1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Aggr; use Exp_Aggr;
33 with Exp_Atag; use Exp_Atag;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Fixd; use Exp_Fixd;
40 with Exp_Intr; use Exp_Intr;
41 with Exp_Pakd; use Exp_Pakd;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Exp_VFpt; use Exp_VFpt;
45 with Freeze; use Freeze;
46 with Inline; use Inline;
48 with Namet; use Namet;
49 with Nlists; use Nlists;
50 with Nmake; use Nmake;
52 with Par_SCO; use Par_SCO;
53 with Restrict; use Restrict;
54 with Rident; use Rident;
55 with Rtsfind; use Rtsfind;
57 with Sem_Aux; use Sem_Aux;
58 with Sem_Cat; use Sem_Cat;
59 with Sem_Ch3; use Sem_Ch3;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Type; use Sem_Type;
64 with Sem_Util; use Sem_Util;
65 with Sem_Warn; use Sem_Warn;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Stand; use Stand;
69 with SCIL_LL; use SCIL_LL;
70 with Targparm; use Targparm;
71 with Tbuild; use Tbuild;
72 with Ttypes; use Ttypes;
73 with Uintp; use Uintp;
74 with Urealp; use Urealp;
75 with Validsw; use Validsw;
77 package body Exp_Ch4 is
79 -----------------------
80 -- Local Subprograms --
81 -----------------------
83 procedure Binary_Op_Validity_Checks (N : Node_Id);
84 pragma Inline (Binary_Op_Validity_Checks);
85 -- Performs validity checks for a binary operator
87 procedure Build_Boolean_Array_Proc_Call
91 -- If a boolean array assignment can be done in place, build call to
92 -- corresponding library procedure.
94 procedure Complete_Controlled_Allocation (Temp_Decl : Node_Id);
95 -- Subsidiary to Expand_N_Allocator and Expand_Allocator_Expression. Formal
96 -- Temp_Decl is the declaration of a temporary which hold the value of the
97 -- original allocator. Create a custom Allocate routine for the expression
98 -- of Temp_Decl. The routine does special processing for anonymous access
101 procedure Displace_Allocator_Pointer (N : Node_Id);
102 -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
103 -- Expand_Allocator_Expression. Allocating class-wide interface objects
104 -- this routine displaces the pointer to the allocated object to reference
105 -- the component referencing the corresponding secondary dispatch table.
107 procedure Expand_Allocator_Expression (N : Node_Id);
108 -- Subsidiary to Expand_N_Allocator, for the case when the expression
109 -- is a qualified expression or an aggregate.
111 procedure Expand_Array_Comparison (N : Node_Id);
112 -- This routine handles expansion of the comparison operators (N_Op_Lt,
113 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
114 -- code for these operators is similar, differing only in the details of
115 -- the actual comparison call that is made. Special processing (call a
118 function Expand_Array_Equality
123 Typ : Entity_Id) return Node_Id;
124 -- Expand an array equality into a call to a function implementing this
125 -- equality, and a call to it. Loc is the location for the generated nodes.
126 -- Lhs and Rhs are the array expressions to be compared. Bodies is a list
127 -- on which to attach bodies of local functions that are created in the
128 -- process. It is the responsibility of the caller to insert those bodies
129 -- at the right place. Nod provides the Sloc value for the generated code.
130 -- Normally the types used for the generated equality routine are taken
131 -- from Lhs and Rhs. However, in some situations of generated code, the
132 -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
133 -- the type to be used for the formal parameters.
135 procedure Expand_Boolean_Operator (N : Node_Id);
136 -- Common expansion processing for Boolean operators (And, Or, Xor) for the
137 -- case of array type arguments.
139 procedure Expand_Short_Circuit_Operator (N : Node_Id);
140 -- Common expansion processing for short-circuit boolean operators
142 function Expand_Composite_Equality
147 Bodies : List_Id) return Node_Id;
148 -- Local recursive function used to expand equality for nested composite
149 -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
150 -- to attach bodies of local functions that are created in the process.
151 -- This is the responsibility of the caller to insert those bodies at the
152 -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs
153 -- are the left and right sides for the comparison, and Typ is the type of
154 -- the arrays to compare.
156 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id);
157 -- Routine to expand concatenation of a sequence of two or more operands
158 -- (in the list Operands) and replace node Cnode with the result of the
159 -- concatenation. The operands can be of any appropriate type, and can
160 -- include both arrays and singleton elements.
162 procedure Fixup_Universal_Fixed_Operation (N : Node_Id);
163 -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
164 -- fixed. We do not have such a type at runtime, so the purpose of this
165 -- routine is to find the real type by looking up the tree. We also
166 -- determine if the operation must be rounded.
168 function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
169 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
170 -- discriminants if it has a constrained nominal type, unless the object
171 -- is a component of an enclosing Unchecked_Union object that is subject
172 -- to a per-object constraint and the enclosing object lacks inferable
175 -- An expression of an Unchecked_Union type has inferable discriminants
176 -- if it is either a name of an object with inferable discriminants or a
177 -- qualified expression whose subtype mark denotes a constrained subtype.
179 procedure Insert_Dereference_Action (N : Node_Id);
180 -- N is an expression whose type is an access. When the type of the
181 -- associated storage pool is derived from Checked_Pool, generate a
182 -- call to the 'Dereference' primitive operation.
184 function Make_Array_Comparison_Op
186 Nod : Node_Id) return Node_Id;
187 -- Comparisons between arrays are expanded in line. This function produces
188 -- the body of the implementation of (a > b), where a and b are one-
189 -- dimensional arrays of some discrete type. The original node is then
190 -- expanded into the appropriate call to this function. Nod provides the
191 -- Sloc value for the generated code.
193 function Make_Boolean_Array_Op
195 N : Node_Id) return Node_Id;
196 -- Boolean operations on boolean arrays are expanded in line. This function
197 -- produce the body for the node N, which is (a and b), (a or b), or (a xor
198 -- b). It is used only the normal case and not the packed case. The type
199 -- involved, Typ, is the Boolean array type, and the logical operations in
200 -- the body are simple boolean operations. Note that Typ is always a
201 -- constrained type (the caller has ensured this by using
202 -- Convert_To_Actual_Subtype if necessary).
204 procedure Optimize_Length_Comparison (N : Node_Id);
205 -- Given an expression, if it is of the form X'Length op N (or the other
206 -- way round), where N is known at compile time to be 0 or 1, and X is a
207 -- simple entity, and op is a comparison operator, optimizes it into a
208 -- comparison of First and Last.
210 procedure Rewrite_Comparison (N : Node_Id);
211 -- If N is the node for a comparison whose outcome can be determined at
212 -- compile time, then the node N can be rewritten with True or False. If
213 -- the outcome cannot be determined at compile time, the call has no
214 -- effect. If N is a type conversion, then this processing is applied to
215 -- its expression. If N is neither comparison nor a type conversion, the
216 -- call has no effect.
218 procedure Tagged_Membership
220 SCIL_Node : out Node_Id;
221 Result : out Node_Id);
222 -- Construct the expression corresponding to the tagged membership test.
223 -- Deals with a second operand being (or not) a class-wide type.
225 function Safe_In_Place_Array_Op
228 Op2 : Node_Id) return Boolean;
229 -- In the context of an assignment, where the right-hand side is a boolean
230 -- operation on arrays, check whether operation can be performed in place.
232 procedure Unary_Op_Validity_Checks (N : Node_Id);
233 pragma Inline (Unary_Op_Validity_Checks);
234 -- Performs validity checks for a unary operator
236 -------------------------------
237 -- Binary_Op_Validity_Checks --
238 -------------------------------
240 procedure Binary_Op_Validity_Checks (N : Node_Id) is
242 if Validity_Checks_On and Validity_Check_Operands then
243 Ensure_Valid (Left_Opnd (N));
244 Ensure_Valid (Right_Opnd (N));
246 end Binary_Op_Validity_Checks;
248 ------------------------------------
249 -- Build_Boolean_Array_Proc_Call --
250 ------------------------------------
252 procedure Build_Boolean_Array_Proc_Call
257 Loc : constant Source_Ptr := Sloc (N);
258 Kind : constant Node_Kind := Nkind (Expression (N));
259 Target : constant Node_Id :=
260 Make_Attribute_Reference (Loc,
262 Attribute_Name => Name_Address);
264 Arg1 : Node_Id := Op1;
265 Arg2 : Node_Id := Op2;
267 Proc_Name : Entity_Id;
270 if Kind = N_Op_Not then
271 if Nkind (Op1) in N_Binary_Op then
273 -- Use negated version of the binary operators
275 if Nkind (Op1) = N_Op_And then
276 Proc_Name := RTE (RE_Vector_Nand);
278 elsif Nkind (Op1) = N_Op_Or then
279 Proc_Name := RTE (RE_Vector_Nor);
281 else pragma Assert (Nkind (Op1) = N_Op_Xor);
282 Proc_Name := RTE (RE_Vector_Xor);
286 Make_Procedure_Call_Statement (Loc,
287 Name => New_Occurrence_Of (Proc_Name, Loc),
289 Parameter_Associations => New_List (
291 Make_Attribute_Reference (Loc,
292 Prefix => Left_Opnd (Op1),
293 Attribute_Name => Name_Address),
295 Make_Attribute_Reference (Loc,
296 Prefix => Right_Opnd (Op1),
297 Attribute_Name => Name_Address),
299 Make_Attribute_Reference (Loc,
300 Prefix => Left_Opnd (Op1),
301 Attribute_Name => Name_Length)));
304 Proc_Name := RTE (RE_Vector_Not);
307 Make_Procedure_Call_Statement (Loc,
308 Name => New_Occurrence_Of (Proc_Name, Loc),
309 Parameter_Associations => New_List (
312 Make_Attribute_Reference (Loc,
314 Attribute_Name => Name_Address),
316 Make_Attribute_Reference (Loc,
318 Attribute_Name => Name_Length)));
322 -- We use the following equivalences:
324 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
325 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
326 -- (not X) xor (not Y) = X xor Y
327 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
329 if Nkind (Op1) = N_Op_Not then
330 Arg1 := Right_Opnd (Op1);
331 Arg2 := Right_Opnd (Op2);
332 if Kind = N_Op_And then
333 Proc_Name := RTE (RE_Vector_Nor);
334 elsif Kind = N_Op_Or then
335 Proc_Name := RTE (RE_Vector_Nand);
337 Proc_Name := RTE (RE_Vector_Xor);
341 if Kind = N_Op_And then
342 Proc_Name := RTE (RE_Vector_And);
343 elsif Kind = N_Op_Or then
344 Proc_Name := RTE (RE_Vector_Or);
345 elsif Nkind (Op2) = N_Op_Not then
346 Proc_Name := RTE (RE_Vector_Nxor);
347 Arg2 := Right_Opnd (Op2);
349 Proc_Name := RTE (RE_Vector_Xor);
354 Make_Procedure_Call_Statement (Loc,
355 Name => New_Occurrence_Of (Proc_Name, Loc),
356 Parameter_Associations => New_List (
358 Make_Attribute_Reference (Loc,
360 Attribute_Name => Name_Address),
361 Make_Attribute_Reference (Loc,
363 Attribute_Name => Name_Address),
364 Make_Attribute_Reference (Loc,
366 Attribute_Name => Name_Length)));
369 Rewrite (N, Call_Node);
373 when RE_Not_Available =>
375 end Build_Boolean_Array_Proc_Call;
377 ------------------------------------
378 -- Complete_Controlled_Allocation --
379 ------------------------------------
381 procedure Complete_Controlled_Allocation (Temp_Decl : Node_Id) is
382 pragma Assert (Nkind (Temp_Decl) = N_Object_Declaration);
384 Ptr_Typ : constant Entity_Id := Etype (Defining_Identifier (Temp_Decl));
386 function First_Declaration_Of_Current_Unit return Node_Id;
387 -- Return the current unit's first declaration. If the declaration list
388 -- is empty, the routine generates a null statement and returns it.
390 ---------------------------------------
391 -- First_Declaration_Of_Current_Unit --
392 ---------------------------------------
394 function First_Declaration_Of_Current_Unit return Node_Id is
395 Sem_U : Node_Id := Unit (Cunit (Current_Sem_Unit));
400 if Nkind (Sem_U) = N_Package_Declaration then
401 Sem_U := Specification (Sem_U);
402 Decls := Visible_Declarations (Sem_U);
405 Decl := Make_Null_Statement (Sloc (Sem_U));
406 Decls := New_List (Decl);
407 Set_Visible_Declarations (Sem_U, Decls);
409 Decl := First (Decls);
413 Decls := Declarations (Sem_U);
416 Decl := Make_Null_Statement (Sloc (Sem_U));
417 Decls := New_List (Decl);
418 Set_Declarations (Sem_U, Decls);
420 Decl := First (Decls);
425 end First_Declaration_Of_Current_Unit;
427 -- Start of processing for Complete_Controlled_Allocation
430 -- Certain run-time configurations and targets do not provide support
431 -- for controlled types.
433 if Restriction_Active (No_Finalization) then
436 -- Do nothing if the access type may never allocate an object
438 elsif No_Pool_Assigned (Ptr_Typ) then
441 -- Access-to-controlled types are not supported on .NET/JVM
443 elsif VM_Target /= No_VM then
447 -- Processing for anonymous access-to-controlled types. These access
448 -- types receive a special collection which appears on the declarations
449 -- of the enclosing semantic unit.
451 if Ekind (Ptr_Typ) = E_Anonymous_Access_Type
452 and then No (Associated_Collection (Ptr_Typ))
454 (not Restriction_Active (No_Nested_Finalization)
455 or else Is_Library_Level_Entity (Ptr_Typ))
458 Pool_Id : constant Entity_Id :=
459 Get_Global_Pool_For_Access_Type (Ptr_Typ);
460 Scop : Node_Id := Cunit_Entity (Current_Sem_Unit);
463 -- Use the scope of the current semantic unit when analyzing
465 if Ekind (Scop) = E_Subprogram_Body then
466 Scop := Corresponding_Spec (Parent (Parent (Parent (Scop))));
469 Build_Finalization_Collection
471 Ins_Node => First_Declaration_Of_Current_Unit,
474 -- Decorate the anonymous access type and the allocator node
476 Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
477 Set_Storage_Pool (Expression (Temp_Decl), Pool_Id);
481 -- Since the temporary object reuses the original allocator, generate a
482 -- custom Allocate routine for the temporary.
484 if Present (Associated_Collection (Ptr_Typ)) then
485 Build_Allocate_Deallocate_Proc
487 Is_Allocate => True);
489 end Complete_Controlled_Allocation;
491 --------------------------------
492 -- Displace_Allocator_Pointer --
493 --------------------------------
495 procedure Displace_Allocator_Pointer (N : Node_Id) is
496 Loc : constant Source_Ptr := Sloc (N);
497 Orig_Node : constant Node_Id := Original_Node (N);
503 -- Do nothing in case of VM targets: the virtual machine will handle
504 -- interfaces directly.
506 if not Tagged_Type_Expansion then
510 pragma Assert (Nkind (N) = N_Identifier
511 and then Nkind (Orig_Node) = N_Allocator);
513 PtrT := Etype (Orig_Node);
514 Dtyp := Available_View (Designated_Type (PtrT));
515 Etyp := Etype (Expression (Orig_Node));
517 if Is_Class_Wide_Type (Dtyp)
518 and then Is_Interface (Dtyp)
520 -- If the type of the allocator expression is not an interface type
521 -- we can generate code to reference the record component containing
522 -- the pointer to the secondary dispatch table.
524 if not Is_Interface (Etyp) then
526 Saved_Typ : constant Entity_Id := Etype (Orig_Node);
529 -- 1) Get access to the allocated object
532 Make_Explicit_Dereference (Loc,
537 -- 2) Add the conversion to displace the pointer to reference
538 -- the secondary dispatch table.
540 Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
541 Analyze_And_Resolve (N, Dtyp);
543 -- 3) The 'access to the secondary dispatch table will be used
544 -- as the value returned by the allocator.
547 Make_Attribute_Reference (Loc,
548 Prefix => Relocate_Node (N),
549 Attribute_Name => Name_Access));
550 Set_Etype (N, Saved_Typ);
554 -- If the type of the allocator expression is an interface type we
555 -- generate a run-time call to displace "this" to reference the
556 -- component containing the pointer to the secondary dispatch table
557 -- or else raise Constraint_Error if the actual object does not
558 -- implement the target interface. This case corresponds with the
559 -- following example:
561 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
563 -- return new Iface_2'Class'(Obj);
568 Unchecked_Convert_To (PtrT,
569 Make_Function_Call (Loc,
570 Name => New_Reference_To (RTE (RE_Displace), Loc),
571 Parameter_Associations => New_List (
572 Unchecked_Convert_To (RTE (RE_Address),
578 (Access_Disp_Table (Etype (Base_Type (Dtyp))))),
580 Analyze_And_Resolve (N, PtrT);
583 end Displace_Allocator_Pointer;
585 ---------------------------------
586 -- Expand_Allocator_Expression --
587 ---------------------------------
589 procedure Expand_Allocator_Expression (N : Node_Id) is
590 Loc : constant Source_Ptr := Sloc (N);
591 Exp : constant Node_Id := Expression (Expression (N));
592 PtrT : constant Entity_Id := Etype (N);
593 DesigT : constant Entity_Id := Designated_Type (PtrT);
595 procedure Apply_Accessibility_Check
597 Built_In_Place : Boolean := False);
598 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
599 -- type, generate an accessibility check to verify that the level of the
600 -- type of the created object is not deeper than the level of the access
601 -- type. If the type of the qualified expression is class- wide, then
602 -- always generate the check (except in the case where it is known to be
603 -- unnecessary, see comment below). Otherwise, only generate the check
604 -- if the level of the qualified expression type is statically deeper
605 -- than the access type.
607 -- Although the static accessibility will generally have been performed
608 -- as a legality check, it won't have been done in cases where the
609 -- allocator appears in generic body, so a run-time check is needed in
610 -- general. One special case is when the access type is declared in the
611 -- same scope as the class-wide allocator, in which case the check can
612 -- never fail, so it need not be generated.
614 -- As an open issue, there seem to be cases where the static level
615 -- associated with the class-wide object's underlying type is not
616 -- sufficient to perform the proper accessibility check, such as for
617 -- allocators in nested subprograms or accept statements initialized by
618 -- class-wide formals when the actual originates outside at a deeper
619 -- static level. The nested subprogram case might require passing
620 -- accessibility levels along with class-wide parameters, and the task
621 -- case seems to be an actual gap in the language rules that needs to
622 -- be fixed by the ARG. ???
624 -------------------------------
625 -- Apply_Accessibility_Check --
626 -------------------------------
628 procedure Apply_Accessibility_Check
630 Built_In_Place : Boolean := False)
635 if Ada_Version >= Ada_2005
636 and then Is_Class_Wide_Type (DesigT)
637 and then not Scope_Suppress (Accessibility_Check)
639 (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
641 (Is_Class_Wide_Type (Etype (Exp))
642 and then Scope (PtrT) /= Current_Scope))
644 -- If the allocator was built in place Ref is already a reference
645 -- to the access object initialized to the result of the allocator
646 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise
647 -- it is the entity associated with the object containing the
648 -- address of the allocated object.
650 if Built_In_Place then
651 New_Node := New_Copy (Ref);
653 New_Node := New_Reference_To (Ref, Loc);
657 Make_Attribute_Reference (Loc,
659 Attribute_Name => Name_Tag);
661 if Tagged_Type_Expansion then
662 New_Node := Build_Get_Access_Level (Loc, New_Node);
664 elsif VM_Target /= No_VM then
666 Make_Function_Call (Loc,
667 Name => New_Reference_To (RTE (RE_Get_Access_Level), Loc),
668 Parameter_Associations => New_List (New_Node));
670 -- Cannot generate the runtime check
677 Make_Raise_Program_Error (Loc,
680 Left_Opnd => New_Node,
682 Make_Integer_Literal (Loc, Type_Access_Level (PtrT))),
683 Reason => PE_Accessibility_Check_Failed));
685 end Apply_Accessibility_Check;
689 Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
690 Indic : constant Node_Id := Subtype_Mark (Expression (N));
691 T : constant Entity_Id := Entity (Indic);
693 Tag_Assign : Node_Id;
697 TagT : Entity_Id := Empty;
698 -- Type used as source for tag assignment
700 TagR : Node_Id := Empty;
701 -- Target reference for tag assignment
703 -- Start of processing for Expand_Allocator_Expression
706 if Is_Tagged_Type (T)
707 or else Needs_Finalization (T)
709 if Is_CPP_Constructor_Call (Exp) then
712 -- Pnnn : constant ptr_T := new (T);
713 -- Init (Pnnn.all,...);
715 -- Allocate the object without an expression
717 Node := Relocate_Node (N);
718 Set_Expression (Node, New_Reference_To (Etype (Exp), Loc));
720 -- Avoid its expansion to avoid generating a call to the default
725 Temp := Make_Temporary (Loc, 'P', N);
728 Make_Object_Declaration (Loc,
729 Defining_Identifier => Temp,
730 Constant_Present => True,
731 Object_Definition => New_Reference_To (PtrT, Loc),
733 Insert_Action (N, Temp_Decl);
735 Apply_Accessibility_Check (Temp);
737 -- Locate the enclosing list and insert the C++ constructor call
744 while not Is_List_Member (P) loop
748 Insert_List_After_And_Analyze (P,
749 Build_Initialization_Call (Loc,
751 Make_Explicit_Dereference (Loc,
752 Prefix => New_Reference_To (Temp, Loc)),
754 Constructor_Ref => Exp));
757 Rewrite (N, New_Reference_To (Temp, Loc));
758 Analyze_And_Resolve (N, PtrT);
762 -- Ada 2005 (AI-318-02): If the initialization expression is a call
763 -- to a build-in-place function, then access to the allocated object
764 -- must be passed to the function. Currently we limit such functions
765 -- to those with constrained limited result subtypes, but eventually
766 -- we plan to expand the allowed forms of functions that are treated
767 -- as build-in-place.
769 if Ada_Version >= Ada_2005
770 and then Is_Build_In_Place_Function_Call (Exp)
772 Make_Build_In_Place_Call_In_Allocator (N, Exp);
773 Apply_Accessibility_Check (N, Built_In_Place => True);
777 -- Actions inserted before:
778 -- Temp : constant ptr_T := new T'(Expression);
779 -- <no CW> Temp._tag := T'tag;
780 -- <CTRL> Adjust (Finalizable (Temp.all));
781 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
783 -- We analyze by hand the new internal allocator to avoid
784 -- any recursion and inappropriate call to Initialize
786 -- We don't want to remove side effects when the expression must be
787 -- built in place. In the case of a build-in-place function call,
788 -- that could lead to a duplication of the call, which was already
789 -- substituted for the allocator.
791 if not Aggr_In_Place then
792 Remove_Side_Effects (Exp);
795 Temp := Make_Temporary (Loc, 'P', N);
797 -- For a class wide allocation generate the following code:
799 -- type Equiv_Record is record ... end record;
800 -- implicit subtype CW is <Class_Wide_Subytpe>;
801 -- temp : PtrT := new CW'(CW!(expr));
803 if Is_Class_Wide_Type (T) then
804 Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
806 -- Ada 2005 (AI-251): If the expression is a class-wide interface
807 -- object we generate code to move up "this" to reference the
808 -- base of the object before allocating the new object.
810 -- Note that Exp'Address is recursively expanded into a call
811 -- to Base_Address (Exp.Tag)
813 if Is_Class_Wide_Type (Etype (Exp))
814 and then Is_Interface (Etype (Exp))
815 and then Tagged_Type_Expansion
819 Unchecked_Convert_To (Entity (Indic),
820 Make_Explicit_Dereference (Loc,
821 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
822 Make_Attribute_Reference (Loc,
824 Attribute_Name => Name_Address)))));
828 Unchecked_Convert_To (Entity (Indic), Exp));
831 Analyze_And_Resolve (Expression (N), Entity (Indic));
834 -- Processing for allocators returning non-interface types
836 if not Is_Interface (Directly_Designated_Type (PtrT)) then
837 if Aggr_In_Place then
839 Make_Object_Declaration (Loc,
840 Defining_Identifier => Temp,
841 Object_Definition => New_Reference_To (PtrT, Loc),
845 New_Reference_To (Etype (Exp), Loc)));
847 -- Copy the Comes_From_Source flag for the allocator we just
848 -- built, since logically this allocator is a replacement of
849 -- the original allocator node. This is for proper handling of
850 -- restriction No_Implicit_Heap_Allocations.
852 Set_Comes_From_Source
853 (Expression (Temp_Decl), Comes_From_Source (N));
855 Set_No_Initialization (Expression (Temp_Decl));
856 Insert_Action (N, Temp_Decl);
858 Complete_Controlled_Allocation (Temp_Decl);
859 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
861 -- Attach the object to the associated finalization collection.
862 -- This is done manually on .NET/JVM since those compilers do
863 -- no support pools and can't benefit from internally generated
864 -- Allocate / Deallocate procedures.
866 if VM_Target /= No_VM
867 and then Is_Controlled (DesigT)
868 and then Present (Associated_Collection (PtrT))
873 New_Reference_To (Temp, Loc),
878 Node := Relocate_Node (N);
882 Make_Object_Declaration (Loc,
883 Defining_Identifier => Temp,
884 Constant_Present => True,
885 Object_Definition => New_Reference_To (PtrT, Loc),
888 Insert_Action (N, Temp_Decl);
889 Complete_Controlled_Allocation (Temp_Decl);
891 -- Attach the object to the associated finalization collection.
892 -- This is done manually on .NET/JVM since those compilers do
893 -- no support pools and can't benefit from internally generated
894 -- Allocate / Deallocate procedures.
896 if VM_Target /= No_VM
897 and then Is_Controlled (DesigT)
898 and then Present (Associated_Collection (PtrT))
903 New_Reference_To (Temp, Loc),
908 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
909 -- interface type. In this case we use the type of the qualified
910 -- expression to allocate the object.
914 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
919 Make_Full_Type_Declaration (Loc,
920 Defining_Identifier => Def_Id,
922 Make_Access_To_Object_Definition (Loc,
924 Null_Exclusion_Present => False,
925 Constant_Present => False,
926 Subtype_Indication =>
927 New_Reference_To (Etype (Exp), Loc)));
929 Insert_Action (N, New_Decl);
931 -- Inherit the allocation-related attributes from the original
934 Set_Associated_Collection (Def_Id,
935 Associated_Collection (PtrT));
937 Set_Associated_Storage_Pool (Def_Id,
938 Associated_Storage_Pool (PtrT));
940 -- Declare the object using the previous type declaration
942 if Aggr_In_Place then
944 Make_Object_Declaration (Loc,
945 Defining_Identifier => Temp,
946 Object_Definition => New_Reference_To (Def_Id, Loc),
949 New_Reference_To (Etype (Exp), Loc)));
951 -- Copy the Comes_From_Source flag for the allocator we just
952 -- built, since logically this allocator is a replacement of
953 -- the original allocator node. This is for proper handling
954 -- of restriction No_Implicit_Heap_Allocations.
956 Set_Comes_From_Source
957 (Expression (Temp_Decl), Comes_From_Source (N));
959 Set_No_Initialization (Expression (Temp_Decl));
960 Insert_Action (N, Temp_Decl);
962 Complete_Controlled_Allocation (Temp_Decl);
963 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
966 Node := Relocate_Node (N);
970 Make_Object_Declaration (Loc,
971 Defining_Identifier => Temp,
972 Constant_Present => True,
973 Object_Definition => New_Reference_To (Def_Id, Loc),
976 Insert_Action (N, Temp_Decl);
977 Complete_Controlled_Allocation (Temp_Decl);
980 -- Generate an additional object containing the address of the
981 -- returned object. The type of this second object declaration
982 -- is the correct type required for the common processing that
983 -- is still performed by this subprogram. The displacement of
984 -- this pointer to reference the component associated with the
985 -- interface type will be done at the end of common processing.
988 Make_Object_Declaration (Loc,
989 Defining_Identifier => Make_Temporary (Loc, 'P'),
990 Object_Definition => New_Reference_To (PtrT, Loc),
992 Unchecked_Convert_To (PtrT,
993 New_Reference_To (Temp, Loc)));
995 Insert_Action (N, New_Decl);
997 Temp_Decl := New_Decl;
998 Temp := Defining_Identifier (New_Decl);
1002 Apply_Accessibility_Check (Temp);
1004 -- Generate the tag assignment
1006 -- Suppress the tag assignment when VM_Target because VM tags are
1007 -- represented implicitly in objects.
1009 if not Tagged_Type_Expansion then
1012 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
1013 -- interface objects because in this case the tag does not change.
1015 elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
1016 pragma Assert (Is_Class_Wide_Type
1017 (Directly_Designated_Type (Etype (N))));
1020 elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
1022 TagR := New_Reference_To (Temp, Loc);
1024 elsif Is_Private_Type (T)
1025 and then Is_Tagged_Type (Underlying_Type (T))
1027 TagT := Underlying_Type (T);
1029 Unchecked_Convert_To (Underlying_Type (T),
1030 Make_Explicit_Dereference (Loc,
1031 Prefix => New_Reference_To (Temp, Loc)));
1034 if Present (TagT) then
1036 Full_T : constant Entity_Id := Underlying_Type (TagT);
1039 Make_Assignment_Statement (Loc,
1041 Make_Selected_Component (Loc,
1044 New_Reference_To (First_Tag_Component (Full_T), Loc)),
1046 Unchecked_Convert_To (RTE (RE_Tag),
1049 (First_Elmt (Access_Disp_Table (Full_T))), Loc)));
1052 -- The previous assignment has to be done in any case
1054 Set_Assignment_OK (Name (Tag_Assign));
1055 Insert_Action (N, Tag_Assign);
1058 if Needs_Finalization (DesigT)
1059 and then Needs_Finalization (T)
1061 -- Generate an Adjust call if the object will be moved. In Ada
1062 -- 2005, the object may be inherently limited, in which case
1063 -- there is no Adjust procedure, and the object is built in
1064 -- place. In Ada 95, the object can be limited but not
1065 -- inherently limited if this allocator came from a return
1066 -- statement (we're allocating the result on the secondary
1067 -- stack). In that case, the object will be moved, so we _do_
1070 if not Aggr_In_Place
1071 and then not Is_Immutably_Limited_Type (T)
1077 -- An unchecked conversion is needed in the classwide
1078 -- case because the designated type can be an ancestor
1079 -- of the subtype mark of the allocator.
1081 Unchecked_Convert_To (T,
1082 Make_Explicit_Dereference (Loc,
1083 Prefix => New_Reference_To (Temp, Loc))),
1088 -- Set_Finalize_Address_Ptr
1089 -- (Collection, <Finalize_Address>'Unrestricted_Access)
1091 -- Since .NET/JVM compilers do not support address arithmetic,
1092 -- this call is skipped. The same is done for CodePeer because
1093 -- Finalize_Address is never generated.
1095 if VM_Target = No_VM
1096 and then not CodePeer_Mode
1097 and then Present (Associated_Collection (PtrT))
1100 Make_Set_Finalize_Address_Ptr_Call
1107 Rewrite (N, New_Reference_To (Temp, Loc));
1108 Analyze_And_Resolve (N, PtrT);
1110 -- Ada 2005 (AI-251): Displace the pointer to reference the record
1111 -- component containing the secondary dispatch table of the interface
1114 if Is_Interface (Directly_Designated_Type (PtrT)) then
1115 Displace_Allocator_Pointer (N);
1118 elsif Aggr_In_Place then
1119 Temp := Make_Temporary (Loc, 'P', N);
1121 Make_Object_Declaration (Loc,
1122 Defining_Identifier => Temp,
1123 Object_Definition => New_Reference_To (PtrT, Loc),
1125 Make_Allocator (Loc,
1126 Expression => New_Reference_To (Etype (Exp), Loc)));
1128 -- Copy the Comes_From_Source flag for the allocator we just built,
1129 -- since logically this allocator is a replacement of the original
1130 -- allocator node. This is for proper handling of restriction
1131 -- No_Implicit_Heap_Allocations.
1133 Set_Comes_From_Source
1134 (Expression (Temp_Decl), Comes_From_Source (N));
1136 Set_No_Initialization (Expression (Temp_Decl));
1137 Insert_Action (N, Temp_Decl);
1139 Complete_Controlled_Allocation (Temp_Decl);
1140 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
1142 -- Attach the object to the associated finalization collection. This
1143 -- is done manually on .NET/JVM since those compilers do no support
1144 -- pools and cannot benefit from internally generated Allocate and
1145 -- Deallocate procedures.
1147 if VM_Target /= No_VM
1148 and then Is_Controlled (DesigT)
1149 and then Present (Associated_Collection (PtrT))
1153 (Obj_Ref => New_Reference_To (Temp, Loc),
1157 Rewrite (N, New_Reference_To (Temp, Loc));
1158 Analyze_And_Resolve (N, PtrT);
1160 elsif Is_Access_Type (T)
1161 and then Can_Never_Be_Null (T)
1163 Install_Null_Excluding_Check (Exp);
1165 elsif Is_Access_Type (DesigT)
1166 and then Nkind (Exp) = N_Allocator
1167 and then Nkind (Expression (Exp)) /= N_Qualified_Expression
1169 -- Apply constraint to designated subtype indication
1171 Apply_Constraint_Check (Expression (Exp),
1172 Designated_Type (DesigT),
1173 No_Sliding => True);
1175 if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
1177 -- Propagate constraint_error to enclosing allocator
1179 Rewrite (Exp, New_Copy (Expression (Exp)));
1183 -- type A is access T1;
1184 -- X : A := new T2'(...);
1185 -- T1 and T2 can be different subtypes, and we might need to check
1186 -- both constraints. First check against the type of the qualified
1189 Apply_Constraint_Check (Exp, T, No_Sliding => True);
1191 if Do_Range_Check (Exp) then
1192 Set_Do_Range_Check (Exp, False);
1193 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1196 -- A check is also needed in cases where the designated subtype is
1197 -- constrained and differs from the subtype given in the qualified
1198 -- expression. Note that the check on the qualified expression does
1199 -- not allow sliding, but this check does (a relaxation from Ada 83).
1201 if Is_Constrained (DesigT)
1202 and then not Subtypes_Statically_Match (T, DesigT)
1204 Apply_Constraint_Check
1205 (Exp, DesigT, No_Sliding => False);
1207 if Do_Range_Check (Exp) then
1208 Set_Do_Range_Check (Exp, False);
1209 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1213 -- For an access to unconstrained packed array, GIGI needs to see an
1214 -- expression with a constrained subtype in order to compute the
1215 -- proper size for the allocator.
1217 if Is_Array_Type (T)
1218 and then not Is_Constrained (T)
1219 and then Is_Packed (T)
1222 ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A');
1223 Internal_Exp : constant Node_Id := Relocate_Node (Exp);
1226 Make_Subtype_Declaration (Loc,
1227 Defining_Identifier => ConstrT,
1228 Subtype_Indication => Make_Subtype_From_Expr (Exp, T)));
1229 Freeze_Itype (ConstrT, Exp);
1230 Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
1234 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1235 -- to a build-in-place function, then access to the allocated object
1236 -- must be passed to the function. Currently we limit such functions
1237 -- to those with constrained limited result subtypes, but eventually
1238 -- we plan to expand the allowed forms of functions that are treated
1239 -- as build-in-place.
1241 if Ada_Version >= Ada_2005
1242 and then Is_Build_In_Place_Function_Call (Exp)
1244 Make_Build_In_Place_Call_In_Allocator (N, Exp);
1249 when RE_Not_Available =>
1251 end Expand_Allocator_Expression;
1253 -----------------------------
1254 -- Expand_Array_Comparison --
1255 -----------------------------
1257 -- Expansion is only required in the case of array types. For the unpacked
1258 -- case, an appropriate runtime routine is called. For packed cases, and
1259 -- also in some other cases where a runtime routine cannot be called, the
1260 -- form of the expansion is:
1262 -- [body for greater_nn; boolean_expression]
1264 -- The body is built by Make_Array_Comparison_Op, and the form of the
1265 -- Boolean expression depends on the operator involved.
1267 procedure Expand_Array_Comparison (N : Node_Id) is
1268 Loc : constant Source_Ptr := Sloc (N);
1269 Op1 : Node_Id := Left_Opnd (N);
1270 Op2 : Node_Id := Right_Opnd (N);
1271 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
1272 Ctyp : constant Entity_Id := Component_Type (Typ1);
1275 Func_Body : Node_Id;
1276 Func_Name : Entity_Id;
1280 Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
1281 -- True for byte addressable target
1283 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
1284 -- Returns True if the length of the given operand is known to be less
1285 -- than 4. Returns False if this length is known to be four or greater
1286 -- or is not known at compile time.
1288 ------------------------
1289 -- Length_Less_Than_4 --
1290 ------------------------
1292 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
1293 Otyp : constant Entity_Id := Etype (Opnd);
1296 if Ekind (Otyp) = E_String_Literal_Subtype then
1297 return String_Literal_Length (Otyp) < 4;
1301 Ityp : constant Entity_Id := Etype (First_Index (Otyp));
1302 Lo : constant Node_Id := Type_Low_Bound (Ityp);
1303 Hi : constant Node_Id := Type_High_Bound (Ityp);
1308 if Compile_Time_Known_Value (Lo) then
1309 Lov := Expr_Value (Lo);
1314 if Compile_Time_Known_Value (Hi) then
1315 Hiv := Expr_Value (Hi);
1320 return Hiv < Lov + 3;
1323 end Length_Less_Than_4;
1325 -- Start of processing for Expand_Array_Comparison
1328 -- Deal first with unpacked case, where we can call a runtime routine
1329 -- except that we avoid this for targets for which are not addressable
1330 -- by bytes, and for the JVM/CIL, since they do not support direct
1331 -- addressing of array components.
1333 if not Is_Bit_Packed_Array (Typ1)
1334 and then Byte_Addressable
1335 and then VM_Target = No_VM
1337 -- The call we generate is:
1339 -- Compare_Array_xn[_Unaligned]
1340 -- (left'address, right'address, left'length, right'length) <op> 0
1342 -- x = U for unsigned, S for signed
1343 -- n = 8,16,32,64 for component size
1344 -- Add _Unaligned if length < 4 and component size is 8.
1345 -- <op> is the standard comparison operator
1347 if Component_Size (Typ1) = 8 then
1348 if Length_Less_Than_4 (Op1)
1350 Length_Less_Than_4 (Op2)
1352 if Is_Unsigned_Type (Ctyp) then
1353 Comp := RE_Compare_Array_U8_Unaligned;
1355 Comp := RE_Compare_Array_S8_Unaligned;
1359 if Is_Unsigned_Type (Ctyp) then
1360 Comp := RE_Compare_Array_U8;
1362 Comp := RE_Compare_Array_S8;
1366 elsif Component_Size (Typ1) = 16 then
1367 if Is_Unsigned_Type (Ctyp) then
1368 Comp := RE_Compare_Array_U16;
1370 Comp := RE_Compare_Array_S16;
1373 elsif Component_Size (Typ1) = 32 then
1374 if Is_Unsigned_Type (Ctyp) then
1375 Comp := RE_Compare_Array_U32;
1377 Comp := RE_Compare_Array_S32;
1380 else pragma Assert (Component_Size (Typ1) = 64);
1381 if Is_Unsigned_Type (Ctyp) then
1382 Comp := RE_Compare_Array_U64;
1384 Comp := RE_Compare_Array_S64;
1388 Remove_Side_Effects (Op1, Name_Req => True);
1389 Remove_Side_Effects (Op2, Name_Req => True);
1392 Make_Function_Call (Sloc (Op1),
1393 Name => New_Occurrence_Of (RTE (Comp), Loc),
1395 Parameter_Associations => New_List (
1396 Make_Attribute_Reference (Loc,
1397 Prefix => Relocate_Node (Op1),
1398 Attribute_Name => Name_Address),
1400 Make_Attribute_Reference (Loc,
1401 Prefix => Relocate_Node (Op2),
1402 Attribute_Name => Name_Address),
1404 Make_Attribute_Reference (Loc,
1405 Prefix => Relocate_Node (Op1),
1406 Attribute_Name => Name_Length),
1408 Make_Attribute_Reference (Loc,
1409 Prefix => Relocate_Node (Op2),
1410 Attribute_Name => Name_Length))));
1413 Make_Integer_Literal (Sloc (Op2),
1416 Analyze_And_Resolve (Op1, Standard_Integer);
1417 Analyze_And_Resolve (Op2, Standard_Integer);
1421 -- Cases where we cannot make runtime call
1423 -- For (a <= b) we convert to not (a > b)
1425 if Chars (N) = Name_Op_Le then
1431 Right_Opnd => Op2)));
1432 Analyze_And_Resolve (N, Standard_Boolean);
1435 -- For < the Boolean expression is
1436 -- greater__nn (op2, op1)
1438 elsif Chars (N) = Name_Op_Lt then
1439 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1443 Op1 := Right_Opnd (N);
1444 Op2 := Left_Opnd (N);
1446 -- For (a >= b) we convert to not (a < b)
1448 elsif Chars (N) = Name_Op_Ge then
1454 Right_Opnd => Op2)));
1455 Analyze_And_Resolve (N, Standard_Boolean);
1458 -- For > the Boolean expression is
1459 -- greater__nn (op1, op2)
1462 pragma Assert (Chars (N) = Name_Op_Gt);
1463 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1466 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1468 Make_Function_Call (Loc,
1469 Name => New_Reference_To (Func_Name, Loc),
1470 Parameter_Associations => New_List (Op1, Op2));
1472 Insert_Action (N, Func_Body);
1474 Analyze_And_Resolve (N, Standard_Boolean);
1477 when RE_Not_Available =>
1479 end Expand_Array_Comparison;
1481 ---------------------------
1482 -- Expand_Array_Equality --
1483 ---------------------------
1485 -- Expand an equality function for multi-dimensional arrays. Here is an
1486 -- example of such a function for Nb_Dimension = 2
1488 -- function Enn (A : atyp; B : btyp) return boolean is
1490 -- if (A'length (1) = 0 or else A'length (2) = 0)
1492 -- (B'length (1) = 0 or else B'length (2) = 0)
1494 -- return True; -- RM 4.5.2(22)
1497 -- if A'length (1) /= B'length (1)
1499 -- A'length (2) /= B'length (2)
1501 -- return False; -- RM 4.5.2(23)
1505 -- A1 : Index_T1 := A'first (1);
1506 -- B1 : Index_T1 := B'first (1);
1510 -- A2 : Index_T2 := A'first (2);
1511 -- B2 : Index_T2 := B'first (2);
1514 -- if A (A1, A2) /= B (B1, B2) then
1518 -- exit when A2 = A'last (2);
1519 -- A2 := Index_T2'succ (A2);
1520 -- B2 := Index_T2'succ (B2);
1524 -- exit when A1 = A'last (1);
1525 -- A1 := Index_T1'succ (A1);
1526 -- B1 := Index_T1'succ (B1);
1533 -- Note on the formal types used (atyp and btyp). If either of the arrays
1534 -- is of a private type, we use the underlying type, and do an unchecked
1535 -- conversion of the actual. If either of the arrays has a bound depending
1536 -- on a discriminant, then we use the base type since otherwise we have an
1537 -- escaped discriminant in the function.
1539 -- If both arrays are constrained and have the same bounds, we can generate
1540 -- a loop with an explicit iteration scheme using a 'Range attribute over
1543 function Expand_Array_Equality
1548 Typ : Entity_Id) return Node_Id
1550 Loc : constant Source_Ptr := Sloc (Nod);
1551 Decls : constant List_Id := New_List;
1552 Index_List1 : constant List_Id := New_List;
1553 Index_List2 : constant List_Id := New_List;
1557 Func_Name : Entity_Id;
1558 Func_Body : Node_Id;
1560 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
1561 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
1565 -- The parameter types to be used for the formals
1570 Num : Int) return Node_Id;
1571 -- This builds the attribute reference Arr'Nam (Expr)
1573 function Component_Equality (Typ : Entity_Id) return Node_Id;
1574 -- Create one statement to compare corresponding components, designated
1575 -- by a full set of indexes.
1577 function Get_Arg_Type (N : Node_Id) return Entity_Id;
1578 -- Given one of the arguments, computes the appropriate type to be used
1579 -- for that argument in the corresponding function formal
1581 function Handle_One_Dimension
1583 Index : Node_Id) return Node_Id;
1584 -- This procedure returns the following code
1587 -- Bn : Index_T := B'First (N);
1591 -- exit when An = A'Last (N);
1592 -- An := Index_T'Succ (An)
1593 -- Bn := Index_T'Succ (Bn)
1597 -- If both indexes are constrained and identical, the procedure
1598 -- returns a simpler loop:
1600 -- for An in A'Range (N) loop
1604 -- N is the dimension for which we are generating a loop. Index is the
1605 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1606 -- xxx statement is either the loop or declare for the next dimension
1607 -- or if this is the last dimension the comparison of corresponding
1608 -- components of the arrays.
1610 -- The actual way the code works is to return the comparison of
1611 -- corresponding components for the N+1 call. That's neater!
1613 function Test_Empty_Arrays return Node_Id;
1614 -- This function constructs the test for both arrays being empty
1615 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1617 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1619 function Test_Lengths_Correspond return Node_Id;
1620 -- This function constructs the test for arrays having different lengths
1621 -- in at least one index position, in which case the resulting code is:
1623 -- A'length (1) /= B'length (1)
1625 -- A'length (2) /= B'length (2)
1636 Num : Int) return Node_Id
1640 Make_Attribute_Reference (Loc,
1641 Attribute_Name => Nam,
1642 Prefix => New_Reference_To (Arr, Loc),
1643 Expressions => New_List (Make_Integer_Literal (Loc, Num)));
1646 ------------------------
1647 -- Component_Equality --
1648 ------------------------
1650 function Component_Equality (Typ : Entity_Id) return Node_Id is
1655 -- if a(i1...) /= b(j1...) then return false; end if;
1658 Make_Indexed_Component (Loc,
1659 Prefix => Make_Identifier (Loc, Chars (A)),
1660 Expressions => Index_List1);
1663 Make_Indexed_Component (Loc,
1664 Prefix => Make_Identifier (Loc, Chars (B)),
1665 Expressions => Index_List2);
1667 Test := Expand_Composite_Equality
1668 (Nod, Component_Type (Typ), L, R, Decls);
1670 -- If some (sub)component is an unchecked_union, the whole operation
1671 -- will raise program error.
1673 if Nkind (Test) = N_Raise_Program_Error then
1675 -- This node is going to be inserted at a location where a
1676 -- statement is expected: clear its Etype so analysis will set
1677 -- it to the expected Standard_Void_Type.
1679 Set_Etype (Test, Empty);
1684 Make_Implicit_If_Statement (Nod,
1685 Condition => Make_Op_Not (Loc, Right_Opnd => Test),
1686 Then_Statements => New_List (
1687 Make_Simple_Return_Statement (Loc,
1688 Expression => New_Occurrence_Of (Standard_False, Loc))));
1690 end Component_Equality;
1696 function Get_Arg_Type (N : Node_Id) return Entity_Id is
1707 T := Underlying_Type (T);
1709 X := First_Index (T);
1710 while Present (X) loop
1711 if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
1713 Denotes_Discriminant (Type_High_Bound (Etype (X)))
1726 --------------------------
1727 -- Handle_One_Dimension --
1728 ---------------------------
1730 function Handle_One_Dimension
1732 Index : Node_Id) return Node_Id
1734 Need_Separate_Indexes : constant Boolean :=
1736 or else not Is_Constrained (Ltyp);
1737 -- If the index types are identical, and we are working with
1738 -- constrained types, then we can use the same index for both
1741 An : constant Entity_Id := Make_Temporary (Loc, 'A');
1744 Index_T : Entity_Id;
1749 if N > Number_Dimensions (Ltyp) then
1750 return Component_Equality (Ltyp);
1753 -- Case where we generate a loop
1755 Index_T := Base_Type (Etype (Index));
1757 if Need_Separate_Indexes then
1758 Bn := Make_Temporary (Loc, 'B');
1763 Append (New_Reference_To (An, Loc), Index_List1);
1764 Append (New_Reference_To (Bn, Loc), Index_List2);
1766 Stm_List := New_List (
1767 Handle_One_Dimension (N + 1, Next_Index (Index)));
1769 if Need_Separate_Indexes then
1771 -- Generate guard for loop, followed by increments of indexes
1773 Append_To (Stm_List,
1774 Make_Exit_Statement (Loc,
1777 Left_Opnd => New_Reference_To (An, Loc),
1778 Right_Opnd => Arr_Attr (A, Name_Last, N))));
1780 Append_To (Stm_List,
1781 Make_Assignment_Statement (Loc,
1782 Name => New_Reference_To (An, Loc),
1784 Make_Attribute_Reference (Loc,
1785 Prefix => New_Reference_To (Index_T, Loc),
1786 Attribute_Name => Name_Succ,
1787 Expressions => New_List (New_Reference_To (An, Loc)))));
1789 Append_To (Stm_List,
1790 Make_Assignment_Statement (Loc,
1791 Name => New_Reference_To (Bn, Loc),
1793 Make_Attribute_Reference (Loc,
1794 Prefix => New_Reference_To (Index_T, Loc),
1795 Attribute_Name => Name_Succ,
1796 Expressions => New_List (New_Reference_To (Bn, Loc)))));
1799 -- If separate indexes, we need a declare block for An and Bn, and a
1800 -- loop without an iteration scheme.
1802 if Need_Separate_Indexes then
1804 Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
1807 Make_Block_Statement (Loc,
1808 Declarations => New_List (
1809 Make_Object_Declaration (Loc,
1810 Defining_Identifier => An,
1811 Object_Definition => New_Reference_To (Index_T, Loc),
1812 Expression => Arr_Attr (A, Name_First, N)),
1814 Make_Object_Declaration (Loc,
1815 Defining_Identifier => Bn,
1816 Object_Definition => New_Reference_To (Index_T, Loc),
1817 Expression => Arr_Attr (B, Name_First, N))),
1819 Handled_Statement_Sequence =>
1820 Make_Handled_Sequence_Of_Statements (Loc,
1821 Statements => New_List (Loop_Stm)));
1823 -- If no separate indexes, return loop statement with explicit
1824 -- iteration scheme on its own
1828 Make_Implicit_Loop_Statement (Nod,
1829 Statements => Stm_List,
1831 Make_Iteration_Scheme (Loc,
1832 Loop_Parameter_Specification =>
1833 Make_Loop_Parameter_Specification (Loc,
1834 Defining_Identifier => An,
1835 Discrete_Subtype_Definition =>
1836 Arr_Attr (A, Name_Range, N))));
1839 end Handle_One_Dimension;
1841 -----------------------
1842 -- Test_Empty_Arrays --
1843 -----------------------
1845 function Test_Empty_Arrays return Node_Id is
1855 for J in 1 .. Number_Dimensions (Ltyp) loop
1858 Left_Opnd => Arr_Attr (A, Name_Length, J),
1859 Right_Opnd => Make_Integer_Literal (Loc, 0));
1863 Left_Opnd => Arr_Attr (B, Name_Length, J),
1864 Right_Opnd => Make_Integer_Literal (Loc, 0));
1873 Left_Opnd => Relocate_Node (Alist),
1874 Right_Opnd => Atest);
1878 Left_Opnd => Relocate_Node (Blist),
1879 Right_Opnd => Btest);
1886 Right_Opnd => Blist);
1887 end Test_Empty_Arrays;
1889 -----------------------------
1890 -- Test_Lengths_Correspond --
1891 -----------------------------
1893 function Test_Lengths_Correspond return Node_Id is
1899 for J in 1 .. Number_Dimensions (Ltyp) loop
1902 Left_Opnd => Arr_Attr (A, Name_Length, J),
1903 Right_Opnd => Arr_Attr (B, Name_Length, J));
1910 Left_Opnd => Relocate_Node (Result),
1911 Right_Opnd => Rtest);
1916 end Test_Lengths_Correspond;
1918 -- Start of processing for Expand_Array_Equality
1921 Ltyp := Get_Arg_Type (Lhs);
1922 Rtyp := Get_Arg_Type (Rhs);
1924 -- For now, if the argument types are not the same, go to the base type,
1925 -- since the code assumes that the formals have the same type. This is
1926 -- fixable in future ???
1928 if Ltyp /= Rtyp then
1929 Ltyp := Base_Type (Ltyp);
1930 Rtyp := Base_Type (Rtyp);
1931 pragma Assert (Ltyp = Rtyp);
1934 -- Build list of formals for function
1936 Formals := New_List (
1937 Make_Parameter_Specification (Loc,
1938 Defining_Identifier => A,
1939 Parameter_Type => New_Reference_To (Ltyp, Loc)),
1941 Make_Parameter_Specification (Loc,
1942 Defining_Identifier => B,
1943 Parameter_Type => New_Reference_To (Rtyp, Loc)));
1945 Func_Name := Make_Temporary (Loc, 'E');
1947 -- Build statement sequence for function
1950 Make_Subprogram_Body (Loc,
1952 Make_Function_Specification (Loc,
1953 Defining_Unit_Name => Func_Name,
1954 Parameter_Specifications => Formals,
1955 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
1957 Declarations => Decls,
1959 Handled_Statement_Sequence =>
1960 Make_Handled_Sequence_Of_Statements (Loc,
1961 Statements => New_List (
1963 Make_Implicit_If_Statement (Nod,
1964 Condition => Test_Empty_Arrays,
1965 Then_Statements => New_List (
1966 Make_Simple_Return_Statement (Loc,
1968 New_Occurrence_Of (Standard_True, Loc)))),
1970 Make_Implicit_If_Statement (Nod,
1971 Condition => Test_Lengths_Correspond,
1972 Then_Statements => New_List (
1973 Make_Simple_Return_Statement (Loc,
1975 New_Occurrence_Of (Standard_False, Loc)))),
1977 Handle_One_Dimension (1, First_Index (Ltyp)),
1979 Make_Simple_Return_Statement (Loc,
1980 Expression => New_Occurrence_Of (Standard_True, Loc)))));
1982 Set_Has_Completion (Func_Name, True);
1983 Set_Is_Inlined (Func_Name);
1985 -- If the array type is distinct from the type of the arguments, it
1986 -- is the full view of a private type. Apply an unchecked conversion
1987 -- to insure that analysis of the call succeeds.
1997 or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
1999 L := OK_Convert_To (Ltyp, Lhs);
2003 or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
2005 R := OK_Convert_To (Rtyp, Rhs);
2008 Actuals := New_List (L, R);
2011 Append_To (Bodies, Func_Body);
2014 Make_Function_Call (Loc,
2015 Name => New_Reference_To (Func_Name, Loc),
2016 Parameter_Associations => Actuals);
2017 end Expand_Array_Equality;
2019 -----------------------------
2020 -- Expand_Boolean_Operator --
2021 -----------------------------
2023 -- Note that we first get the actual subtypes of the operands, since we
2024 -- always want to deal with types that have bounds.
2026 procedure Expand_Boolean_Operator (N : Node_Id) is
2027 Typ : constant Entity_Id := Etype (N);
2030 -- Special case of bit packed array where both operands are known to be
2031 -- properly aligned. In this case we use an efficient run time routine
2032 -- to carry out the operation (see System.Bit_Ops).
2034 if Is_Bit_Packed_Array (Typ)
2035 and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
2036 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
2038 Expand_Packed_Boolean_Operator (N);
2042 -- For the normal non-packed case, the general expansion is to build
2043 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
2044 -- and then inserting it into the tree. The original operator node is
2045 -- then rewritten as a call to this function. We also use this in the
2046 -- packed case if either operand is a possibly unaligned object.
2049 Loc : constant Source_Ptr := Sloc (N);
2050 L : constant Node_Id := Relocate_Node (Left_Opnd (N));
2051 R : constant Node_Id := Relocate_Node (Right_Opnd (N));
2052 Func_Body : Node_Id;
2053 Func_Name : Entity_Id;
2056 Convert_To_Actual_Subtype (L);
2057 Convert_To_Actual_Subtype (R);
2058 Ensure_Defined (Etype (L), N);
2059 Ensure_Defined (Etype (R), N);
2060 Apply_Length_Check (R, Etype (L));
2062 if Nkind (N) = N_Op_Xor then
2063 Silly_Boolean_Array_Xor_Test (N, Etype (L));
2066 if Nkind (Parent (N)) = N_Assignment_Statement
2067 and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
2069 Build_Boolean_Array_Proc_Call (Parent (N), L, R);
2071 elsif Nkind (Parent (N)) = N_Op_Not
2072 and then Nkind (N) = N_Op_And
2074 Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
2079 Func_Body := Make_Boolean_Array_Op (Etype (L), N);
2080 Func_Name := Defining_Unit_Name (Specification (Func_Body));
2081 Insert_Action (N, Func_Body);
2083 -- Now rewrite the expression with a call
2086 Make_Function_Call (Loc,
2087 Name => New_Reference_To (Func_Name, Loc),
2088 Parameter_Associations =>
2091 Make_Type_Conversion
2092 (Loc, New_Reference_To (Etype (L), Loc), R))));
2094 Analyze_And_Resolve (N, Typ);
2097 end Expand_Boolean_Operator;
2099 -------------------------------
2100 -- Expand_Composite_Equality --
2101 -------------------------------
2103 -- This function is only called for comparing internal fields of composite
2104 -- types when these fields are themselves composites. This is a special
2105 -- case because it is not possible to respect normal Ada visibility rules.
2107 function Expand_Composite_Equality
2112 Bodies : List_Id) return Node_Id
2114 Loc : constant Source_Ptr := Sloc (Nod);
2115 Full_Type : Entity_Id;
2119 function Find_Primitive_Eq return Node_Id;
2120 -- AI05-0123: Locate primitive equality for type if it exists, and
2121 -- build the corresponding call. If operation is abstract, replace
2122 -- call with an explicit raise. Return Empty if there is no primitive.
2124 -----------------------
2125 -- Find_Primitive_Eq --
2126 -----------------------
2128 function Find_Primitive_Eq return Node_Id is
2133 Prim_E := First_Elmt (Collect_Primitive_Operations (Typ));
2134 while Present (Prim_E) loop
2135 Prim := Node (Prim_E);
2137 -- Locate primitive equality with the right signature
2139 if Chars (Prim) = Name_Op_Eq
2140 and then Etype (First_Formal (Prim)) =
2141 Etype (Next_Formal (First_Formal (Prim)))
2142 and then Etype (Prim) = Standard_Boolean
2144 if Is_Abstract_Subprogram (Prim) then
2146 Make_Raise_Program_Error (Loc,
2147 Reason => PE_Explicit_Raise);
2151 Make_Function_Call (Loc,
2152 Name => New_Reference_To (Prim, Loc),
2153 Parameter_Associations => New_List (Lhs, Rhs));
2160 -- If not found, predefined operation will be used
2163 end Find_Primitive_Eq;
2165 -- Start of processing for Expand_Composite_Equality
2168 if Is_Private_Type (Typ) then
2169 Full_Type := Underlying_Type (Typ);
2174 -- Defense against malformed private types with no completion the error
2175 -- will be diagnosed later by check_completion
2177 if No (Full_Type) then
2178 return New_Reference_To (Standard_False, Loc);
2181 Full_Type := Base_Type (Full_Type);
2183 if Is_Array_Type (Full_Type) then
2185 -- If the operand is an elementary type other than a floating-point
2186 -- type, then we can simply use the built-in block bitwise equality,
2187 -- since the predefined equality operators always apply and bitwise
2188 -- equality is fine for all these cases.
2190 if Is_Elementary_Type (Component_Type (Full_Type))
2191 and then not Is_Floating_Point_Type (Component_Type (Full_Type))
2193 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2195 -- For composite component types, and floating-point types, use the
2196 -- expansion. This deals with tagged component types (where we use
2197 -- the applicable equality routine) and floating-point, (where we
2198 -- need to worry about negative zeroes), and also the case of any
2199 -- composite type recursively containing such fields.
2202 return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
2205 elsif Is_Tagged_Type (Full_Type) then
2207 -- Call the primitive operation "=" of this type
2209 if Is_Class_Wide_Type (Full_Type) then
2210 Full_Type := Root_Type (Full_Type);
2213 -- If this is derived from an untagged private type completed with a
2214 -- tagged type, it does not have a full view, so we use the primitive
2215 -- operations of the private type. This check should no longer be
2216 -- necessary when these types receive their full views ???
2218 if Is_Private_Type (Typ)
2219 and then not Is_Tagged_Type (Typ)
2220 and then not Is_Controlled (Typ)
2221 and then Is_Derived_Type (Typ)
2222 and then No (Full_View (Typ))
2224 Prim := First_Elmt (Collect_Primitive_Operations (Typ));
2226 Prim := First_Elmt (Primitive_Operations (Full_Type));
2230 Eq_Op := Node (Prim);
2231 exit when Chars (Eq_Op) = Name_Op_Eq
2232 and then Etype (First_Formal (Eq_Op)) =
2233 Etype (Next_Formal (First_Formal (Eq_Op)))
2234 and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
2236 pragma Assert (Present (Prim));
2239 Eq_Op := Node (Prim);
2242 Make_Function_Call (Loc,
2243 Name => New_Reference_To (Eq_Op, Loc),
2244 Parameter_Associations =>
2246 (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
2247 Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
2249 elsif Is_Record_Type (Full_Type) then
2250 Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
2252 if Present (Eq_Op) then
2253 if Etype (First_Formal (Eq_Op)) /= Full_Type then
2255 -- Inherited equality from parent type. Convert the actuals to
2256 -- match signature of operation.
2259 T : constant Entity_Id := Etype (First_Formal (Eq_Op));
2263 Make_Function_Call (Loc,
2264 Name => New_Reference_To (Eq_Op, Loc),
2265 Parameter_Associations => New_List (
2266 OK_Convert_To (T, Lhs),
2267 OK_Convert_To (T, Rhs)));
2271 -- Comparison between Unchecked_Union components
2273 if Is_Unchecked_Union (Full_Type) then
2275 Lhs_Type : Node_Id := Full_Type;
2276 Rhs_Type : Node_Id := Full_Type;
2277 Lhs_Discr_Val : Node_Id;
2278 Rhs_Discr_Val : Node_Id;
2283 if Nkind (Lhs) = N_Selected_Component then
2284 Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
2289 if Nkind (Rhs) = N_Selected_Component then
2290 Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
2293 -- Lhs of the composite equality
2295 if Is_Constrained (Lhs_Type) then
2297 -- Since the enclosing record type can never be an
2298 -- Unchecked_Union (this code is executed for records
2299 -- that do not have variants), we may reference its
2302 if Nkind (Lhs) = N_Selected_Component
2303 and then Has_Per_Object_Constraint (
2304 Entity (Selector_Name (Lhs)))
2307 Make_Selected_Component (Loc,
2308 Prefix => Prefix (Lhs),
2311 (Get_Discriminant_Value
2312 (First_Discriminant (Lhs_Type),
2314 Stored_Constraint (Lhs_Type))));
2319 (Get_Discriminant_Value
2320 (First_Discriminant (Lhs_Type),
2322 Stored_Constraint (Lhs_Type)));
2326 -- It is not possible to infer the discriminant since
2327 -- the subtype is not constrained.
2330 Make_Raise_Program_Error (Loc,
2331 Reason => PE_Unchecked_Union_Restriction);
2334 -- Rhs of the composite equality
2336 if Is_Constrained (Rhs_Type) then
2337 if Nkind (Rhs) = N_Selected_Component
2338 and then Has_Per_Object_Constraint
2339 (Entity (Selector_Name (Rhs)))
2342 Make_Selected_Component (Loc,
2343 Prefix => Prefix (Rhs),
2346 (Get_Discriminant_Value
2347 (First_Discriminant (Rhs_Type),
2349 Stored_Constraint (Rhs_Type))));
2354 (Get_Discriminant_Value
2355 (First_Discriminant (Rhs_Type),
2357 Stored_Constraint (Rhs_Type)));
2362 Make_Raise_Program_Error (Loc,
2363 Reason => PE_Unchecked_Union_Restriction);
2366 -- Call the TSS equality function with the inferred
2367 -- discriminant values.
2370 Make_Function_Call (Loc,
2371 Name => New_Reference_To (Eq_Op, Loc),
2372 Parameter_Associations => New_List (
2381 Make_Function_Call (Loc,
2382 Name => New_Reference_To (Eq_Op, Loc),
2383 Parameter_Associations => New_List (Lhs, Rhs));
2387 elsif Ada_Version >= Ada_2012 then
2389 -- if no TSS has been created for the type, check whether there is
2390 -- a primitive equality declared for it.
2393 Ada_2012_Op : constant Node_Id := Find_Primitive_Eq;
2396 if Present (Ada_2012_Op) then
2400 -- Use predefined equality if no user-defined primitive exists
2402 return Make_Op_Eq (Loc, Lhs, Rhs);
2407 return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
2411 -- If not array or record type, it is predefined equality.
2413 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2415 end Expand_Composite_Equality;
2417 ------------------------
2418 -- Expand_Concatenate --
2419 ------------------------
2421 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
2422 Loc : constant Source_Ptr := Sloc (Cnode);
2424 Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
2425 -- Result type of concatenation
2427 Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
2428 -- Component type. Elements of this component type can appear as one
2429 -- of the operands of concatenation as well as arrays.
2431 Istyp : constant Entity_Id := Etype (First_Index (Atyp));
2434 Ityp : constant Entity_Id := Base_Type (Istyp);
2435 -- Index type. This is the base type of the index subtype, and is used
2436 -- for all computed bounds (which may be out of range of Istyp in the
2437 -- case of null ranges).
2440 -- This is the type we use to do arithmetic to compute the bounds and
2441 -- lengths of operands. The choice of this type is a little subtle and
2442 -- is discussed in a separate section at the start of the body code.
2444 Concatenation_Error : exception;
2445 -- Raised if concatenation is sure to raise a CE
2447 Result_May_Be_Null : Boolean := True;
2448 -- Reset to False if at least one operand is encountered which is known
2449 -- at compile time to be non-null. Used for handling the special case
2450 -- of setting the high bound to the last operand high bound for a null
2451 -- result, thus ensuring a proper high bound in the super-flat case.
2453 N : constant Nat := List_Length (Opnds);
2454 -- Number of concatenation operands including possibly null operands
2457 -- Number of operands excluding any known to be null, except that the
2458 -- last operand is always retained, in case it provides the bounds for
2462 -- Current operand being processed in the loop through operands. After
2463 -- this loop is complete, always contains the last operand (which is not
2464 -- the same as Operands (NN), since null operands are skipped).
2466 -- Arrays describing the operands, only the first NN entries of each
2467 -- array are set (NN < N when we exclude known null operands).
2469 Is_Fixed_Length : array (1 .. N) of Boolean;
2470 -- True if length of corresponding operand known at compile time
2472 Operands : array (1 .. N) of Node_Id;
2473 -- Set to the corresponding entry in the Opnds list (but note that null
2474 -- operands are excluded, so not all entries in the list are stored).
2476 Fixed_Length : array (1 .. N) of Uint;
2477 -- Set to length of operand. Entries in this array are set only if the
2478 -- corresponding entry in Is_Fixed_Length is True.
2480 Opnd_Low_Bound : array (1 .. N) of Node_Id;
2481 -- Set to lower bound of operand. Either an integer literal in the case
2482 -- where the bound is known at compile time, else actual lower bound.
2483 -- The operand low bound is of type Ityp.
2485 Var_Length : array (1 .. N) of Entity_Id;
2486 -- Set to an entity of type Natural that contains the length of an
2487 -- operand whose length is not known at compile time. Entries in this
2488 -- array are set only if the corresponding entry in Is_Fixed_Length
2489 -- is False. The entity is of type Artyp.
2491 Aggr_Length : array (0 .. N) of Node_Id;
2492 -- The J'th entry in an expression node that represents the total length
2493 -- of operands 1 through J. It is either an integer literal node, or a
2494 -- reference to a constant entity with the right value, so it is fine
2495 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2496 -- entry always is set to zero. The length is of type Artyp.
2498 Low_Bound : Node_Id;
2499 -- A tree node representing the low bound of the result (of type Ityp).
2500 -- This is either an integer literal node, or an identifier reference to
2501 -- a constant entity initialized to the appropriate value.
2503 Last_Opnd_High_Bound : Node_Id;
2504 -- A tree node representing the high bound of the last operand. This
2505 -- need only be set if the result could be null. It is used for the
2506 -- special case of setting the right high bound for a null result.
2507 -- This is of type Ityp.
2509 High_Bound : Node_Id;
2510 -- A tree node representing the high bound of the result (of type Ityp)
2513 -- Result of the concatenation (of type Ityp)
2515 Actions : constant List_Id := New_List;
2516 -- Collect actions to be inserted if Save_Space is False
2518 Save_Space : Boolean;
2519 pragma Warnings (Off, Save_Space);
2520 -- Set to True if we are saving generated code space by calling routines
2521 -- in packages System.Concat_n.
2523 Known_Non_Null_Operand_Seen : Boolean;
2524 -- Set True during generation of the assignments of operands into
2525 -- result once an operand known to be non-null has been seen.
2527 function Make_Artyp_Literal (Val : Nat) return Node_Id;
2528 -- This function makes an N_Integer_Literal node that is returned in
2529 -- analyzed form with the type set to Artyp. Importantly this literal
2530 -- is not flagged as static, so that if we do computations with it that
2531 -- result in statically detected out of range conditions, we will not
2532 -- generate error messages but instead warning messages.
2534 function To_Artyp (X : Node_Id) return Node_Id;
2535 -- Given a node of type Ityp, returns the corresponding value of type
2536 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2537 -- For enum types, the Pos of the value is returned.
2539 function To_Ityp (X : Node_Id) return Node_Id;
2540 -- The inverse function (uses Val in the case of enumeration types)
2542 ------------------------
2543 -- Make_Artyp_Literal --
2544 ------------------------
2546 function Make_Artyp_Literal (Val : Nat) return Node_Id is
2547 Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
2549 Set_Etype (Result, Artyp);
2550 Set_Analyzed (Result, True);
2551 Set_Is_Static_Expression (Result, False);
2553 end Make_Artyp_Literal;
2559 function To_Artyp (X : Node_Id) return Node_Id is
2561 if Ityp = Base_Type (Artyp) then
2564 elsif Is_Enumeration_Type (Ityp) then
2566 Make_Attribute_Reference (Loc,
2567 Prefix => New_Occurrence_Of (Ityp, Loc),
2568 Attribute_Name => Name_Pos,
2569 Expressions => New_List (X));
2572 return Convert_To (Artyp, X);
2580 function To_Ityp (X : Node_Id) return Node_Id is
2582 if Is_Enumeration_Type (Ityp) then
2584 Make_Attribute_Reference (Loc,
2585 Prefix => New_Occurrence_Of (Ityp, Loc),
2586 Attribute_Name => Name_Val,
2587 Expressions => New_List (X));
2589 -- Case where we will do a type conversion
2592 if Ityp = Base_Type (Artyp) then
2595 return Convert_To (Ityp, X);
2600 -- Local Declarations
2602 Opnd_Typ : Entity_Id;
2609 -- Start of processing for Expand_Concatenate
2612 -- Choose an appropriate computational type
2614 -- We will be doing calculations of lengths and bounds in this routine
2615 -- and computing one from the other in some cases, e.g. getting the high
2616 -- bound by adding the length-1 to the low bound.
2618 -- We can't just use the index type, or even its base type for this
2619 -- purpose for two reasons. First it might be an enumeration type which
2620 -- is not suitable for computations of any kind, and second it may
2621 -- simply not have enough range. For example if the index type is
2622 -- -128..+127 then lengths can be up to 256, which is out of range of
2625 -- For enumeration types, we can simply use Standard_Integer, this is
2626 -- sufficient since the actual number of enumeration literals cannot
2627 -- possibly exceed the range of integer (remember we will be doing the
2628 -- arithmetic with POS values, not representation values).
2630 if Is_Enumeration_Type (Ityp) then
2631 Artyp := Standard_Integer;
2633 -- If index type is Positive, we use the standard unsigned type, to give
2634 -- more room on the top of the range, obviating the need for an overflow
2635 -- check when creating the upper bound. This is needed to avoid junk
2636 -- overflow checks in the common case of String types.
2638 -- ??? Disabled for now
2640 -- elsif Istyp = Standard_Positive then
2641 -- Artyp := Standard_Unsigned;
2643 -- For modular types, we use a 32-bit modular type for types whose size
2644 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2645 -- identity type, and for larger unsigned types we use 64-bits.
2647 elsif Is_Modular_Integer_Type (Ityp) then
2648 if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
2649 Artyp := Standard_Unsigned;
2650 elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
2653 Artyp := RTE (RE_Long_Long_Unsigned);
2656 -- Similar treatment for signed types
2659 if RM_Size (Ityp) < RM_Size (Standard_Integer) then
2660 Artyp := Standard_Integer;
2661 elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
2664 Artyp := Standard_Long_Long_Integer;
2668 -- Supply dummy entry at start of length array
2670 Aggr_Length (0) := Make_Artyp_Literal (0);
2672 -- Go through operands setting up the above arrays
2676 Opnd := Remove_Head (Opnds);
2677 Opnd_Typ := Etype (Opnd);
2679 -- The parent got messed up when we put the operands in a list,
2680 -- so now put back the proper parent for the saved operand, that
2681 -- is to say the concatenation node, to make sure that each operand
2682 -- is seen as a subexpression, e.g. if actions must be inserted.
2684 Set_Parent (Opnd, Cnode);
2686 -- Set will be True when we have setup one entry in the array
2690 -- Singleton element (or character literal) case
2692 if Base_Type (Opnd_Typ) = Ctyp then
2694 Operands (NN) := Opnd;
2695 Is_Fixed_Length (NN) := True;
2696 Fixed_Length (NN) := Uint_1;
2697 Result_May_Be_Null := False;
2699 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2700 -- since we know that the result cannot be null).
2702 Opnd_Low_Bound (NN) :=
2703 Make_Attribute_Reference (Loc,
2704 Prefix => New_Reference_To (Istyp, Loc),
2705 Attribute_Name => Name_First);
2709 -- String literal case (can only occur for strings of course)
2711 elsif Nkind (Opnd) = N_String_Literal then
2712 Len := String_Literal_Length (Opnd_Typ);
2715 Result_May_Be_Null := False;
2718 -- Capture last operand high bound if result could be null
2720 if J = N and then Result_May_Be_Null then
2721 Last_Opnd_High_Bound :=
2724 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
2725 Right_Opnd => Make_Integer_Literal (Loc, 1));
2728 -- Skip null string literal
2730 if J < N and then Len = 0 then
2735 Operands (NN) := Opnd;
2736 Is_Fixed_Length (NN) := True;
2738 -- Set length and bounds
2740 Fixed_Length (NN) := Len;
2742 Opnd_Low_Bound (NN) :=
2743 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
2750 -- Check constrained case with known bounds
2752 if Is_Constrained (Opnd_Typ) then
2754 Index : constant Node_Id := First_Index (Opnd_Typ);
2755 Indx_Typ : constant Entity_Id := Etype (Index);
2756 Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
2757 Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
2760 -- Fixed length constrained array type with known at compile
2761 -- time bounds is last case of fixed length operand.
2763 if Compile_Time_Known_Value (Lo)
2765 Compile_Time_Known_Value (Hi)
2768 Loval : constant Uint := Expr_Value (Lo);
2769 Hival : constant Uint := Expr_Value (Hi);
2770 Len : constant Uint :=
2771 UI_Max (Hival - Loval + 1, Uint_0);
2775 Result_May_Be_Null := False;
2778 -- Capture last operand bound if result could be null
2780 if J = N and then Result_May_Be_Null then
2781 Last_Opnd_High_Bound :=
2783 Make_Integer_Literal (Loc, Expr_Value (Hi)));
2786 -- Exclude null length case unless last operand
2788 if J < N and then Len = 0 then
2793 Operands (NN) := Opnd;
2794 Is_Fixed_Length (NN) := True;
2795 Fixed_Length (NN) := Len;
2797 Opnd_Low_Bound (NN) :=
2799 (Make_Integer_Literal (Loc, Expr_Value (Lo)));
2806 -- All cases where the length is not known at compile time, or the
2807 -- special case of an operand which is known to be null but has a
2808 -- lower bound other than 1 or is other than a string type.
2813 -- Capture operand bounds
2815 Opnd_Low_Bound (NN) :=
2816 Make_Attribute_Reference (Loc,
2818 Duplicate_Subexpr (Opnd, Name_Req => True),
2819 Attribute_Name => Name_First);
2821 if J = N and Result_May_Be_Null then
2822 Last_Opnd_High_Bound :=
2824 Make_Attribute_Reference (Loc,
2826 Duplicate_Subexpr (Opnd, Name_Req => True),
2827 Attribute_Name => Name_Last));
2830 -- Capture length of operand in entity
2832 Operands (NN) := Opnd;
2833 Is_Fixed_Length (NN) := False;
2835 Var_Length (NN) := Make_Temporary (Loc, 'L');
2838 Make_Object_Declaration (Loc,
2839 Defining_Identifier => Var_Length (NN),
2840 Constant_Present => True,
2841 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2843 Make_Attribute_Reference (Loc,
2845 Duplicate_Subexpr (Opnd, Name_Req => True),
2846 Attribute_Name => Name_Length)));
2850 -- Set next entry in aggregate length array
2852 -- For first entry, make either integer literal for fixed length
2853 -- or a reference to the saved length for variable length.
2856 if Is_Fixed_Length (1) then
2857 Aggr_Length (1) := Make_Integer_Literal (Loc, Fixed_Length (1));
2859 Aggr_Length (1) := New_Reference_To (Var_Length (1), Loc);
2862 -- If entry is fixed length and only fixed lengths so far, make
2863 -- appropriate new integer literal adding new length.
2865 elsif Is_Fixed_Length (NN)
2866 and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
2869 Make_Integer_Literal (Loc,
2870 Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
2872 -- All other cases, construct an addition node for the length and
2873 -- create an entity initialized to this length.
2876 Ent := Make_Temporary (Loc, 'L');
2878 if Is_Fixed_Length (NN) then
2879 Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
2881 Clen := New_Reference_To (Var_Length (NN), Loc);
2885 Make_Object_Declaration (Loc,
2886 Defining_Identifier => Ent,
2887 Constant_Present => True,
2888 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2891 Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
2892 Right_Opnd => Clen)));
2894 Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
2901 -- If we have only skipped null operands, return the last operand
2908 -- If we have only one non-null operand, return it and we are done.
2909 -- There is one case in which this cannot be done, and that is when
2910 -- the sole operand is of the element type, in which case it must be
2911 -- converted to an array, and the easiest way of doing that is to go
2912 -- through the normal general circuit.
2915 and then Base_Type (Etype (Operands (1))) /= Ctyp
2917 Result := Operands (1);
2921 -- Cases where we have a real concatenation
2923 -- Next step is to find the low bound for the result array that we
2924 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
2926 -- If the ultimate ancestor of the index subtype is a constrained array
2927 -- definition, then the lower bound is that of the index subtype as
2928 -- specified by (RM 4.5.3(6)).
2930 -- The right test here is to go to the root type, and then the ultimate
2931 -- ancestor is the first subtype of this root type.
2933 if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
2935 Make_Attribute_Reference (Loc,
2937 New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
2938 Attribute_Name => Name_First);
2940 -- If the first operand in the list has known length we know that
2941 -- the lower bound of the result is the lower bound of this operand.
2943 elsif Is_Fixed_Length (1) then
2944 Low_Bound := Opnd_Low_Bound (1);
2946 -- OK, we don't know the lower bound, we have to build a horrible
2947 -- expression actions node of the form
2949 -- if Cond1'Length /= 0 then
2952 -- if Opnd2'Length /= 0 then
2957 -- The nesting ends either when we hit an operand whose length is known
2958 -- at compile time, or on reaching the last operand, whose low bound we
2959 -- take unconditionally whether or not it is null. It's easiest to do
2960 -- this with a recursive procedure:
2964 function Get_Known_Bound (J : Nat) return Node_Id;
2965 -- Returns the lower bound determined by operands J .. NN
2967 ---------------------
2968 -- Get_Known_Bound --
2969 ---------------------
2971 function Get_Known_Bound (J : Nat) return Node_Id is
2973 if Is_Fixed_Length (J) or else J = NN then
2974 return New_Copy (Opnd_Low_Bound (J));
2978 Make_Conditional_Expression (Loc,
2979 Expressions => New_List (
2982 Left_Opnd => New_Reference_To (Var_Length (J), Loc),
2983 Right_Opnd => Make_Integer_Literal (Loc, 0)),
2985 New_Copy (Opnd_Low_Bound (J)),
2986 Get_Known_Bound (J + 1)));
2988 end Get_Known_Bound;
2991 Ent := Make_Temporary (Loc, 'L');
2994 Make_Object_Declaration (Loc,
2995 Defining_Identifier => Ent,
2996 Constant_Present => True,
2997 Object_Definition => New_Occurrence_Of (Ityp, Loc),
2998 Expression => Get_Known_Bound (1)));
3000 Low_Bound := New_Reference_To (Ent, Loc);
3004 -- Now we can safely compute the upper bound, normally
3005 -- Low_Bound + Length - 1.
3010 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3012 Make_Op_Subtract (Loc,
3013 Left_Opnd => New_Copy (Aggr_Length (NN)),
3014 Right_Opnd => Make_Artyp_Literal (1))));
3016 -- Note that calculation of the high bound may cause overflow in some
3017 -- very weird cases, so in the general case we need an overflow check on
3018 -- the high bound. We can avoid this for the common case of string types
3019 -- and other types whose index is Positive, since we chose a wider range
3020 -- for the arithmetic type.
3022 if Istyp /= Standard_Positive then
3023 Activate_Overflow_Check (High_Bound);
3026 -- Handle the exceptional case where the result is null, in which case
3027 -- case the bounds come from the last operand (so that we get the proper
3028 -- bounds if the last operand is super-flat).
3030 if Result_May_Be_Null then
3032 Make_Conditional_Expression (Loc,
3033 Expressions => New_List (
3035 Left_Opnd => New_Copy (Aggr_Length (NN)),
3036 Right_Opnd => Make_Artyp_Literal (0)),
3037 Last_Opnd_High_Bound,
3041 -- Here is where we insert the saved up actions
3043 Insert_Actions (Cnode, Actions, Suppress => All_Checks);
3045 -- Now we construct an array object with appropriate bounds. We mark
3046 -- the target as internal to prevent useless initialization when
3047 -- Initialize_Scalars is enabled. Also since this is the actual result
3048 -- entity, we make sure we have debug information for the result.
3050 Ent := Make_Temporary (Loc, 'S');
3051 Set_Is_Internal (Ent);
3052 Set_Needs_Debug_Info (Ent);
3054 -- If the bound is statically known to be out of range, we do not want
3055 -- to abort, we want a warning and a runtime constraint error. Note that
3056 -- we have arranged that the result will not be treated as a static
3057 -- constant, so we won't get an illegality during this insertion.
3059 Insert_Action (Cnode,
3060 Make_Object_Declaration (Loc,
3061 Defining_Identifier => Ent,
3062 Object_Definition =>
3063 Make_Subtype_Indication (Loc,
3064 Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
3066 Make_Index_Or_Discriminant_Constraint (Loc,
3067 Constraints => New_List (
3069 Low_Bound => Low_Bound,
3070 High_Bound => High_Bound))))),
3071 Suppress => All_Checks);
3073 -- If the result of the concatenation appears as the initializing
3074 -- expression of an object declaration, we can just rename the
3075 -- result, rather than copying it.
3077 Set_OK_To_Rename (Ent);
3079 -- Catch the static out of range case now
3081 if Raises_Constraint_Error (High_Bound) then
3082 raise Concatenation_Error;
3085 -- Now we will generate the assignments to do the actual concatenation
3087 -- There is one case in which we will not do this, namely when all the
3088 -- following conditions are met:
3090 -- The result type is Standard.String
3092 -- There are nine or fewer retained (non-null) operands
3094 -- The optimization level is -O0
3096 -- The corresponding System.Concat_n.Str_Concat_n routine is
3097 -- available in the run time.
3099 -- The debug flag gnatd.c is not set
3101 -- If all these conditions are met then we generate a call to the
3102 -- relevant concatenation routine. The purpose of this is to avoid
3103 -- undesirable code bloat at -O0.
3105 if Atyp = Standard_String
3106 and then NN in 2 .. 9
3107 and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC)
3108 and then not Debug_Flag_Dot_C
3111 RR : constant array (Nat range 2 .. 9) of RE_Id :=
3122 if RTE_Available (RR (NN)) then
3124 Opnds : constant List_Id :=
3125 New_List (New_Occurrence_Of (Ent, Loc));
3128 for J in 1 .. NN loop
3129 if Is_List_Member (Operands (J)) then
3130 Remove (Operands (J));
3133 if Base_Type (Etype (Operands (J))) = Ctyp then
3135 Make_Aggregate (Loc,
3136 Component_Associations => New_List (
3137 Make_Component_Association (Loc,
3138 Choices => New_List (
3139 Make_Integer_Literal (Loc, 1)),
3140 Expression => Operands (J)))));
3143 Append_To (Opnds, Operands (J));
3147 Insert_Action (Cnode,
3148 Make_Procedure_Call_Statement (Loc,
3149 Name => New_Reference_To (RTE (RR (NN)), Loc),
3150 Parameter_Associations => Opnds));
3152 Result := New_Reference_To (Ent, Loc);
3159 -- Not special case so generate the assignments
3161 Known_Non_Null_Operand_Seen := False;
3163 for J in 1 .. NN loop
3165 Lo : constant Node_Id :=
3167 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3168 Right_Opnd => Aggr_Length (J - 1));
3170 Hi : constant Node_Id :=
3172 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3174 Make_Op_Subtract (Loc,
3175 Left_Opnd => Aggr_Length (J),
3176 Right_Opnd => Make_Artyp_Literal (1)));
3179 -- Singleton case, simple assignment
3181 if Base_Type (Etype (Operands (J))) = Ctyp then
3182 Known_Non_Null_Operand_Seen := True;
3183 Insert_Action (Cnode,
3184 Make_Assignment_Statement (Loc,
3186 Make_Indexed_Component (Loc,
3187 Prefix => New_Occurrence_Of (Ent, Loc),
3188 Expressions => New_List (To_Ityp (Lo))),
3189 Expression => Operands (J)),
3190 Suppress => All_Checks);
3192 -- Array case, slice assignment, skipped when argument is fixed
3193 -- length and known to be null.
3195 elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
3198 Make_Assignment_Statement (Loc,
3202 New_Occurrence_Of (Ent, Loc),
3205 Low_Bound => To_Ityp (Lo),
3206 High_Bound => To_Ityp (Hi))),
3207 Expression => Operands (J));
3209 if Is_Fixed_Length (J) then
3210 Known_Non_Null_Operand_Seen := True;
3212 elsif not Known_Non_Null_Operand_Seen then
3214 -- Here if operand length is not statically known and no
3215 -- operand known to be non-null has been processed yet.
3216 -- If operand length is 0, we do not need to perform the
3217 -- assignment, and we must avoid the evaluation of the
3218 -- high bound of the slice, since it may underflow if the
3219 -- low bound is Ityp'First.
3222 Make_Implicit_If_Statement (Cnode,
3226 New_Occurrence_Of (Var_Length (J), Loc),
3227 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3228 Then_Statements => New_List (Assign));
3231 Insert_Action (Cnode, Assign, Suppress => All_Checks);
3237 -- Finally we build the result, which is a reference to the array object
3239 Result := New_Reference_To (Ent, Loc);
3242 Rewrite (Cnode, Result);
3243 Analyze_And_Resolve (Cnode, Atyp);
3246 when Concatenation_Error =>
3248 -- Kill warning generated for the declaration of the static out of
3249 -- range high bound, and instead generate a Constraint_Error with
3250 -- an appropriate specific message.
3252 Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
3253 Apply_Compile_Time_Constraint_Error
3255 Msg => "concatenation result upper bound out of range?",
3256 Reason => CE_Range_Check_Failed);
3257 -- Set_Etype (Cnode, Atyp);
3258 end Expand_Concatenate;
3260 ------------------------
3261 -- Expand_N_Allocator --
3262 ------------------------
3264 procedure Expand_N_Allocator (N : Node_Id) is
3265 PtrT : constant Entity_Id := Etype (N);
3266 Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT));
3267 Etyp : constant Entity_Id := Etype (Expression (N));
3268 Loc : constant Source_Ptr := Sloc (N);
3273 procedure Rewrite_Coextension (N : Node_Id);
3274 -- Static coextensions have the same lifetime as the entity they
3275 -- constrain. Such occurrences can be rewritten as aliased objects
3276 -- and their unrestricted access used instead of the coextension.
3278 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id;
3279 -- Given a constrained array type E, returns a node representing the
3280 -- code to compute the size in storage elements for the given type.
3281 -- This is done without using the attribute (which malfunctions for
3284 -------------------------
3285 -- Rewrite_Coextension --
3286 -------------------------
3288 procedure Rewrite_Coextension (N : Node_Id) is
3289 Temp_Id : constant Node_Id := Make_Temporary (Loc, 'C');
3290 Temp_Decl : Node_Id;
3291 Insert_Nod : Node_Id;
3295 -- Cnn : aliased Etyp;
3298 Make_Object_Declaration (Loc,
3299 Defining_Identifier => Temp_Id,
3300 Aliased_Present => True,
3301 Object_Definition => New_Occurrence_Of (Etyp, Loc));
3303 if Nkind (Expression (N)) = N_Qualified_Expression then
3304 Set_Expression (Temp_Decl, Expression (Expression (N)));
3307 -- Find the proper insertion node for the declaration
3309 Insert_Nod := Parent (N);
3310 while Present (Insert_Nod) loop
3312 Nkind (Insert_Nod) in N_Statement_Other_Than_Procedure_Call
3313 or else Nkind (Insert_Nod) = N_Procedure_Call_Statement
3314 or else Nkind (Insert_Nod) in N_Declaration;
3316 Insert_Nod := Parent (Insert_Nod);
3319 Insert_Before (Insert_Nod, Temp_Decl);
3320 Analyze (Temp_Decl);
3323 Make_Attribute_Reference (Loc,
3324 Prefix => New_Occurrence_Of (Temp_Id, Loc),
3325 Attribute_Name => Name_Unrestricted_Access));
3327 Analyze_And_Resolve (N, PtrT);
3328 end Rewrite_Coextension;
3330 ------------------------------
3331 -- Size_In_Storage_Elements --
3332 ------------------------------
3334 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is
3336 -- Logically this just returns E'Max_Size_In_Storage_Elements.
3337 -- However, the reason for the existence of this function is
3338 -- to construct a test for sizes too large, which means near the
3339 -- 32-bit limit on a 32-bit machine, and precisely the trouble
3340 -- is that we get overflows when sizes are greater than 2**31.
3342 -- So what we end up doing for array types is to use the expression:
3344 -- number-of-elements * component_type'Max_Size_In_Storage_Elements
3346 -- which avoids this problem. All this is a bit bogus, but it does
3347 -- mean we catch common cases of trying to allocate arrays that
3348 -- are too large, and which in the absence of a check results in
3349 -- undetected chaos ???
3356 for J in 1 .. Number_Dimensions (E) loop
3358 Make_Attribute_Reference (Loc,
3359 Prefix => New_Occurrence_Of (E, Loc),
3360 Attribute_Name => Name_Length,
3361 Expressions => New_List (Make_Integer_Literal (Loc, J)));
3368 Make_Op_Multiply (Loc,
3375 Make_Op_Multiply (Loc,
3378 Make_Attribute_Reference (Loc,
3379 Prefix => New_Occurrence_Of (Component_Type (E), Loc),
3380 Attribute_Name => Name_Max_Size_In_Storage_Elements));
3382 end Size_In_Storage_Elements;
3384 -- Start of processing for Expand_N_Allocator
3387 -- RM E.2.3(22). We enforce that the expected type of an allocator
3388 -- shall not be a remote access-to-class-wide-limited-private type
3390 -- Why is this being done at expansion time, seems clearly wrong ???
3392 Validate_Remote_Access_To_Class_Wide_Type (N);
3394 -- Set the Storage Pool
3396 Set_Storage_Pool (N, Associated_Storage_Pool (Root_Type (PtrT)));
3398 if Present (Storage_Pool (N)) then
3399 if Is_RTE (Storage_Pool (N), RE_SS_Pool) then
3400 if VM_Target = No_VM then
3401 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3404 elsif Is_Class_Wide_Type (Etype (Storage_Pool (N))) then
3405 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3408 Set_Procedure_To_Call (N,
3409 Find_Prim_Op (Etype (Storage_Pool (N)), Name_Allocate));
3413 -- Under certain circumstances we can replace an allocator by an access
3414 -- to statically allocated storage. The conditions, as noted in AARM
3415 -- 3.10 (10c) are as follows:
3417 -- Size and initial value is known at compile time
3418 -- Access type is access-to-constant
3420 -- The allocator is not part of a constraint on a record component,
3421 -- because in that case the inserted actions are delayed until the
3422 -- record declaration is fully analyzed, which is too late for the
3423 -- analysis of the rewritten allocator.
3425 if Is_Access_Constant (PtrT)
3426 and then Nkind (Expression (N)) = N_Qualified_Expression
3427 and then Compile_Time_Known_Value (Expression (Expression (N)))
3428 and then Size_Known_At_Compile_Time
3429 (Etype (Expression (Expression (N))))
3430 and then not Is_Record_Type (Current_Scope)
3432 -- Here we can do the optimization. For the allocator
3436 -- We insert an object declaration
3438 -- Tnn : aliased x := y;
3440 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3441 -- marked as requiring static allocation.
3443 Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
3444 Desig := Subtype_Mark (Expression (N));
3446 -- If context is constrained, use constrained subtype directly,
3447 -- so that the constant is not labelled as having a nominally
3448 -- unconstrained subtype.
3450 if Entity (Desig) = Base_Type (Dtyp) then
3451 Desig := New_Occurrence_Of (Dtyp, Loc);
3455 Make_Object_Declaration (Loc,
3456 Defining_Identifier => Temp,
3457 Aliased_Present => True,
3458 Constant_Present => Is_Access_Constant (PtrT),
3459 Object_Definition => Desig,
3460 Expression => Expression (Expression (N))));
3463 Make_Attribute_Reference (Loc,
3464 Prefix => New_Occurrence_Of (Temp, Loc),
3465 Attribute_Name => Name_Unrestricted_Access));
3467 Analyze_And_Resolve (N, PtrT);
3469 -- We set the variable as statically allocated, since we don't want
3470 -- it going on the stack of the current procedure!
3472 Set_Is_Statically_Allocated (Temp);
3476 -- Same if the allocator is an access discriminant for a local object:
3477 -- instead of an allocator we create a local value and constrain the
3478 -- enclosing object with the corresponding access attribute.
3480 if Is_Static_Coextension (N) then
3481 Rewrite_Coextension (N);
3485 -- Check for size too large, we do this because the back end misses
3486 -- proper checks here and can generate rubbish allocation calls when
3487 -- we are near the limit. We only do this for the 32-bit address case
3488 -- since that is from a practical point of view where we see a problem.
3490 if System_Address_Size = 32
3491 and then not Storage_Checks_Suppressed (PtrT)
3492 and then not Storage_Checks_Suppressed (Dtyp)
3493 and then not Storage_Checks_Suppressed (Etyp)
3495 -- The check we want to generate should look like
3497 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
3498 -- raise Storage_Error;
3501 -- where 3.5 gigabytes is a constant large enough to accommodate any
3502 -- reasonable request for. But we can't do it this way because at
3503 -- least at the moment we don't compute this attribute right, and
3504 -- can silently give wrong results when the result gets large. Since
3505 -- this is all about large results, that's bad, so instead we only
3506 -- apply the check for constrained arrays, and manually compute the
3507 -- value of the attribute ???
3509 if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
3511 Make_Raise_Storage_Error (Loc,
3514 Left_Opnd => Size_In_Storage_Elements (Etyp),
3516 Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))),
3517 Reason => SE_Object_Too_Large));
3521 -- Handle case of qualified expression (other than optimization above)
3522 -- First apply constraint checks, because the bounds or discriminants
3523 -- in the aggregate might not match the subtype mark in the allocator.
3525 if Nkind (Expression (N)) = N_Qualified_Expression then
3526 Apply_Constraint_Check
3527 (Expression (Expression (N)), Etype (Expression (N)));
3529 Expand_Allocator_Expression (N);
3533 -- If the allocator is for a type which requires initialization, and
3534 -- there is no initial value (i.e. operand is a subtype indication
3535 -- rather than a qualified expression), then we must generate a call to
3536 -- the initialization routine using an expressions action node:
3538 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3540 -- Here ptr_T is the pointer type for the allocator, and T is the
3541 -- subtype of the allocator. A special case arises if the designated
3542 -- type of the access type is a task or contains tasks. In this case
3543 -- the call to Init (Temp.all ...) is replaced by code that ensures
3544 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3545 -- for details). In addition, if the type T is a task T, then the
3546 -- first argument to Init must be converted to the task record type.
3549 T : constant Entity_Id := Entity (Expression (N));
3555 Init_Arg1 : Node_Id;
3556 Temp_Decl : Node_Id;
3557 Temp_Type : Entity_Id;
3560 if No_Initialization (N) then
3562 -- Even though this might be a simple allocation, create a custom
3563 -- Allocate if the context requires it. Since .NET/JVM compilers
3564 -- do not support pools, this step is skipped.
3566 if VM_Target = No_VM
3567 and then Present (Associated_Collection (PtrT))
3569 Build_Allocate_Deallocate_Proc
3571 Is_Allocate => True);
3574 -- Case of no initialization procedure present
3576 elsif not Has_Non_Null_Base_Init_Proc (T) then
3578 -- Case of simple initialization required
3580 if Needs_Simple_Initialization (T) then
3581 Check_Restriction (No_Default_Initialization, N);
3582 Rewrite (Expression (N),
3583 Make_Qualified_Expression (Loc,
3584 Subtype_Mark => New_Occurrence_Of (T, Loc),
3585 Expression => Get_Simple_Init_Val (T, N)));
3587 Analyze_And_Resolve (Expression (Expression (N)), T);
3588 Analyze_And_Resolve (Expression (N), T);
3589 Set_Paren_Count (Expression (Expression (N)), 1);
3590 Expand_N_Allocator (N);
3592 -- No initialization required
3598 -- Case of initialization procedure present, must be called
3601 Check_Restriction (No_Default_Initialization, N);
3603 if not Restriction_Active (No_Default_Initialization) then
3604 Init := Base_Init_Proc (T);
3606 Temp := Make_Temporary (Loc, 'P');
3608 -- Construct argument list for the initialization routine call
3611 Make_Explicit_Dereference (Loc,
3613 New_Reference_To (Temp, Loc));
3615 Set_Assignment_OK (Init_Arg1);
3618 -- The initialization procedure expects a specific type. if the
3619 -- context is access to class wide, indicate that the object
3620 -- being allocated has the right specific type.
3622 if Is_Class_Wide_Type (Dtyp) then
3623 Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1);
3626 -- If designated type is a concurrent type or if it is private
3627 -- type whose definition is a concurrent type, the first
3628 -- argument in the Init routine has to be unchecked conversion
3629 -- to the corresponding record type. If the designated type is
3630 -- a derived type, also convert the argument to its root type.
3632 if Is_Concurrent_Type (T) then
3634 Unchecked_Convert_To (
3635 Corresponding_Record_Type (T), Init_Arg1);
3637 elsif Is_Private_Type (T)
3638 and then Present (Full_View (T))
3639 and then Is_Concurrent_Type (Full_View (T))
3642 Unchecked_Convert_To
3643 (Corresponding_Record_Type (Full_View (T)), Init_Arg1);
3645 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3647 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3650 Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1);
3651 Set_Etype (Init_Arg1, Ftyp);
3655 Args := New_List (Init_Arg1);
3657 -- For the task case, pass the Master_Id of the access type as
3658 -- the value of the _Master parameter, and _Chain as the value
3659 -- of the _Chain parameter (_Chain will be defined as part of
3660 -- the generated code for the allocator).
3662 -- In Ada 2005, the context may be a function that returns an
3663 -- anonymous access type. In that case the Master_Id has been
3664 -- created when expanding the function declaration.
3666 if Has_Task (T) then
3667 if No (Master_Id (Base_Type (PtrT))) then
3669 -- The designated type was an incomplete type, and the
3670 -- access type did not get expanded. Salvage it now.
3672 if not Restriction_Active (No_Task_Hierarchy) then
3673 pragma Assert (Present (Parent (Base_Type (PtrT))));
3674 Expand_N_Full_Type_Declaration
3675 (Parent (Base_Type (PtrT)));
3679 -- If the context of the allocator is a declaration or an
3680 -- assignment, we can generate a meaningful image for it,
3681 -- even though subsequent assignments might remove the
3682 -- connection between task and entity. We build this image
3683 -- when the left-hand side is a simple variable, a simple
3684 -- indexed assignment or a simple selected component.
3686 if Nkind (Parent (N)) = N_Assignment_Statement then
3688 Nam : constant Node_Id := Name (Parent (N));
3691 if Is_Entity_Name (Nam) then
3693 Build_Task_Image_Decls
3696 (Entity (Nam), Sloc (Nam)), T);
3698 elsif Nkind_In (Nam, N_Indexed_Component,
3699 N_Selected_Component)
3700 and then Is_Entity_Name (Prefix (Nam))
3703 Build_Task_Image_Decls
3704 (Loc, Nam, Etype (Prefix (Nam)));
3706 Decls := Build_Task_Image_Decls (Loc, T, T);
3710 elsif Nkind (Parent (N)) = N_Object_Declaration then
3712 Build_Task_Image_Decls
3713 (Loc, Defining_Identifier (Parent (N)), T);
3716 Decls := Build_Task_Image_Decls (Loc, T, T);
3719 if Restriction_Active (No_Task_Hierarchy) then
3721 New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
3725 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3728 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3730 Decl := Last (Decls);
3732 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3734 -- Has_Task is false, Decls not used
3740 -- Add discriminants if discriminated type
3743 Dis : Boolean := False;
3747 if Has_Discriminants (T) then
3751 elsif Is_Private_Type (T)
3752 and then Present (Full_View (T))
3753 and then Has_Discriminants (Full_View (T))
3756 Typ := Full_View (T);
3761 -- If the allocated object will be constrained by the
3762 -- default values for discriminants, then build a subtype
3763 -- with those defaults, and change the allocated subtype
3764 -- to that. Note that this happens in fewer cases in Ada
3767 if not Is_Constrained (Typ)
3768 and then Present (Discriminant_Default_Value
3769 (First_Discriminant (Typ)))
3770 and then (Ada_Version < Ada_2005
3772 not Has_Constrained_Partial_View (Typ))
3774 Typ := Build_Default_Subtype (Typ, N);
3775 Set_Expression (N, New_Reference_To (Typ, Loc));
3778 Discr := First_Elmt (Discriminant_Constraint (Typ));
3779 while Present (Discr) loop
3780 Nod := Node (Discr);
3781 Append (New_Copy_Tree (Node (Discr)), Args);
3783 -- AI-416: when the discriminant constraint is an
3784 -- anonymous access type make sure an accessibility
3785 -- check is inserted if necessary (3.10.2(22.q/2))
3787 if Ada_Version >= Ada_2005
3789 Ekind (Etype (Nod)) = E_Anonymous_Access_Type
3791 Apply_Accessibility_Check
3792 (Nod, Typ, Insert_Node => Nod);
3800 -- We set the allocator as analyzed so that when we analyze the
3801 -- expression actions node, we do not get an unwanted recursive
3802 -- expansion of the allocator expression.
3804 Set_Analyzed (N, True);
3805 Nod := Relocate_Node (N);
3807 -- Here is the transformation:
3809 -- output: Temp : constant ptr_T := new T;
3810 -- Init (Temp.all, ...);
3811 -- <CTRL> Attach_To_Final_List (Finalizable (Temp.all));
3812 -- <CTRL> Initialize (Finalizable (Temp.all));
3814 -- Here ptr_T is the pointer type for the allocator, and is the
3815 -- subtype of the allocator.
3818 Make_Object_Declaration (Loc,
3819 Defining_Identifier => Temp,
3820 Constant_Present => True,
3821 Object_Definition => New_Reference_To (Temp_Type, Loc),
3824 Set_Assignment_OK (Temp_Decl);
3825 Insert_Action (N, Temp_Decl, Suppress => All_Checks);
3827 Complete_Controlled_Allocation (Temp_Decl);
3829 -- If the designated type is a task type or contains tasks,
3830 -- create block to activate created tasks, and insert
3831 -- declaration for Task_Image variable ahead of call.
3833 if Has_Task (T) then
3835 L : constant List_Id := New_List;
3838 Build_Task_Allocate_Block (L, Nod, Args);
3840 Insert_List_Before (First (Declarations (Blk)), Decls);
3841 Insert_Actions (N, L);
3846 Make_Procedure_Call_Statement (Loc,
3847 Name => New_Reference_To (Init, Loc),
3848 Parameter_Associations => Args));
3851 if Needs_Finalization (T) then
3854 -- [Deep_]Initialize (Init_Arg1);
3858 (Obj_Ref => New_Copy_Tree (Init_Arg1),
3861 if Present (Associated_Collection (PtrT)) then
3863 -- Special processing for .NET/JVM, the allocated object
3864 -- is attached to the finalization collection. Generate:
3866 -- Attach (<PtrT>FC, Root_Controlled_Ptr (Init_Arg1));
3868 -- Types derived from [Limited_]Controlled are the only
3869 -- ones considered since they have fields Prev and Next.
3871 if VM_Target /= No_VM then
3872 if Is_Controlled (T) then
3875 (Obj_Ref => New_Copy_Tree (Init_Arg1),
3879 -- Default case, generate:
3881 -- Set_Finalize_Address_Ptr
3882 -- (Pool, <Finalize_Address>'Unrestricted_Access)
3884 -- Do not generate the above for CodePeer compilations
3885 -- because Finalize_Address is never built.
3887 elsif not CodePeer_Mode then
3889 Make_Set_Finalize_Address_Ptr_Call
3897 Rewrite (N, New_Reference_To (Temp, Loc));
3898 Analyze_And_Resolve (N, PtrT);
3903 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
3904 -- object that has been rewritten as a reference, we displace "this"
3905 -- to reference properly its secondary dispatch table.
3907 if Nkind (N) = N_Identifier
3908 and then Is_Interface (Dtyp)
3910 Displace_Allocator_Pointer (N);
3914 when RE_Not_Available =>
3916 end Expand_N_Allocator;
3918 -----------------------
3919 -- Expand_N_And_Then --
3920 -----------------------
3922 procedure Expand_N_And_Then (N : Node_Id)
3923 renames Expand_Short_Circuit_Operator;
3925 ------------------------------
3926 -- Expand_N_Case_Expression --
3927 ------------------------------
3929 procedure Expand_N_Case_Expression (N : Node_Id) is
3930 Loc : constant Source_Ptr := Sloc (N);
3931 Typ : constant Entity_Id := Etype (N);
3943 -- case X is when A => AX, when B => BX ...
3958 -- However, this expansion is wrong for limited types, and also
3959 -- wrong for unconstrained types (since the bounds may not be the
3960 -- same in all branches). Furthermore it involves an extra copy
3961 -- for large objects. So we take care of this by using the following
3962 -- modified expansion for non-scalar types:
3965 -- type Pnn is access all typ;
3969 -- T := AX'Unrestricted_Access;
3971 -- T := BX'Unrestricted_Access;
3977 Make_Case_Statement (Loc,
3978 Expression => Expression (N),
3979 Alternatives => New_List);
3981 Actions := New_List;
3985 if Is_Scalar_Type (Typ) then
3989 Pnn := Make_Temporary (Loc, 'P');
3991 Make_Full_Type_Declaration (Loc,
3992 Defining_Identifier => Pnn,
3994 Make_Access_To_Object_Definition (Loc,
3995 All_Present => True,
3996 Subtype_Indication =>
3997 New_Reference_To (Typ, Loc))));
4001 Tnn := Make_Temporary (Loc, 'T');
4003 Make_Object_Declaration (Loc,
4004 Defining_Identifier => Tnn,
4005 Object_Definition => New_Occurrence_Of (Ttyp, Loc)));
4007 -- Now process the alternatives
4009 Alt := First (Alternatives (N));
4010 while Present (Alt) loop
4012 Aexp : Node_Id := Expression (Alt);
4013 Aloc : constant Source_Ptr := Sloc (Aexp);
4016 -- Propagate declarations inserted in the node by Insert_Actions
4017 -- (for example, temporaries generated to remove side effects).
4019 Append_List_To (Actions, Sinfo.Actions (Alt));
4021 if not Is_Scalar_Type (Typ) then
4023 Make_Attribute_Reference (Aloc,
4024 Prefix => Relocate_Node (Aexp),
4025 Attribute_Name => Name_Unrestricted_Access);
4029 (Alternatives (Cstmt),
4030 Make_Case_Statement_Alternative (Sloc (Alt),
4031 Discrete_Choices => Discrete_Choices (Alt),
4032 Statements => New_List (
4033 Make_Assignment_Statement (Aloc,
4034 Name => New_Occurrence_Of (Tnn, Loc),
4035 Expression => Aexp))));
4041 Append_To (Actions, Cstmt);
4043 -- Construct and return final expression with actions
4045 if Is_Scalar_Type (Typ) then
4046 Fexp := New_Occurrence_Of (Tnn, Loc);
4049 Make_Explicit_Dereference (Loc,
4050 Prefix => New_Occurrence_Of (Tnn, Loc));
4054 Make_Expression_With_Actions (Loc,
4056 Actions => Actions));
4058 Analyze_And_Resolve (N, Typ);
4059 end Expand_N_Case_Expression;
4061 -------------------------------------
4062 -- Expand_N_Conditional_Expression --
4063 -------------------------------------
4065 -- Deal with limited types and expression actions
4067 procedure Expand_N_Conditional_Expression (N : Node_Id) is
4068 Loc : constant Source_Ptr := Sloc (N);
4069 Cond : constant Node_Id := First (Expressions (N));
4070 Thenx : constant Node_Id := Next (Cond);
4071 Elsex : constant Node_Id := Next (Thenx);
4072 Typ : constant Entity_Id := Etype (N);
4083 -- Fold at compile time if condition known. We have already folded
4084 -- static conditional expressions, but it is possible to fold any
4085 -- case in which the condition is known at compile time, even though
4086 -- the result is non-static.
4088 -- Note that we don't do the fold of such cases in Sem_Elab because
4089 -- it can cause infinite loops with the expander adding a conditional
4090 -- expression, and Sem_Elab circuitry removing it repeatedly.
4092 if Compile_Time_Known_Value (Cond) then
4093 if Is_True (Expr_Value (Cond)) then
4095 Actions := Then_Actions (N);
4098 Actions := Else_Actions (N);
4103 if Present (Actions) then
4105 -- If we are not allowed to use Expression_With_Actions, just
4106 -- skip the optimization, it is not critical for correctness.
4108 if not Use_Expression_With_Actions then
4109 goto Skip_Optimization;
4113 Make_Expression_With_Actions (Loc,
4114 Expression => Relocate_Node (Expr),
4115 Actions => Actions));
4116 Analyze_And_Resolve (N, Typ);
4119 Rewrite (N, Relocate_Node (Expr));
4122 -- Note that the result is never static (legitimate cases of static
4123 -- conditional expressions were folded in Sem_Eval).
4125 Set_Is_Static_Expression (N, False);
4129 <<Skip_Optimization>>
4131 -- If the type is limited or unconstrained, we expand as follows to
4132 -- avoid any possibility of improper copies.
4134 -- Note: it may be possible to avoid this special processing if the
4135 -- back end uses its own mechanisms for handling by-reference types ???
4137 -- type Ptr is access all Typ;
4141 -- Cnn := then-expr'Unrestricted_Access;
4144 -- Cnn := else-expr'Unrestricted_Access;
4147 -- and replace the conditional expression by a reference to Cnn.all.
4149 -- This special case can be skipped if the back end handles limited
4150 -- types properly and ensures that no incorrect copies are made.
4152 if Is_By_Reference_Type (Typ)
4153 and then not Back_End_Handles_Limited_Types
4155 Cnn := Make_Temporary (Loc, 'C', N);
4158 Make_Full_Type_Declaration (Loc,
4159 Defining_Identifier =>
4160 Make_Temporary (Loc, 'A'),
4162 Make_Access_To_Object_Definition (Loc,
4163 All_Present => True,
4164 Subtype_Indication => New_Reference_To (Typ, Loc)));
4166 Insert_Action (N, P_Decl);
4169 Make_Object_Declaration (Loc,
4170 Defining_Identifier => Cnn,
4171 Object_Definition =>
4172 New_Occurrence_Of (Defining_Identifier (P_Decl), Loc));
4175 Make_Implicit_If_Statement (N,
4176 Condition => Relocate_Node (Cond),
4178 Then_Statements => New_List (
4179 Make_Assignment_Statement (Sloc (Thenx),
4180 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4182 Make_Attribute_Reference (Loc,
4183 Attribute_Name => Name_Unrestricted_Access,
4184 Prefix => Relocate_Node (Thenx)))),
4186 Else_Statements => New_List (
4187 Make_Assignment_Statement (Sloc (Elsex),
4188 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4190 Make_Attribute_Reference (Loc,
4191 Attribute_Name => Name_Unrestricted_Access,
4192 Prefix => Relocate_Node (Elsex)))));
4195 Make_Explicit_Dereference (Loc,
4196 Prefix => New_Occurrence_Of (Cnn, Loc));
4198 -- For other types, we only need to expand if there are other actions
4199 -- associated with either branch.
4201 elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
4203 -- We have two approaches to handling this. If we are allowed to use
4204 -- N_Expression_With_Actions, then we can just wrap the actions into
4205 -- the appropriate expression.
4207 if Use_Expression_With_Actions then
4208 if Present (Then_Actions (N)) then
4210 Make_Expression_With_Actions (Sloc (Thenx),
4211 Actions => Then_Actions (N),
4212 Expression => Relocate_Node (Thenx)));
4213 Set_Then_Actions (N, No_List);
4214 Analyze_And_Resolve (Thenx, Typ);
4217 if Present (Else_Actions (N)) then
4219 Make_Expression_With_Actions (Sloc (Elsex),
4220 Actions => Else_Actions (N),
4221 Expression => Relocate_Node (Elsex)));
4222 Set_Else_Actions (N, No_List);
4223 Analyze_And_Resolve (Elsex, Typ);
4228 -- if we can't use N_Expression_With_Actions nodes, then we insert
4229 -- the following sequence of actions (using Insert_Actions):
4234 -- Cnn := then-expr;
4240 -- and replace the conditional expression by a reference to Cnn
4243 Cnn := Make_Temporary (Loc, 'C', N);
4246 Make_Object_Declaration (Loc,
4247 Defining_Identifier => Cnn,
4248 Object_Definition => New_Occurrence_Of (Typ, Loc));
4251 Make_Implicit_If_Statement (N,
4252 Condition => Relocate_Node (Cond),
4254 Then_Statements => New_List (
4255 Make_Assignment_Statement (Sloc (Thenx),
4256 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4257 Expression => Relocate_Node (Thenx))),
4259 Else_Statements => New_List (
4260 Make_Assignment_Statement (Sloc (Elsex),
4261 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4262 Expression => Relocate_Node (Elsex))));
4264 Set_Assignment_OK (Name (First (Then_Statements (New_If))));
4265 Set_Assignment_OK (Name (First (Else_Statements (New_If))));
4267 New_N := New_Occurrence_Of (Cnn, Loc);
4270 -- If no actions then no expansion needed, gigi will handle it using
4271 -- the same approach as a C conditional expression.
4277 -- Fall through here for either the limited expansion, or the case of
4278 -- inserting actions for non-limited types. In both these cases, we must
4279 -- move the SLOC of the parent If statement to the newly created one and
4280 -- change it to the SLOC of the expression which, after expansion, will
4281 -- correspond to what is being evaluated.
4283 if Present (Parent (N))
4284 and then Nkind (Parent (N)) = N_If_Statement
4286 Set_Sloc (New_If, Sloc (Parent (N)));
4287 Set_Sloc (Parent (N), Loc);
4290 -- Make sure Then_Actions and Else_Actions are appropriately moved
4291 -- to the new if statement.
4293 if Present (Then_Actions (N)) then
4295 (First (Then_Statements (New_If)), Then_Actions (N));
4298 if Present (Else_Actions (N)) then
4300 (First (Else_Statements (New_If)), Else_Actions (N));
4303 Insert_Action (N, Decl);
4304 Insert_Action (N, New_If);
4306 Analyze_And_Resolve (N, Typ);
4307 end Expand_N_Conditional_Expression;
4309 -----------------------------------
4310 -- Expand_N_Explicit_Dereference --
4311 -----------------------------------
4313 procedure Expand_N_Explicit_Dereference (N : Node_Id) is
4315 -- Insert explicit dereference call for the checked storage pool case
4317 Insert_Dereference_Action (Prefix (N));
4318 end Expand_N_Explicit_Dereference;
4320 --------------------------------------
4321 -- Expand_N_Expression_With_Actions --
4322 --------------------------------------
4324 procedure Expand_N_Expression_With_Actions (N : Node_Id) is
4326 procedure Process_Transient_Object (Decl : Node_Id);
4327 -- Given the declaration of a controlled transient declared inside the
4328 -- Actions list of an Expression_With_Actions, generate all necessary
4329 -- types and hooks in order to properly finalize the transient. This
4330 -- mechanism works in conjunction with Build_Finalizer.
4332 ------------------------------
4333 -- Process_Transient_Object --
4334 ------------------------------
4336 procedure Process_Transient_Object (Decl : Node_Id) is
4337 Ins_Nod : constant Node_Id := Parent (N);
4338 -- To avoid the insertion of generated code in the list of Actions,
4339 -- Insert_Action must look at the parent field of the EWA.
4341 Loc : constant Source_Ptr := Sloc (Decl);
4342 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
4343 Obj_Typ : constant Entity_Id := Etype (Obj_Id);
4344 Desig_Typ : Entity_Id;
4348 Temp_Decl : Node_Id;
4352 -- Step 1: Create the access type which provides a reference to
4353 -- the transient object.
4355 if Is_Access_Type (Obj_Typ) then
4356 Desig_Typ := Directly_Designated_Type (Obj_Typ);
4358 Desig_Typ := Obj_Typ;
4362 -- Ann : access [all] <Desig_Typ>;
4364 Ptr_Id := Make_Temporary (Loc, 'A');
4367 Make_Full_Type_Declaration (Loc,
4368 Defining_Identifier => Ptr_Id,
4370 Make_Access_To_Object_Definition (Loc,
4372 Ekind (Obj_Typ) = E_General_Access_Type,
4373 Subtype_Indication => New_Reference_To (Desig_Typ, Loc)));
4375 Insert_Action (Ins_Nod, Ptr_Decl);
4378 -- Step 2: Create a temporary which acts as a hook to the transient
4379 -- object. Generate:
4381 -- Temp : Ptr_Id := null;
4383 Temp_Id := Make_Temporary (Loc, 'T');
4386 Make_Object_Declaration (Loc,
4387 Defining_Identifier => Temp_Id,
4388 Object_Definition => New_Reference_To (Ptr_Id, Loc));
4390 Insert_Action (Ins_Nod, Temp_Decl);
4391 Analyze (Temp_Decl);
4393 -- Mark this temporary as created for the purposes of "exporting" the
4394 -- transient declaration out of the Actions list. This signals the
4395 -- machinery in Build_Finalizer to recognize this special case.
4397 Set_Return_Flag_Or_Transient_Decl (Temp_Id, Decl);
4399 -- Step 3: "Hook" the transient object to the temporary
4401 if Is_Access_Type (Obj_Typ) then
4402 Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc));
4405 Make_Attribute_Reference (Loc,
4406 Prefix => New_Reference_To (Obj_Id, Loc),
4407 Attribute_Name => Name_Unrestricted_Access);
4411 -- Temp := Ptr_Id (Obj_Id);
4413 -- Temp := Obj_Id'Unrestricted_Access;
4415 Insert_After_And_Analyze (Decl,
4416 Make_Assignment_Statement (Loc,
4417 Name => New_Reference_To (Temp_Id, Loc),
4418 Expression => Expr));
4419 end Process_Transient_Object;
4423 -- Start of processing for Expand_N_Expression_With_Actions
4426 Decl := First (Actions (N));
4427 while Present (Decl) loop
4428 if Nkind (Decl) = N_Object_Declaration
4429 and then Is_Finalizable_Transient (Decl, N)
4431 Process_Transient_Object (Decl);
4436 end Expand_N_Expression_With_Actions;
4442 procedure Expand_N_In (N : Node_Id) is
4443 Loc : constant Source_Ptr := Sloc (N);
4444 Restyp : constant Entity_Id := Etype (N);
4445 Lop : constant Node_Id := Left_Opnd (N);
4446 Rop : constant Node_Id := Right_Opnd (N);
4447 Static : constant Boolean := Is_OK_Static_Expression (N);
4452 procedure Expand_Set_Membership;
4453 -- For each choice we create a simple equality or membership test.
4454 -- The whole membership is rewritten connecting these with OR ELSE.
4456 ---------------------------
4457 -- Expand_Set_Membership --
4458 ---------------------------
4460 procedure Expand_Set_Membership is
4464 function Make_Cond (Alt : Node_Id) return Node_Id;
4465 -- If the alternative is a subtype mark, create a simple membership
4466 -- test. Otherwise create an equality test for it.
4472 function Make_Cond (Alt : Node_Id) return Node_Id is
4474 L : constant Node_Id := New_Copy (Lop);
4475 R : constant Node_Id := Relocate_Node (Alt);
4478 if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
4479 or else Nkind (Alt) = N_Range
4482 Make_In (Sloc (Alt),
4487 Make_Op_Eq (Sloc (Alt),
4495 -- Start of processing for Expand_Set_Membership
4498 Alt := Last (Alternatives (N));
4499 Res := Make_Cond (Alt);
4502 while Present (Alt) loop
4504 Make_Or_Else (Sloc (Alt),
4505 Left_Opnd => Make_Cond (Alt),
4511 Analyze_And_Resolve (N, Standard_Boolean);
4512 end Expand_Set_Membership;
4514 procedure Substitute_Valid_Check;
4515 -- Replaces node N by Lop'Valid. This is done when we have an explicit
4516 -- test for the left operand being in range of its subtype.
4518 ----------------------------
4519 -- Substitute_Valid_Check --
4520 ----------------------------
4522 procedure Substitute_Valid_Check is
4525 Make_Attribute_Reference (Loc,
4526 Prefix => Relocate_Node (Lop),
4527 Attribute_Name => Name_Valid));
4529 Analyze_And_Resolve (N, Restyp);
4531 Error_Msg_N ("?explicit membership test may be optimized away", N);
4532 Error_Msg_N -- CODEFIX
4533 ("\?use ''Valid attribute instead", N);
4535 end Substitute_Valid_Check;
4537 -- Start of processing for Expand_N_In
4540 -- If set membership case, expand with separate procedure
4542 if Present (Alternatives (N)) then
4543 Remove_Side_Effects (Lop);
4544 Expand_Set_Membership;
4548 -- Not set membership, proceed with expansion
4550 Ltyp := Etype (Left_Opnd (N));
4551 Rtyp := Etype (Right_Opnd (N));
4553 -- Check case of explicit test for an expression in range of its
4554 -- subtype. This is suspicious usage and we replace it with a 'Valid
4555 -- test and give a warning. For floating point types however, this is a
4556 -- standard way to check for finite numbers, and using 'Valid would
4557 -- typically be a pessimization. Also skip this test for predicated
4558 -- types, since it is perfectly reasonable to check if a value meets
4561 if Is_Scalar_Type (Ltyp)
4562 and then not Is_Floating_Point_Type (Ltyp)
4563 and then Nkind (Rop) in N_Has_Entity
4564 and then Ltyp = Entity (Rop)
4565 and then Comes_From_Source (N)
4566 and then VM_Target = No_VM
4567 and then not (Is_Discrete_Type (Ltyp)
4568 and then Present (Predicate_Function (Ltyp)))
4570 Substitute_Valid_Check;
4574 -- Do validity check on operands
4576 if Validity_Checks_On and Validity_Check_Operands then
4577 Ensure_Valid (Left_Opnd (N));
4578 Validity_Check_Range (Right_Opnd (N));
4581 -- Case of explicit range
4583 if Nkind (Rop) = N_Range then
4585 Lo : constant Node_Id := Low_Bound (Rop);
4586 Hi : constant Node_Id := High_Bound (Rop);
4588 Lo_Orig : constant Node_Id := Original_Node (Lo);
4589 Hi_Orig : constant Node_Id := Original_Node (Hi);
4591 Lcheck : Compare_Result;
4592 Ucheck : Compare_Result;
4594 Warn1 : constant Boolean :=
4595 Constant_Condition_Warnings
4596 and then Comes_From_Source (N)
4597 and then not In_Instance;
4598 -- This must be true for any of the optimization warnings, we
4599 -- clearly want to give them only for source with the flag on. We
4600 -- also skip these warnings in an instance since it may be the
4601 -- case that different instantiations have different ranges.
4603 Warn2 : constant Boolean :=
4605 and then Nkind (Original_Node (Rop)) = N_Range
4606 and then Is_Integer_Type (Etype (Lo));
4607 -- For the case where only one bound warning is elided, we also
4608 -- insist on an explicit range and an integer type. The reason is
4609 -- that the use of enumeration ranges including an end point is
4610 -- common, as is the use of a subtype name, one of whose bounds is
4611 -- the same as the type of the expression.
4614 -- If test is explicit x'First .. x'Last, replace by valid check
4616 -- Could use some individual comments for this complex test ???
4618 if Is_Scalar_Type (Ltyp)
4619 and then Nkind (Lo_Orig) = N_Attribute_Reference
4620 and then Attribute_Name (Lo_Orig) = Name_First
4621 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
4622 and then Entity (Prefix (Lo_Orig)) = Ltyp
4623 and then Nkind (Hi_Orig) = N_Attribute_Reference
4624 and then Attribute_Name (Hi_Orig) = Name_Last
4625 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
4626 and then Entity (Prefix (Hi_Orig)) = Ltyp
4627 and then Comes_From_Source (N)
4628 and then VM_Target = No_VM
4630 Substitute_Valid_Check;
4634 -- If bounds of type are known at compile time, and the end points
4635 -- are known at compile time and identical, this is another case
4636 -- for substituting a valid test. We only do this for discrete
4637 -- types, since it won't arise in practice for float types.
4639 if Comes_From_Source (N)
4640 and then Is_Discrete_Type (Ltyp)
4641 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
4642 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
4643 and then Compile_Time_Known_Value (Lo)
4644 and then Compile_Time_Known_Value (Hi)
4645 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
4646 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
4648 -- Kill warnings in instances, since they may be cases where we
4649 -- have a test in the generic that makes sense with some types
4650 -- and not with other types.
4652 and then not In_Instance
4654 Substitute_Valid_Check;
4658 -- If we have an explicit range, do a bit of optimization based on
4659 -- range analysis (we may be able to kill one or both checks).
4661 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
4662 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
4664 -- If either check is known to fail, replace result by False since
4665 -- the other check does not matter. Preserve the static flag for
4666 -- legality checks, because we are constant-folding beyond RM 4.9.
4668 if Lcheck = LT or else Ucheck = GT then
4670 Error_Msg_N ("?range test optimized away", N);
4671 Error_Msg_N ("\?value is known to be out of range", N);
4674 Rewrite (N, New_Reference_To (Standard_False, Loc));
4675 Analyze_And_Resolve (N, Restyp);
4676 Set_Is_Static_Expression (N, Static);
4679 -- If both checks are known to succeed, replace result by True,
4680 -- since we know we are in range.
4682 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4684 Error_Msg_N ("?range test optimized away", N);
4685 Error_Msg_N ("\?value is known to be in range", N);
4688 Rewrite (N, New_Reference_To (Standard_True, Loc));
4689 Analyze_And_Resolve (N, Restyp);
4690 Set_Is_Static_Expression (N, Static);
4693 -- If lower bound check succeeds and upper bound check is not
4694 -- known to succeed or fail, then replace the range check with
4695 -- a comparison against the upper bound.
4697 elsif Lcheck in Compare_GE then
4698 if Warn2 and then not In_Instance then
4699 Error_Msg_N ("?lower bound test optimized away", Lo);
4700 Error_Msg_N ("\?value is known to be in range", Lo);
4706 Right_Opnd => High_Bound (Rop)));
4707 Analyze_And_Resolve (N, Restyp);
4710 -- If upper bound check succeeds and lower bound check is not
4711 -- known to succeed or fail, then replace the range check with
4712 -- a comparison against the lower bound.
4714 elsif Ucheck in Compare_LE then
4715 if Warn2 and then not In_Instance then
4716 Error_Msg_N ("?upper bound test optimized away", Hi);
4717 Error_Msg_N ("\?value is known to be in range", Hi);
4723 Right_Opnd => Low_Bound (Rop)));
4724 Analyze_And_Resolve (N, Restyp);
4728 -- We couldn't optimize away the range check, but there is one
4729 -- more issue. If we are checking constant conditionals, then we
4730 -- see if we can determine the outcome assuming everything is
4731 -- valid, and if so give an appropriate warning.
4733 if Warn1 and then not Assume_No_Invalid_Values then
4734 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4735 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4737 -- Result is out of range for valid value
4739 if Lcheck = LT or else Ucheck = GT then
4741 ("?value can only be in range if it is invalid", N);
4743 -- Result is in range for valid value
4745 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4747 ("?value can only be out of range if it is invalid", N);
4749 -- Lower bound check succeeds if value is valid
4751 elsif Warn2 and then Lcheck in Compare_GE then
4753 ("?lower bound check only fails if it is invalid", Lo);
4755 -- Upper bound check succeeds if value is valid
4757 elsif Warn2 and then Ucheck in Compare_LE then
4759 ("?upper bound check only fails for invalid values", Hi);
4764 -- For all other cases of an explicit range, nothing to be done
4768 -- Here right operand is a subtype mark
4772 Typ : Entity_Id := Etype (Rop);
4773 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4774 Cond : Node_Id := Empty;
4776 Obj : Node_Id := Lop;
4777 SCIL_Node : Node_Id;
4780 Remove_Side_Effects (Obj);
4782 -- For tagged type, do tagged membership operation
4784 if Is_Tagged_Type (Typ) then
4786 -- No expansion will be performed when VM_Target, as the VM
4787 -- back-ends will handle the membership tests directly (tags
4788 -- are not explicitly represented in Java objects, so the
4789 -- normal tagged membership expansion is not what we want).
4791 if Tagged_Type_Expansion then
4792 Tagged_Membership (N, SCIL_Node, New_N);
4794 Analyze_And_Resolve (N, Restyp);
4796 -- Update decoration of relocated node referenced by the
4799 if Generate_SCIL and then Present (SCIL_Node) then
4800 Set_SCIL_Node (N, SCIL_Node);
4806 -- If type is scalar type, rewrite as x in t'First .. t'Last.
4807 -- This reason we do this is that the bounds may have the wrong
4808 -- type if they come from the original type definition. Also this
4809 -- way we get all the processing above for an explicit range.
4811 -- Don't do this for predicated types, since in this case we
4812 -- want to check the predicate!
4814 elsif Is_Scalar_Type (Typ) then
4815 if No (Predicate_Function (Typ)) then
4819 Make_Attribute_Reference (Loc,
4820 Attribute_Name => Name_First,
4821 Prefix => New_Reference_To (Typ, Loc)),
4824 Make_Attribute_Reference (Loc,
4825 Attribute_Name => Name_Last,
4826 Prefix => New_Reference_To (Typ, Loc))));
4827 Analyze_And_Resolve (N, Restyp);
4832 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4833 -- a membership test if the subtype mark denotes a constrained
4834 -- Unchecked_Union subtype and the expression lacks inferable
4837 elsif Is_Unchecked_Union (Base_Type (Typ))
4838 and then Is_Constrained (Typ)
4839 and then not Has_Inferable_Discriminants (Lop)
4842 Make_Raise_Program_Error (Loc,
4843 Reason => PE_Unchecked_Union_Restriction));
4845 -- Prevent Gigi from generating incorrect code by rewriting the
4848 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
4852 -- Here we have a non-scalar type
4855 Typ := Designated_Type (Typ);
4858 if not Is_Constrained (Typ) then
4859 Rewrite (N, New_Reference_To (Standard_True, Loc));
4860 Analyze_And_Resolve (N, Restyp);
4862 -- For the constrained array case, we have to check the subscripts
4863 -- for an exact match if the lengths are non-zero (the lengths
4864 -- must match in any case).
4866 elsif Is_Array_Type (Typ) then
4867 Check_Subscripts : declare
4868 function Build_Attribute_Reference
4871 Dim : Nat) return Node_Id;
4872 -- Build attribute reference E'Nam (Dim)
4874 -------------------------------
4875 -- Build_Attribute_Reference --
4876 -------------------------------
4878 function Build_Attribute_Reference
4881 Dim : Nat) return Node_Id
4885 Make_Attribute_Reference (Loc,
4887 Attribute_Name => Nam,
4888 Expressions => New_List (
4889 Make_Integer_Literal (Loc, Dim)));
4890 end Build_Attribute_Reference;
4892 -- Start of processing for Check_Subscripts
4895 for J in 1 .. Number_Dimensions (Typ) loop
4896 Evolve_And_Then (Cond,
4899 Build_Attribute_Reference
4900 (Duplicate_Subexpr_No_Checks (Obj),
4903 Build_Attribute_Reference
4904 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
4906 Evolve_And_Then (Cond,
4909 Build_Attribute_Reference
4910 (Duplicate_Subexpr_No_Checks (Obj),
4913 Build_Attribute_Reference
4914 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
4923 Right_Opnd => Make_Null (Loc)),
4924 Right_Opnd => Cond);
4928 Analyze_And_Resolve (N, Restyp);
4929 end Check_Subscripts;
4931 -- These are the cases where constraint checks may be required,
4932 -- e.g. records with possible discriminants
4935 -- Expand the test into a series of discriminant comparisons.
4936 -- The expression that is built is the negation of the one that
4937 -- is used for checking discriminant constraints.
4939 Obj := Relocate_Node (Left_Opnd (N));
4941 if Has_Discriminants (Typ) then
4942 Cond := Make_Op_Not (Loc,
4943 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
4946 Cond := Make_Or_Else (Loc,
4950 Right_Opnd => Make_Null (Loc)),
4951 Right_Opnd => Cond);
4955 Cond := New_Occurrence_Of (Standard_True, Loc);
4959 Analyze_And_Resolve (N, Restyp);
4964 -- At this point, we have done the processing required for the basic
4965 -- membership test, but not yet dealt with the predicate.
4969 -- If a predicate is present, then we do the predicate test, but we
4970 -- most certainly want to omit this if we are within the predicate
4971 -- function itself, since otherwise we have an infinite recursion!
4974 PFunc : constant Entity_Id := Predicate_Function (Rtyp);
4978 and then Current_Scope /= PFunc
4982 Left_Opnd => Relocate_Node (N),
4983 Right_Opnd => Make_Predicate_Call (Rtyp, Lop)));
4985 -- Analyze new expression, mark left operand as analyzed to
4986 -- avoid infinite recursion adding predicate calls.
4988 Set_Analyzed (Left_Opnd (N));
4989 Analyze_And_Resolve (N, Standard_Boolean);
4991 -- All done, skip attempt at compile time determination of result
4998 --------------------------------
4999 -- Expand_N_Indexed_Component --
5000 --------------------------------
5002 procedure Expand_N_Indexed_Component (N : Node_Id) is
5003 Loc : constant Source_Ptr := Sloc (N);
5004 Typ : constant Entity_Id := Etype (N);
5005 P : constant Node_Id := Prefix (N);
5006 T : constant Entity_Id := Etype (P);
5009 -- A special optimization, if we have an indexed component that is
5010 -- selecting from a slice, then we can eliminate the slice, since, for
5011 -- example, x (i .. j)(k) is identical to x(k). The only difference is
5012 -- the range check required by the slice. The range check for the slice
5013 -- itself has already been generated. The range check for the
5014 -- subscripting operation is ensured by converting the subject to
5015 -- the subtype of the slice.
5017 -- This optimization not only generates better code, avoiding slice
5018 -- messing especially in the packed case, but more importantly bypasses
5019 -- some problems in handling this peculiar case, for example, the issue
5020 -- of dealing specially with object renamings.
5022 if Nkind (P) = N_Slice then
5024 Make_Indexed_Component (Loc,
5025 Prefix => Prefix (P),
5026 Expressions => New_List (
5028 (Etype (First_Index (Etype (P))),
5029 First (Expressions (N))))));
5030 Analyze_And_Resolve (N, Typ);
5034 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
5035 -- function, then additional actuals must be passed.
5037 if Ada_Version >= Ada_2005
5038 and then Is_Build_In_Place_Function_Call (P)
5040 Make_Build_In_Place_Call_In_Anonymous_Context (P);
5043 -- If the prefix is an access type, then we unconditionally rewrite if
5044 -- as an explicit dereference. This simplifies processing for several
5045 -- cases, including packed array cases and certain cases in which checks
5046 -- must be generated. We used to try to do this only when it was
5047 -- necessary, but it cleans up the code to do it all the time.
5049 if Is_Access_Type (T) then
5050 Insert_Explicit_Dereference (P);
5051 Analyze_And_Resolve (P, Designated_Type (T));
5054 -- Generate index and validity checks
5056 Generate_Index_Checks (N);
5058 if Validity_Checks_On and then Validity_Check_Subscripts then
5059 Apply_Subscript_Validity_Checks (N);
5062 -- All done for the non-packed case
5064 if not Is_Packed (Etype (Prefix (N))) then
5068 -- For packed arrays that are not bit-packed (i.e. the case of an array
5069 -- with one or more index types with a non-contiguous enumeration type),
5070 -- we can always use the normal packed element get circuit.
5072 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
5073 Expand_Packed_Element_Reference (N);
5077 -- For a reference to a component of a bit packed array, we have to
5078 -- convert it to a reference to the corresponding Packed_Array_Type.
5079 -- We only want to do this for simple references, and not for:
5081 -- Left side of assignment, or prefix of left side of assignment, or
5082 -- prefix of the prefix, to handle packed arrays of packed arrays,
5083 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
5085 -- Renaming objects in renaming associations
5086 -- This case is handled when a use of the renamed variable occurs
5088 -- Actual parameters for a procedure call
5089 -- This case is handled in Exp_Ch6.Expand_Actuals
5091 -- The second expression in a 'Read attribute reference
5093 -- The prefix of an address or bit or size attribute reference
5095 -- The following circuit detects these exceptions
5098 Child : Node_Id := N;
5099 Parnt : Node_Id := Parent (N);
5103 if Nkind (Parnt) = N_Unchecked_Expression then
5106 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
5107 N_Procedure_Call_Statement)
5108 or else (Nkind (Parnt) = N_Parameter_Association
5110 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
5114 elsif Nkind (Parnt) = N_Attribute_Reference
5115 and then (Attribute_Name (Parnt) = Name_Address
5117 Attribute_Name (Parnt) = Name_Bit
5119 Attribute_Name (Parnt) = Name_Size)
5120 and then Prefix (Parnt) = Child
5124 elsif Nkind (Parnt) = N_Assignment_Statement
5125 and then Name (Parnt) = Child
5129 -- If the expression is an index of an indexed component, it must
5130 -- be expanded regardless of context.
5132 elsif Nkind (Parnt) = N_Indexed_Component
5133 and then Child /= Prefix (Parnt)
5135 Expand_Packed_Element_Reference (N);
5138 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
5139 and then Name (Parent (Parnt)) = Parnt
5143 elsif Nkind (Parnt) = N_Attribute_Reference
5144 and then Attribute_Name (Parnt) = Name_Read
5145 and then Next (First (Expressions (Parnt))) = Child
5149 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
5150 and then Prefix (Parnt) = Child
5155 Expand_Packed_Element_Reference (N);
5159 -- Keep looking up tree for unchecked expression, or if we are the
5160 -- prefix of a possible assignment left side.
5163 Parnt := Parent (Child);
5166 end Expand_N_Indexed_Component;
5168 ---------------------
5169 -- Expand_N_Not_In --
5170 ---------------------
5172 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
5173 -- can be done. This avoids needing to duplicate this expansion code.
5175 procedure Expand_N_Not_In (N : Node_Id) is
5176 Loc : constant Source_Ptr := Sloc (N);
5177 Typ : constant Entity_Id := Etype (N);
5178 Cfs : constant Boolean := Comes_From_Source (N);
5185 Left_Opnd => Left_Opnd (N),
5186 Right_Opnd => Right_Opnd (N))));
5188 -- If this is a set membership, preserve list of alternatives
5190 Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
5192 -- We want this to appear as coming from source if original does (see
5193 -- transformations in Expand_N_In).
5195 Set_Comes_From_Source (N, Cfs);
5196 Set_Comes_From_Source (Right_Opnd (N), Cfs);
5198 -- Now analyze transformed node
5200 Analyze_And_Resolve (N, Typ);
5201 end Expand_N_Not_In;
5207 -- The only replacement required is for the case of a null of a type that
5208 -- is an access to protected subprogram, or a subtype thereof. We represent
5209 -- such access values as a record, and so we must replace the occurrence of
5210 -- null by the equivalent record (with a null address and a null pointer in
5211 -- it), so that the backend creates the proper value.
5213 procedure Expand_N_Null (N : Node_Id) is
5214 Loc : constant Source_Ptr := Sloc (N);
5215 Typ : constant Entity_Id := Base_Type (Etype (N));
5219 if Is_Access_Protected_Subprogram_Type (Typ) then
5221 Make_Aggregate (Loc,
5222 Expressions => New_List (
5223 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
5227 Analyze_And_Resolve (N, Equivalent_Type (Typ));
5229 -- For subsequent semantic analysis, the node must retain its type.
5230 -- Gigi in any case replaces this type by the corresponding record
5231 -- type before processing the node.
5237 when RE_Not_Available =>
5241 ---------------------
5242 -- Expand_N_Op_Abs --
5243 ---------------------
5245 procedure Expand_N_Op_Abs (N : Node_Id) is
5246 Loc : constant Source_Ptr := Sloc (N);
5247 Expr : constant Node_Id := Right_Opnd (N);
5250 Unary_Op_Validity_Checks (N);
5252 -- Deal with software overflow checking
5254 if not Backend_Overflow_Checks_On_Target
5255 and then Is_Signed_Integer_Type (Etype (N))
5256 and then Do_Overflow_Check (N)
5258 -- The only case to worry about is when the argument is equal to the
5259 -- largest negative number, so what we do is to insert the check:
5261 -- [constraint_error when Expr = typ'Base'First]
5263 -- with the usual Duplicate_Subexpr use coding for expr
5266 Make_Raise_Constraint_Error (Loc,
5269 Left_Opnd => Duplicate_Subexpr (Expr),
5271 Make_Attribute_Reference (Loc,
5273 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
5274 Attribute_Name => Name_First)),
5275 Reason => CE_Overflow_Check_Failed));
5278 -- Vax floating-point types case
5280 if Vax_Float (Etype (N)) then
5281 Expand_Vax_Arith (N);
5283 end Expand_N_Op_Abs;
5285 ---------------------
5286 -- Expand_N_Op_Add --
5287 ---------------------
5289 procedure Expand_N_Op_Add (N : Node_Id) is
5290 Typ : constant Entity_Id := Etype (N);
5293 Binary_Op_Validity_Checks (N);
5295 -- N + 0 = 0 + N = N for integer types
5297 if Is_Integer_Type (Typ) then
5298 if Compile_Time_Known_Value (Right_Opnd (N))
5299 and then Expr_Value (Right_Opnd (N)) = Uint_0
5301 Rewrite (N, Left_Opnd (N));
5304 elsif Compile_Time_Known_Value (Left_Opnd (N))
5305 and then Expr_Value (Left_Opnd (N)) = Uint_0
5307 Rewrite (N, Right_Opnd (N));
5312 -- Arithmetic overflow checks for signed integer/fixed point types
5314 if Is_Signed_Integer_Type (Typ)
5315 or else Is_Fixed_Point_Type (Typ)
5317 Apply_Arithmetic_Overflow_Check (N);
5320 -- Vax floating-point types case
5322 elsif Vax_Float (Typ) then
5323 Expand_Vax_Arith (N);
5325 end Expand_N_Op_Add;
5327 ---------------------
5328 -- Expand_N_Op_And --
5329 ---------------------
5331 procedure Expand_N_Op_And (N : Node_Id) is
5332 Typ : constant Entity_Id := Etype (N);
5335 Binary_Op_Validity_Checks (N);
5337 if Is_Array_Type (Etype (N)) then
5338 Expand_Boolean_Operator (N);
5340 elsif Is_Boolean_Type (Etype (N)) then
5342 -- Replace AND by AND THEN if Short_Circuit_And_Or active and the
5343 -- type is standard Boolean (do not mess with AND that uses a non-
5344 -- standard Boolean type, because something strange is going on).
5346 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
5348 Make_And_Then (Sloc (N),
5349 Left_Opnd => Relocate_Node (Left_Opnd (N)),
5350 Right_Opnd => Relocate_Node (Right_Opnd (N))));
5351 Analyze_And_Resolve (N, Typ);
5353 -- Otherwise, adjust conditions
5356 Adjust_Condition (Left_Opnd (N));
5357 Adjust_Condition (Right_Opnd (N));
5358 Set_Etype (N, Standard_Boolean);
5359 Adjust_Result_Type (N, Typ);
5362 elsif Is_Intrinsic_Subprogram (Entity (N)) then
5363 Expand_Intrinsic_Call (N, Entity (N));
5366 end Expand_N_Op_And;
5368 ------------------------
5369 -- Expand_N_Op_Concat --
5370 ------------------------
5372 procedure Expand_N_Op_Concat (N : Node_Id) is
5374 -- List of operands to be concatenated
5377 -- Node which is to be replaced by the result of concatenating the nodes
5378 -- in the list Opnds.
5381 -- Ensure validity of both operands
5383 Binary_Op_Validity_Checks (N);
5385 -- If we are the left operand of a concatenation higher up the tree,
5386 -- then do nothing for now, since we want to deal with a series of
5387 -- concatenations as a unit.
5389 if Nkind (Parent (N)) = N_Op_Concat
5390 and then N = Left_Opnd (Parent (N))
5395 -- We get here with a concatenation whose left operand may be a
5396 -- concatenation itself with a consistent type. We need to process
5397 -- these concatenation operands from left to right, which means
5398 -- from the deepest node in the tree to the highest node.
5401 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
5402 Cnode := Left_Opnd (Cnode);
5405 -- Now Cnode is the deepest concatenation, and its parents are the
5406 -- concatenation nodes above, so now we process bottom up, doing the
5407 -- operations. We gather a string that is as long as possible up to five
5410 -- The outer loop runs more than once if more than one concatenation
5411 -- type is involved.
5414 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
5415 Set_Parent (Opnds, N);
5417 -- The inner loop gathers concatenation operands
5419 Inner : while Cnode /= N
5420 and then Base_Type (Etype (Cnode)) =
5421 Base_Type (Etype (Parent (Cnode)))
5423 Cnode := Parent (Cnode);
5424 Append (Right_Opnd (Cnode), Opnds);
5427 Expand_Concatenate (Cnode, Opnds);
5429 exit Outer when Cnode = N;
5430 Cnode := Parent (Cnode);
5432 end Expand_N_Op_Concat;
5434 ------------------------
5435 -- Expand_N_Op_Divide --
5436 ------------------------
5438 procedure Expand_N_Op_Divide (N : Node_Id) is
5439 Loc : constant Source_Ptr := Sloc (N);
5440 Lopnd : constant Node_Id := Left_Opnd (N);
5441 Ropnd : constant Node_Id := Right_Opnd (N);
5442 Ltyp : constant Entity_Id := Etype (Lopnd);
5443 Rtyp : constant Entity_Id := Etype (Ropnd);
5444 Typ : Entity_Id := Etype (N);
5445 Rknow : constant Boolean := Is_Integer_Type (Typ)
5447 Compile_Time_Known_Value (Ropnd);
5451 Binary_Op_Validity_Checks (N);
5454 Rval := Expr_Value (Ropnd);
5457 -- N / 1 = N for integer types
5459 if Rknow and then Rval = Uint_1 then
5464 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
5465 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5466 -- operand is an unsigned integer, as required for this to work.
5468 if Nkind (Ropnd) = N_Op_Expon
5469 and then Is_Power_Of_2_For_Shift (Ropnd)
5471 -- We cannot do this transformation in configurable run time mode if we
5472 -- have 64-bit integers and long shifts are not available.
5476 or else Support_Long_Shifts_On_Target)
5479 Make_Op_Shift_Right (Loc,
5482 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
5483 Analyze_And_Resolve (N, Typ);
5487 -- Do required fixup of universal fixed operation
5489 if Typ = Universal_Fixed then
5490 Fixup_Universal_Fixed_Operation (N);
5494 -- Divisions with fixed-point results
5496 if Is_Fixed_Point_Type (Typ) then
5498 -- No special processing if Treat_Fixed_As_Integer is set, since
5499 -- from a semantic point of view such operations are simply integer
5500 -- operations and will be treated that way.
5502 if not Treat_Fixed_As_Integer (N) then
5503 if Is_Integer_Type (Rtyp) then
5504 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
5506 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
5510 -- Other cases of division of fixed-point operands. Again we exclude the
5511 -- case where Treat_Fixed_As_Integer is set.
5513 elsif (Is_Fixed_Point_Type (Ltyp) or else
5514 Is_Fixed_Point_Type (Rtyp))
5515 and then not Treat_Fixed_As_Integer (N)
5517 if Is_Integer_Type (Typ) then
5518 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
5520 pragma Assert (Is_Floating_Point_Type (Typ));
5521 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
5524 -- Mixed-mode operations can appear in a non-static universal context,
5525 -- in which case the integer argument must be converted explicitly.
5527 elsif Typ = Universal_Real
5528 and then Is_Integer_Type (Rtyp)
5531 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
5533 Analyze_And_Resolve (Ropnd, Universal_Real);
5535 elsif Typ = Universal_Real
5536 and then Is_Integer_Type (Ltyp)
5539 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
5541 Analyze_And_Resolve (Lopnd, Universal_Real);
5543 -- Non-fixed point cases, do integer zero divide and overflow checks
5545 elsif Is_Integer_Type (Typ) then
5546 Apply_Divide_Check (N);
5548 -- Check for 64-bit division available, or long shifts if the divisor
5549 -- is a small power of 2 (since such divides will be converted into
5552 if Esize (Ltyp) > 32
5553 and then not Support_64_Bit_Divides_On_Target
5556 or else not Support_Long_Shifts_On_Target
5557 or else (Rval /= Uint_2 and then
5558 Rval /= Uint_4 and then
5559 Rval /= Uint_8 and then
5560 Rval /= Uint_16 and then
5561 Rval /= Uint_32 and then
5564 Error_Msg_CRT ("64-bit division", N);
5567 -- Deal with Vax_Float
5569 elsif Vax_Float (Typ) then
5570 Expand_Vax_Arith (N);
5573 end Expand_N_Op_Divide;
5575 --------------------
5576 -- Expand_N_Op_Eq --
5577 --------------------
5579 procedure Expand_N_Op_Eq (N : Node_Id) is
5580 Loc : constant Source_Ptr := Sloc (N);
5581 Typ : constant Entity_Id := Etype (N);
5582 Lhs : constant Node_Id := Left_Opnd (N);
5583 Rhs : constant Node_Id := Right_Opnd (N);
5584 Bodies : constant List_Id := New_List;
5585 A_Typ : constant Entity_Id := Etype (Lhs);
5587 Typl : Entity_Id := A_Typ;
5588 Op_Name : Entity_Id;
5591 procedure Build_Equality_Call (Eq : Entity_Id);
5592 -- If a constructed equality exists for the type or for its parent,
5593 -- build and analyze call, adding conversions if the operation is
5596 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
5597 -- Determines whether a type has a subcomponent of an unconstrained
5598 -- Unchecked_Union subtype. Typ is a record type.
5600 -------------------------
5601 -- Build_Equality_Call --
5602 -------------------------
5604 procedure Build_Equality_Call (Eq : Entity_Id) is
5605 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
5606 L_Exp : Node_Id := Relocate_Node (Lhs);
5607 R_Exp : Node_Id := Relocate_Node (Rhs);
5610 if Base_Type (Op_Type) /= Base_Type (A_Typ)
5611 and then not Is_Class_Wide_Type (A_Typ)
5613 L_Exp := OK_Convert_To (Op_Type, L_Exp);
5614 R_Exp := OK_Convert_To (Op_Type, R_Exp);
5617 -- If we have an Unchecked_Union, we need to add the inferred
5618 -- discriminant values as actuals in the function call. At this
5619 -- point, the expansion has determined that both operands have
5620 -- inferable discriminants.
5622 if Is_Unchecked_Union (Op_Type) then
5624 Lhs_Type : constant Node_Id := Etype (L_Exp);
5625 Rhs_Type : constant Node_Id := Etype (R_Exp);
5626 Lhs_Discr_Val : Node_Id;
5627 Rhs_Discr_Val : Node_Id;
5630 -- Per-object constrained selected components require special
5631 -- attention. If the enclosing scope of the component is an
5632 -- Unchecked_Union, we cannot reference its discriminants
5633 -- directly. This is why we use the two extra parameters of
5634 -- the equality function of the enclosing Unchecked_Union.
5636 -- type UU_Type (Discr : Integer := 0) is
5639 -- pragma Unchecked_Union (UU_Type);
5641 -- 1. Unchecked_Union enclosing record:
5643 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
5645 -- Comp : UU_Type (Discr);
5647 -- end Enclosing_UU_Type;
5648 -- pragma Unchecked_Union (Enclosing_UU_Type);
5650 -- Obj1 : Enclosing_UU_Type;
5651 -- Obj2 : Enclosing_UU_Type (1);
5653 -- [. . .] Obj1 = Obj2 [. . .]
5657 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
5659 -- A and B are the formal parameters of the equality function
5660 -- of Enclosing_UU_Type. The function always has two extra
5661 -- formals to capture the inferred discriminant values.
5663 -- 2. Non-Unchecked_Union enclosing record:
5666 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
5669 -- Comp : UU_Type (Discr);
5671 -- end Enclosing_Non_UU_Type;
5673 -- Obj1 : Enclosing_Non_UU_Type;
5674 -- Obj2 : Enclosing_Non_UU_Type (1);
5676 -- ... Obj1 = Obj2 ...
5680 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
5681 -- obj1.discr, obj2.discr)) then
5683 -- In this case we can directly reference the discriminants of
5684 -- the enclosing record.
5688 if Nkind (Lhs) = N_Selected_Component
5689 and then Has_Per_Object_Constraint
5690 (Entity (Selector_Name (Lhs)))
5692 -- Enclosing record is an Unchecked_Union, use formal A
5694 if Is_Unchecked_Union
5695 (Scope (Entity (Selector_Name (Lhs))))
5697 Lhs_Discr_Val := Make_Identifier (Loc, Name_A);
5699 -- Enclosing record is of a non-Unchecked_Union type, it is
5700 -- possible to reference the discriminant.
5704 Make_Selected_Component (Loc,
5705 Prefix => Prefix (Lhs),
5708 (Get_Discriminant_Value
5709 (First_Discriminant (Lhs_Type),
5711 Stored_Constraint (Lhs_Type))));
5714 -- Comment needed here ???
5717 -- Infer the discriminant value
5721 (Get_Discriminant_Value
5722 (First_Discriminant (Lhs_Type),
5724 Stored_Constraint (Lhs_Type)));
5729 if Nkind (Rhs) = N_Selected_Component
5730 and then Has_Per_Object_Constraint
5731 (Entity (Selector_Name (Rhs)))
5733 if Is_Unchecked_Union
5734 (Scope (Entity (Selector_Name (Rhs))))
5736 Rhs_Discr_Val := Make_Identifier (Loc, Name_B);
5740 Make_Selected_Component (Loc,
5741 Prefix => Prefix (Rhs),
5743 New_Copy (Get_Discriminant_Value (
5744 First_Discriminant (Rhs_Type),
5746 Stored_Constraint (Rhs_Type))));
5751 New_Copy (Get_Discriminant_Value (
5752 First_Discriminant (Rhs_Type),
5754 Stored_Constraint (Rhs_Type)));
5759 Make_Function_Call (Loc,
5760 Name => New_Reference_To (Eq, Loc),
5761 Parameter_Associations => New_List (
5768 -- Normal case, not an unchecked union
5772 Make_Function_Call (Loc,
5773 Name => New_Reference_To (Eq, Loc),
5774 Parameter_Associations => New_List (L_Exp, R_Exp)));
5777 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5778 end Build_Equality_Call;
5780 ------------------------------------
5781 -- Has_Unconstrained_UU_Component --
5782 ------------------------------------
5784 function Has_Unconstrained_UU_Component
5785 (Typ : Node_Id) return Boolean
5787 Tdef : constant Node_Id :=
5788 Type_Definition (Declaration_Node (Base_Type (Typ)));
5792 function Component_Is_Unconstrained_UU
5793 (Comp : Node_Id) return Boolean;
5794 -- Determines whether the subtype of the component is an
5795 -- unconstrained Unchecked_Union.
5797 function Variant_Is_Unconstrained_UU
5798 (Variant : Node_Id) return Boolean;
5799 -- Determines whether a component of the variant has an unconstrained
5800 -- Unchecked_Union subtype.
5802 -----------------------------------
5803 -- Component_Is_Unconstrained_UU --
5804 -----------------------------------
5806 function Component_Is_Unconstrained_UU
5807 (Comp : Node_Id) return Boolean
5810 if Nkind (Comp) /= N_Component_Declaration then
5815 Sindic : constant Node_Id :=
5816 Subtype_Indication (Component_Definition (Comp));
5819 -- Unconstrained nominal type. In the case of a constraint
5820 -- present, the node kind would have been N_Subtype_Indication.
5822 if Nkind (Sindic) = N_Identifier then
5823 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
5828 end Component_Is_Unconstrained_UU;
5830 ---------------------------------
5831 -- Variant_Is_Unconstrained_UU --
5832 ---------------------------------
5834 function Variant_Is_Unconstrained_UU
5835 (Variant : Node_Id) return Boolean
5837 Clist : constant Node_Id := Component_List (Variant);
5840 if Is_Empty_List (Component_Items (Clist)) then
5844 -- We only need to test one component
5847 Comp : Node_Id := First (Component_Items (Clist));
5850 while Present (Comp) loop
5851 if Component_Is_Unconstrained_UU (Comp) then
5859 -- None of the components withing the variant were of
5860 -- unconstrained Unchecked_Union type.
5863 end Variant_Is_Unconstrained_UU;
5865 -- Start of processing for Has_Unconstrained_UU_Component
5868 if Null_Present (Tdef) then
5872 Clist := Component_List (Tdef);
5873 Vpart := Variant_Part (Clist);
5875 -- Inspect available components
5877 if Present (Component_Items (Clist)) then
5879 Comp : Node_Id := First (Component_Items (Clist));
5882 while Present (Comp) loop
5884 -- One component is sufficient
5886 if Component_Is_Unconstrained_UU (Comp) then
5895 -- Inspect available components withing variants
5897 if Present (Vpart) then
5899 Variant : Node_Id := First (Variants (Vpart));
5902 while Present (Variant) loop
5904 -- One component within a variant is sufficient
5906 if Variant_Is_Unconstrained_UU (Variant) then
5915 -- Neither the available components, nor the components inside the
5916 -- variant parts were of an unconstrained Unchecked_Union subtype.
5919 end Has_Unconstrained_UU_Component;
5921 -- Start of processing for Expand_N_Op_Eq
5924 Binary_Op_Validity_Checks (N);
5926 if Ekind (Typl) = E_Private_Type then
5927 Typl := Underlying_Type (Typl);
5928 elsif Ekind (Typl) = E_Private_Subtype then
5929 Typl := Underlying_Type (Base_Type (Typl));
5934 -- It may happen in error situations that the underlying type is not
5935 -- set. The error will be detected later, here we just defend the
5942 Typl := Base_Type (Typl);
5944 -- Boolean types (requiring handling of non-standard case)
5946 if Is_Boolean_Type (Typl) then
5947 Adjust_Condition (Left_Opnd (N));
5948 Adjust_Condition (Right_Opnd (N));
5949 Set_Etype (N, Standard_Boolean);
5950 Adjust_Result_Type (N, Typ);
5954 elsif Is_Array_Type (Typl) then
5956 -- If we are doing full validity checking, and it is possible for the
5957 -- array elements to be invalid then expand out array comparisons to
5958 -- make sure that we check the array elements.
5960 if Validity_Check_Operands
5961 and then not Is_Known_Valid (Component_Type (Typl))
5964 Save_Force_Validity_Checks : constant Boolean :=
5965 Force_Validity_Checks;
5967 Force_Validity_Checks := True;
5969 Expand_Array_Equality
5971 Relocate_Node (Lhs),
5972 Relocate_Node (Rhs),
5975 Insert_Actions (N, Bodies);
5976 Analyze_And_Resolve (N, Standard_Boolean);
5977 Force_Validity_Checks := Save_Force_Validity_Checks;
5980 -- Packed case where both operands are known aligned
5982 elsif Is_Bit_Packed_Array (Typl)
5983 and then not Is_Possibly_Unaligned_Object (Lhs)
5984 and then not Is_Possibly_Unaligned_Object (Rhs)
5986 Expand_Packed_Eq (N);
5988 -- Where the component type is elementary we can use a block bit
5989 -- comparison (if supported on the target) exception in the case
5990 -- of floating-point (negative zero issues require element by
5991 -- element comparison), and atomic types (where we must be sure
5992 -- to load elements independently) and possibly unaligned arrays.
5994 elsif Is_Elementary_Type (Component_Type (Typl))
5995 and then not Is_Floating_Point_Type (Component_Type (Typl))
5996 and then not Is_Atomic (Component_Type (Typl))
5997 and then not Is_Possibly_Unaligned_Object (Lhs)
5998 and then not Is_Possibly_Unaligned_Object (Rhs)
5999 and then Support_Composite_Compare_On_Target
6003 -- For composite and floating-point cases, expand equality loop to
6004 -- make sure of using proper comparisons for tagged types, and
6005 -- correctly handling the floating-point case.
6009 Expand_Array_Equality
6011 Relocate_Node (Lhs),
6012 Relocate_Node (Rhs),
6015 Insert_Actions (N, Bodies, Suppress => All_Checks);
6016 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6021 elsif Is_Record_Type (Typl) then
6023 -- For tagged types, use the primitive "="
6025 if Is_Tagged_Type (Typl) then
6027 -- No need to do anything else compiling under restriction
6028 -- No_Dispatching_Calls. During the semantic analysis we
6029 -- already notified such violation.
6031 if Restriction_Active (No_Dispatching_Calls) then
6035 -- If this is derived from an untagged private type completed with
6036 -- a tagged type, it does not have a full view, so we use the
6037 -- primitive operations of the private type. This check should no
6038 -- longer be necessary when these types get their full views???
6040 if Is_Private_Type (A_Typ)
6041 and then not Is_Tagged_Type (A_Typ)
6042 and then Is_Derived_Type (A_Typ)
6043 and then No (Full_View (A_Typ))
6045 -- Search for equality operation, checking that the operands
6046 -- have the same type. Note that we must find a matching entry,
6047 -- or something is very wrong!
6049 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
6051 while Present (Prim) loop
6052 exit when Chars (Node (Prim)) = Name_Op_Eq
6053 and then Etype (First_Formal (Node (Prim))) =
6054 Etype (Next_Formal (First_Formal (Node (Prim))))
6056 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6061 pragma Assert (Present (Prim));
6062 Op_Name := Node (Prim);
6064 -- Find the type's predefined equality or an overriding
6065 -- user- defined equality. The reason for not simply calling
6066 -- Find_Prim_Op here is that there may be a user-defined
6067 -- overloaded equality op that precedes the equality that we want,
6068 -- so we have to explicitly search (e.g., there could be an
6069 -- equality with two different parameter types).
6072 if Is_Class_Wide_Type (Typl) then
6073 Typl := Root_Type (Typl);
6076 Prim := First_Elmt (Primitive_Operations (Typl));
6077 while Present (Prim) loop
6078 exit when Chars (Node (Prim)) = Name_Op_Eq
6079 and then Etype (First_Formal (Node (Prim))) =
6080 Etype (Next_Formal (First_Formal (Node (Prim))))
6082 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6087 pragma Assert (Present (Prim));
6088 Op_Name := Node (Prim);
6091 Build_Equality_Call (Op_Name);
6093 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
6094 -- predefined equality operator for a type which has a subcomponent
6095 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
6097 elsif Has_Unconstrained_UU_Component (Typl) then
6099 Make_Raise_Program_Error (Loc,
6100 Reason => PE_Unchecked_Union_Restriction));
6102 -- Prevent Gigi from generating incorrect code by rewriting the
6103 -- equality as a standard False.
6106 New_Occurrence_Of (Standard_False, Loc));
6108 elsif Is_Unchecked_Union (Typl) then
6110 -- If we can infer the discriminants of the operands, we make a
6111 -- call to the TSS equality function.
6113 if Has_Inferable_Discriminants (Lhs)
6115 Has_Inferable_Discriminants (Rhs)
6118 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6121 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
6122 -- the predefined equality operator for an Unchecked_Union type
6123 -- if either of the operands lack inferable discriminants.
6126 Make_Raise_Program_Error (Loc,
6127 Reason => PE_Unchecked_Union_Restriction));
6129 -- Prevent Gigi from generating incorrect code by rewriting
6130 -- the equality as a standard False.
6133 New_Occurrence_Of (Standard_False, Loc));
6137 -- If a type support function is present (for complex cases), use it
6139 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
6141 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6143 -- Otherwise expand the component by component equality. Note that
6144 -- we never use block-bit comparisons for records, because of the
6145 -- problems with gaps. The backend will often be able to recombine
6146 -- the separate comparisons that we generate here.
6149 Remove_Side_Effects (Lhs);
6150 Remove_Side_Effects (Rhs);
6152 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
6154 Insert_Actions (N, Bodies, Suppress => All_Checks);
6155 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6159 -- Test if result is known at compile time
6161 Rewrite_Comparison (N);
6163 -- If we still have comparison for Vax_Float, process it
6165 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
6166 Expand_Vax_Comparison (N);
6170 Optimize_Length_Comparison (N);
6173 -----------------------
6174 -- Expand_N_Op_Expon --
6175 -----------------------
6177 procedure Expand_N_Op_Expon (N : Node_Id) is
6178 Loc : constant Source_Ptr := Sloc (N);
6179 Typ : constant Entity_Id := Etype (N);
6180 Rtyp : constant Entity_Id := Root_Type (Typ);
6181 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
6182 Bastyp : constant Node_Id := Etype (Base);
6183 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
6184 Exptyp : constant Entity_Id := Etype (Exp);
6185 Ovflo : constant Boolean := Do_Overflow_Check (N);
6194 Binary_Op_Validity_Checks (N);
6196 -- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node
6198 if CodePeer_Mode or ALFA_Mode then
6202 -- If either operand is of a private type, then we have the use of an
6203 -- intrinsic operator, and we get rid of the privateness, by using root
6204 -- types of underlying types for the actual operation. Otherwise the
6205 -- private types will cause trouble if we expand multiplications or
6206 -- shifts etc. We also do this transformation if the result type is
6207 -- different from the base type.
6209 if Is_Private_Type (Etype (Base))
6210 or else Is_Private_Type (Typ)
6211 or else Is_Private_Type (Exptyp)
6212 or else Rtyp /= Root_Type (Bastyp)
6215 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
6216 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
6220 Unchecked_Convert_To (Typ,
6222 Left_Opnd => Unchecked_Convert_To (Bt, Base),
6223 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
6224 Analyze_And_Resolve (N, Typ);
6229 -- Test for case of known right argument
6231 if Compile_Time_Known_Value (Exp) then
6232 Expv := Expr_Value (Exp);
6234 -- We only fold small non-negative exponents. You might think we
6235 -- could fold small negative exponents for the real case, but we
6236 -- can't because we are required to raise Constraint_Error for
6237 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
6238 -- See ACVC test C4A012B.
6240 if Expv >= 0 and then Expv <= 4 then
6242 -- X ** 0 = 1 (or 1.0)
6246 -- Call Remove_Side_Effects to ensure that any side effects
6247 -- in the ignored left operand (in particular function calls
6248 -- to user defined functions) are properly executed.
6250 Remove_Side_Effects (Base);
6252 if Ekind (Typ) in Integer_Kind then
6253 Xnode := Make_Integer_Literal (Loc, Intval => 1);
6255 Xnode := Make_Real_Literal (Loc, Ureal_1);
6267 Make_Op_Multiply (Loc,
6268 Left_Opnd => Duplicate_Subexpr (Base),
6269 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6271 -- X ** 3 = X * X * X
6275 Make_Op_Multiply (Loc,
6277 Make_Op_Multiply (Loc,
6278 Left_Opnd => Duplicate_Subexpr (Base),
6279 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
6280 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6283 -- En : constant base'type := base * base;
6288 Temp := Make_Temporary (Loc, 'E', Base);
6290 Insert_Actions (N, New_List (
6291 Make_Object_Declaration (Loc,
6292 Defining_Identifier => Temp,
6293 Constant_Present => True,
6294 Object_Definition => New_Reference_To (Typ, Loc),
6296 Make_Op_Multiply (Loc,
6297 Left_Opnd => Duplicate_Subexpr (Base),
6298 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
6301 Make_Op_Multiply (Loc,
6302 Left_Opnd => New_Reference_To (Temp, Loc),
6303 Right_Opnd => New_Reference_To (Temp, Loc));
6307 Analyze_And_Resolve (N, Typ);
6312 -- Case of (2 ** expression) appearing as an argument of an integer
6313 -- multiplication, or as the right argument of a division of a non-
6314 -- negative integer. In such cases we leave the node untouched, setting
6315 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
6316 -- of the higher level node converts it into a shift.
6318 -- Another case is 2 ** N in any other context. We simply convert
6319 -- this to 1 * 2 ** N, and then the above transformation applies.
6321 -- Note: this transformation is not applicable for a modular type with
6322 -- a non-binary modulus in the multiplication case, since we get a wrong
6323 -- result if the shift causes an overflow before the modular reduction.
6325 if Nkind (Base) = N_Integer_Literal
6326 and then Intval (Base) = 2
6327 and then Is_Integer_Type (Root_Type (Exptyp))
6328 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
6329 and then Is_Unsigned_Type (Exptyp)
6332 -- First the multiply and divide cases
6334 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
6336 P : constant Node_Id := Parent (N);
6337 L : constant Node_Id := Left_Opnd (P);
6338 R : constant Node_Id := Right_Opnd (P);
6341 if (Nkind (P) = N_Op_Multiply
6342 and then not Non_Binary_Modulus (Typ)
6344 ((Is_Integer_Type (Etype (L)) and then R = N)
6346 (Is_Integer_Type (Etype (R)) and then L = N))
6347 and then not Do_Overflow_Check (P))
6349 (Nkind (P) = N_Op_Divide
6350 and then Is_Integer_Type (Etype (L))
6351 and then Is_Unsigned_Type (Etype (L))
6353 and then not Do_Overflow_Check (P))
6355 Set_Is_Power_Of_2_For_Shift (N);
6360 -- Now the other cases
6362 elsif not Non_Binary_Modulus (Typ) then
6364 Make_Op_Multiply (Loc,
6365 Left_Opnd => Make_Integer_Literal (Loc, 1),
6366 Right_Opnd => Relocate_Node (N)));
6367 Analyze_And_Resolve (N, Typ);
6372 -- Fall through if exponentiation must be done using a runtime routine
6374 -- First deal with modular case
6376 if Is_Modular_Integer_Type (Rtyp) then
6378 -- Non-binary case, we call the special exponentiation routine for
6379 -- the non-binary case, converting the argument to Long_Long_Integer
6380 -- and passing the modulus value. Then the result is converted back
6381 -- to the base type.
6383 if Non_Binary_Modulus (Rtyp) then
6386 Make_Function_Call (Loc,
6387 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
6388 Parameter_Associations => New_List (
6389 Convert_To (Standard_Integer, Base),
6390 Make_Integer_Literal (Loc, Modulus (Rtyp)),
6393 -- Binary case, in this case, we call one of two routines, either the
6394 -- unsigned integer case, or the unsigned long long integer case,
6395 -- with a final "and" operation to do the required mod.
6398 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
6399 Ent := RTE (RE_Exp_Unsigned);
6401 Ent := RTE (RE_Exp_Long_Long_Unsigned);
6408 Make_Function_Call (Loc,
6409 Name => New_Reference_To (Ent, Loc),
6410 Parameter_Associations => New_List (
6411 Convert_To (Etype (First_Formal (Ent)), Base),
6414 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
6418 -- Common exit point for modular type case
6420 Analyze_And_Resolve (N, Typ);
6423 -- Signed integer cases, done using either Integer or Long_Long_Integer.
6424 -- It is not worth having routines for Short_[Short_]Integer, since for
6425 -- most machines it would not help, and it would generate more code that
6426 -- might need certification when a certified run time is required.
6428 -- In the integer cases, we have two routines, one for when overflow
6429 -- checks are required, and one when they are not required, since there
6430 -- is a real gain in omitting checks on many machines.
6432 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
6433 or else (Rtyp = Base_Type (Standard_Long_Integer)
6435 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
6436 or else (Rtyp = Universal_Integer)
6438 Etyp := Standard_Long_Long_Integer;
6441 Rent := RE_Exp_Long_Long_Integer;
6443 Rent := RE_Exn_Long_Long_Integer;
6446 elsif Is_Signed_Integer_Type (Rtyp) then
6447 Etyp := Standard_Integer;
6450 Rent := RE_Exp_Integer;
6452 Rent := RE_Exn_Integer;
6455 -- Floating-point cases, always done using Long_Long_Float. We do not
6456 -- need separate routines for the overflow case here, since in the case
6457 -- of floating-point, we generate infinities anyway as a rule (either
6458 -- that or we automatically trap overflow), and if there is an infinity
6459 -- generated and a range check is required, the check will fail anyway.
6462 pragma Assert (Is_Floating_Point_Type (Rtyp));
6463 Etyp := Standard_Long_Long_Float;
6464 Rent := RE_Exn_Long_Long_Float;
6467 -- Common processing for integer cases and floating-point cases.
6468 -- If we are in the right type, we can call runtime routine directly
6471 and then Rtyp /= Universal_Integer
6472 and then Rtyp /= Universal_Real
6475 Make_Function_Call (Loc,
6476 Name => New_Reference_To (RTE (Rent), Loc),
6477 Parameter_Associations => New_List (Base, Exp)));
6479 -- Otherwise we have to introduce conversions (conversions are also
6480 -- required in the universal cases, since the runtime routine is
6481 -- typed using one of the standard types).
6486 Make_Function_Call (Loc,
6487 Name => New_Reference_To (RTE (Rent), Loc),
6488 Parameter_Associations => New_List (
6489 Convert_To (Etyp, Base),
6493 Analyze_And_Resolve (N, Typ);
6497 when RE_Not_Available =>
6499 end Expand_N_Op_Expon;
6501 --------------------
6502 -- Expand_N_Op_Ge --
6503 --------------------
6505 procedure Expand_N_Op_Ge (N : Node_Id) is
6506 Typ : constant Entity_Id := Etype (N);
6507 Op1 : constant Node_Id := Left_Opnd (N);
6508 Op2 : constant Node_Id := Right_Opnd (N);
6509 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6512 Binary_Op_Validity_Checks (N);
6514 if Is_Array_Type (Typ1) then
6515 Expand_Array_Comparison (N);
6519 if Is_Boolean_Type (Typ1) then
6520 Adjust_Condition (Op1);
6521 Adjust_Condition (Op2);
6522 Set_Etype (N, Standard_Boolean);
6523 Adjust_Result_Type (N, Typ);
6526 Rewrite_Comparison (N);
6528 -- If we still have comparison, and Vax_Float type, process it
6530 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6531 Expand_Vax_Comparison (N);
6535 Optimize_Length_Comparison (N);
6538 --------------------
6539 -- Expand_N_Op_Gt --
6540 --------------------
6542 procedure Expand_N_Op_Gt (N : Node_Id) is
6543 Typ : constant Entity_Id := Etype (N);
6544 Op1 : constant Node_Id := Left_Opnd (N);
6545 Op2 : constant Node_Id := Right_Opnd (N);
6546 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6549 Binary_Op_Validity_Checks (N);
6551 if Is_Array_Type (Typ1) then
6552 Expand_Array_Comparison (N);
6556 if Is_Boolean_Type (Typ1) then
6557 Adjust_Condition (Op1);
6558 Adjust_Condition (Op2);
6559 Set_Etype (N, Standard_Boolean);
6560 Adjust_Result_Type (N, Typ);
6563 Rewrite_Comparison (N);
6565 -- If we still have comparison, and Vax_Float type, process it
6567 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6568 Expand_Vax_Comparison (N);
6572 Optimize_Length_Comparison (N);
6575 --------------------
6576 -- Expand_N_Op_Le --
6577 --------------------
6579 procedure Expand_N_Op_Le (N : Node_Id) is
6580 Typ : constant Entity_Id := Etype (N);
6581 Op1 : constant Node_Id := Left_Opnd (N);
6582 Op2 : constant Node_Id := Right_Opnd (N);
6583 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6586 Binary_Op_Validity_Checks (N);
6588 if Is_Array_Type (Typ1) then
6589 Expand_Array_Comparison (N);
6593 if Is_Boolean_Type (Typ1) then
6594 Adjust_Condition (Op1);
6595 Adjust_Condition (Op2);
6596 Set_Etype (N, Standard_Boolean);
6597 Adjust_Result_Type (N, Typ);
6600 Rewrite_Comparison (N);
6602 -- If we still have comparison, and Vax_Float type, process it
6604 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6605 Expand_Vax_Comparison (N);
6609 Optimize_Length_Comparison (N);
6612 --------------------
6613 -- Expand_N_Op_Lt --
6614 --------------------
6616 procedure Expand_N_Op_Lt (N : Node_Id) is
6617 Typ : constant Entity_Id := Etype (N);
6618 Op1 : constant Node_Id := Left_Opnd (N);
6619 Op2 : constant Node_Id := Right_Opnd (N);
6620 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6623 Binary_Op_Validity_Checks (N);
6625 if Is_Array_Type (Typ1) then
6626 Expand_Array_Comparison (N);
6630 if Is_Boolean_Type (Typ1) then
6631 Adjust_Condition (Op1);
6632 Adjust_Condition (Op2);
6633 Set_Etype (N, Standard_Boolean);
6634 Adjust_Result_Type (N, Typ);
6637 Rewrite_Comparison (N);
6639 -- If we still have comparison, and Vax_Float type, process it
6641 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6642 Expand_Vax_Comparison (N);
6646 Optimize_Length_Comparison (N);
6649 -----------------------
6650 -- Expand_N_Op_Minus --
6651 -----------------------
6653 procedure Expand_N_Op_Minus (N : Node_Id) is
6654 Loc : constant Source_Ptr := Sloc (N);
6655 Typ : constant Entity_Id := Etype (N);
6658 Unary_Op_Validity_Checks (N);
6660 if not Backend_Overflow_Checks_On_Target
6661 and then Is_Signed_Integer_Type (Etype (N))
6662 and then Do_Overflow_Check (N)
6664 -- Software overflow checking expands -expr into (0 - expr)
6667 Make_Op_Subtract (Loc,
6668 Left_Opnd => Make_Integer_Literal (Loc, 0),
6669 Right_Opnd => Right_Opnd (N)));
6671 Analyze_And_Resolve (N, Typ);
6673 -- Vax floating-point types case
6675 elsif Vax_Float (Etype (N)) then
6676 Expand_Vax_Arith (N);
6678 end Expand_N_Op_Minus;
6680 ---------------------
6681 -- Expand_N_Op_Mod --
6682 ---------------------
6684 procedure Expand_N_Op_Mod (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);
6689 DOC : constant Boolean := Do_Overflow_Check (N);
6690 DDC : constant Boolean := Do_Division_Check (N);
6700 pragma Warnings (Off, Lhi);
6703 Binary_Op_Validity_Checks (N);
6705 Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
6706 Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
6708 -- Convert mod to rem if operands are known non-negative. We do this
6709 -- since it is quite likely that this will improve the quality of code,
6710 -- (the operation now corresponds to the hardware remainder), and it
6711 -- does not seem likely that it could be harmful.
6713 if LOK and then Llo >= 0
6715 ROK and then Rlo >= 0
6718 Make_Op_Rem (Sloc (N),
6719 Left_Opnd => Left_Opnd (N),
6720 Right_Opnd => Right_Opnd (N)));
6722 -- Instead of reanalyzing the node we do the analysis manually. This
6723 -- avoids anomalies when the replacement is done in an instance and
6724 -- is epsilon more efficient.
6726 Set_Entity (N, Standard_Entity (S_Op_Rem));
6728 Set_Do_Overflow_Check (N, DOC);
6729 Set_Do_Division_Check (N, DDC);
6730 Expand_N_Op_Rem (N);
6733 -- Otherwise, normal mod processing
6736 if Is_Integer_Type (Etype (N)) then
6737 Apply_Divide_Check (N);
6740 -- Apply optimization x mod 1 = 0. We don't really need that with
6741 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
6742 -- certainly harmless.
6744 if Is_Integer_Type (Etype (N))
6745 and then Compile_Time_Known_Value (Right)
6746 and then Expr_Value (Right) = Uint_1
6748 -- Call Remove_Side_Effects to ensure that any side effects in
6749 -- the ignored left operand (in particular function calls to
6750 -- user defined functions) are properly executed.
6752 Remove_Side_Effects (Left);
6754 Rewrite (N, Make_Integer_Literal (Loc, 0));
6755 Analyze_And_Resolve (N, Typ);
6759 -- Deal with annoying case of largest negative number remainder
6760 -- minus one. Gigi does not handle this case correctly, because
6761 -- it generates a divide instruction which may trap in this case.
6763 -- In fact the check is quite easy, if the right operand is -1, then
6764 -- the mod value is always 0, and we can just ignore the left operand
6765 -- completely in this case.
6767 -- The operand type may be private (e.g. in the expansion of an
6768 -- intrinsic operation) so we must use the underlying type to get the
6769 -- bounds, and convert the literals explicitly.
6773 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
6775 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
6777 ((not LOK) or else (Llo = LLB))
6780 Make_Conditional_Expression (Loc,
6781 Expressions => New_List (
6783 Left_Opnd => Duplicate_Subexpr (Right),
6785 Unchecked_Convert_To (Typ,
6786 Make_Integer_Literal (Loc, -1))),
6787 Unchecked_Convert_To (Typ,
6788 Make_Integer_Literal (Loc, Uint_0)),
6789 Relocate_Node (N))));
6791 Set_Analyzed (Next (Next (First (Expressions (N)))));
6792 Analyze_And_Resolve (N, Typ);
6795 end Expand_N_Op_Mod;
6797 --------------------------
6798 -- Expand_N_Op_Multiply --
6799 --------------------------
6801 procedure Expand_N_Op_Multiply (N : Node_Id) is
6802 Loc : constant Source_Ptr := Sloc (N);
6803 Lop : constant Node_Id := Left_Opnd (N);
6804 Rop : constant Node_Id := Right_Opnd (N);
6806 Lp2 : constant Boolean :=
6807 Nkind (Lop) = N_Op_Expon
6808 and then Is_Power_Of_2_For_Shift (Lop);
6810 Rp2 : constant Boolean :=
6811 Nkind (Rop) = N_Op_Expon
6812 and then Is_Power_Of_2_For_Shift (Rop);
6814 Ltyp : constant Entity_Id := Etype (Lop);
6815 Rtyp : constant Entity_Id := Etype (Rop);
6816 Typ : Entity_Id := Etype (N);
6819 Binary_Op_Validity_Checks (N);
6821 -- Special optimizations for integer types
6823 if Is_Integer_Type (Typ) then
6825 -- N * 0 = 0 for integer types
6827 if Compile_Time_Known_Value (Rop)
6828 and then Expr_Value (Rop) = Uint_0
6830 -- Call Remove_Side_Effects to ensure that any side effects in
6831 -- the ignored left operand (in particular function calls to
6832 -- user defined functions) are properly executed.
6834 Remove_Side_Effects (Lop);
6836 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6837 Analyze_And_Resolve (N, Typ);
6841 -- Similar handling for 0 * N = 0
6843 if Compile_Time_Known_Value (Lop)
6844 and then Expr_Value (Lop) = Uint_0
6846 Remove_Side_Effects (Rop);
6847 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
6848 Analyze_And_Resolve (N, Typ);
6852 -- N * 1 = 1 * N = N for integer types
6854 -- This optimisation is not done if we are going to
6855 -- rewrite the product 1 * 2 ** N to a shift.
6857 if Compile_Time_Known_Value (Rop)
6858 and then Expr_Value (Rop) = Uint_1
6864 elsif Compile_Time_Known_Value (Lop)
6865 and then Expr_Value (Lop) = Uint_1
6873 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
6874 -- Is_Power_Of_2_For_Shift is set means that we know that our left
6875 -- operand is an integer, as required for this to work.
6880 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
6884 Left_Opnd => Make_Integer_Literal (Loc, 2),
6887 Left_Opnd => Right_Opnd (Lop),
6888 Right_Opnd => Right_Opnd (Rop))));
6889 Analyze_And_Resolve (N, Typ);
6894 Make_Op_Shift_Left (Loc,
6897 Convert_To (Standard_Natural, Right_Opnd (Rop))));
6898 Analyze_And_Resolve (N, Typ);
6902 -- Same processing for the operands the other way round
6906 Make_Op_Shift_Left (Loc,
6909 Convert_To (Standard_Natural, Right_Opnd (Lop))));
6910 Analyze_And_Resolve (N, Typ);
6914 -- Do required fixup of universal fixed operation
6916 if Typ = Universal_Fixed then
6917 Fixup_Universal_Fixed_Operation (N);
6921 -- Multiplications with fixed-point results
6923 if Is_Fixed_Point_Type (Typ) then
6925 -- No special processing if Treat_Fixed_As_Integer is set, since from
6926 -- a semantic point of view such operations are simply integer
6927 -- operations and will be treated that way.
6929 if not Treat_Fixed_As_Integer (N) then
6931 -- Case of fixed * integer => fixed
6933 if Is_Integer_Type (Rtyp) then
6934 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
6936 -- Case of integer * fixed => fixed
6938 elsif Is_Integer_Type (Ltyp) then
6939 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
6941 -- Case of fixed * fixed => fixed
6944 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
6948 -- Other cases of multiplication of fixed-point operands. Again we
6949 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
6951 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
6952 and then not Treat_Fixed_As_Integer (N)
6954 if Is_Integer_Type (Typ) then
6955 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
6957 pragma Assert (Is_Floating_Point_Type (Typ));
6958 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
6961 -- Mixed-mode operations can appear in a non-static universal context,
6962 -- in which case the integer argument must be converted explicitly.
6964 elsif Typ = Universal_Real
6965 and then Is_Integer_Type (Rtyp)
6967 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
6969 Analyze_And_Resolve (Rop, Universal_Real);
6971 elsif Typ = Universal_Real
6972 and then Is_Integer_Type (Ltyp)
6974 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
6976 Analyze_And_Resolve (Lop, Universal_Real);
6978 -- Non-fixed point cases, check software overflow checking required
6980 elsif Is_Signed_Integer_Type (Etype (N)) then
6981 Apply_Arithmetic_Overflow_Check (N);
6983 -- Deal with VAX float case
6985 elsif Vax_Float (Typ) then
6986 Expand_Vax_Arith (N);
6989 end Expand_N_Op_Multiply;
6991 --------------------
6992 -- Expand_N_Op_Ne --
6993 --------------------
6995 procedure Expand_N_Op_Ne (N : Node_Id) is
6996 Typ : constant Entity_Id := Etype (Left_Opnd (N));
6999 -- Case of elementary type with standard operator
7001 if Is_Elementary_Type (Typ)
7002 and then Sloc (Entity (N)) = Standard_Location
7004 Binary_Op_Validity_Checks (N);
7006 -- Boolean types (requiring handling of non-standard case)
7008 if Is_Boolean_Type (Typ) then
7009 Adjust_Condition (Left_Opnd (N));
7010 Adjust_Condition (Right_Opnd (N));
7011 Set_Etype (N, Standard_Boolean);
7012 Adjust_Result_Type (N, Typ);
7015 Rewrite_Comparison (N);
7017 -- If we still have comparison for Vax_Float, process it
7019 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
7020 Expand_Vax_Comparison (N);
7024 -- For all cases other than elementary types, we rewrite node as the
7025 -- negation of an equality operation, and reanalyze. The equality to be
7026 -- used is defined in the same scope and has the same signature. This
7027 -- signature must be set explicitly since in an instance it may not have
7028 -- the same visibility as in the generic unit. This avoids duplicating
7029 -- or factoring the complex code for record/array equality tests etc.
7033 Loc : constant Source_Ptr := Sloc (N);
7035 Ne : constant Entity_Id := Entity (N);
7038 Binary_Op_Validity_Checks (N);
7044 Left_Opnd => Left_Opnd (N),
7045 Right_Opnd => Right_Opnd (N)));
7046 Set_Paren_Count (Right_Opnd (Neg), 1);
7048 if Scope (Ne) /= Standard_Standard then
7049 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
7052 -- For navigation purposes, we want to treat the inequality as an
7053 -- implicit reference to the corresponding equality. Preserve the
7054 -- Comes_From_ source flag to generate proper Xref entries.
7056 Preserve_Comes_From_Source (Neg, N);
7057 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
7059 Analyze_And_Resolve (N, Standard_Boolean);
7063 Optimize_Length_Comparison (N);
7066 ---------------------
7067 -- Expand_N_Op_Not --
7068 ---------------------
7070 -- If the argument is other than a Boolean array type, there is no special
7071 -- expansion required, except for VMS operations on signed integers.
7073 -- For the packed case, we call the special routine in Exp_Pakd, except
7074 -- that if the component size is greater than one, we use the standard
7075 -- routine generating a gruesome loop (it is so peculiar to have packed
7076 -- arrays with non-standard Boolean representations anyway, so it does not
7077 -- matter that we do not handle this case efficiently).
7079 -- For the unpacked case (and for the special packed case where we have non
7080 -- standard Booleans, as discussed above), we generate and insert into the
7081 -- tree the following function definition:
7083 -- function Nnnn (A : arr) is
7086 -- for J in a'range loop
7087 -- B (J) := not A (J);
7092 -- Here arr is the actual subtype of the parameter (and hence always
7093 -- constrained). Then we replace the not with a call to this function.
7095 procedure Expand_N_Op_Not (N : Node_Id) is
7096 Loc : constant Source_Ptr := Sloc (N);
7097 Typ : constant Entity_Id := Etype (N);
7106 Func_Name : Entity_Id;
7107 Loop_Statement : Node_Id;
7110 Unary_Op_Validity_Checks (N);
7112 -- For boolean operand, deal with non-standard booleans
7114 if Is_Boolean_Type (Typ) then
7115 Adjust_Condition (Right_Opnd (N));
7116 Set_Etype (N, Standard_Boolean);
7117 Adjust_Result_Type (N, Typ);
7121 -- For the VMS "not" on signed integer types, use conversion to and from
7122 -- a predefined modular type.
7124 if Is_VMS_Operator (Entity (N)) then
7130 -- If this is a derived type, retrieve original VMS type so that
7131 -- the proper sized type is used for intermediate values.
7133 if Is_Derived_Type (Typ) then
7134 Rtyp := First_Subtype (Etype (Typ));
7139 -- The proper unsigned type must have a size compatible with the
7140 -- operand, to prevent misalignment.
7142 if RM_Size (Rtyp) <= 8 then
7143 Utyp := RTE (RE_Unsigned_8);
7145 elsif RM_Size (Rtyp) <= 16 then
7146 Utyp := RTE (RE_Unsigned_16);
7148 elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
7149 Utyp := RTE (RE_Unsigned_32);
7152 Utyp := RTE (RE_Long_Long_Unsigned);
7156 Unchecked_Convert_To (Typ,
7158 Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
7159 Analyze_And_Resolve (N, Typ);
7164 -- Only array types need any other processing. In formal verification
7165 -- mode, no other processing is done.
7167 if not Is_Array_Type (Typ) or else ALFA_Mode then
7171 -- Case of array operand. If bit packed with a component size of 1,
7172 -- handle it in Exp_Pakd if the operand is known to be aligned.
7174 if Is_Bit_Packed_Array (Typ)
7175 and then Component_Size (Typ) = 1
7176 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
7178 Expand_Packed_Not (N);
7182 -- Case of array operand which is not bit-packed. If the context is
7183 -- a safe assignment, call in-place operation, If context is a larger
7184 -- boolean expression in the context of a safe assignment, expansion is
7185 -- done by enclosing operation.
7187 Opnd := Relocate_Node (Right_Opnd (N));
7188 Convert_To_Actual_Subtype (Opnd);
7189 Arr := Etype (Opnd);
7190 Ensure_Defined (Arr, N);
7191 Silly_Boolean_Array_Not_Test (N, Arr);
7193 if Nkind (Parent (N)) = N_Assignment_Statement then
7194 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
7195 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7198 -- Special case the negation of a binary operation
7200 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
7201 and then Safe_In_Place_Array_Op
7202 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
7204 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7208 elsif Nkind (Parent (N)) in N_Binary_Op
7209 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
7212 Op1 : constant Node_Id := Left_Opnd (Parent (N));
7213 Op2 : constant Node_Id := Right_Opnd (Parent (N));
7214 Lhs : constant Node_Id := Name (Parent (Parent (N)));
7217 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
7219 -- (not A) op (not B) can be reduced to a single call
7221 if N = Op1 and then Nkind (Op2) = N_Op_Not then
7224 elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
7227 -- A xor (not B) can also be special-cased
7229 elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
7236 A := Make_Defining_Identifier (Loc, Name_uA);
7237 B := Make_Defining_Identifier (Loc, Name_uB);
7238 J := Make_Defining_Identifier (Loc, Name_uJ);
7241 Make_Indexed_Component (Loc,
7242 Prefix => New_Reference_To (A, Loc),
7243 Expressions => New_List (New_Reference_To (J, Loc)));
7246 Make_Indexed_Component (Loc,
7247 Prefix => New_Reference_To (B, Loc),
7248 Expressions => New_List (New_Reference_To (J, Loc)));
7251 Make_Implicit_Loop_Statement (N,
7252 Identifier => Empty,
7255 Make_Iteration_Scheme (Loc,
7256 Loop_Parameter_Specification =>
7257 Make_Loop_Parameter_Specification (Loc,
7258 Defining_Identifier => J,
7259 Discrete_Subtype_Definition =>
7260 Make_Attribute_Reference (Loc,
7261 Prefix => Make_Identifier (Loc, Chars (A)),
7262 Attribute_Name => Name_Range))),
7264 Statements => New_List (
7265 Make_Assignment_Statement (Loc,
7267 Expression => Make_Op_Not (Loc, A_J))));
7269 Func_Name := Make_Temporary (Loc, 'N');
7270 Set_Is_Inlined (Func_Name);
7273 Make_Subprogram_Body (Loc,
7275 Make_Function_Specification (Loc,
7276 Defining_Unit_Name => Func_Name,
7277 Parameter_Specifications => New_List (
7278 Make_Parameter_Specification (Loc,
7279 Defining_Identifier => A,
7280 Parameter_Type => New_Reference_To (Typ, Loc))),
7281 Result_Definition => New_Reference_To (Typ, Loc)),
7283 Declarations => New_List (
7284 Make_Object_Declaration (Loc,
7285 Defining_Identifier => B,
7286 Object_Definition => New_Reference_To (Arr, Loc))),
7288 Handled_Statement_Sequence =>
7289 Make_Handled_Sequence_Of_Statements (Loc,
7290 Statements => New_List (
7292 Make_Simple_Return_Statement (Loc,
7293 Expression => Make_Identifier (Loc, Chars (B)))))));
7296 Make_Function_Call (Loc,
7297 Name => New_Reference_To (Func_Name, Loc),
7298 Parameter_Associations => New_List (Opnd)));
7300 Analyze_And_Resolve (N, Typ);
7301 end Expand_N_Op_Not;
7303 --------------------
7304 -- Expand_N_Op_Or --
7305 --------------------
7307 procedure Expand_N_Op_Or (N : Node_Id) is
7308 Typ : constant Entity_Id := Etype (N);
7311 Binary_Op_Validity_Checks (N);
7313 if Is_Array_Type (Etype (N)) then
7314 Expand_Boolean_Operator (N);
7316 elsif Is_Boolean_Type (Etype (N)) then
7318 -- Replace OR by OR ELSE if Short_Circuit_And_Or active and the type
7319 -- is standard Boolean (do not mess with AND that uses a non-standard
7320 -- Boolean type, because something strange is going on).
7322 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
7324 Make_Or_Else (Sloc (N),
7325 Left_Opnd => Relocate_Node (Left_Opnd (N)),
7326 Right_Opnd => Relocate_Node (Right_Opnd (N))));
7327 Analyze_And_Resolve (N, Typ);
7329 -- Otherwise, adjust conditions
7332 Adjust_Condition (Left_Opnd (N));
7333 Adjust_Condition (Right_Opnd (N));
7334 Set_Etype (N, Standard_Boolean);
7335 Adjust_Result_Type (N, Typ);
7338 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7339 Expand_Intrinsic_Call (N, Entity (N));
7344 ----------------------
7345 -- Expand_N_Op_Plus --
7346 ----------------------
7348 procedure Expand_N_Op_Plus (N : Node_Id) is
7350 Unary_Op_Validity_Checks (N);
7351 end Expand_N_Op_Plus;
7353 ---------------------
7354 -- Expand_N_Op_Rem --
7355 ---------------------
7357 procedure Expand_N_Op_Rem (N : Node_Id) is
7358 Loc : constant Source_Ptr := Sloc (N);
7359 Typ : constant Entity_Id := Etype (N);
7361 Left : constant Node_Id := Left_Opnd (N);
7362 Right : constant Node_Id := Right_Opnd (N);
7370 -- Set if corresponding operand can be negative
7372 pragma Unreferenced (Hi);
7375 Binary_Op_Validity_Checks (N);
7377 if Is_Integer_Type (Etype (N)) then
7378 Apply_Divide_Check (N);
7381 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
7382 -- but it is useful with other back ends (e.g. AAMP), and is certainly
7385 if Is_Integer_Type (Etype (N))
7386 and then Compile_Time_Known_Value (Right)
7387 and then Expr_Value (Right) = Uint_1
7389 -- Call Remove_Side_Effects to ensure that any side effects in the
7390 -- ignored left operand (in particular function calls to user defined
7391 -- functions) are properly executed.
7393 Remove_Side_Effects (Left);
7395 Rewrite (N, Make_Integer_Literal (Loc, 0));
7396 Analyze_And_Resolve (N, Typ);
7400 -- Deal with annoying case of largest negative number remainder minus
7401 -- one. Gigi does not handle this case correctly, because it generates
7402 -- a divide instruction which may trap in this case.
7404 -- In fact the check is quite easy, if the right operand is -1, then
7405 -- the remainder is always 0, and we can just ignore the left operand
7406 -- completely in this case.
7408 Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
7409 Lneg := (not OK) or else Lo < 0;
7411 Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
7412 Rneg := (not OK) or else Lo < 0;
7414 -- We won't mess with trying to find out if the left operand can really
7415 -- be the largest negative number (that's a pain in the case of private
7416 -- types and this is really marginal). We will just assume that we need
7417 -- the test if the left operand can be negative at all.
7419 if Lneg and Rneg then
7421 Make_Conditional_Expression (Loc,
7422 Expressions => New_List (
7424 Left_Opnd => Duplicate_Subexpr (Right),
7426 Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
7428 Unchecked_Convert_To (Typ,
7429 Make_Integer_Literal (Loc, Uint_0)),
7431 Relocate_Node (N))));
7433 Set_Analyzed (Next (Next (First (Expressions (N)))));
7434 Analyze_And_Resolve (N, Typ);
7436 end Expand_N_Op_Rem;
7438 -----------------------------
7439 -- Expand_N_Op_Rotate_Left --
7440 -----------------------------
7442 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
7444 Binary_Op_Validity_Checks (N);
7445 end Expand_N_Op_Rotate_Left;
7447 ------------------------------
7448 -- Expand_N_Op_Rotate_Right --
7449 ------------------------------
7451 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
7453 Binary_Op_Validity_Checks (N);
7454 end Expand_N_Op_Rotate_Right;
7456 ----------------------------
7457 -- Expand_N_Op_Shift_Left --
7458 ----------------------------
7460 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
7462 Binary_Op_Validity_Checks (N);
7463 end Expand_N_Op_Shift_Left;
7465 -----------------------------
7466 -- Expand_N_Op_Shift_Right --
7467 -----------------------------
7469 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
7471 Binary_Op_Validity_Checks (N);
7472 end Expand_N_Op_Shift_Right;
7474 ----------------------------------------
7475 -- Expand_N_Op_Shift_Right_Arithmetic --
7476 ----------------------------------------
7478 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
7480 Binary_Op_Validity_Checks (N);
7481 end Expand_N_Op_Shift_Right_Arithmetic;
7483 --------------------------
7484 -- Expand_N_Op_Subtract --
7485 --------------------------
7487 procedure Expand_N_Op_Subtract (N : Node_Id) is
7488 Typ : constant Entity_Id := Etype (N);
7491 Binary_Op_Validity_Checks (N);
7493 -- N - 0 = N for integer types
7495 if Is_Integer_Type (Typ)
7496 and then Compile_Time_Known_Value (Right_Opnd (N))
7497 and then Expr_Value (Right_Opnd (N)) = 0
7499 Rewrite (N, Left_Opnd (N));
7503 -- Arithmetic overflow checks for signed integer/fixed point types
7505 if Is_Signed_Integer_Type (Typ)
7507 Is_Fixed_Point_Type (Typ)
7509 Apply_Arithmetic_Overflow_Check (N);
7511 -- VAX floating-point types case
7513 elsif Vax_Float (Typ) then
7514 Expand_Vax_Arith (N);
7516 end Expand_N_Op_Subtract;
7518 ---------------------
7519 -- Expand_N_Op_Xor --
7520 ---------------------
7522 procedure Expand_N_Op_Xor (N : Node_Id) is
7523 Typ : constant Entity_Id := Etype (N);
7526 Binary_Op_Validity_Checks (N);
7528 if Is_Array_Type (Etype (N)) then
7529 Expand_Boolean_Operator (N);
7531 elsif Is_Boolean_Type (Etype (N)) then
7532 Adjust_Condition (Left_Opnd (N));
7533 Adjust_Condition (Right_Opnd (N));
7534 Set_Etype (N, Standard_Boolean);
7535 Adjust_Result_Type (N, Typ);
7537 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7538 Expand_Intrinsic_Call (N, Entity (N));
7541 end Expand_N_Op_Xor;
7543 ----------------------
7544 -- Expand_N_Or_Else --
7545 ----------------------
7547 procedure Expand_N_Or_Else (N : Node_Id)
7548 renames Expand_Short_Circuit_Operator;
7550 -----------------------------------
7551 -- Expand_N_Qualified_Expression --
7552 -----------------------------------
7554 procedure Expand_N_Qualified_Expression (N : Node_Id) is
7555 Operand : constant Node_Id := Expression (N);
7556 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
7559 -- Do validity check if validity checking operands
7561 if Validity_Checks_On
7562 and then Validity_Check_Operands
7564 Ensure_Valid (Operand);
7567 -- Apply possible constraint check
7569 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
7571 if Do_Range_Check (Operand) then
7572 Set_Do_Range_Check (Operand, False);
7573 Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
7575 end Expand_N_Qualified_Expression;
7577 ------------------------------------
7578 -- Expand_N_Quantified_Expression --
7579 ------------------------------------
7583 -- for all X in range => Cond
7588 -- for X in range loop
7595 -- Conversely, an existentially quantified expression:
7597 -- for some X in range => Cond
7602 -- for X in range loop
7609 -- In both cases, the iteration may be over a container in which case it is
7610 -- given by an iterator specification, not a loop parameter specification.
7612 procedure Expand_N_Quantified_Expression (N : Node_Id) is
7613 Loc : constant Source_Ptr := Sloc (N);
7614 Is_Universal : constant Boolean := All_Present (N);
7615 Actions : constant List_Id := New_List;
7616 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
7624 Make_Object_Declaration (Loc,
7625 Defining_Identifier => Tnn,
7626 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
7628 New_Occurrence_Of (Boolean_Literals (Is_Universal), Loc));
7629 Append_To (Actions, Decl);
7631 Cond := Relocate_Node (Condition (N));
7633 -- Reset flag analyzed in the condition to force its analysis. Required
7634 -- since the previous analysis was done with expansion disabled (see
7635 -- Resolve_Quantified_Expression) and hence checks were not inserted
7636 -- and record comparisons have not been expanded.
7638 Reset_Analyzed_Flags (Cond);
7640 if Is_Universal then
7641 Cond := Make_Op_Not (Loc, Cond);
7645 Make_Implicit_If_Statement (N,
7647 Then_Statements => New_List (
7648 Make_Assignment_Statement (Loc,
7649 Name => New_Occurrence_Of (Tnn, Loc),
7651 New_Occurrence_Of (Boolean_Literals (not Is_Universal), Loc)),
7652 Make_Exit_Statement (Loc)));
7654 if Present (Loop_Parameter_Specification (N)) then
7656 Make_Iteration_Scheme (Loc,
7657 Loop_Parameter_Specification =>
7658 Loop_Parameter_Specification (N));
7661 Make_Iteration_Scheme (Loc,
7662 Iterator_Specification => Iterator_Specification (N));
7666 Make_Loop_Statement (Loc,
7667 Iteration_Scheme => I_Scheme,
7668 Statements => New_List (Test),
7669 End_Label => Empty));
7671 -- The components of the scheme have already been analyzed, and the loop
7672 -- parameter declaration has been processed.
7674 Set_Analyzed (Iteration_Scheme (Last (Actions)));
7677 Make_Expression_With_Actions (Loc,
7678 Expression => New_Occurrence_Of (Tnn, Loc),
7679 Actions => Actions));
7681 Analyze_And_Resolve (N, Standard_Boolean);
7682 end Expand_N_Quantified_Expression;
7684 ---------------------------------
7685 -- Expand_N_Selected_Component --
7686 ---------------------------------
7688 -- If the selector is a discriminant of a concurrent object, rewrite the
7689 -- prefix to denote the corresponding record type.
7691 procedure Expand_N_Selected_Component (N : Node_Id) is
7692 Loc : constant Source_Ptr := Sloc (N);
7693 Par : constant Node_Id := Parent (N);
7694 P : constant Node_Id := Prefix (N);
7695 Ptyp : Entity_Id := Underlying_Type (Etype (P));
7701 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
7702 -- Gigi needs a temporary for prefixes that depend on a discriminant,
7703 -- unless the context of an assignment can provide size information.
7704 -- Don't we have a general routine that does this???
7706 function Is_Subtype_Declaration return Boolean;
7707 -- The replacement of a discriminant reference by its value is required
7708 -- if this is part of the initialization of an temporary generated by a
7709 -- change of representation. This shows up as the construction of a
7710 -- discriminant constraint for a subtype declared at the same point as
7711 -- the entity in the prefix of the selected component. We recognize this
7712 -- case when the context of the reference is:
7713 -- subtype ST is T(Obj.D);
7714 -- where the entity for Obj comes from source, and ST has the same sloc.
7716 -----------------------
7717 -- In_Left_Hand_Side --
7718 -----------------------
7720 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
7722 return (Nkind (Parent (Comp)) = N_Assignment_Statement
7723 and then Comp = Name (Parent (Comp)))
7724 or else (Present (Parent (Comp))
7725 and then Nkind (Parent (Comp)) in N_Subexpr
7726 and then In_Left_Hand_Side (Parent (Comp)));
7727 end In_Left_Hand_Side;
7729 -----------------------------
7730 -- Is_Subtype_Declaration --
7731 -----------------------------
7733 function Is_Subtype_Declaration return Boolean is
7734 Par : constant Node_Id := Parent (N);
7737 Nkind (Par) = N_Index_Or_Discriminant_Constraint
7738 and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration
7739 and then Comes_From_Source (Entity (Prefix (N)))
7740 and then Sloc (Par) = Sloc (Entity (Prefix (N)));
7741 end Is_Subtype_Declaration;
7743 -- Start of processing for Expand_N_Selected_Component
7746 -- Insert explicit dereference if required
7748 if Is_Access_Type (Ptyp) then
7749 Insert_Explicit_Dereference (P);
7750 Analyze_And_Resolve (P, Designated_Type (Ptyp));
7752 if Ekind (Etype (P)) = E_Private_Subtype
7753 and then Is_For_Access_Subtype (Etype (P))
7755 Set_Etype (P, Base_Type (Etype (P)));
7761 -- Deal with discriminant check required
7763 if Do_Discriminant_Check (N) then
7765 -- Present the discriminant checking function to the backend, so that
7766 -- it can inline the call to the function.
7769 (Discriminant_Checking_Func
7770 (Original_Record_Component (Entity (Selector_Name (N)))));
7772 -- Now reset the flag and generate the call
7774 Set_Do_Discriminant_Check (N, False);
7775 Generate_Discriminant_Check (N);
7778 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7779 -- function, then additional actuals must be passed.
7781 if Ada_Version >= Ada_2005
7782 and then Is_Build_In_Place_Function_Call (P)
7784 Make_Build_In_Place_Call_In_Anonymous_Context (P);
7787 -- Gigi cannot handle unchecked conversions that are the prefix of a
7788 -- selected component with discriminants. This must be checked during
7789 -- expansion, because during analysis the type of the selector is not
7790 -- known at the point the prefix is analyzed. If the conversion is the
7791 -- target of an assignment, then we cannot force the evaluation.
7793 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
7794 and then Has_Discriminants (Etype (N))
7795 and then not In_Left_Hand_Side (N)
7797 Force_Evaluation (Prefix (N));
7800 -- Remaining processing applies only if selector is a discriminant
7802 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
7804 -- If the selector is a discriminant of a constrained record type,
7805 -- we may be able to rewrite the expression with the actual value
7806 -- of the discriminant, a useful optimization in some cases.
7808 if Is_Record_Type (Ptyp)
7809 and then Has_Discriminants (Ptyp)
7810 and then Is_Constrained (Ptyp)
7812 -- Do this optimization for discrete types only, and not for
7813 -- access types (access discriminants get us into trouble!)
7815 if not Is_Discrete_Type (Etype (N)) then
7818 -- Don't do this on the left hand of an assignment statement.
7819 -- Normally one would think that references like this would not
7820 -- occur, but they do in generated code, and mean that we really
7821 -- do want to assign the discriminant!
7823 elsif Nkind (Par) = N_Assignment_Statement
7824 and then Name (Par) = N
7828 -- Don't do this optimization for the prefix of an attribute or
7829 -- the name of an object renaming declaration since these are
7830 -- contexts where we do not want the value anyway.
7832 elsif (Nkind (Par) = N_Attribute_Reference
7833 and then Prefix (Par) = N)
7834 or else Is_Renamed_Object (N)
7838 -- Don't do this optimization if we are within the code for a
7839 -- discriminant check, since the whole point of such a check may
7840 -- be to verify the condition on which the code below depends!
7842 elsif Is_In_Discriminant_Check (N) then
7845 -- Green light to see if we can do the optimization. There is
7846 -- still one condition that inhibits the optimization below but
7847 -- now is the time to check the particular discriminant.
7850 -- Loop through discriminants to find the matching discriminant
7851 -- constraint to see if we can copy it.
7853 Disc := First_Discriminant (Ptyp);
7854 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
7855 Discr_Loop : while Present (Dcon) loop
7856 Dval := Node (Dcon);
7858 -- Check if this is the matching discriminant and if the
7859 -- discriminant value is simple enough to make sense to
7860 -- copy. We don't want to copy complex expressions, and
7861 -- indeed to do so can cause trouble (before we put in
7862 -- this guard, a discriminant expression containing an
7863 -- AND THEN was copied, causing problems for coverage
7866 -- However, if the reference is part of the initialization
7867 -- code generated for an object declaration, we must use
7868 -- the discriminant value from the subtype constraint,
7869 -- because the selected component may be a reference to the
7870 -- object being initialized, whose discriminant is not yet
7871 -- set. This only happens in complex cases involving changes
7872 -- or representation.
7874 if Disc = Entity (Selector_Name (N))
7875 and then (Is_Entity_Name (Dval)
7876 or else Compile_Time_Known_Value (Dval)
7877 or else Is_Subtype_Declaration)
7879 -- Here we have the matching discriminant. Check for
7880 -- the case of a discriminant of a component that is
7881 -- constrained by an outer discriminant, which cannot
7882 -- be optimized away.
7884 if Denotes_Discriminant
7885 (Dval, Check_Concurrent => True)
7889 elsif Nkind (Original_Node (Dval)) = N_Selected_Component
7891 Denotes_Discriminant
7892 (Selector_Name (Original_Node (Dval)), True)
7896 -- Do not retrieve value if constraint is not static. It
7897 -- is generally not useful, and the constraint may be a
7898 -- rewritten outer discriminant in which case it is in
7901 elsif Is_Entity_Name (Dval)
7902 and then Nkind (Parent (Entity (Dval))) =
7903 N_Object_Declaration
7904 and then Present (Expression (Parent (Entity (Dval))))
7906 not Is_Static_Expression
7907 (Expression (Parent (Entity (Dval))))
7911 -- In the context of a case statement, the expression may
7912 -- have the base type of the discriminant, and we need to
7913 -- preserve the constraint to avoid spurious errors on
7916 elsif Nkind (Parent (N)) = N_Case_Statement
7917 and then Etype (Dval) /= Etype (Disc)
7920 Make_Qualified_Expression (Loc,
7922 New_Occurrence_Of (Etype (Disc), Loc),
7924 New_Copy_Tree (Dval)));
7925 Analyze_And_Resolve (N, Etype (Disc));
7927 -- In case that comes out as a static expression,
7928 -- reset it (a selected component is never static).
7930 Set_Is_Static_Expression (N, False);
7933 -- Otherwise we can just copy the constraint, but the
7934 -- result is certainly not static! In some cases the
7935 -- discriminant constraint has been analyzed in the
7936 -- context of the original subtype indication, but for
7937 -- itypes the constraint might not have been analyzed
7938 -- yet, and this must be done now.
7941 Rewrite (N, New_Copy_Tree (Dval));
7942 Analyze_And_Resolve (N);
7943 Set_Is_Static_Expression (N, False);
7949 Next_Discriminant (Disc);
7950 end loop Discr_Loop;
7952 -- Note: the above loop should always find a matching
7953 -- discriminant, but if it does not, we just missed an
7954 -- optimization due to some glitch (perhaps a previous
7955 -- error), so ignore.
7960 -- The only remaining processing is in the case of a discriminant of
7961 -- a concurrent object, where we rewrite the prefix to denote the
7962 -- corresponding record type. If the type is derived and has renamed
7963 -- discriminants, use corresponding discriminant, which is the one
7964 -- that appears in the corresponding record.
7966 if not Is_Concurrent_Type (Ptyp) then
7970 Disc := Entity (Selector_Name (N));
7972 if Is_Derived_Type (Ptyp)
7973 and then Present (Corresponding_Discriminant (Disc))
7975 Disc := Corresponding_Discriminant (Disc);
7979 Make_Selected_Component (Loc,
7981 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
7983 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
7988 end Expand_N_Selected_Component;
7990 --------------------
7991 -- Expand_N_Slice --
7992 --------------------
7994 procedure Expand_N_Slice (N : Node_Id) is
7995 Loc : constant Source_Ptr := Sloc (N);
7996 Typ : constant Entity_Id := Etype (N);
7997 Pfx : constant Node_Id := Prefix (N);
7998 Ptp : Entity_Id := Etype (Pfx);
8000 function Is_Procedure_Actual (N : Node_Id) return Boolean;
8001 -- Check whether the argument is an actual for a procedure call, in
8002 -- which case the expansion of a bit-packed slice is deferred until the
8003 -- call itself is expanded. The reason this is required is that we might
8004 -- have an IN OUT or OUT parameter, and the copy out is essential, and
8005 -- that copy out would be missed if we created a temporary here in
8006 -- Expand_N_Slice. Note that we don't bother to test specifically for an
8007 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
8008 -- is harmless to defer expansion in the IN case, since the call
8009 -- processing will still generate the appropriate copy in operation,
8010 -- which will take care of the slice.
8012 procedure Make_Temporary_For_Slice;
8013 -- Create a named variable for the value of the slice, in cases where
8014 -- the back-end cannot handle it properly, e.g. when packed types or
8015 -- unaligned slices are involved.
8017 -------------------------
8018 -- Is_Procedure_Actual --
8019 -------------------------
8021 function Is_Procedure_Actual (N : Node_Id) return Boolean is
8022 Par : Node_Id := Parent (N);
8026 -- If our parent is a procedure call we can return
8028 if Nkind (Par) = N_Procedure_Call_Statement then
8031 -- If our parent is a type conversion, keep climbing the tree,
8032 -- since a type conversion can be a procedure actual. Also keep
8033 -- climbing if parameter association or a qualified expression,
8034 -- since these are additional cases that do can appear on
8035 -- procedure actuals.
8037 elsif Nkind_In (Par, N_Type_Conversion,
8038 N_Parameter_Association,
8039 N_Qualified_Expression)
8041 Par := Parent (Par);
8043 -- Any other case is not what we are looking for
8049 end Is_Procedure_Actual;
8051 ------------------------------
8052 -- Make_Temporary_For_Slice --
8053 ------------------------------
8055 procedure Make_Temporary_For_Slice is
8057 Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
8061 Make_Object_Declaration (Loc,
8062 Defining_Identifier => Ent,
8063 Object_Definition => New_Occurrence_Of (Typ, Loc));
8065 Set_No_Initialization (Decl);
8067 Insert_Actions (N, New_List (
8069 Make_Assignment_Statement (Loc,
8070 Name => New_Occurrence_Of (Ent, Loc),
8071 Expression => Relocate_Node (N))));
8073 Rewrite (N, New_Occurrence_Of (Ent, Loc));
8074 Analyze_And_Resolve (N, Typ);
8075 end Make_Temporary_For_Slice;
8077 -- Start of processing for Expand_N_Slice
8080 -- Special handling for access types
8082 if Is_Access_Type (Ptp) then
8084 Ptp := Designated_Type (Ptp);
8087 Make_Explicit_Dereference (Sloc (N),
8088 Prefix => Relocate_Node (Pfx)));
8090 Analyze_And_Resolve (Pfx, Ptp);
8093 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
8094 -- function, then additional actuals must be passed.
8096 if Ada_Version >= Ada_2005
8097 and then Is_Build_In_Place_Function_Call (Pfx)
8099 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
8102 -- The remaining case to be handled is packed slices. We can leave
8103 -- packed slices as they are in the following situations:
8105 -- 1. Right or left side of an assignment (we can handle this
8106 -- situation correctly in the assignment statement expansion).
8108 -- 2. Prefix of indexed component (the slide is optimized away in this
8109 -- case, see the start of Expand_N_Slice.)
8111 -- 3. Object renaming declaration, since we want the name of the
8112 -- slice, not the value.
8114 -- 4. Argument to procedure call, since copy-in/copy-out handling may
8115 -- be required, and this is handled in the expansion of call
8118 -- 5. Prefix of an address attribute (this is an error which is caught
8119 -- elsewhere, and the expansion would interfere with generating the
8122 if not Is_Packed (Typ) then
8124 -- Apply transformation for actuals of a function call, where
8125 -- Expand_Actuals is not used.
8127 if Nkind (Parent (N)) = N_Function_Call
8128 and then Is_Possibly_Unaligned_Slice (N)
8130 Make_Temporary_For_Slice;
8133 elsif Nkind (Parent (N)) = N_Assignment_Statement
8134 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
8135 and then Parent (N) = Name (Parent (Parent (N))))
8139 elsif Nkind (Parent (N)) = N_Indexed_Component
8140 or else Is_Renamed_Object (N)
8141 or else Is_Procedure_Actual (N)
8145 elsif Nkind (Parent (N)) = N_Attribute_Reference
8146 and then Attribute_Name (Parent (N)) = Name_Address
8151 Make_Temporary_For_Slice;
8155 ------------------------------
8156 -- Expand_N_Type_Conversion --
8157 ------------------------------
8159 procedure Expand_N_Type_Conversion (N : Node_Id) is
8160 Loc : constant Source_Ptr := Sloc (N);
8161 Operand : constant Node_Id := Expression (N);
8162 Target_Type : constant Entity_Id := Etype (N);
8163 Operand_Type : Entity_Id := Etype (Operand);
8165 procedure Handle_Changed_Representation;
8166 -- This is called in the case of record and array type conversions to
8167 -- see if there is a change of representation to be handled. Change of
8168 -- representation is actually handled at the assignment statement level,
8169 -- and what this procedure does is rewrite node N conversion as an
8170 -- assignment to temporary. If there is no change of representation,
8171 -- then the conversion node is unchanged.
8173 procedure Raise_Accessibility_Error;
8174 -- Called when we know that an accessibility check will fail. Rewrites
8175 -- node N to an appropriate raise statement and outputs warning msgs.
8176 -- The Etype of the raise node is set to Target_Type.
8178 procedure Real_Range_Check;
8179 -- Handles generation of range check for real target value
8181 -----------------------------------
8182 -- Handle_Changed_Representation --
8183 -----------------------------------
8185 procedure Handle_Changed_Representation is
8194 -- Nothing else to do if no change of representation
8196 if Same_Representation (Operand_Type, Target_Type) then
8199 -- The real change of representation work is done by the assignment
8200 -- statement processing. So if this type conversion is appearing as
8201 -- the expression of an assignment statement, nothing needs to be
8202 -- done to the conversion.
8204 elsif Nkind (Parent (N)) = N_Assignment_Statement then
8207 -- Otherwise we need to generate a temporary variable, and do the
8208 -- change of representation assignment into that temporary variable.
8209 -- The conversion is then replaced by a reference to this variable.
8214 -- If type is unconstrained we have to add a constraint, copied
8215 -- from the actual value of the left hand side.
8217 if not Is_Constrained (Target_Type) then
8218 if Has_Discriminants (Operand_Type) then
8219 Disc := First_Discriminant (Operand_Type);
8221 if Disc /= First_Stored_Discriminant (Operand_Type) then
8222 Disc := First_Stored_Discriminant (Operand_Type);
8226 while Present (Disc) loop
8228 Make_Selected_Component (Loc,
8230 Duplicate_Subexpr_Move_Checks (Operand),
8232 Make_Identifier (Loc, Chars (Disc))));
8233 Next_Discriminant (Disc);
8236 elsif Is_Array_Type (Operand_Type) then
8237 N_Ix := First_Index (Target_Type);
8240 for J in 1 .. Number_Dimensions (Operand_Type) loop
8242 -- We convert the bounds explicitly. We use an unchecked
8243 -- conversion because bounds checks are done elsewhere.
8248 Unchecked_Convert_To (Etype (N_Ix),
8249 Make_Attribute_Reference (Loc,
8251 Duplicate_Subexpr_No_Checks
8252 (Operand, Name_Req => True),
8253 Attribute_Name => Name_First,
8254 Expressions => New_List (
8255 Make_Integer_Literal (Loc, J)))),
8258 Unchecked_Convert_To (Etype (N_Ix),
8259 Make_Attribute_Reference (Loc,
8261 Duplicate_Subexpr_No_Checks
8262 (Operand, Name_Req => True),
8263 Attribute_Name => Name_Last,
8264 Expressions => New_List (
8265 Make_Integer_Literal (Loc, J))))));
8272 Odef := New_Occurrence_Of (Target_Type, Loc);
8274 if Present (Cons) then
8276 Make_Subtype_Indication (Loc,
8277 Subtype_Mark => Odef,
8279 Make_Index_Or_Discriminant_Constraint (Loc,
8280 Constraints => Cons));
8283 Temp := Make_Temporary (Loc, 'C');
8285 Make_Object_Declaration (Loc,
8286 Defining_Identifier => Temp,
8287 Object_Definition => Odef);
8289 Set_No_Initialization (Decl, True);
8291 -- Insert required actions. It is essential to suppress checks
8292 -- since we have suppressed default initialization, which means
8293 -- that the variable we create may have no discriminants.
8298 Make_Assignment_Statement (Loc,
8299 Name => New_Occurrence_Of (Temp, Loc),
8300 Expression => Relocate_Node (N))),
8301 Suppress => All_Checks);
8303 Rewrite (N, New_Occurrence_Of (Temp, Loc));
8306 end Handle_Changed_Representation;
8308 -------------------------------
8309 -- Raise_Accessibility_Error --
8310 -------------------------------
8312 procedure Raise_Accessibility_Error is
8315 Make_Raise_Program_Error (Sloc (N),
8316 Reason => PE_Accessibility_Check_Failed));
8317 Set_Etype (N, Target_Type);
8319 Error_Msg_N ("?accessibility check failure", N);
8321 ("\?& will be raised at run time", N, Standard_Program_Error);
8322 end Raise_Accessibility_Error;
8324 ----------------------
8325 -- Real_Range_Check --
8326 ----------------------
8328 -- Case of conversions to floating-point or fixed-point. If range checks
8329 -- are enabled and the target type has a range constraint, we convert:
8335 -- Tnn : typ'Base := typ'Base (x);
8336 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
8339 -- This is necessary when there is a conversion of integer to float or
8340 -- to fixed-point to ensure that the correct checks are made. It is not
8341 -- necessary for float to float where it is enough to simply set the
8342 -- Do_Range_Check flag.
8344 procedure Real_Range_Check is
8345 Btyp : constant Entity_Id := Base_Type (Target_Type);
8346 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
8347 Hi : constant Node_Id := Type_High_Bound (Target_Type);
8348 Xtyp : constant Entity_Id := Etype (Operand);
8353 -- Nothing to do if conversion was rewritten
8355 if Nkind (N) /= N_Type_Conversion then
8359 -- Nothing to do if range checks suppressed, or target has the same
8360 -- range as the base type (or is the base type).
8362 if Range_Checks_Suppressed (Target_Type)
8363 or else (Lo = Type_Low_Bound (Btyp)
8365 Hi = Type_High_Bound (Btyp))
8370 -- Nothing to do if expression is an entity on which checks have been
8373 if Is_Entity_Name (Operand)
8374 and then Range_Checks_Suppressed (Entity (Operand))
8379 -- Nothing to do if bounds are all static and we can tell that the
8380 -- expression is within the bounds of the target. Note that if the
8381 -- operand is of an unconstrained floating-point type, then we do
8382 -- not trust it to be in range (might be infinite)
8385 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
8386 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
8389 if (not Is_Floating_Point_Type (Xtyp)
8390 or else Is_Constrained (Xtyp))
8391 and then Compile_Time_Known_Value (S_Lo)
8392 and then Compile_Time_Known_Value (S_Hi)
8393 and then Compile_Time_Known_Value (Hi)
8394 and then Compile_Time_Known_Value (Lo)
8397 D_Lov : constant Ureal := Expr_Value_R (Lo);
8398 D_Hiv : constant Ureal := Expr_Value_R (Hi);
8403 if Is_Real_Type (Xtyp) then
8404 S_Lov := Expr_Value_R (S_Lo);
8405 S_Hiv := Expr_Value_R (S_Hi);
8407 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
8408 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
8412 and then S_Lov >= D_Lov
8413 and then S_Hiv <= D_Hiv
8415 Set_Do_Range_Check (Operand, False);
8422 -- For float to float conversions, we are done
8424 if Is_Floating_Point_Type (Xtyp)
8426 Is_Floating_Point_Type (Btyp)
8431 -- Otherwise rewrite the conversion as described above
8433 Conv := Relocate_Node (N);
8434 Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
8435 Set_Etype (Conv, Btyp);
8437 -- Enable overflow except for case of integer to float conversions,
8438 -- where it is never required, since we can never have overflow in
8441 if not Is_Integer_Type (Etype (Operand)) then
8442 Enable_Overflow_Check (Conv);
8445 Tnn := Make_Temporary (Loc, 'T', Conv);
8447 Insert_Actions (N, New_List (
8448 Make_Object_Declaration (Loc,
8449 Defining_Identifier => Tnn,
8450 Object_Definition => New_Occurrence_Of (Btyp, Loc),
8451 Constant_Present => True,
8452 Expression => Conv),
8454 Make_Raise_Constraint_Error (Loc,
8459 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8461 Make_Attribute_Reference (Loc,
8462 Attribute_Name => Name_First,
8464 New_Occurrence_Of (Target_Type, Loc))),
8468 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8470 Make_Attribute_Reference (Loc,
8471 Attribute_Name => Name_Last,
8473 New_Occurrence_Of (Target_Type, Loc)))),
8474 Reason => CE_Range_Check_Failed)));
8476 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
8477 Analyze_And_Resolve (N, Btyp);
8478 end Real_Range_Check;
8480 -- Start of processing for Expand_N_Type_Conversion
8483 -- Nothing at all to do if conversion is to the identical type so remove
8484 -- the conversion completely, it is useless, except that it may carry
8485 -- an Assignment_OK attribute, which must be propagated to the operand.
8487 if Operand_Type = Target_Type then
8488 if Assignment_OK (N) then
8489 Set_Assignment_OK (Operand);
8492 Rewrite (N, Relocate_Node (Operand));
8496 -- Nothing to do if this is the second argument of read. This is a
8497 -- "backwards" conversion that will be handled by the specialized code
8498 -- in attribute processing.
8500 if Nkind (Parent (N)) = N_Attribute_Reference
8501 and then Attribute_Name (Parent (N)) = Name_Read
8502 and then Next (First (Expressions (Parent (N)))) = N
8507 -- Check for case of converting to a type that has an invariant
8508 -- associated with it. This required an invariant check. We convert
8514 -- do invariant_check (typ (expr)) in typ (expr);
8516 -- using Duplicate_Subexpr to avoid multiple side effects
8518 -- Note: the Comes_From_Source check, and then the resetting of this
8519 -- flag prevents what would otherwise be an infinite recursion.
8521 if Has_Invariants (Target_Type)
8522 and then Present (Invariant_Procedure (Target_Type))
8523 and then Comes_From_Source (N)
8525 Set_Comes_From_Source (N, False);
8527 Make_Expression_With_Actions (Loc,
8528 Actions => New_List (
8529 Make_Invariant_Call (Duplicate_Subexpr (N))),
8530 Expression => Duplicate_Subexpr_No_Checks (N)));
8531 Analyze_And_Resolve (N, Target_Type);
8535 -- Here if we may need to expand conversion
8537 -- If the operand of the type conversion is an arithmetic operation on
8538 -- signed integers, and the based type of the signed integer type in
8539 -- question is smaller than Standard.Integer, we promote both of the
8540 -- operands to type Integer.
8542 -- For example, if we have
8544 -- target-type (opnd1 + opnd2)
8546 -- and opnd1 and opnd2 are of type short integer, then we rewrite
8549 -- target-type (integer(opnd1) + integer(opnd2))
8551 -- We do this because we are always allowed to compute in a larger type
8552 -- if we do the right thing with the result, and in this case we are
8553 -- going to do a conversion which will do an appropriate check to make
8554 -- sure that things are in range of the target type in any case. This
8555 -- avoids some unnecessary intermediate overflows.
8557 -- We might consider a similar transformation in the case where the
8558 -- target is a real type or a 64-bit integer type, and the operand
8559 -- is an arithmetic operation using a 32-bit integer type. However,
8560 -- we do not bother with this case, because it could cause significant
8561 -- inefficiencies on 32-bit machines. On a 64-bit machine it would be
8562 -- much cheaper, but we don't want different behavior on 32-bit and
8563 -- 64-bit machines. Note that the exclusion of the 64-bit case also
8564 -- handles the configurable run-time cases where 64-bit arithmetic
8565 -- may simply be unavailable.
8567 -- Note: this circuit is partially redundant with respect to the circuit
8568 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
8569 -- the processing here. Also we still need the Checks circuit, since we
8570 -- have to be sure not to generate junk overflow checks in the first
8571 -- place, since it would be trick to remove them here!
8573 if Integer_Promotion_Possible (N) then
8575 -- All conditions met, go ahead with transformation
8583 Make_Type_Conversion (Loc,
8584 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8585 Expression => Relocate_Node (Right_Opnd (Operand)));
8587 Opnd := New_Op_Node (Nkind (Operand), Loc);
8588 Set_Right_Opnd (Opnd, R);
8590 if Nkind (Operand) in N_Binary_Op then
8592 Make_Type_Conversion (Loc,
8593 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8594 Expression => Relocate_Node (Left_Opnd (Operand)));
8596 Set_Left_Opnd (Opnd, L);
8600 Make_Type_Conversion (Loc,
8601 Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
8602 Expression => Opnd));
8604 Analyze_And_Resolve (N, Target_Type);
8609 -- Do validity check if validity checking operands
8611 if Validity_Checks_On
8612 and then Validity_Check_Operands
8614 Ensure_Valid (Operand);
8617 -- Special case of converting from non-standard boolean type
8619 if Is_Boolean_Type (Operand_Type)
8620 and then (Nonzero_Is_True (Operand_Type))
8622 Adjust_Condition (Operand);
8623 Set_Etype (Operand, Standard_Boolean);
8624 Operand_Type := Standard_Boolean;
8627 -- Case of converting to an access type
8629 if Is_Access_Type (Target_Type) then
8631 -- Apply an accessibility check when the conversion operand is an
8632 -- access parameter (or a renaming thereof), unless conversion was
8633 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
8634 -- Note that other checks may still need to be applied below (such
8635 -- as tagged type checks).
8637 if Is_Entity_Name (Operand)
8639 (Is_Formal (Entity (Operand))
8641 (Present (Renamed_Object (Entity (Operand)))
8642 and then Is_Entity_Name (Renamed_Object (Entity (Operand)))
8644 (Entity (Renamed_Object (Entity (Operand))))))
8645 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
8646 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
8647 or else Attribute_Name (Original_Node (N)) = Name_Access)
8649 Apply_Accessibility_Check
8650 (Operand, Target_Type, Insert_Node => Operand);
8652 -- If the level of the operand type is statically deeper than the
8653 -- level of the target type, then force Program_Error. Note that this
8654 -- can only occur for cases where the attribute is within the body of
8655 -- an instantiation (otherwise the conversion will already have been
8656 -- rejected as illegal). Note: warnings are issued by the analyzer
8657 -- for the instance cases.
8659 elsif In_Instance_Body
8660 and then Type_Access_Level (Operand_Type) >
8661 Type_Access_Level (Target_Type)
8663 Raise_Accessibility_Error;
8665 -- When the operand is a selected access discriminant the check needs
8666 -- to be made against the level of the object denoted by the prefix
8667 -- of the selected name. Force Program_Error for this case as well
8668 -- (this accessibility violation can only happen if within the body
8669 -- of an instantiation).
8671 elsif In_Instance_Body
8672 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
8673 and then Nkind (Operand) = N_Selected_Component
8674 and then Object_Access_Level (Operand) >
8675 Type_Access_Level (Target_Type)
8677 Raise_Accessibility_Error;
8682 -- Case of conversions of tagged types and access to tagged types
8684 -- When needed, that is to say when the expression is class-wide, Add
8685 -- runtime a tag check for (strict) downward conversion by using the
8686 -- membership test, generating:
8688 -- [constraint_error when Operand not in Target_Type'Class]
8690 -- or in the access type case
8692 -- [constraint_error
8693 -- when Operand /= null
8694 -- and then Operand.all not in
8695 -- Designated_Type (Target_Type)'Class]
8697 if (Is_Access_Type (Target_Type)
8698 and then Is_Tagged_Type (Designated_Type (Target_Type)))
8699 or else Is_Tagged_Type (Target_Type)
8701 -- Do not do any expansion in the access type case if the parent is a
8702 -- renaming, since this is an error situation which will be caught by
8703 -- Sem_Ch8, and the expansion can interfere with this error check.
8705 if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
8709 -- Otherwise, proceed with processing tagged conversion
8711 Tagged_Conversion : declare
8712 Actual_Op_Typ : Entity_Id;
8713 Actual_Targ_Typ : Entity_Id;
8714 Make_Conversion : Boolean := False;
8715 Root_Op_Typ : Entity_Id;
8717 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
8718 -- Create a membership check to test whether Operand is a member
8719 -- of Targ_Typ. If the original Target_Type is an access, include
8720 -- a test for null value. The check is inserted at N.
8722 --------------------
8723 -- Make_Tag_Check --
8724 --------------------
8726 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
8731 -- [Constraint_Error
8732 -- when Operand /= null
8733 -- and then Operand.all not in Targ_Typ]
8735 if Is_Access_Type (Target_Type) then
8740 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8741 Right_Opnd => Make_Null (Loc)),
8746 Make_Explicit_Dereference (Loc,
8747 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
8748 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
8751 -- [Constraint_Error when Operand not in Targ_Typ]
8756 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8757 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
8761 Make_Raise_Constraint_Error (Loc,
8763 Reason => CE_Tag_Check_Failed));
8766 -- Start of processing for Tagged_Conversion
8769 -- Handle entities from the limited view
8771 if Is_Access_Type (Operand_Type) then
8773 Available_View (Designated_Type (Operand_Type));
8775 Actual_Op_Typ := Operand_Type;
8778 if Is_Access_Type (Target_Type) then
8780 Available_View (Designated_Type (Target_Type));
8782 Actual_Targ_Typ := Target_Type;
8785 Root_Op_Typ := Root_Type (Actual_Op_Typ);
8787 -- Ada 2005 (AI-251): Handle interface type conversion
8789 if Is_Interface (Actual_Op_Typ) then
8790 Expand_Interface_Conversion (N, Is_Static => False);
8794 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
8796 -- Create a runtime tag check for a downward class-wide type
8799 if Is_Class_Wide_Type (Actual_Op_Typ)
8800 and then Actual_Op_Typ /= Actual_Targ_Typ
8801 and then Root_Op_Typ /= Actual_Targ_Typ
8802 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ,
8803 Use_Full_View => True)
8805 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
8806 Make_Conversion := True;
8809 -- AI05-0073: If the result subtype of the function is defined
8810 -- by an access_definition designating a specific tagged type
8811 -- T, a check is made that the result value is null or the tag
8812 -- of the object designated by the result value identifies T.
8813 -- Constraint_Error is raised if this check fails.
8815 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
8818 Func_Typ : Entity_Id;
8821 -- Climb scope stack looking for the enclosing function
8823 Func := Current_Scope;
8824 while Present (Func)
8825 and then Ekind (Func) /= E_Function
8827 Func := Scope (Func);
8830 -- The function's return subtype must be defined using
8831 -- an access definition.
8833 if Nkind (Result_Definition (Parent (Func))) =
8836 Func_Typ := Directly_Designated_Type (Etype (Func));
8838 -- The return subtype denotes a specific tagged type,
8839 -- in other words, a non class-wide type.
8841 if Is_Tagged_Type (Func_Typ)
8842 and then not Is_Class_Wide_Type (Func_Typ)
8844 Make_Tag_Check (Actual_Targ_Typ);
8845 Make_Conversion := True;
8851 -- We have generated a tag check for either a class-wide type
8852 -- conversion or for AI05-0073.
8854 if Make_Conversion then
8859 Make_Unchecked_Type_Conversion (Loc,
8860 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
8861 Expression => Relocate_Node (Expression (N)));
8863 Analyze_And_Resolve (N, Target_Type);
8867 end Tagged_Conversion;
8869 -- Case of other access type conversions
8871 elsif Is_Access_Type (Target_Type) then
8872 Apply_Constraint_Check (Operand, Target_Type);
8874 -- Case of conversions from a fixed-point type
8876 -- These conversions require special expansion and processing, found in
8877 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
8878 -- since from a semantic point of view, these are simple integer
8879 -- conversions, which do not need further processing.
8881 elsif Is_Fixed_Point_Type (Operand_Type)
8882 and then not Conversion_OK (N)
8884 -- We should never see universal fixed at this case, since the
8885 -- expansion of the constituent divide or multiply should have
8886 -- eliminated the explicit mention of universal fixed.
8888 pragma Assert (Operand_Type /= Universal_Fixed);
8890 -- Check for special case of the conversion to universal real that
8891 -- occurs as a result of the use of a round attribute. In this case,
8892 -- the real type for the conversion is taken from the target type of
8893 -- the Round attribute and the result must be marked as rounded.
8895 if Target_Type = Universal_Real
8896 and then Nkind (Parent (N)) = N_Attribute_Reference
8897 and then Attribute_Name (Parent (N)) = Name_Round
8899 Set_Rounded_Result (N);
8900 Set_Etype (N, Etype (Parent (N)));
8903 -- Otherwise do correct fixed-conversion, but skip these if the
8904 -- Conversion_OK flag is set, because from a semantic point of view
8905 -- these are simple integer conversions needing no further processing
8906 -- (the backend will simply treat them as integers).
8908 if not Conversion_OK (N) then
8909 if Is_Fixed_Point_Type (Etype (N)) then
8910 Expand_Convert_Fixed_To_Fixed (N);
8913 elsif Is_Integer_Type (Etype (N)) then
8914 Expand_Convert_Fixed_To_Integer (N);
8917 pragma Assert (Is_Floating_Point_Type (Etype (N)));
8918 Expand_Convert_Fixed_To_Float (N);
8923 -- Case of conversions to a fixed-point type
8925 -- These conversions require special expansion and processing, found in
8926 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
8927 -- since from a semantic point of view, these are simple integer
8928 -- conversions, which do not need further processing.
8930 elsif Is_Fixed_Point_Type (Target_Type)
8931 and then not Conversion_OK (N)
8933 if Is_Integer_Type (Operand_Type) then
8934 Expand_Convert_Integer_To_Fixed (N);
8937 pragma Assert (Is_Floating_Point_Type (Operand_Type));
8938 Expand_Convert_Float_To_Fixed (N);
8942 -- Case of float-to-integer conversions
8944 -- We also handle float-to-fixed conversions with Conversion_OK set
8945 -- since semantically the fixed-point target is treated as though it
8946 -- were an integer in such cases.
8948 elsif Is_Floating_Point_Type (Operand_Type)
8950 (Is_Integer_Type (Target_Type)
8952 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
8954 -- One more check here, gcc is still not able to do conversions of
8955 -- this type with proper overflow checking, and so gigi is doing an
8956 -- approximation of what is required by doing floating-point compares
8957 -- with the end-point. But that can lose precision in some cases, and
8958 -- give a wrong result. Converting the operand to Universal_Real is
8959 -- helpful, but still does not catch all cases with 64-bit integers
8960 -- on targets with only 64-bit floats.
8962 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
8963 -- Can this code be removed ???
8965 if Do_Range_Check (Operand) then
8967 Make_Type_Conversion (Loc,
8969 New_Occurrence_Of (Universal_Real, Loc),
8971 Relocate_Node (Operand)));
8973 Set_Etype (Operand, Universal_Real);
8974 Enable_Range_Check (Operand);
8975 Set_Do_Range_Check (Expression (Operand), False);
8978 -- Case of array conversions
8980 -- Expansion of array conversions, add required length/range checks but
8981 -- only do this if there is no change of representation. For handling of
8982 -- this case, see Handle_Changed_Representation.
8984 elsif Is_Array_Type (Target_Type) then
8985 if Is_Constrained (Target_Type) then
8986 Apply_Length_Check (Operand, Target_Type);
8988 Apply_Range_Check (Operand, Target_Type);
8991 Handle_Changed_Representation;
8993 -- Case of conversions of discriminated types
8995 -- Add required discriminant checks if target is constrained. Again this
8996 -- change is skipped if we have a change of representation.
8998 elsif Has_Discriminants (Target_Type)
8999 and then Is_Constrained (Target_Type)
9001 Apply_Discriminant_Check (Operand, Target_Type);
9002 Handle_Changed_Representation;
9004 -- Case of all other record conversions. The only processing required
9005 -- is to check for a change of representation requiring the special
9006 -- assignment processing.
9008 elsif Is_Record_Type (Target_Type) then
9010 -- Ada 2005 (AI-216): Program_Error is raised when converting from
9011 -- a derived Unchecked_Union type to an unconstrained type that is
9012 -- not Unchecked_Union if the operand lacks inferable discriminants.
9014 if Is_Derived_Type (Operand_Type)
9015 and then Is_Unchecked_Union (Base_Type (Operand_Type))
9016 and then not Is_Constrained (Target_Type)
9017 and then not Is_Unchecked_Union (Base_Type (Target_Type))
9018 and then not Has_Inferable_Discriminants (Operand)
9020 -- To prevent Gigi from generating illegal code, we generate a
9021 -- Program_Error node, but we give it the target type of the
9025 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
9026 Reason => PE_Unchecked_Union_Restriction);
9029 Set_Etype (PE, Target_Type);
9034 Handle_Changed_Representation;
9037 -- Case of conversions of enumeration types
9039 elsif Is_Enumeration_Type (Target_Type) then
9041 -- Special processing is required if there is a change of
9042 -- representation (from enumeration representation clauses).
9044 if not Same_Representation (Target_Type, Operand_Type) then
9046 -- Convert: x(y) to x'val (ytyp'val (y))
9049 Make_Attribute_Reference (Loc,
9050 Prefix => New_Occurrence_Of (Target_Type, Loc),
9051 Attribute_Name => Name_Val,
9052 Expressions => New_List (
9053 Make_Attribute_Reference (Loc,
9054 Prefix => New_Occurrence_Of (Operand_Type, Loc),
9055 Attribute_Name => Name_Pos,
9056 Expressions => New_List (Operand)))));
9058 Analyze_And_Resolve (N, Target_Type);
9061 -- Case of conversions to floating-point
9063 elsif Is_Floating_Point_Type (Target_Type) then
9067 -- At this stage, either the conversion node has been transformed into
9068 -- some other equivalent expression, or left as a conversion that can be
9069 -- handled by Gigi, in the following cases:
9071 -- Conversions with no change of representation or type
9073 -- Numeric conversions involving integer, floating- and fixed-point
9074 -- values. Fixed-point values are allowed only if Conversion_OK is
9075 -- set, i.e. if the fixed-point values are to be treated as integers.
9077 -- No other conversions should be passed to Gigi
9079 -- Check: are these rules stated in sinfo??? if so, why restate here???
9081 -- The only remaining step is to generate a range check if we still have
9082 -- a type conversion at this stage and Do_Range_Check is set. For now we
9083 -- do this only for conversions of discrete types.
9085 if Nkind (N) = N_Type_Conversion
9086 and then Is_Discrete_Type (Etype (N))
9089 Expr : constant Node_Id := Expression (N);
9094 if Do_Range_Check (Expr)
9095 and then Is_Discrete_Type (Etype (Expr))
9097 Set_Do_Range_Check (Expr, False);
9099 -- Before we do a range check, we have to deal with treating a
9100 -- fixed-point operand as an integer. The way we do this is
9101 -- simply to do an unchecked conversion to an appropriate
9102 -- integer type large enough to hold the result.
9104 -- This code is not active yet, because we are only dealing
9105 -- with discrete types so far ???
9107 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
9108 and then Treat_Fixed_As_Integer (Expr)
9110 Ftyp := Base_Type (Etype (Expr));
9112 if Esize (Ftyp) >= Esize (Standard_Integer) then
9113 Ityp := Standard_Long_Long_Integer;
9115 Ityp := Standard_Integer;
9118 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
9121 -- Reset overflow flag, since the range check will include
9122 -- dealing with possible overflow, and generate the check. If
9123 -- Address is either a source type or target type, suppress
9124 -- range check to avoid typing anomalies when it is a visible
9127 Set_Do_Overflow_Check (N, False);
9128 if not Is_Descendent_Of_Address (Etype (Expr))
9129 and then not Is_Descendent_Of_Address (Target_Type)
9131 Generate_Range_Check
9132 (Expr, Target_Type, CE_Range_Check_Failed);
9138 -- Final step, if the result is a type conversion involving Vax_Float
9139 -- types, then it is subject for further special processing.
9141 if Nkind (N) = N_Type_Conversion
9142 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
9144 Expand_Vax_Conversion (N);
9148 -- Here at end of processing
9151 -- Apply predicate check if required. Note that we can't just call
9152 -- Apply_Predicate_Check here, because the type looks right after
9153 -- the conversion and it would omit the check. The Comes_From_Source
9154 -- guard is necessary to prevent infinite recursions when we generate
9155 -- internal conversions for the purpose of checking predicates.
9157 if Present (Predicate_Function (Target_Type))
9158 and then Target_Type /= Operand_Type
9159 and then Comes_From_Source (N)
9162 New_Expr : constant Node_Id := Duplicate_Subexpr (N);
9165 -- Avoid infinite recursion on the subsequent expansion of
9166 -- of the copy of the original type conversion.
9168 Set_Comes_From_Source (New_Expr, False);
9169 Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr));
9172 end Expand_N_Type_Conversion;
9174 -----------------------------------
9175 -- Expand_N_Unchecked_Expression --
9176 -----------------------------------
9178 -- Remove the unchecked expression node from the tree. Its job was simply
9179 -- to make sure that its constituent expression was handled with checks
9180 -- off, and now that that is done, we can remove it from the tree, and
9181 -- indeed must, since Gigi does not expect to see these nodes.
9183 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
9184 Exp : constant Node_Id := Expression (N);
9186 Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
9188 end Expand_N_Unchecked_Expression;
9190 ----------------------------------------
9191 -- Expand_N_Unchecked_Type_Conversion --
9192 ----------------------------------------
9194 -- If this cannot be handled by Gigi and we haven't already made a
9195 -- temporary for it, do it now.
9197 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
9198 Target_Type : constant Entity_Id := Etype (N);
9199 Operand : constant Node_Id := Expression (N);
9200 Operand_Type : constant Entity_Id := Etype (Operand);
9203 -- Nothing at all to do if conversion is to the identical type so remove
9204 -- the conversion completely, it is useless, except that it may carry
9205 -- an Assignment_OK indication which must be propagated to the operand.
9207 if Operand_Type = Target_Type then
9209 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
9211 if Assignment_OK (N) then
9212 Set_Assignment_OK (Operand);
9215 Rewrite (N, Relocate_Node (Operand));
9219 -- If we have a conversion of a compile time known value to a target
9220 -- type and the value is in range of the target type, then we can simply
9221 -- replace the construct by an integer literal of the correct type. We
9222 -- only apply this to integer types being converted. Possibly it may
9223 -- apply in other cases, but it is too much trouble to worry about.
9225 -- Note that we do not do this transformation if the Kill_Range_Check
9226 -- flag is set, since then the value may be outside the expected range.
9227 -- This happens in the Normalize_Scalars case.
9229 -- We also skip this if either the target or operand type is biased
9230 -- because in this case, the unchecked conversion is supposed to
9231 -- preserve the bit pattern, not the integer value.
9233 if Is_Integer_Type (Target_Type)
9234 and then not Has_Biased_Representation (Target_Type)
9235 and then Is_Integer_Type (Operand_Type)
9236 and then not Has_Biased_Representation (Operand_Type)
9237 and then Compile_Time_Known_Value (Operand)
9238 and then not Kill_Range_Check (N)
9241 Val : constant Uint := Expr_Value (Operand);
9244 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
9246 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
9248 Val >= Expr_Value (Type_Low_Bound (Target_Type))
9250 Val <= Expr_Value (Type_High_Bound (Target_Type))
9252 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
9254 -- If Address is the target type, just set the type to avoid a
9255 -- spurious type error on the literal when Address is a visible
9258 if Is_Descendent_Of_Address (Target_Type) then
9259 Set_Etype (N, Target_Type);
9261 Analyze_And_Resolve (N, Target_Type);
9269 -- Nothing to do if conversion is safe
9271 if Safe_Unchecked_Type_Conversion (N) then
9275 -- Otherwise force evaluation unless Assignment_OK flag is set (this
9276 -- flag indicates ??? -- more comments needed here)
9278 if Assignment_OK (N) then
9281 Force_Evaluation (N);
9283 end Expand_N_Unchecked_Type_Conversion;
9285 ----------------------------
9286 -- Expand_Record_Equality --
9287 ----------------------------
9289 -- For non-variant records, Equality is expanded when needed into:
9291 -- and then Lhs.Discr1 = Rhs.Discr1
9293 -- and then Lhs.Discrn = Rhs.Discrn
9294 -- and then Lhs.Cmp1 = Rhs.Cmp1
9296 -- and then Lhs.Cmpn = Rhs.Cmpn
9298 -- The expression is folded by the back-end for adjacent fields. This
9299 -- function is called for tagged record in only one occasion: for imple-
9300 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
9301 -- otherwise the primitive "=" is used directly.
9303 function Expand_Record_Equality
9308 Bodies : List_Id) return Node_Id
9310 Loc : constant Source_Ptr := Sloc (Nod);
9315 First_Time : Boolean := True;
9317 function Suitable_Element (C : Entity_Id) return Entity_Id;
9318 -- Return the first field to compare beginning with C, skipping the
9319 -- inherited components.
9321 ----------------------
9322 -- Suitable_Element --
9323 ----------------------
9325 function Suitable_Element (C : Entity_Id) return Entity_Id is
9330 elsif Ekind (C) /= E_Discriminant
9331 and then Ekind (C) /= E_Component
9333 return Suitable_Element (Next_Entity (C));
9335 elsif Is_Tagged_Type (Typ)
9336 and then C /= Original_Record_Component (C)
9338 return Suitable_Element (Next_Entity (C));
9340 elsif Chars (C) = Name_uTag then
9341 return Suitable_Element (Next_Entity (C));
9343 -- The .NET/JVM version of type Root_Controlled contains two fields
9344 -- which should not be considered part of the object. To achieve
9345 -- proper equiality between two controlled objects on .NET/JVM, skip
9346 -- field _parent whenever it is of type Root_Controlled.
9348 elsif Chars (C) = Name_uParent
9349 and then VM_Target /= No_VM
9350 and then Etype (C) = RTE (RE_Root_Controlled)
9352 return Suitable_Element (Next_Entity (C));
9354 elsif Is_Interface (Etype (C)) then
9355 return Suitable_Element (Next_Entity (C));
9360 end Suitable_Element;
9362 -- Start of processing for Expand_Record_Equality
9365 -- Generates the following code: (assuming that Typ has one Discr and
9366 -- component C2 is also a record)
9369 -- and then Lhs.Discr1 = Rhs.Discr1
9370 -- and then Lhs.C1 = Rhs.C1
9371 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
9373 -- and then Lhs.Cmpn = Rhs.Cmpn
9375 Result := New_Reference_To (Standard_True, Loc);
9376 C := Suitable_Element (First_Entity (Typ));
9377 while Present (C) loop
9385 First_Time := False;
9389 New_Lhs := New_Copy_Tree (Lhs);
9390 New_Rhs := New_Copy_Tree (Rhs);
9394 Expand_Composite_Equality (Nod, Etype (C),
9396 Make_Selected_Component (Loc,
9398 Selector_Name => New_Reference_To (C, Loc)),
9400 Make_Selected_Component (Loc,
9402 Selector_Name => New_Reference_To (C, Loc)),
9405 -- If some (sub)component is an unchecked_union, the whole
9406 -- operation will raise program error.
9408 if Nkind (Check) = N_Raise_Program_Error then
9410 Set_Etype (Result, Standard_Boolean);
9415 Left_Opnd => Result,
9416 Right_Opnd => Check);
9420 C := Suitable_Element (Next_Entity (C));
9424 end Expand_Record_Equality;
9426 -----------------------------------
9427 -- Expand_Short_Circuit_Operator --
9428 -----------------------------------
9430 -- Deal with special expansion if actions are present for the right operand
9431 -- and deal with optimizing case of arguments being True or False. We also
9432 -- deal with the special case of non-standard boolean values.
9434 procedure Expand_Short_Circuit_Operator (N : Node_Id) is
9435 Loc : constant Source_Ptr := Sloc (N);
9436 Typ : constant Entity_Id := Etype (N);
9437 Left : constant Node_Id := Left_Opnd (N);
9438 Right : constant Node_Id := Right_Opnd (N);
9439 LocR : constant Source_Ptr := Sloc (Right);
9442 Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
9443 Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
9444 -- If Left = Shortcut_Value then Right need not be evaluated
9446 function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
9447 -- For Opnd a boolean expression, return a Boolean expression equivalent
9448 -- to Opnd /= Shortcut_Value.
9450 --------------------
9451 -- Make_Test_Expr --
9452 --------------------
9454 function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
9456 if Shortcut_Value then
9457 return Make_Op_Not (Sloc (Opnd), Opnd);
9464 -- Entity for a temporary variable holding the value of the operator,
9465 -- used for expansion in the case where actions are present.
9467 -- Start of processing for Expand_Short_Circuit_Operator
9470 -- Deal with non-standard booleans
9472 if Is_Boolean_Type (Typ) then
9473 Adjust_Condition (Left);
9474 Adjust_Condition (Right);
9475 Set_Etype (N, Standard_Boolean);
9478 -- Check for cases where left argument is known to be True or False
9480 if Compile_Time_Known_Value (Left) then
9482 -- Mark SCO for left condition as compile time known
9484 if Generate_SCO and then Comes_From_Source (Left) then
9485 Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
9488 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
9489 -- Any actions associated with Right will be executed unconditionally
9490 -- and can thus be inserted into the tree unconditionally.
9492 if Expr_Value_E (Left) /= Shortcut_Ent then
9493 if Present (Actions (N)) then
9494 Insert_Actions (N, Actions (N));
9499 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
9500 -- In this case we can forget the actions associated with Right,
9501 -- since they will never be executed.
9504 Kill_Dead_Code (Right);
9505 Kill_Dead_Code (Actions (N));
9506 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9509 Adjust_Result_Type (N, Typ);
9513 -- If Actions are present for the right operand, we have to do some
9514 -- special processing. We can't just let these actions filter back into
9515 -- code preceding the short circuit (which is what would have happened
9516 -- if we had not trapped them in the short-circuit form), since they
9517 -- must only be executed if the right operand of the short circuit is
9518 -- executed and not otherwise.
9520 -- the temporary variable C.
9522 if Present (Actions (N)) then
9523 Actlist := Actions (N);
9525 -- The old approach is to expand:
9527 -- left AND THEN right
9531 -- C : Boolean := False;
9539 -- and finally rewrite the operator into a reference to C. Similarly
9540 -- for left OR ELSE right, with negated values. Note that this
9541 -- rewrite causes some difficulties for coverage analysis because
9542 -- of the introduction of the new variable C, which obscures the
9543 -- structure of the test.
9545 -- We use this "old approach" if use of N_Expression_With_Actions
9546 -- is False (see description in Opt of when this is or is not set).
9548 if not Use_Expression_With_Actions then
9549 Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
9552 Make_Object_Declaration (Loc,
9553 Defining_Identifier =>
9555 Object_Definition =>
9556 New_Occurrence_Of (Standard_Boolean, Loc),
9558 New_Occurrence_Of (Shortcut_Ent, Loc)));
9561 Make_Implicit_If_Statement (Right,
9562 Condition => Make_Test_Expr (Right),
9563 Then_Statements => New_List (
9564 Make_Assignment_Statement (LocR,
9565 Name => New_Occurrence_Of (Op_Var, LocR),
9568 (Boolean_Literals (not Shortcut_Value), LocR)))));
9571 Make_Implicit_If_Statement (Left,
9572 Condition => Make_Test_Expr (Left),
9573 Then_Statements => Actlist));
9575 Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
9576 Analyze_And_Resolve (N, Standard_Boolean);
9578 -- The new approach, activated for now by the use of debug flag
9579 -- -gnatd.X is to use the new Expression_With_Actions node for the
9580 -- right operand of the short-circuit form. This should solve the
9581 -- traceability problems for coverage analysis.
9585 Make_Expression_With_Actions (LocR,
9586 Expression => Relocate_Node (Right),
9587 Actions => Actlist));
9588 Set_Actions (N, No_List);
9589 Analyze_And_Resolve (Right, Standard_Boolean);
9592 Adjust_Result_Type (N, Typ);
9596 -- No actions present, check for cases of right argument True/False
9598 if Compile_Time_Known_Value (Right) then
9600 -- Mark SCO for left condition as compile time known
9602 if Generate_SCO and then Comes_From_Source (Right) then
9603 Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
9606 -- Change (Left and then True), (Left or else False) to Left.
9607 -- Note that we know there are no actions associated with the right
9608 -- operand, since we just checked for this case above.
9610 if Expr_Value_E (Right) /= Shortcut_Ent then
9613 -- Change (Left and then False), (Left or else True) to Right,
9614 -- making sure to preserve any side effects associated with the Left
9618 Remove_Side_Effects (Left);
9619 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9623 Adjust_Result_Type (N, Typ);
9624 end Expand_Short_Circuit_Operator;
9626 -------------------------------------
9627 -- Fixup_Universal_Fixed_Operation --
9628 -------------------------------------
9630 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
9631 Conv : constant Node_Id := Parent (N);
9634 -- We must have a type conversion immediately above us
9636 pragma Assert (Nkind (Conv) = N_Type_Conversion);
9638 -- Normally the type conversion gives our target type. The exception
9639 -- occurs in the case of the Round attribute, where the conversion
9640 -- will be to universal real, and our real type comes from the Round
9641 -- attribute (as well as an indication that we must round the result)
9643 if Nkind (Parent (Conv)) = N_Attribute_Reference
9644 and then Attribute_Name (Parent (Conv)) = Name_Round
9646 Set_Etype (N, Etype (Parent (Conv)));
9647 Set_Rounded_Result (N);
9649 -- Normal case where type comes from conversion above us
9652 Set_Etype (N, Etype (Conv));
9654 end Fixup_Universal_Fixed_Operation;
9656 ---------------------------------
9657 -- Has_Inferable_Discriminants --
9658 ---------------------------------
9660 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
9662 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
9663 -- Determines whether the left-most prefix of a selected component is a
9664 -- formal parameter in a subprogram. Assumes N is a selected component.
9666 --------------------------------
9667 -- Prefix_Is_Formal_Parameter --
9668 --------------------------------
9670 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
9671 Sel_Comp : Node_Id := N;
9674 -- Move to the left-most prefix by climbing up the tree
9676 while Present (Parent (Sel_Comp))
9677 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
9679 Sel_Comp := Parent (Sel_Comp);
9682 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
9683 end Prefix_Is_Formal_Parameter;
9685 -- Start of processing for Has_Inferable_Discriminants
9688 -- For identifiers and indexed components, it is sufficient to have a
9689 -- constrained Unchecked_Union nominal subtype.
9691 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
9692 return Is_Unchecked_Union (Base_Type (Etype (N)))
9694 Is_Constrained (Etype (N));
9696 -- For selected components, the subtype of the selector must be a
9697 -- constrained Unchecked_Union. If the component is subject to a
9698 -- per-object constraint, then the enclosing object must have inferable
9701 elsif Nkind (N) = N_Selected_Component then
9702 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
9704 -- A small hack. If we have a per-object constrained selected
9705 -- component of a formal parameter, return True since we do not
9706 -- know the actual parameter association yet.
9708 if Prefix_Is_Formal_Parameter (N) then
9712 -- Otherwise, check the enclosing object and the selector
9714 return Has_Inferable_Discriminants (Prefix (N))
9716 Has_Inferable_Discriminants (Selector_Name (N));
9719 -- The call to Has_Inferable_Discriminants will determine whether
9720 -- the selector has a constrained Unchecked_Union nominal type.
9722 return Has_Inferable_Discriminants (Selector_Name (N));
9724 -- A qualified expression has inferable discriminants if its subtype
9725 -- mark is a constrained Unchecked_Union subtype.
9727 elsif Nkind (N) = N_Qualified_Expression then
9728 return Is_Unchecked_Union (Subtype_Mark (N))
9730 Is_Constrained (Subtype_Mark (N));
9735 end Has_Inferable_Discriminants;
9737 -------------------------------
9738 -- Insert_Dereference_Action --
9739 -------------------------------
9741 procedure Insert_Dereference_Action (N : Node_Id) is
9742 Loc : constant Source_Ptr := Sloc (N);
9743 Typ : constant Entity_Id := Etype (N);
9744 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
9745 Pnod : constant Node_Id := Parent (N);
9747 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
9748 -- Return true if type of P is derived from Checked_Pool;
9750 -----------------------------
9751 -- Is_Checked_Storage_Pool --
9752 -----------------------------
9754 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
9763 while T /= Etype (T) loop
9764 if Is_RTE (T, RE_Checked_Pool) then
9772 end Is_Checked_Storage_Pool;
9774 -- Start of processing for Insert_Dereference_Action
9777 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
9779 if not (Is_Checked_Storage_Pool (Pool)
9780 and then Comes_From_Source (Original_Node (Pnod)))
9786 Make_Procedure_Call_Statement (Loc,
9787 Name => New_Reference_To (
9788 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
9790 Parameter_Associations => New_List (
9794 New_Reference_To (Pool, Loc),
9796 -- Storage_Address. We use the attribute Pool_Address, which uses
9797 -- the pointer itself to find the address of the object, and which
9798 -- handles unconstrained arrays properly by computing the address
9799 -- of the template. i.e. the correct address of the corresponding
9802 Make_Attribute_Reference (Loc,
9803 Prefix => Duplicate_Subexpr_Move_Checks (N),
9804 Attribute_Name => Name_Pool_Address),
9806 -- Size_In_Storage_Elements
9808 Make_Op_Divide (Loc,
9810 Make_Attribute_Reference (Loc,
9812 Make_Explicit_Dereference (Loc,
9813 Duplicate_Subexpr_Move_Checks (N)),
9814 Attribute_Name => Name_Size),
9816 Make_Integer_Literal (Loc, System_Storage_Unit)),
9820 Make_Attribute_Reference (Loc,
9822 Make_Explicit_Dereference (Loc,
9823 Duplicate_Subexpr_Move_Checks (N)),
9824 Attribute_Name => Name_Alignment))));
9827 when RE_Not_Available =>
9829 end Insert_Dereference_Action;
9831 --------------------------------
9832 -- Integer_Promotion_Possible --
9833 --------------------------------
9835 function Integer_Promotion_Possible (N : Node_Id) return Boolean is
9836 Operand : constant Node_Id := Expression (N);
9837 Operand_Type : constant Entity_Id := Etype (Operand);
9838 Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
9841 pragma Assert (Nkind (N) = N_Type_Conversion);
9845 -- We only do the transformation for source constructs. We assume
9846 -- that the expander knows what it is doing when it generates code.
9848 Comes_From_Source (N)
9850 -- If the operand type is Short_Integer or Short_Short_Integer,
9851 -- then we will promote to Integer, which is available on all
9852 -- targets, and is sufficient to ensure no intermediate overflow.
9853 -- Furthermore it is likely to be as efficient or more efficient
9854 -- than using the smaller type for the computation so we do this
9858 (Root_Operand_Type = Base_Type (Standard_Short_Integer)
9860 Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
9862 -- Test for interesting operation, which includes addition,
9863 -- division, exponentiation, multiplication, subtraction, absolute
9864 -- value and unary negation. Unary "+" is omitted since it is a
9865 -- no-op and thus can't overflow.
9867 and then Nkind_In (Operand, N_Op_Abs,
9874 end Integer_Promotion_Possible;
9876 ------------------------------
9877 -- Make_Array_Comparison_Op --
9878 ------------------------------
9880 -- This is a hand-coded expansion of the following generic function:
9883 -- type elem is (<>);
9884 -- type index is (<>);
9885 -- type a is array (index range <>) of elem;
9887 -- function Gnnn (X : a; Y: a) return boolean is
9888 -- J : index := Y'first;
9891 -- if X'length = 0 then
9894 -- elsif Y'length = 0 then
9898 -- for I in X'range loop
9899 -- if X (I) = Y (J) then
9900 -- if J = Y'last then
9903 -- J := index'succ (J);
9907 -- return X (I) > Y (J);
9911 -- return X'length > Y'length;
9915 -- Note that since we are essentially doing this expansion by hand, we
9916 -- do not need to generate an actual or formal generic part, just the
9917 -- instantiated function itself.
9919 function Make_Array_Comparison_Op
9921 Nod : Node_Id) return Node_Id
9923 Loc : constant Source_Ptr := Sloc (Nod);
9925 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
9926 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
9927 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
9928 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
9930 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
9932 Loop_Statement : Node_Id;
9933 Loop_Body : Node_Id;
9936 Final_Expr : Node_Id;
9937 Func_Body : Node_Id;
9938 Func_Name : Entity_Id;
9944 -- if J = Y'last then
9947 -- J := index'succ (J);
9951 Make_Implicit_If_Statement (Nod,
9954 Left_Opnd => New_Reference_To (J, Loc),
9956 Make_Attribute_Reference (Loc,
9957 Prefix => New_Reference_To (Y, Loc),
9958 Attribute_Name => Name_Last)),
9960 Then_Statements => New_List (
9961 Make_Exit_Statement (Loc)),
9965 Make_Assignment_Statement (Loc,
9966 Name => New_Reference_To (J, Loc),
9968 Make_Attribute_Reference (Loc,
9969 Prefix => New_Reference_To (Index, Loc),
9970 Attribute_Name => Name_Succ,
9971 Expressions => New_List (New_Reference_To (J, Loc))))));
9973 -- if X (I) = Y (J) then
9976 -- return X (I) > Y (J);
9980 Make_Implicit_If_Statement (Nod,
9984 Make_Indexed_Component (Loc,
9985 Prefix => New_Reference_To (X, Loc),
9986 Expressions => New_List (New_Reference_To (I, Loc))),
9989 Make_Indexed_Component (Loc,
9990 Prefix => New_Reference_To (Y, Loc),
9991 Expressions => New_List (New_Reference_To (J, Loc)))),
9993 Then_Statements => New_List (Inner_If),
9995 Else_Statements => New_List (
9996 Make_Simple_Return_Statement (Loc,
10000 Make_Indexed_Component (Loc,
10001 Prefix => New_Reference_To (X, Loc),
10002 Expressions => New_List (New_Reference_To (I, Loc))),
10005 Make_Indexed_Component (Loc,
10006 Prefix => New_Reference_To (Y, Loc),
10007 Expressions => New_List (
10008 New_Reference_To (J, Loc)))))));
10010 -- for I in X'range loop
10015 Make_Implicit_Loop_Statement (Nod,
10016 Identifier => Empty,
10018 Iteration_Scheme =>
10019 Make_Iteration_Scheme (Loc,
10020 Loop_Parameter_Specification =>
10021 Make_Loop_Parameter_Specification (Loc,
10022 Defining_Identifier => I,
10023 Discrete_Subtype_Definition =>
10024 Make_Attribute_Reference (Loc,
10025 Prefix => New_Reference_To (X, Loc),
10026 Attribute_Name => Name_Range))),
10028 Statements => New_List (Loop_Body));
10030 -- if X'length = 0 then
10032 -- elsif Y'length = 0 then
10035 -- for ... loop ... end loop;
10036 -- return X'length > Y'length;
10040 Make_Attribute_Reference (Loc,
10041 Prefix => New_Reference_To (X, Loc),
10042 Attribute_Name => Name_Length);
10045 Make_Attribute_Reference (Loc,
10046 Prefix => New_Reference_To (Y, Loc),
10047 Attribute_Name => Name_Length);
10051 Left_Opnd => Length1,
10052 Right_Opnd => Length2);
10055 Make_Implicit_If_Statement (Nod,
10059 Make_Attribute_Reference (Loc,
10060 Prefix => New_Reference_To (X, Loc),
10061 Attribute_Name => Name_Length),
10063 Make_Integer_Literal (Loc, 0)),
10067 Make_Simple_Return_Statement (Loc,
10068 Expression => New_Reference_To (Standard_False, Loc))),
10070 Elsif_Parts => New_List (
10071 Make_Elsif_Part (Loc,
10075 Make_Attribute_Reference (Loc,
10076 Prefix => New_Reference_To (Y, Loc),
10077 Attribute_Name => Name_Length),
10079 Make_Integer_Literal (Loc, 0)),
10083 Make_Simple_Return_Statement (Loc,
10084 Expression => New_Reference_To (Standard_True, Loc))))),
10086 Else_Statements => New_List (
10088 Make_Simple_Return_Statement (Loc,
10089 Expression => Final_Expr)));
10093 Formals := New_List (
10094 Make_Parameter_Specification (Loc,
10095 Defining_Identifier => X,
10096 Parameter_Type => New_Reference_To (Typ, Loc)),
10098 Make_Parameter_Specification (Loc,
10099 Defining_Identifier => Y,
10100 Parameter_Type => New_Reference_To (Typ, Loc)));
10102 -- function Gnnn (...) return boolean is
10103 -- J : index := Y'first;
10108 Func_Name := Make_Temporary (Loc, 'G');
10111 Make_Subprogram_Body (Loc,
10113 Make_Function_Specification (Loc,
10114 Defining_Unit_Name => Func_Name,
10115 Parameter_Specifications => Formals,
10116 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
10118 Declarations => New_List (
10119 Make_Object_Declaration (Loc,
10120 Defining_Identifier => J,
10121 Object_Definition => New_Reference_To (Index, Loc),
10123 Make_Attribute_Reference (Loc,
10124 Prefix => New_Reference_To (Y, Loc),
10125 Attribute_Name => Name_First))),
10127 Handled_Statement_Sequence =>
10128 Make_Handled_Sequence_Of_Statements (Loc,
10129 Statements => New_List (If_Stat)));
10132 end Make_Array_Comparison_Op;
10134 ---------------------------
10135 -- Make_Boolean_Array_Op --
10136 ---------------------------
10138 -- For logical operations on boolean arrays, expand in line the following,
10139 -- replacing 'and' with 'or' or 'xor' where needed:
10141 -- function Annn (A : typ; B: typ) return typ is
10144 -- for J in A'range loop
10145 -- C (J) := A (J) op B (J);
10150 -- Here typ is the boolean array type
10152 function Make_Boolean_Array_Op
10154 N : Node_Id) return Node_Id
10156 Loc : constant Source_Ptr := Sloc (N);
10158 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
10159 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
10160 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
10161 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10169 Func_Name : Entity_Id;
10170 Func_Body : Node_Id;
10171 Loop_Statement : Node_Id;
10175 Make_Indexed_Component (Loc,
10176 Prefix => New_Reference_To (A, Loc),
10177 Expressions => New_List (New_Reference_To (J, Loc)));
10180 Make_Indexed_Component (Loc,
10181 Prefix => New_Reference_To (B, Loc),
10182 Expressions => New_List (New_Reference_To (J, Loc)));
10185 Make_Indexed_Component (Loc,
10186 Prefix => New_Reference_To (C, Loc),
10187 Expressions => New_List (New_Reference_To (J, Loc)));
10189 if Nkind (N) = N_Op_And then
10193 Right_Opnd => B_J);
10195 elsif Nkind (N) = N_Op_Or then
10199 Right_Opnd => B_J);
10205 Right_Opnd => B_J);
10209 Make_Implicit_Loop_Statement (N,
10210 Identifier => Empty,
10212 Iteration_Scheme =>
10213 Make_Iteration_Scheme (Loc,
10214 Loop_Parameter_Specification =>
10215 Make_Loop_Parameter_Specification (Loc,
10216 Defining_Identifier => J,
10217 Discrete_Subtype_Definition =>
10218 Make_Attribute_Reference (Loc,
10219 Prefix => New_Reference_To (A, Loc),
10220 Attribute_Name => Name_Range))),
10222 Statements => New_List (
10223 Make_Assignment_Statement (Loc,
10225 Expression => Op)));
10227 Formals := New_List (
10228 Make_Parameter_Specification (Loc,
10229 Defining_Identifier => A,
10230 Parameter_Type => New_Reference_To (Typ, Loc)),
10232 Make_Parameter_Specification (Loc,
10233 Defining_Identifier => B,
10234 Parameter_Type => New_Reference_To (Typ, Loc)));
10236 Func_Name := Make_Temporary (Loc, 'A');
10237 Set_Is_Inlined (Func_Name);
10240 Make_Subprogram_Body (Loc,
10242 Make_Function_Specification (Loc,
10243 Defining_Unit_Name => Func_Name,
10244 Parameter_Specifications => Formals,
10245 Result_Definition => New_Reference_To (Typ, Loc)),
10247 Declarations => New_List (
10248 Make_Object_Declaration (Loc,
10249 Defining_Identifier => C,
10250 Object_Definition => New_Reference_To (Typ, Loc))),
10252 Handled_Statement_Sequence =>
10253 Make_Handled_Sequence_Of_Statements (Loc,
10254 Statements => New_List (
10256 Make_Simple_Return_Statement (Loc,
10257 Expression => New_Reference_To (C, Loc)))));
10260 end Make_Boolean_Array_Op;
10262 --------------------------------
10263 -- Optimize_Length_Comparison --
10264 --------------------------------
10266 procedure Optimize_Length_Comparison (N : Node_Id) is
10267 Loc : constant Source_Ptr := Sloc (N);
10268 Typ : constant Entity_Id := Etype (N);
10273 -- First and Last attribute reference nodes, which end up as left and
10274 -- right operands of the optimized result.
10277 -- True for comparison operand of zero
10280 -- Comparison operand, set only if Is_Zero is false
10283 -- Entity whose length is being compared
10286 -- Integer_Literal node for length attribute expression, or Empty
10287 -- if there is no such expression present.
10290 -- Type of array index to which 'Length is applied
10292 Op : Node_Kind := Nkind (N);
10293 -- Kind of comparison operator, gets flipped if operands backwards
10295 function Is_Optimizable (N : Node_Id) return Boolean;
10296 -- Tests N to see if it is an optimizable comparison value (defined as
10297 -- constant zero or one, or something else where the value is known to
10298 -- be positive and in the range of 32-bits, and where the corresponding
10299 -- Length value is also known to be 32-bits. If result is true, sets
10300 -- Is_Zero, Ityp, and Comp accordingly.
10302 function Is_Entity_Length (N : Node_Id) return Boolean;
10303 -- Tests if N is a length attribute applied to a simple entity. If so,
10304 -- returns True, and sets Ent to the entity, and Index to the integer
10305 -- literal provided as an attribute expression, or to Empty if none.
10306 -- Also returns True if the expression is a generated type conversion
10307 -- whose expression is of the desired form. This latter case arises
10308 -- when Apply_Universal_Integer_Attribute_Check installs a conversion
10309 -- to check for being in range, which is not needed in this context.
10310 -- Returns False if neither condition holds.
10312 function Prepare_64 (N : Node_Id) return Node_Id;
10313 -- Given a discrete expression, returns a Long_Long_Integer typed
10314 -- expression representing the underlying value of the expression.
10315 -- This is done with an unchecked conversion to the result type. We
10316 -- use unchecked conversion to handle the enumeration type case.
10318 ----------------------
10319 -- Is_Entity_Length --
10320 ----------------------
10322 function Is_Entity_Length (N : Node_Id) return Boolean is
10324 if Nkind (N) = N_Attribute_Reference
10325 and then Attribute_Name (N) = Name_Length
10326 and then Is_Entity_Name (Prefix (N))
10328 Ent := Entity (Prefix (N));
10330 if Present (Expressions (N)) then
10331 Index := First (Expressions (N));
10338 elsif Nkind (N) = N_Type_Conversion
10339 and then not Comes_From_Source (N)
10341 return Is_Entity_Length (Expression (N));
10346 end Is_Entity_Length;
10348 --------------------
10349 -- Is_Optimizable --
10350 --------------------
10352 function Is_Optimizable (N : Node_Id) return Boolean is
10360 if Compile_Time_Known_Value (N) then
10361 Val := Expr_Value (N);
10363 if Val = Uint_0 then
10368 elsif Val = Uint_1 then
10375 -- Here we have to make sure of being within 32-bits
10377 Determine_Range (N, OK, Lo, Hi, Assume_Valid => True);
10380 or else Lo < Uint_1
10381 or else Hi > UI_From_Int (Int'Last)
10386 -- Comparison value was within range, so now we must check the index
10387 -- value to make sure it is also within 32-bits.
10389 Indx := First_Index (Etype (Ent));
10391 if Present (Index) then
10392 for J in 2 .. UI_To_Int (Intval (Index)) loop
10397 Ityp := Etype (Indx);
10399 if Esize (Ityp) > 32 then
10406 end Is_Optimizable;
10412 function Prepare_64 (N : Node_Id) return Node_Id is
10414 return Unchecked_Convert_To (Standard_Long_Long_Integer, N);
10417 -- Start of processing for Optimize_Length_Comparison
10420 -- Nothing to do if not a comparison
10422 if Op not in N_Op_Compare then
10426 -- Nothing to do if special -gnatd.P debug flag set
10428 if Debug_Flag_Dot_PP then
10432 -- Ent'Length op 0/1
10434 if Is_Entity_Length (Left_Opnd (N))
10435 and then Is_Optimizable (Right_Opnd (N))
10439 -- 0/1 op Ent'Length
10441 elsif Is_Entity_Length (Right_Opnd (N))
10442 and then Is_Optimizable (Left_Opnd (N))
10444 -- Flip comparison to opposite sense
10447 when N_Op_Lt => Op := N_Op_Gt;
10448 when N_Op_Le => Op := N_Op_Ge;
10449 when N_Op_Gt => Op := N_Op_Lt;
10450 when N_Op_Ge => Op := N_Op_Le;
10451 when others => null;
10454 -- Else optimization not possible
10460 -- Fall through if we will do the optimization
10462 -- Cases to handle:
10464 -- X'Length = 0 => X'First > X'Last
10465 -- X'Length = 1 => X'First = X'Last
10466 -- X'Length = n => X'First + (n - 1) = X'Last
10468 -- X'Length /= 0 => X'First <= X'Last
10469 -- X'Length /= 1 => X'First /= X'Last
10470 -- X'Length /= n => X'First + (n - 1) /= X'Last
10472 -- X'Length >= 0 => always true, warn
10473 -- X'Length >= 1 => X'First <= X'Last
10474 -- X'Length >= n => X'First + (n - 1) <= X'Last
10476 -- X'Length > 0 => X'First <= X'Last
10477 -- X'Length > 1 => X'First < X'Last
10478 -- X'Length > n => X'First + (n - 1) < X'Last
10480 -- X'Length <= 0 => X'First > X'Last (warn, could be =)
10481 -- X'Length <= 1 => X'First >= X'Last
10482 -- X'Length <= n => X'First + (n - 1) >= X'Last
10484 -- X'Length < 0 => always false (warn)
10485 -- X'Length < 1 => X'First > X'Last
10486 -- X'Length < n => X'First + (n - 1) > X'Last
10488 -- Note: for the cases of n (not constant 0,1), we require that the
10489 -- corresponding index type be integer or shorter (i.e. not 64-bit),
10490 -- and the same for the comparison value. Then we do the comparison
10491 -- using 64-bit arithmetic (actually long long integer), so that we
10492 -- cannot have overflow intefering with the result.
10494 -- First deal with warning cases
10503 Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc)));
10504 Analyze_And_Resolve (N, Typ);
10505 Warn_On_Known_Condition (N);
10512 Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc)));
10513 Analyze_And_Resolve (N, Typ);
10514 Warn_On_Known_Condition (N);
10518 if Constant_Condition_Warnings
10519 and then Comes_From_Source (Original_Node (N))
10521 Error_Msg_N ("could replace by ""'=""?", N);
10531 -- Build the First reference we will use
10534 Make_Attribute_Reference (Loc,
10535 Prefix => New_Occurrence_Of (Ent, Loc),
10536 Attribute_Name => Name_First);
10538 if Present (Index) then
10539 Set_Expressions (Left, New_List (New_Copy (Index)));
10542 -- If general value case, then do the addition of (n - 1), and
10543 -- also add the needed conversions to type Long_Long_Integer.
10545 if Present (Comp) then
10548 Left_Opnd => Prepare_64 (Left),
10550 Make_Op_Subtract (Loc,
10551 Left_Opnd => Prepare_64 (Comp),
10552 Right_Opnd => Make_Integer_Literal (Loc, 1)));
10555 -- Build the Last reference we will use
10558 Make_Attribute_Reference (Loc,
10559 Prefix => New_Occurrence_Of (Ent, Loc),
10560 Attribute_Name => Name_Last);
10562 if Present (Index) then
10563 Set_Expressions (Right, New_List (New_Copy (Index)));
10566 -- If general operand, convert Last reference to Long_Long_Integer
10568 if Present (Comp) then
10569 Right := Prepare_64 (Right);
10572 -- Check for cases to optimize
10574 -- X'Length = 0 => X'First > X'Last
10575 -- X'Length < 1 => X'First > X'Last
10576 -- X'Length < n => X'First + (n - 1) > X'Last
10578 if (Is_Zero and then Op = N_Op_Eq)
10579 or else (not Is_Zero and then Op = N_Op_Lt)
10584 Right_Opnd => Right);
10586 -- X'Length = 1 => X'First = X'Last
10587 -- X'Length = n => X'First + (n - 1) = X'Last
10589 elsif not Is_Zero and then Op = N_Op_Eq then
10593 Right_Opnd => Right);
10595 -- X'Length /= 0 => X'First <= X'Last
10596 -- X'Length > 0 => X'First <= X'Last
10598 elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then
10602 Right_Opnd => Right);
10604 -- X'Length /= 1 => X'First /= X'Last
10605 -- X'Length /= n => X'First + (n - 1) /= X'Last
10607 elsif not Is_Zero and then Op = N_Op_Ne then
10611 Right_Opnd => Right);
10613 -- X'Length >= 1 => X'First <= X'Last
10614 -- X'Length >= n => X'First + (n - 1) <= X'Last
10616 elsif not Is_Zero and then Op = N_Op_Ge then
10620 Right_Opnd => Right);
10622 -- X'Length > 1 => X'First < X'Last
10623 -- X'Length > n => X'First + (n = 1) < X'Last
10625 elsif not Is_Zero and then Op = N_Op_Gt then
10629 Right_Opnd => Right);
10631 -- X'Length <= 1 => X'First >= X'Last
10632 -- X'Length <= n => X'First + (n - 1) >= X'Last
10634 elsif not Is_Zero and then Op = N_Op_Le then
10638 Right_Opnd => Right);
10640 -- Should not happen at this stage
10643 raise Program_Error;
10646 -- Rewrite and finish up
10648 Rewrite (N, Result);
10649 Analyze_And_Resolve (N, Typ);
10651 end Optimize_Length_Comparison;
10653 ------------------------
10654 -- Rewrite_Comparison --
10655 ------------------------
10657 procedure Rewrite_Comparison (N : Node_Id) is
10658 Warning_Generated : Boolean := False;
10659 -- Set to True if first pass with Assume_Valid generates a warning in
10660 -- which case we skip the second pass to avoid warning overloaded.
10663 -- Set to Standard_True or Standard_False
10666 if Nkind (N) = N_Type_Conversion then
10667 Rewrite_Comparison (Expression (N));
10670 elsif Nkind (N) not in N_Op_Compare then
10674 -- Now start looking at the comparison in detail. We potentially go
10675 -- through this loop twice. The first time, Assume_Valid is set False
10676 -- in the call to Compile_Time_Compare. If this call results in a
10677 -- clear result of always True or Always False, that's decisive and
10678 -- we are done. Otherwise we repeat the processing with Assume_Valid
10679 -- set to True to generate additional warnings. We can skip that step
10680 -- if Constant_Condition_Warnings is False.
10682 for AV in False .. True loop
10684 Typ : constant Entity_Id := Etype (N);
10685 Op1 : constant Node_Id := Left_Opnd (N);
10686 Op2 : constant Node_Id := Right_Opnd (N);
10688 Res : constant Compare_Result :=
10689 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
10690 -- Res indicates if compare outcome can be compile time determined
10692 True_Result : Boolean;
10693 False_Result : Boolean;
10696 case N_Op_Compare (Nkind (N)) is
10698 True_Result := Res = EQ;
10699 False_Result := Res = LT or else Res = GT or else Res = NE;
10702 True_Result := Res in Compare_GE;
10703 False_Result := Res = LT;
10706 and then Constant_Condition_Warnings
10707 and then Comes_From_Source (Original_Node (N))
10708 and then Nkind (Original_Node (N)) = N_Op_Ge
10709 and then not In_Instance
10710 and then Is_Integer_Type (Etype (Left_Opnd (N)))
10711 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
10714 ("can never be greater than, could replace by ""'=""?", N);
10715 Warning_Generated := True;
10719 True_Result := Res = GT;
10720 False_Result := Res in Compare_LE;
10723 True_Result := Res = LT;
10724 False_Result := Res in Compare_GE;
10727 True_Result := Res in Compare_LE;
10728 False_Result := Res = GT;
10731 and then Constant_Condition_Warnings
10732 and then Comes_From_Source (Original_Node (N))
10733 and then Nkind (Original_Node (N)) = N_Op_Le
10734 and then not In_Instance
10735 and then Is_Integer_Type (Etype (Left_Opnd (N)))
10736 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
10739 ("can never be less than, could replace by ""'=""?", N);
10740 Warning_Generated := True;
10744 True_Result := Res = NE or else Res = GT or else Res = LT;
10745 False_Result := Res = EQ;
10748 -- If this is the first iteration, then we actually convert the
10749 -- comparison into True or False, if the result is certain.
10752 if True_Result or False_Result then
10753 if True_Result then
10754 Result := Standard_True;
10756 Result := Standard_False;
10761 New_Occurrence_Of (Result, Sloc (N))));
10762 Analyze_And_Resolve (N, Typ);
10763 Warn_On_Known_Condition (N);
10767 -- If this is the second iteration (AV = True), and the original
10768 -- node comes from source and we are not in an instance, then give
10769 -- a warning if we know result would be True or False. Note: we
10770 -- know Constant_Condition_Warnings is set if we get here.
10772 elsif Comes_From_Source (Original_Node (N))
10773 and then not In_Instance
10775 if True_Result then
10777 ("condition can only be False if invalid values present?",
10779 elsif False_Result then
10781 ("condition can only be True if invalid values present?",
10787 -- Skip second iteration if not warning on constant conditions or
10788 -- if the first iteration already generated a warning of some kind or
10789 -- if we are in any case assuming all values are valid (so that the
10790 -- first iteration took care of the valid case).
10792 exit when not Constant_Condition_Warnings;
10793 exit when Warning_Generated;
10794 exit when Assume_No_Invalid_Values;
10796 end Rewrite_Comparison;
10798 ----------------------------
10799 -- Safe_In_Place_Array_Op --
10800 ----------------------------
10802 function Safe_In_Place_Array_Op
10805 Op2 : Node_Id) return Boolean
10807 Target : Entity_Id;
10809 function Is_Safe_Operand (Op : Node_Id) return Boolean;
10810 -- Operand is safe if it cannot overlap part of the target of the
10811 -- operation. If the operand and the target are identical, the operand
10812 -- is safe. The operand can be empty in the case of negation.
10814 function Is_Unaliased (N : Node_Id) return Boolean;
10815 -- Check that N is a stand-alone entity
10821 function Is_Unaliased (N : Node_Id) return Boolean is
10825 and then No (Address_Clause (Entity (N)))
10826 and then No (Renamed_Object (Entity (N)));
10829 ---------------------
10830 -- Is_Safe_Operand --
10831 ---------------------
10833 function Is_Safe_Operand (Op : Node_Id) return Boolean is
10838 elsif Is_Entity_Name (Op) then
10839 return Is_Unaliased (Op);
10841 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
10842 return Is_Unaliased (Prefix (Op));
10844 elsif Nkind (Op) = N_Slice then
10846 Is_Unaliased (Prefix (Op))
10847 and then Entity (Prefix (Op)) /= Target;
10849 elsif Nkind (Op) = N_Op_Not then
10850 return Is_Safe_Operand (Right_Opnd (Op));
10855 end Is_Safe_Operand;
10857 -- Start of processing for Is_Safe_In_Place_Array_Op
10860 -- Skip this processing if the component size is different from system
10861 -- storage unit (since at least for NOT this would cause problems).
10863 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
10866 -- Cannot do in place stuff on VM_Target since cannot pass addresses
10868 elsif VM_Target /= No_VM then
10871 -- Cannot do in place stuff if non-standard Boolean representation
10873 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
10876 elsif not Is_Unaliased (Lhs) then
10880 Target := Entity (Lhs);
10881 return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
10883 end Safe_In_Place_Array_Op;
10885 -----------------------
10886 -- Tagged_Membership --
10887 -----------------------
10889 -- There are two different cases to consider depending on whether the right
10890 -- operand is a class-wide type or not. If not we just compare the actual
10891 -- tag of the left expr to the target type tag:
10893 -- Left_Expr.Tag = Right_Type'Tag;
10895 -- If it is a class-wide type we use the RT function CW_Membership which is
10896 -- usually implemented by looking in the ancestor tables contained in the
10897 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
10899 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
10900 -- function IW_Membership which is usually implemented by looking in the
10901 -- table of abstract interface types plus the ancestor table contained in
10902 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
10904 procedure Tagged_Membership
10906 SCIL_Node : out Node_Id;
10907 Result : out Node_Id)
10909 Left : constant Node_Id := Left_Opnd (N);
10910 Right : constant Node_Id := Right_Opnd (N);
10911 Loc : constant Source_Ptr := Sloc (N);
10913 Full_R_Typ : Entity_Id;
10914 Left_Type : Entity_Id;
10915 New_Node : Node_Id;
10916 Right_Type : Entity_Id;
10920 SCIL_Node := Empty;
10922 -- Handle entities from the limited view
10924 Left_Type := Available_View (Etype (Left));
10925 Right_Type := Available_View (Etype (Right));
10927 if Is_Class_Wide_Type (Left_Type) then
10928 Left_Type := Root_Type (Left_Type);
10931 if Is_Class_Wide_Type (Right_Type) then
10932 Full_R_Typ := Underlying_Type (Root_Type (Right_Type));
10934 Full_R_Typ := Underlying_Type (Right_Type);
10938 Make_Selected_Component (Loc,
10939 Prefix => Relocate_Node (Left),
10941 New_Reference_To (First_Tag_Component (Left_Type), Loc));
10943 if Is_Class_Wide_Type (Right_Type) then
10945 -- No need to issue a run-time check if we statically know that the
10946 -- result of this membership test is always true. For example,
10947 -- considering the following declarations:
10949 -- type Iface is interface;
10950 -- type T is tagged null record;
10951 -- type DT is new T and Iface with null record;
10956 -- These membership tests are always true:
10959 -- Obj2 in T'Class;
10960 -- Obj2 in Iface'Class;
10962 -- We do not need to handle cases where the membership is illegal.
10965 -- Obj1 in DT'Class; -- Compile time error
10966 -- Obj1 in Iface'Class; -- Compile time error
10968 if not Is_Class_Wide_Type (Left_Type)
10969 and then (Is_Ancestor (Etype (Right_Type), Left_Type,
10970 Use_Full_View => True)
10971 or else (Is_Interface (Etype (Right_Type))
10972 and then Interface_Present_In_Ancestor
10974 Iface => Etype (Right_Type))))
10976 Result := New_Reference_To (Standard_True, Loc);
10980 -- Ada 2005 (AI-251): Class-wide applied to interfaces
10982 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
10984 -- Support to: "Iface_CW_Typ in Typ'Class"
10986 or else Is_Interface (Left_Type)
10988 -- Issue error if IW_Membership operation not available in a
10989 -- configurable run time setting.
10991 if not RTE_Available (RE_IW_Membership) then
10993 ("dynamic membership test on interface types", N);
10999 Make_Function_Call (Loc,
11000 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
11001 Parameter_Associations => New_List (
11002 Make_Attribute_Reference (Loc,
11004 Attribute_Name => Name_Address),
11006 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))),
11009 -- Ada 95: Normal case
11012 Build_CW_Membership (Loc,
11013 Obj_Tag_Node => Obj_Tag,
11016 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc),
11018 New_Node => New_Node);
11020 -- Generate the SCIL node for this class-wide membership test.
11021 -- Done here because the previous call to Build_CW_Membership
11022 -- relocates Obj_Tag.
11024 if Generate_SCIL then
11025 SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
11026 Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
11027 Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
11030 Result := New_Node;
11033 -- Right_Type is not a class-wide type
11036 -- No need to check the tag of the object if Right_Typ is abstract
11038 if Is_Abstract_Type (Right_Type) then
11039 Result := New_Reference_To (Standard_False, Loc);
11044 Left_Opnd => Obj_Tag,
11047 (Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc));
11050 end Tagged_Membership;
11052 ------------------------------
11053 -- Unary_Op_Validity_Checks --
11054 ------------------------------
11056 procedure Unary_Op_Validity_Checks (N : Node_Id) is
11058 if Validity_Checks_On and Validity_Check_Operands then
11059 Ensure_Valid (Right_Opnd (N));
11061 end Unary_Op_Validity_Checks;
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