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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Aggr; use Exp_Aggr;
33 with Exp_Atag; use Exp_Atag;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Fixd; use Exp_Fixd;
40 with Exp_Intr; use Exp_Intr;
41 with Exp_Pakd; use Exp_Pakd;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Exp_VFpt; use Exp_VFpt;
45 with Freeze; use Freeze;
46 with Inline; use Inline;
47 with Namet; use Namet;
48 with Nlists; use Nlists;
49 with Nmake; use Nmake;
51 with Par_SCO; use Par_SCO;
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_Cat; use Sem_Cat;
58 with Sem_Ch3; use Sem_Ch3;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Type; use Sem_Type;
64 with Sem_Util; use Sem_Util;
65 with Sem_Warn; use Sem_Warn;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Stand; use Stand;
69 with SCIL_LL; use SCIL_LL;
70 with Targparm; use Targparm;
71 with Tbuild; use Tbuild;
72 with Ttypes; use Ttypes;
73 with Uintp; use Uintp;
74 with Urealp; use Urealp;
75 with Validsw; use Validsw;
77 package body Exp_Ch4 is
79 -----------------------
80 -- Local Subprograms --
81 -----------------------
83 procedure Binary_Op_Validity_Checks (N : Node_Id);
84 pragma Inline (Binary_Op_Validity_Checks);
85 -- Performs validity checks for a binary operator
87 procedure Build_Boolean_Array_Proc_Call
91 -- If a boolean array assignment can be done in place, build call to
92 -- corresponding library procedure.
94 procedure Displace_Allocator_Pointer (N : Node_Id);
95 -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
96 -- Expand_Allocator_Expression. Allocating class-wide interface objects
97 -- this routine displaces the pointer to the allocated object to reference
98 -- the component referencing the corresponding secondary dispatch table.
100 procedure Expand_Allocator_Expression (N : Node_Id);
101 -- Subsidiary to Expand_N_Allocator, for the case when the expression
102 -- is a qualified expression or an aggregate.
104 procedure Expand_Array_Comparison (N : Node_Id);
105 -- This routine handles expansion of the comparison operators (N_Op_Lt,
106 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
107 -- code for these operators is similar, differing only in the details of
108 -- the actual comparison call that is made. Special processing (call a
111 function Expand_Array_Equality
116 Typ : Entity_Id) return Node_Id;
117 -- Expand an array equality into a call to a function implementing this
118 -- equality, and a call to it. Loc is the location for the generated nodes.
119 -- Lhs and Rhs are the array expressions to be compared. Bodies is a list
120 -- on which to attach bodies of local functions that are created in the
121 -- process. It is the responsibility of the caller to insert those bodies
122 -- at the right place. Nod provides the Sloc value for the generated code.
123 -- Normally the types used for the generated equality routine are taken
124 -- from Lhs and Rhs. However, in some situations of generated code, the
125 -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
126 -- the type to be used for the formal parameters.
128 procedure Expand_Boolean_Operator (N : Node_Id);
129 -- Common expansion processing for Boolean operators (And, Or, Xor) for the
130 -- case of array type arguments.
132 procedure Expand_Short_Circuit_Operator (N : Node_Id);
133 -- Common expansion processing for short-circuit boolean operators
135 function Expand_Composite_Equality
140 Bodies : List_Id) return Node_Id;
141 -- Local recursive function used to expand equality for nested composite
142 -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
143 -- to attach bodies of local functions that are created in the process.
144 -- This is the responsibility of the caller to insert those bodies at the
145 -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs
146 -- are the left and right sides for the comparison, and Typ is the type of
147 -- the arrays to compare.
149 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id);
150 -- Routine to expand concatenation of a sequence of two or more operands
151 -- (in the list Operands) and replace node Cnode with the result of the
152 -- concatenation. The operands can be of any appropriate type, and can
153 -- include both arrays and singleton elements.
155 procedure Fixup_Universal_Fixed_Operation (N : Node_Id);
156 -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
157 -- fixed. We do not have such a type at runtime, so the purpose of this
158 -- routine is to find the real type by looking up the tree. We also
159 -- determine if the operation must be rounded.
161 function Get_Allocator_Final_List
164 PtrT : Entity_Id) return Entity_Id;
165 -- If the designated type is controlled, build final_list expression for
166 -- created object. If context is an access parameter, create a local access
167 -- type to have a usable finalization list.
169 function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
170 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
171 -- discriminants if it has a constrained nominal type, unless the object
172 -- is a component of an enclosing Unchecked_Union object that is subject
173 -- to a per-object constraint and the enclosing object lacks inferable
176 -- An expression of an Unchecked_Union type has inferable discriminants
177 -- if it is either a name of an object with inferable discriminants or a
178 -- qualified expression whose subtype mark denotes a constrained subtype.
180 procedure Insert_Dereference_Action (N : Node_Id);
181 -- N is an expression whose type is an access. When the type of the
182 -- associated storage pool is derived from Checked_Pool, generate a
183 -- call to the 'Dereference' primitive operation.
185 function Make_Array_Comparison_Op
187 Nod : Node_Id) return Node_Id;
188 -- Comparisons between arrays are expanded in line. This function produces
189 -- the body of the implementation of (a > b), where a and b are one-
190 -- dimensional arrays of some discrete type. The original node is then
191 -- expanded into the appropriate call to this function. Nod provides the
192 -- Sloc value for the generated code.
194 function Make_Boolean_Array_Op
196 N : Node_Id) return Node_Id;
197 -- Boolean operations on boolean arrays are expanded in line. This function
198 -- produce the body for the node N, which is (a and b), (a or b), or (a xor
199 -- b). It is used only the normal case and not the packed case. The type
200 -- involved, Typ, is the Boolean array type, and the logical operations in
201 -- the body are simple boolean operations. Note that Typ is always a
202 -- constrained type (the caller has ensured this by using
203 -- Convert_To_Actual_Subtype if necessary).
205 procedure Rewrite_Comparison (N : Node_Id);
206 -- If N is the node for a comparison whose outcome can be determined at
207 -- compile time, then the node N can be rewritten with True or False. If
208 -- the outcome cannot be determined at compile time, the call has no
209 -- effect. If N is a type conversion, then this processing is applied to
210 -- its expression. If N is neither comparison nor a type conversion, the
211 -- call has no effect.
213 procedure Tagged_Membership
215 SCIL_Node : out Node_Id;
216 Result : out Node_Id);
217 -- Construct the expression corresponding to the tagged membership test.
218 -- Deals with a second operand being (or not) a class-wide type.
220 function Safe_In_Place_Array_Op
223 Op2 : Node_Id) return Boolean;
224 -- In the context of an assignment, where the right-hand side is a boolean
225 -- operation on arrays, check whether operation can be performed in place.
227 procedure Unary_Op_Validity_Checks (N : Node_Id);
228 pragma Inline (Unary_Op_Validity_Checks);
229 -- Performs validity checks for a unary operator
231 -------------------------------
232 -- Binary_Op_Validity_Checks --
233 -------------------------------
235 procedure Binary_Op_Validity_Checks (N : Node_Id) is
237 if Validity_Checks_On and Validity_Check_Operands then
238 Ensure_Valid (Left_Opnd (N));
239 Ensure_Valid (Right_Opnd (N));
241 end Binary_Op_Validity_Checks;
243 ------------------------------------
244 -- Build_Boolean_Array_Proc_Call --
245 ------------------------------------
247 procedure Build_Boolean_Array_Proc_Call
252 Loc : constant Source_Ptr := Sloc (N);
253 Kind : constant Node_Kind := Nkind (Expression (N));
254 Target : constant Node_Id :=
255 Make_Attribute_Reference (Loc,
257 Attribute_Name => Name_Address);
259 Arg1 : Node_Id := Op1;
260 Arg2 : Node_Id := Op2;
262 Proc_Name : Entity_Id;
265 if Kind = N_Op_Not then
266 if Nkind (Op1) in N_Binary_Op then
268 -- Use negated version of the binary operators
270 if Nkind (Op1) = N_Op_And then
271 Proc_Name := RTE (RE_Vector_Nand);
273 elsif Nkind (Op1) = N_Op_Or then
274 Proc_Name := RTE (RE_Vector_Nor);
276 else pragma Assert (Nkind (Op1) = N_Op_Xor);
277 Proc_Name := RTE (RE_Vector_Xor);
281 Make_Procedure_Call_Statement (Loc,
282 Name => New_Occurrence_Of (Proc_Name, Loc),
284 Parameter_Associations => New_List (
286 Make_Attribute_Reference (Loc,
287 Prefix => Left_Opnd (Op1),
288 Attribute_Name => Name_Address),
290 Make_Attribute_Reference (Loc,
291 Prefix => Right_Opnd (Op1),
292 Attribute_Name => Name_Address),
294 Make_Attribute_Reference (Loc,
295 Prefix => Left_Opnd (Op1),
296 Attribute_Name => Name_Length)));
299 Proc_Name := RTE (RE_Vector_Not);
302 Make_Procedure_Call_Statement (Loc,
303 Name => New_Occurrence_Of (Proc_Name, Loc),
304 Parameter_Associations => New_List (
307 Make_Attribute_Reference (Loc,
309 Attribute_Name => Name_Address),
311 Make_Attribute_Reference (Loc,
313 Attribute_Name => Name_Length)));
317 -- We use the following equivalences:
319 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
320 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
321 -- (not X) xor (not Y) = X xor Y
322 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
324 if Nkind (Op1) = N_Op_Not then
325 Arg1 := Right_Opnd (Op1);
326 Arg2 := Right_Opnd (Op2);
327 if Kind = N_Op_And then
328 Proc_Name := RTE (RE_Vector_Nor);
329 elsif Kind = N_Op_Or then
330 Proc_Name := RTE (RE_Vector_Nand);
332 Proc_Name := RTE (RE_Vector_Xor);
336 if Kind = N_Op_And then
337 Proc_Name := RTE (RE_Vector_And);
338 elsif Kind = N_Op_Or then
339 Proc_Name := RTE (RE_Vector_Or);
340 elsif Nkind (Op2) = N_Op_Not then
341 Proc_Name := RTE (RE_Vector_Nxor);
342 Arg2 := Right_Opnd (Op2);
344 Proc_Name := RTE (RE_Vector_Xor);
349 Make_Procedure_Call_Statement (Loc,
350 Name => New_Occurrence_Of (Proc_Name, Loc),
351 Parameter_Associations => New_List (
353 Make_Attribute_Reference (Loc,
355 Attribute_Name => Name_Address),
356 Make_Attribute_Reference (Loc,
358 Attribute_Name => Name_Address),
359 Make_Attribute_Reference (Loc,
361 Attribute_Name => Name_Length)));
364 Rewrite (N, Call_Node);
368 when RE_Not_Available =>
370 end Build_Boolean_Array_Proc_Call;
372 --------------------------------
373 -- Displace_Allocator_Pointer --
374 --------------------------------
376 procedure Displace_Allocator_Pointer (N : Node_Id) is
377 Loc : constant Source_Ptr := Sloc (N);
378 Orig_Node : constant Node_Id := Original_Node (N);
384 -- Do nothing in case of VM targets: the virtual machine will handle
385 -- interfaces directly.
387 if not Tagged_Type_Expansion then
391 pragma Assert (Nkind (N) = N_Identifier
392 and then Nkind (Orig_Node) = N_Allocator);
394 PtrT := Etype (Orig_Node);
395 Dtyp := Available_View (Designated_Type (PtrT));
396 Etyp := Etype (Expression (Orig_Node));
398 if Is_Class_Wide_Type (Dtyp)
399 and then Is_Interface (Dtyp)
401 -- If the type of the allocator expression is not an interface type
402 -- we can generate code to reference the record component containing
403 -- the pointer to the secondary dispatch table.
405 if not Is_Interface (Etyp) then
407 Saved_Typ : constant Entity_Id := Etype (Orig_Node);
410 -- 1) Get access to the allocated object
413 Make_Explicit_Dereference (Loc,
418 -- 2) Add the conversion to displace the pointer to reference
419 -- the secondary dispatch table.
421 Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
422 Analyze_And_Resolve (N, Dtyp);
424 -- 3) The 'access to the secondary dispatch table will be used
425 -- as the value returned by the allocator.
428 Make_Attribute_Reference (Loc,
429 Prefix => Relocate_Node (N),
430 Attribute_Name => Name_Access));
431 Set_Etype (N, Saved_Typ);
435 -- If the type of the allocator expression is an interface type we
436 -- generate a run-time call to displace "this" to reference the
437 -- component containing the pointer to the secondary dispatch table
438 -- or else raise Constraint_Error if the actual object does not
439 -- implement the target interface. This case corresponds with the
440 -- following example:
442 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
444 -- return new Iface_2'Class'(Obj);
449 Unchecked_Convert_To (PtrT,
450 Make_Function_Call (Loc,
451 Name => New_Reference_To (RTE (RE_Displace), Loc),
452 Parameter_Associations => New_List (
453 Unchecked_Convert_To (RTE (RE_Address),
459 (Access_Disp_Table (Etype (Base_Type (Dtyp))))),
461 Analyze_And_Resolve (N, PtrT);
464 end Displace_Allocator_Pointer;
466 ---------------------------------
467 -- Expand_Allocator_Expression --
468 ---------------------------------
470 procedure Expand_Allocator_Expression (N : Node_Id) is
471 Loc : constant Source_Ptr := Sloc (N);
472 Exp : constant Node_Id := Expression (Expression (N));
473 PtrT : constant Entity_Id := Etype (N);
474 DesigT : constant Entity_Id := Designated_Type (PtrT);
476 procedure Apply_Accessibility_Check
478 Built_In_Place : Boolean := False);
479 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
480 -- type, generate an accessibility check to verify that the level of the
481 -- type of the created object is not deeper than the level of the access
482 -- type. If the type of the qualified expression is class- wide, then
483 -- always generate the check (except in the case where it is known to be
484 -- unnecessary, see comment below). Otherwise, only generate the check
485 -- if the level of the qualified expression type is statically deeper
486 -- than the access type.
488 -- Although the static accessibility will generally have been performed
489 -- as a legality check, it won't have been done in cases where the
490 -- allocator appears in generic body, so a run-time check is needed in
491 -- general. One special case is when the access type is declared in the
492 -- same scope as the class-wide allocator, in which case the check can
493 -- never fail, so it need not be generated.
495 -- As an open issue, there seem to be cases where the static level
496 -- associated with the class-wide object's underlying type is not
497 -- sufficient to perform the proper accessibility check, such as for
498 -- allocators in nested subprograms or accept statements initialized by
499 -- class-wide formals when the actual originates outside at a deeper
500 -- static level. The nested subprogram case might require passing
501 -- accessibility levels along with class-wide parameters, and the task
502 -- case seems to be an actual gap in the language rules that needs to
503 -- be fixed by the ARG. ???
505 -------------------------------
506 -- Apply_Accessibility_Check --
507 -------------------------------
509 procedure Apply_Accessibility_Check
511 Built_In_Place : Boolean := False)
516 -- Note: we skip the accessibility check for the VM case, since
517 -- there does not seem to be any practical way of implementing it.
519 if Ada_Version >= Ada_2005
520 and then Tagged_Type_Expansion
521 and then Is_Class_Wide_Type (DesigT)
522 and then not Scope_Suppress (Accessibility_Check)
524 (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
526 (Is_Class_Wide_Type (Etype (Exp))
527 and then Scope (PtrT) /= Current_Scope))
529 -- If the allocator was built in place Ref is already a reference
530 -- to the access object initialized to the result of the allocator
531 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise
532 -- it is the entity associated with the object containing the
533 -- address of the allocated object.
535 if Built_In_Place then
536 Ref_Node := New_Copy (Ref);
538 Ref_Node := New_Reference_To (Ref, Loc);
542 Make_Raise_Program_Error (Loc,
546 Build_Get_Access_Level (Loc,
547 Make_Attribute_Reference (Loc,
549 Attribute_Name => Name_Tag)),
551 Make_Integer_Literal (Loc,
552 Type_Access_Level (PtrT))),
553 Reason => PE_Accessibility_Check_Failed));
555 end Apply_Accessibility_Check;
559 Indic : constant Node_Id := Subtype_Mark (Expression (N));
560 T : constant Entity_Id := Entity (Indic);
565 TagT : Entity_Id := Empty;
566 -- Type used as source for tag assignment
568 TagR : Node_Id := Empty;
569 -- Target reference for tag assignment
571 Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
573 Tag_Assign : Node_Id;
576 -- Start of processing for Expand_Allocator_Expression
579 if Is_Tagged_Type (T) or else Needs_Finalization (T) then
581 if Is_CPP_Constructor_Call (Exp) then
584 -- Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn
586 -- Allocate the object with no expression
588 Node := Relocate_Node (N);
589 Set_Expression (Node, New_Reference_To (Etype (Exp), Loc));
591 -- Avoid its expansion to avoid generating a call to the default
596 Temp := Make_Temporary (Loc, 'P', N);
599 Make_Object_Declaration (Loc,
600 Defining_Identifier => Temp,
601 Constant_Present => True,
602 Object_Definition => New_Reference_To (PtrT, Loc),
603 Expression => Node));
605 Apply_Accessibility_Check (Temp);
607 -- Locate the enclosing list and insert the C++ constructor call
614 while not Is_List_Member (P) loop
618 Insert_List_After_And_Analyze (P,
619 Build_Initialization_Call (Loc,
621 Make_Explicit_Dereference (Loc,
622 Prefix => New_Reference_To (Temp, Loc)),
624 Constructor_Ref => Exp));
627 Rewrite (N, New_Reference_To (Temp, Loc));
628 Analyze_And_Resolve (N, PtrT);
632 -- Ada 2005 (AI-318-02): If the initialization expression is a call
633 -- to a build-in-place function, then access to the allocated object
634 -- must be passed to the function. Currently we limit such functions
635 -- to those with constrained limited result subtypes, but eventually
636 -- we plan to expand the allowed forms of functions that are treated
637 -- as build-in-place.
639 if Ada_Version >= Ada_2005
640 and then Is_Build_In_Place_Function_Call (Exp)
642 Make_Build_In_Place_Call_In_Allocator (N, Exp);
643 Apply_Accessibility_Check (N, Built_In_Place => True);
647 -- Actions inserted before:
648 -- Temp : constant ptr_T := new T'(Expression);
649 -- <no CW> Temp._tag := T'tag;
650 -- <CTRL> Adjust (Finalizable (Temp.all));
651 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
653 -- We analyze by hand the new internal allocator to avoid
654 -- any recursion and inappropriate call to Initialize
656 -- We don't want to remove side effects when the expression must be
657 -- built in place. In the case of a build-in-place function call,
658 -- that could lead to a duplication of the call, which was already
659 -- substituted for the allocator.
661 if not Aggr_In_Place then
662 Remove_Side_Effects (Exp);
665 Temp := Make_Temporary (Loc, 'P', N);
667 -- For a class wide allocation generate the following code:
669 -- type Equiv_Record is record ... end record;
670 -- implicit subtype CW is <Class_Wide_Subytpe>;
671 -- temp : PtrT := new CW'(CW!(expr));
673 if Is_Class_Wide_Type (T) then
674 Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
676 -- Ada 2005 (AI-251): If the expression is a class-wide interface
677 -- object we generate code to move up "this" to reference the
678 -- base of the object before allocating the new object.
680 -- Note that Exp'Address is recursively expanded into a call
681 -- to Base_Address (Exp.Tag)
683 if Is_Class_Wide_Type (Etype (Exp))
684 and then Is_Interface (Etype (Exp))
685 and then Tagged_Type_Expansion
689 Unchecked_Convert_To (Entity (Indic),
690 Make_Explicit_Dereference (Loc,
691 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
692 Make_Attribute_Reference (Loc,
694 Attribute_Name => Name_Address)))));
699 Unchecked_Convert_To (Entity (Indic), Exp));
702 Analyze_And_Resolve (Expression (N), Entity (Indic));
705 -- Keep separate the management of allocators returning interfaces
707 if not Is_Interface (Directly_Designated_Type (PtrT)) then
708 if Aggr_In_Place then
710 Make_Object_Declaration (Loc,
711 Defining_Identifier => Temp,
712 Object_Definition => New_Reference_To (PtrT, Loc),
715 New_Reference_To (Etype (Exp), Loc)));
717 -- Copy the Comes_From_Source flag for the allocator we just
718 -- built, since logically this allocator is a replacement of
719 -- the original allocator node. This is for proper handling of
720 -- restriction No_Implicit_Heap_Allocations.
722 Set_Comes_From_Source
723 (Expression (Tmp_Node), Comes_From_Source (N));
725 Set_No_Initialization (Expression (Tmp_Node));
726 Insert_Action (N, Tmp_Node);
728 if Needs_Finalization (T)
729 and then Ekind (PtrT) = E_Anonymous_Access_Type
731 -- Create local finalization list for access parameter
733 Flist := Get_Allocator_Final_List (N, Base_Type (T), PtrT);
736 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
739 Node := Relocate_Node (N);
742 Make_Object_Declaration (Loc,
743 Defining_Identifier => Temp,
744 Constant_Present => True,
745 Object_Definition => New_Reference_To (PtrT, Loc),
746 Expression => Node));
749 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
750 -- interface type. In this case we use the type of the qualified
751 -- expression to allocate the object.
755 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
760 Make_Full_Type_Declaration (Loc,
761 Defining_Identifier => Def_Id,
763 Make_Access_To_Object_Definition (Loc,
765 Null_Exclusion_Present => False,
766 Constant_Present => False,
767 Subtype_Indication =>
768 New_Reference_To (Etype (Exp), Loc)));
770 Insert_Action (N, New_Decl);
772 -- Inherit the final chain to ensure that the expansion of the
773 -- aggregate is correct in case of controlled types
775 if Needs_Finalization (Directly_Designated_Type (PtrT)) then
776 Set_Associated_Final_Chain (Def_Id,
777 Associated_Final_Chain (PtrT));
780 -- Declare the object using the previous type declaration
782 if Aggr_In_Place then
784 Make_Object_Declaration (Loc,
785 Defining_Identifier => Temp,
786 Object_Definition => New_Reference_To (Def_Id, Loc),
789 New_Reference_To (Etype (Exp), Loc)));
791 -- Copy the Comes_From_Source flag for the allocator we just
792 -- built, since logically this allocator is a replacement of
793 -- the original allocator node. This is for proper handling
794 -- of restriction No_Implicit_Heap_Allocations.
796 Set_Comes_From_Source
797 (Expression (Tmp_Node), Comes_From_Source (N));
799 Set_No_Initialization (Expression (Tmp_Node));
800 Insert_Action (N, Tmp_Node);
802 if Needs_Finalization (T)
803 and then Ekind (PtrT) = E_Anonymous_Access_Type
805 -- Create local finalization list for access parameter
808 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
811 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
813 Node := Relocate_Node (N);
816 Make_Object_Declaration (Loc,
817 Defining_Identifier => Temp,
818 Constant_Present => True,
819 Object_Definition => New_Reference_To (Def_Id, Loc),
820 Expression => Node));
823 -- Generate an additional object containing the address of the
824 -- returned object. The type of this second object declaration
825 -- is the correct type required for the common processing that
826 -- is still performed by this subprogram. The displacement of
827 -- this pointer to reference the component associated with the
828 -- interface type will be done at the end of common processing.
831 Make_Object_Declaration (Loc,
832 Defining_Identifier => Make_Temporary (Loc, 'P'),
833 Object_Definition => New_Reference_To (PtrT, Loc),
834 Expression => Unchecked_Convert_To (PtrT,
835 New_Reference_To (Temp, Loc)));
837 Insert_Action (N, New_Decl);
839 Tmp_Node := New_Decl;
840 Temp := Defining_Identifier (New_Decl);
844 Apply_Accessibility_Check (Temp);
846 -- Generate the tag assignment
848 -- Suppress the tag assignment when VM_Target because VM tags are
849 -- represented implicitly in objects.
851 if not Tagged_Type_Expansion then
854 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
855 -- interface objects because in this case the tag does not change.
857 elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
858 pragma Assert (Is_Class_Wide_Type
859 (Directly_Designated_Type (Etype (N))));
862 elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
864 TagR := New_Reference_To (Temp, Loc);
866 elsif Is_Private_Type (T)
867 and then Is_Tagged_Type (Underlying_Type (T))
869 TagT := Underlying_Type (T);
871 Unchecked_Convert_To (Underlying_Type (T),
872 Make_Explicit_Dereference (Loc,
873 Prefix => New_Reference_To (Temp, Loc)));
876 if Present (TagT) then
878 Make_Assignment_Statement (Loc,
880 Make_Selected_Component (Loc,
883 New_Reference_To (First_Tag_Component (TagT), Loc)),
886 Unchecked_Convert_To (RTE (RE_Tag),
888 (Elists.Node (First_Elmt (Access_Disp_Table (TagT))),
891 -- The previous assignment has to be done in any case
893 Set_Assignment_OK (Name (Tag_Assign));
894 Insert_Action (N, Tag_Assign);
897 if Needs_Finalization (DesigT)
898 and then Needs_Finalization (T)
902 Apool : constant Entity_Id :=
903 Associated_Storage_Pool (PtrT);
906 -- If it is an allocation on the secondary stack (i.e. a value
907 -- returned from a function), the object is attached on the
908 -- caller side as soon as the call is completed (see
909 -- Expand_Ctrl_Function_Call)
911 if Is_RTE (Apool, RE_SS_Pool) then
913 F : constant Entity_Id := Make_Temporary (Loc, 'F');
916 Make_Object_Declaration (Loc,
917 Defining_Identifier => F,
919 New_Reference_To (RTE (RE_Finalizable_Ptr), Loc)));
920 Flist := New_Reference_To (F, Loc);
921 Attach := Make_Integer_Literal (Loc, 1);
924 -- Normal case, not a secondary stack allocation
927 if Needs_Finalization (T)
928 and then Ekind (PtrT) = E_Anonymous_Access_Type
930 -- Create local finalization list for access parameter
933 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
935 Flist := Find_Final_List (PtrT);
938 Attach := Make_Integer_Literal (Loc, 2);
941 -- Generate an Adjust call if the object will be moved. In Ada
942 -- 2005, the object may be inherently limited, in which case
943 -- there is no Adjust procedure, and the object is built in
944 -- place. In Ada 95, the object can be limited but not
945 -- inherently limited if this allocator came from a return
946 -- statement (we're allocating the result on the secondary
947 -- stack). In that case, the object will be moved, so we _do_
951 and then not Is_Immutably_Limited_Type (T)
957 -- An unchecked conversion is needed in the classwide
958 -- case because the designated type can be an ancestor of
959 -- the subtype mark of the allocator.
961 Unchecked_Convert_To (T,
962 Make_Explicit_Dereference (Loc,
963 Prefix => New_Reference_To (Temp, Loc))),
967 With_Attach => Attach,
973 Rewrite (N, New_Reference_To (Temp, Loc));
974 Analyze_And_Resolve (N, PtrT);
976 -- Ada 2005 (AI-251): Displace the pointer to reference the record
977 -- component containing the secondary dispatch table of the interface
980 if Is_Interface (Directly_Designated_Type (PtrT)) then
981 Displace_Allocator_Pointer (N);
984 elsif Aggr_In_Place then
985 Temp := Make_Temporary (Loc, 'P', N);
987 Make_Object_Declaration (Loc,
988 Defining_Identifier => Temp,
989 Object_Definition => New_Reference_To (PtrT, Loc),
990 Expression => Make_Allocator (Loc,
991 New_Reference_To (Etype (Exp), Loc)));
993 -- Copy the Comes_From_Source flag for the allocator we just built,
994 -- since logically this allocator is a replacement of the original
995 -- allocator node. This is for proper handling of restriction
996 -- No_Implicit_Heap_Allocations.
998 Set_Comes_From_Source
999 (Expression (Tmp_Node), Comes_From_Source (N));
1001 Set_No_Initialization (Expression (Tmp_Node));
1002 Insert_Action (N, Tmp_Node);
1003 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
1004 Rewrite (N, New_Reference_To (Temp, Loc));
1005 Analyze_And_Resolve (N, PtrT);
1007 elsif Is_Access_Type (T)
1008 and then Can_Never_Be_Null (T)
1010 Install_Null_Excluding_Check (Exp);
1012 elsif Is_Access_Type (DesigT)
1013 and then Nkind (Exp) = N_Allocator
1014 and then Nkind (Expression (Exp)) /= N_Qualified_Expression
1016 -- Apply constraint to designated subtype indication
1018 Apply_Constraint_Check (Expression (Exp),
1019 Designated_Type (DesigT),
1020 No_Sliding => True);
1022 if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
1024 -- Propagate constraint_error to enclosing allocator
1026 Rewrite (Exp, New_Copy (Expression (Exp)));
1030 -- type A is access T1;
1031 -- X : A := new T2'(...);
1032 -- T1 and T2 can be different subtypes, and we might need to check
1033 -- both constraints. First check against the type of the qualified
1036 Apply_Constraint_Check (Exp, T, No_Sliding => True);
1038 if Do_Range_Check (Exp) then
1039 Set_Do_Range_Check (Exp, False);
1040 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1043 -- A check is also needed in cases where the designated subtype is
1044 -- constrained and differs from the subtype given in the qualified
1045 -- expression. Note that the check on the qualified expression does
1046 -- not allow sliding, but this check does (a relaxation from Ada 83).
1048 if Is_Constrained (DesigT)
1049 and then not Subtypes_Statically_Match (T, DesigT)
1051 Apply_Constraint_Check
1052 (Exp, DesigT, No_Sliding => False);
1054 if Do_Range_Check (Exp) then
1055 Set_Do_Range_Check (Exp, False);
1056 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1060 -- For an access to unconstrained packed array, GIGI needs to see an
1061 -- expression with a constrained subtype in order to compute the
1062 -- proper size for the allocator.
1064 if Is_Array_Type (T)
1065 and then not Is_Constrained (T)
1066 and then Is_Packed (T)
1069 ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A');
1070 Internal_Exp : constant Node_Id := Relocate_Node (Exp);
1073 Make_Subtype_Declaration (Loc,
1074 Defining_Identifier => ConstrT,
1075 Subtype_Indication =>
1076 Make_Subtype_From_Expr (Exp, T)));
1077 Freeze_Itype (ConstrT, Exp);
1078 Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
1082 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1083 -- to a build-in-place function, then access to the allocated object
1084 -- must be passed to the function. Currently we limit such functions
1085 -- to those with constrained limited result subtypes, but eventually
1086 -- we plan to expand the allowed forms of functions that are treated
1087 -- as build-in-place.
1089 if Ada_Version >= Ada_2005
1090 and then Is_Build_In_Place_Function_Call (Exp)
1092 Make_Build_In_Place_Call_In_Allocator (N, Exp);
1097 when RE_Not_Available =>
1099 end Expand_Allocator_Expression;
1101 -----------------------------
1102 -- Expand_Array_Comparison --
1103 -----------------------------
1105 -- Expansion is only required in the case of array types. For the unpacked
1106 -- case, an appropriate runtime routine is called. For packed cases, and
1107 -- also in some other cases where a runtime routine cannot be called, the
1108 -- form of the expansion is:
1110 -- [body for greater_nn; boolean_expression]
1112 -- The body is built by Make_Array_Comparison_Op, and the form of the
1113 -- Boolean expression depends on the operator involved.
1115 procedure Expand_Array_Comparison (N : Node_Id) is
1116 Loc : constant Source_Ptr := Sloc (N);
1117 Op1 : Node_Id := Left_Opnd (N);
1118 Op2 : Node_Id := Right_Opnd (N);
1119 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
1120 Ctyp : constant Entity_Id := Component_Type (Typ1);
1123 Func_Body : Node_Id;
1124 Func_Name : Entity_Id;
1128 Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
1129 -- True for byte addressable target
1131 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
1132 -- Returns True if the length of the given operand is known to be less
1133 -- than 4. Returns False if this length is known to be four or greater
1134 -- or is not known at compile time.
1136 ------------------------
1137 -- Length_Less_Than_4 --
1138 ------------------------
1140 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
1141 Otyp : constant Entity_Id := Etype (Opnd);
1144 if Ekind (Otyp) = E_String_Literal_Subtype then
1145 return String_Literal_Length (Otyp) < 4;
1149 Ityp : constant Entity_Id := Etype (First_Index (Otyp));
1150 Lo : constant Node_Id := Type_Low_Bound (Ityp);
1151 Hi : constant Node_Id := Type_High_Bound (Ityp);
1156 if Compile_Time_Known_Value (Lo) then
1157 Lov := Expr_Value (Lo);
1162 if Compile_Time_Known_Value (Hi) then
1163 Hiv := Expr_Value (Hi);
1168 return Hiv < Lov + 3;
1171 end Length_Less_Than_4;
1173 -- Start of processing for Expand_Array_Comparison
1176 -- Deal first with unpacked case, where we can call a runtime routine
1177 -- except that we avoid this for targets for which are not addressable
1178 -- by bytes, and for the JVM/CIL, since they do not support direct
1179 -- addressing of array components.
1181 if not Is_Bit_Packed_Array (Typ1)
1182 and then Byte_Addressable
1183 and then VM_Target = No_VM
1185 -- The call we generate is:
1187 -- Compare_Array_xn[_Unaligned]
1188 -- (left'address, right'address, left'length, right'length) <op> 0
1190 -- x = U for unsigned, S for signed
1191 -- n = 8,16,32,64 for component size
1192 -- Add _Unaligned if length < 4 and component size is 8.
1193 -- <op> is the standard comparison operator
1195 if Component_Size (Typ1) = 8 then
1196 if Length_Less_Than_4 (Op1)
1198 Length_Less_Than_4 (Op2)
1200 if Is_Unsigned_Type (Ctyp) then
1201 Comp := RE_Compare_Array_U8_Unaligned;
1203 Comp := RE_Compare_Array_S8_Unaligned;
1207 if Is_Unsigned_Type (Ctyp) then
1208 Comp := RE_Compare_Array_U8;
1210 Comp := RE_Compare_Array_S8;
1214 elsif Component_Size (Typ1) = 16 then
1215 if Is_Unsigned_Type (Ctyp) then
1216 Comp := RE_Compare_Array_U16;
1218 Comp := RE_Compare_Array_S16;
1221 elsif Component_Size (Typ1) = 32 then
1222 if Is_Unsigned_Type (Ctyp) then
1223 Comp := RE_Compare_Array_U32;
1225 Comp := RE_Compare_Array_S32;
1228 else pragma Assert (Component_Size (Typ1) = 64);
1229 if Is_Unsigned_Type (Ctyp) then
1230 Comp := RE_Compare_Array_U64;
1232 Comp := RE_Compare_Array_S64;
1236 Remove_Side_Effects (Op1, Name_Req => True);
1237 Remove_Side_Effects (Op2, Name_Req => True);
1240 Make_Function_Call (Sloc (Op1),
1241 Name => New_Occurrence_Of (RTE (Comp), Loc),
1243 Parameter_Associations => New_List (
1244 Make_Attribute_Reference (Loc,
1245 Prefix => Relocate_Node (Op1),
1246 Attribute_Name => Name_Address),
1248 Make_Attribute_Reference (Loc,
1249 Prefix => Relocate_Node (Op2),
1250 Attribute_Name => Name_Address),
1252 Make_Attribute_Reference (Loc,
1253 Prefix => Relocate_Node (Op1),
1254 Attribute_Name => Name_Length),
1256 Make_Attribute_Reference (Loc,
1257 Prefix => Relocate_Node (Op2),
1258 Attribute_Name => Name_Length))));
1261 Make_Integer_Literal (Sloc (Op2),
1264 Analyze_And_Resolve (Op1, Standard_Integer);
1265 Analyze_And_Resolve (Op2, Standard_Integer);
1269 -- Cases where we cannot make runtime call
1271 -- For (a <= b) we convert to not (a > b)
1273 if Chars (N) = Name_Op_Le then
1279 Right_Opnd => Op2)));
1280 Analyze_And_Resolve (N, Standard_Boolean);
1283 -- For < the Boolean expression is
1284 -- greater__nn (op2, op1)
1286 elsif Chars (N) = Name_Op_Lt then
1287 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1291 Op1 := Right_Opnd (N);
1292 Op2 := Left_Opnd (N);
1294 -- For (a >= b) we convert to not (a < b)
1296 elsif Chars (N) = Name_Op_Ge then
1302 Right_Opnd => Op2)));
1303 Analyze_And_Resolve (N, Standard_Boolean);
1306 -- For > the Boolean expression is
1307 -- greater__nn (op1, op2)
1310 pragma Assert (Chars (N) = Name_Op_Gt);
1311 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1314 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1316 Make_Function_Call (Loc,
1317 Name => New_Reference_To (Func_Name, Loc),
1318 Parameter_Associations => New_List (Op1, Op2));
1320 Insert_Action (N, Func_Body);
1322 Analyze_And_Resolve (N, Standard_Boolean);
1325 when RE_Not_Available =>
1327 end Expand_Array_Comparison;
1329 ---------------------------
1330 -- Expand_Array_Equality --
1331 ---------------------------
1333 -- Expand an equality function for multi-dimensional arrays. Here is an
1334 -- example of such a function for Nb_Dimension = 2
1336 -- function Enn (A : atyp; B : btyp) return boolean is
1338 -- if (A'length (1) = 0 or else A'length (2) = 0)
1340 -- (B'length (1) = 0 or else B'length (2) = 0)
1342 -- return True; -- RM 4.5.2(22)
1345 -- if A'length (1) /= B'length (1)
1347 -- A'length (2) /= B'length (2)
1349 -- return False; -- RM 4.5.2(23)
1353 -- A1 : Index_T1 := A'first (1);
1354 -- B1 : Index_T1 := B'first (1);
1358 -- A2 : Index_T2 := A'first (2);
1359 -- B2 : Index_T2 := B'first (2);
1362 -- if A (A1, A2) /= B (B1, B2) then
1366 -- exit when A2 = A'last (2);
1367 -- A2 := Index_T2'succ (A2);
1368 -- B2 := Index_T2'succ (B2);
1372 -- exit when A1 = A'last (1);
1373 -- A1 := Index_T1'succ (A1);
1374 -- B1 := Index_T1'succ (B1);
1381 -- Note on the formal types used (atyp and btyp). If either of the arrays
1382 -- is of a private type, we use the underlying type, and do an unchecked
1383 -- conversion of the actual. If either of the arrays has a bound depending
1384 -- on a discriminant, then we use the base type since otherwise we have an
1385 -- escaped discriminant in the function.
1387 -- If both arrays are constrained and have the same bounds, we can generate
1388 -- a loop with an explicit iteration scheme using a 'Range attribute over
1391 function Expand_Array_Equality
1396 Typ : Entity_Id) return Node_Id
1398 Loc : constant Source_Ptr := Sloc (Nod);
1399 Decls : constant List_Id := New_List;
1400 Index_List1 : constant List_Id := New_List;
1401 Index_List2 : constant List_Id := New_List;
1405 Func_Name : Entity_Id;
1406 Func_Body : Node_Id;
1408 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
1409 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
1413 -- The parameter types to be used for the formals
1418 Num : Int) return Node_Id;
1419 -- This builds the attribute reference Arr'Nam (Expr)
1421 function Component_Equality (Typ : Entity_Id) return Node_Id;
1422 -- Create one statement to compare corresponding components, designated
1423 -- by a full set of indices.
1425 function Get_Arg_Type (N : Node_Id) return Entity_Id;
1426 -- Given one of the arguments, computes the appropriate type to be used
1427 -- for that argument in the corresponding function formal
1429 function Handle_One_Dimension
1431 Index : Node_Id) return Node_Id;
1432 -- This procedure returns the following code
1435 -- Bn : Index_T := B'First (N);
1439 -- exit when An = A'Last (N);
1440 -- An := Index_T'Succ (An)
1441 -- Bn := Index_T'Succ (Bn)
1445 -- If both indices are constrained and identical, the procedure
1446 -- returns a simpler loop:
1448 -- for An in A'Range (N) loop
1452 -- N is the dimension for which we are generating a loop. Index is the
1453 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1454 -- xxx statement is either the loop or declare for the next dimension
1455 -- or if this is the last dimension the comparison of corresponding
1456 -- components of the arrays.
1458 -- The actual way the code works is to return the comparison of
1459 -- corresponding components for the N+1 call. That's neater!
1461 function Test_Empty_Arrays return Node_Id;
1462 -- This function constructs the test for both arrays being empty
1463 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1465 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1467 function Test_Lengths_Correspond return Node_Id;
1468 -- This function constructs the test for arrays having different lengths
1469 -- in at least one index position, in which case the resulting code is:
1471 -- A'length (1) /= B'length (1)
1473 -- A'length (2) /= B'length (2)
1484 Num : Int) return Node_Id
1488 Make_Attribute_Reference (Loc,
1489 Attribute_Name => Nam,
1490 Prefix => New_Reference_To (Arr, Loc),
1491 Expressions => New_List (Make_Integer_Literal (Loc, Num)));
1494 ------------------------
1495 -- Component_Equality --
1496 ------------------------
1498 function Component_Equality (Typ : Entity_Id) return Node_Id is
1503 -- if a(i1...) /= b(j1...) then return false; end if;
1506 Make_Indexed_Component (Loc,
1507 Prefix => Make_Identifier (Loc, Chars (A)),
1508 Expressions => Index_List1);
1511 Make_Indexed_Component (Loc,
1512 Prefix => Make_Identifier (Loc, Chars (B)),
1513 Expressions => Index_List2);
1515 Test := Expand_Composite_Equality
1516 (Nod, Component_Type (Typ), L, R, Decls);
1518 -- If some (sub)component is an unchecked_union, the whole operation
1519 -- will raise program error.
1521 if Nkind (Test) = N_Raise_Program_Error then
1523 -- This node is going to be inserted at a location where a
1524 -- statement is expected: clear its Etype so analysis will set
1525 -- it to the expected Standard_Void_Type.
1527 Set_Etype (Test, Empty);
1532 Make_Implicit_If_Statement (Nod,
1533 Condition => Make_Op_Not (Loc, Right_Opnd => Test),
1534 Then_Statements => New_List (
1535 Make_Simple_Return_Statement (Loc,
1536 Expression => New_Occurrence_Of (Standard_False, Loc))));
1538 end Component_Equality;
1544 function Get_Arg_Type (N : Node_Id) return Entity_Id is
1555 T := Underlying_Type (T);
1557 X := First_Index (T);
1558 while Present (X) loop
1559 if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
1561 Denotes_Discriminant (Type_High_Bound (Etype (X)))
1574 --------------------------
1575 -- Handle_One_Dimension --
1576 ---------------------------
1578 function Handle_One_Dimension
1580 Index : Node_Id) return Node_Id
1582 Need_Separate_Indexes : constant Boolean :=
1584 or else not Is_Constrained (Ltyp);
1585 -- If the index types are identical, and we are working with
1586 -- constrained types, then we can use the same index for both
1589 An : constant Entity_Id := Make_Temporary (Loc, 'A');
1592 Index_T : Entity_Id;
1597 if N > Number_Dimensions (Ltyp) then
1598 return Component_Equality (Ltyp);
1601 -- Case where we generate a loop
1603 Index_T := Base_Type (Etype (Index));
1605 if Need_Separate_Indexes then
1606 Bn := Make_Temporary (Loc, 'B');
1611 Append (New_Reference_To (An, Loc), Index_List1);
1612 Append (New_Reference_To (Bn, Loc), Index_List2);
1614 Stm_List := New_List (
1615 Handle_One_Dimension (N + 1, Next_Index (Index)));
1617 if Need_Separate_Indexes then
1619 -- Generate guard for loop, followed by increments of indices
1621 Append_To (Stm_List,
1622 Make_Exit_Statement (Loc,
1625 Left_Opnd => New_Reference_To (An, Loc),
1626 Right_Opnd => Arr_Attr (A, Name_Last, N))));
1628 Append_To (Stm_List,
1629 Make_Assignment_Statement (Loc,
1630 Name => New_Reference_To (An, Loc),
1632 Make_Attribute_Reference (Loc,
1633 Prefix => New_Reference_To (Index_T, Loc),
1634 Attribute_Name => Name_Succ,
1635 Expressions => New_List (New_Reference_To (An, Loc)))));
1637 Append_To (Stm_List,
1638 Make_Assignment_Statement (Loc,
1639 Name => New_Reference_To (Bn, Loc),
1641 Make_Attribute_Reference (Loc,
1642 Prefix => New_Reference_To (Index_T, Loc),
1643 Attribute_Name => Name_Succ,
1644 Expressions => New_List (New_Reference_To (Bn, Loc)))));
1647 -- If separate indexes, we need a declare block for An and Bn, and a
1648 -- loop without an iteration scheme.
1650 if Need_Separate_Indexes then
1652 Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
1655 Make_Block_Statement (Loc,
1656 Declarations => New_List (
1657 Make_Object_Declaration (Loc,
1658 Defining_Identifier => An,
1659 Object_Definition => New_Reference_To (Index_T, Loc),
1660 Expression => Arr_Attr (A, Name_First, N)),
1662 Make_Object_Declaration (Loc,
1663 Defining_Identifier => Bn,
1664 Object_Definition => New_Reference_To (Index_T, Loc),
1665 Expression => Arr_Attr (B, Name_First, N))),
1667 Handled_Statement_Sequence =>
1668 Make_Handled_Sequence_Of_Statements (Loc,
1669 Statements => New_List (Loop_Stm)));
1671 -- If no separate indexes, return loop statement with explicit
1672 -- iteration scheme on its own
1676 Make_Implicit_Loop_Statement (Nod,
1677 Statements => Stm_List,
1679 Make_Iteration_Scheme (Loc,
1680 Loop_Parameter_Specification =>
1681 Make_Loop_Parameter_Specification (Loc,
1682 Defining_Identifier => An,
1683 Discrete_Subtype_Definition =>
1684 Arr_Attr (A, Name_Range, N))));
1687 end Handle_One_Dimension;
1689 -----------------------
1690 -- Test_Empty_Arrays --
1691 -----------------------
1693 function Test_Empty_Arrays return Node_Id is
1703 for J in 1 .. Number_Dimensions (Ltyp) loop
1706 Left_Opnd => Arr_Attr (A, Name_Length, J),
1707 Right_Opnd => Make_Integer_Literal (Loc, 0));
1711 Left_Opnd => Arr_Attr (B, Name_Length, J),
1712 Right_Opnd => Make_Integer_Literal (Loc, 0));
1721 Left_Opnd => Relocate_Node (Alist),
1722 Right_Opnd => Atest);
1726 Left_Opnd => Relocate_Node (Blist),
1727 Right_Opnd => Btest);
1734 Right_Opnd => Blist);
1735 end Test_Empty_Arrays;
1737 -----------------------------
1738 -- Test_Lengths_Correspond --
1739 -----------------------------
1741 function Test_Lengths_Correspond return Node_Id is
1747 for J in 1 .. Number_Dimensions (Ltyp) loop
1750 Left_Opnd => Arr_Attr (A, Name_Length, J),
1751 Right_Opnd => Arr_Attr (B, Name_Length, J));
1758 Left_Opnd => Relocate_Node (Result),
1759 Right_Opnd => Rtest);
1764 end Test_Lengths_Correspond;
1766 -- Start of processing for Expand_Array_Equality
1769 Ltyp := Get_Arg_Type (Lhs);
1770 Rtyp := Get_Arg_Type (Rhs);
1772 -- For now, if the argument types are not the same, go to the base type,
1773 -- since the code assumes that the formals have the same type. This is
1774 -- fixable in future ???
1776 if Ltyp /= Rtyp then
1777 Ltyp := Base_Type (Ltyp);
1778 Rtyp := Base_Type (Rtyp);
1779 pragma Assert (Ltyp = Rtyp);
1782 -- Build list of formals for function
1784 Formals := New_List (
1785 Make_Parameter_Specification (Loc,
1786 Defining_Identifier => A,
1787 Parameter_Type => New_Reference_To (Ltyp, Loc)),
1789 Make_Parameter_Specification (Loc,
1790 Defining_Identifier => B,
1791 Parameter_Type => New_Reference_To (Rtyp, Loc)));
1793 Func_Name := Make_Temporary (Loc, 'E');
1795 -- Build statement sequence for function
1798 Make_Subprogram_Body (Loc,
1800 Make_Function_Specification (Loc,
1801 Defining_Unit_Name => Func_Name,
1802 Parameter_Specifications => Formals,
1803 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
1805 Declarations => Decls,
1807 Handled_Statement_Sequence =>
1808 Make_Handled_Sequence_Of_Statements (Loc,
1809 Statements => New_List (
1811 Make_Implicit_If_Statement (Nod,
1812 Condition => Test_Empty_Arrays,
1813 Then_Statements => New_List (
1814 Make_Simple_Return_Statement (Loc,
1816 New_Occurrence_Of (Standard_True, Loc)))),
1818 Make_Implicit_If_Statement (Nod,
1819 Condition => Test_Lengths_Correspond,
1820 Then_Statements => New_List (
1821 Make_Simple_Return_Statement (Loc,
1823 New_Occurrence_Of (Standard_False, Loc)))),
1825 Handle_One_Dimension (1, First_Index (Ltyp)),
1827 Make_Simple_Return_Statement (Loc,
1828 Expression => New_Occurrence_Of (Standard_True, Loc)))));
1830 Set_Has_Completion (Func_Name, True);
1831 Set_Is_Inlined (Func_Name);
1833 -- If the array type is distinct from the type of the arguments, it
1834 -- is the full view of a private type. Apply an unchecked conversion
1835 -- to insure that analysis of the call succeeds.
1845 or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
1847 L := OK_Convert_To (Ltyp, Lhs);
1851 or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
1853 R := OK_Convert_To (Rtyp, Rhs);
1856 Actuals := New_List (L, R);
1859 Append_To (Bodies, Func_Body);
1862 Make_Function_Call (Loc,
1863 Name => New_Reference_To (Func_Name, Loc),
1864 Parameter_Associations => Actuals);
1865 end Expand_Array_Equality;
1867 -----------------------------
1868 -- Expand_Boolean_Operator --
1869 -----------------------------
1871 -- Note that we first get the actual subtypes of the operands, since we
1872 -- always want to deal with types that have bounds.
1874 procedure Expand_Boolean_Operator (N : Node_Id) is
1875 Typ : constant Entity_Id := Etype (N);
1878 -- Special case of bit packed array where both operands are known to be
1879 -- properly aligned. In this case we use an efficient run time routine
1880 -- to carry out the operation (see System.Bit_Ops).
1882 if Is_Bit_Packed_Array (Typ)
1883 and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
1884 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
1886 Expand_Packed_Boolean_Operator (N);
1890 -- For the normal non-packed case, the general expansion is to build
1891 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
1892 -- and then inserting it into the tree. The original operator node is
1893 -- then rewritten as a call to this function. We also use this in the
1894 -- packed case if either operand is a possibly unaligned object.
1897 Loc : constant Source_Ptr := Sloc (N);
1898 L : constant Node_Id := Relocate_Node (Left_Opnd (N));
1899 R : constant Node_Id := Relocate_Node (Right_Opnd (N));
1900 Func_Body : Node_Id;
1901 Func_Name : Entity_Id;
1904 Convert_To_Actual_Subtype (L);
1905 Convert_To_Actual_Subtype (R);
1906 Ensure_Defined (Etype (L), N);
1907 Ensure_Defined (Etype (R), N);
1908 Apply_Length_Check (R, Etype (L));
1910 if Nkind (N) = N_Op_Xor then
1911 Silly_Boolean_Array_Xor_Test (N, Etype (L));
1914 if Nkind (Parent (N)) = N_Assignment_Statement
1915 and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
1917 Build_Boolean_Array_Proc_Call (Parent (N), L, R);
1919 elsif Nkind (Parent (N)) = N_Op_Not
1920 and then Nkind (N) = N_Op_And
1922 Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
1927 Func_Body := Make_Boolean_Array_Op (Etype (L), N);
1928 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1929 Insert_Action (N, Func_Body);
1931 -- Now rewrite the expression with a call
1934 Make_Function_Call (Loc,
1935 Name => New_Reference_To (Func_Name, Loc),
1936 Parameter_Associations =>
1939 Make_Type_Conversion
1940 (Loc, New_Reference_To (Etype (L), Loc), R))));
1942 Analyze_And_Resolve (N, Typ);
1945 end Expand_Boolean_Operator;
1947 -------------------------------
1948 -- Expand_Composite_Equality --
1949 -------------------------------
1951 -- This function is only called for comparing internal fields of composite
1952 -- types when these fields are themselves composites. This is a special
1953 -- case because it is not possible to respect normal Ada visibility rules.
1955 function Expand_Composite_Equality
1960 Bodies : List_Id) return Node_Id
1962 Loc : constant Source_Ptr := Sloc (Nod);
1963 Full_Type : Entity_Id;
1968 if Is_Private_Type (Typ) then
1969 Full_Type := Underlying_Type (Typ);
1974 -- Defense against malformed private types with no completion the error
1975 -- will be diagnosed later by check_completion
1977 if No (Full_Type) then
1978 return New_Reference_To (Standard_False, Loc);
1981 Full_Type := Base_Type (Full_Type);
1983 if Is_Array_Type (Full_Type) then
1985 -- If the operand is an elementary type other than a floating-point
1986 -- type, then we can simply use the built-in block bitwise equality,
1987 -- since the predefined equality operators always apply and bitwise
1988 -- equality is fine for all these cases.
1990 if Is_Elementary_Type (Component_Type (Full_Type))
1991 and then not Is_Floating_Point_Type (Component_Type (Full_Type))
1993 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
1995 -- For composite component types, and floating-point types, use the
1996 -- expansion. This deals with tagged component types (where we use
1997 -- the applicable equality routine) and floating-point, (where we
1998 -- need to worry about negative zeroes), and also the case of any
1999 -- composite type recursively containing such fields.
2002 return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
2005 elsif Is_Tagged_Type (Full_Type) then
2007 -- Call the primitive operation "=" of this type
2009 if Is_Class_Wide_Type (Full_Type) then
2010 Full_Type := Root_Type (Full_Type);
2013 -- If this is derived from an untagged private type completed with a
2014 -- tagged type, it does not have a full view, so we use the primitive
2015 -- operations of the private type. This check should no longer be
2016 -- necessary when these types receive their full views ???
2018 if Is_Private_Type (Typ)
2019 and then not Is_Tagged_Type (Typ)
2020 and then not Is_Controlled (Typ)
2021 and then Is_Derived_Type (Typ)
2022 and then No (Full_View (Typ))
2024 Prim := First_Elmt (Collect_Primitive_Operations (Typ));
2026 Prim := First_Elmt (Primitive_Operations (Full_Type));
2030 Eq_Op := Node (Prim);
2031 exit when Chars (Eq_Op) = Name_Op_Eq
2032 and then Etype (First_Formal (Eq_Op)) =
2033 Etype (Next_Formal (First_Formal (Eq_Op)))
2034 and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
2036 pragma Assert (Present (Prim));
2039 Eq_Op := Node (Prim);
2042 Make_Function_Call (Loc,
2043 Name => New_Reference_To (Eq_Op, Loc),
2044 Parameter_Associations =>
2046 (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
2047 Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
2049 elsif Is_Record_Type (Full_Type) then
2050 Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
2052 if Present (Eq_Op) then
2053 if Etype (First_Formal (Eq_Op)) /= Full_Type then
2055 -- Inherited equality from parent type. Convert the actuals to
2056 -- match signature of operation.
2059 T : constant Entity_Id := Etype (First_Formal (Eq_Op));
2063 Make_Function_Call (Loc,
2064 Name => New_Reference_To (Eq_Op, Loc),
2065 Parameter_Associations =>
2066 New_List (OK_Convert_To (T, Lhs),
2067 OK_Convert_To (T, Rhs)));
2071 -- Comparison between Unchecked_Union components
2073 if Is_Unchecked_Union (Full_Type) then
2075 Lhs_Type : Node_Id := Full_Type;
2076 Rhs_Type : Node_Id := Full_Type;
2077 Lhs_Discr_Val : Node_Id;
2078 Rhs_Discr_Val : Node_Id;
2083 if Nkind (Lhs) = N_Selected_Component then
2084 Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
2089 if Nkind (Rhs) = N_Selected_Component then
2090 Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
2093 -- Lhs of the composite equality
2095 if Is_Constrained (Lhs_Type) then
2097 -- Since the enclosing record type can never be an
2098 -- Unchecked_Union (this code is executed for records
2099 -- that do not have variants), we may reference its
2102 if Nkind (Lhs) = N_Selected_Component
2103 and then Has_Per_Object_Constraint (
2104 Entity (Selector_Name (Lhs)))
2107 Make_Selected_Component (Loc,
2108 Prefix => Prefix (Lhs),
2111 Get_Discriminant_Value (
2112 First_Discriminant (Lhs_Type),
2114 Stored_Constraint (Lhs_Type))));
2117 Lhs_Discr_Val := New_Copy (
2118 Get_Discriminant_Value (
2119 First_Discriminant (Lhs_Type),
2121 Stored_Constraint (Lhs_Type)));
2125 -- It is not possible to infer the discriminant since
2126 -- the subtype is not constrained.
2129 Make_Raise_Program_Error (Loc,
2130 Reason => PE_Unchecked_Union_Restriction);
2133 -- Rhs of the composite equality
2135 if Is_Constrained (Rhs_Type) then
2136 if Nkind (Rhs) = N_Selected_Component
2137 and then Has_Per_Object_Constraint (
2138 Entity (Selector_Name (Rhs)))
2141 Make_Selected_Component (Loc,
2142 Prefix => Prefix (Rhs),
2145 Get_Discriminant_Value (
2146 First_Discriminant (Rhs_Type),
2148 Stored_Constraint (Rhs_Type))));
2151 Rhs_Discr_Val := New_Copy (
2152 Get_Discriminant_Value (
2153 First_Discriminant (Rhs_Type),
2155 Stored_Constraint (Rhs_Type)));
2160 Make_Raise_Program_Error (Loc,
2161 Reason => PE_Unchecked_Union_Restriction);
2164 -- Call the TSS equality function with the inferred
2165 -- discriminant values.
2168 Make_Function_Call (Loc,
2169 Name => New_Reference_To (Eq_Op, Loc),
2170 Parameter_Associations => New_List (
2179 Make_Function_Call (Loc,
2180 Name => New_Reference_To (Eq_Op, Loc),
2181 Parameter_Associations => New_List (Lhs, Rhs));
2185 elsif Ada_Version >= Ada_2012 then
2187 -- if no TSS has been created for the type, check whether there is
2188 -- a primitive equality declared for it. If it is abstract replace
2189 -- the call with an explicit raise (AI05-0123).
2195 Prim := First_Elmt (Collect_Primitive_Operations (Full_Type));
2196 while Present (Prim) loop
2198 -- Locate primitive equality with the right signature
2200 if Chars (Node (Prim)) = Name_Op_Eq
2201 and then Etype (First_Formal (Node (Prim))) =
2202 Etype (Next_Formal (First_Formal (Node (Prim))))
2203 and then Etype (Node (Prim)) = Standard_Boolean
2205 if Is_Abstract_Subprogram (Node (Prim)) then
2207 Make_Raise_Program_Error (Loc,
2208 Reason => PE_Explicit_Raise);
2211 Make_Function_Call (Loc,
2212 Name => New_Reference_To (Node (Prim), Loc),
2213 Parameter_Associations => New_List (Lhs, Rhs));
2221 -- Use predefined equality iff no user-defined primitive exists
2223 return Make_Op_Eq (Loc, Lhs, Rhs);
2226 return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
2230 -- If not array or record type, it is predefined equality.
2232 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2234 end Expand_Composite_Equality;
2236 ------------------------
2237 -- Expand_Concatenate --
2238 ------------------------
2240 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
2241 Loc : constant Source_Ptr := Sloc (Cnode);
2243 Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
2244 -- Result type of concatenation
2246 Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
2247 -- Component type. Elements of this component type can appear as one
2248 -- of the operands of concatenation as well as arrays.
2250 Istyp : constant Entity_Id := Etype (First_Index (Atyp));
2253 Ityp : constant Entity_Id := Base_Type (Istyp);
2254 -- Index type. This is the base type of the index subtype, and is used
2255 -- for all computed bounds (which may be out of range of Istyp in the
2256 -- case of null ranges).
2259 -- This is the type we use to do arithmetic to compute the bounds and
2260 -- lengths of operands. The choice of this type is a little subtle and
2261 -- is discussed in a separate section at the start of the body code.
2263 Concatenation_Error : exception;
2264 -- Raised if concatenation is sure to raise a CE
2266 Result_May_Be_Null : Boolean := True;
2267 -- Reset to False if at least one operand is encountered which is known
2268 -- at compile time to be non-null. Used for handling the special case
2269 -- of setting the high bound to the last operand high bound for a null
2270 -- result, thus ensuring a proper high bound in the super-flat case.
2272 N : constant Nat := List_Length (Opnds);
2273 -- Number of concatenation operands including possibly null operands
2276 -- Number of operands excluding any known to be null, except that the
2277 -- last operand is always retained, in case it provides the bounds for
2281 -- Current operand being processed in the loop through operands. After
2282 -- this loop is complete, always contains the last operand (which is not
2283 -- the same as Operands (NN), since null operands are skipped).
2285 -- Arrays describing the operands, only the first NN entries of each
2286 -- array are set (NN < N when we exclude known null operands).
2288 Is_Fixed_Length : array (1 .. N) of Boolean;
2289 -- True if length of corresponding operand known at compile time
2291 Operands : array (1 .. N) of Node_Id;
2292 -- Set to the corresponding entry in the Opnds list (but note that null
2293 -- operands are excluded, so not all entries in the list are stored).
2295 Fixed_Length : array (1 .. N) of Uint;
2296 -- Set to length of operand. Entries in this array are set only if the
2297 -- corresponding entry in Is_Fixed_Length is True.
2299 Opnd_Low_Bound : array (1 .. N) of Node_Id;
2300 -- Set to lower bound of operand. Either an integer literal in the case
2301 -- where the bound is known at compile time, else actual lower bound.
2302 -- The operand low bound is of type Ityp.
2304 Var_Length : array (1 .. N) of Entity_Id;
2305 -- Set to an entity of type Natural that contains the length of an
2306 -- operand whose length is not known at compile time. Entries in this
2307 -- array are set only if the corresponding entry in Is_Fixed_Length
2308 -- is False. The entity is of type Artyp.
2310 Aggr_Length : array (0 .. N) of Node_Id;
2311 -- The J'th entry in an expression node that represents the total length
2312 -- of operands 1 through J. It is either an integer literal node, or a
2313 -- reference to a constant entity with the right value, so it is fine
2314 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2315 -- entry always is set to zero. The length is of type Artyp.
2317 Low_Bound : Node_Id;
2318 -- A tree node representing the low bound of the result (of type Ityp).
2319 -- This is either an integer literal node, or an identifier reference to
2320 -- a constant entity initialized to the appropriate value.
2322 Last_Opnd_High_Bound : Node_Id;
2323 -- A tree node representing the high bound of the last operand. This
2324 -- need only be set if the result could be null. It is used for the
2325 -- special case of setting the right high bound for a null result.
2326 -- This is of type Ityp.
2328 High_Bound : Node_Id;
2329 -- A tree node representing the high bound of the result (of type Ityp)
2332 -- Result of the concatenation (of type Ityp)
2334 Actions : constant List_Id := New_List;
2335 -- Collect actions to be inserted if Save_Space is False
2337 Save_Space : Boolean;
2338 pragma Warnings (Off, Save_Space);
2339 -- Set to True if we are saving generated code space by calling routines
2340 -- in packages System.Concat_n.
2342 Known_Non_Null_Operand_Seen : Boolean;
2343 -- Set True during generation of the assignements of operands into
2344 -- result once an operand known to be non-null has been seen.
2346 function Make_Artyp_Literal (Val : Nat) return Node_Id;
2347 -- This function makes an N_Integer_Literal node that is returned in
2348 -- analyzed form with the type set to Artyp. Importantly this literal
2349 -- is not flagged as static, so that if we do computations with it that
2350 -- result in statically detected out of range conditions, we will not
2351 -- generate error messages but instead warning messages.
2353 function To_Artyp (X : Node_Id) return Node_Id;
2354 -- Given a node of type Ityp, returns the corresponding value of type
2355 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2356 -- For enum types, the Pos of the value is returned.
2358 function To_Ityp (X : Node_Id) return Node_Id;
2359 -- The inverse function (uses Val in the case of enumeration types)
2361 ------------------------
2362 -- Make_Artyp_Literal --
2363 ------------------------
2365 function Make_Artyp_Literal (Val : Nat) return Node_Id is
2366 Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
2368 Set_Etype (Result, Artyp);
2369 Set_Analyzed (Result, True);
2370 Set_Is_Static_Expression (Result, False);
2372 end Make_Artyp_Literal;
2378 function To_Artyp (X : Node_Id) return Node_Id is
2380 if Ityp = Base_Type (Artyp) then
2383 elsif Is_Enumeration_Type (Ityp) then
2385 Make_Attribute_Reference (Loc,
2386 Prefix => New_Occurrence_Of (Ityp, Loc),
2387 Attribute_Name => Name_Pos,
2388 Expressions => New_List (X));
2391 return Convert_To (Artyp, X);
2399 function To_Ityp (X : Node_Id) return Node_Id is
2401 if Is_Enumeration_Type (Ityp) then
2403 Make_Attribute_Reference (Loc,
2404 Prefix => New_Occurrence_Of (Ityp, Loc),
2405 Attribute_Name => Name_Val,
2406 Expressions => New_List (X));
2408 -- Case where we will do a type conversion
2411 if Ityp = Base_Type (Artyp) then
2414 return Convert_To (Ityp, X);
2419 -- Local Declarations
2421 Opnd_Typ : Entity_Id;
2429 -- Choose an appropriate computational type
2431 -- We will be doing calculations of lengths and bounds in this routine
2432 -- and computing one from the other in some cases, e.g. getting the high
2433 -- bound by adding the length-1 to the low bound.
2435 -- We can't just use the index type, or even its base type for this
2436 -- purpose for two reasons. First it might be an enumeration type which
2437 -- is not suitable fo computations of any kind, and second it may simply
2438 -- not have enough range. For example if the index type is -128..+127
2439 -- then lengths can be up to 256, which is out of range of the type.
2441 -- For enumeration types, we can simply use Standard_Integer, this is
2442 -- sufficient since the actual number of enumeration literals cannot
2443 -- possibly exceed the range of integer (remember we will be doing the
2444 -- arithmetic with POS values, not representation values).
2446 if Is_Enumeration_Type (Ityp) then
2447 Artyp := Standard_Integer;
2449 -- If index type is Positive, we use the standard unsigned type, to give
2450 -- more room on the top of the range, obviating the need for an overflow
2451 -- check when creating the upper bound. This is needed to avoid junk
2452 -- overflow checks in the common case of String types.
2454 -- ??? Disabled for now
2456 -- elsif Istyp = Standard_Positive then
2457 -- Artyp := Standard_Unsigned;
2459 -- For modular types, we use a 32-bit modular type for types whose size
2460 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2461 -- identity type, and for larger unsigned types we use 64-bits.
2463 elsif Is_Modular_Integer_Type (Ityp) then
2464 if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
2465 Artyp := Standard_Unsigned;
2466 elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
2469 Artyp := RTE (RE_Long_Long_Unsigned);
2472 -- Similar treatment for signed types
2475 if RM_Size (Ityp) < RM_Size (Standard_Integer) then
2476 Artyp := Standard_Integer;
2477 elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
2480 Artyp := Standard_Long_Long_Integer;
2484 -- Supply dummy entry at start of length array
2486 Aggr_Length (0) := Make_Artyp_Literal (0);
2488 -- Go through operands setting up the above arrays
2492 Opnd := Remove_Head (Opnds);
2493 Opnd_Typ := Etype (Opnd);
2495 -- The parent got messed up when we put the operands in a list,
2496 -- so now put back the proper parent for the saved operand.
2498 Set_Parent (Opnd, Parent (Cnode));
2500 -- Set will be True when we have setup one entry in the array
2504 -- Singleton element (or character literal) case
2506 if Base_Type (Opnd_Typ) = Ctyp then
2508 Operands (NN) := Opnd;
2509 Is_Fixed_Length (NN) := True;
2510 Fixed_Length (NN) := Uint_1;
2511 Result_May_Be_Null := False;
2513 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2514 -- since we know that the result cannot be null).
2516 Opnd_Low_Bound (NN) :=
2517 Make_Attribute_Reference (Loc,
2518 Prefix => New_Reference_To (Istyp, Loc),
2519 Attribute_Name => Name_First);
2523 -- String literal case (can only occur for strings of course)
2525 elsif Nkind (Opnd) = N_String_Literal then
2526 Len := String_Literal_Length (Opnd_Typ);
2529 Result_May_Be_Null := False;
2532 -- Capture last operand high bound if result could be null
2534 if J = N and then Result_May_Be_Null then
2535 Last_Opnd_High_Bound :=
2538 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
2539 Right_Opnd => Make_Integer_Literal (Loc, 1));
2542 -- Skip null string literal
2544 if J < N and then Len = 0 then
2549 Operands (NN) := Opnd;
2550 Is_Fixed_Length (NN) := True;
2552 -- Set length and bounds
2554 Fixed_Length (NN) := Len;
2556 Opnd_Low_Bound (NN) :=
2557 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
2564 -- Check constrained case with known bounds
2566 if Is_Constrained (Opnd_Typ) then
2568 Index : constant Node_Id := First_Index (Opnd_Typ);
2569 Indx_Typ : constant Entity_Id := Etype (Index);
2570 Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
2571 Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
2574 -- Fixed length constrained array type with known at compile
2575 -- time bounds is last case of fixed length operand.
2577 if Compile_Time_Known_Value (Lo)
2579 Compile_Time_Known_Value (Hi)
2582 Loval : constant Uint := Expr_Value (Lo);
2583 Hival : constant Uint := Expr_Value (Hi);
2584 Len : constant Uint :=
2585 UI_Max (Hival - Loval + 1, Uint_0);
2589 Result_May_Be_Null := False;
2592 -- Capture last operand bound if result could be null
2594 if J = N and then Result_May_Be_Null then
2595 Last_Opnd_High_Bound :=
2597 Make_Integer_Literal (Loc,
2598 Intval => Expr_Value (Hi)));
2601 -- Exclude null length case unless last operand
2603 if J < N and then Len = 0 then
2608 Operands (NN) := Opnd;
2609 Is_Fixed_Length (NN) := True;
2610 Fixed_Length (NN) := Len;
2612 Opnd_Low_Bound (NN) := To_Ityp (
2613 Make_Integer_Literal (Loc,
2614 Intval => Expr_Value (Lo)));
2622 -- All cases where the length is not known at compile time, or the
2623 -- special case of an operand which is known to be null but has a
2624 -- lower bound other than 1 or is other than a string type.
2629 -- Capture operand bounds
2631 Opnd_Low_Bound (NN) :=
2632 Make_Attribute_Reference (Loc,
2634 Duplicate_Subexpr (Opnd, Name_Req => True),
2635 Attribute_Name => Name_First);
2637 if J = N and Result_May_Be_Null then
2638 Last_Opnd_High_Bound :=
2640 Make_Attribute_Reference (Loc,
2642 Duplicate_Subexpr (Opnd, Name_Req => True),
2643 Attribute_Name => Name_Last));
2646 -- Capture length of operand in entity
2648 Operands (NN) := Opnd;
2649 Is_Fixed_Length (NN) := False;
2651 Var_Length (NN) := Make_Temporary (Loc, 'L');
2654 Make_Object_Declaration (Loc,
2655 Defining_Identifier => Var_Length (NN),
2656 Constant_Present => True,
2658 Object_Definition =>
2659 New_Occurrence_Of (Artyp, Loc),
2662 Make_Attribute_Reference (Loc,
2664 Duplicate_Subexpr (Opnd, Name_Req => True),
2665 Attribute_Name => Name_Length)));
2669 -- Set next entry in aggregate length array
2671 -- For first entry, make either integer literal for fixed length
2672 -- or a reference to the saved length for variable length.
2675 if Is_Fixed_Length (1) then
2677 Make_Integer_Literal (Loc,
2678 Intval => Fixed_Length (1));
2681 New_Reference_To (Var_Length (1), Loc);
2684 -- If entry is fixed length and only fixed lengths so far, make
2685 -- appropriate new integer literal adding new length.
2687 elsif Is_Fixed_Length (NN)
2688 and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
2691 Make_Integer_Literal (Loc,
2692 Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
2694 -- All other cases, construct an addition node for the length and
2695 -- create an entity initialized to this length.
2698 Ent := Make_Temporary (Loc, 'L');
2700 if Is_Fixed_Length (NN) then
2701 Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
2703 Clen := New_Reference_To (Var_Length (NN), Loc);
2707 Make_Object_Declaration (Loc,
2708 Defining_Identifier => Ent,
2709 Constant_Present => True,
2711 Object_Definition =>
2712 New_Occurrence_Of (Artyp, Loc),
2716 Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
2717 Right_Opnd => Clen)));
2719 Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
2726 -- If we have only skipped null operands, return the last operand
2733 -- If we have only one non-null operand, return it and we are done.
2734 -- There is one case in which this cannot be done, and that is when
2735 -- the sole operand is of the element type, in which case it must be
2736 -- converted to an array, and the easiest way of doing that is to go
2737 -- through the normal general circuit.
2740 and then Base_Type (Etype (Operands (1))) /= Ctyp
2742 Result := Operands (1);
2746 -- Cases where we have a real concatenation
2748 -- Next step is to find the low bound for the result array that we
2749 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
2751 -- If the ultimate ancestor of the index subtype is a constrained array
2752 -- definition, then the lower bound is that of the index subtype as
2753 -- specified by (RM 4.5.3(6)).
2755 -- The right test here is to go to the root type, and then the ultimate
2756 -- ancestor is the first subtype of this root type.
2758 if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
2760 Make_Attribute_Reference (Loc,
2762 New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
2763 Attribute_Name => Name_First);
2765 -- If the first operand in the list has known length we know that
2766 -- the lower bound of the result is the lower bound of this operand.
2768 elsif Is_Fixed_Length (1) then
2769 Low_Bound := Opnd_Low_Bound (1);
2771 -- OK, we don't know the lower bound, we have to build a horrible
2772 -- expression actions node of the form
2774 -- if Cond1'Length /= 0 then
2777 -- if Opnd2'Length /= 0 then
2782 -- The nesting ends either when we hit an operand whose length is known
2783 -- at compile time, or on reaching the last operand, whose low bound we
2784 -- take unconditionally whether or not it is null. It's easiest to do
2785 -- this with a recursive procedure:
2789 function Get_Known_Bound (J : Nat) return Node_Id;
2790 -- Returns the lower bound determined by operands J .. NN
2792 ---------------------
2793 -- Get_Known_Bound --
2794 ---------------------
2796 function Get_Known_Bound (J : Nat) return Node_Id is
2798 if Is_Fixed_Length (J) or else J = NN then
2799 return New_Copy (Opnd_Low_Bound (J));
2803 Make_Conditional_Expression (Loc,
2804 Expressions => New_List (
2807 Left_Opnd => New_Reference_To (Var_Length (J), Loc),
2808 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2810 New_Copy (Opnd_Low_Bound (J)),
2811 Get_Known_Bound (J + 1)));
2813 end Get_Known_Bound;
2816 Ent := Make_Temporary (Loc, 'L');
2819 Make_Object_Declaration (Loc,
2820 Defining_Identifier => Ent,
2821 Constant_Present => True,
2822 Object_Definition => New_Occurrence_Of (Ityp, Loc),
2823 Expression => Get_Known_Bound (1)));
2825 Low_Bound := New_Reference_To (Ent, Loc);
2829 -- Now we can safely compute the upper bound, normally
2830 -- Low_Bound + Length - 1.
2835 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2837 Make_Op_Subtract (Loc,
2838 Left_Opnd => New_Copy (Aggr_Length (NN)),
2839 Right_Opnd => Make_Artyp_Literal (1))));
2841 -- Note that calculation of the high bound may cause overflow in some
2842 -- very weird cases, so in the general case we need an overflow check on
2843 -- the high bound. We can avoid this for the common case of string types
2844 -- and other types whose index is Positive, since we chose a wider range
2845 -- for the arithmetic type.
2847 if Istyp /= Standard_Positive then
2848 Activate_Overflow_Check (High_Bound);
2851 -- Handle the exceptional case where the result is null, in which case
2852 -- case the bounds come from the last operand (so that we get the proper
2853 -- bounds if the last operand is super-flat).
2855 if Result_May_Be_Null then
2857 Make_Conditional_Expression (Loc,
2858 Expressions => New_List (
2860 Left_Opnd => New_Copy (Aggr_Length (NN)),
2861 Right_Opnd => Make_Artyp_Literal (0)),
2862 Last_Opnd_High_Bound,
2866 -- Here is where we insert the saved up actions
2868 Insert_Actions (Cnode, Actions, Suppress => All_Checks);
2870 -- Now we construct an array object with appropriate bounds. We mark
2871 -- the target as internal to prevent useless initialization when
2872 -- Initialize_Scalars is enabled.
2874 Ent := Make_Temporary (Loc, 'S');
2875 Set_Is_Internal (Ent);
2877 -- If the bound is statically known to be out of range, we do not want
2878 -- to abort, we want a warning and a runtime constraint error. Note that
2879 -- we have arranged that the result will not be treated as a static
2880 -- constant, so we won't get an illegality during this insertion.
2882 Insert_Action (Cnode,
2883 Make_Object_Declaration (Loc,
2884 Defining_Identifier => Ent,
2885 Object_Definition =>
2886 Make_Subtype_Indication (Loc,
2887 Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
2889 Make_Index_Or_Discriminant_Constraint (Loc,
2890 Constraints => New_List (
2892 Low_Bound => Low_Bound,
2893 High_Bound => High_Bound))))),
2894 Suppress => All_Checks);
2896 -- If the result of the concatenation appears as the initializing
2897 -- expression of an object declaration, we can just rename the
2898 -- result, rather than copying it.
2900 Set_OK_To_Rename (Ent);
2902 -- Catch the static out of range case now
2904 if Raises_Constraint_Error (High_Bound) then
2905 raise Concatenation_Error;
2908 -- Now we will generate the assignments to do the actual concatenation
2910 -- There is one case in which we will not do this, namely when all the
2911 -- following conditions are met:
2913 -- The result type is Standard.String
2915 -- There are nine or fewer retained (non-null) operands
2917 -- The optimization level is -O0
2919 -- The corresponding System.Concat_n.Str_Concat_n routine is
2920 -- available in the run time.
2922 -- The debug flag gnatd.c is not set
2924 -- If all these conditions are met then we generate a call to the
2925 -- relevant concatenation routine. The purpose of this is to avoid
2926 -- undesirable code bloat at -O0.
2928 if Atyp = Standard_String
2929 and then NN in 2 .. 9
2930 and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC)
2931 and then not Debug_Flag_Dot_C
2934 RR : constant array (Nat range 2 .. 9) of RE_Id :=
2945 if RTE_Available (RR (NN)) then
2947 Opnds : constant List_Id :=
2948 New_List (New_Occurrence_Of (Ent, Loc));
2951 for J in 1 .. NN loop
2952 if Is_List_Member (Operands (J)) then
2953 Remove (Operands (J));
2956 if Base_Type (Etype (Operands (J))) = Ctyp then
2958 Make_Aggregate (Loc,
2959 Component_Associations => New_List (
2960 Make_Component_Association (Loc,
2961 Choices => New_List (
2962 Make_Integer_Literal (Loc, 1)),
2963 Expression => Operands (J)))));
2966 Append_To (Opnds, Operands (J));
2970 Insert_Action (Cnode,
2971 Make_Procedure_Call_Statement (Loc,
2972 Name => New_Reference_To (RTE (RR (NN)), Loc),
2973 Parameter_Associations => Opnds));
2975 Result := New_Reference_To (Ent, Loc);
2982 -- Not special case so generate the assignments
2984 Known_Non_Null_Operand_Seen := False;
2986 for J in 1 .. NN loop
2988 Lo : constant Node_Id :=
2990 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2991 Right_Opnd => Aggr_Length (J - 1));
2993 Hi : constant Node_Id :=
2995 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2997 Make_Op_Subtract (Loc,
2998 Left_Opnd => Aggr_Length (J),
2999 Right_Opnd => Make_Artyp_Literal (1)));
3002 -- Singleton case, simple assignment
3004 if Base_Type (Etype (Operands (J))) = Ctyp then
3005 Known_Non_Null_Operand_Seen := True;
3006 Insert_Action (Cnode,
3007 Make_Assignment_Statement (Loc,
3009 Make_Indexed_Component (Loc,
3010 Prefix => New_Occurrence_Of (Ent, Loc),
3011 Expressions => New_List (To_Ityp (Lo))),
3012 Expression => Operands (J)),
3013 Suppress => All_Checks);
3015 -- Array case, slice assignment, skipped when argument is fixed
3016 -- length and known to be null.
3018 elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
3021 Make_Assignment_Statement (Loc,
3025 New_Occurrence_Of (Ent, Loc),
3028 Low_Bound => To_Ityp (Lo),
3029 High_Bound => To_Ityp (Hi))),
3030 Expression => Operands (J));
3032 if Is_Fixed_Length (J) then
3033 Known_Non_Null_Operand_Seen := True;
3035 elsif not Known_Non_Null_Operand_Seen then
3037 -- Here if operand length is not statically known and no
3038 -- operand known to be non-null has been processed yet.
3039 -- If operand length is 0, we do not need to perform the
3040 -- assignment, and we must avoid the evaluation of the
3041 -- high bound of the slice, since it may underflow if the
3042 -- low bound is Ityp'First.
3045 Make_Implicit_If_Statement (Cnode,
3049 New_Occurrence_Of (Var_Length (J), Loc),
3050 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3055 Insert_Action (Cnode, Assign, Suppress => All_Checks);
3061 -- Finally we build the result, which is a reference to the array object
3063 Result := New_Reference_To (Ent, Loc);
3066 Rewrite (Cnode, Result);
3067 Analyze_And_Resolve (Cnode, Atyp);
3070 when Concatenation_Error =>
3072 -- Kill warning generated for the declaration of the static out of
3073 -- range high bound, and instead generate a Constraint_Error with
3074 -- an appropriate specific message.
3076 Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
3077 Apply_Compile_Time_Constraint_Error
3079 Msg => "concatenation result upper bound out of range?",
3080 Reason => CE_Range_Check_Failed);
3081 -- Set_Etype (Cnode, Atyp);
3082 end Expand_Concatenate;
3084 ------------------------
3085 -- Expand_N_Allocator --
3086 ------------------------
3088 procedure Expand_N_Allocator (N : Node_Id) is
3089 PtrT : constant Entity_Id := Etype (N);
3090 Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT));
3091 Etyp : constant Entity_Id := Etype (Expression (N));
3092 Loc : constant Source_Ptr := Sloc (N);
3097 procedure Complete_Coextension_Finalization;
3098 -- Generate finalization calls for all nested coextensions of N. This
3099 -- routine may allocate list controllers if necessary.
3101 procedure Rewrite_Coextension (N : Node_Id);
3102 -- Static coextensions have the same lifetime as the entity they
3103 -- constrain. Such occurrences can be rewritten as aliased objects
3104 -- and their unrestricted access used instead of the coextension.
3106 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id;
3107 -- Given a constrained array type E, returns a node representing the
3108 -- code to compute the size in storage elements for the given type.
3109 -- This is done without using the attribute (which malfunctions for
3112 ---------------------------------------
3113 -- Complete_Coextension_Finalization --
3114 ---------------------------------------
3116 procedure Complete_Coextension_Finalization is
3118 Coext_Elmt : Elmt_Id;
3122 function Inside_A_Return_Statement (N : Node_Id) return Boolean;
3123 -- Determine whether node N is part of a return statement
3125 function Needs_Initialization_Call (N : Node_Id) return Boolean;
3126 -- Determine whether node N is a subtype indicator allocator which
3127 -- acts a coextension. Such coextensions need initialization.
3129 -------------------------------
3130 -- Inside_A_Return_Statement --
3131 -------------------------------
3133 function Inside_A_Return_Statement (N : Node_Id) return Boolean is
3138 while Present (P) loop
3140 (P, N_Extended_Return_Statement, N_Simple_Return_Statement)
3144 -- Stop the traversal when we reach a subprogram body
3146 elsif Nkind (P) = N_Subprogram_Body then
3154 end Inside_A_Return_Statement;
3156 -------------------------------
3157 -- Needs_Initialization_Call --
3158 -------------------------------
3160 function Needs_Initialization_Call (N : Node_Id) return Boolean is
3164 if Nkind (N) = N_Explicit_Dereference
3165 and then Nkind (Prefix (N)) = N_Identifier
3166 and then Nkind (Parent (Entity (Prefix (N)))) =
3167 N_Object_Declaration
3169 Obj_Decl := Parent (Entity (Prefix (N)));
3172 Present (Expression (Obj_Decl))
3173 and then Nkind (Expression (Obj_Decl)) = N_Allocator
3174 and then Nkind (Expression (Expression (Obj_Decl))) /=
3175 N_Qualified_Expression;
3179 end Needs_Initialization_Call;
3181 -- Start of processing for Complete_Coextension_Finalization
3184 -- When a coextension root is inside a return statement, we need to
3185 -- use the finalization chain of the function's scope. This does not
3186 -- apply for controlled named access types because in those cases we
3187 -- can use the finalization chain of the type itself.
3189 if Inside_A_Return_Statement (N)
3191 (Ekind (PtrT) = E_Anonymous_Access_Type
3193 (Ekind (PtrT) = E_Access_Type
3194 and then No (Associated_Final_Chain (PtrT))))
3198 Outer_S : Entity_Id;
3203 while Present (S) and then S /= Standard_Standard loop
3204 if Ekind (S) = E_Function then
3205 Outer_S := Scope (S);
3207 -- Retrieve the declaration of the body
3212 (Corresponding_Body (Parent (Parent (S)))));
3219 -- Push the scope of the function body since we are inserting
3220 -- the list before the body, but we are currently in the body
3221 -- itself. Override the finalization list of PtrT since the
3222 -- finalization context is now different.
3224 Push_Scope (Outer_S);
3225 Build_Final_List (Decl, PtrT);
3229 -- The root allocator may not be controlled, but it still needs a
3230 -- finalization list for all nested coextensions.
3232 elsif No (Associated_Final_Chain (PtrT)) then
3233 Build_Final_List (N, PtrT);
3237 Make_Selected_Component (Loc,
3239 New_Reference_To (Associated_Final_Chain (PtrT), Loc),
3241 Make_Identifier (Loc, Name_F));
3243 Coext_Elmt := First_Elmt (Coextensions (N));
3244 while Present (Coext_Elmt) loop
3245 Coext := Node (Coext_Elmt);
3250 if Nkind (Coext) = N_Identifier then
3252 Make_Unchecked_Type_Conversion (Loc,
3253 Subtype_Mark => New_Reference_To (Etype (Coext), Loc),
3255 Make_Explicit_Dereference (Loc,
3256 Prefix => New_Copy_Tree (Coext)));
3258 Ref := New_Copy_Tree (Coext);
3261 -- No initialization call if not allowed
3263 Check_Restriction (No_Default_Initialization, N);
3265 if not Restriction_Active (No_Default_Initialization) then
3269 -- attach_to_final_list (Ref, Flist, 2)
3271 if Needs_Initialization_Call (Coext) then
3275 Typ => Etype (Coext),
3277 With_Attach => Make_Integer_Literal (Loc, Uint_2)));
3280 -- attach_to_final_list (Ref, Flist, 2)
3286 Flist_Ref => New_Copy_Tree (Flist),
3287 With_Attach => Make_Integer_Literal (Loc, Uint_2)));
3291 Next_Elmt (Coext_Elmt);
3293 end Complete_Coextension_Finalization;
3295 -------------------------
3296 -- Rewrite_Coextension --
3297 -------------------------
3299 procedure Rewrite_Coextension (N : Node_Id) is
3300 Temp : constant Node_Id := Make_Temporary (Loc, 'C');
3303 -- Cnn : aliased Etyp;
3305 Decl : constant Node_Id :=
3306 Make_Object_Declaration (Loc,
3307 Defining_Identifier => Temp,
3308 Aliased_Present => True,
3309 Object_Definition =>
3310 New_Occurrence_Of (Etyp, Loc));
3314 if Nkind (Expression (N)) = N_Qualified_Expression then
3315 Set_Expression (Decl, Expression (Expression (N)));
3318 -- Find the proper insertion node for the declaration
3321 while Present (Nod) loop
3322 exit when Nkind (Nod) in N_Statement_Other_Than_Procedure_Call
3323 or else Nkind (Nod) = N_Procedure_Call_Statement
3324 or else Nkind (Nod) in N_Declaration;
3325 Nod := Parent (Nod);
3328 Insert_Before (Nod, Decl);
3332 Make_Attribute_Reference (Loc,
3333 Prefix => New_Occurrence_Of (Temp, Loc),
3334 Attribute_Name => Name_Unrestricted_Access));
3336 Analyze_And_Resolve (N, PtrT);
3337 end Rewrite_Coextension;
3339 ------------------------------
3340 -- Size_In_Storage_Elements --
3341 ------------------------------
3343 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is
3345 -- Logically this just returns E'Max_Size_In_Storage_Elements.
3346 -- However, the reason for the existence of this function is
3347 -- to construct a test for sizes too large, which means near the
3348 -- 32-bit limit on a 32-bit machine, and precisely the trouble
3349 -- is that we get overflows when sizes are greater than 2**31.
3351 -- So what we end up doing for array types is to use the expression:
3353 -- number-of-elements * component_type'Max_Size_In_Storage_Elements
3355 -- which avoids this problem. All this is a bit bogus, but it does
3356 -- mean we catch common cases of trying to allocate arrays that
3357 -- are too large, and which in the absence of a check results in
3358 -- undetected chaos ???
3365 for J in 1 .. Number_Dimensions (E) loop
3367 Make_Attribute_Reference (Loc,
3368 Prefix => New_Occurrence_Of (E, Loc),
3369 Attribute_Name => Name_Length,
3370 Expressions => New_List (
3371 Make_Integer_Literal (Loc, J)));
3378 Make_Op_Multiply (Loc,
3385 Make_Op_Multiply (Loc,
3388 Make_Attribute_Reference (Loc,
3389 Prefix => New_Occurrence_Of (Component_Type (E), Loc),
3390 Attribute_Name => Name_Max_Size_In_Storage_Elements));
3392 end Size_In_Storage_Elements;
3394 -- Start of processing for Expand_N_Allocator
3397 -- RM E.2.3(22). We enforce that the expected type of an allocator
3398 -- shall not be a remote access-to-class-wide-limited-private type
3400 -- Why is this being done at expansion time, seems clearly wrong ???
3402 Validate_Remote_Access_To_Class_Wide_Type (N);
3404 -- Set the Storage Pool
3406 Set_Storage_Pool (N, Associated_Storage_Pool (Root_Type (PtrT)));
3408 if Present (Storage_Pool (N)) then
3409 if Is_RTE (Storage_Pool (N), RE_SS_Pool) then
3410 if VM_Target = No_VM then
3411 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3414 elsif Is_Class_Wide_Type (Etype (Storage_Pool (N))) then
3415 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3418 Set_Procedure_To_Call (N,
3419 Find_Prim_Op (Etype (Storage_Pool (N)), Name_Allocate));
3423 -- Under certain circumstances we can replace an allocator by an access
3424 -- to statically allocated storage. The conditions, as noted in AARM
3425 -- 3.10 (10c) are as follows:
3427 -- Size and initial value is known at compile time
3428 -- Access type is access-to-constant
3430 -- The allocator is not part of a constraint on a record component,
3431 -- because in that case the inserted actions are delayed until the
3432 -- record declaration is fully analyzed, which is too late for the
3433 -- analysis of the rewritten allocator.
3435 if Is_Access_Constant (PtrT)
3436 and then Nkind (Expression (N)) = N_Qualified_Expression
3437 and then Compile_Time_Known_Value (Expression (Expression (N)))
3438 and then Size_Known_At_Compile_Time (Etype (Expression
3440 and then not Is_Record_Type (Current_Scope)
3442 -- Here we can do the optimization. For the allocator
3446 -- We insert an object declaration
3448 -- Tnn : aliased x := y;
3450 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3451 -- marked as requiring static allocation.
3453 Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
3454 Desig := Subtype_Mark (Expression (N));
3456 -- If context is constrained, use constrained subtype directly,
3457 -- so that the constant is not labelled as having a nominally
3458 -- unconstrained subtype.
3460 if Entity (Desig) = Base_Type (Dtyp) then
3461 Desig := New_Occurrence_Of (Dtyp, Loc);
3465 Make_Object_Declaration (Loc,
3466 Defining_Identifier => Temp,
3467 Aliased_Present => True,
3468 Constant_Present => Is_Access_Constant (PtrT),
3469 Object_Definition => Desig,
3470 Expression => Expression (Expression (N))));
3473 Make_Attribute_Reference (Loc,
3474 Prefix => New_Occurrence_Of (Temp, Loc),
3475 Attribute_Name => Name_Unrestricted_Access));
3477 Analyze_And_Resolve (N, PtrT);
3479 -- We set the variable as statically allocated, since we don't want
3480 -- it going on the stack of the current procedure!
3482 Set_Is_Statically_Allocated (Temp);
3486 -- Same if the allocator is an access discriminant for a local object:
3487 -- instead of an allocator we create a local value and constrain the
3488 -- the enclosing object with the corresponding access attribute.
3490 if Is_Static_Coextension (N) then
3491 Rewrite_Coextension (N);
3495 -- The current allocator creates an object which may contain nested
3496 -- coextensions. Use the current allocator's finalization list to
3497 -- generate finalization call for all nested coextensions.
3499 if Is_Coextension_Root (N) then
3500 Complete_Coextension_Finalization;
3503 -- Check for size too large, we do this because the back end misses
3504 -- proper checks here and can generate rubbish allocation calls when
3505 -- we are near the limit. We only do this for the 32-bit address case
3506 -- since that is from a practical point of view where we see a problem.
3508 if System_Address_Size = 32
3509 and then not Storage_Checks_Suppressed (PtrT)
3510 and then not Storage_Checks_Suppressed (Dtyp)
3511 and then not Storage_Checks_Suppressed (Etyp)
3513 -- The check we want to generate should look like
3515 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
3516 -- raise Storage_Error;
3519 -- where 3.5 gigabytes is a constant large enough to accomodate any
3520 -- reasonable request for. But we can't do it this way because at
3521 -- least at the moment we don't compute this attribute right, and
3522 -- can silently give wrong results when the result gets large. Since
3523 -- this is all about large results, that's bad, so instead we only
3524 -- apply the check for constrained arrays, and manually compute the
3525 -- value of the attribute ???
3527 if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
3529 Make_Raise_Storage_Error (Loc,
3532 Left_Opnd => Size_In_Storage_Elements (Etyp),
3534 Make_Integer_Literal (Loc,
3535 Intval => Uint_7 * (Uint_2 ** 29))),
3536 Reason => SE_Object_Too_Large));
3540 -- Handle case of qualified expression (other than optimization above)
3541 -- First apply constraint checks, because the bounds or discriminants
3542 -- in the aggregate might not match the subtype mark in the allocator.
3544 if Nkind (Expression (N)) = N_Qualified_Expression then
3545 Apply_Constraint_Check
3546 (Expression (Expression (N)), Etype (Expression (N)));
3548 Expand_Allocator_Expression (N);
3552 -- If the allocator is for a type which requires initialization, and
3553 -- there is no initial value (i.e. operand is a subtype indication
3554 -- rather than a qualified expression), then we must generate a call to
3555 -- the initialization routine using an expressions action node:
3557 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3559 -- Here ptr_T is the pointer type for the allocator, and T is the
3560 -- subtype of the allocator. A special case arises if the designated
3561 -- type of the access type is a task or contains tasks. In this case
3562 -- the call to Init (Temp.all ...) is replaced by code that ensures
3563 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3564 -- for details). In addition, if the type T is a task T, then the
3565 -- first argument to Init must be converted to the task record type.
3568 T : constant Entity_Id := Entity (Expression (N));
3576 Temp_Decl : Node_Id;
3577 Temp_Type : Entity_Id;
3578 Attach_Level : Uint;
3581 if No_Initialization (N) then
3584 -- Case of no initialization procedure present
3586 elsif not Has_Non_Null_Base_Init_Proc (T) then
3588 -- Case of simple initialization required
3590 if Needs_Simple_Initialization (T) then
3591 Check_Restriction (No_Default_Initialization, N);
3592 Rewrite (Expression (N),
3593 Make_Qualified_Expression (Loc,
3594 Subtype_Mark => New_Occurrence_Of (T, Loc),
3595 Expression => Get_Simple_Init_Val (T, N)));
3597 Analyze_And_Resolve (Expression (Expression (N)), T);
3598 Analyze_And_Resolve (Expression (N), T);
3599 Set_Paren_Count (Expression (Expression (N)), 1);
3600 Expand_N_Allocator (N);
3602 -- No initialization required
3608 -- Case of initialization procedure present, must be called
3611 Check_Restriction (No_Default_Initialization, N);
3613 if not Restriction_Active (No_Default_Initialization) then
3614 Init := Base_Init_Proc (T);
3616 Temp := Make_Temporary (Loc, 'P');
3618 -- Construct argument list for the initialization routine call
3621 Make_Explicit_Dereference (Loc,
3622 Prefix => New_Reference_To (Temp, Loc));
3623 Set_Assignment_OK (Arg1);
3626 -- The initialization procedure expects a specific type. if the
3627 -- context is access to class wide, indicate that the object
3628 -- being allocated has the right specific type.
3630 if Is_Class_Wide_Type (Dtyp) then
3631 Arg1 := Unchecked_Convert_To (T, Arg1);
3634 -- If designated type is a concurrent type or if it is private
3635 -- type whose definition is a concurrent type, the first
3636 -- argument in the Init routine has to be unchecked conversion
3637 -- to the corresponding record type. If the designated type is
3638 -- a derived type, we also convert the argument to its root
3641 if Is_Concurrent_Type (T) then
3643 Unchecked_Convert_To (Corresponding_Record_Type (T), Arg1);
3645 elsif Is_Private_Type (T)
3646 and then Present (Full_View (T))
3647 and then Is_Concurrent_Type (Full_View (T))
3650 Unchecked_Convert_To
3651 (Corresponding_Record_Type (Full_View (T)), Arg1);
3653 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3655 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3657 Arg1 := OK_Convert_To (Etype (Ftyp), Arg1);
3658 Set_Etype (Arg1, Ftyp);
3662 Args := New_List (Arg1);
3664 -- For the task case, pass the Master_Id of the access type as
3665 -- the value of the _Master parameter, and _Chain as the value
3666 -- of the _Chain parameter (_Chain will be defined as part of
3667 -- the generated code for the allocator).
3669 -- In Ada 2005, the context may be a function that returns an
3670 -- anonymous access type. In that case the Master_Id has been
3671 -- created when expanding the function declaration.
3673 if Has_Task (T) then
3674 if No (Master_Id (Base_Type (PtrT))) then
3676 -- The designated type was an incomplete type, and the
3677 -- access type did not get expanded. Salvage it now.
3679 if not Restriction_Active (No_Task_Hierarchy) then
3680 pragma Assert (Present (Parent (Base_Type (PtrT))));
3681 Expand_N_Full_Type_Declaration
3682 (Parent (Base_Type (PtrT)));
3686 -- If the context of the allocator is a declaration or an
3687 -- assignment, we can generate a meaningful image for it,
3688 -- even though subsequent assignments might remove the
3689 -- connection between task and entity. We build this image
3690 -- when the left-hand side is a simple variable, a simple
3691 -- indexed assignment or a simple selected component.
3693 if Nkind (Parent (N)) = N_Assignment_Statement then
3695 Nam : constant Node_Id := Name (Parent (N));
3698 if Is_Entity_Name (Nam) then
3700 Build_Task_Image_Decls
3703 (Entity (Nam), Sloc (Nam)), T);
3706 (Nam, N_Indexed_Component, N_Selected_Component)
3707 and then Is_Entity_Name (Prefix (Nam))
3710 Build_Task_Image_Decls
3711 (Loc, Nam, Etype (Prefix (Nam)));
3713 Decls := Build_Task_Image_Decls (Loc, T, T);
3717 elsif Nkind (Parent (N)) = N_Object_Declaration then
3719 Build_Task_Image_Decls
3720 (Loc, Defining_Identifier (Parent (N)), T);
3723 Decls := Build_Task_Image_Decls (Loc, T, T);
3726 if Restriction_Active (No_Task_Hierarchy) then
3728 New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
3732 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3735 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3737 Decl := Last (Decls);
3739 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3741 -- Has_Task is false, Decls not used
3747 -- Add discriminants if discriminated type
3750 Dis : Boolean := False;
3754 if Has_Discriminants (T) then
3758 elsif Is_Private_Type (T)
3759 and then Present (Full_View (T))
3760 and then Has_Discriminants (Full_View (T))
3763 Typ := Full_View (T);
3768 -- If the allocated object will be constrained by the
3769 -- default values for discriminants, then build a subtype
3770 -- with those defaults, and change the allocated subtype
3771 -- to that. Note that this happens in fewer cases in Ada
3774 if not Is_Constrained (Typ)
3775 and then Present (Discriminant_Default_Value
3776 (First_Discriminant (Typ)))
3777 and then (Ada_Version < Ada_2005
3779 not Has_Constrained_Partial_View (Typ))
3781 Typ := Build_Default_Subtype (Typ, N);
3782 Set_Expression (N, New_Reference_To (Typ, Loc));
3785 Discr := First_Elmt (Discriminant_Constraint (Typ));
3786 while Present (Discr) loop
3787 Nod := Node (Discr);
3788 Append (New_Copy_Tree (Node (Discr)), Args);
3790 -- AI-416: when the discriminant constraint is an
3791 -- anonymous access type make sure an accessibility
3792 -- check is inserted if necessary (3.10.2(22.q/2))
3794 if Ada_Version >= Ada_2005
3796 Ekind (Etype (Nod)) = E_Anonymous_Access_Type
3798 Apply_Accessibility_Check
3799 (Nod, Typ, Insert_Node => Nod);
3807 -- We set the allocator as analyzed so that when we analyze the
3808 -- expression actions node, we do not get an unwanted recursive
3809 -- expansion of the allocator expression.
3811 Set_Analyzed (N, True);
3812 Nod := Relocate_Node (N);
3814 -- Here is the transformation:
3816 -- output: Temp : constant ptr_T := new T;
3817 -- Init (Temp.all, ...);
3818 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
3819 -- <CTRL> Initialize (Finalizable (Temp.all));
3821 -- Here ptr_T is the pointer type for the allocator, and is the
3822 -- subtype of the allocator.
3825 Make_Object_Declaration (Loc,
3826 Defining_Identifier => Temp,
3827 Constant_Present => True,
3828 Object_Definition => New_Reference_To (Temp_Type, Loc),
3831 Set_Assignment_OK (Temp_Decl);
3832 Insert_Action (N, Temp_Decl, Suppress => All_Checks);
3834 -- If the designated type is a task type or contains tasks,
3835 -- create block to activate created tasks, and insert
3836 -- declaration for Task_Image variable ahead of call.
3838 if Has_Task (T) then
3840 L : constant List_Id := New_List;
3843 Build_Task_Allocate_Block (L, Nod, Args);
3845 Insert_List_Before (First (Declarations (Blk)), Decls);
3846 Insert_Actions (N, L);
3851 Make_Procedure_Call_Statement (Loc,
3852 Name => New_Reference_To (Init, Loc),
3853 Parameter_Associations => Args));
3856 if Needs_Finalization (T) then
3858 -- Postpone the generation of a finalization call for the
3859 -- current allocator if it acts as a coextension.
3861 if Is_Dynamic_Coextension (N) then
3862 if No (Coextensions (N)) then
3863 Set_Coextensions (N, New_Elmt_List);
3866 Append_Elmt (New_Copy_Tree (Arg1), Coextensions (N));
3870 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
3872 -- Anonymous access types created for access parameters
3873 -- are attached to an explicitly constructed controller,
3874 -- which ensures that they can be finalized properly,
3875 -- even if their deallocation might not happen. The list
3876 -- associated with the controller is doubly-linked. For
3877 -- other anonymous access types, the object may end up
3878 -- on the global final list which is singly-linked.
3879 -- Work needed for access discriminants in Ada 2005 ???
3881 if Ekind (PtrT) = E_Anonymous_Access_Type then
3882 Attach_Level := Uint_1;
3884 Attach_Level := Uint_2;
3889 Ref => New_Copy_Tree (Arg1),
3892 With_Attach => Make_Integer_Literal (Loc,
3893 Intval => Attach_Level)));
3897 Rewrite (N, New_Reference_To (Temp, Loc));
3898 Analyze_And_Resolve (N, PtrT);
3903 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
3904 -- object that has been rewritten as a reference, we displace "this"
3905 -- to reference properly its secondary dispatch table.
3907 if Nkind (N) = N_Identifier
3908 and then Is_Interface (Dtyp)
3910 Displace_Allocator_Pointer (N);
3914 when RE_Not_Available =>
3916 end Expand_N_Allocator;
3918 -----------------------
3919 -- Expand_N_And_Then --
3920 -----------------------
3922 procedure Expand_N_And_Then (N : Node_Id)
3923 renames Expand_Short_Circuit_Operator;
3925 ------------------------------
3926 -- Expand_N_Case_Expression --
3927 ------------------------------
3929 procedure Expand_N_Case_Expression (N : Node_Id) is
3930 Loc : constant Source_Ptr := Sloc (N);
3931 Typ : constant Entity_Id := Etype (N);
3943 -- case X is when A => AX, when B => BX ...
3958 -- However, this expansion is wrong for limited types, and also
3959 -- wrong for unconstrained types (since the bounds may not be the
3960 -- same in all branches). Furthermore it involves an extra copy
3961 -- for large objects. So we take care of this by using the following
3962 -- modified expansion for non-scalar types:
3965 -- type Pnn is access all typ;
3969 -- T := AX'Unrestricted_Access;
3971 -- T := BX'Unrestricted_Access;
3977 Make_Case_Statement (Loc,
3978 Expression => Expression (N),
3979 Alternatives => New_List);
3981 Actions := New_List;
3985 if Is_Scalar_Type (Typ) then
3989 Pnn := Make_Temporary (Loc, 'P');
3991 Make_Full_Type_Declaration (Loc,
3992 Defining_Identifier => Pnn,
3994 Make_Access_To_Object_Definition (Loc,
3995 All_Present => True,
3996 Subtype_Indication =>
3997 New_Reference_To (Typ, Loc))));
4001 Tnn := Make_Temporary (Loc, 'T');
4003 Make_Object_Declaration (Loc,
4004 Defining_Identifier => Tnn,
4005 Object_Definition => New_Occurrence_Of (Ttyp, Loc)));
4007 -- Now process the alternatives
4009 Alt := First (Alternatives (N));
4010 while Present (Alt) loop
4012 Aexp : Node_Id := Expression (Alt);
4013 Aloc : constant Source_Ptr := Sloc (Aexp);
4016 if not Is_Scalar_Type (Typ) then
4018 Make_Attribute_Reference (Aloc,
4019 Prefix => Relocate_Node (Aexp),
4020 Attribute_Name => Name_Unrestricted_Access);
4024 (Alternatives (Cstmt),
4025 Make_Case_Statement_Alternative (Sloc (Alt),
4026 Discrete_Choices => Discrete_Choices (Alt),
4027 Statements => New_List (
4028 Make_Assignment_Statement (Aloc,
4029 Name => New_Occurrence_Of (Tnn, Loc),
4030 Expression => Aexp))));
4036 Append_To (Actions, Cstmt);
4038 -- Construct and return final expression with actions
4040 if Is_Scalar_Type (Typ) then
4041 Fexp := New_Occurrence_Of (Tnn, Loc);
4044 Make_Explicit_Dereference (Loc,
4045 Prefix => New_Occurrence_Of (Tnn, Loc));
4049 Make_Expression_With_Actions (Loc,
4051 Actions => Actions));
4053 Analyze_And_Resolve (N, Typ);
4054 end Expand_N_Case_Expression;
4056 -------------------------------------
4057 -- Expand_N_Conditional_Expression --
4058 -------------------------------------
4060 -- Deal with limited types and expression actions
4062 procedure Expand_N_Conditional_Expression (N : Node_Id) is
4063 Loc : constant Source_Ptr := Sloc (N);
4064 Cond : constant Node_Id := First (Expressions (N));
4065 Thenx : constant Node_Id := Next (Cond);
4066 Elsex : constant Node_Id := Next (Thenx);
4067 Typ : constant Entity_Id := Etype (N);
4078 -- Fold at compile time if condition known. We have already folded
4079 -- static conditional expressions, but it is possible to fold any
4080 -- case in which the condition is known at compile time, even though
4081 -- the result is non-static.
4083 -- Note that we don't do the fold of such cases in Sem_Elab because
4084 -- it can cause infinite loops with the expander adding a conditional
4085 -- expression, and Sem_Elab circuitry removing it repeatedly.
4087 if Compile_Time_Known_Value (Cond) then
4088 if Is_True (Expr_Value (Cond)) then
4090 Actions := Then_Actions (N);
4093 Actions := Else_Actions (N);
4098 if Present (Actions) then
4100 -- If we are not allowed to use Expression_With_Actions, just
4101 -- skip the optimization, it is not critical for correctness.
4103 if not Use_Expression_With_Actions then
4104 goto Skip_Optimization;
4108 Make_Expression_With_Actions (Loc,
4109 Expression => Relocate_Node (Expr),
4110 Actions => Actions));
4111 Analyze_And_Resolve (N, Typ);
4114 Rewrite (N, Relocate_Node (Expr));
4117 -- Note that the result is never static (legitimate cases of static
4118 -- conditional expressions were folded in Sem_Eval).
4120 Set_Is_Static_Expression (N, False);
4124 <<Skip_Optimization>>
4126 -- If the type is limited or unconstrained, we expand as follows to
4127 -- avoid any possibility of improper copies.
4129 -- Note: it may be possible to avoid this special processing if the
4130 -- back end uses its own mechanisms for handling by-reference types ???
4132 -- type Ptr is access all Typ;
4136 -- Cnn := then-expr'Unrestricted_Access;
4139 -- Cnn := else-expr'Unrestricted_Access;
4142 -- and replace the conditional expresion by a reference to Cnn.all.
4144 -- This special case can be skipped if the back end handles limited
4145 -- types properly and ensures that no incorrect copies are made.
4147 if Is_By_Reference_Type (Typ)
4148 and then not Back_End_Handles_Limited_Types
4150 Cnn := Make_Temporary (Loc, 'C', N);
4153 Make_Full_Type_Declaration (Loc,
4154 Defining_Identifier => Make_Temporary (Loc, 'A'),
4156 Make_Access_To_Object_Definition (Loc,
4157 All_Present => True,
4158 Subtype_Indication =>
4159 New_Reference_To (Typ, Loc)));
4161 Insert_Action (N, P_Decl);
4164 Make_Object_Declaration (Loc,
4165 Defining_Identifier => Cnn,
4166 Object_Definition =>
4167 New_Occurrence_Of (Defining_Identifier (P_Decl), Loc));
4170 Make_Implicit_If_Statement (N,
4171 Condition => Relocate_Node (Cond),
4173 Then_Statements => New_List (
4174 Make_Assignment_Statement (Sloc (Thenx),
4175 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4177 Make_Attribute_Reference (Loc,
4178 Attribute_Name => Name_Unrestricted_Access,
4179 Prefix => Relocate_Node (Thenx)))),
4181 Else_Statements => New_List (
4182 Make_Assignment_Statement (Sloc (Elsex),
4183 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4185 Make_Attribute_Reference (Loc,
4186 Attribute_Name => Name_Unrestricted_Access,
4187 Prefix => Relocate_Node (Elsex)))));
4190 Make_Explicit_Dereference (Loc,
4191 Prefix => New_Occurrence_Of (Cnn, Loc));
4193 -- For other types, we only need to expand if there are other actions
4194 -- associated with either branch.
4196 elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
4198 -- We have two approaches to handling this. If we are allowed to use
4199 -- N_Expression_With_Actions, then we can just wrap the actions into
4200 -- the appropriate expression.
4202 if Use_Expression_With_Actions then
4203 if Present (Then_Actions (N)) then
4205 Make_Expression_With_Actions (Sloc (Thenx),
4206 Actions => Then_Actions (N),
4207 Expression => Relocate_Node (Thenx)));
4208 Set_Then_Actions (N, No_List);
4209 Analyze_And_Resolve (Thenx, Typ);
4212 if Present (Else_Actions (N)) then
4214 Make_Expression_With_Actions (Sloc (Elsex),
4215 Actions => Else_Actions (N),
4216 Expression => Relocate_Node (Elsex)));
4217 Set_Else_Actions (N, No_List);
4218 Analyze_And_Resolve (Elsex, Typ);
4223 -- if we can't use N_Expression_With_Actions nodes, then we insert
4224 -- the following sequence of actions (using Insert_Actions):
4229 -- Cnn := then-expr;
4235 -- and replace the conditional expression by a reference to Cnn
4238 Cnn := Make_Temporary (Loc, 'C', N);
4241 Make_Object_Declaration (Loc,
4242 Defining_Identifier => Cnn,
4243 Object_Definition => New_Occurrence_Of (Typ, Loc));
4246 Make_Implicit_If_Statement (N,
4247 Condition => Relocate_Node (Cond),
4249 Then_Statements => New_List (
4250 Make_Assignment_Statement (Sloc (Thenx),
4251 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4252 Expression => Relocate_Node (Thenx))),
4254 Else_Statements => New_List (
4255 Make_Assignment_Statement (Sloc (Elsex),
4256 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4257 Expression => Relocate_Node (Elsex))));
4259 Set_Assignment_OK (Name (First (Then_Statements (New_If))));
4260 Set_Assignment_OK (Name (First (Else_Statements (New_If))));
4262 New_N := New_Occurrence_Of (Cnn, Loc);
4265 -- If no actions then no expansion needed, gigi will handle it using
4266 -- the same approach as a C conditional expression.
4272 -- Fall through here for either the limited expansion, or the case of
4273 -- inserting actions for non-limited types. In both these cases, we must
4274 -- move the SLOC of the parent If statement to the newly created one and
4275 -- change it to the SLOC of the expression which, after expansion, will
4276 -- correspond to what is being evaluated.
4278 if Present (Parent (N))
4279 and then Nkind (Parent (N)) = N_If_Statement
4281 Set_Sloc (New_If, Sloc (Parent (N)));
4282 Set_Sloc (Parent (N), Loc);
4285 -- Make sure Then_Actions and Else_Actions are appropriately moved
4286 -- to the new if statement.
4288 if Present (Then_Actions (N)) then
4290 (First (Then_Statements (New_If)), Then_Actions (N));
4293 if Present (Else_Actions (N)) then
4295 (First (Else_Statements (New_If)), Else_Actions (N));
4298 Insert_Action (N, Decl);
4299 Insert_Action (N, New_If);
4301 Analyze_And_Resolve (N, Typ);
4302 end Expand_N_Conditional_Expression;
4304 -----------------------------------
4305 -- Expand_N_Explicit_Dereference --
4306 -----------------------------------
4308 procedure Expand_N_Explicit_Dereference (N : Node_Id) is
4310 -- Insert explicit dereference call for the checked storage pool case
4312 Insert_Dereference_Action (Prefix (N));
4313 end Expand_N_Explicit_Dereference;
4319 procedure Expand_N_In (N : Node_Id) is
4320 Loc : constant Source_Ptr := Sloc (N);
4321 Rtyp : constant Entity_Id := Etype (N);
4322 Lop : constant Node_Id := Left_Opnd (N);
4323 Rop : constant Node_Id := Right_Opnd (N);
4324 Static : constant Boolean := Is_OK_Static_Expression (N);
4326 procedure Expand_Set_Membership;
4327 -- For each disjunct we create a simple equality or membership test.
4328 -- The whole membership is rewritten as a short-circuit disjunction.
4330 ---------------------------
4331 -- Expand_Set_Membership --
4332 ---------------------------
4334 procedure Expand_Set_Membership is
4338 function Make_Cond (Alt : Node_Id) return Node_Id;
4339 -- If the alternative is a subtype mark, create a simple membership
4340 -- test. Otherwise create an equality test for it.
4346 function Make_Cond (Alt : Node_Id) return Node_Id is
4348 L : constant Node_Id := New_Copy (Lop);
4349 R : constant Node_Id := Relocate_Node (Alt);
4352 if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
4353 or else Nkind (Alt) = N_Range
4356 Make_In (Sloc (Alt),
4361 Make_Op_Eq (Sloc (Alt),
4369 -- Start of processing for Expand_N_In
4372 Alt := Last (Alternatives (N));
4373 Res := Make_Cond (Alt);
4376 while Present (Alt) loop
4378 Make_Or_Else (Sloc (Alt),
4379 Left_Opnd => Make_Cond (Alt),
4385 Analyze_And_Resolve (N, Standard_Boolean);
4386 end Expand_Set_Membership;
4388 procedure Substitute_Valid_Check;
4389 -- Replaces node N by Lop'Valid. This is done when we have an explicit
4390 -- test for the left operand being in range of its subtype.
4392 ----------------------------
4393 -- Substitute_Valid_Check --
4394 ----------------------------
4396 procedure Substitute_Valid_Check is
4399 Make_Attribute_Reference (Loc,
4400 Prefix => Relocate_Node (Lop),
4401 Attribute_Name => Name_Valid));
4403 Analyze_And_Resolve (N, Rtyp);
4405 Error_Msg_N ("?explicit membership test may be optimized away", N);
4406 Error_Msg_N -- CODEFIX
4407 ("\?use ''Valid attribute instead", N);
4409 end Substitute_Valid_Check;
4411 -- Start of processing for Expand_N_In
4414 if Present (Alternatives (N)) then
4415 Remove_Side_Effects (Lop);
4416 Expand_Set_Membership;
4420 -- Check case of explicit test for an expression in range of its
4421 -- subtype. This is suspicious usage and we replace it with a 'Valid
4422 -- test and give a warning. For floating point types however, this is a
4423 -- standard way to check for finite numbers, and using 'Valid would
4424 -- typically be a pessimization.
4426 if Is_Scalar_Type (Etype (Lop))
4427 and then not Is_Floating_Point_Type (Etype (Lop))
4428 and then Nkind (Rop) in N_Has_Entity
4429 and then Etype (Lop) = Entity (Rop)
4430 and then Comes_From_Source (N)
4431 and then VM_Target = No_VM
4433 Substitute_Valid_Check;
4437 -- Do validity check on operands
4439 if Validity_Checks_On and Validity_Check_Operands then
4440 Ensure_Valid (Left_Opnd (N));
4441 Validity_Check_Range (Right_Opnd (N));
4444 -- Case of explicit range
4446 if Nkind (Rop) = N_Range then
4448 Lo : constant Node_Id := Low_Bound (Rop);
4449 Hi : constant Node_Id := High_Bound (Rop);
4451 Ltyp : constant Entity_Id := Etype (Lop);
4453 Lo_Orig : constant Node_Id := Original_Node (Lo);
4454 Hi_Orig : constant Node_Id := Original_Node (Hi);
4456 Lcheck : Compare_Result;
4457 Ucheck : Compare_Result;
4459 Warn1 : constant Boolean :=
4460 Constant_Condition_Warnings
4461 and then Comes_From_Source (N)
4462 and then not In_Instance;
4463 -- This must be true for any of the optimization warnings, we
4464 -- clearly want to give them only for source with the flag on. We
4465 -- also skip these warnings in an instance since it may be the
4466 -- case that different instantiations have different ranges.
4468 Warn2 : constant Boolean :=
4470 and then Nkind (Original_Node (Rop)) = N_Range
4471 and then Is_Integer_Type (Etype (Lo));
4472 -- For the case where only one bound warning is elided, we also
4473 -- insist on an explicit range and an integer type. The reason is
4474 -- that the use of enumeration ranges including an end point is
4475 -- common, as is the use of a subtype name, one of whose bounds is
4476 -- the same as the type of the expression.
4479 -- If test is explicit x'First .. x'Last, replace by valid check
4481 -- Could use some individual comments for this complex test ???
4483 if Is_Scalar_Type (Ltyp)
4484 and then Nkind (Lo_Orig) = N_Attribute_Reference
4485 and then Attribute_Name (Lo_Orig) = Name_First
4486 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
4487 and then Entity (Prefix (Lo_Orig)) = Ltyp
4488 and then Nkind (Hi_Orig) = N_Attribute_Reference
4489 and then Attribute_Name (Hi_Orig) = Name_Last
4490 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
4491 and then Entity (Prefix (Hi_Orig)) = Ltyp
4492 and then Comes_From_Source (N)
4493 and then VM_Target = No_VM
4495 Substitute_Valid_Check;
4499 -- If bounds of type are known at compile time, and the end points
4500 -- are known at compile time and identical, this is another case
4501 -- for substituting a valid test. We only do this for discrete
4502 -- types, since it won't arise in practice for float types.
4504 if Comes_From_Source (N)
4505 and then Is_Discrete_Type (Ltyp)
4506 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
4507 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
4508 and then Compile_Time_Known_Value (Lo)
4509 and then Compile_Time_Known_Value (Hi)
4510 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
4511 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
4513 -- Kill warnings in instances, since they may be cases where we
4514 -- have a test in the generic that makes sense with some types
4515 -- and not with other types.
4517 and then not In_Instance
4519 Substitute_Valid_Check;
4523 -- If we have an explicit range, do a bit of optimization based on
4524 -- range analysis (we may be able to kill one or both checks).
4526 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
4527 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
4529 -- If either check is known to fail, replace result by False since
4530 -- the other check does not matter. Preserve the static flag for
4531 -- legality checks, because we are constant-folding beyond RM 4.9.
4533 if Lcheck = LT or else Ucheck = GT then
4535 Error_Msg_N ("?range test optimized away", N);
4536 Error_Msg_N ("\?value is known to be out of range", N);
4539 Rewrite (N, New_Reference_To (Standard_False, Loc));
4540 Analyze_And_Resolve (N, Rtyp);
4541 Set_Is_Static_Expression (N, Static);
4545 -- If both checks are known to succeed, replace result by True,
4546 -- since we know we are in range.
4548 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4550 Error_Msg_N ("?range test optimized away", N);
4551 Error_Msg_N ("\?value is known to be in range", N);
4554 Rewrite (N, New_Reference_To (Standard_True, Loc));
4555 Analyze_And_Resolve (N, Rtyp);
4556 Set_Is_Static_Expression (N, Static);
4560 -- If lower bound check succeeds and upper bound check is not
4561 -- known to succeed or fail, then replace the range check with
4562 -- a comparison against the upper bound.
4564 elsif Lcheck in Compare_GE then
4565 if Warn2 and then not In_Instance then
4566 Error_Msg_N ("?lower bound test optimized away", Lo);
4567 Error_Msg_N ("\?value is known to be in range", Lo);
4573 Right_Opnd => High_Bound (Rop)));
4574 Analyze_And_Resolve (N, Rtyp);
4578 -- If upper bound check succeeds and lower bound check is not
4579 -- known to succeed or fail, then replace the range check with
4580 -- a comparison against the lower bound.
4582 elsif Ucheck in Compare_LE then
4583 if Warn2 and then not In_Instance then
4584 Error_Msg_N ("?upper bound test optimized away", Hi);
4585 Error_Msg_N ("\?value is known to be in range", Hi);
4591 Right_Opnd => Low_Bound (Rop)));
4592 Analyze_And_Resolve (N, Rtyp);
4597 -- We couldn't optimize away the range check, but there is one
4598 -- more issue. If we are checking constant conditionals, then we
4599 -- see if we can determine the outcome assuming everything is
4600 -- valid, and if so give an appropriate warning.
4602 if Warn1 and then not Assume_No_Invalid_Values then
4603 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4604 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4606 -- Result is out of range for valid value
4608 if Lcheck = LT or else Ucheck = GT then
4610 ("?value can only be in range if it is invalid", N);
4612 -- Result is in range for valid value
4614 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4616 ("?value can only be out of range if it is invalid", N);
4618 -- Lower bound check succeeds if value is valid
4620 elsif Warn2 and then Lcheck in Compare_GE then
4622 ("?lower bound check only fails if it is invalid", Lo);
4624 -- Upper bound check succeeds if value is valid
4626 elsif Warn2 and then Ucheck in Compare_LE then
4628 ("?upper bound check only fails for invalid values", Hi);
4633 -- For all other cases of an explicit range, nothing to be done
4637 -- Here right operand is a subtype mark
4641 Typ : Entity_Id := Etype (Rop);
4642 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4643 Cond : Node_Id := Empty;
4645 Obj : Node_Id := Lop;
4646 SCIL_Node : Node_Id;
4649 Remove_Side_Effects (Obj);
4651 -- For tagged type, do tagged membership operation
4653 if Is_Tagged_Type (Typ) then
4655 -- No expansion will be performed when VM_Target, as the VM
4656 -- back-ends will handle the membership tests directly (tags
4657 -- are not explicitly represented in Java objects, so the
4658 -- normal tagged membership expansion is not what we want).
4660 if Tagged_Type_Expansion then
4661 Tagged_Membership (N, SCIL_Node, New_N);
4663 Analyze_And_Resolve (N, Rtyp);
4665 -- Update decoration of relocated node referenced by the
4668 if Generate_SCIL and then Present (SCIL_Node) then
4669 Set_SCIL_Node (N, SCIL_Node);
4675 -- If type is scalar type, rewrite as x in t'First .. t'Last.
4676 -- This reason we do this is that the bounds may have the wrong
4677 -- type if they come from the original type definition. Also this
4678 -- way we get all the processing above for an explicit range.
4680 elsif Is_Scalar_Type (Typ) then
4684 Make_Attribute_Reference (Loc,
4685 Attribute_Name => Name_First,
4686 Prefix => New_Reference_To (Typ, Loc)),
4689 Make_Attribute_Reference (Loc,
4690 Attribute_Name => Name_Last,
4691 Prefix => New_Reference_To (Typ, Loc))));
4692 Analyze_And_Resolve (N, Rtyp);
4695 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4696 -- a membership test if the subtype mark denotes a constrained
4697 -- Unchecked_Union subtype and the expression lacks inferable
4700 elsif Is_Unchecked_Union (Base_Type (Typ))
4701 and then Is_Constrained (Typ)
4702 and then not Has_Inferable_Discriminants (Lop)
4705 Make_Raise_Program_Error (Loc,
4706 Reason => PE_Unchecked_Union_Restriction));
4708 -- Prevent Gigi from generating incorrect code by rewriting the
4711 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
4715 -- Here we have a non-scalar type
4718 Typ := Designated_Type (Typ);
4721 if not Is_Constrained (Typ) then
4722 Rewrite (N, New_Reference_To (Standard_True, Loc));
4723 Analyze_And_Resolve (N, Rtyp);
4725 -- For the constrained array case, we have to check the subscripts
4726 -- for an exact match if the lengths are non-zero (the lengths
4727 -- must match in any case).
4729 elsif Is_Array_Type (Typ) then
4730 Check_Subscripts : declare
4731 function Build_Attribute_Reference
4734 Dim : Nat) return Node_Id;
4735 -- Build attribute reference E'Nam (Dim)
4737 -------------------------------
4738 -- Build_Attribute_Reference --
4739 -------------------------------
4741 function Build_Attribute_Reference
4744 Dim : Nat) return Node_Id
4748 Make_Attribute_Reference (Loc,
4750 Attribute_Name => Nam,
4751 Expressions => New_List (
4752 Make_Integer_Literal (Loc, Dim)));
4753 end Build_Attribute_Reference;
4755 -- Start of processing for Check_Subscripts
4758 for J in 1 .. Number_Dimensions (Typ) loop
4759 Evolve_And_Then (Cond,
4762 Build_Attribute_Reference
4763 (Duplicate_Subexpr_No_Checks (Obj),
4766 Build_Attribute_Reference
4767 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
4769 Evolve_And_Then (Cond,
4772 Build_Attribute_Reference
4773 (Duplicate_Subexpr_No_Checks (Obj),
4776 Build_Attribute_Reference
4777 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
4786 Right_Opnd => Make_Null (Loc)),
4787 Right_Opnd => Cond);
4791 Analyze_And_Resolve (N, Rtyp);
4792 end Check_Subscripts;
4794 -- These are the cases where constraint checks may be required,
4795 -- e.g. records with possible discriminants
4798 -- Expand the test into a series of discriminant comparisons.
4799 -- The expression that is built is the negation of the one that
4800 -- is used for checking discriminant constraints.
4802 Obj := Relocate_Node (Left_Opnd (N));
4804 if Has_Discriminants (Typ) then
4805 Cond := Make_Op_Not (Loc,
4806 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
4809 Cond := Make_Or_Else (Loc,
4813 Right_Opnd => Make_Null (Loc)),
4814 Right_Opnd => Cond);
4818 Cond := New_Occurrence_Of (Standard_True, Loc);
4822 Analyze_And_Resolve (N, Rtyp);
4828 --------------------------------
4829 -- Expand_N_Indexed_Component --
4830 --------------------------------
4832 procedure Expand_N_Indexed_Component (N : Node_Id) is
4833 Loc : constant Source_Ptr := Sloc (N);
4834 Typ : constant Entity_Id := Etype (N);
4835 P : constant Node_Id := Prefix (N);
4836 T : constant Entity_Id := Etype (P);
4839 -- A special optimization, if we have an indexed component that is
4840 -- selecting from a slice, then we can eliminate the slice, since, for
4841 -- example, x (i .. j)(k) is identical to x(k). The only difference is
4842 -- the range check required by the slice. The range check for the slice
4843 -- itself has already been generated. The range check for the
4844 -- subscripting operation is ensured by converting the subject to
4845 -- the subtype of the slice.
4847 -- This optimization not only generates better code, avoiding slice
4848 -- messing especially in the packed case, but more importantly bypasses
4849 -- some problems in handling this peculiar case, for example, the issue
4850 -- of dealing specially with object renamings.
4852 if Nkind (P) = N_Slice then
4854 Make_Indexed_Component (Loc,
4855 Prefix => Prefix (P),
4856 Expressions => New_List (
4858 (Etype (First_Index (Etype (P))),
4859 First (Expressions (N))))));
4860 Analyze_And_Resolve (N, Typ);
4864 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
4865 -- function, then additional actuals must be passed.
4867 if Ada_Version >= Ada_2005
4868 and then Is_Build_In_Place_Function_Call (P)
4870 Make_Build_In_Place_Call_In_Anonymous_Context (P);
4873 -- If the prefix is an access type, then we unconditionally rewrite if
4874 -- as an explicit dereference. This simplifies processing for several
4875 -- cases, including packed array cases and certain cases in which checks
4876 -- must be generated. We used to try to do this only when it was
4877 -- necessary, but it cleans up the code to do it all the time.
4879 if Is_Access_Type (T) then
4880 Insert_Explicit_Dereference (P);
4881 Analyze_And_Resolve (P, Designated_Type (T));
4884 -- Generate index and validity checks
4886 Generate_Index_Checks (N);
4888 if Validity_Checks_On and then Validity_Check_Subscripts then
4889 Apply_Subscript_Validity_Checks (N);
4892 -- All done for the non-packed case
4894 if not Is_Packed (Etype (Prefix (N))) then
4898 -- For packed arrays that are not bit-packed (i.e. the case of an array
4899 -- with one or more index types with a non-contiguous enumeration type),
4900 -- we can always use the normal packed element get circuit.
4902 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
4903 Expand_Packed_Element_Reference (N);
4907 -- For a reference to a component of a bit packed array, we have to
4908 -- convert it to a reference to the corresponding Packed_Array_Type.
4909 -- We only want to do this for simple references, and not for:
4911 -- Left side of assignment, or prefix of left side of assignment, or
4912 -- prefix of the prefix, to handle packed arrays of packed arrays,
4913 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
4915 -- Renaming objects in renaming associations
4916 -- This case is handled when a use of the renamed variable occurs
4918 -- Actual parameters for a procedure call
4919 -- This case is handled in Exp_Ch6.Expand_Actuals
4921 -- The second expression in a 'Read attribute reference
4923 -- The prefix of an address or bit or size attribute reference
4925 -- The following circuit detects these exceptions
4928 Child : Node_Id := N;
4929 Parnt : Node_Id := Parent (N);
4933 if Nkind (Parnt) = N_Unchecked_Expression then
4936 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
4937 N_Procedure_Call_Statement)
4938 or else (Nkind (Parnt) = N_Parameter_Association
4940 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
4944 elsif Nkind (Parnt) = N_Attribute_Reference
4945 and then (Attribute_Name (Parnt) = Name_Address
4947 Attribute_Name (Parnt) = Name_Bit
4949 Attribute_Name (Parnt) = Name_Size)
4950 and then Prefix (Parnt) = Child
4954 elsif Nkind (Parnt) = N_Assignment_Statement
4955 and then Name (Parnt) = Child
4959 -- If the expression is an index of an indexed component, it must
4960 -- be expanded regardless of context.
4962 elsif Nkind (Parnt) = N_Indexed_Component
4963 and then Child /= Prefix (Parnt)
4965 Expand_Packed_Element_Reference (N);
4968 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
4969 and then Name (Parent (Parnt)) = Parnt
4973 elsif Nkind (Parnt) = N_Attribute_Reference
4974 and then Attribute_Name (Parnt) = Name_Read
4975 and then Next (First (Expressions (Parnt))) = Child
4979 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
4980 and then Prefix (Parnt) = Child
4985 Expand_Packed_Element_Reference (N);
4989 -- Keep looking up tree for unchecked expression, or if we are the
4990 -- prefix of a possible assignment left side.
4993 Parnt := Parent (Child);
4996 end Expand_N_Indexed_Component;
4998 ---------------------
4999 -- Expand_N_Not_In --
5000 ---------------------
5002 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
5003 -- can be done. This avoids needing to duplicate this expansion code.
5005 procedure Expand_N_Not_In (N : Node_Id) is
5006 Loc : constant Source_Ptr := Sloc (N);
5007 Typ : constant Entity_Id := Etype (N);
5008 Cfs : constant Boolean := Comes_From_Source (N);
5015 Left_Opnd => Left_Opnd (N),
5016 Right_Opnd => Right_Opnd (N))));
5018 -- If this is a set membership, preserve list of alternatives
5020 Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
5022 -- We want this to appear as coming from source if original does (see
5023 -- transformations in Expand_N_In).
5025 Set_Comes_From_Source (N, Cfs);
5026 Set_Comes_From_Source (Right_Opnd (N), Cfs);
5028 -- Now analyze transformed node
5030 Analyze_And_Resolve (N, Typ);
5031 end Expand_N_Not_In;
5037 -- The only replacement required is for the case of a null of a type that
5038 -- is an access to protected subprogram, or a subtype thereof. We represent
5039 -- such access values as a record, and so we must replace the occurrence of
5040 -- null by the equivalent record (with a null address and a null pointer in
5041 -- it), so that the backend creates the proper value.
5043 procedure Expand_N_Null (N : Node_Id) is
5044 Loc : constant Source_Ptr := Sloc (N);
5045 Typ : constant Entity_Id := Base_Type (Etype (N));
5049 if Is_Access_Protected_Subprogram_Type (Typ) then
5051 Make_Aggregate (Loc,
5052 Expressions => New_List (
5053 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
5057 Analyze_And_Resolve (N, Equivalent_Type (Typ));
5059 -- For subsequent semantic analysis, the node must retain its type.
5060 -- Gigi in any case replaces this type by the corresponding record
5061 -- type before processing the node.
5067 when RE_Not_Available =>
5071 ---------------------
5072 -- Expand_N_Op_Abs --
5073 ---------------------
5075 procedure Expand_N_Op_Abs (N : Node_Id) is
5076 Loc : constant Source_Ptr := Sloc (N);
5077 Expr : constant Node_Id := Right_Opnd (N);
5080 Unary_Op_Validity_Checks (N);
5082 -- Deal with software overflow checking
5084 if not Backend_Overflow_Checks_On_Target
5085 and then Is_Signed_Integer_Type (Etype (N))
5086 and then Do_Overflow_Check (N)
5088 -- The only case to worry about is when the argument is equal to the
5089 -- largest negative number, so what we do is to insert the check:
5091 -- [constraint_error when Expr = typ'Base'First]
5093 -- with the usual Duplicate_Subexpr use coding for expr
5096 Make_Raise_Constraint_Error (Loc,
5099 Left_Opnd => Duplicate_Subexpr (Expr),
5101 Make_Attribute_Reference (Loc,
5103 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
5104 Attribute_Name => Name_First)),
5105 Reason => CE_Overflow_Check_Failed));
5108 -- Vax floating-point types case
5110 if Vax_Float (Etype (N)) then
5111 Expand_Vax_Arith (N);
5113 end Expand_N_Op_Abs;
5115 ---------------------
5116 -- Expand_N_Op_Add --
5117 ---------------------
5119 procedure Expand_N_Op_Add (N : Node_Id) is
5120 Typ : constant Entity_Id := Etype (N);
5123 Binary_Op_Validity_Checks (N);
5125 -- N + 0 = 0 + N = N for integer types
5127 if Is_Integer_Type (Typ) then
5128 if Compile_Time_Known_Value (Right_Opnd (N))
5129 and then Expr_Value (Right_Opnd (N)) = Uint_0
5131 Rewrite (N, Left_Opnd (N));
5134 elsif Compile_Time_Known_Value (Left_Opnd (N))
5135 and then Expr_Value (Left_Opnd (N)) = Uint_0
5137 Rewrite (N, Right_Opnd (N));
5142 -- Arithmetic overflow checks for signed integer/fixed point types
5144 if Is_Signed_Integer_Type (Typ)
5145 or else Is_Fixed_Point_Type (Typ)
5147 Apply_Arithmetic_Overflow_Check (N);
5150 -- Vax floating-point types case
5152 elsif Vax_Float (Typ) then
5153 Expand_Vax_Arith (N);
5155 end Expand_N_Op_Add;
5157 ---------------------
5158 -- Expand_N_Op_And --
5159 ---------------------
5161 procedure Expand_N_Op_And (N : Node_Id) is
5162 Typ : constant Entity_Id := Etype (N);
5165 Binary_Op_Validity_Checks (N);
5167 if Is_Array_Type (Etype (N)) then
5168 Expand_Boolean_Operator (N);
5170 elsif Is_Boolean_Type (Etype (N)) then
5172 -- Replace AND by AND THEN if Short_Circuit_And_Or active and the
5173 -- type is standard Boolean (do not mess with AND that uses a non-
5174 -- standard Boolean type, because something strange is going on).
5176 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
5178 Make_And_Then (Sloc (N),
5179 Left_Opnd => Relocate_Node (Left_Opnd (N)),
5180 Right_Opnd => Relocate_Node (Right_Opnd (N))));
5181 Analyze_And_Resolve (N, Typ);
5183 -- Otherwise, adjust conditions
5186 Adjust_Condition (Left_Opnd (N));
5187 Adjust_Condition (Right_Opnd (N));
5188 Set_Etype (N, Standard_Boolean);
5189 Adjust_Result_Type (N, Typ);
5192 elsif Is_Intrinsic_Subprogram (Entity (N)) then
5193 Expand_Intrinsic_Call (N, Entity (N));
5196 end Expand_N_Op_And;
5198 ------------------------
5199 -- Expand_N_Op_Concat --
5200 ------------------------
5202 procedure Expand_N_Op_Concat (N : Node_Id) is
5204 -- List of operands to be concatenated
5207 -- Node which is to be replaced by the result of concatenating the nodes
5208 -- in the list Opnds.
5211 -- Ensure validity of both operands
5213 Binary_Op_Validity_Checks (N);
5215 -- If we are the left operand of a concatenation higher up the tree,
5216 -- then do nothing for now, since we want to deal with a series of
5217 -- concatenations as a unit.
5219 if Nkind (Parent (N)) = N_Op_Concat
5220 and then N = Left_Opnd (Parent (N))
5225 -- We get here with a concatenation whose left operand may be a
5226 -- concatenation itself with a consistent type. We need to process
5227 -- these concatenation operands from left to right, which means
5228 -- from the deepest node in the tree to the highest node.
5231 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
5232 Cnode := Left_Opnd (Cnode);
5235 -- Now Cnode is the deepest concatenation, and its parents are the
5236 -- concatenation nodes above, so now we process bottom up, doing the
5237 -- operations. We gather a string that is as long as possible up to five
5240 -- The outer loop runs more than once if more than one concatenation
5241 -- type is involved.
5244 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
5245 Set_Parent (Opnds, N);
5247 -- The inner loop gathers concatenation operands
5249 Inner : while Cnode /= N
5250 and then Base_Type (Etype (Cnode)) =
5251 Base_Type (Etype (Parent (Cnode)))
5253 Cnode := Parent (Cnode);
5254 Append (Right_Opnd (Cnode), Opnds);
5257 Expand_Concatenate (Cnode, Opnds);
5259 exit Outer when Cnode = N;
5260 Cnode := Parent (Cnode);
5262 end Expand_N_Op_Concat;
5264 ------------------------
5265 -- Expand_N_Op_Divide --
5266 ------------------------
5268 procedure Expand_N_Op_Divide (N : Node_Id) is
5269 Loc : constant Source_Ptr := Sloc (N);
5270 Lopnd : constant Node_Id := Left_Opnd (N);
5271 Ropnd : constant Node_Id := Right_Opnd (N);
5272 Ltyp : constant Entity_Id := Etype (Lopnd);
5273 Rtyp : constant Entity_Id := Etype (Ropnd);
5274 Typ : Entity_Id := Etype (N);
5275 Rknow : constant Boolean := Is_Integer_Type (Typ)
5277 Compile_Time_Known_Value (Ropnd);
5281 Binary_Op_Validity_Checks (N);
5284 Rval := Expr_Value (Ropnd);
5287 -- N / 1 = N for integer types
5289 if Rknow and then Rval = Uint_1 then
5294 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
5295 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5296 -- operand is an unsigned integer, as required for this to work.
5298 if Nkind (Ropnd) = N_Op_Expon
5299 and then Is_Power_Of_2_For_Shift (Ropnd)
5301 -- We cannot do this transformation in configurable run time mode if we
5302 -- have 64-bit integers and long shifts are not available.
5306 or else Support_Long_Shifts_On_Target)
5309 Make_Op_Shift_Right (Loc,
5312 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
5313 Analyze_And_Resolve (N, Typ);
5317 -- Do required fixup of universal fixed operation
5319 if Typ = Universal_Fixed then
5320 Fixup_Universal_Fixed_Operation (N);
5324 -- Divisions with fixed-point results
5326 if Is_Fixed_Point_Type (Typ) then
5328 -- No special processing if Treat_Fixed_As_Integer is set, since
5329 -- from a semantic point of view such operations are simply integer
5330 -- operations and will be treated that way.
5332 if not Treat_Fixed_As_Integer (N) then
5333 if Is_Integer_Type (Rtyp) then
5334 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
5336 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
5340 -- Other cases of division of fixed-point operands. Again we exclude the
5341 -- case where Treat_Fixed_As_Integer is set.
5343 elsif (Is_Fixed_Point_Type (Ltyp) or else
5344 Is_Fixed_Point_Type (Rtyp))
5345 and then not Treat_Fixed_As_Integer (N)
5347 if Is_Integer_Type (Typ) then
5348 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
5350 pragma Assert (Is_Floating_Point_Type (Typ));
5351 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
5354 -- Mixed-mode operations can appear in a non-static universal context,
5355 -- in which case the integer argument must be converted explicitly.
5357 elsif Typ = Universal_Real
5358 and then Is_Integer_Type (Rtyp)
5361 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
5363 Analyze_And_Resolve (Ropnd, Universal_Real);
5365 elsif Typ = Universal_Real
5366 and then Is_Integer_Type (Ltyp)
5369 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
5371 Analyze_And_Resolve (Lopnd, Universal_Real);
5373 -- Non-fixed point cases, do integer zero divide and overflow checks
5375 elsif Is_Integer_Type (Typ) then
5376 Apply_Divide_Check (N);
5378 -- Check for 64-bit division available, or long shifts if the divisor
5379 -- is a small power of 2 (since such divides will be converted into
5382 if Esize (Ltyp) > 32
5383 and then not Support_64_Bit_Divides_On_Target
5386 or else not Support_Long_Shifts_On_Target
5387 or else (Rval /= Uint_2 and then
5388 Rval /= Uint_4 and then
5389 Rval /= Uint_8 and then
5390 Rval /= Uint_16 and then
5391 Rval /= Uint_32 and then
5394 Error_Msg_CRT ("64-bit division", N);
5397 -- Deal with Vax_Float
5399 elsif Vax_Float (Typ) then
5400 Expand_Vax_Arith (N);
5403 end Expand_N_Op_Divide;
5405 --------------------
5406 -- Expand_N_Op_Eq --
5407 --------------------
5409 procedure Expand_N_Op_Eq (N : Node_Id) is
5410 Loc : constant Source_Ptr := Sloc (N);
5411 Typ : constant Entity_Id := Etype (N);
5412 Lhs : constant Node_Id := Left_Opnd (N);
5413 Rhs : constant Node_Id := Right_Opnd (N);
5414 Bodies : constant List_Id := New_List;
5415 A_Typ : constant Entity_Id := Etype (Lhs);
5417 Typl : Entity_Id := A_Typ;
5418 Op_Name : Entity_Id;
5421 procedure Build_Equality_Call (Eq : Entity_Id);
5422 -- If a constructed equality exists for the type or for its parent,
5423 -- build and analyze call, adding conversions if the operation is
5426 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
5427 -- Determines whether a type has a subcomponent of an unconstrained
5428 -- Unchecked_Union subtype. Typ is a record type.
5430 -------------------------
5431 -- Build_Equality_Call --
5432 -------------------------
5434 procedure Build_Equality_Call (Eq : Entity_Id) is
5435 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
5436 L_Exp : Node_Id := Relocate_Node (Lhs);
5437 R_Exp : Node_Id := Relocate_Node (Rhs);
5440 if Base_Type (Op_Type) /= Base_Type (A_Typ)
5441 and then not Is_Class_Wide_Type (A_Typ)
5443 L_Exp := OK_Convert_To (Op_Type, L_Exp);
5444 R_Exp := OK_Convert_To (Op_Type, R_Exp);
5447 -- If we have an Unchecked_Union, we need to add the inferred
5448 -- discriminant values as actuals in the function call. At this
5449 -- point, the expansion has determined that both operands have
5450 -- inferable discriminants.
5452 if Is_Unchecked_Union (Op_Type) then
5454 Lhs_Type : constant Node_Id := Etype (L_Exp);
5455 Rhs_Type : constant Node_Id := Etype (R_Exp);
5456 Lhs_Discr_Val : Node_Id;
5457 Rhs_Discr_Val : Node_Id;
5460 -- Per-object constrained selected components require special
5461 -- attention. If the enclosing scope of the component is an
5462 -- Unchecked_Union, we cannot reference its discriminants
5463 -- directly. This is why we use the two extra parameters of
5464 -- the equality function of the enclosing Unchecked_Union.
5466 -- type UU_Type (Discr : Integer := 0) is
5469 -- pragma Unchecked_Union (UU_Type);
5471 -- 1. Unchecked_Union enclosing record:
5473 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
5475 -- Comp : UU_Type (Discr);
5477 -- end Enclosing_UU_Type;
5478 -- pragma Unchecked_Union (Enclosing_UU_Type);
5480 -- Obj1 : Enclosing_UU_Type;
5481 -- Obj2 : Enclosing_UU_Type (1);
5483 -- [. . .] Obj1 = Obj2 [. . .]
5487 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
5489 -- A and B are the formal parameters of the equality function
5490 -- of Enclosing_UU_Type. The function always has two extra
5491 -- formals to capture the inferred discriminant values.
5493 -- 2. Non-Unchecked_Union enclosing record:
5496 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
5499 -- Comp : UU_Type (Discr);
5501 -- end Enclosing_Non_UU_Type;
5503 -- Obj1 : Enclosing_Non_UU_Type;
5504 -- Obj2 : Enclosing_Non_UU_Type (1);
5506 -- ... Obj1 = Obj2 ...
5510 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
5511 -- obj1.discr, obj2.discr)) then
5513 -- In this case we can directly reference the discriminants of
5514 -- the enclosing record.
5518 if Nkind (Lhs) = N_Selected_Component
5519 and then Has_Per_Object_Constraint
5520 (Entity (Selector_Name (Lhs)))
5522 -- Enclosing record is an Unchecked_Union, use formal A
5524 if Is_Unchecked_Union (Scope
5525 (Entity (Selector_Name (Lhs))))
5528 Make_Identifier (Loc,
5531 -- Enclosing record is of a non-Unchecked_Union type, it is
5532 -- possible to reference the discriminant.
5536 Make_Selected_Component (Loc,
5537 Prefix => Prefix (Lhs),
5540 (Get_Discriminant_Value
5541 (First_Discriminant (Lhs_Type),
5543 Stored_Constraint (Lhs_Type))));
5546 -- Comment needed here ???
5549 -- Infer the discriminant value
5553 (Get_Discriminant_Value
5554 (First_Discriminant (Lhs_Type),
5556 Stored_Constraint (Lhs_Type)));
5561 if Nkind (Rhs) = N_Selected_Component
5562 and then Has_Per_Object_Constraint
5563 (Entity (Selector_Name (Rhs)))
5565 if Is_Unchecked_Union
5566 (Scope (Entity (Selector_Name (Rhs))))
5569 Make_Identifier (Loc,
5574 Make_Selected_Component (Loc,
5575 Prefix => Prefix (Rhs),
5577 New_Copy (Get_Discriminant_Value (
5578 First_Discriminant (Rhs_Type),
5580 Stored_Constraint (Rhs_Type))));
5585 New_Copy (Get_Discriminant_Value (
5586 First_Discriminant (Rhs_Type),
5588 Stored_Constraint (Rhs_Type)));
5593 Make_Function_Call (Loc,
5594 Name => New_Reference_To (Eq, Loc),
5595 Parameter_Associations => New_List (
5602 -- Normal case, not an unchecked union
5606 Make_Function_Call (Loc,
5607 Name => New_Reference_To (Eq, Loc),
5608 Parameter_Associations => New_List (L_Exp, R_Exp)));
5611 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5612 end Build_Equality_Call;
5614 ------------------------------------
5615 -- Has_Unconstrained_UU_Component --
5616 ------------------------------------
5618 function Has_Unconstrained_UU_Component
5619 (Typ : Node_Id) return Boolean
5621 Tdef : constant Node_Id :=
5622 Type_Definition (Declaration_Node (Base_Type (Typ)));
5626 function Component_Is_Unconstrained_UU
5627 (Comp : Node_Id) return Boolean;
5628 -- Determines whether the subtype of the component is an
5629 -- unconstrained Unchecked_Union.
5631 function Variant_Is_Unconstrained_UU
5632 (Variant : Node_Id) return Boolean;
5633 -- Determines whether a component of the variant has an unconstrained
5634 -- Unchecked_Union subtype.
5636 -----------------------------------
5637 -- Component_Is_Unconstrained_UU --
5638 -----------------------------------
5640 function Component_Is_Unconstrained_UU
5641 (Comp : Node_Id) return Boolean
5644 if Nkind (Comp) /= N_Component_Declaration then
5649 Sindic : constant Node_Id :=
5650 Subtype_Indication (Component_Definition (Comp));
5653 -- Unconstrained nominal type. In the case of a constraint
5654 -- present, the node kind would have been N_Subtype_Indication.
5656 if Nkind (Sindic) = N_Identifier then
5657 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
5662 end Component_Is_Unconstrained_UU;
5664 ---------------------------------
5665 -- Variant_Is_Unconstrained_UU --
5666 ---------------------------------
5668 function Variant_Is_Unconstrained_UU
5669 (Variant : Node_Id) return Boolean
5671 Clist : constant Node_Id := Component_List (Variant);
5674 if Is_Empty_List (Component_Items (Clist)) then
5678 -- We only need to test one component
5681 Comp : Node_Id := First (Component_Items (Clist));
5684 while Present (Comp) loop
5685 if Component_Is_Unconstrained_UU (Comp) then
5693 -- None of the components withing the variant were of
5694 -- unconstrained Unchecked_Union type.
5697 end Variant_Is_Unconstrained_UU;
5699 -- Start of processing for Has_Unconstrained_UU_Component
5702 if Null_Present (Tdef) then
5706 Clist := Component_List (Tdef);
5707 Vpart := Variant_Part (Clist);
5709 -- Inspect available components
5711 if Present (Component_Items (Clist)) then
5713 Comp : Node_Id := First (Component_Items (Clist));
5716 while Present (Comp) loop
5718 -- One component is sufficient
5720 if Component_Is_Unconstrained_UU (Comp) then
5729 -- Inspect available components withing variants
5731 if Present (Vpart) then
5733 Variant : Node_Id := First (Variants (Vpart));
5736 while Present (Variant) loop
5738 -- One component within a variant is sufficient
5740 if Variant_Is_Unconstrained_UU (Variant) then
5749 -- Neither the available components, nor the components inside the
5750 -- variant parts were of an unconstrained Unchecked_Union subtype.
5753 end Has_Unconstrained_UU_Component;
5755 -- Start of processing for Expand_N_Op_Eq
5758 Binary_Op_Validity_Checks (N);
5760 if Ekind (Typl) = E_Private_Type then
5761 Typl := Underlying_Type (Typl);
5762 elsif Ekind (Typl) = E_Private_Subtype then
5763 Typl := Underlying_Type (Base_Type (Typl));
5768 -- It may happen in error situations that the underlying type is not
5769 -- set. The error will be detected later, here we just defend the
5776 Typl := Base_Type (Typl);
5778 -- Boolean types (requiring handling of non-standard case)
5780 if Is_Boolean_Type (Typl) then
5781 Adjust_Condition (Left_Opnd (N));
5782 Adjust_Condition (Right_Opnd (N));
5783 Set_Etype (N, Standard_Boolean);
5784 Adjust_Result_Type (N, Typ);
5788 elsif Is_Array_Type (Typl) then
5790 -- If we are doing full validity checking, and it is possible for the
5791 -- array elements to be invalid then expand out array comparisons to
5792 -- make sure that we check the array elements.
5794 if Validity_Check_Operands
5795 and then not Is_Known_Valid (Component_Type (Typl))
5798 Save_Force_Validity_Checks : constant Boolean :=
5799 Force_Validity_Checks;
5801 Force_Validity_Checks := True;
5803 Expand_Array_Equality
5805 Relocate_Node (Lhs),
5806 Relocate_Node (Rhs),
5809 Insert_Actions (N, Bodies);
5810 Analyze_And_Resolve (N, Standard_Boolean);
5811 Force_Validity_Checks := Save_Force_Validity_Checks;
5814 -- Packed case where both operands are known aligned
5816 elsif Is_Bit_Packed_Array (Typl)
5817 and then not Is_Possibly_Unaligned_Object (Lhs)
5818 and then not Is_Possibly_Unaligned_Object (Rhs)
5820 Expand_Packed_Eq (N);
5822 -- Where the component type is elementary we can use a block bit
5823 -- comparison (if supported on the target) exception in the case
5824 -- of floating-point (negative zero issues require element by
5825 -- element comparison), and atomic types (where we must be sure
5826 -- to load elements independently) and possibly unaligned arrays.
5828 elsif Is_Elementary_Type (Component_Type (Typl))
5829 and then not Is_Floating_Point_Type (Component_Type (Typl))
5830 and then not Is_Atomic (Component_Type (Typl))
5831 and then not Is_Possibly_Unaligned_Object (Lhs)
5832 and then not Is_Possibly_Unaligned_Object (Rhs)
5833 and then Support_Composite_Compare_On_Target
5837 -- For composite and floating-point cases, expand equality loop to
5838 -- make sure of using proper comparisons for tagged types, and
5839 -- correctly handling the floating-point case.
5843 Expand_Array_Equality
5845 Relocate_Node (Lhs),
5846 Relocate_Node (Rhs),
5849 Insert_Actions (N, Bodies, Suppress => All_Checks);
5850 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5855 elsif Is_Record_Type (Typl) then
5857 -- For tagged types, use the primitive "="
5859 if Is_Tagged_Type (Typl) then
5861 -- No need to do anything else compiling under restriction
5862 -- No_Dispatching_Calls. During the semantic analysis we
5863 -- already notified such violation.
5865 if Restriction_Active (No_Dispatching_Calls) then
5869 -- If this is derived from an untagged private type completed with
5870 -- a tagged type, it does not have a full view, so we use the
5871 -- primitive operations of the private type. This check should no
5872 -- longer be necessary when these types get their full views???
5874 if Is_Private_Type (A_Typ)
5875 and then not Is_Tagged_Type (A_Typ)
5876 and then Is_Derived_Type (A_Typ)
5877 and then No (Full_View (A_Typ))
5879 -- Search for equality operation, checking that the operands
5880 -- have the same type. Note that we must find a matching entry,
5881 -- or something is very wrong!
5883 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
5885 while Present (Prim) loop
5886 exit when Chars (Node (Prim)) = Name_Op_Eq
5887 and then Etype (First_Formal (Node (Prim))) =
5888 Etype (Next_Formal (First_Formal (Node (Prim))))
5890 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
5895 pragma Assert (Present (Prim));
5896 Op_Name := Node (Prim);
5898 -- Find the type's predefined equality or an overriding
5899 -- user- defined equality. The reason for not simply calling
5900 -- Find_Prim_Op here is that there may be a user-defined
5901 -- overloaded equality op that precedes the equality that we want,
5902 -- so we have to explicitly search (e.g., there could be an
5903 -- equality with two different parameter types).
5906 if Is_Class_Wide_Type (Typl) then
5907 Typl := Root_Type (Typl);
5910 Prim := First_Elmt (Primitive_Operations (Typl));
5911 while Present (Prim) loop
5912 exit when Chars (Node (Prim)) = Name_Op_Eq
5913 and then Etype (First_Formal (Node (Prim))) =
5914 Etype (Next_Formal (First_Formal (Node (Prim))))
5916 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
5921 pragma Assert (Present (Prim));
5922 Op_Name := Node (Prim);
5925 Build_Equality_Call (Op_Name);
5927 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
5928 -- predefined equality operator for a type which has a subcomponent
5929 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
5931 elsif Has_Unconstrained_UU_Component (Typl) then
5933 Make_Raise_Program_Error (Loc,
5934 Reason => PE_Unchecked_Union_Restriction));
5936 -- Prevent Gigi from generating incorrect code by rewriting the
5937 -- equality as a standard False.
5940 New_Occurrence_Of (Standard_False, Loc));
5942 elsif Is_Unchecked_Union (Typl) then
5944 -- If we can infer the discriminants of the operands, we make a
5945 -- call to the TSS equality function.
5947 if Has_Inferable_Discriminants (Lhs)
5949 Has_Inferable_Discriminants (Rhs)
5952 (TSS (Root_Type (Typl), TSS_Composite_Equality));
5955 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
5956 -- the predefined equality operator for an Unchecked_Union type
5957 -- if either of the operands lack inferable discriminants.
5960 Make_Raise_Program_Error (Loc,
5961 Reason => PE_Unchecked_Union_Restriction));
5963 -- Prevent Gigi from generating incorrect code by rewriting
5964 -- the equality as a standard False.
5967 New_Occurrence_Of (Standard_False, Loc));
5971 -- If a type support function is present (for complex cases), use it
5973 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
5975 (TSS (Root_Type (Typl), TSS_Composite_Equality));
5977 -- Otherwise expand the component by component equality. Note that
5978 -- we never use block-bit comparisons for records, because of the
5979 -- problems with gaps. The backend will often be able to recombine
5980 -- the separate comparisons that we generate here.
5983 Remove_Side_Effects (Lhs);
5984 Remove_Side_Effects (Rhs);
5986 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
5988 Insert_Actions (N, Bodies, Suppress => All_Checks);
5989 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5993 -- Test if result is known at compile time
5995 Rewrite_Comparison (N);
5997 -- If we still have comparison for Vax_Float, process it
5999 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
6000 Expand_Vax_Comparison (N);
6005 -----------------------
6006 -- Expand_N_Op_Expon --
6007 -----------------------
6009 procedure Expand_N_Op_Expon (N : Node_Id) is
6010 Loc : constant Source_Ptr := Sloc (N);
6011 Typ : constant Entity_Id := Etype (N);
6012 Rtyp : constant Entity_Id := Root_Type (Typ);
6013 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
6014 Bastyp : constant Node_Id := Etype (Base);
6015 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
6016 Exptyp : constant Entity_Id := Etype (Exp);
6017 Ovflo : constant Boolean := Do_Overflow_Check (N);
6026 Binary_Op_Validity_Checks (N);
6028 -- If either operand is of a private type, then we have the use of an
6029 -- intrinsic operator, and we get rid of the privateness, by using root
6030 -- types of underlying types for the actual operation. Otherwise the
6031 -- private types will cause trouble if we expand multiplications or
6032 -- shifts etc. We also do this transformation if the result type is
6033 -- different from the base type.
6035 if Is_Private_Type (Etype (Base))
6037 Is_Private_Type (Typ)
6039 Is_Private_Type (Exptyp)
6041 Rtyp /= Root_Type (Bastyp)
6044 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
6045 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
6049 Unchecked_Convert_To (Typ,
6051 Left_Opnd => Unchecked_Convert_To (Bt, Base),
6052 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
6053 Analyze_And_Resolve (N, Typ);
6058 -- Test for case of known right argument
6060 if Compile_Time_Known_Value (Exp) then
6061 Expv := Expr_Value (Exp);
6063 -- We only fold small non-negative exponents. You might think we
6064 -- could fold small negative exponents for the real case, but we
6065 -- can't because we are required to raise Constraint_Error for
6066 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
6067 -- See ACVC test C4A012B.
6069 if Expv >= 0 and then Expv <= 4 then
6071 -- X ** 0 = 1 (or 1.0)
6075 -- Call Remove_Side_Effects to ensure that any side effects
6076 -- in the ignored left operand (in particular function calls
6077 -- to user defined functions) are properly executed.
6079 Remove_Side_Effects (Base);
6081 if Ekind (Typ) in Integer_Kind then
6082 Xnode := Make_Integer_Literal (Loc, Intval => 1);
6084 Xnode := Make_Real_Literal (Loc, Ureal_1);
6096 Make_Op_Multiply (Loc,
6097 Left_Opnd => Duplicate_Subexpr (Base),
6098 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6100 -- X ** 3 = X * X * X
6104 Make_Op_Multiply (Loc,
6106 Make_Op_Multiply (Loc,
6107 Left_Opnd => Duplicate_Subexpr (Base),
6108 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
6109 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6112 -- En : constant base'type := base * base;
6117 Temp := Make_Temporary (Loc, 'E', Base);
6119 Insert_Actions (N, New_List (
6120 Make_Object_Declaration (Loc,
6121 Defining_Identifier => Temp,
6122 Constant_Present => True,
6123 Object_Definition => New_Reference_To (Typ, Loc),
6125 Make_Op_Multiply (Loc,
6126 Left_Opnd => Duplicate_Subexpr (Base),
6127 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
6130 Make_Op_Multiply (Loc,
6131 Left_Opnd => New_Reference_To (Temp, Loc),
6132 Right_Opnd => New_Reference_To (Temp, Loc));
6136 Analyze_And_Resolve (N, Typ);
6141 -- Case of (2 ** expression) appearing as an argument of an integer
6142 -- multiplication, or as the right argument of a division of a non-
6143 -- negative integer. In such cases we leave the node untouched, setting
6144 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
6145 -- of the higher level node converts it into a shift.
6147 -- Another case is 2 ** N in any other context. We simply convert
6148 -- this to 1 * 2 ** N, and then the above transformation applies.
6150 -- Note: this transformation is not applicable for a modular type with
6151 -- a non-binary modulus in the multiplication case, since we get a wrong
6152 -- result if the shift causes an overflow before the modular reduction.
6154 if Nkind (Base) = N_Integer_Literal
6155 and then Intval (Base) = 2
6156 and then Is_Integer_Type (Root_Type (Exptyp))
6157 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
6158 and then Is_Unsigned_Type (Exptyp)
6161 -- First the multiply and divide cases
6163 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
6165 P : constant Node_Id := Parent (N);
6166 L : constant Node_Id := Left_Opnd (P);
6167 R : constant Node_Id := Right_Opnd (P);
6170 if (Nkind (P) = N_Op_Multiply
6171 and then not Non_Binary_Modulus (Typ)
6173 ((Is_Integer_Type (Etype (L)) and then R = N)
6175 (Is_Integer_Type (Etype (R)) and then L = N))
6176 and then not Do_Overflow_Check (P))
6178 (Nkind (P) = N_Op_Divide
6179 and then Is_Integer_Type (Etype (L))
6180 and then Is_Unsigned_Type (Etype (L))
6182 and then not Do_Overflow_Check (P))
6184 Set_Is_Power_Of_2_For_Shift (N);
6189 -- Now the other cases
6191 elsif not Non_Binary_Modulus (Typ) then
6193 Make_Op_Multiply (Loc,
6194 Left_Opnd => Make_Integer_Literal (Loc, 1),
6195 Right_Opnd => Relocate_Node (N)));
6196 Analyze_And_Resolve (N, Typ);
6201 -- Fall through if exponentiation must be done using a runtime routine
6203 -- First deal with modular case
6205 if Is_Modular_Integer_Type (Rtyp) then
6207 -- Non-binary case, we call the special exponentiation routine for
6208 -- the non-binary case, converting the argument to Long_Long_Integer
6209 -- and passing the modulus value. Then the result is converted back
6210 -- to the base type.
6212 if Non_Binary_Modulus (Rtyp) then
6215 Make_Function_Call (Loc,
6216 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
6217 Parameter_Associations => New_List (
6218 Convert_To (Standard_Integer, Base),
6219 Make_Integer_Literal (Loc, Modulus (Rtyp)),
6222 -- Binary case, in this case, we call one of two routines, either the
6223 -- unsigned integer case, or the unsigned long long integer case,
6224 -- with a final "and" operation to do the required mod.
6227 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
6228 Ent := RTE (RE_Exp_Unsigned);
6230 Ent := RTE (RE_Exp_Long_Long_Unsigned);
6237 Make_Function_Call (Loc,
6238 Name => New_Reference_To (Ent, Loc),
6239 Parameter_Associations => New_List (
6240 Convert_To (Etype (First_Formal (Ent)), Base),
6243 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
6247 -- Common exit point for modular type case
6249 Analyze_And_Resolve (N, Typ);
6252 -- Signed integer cases, done using either Integer or Long_Long_Integer.
6253 -- It is not worth having routines for Short_[Short_]Integer, since for
6254 -- most machines it would not help, and it would generate more code that
6255 -- might need certification when a certified run time is required.
6257 -- In the integer cases, we have two routines, one for when overflow
6258 -- checks are required, and one when they are not required, since there
6259 -- is a real gain in omitting checks on many machines.
6261 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
6262 or else (Rtyp = Base_Type (Standard_Long_Integer)
6264 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
6265 or else (Rtyp = Universal_Integer)
6267 Etyp := Standard_Long_Long_Integer;
6270 Rent := RE_Exp_Long_Long_Integer;
6272 Rent := RE_Exn_Long_Long_Integer;
6275 elsif Is_Signed_Integer_Type (Rtyp) then
6276 Etyp := Standard_Integer;
6279 Rent := RE_Exp_Integer;
6281 Rent := RE_Exn_Integer;
6284 -- Floating-point cases, always done using Long_Long_Float. We do not
6285 -- need separate routines for the overflow case here, since in the case
6286 -- of floating-point, we generate infinities anyway as a rule (either
6287 -- that or we automatically trap overflow), and if there is an infinity
6288 -- generated and a range check is required, the check will fail anyway.
6291 pragma Assert (Is_Floating_Point_Type (Rtyp));
6292 Etyp := Standard_Long_Long_Float;
6293 Rent := RE_Exn_Long_Long_Float;
6296 -- Common processing for integer cases and floating-point cases.
6297 -- If we are in the right type, we can call runtime routine directly
6300 and then Rtyp /= Universal_Integer
6301 and then Rtyp /= Universal_Real
6304 Make_Function_Call (Loc,
6305 Name => New_Reference_To (RTE (Rent), Loc),
6306 Parameter_Associations => New_List (Base, Exp)));
6308 -- Otherwise we have to introduce conversions (conversions are also
6309 -- required in the universal cases, since the runtime routine is
6310 -- typed using one of the standard types).
6315 Make_Function_Call (Loc,
6316 Name => New_Reference_To (RTE (Rent), Loc),
6317 Parameter_Associations => New_List (
6318 Convert_To (Etyp, Base),
6322 Analyze_And_Resolve (N, Typ);
6326 when RE_Not_Available =>
6328 end Expand_N_Op_Expon;
6330 --------------------
6331 -- Expand_N_Op_Ge --
6332 --------------------
6334 procedure Expand_N_Op_Ge (N : Node_Id) is
6335 Typ : constant Entity_Id := Etype (N);
6336 Op1 : constant Node_Id := Left_Opnd (N);
6337 Op2 : constant Node_Id := Right_Opnd (N);
6338 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6341 Binary_Op_Validity_Checks (N);
6343 if Is_Array_Type (Typ1) then
6344 Expand_Array_Comparison (N);
6348 if Is_Boolean_Type (Typ1) then
6349 Adjust_Condition (Op1);
6350 Adjust_Condition (Op2);
6351 Set_Etype (N, Standard_Boolean);
6352 Adjust_Result_Type (N, Typ);
6355 Rewrite_Comparison (N);
6357 -- If we still have comparison, and Vax_Float type, process it
6359 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6360 Expand_Vax_Comparison (N);
6365 --------------------
6366 -- Expand_N_Op_Gt --
6367 --------------------
6369 procedure Expand_N_Op_Gt (N : Node_Id) is
6370 Typ : constant Entity_Id := Etype (N);
6371 Op1 : constant Node_Id := Left_Opnd (N);
6372 Op2 : constant Node_Id := Right_Opnd (N);
6373 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6376 Binary_Op_Validity_Checks (N);
6378 if Is_Array_Type (Typ1) then
6379 Expand_Array_Comparison (N);
6383 if Is_Boolean_Type (Typ1) then
6384 Adjust_Condition (Op1);
6385 Adjust_Condition (Op2);
6386 Set_Etype (N, Standard_Boolean);
6387 Adjust_Result_Type (N, Typ);
6390 Rewrite_Comparison (N);
6392 -- If we still have comparison, and Vax_Float type, process it
6394 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6395 Expand_Vax_Comparison (N);
6400 --------------------
6401 -- Expand_N_Op_Le --
6402 --------------------
6404 procedure Expand_N_Op_Le (N : Node_Id) is
6405 Typ : constant Entity_Id := Etype (N);
6406 Op1 : constant Node_Id := Left_Opnd (N);
6407 Op2 : constant Node_Id := Right_Opnd (N);
6408 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6411 Binary_Op_Validity_Checks (N);
6413 if Is_Array_Type (Typ1) then
6414 Expand_Array_Comparison (N);
6418 if Is_Boolean_Type (Typ1) then
6419 Adjust_Condition (Op1);
6420 Adjust_Condition (Op2);
6421 Set_Etype (N, Standard_Boolean);
6422 Adjust_Result_Type (N, Typ);
6425 Rewrite_Comparison (N);
6427 -- If we still have comparison, and Vax_Float type, process it
6429 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6430 Expand_Vax_Comparison (N);
6435 --------------------
6436 -- Expand_N_Op_Lt --
6437 --------------------
6439 procedure Expand_N_Op_Lt (N : Node_Id) is
6440 Typ : constant Entity_Id := Etype (N);
6441 Op1 : constant Node_Id := Left_Opnd (N);
6442 Op2 : constant Node_Id := Right_Opnd (N);
6443 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6446 Binary_Op_Validity_Checks (N);
6448 if Is_Array_Type (Typ1) then
6449 Expand_Array_Comparison (N);
6453 if Is_Boolean_Type (Typ1) then
6454 Adjust_Condition (Op1);
6455 Adjust_Condition (Op2);
6456 Set_Etype (N, Standard_Boolean);
6457 Adjust_Result_Type (N, Typ);
6460 Rewrite_Comparison (N);
6462 -- If we still have comparison, and Vax_Float type, process it
6464 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6465 Expand_Vax_Comparison (N);
6470 -----------------------
6471 -- Expand_N_Op_Minus --
6472 -----------------------
6474 procedure Expand_N_Op_Minus (N : Node_Id) is
6475 Loc : constant Source_Ptr := Sloc (N);
6476 Typ : constant Entity_Id := Etype (N);
6479 Unary_Op_Validity_Checks (N);
6481 if not Backend_Overflow_Checks_On_Target
6482 and then Is_Signed_Integer_Type (Etype (N))
6483 and then Do_Overflow_Check (N)
6485 -- Software overflow checking expands -expr into (0 - expr)
6488 Make_Op_Subtract (Loc,
6489 Left_Opnd => Make_Integer_Literal (Loc, 0),
6490 Right_Opnd => Right_Opnd (N)));
6492 Analyze_And_Resolve (N, Typ);
6494 -- Vax floating-point types case
6496 elsif Vax_Float (Etype (N)) then
6497 Expand_Vax_Arith (N);
6499 end Expand_N_Op_Minus;
6501 ---------------------
6502 -- Expand_N_Op_Mod --
6503 ---------------------
6505 procedure Expand_N_Op_Mod (N : Node_Id) is
6506 Loc : constant Source_Ptr := Sloc (N);
6507 Typ : constant Entity_Id := Etype (N);
6508 Left : constant Node_Id := Left_Opnd (N);
6509 Right : constant Node_Id := Right_Opnd (N);
6510 DOC : constant Boolean := Do_Overflow_Check (N);
6511 DDC : constant Boolean := Do_Division_Check (N);
6521 pragma Warnings (Off, Lhi);
6524 Binary_Op_Validity_Checks (N);
6526 Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
6527 Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
6529 -- Convert mod to rem if operands are known non-negative. We do this
6530 -- since it is quite likely that this will improve the quality of code,
6531 -- (the operation now corresponds to the hardware remainder), and it
6532 -- does not seem likely that it could be harmful.
6534 if LOK and then Llo >= 0
6536 ROK and then Rlo >= 0
6539 Make_Op_Rem (Sloc (N),
6540 Left_Opnd => Left_Opnd (N),
6541 Right_Opnd => Right_Opnd (N)));
6543 -- Instead of reanalyzing the node we do the analysis manually. This
6544 -- avoids anomalies when the replacement is done in an instance and
6545 -- is epsilon more efficient.
6547 Set_Entity (N, Standard_Entity (S_Op_Rem));
6549 Set_Do_Overflow_Check (N, DOC);
6550 Set_Do_Division_Check (N, DDC);
6551 Expand_N_Op_Rem (N);
6554 -- Otherwise, normal mod processing
6557 if Is_Integer_Type (Etype (N)) then
6558 Apply_Divide_Check (N);
6561 -- Apply optimization x mod 1 = 0. We don't really need that with
6562 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
6563 -- certainly harmless.
6565 if Is_Integer_Type (Etype (N))
6566 and then Compile_Time_Known_Value (Right)
6567 and then Expr_Value (Right) = Uint_1
6569 -- Call Remove_Side_Effects to ensure that any side effects in
6570 -- the ignored left operand (in particular function calls to
6571 -- user defined functions) are properly executed.
6573 Remove_Side_Effects (Left);
6575 Rewrite (N, Make_Integer_Literal (Loc, 0));
6576 Analyze_And_Resolve (N, Typ);
6580 -- Deal with annoying case of largest negative number remainder
6581 -- minus one. Gigi does not handle this case correctly, because
6582 -- it generates a divide instruction which may trap in this case.
6584 -- In fact the check is quite easy, if the right operand is -1, then
6585 -- the mod value is always 0, and we can just ignore the left operand
6586 -- completely in this case.
6588 -- The operand type may be private (e.g. in the expansion of an
6589 -- intrinsic operation) so we must use the underlying type to get the
6590 -- bounds, and convert the literals explicitly.
6594 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
6596 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
6598 ((not LOK) or else (Llo = LLB))
6601 Make_Conditional_Expression (Loc,
6602 Expressions => New_List (
6604 Left_Opnd => Duplicate_Subexpr (Right),
6606 Unchecked_Convert_To (Typ,
6607 Make_Integer_Literal (Loc, -1))),
6608 Unchecked_Convert_To (Typ,
6609 Make_Integer_Literal (Loc, Uint_0)),
6610 Relocate_Node (N))));
6612 Set_Analyzed (Next (Next (First (Expressions (N)))));
6613 Analyze_And_Resolve (N, Typ);
6616 end Expand_N_Op_Mod;
6618 --------------------------
6619 -- Expand_N_Op_Multiply --
6620 --------------------------
6622 procedure Expand_N_Op_Multiply (N : Node_Id) is
6623 Loc : constant Source_Ptr := Sloc (N);
6624 Lop : constant Node_Id := Left_Opnd (N);
6625 Rop : constant Node_Id := Right_Opnd (N);
6627 Lp2 : constant Boolean :=
6628 Nkind (Lop) = N_Op_Expon
6629 and then Is_Power_Of_2_For_Shift (Lop);
6631 Rp2 : constant Boolean :=
6632 Nkind (Rop) = N_Op_Expon
6633 and then Is_Power_Of_2_For_Shift (Rop);
6635 Ltyp : constant Entity_Id := Etype (Lop);
6636 Rtyp : constant Entity_Id := Etype (Rop);
6637 Typ : Entity_Id := Etype (N);
6640 Binary_Op_Validity_Checks (N);
6642 -- Special optimizations for integer types
6644 if Is_Integer_Type (Typ) then
6646 -- N * 0 = 0 for integer types
6648 if Compile_Time_Known_Value (Rop)
6649 and then Expr_Value (Rop) = Uint_0
6651 -- Call Remove_Side_Effects to ensure that any side effects in
6652 -- the ignored left operand (in particular function calls to
6653 -- user defined functions) are properly executed.
6655 Remove_Side_Effects (Lop);
6657 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6658 Analyze_And_Resolve (N, Typ);
6662 -- Similar handling for 0 * N = 0
6664 if Compile_Time_Known_Value (Lop)
6665 and then Expr_Value (Lop) = Uint_0
6667 Remove_Side_Effects (Rop);
6668 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6669 Analyze_And_Resolve (N, Typ);
6673 -- N * 1 = 1 * N = N for integer types
6675 -- This optimisation is not done if we are going to
6676 -- rewrite the product 1 * 2 ** N to a shift.
6678 if Compile_Time_Known_Value (Rop)
6679 and then Expr_Value (Rop) = Uint_1
6685 elsif Compile_Time_Known_Value (Lop)
6686 and then Expr_Value (Lop) = Uint_1
6694 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
6695 -- Is_Power_Of_2_For_Shift is set means that we know that our left
6696 -- operand is an integer, as required for this to work.
6701 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
6705 Left_Opnd => Make_Integer_Literal (Loc, 2),
6708 Left_Opnd => Right_Opnd (Lop),
6709 Right_Opnd => Right_Opnd (Rop))));
6710 Analyze_And_Resolve (N, Typ);
6715 Make_Op_Shift_Left (Loc,
6718 Convert_To (Standard_Natural, Right_Opnd (Rop))));
6719 Analyze_And_Resolve (N, Typ);
6723 -- Same processing for the operands the other way round
6727 Make_Op_Shift_Left (Loc,
6730 Convert_To (Standard_Natural, Right_Opnd (Lop))));
6731 Analyze_And_Resolve (N, Typ);
6735 -- Do required fixup of universal fixed operation
6737 if Typ = Universal_Fixed then
6738 Fixup_Universal_Fixed_Operation (N);
6742 -- Multiplications with fixed-point results
6744 if Is_Fixed_Point_Type (Typ) then
6746 -- No special processing if Treat_Fixed_As_Integer is set, since from
6747 -- a semantic point of view such operations are simply integer
6748 -- operations and will be treated that way.
6750 if not Treat_Fixed_As_Integer (N) then
6752 -- Case of fixed * integer => fixed
6754 if Is_Integer_Type (Rtyp) then
6755 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
6757 -- Case of integer * fixed => fixed
6759 elsif Is_Integer_Type (Ltyp) then
6760 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
6762 -- Case of fixed * fixed => fixed
6765 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
6769 -- Other cases of multiplication of fixed-point operands. Again we
6770 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
6772 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
6773 and then not Treat_Fixed_As_Integer (N)
6775 if Is_Integer_Type (Typ) then
6776 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
6778 pragma Assert (Is_Floating_Point_Type (Typ));
6779 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
6782 -- Mixed-mode operations can appear in a non-static universal context,
6783 -- in which case the integer argument must be converted explicitly.
6785 elsif Typ = Universal_Real
6786 and then Is_Integer_Type (Rtyp)
6788 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
6790 Analyze_And_Resolve (Rop, Universal_Real);
6792 elsif Typ = Universal_Real
6793 and then Is_Integer_Type (Ltyp)
6795 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
6797 Analyze_And_Resolve (Lop, Universal_Real);
6799 -- Non-fixed point cases, check software overflow checking required
6801 elsif Is_Signed_Integer_Type (Etype (N)) then
6802 Apply_Arithmetic_Overflow_Check (N);
6804 -- Deal with VAX float case
6806 elsif Vax_Float (Typ) then
6807 Expand_Vax_Arith (N);
6810 end Expand_N_Op_Multiply;
6812 --------------------
6813 -- Expand_N_Op_Ne --
6814 --------------------
6816 procedure Expand_N_Op_Ne (N : Node_Id) is
6817 Typ : constant Entity_Id := Etype (Left_Opnd (N));
6820 -- Case of elementary type with standard operator
6822 if Is_Elementary_Type (Typ)
6823 and then Sloc (Entity (N)) = Standard_Location
6825 Binary_Op_Validity_Checks (N);
6827 -- Boolean types (requiring handling of non-standard case)
6829 if Is_Boolean_Type (Typ) then
6830 Adjust_Condition (Left_Opnd (N));
6831 Adjust_Condition (Right_Opnd (N));
6832 Set_Etype (N, Standard_Boolean);
6833 Adjust_Result_Type (N, Typ);
6836 Rewrite_Comparison (N);
6838 -- If we still have comparison for Vax_Float, process it
6840 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
6841 Expand_Vax_Comparison (N);
6845 -- For all cases other than elementary types, we rewrite node as the
6846 -- negation of an equality operation, and reanalyze. The equality to be
6847 -- used is defined in the same scope and has the same signature. This
6848 -- signature must be set explicitly since in an instance it may not have
6849 -- the same visibility as in the generic unit. This avoids duplicating
6850 -- or factoring the complex code for record/array equality tests etc.
6854 Loc : constant Source_Ptr := Sloc (N);
6856 Ne : constant Entity_Id := Entity (N);
6859 Binary_Op_Validity_Checks (N);
6865 Left_Opnd => Left_Opnd (N),
6866 Right_Opnd => Right_Opnd (N)));
6867 Set_Paren_Count (Right_Opnd (Neg), 1);
6869 if Scope (Ne) /= Standard_Standard then
6870 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
6873 -- For navigation purposes, the inequality is treated as an
6874 -- implicit reference to the corresponding equality. Preserve the
6875 -- Comes_From_ source flag so that the proper Xref entry is
6878 Preserve_Comes_From_Source (Neg, N);
6879 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
6881 Analyze_And_Resolve (N, Standard_Boolean);
6886 ---------------------
6887 -- Expand_N_Op_Not --
6888 ---------------------
6890 -- If the argument is other than a Boolean array type, there is no special
6891 -- expansion required, except for VMS operations on signed integers.
6893 -- For the packed case, we call the special routine in Exp_Pakd, except
6894 -- that if the component size is greater than one, we use the standard
6895 -- routine generating a gruesome loop (it is so peculiar to have packed
6896 -- arrays with non-standard Boolean representations anyway, so it does not
6897 -- matter that we do not handle this case efficiently).
6899 -- For the unpacked case (and for the special packed case where we have non
6900 -- standard Booleans, as discussed above), we generate and insert into the
6901 -- tree the following function definition:
6903 -- function Nnnn (A : arr) is
6906 -- for J in a'range loop
6907 -- B (J) := not A (J);
6912 -- Here arr is the actual subtype of the parameter (and hence always
6913 -- constrained). Then we replace the not with a call to this function.
6915 procedure Expand_N_Op_Not (N : Node_Id) is
6916 Loc : constant Source_Ptr := Sloc (N);
6917 Typ : constant Entity_Id := Etype (N);
6926 Func_Name : Entity_Id;
6927 Loop_Statement : Node_Id;
6930 Unary_Op_Validity_Checks (N);
6932 -- For boolean operand, deal with non-standard booleans
6934 if Is_Boolean_Type (Typ) then
6935 Adjust_Condition (Right_Opnd (N));
6936 Set_Etype (N, Standard_Boolean);
6937 Adjust_Result_Type (N, Typ);
6941 -- For the VMS "not" on signed integer types, use conversion to and
6942 -- from a predefined modular type.
6944 if Is_VMS_Operator (Entity (N)) then
6950 -- If this is a derived type, retrieve original VMS type so that
6951 -- the proper sized type is used for intermediate values.
6953 if Is_Derived_Type (Typ) then
6954 Rtyp := First_Subtype (Etype (Typ));
6959 -- The proper unsigned type must have a size compatible with the
6960 -- operand, to prevent misalignment.
6962 if RM_Size (Rtyp) <= 8 then
6963 Utyp := RTE (RE_Unsigned_8);
6965 elsif RM_Size (Rtyp) <= 16 then
6966 Utyp := RTE (RE_Unsigned_16);
6968 elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
6969 Utyp := RTE (RE_Unsigned_32);
6972 Utyp := RTE (RE_Long_Long_Unsigned);
6976 Unchecked_Convert_To (Typ,
6978 Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
6979 Analyze_And_Resolve (N, Typ);
6984 -- Only array types need any other processing
6986 if not Is_Array_Type (Typ) then
6990 -- Case of array operand. If bit packed with a component size of 1,
6991 -- handle it in Exp_Pakd if the operand is known to be aligned.
6993 if Is_Bit_Packed_Array (Typ)
6994 and then Component_Size (Typ) = 1
6995 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
6997 Expand_Packed_Not (N);
7001 -- Case of array operand which is not bit-packed. If the context is
7002 -- a safe assignment, call in-place operation, If context is a larger
7003 -- boolean expression in the context of a safe assignment, expansion is
7004 -- done by enclosing operation.
7006 Opnd := Relocate_Node (Right_Opnd (N));
7007 Convert_To_Actual_Subtype (Opnd);
7008 Arr := Etype (Opnd);
7009 Ensure_Defined (Arr, N);
7010 Silly_Boolean_Array_Not_Test (N, Arr);
7012 if Nkind (Parent (N)) = N_Assignment_Statement then
7013 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
7014 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7017 -- Special case the negation of a binary operation
7019 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
7020 and then Safe_In_Place_Array_Op
7021 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
7023 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7027 elsif Nkind (Parent (N)) in N_Binary_Op
7028 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
7031 Op1 : constant Node_Id := Left_Opnd (Parent (N));
7032 Op2 : constant Node_Id := Right_Opnd (Parent (N));
7033 Lhs : constant Node_Id := Name (Parent (Parent (N)));
7036 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
7038 -- (not A) op (not B) can be reduced to a single call
7040 if N = Op1 and then Nkind (Op2) = N_Op_Not then
7043 elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
7046 -- A xor (not B) can also be special-cased
7048 elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
7055 A := Make_Defining_Identifier (Loc, Name_uA);
7056 B := Make_Defining_Identifier (Loc, Name_uB);
7057 J := Make_Defining_Identifier (Loc, Name_uJ);
7060 Make_Indexed_Component (Loc,
7061 Prefix => New_Reference_To (A, Loc),
7062 Expressions => New_List (New_Reference_To (J, Loc)));
7065 Make_Indexed_Component (Loc,
7066 Prefix => New_Reference_To (B, Loc),
7067 Expressions => New_List (New_Reference_To (J, Loc)));
7070 Make_Implicit_Loop_Statement (N,
7071 Identifier => Empty,
7074 Make_Iteration_Scheme (Loc,
7075 Loop_Parameter_Specification =>
7076 Make_Loop_Parameter_Specification (Loc,
7077 Defining_Identifier => J,
7078 Discrete_Subtype_Definition =>
7079 Make_Attribute_Reference (Loc,
7080 Prefix => Make_Identifier (Loc, Chars (A)),
7081 Attribute_Name => Name_Range))),
7083 Statements => New_List (
7084 Make_Assignment_Statement (Loc,
7086 Expression => Make_Op_Not (Loc, A_J))));
7088 Func_Name := Make_Temporary (Loc, 'N');
7089 Set_Is_Inlined (Func_Name);
7092 Make_Subprogram_Body (Loc,
7094 Make_Function_Specification (Loc,
7095 Defining_Unit_Name => Func_Name,
7096 Parameter_Specifications => New_List (
7097 Make_Parameter_Specification (Loc,
7098 Defining_Identifier => A,
7099 Parameter_Type => New_Reference_To (Typ, Loc))),
7100 Result_Definition => New_Reference_To (Typ, Loc)),
7102 Declarations => New_List (
7103 Make_Object_Declaration (Loc,
7104 Defining_Identifier => B,
7105 Object_Definition => New_Reference_To (Arr, Loc))),
7107 Handled_Statement_Sequence =>
7108 Make_Handled_Sequence_Of_Statements (Loc,
7109 Statements => New_List (
7111 Make_Simple_Return_Statement (Loc,
7112 Expression => Make_Identifier (Loc, Chars (B)))))));
7115 Make_Function_Call (Loc,
7116 Name => New_Reference_To (Func_Name, Loc),
7117 Parameter_Associations => New_List (Opnd)));
7119 Analyze_And_Resolve (N, Typ);
7120 end Expand_N_Op_Not;
7122 --------------------
7123 -- Expand_N_Op_Or --
7124 --------------------
7126 procedure Expand_N_Op_Or (N : Node_Id) is
7127 Typ : constant Entity_Id := Etype (N);
7130 Binary_Op_Validity_Checks (N);
7132 if Is_Array_Type (Etype (N)) then
7133 Expand_Boolean_Operator (N);
7135 elsif Is_Boolean_Type (Etype (N)) then
7137 -- Replace OR by OR ELSE if Short_Circuit_And_Or active and the type
7138 -- is standard Boolean (do not mess with AND that uses a non-standard
7139 -- Boolean type, because something strange is going on).
7141 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
7143 Make_Or_Else (Sloc (N),
7144 Left_Opnd => Relocate_Node (Left_Opnd (N)),
7145 Right_Opnd => Relocate_Node (Right_Opnd (N))));
7146 Analyze_And_Resolve (N, Typ);
7148 -- Otherwise, adjust conditions
7151 Adjust_Condition (Left_Opnd (N));
7152 Adjust_Condition (Right_Opnd (N));
7153 Set_Etype (N, Standard_Boolean);
7154 Adjust_Result_Type (N, Typ);
7157 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7158 Expand_Intrinsic_Call (N, Entity (N));
7163 ----------------------
7164 -- Expand_N_Op_Plus --
7165 ----------------------
7167 procedure Expand_N_Op_Plus (N : Node_Id) is
7169 Unary_Op_Validity_Checks (N);
7170 end Expand_N_Op_Plus;
7172 ---------------------
7173 -- Expand_N_Op_Rem --
7174 ---------------------
7176 procedure Expand_N_Op_Rem (N : Node_Id) is
7177 Loc : constant Source_Ptr := Sloc (N);
7178 Typ : constant Entity_Id := Etype (N);
7180 Left : constant Node_Id := Left_Opnd (N);
7181 Right : constant Node_Id := Right_Opnd (N);
7189 -- Set if corresponding operand can be negative
7191 pragma Unreferenced (Hi);
7194 Binary_Op_Validity_Checks (N);
7196 if Is_Integer_Type (Etype (N)) then
7197 Apply_Divide_Check (N);
7200 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
7201 -- but it is useful with other back ends (e.g. AAMP), and is certainly
7204 if Is_Integer_Type (Etype (N))
7205 and then Compile_Time_Known_Value (Right)
7206 and then Expr_Value (Right) = Uint_1
7208 -- Call Remove_Side_Effects to ensure that any side effects in the
7209 -- ignored left operand (in particular function calls to user defined
7210 -- functions) are properly executed.
7212 Remove_Side_Effects (Left);
7214 Rewrite (N, Make_Integer_Literal (Loc, 0));
7215 Analyze_And_Resolve (N, Typ);
7219 -- Deal with annoying case of largest negative number remainder minus
7220 -- one. Gigi does not handle this case correctly, because it generates
7221 -- a divide instruction which may trap in this case.
7223 -- In fact the check is quite easy, if the right operand is -1, then
7224 -- the remainder is always 0, and we can just ignore the left operand
7225 -- completely in this case.
7227 Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
7228 Lneg := (not OK) or else Lo < 0;
7230 Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
7231 Rneg := (not OK) or else Lo < 0;
7233 -- We won't mess with trying to find out if the left operand can really
7234 -- be the largest negative number (that's a pain in the case of private
7235 -- types and this is really marginal). We will just assume that we need
7236 -- the test if the left operand can be negative at all.
7238 if Lneg and Rneg then
7240 Make_Conditional_Expression (Loc,
7241 Expressions => New_List (
7243 Left_Opnd => Duplicate_Subexpr (Right),
7245 Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
7247 Unchecked_Convert_To (Typ,
7248 Make_Integer_Literal (Loc, Uint_0)),
7250 Relocate_Node (N))));
7252 Set_Analyzed (Next (Next (First (Expressions (N)))));
7253 Analyze_And_Resolve (N, Typ);
7255 end Expand_N_Op_Rem;
7257 -----------------------------
7258 -- Expand_N_Op_Rotate_Left --
7259 -----------------------------
7261 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
7263 Binary_Op_Validity_Checks (N);
7264 end Expand_N_Op_Rotate_Left;
7266 ------------------------------
7267 -- Expand_N_Op_Rotate_Right --
7268 ------------------------------
7270 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
7272 Binary_Op_Validity_Checks (N);
7273 end Expand_N_Op_Rotate_Right;
7275 ----------------------------
7276 -- Expand_N_Op_Shift_Left --
7277 ----------------------------
7279 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
7281 Binary_Op_Validity_Checks (N);
7282 end Expand_N_Op_Shift_Left;
7284 -----------------------------
7285 -- Expand_N_Op_Shift_Right --
7286 -----------------------------
7288 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
7290 Binary_Op_Validity_Checks (N);
7291 end Expand_N_Op_Shift_Right;
7293 ----------------------------------------
7294 -- Expand_N_Op_Shift_Right_Arithmetic --
7295 ----------------------------------------
7297 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
7299 Binary_Op_Validity_Checks (N);
7300 end Expand_N_Op_Shift_Right_Arithmetic;
7302 --------------------------
7303 -- Expand_N_Op_Subtract --
7304 --------------------------
7306 procedure Expand_N_Op_Subtract (N : Node_Id) is
7307 Typ : constant Entity_Id := Etype (N);
7310 Binary_Op_Validity_Checks (N);
7312 -- N - 0 = N for integer types
7314 if Is_Integer_Type (Typ)
7315 and then Compile_Time_Known_Value (Right_Opnd (N))
7316 and then Expr_Value (Right_Opnd (N)) = 0
7318 Rewrite (N, Left_Opnd (N));
7322 -- Arithmetic overflow checks for signed integer/fixed point types
7324 if Is_Signed_Integer_Type (Typ)
7326 Is_Fixed_Point_Type (Typ)
7328 Apply_Arithmetic_Overflow_Check (N);
7330 -- VAX floating-point types case
7332 elsif Vax_Float (Typ) then
7333 Expand_Vax_Arith (N);
7335 end Expand_N_Op_Subtract;
7337 ---------------------
7338 -- Expand_N_Op_Xor --
7339 ---------------------
7341 procedure Expand_N_Op_Xor (N : Node_Id) is
7342 Typ : constant Entity_Id := Etype (N);
7345 Binary_Op_Validity_Checks (N);
7347 if Is_Array_Type (Etype (N)) then
7348 Expand_Boolean_Operator (N);
7350 elsif Is_Boolean_Type (Etype (N)) then
7351 Adjust_Condition (Left_Opnd (N));
7352 Adjust_Condition (Right_Opnd (N));
7353 Set_Etype (N, Standard_Boolean);
7354 Adjust_Result_Type (N, Typ);
7356 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7357 Expand_Intrinsic_Call (N, Entity (N));
7360 end Expand_N_Op_Xor;
7362 ----------------------
7363 -- Expand_N_Or_Else --
7364 ----------------------
7366 procedure Expand_N_Or_Else (N : Node_Id)
7367 renames Expand_Short_Circuit_Operator;
7369 -----------------------------------
7370 -- Expand_N_Qualified_Expression --
7371 -----------------------------------
7373 procedure Expand_N_Qualified_Expression (N : Node_Id) is
7374 Operand : constant Node_Id := Expression (N);
7375 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
7378 -- Do validity check if validity checking operands
7380 if Validity_Checks_On
7381 and then Validity_Check_Operands
7383 Ensure_Valid (Operand);
7386 -- Apply possible constraint check
7388 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
7390 if Do_Range_Check (Operand) then
7391 Set_Do_Range_Check (Operand, False);
7392 Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
7394 end Expand_N_Qualified_Expression;
7396 ---------------------------------
7397 -- Expand_N_Selected_Component --
7398 ---------------------------------
7400 -- If the selector is a discriminant of a concurrent object, rewrite the
7401 -- prefix to denote the corresponding record type.
7403 procedure Expand_N_Selected_Component (N : Node_Id) is
7404 Loc : constant Source_Ptr := Sloc (N);
7405 Par : constant Node_Id := Parent (N);
7406 P : constant Node_Id := Prefix (N);
7407 Ptyp : Entity_Id := Underlying_Type (Etype (P));
7413 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
7414 -- Gigi needs a temporary for prefixes that depend on a discriminant,
7415 -- unless the context of an assignment can provide size information.
7416 -- Don't we have a general routine that does this???
7418 -----------------------
7419 -- In_Left_Hand_Side --
7420 -----------------------
7422 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
7424 return (Nkind (Parent (Comp)) = N_Assignment_Statement
7425 and then Comp = Name (Parent (Comp)))
7426 or else (Present (Parent (Comp))
7427 and then Nkind (Parent (Comp)) in N_Subexpr
7428 and then In_Left_Hand_Side (Parent (Comp)));
7429 end In_Left_Hand_Side;
7431 -- Start of processing for Expand_N_Selected_Component
7434 -- Insert explicit dereference if required
7436 if Is_Access_Type (Ptyp) then
7437 Insert_Explicit_Dereference (P);
7438 Analyze_And_Resolve (P, Designated_Type (Ptyp));
7440 if Ekind (Etype (P)) = E_Private_Subtype
7441 and then Is_For_Access_Subtype (Etype (P))
7443 Set_Etype (P, Base_Type (Etype (P)));
7449 -- Deal with discriminant check required
7451 if Do_Discriminant_Check (N) then
7453 -- Present the discriminant checking function to the backend, so that
7454 -- it can inline the call to the function.
7457 (Discriminant_Checking_Func
7458 (Original_Record_Component (Entity (Selector_Name (N)))));
7460 -- Now reset the flag and generate the call
7462 Set_Do_Discriminant_Check (N, False);
7463 Generate_Discriminant_Check (N);
7466 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7467 -- function, then additional actuals must be passed.
7469 if Ada_Version >= Ada_2005
7470 and then Is_Build_In_Place_Function_Call (P)
7472 Make_Build_In_Place_Call_In_Anonymous_Context (P);
7475 -- Gigi cannot handle unchecked conversions that are the prefix of a
7476 -- selected component with discriminants. This must be checked during
7477 -- expansion, because during analysis the type of the selector is not
7478 -- known at the point the prefix is analyzed. If the conversion is the
7479 -- target of an assignment, then we cannot force the evaluation.
7481 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
7482 and then Has_Discriminants (Etype (N))
7483 and then not In_Left_Hand_Side (N)
7485 Force_Evaluation (Prefix (N));
7488 -- Remaining processing applies only if selector is a discriminant
7490 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
7492 -- If the selector is a discriminant of a constrained record type,
7493 -- we may be able to rewrite the expression with the actual value
7494 -- of the discriminant, a useful optimization in some cases.
7496 if Is_Record_Type (Ptyp)
7497 and then Has_Discriminants (Ptyp)
7498 and then Is_Constrained (Ptyp)
7500 -- Do this optimization for discrete types only, and not for
7501 -- access types (access discriminants get us into trouble!)
7503 if not Is_Discrete_Type (Etype (N)) then
7506 -- Don't do this on the left hand of an assignment statement.
7507 -- Normally one would think that references like this would not
7508 -- occur, but they do in generated code, and mean that we really
7509 -- do want to assign the discriminant!
7511 elsif Nkind (Par) = N_Assignment_Statement
7512 and then Name (Par) = N
7516 -- Don't do this optimization for the prefix of an attribute or
7517 -- the name of an object renaming declaration since these are
7518 -- contexts where we do not want the value anyway.
7520 elsif (Nkind (Par) = N_Attribute_Reference
7521 and then Prefix (Par) = N)
7522 or else Is_Renamed_Object (N)
7526 -- Don't do this optimization if we are within the code for a
7527 -- discriminant check, since the whole point of such a check may
7528 -- be to verify the condition on which the code below depends!
7530 elsif Is_In_Discriminant_Check (N) then
7533 -- Green light to see if we can do the optimization. There is
7534 -- still one condition that inhibits the optimization below but
7535 -- now is the time to check the particular discriminant.
7538 -- Loop through discriminants to find the matching discriminant
7539 -- constraint to see if we can copy it.
7541 Disc := First_Discriminant (Ptyp);
7542 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
7544 Discr_Loop : while Present (Dcon) loop
7545 Dval := Node (Dcon);
7547 -- Check if this is the matching discriminant
7549 if Disc = Entity (Selector_Name (N)) then
7551 -- Here we have the matching discriminant. Check for
7552 -- the case of a discriminant of a component that is
7553 -- constrained by an outer discriminant, which cannot
7554 -- be optimized away.
7556 if Denotes_Discriminant
7557 (Dval, Check_Concurrent => True)
7561 elsif Nkind (Original_Node (Dval)) = N_Selected_Component
7563 Denotes_Discriminant
7564 (Selector_Name (Original_Node (Dval)), True)
7568 -- Do not retrieve value if constraint is not static. It
7569 -- is generally not useful, and the constraint may be a
7570 -- rewritten outer discriminant in which case it is in
7573 elsif Is_Entity_Name (Dval)
7574 and then Nkind (Parent (Entity (Dval)))
7575 = N_Object_Declaration
7576 and then Present (Expression (Parent (Entity (Dval))))
7578 not Is_Static_Expression
7579 (Expression (Parent (Entity (Dval))))
7583 -- In the context of a case statement, the expression may
7584 -- have the base type of the discriminant, and we need to
7585 -- preserve the constraint to avoid spurious errors on
7588 elsif Nkind (Parent (N)) = N_Case_Statement
7589 and then Etype (Dval) /= Etype (Disc)
7592 Make_Qualified_Expression (Loc,
7594 New_Occurrence_Of (Etype (Disc), Loc),
7596 New_Copy_Tree (Dval)));
7597 Analyze_And_Resolve (N, Etype (Disc));
7599 -- In case that comes out as a static expression,
7600 -- reset it (a selected component is never static).
7602 Set_Is_Static_Expression (N, False);
7605 -- Otherwise we can just copy the constraint, but the
7606 -- result is certainly not static! In some cases the
7607 -- discriminant constraint has been analyzed in the
7608 -- context of the original subtype indication, but for
7609 -- itypes the constraint might not have been analyzed
7610 -- yet, and this must be done now.
7613 Rewrite (N, New_Copy_Tree (Dval));
7614 Analyze_And_Resolve (N);
7615 Set_Is_Static_Expression (N, False);
7621 Next_Discriminant (Disc);
7622 end loop Discr_Loop;
7624 -- Note: the above loop should always find a matching
7625 -- discriminant, but if it does not, we just missed an
7626 -- optimization due to some glitch (perhaps a previous error),
7632 -- The only remaining processing is in the case of a discriminant of
7633 -- a concurrent object, where we rewrite the prefix to denote the
7634 -- corresponding record type. If the type is derived and has renamed
7635 -- discriminants, use corresponding discriminant, which is the one
7636 -- that appears in the corresponding record.
7638 if not Is_Concurrent_Type (Ptyp) then
7642 Disc := Entity (Selector_Name (N));
7644 if Is_Derived_Type (Ptyp)
7645 and then Present (Corresponding_Discriminant (Disc))
7647 Disc := Corresponding_Discriminant (Disc);
7651 Make_Selected_Component (Loc,
7653 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
7655 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
7660 end Expand_N_Selected_Component;
7662 --------------------
7663 -- Expand_N_Slice --
7664 --------------------
7666 procedure Expand_N_Slice (N : Node_Id) is
7667 Loc : constant Source_Ptr := Sloc (N);
7668 Typ : constant Entity_Id := Etype (N);
7669 Pfx : constant Node_Id := Prefix (N);
7670 Ptp : Entity_Id := Etype (Pfx);
7672 function Is_Procedure_Actual (N : Node_Id) return Boolean;
7673 -- Check whether the argument is an actual for a procedure call, in
7674 -- which case the expansion of a bit-packed slice is deferred until the
7675 -- call itself is expanded. The reason this is required is that we might
7676 -- have an IN OUT or OUT parameter, and the copy out is essential, and
7677 -- that copy out would be missed if we created a temporary here in
7678 -- Expand_N_Slice. Note that we don't bother to test specifically for an
7679 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
7680 -- is harmless to defer expansion in the IN case, since the call
7681 -- processing will still generate the appropriate copy in operation,
7682 -- which will take care of the slice.
7684 procedure Make_Temporary_For_Slice;
7685 -- Create a named variable for the value of the slice, in cases where
7686 -- the back-end cannot handle it properly, e.g. when packed types or
7687 -- unaligned slices are involved.
7689 -------------------------
7690 -- Is_Procedure_Actual --
7691 -------------------------
7693 function Is_Procedure_Actual (N : Node_Id) return Boolean is
7694 Par : Node_Id := Parent (N);
7698 -- If our parent is a procedure call we can return
7700 if Nkind (Par) = N_Procedure_Call_Statement then
7703 -- If our parent is a type conversion, keep climbing the tree,
7704 -- since a type conversion can be a procedure actual. Also keep
7705 -- climbing if parameter association or a qualified expression,
7706 -- since these are additional cases that do can appear on
7707 -- procedure actuals.
7709 elsif Nkind_In (Par, N_Type_Conversion,
7710 N_Parameter_Association,
7711 N_Qualified_Expression)
7713 Par := Parent (Par);
7715 -- Any other case is not what we are looking for
7721 end Is_Procedure_Actual;
7723 ------------------------------
7724 -- Make_Temporary_For_Slice --
7725 ------------------------------
7727 procedure Make_Temporary_For_Slice is
7729 Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
7733 Make_Object_Declaration (Loc,
7734 Defining_Identifier => Ent,
7735 Object_Definition => New_Occurrence_Of (Typ, Loc));
7737 Set_No_Initialization (Decl);
7739 Insert_Actions (N, New_List (
7741 Make_Assignment_Statement (Loc,
7742 Name => New_Occurrence_Of (Ent, Loc),
7743 Expression => Relocate_Node (N))));
7745 Rewrite (N, New_Occurrence_Of (Ent, Loc));
7746 Analyze_And_Resolve (N, Typ);
7747 end Make_Temporary_For_Slice;
7749 -- Start of processing for Expand_N_Slice
7752 -- Special handling for access types
7754 if Is_Access_Type (Ptp) then
7756 Ptp := Designated_Type (Ptp);
7759 Make_Explicit_Dereference (Sloc (N),
7760 Prefix => Relocate_Node (Pfx)));
7762 Analyze_And_Resolve (Pfx, Ptp);
7765 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7766 -- function, then additional actuals must be passed.
7768 if Ada_Version >= Ada_2005
7769 and then Is_Build_In_Place_Function_Call (Pfx)
7771 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
7774 -- The remaining case to be handled is packed slices. We can leave
7775 -- packed slices as they are in the following situations:
7777 -- 1. Right or left side of an assignment (we can handle this
7778 -- situation correctly in the assignment statement expansion).
7780 -- 2. Prefix of indexed component (the slide is optimized away in this
7781 -- case, see the start of Expand_N_Slice.)
7783 -- 3. Object renaming declaration, since we want the name of the
7784 -- slice, not the value.
7786 -- 4. Argument to procedure call, since copy-in/copy-out handling may
7787 -- be required, and this is handled in the expansion of call
7790 -- 5. Prefix of an address attribute (this is an error which is caught
7791 -- elsewhere, and the expansion would interfere with generating the
7794 if not Is_Packed (Typ) then
7796 -- Apply transformation for actuals of a function call, where
7797 -- Expand_Actuals is not used.
7799 if Nkind (Parent (N)) = N_Function_Call
7800 and then Is_Possibly_Unaligned_Slice (N)
7802 Make_Temporary_For_Slice;
7805 elsif Nkind (Parent (N)) = N_Assignment_Statement
7806 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
7807 and then Parent (N) = Name (Parent (Parent (N))))
7811 elsif Nkind (Parent (N)) = N_Indexed_Component
7812 or else Is_Renamed_Object (N)
7813 or else Is_Procedure_Actual (N)
7817 elsif Nkind (Parent (N)) = N_Attribute_Reference
7818 and then Attribute_Name (Parent (N)) = Name_Address
7823 Make_Temporary_For_Slice;
7827 ------------------------------
7828 -- Expand_N_Type_Conversion --
7829 ------------------------------
7831 procedure Expand_N_Type_Conversion (N : Node_Id) is
7832 Loc : constant Source_Ptr := Sloc (N);
7833 Operand : constant Node_Id := Expression (N);
7834 Target_Type : constant Entity_Id := Etype (N);
7835 Operand_Type : Entity_Id := Etype (Operand);
7837 procedure Handle_Changed_Representation;
7838 -- This is called in the case of record and array type conversions to
7839 -- see if there is a change of representation to be handled. Change of
7840 -- representation is actually handled at the assignment statement level,
7841 -- and what this procedure does is rewrite node N conversion as an
7842 -- assignment to temporary. If there is no change of representation,
7843 -- then the conversion node is unchanged.
7845 procedure Raise_Accessibility_Error;
7846 -- Called when we know that an accessibility check will fail. Rewrites
7847 -- node N to an appropriate raise statement and outputs warning msgs.
7848 -- The Etype of the raise node is set to Target_Type.
7850 procedure Real_Range_Check;
7851 -- Handles generation of range check for real target value
7853 -----------------------------------
7854 -- Handle_Changed_Representation --
7855 -----------------------------------
7857 procedure Handle_Changed_Representation is
7866 -- Nothing else to do if no change of representation
7868 if Same_Representation (Operand_Type, Target_Type) then
7871 -- The real change of representation work is done by the assignment
7872 -- statement processing. So if this type conversion is appearing as
7873 -- the expression of an assignment statement, nothing needs to be
7874 -- done to the conversion.
7876 elsif Nkind (Parent (N)) = N_Assignment_Statement then
7879 -- Otherwise we need to generate a temporary variable, and do the
7880 -- change of representation assignment into that temporary variable.
7881 -- The conversion is then replaced by a reference to this variable.
7886 -- If type is unconstrained we have to add a constraint, copied
7887 -- from the actual value of the left hand side.
7889 if not Is_Constrained (Target_Type) then
7890 if Has_Discriminants (Operand_Type) then
7891 Disc := First_Discriminant (Operand_Type);
7893 if Disc /= First_Stored_Discriminant (Operand_Type) then
7894 Disc := First_Stored_Discriminant (Operand_Type);
7898 while Present (Disc) loop
7900 Make_Selected_Component (Loc,
7901 Prefix => Duplicate_Subexpr_Move_Checks (Operand),
7903 Make_Identifier (Loc, Chars (Disc))));
7904 Next_Discriminant (Disc);
7907 elsif Is_Array_Type (Operand_Type) then
7908 N_Ix := First_Index (Target_Type);
7911 for J in 1 .. Number_Dimensions (Operand_Type) loop
7913 -- We convert the bounds explicitly. We use an unchecked
7914 -- conversion because bounds checks are done elsewhere.
7919 Unchecked_Convert_To (Etype (N_Ix),
7920 Make_Attribute_Reference (Loc,
7922 Duplicate_Subexpr_No_Checks
7923 (Operand, Name_Req => True),
7924 Attribute_Name => Name_First,
7925 Expressions => New_List (
7926 Make_Integer_Literal (Loc, J)))),
7929 Unchecked_Convert_To (Etype (N_Ix),
7930 Make_Attribute_Reference (Loc,
7932 Duplicate_Subexpr_No_Checks
7933 (Operand, Name_Req => True),
7934 Attribute_Name => Name_Last,
7935 Expressions => New_List (
7936 Make_Integer_Literal (Loc, J))))));
7943 Odef := New_Occurrence_Of (Target_Type, Loc);
7945 if Present (Cons) then
7947 Make_Subtype_Indication (Loc,
7948 Subtype_Mark => Odef,
7950 Make_Index_Or_Discriminant_Constraint (Loc,
7951 Constraints => Cons));
7954 Temp := Make_Temporary (Loc, 'C');
7956 Make_Object_Declaration (Loc,
7957 Defining_Identifier => Temp,
7958 Object_Definition => Odef);
7960 Set_No_Initialization (Decl, True);
7962 -- Insert required actions. It is essential to suppress checks
7963 -- since we have suppressed default initialization, which means
7964 -- that the variable we create may have no discriminants.
7969 Make_Assignment_Statement (Loc,
7970 Name => New_Occurrence_Of (Temp, Loc),
7971 Expression => Relocate_Node (N))),
7972 Suppress => All_Checks);
7974 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7977 end Handle_Changed_Representation;
7979 -------------------------------
7980 -- Raise_Accessibility_Error --
7981 -------------------------------
7983 procedure Raise_Accessibility_Error is
7986 Make_Raise_Program_Error (Sloc (N),
7987 Reason => PE_Accessibility_Check_Failed));
7988 Set_Etype (N, Target_Type);
7990 Error_Msg_N ("?accessibility check failure", N);
7992 ("\?& will be raised at run time", N, Standard_Program_Error);
7993 end Raise_Accessibility_Error;
7995 ----------------------
7996 -- Real_Range_Check --
7997 ----------------------
7999 -- Case of conversions to floating-point or fixed-point. If range checks
8000 -- are enabled and the target type has a range constraint, we convert:
8006 -- Tnn : typ'Base := typ'Base (x);
8007 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
8010 -- This is necessary when there is a conversion of integer to float or
8011 -- to fixed-point to ensure that the correct checks are made. It is not
8012 -- necessary for float to float where it is enough to simply set the
8013 -- Do_Range_Check flag.
8015 procedure Real_Range_Check is
8016 Btyp : constant Entity_Id := Base_Type (Target_Type);
8017 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
8018 Hi : constant Node_Id := Type_High_Bound (Target_Type);
8019 Xtyp : constant Entity_Id := Etype (Operand);
8024 -- Nothing to do if conversion was rewritten
8026 if Nkind (N) /= N_Type_Conversion then
8030 -- Nothing to do if range checks suppressed, or target has the same
8031 -- range as the base type (or is the base type).
8033 if Range_Checks_Suppressed (Target_Type)
8034 or else (Lo = Type_Low_Bound (Btyp)
8036 Hi = Type_High_Bound (Btyp))
8041 -- Nothing to do if expression is an entity on which checks have been
8044 if Is_Entity_Name (Operand)
8045 and then Range_Checks_Suppressed (Entity (Operand))
8050 -- Nothing to do if bounds are all static and we can tell that the
8051 -- expression is within the bounds of the target. Note that if the
8052 -- operand is of an unconstrained floating-point type, then we do
8053 -- not trust it to be in range (might be infinite)
8056 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
8057 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
8060 if (not Is_Floating_Point_Type (Xtyp)
8061 or else Is_Constrained (Xtyp))
8062 and then Compile_Time_Known_Value (S_Lo)
8063 and then Compile_Time_Known_Value (S_Hi)
8064 and then Compile_Time_Known_Value (Hi)
8065 and then Compile_Time_Known_Value (Lo)
8068 D_Lov : constant Ureal := Expr_Value_R (Lo);
8069 D_Hiv : constant Ureal := Expr_Value_R (Hi);
8074 if Is_Real_Type (Xtyp) then
8075 S_Lov := Expr_Value_R (S_Lo);
8076 S_Hiv := Expr_Value_R (S_Hi);
8078 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
8079 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
8083 and then S_Lov >= D_Lov
8084 and then S_Hiv <= D_Hiv
8086 Set_Do_Range_Check (Operand, False);
8093 -- For float to float conversions, we are done
8095 if Is_Floating_Point_Type (Xtyp)
8097 Is_Floating_Point_Type (Btyp)
8102 -- Otherwise rewrite the conversion as described above
8104 Conv := Relocate_Node (N);
8105 Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
8106 Set_Etype (Conv, Btyp);
8108 -- Enable overflow except for case of integer to float conversions,
8109 -- where it is never required, since we can never have overflow in
8112 if not Is_Integer_Type (Etype (Operand)) then
8113 Enable_Overflow_Check (Conv);
8116 Tnn := Make_Temporary (Loc, 'T', Conv);
8118 Insert_Actions (N, New_List (
8119 Make_Object_Declaration (Loc,
8120 Defining_Identifier => Tnn,
8121 Object_Definition => New_Occurrence_Of (Btyp, Loc),
8122 Constant_Present => True,
8123 Expression => Conv),
8125 Make_Raise_Constraint_Error (Loc,
8130 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8132 Make_Attribute_Reference (Loc,
8133 Attribute_Name => Name_First,
8135 New_Occurrence_Of (Target_Type, Loc))),
8139 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8141 Make_Attribute_Reference (Loc,
8142 Attribute_Name => Name_Last,
8144 New_Occurrence_Of (Target_Type, Loc)))),
8145 Reason => CE_Range_Check_Failed)));
8147 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
8148 Analyze_And_Resolve (N, Btyp);
8149 end Real_Range_Check;
8151 -- Start of processing for Expand_N_Type_Conversion
8154 -- Nothing at all to do if conversion is to the identical type so remove
8155 -- the conversion completely, it is useless, except that it may carry
8156 -- an Assignment_OK attribute, which must be propagated to the operand.
8158 if Operand_Type = Target_Type then
8159 if Assignment_OK (N) then
8160 Set_Assignment_OK (Operand);
8163 Rewrite (N, Relocate_Node (Operand));
8167 -- Nothing to do if this is the second argument of read. This is a
8168 -- "backwards" conversion that will be handled by the specialized code
8169 -- in attribute processing.
8171 if Nkind (Parent (N)) = N_Attribute_Reference
8172 and then Attribute_Name (Parent (N)) = Name_Read
8173 and then Next (First (Expressions (Parent (N)))) = N
8178 -- Check for case of converting to a type that has an invariant
8179 -- associated with it. This required an invariant check. We convert
8185 -- do invariant_check (typ (expr)) in typ (expr);
8187 -- using Duplicate_Subexpr to avoid multiple side effects
8189 -- Note: the Comes_From_Source check, and then the resetting of this
8190 -- flag prevents what would otherwise be an infinite recursion.
8192 if Present (Invariant_Procedure (Target_Type))
8193 and then Comes_From_Source (N)
8195 Set_Comes_From_Source (N, False);
8197 Make_Expression_With_Actions (Loc,
8198 Actions => New_List (
8199 Make_Invariant_Call (Duplicate_Subexpr (N))),
8200 Expression => Duplicate_Subexpr_No_Checks (N)));
8201 Analyze_And_Resolve (N, Target_Type);
8205 -- Here if we may need to expand conversion
8207 -- If the operand of the type conversion is an arithmetic operation on
8208 -- signed integers, and the based type of the signed integer type in
8209 -- question is smaller than Standard.Integer, we promote both of the
8210 -- operands to type Integer.
8212 -- For example, if we have
8214 -- target-type (opnd1 + opnd2)
8216 -- and opnd1 and opnd2 are of type short integer, then we rewrite
8219 -- target-type (integer(opnd1) + integer(opnd2))
8221 -- We do this because we are always allowed to compute in a larger type
8222 -- if we do the right thing with the result, and in this case we are
8223 -- going to do a conversion which will do an appropriate check to make
8224 -- sure that things are in range of the target type in any case. This
8225 -- avoids some unnecessary intermediate overflows.
8227 -- We might consider a similar transformation in the case where the
8228 -- target is a real type or a 64-bit integer type, and the operand
8229 -- is an arithmetic operation using a 32-bit integer type. However,
8230 -- we do not bother with this case, because it could cause significant
8231 -- ineffiencies on 32-bit machines. On a 64-bit machine it would be
8232 -- much cheaper, but we don't want different behavior on 32-bit and
8233 -- 64-bit machines. Note that the exclusion of the 64-bit case also
8234 -- handles the configurable run-time cases where 64-bit arithmetic
8235 -- may simply be unavailable.
8237 -- Note: this circuit is partially redundant with respect to the circuit
8238 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
8239 -- the processing here. Also we still need the Checks circuit, since we
8240 -- have to be sure not to generate junk overflow checks in the first
8241 -- place, since it would be trick to remove them here!
8243 if Integer_Promotion_Possible (N) then
8245 -- All conditions met, go ahead with transformation
8253 Make_Type_Conversion (Loc,
8254 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8255 Expression => Relocate_Node (Right_Opnd (Operand)));
8257 Opnd := New_Op_Node (Nkind (Operand), Loc);
8258 Set_Right_Opnd (Opnd, R);
8260 if Nkind (Operand) in N_Binary_Op then
8262 Make_Type_Conversion (Loc,
8263 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8264 Expression => Relocate_Node (Left_Opnd (Operand)));
8266 Set_Left_Opnd (Opnd, L);
8270 Make_Type_Conversion (Loc,
8271 Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
8272 Expression => Opnd));
8274 Analyze_And_Resolve (N, Target_Type);
8279 -- Do validity check if validity checking operands
8281 if Validity_Checks_On
8282 and then Validity_Check_Operands
8284 Ensure_Valid (Operand);
8287 -- Special case of converting from non-standard boolean type
8289 if Is_Boolean_Type (Operand_Type)
8290 and then (Nonzero_Is_True (Operand_Type))
8292 Adjust_Condition (Operand);
8293 Set_Etype (Operand, Standard_Boolean);
8294 Operand_Type := Standard_Boolean;
8297 -- Case of converting to an access type
8299 if Is_Access_Type (Target_Type) then
8301 -- Apply an accessibility check when the conversion operand is an
8302 -- access parameter (or a renaming thereof), unless conversion was
8303 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
8304 -- Note that other checks may still need to be applied below (such
8305 -- as tagged type checks).
8307 if Is_Entity_Name (Operand)
8309 (Is_Formal (Entity (Operand))
8311 (Present (Renamed_Object (Entity (Operand)))
8312 and then Is_Entity_Name (Renamed_Object (Entity (Operand)))
8314 (Entity (Renamed_Object (Entity (Operand))))))
8315 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
8316 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
8317 or else Attribute_Name (Original_Node (N)) = Name_Access)
8319 Apply_Accessibility_Check
8320 (Operand, Target_Type, Insert_Node => Operand);
8322 -- If the level of the operand type is statically deeper than the
8323 -- level of the target type, then force Program_Error. Note that this
8324 -- can only occur for cases where the attribute is within the body of
8325 -- an instantiation (otherwise the conversion will already have been
8326 -- rejected as illegal). Note: warnings are issued by the analyzer
8327 -- for the instance cases.
8329 elsif In_Instance_Body
8330 and then Type_Access_Level (Operand_Type) >
8331 Type_Access_Level (Target_Type)
8333 Raise_Accessibility_Error;
8335 -- When the operand is a selected access discriminant the check needs
8336 -- to be made against the level of the object denoted by the prefix
8337 -- of the selected name. Force Program_Error for this case as well
8338 -- (this accessibility violation can only happen if within the body
8339 -- of an instantiation).
8341 elsif In_Instance_Body
8342 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
8343 and then Nkind (Operand) = N_Selected_Component
8344 and then Object_Access_Level (Operand) >
8345 Type_Access_Level (Target_Type)
8347 Raise_Accessibility_Error;
8352 -- Case of conversions of tagged types and access to tagged types
8354 -- When needed, that is to say when the expression is class-wide, Add
8355 -- runtime a tag check for (strict) downward conversion by using the
8356 -- membership test, generating:
8358 -- [constraint_error when Operand not in Target_Type'Class]
8360 -- or in the access type case
8362 -- [constraint_error
8363 -- when Operand /= null
8364 -- and then Operand.all not in
8365 -- Designated_Type (Target_Type)'Class]
8367 if (Is_Access_Type (Target_Type)
8368 and then Is_Tagged_Type (Designated_Type (Target_Type)))
8369 or else Is_Tagged_Type (Target_Type)
8371 -- Do not do any expansion in the access type case if the parent is a
8372 -- renaming, since this is an error situation which will be caught by
8373 -- Sem_Ch8, and the expansion can interfere with this error check.
8375 if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
8379 -- Otherwise, proceed with processing tagged conversion
8381 Tagged_Conversion : declare
8382 Actual_Op_Typ : Entity_Id;
8383 Actual_Targ_Typ : Entity_Id;
8384 Make_Conversion : Boolean := False;
8385 Root_Op_Typ : Entity_Id;
8387 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
8388 -- Create a membership check to test whether Operand is a member
8389 -- of Targ_Typ. If the original Target_Type is an access, include
8390 -- a test for null value. The check is inserted at N.
8392 --------------------
8393 -- Make_Tag_Check --
8394 --------------------
8396 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
8401 -- [Constraint_Error
8402 -- when Operand /= null
8403 -- and then Operand.all not in Targ_Typ]
8405 if Is_Access_Type (Target_Type) then
8410 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8411 Right_Opnd => Make_Null (Loc)),
8416 Make_Explicit_Dereference (Loc,
8417 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
8418 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
8421 -- [Constraint_Error when Operand not in Targ_Typ]
8426 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8427 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
8431 Make_Raise_Constraint_Error (Loc,
8433 Reason => CE_Tag_Check_Failed));
8436 -- Start of processing for Tagged_Conversion
8439 if Is_Access_Type (Target_Type) then
8441 -- Handle entities from the limited view
8444 Available_View (Designated_Type (Operand_Type));
8446 Available_View (Designated_Type (Target_Type));
8448 Actual_Op_Typ := Operand_Type;
8449 Actual_Targ_Typ := Target_Type;
8452 Root_Op_Typ := Root_Type (Actual_Op_Typ);
8454 -- Ada 2005 (AI-251): Handle interface type conversion
8456 if Is_Interface (Actual_Op_Typ) then
8457 Expand_Interface_Conversion (N, Is_Static => False);
8461 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
8463 -- Create a runtime tag check for a downward class-wide type
8466 if Is_Class_Wide_Type (Actual_Op_Typ)
8467 and then Actual_Op_Typ /= Actual_Targ_Typ
8468 and then Root_Op_Typ /= Actual_Targ_Typ
8469 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ)
8471 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
8472 Make_Conversion := True;
8475 -- AI05-0073: If the result subtype of the function is defined
8476 -- by an access_definition designating a specific tagged type
8477 -- T, a check is made that the result value is null or the tag
8478 -- of the object designated by the result value identifies T.
8479 -- Constraint_Error is raised if this check fails.
8481 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
8484 Func_Typ : Entity_Id;
8487 -- Climb scope stack looking for the enclosing function
8489 Func := Current_Scope;
8490 while Present (Func)
8491 and then Ekind (Func) /= E_Function
8493 Func := Scope (Func);
8496 -- The function's return subtype must be defined using
8497 -- an access definition.
8499 if Nkind (Result_Definition (Parent (Func))) =
8502 Func_Typ := Directly_Designated_Type (Etype (Func));
8504 -- The return subtype denotes a specific tagged type,
8505 -- in other words, a non class-wide type.
8507 if Is_Tagged_Type (Func_Typ)
8508 and then not Is_Class_Wide_Type (Func_Typ)
8510 Make_Tag_Check (Actual_Targ_Typ);
8511 Make_Conversion := True;
8517 -- We have generated a tag check for either a class-wide type
8518 -- conversion or for AI05-0073.
8520 if Make_Conversion then
8525 Make_Unchecked_Type_Conversion (Loc,
8526 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
8527 Expression => Relocate_Node (Expression (N)));
8529 Analyze_And_Resolve (N, Target_Type);
8533 end Tagged_Conversion;
8535 -- Case of other access type conversions
8537 elsif Is_Access_Type (Target_Type) then
8538 Apply_Constraint_Check (Operand, Target_Type);
8540 -- Case of conversions from a fixed-point type
8542 -- These conversions require special expansion and processing, found in
8543 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
8544 -- since from a semantic point of view, these are simple integer
8545 -- conversions, which do not need further processing.
8547 elsif Is_Fixed_Point_Type (Operand_Type)
8548 and then not Conversion_OK (N)
8550 -- We should never see universal fixed at this case, since the
8551 -- expansion of the constituent divide or multiply should have
8552 -- eliminated the explicit mention of universal fixed.
8554 pragma Assert (Operand_Type /= Universal_Fixed);
8556 -- Check for special case of the conversion to universal real that
8557 -- occurs as a result of the use of a round attribute. In this case,
8558 -- the real type for the conversion is taken from the target type of
8559 -- the Round attribute and the result must be marked as rounded.
8561 if Target_Type = Universal_Real
8562 and then Nkind (Parent (N)) = N_Attribute_Reference
8563 and then Attribute_Name (Parent (N)) = Name_Round
8565 Set_Rounded_Result (N);
8566 Set_Etype (N, Etype (Parent (N)));
8569 -- Otherwise do correct fixed-conversion, but skip these if the
8570 -- Conversion_OK flag is set, because from a semantic point of view
8571 -- these are simple integer conversions needing no further processing
8572 -- (the backend will simply treat them as integers).
8574 if not Conversion_OK (N) then
8575 if Is_Fixed_Point_Type (Etype (N)) then
8576 Expand_Convert_Fixed_To_Fixed (N);
8579 elsif Is_Integer_Type (Etype (N)) then
8580 Expand_Convert_Fixed_To_Integer (N);
8583 pragma Assert (Is_Floating_Point_Type (Etype (N)));
8584 Expand_Convert_Fixed_To_Float (N);
8589 -- Case of conversions to a fixed-point type
8591 -- These conversions require special expansion and processing, found in
8592 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
8593 -- since from a semantic point of view, these are simple integer
8594 -- conversions, which do not need further processing.
8596 elsif Is_Fixed_Point_Type (Target_Type)
8597 and then not Conversion_OK (N)
8599 if Is_Integer_Type (Operand_Type) then
8600 Expand_Convert_Integer_To_Fixed (N);
8603 pragma Assert (Is_Floating_Point_Type (Operand_Type));
8604 Expand_Convert_Float_To_Fixed (N);
8608 -- Case of float-to-integer conversions
8610 -- We also handle float-to-fixed conversions with Conversion_OK set
8611 -- since semantically the fixed-point target is treated as though it
8612 -- were an integer in such cases.
8614 elsif Is_Floating_Point_Type (Operand_Type)
8616 (Is_Integer_Type (Target_Type)
8618 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
8620 -- One more check here, gcc is still not able to do conversions of
8621 -- this type with proper overflow checking, and so gigi is doing an
8622 -- approximation of what is required by doing floating-point compares
8623 -- with the end-point. But that can lose precision in some cases, and
8624 -- give a wrong result. Converting the operand to Universal_Real is
8625 -- helpful, but still does not catch all cases with 64-bit integers
8626 -- on targets with only 64-bit floats.
8628 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
8629 -- Can this code be removed ???
8631 if Do_Range_Check (Operand) then
8633 Make_Type_Conversion (Loc,
8635 New_Occurrence_Of (Universal_Real, Loc),
8637 Relocate_Node (Operand)));
8639 Set_Etype (Operand, Universal_Real);
8640 Enable_Range_Check (Operand);
8641 Set_Do_Range_Check (Expression (Operand), False);
8644 -- Case of array conversions
8646 -- Expansion of array conversions, add required length/range checks but
8647 -- only do this if there is no change of representation. For handling of
8648 -- this case, see Handle_Changed_Representation.
8650 elsif Is_Array_Type (Target_Type) then
8652 if Is_Constrained (Target_Type) then
8653 Apply_Length_Check (Operand, Target_Type);
8655 Apply_Range_Check (Operand, Target_Type);
8658 Handle_Changed_Representation;
8660 -- Case of conversions of discriminated types
8662 -- Add required discriminant checks if target is constrained. Again this
8663 -- change is skipped if we have a change of representation.
8665 elsif Has_Discriminants (Target_Type)
8666 and then Is_Constrained (Target_Type)
8668 Apply_Discriminant_Check (Operand, Target_Type);
8669 Handle_Changed_Representation;
8671 -- Case of all other record conversions. The only processing required
8672 -- is to check for a change of representation requiring the special
8673 -- assignment processing.
8675 elsif Is_Record_Type (Target_Type) then
8677 -- Ada 2005 (AI-216): Program_Error is raised when converting from
8678 -- a derived Unchecked_Union type to an unconstrained type that is
8679 -- not Unchecked_Union if the operand lacks inferable discriminants.
8681 if Is_Derived_Type (Operand_Type)
8682 and then Is_Unchecked_Union (Base_Type (Operand_Type))
8683 and then not Is_Constrained (Target_Type)
8684 and then not Is_Unchecked_Union (Base_Type (Target_Type))
8685 and then not Has_Inferable_Discriminants (Operand)
8687 -- To prevent Gigi from generating illegal code, we generate a
8688 -- Program_Error node, but we give it the target type of the
8692 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
8693 Reason => PE_Unchecked_Union_Restriction);
8696 Set_Etype (PE, Target_Type);
8701 Handle_Changed_Representation;
8704 -- Case of conversions of enumeration types
8706 elsif Is_Enumeration_Type (Target_Type) then
8708 -- Special processing is required if there is a change of
8709 -- representation (from enumeration representation clauses).
8711 if not Same_Representation (Target_Type, Operand_Type) then
8713 -- Convert: x(y) to x'val (ytyp'val (y))
8716 Make_Attribute_Reference (Loc,
8717 Prefix => New_Occurrence_Of (Target_Type, Loc),
8718 Attribute_Name => Name_Val,
8719 Expressions => New_List (
8720 Make_Attribute_Reference (Loc,
8721 Prefix => New_Occurrence_Of (Operand_Type, Loc),
8722 Attribute_Name => Name_Pos,
8723 Expressions => New_List (Operand)))));
8725 Analyze_And_Resolve (N, Target_Type);
8728 -- Case of conversions to floating-point
8730 elsif Is_Floating_Point_Type (Target_Type) then
8734 -- At this stage, either the conversion node has been transformed into
8735 -- some other equivalent expression, or left as a conversion that can be
8736 -- handled by Gigi, in the following cases:
8738 -- Conversions with no change of representation or type
8740 -- Numeric conversions involving integer, floating- and fixed-point
8741 -- values. Fixed-point values are allowed only if Conversion_OK is
8742 -- set, i.e. if the fixed-point values are to be treated as integers.
8744 -- No other conversions should be passed to Gigi
8746 -- Check: are these rules stated in sinfo??? if so, why restate here???
8748 -- The only remaining step is to generate a range check if we still have
8749 -- a type conversion at this stage and Do_Range_Check is set. For now we
8750 -- do this only for conversions of discrete types.
8752 if Nkind (N) = N_Type_Conversion
8753 and then Is_Discrete_Type (Etype (N))
8756 Expr : constant Node_Id := Expression (N);
8761 if Do_Range_Check (Expr)
8762 and then Is_Discrete_Type (Etype (Expr))
8764 Set_Do_Range_Check (Expr, False);
8766 -- Before we do a range check, we have to deal with treating a
8767 -- fixed-point operand as an integer. The way we do this is
8768 -- simply to do an unchecked conversion to an appropriate
8769 -- integer type large enough to hold the result.
8771 -- This code is not active yet, because we are only dealing
8772 -- with discrete types so far ???
8774 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
8775 and then Treat_Fixed_As_Integer (Expr)
8777 Ftyp := Base_Type (Etype (Expr));
8779 if Esize (Ftyp) >= Esize (Standard_Integer) then
8780 Ityp := Standard_Long_Long_Integer;
8782 Ityp := Standard_Integer;
8785 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
8788 -- Reset overflow flag, since the range check will include
8789 -- dealing with possible overflow, and generate the check. If
8790 -- Address is either a source type or target type, suppress
8791 -- range check to avoid typing anomalies when it is a visible
8794 Set_Do_Overflow_Check (N, False);
8795 if not Is_Descendent_Of_Address (Etype (Expr))
8796 and then not Is_Descendent_Of_Address (Target_Type)
8798 Generate_Range_Check
8799 (Expr, Target_Type, CE_Range_Check_Failed);
8805 -- Final step, if the result is a type conversion involving Vax_Float
8806 -- types, then it is subject for further special processing.
8808 if Nkind (N) = N_Type_Conversion
8809 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
8811 Expand_Vax_Conversion (N);
8815 -- Here at end of processing
8819 end Expand_N_Type_Conversion;
8821 -----------------------------------
8822 -- Expand_N_Unchecked_Expression --
8823 -----------------------------------
8825 -- Remove the unchecked expression node from the tree. Its job was simply
8826 -- to make sure that its constituent expression was handled with checks
8827 -- off, and now that that is done, we can remove it from the tree, and
8828 -- indeed must, since Gigi does not expect to see these nodes.
8830 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
8831 Exp : constant Node_Id := Expression (N);
8833 Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
8835 end Expand_N_Unchecked_Expression;
8837 ----------------------------------------
8838 -- Expand_N_Unchecked_Type_Conversion --
8839 ----------------------------------------
8841 -- If this cannot be handled by Gigi and we haven't already made a
8842 -- temporary for it, do it now.
8844 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
8845 Target_Type : constant Entity_Id := Etype (N);
8846 Operand : constant Node_Id := Expression (N);
8847 Operand_Type : constant Entity_Id := Etype (Operand);
8850 -- Nothing at all to do if conversion is to the identical type so remove
8851 -- the conversion completely, it is useless, except that it may carry
8852 -- an Assignment_OK indication which must be propagated to the operand.
8854 if Operand_Type = Target_Type then
8856 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
8858 if Assignment_OK (N) then
8859 Set_Assignment_OK (Operand);
8862 Rewrite (N, Relocate_Node (Operand));
8866 -- If we have a conversion of a compile time known value to a target
8867 -- type and the value is in range of the target type, then we can simply
8868 -- replace the construct by an integer literal of the correct type. We
8869 -- only apply this to integer types being converted. Possibly it may
8870 -- apply in other cases, but it is too much trouble to worry about.
8872 -- Note that we do not do this transformation if the Kill_Range_Check
8873 -- flag is set, since then the value may be outside the expected range.
8874 -- This happens in the Normalize_Scalars case.
8876 -- We also skip this if either the target or operand type is biased
8877 -- because in this case, the unchecked conversion is supposed to
8878 -- preserve the bit pattern, not the integer value.
8880 if Is_Integer_Type (Target_Type)
8881 and then not Has_Biased_Representation (Target_Type)
8882 and then Is_Integer_Type (Operand_Type)
8883 and then not Has_Biased_Representation (Operand_Type)
8884 and then Compile_Time_Known_Value (Operand)
8885 and then not Kill_Range_Check (N)
8888 Val : constant Uint := Expr_Value (Operand);
8891 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
8893 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
8895 Val >= Expr_Value (Type_Low_Bound (Target_Type))
8897 Val <= Expr_Value (Type_High_Bound (Target_Type))
8899 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
8901 -- If Address is the target type, just set the type to avoid a
8902 -- spurious type error on the literal when Address is a visible
8905 if Is_Descendent_Of_Address (Target_Type) then
8906 Set_Etype (N, Target_Type);
8908 Analyze_And_Resolve (N, Target_Type);
8916 -- Nothing to do if conversion is safe
8918 if Safe_Unchecked_Type_Conversion (N) then
8922 -- Otherwise force evaluation unless Assignment_OK flag is set (this
8923 -- flag indicates ??? -- more comments needed here)
8925 if Assignment_OK (N) then
8928 Force_Evaluation (N);
8930 end Expand_N_Unchecked_Type_Conversion;
8932 ----------------------------
8933 -- Expand_Record_Equality --
8934 ----------------------------
8936 -- For non-variant records, Equality is expanded when needed into:
8938 -- and then Lhs.Discr1 = Rhs.Discr1
8940 -- and then Lhs.Discrn = Rhs.Discrn
8941 -- and then Lhs.Cmp1 = Rhs.Cmp1
8943 -- and then Lhs.Cmpn = Rhs.Cmpn
8945 -- The expression is folded by the back-end for adjacent fields. This
8946 -- function is called for tagged record in only one occasion: for imple-
8947 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
8948 -- otherwise the primitive "=" is used directly.
8950 function Expand_Record_Equality
8955 Bodies : List_Id) return Node_Id
8957 Loc : constant Source_Ptr := Sloc (Nod);
8962 First_Time : Boolean := True;
8964 function Suitable_Element (C : Entity_Id) return Entity_Id;
8965 -- Return the first field to compare beginning with C, skipping the
8966 -- inherited components.
8968 ----------------------
8969 -- Suitable_Element --
8970 ----------------------
8972 function Suitable_Element (C : Entity_Id) return Entity_Id is
8977 elsif Ekind (C) /= E_Discriminant
8978 and then Ekind (C) /= E_Component
8980 return Suitable_Element (Next_Entity (C));
8982 elsif Is_Tagged_Type (Typ)
8983 and then C /= Original_Record_Component (C)
8985 return Suitable_Element (Next_Entity (C));
8987 elsif Chars (C) = Name_uController
8988 or else Chars (C) = Name_uTag
8990 return Suitable_Element (Next_Entity (C));
8992 elsif Is_Interface (Etype (C)) then
8993 return Suitable_Element (Next_Entity (C));
8998 end Suitable_Element;
9000 -- Start of processing for Expand_Record_Equality
9003 -- Generates the following code: (assuming that Typ has one Discr and
9004 -- component C2 is also a record)
9007 -- and then Lhs.Discr1 = Rhs.Discr1
9008 -- and then Lhs.C1 = Rhs.C1
9009 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
9011 -- and then Lhs.Cmpn = Rhs.Cmpn
9013 Result := New_Reference_To (Standard_True, Loc);
9014 C := Suitable_Element (First_Entity (Typ));
9015 while Present (C) loop
9023 First_Time := False;
9027 New_Lhs := New_Copy_Tree (Lhs);
9028 New_Rhs := New_Copy_Tree (Rhs);
9032 Expand_Composite_Equality (Nod, Etype (C),
9034 Make_Selected_Component (Loc,
9036 Selector_Name => New_Reference_To (C, Loc)),
9038 Make_Selected_Component (Loc,
9040 Selector_Name => New_Reference_To (C, Loc)),
9043 -- If some (sub)component is an unchecked_union, the whole
9044 -- operation will raise program error.
9046 if Nkind (Check) = N_Raise_Program_Error then
9048 Set_Etype (Result, Standard_Boolean);
9053 Left_Opnd => Result,
9054 Right_Opnd => Check);
9058 C := Suitable_Element (Next_Entity (C));
9062 end Expand_Record_Equality;
9064 -----------------------------------
9065 -- Expand_Short_Circuit_Operator --
9066 -----------------------------------
9068 -- Deal with special expansion if actions are present for the right operand
9069 -- and deal with optimizing case of arguments being True or False. We also
9070 -- deal with the special case of non-standard boolean values.
9072 procedure Expand_Short_Circuit_Operator (N : Node_Id) is
9073 Loc : constant Source_Ptr := Sloc (N);
9074 Typ : constant Entity_Id := Etype (N);
9075 Left : constant Node_Id := Left_Opnd (N);
9076 Right : constant Node_Id := Right_Opnd (N);
9077 LocR : constant Source_Ptr := Sloc (Right);
9080 Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
9081 Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
9082 -- If Left = Shortcut_Value then Right need not be evaluated
9084 function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
9085 -- For Opnd a boolean expression, return a Boolean expression equivalent
9086 -- to Opnd /= Shortcut_Value.
9088 --------------------
9089 -- Make_Test_Expr --
9090 --------------------
9092 function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
9094 if Shortcut_Value then
9095 return Make_Op_Not (Sloc (Opnd), Opnd);
9102 -- Entity for a temporary variable holding the value of the operator,
9103 -- used for expansion in the case where actions are present.
9105 -- Start of processing for Expand_Short_Circuit_Operator
9108 -- Deal with non-standard booleans
9110 if Is_Boolean_Type (Typ) then
9111 Adjust_Condition (Left);
9112 Adjust_Condition (Right);
9113 Set_Etype (N, Standard_Boolean);
9116 -- Check for cases where left argument is known to be True or False
9118 if Compile_Time_Known_Value (Left) then
9120 -- Mark SCO for left condition as compile time known
9122 if Generate_SCO and then Comes_From_Source (Left) then
9123 Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
9126 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
9127 -- Any actions associated with Right will be executed unconditionally
9128 -- and can thus be inserted into the tree unconditionally.
9130 if Expr_Value_E (Left) /= Shortcut_Ent then
9131 if Present (Actions (N)) then
9132 Insert_Actions (N, Actions (N));
9137 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
9138 -- In this case we can forget the actions associated with Right,
9139 -- since they will never be executed.
9142 Kill_Dead_Code (Right);
9143 Kill_Dead_Code (Actions (N));
9144 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9147 Adjust_Result_Type (N, Typ);
9151 -- If Actions are present for the right operand, we have to do some
9152 -- special processing. We can't just let these actions filter back into
9153 -- code preceding the short circuit (which is what would have happened
9154 -- if we had not trapped them in the short-circuit form), since they
9155 -- must only be executed if the right operand of the short circuit is
9156 -- executed and not otherwise.
9158 -- the temporary variable C.
9160 if Present (Actions (N)) then
9161 Actlist := Actions (N);
9163 -- The old approach is to expand:
9165 -- left AND THEN right
9169 -- C : Boolean := False;
9177 -- and finally rewrite the operator into a reference to C. Similarly
9178 -- for left OR ELSE right, with negated values. Note that this
9179 -- rewrite causes some difficulties for coverage analysis because
9180 -- of the introduction of the new variable C, which obscures the
9181 -- structure of the test.
9183 -- We use this "old approach" if use of N_Expression_With_Actions
9184 -- is False (see description in Opt of when this is or is not set).
9186 if not Use_Expression_With_Actions then
9187 Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
9190 Make_Object_Declaration (Loc,
9191 Defining_Identifier =>
9193 Object_Definition =>
9194 New_Occurrence_Of (Standard_Boolean, Loc),
9196 New_Occurrence_Of (Shortcut_Ent, Loc)));
9199 Make_Implicit_If_Statement (Right,
9200 Condition => Make_Test_Expr (Right),
9201 Then_Statements => New_List (
9202 Make_Assignment_Statement (LocR,
9203 Name => New_Occurrence_Of (Op_Var, LocR),
9206 (Boolean_Literals (not Shortcut_Value), LocR)))));
9209 Make_Implicit_If_Statement (Left,
9210 Condition => Make_Test_Expr (Left),
9211 Then_Statements => Actlist));
9213 Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
9214 Analyze_And_Resolve (N, Standard_Boolean);
9216 -- The new approach, activated for now by the use of debug flag
9217 -- -gnatd.X is to use the new Expression_With_Actions node for the
9218 -- right operand of the short-circuit form. This should solve the
9219 -- traceability problems for coverage analysis.
9223 Make_Expression_With_Actions (LocR,
9224 Expression => Relocate_Node (Right),
9225 Actions => Actlist));
9226 Set_Actions (N, No_List);
9227 Analyze_And_Resolve (Right, Standard_Boolean);
9230 Adjust_Result_Type (N, Typ);
9234 -- No actions present, check for cases of right argument True/False
9236 if Compile_Time_Known_Value (Right) then
9238 -- Mark SCO for left condition as compile time known
9240 if Generate_SCO and then Comes_From_Source (Right) then
9241 Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
9244 -- Change (Left and then True), (Left or else False) to Left.
9245 -- Note that we know there are no actions associated with the right
9246 -- operand, since we just checked for this case above.
9248 if Expr_Value_E (Right) /= Shortcut_Ent then
9251 -- Change (Left and then False), (Left or else True) to Right,
9252 -- making sure to preserve any side effects associated with the Left
9256 Remove_Side_Effects (Left);
9257 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9261 Adjust_Result_Type (N, Typ);
9262 end Expand_Short_Circuit_Operator;
9264 -------------------------------------
9265 -- Fixup_Universal_Fixed_Operation --
9266 -------------------------------------
9268 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
9269 Conv : constant Node_Id := Parent (N);
9272 -- We must have a type conversion immediately above us
9274 pragma Assert (Nkind (Conv) = N_Type_Conversion);
9276 -- Normally the type conversion gives our target type. The exception
9277 -- occurs in the case of the Round attribute, where the conversion
9278 -- will be to universal real, and our real type comes from the Round
9279 -- attribute (as well as an indication that we must round the result)
9281 if Nkind (Parent (Conv)) = N_Attribute_Reference
9282 and then Attribute_Name (Parent (Conv)) = Name_Round
9284 Set_Etype (N, Etype (Parent (Conv)));
9285 Set_Rounded_Result (N);
9287 -- Normal case where type comes from conversion above us
9290 Set_Etype (N, Etype (Conv));
9292 end Fixup_Universal_Fixed_Operation;
9294 ------------------------------
9295 -- Get_Allocator_Final_List --
9296 ------------------------------
9298 function Get_Allocator_Final_List
9301 PtrT : Entity_Id) return Entity_Id
9303 Loc : constant Source_Ptr := Sloc (N);
9305 Owner : Entity_Id := PtrT;
9306 -- The entity whose finalization list must be used to attach the
9307 -- allocated object.
9310 if Ekind (PtrT) = E_Anonymous_Access_Type then
9312 -- If the context is an access parameter, we need to create a
9313 -- non-anonymous access type in order to have a usable final list,
9314 -- because there is otherwise no pool to which the allocated object
9315 -- can belong. We create both the type and the finalization chain
9316 -- here, because freezing an internal type does not create such a
9317 -- chain. The Final_Chain that is thus created is shared by the
9318 -- access parameter. The access type is tested against the result
9319 -- type of the function to exclude allocators whose type is an
9320 -- anonymous access result type. We freeze the type at once to
9321 -- ensure that it is properly decorated for the back-end, even
9322 -- if the context and current scope is a loop.
9324 if Nkind (Associated_Node_For_Itype (PtrT))
9325 in N_Subprogram_Specification
9328 Etype (Defining_Unit_Name (Associated_Node_For_Itype (PtrT)))
9330 Owner := Make_Temporary (Loc, 'J');
9332 Make_Full_Type_Declaration (Loc,
9333 Defining_Identifier => Owner,
9335 Make_Access_To_Object_Definition (Loc,
9336 Subtype_Indication =>
9337 New_Occurrence_Of (T, Loc))));
9339 Freeze_Before (N, Owner);
9340 Build_Final_List (N, Owner);
9341 Set_Associated_Final_Chain (PtrT, Associated_Final_Chain (Owner));
9343 -- Ada 2005 (AI-318-02): If the context is a return object
9344 -- declaration, then the anonymous return subtype is defined to have
9345 -- the same accessibility level as that of the function's result
9346 -- subtype, which means that we want the scope where the function is
9349 elsif Nkind (Associated_Node_For_Itype (PtrT)) = N_Object_Declaration
9350 and then Ekind (Scope (PtrT)) = E_Return_Statement
9352 Owner := Scope (Return_Applies_To (Scope (PtrT)));
9354 -- Case of an access discriminant, or (Ada 2005) of an anonymous
9355 -- access component or anonymous access function result: find the
9356 -- final list associated with the scope of the type. (In the
9357 -- anonymous access component kind, a list controller will have
9358 -- been allocated when freezing the record type, and PtrT has an
9359 -- Associated_Final_Chain attribute designating it.)
9361 elsif No (Associated_Final_Chain (PtrT)) then
9362 Owner := Scope (PtrT);
9366 return Find_Final_List (Owner);
9367 end Get_Allocator_Final_List;
9369 ---------------------------------
9370 -- Has_Inferable_Discriminants --
9371 ---------------------------------
9373 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
9375 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
9376 -- Determines whether the left-most prefix of a selected component is a
9377 -- formal parameter in a subprogram. Assumes N is a selected component.
9379 --------------------------------
9380 -- Prefix_Is_Formal_Parameter --
9381 --------------------------------
9383 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
9384 Sel_Comp : Node_Id := N;
9387 -- Move to the left-most prefix by climbing up the tree
9389 while Present (Parent (Sel_Comp))
9390 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
9392 Sel_Comp := Parent (Sel_Comp);
9395 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
9396 end Prefix_Is_Formal_Parameter;
9398 -- Start of processing for Has_Inferable_Discriminants
9401 -- For identifiers and indexed components, it is sufficient to have a
9402 -- constrained Unchecked_Union nominal subtype.
9404 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
9405 return Is_Unchecked_Union (Base_Type (Etype (N)))
9407 Is_Constrained (Etype (N));
9409 -- For selected components, the subtype of the selector must be a
9410 -- constrained Unchecked_Union. If the component is subject to a
9411 -- per-object constraint, then the enclosing object must have inferable
9414 elsif Nkind (N) = N_Selected_Component then
9415 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
9417 -- A small hack. If we have a per-object constrained selected
9418 -- component of a formal parameter, return True since we do not
9419 -- know the actual parameter association yet.
9421 if Prefix_Is_Formal_Parameter (N) then
9425 -- Otherwise, check the enclosing object and the selector
9427 return Has_Inferable_Discriminants (Prefix (N))
9429 Has_Inferable_Discriminants (Selector_Name (N));
9432 -- The call to Has_Inferable_Discriminants will determine whether
9433 -- the selector has a constrained Unchecked_Union nominal type.
9435 return Has_Inferable_Discriminants (Selector_Name (N));
9437 -- A qualified expression has inferable discriminants if its subtype
9438 -- mark is a constrained Unchecked_Union subtype.
9440 elsif Nkind (N) = N_Qualified_Expression then
9441 return Is_Unchecked_Union (Subtype_Mark (N))
9443 Is_Constrained (Subtype_Mark (N));
9448 end Has_Inferable_Discriminants;
9450 -------------------------------
9451 -- Insert_Dereference_Action --
9452 -------------------------------
9454 procedure Insert_Dereference_Action (N : Node_Id) is
9455 Loc : constant Source_Ptr := Sloc (N);
9456 Typ : constant Entity_Id := Etype (N);
9457 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
9458 Pnod : constant Node_Id := Parent (N);
9460 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
9461 -- Return true if type of P is derived from Checked_Pool;
9463 -----------------------------
9464 -- Is_Checked_Storage_Pool --
9465 -----------------------------
9467 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
9476 while T /= Etype (T) loop
9477 if Is_RTE (T, RE_Checked_Pool) then
9485 end Is_Checked_Storage_Pool;
9487 -- Start of processing for Insert_Dereference_Action
9490 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
9492 if not (Is_Checked_Storage_Pool (Pool)
9493 and then Comes_From_Source (Original_Node (Pnod)))
9499 Make_Procedure_Call_Statement (Loc,
9500 Name => New_Reference_To (
9501 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
9503 Parameter_Associations => New_List (
9507 New_Reference_To (Pool, Loc),
9509 -- Storage_Address. We use the attribute Pool_Address, which uses
9510 -- the pointer itself to find the address of the object, and which
9511 -- handles unconstrained arrays properly by computing the address
9512 -- of the template. i.e. the correct address of the corresponding
9515 Make_Attribute_Reference (Loc,
9516 Prefix => Duplicate_Subexpr_Move_Checks (N),
9517 Attribute_Name => Name_Pool_Address),
9519 -- Size_In_Storage_Elements
9521 Make_Op_Divide (Loc,
9523 Make_Attribute_Reference (Loc,
9525 Make_Explicit_Dereference (Loc,
9526 Duplicate_Subexpr_Move_Checks (N)),
9527 Attribute_Name => Name_Size),
9529 Make_Integer_Literal (Loc, System_Storage_Unit)),
9533 Make_Attribute_Reference (Loc,
9535 Make_Explicit_Dereference (Loc,
9536 Duplicate_Subexpr_Move_Checks (N)),
9537 Attribute_Name => Name_Alignment))));
9540 when RE_Not_Available =>
9542 end Insert_Dereference_Action;
9544 --------------------------------
9545 -- Integer_Promotion_Possible --
9546 --------------------------------
9548 function Integer_Promotion_Possible (N : Node_Id) return Boolean is
9549 Operand : constant Node_Id := Expression (N);
9550 Operand_Type : constant Entity_Id := Etype (Operand);
9551 Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
9554 pragma Assert (Nkind (N) = N_Type_Conversion);
9558 -- We only do the transformation for source constructs. We assume
9559 -- that the expander knows what it is doing when it generates code.
9561 Comes_From_Source (N)
9563 -- If the operand type is Short_Integer or Short_Short_Integer,
9564 -- then we will promote to Integer, which is available on all
9565 -- targets, and is sufficient to ensure no intermediate overflow.
9566 -- Furthermore it is likely to be as efficient or more efficient
9567 -- than using the smaller type for the computation so we do this
9571 (Root_Operand_Type = Base_Type (Standard_Short_Integer)
9573 Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
9575 -- Test for interesting operation, which includes addition,
9576 -- division, exponentiation, multiplication, subtraction, absolute
9577 -- value and unary negation. Unary "+" is omitted since it is a
9578 -- no-op and thus can't overflow.
9580 and then Nkind_In (Operand, N_Op_Abs,
9587 end Integer_Promotion_Possible;
9589 ------------------------------
9590 -- Make_Array_Comparison_Op --
9591 ------------------------------
9593 -- This is a hand-coded expansion of the following generic function:
9596 -- type elem is (<>);
9597 -- type index is (<>);
9598 -- type a is array (index range <>) of elem;
9600 -- function Gnnn (X : a; Y: a) return boolean is
9601 -- J : index := Y'first;
9604 -- if X'length = 0 then
9607 -- elsif Y'length = 0 then
9611 -- for I in X'range loop
9612 -- if X (I) = Y (J) then
9613 -- if J = Y'last then
9616 -- J := index'succ (J);
9620 -- return X (I) > Y (J);
9624 -- return X'length > Y'length;
9628 -- Note that since we are essentially doing this expansion by hand, we
9629 -- do not need to generate an actual or formal generic part, just the
9630 -- instantiated function itself.
9632 function Make_Array_Comparison_Op
9634 Nod : Node_Id) return Node_Id
9636 Loc : constant Source_Ptr := Sloc (Nod);
9638 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
9639 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
9640 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
9641 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
9643 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
9645 Loop_Statement : Node_Id;
9646 Loop_Body : Node_Id;
9649 Final_Expr : Node_Id;
9650 Func_Body : Node_Id;
9651 Func_Name : Entity_Id;
9657 -- if J = Y'last then
9660 -- J := index'succ (J);
9664 Make_Implicit_If_Statement (Nod,
9667 Left_Opnd => New_Reference_To (J, Loc),
9669 Make_Attribute_Reference (Loc,
9670 Prefix => New_Reference_To (Y, Loc),
9671 Attribute_Name => Name_Last)),
9673 Then_Statements => New_List (
9674 Make_Exit_Statement (Loc)),
9678 Make_Assignment_Statement (Loc,
9679 Name => New_Reference_To (J, Loc),
9681 Make_Attribute_Reference (Loc,
9682 Prefix => New_Reference_To (Index, Loc),
9683 Attribute_Name => Name_Succ,
9684 Expressions => New_List (New_Reference_To (J, Loc))))));
9686 -- if X (I) = Y (J) then
9689 -- return X (I) > Y (J);
9693 Make_Implicit_If_Statement (Nod,
9697 Make_Indexed_Component (Loc,
9698 Prefix => New_Reference_To (X, Loc),
9699 Expressions => New_List (New_Reference_To (I, Loc))),
9702 Make_Indexed_Component (Loc,
9703 Prefix => New_Reference_To (Y, Loc),
9704 Expressions => New_List (New_Reference_To (J, Loc)))),
9706 Then_Statements => New_List (Inner_If),
9708 Else_Statements => New_List (
9709 Make_Simple_Return_Statement (Loc,
9713 Make_Indexed_Component (Loc,
9714 Prefix => New_Reference_To (X, Loc),
9715 Expressions => New_List (New_Reference_To (I, Loc))),
9718 Make_Indexed_Component (Loc,
9719 Prefix => New_Reference_To (Y, Loc),
9720 Expressions => New_List (
9721 New_Reference_To (J, Loc)))))));
9723 -- for I in X'range loop
9728 Make_Implicit_Loop_Statement (Nod,
9729 Identifier => Empty,
9732 Make_Iteration_Scheme (Loc,
9733 Loop_Parameter_Specification =>
9734 Make_Loop_Parameter_Specification (Loc,
9735 Defining_Identifier => I,
9736 Discrete_Subtype_Definition =>
9737 Make_Attribute_Reference (Loc,
9738 Prefix => New_Reference_To (X, Loc),
9739 Attribute_Name => Name_Range))),
9741 Statements => New_List (Loop_Body));
9743 -- if X'length = 0 then
9745 -- elsif Y'length = 0 then
9748 -- for ... loop ... end loop;
9749 -- return X'length > Y'length;
9753 Make_Attribute_Reference (Loc,
9754 Prefix => New_Reference_To (X, Loc),
9755 Attribute_Name => Name_Length);
9758 Make_Attribute_Reference (Loc,
9759 Prefix => New_Reference_To (Y, Loc),
9760 Attribute_Name => Name_Length);
9764 Left_Opnd => Length1,
9765 Right_Opnd => Length2);
9768 Make_Implicit_If_Statement (Nod,
9772 Make_Attribute_Reference (Loc,
9773 Prefix => New_Reference_To (X, Loc),
9774 Attribute_Name => Name_Length),
9776 Make_Integer_Literal (Loc, 0)),
9780 Make_Simple_Return_Statement (Loc,
9781 Expression => New_Reference_To (Standard_False, Loc))),
9783 Elsif_Parts => New_List (
9784 Make_Elsif_Part (Loc,
9788 Make_Attribute_Reference (Loc,
9789 Prefix => New_Reference_To (Y, Loc),
9790 Attribute_Name => Name_Length),
9792 Make_Integer_Literal (Loc, 0)),
9796 Make_Simple_Return_Statement (Loc,
9797 Expression => New_Reference_To (Standard_True, Loc))))),
9799 Else_Statements => New_List (
9801 Make_Simple_Return_Statement (Loc,
9802 Expression => Final_Expr)));
9806 Formals := New_List (
9807 Make_Parameter_Specification (Loc,
9808 Defining_Identifier => X,
9809 Parameter_Type => New_Reference_To (Typ, Loc)),
9811 Make_Parameter_Specification (Loc,
9812 Defining_Identifier => Y,
9813 Parameter_Type => New_Reference_To (Typ, Loc)));
9815 -- function Gnnn (...) return boolean is
9816 -- J : index := Y'first;
9821 Func_Name := Make_Temporary (Loc, 'G');
9824 Make_Subprogram_Body (Loc,
9826 Make_Function_Specification (Loc,
9827 Defining_Unit_Name => Func_Name,
9828 Parameter_Specifications => Formals,
9829 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
9831 Declarations => New_List (
9832 Make_Object_Declaration (Loc,
9833 Defining_Identifier => J,
9834 Object_Definition => New_Reference_To (Index, Loc),
9836 Make_Attribute_Reference (Loc,
9837 Prefix => New_Reference_To (Y, Loc),
9838 Attribute_Name => Name_First))),
9840 Handled_Statement_Sequence =>
9841 Make_Handled_Sequence_Of_Statements (Loc,
9842 Statements => New_List (If_Stat)));
9845 end Make_Array_Comparison_Op;
9847 ---------------------------
9848 -- Make_Boolean_Array_Op --
9849 ---------------------------
9851 -- For logical operations on boolean arrays, expand in line the following,
9852 -- replacing 'and' with 'or' or 'xor' where needed:
9854 -- function Annn (A : typ; B: typ) return typ is
9857 -- for J in A'range loop
9858 -- C (J) := A (J) op B (J);
9863 -- Here typ is the boolean array type
9865 function Make_Boolean_Array_Op
9867 N : Node_Id) return Node_Id
9869 Loc : constant Source_Ptr := Sloc (N);
9871 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
9872 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
9873 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
9874 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
9882 Func_Name : Entity_Id;
9883 Func_Body : Node_Id;
9884 Loop_Statement : Node_Id;
9888 Make_Indexed_Component (Loc,
9889 Prefix => New_Reference_To (A, Loc),
9890 Expressions => New_List (New_Reference_To (J, Loc)));
9893 Make_Indexed_Component (Loc,
9894 Prefix => New_Reference_To (B, Loc),
9895 Expressions => New_List (New_Reference_To (J, Loc)));
9898 Make_Indexed_Component (Loc,
9899 Prefix => New_Reference_To (C, Loc),
9900 Expressions => New_List (New_Reference_To (J, Loc)));
9902 if Nkind (N) = N_Op_And then
9908 elsif Nkind (N) = N_Op_Or then
9922 Make_Implicit_Loop_Statement (N,
9923 Identifier => Empty,
9926 Make_Iteration_Scheme (Loc,
9927 Loop_Parameter_Specification =>
9928 Make_Loop_Parameter_Specification (Loc,
9929 Defining_Identifier => J,
9930 Discrete_Subtype_Definition =>
9931 Make_Attribute_Reference (Loc,
9932 Prefix => New_Reference_To (A, Loc),
9933 Attribute_Name => Name_Range))),
9935 Statements => New_List (
9936 Make_Assignment_Statement (Loc,
9938 Expression => Op)));
9940 Formals := New_List (
9941 Make_Parameter_Specification (Loc,
9942 Defining_Identifier => A,
9943 Parameter_Type => New_Reference_To (Typ, Loc)),
9945 Make_Parameter_Specification (Loc,
9946 Defining_Identifier => B,
9947 Parameter_Type => New_Reference_To (Typ, Loc)));
9949 Func_Name := Make_Temporary (Loc, 'A');
9950 Set_Is_Inlined (Func_Name);
9953 Make_Subprogram_Body (Loc,
9955 Make_Function_Specification (Loc,
9956 Defining_Unit_Name => Func_Name,
9957 Parameter_Specifications => Formals,
9958 Result_Definition => New_Reference_To (Typ, Loc)),
9960 Declarations => New_List (
9961 Make_Object_Declaration (Loc,
9962 Defining_Identifier => C,
9963 Object_Definition => New_Reference_To (Typ, Loc))),
9965 Handled_Statement_Sequence =>
9966 Make_Handled_Sequence_Of_Statements (Loc,
9967 Statements => New_List (
9969 Make_Simple_Return_Statement (Loc,
9970 Expression => New_Reference_To (C, Loc)))));
9973 end Make_Boolean_Array_Op;
9975 ------------------------
9976 -- Rewrite_Comparison --
9977 ------------------------
9979 procedure Rewrite_Comparison (N : Node_Id) is
9980 Warning_Generated : Boolean := False;
9981 -- Set to True if first pass with Assume_Valid generates a warning in
9982 -- which case we skip the second pass to avoid warning overloaded.
9985 -- Set to Standard_True or Standard_False
9988 if Nkind (N) = N_Type_Conversion then
9989 Rewrite_Comparison (Expression (N));
9992 elsif Nkind (N) not in N_Op_Compare then
9996 -- Now start looking at the comparison in detail. We potentially go
9997 -- through this loop twice. The first time, Assume_Valid is set False
9998 -- in the call to Compile_Time_Compare. If this call results in a
9999 -- clear result of always True or Always False, that's decisive and
10000 -- we are done. Otherwise we repeat the processing with Assume_Valid
10001 -- set to True to generate additional warnings. We can skip that step
10002 -- if Constant_Condition_Warnings is False.
10004 for AV in False .. True loop
10006 Typ : constant Entity_Id := Etype (N);
10007 Op1 : constant Node_Id := Left_Opnd (N);
10008 Op2 : constant Node_Id := Right_Opnd (N);
10010 Res : constant Compare_Result :=
10011 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
10012 -- Res indicates if compare outcome can be compile time determined
10014 True_Result : Boolean;
10015 False_Result : Boolean;
10018 case N_Op_Compare (Nkind (N)) is
10020 True_Result := Res = EQ;
10021 False_Result := Res = LT or else Res = GT or else Res = NE;
10024 True_Result := Res in Compare_GE;
10025 False_Result := Res = LT;
10028 and then Constant_Condition_Warnings
10029 and then Comes_From_Source (Original_Node (N))
10030 and then Nkind (Original_Node (N)) = N_Op_Ge
10031 and then not In_Instance
10032 and then Is_Integer_Type (Etype (Left_Opnd (N)))
10033 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
10036 ("can never be greater than, could replace by ""'=""?", N);
10037 Warning_Generated := True;
10041 True_Result := Res = GT;
10042 False_Result := Res in Compare_LE;
10045 True_Result := Res = LT;
10046 False_Result := Res in Compare_GE;
10049 True_Result := Res in Compare_LE;
10050 False_Result := Res = GT;
10053 and then Constant_Condition_Warnings
10054 and then Comes_From_Source (Original_Node (N))
10055 and then Nkind (Original_Node (N)) = N_Op_Le
10056 and then not In_Instance
10057 and then Is_Integer_Type (Etype (Left_Opnd (N)))
10058 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
10061 ("can never be less than, could replace by ""'=""?", N);
10062 Warning_Generated := True;
10066 True_Result := Res = NE or else Res = GT or else Res = LT;
10067 False_Result := Res = EQ;
10070 -- If this is the first iteration, then we actually convert the
10071 -- comparison into True or False, if the result is certain.
10074 if True_Result or False_Result then
10075 if True_Result then
10076 Result := Standard_True;
10078 Result := Standard_False;
10083 New_Occurrence_Of (Result, Sloc (N))));
10084 Analyze_And_Resolve (N, Typ);
10085 Warn_On_Known_Condition (N);
10089 -- If this is the second iteration (AV = True), and the original
10090 -- node comes from source and we are not in an instance, then give
10091 -- a warning if we know result would be True or False. Note: we
10092 -- know Constant_Condition_Warnings is set if we get here.
10094 elsif Comes_From_Source (Original_Node (N))
10095 and then not In_Instance
10097 if True_Result then
10099 ("condition can only be False if invalid values present?",
10101 elsif False_Result then
10103 ("condition can only be True if invalid values present?",
10109 -- Skip second iteration if not warning on constant conditions or
10110 -- if the first iteration already generated a warning of some kind or
10111 -- if we are in any case assuming all values are valid (so that the
10112 -- first iteration took care of the valid case).
10114 exit when not Constant_Condition_Warnings;
10115 exit when Warning_Generated;
10116 exit when Assume_No_Invalid_Values;
10118 end Rewrite_Comparison;
10120 ----------------------------
10121 -- Safe_In_Place_Array_Op --
10122 ----------------------------
10124 function Safe_In_Place_Array_Op
10127 Op2 : Node_Id) return Boolean
10129 Target : Entity_Id;
10131 function Is_Safe_Operand (Op : Node_Id) return Boolean;
10132 -- Operand is safe if it cannot overlap part of the target of the
10133 -- operation. If the operand and the target are identical, the operand
10134 -- is safe. The operand can be empty in the case of negation.
10136 function Is_Unaliased (N : Node_Id) return Boolean;
10137 -- Check that N is a stand-alone entity
10143 function Is_Unaliased (N : Node_Id) return Boolean is
10147 and then No (Address_Clause (Entity (N)))
10148 and then No (Renamed_Object (Entity (N)));
10151 ---------------------
10152 -- Is_Safe_Operand --
10153 ---------------------
10155 function Is_Safe_Operand (Op : Node_Id) return Boolean is
10160 elsif Is_Entity_Name (Op) then
10161 return Is_Unaliased (Op);
10163 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
10164 return Is_Unaliased (Prefix (Op));
10166 elsif Nkind (Op) = N_Slice then
10168 Is_Unaliased (Prefix (Op))
10169 and then Entity (Prefix (Op)) /= Target;
10171 elsif Nkind (Op) = N_Op_Not then
10172 return Is_Safe_Operand (Right_Opnd (Op));
10177 end Is_Safe_Operand;
10179 -- Start of processing for Is_Safe_In_Place_Array_Op
10182 -- Skip this processing if the component size is different from system
10183 -- storage unit (since at least for NOT this would cause problems).
10185 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
10188 -- Cannot do in place stuff on VM_Target since cannot pass addresses
10190 elsif VM_Target /= No_VM then
10193 -- Cannot do in place stuff if non-standard Boolean representation
10195 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
10198 elsif not Is_Unaliased (Lhs) then
10202 Target := Entity (Lhs);
10203 return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
10205 end Safe_In_Place_Array_Op;
10207 -----------------------
10208 -- Tagged_Membership --
10209 -----------------------
10211 -- There are two different cases to consider depending on whether the right
10212 -- operand is a class-wide type or not. If not we just compare the actual
10213 -- tag of the left expr to the target type tag:
10215 -- Left_Expr.Tag = Right_Type'Tag;
10217 -- If it is a class-wide type we use the RT function CW_Membership which is
10218 -- usually implemented by looking in the ancestor tables contained in the
10219 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
10221 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
10222 -- function IW_Membership which is usually implemented by looking in the
10223 -- table of abstract interface types plus the ancestor table contained in
10224 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
10226 procedure Tagged_Membership
10228 SCIL_Node : out Node_Id;
10229 Result : out Node_Id)
10231 Left : constant Node_Id := Left_Opnd (N);
10232 Right : constant Node_Id := Right_Opnd (N);
10233 Loc : constant Source_Ptr := Sloc (N);
10235 Left_Type : Entity_Id;
10236 New_Node : Node_Id;
10237 Right_Type : Entity_Id;
10241 SCIL_Node := Empty;
10243 -- Handle entities from the limited view
10245 Left_Type := Available_View (Etype (Left));
10246 Right_Type := Available_View (Etype (Right));
10248 if Is_Class_Wide_Type (Left_Type) then
10249 Left_Type := Root_Type (Left_Type);
10253 Make_Selected_Component (Loc,
10254 Prefix => Relocate_Node (Left),
10256 New_Reference_To (First_Tag_Component (Left_Type), Loc));
10258 if Is_Class_Wide_Type (Right_Type) then
10260 -- No need to issue a run-time check if we statically know that the
10261 -- result of this membership test is always true. For example,
10262 -- considering the following declarations:
10264 -- type Iface is interface;
10265 -- type T is tagged null record;
10266 -- type DT is new T and Iface with null record;
10271 -- These membership tests are always true:
10274 -- Obj2 in T'Class;
10275 -- Obj2 in Iface'Class;
10277 -- We do not need to handle cases where the membership is illegal.
10280 -- Obj1 in DT'Class; -- Compile time error
10281 -- Obj1 in Iface'Class; -- Compile time error
10283 if not Is_Class_Wide_Type (Left_Type)
10284 and then (Is_Ancestor (Etype (Right_Type), Left_Type)
10285 or else (Is_Interface (Etype (Right_Type))
10286 and then Interface_Present_In_Ancestor
10288 Iface => Etype (Right_Type))))
10290 Result := New_Reference_To (Standard_True, Loc);
10294 -- Ada 2005 (AI-251): Class-wide applied to interfaces
10296 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
10298 -- Support to: "Iface_CW_Typ in Typ'Class"
10300 or else Is_Interface (Left_Type)
10302 -- Issue error if IW_Membership operation not available in a
10303 -- configurable run time setting.
10305 if not RTE_Available (RE_IW_Membership) then
10307 ("dynamic membership test on interface types", N);
10313 Make_Function_Call (Loc,
10314 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
10315 Parameter_Associations => New_List (
10316 Make_Attribute_Reference (Loc,
10318 Attribute_Name => Name_Address),
10321 (Access_Disp_Table (Root_Type (Right_Type)))),
10324 -- Ada 95: Normal case
10327 Build_CW_Membership (Loc,
10328 Obj_Tag_Node => Obj_Tag,
10332 (Access_Disp_Table (Root_Type (Right_Type)))),
10335 New_Node => New_Node);
10337 -- Generate the SCIL node for this class-wide membership test.
10338 -- Done here because the previous call to Build_CW_Membership
10339 -- relocates Obj_Tag.
10341 if Generate_SCIL then
10342 SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
10343 Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
10344 Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
10347 Result := New_Node;
10350 -- Right_Type is not a class-wide type
10353 -- No need to check the tag of the object if Right_Typ is abstract
10355 if Is_Abstract_Type (Right_Type) then
10356 Result := New_Reference_To (Standard_False, Loc);
10361 Left_Opnd => Obj_Tag,
10364 (Node (First_Elmt (Access_Disp_Table (Right_Type))), Loc));
10367 end Tagged_Membership;
10369 ------------------------------
10370 -- Unary_Op_Validity_Checks --
10371 ------------------------------
10373 procedure Unary_Op_Validity_Checks (N : Node_Id) is
10375 if Validity_Checks_On and Validity_Check_Operands then
10376 Ensure_Valid (Right_Opnd (N));
10378 end Unary_Op_Validity_Checks;