1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
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 Exp_VFpt; use Exp_VFpt;
43 with Fname; use Fname;
44 with Freeze; use Freeze;
45 with Gnatvsn; use Gnatvsn;
46 with Itypes; use Itypes;
48 with Namet; use Namet;
49 with Nmake; use Nmake;
50 with Nlists; use Nlists;
52 with Restrict; use Restrict;
53 with Rident; use Rident;
54 with Rtsfind; use Rtsfind;
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 procedure Compile_Stream_Body_In_Scope
84 -- The body for a stream subprogram may be generated outside of the scope
85 -- of the type. If the type is fully private, it may depend on the full
86 -- view of other types (e.g. indices) that are currently private as well.
87 -- We install the declarations of the package in which the type is declared
88 -- before compiling the body in what is its proper environment. The Check
89 -- parameter indicates if checks are to be suppressed for the stream body.
90 -- We suppress checks for array/record reads, since the rule is that these
91 -- are like assignments, out of range values due to uninitialized storage,
92 -- or other invalid values do NOT cause a Constraint_Error to be raised.
94 procedure Expand_Access_To_Protected_Op
99 -- An attribute reference to a protected subprogram is transformed into
100 -- a pair of pointers: one to the object, and one to the operations.
101 -- This expansion is performed for 'Access and for 'Unrestricted_Access.
103 procedure Expand_Fpt_Attribute
108 -- This procedure expands a call to a floating-point attribute function.
109 -- N is the attribute reference node, and Args is a list of arguments to
110 -- be passed to the function call. Pkg identifies the package containing
111 -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args
112 -- have already been converted to the floating-point type for which Pkg was
113 -- instantiated. The Nam argument is the relevant attribute processing
114 -- routine to be called. This is the same as the attribute name, except in
115 -- the Unaligned_Valid case.
117 procedure Expand_Fpt_Attribute_R (N : Node_Id);
118 -- This procedure expands a call to a floating-point attribute function
119 -- that takes a single floating-point argument. The function to be called
120 -- is always the same as the attribute name.
122 procedure Expand_Fpt_Attribute_RI (N : Node_Id);
123 -- This procedure expands a call to a floating-point attribute function
124 -- that takes one floating-point argument and one integer argument. The
125 -- function to be called is always the same as the attribute name.
127 procedure Expand_Fpt_Attribute_RR (N : Node_Id);
128 -- This procedure expands a call to a floating-point attribute function
129 -- that takes two floating-point arguments. The function to be called
130 -- is always the same as the attribute name.
132 procedure Expand_Pred_Succ (N : Node_Id);
133 -- Handles expansion of Pred or Succ attributes for case of non-real
134 -- operand with overflow checking required.
136 function Get_Index_Subtype (N : Node_Id) return Entity_Id;
137 -- Used for Last, Last, and Length, when the prefix is an array type.
138 -- Obtains the corresponding index subtype.
140 procedure Find_Fat_Info
142 Fat_Type : out Entity_Id;
143 Fat_Pkg : out RE_Id);
144 -- Given a floating-point type T, identifies the package containing the
145 -- attributes for this type (returned in Fat_Pkg), and the corresponding
146 -- type for which this package was instantiated from Fat_Gen. Error if T
147 -- is not a floating-point type.
149 function Find_Stream_Subprogram
151 Nam : TSS_Name_Type) return Entity_Id;
152 -- Returns the stream-oriented subprogram attribute for Typ. For tagged
153 -- types, the corresponding primitive operation is looked up, else the
154 -- appropriate TSS from the type itself, or from its closest ancestor
155 -- defining it, is returned. In both cases, inheritance of representation
156 -- aspects is thus taken into account.
158 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
159 -- Given a type, find a corresponding stream convert pragma that applies to
160 -- the implementation base type of this type (Typ). If found, return the
161 -- pragma node, otherwise return Empty if no pragma is found.
163 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
164 -- Utility for array attributes, returns true on packed constrained
165 -- arrays, and on access to same.
167 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
168 -- Returns true iff the given node refers to an attribute call that
169 -- can be expanded directly by the back end and does not need front end
170 -- expansion. Typically used for rounding and truncation attributes that
171 -- appear directly inside a conversion to integer.
173 ----------------------------------
174 -- Compile_Stream_Body_In_Scope --
175 ----------------------------------
177 procedure Compile_Stream_Body_In_Scope
183 Installed : Boolean := False;
184 Scop : constant Entity_Id := Scope (Arr);
185 Curr : constant Entity_Id := Current_Scope;
189 and then not In_Open_Scopes (Scop)
190 and then Ekind (Scop) = E_Package
193 Install_Visible_Declarations (Scop);
194 Install_Private_Declarations (Scop);
197 -- The entities in the package are now visible, but the generated
198 -- stream entity must appear in the current scope (usually an
199 -- enclosing stream function) so that itypes all have their proper
206 Insert_Action (N, Decl);
208 Insert_Action (N, Decl, Suppress => All_Checks);
213 -- Remove extra copy of current scope, and package itself
216 End_Package_Scope (Scop);
218 end Compile_Stream_Body_In_Scope;
220 -----------------------------------
221 -- Expand_Access_To_Protected_Op --
222 -----------------------------------
224 procedure Expand_Access_To_Protected_Op
229 -- The value of the attribute_reference is a record containing two
230 -- fields: an access to the protected object, and an access to the
231 -- subprogram itself. The prefix is a selected component.
233 Loc : constant Source_Ptr := Sloc (N);
235 Btyp : constant Entity_Id := Base_Type (Typ);
237 E_T : constant Entity_Id := Equivalent_Type (Btyp);
238 Acc : constant Entity_Id :=
239 Etype (Next_Component (First_Component (E_T)));
243 function May_Be_External_Call return Boolean;
244 -- If the 'Access is to a local operation, but appears in a context
245 -- where it may lead to a call from outside the object, we must treat
246 -- this as an external call. Clearly we cannot tell without full
247 -- flow analysis, and a subsequent call that uses this 'Access may
248 -- lead to a bounded error (trying to seize locks twice, e.g.). For
249 -- now we treat 'Access as a potential external call if it is an actual
250 -- in a call to an outside subprogram.
252 --------------------------
253 -- May_Be_External_Call --
254 --------------------------
256 function May_Be_External_Call return Boolean is
258 Par : Node_Id := Parent (N);
261 -- Account for the case where the Access attribute is part of a
262 -- named parameter association.
264 if Nkind (Par) = N_Parameter_Association then
268 if Nkind_In (Par, N_Procedure_Call_Statement, N_Function_Call)
269 and then Is_Entity_Name (Name (Par))
271 Subp := Entity (Name (Par));
272 return not In_Open_Scopes (Scope (Subp));
276 end May_Be_External_Call;
278 -- Start of processing for Expand_Access_To_Protected_Op
281 -- Within the body of the protected type, the prefix
282 -- designates a local operation, and the object is the first
283 -- parameter of the corresponding protected body of the
284 -- current enclosing operation.
286 if Is_Entity_Name (Pref) then
287 if May_Be_External_Call then
290 (External_Subprogram (Entity (Pref)), Loc);
294 (Protected_Body_Subprogram (Entity (Pref)), Loc);
297 -- Don't traverse the scopes when the attribute occurs within an init
298 -- proc, because we directly use the _init formal of the init proc in
301 Curr := Current_Scope;
302 if not Is_Init_Proc (Curr) then
303 pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
305 while Scope (Curr) /= Scope (Entity (Pref)) loop
306 Curr := Scope (Curr);
310 -- In case of protected entries the first formal of its Protected_
311 -- Body_Subprogram is the address of the object.
313 if Ekind (Curr) = E_Entry then
317 (Protected_Body_Subprogram (Curr)), Loc);
319 -- If the current scope is an init proc, then use the address of the
320 -- _init formal as the object reference.
322 elsif Is_Init_Proc (Curr) then
324 Make_Attribute_Reference (Loc,
325 Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
326 Attribute_Name => Name_Address);
328 -- In case of protected subprograms the first formal of its
329 -- Protected_Body_Subprogram is the object and we get its address.
333 Make_Attribute_Reference (Loc,
337 (Protected_Body_Subprogram (Curr)), Loc),
338 Attribute_Name => Name_Address);
341 -- Case where the prefix is not an entity name. Find the
342 -- version of the protected operation to be called from
343 -- outside the protected object.
349 (Entity (Selector_Name (Pref))), Loc);
352 Make_Attribute_Reference (Loc,
353 Prefix => Relocate_Node (Prefix (Pref)),
354 Attribute_Name => Name_Address);
362 Unchecked_Convert_To (Acc,
363 Make_Attribute_Reference (Loc,
365 Attribute_Name => Name_Address))));
369 Analyze_And_Resolve (N, E_T);
371 -- For subsequent analysis, the node must retain its type.
372 -- The backend will replace it with the equivalent type where
376 end Expand_Access_To_Protected_Op;
378 --------------------------
379 -- Expand_Fpt_Attribute --
380 --------------------------
382 procedure Expand_Fpt_Attribute
388 Loc : constant Source_Ptr := Sloc (N);
389 Typ : constant Entity_Id := Etype (N);
393 -- The function name is the selected component Attr_xxx.yyy where
394 -- Attr_xxx is the package name, and yyy is the argument Nam.
396 -- Note: it would be more usual to have separate RE entries for each
397 -- of the entities in the Fat packages, but first they have identical
398 -- names (so we would have to have lots of renaming declarations to
399 -- meet the normal RE rule of separate names for all runtime entities),
400 -- and second there would be an awful lot of them!
403 Make_Selected_Component (Loc,
404 Prefix => New_Reference_To (RTE (Pkg), Loc),
405 Selector_Name => Make_Identifier (Loc, Nam));
407 -- The generated call is given the provided set of parameters, and then
408 -- wrapped in a conversion which converts the result to the target type
409 -- We use the base type as the target because a range check may be
413 Unchecked_Convert_To (Base_Type (Etype (N)),
414 Make_Function_Call (Loc,
416 Parameter_Associations => Args)));
418 Analyze_And_Resolve (N, Typ);
419 end Expand_Fpt_Attribute;
421 ----------------------------
422 -- Expand_Fpt_Attribute_R --
423 ----------------------------
425 -- The single argument is converted to its root type to call the
426 -- appropriate runtime function, with the actual call being built
427 -- by Expand_Fpt_Attribute
429 procedure Expand_Fpt_Attribute_R (N : Node_Id) is
430 E1 : constant Node_Id := First (Expressions (N));
434 Find_Fat_Info (Etype (E1), Ftp, Pkg);
436 (N, Pkg, Attribute_Name (N),
437 New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
438 end Expand_Fpt_Attribute_R;
440 -----------------------------
441 -- Expand_Fpt_Attribute_RI --
442 -----------------------------
444 -- The first argument is converted to its root type and the second
445 -- argument is converted to standard long long integer to call the
446 -- appropriate runtime function, with the actual call being built
447 -- by Expand_Fpt_Attribute
449 procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
450 E1 : constant Node_Id := First (Expressions (N));
453 E2 : constant Node_Id := Next (E1);
455 Find_Fat_Info (Etype (E1), Ftp, Pkg);
457 (N, Pkg, Attribute_Name (N),
459 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
460 Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
461 end Expand_Fpt_Attribute_RI;
463 -----------------------------
464 -- Expand_Fpt_Attribute_RR --
465 -----------------------------
467 -- The two arguments are converted to their root types to call the
468 -- appropriate runtime function, with the actual call being built
469 -- by Expand_Fpt_Attribute
471 procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
472 E1 : constant Node_Id := First (Expressions (N));
475 E2 : constant Node_Id := Next (E1);
477 Find_Fat_Info (Etype (E1), Ftp, Pkg);
479 (N, Pkg, Attribute_Name (N),
481 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
482 Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
483 end Expand_Fpt_Attribute_RR;
485 ----------------------------------
486 -- Expand_N_Attribute_Reference --
487 ----------------------------------
489 procedure Expand_N_Attribute_Reference (N : Node_Id) is
490 Loc : constant Source_Ptr := Sloc (N);
491 Typ : constant Entity_Id := Etype (N);
492 Btyp : constant Entity_Id := Base_Type (Typ);
493 Pref : constant Node_Id := Prefix (N);
494 Ptyp : constant Entity_Id := Etype (Pref);
495 Exprs : constant List_Id := Expressions (N);
496 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
498 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
499 -- Rewrites a stream attribute for Read, Write or Output with the
500 -- procedure call. Pname is the entity for the procedure to call.
502 ------------------------------
503 -- Rewrite_Stream_Proc_Call --
504 ------------------------------
506 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
507 Item : constant Node_Id := Next (First (Exprs));
508 Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
509 Formal_Typ : constant Entity_Id := Etype (Formal);
510 Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
513 -- The expansion depends on Item, the second actual, which is
514 -- the object being streamed in or out.
516 -- If the item is a component of a packed array type, and
517 -- a conversion is needed on exit, we introduce a temporary to
518 -- hold the value, because otherwise the packed reference will
519 -- not be properly expanded.
521 if Nkind (Item) = N_Indexed_Component
522 and then Is_Packed (Base_Type (Etype (Prefix (Item))))
523 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
527 Temp : constant Entity_Id :=
528 Make_Defining_Identifier
529 (Loc, New_Internal_Name ('V'));
535 Make_Object_Declaration (Loc,
536 Defining_Identifier => Temp,
538 New_Occurrence_Of (Formal_Typ, Loc));
539 Set_Etype (Temp, Formal_Typ);
542 Make_Assignment_Statement (Loc,
543 Name => New_Copy_Tree (Item),
546 (Etype (Item), New_Occurrence_Of (Temp, Loc)));
548 Rewrite (Item, New_Occurrence_Of (Temp, Loc));
552 Make_Procedure_Call_Statement (Loc,
553 Name => New_Occurrence_Of (Pname, Loc),
554 Parameter_Associations => Exprs),
557 Rewrite (N, Make_Null_Statement (Loc));
562 -- For the class-wide dispatching cases, and for cases in which
563 -- the base type of the second argument matches the base type of
564 -- the corresponding formal parameter (that is to say the stream
565 -- operation is not inherited), we are all set, and can use the
566 -- argument unchanged.
568 -- For all other cases we do an unchecked conversion of the second
569 -- parameter to the type of the formal of the procedure we are
570 -- calling. This deals with the private type cases, and with going
571 -- to the root type as required in elementary type case.
573 if not Is_Class_Wide_Type (Entity (Pref))
574 and then not Is_Class_Wide_Type (Etype (Item))
575 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
578 Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
580 -- For untagged derived types set Assignment_OK, to prevent
581 -- copies from being created when the unchecked conversion
582 -- is expanded (which would happen in Remove_Side_Effects
583 -- if Expand_N_Unchecked_Conversion were allowed to call
584 -- Force_Evaluation). The copy could violate Ada semantics
585 -- in cases such as an actual that is an out parameter.
586 -- Note that this approach is also used in exp_ch7 for calls
587 -- to controlled type operations to prevent problems with
588 -- actuals wrapped in unchecked conversions.
590 if Is_Untagged_Derivation (Etype (Expression (Item))) then
591 Set_Assignment_OK (Item);
595 -- And now rewrite the call
598 Make_Procedure_Call_Statement (Loc,
599 Name => New_Occurrence_Of (Pname, Loc),
600 Parameter_Associations => Exprs));
603 end Rewrite_Stream_Proc_Call;
605 -- Start of processing for Expand_N_Attribute_Reference
608 -- Do required validity checking, if enabled. Do not apply check to
609 -- output parameters of an Asm instruction, since the value of this
610 -- is not set till after the attribute has been elaborated.
612 if Validity_Checks_On and then Validity_Check_Operands
613 and then Id /= Attribute_Asm_Output
618 Expr := First (Expressions (N));
619 while Present (Expr) loop
626 -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in-
627 -- place function, then a temporary return object needs to be created
628 -- and access to it must be passed to the function. Currently we limit
629 -- such functions to those with inherently limited result subtypes, but
630 -- eventually we plan to expand the functions that are treated as
631 -- build-in-place to include other composite result types.
633 if Ada_Version >= Ada_05
634 and then Is_Build_In_Place_Function_Call (Pref)
636 Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
639 -- If prefix is a protected type name, this is a reference to
640 -- the current instance of the type.
642 if Is_Protected_Self_Reference (Pref) then
643 Rewrite (Pref, Concurrent_Ref (Pref));
647 -- Remaining processing depends on specific attribute
655 when Attribute_Access |
656 Attribute_Unchecked_Access |
657 Attribute_Unrestricted_Access =>
659 Access_Cases : declare
660 Btyp_DDT : constant Entity_Id := Directly_Designated_Type (Btyp);
661 Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
663 function Enclosing_Object (N : Node_Id) return Node_Id;
664 -- If N denotes a compound name (selected component, indexed
665 -- component, or slice), returns the name of the outermost
666 -- such enclosing object. Otherwise returns N. If the object
667 -- is a renaming, then the renamed object is returned.
669 ----------------------
670 -- Enclosing_Object --
671 ----------------------
673 function Enclosing_Object (N : Node_Id) return Node_Id is
678 while Nkind_In (Obj_Name, N_Selected_Component,
682 Obj_Name := Prefix (Obj_Name);
685 return Get_Referenced_Object (Obj_Name);
686 end Enclosing_Object;
688 -- Local declarations
690 Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
692 -- Start of processing for Access_Cases
695 -- In order to improve the text of error messages, the designated
696 -- type of access-to-subprogram itypes is set by the semantics as
697 -- the associated subprogram entity (see sem_attr). Now we replace
698 -- such node with the proper E_Subprogram_Type itype.
700 if Id = Attribute_Unrestricted_Access
701 and then Is_Subprogram (Directly_Designated_Type (Typ))
703 -- The following conditions ensure that this special management
704 -- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
705 -- At this stage other cases in which the designated type is
706 -- still a subprogram (instead of an E_Subprogram_Type) are
707 -- wrong because the semantics must have overridden the type of
708 -- the node with the type imposed by the context.
710 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
711 and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
713 Set_Etype (N, RTE (RE_Prim_Ptr));
717 Subp : constant Entity_Id :=
718 Directly_Designated_Type (Typ);
720 Extra : Entity_Id := Empty;
721 New_Formal : Entity_Id;
722 Old_Formal : Entity_Id := First_Formal (Subp);
723 Subp_Typ : Entity_Id;
726 Subp_Typ := Create_Itype (E_Subprogram_Type, N);
727 Set_Etype (Subp_Typ, Etype (Subp));
728 Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
730 if Present (Old_Formal) then
731 New_Formal := New_Copy (Old_Formal);
732 Set_First_Entity (Subp_Typ, New_Formal);
735 Set_Scope (New_Formal, Subp_Typ);
736 Etyp := Etype (New_Formal);
738 -- Handle itypes. There is no need to duplicate
739 -- here the itypes associated with record types
740 -- (i.e the implicit full view of private types).
743 and then Ekind (Base_Type (Etyp)) /= E_Record_Type
745 Extra := New_Copy (Etyp);
746 Set_Parent (Extra, New_Formal);
747 Set_Etype (New_Formal, Extra);
748 Set_Scope (Extra, Subp_Typ);
752 Next_Formal (Old_Formal);
753 exit when No (Old_Formal);
755 Set_Next_Entity (New_Formal,
756 New_Copy (Old_Formal));
757 Next_Entity (New_Formal);
760 Set_Next_Entity (New_Formal, Empty);
761 Set_Last_Entity (Subp_Typ, Extra);
764 -- Now that the explicit formals have been duplicated,
765 -- any extra formals needed by the subprogram must be
768 if Present (Extra) then
769 Set_Extra_Formal (Extra, Empty);
772 Create_Extra_Formals (Subp_Typ);
773 Set_Directly_Designated_Type (Typ, Subp_Typ);
778 if Is_Access_Protected_Subprogram_Type (Btyp) then
779 Expand_Access_To_Protected_Op (N, Pref, Typ);
781 -- If prefix is a type name, this is a reference to the current
782 -- instance of the type, within its initialization procedure.
784 elsif Is_Entity_Name (Pref)
785 and then Is_Type (Entity (Pref))
792 -- If the current instance name denotes a task type, then
793 -- the access attribute is rewritten to be the name of the
794 -- "_task" parameter associated with the task type's task
795 -- procedure. An unchecked conversion is applied to ensure
796 -- a type match in cases of expander-generated calls (e.g.
799 if Is_Task_Type (Entity (Pref)) then
801 First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
802 while Present (Formal) loop
803 exit when Chars (Formal) = Name_uTask;
804 Next_Entity (Formal);
807 pragma Assert (Present (Formal));
810 Unchecked_Convert_To (Typ,
811 New_Occurrence_Of (Formal, Loc)));
814 -- The expression must appear in a default expression,
815 -- (which in the initialization procedure is the
816 -- right-hand side of an assignment), and not in a
817 -- discriminant constraint.
821 while Present (Par) loop
822 exit when Nkind (Par) = N_Assignment_Statement;
824 if Nkind (Par) = N_Component_Declaration then
831 if Present (Par) then
833 Make_Attribute_Reference (Loc,
834 Prefix => Make_Identifier (Loc, Name_uInit),
835 Attribute_Name => Attribute_Name (N)));
837 Analyze_And_Resolve (N, Typ);
842 -- If the prefix of an Access attribute is a dereference of an
843 -- access parameter (or a renaming of such a dereference, or a
844 -- subcomponent of such a dereference) and the context is a
845 -- general access type (but not an anonymous access type), then
846 -- apply an accessibility check to the access parameter. We used
847 -- to rewrite the access parameter as a type conversion, but that
848 -- could only be done if the immediate prefix of the Access
849 -- attribute was the dereference, and didn't handle cases where
850 -- the attribute is applied to a subcomponent of the dereference,
851 -- since there's generally no available, appropriate access type
852 -- to convert to in that case. The attribute is passed as the
853 -- point to insert the check, because the access parameter may
854 -- come from a renaming, possibly in a different scope, and the
855 -- check must be associated with the attribute itself.
857 elsif Id = Attribute_Access
858 and then Nkind (Enc_Object) = N_Explicit_Dereference
859 and then Is_Entity_Name (Prefix (Enc_Object))
860 and then Ekind (Btyp) = E_General_Access_Type
861 and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
862 and then Ekind (Etype (Entity (Prefix (Enc_Object))))
863 = E_Anonymous_Access_Type
864 and then Present (Extra_Accessibility
865 (Entity (Prefix (Enc_Object))))
867 Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
869 -- Ada 2005 (AI-251): If the designated type is an interface we
870 -- add an implicit conversion to force the displacement of the
871 -- pointer to reference the secondary dispatch table.
873 elsif Is_Interface (Btyp_DDT)
874 and then (Comes_From_Source (N)
875 or else Comes_From_Source (Ref_Object)
876 or else (Nkind (Ref_Object) in N_Has_Chars
877 and then Chars (Ref_Object) = Name_uInit))
879 if Nkind (Ref_Object) /= N_Explicit_Dereference then
881 -- No implicit conversion required if types match
883 if Btyp_DDT /= Etype (Ref_Object) then
885 Convert_To (Directly_Designated_Type (Typ),
886 New_Copy_Tree (Prefix (N))));
888 Analyze_And_Resolve (Prefix (N),
889 Directly_Designated_Type (Typ));
892 -- When the object is an explicit dereference, convert the
893 -- dereference's prefix.
897 Obj_DDT : constant Entity_Id :=
899 (Directly_Designated_Type
900 (Etype (Prefix (Ref_Object))));
902 -- No implicit conversion required if designated types
905 if Obj_DDT /= Btyp_DDT
906 and then not (Is_Class_Wide_Type (Obj_DDT)
907 and then Etype (Obj_DDT) = Btyp_DDT)
911 New_Copy_Tree (Prefix (Ref_Object))));
912 Analyze_And_Resolve (N, Typ);
923 -- Transforms 'Adjacent into a call to the floating-point attribute
924 -- function Adjacent in Fat_xxx (where xxx is the root type)
926 when Attribute_Adjacent =>
927 Expand_Fpt_Attribute_RR (N);
933 when Attribute_Address => Address : declare
934 Task_Proc : Entity_Id;
937 -- If the prefix is a task or a task type, the useful address is that
938 -- of the procedure for the task body, i.e. the actual program unit.
939 -- We replace the original entity with that of the procedure.
941 if Is_Entity_Name (Pref)
942 and then Is_Task_Type (Entity (Pref))
944 Task_Proc := Next_Entity (Root_Type (Ptyp));
946 while Present (Task_Proc) loop
947 exit when Ekind (Task_Proc) = E_Procedure
948 and then Etype (First_Formal (Task_Proc)) =
949 Corresponding_Record_Type (Ptyp);
950 Next_Entity (Task_Proc);
953 if Present (Task_Proc) then
954 Set_Entity (Pref, Task_Proc);
955 Set_Etype (Pref, Etype (Task_Proc));
958 -- Similarly, the address of a protected operation is the address
959 -- of the corresponding protected body, regardless of the protected
960 -- object from which it is selected.
962 elsif Nkind (Pref) = N_Selected_Component
963 and then Is_Subprogram (Entity (Selector_Name (Pref)))
964 and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
968 External_Subprogram (Entity (Selector_Name (Pref))), Loc));
970 elsif Nkind (Pref) = N_Explicit_Dereference
971 and then Ekind (Ptyp) = E_Subprogram_Type
972 and then Convention (Ptyp) = Convention_Protected
974 -- The prefix is be a dereference of an access_to_protected_
975 -- subprogram. The desired address is the second component of
976 -- the record that represents the access.
979 Addr : constant Entity_Id := Etype (N);
980 Ptr : constant Node_Id := Prefix (Pref);
981 T : constant Entity_Id :=
982 Equivalent_Type (Base_Type (Etype (Ptr)));
986 Unchecked_Convert_To (Addr,
987 Make_Selected_Component (Loc,
988 Prefix => Unchecked_Convert_To (T, Ptr),
989 Selector_Name => New_Occurrence_Of (
990 Next_Entity (First_Entity (T)), Loc))));
992 Analyze_And_Resolve (N, Addr);
995 -- Ada 2005 (AI-251): Class-wide interface objects are always
996 -- "displaced" to reference the tag associated with the interface
997 -- type. In order to obtain the real address of such objects we
998 -- generate a call to a run-time subprogram that returns the base
999 -- address of the object.
1001 -- This processing is not needed in the VM case, where dispatching
1002 -- issues are taken care of by the virtual machine.
1004 elsif Is_Class_Wide_Type (Ptyp)
1005 and then Is_Interface (Ptyp)
1006 and then VM_Target = No_VM
1007 and then not (Nkind (Pref) in N_Has_Entity
1008 and then Is_Subprogram (Entity (Pref)))
1011 Make_Function_Call (Loc,
1012 Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1013 Parameter_Associations => New_List (
1014 Relocate_Node (N))));
1019 -- Deal with packed array reference, other cases are handled by
1022 if Involves_Packed_Array_Reference (Pref) then
1023 Expand_Packed_Address_Reference (N);
1031 when Attribute_Alignment => Alignment : declare
1035 -- For class-wide types, X'Class'Alignment is transformed into a
1036 -- direct reference to the Alignment of the class type, so that the
1037 -- back end does not have to deal with the X'Class'Alignment
1040 if Is_Entity_Name (Pref)
1041 and then Is_Class_Wide_Type (Entity (Pref))
1043 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
1046 -- For x'Alignment applied to an object of a class wide type,
1047 -- transform X'Alignment into a call to the predefined primitive
1048 -- operation _Alignment applied to X.
1050 elsif Is_Class_Wide_Type (Ptyp) then
1052 -- No need to do anything else compiling under restriction
1053 -- No_Dispatching_Calls. During the semantic analysis we
1054 -- already notified such violation.
1056 if Restriction_Active (No_Dispatching_Calls) then
1061 Make_Function_Call (Loc,
1062 Name => New_Reference_To
1063 (Find_Prim_Op (Ptyp, Name_uAlignment), Loc),
1064 Parameter_Associations => New_List (Pref));
1066 if Typ /= Standard_Integer then
1068 -- The context is a specific integer type with which the
1069 -- original attribute was compatible. The function has a
1070 -- specific type as well, so to preserve the compatibility
1071 -- we must convert explicitly.
1073 New_Node := Convert_To (Typ, New_Node);
1076 Rewrite (N, New_Node);
1077 Analyze_And_Resolve (N, Typ);
1080 -- For all other cases, we just have to deal with the case of
1081 -- the fact that the result can be universal.
1084 Apply_Universal_Integer_Attribute_Checks (N);
1092 when Attribute_AST_Entry => AST_Entry : declare
1097 Entry_Ref : Node_Id;
1098 -- The reference to the entry or entry family
1101 -- The index expression for an entry family reference, or
1102 -- the Empty if Entry_Ref references a simple entry.
1105 if Nkind (Pref) = N_Indexed_Component then
1106 Entry_Ref := Prefix (Pref);
1107 Index := First (Expressions (Pref));
1113 -- Get expression for Task_Id and the entry entity
1115 if Nkind (Entry_Ref) = N_Selected_Component then
1117 Make_Attribute_Reference (Loc,
1118 Attribute_Name => Name_Identity,
1119 Prefix => Prefix (Entry_Ref));
1121 Ttyp := Etype (Prefix (Entry_Ref));
1122 Eent := Entity (Selector_Name (Entry_Ref));
1126 Make_Function_Call (Loc,
1127 Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc));
1129 Eent := Entity (Entry_Ref);
1131 -- We have to find the enclosing task to get the task type
1132 -- There must be one, since we already validated this earlier
1134 Ttyp := Current_Scope;
1135 while not Is_Task_Type (Ttyp) loop
1136 Ttyp := Scope (Ttyp);
1140 -- Now rewrite the attribute with a call to Create_AST_Handler
1143 Make_Function_Call (Loc,
1144 Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc),
1145 Parameter_Associations => New_List (
1147 Entry_Index_Expression (Loc, Eent, Index, Ttyp))));
1149 Analyze_And_Resolve (N, RTE (RE_AST_Handler));
1156 -- We compute this if a component clause was present, otherwise we leave
1157 -- the computation up to the back end, since we don't know what layout
1160 -- Note that the attribute can apply to a naked record component
1161 -- in generated code (i.e. the prefix is an identifier that
1162 -- references the component or discriminant entity).
1164 when Attribute_Bit_Position => Bit_Position :
1169 if Nkind (Pref) = N_Identifier then
1170 CE := Entity (Pref);
1172 CE := Entity (Selector_Name (Pref));
1175 if Known_Static_Component_Bit_Offset (CE) then
1177 Make_Integer_Literal (Loc,
1178 Intval => Component_Bit_Offset (CE)));
1179 Analyze_And_Resolve (N, Typ);
1182 Apply_Universal_Integer_Attribute_Checks (N);
1190 -- A reference to P'Body_Version or P'Version is expanded to
1193 -- pragma Import (C, Vnn, "uuuuT";
1195 -- Get_Version_String (Vnn)
1197 -- where uuuu is the unit name (dots replaced by double underscore)
1198 -- and T is B for the cases of Body_Version, or Version applied to a
1199 -- subprogram acting as its own spec, and S for Version applied to a
1200 -- subprogram spec or package. This sequence of code references the
1201 -- the unsigned constant created in the main program by the binder.
1203 -- A special exception occurs for Standard, where the string
1204 -- returned is a copy of the library string in gnatvsn.ads.
1206 when Attribute_Body_Version | Attribute_Version => Version : declare
1207 E : constant Entity_Id :=
1208 Make_Defining_Identifier (Loc, New_Internal_Name ('V'));
1213 -- If not library unit, get to containing library unit
1215 Pent := Entity (Pref);
1216 while Pent /= Standard_Standard
1217 and then Scope (Pent) /= Standard_Standard
1218 and then not Is_Child_Unit (Pent)
1220 Pent := Scope (Pent);
1223 -- Special case Standard and Standard.ASCII
1225 if Pent = Standard_Standard or else Pent = Standard_ASCII then
1227 Make_String_Literal (Loc,
1228 Strval => Verbose_Library_Version));
1233 -- Build required string constant
1235 Get_Name_String (Get_Unit_Name (Pent));
1238 for J in 1 .. Name_Len - 2 loop
1239 if Name_Buffer (J) = '.' then
1240 Store_String_Chars ("__");
1242 Store_String_Char (Get_Char_Code (Name_Buffer (J)));
1246 -- Case of subprogram acting as its own spec, always use body
1248 if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
1249 and then Nkind (Parent (Declaration_Node (Pent))) =
1251 and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
1253 Store_String_Chars ("B");
1255 -- Case of no body present, always use spec
1257 elsif not Unit_Requires_Body (Pent) then
1258 Store_String_Chars ("S");
1260 -- Otherwise use B for Body_Version, S for spec
1262 elsif Id = Attribute_Body_Version then
1263 Store_String_Chars ("B");
1265 Store_String_Chars ("S");
1269 Lib.Version_Referenced (S);
1271 -- Insert the object declaration
1273 Insert_Actions (N, New_List (
1274 Make_Object_Declaration (Loc,
1275 Defining_Identifier => E,
1276 Object_Definition =>
1277 New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
1279 -- Set entity as imported with correct external name
1281 Set_Is_Imported (E);
1282 Set_Interface_Name (E, Make_String_Literal (Loc, S));
1284 -- Set entity as internal to ensure proper Sprint output of its
1285 -- implicit importation.
1287 Set_Is_Internal (E);
1289 -- And now rewrite original reference
1292 Make_Function_Call (Loc,
1293 Name => New_Reference_To (RTE (RE_Get_Version_String), Loc),
1294 Parameter_Associations => New_List (
1295 New_Occurrence_Of (E, Loc))));
1298 Analyze_And_Resolve (N, RTE (RE_Version_String));
1305 -- Transforms 'Ceiling into a call to the floating-point attribute
1306 -- function Ceiling in Fat_xxx (where xxx is the root type)
1308 when Attribute_Ceiling =>
1309 Expand_Fpt_Attribute_R (N);
1315 -- Transforms 'Callable attribute into a call to the Callable function
1317 when Attribute_Callable => Callable :
1319 -- We have an object of a task interface class-wide type as a prefix
1320 -- to Callable. Generate:
1322 -- callable (Task_Id (Pref._disp_get_task_id));
1324 if Ada_Version >= Ada_05
1325 and then Ekind (Ptyp) = E_Class_Wide_Type
1326 and then Is_Interface (Ptyp)
1327 and then Is_Task_Interface (Ptyp)
1330 Make_Function_Call (Loc,
1332 New_Reference_To (RTE (RE_Callable), Loc),
1333 Parameter_Associations => New_List (
1334 Make_Unchecked_Type_Conversion (Loc,
1336 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
1338 Make_Selected_Component (Loc,
1340 New_Copy_Tree (Pref),
1342 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
1346 Build_Call_With_Task (Pref, RTE (RE_Callable)));
1349 Analyze_And_Resolve (N, Standard_Boolean);
1356 -- Transforms 'Caller attribute into a call to either the
1357 -- Task_Entry_Caller or the Protected_Entry_Caller function.
1359 when Attribute_Caller => Caller : declare
1360 Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
1361 Ent : constant Entity_Id := Entity (Pref);
1362 Conctype : constant Entity_Id := Scope (Ent);
1363 Nest_Depth : Integer := 0;
1370 if Is_Protected_Type (Conctype) then
1371 case Corresponding_Runtime_Package (Conctype) is
1372 when System_Tasking_Protected_Objects_Entries =>
1375 (RTE (RE_Protected_Entry_Caller), Loc);
1377 when System_Tasking_Protected_Objects_Single_Entry =>
1380 (RTE (RE_Protected_Single_Entry_Caller), Loc);
1383 raise Program_Error;
1387 Unchecked_Convert_To (Id_Kind,
1388 Make_Function_Call (Loc,
1390 Parameter_Associations => New_List (
1392 (Find_Protection_Object (Current_Scope), Loc)))));
1397 -- Determine the nesting depth of the E'Caller attribute, that
1398 -- is, how many accept statements are nested within the accept
1399 -- statement for E at the point of E'Caller. The runtime uses
1400 -- this depth to find the specified entry call.
1402 for J in reverse 0 .. Scope_Stack.Last loop
1403 S := Scope_Stack.Table (J).Entity;
1405 -- We should not reach the scope of the entry, as it should
1406 -- already have been checked in Sem_Attr that this attribute
1407 -- reference is within a matching accept statement.
1409 pragma Assert (S /= Conctype);
1414 elsif Is_Entry (S) then
1415 Nest_Depth := Nest_Depth + 1;
1420 Unchecked_Convert_To (Id_Kind,
1421 Make_Function_Call (Loc,
1423 New_Reference_To (RTE (RE_Task_Entry_Caller), Loc),
1424 Parameter_Associations => New_List (
1425 Make_Integer_Literal (Loc,
1426 Intval => Int (Nest_Depth))))));
1429 Analyze_And_Resolve (N, Id_Kind);
1436 -- Transforms 'Compose into a call to the floating-point attribute
1437 -- function Compose in Fat_xxx (where xxx is the root type)
1439 -- Note: we strictly should have special code here to deal with the
1440 -- case of absurdly negative arguments (less than Integer'First)
1441 -- which will return a (signed) zero value, but it hardly seems
1442 -- worth the effort. Absurdly large positive arguments will raise
1443 -- constraint error which is fine.
1445 when Attribute_Compose =>
1446 Expand_Fpt_Attribute_RI (N);
1452 when Attribute_Constrained => Constrained : declare
1453 Formal_Ent : constant Entity_Id := Param_Entity (Pref);
1455 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
1456 -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
1457 -- view of an aliased object whose subtype is constrained.
1459 ---------------------------------
1460 -- Is_Constrained_Aliased_View --
1461 ---------------------------------
1463 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
1467 if Is_Entity_Name (Obj) then
1470 if Present (Renamed_Object (E)) then
1471 return Is_Constrained_Aliased_View (Renamed_Object (E));
1473 return Is_Aliased (E) and then Is_Constrained (Etype (E));
1477 return Is_Aliased_View (Obj)
1479 (Is_Constrained (Etype (Obj))
1480 or else (Nkind (Obj) = N_Explicit_Dereference
1482 not Has_Constrained_Partial_View
1483 (Base_Type (Etype (Obj)))));
1485 end Is_Constrained_Aliased_View;
1487 -- Start of processing for Constrained
1490 -- Reference to a parameter where the value is passed as an extra
1491 -- actual, corresponding to the extra formal referenced by the
1492 -- Extra_Constrained field of the corresponding formal. If this
1493 -- is an entry in-parameter, it is replaced by a constant renaming
1494 -- for which Extra_Constrained is never created.
1496 if Present (Formal_Ent)
1497 and then Ekind (Formal_Ent) /= E_Constant
1498 and then Present (Extra_Constrained (Formal_Ent))
1502 (Extra_Constrained (Formal_Ent), Sloc (N)));
1504 -- For variables with a Extra_Constrained field, we use the
1505 -- corresponding entity.
1507 elsif Nkind (Pref) = N_Identifier
1508 and then Ekind (Entity (Pref)) = E_Variable
1509 and then Present (Extra_Constrained (Entity (Pref)))
1513 (Extra_Constrained (Entity (Pref)), Sloc (N)));
1515 -- For all other entity names, we can tell at compile time
1517 elsif Is_Entity_Name (Pref) then
1519 Ent : constant Entity_Id := Entity (Pref);
1523 -- (RM J.4) obsolescent cases
1525 if Is_Type (Ent) then
1529 if Is_Private_Type (Ent) then
1530 Res := not Has_Discriminants (Ent)
1531 or else Is_Constrained (Ent);
1533 -- It not a private type, must be a generic actual type
1534 -- that corresponded to a private type. We know that this
1535 -- correspondence holds, since otherwise the reference
1536 -- within the generic template would have been illegal.
1539 if Is_Composite_Type (Underlying_Type (Ent)) then
1540 Res := Is_Constrained (Ent);
1546 -- If the prefix is not a variable or is aliased, then
1547 -- definitely true; if it's a formal parameter without an
1548 -- associated extra formal, then treat it as constrained.
1550 -- Ada 2005 (AI-363): An aliased prefix must be known to be
1551 -- constrained in order to set the attribute to True.
1553 elsif not Is_Variable (Pref)
1554 or else Present (Formal_Ent)
1555 or else (Ada_Version < Ada_05
1556 and then Is_Aliased_View (Pref))
1557 or else (Ada_Version >= Ada_05
1558 and then Is_Constrained_Aliased_View (Pref))
1562 -- Variable case, look at type to see if it is constrained.
1563 -- Note that the one case where this is not accurate (the
1564 -- procedure formal case), has been handled above.
1566 -- We use the Underlying_Type here (and below) in case the
1567 -- type is private without discriminants, but the full type
1568 -- has discriminants. This case is illegal, but we generate it
1569 -- internally for passing to the Extra_Constrained parameter.
1572 Res := Is_Constrained (Underlying_Type (Etype (Ent)));
1576 New_Reference_To (Boolean_Literals (Res), Loc));
1579 -- Prefix is not an entity name. These are also cases where we can
1580 -- always tell at compile time by looking at the form and type of the
1581 -- prefix. If an explicit dereference of an object with constrained
1582 -- partial view, this is unconstrained (Ada 2005 AI-363).
1588 not Is_Variable (Pref)
1590 (Nkind (Pref) = N_Explicit_Dereference
1592 not Has_Constrained_Partial_View (Base_Type (Ptyp)))
1593 or else Is_Constrained (Underlying_Type (Ptyp))),
1597 Analyze_And_Resolve (N, Standard_Boolean);
1604 -- Transforms 'Copy_Sign into a call to the floating-point attribute
1605 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
1607 when Attribute_Copy_Sign =>
1608 Expand_Fpt_Attribute_RR (N);
1614 -- Transforms 'Count attribute into a call to the Count function
1616 when Attribute_Count => Count : declare
1618 Conctyp : Entity_Id;
1620 Entry_Id : Entity_Id;
1625 -- If the prefix is a member of an entry family, retrieve both
1626 -- entry name and index. For a simple entry there is no index.
1628 if Nkind (Pref) = N_Indexed_Component then
1629 Entnam := Prefix (Pref);
1630 Index := First (Expressions (Pref));
1636 Entry_Id := Entity (Entnam);
1638 -- Find the concurrent type in which this attribute is referenced
1639 -- (there had better be one).
1641 Conctyp := Current_Scope;
1642 while not Is_Concurrent_Type (Conctyp) loop
1643 Conctyp := Scope (Conctyp);
1648 if Is_Protected_Type (Conctyp) then
1649 case Corresponding_Runtime_Package (Conctyp) is
1650 when System_Tasking_Protected_Objects_Entries =>
1651 Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
1654 Make_Function_Call (Loc,
1656 Parameter_Associations => New_List (
1658 (Find_Protection_Object (Current_Scope), Loc),
1659 Entry_Index_Expression
1660 (Loc, Entry_Id, Index, Scope (Entry_Id))));
1662 when System_Tasking_Protected_Objects_Single_Entry =>
1664 New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
1667 Make_Function_Call (Loc,
1669 Parameter_Associations => New_List (
1671 (Find_Protection_Object (Current_Scope), Loc)));
1674 raise Program_Error;
1681 Make_Function_Call (Loc,
1682 Name => New_Reference_To (RTE (RE_Task_Count), Loc),
1683 Parameter_Associations => New_List (
1684 Entry_Index_Expression (Loc,
1685 Entry_Id, Index, Scope (Entry_Id))));
1688 -- The call returns type Natural but the context is universal integer
1689 -- so any integer type is allowed. The attribute was already resolved
1690 -- so its Etype is the required result type. If the base type of the
1691 -- context type is other than Standard.Integer we put in a conversion
1692 -- to the required type. This can be a normal typed conversion since
1693 -- both input and output types of the conversion are integer types
1695 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
1696 Rewrite (N, Convert_To (Typ, Call));
1701 Analyze_And_Resolve (N, Typ);
1708 -- This processing is shared by Elab_Spec
1710 -- What we do is to insert the following declarations
1713 -- pragma Import (C, enn, "name___elabb/s");
1715 -- and then the Elab_Body/Spec attribute is replaced by a reference
1716 -- to this defining identifier.
1718 when Attribute_Elab_Body |
1719 Attribute_Elab_Spec =>
1722 Ent : constant Entity_Id :=
1723 Make_Defining_Identifier (Loc,
1724 New_Internal_Name ('E'));
1728 procedure Make_Elab_String (Nod : Node_Id);
1729 -- Given Nod, an identifier, or a selected component, put the
1730 -- image into the current string literal, with double underline
1731 -- between components.
1733 ----------------------
1734 -- Make_Elab_String --
1735 ----------------------
1737 procedure Make_Elab_String (Nod : Node_Id) is
1739 if Nkind (Nod) = N_Selected_Component then
1740 Make_Elab_String (Prefix (Nod));
1744 Store_String_Char ('$');
1746 Store_String_Char ('.');
1748 Store_String_Char ('_');
1749 Store_String_Char ('_');
1752 Get_Name_String (Chars (Selector_Name (Nod)));
1755 pragma Assert (Nkind (Nod) = N_Identifier);
1756 Get_Name_String (Chars (Nod));
1759 Store_String_Chars (Name_Buffer (1 .. Name_Len));
1760 end Make_Elab_String;
1762 -- Start of processing for Elab_Body/Elab_Spec
1765 -- First we need to prepare the string literal for the name of
1766 -- the elaboration routine to be referenced.
1769 Make_Elab_String (Pref);
1771 if VM_Target = No_VM then
1772 Store_String_Chars ("___elab");
1773 Lang := Make_Identifier (Loc, Name_C);
1775 Store_String_Chars ("._elab");
1776 Lang := Make_Identifier (Loc, Name_Ada);
1779 if Id = Attribute_Elab_Body then
1780 Store_String_Char ('b');
1782 Store_String_Char ('s');
1787 Insert_Actions (N, New_List (
1788 Make_Subprogram_Declaration (Loc,
1790 Make_Procedure_Specification (Loc,
1791 Defining_Unit_Name => Ent)),
1794 Chars => Name_Import,
1795 Pragma_Argument_Associations => New_List (
1796 Make_Pragma_Argument_Association (Loc,
1797 Expression => Lang),
1799 Make_Pragma_Argument_Association (Loc,
1801 Make_Identifier (Loc, Chars (Ent))),
1803 Make_Pragma_Argument_Association (Loc,
1805 Make_String_Literal (Loc, Str))))));
1807 Set_Entity (N, Ent);
1808 Rewrite (N, New_Occurrence_Of (Ent, Loc));
1815 -- Elaborated is always True for preelaborated units, predefined units,
1816 -- pure units and units which have Elaborate_Body pragmas. These units
1817 -- have no elaboration entity.
1819 -- Note: The Elaborated attribute is never passed to the back end
1821 when Attribute_Elaborated => Elaborated : declare
1822 Ent : constant Entity_Id := Entity (Pref);
1825 if Present (Elaboration_Entity (Ent)) then
1827 New_Occurrence_Of (Elaboration_Entity (Ent), Loc));
1829 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
1837 when Attribute_Enum_Rep => Enum_Rep :
1839 -- X'Enum_Rep (Y) expands to
1843 -- This is simply a direct conversion from the enumeration type to
1844 -- the target integer type, which is treated by the back end as a
1845 -- normal integer conversion, treating the enumeration type as an
1846 -- integer, which is exactly what we want! We set Conversion_OK to
1847 -- make sure that the analyzer does not complain about what otherwise
1848 -- might be an illegal conversion.
1850 if Is_Non_Empty_List (Exprs) then
1852 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
1854 -- X'Enum_Rep where X is an enumeration literal is replaced by
1855 -- the literal value.
1857 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
1859 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
1861 -- If this is a renaming of a literal, recover the representation
1864 elsif Ekind (Entity (Pref)) = E_Constant
1865 and then Present (Renamed_Object (Entity (Pref)))
1867 Ekind (Entity (Renamed_Object (Entity (Pref))))
1868 = E_Enumeration_Literal
1871 Make_Integer_Literal (Loc,
1872 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
1874 -- X'Enum_Rep where X is an object does a direct unchecked conversion
1875 -- of the object value, as described for the type case above.
1879 OK_Convert_To (Typ, Relocate_Node (Pref)));
1883 Analyze_And_Resolve (N, Typ);
1890 when Attribute_Enum_Val => Enum_Val : declare
1892 Btyp : constant Entity_Id := Base_Type (Ptyp);
1895 -- X'Enum_Val (Y) expands to
1897 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
1900 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
1903 Make_Raise_Constraint_Error (Loc,
1907 Make_Function_Call (Loc,
1909 New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
1910 Parameter_Associations => New_List (
1911 Relocate_Node (Duplicate_Subexpr (Expr)),
1912 New_Occurrence_Of (Standard_False, Loc))),
1914 Right_Opnd => Make_Integer_Literal (Loc, -1)),
1915 Reason => CE_Range_Check_Failed));
1918 Analyze_And_Resolve (N, Ptyp);
1925 -- Transforms 'Exponent into a call to the floating-point attribute
1926 -- function Exponent in Fat_xxx (where xxx is the root type)
1928 when Attribute_Exponent =>
1929 Expand_Fpt_Attribute_R (N);
1935 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
1937 when Attribute_External_Tag => External_Tag :
1940 Make_Function_Call (Loc,
1941 Name => New_Reference_To (RTE (RE_External_Tag), Loc),
1942 Parameter_Associations => New_List (
1943 Make_Attribute_Reference (Loc,
1944 Attribute_Name => Name_Tag,
1945 Prefix => Prefix (N)))));
1947 Analyze_And_Resolve (N, Standard_String);
1954 when Attribute_First =>
1956 -- If the prefix type is a constrained packed array type which
1957 -- already has a Packed_Array_Type representation defined, then
1958 -- replace this attribute with a direct reference to 'First of the
1959 -- appropriate index subtype (since otherwise the back end will try
1960 -- to give us the value of 'First for this implementation type).
1962 if Is_Constrained_Packed_Array (Ptyp) then
1964 Make_Attribute_Reference (Loc,
1965 Attribute_Name => Name_First,
1966 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
1967 Analyze_And_Resolve (N, Typ);
1969 elsif Is_Access_Type (Ptyp) then
1970 Apply_Access_Check (N);
1977 -- Compute this if component clause was present, otherwise we leave the
1978 -- computation to be completed in the back-end, since we don't know what
1979 -- layout will be chosen.
1981 when Attribute_First_Bit => First_Bit : declare
1982 CE : constant Entity_Id := Entity (Selector_Name (Pref));
1985 if Known_Static_Component_Bit_Offset (CE) then
1987 Make_Integer_Literal (Loc,
1988 Component_Bit_Offset (CE) mod System_Storage_Unit));
1990 Analyze_And_Resolve (N, Typ);
1993 Apply_Universal_Integer_Attribute_Checks (N);
2003 -- fixtype'Fixed_Value (integer-value)
2007 -- fixtype(integer-value)
2009 -- We do all the required analysis of the conversion here, because we do
2010 -- not want this to go through the fixed-point conversion circuits. Note
2011 -- that the back end always treats fixed-point as equivalent to the
2012 -- corresponding integer type anyway.
2014 when Attribute_Fixed_Value => Fixed_Value :
2017 Make_Type_Conversion (Loc,
2018 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2019 Expression => Relocate_Node (First (Exprs))));
2020 Set_Etype (N, Entity (Pref));
2023 -- Note: it might appear that a properly analyzed unchecked conversion
2024 -- would be just fine here, but that's not the case, since the full
2025 -- range checks performed by the following call are critical!
2027 Apply_Type_Conversion_Checks (N);
2034 -- Transforms 'Floor into a call to the floating-point attribute
2035 -- function Floor in Fat_xxx (where xxx is the root type)
2037 when Attribute_Floor =>
2038 Expand_Fpt_Attribute_R (N);
2044 -- For the fixed-point type Typ:
2050 -- Result_Type (System.Fore (Universal_Real (Type'First)),
2051 -- Universal_Real (Type'Last))
2053 -- Note that we know that the type is a non-static subtype, or Fore
2054 -- would have itself been computed dynamically in Eval_Attribute.
2056 when Attribute_Fore => Fore : begin
2059 Make_Function_Call (Loc,
2060 Name => New_Reference_To (RTE (RE_Fore), Loc),
2062 Parameter_Associations => New_List (
2063 Convert_To (Universal_Real,
2064 Make_Attribute_Reference (Loc,
2065 Prefix => New_Reference_To (Ptyp, Loc),
2066 Attribute_Name => Name_First)),
2068 Convert_To (Universal_Real,
2069 Make_Attribute_Reference (Loc,
2070 Prefix => New_Reference_To (Ptyp, Loc),
2071 Attribute_Name => Name_Last))))));
2073 Analyze_And_Resolve (N, Typ);
2080 -- Transforms 'Fraction into a call to the floating-point attribute
2081 -- function Fraction in Fat_xxx (where xxx is the root type)
2083 when Attribute_Fraction =>
2084 Expand_Fpt_Attribute_R (N);
2090 when Attribute_From_Any => From_Any : declare
2091 P_Type : constant Entity_Id := Etype (Pref);
2092 Decls : constant List_Id := New_List;
2095 Build_From_Any_Call (P_Type,
2096 Relocate_Node (First (Exprs)),
2098 Insert_Actions (N, Decls);
2099 Analyze_And_Resolve (N, P_Type);
2106 -- For an exception returns a reference to the exception data:
2107 -- Exception_Id!(Prefix'Reference)
2109 -- For a task it returns a reference to the _task_id component of
2110 -- corresponding record:
2112 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
2114 -- in Ada.Task_Identification
2116 when Attribute_Identity => Identity : declare
2117 Id_Kind : Entity_Id;
2120 if Ptyp = Standard_Exception_Type then
2121 Id_Kind := RTE (RE_Exception_Id);
2123 if Present (Renamed_Object (Entity (Pref))) then
2124 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
2128 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
2130 Id_Kind := RTE (RO_AT_Task_Id);
2132 -- If the prefix is a task interface, the Task_Id is obtained
2133 -- dynamically through a dispatching call, as for other task
2134 -- attributes applied to interfaces.
2136 if Ada_Version >= Ada_05
2137 and then Ekind (Ptyp) = E_Class_Wide_Type
2138 and then Is_Interface (Ptyp)
2139 and then Is_Task_Interface (Ptyp)
2142 Unchecked_Convert_To (Id_Kind,
2143 Make_Selected_Component (Loc,
2145 New_Copy_Tree (Pref),
2147 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
2151 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
2155 Analyze_And_Resolve (N, Id_Kind);
2162 -- Image attribute is handled in separate unit Exp_Imgv
2164 when Attribute_Image =>
2165 Exp_Imgv.Expand_Image_Attribute (N);
2171 -- X'Img is expanded to typ'Image (X), where typ is the type of X
2173 when Attribute_Img => Img :
2176 Make_Attribute_Reference (Loc,
2177 Prefix => New_Reference_To (Ptyp, Loc),
2178 Attribute_Name => Name_Image,
2179 Expressions => New_List (Relocate_Node (Pref))));
2181 Analyze_And_Resolve (N, Standard_String);
2188 when Attribute_Input => Input : declare
2189 P_Type : constant Entity_Id := Entity (Pref);
2190 B_Type : constant Entity_Id := Base_Type (P_Type);
2191 U_Type : constant Entity_Id := Underlying_Type (P_Type);
2192 Strm : constant Node_Id := First (Exprs);
2200 Cntrl : Node_Id := Empty;
2201 -- Value for controlling argument in call. Always Empty except in
2202 -- the dispatching (class-wide type) case, where it is a reference
2203 -- to the dummy object initialized to the right internal tag.
2205 procedure Freeze_Stream_Subprogram (F : Entity_Id);
2206 -- The expansion of the attribute reference may generate a call to
2207 -- a user-defined stream subprogram that is frozen by the call. This
2208 -- can lead to access-before-elaboration problem if the reference
2209 -- appears in an object declaration and the subprogram body has not
2210 -- been seen. The freezing of the subprogram requires special code
2211 -- because it appears in an expanded context where expressions do
2212 -- not freeze their constituents.
2214 ------------------------------
2215 -- Freeze_Stream_Subprogram --
2216 ------------------------------
2218 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
2219 Decl : constant Node_Id := Unit_Declaration_Node (F);
2223 -- If this is user-defined subprogram, the corresponding
2224 -- stream function appears as a renaming-as-body, and the
2225 -- user subprogram must be retrieved by tree traversal.
2228 and then Nkind (Decl) = N_Subprogram_Declaration
2229 and then Present (Corresponding_Body (Decl))
2231 Bod := Corresponding_Body (Decl);
2233 if Nkind (Unit_Declaration_Node (Bod)) =
2234 N_Subprogram_Renaming_Declaration
2236 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
2239 end Freeze_Stream_Subprogram;
2241 -- Start of processing for Input
2244 -- If no underlying type, we have an error that will be diagnosed
2245 -- elsewhere, so here we just completely ignore the expansion.
2251 -- If there is a TSS for Input, just call it
2253 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
2255 if Present (Fname) then
2259 -- If there is a Stream_Convert pragma, use it, we rewrite
2261 -- sourcetyp'Input (stream)
2265 -- sourcetyp (streamread (strmtyp'Input (stream)));
2267 -- where streamread is the given Read function that converts an
2268 -- argument of type strmtyp to type sourcetyp or a type from which
2269 -- it is derived (extra conversion required for the derived case).
2271 Prag := Get_Stream_Convert_Pragma (P_Type);
2273 if Present (Prag) then
2274 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
2275 Rfunc := Entity (Expression (Arg2));
2279 Make_Function_Call (Loc,
2280 Name => New_Occurrence_Of (Rfunc, Loc),
2281 Parameter_Associations => New_List (
2282 Make_Attribute_Reference (Loc,
2285 (Etype (First_Formal (Rfunc)), Loc),
2286 Attribute_Name => Name_Input,
2287 Expressions => Exprs)))));
2289 Analyze_And_Resolve (N, B_Type);
2294 elsif Is_Elementary_Type (U_Type) then
2296 -- A special case arises if we have a defined _Read routine,
2297 -- since in this case we are required to call this routine.
2299 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
2300 Build_Record_Or_Elementary_Input_Function
2301 (Loc, U_Type, Decl, Fname);
2302 Insert_Action (N, Decl);
2304 -- For normal cases, we call the I_xxx routine directly
2307 Rewrite (N, Build_Elementary_Input_Call (N));
2308 Analyze_And_Resolve (N, P_Type);
2314 elsif Is_Array_Type (U_Type) then
2315 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
2316 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
2318 -- Dispatching case with class-wide type
2320 elsif Is_Class_Wide_Type (P_Type) then
2322 -- No need to do anything else compiling under restriction
2323 -- No_Dispatching_Calls. During the semantic analysis we
2324 -- already notified such violation.
2326 if Restriction_Active (No_Dispatching_Calls) then
2331 Rtyp : constant Entity_Id := Root_Type (P_Type);
2336 -- Read the internal tag (RM 13.13.2(34)) and use it to
2337 -- initialize a dummy tag object:
2339 -- Dnn : Ada.Tags.Tag
2340 -- := Descendant_Tag (String'Input (Strm), P_Type);
2342 -- This dummy object is used only to provide a controlling
2343 -- argument for the eventual _Input call. Descendant_Tag is
2344 -- called rather than Internal_Tag to ensure that we have a
2345 -- tag for a type that is descended from the prefix type and
2346 -- declared at the same accessibility level (the exception
2347 -- Tag_Error will be raised otherwise). The level check is
2348 -- required for Ada 2005 because tagged types can be
2349 -- extended in nested scopes (AI-344).
2352 Make_Defining_Identifier (Loc,
2353 Chars => New_Internal_Name ('D'));
2356 Make_Object_Declaration (Loc,
2357 Defining_Identifier => Dnn,
2358 Object_Definition =>
2359 New_Occurrence_Of (RTE (RE_Tag), Loc),
2361 Make_Function_Call (Loc,
2363 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
2364 Parameter_Associations => New_List (
2365 Make_Attribute_Reference (Loc,
2367 New_Occurrence_Of (Standard_String, Loc),
2368 Attribute_Name => Name_Input,
2369 Expressions => New_List (
2371 (Duplicate_Subexpr (Strm)))),
2372 Make_Attribute_Reference (Loc,
2373 Prefix => New_Reference_To (P_Type, Loc),
2374 Attribute_Name => Name_Tag))));
2376 Insert_Action (N, Decl);
2378 -- Now we need to get the entity for the call, and construct
2379 -- a function call node, where we preset a reference to Dnn
2380 -- as the controlling argument (doing an unchecked convert
2381 -- to the class-wide tagged type to make it look like a real
2384 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
2385 Cntrl := Unchecked_Convert_To (P_Type,
2386 New_Occurrence_Of (Dnn, Loc));
2387 Set_Etype (Cntrl, P_Type);
2388 Set_Parent (Cntrl, N);
2391 -- For tagged types, use the primitive Input function
2393 elsif Is_Tagged_Type (U_Type) then
2394 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
2396 -- All other record type cases, including protected records. The
2397 -- latter only arise for expander generated code for handling
2398 -- shared passive partition access.
2402 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
2404 -- Ada 2005 (AI-216): Program_Error is raised executing default
2405 -- implementation of the Input attribute of an unchecked union
2406 -- type if the type lacks default discriminant values.
2408 if Is_Unchecked_Union (Base_Type (U_Type))
2409 and then No (Discriminant_Constraint (U_Type))
2412 Make_Raise_Program_Error (Loc,
2413 Reason => PE_Unchecked_Union_Restriction));
2418 Build_Record_Or_Elementary_Input_Function
2419 (Loc, Base_Type (U_Type), Decl, Fname);
2420 Insert_Action (N, Decl);
2422 if Nkind (Parent (N)) = N_Object_Declaration
2423 and then Is_Record_Type (U_Type)
2425 -- The stream function may contain calls to user-defined
2426 -- Read procedures for individual components.
2433 Comp := First_Component (U_Type);
2434 while Present (Comp) loop
2436 Find_Stream_Subprogram
2437 (Etype (Comp), TSS_Stream_Read);
2439 if Present (Func) then
2440 Freeze_Stream_Subprogram (Func);
2443 Next_Component (Comp);
2450 -- If we fall through, Fname is the function to be called. The result
2451 -- is obtained by calling the appropriate function, then converting
2452 -- the result. The conversion does a subtype check.
2455 Make_Function_Call (Loc,
2456 Name => New_Occurrence_Of (Fname, Loc),
2457 Parameter_Associations => New_List (
2458 Relocate_Node (Strm)));
2460 Set_Controlling_Argument (Call, Cntrl);
2461 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
2462 Analyze_And_Resolve (N, P_Type);
2464 if Nkind (Parent (N)) = N_Object_Declaration then
2465 Freeze_Stream_Subprogram (Fname);
2475 -- inttype'Fixed_Value (fixed-value)
2479 -- inttype(integer-value))
2481 -- we do all the required analysis of the conversion here, because we do
2482 -- not want this to go through the fixed-point conversion circuits. Note
2483 -- that the back end always treats fixed-point as equivalent to the
2484 -- corresponding integer type anyway.
2486 when Attribute_Integer_Value => Integer_Value :
2489 Make_Type_Conversion (Loc,
2490 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2491 Expression => Relocate_Node (First (Exprs))));
2492 Set_Etype (N, Entity (Pref));
2495 -- Note: it might appear that a properly analyzed unchecked conversion
2496 -- would be just fine here, but that's not the case, since the full
2497 -- range checks performed by the following call are critical!
2499 Apply_Type_Conversion_Checks (N);
2506 when Attribute_Invalid_Value =>
2507 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
2513 when Attribute_Last =>
2515 -- If the prefix type is a constrained packed array type which
2516 -- already has a Packed_Array_Type representation defined, then
2517 -- replace this attribute with a direct reference to 'Last of the
2518 -- appropriate index subtype (since otherwise the back end will try
2519 -- to give us the value of 'Last for this implementation type).
2521 if Is_Constrained_Packed_Array (Ptyp) then
2523 Make_Attribute_Reference (Loc,
2524 Attribute_Name => Name_Last,
2525 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2526 Analyze_And_Resolve (N, Typ);
2528 elsif Is_Access_Type (Ptyp) then
2529 Apply_Access_Check (N);
2536 -- We compute this if a component clause was present, otherwise we leave
2537 -- the computation up to the back end, since we don't know what layout
2540 when Attribute_Last_Bit => Last_Bit : declare
2541 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2544 if Known_Static_Component_Bit_Offset (CE)
2545 and then Known_Static_Esize (CE)
2548 Make_Integer_Literal (Loc,
2549 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
2552 Analyze_And_Resolve (N, Typ);
2555 Apply_Universal_Integer_Attribute_Checks (N);
2563 -- Transforms 'Leading_Part into a call to the floating-point attribute
2564 -- function Leading_Part in Fat_xxx (where xxx is the root type)
2566 -- Note: strictly, we should generate special case code to deal with
2567 -- absurdly large positive arguments (greater than Integer'Last), which
2568 -- result in returning the first argument unchanged, but it hardly seems
2569 -- worth the effort. We raise constraint error for absurdly negative
2570 -- arguments which is fine.
2572 when Attribute_Leading_Part =>
2573 Expand_Fpt_Attribute_RI (N);
2579 when Attribute_Length => declare
2584 -- Processing for packed array types
2586 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
2587 Ityp := Get_Index_Subtype (N);
2589 -- If the index type, Ityp, is an enumeration type with holes,
2590 -- then we calculate X'Length explicitly using
2593 -- (0, Ityp'Pos (X'Last (N)) -
2594 -- Ityp'Pos (X'First (N)) + 1);
2596 -- Since the bounds in the template are the representation values
2597 -- and the back end would get the wrong value.
2599 if Is_Enumeration_Type (Ityp)
2600 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
2605 Xnum := Expr_Value (First (Expressions (N)));
2609 Make_Attribute_Reference (Loc,
2610 Prefix => New_Occurrence_Of (Typ, Loc),
2611 Attribute_Name => Name_Max,
2612 Expressions => New_List
2613 (Make_Integer_Literal (Loc, 0),
2617 Make_Op_Subtract (Loc,
2619 Make_Attribute_Reference (Loc,
2620 Prefix => New_Occurrence_Of (Ityp, Loc),
2621 Attribute_Name => Name_Pos,
2623 Expressions => New_List (
2624 Make_Attribute_Reference (Loc,
2625 Prefix => Duplicate_Subexpr (Pref),
2626 Attribute_Name => Name_Last,
2627 Expressions => New_List (
2628 Make_Integer_Literal (Loc, Xnum))))),
2631 Make_Attribute_Reference (Loc,
2632 Prefix => New_Occurrence_Of (Ityp, Loc),
2633 Attribute_Name => Name_Pos,
2635 Expressions => New_List (
2636 Make_Attribute_Reference (Loc,
2638 Duplicate_Subexpr_No_Checks (Pref),
2639 Attribute_Name => Name_First,
2640 Expressions => New_List (
2641 Make_Integer_Literal (Loc, Xnum)))))),
2643 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
2645 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
2648 -- If the prefix type is a constrained packed array type which
2649 -- already has a Packed_Array_Type representation defined, then
2650 -- replace this attribute with a direct reference to 'Range_Length
2651 -- of the appropriate index subtype (since otherwise the back end
2652 -- will try to give us the value of 'Length for this
2653 -- implementation type).
2655 elsif Is_Constrained (Ptyp) then
2657 Make_Attribute_Reference (Loc,
2658 Attribute_Name => Name_Range_Length,
2659 Prefix => New_Reference_To (Ityp, Loc)));
2660 Analyze_And_Resolve (N, Typ);
2665 elsif Is_Access_Type (Ptyp) then
2666 Apply_Access_Check (N);
2668 -- If the designated type is a packed array type, then we convert
2669 -- the reference to:
2672 -- xtyp'Pos (Pref'Last (Expr)) -
2673 -- xtyp'Pos (Pref'First (Expr)));
2675 -- This is a bit complex, but it is the easiest thing to do that
2676 -- works in all cases including enum types with holes xtyp here
2677 -- is the appropriate index type.
2680 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
2684 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
2685 Xtyp := Get_Index_Subtype (N);
2688 Make_Attribute_Reference (Loc,
2689 Prefix => New_Occurrence_Of (Typ, Loc),
2690 Attribute_Name => Name_Max,
2691 Expressions => New_List (
2692 Make_Integer_Literal (Loc, 0),
2695 Make_Integer_Literal (Loc, 1),
2696 Make_Op_Subtract (Loc,
2698 Make_Attribute_Reference (Loc,
2699 Prefix => New_Occurrence_Of (Xtyp, Loc),
2700 Attribute_Name => Name_Pos,
2701 Expressions => New_List (
2702 Make_Attribute_Reference (Loc,
2703 Prefix => Duplicate_Subexpr (Pref),
2704 Attribute_Name => Name_Last,
2706 New_Copy_List (Exprs)))),
2709 Make_Attribute_Reference (Loc,
2710 Prefix => New_Occurrence_Of (Xtyp, Loc),
2711 Attribute_Name => Name_Pos,
2712 Expressions => New_List (
2713 Make_Attribute_Reference (Loc,
2715 Duplicate_Subexpr_No_Checks (Pref),
2716 Attribute_Name => Name_First,
2718 New_Copy_List (Exprs)))))))));
2720 Analyze_And_Resolve (N, Typ);
2724 -- Otherwise leave it to the back end
2727 Apply_Universal_Integer_Attribute_Checks (N);
2735 -- Transforms 'Machine into a call to the floating-point attribute
2736 -- function Machine in Fat_xxx (where xxx is the root type)
2738 when Attribute_Machine =>
2739 Expand_Fpt_Attribute_R (N);
2741 ----------------------
2742 -- Machine_Rounding --
2743 ----------------------
2745 -- Transforms 'Machine_Rounding into a call to the floating-point
2746 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
2747 -- type). Expansion is avoided for cases the back end can handle
2750 when Attribute_Machine_Rounding =>
2751 if not Is_Inline_Floating_Point_Attribute (N) then
2752 Expand_Fpt_Attribute_R (N);
2759 -- Machine_Size is equivalent to Object_Size, so transform it into
2760 -- Object_Size and that way the back end never sees Machine_Size.
2762 when Attribute_Machine_Size =>
2764 Make_Attribute_Reference (Loc,
2765 Prefix => Prefix (N),
2766 Attribute_Name => Name_Object_Size));
2768 Analyze_And_Resolve (N, Typ);
2774 -- The only case that can get this far is the dynamic case of the old
2775 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
2782 -- ityp (System.Mantissa.Mantissa_Value
2783 -- (Integer'Integer_Value (typ'First),
2784 -- Integer'Integer_Value (typ'Last)));
2786 when Attribute_Mantissa => Mantissa : begin
2789 Make_Function_Call (Loc,
2790 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
2792 Parameter_Associations => New_List (
2794 Make_Attribute_Reference (Loc,
2795 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2796 Attribute_Name => Name_Integer_Value,
2797 Expressions => New_List (
2799 Make_Attribute_Reference (Loc,
2800 Prefix => New_Occurrence_Of (Ptyp, Loc),
2801 Attribute_Name => Name_First))),
2803 Make_Attribute_Reference (Loc,
2804 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2805 Attribute_Name => Name_Integer_Value,
2806 Expressions => New_List (
2808 Make_Attribute_Reference (Loc,
2809 Prefix => New_Occurrence_Of (Ptyp, Loc),
2810 Attribute_Name => Name_Last)))))));
2812 Analyze_And_Resolve (N, Typ);
2815 --------------------
2816 -- Mechanism_Code --
2817 --------------------
2819 when Attribute_Mechanism_Code =>
2821 -- We must replace the prefix in the renamed case
2823 if Is_Entity_Name (Pref)
2824 and then Present (Alias (Entity (Pref)))
2826 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
2833 when Attribute_Mod => Mod_Case : declare
2834 Arg : constant Node_Id := Relocate_Node (First (Exprs));
2835 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
2836 Modv : constant Uint := Modulus (Btyp);
2840 -- This is not so simple. The issue is what type to use for the
2841 -- computation of the modular value.
2843 -- The easy case is when the modulus value is within the bounds
2844 -- of the signed integer type of the argument. In this case we can
2845 -- just do the computation in that signed integer type, and then
2846 -- do an ordinary conversion to the target type.
2848 if Modv <= Expr_Value (Hi) then
2853 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
2855 -- Here we know that the modulus is larger than type'Last of the
2856 -- integer type. There are two cases to consider:
2858 -- a) The integer value is non-negative. In this case, it is
2859 -- returned as the result (since it is less than the modulus).
2861 -- b) The integer value is negative. In this case, we know that the
2862 -- result is modulus + value, where the value might be as small as
2863 -- -modulus. The trouble is what type do we use to do the subtract.
2864 -- No type will do, since modulus can be as big as 2**64, and no
2865 -- integer type accommodates this value. Let's do bit of algebra
2868 -- = modulus - (-value)
2869 -- = (modulus - 1) - (-value - 1)
2871 -- Now modulus - 1 is certainly in range of the modular type.
2872 -- -value is in the range 1 .. modulus, so -value -1 is in the
2873 -- range 0 .. modulus-1 which is in range of the modular type.
2874 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
2875 -- which we can compute using the integer base type.
2877 -- Once this is done we analyze the conditional expression without
2878 -- range checks, because we know everything is in range, and we
2879 -- want to prevent spurious warnings on either branch.
2883 Make_Conditional_Expression (Loc,
2884 Expressions => New_List (
2886 Left_Opnd => Duplicate_Subexpr (Arg),
2887 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2890 Duplicate_Subexpr_No_Checks (Arg)),
2892 Make_Op_Subtract (Loc,
2894 Make_Integer_Literal (Loc,
2895 Intval => Modv - 1),
2901 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
2903 Make_Integer_Literal (Loc,
2904 Intval => 1))))))));
2908 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
2915 -- Transforms 'Model into a call to the floating-point attribute
2916 -- function Model in Fat_xxx (where xxx is the root type)
2918 when Attribute_Model =>
2919 Expand_Fpt_Attribute_R (N);
2925 -- The processing for Object_Size shares the processing for Size
2931 when Attribute_Old => Old : declare
2932 Tnn : constant Entity_Id :=
2933 Make_Defining_Identifier (Loc,
2934 Chars => New_Internal_Name ('T'));
2939 -- Find the nearest subprogram body, ignoring _Preconditions
2943 Subp := Parent (Subp);
2944 exit when Nkind (Subp) = N_Subprogram_Body
2945 and then Chars (Defining_Entity (Subp)) /= Name_uPostconditions;
2948 -- Insert the assignment at the start of the declarations
2951 Make_Object_Declaration (Loc,
2952 Defining_Identifier => Tnn,
2953 Constant_Present => True,
2954 Object_Definition => New_Occurrence_Of (Etype (N), Loc),
2955 Expression => Pref);
2957 if Is_Empty_List (Declarations (Subp)) then
2958 Set_Declarations (Subp, New_List (Asn_Stm));
2961 Insert_Action (First (Declarations (Subp)), Asn_Stm);
2964 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
2971 when Attribute_Output => Output : declare
2972 P_Type : constant Entity_Id := Entity (Pref);
2973 U_Type : constant Entity_Id := Underlying_Type (P_Type);
2981 -- If no underlying type, we have an error that will be diagnosed
2982 -- elsewhere, so here we just completely ignore the expansion.
2988 -- If TSS for Output is present, just call it
2990 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
2992 if Present (Pname) then
2996 -- If there is a Stream_Convert pragma, use it, we rewrite
2998 -- sourcetyp'Output (stream, Item)
3002 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
3004 -- where strmwrite is the given Write function that converts an
3005 -- argument of type sourcetyp or a type acctyp, from which it is
3006 -- derived to type strmtyp. The conversion to acttyp is required
3007 -- for the derived case.
3009 Prag := Get_Stream_Convert_Pragma (P_Type);
3011 if Present (Prag) then
3013 Next (Next (First (Pragma_Argument_Associations (Prag))));
3014 Wfunc := Entity (Expression (Arg3));
3017 Make_Attribute_Reference (Loc,
3018 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
3019 Attribute_Name => Name_Output,
3020 Expressions => New_List (
3021 Relocate_Node (First (Exprs)),
3022 Make_Function_Call (Loc,
3023 Name => New_Occurrence_Of (Wfunc, Loc),
3024 Parameter_Associations => New_List (
3025 OK_Convert_To (Etype (First_Formal (Wfunc)),
3026 Relocate_Node (Next (First (Exprs)))))))));
3031 -- For elementary types, we call the W_xxx routine directly.
3032 -- Note that the effect of Write and Output is identical for
3033 -- the case of an elementary type, since there are no
3034 -- discriminants or bounds.
3036 elsif Is_Elementary_Type (U_Type) then
3038 -- A special case arises if we have a defined _Write routine,
3039 -- since in this case we are required to call this routine.
3041 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
3042 Build_Record_Or_Elementary_Output_Procedure
3043 (Loc, U_Type, Decl, Pname);
3044 Insert_Action (N, Decl);
3046 -- For normal cases, we call the W_xxx routine directly
3049 Rewrite (N, Build_Elementary_Write_Call (N));
3056 elsif Is_Array_Type (U_Type) then
3057 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
3058 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3060 -- Class-wide case, first output external tag, then dispatch
3061 -- to the appropriate primitive Output function (RM 13.13.2(31)).
3063 elsif Is_Class_Wide_Type (P_Type) then
3065 -- No need to do anything else compiling under restriction
3066 -- No_Dispatching_Calls. During the semantic analysis we
3067 -- already notified such violation.
3069 if Restriction_Active (No_Dispatching_Calls) then
3074 Strm : constant Node_Id := First (Exprs);
3075 Item : constant Node_Id := Next (Strm);
3078 -- Ada 2005 (AI-344): Check that the accessibility level
3079 -- of the type of the output object is not deeper than
3080 -- that of the attribute's prefix type.
3082 -- if Get_Access_Level (Item'Tag)
3083 -- /= Get_Access_Level (P_Type'Tag)
3088 -- String'Output (Strm, External_Tag (Item'Tag));
3090 -- We cannot figure out a practical way to implement this
3091 -- accessibility check on virtual machines, so we omit it.
3093 if Ada_Version >= Ada_05
3094 and then VM_Target = No_VM
3097 Make_Implicit_If_Statement (N,
3101 Build_Get_Access_Level (Loc,
3102 Make_Attribute_Reference (Loc,
3105 Duplicate_Subexpr (Item,
3107 Attribute_Name => Name_Tag)),
3110 Make_Integer_Literal (Loc,
3111 Type_Access_Level (P_Type))),
3114 New_List (Make_Raise_Statement (Loc,
3116 RTE (RE_Tag_Error), Loc)))));
3120 Make_Attribute_Reference (Loc,
3121 Prefix => New_Occurrence_Of (Standard_String, Loc),
3122 Attribute_Name => Name_Output,
3123 Expressions => New_List (
3124 Relocate_Node (Duplicate_Subexpr (Strm)),
3125 Make_Function_Call (Loc,
3127 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3128 Parameter_Associations => New_List (
3129 Make_Attribute_Reference (Loc,
3132 (Duplicate_Subexpr (Item, Name_Req => True)),
3133 Attribute_Name => Name_Tag))))));
3136 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3138 -- Tagged type case, use the primitive Output function
3140 elsif Is_Tagged_Type (U_Type) then
3141 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3143 -- All other record type cases, including protected records.
3144 -- The latter only arise for expander generated code for
3145 -- handling shared passive partition access.
3149 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3151 -- Ada 2005 (AI-216): Program_Error is raised when executing
3152 -- the default implementation of the Output attribute of an
3153 -- unchecked union type if the type lacks default discriminant
3156 if Is_Unchecked_Union (Base_Type (U_Type))
3157 and then No (Discriminant_Constraint (U_Type))
3160 Make_Raise_Program_Error (Loc,
3161 Reason => PE_Unchecked_Union_Restriction));
3166 Build_Record_Or_Elementary_Output_Procedure
3167 (Loc, Base_Type (U_Type), Decl, Pname);
3168 Insert_Action (N, Decl);
3172 -- If we fall through, Pname is the name of the procedure to call
3174 Rewrite_Stream_Proc_Call (Pname);
3181 -- For enumeration types with a standard representation, Pos is
3182 -- handled by the back end.
3184 -- For enumeration types, with a non-standard representation we
3185 -- generate a call to the _Rep_To_Pos function created when the
3186 -- type was frozen. The call has the form
3188 -- _rep_to_pos (expr, flag)
3190 -- The parameter flag is True if range checks are enabled, causing
3191 -- Program_Error to be raised if the expression has an invalid
3192 -- representation, and False if range checks are suppressed.
3194 -- For integer types, Pos is equivalent to a simple integer
3195 -- conversion and we rewrite it as such
3197 when Attribute_Pos => Pos :
3199 Etyp : Entity_Id := Base_Type (Entity (Pref));
3202 -- Deal with zero/non-zero boolean values
3204 if Is_Boolean_Type (Etyp) then
3205 Adjust_Condition (First (Exprs));
3206 Etyp := Standard_Boolean;
3207 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
3210 -- Case of enumeration type
3212 if Is_Enumeration_Type (Etyp) then
3214 -- Non-standard enumeration type (generate call)
3216 if Present (Enum_Pos_To_Rep (Etyp)) then
3217 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
3220 Make_Function_Call (Loc,
3222 New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3223 Parameter_Associations => Exprs)));
3225 Analyze_And_Resolve (N, Typ);
3227 -- Standard enumeration type (do universal integer check)
3230 Apply_Universal_Integer_Attribute_Checks (N);
3233 -- Deal with integer types (replace by conversion)
3235 elsif Is_Integer_Type (Etyp) then
3236 Rewrite (N, Convert_To (Typ, First (Exprs)));
3237 Analyze_And_Resolve (N, Typ);
3246 -- We compute this if a component clause was present, otherwise we leave
3247 -- the computation up to the back end, since we don't know what layout
3250 when Attribute_Position => Position :
3252 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3255 if Present (Component_Clause (CE)) then
3257 Make_Integer_Literal (Loc,
3258 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
3259 Analyze_And_Resolve (N, Typ);
3262 Apply_Universal_Integer_Attribute_Checks (N);
3270 -- 1. Deal with enumeration types with holes
3271 -- 2. For floating-point, generate call to attribute function
3272 -- 3. For other cases, deal with constraint checking
3274 when Attribute_Pred => Pred :
3276 Etyp : constant Entity_Id := Base_Type (Ptyp);
3280 -- For enumeration types with non-standard representations, we
3281 -- expand typ'Pred (x) into
3283 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
3285 -- If the representation is contiguous, we compute instead
3286 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
3287 -- The conversion function Enum_Pos_To_Rep is defined on the
3288 -- base type, not the subtype, so we have to use the base type
3289 -- explicitly for this and other enumeration attributes.
3291 if Is_Enumeration_Type (Ptyp)
3292 and then Present (Enum_Pos_To_Rep (Etyp))
3294 if Has_Contiguous_Rep (Etyp) then
3296 Unchecked_Convert_To (Ptyp,
3299 Make_Integer_Literal (Loc,
3300 Enumeration_Rep (First_Literal (Ptyp))),
3302 Make_Function_Call (Loc,
3305 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3307 Parameter_Associations =>
3309 Unchecked_Convert_To (Ptyp,
3310 Make_Op_Subtract (Loc,
3312 Unchecked_Convert_To (Standard_Integer,
3313 Relocate_Node (First (Exprs))),
3315 Make_Integer_Literal (Loc, 1))),
3316 Rep_To_Pos_Flag (Ptyp, Loc))))));
3319 -- Add Boolean parameter True, to request program errror if
3320 -- we have a bad representation on our hands. If checks are
3321 -- suppressed, then add False instead
3323 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
3325 Make_Indexed_Component (Loc,
3328 (Enum_Pos_To_Rep (Etyp), Loc),
3329 Expressions => New_List (
3330 Make_Op_Subtract (Loc,
3332 Make_Function_Call (Loc,
3335 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3336 Parameter_Associations => Exprs),
3337 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
3340 Analyze_And_Resolve (N, Typ);
3342 -- For floating-point, we transform 'Pred into a call to the Pred
3343 -- floating-point attribute function in Fat_xxx (xxx is root type)
3345 elsif Is_Floating_Point_Type (Ptyp) then
3346 Expand_Fpt_Attribute_R (N);
3347 Analyze_And_Resolve (N, Typ);
3349 -- For modular types, nothing to do (no overflow, since wraps)
3351 elsif Is_Modular_Integer_Type (Ptyp) then
3354 -- For other types, if range checking is enabled, we must generate
3355 -- a check if overflow checking is enabled.
3357 elsif not Overflow_Checks_Suppressed (Ptyp) then
3358 Expand_Pred_Succ (N);
3366 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3368 -- We rewrite X'Priority as the following run-time call:
3370 -- Get_Ceiling (X._Object)
3372 -- Note that although X'Priority is notionally an object, it is quite
3373 -- deliberately not defined as an aliased object in the RM. This means
3374 -- that it works fine to rewrite it as a call, without having to worry
3375 -- about complications that would other arise from X'Priority'Access,
3376 -- which is illegal, because of the lack of aliasing.
3378 when Attribute_Priority =>
3381 Conctyp : Entity_Id;
3382 Object_Parm : Node_Id;
3384 RT_Subprg_Name : Node_Id;
3387 -- Look for the enclosing concurrent type
3389 Conctyp := Current_Scope;
3390 while not Is_Concurrent_Type (Conctyp) loop
3391 Conctyp := Scope (Conctyp);
3394 pragma Assert (Is_Protected_Type (Conctyp));
3396 -- Generate the actual of the call
3398 Subprg := Current_Scope;
3399 while not Present (Protected_Body_Subprogram (Subprg)) loop
3400 Subprg := Scope (Subprg);
3403 -- Use of 'Priority inside protected entries and barriers (in
3404 -- both cases the type of the first formal of their expanded
3405 -- subprogram is Address)
3407 if Etype (First_Entity (Protected_Body_Subprogram (Subprg)))
3411 New_Itype : Entity_Id;
3414 -- In the expansion of protected entries the type of the
3415 -- first formal of the Protected_Body_Subprogram is an
3416 -- Address. In order to reference the _object component
3419 -- type T is access p__ptTV;
3422 New_Itype := Create_Itype (E_Access_Type, N);
3423 Set_Etype (New_Itype, New_Itype);
3424 Set_Directly_Designated_Type (New_Itype,
3425 Corresponding_Record_Type (Conctyp));
3426 Freeze_Itype (New_Itype, N);
3429 -- T!(O)._object'unchecked_access
3432 Make_Attribute_Reference (Loc,
3434 Make_Selected_Component (Loc,
3436 Unchecked_Convert_To (New_Itype,
3439 (Protected_Body_Subprogram (Subprg)),
3442 Make_Identifier (Loc, Name_uObject)),
3443 Attribute_Name => Name_Unchecked_Access);
3446 -- Use of 'Priority inside a protected subprogram
3450 Make_Attribute_Reference (Loc,
3452 Make_Selected_Component (Loc,
3453 Prefix => New_Reference_To
3455 (Protected_Body_Subprogram (Subprg)),
3458 Make_Identifier (Loc, Name_uObject)),
3459 Attribute_Name => Name_Unchecked_Access);
3462 -- Select the appropriate run-time subprogram
3464 if Number_Entries (Conctyp) = 0 then
3466 New_Reference_To (RTE (RE_Get_Ceiling), Loc);
3469 New_Reference_To (RTE (RO_PE_Get_Ceiling), Loc);
3473 Make_Function_Call (Loc,
3474 Name => RT_Subprg_Name,
3475 Parameter_Associations => New_List (Object_Parm));
3479 -- Avoid the generation of extra checks on the pointer to the
3480 -- protected object.
3482 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
3489 when Attribute_Range_Length => Range_Length : begin
3490 -- The only special processing required is for the case where
3491 -- Range_Length is applied to an enumeration type with holes.
3492 -- In this case we transform
3498 -- X'Pos (X'Last) - X'Pos (X'First) + 1
3500 -- So that the result reflects the proper Pos values instead
3501 -- of the underlying representations.
3503 if Is_Enumeration_Type (Ptyp)
3504 and then Has_Non_Standard_Rep (Ptyp)
3509 Make_Op_Subtract (Loc,
3511 Make_Attribute_Reference (Loc,
3512 Attribute_Name => Name_Pos,
3513 Prefix => New_Occurrence_Of (Ptyp, Loc),
3514 Expressions => New_List (
3515 Make_Attribute_Reference (Loc,
3516 Attribute_Name => Name_Last,
3517 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
3520 Make_Attribute_Reference (Loc,
3521 Attribute_Name => Name_Pos,
3522 Prefix => New_Occurrence_Of (Ptyp, Loc),
3523 Expressions => New_List (
3524 Make_Attribute_Reference (Loc,
3525 Attribute_Name => Name_First,
3526 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
3529 Make_Integer_Literal (Loc, 1)));
3531 Analyze_And_Resolve (N, Typ);
3533 -- For all other cases, the attribute is handled by the back end, but
3534 -- we need to deal with the case of the range check on a universal
3538 Apply_Universal_Integer_Attribute_Checks (N);
3546 when Attribute_Read => Read : declare
3547 P_Type : constant Entity_Id := Entity (Pref);
3548 B_Type : constant Entity_Id := Base_Type (P_Type);
3549 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3559 -- If no underlying type, we have an error that will be diagnosed
3560 -- elsewhere, so here we just completely ignore the expansion.
3566 -- The simple case, if there is a TSS for Read, just call it
3568 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
3570 if Present (Pname) then
3574 -- If there is a Stream_Convert pragma, use it, we rewrite
3576 -- sourcetyp'Read (stream, Item)
3580 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
3582 -- where strmread is the given Read function that converts an
3583 -- argument of type strmtyp to type sourcetyp or a type from which
3584 -- it is derived. The conversion to sourcetyp is required in the
3587 -- A special case arises if Item is a type conversion in which
3588 -- case, we have to expand to:
3590 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
3592 -- where Itemx is the expression of the type conversion (i.e.
3593 -- the actual object), and typex is the type of Itemx.
3595 Prag := Get_Stream_Convert_Pragma (P_Type);
3597 if Present (Prag) then
3598 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3599 Rfunc := Entity (Expression (Arg2));
3600 Lhs := Relocate_Node (Next (First (Exprs)));
3602 OK_Convert_To (B_Type,
3603 Make_Function_Call (Loc,
3604 Name => New_Occurrence_Of (Rfunc, Loc),
3605 Parameter_Associations => New_List (
3606 Make_Attribute_Reference (Loc,
3609 (Etype (First_Formal (Rfunc)), Loc),
3610 Attribute_Name => Name_Input,
3611 Expressions => New_List (
3612 Relocate_Node (First (Exprs)))))));
3614 if Nkind (Lhs) = N_Type_Conversion then
3615 Lhs := Expression (Lhs);
3616 Rhs := Convert_To (Etype (Lhs), Rhs);
3620 Make_Assignment_Statement (Loc,
3622 Expression => Rhs));
3623 Set_Assignment_OK (Lhs);
3627 -- For elementary types, we call the I_xxx routine using the first
3628 -- parameter and then assign the result into the second parameter.
3629 -- We set Assignment_OK to deal with the conversion case.
3631 elsif Is_Elementary_Type (U_Type) then
3637 Lhs := Relocate_Node (Next (First (Exprs)));
3638 Rhs := Build_Elementary_Input_Call (N);
3640 if Nkind (Lhs) = N_Type_Conversion then
3641 Lhs := Expression (Lhs);
3642 Rhs := Convert_To (Etype (Lhs), Rhs);
3645 Set_Assignment_OK (Lhs);
3648 Make_Assignment_Statement (Loc,
3650 Expression => Rhs));
3658 elsif Is_Array_Type (U_Type) then
3659 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
3660 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3662 -- Tagged type case, use the primitive Read function. Note that
3663 -- this will dispatch in the class-wide case which is what we want
3665 elsif Is_Tagged_Type (U_Type) then
3666 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
3668 -- All other record type cases, including protected records. The
3669 -- latter only arise for expander generated code for handling
3670 -- shared passive partition access.
3674 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3676 -- Ada 2005 (AI-216): Program_Error is raised when executing
3677 -- the default implementation of the Read attribute of an
3678 -- Unchecked_Union type.
3680 if Is_Unchecked_Union (Base_Type (U_Type)) then
3682 Make_Raise_Program_Error (Loc,
3683 Reason => PE_Unchecked_Union_Restriction));
3686 if Has_Discriminants (U_Type)
3688 (Discriminant_Default_Value (First_Discriminant (U_Type)))
3690 Build_Mutable_Record_Read_Procedure
3691 (Loc, Base_Type (U_Type), Decl, Pname);
3693 Build_Record_Read_Procedure
3694 (Loc, Base_Type (U_Type), Decl, Pname);
3697 -- Suppress checks, uninitialized or otherwise invalid
3698 -- data does not cause constraint errors to be raised for
3699 -- a complete record read.
3701 Insert_Action (N, Decl, All_Checks);
3705 Rewrite_Stream_Proc_Call (Pname);
3712 -- Transforms 'Remainder into a call to the floating-point attribute
3713 -- function Remainder in Fat_xxx (where xxx is the root type)
3715 when Attribute_Remainder =>
3716 Expand_Fpt_Attribute_RR (N);
3722 -- Transform 'Result into reference to _Result formal. At the point
3723 -- where a legal 'Result attribute is expanded, we know that we are in
3724 -- the context of a _Postcondition function with a _Result parameter.
3726 when Attribute_Result =>
3728 Make_Identifier (Loc,
3729 Chars => Name_uResult));
3730 Analyze_And_Resolve (N, Typ);
3736 -- The handling of the Round attribute is quite delicate. The processing
3737 -- in Sem_Attr introduced a conversion to universal real, reflecting the
3738 -- semantics of Round, but we do not want anything to do with universal
3739 -- real at runtime, since this corresponds to using floating-point
3742 -- What we have now is that the Etype of the Round attribute correctly
3743 -- indicates the final result type. The operand of the Round is the
3744 -- conversion to universal real, described above, and the operand of
3745 -- this conversion is the actual operand of Round, which may be the
3746 -- special case of a fixed point multiplication or division (Etype =
3749 -- The exapander will expand first the operand of the conversion, then
3750 -- the conversion, and finally the round attribute itself, since we
3751 -- always work inside out. But we cannot simply process naively in this
3752 -- order. In the semantic world where universal fixed and real really
3753 -- exist and have infinite precision, there is no problem, but in the
3754 -- implementation world, where universal real is a floating-point type,
3755 -- we would get the wrong result.
3757 -- So the approach is as follows. First, when expanding a multiply or
3758 -- divide whose type is universal fixed, we do nothing at all, instead
3759 -- deferring the operation till later.
3761 -- The actual processing is done in Expand_N_Type_Conversion which
3762 -- handles the special case of Round by looking at its parent to see if
3763 -- it is a Round attribute, and if it is, handling the conversion (or
3764 -- its fixed multiply/divide child) in an appropriate manner.
3766 -- This means that by the time we get to expanding the Round attribute
3767 -- itself, the Round is nothing more than a type conversion (and will
3768 -- often be a null type conversion), so we just replace it with the
3769 -- appropriate conversion operation.
3771 when Attribute_Round =>
3773 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
3774 Analyze_And_Resolve (N);
3780 -- Transforms 'Rounding into a call to the floating-point attribute
3781 -- function Rounding in Fat_xxx (where xxx is the root type)
3783 when Attribute_Rounding =>
3784 Expand_Fpt_Attribute_R (N);
3790 -- Transforms 'Scaling into a call to the floating-point attribute
3791 -- function Scaling in Fat_xxx (where xxx is the root type)
3793 when Attribute_Scaling =>
3794 Expand_Fpt_Attribute_RI (N);
3800 when Attribute_Size |
3801 Attribute_Object_Size |
3802 Attribute_Value_Size |
3803 Attribute_VADS_Size => Size :
3810 -- Processing for VADS_Size case. Note that this processing removes
3811 -- all traces of VADS_Size from the tree, and completes all required
3812 -- processing for VADS_Size by translating the attribute reference
3813 -- to an appropriate Size or Object_Size reference.
3815 if Id = Attribute_VADS_Size
3816 or else (Use_VADS_Size and then Id = Attribute_Size)
3818 -- If the size is specified, then we simply use the specified
3819 -- size. This applies to both types and objects. The size of an
3820 -- object can be specified in the following ways:
3822 -- An explicit size object is given for an object
3823 -- A component size is specified for an indexed component
3824 -- A component clause is specified for a selected component
3825 -- The object is a component of a packed composite object
3827 -- If the size is specified, then VADS_Size of an object
3829 if (Is_Entity_Name (Pref)
3830 and then Present (Size_Clause (Entity (Pref))))
3832 (Nkind (Pref) = N_Component_Clause
3833 and then (Present (Component_Clause
3834 (Entity (Selector_Name (Pref))))
3835 or else Is_Packed (Etype (Prefix (Pref)))))
3837 (Nkind (Pref) = N_Indexed_Component
3838 and then (Component_Size (Etype (Prefix (Pref))) /= 0
3839 or else Is_Packed (Etype (Prefix (Pref)))))
3841 Set_Attribute_Name (N, Name_Size);
3843 -- Otherwise if we have an object rather than a type, then the
3844 -- VADS_Size attribute applies to the type of the object, rather
3845 -- than the object itself. This is one of the respects in which
3846 -- VADS_Size differs from Size.
3849 if (not Is_Entity_Name (Pref)
3850 or else not Is_Type (Entity (Pref)))
3851 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
3853 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
3856 -- For a scalar type for which no size was explicitly given,
3857 -- VADS_Size means Object_Size. This is the other respect in
3858 -- which VADS_Size differs from Size.
3860 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
3861 Set_Attribute_Name (N, Name_Object_Size);
3863 -- In all other cases, Size and VADS_Size are the sane
3866 Set_Attribute_Name (N, Name_Size);
3871 -- For class-wide types, X'Class'Size is transformed into a direct
3872 -- reference to the Size of the class type, so that the back end does
3873 -- not have to deal with the X'Class'Size reference.
3875 if Is_Entity_Name (Pref)
3876 and then Is_Class_Wide_Type (Entity (Pref))
3878 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
3881 -- For X'Size applied to an object of a class-wide type, transform
3882 -- X'Size into a call to the primitive operation _Size applied to X.
3884 elsif Is_Class_Wide_Type (Ptyp) then
3886 -- No need to do anything else compiling under restriction
3887 -- No_Dispatching_Calls. During the semantic analysis we
3888 -- already notified such violation.
3890 if Restriction_Active (No_Dispatching_Calls) then
3895 Make_Function_Call (Loc,
3896 Name => New_Reference_To
3897 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
3898 Parameter_Associations => New_List (Pref));
3900 if Typ /= Standard_Long_Long_Integer then
3902 -- The context is a specific integer type with which the
3903 -- original attribute was compatible. The function has a
3904 -- specific type as well, so to preserve the compatibility
3905 -- we must convert explicitly.
3907 New_Node := Convert_To (Typ, New_Node);
3910 Rewrite (N, New_Node);
3911 Analyze_And_Resolve (N, Typ);
3914 -- Case of known RM_Size of a type
3916 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
3917 and then Is_Entity_Name (Pref)
3918 and then Is_Type (Entity (Pref))
3919 and then Known_Static_RM_Size (Entity (Pref))
3921 Siz := RM_Size (Entity (Pref));
3923 -- Case of known Esize of a type
3925 elsif Id = Attribute_Object_Size
3926 and then Is_Entity_Name (Pref)
3927 and then Is_Type (Entity (Pref))
3928 and then Known_Static_Esize (Entity (Pref))
3930 Siz := Esize (Entity (Pref));
3932 -- Case of known size of object
3934 elsif Id = Attribute_Size
3935 and then Is_Entity_Name (Pref)
3936 and then Is_Object (Entity (Pref))
3937 and then Known_Esize (Entity (Pref))
3938 and then Known_Static_Esize (Entity (Pref))
3940 Siz := Esize (Entity (Pref));
3942 -- For an array component, we can do Size in the front end
3943 -- if the component_size of the array is set.
3945 elsif Nkind (Pref) = N_Indexed_Component then
3946 Siz := Component_Size (Etype (Prefix (Pref)));
3948 -- For a record component, we can do Size in the front end if there
3949 -- is a component clause, or if the record is packed and the
3950 -- component's size is known at compile time.
3952 elsif Nkind (Pref) = N_Selected_Component then
3954 Rec : constant Entity_Id := Etype (Prefix (Pref));
3955 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
3958 if Present (Component_Clause (Comp)) then
3959 Siz := Esize (Comp);
3961 elsif Is_Packed (Rec) then
3962 Siz := RM_Size (Ptyp);
3965 Apply_Universal_Integer_Attribute_Checks (N);
3970 -- All other cases are handled by the back end
3973 Apply_Universal_Integer_Attribute_Checks (N);
3975 -- If Size is applied to a formal parameter that is of a packed
3976 -- array subtype, then apply Size to the actual subtype.
3978 if Is_Entity_Name (Pref)
3979 and then Is_Formal (Entity (Pref))
3980 and then Is_Array_Type (Ptyp)
3981 and then Is_Packed (Ptyp)
3984 Make_Attribute_Reference (Loc,
3986 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
3987 Attribute_Name => Name_Size));
3988 Analyze_And_Resolve (N, Typ);
3991 -- If Size applies to a dereference of an access to unconstrained
3992 -- packed array, the back end needs to see its unconstrained
3993 -- nominal type, but also a hint to the actual constrained type.
3995 if Nkind (Pref) = N_Explicit_Dereference
3996 and then Is_Array_Type (Ptyp)
3997 and then not Is_Constrained (Ptyp)
3998 and then Is_Packed (Ptyp)
4000 Set_Actual_Designated_Subtype (Pref,
4001 Get_Actual_Subtype (Pref));
4007 -- Common processing for record and array component case
4009 if Siz /= No_Uint and then Siz /= 0 then
4011 CS : constant Boolean := Comes_From_Source (N);
4014 Rewrite (N, Make_Integer_Literal (Loc, Siz));
4016 -- This integer literal is not a static expression. We do not
4017 -- call Analyze_And_Resolve here, because this would activate
4018 -- the circuit for deciding that a static value was out of
4019 -- range, and we don't want that.
4021 -- So just manually set the type, mark the expression as non-
4022 -- static, and then ensure that the result is checked properly
4023 -- if the attribute comes from source (if it was internally
4024 -- generated, we never need a constraint check).
4027 Set_Is_Static_Expression (N, False);
4030 Apply_Constraint_Check (N, Typ);
4040 when Attribute_Storage_Pool =>
4042 Make_Type_Conversion (Loc,
4043 Subtype_Mark => New_Reference_To (Etype (N), Loc),
4044 Expression => New_Reference_To (Entity (N), Loc)));
4045 Analyze_And_Resolve (N, Typ);
4051 when Attribute_Storage_Size => Storage_Size : begin
4053 -- Access type case, always go to the root type
4055 -- The case of access types results in a value of zero for the case
4056 -- where no storage size attribute clause has been given. If a
4057 -- storage size has been given, then the attribute is converted
4058 -- to a reference to the variable used to hold this value.
4060 if Is_Access_Type (Ptyp) then
4061 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
4063 Make_Attribute_Reference (Loc,
4064 Prefix => New_Reference_To (Typ, Loc),
4065 Attribute_Name => Name_Max,
4066 Expressions => New_List (
4067 Make_Integer_Literal (Loc, 0),
4070 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
4072 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
4075 Make_Function_Call (Loc,
4079 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
4080 Attribute_Name (N)),
4083 Parameter_Associations => New_List (
4085 (Associated_Storage_Pool (Root_Type (Ptyp)), Loc)))));
4088 Rewrite (N, Make_Integer_Literal (Loc, 0));
4091 Analyze_And_Resolve (N, Typ);
4093 -- For tasks, we retrieve the size directly from the TCB. The
4094 -- size may depend on a discriminant of the type, and therefore
4095 -- can be a per-object expression, so type-level information is
4096 -- not sufficient in general. There are four cases to consider:
4098 -- a) If the attribute appears within a task body, the designated
4099 -- TCB is obtained by a call to Self.
4101 -- b) If the prefix of the attribute is the name of a task object,
4102 -- the designated TCB is the one stored in the corresponding record.
4104 -- c) If the prefix is a task type, the size is obtained from the
4105 -- size variable created for each task type
4107 -- d) If no storage_size was specified for the type , there is no
4108 -- size variable, and the value is a system-specific default.
4111 if In_Open_Scopes (Ptyp) then
4113 -- Storage_Size (Self)
4117 Make_Function_Call (Loc,
4119 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4120 Parameter_Associations =>
4122 Make_Function_Call (Loc,
4124 New_Reference_To (RTE (RE_Self), Loc))))));
4126 elsif not Is_Entity_Name (Pref)
4127 or else not Is_Type (Entity (Pref))
4129 -- Storage_Size (Rec (Obj).Size)
4133 Make_Function_Call (Loc,
4135 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4136 Parameter_Associations =>
4138 Make_Selected_Component (Loc,
4140 Unchecked_Convert_To (
4141 Corresponding_Record_Type (Ptyp),
4142 New_Copy_Tree (Pref)),
4144 Make_Identifier (Loc, Name_uTask_Id))))));
4146 elsif Present (Storage_Size_Variable (Ptyp)) then
4148 -- Static storage size pragma given for type: retrieve value
4149 -- from its allocated storage variable.
4153 Make_Function_Call (Loc,
4154 Name => New_Occurrence_Of (
4155 RTE (RE_Adjust_Storage_Size), Loc),
4156 Parameter_Associations =>
4159 Storage_Size_Variable (Ptyp), Loc)))));
4161 -- Get system default
4165 Make_Function_Call (Loc,
4168 RTE (RE_Default_Stack_Size), Loc))));
4171 Analyze_And_Resolve (N, Typ);
4179 when Attribute_Stream_Size => Stream_Size : declare
4183 -- If we have a Stream_Size clause for this type use it, otherwise
4184 -- the Stream_Size if the size of the type.
4186 if Has_Stream_Size_Clause (Ptyp) then
4189 (Static_Integer (Expression (Stream_Size_Clause (Ptyp))));
4191 Size := UI_To_Int (Esize (Ptyp));
4194 Rewrite (N, Make_Integer_Literal (Loc, Intval => Size));
4195 Analyze_And_Resolve (N, Typ);
4202 -- 1. Deal with enumeration types with holes
4203 -- 2. For floating-point, generate call to attribute function
4204 -- 3. For other cases, deal with constraint checking
4206 when Attribute_Succ => Succ :
4208 Etyp : constant Entity_Id := Base_Type (Ptyp);
4212 -- For enumeration types with non-standard representations, we
4213 -- expand typ'Succ (x) into
4215 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
4217 -- If the representation is contiguous, we compute instead
4218 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
4220 if Is_Enumeration_Type (Ptyp)
4221 and then Present (Enum_Pos_To_Rep (Etyp))
4223 if Has_Contiguous_Rep (Etyp) then
4225 Unchecked_Convert_To (Ptyp,
4228 Make_Integer_Literal (Loc,
4229 Enumeration_Rep (First_Literal (Ptyp))),
4231 Make_Function_Call (Loc,
4234 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4236 Parameter_Associations =>
4238 Unchecked_Convert_To (Ptyp,
4241 Unchecked_Convert_To (Standard_Integer,
4242 Relocate_Node (First (Exprs))),
4244 Make_Integer_Literal (Loc, 1))),
4245 Rep_To_Pos_Flag (Ptyp, Loc))))));
4247 -- Add Boolean parameter True, to request program errror if
4248 -- we have a bad representation on our hands. Add False if
4249 -- checks are suppressed.
4251 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4253 Make_Indexed_Component (Loc,
4256 (Enum_Pos_To_Rep (Etyp), Loc),
4257 Expressions => New_List (
4260 Make_Function_Call (Loc,
4263 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4264 Parameter_Associations => Exprs),
4265 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4268 Analyze_And_Resolve (N, Typ);
4270 -- For floating-point, we transform 'Succ into a call to the Succ
4271 -- floating-point attribute function in Fat_xxx (xxx is root type)
4273 elsif Is_Floating_Point_Type (Ptyp) then
4274 Expand_Fpt_Attribute_R (N);
4275 Analyze_And_Resolve (N, Typ);
4277 -- For modular types, nothing to do (no overflow, since wraps)
4279 elsif Is_Modular_Integer_Type (Ptyp) then
4282 -- For other types, if range checking is enabled, we must generate
4283 -- a check if overflow checking is enabled.
4285 elsif not Overflow_Checks_Suppressed (Ptyp) then
4286 Expand_Pred_Succ (N);
4294 -- Transforms X'Tag into a direct reference to the tag of X
4296 when Attribute_Tag => Tag :
4299 Prefix_Is_Type : Boolean;
4302 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
4303 Ttyp := Entity (Pref);
4304 Prefix_Is_Type := True;
4307 Prefix_Is_Type := False;
4310 if Is_Class_Wide_Type (Ttyp) then
4311 Ttyp := Root_Type (Ttyp);
4314 Ttyp := Underlying_Type (Ttyp);
4316 if Prefix_Is_Type then
4318 -- For VMs we leave the type attribute unexpanded because
4319 -- there's not a dispatching table to reference.
4321 if VM_Target = No_VM then
4323 Unchecked_Convert_To (RTE (RE_Tag),
4325 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
4326 Analyze_And_Resolve (N, RTE (RE_Tag));
4329 -- (Ada 2005 (AI-251): The use of 'Tag in the sources always
4330 -- references the primary tag of the actual object. If 'Tag is
4331 -- applied to class-wide interface objects we generate code that
4332 -- displaces "this" to reference the base of the object.
4334 elsif Comes_From_Source (N)
4335 and then Is_Class_Wide_Type (Etype (Prefix (N)))
4336 and then Is_Interface (Etype (Prefix (N)))
4339 -- (To_Tag_Ptr (Prefix'Address)).all
4341 -- Note that Prefix'Address is recursively expanded into a call
4342 -- to Base_Address (Obj.Tag)
4344 -- Not needed for VM targets, since all handled by the VM
4346 if VM_Target = No_VM then
4348 Make_Explicit_Dereference (Loc,
4349 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
4350 Make_Attribute_Reference (Loc,
4351 Prefix => Relocate_Node (Pref),
4352 Attribute_Name => Name_Address))));
4353 Analyze_And_Resolve (N, RTE (RE_Tag));
4358 Make_Selected_Component (Loc,
4359 Prefix => Relocate_Node (Pref),
4361 New_Reference_To (First_Tag_Component (Ttyp), Loc)));
4362 Analyze_And_Resolve (N, RTE (RE_Tag));
4370 -- Transforms 'Terminated attribute into a call to Terminated function
4372 when Attribute_Terminated => Terminated :
4374 -- The prefix of Terminated is of a task interface class-wide type.
4377 -- terminated (Task_Id (Pref._disp_get_task_id));
4379 if Ada_Version >= Ada_05
4380 and then Ekind (Ptyp) = E_Class_Wide_Type
4381 and then Is_Interface (Ptyp)
4382 and then Is_Task_Interface (Ptyp)
4385 Make_Function_Call (Loc,
4387 New_Reference_To (RTE (RE_Terminated), Loc),
4388 Parameter_Associations => New_List (
4389 Make_Unchecked_Type_Conversion (Loc,
4391 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
4393 Make_Selected_Component (Loc,
4395 New_Copy_Tree (Pref),
4397 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
4399 elsif Restricted_Profile then
4401 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
4405 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
4408 Analyze_And_Resolve (N, Standard_Boolean);
4415 -- Transforms System'To_Address (X) into unchecked conversion
4416 -- from (integral) type of X to type address.
4418 when Attribute_To_Address =>
4420 Unchecked_Convert_To (RTE (RE_Address),
4421 Relocate_Node (First (Exprs))));
4422 Analyze_And_Resolve (N, RTE (RE_Address));
4428 when Attribute_To_Any => To_Any : declare
4429 P_Type : constant Entity_Id := Etype (Pref);
4430 Decls : constant List_Id := New_List;
4434 (Convert_To (P_Type,
4435 Relocate_Node (First (Exprs))), Decls));
4436 Insert_Actions (N, Decls);
4437 Analyze_And_Resolve (N, RTE (RE_Any));
4444 -- Transforms 'Truncation into a call to the floating-point attribute
4445 -- function Truncation in Fat_xxx (where xxx is the root type).
4446 -- Expansion is avoided for cases the back end can handle directly.
4448 when Attribute_Truncation =>
4449 if not Is_Inline_Floating_Point_Attribute (N) then
4450 Expand_Fpt_Attribute_R (N);
4457 when Attribute_TypeCode => TypeCode : declare
4458 P_Type : constant Entity_Id := Etype (Pref);
4459 Decls : constant List_Id := New_List;
4461 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
4462 Insert_Actions (N, Decls);
4463 Analyze_And_Resolve (N, RTE (RE_TypeCode));
4466 -----------------------
4467 -- Unbiased_Rounding --
4468 -----------------------
4470 -- Transforms 'Unbiased_Rounding into a call to the floating-point
4471 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
4472 -- root type). Expansion is avoided for cases the back end can handle
4475 when Attribute_Unbiased_Rounding =>
4476 if not Is_Inline_Floating_Point_Attribute (N) then
4477 Expand_Fpt_Attribute_R (N);
4484 when Attribute_UET_Address => UET_Address : declare
4485 Ent : constant Entity_Id :=
4486 Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
4490 Make_Object_Declaration (Loc,
4491 Defining_Identifier => Ent,
4492 Aliased_Present => True,
4493 Object_Definition =>
4494 New_Occurrence_Of (RTE (RE_Address), Loc)));
4496 -- Construct name __gnat_xxx__SDP, where xxx is the unit name
4497 -- in normal external form.
4499 Get_External_Unit_Name_String (Get_Unit_Name (Pref));
4500 Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
4501 Name_Len := Name_Len + 7;
4502 Name_Buffer (1 .. 7) := "__gnat_";
4503 Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
4504 Name_Len := Name_Len + 5;
4506 Set_Is_Imported (Ent);
4507 Set_Interface_Name (Ent,
4508 Make_String_Literal (Loc,
4509 Strval => String_From_Name_Buffer));
4511 -- Set entity as internal to ensure proper Sprint output of its
4512 -- implicit importation.
4514 Set_Is_Internal (Ent);
4517 Make_Attribute_Reference (Loc,
4518 Prefix => New_Occurrence_Of (Ent, Loc),
4519 Attribute_Name => Name_Address));
4521 Analyze_And_Resolve (N, Typ);
4528 -- The processing for VADS_Size is shared with Size
4534 -- For enumeration types with a standard representation, and for all
4535 -- other types, Val is handled by the back end. For enumeration types
4536 -- with a non-standard representation we use the _Pos_To_Rep array that
4537 -- was created when the type was frozen.
4539 when Attribute_Val => Val :
4541 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
4544 if Is_Enumeration_Type (Etyp)
4545 and then Present (Enum_Pos_To_Rep (Etyp))
4547 if Has_Contiguous_Rep (Etyp) then
4549 Rep_Node : constant Node_Id :=
4550 Unchecked_Convert_To (Etyp,
4553 Make_Integer_Literal (Loc,
4554 Enumeration_Rep (First_Literal (Etyp))),
4556 (Convert_To (Standard_Integer,
4557 Relocate_Node (First (Exprs))))));
4561 Unchecked_Convert_To (Etyp,
4564 Make_Integer_Literal (Loc,
4565 Enumeration_Rep (First_Literal (Etyp))),
4567 Make_Function_Call (Loc,
4570 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4571 Parameter_Associations => New_List (
4573 Rep_To_Pos_Flag (Etyp, Loc))))));
4578 Make_Indexed_Component (Loc,
4579 Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
4580 Expressions => New_List (
4581 Convert_To (Standard_Integer,
4582 Relocate_Node (First (Exprs))))));
4585 Analyze_And_Resolve (N, Typ);
4593 -- The code for valid is dependent on the particular types involved.
4594 -- See separate sections below for the generated code in each case.
4596 when Attribute_Valid => Valid :
4598 Btyp : Entity_Id := Base_Type (Ptyp);
4601 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
4602 -- Save the validity checking mode. We always turn off validity
4603 -- checking during process of 'Valid since this is one place
4604 -- where we do not want the implicit validity checks to intefere
4605 -- with the explicit validity check that the programmer is doing.
4607 function Make_Range_Test return Node_Id;
4608 -- Build the code for a range test of the form
4609 -- Btyp!(Pref) >= Btyp!(Ptyp'First)
4611 -- Btyp!(Pref) <= Btyp!(Ptyp'Last)
4613 ---------------------
4614 -- Make_Range_Test --
4615 ---------------------
4617 function Make_Range_Test return Node_Id is
4624 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4627 Unchecked_Convert_To (Btyp,
4628 Make_Attribute_Reference (Loc,
4629 Prefix => New_Occurrence_Of (Ptyp, Loc),
4630 Attribute_Name => Name_First))),
4635 Unchecked_Convert_To (Btyp,
4636 Duplicate_Subexpr_No_Checks (Pref)),
4639 Unchecked_Convert_To (Btyp,
4640 Make_Attribute_Reference (Loc,
4641 Prefix => New_Occurrence_Of (Ptyp, Loc),
4642 Attribute_Name => Name_Last))));
4643 end Make_Range_Test;
4645 -- Start of processing for Attribute_Valid
4648 -- Turn off validity checks. We do not want any implicit validity
4649 -- checks to intefere with the explicit check from the attribute
4651 Validity_Checks_On := False;
4653 -- Floating-point case. This case is handled by the Valid attribute
4654 -- code in the floating-point attribute run-time library.
4656 if Is_Floating_Point_Type (Ptyp) then
4662 -- For vax fpt types, call appropriate routine in special vax
4663 -- floating point unit. We do not have to worry about loads in
4664 -- this case, since these types have no signalling NaN's.
4666 if Vax_Float (Btyp) then
4667 Expand_Vax_Valid (N);
4669 -- The AAMP back end handles Valid for floating-point types
4671 elsif Is_AAMP_Float (Btyp) then
4672 Analyze_And_Resolve (Pref, Ptyp);
4673 Set_Etype (N, Standard_Boolean);
4676 -- Non VAX float case
4679 Find_Fat_Info (Ptyp, Ftp, Pkg);
4681 -- If the floating-point object might be unaligned, we need
4682 -- to call the special routine Unaligned_Valid, which makes
4683 -- the needed copy, being careful not to load the value into
4684 -- any floating-point register. The argument in this case is
4685 -- obj'Address (see Unaligned_Valid routine in Fat_Gen).
4687 if Is_Possibly_Unaligned_Object (Pref) then
4688 Expand_Fpt_Attribute
4689 (N, Pkg, Name_Unaligned_Valid,
4691 Make_Attribute_Reference (Loc,
4692 Prefix => Relocate_Node (Pref),
4693 Attribute_Name => Name_Address)));
4695 -- In the normal case where we are sure the object is
4696 -- aligned, we generate a call to Valid, and the argument in
4697 -- this case is obj'Unrestricted_Access (after converting
4698 -- obj to the right floating-point type).
4701 Expand_Fpt_Attribute
4702 (N, Pkg, Name_Valid,
4704 Make_Attribute_Reference (Loc,
4705 Prefix => Unchecked_Convert_To (Ftp, Pref),
4706 Attribute_Name => Name_Unrestricted_Access)));
4710 -- One more task, we still need a range check. Required
4711 -- only if we have a constraint, since the Valid routine
4712 -- catches infinities properly (infinities are never valid).
4714 -- The way we do the range check is simply to create the
4715 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
4717 if not Subtypes_Statically_Match (Ptyp, Btyp) then
4720 Left_Opnd => Relocate_Node (N),
4723 Left_Opnd => Convert_To (Btyp, Pref),
4724 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
4728 -- Enumeration type with holes
4730 -- For enumeration types with holes, the Pos value constructed by
4731 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
4732 -- second argument of False returns minus one for an invalid value,
4733 -- and the non-negative pos value for a valid value, so the
4734 -- expansion of X'Valid is simply:
4736 -- type(X)'Pos (X) >= 0
4738 -- We can't quite generate it that way because of the requirement
4739 -- for the non-standard second argument of False in the resulting
4740 -- rep_to_pos call, so we have to explicitly create:
4742 -- _rep_to_pos (X, False) >= 0
4744 -- If we have an enumeration subtype, we also check that the
4745 -- value is in range:
4747 -- _rep_to_pos (X, False) >= 0
4749 -- (X >= type(X)'First and then type(X)'Last <= X)
4751 elsif Is_Enumeration_Type (Ptyp)
4752 and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp)))
4757 Make_Function_Call (Loc,
4760 (TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc),
4761 Parameter_Associations => New_List (
4763 New_Occurrence_Of (Standard_False, Loc))),
4764 Right_Opnd => Make_Integer_Literal (Loc, 0));
4768 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
4770 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
4772 -- The call to Make_Range_Test will create declarations
4773 -- that need a proper insertion point, but Pref is now
4774 -- attached to a node with no ancestor. Attach to tree
4775 -- even if it is to be rewritten below.
4777 Set_Parent (Tst, Parent (N));
4781 Left_Opnd => Make_Range_Test,
4787 -- Fortran convention booleans
4789 -- For the very special case of Fortran convention booleans, the
4790 -- value is always valid, since it is an integer with the semantics
4791 -- that non-zero is true, and any value is permissible.
4793 elsif Is_Boolean_Type (Ptyp)
4794 and then Convention (Ptyp) = Convention_Fortran
4796 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
4798 -- For biased representations, we will be doing an unchecked
4799 -- conversion without unbiasing the result. That means that the range
4800 -- test has to take this into account, and the proper form of the
4803 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
4805 elsif Has_Biased_Representation (Ptyp) then
4806 Btyp := RTE (RE_Unsigned_32);
4810 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4812 Unchecked_Convert_To (Btyp,
4813 Make_Attribute_Reference (Loc,
4814 Prefix => New_Occurrence_Of (Ptyp, Loc),
4815 Attribute_Name => Name_Range_Length))));
4817 -- For all other scalar types, what we want logically is a
4820 -- X in type(X)'First .. type(X)'Last
4822 -- But that's precisely what won't work because of possible
4823 -- unwanted optimization (and indeed the basic motivation for
4824 -- the Valid attribute is exactly that this test does not work!)
4825 -- What will work is:
4827 -- Btyp!(X) >= Btyp!(type(X)'First)
4829 -- Btyp!(X) <= Btyp!(type(X)'Last)
4831 -- where Btyp is an integer type large enough to cover the full
4832 -- range of possible stored values (i.e. it is chosen on the basis
4833 -- of the size of the type, not the range of the values). We write
4834 -- this as two tests, rather than a range check, so that static
4835 -- evaluation will easily remove either or both of the checks if
4836 -- they can be -statically determined to be true (this happens
4837 -- when the type of X is static and the range extends to the full
4838 -- range of stored values).
4840 -- Unsigned types. Note: it is safe to consider only whether the
4841 -- subtype is unsigned, since we will in that case be doing all
4842 -- unsigned comparisons based on the subtype range. Since we use the
4843 -- actual subtype object size, this is appropriate.
4845 -- For example, if we have
4847 -- subtype x is integer range 1 .. 200;
4848 -- for x'Object_Size use 8;
4850 -- Now the base type is signed, but objects of this type are bits
4851 -- unsigned, and doing an unsigned test of the range 1 to 200 is
4852 -- correct, even though a value greater than 127 looks signed to a
4853 -- signed comparison.
4855 elsif Is_Unsigned_Type (Ptyp) then
4856 if Esize (Ptyp) <= 32 then
4857 Btyp := RTE (RE_Unsigned_32);
4859 Btyp := RTE (RE_Unsigned_64);
4862 Rewrite (N, Make_Range_Test);
4867 if Esize (Ptyp) <= Esize (Standard_Integer) then
4868 Btyp := Standard_Integer;
4870 Btyp := Universal_Integer;
4873 Rewrite (N, Make_Range_Test);
4876 Analyze_And_Resolve (N, Standard_Boolean);
4877 Validity_Checks_On := Save_Validity_Checks_On;
4884 -- Value attribute is handled in separate unti Exp_Imgv
4886 when Attribute_Value =>
4887 Exp_Imgv.Expand_Value_Attribute (N);
4893 -- The processing for Value_Size shares the processing for Size
4899 -- The processing for Version shares the processing for Body_Version
4905 -- Wide_Image attribute is handled in separate unit Exp_Imgv
4907 when Attribute_Wide_Image =>
4908 Exp_Imgv.Expand_Wide_Image_Attribute (N);
4910 ---------------------
4911 -- Wide_Wide_Image --
4912 ---------------------
4914 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
4916 when Attribute_Wide_Wide_Image =>
4917 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
4923 -- We expand typ'Wide_Value (X) into
4926 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
4928 -- Wide_String_To_String is a runtime function that converts its wide
4929 -- string argument to String, converting any non-translatable characters
4930 -- into appropriate escape sequences. This preserves the required
4931 -- semantics of Wide_Value in all cases, and results in a very simple
4932 -- implementation approach.
4934 -- Note: for this approach to be fully standard compliant for the cases
4935 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
4936 -- method must cover the entire character range (e.g. UTF-8). But that
4937 -- is a reasonable requirement when dealing with encoded character
4938 -- sequences. Presumably if one of the restrictive encoding mechanisms
4939 -- is in use such as Shift-JIS, then characters that cannot be
4940 -- represented using this encoding will not appear in any case.
4942 when Attribute_Wide_Value => Wide_Value :
4945 Make_Attribute_Reference (Loc,
4947 Attribute_Name => Name_Value,
4949 Expressions => New_List (
4950 Make_Function_Call (Loc,
4952 New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
4954 Parameter_Associations => New_List (
4955 Relocate_Node (First (Exprs)),
4956 Make_Integer_Literal (Loc,
4957 Intval => Int (Wide_Character_Encoding_Method)))))));
4959 Analyze_And_Resolve (N, Typ);
4962 ---------------------
4963 -- Wide_Wide_Value --
4964 ---------------------
4966 -- We expand typ'Wide_Value_Value (X) into
4969 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
4971 -- Wide_Wide_String_To_String is a runtime function that converts its
4972 -- wide string argument to String, converting any non-translatable
4973 -- characters into appropriate escape sequences. This preserves the
4974 -- required semantics of Wide_Wide_Value in all cases, and results in a
4975 -- very simple implementation approach.
4977 -- It's not quite right where typ = Wide_Wide_Character, because the
4978 -- encoding method may not cover the whole character type ???
4980 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
4983 Make_Attribute_Reference (Loc,
4985 Attribute_Name => Name_Value,
4987 Expressions => New_List (
4988 Make_Function_Call (Loc,
4990 New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc),
4992 Parameter_Associations => New_List (
4993 Relocate_Node (First (Exprs)),
4994 Make_Integer_Literal (Loc,
4995 Intval => Int (Wide_Character_Encoding_Method)))))));
4997 Analyze_And_Resolve (N, Typ);
4998 end Wide_Wide_Value;
5000 ---------------------
5001 -- Wide_Wide_Width --
5002 ---------------------
5004 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
5006 when Attribute_Wide_Wide_Width =>
5007 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
5013 -- Wide_Width attribute is handled in separate unit Exp_Imgv
5015 when Attribute_Wide_Width =>
5016 Exp_Imgv.Expand_Width_Attribute (N, Wide);
5022 -- Width attribute is handled in separate unit Exp_Imgv
5024 when Attribute_Width =>
5025 Exp_Imgv.Expand_Width_Attribute (N, Normal);
5031 when Attribute_Write => Write : declare
5032 P_Type : constant Entity_Id := Entity (Pref);
5033 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5041 -- If no underlying type, we have an error that will be diagnosed
5042 -- elsewhere, so here we just completely ignore the expansion.
5048 -- The simple case, if there is a TSS for Write, just call it
5050 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
5052 if Present (Pname) then
5056 -- If there is a Stream_Convert pragma, use it, we rewrite
5058 -- sourcetyp'Output (stream, Item)
5062 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
5064 -- where strmwrite is the given Write function that converts an
5065 -- argument of type sourcetyp or a type acctyp, from which it is
5066 -- derived to type strmtyp. The conversion to acttyp is required
5067 -- for the derived case.
5069 Prag := Get_Stream_Convert_Pragma (P_Type);
5071 if Present (Prag) then
5073 Next (Next (First (Pragma_Argument_Associations (Prag))));
5074 Wfunc := Entity (Expression (Arg3));
5077 Make_Attribute_Reference (Loc,
5078 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
5079 Attribute_Name => Name_Output,
5080 Expressions => New_List (
5081 Relocate_Node (First (Exprs)),
5082 Make_Function_Call (Loc,
5083 Name => New_Occurrence_Of (Wfunc, Loc),
5084 Parameter_Associations => New_List (
5085 OK_Convert_To (Etype (First_Formal (Wfunc)),
5086 Relocate_Node (Next (First (Exprs)))))))));
5091 -- For elementary types, we call the W_xxx routine directly
5093 elsif Is_Elementary_Type (U_Type) then
5094 Rewrite (N, Build_Elementary_Write_Call (N));
5100 elsif Is_Array_Type (U_Type) then
5101 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
5102 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5104 -- Tagged type case, use the primitive Write function. Note that
5105 -- this will dispatch in the class-wide case which is what we want
5107 elsif Is_Tagged_Type (U_Type) then
5108 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
5110 -- All other record type cases, including protected records.
5111 -- The latter only arise for expander generated code for
5112 -- handling shared passive partition access.
5116 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5118 -- Ada 2005 (AI-216): Program_Error is raised when executing
5119 -- the default implementation of the Write attribute of an
5120 -- Unchecked_Union type. However, if the 'Write reference is
5121 -- within the generated Output stream procedure, Write outputs
5122 -- the components, and the default values of the discriminant
5123 -- are streamed by the Output procedure itself.
5125 if Is_Unchecked_Union (Base_Type (U_Type))
5126 and not Is_TSS (Current_Scope, TSS_Stream_Output)
5129 Make_Raise_Program_Error (Loc,
5130 Reason => PE_Unchecked_Union_Restriction));
5133 if Has_Discriminants (U_Type)
5135 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5137 Build_Mutable_Record_Write_Procedure
5138 (Loc, Base_Type (U_Type), Decl, Pname);
5140 Build_Record_Write_Procedure
5141 (Loc, Base_Type (U_Type), Decl, Pname);
5144 Insert_Action (N, Decl);
5148 -- If we fall through, Pname is the procedure to be called
5150 Rewrite_Stream_Proc_Call (Pname);
5153 -- Component_Size is handled by the back end, unless the component size
5154 -- is known at compile time, which is always true in the packed array
5155 -- case. It is important that the packed array case is handled in the
5156 -- front end (see Eval_Attribute) since the back end would otherwise get
5157 -- confused by the equivalent packed array type.
5159 when Attribute_Component_Size =>
5162 -- The following attributes are handled by the back end (except that
5163 -- static cases have already been evaluated during semantic processing,
5164 -- but in any case the back end should not count on this). The one bit
5165 -- of special processing required is that these attributes typically
5166 -- generate conditionals in the code, so we need to check the relevant
5169 when Attribute_Max |
5171 Check_Restriction (No_Implicit_Conditionals, N);
5173 -- The following attributes are handled by the back end (except that
5174 -- static cases have already been evaluated during semantic processing,
5175 -- but in any case the back end should not count on this).
5177 -- The back end also handles the non-class-wide cases of Size
5179 when Attribute_Bit_Order |
5180 Attribute_Code_Address |
5181 Attribute_Definite |
5182 Attribute_Null_Parameter |
5183 Attribute_Passed_By_Reference |
5184 Attribute_Pool_Address =>
5187 -- The following attributes are also handled by the back end, but return
5188 -- a universal integer result, so may need a conversion for checking
5189 -- that the result is in range.
5191 when Attribute_Aft |
5193 Attribute_Max_Size_In_Storage_Elements
5195 Apply_Universal_Integer_Attribute_Checks (N);
5197 -- The following attributes should not appear at this stage, since they
5198 -- have already been handled by the analyzer (and properly rewritten
5199 -- with corresponding values or entities to represent the right values)
5201 when Attribute_Abort_Signal |
5202 Attribute_Address_Size |
5205 Attribute_Default_Bit_Order |
5212 Attribute_Fast_Math |
5213 Attribute_Has_Access_Values |
5214 Attribute_Has_Discriminants |
5215 Attribute_Has_Tagged_Values |
5217 Attribute_Machine_Emax |
5218 Attribute_Machine_Emin |
5219 Attribute_Machine_Mantissa |
5220 Attribute_Machine_Overflows |
5221 Attribute_Machine_Radix |
5222 Attribute_Machine_Rounds |
5223 Attribute_Maximum_Alignment |
5224 Attribute_Model_Emin |
5225 Attribute_Model_Epsilon |
5226 Attribute_Model_Mantissa |
5227 Attribute_Model_Small |
5229 Attribute_Partition_ID |
5231 Attribute_Safe_Emax |
5232 Attribute_Safe_First |
5233 Attribute_Safe_Large |
5234 Attribute_Safe_Last |
5235 Attribute_Safe_Small |
5237 Attribute_Signed_Zeros |
5239 Attribute_Storage_Unit |
5240 Attribute_Stub_Type |
5241 Attribute_Target_Name |
5242 Attribute_Type_Class |
5243 Attribute_Unconstrained_Array |
5244 Attribute_Universal_Literal_String |
5245 Attribute_Wchar_T_Size |
5246 Attribute_Word_Size =>
5248 raise Program_Error;
5250 -- The Asm_Input and Asm_Output attributes are not expanded at this
5251 -- stage, but will be eliminated in the expansion of the Asm call, see
5252 -- Exp_Intr for details. So the back end will never see these either.
5254 when Attribute_Asm_Input |
5255 Attribute_Asm_Output =>
5262 when RE_Not_Available =>
5264 end Expand_N_Attribute_Reference;
5266 ----------------------
5267 -- Expand_Pred_Succ --
5268 ----------------------
5270 -- For typ'Pred (exp), we generate the check
5272 -- [constraint_error when exp = typ'Base'First]
5274 -- Similarly, for typ'Succ (exp), we generate the check
5276 -- [constraint_error when exp = typ'Base'Last]
5278 -- These checks are not generated for modular types, since the proper
5279 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
5281 procedure Expand_Pred_Succ (N : Node_Id) is
5282 Loc : constant Source_Ptr := Sloc (N);
5286 if Attribute_Name (N) = Name_Pred then
5293 Make_Raise_Constraint_Error (Loc,
5297 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
5299 Make_Attribute_Reference (Loc,
5301 New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
5302 Attribute_Name => Cnam)),
5303 Reason => CE_Overflow_Check_Failed));
5304 end Expand_Pred_Succ;
5310 procedure Find_Fat_Info
5312 Fat_Type : out Entity_Id;
5313 Fat_Pkg : out RE_Id)
5315 Btyp : constant Entity_Id := Base_Type (T);
5316 Rtyp : constant Entity_Id := Root_Type (T);
5317 Digs : constant Nat := UI_To_Int (Digits_Value (Btyp));
5320 -- If the base type is VAX float, then get appropriate VAX float type
5322 if Vax_Float (Btyp) then
5325 Fat_Type := RTE (RE_Fat_VAX_F);
5326 Fat_Pkg := RE_Attr_VAX_F_Float;
5329 Fat_Type := RTE (RE_Fat_VAX_D);
5330 Fat_Pkg := RE_Attr_VAX_D_Float;
5333 Fat_Type := RTE (RE_Fat_VAX_G);
5334 Fat_Pkg := RE_Attr_VAX_G_Float;
5337 raise Program_Error;
5340 -- If root type is VAX float, this is the case where the library has
5341 -- been recompiled in VAX float mode, and we have an IEEE float type.
5342 -- This is when we use the special IEEE Fat packages.
5344 elsif Vax_Float (Rtyp) then
5347 Fat_Type := RTE (RE_Fat_IEEE_Short);
5348 Fat_Pkg := RE_Attr_IEEE_Short;
5351 Fat_Type := RTE (RE_Fat_IEEE_Long);
5352 Fat_Pkg := RE_Attr_IEEE_Long;
5355 raise Program_Error;
5358 -- If neither the base type nor the root type is VAX_Float then VAX
5359 -- float is out of the picture, and we can just use the root type.
5364 if Fat_Type = Standard_Short_Float then
5365 Fat_Pkg := RE_Attr_Short_Float;
5367 elsif Fat_Type = Standard_Float then
5368 Fat_Pkg := RE_Attr_Float;
5370 elsif Fat_Type = Standard_Long_Float then
5371 Fat_Pkg := RE_Attr_Long_Float;
5373 elsif Fat_Type = Standard_Long_Long_Float then
5374 Fat_Pkg := RE_Attr_Long_Long_Float;
5376 -- Universal real (which is its own root type) is treated as being
5377 -- equivalent to Standard.Long_Long_Float, since it is defined to
5378 -- have the same precision as the longest Float type.
5380 elsif Fat_Type = Universal_Real then
5381 Fat_Type := Standard_Long_Long_Float;
5382 Fat_Pkg := RE_Attr_Long_Long_Float;
5385 raise Program_Error;
5390 ----------------------------
5391 -- Find_Stream_Subprogram --
5392 ----------------------------
5394 function Find_Stream_Subprogram
5396 Nam : TSS_Name_Type) return Entity_Id
5398 Base_Typ : constant Entity_Id := Base_Type (Typ);
5399 Ent : constant Entity_Id := TSS (Typ, Nam);
5402 if Present (Ent) then
5406 -- Stream attributes for strings are expanded into library calls. The
5407 -- following checks are disabled when the run-time is not available or
5408 -- when compiling predefined types due to bootstrap issues. As a result,
5409 -- the compiler will generate in-place stream routines for string types
5410 -- that appear in GNAT's library, but will generate calls via rtsfind
5411 -- to library routines for user code.
5412 -- ??? For now, disable this code for JVM, since this generates a
5413 -- VerifyError exception at run-time on e.g. c330001.
5414 -- This is disabled for AAMP, to avoid making dependences on files not
5415 -- supported in the AAMP library (such as s-fileio.adb).
5417 if VM_Target /= JVM_Target
5418 and then not AAMP_On_Target
5420 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5422 -- String as defined in package Ada
5424 if Base_Typ = Standard_String then
5425 if Restriction_Active (No_Stream_Optimizations) then
5426 if Nam = TSS_Stream_Input then
5427 return RTE (RE_String_Input);
5429 elsif Nam = TSS_Stream_Output then
5430 return RTE (RE_String_Output);
5432 elsif Nam = TSS_Stream_Read then
5433 return RTE (RE_String_Read);
5435 else pragma Assert (Nam = TSS_Stream_Write);
5436 return RTE (RE_String_Write);
5440 if Nam = TSS_Stream_Input then
5441 return RTE (RE_String_Input_Blk_IO);
5443 elsif Nam = TSS_Stream_Output then
5444 return RTE (RE_String_Output_Blk_IO);
5446 elsif Nam = TSS_Stream_Read then
5447 return RTE (RE_String_Read_Blk_IO);
5449 else pragma Assert (Nam = TSS_Stream_Write);
5450 return RTE (RE_String_Write_Blk_IO);
5454 -- Wide_String as defined in package Ada
5456 elsif Base_Typ = Standard_Wide_String then
5457 if Restriction_Active (No_Stream_Optimizations) then
5458 if Nam = TSS_Stream_Input then
5459 return RTE (RE_Wide_String_Input);
5461 elsif Nam = TSS_Stream_Output then
5462 return RTE (RE_Wide_String_Output);
5464 elsif Nam = TSS_Stream_Read then
5465 return RTE (RE_Wide_String_Read);
5467 else pragma Assert (Nam = TSS_Stream_Write);
5468 return RTE (RE_Wide_String_Write);
5472 if Nam = TSS_Stream_Input then
5473 return RTE (RE_Wide_String_Input_Blk_IO);
5475 elsif Nam = TSS_Stream_Output then
5476 return RTE (RE_Wide_String_Output_Blk_IO);
5478 elsif Nam = TSS_Stream_Read then
5479 return RTE (RE_Wide_String_Read_Blk_IO);
5481 else pragma Assert (Nam = TSS_Stream_Write);
5482 return RTE (RE_Wide_String_Write_Blk_IO);
5486 -- Wide_Wide_String as defined in package Ada
5488 elsif Base_Typ = Standard_Wide_Wide_String then
5489 if Restriction_Active (No_Stream_Optimizations) then
5490 if Nam = TSS_Stream_Input then
5491 return RTE (RE_Wide_Wide_String_Input);
5493 elsif Nam = TSS_Stream_Output then
5494 return RTE (RE_Wide_Wide_String_Output);
5496 elsif Nam = TSS_Stream_Read then
5497 return RTE (RE_Wide_Wide_String_Read);
5499 else pragma Assert (Nam = TSS_Stream_Write);
5500 return RTE (RE_Wide_Wide_String_Write);
5504 if Nam = TSS_Stream_Input then
5505 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
5507 elsif Nam = TSS_Stream_Output then
5508 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
5510 elsif Nam = TSS_Stream_Read then
5511 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
5513 else pragma Assert (Nam = TSS_Stream_Write);
5514 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
5520 if Is_Tagged_Type (Typ)
5521 and then Is_Derived_Type (Typ)
5523 return Find_Prim_Op (Typ, Nam);
5525 return Find_Inherited_TSS (Typ, Nam);
5527 end Find_Stream_Subprogram;
5529 -----------------------
5530 -- Get_Index_Subtype --
5531 -----------------------
5533 function Get_Index_Subtype (N : Node_Id) return Node_Id is
5534 P_Type : Entity_Id := Etype (Prefix (N));
5539 if Is_Access_Type (P_Type) then
5540 P_Type := Designated_Type (P_Type);
5543 if No (Expressions (N)) then
5546 J := UI_To_Int (Expr_Value (First (Expressions (N))));
5549 Indx := First_Index (P_Type);
5555 return Etype (Indx);
5556 end Get_Index_Subtype;
5558 -------------------------------
5559 -- Get_Stream_Convert_Pragma --
5560 -------------------------------
5562 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
5567 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
5568 -- that a stream convert pragma for a tagged type is not inherited from
5569 -- its parent. Probably what is wrong here is that it is basically
5570 -- incorrect to consider a stream convert pragma to be a representation
5571 -- pragma at all ???
5573 N := First_Rep_Item (Implementation_Base_Type (T));
5574 while Present (N) loop
5575 if Nkind (N) = N_Pragma
5576 and then Pragma_Name (N) = Name_Stream_Convert
5578 -- For tagged types this pragma is not inherited, so we
5579 -- must verify that it is defined for the given type and
5583 Entity (Expression (First (Pragma_Argument_Associations (N))));
5585 if not Is_Tagged_Type (T)
5587 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
5597 end Get_Stream_Convert_Pragma;
5599 ---------------------------------
5600 -- Is_Constrained_Packed_Array --
5601 ---------------------------------
5603 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
5604 Arr : Entity_Id := Typ;
5607 if Is_Access_Type (Arr) then
5608 Arr := Designated_Type (Arr);
5611 return Is_Array_Type (Arr)
5612 and then Is_Constrained (Arr)
5613 and then Present (Packed_Array_Type (Arr));
5614 end Is_Constrained_Packed_Array;
5616 ----------------------------------------
5617 -- Is_Inline_Floating_Point_Attribute --
5618 ----------------------------------------
5620 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
5621 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
5624 if Nkind (Parent (N)) /= N_Type_Conversion
5625 or else not Is_Integer_Type (Etype (Parent (N)))
5630 -- Should also support 'Machine_Rounding and 'Unbiased_Rounding, but
5631 -- required back end support has not been implemented yet ???
5633 return Id = Attribute_Truncation;
5634 end Is_Inline_Floating_Point_Attribute;
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