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 -- the 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 Res := Is_Constrained (Underlying_Type (Etype (Ent)));
1651 New_Reference_To (Boolean_Literals (Res), Loc));
1654 -- Prefix is not an entity name. These are also cases where we can
1655 -- always tell at compile time by looking at the form and type of the
1656 -- prefix. If an explicit dereference of an object with constrained
1657 -- partial view, this is unconstrained (Ada 2005 AI-363).
1663 not Is_Variable (Pref)
1665 (Nkind (Pref) = N_Explicit_Dereference
1667 not Has_Constrained_Partial_View (Base_Type (Ptyp)))
1668 or else Is_Constrained (Underlying_Type (Ptyp))),
1672 Analyze_And_Resolve (N, Standard_Boolean);
1679 -- Transforms 'Copy_Sign into a call to the floating-point attribute
1680 -- function Copy_Sign in Fat_xxx (where xxx is the root type)
1682 when Attribute_Copy_Sign =>
1683 Expand_Fpt_Attribute_RR (N);
1689 -- Transforms 'Count attribute into a call to the Count function
1691 when Attribute_Count => Count : declare
1693 Conctyp : Entity_Id;
1695 Entry_Id : Entity_Id;
1700 -- If the prefix is a member of an entry family, retrieve both
1701 -- entry name and index. For a simple entry there is no index.
1703 if Nkind (Pref) = N_Indexed_Component then
1704 Entnam := Prefix (Pref);
1705 Index := First (Expressions (Pref));
1711 Entry_Id := Entity (Entnam);
1713 -- Find the concurrent type in which this attribute is referenced
1714 -- (there had better be one).
1716 Conctyp := Current_Scope;
1717 while not Is_Concurrent_Type (Conctyp) loop
1718 Conctyp := Scope (Conctyp);
1723 if Is_Protected_Type (Conctyp) then
1724 case Corresponding_Runtime_Package (Conctyp) is
1725 when System_Tasking_Protected_Objects_Entries =>
1726 Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
1729 Make_Function_Call (Loc,
1731 Parameter_Associations => New_List (
1733 (Find_Protection_Object (Current_Scope), Loc),
1734 Entry_Index_Expression
1735 (Loc, Entry_Id, Index, Scope (Entry_Id))));
1737 when System_Tasking_Protected_Objects_Single_Entry =>
1739 New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
1742 Make_Function_Call (Loc,
1744 Parameter_Associations => New_List (
1746 (Find_Protection_Object (Current_Scope), Loc)));
1749 raise Program_Error;
1756 Make_Function_Call (Loc,
1757 Name => New_Reference_To (RTE (RE_Task_Count), Loc),
1758 Parameter_Associations => New_List (
1759 Entry_Index_Expression (Loc,
1760 Entry_Id, Index, Scope (Entry_Id))));
1763 -- The call returns type Natural but the context is universal integer
1764 -- so any integer type is allowed. The attribute was already resolved
1765 -- so its Etype is the required result type. If the base type of the
1766 -- context type is other than Standard.Integer we put in a conversion
1767 -- to the required type. This can be a normal typed conversion since
1768 -- both input and output types of the conversion are integer types
1770 if Base_Type (Typ) /= Base_Type (Standard_Integer) then
1771 Rewrite (N, Convert_To (Typ, Call));
1776 Analyze_And_Resolve (N, Typ);
1783 -- This processing is shared by Elab_Spec
1785 -- What we do is to insert the following declarations
1788 -- pragma Import (C, enn, "name___elabb/s");
1790 -- and then the Elab_Body/Spec attribute is replaced by a reference
1791 -- to this defining identifier.
1793 when Attribute_Elab_Body |
1794 Attribute_Elab_Spec =>
1797 Ent : constant Entity_Id := Make_Temporary (Loc, 'E');
1801 procedure Make_Elab_String (Nod : Node_Id);
1802 -- Given Nod, an identifier, or a selected component, put the
1803 -- image into the current string literal, with double underline
1804 -- between components.
1806 ----------------------
1807 -- Make_Elab_String --
1808 ----------------------
1810 procedure Make_Elab_String (Nod : Node_Id) is
1812 if Nkind (Nod) = N_Selected_Component then
1813 Make_Elab_String (Prefix (Nod));
1817 Store_String_Char ('$');
1819 Store_String_Char ('.');
1821 Store_String_Char ('_');
1822 Store_String_Char ('_');
1825 Get_Name_String (Chars (Selector_Name (Nod)));
1828 pragma Assert (Nkind (Nod) = N_Identifier);
1829 Get_Name_String (Chars (Nod));
1832 Store_String_Chars (Name_Buffer (1 .. Name_Len));
1833 end Make_Elab_String;
1835 -- Start of processing for Elab_Body/Elab_Spec
1838 -- First we need to prepare the string literal for the name of
1839 -- the elaboration routine to be referenced.
1842 Make_Elab_String (Pref);
1844 if VM_Target = No_VM then
1845 Store_String_Chars ("___elab");
1846 Lang := Make_Identifier (Loc, Name_C);
1848 Store_String_Chars ("._elab");
1849 Lang := Make_Identifier (Loc, Name_Ada);
1852 if Id = Attribute_Elab_Body then
1853 Store_String_Char ('b');
1855 Store_String_Char ('s');
1860 Insert_Actions (N, New_List (
1861 Make_Subprogram_Declaration (Loc,
1863 Make_Procedure_Specification (Loc,
1864 Defining_Unit_Name => Ent)),
1867 Chars => Name_Import,
1868 Pragma_Argument_Associations => New_List (
1869 Make_Pragma_Argument_Association (Loc,
1870 Expression => Lang),
1872 Make_Pragma_Argument_Association (Loc,
1874 Make_Identifier (Loc, Chars (Ent))),
1876 Make_Pragma_Argument_Association (Loc,
1878 Make_String_Literal (Loc, Str))))));
1880 Set_Entity (N, Ent);
1881 Rewrite (N, New_Occurrence_Of (Ent, Loc));
1888 -- Elaborated is always True for preelaborated units, predefined units,
1889 -- pure units and units which have Elaborate_Body pragmas. These units
1890 -- have no elaboration entity.
1892 -- Note: The Elaborated attribute is never passed to the back end
1894 when Attribute_Elaborated => Elaborated : declare
1895 Ent : constant Entity_Id := Entity (Pref);
1898 if Present (Elaboration_Entity (Ent)) then
1900 New_Occurrence_Of (Elaboration_Entity (Ent), Loc));
1902 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
1910 when Attribute_Enum_Rep => Enum_Rep :
1912 -- X'Enum_Rep (Y) expands to
1916 -- This is simply a direct conversion from the enumeration type to
1917 -- the target integer type, which is treated by the back end as a
1918 -- normal integer conversion, treating the enumeration type as an
1919 -- integer, which is exactly what we want! We set Conversion_OK to
1920 -- make sure that the analyzer does not complain about what otherwise
1921 -- might be an illegal conversion.
1923 if Is_Non_Empty_List (Exprs) then
1925 OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
1927 -- X'Enum_Rep where X is an enumeration literal is replaced by
1928 -- the literal value.
1930 elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
1932 Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
1934 -- If this is a renaming of a literal, recover the representation
1937 elsif Ekind (Entity (Pref)) = E_Constant
1938 and then Present (Renamed_Object (Entity (Pref)))
1940 Ekind (Entity (Renamed_Object (Entity (Pref))))
1941 = E_Enumeration_Literal
1944 Make_Integer_Literal (Loc,
1945 Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
1947 -- X'Enum_Rep where X is an object does a direct unchecked conversion
1948 -- of the object value, as described for the type case above.
1952 OK_Convert_To (Typ, Relocate_Node (Pref)));
1956 Analyze_And_Resolve (N, Typ);
1963 when Attribute_Enum_Val => Enum_Val : declare
1965 Btyp : constant Entity_Id := Base_Type (Ptyp);
1968 -- X'Enum_Val (Y) expands to
1970 -- [constraint_error when _rep_to_pos (Y, False) = -1, msg]
1973 Expr := Unchecked_Convert_To (Ptyp, First (Exprs));
1976 Make_Raise_Constraint_Error (Loc,
1980 Make_Function_Call (Loc,
1982 New_Reference_To (TSS (Btyp, TSS_Rep_To_Pos), Loc),
1983 Parameter_Associations => New_List (
1984 Relocate_Node (Duplicate_Subexpr (Expr)),
1985 New_Occurrence_Of (Standard_False, Loc))),
1987 Right_Opnd => Make_Integer_Literal (Loc, -1)),
1988 Reason => CE_Range_Check_Failed));
1991 Analyze_And_Resolve (N, Ptyp);
1998 -- Transforms 'Exponent into a call to the floating-point attribute
1999 -- function Exponent in Fat_xxx (where xxx is the root type)
2001 when Attribute_Exponent =>
2002 Expand_Fpt_Attribute_R (N);
2008 -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag)
2010 when Attribute_External_Tag => External_Tag :
2013 Make_Function_Call (Loc,
2014 Name => New_Reference_To (RTE (RE_External_Tag), Loc),
2015 Parameter_Associations => New_List (
2016 Make_Attribute_Reference (Loc,
2017 Attribute_Name => Name_Tag,
2018 Prefix => Prefix (N)))));
2020 Analyze_And_Resolve (N, Standard_String);
2027 when Attribute_First =>
2029 -- If the prefix type is a constrained packed array type which
2030 -- already has a Packed_Array_Type representation defined, then
2031 -- replace this attribute with a direct reference to 'First of the
2032 -- appropriate index subtype (since otherwise the back end will try
2033 -- to give us the value of 'First for this implementation type).
2035 if Is_Constrained_Packed_Array (Ptyp) then
2037 Make_Attribute_Reference (Loc,
2038 Attribute_Name => Name_First,
2039 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2040 Analyze_And_Resolve (N, Typ);
2042 elsif Is_Access_Type (Ptyp) then
2043 Apply_Access_Check (N);
2050 -- Compute this if component clause was present, otherwise we leave the
2051 -- computation to be completed in the back-end, since we don't know what
2052 -- layout will be chosen.
2054 when Attribute_First_Bit => First_Bit : declare
2055 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2058 if Known_Static_Component_Bit_Offset (CE) then
2060 Make_Integer_Literal (Loc,
2061 Component_Bit_Offset (CE) mod System_Storage_Unit));
2063 Analyze_And_Resolve (N, Typ);
2066 Apply_Universal_Integer_Attribute_Checks (N);
2076 -- fixtype'Fixed_Value (integer-value)
2080 -- fixtype(integer-value)
2082 -- We do all the required analysis of the conversion here, because we do
2083 -- not want this to go through the fixed-point conversion circuits. Note
2084 -- that the back end always treats fixed-point as equivalent to the
2085 -- corresponding integer type anyway.
2087 when Attribute_Fixed_Value => Fixed_Value :
2090 Make_Type_Conversion (Loc,
2091 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2092 Expression => Relocate_Node (First (Exprs))));
2093 Set_Etype (N, Entity (Pref));
2096 -- Note: it might appear that a properly analyzed unchecked conversion
2097 -- would be just fine here, but that's not the case, since the full
2098 -- range checks performed by the following call are critical!
2100 Apply_Type_Conversion_Checks (N);
2107 -- Transforms 'Floor into a call to the floating-point attribute
2108 -- function Floor in Fat_xxx (where xxx is the root type)
2110 when Attribute_Floor =>
2111 Expand_Fpt_Attribute_R (N);
2117 -- For the fixed-point type Typ:
2123 -- Result_Type (System.Fore (Universal_Real (Type'First)),
2124 -- Universal_Real (Type'Last))
2126 -- Note that we know that the type is a non-static subtype, or Fore
2127 -- would have itself been computed dynamically in Eval_Attribute.
2129 when Attribute_Fore => Fore : begin
2132 Make_Function_Call (Loc,
2133 Name => New_Reference_To (RTE (RE_Fore), Loc),
2135 Parameter_Associations => New_List (
2136 Convert_To (Universal_Real,
2137 Make_Attribute_Reference (Loc,
2138 Prefix => New_Reference_To (Ptyp, Loc),
2139 Attribute_Name => Name_First)),
2141 Convert_To (Universal_Real,
2142 Make_Attribute_Reference (Loc,
2143 Prefix => New_Reference_To (Ptyp, Loc),
2144 Attribute_Name => Name_Last))))));
2146 Analyze_And_Resolve (N, Typ);
2153 -- Transforms 'Fraction into a call to the floating-point attribute
2154 -- function Fraction in Fat_xxx (where xxx is the root type)
2156 when Attribute_Fraction =>
2157 Expand_Fpt_Attribute_R (N);
2163 when Attribute_From_Any => From_Any : declare
2164 P_Type : constant Entity_Id := Etype (Pref);
2165 Decls : constant List_Id := New_List;
2168 Build_From_Any_Call (P_Type,
2169 Relocate_Node (First (Exprs)),
2171 Insert_Actions (N, Decls);
2172 Analyze_And_Resolve (N, P_Type);
2179 -- For an exception returns a reference to the exception data:
2180 -- Exception_Id!(Prefix'Reference)
2182 -- For a task it returns a reference to the _task_id component of
2183 -- corresponding record:
2185 -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined
2187 -- in Ada.Task_Identification
2189 when Attribute_Identity => Identity : declare
2190 Id_Kind : Entity_Id;
2193 if Ptyp = Standard_Exception_Type then
2194 Id_Kind := RTE (RE_Exception_Id);
2196 if Present (Renamed_Object (Entity (Pref))) then
2197 Set_Entity (Pref, Renamed_Object (Entity (Pref)));
2201 Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
2203 Id_Kind := RTE (RO_AT_Task_Id);
2205 -- If the prefix is a task interface, the Task_Id is obtained
2206 -- dynamically through a dispatching call, as for other task
2207 -- attributes applied to interfaces.
2209 if Ada_Version >= Ada_2005
2210 and then Ekind (Ptyp) = E_Class_Wide_Type
2211 and then Is_Interface (Ptyp)
2212 and then Is_Task_Interface (Ptyp)
2215 Unchecked_Convert_To (Id_Kind,
2216 Make_Selected_Component (Loc,
2218 New_Copy_Tree (Pref),
2220 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))));
2224 Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
2228 Analyze_And_Resolve (N, Id_Kind);
2235 -- Image attribute is handled in separate unit Exp_Imgv
2237 when Attribute_Image =>
2238 Exp_Imgv.Expand_Image_Attribute (N);
2244 -- X'Img is expanded to typ'Image (X), where typ is the type of X
2246 when Attribute_Img => Img :
2249 Make_Attribute_Reference (Loc,
2250 Prefix => New_Reference_To (Ptyp, Loc),
2251 Attribute_Name => Name_Image,
2252 Expressions => New_List (Relocate_Node (Pref))));
2254 Analyze_And_Resolve (N, Standard_String);
2261 when Attribute_Input => Input : declare
2262 P_Type : constant Entity_Id := Entity (Pref);
2263 B_Type : constant Entity_Id := Base_Type (P_Type);
2264 U_Type : constant Entity_Id := Underlying_Type (P_Type);
2265 Strm : constant Node_Id := First (Exprs);
2273 Cntrl : Node_Id := Empty;
2274 -- Value for controlling argument in call. Always Empty except in
2275 -- the dispatching (class-wide type) case, where it is a reference
2276 -- to the dummy object initialized to the right internal tag.
2278 procedure Freeze_Stream_Subprogram (F : Entity_Id);
2279 -- The expansion of the attribute reference may generate a call to
2280 -- a user-defined stream subprogram that is frozen by the call. This
2281 -- can lead to access-before-elaboration problem if the reference
2282 -- appears in an object declaration and the subprogram body has not
2283 -- been seen. The freezing of the subprogram requires special code
2284 -- because it appears in an expanded context where expressions do
2285 -- not freeze their constituents.
2287 ------------------------------
2288 -- Freeze_Stream_Subprogram --
2289 ------------------------------
2291 procedure Freeze_Stream_Subprogram (F : Entity_Id) is
2292 Decl : constant Node_Id := Unit_Declaration_Node (F);
2296 -- If this is user-defined subprogram, the corresponding
2297 -- stream function appears as a renaming-as-body, and the
2298 -- user subprogram must be retrieved by tree traversal.
2301 and then Nkind (Decl) = N_Subprogram_Declaration
2302 and then Present (Corresponding_Body (Decl))
2304 Bod := Corresponding_Body (Decl);
2306 if Nkind (Unit_Declaration_Node (Bod)) =
2307 N_Subprogram_Renaming_Declaration
2309 Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod))));
2312 end Freeze_Stream_Subprogram;
2314 -- Start of processing for Input
2317 -- If no underlying type, we have an error that will be diagnosed
2318 -- elsewhere, so here we just completely ignore the expansion.
2324 -- If there is a TSS for Input, just call it
2326 Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
2328 if Present (Fname) then
2332 -- If there is a Stream_Convert pragma, use it, we rewrite
2334 -- sourcetyp'Input (stream)
2338 -- sourcetyp (streamread (strmtyp'Input (stream)));
2340 -- where streamread is the given Read function that converts an
2341 -- argument of type strmtyp to type sourcetyp or a type from which
2342 -- it is derived (extra conversion required for the derived case).
2344 Prag := Get_Stream_Convert_Pragma (P_Type);
2346 if Present (Prag) then
2347 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
2348 Rfunc := Entity (Expression (Arg2));
2352 Make_Function_Call (Loc,
2353 Name => New_Occurrence_Of (Rfunc, Loc),
2354 Parameter_Associations => New_List (
2355 Make_Attribute_Reference (Loc,
2358 (Etype (First_Formal (Rfunc)), Loc),
2359 Attribute_Name => Name_Input,
2360 Expressions => Exprs)))));
2362 Analyze_And_Resolve (N, B_Type);
2367 elsif Is_Elementary_Type (U_Type) then
2369 -- A special case arises if we have a defined _Read routine,
2370 -- since in this case we are required to call this routine.
2372 if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
2373 Build_Record_Or_Elementary_Input_Function
2374 (Loc, U_Type, Decl, Fname);
2375 Insert_Action (N, Decl);
2377 -- For normal cases, we call the I_xxx routine directly
2380 Rewrite (N, Build_Elementary_Input_Call (N));
2381 Analyze_And_Resolve (N, P_Type);
2387 elsif Is_Array_Type (U_Type) then
2388 Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
2389 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
2391 -- Dispatching case with class-wide type
2393 elsif Is_Class_Wide_Type (P_Type) then
2395 -- No need to do anything else compiling under restriction
2396 -- No_Dispatching_Calls. During the semantic analysis we
2397 -- already notified such violation.
2399 if Restriction_Active (No_Dispatching_Calls) then
2404 Rtyp : constant Entity_Id := Root_Type (P_Type);
2410 -- Read the internal tag (RM 13.13.2(34)) and use it to
2411 -- initialize a dummy tag object:
2413 -- Dnn : Ada.Tags.Tag :=
2414 -- Descendant_Tag (String'Input (Strm), P_Type);
2416 -- This dummy object is used only to provide a controlling
2417 -- argument for the eventual _Input call. Descendant_Tag is
2418 -- called rather than Internal_Tag to ensure that we have a
2419 -- tag for a type that is descended from the prefix type and
2420 -- declared at the same accessibility level (the exception
2421 -- Tag_Error will be raised otherwise). The level check is
2422 -- required for Ada 2005 because tagged types can be
2423 -- extended in nested scopes (AI-344).
2426 Make_Function_Call (Loc,
2428 New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc),
2429 Parameter_Associations => New_List (
2430 Make_Attribute_Reference (Loc,
2431 Prefix => New_Occurrence_Of (Standard_String, Loc),
2432 Attribute_Name => Name_Input,
2433 Expressions => New_List (
2434 Relocate_Node (Duplicate_Subexpr (Strm)))),
2435 Make_Attribute_Reference (Loc,
2436 Prefix => New_Reference_To (P_Type, Loc),
2437 Attribute_Name => Name_Tag)));
2439 Dnn := Make_Temporary (Loc, 'D', Expr);
2442 Make_Object_Declaration (Loc,
2443 Defining_Identifier => Dnn,
2444 Object_Definition =>
2445 New_Occurrence_Of (RTE (RE_Tag), Loc),
2446 Expression => Expr);
2448 Insert_Action (N, Decl);
2450 -- Now we need to get the entity for the call, and construct
2451 -- a function call node, where we preset a reference to Dnn
2452 -- as the controlling argument (doing an unchecked convert
2453 -- to the class-wide tagged type to make it look like a real
2456 Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
2458 Unchecked_Convert_To (P_Type,
2459 New_Occurrence_Of (Dnn, Loc));
2460 Set_Etype (Cntrl, P_Type);
2461 Set_Parent (Cntrl, N);
2464 -- For tagged types, use the primitive Input function
2466 elsif Is_Tagged_Type (U_Type) then
2467 Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
2469 -- All other record type cases, including protected records. The
2470 -- latter only arise for expander generated code for handling
2471 -- shared passive partition access.
2475 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
2477 -- Ada 2005 (AI-216): Program_Error is raised executing default
2478 -- implementation of the Input attribute of an unchecked union
2479 -- type if the type lacks default discriminant values.
2481 if Is_Unchecked_Union (Base_Type (U_Type))
2482 and then No (Discriminant_Constraint (U_Type))
2485 Make_Raise_Program_Error (Loc,
2486 Reason => PE_Unchecked_Union_Restriction));
2491 Build_Record_Or_Elementary_Input_Function
2492 (Loc, Base_Type (U_Type), Decl, Fname);
2493 Insert_Action (N, Decl);
2495 if Nkind (Parent (N)) = N_Object_Declaration
2496 and then Is_Record_Type (U_Type)
2498 -- The stream function may contain calls to user-defined
2499 -- Read procedures for individual components.
2506 Comp := First_Component (U_Type);
2507 while Present (Comp) loop
2509 Find_Stream_Subprogram
2510 (Etype (Comp), TSS_Stream_Read);
2512 if Present (Func) then
2513 Freeze_Stream_Subprogram (Func);
2516 Next_Component (Comp);
2523 -- If we fall through, Fname is the function to be called. The result
2524 -- is obtained by calling the appropriate function, then converting
2525 -- the result. The conversion does a subtype check.
2528 Make_Function_Call (Loc,
2529 Name => New_Occurrence_Of (Fname, Loc),
2530 Parameter_Associations => New_List (
2531 Relocate_Node (Strm)));
2533 Set_Controlling_Argument (Call, Cntrl);
2534 Rewrite (N, Unchecked_Convert_To (P_Type, Call));
2535 Analyze_And_Resolve (N, P_Type);
2537 if Nkind (Parent (N)) = N_Object_Declaration then
2538 Freeze_Stream_Subprogram (Fname);
2548 -- inttype'Fixed_Value (fixed-value)
2552 -- inttype(integer-value))
2554 -- we do all the required analysis of the conversion here, because we do
2555 -- not want this to go through the fixed-point conversion circuits. Note
2556 -- that the back end always treats fixed-point as equivalent to the
2557 -- corresponding integer type anyway.
2559 when Attribute_Integer_Value => Integer_Value :
2562 Make_Type_Conversion (Loc,
2563 Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
2564 Expression => Relocate_Node (First (Exprs))));
2565 Set_Etype (N, Entity (Pref));
2568 -- Note: it might appear that a properly analyzed unchecked conversion
2569 -- would be just fine here, but that's not the case, since the full
2570 -- range checks performed by the following call are critical!
2572 Apply_Type_Conversion_Checks (N);
2579 when Attribute_Invalid_Value =>
2580 Rewrite (N, Get_Simple_Init_Val (Ptyp, N));
2586 when Attribute_Last =>
2588 -- If the prefix type is a constrained packed array type which
2589 -- already has a Packed_Array_Type representation defined, then
2590 -- replace this attribute with a direct reference to 'Last of the
2591 -- appropriate index subtype (since otherwise the back end will try
2592 -- to give us the value of 'Last for this implementation type).
2594 if Is_Constrained_Packed_Array (Ptyp) then
2596 Make_Attribute_Reference (Loc,
2597 Attribute_Name => Name_Last,
2598 Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
2599 Analyze_And_Resolve (N, Typ);
2601 elsif Is_Access_Type (Ptyp) then
2602 Apply_Access_Check (N);
2609 -- We compute this if a component clause was present, otherwise we leave
2610 -- the computation up to the back end, since we don't know what layout
2613 when Attribute_Last_Bit => Last_Bit : declare
2614 CE : constant Entity_Id := Entity (Selector_Name (Pref));
2617 if Known_Static_Component_Bit_Offset (CE)
2618 and then Known_Static_Esize (CE)
2621 Make_Integer_Literal (Loc,
2622 Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
2625 Analyze_And_Resolve (N, Typ);
2628 Apply_Universal_Integer_Attribute_Checks (N);
2636 -- Transforms 'Leading_Part into a call to the floating-point attribute
2637 -- function Leading_Part in Fat_xxx (where xxx is the root type)
2639 -- Note: strictly, we should generate special case code to deal with
2640 -- absurdly large positive arguments (greater than Integer'Last), which
2641 -- result in returning the first argument unchanged, but it hardly seems
2642 -- worth the effort. We raise constraint error for absurdly negative
2643 -- arguments which is fine.
2645 when Attribute_Leading_Part =>
2646 Expand_Fpt_Attribute_RI (N);
2652 when Attribute_Length => declare
2657 -- Processing for packed array types
2659 if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
2660 Ityp := Get_Index_Subtype (N);
2662 -- If the index type, Ityp, is an enumeration type with holes,
2663 -- then we calculate X'Length explicitly using
2666 -- (0, Ityp'Pos (X'Last (N)) -
2667 -- Ityp'Pos (X'First (N)) + 1);
2669 -- Since the bounds in the template are the representation values
2670 -- and the back end would get the wrong value.
2672 if Is_Enumeration_Type (Ityp)
2673 and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
2678 Xnum := Expr_Value (First (Expressions (N)));
2682 Make_Attribute_Reference (Loc,
2683 Prefix => New_Occurrence_Of (Typ, Loc),
2684 Attribute_Name => Name_Max,
2685 Expressions => New_List
2686 (Make_Integer_Literal (Loc, 0),
2690 Make_Op_Subtract (Loc,
2692 Make_Attribute_Reference (Loc,
2693 Prefix => New_Occurrence_Of (Ityp, Loc),
2694 Attribute_Name => Name_Pos,
2696 Expressions => New_List (
2697 Make_Attribute_Reference (Loc,
2698 Prefix => Duplicate_Subexpr (Pref),
2699 Attribute_Name => Name_Last,
2700 Expressions => New_List (
2701 Make_Integer_Literal (Loc, Xnum))))),
2704 Make_Attribute_Reference (Loc,
2705 Prefix => New_Occurrence_Of (Ityp, Loc),
2706 Attribute_Name => Name_Pos,
2708 Expressions => New_List (
2709 Make_Attribute_Reference (Loc,
2711 Duplicate_Subexpr_No_Checks (Pref),
2712 Attribute_Name => Name_First,
2713 Expressions => New_List (
2714 Make_Integer_Literal (Loc, Xnum)))))),
2716 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
2718 Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
2721 -- If the prefix type is a constrained packed array type which
2722 -- already has a Packed_Array_Type representation defined, then
2723 -- replace this attribute with a direct reference to 'Range_Length
2724 -- of the appropriate index subtype (since otherwise the back end
2725 -- will try to give us the value of 'Length for this
2726 -- implementation type).
2728 elsif Is_Constrained (Ptyp) then
2730 Make_Attribute_Reference (Loc,
2731 Attribute_Name => Name_Range_Length,
2732 Prefix => New_Reference_To (Ityp, Loc)));
2733 Analyze_And_Resolve (N, Typ);
2738 elsif Is_Access_Type (Ptyp) then
2739 Apply_Access_Check (N);
2741 -- If the designated type is a packed array type, then we convert
2742 -- the reference to:
2745 -- xtyp'Pos (Pref'Last (Expr)) -
2746 -- xtyp'Pos (Pref'First (Expr)));
2748 -- This is a bit complex, but it is the easiest thing to do that
2749 -- works in all cases including enum types with holes xtyp here
2750 -- is the appropriate index type.
2753 Dtyp : constant Entity_Id := Designated_Type (Ptyp);
2757 if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
2758 Xtyp := Get_Index_Subtype (N);
2761 Make_Attribute_Reference (Loc,
2762 Prefix => New_Occurrence_Of (Typ, Loc),
2763 Attribute_Name => Name_Max,
2764 Expressions => New_List (
2765 Make_Integer_Literal (Loc, 0),
2768 Make_Integer_Literal (Loc, 1),
2769 Make_Op_Subtract (Loc,
2771 Make_Attribute_Reference (Loc,
2772 Prefix => New_Occurrence_Of (Xtyp, Loc),
2773 Attribute_Name => Name_Pos,
2774 Expressions => New_List (
2775 Make_Attribute_Reference (Loc,
2776 Prefix => Duplicate_Subexpr (Pref),
2777 Attribute_Name => Name_Last,
2779 New_Copy_List (Exprs)))),
2782 Make_Attribute_Reference (Loc,
2783 Prefix => New_Occurrence_Of (Xtyp, Loc),
2784 Attribute_Name => Name_Pos,
2785 Expressions => New_List (
2786 Make_Attribute_Reference (Loc,
2788 Duplicate_Subexpr_No_Checks (Pref),
2789 Attribute_Name => Name_First,
2791 New_Copy_List (Exprs)))))))));
2793 Analyze_And_Resolve (N, Typ);
2797 -- Otherwise leave it to the back end
2800 Apply_Universal_Integer_Attribute_Checks (N);
2808 -- Transforms 'Machine into a call to the floating-point attribute
2809 -- function Machine in Fat_xxx (where xxx is the root type)
2811 when Attribute_Machine =>
2812 Expand_Fpt_Attribute_R (N);
2814 ----------------------
2815 -- Machine_Rounding --
2816 ----------------------
2818 -- Transforms 'Machine_Rounding into a call to the floating-point
2819 -- attribute function Machine_Rounding in Fat_xxx (where xxx is the root
2820 -- type). Expansion is avoided for cases the back end can handle
2823 when Attribute_Machine_Rounding =>
2824 if not Is_Inline_Floating_Point_Attribute (N) then
2825 Expand_Fpt_Attribute_R (N);
2832 -- Machine_Size is equivalent to Object_Size, so transform it into
2833 -- Object_Size and that way the back end never sees Machine_Size.
2835 when Attribute_Machine_Size =>
2837 Make_Attribute_Reference (Loc,
2838 Prefix => Prefix (N),
2839 Attribute_Name => Name_Object_Size));
2841 Analyze_And_Resolve (N, Typ);
2847 -- The only case that can get this far is the dynamic case of the old
2848 -- Ada 83 Mantissa attribute for the fixed-point case. For this case,
2855 -- ityp (System.Mantissa.Mantissa_Value
2856 -- (Integer'Integer_Value (typ'First),
2857 -- Integer'Integer_Value (typ'Last)));
2859 when Attribute_Mantissa => Mantissa : begin
2862 Make_Function_Call (Loc,
2863 Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
2865 Parameter_Associations => New_List (
2867 Make_Attribute_Reference (Loc,
2868 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2869 Attribute_Name => Name_Integer_Value,
2870 Expressions => New_List (
2872 Make_Attribute_Reference (Loc,
2873 Prefix => New_Occurrence_Of (Ptyp, Loc),
2874 Attribute_Name => Name_First))),
2876 Make_Attribute_Reference (Loc,
2877 Prefix => New_Occurrence_Of (Standard_Integer, Loc),
2878 Attribute_Name => Name_Integer_Value,
2879 Expressions => New_List (
2881 Make_Attribute_Reference (Loc,
2882 Prefix => New_Occurrence_Of (Ptyp, Loc),
2883 Attribute_Name => Name_Last)))))));
2885 Analyze_And_Resolve (N, Typ);
2888 --------------------
2889 -- Mechanism_Code --
2890 --------------------
2892 when Attribute_Mechanism_Code =>
2894 -- We must replace the prefix in the renamed case
2896 if Is_Entity_Name (Pref)
2897 and then Present (Alias (Entity (Pref)))
2899 Set_Renamed_Subprogram (Pref, Alias (Entity (Pref)));
2906 when Attribute_Mod => Mod_Case : declare
2907 Arg : constant Node_Id := Relocate_Node (First (Exprs));
2908 Hi : constant Node_Id := Type_High_Bound (Etype (Arg));
2909 Modv : constant Uint := Modulus (Btyp);
2913 -- This is not so simple. The issue is what type to use for the
2914 -- computation of the modular value.
2916 -- The easy case is when the modulus value is within the bounds
2917 -- of the signed integer type of the argument. In this case we can
2918 -- just do the computation in that signed integer type, and then
2919 -- do an ordinary conversion to the target type.
2921 if Modv <= Expr_Value (Hi) then
2926 Right_Opnd => Make_Integer_Literal (Loc, Modv))));
2928 -- Here we know that the modulus is larger than type'Last of the
2929 -- integer type. There are two cases to consider:
2931 -- a) The integer value is non-negative. In this case, it is
2932 -- returned as the result (since it is less than the modulus).
2934 -- b) The integer value is negative. In this case, we know that the
2935 -- result is modulus + value, where the value might be as small as
2936 -- -modulus. The trouble is what type do we use to do the subtract.
2937 -- No type will do, since modulus can be as big as 2**64, and no
2938 -- integer type accommodates this value. Let's do bit of algebra
2941 -- = modulus - (-value)
2942 -- = (modulus - 1) - (-value - 1)
2944 -- Now modulus - 1 is certainly in range of the modular type.
2945 -- -value is in the range 1 .. modulus, so -value -1 is in the
2946 -- range 0 .. modulus-1 which is in range of the modular type.
2947 -- Furthermore, (-value - 1) can be expressed as -(value + 1)
2948 -- which we can compute using the integer base type.
2950 -- Once this is done we analyze the conditional expression without
2951 -- range checks, because we know everything is in range, and we
2952 -- want to prevent spurious warnings on either branch.
2956 Make_Conditional_Expression (Loc,
2957 Expressions => New_List (
2959 Left_Opnd => Duplicate_Subexpr (Arg),
2960 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2963 Duplicate_Subexpr_No_Checks (Arg)),
2965 Make_Op_Subtract (Loc,
2967 Make_Integer_Literal (Loc,
2968 Intval => Modv - 1),
2974 Left_Opnd => Duplicate_Subexpr_No_Checks (Arg),
2976 Make_Integer_Literal (Loc,
2977 Intval => 1))))))));
2981 Analyze_And_Resolve (N, Btyp, Suppress => All_Checks);
2988 -- Transforms 'Model into a call to the floating-point attribute
2989 -- function Model in Fat_xxx (where xxx is the root type)
2991 when Attribute_Model =>
2992 Expand_Fpt_Attribute_R (N);
2998 -- The processing for Object_Size shares the processing for Size
3004 when Attribute_Old => Old : declare
3005 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', Pref);
3010 -- Find the nearest subprogram body, ignoring _Preconditions
3014 Subp := Parent (Subp);
3015 exit when Nkind (Subp) = N_Subprogram_Body
3016 and then Chars (Defining_Entity (Subp)) /= Name_uPostconditions;
3019 -- Insert the initialized object declaration at the start of the
3020 -- subprogram's declarations.
3023 Make_Object_Declaration (Loc,
3024 Defining_Identifier => Tnn,
3025 Constant_Present => True,
3026 Object_Definition => New_Occurrence_Of (Etype (N), Loc),
3027 Expression => Pref);
3029 -- Push the subprogram's scope, so that the object will be analyzed
3030 -- in that context (rather than the context of the Precondition
3031 -- subprogram) and will have its Scope set properly.
3033 if Present (Corresponding_Spec (Subp)) then
3034 Push_Scope (Corresponding_Spec (Subp));
3036 Push_Scope (Defining_Entity (Subp));
3039 if Is_Empty_List (Declarations (Subp)) then
3040 Set_Declarations (Subp, New_List (Asn_Stm));
3043 Insert_Action (First (Declarations (Subp)), Asn_Stm);
3048 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
3055 when Attribute_Output => Output : declare
3056 P_Type : constant Entity_Id := Entity (Pref);
3057 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3065 -- If no underlying type, we have an error that will be diagnosed
3066 -- elsewhere, so here we just completely ignore the expansion.
3072 -- If TSS for Output is present, just call it
3074 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
3076 if Present (Pname) then
3080 -- If there is a Stream_Convert pragma, use it, we rewrite
3082 -- sourcetyp'Output (stream, Item)
3086 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
3088 -- where strmwrite is the given Write function that converts an
3089 -- argument of type sourcetyp or a type acctyp, from which it is
3090 -- derived to type strmtyp. The conversion to acttyp is required
3091 -- for the derived case.
3093 Prag := Get_Stream_Convert_Pragma (P_Type);
3095 if Present (Prag) then
3097 Next (Next (First (Pragma_Argument_Associations (Prag))));
3098 Wfunc := Entity (Expression (Arg3));
3101 Make_Attribute_Reference (Loc,
3102 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
3103 Attribute_Name => Name_Output,
3104 Expressions => New_List (
3105 Relocate_Node (First (Exprs)),
3106 Make_Function_Call (Loc,
3107 Name => New_Occurrence_Of (Wfunc, Loc),
3108 Parameter_Associations => New_List (
3109 OK_Convert_To (Etype (First_Formal (Wfunc)),
3110 Relocate_Node (Next (First (Exprs)))))))));
3115 -- For elementary types, we call the W_xxx routine directly.
3116 -- Note that the effect of Write and Output is identical for
3117 -- the case of an elementary type, since there are no
3118 -- discriminants or bounds.
3120 elsif Is_Elementary_Type (U_Type) then
3122 -- A special case arises if we have a defined _Write routine,
3123 -- since in this case we are required to call this routine.
3125 if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
3126 Build_Record_Or_Elementary_Output_Procedure
3127 (Loc, U_Type, Decl, Pname);
3128 Insert_Action (N, Decl);
3130 -- For normal cases, we call the W_xxx routine directly
3133 Rewrite (N, Build_Elementary_Write_Call (N));
3140 elsif Is_Array_Type (U_Type) then
3141 Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
3142 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3144 -- Class-wide case, first output external tag, then dispatch
3145 -- to the appropriate primitive Output function (RM 13.13.2(31)).
3147 elsif Is_Class_Wide_Type (P_Type) then
3149 -- No need to do anything else compiling under restriction
3150 -- No_Dispatching_Calls. During the semantic analysis we
3151 -- already notified such violation.
3153 if Restriction_Active (No_Dispatching_Calls) then
3158 Strm : constant Node_Id := First (Exprs);
3159 Item : constant Node_Id := Next (Strm);
3162 -- Ada 2005 (AI-344): Check that the accessibility level
3163 -- of the type of the output object is not deeper than
3164 -- that of the attribute's prefix type.
3166 -- if Get_Access_Level (Item'Tag)
3167 -- /= Get_Access_Level (P_Type'Tag)
3172 -- String'Output (Strm, External_Tag (Item'Tag));
3174 -- We cannot figure out a practical way to implement this
3175 -- accessibility check on virtual machines, so we omit it.
3177 if Ada_Version >= Ada_2005
3178 and then Tagged_Type_Expansion
3181 Make_Implicit_If_Statement (N,
3185 Build_Get_Access_Level (Loc,
3186 Make_Attribute_Reference (Loc,
3189 Duplicate_Subexpr (Item,
3191 Attribute_Name => Name_Tag)),
3194 Make_Integer_Literal (Loc,
3195 Type_Access_Level (P_Type))),
3198 New_List (Make_Raise_Statement (Loc,
3200 RTE (RE_Tag_Error), Loc)))));
3204 Make_Attribute_Reference (Loc,
3205 Prefix => New_Occurrence_Of (Standard_String, Loc),
3206 Attribute_Name => Name_Output,
3207 Expressions => New_List (
3208 Relocate_Node (Duplicate_Subexpr (Strm)),
3209 Make_Function_Call (Loc,
3211 New_Occurrence_Of (RTE (RE_External_Tag), Loc),
3212 Parameter_Associations => New_List (
3213 Make_Attribute_Reference (Loc,
3216 (Duplicate_Subexpr (Item, Name_Req => True)),
3217 Attribute_Name => Name_Tag))))));
3220 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3222 -- Tagged type case, use the primitive Output function
3224 elsif Is_Tagged_Type (U_Type) then
3225 Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
3227 -- All other record type cases, including protected records.
3228 -- The latter only arise for expander generated code for
3229 -- handling shared passive partition access.
3233 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3235 -- Ada 2005 (AI-216): Program_Error is raised when executing
3236 -- the default implementation of the Output attribute of an
3237 -- unchecked union type if the type lacks default discriminant
3240 if Is_Unchecked_Union (Base_Type (U_Type))
3241 and then No (Discriminant_Constraint (U_Type))
3244 Make_Raise_Program_Error (Loc,
3245 Reason => PE_Unchecked_Union_Restriction));
3250 Build_Record_Or_Elementary_Output_Procedure
3251 (Loc, Base_Type (U_Type), Decl, Pname);
3252 Insert_Action (N, Decl);
3256 -- If we fall through, Pname is the name of the procedure to call
3258 Rewrite_Stream_Proc_Call (Pname);
3265 -- For enumeration types with a standard representation, Pos is
3266 -- handled by the back end.
3268 -- For enumeration types, with a non-standard representation we generate
3269 -- a call to the _Rep_To_Pos function created when the type was frozen.
3270 -- The call has the form
3272 -- _rep_to_pos (expr, flag)
3274 -- The parameter flag is True if range checks are enabled, causing
3275 -- Program_Error to be raised if the expression has an invalid
3276 -- representation, and False if range checks are suppressed.
3278 -- For integer types, Pos is equivalent to a simple integer
3279 -- conversion and we rewrite it as such
3281 when Attribute_Pos => Pos :
3283 Etyp : Entity_Id := Base_Type (Entity (Pref));
3286 -- Deal with zero/non-zero boolean values
3288 if Is_Boolean_Type (Etyp) then
3289 Adjust_Condition (First (Exprs));
3290 Etyp := Standard_Boolean;
3291 Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
3294 -- Case of enumeration type
3296 if Is_Enumeration_Type (Etyp) then
3298 -- Non-standard enumeration type (generate call)
3300 if Present (Enum_Pos_To_Rep (Etyp)) then
3301 Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
3304 Make_Function_Call (Loc,
3306 New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3307 Parameter_Associations => Exprs)));
3309 Analyze_And_Resolve (N, Typ);
3311 -- Standard enumeration type (do universal integer check)
3314 Apply_Universal_Integer_Attribute_Checks (N);
3317 -- Deal with integer types (replace by conversion)
3319 elsif Is_Integer_Type (Etyp) then
3320 Rewrite (N, Convert_To (Typ, First (Exprs)));
3321 Analyze_And_Resolve (N, Typ);
3330 -- We compute this if a component clause was present, otherwise we leave
3331 -- the computation up to the back end, since we don't know what layout
3334 when Attribute_Position => Position :
3336 CE : constant Entity_Id := Entity (Selector_Name (Pref));
3339 if Present (Component_Clause (CE)) then
3341 Make_Integer_Literal (Loc,
3342 Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
3343 Analyze_And_Resolve (N, Typ);
3346 Apply_Universal_Integer_Attribute_Checks (N);
3354 -- 1. Deal with enumeration types with holes
3355 -- 2. For floating-point, generate call to attribute function
3356 -- 3. For other cases, deal with constraint checking
3358 when Attribute_Pred => Pred :
3360 Etyp : constant Entity_Id := Base_Type (Ptyp);
3364 -- For enumeration types with non-standard representations, we
3365 -- expand typ'Pred (x) into
3367 -- Pos_To_Rep (Rep_To_Pos (x) - 1)
3369 -- If the representation is contiguous, we compute instead
3370 -- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
3371 -- The conversion function Enum_Pos_To_Rep is defined on the
3372 -- base type, not the subtype, so we have to use the base type
3373 -- explicitly for this and other enumeration attributes.
3375 if Is_Enumeration_Type (Ptyp)
3376 and then Present (Enum_Pos_To_Rep (Etyp))
3378 if Has_Contiguous_Rep (Etyp) then
3380 Unchecked_Convert_To (Ptyp,
3383 Make_Integer_Literal (Loc,
3384 Enumeration_Rep (First_Literal (Ptyp))),
3386 Make_Function_Call (Loc,
3389 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3391 Parameter_Associations =>
3393 Unchecked_Convert_To (Ptyp,
3394 Make_Op_Subtract (Loc,
3396 Unchecked_Convert_To (Standard_Integer,
3397 Relocate_Node (First (Exprs))),
3399 Make_Integer_Literal (Loc, 1))),
3400 Rep_To_Pos_Flag (Ptyp, Loc))))));
3403 -- Add Boolean parameter True, to request program errror if
3404 -- we have a bad representation on our hands. If checks are
3405 -- suppressed, then add False instead
3407 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
3409 Make_Indexed_Component (Loc,
3412 (Enum_Pos_To_Rep (Etyp), Loc),
3413 Expressions => New_List (
3414 Make_Op_Subtract (Loc,
3416 Make_Function_Call (Loc,
3419 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
3420 Parameter_Associations => Exprs),
3421 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
3424 Analyze_And_Resolve (N, Typ);
3426 -- For floating-point, we transform 'Pred into a call to the Pred
3427 -- floating-point attribute function in Fat_xxx (xxx is root type)
3429 elsif Is_Floating_Point_Type (Ptyp) then
3430 Expand_Fpt_Attribute_R (N);
3431 Analyze_And_Resolve (N, Typ);
3433 -- For modular types, nothing to do (no overflow, since wraps)
3435 elsif Is_Modular_Integer_Type (Ptyp) then
3438 -- For other types, if argument is marked as needing a range check or
3439 -- overflow checking is enabled, we must generate a check.
3441 elsif not Overflow_Checks_Suppressed (Ptyp)
3442 or else Do_Range_Check (First (Exprs))
3444 Set_Do_Range_Check (First (Exprs), False);
3445 Expand_Pred_Succ (N);
3453 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3455 -- We rewrite X'Priority as the following run-time call:
3457 -- Get_Ceiling (X._Object)
3459 -- Note that although X'Priority is notionally an object, it is quite
3460 -- deliberately not defined as an aliased object in the RM. This means
3461 -- that it works fine to rewrite it as a call, without having to worry
3462 -- about complications that would other arise from X'Priority'Access,
3463 -- which is illegal, because of the lack of aliasing.
3465 when Attribute_Priority =>
3468 Conctyp : Entity_Id;
3469 Object_Parm : Node_Id;
3471 RT_Subprg_Name : Node_Id;
3474 -- Look for the enclosing concurrent type
3476 Conctyp := Current_Scope;
3477 while not Is_Concurrent_Type (Conctyp) loop
3478 Conctyp := Scope (Conctyp);
3481 pragma Assert (Is_Protected_Type (Conctyp));
3483 -- Generate the actual of the call
3485 Subprg := Current_Scope;
3486 while not Present (Protected_Body_Subprogram (Subprg)) loop
3487 Subprg := Scope (Subprg);
3490 -- Use of 'Priority inside protected entries and barriers (in
3491 -- both cases the type of the first formal of their expanded
3492 -- subprogram is Address)
3494 if Etype (First_Entity (Protected_Body_Subprogram (Subprg)))
3498 New_Itype : Entity_Id;
3501 -- In the expansion of protected entries the type of the
3502 -- first formal of the Protected_Body_Subprogram is an
3503 -- Address. In order to reference the _object component
3506 -- type T is access p__ptTV;
3509 New_Itype := Create_Itype (E_Access_Type, N);
3510 Set_Etype (New_Itype, New_Itype);
3511 Set_Directly_Designated_Type (New_Itype,
3512 Corresponding_Record_Type (Conctyp));
3513 Freeze_Itype (New_Itype, N);
3516 -- T!(O)._object'unchecked_access
3519 Make_Attribute_Reference (Loc,
3521 Make_Selected_Component (Loc,
3523 Unchecked_Convert_To (New_Itype,
3526 (Protected_Body_Subprogram (Subprg)),
3529 Make_Identifier (Loc, Name_uObject)),
3530 Attribute_Name => Name_Unchecked_Access);
3533 -- Use of 'Priority inside a protected subprogram
3537 Make_Attribute_Reference (Loc,
3539 Make_Selected_Component (Loc,
3540 Prefix => New_Reference_To
3542 (Protected_Body_Subprogram (Subprg)),
3545 Make_Identifier (Loc, Name_uObject)),
3546 Attribute_Name => Name_Unchecked_Access);
3549 -- Select the appropriate run-time subprogram
3551 if Number_Entries (Conctyp) = 0 then
3553 New_Reference_To (RTE (RE_Get_Ceiling), Loc);
3556 New_Reference_To (RTE (RO_PE_Get_Ceiling), Loc);
3560 Make_Function_Call (Loc,
3561 Name => RT_Subprg_Name,
3562 Parameter_Associations => New_List (Object_Parm));
3566 -- Avoid the generation of extra checks on the pointer to the
3567 -- protected object.
3569 Analyze_And_Resolve (N, Typ, Suppress => Access_Check);
3576 when Attribute_Range_Length => Range_Length : begin
3578 -- The only special processing required is for the case where
3579 -- Range_Length is applied to an enumeration type with holes.
3580 -- In this case we transform
3586 -- X'Pos (X'Last) - X'Pos (X'First) + 1
3588 -- So that the result reflects the proper Pos values instead
3589 -- of the underlying representations.
3591 if Is_Enumeration_Type (Ptyp)
3592 and then Has_Non_Standard_Rep (Ptyp)
3597 Make_Op_Subtract (Loc,
3599 Make_Attribute_Reference (Loc,
3600 Attribute_Name => Name_Pos,
3601 Prefix => New_Occurrence_Of (Ptyp, Loc),
3602 Expressions => New_List (
3603 Make_Attribute_Reference (Loc,
3604 Attribute_Name => Name_Last,
3605 Prefix => New_Occurrence_Of (Ptyp, Loc)))),
3608 Make_Attribute_Reference (Loc,
3609 Attribute_Name => Name_Pos,
3610 Prefix => New_Occurrence_Of (Ptyp, Loc),
3611 Expressions => New_List (
3612 Make_Attribute_Reference (Loc,
3613 Attribute_Name => Name_First,
3614 Prefix => New_Occurrence_Of (Ptyp, Loc))))),
3616 Right_Opnd => Make_Integer_Literal (Loc, 1)));
3618 Analyze_And_Resolve (N, Typ);
3620 -- For all other cases, the attribute is handled by the back end, but
3621 -- we need to deal with the case of the range check on a universal
3625 Apply_Universal_Integer_Attribute_Checks (N);
3633 when Attribute_Read => Read : declare
3634 P_Type : constant Entity_Id := Entity (Pref);
3635 B_Type : constant Entity_Id := Base_Type (P_Type);
3636 U_Type : constant Entity_Id := Underlying_Type (P_Type);
3646 -- If no underlying type, we have an error that will be diagnosed
3647 -- elsewhere, so here we just completely ignore the expansion.
3653 -- The simple case, if there is a TSS for Read, just call it
3655 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
3657 if Present (Pname) then
3661 -- If there is a Stream_Convert pragma, use it, we rewrite
3663 -- sourcetyp'Read (stream, Item)
3667 -- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
3669 -- where strmread is the given Read function that converts an
3670 -- argument of type strmtyp to type sourcetyp or a type from which
3671 -- it is derived. The conversion to sourcetyp is required in the
3674 -- A special case arises if Item is a type conversion in which
3675 -- case, we have to expand to:
3677 -- Itemx := typex (strmread (strmtyp'Input (Stream)));
3679 -- where Itemx is the expression of the type conversion (i.e.
3680 -- the actual object), and typex is the type of Itemx.
3682 Prag := Get_Stream_Convert_Pragma (P_Type);
3684 if Present (Prag) then
3685 Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
3686 Rfunc := Entity (Expression (Arg2));
3687 Lhs := Relocate_Node (Next (First (Exprs)));
3689 OK_Convert_To (B_Type,
3690 Make_Function_Call (Loc,
3691 Name => New_Occurrence_Of (Rfunc, Loc),
3692 Parameter_Associations => New_List (
3693 Make_Attribute_Reference (Loc,
3696 (Etype (First_Formal (Rfunc)), Loc),
3697 Attribute_Name => Name_Input,
3698 Expressions => New_List (
3699 Relocate_Node (First (Exprs)))))));
3701 if Nkind (Lhs) = N_Type_Conversion then
3702 Lhs := Expression (Lhs);
3703 Rhs := Convert_To (Etype (Lhs), Rhs);
3707 Make_Assignment_Statement (Loc,
3709 Expression => Rhs));
3710 Set_Assignment_OK (Lhs);
3714 -- For elementary types, we call the I_xxx routine using the first
3715 -- parameter and then assign the result into the second parameter.
3716 -- We set Assignment_OK to deal with the conversion case.
3718 elsif Is_Elementary_Type (U_Type) then
3724 Lhs := Relocate_Node (Next (First (Exprs)));
3725 Rhs := Build_Elementary_Input_Call (N);
3727 if Nkind (Lhs) = N_Type_Conversion then
3728 Lhs := Expression (Lhs);
3729 Rhs := Convert_To (Etype (Lhs), Rhs);
3732 Set_Assignment_OK (Lhs);
3735 Make_Assignment_Statement (Loc,
3737 Expression => Rhs));
3745 elsif Is_Array_Type (U_Type) then
3746 Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
3747 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
3749 -- Tagged type case, use the primitive Read function. Note that
3750 -- this will dispatch in the class-wide case which is what we want
3752 elsif Is_Tagged_Type (U_Type) then
3753 Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
3755 -- All other record type cases, including protected records. The
3756 -- latter only arise for expander generated code for handling
3757 -- shared passive partition access.
3761 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
3763 -- Ada 2005 (AI-216): Program_Error is raised when executing
3764 -- the default implementation of the Read attribute of an
3765 -- Unchecked_Union type.
3767 if Is_Unchecked_Union (Base_Type (U_Type)) then
3769 Make_Raise_Program_Error (Loc,
3770 Reason => PE_Unchecked_Union_Restriction));
3773 if Has_Discriminants (U_Type)
3775 (Discriminant_Default_Value (First_Discriminant (U_Type)))
3777 Build_Mutable_Record_Read_Procedure
3778 (Loc, Full_Base (U_Type), Decl, Pname);
3780 Build_Record_Read_Procedure
3781 (Loc, Full_Base (U_Type), Decl, Pname);
3784 -- Suppress checks, uninitialized or otherwise invalid
3785 -- data does not cause constraint errors to be raised for
3786 -- a complete record read.
3788 Insert_Action (N, Decl, All_Checks);
3792 Rewrite_Stream_Proc_Call (Pname);
3799 -- Ref is identical to To_Address, see To_Address for processing
3805 -- Transforms 'Remainder into a call to the floating-point attribute
3806 -- function Remainder in Fat_xxx (where xxx is the root type)
3808 when Attribute_Remainder =>
3809 Expand_Fpt_Attribute_RR (N);
3815 -- Transform 'Result into reference to _Result formal. At the point
3816 -- where a legal 'Result attribute is expanded, we know that we are in
3817 -- the context of a _Postcondition function with a _Result parameter.
3819 when Attribute_Result =>
3820 Rewrite (N, Make_Identifier (Loc, Chars => Name_uResult));
3821 Analyze_And_Resolve (N, Typ);
3827 -- The handling of the Round attribute is quite delicate. The processing
3828 -- in Sem_Attr introduced a conversion to universal real, reflecting the
3829 -- semantics of Round, but we do not want anything to do with universal
3830 -- real at runtime, since this corresponds to using floating-point
3833 -- What we have now is that the Etype of the Round attribute correctly
3834 -- indicates the final result type. The operand of the Round is the
3835 -- conversion to universal real, described above, and the operand of
3836 -- this conversion is the actual operand of Round, which may be the
3837 -- special case of a fixed point multiplication or division (Etype =
3840 -- The exapander will expand first the operand of the conversion, then
3841 -- the conversion, and finally the round attribute itself, since we
3842 -- always work inside out. But we cannot simply process naively in this
3843 -- order. In the semantic world where universal fixed and real really
3844 -- exist and have infinite precision, there is no problem, but in the
3845 -- implementation world, where universal real is a floating-point type,
3846 -- we would get the wrong result.
3848 -- So the approach is as follows. First, when expanding a multiply or
3849 -- divide whose type is universal fixed, we do nothing at all, instead
3850 -- deferring the operation till later.
3852 -- The actual processing is done in Expand_N_Type_Conversion which
3853 -- handles the special case of Round by looking at its parent to see if
3854 -- it is a Round attribute, and if it is, handling the conversion (or
3855 -- its fixed multiply/divide child) in an appropriate manner.
3857 -- This means that by the time we get to expanding the Round attribute
3858 -- itself, the Round is nothing more than a type conversion (and will
3859 -- often be a null type conversion), so we just replace it with the
3860 -- appropriate conversion operation.
3862 when Attribute_Round =>
3864 Convert_To (Etype (N), Relocate_Node (First (Exprs))));
3865 Analyze_And_Resolve (N);
3871 -- Transforms 'Rounding into a call to the floating-point attribute
3872 -- function Rounding in Fat_xxx (where xxx is the root type)
3874 when Attribute_Rounding =>
3875 Expand_Fpt_Attribute_R (N);
3881 -- Transforms 'Scaling into a call to the floating-point attribute
3882 -- function Scaling in Fat_xxx (where xxx is the root type)
3884 when Attribute_Scaling =>
3885 Expand_Fpt_Attribute_RI (N);
3891 when Attribute_Size |
3892 Attribute_Object_Size |
3893 Attribute_Value_Size |
3894 Attribute_VADS_Size => Size :
3901 -- Processing for VADS_Size case. Note that this processing removes
3902 -- all traces of VADS_Size from the tree, and completes all required
3903 -- processing for VADS_Size by translating the attribute reference
3904 -- to an appropriate Size or Object_Size reference.
3906 if Id = Attribute_VADS_Size
3907 or else (Use_VADS_Size and then Id = Attribute_Size)
3909 -- If the size is specified, then we simply use the specified
3910 -- size. This applies to both types and objects. The size of an
3911 -- object can be specified in the following ways:
3913 -- An explicit size object is given for an object
3914 -- A component size is specified for an indexed component
3915 -- A component clause is specified for a selected component
3916 -- The object is a component of a packed composite object
3918 -- If the size is specified, then VADS_Size of an object
3920 if (Is_Entity_Name (Pref)
3921 and then Present (Size_Clause (Entity (Pref))))
3923 (Nkind (Pref) = N_Component_Clause
3924 and then (Present (Component_Clause
3925 (Entity (Selector_Name (Pref))))
3926 or else Is_Packed (Etype (Prefix (Pref)))))
3928 (Nkind (Pref) = N_Indexed_Component
3929 and then (Component_Size (Etype (Prefix (Pref))) /= 0
3930 or else Is_Packed (Etype (Prefix (Pref)))))
3932 Set_Attribute_Name (N, Name_Size);
3934 -- Otherwise if we have an object rather than a type, then the
3935 -- VADS_Size attribute applies to the type of the object, rather
3936 -- than the object itself. This is one of the respects in which
3937 -- VADS_Size differs from Size.
3940 if (not Is_Entity_Name (Pref)
3941 or else not Is_Type (Entity (Pref)))
3942 and then (Is_Scalar_Type (Ptyp) or else Is_Constrained (Ptyp))
3944 Rewrite (Pref, New_Occurrence_Of (Ptyp, Loc));
3947 -- For a scalar type for which no size was explicitly given,
3948 -- VADS_Size means Object_Size. This is the other respect in
3949 -- which VADS_Size differs from Size.
3951 if Is_Scalar_Type (Ptyp) and then No (Size_Clause (Ptyp)) then
3952 Set_Attribute_Name (N, Name_Object_Size);
3954 -- In all other cases, Size and VADS_Size are the sane
3957 Set_Attribute_Name (N, Name_Size);
3962 -- For class-wide types, X'Class'Size is transformed into a direct
3963 -- reference to the Size of the class type, so that the back end does
3964 -- not have to deal with the X'Class'Size reference.
3966 if Is_Entity_Name (Pref)
3967 and then Is_Class_Wide_Type (Entity (Pref))
3969 Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc));
3972 -- For X'Size applied to an object of a class-wide type, transform
3973 -- X'Size into a call to the primitive operation _Size applied to X.
3975 elsif Is_Class_Wide_Type (Ptyp)
3976 or else (Id = Attribute_Size
3977 and then Is_Tagged_Type (Ptyp)
3978 and then Has_Unknown_Discriminants (Ptyp))
3980 -- No need to do anything else compiling under restriction
3981 -- No_Dispatching_Calls. During the semantic analysis we
3982 -- already notified such violation.
3984 if Restriction_Active (No_Dispatching_Calls) then
3989 Make_Function_Call (Loc,
3990 Name => New_Reference_To
3991 (Find_Prim_Op (Ptyp, Name_uSize), Loc),
3992 Parameter_Associations => New_List (Pref));
3994 if Typ /= Standard_Long_Long_Integer then
3996 -- The context is a specific integer type with which the
3997 -- original attribute was compatible. The function has a
3998 -- specific type as well, so to preserve the compatibility
3999 -- we must convert explicitly.
4001 New_Node := Convert_To (Typ, New_Node);
4004 Rewrite (N, New_Node);
4005 Analyze_And_Resolve (N, Typ);
4008 -- Case of known RM_Size of a type
4010 elsif (Id = Attribute_Size or else Id = Attribute_Value_Size)
4011 and then Is_Entity_Name (Pref)
4012 and then Is_Type (Entity (Pref))
4013 and then Known_Static_RM_Size (Entity (Pref))
4015 Siz := RM_Size (Entity (Pref));
4017 -- Case of known Esize of a type
4019 elsif Id = Attribute_Object_Size
4020 and then Is_Entity_Name (Pref)
4021 and then Is_Type (Entity (Pref))
4022 and then Known_Static_Esize (Entity (Pref))
4024 Siz := Esize (Entity (Pref));
4026 -- Case of known size of object
4028 elsif Id = Attribute_Size
4029 and then Is_Entity_Name (Pref)
4030 and then Is_Object (Entity (Pref))
4031 and then Known_Esize (Entity (Pref))
4032 and then Known_Static_Esize (Entity (Pref))
4034 Siz := Esize (Entity (Pref));
4036 -- For an array component, we can do Size in the front end
4037 -- if the component_size of the array is set.
4039 elsif Nkind (Pref) = N_Indexed_Component then
4040 Siz := Component_Size (Etype (Prefix (Pref)));
4042 -- For a record component, we can do Size in the front end if there
4043 -- is a component clause, or if the record is packed and the
4044 -- component's size is known at compile time.
4046 elsif Nkind (Pref) = N_Selected_Component then
4048 Rec : constant Entity_Id := Etype (Prefix (Pref));
4049 Comp : constant Entity_Id := Entity (Selector_Name (Pref));
4052 if Present (Component_Clause (Comp)) then
4053 Siz := Esize (Comp);
4055 elsif Is_Packed (Rec) then
4056 Siz := RM_Size (Ptyp);
4059 Apply_Universal_Integer_Attribute_Checks (N);
4064 -- All other cases are handled by the back end
4067 Apply_Universal_Integer_Attribute_Checks (N);
4069 -- If Size is applied to a formal parameter that is of a packed
4070 -- array subtype, then apply Size to the actual subtype.
4072 if Is_Entity_Name (Pref)
4073 and then Is_Formal (Entity (Pref))
4074 and then Is_Array_Type (Ptyp)
4075 and then Is_Packed (Ptyp)
4078 Make_Attribute_Reference (Loc,
4080 New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
4081 Attribute_Name => Name_Size));
4082 Analyze_And_Resolve (N, Typ);
4085 -- If Size applies to a dereference of an access to unconstrained
4086 -- packed array, the back end needs to see its unconstrained
4087 -- nominal type, but also a hint to the actual constrained type.
4089 if Nkind (Pref) = N_Explicit_Dereference
4090 and then Is_Array_Type (Ptyp)
4091 and then not Is_Constrained (Ptyp)
4092 and then Is_Packed (Ptyp)
4094 Set_Actual_Designated_Subtype (Pref,
4095 Get_Actual_Subtype (Pref));
4101 -- Common processing for record and array component case
4103 if Siz /= No_Uint and then Siz /= 0 then
4105 CS : constant Boolean := Comes_From_Source (N);
4108 Rewrite (N, Make_Integer_Literal (Loc, Siz));
4110 -- This integer literal is not a static expression. We do not
4111 -- call Analyze_And_Resolve here, because this would activate
4112 -- the circuit for deciding that a static value was out of
4113 -- range, and we don't want that.
4115 -- So just manually set the type, mark the expression as non-
4116 -- static, and then ensure that the result is checked properly
4117 -- if the attribute comes from source (if it was internally
4118 -- generated, we never need a constraint check).
4121 Set_Is_Static_Expression (N, False);
4124 Apply_Constraint_Check (N, Typ);
4134 when Attribute_Storage_Pool =>
4136 Make_Type_Conversion (Loc,
4137 Subtype_Mark => New_Reference_To (Etype (N), Loc),
4138 Expression => New_Reference_To (Entity (N), Loc)));
4139 Analyze_And_Resolve (N, Typ);
4145 when Attribute_Storage_Size => Storage_Size : begin
4147 -- Access type case, always go to the root type
4149 -- The case of access types results in a value of zero for the case
4150 -- where no storage size attribute clause has been given. If a
4151 -- storage size has been given, then the attribute is converted
4152 -- to a reference to the variable used to hold this value.
4154 if Is_Access_Type (Ptyp) then
4155 if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
4157 Make_Attribute_Reference (Loc,
4158 Prefix => New_Reference_To (Typ, Loc),
4159 Attribute_Name => Name_Max,
4160 Expressions => New_List (
4161 Make_Integer_Literal (Loc, 0),
4164 (Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
4166 elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
4169 Make_Function_Call (Loc,
4173 (Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
4174 Attribute_Name (N)),
4177 Parameter_Associations => New_List (
4179 (Associated_Storage_Pool (Root_Type (Ptyp)), Loc)))));
4182 Rewrite (N, Make_Integer_Literal (Loc, 0));
4185 Analyze_And_Resolve (N, Typ);
4187 -- For tasks, we retrieve the size directly from the TCB. The
4188 -- size may depend on a discriminant of the type, and therefore
4189 -- can be a per-object expression, so type-level information is
4190 -- not sufficient in general. There are four cases to consider:
4192 -- a) If the attribute appears within a task body, the designated
4193 -- TCB is obtained by a call to Self.
4195 -- b) If the prefix of the attribute is the name of a task object,
4196 -- the designated TCB is the one stored in the corresponding record.
4198 -- c) If the prefix is a task type, the size is obtained from the
4199 -- size variable created for each task type
4201 -- d) If no storage_size was specified for the type , there is no
4202 -- size variable, and the value is a system-specific default.
4205 if In_Open_Scopes (Ptyp) then
4207 -- Storage_Size (Self)
4211 Make_Function_Call (Loc,
4213 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4214 Parameter_Associations =>
4216 Make_Function_Call (Loc,
4218 New_Reference_To (RTE (RE_Self), Loc))))));
4220 elsif not Is_Entity_Name (Pref)
4221 or else not Is_Type (Entity (Pref))
4223 -- Storage_Size (Rec (Obj).Size)
4227 Make_Function_Call (Loc,
4229 New_Occurrence_Of (RTE (RE_Storage_Size), Loc),
4230 Parameter_Associations =>
4232 Make_Selected_Component (Loc,
4234 Unchecked_Convert_To (
4235 Corresponding_Record_Type (Ptyp),
4236 New_Copy_Tree (Pref)),
4238 Make_Identifier (Loc, Name_uTask_Id))))));
4240 elsif Present (Storage_Size_Variable (Ptyp)) then
4242 -- Static storage size pragma given for type: retrieve value
4243 -- from its allocated storage variable.
4247 Make_Function_Call (Loc,
4248 Name => New_Occurrence_Of (
4249 RTE (RE_Adjust_Storage_Size), Loc),
4250 Parameter_Associations =>
4253 Storage_Size_Variable (Ptyp), Loc)))));
4255 -- Get system default
4259 Make_Function_Call (Loc,
4262 RTE (RE_Default_Stack_Size), Loc))));
4265 Analyze_And_Resolve (N, Typ);
4273 when Attribute_Stream_Size => Stream_Size : declare
4277 -- If we have a Stream_Size clause for this type use it, otherwise
4278 -- the Stream_Size if the size of the type.
4280 if Has_Stream_Size_Clause (Ptyp) then
4283 (Static_Integer (Expression (Stream_Size_Clause (Ptyp))));
4285 Size := UI_To_Int (Esize (Ptyp));
4288 Rewrite (N, Make_Integer_Literal (Loc, Intval => Size));
4289 Analyze_And_Resolve (N, Typ);
4296 -- 1. Deal with enumeration types with holes
4297 -- 2. For floating-point, generate call to attribute function
4298 -- 3. For other cases, deal with constraint checking
4300 when Attribute_Succ => Succ : declare
4301 Etyp : constant Entity_Id := Base_Type (Ptyp);
4305 -- For enumeration types with non-standard representations, we
4306 -- expand typ'Succ (x) into
4308 -- Pos_To_Rep (Rep_To_Pos (x) + 1)
4310 -- If the representation is contiguous, we compute instead
4311 -- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
4313 if Is_Enumeration_Type (Ptyp)
4314 and then Present (Enum_Pos_To_Rep (Etyp))
4316 if Has_Contiguous_Rep (Etyp) then
4318 Unchecked_Convert_To (Ptyp,
4321 Make_Integer_Literal (Loc,
4322 Enumeration_Rep (First_Literal (Ptyp))),
4324 Make_Function_Call (Loc,
4327 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4329 Parameter_Associations =>
4331 Unchecked_Convert_To (Ptyp,
4334 Unchecked_Convert_To (Standard_Integer,
4335 Relocate_Node (First (Exprs))),
4337 Make_Integer_Literal (Loc, 1))),
4338 Rep_To_Pos_Flag (Ptyp, Loc))))));
4340 -- Add Boolean parameter True, to request program errror if
4341 -- we have a bad representation on our hands. Add False if
4342 -- checks are suppressed.
4344 Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
4346 Make_Indexed_Component (Loc,
4349 (Enum_Pos_To_Rep (Etyp), Loc),
4350 Expressions => New_List (
4353 Make_Function_Call (Loc,
4356 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4357 Parameter_Associations => Exprs),
4358 Right_Opnd => Make_Integer_Literal (Loc, 1)))));
4361 Analyze_And_Resolve (N, Typ);
4363 -- For floating-point, we transform 'Succ into a call to the Succ
4364 -- floating-point attribute function in Fat_xxx (xxx is root type)
4366 elsif Is_Floating_Point_Type (Ptyp) then
4367 Expand_Fpt_Attribute_R (N);
4368 Analyze_And_Resolve (N, Typ);
4370 -- For modular types, nothing to do (no overflow, since wraps)
4372 elsif Is_Modular_Integer_Type (Ptyp) then
4375 -- For other types, if argument is marked as needing a range check or
4376 -- overflow checking is enabled, we must generate a check.
4378 elsif not Overflow_Checks_Suppressed (Ptyp)
4379 or else Do_Range_Check (First (Exprs))
4381 Set_Do_Range_Check (First (Exprs), False);
4382 Expand_Pred_Succ (N);
4390 -- Transforms X'Tag into a direct reference to the tag of X
4392 when Attribute_Tag => Tag : declare
4394 Prefix_Is_Type : Boolean;
4397 if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
4398 Ttyp := Entity (Pref);
4399 Prefix_Is_Type := True;
4402 Prefix_Is_Type := False;
4405 if Is_Class_Wide_Type (Ttyp) then
4406 Ttyp := Root_Type (Ttyp);
4409 Ttyp := Underlying_Type (Ttyp);
4411 -- Ada 2005: The type may be a synchronized tagged type, in which
4412 -- case the tag information is stored in the corresponding record.
4414 if Is_Concurrent_Type (Ttyp) then
4415 Ttyp := Corresponding_Record_Type (Ttyp);
4418 if Prefix_Is_Type then
4420 -- For VMs we leave the type attribute unexpanded because
4421 -- there's not a dispatching table to reference.
4423 if Tagged_Type_Expansion then
4425 Unchecked_Convert_To (RTE (RE_Tag),
4427 (Node (First_Elmt (Access_Disp_Table (Ttyp))), Loc)));
4428 Analyze_And_Resolve (N, RTE (RE_Tag));
4431 -- Ada 2005 (AI-251): The use of 'Tag in the sources always
4432 -- references the primary tag of the actual object. If 'Tag is
4433 -- applied to class-wide interface objects we generate code that
4434 -- displaces "this" to reference the base of the object.
4436 elsif Comes_From_Source (N)
4437 and then Is_Class_Wide_Type (Etype (Prefix (N)))
4438 and then Is_Interface (Etype (Prefix (N)))
4441 -- (To_Tag_Ptr (Prefix'Address)).all
4443 -- Note that Prefix'Address is recursively expanded into a call
4444 -- to Base_Address (Obj.Tag)
4446 -- Not needed for VM targets, since all handled by the VM
4448 if Tagged_Type_Expansion then
4450 Make_Explicit_Dereference (Loc,
4451 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
4452 Make_Attribute_Reference (Loc,
4453 Prefix => Relocate_Node (Pref),
4454 Attribute_Name => Name_Address))));
4455 Analyze_And_Resolve (N, RTE (RE_Tag));
4460 Make_Selected_Component (Loc,
4461 Prefix => Relocate_Node (Pref),
4463 New_Reference_To (First_Tag_Component (Ttyp), Loc)));
4464 Analyze_And_Resolve (N, RTE (RE_Tag));
4472 -- Transforms 'Terminated attribute into a call to Terminated function
4474 when Attribute_Terminated => Terminated :
4476 -- The prefix of Terminated is of a task interface class-wide type.
4478 -- terminated (Task_Id (Pref._disp_get_task_id));
4480 if Ada_Version >= Ada_2005
4481 and then Ekind (Ptyp) = E_Class_Wide_Type
4482 and then Is_Interface (Ptyp)
4483 and then Is_Task_Interface (Ptyp)
4486 Make_Function_Call (Loc,
4488 New_Reference_To (RTE (RE_Terminated), Loc),
4489 Parameter_Associations => New_List (
4490 Make_Unchecked_Type_Conversion (Loc,
4492 New_Reference_To (RTE (RO_ST_Task_Id), Loc),
4494 Make_Selected_Component (Loc,
4496 New_Copy_Tree (Pref),
4498 Make_Identifier (Loc, Name_uDisp_Get_Task_Id))))));
4500 elsif Restricted_Profile then
4502 Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
4506 Build_Call_With_Task (Pref, RTE (RE_Terminated)));
4509 Analyze_And_Resolve (N, Standard_Boolean);
4516 -- Transforms System'To_Address (X) and System.Address'Ref (X) into
4517 -- unchecked conversion from (integral) type of X to type address.
4519 when Attribute_To_Address | Attribute_Ref =>
4521 Unchecked_Convert_To (RTE (RE_Address),
4522 Relocate_Node (First (Exprs))));
4523 Analyze_And_Resolve (N, RTE (RE_Address));
4529 when Attribute_To_Any => To_Any : declare
4530 P_Type : constant Entity_Id := Etype (Pref);
4531 Decls : constant List_Id := New_List;
4535 (Convert_To (P_Type,
4536 Relocate_Node (First (Exprs))), Decls));
4537 Insert_Actions (N, Decls);
4538 Analyze_And_Resolve (N, RTE (RE_Any));
4545 -- Transforms 'Truncation into a call to the floating-point attribute
4546 -- function Truncation in Fat_xxx (where xxx is the root type).
4547 -- Expansion is avoided for cases the back end can handle directly.
4549 when Attribute_Truncation =>
4550 if not Is_Inline_Floating_Point_Attribute (N) then
4551 Expand_Fpt_Attribute_R (N);
4558 when Attribute_TypeCode => TypeCode : declare
4559 P_Type : constant Entity_Id := Etype (Pref);
4560 Decls : constant List_Id := New_List;
4562 Rewrite (N, Build_TypeCode_Call (Loc, P_Type, Decls));
4563 Insert_Actions (N, Decls);
4564 Analyze_And_Resolve (N, RTE (RE_TypeCode));
4567 -----------------------
4568 -- Unbiased_Rounding --
4569 -----------------------
4571 -- Transforms 'Unbiased_Rounding into a call to the floating-point
4572 -- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
4573 -- root type). Expansion is avoided for cases the back end can handle
4576 when Attribute_Unbiased_Rounding =>
4577 if not Is_Inline_Floating_Point_Attribute (N) then
4578 Expand_Fpt_Attribute_R (N);
4585 when Attribute_UET_Address => UET_Address : declare
4586 Ent : constant Entity_Id := Make_Temporary (Loc, 'T');
4590 Make_Object_Declaration (Loc,
4591 Defining_Identifier => Ent,
4592 Aliased_Present => True,
4593 Object_Definition =>
4594 New_Occurrence_Of (RTE (RE_Address), Loc)));
4596 -- Construct name __gnat_xxx__SDP, where xxx is the unit name
4597 -- in normal external form.
4599 Get_External_Unit_Name_String (Get_Unit_Name (Pref));
4600 Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
4601 Name_Len := Name_Len + 7;
4602 Name_Buffer (1 .. 7) := "__gnat_";
4603 Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
4604 Name_Len := Name_Len + 5;
4606 Set_Is_Imported (Ent);
4607 Set_Interface_Name (Ent,
4608 Make_String_Literal (Loc,
4609 Strval => String_From_Name_Buffer));
4611 -- Set entity as internal to ensure proper Sprint output of its
4612 -- implicit importation.
4614 Set_Is_Internal (Ent);
4617 Make_Attribute_Reference (Loc,
4618 Prefix => New_Occurrence_Of (Ent, Loc),
4619 Attribute_Name => Name_Address));
4621 Analyze_And_Resolve (N, Typ);
4628 -- The processing for VADS_Size is shared with Size
4634 -- For enumeration types with a standard representation, and for all
4635 -- other types, Val is handled by the back end. For enumeration types
4636 -- with a non-standard representation we use the _Pos_To_Rep array that
4637 -- was created when the type was frozen.
4639 when Attribute_Val => Val : declare
4640 Etyp : constant Entity_Id := Base_Type (Entity (Pref));
4643 if Is_Enumeration_Type (Etyp)
4644 and then Present (Enum_Pos_To_Rep (Etyp))
4646 if Has_Contiguous_Rep (Etyp) then
4648 Rep_Node : constant Node_Id :=
4649 Unchecked_Convert_To (Etyp,
4652 Make_Integer_Literal (Loc,
4653 Enumeration_Rep (First_Literal (Etyp))),
4655 (Convert_To (Standard_Integer,
4656 Relocate_Node (First (Exprs))))));
4660 Unchecked_Convert_To (Etyp,
4663 Make_Integer_Literal (Loc,
4664 Enumeration_Rep (First_Literal (Etyp))),
4666 Make_Function_Call (Loc,
4669 (TSS (Etyp, TSS_Rep_To_Pos), Loc),
4670 Parameter_Associations => New_List (
4672 Rep_To_Pos_Flag (Etyp, Loc))))));
4677 Make_Indexed_Component (Loc,
4678 Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
4679 Expressions => New_List (
4680 Convert_To (Standard_Integer,
4681 Relocate_Node (First (Exprs))))));
4684 Analyze_And_Resolve (N, Typ);
4686 -- If the argument is marked as requiring a range check then generate
4689 elsif Do_Range_Check (First (Exprs)) then
4690 Set_Do_Range_Check (First (Exprs), False);
4691 Generate_Range_Check (First (Exprs), Etyp, CE_Range_Check_Failed);
4699 -- The code for valid is dependent on the particular types involved.
4700 -- See separate sections below for the generated code in each case.
4702 when Attribute_Valid => Valid : declare
4703 Btyp : Entity_Id := Base_Type (Ptyp);
4706 Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
4707 -- Save the validity checking mode. We always turn off validity
4708 -- checking during process of 'Valid since this is one place
4709 -- where we do not want the implicit validity checks to intefere
4710 -- with the explicit validity check that the programmer is doing.
4712 function Make_Range_Test return Node_Id;
4713 -- Build the code for a range test of the form
4714 -- Btyp!(Pref) in Btyp!(Ptyp'First) .. Btyp!(Ptyp'Last)
4716 ---------------------
4717 -- Make_Range_Test --
4718 ---------------------
4720 function Make_Range_Test return Node_Id is
4721 Temp : constant Node_Id := Duplicate_Subexpr (Pref);
4724 -- The value whose validity is being checked has been captured in
4725 -- an object declaration. We certainly don't want this object to
4726 -- appear valid because the declaration initializes it!
4728 if Is_Entity_Name (Temp) then
4729 Set_Is_Known_Valid (Entity (Temp), False);
4735 Unchecked_Convert_To (Btyp, Temp),
4739 Unchecked_Convert_To (Btyp,
4740 Make_Attribute_Reference (Loc,
4741 Prefix => New_Occurrence_Of (Ptyp, Loc),
4742 Attribute_Name => Name_First)),
4744 Unchecked_Convert_To (Btyp,
4745 Make_Attribute_Reference (Loc,
4746 Prefix => New_Occurrence_Of (Ptyp, Loc),
4747 Attribute_Name => Name_Last))));
4748 end Make_Range_Test;
4750 -- Start of processing for Attribute_Valid
4753 -- Do not expand sourced code 'Valid reference in CodePeer mode,
4754 -- will be handled by the back-end directly.
4756 if CodePeer_Mode and then Comes_From_Source (N) then
4760 -- Turn off validity checks. We do not want any implicit validity
4761 -- checks to intefere with the explicit check from the attribute
4763 Validity_Checks_On := False;
4765 -- Floating-point case. This case is handled by the Valid attribute
4766 -- code in the floating-point attribute run-time library.
4768 if Is_Floating_Point_Type (Ptyp) then
4775 case Float_Rep (Btyp) is
4776 -- For vax fpt types, call appropriate routine in special
4777 -- vax floating point unit. We do not have to worry about
4778 -- loads in this case, since these types have no signalling
4781 when VAX_Native => Expand_Vax_Valid (N);
4783 -- The AAMP back end handles Valid for floating-point types
4786 Analyze_And_Resolve (Pref, Ptyp);
4787 Set_Etype (N, Standard_Boolean);
4791 Find_Fat_Info (Ptyp, Ftp, Pkg);
4793 -- If the floating-point object might be unaligned, we
4794 -- need to call the special routine Unaligned_Valid,
4795 -- which makes the needed copy, being careful not to
4796 -- load the value into any floating-point register.
4797 -- The argument in this case is obj'Address (see
4798 -- Unaligned_Valid routine in Fat_Gen).
4800 if Is_Possibly_Unaligned_Object (Pref) then
4801 Expand_Fpt_Attribute
4802 (N, Pkg, Name_Unaligned_Valid,
4804 Make_Attribute_Reference (Loc,
4805 Prefix => Relocate_Node (Pref),
4806 Attribute_Name => Name_Address)));
4808 -- In the normal case where we are sure the object is
4809 -- aligned, we generate a call to Valid, and the argument
4810 -- in this case is obj'Unrestricted_Access (after
4811 -- converting obj to the right floating-point type).
4814 Expand_Fpt_Attribute
4815 (N, Pkg, Name_Valid,
4817 Make_Attribute_Reference (Loc,
4818 Prefix => Unchecked_Convert_To (Ftp, Pref),
4819 Attribute_Name => Name_Unrestricted_Access)));
4823 -- One more task, we still need a range check. Required
4824 -- only if we have a constraint, since the Valid routine
4825 -- catches infinities properly (infinities are never valid).
4827 -- The way we do the range check is simply to create the
4828 -- expression: Valid (N) and then Base_Type(Pref) in Typ.
4830 if not Subtypes_Statically_Match (Ptyp, Btyp) then
4833 Left_Opnd => Relocate_Node (N),
4836 Left_Opnd => Convert_To (Btyp, Pref),
4837 Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
4841 -- Enumeration type with holes
4843 -- For enumeration types with holes, the Pos value constructed by
4844 -- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
4845 -- second argument of False returns minus one for an invalid value,
4846 -- and the non-negative pos value for a valid value, so the
4847 -- expansion of X'Valid is simply:
4849 -- type(X)'Pos (X) >= 0
4851 -- We can't quite generate it that way because of the requirement
4852 -- for the non-standard second argument of False in the resulting
4853 -- rep_to_pos call, so we have to explicitly create:
4855 -- _rep_to_pos (X, False) >= 0
4857 -- If we have an enumeration subtype, we also check that the
4858 -- value is in range:
4860 -- _rep_to_pos (X, False) >= 0
4862 -- (X >= type(X)'First and then type(X)'Last <= X)
4864 elsif Is_Enumeration_Type (Ptyp)
4865 and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp)))
4870 Make_Function_Call (Loc,
4873 (TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc),
4874 Parameter_Associations => New_List (
4876 New_Occurrence_Of (Standard_False, Loc))),
4877 Right_Opnd => Make_Integer_Literal (Loc, 0));
4881 (Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
4883 Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
4885 -- The call to Make_Range_Test will create declarations
4886 -- that need a proper insertion point, but Pref is now
4887 -- attached to a node with no ancestor. Attach to tree
4888 -- even if it is to be rewritten below.
4890 Set_Parent (Tst, Parent (N));
4894 Left_Opnd => Make_Range_Test,
4900 -- Fortran convention booleans
4902 -- For the very special case of Fortran convention booleans, the
4903 -- value is always valid, since it is an integer with the semantics
4904 -- that non-zero is true, and any value is permissible.
4906 elsif Is_Boolean_Type (Ptyp)
4907 and then Convention (Ptyp) = Convention_Fortran
4909 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
4911 -- For biased representations, we will be doing an unchecked
4912 -- conversion without unbiasing the result. That means that the range
4913 -- test has to take this into account, and the proper form of the
4916 -- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
4918 elsif Has_Biased_Representation (Ptyp) then
4919 Btyp := RTE (RE_Unsigned_32);
4923 Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
4925 Unchecked_Convert_To (Btyp,
4926 Make_Attribute_Reference (Loc,
4927 Prefix => New_Occurrence_Of (Ptyp, Loc),
4928 Attribute_Name => Name_Range_Length))));
4930 -- For all other scalar types, what we want logically is a
4933 -- X in type(X)'First .. type(X)'Last
4935 -- But that's precisely what won't work because of possible
4936 -- unwanted optimization (and indeed the basic motivation for
4937 -- the Valid attribute is exactly that this test does not work!)
4938 -- What will work is:
4940 -- Btyp!(X) >= Btyp!(type(X)'First)
4942 -- Btyp!(X) <= Btyp!(type(X)'Last)
4944 -- where Btyp is an integer type large enough to cover the full
4945 -- range of possible stored values (i.e. it is chosen on the basis
4946 -- of the size of the type, not the range of the values). We write
4947 -- this as two tests, rather than a range check, so that static
4948 -- evaluation will easily remove either or both of the checks if
4949 -- they can be -statically determined to be true (this happens
4950 -- when the type of X is static and the range extends to the full
4951 -- range of stored values).
4953 -- Unsigned types. Note: it is safe to consider only whether the
4954 -- subtype is unsigned, since we will in that case be doing all
4955 -- unsigned comparisons based on the subtype range. Since we use the
4956 -- actual subtype object size, this is appropriate.
4958 -- For example, if we have
4960 -- subtype x is integer range 1 .. 200;
4961 -- for x'Object_Size use 8;
4963 -- Now the base type is signed, but objects of this type are bits
4964 -- unsigned, and doing an unsigned test of the range 1 to 200 is
4965 -- correct, even though a value greater than 127 looks signed to a
4966 -- signed comparison.
4968 elsif Is_Unsigned_Type (Ptyp) then
4969 if Esize (Ptyp) <= 32 then
4970 Btyp := RTE (RE_Unsigned_32);
4972 Btyp := RTE (RE_Unsigned_64);
4975 Rewrite (N, Make_Range_Test);
4980 if Esize (Ptyp) <= Esize (Standard_Integer) then
4981 Btyp := Standard_Integer;
4983 Btyp := Universal_Integer;
4986 Rewrite (N, Make_Range_Test);
4989 Analyze_And_Resolve (N, Standard_Boolean);
4990 Validity_Checks_On := Save_Validity_Checks_On;
4997 -- Value attribute is handled in separate unti Exp_Imgv
4999 when Attribute_Value =>
5000 Exp_Imgv.Expand_Value_Attribute (N);
5006 -- The processing for Value_Size shares the processing for Size
5012 -- The processing for Version shares the processing for Body_Version
5018 -- Wide_Image attribute is handled in separate unit Exp_Imgv
5020 when Attribute_Wide_Image =>
5021 Exp_Imgv.Expand_Wide_Image_Attribute (N);
5023 ---------------------
5024 -- Wide_Wide_Image --
5025 ---------------------
5027 -- Wide_Wide_Image attribute is handled in separate unit Exp_Imgv
5029 when Attribute_Wide_Wide_Image =>
5030 Exp_Imgv.Expand_Wide_Wide_Image_Attribute (N);
5036 -- We expand typ'Wide_Value (X) into
5039 -- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
5041 -- Wide_String_To_String is a runtime function that converts its wide
5042 -- string argument to String, converting any non-translatable characters
5043 -- into appropriate escape sequences. This preserves the required
5044 -- semantics of Wide_Value in all cases, and results in a very simple
5045 -- implementation approach.
5047 -- Note: for this approach to be fully standard compliant for the cases
5048 -- where typ is Wide_Character and Wide_Wide_Character, the encoding
5049 -- method must cover the entire character range (e.g. UTF-8). But that
5050 -- is a reasonable requirement when dealing with encoded character
5051 -- sequences. Presumably if one of the restrictive encoding mechanisms
5052 -- is in use such as Shift-JIS, then characters that cannot be
5053 -- represented using this encoding will not appear in any case.
5055 when Attribute_Wide_Value => Wide_Value :
5058 Make_Attribute_Reference (Loc,
5060 Attribute_Name => Name_Value,
5062 Expressions => New_List (
5063 Make_Function_Call (Loc,
5065 New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
5067 Parameter_Associations => New_List (
5068 Relocate_Node (First (Exprs)),
5069 Make_Integer_Literal (Loc,
5070 Intval => Int (Wide_Character_Encoding_Method)))))));
5072 Analyze_And_Resolve (N, Typ);
5075 ---------------------
5076 -- Wide_Wide_Value --
5077 ---------------------
5079 -- We expand typ'Wide_Value_Value (X) into
5082 -- (Wide_Wide_String_To_String (X, Wide_Character_Encoding_Method))
5084 -- Wide_Wide_String_To_String is a runtime function that converts its
5085 -- wide string argument to String, converting any non-translatable
5086 -- characters into appropriate escape sequences. This preserves the
5087 -- required semantics of Wide_Wide_Value in all cases, and results in a
5088 -- very simple implementation approach.
5090 -- It's not quite right where typ = Wide_Wide_Character, because the
5091 -- encoding method may not cover the whole character type ???
5093 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
5096 Make_Attribute_Reference (Loc,
5098 Attribute_Name => Name_Value,
5100 Expressions => New_List (
5101 Make_Function_Call (Loc,
5103 New_Reference_To (RTE (RE_Wide_Wide_String_To_String), Loc),
5105 Parameter_Associations => New_List (
5106 Relocate_Node (First (Exprs)),
5107 Make_Integer_Literal (Loc,
5108 Intval => Int (Wide_Character_Encoding_Method)))))));
5110 Analyze_And_Resolve (N, Typ);
5111 end Wide_Wide_Value;
5113 ---------------------
5114 -- Wide_Wide_Width --
5115 ---------------------
5117 -- Wide_Wide_Width attribute is handled in separate unit Exp_Imgv
5119 when Attribute_Wide_Wide_Width =>
5120 Exp_Imgv.Expand_Width_Attribute (N, Wide_Wide);
5126 -- Wide_Width attribute is handled in separate unit Exp_Imgv
5128 when Attribute_Wide_Width =>
5129 Exp_Imgv.Expand_Width_Attribute (N, Wide);
5135 -- Width attribute is handled in separate unit Exp_Imgv
5137 when Attribute_Width =>
5138 Exp_Imgv.Expand_Width_Attribute (N, Normal);
5144 when Attribute_Write => Write : declare
5145 P_Type : constant Entity_Id := Entity (Pref);
5146 U_Type : constant Entity_Id := Underlying_Type (P_Type);
5154 -- If no underlying type, we have an error that will be diagnosed
5155 -- elsewhere, so here we just completely ignore the expansion.
5161 -- The simple case, if there is a TSS for Write, just call it
5163 Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
5165 if Present (Pname) then
5169 -- If there is a Stream_Convert pragma, use it, we rewrite
5171 -- sourcetyp'Output (stream, Item)
5175 -- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
5177 -- where strmwrite is the given Write function that converts an
5178 -- argument of type sourcetyp or a type acctyp, from which it is
5179 -- derived to type strmtyp. The conversion to acttyp is required
5180 -- for the derived case.
5182 Prag := Get_Stream_Convert_Pragma (P_Type);
5184 if Present (Prag) then
5186 Next (Next (First (Pragma_Argument_Associations (Prag))));
5187 Wfunc := Entity (Expression (Arg3));
5190 Make_Attribute_Reference (Loc,
5191 Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
5192 Attribute_Name => Name_Output,
5193 Expressions => New_List (
5194 Relocate_Node (First (Exprs)),
5195 Make_Function_Call (Loc,
5196 Name => New_Occurrence_Of (Wfunc, Loc),
5197 Parameter_Associations => New_List (
5198 OK_Convert_To (Etype (First_Formal (Wfunc)),
5199 Relocate_Node (Next (First (Exprs)))))))));
5204 -- For elementary types, we call the W_xxx routine directly
5206 elsif Is_Elementary_Type (U_Type) then
5207 Rewrite (N, Build_Elementary_Write_Call (N));
5213 elsif Is_Array_Type (U_Type) then
5214 Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
5215 Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
5217 -- Tagged type case, use the primitive Write function. Note that
5218 -- this will dispatch in the class-wide case which is what we want
5220 elsif Is_Tagged_Type (U_Type) then
5221 Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
5223 -- All other record type cases, including protected records.
5224 -- The latter only arise for expander generated code for
5225 -- handling shared passive partition access.
5229 (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
5231 -- Ada 2005 (AI-216): Program_Error is raised when executing
5232 -- the default implementation of the Write attribute of an
5233 -- Unchecked_Union type. However, if the 'Write reference is
5234 -- within the generated Output stream procedure, Write outputs
5235 -- the components, and the default values of the discriminant
5236 -- are streamed by the Output procedure itself.
5238 if Is_Unchecked_Union (Base_Type (U_Type))
5239 and not Is_TSS (Current_Scope, TSS_Stream_Output)
5242 Make_Raise_Program_Error (Loc,
5243 Reason => PE_Unchecked_Union_Restriction));
5246 if Has_Discriminants (U_Type)
5248 (Discriminant_Default_Value (First_Discriminant (U_Type)))
5250 Build_Mutable_Record_Write_Procedure
5251 (Loc, Full_Base (U_Type), Decl, Pname);
5253 Build_Record_Write_Procedure
5254 (Loc, Full_Base (U_Type), Decl, Pname);
5257 Insert_Action (N, Decl);
5261 -- If we fall through, Pname is the procedure to be called
5263 Rewrite_Stream_Proc_Call (Pname);
5266 -- Component_Size is handled by the back end, unless the component size
5267 -- is known at compile time, which is always true in the packed array
5268 -- case. It is important that the packed array case is handled in the
5269 -- front end (see Eval_Attribute) since the back end would otherwise get
5270 -- confused by the equivalent packed array type.
5272 when Attribute_Component_Size =>
5275 -- The following attributes are handled by the back end (except that
5276 -- static cases have already been evaluated during semantic processing,
5277 -- but in any case the back end should not count on this). The one bit
5278 -- of special processing required is that these attributes typically
5279 -- generate conditionals in the code, so we need to check the relevant
5282 when Attribute_Max |
5284 Check_Restriction (No_Implicit_Conditionals, N);
5286 -- The following attributes are handled by the back end (except that
5287 -- static cases have already been evaluated during semantic processing,
5288 -- but in any case the back end should not count on this).
5290 -- The back end also handles the non-class-wide cases of Size
5292 when Attribute_Bit_Order |
5293 Attribute_Code_Address |
5294 Attribute_Definite |
5295 Attribute_Null_Parameter |
5296 Attribute_Passed_By_Reference |
5297 Attribute_Pool_Address =>
5300 -- The following attributes are also handled by the back end, but return
5301 -- a universal integer result, so may need a conversion for checking
5302 -- that the result is in range.
5304 when Attribute_Aft |
5305 Attribute_Max_Alignment_For_Allocation |
5306 Attribute_Max_Size_In_Storage_Elements =>
5307 Apply_Universal_Integer_Attribute_Checks (N);
5309 -- The following attributes should not appear at this stage, since they
5310 -- have already been handled by the analyzer (and properly rewritten
5311 -- with corresponding values or entities to represent the right values)
5313 when Attribute_Abort_Signal |
5314 Attribute_Address_Size |
5317 Attribute_Compiler_Version |
5318 Attribute_Default_Bit_Order |
5325 Attribute_Fast_Math |
5326 Attribute_Has_Access_Values |
5327 Attribute_Has_Discriminants |
5328 Attribute_Has_Tagged_Values |
5330 Attribute_Machine_Emax |
5331 Attribute_Machine_Emin |
5332 Attribute_Machine_Mantissa |
5333 Attribute_Machine_Overflows |
5334 Attribute_Machine_Radix |
5335 Attribute_Machine_Rounds |
5336 Attribute_Maximum_Alignment |
5337 Attribute_Model_Emin |
5338 Attribute_Model_Epsilon |
5339 Attribute_Model_Mantissa |
5340 Attribute_Model_Small |
5342 Attribute_Partition_ID |
5344 Attribute_Safe_Emax |
5345 Attribute_Safe_First |
5346 Attribute_Safe_Large |
5347 Attribute_Safe_Last |
5348 Attribute_Safe_Small |
5350 Attribute_Signed_Zeros |
5352 Attribute_Storage_Unit |
5353 Attribute_Stub_Type |
5354 Attribute_Target_Name |
5355 Attribute_Type_Class |
5356 Attribute_Type_Key |
5357 Attribute_Unconstrained_Array |
5358 Attribute_Universal_Literal_String |
5359 Attribute_Wchar_T_Size |
5360 Attribute_Word_Size =>
5362 raise Program_Error;
5364 -- The Asm_Input and Asm_Output attributes are not expanded at this
5365 -- stage, but will be eliminated in the expansion of the Asm call, see
5366 -- Exp_Intr for details. So the back end will never see these either.
5368 when Attribute_Asm_Input |
5369 Attribute_Asm_Output =>
5376 when RE_Not_Available =>
5378 end Expand_N_Attribute_Reference;
5380 ----------------------
5381 -- Expand_Pred_Succ --
5382 ----------------------
5384 -- For typ'Pred (exp), we generate the check
5386 -- [constraint_error when exp = typ'Base'First]
5388 -- Similarly, for typ'Succ (exp), we generate the check
5390 -- [constraint_error when exp = typ'Base'Last]
5392 -- These checks are not generated for modular types, since the proper
5393 -- semantics for Succ and Pred on modular types is to wrap, not raise CE.
5395 procedure Expand_Pred_Succ (N : Node_Id) is
5396 Loc : constant Source_Ptr := Sloc (N);
5400 if Attribute_Name (N) = Name_Pred then
5407 Make_Raise_Constraint_Error (Loc,
5411 Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
5413 Make_Attribute_Reference (Loc,
5415 New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
5416 Attribute_Name => Cnam)),
5417 Reason => CE_Overflow_Check_Failed));
5418 end Expand_Pred_Succ;
5424 procedure Find_Fat_Info
5426 Fat_Type : out Entity_Id;
5427 Fat_Pkg : out RE_Id)
5429 Btyp : constant Entity_Id := Base_Type (T);
5430 Rtyp : constant Entity_Id := Root_Type (T);
5431 Digs : constant Nat := UI_To_Int (Digits_Value (Btyp));
5434 -- If the base type is VAX float, then get appropriate VAX float type
5436 if Vax_Float (Btyp) then
5439 Fat_Type := RTE (RE_Fat_VAX_F);
5440 Fat_Pkg := RE_Attr_VAX_F_Float;
5443 Fat_Type := RTE (RE_Fat_VAX_D);
5444 Fat_Pkg := RE_Attr_VAX_D_Float;
5447 Fat_Type := RTE (RE_Fat_VAX_G);
5448 Fat_Pkg := RE_Attr_VAX_G_Float;
5451 raise Program_Error;
5454 -- If root type is VAX float, this is the case where the library has
5455 -- been recompiled in VAX float mode, and we have an IEEE float type.
5456 -- This is when we use the special IEEE Fat packages.
5458 elsif Vax_Float (Rtyp) then
5461 Fat_Type := RTE (RE_Fat_IEEE_Short);
5462 Fat_Pkg := RE_Attr_IEEE_Short;
5465 Fat_Type := RTE (RE_Fat_IEEE_Long);
5466 Fat_Pkg := RE_Attr_IEEE_Long;
5469 raise Program_Error;
5472 -- If neither the base type nor the root type is VAX_Native then VAX
5473 -- float is out of the picture, and we can just use the root type.
5478 if Fat_Type = Standard_Short_Float then
5479 Fat_Pkg := RE_Attr_Short_Float;
5481 elsif Fat_Type = Standard_Float then
5482 Fat_Pkg := RE_Attr_Float;
5484 elsif Fat_Type = Standard_Long_Float then
5485 Fat_Pkg := RE_Attr_Long_Float;
5487 elsif Fat_Type = Standard_Long_Long_Float then
5488 Fat_Pkg := RE_Attr_Long_Long_Float;
5490 -- Universal real (which is its own root type) is treated as being
5491 -- equivalent to Standard.Long_Long_Float, since it is defined to
5492 -- have the same precision as the longest Float type.
5494 elsif Fat_Type = Universal_Real then
5495 Fat_Type := Standard_Long_Long_Float;
5496 Fat_Pkg := RE_Attr_Long_Long_Float;
5499 raise Program_Error;
5504 ----------------------------
5505 -- Find_Stream_Subprogram --
5506 ----------------------------
5508 function Find_Stream_Subprogram
5510 Nam : TSS_Name_Type) return Entity_Id
5512 Base_Typ : constant Entity_Id := Base_Type (Typ);
5513 Ent : constant Entity_Id := TSS (Typ, Nam);
5516 if Present (Ent) then
5520 -- Stream attributes for strings are expanded into library calls. The
5521 -- following checks are disabled when the run-time is not available or
5522 -- when compiling predefined types due to bootstrap issues. As a result,
5523 -- the compiler will generate in-place stream routines for string types
5524 -- that appear in GNAT's library, but will generate calls via rtsfind
5525 -- to library routines for user code.
5527 -- ??? For now, disable this code for JVM, since this generates a
5528 -- VerifyError exception at run time on e.g. c330001.
5530 -- This is disabled for AAMP, to avoid creating dependences on files not
5531 -- supported in the AAMP library (such as s-fileio.adb).
5533 if VM_Target /= JVM_Target
5534 and then not AAMP_On_Target
5536 not Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
5538 -- String as defined in package Ada
5540 if Base_Typ = Standard_String then
5541 if Restriction_Active (No_Stream_Optimizations) then
5542 if Nam = TSS_Stream_Input then
5543 return RTE (RE_String_Input);
5545 elsif Nam = TSS_Stream_Output then
5546 return RTE (RE_String_Output);
5548 elsif Nam = TSS_Stream_Read then
5549 return RTE (RE_String_Read);
5551 else pragma Assert (Nam = TSS_Stream_Write);
5552 return RTE (RE_String_Write);
5556 if Nam = TSS_Stream_Input then
5557 return RTE (RE_String_Input_Blk_IO);
5559 elsif Nam = TSS_Stream_Output then
5560 return RTE (RE_String_Output_Blk_IO);
5562 elsif Nam = TSS_Stream_Read then
5563 return RTE (RE_String_Read_Blk_IO);
5565 else pragma Assert (Nam = TSS_Stream_Write);
5566 return RTE (RE_String_Write_Blk_IO);
5570 -- Wide_String as defined in package Ada
5572 elsif Base_Typ = Standard_Wide_String then
5573 if Restriction_Active (No_Stream_Optimizations) then
5574 if Nam = TSS_Stream_Input then
5575 return RTE (RE_Wide_String_Input);
5577 elsif Nam = TSS_Stream_Output then
5578 return RTE (RE_Wide_String_Output);
5580 elsif Nam = TSS_Stream_Read then
5581 return RTE (RE_Wide_String_Read);
5583 else pragma Assert (Nam = TSS_Stream_Write);
5584 return RTE (RE_Wide_String_Write);
5588 if Nam = TSS_Stream_Input then
5589 return RTE (RE_Wide_String_Input_Blk_IO);
5591 elsif Nam = TSS_Stream_Output then
5592 return RTE (RE_Wide_String_Output_Blk_IO);
5594 elsif Nam = TSS_Stream_Read then
5595 return RTE (RE_Wide_String_Read_Blk_IO);
5597 else pragma Assert (Nam = TSS_Stream_Write);
5598 return RTE (RE_Wide_String_Write_Blk_IO);
5602 -- Wide_Wide_String as defined in package Ada
5604 elsif Base_Typ = Standard_Wide_Wide_String then
5605 if Restriction_Active (No_Stream_Optimizations) then
5606 if Nam = TSS_Stream_Input then
5607 return RTE (RE_Wide_Wide_String_Input);
5609 elsif Nam = TSS_Stream_Output then
5610 return RTE (RE_Wide_Wide_String_Output);
5612 elsif Nam = TSS_Stream_Read then
5613 return RTE (RE_Wide_Wide_String_Read);
5615 else pragma Assert (Nam = TSS_Stream_Write);
5616 return RTE (RE_Wide_Wide_String_Write);
5620 if Nam = TSS_Stream_Input then
5621 return RTE (RE_Wide_Wide_String_Input_Blk_IO);
5623 elsif Nam = TSS_Stream_Output then
5624 return RTE (RE_Wide_Wide_String_Output_Blk_IO);
5626 elsif Nam = TSS_Stream_Read then
5627 return RTE (RE_Wide_Wide_String_Read_Blk_IO);
5629 else pragma Assert (Nam = TSS_Stream_Write);
5630 return RTE (RE_Wide_Wide_String_Write_Blk_IO);
5636 if Is_Tagged_Type (Typ)
5637 and then Is_Derived_Type (Typ)
5639 return Find_Prim_Op (Typ, Nam);
5641 return Find_Inherited_TSS (Typ, Nam);
5643 end Find_Stream_Subprogram;
5649 function Full_Base (T : Entity_Id) return Entity_Id is
5653 BT := Base_Type (T);
5655 if Is_Private_Type (BT)
5656 and then Present (Full_View (BT))
5658 BT := Full_View (BT);
5664 -----------------------
5665 -- Get_Index_Subtype --
5666 -----------------------
5668 function Get_Index_Subtype (N : Node_Id) return Node_Id is
5669 P_Type : Entity_Id := Etype (Prefix (N));
5674 if Is_Access_Type (P_Type) then
5675 P_Type := Designated_Type (P_Type);
5678 if No (Expressions (N)) then
5681 J := UI_To_Int (Expr_Value (First (Expressions (N))));
5684 Indx := First_Index (P_Type);
5690 return Etype (Indx);
5691 end Get_Index_Subtype;
5693 -------------------------------
5694 -- Get_Stream_Convert_Pragma --
5695 -------------------------------
5697 function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id is
5702 -- Note: we cannot use Get_Rep_Pragma here because of the peculiarity
5703 -- that a stream convert pragma for a tagged type is not inherited from
5704 -- its parent. Probably what is wrong here is that it is basically
5705 -- incorrect to consider a stream convert pragma to be a representation
5706 -- pragma at all ???
5708 N := First_Rep_Item (Implementation_Base_Type (T));
5709 while Present (N) loop
5710 if Nkind (N) = N_Pragma
5711 and then Pragma_Name (N) = Name_Stream_Convert
5713 -- For tagged types this pragma is not inherited, so we
5714 -- must verify that it is defined for the given type and
5718 Entity (Expression (First (Pragma_Argument_Associations (N))));
5720 if not Is_Tagged_Type (T)
5722 or else (Is_Private_Type (Typ) and then T = Full_View (Typ))
5732 end Get_Stream_Convert_Pragma;
5734 ---------------------------------
5735 -- Is_Constrained_Packed_Array --
5736 ---------------------------------
5738 function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
5739 Arr : Entity_Id := Typ;
5742 if Is_Access_Type (Arr) then
5743 Arr := Designated_Type (Arr);
5746 return Is_Array_Type (Arr)
5747 and then Is_Constrained (Arr)
5748 and then Present (Packed_Array_Type (Arr));
5749 end Is_Constrained_Packed_Array;
5751 ----------------------------------------
5752 -- Is_Inline_Floating_Point_Attribute --
5753 ----------------------------------------
5755 function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean is
5756 Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
5759 if Nkind (Parent (N)) /= N_Type_Conversion
5760 or else not Is_Integer_Type (Etype (Parent (N)))
5765 -- Should also support 'Machine_Rounding and 'Unbiased_Rounding, but
5766 -- required back end support has not been implemented yet ???
5768 return Id = Attribute_Truncation;
5769 end Is_Inline_Floating_Point_Attribute;
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