1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Exp_Atag; use Exp_Atag;
32 with Exp_Ch2; use Exp_Ch2;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch9; use Exp_Ch9;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Imgv; use Exp_Imgv;
38 with Exp_Pakd; use Exp_Pakd;
39 with Exp_Strm; use Exp_Strm;
40 with Exp_Tss; use Exp_Tss;
41 with Exp_Util; use Exp_Util;
42 with Fname; use Fname;
43 with Freeze; use Freeze;
44 with Gnatvsn; use Gnatvsn;
45 with Itypes; use Itypes;
47 with Namet; use Namet;
48 with Nmake; use Nmake;
49 with Nlists; use Nlists;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch7; use Sem_Ch7;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Eval; use Sem_Eval;
60 with Sem_Res; use Sem_Res;
61 with Sem_Util; use Sem_Util;
62 with Sinfo; use Sinfo;
63 with Snames; use Snames;
64 with Stand; use Stand;
65 with Stringt; use Stringt;
66 with Targparm; use Targparm;
67 with Tbuild; use Tbuild;
68 with Ttypes; use Ttypes;
69 with Uintp; use Uintp;
70 with Uname; use Uname;
71 with Validsw; use Validsw;
73 package body Exp_Attr is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 function Build_Array_VS_Func
81 Nod : Node_Id) return Entity_Id;
82 -- Build function to test Valid_Scalars for array type A_Type. Nod is the
83 -- Valid_Scalars attribute node, used to insert the function body, and the
84 -- value returned is the entity of the constructed function body. We do not
85 -- bother to generate a separate spec for this subprogram.
87 function Build_Record_VS_Func
89 Nod : Node_Id) return Entity_Id;
90 -- Build function to test Valid_Scalars for record type A_Type. Nod is the
91 -- Valid_Scalars attribute node, used to insert the function body, and the
92 -- value returned is the entity of the constructed function body. We do not
93 -- bother to generate a separate spec for this subprogram.
95 procedure Compile_Stream_Body_In_Scope
100 -- The body for a stream subprogram may be generated outside of the scope
101 -- of the type. If the type is fully private, it may depend on the full
102 -- view of other types (e.g. indexes) that are currently private as well.
103 -- We install the declarations of the package in which the type is declared
104 -- before compiling the body in what is its proper environment. The Check
105 -- parameter indicates if checks are to be suppressed for the stream body.
106 -- We suppress checks for array/record reads, since the rule is that these
107 -- are like assignments, out of range values due to uninitialized storage,
108 -- or other invalid values do NOT cause a Constraint_Error to be raised.
109 -- If we are within an instance body all visibility has been established
110 -- already and there is no need to install the package.
112 -- This mechanism is now extended to the component types of the array type,
113 -- when the component type is not in scope and is private, to handle
114 -- properly the case when the full view has defaulted discriminants.
116 -- This special processing is ultimately caused by the fact that the
117 -- compiler lacks a well-defined phase when full views are visible
118 -- everywhere. Having such a separate pass would remove much of the
119 -- special-case code that shuffles partial and full views in the middle
120 -- of semantic analysis and expansion.
122 procedure Expand_Access_To_Protected_Op
126 -- An attribute reference to a protected subprogram is transformed into
127 -- a pair of pointers: one to the object, and one to the operations.
128 -- This expansion is performed for 'Access and for 'Unrestricted_Access.
130 procedure Expand_Fpt_Attribute
135 -- This procedure expands a call to a floating-point attribute function.
136 -- N is the attribute reference node, and Args is a list of arguments to
137 -- be passed to the function call. Pkg identifies the package containing
138 -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args
139 -- have already been converted to the floating-point type for which Pkg was
140 -- instantiated. The Nam argument is the relevant attribute processing
141 -- routine to be called. This is the same as the attribute name, except in
142 -- the Unaligned_Valid case.
144 procedure Expand_Fpt_Attribute_R (N : Node_Id);
145 -- This procedure expands a call to a floating-point attribute function
146 -- that takes a single floating-point argument. The function to be called
147 -- is always the same as the attribute name.
149 procedure Expand_Fpt_Attribute_RI (N : Node_Id);
150 -- This procedure expands a call to a floating-point attribute function
151 -- that takes one floating-point argument and one integer argument. The
152 -- function to be called is always the same as the attribute name.
154 procedure Expand_Fpt_Attribute_RR (N : Node_Id);
155 -- This procedure expands a call to a floating-point attribute function
156 -- that takes two floating-point arguments. The function to be called
157 -- is always the same as the attribute name.
159 procedure Expand_Loop_Entry_Attribute (N : Node_Id);
160 -- Handle the expansion of attribute 'Loop_Entry. As a result, the related
161 -- loop may be converted into a conditional block. See body for details.
163 procedure Expand_Min_Max_Attribute (N : Node_Id);
164 -- Handle the expansion of attributes 'Max and 'Min, including expanding
165 -- then out if we are in Modify_Tree_For_C mode.
167 procedure Expand_Pred_Succ_Attribute (N : Node_Id);
168 -- Handles expansion of Pred or Succ attributes for case of non-real
169 -- operand with overflow checking required.
171 procedure Expand_Update_Attribute (N : Node_Id);
172 -- Handle the expansion of attribute Update
174 function Get_Index_Subtype (N : Node_Id) return Entity_Id;
175 -- Used for Last, Last, and Length, when the prefix is an array type.
176 -- Obtains the corresponding index subtype.
178 procedure Find_Fat_Info
180 Fat_Type : out Entity_Id;
181 Fat_Pkg : out RE_Id);
182 -- Given a floating-point type T, identifies the package containing the
183 -- attributes for this type (returned in Fat_Pkg), and the corresponding
184 -- type for which this package was instantiated from Fat_Gen. Error if T
185 -- is not a floating-point type.
187 function Find_Stream_Subprogram
189 Nam : TSS_Name_Type) return Entity_Id;
190 -- Returns the stream-oriented subprogram attribute for Typ. For tagged
191 -- types, the corresponding primitive operation is looked up, else the
192 -- appropriate TSS from the type itself, or from its closest ancestor
193 -- defining it, is returned. In both cases, inheritance of representation
194 -- aspects is thus taken into account.
196 function Full_Base (T : Entity_Id) return Entity_Id;
197 -- The stream functions need to examine the underlying representation of
198 -- composite types. In some cases T may be non-private but its base type
199 -- is, in which case the function returns the corresponding full view.
201 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
202 -- Given a type, find a corresponding stream convert pragma that applies to
203 -- the implementation base type of this type (Typ). If found, return the
204 -- pragma node, otherwise return Empty if no pragma is found.
206 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
207 -- Utility for array attributes, returns true on packed constrained
208 -- arrays, and on access to same.
210 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
211 -- Returns true iff the given node refers to an attribute call that
212 -- can be expanded directly by the back end and does not need front end
213 -- expansion. Typically used for rounding and truncation attributes that
214 -- appear directly inside a conversion to integer.
216 -------------------------
217 -- Build_Array_VS_Func --
218 -------------------------
220 function Build_Array_VS_Func
222 Nod : Node_Id) return Entity_Id
224 Loc : constant Source_Ptr := Sloc (Nod);
225 Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
226 Comp_Type : constant Entity_Id := Component_Type (A_Type);
227 Body_Stmts : List_Id;
228 Index_List : List_Id;
231 function Test_Component return List_Id;
232 -- Create one statement to test validity of one component designated by
233 -- a full set of indexes. Returns statement list containing test.
235 function Test_One_Dimension (N : Int) return List_Id;
236 -- Create loop to test one dimension of the array. The single statement
237 -- in the loop body tests the inner dimensions if any, or else the
238 -- single component. Note that this procedure is called recursively,
239 -- with N being the dimension to be initialized. A call with N greater
240 -- than the number of dimensions simply generates the component test,
241 -- terminating the recursion. Returns statement list containing tests.
247 function Test_Component return List_Id is
253 Make_Indexed_Component (Loc,
254 Prefix => Make_Identifier (Loc, Name_uA),
255 Expressions => Index_List);
257 if Is_Scalar_Type (Comp_Type) then
260 Anam := Name_Valid_Scalars;
264 Make_If_Statement (Loc,
268 Make_Attribute_Reference (Loc,
269 Attribute_Name => Anam,
271 Then_Statements => New_List (
272 Make_Simple_Return_Statement (Loc,
273 Expression => New_Occurrence_Of (Standard_False, Loc)))));
276 ------------------------
277 -- Test_One_Dimension --
278 ------------------------
280 function Test_One_Dimension (N : Int) return List_Id is
284 -- If all dimensions dealt with, we simply test the component
286 if N > Number_Dimensions (A_Type) then
287 return Test_Component;
289 -- Here we generate the required loop
293 Make_Defining_Identifier (Loc, New_External_Name ('J', N));
295 Append (New_Occurrence_Of (Index, Loc), Index_List);
298 Make_Implicit_Loop_Statement (Nod,
301 Make_Iteration_Scheme (Loc,
302 Loop_Parameter_Specification =>
303 Make_Loop_Parameter_Specification (Loc,
304 Defining_Identifier => Index,
305 Discrete_Subtype_Definition =>
306 Make_Attribute_Reference (Loc,
307 Prefix => Make_Identifier (Loc, Name_uA),
308 Attribute_Name => Name_Range,
309 Expressions => New_List (
310 Make_Integer_Literal (Loc, N))))),
311 Statements => Test_One_Dimension (N + 1)),
312 Make_Simple_Return_Statement (Loc,
313 Expression => New_Occurrence_Of (Standard_True, Loc)));
315 end Test_One_Dimension;
317 -- Start of processing for Build_Array_VS_Func
320 Index_List := New_List;
321 Body_Stmts := Test_One_Dimension (1);
323 -- Parameter is always (A : A_Typ)
325 Formals := New_List (
326 Make_Parameter_Specification (Loc,
327 Defining_Identifier => Make_Defining_Identifier (Loc, Name_uA),
329 Out_Present => False,
330 Parameter_Type => New_Occurrence_Of (A_Type, Loc)));
334 Set_Ekind (Func_Id, E_Function);
335 Set_Is_Internal (Func_Id);
338 Make_Subprogram_Body (Loc,
340 Make_Function_Specification (Loc,
341 Defining_Unit_Name => Func_Id,
342 Parameter_Specifications => Formals,
344 New_Occurrence_Of (Standard_Boolean, Loc)),
345 Declarations => New_List,
346 Handled_Statement_Sequence =>
347 Make_Handled_Sequence_Of_Statements (Loc,
348 Statements => Body_Stmts)));
350 if not Debug_Generated_Code then
351 Set_Debug_Info_Off (Func_Id);
354 Set_Is_Pure (Func_Id);
356 end Build_Array_VS_Func;
358 --------------------------
359 -- Build_Record_VS_Func --
360 --------------------------
364 -- function _Valid_Scalars (X : T) return Boolean is
366 -- -- Check discriminants
368 -- if not X.D1'Valid_Scalars or else
369 -- not X.D2'Valid_Scalars or else
375 -- -- Check components
377 -- if not X.C1'Valid_Scalars or else
378 -- not X.C2'Valid_Scalars or else
384 -- -- Check variant part
388 -- if not X.C2'Valid_Scalars or else
389 -- not X.C3'Valid_Scalars or else
396 -- if not X.Cn'Valid_Scalars or else
404 -- end _Valid_Scalars;
406 function Build_Record_VS_Func
408 Nod : Node_Id) return Entity_Id
410 Loc : constant Source_Ptr := Sloc (R_Type);
411 Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V');
412 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_X);
414 function Make_VS_Case
417 Discrs : Elist_Id := New_Elmt_List) return List_Id;
418 -- Building block for variant valid scalars. Given a Component_List node
419 -- CL, it generates an 'if' followed by a 'case' statement that compares
420 -- all components of local temporaries named X and Y (that are declared
421 -- as formals at some upper level). E provides the Sloc to be used for
422 -- the generated code.
426 L : List_Id) return Node_Id;
427 -- Building block for variant validate scalars. Given the list, L, of
428 -- components (or discriminants) L, it generates a return statement that
429 -- compares all components of local temporaries named X and Y (that are
430 -- declared as formals at some upper level). E provides the Sloc to be
431 -- used for the generated code.
437 -- <Make_VS_If on shared components>
440 -- when V1 => <Make_VS_Case> on subcomponents
442 -- when Vn => <Make_VS_Case> on subcomponents
445 function Make_VS_Case
448 Discrs : Elist_Id := New_Elmt_List) return List_Id
450 Loc : constant Source_Ptr := Sloc (E);
451 Result : constant List_Id := New_List;
456 Append_To (Result, Make_VS_If (E, Component_Items (CL)));
458 if No (Variant_Part (CL)) then
462 Variant := First_Non_Pragma (Variants (Variant_Part (CL)));
468 Alt_List := New_List;
469 while Present (Variant) loop
471 Make_Case_Statement_Alternative (Loc,
472 Discrete_Choices => New_Copy_List (Discrete_Choices (Variant)),
474 Make_VS_Case (E, Component_List (Variant), Discrs)));
475 Next_Non_Pragma (Variant);
479 Make_Case_Statement (Loc,
481 Make_Selected_Component (Loc,
482 Prefix => Make_Identifier (Loc, Name_X),
483 Selector_Name => New_Copy (Name (Variant_Part (CL)))),
484 Alternatives => Alt_List));
496 -- not X.C1'Valid_Scalars
498 -- not X.C2'Valid_Scalars
504 -- or a null statement if the list L is empty
508 L : List_Id) return Node_Id
510 Loc : constant Source_Ptr := Sloc (E);
513 Field_Name : Name_Id;
518 return Make_Null_Statement (Loc);
523 C := First_Non_Pragma (L);
524 while Present (C) loop
525 Def_Id := Defining_Identifier (C);
526 Field_Name := Chars (Def_Id);
528 -- The tags need not be checked since they will always be valid
530 -- Note also that in the following, we use Make_Identifier for
531 -- the component names. Use of New_Occurrence_Of to identify
532 -- the components would be incorrect because wrong entities for
533 -- discriminants could be picked up in the private type case.
535 -- Don't bother with abstract parent in interface case
537 if Field_Name = Name_uParent
538 and then Is_Interface (Etype (Def_Id))
542 -- Don't bother with tag, always valid, and not scalar anyway
544 elsif Field_Name = Name_uTag then
547 -- Don't bother with component with no scalar components
549 elsif not Scalar_Part_Present (Etype (Def_Id)) then
552 -- Normal case, generate Valid_Scalars attribute reference
555 Evolve_Or_Else (Cond,
558 Make_Attribute_Reference (Loc,
560 Make_Selected_Component (Loc,
562 Make_Identifier (Loc, Name_X),
564 Make_Identifier (Loc, Field_Name)),
565 Attribute_Name => Name_Valid_Scalars)));
572 return Make_Null_Statement (Loc);
576 Make_Implicit_If_Statement (E,
578 Then_Statements => New_List (
579 Make_Simple_Return_Statement (Loc,
581 New_Occurrence_Of (Standard_False, Loc))));
586 -- Local Declarations
588 Def : constant Node_Id := Parent (R_Type);
589 Comps : constant Node_Id := Component_List (Type_Definition (Def));
590 Stmts : constant List_Id := New_List;
591 Pspecs : constant List_Id := New_List;
595 Make_Parameter_Specification (Loc,
596 Defining_Identifier => X,
597 Parameter_Type => New_Occurrence_Of (R_Type, Loc)));
600 Make_VS_If (R_Type, Discriminant_Specifications (Def)));
601 Append_List_To (Stmts, Make_VS_Case (R_Type, Comps));
604 Make_Simple_Return_Statement (Loc,
605 Expression => New_Occurrence_Of (Standard_True, Loc)));
608 Make_Subprogram_Body (Loc,
610 Make_Function_Specification (Loc,
611 Defining_Unit_Name => Func_Id,
612 Parameter_Specifications => Pspecs,
613 Result_Definition => New_Occurrence_Of (Standard_Boolean, Loc)),
614 Declarations => New_List,
615 Handled_Statement_Sequence =>
616 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)),
617 Suppress => Discriminant_Check);
619 if not Debug_Generated_Code then
620 Set_Debug_Info_Off (Func_Id);
623 Set_Is_Pure (Func_Id);
625 end Build_Record_VS_Func;
627 ----------------------------------
628 -- Compile_Stream_Body_In_Scope --
629 ----------------------------------
631 procedure Compile_Stream_Body_In_Scope
637 C_Type : constant Entity_Id := Base_Type (Component_Type (Arr));
638 Curr : constant Entity_Id := Current_Scope;
639 Install : Boolean := False;
640 Scop : Entity_Id := Scope (Arr);
644 and then not In_Open_Scopes (Scop)
645 and then Ekind (Scop) = E_Package
650 -- The component type may be private, in which case we install its
651 -- full view to compile the subprogram.
653 -- The component type may be private, in which case we install its
654 -- full view to compile the subprogram. We do not do this if the
655 -- type has a Stream_Convert pragma, which indicates that there are
656 -- special stream-processing operations for that type (for example
657 -- Unbounded_String and its wide varieties).
659 Scop := Scope (C_Type);
661 if Is_Private_Type (C_Type)
662 and then Present (Full_View (C_Type))
663 and then not In_Open_Scopes (Scop)
664 and then Ekind (Scop) = E_Package
665 and then No (Get_Stream_Convert_Pragma (C_Type))
671 -- If we are within an instance body, then all visibility has been
672 -- established already and there is no need to install the package.
674 if Install and then not In_Instance_Body then
676 Install_Visible_Declarations (Scop);
677 Install_Private_Declarations (Scop);
679 -- The entities in the package are now visible, but the generated
680 -- stream entity must appear in the current scope (usually an
681 -- enclosing stream function) so that itypes all have their proper
690 Insert_Action (N, Decl);
692 Insert_Action (N, Decl, Suppress => All_Checks);
697 -- Remove extra copy of current scope, and package itself
700 End_Package_Scope (Scop);
702 end Compile_Stream_Body_In_Scope;
704 -----------------------------------
705 -- Expand_Access_To_Protected_Op --
706 -----------------------------------
708 procedure Expand_Access_To_Protected_Op
713 -- The value of the attribute_reference is a record containing two
714 -- fields: an access to the protected object, and an access to the
715 -- subprogram itself. The prefix is a selected component.
717 Loc : constant Source_Ptr := Sloc (N);
719 Btyp : constant Entity_Id := Base_Type (Typ);
722 E_T : constant Entity_Id := Equivalent_Type (Btyp);
723 Acc : constant Entity_Id :=
724 Etype (Next_Component (First_Component (E_T)));
728 -- Start of processing for Expand_Access_To_Protected_Op
731 -- Within the body of the protected type, the prefix designates a local
732 -- operation, and the object is the first parameter of the corresponding
733 -- protected body of the current enclosing operation.
735 if Is_Entity_Name (Pref) then
736 -- All indirect calls are external calls, so must do locking and
737 -- barrier reevaluation, even if the 'Access occurs within the
738 -- protected body. Hence the call to External_Subprogram, as opposed
739 -- to Protected_Body_Subprogram, below. See RM-9.5(5). This means
740 -- that indirect calls from within the same protected body will
741 -- deadlock, as allowed by RM-9.5.1(8,15,17).
743 Sub := New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc);
745 -- Don't traverse the scopes when the attribute occurs within an init
746 -- proc, because we directly use the _init formal of the init proc in
749 Curr := Current_Scope;
750 if not Is_Init_Proc (Curr) then
751 pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
753 while Scope (Curr) /= Scope (Entity (Pref)) loop
754 Curr := Scope (Curr);
758 -- In case of protected entries the first formal of its Protected_
759 -- Body_Subprogram is the address of the object.
761 if Ekind (Curr) = E_Entry then
765 (Protected_Body_Subprogram (Curr)), Loc);
767 -- If the current scope is an init proc, then use the address of the
768 -- _init formal as the object reference.
770 elsif Is_Init_Proc (Curr) then
772 Make_Attribute_Reference (Loc,
773 Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
774 Attribute_Name => Name_Address);
776 -- In case of protected subprograms the first formal of its
777 -- Protected_Body_Subprogram is the object and we get its address.
781 Make_Attribute_Reference (Loc,
785 (Protected_Body_Subprogram (Curr)), Loc),
786 Attribute_Name => Name_Address);
789 -- Case where the prefix is not an entity name. Find the
790 -- version of the protected operation to be called from
791 -- outside the protected object.
797 (Entity (Selector_Name (Pref))), Loc);
800 Make_Attribute_Reference (Loc,
801 Prefix => Relocate_Node (Prefix (Pref)),
802 Attribute_Name => Name_Address);
806 Make_Attribute_Reference (Loc,
808 Attribute_Name => Name_Access);
810 -- We set the type of the access reference to the already generated
811 -- access_to_subprogram type, and declare the reference analyzed, to
812 -- prevent further expansion when the enclosing aggregate is analyzed.
814 Set_Etype (Sub_Ref, Acc);
815 Set_Analyzed (Sub_Ref);
819 Expressions => New_List (Obj_Ref, Sub_Ref));
821 -- Sub_Ref has been marked as analyzed, but we still need to make sure
822 -- Sub is correctly frozen.
824 Freeze_Before (N, Entity (Sub));
827 Analyze_And_Resolve (N, E_T);
829 -- For subsequent analysis, the node must retain its type. The backend
830 -- will replace it with the equivalent type where needed.
833 end Expand_Access_To_Protected_Op;
835 --------------------------
836 -- Expand_Fpt_Attribute --
837 --------------------------
839 procedure Expand_Fpt_Attribute
845 Loc : constant Source_Ptr := Sloc (N);
846 Typ : constant Entity_Id := Etype (N);
850 -- The function name is the selected component Attr_xxx.yyy where
851 -- Attr_xxx is the package name, and yyy is the argument Nam.
853 -- Note: it would be more usual to have separate RE entries for each
854 -- of the entities in the Fat packages, but first they have identical
855 -- names (so we would have to have lots of renaming declarations to
856 -- meet the normal RE rule of separate names for all runtime entities),
857 -- and second there would be an awful lot of them.
860 Make_Selected_Component (Loc,
861 Prefix => New_Occurrence_Of (RTE (Pkg), Loc),
862 Selector_Name => Make_Identifier (Loc, Nam));
864 -- The generated call is given the provided set of parameters, and then
865 -- wrapped in a conversion which converts the result to the target type
866 -- We use the base type as the target because a range check may be
870 Unchecked_Convert_To (Base_Type (Etype (N)),
871 Make_Function_Call (Loc,
873 Parameter_Associations => Args)));
875 Analyze_And_Resolve (N, Typ);
876 end Expand_Fpt_Attribute;
878 ----------------------------
879 -- Expand_Fpt_Attribute_R --
880 ----------------------------
882 -- The single argument is converted to its root type to call the
883 -- appropriate runtime function, with the actual call being built
884 -- by Expand_Fpt_Attribute
886 procedure Expand_Fpt_Attribute_R (N : Node_Id) is
887 E1 : constant Node_Id := First (Expressions (N));
891 Find_Fat_Info (Etype (E1), Ftp, Pkg);
893 (N, Pkg, Attribute_Name (N),
894 New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
895 end Expand_Fpt_Attribute_R;
897 -----------------------------
898 -- Expand_Fpt_Attribute_RI --
899 -----------------------------
901 -- The first argument is converted to its root type and the second
902 -- argument is converted to standard long long integer to call the
903 -- appropriate runtime function, with the actual call being built
904 -- by Expand_Fpt_Attribute
906 procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
907 E1 : constant Node_Id := First (Expressions (N));
910 E2 : constant Node_Id := Next (E1);
912 Find_Fat_Info (Etype (E1), Ftp, Pkg);
914 (N, Pkg, Attribute_Name (N),
916 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
917 Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
918 end Expand_Fpt_Attribute_RI;
920 -----------------------------
921 -- Expand_Fpt_Attribute_RR --
922 -----------------------------
924 -- The two arguments are converted to their root types to call the
925 -- appropriate runtime function, with the actual call being built
926 -- by Expand_Fpt_Attribute
928 procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
929 E1 : constant Node_Id := First (Expressions (N));
930 E2 : constant Node_Id := Next (E1);
935 Find_Fat_Info (Etype (E1), Ftp, Pkg);
937 (N, Pkg, Attribute_Name (N),
939 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
940 Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
941 end Expand_Fpt_Attribute_RR;
943 ---------------------------------
944 -- Expand_Loop_Entry_Attribute --
945 ---------------------------------
947 procedure Expand_Loop_Entry_Attribute (N : Node_Id) is
948 procedure Build_Conditional_Block
952 If_Stmt : out Node_Id;
953 Blk_Stmt : out Node_Id);
954 -- Create a block Blk_Stmt with an empty declarative list and a single
955 -- loop Loop_Stmt. The block is encased in an if statement If_Stmt with
956 -- condition Cond. If_Stmt is Empty when there is no condition provided.
958 function Is_Array_Iteration (N : Node_Id) return Boolean;
959 -- Determine whether loop statement N denotes an Ada 2012 iteration over
962 -----------------------------
963 -- Build_Conditional_Block --
964 -----------------------------
966 procedure Build_Conditional_Block
970 If_Stmt : out Node_Id;
971 Blk_Stmt : out Node_Id)
974 -- Do not reanalyze the original loop statement because it is simply
977 Set_Analyzed (Loop_Stmt);
980 Make_Block_Statement (Loc,
981 Declarations => New_List,
982 Handled_Statement_Sequence =>
983 Make_Handled_Sequence_Of_Statements (Loc,
984 Statements => New_List (Loop_Stmt)));
986 if Present (Cond) then
988 Make_If_Statement (Loc,
990 Then_Statements => New_List (Blk_Stmt));
994 end Build_Conditional_Block;
996 ------------------------
997 -- Is_Array_Iteration --
998 ------------------------
1000 function Is_Array_Iteration (N : Node_Id) return Boolean is
1001 Stmt : constant Node_Id := Original_Node (N);
1005 if Nkind (Stmt) = N_Loop_Statement
1006 and then Present (Iteration_Scheme (Stmt))
1007 and then Present (Iterator_Specification (Iteration_Scheme (Stmt)))
1009 Iter := Iterator_Specification (Iteration_Scheme (Stmt));
1012 Of_Present (Iter) and then Is_Array_Type (Etype (Name (Iter)));
1016 end Is_Array_Iteration;
1020 Exprs : constant List_Id := Expressions (N);
1021 Pref : constant Node_Id := Prefix (N);
1022 Typ : constant Entity_Id := Etype (Pref);
1025 CW_Temp : Entity_Id;
1028 Installed : Boolean;
1030 Loop_Id : Entity_Id;
1031 Loop_Stmt : Node_Id;
1034 Temp_Decl : Node_Id;
1035 Temp_Id : Entity_Id;
1037 -- Start of processing for Expand_Loop_Entry_Attribute
1040 -- Step 1: Find the related loop
1042 -- The loop label variant of attribute 'Loop_Entry already has all the
1043 -- information in its expression.
1045 if Present (Exprs) then
1046 Loop_Id := Entity (First (Exprs));
1047 Loop_Stmt := Label_Construct (Parent (Loop_Id));
1049 -- Climb the parent chain to find the nearest enclosing loop. Skip all
1050 -- internally generated loops for quantified expressions and for
1051 -- element iterators over multidimensional arrays: pragma applies to
1056 while Present (Loop_Stmt) loop
1057 if Nkind (Loop_Stmt) = N_Loop_Statement
1058 and then Comes_From_Source (Loop_Stmt)
1063 Loop_Stmt := Parent (Loop_Stmt);
1066 Loop_Id := Entity (Identifier (Loop_Stmt));
1069 Loc := Sloc (Loop_Stmt);
1071 -- Step 2: Transform the loop
1073 -- The loop has already been transformed during the expansion of a prior
1074 -- 'Loop_Entry attribute. Retrieve the declarative list of the block.
1076 if Has_Loop_Entry_Attributes (Loop_Id) then
1078 -- When the related loop name appears as the argument of attribute
1079 -- Loop_Entry, the corresponding label construct is the generated
1080 -- block statement. This is because the expander reuses the label.
1082 if Nkind (Loop_Stmt) = N_Block_Statement then
1083 Decls := Declarations (Loop_Stmt);
1085 -- In all other cases, the loop must appear in the handled sequence
1086 -- of statements of the generated block.
1090 (Nkind (Parent (Loop_Stmt)) = N_Handled_Sequence_Of_Statements
1092 Nkind (Parent (Parent (Loop_Stmt))) = N_Block_Statement);
1094 Decls := Declarations (Parent (Parent (Loop_Stmt)));
1099 -- Transform the loop into a conditional block
1102 Set_Has_Loop_Entry_Attributes (Loop_Id);
1103 Scheme := Iteration_Scheme (Loop_Stmt);
1105 -- Infinite loops are transformed into:
1108 -- Temp1 : constant <type of Pref1> := <Pref1>;
1110 -- TempN : constant <type of PrefN> := <PrefN>;
1113 -- <original source statements with attribute rewrites>
1118 Build_Conditional_Block (Loc,
1120 Loop_Stmt => Relocate_Node (Loop_Stmt),
1126 -- While loops are transformed into:
1128 -- function Fnn return Boolean is
1130 -- <condition actions>
1131 -- return <condition>;
1136 -- Temp1 : constant <type of Pref1> := <Pref1>;
1138 -- TempN : constant <type of PrefN> := <PrefN>;
1141 -- <original source statements with attribute rewrites>
1142 -- exit when not Fnn;
1147 -- Note that loops over iterators and containers are already
1148 -- converted into while loops.
1150 elsif Present (Condition (Scheme)) then
1152 Func_Decl : Node_Id;
1153 Func_Id : Entity_Id;
1157 -- Wrap the condition of the while loop in a Boolean function.
1158 -- This avoids the duplication of the same code which may lead
1159 -- to gigi issues with respect to multiple declaration of the
1160 -- same entity in the presence of side effects or checks. Note
1161 -- that the condition actions must also be relocated to the
1162 -- wrapping function.
1165 -- <condition actions>
1166 -- return <condition>;
1168 if Present (Condition_Actions (Scheme)) then
1169 Stmts := Condition_Actions (Scheme);
1175 Make_Simple_Return_Statement (Loc,
1176 Expression => Relocate_Node (Condition (Scheme))));
1179 -- function Fnn return Boolean is
1184 Func_Id := Make_Temporary (Loc, 'F');
1186 Make_Subprogram_Body (Loc,
1188 Make_Function_Specification (Loc,
1189 Defining_Unit_Name => Func_Id,
1190 Result_Definition =>
1191 New_Occurrence_Of (Standard_Boolean, Loc)),
1192 Declarations => Empty_List,
1193 Handled_Statement_Sequence =>
1194 Make_Handled_Sequence_Of_Statements (Loc,
1195 Statements => Stmts));
1197 -- The function is inserted before the related loop. Make sure
1198 -- to analyze it in the context of the loop's enclosing scope.
1200 Push_Scope (Scope (Loop_Id));
1201 Insert_Action (Loop_Stmt, Func_Decl);
1204 -- Transform the original while loop into an infinite loop
1205 -- where the last statement checks the negated condition. This
1206 -- placement ensures that the condition will not be evaluated
1207 -- twice on the first iteration.
1209 Set_Iteration_Scheme (Loop_Stmt, Empty);
1213 -- exit when not Fnn;
1215 Append_To (Statements (Loop_Stmt),
1216 Make_Exit_Statement (Loc,
1220 Make_Function_Call (Loc,
1221 Name => New_Occurrence_Of (Func_Id, Loc)))));
1223 Build_Conditional_Block (Loc,
1225 Make_Function_Call (Loc,
1226 Name => New_Occurrence_Of (Func_Id, Loc)),
1227 Loop_Stmt => Relocate_Node (Loop_Stmt),
1232 -- Ada 2012 iteration over an array is transformed into:
1234 -- if <Array_Nam>'Length (1) > 0
1235 -- and then <Array_Nam>'Length (N) > 0
1238 -- Temp1 : constant <type of Pref1> := <Pref1>;
1240 -- TempN : constant <type of PrefN> := <PrefN>;
1242 -- for X in ... loop -- multiple loops depending on dims
1243 -- <original source statements with attribute rewrites>
1248 elsif Is_Array_Iteration (Loop_Stmt) then
1250 Array_Nam : constant Entity_Id :=
1251 Entity (Name (Iterator_Specification
1252 (Iteration_Scheme (Original_Node (Loop_Stmt)))));
1253 Num_Dims : constant Pos :=
1254 Number_Dimensions (Etype (Array_Nam));
1255 Cond : Node_Id := Empty;
1259 -- Generate a check which determines whether all dimensions of
1260 -- the array are non-null.
1262 for Dim in 1 .. Num_Dims loop
1266 Make_Attribute_Reference (Loc,
1267 Prefix => New_Occurrence_Of (Array_Nam, Loc),
1268 Attribute_Name => Name_Length,
1269 Expressions => New_List (
1270 Make_Integer_Literal (Loc, Dim))),
1272 Make_Integer_Literal (Loc, 0));
1280 Right_Opnd => Check);
1284 Build_Conditional_Block (Loc,
1286 Loop_Stmt => Relocate_Node (Loop_Stmt),
1291 -- For loops are transformed into:
1293 -- if <Low> <= <High> then
1295 -- Temp1 : constant <type of Pref1> := <Pref1>;
1297 -- TempN : constant <type of PrefN> := <PrefN>;
1299 -- for <Def_Id> in <Low> .. <High> loop
1300 -- <original source statements with attribute rewrites>
1305 elsif Present (Loop_Parameter_Specification (Scheme)) then
1307 Loop_Spec : constant Node_Id :=
1308 Loop_Parameter_Specification (Scheme);
1313 Subt_Def := Discrete_Subtype_Definition (Loop_Spec);
1315 -- When the loop iterates over a subtype indication with a
1316 -- range, use the low and high bounds of the subtype itself.
1318 if Nkind (Subt_Def) = N_Subtype_Indication then
1319 Subt_Def := Scalar_Range (Etype (Subt_Def));
1322 pragma Assert (Nkind (Subt_Def) = N_Range);
1329 Left_Opnd => New_Copy_Tree (Low_Bound (Subt_Def)),
1330 Right_Opnd => New_Copy_Tree (High_Bound (Subt_Def)));
1332 Build_Conditional_Block (Loc,
1334 Loop_Stmt => Relocate_Node (Loop_Stmt),
1340 Decls := Declarations (Blk);
1343 -- Step 3: Create a constant to capture the value of the prefix at the
1344 -- entry point into the loop.
1346 Temp_Id := Make_Temporary (Loc, 'P');
1348 -- Preserve the tag of the prefix by offering a specific view of the
1349 -- class-wide version of the prefix.
1351 if Is_Tagged_Type (Typ) then
1354 -- CW_Temp : constant Typ'Class := Typ'Class (Pref);
1356 CW_Temp := Make_Temporary (Loc, 'T');
1357 CW_Typ := Class_Wide_Type (Typ);
1360 Make_Object_Declaration (Loc,
1361 Defining_Identifier => CW_Temp,
1362 Constant_Present => True,
1363 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
1365 Convert_To (CW_Typ, Relocate_Node (Pref)));
1366 Append_To (Decls, CW_Decl);
1369 -- Temp : Typ renames Typ (CW_Temp);
1372 Make_Object_Renaming_Declaration (Loc,
1373 Defining_Identifier => Temp_Id,
1374 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
1376 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc)));
1377 Append_To (Decls, Temp_Decl);
1385 -- Temp : constant Typ := Pref;
1388 Make_Object_Declaration (Loc,
1389 Defining_Identifier => Temp_Id,
1390 Constant_Present => True,
1391 Object_Definition => New_Occurrence_Of (Typ, Loc),
1392 Expression => Relocate_Node (Pref));
1393 Append_To (Decls, Temp_Decl);
1396 -- Step 4: Analyze all bits
1398 Installed := Current_Scope = Scope (Loop_Id);
1400 -- Depending on the pracement of attribute 'Loop_Entry relative to the
1401 -- associated loop, ensure the proper visibility for analysis.
1403 if not Installed then
1404 Push_Scope (Scope (Loop_Id));
1407 -- The analysis of the conditional block takes care of the constant
1410 if Present (Result) then
1411 Rewrite (Loop_Stmt, Result);
1412 Analyze (Loop_Stmt);
1414 -- The conditional block was analyzed when a previous 'Loop_Entry was
1415 -- expanded. There is no point in reanalyzing the block, simply analyze
1416 -- the declaration of the constant.
1419 if Present (CW_Decl) then
1423 Analyze (Temp_Decl);
1426 Rewrite (N, New_Occurrence_Of (Temp_Id, Loc));
1429 if not Installed then
1432 end Expand_Loop_Entry_Attribute;
1434 ------------------------------
1435 -- Expand_Min_Max_Attribute --
1436 ------------------------------
1438 procedure Expand_Min_Max_Attribute (N : Node_Id) is
1440 -- Min and Max are handled by the back end (except that static cases
1441 -- have already been evaluated during semantic processing, although the
1442 -- back end should not count on this). The one bit of special processing
1443 -- required in the normal case is that these two attributes typically
1444 -- generate conditionals in the code, so check the relevant restriction.
1446 Check_Restriction (No_Implicit_Conditionals, N);
1448 -- In Modify_Tree_For_C mode, we rewrite as an if expression
1450 if Modify_Tree_For_C then
1452 Loc : constant Source_Ptr := Sloc (N);
1453 Typ : constant Entity_Id := Etype (N);
1454 Expr : constant Node_Id := First (Expressions (N));
1455 Left : constant Node_Id := Relocate_Node (Expr);
1456 Right : constant Node_Id := Relocate_Node (Next (Expr));
1458 function Make_Compare (Left, Right : Node_Id) return Node_Id;
1459 -- Returns Left >= Right for Max, Left <= Right for Min
1465 function Make_Compare (Left, Right : Node_Id) return Node_Id is
1467 if Attribute_Name (N) = Name_Max then
1471 Right_Opnd => Right);
1476 Right_Opnd => Right);
1480 -- Start of processing for Min_Max
1483 -- If both Left and Right are side effect free, then we can just
1484 -- use Duplicate_Expr to duplicate the references and return
1486 -- (if Left >=|<= Right then Left else Right)
1488 if Side_Effect_Free (Left) and then Side_Effect_Free (Right) then
1490 Make_If_Expression (Loc,
1491 Expressions => New_List (
1492 Make_Compare (Left, Right),
1493 Duplicate_Subexpr_No_Checks (Left),
1494 Duplicate_Subexpr_No_Checks (Right))));
1496 -- Otherwise we generate declarations to capture the values.
1498 -- The translation is
1501 -- T1 : constant typ := Left;
1502 -- T2 : constant typ := Right;
1504 -- (if T1 >=|<= T2 then T1 else T2)
1509 T1 : constant Entity_Id := Make_Temporary (Loc, 'T', Left);
1510 T2 : constant Entity_Id := Make_Temporary (Loc, 'T', Right);
1514 Make_Expression_With_Actions (Loc,
1515 Actions => New_List (
1516 Make_Object_Declaration (Loc,
1517 Defining_Identifier => T1,
1518 Constant_Present => True,
1519 Object_Definition =>
1520 New_Occurrence_Of (Etype (Left), Loc),
1521 Expression => Relocate_Node (Left)),
1523 Make_Object_Declaration (Loc,
1524 Defining_Identifier => T2,
1525 Constant_Present => True,
1526 Object_Definition =>
1527 New_Occurrence_Of (Etype (Right), Loc),
1528 Expression => Relocate_Node (Right))),
1531 Make_If_Expression (Loc,
1532 Expressions => New_List (
1534 (New_Occurrence_Of (T1, Loc),
1535 New_Occurrence_Of (T2, Loc)),
1536 New_Occurrence_Of (T1, Loc),
1537 New_Occurrence_Of (T2, Loc)))));
1541 Analyze_And_Resolve (N, Typ);
1544 end Expand_Min_Max_Attribute;
1546 ----------------------------------
1547 -- Expand_N_Attribute_Reference --
1548 ----------------------------------
1550 procedure Expand_N_Attribute_Reference (N : Node_Id) is
1551 Loc : constant Source_Ptr := Sloc (N);
1552 Typ : constant Entity_Id := Etype (N);
1553 Btyp : constant Entity_Id := Base_Type (Typ);
1554 Pref : constant Node_Id := Prefix (N);
1555 Ptyp : constant Entity_Id := Etype (Pref);
1556 Exprs : constant List_Id := Expressions (N);
1557 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
1559 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
1560 -- Rewrites a stream attribute for Read, Write or Output with the
1561 -- procedure call. Pname is the entity for the procedure to call.
1563 ------------------------------
1564 -- Rewrite_Stream_Proc_Call --
1565 ------------------------------
1567 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
1568 Item : constant Node_Id := Next (First (Exprs));
1569 Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
1570 Formal_Typ : constant Entity_Id := Etype (Formal);
1571 Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
1574 -- The expansion depends on Item, the second actual, which is
1575 -- the object being streamed in or out.
1577 -- If the item is a component of a packed array type, and
1578 -- a conversion is needed on exit, we introduce a temporary to
1579 -- hold the value, because otherwise the packed reference will
1580 -- not be properly expanded.
1582 if Nkind (Item) = N_Indexed_Component
1583 and then Is_Packed (Base_Type (Etype (Prefix (Item))))
1584 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
1588 Temp : constant Entity_Id := Make_Temporary (Loc, 'V');
1594 Make_Object_Declaration (Loc,
1595 Defining_Identifier => Temp,
1596 Object_Definition =>
1597 New_Occurrence_Of (Formal_Typ, Loc));
1598 Set_Etype (Temp, Formal_Typ);
1601 Make_Assignment_Statement (Loc,
1602 Name => New_Copy_Tree (Item),
1604 Unchecked_Convert_To
1605 (Etype (Item), New_Occurrence_Of (Temp, Loc)));
1607 Rewrite (Item, New_Occurrence_Of (Temp, Loc));
1611 Make_Procedure_Call_Statement (Loc,
1612 Name => New_Occurrence_Of (Pname, Loc),
1613 Parameter_Associations => Exprs),
1616 Rewrite (N, Make_Null_Statement (Loc));
1621 -- For the class-wide dispatching cases, and for cases in which
1622 -- the base type of the second argument matches the base type of
1623 -- the corresponding formal parameter (that is to say the stream
1624 -- operation is not inherited), we are all set, and can use the
1625 -- argument unchanged.
1627 -- For all other cases we do an unchecked conversion of the second
1628 -- parameter to the type of the formal of the procedure we are
1629 -- calling. This deals with the private type cases, and with going
1630 -- to the root type as required in elementary type case.
1632 if not Is_Class_Wide_Type (Entity (Pref))
1633 and then not Is_Class_Wide_Type (Etype (Item))
1634 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
1637 Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
1639 -- For untagged derived types set Assignment_OK, to prevent
1640 -- copies from being created when the unchecked conversion
1641 -- is expanded (which would happen in Remove_Side_Effects
1642 -- if Expand_N_Unchecked_Conversion were allowed to call
1643 -- Force_Evaluation). The copy could violate Ada semantics in
1644 -- cases such as an actual that is an out parameter. Note that
1645 -- this approach is also used in exp_ch7 for calls to controlled
1646 -- type operations to prevent problems with actuals wrapped in
1647 -- unchecked conversions.
1649 if Is_Untagged_Derivation (Etype (Expression (Item))) then
1650 Set_Assignment_OK (Item);
1654 -- The stream operation to call may be a renaming created by an
1655 -- attribute definition clause, and may not be frozen yet. Ensure
1656 -- that it has the necessary extra formals.
1658 if not Is_Frozen (Pname) then
1659 Create_Extra_Formals (Pname);
1662 -- And now rewrite the call
1665 Make_Procedure_Call_Statement (Loc,
1666 Name => New_Occurrence_Of (Pname, Loc),
1667 Parameter_Associations => Exprs));
1670 end Rewrite_Stream_Proc_Call;
1672 -- Start of processing for Expand_N_Attribute_Reference
1675 -- Do required validity checking, if enabled. Do not apply check to
1676 -- output parameters of an Asm instruction, since the value of this
1677 -- is not set till after the attribute has been elaborated, and do
1678 -- not apply the check to the arguments of a 'Read or 'Input attribute
1679 -- reference since the scalar argument is an OUT scalar.
1681 if Validity_Checks_On and then Validity_Check_Operands
1682 and then Id /= Attribute_Asm_Output
1683 and then Id /= Attribute_Read
1684 and then Id /= Attribute_Input
1689 Expr := First (Expressions (N));
1690 while Present (Expr) loop
1691 Ensure_Valid (Expr);
1697 -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in-
1698 -- place function, then a temporary return object needs to be created
1699 -- and access to it must be passed to the function. Currently we limit
1700 -- such functions to those with inherently limited result subtypes, but
1701 -- eventually we plan to expand the functions that are treated as
1702 -- build-in-place to include other composite result types.
1704 if Ada_Version >= Ada_2005
1705 and then Is_Build_In_Place_Function_Call (Pref)
1707 Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
1710 -- If prefix is a protected type name, this is a reference to the
1711 -- current instance of the type. For a component definition, nothing
1712 -- to do (expansion will occur in the init proc). In other contexts,
1713 -- rewrite into reference to current instance.
1715 if Is_Protected_Self_Reference (Pref)
1717 (Nkind_In (Parent (N), N_Index_Or_Discriminant_Constraint,
1718 N_Discriminant_Association)
1719 and then Nkind (Parent (Parent (Parent (Parent (N))))) =
1720 N_Component_Definition)
1722 -- No action needed for these attributes since the current instance
1723 -- will be rewritten to be the name of the _object parameter
1724 -- associated with the enclosing protected subprogram (see below).
1726 and then Id /= Attribute_Access
1727 and then Id /= Attribute_Unchecked_Access
1728 and then Id /= Attribute_Unrestricted_Access
1730 Rewrite (Pref, Concurrent_Ref (Pref));
1734 -- Remaining processing depends on specific attribute
1736 -- Note: individual sections of the following case statement are
1737 -- allowed to assume there is no code after the case statement, and
1738 -- are legitimately allowed to execute return statements if they have
1739 -- nothing more to do.
1743 -- Attributes related to Ada 2012 iterators
1745 when Attribute_Constant_Indexing |
1746 Attribute_Default_Iterator |
1747 Attribute_Implicit_Dereference |
1748 Attribute_Iterable |
1749 Attribute_Iterator_Element |
1750 Attribute_Variable_Indexing =>
1753 -- Internal attributes used to deal with Ada 2012 delayed aspects. These
1754 -- were already rejected by the parser. Thus they shouldn't appear here.
1756 when Internal_Attribute_Id =>
1757 raise Program_Error;
1763 when Attribute_Access |
1764 Attribute_Unchecked_Access |
1765 Attribute_Unrestricted_Access =>
1767 Access_Cases : declare
1768 Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
1769 Btyp_DDT : Entity_Id;
1771 function Enclosing_Object (N : Node_Id) return Node_Id;
1772 -- If N denotes a compound name (selected component, indexed
1773 -- component, or slice), returns the name of the outermost such
1774 -- enclosing object. Otherwise returns N. If the object is a
1775 -- renaming, then the renamed object is returned.
1777 ----------------------
1778 -- Enclosing_Object --
1779 ----------------------
1781 function Enclosing_Object (N : Node_Id) return Node_Id is
1786 while Nkind_In (Obj_Name, N_Selected_Component,
1787 N_Indexed_Component,
1790 Obj_Name := Prefix (Obj_Name);
1793 return Get_Referenced_Object (Obj_Name);
1794 end Enclosing_Object;
1796 -- Local declarations
1798 Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
1800 -- Start of processing for Access_Cases
1803 Btyp_DDT := Designated_Type (Btyp);
1805 -- Handle designated types that come from the limited view
1807 if From_Limited_With (Btyp_DDT)
1808 and then Has_Non_Limited_View (Btyp_DDT)
1810 Btyp_DDT := Non_Limited_View (Btyp_DDT);
1813 -- In order to improve the text of error messages, the designated
1814 -- type of access-to-subprogram itypes is set by the semantics as
1815 -- the associated subprogram entity (see sem_attr). Now we replace
1816 -- such node with the proper E_Subprogram_Type itype.
1818 if Id = Attribute_Unrestricted_Access
1819 and then Is_Subprogram (Directly_Designated_Type (Typ))
1821 -- The following conditions ensure that this special management
1822 -- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
1823 -- At this stage other cases in which the designated type is
1824 -- still a subprogram (instead of an E_Subprogram_Type) are
1825 -- wrong because the semantics must have overridden the type of
1826 -- the node with the type imposed by the context.
1828 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
1829 and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
1831 Set_Etype (N, RTE (RE_Prim_Ptr));
1835 Subp : constant Entity_Id :=
1836 Directly_Designated_Type (Typ);
1838 Extra : Entity_Id := Empty;
1839 New_Formal : Entity_Id;
1840 Old_Formal : Entity_Id := First_Formal (Subp);
1841 Subp_Typ : Entity_Id;
1844 Subp_Typ := Create_Itype (E_Subprogram_Type, N);
1845 Set_Etype (Subp_Typ, Etype (Subp));
1846 Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
1848 if Present (Old_Formal) then
1849 New_Formal := New_Copy (Old_Formal);
1850 Set_First_Entity (Subp_Typ, New_Formal);
1853 Set_Scope (New_Formal, Subp_Typ);
1854 Etyp := Etype (New_Formal);
1856 -- Handle itypes. There is no need to duplicate
1857 -- here the itypes associated with record types
1858 -- (i.e the implicit full view of private types).
1861 and then Ekind (Base_Type (Etyp)) /= E_Record_Type
1863 Extra := New_Copy (Etyp);
1864 Set_Parent (Extra, New_Formal);
1865 Set_Etype (New_Formal, Extra);
1866 Set_Scope (Extra, Subp_Typ);
1869 Extra := New_Formal;
1870 Next_Formal (Old_Formal);
1871 exit when No (Old_Formal);
1873 Set_Next_Entity (New_Formal,
1874 New_Copy (Old_Formal));
1875 Next_Entity (New_Formal);
1878 Set_Next_Entity (New_Formal, Empty);
1879 Set_Last_Entity (Subp_Typ, Extra);
1882 -- Now that the explicit formals have been duplicated,
1883 -- any extra formals needed by the subprogram must be
1886 if Present (Extra) then
1887 Set_Extra_Formal (Extra, Empty);
1890 Create_Extra_Formals (Subp_Typ);
1891 Set_Directly_Designated_Type (Typ, Subp_Typ);
1896 if Is_Access_Protected_Subprogram_Type (Btyp) then
1897 Expand_Access_To_Protected_Op (N, Pref, Typ);
1899 -- If prefix is a type name, this is a reference to the current
1900 -- instance of the type, within its initialization procedure.
1902 elsif Is_Entity_Name (Pref)
1903 and then Is_Type (Entity (Pref))
1910 -- If the current instance name denotes a task type, then
1911 -- the access attribute is rewritten to be the name of the
1912 -- "_task" parameter associated with the task type's task
1913 -- procedure. An unchecked conversion is applied to ensure
1914 -- a type match in cases of expander-generated calls (e.g.
1917 if Is_Task_Type (Entity (Pref)) then
1919 First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
1920 while Present (Formal) loop
1921 exit when Chars (Formal) = Name_uTask;
1922 Next_Entity (Formal);
1925 pragma Assert (Present (Formal));
1928 Unchecked_Convert_To (Typ,
1929 New_Occurrence_Of (Formal, Loc)));
1932 elsif Is_Protected_Type (Entity (Pref)) then
1934 -- No action needed for current instance located in a
1935 -- component definition (expansion will occur in the
1938 if Is_Protected_Type (Current_Scope) then
1941 -- If the current instance reference is located in a
1942 -- protected subprogram or entry then rewrite the access
1943 -- attribute to be the name of the "_object" parameter.
1944 -- An unchecked conversion is applied to ensure a type
1945 -- match in cases of expander-generated calls (e.g. init
1948 -- The code may be nested in a block, so find enclosing
1949 -- scope that is a protected operation.
1956 Subp := Current_Scope;
1957 while Ekind_In (Subp, E_Loop, E_Block) loop
1958 Subp := Scope (Subp);
1963 (Protected_Body_Subprogram (Subp));
1965 -- For a protected subprogram the _Object parameter
1966 -- is the protected record, so we create an access
1967 -- to it. The _Object parameter of an entry is an
1970 if Ekind (Subp) = E_Entry then
1972 Unchecked_Convert_To (Typ,
1973 New_Occurrence_Of (Formal, Loc)));
1978 Unchecked_Convert_To (Typ,
1979 Make_Attribute_Reference (Loc,
1980 Attribute_Name => Name_Unrestricted_Access,
1982 New_Occurrence_Of (Formal, Loc))));
1983 Analyze_And_Resolve (N);
1988 -- The expression must appear in a default expression,
1989 -- (which in the initialization procedure is the right-hand
1990 -- side of an assignment), and not in a discriminant
1995 while Present (Par) loop
1996 exit when Nkind (Par) = N_Assignment_Statement;
1998 if Nkind (Par) = N_Component_Declaration then
2002 Par := Parent (Par);
2005 if Present (Par) then
2007 Make_Attribute_Reference (Loc,
2008 Prefix => Make_Identifier (Loc, Name_uInit),
2009 Attribute_Name => Attribute_Name (N)));
2011 Analyze_And_Resolve (N, Typ);
2016 -- If the prefix of an Access attribute is a dereference of an
2017 -- access parameter (or a renaming of such a dereference, or a
2018 -- subcomponent of such a dereference) and the context is a
2019 -- general access type (including the type of an object or
2020 -- component with an access_definition, but not the anonymous
2021 -- type of an access parameter or access discriminant), then
2022 -- apply an accessibility check to the access parameter. We used
2023 -- to rewrite the access parameter as a type conversion, but that
2024 -- could only be done if the immediate prefix of the Access
2025 -- attribute was the dereference, and didn't handle cases where
2026 -- the attribute is applied to a subcomponent of the dereference,
2027 -- since there's generally no available, appropriate access type
2028 -- to convert to in that case. The attribute is passed as the
2029 -- point to insert the check, because the access parameter may
2030 -- come from a renaming, possibly in a different scope, and the
2031 -- check must be associated with the attribute itself.
2033 elsif Id = Attribute_Access
2034 and then Nkind (Enc_Object) = N_Explicit_Dereference
2035 and then Is_Entity_Name (Prefix (Enc_Object))
2036 and then (Ekind (Btyp) = E_General_Access_Type
2037 or else Is_Local_Anonymous_Access (Btyp))
2038 and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
2039 and then Ekind (Etype (Entity (Prefix (Enc_Object))))
2040 = E_Anonymous_Access_Type
2041 and then Present (Extra_Accessibility
2042 (Entity (Prefix (Enc_Object))))
2044 Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
2046 -- Ada 2005 (AI-251): If the designated type is an interface we
2047 -- add an implicit conversion to force the displacement of the
2048 -- pointer to reference the secondary dispatch table.
2050 elsif Is_Interface (Btyp_DDT)
2051 and then (Comes_From_Source (N)
2052 or else Comes_From_Source (Ref_Object)
2053 or else (Nkind (Ref_Object) in N_Has_Chars
2054 and then Chars (Ref_Object) = Name_uInit))
2056 if Nkind (Ref_Object) /= N_Explicit_Dereference then
2058 -- No implicit conversion required if types match, or if
2059 -- the prefix is the class_wide_type of the interface. In
2060 -- either case passing an object of the interface type has
2061 -- already set the pointer correctly.
2063 if Btyp_DDT = Etype (Ref_Object)
2064 or else (Is_Class_Wide_Type (Etype (Ref_Object))
2066 Class_Wide_Type (Btyp_DDT) = Etype (Ref_Object))
2071 Rewrite (Prefix (N),
2072 Convert_To (Btyp_DDT,
2073 New_Copy_Tree (Prefix (N))));
2075 Analyze_And_Resolve (Prefix (N), Btyp_DDT);
2078 -- When the object is an explicit dereference, convert the
2079 -- dereference's prefix.
2083 Obj_DDT : constant Entity_Id :=
2085 (Directly_Designated_Type
2086 (Etype (Prefix (Ref_Object))));
2088 -- No implicit conversion required if designated types
2089 -- match, or if we have an unrestricted access.
2091 if Obj_DDT /= Btyp_DDT
2092 and then Id /= Attribute_Unrestricted_Access
2093 and then not (Is_Class_Wide_Type (Obj_DDT)
2094 and then Etype (Obj_DDT) = Btyp_DDT)
2098 New_Copy_Tree (Prefix (Ref_Object))));
2099 Analyze_And_Resolve (N, Typ);
2110 -- Transforms 'Adjacent into a call to the floating-point attribute
2111 -- function Adjacent in Fat_xxx (where xxx is the root type)
2113 when Attribute_Adjacent =>
2114 Expand_Fpt_Attribute_RR (N);
2120 when Attribute_Address => Address : declare
2121 Task_Proc : Entity_Id;
2124 -- If the prefix is a task or a task type, the useful address is that
2125 -- of the procedure for the task body, i.e. the actual program unit.
2126 -- We replace the original entity with that of the procedure.
2128 if Is_Entity_Name (Pref)
2129 and then Is_Task_Type (Entity (Pref))
2131 Task_Proc := Next_Entity (Root_Type (Ptyp));
2133 while Present (Task_Proc) loop
2134 exit when Ekind (Task_Proc) = E_Procedure
2135 and then Etype (First_Formal (Task_Proc)) =
2136 Corresponding_Record_Type (Ptyp);
2137 Next_Entity (Task_Proc);
2140 if Present (Task_Proc) then
2141 Set_Entity (Pref, Task_Proc);
2142 Set_Etype (Pref, Etype (Task_Proc));
2145 -- Similarly, the address of a protected operation is the address
2146 -- of the corresponding protected body, regardless of the protected
2147 -- object from which it is selected.
2149 elsif Nkind (Pref) = N_Selected_Component
2150 and then Is_Subprogram (Entity (Selector_Name (Pref)))
2151 and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
2155 External_Subprogram (Entity (Selector_Name (Pref))), Loc));
2157 elsif Nkind (Pref) = N_Explicit_Dereference
2158 and then Ekind (Ptyp) = E_Subprogram_Type
2159 and then Convention (Ptyp) = Convention_Protected
2161 -- The prefix is be a dereference of an access_to_protected_
2162 -- subprogram. The desired address is the second component of
2163 -- the record that represents the access.
2166 Addr : constant Entity_Id := Etype (N);
2167 Ptr : constant Node_Id := Prefix (Pref);
2168 T : constant Entity_Id :=
2169 Equivalent_Type (Base_Type (Etype (Ptr)));
2173 Unchecked_Convert_To (Addr,
2174 Make_Selected_Component (Loc,
2175 Prefix => Unchecked_Convert_To (T, Ptr),
2176 Selector_Name => New_Occurrence_Of (
2177 Next_Entity (First_Entity (T)), Loc))));
2179 Analyze_And_Resolve (N, Addr);
2182 -- Ada 2005 (AI-251): Class-wide interface objects are always
2183 -- "displaced" to reference the tag associated with the interface
2184 -- type. In order to obtain the real address of such objects we
2185 -- generate a call to a run-time subprogram that returns the base
2186 -- address of the object.
2188 -- This processing is not needed in the VM case, where dispatching
2189 -- issues are taken care of by the virtual machine.
2191 elsif Is_Class_Wide_Type (Ptyp)
2192 and then Is_Interface (Ptyp)
2193 and then Tagged_Type_Expansion
2194 and then not (Nkind (Pref) in N_Has_Entity
2195 and then Is_Subprogram (Entity (Pref)))
2198 Make_Function_Call (Loc,
2199 Name => New_Occurrence_Of (RTE (RE_Base_Address), Loc),
2200 Parameter_Associations => New_List (
2201 Relocate_Node (N))));
2206 -- Deal with packed array reference, other cases are handled by
2209 if Involves_Packed_Array_Reference (Pref) then
2210 Expand_Packed_Address_Reference (N);
2218 when Attribute_Alignment => Alignment : declare
2222 -- For class-wide types, X'Class'Alignment is transformed into a
2223 -- direct reference to the Alignment of the class type, so that the
2224 -- back end does not have to deal with the X'Class'Alignment
2227 if Is_Entity_Name (Pref)
2228 and then Is_Class_Wide_Type (Entity (Pref))
2230 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
2233 -- For x'Alignment applied to an object of a class wide type,
2234 -- transform X'Alignment into a call to the predefined primitive
2235 -- operation _Alignment applied to X.
2237 elsif Is_Class_Wide_Type (Ptyp) then
2239 Make_Attribute_Reference (Loc,
2241 Attribute_Name => Name_Tag);
2243 New_Node := Build_Get_Alignment (Loc, New_Node);
2245 -- Case where the context is a specific integer type with which
2246 -- the original attribute was compatible. The function has a
2247 -- specific type as well, so to preserve the compatibility we
2248 -- must convert explicitly.
2250 if Typ /= Standard_Integer then
2251 New_Node := Convert_To (Typ, New_Node);
2254 Rewrite (N, New_Node);
2255 Analyze_And_Resolve (N, Typ);
2258 -- For all other cases, we just have to deal with the case of
2259 -- the fact that the result can be universal.
2262 Apply_Universal_Integer_Attribute_Checks (N);
2270 -- We compute this if a packed array reference was present, otherwise we
2271 -- leave the computation up to the back end.
2273 when Attribute_Bit =>
2274 if Involves_Packed_Array_Reference (Pref) then
2275 Expand_Packed_Bit_Reference (N);
2277 Apply_Universal_Integer_Attribute_Checks (N);
2284 -- We compute this if a component clause was present, otherwise we leave
2285 -- the computation up to the back end, since we don't know what layout
2288 -- Note that the attribute can apply to a naked record component
2289 -- in generated code (i.e. the prefix is an identifier that
2290 -- references the component or discriminant entity).
2292 when Attribute_Bit_Position => Bit_Position : declare
2296 if Nkind (Pref) = N_Identifier then
2297 CE := Entity (Pref);
2299 CE := Entity (Selector_Name (Pref));
2302 if Known_Static_Component_Bit_Offset (CE) then
2304 Make_Integer_Literal (Loc,
2305 Intval => Component_Bit_Offset (CE)));
2306 Analyze_And_Resolve (N, Typ);
2309 Apply_Universal_Integer_Attribute_Checks (N);
2317 -- A reference to P'Body_Version or P'Version is expanded to
2320 -- pragma Import (C, Vnn, "uuuuT");
2322 -- Get_Version_String (Vnn)
2324 -- where uuuu is the unit name (dots replaced by double underscore)
2325 -- and T is B for the cases of Body_Version, or Version applied to a
2326 -- subprogram acting as its own spec, and S for Version applied to a
2327 -- subprogram spec or package. This sequence of code references the
2328 -- unsigned constant created in the main program by the binder.
2330 -- A special exception occurs for Standard, where the string returned
2331 -- is a copy of the library string in gnatvsn.ads.
2333 when Attribute_Body_Version | Attribute_Version => Version : declare
2334 E : constant Entity_Id := Make_Temporary (Loc, 'V');
2339 -- If not library unit, get to containing library unit
2341 Pent := Entity (Pref);
2342 while Pent /= Standard_Standard
2343 and then Scope (Pent) /= Standard_Standard
2344 and then not Is_Child_Unit (Pent)
2346 Pent := Scope (Pent);
2349 -- Special case Standard and Standard.ASCII
2351 if Pent = Standard_Standard or else Pent = Standard_ASCII then
2353 Make_String_Literal (Loc,
2354 Strval => Verbose_Library_Version));
2359 -- Build required string constant
2361 Get_Name_String (Get_Unit_Name (Pent));
2364 for J in 1 .. Name_Len - 2 loop
2365 if Name_Buffer (J) = '.' then
2366 Store_String_Chars ("__");
2368 Store_String_Char (Get_Char_Code (Name_Buffer (J)));
2372 -- Case of subprogram acting as its own spec, always use body
2374 if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
2375 and then Nkind (Parent (Declaration_Node (Pent))) =
2377 and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
2379 Store_String_Chars ("B");
2381 -- Case of no body present, always use spec
2383 elsif not Unit_Requires_Body (Pent) then
2384 Store_String_Chars ("S");
2386 -- Otherwise use B for Body_Version, S for spec
2388 elsif Id = Attribute_Body_Version then
2389 Store_String_Chars ("B");
2391 Store_String_Chars ("S");
2395 Lib.Version_Referenced (S);
2397 -- Insert the object declaration
2399 Insert_Actions (N, New_List (
2400 Make_Object_Declaration (Loc,
2401 Defining_Identifier => E,
2402 Object_Definition =>
2403 New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
2405 -- Set entity as imported with correct external name
2407 Set_Is_Imported (E);
2408 Set_Interface_Name (E, Make_String_Literal (Loc, S));
2410 -- Set entity as internal to ensure proper Sprint output of its
2411 -- implicit importation.
2413 Set_Is_Internal (E);
2415 -- And now rewrite original reference
2418 Make_Function_Call (Loc,
2419 Name => New_Occurrence_Of (RTE (RE_Get_Version_String), Loc),
2420 Parameter_Associations => New_List (
2421 New_Occurrence_Of (E, Loc))));
2424 Analyze_And_Resolve (N, RTE (RE_Version_String));
2431 -- Transforms 'Ceiling into a call to the floating-point attribute
2432 -- function Ceiling in Fat_xxx (where xxx is the root type)
2434 when Attribute_Ceiling =>
2435 Expand_Fpt_Attribute_R (N);
2441 -- Transforms 'Callable attribute into a call to the Callable function
2443 when Attribute_Callable => Callable :
2445 -- We have an object of a task interface class-wide type as a prefix
2446 -- to Callable. Generate:
2447 -- callable (Task_Id (Pref._disp_get_task_id));
2449 if Ada_Version >= Ada_2005
2450 and then Ekind (Ptyp) = E_Class_Wide_Type
2451 and then Is_Interface (Ptyp)
2452 and then Is_Task_Interface (Ptyp)
2455 Make_Function_Call (Loc,
2457 New_Occurrence_Of (RTE (RE_Callable), Loc),
2458 Parameter_Associations => New_List (
2459 Make_Unchecked_Type_Conversion (Loc,
2461 New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
2463 Make_Selected_Component (Loc,
2465 New_Copy_Tree (Pref),
2467 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
2471 Build_Call_With_Task (Pref, RTE (RE_Callable)));
2474 Analyze_And_Resolve (N, Standard_Boolean);
2481 -- Transforms 'Caller attribute into a call to either the
2482 -- Task_Entry_Caller or the Protected_Entry_Caller function.
2484 when Attribute_Caller => Caller : declare
2485 Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
2486 Ent : constant Entity_Id := Entity (Pref);
2487 Conctype : constant Entity_Id := Scope (Ent);
2488 Nest_Depth : Integer := 0;
2495 if Is_Protected_Type (Conctype) then
2496 case Corresponding_Runtime_Package (Conctype) is
2497 when System_Tasking_Protected_Objects_Entries =>
2500 (RTE (RE_Protected_Entry_Caller), Loc);
2502 when System_Tasking_Protected_Objects_Single_Entry =>
2505 (RTE (RE_Protected_Single_Entry_Caller), Loc);
2508 raise Program_Error;
2512 Unchecked_Convert_To (Id_Kind,
2513 Make_Function_Call (Loc,
2515 Parameter_Associations => New_List (
2517 (Find_Protection_Object (Current_Scope), Loc)))));
2522 -- Determine the nesting depth of the E'Caller attribute, that
2523 -- is, how many accept statements are nested within the accept
2524 -- statement for E at the point of E'Caller. The runtime uses
2525 -- this depth to find the specified entry call.
2527 for J in reverse 0 .. Scope_Stack.Last loop
2528 S := Scope_Stack.Table (J).Entity;
2530 -- We should not reach the scope of the entry, as it should
2531 -- already have been checked in Sem_Attr that this attribute
2532 -- reference is within a matching accept statement.
2534 pragma Assert (S /= Conctype);
2539 elsif Is_Entry (S) then
2540 Nest_Depth := Nest_Depth + 1;
2545 Unchecked_Convert_To (Id_Kind,
2546 Make_Function_Call (Loc,
2548 New_Occurrence_Of (RTE (RE_Task_Entry_Caller), Loc),
2549 Parameter_Associations => New_List (
2550 Make_Integer_Literal (Loc,
2551 Intval => Int (Nest_Depth))))));
2554 Analyze_And_Resolve (N, Id_Kind);
2561 -- Transforms 'Compose into a call to the floating-point attribute
2562 -- function Compose in Fat_xxx (where xxx is the root type)
2564 -- Note: we strictly should have special code here to deal with the
2565 -- case of absurdly negative arguments (less than Integer'First)
2566 -- which will return a (signed) zero value, but it hardly seems
2567 -- worth the effort. Absurdly large positive arguments will raise
2568 -- constraint error which is fine.
2570 when Attribute_Compose =>
2571 Expand_Fpt_Attribute_RI (N);
2577 when Attribute_Constrained => Constrained : declare
2578 Formal_Ent : constant Entity_Id := Param_Entity (Pref);
2580 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
2581 -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
2582 -- view of an aliased object whose subtype is constrained.
2584 ---------------------------------
2585 -- Is_Constrained_Aliased_View --
2586 ---------------------------------
2588 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
2592 if Is_Entity_Name (Obj) then
2595 if Present (Renamed_Object (E)) then
2596 return Is_Constrained_Aliased_View (Renamed_Object (E));
2598 return Is_Aliased (E) and then Is_Constrained (Etype (E));
2602 return Is_Aliased_View (Obj)
2604 (Is_Constrained (Etype (Obj))
2606 (Nkind (Obj) = N_Explicit_Dereference
2608 not Object_Type_Has_Constrained_Partial_View
2609 (Typ => Base_Type (Etype (Obj)),
2610 Scop => Current_Scope)));
2612 end Is_Constrained_Aliased_View;
2614 -- Start of processing for Constrained
2617 -- Reference to a parameter where the value is passed as an extra
2618 -- actual, corresponding to the extra formal referenced by the
2619 -- Extra_Constrained field of the corresponding formal. If this
2620 -- is an entry in-parameter, it is replaced by a constant renaming
2621 -- for which Extra_Constrained is never created.
2623 if Present (Formal_Ent)
2624 and then Ekind (Formal_Ent) /= E_Constant
2625 and then Present (Extra_Constrained (Formal_Ent))
2629 (Extra_Constrained (Formal_Ent), Sloc (N)));
2631 -- For variables with a Extra_Constrained field, we use the
2632 -- corresponding entity.
2634 elsif Nkind (Pref) = N_Identifier
2635 and then Ekind (Entity (Pref)) = E_Variable
2636 and then Present (Extra_Constrained (Entity (Pref)))
2640 (Extra_Constrained (Entity (Pref)), Sloc (N)));
2642 -- For all other entity names, we can tell at compile time
2644 elsif Is_Entity_Name (Pref) then
2646 Ent : constant Entity_Id := Entity (Pref);
2650 -- (RM J.4) obsolescent cases
2652 if Is_Type (Ent) then
2656 if Is_Private_Type (Ent) then
2657 Res := not Has_Discriminants (Ent)
2658 or else Is_Constrained (Ent);
2660 -- It not a private type, must be a generic actual type
2661 -- that corresponded to a private type. We know that this
2662 -- correspondence holds, since otherwise the reference
2663 -- within the generic template would have been illegal.
2666 if Is_Composite_Type (Underlying_Type (Ent)) then
2667 Res := Is_Constrained (Ent);
2673 -- If the prefix is not a variable or is aliased, then
2674 -- definitely true; if it's a formal parameter without an
2675 -- associated extra formal, then treat it as constrained.
2677 -- Ada 2005 (AI-363): An aliased prefix must be known to be
2678 -- constrained in order to set the attribute to True.
2680 elsif not Is_Variable (Pref)
2681 or else Present (Formal_Ent)
2682 or else (Ada_Version < Ada_2005
2683 and then Is_Aliased_View (Pref))
2684 or else (Ada_Version >= Ada_2005
2685 and then Is_Constrained_Aliased_View (Pref))
2689 -- Variable case, look at type to see if it is constrained.
2690 -- Note that the one case where this is not accurate (the
2691 -- procedure formal case), has been handled above.
2693 -- We use the Underlying_Type here (and below) in case the
2694 -- type is private without discriminants, but the full type
2695 -- has discriminants. This case is illegal, but we generate it
2696 -- internally for passing to the Extra_Constrained parameter.
2699 -- In Ada 2012, test for case of a limited tagged type, in
2700 -- which case the attribute is always required to return
2701 -- True. The underlying type is tested, to make sure we also
2702 -- return True for cases where there is an unconstrained
2703 -- object with an untagged limited partial view which has
2704 -- defaulted discriminants (such objects always produce a
2705 -- False in earlier versions of Ada). (Ada 2012: AI05-0214)
2707 Res := Is_Constrained (Underlying_Type (Etype (Ent)))
2709 (Ada_Version >= Ada_2012
2710 and then Is_Tagged_Type (Underlying_Type (Ptyp))
2711 and then Is_Limited_Type (Ptyp));
2714 Rewrite (N, New_Occurrence_Of (Boolean_Literals (Res), Loc));
2717 -- Prefix is not an entity name. These are also cases where we can
2718 -- always tell at compile time by looking at the form and type of the
2719 -- prefix. If an explicit dereference of an object with constrained
2720 -- partial view, this is unconstrained (Ada 2005: AI95-0363). If the
2721 -- underlying type is a limited tagged type, then Constrained is
2722 -- required to always return True (Ada 2012: AI05-0214).
2728 not Is_Variable (Pref)
2730 (Nkind (Pref) = N_Explicit_Dereference
2732 not Object_Type_Has_Constrained_Partial_View
2733 (Typ => Base_Type (Ptyp),
2734 Scop => Current_Scope))
2735 or else Is_Constrained (Underlying_Type (Ptyp))
2736 or else (Ada_Version >= Ada_2012
2737 and then Is_Tagged_Type (Underlying_Type (Ptyp))
2738 and then Is_Limited_Type (Ptyp))),
2742 Analyze_And_Resolve (N, Standard_Boolean);
2749 -- Transforms 'Copy_Sign into a call to the floating-point attribute
2750 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
2752 when Attribute_Copy_Sign =>
2753 Expand_Fpt_Attribute_RR (N);
2759 -- Transforms 'Count attribute into a call to the Count function
2761 when Attribute_Count => Count : declare
2763 Conctyp : Entity_Id;
2765 Entry_Id : Entity_Id;
2770 -- If the prefix is a member of an entry family, retrieve both
2771 -- entry name and index. For a simple entry there is no index.
2773 if Nkind (Pref) = N_Indexed_Component then
2774 Entnam := Prefix (Pref);
2775 Index := First (Expressions (Pref));
2781 Entry_Id := Entity (Entnam);
2783 -- Find the concurrent type in which this attribute is referenced
2784 -- (there had better be one).
2786 Conctyp := Current_Scope;
2787 while not Is_Concurrent_Type (Conctyp) loop
2788 Conctyp := Scope (Conctyp);
2793 if Is_Protected_Type (Conctyp) then
2794 case Corresponding_Runtime_Package (Conctyp) is
2795 when System_Tasking_Protected_Objects_Entries =>
2796 Name := New_Occurrence_Of (RTE (RE_Protected_Count), Loc);
2799 Make_Function_Call (Loc,
2801 Parameter_Associations => New_List (
2803 (Find_Protection_Object (Current_Scope), Loc),
2804 Entry_Index_Expression
2805 (Loc, Entry_Id, Index, Scope (Entry_Id))));
2807 when System_Tasking_Protected_Objects_Single_Entry =>
2809 New_Occurrence_Of (RTE (RE_Protected_Count_Entry), Loc);
2812 Make_Function_Call (Loc,
2814 Parameter_Associations => New_List (
2816 (Find_Protection_Object (Current_Scope), Loc)));
2819 raise Program_Error;
2826 Make_Function_Call (Loc,
2827 Name => New_Occurrence_Of (RTE (RE_Task_Count), Loc),
2828 Parameter_Associations => New_List (
2829 Entry_Index_Expression (Loc,
2830 Entry_Id, Index, Scope (Entry_Id))));
2833 -- The call returns type Natural but the context is universal integer
2834 -- so any integer type is allowed. The attribute was already resolved
2835 -- so its Etype is the required result type. If the base type of the
2836 -- context type is other than Standard.Integer we put in a conversion
2837 -- to the required type. This can be a normal typed conversion since
2838 -- both input and output types of the conversion are integer types
2840 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
2841 Rewrite (N, Convert_To (Typ, Call));
2846 Analyze_And_Resolve (N, Typ);
2849 ---------------------
2850 -- Descriptor_Size --
2851 ---------------------
2853 when Attribute_Descriptor_Size =>
2855 -- Attribute Descriptor_Size is handled by the back end when applied
2856 -- to an unconstrained array type.
2858 if Is_Array_Type (Ptyp)
2859 and then not Is_Constrained (Ptyp)
2861 Apply_Universal_Integer_Attribute_Checks (N);
2863 -- For any other type, the descriptor size is 0 because there is no
2864 -- actual descriptor, but the result is not formally static.
2867 Rewrite (N, Make_Integer_Literal (Loc, 0));
2869 Set_Is_Static_Expression (N, False);
2876 -- This processing is shared by Elab_Spec
2878 -- What we do is to insert the following declarations
2881 -- pragma Import (C, enn, "name___elabb/s");
2883 -- and then the Elab_Body/Spec attribute is replaced by a reference
2884 -- to this defining identifier.
2886 when Attribute_Elab_Body |
2887 Attribute_Elab_Spec =>
2889 -- Leave attribute unexpanded in CodePeer mode: the gnat2scil
2890 -- back-end knows how to handle these attributes directly.
2892 if CodePeer_Mode then
2897 Ent : constant Entity_Id := Make_Temporary (Loc, 'E');
2901 procedure Make_Elab_String (Nod : Node_Id);
2902 -- Given Nod, an identifier, or a selected component, put the
2903 -- image into the current string literal, with double underline
2904 -- between components.
2906 ----------------------
2907 -- Make_Elab_String --
2908 ----------------------
2910 procedure Make_Elab_String (Nod : Node_Id) is
2912 if Nkind (Nod) = N_Selected_Component then
2913 Make_Elab_String (Prefix (Nod));
2914 Store_String_Char ('_');
2915 Store_String_Char ('_');
2916 Get_Name_String (Chars (Selector_Name (Nod)));
2919 pragma Assert (Nkind (Nod) = N_Identifier);
2920 Get_Name_String (Chars (Nod));
2923 Store_String_Chars (Name_Buffer (1 .. Name_Len));
2924 end Make_Elab_String;
2926 -- Start of processing for Elab_Body/Elab_Spec
2929 -- First we need to prepare the string literal for the name of
2930 -- the elaboration routine to be referenced.
2933 Make_Elab_String (Pref);
2934 Store_String_Chars ("___elab");
2935 Lang := Make_Identifier (Loc, Name_C);
2937 if Id = Attribute_Elab_Body then
2938 Store_String_Char ('b');
2940 Store_String_Char ('s');
2945 Insert_Actions (N, New_List (
2946 Make_Subprogram_Declaration (Loc,
2948 Make_Procedure_Specification (Loc,
2949 Defining_Unit_Name => Ent)),
2952 Chars => Name_Import,
2953 Pragma_Argument_Associations => New_List (
2954 Make_Pragma_Argument_Association (Loc, Expression => Lang),
2956 Make_Pragma_Argument_Association (Loc,
2957 Expression => Make_Identifier (Loc, Chars (Ent))),
2959 Make_Pragma_Argument_Association (Loc,
2960 Expression => Make_String_Literal (Loc, Str))))));
2962 Set_Entity (N, Ent);
2963 Rewrite (N, New_Occurrence_Of (Ent, Loc));
2966 --------------------
2967 -- Elab_Subp_Body --
2968 --------------------
2970 -- Always ignored. In CodePeer mode, gnat2scil knows how to handle
2971 -- this attribute directly, and if we are not in CodePeer mode it is
2972 -- entirely ignored ???
2974 when Attribute_Elab_Subp_Body =>
2981 -- Elaborated is always True for preelaborated units, predefined units,
2982 -- pure units and units which have Elaborate_Body pragmas. These units
2983 -- have no elaboration entity.
2985 -- Note: The Elaborated attribute is never passed to the back end
2987 when Attribute_Elaborated => Elaborated : declare
2988 Ent : constant Entity_Id := Entity (Pref);
2991 if Present (Elaboration_Entity (Ent)) then
2995 New_Occurrence_Of (Elaboration_Entity (Ent), Loc),
2997 Make_Integer_Literal (Loc, Uint_0)));
2998 Analyze_And_Resolve (N, Typ);
3000 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3008 when Attribute_Enum_Rep => Enum_Rep :
3010 -- X'Enum_Rep (Y) expands to
3014 -- This is simply a direct conversion from the enumeration type to
3015 -- the target integer type, which is treated by the back end as a
3016 -- normal integer conversion, treating the enumeration type as an
3017 -- integer, which is exactly what we want. We set Conversion_OK to
3018 -- make sure that the analyzer does not complain about what otherwise
3019 -- might be an illegal conversion.
3021 if Is_Non_Empty_List (Exprs) then
3023 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
3025 -- X'Enum_Rep where X is an enumeration literal is replaced by
3026 -- the literal value.
3028 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
3030 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
3032 -- If this is a renaming of a literal, recover the representation
3033 -- of the original. If it renames an expression there is nothing
3036 elsif Ekind (Entity (Pref)) = E_Constant
3037 and then Present (Renamed_Object (Entity (Pref)))
3038 and then Is_Entity_Name (Renamed_Object (Entity (Pref)))
3039 and then Ekind (Entity (Renamed_Object (Entity (Pref)))) =
3040 E_Enumeration_Literal
3043 Make_Integer_Literal (Loc,
3044 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
3046 -- X'Enum_Rep where X is an object does a direct unchecked conversion
3047 -- of the object value, as described for the type case above.
3051 OK_Convert_To (Typ, Relocate_Node (Pref)));
3055 Analyze_And_Resolve (N, Typ);
3062 when Attribute_Enum_Val => Enum_Val : declare
3064 Btyp : constant Entity_Id := Base_Type (Ptyp);
3067 -- X'Enum_Val (Y) expands to
3069 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
3072 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
3075 Make_Raise_Constraint_Error (Loc,
3079 Make_Function_Call (Loc,
3081 New_Occurrence_Of (TSS (Btyp, TSS_Rep_To_Pos), Loc),
3082 Parameter_Associations => New_List (
3083 Relocate_Node (Duplicate_Subexpr (Expr)),
3084 New_Occurrence_Of (Standard_False, Loc))),
3086 Right_Opnd => Make_Integer_Literal (Loc, -1)),
3087 Reason => CE_Range_Check_Failed));
3090 Analyze_And_Resolve (N, Ptyp);
3097 -- Transforms 'Exponent into a call to the floating-point attribute
3098 -- function Exponent in Fat_xxx (where xxx is the root type)
3100 when Attribute_Exponent =>
3101 Expand_Fpt_Attribute_R (N);
3107 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
3109 when Attribute_External_Tag => External_Tag :
3112 Make_Function_Call (Loc,
3113 Name => New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3114 Parameter_Associations => New_List (
3115 Make_Attribute_Reference (Loc,
3116 Attribute_Name => Name_Tag,
3117 Prefix => Prefix (N)))));
3119 Analyze_And_Resolve (N, Standard_String);
3126 when Attribute_First =>
3128 -- If the prefix type is a constrained packed array type which
3129 -- already has a Packed_Array_Impl_Type representation defined, then
3130 -- replace this attribute with a direct reference to 'First of the
3131 -- appropriate index subtype (since otherwise the back end will try
3132 -- to give us the value of 'First for this implementation type).
3134 if Is_Constrained_Packed_Array (Ptyp) then
3136 Make_Attribute_Reference (Loc,
3137 Attribute_Name => Name_First,
3139 New_Occurrence_Of (Get_Index_Subtype (N), Loc)));
3140 Analyze_And_Resolve (N, Typ);
3142 -- For access type, apply access check as needed
3144 elsif Is_Access_Type (Ptyp) then
3145 Apply_Access_Check (N);
3147 -- For scalar type, if low bound is a reference to an entity, just
3148 -- replace with a direct reference. Note that we can only have a
3149 -- reference to a constant entity at this stage, anything else would
3150 -- have already been rewritten.
3152 elsif Is_Scalar_Type (Ptyp) then
3154 Lo : constant Node_Id := Type_Low_Bound (Ptyp);
3156 if Is_Entity_Name (Lo) then
3157 Rewrite (N, New_Occurrence_Of (Entity (Lo), Loc));
3166 -- Compute this if component clause was present, otherwise we leave the
3167 -- computation to be completed in the back-end, since we don't know what
3168 -- layout will be chosen.
3170 when Attribute_First_Bit => First_Bit_Attr : declare
3171 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3174 -- In Ada 2005 (or later) if we have the non-default bit order, then
3175 -- we return the original value as given in the component clause
3176 -- (RM 2005 13.5.2(3/2)).
3178 if Present (Component_Clause (CE))
3179 and then Ada_Version >= Ada_2005
3180 and then Reverse_Bit_Order (Scope (CE))
3183 Make_Integer_Literal (Loc,
3184 Intval => Expr_Value (First_Bit (Component_Clause (CE)))));
3185 Analyze_And_Resolve (N, Typ);
3187 -- Otherwise (Ada 83/95 or Ada 2005 or later with default bit order),
3188 -- rewrite with normalized value if we know it statically.
3190 elsif Known_Static_Component_Bit_Offset (CE) then
3192 Make_Integer_Literal (Loc,
3193 Component_Bit_Offset (CE) mod System_Storage_Unit));
3194 Analyze_And_Resolve (N, Typ);
3196 -- Otherwise left to back end, just do universal integer checks
3199 Apply_Universal_Integer_Attribute_Checks (N);
3209 -- fixtype'Fixed_Value (integer-value)
3213 -- fixtype(integer-value)
3215 -- We do all the required analysis of the conversion here, because we do
3216 -- not want this to go through the fixed-point conversion circuits. Note
3217 -- that the back end always treats fixed-point as equivalent to the
3218 -- corresponding integer type anyway.
3220 when Attribute_Fixed_Value => Fixed_Value :
3223 Make_Type_Conversion (Loc,
3224 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
3225 Expression => Relocate_Node (First (Exprs))));
3226 Set_Etype (N, Entity (Pref));
3229 -- Note: it might appear that a properly analyzed unchecked conversion
3230 -- would be just fine here, but that's not the case, since the full
3231 -- range checks performed by the following call are critical.
3233 Apply_Type_Conversion_Checks (N);
3240 -- Transforms 'Floor into a call to the floating-point attribute
3241 -- function Floor in Fat_xxx (where xxx is the root type)
3243 when Attribute_Floor =>
3244 Expand_Fpt_Attribute_R (N);
3250 -- For the fixed-point type Typ:
3256 -- Result_Type (System.Fore (Universal_Real (Type'First)),
3257 -- Universal_Real (Type'Last))
3259 -- Note that we know that the type is a non-static subtype, or Fore
3260 -- would have itself been computed dynamically in Eval_Attribute.
3262 when Attribute_Fore => Fore : begin
3265 Make_Function_Call (Loc,
3266 Name => New_Occurrence_Of (RTE (RE_Fore), Loc),
3268 Parameter_Associations => New_List (
3269 Convert_To (Universal_Real,
3270 Make_Attribute_Reference (Loc,
3271 Prefix => New_Occurrence_Of (Ptyp, Loc),
3272 Attribute_Name => Name_First)),
3274 Convert_To (Universal_Real,
3275 Make_Attribute_Reference (Loc,
3276 Prefix => New_Occurrence_Of (Ptyp, Loc),
3277 Attribute_Name => Name_Last))))));
3279 Analyze_And_Resolve (N, Typ);
3286 -- Transforms 'Fraction into a call to the floating-point attribute
3287 -- function Fraction in Fat_xxx (where xxx is the root type)
3289 when Attribute_Fraction =>
3290 Expand_Fpt_Attribute_R (N);
3296 when Attribute_From_Any => From_Any : declare
3297 P_Type : constant Entity_Id := Etype (Pref);
3298 Decls : constant List_Id := New_List;
3301 Build_From_Any_Call (P_Type,
3302 Relocate_Node (First (Exprs)),
3304 Insert_Actions (N, Decls);
3305 Analyze_And_Resolve (N, P_Type);
3308 ----------------------
3309 -- Has_Same_Storage --
3310 ----------------------
3312 when Attribute_Has_Same_Storage => Has_Same_Storage : declare
3313 Loc : constant Source_Ptr := Sloc (N);
3315 X : constant Node_Id := Prefix (N);
3316 Y : constant Node_Id := First (Expressions (N));
3319 X_Addr, Y_Addr : Node_Id;
3320 -- Rhe expressions for their addresses
3322 X_Size, Y_Size : Node_Id;
3323 -- Rhe expressions for their sizes
3326 -- The attribute is expanded as:
3328 -- (X'address = Y'address)
3329 -- and then (X'Size = Y'Size)
3331 -- If both arguments have the same Etype the second conjunct can be
3335 Make_Attribute_Reference (Loc,
3336 Attribute_Name => Name_Address,
3337 Prefix => New_Copy_Tree (X));
3340 Make_Attribute_Reference (Loc,
3341 Attribute_Name => Name_Address,
3342 Prefix => New_Copy_Tree (Y));
3345 Make_Attribute_Reference (Loc,
3346 Attribute_Name => Name_Size,
3347 Prefix => New_Copy_Tree (X));
3350 Make_Attribute_Reference (Loc,
3351 Attribute_Name => Name_Size,
3352 Prefix => New_Copy_Tree (Y));
3354 if Etype (X) = Etype (Y) then
3357 Left_Opnd => X_Addr,
3358 Right_Opnd => Y_Addr)));
3364 Left_Opnd => X_Addr,
3365 Right_Opnd => Y_Addr),
3368 Left_Opnd => X_Size,
3369 Right_Opnd => Y_Size)));
3372 Analyze_And_Resolve (N, Standard_Boolean);
3373 end Has_Same_Storage;
3379 -- For an exception returns a reference to the exception data:
3380 -- Exception_Id!(Prefix'Reference)
3382 -- For a task it returns a reference to the _task_id component of
3383 -- corresponding record:
3385 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
3387 -- in Ada.Task_Identification
3389 when Attribute_Identity => Identity : declare
3390 Id_Kind : Entity_Id;
3393 if Ptyp = Standard_Exception_Type then
3394 Id_Kind := RTE (RE_Exception_Id);
3396 if Present (Renamed_Object (Entity (Pref))) then
3397 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
3401 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
3403 Id_Kind := RTE (RO_AT_Task_Id);
3405 -- If the prefix is a task interface, the Task_Id is obtained
3406 -- dynamically through a dispatching call, as for other task
3407 -- attributes applied to interfaces.
3409 if Ada_Version >= Ada_2005
3410 and then Ekind (Ptyp) = E_Class_Wide_Type
3411 and then Is_Interface (Ptyp)
3412 and then Is_Task_Interface (Ptyp)
3415 Unchecked_Convert_To (Id_Kind,
3416 Make_Selected_Component (Loc,
3418 New_Copy_Tree (Pref),
3420 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
3424 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
3428 Analyze_And_Resolve (N, Id_Kind);
3435 -- Image attribute is handled in separate unit Exp_Imgv
3437 when Attribute_Image =>
3438 Exp_Imgv.Expand_Image_Attribute (N);
3444 -- X'Img is expanded to typ'Image (X), where typ is the type of X
3446 when Attribute_Img => Img :
3449 Make_Attribute_Reference (Loc,
3450 Prefix => New_Occurrence_Of (Ptyp, Loc),
3451 Attribute_Name => Name_Image,
3452 Expressions => New_List (Relocate_Node (Pref))));
3454 Analyze_And_Resolve (N, Standard_String);
3461 when Attribute_Input => Input : declare
3462 P_Type : constant Entity_Id := Entity (Pref);
3463 B_Type : constant Entity_Id := Base_Type (P_Type);
3464 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3465 Strm : constant Node_Id := First (Exprs);
3473 Cntrl : Node_Id := Empty;
3474 -- Value for controlling argument in call. Always Empty except in
3475 -- the dispatching (class-wide type) case, where it is a reference
3476 -- to the dummy object initialized to the right internal tag.
3478 procedure Freeze_Stream_Subprogram (F : Entity_Id);
3479 -- The expansion of the attribute reference may generate a call to
3480 -- a user-defined stream subprogram that is frozen by the call. This
3481 -- can lead to access-before-elaboration problem if the reference
3482 -- appears in an object declaration and the subprogram body has not
3483 -- been seen. The freezing of the subprogram requires special code
3484 -- because it appears in an expanded context where expressions do
3485 -- not freeze their constituents.
3487 ------------------------------
3488 -- Freeze_Stream_Subprogram --
3489 ------------------------------
3491 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
3492 Decl : constant Node_Id := Unit_Declaration_Node (F);
3496 -- If this is user-defined subprogram, the corresponding
3497 -- stream function appears as a renaming-as-body, and the
3498 -- user subprogram must be retrieved by tree traversal.
3501 and then Nkind (Decl) = N_Subprogram_Declaration
3502 and then Present (Corresponding_Body (Decl))
3504 Bod := Corresponding_Body (Decl);
3506 if Nkind (Unit_Declaration_Node (Bod)) =
3507 N_Subprogram_Renaming_Declaration
3509 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
3512 end Freeze_Stream_Subprogram;
3514 -- Start of processing for Input
3517 -- If no underlying type, we have an error that will be diagnosed
3518 -- elsewhere, so here we just completely ignore the expansion.
3524 -- Stream operations can appear in user code even if the restriction
3525 -- No_Streams is active (for example, when instantiating a predefined
3526 -- container). In that case rewrite the attribute as a Raise to
3527 -- prevent any run-time use.
3529 if Restriction_Active (No_Streams) then
3531 Make_Raise_Program_Error (Sloc (N),
3532 Reason => PE_Stream_Operation_Not_Allowed));
3533 Set_Etype (N, B_Type);
3537 -- If there is a TSS for Input, just call it
3539 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
3541 if Present (Fname) then
3545 -- If there is a Stream_Convert pragma, use it, we rewrite
3547 -- sourcetyp'Input (stream)
3551 -- sourcetyp (streamread (strmtyp'Input (stream)));
3553 -- where streamread is the given Read function that converts an
3554 -- argument of type strmtyp to type sourcetyp or a type from which
3555 -- it is derived (extra conversion required for the derived case).
3557 Prag := Get_Stream_Convert_Pragma (P_Type);
3559 if Present (Prag) then
3560 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3561 Rfunc := Entity (Expression (Arg2));
3565 Make_Function_Call (Loc,
3566 Name => New_Occurrence_Of (Rfunc, Loc),
3567 Parameter_Associations => New_List (
3568 Make_Attribute_Reference (Loc,
3571 (Etype (First_Formal (Rfunc)), Loc),
3572 Attribute_Name => Name_Input,
3573 Expressions => Exprs)))));
3575 Analyze_And_Resolve (N, B_Type);
3580 elsif Is_Elementary_Type (U_Type) then
3582 -- A special case arises if we have a defined _Read routine,
3583 -- since in this case we are required to call this routine.
3585 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
3586 Build_Record_Or_Elementary_Input_Function
3587 (Loc, U_Type, Decl, Fname);
3588 Insert_Action (N, Decl);
3590 -- For normal cases, we call the I_xxx routine directly
3593 Rewrite (N, Build_Elementary_Input_Call (N));
3594 Analyze_And_Resolve (N, P_Type);
3600 elsif Is_Array_Type (U_Type) then
3601 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
3602 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3604 -- Dispatching case with class-wide type
3606 elsif Is_Class_Wide_Type (P_Type) then
3608 -- No need to do anything else compiling under restriction
3609 -- No_Dispatching_Calls. During the semantic analysis we
3610 -- already notified such violation.
3612 if Restriction_Active (No_Dispatching_Calls) then
3617 Rtyp : constant Entity_Id := Root_Type (P_Type);
3621 -- Read the internal tag (RM 13.13.2(34)) and use it to
3622 -- initialize a dummy tag value:
3624 -- Descendant_Tag (String'Input (Strm), P_Type);
3626 -- This value is used only to provide a controlling
3627 -- argument for the eventual _Input call. Descendant_Tag is
3628 -- called rather than Internal_Tag to ensure that we have a
3629 -- tag for a type that is descended from the prefix type and
3630 -- declared at the same accessibility level (the exception
3631 -- Tag_Error will be raised otherwise). The level check is
3632 -- required for Ada 2005 because tagged types can be
3633 -- extended in nested scopes (AI-344).
3635 -- Note: we used to generate an explicit declaration of a
3636 -- constant Ada.Tags.Tag object, and use an occurrence of
3637 -- this constant in Cntrl, but this caused a secondary stack
3641 Make_Function_Call (Loc,
3643 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
3644 Parameter_Associations => New_List (
3645 Make_Attribute_Reference (Loc,
3647 New_Occurrence_Of (Standard_String, Loc),
3648 Attribute_Name => Name_Input,
3649 Expressions => New_List (
3650 Relocate_Node (Duplicate_Subexpr (Strm)))),
3651 Make_Attribute_Reference (Loc,
3652 Prefix => New_Occurrence_Of (P_Type, Loc),
3653 Attribute_Name => Name_Tag)));
3654 Set_Etype (Expr, RTE (RE_Tag));
3656 -- Now we need to get the entity for the call, and construct
3657 -- a function call node, where we preset a reference to Dnn
3658 -- as the controlling argument (doing an unchecked convert
3659 -- to the class-wide tagged type to make it look like a real
3662 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
3663 Cntrl := Unchecked_Convert_To (P_Type, Expr);
3664 Set_Etype (Cntrl, P_Type);
3665 Set_Parent (Cntrl, N);
3668 -- For tagged types, use the primitive Input function
3670 elsif Is_Tagged_Type (U_Type) then
3671 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
3673 -- All other record type cases, including protected records. The
3674 -- latter only arise for expander generated code for handling
3675 -- shared passive partition access.
3679 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3681 -- Ada 2005 (AI-216): Program_Error is raised executing default
3682 -- implementation of the Input attribute of an unchecked union
3683 -- type if the type lacks default discriminant values.
3685 if Is_Unchecked_Union (Base_Type (U_Type))
3686 and then No (Discriminant_Constraint (U_Type))
3689 Make_Raise_Program_Error (Loc,
3690 Reason => PE_Unchecked_Union_Restriction));
3695 -- Build the type's Input function, passing the subtype rather
3696 -- than its base type, because checks are needed in the case of
3697 -- constrained discriminants (see Ada 2012 AI05-0192).
3699 Build_Record_Or_Elementary_Input_Function
3700 (Loc, U_Type, Decl, Fname);
3701 Insert_Action (N, Decl);
3703 if Nkind (Parent (N)) = N_Object_Declaration
3704 and then Is_Record_Type (U_Type)
3706 -- The stream function may contain calls to user-defined
3707 -- Read procedures for individual components.
3714 Comp := First_Component (U_Type);
3715 while Present (Comp) loop
3717 Find_Stream_Subprogram
3718 (Etype (Comp), TSS_Stream_Read);
3720 if Present (Func) then
3721 Freeze_Stream_Subprogram (Func);
3724 Next_Component (Comp);
3731 -- If we fall through, Fname is the function to be called. The result
3732 -- is obtained by calling the appropriate function, then converting
3733 -- the result. The conversion does a subtype check.
3736 Make_Function_Call (Loc,
3737 Name => New_Occurrence_Of (Fname, Loc),
3738 Parameter_Associations => New_List (
3739 Relocate_Node (Strm)));
3741 Set_Controlling_Argument (Call, Cntrl);
3742 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
3743 Analyze_And_Resolve (N, P_Type);
3745 if Nkind (Parent (N)) = N_Object_Declaration then
3746 Freeze_Stream_Subprogram (Fname);
3756 -- inttype'Fixed_Value (fixed-value)
3760 -- inttype(integer-value))
3762 -- we do all the required analysis of the conversion here, because we do
3763 -- not want this to go through the fixed-point conversion circuits. Note
3764 -- that the back end always treats fixed-point as equivalent to the
3765 -- corresponding integer type anyway.
3767 when Attribute_Integer_Value => Integer_Value :
3770 Make_Type_Conversion (Loc,
3771 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
3772 Expression => Relocate_Node (First (Exprs))));
3773 Set_Etype (N, Entity (Pref));
3776 -- Note: it might appear that a properly analyzed unchecked conversion
3777 -- would be just fine here, but that's not the case, since the full
3778 -- range checks performed by the following call are critical.
3780 Apply_Type_Conversion_Checks (N);
3787 when Attribute_Invalid_Value =>
3788 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
3794 when Attribute_Last =>
3796 -- If the prefix type is a constrained packed array type which
3797 -- already has a Packed_Array_Impl_Type representation defined, then
3798 -- replace this attribute with a direct reference to 'Last of the
3799 -- appropriate index subtype (since otherwise the back end will try
3800 -- to give us the value of 'Last for this implementation type).
3802 if Is_Constrained_Packed_Array (Ptyp) then
3804 Make_Attribute_Reference (Loc,
3805 Attribute_Name => Name_Last,
3806 Prefix => New_Occurrence_Of (Get_Index_Subtype (N), Loc)));
3807 Analyze_And_Resolve (N, Typ);
3809 -- For access type, apply access check as needed
3811 elsif Is_Access_Type (Ptyp) then
3812 Apply_Access_Check (N);
3814 -- For scalar type, if low bound is a reference to an entity, just
3815 -- replace with a direct reference. Note that we can only have a
3816 -- reference to a constant entity at this stage, anything else would
3817 -- have already been rewritten.
3819 elsif Is_Scalar_Type (Ptyp) then
3821 Hi : constant Node_Id := Type_High_Bound (Ptyp);
3823 if Is_Entity_Name (Hi) then
3824 Rewrite (N, New_Occurrence_Of (Entity (Hi), Loc));
3833 -- We compute this if a component clause was present, otherwise we leave
3834 -- the computation up to the back end, since we don't know what layout
3837 when Attribute_Last_Bit => Last_Bit_Attr : declare
3838 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3841 -- In Ada 2005 (or later) if we have the non-default bit order, then
3842 -- we return the original value as given in the component clause
3843 -- (RM 2005 13.5.2(3/2)).
3845 if Present (Component_Clause (CE))
3846 and then Ada_Version >= Ada_2005
3847 and then Reverse_Bit_Order (Scope (CE))
3850 Make_Integer_Literal (Loc,
3851 Intval => Expr_Value (Last_Bit (Component_Clause (CE)))));
3852 Analyze_And_Resolve (N, Typ);
3854 -- Otherwise (Ada 83/95 or Ada 2005 or later with default bit order),
3855 -- rewrite with normalized value if we know it statically.
3857 elsif Known_Static_Component_Bit_Offset (CE)
3858 and then Known_Static_Esize (CE)
3861 Make_Integer_Literal (Loc,
3862 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
3864 Analyze_And_Resolve (N, Typ);
3866 -- Otherwise leave to back end, just apply universal integer checks
3869 Apply_Universal_Integer_Attribute_Checks (N);
3877 -- Transforms 'Leading_Part into a call to the floating-point attribute
3878 -- function Leading_Part in Fat_xxx (where xxx is the root type)
3880 -- Note: strictly, we should generate special case code to deal with
3881 -- absurdly large positive arguments (greater than Integer'Last), which
3882 -- result in returning the first argument unchanged, but it hardly seems
3883 -- worth the effort. We raise constraint error for absurdly negative
3884 -- arguments which is fine.
3886 when Attribute_Leading_Part =>
3887 Expand_Fpt_Attribute_RI (N);
3893 when Attribute_Length => Length : declare
3898 -- Processing for packed array types
3900 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
3901 Ityp := Get_Index_Subtype (N);
3903 -- If the index type, Ityp, is an enumeration type with holes,
3904 -- then we calculate X'Length explicitly using
3907 -- (0, Ityp'Pos (X'Last (N)) -
3908 -- Ityp'Pos (X'First (N)) + 1);
3910 -- Since the bounds in the template are the representation values
3911 -- and the back end would get the wrong value.
3913 if Is_Enumeration_Type (Ityp)
3914 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
3919 Xnum := Expr_Value (First (Expressions (N)));
3923 Make_Attribute_Reference (Loc,
3924 Prefix => New_Occurrence_Of (Typ, Loc),
3925 Attribute_Name => Name_Max,
3926 Expressions => New_List
3927 (Make_Integer_Literal (Loc, 0),
3931 Make_Op_Subtract (Loc,
3933 Make_Attribute_Reference (Loc,
3934 Prefix => New_Occurrence_Of (Ityp, Loc),
3935 Attribute_Name => Name_Pos,
3937 Expressions => New_List (
3938 Make_Attribute_Reference (Loc,
3939 Prefix => Duplicate_Subexpr (Pref),
3940 Attribute_Name => Name_Last,
3941 Expressions => New_List (
3942 Make_Integer_Literal (Loc, Xnum))))),
3945 Make_Attribute_Reference (Loc,
3946 Prefix => New_Occurrence_Of (Ityp, Loc),
3947 Attribute_Name => Name_Pos,
3949 Expressions => New_List (
3950 Make_Attribute_Reference (Loc,
3952 Duplicate_Subexpr_No_Checks (Pref),
3953 Attribute_Name => Name_First,
3954 Expressions => New_List (
3955 Make_Integer_Literal (Loc, Xnum)))))),
3957 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
3959 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
3962 -- If the prefix type is a constrained packed array type which
3963 -- already has a Packed_Array_Impl_Type representation defined,
3964 -- then replace this attribute with a reference to 'Range_Length
3965 -- of the appropriate index subtype (since otherwise the
3966 -- back end will try to give us the value of 'Length for
3967 -- this implementation type).s
3969 elsif Is_Constrained (Ptyp) then
3971 Make_Attribute_Reference (Loc,
3972 Attribute_Name => Name_Range_Length,
3973 Prefix => New_Occurrence_Of (Ityp, Loc)));
3974 Analyze_And_Resolve (N, Typ);
3979 elsif Is_Access_Type (Ptyp) then
3980 Apply_Access_Check (N);
3982 -- If the designated type is a packed array type, then we convert
3983 -- the reference to:
3986 -- xtyp'Pos (Pref'Last (Expr)) -
3987 -- xtyp'Pos (Pref'First (Expr)));
3989 -- This is a bit complex, but it is the easiest thing to do that
3990 -- works in all cases including enum types with holes xtyp here
3991 -- is the appropriate index type.
3994 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
3998 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
3999 Xtyp := Get_Index_Subtype (N);
4002 Make_Attribute_Reference (Loc,
4003 Prefix => New_Occurrence_Of (Typ, Loc),
4004 Attribute_Name => Name_Max,
4005 Expressions => New_List (
4006 Make_Integer_Literal (Loc, 0),
4009 Make_Integer_Literal (Loc, 1),
4010 Make_Op_Subtract (Loc,
4012 Make_Attribute_Reference (Loc,
4013 Prefix => New_Occurrence_Of (Xtyp, Loc),
4014 Attribute_Name => Name_Pos,
4015 Expressions => New_List (
4016 Make_Attribute_Reference (Loc,
4017 Prefix => Duplicate_Subexpr (Pref),
4018 Attribute_Name => Name_Last,
4020 New_Copy_List (Exprs)))),
4023 Make_Attribute_Reference (Loc,
4024 Prefix => New_Occurrence_Of (Xtyp, Loc),
4025 Attribute_Name => Name_Pos,
4026 Expressions => New_List (
4027 Make_Attribute_Reference (Loc,
4029 Duplicate_Subexpr_No_Checks (Pref),
4030 Attribute_Name => Name_First,
4032 New_Copy_List (Exprs)))))))));
4034 Analyze_And_Resolve (N, Typ);
4038 -- Otherwise leave it to the back end
4041 Apply_Universal_Integer_Attribute_Checks (N);
4045 -- Attribute Loop_Entry is replaced with a reference to a constant value
4046 -- which captures the prefix at the entry point of the related loop. The
4047 -- loop itself may be transformed into a conditional block.
4049 when Attribute_Loop_Entry =>
4050 Expand_Loop_Entry_Attribute (N);
4056 -- Transforms 'Machine into a call to the floating-point attribute
4057 -- function Machine in Fat_xxx (where xxx is the root type).
4058 -- Expansion is avoided for cases the back end can handle directly.
4060 when Attribute_Machine =>
4061 if not Is_Inline_Floating_Point_Attribute (N) then
4062 Expand_Fpt_Attribute_R (N);
4065 ----------------------
4066 -- Machine_Rounding --
4067 ----------------------
4069 -- Transforms 'Machine_Rounding into a call to the floating-point
4070 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
4071 -- type). Expansion is avoided for cases the back end can handle
4074 when Attribute_Machine_Rounding =>
4075 if not Is_Inline_Floating_Point_Attribute (N) then
4076 Expand_Fpt_Attribute_R (N);
4083 -- Machine_Size is equivalent to Object_Size, so transform it into
4084 -- Object_Size and that way the back end never sees Machine_Size.
4086 when Attribute_Machine_Size =>
4088 Make_Attribute_Reference (Loc,
4089 Prefix => Prefix (N),
4090 Attribute_Name => Name_Object_Size));
4092 Analyze_And_Resolve (N, Typ);
4098 -- The only case that can get this far is the dynamic case of the old
4099 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
4106 -- ityp (System.Mantissa.Mantissa_Value
4107 -- (Integer'Integer_Value (typ'First),
4108 -- Integer'Integer_Value (typ'Last)));
4110 when Attribute_Mantissa => Mantissa : begin
4113 Make_Function_Call (Loc,
4114 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
4116 Parameter_Associations => New_List (
4118 Make_Attribute_Reference (Loc,
4119 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
4120 Attribute_Name => Name_Integer_Value,
4121 Expressions => New_List (
4123 Make_Attribute_Reference (Loc,
4124 Prefix => New_Occurrence_Of (Ptyp, Loc),
4125 Attribute_Name => Name_First))),
4127 Make_Attribute_Reference (Loc,
4128 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
4129 Attribute_Name => Name_Integer_Value,
4130 Expressions => New_List (
4132 Make_Attribute_Reference (Loc,
4133 Prefix => New_Occurrence_Of (Ptyp, Loc),
4134 Attribute_Name => Name_Last)))))));
4136 Analyze_And_Resolve (N, Typ);
4143 when Attribute_Max =>
4144 Expand_Min_Max_Attribute (N);
4146 ----------------------------------
4147 -- Max_Size_In_Storage_Elements --
4148 ----------------------------------
4150 when Attribute_Max_Size_In_Storage_Elements => declare
4151 Typ : constant Entity_Id := Etype (N);
4154 Conversion_Added : Boolean := False;
4155 -- A flag which tracks whether the original attribute has been
4156 -- wrapped inside a type conversion.
4159 -- If the prefix is X'Class, we transform it into a direct reference
4160 -- to the class-wide type, because the back end must not see a 'Class
4161 -- reference. See also 'Size.
4163 if Is_Entity_Name (Pref)
4164 and then Is_Class_Wide_Type (Entity (Pref))
4166 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
4170 Apply_Universal_Integer_Attribute_Checks (N);
4172 -- The universal integer check may sometimes add a type conversion,
4173 -- retrieve the original attribute reference from the expression.
4177 if Nkind (Attr) = N_Type_Conversion then
4178 Attr := Expression (Attr);
4179 Conversion_Added := True;
4182 pragma Assert (Nkind (Attr) = N_Attribute_Reference);
4184 -- Heap-allocated controlled objects contain two extra pointers which
4185 -- are not part of the actual type. Transform the attribute reference
4186 -- into a runtime expression to add the size of the hidden header.
4188 if Needs_Finalization (Ptyp)
4189 and then not Header_Size_Added (Attr)
4191 Set_Header_Size_Added (Attr);
4194 -- P'Max_Size_In_Storage_Elements +
4195 -- Universal_Integer
4196 -- (Header_Size_With_Padding (Ptyp'Alignment))
4200 Left_Opnd => Relocate_Node (Attr),
4202 Convert_To (Universal_Integer,
4203 Make_Function_Call (Loc,
4206 (RTE (RE_Header_Size_With_Padding), Loc),
4208 Parameter_Associations => New_List (
4209 Make_Attribute_Reference (Loc,
4211 New_Occurrence_Of (Ptyp, Loc),
4212 Attribute_Name => Name_Alignment))))));
4214 -- Add a conversion to the target type
4216 if not Conversion_Added then
4218 Make_Type_Conversion (Loc,
4219 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
4220 Expression => Relocate_Node (Attr)));
4228 --------------------
4229 -- Mechanism_Code --
4230 --------------------
4232 when Attribute_Mechanism_Code =>
4234 -- We must replace the prefix i the renamed case
4236 if Is_Entity_Name (Pref)
4237 and then Present (Alias (Entity (Pref)))
4239 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
4246 when Attribute_Min =>
4247 Expand_Min_Max_Attribute (N);
4253 when Attribute_Mod => Mod_Case : declare
4254 Arg : constant Node_Id := Relocate_Node (First (Exprs));
4255 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
4256 Modv : constant Uint := Modulus (Btyp);
4260 -- This is not so simple. The issue is what type to use for the
4261 -- computation of the modular value.
4263 -- The easy case is when the modulus value is within the bounds
4264 -- of the signed integer type of the argument. In this case we can
4265 -- just do the computation in that signed integer type, and then
4266 -- do an ordinary conversion to the target type.
4268 if Modv <= Expr_Value (Hi) then
4273 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
4275 -- Here we know that the modulus is larger than type'Last of the
4276 -- integer type. There are two cases to consider:
4278 -- a) The integer value is non-negative. In this case, it is
4279 -- returned as the result (since it is less than the modulus).
4281 -- b) The integer value is negative. In this case, we know that the
4282 -- result is modulus + value, where the value might be as small as
4283 -- -modulus. The trouble is what type do we use to do the subtract.
4284 -- No type will do, since modulus can be as big as 2**64, and no
4285 -- integer type accommodates this value. Let's do bit of algebra
4288 -- = modulus - (-value)
4289 -- = (modulus - 1) - (-value - 1)
4291 -- Now modulus - 1 is certainly in range of the modular type.
4292 -- -value is in the range 1 .. modulus, so -value -1 is in the
4293 -- range 0 .. modulus-1 which is in range of the modular type.
4294 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
4295 -- which we can compute using the integer base type.
4297 -- Once this is done we analyze the if expression without range
4298 -- checks, because we know everything is in range, and we want
4299 -- to prevent spurious warnings on either branch.
4303 Make_If_Expression (Loc,
4304 Expressions => New_List (
4306 Left_Opnd => Duplicate_Subexpr (Arg),
4307 Right_Opnd => Make_Integer_Literal (Loc, 0)),
4310 Duplicate_Subexpr_No_Checks (Arg)),
4312 Make_Op_Subtract (Loc,
4314 Make_Integer_Literal (Loc,
4315 Intval => Modv - 1),
4321 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
4323 Make_Integer_Literal (Loc,
4324 Intval => 1))))))));
4328 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
4335 -- Transforms 'Model into a call to the floating-point attribute
4336 -- function Model in Fat_xxx (where xxx is the root type).
4337 -- Expansion is avoided for cases the back end can handle directly.
4339 when Attribute_Model =>
4340 if not Is_Inline_Floating_Point_Attribute (N) then
4341 Expand_Fpt_Attribute_R (N);
4348 -- The processing for Object_Size shares the processing for Size
4354 when Attribute_Old => Old : declare
4355 Typ : constant Entity_Id := Etype (N);
4356 CW_Temp : Entity_Id;
4362 -- Climb the parent chain looking for subprogram _Postconditions
4365 while Present (Subp) loop
4366 exit when Nkind (Subp) = N_Subprogram_Body
4367 and then Chars (Defining_Entity (Subp)) = Name_uPostconditions;
4369 -- If assertions are disabled, no need to create the declaration
4370 -- that preserves the value. The postcondition pragma in which
4371 -- 'Old appears will be checked or disabled according to the
4372 -- current policy in effect.
4374 if Nkind (Subp) = N_Pragma and then not Is_Checked (Subp) then
4378 Subp := Parent (Subp);
4381 -- 'Old can only appear in a postcondition, the generated body of
4382 -- _Postconditions must be in the tree.
4384 pragma Assert (Present (Subp));
4386 Temp := Make_Temporary (Loc, 'T', Pref);
4388 -- Set the entity kind now in order to mark the temporary as a
4389 -- handler of attribute 'Old's prefix.
4391 Set_Ekind (Temp, E_Constant);
4392 Set_Stores_Attribute_Old_Prefix (Temp);
4394 -- Push the scope of the related subprogram where _Postcondition
4395 -- resides as this ensures that the object will be analyzed in the
4398 Push_Scope (Scope (Defining_Entity (Subp)));
4400 -- Preserve the tag of the prefix by offering a specific view of the
4401 -- class-wide version of the prefix.
4403 if Is_Tagged_Type (Typ) then
4406 -- CW_Temp : constant Typ'Class := Typ'Class (Pref);
4408 CW_Temp := Make_Temporary (Loc, 'T');
4409 CW_Typ := Class_Wide_Type (Typ);
4411 Insert_Before_And_Analyze (Subp,
4412 Make_Object_Declaration (Loc,
4413 Defining_Identifier => CW_Temp,
4414 Constant_Present => True,
4415 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
4417 Convert_To (CW_Typ, Relocate_Node (Pref))));
4420 -- Temp : Typ renames Typ (CW_Temp);
4422 Insert_Before_And_Analyze (Subp,
4423 Make_Object_Renaming_Declaration (Loc,
4424 Defining_Identifier => Temp,
4425 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
4427 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc))));
4433 -- Temp : constant Typ := Pref;
4435 Insert_Before_And_Analyze (Subp,
4436 Make_Object_Declaration (Loc,
4437 Defining_Identifier => Temp,
4438 Constant_Present => True,
4439 Object_Definition => New_Occurrence_Of (Typ, Loc),
4440 Expression => Relocate_Node (Pref)));
4445 -- Ensure that the prefix of attribute 'Old is valid. The check must
4446 -- be inserted after the expansion of the attribute has taken place
4447 -- to reflect the new placement of the prefix.
4449 if Validity_Checks_On and then Validity_Check_Operands then
4450 Ensure_Valid (Pref);
4453 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4456 ----------------------
4457 -- Overlaps_Storage --
4458 ----------------------
4460 when Attribute_Overlaps_Storage => Overlaps_Storage : declare
4461 Loc : constant Source_Ptr := Sloc (N);
4463 X : constant Node_Id := Prefix (N);
4464 Y : constant Node_Id := First (Expressions (N));
4467 X_Addr, Y_Addr : Node_Id;
4468 -- the expressions for their integer addresses
4470 X_Size, Y_Size : Node_Id;
4471 -- the expressions for their sizes
4476 -- Attribute expands into:
4478 -- if X'Address < Y'address then
4479 -- (X'address + X'Size - 1) >= Y'address
4481 -- (Y'address + Y'size - 1) >= X'Address
4484 -- with the proper address operations. We convert addresses to
4485 -- integer addresses to use predefined arithmetic. The size is
4486 -- expressed in storage units.
4489 Unchecked_Convert_To (RTE (RE_Integer_Address),
4490 Make_Attribute_Reference (Loc,
4491 Attribute_Name => Name_Address,
4492 Prefix => New_Copy_Tree (X)));
4495 Unchecked_Convert_To (RTE (RE_Integer_Address),
4496 Make_Attribute_Reference (Loc,
4497 Attribute_Name => Name_Address,
4498 Prefix => New_Copy_Tree (Y)));
4501 Make_Op_Divide (Loc,
4503 Make_Attribute_Reference (Loc,
4504 Attribute_Name => Name_Size,
4505 Prefix => New_Copy_Tree (X)),
4507 Make_Integer_Literal (Loc, System_Storage_Unit));
4510 Make_Op_Divide (Loc,
4512 Make_Attribute_Reference (Loc,
4513 Attribute_Name => Name_Size,
4514 Prefix => New_Copy_Tree (Y)),
4516 Make_Integer_Literal (Loc, System_Storage_Unit));
4520 Left_Opnd => X_Addr,
4521 Right_Opnd => Y_Addr);
4524 Make_If_Expression (Loc,
4531 Left_Opnd => X_Addr,
4533 Make_Op_Subtract (Loc,
4534 Left_Opnd => X_Size,
4535 Right_Opnd => Make_Integer_Literal (Loc, 1))),
4536 Right_Opnd => Y_Addr),
4540 Left_Opnd => Y_Addr,
4542 Make_Op_Subtract (Loc,
4543 Left_Opnd => Y_Size,
4544 Right_Opnd => Make_Integer_Literal (Loc, 1))),
4545 Right_Opnd => X_Addr))));
4547 Analyze_And_Resolve (N, Standard_Boolean);
4548 end Overlaps_Storage;
4554 when Attribute_Output => Output : declare
4555 P_Type : constant Entity_Id := Entity (Pref);
4556 U_Type : constant Entity_Id := Underlying_Type (P_Type);
4564 -- If no underlying type, we have an error that will be diagnosed
4565 -- elsewhere, so here we just completely ignore the expansion.
4571 -- Stream operations can appear in user code even if the restriction
4572 -- No_Streams is active (for example, when instantiating a predefined
4573 -- container). In that case rewrite the attribute as a Raise to
4574 -- prevent any run-time use.
4576 if Restriction_Active (No_Streams) then
4578 Make_Raise_Program_Error (Sloc (N),
4579 Reason => PE_Stream_Operation_Not_Allowed));
4580 Set_Etype (N, Standard_Void_Type);
4584 -- If TSS for Output is present, just call it
4586 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
4588 if Present (Pname) then
4592 -- If there is a Stream_Convert pragma, use it, we rewrite
4594 -- sourcetyp'Output (stream, Item)
4598 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
4600 -- where strmwrite is the given Write function that converts an
4601 -- argument of type sourcetyp or a type acctyp, from which it is
4602 -- derived to type strmtyp. The conversion to acttyp is required
4603 -- for the derived case.
4605 Prag := Get_Stream_Convert_Pragma (P_Type);
4607 if Present (Prag) then
4609 Next (Next (First (Pragma_Argument_Associations (Prag))));
4610 Wfunc := Entity (Expression (Arg3));
4613 Make_Attribute_Reference (Loc,
4614 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
4615 Attribute_Name => Name_Output,
4616 Expressions => New_List (
4617 Relocate_Node (First (Exprs)),
4618 Make_Function_Call (Loc,
4619 Name => New_Occurrence_Of (Wfunc, Loc),
4620 Parameter_Associations => New_List (
4621 OK_Convert_To (Etype (First_Formal (Wfunc)),
4622 Relocate_Node (Next (First (Exprs)))))))));
4627 -- For elementary types, we call the W_xxx routine directly. Note
4628 -- that the effect of Write and Output is identical for the case
4629 -- of an elementary type (there are no discriminants or bounds).
4631 elsif Is_Elementary_Type (U_Type) then
4633 -- A special case arises if we have a defined _Write routine,
4634 -- since in this case we are required to call this routine.
4636 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
4637 Build_Record_Or_Elementary_Output_Procedure
4638 (Loc, U_Type, Decl, Pname);
4639 Insert_Action (N, Decl);
4641 -- For normal cases, we call the W_xxx routine directly
4644 Rewrite (N, Build_Elementary_Write_Call (N));
4651 elsif Is_Array_Type (U_Type) then
4652 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
4653 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
4655 -- Class-wide case, first output external tag, then dispatch
4656 -- to the appropriate primitive Output function (RM 13.13.2(31)).
4658 elsif Is_Class_Wide_Type (P_Type) then
4660 -- No need to do anything else compiling under restriction
4661 -- No_Dispatching_Calls. During the semantic analysis we
4662 -- already notified such violation.
4664 if Restriction_Active (No_Dispatching_Calls) then
4669 Strm : constant Node_Id := First (Exprs);
4670 Item : constant Node_Id := Next (Strm);
4673 -- Ada 2005 (AI-344): Check that the accessibility level
4674 -- of the type of the output object is not deeper than
4675 -- that of the attribute's prefix type.
4677 -- if Get_Access_Level (Item'Tag)
4678 -- /= Get_Access_Level (P_Type'Tag)
4683 -- String'Output (Strm, External_Tag (Item'Tag));
4685 -- We cannot figure out a practical way to implement this
4686 -- accessibility check on virtual machines, so we omit it.
4688 if Ada_Version >= Ada_2005
4689 and then Tagged_Type_Expansion
4692 Make_Implicit_If_Statement (N,
4696 Build_Get_Access_Level (Loc,
4697 Make_Attribute_Reference (Loc,
4700 Duplicate_Subexpr (Item,
4702 Attribute_Name => Name_Tag)),
4705 Make_Integer_Literal (Loc,
4706 Type_Access_Level (P_Type))),
4709 New_List (Make_Raise_Statement (Loc,
4711 RTE (RE_Tag_Error), Loc)))));
4715 Make_Attribute_Reference (Loc,
4716 Prefix => New_Occurrence_Of (Standard_String, Loc),
4717 Attribute_Name => Name_Output,
4718 Expressions => New_List (
4719 Relocate_Node (Duplicate_Subexpr (Strm)),
4720 Make_Function_Call (Loc,
4722 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
4723 Parameter_Associations => New_List (
4724 Make_Attribute_Reference (Loc,
4727 (Duplicate_Subexpr (Item, Name_Req => True)),
4728 Attribute_Name => Name_Tag))))));
4731 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
4733 -- Tagged type case, use the primitive Output function
4735 elsif Is_Tagged_Type (U_Type) then
4736 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
4738 -- All other record type cases, including protected records.
4739 -- The latter only arise for expander generated code for
4740 -- handling shared passive partition access.
4744 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
4746 -- Ada 2005 (AI-216): Program_Error is raised when executing
4747 -- the default implementation of the Output attribute of an
4748 -- unchecked union type if the type lacks default discriminant
4751 if Is_Unchecked_Union (Base_Type (U_Type))
4752 and then No (Discriminant_Constraint (U_Type))
4755 Make_Raise_Program_Error (Loc,
4756 Reason => PE_Unchecked_Union_Restriction));
4761 Build_Record_Or_Elementary_Output_Procedure
4762 (Loc, Base_Type (U_Type), Decl, Pname);
4763 Insert_Action (N, Decl);
4767 -- If we fall through, Pname is the name of the procedure to call
4769 Rewrite_Stream_Proc_Call (Pname);
4776 -- For enumeration types with a standard representation, Pos is
4777 -- handled by the back end.
4779 -- For enumeration types, with a non-standard representation we generate
4780 -- a call to the _Rep_To_Pos function created when the type was frozen.
4781 -- The call has the form
4783 -- _rep_to_pos (expr, flag)
4785 -- The parameter flag is True if range checks are enabled, causing
4786 -- Program_Error to be raised if the expression has an invalid
4787 -- representation, and False if range checks are suppressed.
4789 -- For integer types, Pos is equivalent to a simple integer
4790 -- conversion and we rewrite it as such
4792 when Attribute_Pos => Pos :
4794 Etyp : Entity_Id := Base_Type (Entity (Pref));
4797 -- Deal with zero/non-zero boolean values
4799 if Is_Boolean_Type (Etyp) then
4800 Adjust_Condition (First (Exprs));
4801 Etyp := Standard_Boolean;
4802 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
4805 -- Case of enumeration type
4807 if Is_Enumeration_Type (Etyp) then
4809 -- Non-standard enumeration type (generate call)
4811 if Present (Enum_Pos_To_Rep (Etyp)) then
4812 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
4815 Make_Function_Call (Loc,
4817 New_Occurrence_Of (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4818 Parameter_Associations => Exprs)));
4820 Analyze_And_Resolve (N, Typ);
4822 -- Standard enumeration type (do universal integer check)
4825 Apply_Universal_Integer_Attribute_Checks (N);
4828 -- Deal with integer types (replace by conversion)
4830 elsif Is_Integer_Type (Etyp) then
4831 Rewrite (N, Convert_To (Typ, First (Exprs)));
4832 Analyze_And_Resolve (N, Typ);
4841 -- We compute this if a component clause was present, otherwise we leave
4842 -- the computation up to the back end, since we don't know what layout
4845 when Attribute_Position => Position_Attr :
4847 CE : constant Entity_Id := Entity (Selector_Name (Pref));
4850 if Present (Component_Clause (CE)) then
4852 -- In Ada 2005 (or later) if we have the non-default bit order,
4853 -- then we return the original value as given in the component
4854 -- clause (RM 2005 13.5.2(2/2)).
4856 if Ada_Version >= Ada_2005
4857 and then Reverse_Bit_Order (Scope (CE))
4860 Make_Integer_Literal (Loc,
4861 Intval => Expr_Value (Position (Component_Clause (CE)))));
4863 -- Otherwise (Ada 83 or 95, or default bit order specified in
4864 -- later Ada version), return the normalized value.
4868 Make_Integer_Literal (Loc,
4869 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
4872 Analyze_And_Resolve (N, Typ);
4874 -- If back end is doing things, just apply universal integer checks
4877 Apply_Universal_Integer_Attribute_Checks (N);
4885 -- 1. Deal with enumeration types with holes.
4886 -- 2. For floating-point, generate call to attribute function.
4887 -- 3. For other cases, deal with constraint checking.
4889 when Attribute_Pred => Pred :
4891 Etyp : constant Entity_Id := Base_Type (Ptyp);
4895 -- For enumeration types with non-standard representations, we
4896 -- expand typ'Pred (x) into
4898 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
4900 -- If the representation is contiguous, we compute instead
4901 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
4902 -- The conversion function Enum_Pos_To_Rep is defined on the
4903 -- base type, not the subtype, so we have to use the base type
4904 -- explicitly for this and other enumeration attributes.
4906 if Is_Enumeration_Type (Ptyp)
4907 and then Present (Enum_Pos_To_Rep (Etyp))
4909 if Has_Contiguous_Rep (Etyp) then
4911 Unchecked_Convert_To (Ptyp,
4914 Make_Integer_Literal (Loc,
4915 Enumeration_Rep (First_Literal (Ptyp))),
4917 Make_Function_Call (Loc,
4920 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4922 Parameter_Associations =>
4924 Unchecked_Convert_To (Ptyp,
4925 Make_Op_Subtract (Loc,
4927 Unchecked_Convert_To (Standard_Integer,
4928 Relocate_Node (First (Exprs))),
4930 Make_Integer_Literal (Loc, 1))),
4931 Rep_To_Pos_Flag (Ptyp, Loc))))));
4934 -- Add Boolean parameter True, to request program errror if
4935 -- we have a bad representation on our hands. If checks are
4936 -- suppressed, then add False instead
4938 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4940 Make_Indexed_Component (Loc,
4943 (Enum_Pos_To_Rep (Etyp), Loc),
4944 Expressions => New_List (
4945 Make_Op_Subtract (Loc,
4947 Make_Function_Call (Loc,
4950 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4951 Parameter_Associations => Exprs),
4952 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4955 Analyze_And_Resolve (N, Typ);
4957 -- For floating-point, we transform 'Pred into a call to the Pred
4958 -- floating-point attribute function in Fat_xxx (xxx is root type).
4959 -- Note that this function takes care of the overflow case.
4961 elsif Is_Floating_Point_Type (Ptyp) then
4962 Expand_Fpt_Attribute_R (N);
4963 Analyze_And_Resolve (N, Typ);
4965 -- For modular types, nothing to do (no overflow, since wraps)
4967 elsif Is_Modular_Integer_Type (Ptyp) then
4970 -- For other types, if argument is marked as needing a range check or
4971 -- overflow checking is enabled, we must generate a check.
4973 elsif not Overflow_Checks_Suppressed (Ptyp)
4974 or else Do_Range_Check (First (Exprs))
4976 Set_Do_Range_Check (First (Exprs), False);
4977 Expand_Pred_Succ_Attribute (N);
4985 -- Ada 2005 (AI-327): Dynamic ceiling priorities
4987 -- We rewrite X'Priority as the following run-time call:
4989 -- Get_Ceiling (X._Object)
4991 -- Note that although X'Priority is notionally an object, it is quite
4992 -- deliberately not defined as an aliased object in the RM. This means
4993 -- that it works fine to rewrite it as a call, without having to worry
4994 -- about complications that would other arise from X'Priority'Access,
4995 -- which is illegal, because of the lack of aliasing.
4997 when Attribute_Priority =>
5000 Conctyp : Entity_Id;
5001 Object_Parm : Node_Id;
5003 RT_Subprg_Name : Node_Id;
5006 -- Look for the enclosing concurrent type
5008 Conctyp := Current_Scope;
5009 while not Is_Concurrent_Type (Conctyp) loop
5010 Conctyp := Scope (Conctyp);
5013 pragma Assert (Is_Protected_Type (Conctyp));
5015 -- Generate the actual of the call
5017 Subprg := Current_Scope;
5018 while not Present (Protected_Body_Subprogram (Subprg)) loop
5019 Subprg := Scope (Subprg);
5022 -- Use of 'Priority inside protected entries and barriers (in
5023 -- both cases the type of the first formal of their expanded
5024 -- subprogram is Address)
5026 if Etype (First_Entity (Protected_Body_Subprogram (Subprg))) =
5030 New_Itype : Entity_Id;
5033 -- In the expansion of protected entries the type of the
5034 -- first formal of the Protected_Body_Subprogram is an
5035 -- Address. In order to reference the _object component
5038 -- type T is access p__ptTV;
5041 New_Itype := Create_Itype (E_Access_Type, N);
5042 Set_Etype (New_Itype, New_Itype);
5043 Set_Directly_Designated_Type (New_Itype,
5044 Corresponding_Record_Type (Conctyp));
5045 Freeze_Itype (New_Itype, N);
5048 -- T!(O)._object'unchecked_access
5051 Make_Attribute_Reference (Loc,
5053 Make_Selected_Component (Loc,
5055 Unchecked_Convert_To (New_Itype,
5058 (Protected_Body_Subprogram (Subprg)),
5061 Make_Identifier (Loc, Name_uObject)),
5062 Attribute_Name => Name_Unchecked_Access);
5065 -- Use of 'Priority inside a protected subprogram
5069 Make_Attribute_Reference (Loc,
5071 Make_Selected_Component (Loc,
5072 Prefix => New_Occurrence_Of
5074 (Protected_Body_Subprogram (Subprg)),
5076 Selector_Name => Make_Identifier (Loc, Name_uObject)),
5077 Attribute_Name => Name_Unchecked_Access);
5080 -- Select the appropriate run-time subprogram
5082 if Number_Entries (Conctyp) = 0 then
5084 New_Occurrence_Of (RTE (RE_Get_Ceiling), Loc);
5087 New_Occurrence_Of (RTE (RO_PE_Get_Ceiling), Loc);
5091 Make_Function_Call (Loc,
5092 Name => RT_Subprg_Name,
5093 Parameter_Associations => New_List (Object_Parm));
5097 -- Avoid the generation of extra checks on the pointer to the
5098 -- protected object.
5100 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
5107 when Attribute_Range_Length => Range_Length : begin
5109 -- The only special processing required is for the case where
5110 -- Range_Length is applied to an enumeration type with holes.
5111 -- In this case we transform
5117 -- X'Pos (X'Last) - X'Pos (X'First) + 1
5119 -- So that the result reflects the proper Pos values instead
5120 -- of the underlying representations.
5122 if Is_Enumeration_Type (Ptyp)
5123 and then Has_Non_Standard_Rep (Ptyp)
5128 Make_Op_Subtract (Loc,
5130 Make_Attribute_Reference (Loc,
5131 Attribute_Name => Name_Pos,
5132 Prefix => New_Occurrence_Of (Ptyp, Loc),
5133 Expressions => New_List (
5134 Make_Attribute_Reference (Loc,
5135 Attribute_Name => Name_Last,
5136 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
5139 Make_Attribute_Reference (Loc,
5140 Attribute_Name => Name_Pos,
5141 Prefix => New_Occurrence_Of (Ptyp, Loc),
5142 Expressions => New_List (
5143 Make_Attribute_Reference (Loc,
5144 Attribute_Name => Name_First,
5145 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
5147 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5149 Analyze_And_Resolve (N, Typ);
5151 -- For all other cases, the attribute is handled by the back end, but
5152 -- we need to deal with the case of the range check on a universal
5156 Apply_Universal_Integer_Attribute_Checks (N);
5164 when Attribute_Read => Read : declare
5165 P_Type : constant Entity_Id := Entity (Pref);
5166 B_Type : constant Entity_Id := Base_Type (P_Type);
5167 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5177 -- If no underlying type, we have an error that will be diagnosed
5178 -- elsewhere, so here we just completely ignore the expansion.
5184 -- Stream operations can appear in user code even if the restriction
5185 -- No_Streams is active (for example, when instantiating a predefined
5186 -- container). In that case rewrite the attribute as a Raise to
5187 -- prevent any run-time use.
5189 if Restriction_Active (No_Streams) then
5191 Make_Raise_Program_Error (Sloc (N),
5192 Reason => PE_Stream_Operation_Not_Allowed));
5193 Set_Etype (N, B_Type);
5197 -- The simple case, if there is a TSS for Read, just call it
5199 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
5201 if Present (Pname) then
5205 -- If there is a Stream_Convert pragma, use it, we rewrite
5207 -- sourcetyp'Read (stream, Item)
5211 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
5213 -- where strmread is the given Read function that converts an
5214 -- argument of type strmtyp to type sourcetyp or a type from which
5215 -- it is derived. The conversion to sourcetyp is required in the
5218 -- A special case arises if Item is a type conversion in which
5219 -- case, we have to expand to:
5221 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
5223 -- where Itemx is the expression of the type conversion (i.e.
5224 -- the actual object), and typex is the type of Itemx.
5226 Prag := Get_Stream_Convert_Pragma (P_Type);
5228 if Present (Prag) then
5229 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
5230 Rfunc := Entity (Expression (Arg2));
5231 Lhs := Relocate_Node (Next (First (Exprs)));
5233 OK_Convert_To (B_Type,
5234 Make_Function_Call (Loc,
5235 Name => New_Occurrence_Of (Rfunc, Loc),
5236 Parameter_Associations => New_List (
5237 Make_Attribute_Reference (Loc,
5240 (Etype (First_Formal (Rfunc)), Loc),
5241 Attribute_Name => Name_Input,
5242 Expressions => New_List (
5243 Relocate_Node (First (Exprs)))))));
5245 if Nkind (Lhs) = N_Type_Conversion then
5246 Lhs := Expression (Lhs);
5247 Rhs := Convert_To (Etype (Lhs), Rhs);
5251 Make_Assignment_Statement (Loc,
5253 Expression => Rhs));
5254 Set_Assignment_OK (Lhs);
5258 -- For elementary types, we call the I_xxx routine using the first
5259 -- parameter and then assign the result into the second parameter.
5260 -- We set Assignment_OK to deal with the conversion case.
5262 elsif Is_Elementary_Type (U_Type) then
5268 Lhs := Relocate_Node (Next (First (Exprs)));
5269 Rhs := Build_Elementary_Input_Call (N);
5271 if Nkind (Lhs) = N_Type_Conversion then
5272 Lhs := Expression (Lhs);
5273 Rhs := Convert_To (Etype (Lhs), Rhs);
5276 Set_Assignment_OK (Lhs);
5279 Make_Assignment_Statement (Loc,
5281 Expression => Rhs));
5289 elsif Is_Array_Type (U_Type) then
5290 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
5291 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5293 -- Tagged type case, use the primitive Read function. Note that
5294 -- this will dispatch in the class-wide case which is what we want
5296 elsif Is_Tagged_Type (U_Type) then
5297 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
5299 -- All other record type cases, including protected records. The
5300 -- latter only arise for expander generated code for handling
5301 -- shared passive partition access.
5305 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5307 -- Ada 2005 (AI-216): Program_Error is raised when executing
5308 -- the default implementation of the Read attribute of an
5309 -- Unchecked_Union type.
5311 if Is_Unchecked_Union (Base_Type (U_Type)) then
5313 Make_Raise_Program_Error (Loc,
5314 Reason => PE_Unchecked_Union_Restriction));
5317 if Has_Discriminants (U_Type)
5319 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5321 Build_Mutable_Record_Read_Procedure
5322 (Loc, Full_Base (U_Type), Decl, Pname);
5324 Build_Record_Read_Procedure
5325 (Loc, Full_Base (U_Type), Decl, Pname);
5328 -- Suppress checks, uninitialized or otherwise invalid
5329 -- data does not cause constraint errors to be raised for
5330 -- a complete record read.
5332 Insert_Action (N, Decl, All_Checks);
5336 Rewrite_Stream_Proc_Call (Pname);
5343 -- Ref is identical to To_Address, see To_Address for processing
5349 -- Transforms 'Remainder into a call to the floating-point attribute
5350 -- function Remainder in Fat_xxx (where xxx is the root type)
5352 when Attribute_Remainder =>
5353 Expand_Fpt_Attribute_RR (N);
5359 -- Transform 'Result into reference to _Result formal. At the point
5360 -- where a legal 'Result attribute is expanded, we know that we are in
5361 -- the context of a _Postcondition function with a _Result parameter.
5363 when Attribute_Result =>
5364 Rewrite (N, Make_Identifier (Loc, Chars => Name_uResult));
5365 Analyze_And_Resolve (N, Typ);
5371 -- The handling of the Round attribute is quite delicate. The processing
5372 -- in Sem_Attr introduced a conversion to universal real, reflecting the
5373 -- semantics of Round, but we do not want anything to do with universal
5374 -- real at runtime, since this corresponds to using floating-point
5377 -- What we have now is that the Etype of the Round attribute correctly
5378 -- indicates the final result type. The operand of the Round is the
5379 -- conversion to universal real, described above, and the operand of
5380 -- this conversion is the actual operand of Round, which may be the
5381 -- special case of a fixed point multiplication or division (Etype =
5384 -- The exapander will expand first the operand of the conversion, then
5385 -- the conversion, and finally the round attribute itself, since we
5386 -- always work inside out. But we cannot simply process naively in this
5387 -- order. In the semantic world where universal fixed and real really
5388 -- exist and have infinite precision, there is no problem, but in the
5389 -- implementation world, where universal real is a floating-point type,
5390 -- we would get the wrong result.
5392 -- So the approach is as follows. First, when expanding a multiply or
5393 -- divide whose type is universal fixed, we do nothing at all, instead
5394 -- deferring the operation till later.
5396 -- The actual processing is done in Expand_N_Type_Conversion which
5397 -- handles the special case of Round by looking at its parent to see if
5398 -- it is a Round attribute, and if it is, handling the conversion (or
5399 -- its fixed multiply/divide child) in an appropriate manner.
5401 -- This means that by the time we get to expanding the Round attribute
5402 -- itself, the Round is nothing more than a type conversion (and will
5403 -- often be a null type conversion), so we just replace it with the
5404 -- appropriate conversion operation.
5406 when Attribute_Round =>
5408 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
5409 Analyze_And_Resolve (N);
5415 -- Transforms 'Rounding into a call to the floating-point attribute
5416 -- function Rounding in Fat_xxx (where xxx is the root type)
5417 -- Expansion is avoided for cases the back end can handle directly.
5419 when Attribute_Rounding =>
5420 if not Is_Inline_Floating_Point_Attribute (N) then
5421 Expand_Fpt_Attribute_R (N);
5428 -- Transforms 'Scaling into a call to the floating-point attribute
5429 -- function Scaling in Fat_xxx (where xxx is the root type)
5431 when Attribute_Scaling =>
5432 Expand_Fpt_Attribute_RI (N);
5434 -------------------------
5435 -- Simple_Storage_Pool --
5436 -------------------------
5438 when Attribute_Simple_Storage_Pool =>
5440 Make_Type_Conversion (Loc,
5441 Subtype_Mark => New_Occurrence_Of (Etype (N), Loc),
5442 Expression => New_Occurrence_Of (Entity (N), Loc)));
5443 Analyze_And_Resolve (N, Typ);
5449 when Attribute_Size |
5450 Attribute_Object_Size |
5451 Attribute_Value_Size |
5452 Attribute_VADS_Size => Size :
5459 -- Processing for VADS_Size case. Note that this processing removes
5460 -- all traces of VADS_Size from the tree, and completes all required
5461 -- processing for VADS_Size by translating the attribute reference
5462 -- to an appropriate Size or Object_Size reference.
5464 if Id = Attribute_VADS_Size
5465 or else (Use_VADS_Size and then Id = Attribute_Size)
5467 -- If the size is specified, then we simply use the specified
5468 -- size. This applies to both types and objects. The size of an
5469 -- object can be specified in the following ways:
5471 -- An explicit size object is given for an object
5472 -- A component size is specified for an indexed component
5473 -- A component clause is specified for a selected component
5474 -- The object is a component of a packed composite object
5476 -- If the size is specified, then VADS_Size of an object
5478 if (Is_Entity_Name (Pref)
5479 and then Present (Size_Clause (Entity (Pref))))
5481 (Nkind (Pref) = N_Component_Clause
5482 and then (Present (Component_Clause
5483 (Entity (Selector_Name (Pref))))
5484 or else Is_Packed (Etype (Prefix (Pref)))))
5486 (Nkind (Pref) = N_Indexed_Component
5487 and then (Component_Size (Etype (Prefix (Pref))) /= 0
5488 or else Is_Packed (Etype (Prefix (Pref)))))
5490 Set_Attribute_Name (N, Name_Size);
5492 -- Otherwise if we have an object rather than a type, then the
5493 -- VADS_Size attribute applies to the type of the object, rather
5494 -- than the object itself. This is one of the respects in which
5495 -- VADS_Size differs from Size.
5498 if (not Is_Entity_Name (Pref)
5499 or else not Is_Type (Entity (Pref)))
5500 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
5502 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
5505 -- For a scalar type for which no size was explicitly given,
5506 -- VADS_Size means Object_Size. This is the other respect in
5507 -- which VADS_Size differs from Size.
5509 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
5510 Set_Attribute_Name (N, Name_Object_Size);
5512 -- In all other cases, Size and VADS_Size are the sane
5515 Set_Attribute_Name (N, Name_Size);
5520 -- If the prefix is X'Class, we transform it into a direct reference
5521 -- to the class-wide type, because the back end must not see a 'Class
5524 if Is_Entity_Name (Pref)
5525 and then Is_Class_Wide_Type (Entity (Pref))
5527 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
5530 -- For X'Size applied to an object of a class-wide type, transform
5531 -- X'Size into a call to the primitive operation _Size applied to X.
5533 elsif Is_Class_Wide_Type (Ptyp) then
5535 -- No need to do anything else compiling under restriction
5536 -- No_Dispatching_Calls. During the semantic analysis we
5537 -- already noted this restriction violation.
5539 if Restriction_Active (No_Dispatching_Calls) then
5544 Make_Function_Call (Loc,
5545 Name => New_Occurrence_Of
5546 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
5547 Parameter_Associations => New_List (Pref));
5549 if Typ /= Standard_Long_Long_Integer then
5551 -- The context is a specific integer type with which the
5552 -- original attribute was compatible. The function has a
5553 -- specific type as well, so to preserve the compatibility
5554 -- we must convert explicitly.
5556 New_Node := Convert_To (Typ, New_Node);
5559 Rewrite (N, New_Node);
5560 Analyze_And_Resolve (N, Typ);
5563 -- Case of known RM_Size of a type
5565 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
5566 and then Is_Entity_Name (Pref)
5567 and then Is_Type (Entity (Pref))
5568 and then Known_Static_RM_Size (Entity (Pref))
5570 Siz := RM_Size (Entity (Pref));
5572 -- Case of known Esize of a type
5574 elsif Id = Attribute_Object_Size
5575 and then Is_Entity_Name (Pref)
5576 and then Is_Type (Entity (Pref))
5577 and then Known_Static_Esize (Entity (Pref))
5579 Siz := Esize (Entity (Pref));
5581 -- Case of known size of object
5583 elsif Id = Attribute_Size
5584 and then Is_Entity_Name (Pref)
5585 and then Is_Object (Entity (Pref))
5586 and then Known_Esize (Entity (Pref))
5587 and then Known_Static_Esize (Entity (Pref))
5589 Siz := Esize (Entity (Pref));
5591 -- For an array component, we can do Size in the front end
5592 -- if the component_size of the array is set.
5594 elsif Nkind (Pref) = N_Indexed_Component then
5595 Siz := Component_Size (Etype (Prefix (Pref)));
5597 -- For a record component, we can do Size in the front end if there
5598 -- is a component clause, or if the record is packed and the
5599 -- component's size is known at compile time.
5601 elsif Nkind (Pref) = N_Selected_Component then
5603 Rec : constant Entity_Id := Etype (Prefix (Pref));
5604 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
5607 if Present (Component_Clause (Comp)) then
5608 Siz := Esize (Comp);
5610 elsif Is_Packed (Rec) then
5611 Siz := RM_Size (Ptyp);
5614 Apply_Universal_Integer_Attribute_Checks (N);
5619 -- All other cases are handled by the back end
5622 Apply_Universal_Integer_Attribute_Checks (N);
5624 -- If Size is applied to a formal parameter that is of a packed
5625 -- array subtype, then apply Size to the actual subtype.
5627 if Is_Entity_Name (Pref)
5628 and then Is_Formal (Entity (Pref))
5629 and then Is_Array_Type (Ptyp)
5630 and then Is_Packed (Ptyp)
5633 Make_Attribute_Reference (Loc,
5635 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
5636 Attribute_Name => Name_Size));
5637 Analyze_And_Resolve (N, Typ);
5640 -- If Size applies to a dereference of an access to unconstrained
5641 -- packed array, the back end needs to see its unconstrained
5642 -- nominal type, but also a hint to the actual constrained type.
5644 if Nkind (Pref) = N_Explicit_Dereference
5645 and then Is_Array_Type (Ptyp)
5646 and then not Is_Constrained (Ptyp)
5647 and then Is_Packed (Ptyp)
5649 Set_Actual_Designated_Subtype (Pref,
5650 Get_Actual_Subtype (Pref));
5656 -- Common processing for record and array component case
5658 if Siz /= No_Uint and then Siz /= 0 then
5660 CS : constant Boolean := Comes_From_Source (N);
5663 Rewrite (N, Make_Integer_Literal (Loc, Siz));
5665 -- This integer literal is not a static expression. We do not
5666 -- call Analyze_And_Resolve here, because this would activate
5667 -- the circuit for deciding that a static value was out of
5668 -- range, and we don't want that.
5670 -- So just manually set the type, mark the expression as non-
5671 -- static, and then ensure that the result is checked properly
5672 -- if the attribute comes from source (if it was internally
5673 -- generated, we never need a constraint check).
5676 Set_Is_Static_Expression (N, False);
5679 Apply_Constraint_Check (N, Typ);
5689 when Attribute_Storage_Pool =>
5691 Make_Type_Conversion (Loc,
5692 Subtype_Mark => New_Occurrence_Of (Etype (N), Loc),
5693 Expression => New_Occurrence_Of (Entity (N), Loc)));
5694 Analyze_And_Resolve (N, Typ);
5700 when Attribute_Storage_Size => Storage_Size : declare
5701 Alloc_Op : Entity_Id := Empty;
5705 -- Access type case, always go to the root type
5707 -- The case of access types results in a value of zero for the case
5708 -- where no storage size attribute clause has been given. If a
5709 -- storage size has been given, then the attribute is converted
5710 -- to a reference to the variable used to hold this value.
5712 if Is_Access_Type (Ptyp) then
5713 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
5715 Make_Attribute_Reference (Loc,
5716 Prefix => New_Occurrence_Of (Typ, Loc),
5717 Attribute_Name => Name_Max,
5718 Expressions => New_List (
5719 Make_Integer_Literal (Loc, 0),
5722 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
5724 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
5726 -- If the access type is associated with a simple storage pool
5727 -- object, then attempt to locate the optional Storage_Size
5728 -- function of the simple storage pool type. If not found,
5729 -- then the result will default to zero.
5731 if Present (Get_Rep_Pragma (Root_Type (Ptyp),
5732 Name_Simple_Storage_Pool_Type))
5735 Pool_Type : constant Entity_Id :=
5736 Base_Type (Etype (Entity (N)));
5739 Alloc_Op := Get_Name_Entity_Id (Name_Storage_Size);
5740 while Present (Alloc_Op) loop
5741 if Scope (Alloc_Op) = Scope (Pool_Type)
5742 and then Present (First_Formal (Alloc_Op))
5743 and then Etype (First_Formal (Alloc_Op)) = Pool_Type
5748 Alloc_Op := Homonym (Alloc_Op);
5752 -- In the normal Storage_Pool case, retrieve the primitive
5753 -- function associated with the pool type.
5758 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
5759 Attribute_Name (N));
5762 -- If Storage_Size wasn't found (can only occur in the simple
5763 -- storage pool case), then simply use zero for the result.
5765 if not Present (Alloc_Op) then
5766 Rewrite (N, Make_Integer_Literal (Loc, 0));
5768 -- Otherwise, rewrite the allocator as a call to pool type's
5769 -- Storage_Size function.
5774 Make_Function_Call (Loc,
5776 New_Occurrence_Of (Alloc_Op, Loc),
5778 Parameter_Associations => New_List (
5780 (Associated_Storage_Pool
5781 (Root_Type (Ptyp)), Loc)))));
5785 Rewrite (N, Make_Integer_Literal (Loc, 0));
5788 Analyze_And_Resolve (N, Typ);
5790 -- For tasks, we retrieve the size directly from the TCB. The
5791 -- size may depend on a discriminant of the type, and therefore
5792 -- can be a per-object expression, so type-level information is
5793 -- not sufficient in general. There are four cases to consider:
5795 -- a) If the attribute appears within a task body, the designated
5796 -- TCB is obtained by a call to Self.
5798 -- b) If the prefix of the attribute is the name of a task object,
5799 -- the designated TCB is the one stored in the corresponding record.
5801 -- c) If the prefix is a task type, the size is obtained from the
5802 -- size variable created for each task type
5804 -- d) If no Storage_Size was specified for the type, there is no
5805 -- size variable, and the value is a system-specific default.
5808 if In_Open_Scopes (Ptyp) then
5810 -- Storage_Size (Self)
5814 Make_Function_Call (Loc,
5816 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
5817 Parameter_Associations =>
5819 Make_Function_Call (Loc,
5821 New_Occurrence_Of (RTE (RE_Self), Loc))))));
5823 elsif not Is_Entity_Name (Pref)
5824 or else not Is_Type (Entity (Pref))
5826 -- Storage_Size (Rec (Obj).Size)
5830 Make_Function_Call (Loc,
5832 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
5833 Parameter_Associations =>
5835 Make_Selected_Component (Loc,
5837 Unchecked_Convert_To (
5838 Corresponding_Record_Type (Ptyp),
5839 New_Copy_Tree (Pref)),
5841 Make_Identifier (Loc, Name_uTask_Id))))));
5843 elsif Present (Storage_Size_Variable (Ptyp)) then
5845 -- Static Storage_Size pragma given for type: retrieve value
5846 -- from its allocated storage variable.
5850 Make_Function_Call (Loc,
5851 Name => New_Occurrence_Of (
5852 RTE (RE_Adjust_Storage_Size), Loc),
5853 Parameter_Associations =>
5856 Storage_Size_Variable (Ptyp), Loc)))));
5858 -- Get system default
5862 Make_Function_Call (Loc,
5865 RTE (RE_Default_Stack_Size), Loc))));
5868 Analyze_And_Resolve (N, Typ);
5876 when Attribute_Stream_Size =>
5878 Make_Integer_Literal (Loc, Intval => Get_Stream_Size (Ptyp)));
5879 Analyze_And_Resolve (N, Typ);
5885 -- 1. Deal with enumeration types with holes.
5886 -- 2. For floating-point, generate call to attribute function.
5887 -- 3. For other cases, deal with constraint checking.
5889 when Attribute_Succ => Succ : declare
5890 Etyp : constant Entity_Id := Base_Type (Ptyp);
5894 -- For enumeration types with non-standard representations, we
5895 -- expand typ'Succ (x) into
5897 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
5899 -- If the representation is contiguous, we compute instead
5900 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
5902 if Is_Enumeration_Type (Ptyp)
5903 and then Present (Enum_Pos_To_Rep (Etyp))
5905 if Has_Contiguous_Rep (Etyp) then
5907 Unchecked_Convert_To (Ptyp,
5910 Make_Integer_Literal (Loc,
5911 Enumeration_Rep (First_Literal (Ptyp))),
5913 Make_Function_Call (Loc,
5916 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
5918 Parameter_Associations =>
5920 Unchecked_Convert_To (Ptyp,
5923 Unchecked_Convert_To (Standard_Integer,
5924 Relocate_Node (First (Exprs))),
5926 Make_Integer_Literal (Loc, 1))),
5927 Rep_To_Pos_Flag (Ptyp, Loc))))));
5929 -- Add Boolean parameter True, to request program errror if
5930 -- we have a bad representation on our hands. Add False if
5931 -- checks are suppressed.
5933 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
5935 Make_Indexed_Component (Loc,
5938 (Enum_Pos_To_Rep (Etyp), Loc),
5939 Expressions => New_List (
5942 Make_Function_Call (Loc,
5945 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
5946 Parameter_Associations => Exprs),
5947 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
5950 Analyze_And_Resolve (N, Typ);
5952 -- For floating-point, we transform 'Succ into a call to the Succ
5953 -- floating-point attribute function in Fat_xxx (xxx is root type)
5955 elsif Is_Floating_Point_Type (Ptyp) then
5956 Expand_Fpt_Attribute_R (N);
5957 Analyze_And_Resolve (N, Typ);
5959 -- For modular types, nothing to do (no overflow, since wraps)
5961 elsif Is_Modular_Integer_Type (Ptyp) then
5964 -- For other types, if argument is marked as needing a range check or
5965 -- overflow checking is enabled, we must generate a check.
5967 elsif not Overflow_Checks_Suppressed (Ptyp)
5968 or else Do_Range_Check (First (Exprs))
5970 Set_Do_Range_Check (First (Exprs), False);
5971 Expand_Pred_Succ_Attribute (N);
5979 -- Transforms X'Tag into a direct reference to the tag of X
5981 when Attribute_Tag => Tag : declare
5983 Prefix_Is_Type : Boolean;
5986 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
5987 Ttyp := Entity (Pref);
5988 Prefix_Is_Type := True;
5991 Prefix_Is_Type := False;
5994 if Is_Class_Wide_Type (Ttyp) then
5995 Ttyp := Root_Type (Ttyp);
5998 Ttyp := Underlying_Type (Ttyp);
6000 -- Ada 2005: The type may be a synchronized tagged type, in which
6001 -- case the tag information is stored in the corresponding record.
6003 if Is_Concurrent_Type (Ttyp) then
6004 Ttyp := Corresponding_Record_Type (Ttyp);
6007 if Prefix_Is_Type then
6009 -- For VMs we leave the type attribute unexpanded because
6010 -- there's not a dispatching table to reference.
6012 if Tagged_Type_Expansion then
6014 Unchecked_Convert_To (RTE (RE_Tag),
6016 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
6017 Analyze_And_Resolve (N, RTE (RE_Tag));
6020 -- Ada 2005 (AI-251): The use of 'Tag in the sources always
6021 -- references the primary tag of the actual object. If 'Tag is
6022 -- applied to class-wide interface objects we generate code that
6023 -- displaces "this" to reference the base of the object.
6025 elsif Comes_From_Source (N)
6026 and then Is_Class_Wide_Type (Etype (Prefix (N)))
6027 and then Is_Interface (Etype (Prefix (N)))
6030 -- (To_Tag_Ptr (Prefix'Address)).all
6032 -- Note that Prefix'Address is recursively expanded into a call
6033 -- to Base_Address (Obj.Tag)
6035 -- Not needed for VM targets, since all handled by the VM
6037 if Tagged_Type_Expansion then
6039 Make_Explicit_Dereference (Loc,
6040 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
6041 Make_Attribute_Reference (Loc,
6042 Prefix => Relocate_Node (Pref),
6043 Attribute_Name => Name_Address))));
6044 Analyze_And_Resolve (N, RTE (RE_Tag));
6049 Make_Selected_Component (Loc,
6050 Prefix => Relocate_Node (Pref),
6052 New_Occurrence_Of (First_Tag_Component (Ttyp), Loc)));
6053 Analyze_And_Resolve (N, RTE (RE_Tag));
6061 -- Transforms 'Terminated attribute into a call to Terminated function
6063 when Attribute_Terminated => Terminated :
6065 -- The prefix of Terminated is of a task interface class-wide type.
6067 -- terminated (Task_Id (Pref._disp_get_task_id));
6069 if Ada_Version >= Ada_2005
6070 and then Ekind (Ptyp) = E_Class_Wide_Type
6071 and then Is_Interface (Ptyp)
6072 and then Is_Task_Interface (Ptyp)
6075 Make_Function_Call (Loc,
6077 New_Occurrence_Of (RTE (RE_Terminated), Loc),
6078 Parameter_Associations => New_List (
6079 Make_Unchecked_Type_Conversion (Loc,
6081 New_Occurrence_Of (RTE (RO_ST_Task_Id), Loc),
6083 Make_Selected_Component (Loc,
6085 New_Copy_Tree (Pref),
6087 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
6089 elsif Restricted_Profile then
6091 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
6095 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
6098 Analyze_And_Resolve (N, Standard_Boolean);
6105 -- Transforms System'To_Address (X) and System.Address'Ref (X) into
6106 -- unchecked conversion from (integral) type of X to type address.
6108 when Attribute_To_Address | Attribute_Ref =>
6110 Unchecked_Convert_To (RTE (RE_Address),
6111 Relocate_Node (First (Exprs))));
6112 Analyze_And_Resolve (N, RTE (RE_Address));
6118 when Attribute_To_Any => To_Any : declare
6119 P_Type : constant Entity_Id := Etype (Pref);
6120 Decls : constant List_Id := New_List;
6126 Relocate_Node (First (Exprs))), Decls));
6127 Insert_Actions (N, Decls);
6128 Analyze_And_Resolve (N, RTE (RE_Any));
6135 -- Transforms 'Truncation into a call to the floating-point attribute
6136 -- function Truncation in Fat_xxx (where xxx is the root type).
6137 -- Expansion is avoided for cases the back end can handle directly.
6139 when Attribute_Truncation =>
6140 if not Is_Inline_Floating_Point_Attribute (N) then
6141 Expand_Fpt_Attribute_R (N);
6148 when Attribute_TypeCode => TypeCode : declare
6149 P_Type : constant Entity_Id := Etype (Pref);
6150 Decls : constant List_Id := New_List;
6152 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
6153 Insert_Actions (N, Decls);
6154 Analyze_And_Resolve (N, RTE (RE_TypeCode));
6157 -----------------------
6158 -- Unbiased_Rounding --
6159 -----------------------
6161 -- Transforms 'Unbiased_Rounding into a call to the floating-point
6162 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
6163 -- root type). Expansion is avoided for cases the back end can handle
6166 when Attribute_Unbiased_Rounding =>
6167 if not Is_Inline_Floating_Point_Attribute (N) then
6168 Expand_Fpt_Attribute_R (N);
6175 when Attribute_Update =>
6176 Expand_Update_Attribute (N);
6182 -- The processing for VADS_Size is shared with Size
6188 -- For enumeration types with a standard representation, and for all
6189 -- other types, Val is handled by the back end. For enumeration types
6190 -- with a non-standard representation we use the _Pos_To_Rep array that
6191 -- was created when the type was frozen.
6193 when Attribute_Val => Val : declare
6194 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
6197 if Is_Enumeration_Type (Etyp)
6198 and then Present (Enum_Pos_To_Rep (Etyp))
6200 if Has_Contiguous_Rep (Etyp) then
6202 Rep_Node : constant Node_Id :=
6203 Unchecked_Convert_To (Etyp,
6206 Make_Integer_Literal (Loc,
6207 Enumeration_Rep (First_Literal (Etyp))),
6209 (Convert_To (Standard_Integer,
6210 Relocate_Node (First (Exprs))))));
6214 Unchecked_Convert_To (Etyp,
6217 Make_Integer_Literal (Loc,
6218 Enumeration_Rep (First_Literal (Etyp))),
6220 Make_Function_Call (Loc,
6223 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
6224 Parameter_Associations => New_List (
6226 Rep_To_Pos_Flag (Etyp, Loc))))));
6231 Make_Indexed_Component (Loc,
6232 Prefix => New_Occurrence_Of (Enum_Pos_To_Rep (Etyp), Loc),
6233 Expressions => New_List (
6234 Convert_To (Standard_Integer,
6235 Relocate_Node (First (Exprs))))));
6238 Analyze_And_Resolve (N, Typ);
6240 -- If the argument is marked as requiring a range check then generate
6243 elsif Do_Range_Check (First (Exprs)) then
6244 Generate_Range_Check (First (Exprs), Etyp, CE_Range_Check_Failed);
6252 -- The code for valid is dependent on the particular types involved.
6253 -- See separate sections below for the generated code in each case.
6255 when Attribute_Valid => Valid : declare
6256 Btyp : Entity_Id := Base_Type (Ptyp);
6259 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
6260 -- Save the validity checking mode. We always turn off validity
6261 -- checking during process of 'Valid since this is one place
6262 -- where we do not want the implicit validity checks to intefere
6263 -- with the explicit validity check that the programmer is doing.
6265 function Make_Range_Test return Node_Id;
6266 -- Build the code for a range test of the form
6267 -- Btyp!(Pref) in Btyp!(Ptyp'First) .. Btyp!(Ptyp'Last)
6269 ---------------------
6270 -- Make_Range_Test --
6271 ---------------------
6273 function Make_Range_Test return Node_Id is
6274 Temp : constant Node_Id := Duplicate_Subexpr (Pref);
6277 -- The value whose validity is being checked has been captured in
6278 -- an object declaration. We certainly don't want this object to
6279 -- appear valid because the declaration initializes it.
6281 if Is_Entity_Name (Temp) then
6282 Set_Is_Known_Valid (Entity (Temp), False);
6288 Unchecked_Convert_To (Btyp, Temp),
6292 Unchecked_Convert_To (Btyp,
6293 Make_Attribute_Reference (Loc,
6294 Prefix => New_Occurrence_Of (Ptyp, Loc),
6295 Attribute_Name => Name_First)),
6297 Unchecked_Convert_To (Btyp,
6298 Make_Attribute_Reference (Loc,
6299 Prefix => New_Occurrence_Of (Ptyp, Loc),
6300 Attribute_Name => Name_Last))));
6301 end Make_Range_Test;
6303 -- Start of processing for Attribute_Valid
6306 -- Do not expand sourced code 'Valid reference in CodePeer mode,
6307 -- will be handled by the back-end directly.
6309 if CodePeer_Mode and then Comes_From_Source (N) then
6313 -- Turn off validity checks. We do not want any implicit validity
6314 -- checks to intefere with the explicit check from the attribute
6316 Validity_Checks_On := False;
6318 -- Retrieve the base type. Handle the case where the base type is a
6319 -- private enumeration type.
6321 if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then
6322 Btyp := Full_View (Btyp);
6325 -- Floating-point case. This case is handled by the Valid attribute
6326 -- code in the floating-point attribute run-time library.
6328 if Is_Floating_Point_Type (Ptyp) then
6329 Float_Valid : declare
6333 function Get_Fat_Entity (Nam : Name_Id) return Entity_Id;
6334 -- Return entity for Pkg.Nam
6336 --------------------
6337 -- Get_Fat_Entity --
6338 --------------------
6340 function Get_Fat_Entity (Nam : Name_Id) return Entity_Id is
6341 Exp_Name : constant Node_Id :=
6342 Make_Selected_Component (Loc,
6343 Prefix => New_Occurrence_Of (RTE (Pkg), Loc),
6344 Selector_Name => Make_Identifier (Loc, Nam));
6346 Find_Selected_Component (Exp_Name);
6347 return Entity (Exp_Name);
6350 -- Start of processing for Float_Valid
6353 case Float_Rep (Btyp) is
6355 -- The AAMP back end handles Valid for floating-point types
6358 Analyze_And_Resolve (Pref, Ptyp);
6359 Set_Etype (N, Standard_Boolean);
6363 Find_Fat_Info (Ptyp, Ftp, Pkg);
6365 -- If the prefix is a reverse SSO component, or is
6366 -- possibly unaligned, first create a temporary copy
6367 -- that is in native SSO, and properly aligned. Make it
6368 -- Volatile to prevent folding in the back-end. Note
6369 -- that we use an intermediate constrained string type
6370 -- to initialize the temporary, as the value at hand
6371 -- might be invalid, and in that case it cannot be copied
6372 -- using a floating point register.
6374 if In_Reverse_Storage_Order_Object (Pref)
6376 Is_Possibly_Unaligned_Object (Pref)
6379 Temp : constant Entity_Id :=
6380 Make_Temporary (Loc, 'F');
6382 Fat_S : constant Entity_Id :=
6383 Get_Fat_Entity (Name_S);
6384 -- Constrained string subtype of appropriate size
6386 Fat_P : constant Entity_Id :=
6387 Get_Fat_Entity (Name_P);
6390 Decl : constant Node_Id :=
6391 Make_Object_Declaration (Loc,
6392 Defining_Identifier => Temp,
6393 Aliased_Present => True,
6394 Object_Definition =>
6395 New_Occurrence_Of (Ptyp, Loc));
6398 Set_Aspect_Specifications (Decl, New_List (
6399 Make_Aspect_Specification (Loc,
6401 Make_Identifier (Loc, Name_Volatile))));
6407 Make_Assignment_Statement (Loc,
6409 Make_Explicit_Dereference (Loc,
6411 Unchecked_Convert_To (Fat_P,
6412 Make_Attribute_Reference (Loc,
6414 New_Occurrence_Of (Temp, Loc),
6416 Name_Unrestricted_Access))),
6418 Unchecked_Convert_To (Fat_S,
6419 Relocate_Node (Pref)))),
6421 Suppress => All_Checks);
6423 Rewrite (Pref, New_Occurrence_Of (Temp, Loc));
6427 -- We now have an object of the proper endianness and
6428 -- alignment, and can construct a Valid attribute.
6430 -- We make sure the prefix of this valid attribute is
6431 -- marked as not coming from source, to avoid losing
6432 -- warnings from 'Valid looking like a possible update.
6434 Set_Comes_From_Source (Pref, False);
6436 Expand_Fpt_Attribute
6437 (N, Pkg, Name_Valid,
6439 Make_Attribute_Reference (Loc,
6440 Prefix => Unchecked_Convert_To (Ftp, Pref),
6441 Attribute_Name => Name_Unrestricted_Access)));
6444 -- One more task, we still need a range check. Required
6445 -- only if we have a constraint, since the Valid routine
6446 -- catches infinities properly (infinities are never valid).
6448 -- The way we do the range check is simply to create the
6449 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
6451 if not Subtypes_Statically_Match (Ptyp, Btyp) then
6454 Left_Opnd => Relocate_Node (N),
6457 Left_Opnd => Convert_To (Btyp, Pref),
6458 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
6462 -- Enumeration type with holes
6464 -- For enumeration types with holes, the Pos value constructed by
6465 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
6466 -- second argument of False returns minus one for an invalid value,
6467 -- and the non-negative pos value for a valid value, so the
6468 -- expansion of X'Valid is simply:
6470 -- type(X)'Pos (X) >= 0
6472 -- We can't quite generate it that way because of the requirement
6473 -- for the non-standard second argument of False in the resulting
6474 -- rep_to_pos call, so we have to explicitly create:
6476 -- _rep_to_pos (X, False) >= 0
6478 -- If we have an enumeration subtype, we also check that the
6479 -- value is in range:
6481 -- _rep_to_pos (X, False) >= 0
6483 -- (X >= type(X)'First and then type(X)'Last <= X)
6485 elsif Is_Enumeration_Type (Ptyp)
6486 and then Present (Enum_Pos_To_Rep (Btyp))
6491 Make_Function_Call (Loc,
6493 New_Occurrence_Of (TSS (Btyp, TSS_Rep_To_Pos), Loc),
6494 Parameter_Associations => New_List (
6496 New_Occurrence_Of (Standard_False, Loc))),
6497 Right_Opnd => Make_Integer_Literal (Loc, 0));
6501 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
6503 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
6505 -- The call to Make_Range_Test will create declarations
6506 -- that need a proper insertion point, but Pref is now
6507 -- attached to a node with no ancestor. Attach to tree
6508 -- even if it is to be rewritten below.
6510 Set_Parent (Tst, Parent (N));
6514 Left_Opnd => Make_Range_Test,
6520 -- Fortran convention booleans
6522 -- For the very special case of Fortran convention booleans, the
6523 -- value is always valid, since it is an integer with the semantics
6524 -- that non-zero is true, and any value is permissible.
6526 elsif Is_Boolean_Type (Ptyp)
6527 and then Convention (Ptyp) = Convention_Fortran
6529 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
6531 -- For biased representations, we will be doing an unchecked
6532 -- conversion without unbiasing the result. That means that the range
6533 -- test has to take this into account, and the proper form of the
6536 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
6538 elsif Has_Biased_Representation (Ptyp) then
6539 Btyp := RTE (RE_Unsigned_32);
6543 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
6545 Unchecked_Convert_To (Btyp,
6546 Make_Attribute_Reference (Loc,
6547 Prefix => New_Occurrence_Of (Ptyp, Loc),
6548 Attribute_Name => Name_Range_Length))));
6550 -- For all other scalar types, what we want logically is a
6553 -- X in type(X)'First .. type(X)'Last
6555 -- But that's precisely what won't work because of possible
6556 -- unwanted optimization (and indeed the basic motivation for
6557 -- the Valid attribute is exactly that this test does not work).
6558 -- What will work is:
6560 -- Btyp!(X) >= Btyp!(type(X)'First)
6562 -- Btyp!(X) <= Btyp!(type(X)'Last)
6564 -- where Btyp is an integer type large enough to cover the full
6565 -- range of possible stored values (i.e. it is chosen on the basis
6566 -- of the size of the type, not the range of the values). We write
6567 -- this as two tests, rather than a range check, so that static
6568 -- evaluation will easily remove either or both of the checks if
6569 -- they can be -statically determined to be true (this happens
6570 -- when the type of X is static and the range extends to the full
6571 -- range of stored values).
6573 -- Unsigned types. Note: it is safe to consider only whether the
6574 -- subtype is unsigned, since we will in that case be doing all
6575 -- unsigned comparisons based on the subtype range. Since we use the
6576 -- actual subtype object size, this is appropriate.
6578 -- For example, if we have
6580 -- subtype x is integer range 1 .. 200;
6581 -- for x'Object_Size use 8;
6583 -- Now the base type is signed, but objects of this type are bits
6584 -- unsigned, and doing an unsigned test of the range 1 to 200 is
6585 -- correct, even though a value greater than 127 looks signed to a
6586 -- signed comparison.
6588 elsif Is_Unsigned_Type (Ptyp) then
6589 if Esize (Ptyp) <= 32 then
6590 Btyp := RTE (RE_Unsigned_32);
6592 Btyp := RTE (RE_Unsigned_64);
6595 Rewrite (N, Make_Range_Test);
6600 if Esize (Ptyp) <= Esize (Standard_Integer) then
6601 Btyp := Standard_Integer;
6603 Btyp := Universal_Integer;
6606 Rewrite (N, Make_Range_Test);
6609 -- If a predicate is present, then we do the predicate test, even if
6610 -- within the predicate function (infinite recursion is warned about
6611 -- in Sem_Attr in that case).
6614 Pred_Func : constant Entity_Id := Predicate_Function (Ptyp);
6617 if Present (Pred_Func) then
6620 Left_Opnd => Relocate_Node (N),
6621 Right_Opnd => Make_Predicate_Call (Ptyp, Pref)));
6625 Analyze_And_Resolve (N, Standard_Boolean);
6626 Validity_Checks_On := Save_Validity_Checks_On;
6633 when Attribute_Valid_Scalars => Valid_Scalars : declare
6637 if Present (Underlying_Type (Ptyp)) then
6638 Ftyp := Underlying_Type (Ptyp);
6643 -- Replace by True if no scalar parts
6645 if not Scalar_Part_Present (Ftyp) then
6646 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
6648 -- For scalar types, Valid_Scalars is the same as Valid
6650 elsif Is_Scalar_Type (Ftyp) then
6652 Make_Attribute_Reference (Loc,
6653 Attribute_Name => Name_Valid,
6656 -- For array types, we construct a function that determines if there
6657 -- are any non-valid scalar subcomponents, and call the function.
6658 -- We only do this for arrays whose component type needs checking
6660 elsif Is_Array_Type (Ftyp)
6661 and then Scalar_Part_Present (Component_Type (Ftyp))
6664 Make_Function_Call (Loc,
6666 New_Occurrence_Of (Build_Array_VS_Func (Ftyp, N), Loc),
6667 Parameter_Associations => New_List (Pref)));
6669 -- For record types, we construct a function that determines if there
6670 -- are any non-valid scalar subcomponents, and call the function.
6672 elsif Is_Record_Type (Ftyp)
6673 and then Nkind (Type_Definition (Declaration_Node (Ftyp))) =
6677 Make_Function_Call (Loc,
6679 New_Occurrence_Of (Build_Record_VS_Func (Ftyp, N), Loc),
6680 Parameter_Associations => New_List (Pref)));
6682 -- Other record types or types with discriminants
6684 elsif Is_Record_Type (Ftyp) or else Has_Discriminants (Ptyp) then
6686 -- Build expression with list of equality tests
6694 X := New_Occurrence_Of (Standard_True, Loc);
6695 C := First_Component_Or_Discriminant (Ptyp);
6696 while Present (C) loop
6697 if not Scalar_Part_Present (Etype (C)) then
6699 elsif Is_Scalar_Type (Etype (C)) then
6702 A := Name_Valid_Scalars;
6709 Make_Attribute_Reference (Loc,
6710 Attribute_Name => A,
6712 Make_Selected_Component (Loc,
6714 Duplicate_Subexpr (Pref, Name_Req => True),
6716 New_Occurrence_Of (C, Loc))));
6718 Next_Component_Or_Discriminant (C);
6724 -- For all other types, result is True
6727 Rewrite (N, New_Occurrence_Of (Standard_Boolean, Loc));
6730 -- Result is always boolean, but never static
6732 Analyze_And_Resolve (N, Standard_Boolean);
6733 Set_Is_Static_Expression (N, False);
6740 -- Value attribute is handled in separate unit Exp_Imgv
6742 when Attribute_Value =>
6743 Exp_Imgv.Expand_Value_Attribute (N);
6749 -- The processing for Value_Size shares the processing for Size
6755 -- The processing for Version shares the processing for Body_Version
6761 -- Wide_Image attribute is handled in separate unit Exp_Imgv
6763 when Attribute_Wide_Image =>
6764 Exp_Imgv.Expand_Wide_Image_Attribute (N);
6766 ---------------------
6767 -- Wide_Wide_Image --
6768 ---------------------
6770 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
6772 when Attribute_Wide_Wide_Image =>
6773 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
6779 -- We expand typ'Wide_Value (X) into
6782 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
6784 -- Wide_String_To_String is a runtime function that converts its wide
6785 -- string argument to String, converting any non-translatable characters
6786 -- into appropriate escape sequences. This preserves the required
6787 -- semantics of Wide_Value in all cases, and results in a very simple
6788 -- implementation approach.
6790 -- Note: for this approach to be fully standard compliant for the cases
6791 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
6792 -- method must cover the entire character range (e.g. UTF-8). But that
6793 -- is a reasonable requirement when dealing with encoded character
6794 -- sequences. Presumably if one of the restrictive encoding mechanisms
6795 -- is in use such as Shift-JIS, then characters that cannot be
6796 -- represented using this encoding will not appear in any case.
6798 when Attribute_Wide_Value => Wide_Value :
6801 Make_Attribute_Reference (Loc,
6803 Attribute_Name => Name_Value,
6805 Expressions => New_List (
6806 Make_Function_Call (Loc,
6808 New_Occurrence_Of (RTE (RE_Wide_String_To_String), Loc),
6810 Parameter_Associations => New_List (
6811 Relocate_Node (First (Exprs)),
6812 Make_Integer_Literal (Loc,
6813 Intval => Int (Wide_Character_Encoding_Method)))))));
6815 Analyze_And_Resolve (N, Typ);
6818 ---------------------
6819 -- Wide_Wide_Value --
6820 ---------------------
6822 -- We expand typ'Wide_Value_Value (X) into
6825 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
6827 -- Wide_Wide_String_To_String is a runtime function that converts its
6828 -- wide string argument to String, converting any non-translatable
6829 -- characters into appropriate escape sequences. This preserves the
6830 -- required semantics of Wide_Wide_Value in all cases, and results in a
6831 -- very simple implementation approach.
6833 -- It's not quite right where typ = Wide_Wide_Character, because the
6834 -- encoding method may not cover the whole character type ???
6836 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
6839 Make_Attribute_Reference (Loc,
6841 Attribute_Name => Name_Value,
6843 Expressions => New_List (
6844 Make_Function_Call (Loc,
6847 (RTE (RE_Wide_Wide_String_To_String), Loc),
6849 Parameter_Associations => New_List (
6850 Relocate_Node (First (Exprs)),
6851 Make_Integer_Literal (Loc,
6852 Intval => Int (Wide_Character_Encoding_Method)))))));
6854 Analyze_And_Resolve (N, Typ);
6855 end Wide_Wide_Value;
6857 ---------------------
6858 -- Wide_Wide_Width --
6859 ---------------------
6861 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
6863 when Attribute_Wide_Wide_Width =>
6864 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
6870 -- Wide_Width attribute is handled in separate unit Exp_Imgv
6872 when Attribute_Wide_Width =>
6873 Exp_Imgv.Expand_Width_Attribute (N, Wide);
6879 -- Width attribute is handled in separate unit Exp_Imgv
6881 when Attribute_Width =>
6882 Exp_Imgv.Expand_Width_Attribute (N, Normal);
6888 when Attribute_Write => Write : declare
6889 P_Type : constant Entity_Id := Entity (Pref);
6890 U_Type : constant Entity_Id := Underlying_Type (P_Type);
6898 -- If no underlying type, we have an error that will be diagnosed
6899 -- elsewhere, so here we just completely ignore the expansion.
6905 -- Stream operations can appear in user code even if the restriction
6906 -- No_Streams is active (for example, when instantiating a predefined
6907 -- container). In that case rewrite the attribute as a Raise to
6908 -- prevent any run-time use.
6910 if Restriction_Active (No_Streams) then
6912 Make_Raise_Program_Error (Sloc (N),
6913 Reason => PE_Stream_Operation_Not_Allowed));
6914 Set_Etype (N, U_Type);
6918 -- The simple case, if there is a TSS for Write, just call it
6920 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
6922 if Present (Pname) then
6926 -- If there is a Stream_Convert pragma, use it, we rewrite
6928 -- sourcetyp'Output (stream, Item)
6932 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
6934 -- where strmwrite is the given Write function that converts an
6935 -- argument of type sourcetyp or a type acctyp, from which it is
6936 -- derived to type strmtyp. The conversion to acttyp is required
6937 -- for the derived case.
6939 Prag := Get_Stream_Convert_Pragma (P_Type);
6941 if Present (Prag) then
6943 Next (Next (First (Pragma_Argument_Associations (Prag))));
6944 Wfunc := Entity (Expression (Arg3));
6947 Make_Attribute_Reference (Loc,
6948 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
6949 Attribute_Name => Name_Output,
6950 Expressions => New_List (
6951 Relocate_Node (First (Exprs)),
6952 Make_Function_Call (Loc,
6953 Name => New_Occurrence_Of (Wfunc, Loc),
6954 Parameter_Associations => New_List (
6955 OK_Convert_To (Etype (First_Formal (Wfunc)),
6956 Relocate_Node (Next (First (Exprs)))))))));
6961 -- For elementary types, we call the W_xxx routine directly
6963 elsif Is_Elementary_Type (U_Type) then
6964 Rewrite (N, Build_Elementary_Write_Call (N));
6970 elsif Is_Array_Type (U_Type) then
6971 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
6972 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
6974 -- Tagged type case, use the primitive Write function. Note that
6975 -- this will dispatch in the class-wide case which is what we want
6977 elsif Is_Tagged_Type (U_Type) then
6978 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
6980 -- All other record type cases, including protected records.
6981 -- The latter only arise for expander generated code for
6982 -- handling shared passive partition access.
6986 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
6988 -- Ada 2005 (AI-216): Program_Error is raised when executing
6989 -- the default implementation of the Write attribute of an
6990 -- Unchecked_Union type. However, if the 'Write reference is
6991 -- within the generated Output stream procedure, Write outputs
6992 -- the components, and the default values of the discriminant
6993 -- are streamed by the Output procedure itself.
6995 if Is_Unchecked_Union (Base_Type (U_Type))
6996 and not Is_TSS (Current_Scope, TSS_Stream_Output)
6999 Make_Raise_Program_Error (Loc,
7000 Reason => PE_Unchecked_Union_Restriction));
7003 if Has_Discriminants (U_Type)
7005 (Discriminant_Default_Value (First_Discriminant (U_Type)))
7007 Build_Mutable_Record_Write_Procedure
7008 (Loc, Full_Base (U_Type), Decl, Pname);
7010 Build_Record_Write_Procedure
7011 (Loc, Full_Base (U_Type), Decl, Pname);
7014 Insert_Action (N, Decl);
7018 -- If we fall through, Pname is the procedure to be called
7020 Rewrite_Stream_Proc_Call (Pname);
7023 -- Component_Size is handled by the back end, unless the component size
7024 -- is known at compile time, which is always true in the packed array
7025 -- case. It is important that the packed array case is handled in the
7026 -- front end (see Eval_Attribute) since the back end would otherwise get
7027 -- confused by the equivalent packed array type.
7029 when Attribute_Component_Size =>
7032 -- The following attributes are handled by the back end (except that
7033 -- static cases have already been evaluated during semantic processing,
7034 -- but in any case the back end should not count on this).
7036 -- The back end also handles the non-class-wide cases of Size
7038 when Attribute_Bit_Order |
7039 Attribute_Code_Address |
7040 Attribute_Definite |
7042 Attribute_Null_Parameter |
7043 Attribute_Passed_By_Reference |
7044 Attribute_Pool_Address |
7045 Attribute_Scalar_Storage_Order =>
7048 -- The following attributes are also handled by the back end, but return
7049 -- a universal integer result, so may need a conversion for checking
7050 -- that the result is in range.
7052 when Attribute_Aft |
7053 Attribute_Max_Alignment_For_Allocation =>
7054 Apply_Universal_Integer_Attribute_Checks (N);
7056 -- The following attributes should not appear at this stage, since they
7057 -- have already been handled by the analyzer (and properly rewritten
7058 -- with corresponding values or entities to represent the right values)
7060 when Attribute_Abort_Signal |
7061 Attribute_Address_Size |
7062 Attribute_Atomic_Always_Lock_Free |
7065 Attribute_Compiler_Version |
7066 Attribute_Default_Bit_Order |
7067 Attribute_Default_Scalar_Storage_Order |
7074 Attribute_Fast_Math |
7075 Attribute_First_Valid |
7076 Attribute_Has_Access_Values |
7077 Attribute_Has_Discriminants |
7078 Attribute_Has_Tagged_Values |
7080 Attribute_Last_Valid |
7081 Attribute_Library_Level |
7082 Attribute_Lock_Free |
7083 Attribute_Machine_Emax |
7084 Attribute_Machine_Emin |
7085 Attribute_Machine_Mantissa |
7086 Attribute_Machine_Overflows |
7087 Attribute_Machine_Radix |
7088 Attribute_Machine_Rounds |
7089 Attribute_Maximum_Alignment |
7090 Attribute_Model_Emin |
7091 Attribute_Model_Epsilon |
7092 Attribute_Model_Mantissa |
7093 Attribute_Model_Small |
7095 Attribute_Partition_ID |
7097 Attribute_Restriction_Set |
7098 Attribute_Safe_Emax |
7099 Attribute_Safe_First |
7100 Attribute_Safe_Large |
7101 Attribute_Safe_Last |
7102 Attribute_Safe_Small |
7104 Attribute_Signed_Zeros |
7106 Attribute_Storage_Unit |
7107 Attribute_Stub_Type |
7108 Attribute_System_Allocator_Alignment |
7109 Attribute_Target_Name |
7110 Attribute_Type_Class |
7111 Attribute_Type_Key |
7112 Attribute_Unconstrained_Array |
7113 Attribute_Universal_Literal_String |
7114 Attribute_Wchar_T_Size |
7115 Attribute_Word_Size =>
7116 raise Program_Error;
7118 -- The Asm_Input and Asm_Output attributes are not expanded at this
7119 -- stage, but will be eliminated in the expansion of the Asm call, see
7120 -- Exp_Intr for details. So the back end will never see these either.
7122 when Attribute_Asm_Input |
7123 Attribute_Asm_Output =>
7127 -- Note: as mentioned earlier, individual sections of the above case
7128 -- statement assume there is no code after the case statement, and are
7129 -- legitimately allowed to execute return statements if they have nothing
7130 -- more to do, so DO NOT add code at this point.
7133 when RE_Not_Available =>
7135 end Expand_N_Attribute_Reference;
7137 --------------------------------
7138 -- Expand_Pred_Succ_Attribute --
7139 --------------------------------
7141 -- For typ'Pred (exp), we generate the check
7143 -- [constraint_error when exp = typ'Base'First]
7145 -- Similarly, for typ'Succ (exp), we generate the check
7147 -- [constraint_error when exp = typ'Base'Last]
7149 -- These checks are not generated for modular types, since the proper
7150 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
7151 -- We also suppress these checks if we are the right side of an assignment
7152 -- statement or the expression of an object declaration, where the flag
7153 -- Suppress_Assignment_Checks is set for the assignment/declaration.
7155 procedure Expand_Pred_Succ_Attribute (N : Node_Id) is
7156 Loc : constant Source_Ptr := Sloc (N);
7157 P : constant Node_Id := Parent (N);
7161 if Attribute_Name (N) = Name_Pred then
7167 if not Nkind_In (P, N_Assignment_Statement, N_Object_Declaration)
7168 or else not Suppress_Assignment_Checks (P)
7171 Make_Raise_Constraint_Error (Loc,
7175 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
7177 Make_Attribute_Reference (Loc,
7179 New_Occurrence_Of (Base_Type (Etype (Prefix (N))), Loc),
7180 Attribute_Name => Cnam)),
7181 Reason => CE_Overflow_Check_Failed));
7183 end Expand_Pred_Succ_Attribute;
7185 -----------------------------
7186 -- Expand_Update_Attribute --
7187 -----------------------------
7189 procedure Expand_Update_Attribute (N : Node_Id) is
7190 procedure Process_Component_Or_Element_Update
7195 -- Generate the statements necessary to update a single component or an
7196 -- element of the prefix. The code is inserted before the attribute N.
7197 -- Temp denotes the entity of the anonymous object created to reflect
7198 -- the changes in values. Comp is the component/index expression to be
7199 -- updated. Expr is an expression yielding the new value of Comp. Typ
7200 -- is the type of the prefix of attribute Update.
7202 procedure Process_Range_Update
7207 -- Generate the statements necessary to update a slice of the prefix.
7208 -- The code is inserted before the attribute N. Temp denotes the entity
7209 -- of the anonymous object created to reflect the changes in values.
7210 -- Comp is range of the slice to be updated. Expr is an expression
7211 -- yielding the new value of Comp. Typ is the type of the prefix of
7212 -- attribute Update.
7214 -----------------------------------------
7215 -- Process_Component_Or_Element_Update --
7216 -----------------------------------------
7218 procedure Process_Component_Or_Element_Update
7224 Loc : constant Source_Ptr := Sloc (Comp);
7229 -- An array element may be modified by the following relations
7230 -- depending on the number of dimensions:
7232 -- 1 => Expr -- one dimensional update
7233 -- (1, ..., N) => Expr -- multi dimensional update
7235 -- The above forms are converted in assignment statements where the
7236 -- left hand side is an indexed component:
7238 -- Temp (1) := Expr; -- one dimensional update
7239 -- Temp (1, ..., N) := Expr; -- multi dimensional update
7241 if Is_Array_Type (Typ) then
7243 -- The index expressions of a multi dimensional array update
7244 -- appear as an aggregate.
7246 if Nkind (Comp) = N_Aggregate then
7247 Exprs := New_Copy_List_Tree (Expressions (Comp));
7249 Exprs := New_List (Relocate_Node (Comp));
7253 Make_Indexed_Component (Loc,
7254 Prefix => New_Occurrence_Of (Temp, Loc),
7255 Expressions => Exprs);
7257 -- A record component update appears in the following form:
7261 -- The above relation is transformed into an assignment statement
7262 -- where the left hand side is a selected component:
7264 -- Temp.Comp := Expr;
7266 else pragma Assert (Is_Record_Type (Typ));
7268 Make_Selected_Component (Loc,
7269 Prefix => New_Occurrence_Of (Temp, Loc),
7270 Selector_Name => Relocate_Node (Comp));
7274 Make_Assignment_Statement (Loc,
7276 Expression => Relocate_Node (Expr)));
7277 end Process_Component_Or_Element_Update;
7279 --------------------------
7280 -- Process_Range_Update --
7281 --------------------------
7283 procedure Process_Range_Update
7289 Index_Typ : constant Entity_Id := Etype (First_Index (Typ));
7290 Loc : constant Source_Ptr := Sloc (Comp);
7294 -- A range update appears as
7296 -- (Low .. High => Expr)
7298 -- The above construct is transformed into a loop that iterates over
7299 -- the given range and modifies the corresponding array values to the
7302 -- for Index in Low .. High loop
7303 -- Temp (<Index_Typ> (Index)) := Expr;
7306 Index := Make_Temporary (Loc, 'I');
7309 Make_Loop_Statement (Loc,
7311 Make_Iteration_Scheme (Loc,
7312 Loop_Parameter_Specification =>
7313 Make_Loop_Parameter_Specification (Loc,
7314 Defining_Identifier => Index,
7315 Discrete_Subtype_Definition => Relocate_Node (Comp))),
7317 Statements => New_List (
7318 Make_Assignment_Statement (Loc,
7320 Make_Indexed_Component (Loc,
7321 Prefix => New_Occurrence_Of (Temp, Loc),
7322 Expressions => New_List (
7323 Convert_To (Index_Typ,
7324 New_Occurrence_Of (Index, Loc)))),
7325 Expression => Relocate_Node (Expr))),
7327 End_Label => Empty));
7328 end Process_Range_Update;
7332 Aggr : constant Node_Id := First (Expressions (N));
7333 Loc : constant Source_Ptr := Sloc (N);
7334 Pref : constant Node_Id := Prefix (N);
7335 Typ : constant Entity_Id := Etype (Pref);
7338 CW_Temp : Entity_Id;
7343 -- Start of processing for Expand_Update_Attribute
7346 -- Create the anonymous object to store the value of the prefix and
7347 -- capture subsequent changes in value.
7349 Temp := Make_Temporary (Loc, 'T', Pref);
7351 -- Preserve the tag of the prefix by offering a specific view of the
7352 -- class-wide version of the prefix.
7354 if Is_Tagged_Type (Typ) then
7357 -- CW_Temp : Typ'Class := Typ'Class (Pref);
7359 CW_Temp := Make_Temporary (Loc, 'T');
7360 CW_Typ := Class_Wide_Type (Typ);
7363 Make_Object_Declaration (Loc,
7364 Defining_Identifier => CW_Temp,
7365 Object_Definition => New_Occurrence_Of (CW_Typ, Loc),
7367 Convert_To (CW_Typ, Relocate_Node (Pref))));
7370 -- Temp : Typ renames Typ (CW_Temp);
7373 Make_Object_Renaming_Declaration (Loc,
7374 Defining_Identifier => Temp,
7375 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
7377 Convert_To (Typ, New_Occurrence_Of (CW_Temp, Loc))));
7383 -- Temp : Typ := Pref;
7386 Make_Object_Declaration (Loc,
7387 Defining_Identifier => Temp,
7388 Object_Definition => New_Occurrence_Of (Typ, Loc),
7389 Expression => Relocate_Node (Pref)));
7392 -- Process the update aggregate
7394 Assoc := First (Component_Associations (Aggr));
7395 while Present (Assoc) loop
7396 Comp := First (Choices (Assoc));
7397 Expr := Expression (Assoc);
7398 while Present (Comp) loop
7399 if Nkind (Comp) = N_Range then
7400 Process_Range_Update (Temp, Comp, Expr, Typ);
7402 Process_Component_Or_Element_Update (Temp, Comp, Expr, Typ);
7411 -- The attribute is replaced by a reference to the anonymous object
7413 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7415 end Expand_Update_Attribute;
7421 procedure Find_Fat_Info
7423 Fat_Type : out Entity_Id;
7424 Fat_Pkg : out RE_Id)
7426 Rtyp : constant Entity_Id := Root_Type (T);
7429 -- All we do is use the root type (historically this dealt with
7430 -- VAX-float .. to be cleaned up further later ???)
7434 if Fat_Type = Standard_Short_Float then
7435 Fat_Pkg := RE_Attr_Short_Float;
7437 elsif Fat_Type = Standard_Float then
7438 Fat_Pkg := RE_Attr_Float;
7440 elsif Fat_Type = Standard_Long_Float then
7441 Fat_Pkg := RE_Attr_Long_Float;
7443 elsif Fat_Type = Standard_Long_Long_Float then
7444 Fat_Pkg := RE_Attr_Long_Long_Float;
7446 -- Universal real (which is its own root type) is treated as being
7447 -- equivalent to Standard.Long_Long_Float, since it is defined to
7448 -- have the same precision as the longest Float type.
7450 elsif Fat_Type = Universal_Real then
7451 Fat_Type := Standard_Long_Long_Float;
7452 Fat_Pkg := RE_Attr_Long_Long_Float;
7455 raise Program_Error;
7459 ----------------------------
7460 -- Find_Stream_Subprogram --
7461 ----------------------------
7463 function Find_Stream_Subprogram
7465 Nam : TSS_Name_Type) return Entity_Id
7467 Base_Typ : constant Entity_Id := Base_Type (Typ);
7468 Ent : constant Entity_Id := TSS (Typ, Nam);
7470 function Is_Available (Entity : RE_Id) return Boolean;
7471 pragma Inline (Is_Available);
7472 -- Function to check whether the specified run-time call is available
7473 -- in the run time used. In the case of a configurable run time, it
7474 -- is normal that some subprograms are not there.
7476 -- I don't understand this routine at all, why is this not just a
7477 -- call to RTE_Available? And if for some reason we need a different
7478 -- routine with different semantics, why is not in Rtsfind ???
7484 function Is_Available (Entity : RE_Id) return Boolean is
7486 -- Assume that the unit will always be available when using a
7487 -- "normal" (not configurable) run time.
7489 return not Configurable_Run_Time_Mode or else RTE_Available (Entity);
7492 -- Start of processing for Find_Stream_Subprogram
7495 if Present (Ent) then
7499 -- Stream attributes for strings are expanded into library calls. The
7500 -- following checks are disabled when the run-time is not available or
7501 -- when compiling predefined types due to bootstrap issues. As a result,
7502 -- the compiler will generate in-place stream routines for string types
7503 -- that appear in GNAT's library, but will generate calls via rtsfind
7504 -- to library routines for user code.
7506 -- This is disabled for AAMP, to avoid creating dependences on files not
7507 -- supported in the AAMP library (such as s-fileio.adb).
7509 -- Note: In the case of using a configurable run time, it is very likely
7510 -- that stream routines for string types are not present (they require
7511 -- file system support). In this case, the specific stream routines for
7512 -- strings are not used, relying on the regular stream mechanism
7513 -- instead. That is why we include the test Is_Available when dealing
7514 -- with these cases.
7516 if not AAMP_On_Target
7518 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
7520 -- Storage_Array as defined in package System.Storage_Elements
7522 if Is_RTE (Base_Typ, RE_Storage_Array) then
7524 -- Case of No_Stream_Optimizations restriction active
7526 if Restriction_Active (No_Stream_Optimizations) then
7527 if Nam = TSS_Stream_Input
7528 and then Is_Available (RE_Storage_Array_Input)
7530 return RTE (RE_Storage_Array_Input);
7532 elsif Nam = TSS_Stream_Output
7533 and then Is_Available (RE_Storage_Array_Output)
7535 return RTE (RE_Storage_Array_Output);
7537 elsif Nam = TSS_Stream_Read
7538 and then Is_Available (RE_Storage_Array_Read)
7540 return RTE (RE_Storage_Array_Read);
7542 elsif Nam = TSS_Stream_Write
7543 and then Is_Available (RE_Storage_Array_Write)
7545 return RTE (RE_Storage_Array_Write);
7547 elsif Nam /= TSS_Stream_Input and then
7548 Nam /= TSS_Stream_Output and then
7549 Nam /= TSS_Stream_Read and then
7550 Nam /= TSS_Stream_Write
7552 raise Program_Error;
7555 -- Restriction No_Stream_Optimizations is not set, so we can go
7556 -- ahead and optimize using the block IO forms of the routines.
7559 if Nam = TSS_Stream_Input
7560 and then Is_Available (RE_Storage_Array_Input_Blk_IO)
7562 return RTE (RE_Storage_Array_Input_Blk_IO);
7564 elsif Nam = TSS_Stream_Output
7565 and then Is_Available (RE_Storage_Array_Output_Blk_IO)
7567 return RTE (RE_Storage_Array_Output_Blk_IO);
7569 elsif Nam = TSS_Stream_Read
7570 and then Is_Available (RE_Storage_Array_Read_Blk_IO)
7572 return RTE (RE_Storage_Array_Read_Blk_IO);
7574 elsif Nam = TSS_Stream_Write
7575 and then Is_Available (RE_Storage_Array_Write_Blk_IO)
7577 return RTE (RE_Storage_Array_Write_Blk_IO);
7579 elsif Nam /= TSS_Stream_Input and then
7580 Nam /= TSS_Stream_Output and then
7581 Nam /= TSS_Stream_Read and then
7582 Nam /= TSS_Stream_Write
7584 raise Program_Error;
7588 -- Stream_Element_Array as defined in package Ada.Streams
7590 elsif Is_RTE (Base_Typ, RE_Stream_Element_Array) then
7592 -- Case of No_Stream_Optimizations restriction active
7594 if Restriction_Active (No_Stream_Optimizations) then
7595 if Nam = TSS_Stream_Input
7596 and then Is_Available (RE_Stream_Element_Array_Input)
7598 return RTE (RE_Stream_Element_Array_Input);
7600 elsif Nam = TSS_Stream_Output
7601 and then Is_Available (RE_Stream_Element_Array_Output)
7603 return RTE (RE_Stream_Element_Array_Output);
7605 elsif Nam = TSS_Stream_Read
7606 and then Is_Available (RE_Stream_Element_Array_Read)
7608 return RTE (RE_Stream_Element_Array_Read);
7610 elsif Nam = TSS_Stream_Write
7611 and then Is_Available (RE_Stream_Element_Array_Write)
7613 return RTE (RE_Stream_Element_Array_Write);
7615 elsif Nam /= TSS_Stream_Input and then
7616 Nam /= TSS_Stream_Output and then
7617 Nam /= TSS_Stream_Read and then
7618 Nam /= TSS_Stream_Write
7620 raise Program_Error;
7623 -- Restriction No_Stream_Optimizations is not set, so we can go
7624 -- ahead and optimize using the block IO forms of the routines.
7627 if Nam = TSS_Stream_Input
7628 and then Is_Available (RE_Stream_Element_Array_Input_Blk_IO)
7630 return RTE (RE_Stream_Element_Array_Input_Blk_IO);
7632 elsif Nam = TSS_Stream_Output
7633 and then Is_Available (RE_Stream_Element_Array_Output_Blk_IO)
7635 return RTE (RE_Stream_Element_Array_Output_Blk_IO);
7637 elsif Nam = TSS_Stream_Read
7638 and then Is_Available (RE_Stream_Element_Array_Read_Blk_IO)
7640 return RTE (RE_Stream_Element_Array_Read_Blk_IO);
7642 elsif Nam = TSS_Stream_Write
7643 and then Is_Available (RE_Stream_Element_Array_Write_Blk_IO)
7645 return RTE (RE_Stream_Element_Array_Write_Blk_IO);
7647 elsif Nam /= TSS_Stream_Input and then
7648 Nam /= TSS_Stream_Output and then
7649 Nam /= TSS_Stream_Read and then
7650 Nam /= TSS_Stream_Write
7652 raise Program_Error;
7656 -- String as defined in package Ada
7658 elsif Base_Typ = Standard_String then
7660 -- Case of No_Stream_Optimizations restriction active
7662 if Restriction_Active (No_Stream_Optimizations) then
7663 if Nam = TSS_Stream_Input
7664 and then Is_Available (RE_String_Input)
7666 return RTE (RE_String_Input);
7668 elsif Nam = TSS_Stream_Output
7669 and then Is_Available (RE_String_Output)
7671 return RTE (RE_String_Output);
7673 elsif Nam = TSS_Stream_Read
7674 and then Is_Available (RE_String_Read)
7676 return RTE (RE_String_Read);
7678 elsif Nam = TSS_Stream_Write
7679 and then Is_Available (RE_String_Write)
7681 return RTE (RE_String_Write);
7683 elsif Nam /= TSS_Stream_Input and then
7684 Nam /= TSS_Stream_Output and then
7685 Nam /= TSS_Stream_Read and then
7686 Nam /= TSS_Stream_Write
7688 raise Program_Error;
7691 -- Restriction No_Stream_Optimizations is not set, so we can go
7692 -- ahead and optimize using the block IO forms of the routines.
7695 if Nam = TSS_Stream_Input
7696 and then Is_Available (RE_String_Input_Blk_IO)
7698 return RTE (RE_String_Input_Blk_IO);
7700 elsif Nam = TSS_Stream_Output
7701 and then Is_Available (RE_String_Output_Blk_IO)
7703 return RTE (RE_String_Output_Blk_IO);
7705 elsif Nam = TSS_Stream_Read
7706 and then Is_Available (RE_String_Read_Blk_IO)
7708 return RTE (RE_String_Read_Blk_IO);
7710 elsif Nam = TSS_Stream_Write
7711 and then Is_Available (RE_String_Write_Blk_IO)
7713 return RTE (RE_String_Write_Blk_IO);
7715 elsif Nam /= TSS_Stream_Input and then
7716 Nam /= TSS_Stream_Output and then
7717 Nam /= TSS_Stream_Read and then
7718 Nam /= TSS_Stream_Write
7720 raise Program_Error;
7724 -- Wide_String as defined in package Ada
7726 elsif Base_Typ = Standard_Wide_String then
7728 -- Case of No_Stream_Optimizations restriction active
7730 if Restriction_Active (No_Stream_Optimizations) then
7731 if Nam = TSS_Stream_Input
7732 and then Is_Available (RE_Wide_String_Input)
7734 return RTE (RE_Wide_String_Input);
7736 elsif Nam = TSS_Stream_Output
7737 and then Is_Available (RE_Wide_String_Output)
7739 return RTE (RE_Wide_String_Output);
7741 elsif Nam = TSS_Stream_Read
7742 and then Is_Available (RE_Wide_String_Read)
7744 return RTE (RE_Wide_String_Read);
7746 elsif Nam = TSS_Stream_Write
7747 and then Is_Available (RE_Wide_String_Write)
7749 return RTE (RE_Wide_String_Write);
7751 elsif Nam /= TSS_Stream_Input and then
7752 Nam /= TSS_Stream_Output and then
7753 Nam /= TSS_Stream_Read and then
7754 Nam /= TSS_Stream_Write
7756 raise Program_Error;
7759 -- Restriction No_Stream_Optimizations is not set, so we can go
7760 -- ahead and optimize using the block IO forms of the routines.
7763 if Nam = TSS_Stream_Input
7764 and then Is_Available (RE_Wide_String_Input_Blk_IO)
7766 return RTE (RE_Wide_String_Input_Blk_IO);
7768 elsif Nam = TSS_Stream_Output
7769 and then Is_Available (RE_Wide_String_Output_Blk_IO)
7771 return RTE (RE_Wide_String_Output_Blk_IO);
7773 elsif Nam = TSS_Stream_Read
7774 and then Is_Available (RE_Wide_String_Read_Blk_IO)
7776 return RTE (RE_Wide_String_Read_Blk_IO);
7778 elsif Nam = TSS_Stream_Write
7779 and then Is_Available (RE_Wide_String_Write_Blk_IO)
7781 return RTE (RE_Wide_String_Write_Blk_IO);
7783 elsif Nam /= TSS_Stream_Input and then
7784 Nam /= TSS_Stream_Output and then
7785 Nam /= TSS_Stream_Read and then
7786 Nam /= TSS_Stream_Write
7788 raise Program_Error;
7792 -- Wide_Wide_String as defined in package Ada
7794 elsif Base_Typ = Standard_Wide_Wide_String then
7796 -- Case of No_Stream_Optimizations restriction active
7798 if Restriction_Active (No_Stream_Optimizations) then
7799 if Nam = TSS_Stream_Input
7800 and then Is_Available (RE_Wide_Wide_String_Input)
7802 return RTE (RE_Wide_Wide_String_Input);
7804 elsif Nam = TSS_Stream_Output
7805 and then Is_Available (RE_Wide_Wide_String_Output)
7807 return RTE (RE_Wide_Wide_String_Output);
7809 elsif Nam = TSS_Stream_Read
7810 and then Is_Available (RE_Wide_Wide_String_Read)
7812 return RTE (RE_Wide_Wide_String_Read);
7814 elsif Nam = TSS_Stream_Write
7815 and then Is_Available (RE_Wide_Wide_String_Write)
7817 return RTE (RE_Wide_Wide_String_Write);
7819 elsif Nam /= TSS_Stream_Input and then
7820 Nam /= TSS_Stream_Output and then
7821 Nam /= TSS_Stream_Read and then
7822 Nam /= TSS_Stream_Write
7824 raise Program_Error;
7827 -- Restriction No_Stream_Optimizations is not set, so we can go
7828 -- ahead and optimize using the block IO forms of the routines.
7831 if Nam = TSS_Stream_Input
7832 and then Is_Available (RE_Wide_Wide_String_Input_Blk_IO)
7834 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
7836 elsif Nam = TSS_Stream_Output
7837 and then Is_Available (RE_Wide_Wide_String_Output_Blk_IO)
7839 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
7841 elsif Nam = TSS_Stream_Read
7842 and then Is_Available (RE_Wide_Wide_String_Read_Blk_IO)
7844 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
7846 elsif Nam = TSS_Stream_Write
7847 and then Is_Available (RE_Wide_Wide_String_Write_Blk_IO)
7849 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
7851 elsif Nam /= TSS_Stream_Input and then
7852 Nam /= TSS_Stream_Output and then
7853 Nam /= TSS_Stream_Read and then
7854 Nam /= TSS_Stream_Write
7856 raise Program_Error;
7862 if Is_Tagged_Type (Typ) and then Is_Derived_Type (Typ) then
7863 return Find_Prim_Op (Typ, Nam);
7865 return Find_Inherited_TSS (Typ, Nam);
7867 end Find_Stream_Subprogram;
7873 function Full_Base (T : Entity_Id) return Entity_Id is
7877 BT := Base_Type (T);
7879 if Is_Private_Type (BT)
7880 and then Present (Full_View (BT))
7882 BT := Full_View (BT);
7888 -----------------------
7889 -- Get_Index_Subtype --
7890 -----------------------
7892 function Get_Index_Subtype (N : Node_Id) return Node_Id is
7893 P_Type : Entity_Id := Etype (Prefix (N));
7898 if Is_Access_Type (P_Type) then
7899 P_Type := Designated_Type (P_Type);
7902 if No (Expressions (N)) then
7905 J := UI_To_Int (Expr_Value (First (Expressions (N))));
7908 Indx := First_Index (P_Type);
7914 return Etype (Indx);
7915 end Get_Index_Subtype;
7917 -------------------------------
7918 -- Get_Stream_Convert_Pragma --
7919 -------------------------------
7921 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
7926 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
7927 -- that a stream convert pragma for a tagged type is not inherited from
7928 -- its parent. Probably what is wrong here is that it is basically
7929 -- incorrect to consider a stream convert pragma to be a representation
7930 -- pragma at all ???
7932 N := First_Rep_Item (Implementation_Base_Type (T));
7933 while Present (N) loop
7934 if Nkind (N) = N_Pragma
7935 and then Pragma_Name (N) = Name_Stream_Convert
7937 -- For tagged types this pragma is not inherited, so we
7938 -- must verify that it is defined for the given type and
7942 Entity (Expression (First (Pragma_Argument_Associations (N))));
7944 if not Is_Tagged_Type (T)
7946 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
7956 end Get_Stream_Convert_Pragma;
7958 ---------------------------------
7959 -- Is_Constrained_Packed_Array --
7960 ---------------------------------
7962 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
7963 Arr : Entity_Id := Typ;
7966 if Is_Access_Type (Arr) then
7967 Arr := Designated_Type (Arr);
7970 return Is_Array_Type (Arr)
7971 and then Is_Constrained (Arr)
7972 and then Present (Packed_Array_Impl_Type (Arr));
7973 end Is_Constrained_Packed_Array;
7975 ----------------------------------------
7976 -- Is_Inline_Floating_Point_Attribute --
7977 ----------------------------------------
7979 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
7980 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
7982 function Is_GCC_Target return Boolean;
7983 -- Return True if we are using a GCC target/back-end
7984 -- ??? Note: the implementation is kludgy/fragile
7990 function Is_GCC_Target return Boolean is
7992 return not CodePeer_Mode and then not AAMP_On_Target;
7995 -- Start of processing for Exp_Attr
7998 -- Machine and Model can be expanded by the GCC backend only
8000 if Id = Attribute_Machine or else Id = Attribute_Model then
8001 return Is_GCC_Target;
8003 -- Remaining cases handled by all back ends are Rounding and Truncation
8004 -- when appearing as the operand of a conversion to some integer type.
8006 elsif Nkind (Parent (N)) /= N_Type_Conversion
8007 or else not Is_Integer_Type (Etype (Parent (N)))
8012 -- Here we are in the integer conversion context
8014 -- Very probably we should also recognize the cases of Machine_Rounding
8015 -- and unbiased rounding in this conversion context, but the back end is
8016 -- not yet prepared to handle these cases ???
8018 return Id = Attribute_Rounding or else Id = Attribute_Truncation;
8019 end Is_Inline_Floating_Point_Attribute;