1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- You should have received a copy of the GNU General Public License along --
19 -- with this program; see file COPYING3. If not see --
20 -- <http://www.gnu.org/licenses/>. --
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_Aux; use Sem_Aux;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch7; use Sem_Ch7;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Eval; use Sem_Eval;
61 with Sem_Res; use Sem_Res;
62 with Sem_Util; use Sem_Util;
63 with Sinfo; use Sinfo;
64 with Snames; use Snames;
65 with Stand; use Stand;
66 with Stringt; use Stringt;
67 with Targparm; use Targparm;
68 with Tbuild; use Tbuild;
69 with Ttypes; use Ttypes;
70 with Uintp; use Uintp;
71 with Uname; use Uname;
72 with Validsw; use Validsw;
74 package body Exp_Attr is
76 -----------------------
77 -- Local Subprograms --
78 -----------------------
80 procedure Compile_Stream_Body_In_Scope
85 -- The body for a stream subprogram may be generated outside of the scope
86 -- of the type. If the type is fully private, it may depend on the full
87 -- view of other types (e.g. indexes) that are currently private as well.
88 -- We install the declarations of the package in which the type is declared
89 -- before compiling the body in what is its proper environment. The Check
90 -- parameter indicates if checks are to be suppressed for the stream body.
91 -- We suppress checks for array/record reads, since the rule is that these
92 -- are like assignments, out of range values due to uninitialized storage,
93 -- or other invalid values do NOT cause a Constraint_Error to be raised.
95 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 Full_Base (T : Entity_Id) return Entity_Id;
159 -- The stream functions need to examine the underlying representation of
160 -- composite types. In some cases T may be non-private but its base type
161 -- is, in which case the function returns the corresponding full view.
163 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id;
164 -- Given a type, find a corresponding stream convert pragma that applies to
165 -- the implementation base type of this type (Typ). If found, return the
166 -- pragma node, otherwise return Empty if no pragma is found.
168 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
169 -- Utility for array attributes, returns true on packed constrained
170 -- arrays, and on access to same.
172 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean;
173 -- Returns true iff the given node refers to an attribute call that
174 -- can be expanded directly by the back end and does not need front end
175 -- expansion. Typically used for rounding and truncation attributes that
176 -- appear directly inside a conversion to integer.
178 ----------------------------------
179 -- Compile_Stream_Body_In_Scope --
180 ----------------------------------
182 procedure Compile_Stream_Body_In_Scope
188 Installed : Boolean := False;
189 Scop : constant Entity_Id := Scope (Arr);
190 Curr : constant Entity_Id := Current_Scope;
194 and then not In_Open_Scopes (Scop)
195 and then Ekind (Scop) = E_Package
198 Install_Visible_Declarations (Scop);
199 Install_Private_Declarations (Scop);
202 -- The entities in the package are now visible, but the generated
203 -- stream entity must appear in the current scope (usually an
204 -- enclosing stream function) so that itypes all have their proper
211 Insert_Action (N, Decl);
213 Insert_Action (N, Decl, Suppress => All_Checks);
218 -- Remove extra copy of current scope, and package itself
221 End_Package_Scope (Scop);
223 end Compile_Stream_Body_In_Scope;
225 -----------------------------------
226 -- Expand_Access_To_Protected_Op --
227 -----------------------------------
229 procedure Expand_Access_To_Protected_Op
234 -- The value of the attribute_reference is a record containing two
235 -- fields: an access to the protected object, and an access to the
236 -- subprogram itself. The prefix is a selected component.
238 Loc : constant Source_Ptr := Sloc (N);
240 Btyp : constant Entity_Id := Base_Type (Typ);
243 E_T : constant Entity_Id := Equivalent_Type (Btyp);
244 Acc : constant Entity_Id :=
245 Etype (Next_Component (First_Component (E_T)));
249 function May_Be_External_Call return Boolean;
250 -- If the 'Access is to a local operation, but appears in a context
251 -- where it may lead to a call from outside the object, we must treat
252 -- this as an external call. Clearly we cannot tell without full
253 -- flow analysis, and a subsequent call that uses this 'Access may
254 -- lead to a bounded error (trying to seize locks twice, e.g.). For
255 -- now we treat 'Access as a potential external call if it is an actual
256 -- in a call to an outside subprogram.
258 --------------------------
259 -- May_Be_External_Call --
260 --------------------------
262 function May_Be_External_Call return Boolean is
264 Par : Node_Id := Parent (N);
267 -- Account for the case where the Access attribute is part of a
268 -- named parameter association.
270 if Nkind (Par) = N_Parameter_Association then
274 if Nkind_In (Par, N_Procedure_Call_Statement, N_Function_Call)
275 and then Is_Entity_Name (Name (Par))
277 Subp := Entity (Name (Par));
278 return not In_Open_Scopes (Scope (Subp));
282 end May_Be_External_Call;
284 -- Start of processing for Expand_Access_To_Protected_Op
287 -- Within the body of the protected type, the prefix designates a local
288 -- operation, and the object is the first parameter of the corresponding
289 -- protected body of the current enclosing operation.
291 if Is_Entity_Name (Pref) then
292 if May_Be_External_Call then
294 New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc);
298 (Protected_Body_Subprogram (Entity (Pref)), Loc);
301 -- Don't traverse the scopes when the attribute occurs within an init
302 -- proc, because we directly use the _init formal of the init proc in
305 Curr := Current_Scope;
306 if not Is_Init_Proc (Curr) then
307 pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
309 while Scope (Curr) /= Scope (Entity (Pref)) loop
310 Curr := Scope (Curr);
314 -- In case of protected entries the first formal of its Protected_
315 -- Body_Subprogram is the address of the object.
317 if Ekind (Curr) = E_Entry then
321 (Protected_Body_Subprogram (Curr)), Loc);
323 -- If the current scope is an init proc, then use the address of the
324 -- _init formal as the object reference.
326 elsif Is_Init_Proc (Curr) then
328 Make_Attribute_Reference (Loc,
329 Prefix => New_Occurrence_Of (First_Formal (Curr), Loc),
330 Attribute_Name => Name_Address);
332 -- In case of protected subprograms the first formal of its
333 -- Protected_Body_Subprogram is the object and we get its address.
337 Make_Attribute_Reference (Loc,
341 (Protected_Body_Subprogram (Curr)), Loc),
342 Attribute_Name => Name_Address);
345 -- Case where the prefix is not an entity name. Find the
346 -- version of the protected operation to be called from
347 -- outside the protected object.
353 (Entity (Selector_Name (Pref))), Loc);
356 Make_Attribute_Reference (Loc,
357 Prefix => Relocate_Node (Prefix (Pref)),
358 Attribute_Name => Name_Address);
362 Make_Attribute_Reference (Loc,
364 Attribute_Name => Name_Access);
366 -- We set the type of the access reference to the already generated
367 -- access_to_subprogram type, and declare the reference analyzed, to
368 -- prevent further expansion when the enclosing aggregate is analyzed.
370 Set_Etype (Sub_Ref, Acc);
371 Set_Analyzed (Sub_Ref);
375 Expressions => New_List (Obj_Ref, Sub_Ref));
377 -- Sub_Ref has been marked as analyzed, but we still need to make sure
378 -- Sub is correctly frozen.
380 Freeze_Before (N, Entity (Sub));
383 Analyze_And_Resolve (N, E_T);
385 -- For subsequent analysis, the node must retain its type. The backend
386 -- will replace it with the equivalent type where needed.
389 end Expand_Access_To_Protected_Op;
391 --------------------------
392 -- Expand_Fpt_Attribute --
393 --------------------------
395 procedure Expand_Fpt_Attribute
401 Loc : constant Source_Ptr := Sloc (N);
402 Typ : constant Entity_Id := Etype (N);
406 -- The function name is the selected component Attr_xxx.yyy where
407 -- Attr_xxx is the package name, and yyy is the argument Nam.
409 -- Note: it would be more usual to have separate RE entries for each
410 -- of the entities in the Fat packages, but first they have identical
411 -- names (so we would have to have lots of renaming declarations to
412 -- meet the normal RE rule of separate names for all runtime entities),
413 -- and second there would be an awful lot of them!
416 Make_Selected_Component (Loc,
417 Prefix => New_Reference_To (RTE (Pkg), Loc),
418 Selector_Name => Make_Identifier (Loc, Nam));
420 -- The generated call is given the provided set of parameters, and then
421 -- wrapped in a conversion which converts the result to the target type
422 -- We use the base type as the target because a range check may be
426 Unchecked_Convert_To (Base_Type (Etype (N)),
427 Make_Function_Call (Loc,
429 Parameter_Associations => Args)));
431 Analyze_And_Resolve (N, Typ);
432 end Expand_Fpt_Attribute;
434 ----------------------------
435 -- Expand_Fpt_Attribute_R --
436 ----------------------------
438 -- The single argument is converted to its root type to call the
439 -- appropriate runtime function, with the actual call being built
440 -- by Expand_Fpt_Attribute
442 procedure Expand_Fpt_Attribute_R (N : Node_Id) is
443 E1 : constant Node_Id := First (Expressions (N));
447 Find_Fat_Info (Etype (E1), Ftp, Pkg);
449 (N, Pkg, Attribute_Name (N),
450 New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1))));
451 end Expand_Fpt_Attribute_R;
453 -----------------------------
454 -- Expand_Fpt_Attribute_RI --
455 -----------------------------
457 -- The first argument is converted to its root type and the second
458 -- argument is converted to standard long long integer to call the
459 -- appropriate runtime function, with the actual call being built
460 -- by Expand_Fpt_Attribute
462 procedure Expand_Fpt_Attribute_RI (N : Node_Id) is
463 E1 : constant Node_Id := First (Expressions (N));
466 E2 : constant Node_Id := Next (E1);
468 Find_Fat_Info (Etype (E1), Ftp, Pkg);
470 (N, Pkg, Attribute_Name (N),
472 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
473 Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
474 end Expand_Fpt_Attribute_RI;
476 -----------------------------
477 -- Expand_Fpt_Attribute_RR --
478 -----------------------------
480 -- The two arguments are converted to their root types to call the
481 -- appropriate runtime function, with the actual call being built
482 -- by Expand_Fpt_Attribute
484 procedure Expand_Fpt_Attribute_RR (N : Node_Id) is
485 E1 : constant Node_Id := First (Expressions (N));
488 E2 : constant Node_Id := Next (E1);
490 Find_Fat_Info (Etype (E1), Ftp, Pkg);
492 (N, Pkg, Attribute_Name (N),
494 Unchecked_Convert_To (Ftp, Relocate_Node (E1)),
495 Unchecked_Convert_To (Ftp, Relocate_Node (E2))));
496 end Expand_Fpt_Attribute_RR;
498 ----------------------------------
499 -- Expand_N_Attribute_Reference --
500 ----------------------------------
502 procedure Expand_N_Attribute_Reference (N : Node_Id) is
503 Loc : constant Source_Ptr := Sloc (N);
504 Typ : constant Entity_Id := Etype (N);
505 Btyp : constant Entity_Id := Base_Type (Typ);
506 Pref : constant Node_Id := Prefix (N);
507 Ptyp : constant Entity_Id := Etype (Pref);
508 Exprs : constant List_Id := Expressions (N);
509 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
511 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
512 -- Rewrites a stream attribute for Read, Write or Output with the
513 -- procedure call. Pname is the entity for the procedure to call.
515 ------------------------------
516 -- Rewrite_Stream_Proc_Call --
517 ------------------------------
519 procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
520 Item : constant Node_Id := Next (First (Exprs));
521 Formal : constant Entity_Id := Next_Formal (First_Formal (Pname));
522 Formal_Typ : constant Entity_Id := Etype (Formal);
523 Is_Written : constant Boolean := (Ekind (Formal) /= E_In_Parameter);
526 -- The expansion depends on Item, the second actual, which is
527 -- the object being streamed in or out.
529 -- If the item is a component of a packed array type, and
530 -- a conversion is needed on exit, we introduce a temporary to
531 -- hold the value, because otherwise the packed reference will
532 -- not be properly expanded.
534 if Nkind (Item) = N_Indexed_Component
535 and then Is_Packed (Base_Type (Etype (Prefix (Item))))
536 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
540 Temp : constant Entity_Id := Make_Temporary (Loc, 'V');
546 Make_Object_Declaration (Loc,
547 Defining_Identifier => Temp,
549 New_Occurrence_Of (Formal_Typ, Loc));
550 Set_Etype (Temp, Formal_Typ);
553 Make_Assignment_Statement (Loc,
554 Name => New_Copy_Tree (Item),
557 (Etype (Item), New_Occurrence_Of (Temp, Loc)));
559 Rewrite (Item, New_Occurrence_Of (Temp, Loc));
563 Make_Procedure_Call_Statement (Loc,
564 Name => New_Occurrence_Of (Pname, Loc),
565 Parameter_Associations => Exprs),
568 Rewrite (N, Make_Null_Statement (Loc));
573 -- For the class-wide dispatching cases, and for cases in which
574 -- the base type of the second argument matches the base type of
575 -- the corresponding formal parameter (that is to say the stream
576 -- operation is not inherited), we are all set, and can use the
577 -- argument unchanged.
579 -- For all other cases we do an unchecked conversion of the second
580 -- parameter to the type of the formal of the procedure we are
581 -- calling. This deals with the private type cases, and with going
582 -- to the root type as required in elementary type case.
584 if not Is_Class_Wide_Type (Entity (Pref))
585 and then not Is_Class_Wide_Type (Etype (Item))
586 and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
589 Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
591 -- For untagged derived types set Assignment_OK, to prevent
592 -- copies from being created when the unchecked conversion
593 -- is expanded (which would happen in Remove_Side_Effects
594 -- if Expand_N_Unchecked_Conversion were allowed to call
595 -- Force_Evaluation). The copy could violate Ada semantics
596 -- in cases such as an actual that is an out parameter.
597 -- Note that this approach is also used in exp_ch7 for calls
598 -- to controlled type operations to prevent problems with
599 -- actuals wrapped in unchecked conversions.
601 if Is_Untagged_Derivation (Etype (Expression (Item))) then
602 Set_Assignment_OK (Item);
606 -- The stream operation to call maybe a renaming created by
607 -- an attribute definition clause, and may not be frozen yet.
608 -- Ensure that it has the necessary extra formals.
610 if not Is_Frozen (Pname) then
611 Create_Extra_Formals (Pname);
614 -- And now rewrite the call
617 Make_Procedure_Call_Statement (Loc,
618 Name => New_Occurrence_Of (Pname, Loc),
619 Parameter_Associations => Exprs));
622 end Rewrite_Stream_Proc_Call;
624 -- Start of processing for Expand_N_Attribute_Reference
627 -- Do required validity checking, if enabled. Do not apply check to
628 -- output parameters of an Asm instruction, since the value of this
629 -- is not set till after the attribute has been elaborated, and do
630 -- not apply the check to the arguments of a 'Read or 'Input attribute
631 -- reference since the scalar argument is an OUT scalar.
633 if Validity_Checks_On and then Validity_Check_Operands
634 and then Id /= Attribute_Asm_Output
635 and then Id /= Attribute_Read
636 and then Id /= Attribute_Input
641 Expr := First (Expressions (N));
642 while Present (Expr) loop
649 -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in-
650 -- place function, then a temporary return object needs to be created
651 -- and access to it must be passed to the function. Currently we limit
652 -- such functions to those with inherently limited result subtypes, but
653 -- eventually we plan to expand the functions that are treated as
654 -- build-in-place to include other composite result types.
656 if Ada_Version >= Ada_2005
657 and then Is_Build_In_Place_Function_Call (Pref)
659 Make_Build_In_Place_Call_In_Anonymous_Context (Pref);
662 -- If prefix is a protected type name, this is a reference to the
663 -- current instance of the type. For a component definition, nothing
664 -- to do (expansion will occur in the init proc). In other contexts,
665 -- rewrite into reference to current instance.
667 if Is_Protected_Self_Reference (Pref)
669 (Nkind_In (Parent (N), N_Index_Or_Discriminant_Constraint,
670 N_Discriminant_Association)
671 and then Nkind (Parent (Parent (Parent (Parent (N))))) =
672 N_Component_Definition)
674 Rewrite (Pref, Concurrent_Ref (Pref));
678 -- Remaining processing depends on specific attribute
686 when Attribute_Access |
687 Attribute_Unchecked_Access |
688 Attribute_Unrestricted_Access =>
690 Access_Cases : declare
691 Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
692 Btyp_DDT : Entity_Id;
694 function Enclosing_Object (N : Node_Id) return Node_Id;
695 -- If N denotes a compound name (selected component, indexed
696 -- component, or slice), returns the name of the outermost such
697 -- enclosing object. Otherwise returns N. If the object is a
698 -- renaming, then the renamed object is returned.
700 ----------------------
701 -- Enclosing_Object --
702 ----------------------
704 function Enclosing_Object (N : Node_Id) return Node_Id is
709 while Nkind_In (Obj_Name, N_Selected_Component,
713 Obj_Name := Prefix (Obj_Name);
716 return Get_Referenced_Object (Obj_Name);
717 end Enclosing_Object;
719 -- Local declarations
721 Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object);
723 -- Start of processing for Access_Cases
726 Btyp_DDT := Designated_Type (Btyp);
728 -- Handle designated types that come from the limited view
730 if Ekind (Btyp_DDT) = E_Incomplete_Type
731 and then From_With_Type (Btyp_DDT)
732 and then Present (Non_Limited_View (Btyp_DDT))
734 Btyp_DDT := Non_Limited_View (Btyp_DDT);
736 elsif Is_Class_Wide_Type (Btyp_DDT)
737 and then Ekind (Etype (Btyp_DDT)) = E_Incomplete_Type
738 and then From_With_Type (Etype (Btyp_DDT))
739 and then Present (Non_Limited_View (Etype (Btyp_DDT)))
740 and then Present (Class_Wide_Type
741 (Non_Limited_View (Etype (Btyp_DDT))))
744 Class_Wide_Type (Non_Limited_View (Etype (Btyp_DDT)));
747 -- In order to improve the text of error messages, the designated
748 -- type of access-to-subprogram itypes is set by the semantics as
749 -- the associated subprogram entity (see sem_attr). Now we replace
750 -- such node with the proper E_Subprogram_Type itype.
752 if Id = Attribute_Unrestricted_Access
753 and then Is_Subprogram (Directly_Designated_Type (Typ))
755 -- The following conditions ensure that this special management
756 -- is done only for "Address!(Prim'Unrestricted_Access)" nodes.
757 -- At this stage other cases in which the designated type is
758 -- still a subprogram (instead of an E_Subprogram_Type) are
759 -- wrong because the semantics must have overridden the type of
760 -- the node with the type imposed by the context.
762 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
763 and then Etype (Parent (N)) = RTE (RE_Prim_Ptr)
765 Set_Etype (N, RTE (RE_Prim_Ptr));
769 Subp : constant Entity_Id :=
770 Directly_Designated_Type (Typ);
772 Extra : Entity_Id := Empty;
773 New_Formal : Entity_Id;
774 Old_Formal : Entity_Id := First_Formal (Subp);
775 Subp_Typ : Entity_Id;
778 Subp_Typ := Create_Itype (E_Subprogram_Type, N);
779 Set_Etype (Subp_Typ, Etype (Subp));
780 Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp));
782 if Present (Old_Formal) then
783 New_Formal := New_Copy (Old_Formal);
784 Set_First_Entity (Subp_Typ, New_Formal);
787 Set_Scope (New_Formal, Subp_Typ);
788 Etyp := Etype (New_Formal);
790 -- Handle itypes. There is no need to duplicate
791 -- here the itypes associated with record types
792 -- (i.e the implicit full view of private types).
795 and then Ekind (Base_Type (Etyp)) /= E_Record_Type
797 Extra := New_Copy (Etyp);
798 Set_Parent (Extra, New_Formal);
799 Set_Etype (New_Formal, Extra);
800 Set_Scope (Extra, Subp_Typ);
804 Next_Formal (Old_Formal);
805 exit when No (Old_Formal);
807 Set_Next_Entity (New_Formal,
808 New_Copy (Old_Formal));
809 Next_Entity (New_Formal);
812 Set_Next_Entity (New_Formal, Empty);
813 Set_Last_Entity (Subp_Typ, Extra);
816 -- Now that the explicit formals have been duplicated,
817 -- any extra formals needed by the subprogram must be
820 if Present (Extra) then
821 Set_Extra_Formal (Extra, Empty);
824 Create_Extra_Formals (Subp_Typ);
825 Set_Directly_Designated_Type (Typ, Subp_Typ);
830 if Is_Access_Protected_Subprogram_Type (Btyp) then
831 Expand_Access_To_Protected_Op (N, Pref, Typ);
833 -- If prefix is a type name, this is a reference to the current
834 -- instance of the type, within its initialization procedure.
836 elsif Is_Entity_Name (Pref)
837 and then Is_Type (Entity (Pref))
844 -- If the current instance name denotes a task type, then
845 -- the access attribute is rewritten to be the name of the
846 -- "_task" parameter associated with the task type's task
847 -- procedure. An unchecked conversion is applied to ensure
848 -- a type match in cases of expander-generated calls (e.g.
851 if Is_Task_Type (Entity (Pref)) then
853 First_Entity (Get_Task_Body_Procedure (Entity (Pref)));
854 while Present (Formal) loop
855 exit when Chars (Formal) = Name_uTask;
856 Next_Entity (Formal);
859 pragma Assert (Present (Formal));
862 Unchecked_Convert_To (Typ,
863 New_Occurrence_Of (Formal, Loc)));
866 -- The expression must appear in a default expression,
867 -- (which in the initialization procedure is the
868 -- right-hand side of an assignment), and not in a
869 -- discriminant constraint.
873 while Present (Par) loop
874 exit when Nkind (Par) = N_Assignment_Statement;
876 if Nkind (Par) = N_Component_Declaration then
883 if Present (Par) then
885 Make_Attribute_Reference (Loc,
886 Prefix => Make_Identifier (Loc, Name_uInit),
887 Attribute_Name => Attribute_Name (N)));
889 Analyze_And_Resolve (N, Typ);
894 -- If the prefix of an Access attribute is a dereference of an
895 -- access parameter (or a renaming of such a dereference, or a
896 -- subcomponent of such a dereference) and the context is a
897 -- general access type (including the type of an object or
898 -- component with an access_definition, but not the anonymous
899 -- type of an access parameter or access discriminant), then
900 -- apply an accessibility check to the access parameter. We used
901 -- to rewrite the access parameter as a type conversion, but that
902 -- could only be done if the immediate prefix of the Access
903 -- attribute was the dereference, and didn't handle cases where
904 -- the attribute is applied to a subcomponent of the dereference,
905 -- since there's generally no available, appropriate access type
906 -- to convert to in that case. The attribute is passed as the
907 -- point to insert the check, because the access parameter may
908 -- come from a renaming, possibly in a different scope, and the
909 -- check must be associated with the attribute itself.
911 elsif Id = Attribute_Access
912 and then Nkind (Enc_Object) = N_Explicit_Dereference
913 and then Is_Entity_Name (Prefix (Enc_Object))
914 and then (Ekind (Btyp) = E_General_Access_Type
915 or else Is_Local_Anonymous_Access (Btyp))
916 and then Ekind (Entity (Prefix (Enc_Object))) in Formal_Kind
917 and then Ekind (Etype (Entity (Prefix (Enc_Object))))
918 = E_Anonymous_Access_Type
919 and then Present (Extra_Accessibility
920 (Entity (Prefix (Enc_Object))))
922 Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N);
924 -- Ada 2005 (AI-251): If the designated type is an interface we
925 -- add an implicit conversion to force the displacement of the
926 -- pointer to reference the secondary dispatch table.
928 elsif Is_Interface (Btyp_DDT)
929 and then (Comes_From_Source (N)
930 or else Comes_From_Source (Ref_Object)
931 or else (Nkind (Ref_Object) in N_Has_Chars
932 and then Chars (Ref_Object) = Name_uInit))
934 if Nkind (Ref_Object) /= N_Explicit_Dereference then
936 -- No implicit conversion required if types match, or if
937 -- the prefix is the class_wide_type of the interface. In
938 -- either case passing an object of the interface type has
939 -- already set the pointer correctly.
941 if Btyp_DDT = Etype (Ref_Object)
942 or else (Is_Class_Wide_Type (Etype (Ref_Object))
944 Class_Wide_Type (Btyp_DDT) = Etype (Ref_Object))
950 Convert_To (Btyp_DDT,
951 New_Copy_Tree (Prefix (N))));
953 Analyze_And_Resolve (Prefix (N), Btyp_DDT);
956 -- When the object is an explicit dereference, convert the
957 -- dereference's prefix.
961 Obj_DDT : constant Entity_Id :=
963 (Directly_Designated_Type
964 (Etype (Prefix (Ref_Object))));
966 -- No implicit conversion required if designated types
969 if Obj_DDT /= Btyp_DDT
970 and then not (Is_Class_Wide_Type (Obj_DDT)
971 and then Etype (Obj_DDT) = Btyp_DDT)
975 New_Copy_Tree (Prefix (Ref_Object))));
976 Analyze_And_Resolve (N, Typ);
987 -- Transforms 'Adjacent into a call to the floating-point attribute
988 -- function Adjacent in Fat_xxx (where xxx is the root type)
990 when Attribute_Adjacent =>
991 Expand_Fpt_Attribute_RR (N);
997 when Attribute_Address => Address : declare
998 Task_Proc : Entity_Id;
1001 -- If the prefix is a task or a task type, the useful address is that
1002 -- of the procedure for the task body, i.e. the actual program unit.
1003 -- We replace the original entity with that of the procedure.
1005 if Is_Entity_Name (Pref)
1006 and then Is_Task_Type (Entity (Pref))
1008 Task_Proc := Next_Entity (Root_Type (Ptyp));
1010 while Present (Task_Proc) loop
1011 exit when Ekind (Task_Proc) = E_Procedure
1012 and then Etype (First_Formal (Task_Proc)) =
1013 Corresponding_Record_Type (Ptyp);
1014 Next_Entity (Task_Proc);
1017 if Present (Task_Proc) then
1018 Set_Entity (Pref, Task_Proc);
1019 Set_Etype (Pref, Etype (Task_Proc));
1022 -- Similarly, the address of a protected operation is the address
1023 -- of the corresponding protected body, regardless of the protected
1024 -- object from which it is selected.
1026 elsif Nkind (Pref) = N_Selected_Component
1027 and then Is_Subprogram (Entity (Selector_Name (Pref)))
1028 and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref))))
1032 External_Subprogram (Entity (Selector_Name (Pref))), Loc));
1034 elsif Nkind (Pref) = N_Explicit_Dereference
1035 and then Ekind (Ptyp) = E_Subprogram_Type
1036 and then Convention (Ptyp) = Convention_Protected
1038 -- The prefix is be a dereference of an access_to_protected_
1039 -- subprogram. The desired address is the second component of
1040 -- the record that represents the access.
1043 Addr : constant Entity_Id := Etype (N);
1044 Ptr : constant Node_Id := Prefix (Pref);
1045 T : constant Entity_Id :=
1046 Equivalent_Type (Base_Type (Etype (Ptr)));
1050 Unchecked_Convert_To (Addr,
1051 Make_Selected_Component (Loc,
1052 Prefix => Unchecked_Convert_To (T, Ptr),
1053 Selector_Name => New_Occurrence_Of (
1054 Next_Entity (First_Entity (T)), Loc))));
1056 Analyze_And_Resolve (N, Addr);
1059 -- Ada 2005 (AI-251): Class-wide interface objects are always
1060 -- "displaced" to reference the tag associated with the interface
1061 -- type. In order to obtain the real address of such objects we
1062 -- generate a call to a run-time subprogram that returns the base
1063 -- address of the object.
1065 -- This processing is not needed in the VM case, where dispatching
1066 -- issues are taken care of by the virtual machine.
1068 elsif Is_Class_Wide_Type (Ptyp)
1069 and then Is_Interface (Ptyp)
1070 and then Tagged_Type_Expansion
1071 and then not (Nkind (Pref) in N_Has_Entity
1072 and then Is_Subprogram (Entity (Pref)))
1075 Make_Function_Call (Loc,
1076 Name => New_Reference_To (RTE (RE_Base_Address), Loc),
1077 Parameter_Associations => New_List (
1078 Relocate_Node (N))));
1083 -- Deal with packed array reference, other cases are handled by
1086 if Involves_Packed_Array_Reference (Pref) then
1087 Expand_Packed_Address_Reference (N);
1095 when Attribute_Alignment => Alignment : declare
1099 -- For class-wide types, X'Class'Alignment is transformed into a
1100 -- direct reference to the Alignment of the class type, so that the
1101 -- back end does not have to deal with the X'Class'Alignment
1104 if Is_Entity_Name (Pref)
1105 and then Is_Class_Wide_Type (Entity (Pref))
1107 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
1110 -- For x'Alignment applied to an object of a class wide type,
1111 -- transform X'Alignment into a call to the predefined primitive
1112 -- operation _Alignment applied to X.
1114 elsif Is_Class_Wide_Type (Ptyp) then
1116 -- No need to do anything else compiling under restriction
1117 -- No_Dispatching_Calls. During the semantic analysis we
1118 -- already notified such violation.
1120 if Restriction_Active (No_Dispatching_Calls) then
1125 Make_Function_Call (Loc,
1126 Name => New_Reference_To
1127 (Find_Prim_Op (Ptyp, Name_uAlignment), Loc),
1128 Parameter_Associations => New_List (Pref));
1130 if Typ /= Standard_Integer then
1132 -- The context is a specific integer type with which the
1133 -- original attribute was compatible. The function has a
1134 -- specific type as well, so to preserve the compatibility
1135 -- we must convert explicitly.
1137 New_Node := Convert_To (Typ, New_Node);
1140 Rewrite (N, New_Node);
1141 Analyze_And_Resolve (N, Typ);
1144 -- For all other cases, we just have to deal with the case of
1145 -- the fact that the result can be universal.
1148 Apply_Universal_Integer_Attribute_Checks (N);
1156 when Attribute_AST_Entry => AST_Entry : declare
1161 Entry_Ref : Node_Id;
1162 -- The reference to the entry or entry family
1165 -- The index expression for an entry family reference, or
1166 -- the Empty if Entry_Ref references a simple entry.
1169 if Nkind (Pref) = N_Indexed_Component then
1170 Entry_Ref := Prefix (Pref);
1171 Index := First (Expressions (Pref));
1177 -- Get expression for Task_Id and the entry entity
1179 if Nkind (Entry_Ref) = N_Selected_Component then
1181 Make_Attribute_Reference (Loc,
1182 Attribute_Name => Name_Identity,
1183 Prefix => Prefix (Entry_Ref));
1185 Ttyp := Etype (Prefix (Entry_Ref));
1186 Eent := Entity (Selector_Name (Entry_Ref));
1190 Make_Function_Call (Loc,
1191 Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc));
1193 Eent := Entity (Entry_Ref);
1195 -- We have to find the enclosing task to get the task type
1196 -- There must be one, since we already validated this earlier
1198 Ttyp := Current_Scope;
1199 while not Is_Task_Type (Ttyp) loop
1200 Ttyp := Scope (Ttyp);
1204 -- Now rewrite the attribute with a call to Create_AST_Handler
1207 Make_Function_Call (Loc,
1208 Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc),
1209 Parameter_Associations => New_List (
1211 Entry_Index_Expression (Loc, Eent, Index, Ttyp))));
1213 Analyze_And_Resolve (N, RTE (RE_AST_Handler));
1220 -- We compute this if a packed array reference was present, otherwise we
1221 -- leave the computation up to the back end.
1223 when Attribute_Bit =>
1224 if Involves_Packed_Array_Reference (Pref) then
1225 Expand_Packed_Bit_Reference (N);
1227 Apply_Universal_Integer_Attribute_Checks (N);
1234 -- We compute this if a component clause was present, otherwise we leave
1235 -- the computation up to the back end, since we don't know what layout
1238 -- Note that the attribute can apply to a naked record component
1239 -- in generated code (i.e. the prefix is an identifier that
1240 -- references the component or discriminant entity).
1242 when Attribute_Bit_Position => Bit_Position : declare
1246 if Nkind (Pref) = N_Identifier then
1247 CE := Entity (Pref);
1249 CE := Entity (Selector_Name (Pref));
1252 if Known_Static_Component_Bit_Offset (CE) then
1254 Make_Integer_Literal (Loc,
1255 Intval => Component_Bit_Offset (CE)));
1256 Analyze_And_Resolve (N, Typ);
1259 Apply_Universal_Integer_Attribute_Checks (N);
1267 -- A reference to P'Body_Version or P'Version is expanded to
1270 -- pragma Import (C, Vnn, "uuuuT");
1272 -- Get_Version_String (Vnn)
1274 -- where uuuu is the unit name (dots replaced by double underscore)
1275 -- and T is B for the cases of Body_Version, or Version applied to a
1276 -- subprogram acting as its own spec, and S for Version applied to a
1277 -- subprogram spec or package. This sequence of code references the
1278 -- unsigned constant created in the main program by the binder.
1280 -- A special exception occurs for Standard, where the string returned
1281 -- is a copy of the library string in gnatvsn.ads.
1283 when Attribute_Body_Version | Attribute_Version => Version : declare
1284 E : constant Entity_Id := Make_Temporary (Loc, 'V');
1289 -- If not library unit, get to containing library unit
1291 Pent := Entity (Pref);
1292 while Pent /= Standard_Standard
1293 and then Scope (Pent) /= Standard_Standard
1294 and then not Is_Child_Unit (Pent)
1296 Pent := Scope (Pent);
1299 -- Special case Standard and Standard.ASCII
1301 if Pent = Standard_Standard or else Pent = Standard_ASCII then
1303 Make_String_Literal (Loc,
1304 Strval => Verbose_Library_Version));
1309 -- Build required string constant
1311 Get_Name_String (Get_Unit_Name (Pent));
1314 for J in 1 .. Name_Len - 2 loop
1315 if Name_Buffer (J) = '.' then
1316 Store_String_Chars ("__");
1318 Store_String_Char (Get_Char_Code (Name_Buffer (J)));
1322 -- Case of subprogram acting as its own spec, always use body
1324 if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification
1325 and then Nkind (Parent (Declaration_Node (Pent))) =
1327 and then Acts_As_Spec (Parent (Declaration_Node (Pent)))
1329 Store_String_Chars ("B");
1331 -- Case of no body present, always use spec
1333 elsif not Unit_Requires_Body (Pent) then
1334 Store_String_Chars ("S");
1336 -- Otherwise use B for Body_Version, S for spec
1338 elsif Id = Attribute_Body_Version then
1339 Store_String_Chars ("B");
1341 Store_String_Chars ("S");
1345 Lib.Version_Referenced (S);
1347 -- Insert the object declaration
1349 Insert_Actions (N, New_List (
1350 Make_Object_Declaration (Loc,
1351 Defining_Identifier => E,
1352 Object_Definition =>
1353 New_Occurrence_Of (RTE (RE_Unsigned), Loc))));
1355 -- Set entity as imported with correct external name
1357 Set_Is_Imported (E);
1358 Set_Interface_Name (E, Make_String_Literal (Loc, S));
1360 -- Set entity as internal to ensure proper Sprint output of its
1361 -- implicit importation.
1363 Set_Is_Internal (E);
1365 -- And now rewrite original reference
1368 Make_Function_Call (Loc,
1369 Name => New_Reference_To (RTE (RE_Get_Version_String), Loc),
1370 Parameter_Associations => New_List (
1371 New_Occurrence_Of (E, Loc))));
1374 Analyze_And_Resolve (N, RTE (RE_Version_String));
1381 -- Transforms 'Ceiling into a call to the floating-point attribute
1382 -- function Ceiling in Fat_xxx (where xxx is the root type)
1384 when Attribute_Ceiling =>
1385 Expand_Fpt_Attribute_R (N);
1391 -- Transforms 'Callable attribute into a call to the Callable function
1393 when Attribute_Callable => Callable :
1395 -- We have an object of a task interface class-wide type as a prefix
1396 -- to Callable. Generate:
1397 -- callable (Task_Id (Pref._disp_get_task_id));
1399 if Ada_Version >= Ada_2005
1400 and then Ekind (Ptyp) = E_Class_Wide_Type
1401 and then Is_Interface (Ptyp)
1402 and then Is_Task_Interface (Ptyp)
1405 Make_Function_Call (Loc,
1407 New_Reference_To (RTE (RE_Callable), Loc),
1408 Parameter_Associations => New_List (
1409 Make_Unchecked_Type_Conversion (Loc,
1411 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
1413 Make_Selected_Component (Loc,
1415 New_Copy_Tree (Pref),
1417 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
1421 Build_Call_With_Task (Pref, RTE (RE_Callable)));
1424 Analyze_And_Resolve (N, Standard_Boolean);
1431 -- Transforms 'Caller attribute into a call to either the
1432 -- Task_Entry_Caller or the Protected_Entry_Caller function.
1434 when Attribute_Caller => Caller : declare
1435 Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id);
1436 Ent : constant Entity_Id := Entity (Pref);
1437 Conctype : constant Entity_Id := Scope (Ent);
1438 Nest_Depth : Integer := 0;
1445 if Is_Protected_Type (Conctype) then
1446 case Corresponding_Runtime_Package (Conctype) is
1447 when System_Tasking_Protected_Objects_Entries =>
1450 (RTE (RE_Protected_Entry_Caller), Loc);
1452 when System_Tasking_Protected_Objects_Single_Entry =>
1455 (RTE (RE_Protected_Single_Entry_Caller), Loc);
1458 raise Program_Error;
1462 Unchecked_Convert_To (Id_Kind,
1463 Make_Function_Call (Loc,
1465 Parameter_Associations => New_List (
1467 (Find_Protection_Object (Current_Scope), Loc)))));
1472 -- Determine the nesting depth of the E'Caller attribute, that
1473 -- is, how many accept statements are nested within the accept
1474 -- statement for E at the point of E'Caller. The runtime uses
1475 -- this depth to find the specified entry call.
1477 for J in reverse 0 .. Scope_Stack.Last loop
1478 S := Scope_Stack.Table (J).Entity;
1480 -- We should not reach the scope of the entry, as it should
1481 -- already have been checked in Sem_Attr that this attribute
1482 -- reference is within a matching accept statement.
1484 pragma Assert (S /= Conctype);
1489 elsif Is_Entry (S) then
1490 Nest_Depth := Nest_Depth + 1;
1495 Unchecked_Convert_To (Id_Kind,
1496 Make_Function_Call (Loc,
1498 New_Reference_To (RTE (RE_Task_Entry_Caller), Loc),
1499 Parameter_Associations => New_List (
1500 Make_Integer_Literal (Loc,
1501 Intval => Int (Nest_Depth))))));
1504 Analyze_And_Resolve (N, Id_Kind);
1511 -- Transforms 'Compose into a call to the floating-point attribute
1512 -- function Compose in Fat_xxx (where xxx is the root type)
1514 -- Note: we strictly should have special code here to deal with the
1515 -- case of absurdly negative arguments (less than Integer'First)
1516 -- which will return a (signed) zero value, but it hardly seems
1517 -- worth the effort. Absurdly large positive arguments will raise
1518 -- constraint error which is fine.
1520 when Attribute_Compose =>
1521 Expand_Fpt_Attribute_RI (N);
1527 when Attribute_Constrained => Constrained : declare
1528 Formal_Ent : constant Entity_Id := Param_Entity (Pref);
1530 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean;
1531 -- Ada 2005 (AI-363): Returns True if the object name Obj denotes a
1532 -- view of an aliased object whose subtype is constrained.
1534 ---------------------------------
1535 -- Is_Constrained_Aliased_View --
1536 ---------------------------------
1538 function Is_Constrained_Aliased_View (Obj : Node_Id) return Boolean is
1542 if Is_Entity_Name (Obj) then
1545 if Present (Renamed_Object (E)) then
1546 return Is_Constrained_Aliased_View (Renamed_Object (E));
1548 return Is_Aliased (E) and then Is_Constrained (Etype (E));
1552 return Is_Aliased_View (Obj)
1554 (Is_Constrained (Etype (Obj))
1555 or else (Nkind (Obj) = N_Explicit_Dereference
1557 not Has_Constrained_Partial_View
1558 (Base_Type (Etype (Obj)))));
1560 end Is_Constrained_Aliased_View;
1562 -- Start of processing for Constrained
1565 -- Reference to a parameter where the value is passed as an extra
1566 -- actual, corresponding to the extra formal referenced by the
1567 -- Extra_Constrained field of the corresponding formal. If this
1568 -- is an entry in-parameter, it is replaced by a constant renaming
1569 -- for which Extra_Constrained is never created.
1571 if Present (Formal_Ent)
1572 and then Ekind (Formal_Ent) /= E_Constant
1573 and then Present (Extra_Constrained (Formal_Ent))
1577 (Extra_Constrained (Formal_Ent), Sloc (N)));
1579 -- For variables with a Extra_Constrained field, we use the
1580 -- corresponding entity.
1582 elsif Nkind (Pref) = N_Identifier
1583 and then Ekind (Entity (Pref)) = E_Variable
1584 and then Present (Extra_Constrained (Entity (Pref)))
1588 (Extra_Constrained (Entity (Pref)), Sloc (N)));
1590 -- For all other entity names, we can tell at compile time
1592 elsif Is_Entity_Name (Pref) then
1594 Ent : constant Entity_Id := Entity (Pref);
1598 -- (RM J.4) obsolescent cases
1600 if Is_Type (Ent) then
1604 if Is_Private_Type (Ent) then
1605 Res := not Has_Discriminants (Ent)
1606 or else Is_Constrained (Ent);
1608 -- It not a private type, must be a generic actual type
1609 -- that corresponded to a private type. We know that this
1610 -- correspondence holds, since otherwise the reference
1611 -- within the generic template would have been illegal.
1614 if Is_Composite_Type (Underlying_Type (Ent)) then
1615 Res := Is_Constrained (Ent);
1621 -- If the prefix is not a variable or is aliased, then
1622 -- definitely true; if it's a formal parameter without an
1623 -- associated extra formal, then treat it as constrained.
1625 -- Ada 2005 (AI-363): An aliased prefix must be known to be
1626 -- constrained in order to set the attribute to True.
1628 elsif not Is_Variable (Pref)
1629 or else Present (Formal_Ent)
1630 or else (Ada_Version < Ada_2005
1631 and then Is_Aliased_View (Pref))
1632 or else (Ada_Version >= Ada_2005
1633 and then Is_Constrained_Aliased_View (Pref))
1637 -- Variable case, look at type to see if it is constrained.
1638 -- Note that the one case where this is not accurate (the
1639 -- procedure formal case), has been handled above.
1641 -- We use the Underlying_Type here (and below) in case the
1642 -- type is private without discriminants, but the full type
1643 -- has discriminants. This case is illegal, but we generate it
1644 -- internally for passing to the Extra_Constrained parameter.
1647 -- In Ada 2012, test for case of a limited tagged type, in
1648 -- which case the attribute is always required to return
1649 -- True. The underlying type is tested, to make sure we also
1650 -- return True for cases where there is an unconstrained
1651 -- object with an untagged limited partial view which has
1652 -- defaulted discriminants (such objects always produce a
1653 -- False in earlier versions of Ada). (Ada 2012: AI05-0214)
1655 Res := Is_Constrained (Underlying_Type (Etype (Ent)))
1657 (Ada_Version >= Ada_2012
1658 and then Is_Tagged_Type (Underlying_Type (Ptyp))
1659 and then Is_Limited_Type (Ptyp));
1662 Rewrite (N, New_Reference_To (Boolean_Literals (Res), Loc));
1665 -- Prefix is not an entity name. These are also cases where we can
1666 -- always tell at compile time by looking at the form and type of the
1667 -- prefix. If an explicit dereference of an object with constrained
1668 -- partial view, this is unconstrained (Ada 2005: AI95-0363). If the
1669 -- underlying type is a limited tagged type, then Constrained is
1670 -- required to always return True (Ada 2012: AI05-0214).
1676 not Is_Variable (Pref)
1678 (Nkind (Pref) = N_Explicit_Dereference
1680 not Has_Constrained_Partial_View (Base_Type (Ptyp)))
1681 or else Is_Constrained (Underlying_Type (Ptyp))
1682 or else (Ada_Version >= Ada_2012
1683 and then Is_Tagged_Type (Underlying_Type (Ptyp))
1684 and then Is_Limited_Type (Ptyp))),
1688 Analyze_And_Resolve (N, Standard_Boolean);
1695 -- Transforms 'Copy_Sign into a call to the floating-point attribute
1696 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
1698 when Attribute_Copy_Sign =>
1699 Expand_Fpt_Attribute_RR (N);
1705 -- Transforms 'Count attribute into a call to the Count function
1707 when Attribute_Count => Count : declare
1709 Conctyp : Entity_Id;
1711 Entry_Id : Entity_Id;
1716 -- If the prefix is a member of an entry family, retrieve both
1717 -- entry name and index. For a simple entry there is no index.
1719 if Nkind (Pref) = N_Indexed_Component then
1720 Entnam := Prefix (Pref);
1721 Index := First (Expressions (Pref));
1727 Entry_Id := Entity (Entnam);
1729 -- Find the concurrent type in which this attribute is referenced
1730 -- (there had better be one).
1732 Conctyp := Current_Scope;
1733 while not Is_Concurrent_Type (Conctyp) loop
1734 Conctyp := Scope (Conctyp);
1739 if Is_Protected_Type (Conctyp) then
1740 case Corresponding_Runtime_Package (Conctyp) is
1741 when System_Tasking_Protected_Objects_Entries =>
1742 Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
1745 Make_Function_Call (Loc,
1747 Parameter_Associations => New_List (
1749 (Find_Protection_Object (Current_Scope), Loc),
1750 Entry_Index_Expression
1751 (Loc, Entry_Id, Index, Scope (Entry_Id))));
1753 when System_Tasking_Protected_Objects_Single_Entry =>
1755 New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
1758 Make_Function_Call (Loc,
1760 Parameter_Associations => New_List (
1762 (Find_Protection_Object (Current_Scope), Loc)));
1765 raise Program_Error;
1772 Make_Function_Call (Loc,
1773 Name => New_Reference_To (RTE (RE_Task_Count), Loc),
1774 Parameter_Associations => New_List (
1775 Entry_Index_Expression (Loc,
1776 Entry_Id, Index, Scope (Entry_Id))));
1779 -- The call returns type Natural but the context is universal integer
1780 -- so any integer type is allowed. The attribute was already resolved
1781 -- so its Etype is the required result type. If the base type of the
1782 -- context type is other than Standard.Integer we put in a conversion
1783 -- to the required type. This can be a normal typed conversion since
1784 -- both input and output types of the conversion are integer types
1786 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
1787 Rewrite (N, Convert_To (Typ, Call));
1792 Analyze_And_Resolve (N, Typ);
1799 -- This processing is shared by Elab_Spec
1801 -- What we do is to insert the following declarations
1804 -- pragma Import (C, enn, "name___elabb/s");
1806 -- and then the Elab_Body/Spec attribute is replaced by a reference
1807 -- to this defining identifier.
1809 when Attribute_Elab_Body |
1810 Attribute_Elab_Spec =>
1813 Ent : constant Entity_Id := Make_Temporary (Loc, 'E');
1817 procedure Make_Elab_String (Nod : Node_Id);
1818 -- Given Nod, an identifier, or a selected component, put the
1819 -- image into the current string literal, with double underline
1820 -- between components.
1822 ----------------------
1823 -- Make_Elab_String --
1824 ----------------------
1826 procedure Make_Elab_String (Nod : Node_Id) is
1828 if Nkind (Nod) = N_Selected_Component then
1829 Make_Elab_String (Prefix (Nod));
1833 Store_String_Char ('$');
1835 Store_String_Char ('.');
1837 Store_String_Char ('_');
1838 Store_String_Char ('_');
1841 Get_Name_String (Chars (Selector_Name (Nod)));
1844 pragma Assert (Nkind (Nod) = N_Identifier);
1845 Get_Name_String (Chars (Nod));
1848 Store_String_Chars (Name_Buffer (1 .. Name_Len));
1849 end Make_Elab_String;
1851 -- Start of processing for Elab_Body/Elab_Spec
1854 -- First we need to prepare the string literal for the name of
1855 -- the elaboration routine to be referenced.
1858 Make_Elab_String (Pref);
1860 if VM_Target = No_VM then
1861 Store_String_Chars ("___elab");
1862 Lang := Make_Identifier (Loc, Name_C);
1864 Store_String_Chars ("._elab");
1865 Lang := Make_Identifier (Loc, Name_Ada);
1868 if Id = Attribute_Elab_Body then
1869 Store_String_Char ('b');
1871 Store_String_Char ('s');
1876 Insert_Actions (N, New_List (
1877 Make_Subprogram_Declaration (Loc,
1879 Make_Procedure_Specification (Loc,
1880 Defining_Unit_Name => Ent)),
1883 Chars => Name_Import,
1884 Pragma_Argument_Associations => New_List (
1885 Make_Pragma_Argument_Association (Loc, Expression => Lang),
1887 Make_Pragma_Argument_Association (Loc,
1888 Expression => Make_Identifier (Loc, Chars (Ent))),
1890 Make_Pragma_Argument_Association (Loc,
1891 Expression => Make_String_Literal (Loc, Str))))));
1893 Set_Entity (N, Ent);
1894 Rewrite (N, New_Occurrence_Of (Ent, Loc));
1901 -- Elaborated is always True for preelaborated units, predefined units,
1902 -- pure units and units which have Elaborate_Body pragmas. These units
1903 -- have no elaboration entity.
1905 -- Note: The Elaborated attribute is never passed to the back end
1907 when Attribute_Elaborated => Elaborated : declare
1908 Ent : constant Entity_Id := Entity (Pref);
1911 if Present (Elaboration_Entity (Ent)) then
1913 New_Occurrence_Of (Elaboration_Entity (Ent), Loc));
1915 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
1923 when Attribute_Enum_Rep => Enum_Rep :
1925 -- X'Enum_Rep (Y) expands to
1929 -- This is simply a direct conversion from the enumeration type to
1930 -- the target integer type, which is treated by the back end as a
1931 -- normal integer conversion, treating the enumeration type as an
1932 -- integer, which is exactly what we want! We set Conversion_OK to
1933 -- make sure that the analyzer does not complain about what otherwise
1934 -- might be an illegal conversion.
1936 if Is_Non_Empty_List (Exprs) then
1938 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
1940 -- X'Enum_Rep where X is an enumeration literal is replaced by
1941 -- the literal value.
1943 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
1945 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
1947 -- If this is a renaming of a literal, recover the representation
1950 elsif Ekind (Entity (Pref)) = E_Constant
1951 and then Present (Renamed_Object (Entity (Pref)))
1953 Ekind (Entity (Renamed_Object (Entity (Pref))))
1954 = E_Enumeration_Literal
1957 Make_Integer_Literal (Loc,
1958 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
1960 -- X'Enum_Rep where X is an object does a direct unchecked conversion
1961 -- of the object value, as described for the type case above.
1965 OK_Convert_To (Typ, Relocate_Node (Pref)));
1969 Analyze_And_Resolve (N, Typ);
1976 when Attribute_Enum_Val => Enum_Val : declare
1978 Btyp : constant Entity_Id := Base_Type (Ptyp);
1981 -- X'Enum_Val (Y) expands to
1983 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
1986 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
1989 Make_Raise_Constraint_Error (Loc,
1993 Make_Function_Call (Loc,
1995 New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
1996 Parameter_Associations => New_List (
1997 Relocate_Node (Duplicate_Subexpr (Expr)),
1998 New_Occurrence_Of (Standard_False, Loc))),
2000 Right_Opnd => Make_Integer_Literal (Loc, -1)),
2001 Reason => CE_Range_Check_Failed));
2004 Analyze_And_Resolve (N, Ptyp);
2011 -- Transforms 'Exponent into a call to the floating-point attribute
2012 -- function Exponent in Fat_xxx (where xxx is the root type)
2014 when Attribute_Exponent =>
2015 Expand_Fpt_Attribute_R (N);
2021 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
2023 when Attribute_External_Tag => External_Tag :
2026 Make_Function_Call (Loc,
2027 Name => New_Reference_To (RTE (RE_External_Tag), Loc),
2028 Parameter_Associations => New_List (
2029 Make_Attribute_Reference (Loc,
2030 Attribute_Name => Name_Tag,
2031 Prefix => Prefix (N)))));
2033 Analyze_And_Resolve (N, Standard_String);
2040 when Attribute_First =>
2042 -- If the prefix type is a constrained packed array type which
2043 -- already has a Packed_Array_Type representation defined, then
2044 -- replace this attribute with a direct reference to 'First of the
2045 -- appropriate index subtype (since otherwise the back end will try
2046 -- to give us the value of 'First for this implementation type).
2048 if Is_Constrained_Packed_Array (Ptyp) then
2050 Make_Attribute_Reference (Loc,
2051 Attribute_Name => Name_First,
2052 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2053 Analyze_And_Resolve (N, Typ);
2055 elsif Is_Access_Type (Ptyp) then
2056 Apply_Access_Check (N);
2063 -- Compute this if component clause was present, otherwise we leave the
2064 -- computation to be completed in the back-end, since we don't know what
2065 -- layout will be chosen.
2067 when Attribute_First_Bit => First_Bit : declare
2068 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2071 if Known_Static_Component_Bit_Offset (CE) then
2073 Make_Integer_Literal (Loc,
2074 Component_Bit_Offset (CE) mod System_Storage_Unit));
2076 Analyze_And_Resolve (N, Typ);
2079 Apply_Universal_Integer_Attribute_Checks (N);
2089 -- fixtype'Fixed_Value (integer-value)
2093 -- fixtype(integer-value)
2095 -- We do all the required analysis of the conversion here, because we do
2096 -- not want this to go through the fixed-point conversion circuits. Note
2097 -- that the back end always treats fixed-point as equivalent to the
2098 -- corresponding integer type anyway.
2100 when Attribute_Fixed_Value => Fixed_Value :
2103 Make_Type_Conversion (Loc,
2104 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2105 Expression => Relocate_Node (First (Exprs))));
2106 Set_Etype (N, Entity (Pref));
2109 -- Note: it might appear that a properly analyzed unchecked conversion
2110 -- would be just fine here, but that's not the case, since the full
2111 -- range checks performed by the following call are critical!
2113 Apply_Type_Conversion_Checks (N);
2120 -- Transforms 'Floor into a call to the floating-point attribute
2121 -- function Floor in Fat_xxx (where xxx is the root type)
2123 when Attribute_Floor =>
2124 Expand_Fpt_Attribute_R (N);
2130 -- For the fixed-point type Typ:
2136 -- Result_Type (System.Fore (Universal_Real (Type'First)),
2137 -- Universal_Real (Type'Last))
2139 -- Note that we know that the type is a non-static subtype, or Fore
2140 -- would have itself been computed dynamically in Eval_Attribute.
2142 when Attribute_Fore => Fore : begin
2145 Make_Function_Call (Loc,
2146 Name => New_Reference_To (RTE (RE_Fore), Loc),
2148 Parameter_Associations => New_List (
2149 Convert_To (Universal_Real,
2150 Make_Attribute_Reference (Loc,
2151 Prefix => New_Reference_To (Ptyp, Loc),
2152 Attribute_Name => Name_First)),
2154 Convert_To (Universal_Real,
2155 Make_Attribute_Reference (Loc,
2156 Prefix => New_Reference_To (Ptyp, Loc),
2157 Attribute_Name => Name_Last))))));
2159 Analyze_And_Resolve (N, Typ);
2166 -- Transforms 'Fraction into a call to the floating-point attribute
2167 -- function Fraction in Fat_xxx (where xxx is the root type)
2169 when Attribute_Fraction =>
2170 Expand_Fpt_Attribute_R (N);
2176 when Attribute_From_Any => From_Any : declare
2177 P_Type : constant Entity_Id := Etype (Pref);
2178 Decls : constant List_Id := New_List;
2181 Build_From_Any_Call (P_Type,
2182 Relocate_Node (First (Exprs)),
2184 Insert_Actions (N, Decls);
2185 Analyze_And_Resolve (N, P_Type);
2192 -- For an exception returns a reference to the exception data:
2193 -- Exception_Id!(Prefix'Reference)
2195 -- For a task it returns a reference to the _task_id component of
2196 -- corresponding record:
2198 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
2200 -- in Ada.Task_Identification
2202 when Attribute_Identity => Identity : declare
2203 Id_Kind : Entity_Id;
2206 if Ptyp = Standard_Exception_Type then
2207 Id_Kind := RTE (RE_Exception_Id);
2209 if Present (Renamed_Object (Entity (Pref))) then
2210 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
2214 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
2216 Id_Kind := RTE (RO_AT_Task_Id);
2218 -- If the prefix is a task interface, the Task_Id is obtained
2219 -- dynamically through a dispatching call, as for other task
2220 -- attributes applied to interfaces.
2222 if Ada_Version >= Ada_2005
2223 and then Ekind (Ptyp) = E_Class_Wide_Type
2224 and then Is_Interface (Ptyp)
2225 and then Is_Task_Interface (Ptyp)
2228 Unchecked_Convert_To (Id_Kind,
2229 Make_Selected_Component (Loc,
2231 New_Copy_Tree (Pref),
2233 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
2237 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
2241 Analyze_And_Resolve (N, Id_Kind);
2248 -- Image attribute is handled in separate unit Exp_Imgv
2250 when Attribute_Image =>
2251 Exp_Imgv.Expand_Image_Attribute (N);
2257 -- X'Img is expanded to typ'Image (X), where typ is the type of X
2259 when Attribute_Img => Img :
2262 Make_Attribute_Reference (Loc,
2263 Prefix => New_Reference_To (Ptyp, Loc),
2264 Attribute_Name => Name_Image,
2265 Expressions => New_List (Relocate_Node (Pref))));
2267 Analyze_And_Resolve (N, Standard_String);
2274 when Attribute_Input => Input : declare
2275 P_Type : constant Entity_Id := Entity (Pref);
2276 B_Type : constant Entity_Id := Base_Type (P_Type);
2277 U_Type : constant Entity_Id := Underlying_Type (P_Type);
2278 Strm : constant Node_Id := First (Exprs);
2286 Cntrl : Node_Id := Empty;
2287 -- Value for controlling argument in call. Always Empty except in
2288 -- the dispatching (class-wide type) case, where it is a reference
2289 -- to the dummy object initialized to the right internal tag.
2291 procedure Freeze_Stream_Subprogram (F : Entity_Id);
2292 -- The expansion of the attribute reference may generate a call to
2293 -- a user-defined stream subprogram that is frozen by the call. This
2294 -- can lead to access-before-elaboration problem if the reference
2295 -- appears in an object declaration and the subprogram body has not
2296 -- been seen. The freezing of the subprogram requires special code
2297 -- because it appears in an expanded context where expressions do
2298 -- not freeze their constituents.
2300 ------------------------------
2301 -- Freeze_Stream_Subprogram --
2302 ------------------------------
2304 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
2305 Decl : constant Node_Id := Unit_Declaration_Node (F);
2309 -- If this is user-defined subprogram, the corresponding
2310 -- stream function appears as a renaming-as-body, and the
2311 -- user subprogram must be retrieved by tree traversal.
2314 and then Nkind (Decl) = N_Subprogram_Declaration
2315 and then Present (Corresponding_Body (Decl))
2317 Bod := Corresponding_Body (Decl);
2319 if Nkind (Unit_Declaration_Node (Bod)) =
2320 N_Subprogram_Renaming_Declaration
2322 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
2325 end Freeze_Stream_Subprogram;
2327 -- Start of processing for Input
2330 -- If no underlying type, we have an error that will be diagnosed
2331 -- elsewhere, so here we just completely ignore the expansion.
2337 -- If there is a TSS for Input, just call it
2339 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
2341 if Present (Fname) then
2345 -- If there is a Stream_Convert pragma, use it, we rewrite
2347 -- sourcetyp'Input (stream)
2351 -- sourcetyp (streamread (strmtyp'Input (stream)));
2353 -- where streamread is the given Read function that converts an
2354 -- argument of type strmtyp to type sourcetyp or a type from which
2355 -- it is derived (extra conversion required for the derived case).
2357 Prag := Get_Stream_Convert_Pragma (P_Type);
2359 if Present (Prag) then
2360 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
2361 Rfunc := Entity (Expression (Arg2));
2365 Make_Function_Call (Loc,
2366 Name => New_Occurrence_Of (Rfunc, Loc),
2367 Parameter_Associations => New_List (
2368 Make_Attribute_Reference (Loc,
2371 (Etype (First_Formal (Rfunc)), Loc),
2372 Attribute_Name => Name_Input,
2373 Expressions => Exprs)))));
2375 Analyze_And_Resolve (N, B_Type);
2380 elsif Is_Elementary_Type (U_Type) then
2382 -- A special case arises if we have a defined _Read routine,
2383 -- since in this case we are required to call this routine.
2385 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
2386 Build_Record_Or_Elementary_Input_Function
2387 (Loc, U_Type, Decl, Fname);
2388 Insert_Action (N, Decl);
2390 -- For normal cases, we call the I_xxx routine directly
2393 Rewrite (N, Build_Elementary_Input_Call (N));
2394 Analyze_And_Resolve (N, P_Type);
2400 elsif Is_Array_Type (U_Type) then
2401 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
2402 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
2404 -- Dispatching case with class-wide type
2406 elsif Is_Class_Wide_Type (P_Type) then
2408 -- No need to do anything else compiling under restriction
2409 -- No_Dispatching_Calls. During the semantic analysis we
2410 -- already notified such violation.
2412 if Restriction_Active (No_Dispatching_Calls) then
2417 Rtyp : constant Entity_Id := Root_Type (P_Type);
2423 -- Read the internal tag (RM 13.13.2(34)) and use it to
2424 -- initialize a dummy tag object:
2426 -- Dnn : Ada.Tags.Tag :=
2427 -- Descendant_Tag (String'Input (Strm), P_Type);
2429 -- This dummy object is used only to provide a controlling
2430 -- argument for the eventual _Input call. Descendant_Tag is
2431 -- called rather than Internal_Tag to ensure that we have a
2432 -- tag for a type that is descended from the prefix type and
2433 -- declared at the same accessibility level (the exception
2434 -- Tag_Error will be raised otherwise). The level check is
2435 -- required for Ada 2005 because tagged types can be
2436 -- extended in nested scopes (AI-344).
2439 Make_Function_Call (Loc,
2441 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
2442 Parameter_Associations => New_List (
2443 Make_Attribute_Reference (Loc,
2444 Prefix => New_Occurrence_Of (Standard_String, Loc),
2445 Attribute_Name => Name_Input,
2446 Expressions => New_List (
2447 Relocate_Node (Duplicate_Subexpr (Strm)))),
2448 Make_Attribute_Reference (Loc,
2449 Prefix => New_Reference_To (P_Type, Loc),
2450 Attribute_Name => Name_Tag)));
2452 Dnn := Make_Temporary (Loc, 'D', Expr);
2455 Make_Object_Declaration (Loc,
2456 Defining_Identifier => Dnn,
2457 Object_Definition =>
2458 New_Occurrence_Of (RTE (RE_Tag), Loc),
2459 Expression => Expr);
2461 Insert_Action (N, Decl);
2463 -- Now we need to get the entity for the call, and construct
2464 -- a function call node, where we preset a reference to Dnn
2465 -- as the controlling argument (doing an unchecked convert
2466 -- to the class-wide tagged type to make it look like a real
2469 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
2471 Unchecked_Convert_To (P_Type,
2472 New_Occurrence_Of (Dnn, Loc));
2473 Set_Etype (Cntrl, P_Type);
2474 Set_Parent (Cntrl, N);
2477 -- For tagged types, use the primitive Input function
2479 elsif Is_Tagged_Type (U_Type) then
2480 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
2482 -- All other record type cases, including protected records. The
2483 -- latter only arise for expander generated code for handling
2484 -- shared passive partition access.
2488 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
2490 -- Ada 2005 (AI-216): Program_Error is raised executing default
2491 -- implementation of the Input attribute of an unchecked union
2492 -- type if the type lacks default discriminant values.
2494 if Is_Unchecked_Union (Base_Type (U_Type))
2495 and then No (Discriminant_Constraint (U_Type))
2498 Make_Raise_Program_Error (Loc,
2499 Reason => PE_Unchecked_Union_Restriction));
2504 Build_Record_Or_Elementary_Input_Function
2505 (Loc, Base_Type (U_Type), Decl, Fname);
2506 Insert_Action (N, Decl);
2508 if Nkind (Parent (N)) = N_Object_Declaration
2509 and then Is_Record_Type (U_Type)
2511 -- The stream function may contain calls to user-defined
2512 -- Read procedures for individual components.
2519 Comp := First_Component (U_Type);
2520 while Present (Comp) loop
2522 Find_Stream_Subprogram
2523 (Etype (Comp), TSS_Stream_Read);
2525 if Present (Func) then
2526 Freeze_Stream_Subprogram (Func);
2529 Next_Component (Comp);
2536 -- If we fall through, Fname is the function to be called. The result
2537 -- is obtained by calling the appropriate function, then converting
2538 -- the result. The conversion does a subtype check.
2541 Make_Function_Call (Loc,
2542 Name => New_Occurrence_Of (Fname, Loc),
2543 Parameter_Associations => New_List (
2544 Relocate_Node (Strm)));
2546 Set_Controlling_Argument (Call, Cntrl);
2547 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
2548 Analyze_And_Resolve (N, P_Type);
2550 if Nkind (Parent (N)) = N_Object_Declaration then
2551 Freeze_Stream_Subprogram (Fname);
2561 -- inttype'Fixed_Value (fixed-value)
2565 -- inttype(integer-value))
2567 -- we do all the required analysis of the conversion here, because we do
2568 -- not want this to go through the fixed-point conversion circuits. Note
2569 -- that the back end always treats fixed-point as equivalent to the
2570 -- corresponding integer type anyway.
2572 when Attribute_Integer_Value => Integer_Value :
2575 Make_Type_Conversion (Loc,
2576 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2577 Expression => Relocate_Node (First (Exprs))));
2578 Set_Etype (N, Entity (Pref));
2581 -- Note: it might appear that a properly analyzed unchecked conversion
2582 -- would be just fine here, but that's not the case, since the full
2583 -- range checks performed by the following call are critical!
2585 Apply_Type_Conversion_Checks (N);
2592 when Attribute_Invalid_Value =>
2593 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
2599 when Attribute_Last =>
2601 -- If the prefix type is a constrained packed array type which
2602 -- already has a Packed_Array_Type representation defined, then
2603 -- replace this attribute with a direct reference to 'Last of the
2604 -- appropriate index subtype (since otherwise the back end will try
2605 -- to give us the value of 'Last for this implementation type).
2607 if Is_Constrained_Packed_Array (Ptyp) then
2609 Make_Attribute_Reference (Loc,
2610 Attribute_Name => Name_Last,
2611 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2612 Analyze_And_Resolve (N, Typ);
2614 elsif Is_Access_Type (Ptyp) then
2615 Apply_Access_Check (N);
2622 -- We compute this if a component clause was present, otherwise we leave
2623 -- the computation up to the back end, since we don't know what layout
2626 when Attribute_Last_Bit => Last_Bit : declare
2627 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2630 if Known_Static_Component_Bit_Offset (CE)
2631 and then Known_Static_Esize (CE)
2634 Make_Integer_Literal (Loc,
2635 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
2638 Analyze_And_Resolve (N, Typ);
2641 Apply_Universal_Integer_Attribute_Checks (N);
2649 -- Transforms 'Leading_Part into a call to the floating-point attribute
2650 -- function Leading_Part in Fat_xxx (where xxx is the root type)
2652 -- Note: strictly, we should generate special case code to deal with
2653 -- absurdly large positive arguments (greater than Integer'Last), which
2654 -- result in returning the first argument unchanged, but it hardly seems
2655 -- worth the effort. We raise constraint error for absurdly negative
2656 -- arguments which is fine.
2658 when Attribute_Leading_Part =>
2659 Expand_Fpt_Attribute_RI (N);
2665 when Attribute_Length => declare
2670 -- Processing for packed array types
2672 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
2673 Ityp := Get_Index_Subtype (N);
2675 -- If the index type, Ityp, is an enumeration type with holes,
2676 -- then we calculate X'Length explicitly using
2679 -- (0, Ityp'Pos (X'Last (N)) -
2680 -- Ityp'Pos (X'First (N)) + 1);
2682 -- Since the bounds in the template are the representation values
2683 -- and the back end would get the wrong value.
2685 if Is_Enumeration_Type (Ityp)
2686 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
2691 Xnum := Expr_Value (First (Expressions (N)));
2695 Make_Attribute_Reference (Loc,
2696 Prefix => New_Occurrence_Of (Typ, Loc),
2697 Attribute_Name => Name_Max,
2698 Expressions => New_List
2699 (Make_Integer_Literal (Loc, 0),
2703 Make_Op_Subtract (Loc,
2705 Make_Attribute_Reference (Loc,
2706 Prefix => New_Occurrence_Of (Ityp, Loc),
2707 Attribute_Name => Name_Pos,
2709 Expressions => New_List (
2710 Make_Attribute_Reference (Loc,
2711 Prefix => Duplicate_Subexpr (Pref),
2712 Attribute_Name => Name_Last,
2713 Expressions => New_List (
2714 Make_Integer_Literal (Loc, Xnum))))),
2717 Make_Attribute_Reference (Loc,
2718 Prefix => New_Occurrence_Of (Ityp, Loc),
2719 Attribute_Name => Name_Pos,
2721 Expressions => New_List (
2722 Make_Attribute_Reference (Loc,
2724 Duplicate_Subexpr_No_Checks (Pref),
2725 Attribute_Name => Name_First,
2726 Expressions => New_List (
2727 Make_Integer_Literal (Loc, Xnum)))))),
2729 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
2731 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
2734 -- If the prefix type is a constrained packed array type which
2735 -- already has a Packed_Array_Type representation defined, then
2736 -- replace this attribute with a direct reference to 'Range_Length
2737 -- of the appropriate index subtype (since otherwise the back end
2738 -- will try to give us the value of 'Length for this
2739 -- implementation type).
2741 elsif Is_Constrained (Ptyp) then
2743 Make_Attribute_Reference (Loc,
2744 Attribute_Name => Name_Range_Length,
2745 Prefix => New_Reference_To (Ityp, Loc)));
2746 Analyze_And_Resolve (N, Typ);
2751 elsif Is_Access_Type (Ptyp) then
2752 Apply_Access_Check (N);
2754 -- If the designated type is a packed array type, then we convert
2755 -- the reference to:
2758 -- xtyp'Pos (Pref'Last (Expr)) -
2759 -- xtyp'Pos (Pref'First (Expr)));
2761 -- This is a bit complex, but it is the easiest thing to do that
2762 -- works in all cases including enum types with holes xtyp here
2763 -- is the appropriate index type.
2766 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
2770 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
2771 Xtyp := Get_Index_Subtype (N);
2774 Make_Attribute_Reference (Loc,
2775 Prefix => New_Occurrence_Of (Typ, Loc),
2776 Attribute_Name => Name_Max,
2777 Expressions => New_List (
2778 Make_Integer_Literal (Loc, 0),
2781 Make_Integer_Literal (Loc, 1),
2782 Make_Op_Subtract (Loc,
2784 Make_Attribute_Reference (Loc,
2785 Prefix => New_Occurrence_Of (Xtyp, Loc),
2786 Attribute_Name => Name_Pos,
2787 Expressions => New_List (
2788 Make_Attribute_Reference (Loc,
2789 Prefix => Duplicate_Subexpr (Pref),
2790 Attribute_Name => Name_Last,
2792 New_Copy_List (Exprs)))),
2795 Make_Attribute_Reference (Loc,
2796 Prefix => New_Occurrence_Of (Xtyp, Loc),
2797 Attribute_Name => Name_Pos,
2798 Expressions => New_List (
2799 Make_Attribute_Reference (Loc,
2801 Duplicate_Subexpr_No_Checks (Pref),
2802 Attribute_Name => Name_First,
2804 New_Copy_List (Exprs)))))))));
2806 Analyze_And_Resolve (N, Typ);
2810 -- Otherwise leave it to the back end
2813 Apply_Universal_Integer_Attribute_Checks (N);
2821 -- Transforms 'Machine into a call to the floating-point attribute
2822 -- function Machine in Fat_xxx (where xxx is the root type)
2824 when Attribute_Machine =>
2825 Expand_Fpt_Attribute_R (N);
2827 ----------------------
2828 -- Machine_Rounding --
2829 ----------------------
2831 -- Transforms 'Machine_Rounding into a call to the floating-point
2832 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
2833 -- type). Expansion is avoided for cases the back end can handle
2836 when Attribute_Machine_Rounding =>
2837 if not Is_Inline_Floating_Point_Attribute (N) then
2838 Expand_Fpt_Attribute_R (N);
2845 -- Machine_Size is equivalent to Object_Size, so transform it into
2846 -- Object_Size and that way the back end never sees Machine_Size.
2848 when Attribute_Machine_Size =>
2850 Make_Attribute_Reference (Loc,
2851 Prefix => Prefix (N),
2852 Attribute_Name => Name_Object_Size));
2854 Analyze_And_Resolve (N, Typ);
2860 -- The only case that can get this far is the dynamic case of the old
2861 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
2868 -- ityp (System.Mantissa.Mantissa_Value
2869 -- (Integer'Integer_Value (typ'First),
2870 -- Integer'Integer_Value (typ'Last)));
2872 when Attribute_Mantissa => Mantissa : begin
2875 Make_Function_Call (Loc,
2876 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
2878 Parameter_Associations => New_List (
2880 Make_Attribute_Reference (Loc,
2881 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2882 Attribute_Name => Name_Integer_Value,
2883 Expressions => New_List (
2885 Make_Attribute_Reference (Loc,
2886 Prefix => New_Occurrence_Of (Ptyp, Loc),
2887 Attribute_Name => Name_First))),
2889 Make_Attribute_Reference (Loc,
2890 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2891 Attribute_Name => Name_Integer_Value,
2892 Expressions => New_List (
2894 Make_Attribute_Reference (Loc,
2895 Prefix => New_Occurrence_Of (Ptyp, Loc),
2896 Attribute_Name => Name_Last)))))));
2898 Analyze_And_Resolve (N, Typ);
2901 --------------------
2902 -- Mechanism_Code --
2903 --------------------
2905 when Attribute_Mechanism_Code =>
2907 -- We must replace the prefix in the renamed case
2909 if Is_Entity_Name (Pref)
2910 and then Present (Alias (Entity (Pref)))
2912 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
2919 when Attribute_Mod => Mod_Case : declare
2920 Arg : constant Node_Id := Relocate_Node (First (Exprs));
2921 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
2922 Modv : constant Uint := Modulus (Btyp);
2926 -- This is not so simple. The issue is what type to use for the
2927 -- computation of the modular value.
2929 -- The easy case is when the modulus value is within the bounds
2930 -- of the signed integer type of the argument. In this case we can
2931 -- just do the computation in that signed integer type, and then
2932 -- do an ordinary conversion to the target type.
2934 if Modv <= Expr_Value (Hi) then
2939 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
2941 -- Here we know that the modulus is larger than type'Last of the
2942 -- integer type. There are two cases to consider:
2944 -- a) The integer value is non-negative. In this case, it is
2945 -- returned as the result (since it is less than the modulus).
2947 -- b) The integer value is negative. In this case, we know that the
2948 -- result is modulus + value, where the value might be as small as
2949 -- -modulus. The trouble is what type do we use to do the subtract.
2950 -- No type will do, since modulus can be as big as 2**64, and no
2951 -- integer type accommodates this value. Let's do bit of algebra
2954 -- = modulus - (-value)
2955 -- = (modulus - 1) - (-value - 1)
2957 -- Now modulus - 1 is certainly in range of the modular type.
2958 -- -value is in the range 1 .. modulus, so -value -1 is in the
2959 -- range 0 .. modulus-1 which is in range of the modular type.
2960 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
2961 -- which we can compute using the integer base type.
2963 -- Once this is done we analyze the conditional expression without
2964 -- range checks, because we know everything is in range, and we
2965 -- want to prevent spurious warnings on either branch.
2969 Make_Conditional_Expression (Loc,
2970 Expressions => New_List (
2972 Left_Opnd => Duplicate_Subexpr (Arg),
2973 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2976 Duplicate_Subexpr_No_Checks (Arg)),
2978 Make_Op_Subtract (Loc,
2980 Make_Integer_Literal (Loc,
2981 Intval => Modv - 1),
2987 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
2989 Make_Integer_Literal (Loc,
2990 Intval => 1))))))));
2994 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
3001 -- Transforms 'Model into a call to the floating-point attribute
3002 -- function Model in Fat_xxx (where xxx is the root type)
3004 when Attribute_Model =>
3005 Expand_Fpt_Attribute_R (N);
3011 -- The processing for Object_Size shares the processing for Size
3017 when Attribute_Old => Old : declare
3018 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', Pref);
3023 -- Find the nearest subprogram body, ignoring _Preconditions
3027 Subp := Parent (Subp);
3028 exit when Nkind (Subp) = N_Subprogram_Body
3029 and then Chars (Defining_Entity (Subp)) /= Name_uPostconditions;
3032 -- Insert the initialized object declaration at the start of the
3033 -- subprogram's declarations.
3036 Make_Object_Declaration (Loc,
3037 Defining_Identifier => Tnn,
3038 Constant_Present => True,
3039 Object_Definition => New_Occurrence_Of (Etype (N), Loc),
3040 Expression => Pref);
3042 -- Push the subprogram's scope, so that the object will be analyzed
3043 -- in that context (rather than the context of the Precondition
3044 -- subprogram) and will have its Scope set properly.
3046 if Present (Corresponding_Spec (Subp)) then
3047 Push_Scope (Corresponding_Spec (Subp));
3049 Push_Scope (Defining_Entity (Subp));
3052 if Is_Empty_List (Declarations (Subp)) then
3053 Set_Declarations (Subp, New_List (Asn_Stm));
3056 Insert_Action (First (Declarations (Subp)), Asn_Stm);
3061 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
3068 when Attribute_Output => Output : declare
3069 P_Type : constant Entity_Id := Entity (Pref);
3070 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3078 -- If no underlying type, we have an error that will be diagnosed
3079 -- elsewhere, so here we just completely ignore the expansion.
3085 -- If TSS for Output is present, just call it
3087 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
3089 if Present (Pname) then
3093 -- If there is a Stream_Convert pragma, use it, we rewrite
3095 -- sourcetyp'Output (stream, Item)
3099 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
3101 -- where strmwrite is the given Write function that converts an
3102 -- argument of type sourcetyp or a type acctyp, from which it is
3103 -- derived to type strmtyp. The conversion to acttyp is required
3104 -- for the derived case.
3106 Prag := Get_Stream_Convert_Pragma (P_Type);
3108 if Present (Prag) then
3110 Next (Next (First (Pragma_Argument_Associations (Prag))));
3111 Wfunc := Entity (Expression (Arg3));
3114 Make_Attribute_Reference (Loc,
3115 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
3116 Attribute_Name => Name_Output,
3117 Expressions => New_List (
3118 Relocate_Node (First (Exprs)),
3119 Make_Function_Call (Loc,
3120 Name => New_Occurrence_Of (Wfunc, Loc),
3121 Parameter_Associations => New_List (
3122 OK_Convert_To (Etype (First_Formal (Wfunc)),
3123 Relocate_Node (Next (First (Exprs)))))))));
3128 -- For elementary types, we call the W_xxx routine directly.
3129 -- Note that the effect of Write and Output is identical for
3130 -- the case of an elementary type, since there are no
3131 -- discriminants or bounds.
3133 elsif Is_Elementary_Type (U_Type) then
3135 -- A special case arises if we have a defined _Write routine,
3136 -- since in this case we are required to call this routine.
3138 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
3139 Build_Record_Or_Elementary_Output_Procedure
3140 (Loc, U_Type, Decl, Pname);
3141 Insert_Action (N, Decl);
3143 -- For normal cases, we call the W_xxx routine directly
3146 Rewrite (N, Build_Elementary_Write_Call (N));
3153 elsif Is_Array_Type (U_Type) then
3154 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
3155 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3157 -- Class-wide case, first output external tag, then dispatch
3158 -- to the appropriate primitive Output function (RM 13.13.2(31)).
3160 elsif Is_Class_Wide_Type (P_Type) then
3162 -- No need to do anything else compiling under restriction
3163 -- No_Dispatching_Calls. During the semantic analysis we
3164 -- already notified such violation.
3166 if Restriction_Active (No_Dispatching_Calls) then
3171 Strm : constant Node_Id := First (Exprs);
3172 Item : constant Node_Id := Next (Strm);
3175 -- Ada 2005 (AI-344): Check that the accessibility level
3176 -- of the type of the output object is not deeper than
3177 -- that of the attribute's prefix type.
3179 -- if Get_Access_Level (Item'Tag)
3180 -- /= Get_Access_Level (P_Type'Tag)
3185 -- String'Output (Strm, External_Tag (Item'Tag));
3187 -- We cannot figure out a practical way to implement this
3188 -- accessibility check on virtual machines, so we omit it.
3190 if Ada_Version >= Ada_2005
3191 and then Tagged_Type_Expansion
3194 Make_Implicit_If_Statement (N,
3198 Build_Get_Access_Level (Loc,
3199 Make_Attribute_Reference (Loc,
3202 Duplicate_Subexpr (Item,
3204 Attribute_Name => Name_Tag)),
3207 Make_Integer_Literal (Loc,
3208 Type_Access_Level (P_Type))),
3211 New_List (Make_Raise_Statement (Loc,
3213 RTE (RE_Tag_Error), Loc)))));
3217 Make_Attribute_Reference (Loc,
3218 Prefix => New_Occurrence_Of (Standard_String, Loc),
3219 Attribute_Name => Name_Output,
3220 Expressions => New_List (
3221 Relocate_Node (Duplicate_Subexpr (Strm)),
3222 Make_Function_Call (Loc,
3224 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3225 Parameter_Associations => New_List (
3226 Make_Attribute_Reference (Loc,
3229 (Duplicate_Subexpr (Item, Name_Req => True)),
3230 Attribute_Name => Name_Tag))))));
3233 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3235 -- Tagged type case, use the primitive Output function
3237 elsif Is_Tagged_Type (U_Type) then
3238 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3240 -- All other record type cases, including protected records.
3241 -- The latter only arise for expander generated code for
3242 -- handling shared passive partition access.
3246 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3248 -- Ada 2005 (AI-216): Program_Error is raised when executing
3249 -- the default implementation of the Output attribute of an
3250 -- unchecked union type if the type lacks default discriminant
3253 if Is_Unchecked_Union (Base_Type (U_Type))
3254 and then No (Discriminant_Constraint (U_Type))
3257 Make_Raise_Program_Error (Loc,
3258 Reason => PE_Unchecked_Union_Restriction));
3263 Build_Record_Or_Elementary_Output_Procedure
3264 (Loc, Base_Type (U_Type), Decl, Pname);
3265 Insert_Action (N, Decl);
3269 -- If we fall through, Pname is the name of the procedure to call
3271 Rewrite_Stream_Proc_Call (Pname);
3278 -- For enumeration types with a standard representation, Pos is
3279 -- handled by the back end.
3281 -- For enumeration types, with a non-standard representation we generate
3282 -- a call to the _Rep_To_Pos function created when the type was frozen.
3283 -- The call has the form
3285 -- _rep_to_pos (expr, flag)
3287 -- The parameter flag is True if range checks are enabled, causing
3288 -- Program_Error to be raised if the expression has an invalid
3289 -- representation, and False if range checks are suppressed.
3291 -- For integer types, Pos is equivalent to a simple integer
3292 -- conversion and we rewrite it as such
3294 when Attribute_Pos => Pos :
3296 Etyp : Entity_Id := Base_Type (Entity (Pref));
3299 -- Deal with zero/non-zero boolean values
3301 if Is_Boolean_Type (Etyp) then
3302 Adjust_Condition (First (Exprs));
3303 Etyp := Standard_Boolean;
3304 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
3307 -- Case of enumeration type
3309 if Is_Enumeration_Type (Etyp) then
3311 -- Non-standard enumeration type (generate call)
3313 if Present (Enum_Pos_To_Rep (Etyp)) then
3314 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
3317 Make_Function_Call (Loc,
3319 New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3320 Parameter_Associations => Exprs)));
3322 Analyze_And_Resolve (N, Typ);
3324 -- Standard enumeration type (do universal integer check)
3327 Apply_Universal_Integer_Attribute_Checks (N);
3330 -- Deal with integer types (replace by conversion)
3332 elsif Is_Integer_Type (Etyp) then
3333 Rewrite (N, Convert_To (Typ, First (Exprs)));
3334 Analyze_And_Resolve (N, Typ);
3343 -- We compute this if a component clause was present, otherwise we leave
3344 -- the computation up to the back end, since we don't know what layout
3347 when Attribute_Position => Position :
3349 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3352 if Present (Component_Clause (CE)) then
3354 Make_Integer_Literal (Loc,
3355 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
3356 Analyze_And_Resolve (N, Typ);
3359 Apply_Universal_Integer_Attribute_Checks (N);
3367 -- 1. Deal with enumeration types with holes
3368 -- 2. For floating-point, generate call to attribute function
3369 -- 3. For other cases, deal with constraint checking
3371 when Attribute_Pred => Pred :
3373 Etyp : constant Entity_Id := Base_Type (Ptyp);
3377 -- For enumeration types with non-standard representations, we
3378 -- expand typ'Pred (x) into
3380 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
3382 -- If the representation is contiguous, we compute instead
3383 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
3384 -- The conversion function Enum_Pos_To_Rep is defined on the
3385 -- base type, not the subtype, so we have to use the base type
3386 -- explicitly for this and other enumeration attributes.
3388 if Is_Enumeration_Type (Ptyp)
3389 and then Present (Enum_Pos_To_Rep (Etyp))
3391 if Has_Contiguous_Rep (Etyp) then
3393 Unchecked_Convert_To (Ptyp,
3396 Make_Integer_Literal (Loc,
3397 Enumeration_Rep (First_Literal (Ptyp))),
3399 Make_Function_Call (Loc,
3402 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3404 Parameter_Associations =>
3406 Unchecked_Convert_To (Ptyp,
3407 Make_Op_Subtract (Loc,
3409 Unchecked_Convert_To (Standard_Integer,
3410 Relocate_Node (First (Exprs))),
3412 Make_Integer_Literal (Loc, 1))),
3413 Rep_To_Pos_Flag (Ptyp, Loc))))));
3416 -- Add Boolean parameter True, to request program errror if
3417 -- we have a bad representation on our hands. If checks are
3418 -- suppressed, then add False instead
3420 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
3422 Make_Indexed_Component (Loc,
3425 (Enum_Pos_To_Rep (Etyp), Loc),
3426 Expressions => New_List (
3427 Make_Op_Subtract (Loc,
3429 Make_Function_Call (Loc,
3432 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3433 Parameter_Associations => Exprs),
3434 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
3437 Analyze_And_Resolve (N, Typ);
3439 -- For floating-point, we transform 'Pred into a call to the Pred
3440 -- floating-point attribute function in Fat_xxx (xxx is root type)
3442 elsif Is_Floating_Point_Type (Ptyp) then
3443 Expand_Fpt_Attribute_R (N);
3444 Analyze_And_Resolve (N, Typ);
3446 -- For modular types, nothing to do (no overflow, since wraps)
3448 elsif Is_Modular_Integer_Type (Ptyp) then
3451 -- For other types, if argument is marked as needing a range check or
3452 -- overflow checking is enabled, we must generate a check.
3454 elsif not Overflow_Checks_Suppressed (Ptyp)
3455 or else Do_Range_Check (First (Exprs))
3457 Set_Do_Range_Check (First (Exprs), False);
3458 Expand_Pred_Succ (N);
3466 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3468 -- We rewrite X'Priority as the following run-time call:
3470 -- Get_Ceiling (X._Object)
3472 -- Note that although X'Priority is notionally an object, it is quite
3473 -- deliberately not defined as an aliased object in the RM. This means
3474 -- that it works fine to rewrite it as a call, without having to worry
3475 -- about complications that would other arise from X'Priority'Access,
3476 -- which is illegal, because of the lack of aliasing.
3478 when Attribute_Priority =>
3481 Conctyp : Entity_Id;
3482 Object_Parm : Node_Id;
3484 RT_Subprg_Name : Node_Id;
3487 -- Look for the enclosing concurrent type
3489 Conctyp := Current_Scope;
3490 while not Is_Concurrent_Type (Conctyp) loop
3491 Conctyp := Scope (Conctyp);
3494 pragma Assert (Is_Protected_Type (Conctyp));
3496 -- Generate the actual of the call
3498 Subprg := Current_Scope;
3499 while not Present (Protected_Body_Subprogram (Subprg)) loop
3500 Subprg := Scope (Subprg);
3503 -- Use of 'Priority inside protected entries and barriers (in
3504 -- both cases the type of the first formal of their expanded
3505 -- subprogram is Address)
3507 if Etype (First_Entity (Protected_Body_Subprogram (Subprg)))
3511 New_Itype : Entity_Id;
3514 -- In the expansion of protected entries the type of the
3515 -- first formal of the Protected_Body_Subprogram is an
3516 -- Address. In order to reference the _object component
3519 -- type T is access p__ptTV;
3522 New_Itype := Create_Itype (E_Access_Type, N);
3523 Set_Etype (New_Itype, New_Itype);
3524 Set_Directly_Designated_Type (New_Itype,
3525 Corresponding_Record_Type (Conctyp));
3526 Freeze_Itype (New_Itype, N);
3529 -- T!(O)._object'unchecked_access
3532 Make_Attribute_Reference (Loc,
3534 Make_Selected_Component (Loc,
3536 Unchecked_Convert_To (New_Itype,
3539 (Protected_Body_Subprogram (Subprg)),
3542 Make_Identifier (Loc, Name_uObject)),
3543 Attribute_Name => Name_Unchecked_Access);
3546 -- Use of 'Priority inside a protected subprogram
3550 Make_Attribute_Reference (Loc,
3552 Make_Selected_Component (Loc,
3553 Prefix => New_Reference_To
3555 (Protected_Body_Subprogram (Subprg)),
3557 Selector_Name => Make_Identifier (Loc, Name_uObject)),
3558 Attribute_Name => Name_Unchecked_Access);
3561 -- Select the appropriate run-time subprogram
3563 if Number_Entries (Conctyp) = 0 then
3565 New_Reference_To (RTE (RE_Get_Ceiling), Loc);
3568 New_Reference_To (RTE (RO_PE_Get_Ceiling), Loc);
3572 Make_Function_Call (Loc,
3573 Name => RT_Subprg_Name,
3574 Parameter_Associations => New_List (Object_Parm));
3578 -- Avoid the generation of extra checks on the pointer to the
3579 -- protected object.
3581 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
3588 when Attribute_Range_Length => Range_Length : begin
3590 -- The only special processing required is for the case where
3591 -- Range_Length is applied to an enumeration type with holes.
3592 -- In this case we transform
3598 -- X'Pos (X'Last) - X'Pos (X'First) + 1
3600 -- So that the result reflects the proper Pos values instead
3601 -- of the underlying representations.
3603 if Is_Enumeration_Type (Ptyp)
3604 and then Has_Non_Standard_Rep (Ptyp)
3609 Make_Op_Subtract (Loc,
3611 Make_Attribute_Reference (Loc,
3612 Attribute_Name => Name_Pos,
3613 Prefix => New_Occurrence_Of (Ptyp, Loc),
3614 Expressions => New_List (
3615 Make_Attribute_Reference (Loc,
3616 Attribute_Name => Name_Last,
3617 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
3620 Make_Attribute_Reference (Loc,
3621 Attribute_Name => Name_Pos,
3622 Prefix => New_Occurrence_Of (Ptyp, Loc),
3623 Expressions => New_List (
3624 Make_Attribute_Reference (Loc,
3625 Attribute_Name => Name_First,
3626 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
3628 Right_Opnd => Make_Integer_Literal (Loc, 1)));
3630 Analyze_And_Resolve (N, Typ);
3632 -- For all other cases, the attribute is handled by the back end, but
3633 -- we need to deal with the case of the range check on a universal
3637 Apply_Universal_Integer_Attribute_Checks (N);
3645 when Attribute_Read => Read : declare
3646 P_Type : constant Entity_Id := Entity (Pref);
3647 B_Type : constant Entity_Id := Base_Type (P_Type);
3648 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3658 -- If no underlying type, we have an error that will be diagnosed
3659 -- elsewhere, so here we just completely ignore the expansion.
3665 -- The simple case, if there is a TSS for Read, just call it
3667 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
3669 if Present (Pname) then
3673 -- If there is a Stream_Convert pragma, use it, we rewrite
3675 -- sourcetyp'Read (stream, Item)
3679 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
3681 -- where strmread is the given Read function that converts an
3682 -- argument of type strmtyp to type sourcetyp or a type from which
3683 -- it is derived. The conversion to sourcetyp is required in the
3686 -- A special case arises if Item is a type conversion in which
3687 -- case, we have to expand to:
3689 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
3691 -- where Itemx is the expression of the type conversion (i.e.
3692 -- the actual object), and typex is the type of Itemx.
3694 Prag := Get_Stream_Convert_Pragma (P_Type);
3696 if Present (Prag) then
3697 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3698 Rfunc := Entity (Expression (Arg2));
3699 Lhs := Relocate_Node (Next (First (Exprs)));
3701 OK_Convert_To (B_Type,
3702 Make_Function_Call (Loc,
3703 Name => New_Occurrence_Of (Rfunc, Loc),
3704 Parameter_Associations => New_List (
3705 Make_Attribute_Reference (Loc,
3708 (Etype (First_Formal (Rfunc)), Loc),
3709 Attribute_Name => Name_Input,
3710 Expressions => New_List (
3711 Relocate_Node (First (Exprs)))))));
3713 if Nkind (Lhs) = N_Type_Conversion then
3714 Lhs := Expression (Lhs);
3715 Rhs := Convert_To (Etype (Lhs), Rhs);
3719 Make_Assignment_Statement (Loc,
3721 Expression => Rhs));
3722 Set_Assignment_OK (Lhs);
3726 -- For elementary types, we call the I_xxx routine using the first
3727 -- parameter and then assign the result into the second parameter.
3728 -- We set Assignment_OK to deal with the conversion case.
3730 elsif Is_Elementary_Type (U_Type) then
3736 Lhs := Relocate_Node (Next (First (Exprs)));
3737 Rhs := Build_Elementary_Input_Call (N);
3739 if Nkind (Lhs) = N_Type_Conversion then
3740 Lhs := Expression (Lhs);
3741 Rhs := Convert_To (Etype (Lhs), Rhs);
3744 Set_Assignment_OK (Lhs);
3747 Make_Assignment_Statement (Loc,
3749 Expression => Rhs));
3757 elsif Is_Array_Type (U_Type) then
3758 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
3759 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3761 -- Tagged type case, use the primitive Read function. Note that
3762 -- this will dispatch in the class-wide case which is what we want
3764 elsif Is_Tagged_Type (U_Type) then
3765 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
3767 -- All other record type cases, including protected records. The
3768 -- latter only arise for expander generated code for handling
3769 -- shared passive partition access.
3773 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3775 -- Ada 2005 (AI-216): Program_Error is raised when executing
3776 -- the default implementation of the Read attribute of an
3777 -- Unchecked_Union type.
3779 if Is_Unchecked_Union (Base_Type (U_Type)) then
3781 Make_Raise_Program_Error (Loc,
3782 Reason => PE_Unchecked_Union_Restriction));
3785 if Has_Discriminants (U_Type)
3787 (Discriminant_Default_Value (First_Discriminant (U_Type)))
3789 Build_Mutable_Record_Read_Procedure
3790 (Loc, Full_Base (U_Type), Decl, Pname);
3792 Build_Record_Read_Procedure
3793 (Loc, Full_Base (U_Type), Decl, Pname);
3796 -- Suppress checks, uninitialized or otherwise invalid
3797 -- data does not cause constraint errors to be raised for
3798 -- a complete record read.
3800 Insert_Action (N, Decl, All_Checks);
3804 Rewrite_Stream_Proc_Call (Pname);
3811 -- Ref is identical to To_Address, see To_Address for processing
3817 -- Transforms 'Remainder into a call to the floating-point attribute
3818 -- function Remainder in Fat_xxx (where xxx is the root type)
3820 when Attribute_Remainder =>
3821 Expand_Fpt_Attribute_RR (N);
3827 -- Transform 'Result into reference to _Result formal. At the point
3828 -- where a legal 'Result attribute is expanded, we know that we are in
3829 -- the context of a _Postcondition function with a _Result parameter.
3831 when Attribute_Result =>
3832 Rewrite (N, Make_Identifier (Loc, Chars => Name_uResult));
3833 Analyze_And_Resolve (N, Typ);
3839 -- The handling of the Round attribute is quite delicate. The processing
3840 -- in Sem_Attr introduced a conversion to universal real, reflecting the
3841 -- semantics of Round, but we do not want anything to do with universal
3842 -- real at runtime, since this corresponds to using floating-point
3845 -- What we have now is that the Etype of the Round attribute correctly
3846 -- indicates the final result type. The operand of the Round is the
3847 -- conversion to universal real, described above, and the operand of
3848 -- this conversion is the actual operand of Round, which may be the
3849 -- special case of a fixed point multiplication or division (Etype =
3852 -- The exapander will expand first the operand of the conversion, then
3853 -- the conversion, and finally the round attribute itself, since we
3854 -- always work inside out. But we cannot simply process naively in this
3855 -- order. In the semantic world where universal fixed and real really
3856 -- exist and have infinite precision, there is no problem, but in the
3857 -- implementation world, where universal real is a floating-point type,
3858 -- we would get the wrong result.
3860 -- So the approach is as follows. First, when expanding a multiply or
3861 -- divide whose type is universal fixed, we do nothing at all, instead
3862 -- deferring the operation till later.
3864 -- The actual processing is done in Expand_N_Type_Conversion which
3865 -- handles the special case of Round by looking at its parent to see if
3866 -- it is a Round attribute, and if it is, handling the conversion (or
3867 -- its fixed multiply/divide child) in an appropriate manner.
3869 -- This means that by the time we get to expanding the Round attribute
3870 -- itself, the Round is nothing more than a type conversion (and will
3871 -- often be a null type conversion), so we just replace it with the
3872 -- appropriate conversion operation.
3874 when Attribute_Round =>
3876 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
3877 Analyze_And_Resolve (N);
3883 -- Transforms 'Rounding into a call to the floating-point attribute
3884 -- function Rounding in Fat_xxx (where xxx is the root type)
3886 when Attribute_Rounding =>
3887 Expand_Fpt_Attribute_R (N);
3893 -- Transforms 'Scaling into a call to the floating-point attribute
3894 -- function Scaling in Fat_xxx (where xxx is the root type)
3896 when Attribute_Scaling =>
3897 Expand_Fpt_Attribute_RI (N);
3903 when Attribute_Size |
3904 Attribute_Object_Size |
3905 Attribute_Value_Size |
3906 Attribute_VADS_Size => Size :
3913 -- Processing for VADS_Size case. Note that this processing removes
3914 -- all traces of VADS_Size from the tree, and completes all required
3915 -- processing for VADS_Size by translating the attribute reference
3916 -- to an appropriate Size or Object_Size reference.
3918 if Id = Attribute_VADS_Size
3919 or else (Use_VADS_Size and then Id = Attribute_Size)
3921 -- If the size is specified, then we simply use the specified
3922 -- size. This applies to both types and objects. The size of an
3923 -- object can be specified in the following ways:
3925 -- An explicit size object is given for an object
3926 -- A component size is specified for an indexed component
3927 -- A component clause is specified for a selected component
3928 -- The object is a component of a packed composite object
3930 -- If the size is specified, then VADS_Size of an object
3932 if (Is_Entity_Name (Pref)
3933 and then Present (Size_Clause (Entity (Pref))))
3935 (Nkind (Pref) = N_Component_Clause
3936 and then (Present (Component_Clause
3937 (Entity (Selector_Name (Pref))))
3938 or else Is_Packed (Etype (Prefix (Pref)))))
3940 (Nkind (Pref) = N_Indexed_Component
3941 and then (Component_Size (Etype (Prefix (Pref))) /= 0
3942 or else Is_Packed (Etype (Prefix (Pref)))))
3944 Set_Attribute_Name (N, Name_Size);
3946 -- Otherwise if we have an object rather than a type, then the
3947 -- VADS_Size attribute applies to the type of the object, rather
3948 -- than the object itself. This is one of the respects in which
3949 -- VADS_Size differs from Size.
3952 if (not Is_Entity_Name (Pref)
3953 or else not Is_Type (Entity (Pref)))
3954 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
3956 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
3959 -- For a scalar type for which no size was explicitly given,
3960 -- VADS_Size means Object_Size. This is the other respect in
3961 -- which VADS_Size differs from Size.
3963 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
3964 Set_Attribute_Name (N, Name_Object_Size);
3966 -- In all other cases, Size and VADS_Size are the sane
3969 Set_Attribute_Name (N, Name_Size);
3974 -- For class-wide types, X'Class'Size is transformed into a direct
3975 -- reference to the Size of the class type, so that the back end does
3976 -- not have to deal with the X'Class'Size reference.
3978 if Is_Entity_Name (Pref)
3979 and then Is_Class_Wide_Type (Entity (Pref))
3981 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
3984 -- For X'Size applied to an object of a class-wide type, transform
3985 -- X'Size into a call to the primitive operation _Size applied to X.
3987 elsif Is_Class_Wide_Type (Ptyp)
3988 or else (Id = Attribute_Size
3989 and then Is_Tagged_Type (Ptyp)
3990 and then Has_Unknown_Discriminants (Ptyp))
3992 -- No need to do anything else compiling under restriction
3993 -- No_Dispatching_Calls. During the semantic analysis we
3994 -- already notified such violation.
3996 if Restriction_Active (No_Dispatching_Calls) then
4001 Make_Function_Call (Loc,
4002 Name => New_Reference_To
4003 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
4004 Parameter_Associations => New_List (Pref));
4006 if Typ /= Standard_Long_Long_Integer then
4008 -- The context is a specific integer type with which the
4009 -- original attribute was compatible. The function has a
4010 -- specific type as well, so to preserve the compatibility
4011 -- we must convert explicitly.
4013 New_Node := Convert_To (Typ, New_Node);
4016 Rewrite (N, New_Node);
4017 Analyze_And_Resolve (N, Typ);
4020 -- Case of known RM_Size of a type
4022 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
4023 and then Is_Entity_Name (Pref)
4024 and then Is_Type (Entity (Pref))
4025 and then Known_Static_RM_Size (Entity (Pref))
4027 Siz := RM_Size (Entity (Pref));
4029 -- Case of known Esize of a type
4031 elsif Id = Attribute_Object_Size
4032 and then Is_Entity_Name (Pref)
4033 and then Is_Type (Entity (Pref))
4034 and then Known_Static_Esize (Entity (Pref))
4036 Siz := Esize (Entity (Pref));
4038 -- Case of known size of object
4040 elsif Id = Attribute_Size
4041 and then Is_Entity_Name (Pref)
4042 and then Is_Object (Entity (Pref))
4043 and then Known_Esize (Entity (Pref))
4044 and then Known_Static_Esize (Entity (Pref))
4046 Siz := Esize (Entity (Pref));
4048 -- For an array component, we can do Size in the front end
4049 -- if the component_size of the array is set.
4051 elsif Nkind (Pref) = N_Indexed_Component then
4052 Siz := Component_Size (Etype (Prefix (Pref)));
4054 -- For a record component, we can do Size in the front end if there
4055 -- is a component clause, or if the record is packed and the
4056 -- component's size is known at compile time.
4058 elsif Nkind (Pref) = N_Selected_Component then
4060 Rec : constant Entity_Id := Etype (Prefix (Pref));
4061 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
4064 if Present (Component_Clause (Comp)) then
4065 Siz := Esize (Comp);
4067 elsif Is_Packed (Rec) then
4068 Siz := RM_Size (Ptyp);
4071 Apply_Universal_Integer_Attribute_Checks (N);
4076 -- All other cases are handled by the back end
4079 Apply_Universal_Integer_Attribute_Checks (N);
4081 -- If Size is applied to a formal parameter that is of a packed
4082 -- array subtype, then apply Size to the actual subtype.
4084 if Is_Entity_Name (Pref)
4085 and then Is_Formal (Entity (Pref))
4086 and then Is_Array_Type (Ptyp)
4087 and then Is_Packed (Ptyp)
4090 Make_Attribute_Reference (Loc,
4092 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
4093 Attribute_Name => Name_Size));
4094 Analyze_And_Resolve (N, Typ);
4097 -- If Size applies to a dereference of an access to unconstrained
4098 -- packed array, the back end needs to see its unconstrained
4099 -- nominal type, but also a hint to the actual constrained type.
4101 if Nkind (Pref) = N_Explicit_Dereference
4102 and then Is_Array_Type (Ptyp)
4103 and then not Is_Constrained (Ptyp)
4104 and then Is_Packed (Ptyp)
4106 Set_Actual_Designated_Subtype (Pref,
4107 Get_Actual_Subtype (Pref));
4113 -- Common processing for record and array component case
4115 if Siz /= No_Uint and then Siz /= 0 then
4117 CS : constant Boolean := Comes_From_Source (N);
4120 Rewrite (N, Make_Integer_Literal (Loc, Siz));
4122 -- This integer literal is not a static expression. We do not
4123 -- call Analyze_And_Resolve here, because this would activate
4124 -- the circuit for deciding that a static value was out of
4125 -- range, and we don't want that.
4127 -- So just manually set the type, mark the expression as non-
4128 -- static, and then ensure that the result is checked properly
4129 -- if the attribute comes from source (if it was internally
4130 -- generated, we never need a constraint check).
4133 Set_Is_Static_Expression (N, False);
4136 Apply_Constraint_Check (N, Typ);
4146 when Attribute_Storage_Pool =>
4148 Make_Type_Conversion (Loc,
4149 Subtype_Mark => New_Reference_To (Etype (N), Loc),
4150 Expression => New_Reference_To (Entity (N), Loc)));
4151 Analyze_And_Resolve (N, Typ);
4157 when Attribute_Storage_Size => Storage_Size : begin
4159 -- Access type case, always go to the root type
4161 -- The case of access types results in a value of zero for the case
4162 -- where no storage size attribute clause has been given. If a
4163 -- storage size has been given, then the attribute is converted
4164 -- to a reference to the variable used to hold this value.
4166 if Is_Access_Type (Ptyp) then
4167 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
4169 Make_Attribute_Reference (Loc,
4170 Prefix => New_Reference_To (Typ, Loc),
4171 Attribute_Name => Name_Max,
4172 Expressions => New_List (
4173 Make_Integer_Literal (Loc, 0),
4176 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
4178 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
4181 Make_Function_Call (Loc,
4185 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
4186 Attribute_Name (N)),
4189 Parameter_Associations => New_List (
4191 (Associated_Storage_Pool (Root_Type (Ptyp)), Loc)))));
4194 Rewrite (N, Make_Integer_Literal (Loc, 0));
4197 Analyze_And_Resolve (N, Typ);
4199 -- For tasks, we retrieve the size directly from the TCB. The
4200 -- size may depend on a discriminant of the type, and therefore
4201 -- can be a per-object expression, so type-level information is
4202 -- not sufficient in general. There are four cases to consider:
4204 -- a) If the attribute appears within a task body, the designated
4205 -- TCB is obtained by a call to Self.
4207 -- b) If the prefix of the attribute is the name of a task object,
4208 -- the designated TCB is the one stored in the corresponding record.
4210 -- c) If the prefix is a task type, the size is obtained from the
4211 -- size variable created for each task type
4213 -- d) If no storage_size was specified for the type , there is no
4214 -- size variable, and the value is a system-specific default.
4217 if In_Open_Scopes (Ptyp) then
4219 -- Storage_Size (Self)
4223 Make_Function_Call (Loc,
4225 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4226 Parameter_Associations =>
4228 Make_Function_Call (Loc,
4230 New_Reference_To (RTE (RE_Self), Loc))))));
4232 elsif not Is_Entity_Name (Pref)
4233 or else not Is_Type (Entity (Pref))
4235 -- Storage_Size (Rec (Obj).Size)
4239 Make_Function_Call (Loc,
4241 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4242 Parameter_Associations =>
4244 Make_Selected_Component (Loc,
4246 Unchecked_Convert_To (
4247 Corresponding_Record_Type (Ptyp),
4248 New_Copy_Tree (Pref)),
4250 Make_Identifier (Loc, Name_uTask_Id))))));
4252 elsif Present (Storage_Size_Variable (Ptyp)) then
4254 -- Static storage size pragma given for type: retrieve value
4255 -- from its allocated storage variable.
4259 Make_Function_Call (Loc,
4260 Name => New_Occurrence_Of (
4261 RTE (RE_Adjust_Storage_Size), Loc),
4262 Parameter_Associations =>
4265 Storage_Size_Variable (Ptyp), Loc)))));
4267 -- Get system default
4271 Make_Function_Call (Loc,
4274 RTE (RE_Default_Stack_Size), Loc))));
4277 Analyze_And_Resolve (N, Typ);
4285 when Attribute_Stream_Size => Stream_Size : declare
4289 -- If we have a Stream_Size clause for this type use it, otherwise
4290 -- the Stream_Size if the size of the type.
4292 if Has_Stream_Size_Clause (Ptyp) then
4295 (Static_Integer (Expression (Stream_Size_Clause (Ptyp))));
4297 Size := UI_To_Int (Esize (Ptyp));
4300 Rewrite (N, Make_Integer_Literal (Loc, Intval => Size));
4301 Analyze_And_Resolve (N, Typ);
4308 -- 1. Deal with enumeration types with holes
4309 -- 2. For floating-point, generate call to attribute function
4310 -- 3. For other cases, deal with constraint checking
4312 when Attribute_Succ => Succ : declare
4313 Etyp : constant Entity_Id := Base_Type (Ptyp);
4317 -- For enumeration types with non-standard representations, we
4318 -- expand typ'Succ (x) into
4320 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
4322 -- If the representation is contiguous, we compute instead
4323 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
4325 if Is_Enumeration_Type (Ptyp)
4326 and then Present (Enum_Pos_To_Rep (Etyp))
4328 if Has_Contiguous_Rep (Etyp) then
4330 Unchecked_Convert_To (Ptyp,
4333 Make_Integer_Literal (Loc,
4334 Enumeration_Rep (First_Literal (Ptyp))),
4336 Make_Function_Call (Loc,
4339 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4341 Parameter_Associations =>
4343 Unchecked_Convert_To (Ptyp,
4346 Unchecked_Convert_To (Standard_Integer,
4347 Relocate_Node (First (Exprs))),
4349 Make_Integer_Literal (Loc, 1))),
4350 Rep_To_Pos_Flag (Ptyp, Loc))))));
4352 -- Add Boolean parameter True, to request program errror if
4353 -- we have a bad representation on our hands. Add False if
4354 -- checks are suppressed.
4356 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4358 Make_Indexed_Component (Loc,
4361 (Enum_Pos_To_Rep (Etyp), Loc),
4362 Expressions => New_List (
4365 Make_Function_Call (Loc,
4368 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4369 Parameter_Associations => Exprs),
4370 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4373 Analyze_And_Resolve (N, Typ);
4375 -- For floating-point, we transform 'Succ into a call to the Succ
4376 -- floating-point attribute function in Fat_xxx (xxx is root type)
4378 elsif Is_Floating_Point_Type (Ptyp) then
4379 Expand_Fpt_Attribute_R (N);
4380 Analyze_And_Resolve (N, Typ);
4382 -- For modular types, nothing to do (no overflow, since wraps)
4384 elsif Is_Modular_Integer_Type (Ptyp) then
4387 -- For other types, if argument is marked as needing a range check or
4388 -- overflow checking is enabled, we must generate a check.
4390 elsif not Overflow_Checks_Suppressed (Ptyp)
4391 or else Do_Range_Check (First (Exprs))
4393 Set_Do_Range_Check (First (Exprs), False);
4394 Expand_Pred_Succ (N);
4402 -- Transforms X'Tag into a direct reference to the tag of X
4404 when Attribute_Tag => Tag : declare
4406 Prefix_Is_Type : Boolean;
4409 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
4410 Ttyp := Entity (Pref);
4411 Prefix_Is_Type := True;
4414 Prefix_Is_Type := False;
4417 if Is_Class_Wide_Type (Ttyp) then
4418 Ttyp := Root_Type (Ttyp);
4421 Ttyp := Underlying_Type (Ttyp);
4423 -- Ada 2005: The type may be a synchronized tagged type, in which
4424 -- case the tag information is stored in the corresponding record.
4426 if Is_Concurrent_Type (Ttyp) then
4427 Ttyp := Corresponding_Record_Type (Ttyp);
4430 if Prefix_Is_Type then
4432 -- For VMs we leave the type attribute unexpanded because
4433 -- there's not a dispatching table to reference.
4435 if Tagged_Type_Expansion then
4437 Unchecked_Convert_To (RTE (RE_Tag),
4439 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
4440 Analyze_And_Resolve (N, RTE (RE_Tag));
4443 -- Ada 2005 (AI-251): The use of 'Tag in the sources always
4444 -- references the primary tag of the actual object. If 'Tag is
4445 -- applied to class-wide interface objects we generate code that
4446 -- displaces "this" to reference the base of the object.
4448 elsif Comes_From_Source (N)
4449 and then Is_Class_Wide_Type (Etype (Prefix (N)))
4450 and then Is_Interface (Etype (Prefix (N)))
4453 -- (To_Tag_Ptr (Prefix'Address)).all
4455 -- Note that Prefix'Address is recursively expanded into a call
4456 -- to Base_Address (Obj.Tag)
4458 -- Not needed for VM targets, since all handled by the VM
4460 if Tagged_Type_Expansion then
4462 Make_Explicit_Dereference (Loc,
4463 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
4464 Make_Attribute_Reference (Loc,
4465 Prefix => Relocate_Node (Pref),
4466 Attribute_Name => Name_Address))));
4467 Analyze_And_Resolve (N, RTE (RE_Tag));
4472 Make_Selected_Component (Loc,
4473 Prefix => Relocate_Node (Pref),
4475 New_Reference_To (First_Tag_Component (Ttyp), Loc)));
4476 Analyze_And_Resolve (N, RTE (RE_Tag));
4484 -- Transforms 'Terminated attribute into a call to Terminated function
4486 when Attribute_Terminated => Terminated :
4488 -- The prefix of Terminated is of a task interface class-wide type.
4490 -- terminated (Task_Id (Pref._disp_get_task_id));
4492 if Ada_Version >= Ada_2005
4493 and then Ekind (Ptyp) = E_Class_Wide_Type
4494 and then Is_Interface (Ptyp)
4495 and then Is_Task_Interface (Ptyp)
4498 Make_Function_Call (Loc,
4500 New_Reference_To (RTE (RE_Terminated), Loc),
4501 Parameter_Associations => New_List (
4502 Make_Unchecked_Type_Conversion (Loc,
4504 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
4506 Make_Selected_Component (Loc,
4508 New_Copy_Tree (Pref),
4510 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
4512 elsif Restricted_Profile then
4514 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
4518 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
4521 Analyze_And_Resolve (N, Standard_Boolean);
4528 -- Transforms System'To_Address (X) and System.Address'Ref (X) into
4529 -- unchecked conversion from (integral) type of X to type address.
4531 when Attribute_To_Address | Attribute_Ref =>
4533 Unchecked_Convert_To (RTE (RE_Address),
4534 Relocate_Node (First (Exprs))));
4535 Analyze_And_Resolve (N, RTE (RE_Address));
4541 when Attribute_To_Any => To_Any : declare
4542 P_Type : constant Entity_Id := Etype (Pref);
4543 Decls : constant List_Id := New_List;
4547 (Convert_To (P_Type,
4548 Relocate_Node (First (Exprs))), Decls));
4549 Insert_Actions (N, Decls);
4550 Analyze_And_Resolve (N, RTE (RE_Any));
4557 -- Transforms 'Truncation into a call to the floating-point attribute
4558 -- function Truncation in Fat_xxx (where xxx is the root type).
4559 -- Expansion is avoided for cases the back end can handle directly.
4561 when Attribute_Truncation =>
4562 if not Is_Inline_Floating_Point_Attribute (N) then
4563 Expand_Fpt_Attribute_R (N);
4570 when Attribute_TypeCode => TypeCode : declare
4571 P_Type : constant Entity_Id := Etype (Pref);
4572 Decls : constant List_Id := New_List;
4574 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
4575 Insert_Actions (N, Decls);
4576 Analyze_And_Resolve (N, RTE (RE_TypeCode));
4579 -----------------------
4580 -- Unbiased_Rounding --
4581 -----------------------
4583 -- Transforms 'Unbiased_Rounding into a call to the floating-point
4584 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
4585 -- root type). Expansion is avoided for cases the back end can handle
4588 when Attribute_Unbiased_Rounding =>
4589 if not Is_Inline_Floating_Point_Attribute (N) then
4590 Expand_Fpt_Attribute_R (N);
4597 when Attribute_UET_Address => UET_Address : declare
4598 Ent : constant Entity_Id := Make_Temporary (Loc, 'T');
4602 Make_Object_Declaration (Loc,
4603 Defining_Identifier => Ent,
4604 Aliased_Present => True,
4605 Object_Definition =>
4606 New_Occurrence_Of (RTE (RE_Address), Loc)));
4608 -- Construct name __gnat_xxx__SDP, where xxx is the unit name
4609 -- in normal external form.
4611 Get_External_Unit_Name_String (Get_Unit_Name (Pref));
4612 Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
4613 Name_Len := Name_Len + 7;
4614 Name_Buffer (1 .. 7) := "__gnat_";
4615 Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
4616 Name_Len := Name_Len + 5;
4618 Set_Is_Imported (Ent);
4619 Set_Interface_Name (Ent,
4620 Make_String_Literal (Loc,
4621 Strval => String_From_Name_Buffer));
4623 -- Set entity as internal to ensure proper Sprint output of its
4624 -- implicit importation.
4626 Set_Is_Internal (Ent);
4629 Make_Attribute_Reference (Loc,
4630 Prefix => New_Occurrence_Of (Ent, Loc),
4631 Attribute_Name => Name_Address));
4633 Analyze_And_Resolve (N, Typ);
4640 -- The processing for VADS_Size is shared with Size
4646 -- For enumeration types with a standard representation, and for all
4647 -- other types, Val is handled by the back end. For enumeration types
4648 -- with a non-standard representation we use the _Pos_To_Rep array that
4649 -- was created when the type was frozen.
4651 when Attribute_Val => Val : declare
4652 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
4655 if Is_Enumeration_Type (Etyp)
4656 and then Present (Enum_Pos_To_Rep (Etyp))
4658 if Has_Contiguous_Rep (Etyp) then
4660 Rep_Node : constant Node_Id :=
4661 Unchecked_Convert_To (Etyp,
4664 Make_Integer_Literal (Loc,
4665 Enumeration_Rep (First_Literal (Etyp))),
4667 (Convert_To (Standard_Integer,
4668 Relocate_Node (First (Exprs))))));
4672 Unchecked_Convert_To (Etyp,
4675 Make_Integer_Literal (Loc,
4676 Enumeration_Rep (First_Literal (Etyp))),
4678 Make_Function_Call (Loc,
4681 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4682 Parameter_Associations => New_List (
4684 Rep_To_Pos_Flag (Etyp, Loc))))));
4689 Make_Indexed_Component (Loc,
4690 Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
4691 Expressions => New_List (
4692 Convert_To (Standard_Integer,
4693 Relocate_Node (First (Exprs))))));
4696 Analyze_And_Resolve (N, Typ);
4698 -- If the argument is marked as requiring a range check then generate
4701 elsif Do_Range_Check (First (Exprs)) then
4702 Set_Do_Range_Check (First (Exprs), False);
4703 Generate_Range_Check (First (Exprs), Etyp, CE_Range_Check_Failed);
4711 -- The code for valid is dependent on the particular types involved.
4712 -- See separate sections below for the generated code in each case.
4714 when Attribute_Valid => Valid : declare
4715 Btyp : Entity_Id := Base_Type (Ptyp);
4718 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
4719 -- Save the validity checking mode. We always turn off validity
4720 -- checking during process of 'Valid since this is one place
4721 -- where we do not want the implicit validity checks to intefere
4722 -- with the explicit validity check that the programmer is doing.
4724 function Make_Range_Test return Node_Id;
4725 -- Build the code for a range test of the form
4726 -- Btyp!(Pref) in Btyp!(Ptyp'First) .. Btyp!(Ptyp'Last)
4728 ---------------------
4729 -- Make_Range_Test --
4730 ---------------------
4732 function Make_Range_Test return Node_Id is
4733 Temp : constant Node_Id := Duplicate_Subexpr (Pref);
4736 -- The value whose validity is being checked has been captured in
4737 -- an object declaration. We certainly don't want this object to
4738 -- appear valid because the declaration initializes it!
4740 if Is_Entity_Name (Temp) then
4741 Set_Is_Known_Valid (Entity (Temp), False);
4747 Unchecked_Convert_To (Btyp, Temp),
4751 Unchecked_Convert_To (Btyp,
4752 Make_Attribute_Reference (Loc,
4753 Prefix => New_Occurrence_Of (Ptyp, Loc),
4754 Attribute_Name => Name_First)),
4756 Unchecked_Convert_To (Btyp,
4757 Make_Attribute_Reference (Loc,
4758 Prefix => New_Occurrence_Of (Ptyp, Loc),
4759 Attribute_Name => Name_Last))));
4760 end Make_Range_Test;
4762 -- Start of processing for Attribute_Valid
4765 -- Do not expand sourced code 'Valid reference in CodePeer mode,
4766 -- will be handled by the back-end directly.
4768 if CodePeer_Mode and then Comes_From_Source (N) then
4772 -- Turn off validity checks. We do not want any implicit validity
4773 -- checks to intefere with the explicit check from the attribute
4775 Validity_Checks_On := False;
4777 -- Floating-point case. This case is handled by the Valid attribute
4778 -- code in the floating-point attribute run-time library.
4780 if Is_Floating_Point_Type (Ptyp) then
4787 case Float_Rep (Btyp) is
4789 -- For vax fpt types, call appropriate routine in special
4790 -- vax floating point unit. No need to worry about loads in
4791 -- this case, since these types have no signalling NaN's.
4793 when VAX_Native => Expand_Vax_Valid (N);
4795 -- The AAMP back end handles Valid for floating-point types
4798 Analyze_And_Resolve (Pref, Ptyp);
4799 Set_Etype (N, Standard_Boolean);
4803 Find_Fat_Info (Ptyp, Ftp, Pkg);
4805 -- If the floating-point object might be unaligned, we
4806 -- need to call the special routine Unaligned_Valid,
4807 -- which makes the needed copy, being careful not to
4808 -- load the value into any floating-point register.
4809 -- The argument in this case is obj'Address (see
4810 -- Unaligned_Valid routine in Fat_Gen).
4812 if Is_Possibly_Unaligned_Object (Pref) then
4813 Expand_Fpt_Attribute
4814 (N, Pkg, Name_Unaligned_Valid,
4816 Make_Attribute_Reference (Loc,
4817 Prefix => Relocate_Node (Pref),
4818 Attribute_Name => Name_Address)));
4820 -- In the normal case where we are sure the object is
4821 -- aligned, we generate a call to Valid, and the argument
4822 -- in this case is obj'Unrestricted_Access (after
4823 -- converting obj to the right floating-point type).
4826 Expand_Fpt_Attribute
4827 (N, Pkg, Name_Valid,
4829 Make_Attribute_Reference (Loc,
4830 Prefix => Unchecked_Convert_To (Ftp, Pref),
4831 Attribute_Name => Name_Unrestricted_Access)));
4835 -- One more task, we still need a range check. Required
4836 -- only if we have a constraint, since the Valid routine
4837 -- catches infinities properly (infinities are never valid).
4839 -- The way we do the range check is simply to create the
4840 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
4842 if not Subtypes_Statically_Match (Ptyp, Btyp) then
4845 Left_Opnd => Relocate_Node (N),
4848 Left_Opnd => Convert_To (Btyp, Pref),
4849 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
4853 -- Enumeration type with holes
4855 -- For enumeration types with holes, the Pos value constructed by
4856 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
4857 -- second argument of False returns minus one for an invalid value,
4858 -- and the non-negative pos value for a valid value, so the
4859 -- expansion of X'Valid is simply:
4861 -- type(X)'Pos (X) >= 0
4863 -- We can't quite generate it that way because of the requirement
4864 -- for the non-standard second argument of False in the resulting
4865 -- rep_to_pos call, so we have to explicitly create:
4867 -- _rep_to_pos (X, False) >= 0
4869 -- If we have an enumeration subtype, we also check that the
4870 -- value is in range:
4872 -- _rep_to_pos (X, False) >= 0
4874 -- (X >= type(X)'First and then type(X)'Last <= X)
4876 elsif Is_Enumeration_Type (Ptyp)
4877 and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp)))
4882 Make_Function_Call (Loc,
4885 (TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc),
4886 Parameter_Associations => New_List (
4888 New_Occurrence_Of (Standard_False, Loc))),
4889 Right_Opnd => Make_Integer_Literal (Loc, 0));
4893 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
4895 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
4897 -- The call to Make_Range_Test will create declarations
4898 -- that need a proper insertion point, but Pref is now
4899 -- attached to a node with no ancestor. Attach to tree
4900 -- even if it is to be rewritten below.
4902 Set_Parent (Tst, Parent (N));
4906 Left_Opnd => Make_Range_Test,
4912 -- Fortran convention booleans
4914 -- For the very special case of Fortran convention booleans, the
4915 -- value is always valid, since it is an integer with the semantics
4916 -- that non-zero is true, and any value is permissible.
4918 elsif Is_Boolean_Type (Ptyp)
4919 and then Convention (Ptyp) = Convention_Fortran
4921 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
4923 -- For biased representations, we will be doing an unchecked
4924 -- conversion without unbiasing the result. That means that the range
4925 -- test has to take this into account, and the proper form of the
4928 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
4930 elsif Has_Biased_Representation (Ptyp) then
4931 Btyp := RTE (RE_Unsigned_32);
4935 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4937 Unchecked_Convert_To (Btyp,
4938 Make_Attribute_Reference (Loc,
4939 Prefix => New_Occurrence_Of (Ptyp, Loc),
4940 Attribute_Name => Name_Range_Length))));
4942 -- For all other scalar types, what we want logically is a
4945 -- X in type(X)'First .. type(X)'Last
4947 -- But that's precisely what won't work because of possible
4948 -- unwanted optimization (and indeed the basic motivation for
4949 -- the Valid attribute is exactly that this test does not work!)
4950 -- What will work is:
4952 -- Btyp!(X) >= Btyp!(type(X)'First)
4954 -- Btyp!(X) <= Btyp!(type(X)'Last)
4956 -- where Btyp is an integer type large enough to cover the full
4957 -- range of possible stored values (i.e. it is chosen on the basis
4958 -- of the size of the type, not the range of the values). We write
4959 -- this as two tests, rather than a range check, so that static
4960 -- evaluation will easily remove either or both of the checks if
4961 -- they can be -statically determined to be true (this happens
4962 -- when the type of X is static and the range extends to the full
4963 -- range of stored values).
4965 -- Unsigned types. Note: it is safe to consider only whether the
4966 -- subtype is unsigned, since we will in that case be doing all
4967 -- unsigned comparisons based on the subtype range. Since we use the
4968 -- actual subtype object size, this is appropriate.
4970 -- For example, if we have
4972 -- subtype x is integer range 1 .. 200;
4973 -- for x'Object_Size use 8;
4975 -- Now the base type is signed, but objects of this type are bits
4976 -- unsigned, and doing an unsigned test of the range 1 to 200 is
4977 -- correct, even though a value greater than 127 looks signed to a
4978 -- signed comparison.
4980 elsif Is_Unsigned_Type (Ptyp) then
4981 if Esize (Ptyp) <= 32 then
4982 Btyp := RTE (RE_Unsigned_32);
4984 Btyp := RTE (RE_Unsigned_64);
4987 Rewrite (N, Make_Range_Test);
4992 if Esize (Ptyp) <= Esize (Standard_Integer) then
4993 Btyp := Standard_Integer;
4995 Btyp := Universal_Integer;
4998 Rewrite (N, Make_Range_Test);
5001 Analyze_And_Resolve (N, Standard_Boolean);
5002 Validity_Checks_On := Save_Validity_Checks_On;
5009 -- Value attribute is handled in separate unti Exp_Imgv
5011 when Attribute_Value =>
5012 Exp_Imgv.Expand_Value_Attribute (N);
5018 -- The processing for Value_Size shares the processing for Size
5024 -- The processing for Version shares the processing for Body_Version
5030 -- Wide_Image attribute is handled in separate unit Exp_Imgv
5032 when Attribute_Wide_Image =>
5033 Exp_Imgv.Expand_Wide_Image_Attribute (N);
5035 ---------------------
5036 -- Wide_Wide_Image --
5037 ---------------------
5039 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
5041 when Attribute_Wide_Wide_Image =>
5042 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
5048 -- We expand typ'Wide_Value (X) into
5051 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
5053 -- Wide_String_To_String is a runtime function that converts its wide
5054 -- string argument to String, converting any non-translatable characters
5055 -- into appropriate escape sequences. This preserves the required
5056 -- semantics of Wide_Value in all cases, and results in a very simple
5057 -- implementation approach.
5059 -- Note: for this approach to be fully standard compliant for the cases
5060 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
5061 -- method must cover the entire character range (e.g. UTF-8). But that
5062 -- is a reasonable requirement when dealing with encoded character
5063 -- sequences. Presumably if one of the restrictive encoding mechanisms
5064 -- is in use such as Shift-JIS, then characters that cannot be
5065 -- represented using this encoding will not appear in any case.
5067 when Attribute_Wide_Value => Wide_Value :
5070 Make_Attribute_Reference (Loc,
5072 Attribute_Name => Name_Value,
5074 Expressions => New_List (
5075 Make_Function_Call (Loc,
5077 New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
5079 Parameter_Associations => New_List (
5080 Relocate_Node (First (Exprs)),
5081 Make_Integer_Literal (Loc,
5082 Intval => Int (Wide_Character_Encoding_Method)))))));
5084 Analyze_And_Resolve (N, Typ);
5087 ---------------------
5088 -- Wide_Wide_Value --
5089 ---------------------
5091 -- We expand typ'Wide_Value_Value (X) into
5094 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
5096 -- Wide_Wide_String_To_String is a runtime function that converts its
5097 -- wide string argument to String, converting any non-translatable
5098 -- characters into appropriate escape sequences. This preserves the
5099 -- required semantics of Wide_Wide_Value in all cases, and results in a
5100 -- very simple implementation approach.
5102 -- It's not quite right where typ = Wide_Wide_Character, because the
5103 -- encoding method may not cover the whole character type ???
5105 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
5108 Make_Attribute_Reference (Loc,
5110 Attribute_Name => Name_Value,
5112 Expressions => New_List (
5113 Make_Function_Call (Loc,
5115 New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc),
5117 Parameter_Associations => New_List (
5118 Relocate_Node (First (Exprs)),
5119 Make_Integer_Literal (Loc,
5120 Intval => Int (Wide_Character_Encoding_Method)))))));
5122 Analyze_And_Resolve (N, Typ);
5123 end Wide_Wide_Value;
5125 ---------------------
5126 -- Wide_Wide_Width --
5127 ---------------------
5129 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
5131 when Attribute_Wide_Wide_Width =>
5132 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
5138 -- Wide_Width attribute is handled in separate unit Exp_Imgv
5140 when Attribute_Wide_Width =>
5141 Exp_Imgv.Expand_Width_Attribute (N, Wide);
5147 -- Width attribute is handled in separate unit Exp_Imgv
5149 when Attribute_Width =>
5150 Exp_Imgv.Expand_Width_Attribute (N, Normal);
5156 when Attribute_Write => Write : declare
5157 P_Type : constant Entity_Id := Entity (Pref);
5158 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5166 -- If no underlying type, we have an error that will be diagnosed
5167 -- elsewhere, so here we just completely ignore the expansion.
5173 -- The simple case, if there is a TSS for Write, just call it
5175 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
5177 if Present (Pname) then
5181 -- If there is a Stream_Convert pragma, use it, we rewrite
5183 -- sourcetyp'Output (stream, Item)
5187 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
5189 -- where strmwrite is the given Write function that converts an
5190 -- argument of type sourcetyp or a type acctyp, from which it is
5191 -- derived to type strmtyp. The conversion to acttyp is required
5192 -- for the derived case.
5194 Prag := Get_Stream_Convert_Pragma (P_Type);
5196 if Present (Prag) then
5198 Next (Next (First (Pragma_Argument_Associations (Prag))));
5199 Wfunc := Entity (Expression (Arg3));
5202 Make_Attribute_Reference (Loc,
5203 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
5204 Attribute_Name => Name_Output,
5205 Expressions => New_List (
5206 Relocate_Node (First (Exprs)),
5207 Make_Function_Call (Loc,
5208 Name => New_Occurrence_Of (Wfunc, Loc),
5209 Parameter_Associations => New_List (
5210 OK_Convert_To (Etype (First_Formal (Wfunc)),
5211 Relocate_Node (Next (First (Exprs)))))))));
5216 -- For elementary types, we call the W_xxx routine directly
5218 elsif Is_Elementary_Type (U_Type) then
5219 Rewrite (N, Build_Elementary_Write_Call (N));
5225 elsif Is_Array_Type (U_Type) then
5226 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
5227 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5229 -- Tagged type case, use the primitive Write function. Note that
5230 -- this will dispatch in the class-wide case which is what we want
5232 elsif Is_Tagged_Type (U_Type) then
5233 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
5235 -- All other record type cases, including protected records.
5236 -- The latter only arise for expander generated code for
5237 -- handling shared passive partition access.
5241 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5243 -- Ada 2005 (AI-216): Program_Error is raised when executing
5244 -- the default implementation of the Write attribute of an
5245 -- Unchecked_Union type. However, if the 'Write reference is
5246 -- within the generated Output stream procedure, Write outputs
5247 -- the components, and the default values of the discriminant
5248 -- are streamed by the Output procedure itself.
5250 if Is_Unchecked_Union (Base_Type (U_Type))
5251 and not Is_TSS (Current_Scope, TSS_Stream_Output)
5254 Make_Raise_Program_Error (Loc,
5255 Reason => PE_Unchecked_Union_Restriction));
5258 if Has_Discriminants (U_Type)
5260 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5262 Build_Mutable_Record_Write_Procedure
5263 (Loc, Full_Base (U_Type), Decl, Pname);
5265 Build_Record_Write_Procedure
5266 (Loc, Full_Base (U_Type), Decl, Pname);
5269 Insert_Action (N, Decl);
5273 -- If we fall through, Pname is the procedure to be called
5275 Rewrite_Stream_Proc_Call (Pname);
5278 -- Component_Size is handled by the back end, unless the component size
5279 -- is known at compile time, which is always true in the packed array
5280 -- case. It is important that the packed array case is handled in the
5281 -- front end (see Eval_Attribute) since the back end would otherwise get
5282 -- confused by the equivalent packed array type.
5284 when Attribute_Component_Size =>
5287 -- The following attributes are handled by the back end (except that
5288 -- static cases have already been evaluated during semantic processing,
5289 -- but in any case the back end should not count on this). The one bit
5290 -- of special processing required is that these attributes typically
5291 -- generate conditionals in the code, so we need to check the relevant
5294 when Attribute_Max |
5296 Check_Restriction (No_Implicit_Conditionals, N);
5298 -- The following attributes are handled by the back end (except that
5299 -- static cases have already been evaluated during semantic processing,
5300 -- but in any case the back end should not count on this).
5302 -- The back end also handles the non-class-wide cases of Size
5304 when Attribute_Bit_Order |
5305 Attribute_Code_Address |
5306 Attribute_Definite |
5307 Attribute_Null_Parameter |
5308 Attribute_Passed_By_Reference |
5309 Attribute_Pool_Address =>
5312 -- The following attributes are also handled by the back end, but return
5313 -- a universal integer result, so may need a conversion for checking
5314 -- that the result is in range.
5316 when Attribute_Aft |
5317 Attribute_Max_Alignment_For_Allocation |
5318 Attribute_Max_Size_In_Storage_Elements =>
5319 Apply_Universal_Integer_Attribute_Checks (N);
5321 -- The following attributes should not appear at this stage, since they
5322 -- have already been handled by the analyzer (and properly rewritten
5323 -- with corresponding values or entities to represent the right values)
5325 when Attribute_Abort_Signal |
5326 Attribute_Address_Size |
5329 Attribute_Compiler_Version |
5330 Attribute_Default_Bit_Order |
5337 Attribute_Fast_Math |
5338 Attribute_Has_Access_Values |
5339 Attribute_Has_Discriminants |
5340 Attribute_Has_Tagged_Values |
5342 Attribute_Machine_Emax |
5343 Attribute_Machine_Emin |
5344 Attribute_Machine_Mantissa |
5345 Attribute_Machine_Overflows |
5346 Attribute_Machine_Radix |
5347 Attribute_Machine_Rounds |
5348 Attribute_Maximum_Alignment |
5349 Attribute_Model_Emin |
5350 Attribute_Model_Epsilon |
5351 Attribute_Model_Mantissa |
5352 Attribute_Model_Small |
5354 Attribute_Partition_ID |
5356 Attribute_Safe_Emax |
5357 Attribute_Safe_First |
5358 Attribute_Safe_Large |
5359 Attribute_Safe_Last |
5360 Attribute_Safe_Small |
5362 Attribute_Signed_Zeros |
5364 Attribute_Storage_Unit |
5365 Attribute_Stub_Type |
5366 Attribute_Target_Name |
5367 Attribute_Type_Class |
5368 Attribute_Type_Key |
5369 Attribute_Unconstrained_Array |
5370 Attribute_Universal_Literal_String |
5371 Attribute_Wchar_T_Size |
5372 Attribute_Word_Size =>
5374 raise Program_Error;
5376 -- The Asm_Input and Asm_Output attributes are not expanded at this
5377 -- stage, but will be eliminated in the expansion of the Asm call, see
5378 -- Exp_Intr for details. So the back end will never see these either.
5380 when Attribute_Asm_Input |
5381 Attribute_Asm_Output =>
5388 when RE_Not_Available =>
5390 end Expand_N_Attribute_Reference;
5392 ----------------------
5393 -- Expand_Pred_Succ --
5394 ----------------------
5396 -- For typ'Pred (exp), we generate the check
5398 -- [constraint_error when exp = typ'Base'First]
5400 -- Similarly, for typ'Succ (exp), we generate the check
5402 -- [constraint_error when exp = typ'Base'Last]
5404 -- These checks are not generated for modular types, since the proper
5405 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
5406 -- We also suppress these checks if we are the right side of an assignment
5407 -- statement or the expression of an object declaration, where the flag
5408 -- Suppress_Assignment_Checks is set for the assignment/declaration.
5410 procedure Expand_Pred_Succ (N : Node_Id) is
5411 Loc : constant Source_Ptr := Sloc (N);
5412 P : constant Node_Id := Parent (N);
5416 if Attribute_Name (N) = Name_Pred then
5422 if not Nkind_In (P, N_Assignment_Statement, N_Object_Declaration)
5423 or else not Suppress_Assignment_Checks (P)
5426 Make_Raise_Constraint_Error (Loc,
5430 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
5432 Make_Attribute_Reference (Loc,
5434 New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
5435 Attribute_Name => Cnam)),
5436 Reason => CE_Overflow_Check_Failed));
5438 end Expand_Pred_Succ;
5444 procedure Find_Fat_Info
5446 Fat_Type : out Entity_Id;
5447 Fat_Pkg : out RE_Id)
5449 Btyp : constant Entity_Id := Base_Type (T);
5450 Rtyp : constant Entity_Id := Root_Type (T);
5451 Digs : constant Nat := UI_To_Int (Digits_Value (Btyp));
5454 -- If the base type is VAX float, then get appropriate VAX float type
5456 if Vax_Float (Btyp) then
5459 Fat_Type := RTE (RE_Fat_VAX_F);
5460 Fat_Pkg := RE_Attr_VAX_F_Float;
5463 Fat_Type := RTE (RE_Fat_VAX_D);
5464 Fat_Pkg := RE_Attr_VAX_D_Float;
5467 Fat_Type := RTE (RE_Fat_VAX_G);
5468 Fat_Pkg := RE_Attr_VAX_G_Float;
5471 raise Program_Error;
5474 -- If root type is VAX float, this is the case where the library has
5475 -- been recompiled in VAX float mode, and we have an IEEE float type.
5476 -- This is when we use the special IEEE Fat packages.
5478 elsif Vax_Float (Rtyp) then
5481 Fat_Type := RTE (RE_Fat_IEEE_Short);
5482 Fat_Pkg := RE_Attr_IEEE_Short;
5485 Fat_Type := RTE (RE_Fat_IEEE_Long);
5486 Fat_Pkg := RE_Attr_IEEE_Long;
5489 raise Program_Error;
5492 -- If neither the base type nor the root type is VAX_Native then VAX
5493 -- float is out of the picture, and we can just use the root type.
5498 if Fat_Type = Standard_Short_Float then
5499 Fat_Pkg := RE_Attr_Short_Float;
5501 elsif Fat_Type = Standard_Float then
5502 Fat_Pkg := RE_Attr_Float;
5504 elsif Fat_Type = Standard_Long_Float then
5505 Fat_Pkg := RE_Attr_Long_Float;
5507 elsif Fat_Type = Standard_Long_Long_Float then
5508 Fat_Pkg := RE_Attr_Long_Long_Float;
5510 -- Universal real (which is its own root type) is treated as being
5511 -- equivalent to Standard.Long_Long_Float, since it is defined to
5512 -- have the same precision as the longest Float type.
5514 elsif Fat_Type = Universal_Real then
5515 Fat_Type := Standard_Long_Long_Float;
5516 Fat_Pkg := RE_Attr_Long_Long_Float;
5519 raise Program_Error;
5524 ----------------------------
5525 -- Find_Stream_Subprogram --
5526 ----------------------------
5528 function Find_Stream_Subprogram
5530 Nam : TSS_Name_Type) return Entity_Id
5532 Base_Typ : constant Entity_Id := Base_Type (Typ);
5533 Ent : constant Entity_Id := TSS (Typ, Nam);
5536 if Present (Ent) then
5540 -- Stream attributes for strings are expanded into library calls. The
5541 -- following checks are disabled when the run-time is not available or
5542 -- when compiling predefined types due to bootstrap issues. As a result,
5543 -- the compiler will generate in-place stream routines for string types
5544 -- that appear in GNAT's library, but will generate calls via rtsfind
5545 -- to library routines for user code.
5547 -- ??? For now, disable this code for JVM, since this generates a
5548 -- VerifyError exception at run time on e.g. c330001.
5550 -- This is disabled for AAMP, to avoid creating dependences on files not
5551 -- supported in the AAMP library (such as s-fileio.adb).
5553 if VM_Target /= JVM_Target
5554 and then not AAMP_On_Target
5556 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5558 -- String as defined in package Ada
5560 if Base_Typ = Standard_String then
5561 if Restriction_Active (No_Stream_Optimizations) then
5562 if Nam = TSS_Stream_Input then
5563 return RTE (RE_String_Input);
5565 elsif Nam = TSS_Stream_Output then
5566 return RTE (RE_String_Output);
5568 elsif Nam = TSS_Stream_Read then
5569 return RTE (RE_String_Read);
5571 else pragma Assert (Nam = TSS_Stream_Write);
5572 return RTE (RE_String_Write);
5576 if Nam = TSS_Stream_Input then
5577 return RTE (RE_String_Input_Blk_IO);
5579 elsif Nam = TSS_Stream_Output then
5580 return RTE (RE_String_Output_Blk_IO);
5582 elsif Nam = TSS_Stream_Read then
5583 return RTE (RE_String_Read_Blk_IO);
5585 else pragma Assert (Nam = TSS_Stream_Write);
5586 return RTE (RE_String_Write_Blk_IO);
5590 -- Wide_String as defined in package Ada
5592 elsif Base_Typ = Standard_Wide_String then
5593 if Restriction_Active (No_Stream_Optimizations) then
5594 if Nam = TSS_Stream_Input then
5595 return RTE (RE_Wide_String_Input);
5597 elsif Nam = TSS_Stream_Output then
5598 return RTE (RE_Wide_String_Output);
5600 elsif Nam = TSS_Stream_Read then
5601 return RTE (RE_Wide_String_Read);
5603 else pragma Assert (Nam = TSS_Stream_Write);
5604 return RTE (RE_Wide_String_Write);
5608 if Nam = TSS_Stream_Input then
5609 return RTE (RE_Wide_String_Input_Blk_IO);
5611 elsif Nam = TSS_Stream_Output then
5612 return RTE (RE_Wide_String_Output_Blk_IO);
5614 elsif Nam = TSS_Stream_Read then
5615 return RTE (RE_Wide_String_Read_Blk_IO);
5617 else pragma Assert (Nam = TSS_Stream_Write);
5618 return RTE (RE_Wide_String_Write_Blk_IO);
5622 -- Wide_Wide_String as defined in package Ada
5624 elsif Base_Typ = Standard_Wide_Wide_String then
5625 if Restriction_Active (No_Stream_Optimizations) then
5626 if Nam = TSS_Stream_Input then
5627 return RTE (RE_Wide_Wide_String_Input);
5629 elsif Nam = TSS_Stream_Output then
5630 return RTE (RE_Wide_Wide_String_Output);
5632 elsif Nam = TSS_Stream_Read then
5633 return RTE (RE_Wide_Wide_String_Read);
5635 else pragma Assert (Nam = TSS_Stream_Write);
5636 return RTE (RE_Wide_Wide_String_Write);
5640 if Nam = TSS_Stream_Input then
5641 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
5643 elsif Nam = TSS_Stream_Output then
5644 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
5646 elsif Nam = TSS_Stream_Read then
5647 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
5649 else pragma Assert (Nam = TSS_Stream_Write);
5650 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
5656 if Is_Tagged_Type (Typ)
5657 and then Is_Derived_Type (Typ)
5659 return Find_Prim_Op (Typ, Nam);
5661 return Find_Inherited_TSS (Typ, Nam);
5663 end Find_Stream_Subprogram;
5669 function Full_Base (T : Entity_Id) return Entity_Id is
5673 BT := Base_Type (T);
5675 if Is_Private_Type (BT)
5676 and then Present (Full_View (BT))
5678 BT := Full_View (BT);
5684 -----------------------
5685 -- Get_Index_Subtype --
5686 -----------------------
5688 function Get_Index_Subtype (N : Node_Id) return Node_Id is
5689 P_Type : Entity_Id := Etype (Prefix (N));
5694 if Is_Access_Type (P_Type) then
5695 P_Type := Designated_Type (P_Type);
5698 if No (Expressions (N)) then
5701 J := UI_To_Int (Expr_Value (First (Expressions (N))));
5704 Indx := First_Index (P_Type);
5710 return Etype (Indx);
5711 end Get_Index_Subtype;
5713 -------------------------------
5714 -- Get_Stream_Convert_Pragma --
5715 -------------------------------
5717 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
5722 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
5723 -- that a stream convert pragma for a tagged type is not inherited from
5724 -- its parent. Probably what is wrong here is that it is basically
5725 -- incorrect to consider a stream convert pragma to be a representation
5726 -- pragma at all ???
5728 N := First_Rep_Item (Implementation_Base_Type (T));
5729 while Present (N) loop
5730 if Nkind (N) = N_Pragma
5731 and then Pragma_Name (N) = Name_Stream_Convert
5733 -- For tagged types this pragma is not inherited, so we
5734 -- must verify that it is defined for the given type and
5738 Entity (Expression (First (Pragma_Argument_Associations (N))));
5740 if not Is_Tagged_Type (T)
5742 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
5752 end Get_Stream_Convert_Pragma;
5754 ---------------------------------
5755 -- Is_Constrained_Packed_Array --
5756 ---------------------------------
5758 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
5759 Arr : Entity_Id := Typ;
5762 if Is_Access_Type (Arr) then
5763 Arr := Designated_Type (Arr);
5766 return Is_Array_Type (Arr)
5767 and then Is_Constrained (Arr)
5768 and then Present (Packed_Array_Type (Arr));
5769 end Is_Constrained_Packed_Array;
5771 ----------------------------------------
5772 -- Is_Inline_Floating_Point_Attribute --
5773 ----------------------------------------
5775 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
5776 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
5779 if Nkind (Parent (N)) /= N_Type_Conversion
5780 or else not Is_Integer_Type (Etype (Parent (N)))
5785 -- Should also support 'Machine_Rounding and 'Unbiased_Rounding, but
5786 -- required back end support has not been implemented yet ???
5788 return Id = Attribute_Truncation;
5789 end Is_Inline_Floating_Point_Attribute;
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