Node_Id;
      Ldecl  : Node_Id;
      Ldecl2 : Node_Id;

   begin
      if Expander_Active then

         --  If we have no handled statement sequence, we may need to build
         --  a dummy sequence consisting of a null statement. This can be
         --  skipped if the trivial accept optimization is permitted.

         if not Trivial_Accept_OK
           and then (No (Stats) or else Null_Statements (Statements (Stats)))
         then
            Set_Handled_Statement_Sequence (N,
              Make_Handled_Sequence_Of_Statements (Loc,
                Statements => New_List (Make_Null_Statement (Loc))));
         end if;

         --  Create and declare two labels to be placed at the end of the
         --  accept statement. The first label is used to allow requeues to
         --  skip the remainder of entry processing. The second label is used
         --  to skip the remainder of entry processing if the rendezvous
         --  completes in the middle of the accept body.

         if Present (Handled_Statement_Sequence (N)) then
            declare
               Ent : Entity_Id;

            begin
               Ent := Make_Temporary (Loc, 'L');
               Lab := Make_Label (Loc, New_Occurrence_Of (Ent, Loc));
               Ldecl :=
                 Make_Implicit_Label_Declaration (Loc,
                   Defining_Identifier  => Ent,
                   Label_Construct      => Lab);
               Append (Lab, Statements (Handled_Statement_Sequence (N)));

               Ent := Make_Temporary (Loc, 'L');
               Lab := Make_Label (Loc, New_Occurrence_Of (Ent, Loc));
               Ldecl2 :=
                 Make_Implicit_Label_Declaration (Loc,
                   Defining_Identifier  => Ent,
                   Label_Construct      => Lab);
               Append (Lab, Statements (Handled_Statement_Sequence (N)));
            end;

         else
            Ldecl  := Empty;
            Ldecl2 := Empty;
         end if;

         --  Case of stand alone accept statement

         if Is_List_Member (N) then

            if Present (Handled_Statement_Sequence (N)) then
               Ann := Make_Temporary (Loc, 'A');

               Adecl :=
                 Make_Object_Declaration (Loc,
                   Defining_Identifier => Ann,
                   Object_Definition   =>
                     New_Occurrence_Of (RTE (RE_Address), Loc));

               Insert_Before_And_Analyze (N, Adecl);
               Insert_Before_And_Analyze (N, Ldecl);
               Insert_Before_And_Analyze (N, Ldecl2);
            end if;

         --  Case of accept statement which is in an accept alternative

         else
            declare
               Acc_Alt : constant Node_Id := Parent (N);
               Sel_Acc : constant Node_Id := Parent (Acc_Alt);
               Alt     : Node_Id;

            begin
               pragma Assert (Nkind (Acc_Alt) = N_Accept_Alternative);
               pragma Assert (Nkind (Sel_Acc) = N_Selective_Accept);

               --  ??? Consider a single label for select statements

               if Present (Handled_Statement_Sequence (N)) then
                  Prepend (Ldecl2,
                     Statements (Handled_Statement_Sequence (N)));
                  Analyze (Ldecl2);

                  Prepend (Ldecl,
                     Statements (Handled_Statement_Sequence (N)));
                  Analyze (Ldecl);
               end if;

               --  Find first accept alternative of the selective accept. A
               --  valid selective accept must have at least one accept in it.

               Alt := First (Select_Alternatives (Sel_Acc));

               while Nkind (Alt) /= N_Accept_Alternative loop
                  Next (Alt);
               end loop;

               --  If this is the first accept statement, then we have to
               --  create the Ann variable, as for the stand alone case, except
               --  that it is inserted before the selective accept. Similarly,
               --  a label for requeue expansion must be declared.

               if N = Accept_Statement (Alt) then
                  Ann := Make_Temporary (Loc, 'A');
                  Adecl :=
                    Make_Object_Declaration (Loc,
                      Defining_Identifier => Ann,
                      Object_Definition   =>
                        New_Occurrence_Of (RTE (RE_Address), Loc));

                  Insert_Before_And_Analyze (Sel_Acc, Adecl);

               --  If this is not the first accept statement, then find the Ann
               --  variable allocated by the first accept and use it.

               else
                  Ann :=
                    Node (Last_Elmt (Accept_Address
                      (Entity (Entry_Direct_Name (Accept_Statement (Alt))))));
               end if;
            end;
         end if;

         --  Merge here with Ann either created or referenced, and Adecl
         --  pointing to the corresponding declaration. Remaining processing
         --  is the same for the two cases.

         if Present (Ann) then
            Append_Elmt (Ann, Accept_Address (Ent));
            Set_Debug_Info_Needed (Ann);
         end if;

         --  Create renaming declarations for the entry formals. Each reference
         --  to a formal becomes a dereference of a component of the parameter
         --  block, whose address is held in Ann. These declarations are
         --  eventually inserted into the accept block, and analyzed there so
         --  that they have the proper scope for gdb and do not conflict with
         --  other declarations.

         if Present (Parameter_Specifications (N))
           and then Present (Handled_Statement_Sequence (N))
         then
            declare
               Comp           : Entity_Id;
               Decl           : Node_Id;
               Formal         : Entity_Id;
               New_F          : Entity_Id;
               Renamed_Formal : Node_Id;

            begin
               Push_Scope (Ent);
               Formal := First_Formal (Ent);

               while Present (Formal) loop
                  Comp  := Entry_Component (Formal);
                  New_F := Make_Defining_Identifier (Loc, Chars (Formal));

                  Set_Etype (New_F, Etype (Formal));
                  Set_Scope (New_F, Ent);

                  --  Now we set debug info needed on New_F even though it does
                  --  not come from source, so that the debugger will get the
                  --  right information for these generated names.

                  Set_Debug_Info_Needed (New_F);

                  if Ekind (Formal) = E_In_Parameter then
                     Set_Ekind (New_F, E_Constant);
                  else
                     Set_Ekind (New_F, E_Variable);
                     Set_Extra_Constrained (New_F, Extra_Constrained (Formal));
                  end if;

                  Set_Actual_Subtype (New_F, Actual_Subtype (Formal));

                  Renamed_Formal :=
                     Make_Selected_Component (Loc,
                       Prefix        =>
                         Unchecked_Convert_To (
                           Entry_Parameters_Type (Ent),
                           New_Occurrence_Of (Ann, Loc)),
                       Selector_Name =>
                         New_Occurrence_Of (Comp, Loc));

                  Decl :=
                    Build_Renamed_Formal_Declaration
                      (New_F, Formal, Comp, Renamed_Formal);

                  if No (Declarations (N)) then
                     Set_Declarations (N, New_List);
                  end if;

                  Append (Decl, Declarations (N));
                  Set_Renamed_Object (Formal, New_F);
                  Next_Formal (Formal);
               end loop;

               End_Scope;
            end;
         end if;
      end if;
   end Expand_Accept_Declarations;

   ---------------------------------------------
   -- Expand_Access_Protected_Subprogram_Type --
   ---------------------------------------------

   procedure Expand_Access_Protected_Subprogram_Type (N : Node_Id) is
      Loc    : constant Source_Ptr := Sloc (N);
      T      : constant Entity_Id  := Defining_Identifier (N);
      D_T    : constant Entity_Id  := Designated_Type (T);
      D_T2   : constant Entity_Id  := Make_Temporary (Loc, 'D');
      E_T    : constant Entity_Id  := Make_Temporary (Loc, 'E');
      P_List : constant List_Id    :=
                 Build_Protected_Spec (N, RTE (RE_Address), D_T, False);

      Comps : List_Id;
      Decl1 : Node_Id;
      Decl2 : Node_Id;
      Def1  : Node_Id;

   begin
      --  Create access to subprogram with full signature

      if Etype (D_T) /= Standard_Void_Type then
         Def1 :=
           Make_Access_Function_Definition (Loc,
             Parameter_Specifications => P_List,
             Result_Definition =>
               Copy_Result_Type (Result_Definition (Type_Definition (N))));

      else
         Def1 :=
           Make_Access_Procedure_Definition (Loc,
             Parameter_Specifications => P_List);
      end if;

      Decl1 :=
        Make_Full_Type_Declaration (Loc,
          Defining_Identifier => D_T2,
          Type_Definition     => Def1);

      --  Declare the new types before the original one since the latter will
      --  refer to them through the Equivalent_Type slot.

      Insert_Before_And_Analyze (N, Decl1);

      --  Associate the access to subprogram with its original access to
      --  protected subprogram type. Needed by the backend to know that this
      --  type corresponds with an access to protected subprogram type.

      Set_Original_Access_Type (D_T2, T);

      --  Create Equivalent_Type, a record with two components for an access to
      --  object and an access to subprogram.

      Comps := New_List (
        Make_Component_Declaration (Loc,
          Defining_Identifier  => Make_Temporary (Loc, 'P'),
          Component_Definition =>
            Make_Component_Definition (Loc,
              Aliased_Present    => False,
              Subtype_Indication =>
                New_Occurrence_Of (RTE (RE_Address), Loc))),

        Make_Component_Declaration (Loc,
          Defining_Identifier  => Make_Temporary (Loc, 'S'),
          Component_Definition =>
            Make_Component_Definition (Loc,
              Aliased_Present    => False,
              Subtype_Indication => New_Occurrence_Of (D_T2, Loc))));

      Decl2 :=
        Make_Full_Type_Declaration (Loc,
          Defining_Identifier => E_T,
          Type_Definition     =>
            Make_Record_Definition (Loc,
              Component_List =>
                Make_Component_List (Loc, Component_Items => Comps)));

      Insert_Before_And_Analyze (N, Decl2);
      Set_Equivalent_Type (T, E_T);
   end Expand_Access_Protected_Subprogram_Type;

   --------------------------
   -- Expand_Entry_Barrier --
   --------------------------

   procedure Expand_Entry_Barrier (N : Node_Id; Ent : Entity_Id) is
      Cond      : constant Node_Id   :=
                    Condition (Entry_Body_Formal_Part (N));
      Prot      : constant Entity_Id := Scope (Ent);
      Spec_Decl : constant Node_Id   := Parent (Prot);
      Func      : Entity_Id          := Empty;
      B_F       : Node_Id;
      Body_Decl : Node_Id;

      function Is_Global_Entity (N : Node_Id) return Traverse_Result;
      --  Check whether entity in Barrier is external to protected type.
      --  If so, barrier may not be properly synchronized.

      function Is_Pure_Barrier (N : Node_Id) return Traverse_Result;
      --  Check whether N follows the Pure_Barriers restriction. Return OK if
      --  so.

      function Is_Simple_Barrier_Name (N : Node_Id) return Boolean;
      --  Check whether entity name N denotes a component of the protected
      --  object. This is used to check the Simple_Barrier restriction.

      ----------------------
      -- Is_Global_Entity --
      ----------------------

      function Is_Global_Entity (N : Node_Id) return Traverse_Result is
         E : Entity_Id;
         S : Entity_Id;

      begin
         if Is_Entity_Name (N) and then Present (Entity (N)) then
            E := Entity (N);
            S := Scope  (E);

            if Ekind (E) = E_Variable then

               --  If the variable is local to the barrier function generated
               --  during expansion, it is ok. If expansion is not performed,
               --  then Func is Empty so this test cannot succeed.

               if Scope (E) = Func then
                  null;

               --  A protected call from a barrier to another object is ok

               elsif Ekind (Etype (E)) = E_Protected_Type then
                  null;

               --  If the variable is within the package body we consider
               --  this safe. This is a common (if dubious) idiom.

               elsif S = Scope (Prot)
                 and then Ekind_In (S, E_Package, E_Generic_Package)
                 and then Nkind (Parent (E)) = N_Object_Declaration
                 and then Nkind (Parent (Parent (E))) = N_Package_Body
               then
                  null;

               else
                  Error_Msg_N ("potentially unsynchronized barrier??", N);
                  Error_Msg_N ("\& should be private component of type??", N);
               end if;
            end if;
         end if;

         return OK;
      end Is_Global_Entity;

      procedure Check_Unprotected_Barrier is
        new Traverse_Proc (Is_Global_Entity);

      ----------------------------
      -- Is_Simple_Barrier_Name --
      ----------------------------

      function Is_Simple_Barrier_Name (N : Node_Id) return Boolean is
         Renamed : Node_Id;

      begin
         --  Check for case of _object.all.field (note that the explicit
         --  dereference gets inserted by analyze/expand of _object.field).

         if Expander_Active then
            Renamed := Renamed_Object (Entity (N));

            return
              Present (Renamed)
                and then Nkind (Renamed) = N_Selected_Component
                and then Chars (Prefix (Prefix (Renamed))) = Name_uObject;
         else
            return Scope (Entity (N)) = Current_Scope;
         end if;
      end Is_Simple_Barrier_Name;

      ---------------------
      -- Is_Pure_Barrier --
      ---------------------

      function Is_Pure_Barrier (N : Node_Id) return Traverse_Result is
      begin
         case Nkind (N) is
            when N_Expanded_Name |
                 N_Identifier    =>
               if No (Entity (N)) then
                  return Abandon;
               end if;

               case Ekind (Entity (N)) is
                  when E_Constant            |
                       E_Discriminant        |
                       E_Named_Integer       |
                       E_Named_Real          |
                       E_Enumeration_Literal =>
                     return OK;

                  when E_Component |
                       E_Variable  =>

                     --  A variable in the protected type is expanded as a
                     --  component.

                     if Is_Simple_Barrier_Name (N) then
                        return OK;
                     end if;

                  when others =>
                     null;
               end case;

            when N_Integer_Literal   |
                 N_Real_Literal      |
                 N_Character_Literal =>
               return OK;

            when N_Op_Boolean |
                 N_Op_Not     =>
               if Ekind (Entity (N)) = E_Operator then
                  return OK;
               end if;

            when N_Short_Circuit =>
               return OK;

            when others =>
               null;
         end case;

         return Abandon;
      end Is_Pure_Barrier;

      function Check_Pure_Barriers is new Traverse_Func (Is_Pure_Barrier);

   --  Start of processing for Expand_Entry_Barrier

   begin
      if No_Run_Time_Mode then
         Error_Msg_CRT ("entry barrier", N);
         return;
      end if;

      --  The body of the entry barrier must be analyzed in the context of the
      --  protected object, but its scope is external to it, just as any other
      --  unprotected version of a protected operation. The specification has
      --  been produced when the protected type declaration was elaborated. We
      --  build the body, insert it in the enclosing scope, but analyze it in
      --  the current context. A more uniform approach would be to treat the
      --  barrier just as a protected function, and discard the protected
      --  version of it because it is never called.

      if Expander_Active then
         B_F  := Build_Barrier_Function (N, Ent, Prot);
         Func := Barrier_Function (Ent);
         Set_Corresponding_Spec (B_F, Func);

         Body_Decl := Parent (Corresponding_Body (Spec_Decl));

         if Nkind (Parent (Body_Decl)) = N_Subunit then
            Body_Decl := Corresponding_Stub (Parent (Body_Decl));
         end if;

         Insert_Before_And_Analyze (Body_Decl, B_F);

         Set_Discriminals (Spec_Decl);
         Set_Scope (Func, Scope (Prot));

      else
         Analyze_And_Resolve (Cond, Any_Boolean);
      end if;

      --  Check Pure_Barriers restriction

      if Check_Pure_Barriers (Cond) = Abandon then
         Check_Restriction (Pure_Barriers, Cond);
      end if;

      --  The Ravenscar profile restricts barriers to simple variables declared
      --  within the protected object. We also allow Boolean constants, since
      --  these appear in several published examples and are also allowed by
      --  other compilers.

      --  Note that after analysis variables in this context will be replaced
      --  by the corresponding prival, that is to say a renaming of a selected
      --  component of the form _Object.Var. If expansion is disabled, as
      --  within a generic, we check that the entity appears in the current
      --  scope.

      if Is_Entity_Name (Cond) then

         --  A small optimization of useless renamings. If the scope of the
         --  entity of the condition is not the barrier function, then the
         --  condition does not reference any of the generated renamings
         --  within the function.

         if Expander_Active and then Scope (Entity (Cond)) /= Func then
            Set_Declarations (B_F, Empty_List);
         end if;

         if Entity (Cond) = Standard_False
              or else
            Entity (Cond) = Standard_True
         then
            return;

         elsif Is_Simple_Barrier_Name (Cond) then
            return;
         end if;
      end if;

      --  It is not a boolean variable or literal, so check the restriction.
      --  Note that it is safe to be calling Check_Restriction from here, even
      --  though this is part of the expander, since Expand_Entry_Barrier is
      --  called from Sem_Ch9 even in -gnatc mode.

      Check_Restriction (Simple_Barriers, Cond);

      --  Emit warning if barrier contains global entities and is thus
      --  potentially unsynchronized.

      Check_Unprotected_Barrier (Cond);
   end Expand_Entry_Barrier;

   ------------------------------
   -- Expand_N_Abort_Statement --
   ------------------------------

   --  Expand abort T1, T2, .. Tn; into:
   --    Abort_Tasks (Task_List'(1 => T1.Task_Id, 2 => T2.Task_Id ...))

   procedure Expand_N_Abort_Statement (N : Node_Id) is
      Loc    : constant Source_Ptr := Sloc (N);
      Tlist  : constant List_Id    := Names (N);
      Count  : Nat;
      Aggr   : Node_Id;
      Tasknm : Node_Id;

   begin
      Aggr := Make_Aggregate (Loc, Component_Associations => New_List);
      Count := 0;

      Tasknm := First (Tlist);

      while Present (Tasknm) loop
         Count := Count + 1;

         --  A task interface class-wide type object is being aborted. Retrieve
         --  its _task_id by calling a dispatching routine.

         if Ada_Version >= Ada_2005
           and then Ekind (Etype (Tasknm)) = E_Class_Wide_Type
           and then Is_Interface (Etype (Tasknm))
           and then Is_Task_Interface (Etype (Tasknm))
         then
            Append_To (Component_Associations (Aggr),
              Make_Component_Association (Loc,
                Choices    => New_List (Make_Integer_Literal (Loc, Count)),
                Expression =>

                  --  Task_Id (Tasknm._disp_get_task_id)

                  Make_Unchecked_Type_Conversion (Loc,
                    Subtype_Mark =>
                      New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
                    Expression   =>
                      Make_Selected_Component (Loc,
                        Prefix        => New_Copy_Tree (Tasknm),
                        Selector_Name =>
                          Make_Identifier (Loc, Name_uDisp_Get_Task_Id)))));

         else
            Append_To (Component_Associations (Aggr),
              Make_Component_Association (Loc,
                Choices    => New_List (Make_Integer_Literal (Loc, Count)),
                Expression => Concurrent_Ref (Tasknm)));
         end if;

         Next (Tasknm);
      end loop;

      Rewrite (N,
        Make_Procedure_Call_Statement (Loc,
          Name => New_Occurrence_Of (RTE (RE_Abort_Tasks), Loc),
          Parameter_Associations => New_List (
            Make_Qualified_Expression (Loc,
              Subtype_Mark => New_Occurrence_Of (RTE (RE_Task_List), Loc),
              Expression   => Aggr))));

      Analyze (N);
   end Expand_N_Abort_Statement;

   -------------------------------
   -- Expand_N_Accept_Statement --
   -------------------------------

   --  This procedure handles expansion of accept statements that stand alone,
   --  i.e. they are not part of an accept alternative. The expansion of
   --  accept statement in accept alternatives is handled by the routines
   --  Expand_N_Accept_Alternative and Expand_N_Selective_Accept. The
   --  following description applies only to stand alone accept statements.

   --  If there is no handled statement sequence, or only null statements, then
   --  this is called a trivial accept, and the expansion is:

   --    Accept_Trivial (entry-index)

   --  If there is a handled statement sequence, then the expansion is:

   --    Ann : Address;
   --    {Lnn : Label}

   --    begin
   --       begin
   --          Accept_Call (entry-index, Ann);
   --          Renaming_Declarations for formals
   --          <statement sequence from N_Accept_Statement node>
   --          Complete_Rendezvous;
   --          <<Lnn>>
   --
   --       exception
   --          when ... =>
   --             <exception handler from N_Accept_Statement node>
   --             Complete_Rendezvous;
   --          when ... =>
   --             <exception handler from N_Accept_Statement node>
   --             Complete_Rendezvous;
   --          ...
   --       end;

   --    exception
   --       when all others =>
   --          Exceptional_Complete_Rendezvous (Get_GNAT_Exception);
   --    end;

   --  The first three declarations were already inserted ahead of the accept
   --  statement by the Expand_Accept_Declarations procedure, which was called
   --  directly from the semantics during analysis of the accept statement,
   --  before analyzing its contained statements.

   --  The declarations from the N_Accept_Statement, as noted in Sinfo, come
   --  from possible expansion activity (the original source of course does
   --  not have any declarations associated with the accept statement, since
   --  an accept statement has no declarative part). In particular, if the
   --  expander is active, the first such declaration is the declaration of
   --  the Accept_Params_Ptr entity (see Sem_Ch9.Analyze_Accept_Statement).

   --  The two blocks are merged into a single block if the inner block has
   --  no exception handlers, but otherwise two blocks are required, since
   --  exceptions might be raised in the exception handlers of the inner
   --  block, and Exceptional_Complete_Rendezvous must be called.

   procedure Expand_N_Accept_Statement (N : Node_Id) is
      Loc     : constant Source_Ptr := Sloc (N);
      Stats   : constant Node_Id    := Handled_Statement_Sequence (N);
      Ename   : constant Node_Id    := Entry_Direct_Name (N);
      Eindx   : constant Node_Id    := Entry_Index (N);
      Eent    : constant Entity_Id  := Entity (Ename);
      Acstack : constant Elist_Id   := Accept_Address (Eent);
      Ann     : constant Entity_Id  := Node (Last_Elmt (Acstack));
      Ttyp    : constant Entity_Id  := Etype (Scope (Eent));
      Blkent  : Entity_Id;
      Call    : Node_Id;
      Block   : Node_Id;

   begin
      --  If the accept statement is not part of a list, then its parent must
      --  be an accept alternative, and, as described above, we do not do any
      --  expansion for such accept statements at this level.

      if not Is_List_Member (N) then
         pragma Assert (Nkind (Parent (N)) = N_Accept_Alternative);
         return;

      --  Trivial accept case (no statement sequence, or null statements).
      --  If the accept statement has declarations, then just insert them
      --  before the procedure call.

      elsif Trivial_Accept_OK
        and then (No (Stats) or else Null_Statements (Statements (Stats)))
      then
         --  Remove declarations for renamings, because the parameter block
         --  will not be assigned.

         declare
            D      : Node_Id;
            Next_D : Node_Id;

         begin
            D := First (Declarations (N));
            while Present (D) loop
               Next_D := Next (D);
               if Nkind (D) = N_Object_Renaming_Declaration then
                  Remove (D);
               end if;

               D := Next_D;
            end loop;
         end;

         if Present (Declarations (N)) then
            Insert_Actions (N, Declarations (N));
         end if;

         Rewrite (N,
           Make_Procedure_Call_Statement (Loc,
             Name => New_Occurrence_Of (RTE (RE_Accept_Trivial), Loc),
             Parameter_Associations => New_List (
               Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp))));

         Analyze (N);

         --  Discard Entry_Address that was created for it, so it will not be
         --  emitted if this accept statement is in the statement part of a
         --  delay alternative.

         if Present (Stats) then
            Remove_Last_Elmt (Acstack);
         end if;

      --  Case of statement sequence present

      else
         --  Construct the block, using the declarations from the accept
         --  statement if any to initialize the declarations of the block.

         Blkent := Make_Temporary (Loc, 'A');
         Set_Ekind (Blkent, E_Block);
         Set_Etype (Blkent, Standard_Void_Type);
         Set_Scope (Blkent, Current_Scope);

         Block :=
           Make_Block_Statement (Loc,
             Identifier                 => New_Occurrence_Of (Blkent, Loc),
             Declarations               => Declarations (N),
             Handled_Statement_Sequence => Build_Accept_Body (N));

         --  For the analysis of the generated declarations, the parent node
         --  must be properly set.

         Set_Parent (Block, Parent (N));

         --  Prepend call to Accept_Call to main statement sequence If the
         --  accept has exception handlers, the statement sequence is wrapped
         --  in a block. Insert call and renaming declarations in the
         --  declarations of the block, so they are elaborated before the
         --  handlers.

         Call :=
           Make_Procedure_Call_Statement (Loc,
             Name => New_Occurrence_Of (RTE (RE_Accept_Call), Loc),
             Parameter_Associations => New_List (
               Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp),
               New_Occurrence_Of (Ann, Loc)));

         if Parent (Stats) = N then
            Prepend (Call, Statements (Stats));
         else
            Set_Declarations (Parent (Stats), New_List (Call));
         end if;

         Analyze (Call);

         Push_Scope (Blkent);

         declare
            D      : Node_Id;
            Next_D : Node_Id;
            Typ    : Entity_Id;

         begin
            D := First (Declarations (N));
            while Present (D) loop
               Next_D := Next (D);

               if Nkind (D) = N_Object_Renaming_Declaration then

                  --  The renaming declarations for the formals were created
                  --  during analysis of the accept statement, and attached to
                  --  the list of declarations. Place them now in the context
                  --  of the accept block or subprogram.

                  Remove (D);
                  Typ := Entity (Subtype_Mark (D));
                  Insert_After (Call, D);
                  Analyze (D);

                  --  If the formal is class_wide, it does not have an actual
                  --  subtype. The analysis of the renaming declaration creates
                  --  one, but we need to retain the class-wide nature of the
                  --  entity.

                  if Is_Class_Wide_Type (Typ) then
                     Set_Etype (Defining_Identifier (D), Typ);
                  end if;

               end if;

               D := Next_D;
            end loop;
         end;

         End_Scope;

         --  Replace the accept statement by the new block

         Rewrite (N, Block);
         Analyze (N);

         --  Last step is to unstack the Accept_Address value

         Remove_Last_Elmt (Acstack);
      end if;
   end Expand_N_Accept_Statement;

   ----------------------------------
   -- Expand_N_Asynchronous_Select --
   ----------------------------------

   --  This procedure assumes that the trigger statement is an entry call or
   --  a dispatching procedure call. A delay alternative should already have
   --  been expanded into an entry call to the appropriate delay object Wait
   --  entry.

   --  If the trigger is a task entry call, the select is implemented with
   --  a Task_Entry_Call:

   --    declare
   --       B : Boolean;
   --       C : Boolean;
   --       P : parms := (parm, parm, parm);

   --        --  Clean is added by Exp_Ch7.Expand_Cleanup_Actions

   --       procedure _clean is
   --       begin
   --          ...
   --          Cancel_Task_Entry_Call (C);
   --          ...
   --       end _clean;

   --    begin
   --       Abort_Defer;
   --       Task_Entry_Call
   --         (<acceptor-task>,    --  Acceptor
   --          <entry-index>,      --  E
   --          P'Address,          --  Uninterpreted_Data
   --          Asynchronous_Call,  --  Mode
   --          B);                 --  Rendezvous_Successful

   --       begin
   --          begin
   --             Abort_Undefer;
   --             <abortable-part>
   --          at end
   --             _clean;  --  Added by Exp_Ch7.Expand_Cleanup_Actions
   --          end;
   --       exception
   --          when Abort_Signal => Abort_Undefer;
   --       end;

   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --       if not C then
   --          <triggered-statements>
   --       end if;
   --    end;

   --  Note that Build_Simple_Entry_Call is used to expand the entry of the
   --  asynchronous entry call (by Expand_N_Entry_Call_Statement procedure)
   --  as follows:

   --    declare
   --       P : parms := (parm, parm, parm);
   --    begin
   --       Call_Simple (acceptor-task, entry-index, P'Address);
   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --    end;

   --  so the task at hand is to convert the latter expansion into the former

   --  If the trigger is a protected entry call, the select is implemented
   --  with Protected_Entry_Call:

   --  declare
   --     P   : E1_Params := (param, param, param);
   --     Bnn : Communications_Block;

   --  begin
   --     declare

   --        --  Clean is added by Exp_Ch7.Expand_Cleanup_Actions

   --        procedure _clean is
   --        begin
   --           ...
   --           if Enqueued (Bnn) then
   --              Cancel_Protected_Entry_Call (Bnn);
   --           end if;
   --           ...
   --        end _clean;

   --     begin
   --        begin
   --           Protected_Entry_Call
   --             (po._object'Access,  --  Object
   --              <entry index>,      --  E
   --              P'Address,          --  Uninterpreted_Data
   --              Asynchronous_Call,  --  Mode
   --              Bnn);               --  Block

   --           if Enqueued (Bnn) then
   --              <abortable-part>
   --           end if;
   --        at end
   --           _clean;  --  Added by Exp_Ch7.Expand_Cleanup_Actions
   --        end;
   --     exception
   --        when Abort_Signal => Abort_Undefer;
   --     end;

   --     if not Cancelled (Bnn) then
   --        <triggered-statements>
   --     end if;
   --  end;

   --  Build_Simple_Entry_Call is used to expand the all to a simple protected
   --  entry call:

   --  declare
   --     P   : E1_Params := (param, param, param);
   --     Bnn : Communications_Block;

   --  begin
   --     Protected_Entry_Call
   --       (po._object'Access,  --  Object
   --        <entry index>,      --  E
   --        P'Address,          --  Uninterpreted_Data
   --        Simple_Call,        --  Mode
   --        Bnn);               --  Block
   --     parm := P.param;
   --     parm := P.param;
   --       ...
   --  end;

   --  Ada 2005 (AI-345): If the trigger is a dispatching call, the select is
   --  expanded into:

   --    declare
   --       B   : Boolean := False;
   --       Bnn : Communication_Block;
   --       C   : Ada.Tags.Prim_Op_Kind;
   --       D   : System.Storage_Elements.Dummy_Communication_Block;
   --       K   : Ada.Tags.Tagged_Kind :=
   --               Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag (<object>));
   --       P   : Parameters := (Param1 .. ParamN);
   --       S   : Integer;
   --       U   : Boolean;

   --    begin
   --       if K = Ada.Tags.TK_Limited_Tagged
   --         or else K = Ada.Tags.TK_Tagged
   --       then
   --          <dispatching-call>;
   --          <triggering-statements>;

   --       else
   --          S :=
   --            Ada.Tags.Get_Offset_Index
   --              (Ada.Tags.Tag (<object>), DT_Position (<dispatching-call>));

   --          _Disp_Get_Prim_Op_Kind (<object>, S, C);

   --          if C = POK_Protected_Entry then
   --             declare
   --                procedure _clean is
   --                begin
   --                   if Enqueued (Bnn) then
   --                      Cancel_Protected_Entry_Call (Bnn);
   --                   end if;
   --                end _clean;

   --             begin
   --                begin
   --                   _Disp_Asynchronous_Select
   --                     (<object>, S, P'Address, D, B);
   --                   Bnn := Communication_Block (D);

   --                   Param1 := P.Param1;
   --                   ...
   --                   ParamN := P.ParamN;

   --                   if Enqueued (Bnn) then
   --                      <abortable-statements>
   --                   end if;
   --                at end
   --                   _clean;  --  Added by Exp_Ch7.Expand_Cleanup_Actions
   --                end;
   --             exception
   --                when Abort_Signal => Abort_Undefer;
   --             end;

   --             if not Cancelled (Bnn) then
   --                <triggering-statements>
   --             end if;

   --          elsif C = POK_Task_Entry then
   --             declare
   --                procedure _clean is
   --                begin
   --                   Cancel_Task_Entry_Call (U);
   --                end _clean;

   --             begin
   --                Abort_Defer;

   --                _Disp_Asynchronous_Select
   --                  (<object>, S, P'Address, D, B);
   --                Bnn := Communication_Bloc (D);

   --                Param1 := P.Param1;
   --                ...
   --                ParamN := P.ParamN;

   --                begin
   --                   begin
   --                      Abort_Undefer;
   --                      <abortable-statements>
   --                   at end
   --                      _clean;  --  Added by Exp_Ch7.Expand_Cleanup_Actions
   --                   end;
   --                exception
   --                   when Abort_Signal => Abort_Undefer;
   --                end;

   --                if not U then
   --                   <triggering-statements>
   --                end if;
   --             end;

   --          else
   --             <dispatching-call>;
   --             <triggering-statements>
   --          end if;
   --       end if;
   --    end;

   --  The job is to convert this to the asynchronous form

   --  If the trigger is a delay statement, it will have been expanded into
   --  a call to one of the GNARL delay procedures. This routine will convert
   --  this into a protected entry call on a delay object and then continue
   --  processing as for a protected entry call trigger. This requires
   --  declaring a Delay_Block object and adding a pointer to this object to
   --  the parameter list of the delay procedure to form the parameter list of
   --  the entry call. This object is used by the runtime to queue the delay
   --  request.

   --  For a description of the use of P and the assignments after the call,
   --  see Expand_N_Entry_Call_Statement.

   procedure Expand_N_Asynchronous_Select (N : Node_Id) is
      Loc  : constant Source_Ptr := Sloc (N);
      Abrt : constant Node_Id    := Abortable_Part (N);
      Trig : constant Node_Id    := Triggering_Alternative (N);

      Abort_Block_Ent   : Entity_Id;
      Abortable_Block   : Node_Id;
      Actuals           : List_Id;
      Astats            : List_Id;
      Blk_Ent           : constant Entity_Id := Make_Temporary (Loc, 'A');
      Blk_Typ           : Entity_Id;
      Call              : Node_Id;
      Call_Ent          : Entity_Id;
      Cancel_Param      : Entity_Id;
      Cleanup_Block     : Node_Id;
      Cleanup_Block_Ent : Entity_Id;
      Cleanup_Stmts     : List_Id;
      Conc_Typ_Stmts    : List_Id;
      Concval           : Node_Id;
      Dblock_Ent        : Entity_Id;
      Decl              : Node_Id;
      Decls             : List_Id;
      Ecall             : Node_Id;
      Ename             : Node_Id;
      Enqueue_Call      : Node_Id;
      Formals           : List_Id;
      Hdle              : List_Id;
      Handler_Stmt      : Node_Id;
      Index             : Node_Id;
      Lim_Typ_Stmts     : List_Id;
      N_Orig            : Node_Id;
      Obj               : Entity_Id;
      Param             : Node_Id;
      Params            : List_Id;
      Pdef              : Entity_Id;
      ProtE_Stmts       : List_Id;
      ProtP_Stmts       : List_Id;
      Stmt              : Node_Id;
      Stmts             : List_Id;
      TaskE_Stmts       : List_Id;
      Tstats            : List_Id;

      B   : Entity_Id;  --  Call status flag
      Bnn : Entity_Id;  --  Communication block
      C   : Entity_Id;  --  Call kind
      K   : Entity_Id;  --  Tagged kind
      P   : Entity_Id;  --  Parameter block
      S   : Entity_Id;  --  Primitive operation slot
      T   : Entity_Id;  --  Additional status flag

      procedure Rewrite_Abortable_Part;
      --  If the trigger is a dispatching call, the expansion inserts multiple
      --  copies of the abortable part. This is both inefficient, and may lead
      --  to duplicate definitions that the back-end will reject, when the
      --  abortable part includes loops. This procedure rewrites the abortable
      --  part into a call to a generated procedure.

      ----------------------------
      -- Rewrite_Abortable_Part --
      ----------------------------

      procedure Rewrite_Abortable_Part is
         Proc : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
         Decl : Node_Id;

      begin
         Decl :=
           Make_Subprogram_Body (Loc,
             Specification              =>
               Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc),
             Declarations               => New_List,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Astats));
         Insert_Before (N, Decl);
         Analyze (Decl);

         --  Rewrite abortable part into a call to this procedure.

         Astats :=
           New_List (
             Make_Procedure_Call_Statement (Loc,
               Name => New_Occurrence_Of (Proc, Loc)));
      end Rewrite_Abortable_Part;

   --  Start of processing for Expand_N_Asynchronous_Select

   begin
      --  Asynchronous select is not supported on restricted runtimes. Don't
      --  try to expand.

      if Restricted_Profile then
         return;
      end if;

      Process_Statements_For_Controlled_Objects (Trig);
      Process_Statements_For_Controlled_Objects (Abrt);

      Ecall := Triggering_Statement (Trig);

      Ensure_Statement_Present (Sloc (Ecall), Trig);

      --  Retrieve Astats and Tstats now because the finalization machinery may
      --  wrap them in blocks.

      Astats := Statements (Abrt);
      Tstats := Statements (Trig);

      --  The arguments in the call may require dynamic allocation, and the
      --  call statement may have been transformed into a block. The block
      --  may contain additional declarations for internal entities, and the
      --  original call is found by sequential search.

      if Nkind (Ecall) = N_Block_Statement then
         Ecall := First (Statements (Handled_Statement_Sequence (Ecall)));
         while not Nkind_In (Ecall, N_Procedure_Call_Statement,
                                    N_Entry_Call_Statement)
         loop
            Next (Ecall);
         end loop;
      end if;

      --  This is either a dispatching call or a delay statement used as a
      --  trigger which was expanded into a procedure call.

      if Nkind (Ecall) = N_Procedure_Call_Statement then
         if Ada_Version >= Ada_2005
           and then
             (No (Original_Node (Ecall))
               or else not Nkind_In (Original_Node (Ecall),
                                     N_Delay_Relative_Statement,
                                     N_Delay_Until_Statement))
         then
            Extract_Dispatching_Call (Ecall, Call_Ent, Obj, Actuals, Formals);

            Rewrite_Abortable_Part;
            Decls := New_List;
            Stmts := New_List;

            --  Call status flag processing, generate:
            --    B : Boolean := False;

            B := Build_B (Loc, Decls);

            --  Communication block processing, generate:
            --    Bnn : Communication_Block;

            Bnn := Make_Temporary (Loc, 'B');
            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Defining_Identifier => Bnn,
                Object_Definition   =>
                  New_Occurrence_Of (RTE (RE_Communication_Block), Loc)));

            --  Call kind processing, generate:
            --    C : Ada.Tags.Prim_Op_Kind;

            C := Build_C (Loc, Decls);

            --  Tagged kind processing, generate:
            --    K : Ada.Tags.Tagged_Kind :=
            --          Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag (<object>));

            --  Dummy communication block, generate:
            --    D : Dummy_Communication_Block;

            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc, Name_uD),
                Object_Definition   =>
                  New_Occurrence_Of
                    (RTE (RE_Dummy_Communication_Block), Loc)));

            K := Build_K (Loc, Decls, Obj);

            --  Parameter block processing

            Blk_Typ := Build_Parameter_Block
                         (Loc, Actuals, Formals, Decls);
            P       := Parameter_Block_Pack
                         (Loc, Blk_Typ, Actuals, Formals, Decls, Stmts);

            --  Dispatch table slot processing, generate:
            --    S : Integer;

            S := Build_S (Loc, Decls);

            --  Additional status flag processing, generate:
            --    Tnn : Boolean;

            T := Make_Temporary (Loc, 'T');
            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Defining_Identifier => T,
                Object_Definition   =>
                  New_Occurrence_Of (Standard_Boolean, Loc)));

            ------------------------------
            -- Protected entry handling --
            ------------------------------

            --  Generate:
            --    Param1 := P.Param1;
            --    ...
            --    ParamN := P.ParamN;

            Cleanup_Stmts := Parameter_Block_Unpack (Loc, P, Actuals, Formals);

            --  Generate:
            --    Bnn := Communication_Block (D);

            Prepend_To (Cleanup_Stmts,
              Make_Assignment_Statement (Loc,
                Name       => New_Occurrence_Of (Bnn, Loc),
                Expression =>
                  Make_Unchecked_Type_Conversion (Loc,
                    Subtype_Mark =>
                      New_Occurrence_Of (RTE (RE_Communication_Block), Loc),
                    Expression   => Make_Identifier (Loc, Name_uD))));

            --  Generate:
            --    _Disp_Asynchronous_Select (<object>, S, P'Address, D, B);

            Prepend_To (Cleanup_Stmts,
              Make_Procedure_Call_Statement (Loc,
                Name =>
                  New_Occurrence_Of
                    (Find_Prim_Op
                       (Etype (Etype (Obj)), Name_uDisp_Asynchronous_Select),
                     Loc),
                Parameter_Associations =>
                  New_List (
                    New_Copy_Tree (Obj),             --  <object>
                    New_Occurrence_Of (S, Loc),       --  S
                    Make_Attribute_Reference (Loc,   --  P'Address
                      Prefix         => New_Occurrence_Of (P, Loc),
                      Attribute_Name => Name_Address),
                    Make_Identifier (Loc, Name_uD),  --  D
                    New_Occurrence_Of (B, Loc))));    --  B

            --  Generate:
            --    if Enqueued (Bnn) then
            --       <abortable-statements>
            --    end if;

            Append_To (Cleanup_Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Function_Call (Loc,
                    Name =>
                      New_Occurrence_Of (RTE (RE_Enqueued), Loc),
                    Parameter_Associations =>
                      New_List (New_Occurrence_Of (Bnn, Loc))),

                Then_Statements =>
                  New_Copy_List_Tree (Astats)));

            --  Wrap the statements in a block. Exp_Ch7.Expand_Cleanup_Actions
            --  will then generate a _clean for the communication block Bnn.

            --  Generate:
            --    declare
            --       procedure _clean is
            --       begin
            --          if Enqueued (Bnn) then
            --             Cancel_Protected_Entry_Call (Bnn);
            --          end if;
            --       end _clean;
            --    begin
            --       Cleanup_Stmts
            --    at end
            --       _clean;
            --    end;

            Cleanup_Block_Ent := Make_Temporary (Loc, 'C');
            Cleanup_Block :=
              Build_Cleanup_Block (Loc, Cleanup_Block_Ent, Cleanup_Stmts, Bnn);

            --  Wrap the cleanup block in an exception handling block

            --  Generate:
            --    begin
            --       Cleanup_Block
            --    exception
            --       when Abort_Signal => Abort_Undefer;
            --    end;

            Abort_Block_Ent := Make_Temporary (Loc, 'A');
            ProtE_Stmts :=
              New_List (
                Make_Implicit_Label_Declaration (Loc,
                  Defining_Identifier => Abort_Block_Ent),

                Build_Abort_Block
                  (Loc, Abort_Block_Ent, Cleanup_Block_Ent, Cleanup_Block));

            --  Generate:
            --    if not Cancelled (Bnn) then
            --       <triggering-statements>
            --    end if;

            Append_To (ProtE_Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Op_Not (Loc,
                    Right_Opnd =>
                      Make_Function_Call (Loc,
                        Name =>
                          New_Occurrence_Of (RTE (RE_Cancelled), Loc),
                        Parameter_Associations =>
                          New_List (New_Occurrence_Of (Bnn, Loc)))),

                Then_Statements =>
                  New_Copy_List_Tree (Tstats)));

            -------------------------
            -- Task entry handling --
            -------------------------

            --  Generate:
            --    Param1 := P.Param1;
            --    ...
            --    ParamN := P.ParamN;

            TaskE_Stmts := Parameter_Block_Unpack (Loc, P, Actuals, Formals);

            --  Generate:
            --    Bnn := Communication_Block (D);

            Append_To (TaskE_Stmts,
              Make_Assignment_Statement (Loc,
                Name =>
                  New_Occurrence_Of (Bnn, Loc),
                Expression =>
                  Make_Unchecked_Type_Conversion (Loc,
                    Subtype_Mark =>
                      New_Occurrence_Of (RTE (RE_Communication_Block), Loc),
                    Expression   => Make_Identifier (Loc, Name_uD))));

            --  Generate:
            --    _Disp_Asynchronous_Select (<object>, S, P'Address, D, B);

            Prepend_To (TaskE_Stmts,
              Make_Procedure_Call_Statement (Loc,
                Name =>
                  New_Occurrence_Of (
                    Find_Prim_Op (Etype (Etype (Obj)),
                      Name_uDisp_Asynchronous_Select),
                    Loc),

                Parameter_Associations => New_List (
                  New_Copy_Tree (Obj),             --  <object>
                  New_Occurrence_Of (S, Loc),      --  S
                  Make_Attribute_Reference (Loc,   --  P'Address
                    Prefix         => New_Occurrence_Of (P, Loc),
                    Attribute_Name => Name_Address),
                  Make_Identifier (Loc, Name_uD),  --  D
                  New_Occurrence_Of (B, Loc))));   --  B

            --  Generate:
            --    Abort_Defer;

            Prepend_To (TaskE_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));

            --  Generate:
            --    Abort_Undefer;
            --    <abortable-statements>

            Cleanup_Stmts := New_Copy_List_Tree (Astats);

            Prepend_To
              (Cleanup_Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));

            --  Wrap the statements in a block. Exp_Ch7.Expand_Cleanup_Actions
            --  will generate a _clean for the additional status flag.

            --  Generate:
            --    declare
            --       procedure _clean is
            --       begin
            --          Cancel_Task_Entry_Call (U);
            --       end _clean;
            --    begin
            --       Cleanup_Stmts
            --    at end
            --       _clean;
            --    end;

            Cleanup_Block_Ent := Make_Temporary (Loc, 'C');
            Cleanup_Block :=
              Build_Cleanup_Block (Loc, Cleanup_Block_Ent, Cleanup_Stmts, T);

            --  Wrap the cleanup block in an exception handling block

            --  Generate:
            --    begin
            --       Cleanup_Block
            --    exception
            --       when Abort_Signal => Abort_Undefer;
            --    end;

            Abort_Block_Ent := Make_Temporary (Loc, 'A');

            Append_To (TaskE_Stmts,
              Make_Implicit_Label_Declaration (Loc,
                Defining_Identifier => Abort_Block_Ent));

            Append_To (TaskE_Stmts,
              Build_Abort_Block
                (Loc, Abort_Block_Ent, Cleanup_Block_Ent, Cleanup_Block));

            --  Generate:
            --    if not T then
            --       <triggering-statements>
            --    end if;

            Append_To (TaskE_Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Op_Not (Loc, Right_Opnd => New_Occurrence_Of (T, Loc)),

                Then_Statements =>
                  New_Copy_List_Tree (Tstats)));

            ----------------------------------
            -- Protected procedure handling --
            ----------------------------------

            --  Generate:
            --    <dispatching-call>;
            --    <triggering-statements>

            ProtP_Stmts := New_Copy_List_Tree (Tstats);
            Prepend_To (ProtP_Stmts, New_Copy_Tree (Ecall));

            --  Generate:
            --    S := Ada.Tags.Get_Offset_Index
            --           (Ada.Tags.Tag (<object>), DT_Position (Call_Ent));

            Conc_Typ_Stmts :=
              New_List (Build_S_Assignment (Loc, S, Obj, Call_Ent));

            --  Generate:
            --    _Disp_Get_Prim_Op_Kind (<object>, S, C);

            Append_To (Conc_Typ_Stmts,
              Make_Procedure_Call_Statement (Loc,
                Name =>
                  New_Occurrence_Of
                    (Find_Prim_Op (Etype (Etype (Obj)),
                                   Name_uDisp_Get_Prim_Op_Kind),
                     Loc),
                Parameter_Associations =>
                  New_List (
                    New_Copy_Tree (Obj),
                    New_Occurrence_Of (S, Loc),
                    New_Occurrence_Of (C, Loc))));

            --  Generate:
            --    if C = POK_Procedure_Entry then
            --       ProtE_Stmts
            --    elsif C = POK_Task_Entry then
            --       TaskE_Stmts
            --    else
            --       ProtP_Stmts
            --    end if;

            Append_To (Conc_Typ_Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Op_Eq (Loc,
                    Left_Opnd  =>
                      New_Occurrence_Of (C, Loc),
                    Right_Opnd =>
                      New_Occurrence_Of (RTE (RE_POK_Protected_Entry), Loc)),

                Then_Statements =>
                  ProtE_Stmts,

                Elsif_Parts =>
                  New_List (
                    Make_Elsif_Part (Loc,
                      Condition =>
                        Make_Op_Eq (Loc,
                          Left_Opnd  =>
                            New_Occurrence_Of (C, Loc),
                          Right_Opnd =>
                            New_Occurrence_Of (RTE (RE_POK_Task_Entry), Loc)),

                      Then_Statements =>
                        TaskE_Stmts)),

                Else_Statements =>
                  ProtP_Stmts));

            --  Generate:
            --    <dispatching-call>;
            --    <triggering-statements>

            Lim_Typ_Stmts := New_Copy_List_Tree (Tstats);
            Prepend_To (Lim_Typ_Stmts, New_Copy_Tree (Ecall));

            --  Generate:
            --    if K = Ada.Tags.TK_Limited_Tagged
            --         or else K = Ada.Tags.TK_Tagged
            --       then
            --       Lim_Typ_Stmts
            --    else
            --       Conc_Typ_Stmts
            --    end if;

            Append_To (Stmts,
              Make_Implicit_If_Statement (N,
                Condition       => Build_Dispatching_Tag_Check (K, N),
                Then_Statements => Lim_Typ_Stmts,
                Else_Statements => Conc_Typ_Stmts));

            Rewrite (N,
              Make_Block_Statement (Loc,
                Declarations =>
                  Decls,
                Handled_Statement_Sequence =>
                  Make_Handled_Sequence_Of_Statements (Loc, Stmts)));

            Analyze (N);
            return;

         --  Delay triggering statement processing

         else
            --  Add a Delay_Block object to the parameter list of the delay
            --  procedure to form the parameter list of the Wait entry call.

            Dblock_Ent := Make_Temporary (Loc, 'D');

            Pdef := Entity (Name (Ecall));

            if Is_RTE (Pdef, RO_CA_Delay_For) then
               Enqueue_Call :=
                 New_Occurrence_Of (RTE (RE_Enqueue_Duration), Loc);

            elsif Is_RTE (Pdef, RO_CA_Delay_Until) then
               Enqueue_Call :=
                 New_Occurrence_Of (RTE (RE_Enqueue_Calendar), Loc);

            else pragma Assert (Is_RTE (Pdef, RO_RT_Delay_Until));
               Enqueue_Call := New_Occurrence_Of (RTE (RE_Enqueue_RT), Loc);
            end if;

            Append_To (Parameter_Associations (Ecall),
              Make_Attribute_Reference (Loc,
                Prefix         => New_Occurrence_Of (Dblock_Ent, Loc),
                Attribute_Name => Name_Unchecked_Access));

            --  Create the inner block to protect the abortable part

            Hdle := New_List (Build_Abort_Block_Handler (Loc));

            Prepend_To (Astats, Build_Runtime_Call (Loc, RE_Abort_Undefer));

            Abortable_Block :=
              Make_Block_Statement (Loc,
                Identifier                 => New_Occurrence_Of (Blk_Ent, Loc),
                Handled_Statement_Sequence =>
                  Make_Handled_Sequence_Of_Statements (Loc,
                    Statements => Astats),
                Has_Created_Identifier     => True,
                Is_Asynchronous_Call_Block => True);

            --  Append call to if Enqueue (When, DB'Unchecked_Access) then

            Rewrite (Ecall,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Function_Call (Loc,
                    Name => Enqueue_Call,
                    Parameter_Associations => Parameter_Associations (Ecall)),
                Then_Statements =>
                  New_List (Make_Block_Statement (Loc,
                    Handled_Statement_Sequence =>
                      Make_Handled_Sequence_Of_Statements (Loc,
                        Statements => New_List (
                          Make_Implicit_Label_Declaration (Loc,
                            Defining_Identifier => Blk_Ent,
                            Label_Construct     => Abortable_Block),
                          Abortable_Block),
                        Exception_Handlers => Hdle)))));

            Stmts := New_List (Ecall);

            --  Construct statement sequence for new block

            Append_To (Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Function_Call (Loc,
                    Name => New_Occurrence_Of (
                      RTE (RE_Timed_Out), Loc),
                    Parameter_Associations => New_List (
                      Make_Attribute_Reference (Loc,
                        Prefix         => New_Occurrence_Of (Dblock_Ent, Loc),
                        Attribute_Name => Name_Unchecked_Access))),
                Then_Statements => Tstats));

            --  The result is the new block

            Set_Entry_Cancel_Parameter (Blk_Ent, Dblock_Ent);

            Rewrite (N,
              Make_Block_Statement (Loc,
                Declarations => New_List (
                  Make_Object_Declaration (Loc,
                    Defining_Identifier => Dblock_Ent,
                    Aliased_Present     => True,
                    Object_Definition   =>
                      New_Occurrence_Of (RTE (RE_Delay_Block), Loc))),

                Handled_Statement_Sequence =>
                  Make_Handled_Sequence_Of_Statements (Loc, Stmts)));

            Analyze (N);
            return;
         end if;

      else
         N_Orig := N;
      end if;

      Extract_Entry (Ecall, Concval, Ename, Index);
      Build_Simple_Entry_Call (Ecall, Concval, Ename, Index);

      Stmts := Statements (Handled_Statement_Sequence (Ecall));
      Decls := Declarations (Ecall);

      if Is_Protected_Type (Etype (Concval)) then

         --  Get the declarations of the block expanded from the entry call

         Decl := First (Decls);
         while Present (Decl)
           and then (Nkind (Decl) /= N_Object_Declaration
                      or else not Is_RTE (Etype (Object_Definition (Decl)),
                                          RE_Communication_Block))
         loop
            Next (Decl);
         end loop;

         pragma Assert (Present (Decl));
         Cancel_Param := Defining_Identifier (Decl);

         --  Change the mode of the Protected_Entry_Call call

         --  Protected_Entry_Call (
         --    Object => po._object'Access,
         --    E => <entry index>;
         --    Uninterpreted_Data => P'Address;
         --    Mode => Asynchronous_Call;
         --    Block => Bnn);

         --  Skip assignments to temporaries created for in-out parameters

         --  This makes unwarranted assumptions about the shape of the expanded
         --  tree for the call, and should be cleaned up ???

         Stmt := First (Stmts);
         while Nkind (Stmt) /= N_Procedure_Call_Statement loop
            Next (Stmt);
         end loop;

         Call := Stmt;

         Param := First (Parameter_Associations (Call));
         while Present (Param)
           and then not Is_RTE (Etype (Param), RE_Call_Modes)
         loop
            Next (Param);
         end loop;

         pragma Assert (Present (Param));
         Rewrite (Param, New_Occurrence_Of (RTE (RE_Asynchronous_Call), Loc));
         Analyze (Param);

         --  Append an if statement to execute the abortable part

         --  Generate:
         --    if Enqueued (Bnn) then

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition =>
               Make_Function_Call (Loc,
                 Name => New_Occurrence_Of (RTE (RE_Enqueued), Loc),
                 Parameter_Associations => New_List (
                   New_Occurrence_Of (Cancel_Param, Loc))),
             Then_Statements => Astats));

         Abortable_Block :=
           Make_Block_Statement (Loc,
             Identifier => New_Occurrence_Of (Blk_Ent, Loc),
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts),
             Has_Created_Identifier => True,
             Is_Asynchronous_Call_Block => True);

         --  Aborts are not deferred at beginning of exception handlers in
         --  ZCX mode.

         if ZCX_Exceptions then
            Handler_Stmt := Make_Null_Statement (Loc);

         else
            Handler_Stmt := Build_Runtime_Call (Loc, RE_Abort_Undefer);
         end if;

         Stmts := New_List (
           Make_Block_Statement (Loc,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => New_List (
                   Make_Implicit_Label_Declaration (Loc,
                     Defining_Identifier => Blk_Ent,
                     Label_Construct     => Abortable_Block),
                   Abortable_Block),

               --  exception

                 Exception_Handlers => New_List (
                   Make_Implicit_Exception_Handler (Loc,

               --  when Abort_Signal =>
               --     Abort_Undefer.all;

                     Exception_Choices =>
                       New_List (New_Occurrence_Of (Stand.Abort_Signal, Loc)),
                     Statements => New_List (Handler_Stmt))))),

         --  if not Cancelled (Bnn) then
         --     triggered statements
         --  end if;

           Make_Implicit_If_Statement (N,
             Condition => Make_Op_Not (Loc,
               Right_Opnd =>
                 Make_Function_Call (Loc,
                   Name => New_Occurrence_Of (RTE (RE_Cancelled), Loc),
                   Parameter_Associations => New_List (
                     New_Occurrence_Of (Cancel_Param, Loc)))),
             Then_Statements => Tstats));

      --  Asynchronous task entry call

      else
         if No (Decls) then
            Decls := New_List;
         end if;

         B := Make_Defining_Identifier (Loc, Name_uB);

         --  Insert declaration of B in declarations of existing block

         Prepend_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => B,
             Object_Definition   =>
               New_Occurrence_Of (Standard_Boolean, Loc)));

         Cancel_Param := Make_Defining_Identifier (Loc, Name_uC);

         --  Insert declaration of C in declarations of existing block

         Prepend_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => Cancel_Param,
             Object_Definition   =>
               New_Occurrence_Of (Standard_Boolean, Loc)));

         --  Remove and save the call to Call_Simple

         Stmt := First (Stmts);

         --  Skip assignments to temporaries created for in-out parameters.
         --  This makes unwarranted assumptions about the shape of the expanded
         --  tree for the call, and should be cleaned up ???

         while Nkind (Stmt) /= N_Procedure_Call_Statement loop
            Next (Stmt);
         end loop;

         Call := Stmt;

         --  Create the inner block to protect the abortable part

         Hdle := New_List (Build_Abort_Block_Handler (Loc));

         Prepend_To (Astats, Build_Runtime_Call (Loc, RE_Abort_Undefer));

         Abortable_Block :=
           Make_Block_Statement (Loc,
             Identifier                 => New_Occurrence_Of (Blk_Ent, Loc),
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Statements => Astats),
             Has_Created_Identifier     => True,
             Is_Asynchronous_Call_Block => True);

         Insert_After (Call,
           Make_Block_Statement (Loc,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => New_List (
                   Make_Implicit_Label_Declaration (Loc,
                     Defining_Identifier => Blk_Ent,
                     Label_Construct     => Abortable_Block),
                   Abortable_Block),
                 Exception_Handlers => Hdle)));

         --  Create new call statement

         Params := Parameter_Associations (Call);

         Append_To (Params,
           New_Occurrence_Of (RTE (RE_Asynchronous_Call), Loc));
         Append_To (Params, New_Occurrence_Of (B, Loc));

         Rewrite (Call,
           Make_Procedure_Call_Statement (Loc,
             Name => New_Occurrence_Of (RTE (RE_Task_Entry_Call), Loc),
             Parameter_Associations => Params));

         --  Construct statement sequence for new block

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition =>
               Make_Op_Not (Loc, New_Occurrence_Of (Cancel_Param, Loc)),
             Then_Statements => Tstats));

         --  Protected the call against abort

         Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
      end if;

      Set_Entry_Cancel_Parameter (Blk_Ent, Cancel_Param);

      --  The result is the new block

      Rewrite (N_Orig,
        Make_Block_Statement (Loc,
          Declarations => Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc, Stmts)));

      Analyze (N_Orig);
   end Expand_N_Asynchronous_Select;

   -------------------------------------
   -- Expand_N_Conditional_Entry_Call --
   -------------------------------------

   --  The conditional task entry call is converted to a call to
   --  Task_Entry_Call:

   --    declare
   --       B : Boolean;
   --       P : parms := (parm, parm, parm);

   --    begin
   --       Task_Entry_Call
   --         (<acceptor-task>,   --  Acceptor
   --          <entry-index>,     --  E
   --          P'Address,         --  Uninterpreted_Data
   --          Conditional_Call,  --  Mode
   --          B);                --  Rendezvous_Successful
   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --       if B then
   --          normal-statements
   --       else
   --          else-statements
   --       end if;
   --    end;

   --  For a description of the use of P and the assignments after the call,
   --  see Expand_N_Entry_Call_Statement. Note that the entry call of the
   --  conditional entry call has already been expanded (by the Expand_N_Entry
   --  _Call_Statement procedure) as follows:

   --    declare
   --       P : parms := (parm, parm, parm);
   --    begin
   --       ... info for in-out parameters
   --       Call_Simple (acceptor-task, entry-index, P'Address);
   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --    end;

   --  so the task at hand is to convert the latter expansion into the former

   --  The conditional protected entry call is converted to a call to
   --  Protected_Entry_Call:

   --    declare
   --       P : parms := (parm, parm, parm);
   --       Bnn : Communications_Block;

   --    begin
   --       Protected_Entry_Call
   --         (po._object'Access,  --  Object
   --          <entry index>,      --  E
   --          P'Address,          --  Uninterpreted_Data
   --          Conditional_Call,   --  Mode
   --          Bnn);               --  Block
   --       parm := P.param;
   --       parm := P.param;
   --       ...
   --       if Cancelled (Bnn) then
   --          else-statements
   --       else
   --          normal-statements
   --       end if;
   --    end;

   --  Ada 2005 (AI-345): A dispatching conditional entry call is converted
   --  into:

   --    declare
   --       B : Boolean := False;
   --       C : Ada.Tags.Prim_Op_Kind;
   --       K : Ada.Tags.Tagged_Kind :=
   --             Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag (<object>));
   --       P : Parameters := (Param1 .. ParamN);
   --       S : Integer;

   --    begin
   --       if K = Ada.Tags.TK_Limited_Tagged
   --         or else K = Ada.Tags.TK_Tagged
   --       then
   --          <dispatching-call>;
   --          <triggering-statements>

   --       else
   --          S :=
   --            Ada.Tags.Get_Offset_Index
   --              (Ada.Tags.Tag (<object>), DT_Position (<dispatching-call>));

   --          _Disp_Conditional_Select (<object>, S, P'Address, C, B);

   --          if C = POK_Protected_Entry
   --            or else C = POK_Task_Entry
   --          then
   --             Param1 := P.Param1;
   --             ...
   --             ParamN := P.ParamN;
   --          end if;

   --          if B then
   --             if C = POK_Procedure
   --               or else C = POK_Protected_Procedure
   --               or else C = POK_Task_Procedure
   --             then
   --                <dispatching-call>;
   --             end if;

   --             <triggering-statements>
   --          else
   --             <else-statements>
   --          end if;
   --       end if;
   --    end;

   procedure Expand_N_Conditional_Entry_Call (N : Node_Id) is
      Loc : constant Source_Ptr := Sloc (N);
      Alt : constant Node_Id    := Entry_Call_Alternative (N);
      Blk : Node_Id             := Entry_Call_Statement (Alt);

      Actuals        : List_Id;
      Blk_Typ        : Entity_Id;
      Call           : Node_Id;
      Call_Ent       : Entity_Id;
      Conc_Typ_Stmts : List_Id;
      Decl           : Node_Id;
      Decls          : List_Id;
      Formals        : List_Id;
      Lim_Typ_Stmts  : List_Id;
      N_Stats        : List_Id;
      Obj            : Entity_Id;
      Param          : Node_Id;
      Params         : List_Id;
      Stmt           : Node_Id;
      Stmts          : List_Id;
      Transient_Blk  : Node_Id;
      Unpack         : List_Id;

      B : Entity_Id;  --  Call status flag
      C : Entity_Id;  --  Call kind
      K : Entity_Id;  --  Tagged kind
      P : Entity_Id;  --  Parameter block
      S : Entity_Id;  --  Primitive operation slot

   begin
      Process_Statements_For_Controlled_Objects (N);

      if Ada_Version >= Ada_2005
        and then Nkind (Blk) = N_Procedure_Call_Statement
      then
         Extract_Dispatching_Call (Blk, Call_Ent, Obj, Actuals, Formals);

         Decls := New_List;
         Stmts := New_List;

         --  Call status flag processing, generate:
         --    B : Boolean := False;

         B := Build_B (Loc, Decls);

         --  Call kind processing, generate:
         --    C : Ada.Tags.Prim_Op_Kind;

         C := Build_C (Loc, Decls);

         --  Tagged kind processing, generate:
         --    K : Ada.Tags.Tagged_Kind :=
         --          Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag (<object>));

         K := Build_K (Loc, Decls, Obj);

         --  Parameter block processing

         Blk_Typ := Build_Parameter_Block (Loc, Actuals, Formals, Decls);
         P       := Parameter_Block_Pack
                      (Loc, Blk_Typ, Actuals, Formals, Decls, Stmts);

         --  Dispatch table slot processing, generate:
         --    S : Integer;

         S := Build_S (Loc, Decls);

         --  Generate:
         --    S := Ada.Tags.Get_Offset_Index
         --           (Ada.Tags.Tag (<object>), DT_Position (Call_Ent));

         Conc_Typ_Stmts :=
           New_List (Build_S_Assignment (Loc, S, Obj, Call_Ent));

         --  Generate:
         --    _Disp_Conditional_Select (<object>, S, P'Address, C, B);

         Append_To (Conc_Typ_Stmts,
           Make_Procedure_Call_Statement (Loc,
             Name =>
               New_Occurrence_Of (
                 Find_Prim_Op (Etype (Etype (Obj)),
                   Name_uDisp_Conditional_Select),
                 Loc),
             Parameter_Associations =>
               New_List (
                 New_Copy_Tree (Obj),            --  <object>
                 New_Occurrence_Of (S, Loc),      --  S
                 Make_Attribute_Reference (Loc,  --  P'Address
                   Prefix         => New_Occurrence_Of (P, Loc),
                   Attribute_Name => Name_Address),
                 New_Occurrence_Of (C, Loc),      --  C
                 New_Occurrence_Of (B, Loc))));   --  B

         --  Generate:
         --    if C = POK_Protected_Entry
         --      or else C = POK_Task_Entry
         --    then
         --       Param1 := P.Param1;
         --       ...
         --       ParamN := P.ParamN;
         --    end if;

         Unpack := Parameter_Block_Unpack (Loc, P, Actuals, Formals);

         --  Generate the if statement only when the packed parameters need
         --  explicit assignments to their corresponding actuals.

         if Present (Unpack) then
            Append_To (Conc_Typ_Stmts,
              Make_Implicit_If_Statement (N,
                Condition =>
                  Make_Or_Else (Loc,
                    Left_Opnd =>
                      Make_Op_Eq (Loc,
                        Left_Opnd =>
                          New_Occurrence_Of (C, Loc),
                        Right_Opnd =>
                          New_Occurrence_Of (RTE (
                            RE_POK_Protected_Entry), Loc)),

                    Right_Opnd =>
                      Make_Op_Eq (Loc,
                        Left_Opnd =>
                          New_Occurrence_Of (C, Loc),
                        Right_Opnd =>
                          New_Occurrence_Of (RTE (RE_POK_Task_Entry), Loc))),

                Then_Statements => Unpack));
         end if;

         --  Generate:
         --    if B then
         --       if C = POK_Procedure
         --         or else C = POK_Protected_Procedure
         --         or else C = POK_Task_Procedure
         --       then
         --          <dispatching-call>
         --       end if;
         --       <normal-statements>
         --    else
         --       <else-statements>
         --    end if;

         N_Stats := New_Copy_List_Tree (Statements (Alt));

         Prepend_To (N_Stats,
           Make_Implicit_If_Statement (N,
             Condition =>
               Make_Or_Else (Loc,
                 Left_Opnd =>
                   Make_Op_Eq (Loc,
                     Left_Opnd =>
                       New_Occurrence_Of (C, Loc),
                     Right_Opnd =>
                       New_Occurrence_Of (RTE (RE_POK_Procedure), Loc)),

                 Right_Opnd =>
                   Make_Or_Else (Loc,
                     Left_Opnd =>
                       Make_Op_Eq (Loc,
                         Left_Opnd =>
                           New_Occurrence_Of (C, Loc),
                         Right_Opnd =>
                           New_Occurrence_Of (RTE (
                             RE_POK_Protected_Procedure), Loc)),

                     Right_Opnd =>
                       Make_Op_Eq (Loc,
                         Left_Opnd =>
                           New_Occurrence_Of (C, Loc),
                         Right_Opnd =>
                           New_Occurrence_Of (RTE (
                             RE_POK_Task_Procedure), Loc)))),

             Then_Statements =>
               New_List (Blk)));

         Append_To (Conc_Typ_Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => New_Occurrence_Of (B, Loc),
             Then_Statements => N_Stats,
             Else_Statements => Else_Statements (N)));

         --  Generate:
         --    <dispatching-call>;
         --    <triggering-statements>

         Lim_Typ_Stmts := New_Copy_List_Tree (Statements (Alt));
         Prepend_To (Lim_Typ_Stmts, New_Copy_Tree (Blk));

         --  Generate:
         --    if K = Ada.Tags.TK_Limited_Tagged
         --         or else K = Ada.Tags.TK_Tagged
         --       then
         --       Lim_Typ_Stmts
         --    else
         --       Conc_Typ_Stmts
         --    end if;

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => Build_Dispatching_Tag_Check (K, N),
             Then_Statements => Lim_Typ_Stmts,
             Else_Statements => Conc_Typ_Stmts));

         Rewrite (N,
           Make_Block_Statement (Loc,
             Declarations =>
               Decls,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Stmts)));

      --  As described above, the entry alternative is transformed into a
      --  block that contains the gnulli call, and possibly assignment
      --  statements for in-out parameters. The gnulli call may itself be
      --  rewritten into a transient block if some unconstrained parameters
      --  require it. We need to retrieve the call to complete its parameter
      --  list.

      else
         Transient_Blk :=
           First_Real_Statement (Handled_Statement_Sequence (Blk));

         if Present (Transient_Blk)
           and then Nkind (Transient_Blk) = N_Block_Statement
         then
            Blk := Transient_Blk;
         end if;

         Stmts := Statements (Handled_Statement_Sequence (Blk));
         Stmt  := First (Stmts);
         while Nkind (Stmt) /= N_Procedure_Call_Statement loop
            Next (Stmt);
         end loop;

         Call   := Stmt;
         Params := Parameter_Associations (Call);

         if Is_RTE (Entity (Name (Call)), RE_Protected_Entry_Call) then

            --  Substitute Conditional_Entry_Call for Simple_Call parameter

            Param := First (Params);
            while Present (Param)
              and then not Is_RTE (Etype (Param), RE_Call_Modes)
            loop
               Next (Param);
            end loop;

            pragma Assert (Present (Param));
            Rewrite (Param,
              New_Occurrence_Of (RTE (RE_Conditional_Call), Loc));

            Analyze (Param);

            --  Find the Communication_Block parameter for the call to the
            --  Cancelled function.

            Decl := First (Declarations (Blk));
            while Present (Decl)
              and then not Is_RTE (Etype (Object_Definition (Decl)),
                             RE_Communication_Block)
            loop
               Next (Decl);
            end loop;

            --  Add an if statement to execute the else part if the call
            --  does not succeed (as indicated by the Cancelled predicate).

            Append_To (Stmts,
              Make_Implicit_If_Statement (N,
                Condition => Make_Function_Call (Loc,
                  Name => New_Occurrence_Of (RTE (RE_Cancelled), Loc),
                  Parameter_Associations => New_List (
                    New_Occurrence_Of (Defining_Identifier (Decl), Loc))),
                Then_Statements => Else_Statements (N),
                Else_Statements => Statements (Alt)));

         else
            B := Make_Defining_Identifier (Loc, Name_uB);

            --  Insert declaration of B in declarations of existing block

            if No (Declarations (Blk)) then
               Set_Declarations (Blk, New_List);
            end if;

            Prepend_To (Declarations (Blk),
              Make_Object_Declaration (Loc,
                Defining_Identifier => B,
                Object_Definition   =>
                  New_Occurrence_Of (Standard_Boolean, Loc)));

            --  Create new call statement

            Append_To (Params,
              New_Occurrence_Of (RTE (RE_Conditional_Call), Loc));
            Append_To (Params, New_Occurrence_Of (B, Loc));

            Rewrite (Call,
              Make_Procedure_Call_Statement (Loc,
                Name => New_Occurrence_Of (RTE (RE_Task_Entry_Call), Loc),
                Parameter_Associations => Params));

            --  Construct statement sequence for new block

            Append_To (Stmts,
              Make_Implicit_If_Statement (N,
                Condition       => New_Occurrence_Of (B, Loc),
                Then_Statements => Statements (Alt),
                Else_Statements => Else_Statements (N)));
         end if;

         --  The result is the new block

         Rewrite (N,
           Make_Block_Statement (Loc,
             Declarations => Declarations (Blk),
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
      end if;

      Analyze (N);
   end Expand_N_Conditional_Entry_Call;

   ---------------------------------------
   -- Expand_N_Delay_Relative_Statement --
   ---------------------------------------

   --  Delay statement is implemented as a procedure call to Delay_For
   --  defined in Ada.Calendar.Delays in order to reduce the overhead of
   --  simple delays imposed by the use of Protected Objects.

   procedure Expand_N_Delay_Relative_Statement (N : Node_Id) is
      Loc  : constant Source_Ptr := Sloc (N);
      Proc : Entity_Id;

   begin
      --  Try to use System.Relative_Delays.Delay_For only if available. This
      --  is the implementation used on restricted platforms when Ada.Calendar
      --  is not available.

      if RTE_Available (RO_RD_Delay_For) then
         Proc := RTE (RO_RD_Delay_For);

      --  Otherwise, use Ada.Calendar.Delays.Delay_For and emit an error
      --  message if not available.

      else
         Proc := RTE (RO_CA_Delay_For);
      end if;

      Rewrite (N,
        Make_Procedure_Call_Statement (Loc,
          Name                   => New_Occurrence_Of (Proc, Loc),
          Parameter_Associations => New_List (Expression (N))));
      Analyze (N);
   end Expand_N_Delay_Relative_Statement;

   ------------------------------------
   -- Expand_N_Delay_Until_Statement --
   ------------------------------------

   --  Delay Until statement is implemented as a procedure call to
   --  Delay_Until defined in Ada.Calendar.Delays and Ada.Real_Time.Delays.

   procedure Expand_N_Delay_Until_Statement (N : Node_Id) is
      Loc : constant Source_Ptr := Sloc (N);
      Typ : Entity_Id;

   begin
      if Is_RTE (Base_Type (Etype (Expression (N))), RO_CA_Time) then
         Typ := RTE (RO_CA_Delay_Until);
      else
         Typ := RTE (RO_RT_Delay_Until);
      end if;

      Rewrite (N,
        Make_Procedure_Call_Statement (Loc,
          Name => New_Occurrence_Of (Typ, Loc),
          Parameter_Associations => New_List (Expression (N))));

      Analyze (N);
   end Expand_N_Delay_Until_Statement;

   -------------------------
   -- Expand_N_Entry_Body --
   -------------------------

   procedure Expand_N_Entry_Body (N : Node_Id) is
   begin
      --  Associate discriminals with the next protected operation body to be
      --  expanded.

      if Present (Next_Protected_Operation (N)) then
         Set_Discriminals (Parent (Current_Scope));
      end if;
   end Expand_N_Entry_Body;

   -----------------------------------
   -- Expand_N_Entry_Call_Statement --
   -----------------------------------

   --  An entry call is expanded into GNARLI calls to implement a simple entry
   --  call (see Build_Simple_Entry_Call).

   procedure Expand_N_Entry_Call_Statement (N : Node_Id) is
      Concval : Node_Id;
      Ename   : Node_Id;
      Index   : Node_Id;

   begin
      if No_Run_Time_Mode then
         Error_Msg_CRT ("entry call", N);
         return;
      end if;

      --  If this entry call is part of an asynchronous select, don't expand it
      --  here; it will be expanded with the select statement. Don't expand
      --  timed entry calls either, as they are translated into asynchronous
      --  entry calls.

      --  ??? This whole approach is questionable; it may be better to go back
      --  to allowing the expansion to take place and then attempting to fix it
      --  up in Expand_N_Asynchronous_Select. The tricky part is figuring out
      --  whether the expanded call is on a task or protected entry.

      if (Nkind (Parent (N)) /= N_Triggering_Alternative
           or else N /= Triggering_Statement (Parent (N)))
        and then (Nkind (Parent (N)) /= N_Entry_Call_Alternative
                   or else N /= Entry_Call_Statement (Parent (N))
                   or else Nkind (Parent (Parent (N))) /= N_Timed_Entry_Call)
      then
         Extract_Entry (N, Concval, Ename, Index);
         Build_Simple_Entry_Call (N, Concval, Ename, Index);
      end if;
   end Expand_N_Entry_Call_Statement;

   --------------------------------
   -- Expand_N_Entry_Declaration --
   --------------------------------

   --  If there are parameters, then first, each of the formals is marked by
   --  setting Is_Entry_Formal. Next a record type is built which is used to
   --  hold the parameter values. The name of this record type is entryP where
   --  entry is the name of the entry, with an additional corresponding access
   --  type called entryPA. The record type has matching components for each
   --  formal (the component names are the same as the formal names). For
   --  elementary types, the component type matches the formal type. For
   --  composite types, an access type is declared (with the name formalA)
   --  which designates the formal type, and the type of the component is this
   --  access type. Finally the Entry_Component of each formal is set to
   --  reference the corresponding record component.

   procedure Expand_N_Entry_Declaration (N : Node_Id) is
      Loc        : constant Source_Ptr := Sloc (N);
      Entry_Ent  : constant Entity_Id  := Defining_Identifier (N);
      Components : List_Id;
      Formal     : Node_Id;
      Ftype      : Entity_Id;
      Last_Decl  : Node_Id;
      Component  : Entity_Id;
      Ctype      : Entity_Id;
      Decl       : Node_Id;
      Rec_Ent    : Entity_Id;
      Acc_Ent    : Entity_Id;

   begin
      Formal := First_Formal (Entry_Ent);
      Last_Decl := N;

      --  Most processing is done only if parameters are present

      if Present (Formal) then
         Components := New_List;

         --  Loop through formals

         while Present (Formal) loop
            Set_Is_Entry_Formal (Formal);
            Component :=
              Make_Defining_Identifier (Sloc (Formal), Chars (Formal));
            Set_Entry_Component (Formal, Component);
            Set_Entry_Formal (Component, Formal);
            Ftype := Etype (Formal);

            --  Declare new access type and then append

            Ctype := Make_Temporary (Loc, 'A');
            Set_Is_Param_Block_Component_Type (Ctype);

            Decl :=
              Make_Full_Type_Declaration (Loc,
                Defining_Identifier => Ctype,
                Type_Definition     =>
                  Make_Access_To_Object_Definition (Loc,
                    All_Present        => True,
                    Constant_Present   => Ekind (Formal) = E_In_Parameter,
                    Subtype_Indication => New_Occurrence_Of (Ftype, Loc)));

            Insert_After (Last_Decl, Decl);
            Last_Decl := Decl;

            Append_To (Components,
              Make_Component_Declaration (Loc,
                Defining_Identifier => Component,
                Component_Definition =>
                  Make_Component_Definition (Loc,
                    Aliased_Present    => False,
                    Subtype_Indication => New_Occurrence_Of (Ctype, Loc))));

            Next_Formal_With_Extras (Formal);
         end loop;

         --  Create the Entry_Parameter_Record declaration

         Rec_Ent := Make_Temporary (Loc, 'P');

         Decl :=
           Make_Full_Type_Declaration (Loc,
             Defining_Identifier => Rec_Ent,
             Type_Definition     =>
               Make_Record_Definition (Loc,
                 Component_List =>
                   Make_Component_List (Loc,
                     Component_Items => Components)));

         Insert_After (Last_Decl, Decl);
         Last_Decl := Decl;

         --  Construct and link in the corresponding access type

         Acc_Ent := Make_Temporary (Loc, 'A');

         Set_Entry_Parameters_Type (Entry_Ent, Acc_Ent);

         Decl :=
           Make_Full_Type_Declaration (Loc,
             Defining_Identifier => Acc_Ent,
             Type_Definition     =>
               Make_Access_To_Object_Definition (Loc,
                 All_Present        => True,
                 Subtype_Indication => New_Occurrence_Of (Rec_Ent, Loc)));

         Insert_After (Last_Decl, Decl);
      end if;
   end Expand_N_Entry_Declaration;

   -----------------------------
   -- Expand_N_Protected_Body --
   -----------------------------

   --  Protected bodies are expanded to the completion of the subprograms
   --  created for the corresponding protected type. These are a protected and
   --  unprotected version of each protected subprogram in the object, a
   --  function to calculate each entry barrier, and a procedure to execute the
   --  sequence of statements of each protected entry body. For example, for
   --  protected type ptype:

   --  function entB
   --    (O : System.Address;
   --     E : Protected_Entry_Index)
   --     return Boolean
   --  is
   --     <discriminant renamings>
   --     <private object renamings>
   --  begin
   --     return <barrier expression>;
   --  end entB;

   --  procedure pprocN (_object : in out poV;...) is
   --     <discriminant renamings>
   --     <private object renamings>
   --  begin
   --     <sequence of statements>
   --  end pprocN;

   --  procedure pprocP (_object : in out poV;...) is
   --     procedure _clean is
   --       Pn : Boolean;
   --     begin
   --       ptypeS (_object, Pn);
   --       Unlock (_object._object'Access);
   --       Abort_Undefer.all;
   --     end _clean;

   --  begin
   --     Abort_Defer.all;
   --     Lock (_object._object'Access);
   --     pprocN (_object;...);
   --  at end
   --     _clean;
   --  end pproc;

   --  function pfuncN (_object : poV;...) return Return_Type is
   --     <discriminant renamings>
   --     <private object renamings>
   --  begin
   --     <sequence of statements>
   --  end pfuncN;

   --  function pfuncP (_object : poV) return Return_Type is
   --     procedure _clean is
   --     begin
   --        Unlock (_object._object'Access);
   --        Abort_Undefer.all;
   --     end _clean;

   --  begin
   --     Abort_Defer.all;
   --     Lock (_object._object'Access);
   --     return pfuncN (_object);

   --  at end
   --     _clean;
   --  end pfunc;

   --  procedure entE
   --    (O : System.Address;
   --     P : System.Address;
   --     E : Protected_Entry_Index)
   --  is
   --     <discriminant renamings>
   --     <private object renamings>
   --     type poVP is access poV;
   --     _Object : ptVP := ptVP!(O);

   --  begin
   --     begin
   --        <statement sequence>
   --        Complete_Entry_Body (_Object._Object);
   --     exception
   --        when all others =>
   --           Exceptional_Complete_Entry_Body (
   --             _Object._Object, Get_GNAT_Exception);
   --     end;
   --  end entE;

   --  The type poV is the record created for the protected type to hold
   --  the state of the protected object.

   procedure Expand_N_Protected_Body (N : Node_Id) is
      Loc : constant Source_Ptr := Sloc (N);
      Pid : constant Entity_Id  := Corresponding_Spec (N);

      Lock_Free_Active : constant Boolean := Uses_Lock_Free (Pid);
      --  This flag indicates whether the lock free implementation is active

      Current_Node : Node_Id;
      Disp_Op_Body : Node_Id;
      New_Op_Body  : Node_Id;
      Op_Body      : Node_Id;
      Op_Id        : Entity_Id;

      function Build_Dispatching_Subprogram_Body
        (N        : Node_Id;
         Pid      : Node_Id;
         Prot_Bod : Node_Id) return Node_Id;
      --  Build a dispatching version of the protected subprogram body. The
      --  newly generated subprogram contains a call to the original protected
      --  body. The following code is generated:
      --
      --  function <protected-function-name> (Param1 .. ParamN) return
      --    <return-type> is
      --  begin
      --     return <protected-function-name>P (Param1 .. ParamN);
      --  end <protected-function-name>;
      --
      --  or
      --
      --  procedure <protected-procedure-name> (Param1 .. ParamN) is
      --  begin
      --     <protected-procedure-name>P (Param1 .. ParamN);
      --  end <protected-procedure-name>

      ---------------------------------------
      -- Build_Dispatching_Subprogram_Body --
      ---------------------------------------

      function Build_Dispatching_Subprogram_Body
        (N        : Node_Id;
         Pid      : Node_Id;
         Prot_Bod : Node_Id) return Node_Id
      is
         Loc     : constant Source_Ptr := Sloc (N);
         Actuals : List_Id;
         Formal  : Node_Id;
         Spec    : Node_Id;
         Stmts   : List_Id;

      begin
         --  Generate a specification without a letter suffix in order to
         --  override an interface function or procedure.

         Spec := Build_Protected_Sub_Specification (N, Pid, Dispatching_Mode);

         --  The formal parameters become the actuals of the protected function
         --  or procedure call.

         Actuals := New_List;
         Formal  := First (Parameter_Specifications (Spec));
         while Present (Formal) loop
            Append_To (Actuals,
              Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
            Next (Formal);
         end loop;

         if Nkind (Spec) = N_Procedure_Specification then
            Stmts :=
              New_List (
                Make_Procedure_Call_Statement (Loc,
                  Name =>
                    New_Occurrence_Of (Corresponding_Spec (Prot_Bod), Loc),
                  Parameter_Associations => Actuals));

         else
            pragma Assert (Nkind (Spec) = N_Function_Specification);

            Stmts :=
              New_List (
                Make_Simple_Return_Statement (Loc,
                  Expression =>
                    Make_Function_Call (Loc,
                      Name =>
                        New_Occurrence_Of (Corresponding_Spec (Prot_Bod), Loc),
                      Parameter_Associations => Actuals)));
         end if;

         return
           Make_Subprogram_Body (Loc,
             Declarations               => Empty_List,
             Specification              => Spec,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc, Stmts));
      end Build_Dispatching_Subprogram_Body;

   --  Start of processing for Expand_N_Protected_Body

   begin
      if No_Run_Time_Mode then
         Error_Msg_CRT ("protected body", N);
         return;
      end if;

      --  This is the proper body corresponding to a stub. The declarations
      --  must be inserted at the point of the stub, which in turn is in the
      --  declarative part of the parent unit.

      if Nkind (Parent (N)) = N_Subunit then
         Current_Node := Corresponding_Stub (Parent (N));
      else
         Current_Node := N;
      end if;

      Op_Body := First (Declarations (N));

      --  The protected body is replaced with the bodies of its
      --  protected operations, and the declarations for internal objects
      --  that may have been created for entry family bounds.

      Rewrite (N, Make_Null_Statement (Sloc (N)));
      Analyze (N);

      while Present (Op_Body) loop
         case Nkind (Op_Body) is
            when N_Subprogram_Declaration =>
               null;

            when N_Subprogram_Body =>

               --  Do not create bodies for eliminated operations

               if not Is_Eliminated (Defining_Entity (Op_Body))
                 and then not Is_Eliminated (Corresponding_Spec (Op_Body))
               then
                  if Lock_Free_Active then
                     New_Op_Body :=
                       Build_Lock_Free_Unprotected_Subprogram_Body
                         (Op_Body, Pid);
                  else
                     New_Op_Body :=
                       Build_Unprotected_Subprogram_Body (Op_Body, Pid);
                  end if;

                  Insert_After (Current_Node, New_Op_Body);
                  Current_Node := New_Op_Body;
                  Analyze (New_Op_Body);

                  --  Build the corresponding protected operation. It may
                  --  appear that this is needed only if this is a visible
                  --  operation of the type, or if it is an interrupt handler,
                  --  and this was the strategy used previously in GNAT.

                  --  However, the operation may be exported through a 'Access
                  --  to an external caller. This is the common idiom in code
                  --  that uses the Ada 2005 Timing_Events package. As a result
                  --  we need to produce the protected body for both visible
                  --  and private operations, as well as operations that only
                  --  have a body in the source, and for which we create a
                  --  declaration in the protected body itself.

                  if Present (Corresponding_Spec (Op_Body)) then
                     if Lock_Free_Active then
                        New_Op_Body :=
                          Build_Lock_Free_Protected_Subprogram_Body
                            (Op_Body, Pid, Specification (New_Op_Body));
                     else
                        New_Op_Body :=
                          Build_Protected_Subprogram_Body
                            (Op_Body, Pid, Specification (New_Op_Body));
                     end if;

                     Insert_After (Current_Node, New_Op_Body);
                     Analyze (New_Op_Body);

                     Current_Node := New_Op_Body;

                     --  Generate an overriding primitive operation body for
                     --  this subprogram if the protected type implements an
                     --  interface.

                     if Ada_Version >= Ada_2005
                       and then
                         Present (Interfaces (Corresponding_Record_Type (Pid)))
                     then
                        Disp_Op_Body :=
                          Build_Dispatching_Subprogram_Body
                            (Op_Body, Pid, New_Op_Body);

                        Insert_After (Current_Node, Disp_Op_Body);
                        Analyze (Disp_Op_Body);

                        Current_Node := Disp_Op_Body;
                     end if;
                  end if;
               end if;

            when N_Entry_Body =>
               Op_Id := Defining_Identifier (Op_Body);
               New_Op_Body := Build_Protected_Entry (Op_Body, Op_Id, Pid);

               Insert_After (Current_Node, New_Op_Body);
               Current_Node := New_Op_Body;
               Analyze (New_Op_Body);

            when N_Implicit_Label_Declaration =>
               null;

            when N_Itype_Reference =>
               Insert_After (Current_Node, New_Copy (Op_Body));

            when N_Freeze_Entity =>
               New_Op_Body := New_Copy (Op_Body);

               if Present (Entity (Op_Body))
                 and then Freeze_Node (Entity (Op_Body)) = Op_Body
               then
                  Set_Freeze_Node (Entity (Op_Body), New_Op_Body);
               end if;

               Insert_After (Current_Node, New_Op_Body);
               Current_Node := New_Op_Body;
               Analyze (New_Op_Body);

            when N_Pragma =>
               New_Op_Body := New_Copy (Op_Body);
               Insert_After (Current_Node, New_Op_Body);
               Current_Node := New_Op_Body;
               Analyze (New_Op_Body);

            when N_Object_Declaration =>
               pragma Assert (not Comes_From_Source (Op_Body));
               New_Op_Body := New_Copy (Op_Body);
               Insert_After (Current_Node, New_Op_Body);
               Current_Node := New_Op_Body;
               Analyze (New_Op_Body);

            when others =>
               raise Program_Error;

         end case;

         Next (Op_Body);
      end loop;

      --  Finally, create the body of the function that maps an entry index
      --  into the corresponding body index, except when there is no entry, or
      --  in a Ravenscar-like profile.

      if Corresponding_Runtime_Package (Pid) =
           System_Tasking_Protected_Objects_Entries
      then
         New_Op_Body := Build_Find_Body_Index (Pid);
         Insert_After (Current_Node, New_Op_Body);
         Current_Node := New_Op_Body;
         Analyze (New_Op_Body);
      end if;

      --  Ada 2005 (AI-345): Construct the primitive wrapper bodies after the
      --  protected body. At this point all wrapper specs have been created,
      --  frozen and included in the dispatch table for the protected type.

      if Ada_Version >= Ada_2005 then
         Build_Wrapper_Bodies (Loc, Pid, Current_Node);
      end if;
   end Expand_N_Protected_Body;

   -----------------------------------------
   -- Expand_N_Protected_Type_Declaration --
   -----------------------------------------

   --  First we create a corresponding record type declaration used to
   --  represent values of this protected type.
   --  The general form of this type declaration is

   --    type poV (discriminants) is record
   --      _Object       : aliased <kind>Protection
   --         [(<entry count> [, <handler count>])];
   --      [entry_family  : array (bounds) of Void;]
   --      <private data fields>
   --    end record;

   --  The discriminants are present only if the corresponding protected type
   --  has discriminants, and they exactly mirror the protected type
   --  discriminants. The private data fields similarly mirror the private
   --  declarations of the protected type.

   --  The Object field is always present. It contains RTS specific data used
   --  to control the protected object. It is declared as Aliased so that it
   --  can be passed as a pointer to the RTS. This allows the protected record
   --  to be referenced within RTS data structures. An appropriate Protection
   --  type and discriminant are generated.

   --  The Service field is present for protected objects with entries. It
   --  contains sufficient information to allow the entry service procedure for
   --  this object to be called when the object is not known till runtime.

   --  One entry_family component is present for each entry family in the
   --  task definition (see Expand_N_Task_Type_Declaration).

   --  When a protected object is declared, an instance of the protected type
   --  value record is created. The elaboration of this declaration creates the
   --  correct bounds for the entry families, and also evaluates the priority
   --  expression if needed. The initialization routine for the protected type
   --  itself then calls Initialize_Protection with appropriate parameters to
   --  initialize the value of the Task_Id field. Install_Handlers may be also
   --  called if a pragma Attach_Handler applies.

   --  Note: this record is passed to the subprograms created by the expansion
   --  of protected subprograms and entries. It is an in parameter to protected
   --  functions and an in out parameter to procedures and entry bodies. The
   --  Entity_Id for this created record type is placed in the
   --  Corresponding_Record_Type field of the associated protected type entity.

   --  Next we create a procedure specifications for protected subprograms and
   --  entry bodies. For each protected subprograms two subprograms are
   --  created, an unprotected and a protected version. The unprotected version
   --  is called from within other operations of the same protected object.

   --  We also build the call to register the procedure if a pragma
   --  Interrupt_Handler applies.

   --  A single subprogram is created to service all entry bodies; it has an
   --  additional boolean out parameter indicating that the previous entry call
   --  made by the current task was serviced immediately, i.e. not by proxy.
   --  The O parameter contains a pointer to a record object of the type
   --  described above. An untyped interface is used here to allow this
   --  procedure to be called in places where the type of the object to be
   --  serviced is not known. This must be done, for example, when a call that
   --  may have been requeued is cancelled; the corresponding object must be
   --  serviced, but which object that is not known till runtime.

   --  procedure ptypeS
   --    (O : System.Address; P : out Boolean);
   --  procedure pprocN (_object : in out poV);
   --  procedure pproc (_object : in out poV);
   --  function pfuncN (_object : poV);
   --  function pfunc (_object : poV);
   --  ...

   --  Note that this must come after the record type declaration, since
   --  the specs refer to this type.

   procedure Expand_N_Protected_Type_Declaration (N : Node_Id) is
      Discr_Map : constant Elist_Id   := New_Elmt_List;
      Loc       : constant Source_Ptr := Sloc (N);
      Prot_Typ  : constant Entity_Id  := Defining_Identifier (N);

      Lock_Free_Active : constant Boolean := Uses_Lock_Free (Prot_Typ);
      --  This flag indicates whether the lock free implementation is active

      Pdef : constant Node_Id := Protected_Definition (N);
      --  This contains two lists; one for visible and one for private decls

      Current_Node : Node_Id := N;
      E_Count      : Int;
      Entries_Aggr : Node_Id;

      procedure Check_Inlining (Subp : Entity_Id);
      --  If the original operation has a pragma Inline, propagate the flag
      --  to the internal body, for possible inlining later on. The source
      --  operation is invisible to the back-end and is never actually called.

      function Discriminated_Size (Comp : Entity_Id) return Boolean;
      --  If a component size is not static then a warning will be emitted
      --  in Ravenscar or other restricted contexts. When a component is non-
      --  static because of a discriminant constraint we can specialize the
      --  warning by mentioning discriminants explicitly.

      procedure Expand_Entry_Declaration (Decl : Node_Id);
      --  Create the entry barrier and the procedure body for entry declaration
      --  Decl. All generated subprograms are added to Entry_Bodies_Array.

      function Static_Component_Size (Comp : Entity_Id) return Boolean;
      --  When compiling under the Ravenscar profile, private components must
      --  have a static size, or else a protected object  will require heap
      --  allocation, violating the corresponding restriction. It is preferable
      --  to make this check here, because it provides a better error message
      --  than the back-end, which refers to the object as a whole.

      procedure Register_Handler;
      --  For a protected operation that is an interrupt handler, add the
      --  freeze action that will register it as such.

      --------------------
      -- Check_Inlining --
      --------------------

      procedure Check_Inlining (Subp : Entity_Id) is
      begin
         if Is_Inlined (Subp) then
            Set_Is_Inlined (Protected_Body_Subprogram (Subp));
            Set_Is_Inlined (Subp, False);
         end if;
      end Check_Inlining;

      ------------------------
      -- Discriminated_Size --
      ------------------------

      function Discriminated_Size (Comp : Entity_Id) return Boolean is
         Typ   : constant Entity_Id := Etype (Comp);
         Index : Node_Id;

         function Non_Static_Bound (Bound : Node_Id) return Boolean;
         --  Check whether the bound of an index is non-static and does denote
         --  a discriminant, in which case any protected object of the type
         --  will have a non-static size.

         ----------------------
         -- Non_Static_Bound --
         ----------------------

         function Non_Static_Bound (Bound : Node_Id) return Boolean is
         begin
            if Is_OK_Static_Expression (Bound) then
               return False;

            elsif Is_Entity_Name (Bound)
              and then Present (Discriminal_Link (Entity (Bound)))
            then
               return False;

            else
               return True;
            end if;
         end Non_Static_Bound;

      --  Start of processing for Discriminated_Size

      begin
         if not Is_Array_Type (Typ) then
            return False;
         end if;

         if Ekind (Typ) = E_Array_Subtype then
            Index := First_Index (Typ);
            while Present (Index) loop
               if Non_Static_Bound (Low_Bound (Index))
                 or else Non_Static_Bound (High_Bound (Index))
               then
                  return False;
               end if;

               Next_Index (Index);
            end loop;

            return True;
         end if;

         return False;
      end Discriminated_Size;

      ---------------------------
      -- Static_Component_Size --
      ---------------------------

      function Static_Component_Size (Comp : Entity_Id) return Boolean is
         Typ : constant Entity_Id := Etype (Comp);
         C   : Entity_Id;

      begin
         if Is_Scalar_Type (Typ) then
            return True;

         elsif Is_Array_Type (Typ) then
            return Compile_Time_Known_Bounds (Typ);

         elsif Is_Record_Type (Typ) then
            C := First_Component (Typ);
            while Present (C) loop
               if not Static_Component_Size (C) then
                  return False;
               end if;

               Next_Component (C);
            end loop;

            return True;

         --  Any other type will be checked by the back-end

         else
            return True;
         end if;
      end Static_Component_Size;

      ------------------------------
      -- Expand_Entry_Declaration --
      ------------------------------

      procedure Expand_Entry_Declaration (Decl : Node_Id) is
         Ent_Id : constant Entity_Id := Defining_Entity (Decl);
         Bar_Id : Entity_Id;
         Bod_Id : Entity_Id;
         Subp   : Node_Id;

      begin
         E_Count := E_Count + 1;

         --  Create the protected body subprogram

         Bod_Id :=
           Make_Defining_Identifier (Loc,
             Chars => Build_Selected_Name (Prot_Typ, Ent_Id, 'E'));
         Set_Protected_Body_Subprogram (Ent_Id, Bod_Id);

         Subp :=
           Make_Subprogram_Declaration (Loc,
             Specification =>
               Build_Protected_Entry_Specification (Loc, Bod_Id, Ent_Id));

         Insert_After (Current_Node, Subp);
         Current_Node := Subp;

         Analyze (Subp);

         --  Build a wrapper procedure to handle contract cases, preconditions,
         --  and postconditions.

         Build_Contract_Wrapper (Ent_Id, N);

         --  Create the barrier function

         Bar_Id :=
           Make_Defining_Identifier (Loc,
             Chars => Build_Selected_Name (Prot_Typ, Ent_Id, 'B'));
         Set_Barrier_Function (Ent_Id, Bar_Id);

         Subp :=
           Make_Subprogram_Declaration (Loc,
             Specification =>
               Build_Barrier_Function_Specification (Loc, Bar_Id));
         Set_Is_Entry_Barrier_Function (Subp);

         Insert_After (Current_Node, Subp);
         Current_Node := Subp;

         Analyze (Subp);

         Set_Protected_Body_Subprogram (Bar_Id, Bar_Id);
         Set_Scope (Bar_Id, Scope (Ent_Id));

         --  Collect pointers to the protected subprogram and the barrier
         --  of the current entry, for insertion into Entry_Bodies_Array.

         Append_To (Expressions (Entries_Aggr),
           Make_Aggregate (Loc,
             Expressions => New_List (
               Make_Attribute_Reference (Loc,
                 Prefix         => New_Occurrence_Of (Bar_Id, Loc),
                 Attribute_Name => Name_Unrestricted_Access),
               Make_Attribute_Reference (Loc,
                 Prefix         => New_Occurrence_Of (Bod_Id, Loc),
                 Attribute_Name => Name_Unrestricted_Access))));
      end Expand_Entry_Declaration;

      ----------------------
      -- Register_Handler --
      ----------------------

      procedure Register_Handler is

         --  All semantic checks already done in Sem_Prag

         Prot_Proc    : constant Entity_Id :=
                          Defining_Unit_Name (Specification (Current_Node));

         Proc_Address : constant Node_Id :=
                          Make_Attribute_Reference (Loc,
                            Prefix         =>
                              New_Occurrence_Of (Prot_Proc, Loc),
                            Attribute_Name => Name_Address);

         RTS_Call     : constant Entity_Id :=
                          Make_Procedure_Call_Statement (Loc,
                            Name                   =>
                              New_Occurrence_Of
                                (RTE (RE_Register_Interrupt_Handler), Loc),
                            Parameter_Associations => New_List (Proc_Address));
      begin
         Append_Freeze_Action (Prot_Proc, RTS_Call);
      end Register_Handler;

      --  Local variables

      Body_Arr     : Node_Id;
      Body_Id      : Entity_Id;
      Cdecls       : List_Id;
      Comp         : Node_Id;
      Expr         : Node_Id;
      New_Priv     : Node_Id;
      Obj_Def      : Node_Id;
      Object_Comp  : Node_Id;
      Priv         : Node_Id;
      Rec_Decl     : Node_Id;
      Sub          : Node_Id;

   --  Start of processing for Expand_N_Protected_Type_Declaration

   begin
      if Present (Corresponding_Record_Type (Prot_Typ)) then
         return;
      else
         Rec_Decl := Build_Corresponding_Record (N, Prot_Typ, Loc);
      end if;

      Cdecls := Component_Items (Component_List (Type_Definition (Rec_Decl)));

      Qualify_Entity_Names (N);

      --  If the type has discriminants, their occurrences in the declaration
      --  have been replaced by the corresponding discriminals. For components
      --  that are constrained by discriminants, their homologues in the
      --  corresponding record type must refer to the discriminants of that
      --  record, so we must apply a new renaming to subtypes_indications:

      --     protected discriminant => discriminal => record discriminant

      --  This replacement is not applied to default expressions, for which
      --  the discriminal is correct.

      if Has_Discriminants (Prot_Typ) then
         declare
            Disc : Entity_Id;
            Decl : Node_Id;

         begin
            Disc := First_Discriminant (Prot_Typ);
            Decl := First (Discriminant_Specifications (Rec_Decl));
            while Present (Disc) loop
               Append_Elmt (Discriminal (Disc), Discr_Map);
               Append_Elmt (Defining_Identifier (Decl), Discr_Map);
               Next_Discriminant (Disc);
               Next (Decl);
            end loop;
         end;
      end if;

      --  Fill in the component declarations

      --  Add components for entry families. For each entry family, create an
      --  anonymous type declaration with the same size, and analyze the type.

      Collect_Entry_Families (Loc, Cdecls, Current_Node, Prot_Typ);

      pragma Assert (Present (Pdef));

      Insert_After (Current_Node, Rec_Decl);
      Current_Node := Rec_Decl;

      --  Add private field components

      if Present (Private_Declarations (Pdef)) then
         Priv := First (Private_Declarations (Pdef));
         while Present (Priv) loop
            if Nkind (Priv) = N_Component_Declaration then
               if not Static_Component_Size (Defining_Identifier (Priv)) then

                  --  When compiling for a restricted profile, the private
                  --  components must have a static size. If not, this is an
                  --  error for a single protected declaration, and rates a
                  --  warning on a protected type declaration.

                  if not Comes_From_Source (Prot_Typ) then

                     --  It's ok to be checking this restriction at expansion
                     --  time, because this is only for the restricted profile,
                     --  which is not subject to strict RM conformance, so it
                     --  is OK to miss this check in -gnatc mode.

                     Check_Restriction (No_Implicit_Heap_Allocations, Priv);
                     Check_Restriction
                       (No_Implicit_Protected_Object_Allocations, Priv);

                  elsif Restriction_Active (No_Implicit_Heap_Allocations) then
                     if not Discriminated_Size (Defining_Identifier (Priv))
                     then
                        --  Any object of the type will be  non-static.

                        Error_Msg_N ("component has non-static size??", Priv);
                        Error_Msg_NE
                          ("\creation of protected object of type& will "
                           & "violate restriction "
                           & "No_Implicit_Heap_Allocations??", Priv, Prot_Typ);
                     else

                        --  Object will be non-static if discriminants are.

                        Error_Msg_NE
                          ("creation of protected object of type& with "
                           &  "non-static discriminants  will violate"
                           & " restriction No_Implicit_Heap_Allocations??",
                           Priv, Prot_Typ);
                     end if;

                  --  Likewise for No_Implicit_Protected_Object_Allocations

                  elsif Restriction_Active
                    (No_Implicit_Protected_Object_Allocations)
                  then
                     if not Discriminated_Size (Defining_Identifier (Priv))
                     then
                        --  Any object of the type will be  non-static.

                        Error_Msg_N ("component has non-static size??", Priv);
                        Error_Msg_NE
                          ("\creation of protected object of type& will "
                           & "violate restriction "
                           & "No_Implicit_Protected_Object_Allocations??",
                           Priv, Prot_Typ);
                     else
                        --  Object will be non-static if discriminants are.

                        Error_Msg_NE
                          ("creation of protected object of type& with "
                           & "non-static discriminants  will violate "
                           & "restriction "
                           & "No_Implicit_Protected_Object_Allocations??",
                           Priv, Prot_Typ);
                     end if;
                  end if;
               end if;

               --  The component definition consists of a subtype indication,
               --  or (in Ada 2005) an access definition. Make a copy of the
               --  proper definition.

               declare
                  Old_Comp : constant Node_Id   := Component_Definition (Priv);
                  Oent     : constant Entity_Id := Defining_Identifier (Priv);
                  Nent     : constant Entity_Id :=
                               Make_Defining_Identifier (Sloc (Oent),
                                 Chars => Chars (Oent));
                  New_Comp : Node_Id;

               begin
                  if Present (Subtype_Indication (Old_Comp)) then
                     New_Comp :=
                       Make_Component_Definition (Sloc (Oent),
                         Aliased_Present    => False,
                         Subtype_Indication =>
                           New_Copy_Tree
                             (Subtype_Indication (Old_Comp), Discr_Map));
                  else
                     New_Comp :=
                       Make_Component_Definition (Sloc (Oent),
                         Aliased_Present    => False,
                         Access_Definition  =>
                           New_Copy_Tree
                             (Access_Definition (Old_Comp), Discr_Map));
                  end if;

                  New_Priv :=
                    Make_Component_Declaration (Loc,
                      Defining_Identifier  => Nent,
                      Component_Definition => New_Comp,
                      Expression           => Expression (Priv));

                  Set_Has_Per_Object_Constraint (Nent,
                    Has_Per_Object_Constraint (Oent));

                  Append_To (Cdecls, New_Priv);
               end;

            elsif Nkind (Priv) = N_Subprogram_Declaration then

               --  Make the unprotected version of the subprogram available
               --  for expansion of intra object calls. There is need for
               --  a protected version only if the subprogram is an interrupt
               --  handler, otherwise  this operation can only be called from
               --  within the body.

               Sub :=
                 Make_Subprogram_Declaration (Loc,
                   Specification =>
                     Build_Protected_Sub_Specification
                       (Priv, Prot_Typ, Unprotected_Mode));

               Insert_After (Current_Node, Sub);
               Analyze (Sub);

               Set_Protected_Body_Subprogram
                 (Defining_Unit_Name (Specification (Priv)),
                  Defining_Unit_Name (Specification (Sub)));
               Check_Inlining (Defining_Unit_Name (Specification (Priv)));
               Current_Node := Sub;

               Sub :=
                 Make_Subprogram_Declaration (Loc,
                   Specification =>
                     Build_Protected_Sub_Specification
                       (Priv, Prot_Typ, Protected_Mode));

               Insert_After (Current_Node, Sub);
               Analyze (Sub);
               Current_Node := Sub;

               if Is_Interrupt_Handler
                 (Defining_Unit_Name (Specification (Priv)))
               then
                  if not Restricted_Profile then
                     Register_Handler;
                  end if;
               end if;
            end if;

            Next (Priv);
         end loop;
      end if;

      --  Except for the lock-free implementation, append the _Object field
      --  with the right type to the component list. We need to compute the
      --  number of entries, and in some cases the number of Attach_Handler
      --  pragmas.

      if not Lock_Free_Active then
         declare
            Entry_Count_Expr   : constant Node_Id :=
                                   Build_Entry_Count_Expression
                                     (Prot_Typ, Cdecls, Loc);
            Num_Attach_Handler : Nat := 0;
            Protection_Subtype : Node_Id;
            Ritem              : Node_Id;

         begin
            if Has_Attach_Handler (Prot_Typ) then
               Ritem := First_Rep_Item (Prot_Typ);
               while Present (Ritem) loop
                  if Nkind (Ritem) = N_Pragma
                    and then Pragma_Name (Ritem) = Name_Attach_Handler
                  then
                     Num_Attach_Handler := Num_Attach_Handler + 1;
                  end if;

                  Next_Rep_Item (Ritem);
               end loop;
            end if;

            --  Determine the proper protection type. There are two special
            --  cases: 1) when the protected type has dynamic interrupt
            --  handlers, and 2) when it has static handlers and we use a
            --  restricted profile.

            if Has_Attach_Handler (Prot_Typ)
              and then not Restricted_Profile
            then
               Protection_Subtype :=
                 Make_Subtype_Indication (Loc,
                  Subtype_Mark =>
                    New_Occurrence_Of
                      (RTE (RE_Static_Interrupt_Protection), Loc),
                  Constraint   =>
                    Make_Index_Or_Discriminant_Constraint (Loc,
                      Constraints => New_List (
                        Entry_Count_Expr,
                        Make_Integer_Literal (Loc, Num_Attach_Handler))));

            elsif Has_Interrupt_Handler (Prot_Typ)
              and then not Restriction_Active (No_Dynamic_Attachment)
            then
               Protection_Subtype :=
                 Make_Subtype_Indication (Loc,
                   Subtype_Mark =>
                     New_Occurrence_Of
                       (RTE (RE_Dynamic_Interrupt_Protection), Loc),
                   Constraint   =>
                     Make_Index_Or_Discriminant_Constraint (Loc,
                       Constraints => New_List (Entry_Count_Expr)));

            else
               case Corresponding_Runtime_Package (Prot_Typ) is
                  when System_Tasking_Protected_Objects_Entries =>
                     Protection_Subtype :=
                        Make_Subtype_Indication (Loc,
                          Subtype_Mark =>
                            New_Occurrence_Of
                              (RTE (RE_Protection_Entries), Loc),
                          Constraint   =>
                            Make_Index_Or_Discriminant_Constraint (Loc,
                              Constraints => New_List (Entry_Count_Expr)));

                  when System_Tasking_Protected_Objects_Single_Entry =>
                     Protection_Subtype :=
                       New_Occurrence_Of (RTE (RE_Protection_Entry), Loc);

                  when System_Tasking_Protected_Objects =>
                     Protection_Subtype :=
                       New_Occurrence_Of (RTE (RE_Protection), Loc);

                  when others =>
                     raise Program_Error;
               end case;
            end if;

            Object_Comp :=
              Make_Component_Declaration (Loc,
                Defining_Identifier  =>
                  Make_Defining_Identifier (Loc, Name_uObject),
                Component_Definition =>
                  Make_Component_Definition (Loc,
                    Aliased_Present    => True,
                    Subtype_Indication => Protection_Subtype));
         end;

         --  Put the _Object component after the private component so that it
         --  be finalized early as required by 9.4 (20)

         Append_To (Cdecls, Object_Comp);
      end if;

      --  Analyze the record declaration immediately after construction,
      --  because the initialization procedure is needed for single object
      --  declarations before the next entity is analyzed (the freeze call
      --  that generates this initialization procedure is found below).

      Analyze (Rec_Decl, Suppress => All_Checks);

      --  Ada 2005 (AI-345): Construct the primitive entry wrappers before
      --  the corresponding record is frozen. If any wrappers are generated,
      --  Current_Node is updated accordingly.

      if Ada_Version >= Ada_2005 then
         Build_Wrapper_Specs (Loc, Prot_Typ, Current_Node);
      end if;

      --  Collect pointers to entry bodies and their barriers, to be placed
      --  in the Entry_Bodies_Array for the type. For each entry/family we
      --  add an expression to the aggregate which is the initial value of
      --  this array. The array is declared after all protected subprograms.

      if Has_Entries (Prot_Typ) then
         Entries_Aggr := Make_Aggregate (Loc, Expressions => New_List);
      else
         Entries_Aggr := Empty;
      end if;

      --  Build two new procedure specifications for each protected subprogram;
      --  one to call from outside the object and one to call from inside.
      --  Build a barrier function and an entry body action procedure
      --  specification for each protected entry. Initialize the entry body
      --  array. If subprogram is flagged as eliminated, do not generate any
      --  internal operations.

      E_Count := 0;
      Comp := First (Visible_Declarations (Pdef));
      while Present (Comp) loop
         if Nkind (Comp) = N_Subprogram_Declaration then
            Sub :=
              Make_Subprogram_Declaration (Loc,
                Specification =>
                  Build_Protected_Sub_Specification
                    (Comp, Prot_Typ, Unprotected_Mode));

            Insert_After (Current_Node, Sub);
            Analyze (Sub);

            Set_Protected_Body_Subprogram
              (Defining_Unit_Name (Specification (Comp)),
               Defining_Unit_Name (Specification (Sub)));
            Check_Inlining (Defining_Unit_Name (Specification (Comp)));

            --  Make the protected version of the subprogram available for
            --  expansion of external calls.

            Current_Node := Sub;

            Sub :=
              Make_Subprogram_Declaration (Loc,
                Specification =>
                  Build_Protected_Sub_Specification
                    (Comp, Prot_Typ, Protected_Mode));

            Insert_After (Current_Node, Sub);
            Analyze (Sub);

            Current_Node := Sub;

            --  Generate an overriding primitive operation specification for
            --  this subprogram if the protected type implements an interface
            --  and Build_Wrapper_Spec did not generate its wrapper.

            if Ada_Version >= Ada_2005
              and then
                Present (Interfaces (Corresponding_Record_Type (Prot_Typ)))
            then
               declare
                  Found     : Boolean := False;
                  Prim_Elmt : Elmt_Id;
                  Prim_Op   : Node_Id;

               begin
                  Prim_Elmt :=
                    First_Elmt
                      (Primitive_Operations
                        (Corresponding_Record_Type (Prot_Typ)));

                  while Present (Prim_Elmt) loop
                     Prim_Op := Node (Prim_Elmt);

                     if Is_Primitive_Wrapper (Prim_Op)
                       and then Wrapped_Entity (Prim_Op) =
                                  Defining_Entity (Specification (Comp))
                     then
                        Found := True;
                        exit;
                     end if;

                     Next_Elmt (Prim_Elmt);
                  end loop;

                  if not Found then
                     Sub :=
                       Make_Subprogram_Declaration (Loc,
                         Specification =>
                           Build_Protected_Sub_Specification
                             (Comp, Prot_Typ, Dispatching_Mode));

                     Insert_After (Current_Node, Sub);
                     Analyze (Sub);

                     Current_Node := Sub;
                  end if;
               end;
            end if;

            --  If a pragma Interrupt_Handler applies, build and add a call to
            --  Register_Interrupt_Handler to the freezing actions of the
            --  protected version (Current_Node) of the subprogram:

            --    system.interrupts.register_interrupt_handler
            --       (prot_procP'address);

            if not Restricted_Profile
              and then Is_Interrupt_Handler
                         (Defining_Unit_Name (Specification (Comp)))
            then
               Register_Handler;
            end if;

         elsif Nkind (Comp) = N_Entry_Declaration then
            Expand_Entry_Declaration (Comp);
         end if;

         Next (Comp);
      end loop;

      --  If there are some private entry declarations, expand it as if they
      --  were visible entries.

      if Present (Private_Declarations (Pdef)) then
         Comp := First (Private_Declarations (Pdef));
         while Present (Comp) loop
            if Nkind (Comp) = N_Entry_Declaration then
               Expand_Entry_Declaration (Comp);
            end if;

            Next (Comp);
         end loop;
      end if;

      --  Create the declaration of an array object which contains the values
      --  of aspect/pragma Max_Queue_Length for all entries of the protected
      --  type. This object is later passed to the appropriate protected object
      --  initialization routine.

      if Has_Entries (Prot_Typ)
        and then Corresponding_Runtime_Package (Prot_Typ) =
                    System_Tasking_Protected_Objects_Entries
      then
         declare
            Count      : Int;
            Item       : Entity_Id;
            Max_Vals   : Node_Id;
            Maxes      : List_Id;
            Maxes_Id   : Entity_Id;
            Need_Array : Boolean := False;

         begin
            --  First check if there is any Max_Queue_Length pragma

            Item := First_Entity (Prot_Typ);
            while Present (Item) loop
               if Is_Entry (Item) and then Has_Max_Queue_Length (Item) then
                  Need_Array := True;
                  exit;
               end if;

               Next_Entity (Item);
            end loop;

            --  Gather the Max_Queue_Length values of all entries in a list. A
            --  value of zero indicates that the entry has no limitation on its
            --  queue length.

            if Need_Array then
               Count := 0;
               Item  := First_Entity (Prot_Typ);
               Maxes := New_List;
               while Present (Item) loop
                  if Is_Entry (Item) then
                     Count := Count + 1;
                     Append_To (Maxes,
                       Make_Integer_Literal
                         (Loc, Get_Max_Queue_Length (Item)));
                  end if;

                  Next_Entity (Item);
               end loop;

               --  Create the declaration of the array object. Generate:

               --    Maxes_Id : aliased constant
               --                 Protected_Entry_Queue_Max_Array
               --                   (1 .. Count) := (..., ...);

               Maxes_Id :=
                 Make_Defining_Identifier (Loc,
                   Chars => New_External_Name (Chars (Prot_Typ), 'B'));

               Max_Vals :=
                 Make_Object_Declaration (Loc,
                   Defining_Identifier => Maxes_Id,
                   Aliased_Present     => True,
                   Constant_Present    => True,
                   Object_Definition   =>
                     Make_Subtype_Indication (Loc,
                       Subtype_Mark =>
                         New_Occurrence_Of
                           (RTE (RE_Protected_Entry_Queue_Max_Array), Loc),
                       Constraint   =>
                         Make_Index_Or_Discriminant_Constraint (Loc,
                           Constraints => New_List (
                             Make_Range (Loc,
                               Make_Integer_Literal (Loc, 1),
                               Make_Integer_Literal (Loc, Count))))),
                   Expression          => Make_Aggregate (Loc, Maxes));

               --  A pointer to this array will be placed in the corresponding
               --  record by its initialization procedure so this needs to be
               --  analyzed here.

               Insert_After (Current_Node, Max_Vals);
               Current_Node := Max_Vals;
               Analyze (Max_Vals);

               Set_Entry_Max_Queue_Lengths_Array (Prot_Typ, Maxes_Id);
            end if;
         end;
      end if;

      --  Emit declaration for Entry_Bodies_Array, now that the addresses of
      --  all protected subprograms have been collected.

      if Has_Entries (Prot_Typ) then
         Body_Id :=
           Make_Defining_Identifier (Sloc (Prot_Typ),
             Chars => New_External_Name (Chars (Prot_Typ), 'A'));

         case Corresponding_Runtime_Package (Prot_Typ) is
            when System_Tasking_Protected_Objects_Entries =>
               Expr    := Entries_Aggr;
               Obj_Def :=
                  Make_Subtype_Indication (Loc,
                    Subtype_Mark =>
                      New_Occurrence_Of
                        (RTE (RE_Protected_Entry_Body_Array), Loc),
                    Constraint   =>
                      Make_Index_Or_Discriminant_Constraint (Loc,
                        Constraints => New_List (
                          Make_Range (Loc,
                            Make_Integer_Literal (Loc, 1),
                            Make_Integer_Literal (Loc, E_Count)))));

            when System_Tasking_Protected_Objects_Single_Entry =>
               Expr    := Remove_Head (Expressions (Entries_Aggr));
               Obj_Def := New_Occurrence_Of (RTE (RE_Entry_Body), Loc);

            when others =>
               raise Program_Error;
         end case;

         Body_Arr :=
           Make_Object_Declaration (Loc,
             Defining_Identifier => Body_Id,
             Aliased_Present     => True,
             Constant_Present    => True,
             Object_Definition   => Obj_Def,
             Expression          => Expr);

         --  A pointer to this array will be placed in the corresponding record
         --  by its initialization procedure so this needs to be analyzed here.

         Insert_After (Current_Node, Body_Arr);
         Current_Node := Body_Arr;
         Analyze (Body_Arr);

         Set_Entry_Bodies_Array (Prot_Typ, Body_Id);

         --  Finally, build the function that maps an entry index into the
         --  corresponding body. A pointer to this function is placed in each
         --  object of the type. Except for a ravenscar-like profile (no abort,
         --  no entry queue, 1 entry)

         if Corresponding_Runtime_Package (Prot_Typ) =
              System_Tasking_Protected_Objects_Entries
         then
            Sub :=
              Make_Subprogram_Declaration (Loc,
                Specification => Build_Find_Body_Index_Spec (Prot_Typ));

            Insert_After (Current_Node, Sub);
            Analyze (Sub);
         end if;
      end if;
   end Expand_N_Protected_Type_Declaration;

   --------------------------------
   -- Expand_N_Requeue_Statement --
   --------------------------------

   --  A nondispatching requeue statement is expanded into one of four GNARLI
   --  operations, depending on the source and destination (task or protected
   --  object). A dispatching requeue statement is expanded into a call to the
   --  predefined primitive _Disp_Requeue. In addition, code is generated to
   --  jump around the remainder of processing for the original entry and, if
   --  the destination is (different) protected object, to attempt to service
   --  it. The following illustrates the various cases:

   --  procedure entE
   --    (O : System.Address;
   --     P : System.Address;
   --     E : Protected_Entry_Index)
   --  is
   --     <discriminant renamings>
   --     <private object renamings>
   --     type poVP is access poV;
   --     _object : ptVP := ptVP!(O);

   --  begin
   --     begin
   --        <start of statement sequence for entry>

   --        -- Requeue from one protected entry body to another protected
   --        -- entry.

   --        Requeue_Protected_Entry (
   --          _object._object'Access,
   --          new._object'Access,
   --          E,
   --          Abort_Present);
   --        return;

   --        <some more of the statement sequence for entry>

   --        --  Requeue from an entry body to a task entry

   --        Requeue_Protected_To_Task_Entry (
   --          New._task_id,
   --          E,
   --          Abort_Present);
   --        return;

   --        <rest of statement sequence for entry>
   --        Complete_Entry_Body (_object._object);

   --     exception
   --        when all others =>
   --           Exceptional_Complete_Entry_Body (
   --             _object._object, Get_GNAT_Exception);
   --     end;
   --  end entE;

   --  Requeue of a task entry call to a task entry

   --  Accept_Call (E, Ann);
   --     <start of statement sequence for accept statement>
   --     Requeue_Task_Entry (New._task_id, E, Abort_Present);
   --     goto Lnn;
   --     <rest of statement sequence for accept statement>
   --     <<Lnn>>
   --     Complete_Rendezvous;

   --  exception
   --     when all others =>
   --        Exceptional_Complete_Rendezvous (Get_GNAT_Exception);

   --  Requeue of a task entry call to a protected entry

   --  Accept_Call (E, Ann);
   --     <start of statement sequence for accept statement>
   --     Requeue_Task_To_Protected_Entry (
   --       new._object'Access,
   --       E,
   --       Abort_Present);
   --     newS (new, Pnn);
   --     goto Lnn;
   --     <rest of statement sequence for accept statement>
   --     <<Lnn>>
   --     Complete_Rendezvous;

   --  exception
   --     when all others =>
   --        Exceptional_Complete_Rendezvous (Get_GNAT_Exception);

   --  Ada 2012 (AI05-0030): Dispatching requeue to an interface primitive
   --  marked by pragma Implemented (XXX, By_Entry).

   --  The requeue is inside a protected entry:

   --  procedure entE
   --    (O : System.Address;
   --     P : System.Address;
   --     E : Protected_Entry_Index)
   --  is
   --     <discriminant renamings>
   --     <private object renamings>
   --     type poVP is access poV;
   --     _object : ptVP := ptVP!(O);

   --  begin
   --     begin
   --        <start of statement sequence for entry>

   --        _Disp_Requeue
   --          (<interface class-wide object>,
   --           True,
   --           _object'Address,
   --           Ada.Tags.Get_Offset_Index
   --             (Tag (_object),
   --              <interface dispatch table index of target entry>),
   --           Abort_Present);
   --        return;

   --        <rest of statement sequence for entry>
   --        Complete_Entry_Body (_object._object);

   --     exception
   --        when all others =>
   --           Exceptional_Complete_Entry_Body (
   --             _object._object, Get_GNAT_Exception);
   --     end;
   --  end entE;

   --  The requeue is inside a task entry:

   --    Accept_Call (E, Ann);
   --     <start of statement sequence for accept statement>
   --     _Disp_Requeue
   --       (<interface class-wide object>,
   --        False,
   --        null,
   --        Ada.Tags.Get_Offset_Index
   --          (Tag (_object),
   --           <interface dispatch table index of target entrt>),
   --        Abort_Present);
   --     newS (new, Pnn);
   --     goto Lnn;
   --     <rest of statement sequence for accept statement>
   --     <<Lnn>>
   --     Complete_Rendezvous;

   --  exception
   --     when all others =>
   --        Exceptional_Complete_Rendezvous (Get_GNAT_Exception);

   --  Ada 2012 (AI05-0030): Dispatching requeue to an interface primitive
   --  marked by pragma Implemented (XXX, By_Protected_Procedure). The requeue
   --  statement is replaced by a dispatching call with actual parameters taken
   --  from the inner-most accept statement or entry body.

   --    Target.Primitive (Param1, ..., ParamN);

   --  Ada 2012 (AI05-0030): Dispatching requeue to an interface primitive
   --  marked by pragma Implemented (XXX, By_Any | Optional) or not marked
   --  at all.

   --    declare
   --       S : constant Offset_Index :=
   --             Get_Offset_Index (Tag (Concval), DT_Position (Ename));
   --       C : constant Prim_Op_Kind := Get_Prim_Op_Kind (Tag (Concval), S);

   --    begin
   --       if C = POK_Protected_Entry
   --         or else C = POK_Task_Entry
   --       then
   --          <statements for dispatching requeue>

   --       elsif C = POK_Protected_Procedure then
   --          <dispatching call equivalent>

   --       else
   --          raise Program_Error;
   --       end if;
   --    end;

   procedure Expand_N_Requeue_Statement (N : Node_Id) is
      Loc      : constant Source_Ptr := Sloc (N);
      Conc_Typ : Entity_Id;
      Concval  : Node_Id;
      Ename    : Node_Id;
      Index    : Node_Id;
      Old_Typ  : Entity_Id;

      function Build_Dispatching_Call_Equivalent return Node_Id;
      --  Ada 2012 (AI05-0030): N denotes a dispatching requeue statement of
      --  the form Concval.Ename. It is statically known that Ename is allowed
      --  to be implemented by a protected procedure. Create a dispatching call
      --  equivalent of Concval.Ename taking the actual parameters from the
      --  inner-most accept statement or entry body.

      function Build_Dispatching_Requeue return Node_Id;
      --  Ada 2012 (AI05-0030): N denotes a dispatching requeue statement of
      --  the form Concval.Ename. It is statically known that Ename is allowed
      --  to be implemented by a protected or a task entry. Create a call to
      --  primitive _Disp_Requeue which handles the low-level actions.

      function Build_Dispatching_Requeue_To_Any return Node_Id;
      --  Ada 2012 (AI05-0030): N denotes a dispatching requeue statement of
      --  the form Concval.Ename. Ename is either marked by pragma Implemented
      --  (XXX, By_Any | Optional) or not marked at all. Create a block which
      --  determines at runtime whether Ename denotes an entry or a procedure
      --  and perform the appropriate kind of dispatching select.

      function Build_Normal_Requeue return Node_Id;
      --  N denotes a nondispatching requeue statement to either a task or a
      --  protected entry. Build the appropriate runtime call to perform the
      --  action.

      function Build_Skip_Statement (Search : Node_Id) return Node_Id;
      --  For a protected entry, create a return statement to skip the rest of
      --  the entry body. Otherwise, create a goto statement to skip the rest
      --  of a task accept statement. The lookup for the enclosing entry body
      --  or accept statement starts from Search.

      ---------------------------------------
      -- Build_Dispatching_Call_Equivalent --
      ---------------------------------------

      function Build_Dispatching_Call_Equivalent return Node_Id is
         Call_Ent : constant Entity_Id := Entity (Ename);
         Obj      : constant Node_Id   := Original_Node (Concval);
         Acc_Ent  : Node_Id;
         Actuals  : List_Id;
         Formal   : Node_Id;
         Formals  : List_Id;

      begin
         --  Climb the parent chain looking for the inner-most entry body or
         --  accept statement.

         Acc_Ent := N;
         while Present (Acc_Ent)
           and then not Nkind_In (Acc_Ent, N_Accept_Statement,
                                           N_Entry_Body)
         loop
            Acc_Ent := Parent (Acc_Ent);
         end loop;

         --  A requeue statement should be housed inside an entry body or an
         --  accept statement at some level. If this is not the case, then the
         --  tree is malformed.

         pragma Assert (Present (Acc_Ent));

         --  Recover the list of formal parameters

         if Nkind (Acc_Ent) = N_Entry_Body then
            Acc_Ent := Entry_Body_Formal_Part (Acc_Ent);
         end if;

         Formals := Parameter_Specifications (Acc_Ent);

         --  Create the actual parameters for the dispatching call. These are
         --  simply copies of the entry body or accept statement formals in the
         --  same order as they appear.

         Actuals := No_List;

         if Present (Formals) then
            Actuals := New_List;
            Formal  := First (Formals);
            while Present (Formal) loop
               Append_To (Actuals,
                 Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
               Next (Formal);
            end loop;
         end if;

         --  Generate:
         --    Obj.Call_Ent (Actuals);

         return
           Make_Procedure_Call_Statement (Loc,
             Name =>
               Make_Selected_Component (Loc,
                 Prefix        => Make_Identifier (Loc, Chars (Obj)),
                 Selector_Name => Make_Identifier (Loc, Chars (Call_Ent))),

             Parameter_Associations => Actuals);
      end Build_Dispatching_Call_Equivalent;

      -------------------------------
      -- Build_Dispatching_Requeue --
      -------------------------------

      function Build_Dispatching_Requeue return Node_Id is
         Params : constant List_Id := New_List;

      begin
         --  Process the "with abort" parameter

         Prepend_To (Params,
           New_Occurrence_Of (Boolean_Literals (Abort_Present (N)), Loc));

         --  Process the entry wrapper's position in the primary dispatch
         --  table parameter. Generate:

         --    Ada.Tags.Get_Entry_Index
         --      (T        => To_Tag_Ptr (Obj'Address).all,
         --       Position =>
         --         Ada.Tags.Get_Offset_Index
         --           (Ada.Tags.Tag (Concval),
         --            <interface dispatch table position of Ename>));

         --  Note that Obj'Address is recursively expanded into a call to
         --  Base_Address (Obj).

         if Tagged_Type_Expansion then
            Prepend_To (Params,
              Make_Function_Call (Loc,
                Name => New_Occurrence_Of (RTE (RE_Get_Entry_Index), Loc),
                Parameter_Associations => New_List (

                  Make_Explicit_Dereference (Loc,
                    Unchecked_Convert_To (RTE (RE_Tag_Ptr),
                      Make_Attribute_Reference (Loc,
                        Prefix => New_Copy_Tree (Concval),
                        Attribute_Name => Name_Address))),

                  Make_Function_Call (Loc,
                    Name => New_Occurrence_Of (RTE (RE_Get_Offset_Index), Loc),
                    Parameter_Associations => New_List (
                      Unchecked_Convert_To (RTE (RE_Tag), Concval),
                      Make_Integer_Literal (Loc,
                        DT_Position (Entity (Ename))))))));

         --  VM targets

         else
            Prepend_To (Params,
              Make_Function_Call (Loc,
                Name => New_Occurrence_Of (RTE (RE_Get_Entry_Index), Loc),
                Parameter_Associations => New_List (

                  Make_Attribute_Reference (Loc,
                    Prefix         => Concval,
                    Attribute_Name => Name_Tag),

                  Make_Function_Call (Loc,
                    Name => New_Occurrence_Of (RTE (RE_Get_Offset_Index), Loc),

                    Parameter_Associations => New_List (

                      --  Obj_Tag

                      Make_Attribute_Reference (Loc,
                        Prefix => Concval,
                        Attribute_Name => Name_Tag),

                      --  Tag_Typ

                      Make_Attribute_Reference (Loc,
                        Prefix => New_Occurrence_Of (Etype (Concval), Loc),
                        Attribute_Name => Name_Tag),

                      --  Position

                      Make_Integer_Literal (Loc,
                        DT_Position (Entity (Ename))))))));
         end if;

         --  Specific actuals for protected to XXX requeue

         if Is_Protected_Type (Old_Typ) then
            Prepend_To (Params,
              Make_Attribute_Reference (Loc,        --  _object'Address
                Prefix =>
                  Concurrent_Ref (New_Occurrence_Of (Old_Typ, Loc)),
                Attribute_Name => Name_Address));

            Prepend_To (Params,                     --  True
              New_Occurrence_Of (Standard_True, Loc));

         --  Specific actuals for task to XXX requeue

         else
            pragma Assert (Is_Task_Type (Old_Typ));

            Prepend_To (Params,                     --  null
              New_Occurrence_Of (RTE (RE_Null_Address), Loc));

            Prepend_To (Params,                     --  False
              New_Occurrence_Of (Standard_False, Loc));
         end if;

         --  Add the object parameter

         Prepend_To (Params, New_Copy_Tree (Concval));

         --  Generate:
         --    _Disp_Requeue (<Params>);

         --  Find entity for Disp_Requeue operation, which belongs to
         --  the type and may not be directly visible.

         declare
            Elmt : Elmt_Id;
            Op   : Entity_Id;

         begin
            Elmt := First_Elmt (Primitive_Operations (Etype (Conc_Typ)));
            while Present (Elmt) loop
               Op := Node (Elmt);
               exit when Chars (Op) = Name_uDisp_Requeue;
               Next_Elmt (Elmt);
            end loop;

            return
              Make_Procedure_Call_Statement (Loc,
                Name                   => New_Occurrence_Of (Op, Loc),
                Parameter_Associations => Params);
         end;
      end Build_Dispatching_Requeue;

      --------------------------------------
      -- Build_Dispatching_Requeue_To_Any --
      --------------------------------------

      function Build_Dispatching_Requeue_To_Any return Node_Id is
         Call_Ent : constant Entity_Id := Entity (Ename);
         Obj      : constant Node_Id   := Original_Node (Concval);
         Skip     : constant Node_Id   := Build_Skip_Statement (N);
         C        : Entity_Id;
         Decls    : List_Id;
         S        : Entity_Id;
         Stmts    : List_Id;

      begin
         Decls := New_List;
         Stmts := New_List;

         --  Dispatch table slot processing, generate:
         --    S : Integer;

         S := Build_S (Loc, Decls);

         --  Call kind processing, generate:
         --    C : Ada.Tags.Prim_Op_Kind;

         C := Build_C (Loc, Decls);

         --  Generate:
         --    S := Ada.Tags.Get_Offset_Index
         --           (Ada.Tags.Tag (Obj), DT_Position (Call_Ent));

         Append_To (Stmts, Build_S_Assignment (Loc, S, Obj, Call_Ent));

         --  Generate:
         --    _Disp_Get_Prim_Op_Kind (Obj, S, C);

         Append_To (Stmts,
           Make_Procedure_Call_Statement (Loc,
             Name =>
               New_Occurrence_Of (
                 Find_Prim_Op (Etype (Etype (Obj)),
                   Name_uDisp_Get_Prim_Op_Kind),
                 Loc),
             Parameter_Associations => New_List (
               New_Copy_Tree (Obj),
               New_Occurrence_Of (S, Loc),
               New_Occurrence_Of (C, Loc))));

         Append_To (Stmts,

            --  if C = POK_Protected_Entry
            --    or else C = POK_Task_Entry
            --  then

           Make_Implicit_If_Statement (N,
             Condition =>
               Make_Op_Or (Loc,
                 Left_Opnd =>
                   Make_Op_Eq (Loc,
                     Left_Opnd =>
                       New_Occurrence_Of (C, Loc),
                     Right_Opnd =>
                       New_Occurrence_Of (RTE (RE_POK_Protected_Entry), Loc)),

                 Right_Opnd =>
                   Make_Op_Eq (Loc,
                     Left_Opnd =>
                       New_Occurrence_Of (C, Loc),
                     Right_Opnd =>
                       New_Occurrence_Of (RTE (RE_POK_Task_Entry), Loc))),

               --  Dispatching requeue equivalent

             Then_Statements => New_List (
               Build_Dispatching_Requeue,
               Skip),

               --  elsif C = POK_Protected_Procedure then

             Elsif_Parts => New_List (
               Make_Elsif_Part (Loc,
                 Condition =>
                   Make_Op_Eq (Loc,
                     Left_Opnd =>
                       New_Occurrence_Of (C, Loc),
                     Right_Opnd =>
                       New_Occurrence_Of (
                         RTE (RE_POK_Protected_Procedure), Loc)),

                  --  Dispatching call equivalent

                 Then_Statements => New_List (
                   Build_Dispatching_Call_Equivalent))),

            --  else
            --     raise Program_Error;
            --  end if;

             Else_Statements => New_List (
               Make_Raise_Program_Error (Loc,
                 Reason => PE_Explicit_Raise))));

         --  Wrap everything into a block

         return
           Make_Block_Statement (Loc,
             Declarations => Decls,
             Handled_Statement_Sequence =>
               Make_Handled_Sequence_Of_Statements (Loc,
                 Statements => Stmts));
      end Build_Dispatching_Requeue_To_Any;

      --------------------------
      -- Build_Normal_Requeue --
      --------------------------

      function Build_Normal_Requeue return Node_Id is
         Params  : constant List_Id := New_List;
         Param   : Node_Id;
         RT_Call : Node_Id;

      begin
         --  Process the "with abort" parameter

         Prepend_To (Params,
           New_Occurrence_Of (Boolean_Literals (Abort_Present (N)), Loc));

         --  Add the index expression to the parameters. It is common among all
         --  four cases.

         Prepend_To (Params,
           Entry_Index_Expression (Loc, Entity (Ename), Index, Conc_Typ));

         if Is_Protected_Type (Old_Typ) then
            declare
               Self_Param : Node_Id;

            begin
               Self_Param :=
                 Make_Attribute_Reference (Loc,
                   Prefix =>
                     Concurrent_Ref (New_Occurrence_Of (Old_Typ, Loc)),
                   Attribute_Name =>
                     Name_Unchecked_Access);

               --  Protected to protected requeue

               if Is_Protected_Type (Conc_Typ) then
                  RT_Call :=
                    New_Occurrence_Of (
                      RTE (RE_Requeue_Protected_Entry), Loc);

                  Param :=
                    Make_Attribute_Reference (Loc,
                      Prefix =>
                        Concurrent_Ref (Concval),
                      Attribute_Name =>
                        Name_Unchecked_Access);

               --  Protected to task requeue

               else pragma Assert (Is_Task_Type (Conc_Typ));
                  RT_Call :=
                    New_Occurrence_Of (
                      RTE (RE_Requeue_Protected_To_Task_Entry), Loc);

                  Param := Concurrent_Ref (Concval);
               end if;

               Prepend_To (Params, Param);
               Prepend_To (Params, Self_Param);
            end;

         else pragma Assert (Is_Task_Type (Old_Typ));

            --  Task to protected requeue

            if Is_Protected_Type (Conc_Typ) then
               RT_Call :=
                 New_Occurrence_Of (
                   RTE (RE_Requeue_Task_To_Protected_Entry), Loc);

               Param :=
                 Make_Attribute_Reference (Loc,
                   Prefix =>
                     Concurrent_Ref (Concval),
                   Attribute_Name =>
                     Name_Unchecked_Access);

            --  Task to task requeue

            else pragma Assert (Is_Task_Type (Conc_Typ));
               RT_Call :=
                 New_Occurrence_Of (RTE (RE_Requeue_Task_Entry), Loc);

               Param := Concurrent_Ref (Concval);
            end if;

            Prepend_To (Params, Param);
         end if;

         return
            Make_Procedure_Call_Statement (Loc,
              Name => RT_Call,
              Parameter_Associations => Params);
      end Build_Normal_Requeue;

      --------------------------
      -- Build_Skip_Statement --
      --------------------------

      function Build_Skip_Statement (Search : Node_Id) return Node_Id is
         Skip_Stmt : Node_Id;

      begin
         --  Build a return statement to skip the rest of the entire body

         if Is_Protected_Type (Old_Typ) then
            Skip_Stmt := Make_Simple_Return_Statement (Loc);

         --  If the requeue is within a task, find the end label of the
         --  enclosing accept statement and create a goto statement to it.

         else
            declare
               Acc   : Node_Id;
               Label : Node_Id;

            begin
               --  Climb the parent chain looking for the enclosing accept
               --  statement.

               Acc := Parent (Search);
               while Present (Acc)
                 and then Nkind (Acc) /= N_Accept_Statement
               loop
                  Acc := Parent (Acc);
               end loop;

               --  The last statement is the second label used for completing
               --  the rendezvous the usual way. The label we are looking for
               --  is right before it.

               Label :=
                 Prev (Last (Statements (Handled_Statement_Sequence (Acc))));

               pragma Assert (Nkind (Label) = N_Label);

               --  Generate a goto statement to skip the rest of the accept

               Skip_Stmt :=
                 Make_Goto_Statement (Loc,
                   Name =>
                     New_Occurrence_Of (Entity (Identifier (Label)), Loc));
            end;
         end if;

         Set_Analyzed (Skip_Stmt);

         return Skip_Stmt;
      end Build_Skip_Statement;

   --  Start of processing for Expand_N_Requeue_Statement

   begin
      --  Extract the components of the entry call

      Extract_Entry (N, Concval, Ename, Index);
      Conc_Typ := Etype (Concval);

      --  If the prefix is an access to class-wide type, dereference to get
      --  object and entry type.

      if Is_Access_Type (Conc_Typ) then
         Conc_Typ := Designated_Type (Conc_Typ);
         Rewrite (Concval,
           Make_Explicit_Dereference (Loc, Relocate_Node (Concval)));
         Analyze_And_Resolve (Concval, Conc_Typ);
      end if;

      --  Examine the scope stack in order to find nearest enclosing protected
      --  or task type. This will constitute our invocation source.

      Old_Typ := Current_Scope;
      while Present (Old_Typ)
        and then not Is_Protected_Type (Old_Typ)
        and then not Is_Task_Type (Old_Typ)
      loop
         Old_Typ := Scope (Old_Typ);
      end loop;

      --  Ada 2012 (AI05-0030): We have a dispatching requeue of the form
      --  Concval.Ename where the type of Concval is class-wide concurrent
      --  interface.

      if Ada_Version >= Ada_2012
        and then Present (Concval)
        and then Is_Class_Wide_Type (Conc_Typ)
        and then Is_Concurrent_Interface (Conc_Typ)
      then
         declare
            Has_Impl  : Boolean := False;
            Impl_Kind : Name_Id := No_Name;

         begin
            --  Check whether the Ename is flagged by pragma Implemented

            if Has_Rep_Pragma (Entity (Ename), Name_Implemented) then
               Has_Impl  := True;
               Impl_Kind := Implementation_Kind (Entity (Ename));
            end if;

            --  The procedure_or_entry_NAME is guaranteed to be overridden by
            --  an entry. Create a call to predefined primitive _Disp_Requeue.

            if Has_Impl and then Impl_Kind = Name_By_Entry then
               Rewrite (N, Build_Dispatching_Requeue);
               Analyze (N);
               Insert_After (N, Build_Skip_Statement (N));

            --  The procedure_or_entry_NAME is guaranteed to be overridden by
            --  a protected procedure. In this case the requeue is transformed
            --  into a dispatching call.

            elsif Has_Impl
              and then Impl_Kind = Name_By_Protected_Procedure
            then
               Rewrite (N, Build_Dispatching_Call_Equivalent);
               Analyze (N);

            --  The procedure_or_entry_NAME's implementation kind is either
            --  By_Any, Optional, or pragma Implemented was not applied at all.
            --  In this case a runtime test determines whether Ename denotes an
            --  entry or a protected procedure and performs the appropriate
            --  call.

            else
               Rewrite (N, Build_Dispatching_Requeue_To_Any);
               Analyze (N);
            end if;
         end;

      --  Processing for regular (nondispatching) requeues

      else
         Rewrite (N, Build_Normal_Requeue);
         Analyze (N);
         Insert_After (N, Build_Skip_Statement (N));
      end if;
   end Expand_N_Requeue_Statement;

   -------------------------------
   -- Expand_N_Selective_Accept --
   -------------------------------

   procedure Expand_N_Selective_Accept (N : Node_Id) is
      Loc            : constant Source_Ptr := Sloc (N);
      Alts           : constant List_Id    := Select_Alternatives (N);

      --  Note: in the below declarations a lot of new lists are allocated
      --  unconditionally which may well not end up being used. That's not
      --  a good idea since it wastes space gratuitously ???

      Accept_Case    : List_Id;
      Accept_List    : constant List_Id := New_List;

      Alt            : Node_Id;
      Alt_List       : constant List_Id := New_List;
      Alt_Stats      : List_Id;
      Ann            : Entity_Id := Empty;

      Check_Guard    : Boolean := True;

      Decls          : constant List_Id := New_List;
      Stats          : constant List_Id := New_List;
      Body_List      : constant List_Id := New_List;
      Trailing_List  : constant List_Id := New_List;

      Choices        : List_Id;
      Else_Present   : Boolean := False;
      Terminate_Alt  : Node_Id := Empty;
      Select_Mode    : Node_Id;

      Delay_Case     : List_Id;
      Delay_Count    : Integer := 0;
      Delay_Val      : Entity_Id;
      Delay_Index    : Entity_Id;
      Delay_Min      : Entity_Id;
      Delay_Num      : Pos := 1;
      Delay_Alt_List : List_Id := New_List;
      Delay_List     : constant List_Id := New_List;
      D              : Entity_Id;
      M              : Entity_Id;

      First_Delay    : Boolean := True;
      Guard_Open     : Entity_Id;

      End_Lab        : Node_Id;
      Index          : Pos := 1;
      Lab            : Node_Id;
      Num_Alts       : Nat;
      Num_Accept     : Nat := 0;
      Proc           : Node_Id;
      Time_Type      : Entity_Id;
      Select_Call    : Node_Id;

      Qnam : constant Entity_Id :=
               Make_Defining_Identifier (Loc, New_External_Name ('S', 0));

      Xnam : constant Entity_Id :=
               Make_Defining_Identifier (Loc, New_External_Name ('J', 1));

      -----------------------
      -- Local subprograms --
      -----------------------

      function Accept_Or_Raise return List_Id;
      --  For the rare case where delay alternatives all have guards, and
      --  all of them are closed, it is still possible that there were open
      --  accept alternatives with no callers. We must reexamine the
      --  Accept_List, and execute a selective wait with no else if some
      --  accept is open. If none, we raise program_error.

      procedure Add_Accept (Alt : Node_Id);
      --  Process a single accept statement in a select alternative. Build
      --  procedure for body of accept, and add entry to dispatch table with
      --  expression for guard, in preparation for call to run time select.

      function Make_And_Declare_Label (Num : Int) return Node_Id;
      --  Manufacture a label using Num as a serial number and declare it.
      --  The declaration is appended to Decls. The label marks the trailing
      --  statements of an accept or delay alternative.

      function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id;
      --  Build call to Selective_Wait runtime routine

      procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int);
      --  Add code to compare value of delay with previous values, and
      --  generate case entry for trailing statements.

      procedure Process_Accept_Alternative
        (Alt   : Node_Id;
         Index : Int;
         Proc  : Node_Id);
      --  Add code to call corresponding procedure, and branch to
      --  trailing statements, if any.

      ---------------------
      -- Accept_Or_Raise --
      ---------------------

      function Accept_Or_Raise return List_Id is
         Cond  : Node_Id;
         Stats : List_Id;
         J     : constant Entity_Id := Make_Temporary (Loc, 'J');

      begin
         --  We generate the following:

         --    for J in q'range loop
         --       if q(J).S /=null_task_entry then
         --          selective_wait (simple_mode,...);
         --          done := True;
         --          exit;
         --       end if;
         --    end loop;
         --
         --    if no rendez_vous then
         --       raise program_error;
         --    end if;

         --    Note that the code needs to know that the selector name
         --    in an Accept_Alternative is named S.

         Cond := Make_Op_Ne (Loc,
           Left_Opnd =>
             Make_Selected_Component (Loc,
               Prefix        =>
                 Make_Indexed_Component (Loc,
                   Prefix => New_Occurrence_Of (Qnam, Loc),
                     Expressions => New_List (New_Occurrence_Of (J, Loc))),
               Selector_Name => Make_Identifier (Loc, Name_S)),
           Right_Opnd =>
             New_Occurrence_Of (RTE (RE_Null_Task_Entry), Loc));

         Stats := New_List (
           Make_Implicit_Loop_Statement (N,
             Iteration_Scheme =>
               Make_Iteration_Scheme (Loc,
                 Loop_Parameter_Specification =>
                   Make_Loop_Parameter_Specification (Loc,
                     Defining_Identifier         => J,
                     Discrete_Subtype_Definition =>
                       Make_Attribute_Reference (Loc,
                         Prefix         => New_Occurrence_Of (Qnam, Loc),
                         Attribute_Name => Name_Range,
                         Expressions    => New_List (
                           Make_Integer_Literal (Loc, 1))))),

             Statements       => New_List (
               Make_Implicit_If_Statement (N,
                 Condition       =>  Cond,
                 Then_Statements => New_List (
                   Make_Select_Call (
                     New_Occurrence_Of (RTE (RE_Simple_Mode), Loc)),
                   Make_Exit_Statement (Loc))))));

         Append_To (Stats,
           Make_Raise_Program_Error (Loc,
             Condition => Make_Op_Eq (Loc,
               Left_Opnd  => New_Occurrence_Of (Xnam, Loc),
               Right_Opnd =>
                 New_Occurrence_Of (RTE (RE_No_Rendezvous), Loc)),
             Reason => PE_All_Guards_Closed));

         return Stats;
      end Accept_Or_Raise;

      ----------------
      -- Add_Accept --
      ----------------

      procedure Add_Accept (Alt : Node_Id) is
         Acc_Stm   : constant Node_Id    := Accept_Statement (Alt);
         Ename     : constant Node_Id    := Entry_Direct_Name (Acc_Stm);
         Eloc      : constant Source_Ptr := Sloc (Ename);
         Eent      : constant Entity_Id  := Entity (Ename);
         Index     : constant Node_Id    := Entry_Index (Acc_Stm);
         Null_Body : Node_Id;
         Proc_Body : Node_Id;
         PB_Ent    : Entity_Id;
         Expr      : Node_Id;
         Call      : Node_Id;

      begin
         if No (Ann) then
            Ann := Node (Last_Elmt (Accept_Address (Eent)));
         end if;

         if Present (Condition (Alt)) then
            Expr :=
              Make_If_Expression (Eloc, New_List (
                Condition (Alt),
                Entry_Index_Expression (Eloc, Eent, Index, Scope (Eent)),
                New_Occurrence_Of (RTE (RE_Null_Task_Entry), Eloc)));
         else
            Expr :=
              Entry_Index_Expression
                (Eloc, Eent, Index, Scope (Eent));
         end if;

         if Present (Handled_Statement_Sequence (Accept_Statement (Alt))) then
            Null_Body := New_Occurrence_Of (Standard_False, Eloc);

            --  Always add call to Abort_Undefer when generating code, since
            --  this is what the runtime expects (abort deferred in
            --  Selective_Wait). In CodePeer mode this only confuses the
            --  analysis with unknown calls, so don't do it.

            if not CodePeer_Mode then
               Call := Build_Runtime_Call (Loc, RE_Abort_Undefer);
               Insert_Before
                 (First (Statements (Handled_Statement_Sequence
                                       (Accept_Statement (Alt)))),
                  Call);
               Analyze (Call);
            end if;

            PB_Ent :=
              Make_Defining_Identifier (Eloc,
                New_External_Name (Chars (Ename), 'A', Num_Accept));

            if Comes_From_Source (Alt) then
               Set_Debug_Info_Needed (PB_Ent);
            end if;

            Proc_Body :=
              Make_Subprogram_Body (Eloc,
                Specification              =>
                  Make_Procedure_Specification (Eloc,
                    Defining_Unit_Name => PB_Ent),
                Declarations               => Declarations (Acc_Stm),
                Handled_Statement_Sequence =>
                  Build_Accept_Body (Accept_Statement (Alt)));

            --  During the analysis of the body of the accept statement, any
            --  zero cost exception handler records were collected in the
            --  Accept_Handler_Records field of the N_Accept_Alternative node.
            --  This is where we move them to where they belong, namely the
            --  newly created procedure.

            Set_Handler_Records (PB_Ent, Accept_Handler_Records (Alt));
            Append (Proc_Body, Body_List);

         else
            Null_Body := New_Occurrence_Of (Standard_True,  Eloc);

            --  if accept statement has declarations, insert above, given that
            --  we are not creating a body for the accept.

            if Present (Declarations (Acc_Stm)) then
               Insert_Actions (N, Declarations (Acc_Stm));
            end if;
         end if;

         Append_To (Accept_List,
           Make_Aggregate (Eloc, Expressions => New_List (Null_Body, Expr)));

         Num_Accept := Num_Accept + 1;
      end Add_Accept;

      ----------------------------
      -- Make_And_Declare_Label --
      ----------------------------

      function Make_And_Declare_Label (Num : Int) return Node_Id is
         Lab_Id : Node_Id;

      begin
         Lab_Id := Make_Identifier (Loc, New_External_Name ('L', Num));
         Lab :=
           Make_Label (Loc, Lab_Id);

         Append_To (Decls,
           Make_Implicit_Label_Declaration (Loc,
             Defining_Identifier  =>
               Make_Defining_Identifier (Loc, Chars (Lab_Id)),
             Label_Construct      => Lab));

         return Lab;
      end Make_And_Declare_Label;

      ----------------------
      -- Make_Select_Call --
      ----------------------

      function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id is
         Params : constant List_Id := New_List;

      begin
         Append_To (Params,
           Make_Attribute_Reference (Loc,
             Prefix         => New_Occurrence_Of (Qnam, Loc),
             Attribute_Name => Name_Unchecked_Access));
         Append_To (Params, Select_Mode);
         Append_To (Params, New_Occurrence_Of (Ann, Loc));
         Append_To (Params, New_Occurrence_Of (Xnam, Loc));

         return
           Make_Procedure_Call_Statement (Loc,
             Name => New_Occurrence_Of (RTE (RE_Selective_Wait), Loc),
             Parameter_Associations => Params);
      end Make_Select_Call;

      --------------------------------
      -- Process_Accept_Alternative --
      --------------------------------

      procedure Process_Accept_Alternative
        (Alt   : Node_Id;
         Index : Int;
         Proc  : Node_Id)
      is
         Astmt     : constant Node_Id := Accept_Statement (Alt);
         Alt_Stats : List_Id;

      begin
         Adjust_Condition (Condition (Alt));

         --  Accept with body

         if Present (Handled_Statement_Sequence (Astmt)) then
            Alt_Stats :=
              New_List (
                Make_Procedure_Call_Statement (Sloc (Proc),
                  Name =>
                    New_Occurrence_Of
                      (Defining_Unit_Name (Specification (Proc)),
                       Sloc (Proc))));

         --  Accept with no body (followed by trailing statements)

         else
            Alt_Stats := Empty_List;
         end if;

         Ensure_Statement_Present (Sloc (Astmt), Alt);

         --  After the call, if any, branch to trailing statements, if any.
         --  We create a label for each, as well as the corresponding label
         --  declaration.

         if not Is_Empty_List (Statements (Alt)) then
            Lab := Make_And_Declare_Label (Index);
            Append (Lab, Trailing_List);
            Append_List (Statements (Alt), Trailing_List);
            Append_To (Trailing_List,
              Make_Goto_Statement (Loc,
                Name => New_Copy (Identifier (End_Lab))));

         else
            Lab := End_Lab;
         end if;

         Append_To (Alt_Stats,
           Make_Goto_Statement (Loc, Name => New_Copy (Identifier (Lab))));

         Append_To (Alt_List,
           Make_Case_Statement_Alternative (Loc,
             Discrete_Choices => New_List (Make_Integer_Literal (Loc, Index)),
             Statements       => Alt_Stats));
      end Process_Accept_Alternative;

      -------------------------------
      -- Process_Delay_Alternative --
      -------------------------------

      procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int) is
         Dloc      : constant Source_Ptr := Sloc (Delay_Statement (Alt));
         Cond      : Node_Id;
         Delay_Alt : List_Id;

      begin
         --  Deal with C/Fortran boolean as delay condition

         Adjust_Condition (Condition (Alt));

         --  Determine the smallest specified delay

         --  for each delay alternative generate:

         --    if guard-expression then
         --       Delay_Val  := delay-expression;
         --       Guard_Open := True;
         --       if Delay_Val < Delay_Min then
         --          Delay_Min   := Delay_Val;
         --          Delay_Index := Index;
         --       end if;
         --    end if;

         --  The enclosing if-statement is omitted if there is no guard

         if Delay_Count = 1 or else First_Delay then
            First_Delay := False;

            Delay_Alt := New_List (
              Make_Assignment_Statement (Loc,
                Name       => New_Occurrence_Of (Delay_Min, Loc),
                Expression => Expression (Delay_Statement (Alt))));

            if Delay_Count > 1 then
               Append_To (Delay_Alt,
                 Make_Assignment_Statement (Loc,
                   Name       => New_Occurrence_Of (Delay_Index, Loc),
                   Expression => Make_Integer_Literal (Loc, Index)));
            end if;

         else
            Delay_Alt := New_List (
              Make_Assignment_Statement (Loc,
                Name       => New_Occurrence_Of (Delay_Val, Loc),
                Expression => Expression (Delay_Statement (Alt))));

            if Time_Type = Standard_Duration then
               Cond :=
                  Make_Op_Lt (Loc,
                    Left_Opnd  => New_Occurrence_Of (Delay_Val, Loc),
                    Right_Opnd => New_Occurrence_Of (Delay_Min, Loc));

            else
               --  The scope of the time type must define a comparison
               --  operator. The scope itself may not be visible, so we
               --  construct a node with entity information to insure that
               --  semantic analysis can find the proper operator.

               Cond :=
                 Make_Function_Call (Loc,
                   Name => Make_Selected_Component (Loc,
                     Prefix        =>
                       New_Occurrence_Of (Scope (Time_Type), Loc),
                     Selector_Name =>
                       Make_Operator_Symbol (Loc,
                         Chars  => Name_Op_Lt,
                         Strval => No_String)),
                    Parameter_Associations =>
                      New_List (
                        New_Occurrence_Of (Delay_Val, Loc),
                        New_Occurrence_Of (Delay_Min, Loc)));

               Set_Entity (Prefix (Name (Cond)), Scope (Time_Type));
            end if;

            Append_To (Delay_Alt,
              Make_Implicit_If_Statement (N,
                Condition => Cond,
                Then_Statements => New_List (
                  Make_Assignment_Statement (Loc,
                    Name       => New_Occurrence_Of (Delay_Min, Loc),
                    Expression => New_Occurrence_Of (Delay_Val, Loc)),

                  Make_Assignment_Statement (Loc,
                    Name       => New_Occurrence_Of (Delay_Index, Loc),
                    Expression => Make_Integer_Literal (Loc, Index)))));
         end if;

         if Check_Guard then
            Append_To (Delay_Alt,
              Make_Assignment_Statement (Loc,
                Name       => New_Occurrence_Of (Guard_Open, Loc),
                Expression => New_Occurrence_Of (Standard_True, Loc)));
         end if;

         if Present (Condition (Alt)) then
            Delay_Alt := New_List (
              Make_Implicit_If_Statement (N,
                Condition       => Condition (Alt),
                Then_Statements => Delay_Alt));
         end if;

         Append_List (Delay_Alt, Delay_List);

         Ensure_Statement_Present (Dloc, Alt);

         --  If the delay alternative has a statement part, add choice to the
         --  case statements for delays.

         if not Is_Empty_List (Statements (Alt)) then

            if Delay_Count = 1 then
               Append_List (Statements (Alt), Delay_Alt_List);

            else
               Append_To (Delay_Alt_List,
                 Make_Case_Statement_Alternative (Loc,
                   Discrete_Choices => New_List (
                                         Make_Integer_Literal (Loc, Index)),
                   Statements       => Statements (Alt)));
            end if;

         elsif Delay_Count = 1 then

            --  If the single delay has no trailing statements, add a branch
            --  to the exit label to the selective wait.

            Delay_Alt_List := New_List (
              Make_Goto_Statement (Loc,
                Name => New_Copy (Identifier (End_Lab))));

         end if;
      end Process_Delay_Alternative;

   --  Start of processing for Expand_N_Selective_Accept

   begin
      Process_Statements_For_Controlled_Objects (N);

      --  First insert some declarations before the select. The first is:

      --    Ann : Address

      --  This variable holds the parameters passed to the accept body. This
      --  declaration has already been inserted by the time we get here by
      --  a call to Expand_Accept_Declarations made from the semantics when
      --  processing the first accept statement contained in the select. We
      --  can find this entity as Accept_Address (E), where E is any of the
      --  entries references by contained accept statements.

      --  The first step is to scan the list of Selective_Accept_Statements
      --  to find this entity, and also count the number of accepts, and
      --  determine if terminated, delay or else is present:

      Num_Alts := 0;

      Alt := First (Alts);
      while Present (Alt) loop
         Process_Statements_For_Controlled_Objects (Alt);

         if Nkind (Alt) = N_Accept_Alternative then
            Add_Accept (Alt);

         elsif Nkind (Alt) = N_Delay_Alternative then
            Delay_Count := Delay_Count + 1;

            --  If the delays are relative delays, the delay expressions have
            --  type Standard_Duration. Otherwise they must have some time type
            --  recognized by GNAT.

            if Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement then
               Time_Type := Standard_Duration;
            else
               Time_Type := Etype (Expression (Delay_Statement (Alt)));

               if Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time)
                 or else Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time)
               then
                  null;
               else
                  Error_Msg_NE (
                    "& is not a time type (RM 9.6(6))",
                       Expression (Delay_Statement (Alt)), Time_Type);
                  Time_Type := Standard_Duration;
                  Set_Etype (Expression (Delay_Statement (Alt)), Any_Type);
               end if;
            end if;

            if No (Condition (Alt)) then

               --  This guard will always be open

               Check_Guard := False;
            end if;

         elsif Nkind (Alt) = N_Terminate_Alternative then
            Adjust_Condition (Condition (Alt));
            Terminate_Alt := Alt;
         end if;

         Num_Alts := Num_Alts + 1;
         Next (Alt);
      end loop;

      Else_Present := Present (Else_Statements (N));

      --  At the same time (see procedure Add_Accept) we build the accept list:

      --    Qnn : Accept_List (1 .. num-select) := (
      --          (null-body, entry-index),
      --          (null-body, entry-index),
      --          ..
      --          (null_body, entry-index));

      --  In the above declaration, null-body is True if the corresponding
      --  accept has no body, and false otherwise. The entry is either the
      --  entry index expression if there is no guard, or if a guard is
      --  present, then an if expression of the form:

      --    (if guard then entry-index else Null_Task_Entry)

      --  If a guard is statically known to be false, the entry can simply
      --  be omitted from the accept list.

      Append_To (Decls,
        Make_Object_Declaration (Loc,
          Defining_Identifier => Qnam,
          Object_Definition   => New_Occurrence_Of (RTE (RE_Accept_List), Loc),
          Aliased_Present     => True,
          Expression          =>
             Make_Qualified_Expression (Loc,
               Subtype_Mark =>
                 New_Occurrence_Of (RTE (RE_Accept_List), Loc),
               Expression   =>
                 Make_Aggregate (Loc, Expressions => Accept_List))));

      --  Then we declare the variable that holds the index for the accept
      --  that will be selected for service:

      --    Xnn : Select_Index;

      Append_To (Decls,
        Make_Object_Declaration (Loc,
          Defining_Identifier => Xnam,
          Object_Definition =>
            New_Occurrence_Of (RTE (RE_Select_Index), Loc),
          Expression =>
            New_Occurrence_Of (RTE (RE_No_Rendezvous), Loc)));

      --  After this follow procedure declarations for each accept body

      --    procedure Pnn is
      --    begin
      --       ...
      --    end;

      --  where the ... are statements from the corresponding procedure body.
      --  No parameters are involved, since the parameters are passed via Ann
      --  and the parameter references have already been expanded to be direct
      --  references to Ann (see Exp_Ch2.Expand_Entry_Parameter). Furthermore,
      --  any embedded tasking statements (which would normally be illegal in
      --  procedures), have been converted to calls to the tasking runtime so
      --  there is no problem in putting them into procedures.

      --  The original accept statement has been expanded into a block in
      --  the same fashion as for simple accepts (see Build_Accept_Body).

      --  Note: we don't really need to build these procedures for the case
      --  where no delay statement is present, but it is just as easy to
      --  build them unconditionally, and not significantly inefficient,
      --  since if they are short they will be inlined anyway.

      --  The procedure declarations have been assembled in Body_List

      --  If delays are present, we must compute the required delay.
      --  We first generate the declarations:

      --    Delay_Index : Boolean := 0;
      --    Delay_Min   : Some_Time_Type.Time;
      --    Delay_Val   : Some_Time_Type.Time;

      --  Delay_Index will be set to the index of the minimum delay, i.e. the
      --  active delay that is actually chosen as the basis for the possible
      --  delay if an immediate rendez-vous is not possible.

      --  In the most common case there is a single delay statement, and this
      --  is handled specially.

      if Delay_Count > 0 then

         --  Generate the required declarations

         Delay_Val :=
           Make_Defining_Identifier (Loc, New_External_Name ('D', 1));
         Delay_Index :=
           Make_Defining_Identifier (Loc, New_External_Name ('D', 2));
         Delay_Min :=
           Make_Defining_Identifier (Loc, New_External_Name ('D', 3));

         Append_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => Delay_Val,
             Object_Definition   => New_Occurrence_Of (Time_Type, Loc)));

         Append_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => Delay_Index,
             Object_Definition   => New_Occurrence_Of (Standard_Integer, Loc),
             Expression          => Make_Integer_Literal (Loc, 0)));

         Append_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => Delay_Min,
             Object_Definition   => New_Occurrence_Of (Time_Type, Loc),
             Expression          =>
               Unchecked_Convert_To (Time_Type,
                 Make_Attribute_Reference (Loc,
                   Prefix =>
                     New_Occurrence_Of (Underlying_Type (Time_Type), Loc),
                   Attribute_Name => Name_Last))));

         --  Create Duration and Delay_Mode objects used for passing a delay
         --  value to RTS

         D := Make_Temporary (Loc, 'D');
         M := Make_Temporary (Loc, 'M');

         declare
            Discr : Entity_Id;

         begin
            --  Note that these values are defined in s-osprim.ads and must
            --  be kept in sync:
            --
            --     Relative          : constant := 0;
            --     Absolute_Calendar : constant := 1;
            --     Absolute_RT       : constant := 2;

            if Time_Type = Standard_Duration then
               Discr := Make_Integer_Literal (Loc, 0);

            elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then
               Discr := Make_Integer_Literal (Loc, 1);

            else
               pragma Assert
                 (Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time));
               Discr := Make_Integer_Literal (Loc, 2);
            end if;

            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Defining_Identifier => D,
                Object_Definition   =>
                  New_Occurrence_Of (Standard_Duration, Loc)));

            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Defining_Identifier => M,
                Object_Definition   =>
                  New_Occurrence_Of (Standard_Integer, Loc),
                Expression          => Discr));
         end;

         if Check_Guard then
            Guard_Open :=
              Make_Defining_Identifier (Loc, New_External_Name ('G', 1));

            Append_To (Decls,
              Make_Object_Declaration (Loc,
                 Defining_Identifier => Guard_Open,
                 Object_Definition   =>
                   New_Occurrence_Of (Standard_Boolean, Loc),
                 Expression          =>
                   New_Occurrence_Of (Standard_False, Loc)));
         end if;

      --  Delay_Count is zero, don't need M and D set (suppress warning)

      else
         M := Empty;
         D := Empty;
      end if;

      if Present (Terminate_Alt) then

         --  If the terminate alternative guard is False, use
         --  Simple_Mode; otherwise use Terminate_Mode.

         if Present (Condition (Terminate_Alt)) then
            Select_Mode := Make_If_Expression (Loc,
              New_List (Condition (Terminate_Alt),
                        New_Occurrence_Of (RTE (RE_Terminate_Mode), Loc),
                        New_Occurrence_Of (RTE (RE_Simple_Mode), Loc)));
         else
            Select_Mode := New_Occurrence_Of (RTE (RE_Terminate_Mode), Loc);
         end if;

      elsif Else_Present or Delay_Count > 0 then
         Select_Mode := New_Occurrence_Of (RTE (RE_Else_Mode), Loc);

      else
         Select_Mode := New_Occurrence_Of (RTE (RE_Simple_Mode), Loc);
      end if;

      Select_Call := Make_Select_Call (Select_Mode);
      Append (Select_Call, Stats);

      --  Now generate code to act on the result. There is an entry
      --  in this case for each accept statement with a non-null body,
      --  followed by a branch to the statements that follow the Accept.
      --  In the absence of delay alternatives, we generate:

      --    case X is
      --      when No_Rendezvous =>  --  omitted if simple mode
      --         goto Lab0;

      --      when 1 =>
      --         P1n;
      --         goto Lab1;

      --      when 2 =>
      --         P2n;
      --         goto Lab2;

      --      when others =>
      --         goto Exit;
      --    end case;
      --
      --    Lab0: Else_Statements;
      --    goto exit;

      --    Lab1:  Trailing_Statements1;
      --    goto Exit;
      --
      --    Lab2:  Trailing_Statements2;
      --    goto Exit;
      --    ...
      --    Exit:

      --  Generate label for common exit

      End_Lab := Make_And_Declare_Label (Num_Alts + 1);

      --  First entry is the default case, when no rendezvous is possible

      Choices := New_List (New_Occurrence_Of (RTE (RE_No_Rendezvous), Loc));

      if Else_Present then

         --  If no rendezvous is possible, the else part is executed

         Lab := Make_And_Declare_Label (0);
         Alt_Stats := New_List (
           Make_Goto_Statement (Loc,
             Name => New_Copy (Identifier (Lab))));

         Append (Lab, Trailing_List);
         Append_List (Else_Statements (N), Trailing_List);
         Append_To (Trailing_List,
           Make_Goto_Statement (Loc,
             Name => New_Copy (Identifier (End_Lab))));
      else
         Alt_Stats := New_List (
           Make_Goto_Statement (Loc,
             Name => New_Copy (Identifier (End_Lab))));
      end if;

      Append_To (Alt_List,
        Make_Case_Statement_Alternative (Loc,
          Discrete_Choices => Choices,
          Statements       => Alt_Stats));

      --  We make use of the fact that Accept_Index is an integer type, and
      --  generate successive literals for entries for each accept. Only those
      --  for which there is a body or trailing statements get a case entry.

      Alt := First (Select_Alternatives (N));
      Proc := First (Body_List);
      while Present (Alt) loop

         if Nkind (Alt) = N_Accept_Alternative then
            Process_Accept_Alternative (Alt, Index, Proc);
            Index := Index + 1;

            if Present
              (Handled_Statement_Sequence (Accept_Statement (Alt)))
            then
               Next (Proc);
            end if;

         elsif Nkind (Alt) = N_Delay_Alternative then
            Process_Delay_Alternative (Alt, Delay_Num);
            Delay_Num := Delay_Num + 1;
         end if;

         Next (Alt);
      end loop;

      --  An others choice is always added to the main case, as well
      --  as the delay case (to satisfy the compiler).

      Append_To (Alt_List,
        Make_Case_Statement_Alternative (Loc,
          Discrete_Choices =>
            New_List (Make_Others_Choice (Loc)),
          Statements       =>
            New_List (Make_Goto_Statement (Loc,
              Name => New_Copy (Identifier (End_Lab))))));

      Accept_Case := New_List (
        Make_Case_Statement (Loc,
          Expression   => New_Occurrence_Of (Xnam, Loc),
          Alternatives => Alt_List));

      Append_List (Trailing_List, Accept_Case);
      Append_List (Body_List, Decls);

      --  Construct case statement for trailing statements of delay
      --  alternatives, if there are several of them.

      if Delay_Count > 1 then
         Append_To (Delay_Alt_List,
           Make_Case_Statement_Alternative (Loc,
             Discrete_Choices =>
               New_List (Make_Others_Choice (Loc)),
             Statements       =>
               New_List (Make_Null_Statement (Loc))));

         Delay_Case := New_List (
           Make_Case_Statement (Loc,
             Expression   => New_Occurrence_Of (Delay_Index, Loc),
             Alternatives => Delay_Alt_List));
      else
         Delay_Case := Delay_Alt_List;
      end if;

      --  If there are no delay alternatives, we append the case statement
      --  to the statement list.

      if Delay_Count = 0 then
         Append_List (Accept_Case, Stats);

      --  Delay alternatives present

      else
         --  If delay alternatives are present we generate:

         --    find minimum delay.
         --    DX := minimum delay;
         --    M := <delay mode>;
         --    Timed_Selective_Wait (Q'Unchecked_Access, Delay_Mode, P,
         --      DX, MX, X);
         --
         --    if X = No_Rendezvous then
         --      case statement for delay statements.
         --    else
         --      case statement for accept alternatives.
         --    end if;

         declare
            Cases : Node_Id;
            Stmt  : Node_Id;
            Parms : List_Id;
            Parm  : Node_Id;
            Conv  : Node_Id;

         begin
            --  The type of the delay expression is known to be legal

            if Time_Type = Standard_Duration then
               Conv := New_Occurrence_Of (Delay_Min, Loc);

            elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then
               Conv := Make_Function_Call (Loc,
                 New_Occurrence_Of (RTE (RO_CA_To_Duration), Loc),
                 New_List (New_Occurrence_Of (Delay_Min, Loc)));

            else
               pragma Assert
                 (Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time));

               Conv := Make_Function_Call (Loc,
                 New_Occurrence_Of (RTE (RO_RT_To_Duration), Loc),
                 New_List (New_Occurrence_Of (Delay_Min, Loc)));
            end if;

            Stmt := Make_Assignment_Statement (Loc,
              Name       => New_Occurrence_Of (D, Loc),
              Expression => Conv);

            --  Change the value for Accept_Modes. (Else_Mode -> Delay_Mode)

            Parms := Parameter_Associations (Select_Call);

            Parm := First (Parms);
            while Present (Parm) and then Parm /= Select_Mode loop
               Next (Parm);
            end loop;

            pragma Assert (Present (Parm));
            Rewrite (Parm, New_Occurrence_Of (RTE (RE_Delay_Mode), Loc));
            Analyze (Parm);

            --  Prepare two new parameters of Duration and Delay_Mode type
            --  which represent the value and the mode of the minimum delay.

            Next (Parm);
            Insert_After (Parm, New_Occurrence_Of (M, Loc));
            Insert_After (Parm, New_Occurrence_Of (D, Loc));

            --  Create a call to RTS

            Rewrite (Select_Call,
              Make_Procedure_Call_Statement (Loc,
                Name => New_Occurrence_Of (RTE (RE_Timed_Selective_Wait), Loc),
                Parameter_Associations => Parms));

            --  This new call should follow the calculation of the minimum
            --  delay.

            Insert_List_Before (Select_Call, Delay_List);

            if Check_Guard then
               Stmt :=
                 Make_Implicit_If_Statement (N,
                   Condition       => New_Occurrence_Of (Guard_Open, Loc),
                   Then_Statements => New_List (
                     New_Copy_Tree (Stmt),
                     New_Copy_Tree (Select_Call)),
                   Else_Statements => Accept_Or_Raise);
               Rewrite (Select_Call, Stmt);
            else
               Insert_Before (Select_Call, Stmt);
            end if;

            Cases :=
              Make_Implicit_If_Statement (N,
                Condition => Make_Op_Eq (Loc,
                  Left_Opnd  => New_Occurrence_Of (Xnam, Loc),
                  Right_Opnd =>
                    New_Occurrence_Of (RTE (RE_No_Rendezvous), Loc)),

                Then_Statements => Delay_Case,
                Else_Statements => Accept_Case);

            Append (Cases, Stats);
         end;
      end if;

      Append (End_Lab, Stats);

      --  Replace accept statement with appropriate block

      Rewrite (N,
        Make_Block_Statement (Loc,
          Declarations               => Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats)));
      Analyze (N);

      --  Note: have to worry more about abort deferral in above code ???

      --  Final step is to unstack the Accept_Address entries for all accept
      --  statements appearing in accept alternatives in the select statement

      Alt := First (Alts);
      while Present (Alt) loop
         if Nkind (Alt) = N_Accept_Alternative then
            Remove_Last_Elmt (Accept_Address
              (Entity (Entry_Direct_Name (Accept_Statement (Alt)))));
         end if;

         Next (Alt);
      end loop;
   end Expand_N_Selective_Accept;

   -------------------------------------------
   -- Expand_N_Single_Protected_Declaration --
   -------------------------------------------

   --  A single protected declaration should never be present after semantic
   --  analysis because it is transformed into a protected type declaration
   --  and an accompanying anonymous object. This routine ensures that the
   --  transformation takes place.

   procedure Expand_N_Single_Protected_Declaration (N : Node_Id) is
   begin
      raise Program_Error;
   end Expand_N_Single_Protected_Declaration;

   --------------------------------------
   -- Expand_N_Single_Task_Declaration --
   --------------------------------------

   --  A single task declaration should never be present after semantic
   --  analysis because it is transformed into a task type declaration and
   --  an accompanying anonymous object. This routine ensures that the
   --  transformation takes place.

   procedure Expand_N_Single_Task_Declaration (N : Node_Id) is
   begin
      raise Program_Error;
   end Expand_N_Single_Task_Declaration;

   ------------------------
   -- Expand_N_Task_Body --
   ------------------------

   --  Given a task body

   --    task body tname is
   --       <declarations>
   --    begin
   --       <statements>
   --    end x;

   --  This expansion routine converts it into a procedure and sets the
   --  elaboration flag for the procedure to true, to represent the fact
   --  that the task body is now elaborated:

   --    procedure tnameB (_Task : access tnameV) is
   --       discriminal : dtype renames _Task.discriminant;

   --       procedure _clean is
   --       begin
   --          Abort_Defer.all;
   --          Complete_Task;
   --          Abort_Undefer.all;
   --          return;
   --       end _clean;

   --    begin
   --       Abort_Undefer.all;
   --       <declarations>
   --       System.Task_Stages.Complete_Activation;
   --       <statements>
   --    at end
   --       _clean;
   --    end tnameB;

   --    tnameE := True;

   --  In addition, if the task body is an activator, then a call to activate
   --  tasks is added at the start of the statements, before the call to
   --  Complete_Activation, and if in addition the task is a master then it
   --  must be established as a master. These calls are inserted and analyzed
   --  in Expand_Cleanup_Actions, when the Handled_Sequence_Of_Statements is
   --  expanded.

   --  There is one discriminal declaration line generated for each
   --  discriminant that is present to provide an easy reference point for
   --  discriminant references inside the body (see Exp_Ch2.Expand_Name).

   --  Note on relationship to GNARLI definition. In the GNARLI definition,
   --  task body procedures have a profile (Arg : System.Address). That is
   --  needed because GNARLI has to use the same access-to-subprogram type
   --  for all task types. We depend here on knowing that in GNAT, passing
   --  an address argument by value is identical to passing a record value
   --  by access (in either case a single pointer is passed), so even though
   --  this procedure has the wrong profile. In fact it's all OK, since the
   --  callings sequence is identical.

   procedure Expand_N_Task_Body (N : Node_Id) is
      Loc   : constant Source_Ptr := Sloc (N);
      Ttyp  : constant Entity_Id  := Corresponding_Spec (N);
      Call  : Node_Id;
      New_N : Node_Id;

      Insert_Nod : Node_Id;
      --  Used to determine the proper location of wrapper body insertions

   begin
      --  if no task body procedure, means we had an error in configurable
      --  run-time mode, and there is no point in proceeding further.

      if No (Task_Body_Procedure (Ttyp)) then
         return;
      end if;

      --  Add renaming declarations for discriminals and a declaration for the
      --  entry family index (if applicable).

      Install_Private_Data_Declarations
        (Loc, Task_Body_Procedure (Ttyp), Ttyp, N, Declarations (N));

      --  Add a call to Abort_Undefer at the very beginning of the task
      --  body since this body is called with abort still deferred.

      if Abort_Allowed then
         Call := Build_Runtime_Call (Loc, RE_Abort_Undefer);
         Insert_Before
           (First (Statements (Handled_Statement_Sequence (N))), Call);
         Analyze (Call);
      end if;

      --  The statement part has already been protected with an at_end and
      --  cleanup actions. The call to Complete_Activation must be placed
      --  at the head of the sequence of statements of that block. The
      --  declarations have been merged in this sequence of statements but
      --  the first real statement is accessible from the First_Real_Statement
      --  field (which was set for exactly this purpose).

      if Restricted_Profile then
         Call := Build_Runtime_Call (Loc, RE_Complete_Restricted_Activation);
      else
         Call := Build_Runtime_Call (Loc, RE_Complete_Activation);
      end if;

      Insert_Before
        (First_Real_Statement (Handled_Statement_Sequence (N)), Call);
      Analyze (Call);

      New_N :=
        Make_Subprogram_Body (Loc,
          Specification              => Build_Task_Proc_Specification (Ttyp),
          Declarations               => Declarations (N),
          Handled_Statement_Sequence => Handled_Statement_Sequence (N));
      Set_Is_Task_Body_Procedure (New_N);

      --  If the task contains generic instantiations, cleanup actions are
      --  delayed until after instantiation. Transfer the activation chain to
      --  the subprogram, to insure that the activation call is properly
      --  generated. It the task body contains inner tasks, indicate that the
      --  subprogram is a task master.

      if Delay_Cleanups (Ttyp) then
         Set_Activation_Chain_Entity (New_N, Activation_Chain_Entity (N));
         Set_Is_Task_Master  (New_N, Is_Task_Master (N));
      end if;

      Rewrite (N, New_N);
      Analyze (N);

      --  Set elaboration flag immediately after task body. If the body is a
      --  subunit, the flag is set in the declarative part containing the stub.

      if Nkind (Parent (N)) /= N_Subunit then
         Insert_After (N,
           Make_Assignment_Statement (Loc,
             Name =>
               Make_Identifier (Loc, New_External_Name (Chars (Ttyp), 'E')),
             Expression => New_Occurrence_Of (Standard_True, Loc)));
      end if;

      --  Ada 2005 (AI-345): Construct the primitive entry wrapper bodies after
      --  the task body. At this point all wrapper specs have been created,
      --  frozen and included in the dispatch table for the task type.

      if Ada_Version >= Ada_2005 then
         if Nkind (Parent (N)) = N_Subunit then
            Insert_Nod := Corresponding_Stub (Parent (N));
         else
            Insert_Nod := N;
         end if;

         Build_Wrapper_Bodies (Loc, Ttyp, Insert_Nod);
      end if;
   end Expand_N_Task_Body;

   ------------------------------------
   -- Expand_N_Task_Type_Declaration --
   ------------------------------------

   --  We have several things to do. First we must create a Boolean flag used
   --  to mark if the body is elaborated yet. This variable gets set to True
   --  when the body of the task is elaborated (we can't rely on the normal
   --  ABE mechanism for the task body, since we need to pass an access to
   --  this elaboration boolean to the runtime routines).

   --    taskE : aliased Boolean := False;

   --  Next a variable is declared to hold the task stack size (either the
   --  default : Unspecified_Size, or a value that is set by a pragma
   --  Storage_Size). If the value of the pragma Storage_Size is static, then
   --  the variable is initialized with this value:

   --    taskZ : Size_Type := Unspecified_Size;
   --  or
   --    taskZ : Size_Type := Size_Type (size_expression);

   --  Note: No variable is needed to hold the task relative deadline since
   --  its value would never be static because the parameter is of a private
   --  type (Ada.Real_Time.Time_Span).

   --  Next we create a corresponding record type declaration used to represent
   --  values of this task. The general form of this type declaration is

   --    type taskV (discriminants) is record
   --      _Task_Id              : Task_Id;
   --      entry_family          : array (bounds) of Void;
   --      _Priority             : Integer            := priority_expression;
   --      _Size                 : Size_Type          := size_expression;
   --      _Secondary_Stack_Size : Size_Type          := size_expression;
   --      _Task_Info            : Task_Info_Type     := task_info_expression;
   --      _CPU                  : Integer            := cpu_range_expression;
   --      _Relative_Deadline    : Time_Span          := time_span_expression;
   --      _Domain               : Dispatching_Domain := dd_expression;
   --    end record;

   --  The discriminants are present only if the corresponding task type has
   --  discriminants, and they exactly mirror the task type discriminants.

   --  The Id field is always present. It contains the Task_Id value, as set by
   --  the call to Create_Task. Note that although the task is limited, the
   --  task value record type is not limited, so there is no problem in passing
   --  this field as an out parameter to Create_Task.

   --  One entry_family component is present for each entry family in the task
   --  definition. The bounds correspond to the bounds of the entry family
   --  (which may depend on discriminants). The element type is void, since we
   --  only need the bounds information for determining the entry index. Note
   --  that the use of an anonymous array would normally be illegal in this
   --  context, but this is a parser check, and the semantics is quite prepared
   --  to handle such a case.

   --  The _Size field is present only if a Storage_Size pragma appears in the
   --  task definition. The expression captures the argument that was present
   --  in the pragma, and is used to override the task stack size otherwise
   --  associated with the task type.

   --  The _Secondary_Stack_Size field is present only the task entity has a
   --  Secondary_Stack_Size rep item. It will be filled at the freeze point,
   --  when the record init proc is built, to capture the expression of the
   --  rep item (see Build_Record_Init_Proc in Exp_Ch3). Note that it cannot
   --  be filled here since aspect evaluations are delayed till the freeze
   --  point.

   --  The _Priority field is present only if the task entity has a Priority or
   --  Interrupt_Priority rep item (pragma, aspect specification or attribute
   --  definition clause). It will be filled at the freeze point, when the
   --  record init proc is built, to capture the expression of the rep item
   --  (see Build_Record_Init_Proc in Exp_Ch3). Note that it cannot be filled
   --  here since aspect evaluations are delayed till the freeze point.

   --  The _Task_Info field is present only if a Task_Info pragma appears in
   --  the task definition. The expression captures the argument that was
   --  present in the pragma, and is used to provide the Task_Image parameter
   --  to the call to Create_Task.

   --  The _CPU field is present only if the task entity has a CPU rep item
   --  (pragma, aspect specification or attribute definition clause). It will
   --  be filled at the freeze point, when the record init proc is built, to
   --  capture the expression of the rep item (see Build_Record_Init_Proc in
   --  Exp_Ch3). Note that it cannot be filled here since aspect evaluations
   --  are delayed till the freeze point.

   --  The _Relative_Deadline field is present only if a Relative_Deadline
   --  pragma appears in the task definition. The expression captures the
   --  argument that was present in the pragma, and is used to provide the
   --  Relative_Deadline parameter to the call to Create_Task.

   --  The _Domain field is present only if the task entity has a
   --  Dispatching_Domain rep item (pragma, aspect specification or attribute
   --  definition clause). It will be filled at the freeze point, when the
   --  record init proc is built, to capture the expression of the rep item
   --  (see Build_Record_Init_Proc in Exp_Ch3). Note that it cannot be filled
   --  here since aspect evaluations are delayed till the freeze point.

   --  When a task is declared, an instance of the task value record is
   --  created. The elaboration of this declaration creates the correct bounds
   --  for the entry families, and also evaluates the size, priority, and
   --  task_Info expressions if needed. The initialization routine for the task
   --  type itself then calls Create_Task with appropriate parameters to
   --  initialize the value of the Task_Id field.

   --  Note: the address of this record is passed as the "Discriminants"
   --  parameter for Create_Task. Since Create_Task merely passes this onto the
   --  body procedure, it does not matter that it does not quite match the
   --  GNARLI model of what is being passed (the record contains more than just
   --  the discriminants, but the discriminants can be found from the record
   --  value).

   --  The Entity_Id for this created record type is placed in the
   --  Corresponding_Record_Type field of the associated task type entity.

   --  Next we create a procedure specification for the task body procedure:

   --    procedure taskB (_Task : access taskV);

   --  Note that this must come after the record type declaration, since
   --  the spec refers to this type. It turns out that the initialization
   --  procedure for the value type references the task body spec, but that's
   --  fine, since it won't be generated till the freeze point for the type,
   --  which is certainly after the task body spec declaration.

   --  Finally, we set the task index value field of the entry attribute in
   --  the case of a simple entry.

   procedure Expand_N_Task_Type_Declaration (N : Node_Id) is
      Loc     : constant Source_Ptr := Sloc (N);
      TaskId  : constant Entity_Id  := Defining_Identifier (N);
      Tasktyp : constant Entity_Id  := Etype (Defining_Identifier (N));
      Tasknm  : constant Name_Id    := Chars (Tasktyp);
      Taskdef : constant Node_Id    := Task_Definition (N);

      Body_Decl  : Node_Id;
      Cdecls     : List_Id;
      Decl_Stack : Node_Id;
      Elab_Decl  : Node_Id;
      Ent_Stack  : Entity_Id;
      Proc_Spec  : Node_Id;
      Rec_Decl   : Node_Id;
      Rec_Ent    : Entity_Id;
      Size_Decl  : Entity_Id;
      Task_Size  : Node_Id;

      function Get_Relative_Deadline_Pragma (T : Node_Id) return Node_Id;
      --  Searches the task definition T for the first occurrence of the pragma
      --  Relative Deadline. The caller has ensured that the pragma is present
      --  in the task definition. Note that this routine cannot be implemented
      --  with the Rep Item chain mechanism since Relative_Deadline pragmas are
      --  not chained because their expansion into a procedure call statement
      --  would cause a break in the chain.

      ----------------------------------
      -- Get_Relative_Deadline_Pragma --
      ----------------------------------

      function Get_Relative_Deadline_Pragma (T : Node_Id) return Node_Id is
         N : Node_Id;

      begin
         N := First (Visible_Declarations (T));
         while Present (N) loop
            if Nkind (N) = N_Pragma
              and then Pragma_Name (N) = Name_Relative_Deadline
            then
               return N;
            end if;

            Next (N);
         end loop;

         N := First (Private_Declarations (T));
         while Present (N) loop
            if Nkind (N) = N_Pragma
              and then Pragma_Name (N) = Name_Relative_Deadline
            then
               return N;
            end if;

            Next (N);
         end loop;

         raise Program_Error;
      end Get_Relative_Deadline_Pragma;

   --  Start of processing for Expand_N_Task_Type_Declaration

   begin
      --  If already expanded, nothing to do

      if Present (Corresponding_Record_Type (Tasktyp)) then
         return;
      end if;

      --  Here we will do the expansion

      Rec_Decl := Build_Corresponding_Record (N, Tasktyp, Loc);

      Rec_Ent  := Defining_Identifier (Rec_Decl);
      Cdecls   := Component_Items (Component_List
                                     (Type_Definition (Rec_Decl)));

      Qualify_Entity_Names (N);

      --  First create the elaboration variable

      Elab_Decl :=
        Make_Object_Declaration (Loc,
          Defining_Identifier =>
            Make_Defining_Identifier (Sloc (Tasktyp),
              Chars => New_External_Name (Tasknm, 'E')),
          Aliased_Present      => True,
          Object_Definition    => New_Occurrence_Of (Standard_Boolean, Loc),
          Expression           => New_Occurrence_Of (Standard_False, Loc));

      Insert_After (N, Elab_Decl);

      --  Next create the declaration of the size variable (tasknmZ)

      Set_Storage_Size_Variable (Tasktyp,
        Make_Defining_Identifier (Sloc (Tasktyp),
          Chars => New_External_Name (Tasknm, 'Z')));

      if Present (Taskdef)
        and then Has_Storage_Size_Pragma (Taskdef)
        and then
          Is_OK_Static_Expression
            (Expression
               (First (Pragma_Argument_Associations
                         (Get_Rep_Pragma (TaskId, Name_Storage_Size)))))
      then
         Size_Decl :=
           Make_Object_Declaration (Loc,
             Defining_Identifier => Storage_Size_Variable (Tasktyp),
             Object_Definition   =>
               New_Occurrence_Of (RTE (RE_Size_Type), Loc),
             Expression          =>
               Convert_To (RTE (RE_Size_Type),
                 Relocate_Node
                   (Expression (First (Pragma_Argument_Associations
                                         (Get_Rep_Pragma
                                            (TaskId, Name_Storage_Size)))))));

      else
         Size_Decl :=
           Make_Object_Declaration (Loc,
             Defining_Identifier => Storage_Size_Variable (Tasktyp),
             Object_Definition   =>
               New_Occurrence_Of (RTE (RE_Size_Type), Loc),
             Expression          =>
               New_Occurrence_Of (RTE (RE_Unspecified_Size), Loc));
      end if;

      Insert_After (Elab_Decl, Size_Decl);

      --  Next build the rest of the corresponding record declaration. This is
      --  done last, since the corresponding record initialization procedure
      --  will reference the previously created entities.

      --  Fill in the component declarations -- first the _Task_Id field

      Append_To (Cdecls,
        Make_Component_Declaration (Loc,
          Defining_Identifier  =>
            Make_Defining_Identifier (Loc, Name_uTask_Id),
          Component_Definition =>
            Make_Component_Definition (Loc,
              Aliased_Present    => False,
              Subtype_Indication => New_Occurrence_Of (RTE (RO_ST_Task_Id),
                                    Loc))));

      --  Declare static ATCB (that is, created by the expander) if we are
      --  using the Restricted run time.

      if Restricted_Profile then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier  =>
               Make_Defining_Identifier (Loc, Name_uATCB),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present     => True,
                 Subtype_Indication  => Make_Subtype_Indication (Loc,
                   Subtype_Mark =>
                     New_Occurrence_Of (RTE (RE_Ada_Task_Control_Block), Loc),

                   Constraint   =>
                     Make_Index_Or_Discriminant_Constraint (Loc,
                       Constraints =>
                         New_List (Make_Integer_Literal (Loc, 0)))))));

      end if;

      --  Declare static stack (that is, created by the expander) if we are
      --  using the Restricted run time on a bare board configuration.

      if Restricted_Profile and then Preallocated_Stacks_On_Target then

         --  First we need to extract the appropriate stack size

         Ent_Stack := Make_Defining_Identifier (Loc, Name_uStack);

         if Present (Taskdef) and then Has_Storage_Size_Pragma (Taskdef) then
            declare
               Expr_N : constant Node_Id :=
                          Expression (First (
                            Pragma_Argument_Associations (
                              Get_Rep_Pragma (TaskId, Name_Storage_Size))));
               Etyp   : constant Entity_Id := Etype (Expr_N);
               P      : constant Node_Id   := Parent (Expr_N);

            begin
               --  The stack is defined inside the corresponding record.
               --  Therefore if the size of the stack is set by means of
               --  a discriminant, we must reference the discriminant of the
               --  corresponding record type.

               if Nkind (Expr_N) in N_Has_Entity
                 and then Present (Discriminal_Link (Entity (Expr_N)))
               then
                  Task_Size :=
                    New_Occurrence_Of
                      (CR_Discriminant (Discriminal_Link (Entity (Expr_N))),
                       Loc);
                  Set_Parent   (Task_Size, P);
                  Set_Etype    (Task_Size, Etyp);
                  Set_Analyzed (Task_Size);

               else
                  Task_Size := Relocate_Node (Expr_N);
               end if;
            end;

         else
            Task_Size :=
              New_Occurrence_Of (RTE (RE_Default_Stack_Size), Loc);
         end if;

         Decl_Stack := Make_Component_Declaration (Loc,
           Defining_Identifier  => Ent_Stack,

           Component_Definition =>
             Make_Component_Definition (Loc,
               Aliased_Present     => True,
               Subtype_Indication  => Make_Subtype_Indication (Loc,
                 Subtype_Mark =>
                   New_Occurrence_Of (RTE (RE_Storage_Array), Loc),

                 Constraint   =>
                   Make_Index_Or_Discriminant_Constraint (Loc,
                     Constraints  => New_List (Make_Range (Loc,
                       Low_Bound  => Make_Integer_Literal (Loc, 1),
                       High_Bound => Convert_To (RTE (RE_Storage_Offset),
                         Task_Size)))))));

         Append_To (Cdecls, Decl_Stack);

         --  The appropriate alignment for the stack is ensured by the run-time
         --  code in charge of task creation.

      end if;

      --  Add components for entry families

      Collect_Entry_Families (Loc, Cdecls, Size_Decl, Tasktyp);

      --  Add the _Priority component if a Interrupt_Priority or Priority rep
      --  item is present.

      if Has_Rep_Item (TaskId, Name_Priority, Check_Parents => False) then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier  =>
               Make_Defining_Identifier (Loc, Name_uPriority),
             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (Standard_Integer, Loc))));
      end if;

      --  Add the _Size component if a Storage_Size pragma is present

      if Present (Taskdef) and then Has_Storage_Size_Pragma (Taskdef) then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Loc, Name_uSize),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (RTE (RE_Size_Type), Loc)),

             Expression =>
               Convert_To (RTE (RE_Size_Type),
                 Relocate_Node (
                   Expression (First (
                     Pragma_Argument_Associations (
                       Get_Rep_Pragma (TaskId, Name_Storage_Size))))))));
      end if;

      --  Add the _Secondary_Stack_Size component if a
      --  Secondary_Stack_Size rep item is present.

      if Has_Rep_Item (TaskId, Name_Secondary_Stack_Size,
                       Check_Parents => False)
      then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Loc, Name_uSecondary_Stack_Size),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (RTE (RE_Size_Type), Loc))));
      end if;

      --  Add the _Task_Info component if a Task_Info pragma is present

      if Has_Rep_Pragma (TaskId, Name_Task_Info, Check_Parents => False) then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Loc, Name_uTask_Info),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (RTE (RE_Task_Info_Type), Loc)),

             Expression => New_Copy (
               Expression (First (
                 Pragma_Argument_Associations (
                   Get_Rep_Pragma
                     (TaskId, Name_Task_Info, Check_Parents => False)))))));
      end if;

      --  Add the _CPU component if a CPU rep item is present

      if Has_Rep_Item (TaskId, Name_CPU, Check_Parents => False) then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Loc, Name_uCPU),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (RTE (RE_CPU_Range), Loc))));
      end if;

      --  Add the _Relative_Deadline component if a Relative_Deadline pragma is
      --  present. If we are using a restricted run time this component will
      --  not be added (deadlines are not allowed by the Ravenscar profile).

      if not Restricted_Profile
        and then Present (Taskdef)
        and then Has_Relative_Deadline_Pragma (Taskdef)
      then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier =>
               Make_Defining_Identifier (Loc, Name_uRelative_Deadline),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of (RTE (RE_Time_Span), Loc)),

             Expression =>
               Convert_To (RTE (RE_Time_Span),
                 Relocate_Node (
                   Expression (First (
                     Pragma_Argument_Associations (
                       Get_Relative_Deadline_Pragma (Taskdef))))))));
      end if;

      --  Add the _Dispatching_Domain component if a Dispatching_Domain rep
      --  item is present. If we are using a restricted run time this component
      --  will not be added (dispatching domains are not allowed by the
      --  Ravenscar profile).

      if not Restricted_Profile
        and then
          Has_Rep_Item
            (TaskId, Name_Dispatching_Domain, Check_Parents => False)
      then
         Append_To (Cdecls,
           Make_Component_Declaration (Loc,
             Defining_Identifier  =>
               Make_Defining_Identifier (Loc, Name_uDispatching_Domain),

             Component_Definition =>
               Make_Component_Definition (Loc,
                 Aliased_Present    => False,
                 Subtype_Indication =>
                   New_Occurrence_Of
                     (RTE (RE_Dispatching_Domain_Access), Loc))));
      end if;

      Insert_After (Size_Decl, Rec_Decl);

      --  Analyze the record declaration immediately after construction,
      --  because the initialization procedure is needed for single task
      --  declarations before the next entity is analyzed.

      Analyze (Rec_Decl);

      --  Create the declaration of the task body procedure

      Proc_Spec := Build_Task_Proc_Specification (Tasktyp);
      Body_Decl :=
        Make_Subprogram_Declaration (Loc,
          Specification => Proc_Spec);
      Set_Is_Task_Body_Procedure (Body_Decl);

      Insert_After (Rec_Decl, Body_Decl);

      --  The subprogram does not comes from source, so we have to indicate the
      --  need for debugging information explicitly.

      if Comes_From_Source (Original_Node (N)) then
         Set_Debug_Info_Needed (Defining_Entity (Proc_Spec));
      end if;

      --  Ada 2005 (AI-345): Construct the primitive entry wrapper specs before
      --  the corresponding record has been frozen.

      if Ada_Version >= Ada_2005 then
         Build_Wrapper_Specs (Loc, Tasktyp, Rec_Decl);
      end if;

      --  Ada 2005 (AI-345): We must defer freezing to allow further
      --  declaration of primitive subprograms covering task interfaces

      if Ada_Version <= Ada_95 then

         --  Now we can freeze the corresponding record. This needs manually
         --  freezing, since it is really part of the task type, and the task
         --  type is frozen at this stage. We of course need the initialization
         --  procedure for this corresponding record type and we won't get it
         --  in time if we don't freeze now.

         declare
            L : constant List_Id := Freeze_Entity (Rec_Ent, N);
         begin
            if Is_Non_Empty_List (L) then
               Insert_List_After (Body_Decl, L);
            end if;
         end;
      end if;

      --  Complete the expansion of access types to the current task type, if
      --  any were declared.

      Expand_Previous_Access_Type (Tasktyp);

      --  Create wrappers for entries that have contract cases, preconditions
      --  and postconditions.

      declare
         Ent : Entity_Id;

      begin
         Ent := First_Entity (Tasktyp);
         while Present (Ent) loop
            if Ekind_In (Ent, E_Entry, E_Entry_Family) then
               Build_Contract_Wrapper (Ent, N);
            end if;

            Next_Entity (Ent);
         end loop;
      end;
   end Expand_N_Task_Type_Declaration;

   -------------------------------
   -- Expand_N_Timed_Entry_Call --
   -------------------------------

   --  A timed entry call in normal case is not implemented using ATC mechanism
   --  anymore for efficiency reason.

   --     select
   --        T.E;
   --        S1;
   --     or
   --        delay D;
   --        S2;
   --     end select;

   --  is expanded as follows:

   --  1) When T.E is a task entry_call;

   --    declare
   --       B  : Boolean;
   --       X  : Task_Entry_Index := <entry index>;
   --       DX : Duration := To_Duration (D);
   --       M  : Delay_Mode := <discriminant>;
   --       P  : parms := (parm, parm, parm);

   --    begin
   --       Timed_Protected_Entry_Call
   --         (<acceptor-task>, X, P'Address, DX, M, B);
   --       if B then
   --          S1;
   --       else
   --          S2;
   --       end if;
   --    end;

   --  2) When T.E is a protected entry_call;

   --    declare
   --       B  : Boolean;
   --       X  : Protected_Entry_Index := <entry index>;
   --       DX : Duration := To_Duration (D);
   --       M  : Delay_Mode := <discriminant>;
   --       P  : parms := (parm, parm, parm);

   --    begin
   --       Timed_Protected_Entry_Call
   --         (<object>'unchecked_access, X, P'Address, DX, M, B);
   --       if B then
   --          S1;
   --       else
   --          S2;
   --       end if;
   --    end;

   --  3) Ada 2005 (AI-345): When T.E is a dispatching procedure call, there
   --     is no delay and the triggering statements are executed. We first
   --     determine the kind of the triggering call and then execute a
   --     synchronized operation or a direct call.

   --    declare
   --       B  : Boolean := False;
   --       C  : Ada.Tags.Prim_Op_Kind;
   --       DX : Duration := To_Duration (D)
   --       K  : Ada.Tags.Tagged_Kind :=
   --              Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag (<object>));
   --       M  : Integer :=...;
   --       P  : Parameters := (Param1 .. ParamN);
   --       S  : Integer;

   --    begin
   --       if K = Ada.Tags.TK_Limited_Tagged
   --         or else K = Ada.Tags.TK_Tagged
   --       then
   --          <dispatching-call>;
   --          B := True;

   --       else
   --          S :=
   --            Ada.Tags.Get_Offset_Index
   --              (Ada.Tags.Tag (<object>), DT_Position (<dispatching-call>));

   --          _Disp_Timed_Select (<object>, S, P'Address, DX, M, C, B);

   --          if C = POK_Protected_Entry
   --            or else C = POK_Task_Entry
   --          then
   --             Param1 := P.Param1;
   --             ...
   --             ParamN := P.ParamN;
   --          end if;

   --          if B then
   --             if C = POK_Procedure
   --               or else C = POK_Protected_Procedure
   --               or else C = POK_Task_Procedure
   --             then
   --                <dispatching-call>;
   --             end if;
   --         end if;
   --       end if;

   --      if B then
   --          <triggering-statements>
   --      else
   --          <timed-statements>
   --      end if;
   --    end;

   --  The triggering statement and the sequence of timed statements have not
   --  been analyzed yet (see Analyzed_Timed_Entry_Call), but they may contain
   --  global references if within an instantiation.

   procedure Expand_N_Timed_Entry_Call (N : Node_Id) is
      Loc : constant Source_Ptr := Sloc (N);

      Actuals        : List_Id;
      Blk_Typ        : Entity_Id;
      Call           : Node_Id;
      Call_Ent       : Entity_Id;
      Conc_Typ_Stmts : List_Id;
      Concval        : Node_Id;
      D_Alt          : constant Node_Id := Delay_Alternative (N);
      D_Conv         : Node_Id;
      D_Disc         : Node_Id;
      D_Stat         : Node_Id          := Delay_Statement (D_Alt);
      D_Stats        : List_Id;
      D_Type         : Entity_Id;
      Decls          : List_Id;
      Dummy          : Node_Id;
      E_Alt          : constant Node_Id := Entry_Call_Alternative (N);
      E_Call         : Node_Id          := Entry_Call_Statement (E_Alt);
      E_Stats        : List_Id;
      Ename          : Node_Id;
      Formals        : List_Id;
      Index          : Node_Id;
      Is_Disp_Select : Boolean;
      Lim_Typ_Stmts  : List_Id;
      N_Stats        : List_Id;
      Obj            : Entity_Id;
      Param          : Node_Id;
      Params         : List_Id;
      Stmt           : Node_Id;
      Stmts          : List_Id;
      Unpack         : List_Id;

      B : Entity_Id;  --  Call status flag
      C : Entity_Id;  --  Call kind
      D : Entity_Id;  --  Delay
      K : Entity_Id;  --  Tagged kind
      M : Entity_Id;  --  Delay mode
      P : Entity_Id;  --  Parameter block
      S : Entity_Id;  --  Primitive operation slot

   --  Start of processing for Expand_N_Timed_Entry_Call

   begin
      --  Under the Ravenscar profile, timed entry calls are excluded. An error
      --  was already reported on spec, so do not attempt to expand the call.

      if Restriction_Active (No_Select_Statements) then
         return;
      end if;

      Process_Statements_For_Controlled_Objects (E_Alt);
      Process_Statements_For_Controlled_Objects (D_Alt);

      Ensure_Statement_Present (Sloc (D_Stat), D_Alt);

      --  Retrieve E_Stats and D_Stats now because the finalization machinery
      --  may wrap them in blocks.

      E_Stats := Statements (E_Alt);
      D_Stats := Statements (D_Alt);

      --  The arguments in the call may require dynamic allocation, and the
      --  call statement may have been transformed into a block. The block
      --  may contain additional declarations for internal entities, and the
      --  original call is found by sequential search.

      if Nkind (E_Call) = N_Block_Statement then
         E_Call := First (Statements (Handled_Statement_Sequence (E_Call)));
         while not Nkind_In (E_Call, N_Procedure_Call_Statement,
                                     N_Entry_Call_Statement)
         loop
            Next (E_Call);
         end loop;
      end if;

      Is_Disp_Select :=
        Ada_Version >= Ada_2005
          and then Nkind (E_Call) = N_Procedure_Call_Statement;

      if Is_Disp_Select then
         Extract_Dispatching_Call (E_Call, Call_Ent, Obj, Actuals, Formals);
         Decls := New_List;

         Stmts := New_List;

         --  Generate:
         --    B : Boolean := False;

         B := Build_B (Loc, Decls);

         --  Generate:
         --    C : Ada.Tags.Prim_Op_Kind;

         C := Build_C (Loc, Decls);

         --  Because the analysis of all statements was disabled, manually
         --  analyze the delay statement.

         Analyze (D_Stat);
         D_Stat := Original_Node (D_Stat);

      else
         --  Build an entry call using Simple_Entry_Call

         Extract_Entry (E_Call, Concval, Ename, Index);
         Build_Simple_Entry_Call (E_Call, Concval, Ename, Index);

         Decls := Declarations (E_Call);
         Stmts := Statements (Handled_Statement_Sequence (E_Call));

         if No (Decls) then
            Decls := New_List;
         end if;

         --  Generate:
         --    B : Boolean;

         B := Make_Defining_Identifier (Loc, Name_uB);

         Prepend_To (Decls,
           Make_Object_Declaration (Loc,
             Defining_Identifier => B,
             Object_Definition   =>
               New_Occurrence_Of (Standard_Boolean, Loc)));
      end if;

      --  Duration and mode processing

      D_Type := Base_Type (Etype (Expression (D_Stat)));

      --  Use the type of the delay expression (Calendar or Real_Time) to
      --  generate the appropriate conversion.

      if Nkind (D_Stat) = N_Delay_Relative_Statement then
         D_Disc := Make_Integer_Literal (Loc, 0);
         D_Conv := Relocate_Node (Expression (D_Stat));

      elsif Is_RTE (D_Type, RO_CA_Time) then
         D_Disc := Make_Integer_Literal (Loc, 1);
         D_Conv :=
           Make_Function_Call (Loc,
             Name => New_Occurrence_Of (RTE (RO_CA_To_Duration), Loc),
             Parameter_Associations =>
               New_List (New_Copy (Expression (D_Stat))));

      else pragma Assert (Is_RTE (D_Type, RO_RT_Time));
         D_Disc := Make_Integer_Literal (Loc, 2);
         D_Conv :=
           Make_Function_Call (Loc,
             Name => New_Occurrence_Of (RTE (RO_RT_To_Duration), Loc),
             Parameter_Associations =>
               New_List (New_Copy (Expression (D_Stat))));
      end if;

      D := Make_Temporary (Loc, 'D');

      --  Generate:
      --    D : Duration;

      Append_To (Decls,
        Make_Object_Declaration (Loc,
          Defining_Identifier => D,
          Object_Definition   => New_Occurrence_Of (Standard_Duration, Loc)));

      M := Make_Temporary (Loc, 'M');

      --  Generate:
      --    M : Integer := (0 | 1 | 2);

      Append_To (Decls,
        Make_Object_Declaration (Loc,
          Defining_Identifier => M,
          Object_Definition   => New_Occurrence_Of (Standard_Integer, Loc),
          Expression          => D_Disc));

      --  Do the assignment at this stage only because the evaluation of the
      --  expression must not occur before (see ACVC C97302A).

      Append_To (Stmts,
        Make_Assignment_Statement (Loc,
          Name       => New_Occurrence_Of (D, Loc),
          Expression => D_Conv));

      --  Parameter block processing

      --  Manually create the parameter block for dispatching calls. In the
      --  case of entries, the block has already been created during the call
      --  to Build_Simple_Entry_Call.

      if Is_Disp_Select then

         --  Tagged kind processing, generate:
         --    K : Ada.Tags.Tagged_Kind :=
         --          Ada.Tags.Get_Tagged_Kind (Ada.Tags.Tag <object>));

         K := Build_K (Loc, Decls, Obj);

         Blk_Typ := Build_Parameter_Block (Loc, Actuals, Formals, Decls);
         P :=
           Parameter_Block_Pack (Loc, Blk_Typ, Actuals, Formals, Decls, Stmts);

         --  Dispatch table slot processing, generate:
         --    S : Integer;

         S := Build_S (Loc, Decls);

         --  Generate:
         --    S := Ada.Tags.Get_Offset_Index
         --           (Ada.Tags.Tag (<object>), DT_Position (Call_Ent));

         Conc_Typ_Stmts :=
           New_List (Build_S_Assignment (Loc, S, Obj, Call_Ent));

         --  Generate:
         --    _Disp_Timed_Select (<object>, S, P'Address, D, M, C, B);

         --  where Obj is the controlling formal parameter, S is the dispatch
         --  table slot number of the dispatching operation, P is the wrapped
         --  parameter block, D is the duration, M is the duration mode, C is
         --  the call kind and B is the call status.

         Params := New_List;

         Append_To (Params, New_Copy_Tree (Obj));
         Append_To (Params, New_Occurrence_Of (S, Loc));
         Append_To (Params,
           Make_Attribute_Reference (Loc,
             Prefix         => New_Occurrence_Of (P, Loc),
             Attribute_Name => Name_Address));
         Append_To (Params, New_Occurrence_Of (D, Loc));
         Append_To (Params, New_Occurrence_Of (M, Loc));
         Append_To (Params, New_Occurrence_Of (C, Loc));
         Append_To (Params, New_Occurrence_Of (B, Loc));

         Append_To (Conc_Typ_Stmts,
           Make_Procedure_Call_Statement (Loc,
             Name =>
               New_Occurrence_Of
                 (Find_Prim_Op
                   (Etype (Etype (Obj)), Name_uDisp_Timed_Select), Loc),
             Parameter_Associations => Params));

         --  Generate:
         --    if C = POK_Protected_Entry
         --      or else C = POK_Task_Entry
         --    then
         --       Param1 := P.Param1;
         --       ...
         --       ParamN := P.ParamN;
         --    end if;

         Unpack := Parameter_Block_Unpack (Loc, P, Actuals, Formals);

         --  Generate the if statement only when the packed parameters need
         --  explicit assignments to their corresponding actuals.

         if Present (Unpack) then
            Append_To (Conc_Typ_Stmts,
              Make_Implicit_If_Statement (N,

                Condition       =>
                  Make_Or_Else (Loc,
                    Left_Opnd  =>
                      Make_Op_Eq (Loc,
                        Left_Opnd => New_Occurrence_Of (C, Loc),
                        Right_Opnd =>
                          New_Occurrence_Of
                            (RTE (RE_POK_Protected_Entry), Loc)),

                    Right_Opnd =>
                      Make_Op_Eq (Loc,
                        Left_Opnd  => New_Occurrence_Of (C, Loc),
                        Right_Opnd =>
                          New_Occurrence_Of (RTE (RE_POK_Task_Entry), Loc))),

                Then_Statements => Unpack));
         end if;

         --  Generate:

         --    if B then
         --       if C = POK_Procedure
         --         or else C = POK_Protected_Procedure
         --         or else C = POK_Task_Procedure
         --       then
         --          <dispatching-call>
         --       end if;
         --    end if;

         N_Stats := New_List (
           Make_Implicit_If_Statement (N,
             Condition =>
               Make_Or_Else (Loc,
                 Left_Opnd =>
                   Make_Op_Eq (Loc,
                     Left_Opnd  => New_Occurrence_Of (C, Loc),
                     Right_Opnd =>
                       New_Occurrence_Of (RTE (RE_POK_Procedure), Loc)),

                 Right_Opnd =>
                   Make_Or_Else (Loc,
                     Left_Opnd =>
                       Make_Op_Eq (Loc,
                         Left_Opnd  => New_Occurrence_Of (C, Loc),
                         Right_Opnd =>
                           New_Occurrence_Of (RTE (
                             RE_POK_Protected_Procedure), Loc)),
                     Right_Opnd =>
                       Make_Op_Eq (Loc,
                         Left_Opnd  => New_Occurrence_Of (C, Loc),
                         Right_Opnd =>
                           New_Occurrence_Of
                             (RTE (RE_POK_Task_Procedure), Loc)))),

             Then_Statements => New_List (E_Call)));

         Append_To (Conc_Typ_Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => New_Occurrence_Of (B, Loc),
             Then_Statements => N_Stats));

         --  Generate:
         --    <dispatching-call>;
         --    B := True;

         Lim_Typ_Stmts :=
           New_List (New_Copy_Tree (E_Call),
             Make_Assignment_Statement (Loc,
               Name       => New_Occurrence_Of (B, Loc),
               Expression => New_Occurrence_Of (Standard_True, Loc)));

         --  Generate:
         --    if K = Ada.Tags.TK_Limited_Tagged
         --         or else K = Ada.Tags.TK_Tagged
         --       then
         --       Lim_Typ_Stmts
         --    else
         --       Conc_Typ_Stmts
         --    end if;

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => Build_Dispatching_Tag_Check (K, N),
             Then_Statements => Lim_Typ_Stmts,
             Else_Statements => Conc_Typ_Stmts));

         --    Generate:

         --    if B then
         --       <triggering-statements>
         --    else
         --       <timed-statements>
         --    end if;

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => New_Occurrence_Of (B, Loc),
             Then_Statements => E_Stats,
             Else_Statements => D_Stats));

      else
         --  Simple case of a nondispatching trigger. Skip assignments to
         --  temporaries created for in-out parameters.

         --  This makes unwarranted assumptions about the shape of the expanded
         --  tree for the call, and should be cleaned up ???

         Stmt := First (Stmts);
         while Nkind (Stmt) /= N_Procedure_Call_Statement loop
            Next (Stmt);
         end loop;

         --  Do the assignment at this stage only because the evaluation
         --  of the expression must not occur before (see ACVC C97302A).

         Insert_Before (Stmt,
           Make_Assignment_Statement (Loc,
             Name       => New_Occurrence_Of (D, Loc),
             Expression => D_Conv));

         Call   := Stmt;
         Params := Parameter_Associations (Call);

         --  For a protected type, we build a Timed_Protected_Entry_Call

         if Is_Protected_Type (Etype (Concval)) then

            --  Create a new call statement

            Param := First (Params);
            while Present (Param)
              and then not Is_RTE (Etype (Param), RE_Call_Modes)
            loop
               Next (Param);
            end loop;

            Dummy := Remove_Next (Next (Param));

            --  Remove garbage is following the Cancel_Param if present

            Dummy := Next (Param);

            --  Remove the mode of the Protected_Entry_Call call, then remove
            --  the Communication_Block of the Protected_Entry_Call call, and
            --  finally add Duration and a Delay_Mode parameter

            pragma Assert (Present (Param));
            Rewrite (Param, New_Occurrence_Of (D, Loc));

            Rewrite (Dummy, New_Occurrence_Of (M, Loc));

            --  Add a Boolean flag for successful entry call

            Append_To (Params, New_Occurrence_Of (B, Loc));

            case Corresponding_Runtime_Package (Etype (Concval)) is
               when System_Tasking_Protected_Objects_Entries =>
                  Rewrite (Call,
                    Make_Procedure_Call_Statement (Loc,
                      Name =>
                        New_Occurrence_Of
                          (RTE (RE_Timed_Protected_Entry_Call), Loc),
                      Parameter_Associations => Params));

               when others =>
                  raise Program_Error;
            end case;

         --  For the task case, build a Timed_Task_Entry_Call

         else
            --  Create a new call statement

            Append_To (Params, New_Occurrence_Of (D, Loc));
            Append_To (Params, New_Occurrence_Of (M, Loc));
            Append_To (Params, New_Occurrence_Of (B, Loc));

            Rewrite (Call,
              Make_Procedure_Call_Statement (Loc,
                Name =>
                  New_Occurrence_Of (RTE (RE_Timed_Task_Entry_Call), Loc),
                Parameter_Associations => Params));
         end if;

         Append_To (Stmts,
           Make_Implicit_If_Statement (N,
             Condition       => New_Occurrence_Of (B, Loc),
             Then_Statements => E_Stats,
             Else_Statements => D_Stats));
      end if;

      Rewrite (N,
        Make_Block_Statement (Loc,
          Declarations               => Decls,
          Handled_Statement_Sequence =>
            Make_Handled_Sequence_Of_Statements (Loc, Stmts)));

      Analyze (N);
   end Expand_N_Timed_Entry_Call;

   ----------------------------------------
   -- Expand_Protected_Body_Declarations --
   ----------------------------------------

   procedure Expand_Protected_Body_Declarations
     (N       : Node_Id;
      Spec_Id : Entity_Id)
   is
   begin
      if No_Run_Time_Mode then
         Error_Msg_CRT ("protected body", N);
         return;

      elsif Expander_Active then

         --  Associate discriminals with the first subprogram or entry body to
         --  be expanded.

         if Present (First_Protected_Operation (Declarations (N))) then
            Set_Discriminals (Parent (Spec_Id));
         end if;
      end if;
   end Expand_Protected_Body_Declarations;

   -------------------------
   -- External_Subprogram --
   -------------------------

   function External_Subprogram (E : Entity_Id) return Entity_Id is
      Subp : constant Entity_Id := Protected_Body_Subprogram (E);

   begin
      --  The internal and external subprograms follow each other on the entity
      --  chain. Note that previously private operations had no separate
      --  external subprogram. We now create one in all cases, because a
      --  private operation may actually appear in an external call, through
      --  a 'Access reference used for a callback.

      --  If the operation is a function that returns an anonymous access type,
      --  the corresponding itype appears before the operation, and must be
      --  skipped.

      --  This mechanism is fragile, there should be a real link between the
      --  two versions of the operation, but there is no place to put it ???

      if Is_Access_Type (Next_Entity (Subp)) then
         return Next_Entity (Next_Entity (Subp));
      else
         return Next_Entity (Subp);
      end if;
   end External_Subprogram;

   ------------------------------
   -- Extract_Dispatching_Call --
   ------------------------------

   procedure Extract_Dispatching_Call
     (N        : Node_Id;
      Call_Ent : out Entity_Id;
      Object   : out Entity_Id;
      Actuals  : out List_Id;
      Formals  : out List_Id)
   is
      Call_Nam : Node_Id;

   begin
      pragma Assert (Nkind (N) = N_Procedure_Call_Statement);

      if Present (Original_Node (N)) then
         Call_Nam := Name (Original_Node (N));
      else
         Call_Nam := Name (N);
      end if;

      --  Retrieve the name of the dispatching procedure. It contains the
      --  dispatch table slot number.

      loop
         case Nkind (Call_Nam) is
            when N_Identifier =>
               exit;

            when N_Selected_Component =>
               Call_Nam := Selector_Name (Call_Nam);

            when others =>
               raise Program_Error;

         end case;
      end loop;

      Actuals  := Parameter_Associations (N);
      Call_Ent := Entity (Call_Nam);
      Formals  := Parameter_Specifications (Parent (Call_Ent));
      Object   := First (Actuals);

      if Present (Original_Node (Object)) then
         Object := Original_Node (Object);
      end if;

      --  If the type of the dispatching object is an access type then return
      --  an explicit dereference.

      if Is_Access_Type (Etype (Object)) then
         Object := Make_Explicit_Dereference (Sloc (N), Object);
         Analyze (Object);
      end if;
   end Extract_Dispatching_Call;

   -------------------
   -- Extract_Entry --
   -------------------

   procedure Extract_Entry
     (N       : Node_Id;
      Concval : out Node_Id;
      Ename   : out Node_Id;
      Index   : out Node_Id)
   is
      Nam : constant Node_Id := Name (N);

   begin
      --  For a simple entry, the name is a selected component, with the
      --  prefix being the task value, and the selector being the entry.

      if Nkind (Nam) = N_Selected_Component then
         Concval := Prefix (Nam);
         Ename   := Selector_Name (Nam);
         Index   := Empty;

      --  For a member of an entry family, the name is an indexed component
      --  where the prefix is a selected component, whose prefix in turn is
      --  the task value, and whose selector is the entry family. The single
      --  expression in the expressions list of the indexed component is the
      --  subscript for the family.

      else pragma Assert (Nkind (Nam) = N_Indexed_Component);
         Concval := Prefix (Prefix (Nam));
         Ename   := Selector_Name (Prefix (Nam));
         Index   := First (Expressions (Nam));
      end if;

      --  Through indirection, the type may actually be a limited view of a
      --  concurrent type. When compiling a call, the non-limited view of the
      --  type is visible.

      if From_Limited_With (Etype (Concval)) then
         Set_Etype (Concval, Non_Limited_View (Etype (Concval)));
      end if;
   end Extract_Entry;

   -------------------
   -- Family_Offset --
   -------------------

   function Family_Offset
     (Loc  : Source_Ptr;
      Hi   : Node_Id;
      Lo   : Node_Id;
      Ttyp : Entity_Id;
      Cap  : Boolean) return Node_Id
   is
      Ityp : Entity_Id;
      Real_Hi : Node_Id;
      Real_Lo : Node_Id;

      function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id;
      --  If one of the bounds is a reference to a discriminant, replace with
      --  corresponding discriminal of type. Within the body of a task retrieve
      --  the renamed discriminant by simple visibility, using its generated
      --  name. Within a protected object, find the original discriminant and
      --  replace it with the discriminal of the current protected operation.

      ------------------------------
      -- Convert_Discriminant_Ref --
      ------------------------------

      function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is
         Loc : constant Source_Ptr := Sloc (Bound);
         B   : Node_Id;
         D   : Entity_Id;

      begin
         if Is_Entity_Name (Bound)
           and then Ekind (Entity (Bound)) = E_Discriminant
         then
            if Is_Task_Type (Ttyp) and then Has_Completion (Ttyp) then
               B := Make_Identifier (Loc, Chars (Entity (Bound)));
               Find_Direct_Name (B);

            elsif Is_Protected_Type (Ttyp) then
               D := First_Discriminant (Ttyp);
               while Chars (D) /= Chars (Entity (Bound)) loop
                  Next_Discriminant (D);
               end loop;

               B := New_Occurrence_Of  (Discriminal (D), Loc);

            else
               B := New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
            end if;

         elsif Nkind (Bound) = N_Attribute_Reference then
            return Bound;

         else
            B := New_Copy_Tree (Bound);
         end if;

         return
           Make_Attribute_Reference (Loc,
             Attribute_Name => Name_Pos,
             Prefix => New_Occurrence_Of (Etype (Bound), Loc),
             Expressions    => New_List (B));
      end Convert_Discriminant_Ref;

   --  Start of processing for Family_Offset

   begin
      Real_Hi := Convert_Discriminant_Ref (Hi);
      Real_Lo := Convert_Discriminant_Ref (Lo);

      if Cap then
         if Is_Task_Type (Ttyp) then
            Ityp := RTE (RE_Task_Entry_Index);
         else
            Ityp := RTE (RE_Protected_Entry_Index);
         end if;

         Real_Hi :=
           Make_Attribute_Reference (Loc,
             Prefix         => New_Occurrence_Of (Ityp, Loc),
             Attribute_Name => Name_Min,
             Expressions    => New_List (
               Real_Hi,
               Make_Integer_Literal (Loc, Entry_Family_Bound - 1)));

         Real_Lo :=
           Make_Attribute_Reference (Loc,
             Prefix         => New_Occurrence_Of (Ityp, Loc),
             Attribute_Name => Name_Max,
             Expressions    => New_List (
               Real_Lo,
               Make_Integer_Literal (Loc, -Entry_Family_Bound)));
      end if;

      return Make_Op_Subtract (Loc, Real_Hi, Real_Lo);
   end Family_Offset;

   -----------------
   -- Family_Size --
   -----------------

   function Family_Size
     (Loc  : Source_Ptr;
      Hi   : Node_Id;
      Lo   : Node_Id;
      Ttyp : Entity_Id;
      Cap  : Boolean) return Node_Id
   is
      Ityp : Entity_Id;

   begin
      if Is_Task_Type (Ttyp) then
         Ityp := RTE (RE_Task_Entry_Index);
      else
         Ityp := RTE (RE_Protected_Entry_Index);
      end if;

      return
        Make_Attribute_Reference (Loc,
          Prefix         => New_Occurrence_Of (Ityp, Loc),
          Attribute_Name => Name_Max,
          Expressions    => New_List (
            Make_Op_Add (Loc,
              Left_Opnd  => Family_Offset (Loc, Hi, Lo, Ttyp, Cap),
              Right_Opnd => Make_Integer_Literal (Loc, 1)),
            Make_Integer_Literal (Loc, 0)));
   end Family_Size;

   ----------------------------
   -- Find_Enclosing_Context --
   ----------------------------

   procedure Find_Enclosing_Context
     (N             : Node_Id;
      Context       : out Node_Id;
      Context_Id    : out Entity_Id;
      Context_Decls : out List_Id)
   is
   begin
      --  Traverse the parent chain looking for an enclosing body, block,
      --  package or return statement.

      Context := Parent (N);
      while Present (Context) loop
         if Nkind_In (Context, N_Entry_Body,
                               N_Extended_Return_Statement,
                               N_Package_Body,
                               N_Package_Declaration,
                               N_Subprogram_Body,
                               N_Task_Body)
         then
            exit;

         --  Do not consider block created to protect a list of statements with
         --  an Abort_Defer / Abort_Undefer_Direct pair.

         elsif Nkind (Context) = N_Block_Statement
           and then not Is_Abort_Block (Context)
         then
            exit;
         end if;

         Context := Parent (Context);
      end loop;

      pragma Assert (Present (Context));

      --  Extract the constituents of the context

      if Nkind (Context) = N_Extended_Return_Statement then
         Context_Decls := Return_Object_Declarations (Context);
         Context_Id    := Return_Statement_Entity (Context);

      --  Package declarations and bodies use a common library-level activation
      --  chain or task master, therefore return the package declaration as the
      --  proper carrier for the appropriate flag.

      elsif Nkind (Context) = N_Package_Body then
         Context_Decls := Declarations (Context);
         Context_Id    := Corresponding_Spec (Context);
         Context       := Parent (Context_Id);

         if Nkind (Context) = N_Defining_Program_Unit_Name then
            Context := Parent (Parent (Context));
         else
            Context := Parent (Context);
         end if;

      elsif Nkind (Context) = N_Package_Declaration then
         Context_Decls := Visible_Declarations (Specification (Context));
         Context_Id    := Defining_Unit_Name (Specification (Context));

         if Nkind (Context_Id) = N_Defining_Program_Unit_Name then
            Context_Id := Defining_Identifier (Context_Id);
         end if;

      else
         if Nkind (Context) = N_Block_Statement then
            Context_Id := Entity (Identifier (Context));

         elsif Nkind (Context) = N_Entry_Body then
            Context_Id := Defining_Identifier (Context);

         elsif Nkind (Context) = N_Subprogram_Body then
            if Present (Corresponding_Spec (Context)) then
               Context_Id := Corresponding_Spec (Context);
            else
               Context_Id := Defining_Unit_Name (Specification (Context));

               if Nkind (Context_Id) = N_Defining_Program_Unit_Name then
                  Context_Id := Defining_Identifier (Context_Id);
               end if;
            end if;

         elsif Nkind (Context) = N_Task_Body then
            Context_Id := Corresponding_Spec (Context);

         else
            raise Program_Error;
         end if;

         Context_Decls := Declarations (Context);
      end if;

      pragma Assert (Present (Context_Id));
      pragma Assert (Present (Context_Decls));
   end Find_Enclosing_Context;

   -----------------------
   -- Find_Master_Scope --
   -----------------------

   function Find_Master_Scope (E : Entity_Id) return Entity_Id is
      S : Entity_Id;

   begin
      --  In Ada 2005, the master is the innermost enclosing scope that is not
      --  transient. If the enclosing block is the rewriting of a call or the
      --  scope is an extended return statement this is valid master. The
      --  master in an extended return is only used within the return, and is
      --  subsequently overwritten in Move_Activation_Chain, but it must exist
      --  now before that overwriting occurs.

      S := Scope (E);

      if Ada_Version >= Ada_2005 then
         while Is_Internal (S) loop
            if Nkind (Parent (S)) = N_Block_Statement
              and then
                Nkind (Original_Node (Parent (S))) = N_Procedure_Call_Statement
            then
               exit;

            elsif Ekind (S) = E_Return_Statement then
               exit;

            else
               S := Scope (S);
            end if;
         end loop;
      end if;

      return S;
   end Find_Master_Scope;

   -------------------------------
   -- First_Protected_Operation --
   -------------------------------

   function First_Protected_Operation (D : List_Id) return Node_Id is
      First_Op : Node_Id;

   begin
      First_Op := First (D);
      while Present (First_Op)
        and then not Nkind_In (First_Op, N_Subprogram_Body, N_Entry_Body)
      loop
         Next (First_Op);
      end loop;

      return First_Op;
   end First_Protected_Operation;

   ---------------------------------------
   -- Install_Private_Data_Declarations --
   ---------------------------------------

   procedure Install_Private_Data_Declarations
     (Loc      : Source_Ptr;
      Spec_Id  : Entity_Id;
      Conc_Typ : Entity_Id;
      Body_Nod : Node_Id;
      Decls    : List_Id;
      Barrier  : Boolean := False;
      Family   : Boolean := False)
   is
      Is_Protected : constant Boolean := Is_Protected_Type (Conc_Typ);
      Decl         : Node_Id;
      Def          : Node_Id;
      Insert_Node  : Node_Id := Empty;
      Obj_Ent      : Entity_Id;

      procedure Add (Decl : Node_Id);
      --  Add a single declaration after Insert_Node. If this is the first
      --  addition, Decl is added to the front of Decls and it becomes the
      --  insertion node.

      function Replace_Bound (Bound : Node_Id) return Node_Id;
      --  The bounds of an entry index may depend on discriminants, create a
      --  reference to the corresponding prival. Otherwise return a duplicate
      --  of the original bound.

      ---------
      -- Add --
      ---------

      procedure Add (Decl : Node_Id) is
      begin
         if No (Insert_Node) then
            Prepend_To (Decls, Decl);
         else
            Insert_After (Insert_Node, Decl);
         end if;

         Insert_Node := Decl;
      end Add;

      --------------------------
      -- Replace_Discriminant --
      --------------------------

      function Replace_Bound (Bound : Node_Id) return Node_Id is
      begin
         if Nkind (Bound) = N_Identifier
           and then Is_Discriminal (Entity (Bound))
         then
            return Make_Identifier (Loc, Chars (Entity (Bound)));
         else
            return Duplicate_Subexpr (Bound);
         end if;
      end Replace_Bound;

   --  Start of processing for Install_Private_Data_Declarations

   begin
      --  Step 1: Retrieve the concurrent object entity. Obj_Ent can denote
      --  formal parameter _O, _object or _task depending on the context.

      Obj_Ent := Concurrent_Object (Spec_Id, Conc_Typ);

      --  Special processing of _O for barrier functions, protected entries
      --  and families.

      if Barrier
        or else
          (Is_Protected
             and then
               (Ekind (Spec_Id) = E_Entry
                  or else Ekind (Spec_Id) = E_Entry_Family))
      then
         declare
            Conc_Rec : constant Entity_Id :=
                         Corresponding_Record_Type (Conc_Typ);
            Typ_Id   : constant Entity_Id :=
                         Make_Defining_Identifier (Loc,
                           New_External_Name (Chars (Conc_Rec), 'P'));
         begin
            --  Generate:
            --    type prot_typVP is access prot_typV;

            Decl :=
              Make_Full_Type_Declaration (Loc,
                Defining_Identifier => Typ_Id,
                Type_Definition     =>
                  Make_Access_To_Object_Definition (Loc,
                    Subtype_Indication =>
                      New_Occurrence_Of (Conc_Rec, Loc)));
            Add (Decl);

            --  Generate:
            --    _object : prot_typVP := prot_typV (_O);

            Decl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier =>
                  Make_Defining_Identifier (Loc, Name_uObject),
                Object_Definition   => New_Occurrence_Of (Typ_Id, Loc),
                Expression          =>
                  Unchecked_Convert_To (Typ_Id,
                    New_Occurrence_Of (Obj_Ent, Loc)));
            Add (Decl);

            --  Set the reference to the concurrent object

            Obj_Ent := Defining_Identifier (Decl);
         end;
      end if;

      --  Step 2: Create the Protection object and build its declaration for
      --  any protected entry (family) of subprogram. Note for the lock-free
      --  implementation, the Protection object is not needed anymore.

      if Is_Protected and then not Uses_Lock_Free (Conc_Typ) then
         declare
            Prot_Ent : constant Entity_Id := Make_Temporary (Loc, 'R');
            Prot_Typ : RE_Id;

         begin
            Set_Protection_Object (Spec_Id, Prot_Ent);

            --  Determine the proper protection type

            if Has_Attach_Handler (Conc_Typ)
              and then not Restricted_Profile
            then
               Prot_Typ := RE_Static_Interrupt_Protection;

            elsif Has_Interrupt_Handler (Conc_Typ)
              and then not Restriction_Active (No_Dynamic_Attachment)
            then
               Prot_Typ := RE_Dynamic_Interrupt_Protection;

            else
               case Corresponding_Runtime_Package (Conc_Typ) is
                  when System_Tasking_Protected_Objects_Entries =>
                     Prot_Typ := RE_Protection_Entries;

                  when System_Tasking_Protected_Objects_Single_Entry =>
                     Prot_Typ := RE_Protection_Entry;

                  when System_Tasking_Protected_Objects =>
                     Prot_Typ := RE_Protection;

                  when others =>
                     raise Program_Error;
               end case;
            end if;

            --  Generate:
            --    conc_typR : protection_typ renames _object._object;

            Decl :=
              Make_Object_Renaming_Declaration (Loc,
                Defining_Identifier => Prot_Ent,
                Subtype_Mark =>
                  New_Occurrence_Of (RTE (Prot_Typ), Loc),
                Name =>
                  Make_Selected_Component (Loc,
                    Prefix        => New_Occurrence_Of (Obj_Ent, Loc),
                    Selector_Name => Make_Identifier (Loc, Name_uObject)));
            Add (Decl);
         end;
      end if;

      --  Step 3: Add discriminant renamings (if any)

      if Has_Discriminants (Conc_Typ) then
         declare
            D : Entity_Id;

         begin
            D := First_Discriminant (Conc_Typ);
            while Present (D) loop

               --  Adjust the source location

               Set_Sloc (Discriminal (D), Loc);

               --  Generate:
               --    discr_name : discr_typ renames _object.discr_name;
               --      or
               --    discr_name : discr_typ renames _task.discr_name;

               Decl :=
                 Make_Object_Renaming_Declaration (Loc,
                   Defining_Identifier => Discriminal (D),
                   Subtype_Mark        => New_Occurrence_Of (Etype (D), Loc),
                   Name                =>
                     Make_Selected_Component (Loc,
                       Prefix        => New_Occurrence_Of (Obj_Ent, Loc),
                       Selector_Name => Make_Identifier (Loc, Chars (D))));
               Add (Decl);

               Next_Discriminant (D);
            end loop;
         end;
      end if;

      --  Step 4: Add private component renamings (if any)

      if Is_Protected then
         Def := Protected_Definition (Parent (Conc_Typ));

         if Present (Private_Declarations (Def)) then
            declare
               Comp    : Node_Id;
               Comp_Id : Entity_Id;
               Decl_Id : Entity_Id;

            begin
               Comp := First (Private_Declarations (Def));
               while Present (Comp) loop
                  if Nkind (Comp) = N_Component_Declaration then
                     Comp_Id := Defining_Identifier (Comp);
                     Decl_Id :=
                       Make_Defining_Identifier (Loc, Chars (Comp_Id));

                     --  Minimal decoration

                     if Ekind (Spec_Id) = E_Function then
                        Set_Ekind (Decl_Id, E_Constant);
                     else
                        Set_Ekind (Decl_Id, E_Variable);
                     end if;

                     Set_Prival      (Comp_Id, Decl_Id);
                     Set_Prival_Link (Decl_Id, Comp_Id);
                     Set_Is_Aliased  (Decl_Id, Is_Aliased (Comp_Id));

                     --  Generate:
                     --    comp_name : comp_typ renames _object.comp_name;

                     Decl :=
                       Make_Object_Renaming_Declaration (Loc,
                         Defining_Identifier => Decl_Id,
                         Subtype_Mark =>
                           New_Occurrence_Of (Etype (Comp_Id), Loc),
                         Name =>
                           Make_Selected_Component (Loc,
                             Prefix =>
                               New_Occurrence_Of (Obj_Ent, Loc),
                             Selector_Name =>
                               Make_Identifier (Loc, Chars (Comp_Id))));
                     Add (Decl);
                  end if;

                  Next (Comp);
               end loop;
            end;
         end if;
      end if;

      --  Step 5: Add the declaration of the entry index and the associated
      --  type for barrier functions and entry families.

      if (Barrier and Family) or else Ekind (Spec_Id) = E_Entry_Family then
         declare
            E         : constant Entity_Id := Index_Object (Spec_Id);
            Index     : constant Entity_Id :=
                          Defining_Identifier
                            (Entry_Index_Specification
                               (Entry_Body_Formal_Part (Body_Nod)));
            Index_Con : constant Entity_Id :=
                          Make_Defining_Identifier (Loc, Chars (Index));
            High      : Node_Id;
            Index_Typ : Entity_Id;
            Low       : Node_Id;

         begin
            --  Minimal decoration

            Set_Ekind                (Index_Con, E_Constant);
            Set_Entry_Index_Constant (Index, Index_Con);
            Set_Discriminal_Link     (Index_Con, Index);

            --  Retrieve the bounds of the entry family

            High := Type_High_Bound (Etype (Index));
            Low  := Type_Low_Bound  (Etype (Index));

            --  In the simple case the entry family is given by a subtype
            --  mark and the index constant has the same type.

            if Is_Entity_Name (Original_Node (
                 Discrete_Subtype_Definition (Parent (Index))))
            then
               Index_Typ := Etype (Index);

            --  Otherwise a new subtype declaration is required

            else
               High := Replace_Bound (High);
               Low  := Replace_Bound (Low);

               Index_Typ := Make_Temporary (Loc, 'J');

               --  Generate:
               --    subtype Jnn is <Etype of Index> range Low .. High;

               Decl :=
                 Make_Subtype_Declaration (Loc,
                   Defining_Identifier => Index_Typ,
                   Subtype_Indication =>
                     Make_Subtype_Indication (Loc,
                       Subtype_Mark =>
                         New_Occurrence_Of (Base_Type (Etype (Index)), Loc),
                       Constraint =>
                         Make_Range_Constraint (Loc,
                           Range_Expression =>
                             Make_Range (Loc, Low, High))));
               Add (Decl);
            end if;

            Set_Etype (Index_Con, Index_Typ);

            --  Create the object which designates the index:
            --    J : constant Jnn :=
            --          Jnn'Val (_E - <index expr> + Jnn'Pos (Jnn'First));
            --
            --  where Jnn is the subtype created above or the original type of
            --  the index, _E is a formal of the protected body subprogram and
            --  <index expr> is the index of the first family member.

            Decl :=
              Make_Object_Declaration (Loc,
                Defining_Identifier => Index_Con,
                Constant_Present => True,
                Object_Definition =>
                  New_Occurrence_Of (Index_Typ, Loc),

                Expression =>
                  Make_Attribute_Reference (Loc,
                    Prefix =>
                      New_Occurrence_Of (Index_Typ, Loc),
                    Attribute_Name => Name_Val,

                    Expressions => New_List (

                      Make_Op_Add (Loc,
                        Left_Opnd =>
                          Make_Op_Subtract (Loc,
                            Left_Opnd  => New_Occurrence_Of (E, Loc),
                            Right_Opnd =>
                              Entry_Index_Expression (Loc,
                                Defining_Identifier (Body_Nod),
                                Empty, Conc_Typ)),

                        Right_Opnd =>
                          Make_Attribute_Reference (Loc,
                            Prefix         =>
                              New_Occurrence_Of (Index_Typ, Loc),
                            Attribute_Name => Name_Pos,
                            Expressions    => New_List (
                              Make_Attribute_Reference (Loc,
                                Prefix         =>
                                  New_Occurrence_Of (Index_Typ, Loc),
                                Attribute_Name => Name_First)))))));
            Add (Decl);
         end;
      end if;
   end Install_Private_Data_Declarations;

   -----------------------
   -- Is_Exception_Safe --
   -----------------------

   function Is_Exception_Safe (Subprogram : Node_Id) return Boolean is

      function Has_Side_Effect (N : Node_Id) return Boolean;
      --  Return True whenever encountering a subprogram call or raise
      --  statement of any kind in the sequence of statements

      ---------------------
      -- Has_Side_Effect --
      ---------------------

      --  What is this doing buried two levels down in exp_ch9. It seems like a
      --  generally useful function, and indeed there may be code duplication
      --  going on here ???

      function Has_Side_Effect (N : Node_Id) return Boolean is
         Stmt : Node_Id;
         Expr : Node_Id;

         function Is_Call_Or_Raise (N : Node_Id) return Boolean;
         --  Indicate whether N is a subprogram call or a raise statement

         ----------------------
         -- Is_Call_Or_Raise --
         ----------------------

         function Is_Call_Or_Raise (N : Node_Id) return Boolean is
         begin
            return Nkind_In (N, N_Procedure_Call_Statement,
                                N_Function_Call,
                                N_Raise_Statement,
                                N_Raise_Constraint_Error,
                                N_Raise_Program_Error,
                                N_Raise_Storage_Error);
         end Is_Call_Or_Raise;

      --  Start of processing for Has_Side_Effect

      begin
         Stmt := N;
         while Present (Stmt) loop
            if Is_Call_Or_Raise (Stmt) then
               return True;
            end if;

            --  An object declaration can also contain a function call or a
            --  raise statement.

            if Nkind (Stmt) = N_Object_Declaration then
               Expr := Expression (Stmt);

               if Present (Expr) and then Is_Call_Or_Raise (Expr) then
                  return True;
               end if;
            end if;

            Next (Stmt);
         end loop;

         return False;
      end Has_Side_Effect;

   --  Start of processing for Is_Exception_Safe

   begin
      --  When exceptions can't be propagated, the subprogram returns normally

      if No_Exception_Handlers_Set then
         return True;
      end if;

      --  If the checks handled by the back end are not disabled, we cannot
      --  ensure that no exception will be raised.

      if not Access_Checks_Suppressed (Empty)
        or else not Discriminant_Checks_Suppressed (Empty)
        or else not Range_Checks_Suppressed (Empty)
        or else not Index_Checks_Suppressed (Empty)
        or else Opt.Stack_Checking_Enabled
      then
         return False;
      end if;

      if Has_Side_Effect (First (Declarations (Subprogram)))
        or else
          Has_Side_Effect
            (First (Statements (Handled_Statement_Sequence (Subprogram))))
      then
         return False;
      else
         return True;
      end if;
   end Is_Exception_Safe;

   ---------------------------------
   -- Is_Potentially_Large_Family --
   ---------------------------------

   function Is_Potentially_Large_Family
     (Base_Index : Entity_Id;
      Conctyp    : Entity_Id;
      Lo         : Node_Id;
      Hi         : Node_Id) return Boolean
   is
   begin
      return Scope (Base_Index) = Standard_Standard
        and then Base_Index = Base_Type (Standard_Integer)
        and then Has_Discriminants (Conctyp)
        and then
          Present (Discriminant_Default_Value (First_Discriminant (Conctyp)))
        and then
          (Denotes_Discriminant (Lo, True)
             or else
           Denotes_Discriminant (Hi, True));
   end Is_Potentially_Large_Family;

   -------------------------------------
   -- Is_Private_Primitive_Subprogram --
   -------------------------------------

   function Is_Private_Primitive_Subprogram (Id : Entity_Id) return Boolean is
   begin
      return
        (Ekind (Id) = E_Function or else Ekind (Id) = E_Procedure)
          and then Is_Private_Primitive (Id);
   end Is_Private_Primitive_Subprogram;

   ------------------
   -- Index_Object --
   ------------------

   function Index_Object (Spec_Id : Entity_Id) return Entity_Id is
      Bod_Subp : constant Entity_Id := Protected_Body_Subprogram (Spec_Id);
      Formal   : Entity_Id;

   begin
      Formal := First_Formal (Bod_Subp);
      while Present (Formal) loop

         --  Look for formal parameter _E

         if Chars (Formal) = Name_uE then
            return Formal;
         end if;

         Next_Formal (Formal);
      end loop;

      --  A protected body subprogram should always have the parameter in
      --  question.

      raise Program_Error;
   end Index_Object;

   --------------------------------
   -- Make_Initialize_Protection --
   --------------------------------

   function Make_Initialize_Protection
     (Protect_Rec : Entity_Id) return List_Id
   is
      Loc         : constant Source_Ptr := Sloc (Protect_Rec);
      P_Arr       : Entity_Id;
      Pdec        : Node_Id;
      Ptyp        : constant Node_Id    :=
                      Corresponding_Concurrent_Type (Protect_Rec);
      Args        : List_Id;
      L           : constant List_Id    := New_List;
      Has_Entry   : constant Boolean    := Has_Entries (Ptyp);
      Prio_Type   : Entity_Id;
      Prio_Var    : Entity_Id           := Empty;
      Restricted  : constant Boolean    := Restricted_Profile;

   begin
      --  We may need two calls to properly initialize the object, one to
      --  Initialize_Protection, and possibly one to Install_Handlers if we
      --  have a pragma Attach_Handler.

      --  Get protected declaration. In the case of a task type declaration,
      --  this is simply the parent of the protected type entity. In the single
      --  protected object declaration, this parent will be the implicit type,
      --  and we can find the corresponding single protected object declaration
      --  by searching forward in the declaration list in the tree.

      --  Is the test for N_Single_Protected_Declaration needed here??? Nodes
      --  of this type should have been removed during semantic analysis.

      Pdec := Parent (Ptyp);
      while not Nkind_In (Pdec, N_Protected_Type_Declaration,
                                N_Single_Protected_Declaration)
      loop
         Next (Pdec);
      end loop;

      --  Build the parameter list for the call. Note that _Init is the name
      --  of the formal for the object to be initialized, which is the task
      --  value record itself.

      Args := New_List;

      --  For lock-free implementation, skip initializations of the Protection
      --  object.

      if not Uses_Lock_Free (Defining_Identifier (Pdec)) then

         --  Object parameter. This is a pointer to the object of type
         --  Protection used by the GNARL to control the protected object.

         Append_To (Args,
           Make_Attribute_Reference (Loc,
             Prefix =>
               Make_Selected_Component (Loc,
                 Prefix        => Make_Identifier (Loc, Name_uInit),
                 Selector_Name => Make_Identifier (Loc, Name_uObject)),
             Attribute_Name => Name_Unchecked_Access));

         --  Priority parameter. Set to Unspecified_Priority unless there is a
         --  Priority rep item, in which case we take the value from the pragma
         --  or attribute definition clause, or there is an Interrupt_Priority
         --  rep item and no Priority rep item, and we set the ceiling to
         --  Interrupt_Priority'Last, an implementation-defined value, see
         --  (RM D.3(10)).

         if Has_Rep_Item (Ptyp, Name_Priority, Check_Parents => False) then
            declare
               Prio_Clause : constant Node_Id :=
                               Get_Rep_Item
                                 (Ptyp, Name_Priority, Check_Parents => False);

               Prio : Node_Id;

            begin
               --  Pragma Priority

               if Nkind (Prio_Clause) = N_Pragma then
                  Prio :=
                    Expression
                     (First (Pragma_Argument_Associations (Prio_Clause)));

                  --  Get_Rep_Item returns either priority pragma.

                  if Pragma_Name (Prio_Clause) = Name_Priority then
                     Prio_Type := RTE (RE_Any_Priority);
                  else
                     Prio_Type := RTE (RE_Interrupt_Priority);
                  end if;

               --  Attribute definition clause Priority

               else
                  if Chars (Prio_Clause) = Name_Priority then
                     Prio_Type := RTE (RE_Any_Priority);
                  else
                     Prio_Type := RTE (RE_Interrupt_Priority);
                  end if;

                  Prio := Expression (Prio_Clause);
               end if;

               --  Always create a locale variable to capture the priority.
               --  The priority is also passed to Install_Restriced_Handlers.
               --  Note that it is really necessary to create this variable
               --  explicitly. It might be thought that removing side effects
               --  would the appropriate approach, but that could generate
               --  declarations improperly placed in the enclosing scope.

               Prio_Var := Make_Temporary (Loc, 'R', Prio);
               Append_To (L,
                 Make_Object_Declaration (Loc,
                   Defining_Identifier => Prio_Var,
                   Object_Definition   => New_Occurrence_Of (Prio_Type,  Loc),
                   Expression          => Relocate_Node (Prio)));

               Append_To (Args, New_Occurrence_Of (Prio_Var, Loc));
            end;

         --  When no priority is specified but an xx_Handler pragma is, we
         --  default to System.Interrupts.Default_Interrupt_Priority, see
         --  D.3(10).

         elsif Has_Attach_Handler (Ptyp)
           or else Has_Interrupt_Handler (Ptyp)
         then
            Append_To (Args,
              New_Occurrence_Of (RTE (RE_Default_Interrupt_Priority), Loc));

         --  Normal case, no priority or xx_Handler specified, default priority

         else
            Append_To (Args,
              New_Occurrence_Of (RTE (RE_Unspecified_Priority), Loc));
         end if;

         --  Test for Compiler_Info parameter. This parameter allows entry body
         --  procedures and barrier functions to be called from the runtime. It
         --  is a pointer to the record generated by the compiler to represent
         --  the protected object.

         --  A protected type without entries that covers an interface and
         --  overrides the abstract routines with protected procedures is
         --  considered equivalent to a protected type with entries in the
         --  context of dispatching select statements.

         --  Protected types with interrupt handlers (when not using a
         --  restricted profile) are also considered equivalent to protected
         --  types with entries.

         --  The types which are used (Static_Interrupt_Protection and
         --  Dynamic_Interrupt_Protection) are derived from Protection_Entries.

         declare
            Pkg_Id : constant RTU_Id := Corresponding_Runtime_Package (Ptyp);

            Called_Subp : RE_Id;

         begin
            case Pkg_Id is
               when System_Tasking_Protected_Objects_Entries =>
                  Called_Subp := RE_Initialize_Protection_Entries;

                  --  Argument Compiler_Info

                  Append_To (Args,
                    Make_Attribute_Reference (Loc,
                      Prefix         => Make_Identifier (Loc, Name_uInit),
                      Attribute_Name => Name_Address));

               when System_Tasking_Protected_Objects_Single_Entry =>
                  Called_Subp := RE_Initialize_Protection_Entry;

                  --  Argument Compiler_Info

                  Append_To (Args,
                    Make_Attribute_Reference (Loc,
                      Prefix         => Make_Identifier (Loc, Name_uInit),
                      Attribute_Name => Name_Address));

               when System_Tasking_Protected_Objects =>
                  Called_Subp := RE_Initialize_Protection;

               when others =>
                     raise Program_Error;
            end case;

            --  Entry_Queue_Maxes parameter. This is an access to an array of
            --  naturals representing the entry queue maximums for each entry
            --  in the protected type. Zero represents no max. The access is
            --  null if there is no limit for all entries (usual case).

            if Has_Entry
              and then Pkg_Id = System_Tasking_Protected_Objects_Entries
            then
               if Present (Entry_Max_Queue_Lengths_Array (Ptyp)) then
                  Append_To (Args,
                    Make_Attribute_Reference (Loc,
                      Prefix         =>
                        New_Occurrence_Of
                          (Entry_Max_Queue_Lengths_Array (Ptyp), Loc),
                      Attribute_Name => Name_Unrestricted_Access));
               else
                  Append_To (Args, Make_Null (Loc));
               end if;

            --  Edge cases exist where entry initialization functions are
            --  called, but no entries exist, so null is appended.

            elsif Pkg_Id = System_Tasking_Protected_Objects_Entries then
               Append_To (Args, Make_Null (Loc));
            end if;

            --  Entry_Bodies parameter. This is a pointer to an array of
            --  pointers to the entry body procedures and barrier functions of
            --  the object. If the protected type has no entries this object
            --  will not exist, in this case, pass a null (it can happen when
            --  there are protected interrupt handlers or interfaces).

            if Has_Entry then
               P_Arr := Entry_Bodies_Array (Ptyp);

               --  Argument Entry_Body (for single entry) or Entry_Bodies (for
               --  multiple entries).

               Append_To (Args,
                 Make_Attribute_Reference (Loc,
                   Prefix         => New_Occurrence_Of (P_Arr, Loc),
                   Attribute_Name => Name_Unrestricted_Access));

               if Pkg_Id = System_Tasking_Protected_Objects_Entries then

                  --  Find index mapping function (clumsy but ok for now)

                  while Ekind (P_Arr) /= E_Function loop
                     Next_Entity (P_Arr);
                  end loop;

                  Append_To (Args,
                    Make_Attribute_Reference (Loc,
                      Prefix         => New_Occurrence_Of (P_Arr, Loc),
                      Attribute_Name => Name_Unrestricted_Access));
               end if;

            elsif Pkg_Id = System_Tasking_Protected_Objects_Single_Entry then

               --  This is the case where we have a protected object with
               --  interfaces and no entries, and the single entry restriction
               --  is in effect. We pass a null pointer for the entry
               --  parameter because there is no actual entry.

               Append_To (Args, Make_Null (Loc));

            elsif Pkg_Id = System_Tasking_Protected_Objects_Entries then

               --  This is the case where we have a protected object with no
               --  entries and:
               --    - either interrupt handlers with non restricted profile,
               --    - or interfaces
               --  Note that the types which are used for interrupt handlers
               --  (Static/Dynamic_Interrupt_Protection) are derived from
               --  Protection_Entries. We pass two null pointers because there
               --  is no actual entry, and the initialization procedure needs
               --  both Entry_Bodies and Find_Body_Index.

               Append_To (Args, Make_Null (Loc));
               Append_To (Args, Make_Null (Loc));
            end if;

            Append_To (L,
              Make_Procedure_Call_Statement (Loc,
                Name                   =>
                  New_Occurrence_Of (RTE (Called_Subp), Loc),
                Parameter_Associations => Args));
         end;
      end if;

      if Has_Attach_Handler (Ptyp) then

         --  We have a list of N Attach_Handler (ProcI, ExprI), and we have to
         --  make the following call:

         --  Install_Handlers (_object,
         --    ((Expr1, Proc1'access), ...., (ExprN, ProcN'access));

         --  or, in the case of Ravenscar:

         --  Install_Restricted_Handlers
         --    (Prio, ((Expr1, Proc1'access), ...., (ExprN, ProcN'access)));

         declare
            Args  : constant List_Id := New_List;
            Table : constant List_Id := New_List;
            Ritem : Node_Id          := First_Rep_Item (Ptyp);

         begin
            --  Build the Priority parameter (only for ravenscar)

            if Restricted then

               --  Priority comes from a pragma

               if Present (Prio_Var) then
                  Append_To (Args, New_Occurrence_Of (Prio_Var, Loc));

               --  Priority is the default one

               else
                  Append_To (Args,
                    New_Occurrence_Of
                      (RTE (RE_Default_Interrupt_Priority), Loc));
               end if;
            end if;

            --  Build the Attach_Handler table argument

            while Present (Ritem) loop
               if Nkind (Ritem) = N_Pragma
                 and then Pragma_Name (Ritem) = Name_Attach_Handler
               then
                  declare
                     Handler : constant Node_Id :=
                                 First (Pragma_Argument_Associations (Ritem));

                     Interrupt : constant Node_Id := Next (Handler);
                     Expr      : constant Node_Id := Expression (Interrupt);

                  begin
                     Append_To (Table,
                       Make_Aggregate (Loc, Expressions => New_List (
                         Unchecked_Convert_To
                          (RTE (RE_System_Interrupt_Id), Expr),
                         Make_Attribute_Reference (Loc,
                           Prefix         =>
                             Make_Selected_Component (Loc,
                               Prefix        =>
                                 Make_Identifier (Loc, Name_uInit),
                               Selector_Name =>
                                 Duplicate_Subexpr_No_Checks
                                   (Expression (Handler))),
                           Attribute_Name => Name_Access))));
                  end;
               end if;

               Next_Rep_Item (Ritem);
            end loop;

            --  Append the table argument we just built

            Append_To (Args, Make_Aggregate (Loc, Table));

            --  Append the Install_Handlers (or Install_Restricted_Handlers)
            --  call to the statements.

            if Restricted then
               --  Call a simplified version of Install_Handlers to be used
               --  when the Ravenscar restrictions are in effect
               --  (Install_Restricted_Handlers).

               Append_To (L,
                 Make_Procedure_Call_Statement (Loc,
                   Name =>
                     New_Occurrence_Of
                       (RTE (RE_Install_Restricted_Handlers), Loc),
                   Parameter_Associations => Args));

            else
               if not Uses_Lock_Free (Defining_Identifier (Pdec)) then

                  --  First, prepends the _object argument

                  Prepend_To (Args,
                    Make_Attribute_Reference (Loc,
                      Prefix         =>
                        Make_Selected_Component (Loc,
                          Prefix        => Make_Identifier (Loc, Name_uInit),
                          Selector_Name =>
                            Make_Identifier (Loc, Name_uObject)),
                      Attribute_Name => Name_Unchecked_Access));
               end if;

               --  Then, insert call to Install_Handlers

               Append_To (L,
                 Make_Procedure_Call_Statement (Loc,
                   Name                   =>
                     New_Occurrence_Of (RTE (RE_Install_Handlers), Loc),
                   Parameter_Associations => Args));
            end if;
         end;
      end if;

      return L;
   end Make_Initialize_Protection;

   ---------------------------
   -- Make_Task_Create_Call --
   ---------------------------

   function Make_Task_Create_Call (Task_Rec : Entity_Id) return Node_Id is
      Loc    : constant Source_Ptr := Sloc (Task_Rec);
      Args   : List_Id;
      Ecount : Node_Id;
      Name   : Node_Id;
      Tdec   : Node_Id;
      Tdef   : Node_Id;
      Tnam   : Name_Id;
      Ttyp   : Node_Id;

   begin
      Ttyp := Corresponding_Concurrent_Type (Task_Rec);
      Tnam := Chars (Ttyp);

      --  Get task declaration. In the case of a task type declaration, this is
      --  simply the parent of the task type entity. In the single task
      --  declaration, this parent will be the implicit type, and we can find
      --  the corresponding single task declaration by searching forward in the
      --  declaration list in the tree.

      --  Is the test for N_Single_Task_Declaration needed here??? Nodes of
      --  this type should have been removed during semantic analysis.

      Tdec := Parent (Ttyp);
      while not Nkind_In (Tdec, N_Task_Type_Declaration,
                                N_Single_Task_Declaration)
      loop
         Next (Tdec);
      end loop;

      --  Now we can find the task definition from this declaration

      Tdef := Task_Definition (Tdec);

      --  Build the parameter list for the call. Note that _Init is the name
      --  of the formal for the object to be initialized, which is the task
      --  value record itself.

      Args := New_List;

      --  Priority parameter. Set to Unspecified_Priority unless there is a
      --  Priority rep item, in which case we take the value from the rep item.

      if Has_Rep_Item (Ttyp, Name_Priority, Check_Parents => False) then
         Append_To (Args,
           Make_Selected_Component (Loc,
             Prefix        => Make_Identifier (Loc, Name_uInit),
             Selector_Name => Make_Identifier (Loc, Name_uPriority)));
      else
         Append_To (Args,
           New_Occurrence_Of (RTE (RE_Unspecified_Priority), Loc));
      end if;

      --  Optional Stack parameter

      if Restricted_Profile then

         --  If the stack has been preallocated by the expander then
         --  pass its address. Otherwise, pass a null address.

         if Preallocated_Stacks_On_Target then
            Append_To (Args,
              Make_Attribute_Reference (Loc,
                Prefix         =>
                  Make_Selected_Component (Loc,
                    Prefix        => Make_Identifier (Loc, Name_uInit),
                    Selector_Name => Make_Identifier (Loc, Name_uStack)),
                Attribute_Name => Name_Address));

         else
            Append_To (Args,
              New_Occurrence_Of (RTE (RE_Null_Address), Loc));
         end if;
      end if;

      --  Size parameter. If no Storage_Size pragma is present, then
      --  the size is taken from the taskZ variable for the type, which
      --  is either Unspecified_Size, or has been reset by the use of
      --  a Storage_Size attribute definition clause. If a pragma is
      --  present, then the size is taken from the _Size field of the
      --  task value record, which was set from the pragma value.

      if Present (Tdef) and then Has_Storage_Size_Pragma (Tdef) then
         Append_To (Args,
           Make_Selected_Component (Loc,
             Prefix        => Make_Identifier (Loc, Name_uInit),
             Selector_Name => Make_Identifier (Loc, Name_uSize)));

      else
         Append_To (Args,
           New_Occurrence_Of (Storage_Size_Variable (Ttyp), Loc));
      end if;

      --  Secondary_Stack_Size parameter. Set Default_Secondary_Stack_Size
      --  unless there is a Secondary_Stack_Size rep item, in which case we
      --  take the value from the rep item. If the restriction
      --  No_Secondary_Stack is active then a size of 0 is passed regardless
      --  to prevent the allocation of the unused stack.

      if Restriction_Active (No_Secondary_Stack) then
         Append_To (Args, Make_Integer_Literal (Loc, 0));

      elsif Has_Rep_Item (Ttyp, Name_Secondary_Stack_Size,
                       Check_Parents => False)
      then
         Append_To (Args,
             Make_Selected_Component (Loc,
               Prefix        => Make_Identifier (Loc, Name_uInit),
               Selector_Name =>
                 Make_Identifier (Loc, Name_uSecondary_Stack_Size)));

      else
         Append_To (Args,
           New_Occurrence_Of (RTE (RE_Unspecified_Size), Loc));
      end if;

      --  Task_Info parameter. Set to Unspecified_Task_Info unless there is a
      --  Task_Info pragma, in which case we take the value from the pragma.

      if Has_Rep_Pragma (Ttyp, Name_Task_Info, Check_Parents => False) then
         Append_To (Args,
           Make_Selected_Component (Loc,
             Prefix        => Make_Identifier (Loc, Name_uInit),
             Selector_Name => Make_Identifier (Loc, Name_uTask_Info)));

      else
         Append_To (Args,
           New_Occurrence_Of (RTE (RE_Unspecified_Task_Info), Loc));
      end if;

      --  CPU parameter. Set to Unspecified_CPU unless there is a CPU rep item,
      --  in which case we take the value from the rep item. The parameter is
      --  passed as an Integer because in the case of unspecified CPU the
      --  value is not in the range of CPU_Range.

      if Has_Rep_Item (Ttyp, Name_CPU, Check_Parents => False) then
         Append_To (Args,
           Convert_To (Standard_Integer,
             Make_Selected_Component (Loc,
               Prefix        => Make_Identifier (Loc, Name_uInit),
               Selector_Name => Make_Identifier (Loc, Name_uCPU))));
      else
         Append_To (Args,
           New_Occurrence_Of (RTE (RE_Unspecified_CPU), Loc));
      end if;

      if not Restricted_Profile then

         --  Deadline parameter. If no Relative_Deadline pragma is present,
         --  then the deadline is Time_Span_Zero. If a pragma is present, then
         --  the deadline is taken from the _Relative_Deadline field of the
         --  task value record, which was set from the pragma value. Note that
         --  this parameter must not be generated for the restricted profiles
         --  since Ravenscar does not allow deadlines.

         --  Case where pragma Relative_Deadline applies: use given value

         if Present (Tdef) and then Has_Relative_Deadline_Pragma (Tdef) then
            Append_To (Args,
              Make_Selected_Component (Loc,
                Prefix        => Make_Identifier (Loc, Name_uInit),
                Selector_Name =>
                  Make_Identifier (Loc, Name_uRelative_Deadline)));

         --  No pragma Relative_Deadline apply to the task

         else
            Append_To (Args,
              New_Occurrence_Of (RTE (RE_Time_Span_Zero), Loc));
         end if;

         --  Dispatching_Domain parameter. If no Dispatching_Domain rep item is
         --  present, then the dispatching domain is null. If a rep item is
         --  present, then the dispatching domain is taken from the
         --  _Dispatching_Domain field of the task value record, which was set
         --  from the rep item value.

         --  Case where Dispatching_Domain rep item applies: use given value

         if Has_Rep_Item
              (Ttyp, Name_Dispatching_Domain, Check_Parents => False)
         then
            Append_To (Args,
              Make_Selected_Component (Loc,
                Prefix        =>
                  Make_Identifier (Loc, Name_uInit),
                Selector_Name =>
                  Make_Identifier (Loc, Name_uDispatching_Domain)));

         --  No pragma or aspect Dispatching_Domain applies to the task

         else
            Append_To (Args, Make_Null (Loc));
         end if;

         --  Number of entries. This is an expression of the form:

         --    n + _Init.a'Length + _Init.a'B'Length + ...

         --  where a,b... are the entry family names for the task definition

         Ecount :=
           Build_Entry_Count_Expression
             (Ttyp,
              Component_Items
                (Component_List
                   (Type_Definition
                      (Parent (Corresponding_Record_Type (Ttyp))))),
              Loc);
         Append_To (Args, Ecount);

         --  Master parameter. This is a reference to the _Master parameter of
         --  the initialization procedure, except in the case of the pragma
         --  Restrictions (No_Task_Hierarchy) where the value is fixed to
         --  System.Tasking.Library_Task_Level.

         if Restriction_Active (No_Task_Hierarchy) = False then
            Append_To (Args, Make_Identifier (Loc, Name_uMaster));
         else
            Append_To (Args,
              New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
         end if;
      end if;

      --  State parameter. This is a pointer to the task body procedure. The
      --  required value is obtained by taking 'Unrestricted_Access of the task
      --  body procedure and converting it (with an unchecked conversion) to
      --  the type required by the task kernel. For further details, see the
      --  description of Expand_N_Task_Body. We use 'Unrestricted_Access rather
      --  than 'Address in order to avoid creating trampolines.

      declare
         Body_Proc    : constant Node_Id := Get_Task_Body_Procedure (Ttyp);
         Subp_Ptr_Typ : constant Node_Id :=
                          Create_Itype (E_Access_Subprogram_Type, Tdec);
         Ref          : constant Node_Id := Make_Itype_Reference (Loc);

      begin
         Set_Directly_Designated_Type (Subp_Ptr_Typ, Body_Proc);
         Set_Etype (Subp_Ptr_Typ, Subp_Ptr_Typ);

         --  Be sure to freeze a reference to the access-to-subprogram type,
         --  otherwise gigi will complain that it's in the wrong scope, because
         --  it's actually inside the init procedure for the record type that
         --  corresponds to the task type.

         Set_Itype (Ref, Subp_Ptr_Typ);
         Append_Freeze_Action (Task_Rec, Ref);

         Append_To (Args,
           Unchecked_Convert_To (RTE (RE_Task_Procedure_Access),
             Make_Qualified_Expression (Loc,
               Subtype_Mark => New_Occurrence_Of (Subp_Ptr_Typ, Loc),
               Expression   =>
                 Make_Attribute_Reference (Loc,
                   Prefix         => New_Occurrence_Of (Body_Proc, Loc),
                   Attribute_Name => Name_Unrestricted_Access))));
      end;

      --  Discriminants parameter. This is just the address of the task
      --  value record itself (which contains the discriminant values

      Append_To (Args,
        Make_Attribute_Reference (Loc,
          Prefix => Make_Identifier (Loc, Name_uInit),
          Attribute_Name => Name_Address));

      --  Elaborated parameter. This is an access to the elaboration Boolean

      Append_To (Args,
        Make_Attribute_Reference (Loc,
          Prefix => Make_Identifier (Loc, New_External_Name (Tnam, 'E')),
          Attribute_Name => Name_Unchecked_Access));

      --  Add Chain parameter (not done for sequential elaboration policy, see
      --  comment for Create_Restricted_Task_Sequential in s-tarest.ads).

      if Partition_Elaboration_Policy /= 'S' then
         Append_To (Args, Make_Identifier (Loc, Name_uChain));
      end if;

      --  Task name parameter. Take this from the _Task_Id parameter to the
      --  init call unless there is a Task_Name pragma, in which case we take
      --  the value from the pragma.

      if Has_Rep_Pragma (Ttyp, Name_Task_Name, Check_Parents => False) then
         --  Copy expression in full, because it may be dynamic and have
         --  side effects.

         Append_To (Args,
           New_Copy_Tree
             (Expression
               (First
                 (Pragma_Argument_Associations
                   (Get_Rep_Pragma
                     (Ttyp, Name_Task_Name, Check_Parents => False))))));

      else
         Append_To (Args, Make_Identifier (Loc, Name_uTask_Name));
      end if;

      --  Created_Task parameter. This is the _Task_Id field of the task
      --  record value

      Append_To (Args,
        Make_Selected_Component (Loc,
          Prefix        => Make_Identifier (Loc, Name_uInit),
          Selector_Name => Make_Identifier (Loc, Name_uTask_Id)));

      declare
         Create_RE : RE_Id;

      begin
         if Restricted_Profile then
            if Partition_Elaboration_Policy = 'S' then
               Create_RE := RE_Create_Restricted_Task_Sequential;
            else
               Create_RE := RE_Create_Restricted_Task;
            end if;
         else
            Create_RE := RE_Create_Task;
         end if;

         Name := New_Occurrence_Of (RTE (Create_RE), Loc);
      end;

      return
        Make_Procedure_Call_Statement (Loc,
          Name                   => Name,
          Parameter_Associations => Args);
   end Make_Task_Create_Call;

   ------------------------------
   -- Next_Protected_Operation --
   ------------------------------

   function Next_Protected_Operation (N : Node_Id) return Node_Id is
      Next_Op : Node_Id;

   begin
      --  Check whether there is a subsequent body for a protected operation
      --  in the current protected body. In Ada2012 that includes expression
      --  functions that are completions.

      Next_Op := Next (N);
      while Present (Next_Op)
        and then not Nkind_In (Next_Op,
           N_Subprogram_Body, N_Entry_Body, N_Expression_Function)
      loop
         Next (Next_Op);
      end loop;

      return Next_Op;
   end Next_Protected_Operation;

   ---------------------
   -- Null_Statements --
   ---------------------

   function Null_Statements (Stats : List_Id) return Boolean is
      Stmt : Node_Id;

   begin
      Stmt := First (Stats);
      while Nkind (Stmt) /= N_Empty
        and then (Nkind_In (Stmt, N_Null_Statement, N_Label)
                   or else
                     (Nkind (Stmt) = N_Pragma
                       and then
                         Nam_In (Pragma_Name_Unmapped (Stmt),
                                 Name_Unreferenced,
                                 Name_Unmodified,
                                 Name_Warnings)))
      loop
         Next (Stmt);
      end loop;

      return Nkind (Stmt) = N_Empty;
   end Null_Statements;

   --------------------------
   -- Parameter_Block_Pack --
   --------------------------

   function Parameter_Block_Pack
     (Loc     : Source_Ptr;
      Blk_Typ : Entity_Id;
      Actuals : List_Id;
      Formals : List_Id;
      Decls   : List_Id;
      Stmts   : List_Id) return Node_Id
   is
      Actual    : Entity_Id;
      Expr      : Node_Id := Empty;
      Formal    : Entity_Id;
      Has_Param : Boolean := False;
      P         : Entity_Id;
      Params    : List_Id;
      Temp_Asn  : Node_Id;
      Temp_Nam  : Node_Id;

   begin
      Actual := First (Actuals);
      Formal := Defining_Identifier (First (Formals));
      Params := New_List;
      while Present (Actual) loop
         if Is_By_Copy_Type (Etype (Actual)) then
            --  Generate:
            --    Jnn : aliased <formal-type>

            Temp_Nam := Make_Temporary (Loc, 'J');

            Append_To (Decls,
              Make_Object_Declaration (Loc,
                Aliased_Present     => True,
                Defining_Identifier => Temp_Nam,
                Object_Definition   =>
                  New_Occurrence_Of (Etype (Formal), Loc)));

            if Ekind (Formal) /= E_Out_Parameter then

               --  Generate:
               --    Jnn := <actual>

               Temp_Asn :=
                 New_Occurrence_Of (Temp_Nam, Loc);

               Set_Assignment_OK (Temp_Asn);

               Append_To (Stmts,
                 Make_Assignment_Statement (Loc,
                   Name       => Temp_Asn,
                   Expression => New_Copy_Tree (Actual)));
            end if;

            --  Generate:
            --    Jnn'unchecked_access

            Append_To (Params,
              Make_Attribute_Reference (Loc,
                Attribute_Name => Name_Unchecked_Access,
                Prefix         => New_Occurrence_Of (Temp_Nam, Loc)));

            Has_Param := True;

         --  The controlling parameter is omitted

         else
            if not Is_Controlling_Actual (Actual) then
               Append_To (Params,
                 Make_Reference (Loc, New_Copy_Tree (Actual)));

               Has_Param := True;
            end if;
         end if;

         Next_Actual (Actual);
         Next_Formal_With_Extras (Formal);
      end loop;

      if Has_Param then
         Expr := Make_Aggregate (Loc, Params);
      end if;

      --  Generate:
      --    P : Ann := (
      --      J1'unchecked_access;
      --      <actual2>'reference;
      --      ...);

      P := Make_Temporary (Loc, 'P');

      Append_To (Decls,
        Make_Object_Declaration (Loc,
          Defining_Identifier => P,
          Object_Definition   => New_Occurrence_Of (Blk_Typ, Loc),
          Expression          => Expr));

      return P;
   end Parameter_Block_Pack;

   ----------------------------
   -- Parameter_Block_Unpack --
   ----------------------------

   function Parameter_Block_Unpack
     (Loc     : Source_Ptr;
      P       : Entity_Id;
      Actuals : List_Id;
      Formals : List_Id) return List_Id
   is
      Actual    : Entity_Id;
      Asnmt     : Node_Id;
      Formal    : Entity_Id;
      Has_Asnmt : Boolean := False;
      Result    : constant List_Id := New_List;

   begin
      Actual := First (Actuals);
      Formal := Defining_Identifier (First (Formals));
      while Present (Actual) loop
         if Is_By_Copy_Type (Etype (Actual))
           and then Ekind (Formal) /= E_In_Parameter
         then
            --  Generate:
            --    <actual> := P.<formal>;

            Asnmt :=
              Make_Assignment_Statement (Loc,
                Name       =>
                  New_Copy (Actual),
                Expression =>
                  Make_Explicit_Dereference (Loc,
                    Make_Selected_Component (Loc,
                      Prefix        =>
                        New_Occurrence_Of (P, Loc),
                      Selector_Name =>
                        Make_Identifier (Loc, Chars (Formal)))));

            Set_Assignment_OK (Name (Asnmt));
            Append_To (Result, Asnmt);

            Has_Asnmt := True;
         end if;

         Next_Actual (Actual);
         Next_Formal_With_Extras (Formal);
      end loop;

      if Has_Asnmt then
         return Result;
      else
         return New_List (Make_Null_Statement (Loc));
      end if;
   end Parameter_Block_Unpack;

   ----------------------
   -- Set_Discriminals --
   ----------------------

   procedure Set_Discriminals (Dec : Node_Id) is
      D       : Entity_Id;
      Pdef    : Entity_Id;
      D_Minal : Entity_Id;

   begin
      pragma Assert (Nkind (Dec) = N_Protected_Type_Declaration);
      Pdef := Defining_Identifier (Dec);

      if Has_Discriminants (Pdef) then
         D := First_Discriminant (Pdef);
         while Present (D) loop
            D_Minal :=
              Make_Defining_Identifier (Sloc (D),
                Chars => New_External_Name (Chars (D), 'D'));

            Set_Ekind (D_Minal, E_Constant);
            Set_Etype (D_Minal, Etype (D));
            Set_Scope (D_Minal, Pdef);
            Set_Discriminal (D, D_Minal);
            Set_Discriminal_Link (D_Minal, D);

            Next_Discriminant (D);
         end loop;
      end if;
   end Set_Discriminals;

   -----------------------
   -- Trivial_Accept_OK --
   -----------------------

   function Trivial_Accept_OK return Boolean is
   begin
      case Opt.Task_Dispatching_Policy is

         --  If we have the default task dispatching policy in effect, we can
         --  definitely do the optimization (one way of looking at this is to
         --  think of the formal definition of the default policy being allowed
         --  to run any task it likes after a rendezvous, so even if notionally
         --  a full rescheduling occurs, we can say that our dispatching policy
         --  (i.e. the default dispatching policy) reorders the queue to be the
         --  same as just before the call.

         when ' ' =>
            return True;

         --  FIFO_Within_Priorities certainly does not permit this
         --  optimization since the Rendezvous is a scheduling action that may
         --  require some other task to be run.

         when 'F' =>
            return False;

         --  For now, disallow the optimization for all other policies. This
         --  may be over-conservative, but it is certainly not incorrect.

         when others =>
            return False;

      end case;
   end Trivial_Accept_OK;

end Exp_Ch9;