ada: Fix small irregularity for Master_Id of anonymous access result type

The Master_Id of access types whose designated type contains tasks is set to
a renaming of the current _Master variable by means of Build_Master_Renaming

The exception is for anonymous access result types, whose Master_Id is set
to the current _Master variable by Check_Anonymous_Access_Return_With_Tasks.

This is fully correct because the entity of the variable is preresolved, but
is ambiguous in the .dg file because there can be several _Master variables
in the subprogram, which effectively represent distinct masters.  Therefore
this makes the case of anonymous access result types also use a renaming.

gcc/ada/ChangeLog:

	* exp_ch9.ads (Build_Master_Declaration): Minor tweaks in comment.
	(Build_Master_Entity): Likewise.
	(Build_Master_Renaming): Likewise.
	(Build_Master_Renaming_Declaration): New function declaration.
	* exp_ch9.adb (Build_Master_Declaration): Move around.
	(Build_Master_Renaming_Declaration): New function.
	(Build_Master_Renaming): Call Build_Master_Renaming_Declaration
	to build the renaming declaration.
	* sem_ch6.adb (Check_Anonymous_Access_Return_With_Tasks): Remove
	useless guard on Declarations (N).  Create a renaming declaration
	for the current _Master variable and set is as the Master_Id of
	the access result type.

diff --git a/gcc/ada/exp_ch9.adb b/gcc/ada/exp_ch9.adb
index 054c6db06057e452d68a62f7b0d11039d50c895d..6e1e0fedf34c9ed1f0b31ec1ad6b100f4760d593 100644 (file)
--- a/gcc/ada/exp_ch9.adb
+++ b/gcc/ada/exp_ch9.adb
@@ -1345,52 +1345,6 @@ package body Exp_Ch9 is
       return Ecount;
    end Build_Entry_Count_Expression;
 
-   ------------------------------
-   -- Build_Master_Declaration --
-   ------------------------------
-
-   function Build_Master_Declaration (Loc : Source_Ptr) return Node_Id is
-      Master_Decl : Node_Id;
-
-   begin
-      --  Generate a dummy master if tasks or tasking hierarchies are
-      --  prohibited.
-
-      --    _Master : constant Integer := Library_Task_Level;
-
-      if not Tasking_Allowed
-        or else Restrictions.Set (No_Task_Hierarchy)
-        or else not RTE_Available (RE_Current_Master)
-      then
-         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_Integer_Literal (Loc, Library_Task_Level));
-
-      --  Generate:
-      --    _master : constant Integer := Current_Master.all;
-
-      else
-         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)));
-      end if;
-
-      return Master_Decl;
-   end Build_Master_Declaration;
-
    ---------------------------
    -- Build_Parameter_Block --
    ---------------------------
@@ -3027,6 +2981,51 @@ package body Exp_Ch9 is
           Handled_Statement_Sequence => Hand_Stmt_Seq);
    end Build_Lock_Free_Unprotected_Subprogram_Body;
 
+   ------------------------------
+   -- Build_Master_Declaration --
+   ------------------------------
+
+   function Build_Master_Declaration (Loc : Source_Ptr) return Node_Id is
+      Master_Decl : Node_Id;
+
+   begin
+      --  Generate a dummy master if tasks or tasking hierarchies are
+      --  prohibited:
+      --    _Master : constant Integer := Library_Task_Level;
+
+      if not Tasking_Allowed
+        or else Restrictions.Set (No_Task_Hierarchy)
+        or else not RTE_Available (RE_Current_Master)
+      then
+         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_Integer_Literal (Loc, Library_Task_Level));
+
+      --  Generate:
+      --    _Master : constant Integer := Current_Master.all;
+
+      else
+         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)));
+      end if;
+
+      return Master_Decl;
+   end Build_Master_Declaration;
+
    -------------------------
    -- Build_Master_Entity --
    -------------------------
@@ -3107,6 +3106,35 @@ package body Exp_Ch9 is
       end if;
    end Build_Master_Entity;
 
+   ---------------------------------------
+   -- Build_Master_Renaming_Declaration --
+   ---------------------------------------
+
+   function Build_Master_Renaming_Declaration
+     (Ptr_Typ : Entity_Id;
+      Loc     : Source_Ptr) return Node_Id
+   is
+      --  Generate:
+      --    <Ptr_Typ>M : Integer renames _Master;
+      --  and add a numeric suffix to the name to ensure that it is
+      --  unique in case other access types in nested constructs
+      --  are homonyms of this one.
+
+      Master_Id : constant Entity_Id :=
+        Make_Defining_Identifier (Loc,
+          New_External_Name (Chars (Ptr_Typ), 'M', -1));
+
+      Master_Decl : constant Node_Id :=
+        Make_Object_Renaming_Declaration (Loc,
+          Defining_Identifier => Master_Id,
+          Subtype_Mark        =>
+            New_Occurrence_Of (Standard_Integer, Loc),
+          Name                => Make_Identifier (Loc, Name_uMaster));
+
+   begin
+      return Master_Decl;
+   end Build_Master_Renaming_Declaration;
+
    ---------------------------
    -- Build_Master_Renaming --
    ---------------------------
@@ -3115,10 +3143,10 @@ package body Exp_Ch9 is
      (Ptr_Typ : Entity_Id;
       Ins_Nod : Node_Id := Empty)
    is
-      Loc         : constant Source_Ptr := Sloc (Ptr_Typ);
+      Loc : constant Source_Ptr := Sloc (Ptr_Typ);
+
       Context     : Node_Id;
       Master_Decl : Node_Id;
-      Master_Id   : Entity_Id;
 
    begin
       --  No action needed if the run-time has no tasking support
@@ -3127,6 +3155,8 @@ package body Exp_Ch9 is
          return;
       end if;
 
+      Master_Decl := Build_Master_Renaming_Declaration (Ptr_Typ, Loc);
+
       --  Determine the proper context to insert the master renaming
 
       if Present (Ins_Nod) then
@@ -3169,28 +3199,11 @@ package body Exp_Ch9 is
          Context := Parent (Ptr_Typ);
       end if;
 
-      --  Generate:
-      --    <Ptr_Typ>M : Master_Id renames _Master;
-      --  and add a numeric suffix to the name to ensure that it is
-      --  unique in case other access types in nested constructs
-      --  are homonyms of this one.
-
-      Master_Id :=
-        Make_Defining_Identifier (Loc,
-          New_External_Name (Chars (Ptr_Typ), 'M', -1));
-
-      Master_Decl :=
-        Make_Object_Renaming_Declaration (Loc,
-          Defining_Identifier => Master_Id,
-          Subtype_Mark        =>
-            New_Occurrence_Of (Standard_Integer, 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);
+      Set_Master_Id (Ptr_Typ, Defining_Identifier (Master_Decl));
    end Build_Master_Renaming;
 
    ---------------------------

diff --git a/gcc/ada/exp_ch9.ads b/gcc/ada/exp_ch9.ads
index 29008d07d29e6e36e0537bfa569d2c671f47c3e0..a4354eeec858d73e765893957371d9a254979523 100644 (file)
--- a/gcc/ada/exp_ch9.ads
+++ b/gcc/ada/exp_ch9.ads
@@ -54,23 +54,29 @@ package Exp_Ch9 is
    --  For targets supporting tasks, generate:
    --      _Master : constant Integer := Current_Master.all;
    --  For targets where tasks or tasking hierarchies are prohibited, generate:
-   --      _Master : constant Master_Id := 3;
+   --      _Master : constant Integer := Library_Task_Level;
 
    procedure Build_Master_Entity (Obj_Or_Typ : Entity_Id);
    --  Given the name of an object or a type which is either a task, contains
-   --  tasks or designates tasks, create a _master in the appropriate scope
+   --  tasks or designates tasks, create a _Master in the appropriate scope
    --  which captures the value of Current_Master. Mark the nearest enclosing
    --  body or block as being a task master.
 
+   function Build_Master_Renaming_Declaration
+     (Ptr_Typ : Entity_Id;
+      Loc     : Source_Ptr) return Node_Id;
+   --  Generate:
+   --     <Ptr_Typ>M : Integer renames _Master;
+
    procedure Build_Master_Renaming
      (Ptr_Typ : Entity_Id;
       Ins_Nod : Node_Id := Empty);
    --  Given an access type Ptr_Typ whose designated type is either a task or
    --  contains tasks, create a renaming of the form:
    --
-   --     <Ptr_Typ>M : Master_Id renames _Master;
+   --     <Ptr_Typ>M : Integer renames _Master;
    --
-   --  where _master denotes the task master of the enclosing context. Ins_Nod
+   --  where _Master denotes the task master of the enclosing context. Ins_Nod
    --  is used to provide a specific insertion node for the renaming.
 
    function Build_Protected_Sub_Specification

diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb
index bd6c66d8c9914b65707294e5ed98e552bfc4ae99..73ad8cf8d54ad99eaa211bc4102b03dfaae697cf 100644 (file)
--- a/gcc/ada/sem_ch6.adb
+++ b/gcc/ada/sem_ch6.adb
@@ -2850,18 +2850,23 @@ package body Sem_Ch6 is
          then
             Decl := Build_Master_Declaration (Loc);
 
-            if Present (Declarations (N)) then
-               Prepend (Decl, Declarations (N));
-            else
-               Set_Declarations (N, New_List (Decl));
-            end if;
+            Prepend_To (Declarations (N), Decl);
+
+            --  Although Scop has a _master entity, it is not marked as a task
+            --  master as Build_Master_Entity would do, because its completion
+            --  cannot wait for the tasks it indirectly returns to terminate.
 
             Set_Has_Master_Entity (Scop);
-            Set_Master_Id (Etype (Scop), Defining_Identifier (Decl));
 
-            --  Now mark the enclosing construct as a task master
+            --  Instead the enclosing construct is marked as a task master
 
             Mark_Construct_As_Task_Master (Parent (N));
+
+            Decl := Build_Master_Renaming_Declaration (Etype (Scop), Loc);
+
+            Insert_After (First (Declarations (N)), Decl);
+
+            Set_Master_Id (Etype (Scop), Defining_Identifier (Decl));
          end if;
       end Check_Anonymous_Access_Return_With_Tasks;