1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 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 Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Aggr; use Exp_Aggr;
32 with Exp_Atag; use Exp_Atag;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Disp; use Exp_Disp;
38 with Exp_Fixd; use Exp_Fixd;
39 with Exp_Pakd; use Exp_Pakd;
40 with Exp_Tss; use Exp_Tss;
41 with Exp_Util; use Exp_Util;
42 with Exp_VFpt; use Exp_VFpt;
43 with Freeze; use Freeze;
44 with Inline; use Inline;
45 with Namet; use Namet;
46 with Nlists; use Nlists;
47 with Nmake; use Nmake;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
53 with Sem_Cat; use Sem_Cat;
54 with Sem_Ch3; use Sem_Ch3;
55 with Sem_Ch8; use Sem_Ch8;
56 with Sem_Ch13; use Sem_Ch13;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Type; use Sem_Type;
60 with Sem_Util; use Sem_Util;
61 with Sem_Warn; use Sem_Warn;
62 with Sinfo; use Sinfo;
63 with Snames; use Snames;
64 with Stand; use Stand;
65 with Targparm; use Targparm;
66 with Tbuild; use Tbuild;
67 with Ttypes; use Ttypes;
68 with Uintp; use Uintp;
69 with Urealp; use Urealp;
70 with Validsw; use Validsw;
72 package body Exp_Ch4 is
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
78 procedure Binary_Op_Validity_Checks (N : Node_Id);
79 pragma Inline (Binary_Op_Validity_Checks);
80 -- Performs validity checks for a binary operator
82 procedure Build_Boolean_Array_Proc_Call
86 -- If a boolean array assignment can be done in place, build call to
87 -- corresponding library procedure.
89 procedure Displace_Allocator_Pointer (N : Node_Id);
90 -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
91 -- Expand_Allocator_Expression. Allocating class-wide interface objects
92 -- this routine displaces the pointer to the allocated object to reference
93 -- the component referencing the corresponding secondary dispatch table.
95 procedure Expand_Allocator_Expression (N : Node_Id);
96 -- Subsidiary to Expand_N_Allocator, for the case when the expression
97 -- is a qualified expression or an aggregate.
99 procedure Expand_Array_Comparison (N : Node_Id);
100 -- This routine handles expansion of the comparison operators (N_Op_Lt,
101 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
102 -- code for these operators is similar, differing only in the details of
103 -- the actual comparison call that is made. Special processing (call a
106 function Expand_Array_Equality
111 Typ : Entity_Id) return Node_Id;
112 -- Expand an array equality into a call to a function implementing this
113 -- equality, and a call to it. Loc is the location for the generated nodes.
114 -- Lhs and Rhs are the array expressions to be compared. Bodies is a list
115 -- on which to attach bodies of local functions that are created in the
116 -- process. It is the responsibility of the caller to insert those bodies
117 -- at the right place. Nod provides the Sloc value for the generated code.
118 -- Normally the types used for the generated equality routine are taken
119 -- from Lhs and Rhs. However, in some situations of generated code, the
120 -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
121 -- the type to be used for the formal parameters.
123 procedure Expand_Boolean_Operator (N : Node_Id);
124 -- Common expansion processing for Boolean operators (And, Or, Xor) for the
125 -- case of array type arguments.
127 function Expand_Composite_Equality
132 Bodies : List_Id) return Node_Id;
133 -- Local recursive function used to expand equality for nested composite
134 -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
135 -- to attach bodies of local functions that are created in the process.
136 -- This is the responsibility of the caller to insert those bodies at the
137 -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs
138 -- are the left and right sides for the comparison, and Typ is the type of
139 -- the arrays to compare.
141 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id);
142 -- Routine to expand concatenation of a sequence of two or more operands
143 -- (in the list Operands) and replace node Cnode with the result of the
144 -- concatenation. The operands can be of any appropriate type, and can
145 -- include both arrays and singleton elements.
147 procedure Fixup_Universal_Fixed_Operation (N : Node_Id);
148 -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
149 -- fixed. We do not have such a type at runtime, so the purpose of this
150 -- routine is to find the real type by looking up the tree. We also
151 -- determine if the operation must be rounded.
153 function Get_Allocator_Final_List
156 PtrT : Entity_Id) return Entity_Id;
157 -- If the designated type is controlled, build final_list expression for
158 -- created object. If context is an access parameter, create a local access
159 -- type to have a usable finalization list.
161 function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
162 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
163 -- discriminants if it has a constrained nominal type, unless the object
164 -- is a component of an enclosing Unchecked_Union object that is subject
165 -- to a per-object constraint and the enclosing object lacks inferable
168 -- An expression of an Unchecked_Union type has inferable discriminants
169 -- if it is either a name of an object with inferable discriminants or a
170 -- qualified expression whose subtype mark denotes a constrained subtype.
172 procedure Insert_Dereference_Action (N : Node_Id);
173 -- N is an expression whose type is an access. When the type of the
174 -- associated storage pool is derived from Checked_Pool, generate a
175 -- call to the 'Dereference' primitive operation.
177 function Make_Array_Comparison_Op
179 Nod : Node_Id) return Node_Id;
180 -- Comparisons between arrays are expanded in line. This function produces
181 -- the body of the implementation of (a > b), where a and b are one-
182 -- dimensional arrays of some discrete type. The original node is then
183 -- expanded into the appropriate call to this function. Nod provides the
184 -- Sloc value for the generated code.
186 function Make_Boolean_Array_Op
188 N : Node_Id) return Node_Id;
189 -- Boolean operations on boolean arrays are expanded in line. This function
190 -- produce the body for the node N, which is (a and b), (a or b), or (a xor
191 -- b). It is used only the normal case and not the packed case. The type
192 -- involved, Typ, is the Boolean array type, and the logical operations in
193 -- the body are simple boolean operations. Note that Typ is always a
194 -- constrained type (the caller has ensured this by using
195 -- Convert_To_Actual_Subtype if necessary).
197 procedure Rewrite_Comparison (N : Node_Id);
198 -- If N is the node for a comparison whose outcome can be determined at
199 -- compile time, then the node N can be rewritten with True or False. If
200 -- the outcome cannot be determined at compile time, the call has no
201 -- effect. If N is a type conversion, then this processing is applied to
202 -- its expression. If N is neither comparison nor a type conversion, the
203 -- call has no effect.
205 function Tagged_Membership (N : Node_Id) return Node_Id;
206 -- Construct the expression corresponding to the tagged membership test.
207 -- Deals with a second operand being (or not) a class-wide type.
209 function Safe_In_Place_Array_Op
212 Op2 : Node_Id) return Boolean;
213 -- In the context of an assignment, where the right-hand side is a boolean
214 -- operation on arrays, check whether operation can be performed in place.
216 procedure Unary_Op_Validity_Checks (N : Node_Id);
217 pragma Inline (Unary_Op_Validity_Checks);
218 -- Performs validity checks for a unary operator
220 -------------------------------
221 -- Binary_Op_Validity_Checks --
222 -------------------------------
224 procedure Binary_Op_Validity_Checks (N : Node_Id) is
226 if Validity_Checks_On and Validity_Check_Operands then
227 Ensure_Valid (Left_Opnd (N));
228 Ensure_Valid (Right_Opnd (N));
230 end Binary_Op_Validity_Checks;
232 ------------------------------------
233 -- Build_Boolean_Array_Proc_Call --
234 ------------------------------------
236 procedure Build_Boolean_Array_Proc_Call
241 Loc : constant Source_Ptr := Sloc (N);
242 Kind : constant Node_Kind := Nkind (Expression (N));
243 Target : constant Node_Id :=
244 Make_Attribute_Reference (Loc,
246 Attribute_Name => Name_Address);
248 Arg1 : constant Node_Id := Op1;
249 Arg2 : Node_Id := Op2;
251 Proc_Name : Entity_Id;
254 if Kind = N_Op_Not then
255 if Nkind (Op1) in N_Binary_Op then
257 -- Use negated version of the binary operators
259 if Nkind (Op1) = N_Op_And then
260 Proc_Name := RTE (RE_Vector_Nand);
262 elsif Nkind (Op1) = N_Op_Or then
263 Proc_Name := RTE (RE_Vector_Nor);
265 else pragma Assert (Nkind (Op1) = N_Op_Xor);
266 Proc_Name := RTE (RE_Vector_Xor);
270 Make_Procedure_Call_Statement (Loc,
271 Name => New_Occurrence_Of (Proc_Name, Loc),
273 Parameter_Associations => New_List (
275 Make_Attribute_Reference (Loc,
276 Prefix => Left_Opnd (Op1),
277 Attribute_Name => Name_Address),
279 Make_Attribute_Reference (Loc,
280 Prefix => Right_Opnd (Op1),
281 Attribute_Name => Name_Address),
283 Make_Attribute_Reference (Loc,
284 Prefix => Left_Opnd (Op1),
285 Attribute_Name => Name_Length)));
288 Proc_Name := RTE (RE_Vector_Not);
291 Make_Procedure_Call_Statement (Loc,
292 Name => New_Occurrence_Of (Proc_Name, Loc),
293 Parameter_Associations => New_List (
296 Make_Attribute_Reference (Loc,
298 Attribute_Name => Name_Address),
300 Make_Attribute_Reference (Loc,
302 Attribute_Name => Name_Length)));
306 -- We use the following equivalences:
308 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
309 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
310 -- (not X) xor (not Y) = X xor Y
311 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
313 if Nkind (Op1) = N_Op_Not then
314 if Kind = N_Op_And then
315 Proc_Name := RTE (RE_Vector_Nor);
317 elsif Kind = N_Op_Or then
318 Proc_Name := RTE (RE_Vector_Nand);
321 Proc_Name := RTE (RE_Vector_Xor);
325 if Kind = N_Op_And then
326 Proc_Name := RTE (RE_Vector_And);
328 elsif Kind = N_Op_Or then
329 Proc_Name := RTE (RE_Vector_Or);
331 elsif Nkind (Op2) = N_Op_Not then
332 Proc_Name := RTE (RE_Vector_Nxor);
333 Arg2 := Right_Opnd (Op2);
336 Proc_Name := RTE (RE_Vector_Xor);
341 Make_Procedure_Call_Statement (Loc,
342 Name => New_Occurrence_Of (Proc_Name, Loc),
343 Parameter_Associations => New_List (
345 Make_Attribute_Reference (Loc,
347 Attribute_Name => Name_Address),
348 Make_Attribute_Reference (Loc,
350 Attribute_Name => Name_Address),
351 Make_Attribute_Reference (Loc,
353 Attribute_Name => Name_Length)));
356 Rewrite (N, Call_Node);
360 when RE_Not_Available =>
362 end Build_Boolean_Array_Proc_Call;
364 --------------------------------
365 -- Displace_Allocator_Pointer --
366 --------------------------------
368 procedure Displace_Allocator_Pointer (N : Node_Id) is
369 Loc : constant Source_Ptr := Sloc (N);
370 Orig_Node : constant Node_Id := Original_Node (N);
376 -- Do nothing in case of VM targets: the virtual machine will handle
377 -- interfaces directly.
379 if VM_Target /= No_VM then
383 pragma Assert (Nkind (N) = N_Identifier
384 and then Nkind (Orig_Node) = N_Allocator);
386 PtrT := Etype (Orig_Node);
387 Dtyp := Designated_Type (PtrT);
388 Etyp := Etype (Expression (Orig_Node));
390 if Is_Class_Wide_Type (Dtyp)
391 and then Is_Interface (Dtyp)
393 -- If the type of the allocator expression is not an interface type
394 -- we can generate code to reference the record component containing
395 -- the pointer to the secondary dispatch table.
397 if not Is_Interface (Etyp) then
399 Saved_Typ : constant Entity_Id := Etype (Orig_Node);
402 -- 1) Get access to the allocated object
405 Make_Explicit_Dereference (Loc,
410 -- 2) Add the conversion to displace the pointer to reference
411 -- the secondary dispatch table.
413 Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
414 Analyze_And_Resolve (N, Dtyp);
416 -- 3) The 'access to the secondary dispatch table will be used
417 -- as the value returned by the allocator.
420 Make_Attribute_Reference (Loc,
421 Prefix => Relocate_Node (N),
422 Attribute_Name => Name_Access));
423 Set_Etype (N, Saved_Typ);
427 -- If the type of the allocator expression is an interface type we
428 -- generate a run-time call to displace "this" to reference the
429 -- component containing the pointer to the secondary dispatch table
430 -- or else raise Constraint_Error if the actual object does not
431 -- implement the target interface. This case corresponds with the
432 -- following example:
434 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
436 -- return new Iface_2'Class'(Obj);
441 Unchecked_Convert_To (PtrT,
442 Make_Function_Call (Loc,
443 Name => New_Reference_To (RTE (RE_Displace), Loc),
444 Parameter_Associations => New_List (
445 Unchecked_Convert_To (RTE (RE_Address),
451 (Access_Disp_Table (Etype (Base_Type (Dtyp))))),
453 Analyze_And_Resolve (N, PtrT);
456 end Displace_Allocator_Pointer;
458 ---------------------------------
459 -- Expand_Allocator_Expression --
460 ---------------------------------
462 procedure Expand_Allocator_Expression (N : Node_Id) is
463 Loc : constant Source_Ptr := Sloc (N);
464 Exp : constant Node_Id := Expression (Expression (N));
465 PtrT : constant Entity_Id := Etype (N);
466 DesigT : constant Entity_Id := Designated_Type (PtrT);
468 procedure Apply_Accessibility_Check
470 Built_In_Place : Boolean := False);
471 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
472 -- type, generate an accessibility check to verify that the level of the
473 -- type of the created object is not deeper than the level of the access
474 -- type. If the type of the qualified expression is class- wide, then
475 -- always generate the check (except in the case where it is known to be
476 -- unnecessary, see comment below). Otherwise, only generate the check
477 -- if the level of the qualified expression type is statically deeper
478 -- than the access type.
480 -- Although the static accessibility will generally have been performed
481 -- as a legality check, it won't have been done in cases where the
482 -- allocator appears in generic body, so a run-time check is needed in
483 -- general. One special case is when the access type is declared in the
484 -- same scope as the class-wide allocator, in which case the check can
485 -- never fail, so it need not be generated.
487 -- As an open issue, there seem to be cases where the static level
488 -- associated with the class-wide object's underlying type is not
489 -- sufficient to perform the proper accessibility check, such as for
490 -- allocators in nested subprograms or accept statements initialized by
491 -- class-wide formals when the actual originates outside at a deeper
492 -- static level. The nested subprogram case might require passing
493 -- accessibility levels along with class-wide parameters, and the task
494 -- case seems to be an actual gap in the language rules that needs to
495 -- be fixed by the ARG. ???
497 -------------------------------
498 -- Apply_Accessibility_Check --
499 -------------------------------
501 procedure Apply_Accessibility_Check
503 Built_In_Place : Boolean := False)
508 -- Note: we skip the accessibility check for the VM case, since
509 -- there does not seem to be any practical way of implementing it.
511 if Ada_Version >= Ada_05
512 and then VM_Target = No_VM
513 and then Is_Class_Wide_Type (DesigT)
514 and then not Scope_Suppress (Accessibility_Check)
516 (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
518 (Is_Class_Wide_Type (Etype (Exp))
519 and then Scope (PtrT) /= Current_Scope))
521 -- If the allocator was built in place Ref is already a reference
522 -- to the access object initialized to the result of the allocator
523 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise
524 -- it is the entity associated with the object containing the
525 -- address of the allocated object.
527 if Built_In_Place then
528 Ref_Node := New_Copy (Ref);
530 Ref_Node := New_Reference_To (Ref, Loc);
534 Make_Raise_Program_Error (Loc,
538 Build_Get_Access_Level (Loc,
539 Make_Attribute_Reference (Loc,
541 Attribute_Name => Name_Tag)),
543 Make_Integer_Literal (Loc,
544 Type_Access_Level (PtrT))),
545 Reason => PE_Accessibility_Check_Failed));
547 end Apply_Accessibility_Check;
551 Indic : constant Node_Id := Subtype_Mark (Expression (N));
552 T : constant Entity_Id := Entity (Indic);
557 TagT : Entity_Id := Empty;
558 -- Type used as source for tag assignment
560 TagR : Node_Id := Empty;
561 -- Target reference for tag assignment
563 Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
565 Tag_Assign : Node_Id;
568 -- Start of processing for Expand_Allocator_Expression
571 if Is_Tagged_Type (T) or else Needs_Finalization (T) then
573 -- Ada 2005 (AI-318-02): If the initialization expression is a call
574 -- to a build-in-place function, then access to the allocated object
575 -- must be passed to the function. Currently we limit such functions
576 -- to those with constrained limited result subtypes, but eventually
577 -- we plan to expand the allowed forms of functions that are treated
578 -- as build-in-place.
580 if Ada_Version >= Ada_05
581 and then Is_Build_In_Place_Function_Call (Exp)
583 Make_Build_In_Place_Call_In_Allocator (N, Exp);
584 Apply_Accessibility_Check (N, Built_In_Place => True);
588 -- Actions inserted before:
589 -- Temp : constant ptr_T := new T'(Expression);
590 -- <no CW> Temp._tag := T'tag;
591 -- <CTRL> Adjust (Finalizable (Temp.all));
592 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
594 -- We analyze by hand the new internal allocator to avoid
595 -- any recursion and inappropriate call to Initialize
597 -- We don't want to remove side effects when the expression must be
598 -- built in place. In the case of a build-in-place function call,
599 -- that could lead to a duplication of the call, which was already
600 -- substituted for the allocator.
602 if not Aggr_In_Place then
603 Remove_Side_Effects (Exp);
607 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
609 -- For a class wide allocation generate the following code:
611 -- type Equiv_Record is record ... end record;
612 -- implicit subtype CW is <Class_Wide_Subytpe>;
613 -- temp : PtrT := new CW'(CW!(expr));
615 if Is_Class_Wide_Type (T) then
616 Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
618 -- Ada 2005 (AI-251): If the expression is a class-wide interface
619 -- object we generate code to move up "this" to reference the
620 -- base of the object before allocating the new object.
622 -- Note that Exp'Address is recursively expanded into a call
623 -- to Base_Address (Exp.Tag)
625 if Is_Class_Wide_Type (Etype (Exp))
626 and then Is_Interface (Etype (Exp))
627 and then VM_Target = No_VM
631 Unchecked_Convert_To (Entity (Indic),
632 Make_Explicit_Dereference (Loc,
633 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
634 Make_Attribute_Reference (Loc,
636 Attribute_Name => Name_Address)))));
641 Unchecked_Convert_To (Entity (Indic), Exp));
644 Analyze_And_Resolve (Expression (N), Entity (Indic));
647 -- Keep separate the management of allocators returning interfaces
649 if not Is_Interface (Directly_Designated_Type (PtrT)) then
650 if Aggr_In_Place then
652 Make_Object_Declaration (Loc,
653 Defining_Identifier => Temp,
654 Object_Definition => New_Reference_To (PtrT, Loc),
657 New_Reference_To (Etype (Exp), Loc)));
659 Set_Comes_From_Source
660 (Expression (Tmp_Node), Comes_From_Source (N));
662 Set_No_Initialization (Expression (Tmp_Node));
663 Insert_Action (N, Tmp_Node);
665 if Needs_Finalization (T)
666 and then Ekind (PtrT) = E_Anonymous_Access_Type
668 -- Create local finalization list for access parameter
670 Flist := Get_Allocator_Final_List (N, Base_Type (T), PtrT);
673 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
675 Node := Relocate_Node (N);
678 Make_Object_Declaration (Loc,
679 Defining_Identifier => Temp,
680 Constant_Present => True,
681 Object_Definition => New_Reference_To (PtrT, Loc),
682 Expression => Node));
685 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
686 -- interface type. In this case we use the type of the qualified
687 -- expression to allocate the object.
691 Def_Id : constant Entity_Id :=
692 Make_Defining_Identifier (Loc,
693 New_Internal_Name ('T'));
698 Make_Full_Type_Declaration (Loc,
699 Defining_Identifier => Def_Id,
701 Make_Access_To_Object_Definition (Loc,
703 Null_Exclusion_Present => False,
704 Constant_Present => False,
705 Subtype_Indication =>
706 New_Reference_To (Etype (Exp), Loc)));
708 Insert_Action (N, New_Decl);
710 -- Inherit the final chain to ensure that the expansion of the
711 -- aggregate is correct in case of controlled types
713 if Needs_Finalization (Directly_Designated_Type (PtrT)) then
714 Set_Associated_Final_Chain (Def_Id,
715 Associated_Final_Chain (PtrT));
718 -- Declare the object using the previous type declaration
720 if Aggr_In_Place then
722 Make_Object_Declaration (Loc,
723 Defining_Identifier => Temp,
724 Object_Definition => New_Reference_To (Def_Id, Loc),
727 New_Reference_To (Etype (Exp), Loc)));
729 Set_Comes_From_Source
730 (Expression (Tmp_Node), Comes_From_Source (N));
732 Set_No_Initialization (Expression (Tmp_Node));
733 Insert_Action (N, Tmp_Node);
735 if Needs_Finalization (T)
736 and then Ekind (PtrT) = E_Anonymous_Access_Type
738 -- Create local finalization list for access parameter
741 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
744 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
746 Node := Relocate_Node (N);
749 Make_Object_Declaration (Loc,
750 Defining_Identifier => Temp,
751 Constant_Present => True,
752 Object_Definition => New_Reference_To (Def_Id, Loc),
753 Expression => Node));
756 -- Generate an additional object containing the address of the
757 -- returned object. The type of this second object declaration
758 -- is the correct type required for the common processing that
759 -- is still performed by this subprogram. The displacement of
760 -- this pointer to reference the component associated with the
761 -- interface type will be done at the end of common processing.
764 Make_Object_Declaration (Loc,
765 Defining_Identifier => Make_Defining_Identifier (Loc,
766 New_Internal_Name ('P')),
767 Object_Definition => New_Reference_To (PtrT, Loc),
768 Expression => Unchecked_Convert_To (PtrT,
769 New_Reference_To (Temp, Loc)));
771 Insert_Action (N, New_Decl);
773 Tmp_Node := New_Decl;
774 Temp := Defining_Identifier (New_Decl);
778 Apply_Accessibility_Check (Temp);
780 -- Generate the tag assignment
782 -- Suppress the tag assignment when VM_Target because VM tags are
783 -- represented implicitly in objects.
785 if VM_Target /= No_VM then
788 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
789 -- interface objects because in this case the tag does not change.
791 elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
792 pragma Assert (Is_Class_Wide_Type
793 (Directly_Designated_Type (Etype (N))));
796 elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
798 TagR := New_Reference_To (Temp, Loc);
800 elsif Is_Private_Type (T)
801 and then Is_Tagged_Type (Underlying_Type (T))
803 TagT := Underlying_Type (T);
805 Unchecked_Convert_To (Underlying_Type (T),
806 Make_Explicit_Dereference (Loc,
807 Prefix => New_Reference_To (Temp, Loc)));
810 if Present (TagT) then
812 Make_Assignment_Statement (Loc,
814 Make_Selected_Component (Loc,
817 New_Reference_To (First_Tag_Component (TagT), Loc)),
820 Unchecked_Convert_To (RTE (RE_Tag),
822 (Elists.Node (First_Elmt (Access_Disp_Table (TagT))),
825 -- The previous assignment has to be done in any case
827 Set_Assignment_OK (Name (Tag_Assign));
828 Insert_Action (N, Tag_Assign);
831 if Needs_Finalization (DesigT)
832 and then Needs_Finalization (T)
836 Apool : constant Entity_Id :=
837 Associated_Storage_Pool (PtrT);
840 -- If it is an allocation on the secondary stack (i.e. a value
841 -- returned from a function), the object is attached on the
842 -- caller side as soon as the call is completed (see
843 -- Expand_Ctrl_Function_Call)
845 if Is_RTE (Apool, RE_SS_Pool) then
847 F : constant Entity_Id :=
848 Make_Defining_Identifier (Loc,
849 New_Internal_Name ('F'));
852 Make_Object_Declaration (Loc,
853 Defining_Identifier => F,
854 Object_Definition => New_Reference_To (RTE
855 (RE_Finalizable_Ptr), Loc)));
857 Flist := New_Reference_To (F, Loc);
858 Attach := Make_Integer_Literal (Loc, 1);
861 -- Normal case, not a secondary stack allocation
864 if Needs_Finalization (T)
865 and then Ekind (PtrT) = E_Anonymous_Access_Type
867 -- Create local finalization list for access parameter
870 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
872 Flist := Find_Final_List (PtrT);
875 Attach := Make_Integer_Literal (Loc, 2);
878 -- Generate an Adjust call if the object will be moved. In Ada
879 -- 2005, the object may be inherently limited, in which case
880 -- there is no Adjust procedure, and the object is built in
881 -- place. In Ada 95, the object can be limited but not
882 -- inherently limited if this allocator came from a return
883 -- statement (we're allocating the result on the secondary
884 -- stack). In that case, the object will be moved, so we _do_
888 and then not Is_Inherently_Limited_Type (T)
894 -- An unchecked conversion is needed in the classwide
895 -- case because the designated type can be an ancestor of
896 -- the subtype mark of the allocator.
898 Unchecked_Convert_To (T,
899 Make_Explicit_Dereference (Loc,
900 Prefix => New_Reference_To (Temp, Loc))),
904 With_Attach => Attach,
910 Rewrite (N, New_Reference_To (Temp, Loc));
911 Analyze_And_Resolve (N, PtrT);
913 -- Ada 2005 (AI-251): Displace the pointer to reference the record
914 -- component containing the secondary dispatch table of the interface
917 if Is_Interface (Directly_Designated_Type (PtrT)) then
918 Displace_Allocator_Pointer (N);
921 elsif Aggr_In_Place then
923 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
925 Make_Object_Declaration (Loc,
926 Defining_Identifier => Temp,
927 Object_Definition => New_Reference_To (PtrT, Loc),
928 Expression => Make_Allocator (Loc,
929 New_Reference_To (Etype (Exp), Loc)));
931 Set_Comes_From_Source
932 (Expression (Tmp_Node), Comes_From_Source (N));
934 Set_No_Initialization (Expression (Tmp_Node));
935 Insert_Action (N, Tmp_Node);
936 Convert_Aggr_In_Allocator (N, Tmp_Node, Exp);
937 Rewrite (N, New_Reference_To (Temp, Loc));
938 Analyze_And_Resolve (N, PtrT);
940 elsif Is_Access_Type (T)
941 and then Can_Never_Be_Null (T)
943 Install_Null_Excluding_Check (Exp);
945 elsif Is_Access_Type (DesigT)
946 and then Nkind (Exp) = N_Allocator
947 and then Nkind (Expression (Exp)) /= N_Qualified_Expression
949 -- Apply constraint to designated subtype indication
951 Apply_Constraint_Check (Expression (Exp),
952 Designated_Type (DesigT),
955 if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
957 -- Propagate constraint_error to enclosing allocator
959 Rewrite (Exp, New_Copy (Expression (Exp)));
962 -- First check against the type of the qualified expression
964 -- NOTE: The commented call should be correct, but for some reason
965 -- causes the compiler to bomb (sigsegv) on ACVC test c34007g, so for
966 -- now we just perform the old (incorrect) test against the
967 -- designated subtype with no sliding in the else part of the if
968 -- statement below. ???
970 -- Apply_Constraint_Check (Exp, T, No_Sliding => True);
972 -- A check is also needed in cases where the designated subtype is
973 -- constrained and differs from the subtype given in the qualified
974 -- expression. Note that the check on the qualified expression does
975 -- not allow sliding, but this check does (a relaxation from Ada 83).
977 if Is_Constrained (DesigT)
978 and then not Subtypes_Statically_Match (T, DesigT)
980 Apply_Constraint_Check
981 (Exp, DesigT, No_Sliding => False);
983 -- The nonsliding check should really be performed (unconditionally)
984 -- against the subtype of the qualified expression, but that causes a
985 -- problem with c34007g (see above), so for now we retain this.
988 Apply_Constraint_Check
989 (Exp, DesigT, No_Sliding => True);
992 -- For an access to unconstrained packed array, GIGI needs to see an
993 -- expression with a constrained subtype in order to compute the
994 -- proper size for the allocator.
997 and then not Is_Constrained (T)
998 and then Is_Packed (T)
1001 ConstrT : constant Entity_Id :=
1002 Make_Defining_Identifier (Loc,
1003 Chars => New_Internal_Name ('A'));
1004 Internal_Exp : constant Node_Id := Relocate_Node (Exp);
1007 Make_Subtype_Declaration (Loc,
1008 Defining_Identifier => ConstrT,
1009 Subtype_Indication =>
1010 Make_Subtype_From_Expr (Exp, T)));
1011 Freeze_Itype (ConstrT, Exp);
1012 Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
1016 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1017 -- to a build-in-place function, then access to the allocated object
1018 -- must be passed to the function. Currently we limit such functions
1019 -- to those with constrained limited result subtypes, but eventually
1020 -- we plan to expand the allowed forms of functions that are treated
1021 -- as build-in-place.
1023 if Ada_Version >= Ada_05
1024 and then Is_Build_In_Place_Function_Call (Exp)
1026 Make_Build_In_Place_Call_In_Allocator (N, Exp);
1031 when RE_Not_Available =>
1033 end Expand_Allocator_Expression;
1035 -----------------------------
1036 -- Expand_Array_Comparison --
1037 -----------------------------
1039 -- Expansion is only required in the case of array types. For the unpacked
1040 -- case, an appropriate runtime routine is called. For packed cases, and
1041 -- also in some other cases where a runtime routine cannot be called, the
1042 -- form of the expansion is:
1044 -- [body for greater_nn; boolean_expression]
1046 -- The body is built by Make_Array_Comparison_Op, and the form of the
1047 -- Boolean expression depends on the operator involved.
1049 procedure Expand_Array_Comparison (N : Node_Id) is
1050 Loc : constant Source_Ptr := Sloc (N);
1051 Op1 : Node_Id := Left_Opnd (N);
1052 Op2 : Node_Id := Right_Opnd (N);
1053 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
1054 Ctyp : constant Entity_Id := Component_Type (Typ1);
1057 Func_Body : Node_Id;
1058 Func_Name : Entity_Id;
1062 Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
1063 -- True for byte addressable target
1065 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
1066 -- Returns True if the length of the given operand is known to be less
1067 -- than 4. Returns False if this length is known to be four or greater
1068 -- or is not known at compile time.
1070 ------------------------
1071 -- Length_Less_Than_4 --
1072 ------------------------
1074 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
1075 Otyp : constant Entity_Id := Etype (Opnd);
1078 if Ekind (Otyp) = E_String_Literal_Subtype then
1079 return String_Literal_Length (Otyp) < 4;
1083 Ityp : constant Entity_Id := Etype (First_Index (Otyp));
1084 Lo : constant Node_Id := Type_Low_Bound (Ityp);
1085 Hi : constant Node_Id := Type_High_Bound (Ityp);
1090 if Compile_Time_Known_Value (Lo) then
1091 Lov := Expr_Value (Lo);
1096 if Compile_Time_Known_Value (Hi) then
1097 Hiv := Expr_Value (Hi);
1102 return Hiv < Lov + 3;
1105 end Length_Less_Than_4;
1107 -- Start of processing for Expand_Array_Comparison
1110 -- Deal first with unpacked case, where we can call a runtime routine
1111 -- except that we avoid this for targets for which are not addressable
1112 -- by bytes, and for the JVM/CIL, since they do not support direct
1113 -- addressing of array components.
1115 if not Is_Bit_Packed_Array (Typ1)
1116 and then Byte_Addressable
1117 and then VM_Target = No_VM
1119 -- The call we generate is:
1121 -- Compare_Array_xn[_Unaligned]
1122 -- (left'address, right'address, left'length, right'length) <op> 0
1124 -- x = U for unsigned, S for signed
1125 -- n = 8,16,32,64 for component size
1126 -- Add _Unaligned if length < 4 and component size is 8.
1127 -- <op> is the standard comparison operator
1129 if Component_Size (Typ1) = 8 then
1130 if Length_Less_Than_4 (Op1)
1132 Length_Less_Than_4 (Op2)
1134 if Is_Unsigned_Type (Ctyp) then
1135 Comp := RE_Compare_Array_U8_Unaligned;
1137 Comp := RE_Compare_Array_S8_Unaligned;
1141 if Is_Unsigned_Type (Ctyp) then
1142 Comp := RE_Compare_Array_U8;
1144 Comp := RE_Compare_Array_S8;
1148 elsif Component_Size (Typ1) = 16 then
1149 if Is_Unsigned_Type (Ctyp) then
1150 Comp := RE_Compare_Array_U16;
1152 Comp := RE_Compare_Array_S16;
1155 elsif Component_Size (Typ1) = 32 then
1156 if Is_Unsigned_Type (Ctyp) then
1157 Comp := RE_Compare_Array_U32;
1159 Comp := RE_Compare_Array_S32;
1162 else pragma Assert (Component_Size (Typ1) = 64);
1163 if Is_Unsigned_Type (Ctyp) then
1164 Comp := RE_Compare_Array_U64;
1166 Comp := RE_Compare_Array_S64;
1170 Remove_Side_Effects (Op1, Name_Req => True);
1171 Remove_Side_Effects (Op2, Name_Req => True);
1174 Make_Function_Call (Sloc (Op1),
1175 Name => New_Occurrence_Of (RTE (Comp), Loc),
1177 Parameter_Associations => New_List (
1178 Make_Attribute_Reference (Loc,
1179 Prefix => Relocate_Node (Op1),
1180 Attribute_Name => Name_Address),
1182 Make_Attribute_Reference (Loc,
1183 Prefix => Relocate_Node (Op2),
1184 Attribute_Name => Name_Address),
1186 Make_Attribute_Reference (Loc,
1187 Prefix => Relocate_Node (Op1),
1188 Attribute_Name => Name_Length),
1190 Make_Attribute_Reference (Loc,
1191 Prefix => Relocate_Node (Op2),
1192 Attribute_Name => Name_Length))));
1195 Make_Integer_Literal (Sloc (Op2),
1198 Analyze_And_Resolve (Op1, Standard_Integer);
1199 Analyze_And_Resolve (Op2, Standard_Integer);
1203 -- Cases where we cannot make runtime call
1205 -- For (a <= b) we convert to not (a > b)
1207 if Chars (N) = Name_Op_Le then
1213 Right_Opnd => Op2)));
1214 Analyze_And_Resolve (N, Standard_Boolean);
1217 -- For < the Boolean expression is
1218 -- greater__nn (op2, op1)
1220 elsif Chars (N) = Name_Op_Lt then
1221 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1225 Op1 := Right_Opnd (N);
1226 Op2 := Left_Opnd (N);
1228 -- For (a >= b) we convert to not (a < b)
1230 elsif Chars (N) = Name_Op_Ge then
1236 Right_Opnd => Op2)));
1237 Analyze_And_Resolve (N, Standard_Boolean);
1240 -- For > the Boolean expression is
1241 -- greater__nn (op1, op2)
1244 pragma Assert (Chars (N) = Name_Op_Gt);
1245 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1248 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1250 Make_Function_Call (Loc,
1251 Name => New_Reference_To (Func_Name, Loc),
1252 Parameter_Associations => New_List (Op1, Op2));
1254 Insert_Action (N, Func_Body);
1256 Analyze_And_Resolve (N, Standard_Boolean);
1259 when RE_Not_Available =>
1261 end Expand_Array_Comparison;
1263 ---------------------------
1264 -- Expand_Array_Equality --
1265 ---------------------------
1267 -- Expand an equality function for multi-dimensional arrays. Here is an
1268 -- example of such a function for Nb_Dimension = 2
1270 -- function Enn (A : atyp; B : btyp) return boolean is
1272 -- if (A'length (1) = 0 or else A'length (2) = 0)
1274 -- (B'length (1) = 0 or else B'length (2) = 0)
1276 -- return True; -- RM 4.5.2(22)
1279 -- if A'length (1) /= B'length (1)
1281 -- A'length (2) /= B'length (2)
1283 -- return False; -- RM 4.5.2(23)
1287 -- A1 : Index_T1 := A'first (1);
1288 -- B1 : Index_T1 := B'first (1);
1292 -- A2 : Index_T2 := A'first (2);
1293 -- B2 : Index_T2 := B'first (2);
1296 -- if A (A1, A2) /= B (B1, B2) then
1300 -- exit when A2 = A'last (2);
1301 -- A2 := Index_T2'succ (A2);
1302 -- B2 := Index_T2'succ (B2);
1306 -- exit when A1 = A'last (1);
1307 -- A1 := Index_T1'succ (A1);
1308 -- B1 := Index_T1'succ (B1);
1315 -- Note on the formal types used (atyp and btyp). If either of the arrays
1316 -- is of a private type, we use the underlying type, and do an unchecked
1317 -- conversion of the actual. If either of the arrays has a bound depending
1318 -- on a discriminant, then we use the base type since otherwise we have an
1319 -- escaped discriminant in the function.
1321 -- If both arrays are constrained and have the same bounds, we can generate
1322 -- a loop with an explicit iteration scheme using a 'Range attribute over
1325 function Expand_Array_Equality
1330 Typ : Entity_Id) return Node_Id
1332 Loc : constant Source_Ptr := Sloc (Nod);
1333 Decls : constant List_Id := New_List;
1334 Index_List1 : constant List_Id := New_List;
1335 Index_List2 : constant List_Id := New_List;
1339 Func_Name : Entity_Id;
1340 Func_Body : Node_Id;
1342 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
1343 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
1347 -- The parameter types to be used for the formals
1352 Num : Int) return Node_Id;
1353 -- This builds the attribute reference Arr'Nam (Expr)
1355 function Component_Equality (Typ : Entity_Id) return Node_Id;
1356 -- Create one statement to compare corresponding components, designated
1357 -- by a full set of indices.
1359 function Get_Arg_Type (N : Node_Id) return Entity_Id;
1360 -- Given one of the arguments, computes the appropriate type to be used
1361 -- for that argument in the corresponding function formal
1363 function Handle_One_Dimension
1365 Index : Node_Id) return Node_Id;
1366 -- This procedure returns the following code
1369 -- Bn : Index_T := B'First (N);
1373 -- exit when An = A'Last (N);
1374 -- An := Index_T'Succ (An)
1375 -- Bn := Index_T'Succ (Bn)
1379 -- If both indices are constrained and identical, the procedure
1380 -- returns a simpler loop:
1382 -- for An in A'Range (N) loop
1386 -- N is the dimension for which we are generating a loop. Index is the
1387 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1388 -- xxx statement is either the loop or declare for the next dimension
1389 -- or if this is the last dimension the comparison of corresponding
1390 -- components of the arrays.
1392 -- The actual way the code works is to return the comparison of
1393 -- corresponding components for the N+1 call. That's neater!
1395 function Test_Empty_Arrays return Node_Id;
1396 -- This function constructs the test for both arrays being empty
1397 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1399 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1401 function Test_Lengths_Correspond return Node_Id;
1402 -- This function constructs the test for arrays having different lengths
1403 -- in at least one index position, in which case the resulting code is:
1405 -- A'length (1) /= B'length (1)
1407 -- A'length (2) /= B'length (2)
1418 Num : Int) return Node_Id
1422 Make_Attribute_Reference (Loc,
1423 Attribute_Name => Nam,
1424 Prefix => New_Reference_To (Arr, Loc),
1425 Expressions => New_List (Make_Integer_Literal (Loc, Num)));
1428 ------------------------
1429 -- Component_Equality --
1430 ------------------------
1432 function Component_Equality (Typ : Entity_Id) return Node_Id is
1437 -- if a(i1...) /= b(j1...) then return false; end if;
1440 Make_Indexed_Component (Loc,
1441 Prefix => Make_Identifier (Loc, Chars (A)),
1442 Expressions => Index_List1);
1445 Make_Indexed_Component (Loc,
1446 Prefix => Make_Identifier (Loc, Chars (B)),
1447 Expressions => Index_List2);
1449 Test := Expand_Composite_Equality
1450 (Nod, Component_Type (Typ), L, R, Decls);
1452 -- If some (sub)component is an unchecked_union, the whole operation
1453 -- will raise program error.
1455 if Nkind (Test) = N_Raise_Program_Error then
1457 -- This node is going to be inserted at a location where a
1458 -- statement is expected: clear its Etype so analysis will set
1459 -- it to the expected Standard_Void_Type.
1461 Set_Etype (Test, Empty);
1466 Make_Implicit_If_Statement (Nod,
1467 Condition => Make_Op_Not (Loc, Right_Opnd => Test),
1468 Then_Statements => New_List (
1469 Make_Simple_Return_Statement (Loc,
1470 Expression => New_Occurrence_Of (Standard_False, Loc))));
1472 end Component_Equality;
1478 function Get_Arg_Type (N : Node_Id) return Entity_Id is
1489 T := Underlying_Type (T);
1491 X := First_Index (T);
1492 while Present (X) loop
1493 if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
1495 Denotes_Discriminant (Type_High_Bound (Etype (X)))
1508 --------------------------
1509 -- Handle_One_Dimension --
1510 ---------------------------
1512 function Handle_One_Dimension
1514 Index : Node_Id) return Node_Id
1516 Need_Separate_Indexes : constant Boolean :=
1518 or else not Is_Constrained (Ltyp);
1519 -- If the index types are identical, and we are working with
1520 -- constrained types, then we can use the same index for both
1523 An : constant Entity_Id := Make_Defining_Identifier (Loc,
1524 Chars => New_Internal_Name ('A'));
1527 Index_T : Entity_Id;
1532 if N > Number_Dimensions (Ltyp) then
1533 return Component_Equality (Ltyp);
1536 -- Case where we generate a loop
1538 Index_T := Base_Type (Etype (Index));
1540 if Need_Separate_Indexes then
1542 Make_Defining_Identifier (Loc,
1543 Chars => New_Internal_Name ('B'));
1548 Append (New_Reference_To (An, Loc), Index_List1);
1549 Append (New_Reference_To (Bn, Loc), Index_List2);
1551 Stm_List := New_List (
1552 Handle_One_Dimension (N + 1, Next_Index (Index)));
1554 if Need_Separate_Indexes then
1556 -- Generate guard for loop, followed by increments of indices
1558 Append_To (Stm_List,
1559 Make_Exit_Statement (Loc,
1562 Left_Opnd => New_Reference_To (An, Loc),
1563 Right_Opnd => Arr_Attr (A, Name_Last, N))));
1565 Append_To (Stm_List,
1566 Make_Assignment_Statement (Loc,
1567 Name => New_Reference_To (An, Loc),
1569 Make_Attribute_Reference (Loc,
1570 Prefix => New_Reference_To (Index_T, Loc),
1571 Attribute_Name => Name_Succ,
1572 Expressions => New_List (New_Reference_To (An, Loc)))));
1574 Append_To (Stm_List,
1575 Make_Assignment_Statement (Loc,
1576 Name => New_Reference_To (Bn, Loc),
1578 Make_Attribute_Reference (Loc,
1579 Prefix => New_Reference_To (Index_T, Loc),
1580 Attribute_Name => Name_Succ,
1581 Expressions => New_List (New_Reference_To (Bn, Loc)))));
1584 -- If separate indexes, we need a declare block for An and Bn, and a
1585 -- loop without an iteration scheme.
1587 if Need_Separate_Indexes then
1589 Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
1592 Make_Block_Statement (Loc,
1593 Declarations => New_List (
1594 Make_Object_Declaration (Loc,
1595 Defining_Identifier => An,
1596 Object_Definition => New_Reference_To (Index_T, Loc),
1597 Expression => Arr_Attr (A, Name_First, N)),
1599 Make_Object_Declaration (Loc,
1600 Defining_Identifier => Bn,
1601 Object_Definition => New_Reference_To (Index_T, Loc),
1602 Expression => Arr_Attr (B, Name_First, N))),
1604 Handled_Statement_Sequence =>
1605 Make_Handled_Sequence_Of_Statements (Loc,
1606 Statements => New_List (Loop_Stm)));
1608 -- If no separate indexes, return loop statement with explicit
1609 -- iteration scheme on its own
1613 Make_Implicit_Loop_Statement (Nod,
1614 Statements => Stm_List,
1616 Make_Iteration_Scheme (Loc,
1617 Loop_Parameter_Specification =>
1618 Make_Loop_Parameter_Specification (Loc,
1619 Defining_Identifier => An,
1620 Discrete_Subtype_Definition =>
1621 Arr_Attr (A, Name_Range, N))));
1624 end Handle_One_Dimension;
1626 -----------------------
1627 -- Test_Empty_Arrays --
1628 -----------------------
1630 function Test_Empty_Arrays return Node_Id is
1640 for J in 1 .. Number_Dimensions (Ltyp) loop
1643 Left_Opnd => Arr_Attr (A, Name_Length, J),
1644 Right_Opnd => Make_Integer_Literal (Loc, 0));
1648 Left_Opnd => Arr_Attr (B, Name_Length, J),
1649 Right_Opnd => Make_Integer_Literal (Loc, 0));
1658 Left_Opnd => Relocate_Node (Alist),
1659 Right_Opnd => Atest);
1663 Left_Opnd => Relocate_Node (Blist),
1664 Right_Opnd => Btest);
1671 Right_Opnd => Blist);
1672 end Test_Empty_Arrays;
1674 -----------------------------
1675 -- Test_Lengths_Correspond --
1676 -----------------------------
1678 function Test_Lengths_Correspond return Node_Id is
1684 for J in 1 .. Number_Dimensions (Ltyp) loop
1687 Left_Opnd => Arr_Attr (A, Name_Length, J),
1688 Right_Opnd => Arr_Attr (B, Name_Length, J));
1695 Left_Opnd => Relocate_Node (Result),
1696 Right_Opnd => Rtest);
1701 end Test_Lengths_Correspond;
1703 -- Start of processing for Expand_Array_Equality
1706 Ltyp := Get_Arg_Type (Lhs);
1707 Rtyp := Get_Arg_Type (Rhs);
1709 -- For now, if the argument types are not the same, go to the base type,
1710 -- since the code assumes that the formals have the same type. This is
1711 -- fixable in future ???
1713 if Ltyp /= Rtyp then
1714 Ltyp := Base_Type (Ltyp);
1715 Rtyp := Base_Type (Rtyp);
1716 pragma Assert (Ltyp = Rtyp);
1719 -- Build list of formals for function
1721 Formals := New_List (
1722 Make_Parameter_Specification (Loc,
1723 Defining_Identifier => A,
1724 Parameter_Type => New_Reference_To (Ltyp, Loc)),
1726 Make_Parameter_Specification (Loc,
1727 Defining_Identifier => B,
1728 Parameter_Type => New_Reference_To (Rtyp, Loc)));
1730 Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
1732 -- Build statement sequence for function
1735 Make_Subprogram_Body (Loc,
1737 Make_Function_Specification (Loc,
1738 Defining_Unit_Name => Func_Name,
1739 Parameter_Specifications => Formals,
1740 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
1742 Declarations => Decls,
1744 Handled_Statement_Sequence =>
1745 Make_Handled_Sequence_Of_Statements (Loc,
1746 Statements => New_List (
1748 Make_Implicit_If_Statement (Nod,
1749 Condition => Test_Empty_Arrays,
1750 Then_Statements => New_List (
1751 Make_Simple_Return_Statement (Loc,
1753 New_Occurrence_Of (Standard_True, Loc)))),
1755 Make_Implicit_If_Statement (Nod,
1756 Condition => Test_Lengths_Correspond,
1757 Then_Statements => New_List (
1758 Make_Simple_Return_Statement (Loc,
1760 New_Occurrence_Of (Standard_False, Loc)))),
1762 Handle_One_Dimension (1, First_Index (Ltyp)),
1764 Make_Simple_Return_Statement (Loc,
1765 Expression => New_Occurrence_Of (Standard_True, Loc)))));
1767 Set_Has_Completion (Func_Name, True);
1768 Set_Is_Inlined (Func_Name);
1770 -- If the array type is distinct from the type of the arguments, it
1771 -- is the full view of a private type. Apply an unchecked conversion
1772 -- to insure that analysis of the call succeeds.
1782 or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
1784 L := OK_Convert_To (Ltyp, Lhs);
1788 or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
1790 R := OK_Convert_To (Rtyp, Rhs);
1793 Actuals := New_List (L, R);
1796 Append_To (Bodies, Func_Body);
1799 Make_Function_Call (Loc,
1800 Name => New_Reference_To (Func_Name, Loc),
1801 Parameter_Associations => Actuals);
1802 end Expand_Array_Equality;
1804 -----------------------------
1805 -- Expand_Boolean_Operator --
1806 -----------------------------
1808 -- Note that we first get the actual subtypes of the operands, since we
1809 -- always want to deal with types that have bounds.
1811 procedure Expand_Boolean_Operator (N : Node_Id) is
1812 Typ : constant Entity_Id := Etype (N);
1815 -- Special case of bit packed array where both operands are known to be
1816 -- properly aligned. In this case we use an efficient run time routine
1817 -- to carry out the operation (see System.Bit_Ops).
1819 if Is_Bit_Packed_Array (Typ)
1820 and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
1821 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
1823 Expand_Packed_Boolean_Operator (N);
1827 -- For the normal non-packed case, the general expansion is to build
1828 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
1829 -- and then inserting it into the tree. The original operator node is
1830 -- then rewritten as a call to this function. We also use this in the
1831 -- packed case if either operand is a possibly unaligned object.
1834 Loc : constant Source_Ptr := Sloc (N);
1835 L : constant Node_Id := Relocate_Node (Left_Opnd (N));
1836 R : constant Node_Id := Relocate_Node (Right_Opnd (N));
1837 Func_Body : Node_Id;
1838 Func_Name : Entity_Id;
1841 Convert_To_Actual_Subtype (L);
1842 Convert_To_Actual_Subtype (R);
1843 Ensure_Defined (Etype (L), N);
1844 Ensure_Defined (Etype (R), N);
1845 Apply_Length_Check (R, Etype (L));
1847 if Nkind (N) = N_Op_Xor then
1848 Silly_Boolean_Array_Xor_Test (N, Etype (L));
1851 if Nkind (Parent (N)) = N_Assignment_Statement
1852 and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
1854 Build_Boolean_Array_Proc_Call (Parent (N), L, R);
1856 elsif Nkind (Parent (N)) = N_Op_Not
1857 and then Nkind (N) = N_Op_And
1859 Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
1864 Func_Body := Make_Boolean_Array_Op (Etype (L), N);
1865 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1866 Insert_Action (N, Func_Body);
1868 -- Now rewrite the expression with a call
1871 Make_Function_Call (Loc,
1872 Name => New_Reference_To (Func_Name, Loc),
1873 Parameter_Associations =>
1876 Make_Type_Conversion
1877 (Loc, New_Reference_To (Etype (L), Loc), R))));
1879 Analyze_And_Resolve (N, Typ);
1882 end Expand_Boolean_Operator;
1884 -------------------------------
1885 -- Expand_Composite_Equality --
1886 -------------------------------
1888 -- This function is only called for comparing internal fields of composite
1889 -- types when these fields are themselves composites. This is a special
1890 -- case because it is not possible to respect normal Ada visibility rules.
1892 function Expand_Composite_Equality
1897 Bodies : List_Id) return Node_Id
1899 Loc : constant Source_Ptr := Sloc (Nod);
1900 Full_Type : Entity_Id;
1905 if Is_Private_Type (Typ) then
1906 Full_Type := Underlying_Type (Typ);
1911 -- Defense against malformed private types with no completion the error
1912 -- will be diagnosed later by check_completion
1914 if No (Full_Type) then
1915 return New_Reference_To (Standard_False, Loc);
1918 Full_Type := Base_Type (Full_Type);
1920 if Is_Array_Type (Full_Type) then
1922 -- If the operand is an elementary type other than a floating-point
1923 -- type, then we can simply use the built-in block bitwise equality,
1924 -- since the predefined equality operators always apply and bitwise
1925 -- equality is fine for all these cases.
1927 if Is_Elementary_Type (Component_Type (Full_Type))
1928 and then not Is_Floating_Point_Type (Component_Type (Full_Type))
1930 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
1932 -- For composite component types, and floating-point types, use the
1933 -- expansion. This deals with tagged component types (where we use
1934 -- the applicable equality routine) and floating-point, (where we
1935 -- need to worry about negative zeroes), and also the case of any
1936 -- composite type recursively containing such fields.
1939 return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
1942 elsif Is_Tagged_Type (Full_Type) then
1944 -- Call the primitive operation "=" of this type
1946 if Is_Class_Wide_Type (Full_Type) then
1947 Full_Type := Root_Type (Full_Type);
1950 -- If this is derived from an untagged private type completed with a
1951 -- tagged type, it does not have a full view, so we use the primitive
1952 -- operations of the private type. This check should no longer be
1953 -- necessary when these types receive their full views ???
1955 if Is_Private_Type (Typ)
1956 and then not Is_Tagged_Type (Typ)
1957 and then not Is_Controlled (Typ)
1958 and then Is_Derived_Type (Typ)
1959 and then No (Full_View (Typ))
1961 Prim := First_Elmt (Collect_Primitive_Operations (Typ));
1963 Prim := First_Elmt (Primitive_Operations (Full_Type));
1967 Eq_Op := Node (Prim);
1968 exit when Chars (Eq_Op) = Name_Op_Eq
1969 and then Etype (First_Formal (Eq_Op)) =
1970 Etype (Next_Formal (First_Formal (Eq_Op)))
1971 and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
1973 pragma Assert (Present (Prim));
1976 Eq_Op := Node (Prim);
1979 Make_Function_Call (Loc,
1980 Name => New_Reference_To (Eq_Op, Loc),
1981 Parameter_Associations =>
1983 (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
1984 Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
1986 elsif Is_Record_Type (Full_Type) then
1987 Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
1989 if Present (Eq_Op) then
1990 if Etype (First_Formal (Eq_Op)) /= Full_Type then
1992 -- Inherited equality from parent type. Convert the actuals to
1993 -- match signature of operation.
1996 T : constant Entity_Id := Etype (First_Formal (Eq_Op));
2000 Make_Function_Call (Loc,
2001 Name => New_Reference_To (Eq_Op, Loc),
2002 Parameter_Associations =>
2003 New_List (OK_Convert_To (T, Lhs),
2004 OK_Convert_To (T, Rhs)));
2008 -- Comparison between Unchecked_Union components
2010 if Is_Unchecked_Union (Full_Type) then
2012 Lhs_Type : Node_Id := Full_Type;
2013 Rhs_Type : Node_Id := Full_Type;
2014 Lhs_Discr_Val : Node_Id;
2015 Rhs_Discr_Val : Node_Id;
2020 if Nkind (Lhs) = N_Selected_Component then
2021 Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
2026 if Nkind (Rhs) = N_Selected_Component then
2027 Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
2030 -- Lhs of the composite equality
2032 if Is_Constrained (Lhs_Type) then
2034 -- Since the enclosing record type can never be an
2035 -- Unchecked_Union (this code is executed for records
2036 -- that do not have variants), we may reference its
2039 if Nkind (Lhs) = N_Selected_Component
2040 and then Has_Per_Object_Constraint (
2041 Entity (Selector_Name (Lhs)))
2044 Make_Selected_Component (Loc,
2045 Prefix => Prefix (Lhs),
2048 Get_Discriminant_Value (
2049 First_Discriminant (Lhs_Type),
2051 Stored_Constraint (Lhs_Type))));
2054 Lhs_Discr_Val := New_Copy (
2055 Get_Discriminant_Value (
2056 First_Discriminant (Lhs_Type),
2058 Stored_Constraint (Lhs_Type)));
2062 -- It is not possible to infer the discriminant since
2063 -- the subtype is not constrained.
2066 Make_Raise_Program_Error (Loc,
2067 Reason => PE_Unchecked_Union_Restriction);
2070 -- Rhs of the composite equality
2072 if Is_Constrained (Rhs_Type) then
2073 if Nkind (Rhs) = N_Selected_Component
2074 and then Has_Per_Object_Constraint (
2075 Entity (Selector_Name (Rhs)))
2078 Make_Selected_Component (Loc,
2079 Prefix => Prefix (Rhs),
2082 Get_Discriminant_Value (
2083 First_Discriminant (Rhs_Type),
2085 Stored_Constraint (Rhs_Type))));
2088 Rhs_Discr_Val := New_Copy (
2089 Get_Discriminant_Value (
2090 First_Discriminant (Rhs_Type),
2092 Stored_Constraint (Rhs_Type)));
2097 Make_Raise_Program_Error (Loc,
2098 Reason => PE_Unchecked_Union_Restriction);
2101 -- Call the TSS equality function with the inferred
2102 -- discriminant values.
2105 Make_Function_Call (Loc,
2106 Name => New_Reference_To (Eq_Op, Loc),
2107 Parameter_Associations => New_List (
2115 -- Shouldn't this be an else, we can't fall through the above
2119 Make_Function_Call (Loc,
2120 Name => New_Reference_To (Eq_Op, Loc),
2121 Parameter_Associations => New_List (Lhs, Rhs));
2125 return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
2129 -- It can be a simple record or the full view of a scalar private
2131 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2133 end Expand_Composite_Equality;
2135 ------------------------
2136 -- Expand_Concatenate --
2137 ------------------------
2139 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
2140 Loc : constant Source_Ptr := Sloc (Cnode);
2142 Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
2143 -- Result type of concatenation
2145 Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
2146 -- Component type. Elements of this component type can appear as one
2147 -- of the operands of concatenation as well as arrays.
2149 Istyp : constant Entity_Id := Etype (First_Index (Atyp));
2152 Ityp : constant Entity_Id := Base_Type (Istyp);
2153 -- Index type. This is the base type of the index subtype, and is used
2154 -- for all computed bounds (which may be out of range of Istyp in the
2155 -- case of null ranges).
2158 -- This is the type we use to do arithmetic to compute the bounds and
2159 -- lengths of operands. The choice of this type is a little subtle and
2160 -- is discussed in a separate section at the start of the body code.
2162 Concatenation_Error : exception;
2163 -- Raised if concatenation is sure to raise a CE
2165 Result_May_Be_Null : Boolean := True;
2166 -- Reset to False if at least one operand is encountered which is known
2167 -- at compile time to be non-null. Used for handling the special case
2168 -- of setting the high bound to the last operand high bound for a null
2169 -- result, thus ensuring a proper high bound in the super-flat case.
2171 N : constant Nat := List_Length (Opnds);
2172 -- Number of concatenation operands including possibly null operands
2175 -- Number of operands excluding any known to be null, except that the
2176 -- last operand is always retained, in case it provides the bounds for
2180 -- Current operand being processed in the loop through operands. After
2181 -- this loop is complete, always contains the last operand (which is not
2182 -- the same as Operands (NN), since null operands are skipped).
2184 -- Arrays describing the operands, only the first NN entries of each
2185 -- array are set (NN < N when we exclude known null operands).
2187 Is_Fixed_Length : array (1 .. N) of Boolean;
2188 -- True if length of corresponding operand known at compile time
2190 Operands : array (1 .. N) of Node_Id;
2191 -- Set to the corresponding entry in the Opnds list (but note that null
2192 -- operands are excluded, so not all entries in the list are stored).
2194 Fixed_Length : array (1 .. N) of Uint;
2195 -- Set to length of operand. Entries in this array are set only if the
2196 -- corresponding entry in Is_Fixed_Length is True.
2198 Opnd_Low_Bound : array (1 .. N) of Node_Id;
2199 -- Set to lower bound of operand. Either an integer literal in the case
2200 -- where the bound is known at compile time, else actual lower bound.
2201 -- The operand low bound is of type Ityp.
2203 Var_Length : array (1 .. N) of Entity_Id;
2204 -- Set to an entity of type Natural that contains the length of an
2205 -- operand whose length is not known at compile time. Entries in this
2206 -- array are set only if the corresponding entry in Is_Fixed_Length
2207 -- is False. The entity is of type Artyp.
2209 Aggr_Length : array (0 .. N) of Node_Id;
2210 -- The J'th entry in an expression node that represents the total length
2211 -- of operands 1 through J. It is either an integer literal node, or a
2212 -- reference to a constant entity with the right value, so it is fine
2213 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2214 -- entry always is set to zero. The length is of type Artyp.
2216 Low_Bound : Node_Id;
2217 -- A tree node representing the low bound of the result (of type Ityp).
2218 -- This is either an integer literal node, or an identifier reference to
2219 -- a constant entity initialized to the appropriate value.
2221 Last_Opnd_High_Bound : Node_Id;
2222 -- A tree node representing the high bound of the last operand. This
2223 -- need only be set if the result could be null. It is used for the
2224 -- special case of setting the right high bound for a null result.
2225 -- This is of type Ityp.
2227 High_Bound : Node_Id;
2228 -- A tree node representing the high bound of the result (of type Ityp)
2231 -- Result of the concatenation (of type Ityp)
2233 Known_Non_Null_Operand_Seen : Boolean;
2234 -- Set True during generation of the assignements of operands into
2235 -- result once an operand known to be non-null has been seen.
2237 function Make_Artyp_Literal (Val : Nat) return Node_Id;
2238 -- This function makes an N_Integer_Literal node that is returned in
2239 -- analyzed form with the type set to Artyp. Importantly this literal
2240 -- is not flagged as static, so that if we do computations with it that
2241 -- result in statically detected out of range conditions, we will not
2242 -- generate error messages but instead warning messages.
2244 function To_Artyp (X : Node_Id) return Node_Id;
2245 -- Given a node of type Ityp, returns the corresponding value of type
2246 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2247 -- For enum types, the Pos of the value is returned.
2249 function To_Ityp (X : Node_Id) return Node_Id;
2250 -- The inverse function (uses Val in the case of enumeration types)
2252 ------------------------
2253 -- Make_Artyp_Literal --
2254 ------------------------
2256 function Make_Artyp_Literal (Val : Nat) return Node_Id is
2257 Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
2259 Set_Etype (Result, Artyp);
2260 Set_Analyzed (Result, True);
2261 Set_Is_Static_Expression (Result, False);
2263 end Make_Artyp_Literal;
2269 function To_Artyp (X : Node_Id) return Node_Id is
2271 if Ityp = Base_Type (Artyp) then
2274 elsif Is_Enumeration_Type (Ityp) then
2276 Make_Attribute_Reference (Loc,
2277 Prefix => New_Occurrence_Of (Ityp, Loc),
2278 Attribute_Name => Name_Pos,
2279 Expressions => New_List (X));
2282 return Convert_To (Artyp, X);
2290 function To_Ityp (X : Node_Id) return Node_Id is
2292 if Is_Enumeration_Type (Ityp) then
2294 Make_Attribute_Reference (Loc,
2295 Prefix => New_Occurrence_Of (Ityp, Loc),
2296 Attribute_Name => Name_Val,
2297 Expressions => New_List (X));
2299 -- Case where we will do a type conversion
2302 if Ityp = Base_Type (Artyp) then
2305 return Convert_To (Ityp, X);
2310 -- Local Declarations
2312 Opnd_Typ : Entity_Id;
2320 -- Choose an appropriate computational type
2322 -- We will be doing calculations of lengths and bounds in this routine
2323 -- and computing one from the other in some cases, e.g. getting the high
2324 -- bound by adding the length-1 to the low bound.
2326 -- We can't just use the index type, or even its base type for this
2327 -- purpose for two reasons. First it might be an enumeration type which
2328 -- is not suitable fo computations of any kind, and second it may simply
2329 -- not have enough range. For example if the index type is -128..+127
2330 -- then lengths can be up to 256, which is out of range of the type.
2332 -- For enumeration types, we can simply use Standard_Integer, this is
2333 -- sufficient since the actual number of enumeration literals cannot
2334 -- possibly exceed the range of integer (remember we will be doing the
2335 -- arithmetic with POS values, not representation values).
2337 if Is_Enumeration_Type (Ityp) then
2338 Artyp := Standard_Integer;
2340 -- For modular types, we use a 32-bit modular type for types whose size
2341 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2342 -- identity type, and for larger unsigned types we use 64-bits.
2344 elsif Is_Modular_Integer_Type (Ityp) then
2345 if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
2346 Artyp := Standard_Unsigned;
2347 elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
2350 Artyp := RTE (RE_Long_Long_Unsigned);
2353 -- Similar treatment for signed types
2356 if RM_Size (Ityp) < RM_Size (Standard_Integer) then
2357 Artyp := Standard_Integer;
2358 elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
2361 Artyp := Standard_Long_Long_Integer;
2365 -- Supply dummy entry at start of length array
2367 Aggr_Length (0) := Make_Artyp_Literal (0);
2369 -- Go through operands setting up the above arrays
2373 Opnd := Remove_Head (Opnds);
2374 Opnd_Typ := Etype (Opnd);
2376 -- The parent got messed up when we put the operands in a list,
2377 -- so now put back the proper parent for the saved operand.
2379 Set_Parent (Opnd, Parent (Cnode));
2381 -- Set will be True when we have setup one entry in the array
2385 -- Singleton element (or character literal) case
2387 if Base_Type (Opnd_Typ) = Ctyp then
2389 Operands (NN) := Opnd;
2390 Is_Fixed_Length (NN) := True;
2391 Fixed_Length (NN) := Uint_1;
2392 Result_May_Be_Null := False;
2394 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2395 -- since we know that the result cannot be null).
2397 Opnd_Low_Bound (NN) :=
2398 Make_Attribute_Reference (Loc,
2399 Prefix => New_Reference_To (Istyp, Loc),
2400 Attribute_Name => Name_First);
2404 -- String literal case (can only occur for strings of course)
2406 elsif Nkind (Opnd) = N_String_Literal then
2407 Len := String_Literal_Length (Opnd_Typ);
2410 Result_May_Be_Null := False;
2413 -- Capture last operand high bound if result could be null
2415 if J = N and then Result_May_Be_Null then
2416 Last_Opnd_High_Bound :=
2419 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
2420 Right_Opnd => Make_Artyp_Literal (1));
2423 -- Skip null string literal
2425 if J < N and then Len = 0 then
2430 Operands (NN) := Opnd;
2431 Is_Fixed_Length (NN) := True;
2433 -- Set length and bounds
2435 Fixed_Length (NN) := Len;
2437 Opnd_Low_Bound (NN) :=
2438 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
2445 -- Check constrained case with known bounds
2447 if Is_Constrained (Opnd_Typ) then
2449 Index : constant Node_Id := First_Index (Opnd_Typ);
2450 Indx_Typ : constant Entity_Id := Etype (Index);
2451 Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
2452 Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
2455 -- Fixed length constrained array type with known at compile
2456 -- time bounds is last case of fixed length operand.
2458 if Compile_Time_Known_Value (Lo)
2460 Compile_Time_Known_Value (Hi)
2463 Loval : constant Uint := Expr_Value (Lo);
2464 Hival : constant Uint := Expr_Value (Hi);
2465 Len : constant Uint :=
2466 UI_Max (Hival - Loval + 1, Uint_0);
2470 Result_May_Be_Null := False;
2473 -- Capture last operand bound if result could be null
2475 if J = N and then Result_May_Be_Null then
2476 Last_Opnd_High_Bound :=
2478 Make_Integer_Literal (Loc,
2479 Intval => Expr_Value (Hi)));
2482 -- Exclude null length case unless last operand
2484 if J < N and then Len = 0 then
2489 Operands (NN) := Opnd;
2490 Is_Fixed_Length (NN) := True;
2491 Fixed_Length (NN) := Len;
2493 Opnd_Low_Bound (NN) := To_Ityp (
2494 Make_Integer_Literal (Loc,
2495 Intval => Expr_Value (Lo)));
2503 -- All cases where the length is not known at compile time, or the
2504 -- special case of an operand which is known to be null but has a
2505 -- lower bound other than 1 or is other than a string type.
2510 -- Capture operand bounds
2512 Opnd_Low_Bound (NN) :=
2513 Make_Attribute_Reference (Loc,
2515 Duplicate_Subexpr (Opnd, Name_Req => True),
2516 Attribute_Name => Name_First);
2518 if J = N and Result_May_Be_Null then
2519 Last_Opnd_High_Bound :=
2521 Make_Attribute_Reference (Loc,
2523 Duplicate_Subexpr (Opnd, Name_Req => True),
2524 Attribute_Name => Name_Last));
2527 -- Capture length of operand in entity
2529 Operands (NN) := Opnd;
2530 Is_Fixed_Length (NN) := False;
2533 Make_Defining_Identifier (Loc,
2534 Chars => New_Internal_Name ('L'));
2536 Insert_Action (Cnode,
2537 Make_Object_Declaration (Loc,
2538 Defining_Identifier => Var_Length (NN),
2539 Constant_Present => True,
2541 Object_Definition =>
2542 New_Occurrence_Of (Artyp, Loc),
2545 Make_Attribute_Reference (Loc,
2547 Duplicate_Subexpr (Opnd, Name_Req => True),
2548 Attribute_Name => Name_Length)),
2550 Suppress => All_Checks);
2554 -- Set next entry in aggregate length array
2556 -- For first entry, make either integer literal for fixed length
2557 -- or a reference to the saved length for variable length.
2560 if Is_Fixed_Length (1) then
2562 Make_Integer_Literal (Loc,
2563 Intval => Fixed_Length (1));
2566 New_Reference_To (Var_Length (1), Loc);
2569 -- If entry is fixed length and only fixed lengths so far, make
2570 -- appropriate new integer literal adding new length.
2572 elsif Is_Fixed_Length (NN)
2573 and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
2576 Make_Integer_Literal (Loc,
2577 Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
2579 -- All other cases, construct an addition node for the length and
2580 -- create an entity initialized to this length.
2584 Make_Defining_Identifier (Loc,
2585 Chars => New_Internal_Name ('L'));
2587 if Is_Fixed_Length (NN) then
2588 Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
2590 Clen := New_Reference_To (Var_Length (NN), Loc);
2593 Insert_Action (Cnode,
2594 Make_Object_Declaration (Loc,
2595 Defining_Identifier => Ent,
2596 Constant_Present => True,
2598 Object_Definition =>
2599 New_Occurrence_Of (Artyp, Loc),
2603 Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
2604 Right_Opnd => Clen)),
2606 Suppress => All_Checks);
2608 Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
2615 -- If we have only skipped null operands, return the last operand
2622 -- If we have only one non-null operand, return it and we are done.
2623 -- There is one case in which this cannot be done, and that is when
2624 -- the sole operand is of the element type, in which case it must be
2625 -- converted to an array, and the easiest way of doing that is to go
2626 -- through the normal general circuit.
2629 and then Base_Type (Etype (Operands (1))) /= Ctyp
2631 Result := Operands (1);
2635 -- Cases where we have a real concatenation
2637 -- Next step is to find the low bound for the result array that we
2638 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
2640 -- If the ultimate ancestor of the index subtype is a constrained array
2641 -- definition, then the lower bound is that of the index subtype as
2642 -- specified by (RM 4.5.3(6)).
2644 -- The right test here is to go to the root type, and then the ultimate
2645 -- ancestor is the first subtype of this root type.
2647 if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
2649 Make_Attribute_Reference (Loc,
2651 New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
2652 Attribute_Name => Name_First);
2654 -- If the first operand in the list has known length we know that
2655 -- the lower bound of the result is the lower bound of this operand.
2657 elsif Is_Fixed_Length (1) then
2658 Low_Bound := Opnd_Low_Bound (1);
2660 -- OK, we don't know the lower bound, we have to build a horrible
2661 -- expression actions node of the form
2663 -- if Cond1'Length /= 0 then
2666 -- if Opnd2'Length /= 0 then
2671 -- The nesting ends either when we hit an operand whose length is known
2672 -- at compile time, or on reaching the last operand, whose low bound we
2673 -- take unconditionally whether or not it is null. It's easiest to do
2674 -- this with a recursive procedure:
2678 function Get_Known_Bound (J : Nat) return Node_Id;
2679 -- Returns the lower bound determined by operands J .. NN
2681 ---------------------
2682 -- Get_Known_Bound --
2683 ---------------------
2685 function Get_Known_Bound (J : Nat) return Node_Id is
2687 if Is_Fixed_Length (J) or else J = NN then
2688 return New_Copy (Opnd_Low_Bound (J));
2692 Make_Conditional_Expression (Loc,
2693 Expressions => New_List (
2696 Left_Opnd => New_Reference_To (Var_Length (J), Loc),
2697 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2699 New_Copy (Opnd_Low_Bound (J)),
2700 Get_Known_Bound (J + 1)));
2702 end Get_Known_Bound;
2706 Make_Defining_Identifier (Loc, Chars => New_Internal_Name ('L'));
2708 Insert_Action (Cnode,
2709 Make_Object_Declaration (Loc,
2710 Defining_Identifier => Ent,
2711 Constant_Present => True,
2712 Object_Definition => New_Occurrence_Of (Ityp, Loc),
2713 Expression => Get_Known_Bound (1)),
2714 Suppress => All_Checks);
2716 Low_Bound := New_Reference_To (Ent, Loc);
2720 -- Now we can safely compute the upper bound, normally
2721 -- Low_Bound + Length - 1.
2726 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2728 Make_Op_Subtract (Loc,
2729 Left_Opnd => New_Copy (Aggr_Length (NN)),
2730 Right_Opnd => Make_Artyp_Literal (1))));
2732 -- Now force overflow checking on High_Bound
2734 Activate_Overflow_Check (High_Bound);
2736 -- Handle the exceptional case where the result is null, in which case
2737 -- case the bounds come from the last operand (so that we get the proper
2738 -- bounds if the last operand is super-flat).
2740 if Result_May_Be_Null then
2742 Make_Conditional_Expression (Loc,
2743 Expressions => New_List (
2745 Left_Opnd => New_Copy (Aggr_Length (NN)),
2746 Right_Opnd => Make_Artyp_Literal (0)),
2747 Last_Opnd_High_Bound,
2751 -- Now we construct an array object with appropriate bounds
2754 Make_Defining_Identifier (Loc,
2755 Chars => New_Internal_Name ('S'));
2757 -- If the bound is statically known to be out of range, we do not want
2758 -- to abort, we want a warning and a runtime constraint error. Note that
2759 -- we have arranged that the result will not be treated as a static
2760 -- constant, so we won't get an illegality during this insertion.
2762 Insert_Action (Cnode,
2763 Make_Object_Declaration (Loc,
2764 Defining_Identifier => Ent,
2765 Object_Definition =>
2766 Make_Subtype_Indication (Loc,
2767 Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
2769 Make_Index_Or_Discriminant_Constraint (Loc,
2770 Constraints => New_List (
2772 Low_Bound => Low_Bound,
2773 High_Bound => High_Bound))))),
2774 Suppress => All_Checks);
2776 -- Catch the static out of range case now
2778 if Raises_Constraint_Error (High_Bound) then
2779 raise Concatenation_Error;
2782 -- Now we will generate the assignments to do the actual concatenation
2784 Known_Non_Null_Operand_Seen := False;
2786 for J in 1 .. NN loop
2788 Lo : constant Node_Id :=
2790 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2791 Right_Opnd => Aggr_Length (J - 1));
2793 Hi : constant Node_Id :=
2795 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
2797 Make_Op_Subtract (Loc,
2798 Left_Opnd => Aggr_Length (J),
2799 Right_Opnd => Make_Artyp_Literal (1)));
2802 -- Singleton case, simple assignment
2804 if Base_Type (Etype (Operands (J))) = Ctyp then
2805 Known_Non_Null_Operand_Seen := True;
2806 Insert_Action (Cnode,
2807 Make_Assignment_Statement (Loc,
2809 Make_Indexed_Component (Loc,
2810 Prefix => New_Occurrence_Of (Ent, Loc),
2811 Expressions => New_List (To_Ityp (Lo))),
2812 Expression => Operands (J)),
2813 Suppress => All_Checks);
2815 -- Array case, slice assignment, skipped when argument is fixed
2816 -- length and known to be null.
2818 elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
2821 Make_Assignment_Statement (Loc,
2825 New_Occurrence_Of (Ent, Loc),
2828 Low_Bound => To_Ityp (Lo),
2829 High_Bound => To_Ityp (Hi))),
2830 Expression => Operands (J));
2832 if Is_Fixed_Length (J) then
2833 Known_Non_Null_Operand_Seen := True;
2835 elsif not Known_Non_Null_Operand_Seen then
2837 -- Here if operand length is not statically known and no
2838 -- operand known to be non-null has been processed yet.
2839 -- If operand length is 0, we do not need to perform the
2840 -- assignment, and we must avoid the evaluation of the
2841 -- high bound of the slice, since it may underflow if the
2842 -- low bound is Ityp'First.
2845 Make_Implicit_If_Statement (Cnode,
2849 New_Occurrence_Of (Var_Length (J), Loc),
2850 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2855 Insert_Action (Cnode, Assign, Suppress => All_Checks);
2861 -- Finally we build the result, which is a reference to the array object
2863 Result := New_Reference_To (Ent, Loc);
2866 Rewrite (Cnode, Result);
2867 Analyze_And_Resolve (Cnode, Atyp);
2870 when Concatenation_Error =>
2872 -- Kill warning generated for the declaration of the static out of
2873 -- range high bound, and instead generate a Constraint_Error with
2874 -- an appropriate specific message.
2876 Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
2877 Apply_Compile_Time_Constraint_Error
2879 Msg => "concatenation result upper bound out of range?",
2880 Reason => CE_Range_Check_Failed);
2881 -- Set_Etype (Cnode, Atyp);
2882 end Expand_Concatenate;
2884 ------------------------
2885 -- Expand_N_Allocator --
2886 ------------------------
2888 procedure Expand_N_Allocator (N : Node_Id) is
2889 PtrT : constant Entity_Id := Etype (N);
2890 Dtyp : constant Entity_Id := Designated_Type (PtrT);
2891 Etyp : constant Entity_Id := Etype (Expression (N));
2892 Loc : constant Source_Ptr := Sloc (N);
2897 procedure Complete_Coextension_Finalization;
2898 -- Generate finalization calls for all nested coextensions of N. This
2899 -- routine may allocate list controllers if necessary.
2901 procedure Rewrite_Coextension (N : Node_Id);
2902 -- Static coextensions have the same lifetime as the entity they
2903 -- constrain. Such occurrences can be rewritten as aliased objects
2904 -- and their unrestricted access used instead of the coextension.
2906 ---------------------------------------
2907 -- Complete_Coextension_Finalization --
2908 ---------------------------------------
2910 procedure Complete_Coextension_Finalization is
2912 Coext_Elmt : Elmt_Id;
2916 function Inside_A_Return_Statement (N : Node_Id) return Boolean;
2917 -- Determine whether node N is part of a return statement
2919 function Needs_Initialization_Call (N : Node_Id) return Boolean;
2920 -- Determine whether node N is a subtype indicator allocator which
2921 -- acts a coextension. Such coextensions need initialization.
2923 -------------------------------
2924 -- Inside_A_Return_Statement --
2925 -------------------------------
2927 function Inside_A_Return_Statement (N : Node_Id) return Boolean is
2932 while Present (P) loop
2934 (P, N_Extended_Return_Statement, N_Simple_Return_Statement)
2938 -- Stop the traversal when we reach a subprogram body
2940 elsif Nkind (P) = N_Subprogram_Body then
2948 end Inside_A_Return_Statement;
2950 -------------------------------
2951 -- Needs_Initialization_Call --
2952 -------------------------------
2954 function Needs_Initialization_Call (N : Node_Id) return Boolean is
2958 if Nkind (N) = N_Explicit_Dereference
2959 and then Nkind (Prefix (N)) = N_Identifier
2960 and then Nkind (Parent (Entity (Prefix (N)))) =
2961 N_Object_Declaration
2963 Obj_Decl := Parent (Entity (Prefix (N)));
2966 Present (Expression (Obj_Decl))
2967 and then Nkind (Expression (Obj_Decl)) = N_Allocator
2968 and then Nkind (Expression (Expression (Obj_Decl))) /=
2969 N_Qualified_Expression;
2973 end Needs_Initialization_Call;
2975 -- Start of processing for Complete_Coextension_Finalization
2978 -- When a coextension root is inside a return statement, we need to
2979 -- use the finalization chain of the function's scope. This does not
2980 -- apply for controlled named access types because in those cases we
2981 -- can use the finalization chain of the type itself.
2983 if Inside_A_Return_Statement (N)
2985 (Ekind (PtrT) = E_Anonymous_Access_Type
2987 (Ekind (PtrT) = E_Access_Type
2988 and then No (Associated_Final_Chain (PtrT))))
2992 Outer_S : Entity_Id;
2993 S : Entity_Id := Current_Scope;
2996 while Present (S) and then S /= Standard_Standard loop
2997 if Ekind (S) = E_Function then
2998 Outer_S := Scope (S);
3000 -- Retrieve the declaration of the body
3002 Decl := Parent (Parent (
3003 Corresponding_Body (Parent (Parent (S)))));
3010 -- Push the scope of the function body since we are inserting
3011 -- the list before the body, but we are currently in the body
3012 -- itself. Override the finalization list of PtrT since the
3013 -- finalization context is now different.
3015 Push_Scope (Outer_S);
3016 Build_Final_List (Decl, PtrT);
3020 -- The root allocator may not be controlled, but it still needs a
3021 -- finalization list for all nested coextensions.
3023 elsif No (Associated_Final_Chain (PtrT)) then
3024 Build_Final_List (N, PtrT);
3028 Make_Selected_Component (Loc,
3030 New_Reference_To (Associated_Final_Chain (PtrT), Loc),
3032 Make_Identifier (Loc, Name_F));
3034 Coext_Elmt := First_Elmt (Coextensions (N));
3035 while Present (Coext_Elmt) loop
3036 Coext := Node (Coext_Elmt);
3041 if Nkind (Coext) = N_Identifier then
3043 Make_Unchecked_Type_Conversion (Loc,
3044 Subtype_Mark => New_Reference_To (Etype (Coext), Loc),
3046 Make_Explicit_Dereference (Loc,
3047 Prefix => New_Copy_Tree (Coext)));
3049 Ref := New_Copy_Tree (Coext);
3052 -- No initialization call if not allowed
3054 Check_Restriction (No_Default_Initialization, N);
3056 if not Restriction_Active (No_Default_Initialization) then
3060 -- attach_to_final_list (Ref, Flist, 2)
3062 if Needs_Initialization_Call (Coext) then
3066 Typ => Etype (Coext),
3068 With_Attach => Make_Integer_Literal (Loc, Uint_2)));
3071 -- attach_to_final_list (Ref, Flist, 2)
3077 Flist_Ref => New_Copy_Tree (Flist),
3078 With_Attach => Make_Integer_Literal (Loc, Uint_2)));
3082 Next_Elmt (Coext_Elmt);
3084 end Complete_Coextension_Finalization;
3086 -------------------------
3087 -- Rewrite_Coextension --
3088 -------------------------
3090 procedure Rewrite_Coextension (N : Node_Id) is
3091 Temp : constant Node_Id :=
3092 Make_Defining_Identifier (Loc,
3093 New_Internal_Name ('C'));
3096 -- Cnn : aliased Etyp;
3098 Decl : constant Node_Id :=
3099 Make_Object_Declaration (Loc,
3100 Defining_Identifier => Temp,
3101 Aliased_Present => True,
3102 Object_Definition =>
3103 New_Occurrence_Of (Etyp, Loc));
3107 if Nkind (Expression (N)) = N_Qualified_Expression then
3108 Set_Expression (Decl, Expression (Expression (N)));
3111 -- Find the proper insertion node for the declaration
3114 while Present (Nod) loop
3115 exit when Nkind (Nod) in N_Statement_Other_Than_Procedure_Call
3116 or else Nkind (Nod) = N_Procedure_Call_Statement
3117 or else Nkind (Nod) in N_Declaration;
3118 Nod := Parent (Nod);
3121 Insert_Before (Nod, Decl);
3125 Make_Attribute_Reference (Loc,
3126 Prefix => New_Occurrence_Of (Temp, Loc),
3127 Attribute_Name => Name_Unrestricted_Access));
3129 Analyze_And_Resolve (N, PtrT);
3130 end Rewrite_Coextension;
3132 -- Start of processing for Expand_N_Allocator
3135 -- RM E.2.3(22). We enforce that the expected type of an allocator
3136 -- shall not be a remote access-to-class-wide-limited-private type
3138 -- Why is this being done at expansion time, seems clearly wrong ???
3140 Validate_Remote_Access_To_Class_Wide_Type (N);
3142 -- Set the Storage Pool
3144 Set_Storage_Pool (N, Associated_Storage_Pool (Root_Type (PtrT)));
3146 if Present (Storage_Pool (N)) then
3147 if Is_RTE (Storage_Pool (N), RE_SS_Pool) then
3148 if VM_Target = No_VM then
3149 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3152 elsif Is_Class_Wide_Type (Etype (Storage_Pool (N))) then
3153 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3156 Set_Procedure_To_Call (N,
3157 Find_Prim_Op (Etype (Storage_Pool (N)), Name_Allocate));
3161 -- Under certain circumstances we can replace an allocator by an access
3162 -- to statically allocated storage. The conditions, as noted in AARM
3163 -- 3.10 (10c) are as follows:
3165 -- Size and initial value is known at compile time
3166 -- Access type is access-to-constant
3168 -- The allocator is not part of a constraint on a record component,
3169 -- because in that case the inserted actions are delayed until the
3170 -- record declaration is fully analyzed, which is too late for the
3171 -- analysis of the rewritten allocator.
3173 if Is_Access_Constant (PtrT)
3174 and then Nkind (Expression (N)) = N_Qualified_Expression
3175 and then Compile_Time_Known_Value (Expression (Expression (N)))
3176 and then Size_Known_At_Compile_Time (Etype (Expression
3178 and then not Is_Record_Type (Current_Scope)
3180 -- Here we can do the optimization. For the allocator
3184 -- We insert an object declaration
3186 -- Tnn : aliased x := y;
3188 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3189 -- marked as requiring static allocation.
3192 Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3194 Desig := Subtype_Mark (Expression (N));
3196 -- If context is constrained, use constrained subtype directly,
3197 -- so that the constant is not labelled as having a nominally
3198 -- unconstrained subtype.
3200 if Entity (Desig) = Base_Type (Dtyp) then
3201 Desig := New_Occurrence_Of (Dtyp, Loc);
3205 Make_Object_Declaration (Loc,
3206 Defining_Identifier => Temp,
3207 Aliased_Present => True,
3208 Constant_Present => Is_Access_Constant (PtrT),
3209 Object_Definition => Desig,
3210 Expression => Expression (Expression (N))));
3213 Make_Attribute_Reference (Loc,
3214 Prefix => New_Occurrence_Of (Temp, Loc),
3215 Attribute_Name => Name_Unrestricted_Access));
3217 Analyze_And_Resolve (N, PtrT);
3219 -- We set the variable as statically allocated, since we don't want
3220 -- it going on the stack of the current procedure!
3222 Set_Is_Statically_Allocated (Temp);
3226 -- Same if the allocator is an access discriminant for a local object:
3227 -- instead of an allocator we create a local value and constrain the
3228 -- the enclosing object with the corresponding access attribute.
3230 if Is_Static_Coextension (N) then
3231 Rewrite_Coextension (N);
3235 -- The current allocator creates an object which may contain nested
3236 -- coextensions. Use the current allocator's finalization list to
3237 -- generate finalization call for all nested coextensions.
3239 if Is_Coextension_Root (N) then
3240 Complete_Coextension_Finalization;
3243 -- Handle case of qualified expression (other than optimization above)
3245 if Nkind (Expression (N)) = N_Qualified_Expression then
3246 Expand_Allocator_Expression (N);
3250 -- If the allocator is for a type which requires initialization, and
3251 -- there is no initial value (i.e. operand is a subtype indication
3252 -- rather than a qualified expression), then we must generate a call to
3253 -- the initialization routine using an expressions action node:
3255 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3257 -- Here ptr_T is the pointer type for the allocator, and T is the
3258 -- subtype of the allocator. A special case arises if the designated
3259 -- type of the access type is a task or contains tasks. In this case
3260 -- the call to Init (Temp.all ...) is replaced by code that ensures
3261 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3262 -- for details). In addition, if the type T is a task T, then the
3263 -- first argument to Init must be converted to the task record type.
3266 T : constant Entity_Id := Entity (Expression (N));
3274 Temp_Decl : Node_Id;
3275 Temp_Type : Entity_Id;
3276 Attach_Level : Uint;
3279 if No_Initialization (N) then
3282 -- Case of no initialization procedure present
3284 elsif not Has_Non_Null_Base_Init_Proc (T) then
3286 -- Case of simple initialization required
3288 if Needs_Simple_Initialization (T) then
3289 Check_Restriction (No_Default_Initialization, N);
3290 Rewrite (Expression (N),
3291 Make_Qualified_Expression (Loc,
3292 Subtype_Mark => New_Occurrence_Of (T, Loc),
3293 Expression => Get_Simple_Init_Val (T, N)));
3295 Analyze_And_Resolve (Expression (Expression (N)), T);
3296 Analyze_And_Resolve (Expression (N), T);
3297 Set_Paren_Count (Expression (Expression (N)), 1);
3298 Expand_N_Allocator (N);
3300 -- No initialization required
3306 -- Case of initialization procedure present, must be called
3309 Check_Restriction (No_Default_Initialization, N);
3311 if not Restriction_Active (No_Default_Initialization) then
3312 Init := Base_Init_Proc (T);
3314 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
3316 -- Construct argument list for the initialization routine call
3319 Make_Explicit_Dereference (Loc,
3320 Prefix => New_Reference_To (Temp, Loc));
3321 Set_Assignment_OK (Arg1);
3324 -- The initialization procedure expects a specific type. if the
3325 -- context is access to class wide, indicate that the object
3326 -- being allocated has the right specific type.
3328 if Is_Class_Wide_Type (Dtyp) then
3329 Arg1 := Unchecked_Convert_To (T, Arg1);
3332 -- If designated type is a concurrent type or if it is private
3333 -- type whose definition is a concurrent type, the first
3334 -- argument in the Init routine has to be unchecked conversion
3335 -- to the corresponding record type. If the designated type is
3336 -- a derived type, we also convert the argument to its root
3339 if Is_Concurrent_Type (T) then
3341 Unchecked_Convert_To (Corresponding_Record_Type (T), Arg1);
3343 elsif Is_Private_Type (T)
3344 and then Present (Full_View (T))
3345 and then Is_Concurrent_Type (Full_View (T))
3348 Unchecked_Convert_To
3349 (Corresponding_Record_Type (Full_View (T)), Arg1);
3351 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3353 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3355 Arg1 := OK_Convert_To (Etype (Ftyp), Arg1);
3356 Set_Etype (Arg1, Ftyp);
3360 Args := New_List (Arg1);
3362 -- For the task case, pass the Master_Id of the access type as
3363 -- the value of the _Master parameter, and _Chain as the value
3364 -- of the _Chain parameter (_Chain will be defined as part of
3365 -- the generated code for the allocator).
3367 -- In Ada 2005, the context may be a function that returns an
3368 -- anonymous access type. In that case the Master_Id has been
3369 -- created when expanding the function declaration.
3371 if Has_Task (T) then
3372 if No (Master_Id (Base_Type (PtrT))) then
3374 -- If we have a non-library level task with restriction
3375 -- No_Task_Hierarchy set, then no point in expanding.
3377 if not Is_Library_Level_Entity (T)
3378 and then Restriction_Active (No_Task_Hierarchy)
3383 -- The designated type was an incomplete type, and the
3384 -- access type did not get expanded. Salvage it now.
3386 pragma Assert (Present (Parent (Base_Type (PtrT))));
3387 Expand_N_Full_Type_Declaration
3388 (Parent (Base_Type (PtrT)));
3391 -- If the context of the allocator is a declaration or an
3392 -- assignment, we can generate a meaningful image for it,
3393 -- even though subsequent assignments might remove the
3394 -- connection between task and entity. We build this image
3395 -- when the left-hand side is a simple variable, a simple
3396 -- indexed assignment or a simple selected component.
3398 if Nkind (Parent (N)) = N_Assignment_Statement then
3400 Nam : constant Node_Id := Name (Parent (N));
3403 if Is_Entity_Name (Nam) then
3405 Build_Task_Image_Decls
3408 (Entity (Nam), Sloc (Nam)), T);
3411 (Nam, N_Indexed_Component, N_Selected_Component)
3412 and then Is_Entity_Name (Prefix (Nam))
3415 Build_Task_Image_Decls
3416 (Loc, Nam, Etype (Prefix (Nam)));
3418 Decls := Build_Task_Image_Decls (Loc, T, T);
3422 elsif Nkind (Parent (N)) = N_Object_Declaration then
3424 Build_Task_Image_Decls
3425 (Loc, Defining_Identifier (Parent (N)), T);
3428 Decls := Build_Task_Image_Decls (Loc, T, T);
3433 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3434 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3436 Decl := Last (Decls);
3438 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3440 -- Has_Task is false, Decls not used
3446 -- Add discriminants if discriminated type
3449 Dis : Boolean := False;
3453 if Has_Discriminants (T) then
3457 elsif Is_Private_Type (T)
3458 and then Present (Full_View (T))
3459 and then Has_Discriminants (Full_View (T))
3462 Typ := Full_View (T);
3467 -- If the allocated object will be constrained by the
3468 -- default values for discriminants, then build a subtype
3469 -- with those defaults, and change the allocated subtype
3470 -- to that. Note that this happens in fewer cases in Ada
3473 if not Is_Constrained (Typ)
3474 and then Present (Discriminant_Default_Value
3475 (First_Discriminant (Typ)))
3476 and then (Ada_Version < Ada_05
3478 not Has_Constrained_Partial_View (Typ))
3480 Typ := Build_Default_Subtype (Typ, N);
3481 Set_Expression (N, New_Reference_To (Typ, Loc));
3484 Discr := First_Elmt (Discriminant_Constraint (Typ));
3485 while Present (Discr) loop
3486 Nod := Node (Discr);
3487 Append (New_Copy_Tree (Node (Discr)), Args);
3489 -- AI-416: when the discriminant constraint is an
3490 -- anonymous access type make sure an accessibility
3491 -- check is inserted if necessary (3.10.2(22.q/2))
3493 if Ada_Version >= Ada_05
3495 Ekind (Etype (Nod)) = E_Anonymous_Access_Type
3497 Apply_Accessibility_Check
3498 (Nod, Typ, Insert_Node => Nod);
3506 -- We set the allocator as analyzed so that when we analyze the
3507 -- expression actions node, we do not get an unwanted recursive
3508 -- expansion of the allocator expression.
3510 Set_Analyzed (N, True);
3511 Nod := Relocate_Node (N);
3513 -- Here is the transformation:
3515 -- output: Temp : constant ptr_T := new T;
3516 -- Init (Temp.all, ...);
3517 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
3518 -- <CTRL> Initialize (Finalizable (Temp.all));
3520 -- Here ptr_T is the pointer type for the allocator, and is the
3521 -- subtype of the allocator.
3524 Make_Object_Declaration (Loc,
3525 Defining_Identifier => Temp,
3526 Constant_Present => True,
3527 Object_Definition => New_Reference_To (Temp_Type, Loc),
3530 Set_Assignment_OK (Temp_Decl);
3531 Insert_Action (N, Temp_Decl, Suppress => All_Checks);
3533 -- If the designated type is a task type or contains tasks,
3534 -- create block to activate created tasks, and insert
3535 -- declaration for Task_Image variable ahead of call.
3537 if Has_Task (T) then
3539 L : constant List_Id := New_List;
3542 Build_Task_Allocate_Block (L, Nod, Args);
3544 Insert_List_Before (First (Declarations (Blk)), Decls);
3545 Insert_Actions (N, L);
3550 Make_Procedure_Call_Statement (Loc,
3551 Name => New_Reference_To (Init, Loc),
3552 Parameter_Associations => Args));
3555 if Needs_Finalization (T) then
3557 -- Postpone the generation of a finalization call for the
3558 -- current allocator if it acts as a coextension.
3560 if Is_Dynamic_Coextension (N) then
3561 if No (Coextensions (N)) then
3562 Set_Coextensions (N, New_Elmt_List);
3565 Append_Elmt (New_Copy_Tree (Arg1), Coextensions (N));
3569 Get_Allocator_Final_List (N, Base_Type (T), PtrT);
3571 -- Anonymous access types created for access parameters
3572 -- are attached to an explicitly constructed controller,
3573 -- which ensures that they can be finalized properly,
3574 -- even if their deallocation might not happen. The list
3575 -- associated with the controller is doubly-linked. For
3576 -- other anonymous access types, the object may end up
3577 -- on the global final list which is singly-linked.
3578 -- Work needed for access discriminants in Ada 2005 ???
3580 if Ekind (PtrT) = E_Anonymous_Access_Type
3582 Nkind (Associated_Node_For_Itype (PtrT))
3583 not in N_Subprogram_Specification
3585 Attach_Level := Uint_1;
3587 Attach_Level := Uint_2;
3592 Ref => New_Copy_Tree (Arg1),
3595 With_Attach => Make_Integer_Literal (Loc,
3596 Intval => Attach_Level)));
3600 Rewrite (N, New_Reference_To (Temp, Loc));
3601 Analyze_And_Resolve (N, PtrT);
3606 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
3607 -- object that has been rewritten as a reference, we displace "this"
3608 -- to reference properly its secondary dispatch table.
3610 if Nkind (N) = N_Identifier
3611 and then Is_Interface (Dtyp)
3613 Displace_Allocator_Pointer (N);
3617 when RE_Not_Available =>
3619 end Expand_N_Allocator;
3621 -----------------------
3622 -- Expand_N_And_Then --
3623 -----------------------
3625 -- Expand into conditional expression if Actions present, and also deal
3626 -- with optimizing case of arguments being True or False.
3628 procedure Expand_N_And_Then (N : Node_Id) is
3629 Loc : constant Source_Ptr := Sloc (N);
3630 Typ : constant Entity_Id := Etype (N);
3631 Left : constant Node_Id := Left_Opnd (N);
3632 Right : constant Node_Id := Right_Opnd (N);
3636 -- Deal with non-standard booleans
3638 if Is_Boolean_Type (Typ) then
3639 Adjust_Condition (Left);
3640 Adjust_Condition (Right);
3641 Set_Etype (N, Standard_Boolean);
3644 -- Check for cases where left argument is known to be True or False
3646 if Compile_Time_Known_Value (Left) then
3648 -- If left argument is True, change (True and then Right) to Right.
3649 -- Any actions associated with Right will be executed unconditionally
3650 -- and can thus be inserted into the tree unconditionally.
3652 if Expr_Value_E (Left) = Standard_True then
3653 if Present (Actions (N)) then
3654 Insert_Actions (N, Actions (N));
3659 -- If left argument is False, change (False and then Right) to False.
3660 -- In this case we can forget the actions associated with Right,
3661 -- since they will never be executed.
3663 else pragma Assert (Expr_Value_E (Left) = Standard_False);
3664 Kill_Dead_Code (Right);
3665 Kill_Dead_Code (Actions (N));
3666 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3669 Adjust_Result_Type (N, Typ);
3673 -- If Actions are present, we expand
3675 -- left and then right
3679 -- if left then right else false end
3681 -- with the actions becoming the Then_Actions of the conditional
3682 -- expression. This conditional expression is then further expanded
3683 -- (and will eventually disappear)
3685 if Present (Actions (N)) then
3686 Actlist := Actions (N);
3688 Make_Conditional_Expression (Loc,
3689 Expressions => New_List (
3692 New_Occurrence_Of (Standard_False, Loc))));
3694 Set_Then_Actions (N, Actlist);
3695 Analyze_And_Resolve (N, Standard_Boolean);
3696 Adjust_Result_Type (N, Typ);
3700 -- No actions present, check for cases of right argument True/False
3702 if Compile_Time_Known_Value (Right) then
3704 -- Change (Left and then True) to Left. Note that we know there are
3705 -- no actions associated with the True operand, since we just checked
3706 -- for this case above.
3708 if Expr_Value_E (Right) = Standard_True then
3711 -- Change (Left and then False) to False, making sure to preserve any
3712 -- side effects associated with the Left operand.
3714 else pragma Assert (Expr_Value_E (Right) = Standard_False);
3715 Remove_Side_Effects (Left);
3717 (N, New_Occurrence_Of (Standard_False, Loc));
3721 Adjust_Result_Type (N, Typ);
3722 end Expand_N_And_Then;
3724 -------------------------------------
3725 -- Expand_N_Conditional_Expression --
3726 -------------------------------------
3728 -- Expand into expression actions if then/else actions present
3730 procedure Expand_N_Conditional_Expression (N : Node_Id) is
3731 Loc : constant Source_Ptr := Sloc (N);
3732 Cond : constant Node_Id := First (Expressions (N));
3733 Thenx : constant Node_Id := Next (Cond);
3734 Elsex : constant Node_Id := Next (Thenx);
3735 Typ : constant Entity_Id := Etype (N);
3740 -- If either then or else actions are present, then given:
3742 -- if cond then then-expr else else-expr end
3744 -- we insert the following sequence of actions (using Insert_Actions):
3749 -- Cnn := then-expr;
3755 -- and replace the conditional expression by a reference to Cnn
3757 if Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
3758 Cnn := Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
3761 Make_Implicit_If_Statement (N,
3762 Condition => Relocate_Node (Cond),
3764 Then_Statements => New_List (
3765 Make_Assignment_Statement (Sloc (Thenx),
3766 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
3767 Expression => Relocate_Node (Thenx))),
3769 Else_Statements => New_List (
3770 Make_Assignment_Statement (Sloc (Elsex),
3771 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
3772 Expression => Relocate_Node (Elsex))));
3774 Set_Assignment_OK (Name (First (Then_Statements (New_If))));
3775 Set_Assignment_OK (Name (First (Else_Statements (New_If))));
3777 if Present (Then_Actions (N)) then
3779 (First (Then_Statements (New_If)), Then_Actions (N));
3782 if Present (Else_Actions (N)) then
3784 (First (Else_Statements (New_If)), Else_Actions (N));
3787 Rewrite (N, New_Occurrence_Of (Cnn, Loc));
3790 Make_Object_Declaration (Loc,
3791 Defining_Identifier => Cnn,
3792 Object_Definition => New_Occurrence_Of (Typ, Loc)));
3794 Insert_Action (N, New_If);
3795 Analyze_And_Resolve (N, Typ);
3797 end Expand_N_Conditional_Expression;
3799 -----------------------------------
3800 -- Expand_N_Explicit_Dereference --
3801 -----------------------------------
3803 procedure Expand_N_Explicit_Dereference (N : Node_Id) is
3805 -- Insert explicit dereference call for the checked storage pool case
3807 Insert_Dereference_Action (Prefix (N));
3808 end Expand_N_Explicit_Dereference;
3814 procedure Expand_N_In (N : Node_Id) is
3815 Loc : constant Source_Ptr := Sloc (N);
3816 Rtyp : constant Entity_Id := Etype (N);
3817 Lop : constant Node_Id := Left_Opnd (N);
3818 Rop : constant Node_Id := Right_Opnd (N);
3819 Static : constant Boolean := Is_OK_Static_Expression (N);
3821 procedure Substitute_Valid_Check;
3822 -- Replaces node N by Lop'Valid. This is done when we have an explicit
3823 -- test for the left operand being in range of its subtype.
3825 ----------------------------
3826 -- Substitute_Valid_Check --
3827 ----------------------------
3829 procedure Substitute_Valid_Check is
3832 Make_Attribute_Reference (Loc,
3833 Prefix => Relocate_Node (Lop),
3834 Attribute_Name => Name_Valid));
3836 Analyze_And_Resolve (N, Rtyp);
3838 Error_Msg_N ("?explicit membership test may be optimized away", N);
3839 Error_Msg_N ("\?use ''Valid attribute instead", N);
3841 end Substitute_Valid_Check;
3843 -- Start of processing for Expand_N_In
3846 -- Check case of explicit test for an expression in range of its
3847 -- subtype. This is suspicious usage and we replace it with a 'Valid
3848 -- test and give a warning.
3850 if Is_Scalar_Type (Etype (Lop))
3851 and then Nkind (Rop) in N_Has_Entity
3852 and then Etype (Lop) = Entity (Rop)
3853 and then Comes_From_Source (N)
3854 and then VM_Target = No_VM
3856 Substitute_Valid_Check;
3860 -- Do validity check on operands
3862 if Validity_Checks_On and Validity_Check_Operands then
3863 Ensure_Valid (Left_Opnd (N));
3864 Validity_Check_Range (Right_Opnd (N));
3867 -- Case of explicit range
3869 if Nkind (Rop) = N_Range then
3871 Lo : constant Node_Id := Low_Bound (Rop);
3872 Hi : constant Node_Id := High_Bound (Rop);
3874 Ltyp : constant Entity_Id := Etype (Lop);
3876 Lo_Orig : constant Node_Id := Original_Node (Lo);
3877 Hi_Orig : constant Node_Id := Original_Node (Hi);
3879 Lcheck : Compare_Result;
3880 Ucheck : Compare_Result;
3882 Warn1 : constant Boolean :=
3883 Constant_Condition_Warnings
3884 and then Comes_From_Source (N)
3885 and then not In_Instance;
3886 -- This must be true for any of the optimization warnings, we
3887 -- clearly want to give them only for source with the flag on.
3888 -- We also skip these warnings in an instance since it may be
3889 -- the case that different instantiations have different ranges.
3891 Warn2 : constant Boolean :=
3893 and then Nkind (Original_Node (Rop)) = N_Range
3894 and then Is_Integer_Type (Etype (Lo));
3895 -- For the case where only one bound warning is elided, we also
3896 -- insist on an explicit range and an integer type. The reason is
3897 -- that the use of enumeration ranges including an end point is
3898 -- common, as is the use of a subtype name, one of whose bounds
3899 -- is the same as the type of the expression.
3902 -- If test is explicit x'first .. x'last, replace by valid check
3904 if Is_Scalar_Type (Ltyp)
3905 and then Nkind (Lo_Orig) = N_Attribute_Reference
3906 and then Attribute_Name (Lo_Orig) = Name_First
3907 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
3908 and then Entity (Prefix (Lo_Orig)) = Ltyp
3909 and then Nkind (Hi_Orig) = N_Attribute_Reference
3910 and then Attribute_Name (Hi_Orig) = Name_Last
3911 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
3912 and then Entity (Prefix (Hi_Orig)) = Ltyp
3913 and then Comes_From_Source (N)
3914 and then VM_Target = No_VM
3916 Substitute_Valid_Check;
3920 -- If bounds of type are known at compile time, and the end points
3921 -- are known at compile time and identical, this is another case
3922 -- for substituting a valid test. We only do this for discrete
3923 -- types, since it won't arise in practice for float types.
3925 if Comes_From_Source (N)
3926 and then Is_Discrete_Type (Ltyp)
3927 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
3928 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
3929 and then Compile_Time_Known_Value (Lo)
3930 and then Compile_Time_Known_Value (Hi)
3931 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
3932 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
3934 -- Kill warnings in instances, since they may be cases where we
3935 -- have a test in the generic that makes sense with some types
3936 -- and not with other types.
3938 and then not In_Instance
3940 Substitute_Valid_Check;
3944 -- If we have an explicit range, do a bit of optimization based
3945 -- on range analysis (we may be able to kill one or both checks).
3947 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
3948 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
3950 -- If either check is known to fail, replace result by False since
3951 -- the other check does not matter. Preserve the static flag for
3952 -- legality checks, because we are constant-folding beyond RM 4.9.
3954 if Lcheck = LT or else Ucheck = GT then
3956 Error_Msg_N ("?range test optimized away", N);
3957 Error_Msg_N ("\?value is known to be out of range", N);
3961 New_Reference_To (Standard_False, Loc));
3962 Analyze_And_Resolve (N, Rtyp);
3963 Set_Is_Static_Expression (N, Static);
3967 -- If both checks are known to succeed, replace result by True,
3968 -- since we know we are in range.
3970 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
3972 Error_Msg_N ("?range test optimized away", N);
3973 Error_Msg_N ("\?value is known to be in range", N);
3977 New_Reference_To (Standard_True, Loc));
3978 Analyze_And_Resolve (N, Rtyp);
3979 Set_Is_Static_Expression (N, Static);
3983 -- If lower bound check succeeds and upper bound check is not
3984 -- known to succeed or fail, then replace the range check with
3985 -- a comparison against the upper bound.
3987 elsif Lcheck in Compare_GE then
3988 if Warn2 and then not In_Instance then
3989 Error_Msg_N ("?lower bound test optimized away", Lo);
3990 Error_Msg_N ("\?value is known to be in range", Lo);
3996 Right_Opnd => High_Bound (Rop)));
3997 Analyze_And_Resolve (N, Rtyp);
4001 -- If upper bound check succeeds and lower bound check is not
4002 -- known to succeed or fail, then replace the range check with
4003 -- a comparison against the lower bound.
4005 elsif Ucheck in Compare_LE then
4006 if Warn2 and then not In_Instance then
4007 Error_Msg_N ("?upper bound test optimized away", Hi);
4008 Error_Msg_N ("\?value is known to be in range", Hi);
4014 Right_Opnd => Low_Bound (Rop)));
4015 Analyze_And_Resolve (N, Rtyp);
4020 -- We couldn't optimize away the range check, but there is one
4021 -- more issue. If we are checking constant conditionals, then we
4022 -- see if we can determine the outcome assuming everything is
4023 -- valid, and if so give an appropriate warning.
4025 if Warn1 and then not Assume_No_Invalid_Values then
4026 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4027 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4029 -- Result is out of range for valid value
4031 if Lcheck = LT or else Ucheck = GT then
4033 ("?value can only be in range if it is invalid", N);
4035 -- Result is in range for valid value
4037 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4039 ("?value can only be out of range if it is invalid", N);
4041 -- Lower bound check succeeds if value is valid
4043 elsif Warn2 and then Lcheck in Compare_GE then
4045 ("?lower bound check only fails if it is invalid", Lo);
4047 -- Upper bound check succeeds if value is valid
4049 elsif Warn2 and then Ucheck in Compare_LE then
4051 ("?upper bound check only fails for invalid values", Hi);
4056 -- For all other cases of an explicit range, nothing to be done
4060 -- Here right operand is a subtype mark
4064 Typ : Entity_Id := Etype (Rop);
4065 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4066 Obj : Node_Id := Lop;
4067 Cond : Node_Id := Empty;
4070 Remove_Side_Effects (Obj);
4072 -- For tagged type, do tagged membership operation
4074 if Is_Tagged_Type (Typ) then
4076 -- No expansion will be performed when VM_Target, as the VM
4077 -- back-ends will handle the membership tests directly (tags
4078 -- are not explicitly represented in Java objects, so the
4079 -- normal tagged membership expansion is not what we want).
4081 if VM_Target = No_VM then
4082 Rewrite (N, Tagged_Membership (N));
4083 Analyze_And_Resolve (N, Rtyp);
4088 -- If type is scalar type, rewrite as x in t'first .. t'last.
4089 -- This reason we do this is that the bounds may have the wrong
4090 -- type if they come from the original type definition. Also this
4091 -- way we get all the processing above for an explicit range.
4093 elsif Is_Scalar_Type (Typ) then
4097 Make_Attribute_Reference (Loc,
4098 Attribute_Name => Name_First,
4099 Prefix => New_Reference_To (Typ, Loc)),
4102 Make_Attribute_Reference (Loc,
4103 Attribute_Name => Name_Last,
4104 Prefix => New_Reference_To (Typ, Loc))));
4105 Analyze_And_Resolve (N, Rtyp);
4108 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4109 -- a membership test if the subtype mark denotes a constrained
4110 -- Unchecked_Union subtype and the expression lacks inferable
4113 elsif Is_Unchecked_Union (Base_Type (Typ))
4114 and then Is_Constrained (Typ)
4115 and then not Has_Inferable_Discriminants (Lop)
4118 Make_Raise_Program_Error (Loc,
4119 Reason => PE_Unchecked_Union_Restriction));
4121 -- Prevent Gigi from generating incorrect code by rewriting
4122 -- the test as a standard False.
4125 New_Occurrence_Of (Standard_False, Loc));
4130 -- Here we have a non-scalar type
4133 Typ := Designated_Type (Typ);
4136 if not Is_Constrained (Typ) then
4138 New_Reference_To (Standard_True, Loc));
4139 Analyze_And_Resolve (N, Rtyp);
4141 -- For the constrained array case, we have to check the subscripts
4142 -- for an exact match if the lengths are non-zero (the lengths
4143 -- must match in any case).
4145 elsif Is_Array_Type (Typ) then
4147 Check_Subscripts : declare
4148 function Construct_Attribute_Reference
4151 Dim : Nat) return Node_Id;
4152 -- Build attribute reference E'Nam(Dim)
4154 -----------------------------------
4155 -- Construct_Attribute_Reference --
4156 -----------------------------------
4158 function Construct_Attribute_Reference
4161 Dim : Nat) return Node_Id
4165 Make_Attribute_Reference (Loc,
4167 Attribute_Name => Nam,
4168 Expressions => New_List (
4169 Make_Integer_Literal (Loc, Dim)));
4170 end Construct_Attribute_Reference;
4172 -- Start processing for Check_Subscripts
4175 for J in 1 .. Number_Dimensions (Typ) loop
4176 Evolve_And_Then (Cond,
4179 Construct_Attribute_Reference
4180 (Duplicate_Subexpr_No_Checks (Obj),
4183 Construct_Attribute_Reference
4184 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
4186 Evolve_And_Then (Cond,
4189 Construct_Attribute_Reference
4190 (Duplicate_Subexpr_No_Checks (Obj),
4193 Construct_Attribute_Reference
4194 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
4203 Right_Opnd => Make_Null (Loc)),
4204 Right_Opnd => Cond);
4208 Analyze_And_Resolve (N, Rtyp);
4209 end Check_Subscripts;
4211 -- These are the cases where constraint checks may be required,
4212 -- e.g. records with possible discriminants
4215 -- Expand the test into a series of discriminant comparisons.
4216 -- The expression that is built is the negation of the one that
4217 -- is used for checking discriminant constraints.
4219 Obj := Relocate_Node (Left_Opnd (N));
4221 if Has_Discriminants (Typ) then
4222 Cond := Make_Op_Not (Loc,
4223 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
4226 Cond := Make_Or_Else (Loc,
4230 Right_Opnd => Make_Null (Loc)),
4231 Right_Opnd => Cond);
4235 Cond := New_Occurrence_Of (Standard_True, Loc);
4239 Analyze_And_Resolve (N, Rtyp);
4245 --------------------------------
4246 -- Expand_N_Indexed_Component --
4247 --------------------------------
4249 procedure Expand_N_Indexed_Component (N : Node_Id) is
4250 Loc : constant Source_Ptr := Sloc (N);
4251 Typ : constant Entity_Id := Etype (N);
4252 P : constant Node_Id := Prefix (N);
4253 T : constant Entity_Id := Etype (P);
4256 -- A special optimization, if we have an indexed component that is
4257 -- selecting from a slice, then we can eliminate the slice, since, for
4258 -- example, x (i .. j)(k) is identical to x(k). The only difference is
4259 -- the range check required by the slice. The range check for the slice
4260 -- itself has already been generated. The range check for the
4261 -- subscripting operation is ensured by converting the subject to
4262 -- the subtype of the slice.
4264 -- This optimization not only generates better code, avoiding slice
4265 -- messing especially in the packed case, but more importantly bypasses
4266 -- some problems in handling this peculiar case, for example, the issue
4267 -- of dealing specially with object renamings.
4269 if Nkind (P) = N_Slice then
4271 Make_Indexed_Component (Loc,
4272 Prefix => Prefix (P),
4273 Expressions => New_List (
4275 (Etype (First_Index (Etype (P))),
4276 First (Expressions (N))))));
4277 Analyze_And_Resolve (N, Typ);
4281 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
4282 -- function, then additional actuals must be passed.
4284 if Ada_Version >= Ada_05
4285 and then Is_Build_In_Place_Function_Call (P)
4287 Make_Build_In_Place_Call_In_Anonymous_Context (P);
4290 -- If the prefix is an access type, then we unconditionally rewrite if
4291 -- as an explicit deference. This simplifies processing for several
4292 -- cases, including packed array cases and certain cases in which checks
4293 -- must be generated. We used to try to do this only when it was
4294 -- necessary, but it cleans up the code to do it all the time.
4296 if Is_Access_Type (T) then
4297 Insert_Explicit_Dereference (P);
4298 Analyze_And_Resolve (P, Designated_Type (T));
4301 -- Generate index and validity checks
4303 Generate_Index_Checks (N);
4305 if Validity_Checks_On and then Validity_Check_Subscripts then
4306 Apply_Subscript_Validity_Checks (N);
4309 -- All done for the non-packed case
4311 if not Is_Packed (Etype (Prefix (N))) then
4315 -- For packed arrays that are not bit-packed (i.e. the case of an array
4316 -- with one or more index types with a non-contiguous enumeration type),
4317 -- we can always use the normal packed element get circuit.
4319 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
4320 Expand_Packed_Element_Reference (N);
4324 -- For a reference to a component of a bit packed array, we have to
4325 -- convert it to a reference to the corresponding Packed_Array_Type.
4326 -- We only want to do this for simple references, and not for:
4328 -- Left side of assignment, or prefix of left side of assignment, or
4329 -- prefix of the prefix, to handle packed arrays of packed arrays,
4330 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
4332 -- Renaming objects in renaming associations
4333 -- This case is handled when a use of the renamed variable occurs
4335 -- Actual parameters for a procedure call
4336 -- This case is handled in Exp_Ch6.Expand_Actuals
4338 -- The second expression in a 'Read attribute reference
4340 -- The prefix of an address or size attribute reference
4342 -- The following circuit detects these exceptions
4345 Child : Node_Id := N;
4346 Parnt : Node_Id := Parent (N);
4350 if Nkind (Parnt) = N_Unchecked_Expression then
4353 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
4354 N_Procedure_Call_Statement)
4355 or else (Nkind (Parnt) = N_Parameter_Association
4357 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
4361 elsif Nkind (Parnt) = N_Attribute_Reference
4362 and then (Attribute_Name (Parnt) = Name_Address
4364 Attribute_Name (Parnt) = Name_Size)
4365 and then Prefix (Parnt) = Child
4369 elsif Nkind (Parnt) = N_Assignment_Statement
4370 and then Name (Parnt) = Child
4374 -- If the expression is an index of an indexed component, it must
4375 -- be expanded regardless of context.
4377 elsif Nkind (Parnt) = N_Indexed_Component
4378 and then Child /= Prefix (Parnt)
4380 Expand_Packed_Element_Reference (N);
4383 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
4384 and then Name (Parent (Parnt)) = Parnt
4388 elsif Nkind (Parnt) = N_Attribute_Reference
4389 and then Attribute_Name (Parnt) = Name_Read
4390 and then Next (First (Expressions (Parnt))) = Child
4394 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
4395 and then Prefix (Parnt) = Child
4400 Expand_Packed_Element_Reference (N);
4404 -- Keep looking up tree for unchecked expression, or if we are the
4405 -- prefix of a possible assignment left side.
4408 Parnt := Parent (Child);
4411 end Expand_N_Indexed_Component;
4413 ---------------------
4414 -- Expand_N_Not_In --
4415 ---------------------
4417 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
4418 -- can be done. This avoids needing to duplicate this expansion code.
4420 procedure Expand_N_Not_In (N : Node_Id) is
4421 Loc : constant Source_Ptr := Sloc (N);
4422 Typ : constant Entity_Id := Etype (N);
4423 Cfs : constant Boolean := Comes_From_Source (N);
4430 Left_Opnd => Left_Opnd (N),
4431 Right_Opnd => Right_Opnd (N))));
4433 -- We want this to appear as coming from source if original does (see
4434 -- transformations in Expand_N_In).
4436 Set_Comes_From_Source (N, Cfs);
4437 Set_Comes_From_Source (Right_Opnd (N), Cfs);
4439 -- Now analyze transformed node
4441 Analyze_And_Resolve (N, Typ);
4442 end Expand_N_Not_In;
4448 -- The only replacement required is for the case of a null of type that is
4449 -- an access to protected subprogram. We represent such access values as a
4450 -- record, and so we must replace the occurrence of null by the equivalent
4451 -- record (with a null address and a null pointer in it), so that the
4452 -- backend creates the proper value.
4454 procedure Expand_N_Null (N : Node_Id) is
4455 Loc : constant Source_Ptr := Sloc (N);
4456 Typ : constant Entity_Id := Etype (N);
4460 if Is_Access_Protected_Subprogram_Type (Typ) then
4462 Make_Aggregate (Loc,
4463 Expressions => New_List (
4464 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
4468 Analyze_And_Resolve (N, Equivalent_Type (Typ));
4470 -- For subsequent semantic analysis, the node must retain its type.
4471 -- Gigi in any case replaces this type by the corresponding record
4472 -- type before processing the node.
4478 when RE_Not_Available =>
4482 ---------------------
4483 -- Expand_N_Op_Abs --
4484 ---------------------
4486 procedure Expand_N_Op_Abs (N : Node_Id) is
4487 Loc : constant Source_Ptr := Sloc (N);
4488 Expr : constant Node_Id := Right_Opnd (N);
4491 Unary_Op_Validity_Checks (N);
4493 -- Deal with software overflow checking
4495 if not Backend_Overflow_Checks_On_Target
4496 and then Is_Signed_Integer_Type (Etype (N))
4497 and then Do_Overflow_Check (N)
4499 -- The only case to worry about is when the argument is equal to the
4500 -- largest negative number, so what we do is to insert the check:
4502 -- [constraint_error when Expr = typ'Base'First]
4504 -- with the usual Duplicate_Subexpr use coding for expr
4507 Make_Raise_Constraint_Error (Loc,
4510 Left_Opnd => Duplicate_Subexpr (Expr),
4512 Make_Attribute_Reference (Loc,
4514 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
4515 Attribute_Name => Name_First)),
4516 Reason => CE_Overflow_Check_Failed));
4519 -- Vax floating-point types case
4521 if Vax_Float (Etype (N)) then
4522 Expand_Vax_Arith (N);
4524 end Expand_N_Op_Abs;
4526 ---------------------
4527 -- Expand_N_Op_Add --
4528 ---------------------
4530 procedure Expand_N_Op_Add (N : Node_Id) is
4531 Typ : constant Entity_Id := Etype (N);
4534 Binary_Op_Validity_Checks (N);
4536 -- N + 0 = 0 + N = N for integer types
4538 if Is_Integer_Type (Typ) then
4539 if Compile_Time_Known_Value (Right_Opnd (N))
4540 and then Expr_Value (Right_Opnd (N)) = Uint_0
4542 Rewrite (N, Left_Opnd (N));
4545 elsif Compile_Time_Known_Value (Left_Opnd (N))
4546 and then Expr_Value (Left_Opnd (N)) = Uint_0
4548 Rewrite (N, Right_Opnd (N));
4553 -- Arithmetic overflow checks for signed integer/fixed point types
4555 if Is_Signed_Integer_Type (Typ)
4556 or else Is_Fixed_Point_Type (Typ)
4558 Apply_Arithmetic_Overflow_Check (N);
4561 -- Vax floating-point types case
4563 elsif Vax_Float (Typ) then
4564 Expand_Vax_Arith (N);
4566 end Expand_N_Op_Add;
4568 ---------------------
4569 -- Expand_N_Op_And --
4570 ---------------------
4572 procedure Expand_N_Op_And (N : Node_Id) is
4573 Typ : constant Entity_Id := Etype (N);
4576 Binary_Op_Validity_Checks (N);
4578 if Is_Array_Type (Etype (N)) then
4579 Expand_Boolean_Operator (N);
4581 elsif Is_Boolean_Type (Etype (N)) then
4582 Adjust_Condition (Left_Opnd (N));
4583 Adjust_Condition (Right_Opnd (N));
4584 Set_Etype (N, Standard_Boolean);
4585 Adjust_Result_Type (N, Typ);
4587 end Expand_N_Op_And;
4589 ------------------------
4590 -- Expand_N_Op_Concat --
4591 ------------------------
4593 procedure Expand_N_Op_Concat (N : Node_Id) is
4595 -- List of operands to be concatenated
4598 -- Node which is to be replaced by the result of concatenating the nodes
4599 -- in the list Opnds.
4602 -- Ensure validity of both operands
4604 Binary_Op_Validity_Checks (N);
4606 -- If we are the left operand of a concatenation higher up the tree,
4607 -- then do nothing for now, since we want to deal with a series of
4608 -- concatenations as a unit.
4610 if Nkind (Parent (N)) = N_Op_Concat
4611 and then N = Left_Opnd (Parent (N))
4616 -- We get here with a concatenation whose left operand may be a
4617 -- concatenation itself with a consistent type. We need to process
4618 -- these concatenation operands from left to right, which means
4619 -- from the deepest node in the tree to the highest node.
4622 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
4623 Cnode := Left_Opnd (Cnode);
4626 -- Now Opnd is the deepest Opnd, and its parents are the concatenation
4627 -- nodes above, so now we process bottom up, doing the operations. We
4628 -- gather a string that is as long as possible up to five operands
4630 -- The outer loop runs more than once if more than one concatenation
4631 -- type is involved.
4634 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
4635 Set_Parent (Opnds, N);
4637 -- The inner loop gathers concatenation operands
4639 Inner : while Cnode /= N
4640 and then Base_Type (Etype (Cnode)) =
4641 Base_Type (Etype (Parent (Cnode)))
4643 Cnode := Parent (Cnode);
4644 Append (Right_Opnd (Cnode), Opnds);
4647 Expand_Concatenate (Cnode, Opnds);
4649 exit Outer when Cnode = N;
4650 Cnode := Parent (Cnode);
4652 end Expand_N_Op_Concat;
4654 ------------------------
4655 -- Expand_N_Op_Divide --
4656 ------------------------
4658 procedure Expand_N_Op_Divide (N : Node_Id) is
4659 Loc : constant Source_Ptr := Sloc (N);
4660 Lopnd : constant Node_Id := Left_Opnd (N);
4661 Ropnd : constant Node_Id := Right_Opnd (N);
4662 Ltyp : constant Entity_Id := Etype (Lopnd);
4663 Rtyp : constant Entity_Id := Etype (Ropnd);
4664 Typ : Entity_Id := Etype (N);
4665 Rknow : constant Boolean := Is_Integer_Type (Typ)
4667 Compile_Time_Known_Value (Ropnd);
4671 Binary_Op_Validity_Checks (N);
4674 Rval := Expr_Value (Ropnd);
4677 -- N / 1 = N for integer types
4679 if Rknow and then Rval = Uint_1 then
4684 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
4685 -- Is_Power_Of_2_For_Shift is set means that we know that our left
4686 -- operand is an unsigned integer, as required for this to work.
4688 if Nkind (Ropnd) = N_Op_Expon
4689 and then Is_Power_Of_2_For_Shift (Ropnd)
4691 -- We cannot do this transformation in configurable run time mode if we
4692 -- have 64-bit -- integers and long shifts are not available.
4696 or else Support_Long_Shifts_On_Target)
4699 Make_Op_Shift_Right (Loc,
4702 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
4703 Analyze_And_Resolve (N, Typ);
4707 -- Do required fixup of universal fixed operation
4709 if Typ = Universal_Fixed then
4710 Fixup_Universal_Fixed_Operation (N);
4714 -- Divisions with fixed-point results
4716 if Is_Fixed_Point_Type (Typ) then
4718 -- No special processing if Treat_Fixed_As_Integer is set, since
4719 -- from a semantic point of view such operations are simply integer
4720 -- operations and will be treated that way.
4722 if not Treat_Fixed_As_Integer (N) then
4723 if Is_Integer_Type (Rtyp) then
4724 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
4726 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
4730 -- Other cases of division of fixed-point operands. Again we exclude the
4731 -- case where Treat_Fixed_As_Integer is set.
4733 elsif (Is_Fixed_Point_Type (Ltyp) or else
4734 Is_Fixed_Point_Type (Rtyp))
4735 and then not Treat_Fixed_As_Integer (N)
4737 if Is_Integer_Type (Typ) then
4738 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
4740 pragma Assert (Is_Floating_Point_Type (Typ));
4741 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
4744 -- Mixed-mode operations can appear in a non-static universal context,
4745 -- in which case the integer argument must be converted explicitly.
4747 elsif Typ = Universal_Real
4748 and then Is_Integer_Type (Rtyp)
4751 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
4753 Analyze_And_Resolve (Ropnd, Universal_Real);
4755 elsif Typ = Universal_Real
4756 and then Is_Integer_Type (Ltyp)
4759 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
4761 Analyze_And_Resolve (Lopnd, Universal_Real);
4763 -- Non-fixed point cases, do integer zero divide and overflow checks
4765 elsif Is_Integer_Type (Typ) then
4766 Apply_Divide_Check (N);
4768 -- Check for 64-bit division available, or long shifts if the divisor
4769 -- is a small power of 2 (since such divides will be converted into
4772 if Esize (Ltyp) > 32
4773 and then not Support_64_Bit_Divides_On_Target
4776 or else not Support_Long_Shifts_On_Target
4777 or else (Rval /= Uint_2 and then
4778 Rval /= Uint_4 and then
4779 Rval /= Uint_8 and then
4780 Rval /= Uint_16 and then
4781 Rval /= Uint_32 and then
4784 Error_Msg_CRT ("64-bit division", N);
4787 -- Deal with Vax_Float
4789 elsif Vax_Float (Typ) then
4790 Expand_Vax_Arith (N);
4793 end Expand_N_Op_Divide;
4795 --------------------
4796 -- Expand_N_Op_Eq --
4797 --------------------
4799 procedure Expand_N_Op_Eq (N : Node_Id) is
4800 Loc : constant Source_Ptr := Sloc (N);
4801 Typ : constant Entity_Id := Etype (N);
4802 Lhs : constant Node_Id := Left_Opnd (N);
4803 Rhs : constant Node_Id := Right_Opnd (N);
4804 Bodies : constant List_Id := New_List;
4805 A_Typ : constant Entity_Id := Etype (Lhs);
4807 Typl : Entity_Id := A_Typ;
4808 Op_Name : Entity_Id;
4811 procedure Build_Equality_Call (Eq : Entity_Id);
4812 -- If a constructed equality exists for the type or for its parent,
4813 -- build and analyze call, adding conversions if the operation is
4816 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
4817 -- Determines whether a type has a subcomponent of an unconstrained
4818 -- Unchecked_Union subtype. Typ is a record type.
4820 -------------------------
4821 -- Build_Equality_Call --
4822 -------------------------
4824 procedure Build_Equality_Call (Eq : Entity_Id) is
4825 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
4826 L_Exp : Node_Id := Relocate_Node (Lhs);
4827 R_Exp : Node_Id := Relocate_Node (Rhs);
4830 if Base_Type (Op_Type) /= Base_Type (A_Typ)
4831 and then not Is_Class_Wide_Type (A_Typ)
4833 L_Exp := OK_Convert_To (Op_Type, L_Exp);
4834 R_Exp := OK_Convert_To (Op_Type, R_Exp);
4837 -- If we have an Unchecked_Union, we need to add the inferred
4838 -- discriminant values as actuals in the function call. At this
4839 -- point, the expansion has determined that both operands have
4840 -- inferable discriminants.
4842 if Is_Unchecked_Union (Op_Type) then
4844 Lhs_Type : constant Node_Id := Etype (L_Exp);
4845 Rhs_Type : constant Node_Id := Etype (R_Exp);
4846 Lhs_Discr_Val : Node_Id;
4847 Rhs_Discr_Val : Node_Id;
4850 -- Per-object constrained selected components require special
4851 -- attention. If the enclosing scope of the component is an
4852 -- Unchecked_Union, we cannot reference its discriminants
4853 -- directly. This is why we use the two extra parameters of
4854 -- the equality function of the enclosing Unchecked_Union.
4856 -- type UU_Type (Discr : Integer := 0) is
4859 -- pragma Unchecked_Union (UU_Type);
4861 -- 1. Unchecked_Union enclosing record:
4863 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
4865 -- Comp : UU_Type (Discr);
4867 -- end Enclosing_UU_Type;
4868 -- pragma Unchecked_Union (Enclosing_UU_Type);
4870 -- Obj1 : Enclosing_UU_Type;
4871 -- Obj2 : Enclosing_UU_Type (1);
4873 -- [. . .] Obj1 = Obj2 [. . .]
4877 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
4879 -- A and B are the formal parameters of the equality function
4880 -- of Enclosing_UU_Type. The function always has two extra
4881 -- formals to capture the inferred discriminant values.
4883 -- 2. Non-Unchecked_Union enclosing record:
4886 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
4889 -- Comp : UU_Type (Discr);
4891 -- end Enclosing_Non_UU_Type;
4893 -- Obj1 : Enclosing_Non_UU_Type;
4894 -- Obj2 : Enclosing_Non_UU_Type (1);
4896 -- ... Obj1 = Obj2 ...
4900 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
4901 -- obj1.discr, obj2.discr)) then
4903 -- In this case we can directly reference the discriminants of
4904 -- the enclosing record.
4908 if Nkind (Lhs) = N_Selected_Component
4909 and then Has_Per_Object_Constraint
4910 (Entity (Selector_Name (Lhs)))
4912 -- Enclosing record is an Unchecked_Union, use formal A
4914 if Is_Unchecked_Union (Scope
4915 (Entity (Selector_Name (Lhs))))
4918 Make_Identifier (Loc,
4921 -- Enclosing record is of a non-Unchecked_Union type, it is
4922 -- possible to reference the discriminant.
4926 Make_Selected_Component (Loc,
4927 Prefix => Prefix (Lhs),
4930 (Get_Discriminant_Value
4931 (First_Discriminant (Lhs_Type),
4933 Stored_Constraint (Lhs_Type))));
4936 -- Comment needed here ???
4939 -- Infer the discriminant value
4943 (Get_Discriminant_Value
4944 (First_Discriminant (Lhs_Type),
4946 Stored_Constraint (Lhs_Type)));
4951 if Nkind (Rhs) = N_Selected_Component
4952 and then Has_Per_Object_Constraint
4953 (Entity (Selector_Name (Rhs)))
4955 if Is_Unchecked_Union
4956 (Scope (Entity (Selector_Name (Rhs))))
4959 Make_Identifier (Loc,
4964 Make_Selected_Component (Loc,
4965 Prefix => Prefix (Rhs),
4967 New_Copy (Get_Discriminant_Value (
4968 First_Discriminant (Rhs_Type),
4970 Stored_Constraint (Rhs_Type))));
4975 New_Copy (Get_Discriminant_Value (
4976 First_Discriminant (Rhs_Type),
4978 Stored_Constraint (Rhs_Type)));
4983 Make_Function_Call (Loc,
4984 Name => New_Reference_To (Eq, Loc),
4985 Parameter_Associations => New_List (
4992 -- Normal case, not an unchecked union
4996 Make_Function_Call (Loc,
4997 Name => New_Reference_To (Eq, Loc),
4998 Parameter_Associations => New_List (L_Exp, R_Exp)));
5001 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5002 end Build_Equality_Call;
5004 ------------------------------------
5005 -- Has_Unconstrained_UU_Component --
5006 ------------------------------------
5008 function Has_Unconstrained_UU_Component
5009 (Typ : Node_Id) return Boolean
5011 Tdef : constant Node_Id :=
5012 Type_Definition (Declaration_Node (Base_Type (Typ)));
5016 function Component_Is_Unconstrained_UU
5017 (Comp : Node_Id) return Boolean;
5018 -- Determines whether the subtype of the component is an
5019 -- unconstrained Unchecked_Union.
5021 function Variant_Is_Unconstrained_UU
5022 (Variant : Node_Id) return Boolean;
5023 -- Determines whether a component of the variant has an unconstrained
5024 -- Unchecked_Union subtype.
5026 -----------------------------------
5027 -- Component_Is_Unconstrained_UU --
5028 -----------------------------------
5030 function Component_Is_Unconstrained_UU
5031 (Comp : Node_Id) return Boolean
5034 if Nkind (Comp) /= N_Component_Declaration then
5039 Sindic : constant Node_Id :=
5040 Subtype_Indication (Component_Definition (Comp));
5043 -- Unconstrained nominal type. In the case of a constraint
5044 -- present, the node kind would have been N_Subtype_Indication.
5046 if Nkind (Sindic) = N_Identifier then
5047 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
5052 end Component_Is_Unconstrained_UU;
5054 ---------------------------------
5055 -- Variant_Is_Unconstrained_UU --
5056 ---------------------------------
5058 function Variant_Is_Unconstrained_UU
5059 (Variant : Node_Id) return Boolean
5061 Clist : constant Node_Id := Component_List (Variant);
5064 if Is_Empty_List (Component_Items (Clist)) then
5068 -- We only need to test one component
5071 Comp : Node_Id := First (Component_Items (Clist));
5074 while Present (Comp) loop
5075 if Component_Is_Unconstrained_UU (Comp) then
5083 -- None of the components withing the variant were of
5084 -- unconstrained Unchecked_Union type.
5087 end Variant_Is_Unconstrained_UU;
5089 -- Start of processing for Has_Unconstrained_UU_Component
5092 if Null_Present (Tdef) then
5096 Clist := Component_List (Tdef);
5097 Vpart := Variant_Part (Clist);
5099 -- Inspect available components
5101 if Present (Component_Items (Clist)) then
5103 Comp : Node_Id := First (Component_Items (Clist));
5106 while Present (Comp) loop
5108 -- One component is sufficient
5110 if Component_Is_Unconstrained_UU (Comp) then
5119 -- Inspect available components withing variants
5121 if Present (Vpart) then
5123 Variant : Node_Id := First (Variants (Vpart));
5126 while Present (Variant) loop
5128 -- One component within a variant is sufficient
5130 if Variant_Is_Unconstrained_UU (Variant) then
5139 -- Neither the available components, nor the components inside the
5140 -- variant parts were of an unconstrained Unchecked_Union subtype.
5143 end Has_Unconstrained_UU_Component;
5145 -- Start of processing for Expand_N_Op_Eq
5148 Binary_Op_Validity_Checks (N);
5150 if Ekind (Typl) = E_Private_Type then
5151 Typl := Underlying_Type (Typl);
5152 elsif Ekind (Typl) = E_Private_Subtype then
5153 Typl := Underlying_Type (Base_Type (Typl));
5158 -- It may happen in error situations that the underlying type is not
5159 -- set. The error will be detected later, here we just defend the
5166 Typl := Base_Type (Typl);
5168 -- Boolean types (requiring handling of non-standard case)
5170 if Is_Boolean_Type (Typl) then
5171 Adjust_Condition (Left_Opnd (N));
5172 Adjust_Condition (Right_Opnd (N));
5173 Set_Etype (N, Standard_Boolean);
5174 Adjust_Result_Type (N, Typ);
5178 elsif Is_Array_Type (Typl) then
5180 -- If we are doing full validity checking, and it is possible for the
5181 -- array elements to be invalid then expand out array comparisons to
5182 -- make sure that we check the array elements.
5184 if Validity_Check_Operands
5185 and then not Is_Known_Valid (Component_Type (Typl))
5188 Save_Force_Validity_Checks : constant Boolean :=
5189 Force_Validity_Checks;
5191 Force_Validity_Checks := True;
5193 Expand_Array_Equality
5195 Relocate_Node (Lhs),
5196 Relocate_Node (Rhs),
5199 Insert_Actions (N, Bodies);
5200 Analyze_And_Resolve (N, Standard_Boolean);
5201 Force_Validity_Checks := Save_Force_Validity_Checks;
5204 -- Packed case where both operands are known aligned
5206 elsif Is_Bit_Packed_Array (Typl)
5207 and then not Is_Possibly_Unaligned_Object (Lhs)
5208 and then not Is_Possibly_Unaligned_Object (Rhs)
5210 Expand_Packed_Eq (N);
5212 -- Where the component type is elementary we can use a block bit
5213 -- comparison (if supported on the target) exception in the case
5214 -- of floating-point (negative zero issues require element by
5215 -- element comparison), and atomic types (where we must be sure
5216 -- to load elements independently) and possibly unaligned arrays.
5218 elsif Is_Elementary_Type (Component_Type (Typl))
5219 and then not Is_Floating_Point_Type (Component_Type (Typl))
5220 and then not Is_Atomic (Component_Type (Typl))
5221 and then not Is_Possibly_Unaligned_Object (Lhs)
5222 and then not Is_Possibly_Unaligned_Object (Rhs)
5223 and then Support_Composite_Compare_On_Target
5227 -- For composite and floating-point cases, expand equality loop to
5228 -- make sure of using proper comparisons for tagged types, and
5229 -- correctly handling the floating-point case.
5233 Expand_Array_Equality
5235 Relocate_Node (Lhs),
5236 Relocate_Node (Rhs),
5239 Insert_Actions (N, Bodies, Suppress => All_Checks);
5240 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5245 elsif Is_Record_Type (Typl) then
5247 -- For tagged types, use the primitive "="
5249 if Is_Tagged_Type (Typl) then
5251 -- No need to do anything else compiling under restriction
5252 -- No_Dispatching_Calls. During the semantic analysis we
5253 -- already notified such violation.
5255 if Restriction_Active (No_Dispatching_Calls) then
5259 -- If this is derived from an untagged private type completed with
5260 -- a tagged type, it does not have a full view, so we use the
5261 -- primitive operations of the private type. This check should no
5262 -- longer be necessary when these types get their full views???
5264 if Is_Private_Type (A_Typ)
5265 and then not Is_Tagged_Type (A_Typ)
5266 and then Is_Derived_Type (A_Typ)
5267 and then No (Full_View (A_Typ))
5269 -- Search for equality operation, checking that the operands
5270 -- have the same type. Note that we must find a matching entry,
5271 -- or something is very wrong!
5273 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
5275 while Present (Prim) loop
5276 exit when Chars (Node (Prim)) = Name_Op_Eq
5277 and then Etype (First_Formal (Node (Prim))) =
5278 Etype (Next_Formal (First_Formal (Node (Prim))))
5280 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
5285 pragma Assert (Present (Prim));
5286 Op_Name := Node (Prim);
5288 -- Find the type's predefined equality or an overriding
5289 -- user- defined equality. The reason for not simply calling
5290 -- Find_Prim_Op here is that there may be a user-defined
5291 -- overloaded equality op that precedes the equality that we want,
5292 -- so we have to explicitly search (e.g., there could be an
5293 -- equality with two different parameter types).
5296 if Is_Class_Wide_Type (Typl) then
5297 Typl := Root_Type (Typl);
5300 Prim := First_Elmt (Primitive_Operations (Typl));
5301 while Present (Prim) loop
5302 exit when Chars (Node (Prim)) = Name_Op_Eq
5303 and then Etype (First_Formal (Node (Prim))) =
5304 Etype (Next_Formal (First_Formal (Node (Prim))))
5306 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
5311 pragma Assert (Present (Prim));
5312 Op_Name := Node (Prim);
5315 Build_Equality_Call (Op_Name);
5317 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
5318 -- predefined equality operator for a type which has a subcomponent
5319 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
5321 elsif Has_Unconstrained_UU_Component (Typl) then
5323 Make_Raise_Program_Error (Loc,
5324 Reason => PE_Unchecked_Union_Restriction));
5326 -- Prevent Gigi from generating incorrect code by rewriting the
5327 -- equality as a standard False.
5330 New_Occurrence_Of (Standard_False, Loc));
5332 elsif Is_Unchecked_Union (Typl) then
5334 -- If we can infer the discriminants of the operands, we make a
5335 -- call to the TSS equality function.
5337 if Has_Inferable_Discriminants (Lhs)
5339 Has_Inferable_Discriminants (Rhs)
5342 (TSS (Root_Type (Typl), TSS_Composite_Equality));
5345 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
5346 -- the predefined equality operator for an Unchecked_Union type
5347 -- if either of the operands lack inferable discriminants.
5350 Make_Raise_Program_Error (Loc,
5351 Reason => PE_Unchecked_Union_Restriction));
5353 -- Prevent Gigi from generating incorrect code by rewriting
5354 -- the equality as a standard False.
5357 New_Occurrence_Of (Standard_False, Loc));
5361 -- If a type support function is present (for complex cases), use it
5363 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
5365 (TSS (Root_Type (Typl), TSS_Composite_Equality));
5367 -- Otherwise expand the component by component equality. Note that
5368 -- we never use block-bit comparisons for records, because of the
5369 -- problems with gaps. The backend will often be able to recombine
5370 -- the separate comparisons that we generate here.
5373 Remove_Side_Effects (Lhs);
5374 Remove_Side_Effects (Rhs);
5376 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
5378 Insert_Actions (N, Bodies, Suppress => All_Checks);
5379 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5383 -- Test if result is known at compile time
5385 Rewrite_Comparison (N);
5387 -- If we still have comparison for Vax_Float, process it
5389 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
5390 Expand_Vax_Comparison (N);
5395 -----------------------
5396 -- Expand_N_Op_Expon --
5397 -----------------------
5399 procedure Expand_N_Op_Expon (N : Node_Id) is
5400 Loc : constant Source_Ptr := Sloc (N);
5401 Typ : constant Entity_Id := Etype (N);
5402 Rtyp : constant Entity_Id := Root_Type (Typ);
5403 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
5404 Bastyp : constant Node_Id := Etype (Base);
5405 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
5406 Exptyp : constant Entity_Id := Etype (Exp);
5407 Ovflo : constant Boolean := Do_Overflow_Check (N);
5416 Binary_Op_Validity_Checks (N);
5418 -- If either operand is of a private type, then we have the use of an
5419 -- intrinsic operator, and we get rid of the privateness, by using root
5420 -- types of underlying types for the actual operation. Otherwise the
5421 -- private types will cause trouble if we expand multiplications or
5422 -- shifts etc. We also do this transformation if the result type is
5423 -- different from the base type.
5425 if Is_Private_Type (Etype (Base))
5427 Is_Private_Type (Typ)
5429 Is_Private_Type (Exptyp)
5431 Rtyp /= Root_Type (Bastyp)
5434 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
5435 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
5439 Unchecked_Convert_To (Typ,
5441 Left_Opnd => Unchecked_Convert_To (Bt, Base),
5442 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
5443 Analyze_And_Resolve (N, Typ);
5448 -- Test for case of known right argument
5450 if Compile_Time_Known_Value (Exp) then
5451 Expv := Expr_Value (Exp);
5453 -- We only fold small non-negative exponents. You might think we
5454 -- could fold small negative exponents for the real case, but we
5455 -- can't because we are required to raise Constraint_Error for
5456 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
5457 -- See ACVC test C4A012B.
5459 if Expv >= 0 and then Expv <= 4 then
5461 -- X ** 0 = 1 (or 1.0)
5465 -- Call Remove_Side_Effects to ensure that any side effects
5466 -- in the ignored left operand (in particular function calls
5467 -- to user defined functions) are properly executed.
5469 Remove_Side_Effects (Base);
5471 if Ekind (Typ) in Integer_Kind then
5472 Xnode := Make_Integer_Literal (Loc, Intval => 1);
5474 Xnode := Make_Real_Literal (Loc, Ureal_1);
5486 Make_Op_Multiply (Loc,
5487 Left_Opnd => Duplicate_Subexpr (Base),
5488 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
5490 -- X ** 3 = X * X * X
5494 Make_Op_Multiply (Loc,
5496 Make_Op_Multiply (Loc,
5497 Left_Opnd => Duplicate_Subexpr (Base),
5498 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
5499 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
5502 -- En : constant base'type := base * base;
5508 Make_Defining_Identifier (Loc, New_Internal_Name ('E'));
5510 Insert_Actions (N, New_List (
5511 Make_Object_Declaration (Loc,
5512 Defining_Identifier => Temp,
5513 Constant_Present => True,
5514 Object_Definition => New_Reference_To (Typ, Loc),
5516 Make_Op_Multiply (Loc,
5517 Left_Opnd => Duplicate_Subexpr (Base),
5518 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
5521 Make_Op_Multiply (Loc,
5522 Left_Opnd => New_Reference_To (Temp, Loc),
5523 Right_Opnd => New_Reference_To (Temp, Loc));
5527 Analyze_And_Resolve (N, Typ);
5532 -- Case of (2 ** expression) appearing as an argument of an integer
5533 -- multiplication, or as the right argument of a division of a non-
5534 -- negative integer. In such cases we leave the node untouched, setting
5535 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
5536 -- of the higher level node converts it into a shift.
5538 -- Note: this transformation is not applicable for a modular type with
5539 -- a non-binary modulus in the multiplication case, since we get a wrong
5540 -- result if the shift causes an overflow before the modular reduction.
5542 if Nkind (Base) = N_Integer_Literal
5543 and then Intval (Base) = 2
5544 and then Is_Integer_Type (Root_Type (Exptyp))
5545 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
5546 and then Is_Unsigned_Type (Exptyp)
5548 and then Nkind (Parent (N)) in N_Binary_Op
5551 P : constant Node_Id := Parent (N);
5552 L : constant Node_Id := Left_Opnd (P);
5553 R : constant Node_Id := Right_Opnd (P);
5556 if (Nkind (P) = N_Op_Multiply
5557 and then not Non_Binary_Modulus (Typ)
5559 ((Is_Integer_Type (Etype (L)) and then R = N)
5561 (Is_Integer_Type (Etype (R)) and then L = N))
5562 and then not Do_Overflow_Check (P))
5565 (Nkind (P) = N_Op_Divide
5566 and then Is_Integer_Type (Etype (L))
5567 and then Is_Unsigned_Type (Etype (L))
5569 and then not Do_Overflow_Check (P))
5571 Set_Is_Power_Of_2_For_Shift (N);
5577 -- Fall through if exponentiation must be done using a runtime routine
5579 -- First deal with modular case
5581 if Is_Modular_Integer_Type (Rtyp) then
5583 -- Non-binary case, we call the special exponentiation routine for
5584 -- the non-binary case, converting the argument to Long_Long_Integer
5585 -- and passing the modulus value. Then the result is converted back
5586 -- to the base type.
5588 if Non_Binary_Modulus (Rtyp) then
5591 Make_Function_Call (Loc,
5592 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
5593 Parameter_Associations => New_List (
5594 Convert_To (Standard_Integer, Base),
5595 Make_Integer_Literal (Loc, Modulus (Rtyp)),
5598 -- Binary case, in this case, we call one of two routines, either the
5599 -- unsigned integer case, or the unsigned long long integer case,
5600 -- with a final "and" operation to do the required mod.
5603 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
5604 Ent := RTE (RE_Exp_Unsigned);
5606 Ent := RTE (RE_Exp_Long_Long_Unsigned);
5613 Make_Function_Call (Loc,
5614 Name => New_Reference_To (Ent, Loc),
5615 Parameter_Associations => New_List (
5616 Convert_To (Etype (First_Formal (Ent)), Base),
5619 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
5623 -- Common exit point for modular type case
5625 Analyze_And_Resolve (N, Typ);
5628 -- Signed integer cases, done using either Integer or Long_Long_Integer.
5629 -- It is not worth having routines for Short_[Short_]Integer, since for
5630 -- most machines it would not help, and it would generate more code that
5631 -- might need certification when a certified run time is required.
5633 -- In the integer cases, we have two routines, one for when overflow
5634 -- checks are required, and one when they are not required, since there
5635 -- is a real gain in omitting checks on many machines.
5637 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
5638 or else (Rtyp = Base_Type (Standard_Long_Integer)
5640 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
5641 or else (Rtyp = Universal_Integer)
5643 Etyp := Standard_Long_Long_Integer;
5646 Rent := RE_Exp_Long_Long_Integer;
5648 Rent := RE_Exn_Long_Long_Integer;
5651 elsif Is_Signed_Integer_Type (Rtyp) then
5652 Etyp := Standard_Integer;
5655 Rent := RE_Exp_Integer;
5657 Rent := RE_Exn_Integer;
5660 -- Floating-point cases, always done using Long_Long_Float. We do not
5661 -- need separate routines for the overflow case here, since in the case
5662 -- of floating-point, we generate infinities anyway as a rule (either
5663 -- that or we automatically trap overflow), and if there is an infinity
5664 -- generated and a range check is required, the check will fail anyway.
5667 pragma Assert (Is_Floating_Point_Type (Rtyp));
5668 Etyp := Standard_Long_Long_Float;
5669 Rent := RE_Exn_Long_Long_Float;
5672 -- Common processing for integer cases and floating-point cases.
5673 -- If we are in the right type, we can call runtime routine directly
5676 and then Rtyp /= Universal_Integer
5677 and then Rtyp /= Universal_Real
5680 Make_Function_Call (Loc,
5681 Name => New_Reference_To (RTE (Rent), Loc),
5682 Parameter_Associations => New_List (Base, Exp)));
5684 -- Otherwise we have to introduce conversions (conversions are also
5685 -- required in the universal cases, since the runtime routine is
5686 -- typed using one of the standard types.
5691 Make_Function_Call (Loc,
5692 Name => New_Reference_To (RTE (Rent), Loc),
5693 Parameter_Associations => New_List (
5694 Convert_To (Etyp, Base),
5698 Analyze_And_Resolve (N, Typ);
5702 when RE_Not_Available =>
5704 end Expand_N_Op_Expon;
5706 --------------------
5707 -- Expand_N_Op_Ge --
5708 --------------------
5710 procedure Expand_N_Op_Ge (N : Node_Id) is
5711 Typ : constant Entity_Id := Etype (N);
5712 Op1 : constant Node_Id := Left_Opnd (N);
5713 Op2 : constant Node_Id := Right_Opnd (N);
5714 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
5717 Binary_Op_Validity_Checks (N);
5719 if Is_Array_Type (Typ1) then
5720 Expand_Array_Comparison (N);
5724 if Is_Boolean_Type (Typ1) then
5725 Adjust_Condition (Op1);
5726 Adjust_Condition (Op2);
5727 Set_Etype (N, Standard_Boolean);
5728 Adjust_Result_Type (N, Typ);
5731 Rewrite_Comparison (N);
5733 -- If we still have comparison, and Vax_Float type, process it
5735 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
5736 Expand_Vax_Comparison (N);
5741 --------------------
5742 -- Expand_N_Op_Gt --
5743 --------------------
5745 procedure Expand_N_Op_Gt (N : Node_Id) is
5746 Typ : constant Entity_Id := Etype (N);
5747 Op1 : constant Node_Id := Left_Opnd (N);
5748 Op2 : constant Node_Id := Right_Opnd (N);
5749 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
5752 Binary_Op_Validity_Checks (N);
5754 if Is_Array_Type (Typ1) then
5755 Expand_Array_Comparison (N);
5759 if Is_Boolean_Type (Typ1) then
5760 Adjust_Condition (Op1);
5761 Adjust_Condition (Op2);
5762 Set_Etype (N, Standard_Boolean);
5763 Adjust_Result_Type (N, Typ);
5766 Rewrite_Comparison (N);
5768 -- If we still have comparison, and Vax_Float type, process it
5770 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
5771 Expand_Vax_Comparison (N);
5776 --------------------
5777 -- Expand_N_Op_Le --
5778 --------------------
5780 procedure Expand_N_Op_Le (N : Node_Id) is
5781 Typ : constant Entity_Id := Etype (N);
5782 Op1 : constant Node_Id := Left_Opnd (N);
5783 Op2 : constant Node_Id := Right_Opnd (N);
5784 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
5787 Binary_Op_Validity_Checks (N);
5789 if Is_Array_Type (Typ1) then
5790 Expand_Array_Comparison (N);
5794 if Is_Boolean_Type (Typ1) then
5795 Adjust_Condition (Op1);
5796 Adjust_Condition (Op2);
5797 Set_Etype (N, Standard_Boolean);
5798 Adjust_Result_Type (N, Typ);
5801 Rewrite_Comparison (N);
5803 -- If we still have comparison, and Vax_Float type, process it
5805 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
5806 Expand_Vax_Comparison (N);
5811 --------------------
5812 -- Expand_N_Op_Lt --
5813 --------------------
5815 procedure Expand_N_Op_Lt (N : Node_Id) is
5816 Typ : constant Entity_Id := Etype (N);
5817 Op1 : constant Node_Id := Left_Opnd (N);
5818 Op2 : constant Node_Id := Right_Opnd (N);
5819 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
5822 Binary_Op_Validity_Checks (N);
5824 if Is_Array_Type (Typ1) then
5825 Expand_Array_Comparison (N);
5829 if Is_Boolean_Type (Typ1) then
5830 Adjust_Condition (Op1);
5831 Adjust_Condition (Op2);
5832 Set_Etype (N, Standard_Boolean);
5833 Adjust_Result_Type (N, Typ);
5836 Rewrite_Comparison (N);
5838 -- If we still have comparison, and Vax_Float type, process it
5840 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
5841 Expand_Vax_Comparison (N);
5846 -----------------------
5847 -- Expand_N_Op_Minus --
5848 -----------------------
5850 procedure Expand_N_Op_Minus (N : Node_Id) is
5851 Loc : constant Source_Ptr := Sloc (N);
5852 Typ : constant Entity_Id := Etype (N);
5855 Unary_Op_Validity_Checks (N);
5857 if not Backend_Overflow_Checks_On_Target
5858 and then Is_Signed_Integer_Type (Etype (N))
5859 and then Do_Overflow_Check (N)
5861 -- Software overflow checking expands -expr into (0 - expr)
5864 Make_Op_Subtract (Loc,
5865 Left_Opnd => Make_Integer_Literal (Loc, 0),
5866 Right_Opnd => Right_Opnd (N)));
5868 Analyze_And_Resolve (N, Typ);
5870 -- Vax floating-point types case
5872 elsif Vax_Float (Etype (N)) then
5873 Expand_Vax_Arith (N);
5875 end Expand_N_Op_Minus;
5877 ---------------------
5878 -- Expand_N_Op_Mod --
5879 ---------------------
5881 procedure Expand_N_Op_Mod (N : Node_Id) is
5882 Loc : constant Source_Ptr := Sloc (N);
5883 Typ : constant Entity_Id := Etype (N);
5884 Left : constant Node_Id := Left_Opnd (N);
5885 Right : constant Node_Id := Right_Opnd (N);
5886 DOC : constant Boolean := Do_Overflow_Check (N);
5887 DDC : constant Boolean := Do_Division_Check (N);
5897 pragma Warnings (Off, Lhi);
5900 Binary_Op_Validity_Checks (N);
5902 Determine_Range (Right, ROK, Rlo, Rhi);
5903 Determine_Range (Left, LOK, Llo, Lhi);
5905 -- Convert mod to rem if operands are known non-negative. We do this
5906 -- since it is quite likely that this will improve the quality of code,
5907 -- (the operation now corresponds to the hardware remainder), and it
5908 -- does not seem likely that it could be harmful.
5910 if LOK and then Llo >= 0
5912 ROK and then Rlo >= 0
5915 Make_Op_Rem (Sloc (N),
5916 Left_Opnd => Left_Opnd (N),
5917 Right_Opnd => Right_Opnd (N)));
5919 -- Instead of reanalyzing the node we do the analysis manually. This
5920 -- avoids anomalies when the replacement is done in an instance and
5921 -- is epsilon more efficient.
5923 Set_Entity (N, Standard_Entity (S_Op_Rem));
5925 Set_Do_Overflow_Check (N, DOC);
5926 Set_Do_Division_Check (N, DDC);
5927 Expand_N_Op_Rem (N);
5930 -- Otherwise, normal mod processing
5933 if Is_Integer_Type (Etype (N)) then
5934 Apply_Divide_Check (N);
5937 -- Apply optimization x mod 1 = 0. We don't really need that with
5938 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
5939 -- certainly harmless.
5941 if Is_Integer_Type (Etype (N))
5942 and then Compile_Time_Known_Value (Right)
5943 and then Expr_Value (Right) = Uint_1
5945 -- Call Remove_Side_Effects to ensure that any side effects in
5946 -- the ignored left operand (in particular function calls to
5947 -- user defined functions) are properly executed.
5949 Remove_Side_Effects (Left);
5951 Rewrite (N, Make_Integer_Literal (Loc, 0));
5952 Analyze_And_Resolve (N, Typ);
5956 -- Deal with annoying case of largest negative number remainder
5957 -- minus one. Gigi does not handle this case correctly, because
5958 -- it generates a divide instruction which may trap in this case.
5960 -- In fact the check is quite easy, if the right operand is -1, then
5961 -- the mod value is always 0, and we can just ignore the left operand
5962 -- completely in this case.
5964 -- The operand type may be private (e.g. in the expansion of an
5965 -- intrinsic operation) so we must use the underlying type to get the
5966 -- bounds, and convert the literals explicitly.
5970 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
5972 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
5974 ((not LOK) or else (Llo = LLB))
5977 Make_Conditional_Expression (Loc,
5978 Expressions => New_List (
5980 Left_Opnd => Duplicate_Subexpr (Right),
5982 Unchecked_Convert_To (Typ,
5983 Make_Integer_Literal (Loc, -1))),
5984 Unchecked_Convert_To (Typ,
5985 Make_Integer_Literal (Loc, Uint_0)),
5986 Relocate_Node (N))));
5988 Set_Analyzed (Next (Next (First (Expressions (N)))));
5989 Analyze_And_Resolve (N, Typ);
5992 end Expand_N_Op_Mod;
5994 --------------------------
5995 -- Expand_N_Op_Multiply --
5996 --------------------------
5998 procedure Expand_N_Op_Multiply (N : Node_Id) is
5999 Loc : constant Source_Ptr := Sloc (N);
6000 Lop : constant Node_Id := Left_Opnd (N);
6001 Rop : constant Node_Id := Right_Opnd (N);
6003 Lp2 : constant Boolean :=
6004 Nkind (Lop) = N_Op_Expon
6005 and then Is_Power_Of_2_For_Shift (Lop);
6007 Rp2 : constant Boolean :=
6008 Nkind (Rop) = N_Op_Expon
6009 and then Is_Power_Of_2_For_Shift (Rop);
6011 Ltyp : constant Entity_Id := Etype (Lop);
6012 Rtyp : constant Entity_Id := Etype (Rop);
6013 Typ : Entity_Id := Etype (N);
6016 Binary_Op_Validity_Checks (N);
6018 -- Special optimizations for integer types
6020 if Is_Integer_Type (Typ) then
6022 -- N * 0 = 0 for integer types
6024 if Compile_Time_Known_Value (Rop)
6025 and then Expr_Value (Rop) = Uint_0
6027 -- Call Remove_Side_Effects to ensure that any side effects in
6028 -- the ignored left operand (in particular function calls to
6029 -- user defined functions) are properly executed.
6031 Remove_Side_Effects (Lop);
6033 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6034 Analyze_And_Resolve (N, Typ);
6038 -- Similar handling for 0 * N = 0
6040 if Compile_Time_Known_Value (Lop)
6041 and then Expr_Value (Lop) = Uint_0
6043 Remove_Side_Effects (Rop);
6044 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6045 Analyze_And_Resolve (N, Typ);
6049 -- N * 1 = 1 * N = N for integer types
6051 -- This optimisation is not done if we are going to
6052 -- rewrite the product 1 * 2 ** N to a shift.
6054 if Compile_Time_Known_Value (Rop)
6055 and then Expr_Value (Rop) = Uint_1
6061 elsif Compile_Time_Known_Value (Lop)
6062 and then Expr_Value (Lop) = Uint_1
6070 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
6071 -- Is_Power_Of_2_For_Shift is set means that we know that our left
6072 -- operand is an integer, as required for this to work.
6077 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
6081 Left_Opnd => Make_Integer_Literal (Loc, 2),
6084 Left_Opnd => Right_Opnd (Lop),
6085 Right_Opnd => Right_Opnd (Rop))));
6086 Analyze_And_Resolve (N, Typ);
6091 Make_Op_Shift_Left (Loc,
6094 Convert_To (Standard_Natural, Right_Opnd (Rop))));
6095 Analyze_And_Resolve (N, Typ);
6099 -- Same processing for the operands the other way round
6103 Make_Op_Shift_Left (Loc,
6106 Convert_To (Standard_Natural, Right_Opnd (Lop))));
6107 Analyze_And_Resolve (N, Typ);
6111 -- Do required fixup of universal fixed operation
6113 if Typ = Universal_Fixed then
6114 Fixup_Universal_Fixed_Operation (N);
6118 -- Multiplications with fixed-point results
6120 if Is_Fixed_Point_Type (Typ) then
6122 -- No special processing if Treat_Fixed_As_Integer is set, since from
6123 -- a semantic point of view such operations are simply integer
6124 -- operations and will be treated that way.
6126 if not Treat_Fixed_As_Integer (N) then
6128 -- Case of fixed * integer => fixed
6130 if Is_Integer_Type (Rtyp) then
6131 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
6133 -- Case of integer * fixed => fixed
6135 elsif Is_Integer_Type (Ltyp) then
6136 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
6138 -- Case of fixed * fixed => fixed
6141 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
6145 -- Other cases of multiplication of fixed-point operands. Again we
6146 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
6148 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
6149 and then not Treat_Fixed_As_Integer (N)
6151 if Is_Integer_Type (Typ) then
6152 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
6154 pragma Assert (Is_Floating_Point_Type (Typ));
6155 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
6158 -- Mixed-mode operations can appear in a non-static universal context,
6159 -- in which case the integer argument must be converted explicitly.
6161 elsif Typ = Universal_Real
6162 and then Is_Integer_Type (Rtyp)
6164 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
6166 Analyze_And_Resolve (Rop, Universal_Real);
6168 elsif Typ = Universal_Real
6169 and then Is_Integer_Type (Ltyp)
6171 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
6173 Analyze_And_Resolve (Lop, Universal_Real);
6175 -- Non-fixed point cases, check software overflow checking required
6177 elsif Is_Signed_Integer_Type (Etype (N)) then
6178 Apply_Arithmetic_Overflow_Check (N);
6180 -- Deal with VAX float case
6182 elsif Vax_Float (Typ) then
6183 Expand_Vax_Arith (N);
6186 end Expand_N_Op_Multiply;
6188 --------------------
6189 -- Expand_N_Op_Ne --
6190 --------------------
6192 procedure Expand_N_Op_Ne (N : Node_Id) is
6193 Typ : constant Entity_Id := Etype (Left_Opnd (N));
6196 -- Case of elementary type with standard operator
6198 if Is_Elementary_Type (Typ)
6199 and then Sloc (Entity (N)) = Standard_Location
6201 Binary_Op_Validity_Checks (N);
6203 -- Boolean types (requiring handling of non-standard case)
6205 if Is_Boolean_Type (Typ) then
6206 Adjust_Condition (Left_Opnd (N));
6207 Adjust_Condition (Right_Opnd (N));
6208 Set_Etype (N, Standard_Boolean);
6209 Adjust_Result_Type (N, Typ);
6212 Rewrite_Comparison (N);
6214 -- If we still have comparison for Vax_Float, process it
6216 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
6217 Expand_Vax_Comparison (N);
6221 -- For all cases other than elementary types, we rewrite node as the
6222 -- negation of an equality operation, and reanalyze. The equality to be
6223 -- used is defined in the same scope and has the same signature. This
6224 -- signature must be set explicitly since in an instance it may not have
6225 -- the same visibility as in the generic unit. This avoids duplicating
6226 -- or factoring the complex code for record/array equality tests etc.
6230 Loc : constant Source_Ptr := Sloc (N);
6232 Ne : constant Entity_Id := Entity (N);
6235 Binary_Op_Validity_Checks (N);
6241 Left_Opnd => Left_Opnd (N),
6242 Right_Opnd => Right_Opnd (N)));
6243 Set_Paren_Count (Right_Opnd (Neg), 1);
6245 if Scope (Ne) /= Standard_Standard then
6246 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
6249 -- For navigation purposes, the inequality is treated as an
6250 -- implicit reference to the corresponding equality. Preserve the
6251 -- Comes_From_ source flag so that the proper Xref entry is
6254 Preserve_Comes_From_Source (Neg, N);
6255 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
6257 Analyze_And_Resolve (N, Standard_Boolean);
6262 ---------------------
6263 -- Expand_N_Op_Not --
6264 ---------------------
6266 -- If the argument is other than a Boolean array type, there is no special
6267 -- expansion required.
6269 -- For the packed case, we call the special routine in Exp_Pakd, except
6270 -- that if the component size is greater than one, we use the standard
6271 -- routine generating a gruesome loop (it is so peculiar to have packed
6272 -- arrays with non-standard Boolean representations anyway, so it does not
6273 -- matter that we do not handle this case efficiently).
6275 -- For the unpacked case (and for the special packed case where we have non
6276 -- standard Booleans, as discussed above), we generate and insert into the
6277 -- tree the following function definition:
6279 -- function Nnnn (A : arr) is
6282 -- for J in a'range loop
6283 -- B (J) := not A (J);
6288 -- Here arr is the actual subtype of the parameter (and hence always
6289 -- constrained). Then we replace the not with a call to this function.
6291 procedure Expand_N_Op_Not (N : Node_Id) is
6292 Loc : constant Source_Ptr := Sloc (N);
6293 Typ : constant Entity_Id := Etype (N);
6302 Func_Name : Entity_Id;
6303 Loop_Statement : Node_Id;
6306 Unary_Op_Validity_Checks (N);
6308 -- For boolean operand, deal with non-standard booleans
6310 if Is_Boolean_Type (Typ) then
6311 Adjust_Condition (Right_Opnd (N));
6312 Set_Etype (N, Standard_Boolean);
6313 Adjust_Result_Type (N, Typ);
6317 -- Only array types need any other processing
6319 if not Is_Array_Type (Typ) then
6323 -- Case of array operand. If bit packed with a component size of 1,
6324 -- handle it in Exp_Pakd if the operand is known to be aligned.
6326 if Is_Bit_Packed_Array (Typ)
6327 and then Component_Size (Typ) = 1
6328 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
6330 Expand_Packed_Not (N);
6334 -- Case of array operand which is not bit-packed. If the context is
6335 -- a safe assignment, call in-place operation, If context is a larger
6336 -- boolean expression in the context of a safe assignment, expansion is
6337 -- done by enclosing operation.
6339 Opnd := Relocate_Node (Right_Opnd (N));
6340 Convert_To_Actual_Subtype (Opnd);
6341 Arr := Etype (Opnd);
6342 Ensure_Defined (Arr, N);
6343 Silly_Boolean_Array_Not_Test (N, Arr);
6345 if Nkind (Parent (N)) = N_Assignment_Statement then
6346 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
6347 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
6350 -- Special case the negation of a binary operation
6352 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
6353 and then Safe_In_Place_Array_Op
6354 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
6356 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
6360 elsif Nkind (Parent (N)) in N_Binary_Op
6361 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
6364 Op1 : constant Node_Id := Left_Opnd (Parent (N));
6365 Op2 : constant Node_Id := Right_Opnd (Parent (N));
6366 Lhs : constant Node_Id := Name (Parent (Parent (N)));
6369 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
6371 and then Nkind (Op2) = N_Op_Not
6373 -- (not A) op (not B) can be reduced to a single call
6378 and then Nkind (Parent (N)) = N_Op_Xor
6380 -- A xor (not B) can also be special-cased
6388 A := Make_Defining_Identifier (Loc, Name_uA);
6389 B := Make_Defining_Identifier (Loc, Name_uB);
6390 J := Make_Defining_Identifier (Loc, Name_uJ);
6393 Make_Indexed_Component (Loc,
6394 Prefix => New_Reference_To (A, Loc),
6395 Expressions => New_List (New_Reference_To (J, Loc)));
6398 Make_Indexed_Component (Loc,
6399 Prefix => New_Reference_To (B, Loc),
6400 Expressions => New_List (New_Reference_To (J, Loc)));
6403 Make_Implicit_Loop_Statement (N,
6404 Identifier => Empty,
6407 Make_Iteration_Scheme (Loc,
6408 Loop_Parameter_Specification =>
6409 Make_Loop_Parameter_Specification (Loc,
6410 Defining_Identifier => J,
6411 Discrete_Subtype_Definition =>
6412 Make_Attribute_Reference (Loc,
6413 Prefix => Make_Identifier (Loc, Chars (A)),
6414 Attribute_Name => Name_Range))),
6416 Statements => New_List (
6417 Make_Assignment_Statement (Loc,
6419 Expression => Make_Op_Not (Loc, A_J))));
6421 Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('N'));
6422 Set_Is_Inlined (Func_Name);
6425 Make_Subprogram_Body (Loc,
6427 Make_Function_Specification (Loc,
6428 Defining_Unit_Name => Func_Name,
6429 Parameter_Specifications => New_List (
6430 Make_Parameter_Specification (Loc,
6431 Defining_Identifier => A,
6432 Parameter_Type => New_Reference_To (Typ, Loc))),
6433 Result_Definition => New_Reference_To (Typ, Loc)),
6435 Declarations => New_List (
6436 Make_Object_Declaration (Loc,
6437 Defining_Identifier => B,
6438 Object_Definition => New_Reference_To (Arr, Loc))),
6440 Handled_Statement_Sequence =>
6441 Make_Handled_Sequence_Of_Statements (Loc,
6442 Statements => New_List (
6444 Make_Simple_Return_Statement (Loc,
6446 Make_Identifier (Loc, Chars (B)))))));
6449 Make_Function_Call (Loc,
6450 Name => New_Reference_To (Func_Name, Loc),
6451 Parameter_Associations => New_List (Opnd)));
6453 Analyze_And_Resolve (N, Typ);
6454 end Expand_N_Op_Not;
6456 --------------------
6457 -- Expand_N_Op_Or --
6458 --------------------
6460 procedure Expand_N_Op_Or (N : Node_Id) is
6461 Typ : constant Entity_Id := Etype (N);
6464 Binary_Op_Validity_Checks (N);
6466 if Is_Array_Type (Etype (N)) then
6467 Expand_Boolean_Operator (N);
6469 elsif Is_Boolean_Type (Etype (N)) then
6470 Adjust_Condition (Left_Opnd (N));
6471 Adjust_Condition (Right_Opnd (N));
6472 Set_Etype (N, Standard_Boolean);
6473 Adjust_Result_Type (N, Typ);
6477 ----------------------
6478 -- Expand_N_Op_Plus --
6479 ----------------------
6481 procedure Expand_N_Op_Plus (N : Node_Id) is
6483 Unary_Op_Validity_Checks (N);
6484 end Expand_N_Op_Plus;
6486 ---------------------
6487 -- Expand_N_Op_Rem --
6488 ---------------------
6490 procedure Expand_N_Op_Rem (N : Node_Id) is
6491 Loc : constant Source_Ptr := Sloc (N);
6492 Typ : constant Entity_Id := Etype (N);
6494 Left : constant Node_Id := Left_Opnd (N);
6495 Right : constant Node_Id := Right_Opnd (N);
6505 pragma Warnings (Off, Lhi);
6508 Binary_Op_Validity_Checks (N);
6510 if Is_Integer_Type (Etype (N)) then
6511 Apply_Divide_Check (N);
6514 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
6515 -- but it is useful with other back ends (e.g. AAMP), and is certainly
6518 if Is_Integer_Type (Etype (N))
6519 and then Compile_Time_Known_Value (Right)
6520 and then Expr_Value (Right) = Uint_1
6522 -- Call Remove_Side_Effects to ensure that any side effects in the
6523 -- ignored left operand (in particular function calls to user defined
6524 -- functions) are properly executed.
6526 Remove_Side_Effects (Left);
6528 Rewrite (N, Make_Integer_Literal (Loc, 0));
6529 Analyze_And_Resolve (N, Typ);
6533 -- Deal with annoying case of largest negative number remainder minus
6534 -- one. Gigi does not handle this case correctly, because it generates
6535 -- a divide instruction which may trap in this case.
6537 -- In fact the check is quite easy, if the right operand is -1, then
6538 -- the remainder is always 0, and we can just ignore the left operand
6539 -- completely in this case.
6541 Determine_Range (Right, ROK, Rlo, Rhi);
6542 Determine_Range (Left, LOK, Llo, Lhi);
6544 -- The operand type may be private (e.g. in the expansion of an
6545 -- intrinsic operation) so we must use the underlying type to get the
6546 -- bounds, and convert the literals explicitly.
6550 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
6552 -- Now perform the test, generating code only if needed
6554 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
6556 ((not LOK) or else (Llo = LLB))
6559 Make_Conditional_Expression (Loc,
6560 Expressions => New_List (
6562 Left_Opnd => Duplicate_Subexpr (Right),
6564 Unchecked_Convert_To (Typ,
6565 Make_Integer_Literal (Loc, -1))),
6567 Unchecked_Convert_To (Typ,
6568 Make_Integer_Literal (Loc, Uint_0)),
6570 Relocate_Node (N))));
6572 Set_Analyzed (Next (Next (First (Expressions (N)))));
6573 Analyze_And_Resolve (N, Typ);
6575 end Expand_N_Op_Rem;
6577 -----------------------------
6578 -- Expand_N_Op_Rotate_Left --
6579 -----------------------------
6581 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
6583 Binary_Op_Validity_Checks (N);
6584 end Expand_N_Op_Rotate_Left;
6586 ------------------------------
6587 -- Expand_N_Op_Rotate_Right --
6588 ------------------------------
6590 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
6592 Binary_Op_Validity_Checks (N);
6593 end Expand_N_Op_Rotate_Right;
6595 ----------------------------
6596 -- Expand_N_Op_Shift_Left --
6597 ----------------------------
6599 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
6601 Binary_Op_Validity_Checks (N);
6602 end Expand_N_Op_Shift_Left;
6604 -----------------------------
6605 -- Expand_N_Op_Shift_Right --
6606 -----------------------------
6608 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
6610 Binary_Op_Validity_Checks (N);
6611 end Expand_N_Op_Shift_Right;
6613 ----------------------------------------
6614 -- Expand_N_Op_Shift_Right_Arithmetic --
6615 ----------------------------------------
6617 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
6619 Binary_Op_Validity_Checks (N);
6620 end Expand_N_Op_Shift_Right_Arithmetic;
6622 --------------------------
6623 -- Expand_N_Op_Subtract --
6624 --------------------------
6626 procedure Expand_N_Op_Subtract (N : Node_Id) is
6627 Typ : constant Entity_Id := Etype (N);
6630 Binary_Op_Validity_Checks (N);
6632 -- N - 0 = N for integer types
6634 if Is_Integer_Type (Typ)
6635 and then Compile_Time_Known_Value (Right_Opnd (N))
6636 and then Expr_Value (Right_Opnd (N)) = 0
6638 Rewrite (N, Left_Opnd (N));
6642 -- Arithmetic overflow checks for signed integer/fixed point types
6644 if Is_Signed_Integer_Type (Typ)
6645 or else Is_Fixed_Point_Type (Typ)
6647 Apply_Arithmetic_Overflow_Check (N);
6649 -- Vax floating-point types case
6651 elsif Vax_Float (Typ) then
6652 Expand_Vax_Arith (N);
6654 end Expand_N_Op_Subtract;
6656 ---------------------
6657 -- Expand_N_Op_Xor --
6658 ---------------------
6660 procedure Expand_N_Op_Xor (N : Node_Id) is
6661 Typ : constant Entity_Id := Etype (N);
6664 Binary_Op_Validity_Checks (N);
6666 if Is_Array_Type (Etype (N)) then
6667 Expand_Boolean_Operator (N);
6669 elsif Is_Boolean_Type (Etype (N)) then
6670 Adjust_Condition (Left_Opnd (N));
6671 Adjust_Condition (Right_Opnd (N));
6672 Set_Etype (N, Standard_Boolean);
6673 Adjust_Result_Type (N, Typ);
6675 end Expand_N_Op_Xor;
6677 ----------------------
6678 -- Expand_N_Or_Else --
6679 ----------------------
6681 -- Expand into conditional expression if Actions present, and also
6682 -- deal with optimizing case of arguments being True or False.
6684 procedure Expand_N_Or_Else (N : Node_Id) is
6685 Loc : constant Source_Ptr := Sloc (N);
6686 Typ : constant Entity_Id := Etype (N);
6687 Left : constant Node_Id := Left_Opnd (N);
6688 Right : constant Node_Id := Right_Opnd (N);
6692 -- Deal with non-standard booleans
6694 if Is_Boolean_Type (Typ) then
6695 Adjust_Condition (Left);
6696 Adjust_Condition (Right);
6697 Set_Etype (N, Standard_Boolean);
6700 -- Check for cases where left argument is known to be True or False
6702 if Compile_Time_Known_Value (Left) then
6704 -- If left argument is False, change (False or else Right) to Right.
6705 -- Any actions associated with Right will be executed unconditionally
6706 -- and can thus be inserted into the tree unconditionally.
6708 if Expr_Value_E (Left) = Standard_False then
6709 if Present (Actions (N)) then
6710 Insert_Actions (N, Actions (N));
6715 -- If left argument is True, change (True and then Right) to True. In
6716 -- this case we can forget the actions associated with Right, since
6717 -- they will never be executed.
6719 else pragma Assert (Expr_Value_E (Left) = Standard_True);
6720 Kill_Dead_Code (Right);
6721 Kill_Dead_Code (Actions (N));
6722 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
6725 Adjust_Result_Type (N, Typ);
6729 -- If Actions are present, we expand
6731 -- left or else right
6735 -- if left then True else right end
6737 -- with the actions becoming the Else_Actions of the conditional
6738 -- expression. This conditional expression is then further expanded
6739 -- (and will eventually disappear)
6741 if Present (Actions (N)) then
6742 Actlist := Actions (N);
6744 Make_Conditional_Expression (Loc,
6745 Expressions => New_List (
6747 New_Occurrence_Of (Standard_True, Loc),
6750 Set_Else_Actions (N, Actlist);
6751 Analyze_And_Resolve (N, Standard_Boolean);
6752 Adjust_Result_Type (N, Typ);
6756 -- No actions present, check for cases of right argument True/False
6758 if Compile_Time_Known_Value (Right) then
6760 -- Change (Left or else False) to Left. Note that we know there are
6761 -- no actions associated with the True operand, since we just checked
6762 -- for this case above.
6764 if Expr_Value_E (Right) = Standard_False then
6767 -- Change (Left or else True) to True, making sure to preserve any
6768 -- side effects associated with the Left operand.
6770 else pragma Assert (Expr_Value_E (Right) = Standard_True);
6771 Remove_Side_Effects (Left);
6773 (N, New_Occurrence_Of (Standard_True, Loc));
6777 Adjust_Result_Type (N, Typ);
6778 end Expand_N_Or_Else;
6780 -----------------------------------
6781 -- Expand_N_Qualified_Expression --
6782 -----------------------------------
6784 procedure Expand_N_Qualified_Expression (N : Node_Id) is
6785 Operand : constant Node_Id := Expression (N);
6786 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
6789 -- Do validity check if validity checking operands
6791 if Validity_Checks_On
6792 and then Validity_Check_Operands
6794 Ensure_Valid (Operand);
6797 -- Apply possible constraint check
6799 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
6800 end Expand_N_Qualified_Expression;
6802 ---------------------------------
6803 -- Expand_N_Selected_Component --
6804 ---------------------------------
6806 -- If the selector is a discriminant of a concurrent object, rewrite the
6807 -- prefix to denote the corresponding record type.
6809 procedure Expand_N_Selected_Component (N : Node_Id) is
6810 Loc : constant Source_Ptr := Sloc (N);
6811 Par : constant Node_Id := Parent (N);
6812 P : constant Node_Id := Prefix (N);
6813 Ptyp : Entity_Id := Underlying_Type (Etype (P));
6818 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
6819 -- Gigi needs a temporary for prefixes that depend on a discriminant,
6820 -- unless the context of an assignment can provide size information.
6821 -- Don't we have a general routine that does this???
6823 -----------------------
6824 -- In_Left_Hand_Side --
6825 -----------------------
6827 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
6829 return (Nkind (Parent (Comp)) = N_Assignment_Statement
6830 and then Comp = Name (Parent (Comp)))
6831 or else (Present (Parent (Comp))
6832 and then Nkind (Parent (Comp)) in N_Subexpr
6833 and then In_Left_Hand_Side (Parent (Comp)));
6834 end In_Left_Hand_Side;
6836 -- Start of processing for Expand_N_Selected_Component
6839 -- Insert explicit dereference if required
6841 if Is_Access_Type (Ptyp) then
6842 Insert_Explicit_Dereference (P);
6843 Analyze_And_Resolve (P, Designated_Type (Ptyp));
6845 if Ekind (Etype (P)) = E_Private_Subtype
6846 and then Is_For_Access_Subtype (Etype (P))
6848 Set_Etype (P, Base_Type (Etype (P)));
6854 -- Deal with discriminant check required
6856 if Do_Discriminant_Check (N) then
6858 -- Present the discriminant checking function to the backend, so that
6859 -- it can inline the call to the function.
6862 (Discriminant_Checking_Func
6863 (Original_Record_Component (Entity (Selector_Name (N)))));
6865 -- Now reset the flag and generate the call
6867 Set_Do_Discriminant_Check (N, False);
6868 Generate_Discriminant_Check (N);
6871 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
6872 -- function, then additional actuals must be passed.
6874 if Ada_Version >= Ada_05
6875 and then Is_Build_In_Place_Function_Call (P)
6877 Make_Build_In_Place_Call_In_Anonymous_Context (P);
6880 -- Gigi cannot handle unchecked conversions that are the prefix of a
6881 -- selected component with discriminants. This must be checked during
6882 -- expansion, because during analysis the type of the selector is not
6883 -- known at the point the prefix is analyzed. If the conversion is the
6884 -- target of an assignment, then we cannot force the evaluation.
6886 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
6887 and then Has_Discriminants (Etype (N))
6888 and then not In_Left_Hand_Side (N)
6890 Force_Evaluation (Prefix (N));
6893 -- Remaining processing applies only if selector is a discriminant
6895 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
6897 -- If the selector is a discriminant of a constrained record type,
6898 -- we may be able to rewrite the expression with the actual value
6899 -- of the discriminant, a useful optimization in some cases.
6901 if Is_Record_Type (Ptyp)
6902 and then Has_Discriminants (Ptyp)
6903 and then Is_Constrained (Ptyp)
6905 -- Do this optimization for discrete types only, and not for
6906 -- access types (access discriminants get us into trouble!)
6908 if not Is_Discrete_Type (Etype (N)) then
6911 -- Don't do this on the left hand of an assignment statement.
6912 -- Normally one would think that references like this would
6913 -- not occur, but they do in generated code, and mean that
6914 -- we really do want to assign the discriminant!
6916 elsif Nkind (Par) = N_Assignment_Statement
6917 and then Name (Par) = N
6921 -- Don't do this optimization for the prefix of an attribute or
6922 -- the operand of an object renaming declaration since these are
6923 -- contexts where we do not want the value anyway.
6925 elsif (Nkind (Par) = N_Attribute_Reference
6926 and then Prefix (Par) = N)
6927 or else Is_Renamed_Object (N)
6931 -- Don't do this optimization if we are within the code for a
6932 -- discriminant check, since the whole point of such a check may
6933 -- be to verify the condition on which the code below depends!
6935 elsif Is_In_Discriminant_Check (N) then
6938 -- Green light to see if we can do the optimization. There is
6939 -- still one condition that inhibits the optimization below but
6940 -- now is the time to check the particular discriminant.
6943 -- Loop through discriminants to find the matching discriminant
6944 -- constraint to see if we can copy it.
6946 Disc := First_Discriminant (Ptyp);
6947 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
6948 Discr_Loop : while Present (Dcon) loop
6950 -- Check if this is the matching discriminant
6952 if Disc = Entity (Selector_Name (N)) then
6954 -- Here we have the matching discriminant. Check for
6955 -- the case of a discriminant of a component that is
6956 -- constrained by an outer discriminant, which cannot
6957 -- be optimized away.
6960 Denotes_Discriminant
6961 (Node (Dcon), Check_Concurrent => True)
6965 -- In the context of a case statement, the expression may
6966 -- have the base type of the discriminant, and we need to
6967 -- preserve the constraint to avoid spurious errors on
6970 elsif Nkind (Parent (N)) = N_Case_Statement
6971 and then Etype (Node (Dcon)) /= Etype (Disc)
6974 Make_Qualified_Expression (Loc,
6976 New_Occurrence_Of (Etype (Disc), Loc),
6978 New_Copy_Tree (Node (Dcon))));
6979 Analyze_And_Resolve (N, Etype (Disc));
6981 -- In case that comes out as a static expression,
6982 -- reset it (a selected component is never static).
6984 Set_Is_Static_Expression (N, False);
6987 -- Otherwise we can just copy the constraint, but the
6988 -- result is certainly not static! In some cases the
6989 -- discriminant constraint has been analyzed in the
6990 -- context of the original subtype indication, but for
6991 -- itypes the constraint might not have been analyzed
6992 -- yet, and this must be done now.
6995 Rewrite (N, New_Copy_Tree (Node (Dcon)));
6996 Analyze_And_Resolve (N);
6997 Set_Is_Static_Expression (N, False);
7003 Next_Discriminant (Disc);
7004 end loop Discr_Loop;
7006 -- Note: the above loop should always find a matching
7007 -- discriminant, but if it does not, we just missed an
7008 -- optimization due to some glitch (perhaps a previous error),
7014 -- The only remaining processing is in the case of a discriminant of
7015 -- a concurrent object, where we rewrite the prefix to denote the
7016 -- corresponding record type. If the type is derived and has renamed
7017 -- discriminants, use corresponding discriminant, which is the one
7018 -- that appears in the corresponding record.
7020 if not Is_Concurrent_Type (Ptyp) then
7024 Disc := Entity (Selector_Name (N));
7026 if Is_Derived_Type (Ptyp)
7027 and then Present (Corresponding_Discriminant (Disc))
7029 Disc := Corresponding_Discriminant (Disc);
7033 Make_Selected_Component (Loc,
7035 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
7037 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
7042 end Expand_N_Selected_Component;
7044 --------------------
7045 -- Expand_N_Slice --
7046 --------------------
7048 procedure Expand_N_Slice (N : Node_Id) is
7049 Loc : constant Source_Ptr := Sloc (N);
7050 Typ : constant Entity_Id := Etype (N);
7051 Pfx : constant Node_Id := Prefix (N);
7052 Ptp : Entity_Id := Etype (Pfx);
7054 function Is_Procedure_Actual (N : Node_Id) return Boolean;
7055 -- Check whether the argument is an actual for a procedure call, in
7056 -- which case the expansion of a bit-packed slice is deferred until the
7057 -- call itself is expanded. The reason this is required is that we might
7058 -- have an IN OUT or OUT parameter, and the copy out is essential, and
7059 -- that copy out would be missed if we created a temporary here in
7060 -- Expand_N_Slice. Note that we don't bother to test specifically for an
7061 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
7062 -- is harmless to defer expansion in the IN case, since the call
7063 -- processing will still generate the appropriate copy in operation,
7064 -- which will take care of the slice.
7066 procedure Make_Temporary;
7067 -- Create a named variable for the value of the slice, in cases where
7068 -- the back-end cannot handle it properly, e.g. when packed types or
7069 -- unaligned slices are involved.
7071 -------------------------
7072 -- Is_Procedure_Actual --
7073 -------------------------
7075 function Is_Procedure_Actual (N : Node_Id) return Boolean is
7076 Par : Node_Id := Parent (N);
7080 -- If our parent is a procedure call we can return
7082 if Nkind (Par) = N_Procedure_Call_Statement then
7085 -- If our parent is a type conversion, keep climbing the tree,
7086 -- since a type conversion can be a procedure actual. Also keep
7087 -- climbing if parameter association or a qualified expression,
7088 -- since these are additional cases that do can appear on
7089 -- procedure actuals.
7091 elsif Nkind_In (Par, N_Type_Conversion,
7092 N_Parameter_Association,
7093 N_Qualified_Expression)
7095 Par := Parent (Par);
7097 -- Any other case is not what we are looking for
7103 end Is_Procedure_Actual;
7105 --------------------
7106 -- Make_Temporary --
7107 --------------------
7109 procedure Make_Temporary is
7111 Ent : constant Entity_Id :=
7112 Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
7115 Make_Object_Declaration (Loc,
7116 Defining_Identifier => Ent,
7117 Object_Definition => New_Occurrence_Of (Typ, Loc));
7119 Set_No_Initialization (Decl);
7121 Insert_Actions (N, New_List (
7123 Make_Assignment_Statement (Loc,
7124 Name => New_Occurrence_Of (Ent, Loc),
7125 Expression => Relocate_Node (N))));
7127 Rewrite (N, New_Occurrence_Of (Ent, Loc));
7128 Analyze_And_Resolve (N, Typ);
7131 -- Start of processing for Expand_N_Slice
7134 -- Special handling for access types
7136 if Is_Access_Type (Ptp) then
7138 Ptp := Designated_Type (Ptp);
7141 Make_Explicit_Dereference (Sloc (N),
7142 Prefix => Relocate_Node (Pfx)));
7144 Analyze_And_Resolve (Pfx, Ptp);
7147 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7148 -- function, then additional actuals must be passed.
7150 if Ada_Version >= Ada_05
7151 and then Is_Build_In_Place_Function_Call (Pfx)
7153 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
7156 -- Range checks are potentially also needed for cases involving a slice
7157 -- indexed by a subtype indication, but Do_Range_Check can currently
7158 -- only be set for expressions ???
7160 if not Index_Checks_Suppressed (Ptp)
7161 and then (not Is_Entity_Name (Pfx)
7162 or else not Index_Checks_Suppressed (Entity (Pfx)))
7163 and then Nkind (Discrete_Range (N)) /= N_Subtype_Indication
7165 -- Do not enable range check to nodes associated with the frontend
7166 -- expansion of the dispatch table. We first check if Ada.Tags is
7167 -- already loaded to avoid the addition of an undesired dependence
7168 -- on such run-time unit.
7173 (RTU_Loaded (Ada_Tags)
7174 and then Nkind (Prefix (N)) = N_Selected_Component
7175 and then Present (Entity (Selector_Name (Prefix (N))))
7176 and then Entity (Selector_Name (Prefix (N))) =
7177 RTE_Record_Component (RE_Prims_Ptr)))
7179 Enable_Range_Check (Discrete_Range (N));
7182 -- The remaining case to be handled is packed slices. We can leave
7183 -- packed slices as they are in the following situations:
7185 -- 1. Right or left side of an assignment (we can handle this
7186 -- situation correctly in the assignment statement expansion).
7188 -- 2. Prefix of indexed component (the slide is optimized away in this
7189 -- case, see the start of Expand_N_Slice.)
7191 -- 3. Object renaming declaration, since we want the name of the
7192 -- slice, not the value.
7194 -- 4. Argument to procedure call, since copy-in/copy-out handling may
7195 -- be required, and this is handled in the expansion of call
7198 -- 5. Prefix of an address attribute (this is an error which is caught
7199 -- elsewhere, and the expansion would interfere with generating the
7202 if not Is_Packed (Typ) then
7204 -- Apply transformation for actuals of a function call, where
7205 -- Expand_Actuals is not used.
7207 if Nkind (Parent (N)) = N_Function_Call
7208 and then Is_Possibly_Unaligned_Slice (N)
7213 elsif Nkind (Parent (N)) = N_Assignment_Statement
7214 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
7215 and then Parent (N) = Name (Parent (Parent (N))))
7219 elsif Nkind (Parent (N)) = N_Indexed_Component
7220 or else Is_Renamed_Object (N)
7221 or else Is_Procedure_Actual (N)
7225 elsif Nkind (Parent (N)) = N_Attribute_Reference
7226 and then Attribute_Name (Parent (N)) = Name_Address
7235 ------------------------------
7236 -- Expand_N_Type_Conversion --
7237 ------------------------------
7239 procedure Expand_N_Type_Conversion (N : Node_Id) is
7240 Loc : constant Source_Ptr := Sloc (N);
7241 Operand : constant Node_Id := Expression (N);
7242 Target_Type : constant Entity_Id := Etype (N);
7243 Operand_Type : Entity_Id := Etype (Operand);
7245 procedure Handle_Changed_Representation;
7246 -- This is called in the case of record and array type conversions to
7247 -- see if there is a change of representation to be handled. Change of
7248 -- representation is actually handled at the assignment statement level,
7249 -- and what this procedure does is rewrite node N conversion as an
7250 -- assignment to temporary. If there is no change of representation,
7251 -- then the conversion node is unchanged.
7253 procedure Real_Range_Check;
7254 -- Handles generation of range check for real target value
7256 -----------------------------------
7257 -- Handle_Changed_Representation --
7258 -----------------------------------
7260 procedure Handle_Changed_Representation is
7269 -- Nothing else to do if no change of representation
7271 if Same_Representation (Operand_Type, Target_Type) then
7274 -- The real change of representation work is done by the assignment
7275 -- statement processing. So if this type conversion is appearing as
7276 -- the expression of an assignment statement, nothing needs to be
7277 -- done to the conversion.
7279 elsif Nkind (Parent (N)) = N_Assignment_Statement then
7282 -- Otherwise we need to generate a temporary variable, and do the
7283 -- change of representation assignment into that temporary variable.
7284 -- The conversion is then replaced by a reference to this variable.
7289 -- If type is unconstrained we have to add a constraint, copied
7290 -- from the actual value of the left hand side.
7292 if not Is_Constrained (Target_Type) then
7293 if Has_Discriminants (Operand_Type) then
7294 Disc := First_Discriminant (Operand_Type);
7296 if Disc /= First_Stored_Discriminant (Operand_Type) then
7297 Disc := First_Stored_Discriminant (Operand_Type);
7301 while Present (Disc) loop
7303 Make_Selected_Component (Loc,
7304 Prefix => Duplicate_Subexpr_Move_Checks (Operand),
7306 Make_Identifier (Loc, Chars (Disc))));
7307 Next_Discriminant (Disc);
7310 elsif Is_Array_Type (Operand_Type) then
7311 N_Ix := First_Index (Target_Type);
7314 for J in 1 .. Number_Dimensions (Operand_Type) loop
7316 -- We convert the bounds explicitly. We use an unchecked
7317 -- conversion because bounds checks are done elsewhere.
7322 Unchecked_Convert_To (Etype (N_Ix),
7323 Make_Attribute_Reference (Loc,
7325 Duplicate_Subexpr_No_Checks
7326 (Operand, Name_Req => True),
7327 Attribute_Name => Name_First,
7328 Expressions => New_List (
7329 Make_Integer_Literal (Loc, J)))),
7332 Unchecked_Convert_To (Etype (N_Ix),
7333 Make_Attribute_Reference (Loc,
7335 Duplicate_Subexpr_No_Checks
7336 (Operand, Name_Req => True),
7337 Attribute_Name => Name_Last,
7338 Expressions => New_List (
7339 Make_Integer_Literal (Loc, J))))));
7346 Odef := New_Occurrence_Of (Target_Type, Loc);
7348 if Present (Cons) then
7350 Make_Subtype_Indication (Loc,
7351 Subtype_Mark => Odef,
7353 Make_Index_Or_Discriminant_Constraint (Loc,
7354 Constraints => Cons));
7357 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
7359 Make_Object_Declaration (Loc,
7360 Defining_Identifier => Temp,
7361 Object_Definition => Odef);
7363 Set_No_Initialization (Decl, True);
7365 -- Insert required actions. It is essential to suppress checks
7366 -- since we have suppressed default initialization, which means
7367 -- that the variable we create may have no discriminants.
7372 Make_Assignment_Statement (Loc,
7373 Name => New_Occurrence_Of (Temp, Loc),
7374 Expression => Relocate_Node (N))),
7375 Suppress => All_Checks);
7377 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7380 end Handle_Changed_Representation;
7382 ----------------------
7383 -- Real_Range_Check --
7384 ----------------------
7386 -- Case of conversions to floating-point or fixed-point. If range checks
7387 -- are enabled and the target type has a range constraint, we convert:
7393 -- Tnn : typ'Base := typ'Base (x);
7394 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
7397 -- This is necessary when there is a conversion of integer to float or
7398 -- to fixed-point to ensure that the correct checks are made. It is not
7399 -- necessary for float to float where it is enough to simply set the
7400 -- Do_Range_Check flag.
7402 procedure Real_Range_Check is
7403 Btyp : constant Entity_Id := Base_Type (Target_Type);
7404 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
7405 Hi : constant Node_Id := Type_High_Bound (Target_Type);
7406 Xtyp : constant Entity_Id := Etype (Operand);
7411 -- Nothing to do if conversion was rewritten
7413 if Nkind (N) /= N_Type_Conversion then
7417 -- Nothing to do if range checks suppressed, or target has the same
7418 -- range as the base type (or is the base type).
7420 if Range_Checks_Suppressed (Target_Type)
7421 or else (Lo = Type_Low_Bound (Btyp)
7423 Hi = Type_High_Bound (Btyp))
7428 -- Nothing to do if expression is an entity on which checks have been
7431 if Is_Entity_Name (Operand)
7432 and then Range_Checks_Suppressed (Entity (Operand))
7437 -- Nothing to do if bounds are all static and we can tell that the
7438 -- expression is within the bounds of the target. Note that if the
7439 -- operand is of an unconstrained floating-point type, then we do
7440 -- not trust it to be in range (might be infinite)
7443 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
7444 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
7447 if (not Is_Floating_Point_Type (Xtyp)
7448 or else Is_Constrained (Xtyp))
7449 and then Compile_Time_Known_Value (S_Lo)
7450 and then Compile_Time_Known_Value (S_Hi)
7451 and then Compile_Time_Known_Value (Hi)
7452 and then Compile_Time_Known_Value (Lo)
7455 D_Lov : constant Ureal := Expr_Value_R (Lo);
7456 D_Hiv : constant Ureal := Expr_Value_R (Hi);
7461 if Is_Real_Type (Xtyp) then
7462 S_Lov := Expr_Value_R (S_Lo);
7463 S_Hiv := Expr_Value_R (S_Hi);
7465 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
7466 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
7470 and then S_Lov >= D_Lov
7471 and then S_Hiv <= D_Hiv
7473 Set_Do_Range_Check (Operand, False);
7480 -- For float to float conversions, we are done
7482 if Is_Floating_Point_Type (Xtyp)
7484 Is_Floating_Point_Type (Btyp)
7489 -- Otherwise rewrite the conversion as described above
7491 Conv := Relocate_Node (N);
7493 (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
7494 Set_Etype (Conv, Btyp);
7496 -- Enable overflow except for case of integer to float conversions,
7497 -- where it is never required, since we can never have overflow in
7500 if not Is_Integer_Type (Etype (Operand)) then
7501 Enable_Overflow_Check (Conv);
7505 Make_Defining_Identifier (Loc,
7506 Chars => New_Internal_Name ('T'));
7508 Insert_Actions (N, New_List (
7509 Make_Object_Declaration (Loc,
7510 Defining_Identifier => Tnn,
7511 Object_Definition => New_Occurrence_Of (Btyp, Loc),
7512 Expression => Conv),
7514 Make_Raise_Constraint_Error (Loc,
7519 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
7521 Make_Attribute_Reference (Loc,
7522 Attribute_Name => Name_First,
7524 New_Occurrence_Of (Target_Type, Loc))),
7528 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
7530 Make_Attribute_Reference (Loc,
7531 Attribute_Name => Name_Last,
7533 New_Occurrence_Of (Target_Type, Loc)))),
7534 Reason => CE_Range_Check_Failed)));
7536 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
7537 Analyze_And_Resolve (N, Btyp);
7538 end Real_Range_Check;
7540 -- Start of processing for Expand_N_Type_Conversion
7543 -- Nothing at all to do if conversion is to the identical type so remove
7544 -- the conversion completely, it is useless.
7546 if Operand_Type = Target_Type then
7547 Rewrite (N, Relocate_Node (Operand));
7551 -- Nothing to do if this is the second argument of read. This is a
7552 -- "backwards" conversion that will be handled by the specialized code
7553 -- in attribute processing.
7555 if Nkind (Parent (N)) = N_Attribute_Reference
7556 and then Attribute_Name (Parent (N)) = Name_Read
7557 and then Next (First (Expressions (Parent (N)))) = N
7562 -- Here if we may need to expand conversion
7564 -- Do validity check if validity checking operands
7566 if Validity_Checks_On
7567 and then Validity_Check_Operands
7569 Ensure_Valid (Operand);
7572 -- Special case of converting from non-standard boolean type
7574 if Is_Boolean_Type (Operand_Type)
7575 and then (Nonzero_Is_True (Operand_Type))
7577 Adjust_Condition (Operand);
7578 Set_Etype (Operand, Standard_Boolean);
7579 Operand_Type := Standard_Boolean;
7582 -- Case of converting to an access type
7584 if Is_Access_Type (Target_Type) then
7586 -- Apply an accessibility check when the conversion operand is an
7587 -- access parameter (or a renaming thereof), unless conversion was
7588 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
7589 -- Note that other checks may still need to be applied below (such
7590 -- as tagged type checks).
7592 if Is_Entity_Name (Operand)
7594 (Is_Formal (Entity (Operand))
7596 (Present (Renamed_Object (Entity (Operand)))
7597 and then Is_Entity_Name (Renamed_Object (Entity (Operand)))
7599 (Entity (Renamed_Object (Entity (Operand))))))
7600 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
7601 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
7602 or else Attribute_Name (Original_Node (N)) = Name_Access)
7604 Apply_Accessibility_Check
7605 (Operand, Target_Type, Insert_Node => Operand);
7607 -- If the level of the operand type is statically deeper than the
7608 -- level of the target type, then force Program_Error. Note that this
7609 -- can only occur for cases where the attribute is within the body of
7610 -- an instantiation (otherwise the conversion will already have been
7611 -- rejected as illegal). Note: warnings are issued by the analyzer
7612 -- for the instance cases.
7614 elsif In_Instance_Body
7615 and then Type_Access_Level (Operand_Type) >
7616 Type_Access_Level (Target_Type)
7619 Make_Raise_Program_Error (Sloc (N),
7620 Reason => PE_Accessibility_Check_Failed));
7621 Set_Etype (N, Target_Type);
7623 -- When the operand is a selected access discriminant the check needs
7624 -- to be made against the level of the object denoted by the prefix
7625 -- of the selected name. Force Program_Error for this case as well
7626 -- (this accessibility violation can only happen if within the body
7627 -- of an instantiation).
7629 elsif In_Instance_Body
7630 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
7631 and then Nkind (Operand) = N_Selected_Component
7632 and then Object_Access_Level (Operand) >
7633 Type_Access_Level (Target_Type)
7636 Make_Raise_Program_Error (Sloc (N),
7637 Reason => PE_Accessibility_Check_Failed));
7638 Set_Etype (N, Target_Type);
7642 -- Case of conversions of tagged types and access to tagged types
7644 -- When needed, that is to say when the expression is class-wide, Add
7645 -- runtime a tag check for (strict) downward conversion by using the
7646 -- membership test, generating:
7648 -- [constraint_error when Operand not in Target_Type'Class]
7650 -- or in the access type case
7652 -- [constraint_error
7653 -- when Operand /= null
7654 -- and then Operand.all not in
7655 -- Designated_Type (Target_Type)'Class]
7657 if (Is_Access_Type (Target_Type)
7658 and then Is_Tagged_Type (Designated_Type (Target_Type)))
7659 or else Is_Tagged_Type (Target_Type)
7661 -- Do not do any expansion in the access type case if the parent is a
7662 -- renaming, since this is an error situation which will be caught by
7663 -- Sem_Ch8, and the expansion can interfere with this error check.
7665 if Is_Access_Type (Target_Type)
7666 and then Is_Renamed_Object (N)
7671 -- Otherwise, proceed with processing tagged conversion
7674 Actual_Op_Typ : Entity_Id;
7675 Actual_Targ_Typ : Entity_Id;
7676 Make_Conversion : Boolean := False;
7677 Root_Op_Typ : Entity_Id;
7679 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
7680 -- Create a membership check to test whether Operand is a member
7681 -- of Targ_Typ. If the original Target_Type is an access, include
7682 -- a test for null value. The check is inserted at N.
7684 --------------------
7685 -- Make_Tag_Check --
7686 --------------------
7688 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
7693 -- [Constraint_Error
7694 -- when Operand /= null
7695 -- and then Operand.all not in Targ_Typ]
7697 if Is_Access_Type (Target_Type) then
7702 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
7703 Right_Opnd => Make_Null (Loc)),
7708 Make_Explicit_Dereference (Loc,
7709 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
7710 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
7713 -- [Constraint_Error when Operand not in Targ_Typ]
7718 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
7719 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
7723 Make_Raise_Constraint_Error (Loc,
7725 Reason => CE_Tag_Check_Failed));
7728 -- Start of processing
7731 if Is_Access_Type (Target_Type) then
7732 Actual_Op_Typ := Designated_Type (Operand_Type);
7733 Actual_Targ_Typ := Designated_Type (Target_Type);
7736 Actual_Op_Typ := Operand_Type;
7737 Actual_Targ_Typ := Target_Type;
7740 Root_Op_Typ := Root_Type (Actual_Op_Typ);
7742 -- Ada 2005 (AI-251): Handle interface type conversion
7744 if Is_Interface (Actual_Op_Typ) then
7745 Expand_Interface_Conversion (N, Is_Static => False);
7749 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
7751 -- Create a runtime tag check for a downward class-wide type
7754 if Is_Class_Wide_Type (Actual_Op_Typ)
7755 and then Root_Op_Typ /= Actual_Targ_Typ
7756 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ)
7758 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
7759 Make_Conversion := True;
7762 -- AI05-0073: If the result subtype of the function is defined
7763 -- by an access_definition designating a specific tagged type
7764 -- T, a check is made that the result value is null or the tag
7765 -- of the object designated by the result value identifies T.
7766 -- Constraint_Error is raised if this check fails.
7768 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
7771 Func_Typ : Entity_Id;
7774 -- Climb scope stack looking for the enclosing function
7776 Func := Current_Scope;
7777 while Present (Func)
7778 and then Ekind (Func) /= E_Function
7780 Func := Scope (Func);
7783 -- The function's return subtype must be defined using
7784 -- an access definition.
7786 if Nkind (Result_Definition (Parent (Func))) =
7789 Func_Typ := Directly_Designated_Type (Etype (Func));
7791 -- The return subtype denotes a specific tagged type,
7792 -- in other words, a non class-wide type.
7794 if Is_Tagged_Type (Func_Typ)
7795 and then not Is_Class_Wide_Type (Func_Typ)
7797 Make_Tag_Check (Actual_Targ_Typ);
7798 Make_Conversion := True;
7804 -- We have generated a tag check for either a class-wide type
7805 -- conversion or for AI05-0073.
7807 if Make_Conversion then
7812 Make_Unchecked_Type_Conversion (Loc,
7813 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
7814 Expression => Relocate_Node (Expression (N)));
7816 Analyze_And_Resolve (N, Target_Type);
7822 -- Case of other access type conversions
7824 elsif Is_Access_Type (Target_Type) then
7825 Apply_Constraint_Check (Operand, Target_Type);
7827 -- Case of conversions from a fixed-point type
7829 -- These conversions require special expansion and processing, found in
7830 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
7831 -- since from a semantic point of view, these are simple integer
7832 -- conversions, which do not need further processing.
7834 elsif Is_Fixed_Point_Type (Operand_Type)
7835 and then not Conversion_OK (N)
7837 -- We should never see universal fixed at this case, since the
7838 -- expansion of the constituent divide or multiply should have
7839 -- eliminated the explicit mention of universal fixed.
7841 pragma Assert (Operand_Type /= Universal_Fixed);
7843 -- Check for special case of the conversion to universal real that
7844 -- occurs as a result of the use of a round attribute. In this case,
7845 -- the real type for the conversion is taken from the target type of
7846 -- the Round attribute and the result must be marked as rounded.
7848 if Target_Type = Universal_Real
7849 and then Nkind (Parent (N)) = N_Attribute_Reference
7850 and then Attribute_Name (Parent (N)) = Name_Round
7852 Set_Rounded_Result (N);
7853 Set_Etype (N, Etype (Parent (N)));
7856 -- Otherwise do correct fixed-conversion, but skip these if the
7857 -- Conversion_OK flag is set, because from a semantic point of
7858 -- view these are simple integer conversions needing no further
7859 -- processing (the backend will simply treat them as integers)
7861 if not Conversion_OK (N) then
7862 if Is_Fixed_Point_Type (Etype (N)) then
7863 Expand_Convert_Fixed_To_Fixed (N);
7866 elsif Is_Integer_Type (Etype (N)) then
7867 Expand_Convert_Fixed_To_Integer (N);
7870 pragma Assert (Is_Floating_Point_Type (Etype (N)));
7871 Expand_Convert_Fixed_To_Float (N);
7876 -- Case of conversions to a fixed-point type
7878 -- These conversions require special expansion and processing, found in
7879 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
7880 -- since from a semantic point of view, these are simple integer
7881 -- conversions, which do not need further processing.
7883 elsif Is_Fixed_Point_Type (Target_Type)
7884 and then not Conversion_OK (N)
7886 if Is_Integer_Type (Operand_Type) then
7887 Expand_Convert_Integer_To_Fixed (N);
7890 pragma Assert (Is_Floating_Point_Type (Operand_Type));
7891 Expand_Convert_Float_To_Fixed (N);
7895 -- Case of float-to-integer conversions
7897 -- We also handle float-to-fixed conversions with Conversion_OK set
7898 -- since semantically the fixed-point target is treated as though it
7899 -- were an integer in such cases.
7901 elsif Is_Floating_Point_Type (Operand_Type)
7903 (Is_Integer_Type (Target_Type)
7905 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
7907 -- One more check here, gcc is still not able to do conversions of
7908 -- this type with proper overflow checking, and so gigi is doing an
7909 -- approximation of what is required by doing floating-point compares
7910 -- with the end-point. But that can lose precision in some cases, and
7911 -- give a wrong result. Converting the operand to Universal_Real is
7912 -- helpful, but still does not catch all cases with 64-bit integers
7913 -- on targets with only 64-bit floats
7915 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
7916 -- Can this code be removed ???
7918 if Do_Range_Check (Operand) then
7920 Make_Type_Conversion (Loc,
7922 New_Occurrence_Of (Universal_Real, Loc),
7924 Relocate_Node (Operand)));
7926 Set_Etype (Operand, Universal_Real);
7927 Enable_Range_Check (Operand);
7928 Set_Do_Range_Check (Expression (Operand), False);
7931 -- Case of array conversions
7933 -- Expansion of array conversions, add required length/range checks but
7934 -- only do this if there is no change of representation. For handling of
7935 -- this case, see Handle_Changed_Representation.
7937 elsif Is_Array_Type (Target_Type) then
7939 if Is_Constrained (Target_Type) then
7940 Apply_Length_Check (Operand, Target_Type);
7942 Apply_Range_Check (Operand, Target_Type);
7945 Handle_Changed_Representation;
7947 -- Case of conversions of discriminated types
7949 -- Add required discriminant checks if target is constrained. Again this
7950 -- change is skipped if we have a change of representation.
7952 elsif Has_Discriminants (Target_Type)
7953 and then Is_Constrained (Target_Type)
7955 Apply_Discriminant_Check (Operand, Target_Type);
7956 Handle_Changed_Representation;
7958 -- Case of all other record conversions. The only processing required
7959 -- is to check for a change of representation requiring the special
7960 -- assignment processing.
7962 elsif Is_Record_Type (Target_Type) then
7964 -- Ada 2005 (AI-216): Program_Error is raised when converting from
7965 -- a derived Unchecked_Union type to an unconstrained type that is
7966 -- not Unchecked_Union if the operand lacks inferable discriminants.
7968 if Is_Derived_Type (Operand_Type)
7969 and then Is_Unchecked_Union (Base_Type (Operand_Type))
7970 and then not Is_Constrained (Target_Type)
7971 and then not Is_Unchecked_Union (Base_Type (Target_Type))
7972 and then not Has_Inferable_Discriminants (Operand)
7974 -- To prevent Gigi from generating illegal code, we generate a
7975 -- Program_Error node, but we give it the target type of the
7979 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
7980 Reason => PE_Unchecked_Union_Restriction);
7983 Set_Etype (PE, Target_Type);
7988 Handle_Changed_Representation;
7991 -- Case of conversions of enumeration types
7993 elsif Is_Enumeration_Type (Target_Type) then
7995 -- Special processing is required if there is a change of
7996 -- representation (from enumeration representation clauses)
7998 if not Same_Representation (Target_Type, Operand_Type) then
8000 -- Convert: x(y) to x'val (ytyp'val (y))
8003 Make_Attribute_Reference (Loc,
8004 Prefix => New_Occurrence_Of (Target_Type, Loc),
8005 Attribute_Name => Name_Val,
8006 Expressions => New_List (
8007 Make_Attribute_Reference (Loc,
8008 Prefix => New_Occurrence_Of (Operand_Type, Loc),
8009 Attribute_Name => Name_Pos,
8010 Expressions => New_List (Operand)))));
8012 Analyze_And_Resolve (N, Target_Type);
8015 -- Case of conversions to floating-point
8017 elsif Is_Floating_Point_Type (Target_Type) then
8021 -- At this stage, either the conversion node has been transformed into
8022 -- some other equivalent expression, or left as a conversion that can
8023 -- be handled by Gigi. The conversions that Gigi can handle are the
8026 -- Conversions with no change of representation or type
8028 -- Numeric conversions involving integer, floating- and fixed-point
8029 -- values. Fixed-point values are allowed only if Conversion_OK is
8030 -- set, i.e. if the fixed-point values are to be treated as integers.
8032 -- No other conversions should be passed to Gigi
8034 -- Check: are these rules stated in sinfo??? if so, why restate here???
8036 -- The only remaining step is to generate a range check if we still have
8037 -- a type conversion at this stage and Do_Range_Check is set. For now we
8038 -- do this only for conversions of discrete types.
8040 if Nkind (N) = N_Type_Conversion
8041 and then Is_Discrete_Type (Etype (N))
8044 Expr : constant Node_Id := Expression (N);
8049 if Do_Range_Check (Expr)
8050 and then Is_Discrete_Type (Etype (Expr))
8052 Set_Do_Range_Check (Expr, False);
8054 -- Before we do a range check, we have to deal with treating a
8055 -- fixed-point operand as an integer. The way we do this is
8056 -- simply to do an unchecked conversion to an appropriate
8057 -- integer type large enough to hold the result.
8059 -- This code is not active yet, because we are only dealing
8060 -- with discrete types so far ???
8062 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
8063 and then Treat_Fixed_As_Integer (Expr)
8065 Ftyp := Base_Type (Etype (Expr));
8067 if Esize (Ftyp) >= Esize (Standard_Integer) then
8068 Ityp := Standard_Long_Long_Integer;
8070 Ityp := Standard_Integer;
8073 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
8076 -- Reset overflow flag, since the range check will include
8077 -- dealing with possible overflow, and generate the check If
8078 -- Address is either a source type or target type, suppress
8079 -- range check to avoid typing anomalies when it is a visible
8082 Set_Do_Overflow_Check (N, False);
8083 if not Is_Descendent_Of_Address (Etype (Expr))
8084 and then not Is_Descendent_Of_Address (Target_Type)
8086 Generate_Range_Check
8087 (Expr, Target_Type, CE_Range_Check_Failed);
8093 -- Final step, if the result is a type conversion involving Vax_Float
8094 -- types, then it is subject for further special processing.
8096 if Nkind (N) = N_Type_Conversion
8097 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
8099 Expand_Vax_Conversion (N);
8102 end Expand_N_Type_Conversion;
8104 -----------------------------------
8105 -- Expand_N_Unchecked_Expression --
8106 -----------------------------------
8108 -- Remove the unchecked expression node from the tree. It's job was simply
8109 -- to make sure that its constituent expression was handled with checks
8110 -- off, and now that that is done, we can remove it from the tree, and
8111 -- indeed must, since gigi does not expect to see these nodes.
8113 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
8114 Exp : constant Node_Id := Expression (N);
8117 Set_Assignment_OK (Exp, Assignment_OK (N) or Assignment_OK (Exp));
8119 end Expand_N_Unchecked_Expression;
8121 ----------------------------------------
8122 -- Expand_N_Unchecked_Type_Conversion --
8123 ----------------------------------------
8125 -- If this cannot be handled by Gigi and we haven't already made a
8126 -- temporary for it, do it now.
8128 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
8129 Target_Type : constant Entity_Id := Etype (N);
8130 Operand : constant Node_Id := Expression (N);
8131 Operand_Type : constant Entity_Id := Etype (Operand);
8134 -- If we have a conversion of a compile time known value to a target
8135 -- type and the value is in range of the target type, then we can simply
8136 -- replace the construct by an integer literal of the correct type. We
8137 -- only apply this to integer types being converted. Possibly it may
8138 -- apply in other cases, but it is too much trouble to worry about.
8140 -- Note that we do not do this transformation if the Kill_Range_Check
8141 -- flag is set, since then the value may be outside the expected range.
8142 -- This happens in the Normalize_Scalars case.
8144 -- We also skip this if either the target or operand type is biased
8145 -- because in this case, the unchecked conversion is supposed to
8146 -- preserve the bit pattern, not the integer value.
8148 if Is_Integer_Type (Target_Type)
8149 and then not Has_Biased_Representation (Target_Type)
8150 and then Is_Integer_Type (Operand_Type)
8151 and then not Has_Biased_Representation (Operand_Type)
8152 and then Compile_Time_Known_Value (Operand)
8153 and then not Kill_Range_Check (N)
8156 Val : constant Uint := Expr_Value (Operand);
8159 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
8161 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
8163 Val >= Expr_Value (Type_Low_Bound (Target_Type))
8165 Val <= Expr_Value (Type_High_Bound (Target_Type))
8167 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
8169 -- If Address is the target type, just set the type to avoid a
8170 -- spurious type error on the literal when Address is a visible
8173 if Is_Descendent_Of_Address (Target_Type) then
8174 Set_Etype (N, Target_Type);
8176 Analyze_And_Resolve (N, Target_Type);
8184 -- Nothing to do if conversion is safe
8186 if Safe_Unchecked_Type_Conversion (N) then
8190 -- Otherwise force evaluation unless Assignment_OK flag is set (this
8191 -- flag indicates ??? -- more comments needed here)
8193 if Assignment_OK (N) then
8196 Force_Evaluation (N);
8198 end Expand_N_Unchecked_Type_Conversion;
8200 ----------------------------
8201 -- Expand_Record_Equality --
8202 ----------------------------
8204 -- For non-variant records, Equality is expanded when needed into:
8206 -- and then Lhs.Discr1 = Rhs.Discr1
8208 -- and then Lhs.Discrn = Rhs.Discrn
8209 -- and then Lhs.Cmp1 = Rhs.Cmp1
8211 -- and then Lhs.Cmpn = Rhs.Cmpn
8213 -- The expression is folded by the back-end for adjacent fields. This
8214 -- function is called for tagged record in only one occasion: for imple-
8215 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
8216 -- otherwise the primitive "=" is used directly.
8218 function Expand_Record_Equality
8223 Bodies : List_Id) return Node_Id
8225 Loc : constant Source_Ptr := Sloc (Nod);
8230 First_Time : Boolean := True;
8232 function Suitable_Element (C : Entity_Id) return Entity_Id;
8233 -- Return the first field to compare beginning with C, skipping the
8234 -- inherited components.
8236 ----------------------
8237 -- Suitable_Element --
8238 ----------------------
8240 function Suitable_Element (C : Entity_Id) return Entity_Id is
8245 elsif Ekind (C) /= E_Discriminant
8246 and then Ekind (C) /= E_Component
8248 return Suitable_Element (Next_Entity (C));
8250 elsif Is_Tagged_Type (Typ)
8251 and then C /= Original_Record_Component (C)
8253 return Suitable_Element (Next_Entity (C));
8255 elsif Chars (C) = Name_uController
8256 or else Chars (C) = Name_uTag
8258 return Suitable_Element (Next_Entity (C));
8260 elsif Is_Interface (Etype (C)) then
8261 return Suitable_Element (Next_Entity (C));
8266 end Suitable_Element;
8268 -- Start of processing for Expand_Record_Equality
8271 -- Generates the following code: (assuming that Typ has one Discr and
8272 -- component C2 is also a record)
8275 -- and then Lhs.Discr1 = Rhs.Discr1
8276 -- and then Lhs.C1 = Rhs.C1
8277 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
8279 -- and then Lhs.Cmpn = Rhs.Cmpn
8281 Result := New_Reference_To (Standard_True, Loc);
8282 C := Suitable_Element (First_Entity (Typ));
8284 while Present (C) loop
8292 First_Time := False;
8296 New_Lhs := New_Copy_Tree (Lhs);
8297 New_Rhs := New_Copy_Tree (Rhs);
8301 Expand_Composite_Equality (Nod, Etype (C),
8303 Make_Selected_Component (Loc,
8305 Selector_Name => New_Reference_To (C, Loc)),
8307 Make_Selected_Component (Loc,
8309 Selector_Name => New_Reference_To (C, Loc)),
8312 -- If some (sub)component is an unchecked_union, the whole
8313 -- operation will raise program error.
8315 if Nkind (Check) = N_Raise_Program_Error then
8317 Set_Etype (Result, Standard_Boolean);
8322 Left_Opnd => Result,
8323 Right_Opnd => Check);
8327 C := Suitable_Element (Next_Entity (C));
8331 end Expand_Record_Equality;
8333 -------------------------------------
8334 -- Fixup_Universal_Fixed_Operation --
8335 -------------------------------------
8337 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
8338 Conv : constant Node_Id := Parent (N);
8341 -- We must have a type conversion immediately above us
8343 pragma Assert (Nkind (Conv) = N_Type_Conversion);
8345 -- Normally the type conversion gives our target type. The exception
8346 -- occurs in the case of the Round attribute, where the conversion
8347 -- will be to universal real, and our real type comes from the Round
8348 -- attribute (as well as an indication that we must round the result)
8350 if Nkind (Parent (Conv)) = N_Attribute_Reference
8351 and then Attribute_Name (Parent (Conv)) = Name_Round
8353 Set_Etype (N, Etype (Parent (Conv)));
8354 Set_Rounded_Result (N);
8356 -- Normal case where type comes from conversion above us
8359 Set_Etype (N, Etype (Conv));
8361 end Fixup_Universal_Fixed_Operation;
8363 ------------------------------
8364 -- Get_Allocator_Final_List --
8365 ------------------------------
8367 function Get_Allocator_Final_List
8370 PtrT : Entity_Id) return Entity_Id
8372 Loc : constant Source_Ptr := Sloc (N);
8374 Owner : Entity_Id := PtrT;
8375 -- The entity whose finalization list must be used to attach the
8376 -- allocated object.
8379 if Ekind (PtrT) = E_Anonymous_Access_Type then
8381 -- If the context is an access parameter, we need to create a
8382 -- non-anonymous access type in order to have a usable final list,
8383 -- because there is otherwise no pool to which the allocated object
8384 -- can belong. We create both the type and the finalization chain
8385 -- here, because freezing an internal type does not create such a
8386 -- chain. The Final_Chain that is thus created is shared by the
8387 -- access parameter. The access type is tested against the result
8388 -- type of the function to exclude allocators whose type is an
8389 -- anonymous access result type. We freeze the type at once to
8390 -- ensure that it is properly decorated for the back-end, even
8391 -- if the context and current scope is a loop.
8393 if Nkind (Associated_Node_For_Itype (PtrT))
8394 in N_Subprogram_Specification
8397 Etype (Defining_Unit_Name (Associated_Node_For_Itype (PtrT)))
8399 Owner := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
8401 Make_Full_Type_Declaration (Loc,
8402 Defining_Identifier => Owner,
8404 Make_Access_To_Object_Definition (Loc,
8405 Subtype_Indication =>
8406 New_Occurrence_Of (T, Loc))));
8408 Freeze_Before (N, Owner);
8409 Build_Final_List (N, Owner);
8410 Set_Associated_Final_Chain (PtrT, Associated_Final_Chain (Owner));
8412 -- Ada 2005 (AI-318-02): If the context is a return object
8413 -- declaration, then the anonymous return subtype is defined to have
8414 -- the same accessibility level as that of the function's result
8415 -- subtype, which means that we want the scope where the function is
8418 elsif Nkind (Associated_Node_For_Itype (PtrT)) = N_Object_Declaration
8419 and then Ekind (Scope (PtrT)) = E_Return_Statement
8421 Owner := Scope (Return_Applies_To (Scope (PtrT)));
8423 -- Case of an access discriminant, or (Ada 2005), of an anonymous
8424 -- access component or anonymous access function result: find the
8425 -- final list associated with the scope of the type. (In the
8426 -- anonymous access component kind, a list controller will have
8427 -- been allocated when freezing the record type, and PtrT has an
8428 -- Associated_Final_Chain attribute designating it.)
8430 elsif No (Associated_Final_Chain (PtrT)) then
8431 Owner := Scope (PtrT);
8435 return Find_Final_List (Owner);
8436 end Get_Allocator_Final_List;
8438 ---------------------------------
8439 -- Has_Inferable_Discriminants --
8440 ---------------------------------
8442 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
8444 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
8445 -- Determines whether the left-most prefix of a selected component is a
8446 -- formal parameter in a subprogram. Assumes N is a selected component.
8448 --------------------------------
8449 -- Prefix_Is_Formal_Parameter --
8450 --------------------------------
8452 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
8453 Sel_Comp : Node_Id := N;
8456 -- Move to the left-most prefix by climbing up the tree
8458 while Present (Parent (Sel_Comp))
8459 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
8461 Sel_Comp := Parent (Sel_Comp);
8464 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
8465 end Prefix_Is_Formal_Parameter;
8467 -- Start of processing for Has_Inferable_Discriminants
8470 -- For identifiers and indexed components, it is sufficient to have a
8471 -- constrained Unchecked_Union nominal subtype.
8473 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
8474 return Is_Unchecked_Union (Base_Type (Etype (N)))
8476 Is_Constrained (Etype (N));
8478 -- For selected components, the subtype of the selector must be a
8479 -- constrained Unchecked_Union. If the component is subject to a
8480 -- per-object constraint, then the enclosing object must have inferable
8483 elsif Nkind (N) = N_Selected_Component then
8484 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
8486 -- A small hack. If we have a per-object constrained selected
8487 -- component of a formal parameter, return True since we do not
8488 -- know the actual parameter association yet.
8490 if Prefix_Is_Formal_Parameter (N) then
8494 -- Otherwise, check the enclosing object and the selector
8496 return Has_Inferable_Discriminants (Prefix (N))
8498 Has_Inferable_Discriminants (Selector_Name (N));
8501 -- The call to Has_Inferable_Discriminants will determine whether
8502 -- the selector has a constrained Unchecked_Union nominal type.
8504 return Has_Inferable_Discriminants (Selector_Name (N));
8506 -- A qualified expression has inferable discriminants if its subtype
8507 -- mark is a constrained Unchecked_Union subtype.
8509 elsif Nkind (N) = N_Qualified_Expression then
8510 return Is_Unchecked_Union (Subtype_Mark (N))
8512 Is_Constrained (Subtype_Mark (N));
8517 end Has_Inferable_Discriminants;
8519 -------------------------------
8520 -- Insert_Dereference_Action --
8521 -------------------------------
8523 procedure Insert_Dereference_Action (N : Node_Id) is
8524 Loc : constant Source_Ptr := Sloc (N);
8525 Typ : constant Entity_Id := Etype (N);
8526 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
8527 Pnod : constant Node_Id := Parent (N);
8529 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
8530 -- Return true if type of P is derived from Checked_Pool;
8532 -----------------------------
8533 -- Is_Checked_Storage_Pool --
8534 -----------------------------
8536 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
8545 while T /= Etype (T) loop
8546 if Is_RTE (T, RE_Checked_Pool) then
8554 end Is_Checked_Storage_Pool;
8556 -- Start of processing for Insert_Dereference_Action
8559 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
8561 if not (Is_Checked_Storage_Pool (Pool)
8562 and then Comes_From_Source (Original_Node (Pnod)))
8568 Make_Procedure_Call_Statement (Loc,
8569 Name => New_Reference_To (
8570 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
8572 Parameter_Associations => New_List (
8576 New_Reference_To (Pool, Loc),
8578 -- Storage_Address. We use the attribute Pool_Address, which uses
8579 -- the pointer itself to find the address of the object, and which
8580 -- handles unconstrained arrays properly by computing the address
8581 -- of the template. i.e. the correct address of the corresponding
8584 Make_Attribute_Reference (Loc,
8585 Prefix => Duplicate_Subexpr_Move_Checks (N),
8586 Attribute_Name => Name_Pool_Address),
8588 -- Size_In_Storage_Elements
8590 Make_Op_Divide (Loc,
8592 Make_Attribute_Reference (Loc,
8594 Make_Explicit_Dereference (Loc,
8595 Duplicate_Subexpr_Move_Checks (N)),
8596 Attribute_Name => Name_Size),
8598 Make_Integer_Literal (Loc, System_Storage_Unit)),
8602 Make_Attribute_Reference (Loc,
8604 Make_Explicit_Dereference (Loc,
8605 Duplicate_Subexpr_Move_Checks (N)),
8606 Attribute_Name => Name_Alignment))));
8609 when RE_Not_Available =>
8611 end Insert_Dereference_Action;
8613 ------------------------------
8614 -- Make_Array_Comparison_Op --
8615 ------------------------------
8617 -- This is a hand-coded expansion of the following generic function:
8620 -- type elem is (<>);
8621 -- type index is (<>);
8622 -- type a is array (index range <>) of elem;
8624 -- function Gnnn (X : a; Y: a) return boolean is
8625 -- J : index := Y'first;
8628 -- if X'length = 0 then
8631 -- elsif Y'length = 0 then
8635 -- for I in X'range loop
8636 -- if X (I) = Y (J) then
8637 -- if J = Y'last then
8640 -- J := index'succ (J);
8644 -- return X (I) > Y (J);
8648 -- return X'length > Y'length;
8652 -- Note that since we are essentially doing this expansion by hand, we
8653 -- do not need to generate an actual or formal generic part, just the
8654 -- instantiated function itself.
8656 function Make_Array_Comparison_Op
8658 Nod : Node_Id) return Node_Id
8660 Loc : constant Source_Ptr := Sloc (Nod);
8662 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
8663 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
8664 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
8665 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
8667 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
8669 Loop_Statement : Node_Id;
8670 Loop_Body : Node_Id;
8673 Final_Expr : Node_Id;
8674 Func_Body : Node_Id;
8675 Func_Name : Entity_Id;
8681 -- if J = Y'last then
8684 -- J := index'succ (J);
8688 Make_Implicit_If_Statement (Nod,
8691 Left_Opnd => New_Reference_To (J, Loc),
8693 Make_Attribute_Reference (Loc,
8694 Prefix => New_Reference_To (Y, Loc),
8695 Attribute_Name => Name_Last)),
8697 Then_Statements => New_List (
8698 Make_Exit_Statement (Loc)),
8702 Make_Assignment_Statement (Loc,
8703 Name => New_Reference_To (J, Loc),
8705 Make_Attribute_Reference (Loc,
8706 Prefix => New_Reference_To (Index, Loc),
8707 Attribute_Name => Name_Succ,
8708 Expressions => New_List (New_Reference_To (J, Loc))))));
8710 -- if X (I) = Y (J) then
8713 -- return X (I) > Y (J);
8717 Make_Implicit_If_Statement (Nod,
8721 Make_Indexed_Component (Loc,
8722 Prefix => New_Reference_To (X, Loc),
8723 Expressions => New_List (New_Reference_To (I, Loc))),
8726 Make_Indexed_Component (Loc,
8727 Prefix => New_Reference_To (Y, Loc),
8728 Expressions => New_List (New_Reference_To (J, Loc)))),
8730 Then_Statements => New_List (Inner_If),
8732 Else_Statements => New_List (
8733 Make_Simple_Return_Statement (Loc,
8737 Make_Indexed_Component (Loc,
8738 Prefix => New_Reference_To (X, Loc),
8739 Expressions => New_List (New_Reference_To (I, Loc))),
8742 Make_Indexed_Component (Loc,
8743 Prefix => New_Reference_To (Y, Loc),
8744 Expressions => New_List (
8745 New_Reference_To (J, Loc)))))));
8747 -- for I in X'range loop
8752 Make_Implicit_Loop_Statement (Nod,
8753 Identifier => Empty,
8756 Make_Iteration_Scheme (Loc,
8757 Loop_Parameter_Specification =>
8758 Make_Loop_Parameter_Specification (Loc,
8759 Defining_Identifier => I,
8760 Discrete_Subtype_Definition =>
8761 Make_Attribute_Reference (Loc,
8762 Prefix => New_Reference_To (X, Loc),
8763 Attribute_Name => Name_Range))),
8765 Statements => New_List (Loop_Body));
8767 -- if X'length = 0 then
8769 -- elsif Y'length = 0 then
8772 -- for ... loop ... end loop;
8773 -- return X'length > Y'length;
8777 Make_Attribute_Reference (Loc,
8778 Prefix => New_Reference_To (X, Loc),
8779 Attribute_Name => Name_Length);
8782 Make_Attribute_Reference (Loc,
8783 Prefix => New_Reference_To (Y, Loc),
8784 Attribute_Name => Name_Length);
8788 Left_Opnd => Length1,
8789 Right_Opnd => Length2);
8792 Make_Implicit_If_Statement (Nod,
8796 Make_Attribute_Reference (Loc,
8797 Prefix => New_Reference_To (X, Loc),
8798 Attribute_Name => Name_Length),
8800 Make_Integer_Literal (Loc, 0)),
8804 Make_Simple_Return_Statement (Loc,
8805 Expression => New_Reference_To (Standard_False, Loc))),
8807 Elsif_Parts => New_List (
8808 Make_Elsif_Part (Loc,
8812 Make_Attribute_Reference (Loc,
8813 Prefix => New_Reference_To (Y, Loc),
8814 Attribute_Name => Name_Length),
8816 Make_Integer_Literal (Loc, 0)),
8820 Make_Simple_Return_Statement (Loc,
8821 Expression => New_Reference_To (Standard_True, Loc))))),
8823 Else_Statements => New_List (
8825 Make_Simple_Return_Statement (Loc,
8826 Expression => Final_Expr)));
8830 Formals := New_List (
8831 Make_Parameter_Specification (Loc,
8832 Defining_Identifier => X,
8833 Parameter_Type => New_Reference_To (Typ, Loc)),
8835 Make_Parameter_Specification (Loc,
8836 Defining_Identifier => Y,
8837 Parameter_Type => New_Reference_To (Typ, Loc)));
8839 -- function Gnnn (...) return boolean is
8840 -- J : index := Y'first;
8845 Func_Name := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
8848 Make_Subprogram_Body (Loc,
8850 Make_Function_Specification (Loc,
8851 Defining_Unit_Name => Func_Name,
8852 Parameter_Specifications => Formals,
8853 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
8855 Declarations => New_List (
8856 Make_Object_Declaration (Loc,
8857 Defining_Identifier => J,
8858 Object_Definition => New_Reference_To (Index, Loc),
8860 Make_Attribute_Reference (Loc,
8861 Prefix => New_Reference_To (Y, Loc),
8862 Attribute_Name => Name_First))),
8864 Handled_Statement_Sequence =>
8865 Make_Handled_Sequence_Of_Statements (Loc,
8866 Statements => New_List (If_Stat)));
8869 end Make_Array_Comparison_Op;
8871 ---------------------------
8872 -- Make_Boolean_Array_Op --
8873 ---------------------------
8875 -- For logical operations on boolean arrays, expand in line the following,
8876 -- replacing 'and' with 'or' or 'xor' where needed:
8878 -- function Annn (A : typ; B: typ) return typ is
8881 -- for J in A'range loop
8882 -- C (J) := A (J) op B (J);
8887 -- Here typ is the boolean array type
8889 function Make_Boolean_Array_Op
8891 N : Node_Id) return Node_Id
8893 Loc : constant Source_Ptr := Sloc (N);
8895 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
8896 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
8897 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
8898 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
8906 Func_Name : Entity_Id;
8907 Func_Body : Node_Id;
8908 Loop_Statement : Node_Id;
8912 Make_Indexed_Component (Loc,
8913 Prefix => New_Reference_To (A, Loc),
8914 Expressions => New_List (New_Reference_To (J, Loc)));
8917 Make_Indexed_Component (Loc,
8918 Prefix => New_Reference_To (B, Loc),
8919 Expressions => New_List (New_Reference_To (J, Loc)));
8922 Make_Indexed_Component (Loc,
8923 Prefix => New_Reference_To (C, Loc),
8924 Expressions => New_List (New_Reference_To (J, Loc)));
8926 if Nkind (N) = N_Op_And then
8932 elsif Nkind (N) = N_Op_Or then
8946 Make_Implicit_Loop_Statement (N,
8947 Identifier => Empty,
8950 Make_Iteration_Scheme (Loc,
8951 Loop_Parameter_Specification =>
8952 Make_Loop_Parameter_Specification (Loc,
8953 Defining_Identifier => J,
8954 Discrete_Subtype_Definition =>
8955 Make_Attribute_Reference (Loc,
8956 Prefix => New_Reference_To (A, Loc),
8957 Attribute_Name => Name_Range))),
8959 Statements => New_List (
8960 Make_Assignment_Statement (Loc,
8962 Expression => Op)));
8964 Formals := New_List (
8965 Make_Parameter_Specification (Loc,
8966 Defining_Identifier => A,
8967 Parameter_Type => New_Reference_To (Typ, Loc)),
8969 Make_Parameter_Specification (Loc,
8970 Defining_Identifier => B,
8971 Parameter_Type => New_Reference_To (Typ, Loc)));
8974 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
8975 Set_Is_Inlined (Func_Name);
8978 Make_Subprogram_Body (Loc,
8980 Make_Function_Specification (Loc,
8981 Defining_Unit_Name => Func_Name,
8982 Parameter_Specifications => Formals,
8983 Result_Definition => New_Reference_To (Typ, Loc)),
8985 Declarations => New_List (
8986 Make_Object_Declaration (Loc,
8987 Defining_Identifier => C,
8988 Object_Definition => New_Reference_To (Typ, Loc))),
8990 Handled_Statement_Sequence =>
8991 Make_Handled_Sequence_Of_Statements (Loc,
8992 Statements => New_List (
8994 Make_Simple_Return_Statement (Loc,
8995 Expression => New_Reference_To (C, Loc)))));
8998 end Make_Boolean_Array_Op;
9000 ------------------------
9001 -- Rewrite_Comparison --
9002 ------------------------
9004 procedure Rewrite_Comparison (N : Node_Id) is
9005 Warning_Generated : Boolean := False;
9006 -- Set to True if first pass with Assume_Valid generates a warning in
9007 -- which case we skip the second pass to avoid warning overloaded.
9010 -- Set to Standard_True or Standard_False
9013 if Nkind (N) = N_Type_Conversion then
9014 Rewrite_Comparison (Expression (N));
9017 elsif Nkind (N) not in N_Op_Compare then
9021 -- Now start looking at the comparison in detail. We potentially go
9022 -- through this loop twice. The first time, Assume_Valid is set False
9023 -- in the call to Compile_Time_Compare. If this call results in a
9024 -- clear result of always True or Always False, that's decisive and
9025 -- we are done. Otherwise we repeat the processing with Assume_Valid
9026 -- set to True to generate additional warnings. We can stil that step
9027 -- if Constant_Condition_Warnings is False.
9029 for AV in False .. True loop
9031 Typ : constant Entity_Id := Etype (N);
9032 Op1 : constant Node_Id := Left_Opnd (N);
9033 Op2 : constant Node_Id := Right_Opnd (N);
9035 Res : constant Compare_Result :=
9036 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
9037 -- Res indicates if compare outcome can be compile time determined
9039 True_Result : Boolean;
9040 False_Result : Boolean;
9043 case N_Op_Compare (Nkind (N)) is
9045 True_Result := Res = EQ;
9046 False_Result := Res = LT or else Res = GT or else Res = NE;
9049 True_Result := Res in Compare_GE;
9050 False_Result := Res = LT;
9053 and then Constant_Condition_Warnings
9054 and then Comes_From_Source (Original_Node (N))
9055 and then Nkind (Original_Node (N)) = N_Op_Ge
9056 and then not In_Instance
9057 and then Is_Integer_Type (Etype (Left_Opnd (N)))
9058 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
9061 ("can never be greater than, could replace by ""'=""?", N);
9062 Warning_Generated := True;
9066 True_Result := Res = GT;
9067 False_Result := Res in Compare_LE;
9070 True_Result := Res = LT;
9071 False_Result := Res in Compare_GE;
9074 True_Result := Res in Compare_LE;
9075 False_Result := Res = GT;
9078 and then Constant_Condition_Warnings
9079 and then Comes_From_Source (Original_Node (N))
9080 and then Nkind (Original_Node (N)) = N_Op_Le
9081 and then not In_Instance
9082 and then Is_Integer_Type (Etype (Left_Opnd (N)))
9083 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
9086 ("can never be less than, could replace by ""'=""?", N);
9087 Warning_Generated := True;
9091 True_Result := Res = NE or else Res = GT or else Res = LT;
9092 False_Result := Res = EQ;
9095 -- If this is the first iteration, then we actually convert the
9096 -- comparison into True or False, if the result is certain.
9099 if True_Result or False_Result then
9101 Result := Standard_True;
9103 Result := Standard_False;
9108 New_Occurrence_Of (Result, Sloc (N))));
9109 Analyze_And_Resolve (N, Typ);
9110 Warn_On_Known_Condition (N);
9114 -- If this is the second iteration (AV = True), and the original
9115 -- node comes from source and we are not in an instance, then
9116 -- give a warning if we know result would be True or False. Note
9117 -- we know Constant_Condition_Warnings is set if we get here.
9119 elsif Comes_From_Source (Original_Node (N))
9120 and then not In_Instance
9124 ("condition can only be False if invalid values present?",
9126 elsif False_Result then
9128 ("condition can only be True if invalid values present?",
9134 -- Skip second iteration if not warning on constant conditions or
9135 -- if the first iteration already generated a warning of some kind
9136 -- or if we are in any case assuming all values are valid (so that
9137 -- the first iteration took care of the valid case).
9139 exit when not Constant_Condition_Warnings;
9140 exit when Warning_Generated;
9141 exit when Assume_No_Invalid_Values;
9143 end Rewrite_Comparison;
9145 ----------------------------
9146 -- Safe_In_Place_Array_Op --
9147 ----------------------------
9149 function Safe_In_Place_Array_Op
9152 Op2 : Node_Id) return Boolean
9156 function Is_Safe_Operand (Op : Node_Id) return Boolean;
9157 -- Operand is safe if it cannot overlap part of the target of the
9158 -- operation. If the operand and the target are identical, the operand
9159 -- is safe. The operand can be empty in the case of negation.
9161 function Is_Unaliased (N : Node_Id) return Boolean;
9162 -- Check that N is a stand-alone entity
9168 function Is_Unaliased (N : Node_Id) return Boolean is
9172 and then No (Address_Clause (Entity (N)))
9173 and then No (Renamed_Object (Entity (N)));
9176 ---------------------
9177 -- Is_Safe_Operand --
9178 ---------------------
9180 function Is_Safe_Operand (Op : Node_Id) return Boolean is
9185 elsif Is_Entity_Name (Op) then
9186 return Is_Unaliased (Op);
9188 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
9189 return Is_Unaliased (Prefix (Op));
9191 elsif Nkind (Op) = N_Slice then
9193 Is_Unaliased (Prefix (Op))
9194 and then Entity (Prefix (Op)) /= Target;
9196 elsif Nkind (Op) = N_Op_Not then
9197 return Is_Safe_Operand (Right_Opnd (Op));
9202 end Is_Safe_Operand;
9204 -- Start of processing for Is_Safe_In_Place_Array_Op
9207 -- Skip this processing if the component size is different from system
9208 -- storage unit (since at least for NOT this would cause problems).
9210 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
9213 -- Cannot do in place stuff on VM_Target since cannot pass addresses
9215 elsif VM_Target /= No_VM then
9218 -- Cannot do in place stuff if non-standard Boolean representation
9220 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
9223 elsif not Is_Unaliased (Lhs) then
9226 Target := Entity (Lhs);
9229 Is_Safe_Operand (Op1)
9230 and then Is_Safe_Operand (Op2);
9232 end Safe_In_Place_Array_Op;
9234 -----------------------
9235 -- Tagged_Membership --
9236 -----------------------
9238 -- There are two different cases to consider depending on whether the right
9239 -- operand is a class-wide type or not. If not we just compare the actual
9240 -- tag of the left expr to the target type tag:
9242 -- Left_Expr.Tag = Right_Type'Tag;
9244 -- If it is a class-wide type we use the RT function CW_Membership which is
9245 -- usually implemented by looking in the ancestor tables contained in the
9246 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
9248 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
9249 -- function IW_Membership which is usually implemented by looking in the
9250 -- table of abstract interface types plus the ancestor table contained in
9251 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
9253 function Tagged_Membership (N : Node_Id) return Node_Id is
9254 Left : constant Node_Id := Left_Opnd (N);
9255 Right : constant Node_Id := Right_Opnd (N);
9256 Loc : constant Source_Ptr := Sloc (N);
9258 Left_Type : Entity_Id;
9259 Right_Type : Entity_Id;
9263 Left_Type := Etype (Left);
9264 Right_Type := Etype (Right);
9266 if Is_Class_Wide_Type (Left_Type) then
9267 Left_Type := Root_Type (Left_Type);
9271 Make_Selected_Component (Loc,
9272 Prefix => Relocate_Node (Left),
9274 New_Reference_To (First_Tag_Component (Left_Type), Loc));
9276 if Is_Class_Wide_Type (Right_Type) then
9278 -- No need to issue a run-time check if we statically know that the
9279 -- result of this membership test is always true. For example,
9280 -- considering the following declarations:
9282 -- type Iface is interface;
9283 -- type T is tagged null record;
9284 -- type DT is new T and Iface with null record;
9289 -- These membership tests are always true:
9293 -- Obj2 in Iface'Class;
9295 -- We do not need to handle cases where the membership is illegal.
9298 -- Obj1 in DT'Class; -- Compile time error
9299 -- Obj1 in Iface'Class; -- Compile time error
9301 if not Is_Class_Wide_Type (Left_Type)
9302 and then (Is_Ancestor (Etype (Right_Type), Left_Type)
9303 or else (Is_Interface (Etype (Right_Type))
9304 and then Interface_Present_In_Ancestor
9306 Iface => Etype (Right_Type))))
9308 return New_Reference_To (Standard_True, Loc);
9311 -- Ada 2005 (AI-251): Class-wide applied to interfaces
9313 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
9315 -- Support to: "Iface_CW_Typ in Typ'Class"
9317 or else Is_Interface (Left_Type)
9319 -- Issue error if IW_Membership operation not available in a
9320 -- configurable run time setting.
9322 if not RTE_Available (RE_IW_Membership) then
9324 ("dynamic membership test on interface types", N);
9329 Make_Function_Call (Loc,
9330 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
9331 Parameter_Associations => New_List (
9332 Make_Attribute_Reference (Loc,
9334 Attribute_Name => Name_Address),
9337 (Access_Disp_Table (Root_Type (Right_Type)))),
9340 -- Ada 95: Normal case
9344 Build_CW_Membership (Loc,
9345 Obj_Tag_Node => Obj_Tag,
9349 (Access_Disp_Table (Root_Type (Right_Type)))),
9353 -- Right_Type is not a class-wide type
9356 -- No need to check the tag of the object if Right_Typ is abstract
9358 if Is_Abstract_Type (Right_Type) then
9359 return New_Reference_To (Standard_False, Loc);
9364 Left_Opnd => Obj_Tag,
9367 (Node (First_Elmt (Access_Disp_Table (Right_Type))), Loc));
9370 end Tagged_Membership;
9372 ------------------------------
9373 -- Unary_Op_Validity_Checks --
9374 ------------------------------
9376 procedure Unary_Op_Validity_Checks (N : Node_Id) is
9378 if Validity_Checks_On and Validity_Check_Operands then
9379 Ensure_Valid (Right_Opnd (N));
9381 end Unary_Op_Validity_Checks;
OSDN Git Service
