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_Ch2; use Exp_Ch2;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Ch6; use Exp_Ch6;
37 with Exp_Ch7; use Exp_Ch7;
38 with Exp_Ch9; use Exp_Ch9;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Fixd; use Exp_Fixd;
41 with Exp_Intr; use Exp_Intr;
42 with Exp_Pakd; use Exp_Pakd;
43 with Exp_Tss; use Exp_Tss;
44 with Exp_Util; use Exp_Util;
45 with Exp_VFpt; use Exp_VFpt;
46 with Freeze; use Freeze;
47 with Inline; use Inline;
49 with Namet; use Namet;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Par_SCO; use Par_SCO;
54 with Restrict; use Restrict;
55 with Rident; use Rident;
56 with Rtsfind; use Rtsfind;
58 with Sem_Aux; use Sem_Aux;
59 with Sem_Cat; use Sem_Cat;
60 with Sem_Ch3; use Sem_Ch3;
61 with Sem_Ch8; use Sem_Ch8;
62 with Sem_Ch13; use Sem_Ch13;
63 with Sem_Eval; use Sem_Eval;
64 with Sem_Res; use Sem_Res;
65 with Sem_Type; use Sem_Type;
66 with Sem_Util; use Sem_Util;
67 with Sem_Warn; use Sem_Warn;
68 with Sinfo; use Sinfo;
69 with Snames; use Snames;
70 with Stand; use Stand;
71 with SCIL_LL; use SCIL_LL;
72 with Targparm; use Targparm;
73 with Tbuild; use Tbuild;
74 with Ttypes; use Ttypes;
75 with Uintp; use Uintp;
76 with Urealp; use Urealp;
77 with Validsw; use Validsw;
79 package body Exp_Ch4 is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 procedure Binary_Op_Validity_Checks (N : Node_Id);
86 pragma Inline (Binary_Op_Validity_Checks);
87 -- Performs validity checks for a binary operator
89 procedure Build_Boolean_Array_Proc_Call
93 -- If a boolean array assignment can be done in place, build call to
94 -- corresponding library procedure.
96 function Current_Anonymous_Master return Entity_Id;
97 -- Return the entity of the heterogeneous finalization master belonging to
98 -- the current unit (either function, package or procedure). This master
99 -- services all anonymous access-to-controlled types. If the current unit
100 -- does not have such master, create one.
102 procedure Displace_Allocator_Pointer (N : Node_Id);
103 -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
104 -- Expand_Allocator_Expression. Allocating class-wide interface objects
105 -- this routine displaces the pointer to the allocated object to reference
106 -- the component referencing the corresponding secondary dispatch table.
108 procedure Expand_Allocator_Expression (N : Node_Id);
109 -- Subsidiary to Expand_N_Allocator, for the case when the expression
110 -- is a qualified expression or an aggregate.
112 procedure Expand_Array_Comparison (N : Node_Id);
113 -- This routine handles expansion of the comparison operators (N_Op_Lt,
114 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
115 -- code for these operators is similar, differing only in the details of
116 -- the actual comparison call that is made. Special processing (call a
119 function Expand_Array_Equality
124 Typ : Entity_Id) return Node_Id;
125 -- Expand an array equality into a call to a function implementing this
126 -- equality, and a call to it. Loc is the location for the generated nodes.
127 -- Lhs and Rhs are the array expressions to be compared. Bodies is a list
128 -- on which to attach bodies of local functions that are created in the
129 -- process. It is the responsibility of the caller to insert those bodies
130 -- at the right place. Nod provides the Sloc value for the generated code.
131 -- Normally the types used for the generated equality routine are taken
132 -- from Lhs and Rhs. However, in some situations of generated code, the
133 -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
134 -- the type to be used for the formal parameters.
136 procedure Expand_Boolean_Operator (N : Node_Id);
137 -- Common expansion processing for Boolean operators (And, Or, Xor) for the
138 -- case of array type arguments.
140 procedure Expand_Short_Circuit_Operator (N : Node_Id);
141 -- Common expansion processing for short-circuit boolean operators
143 function Expand_Composite_Equality
148 Bodies : List_Id) return Node_Id;
149 -- Local recursive function used to expand equality for nested composite
150 -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
151 -- to attach bodies of local functions that are created in the process.
152 -- This is the responsibility of the caller to insert those bodies at the
153 -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs
154 -- are the left and right sides for the comparison, and Typ is the type of
155 -- the arrays to compare.
157 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id);
158 -- Routine to expand concatenation of a sequence of two or more operands
159 -- (in the list Operands) and replace node Cnode with the result of the
160 -- concatenation. The operands can be of any appropriate type, and can
161 -- include both arrays and singleton elements.
163 procedure Fixup_Universal_Fixed_Operation (N : Node_Id);
164 -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
165 -- fixed. We do not have such a type at runtime, so the purpose of this
166 -- routine is to find the real type by looking up the tree. We also
167 -- determine if the operation must be rounded.
169 function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
170 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
171 -- discriminants if it has a constrained nominal type, unless the object
172 -- is a component of an enclosing Unchecked_Union object that is subject
173 -- to a per-object constraint and the enclosing object lacks inferable
176 -- An expression of an Unchecked_Union type has inferable discriminants
177 -- if it is either a name of an object with inferable discriminants or a
178 -- qualified expression whose subtype mark denotes a constrained subtype.
180 procedure Insert_Dereference_Action (N : Node_Id);
181 -- N is an expression whose type is an access. When the type of the
182 -- associated storage pool is derived from Checked_Pool, generate a
183 -- call to the 'Dereference' primitive operation.
185 function Make_Array_Comparison_Op
187 Nod : Node_Id) return Node_Id;
188 -- Comparisons between arrays are expanded in line. This function produces
189 -- the body of the implementation of (a > b), where a and b are one-
190 -- dimensional arrays of some discrete type. The original node is then
191 -- expanded into the appropriate call to this function. Nod provides the
192 -- Sloc value for the generated code.
194 function Make_Boolean_Array_Op
196 N : Node_Id) return Node_Id;
197 -- Boolean operations on boolean arrays are expanded in line. This function
198 -- produce the body for the node N, which is (a and b), (a or b), or (a xor
199 -- b). It is used only the normal case and not the packed case. The type
200 -- involved, Typ, is the Boolean array type, and the logical operations in
201 -- the body are simple boolean operations. Note that Typ is always a
202 -- constrained type (the caller has ensured this by using
203 -- Convert_To_Actual_Subtype if necessary).
205 procedure Optimize_Length_Comparison (N : Node_Id);
206 -- Given an expression, if it is of the form X'Length op N (or the other
207 -- way round), where N is known at compile time to be 0 or 1, and X is a
208 -- simple entity, and op is a comparison operator, optimizes it into a
209 -- comparison of First and Last.
211 procedure Rewrite_Comparison (N : Node_Id);
212 -- If N is the node for a comparison whose outcome can be determined at
213 -- compile time, then the node N can be rewritten with True or False. If
214 -- the outcome cannot be determined at compile time, the call has no
215 -- effect. If N is a type conversion, then this processing is applied to
216 -- its expression. If N is neither comparison nor a type conversion, the
217 -- call has no effect.
219 procedure Tagged_Membership
221 SCIL_Node : out Node_Id;
222 Result : out Node_Id);
223 -- Construct the expression corresponding to the tagged membership test.
224 -- Deals with a second operand being (or not) a class-wide type.
226 function Safe_In_Place_Array_Op
229 Op2 : Node_Id) return Boolean;
230 -- In the context of an assignment, where the right-hand side is a boolean
231 -- operation on arrays, check whether operation can be performed in place.
233 procedure Unary_Op_Validity_Checks (N : Node_Id);
234 pragma Inline (Unary_Op_Validity_Checks);
235 -- Performs validity checks for a unary operator
237 -------------------------------
238 -- Binary_Op_Validity_Checks --
239 -------------------------------
241 procedure Binary_Op_Validity_Checks (N : Node_Id) is
243 if Validity_Checks_On and Validity_Check_Operands then
244 Ensure_Valid (Left_Opnd (N));
245 Ensure_Valid (Right_Opnd (N));
247 end Binary_Op_Validity_Checks;
249 ------------------------------------
250 -- Build_Boolean_Array_Proc_Call --
251 ------------------------------------
253 procedure Build_Boolean_Array_Proc_Call
258 Loc : constant Source_Ptr := Sloc (N);
259 Kind : constant Node_Kind := Nkind (Expression (N));
260 Target : constant Node_Id :=
261 Make_Attribute_Reference (Loc,
263 Attribute_Name => Name_Address);
265 Arg1 : Node_Id := Op1;
266 Arg2 : Node_Id := Op2;
268 Proc_Name : Entity_Id;
271 if Kind = N_Op_Not then
272 if Nkind (Op1) in N_Binary_Op then
274 -- Use negated version of the binary operators
276 if Nkind (Op1) = N_Op_And then
277 Proc_Name := RTE (RE_Vector_Nand);
279 elsif Nkind (Op1) = N_Op_Or then
280 Proc_Name := RTE (RE_Vector_Nor);
282 else pragma Assert (Nkind (Op1) = N_Op_Xor);
283 Proc_Name := RTE (RE_Vector_Xor);
287 Make_Procedure_Call_Statement (Loc,
288 Name => New_Occurrence_Of (Proc_Name, Loc),
290 Parameter_Associations => New_List (
292 Make_Attribute_Reference (Loc,
293 Prefix => Left_Opnd (Op1),
294 Attribute_Name => Name_Address),
296 Make_Attribute_Reference (Loc,
297 Prefix => Right_Opnd (Op1),
298 Attribute_Name => Name_Address),
300 Make_Attribute_Reference (Loc,
301 Prefix => Left_Opnd (Op1),
302 Attribute_Name => Name_Length)));
305 Proc_Name := RTE (RE_Vector_Not);
308 Make_Procedure_Call_Statement (Loc,
309 Name => New_Occurrence_Of (Proc_Name, Loc),
310 Parameter_Associations => New_List (
313 Make_Attribute_Reference (Loc,
315 Attribute_Name => Name_Address),
317 Make_Attribute_Reference (Loc,
319 Attribute_Name => Name_Length)));
323 -- We use the following equivalences:
325 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
326 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
327 -- (not X) xor (not Y) = X xor Y
328 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
330 if Nkind (Op1) = N_Op_Not then
331 Arg1 := Right_Opnd (Op1);
332 Arg2 := Right_Opnd (Op2);
333 if Kind = N_Op_And then
334 Proc_Name := RTE (RE_Vector_Nor);
335 elsif Kind = N_Op_Or then
336 Proc_Name := RTE (RE_Vector_Nand);
338 Proc_Name := RTE (RE_Vector_Xor);
342 if Kind = N_Op_And then
343 Proc_Name := RTE (RE_Vector_And);
344 elsif Kind = N_Op_Or then
345 Proc_Name := RTE (RE_Vector_Or);
346 elsif Nkind (Op2) = N_Op_Not then
347 Proc_Name := RTE (RE_Vector_Nxor);
348 Arg2 := Right_Opnd (Op2);
350 Proc_Name := RTE (RE_Vector_Xor);
355 Make_Procedure_Call_Statement (Loc,
356 Name => New_Occurrence_Of (Proc_Name, Loc),
357 Parameter_Associations => New_List (
359 Make_Attribute_Reference (Loc,
361 Attribute_Name => Name_Address),
362 Make_Attribute_Reference (Loc,
364 Attribute_Name => Name_Address),
365 Make_Attribute_Reference (Loc,
367 Attribute_Name => Name_Length)));
370 Rewrite (N, Call_Node);
374 when RE_Not_Available =>
376 end Build_Boolean_Array_Proc_Call;
378 ------------------------------
379 -- Current_Anonymous_Master --
380 ------------------------------
382 function Current_Anonymous_Master return Entity_Id is
390 Unit_Id := Cunit_Entity (Current_Sem_Unit);
392 -- Find the entity of the current unit
394 if Ekind (Unit_Id) = E_Subprogram_Body then
396 -- When processing subprogram bodies, the proper scope is always that
399 Subp_Body := Unit_Id;
400 while Present (Subp_Body)
401 and then Nkind (Subp_Body) /= N_Subprogram_Body
403 Subp_Body := Parent (Subp_Body);
406 Unit_Id := Corresponding_Spec (Subp_Body);
409 Loc := Sloc (Unit_Id);
410 Unit_Decl := Unit (Cunit (Current_Sem_Unit));
412 -- Find the declarations list of the current unit
414 if Nkind (Unit_Decl) = N_Package_Declaration then
415 Unit_Decl := Specification (Unit_Decl);
416 Decls := Visible_Declarations (Unit_Decl);
419 Decls := New_List (Make_Null_Statement (Loc));
420 Set_Visible_Declarations (Unit_Decl, Decls);
422 elsif Is_Empty_List (Decls) then
423 Append_To (Decls, Make_Null_Statement (Loc));
427 Decls := Declarations (Unit_Decl);
430 Decls := New_List (Make_Null_Statement (Loc));
431 Set_Declarations (Unit_Decl, Decls);
433 elsif Is_Empty_List (Decls) then
434 Append_To (Decls, Make_Null_Statement (Loc));
438 -- The current unit has an existing anonymous master, traverse its
439 -- declarations and locate the entity.
441 if Has_Anonymous_Master (Unit_Id) then
444 Fin_Mas_Id : Entity_Id;
447 Decl := First (Decls);
448 while Present (Decl) loop
450 -- Look for the first variable in the declarations whole type
451 -- is Finalization_Master.
453 if Nkind (Decl) = N_Object_Declaration then
454 Fin_Mas_Id := Defining_Identifier (Decl);
456 if Ekind (Fin_Mas_Id) = E_Variable
457 and then Etype (Fin_Mas_Id) = RTE (RE_Finalization_Master)
466 -- The master was not found even though the unit was labeled as
472 -- Create a new anonymous master
476 First_Decl : constant Node_Id := First (Decls);
478 Fin_Mas_Id : Entity_Id;
481 -- Since the master and its associated initialization is inserted
482 -- at top level, use the scope of the unit when analyzing.
484 Push_Scope (Unit_Id);
486 -- Create the finalization master
489 Make_Defining_Identifier (Loc,
490 Chars => New_External_Name (Chars (Unit_Id), "AM"));
493 -- <Fin_Mas_Id> : Finalization_Master;
496 Make_Object_Declaration (Loc,
497 Defining_Identifier => Fin_Mas_Id,
499 New_Reference_To (RTE (RE_Finalization_Master), Loc));
501 Insert_Before_And_Analyze (First_Decl, Action);
503 -- Mark the unit to prevent the generation of multiple masters
505 Set_Has_Anonymous_Master (Unit_Id);
507 -- Do not set the base pool and mode of operation on .NET/JVM
508 -- since those targets do not support pools and all VM masters
509 -- are heterogeneous by default.
511 if VM_Target = No_VM then
515 -- (<Fin_Mas_Id>, Global_Pool_Object'Unrestricted_Access);
518 Make_Procedure_Call_Statement (Loc,
520 New_Reference_To (RTE (RE_Set_Base_Pool), Loc),
522 Parameter_Associations => New_List (
523 New_Reference_To (Fin_Mas_Id, Loc),
524 Make_Attribute_Reference (Loc,
526 New_Reference_To (RTE (RE_Global_Pool_Object), Loc),
527 Attribute_Name => Name_Unrestricted_Access)));
529 Insert_Before_And_Analyze (First_Decl, Action);
532 -- Set_Is_Heterogeneous (<Fin_Mas_Id>);
535 Make_Procedure_Call_Statement (Loc,
537 New_Reference_To (RTE (RE_Set_Is_Heterogeneous), Loc),
538 Parameter_Associations => New_List (
539 New_Reference_To (Fin_Mas_Id, Loc)));
541 Insert_Before_And_Analyze (First_Decl, Action);
544 -- Restore the original state of the scope stack
551 end Current_Anonymous_Master;
553 --------------------------------
554 -- Displace_Allocator_Pointer --
555 --------------------------------
557 procedure Displace_Allocator_Pointer (N : Node_Id) is
558 Loc : constant Source_Ptr := Sloc (N);
559 Orig_Node : constant Node_Id := Original_Node (N);
565 -- Do nothing in case of VM targets: the virtual machine will handle
566 -- interfaces directly.
568 if not Tagged_Type_Expansion then
572 pragma Assert (Nkind (N) = N_Identifier
573 and then Nkind (Orig_Node) = N_Allocator);
575 PtrT := Etype (Orig_Node);
576 Dtyp := Available_View (Designated_Type (PtrT));
577 Etyp := Etype (Expression (Orig_Node));
579 if Is_Class_Wide_Type (Dtyp)
580 and then Is_Interface (Dtyp)
582 -- If the type of the allocator expression is not an interface type
583 -- we can generate code to reference the record component containing
584 -- the pointer to the secondary dispatch table.
586 if not Is_Interface (Etyp) then
588 Saved_Typ : constant Entity_Id := Etype (Orig_Node);
591 -- 1) Get access to the allocated object
594 Make_Explicit_Dereference (Loc,
599 -- 2) Add the conversion to displace the pointer to reference
600 -- the secondary dispatch table.
602 Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
603 Analyze_And_Resolve (N, Dtyp);
605 -- 3) The 'access to the secondary dispatch table will be used
606 -- as the value returned by the allocator.
609 Make_Attribute_Reference (Loc,
610 Prefix => Relocate_Node (N),
611 Attribute_Name => Name_Access));
612 Set_Etype (N, Saved_Typ);
616 -- If the type of the allocator expression is an interface type we
617 -- generate a run-time call to displace "this" to reference the
618 -- component containing the pointer to the secondary dispatch table
619 -- or else raise Constraint_Error if the actual object does not
620 -- implement the target interface. This case corresponds with the
621 -- following example:
623 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
625 -- return new Iface_2'Class'(Obj);
630 Unchecked_Convert_To (PtrT,
631 Make_Function_Call (Loc,
632 Name => New_Reference_To (RTE (RE_Displace), Loc),
633 Parameter_Associations => New_List (
634 Unchecked_Convert_To (RTE (RE_Address),
640 (Access_Disp_Table (Etype (Base_Type (Dtyp))))),
642 Analyze_And_Resolve (N, PtrT);
645 end Displace_Allocator_Pointer;
647 ---------------------------------
648 -- Expand_Allocator_Expression --
649 ---------------------------------
651 procedure Expand_Allocator_Expression (N : Node_Id) is
652 Loc : constant Source_Ptr := Sloc (N);
653 Exp : constant Node_Id := Expression (Expression (N));
654 PtrT : constant Entity_Id := Etype (N);
655 DesigT : constant Entity_Id := Designated_Type (PtrT);
657 procedure Apply_Accessibility_Check
659 Built_In_Place : Boolean := False);
660 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
661 -- type, generate an accessibility check to verify that the level of the
662 -- type of the created object is not deeper than the level of the access
663 -- type. If the type of the qualified expression is class- wide, then
664 -- always generate the check (except in the case where it is known to be
665 -- unnecessary, see comment below). Otherwise, only generate the check
666 -- if the level of the qualified expression type is statically deeper
667 -- than the access type.
669 -- Although the static accessibility will generally have been performed
670 -- as a legality check, it won't have been done in cases where the
671 -- allocator appears in generic body, so a run-time check is needed in
672 -- general. One special case is when the access type is declared in the
673 -- same scope as the class-wide allocator, in which case the check can
674 -- never fail, so it need not be generated.
676 -- As an open issue, there seem to be cases where the static level
677 -- associated with the class-wide object's underlying type is not
678 -- sufficient to perform the proper accessibility check, such as for
679 -- allocators in nested subprograms or accept statements initialized by
680 -- class-wide formals when the actual originates outside at a deeper
681 -- static level. The nested subprogram case might require passing
682 -- accessibility levels along with class-wide parameters, and the task
683 -- case seems to be an actual gap in the language rules that needs to
684 -- be fixed by the ARG. ???
686 -------------------------------
687 -- Apply_Accessibility_Check --
688 -------------------------------
690 procedure Apply_Accessibility_Check
692 Built_In_Place : Boolean := False)
697 if Ada_Version >= Ada_2005
698 and then Is_Class_Wide_Type (DesigT)
699 and then not Scope_Suppress (Accessibility_Check)
701 (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
703 (Is_Class_Wide_Type (Etype (Exp))
704 and then Scope (PtrT) /= Current_Scope))
706 -- If the allocator was built in place Ref is already a reference
707 -- to the access object initialized to the result of the allocator
708 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise
709 -- it is the entity associated with the object containing the
710 -- address of the allocated object.
712 if Built_In_Place then
713 New_Node := New_Copy (Ref);
715 New_Node := New_Reference_To (Ref, Loc);
719 Make_Attribute_Reference (Loc,
721 Attribute_Name => Name_Tag);
723 if Tagged_Type_Expansion then
724 New_Node := Build_Get_Access_Level (Loc, New_Node);
726 elsif VM_Target /= No_VM then
728 Make_Function_Call (Loc,
729 Name => New_Reference_To (RTE (RE_Get_Access_Level), Loc),
730 Parameter_Associations => New_List (New_Node));
732 -- Cannot generate the runtime check
739 Make_Raise_Program_Error (Loc,
742 Left_Opnd => New_Node,
744 Make_Integer_Literal (Loc, Type_Access_Level (PtrT))),
745 Reason => PE_Accessibility_Check_Failed));
747 end Apply_Accessibility_Check;
751 Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
752 Indic : constant Node_Id := Subtype_Mark (Expression (N));
753 T : constant Entity_Id := Entity (Indic);
755 Tag_Assign : Node_Id;
759 TagT : Entity_Id := Empty;
760 -- Type used as source for tag assignment
762 TagR : Node_Id := Empty;
763 -- Target reference for tag assignment
765 -- Start of processing for Expand_Allocator_Expression
768 -- In the case of an Ada 2012 allocator whose initial value comes from a
769 -- function call, pass "the accessibility level determined by the point
770 -- of call" (AI05-0234) to the function. Conceptually, this belongs in
771 -- Expand_Call but it couldn't be done there (because the Etype of the
772 -- allocator wasn't set then) so we generate the parameter here. See
773 -- the Boolean variable Defer in (a block within) Expand_Call.
775 if Ada_Version >= Ada_2012 and then Nkind (Exp) = N_Function_Call then
780 if Nkind (Name (Exp)) = N_Explicit_Dereference then
781 Subp := Designated_Type (Etype (Prefix (Name (Exp))));
783 Subp := Entity (Name (Exp));
786 Subp := Ultimate_Alias (Subp);
788 if Present (Extra_Accessibility_Of_Result (Subp)) then
789 Add_Extra_Actual_To_Call
790 (Subprogram_Call => Exp,
791 Extra_Formal => Extra_Accessibility_Of_Result (Subp),
792 Extra_Actual => Dynamic_Accessibility_Level (PtrT));
797 -- Would be nice to comment the branches of this very long if ???
799 if Is_Tagged_Type (T) or else Needs_Finalization (T) then
800 if Is_CPP_Constructor_Call (Exp) then
803 -- Pnnn : constant ptr_T := new (T);
804 -- Init (Pnnn.all,...);
806 -- Allocate the object without an expression
808 Node := Relocate_Node (N);
809 Set_Expression (Node, New_Reference_To (Etype (Exp), Loc));
811 -- Avoid its expansion to avoid generating a call to the default
816 Temp := Make_Temporary (Loc, 'P', N);
819 Make_Object_Declaration (Loc,
820 Defining_Identifier => Temp,
821 Constant_Present => True,
822 Object_Definition => New_Reference_To (PtrT, Loc),
824 Insert_Action (N, Temp_Decl);
826 Apply_Accessibility_Check (Temp);
828 -- Locate the enclosing list and insert the C++ constructor call
835 while not Is_List_Member (P) loop
839 Insert_List_After_And_Analyze (P,
840 Build_Initialization_Call (Loc,
842 Make_Explicit_Dereference (Loc,
843 Prefix => New_Reference_To (Temp, Loc)),
845 Constructor_Ref => Exp));
848 Rewrite (N, New_Reference_To (Temp, Loc));
849 Analyze_And_Resolve (N, PtrT);
853 -- Ada 2005 (AI-318-02): If the initialization expression is a call
854 -- to a build-in-place function, then access to the allocated object
855 -- must be passed to the function. Currently we limit such functions
856 -- to those with constrained limited result subtypes, but eventually
857 -- we plan to expand the allowed forms of functions that are treated
858 -- as build-in-place.
860 if Ada_Version >= Ada_2005
861 and then Is_Build_In_Place_Function_Call (Exp)
863 Make_Build_In_Place_Call_In_Allocator (N, Exp);
864 Apply_Accessibility_Check (N, Built_In_Place => True);
868 -- Actions inserted before:
869 -- Temp : constant ptr_T := new T'(Expression);
870 -- Temp._tag = T'tag; -- when not class-wide
871 -- [Deep_]Adjust (Temp.all);
873 -- We analyze by hand the new internal allocator to avoid any
874 -- recursion and inappropriate call to Initialize
876 -- We don't want to remove side effects when the expression must be
877 -- built in place. In the case of a build-in-place function call,
878 -- that could lead to a duplication of the call, which was already
879 -- substituted for the allocator.
881 if not Aggr_In_Place then
882 Remove_Side_Effects (Exp);
885 Temp := Make_Temporary (Loc, 'P', N);
887 -- For a class wide allocation generate the following code:
889 -- type Equiv_Record is record ... end record;
890 -- implicit subtype CW is <Class_Wide_Subytpe>;
891 -- temp : PtrT := new CW'(CW!(expr));
893 if Is_Class_Wide_Type (T) then
894 Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
896 -- Ada 2005 (AI-251): If the expression is a class-wide interface
897 -- object we generate code to move up "this" to reference the
898 -- base of the object before allocating the new object.
900 -- Note that Exp'Address is recursively expanded into a call
901 -- to Base_Address (Exp.Tag)
903 if Is_Class_Wide_Type (Etype (Exp))
904 and then Is_Interface (Etype (Exp))
905 and then Tagged_Type_Expansion
909 Unchecked_Convert_To (Entity (Indic),
910 Make_Explicit_Dereference (Loc,
911 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
912 Make_Attribute_Reference (Loc,
914 Attribute_Name => Name_Address)))));
918 Unchecked_Convert_To (Entity (Indic), Exp));
921 Analyze_And_Resolve (Expression (N), Entity (Indic));
924 -- Processing for allocators returning non-interface types
926 if not Is_Interface (Directly_Designated_Type (PtrT)) then
927 if Aggr_In_Place then
929 Make_Object_Declaration (Loc,
930 Defining_Identifier => Temp,
931 Object_Definition => New_Reference_To (PtrT, Loc),
935 New_Reference_To (Etype (Exp), Loc)));
937 -- Copy the Comes_From_Source flag for the allocator we just
938 -- built, since logically this allocator is a replacement of
939 -- the original allocator node. This is for proper handling of
940 -- restriction No_Implicit_Heap_Allocations.
942 Set_Comes_From_Source
943 (Expression (Temp_Decl), Comes_From_Source (N));
945 Set_No_Initialization (Expression (Temp_Decl));
946 Insert_Action (N, Temp_Decl);
948 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
949 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
951 -- Attach the object to the associated finalization master.
952 -- This is done manually on .NET/JVM since those compilers do
953 -- no support pools and can't benefit from internally generated
954 -- Allocate / Deallocate procedures.
956 if VM_Target /= No_VM
957 and then Is_Controlled (DesigT)
958 and then Present (Finalization_Master (PtrT))
963 New_Reference_To (Temp, Loc),
968 Node := Relocate_Node (N);
972 Make_Object_Declaration (Loc,
973 Defining_Identifier => Temp,
974 Constant_Present => True,
975 Object_Definition => New_Reference_To (PtrT, Loc),
978 Insert_Action (N, Temp_Decl);
979 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
981 -- Attach the object to the associated finalization master.
982 -- This is done manually on .NET/JVM since those compilers do
983 -- no support pools and can't benefit from internally generated
984 -- Allocate / Deallocate procedures.
986 if VM_Target /= No_VM
987 and then Is_Controlled (DesigT)
988 and then Present (Finalization_Master (PtrT))
993 New_Reference_To (Temp, Loc),
998 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
999 -- interface type. In this case we use the type of the qualified
1000 -- expression to allocate the object.
1004 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
1009 Make_Full_Type_Declaration (Loc,
1010 Defining_Identifier => Def_Id,
1012 Make_Access_To_Object_Definition (Loc,
1013 All_Present => True,
1014 Null_Exclusion_Present => False,
1015 Constant_Present => False,
1016 Subtype_Indication =>
1017 New_Reference_To (Etype (Exp), Loc)));
1019 Insert_Action (N, New_Decl);
1021 -- Inherit the allocation-related attributes from the original
1024 Set_Finalization_Master (Def_Id, Finalization_Master (PtrT));
1026 Set_Associated_Storage_Pool (Def_Id,
1027 Associated_Storage_Pool (PtrT));
1029 -- Declare the object using the previous type declaration
1031 if Aggr_In_Place then
1033 Make_Object_Declaration (Loc,
1034 Defining_Identifier => Temp,
1035 Object_Definition => New_Reference_To (Def_Id, Loc),
1037 Make_Allocator (Loc,
1038 New_Reference_To (Etype (Exp), Loc)));
1040 -- Copy the Comes_From_Source flag for the allocator we just
1041 -- built, since logically this allocator is a replacement of
1042 -- the original allocator node. This is for proper handling
1043 -- of restriction No_Implicit_Heap_Allocations.
1045 Set_Comes_From_Source
1046 (Expression (Temp_Decl), Comes_From_Source (N));
1048 Set_No_Initialization (Expression (Temp_Decl));
1049 Insert_Action (N, Temp_Decl);
1051 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1052 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
1055 Node := Relocate_Node (N);
1056 Set_Analyzed (Node);
1059 Make_Object_Declaration (Loc,
1060 Defining_Identifier => Temp,
1061 Constant_Present => True,
1062 Object_Definition => New_Reference_To (Def_Id, Loc),
1063 Expression => Node);
1065 Insert_Action (N, Temp_Decl);
1066 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1069 -- Generate an additional object containing the address of the
1070 -- returned object. The type of this second object declaration
1071 -- is the correct type required for the common processing that
1072 -- is still performed by this subprogram. The displacement of
1073 -- this pointer to reference the component associated with the
1074 -- interface type will be done at the end of common processing.
1077 Make_Object_Declaration (Loc,
1078 Defining_Identifier => Make_Temporary (Loc, 'P'),
1079 Object_Definition => New_Reference_To (PtrT, Loc),
1081 Unchecked_Convert_To (PtrT,
1082 New_Reference_To (Temp, Loc)));
1084 Insert_Action (N, New_Decl);
1086 Temp_Decl := New_Decl;
1087 Temp := Defining_Identifier (New_Decl);
1091 Apply_Accessibility_Check (Temp);
1093 -- Generate the tag assignment
1095 -- Suppress the tag assignment when VM_Target because VM tags are
1096 -- represented implicitly in objects.
1098 if not Tagged_Type_Expansion then
1101 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
1102 -- interface objects because in this case the tag does not change.
1104 elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
1105 pragma Assert (Is_Class_Wide_Type
1106 (Directly_Designated_Type (Etype (N))));
1109 elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
1111 TagR := New_Reference_To (Temp, Loc);
1113 elsif Is_Private_Type (T)
1114 and then Is_Tagged_Type (Underlying_Type (T))
1116 TagT := Underlying_Type (T);
1118 Unchecked_Convert_To (Underlying_Type (T),
1119 Make_Explicit_Dereference (Loc,
1120 Prefix => New_Reference_To (Temp, Loc)));
1123 if Present (TagT) then
1125 Full_T : constant Entity_Id := Underlying_Type (TagT);
1128 Make_Assignment_Statement (Loc,
1130 Make_Selected_Component (Loc,
1133 New_Reference_To (First_Tag_Component (Full_T), Loc)),
1135 Unchecked_Convert_To (RTE (RE_Tag),
1138 (First_Elmt (Access_Disp_Table (Full_T))), Loc)));
1141 -- The previous assignment has to be done in any case
1143 Set_Assignment_OK (Name (Tag_Assign));
1144 Insert_Action (N, Tag_Assign);
1147 if Needs_Finalization (DesigT)
1148 and then Needs_Finalization (T)
1150 -- Generate an Adjust call if the object will be moved. In Ada
1151 -- 2005, the object may be inherently limited, in which case
1152 -- there is no Adjust procedure, and the object is built in
1153 -- place. In Ada 95, the object can be limited but not
1154 -- inherently limited if this allocator came from a return
1155 -- statement (we're allocating the result on the secondary
1156 -- stack). In that case, the object will be moved, so we _do_
1159 if not Aggr_In_Place
1160 and then not Is_Immutably_Limited_Type (T)
1166 -- An unchecked conversion is needed in the classwide
1167 -- case because the designated type can be an ancestor
1168 -- of the subtype mark of the allocator.
1170 Unchecked_Convert_To (T,
1171 Make_Explicit_Dereference (Loc,
1172 Prefix => New_Reference_To (Temp, Loc))),
1177 -- Set_Finalize_Address (<PtrT>FM, <T>FD'Unrestricted_Access);
1179 -- Do not generate this call in the following cases:
1181 -- * .NET/JVM - these targets do not support address arithmetic
1182 -- and unchecked conversion, key elements of Finalize_Address.
1184 -- * Alfa mode - the call is useless and results in unwanted
1187 -- * CodePeer mode - TSS primitive Finalize_Address is not
1188 -- created in this mode.
1190 if VM_Target = No_VM
1191 and then not Alfa_Mode
1192 and then not CodePeer_Mode
1193 and then Present (Finalization_Master (PtrT))
1194 and then Present (Temp_Decl)
1195 and then Nkind (Expression (Temp_Decl)) = N_Allocator
1198 Make_Set_Finalize_Address_Call
1205 Rewrite (N, New_Reference_To (Temp, Loc));
1206 Analyze_And_Resolve (N, PtrT);
1208 -- Ada 2005 (AI-251): Displace the pointer to reference the record
1209 -- component containing the secondary dispatch table of the interface
1212 if Is_Interface (Directly_Designated_Type (PtrT)) then
1213 Displace_Allocator_Pointer (N);
1216 elsif Aggr_In_Place then
1217 Temp := Make_Temporary (Loc, 'P', N);
1219 Make_Object_Declaration (Loc,
1220 Defining_Identifier => Temp,
1221 Object_Definition => New_Reference_To (PtrT, Loc),
1223 Make_Allocator (Loc,
1224 Expression => New_Reference_To (Etype (Exp), Loc)));
1226 -- Copy the Comes_From_Source flag for the allocator we just built,
1227 -- since logically this allocator is a replacement of the original
1228 -- allocator node. This is for proper handling of restriction
1229 -- No_Implicit_Heap_Allocations.
1231 Set_Comes_From_Source
1232 (Expression (Temp_Decl), Comes_From_Source (N));
1234 Set_No_Initialization (Expression (Temp_Decl));
1235 Insert_Action (N, Temp_Decl);
1237 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1238 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
1240 -- Attach the object to the associated finalization master. Thisis
1241 -- done manually on .NET/JVM since those compilers do no support
1242 -- pools and cannot benefit from internally generated Allocate and
1243 -- Deallocate procedures.
1245 if VM_Target /= No_VM
1246 and then Is_Controlled (DesigT)
1247 and then Present (Finalization_Master (PtrT))
1251 (Obj_Ref => New_Reference_To (Temp, Loc),
1255 Rewrite (N, New_Reference_To (Temp, Loc));
1256 Analyze_And_Resolve (N, PtrT);
1258 elsif Is_Access_Type (T)
1259 and then Can_Never_Be_Null (T)
1261 Install_Null_Excluding_Check (Exp);
1263 elsif Is_Access_Type (DesigT)
1264 and then Nkind (Exp) = N_Allocator
1265 and then Nkind (Expression (Exp)) /= N_Qualified_Expression
1267 -- Apply constraint to designated subtype indication
1269 Apply_Constraint_Check (Expression (Exp),
1270 Designated_Type (DesigT),
1271 No_Sliding => True);
1273 if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
1275 -- Propagate constraint_error to enclosing allocator
1277 Rewrite (Exp, New_Copy (Expression (Exp)));
1281 Build_Allocate_Deallocate_Proc (N, True);
1284 -- type A is access T1;
1285 -- X : A := new T2'(...);
1286 -- T1 and T2 can be different subtypes, and we might need to check
1287 -- both constraints. First check against the type of the qualified
1290 Apply_Constraint_Check (Exp, T, No_Sliding => True);
1292 if Do_Range_Check (Exp) then
1293 Set_Do_Range_Check (Exp, False);
1294 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1297 -- A check is also needed in cases where the designated subtype is
1298 -- constrained and differs from the subtype given in the qualified
1299 -- expression. Note that the check on the qualified expression does
1300 -- not allow sliding, but this check does (a relaxation from Ada 83).
1302 if Is_Constrained (DesigT)
1303 and then not Subtypes_Statically_Match (T, DesigT)
1305 Apply_Constraint_Check
1306 (Exp, DesigT, No_Sliding => False);
1308 if Do_Range_Check (Exp) then
1309 Set_Do_Range_Check (Exp, False);
1310 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1314 -- For an access to unconstrained packed array, GIGI needs to see an
1315 -- expression with a constrained subtype in order to compute the
1316 -- proper size for the allocator.
1318 if Is_Array_Type (T)
1319 and then not Is_Constrained (T)
1320 and then Is_Packed (T)
1323 ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A');
1324 Internal_Exp : constant Node_Id := Relocate_Node (Exp);
1327 Make_Subtype_Declaration (Loc,
1328 Defining_Identifier => ConstrT,
1329 Subtype_Indication =>
1330 Make_Subtype_From_Expr (Internal_Exp, T)));
1331 Freeze_Itype (ConstrT, Exp);
1332 Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
1336 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1337 -- to a build-in-place function, then access to the allocated object
1338 -- must be passed to the function. Currently we limit such functions
1339 -- to those with constrained limited result subtypes, but eventually
1340 -- we plan to expand the allowed forms of functions that are treated
1341 -- as build-in-place.
1343 if Ada_Version >= Ada_2005
1344 and then Is_Build_In_Place_Function_Call (Exp)
1346 Make_Build_In_Place_Call_In_Allocator (N, Exp);
1351 when RE_Not_Available =>
1353 end Expand_Allocator_Expression;
1355 -----------------------------
1356 -- Expand_Array_Comparison --
1357 -----------------------------
1359 -- Expansion is only required in the case of array types. For the unpacked
1360 -- case, an appropriate runtime routine is called. For packed cases, and
1361 -- also in some other cases where a runtime routine cannot be called, the
1362 -- form of the expansion is:
1364 -- [body for greater_nn; boolean_expression]
1366 -- The body is built by Make_Array_Comparison_Op, and the form of the
1367 -- Boolean expression depends on the operator involved.
1369 procedure Expand_Array_Comparison (N : Node_Id) is
1370 Loc : constant Source_Ptr := Sloc (N);
1371 Op1 : Node_Id := Left_Opnd (N);
1372 Op2 : Node_Id := Right_Opnd (N);
1373 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
1374 Ctyp : constant Entity_Id := Component_Type (Typ1);
1377 Func_Body : Node_Id;
1378 Func_Name : Entity_Id;
1382 Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
1383 -- True for byte addressable target
1385 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
1386 -- Returns True if the length of the given operand is known to be less
1387 -- than 4. Returns False if this length is known to be four or greater
1388 -- or is not known at compile time.
1390 ------------------------
1391 -- Length_Less_Than_4 --
1392 ------------------------
1394 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
1395 Otyp : constant Entity_Id := Etype (Opnd);
1398 if Ekind (Otyp) = E_String_Literal_Subtype then
1399 return String_Literal_Length (Otyp) < 4;
1403 Ityp : constant Entity_Id := Etype (First_Index (Otyp));
1404 Lo : constant Node_Id := Type_Low_Bound (Ityp);
1405 Hi : constant Node_Id := Type_High_Bound (Ityp);
1410 if Compile_Time_Known_Value (Lo) then
1411 Lov := Expr_Value (Lo);
1416 if Compile_Time_Known_Value (Hi) then
1417 Hiv := Expr_Value (Hi);
1422 return Hiv < Lov + 3;
1425 end Length_Less_Than_4;
1427 -- Start of processing for Expand_Array_Comparison
1430 -- Deal first with unpacked case, where we can call a runtime routine
1431 -- except that we avoid this for targets for which are not addressable
1432 -- by bytes, and for the JVM/CIL, since they do not support direct
1433 -- addressing of array components.
1435 if not Is_Bit_Packed_Array (Typ1)
1436 and then Byte_Addressable
1437 and then VM_Target = No_VM
1439 -- The call we generate is:
1441 -- Compare_Array_xn[_Unaligned]
1442 -- (left'address, right'address, left'length, right'length) <op> 0
1444 -- x = U for unsigned, S for signed
1445 -- n = 8,16,32,64 for component size
1446 -- Add _Unaligned if length < 4 and component size is 8.
1447 -- <op> is the standard comparison operator
1449 if Component_Size (Typ1) = 8 then
1450 if Length_Less_Than_4 (Op1)
1452 Length_Less_Than_4 (Op2)
1454 if Is_Unsigned_Type (Ctyp) then
1455 Comp := RE_Compare_Array_U8_Unaligned;
1457 Comp := RE_Compare_Array_S8_Unaligned;
1461 if Is_Unsigned_Type (Ctyp) then
1462 Comp := RE_Compare_Array_U8;
1464 Comp := RE_Compare_Array_S8;
1468 elsif Component_Size (Typ1) = 16 then
1469 if Is_Unsigned_Type (Ctyp) then
1470 Comp := RE_Compare_Array_U16;
1472 Comp := RE_Compare_Array_S16;
1475 elsif Component_Size (Typ1) = 32 then
1476 if Is_Unsigned_Type (Ctyp) then
1477 Comp := RE_Compare_Array_U32;
1479 Comp := RE_Compare_Array_S32;
1482 else pragma Assert (Component_Size (Typ1) = 64);
1483 if Is_Unsigned_Type (Ctyp) then
1484 Comp := RE_Compare_Array_U64;
1486 Comp := RE_Compare_Array_S64;
1490 Remove_Side_Effects (Op1, Name_Req => True);
1491 Remove_Side_Effects (Op2, Name_Req => True);
1494 Make_Function_Call (Sloc (Op1),
1495 Name => New_Occurrence_Of (RTE (Comp), Loc),
1497 Parameter_Associations => New_List (
1498 Make_Attribute_Reference (Loc,
1499 Prefix => Relocate_Node (Op1),
1500 Attribute_Name => Name_Address),
1502 Make_Attribute_Reference (Loc,
1503 Prefix => Relocate_Node (Op2),
1504 Attribute_Name => Name_Address),
1506 Make_Attribute_Reference (Loc,
1507 Prefix => Relocate_Node (Op1),
1508 Attribute_Name => Name_Length),
1510 Make_Attribute_Reference (Loc,
1511 Prefix => Relocate_Node (Op2),
1512 Attribute_Name => Name_Length))));
1515 Make_Integer_Literal (Sloc (Op2),
1518 Analyze_And_Resolve (Op1, Standard_Integer);
1519 Analyze_And_Resolve (Op2, Standard_Integer);
1523 -- Cases where we cannot make runtime call
1525 -- For (a <= b) we convert to not (a > b)
1527 if Chars (N) = Name_Op_Le then
1533 Right_Opnd => Op2)));
1534 Analyze_And_Resolve (N, Standard_Boolean);
1537 -- For < the Boolean expression is
1538 -- greater__nn (op2, op1)
1540 elsif Chars (N) = Name_Op_Lt then
1541 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1545 Op1 := Right_Opnd (N);
1546 Op2 := Left_Opnd (N);
1548 -- For (a >= b) we convert to not (a < b)
1550 elsif Chars (N) = Name_Op_Ge then
1556 Right_Opnd => Op2)));
1557 Analyze_And_Resolve (N, Standard_Boolean);
1560 -- For > the Boolean expression is
1561 -- greater__nn (op1, op2)
1564 pragma Assert (Chars (N) = Name_Op_Gt);
1565 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1568 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1570 Make_Function_Call (Loc,
1571 Name => New_Reference_To (Func_Name, Loc),
1572 Parameter_Associations => New_List (Op1, Op2));
1574 Insert_Action (N, Func_Body);
1576 Analyze_And_Resolve (N, Standard_Boolean);
1579 when RE_Not_Available =>
1581 end Expand_Array_Comparison;
1583 ---------------------------
1584 -- Expand_Array_Equality --
1585 ---------------------------
1587 -- Expand an equality function for multi-dimensional arrays. Here is an
1588 -- example of such a function for Nb_Dimension = 2
1590 -- function Enn (A : atyp; B : btyp) return boolean is
1592 -- if (A'length (1) = 0 or else A'length (2) = 0)
1594 -- (B'length (1) = 0 or else B'length (2) = 0)
1596 -- return True; -- RM 4.5.2(22)
1599 -- if A'length (1) /= B'length (1)
1601 -- A'length (2) /= B'length (2)
1603 -- return False; -- RM 4.5.2(23)
1607 -- A1 : Index_T1 := A'first (1);
1608 -- B1 : Index_T1 := B'first (1);
1612 -- A2 : Index_T2 := A'first (2);
1613 -- B2 : Index_T2 := B'first (2);
1616 -- if A (A1, A2) /= B (B1, B2) then
1620 -- exit when A2 = A'last (2);
1621 -- A2 := Index_T2'succ (A2);
1622 -- B2 := Index_T2'succ (B2);
1626 -- exit when A1 = A'last (1);
1627 -- A1 := Index_T1'succ (A1);
1628 -- B1 := Index_T1'succ (B1);
1635 -- Note on the formal types used (atyp and btyp). If either of the arrays
1636 -- is of a private type, we use the underlying type, and do an unchecked
1637 -- conversion of the actual. If either of the arrays has a bound depending
1638 -- on a discriminant, then we use the base type since otherwise we have an
1639 -- escaped discriminant in the function.
1641 -- If both arrays are constrained and have the same bounds, we can generate
1642 -- a loop with an explicit iteration scheme using a 'Range attribute over
1645 function Expand_Array_Equality
1650 Typ : Entity_Id) return Node_Id
1652 Loc : constant Source_Ptr := Sloc (Nod);
1653 Decls : constant List_Id := New_List;
1654 Index_List1 : constant List_Id := New_List;
1655 Index_List2 : constant List_Id := New_List;
1659 Func_Name : Entity_Id;
1660 Func_Body : Node_Id;
1662 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
1663 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
1667 -- The parameter types to be used for the formals
1672 Num : Int) return Node_Id;
1673 -- This builds the attribute reference Arr'Nam (Expr)
1675 function Component_Equality (Typ : Entity_Id) return Node_Id;
1676 -- Create one statement to compare corresponding components, designated
1677 -- by a full set of indexes.
1679 function Get_Arg_Type (N : Node_Id) return Entity_Id;
1680 -- Given one of the arguments, computes the appropriate type to be used
1681 -- for that argument in the corresponding function formal
1683 function Handle_One_Dimension
1685 Index : Node_Id) return Node_Id;
1686 -- This procedure returns the following code
1689 -- Bn : Index_T := B'First (N);
1693 -- exit when An = A'Last (N);
1694 -- An := Index_T'Succ (An)
1695 -- Bn := Index_T'Succ (Bn)
1699 -- If both indexes are constrained and identical, the procedure
1700 -- returns a simpler loop:
1702 -- for An in A'Range (N) loop
1706 -- N is the dimension for which we are generating a loop. Index is the
1707 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1708 -- xxx statement is either the loop or declare for the next dimension
1709 -- or if this is the last dimension the comparison of corresponding
1710 -- components of the arrays.
1712 -- The actual way the code works is to return the comparison of
1713 -- corresponding components for the N+1 call. That's neater!
1715 function Test_Empty_Arrays return Node_Id;
1716 -- This function constructs the test for both arrays being empty
1717 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1719 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1721 function Test_Lengths_Correspond return Node_Id;
1722 -- This function constructs the test for arrays having different lengths
1723 -- in at least one index position, in which case the resulting code is:
1725 -- A'length (1) /= B'length (1)
1727 -- A'length (2) /= B'length (2)
1738 Num : Int) return Node_Id
1742 Make_Attribute_Reference (Loc,
1743 Attribute_Name => Nam,
1744 Prefix => New_Reference_To (Arr, Loc),
1745 Expressions => New_List (Make_Integer_Literal (Loc, Num)));
1748 ------------------------
1749 -- Component_Equality --
1750 ------------------------
1752 function Component_Equality (Typ : Entity_Id) return Node_Id is
1757 -- if a(i1...) /= b(j1...) then return false; end if;
1760 Make_Indexed_Component (Loc,
1761 Prefix => Make_Identifier (Loc, Chars (A)),
1762 Expressions => Index_List1);
1765 Make_Indexed_Component (Loc,
1766 Prefix => Make_Identifier (Loc, Chars (B)),
1767 Expressions => Index_List2);
1769 Test := Expand_Composite_Equality
1770 (Nod, Component_Type (Typ), L, R, Decls);
1772 -- If some (sub)component is an unchecked_union, the whole operation
1773 -- will raise program error.
1775 if Nkind (Test) = N_Raise_Program_Error then
1777 -- This node is going to be inserted at a location where a
1778 -- statement is expected: clear its Etype so analysis will set
1779 -- it to the expected Standard_Void_Type.
1781 Set_Etype (Test, Empty);
1786 Make_Implicit_If_Statement (Nod,
1787 Condition => Make_Op_Not (Loc, Right_Opnd => Test),
1788 Then_Statements => New_List (
1789 Make_Simple_Return_Statement (Loc,
1790 Expression => New_Occurrence_Of (Standard_False, Loc))));
1792 end Component_Equality;
1798 function Get_Arg_Type (N : Node_Id) return Entity_Id is
1809 T := Underlying_Type (T);
1811 X := First_Index (T);
1812 while Present (X) loop
1813 if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
1815 Denotes_Discriminant (Type_High_Bound (Etype (X)))
1828 --------------------------
1829 -- Handle_One_Dimension --
1830 ---------------------------
1832 function Handle_One_Dimension
1834 Index : Node_Id) return Node_Id
1836 Need_Separate_Indexes : constant Boolean :=
1838 or else not Is_Constrained (Ltyp);
1839 -- If the index types are identical, and we are working with
1840 -- constrained types, then we can use the same index for both
1843 An : constant Entity_Id := Make_Temporary (Loc, 'A');
1846 Index_T : Entity_Id;
1851 if N > Number_Dimensions (Ltyp) then
1852 return Component_Equality (Ltyp);
1855 -- Case where we generate a loop
1857 Index_T := Base_Type (Etype (Index));
1859 if Need_Separate_Indexes then
1860 Bn := Make_Temporary (Loc, 'B');
1865 Append (New_Reference_To (An, Loc), Index_List1);
1866 Append (New_Reference_To (Bn, Loc), Index_List2);
1868 Stm_List := New_List (
1869 Handle_One_Dimension (N + 1, Next_Index (Index)));
1871 if Need_Separate_Indexes then
1873 -- Generate guard for loop, followed by increments of indexes
1875 Append_To (Stm_List,
1876 Make_Exit_Statement (Loc,
1879 Left_Opnd => New_Reference_To (An, Loc),
1880 Right_Opnd => Arr_Attr (A, Name_Last, N))));
1882 Append_To (Stm_List,
1883 Make_Assignment_Statement (Loc,
1884 Name => New_Reference_To (An, Loc),
1886 Make_Attribute_Reference (Loc,
1887 Prefix => New_Reference_To (Index_T, Loc),
1888 Attribute_Name => Name_Succ,
1889 Expressions => New_List (New_Reference_To (An, Loc)))));
1891 Append_To (Stm_List,
1892 Make_Assignment_Statement (Loc,
1893 Name => New_Reference_To (Bn, Loc),
1895 Make_Attribute_Reference (Loc,
1896 Prefix => New_Reference_To (Index_T, Loc),
1897 Attribute_Name => Name_Succ,
1898 Expressions => New_List (New_Reference_To (Bn, Loc)))));
1901 -- If separate indexes, we need a declare block for An and Bn, and a
1902 -- loop without an iteration scheme.
1904 if Need_Separate_Indexes then
1906 Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
1909 Make_Block_Statement (Loc,
1910 Declarations => New_List (
1911 Make_Object_Declaration (Loc,
1912 Defining_Identifier => An,
1913 Object_Definition => New_Reference_To (Index_T, Loc),
1914 Expression => Arr_Attr (A, Name_First, N)),
1916 Make_Object_Declaration (Loc,
1917 Defining_Identifier => Bn,
1918 Object_Definition => New_Reference_To (Index_T, Loc),
1919 Expression => Arr_Attr (B, Name_First, N))),
1921 Handled_Statement_Sequence =>
1922 Make_Handled_Sequence_Of_Statements (Loc,
1923 Statements => New_List (Loop_Stm)));
1925 -- If no separate indexes, return loop statement with explicit
1926 -- iteration scheme on its own
1930 Make_Implicit_Loop_Statement (Nod,
1931 Statements => Stm_List,
1933 Make_Iteration_Scheme (Loc,
1934 Loop_Parameter_Specification =>
1935 Make_Loop_Parameter_Specification (Loc,
1936 Defining_Identifier => An,
1937 Discrete_Subtype_Definition =>
1938 Arr_Attr (A, Name_Range, N))));
1941 end Handle_One_Dimension;
1943 -----------------------
1944 -- Test_Empty_Arrays --
1945 -----------------------
1947 function Test_Empty_Arrays return Node_Id is
1957 for J in 1 .. Number_Dimensions (Ltyp) loop
1960 Left_Opnd => Arr_Attr (A, Name_Length, J),
1961 Right_Opnd => Make_Integer_Literal (Loc, 0));
1965 Left_Opnd => Arr_Attr (B, Name_Length, J),
1966 Right_Opnd => Make_Integer_Literal (Loc, 0));
1975 Left_Opnd => Relocate_Node (Alist),
1976 Right_Opnd => Atest);
1980 Left_Opnd => Relocate_Node (Blist),
1981 Right_Opnd => Btest);
1988 Right_Opnd => Blist);
1989 end Test_Empty_Arrays;
1991 -----------------------------
1992 -- Test_Lengths_Correspond --
1993 -----------------------------
1995 function Test_Lengths_Correspond return Node_Id is
2001 for J in 1 .. Number_Dimensions (Ltyp) loop
2004 Left_Opnd => Arr_Attr (A, Name_Length, J),
2005 Right_Opnd => Arr_Attr (B, Name_Length, J));
2012 Left_Opnd => Relocate_Node (Result),
2013 Right_Opnd => Rtest);
2018 end Test_Lengths_Correspond;
2020 -- Start of processing for Expand_Array_Equality
2023 Ltyp := Get_Arg_Type (Lhs);
2024 Rtyp := Get_Arg_Type (Rhs);
2026 -- For now, if the argument types are not the same, go to the base type,
2027 -- since the code assumes that the formals have the same type. This is
2028 -- fixable in future ???
2030 if Ltyp /= Rtyp then
2031 Ltyp := Base_Type (Ltyp);
2032 Rtyp := Base_Type (Rtyp);
2033 pragma Assert (Ltyp = Rtyp);
2036 -- Build list of formals for function
2038 Formals := New_List (
2039 Make_Parameter_Specification (Loc,
2040 Defining_Identifier => A,
2041 Parameter_Type => New_Reference_To (Ltyp, Loc)),
2043 Make_Parameter_Specification (Loc,
2044 Defining_Identifier => B,
2045 Parameter_Type => New_Reference_To (Rtyp, Loc)));
2047 Func_Name := Make_Temporary (Loc, 'E');
2049 -- Build statement sequence for function
2052 Make_Subprogram_Body (Loc,
2054 Make_Function_Specification (Loc,
2055 Defining_Unit_Name => Func_Name,
2056 Parameter_Specifications => Formals,
2057 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
2059 Declarations => Decls,
2061 Handled_Statement_Sequence =>
2062 Make_Handled_Sequence_Of_Statements (Loc,
2063 Statements => New_List (
2065 Make_Implicit_If_Statement (Nod,
2066 Condition => Test_Empty_Arrays,
2067 Then_Statements => New_List (
2068 Make_Simple_Return_Statement (Loc,
2070 New_Occurrence_Of (Standard_True, Loc)))),
2072 Make_Implicit_If_Statement (Nod,
2073 Condition => Test_Lengths_Correspond,
2074 Then_Statements => New_List (
2075 Make_Simple_Return_Statement (Loc,
2077 New_Occurrence_Of (Standard_False, Loc)))),
2079 Handle_One_Dimension (1, First_Index (Ltyp)),
2081 Make_Simple_Return_Statement (Loc,
2082 Expression => New_Occurrence_Of (Standard_True, Loc)))));
2084 Set_Has_Completion (Func_Name, True);
2085 Set_Is_Inlined (Func_Name);
2087 -- If the array type is distinct from the type of the arguments, it
2088 -- is the full view of a private type. Apply an unchecked conversion
2089 -- to insure that analysis of the call succeeds.
2099 or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
2101 L := OK_Convert_To (Ltyp, Lhs);
2105 or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
2107 R := OK_Convert_To (Rtyp, Rhs);
2110 Actuals := New_List (L, R);
2113 Append_To (Bodies, Func_Body);
2116 Make_Function_Call (Loc,
2117 Name => New_Reference_To (Func_Name, Loc),
2118 Parameter_Associations => Actuals);
2119 end Expand_Array_Equality;
2121 -----------------------------
2122 -- Expand_Boolean_Operator --
2123 -----------------------------
2125 -- Note that we first get the actual subtypes of the operands, since we
2126 -- always want to deal with types that have bounds.
2128 procedure Expand_Boolean_Operator (N : Node_Id) is
2129 Typ : constant Entity_Id := Etype (N);
2132 -- Special case of bit packed array where both operands are known to be
2133 -- properly aligned. In this case we use an efficient run time routine
2134 -- to carry out the operation (see System.Bit_Ops).
2136 if Is_Bit_Packed_Array (Typ)
2137 and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
2138 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
2140 Expand_Packed_Boolean_Operator (N);
2144 -- For the normal non-packed case, the general expansion is to build
2145 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
2146 -- and then inserting it into the tree. The original operator node is
2147 -- then rewritten as a call to this function. We also use this in the
2148 -- packed case if either operand is a possibly unaligned object.
2151 Loc : constant Source_Ptr := Sloc (N);
2152 L : constant Node_Id := Relocate_Node (Left_Opnd (N));
2153 R : constant Node_Id := Relocate_Node (Right_Opnd (N));
2154 Func_Body : Node_Id;
2155 Func_Name : Entity_Id;
2158 Convert_To_Actual_Subtype (L);
2159 Convert_To_Actual_Subtype (R);
2160 Ensure_Defined (Etype (L), N);
2161 Ensure_Defined (Etype (R), N);
2162 Apply_Length_Check (R, Etype (L));
2164 if Nkind (N) = N_Op_Xor then
2165 Silly_Boolean_Array_Xor_Test (N, Etype (L));
2168 if Nkind (Parent (N)) = N_Assignment_Statement
2169 and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
2171 Build_Boolean_Array_Proc_Call (Parent (N), L, R);
2173 elsif Nkind (Parent (N)) = N_Op_Not
2174 and then Nkind (N) = N_Op_And
2176 Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
2181 Func_Body := Make_Boolean_Array_Op (Etype (L), N);
2182 Func_Name := Defining_Unit_Name (Specification (Func_Body));
2183 Insert_Action (N, Func_Body);
2185 -- Now rewrite the expression with a call
2188 Make_Function_Call (Loc,
2189 Name => New_Reference_To (Func_Name, Loc),
2190 Parameter_Associations =>
2193 Make_Type_Conversion
2194 (Loc, New_Reference_To (Etype (L), Loc), R))));
2196 Analyze_And_Resolve (N, Typ);
2199 end Expand_Boolean_Operator;
2201 -------------------------------
2202 -- Expand_Composite_Equality --
2203 -------------------------------
2205 -- This function is only called for comparing internal fields of composite
2206 -- types when these fields are themselves composites. This is a special
2207 -- case because it is not possible to respect normal Ada visibility rules.
2209 function Expand_Composite_Equality
2214 Bodies : List_Id) return Node_Id
2216 Loc : constant Source_Ptr := Sloc (Nod);
2217 Full_Type : Entity_Id;
2221 function Find_Primitive_Eq return Node_Id;
2222 -- AI05-0123: Locate primitive equality for type if it exists, and
2223 -- build the corresponding call. If operation is abstract, replace
2224 -- call with an explicit raise. Return Empty if there is no primitive.
2226 -----------------------
2227 -- Find_Primitive_Eq --
2228 -----------------------
2230 function Find_Primitive_Eq return Node_Id is
2235 Prim_E := First_Elmt (Collect_Primitive_Operations (Typ));
2236 while Present (Prim_E) loop
2237 Prim := Node (Prim_E);
2239 -- Locate primitive equality with the right signature
2241 if Chars (Prim) = Name_Op_Eq
2242 and then Etype (First_Formal (Prim)) =
2243 Etype (Next_Formal (First_Formal (Prim)))
2244 and then Etype (Prim) = Standard_Boolean
2246 if Is_Abstract_Subprogram (Prim) then
2248 Make_Raise_Program_Error (Loc,
2249 Reason => PE_Explicit_Raise);
2253 Make_Function_Call (Loc,
2254 Name => New_Reference_To (Prim, Loc),
2255 Parameter_Associations => New_List (Lhs, Rhs));
2262 -- If not found, predefined operation will be used
2265 end Find_Primitive_Eq;
2267 -- Start of processing for Expand_Composite_Equality
2270 if Is_Private_Type (Typ) then
2271 Full_Type := Underlying_Type (Typ);
2276 -- Defense against malformed private types with no completion the error
2277 -- will be diagnosed later by check_completion
2279 if No (Full_Type) then
2280 return New_Reference_To (Standard_False, Loc);
2283 Full_Type := Base_Type (Full_Type);
2285 if Is_Array_Type (Full_Type) then
2287 -- If the operand is an elementary type other than a floating-point
2288 -- type, then we can simply use the built-in block bitwise equality,
2289 -- since the predefined equality operators always apply and bitwise
2290 -- equality is fine for all these cases.
2292 if Is_Elementary_Type (Component_Type (Full_Type))
2293 and then not Is_Floating_Point_Type (Component_Type (Full_Type))
2295 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2297 -- For composite component types, and floating-point types, use the
2298 -- expansion. This deals with tagged component types (where we use
2299 -- the applicable equality routine) and floating-point, (where we
2300 -- need to worry about negative zeroes), and also the case of any
2301 -- composite type recursively containing such fields.
2304 return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
2307 elsif Is_Tagged_Type (Full_Type) then
2309 -- Call the primitive operation "=" of this type
2311 if Is_Class_Wide_Type (Full_Type) then
2312 Full_Type := Root_Type (Full_Type);
2315 -- If this is derived from an untagged private type completed with a
2316 -- tagged type, it does not have a full view, so we use the primitive
2317 -- operations of the private type. This check should no longer be
2318 -- necessary when these types receive their full views ???
2320 if Is_Private_Type (Typ)
2321 and then not Is_Tagged_Type (Typ)
2322 and then not Is_Controlled (Typ)
2323 and then Is_Derived_Type (Typ)
2324 and then No (Full_View (Typ))
2326 Prim := First_Elmt (Collect_Primitive_Operations (Typ));
2328 Prim := First_Elmt (Primitive_Operations (Full_Type));
2332 Eq_Op := Node (Prim);
2333 exit when Chars (Eq_Op) = Name_Op_Eq
2334 and then Etype (First_Formal (Eq_Op)) =
2335 Etype (Next_Formal (First_Formal (Eq_Op)))
2336 and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
2338 pragma Assert (Present (Prim));
2341 Eq_Op := Node (Prim);
2344 Make_Function_Call (Loc,
2345 Name => New_Reference_To (Eq_Op, Loc),
2346 Parameter_Associations =>
2348 (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
2349 Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
2351 elsif Is_Record_Type (Full_Type) then
2352 Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
2354 if Present (Eq_Op) then
2355 if Etype (First_Formal (Eq_Op)) /= Full_Type then
2357 -- Inherited equality from parent type. Convert the actuals to
2358 -- match signature of operation.
2361 T : constant Entity_Id := Etype (First_Formal (Eq_Op));
2365 Make_Function_Call (Loc,
2366 Name => New_Reference_To (Eq_Op, Loc),
2367 Parameter_Associations => New_List (
2368 OK_Convert_To (T, Lhs),
2369 OK_Convert_To (T, Rhs)));
2373 -- Comparison between Unchecked_Union components
2375 if Is_Unchecked_Union (Full_Type) then
2377 Lhs_Type : Node_Id := Full_Type;
2378 Rhs_Type : Node_Id := Full_Type;
2379 Lhs_Discr_Val : Node_Id;
2380 Rhs_Discr_Val : Node_Id;
2385 if Nkind (Lhs) = N_Selected_Component then
2386 Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
2391 if Nkind (Rhs) = N_Selected_Component then
2392 Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
2395 -- Lhs of the composite equality
2397 if Is_Constrained (Lhs_Type) then
2399 -- Since the enclosing record type can never be an
2400 -- Unchecked_Union (this code is executed for records
2401 -- that do not have variants), we may reference its
2404 if Nkind (Lhs) = N_Selected_Component
2405 and then Has_Per_Object_Constraint (
2406 Entity (Selector_Name (Lhs)))
2409 Make_Selected_Component (Loc,
2410 Prefix => Prefix (Lhs),
2413 (Get_Discriminant_Value
2414 (First_Discriminant (Lhs_Type),
2416 Stored_Constraint (Lhs_Type))));
2421 (Get_Discriminant_Value
2422 (First_Discriminant (Lhs_Type),
2424 Stored_Constraint (Lhs_Type)));
2428 -- It is not possible to infer the discriminant since
2429 -- the subtype is not constrained.
2432 Make_Raise_Program_Error (Loc,
2433 Reason => PE_Unchecked_Union_Restriction);
2436 -- Rhs of the composite equality
2438 if Is_Constrained (Rhs_Type) then
2439 if Nkind (Rhs) = N_Selected_Component
2440 and then Has_Per_Object_Constraint
2441 (Entity (Selector_Name (Rhs)))
2444 Make_Selected_Component (Loc,
2445 Prefix => Prefix (Rhs),
2448 (Get_Discriminant_Value
2449 (First_Discriminant (Rhs_Type),
2451 Stored_Constraint (Rhs_Type))));
2456 (Get_Discriminant_Value
2457 (First_Discriminant (Rhs_Type),
2459 Stored_Constraint (Rhs_Type)));
2464 Make_Raise_Program_Error (Loc,
2465 Reason => PE_Unchecked_Union_Restriction);
2468 -- Call the TSS equality function with the inferred
2469 -- discriminant values.
2472 Make_Function_Call (Loc,
2473 Name => New_Reference_To (Eq_Op, Loc),
2474 Parameter_Associations => New_List (
2483 Make_Function_Call (Loc,
2484 Name => New_Reference_To (Eq_Op, Loc),
2485 Parameter_Associations => New_List (Lhs, Rhs));
2489 elsif Ada_Version >= Ada_2012 then
2491 -- if no TSS has been created for the type, check whether there is
2492 -- a primitive equality declared for it.
2495 Ada_2012_Op : constant Node_Id := Find_Primitive_Eq;
2498 if Present (Ada_2012_Op) then
2502 -- Use predefined equality if no user-defined primitive exists
2504 return Make_Op_Eq (Loc, Lhs, Rhs);
2509 return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
2513 -- If not array or record type, it is predefined equality.
2515 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2517 end Expand_Composite_Equality;
2519 ------------------------
2520 -- Expand_Concatenate --
2521 ------------------------
2523 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
2524 Loc : constant Source_Ptr := Sloc (Cnode);
2526 Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
2527 -- Result type of concatenation
2529 Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
2530 -- Component type. Elements of this component type can appear as one
2531 -- of the operands of concatenation as well as arrays.
2533 Istyp : constant Entity_Id := Etype (First_Index (Atyp));
2536 Ityp : constant Entity_Id := Base_Type (Istyp);
2537 -- Index type. This is the base type of the index subtype, and is used
2538 -- for all computed bounds (which may be out of range of Istyp in the
2539 -- case of null ranges).
2542 -- This is the type we use to do arithmetic to compute the bounds and
2543 -- lengths of operands. The choice of this type is a little subtle and
2544 -- is discussed in a separate section at the start of the body code.
2546 Concatenation_Error : exception;
2547 -- Raised if concatenation is sure to raise a CE
2549 Result_May_Be_Null : Boolean := True;
2550 -- Reset to False if at least one operand is encountered which is known
2551 -- at compile time to be non-null. Used for handling the special case
2552 -- of setting the high bound to the last operand high bound for a null
2553 -- result, thus ensuring a proper high bound in the super-flat case.
2555 N : constant Nat := List_Length (Opnds);
2556 -- Number of concatenation operands including possibly null operands
2559 -- Number of operands excluding any known to be null, except that the
2560 -- last operand is always retained, in case it provides the bounds for
2564 -- Current operand being processed in the loop through operands. After
2565 -- this loop is complete, always contains the last operand (which is not
2566 -- the same as Operands (NN), since null operands are skipped).
2568 -- Arrays describing the operands, only the first NN entries of each
2569 -- array are set (NN < N when we exclude known null operands).
2571 Is_Fixed_Length : array (1 .. N) of Boolean;
2572 -- True if length of corresponding operand known at compile time
2574 Operands : array (1 .. N) of Node_Id;
2575 -- Set to the corresponding entry in the Opnds list (but note that null
2576 -- operands are excluded, so not all entries in the list are stored).
2578 Fixed_Length : array (1 .. N) of Uint;
2579 -- Set to length of operand. Entries in this array are set only if the
2580 -- corresponding entry in Is_Fixed_Length is True.
2582 Opnd_Low_Bound : array (1 .. N) of Node_Id;
2583 -- Set to lower bound of operand. Either an integer literal in the case
2584 -- where the bound is known at compile time, else actual lower bound.
2585 -- The operand low bound is of type Ityp.
2587 Var_Length : array (1 .. N) of Entity_Id;
2588 -- Set to an entity of type Natural that contains the length of an
2589 -- operand whose length is not known at compile time. Entries in this
2590 -- array are set only if the corresponding entry in Is_Fixed_Length
2591 -- is False. The entity is of type Artyp.
2593 Aggr_Length : array (0 .. N) of Node_Id;
2594 -- The J'th entry in an expression node that represents the total length
2595 -- of operands 1 through J. It is either an integer literal node, or a
2596 -- reference to a constant entity with the right value, so it is fine
2597 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2598 -- entry always is set to zero. The length is of type Artyp.
2600 Low_Bound : Node_Id;
2601 -- A tree node representing the low bound of the result (of type Ityp).
2602 -- This is either an integer literal node, or an identifier reference to
2603 -- a constant entity initialized to the appropriate value.
2605 Last_Opnd_High_Bound : Node_Id;
2606 -- A tree node representing the high bound of the last operand. This
2607 -- need only be set if the result could be null. It is used for the
2608 -- special case of setting the right high bound for a null result.
2609 -- This is of type Ityp.
2611 High_Bound : Node_Id;
2612 -- A tree node representing the high bound of the result (of type Ityp)
2615 -- Result of the concatenation (of type Ityp)
2617 Actions : constant List_Id := New_List;
2618 -- Collect actions to be inserted if Save_Space is False
2620 Save_Space : Boolean;
2621 pragma Warnings (Off, Save_Space);
2622 -- Set to True if we are saving generated code space by calling routines
2623 -- in packages System.Concat_n.
2625 Known_Non_Null_Operand_Seen : Boolean;
2626 -- Set True during generation of the assignments of operands into
2627 -- result once an operand known to be non-null has been seen.
2629 function Make_Artyp_Literal (Val : Nat) return Node_Id;
2630 -- This function makes an N_Integer_Literal node that is returned in
2631 -- analyzed form with the type set to Artyp. Importantly this literal
2632 -- is not flagged as static, so that if we do computations with it that
2633 -- result in statically detected out of range conditions, we will not
2634 -- generate error messages but instead warning messages.
2636 function To_Artyp (X : Node_Id) return Node_Id;
2637 -- Given a node of type Ityp, returns the corresponding value of type
2638 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2639 -- For enum types, the Pos of the value is returned.
2641 function To_Ityp (X : Node_Id) return Node_Id;
2642 -- The inverse function (uses Val in the case of enumeration types)
2644 ------------------------
2645 -- Make_Artyp_Literal --
2646 ------------------------
2648 function Make_Artyp_Literal (Val : Nat) return Node_Id is
2649 Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
2651 Set_Etype (Result, Artyp);
2652 Set_Analyzed (Result, True);
2653 Set_Is_Static_Expression (Result, False);
2655 end Make_Artyp_Literal;
2661 function To_Artyp (X : Node_Id) return Node_Id is
2663 if Ityp = Base_Type (Artyp) then
2666 elsif Is_Enumeration_Type (Ityp) then
2668 Make_Attribute_Reference (Loc,
2669 Prefix => New_Occurrence_Of (Ityp, Loc),
2670 Attribute_Name => Name_Pos,
2671 Expressions => New_List (X));
2674 return Convert_To (Artyp, X);
2682 function To_Ityp (X : Node_Id) return Node_Id is
2684 if Is_Enumeration_Type (Ityp) then
2686 Make_Attribute_Reference (Loc,
2687 Prefix => New_Occurrence_Of (Ityp, Loc),
2688 Attribute_Name => Name_Val,
2689 Expressions => New_List (X));
2691 -- Case where we will do a type conversion
2694 if Ityp = Base_Type (Artyp) then
2697 return Convert_To (Ityp, X);
2702 -- Local Declarations
2704 Opnd_Typ : Entity_Id;
2711 -- Start of processing for Expand_Concatenate
2714 -- Choose an appropriate computational type
2716 -- We will be doing calculations of lengths and bounds in this routine
2717 -- and computing one from the other in some cases, e.g. getting the high
2718 -- bound by adding the length-1 to the low bound.
2720 -- We can't just use the index type, or even its base type for this
2721 -- purpose for two reasons. First it might be an enumeration type which
2722 -- is not suitable for computations of any kind, and second it may
2723 -- simply not have enough range. For example if the index type is
2724 -- -128..+127 then lengths can be up to 256, which is out of range of
2727 -- For enumeration types, we can simply use Standard_Integer, this is
2728 -- sufficient since the actual number of enumeration literals cannot
2729 -- possibly exceed the range of integer (remember we will be doing the
2730 -- arithmetic with POS values, not representation values).
2732 if Is_Enumeration_Type (Ityp) then
2733 Artyp := Standard_Integer;
2735 -- If index type is Positive, we use the standard unsigned type, to give
2736 -- more room on the top of the range, obviating the need for an overflow
2737 -- check when creating the upper bound. This is needed to avoid junk
2738 -- overflow checks in the common case of String types.
2740 -- ??? Disabled for now
2742 -- elsif Istyp = Standard_Positive then
2743 -- Artyp := Standard_Unsigned;
2745 -- For modular types, we use a 32-bit modular type for types whose size
2746 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2747 -- identity type, and for larger unsigned types we use 64-bits.
2749 elsif Is_Modular_Integer_Type (Ityp) then
2750 if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
2751 Artyp := Standard_Unsigned;
2752 elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
2755 Artyp := RTE (RE_Long_Long_Unsigned);
2758 -- Similar treatment for signed types
2761 if RM_Size (Ityp) < RM_Size (Standard_Integer) then
2762 Artyp := Standard_Integer;
2763 elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
2766 Artyp := Standard_Long_Long_Integer;
2770 -- Supply dummy entry at start of length array
2772 Aggr_Length (0) := Make_Artyp_Literal (0);
2774 -- Go through operands setting up the above arrays
2778 Opnd := Remove_Head (Opnds);
2779 Opnd_Typ := Etype (Opnd);
2781 -- The parent got messed up when we put the operands in a list,
2782 -- so now put back the proper parent for the saved operand, that
2783 -- is to say the concatenation node, to make sure that each operand
2784 -- is seen as a subexpression, e.g. if actions must be inserted.
2786 Set_Parent (Opnd, Cnode);
2788 -- Set will be True when we have setup one entry in the array
2792 -- Singleton element (or character literal) case
2794 if Base_Type (Opnd_Typ) = Ctyp then
2796 Operands (NN) := Opnd;
2797 Is_Fixed_Length (NN) := True;
2798 Fixed_Length (NN) := Uint_1;
2799 Result_May_Be_Null := False;
2801 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2802 -- since we know that the result cannot be null).
2804 Opnd_Low_Bound (NN) :=
2805 Make_Attribute_Reference (Loc,
2806 Prefix => New_Reference_To (Istyp, Loc),
2807 Attribute_Name => Name_First);
2811 -- String literal case (can only occur for strings of course)
2813 elsif Nkind (Opnd) = N_String_Literal then
2814 Len := String_Literal_Length (Opnd_Typ);
2817 Result_May_Be_Null := False;
2820 -- Capture last operand high bound if result could be null
2822 if J = N and then Result_May_Be_Null then
2823 Last_Opnd_High_Bound :=
2826 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
2827 Right_Opnd => Make_Integer_Literal (Loc, 1));
2830 -- Skip null string literal
2832 if J < N and then Len = 0 then
2837 Operands (NN) := Opnd;
2838 Is_Fixed_Length (NN) := True;
2840 -- Set length and bounds
2842 Fixed_Length (NN) := Len;
2844 Opnd_Low_Bound (NN) :=
2845 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
2852 -- Check constrained case with known bounds
2854 if Is_Constrained (Opnd_Typ) then
2856 Index : constant Node_Id := First_Index (Opnd_Typ);
2857 Indx_Typ : constant Entity_Id := Etype (Index);
2858 Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
2859 Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
2862 -- Fixed length constrained array type with known at compile
2863 -- time bounds is last case of fixed length operand.
2865 if Compile_Time_Known_Value (Lo)
2867 Compile_Time_Known_Value (Hi)
2870 Loval : constant Uint := Expr_Value (Lo);
2871 Hival : constant Uint := Expr_Value (Hi);
2872 Len : constant Uint :=
2873 UI_Max (Hival - Loval + 1, Uint_0);
2877 Result_May_Be_Null := False;
2880 -- Capture last operand bound if result could be null
2882 if J = N and then Result_May_Be_Null then
2883 Last_Opnd_High_Bound :=
2885 Make_Integer_Literal (Loc, Expr_Value (Hi)));
2888 -- Exclude null length case unless last operand
2890 if J < N and then Len = 0 then
2895 Operands (NN) := Opnd;
2896 Is_Fixed_Length (NN) := True;
2897 Fixed_Length (NN) := Len;
2899 Opnd_Low_Bound (NN) :=
2901 (Make_Integer_Literal (Loc, Expr_Value (Lo)));
2908 -- All cases where the length is not known at compile time, or the
2909 -- special case of an operand which is known to be null but has a
2910 -- lower bound other than 1 or is other than a string type.
2915 -- Capture operand bounds
2917 Opnd_Low_Bound (NN) :=
2918 Make_Attribute_Reference (Loc,
2920 Duplicate_Subexpr (Opnd, Name_Req => True),
2921 Attribute_Name => Name_First);
2923 if J = N and Result_May_Be_Null then
2924 Last_Opnd_High_Bound :=
2926 Make_Attribute_Reference (Loc,
2928 Duplicate_Subexpr (Opnd, Name_Req => True),
2929 Attribute_Name => Name_Last));
2932 -- Capture length of operand in entity
2934 Operands (NN) := Opnd;
2935 Is_Fixed_Length (NN) := False;
2937 Var_Length (NN) := Make_Temporary (Loc, 'L');
2940 Make_Object_Declaration (Loc,
2941 Defining_Identifier => Var_Length (NN),
2942 Constant_Present => True,
2943 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2945 Make_Attribute_Reference (Loc,
2947 Duplicate_Subexpr (Opnd, Name_Req => True),
2948 Attribute_Name => Name_Length)));
2952 -- Set next entry in aggregate length array
2954 -- For first entry, make either integer literal for fixed length
2955 -- or a reference to the saved length for variable length.
2958 if Is_Fixed_Length (1) then
2959 Aggr_Length (1) := Make_Integer_Literal (Loc, Fixed_Length (1));
2961 Aggr_Length (1) := New_Reference_To (Var_Length (1), Loc);
2964 -- If entry is fixed length and only fixed lengths so far, make
2965 -- appropriate new integer literal adding new length.
2967 elsif Is_Fixed_Length (NN)
2968 and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
2971 Make_Integer_Literal (Loc,
2972 Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
2974 -- All other cases, construct an addition node for the length and
2975 -- create an entity initialized to this length.
2978 Ent := Make_Temporary (Loc, 'L');
2980 if Is_Fixed_Length (NN) then
2981 Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
2983 Clen := New_Reference_To (Var_Length (NN), Loc);
2987 Make_Object_Declaration (Loc,
2988 Defining_Identifier => Ent,
2989 Constant_Present => True,
2990 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2993 Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
2994 Right_Opnd => Clen)));
2996 Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
3003 -- If we have only skipped null operands, return the last operand
3010 -- If we have only one non-null operand, return it and we are done.
3011 -- There is one case in which this cannot be done, and that is when
3012 -- the sole operand is of the element type, in which case it must be
3013 -- converted to an array, and the easiest way of doing that is to go
3014 -- through the normal general circuit.
3017 and then Base_Type (Etype (Operands (1))) /= Ctyp
3019 Result := Operands (1);
3023 -- Cases where we have a real concatenation
3025 -- Next step is to find the low bound for the result array that we
3026 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
3028 -- If the ultimate ancestor of the index subtype is a constrained array
3029 -- definition, then the lower bound is that of the index subtype as
3030 -- specified by (RM 4.5.3(6)).
3032 -- The right test here is to go to the root type, and then the ultimate
3033 -- ancestor is the first subtype of this root type.
3035 if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
3037 Make_Attribute_Reference (Loc,
3039 New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
3040 Attribute_Name => Name_First);
3042 -- If the first operand in the list has known length we know that
3043 -- the lower bound of the result is the lower bound of this operand.
3045 elsif Is_Fixed_Length (1) then
3046 Low_Bound := Opnd_Low_Bound (1);
3048 -- OK, we don't know the lower bound, we have to build a horrible
3049 -- expression actions node of the form
3051 -- if Cond1'Length /= 0 then
3054 -- if Opnd2'Length /= 0 then
3059 -- The nesting ends either when we hit an operand whose length is known
3060 -- at compile time, or on reaching the last operand, whose low bound we
3061 -- take unconditionally whether or not it is null. It's easiest to do
3062 -- this with a recursive procedure:
3066 function Get_Known_Bound (J : Nat) return Node_Id;
3067 -- Returns the lower bound determined by operands J .. NN
3069 ---------------------
3070 -- Get_Known_Bound --
3071 ---------------------
3073 function Get_Known_Bound (J : Nat) return Node_Id is
3075 if Is_Fixed_Length (J) or else J = NN then
3076 return New_Copy (Opnd_Low_Bound (J));
3080 Make_Conditional_Expression (Loc,
3081 Expressions => New_List (
3084 Left_Opnd => New_Reference_To (Var_Length (J), Loc),
3085 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3087 New_Copy (Opnd_Low_Bound (J)),
3088 Get_Known_Bound (J + 1)));
3090 end Get_Known_Bound;
3093 Ent := Make_Temporary (Loc, 'L');
3096 Make_Object_Declaration (Loc,
3097 Defining_Identifier => Ent,
3098 Constant_Present => True,
3099 Object_Definition => New_Occurrence_Of (Ityp, Loc),
3100 Expression => Get_Known_Bound (1)));
3102 Low_Bound := New_Reference_To (Ent, Loc);
3106 -- Now we can safely compute the upper bound, normally
3107 -- Low_Bound + Length - 1.
3112 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3114 Make_Op_Subtract (Loc,
3115 Left_Opnd => New_Copy (Aggr_Length (NN)),
3116 Right_Opnd => Make_Artyp_Literal (1))));
3118 -- Note that calculation of the high bound may cause overflow in some
3119 -- very weird cases, so in the general case we need an overflow check on
3120 -- the high bound. We can avoid this for the common case of string types
3121 -- and other types whose index is Positive, since we chose a wider range
3122 -- for the arithmetic type.
3124 if Istyp /= Standard_Positive then
3125 Activate_Overflow_Check (High_Bound);
3128 -- Handle the exceptional case where the result is null, in which case
3129 -- case the bounds come from the last operand (so that we get the proper
3130 -- bounds if the last operand is super-flat).
3132 if Result_May_Be_Null then
3134 Make_Conditional_Expression (Loc,
3135 Expressions => New_List (
3137 Left_Opnd => New_Copy (Aggr_Length (NN)),
3138 Right_Opnd => Make_Artyp_Literal (0)),
3139 Last_Opnd_High_Bound,
3143 -- Here is where we insert the saved up actions
3145 Insert_Actions (Cnode, Actions, Suppress => All_Checks);
3147 -- Now we construct an array object with appropriate bounds. We mark
3148 -- the target as internal to prevent useless initialization when
3149 -- Initialize_Scalars is enabled. Also since this is the actual result
3150 -- entity, we make sure we have debug information for the result.
3152 Ent := Make_Temporary (Loc, 'S');
3153 Set_Is_Internal (Ent);
3154 Set_Needs_Debug_Info (Ent);
3156 -- If the bound is statically known to be out of range, we do not want
3157 -- to abort, we want a warning and a runtime constraint error. Note that
3158 -- we have arranged that the result will not be treated as a static
3159 -- constant, so we won't get an illegality during this insertion.
3161 Insert_Action (Cnode,
3162 Make_Object_Declaration (Loc,
3163 Defining_Identifier => Ent,
3164 Object_Definition =>
3165 Make_Subtype_Indication (Loc,
3166 Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
3168 Make_Index_Or_Discriminant_Constraint (Loc,
3169 Constraints => New_List (
3171 Low_Bound => Low_Bound,
3172 High_Bound => High_Bound))))),
3173 Suppress => All_Checks);
3175 -- If the result of the concatenation appears as the initializing
3176 -- expression of an object declaration, we can just rename the
3177 -- result, rather than copying it.
3179 Set_OK_To_Rename (Ent);
3181 -- Catch the static out of range case now
3183 if Raises_Constraint_Error (High_Bound) then
3184 raise Concatenation_Error;
3187 -- Now we will generate the assignments to do the actual concatenation
3189 -- There is one case in which we will not do this, namely when all the
3190 -- following conditions are met:
3192 -- The result type is Standard.String
3194 -- There are nine or fewer retained (non-null) operands
3196 -- The optimization level is -O0
3198 -- The corresponding System.Concat_n.Str_Concat_n routine is
3199 -- available in the run time.
3201 -- The debug flag gnatd.c is not set
3203 -- If all these conditions are met then we generate a call to the
3204 -- relevant concatenation routine. The purpose of this is to avoid
3205 -- undesirable code bloat at -O0.
3207 if Atyp = Standard_String
3208 and then NN in 2 .. 9
3209 and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC)
3210 and then not Debug_Flag_Dot_C
3213 RR : constant array (Nat range 2 .. 9) of RE_Id :=
3224 if RTE_Available (RR (NN)) then
3226 Opnds : constant List_Id :=
3227 New_List (New_Occurrence_Of (Ent, Loc));
3230 for J in 1 .. NN loop
3231 if Is_List_Member (Operands (J)) then
3232 Remove (Operands (J));
3235 if Base_Type (Etype (Operands (J))) = Ctyp then
3237 Make_Aggregate (Loc,
3238 Component_Associations => New_List (
3239 Make_Component_Association (Loc,
3240 Choices => New_List (
3241 Make_Integer_Literal (Loc, 1)),
3242 Expression => Operands (J)))));
3245 Append_To (Opnds, Operands (J));
3249 Insert_Action (Cnode,
3250 Make_Procedure_Call_Statement (Loc,
3251 Name => New_Reference_To (RTE (RR (NN)), Loc),
3252 Parameter_Associations => Opnds));
3254 Result := New_Reference_To (Ent, Loc);
3261 -- Not special case so generate the assignments
3263 Known_Non_Null_Operand_Seen := False;
3265 for J in 1 .. NN loop
3267 Lo : constant Node_Id :=
3269 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3270 Right_Opnd => Aggr_Length (J - 1));
3272 Hi : constant Node_Id :=
3274 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3276 Make_Op_Subtract (Loc,
3277 Left_Opnd => Aggr_Length (J),
3278 Right_Opnd => Make_Artyp_Literal (1)));
3281 -- Singleton case, simple assignment
3283 if Base_Type (Etype (Operands (J))) = Ctyp then
3284 Known_Non_Null_Operand_Seen := True;
3285 Insert_Action (Cnode,
3286 Make_Assignment_Statement (Loc,
3288 Make_Indexed_Component (Loc,
3289 Prefix => New_Occurrence_Of (Ent, Loc),
3290 Expressions => New_List (To_Ityp (Lo))),
3291 Expression => Operands (J)),
3292 Suppress => All_Checks);
3294 -- Array case, slice assignment, skipped when argument is fixed
3295 -- length and known to be null.
3297 elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
3300 Make_Assignment_Statement (Loc,
3304 New_Occurrence_Of (Ent, Loc),
3307 Low_Bound => To_Ityp (Lo),
3308 High_Bound => To_Ityp (Hi))),
3309 Expression => Operands (J));
3311 if Is_Fixed_Length (J) then
3312 Known_Non_Null_Operand_Seen := True;
3314 elsif not Known_Non_Null_Operand_Seen then
3316 -- Here if operand length is not statically known and no
3317 -- operand known to be non-null has been processed yet.
3318 -- If operand length is 0, we do not need to perform the
3319 -- assignment, and we must avoid the evaluation of the
3320 -- high bound of the slice, since it may underflow if the
3321 -- low bound is Ityp'First.
3324 Make_Implicit_If_Statement (Cnode,
3328 New_Occurrence_Of (Var_Length (J), Loc),
3329 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3330 Then_Statements => New_List (Assign));
3333 Insert_Action (Cnode, Assign, Suppress => All_Checks);
3339 -- Finally we build the result, which is a reference to the array object
3341 Result := New_Reference_To (Ent, Loc);
3344 Rewrite (Cnode, Result);
3345 Analyze_And_Resolve (Cnode, Atyp);
3348 when Concatenation_Error =>
3350 -- Kill warning generated for the declaration of the static out of
3351 -- range high bound, and instead generate a Constraint_Error with
3352 -- an appropriate specific message.
3354 Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
3355 Apply_Compile_Time_Constraint_Error
3357 Msg => "concatenation result upper bound out of range?",
3358 Reason => CE_Range_Check_Failed);
3359 -- Set_Etype (Cnode, Atyp);
3360 end Expand_Concatenate;
3362 ------------------------
3363 -- Expand_N_Allocator --
3364 ------------------------
3366 procedure Expand_N_Allocator (N : Node_Id) is
3367 PtrT : constant Entity_Id := Etype (N);
3368 Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT));
3369 Etyp : constant Entity_Id := Etype (Expression (N));
3370 Loc : constant Source_Ptr := Sloc (N);
3376 procedure Rewrite_Coextension (N : Node_Id);
3377 -- Static coextensions have the same lifetime as the entity they
3378 -- constrain. Such occurrences can be rewritten as aliased objects
3379 -- and their unrestricted access used instead of the coextension.
3381 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id;
3382 -- Given a constrained array type E, returns a node representing the
3383 -- code to compute the size in storage elements for the given type.
3384 -- This is done without using the attribute (which malfunctions for
3387 -------------------------
3388 -- Rewrite_Coextension --
3389 -------------------------
3391 procedure Rewrite_Coextension (N : Node_Id) is
3392 Temp_Id : constant Node_Id := Make_Temporary (Loc, 'C');
3393 Temp_Decl : Node_Id;
3394 Insert_Nod : Node_Id;
3398 -- Cnn : aliased Etyp;
3401 Make_Object_Declaration (Loc,
3402 Defining_Identifier => Temp_Id,
3403 Aliased_Present => True,
3404 Object_Definition => New_Occurrence_Of (Etyp, Loc));
3406 if Nkind (Expression (N)) = N_Qualified_Expression then
3407 Set_Expression (Temp_Decl, Expression (Expression (N)));
3410 -- Find the proper insertion node for the declaration
3412 Insert_Nod := Parent (N);
3413 while Present (Insert_Nod) loop
3415 Nkind (Insert_Nod) in N_Statement_Other_Than_Procedure_Call
3416 or else Nkind (Insert_Nod) = N_Procedure_Call_Statement
3417 or else Nkind (Insert_Nod) in N_Declaration;
3419 Insert_Nod := Parent (Insert_Nod);
3422 Insert_Before (Insert_Nod, Temp_Decl);
3423 Analyze (Temp_Decl);
3426 Make_Attribute_Reference (Loc,
3427 Prefix => New_Occurrence_Of (Temp_Id, Loc),
3428 Attribute_Name => Name_Unrestricted_Access));
3430 Analyze_And_Resolve (N, PtrT);
3431 end Rewrite_Coextension;
3433 ------------------------------
3434 -- Size_In_Storage_Elements --
3435 ------------------------------
3437 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is
3439 -- Logically this just returns E'Max_Size_In_Storage_Elements.
3440 -- However, the reason for the existence of this function is
3441 -- to construct a test for sizes too large, which means near the
3442 -- 32-bit limit on a 32-bit machine, and precisely the trouble
3443 -- is that we get overflows when sizes are greater than 2**31.
3445 -- So what we end up doing for array types is to use the expression:
3447 -- number-of-elements * component_type'Max_Size_In_Storage_Elements
3449 -- which avoids this problem. All this is a bit bogus, but it does
3450 -- mean we catch common cases of trying to allocate arrays that
3451 -- are too large, and which in the absence of a check results in
3452 -- undetected chaos ???
3459 for J in 1 .. Number_Dimensions (E) loop
3461 Make_Attribute_Reference (Loc,
3462 Prefix => New_Occurrence_Of (E, Loc),
3463 Attribute_Name => Name_Length,
3464 Expressions => New_List (Make_Integer_Literal (Loc, J)));
3471 Make_Op_Multiply (Loc,
3478 Make_Op_Multiply (Loc,
3481 Make_Attribute_Reference (Loc,
3482 Prefix => New_Occurrence_Of (Component_Type (E), Loc),
3483 Attribute_Name => Name_Max_Size_In_Storage_Elements));
3485 end Size_In_Storage_Elements;
3487 -- Start of processing for Expand_N_Allocator
3490 -- RM E.2.3(22). We enforce that the expected type of an allocator
3491 -- shall not be a remote access-to-class-wide-limited-private type
3493 -- Why is this being done at expansion time, seems clearly wrong ???
3495 Validate_Remote_Access_To_Class_Wide_Type (N);
3497 -- Processing for anonymous access-to-controlled types. These access
3498 -- types receive a special finalization master which appears in the
3499 -- declarations of the enclosing semantic unit. This expansion is done
3500 -- now to ensure that any additional types generated by this routine
3501 -- or Expand_Allocator_Expression inherit the proper type attributes.
3503 if Ekind (PtrT) = E_Anonymous_Access_Type
3504 and then Needs_Finalization (Dtyp)
3506 -- Anonymous access-to-controlled types allocate on the global pool.
3507 -- Do not set this attribute on .NET/JVM since those targets do not
3510 if No (Associated_Storage_Pool (PtrT))
3511 and then VM_Target = No_VM
3513 Set_Associated_Storage_Pool
3514 (PtrT, Get_Global_Pool_For_Access_Type (PtrT));
3517 -- The finalization master must be inserted and analyzed as part of
3518 -- the current semantic unit. This form of expansion is not carried
3519 -- out in Alfa mode because it is useless.
3521 if No (Finalization_Master (PtrT))
3522 and then not Alfa_Mode
3524 Set_Finalization_Master (PtrT, Current_Anonymous_Master);
3528 -- Set the storage pool and find the appropriate version of Allocate to
3529 -- call. Do not overwrite the storage pool if it is already set, which
3530 -- can happen for build-in-place function returns (see
3531 -- Exp_Ch4.Expand_N_Extended_Return_Statement).
3533 if No (Storage_Pool (N)) then
3534 Pool := Associated_Storage_Pool (Root_Type (PtrT));
3536 if Present (Pool) then
3537 Set_Storage_Pool (N, Pool);
3539 if Is_RTE (Pool, RE_SS_Pool) then
3540 if VM_Target = No_VM then
3541 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3544 elsif Is_Class_Wide_Type (Etype (Pool)) then
3545 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3548 Set_Procedure_To_Call (N,
3549 Find_Prim_Op (Etype (Pool), Name_Allocate));
3554 -- Under certain circumstances we can replace an allocator by an access
3555 -- to statically allocated storage. The conditions, as noted in AARM
3556 -- 3.10 (10c) are as follows:
3558 -- Size and initial value is known at compile time
3559 -- Access type is access-to-constant
3561 -- The allocator is not part of a constraint on a record component,
3562 -- because in that case the inserted actions are delayed until the
3563 -- record declaration is fully analyzed, which is too late for the
3564 -- analysis of the rewritten allocator.
3566 if Is_Access_Constant (PtrT)
3567 and then Nkind (Expression (N)) = N_Qualified_Expression
3568 and then Compile_Time_Known_Value (Expression (Expression (N)))
3569 and then Size_Known_At_Compile_Time
3570 (Etype (Expression (Expression (N))))
3571 and then not Is_Record_Type (Current_Scope)
3573 -- Here we can do the optimization. For the allocator
3577 -- We insert an object declaration
3579 -- Tnn : aliased x := y;
3581 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3582 -- marked as requiring static allocation.
3584 Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
3585 Desig := Subtype_Mark (Expression (N));
3587 -- If context is constrained, use constrained subtype directly,
3588 -- so that the constant is not labelled as having a nominally
3589 -- unconstrained subtype.
3591 if Entity (Desig) = Base_Type (Dtyp) then
3592 Desig := New_Occurrence_Of (Dtyp, Loc);
3596 Make_Object_Declaration (Loc,
3597 Defining_Identifier => Temp,
3598 Aliased_Present => True,
3599 Constant_Present => Is_Access_Constant (PtrT),
3600 Object_Definition => Desig,
3601 Expression => Expression (Expression (N))));
3604 Make_Attribute_Reference (Loc,
3605 Prefix => New_Occurrence_Of (Temp, Loc),
3606 Attribute_Name => Name_Unrestricted_Access));
3608 Analyze_And_Resolve (N, PtrT);
3610 -- We set the variable as statically allocated, since we don't want
3611 -- it going on the stack of the current procedure!
3613 Set_Is_Statically_Allocated (Temp);
3617 -- Same if the allocator is an access discriminant for a local object:
3618 -- instead of an allocator we create a local value and constrain the
3619 -- enclosing object with the corresponding access attribute.
3621 if Is_Static_Coextension (N) then
3622 Rewrite_Coextension (N);
3626 -- Check for size too large, we do this because the back end misses
3627 -- proper checks here and can generate rubbish allocation calls when
3628 -- we are near the limit. We only do this for the 32-bit address case
3629 -- since that is from a practical point of view where we see a problem.
3631 if System_Address_Size = 32
3632 and then not Storage_Checks_Suppressed (PtrT)
3633 and then not Storage_Checks_Suppressed (Dtyp)
3634 and then not Storage_Checks_Suppressed (Etyp)
3636 -- The check we want to generate should look like
3638 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
3639 -- raise Storage_Error;
3642 -- where 3.5 gigabytes is a constant large enough to accommodate any
3643 -- reasonable request for. But we can't do it this way because at
3644 -- least at the moment we don't compute this attribute right, and
3645 -- can silently give wrong results when the result gets large. Since
3646 -- this is all about large results, that's bad, so instead we only
3647 -- apply the check for constrained arrays, and manually compute the
3648 -- value of the attribute ???
3650 if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
3652 Make_Raise_Storage_Error (Loc,
3655 Left_Opnd => Size_In_Storage_Elements (Etyp),
3657 Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))),
3658 Reason => SE_Object_Too_Large));
3662 -- Handle case of qualified expression (other than optimization above)
3663 -- First apply constraint checks, because the bounds or discriminants
3664 -- in the aggregate might not match the subtype mark in the allocator.
3666 if Nkind (Expression (N)) = N_Qualified_Expression then
3667 Apply_Constraint_Check
3668 (Expression (Expression (N)), Etype (Expression (N)));
3670 Expand_Allocator_Expression (N);
3674 -- If the allocator is for a type which requires initialization, and
3675 -- there is no initial value (i.e. operand is a subtype indication
3676 -- rather than a qualified expression), then we must generate a call to
3677 -- the initialization routine using an expressions action node:
3679 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3681 -- Here ptr_T is the pointer type for the allocator, and T is the
3682 -- subtype of the allocator. A special case arises if the designated
3683 -- type of the access type is a task or contains tasks. In this case
3684 -- the call to Init (Temp.all ...) is replaced by code that ensures
3685 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3686 -- for details). In addition, if the type T is a task T, then the
3687 -- first argument to Init must be converted to the task record type.
3690 T : constant Entity_Id := Entity (Expression (N));
3696 Init_Arg1 : Node_Id;
3697 Temp_Decl : Node_Id;
3698 Temp_Type : Entity_Id;
3701 if No_Initialization (N) then
3703 -- Even though this might be a simple allocation, create a custom
3704 -- Allocate if the context requires it. Since .NET/JVM compilers
3705 -- do not support pools, this step is skipped.
3707 if VM_Target = No_VM
3708 and then Present (Finalization_Master (PtrT))
3710 Build_Allocate_Deallocate_Proc
3712 Is_Allocate => True);
3715 -- Case of no initialization procedure present
3717 elsif not Has_Non_Null_Base_Init_Proc (T) then
3719 -- Case of simple initialization required
3721 if Needs_Simple_Initialization (T) then
3722 Check_Restriction (No_Default_Initialization, N);
3723 Rewrite (Expression (N),
3724 Make_Qualified_Expression (Loc,
3725 Subtype_Mark => New_Occurrence_Of (T, Loc),
3726 Expression => Get_Simple_Init_Val (T, N)));
3728 Analyze_And_Resolve (Expression (Expression (N)), T);
3729 Analyze_And_Resolve (Expression (N), T);
3730 Set_Paren_Count (Expression (Expression (N)), 1);
3731 Expand_N_Allocator (N);
3733 -- No initialization required
3739 -- Case of initialization procedure present, must be called
3742 Check_Restriction (No_Default_Initialization, N);
3744 if not Restriction_Active (No_Default_Initialization) then
3745 Init := Base_Init_Proc (T);
3747 Temp := Make_Temporary (Loc, 'P');
3749 -- Construct argument list for the initialization routine call
3752 Make_Explicit_Dereference (Loc,
3754 New_Reference_To (Temp, Loc));
3756 Set_Assignment_OK (Init_Arg1);
3759 -- The initialization procedure expects a specific type. if the
3760 -- context is access to class wide, indicate that the object
3761 -- being allocated has the right specific type.
3763 if Is_Class_Wide_Type (Dtyp) then
3764 Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1);
3767 -- If designated type is a concurrent type or if it is private
3768 -- type whose definition is a concurrent type, the first
3769 -- argument in the Init routine has to be unchecked conversion
3770 -- to the corresponding record type. If the designated type is
3771 -- a derived type, also convert the argument to its root type.
3773 if Is_Concurrent_Type (T) then
3775 Unchecked_Convert_To (
3776 Corresponding_Record_Type (T), Init_Arg1);
3778 elsif Is_Private_Type (T)
3779 and then Present (Full_View (T))
3780 and then Is_Concurrent_Type (Full_View (T))
3783 Unchecked_Convert_To
3784 (Corresponding_Record_Type (Full_View (T)), Init_Arg1);
3786 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3788 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3791 Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1);
3792 Set_Etype (Init_Arg1, Ftyp);
3796 Args := New_List (Init_Arg1);
3798 -- For the task case, pass the Master_Id of the access type as
3799 -- the value of the _Master parameter, and _Chain as the value
3800 -- of the _Chain parameter (_Chain will be defined as part of
3801 -- the generated code for the allocator).
3803 -- In Ada 2005, the context may be a function that returns an
3804 -- anonymous access type. In that case the Master_Id has been
3805 -- created when expanding the function declaration.
3807 if Has_Task (T) then
3808 if No (Master_Id (Base_Type (PtrT))) then
3810 -- The designated type was an incomplete type, and the
3811 -- access type did not get expanded. Salvage it now.
3813 if not Restriction_Active (No_Task_Hierarchy) then
3814 pragma Assert (Present (Parent (Base_Type (PtrT))));
3815 Expand_N_Full_Type_Declaration
3816 (Parent (Base_Type (PtrT)));
3820 -- If the context of the allocator is a declaration or an
3821 -- assignment, we can generate a meaningful image for it,
3822 -- even though subsequent assignments might remove the
3823 -- connection between task and entity. We build this image
3824 -- when the left-hand side is a simple variable, a simple
3825 -- indexed assignment or a simple selected component.
3827 if Nkind (Parent (N)) = N_Assignment_Statement then
3829 Nam : constant Node_Id := Name (Parent (N));
3832 if Is_Entity_Name (Nam) then
3834 Build_Task_Image_Decls
3837 (Entity (Nam), Sloc (Nam)), T);
3839 elsif Nkind_In (Nam, N_Indexed_Component,
3840 N_Selected_Component)
3841 and then Is_Entity_Name (Prefix (Nam))
3844 Build_Task_Image_Decls
3845 (Loc, Nam, Etype (Prefix (Nam)));
3847 Decls := Build_Task_Image_Decls (Loc, T, T);
3851 elsif Nkind (Parent (N)) = N_Object_Declaration then
3853 Build_Task_Image_Decls
3854 (Loc, Defining_Identifier (Parent (N)), T);
3857 Decls := Build_Task_Image_Decls (Loc, T, T);
3860 if Restriction_Active (No_Task_Hierarchy) then
3862 New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
3866 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3869 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3871 Decl := Last (Decls);
3873 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3875 -- Has_Task is false, Decls not used
3881 -- Add discriminants if discriminated type
3884 Dis : Boolean := False;
3888 if Has_Discriminants (T) then
3892 elsif Is_Private_Type (T)
3893 and then Present (Full_View (T))
3894 and then Has_Discriminants (Full_View (T))
3897 Typ := Full_View (T);
3902 -- If the allocated object will be constrained by the
3903 -- default values for discriminants, then build a subtype
3904 -- with those defaults, and change the allocated subtype
3905 -- to that. Note that this happens in fewer cases in Ada
3908 if not Is_Constrained (Typ)
3909 and then Present (Discriminant_Default_Value
3910 (First_Discriminant (Typ)))
3911 and then (Ada_Version < Ada_2005
3913 not Has_Constrained_Partial_View (Typ))
3915 Typ := Build_Default_Subtype (Typ, N);
3916 Set_Expression (N, New_Reference_To (Typ, Loc));
3919 Discr := First_Elmt (Discriminant_Constraint (Typ));
3920 while Present (Discr) loop
3921 Nod := Node (Discr);
3922 Append (New_Copy_Tree (Node (Discr)), Args);
3924 -- AI-416: when the discriminant constraint is an
3925 -- anonymous access type make sure an accessibility
3926 -- check is inserted if necessary (3.10.2(22.q/2))
3928 if Ada_Version >= Ada_2005
3930 Ekind (Etype (Nod)) = E_Anonymous_Access_Type
3932 Apply_Accessibility_Check
3933 (Nod, Typ, Insert_Node => Nod);
3941 -- We set the allocator as analyzed so that when we analyze the
3942 -- expression actions node, we do not get an unwanted recursive
3943 -- expansion of the allocator expression.
3945 Set_Analyzed (N, True);
3946 Nod := Relocate_Node (N);
3948 -- Here is the transformation:
3949 -- input: new Ctrl_Typ
3950 -- output: Temp : constant Ctrl_Typ_Ptr := new Ctrl_Typ;
3951 -- Ctrl_TypIP (Temp.all, ...);
3952 -- [Deep_]Initialize (Temp.all);
3954 -- Here Ctrl_Typ_Ptr is the pointer type for the allocator, and
3955 -- is the subtype of the allocator.
3958 Make_Object_Declaration (Loc,
3959 Defining_Identifier => Temp,
3960 Constant_Present => True,
3961 Object_Definition => New_Reference_To (Temp_Type, Loc),
3964 Set_Assignment_OK (Temp_Decl);
3965 Insert_Action (N, Temp_Decl, Suppress => All_Checks);
3967 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
3969 -- If the designated type is a task type or contains tasks,
3970 -- create block to activate created tasks, and insert
3971 -- declaration for Task_Image variable ahead of call.
3973 if Has_Task (T) then
3975 L : constant List_Id := New_List;
3978 Build_Task_Allocate_Block (L, Nod, Args);
3980 Insert_List_Before (First (Declarations (Blk)), Decls);
3981 Insert_Actions (N, L);
3986 Make_Procedure_Call_Statement (Loc,
3987 Name => New_Reference_To (Init, Loc),
3988 Parameter_Associations => Args));
3991 if Needs_Finalization (T) then
3994 -- [Deep_]Initialize (Init_Arg1);
3998 (Obj_Ref => New_Copy_Tree (Init_Arg1),
4001 if Present (Finalization_Master (PtrT)) then
4003 -- Special processing for .NET/JVM, the allocated object
4004 -- is attached to the finalization master. Generate:
4006 -- Attach (<PtrT>FM, Root_Controlled_Ptr (Init_Arg1));
4008 -- Types derived from [Limited_]Controlled are the only
4009 -- ones considered since they have fields Prev and Next.
4011 if VM_Target /= No_VM then
4012 if Is_Controlled (T) then
4015 (Obj_Ref => New_Copy_Tree (Init_Arg1),
4019 -- Default case, generate:
4021 -- Set_Finalize_Address
4022 -- (<PtrT>FM, <T>FD'Unrestricted_Access);
4024 -- Do not generate this call in the following cases:
4026 -- * Alfa mode - the call is useless and results in
4027 -- unwanted expansion.
4029 -- * CodePeer mode - TSS primitive Finalize_Address is
4030 -- not created in this mode.
4033 and then not CodePeer_Mode
4036 Make_Set_Finalize_Address_Call
4044 Rewrite (N, New_Reference_To (Temp, Loc));
4045 Analyze_And_Resolve (N, PtrT);
4050 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
4051 -- object that has been rewritten as a reference, we displace "this"
4052 -- to reference properly its secondary dispatch table.
4054 if Nkind (N) = N_Identifier
4055 and then Is_Interface (Dtyp)
4057 Displace_Allocator_Pointer (N);
4061 when RE_Not_Available =>
4063 end Expand_N_Allocator;
4065 -----------------------
4066 -- Expand_N_And_Then --
4067 -----------------------
4069 procedure Expand_N_And_Then (N : Node_Id)
4070 renames Expand_Short_Circuit_Operator;
4072 ------------------------------
4073 -- Expand_N_Case_Expression --
4074 ------------------------------
4076 procedure Expand_N_Case_Expression (N : Node_Id) is
4077 Loc : constant Source_Ptr := Sloc (N);
4078 Typ : constant Entity_Id := Etype (N);
4090 -- case X is when A => AX, when B => BX ...
4105 -- However, this expansion is wrong for limited types, and also
4106 -- wrong for unconstrained types (since the bounds may not be the
4107 -- same in all branches). Furthermore it involves an extra copy
4108 -- for large objects. So we take care of this by using the following
4109 -- modified expansion for non-scalar types:
4112 -- type Pnn is access all typ;
4116 -- T := AX'Unrestricted_Access;
4118 -- T := BX'Unrestricted_Access;
4124 Make_Case_Statement (Loc,
4125 Expression => Expression (N),
4126 Alternatives => New_List);
4128 Actions := New_List;
4132 if Is_Scalar_Type (Typ) then
4136 Pnn := Make_Temporary (Loc, 'P');
4138 Make_Full_Type_Declaration (Loc,
4139 Defining_Identifier => Pnn,
4141 Make_Access_To_Object_Definition (Loc,
4142 All_Present => True,
4143 Subtype_Indication =>
4144 New_Reference_To (Typ, Loc))));
4148 Tnn := Make_Temporary (Loc, 'T');
4150 Make_Object_Declaration (Loc,
4151 Defining_Identifier => Tnn,
4152 Object_Definition => New_Occurrence_Of (Ttyp, Loc)));
4154 -- Now process the alternatives
4156 Alt := First (Alternatives (N));
4157 while Present (Alt) loop
4159 Aexp : Node_Id := Expression (Alt);
4160 Aloc : constant Source_Ptr := Sloc (Aexp);
4164 -- As described above, take Unrestricted_Access for case of non-
4165 -- scalar types, to avoid big copies, and special cases.
4167 if not Is_Scalar_Type (Typ) then
4169 Make_Attribute_Reference (Aloc,
4170 Prefix => Relocate_Node (Aexp),
4171 Attribute_Name => Name_Unrestricted_Access);
4175 Make_Assignment_Statement (Aloc,
4176 Name => New_Occurrence_Of (Tnn, Loc),
4177 Expression => Aexp));
4179 -- Propagate declarations inserted in the node by Insert_Actions
4180 -- (for example, temporaries generated to remove side effects).
4181 -- These actions must remain attached to the alternative, given
4182 -- that they are generated by the corresponding expression.
4184 if Present (Sinfo.Actions (Alt)) then
4185 Prepend_List (Sinfo.Actions (Alt), Stats);
4189 (Alternatives (Cstmt),
4190 Make_Case_Statement_Alternative (Sloc (Alt),
4191 Discrete_Choices => Discrete_Choices (Alt),
4192 Statements => Stats));
4198 Append_To (Actions, Cstmt);
4200 -- Construct and return final expression with actions
4202 if Is_Scalar_Type (Typ) then
4203 Fexp := New_Occurrence_Of (Tnn, Loc);
4206 Make_Explicit_Dereference (Loc,
4207 Prefix => New_Occurrence_Of (Tnn, Loc));
4211 Make_Expression_With_Actions (Loc,
4213 Actions => Actions));
4215 Analyze_And_Resolve (N, Typ);
4216 end Expand_N_Case_Expression;
4218 -------------------------------------
4219 -- Expand_N_Conditional_Expression --
4220 -------------------------------------
4222 -- Deal with limited types and expression actions
4224 procedure Expand_N_Conditional_Expression (N : Node_Id) is
4225 Loc : constant Source_Ptr := Sloc (N);
4226 Cond : constant Node_Id := First (Expressions (N));
4227 Thenx : constant Node_Id := Next (Cond);
4228 Elsex : constant Node_Id := Next (Thenx);
4229 Typ : constant Entity_Id := Etype (N);
4240 -- Fold at compile time if condition known. We have already folded
4241 -- static conditional expressions, but it is possible to fold any
4242 -- case in which the condition is known at compile time, even though
4243 -- the result is non-static.
4245 -- Note that we don't do the fold of such cases in Sem_Elab because
4246 -- it can cause infinite loops with the expander adding a conditional
4247 -- expression, and Sem_Elab circuitry removing it repeatedly.
4249 if Compile_Time_Known_Value (Cond) then
4250 if Is_True (Expr_Value (Cond)) then
4252 Actions := Then_Actions (N);
4255 Actions := Else_Actions (N);
4260 if Present (Actions) then
4262 -- If we are not allowed to use Expression_With_Actions, just skip
4263 -- the optimization, it is not critical for correctness.
4265 if not Use_Expression_With_Actions then
4266 goto Skip_Optimization;
4270 Make_Expression_With_Actions (Loc,
4271 Expression => Relocate_Node (Expr),
4272 Actions => Actions));
4273 Analyze_And_Resolve (N, Typ);
4276 Rewrite (N, Relocate_Node (Expr));
4279 -- Note that the result is never static (legitimate cases of static
4280 -- conditional expressions were folded in Sem_Eval).
4282 Set_Is_Static_Expression (N, False);
4286 <<Skip_Optimization>>
4288 -- If the type is limited or unconstrained, we expand as follows to
4289 -- avoid any possibility of improper copies.
4291 -- Note: it may be possible to avoid this special processing if the
4292 -- back end uses its own mechanisms for handling by-reference types ???
4294 -- type Ptr is access all Typ;
4298 -- Cnn := then-expr'Unrestricted_Access;
4301 -- Cnn := else-expr'Unrestricted_Access;
4304 -- and replace the conditional expression by a reference to Cnn.all.
4306 -- This special case can be skipped if the back end handles limited
4307 -- types properly and ensures that no incorrect copies are made.
4309 if Is_By_Reference_Type (Typ)
4310 and then not Back_End_Handles_Limited_Types
4312 Cnn := Make_Temporary (Loc, 'C', N);
4315 Make_Full_Type_Declaration (Loc,
4316 Defining_Identifier =>
4317 Make_Temporary (Loc, 'A'),
4319 Make_Access_To_Object_Definition (Loc,
4320 All_Present => True,
4321 Subtype_Indication => New_Reference_To (Typ, Loc)));
4323 Insert_Action (N, P_Decl);
4326 Make_Object_Declaration (Loc,
4327 Defining_Identifier => Cnn,
4328 Object_Definition =>
4329 New_Occurrence_Of (Defining_Identifier (P_Decl), Loc));
4332 Make_Implicit_If_Statement (N,
4333 Condition => Relocate_Node (Cond),
4335 Then_Statements => New_List (
4336 Make_Assignment_Statement (Sloc (Thenx),
4337 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4339 Make_Attribute_Reference (Loc,
4340 Attribute_Name => Name_Unrestricted_Access,
4341 Prefix => Relocate_Node (Thenx)))),
4343 Else_Statements => New_List (
4344 Make_Assignment_Statement (Sloc (Elsex),
4345 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4347 Make_Attribute_Reference (Loc,
4348 Attribute_Name => Name_Unrestricted_Access,
4349 Prefix => Relocate_Node (Elsex)))));
4352 Make_Explicit_Dereference (Loc,
4353 Prefix => New_Occurrence_Of (Cnn, Loc));
4355 -- For other types, we only need to expand if there are other actions
4356 -- associated with either branch.
4358 elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
4360 -- We have two approaches to handling this. If we are allowed to use
4361 -- N_Expression_With_Actions, then we can just wrap the actions into
4362 -- the appropriate expression.
4364 if Use_Expression_With_Actions then
4365 if Present (Then_Actions (N)) then
4367 Make_Expression_With_Actions (Sloc (Thenx),
4368 Actions => Then_Actions (N),
4369 Expression => Relocate_Node (Thenx)));
4370 Set_Then_Actions (N, No_List);
4371 Analyze_And_Resolve (Thenx, Typ);
4374 if Present (Else_Actions (N)) then
4376 Make_Expression_With_Actions (Sloc (Elsex),
4377 Actions => Else_Actions (N),
4378 Expression => Relocate_Node (Elsex)));
4379 Set_Else_Actions (N, No_List);
4380 Analyze_And_Resolve (Elsex, Typ);
4385 -- if we can't use N_Expression_With_Actions nodes, then we insert
4386 -- the following sequence of actions (using Insert_Actions):
4391 -- Cnn := then-expr;
4397 -- and replace the conditional expression by a reference to Cnn
4400 Cnn := Make_Temporary (Loc, 'C', N);
4403 Make_Object_Declaration (Loc,
4404 Defining_Identifier => Cnn,
4405 Object_Definition => New_Occurrence_Of (Typ, Loc));
4408 Make_Implicit_If_Statement (N,
4409 Condition => Relocate_Node (Cond),
4411 Then_Statements => New_List (
4412 Make_Assignment_Statement (Sloc (Thenx),
4413 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4414 Expression => Relocate_Node (Thenx))),
4416 Else_Statements => New_List (
4417 Make_Assignment_Statement (Sloc (Elsex),
4418 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4419 Expression => Relocate_Node (Elsex))));
4421 Set_Assignment_OK (Name (First (Then_Statements (New_If))));
4422 Set_Assignment_OK (Name (First (Else_Statements (New_If))));
4424 New_N := New_Occurrence_Of (Cnn, Loc);
4427 -- If no actions then no expansion needed, gigi will handle it using
4428 -- the same approach as a C conditional expression.
4434 -- Fall through here for either the limited expansion, or the case of
4435 -- inserting actions for non-limited types. In both these cases, we must
4436 -- move the SLOC of the parent If statement to the newly created one and
4437 -- change it to the SLOC of the expression which, after expansion, will
4438 -- correspond to what is being evaluated.
4440 if Present (Parent (N))
4441 and then Nkind (Parent (N)) = N_If_Statement
4443 Set_Sloc (New_If, Sloc (Parent (N)));
4444 Set_Sloc (Parent (N), Loc);
4447 -- Make sure Then_Actions and Else_Actions are appropriately moved
4448 -- to the new if statement.
4450 if Present (Then_Actions (N)) then
4452 (First (Then_Statements (New_If)), Then_Actions (N));
4455 if Present (Else_Actions (N)) then
4457 (First (Else_Statements (New_If)), Else_Actions (N));
4460 Insert_Action (N, Decl);
4461 Insert_Action (N, New_If);
4463 Analyze_And_Resolve (N, Typ);
4464 end Expand_N_Conditional_Expression;
4466 -----------------------------------
4467 -- Expand_N_Explicit_Dereference --
4468 -----------------------------------
4470 procedure Expand_N_Explicit_Dereference (N : Node_Id) is
4472 -- Insert explicit dereference call for the checked storage pool case
4474 Insert_Dereference_Action (Prefix (N));
4475 end Expand_N_Explicit_Dereference;
4477 --------------------------------------
4478 -- Expand_N_Expression_With_Actions --
4479 --------------------------------------
4481 procedure Expand_N_Expression_With_Actions (N : Node_Id) is
4483 procedure Process_Transient_Object (Decl : Node_Id);
4484 -- Given the declaration of a controlled transient declared inside the
4485 -- Actions list of an Expression_With_Actions, generate all necessary
4486 -- types and hooks in order to properly finalize the transient. This
4487 -- mechanism works in conjunction with Build_Finalizer.
4489 ------------------------------
4490 -- Process_Transient_Object --
4491 ------------------------------
4493 procedure Process_Transient_Object (Decl : Node_Id) is
4495 function Find_Insertion_Node return Node_Id;
4496 -- Complex conditions in if statements may be converted into nested
4497 -- EWAs. In this case, any generated code must be inserted before the
4498 -- if statement to ensure proper visibility of the hook objects. This
4499 -- routine returns the top most short circuit operator or the parent
4500 -- of the EWA if no nesting was detected.
4502 -------------------------
4503 -- Find_Insertion_Node --
4504 -------------------------
4506 function Find_Insertion_Node return Node_Id is
4510 -- Climb up the branches of a complex condition
4513 while Nkind_In (Parent (Par), N_And_Then, N_Op_Not, N_Or_Else) loop
4514 Par := Parent (Par);
4518 end Find_Insertion_Node;
4522 Ins_Node : constant Node_Id := Find_Insertion_Node;
4523 Loc : constant Source_Ptr := Sloc (Decl);
4524 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
4525 Obj_Typ : constant Entity_Id := Etype (Obj_Id);
4526 Desig_Typ : Entity_Id;
4530 Temp_Decl : Node_Id;
4533 -- Start of processing for Process_Transient_Object
4536 -- Step 1: Create the access type which provides a reference to the
4537 -- transient object.
4539 if Is_Access_Type (Obj_Typ) then
4540 Desig_Typ := Directly_Designated_Type (Obj_Typ);
4542 Desig_Typ := Obj_Typ;
4546 -- Ann : access [all] <Desig_Typ>;
4548 Ptr_Id := Make_Temporary (Loc, 'A');
4551 Make_Full_Type_Declaration (Loc,
4552 Defining_Identifier => Ptr_Id,
4554 Make_Access_To_Object_Definition (Loc,
4556 Ekind (Obj_Typ) = E_General_Access_Type,
4557 Subtype_Indication => New_Reference_To (Desig_Typ, Loc)));
4559 Insert_Action (Ins_Node, Ptr_Decl);
4562 -- Step 2: Create a temporary which acts as a hook to the transient
4563 -- object. Generate:
4565 -- Temp : Ptr_Id := null;
4567 Temp_Id := Make_Temporary (Loc, 'T');
4570 Make_Object_Declaration (Loc,
4571 Defining_Identifier => Temp_Id,
4572 Object_Definition => New_Reference_To (Ptr_Id, Loc));
4574 Insert_Action (Ins_Node, Temp_Decl);
4575 Analyze (Temp_Decl);
4577 -- Mark this temporary as created for the purposes of exporting the
4578 -- transient declaration out of the Actions list. This signals the
4579 -- machinery in Build_Finalizer to recognize this special case.
4581 Set_Return_Flag_Or_Transient_Decl (Temp_Id, Decl);
4583 -- Step 3: Hook the transient object to the temporary
4585 if Is_Access_Type (Obj_Typ) then
4586 Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc));
4589 Make_Attribute_Reference (Loc,
4590 Prefix => New_Reference_To (Obj_Id, Loc),
4591 Attribute_Name => Name_Unrestricted_Access);
4595 -- Temp := Ptr_Id (Obj_Id);
4597 -- Temp := Obj_Id'Unrestricted_Access;
4599 Insert_After_And_Analyze (Decl,
4600 Make_Assignment_Statement (Loc,
4601 Name => New_Reference_To (Temp_Id, Loc),
4602 Expression => Expr));
4603 end Process_Transient_Object;
4609 -- Start of processing for Expand_N_Expression_With_Actions
4612 Decl := First (Actions (N));
4613 while Present (Decl) loop
4614 if Nkind (Decl) = N_Object_Declaration
4615 and then Is_Finalizable_Transient (Decl, N)
4617 Process_Transient_Object (Decl);
4622 end Expand_N_Expression_With_Actions;
4628 procedure Expand_N_In (N : Node_Id) is
4629 Loc : constant Source_Ptr := Sloc (N);
4630 Restyp : constant Entity_Id := Etype (N);
4631 Lop : constant Node_Id := Left_Opnd (N);
4632 Rop : constant Node_Id := Right_Opnd (N);
4633 Static : constant Boolean := Is_OK_Static_Expression (N);
4638 procedure Substitute_Valid_Check;
4639 -- Replaces node N by Lop'Valid. This is done when we have an explicit
4640 -- test for the left operand being in range of its subtype.
4642 ----------------------------
4643 -- Substitute_Valid_Check --
4644 ----------------------------
4646 procedure Substitute_Valid_Check is
4649 Make_Attribute_Reference (Loc,
4650 Prefix => Relocate_Node (Lop),
4651 Attribute_Name => Name_Valid));
4653 Analyze_And_Resolve (N, Restyp);
4655 Error_Msg_N ("?explicit membership test may be optimized away", N);
4656 Error_Msg_N -- CODEFIX
4657 ("\?use ''Valid attribute instead", N);
4659 end Substitute_Valid_Check;
4661 -- Start of processing for Expand_N_In
4664 -- If set membership case, expand with separate procedure
4666 if Present (Alternatives (N)) then
4667 Expand_Set_Membership (N);
4671 -- Not set membership, proceed with expansion
4673 Ltyp := Etype (Left_Opnd (N));
4674 Rtyp := Etype (Right_Opnd (N));
4676 -- Check case of explicit test for an expression in range of its
4677 -- subtype. This is suspicious usage and we replace it with a 'Valid
4678 -- test and give a warning. For floating point types however, this is a
4679 -- standard way to check for finite numbers, and using 'Valid would
4680 -- typically be a pessimization. Also skip this test for predicated
4681 -- types, since it is perfectly reasonable to check if a value meets
4684 if Is_Scalar_Type (Ltyp)
4685 and then not Is_Floating_Point_Type (Ltyp)
4686 and then Nkind (Rop) in N_Has_Entity
4687 and then Ltyp = Entity (Rop)
4688 and then Comes_From_Source (N)
4689 and then VM_Target = No_VM
4690 and then not (Is_Discrete_Type (Ltyp)
4691 and then Present (Predicate_Function (Ltyp)))
4693 Substitute_Valid_Check;
4697 -- Do validity check on operands
4699 if Validity_Checks_On and Validity_Check_Operands then
4700 Ensure_Valid (Left_Opnd (N));
4701 Validity_Check_Range (Right_Opnd (N));
4704 -- Case of explicit range
4706 if Nkind (Rop) = N_Range then
4708 Lo : constant Node_Id := Low_Bound (Rop);
4709 Hi : constant Node_Id := High_Bound (Rop);
4711 Lo_Orig : constant Node_Id := Original_Node (Lo);
4712 Hi_Orig : constant Node_Id := Original_Node (Hi);
4714 Lcheck : Compare_Result;
4715 Ucheck : Compare_Result;
4717 Warn1 : constant Boolean :=
4718 Constant_Condition_Warnings
4719 and then Comes_From_Source (N)
4720 and then not In_Instance;
4721 -- This must be true for any of the optimization warnings, we
4722 -- clearly want to give them only for source with the flag on. We
4723 -- also skip these warnings in an instance since it may be the
4724 -- case that different instantiations have different ranges.
4726 Warn2 : constant Boolean :=
4728 and then Nkind (Original_Node (Rop)) = N_Range
4729 and then Is_Integer_Type (Etype (Lo));
4730 -- For the case where only one bound warning is elided, we also
4731 -- insist on an explicit range and an integer type. The reason is
4732 -- that the use of enumeration ranges including an end point is
4733 -- common, as is the use of a subtype name, one of whose bounds is
4734 -- the same as the type of the expression.
4737 -- If test is explicit x'First .. x'Last, replace by valid check
4739 -- Could use some individual comments for this complex test ???
4741 if Is_Scalar_Type (Ltyp)
4742 and then Nkind (Lo_Orig) = N_Attribute_Reference
4743 and then Attribute_Name (Lo_Orig) = Name_First
4744 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
4745 and then Entity (Prefix (Lo_Orig)) = Ltyp
4746 and then Nkind (Hi_Orig) = N_Attribute_Reference
4747 and then Attribute_Name (Hi_Orig) = Name_Last
4748 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
4749 and then Entity (Prefix (Hi_Orig)) = Ltyp
4750 and then Comes_From_Source (N)
4751 and then VM_Target = No_VM
4753 Substitute_Valid_Check;
4757 -- If bounds of type are known at compile time, and the end points
4758 -- are known at compile time and identical, this is another case
4759 -- for substituting a valid test. We only do this for discrete
4760 -- types, since it won't arise in practice for float types.
4762 if Comes_From_Source (N)
4763 and then Is_Discrete_Type (Ltyp)
4764 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
4765 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
4766 and then Compile_Time_Known_Value (Lo)
4767 and then Compile_Time_Known_Value (Hi)
4768 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
4769 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
4771 -- Kill warnings in instances, since they may be cases where we
4772 -- have a test in the generic that makes sense with some types
4773 -- and not with other types.
4775 and then not In_Instance
4777 Substitute_Valid_Check;
4781 -- If we have an explicit range, do a bit of optimization based on
4782 -- range analysis (we may be able to kill one or both checks).
4784 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
4785 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
4787 -- If either check is known to fail, replace result by False since
4788 -- the other check does not matter. Preserve the static flag for
4789 -- legality checks, because we are constant-folding beyond RM 4.9.
4791 if Lcheck = LT or else Ucheck = GT then
4793 Error_Msg_N ("?range test optimized away", N);
4794 Error_Msg_N ("\?value is known to be out of range", N);
4797 Rewrite (N, New_Reference_To (Standard_False, Loc));
4798 Analyze_And_Resolve (N, Restyp);
4799 Set_Is_Static_Expression (N, Static);
4802 -- If both checks are known to succeed, replace result by True,
4803 -- since we know we are in range.
4805 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4807 Error_Msg_N ("?range test optimized away", N);
4808 Error_Msg_N ("\?value is known to be in range", N);
4811 Rewrite (N, New_Reference_To (Standard_True, Loc));
4812 Analyze_And_Resolve (N, Restyp);
4813 Set_Is_Static_Expression (N, Static);
4816 -- If lower bound check succeeds and upper bound check is not
4817 -- known to succeed or fail, then replace the range check with
4818 -- a comparison against the upper bound.
4820 elsif Lcheck in Compare_GE then
4821 if Warn2 and then not In_Instance then
4822 Error_Msg_N ("?lower bound test optimized away", Lo);
4823 Error_Msg_N ("\?value is known to be in range", Lo);
4829 Right_Opnd => High_Bound (Rop)));
4830 Analyze_And_Resolve (N, Restyp);
4833 -- If upper bound check succeeds and lower bound check is not
4834 -- known to succeed or fail, then replace the range check with
4835 -- a comparison against the lower bound.
4837 elsif Ucheck in Compare_LE then
4838 if Warn2 and then not In_Instance then
4839 Error_Msg_N ("?upper bound test optimized away", Hi);
4840 Error_Msg_N ("\?value is known to be in range", Hi);
4846 Right_Opnd => Low_Bound (Rop)));
4847 Analyze_And_Resolve (N, Restyp);
4851 -- We couldn't optimize away the range check, but there is one
4852 -- more issue. If we are checking constant conditionals, then we
4853 -- see if we can determine the outcome assuming everything is
4854 -- valid, and if so give an appropriate warning.
4856 if Warn1 and then not Assume_No_Invalid_Values then
4857 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4858 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4860 -- Result is out of range for valid value
4862 if Lcheck = LT or else Ucheck = GT then
4864 ("?value can only be in range if it is invalid", N);
4866 -- Result is in range for valid value
4868 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4870 ("?value can only be out of range if it is invalid", N);
4872 -- Lower bound check succeeds if value is valid
4874 elsif Warn2 and then Lcheck in Compare_GE then
4876 ("?lower bound check only fails if it is invalid", Lo);
4878 -- Upper bound check succeeds if value is valid
4880 elsif Warn2 and then Ucheck in Compare_LE then
4882 ("?upper bound check only fails for invalid values", Hi);
4887 -- For all other cases of an explicit range, nothing to be done
4891 -- Here right operand is a subtype mark
4895 Typ : Entity_Id := Etype (Rop);
4896 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4897 Cond : Node_Id := Empty;
4899 Obj : Node_Id := Lop;
4900 SCIL_Node : Node_Id;
4903 Remove_Side_Effects (Obj);
4905 -- For tagged type, do tagged membership operation
4907 if Is_Tagged_Type (Typ) then
4909 -- No expansion will be performed when VM_Target, as the VM
4910 -- back-ends will handle the membership tests directly (tags
4911 -- are not explicitly represented in Java objects, so the
4912 -- normal tagged membership expansion is not what we want).
4914 if Tagged_Type_Expansion then
4915 Tagged_Membership (N, SCIL_Node, New_N);
4917 Analyze_And_Resolve (N, Restyp);
4919 -- Update decoration of relocated node referenced by the
4922 if Generate_SCIL and then Present (SCIL_Node) then
4923 Set_SCIL_Node (N, SCIL_Node);
4929 -- If type is scalar type, rewrite as x in t'First .. t'Last.
4930 -- This reason we do this is that the bounds may have the wrong
4931 -- type if they come from the original type definition. Also this
4932 -- way we get all the processing above for an explicit range.
4934 -- Don't do this for predicated types, since in this case we
4935 -- want to check the predicate!
4937 elsif Is_Scalar_Type (Typ) then
4938 if No (Predicate_Function (Typ)) then
4942 Make_Attribute_Reference (Loc,
4943 Attribute_Name => Name_First,
4944 Prefix => New_Reference_To (Typ, Loc)),
4947 Make_Attribute_Reference (Loc,
4948 Attribute_Name => Name_Last,
4949 Prefix => New_Reference_To (Typ, Loc))));
4950 Analyze_And_Resolve (N, Restyp);
4955 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4956 -- a membership test if the subtype mark denotes a constrained
4957 -- Unchecked_Union subtype and the expression lacks inferable
4960 elsif Is_Unchecked_Union (Base_Type (Typ))
4961 and then Is_Constrained (Typ)
4962 and then not Has_Inferable_Discriminants (Lop)
4965 Make_Raise_Program_Error (Loc,
4966 Reason => PE_Unchecked_Union_Restriction));
4968 -- Prevent Gigi from generating incorrect code by rewriting the
4971 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
4975 -- Here we have a non-scalar type
4978 Typ := Designated_Type (Typ);
4981 if not Is_Constrained (Typ) then
4982 Rewrite (N, New_Reference_To (Standard_True, Loc));
4983 Analyze_And_Resolve (N, Restyp);
4985 -- For the constrained array case, we have to check the subscripts
4986 -- for an exact match if the lengths are non-zero (the lengths
4987 -- must match in any case).
4989 elsif Is_Array_Type (Typ) then
4990 Check_Subscripts : declare
4991 function Build_Attribute_Reference
4994 Dim : Nat) return Node_Id;
4995 -- Build attribute reference E'Nam (Dim)
4997 -------------------------------
4998 -- Build_Attribute_Reference --
4999 -------------------------------
5001 function Build_Attribute_Reference
5004 Dim : Nat) return Node_Id
5008 Make_Attribute_Reference (Loc,
5010 Attribute_Name => Nam,
5011 Expressions => New_List (
5012 Make_Integer_Literal (Loc, Dim)));
5013 end Build_Attribute_Reference;
5015 -- Start of processing for Check_Subscripts
5018 for J in 1 .. Number_Dimensions (Typ) loop
5019 Evolve_And_Then (Cond,
5022 Build_Attribute_Reference
5023 (Duplicate_Subexpr_No_Checks (Obj),
5026 Build_Attribute_Reference
5027 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
5029 Evolve_And_Then (Cond,
5032 Build_Attribute_Reference
5033 (Duplicate_Subexpr_No_Checks (Obj),
5036 Build_Attribute_Reference
5037 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
5046 Right_Opnd => Make_Null (Loc)),
5047 Right_Opnd => Cond);
5051 Analyze_And_Resolve (N, Restyp);
5052 end Check_Subscripts;
5054 -- These are the cases where constraint checks may be required,
5055 -- e.g. records with possible discriminants
5058 -- Expand the test into a series of discriminant comparisons.
5059 -- The expression that is built is the negation of the one that
5060 -- is used for checking discriminant constraints.
5062 Obj := Relocate_Node (Left_Opnd (N));
5064 if Has_Discriminants (Typ) then
5065 Cond := Make_Op_Not (Loc,
5066 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
5069 Cond := Make_Or_Else (Loc,
5073 Right_Opnd => Make_Null (Loc)),
5074 Right_Opnd => Cond);
5078 Cond := New_Occurrence_Of (Standard_True, Loc);
5082 Analyze_And_Resolve (N, Restyp);
5085 -- Ada 2012 (AI05-0149): Handle membership tests applied to an
5086 -- expression of an anonymous access type. This can involve an
5087 -- accessibility test and a tagged type membership test in the
5088 -- case of tagged designated types.
5090 if Ada_Version >= Ada_2012
5092 and then Ekind (Ltyp) = E_Anonymous_Access_Type
5095 Expr_Entity : Entity_Id := Empty;
5097 Param_Level : Node_Id;
5098 Type_Level : Node_Id;
5101 if Is_Entity_Name (Lop) then
5102 Expr_Entity := Param_Entity (Lop);
5104 if not Present (Expr_Entity) then
5105 Expr_Entity := Entity (Lop);
5109 -- If a conversion of the anonymous access value to the
5110 -- tested type would be illegal, then the result is False.
5112 if not Valid_Conversion
5113 (Lop, Rtyp, Lop, Report_Errs => False)
5115 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5116 Analyze_And_Resolve (N, Restyp);
5118 -- Apply an accessibility check if the access object has an
5119 -- associated access level and when the level of the type is
5120 -- less deep than the level of the access parameter. This
5121 -- only occur for access parameters and stand-alone objects
5122 -- of an anonymous access type.
5125 if Present (Expr_Entity)
5128 (Effective_Extra_Accessibility (Expr_Entity))
5129 and then UI_Gt (Object_Access_Level (Lop),
5130 Type_Access_Level (Rtyp))
5134 (Effective_Extra_Accessibility (Expr_Entity), Loc);
5137 Make_Integer_Literal (Loc, Type_Access_Level (Rtyp));
5139 -- Return True only if the accessibility level of the
5140 -- expression entity is not deeper than the level of
5141 -- the tested access type.
5145 Left_Opnd => Relocate_Node (N),
5146 Right_Opnd => Make_Op_Le (Loc,
5147 Left_Opnd => Param_Level,
5148 Right_Opnd => Type_Level)));
5150 Analyze_And_Resolve (N);
5153 -- If the designated type is tagged, do tagged membership
5156 -- *** NOTE: we have to check not null before doing the
5157 -- tagged membership test (but maybe that can be done
5158 -- inside Tagged_Membership?).
5160 if Is_Tagged_Type (Typ) then
5163 Left_Opnd => Relocate_Node (N),
5167 Right_Opnd => Make_Null (Loc))));
5169 -- No expansion will be performed when VM_Target, as
5170 -- the VM back-ends will handle the membership tests
5171 -- directly (tags are not explicitly represented in
5172 -- Java objects, so the normal tagged membership
5173 -- expansion is not what we want).
5175 if Tagged_Type_Expansion then
5177 -- Note that we have to pass Original_Node, because
5178 -- the membership test might already have been
5179 -- rewritten by earlier parts of membership test.
5182 (Original_Node (N), SCIL_Node, New_N);
5184 -- Update decoration of relocated node referenced
5185 -- by the SCIL node.
5187 if Generate_SCIL and then Present (SCIL_Node) then
5188 Set_SCIL_Node (New_N, SCIL_Node);
5193 Left_Opnd => Relocate_Node (N),
5194 Right_Opnd => New_N));
5196 Analyze_And_Resolve (N, Restyp);
5205 -- At this point, we have done the processing required for the basic
5206 -- membership test, but not yet dealt with the predicate.
5210 -- If a predicate is present, then we do the predicate test, but we
5211 -- most certainly want to omit this if we are within the predicate
5212 -- function itself, since otherwise we have an infinite recursion!
5215 PFunc : constant Entity_Id := Predicate_Function (Rtyp);
5219 and then Current_Scope /= PFunc
5223 Left_Opnd => Relocate_Node (N),
5224 Right_Opnd => Make_Predicate_Call (Rtyp, Lop)));
5226 -- Analyze new expression, mark left operand as analyzed to
5227 -- avoid infinite recursion adding predicate calls.
5229 Set_Analyzed (Left_Opnd (N));
5230 Analyze_And_Resolve (N, Standard_Boolean);
5232 -- All done, skip attempt at compile time determination of result
5239 --------------------------------
5240 -- Expand_N_Indexed_Component --
5241 --------------------------------
5243 procedure Expand_N_Indexed_Component (N : Node_Id) is
5244 Loc : constant Source_Ptr := Sloc (N);
5245 Typ : constant Entity_Id := Etype (N);
5246 P : constant Node_Id := Prefix (N);
5247 T : constant Entity_Id := Etype (P);
5250 -- A special optimization, if we have an indexed component that is
5251 -- selecting from a slice, then we can eliminate the slice, since, for
5252 -- example, x (i .. j)(k) is identical to x(k). The only difference is
5253 -- the range check required by the slice. The range check for the slice
5254 -- itself has already been generated. The range check for the
5255 -- subscripting operation is ensured by converting the subject to
5256 -- the subtype of the slice.
5258 -- This optimization not only generates better code, avoiding slice
5259 -- messing especially in the packed case, but more importantly bypasses
5260 -- some problems in handling this peculiar case, for example, the issue
5261 -- of dealing specially with object renamings.
5263 if Nkind (P) = N_Slice then
5265 Make_Indexed_Component (Loc,
5266 Prefix => Prefix (P),
5267 Expressions => New_List (
5269 (Etype (First_Index (Etype (P))),
5270 First (Expressions (N))))));
5271 Analyze_And_Resolve (N, Typ);
5275 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
5276 -- function, then additional actuals must be passed.
5278 if Ada_Version >= Ada_2005
5279 and then Is_Build_In_Place_Function_Call (P)
5281 Make_Build_In_Place_Call_In_Anonymous_Context (P);
5284 -- If the prefix is an access type, then we unconditionally rewrite if
5285 -- as an explicit dereference. This simplifies processing for several
5286 -- cases, including packed array cases and certain cases in which checks
5287 -- must be generated. We used to try to do this only when it was
5288 -- necessary, but it cleans up the code to do it all the time.
5290 if Is_Access_Type (T) then
5291 Insert_Explicit_Dereference (P);
5292 Analyze_And_Resolve (P, Designated_Type (T));
5295 -- Generate index and validity checks
5297 Generate_Index_Checks (N);
5299 if Validity_Checks_On and then Validity_Check_Subscripts then
5300 Apply_Subscript_Validity_Checks (N);
5303 -- All done for the non-packed case
5305 if not Is_Packed (Etype (Prefix (N))) then
5309 -- For packed arrays that are not bit-packed (i.e. the case of an array
5310 -- with one or more index types with a non-contiguous enumeration type),
5311 -- we can always use the normal packed element get circuit.
5313 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
5314 Expand_Packed_Element_Reference (N);
5318 -- For a reference to a component of a bit packed array, we have to
5319 -- convert it to a reference to the corresponding Packed_Array_Type.
5320 -- We only want to do this for simple references, and not for:
5322 -- Left side of assignment, or prefix of left side of assignment, or
5323 -- prefix of the prefix, to handle packed arrays of packed arrays,
5324 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
5326 -- Renaming objects in renaming associations
5327 -- This case is handled when a use of the renamed variable occurs
5329 -- Actual parameters for a procedure call
5330 -- This case is handled in Exp_Ch6.Expand_Actuals
5332 -- The second expression in a 'Read attribute reference
5334 -- The prefix of an address or bit or size attribute reference
5336 -- The following circuit detects these exceptions
5339 Child : Node_Id := N;
5340 Parnt : Node_Id := Parent (N);
5344 if Nkind (Parnt) = N_Unchecked_Expression then
5347 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
5348 N_Procedure_Call_Statement)
5349 or else (Nkind (Parnt) = N_Parameter_Association
5351 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
5355 elsif Nkind (Parnt) = N_Attribute_Reference
5356 and then (Attribute_Name (Parnt) = Name_Address
5358 Attribute_Name (Parnt) = Name_Bit
5360 Attribute_Name (Parnt) = Name_Size)
5361 and then Prefix (Parnt) = Child
5365 elsif Nkind (Parnt) = N_Assignment_Statement
5366 and then Name (Parnt) = Child
5370 -- If the expression is an index of an indexed component, it must
5371 -- be expanded regardless of context.
5373 elsif Nkind (Parnt) = N_Indexed_Component
5374 and then Child /= Prefix (Parnt)
5376 Expand_Packed_Element_Reference (N);
5379 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
5380 and then Name (Parent (Parnt)) = Parnt
5384 elsif Nkind (Parnt) = N_Attribute_Reference
5385 and then Attribute_Name (Parnt) = Name_Read
5386 and then Next (First (Expressions (Parnt))) = Child
5390 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
5391 and then Prefix (Parnt) = Child
5396 Expand_Packed_Element_Reference (N);
5400 -- Keep looking up tree for unchecked expression, or if we are the
5401 -- prefix of a possible assignment left side.
5404 Parnt := Parent (Child);
5407 end Expand_N_Indexed_Component;
5409 ---------------------
5410 -- Expand_N_Not_In --
5411 ---------------------
5413 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
5414 -- can be done. This avoids needing to duplicate this expansion code.
5416 procedure Expand_N_Not_In (N : Node_Id) is
5417 Loc : constant Source_Ptr := Sloc (N);
5418 Typ : constant Entity_Id := Etype (N);
5419 Cfs : constant Boolean := Comes_From_Source (N);
5426 Left_Opnd => Left_Opnd (N),
5427 Right_Opnd => Right_Opnd (N))));
5429 -- If this is a set membership, preserve list of alternatives
5431 Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
5433 -- We want this to appear as coming from source if original does (see
5434 -- transformations in Expand_N_In).
5436 Set_Comes_From_Source (N, Cfs);
5437 Set_Comes_From_Source (Right_Opnd (N), Cfs);
5439 -- Now analyze transformed node
5441 Analyze_And_Resolve (N, Typ);
5442 end Expand_N_Not_In;
5448 -- The only replacement required is for the case of a null of a type that
5449 -- is an access to protected subprogram, or a subtype thereof. We represent
5450 -- such access values as a record, and so we must replace the occurrence of
5451 -- null by the equivalent record (with a null address and a null pointer in
5452 -- it), so that the backend creates the proper value.
5454 procedure Expand_N_Null (N : Node_Id) is
5455 Loc : constant Source_Ptr := Sloc (N);
5456 Typ : constant Entity_Id := Base_Type (Etype (N));
5460 if Is_Access_Protected_Subprogram_Type (Typ) then
5462 Make_Aggregate (Loc,
5463 Expressions => New_List (
5464 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
5468 Analyze_And_Resolve (N, Equivalent_Type (Typ));
5470 -- For subsequent semantic analysis, the node must retain its type.
5471 -- Gigi in any case replaces this type by the corresponding record
5472 -- type before processing the node.
5478 when RE_Not_Available =>
5482 ---------------------
5483 -- Expand_N_Op_Abs --
5484 ---------------------
5486 procedure Expand_N_Op_Abs (N : Node_Id) is
5487 Loc : constant Source_Ptr := Sloc (N);
5488 Expr : constant Node_Id := Right_Opnd (N);
5491 Unary_Op_Validity_Checks (N);
5493 -- Deal with software overflow checking
5495 if not Backend_Overflow_Checks_On_Target
5496 and then Is_Signed_Integer_Type (Etype (N))
5497 and then Do_Overflow_Check (N)
5499 -- The only case to worry about is when the argument is equal to the
5500 -- largest negative number, so what we do is to insert the check:
5502 -- [constraint_error when Expr = typ'Base'First]
5504 -- with the usual Duplicate_Subexpr use coding for expr
5507 Make_Raise_Constraint_Error (Loc,
5510 Left_Opnd => Duplicate_Subexpr (Expr),
5512 Make_Attribute_Reference (Loc,
5514 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
5515 Attribute_Name => Name_First)),
5516 Reason => CE_Overflow_Check_Failed));
5519 -- Vax floating-point types case
5521 if Vax_Float (Etype (N)) then
5522 Expand_Vax_Arith (N);
5524 end Expand_N_Op_Abs;
5526 ---------------------
5527 -- Expand_N_Op_Add --
5528 ---------------------
5530 procedure Expand_N_Op_Add (N : Node_Id) is
5531 Typ : constant Entity_Id := Etype (N);
5534 Binary_Op_Validity_Checks (N);
5536 -- N + 0 = 0 + N = N for integer types
5538 if Is_Integer_Type (Typ) then
5539 if Compile_Time_Known_Value (Right_Opnd (N))
5540 and then Expr_Value (Right_Opnd (N)) = Uint_0
5542 Rewrite (N, Left_Opnd (N));
5545 elsif Compile_Time_Known_Value (Left_Opnd (N))
5546 and then Expr_Value (Left_Opnd (N)) = Uint_0
5548 Rewrite (N, Right_Opnd (N));
5553 -- Arithmetic overflow checks for signed integer/fixed point types
5555 if Is_Signed_Integer_Type (Typ)
5556 or else Is_Fixed_Point_Type (Typ)
5558 Apply_Arithmetic_Overflow_Check (N);
5561 -- Vax floating-point types case
5563 elsif Vax_Float (Typ) then
5564 Expand_Vax_Arith (N);
5566 end Expand_N_Op_Add;
5568 ---------------------
5569 -- Expand_N_Op_And --
5570 ---------------------
5572 procedure Expand_N_Op_And (N : Node_Id) is
5573 Typ : constant Entity_Id := Etype (N);
5576 Binary_Op_Validity_Checks (N);
5578 if Is_Array_Type (Etype (N)) then
5579 Expand_Boolean_Operator (N);
5581 elsif Is_Boolean_Type (Etype (N)) then
5582 Adjust_Condition (Left_Opnd (N));
5583 Adjust_Condition (Right_Opnd (N));
5584 Set_Etype (N, Standard_Boolean);
5585 Adjust_Result_Type (N, Typ);
5587 elsif Is_Intrinsic_Subprogram (Entity (N)) then
5588 Expand_Intrinsic_Call (N, Entity (N));
5591 end Expand_N_Op_And;
5593 ------------------------
5594 -- Expand_N_Op_Concat --
5595 ------------------------
5597 procedure Expand_N_Op_Concat (N : Node_Id) is
5599 -- List of operands to be concatenated
5602 -- Node which is to be replaced by the result of concatenating the nodes
5603 -- in the list Opnds.
5606 -- Ensure validity of both operands
5608 Binary_Op_Validity_Checks (N);
5610 -- If we are the left operand of a concatenation higher up the tree,
5611 -- then do nothing for now, since we want to deal with a series of
5612 -- concatenations as a unit.
5614 if Nkind (Parent (N)) = N_Op_Concat
5615 and then N = Left_Opnd (Parent (N))
5620 -- We get here with a concatenation whose left operand may be a
5621 -- concatenation itself with a consistent type. We need to process
5622 -- these concatenation operands from left to right, which means
5623 -- from the deepest node in the tree to the highest node.
5626 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
5627 Cnode := Left_Opnd (Cnode);
5630 -- Now Cnode is the deepest concatenation, and its parents are the
5631 -- concatenation nodes above, so now we process bottom up, doing the
5632 -- operations. We gather a string that is as long as possible up to five
5635 -- The outer loop runs more than once if more than one concatenation
5636 -- type is involved.
5639 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
5640 Set_Parent (Opnds, N);
5642 -- The inner loop gathers concatenation operands
5644 Inner : while Cnode /= N
5645 and then Base_Type (Etype (Cnode)) =
5646 Base_Type (Etype (Parent (Cnode)))
5648 Cnode := Parent (Cnode);
5649 Append (Right_Opnd (Cnode), Opnds);
5652 Expand_Concatenate (Cnode, Opnds);
5654 exit Outer when Cnode = N;
5655 Cnode := Parent (Cnode);
5657 end Expand_N_Op_Concat;
5659 ------------------------
5660 -- Expand_N_Op_Divide --
5661 ------------------------
5663 procedure Expand_N_Op_Divide (N : Node_Id) is
5664 Loc : constant Source_Ptr := Sloc (N);
5665 Lopnd : constant Node_Id := Left_Opnd (N);
5666 Ropnd : constant Node_Id := Right_Opnd (N);
5667 Ltyp : constant Entity_Id := Etype (Lopnd);
5668 Rtyp : constant Entity_Id := Etype (Ropnd);
5669 Typ : Entity_Id := Etype (N);
5670 Rknow : constant Boolean := Is_Integer_Type (Typ)
5672 Compile_Time_Known_Value (Ropnd);
5676 Binary_Op_Validity_Checks (N);
5679 Rval := Expr_Value (Ropnd);
5682 -- N / 1 = N for integer types
5684 if Rknow and then Rval = Uint_1 then
5689 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
5690 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5691 -- operand is an unsigned integer, as required for this to work.
5693 if Nkind (Ropnd) = N_Op_Expon
5694 and then Is_Power_Of_2_For_Shift (Ropnd)
5696 -- We cannot do this transformation in configurable run time mode if we
5697 -- have 64-bit integers and long shifts are not available.
5701 or else Support_Long_Shifts_On_Target)
5704 Make_Op_Shift_Right (Loc,
5707 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
5708 Analyze_And_Resolve (N, Typ);
5712 -- Do required fixup of universal fixed operation
5714 if Typ = Universal_Fixed then
5715 Fixup_Universal_Fixed_Operation (N);
5719 -- Divisions with fixed-point results
5721 if Is_Fixed_Point_Type (Typ) then
5723 -- No special processing if Treat_Fixed_As_Integer is set, since
5724 -- from a semantic point of view such operations are simply integer
5725 -- operations and will be treated that way.
5727 if not Treat_Fixed_As_Integer (N) then
5728 if Is_Integer_Type (Rtyp) then
5729 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
5731 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
5735 -- Other cases of division of fixed-point operands. Again we exclude the
5736 -- case where Treat_Fixed_As_Integer is set.
5738 elsif (Is_Fixed_Point_Type (Ltyp) or else
5739 Is_Fixed_Point_Type (Rtyp))
5740 and then not Treat_Fixed_As_Integer (N)
5742 if Is_Integer_Type (Typ) then
5743 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
5745 pragma Assert (Is_Floating_Point_Type (Typ));
5746 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
5749 -- Mixed-mode operations can appear in a non-static universal context,
5750 -- in which case the integer argument must be converted explicitly.
5752 elsif Typ = Universal_Real
5753 and then Is_Integer_Type (Rtyp)
5756 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
5758 Analyze_And_Resolve (Ropnd, Universal_Real);
5760 elsif Typ = Universal_Real
5761 and then Is_Integer_Type (Ltyp)
5764 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
5766 Analyze_And_Resolve (Lopnd, Universal_Real);
5768 -- Non-fixed point cases, do integer zero divide and overflow checks
5770 elsif Is_Integer_Type (Typ) then
5771 Apply_Divide_Check (N);
5773 -- Deal with Vax_Float
5775 elsif Vax_Float (Typ) then
5776 Expand_Vax_Arith (N);
5779 end Expand_N_Op_Divide;
5781 --------------------
5782 -- Expand_N_Op_Eq --
5783 --------------------
5785 procedure Expand_N_Op_Eq (N : Node_Id) is
5786 Loc : constant Source_Ptr := Sloc (N);
5787 Typ : constant Entity_Id := Etype (N);
5788 Lhs : constant Node_Id := Left_Opnd (N);
5789 Rhs : constant Node_Id := Right_Opnd (N);
5790 Bodies : constant List_Id := New_List;
5791 A_Typ : constant Entity_Id := Etype (Lhs);
5793 Typl : Entity_Id := A_Typ;
5794 Op_Name : Entity_Id;
5797 procedure Build_Equality_Call (Eq : Entity_Id);
5798 -- If a constructed equality exists for the type or for its parent,
5799 -- build and analyze call, adding conversions if the operation is
5802 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
5803 -- Determines whether a type has a subcomponent of an unconstrained
5804 -- Unchecked_Union subtype. Typ is a record type.
5806 -------------------------
5807 -- Build_Equality_Call --
5808 -------------------------
5810 procedure Build_Equality_Call (Eq : Entity_Id) is
5811 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
5812 L_Exp : Node_Id := Relocate_Node (Lhs);
5813 R_Exp : Node_Id := Relocate_Node (Rhs);
5816 if Base_Type (Op_Type) /= Base_Type (A_Typ)
5817 and then not Is_Class_Wide_Type (A_Typ)
5819 L_Exp := OK_Convert_To (Op_Type, L_Exp);
5820 R_Exp := OK_Convert_To (Op_Type, R_Exp);
5823 -- If we have an Unchecked_Union, we need to add the inferred
5824 -- discriminant values as actuals in the function call. At this
5825 -- point, the expansion has determined that both operands have
5826 -- inferable discriminants.
5828 if Is_Unchecked_Union (Op_Type) then
5830 Lhs_Type : constant Node_Id := Etype (L_Exp);
5831 Rhs_Type : constant Node_Id := Etype (R_Exp);
5832 Lhs_Discr_Val : Node_Id;
5833 Rhs_Discr_Val : Node_Id;
5836 -- Per-object constrained selected components require special
5837 -- attention. If the enclosing scope of the component is an
5838 -- Unchecked_Union, we cannot reference its discriminants
5839 -- directly. This is why we use the two extra parameters of
5840 -- the equality function of the enclosing Unchecked_Union.
5842 -- type UU_Type (Discr : Integer := 0) is
5845 -- pragma Unchecked_Union (UU_Type);
5847 -- 1. Unchecked_Union enclosing record:
5849 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
5851 -- Comp : UU_Type (Discr);
5853 -- end Enclosing_UU_Type;
5854 -- pragma Unchecked_Union (Enclosing_UU_Type);
5856 -- Obj1 : Enclosing_UU_Type;
5857 -- Obj2 : Enclosing_UU_Type (1);
5859 -- [. . .] Obj1 = Obj2 [. . .]
5863 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
5865 -- A and B are the formal parameters of the equality function
5866 -- of Enclosing_UU_Type. The function always has two extra
5867 -- formals to capture the inferred discriminant values.
5869 -- 2. Non-Unchecked_Union enclosing record:
5872 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
5875 -- Comp : UU_Type (Discr);
5877 -- end Enclosing_Non_UU_Type;
5879 -- Obj1 : Enclosing_Non_UU_Type;
5880 -- Obj2 : Enclosing_Non_UU_Type (1);
5882 -- ... Obj1 = Obj2 ...
5886 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
5887 -- obj1.discr, obj2.discr)) then
5889 -- In this case we can directly reference the discriminants of
5890 -- the enclosing record.
5894 if Nkind (Lhs) = N_Selected_Component
5895 and then Has_Per_Object_Constraint
5896 (Entity (Selector_Name (Lhs)))
5898 -- Enclosing record is an Unchecked_Union, use formal A
5900 if Is_Unchecked_Union
5901 (Scope (Entity (Selector_Name (Lhs))))
5903 Lhs_Discr_Val := Make_Identifier (Loc, Name_A);
5905 -- Enclosing record is of a non-Unchecked_Union type, it is
5906 -- possible to reference the discriminant.
5910 Make_Selected_Component (Loc,
5911 Prefix => Prefix (Lhs),
5914 (Get_Discriminant_Value
5915 (First_Discriminant (Lhs_Type),
5917 Stored_Constraint (Lhs_Type))));
5920 -- Comment needed here ???
5923 -- Infer the discriminant value
5927 (Get_Discriminant_Value
5928 (First_Discriminant (Lhs_Type),
5930 Stored_Constraint (Lhs_Type)));
5935 if Nkind (Rhs) = N_Selected_Component
5936 and then Has_Per_Object_Constraint
5937 (Entity (Selector_Name (Rhs)))
5939 if Is_Unchecked_Union
5940 (Scope (Entity (Selector_Name (Rhs))))
5942 Rhs_Discr_Val := Make_Identifier (Loc, Name_B);
5946 Make_Selected_Component (Loc,
5947 Prefix => Prefix (Rhs),
5949 New_Copy (Get_Discriminant_Value (
5950 First_Discriminant (Rhs_Type),
5952 Stored_Constraint (Rhs_Type))));
5957 New_Copy (Get_Discriminant_Value (
5958 First_Discriminant (Rhs_Type),
5960 Stored_Constraint (Rhs_Type)));
5965 Make_Function_Call (Loc,
5966 Name => New_Reference_To (Eq, Loc),
5967 Parameter_Associations => New_List (
5974 -- Normal case, not an unchecked union
5978 Make_Function_Call (Loc,
5979 Name => New_Reference_To (Eq, Loc),
5980 Parameter_Associations => New_List (L_Exp, R_Exp)));
5983 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5984 end Build_Equality_Call;
5986 ------------------------------------
5987 -- Has_Unconstrained_UU_Component --
5988 ------------------------------------
5990 function Has_Unconstrained_UU_Component
5991 (Typ : Node_Id) return Boolean
5993 Tdef : constant Node_Id :=
5994 Type_Definition (Declaration_Node (Base_Type (Typ)));
5998 function Component_Is_Unconstrained_UU
5999 (Comp : Node_Id) return Boolean;
6000 -- Determines whether the subtype of the component is an
6001 -- unconstrained Unchecked_Union.
6003 function Variant_Is_Unconstrained_UU
6004 (Variant : Node_Id) return Boolean;
6005 -- Determines whether a component of the variant has an unconstrained
6006 -- Unchecked_Union subtype.
6008 -----------------------------------
6009 -- Component_Is_Unconstrained_UU --
6010 -----------------------------------
6012 function Component_Is_Unconstrained_UU
6013 (Comp : Node_Id) return Boolean
6016 if Nkind (Comp) /= N_Component_Declaration then
6021 Sindic : constant Node_Id :=
6022 Subtype_Indication (Component_Definition (Comp));
6025 -- Unconstrained nominal type. In the case of a constraint
6026 -- present, the node kind would have been N_Subtype_Indication.
6028 if Nkind (Sindic) = N_Identifier then
6029 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
6034 end Component_Is_Unconstrained_UU;
6036 ---------------------------------
6037 -- Variant_Is_Unconstrained_UU --
6038 ---------------------------------
6040 function Variant_Is_Unconstrained_UU
6041 (Variant : Node_Id) return Boolean
6043 Clist : constant Node_Id := Component_List (Variant);
6046 if Is_Empty_List (Component_Items (Clist)) then
6050 -- We only need to test one component
6053 Comp : Node_Id := First (Component_Items (Clist));
6056 while Present (Comp) loop
6057 if Component_Is_Unconstrained_UU (Comp) then
6065 -- None of the components withing the variant were of
6066 -- unconstrained Unchecked_Union type.
6069 end Variant_Is_Unconstrained_UU;
6071 -- Start of processing for Has_Unconstrained_UU_Component
6074 if Null_Present (Tdef) then
6078 Clist := Component_List (Tdef);
6079 Vpart := Variant_Part (Clist);
6081 -- Inspect available components
6083 if Present (Component_Items (Clist)) then
6085 Comp : Node_Id := First (Component_Items (Clist));
6088 while Present (Comp) loop
6090 -- One component is sufficient
6092 if Component_Is_Unconstrained_UU (Comp) then
6101 -- Inspect available components withing variants
6103 if Present (Vpart) then
6105 Variant : Node_Id := First (Variants (Vpart));
6108 while Present (Variant) loop
6110 -- One component within a variant is sufficient
6112 if Variant_Is_Unconstrained_UU (Variant) then
6121 -- Neither the available components, nor the components inside the
6122 -- variant parts were of an unconstrained Unchecked_Union subtype.
6125 end Has_Unconstrained_UU_Component;
6127 -- Start of processing for Expand_N_Op_Eq
6130 Binary_Op_Validity_Checks (N);
6132 if Ekind (Typl) = E_Private_Type then
6133 Typl := Underlying_Type (Typl);
6134 elsif Ekind (Typl) = E_Private_Subtype then
6135 Typl := Underlying_Type (Base_Type (Typl));
6140 -- It may happen in error situations that the underlying type is not
6141 -- set. The error will be detected later, here we just defend the
6148 Typl := Base_Type (Typl);
6150 -- Boolean types (requiring handling of non-standard case)
6152 if Is_Boolean_Type (Typl) then
6153 Adjust_Condition (Left_Opnd (N));
6154 Adjust_Condition (Right_Opnd (N));
6155 Set_Etype (N, Standard_Boolean);
6156 Adjust_Result_Type (N, Typ);
6160 elsif Is_Array_Type (Typl) then
6162 -- If we are doing full validity checking, and it is possible for the
6163 -- array elements to be invalid then expand out array comparisons to
6164 -- make sure that we check the array elements.
6166 if Validity_Check_Operands
6167 and then not Is_Known_Valid (Component_Type (Typl))
6170 Save_Force_Validity_Checks : constant Boolean :=
6171 Force_Validity_Checks;
6173 Force_Validity_Checks := True;
6175 Expand_Array_Equality
6177 Relocate_Node (Lhs),
6178 Relocate_Node (Rhs),
6181 Insert_Actions (N, Bodies);
6182 Analyze_And_Resolve (N, Standard_Boolean);
6183 Force_Validity_Checks := Save_Force_Validity_Checks;
6186 -- Packed case where both operands are known aligned
6188 elsif Is_Bit_Packed_Array (Typl)
6189 and then not Is_Possibly_Unaligned_Object (Lhs)
6190 and then not Is_Possibly_Unaligned_Object (Rhs)
6192 Expand_Packed_Eq (N);
6194 -- Where the component type is elementary we can use a block bit
6195 -- comparison (if supported on the target) exception in the case
6196 -- of floating-point (negative zero issues require element by
6197 -- element comparison), and atomic types (where we must be sure
6198 -- to load elements independently) and possibly unaligned arrays.
6200 elsif Is_Elementary_Type (Component_Type (Typl))
6201 and then not Is_Floating_Point_Type (Component_Type (Typl))
6202 and then not Is_Atomic (Component_Type (Typl))
6203 and then not Is_Possibly_Unaligned_Object (Lhs)
6204 and then not Is_Possibly_Unaligned_Object (Rhs)
6205 and then Support_Composite_Compare_On_Target
6209 -- For composite and floating-point cases, expand equality loop to
6210 -- make sure of using proper comparisons for tagged types, and
6211 -- correctly handling the floating-point case.
6215 Expand_Array_Equality
6217 Relocate_Node (Lhs),
6218 Relocate_Node (Rhs),
6221 Insert_Actions (N, Bodies, Suppress => All_Checks);
6222 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6227 elsif Is_Record_Type (Typl) then
6229 -- For tagged types, use the primitive "="
6231 if Is_Tagged_Type (Typl) then
6233 -- No need to do anything else compiling under restriction
6234 -- No_Dispatching_Calls. During the semantic analysis we
6235 -- already notified such violation.
6237 if Restriction_Active (No_Dispatching_Calls) then
6241 -- If this is derived from an untagged private type completed with
6242 -- a tagged type, it does not have a full view, so we use the
6243 -- primitive operations of the private type. This check should no
6244 -- longer be necessary when these types get their full views???
6246 if Is_Private_Type (A_Typ)
6247 and then not Is_Tagged_Type (A_Typ)
6248 and then Is_Derived_Type (A_Typ)
6249 and then No (Full_View (A_Typ))
6251 -- Search for equality operation, checking that the operands
6252 -- have the same type. Note that we must find a matching entry,
6253 -- or something is very wrong!
6255 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
6257 while Present (Prim) loop
6258 exit when Chars (Node (Prim)) = Name_Op_Eq
6259 and then Etype (First_Formal (Node (Prim))) =
6260 Etype (Next_Formal (First_Formal (Node (Prim))))
6262 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6267 pragma Assert (Present (Prim));
6268 Op_Name := Node (Prim);
6270 -- Find the type's predefined equality or an overriding
6271 -- user- defined equality. The reason for not simply calling
6272 -- Find_Prim_Op here is that there may be a user-defined
6273 -- overloaded equality op that precedes the equality that we want,
6274 -- so we have to explicitly search (e.g., there could be an
6275 -- equality with two different parameter types).
6278 if Is_Class_Wide_Type (Typl) then
6279 Typl := Root_Type (Typl);
6282 Prim := First_Elmt (Primitive_Operations (Typl));
6283 while Present (Prim) loop
6284 exit when Chars (Node (Prim)) = Name_Op_Eq
6285 and then Etype (First_Formal (Node (Prim))) =
6286 Etype (Next_Formal (First_Formal (Node (Prim))))
6288 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6293 pragma Assert (Present (Prim));
6294 Op_Name := Node (Prim);
6297 Build_Equality_Call (Op_Name);
6299 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
6300 -- predefined equality operator for a type which has a subcomponent
6301 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
6303 elsif Has_Unconstrained_UU_Component (Typl) then
6305 Make_Raise_Program_Error (Loc,
6306 Reason => PE_Unchecked_Union_Restriction));
6308 -- Prevent Gigi from generating incorrect code by rewriting the
6309 -- equality as a standard False.
6312 New_Occurrence_Of (Standard_False, Loc));
6314 elsif Is_Unchecked_Union (Typl) then
6316 -- If we can infer the discriminants of the operands, we make a
6317 -- call to the TSS equality function.
6319 if Has_Inferable_Discriminants (Lhs)
6321 Has_Inferable_Discriminants (Rhs)
6324 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6327 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
6328 -- the predefined equality operator for an Unchecked_Union type
6329 -- if either of the operands lack inferable discriminants.
6332 Make_Raise_Program_Error (Loc,
6333 Reason => PE_Unchecked_Union_Restriction));
6335 -- Prevent Gigi from generating incorrect code by rewriting
6336 -- the equality as a standard False.
6339 New_Occurrence_Of (Standard_False, Loc));
6343 -- If a type support function is present (for complex cases), use it
6345 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
6347 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6349 -- Otherwise expand the component by component equality. Note that
6350 -- we never use block-bit comparisons for records, because of the
6351 -- problems with gaps. The backend will often be able to recombine
6352 -- the separate comparisons that we generate here.
6355 Remove_Side_Effects (Lhs);
6356 Remove_Side_Effects (Rhs);
6358 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
6360 Insert_Actions (N, Bodies, Suppress => All_Checks);
6361 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6365 -- Test if result is known at compile time
6367 Rewrite_Comparison (N);
6369 -- If we still have comparison for Vax_Float, process it
6371 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
6372 Expand_Vax_Comparison (N);
6376 Optimize_Length_Comparison (N);
6379 -----------------------
6380 -- Expand_N_Op_Expon --
6381 -----------------------
6383 procedure Expand_N_Op_Expon (N : Node_Id) is
6384 Loc : constant Source_Ptr := Sloc (N);
6385 Typ : constant Entity_Id := Etype (N);
6386 Rtyp : constant Entity_Id := Root_Type (Typ);
6387 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
6388 Bastyp : constant Node_Id := Etype (Base);
6389 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
6390 Exptyp : constant Entity_Id := Etype (Exp);
6391 Ovflo : constant Boolean := Do_Overflow_Check (N);
6400 Binary_Op_Validity_Checks (N);
6402 -- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node
6404 if CodePeer_Mode or Alfa_Mode then
6408 -- If either operand is of a private type, then we have the use of an
6409 -- intrinsic operator, and we get rid of the privateness, by using root
6410 -- types of underlying types for the actual operation. Otherwise the
6411 -- private types will cause trouble if we expand multiplications or
6412 -- shifts etc. We also do this transformation if the result type is
6413 -- different from the base type.
6415 if Is_Private_Type (Etype (Base))
6416 or else Is_Private_Type (Typ)
6417 or else Is_Private_Type (Exptyp)
6418 or else Rtyp /= Root_Type (Bastyp)
6421 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
6422 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
6426 Unchecked_Convert_To (Typ,
6428 Left_Opnd => Unchecked_Convert_To (Bt, Base),
6429 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
6430 Analyze_And_Resolve (N, Typ);
6435 -- Test for case of known right argument
6437 if Compile_Time_Known_Value (Exp) then
6438 Expv := Expr_Value (Exp);
6440 -- We only fold small non-negative exponents. You might think we
6441 -- could fold small negative exponents for the real case, but we
6442 -- can't because we are required to raise Constraint_Error for
6443 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
6444 -- See ACVC test C4A012B.
6446 if Expv >= 0 and then Expv <= 4 then
6448 -- X ** 0 = 1 (or 1.0)
6452 -- Call Remove_Side_Effects to ensure that any side effects
6453 -- in the ignored left operand (in particular function calls
6454 -- to user defined functions) are properly executed.
6456 Remove_Side_Effects (Base);
6458 if Ekind (Typ) in Integer_Kind then
6459 Xnode := Make_Integer_Literal (Loc, Intval => 1);
6461 Xnode := Make_Real_Literal (Loc, Ureal_1);
6473 Make_Op_Multiply (Loc,
6474 Left_Opnd => Duplicate_Subexpr (Base),
6475 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6477 -- X ** 3 = X * X * X
6481 Make_Op_Multiply (Loc,
6483 Make_Op_Multiply (Loc,
6484 Left_Opnd => Duplicate_Subexpr (Base),
6485 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
6486 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6489 -- En : constant base'type := base * base;
6494 Temp := Make_Temporary (Loc, 'E', Base);
6496 Insert_Actions (N, New_List (
6497 Make_Object_Declaration (Loc,
6498 Defining_Identifier => Temp,
6499 Constant_Present => True,
6500 Object_Definition => New_Reference_To (Typ, Loc),
6502 Make_Op_Multiply (Loc,
6503 Left_Opnd => Duplicate_Subexpr (Base),
6504 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
6507 Make_Op_Multiply (Loc,
6508 Left_Opnd => New_Reference_To (Temp, Loc),
6509 Right_Opnd => New_Reference_To (Temp, Loc));
6513 Analyze_And_Resolve (N, Typ);
6518 -- Case of (2 ** expression) appearing as an argument of an integer
6519 -- multiplication, or as the right argument of a division of a non-
6520 -- negative integer. In such cases we leave the node untouched, setting
6521 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
6522 -- of the higher level node converts it into a shift.
6524 -- Another case is 2 ** N in any other context. We simply convert
6525 -- this to 1 * 2 ** N, and then the above transformation applies.
6527 -- Note: this transformation is not applicable for a modular type with
6528 -- a non-binary modulus in the multiplication case, since we get a wrong
6529 -- result if the shift causes an overflow before the modular reduction.
6531 if Nkind (Base) = N_Integer_Literal
6532 and then Intval (Base) = 2
6533 and then Is_Integer_Type (Root_Type (Exptyp))
6534 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
6535 and then Is_Unsigned_Type (Exptyp)
6538 -- First the multiply and divide cases
6540 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
6542 P : constant Node_Id := Parent (N);
6543 L : constant Node_Id := Left_Opnd (P);
6544 R : constant Node_Id := Right_Opnd (P);
6547 if (Nkind (P) = N_Op_Multiply
6548 and then not Non_Binary_Modulus (Typ)
6550 ((Is_Integer_Type (Etype (L)) and then R = N)
6552 (Is_Integer_Type (Etype (R)) and then L = N))
6553 and then not Do_Overflow_Check (P))
6555 (Nkind (P) = N_Op_Divide
6556 and then Is_Integer_Type (Etype (L))
6557 and then Is_Unsigned_Type (Etype (L))
6559 and then not Do_Overflow_Check (P))
6561 Set_Is_Power_Of_2_For_Shift (N);
6566 -- Now the other cases
6568 elsif not Non_Binary_Modulus (Typ) then
6570 Make_Op_Multiply (Loc,
6571 Left_Opnd => Make_Integer_Literal (Loc, 1),
6572 Right_Opnd => Relocate_Node (N)));
6573 Analyze_And_Resolve (N, Typ);
6578 -- Fall through if exponentiation must be done using a runtime routine
6580 -- First deal with modular case
6582 if Is_Modular_Integer_Type (Rtyp) then
6584 -- Non-binary case, we call the special exponentiation routine for
6585 -- the non-binary case, converting the argument to Long_Long_Integer
6586 -- and passing the modulus value. Then the result is converted back
6587 -- to the base type.
6589 if Non_Binary_Modulus (Rtyp) then
6592 Make_Function_Call (Loc,
6593 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
6594 Parameter_Associations => New_List (
6595 Convert_To (Standard_Integer, Base),
6596 Make_Integer_Literal (Loc, Modulus (Rtyp)),
6599 -- Binary case, in this case, we call one of two routines, either the
6600 -- unsigned integer case, or the unsigned long long integer case,
6601 -- with a final "and" operation to do the required mod.
6604 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
6605 Ent := RTE (RE_Exp_Unsigned);
6607 Ent := RTE (RE_Exp_Long_Long_Unsigned);
6614 Make_Function_Call (Loc,
6615 Name => New_Reference_To (Ent, Loc),
6616 Parameter_Associations => New_List (
6617 Convert_To (Etype (First_Formal (Ent)), Base),
6620 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
6624 -- Common exit point for modular type case
6626 Analyze_And_Resolve (N, Typ);
6629 -- Signed integer cases, done using either Integer or Long_Long_Integer.
6630 -- It is not worth having routines for Short_[Short_]Integer, since for
6631 -- most machines it would not help, and it would generate more code that
6632 -- might need certification when a certified run time is required.
6634 -- In the integer cases, we have two routines, one for when overflow
6635 -- checks are required, and one when they are not required, since there
6636 -- is a real gain in omitting checks on many machines.
6638 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
6639 or else (Rtyp = Base_Type (Standard_Long_Integer)
6641 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
6642 or else (Rtyp = Universal_Integer)
6644 Etyp := Standard_Long_Long_Integer;
6647 Rent := RE_Exp_Long_Long_Integer;
6649 Rent := RE_Exn_Long_Long_Integer;
6652 elsif Is_Signed_Integer_Type (Rtyp) then
6653 Etyp := Standard_Integer;
6656 Rent := RE_Exp_Integer;
6658 Rent := RE_Exn_Integer;
6661 -- Floating-point cases, always done using Long_Long_Float. We do not
6662 -- need separate routines for the overflow case here, since in the case
6663 -- of floating-point, we generate infinities anyway as a rule (either
6664 -- that or we automatically trap overflow), and if there is an infinity
6665 -- generated and a range check is required, the check will fail anyway.
6668 pragma Assert (Is_Floating_Point_Type (Rtyp));
6669 Etyp := Standard_Long_Long_Float;
6670 Rent := RE_Exn_Long_Long_Float;
6673 -- Common processing for integer cases and floating-point cases.
6674 -- If we are in the right type, we can call runtime routine directly
6677 and then Rtyp /= Universal_Integer
6678 and then Rtyp /= Universal_Real
6681 Make_Function_Call (Loc,
6682 Name => New_Reference_To (RTE (Rent), Loc),
6683 Parameter_Associations => New_List (Base, Exp)));
6685 -- Otherwise we have to introduce conversions (conversions are also
6686 -- required in the universal cases, since the runtime routine is
6687 -- typed using one of the standard types).
6692 Make_Function_Call (Loc,
6693 Name => New_Reference_To (RTE (Rent), Loc),
6694 Parameter_Associations => New_List (
6695 Convert_To (Etyp, Base),
6699 Analyze_And_Resolve (N, Typ);
6703 when RE_Not_Available =>
6705 end Expand_N_Op_Expon;
6707 --------------------
6708 -- Expand_N_Op_Ge --
6709 --------------------
6711 procedure Expand_N_Op_Ge (N : Node_Id) is
6712 Typ : constant Entity_Id := Etype (N);
6713 Op1 : constant Node_Id := Left_Opnd (N);
6714 Op2 : constant Node_Id := Right_Opnd (N);
6715 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6718 Binary_Op_Validity_Checks (N);
6720 if Is_Array_Type (Typ1) then
6721 Expand_Array_Comparison (N);
6725 if Is_Boolean_Type (Typ1) then
6726 Adjust_Condition (Op1);
6727 Adjust_Condition (Op2);
6728 Set_Etype (N, Standard_Boolean);
6729 Adjust_Result_Type (N, Typ);
6732 Rewrite_Comparison (N);
6734 -- If we still have comparison, and Vax_Float type, process it
6736 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6737 Expand_Vax_Comparison (N);
6741 Optimize_Length_Comparison (N);
6744 --------------------
6745 -- Expand_N_Op_Gt --
6746 --------------------
6748 procedure Expand_N_Op_Gt (N : Node_Id) is
6749 Typ : constant Entity_Id := Etype (N);
6750 Op1 : constant Node_Id := Left_Opnd (N);
6751 Op2 : constant Node_Id := Right_Opnd (N);
6752 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6755 Binary_Op_Validity_Checks (N);
6757 if Is_Array_Type (Typ1) then
6758 Expand_Array_Comparison (N);
6762 if Is_Boolean_Type (Typ1) then
6763 Adjust_Condition (Op1);
6764 Adjust_Condition (Op2);
6765 Set_Etype (N, Standard_Boolean);
6766 Adjust_Result_Type (N, Typ);
6769 Rewrite_Comparison (N);
6771 -- If we still have comparison, and Vax_Float type, process it
6773 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6774 Expand_Vax_Comparison (N);
6778 Optimize_Length_Comparison (N);
6781 --------------------
6782 -- Expand_N_Op_Le --
6783 --------------------
6785 procedure Expand_N_Op_Le (N : Node_Id) is
6786 Typ : constant Entity_Id := Etype (N);
6787 Op1 : constant Node_Id := Left_Opnd (N);
6788 Op2 : constant Node_Id := Right_Opnd (N);
6789 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6792 Binary_Op_Validity_Checks (N);
6794 if Is_Array_Type (Typ1) then
6795 Expand_Array_Comparison (N);
6799 if Is_Boolean_Type (Typ1) then
6800 Adjust_Condition (Op1);
6801 Adjust_Condition (Op2);
6802 Set_Etype (N, Standard_Boolean);
6803 Adjust_Result_Type (N, Typ);
6806 Rewrite_Comparison (N);
6808 -- If we still have comparison, and Vax_Float type, process it
6810 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6811 Expand_Vax_Comparison (N);
6815 Optimize_Length_Comparison (N);
6818 --------------------
6819 -- Expand_N_Op_Lt --
6820 --------------------
6822 procedure Expand_N_Op_Lt (N : Node_Id) is
6823 Typ : constant Entity_Id := Etype (N);
6824 Op1 : constant Node_Id := Left_Opnd (N);
6825 Op2 : constant Node_Id := Right_Opnd (N);
6826 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6829 Binary_Op_Validity_Checks (N);
6831 if Is_Array_Type (Typ1) then
6832 Expand_Array_Comparison (N);
6836 if Is_Boolean_Type (Typ1) then
6837 Adjust_Condition (Op1);
6838 Adjust_Condition (Op2);
6839 Set_Etype (N, Standard_Boolean);
6840 Adjust_Result_Type (N, Typ);
6843 Rewrite_Comparison (N);
6845 -- If we still have comparison, and Vax_Float type, process it
6847 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6848 Expand_Vax_Comparison (N);
6852 Optimize_Length_Comparison (N);
6855 -----------------------
6856 -- Expand_N_Op_Minus --
6857 -----------------------
6859 procedure Expand_N_Op_Minus (N : Node_Id) is
6860 Loc : constant Source_Ptr := Sloc (N);
6861 Typ : constant Entity_Id := Etype (N);
6864 Unary_Op_Validity_Checks (N);
6866 if not Backend_Overflow_Checks_On_Target
6867 and then Is_Signed_Integer_Type (Etype (N))
6868 and then Do_Overflow_Check (N)
6870 -- Software overflow checking expands -expr into (0 - expr)
6873 Make_Op_Subtract (Loc,
6874 Left_Opnd => Make_Integer_Literal (Loc, 0),
6875 Right_Opnd => Right_Opnd (N)));
6877 Analyze_And_Resolve (N, Typ);
6879 -- Vax floating-point types case
6881 elsif Vax_Float (Etype (N)) then
6882 Expand_Vax_Arith (N);
6884 end Expand_N_Op_Minus;
6886 ---------------------
6887 -- Expand_N_Op_Mod --
6888 ---------------------
6890 procedure Expand_N_Op_Mod (N : Node_Id) is
6891 Loc : constant Source_Ptr := Sloc (N);
6892 Typ : constant Entity_Id := Etype (N);
6893 Left : constant Node_Id := Left_Opnd (N);
6894 Right : constant Node_Id := Right_Opnd (N);
6895 DOC : constant Boolean := Do_Overflow_Check (N);
6896 DDC : constant Boolean := Do_Division_Check (N);
6906 pragma Warnings (Off, Lhi);
6909 Binary_Op_Validity_Checks (N);
6911 Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
6912 Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
6914 -- Convert mod to rem if operands are known non-negative. We do this
6915 -- since it is quite likely that this will improve the quality of code,
6916 -- (the operation now corresponds to the hardware remainder), and it
6917 -- does not seem likely that it could be harmful.
6919 if LOK and then Llo >= 0
6921 ROK and then Rlo >= 0
6924 Make_Op_Rem (Sloc (N),
6925 Left_Opnd => Left_Opnd (N),
6926 Right_Opnd => Right_Opnd (N)));
6928 -- Instead of reanalyzing the node we do the analysis manually. This
6929 -- avoids anomalies when the replacement is done in an instance and
6930 -- is epsilon more efficient.
6932 Set_Entity (N, Standard_Entity (S_Op_Rem));
6934 Set_Do_Overflow_Check (N, DOC);
6935 Set_Do_Division_Check (N, DDC);
6936 Expand_N_Op_Rem (N);
6939 -- Otherwise, normal mod processing
6942 if Is_Integer_Type (Etype (N)) then
6943 Apply_Divide_Check (N);
6946 -- Apply optimization x mod 1 = 0. We don't really need that with
6947 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
6948 -- certainly harmless.
6950 if Is_Integer_Type (Etype (N))
6951 and then Compile_Time_Known_Value (Right)
6952 and then Expr_Value (Right) = Uint_1
6954 -- Call Remove_Side_Effects to ensure that any side effects in
6955 -- the ignored left operand (in particular function calls to
6956 -- user defined functions) are properly executed.
6958 Remove_Side_Effects (Left);
6960 Rewrite (N, Make_Integer_Literal (Loc, 0));
6961 Analyze_And_Resolve (N, Typ);
6965 -- Deal with annoying case of largest negative number remainder
6966 -- minus one. Gigi does not handle this case correctly, because
6967 -- it generates a divide instruction which may trap in this case.
6969 -- In fact the check is quite easy, if the right operand is -1, then
6970 -- the mod value is always 0, and we can just ignore the left operand
6971 -- completely in this case.
6973 -- The operand type may be private (e.g. in the expansion of an
6974 -- intrinsic operation) so we must use the underlying type to get the
6975 -- bounds, and convert the literals explicitly.
6979 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
6981 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
6983 ((not LOK) or else (Llo = LLB))
6986 Make_Conditional_Expression (Loc,
6987 Expressions => New_List (
6989 Left_Opnd => Duplicate_Subexpr (Right),
6991 Unchecked_Convert_To (Typ,
6992 Make_Integer_Literal (Loc, -1))),
6993 Unchecked_Convert_To (Typ,
6994 Make_Integer_Literal (Loc, Uint_0)),
6995 Relocate_Node (N))));
6997 Set_Analyzed (Next (Next (First (Expressions (N)))));
6998 Analyze_And_Resolve (N, Typ);
7001 end Expand_N_Op_Mod;
7003 --------------------------
7004 -- Expand_N_Op_Multiply --
7005 --------------------------
7007 procedure Expand_N_Op_Multiply (N : Node_Id) is
7008 Loc : constant Source_Ptr := Sloc (N);
7009 Lop : constant Node_Id := Left_Opnd (N);
7010 Rop : constant Node_Id := Right_Opnd (N);
7012 Lp2 : constant Boolean :=
7013 Nkind (Lop) = N_Op_Expon
7014 and then Is_Power_Of_2_For_Shift (Lop);
7016 Rp2 : constant Boolean :=
7017 Nkind (Rop) = N_Op_Expon
7018 and then Is_Power_Of_2_For_Shift (Rop);
7020 Ltyp : constant Entity_Id := Etype (Lop);
7021 Rtyp : constant Entity_Id := Etype (Rop);
7022 Typ : Entity_Id := Etype (N);
7025 Binary_Op_Validity_Checks (N);
7027 -- Special optimizations for integer types
7029 if Is_Integer_Type (Typ) then
7031 -- N * 0 = 0 for integer types
7033 if Compile_Time_Known_Value (Rop)
7034 and then Expr_Value (Rop) = Uint_0
7036 -- Call Remove_Side_Effects to ensure that any side effects in
7037 -- the ignored left operand (in particular function calls to
7038 -- user defined functions) are properly executed.
7040 Remove_Side_Effects (Lop);
7042 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7043 Analyze_And_Resolve (N, Typ);
7047 -- Similar handling for 0 * N = 0
7049 if Compile_Time_Known_Value (Lop)
7050 and then Expr_Value (Lop) = Uint_0
7052 Remove_Side_Effects (Rop);
7053 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7054 Analyze_And_Resolve (N, Typ);
7058 -- N * 1 = 1 * N = N for integer types
7060 -- This optimisation is not done if we are going to
7061 -- rewrite the product 1 * 2 ** N to a shift.
7063 if Compile_Time_Known_Value (Rop)
7064 and then Expr_Value (Rop) = Uint_1
7070 elsif Compile_Time_Known_Value (Lop)
7071 and then Expr_Value (Lop) = Uint_1
7079 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
7080 -- Is_Power_Of_2_For_Shift is set means that we know that our left
7081 -- operand is an integer, as required for this to work.
7086 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
7090 Left_Opnd => Make_Integer_Literal (Loc, 2),
7093 Left_Opnd => Right_Opnd (Lop),
7094 Right_Opnd => Right_Opnd (Rop))));
7095 Analyze_And_Resolve (N, Typ);
7100 Make_Op_Shift_Left (Loc,
7103 Convert_To (Standard_Natural, Right_Opnd (Rop))));
7104 Analyze_And_Resolve (N, Typ);
7108 -- Same processing for the operands the other way round
7112 Make_Op_Shift_Left (Loc,
7115 Convert_To (Standard_Natural, Right_Opnd (Lop))));
7116 Analyze_And_Resolve (N, Typ);
7120 -- Do required fixup of universal fixed operation
7122 if Typ = Universal_Fixed then
7123 Fixup_Universal_Fixed_Operation (N);
7127 -- Multiplications with fixed-point results
7129 if Is_Fixed_Point_Type (Typ) then
7131 -- No special processing if Treat_Fixed_As_Integer is set, since from
7132 -- a semantic point of view such operations are simply integer
7133 -- operations and will be treated that way.
7135 if not Treat_Fixed_As_Integer (N) then
7137 -- Case of fixed * integer => fixed
7139 if Is_Integer_Type (Rtyp) then
7140 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
7142 -- Case of integer * fixed => fixed
7144 elsif Is_Integer_Type (Ltyp) then
7145 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
7147 -- Case of fixed * fixed => fixed
7150 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
7154 -- Other cases of multiplication of fixed-point operands. Again we
7155 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
7157 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
7158 and then not Treat_Fixed_As_Integer (N)
7160 if Is_Integer_Type (Typ) then
7161 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
7163 pragma Assert (Is_Floating_Point_Type (Typ));
7164 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
7167 -- Mixed-mode operations can appear in a non-static universal context,
7168 -- in which case the integer argument must be converted explicitly.
7170 elsif Typ = Universal_Real
7171 and then Is_Integer_Type (Rtyp)
7173 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
7175 Analyze_And_Resolve (Rop, Universal_Real);
7177 elsif Typ = Universal_Real
7178 and then Is_Integer_Type (Ltyp)
7180 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
7182 Analyze_And_Resolve (Lop, Universal_Real);
7184 -- Non-fixed point cases, check software overflow checking required
7186 elsif Is_Signed_Integer_Type (Etype (N)) then
7187 Apply_Arithmetic_Overflow_Check (N);
7189 -- Deal with VAX float case
7191 elsif Vax_Float (Typ) then
7192 Expand_Vax_Arith (N);
7195 end Expand_N_Op_Multiply;
7197 --------------------
7198 -- Expand_N_Op_Ne --
7199 --------------------
7201 procedure Expand_N_Op_Ne (N : Node_Id) is
7202 Typ : constant Entity_Id := Etype (Left_Opnd (N));
7205 -- Case of elementary type with standard operator
7207 if Is_Elementary_Type (Typ)
7208 and then Sloc (Entity (N)) = Standard_Location
7210 Binary_Op_Validity_Checks (N);
7212 -- Boolean types (requiring handling of non-standard case)
7214 if Is_Boolean_Type (Typ) then
7215 Adjust_Condition (Left_Opnd (N));
7216 Adjust_Condition (Right_Opnd (N));
7217 Set_Etype (N, Standard_Boolean);
7218 Adjust_Result_Type (N, Typ);
7221 Rewrite_Comparison (N);
7223 -- If we still have comparison for Vax_Float, process it
7225 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
7226 Expand_Vax_Comparison (N);
7230 -- For all cases other than elementary types, we rewrite node as the
7231 -- negation of an equality operation, and reanalyze. The equality to be
7232 -- used is defined in the same scope and has the same signature. This
7233 -- signature must be set explicitly since in an instance it may not have
7234 -- the same visibility as in the generic unit. This avoids duplicating
7235 -- or factoring the complex code for record/array equality tests etc.
7239 Loc : constant Source_Ptr := Sloc (N);
7241 Ne : constant Entity_Id := Entity (N);
7244 Binary_Op_Validity_Checks (N);
7250 Left_Opnd => Left_Opnd (N),
7251 Right_Opnd => Right_Opnd (N)));
7252 Set_Paren_Count (Right_Opnd (Neg), 1);
7254 if Scope (Ne) /= Standard_Standard then
7255 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
7258 -- For navigation purposes, we want to treat the inequality as an
7259 -- implicit reference to the corresponding equality. Preserve the
7260 -- Comes_From_ source flag to generate proper Xref entries.
7262 Preserve_Comes_From_Source (Neg, N);
7263 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
7265 Analyze_And_Resolve (N, Standard_Boolean);
7269 Optimize_Length_Comparison (N);
7272 ---------------------
7273 -- Expand_N_Op_Not --
7274 ---------------------
7276 -- If the argument is other than a Boolean array type, there is no special
7277 -- expansion required, except for VMS operations on signed integers.
7279 -- For the packed case, we call the special routine in Exp_Pakd, except
7280 -- that if the component size is greater than one, we use the standard
7281 -- routine generating a gruesome loop (it is so peculiar to have packed
7282 -- arrays with non-standard Boolean representations anyway, so it does not
7283 -- matter that we do not handle this case efficiently).
7285 -- For the unpacked case (and for the special packed case where we have non
7286 -- standard Booleans, as discussed above), we generate and insert into the
7287 -- tree the following function definition:
7289 -- function Nnnn (A : arr) is
7292 -- for J in a'range loop
7293 -- B (J) := not A (J);
7298 -- Here arr is the actual subtype of the parameter (and hence always
7299 -- constrained). Then we replace the not with a call to this function.
7301 procedure Expand_N_Op_Not (N : Node_Id) is
7302 Loc : constant Source_Ptr := Sloc (N);
7303 Typ : constant Entity_Id := Etype (N);
7312 Func_Name : Entity_Id;
7313 Loop_Statement : Node_Id;
7316 Unary_Op_Validity_Checks (N);
7318 -- For boolean operand, deal with non-standard booleans
7320 if Is_Boolean_Type (Typ) then
7321 Adjust_Condition (Right_Opnd (N));
7322 Set_Etype (N, Standard_Boolean);
7323 Adjust_Result_Type (N, Typ);
7327 -- For the VMS "not" on signed integer types, use conversion to and from
7328 -- a predefined modular type.
7330 if Is_VMS_Operator (Entity (N)) then
7336 -- If this is a derived type, retrieve original VMS type so that
7337 -- the proper sized type is used for intermediate values.
7339 if Is_Derived_Type (Typ) then
7340 Rtyp := First_Subtype (Etype (Typ));
7345 -- The proper unsigned type must have a size compatible with the
7346 -- operand, to prevent misalignment.
7348 if RM_Size (Rtyp) <= 8 then
7349 Utyp := RTE (RE_Unsigned_8);
7351 elsif RM_Size (Rtyp) <= 16 then
7352 Utyp := RTE (RE_Unsigned_16);
7354 elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
7355 Utyp := RTE (RE_Unsigned_32);
7358 Utyp := RTE (RE_Long_Long_Unsigned);
7362 Unchecked_Convert_To (Typ,
7364 Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
7365 Analyze_And_Resolve (N, Typ);
7370 -- Only array types need any other processing
7372 if not Is_Array_Type (Typ) then
7376 -- Case of array operand. If bit packed with a component size of 1,
7377 -- handle it in Exp_Pakd if the operand is known to be aligned.
7379 if Is_Bit_Packed_Array (Typ)
7380 and then Component_Size (Typ) = 1
7381 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
7383 Expand_Packed_Not (N);
7387 -- Case of array operand which is not bit-packed. If the context is
7388 -- a safe assignment, call in-place operation, If context is a larger
7389 -- boolean expression in the context of a safe assignment, expansion is
7390 -- done by enclosing operation.
7392 Opnd := Relocate_Node (Right_Opnd (N));
7393 Convert_To_Actual_Subtype (Opnd);
7394 Arr := Etype (Opnd);
7395 Ensure_Defined (Arr, N);
7396 Silly_Boolean_Array_Not_Test (N, Arr);
7398 if Nkind (Parent (N)) = N_Assignment_Statement then
7399 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
7400 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7403 -- Special case the negation of a binary operation
7405 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
7406 and then Safe_In_Place_Array_Op
7407 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
7409 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7413 elsif Nkind (Parent (N)) in N_Binary_Op
7414 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
7417 Op1 : constant Node_Id := Left_Opnd (Parent (N));
7418 Op2 : constant Node_Id := Right_Opnd (Parent (N));
7419 Lhs : constant Node_Id := Name (Parent (Parent (N)));
7422 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
7424 -- (not A) op (not B) can be reduced to a single call
7426 if N = Op1 and then Nkind (Op2) = N_Op_Not then
7429 elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
7432 -- A xor (not B) can also be special-cased
7434 elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
7441 A := Make_Defining_Identifier (Loc, Name_uA);
7442 B := Make_Defining_Identifier (Loc, Name_uB);
7443 J := Make_Defining_Identifier (Loc, Name_uJ);
7446 Make_Indexed_Component (Loc,
7447 Prefix => New_Reference_To (A, Loc),
7448 Expressions => New_List (New_Reference_To (J, Loc)));
7451 Make_Indexed_Component (Loc,
7452 Prefix => New_Reference_To (B, Loc),
7453 Expressions => New_List (New_Reference_To (J, Loc)));
7456 Make_Implicit_Loop_Statement (N,
7457 Identifier => Empty,
7460 Make_Iteration_Scheme (Loc,
7461 Loop_Parameter_Specification =>
7462 Make_Loop_Parameter_Specification (Loc,
7463 Defining_Identifier => J,
7464 Discrete_Subtype_Definition =>
7465 Make_Attribute_Reference (Loc,
7466 Prefix => Make_Identifier (Loc, Chars (A)),
7467 Attribute_Name => Name_Range))),
7469 Statements => New_List (
7470 Make_Assignment_Statement (Loc,
7472 Expression => Make_Op_Not (Loc, A_J))));
7474 Func_Name := Make_Temporary (Loc, 'N');
7475 Set_Is_Inlined (Func_Name);
7478 Make_Subprogram_Body (Loc,
7480 Make_Function_Specification (Loc,
7481 Defining_Unit_Name => Func_Name,
7482 Parameter_Specifications => New_List (
7483 Make_Parameter_Specification (Loc,
7484 Defining_Identifier => A,
7485 Parameter_Type => New_Reference_To (Typ, Loc))),
7486 Result_Definition => New_Reference_To (Typ, Loc)),
7488 Declarations => New_List (
7489 Make_Object_Declaration (Loc,
7490 Defining_Identifier => B,
7491 Object_Definition => New_Reference_To (Arr, Loc))),
7493 Handled_Statement_Sequence =>
7494 Make_Handled_Sequence_Of_Statements (Loc,
7495 Statements => New_List (
7497 Make_Simple_Return_Statement (Loc,
7498 Expression => Make_Identifier (Loc, Chars (B)))))));
7501 Make_Function_Call (Loc,
7502 Name => New_Reference_To (Func_Name, Loc),
7503 Parameter_Associations => New_List (Opnd)));
7505 Analyze_And_Resolve (N, Typ);
7506 end Expand_N_Op_Not;
7508 --------------------
7509 -- Expand_N_Op_Or --
7510 --------------------
7512 procedure Expand_N_Op_Or (N : Node_Id) is
7513 Typ : constant Entity_Id := Etype (N);
7516 Binary_Op_Validity_Checks (N);
7518 if Is_Array_Type (Etype (N)) then
7519 Expand_Boolean_Operator (N);
7521 elsif Is_Boolean_Type (Etype (N)) then
7522 Adjust_Condition (Left_Opnd (N));
7523 Adjust_Condition (Right_Opnd (N));
7524 Set_Etype (N, Standard_Boolean);
7525 Adjust_Result_Type (N, Typ);
7527 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7528 Expand_Intrinsic_Call (N, Entity (N));
7533 ----------------------
7534 -- Expand_N_Op_Plus --
7535 ----------------------
7537 procedure Expand_N_Op_Plus (N : Node_Id) is
7539 Unary_Op_Validity_Checks (N);
7540 end Expand_N_Op_Plus;
7542 ---------------------
7543 -- Expand_N_Op_Rem --
7544 ---------------------
7546 procedure Expand_N_Op_Rem (N : Node_Id) is
7547 Loc : constant Source_Ptr := Sloc (N);
7548 Typ : constant Entity_Id := Etype (N);
7550 Left : constant Node_Id := Left_Opnd (N);
7551 Right : constant Node_Id := Right_Opnd (N);
7559 -- Set if corresponding operand can be negative
7561 pragma Unreferenced (Hi);
7564 Binary_Op_Validity_Checks (N);
7566 if Is_Integer_Type (Etype (N)) then
7567 Apply_Divide_Check (N);
7570 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
7571 -- but it is useful with other back ends (e.g. AAMP), and is certainly
7574 if Is_Integer_Type (Etype (N))
7575 and then Compile_Time_Known_Value (Right)
7576 and then Expr_Value (Right) = Uint_1
7578 -- Call Remove_Side_Effects to ensure that any side effects in the
7579 -- ignored left operand (in particular function calls to user defined
7580 -- functions) are properly executed.
7582 Remove_Side_Effects (Left);
7584 Rewrite (N, Make_Integer_Literal (Loc, 0));
7585 Analyze_And_Resolve (N, Typ);
7589 -- Deal with annoying case of largest negative number remainder minus
7590 -- one. Gigi does not handle this case correctly, because it generates
7591 -- a divide instruction which may trap in this case.
7593 -- In fact the check is quite easy, if the right operand is -1, then
7594 -- the remainder is always 0, and we can just ignore the left operand
7595 -- completely in this case.
7597 Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
7598 Lneg := (not OK) or else Lo < 0;
7600 Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
7601 Rneg := (not OK) or else Lo < 0;
7603 -- We won't mess with trying to find out if the left operand can really
7604 -- be the largest negative number (that's a pain in the case of private
7605 -- types and this is really marginal). We will just assume that we need
7606 -- the test if the left operand can be negative at all.
7608 if Lneg and Rneg then
7610 Make_Conditional_Expression (Loc,
7611 Expressions => New_List (
7613 Left_Opnd => Duplicate_Subexpr (Right),
7615 Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
7617 Unchecked_Convert_To (Typ,
7618 Make_Integer_Literal (Loc, Uint_0)),
7620 Relocate_Node (N))));
7622 Set_Analyzed (Next (Next (First (Expressions (N)))));
7623 Analyze_And_Resolve (N, Typ);
7625 end Expand_N_Op_Rem;
7627 -----------------------------
7628 -- Expand_N_Op_Rotate_Left --
7629 -----------------------------
7631 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
7633 Binary_Op_Validity_Checks (N);
7634 end Expand_N_Op_Rotate_Left;
7636 ------------------------------
7637 -- Expand_N_Op_Rotate_Right --
7638 ------------------------------
7640 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
7642 Binary_Op_Validity_Checks (N);
7643 end Expand_N_Op_Rotate_Right;
7645 ----------------------------
7646 -- Expand_N_Op_Shift_Left --
7647 ----------------------------
7649 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
7651 Binary_Op_Validity_Checks (N);
7652 end Expand_N_Op_Shift_Left;
7654 -----------------------------
7655 -- Expand_N_Op_Shift_Right --
7656 -----------------------------
7658 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
7660 Binary_Op_Validity_Checks (N);
7661 end Expand_N_Op_Shift_Right;
7663 ----------------------------------------
7664 -- Expand_N_Op_Shift_Right_Arithmetic --
7665 ----------------------------------------
7667 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
7669 Binary_Op_Validity_Checks (N);
7670 end Expand_N_Op_Shift_Right_Arithmetic;
7672 --------------------------
7673 -- Expand_N_Op_Subtract --
7674 --------------------------
7676 procedure Expand_N_Op_Subtract (N : Node_Id) is
7677 Typ : constant Entity_Id := Etype (N);
7680 Binary_Op_Validity_Checks (N);
7682 -- N - 0 = N for integer types
7684 if Is_Integer_Type (Typ)
7685 and then Compile_Time_Known_Value (Right_Opnd (N))
7686 and then Expr_Value (Right_Opnd (N)) = 0
7688 Rewrite (N, Left_Opnd (N));
7692 -- Arithmetic overflow checks for signed integer/fixed point types
7694 if Is_Signed_Integer_Type (Typ)
7696 Is_Fixed_Point_Type (Typ)
7698 Apply_Arithmetic_Overflow_Check (N);
7700 -- VAX floating-point types case
7702 elsif Vax_Float (Typ) then
7703 Expand_Vax_Arith (N);
7705 end Expand_N_Op_Subtract;
7707 ---------------------
7708 -- Expand_N_Op_Xor --
7709 ---------------------
7711 procedure Expand_N_Op_Xor (N : Node_Id) is
7712 Typ : constant Entity_Id := Etype (N);
7715 Binary_Op_Validity_Checks (N);
7717 if Is_Array_Type (Etype (N)) then
7718 Expand_Boolean_Operator (N);
7720 elsif Is_Boolean_Type (Etype (N)) then
7721 Adjust_Condition (Left_Opnd (N));
7722 Adjust_Condition (Right_Opnd (N));
7723 Set_Etype (N, Standard_Boolean);
7724 Adjust_Result_Type (N, Typ);
7726 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7727 Expand_Intrinsic_Call (N, Entity (N));
7730 end Expand_N_Op_Xor;
7732 ----------------------
7733 -- Expand_N_Or_Else --
7734 ----------------------
7736 procedure Expand_N_Or_Else (N : Node_Id)
7737 renames Expand_Short_Circuit_Operator;
7739 -----------------------------------
7740 -- Expand_N_Qualified_Expression --
7741 -----------------------------------
7743 procedure Expand_N_Qualified_Expression (N : Node_Id) is
7744 Operand : constant Node_Id := Expression (N);
7745 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
7748 -- Do validity check if validity checking operands
7750 if Validity_Checks_On
7751 and then Validity_Check_Operands
7753 Ensure_Valid (Operand);
7756 -- Apply possible constraint check
7758 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
7760 if Do_Range_Check (Operand) then
7761 Set_Do_Range_Check (Operand, False);
7762 Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
7764 end Expand_N_Qualified_Expression;
7766 ------------------------------------
7767 -- Expand_N_Quantified_Expression --
7768 ------------------------------------
7772 -- for all X in range => Cond
7777 -- for X in range loop
7784 -- Conversely, an existentially quantified expression:
7786 -- for some X in range => Cond
7791 -- for X in range loop
7798 -- In both cases, the iteration may be over a container in which case it is
7799 -- given by an iterator specification, not a loop parameter specification.
7801 procedure Expand_N_Quantified_Expression (N : Node_Id) is
7802 Loc : constant Source_Ptr := Sloc (N);
7803 Is_Universal : constant Boolean := All_Present (N);
7804 Actions : constant List_Id := New_List;
7805 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
7813 Make_Object_Declaration (Loc,
7814 Defining_Identifier => Tnn,
7815 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
7817 New_Occurrence_Of (Boolean_Literals (Is_Universal), Loc));
7818 Append_To (Actions, Decl);
7820 Cond := Relocate_Node (Condition (N));
7822 -- Reset flag analyzed in the condition to force its analysis. Required
7823 -- since the previous analysis was done with expansion disabled (see
7824 -- Resolve_Quantified_Expression) and hence checks were not inserted
7825 -- and record comparisons have not been expanded.
7827 Reset_Analyzed_Flags (Cond);
7829 if Is_Universal then
7830 Cond := Make_Op_Not (Loc, Cond);
7834 Make_Implicit_If_Statement (N,
7836 Then_Statements => New_List (
7837 Make_Assignment_Statement (Loc,
7838 Name => New_Occurrence_Of (Tnn, Loc),
7840 New_Occurrence_Of (Boolean_Literals (not Is_Universal), Loc)),
7841 Make_Exit_Statement (Loc)));
7843 if Present (Loop_Parameter_Specification (N)) then
7845 Make_Iteration_Scheme (Loc,
7846 Loop_Parameter_Specification =>
7847 Loop_Parameter_Specification (N));
7850 Make_Iteration_Scheme (Loc,
7851 Iterator_Specification => Iterator_Specification (N));
7855 Make_Loop_Statement (Loc,
7856 Iteration_Scheme => I_Scheme,
7857 Statements => New_List (Test),
7858 End_Label => Empty));
7861 Make_Expression_With_Actions (Loc,
7862 Expression => New_Occurrence_Of (Tnn, Loc),
7863 Actions => Actions));
7865 Analyze_And_Resolve (N, Standard_Boolean);
7866 end Expand_N_Quantified_Expression;
7868 ---------------------------------
7869 -- Expand_N_Selected_Component --
7870 ---------------------------------
7872 -- If the selector is a discriminant of a concurrent object, rewrite the
7873 -- prefix to denote the corresponding record type.
7875 procedure Expand_N_Selected_Component (N : Node_Id) is
7876 Loc : constant Source_Ptr := Sloc (N);
7877 Par : constant Node_Id := Parent (N);
7878 P : constant Node_Id := Prefix (N);
7879 Ptyp : Entity_Id := Underlying_Type (Etype (P));
7885 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
7886 -- Gigi needs a temporary for prefixes that depend on a discriminant,
7887 -- unless the context of an assignment can provide size information.
7888 -- Don't we have a general routine that does this???
7890 function Is_Subtype_Declaration return Boolean;
7891 -- The replacement of a discriminant reference by its value is required
7892 -- if this is part of the initialization of an temporary generated by a
7893 -- change of representation. This shows up as the construction of a
7894 -- discriminant constraint for a subtype declared at the same point as
7895 -- the entity in the prefix of the selected component. We recognize this
7896 -- case when the context of the reference is:
7897 -- subtype ST is T(Obj.D);
7898 -- where the entity for Obj comes from source, and ST has the same sloc.
7900 -----------------------
7901 -- In_Left_Hand_Side --
7902 -----------------------
7904 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
7906 return (Nkind (Parent (Comp)) = N_Assignment_Statement
7907 and then Comp = Name (Parent (Comp)))
7908 or else (Present (Parent (Comp))
7909 and then Nkind (Parent (Comp)) in N_Subexpr
7910 and then In_Left_Hand_Side (Parent (Comp)));
7911 end In_Left_Hand_Side;
7913 -----------------------------
7914 -- Is_Subtype_Declaration --
7915 -----------------------------
7917 function Is_Subtype_Declaration return Boolean is
7918 Par : constant Node_Id := Parent (N);
7921 Nkind (Par) = N_Index_Or_Discriminant_Constraint
7922 and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration
7923 and then Comes_From_Source (Entity (Prefix (N)))
7924 and then Sloc (Par) = Sloc (Entity (Prefix (N)));
7925 end Is_Subtype_Declaration;
7927 -- Start of processing for Expand_N_Selected_Component
7930 -- Insert explicit dereference if required
7932 if Is_Access_Type (Ptyp) then
7934 -- First set prefix type to proper access type, in case it currently
7935 -- has a private (non-access) view of this type.
7937 Set_Etype (P, Ptyp);
7939 Insert_Explicit_Dereference (P);
7940 Analyze_And_Resolve (P, Designated_Type (Ptyp));
7942 if Ekind (Etype (P)) = E_Private_Subtype
7943 and then Is_For_Access_Subtype (Etype (P))
7945 Set_Etype (P, Base_Type (Etype (P)));
7951 -- Deal with discriminant check required
7953 if Do_Discriminant_Check (N) then
7955 -- Present the discriminant checking function to the backend, so that
7956 -- it can inline the call to the function.
7959 (Discriminant_Checking_Func
7960 (Original_Record_Component (Entity (Selector_Name (N)))));
7962 -- Now reset the flag and generate the call
7964 Set_Do_Discriminant_Check (N, False);
7965 Generate_Discriminant_Check (N);
7968 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7969 -- function, then additional actuals must be passed.
7971 if Ada_Version >= Ada_2005
7972 and then Is_Build_In_Place_Function_Call (P)
7974 Make_Build_In_Place_Call_In_Anonymous_Context (P);
7977 -- Gigi cannot handle unchecked conversions that are the prefix of a
7978 -- selected component with discriminants. This must be checked during
7979 -- expansion, because during analysis the type of the selector is not
7980 -- known at the point the prefix is analyzed. If the conversion is the
7981 -- target of an assignment, then we cannot force the evaluation.
7983 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
7984 and then Has_Discriminants (Etype (N))
7985 and then not In_Left_Hand_Side (N)
7987 Force_Evaluation (Prefix (N));
7990 -- Remaining processing applies only if selector is a discriminant
7992 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
7994 -- If the selector is a discriminant of a constrained record type,
7995 -- we may be able to rewrite the expression with the actual value
7996 -- of the discriminant, a useful optimization in some cases.
7998 if Is_Record_Type (Ptyp)
7999 and then Has_Discriminants (Ptyp)
8000 and then Is_Constrained (Ptyp)
8002 -- Do this optimization for discrete types only, and not for
8003 -- access types (access discriminants get us into trouble!)
8005 if not Is_Discrete_Type (Etype (N)) then
8008 -- Don't do this on the left hand of an assignment statement.
8009 -- Normally one would think that references like this would not
8010 -- occur, but they do in generated code, and mean that we really
8011 -- do want to assign the discriminant!
8013 elsif Nkind (Par) = N_Assignment_Statement
8014 and then Name (Par) = N
8018 -- Don't do this optimization for the prefix of an attribute or
8019 -- the name of an object renaming declaration since these are
8020 -- contexts where we do not want the value anyway.
8022 elsif (Nkind (Par) = N_Attribute_Reference
8023 and then Prefix (Par) = N)
8024 or else Is_Renamed_Object (N)
8028 -- Don't do this optimization if we are within the code for a
8029 -- discriminant check, since the whole point of such a check may
8030 -- be to verify the condition on which the code below depends!
8032 elsif Is_In_Discriminant_Check (N) then
8035 -- Green light to see if we can do the optimization. There is
8036 -- still one condition that inhibits the optimization below but
8037 -- now is the time to check the particular discriminant.
8040 -- Loop through discriminants to find the matching discriminant
8041 -- constraint to see if we can copy it.
8043 Disc := First_Discriminant (Ptyp);
8044 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
8045 Discr_Loop : while Present (Dcon) loop
8046 Dval := Node (Dcon);
8048 -- Check if this is the matching discriminant and if the
8049 -- discriminant value is simple enough to make sense to
8050 -- copy. We don't want to copy complex expressions, and
8051 -- indeed to do so can cause trouble (before we put in
8052 -- this guard, a discriminant expression containing an
8053 -- AND THEN was copied, causing problems for coverage
8056 -- However, if the reference is part of the initialization
8057 -- code generated for an object declaration, we must use
8058 -- the discriminant value from the subtype constraint,
8059 -- because the selected component may be a reference to the
8060 -- object being initialized, whose discriminant is not yet
8061 -- set. This only happens in complex cases involving changes
8062 -- or representation.
8064 if Disc = Entity (Selector_Name (N))
8065 and then (Is_Entity_Name (Dval)
8066 or else Compile_Time_Known_Value (Dval)
8067 or else Is_Subtype_Declaration)
8069 -- Here we have the matching discriminant. Check for
8070 -- the case of a discriminant of a component that is
8071 -- constrained by an outer discriminant, which cannot
8072 -- be optimized away.
8074 if Denotes_Discriminant
8075 (Dval, Check_Concurrent => True)
8079 elsif Nkind (Original_Node (Dval)) = N_Selected_Component
8081 Denotes_Discriminant
8082 (Selector_Name (Original_Node (Dval)), True)
8086 -- Do not retrieve value if constraint is not static. It
8087 -- is generally not useful, and the constraint may be a
8088 -- rewritten outer discriminant in which case it is in
8091 elsif Is_Entity_Name (Dval)
8092 and then Nkind (Parent (Entity (Dval))) =
8093 N_Object_Declaration
8094 and then Present (Expression (Parent (Entity (Dval))))
8096 not Is_Static_Expression
8097 (Expression (Parent (Entity (Dval))))
8101 -- In the context of a case statement, the expression may
8102 -- have the base type of the discriminant, and we need to
8103 -- preserve the constraint to avoid spurious errors on
8106 elsif Nkind (Parent (N)) = N_Case_Statement
8107 and then Etype (Dval) /= Etype (Disc)
8110 Make_Qualified_Expression (Loc,
8112 New_Occurrence_Of (Etype (Disc), Loc),
8114 New_Copy_Tree (Dval)));
8115 Analyze_And_Resolve (N, Etype (Disc));
8117 -- In case that comes out as a static expression,
8118 -- reset it (a selected component is never static).
8120 Set_Is_Static_Expression (N, False);
8123 -- Otherwise we can just copy the constraint, but the
8124 -- result is certainly not static! In some cases the
8125 -- discriminant constraint has been analyzed in the
8126 -- context of the original subtype indication, but for
8127 -- itypes the constraint might not have been analyzed
8128 -- yet, and this must be done now.
8131 Rewrite (N, New_Copy_Tree (Dval));
8132 Analyze_And_Resolve (N);
8133 Set_Is_Static_Expression (N, False);
8139 Next_Discriminant (Disc);
8140 end loop Discr_Loop;
8142 -- Note: the above loop should always find a matching
8143 -- discriminant, but if it does not, we just missed an
8144 -- optimization due to some glitch (perhaps a previous
8145 -- error), so ignore.
8150 -- The only remaining processing is in the case of a discriminant of
8151 -- a concurrent object, where we rewrite the prefix to denote the
8152 -- corresponding record type. If the type is derived and has renamed
8153 -- discriminants, use corresponding discriminant, which is the one
8154 -- that appears in the corresponding record.
8156 if not Is_Concurrent_Type (Ptyp) then
8160 Disc := Entity (Selector_Name (N));
8162 if Is_Derived_Type (Ptyp)
8163 and then Present (Corresponding_Discriminant (Disc))
8165 Disc := Corresponding_Discriminant (Disc);
8169 Make_Selected_Component (Loc,
8171 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
8173 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
8178 end Expand_N_Selected_Component;
8180 --------------------
8181 -- Expand_N_Slice --
8182 --------------------
8184 procedure Expand_N_Slice (N : Node_Id) is
8185 Loc : constant Source_Ptr := Sloc (N);
8186 Typ : constant Entity_Id := Etype (N);
8187 Pfx : constant Node_Id := Prefix (N);
8188 Ptp : Entity_Id := Etype (Pfx);
8190 function Is_Procedure_Actual (N : Node_Id) return Boolean;
8191 -- Check whether the argument is an actual for a procedure call, in
8192 -- which case the expansion of a bit-packed slice is deferred until the
8193 -- call itself is expanded. The reason this is required is that we might
8194 -- have an IN OUT or OUT parameter, and the copy out is essential, and
8195 -- that copy out would be missed if we created a temporary here in
8196 -- Expand_N_Slice. Note that we don't bother to test specifically for an
8197 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
8198 -- is harmless to defer expansion in the IN case, since the call
8199 -- processing will still generate the appropriate copy in operation,
8200 -- which will take care of the slice.
8202 procedure Make_Temporary_For_Slice;
8203 -- Create a named variable for the value of the slice, in cases where
8204 -- the back-end cannot handle it properly, e.g. when packed types or
8205 -- unaligned slices are involved.
8207 -------------------------
8208 -- Is_Procedure_Actual --
8209 -------------------------
8211 function Is_Procedure_Actual (N : Node_Id) return Boolean is
8212 Par : Node_Id := Parent (N);
8216 -- If our parent is a procedure call we can return
8218 if Nkind (Par) = N_Procedure_Call_Statement then
8221 -- If our parent is a type conversion, keep climbing the tree,
8222 -- since a type conversion can be a procedure actual. Also keep
8223 -- climbing if parameter association or a qualified expression,
8224 -- since these are additional cases that do can appear on
8225 -- procedure actuals.
8227 elsif Nkind_In (Par, N_Type_Conversion,
8228 N_Parameter_Association,
8229 N_Qualified_Expression)
8231 Par := Parent (Par);
8233 -- Any other case is not what we are looking for
8239 end Is_Procedure_Actual;
8241 ------------------------------
8242 -- Make_Temporary_For_Slice --
8243 ------------------------------
8245 procedure Make_Temporary_For_Slice is
8247 Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
8251 Make_Object_Declaration (Loc,
8252 Defining_Identifier => Ent,
8253 Object_Definition => New_Occurrence_Of (Typ, Loc));
8255 Set_No_Initialization (Decl);
8257 Insert_Actions (N, New_List (
8259 Make_Assignment_Statement (Loc,
8260 Name => New_Occurrence_Of (Ent, Loc),
8261 Expression => Relocate_Node (N))));
8263 Rewrite (N, New_Occurrence_Of (Ent, Loc));
8264 Analyze_And_Resolve (N, Typ);
8265 end Make_Temporary_For_Slice;
8267 -- Start of processing for Expand_N_Slice
8270 -- Special handling for access types
8272 if Is_Access_Type (Ptp) then
8274 Ptp := Designated_Type (Ptp);
8277 Make_Explicit_Dereference (Sloc (N),
8278 Prefix => Relocate_Node (Pfx)));
8280 Analyze_And_Resolve (Pfx, Ptp);
8283 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
8284 -- function, then additional actuals must be passed.
8286 if Ada_Version >= Ada_2005
8287 and then Is_Build_In_Place_Function_Call (Pfx)
8289 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
8292 -- The remaining case to be handled is packed slices. We can leave
8293 -- packed slices as they are in the following situations:
8295 -- 1. Right or left side of an assignment (we can handle this
8296 -- situation correctly in the assignment statement expansion).
8298 -- 2. Prefix of indexed component (the slide is optimized away in this
8299 -- case, see the start of Expand_N_Slice.)
8301 -- 3. Object renaming declaration, since we want the name of the
8302 -- slice, not the value.
8304 -- 4. Argument to procedure call, since copy-in/copy-out handling may
8305 -- be required, and this is handled in the expansion of call
8308 -- 5. Prefix of an address attribute (this is an error which is caught
8309 -- elsewhere, and the expansion would interfere with generating the
8312 if not Is_Packed (Typ) then
8314 -- Apply transformation for actuals of a function call, where
8315 -- Expand_Actuals is not used.
8317 if Nkind (Parent (N)) = N_Function_Call
8318 and then Is_Possibly_Unaligned_Slice (N)
8320 Make_Temporary_For_Slice;
8323 elsif Nkind (Parent (N)) = N_Assignment_Statement
8324 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
8325 and then Parent (N) = Name (Parent (Parent (N))))
8329 elsif Nkind (Parent (N)) = N_Indexed_Component
8330 or else Is_Renamed_Object (N)
8331 or else Is_Procedure_Actual (N)
8335 elsif Nkind (Parent (N)) = N_Attribute_Reference
8336 and then Attribute_Name (Parent (N)) = Name_Address
8341 Make_Temporary_For_Slice;
8345 ------------------------------
8346 -- Expand_N_Type_Conversion --
8347 ------------------------------
8349 procedure Expand_N_Type_Conversion (N : Node_Id) is
8350 Loc : constant Source_Ptr := Sloc (N);
8351 Operand : constant Node_Id := Expression (N);
8352 Target_Type : constant Entity_Id := Etype (N);
8353 Operand_Type : Entity_Id := Etype (Operand);
8355 procedure Handle_Changed_Representation;
8356 -- This is called in the case of record and array type conversions to
8357 -- see if there is a change of representation to be handled. Change of
8358 -- representation is actually handled at the assignment statement level,
8359 -- and what this procedure does is rewrite node N conversion as an
8360 -- assignment to temporary. If there is no change of representation,
8361 -- then the conversion node is unchanged.
8363 procedure Raise_Accessibility_Error;
8364 -- Called when we know that an accessibility check will fail. Rewrites
8365 -- node N to an appropriate raise statement and outputs warning msgs.
8366 -- The Etype of the raise node is set to Target_Type.
8368 procedure Real_Range_Check;
8369 -- Handles generation of range check for real target value
8371 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean;
8372 -- True iff Present (Effective_Extra_Accessibility (Id)) successfully
8373 -- evaluates to True.
8375 -----------------------------------
8376 -- Handle_Changed_Representation --
8377 -----------------------------------
8379 procedure Handle_Changed_Representation is
8388 -- Nothing else to do if no change of representation
8390 if Same_Representation (Operand_Type, Target_Type) then
8393 -- The real change of representation work is done by the assignment
8394 -- statement processing. So if this type conversion is appearing as
8395 -- the expression of an assignment statement, nothing needs to be
8396 -- done to the conversion.
8398 elsif Nkind (Parent (N)) = N_Assignment_Statement then
8401 -- Otherwise we need to generate a temporary variable, and do the
8402 -- change of representation assignment into that temporary variable.
8403 -- The conversion is then replaced by a reference to this variable.
8408 -- If type is unconstrained we have to add a constraint, copied
8409 -- from the actual value of the left hand side.
8411 if not Is_Constrained (Target_Type) then
8412 if Has_Discriminants (Operand_Type) then
8413 Disc := First_Discriminant (Operand_Type);
8415 if Disc /= First_Stored_Discriminant (Operand_Type) then
8416 Disc := First_Stored_Discriminant (Operand_Type);
8420 while Present (Disc) loop
8422 Make_Selected_Component (Loc,
8424 Duplicate_Subexpr_Move_Checks (Operand),
8426 Make_Identifier (Loc, Chars (Disc))));
8427 Next_Discriminant (Disc);
8430 elsif Is_Array_Type (Operand_Type) then
8431 N_Ix := First_Index (Target_Type);
8434 for J in 1 .. Number_Dimensions (Operand_Type) loop
8436 -- We convert the bounds explicitly. We use an unchecked
8437 -- conversion because bounds checks are done elsewhere.
8442 Unchecked_Convert_To (Etype (N_Ix),
8443 Make_Attribute_Reference (Loc,
8445 Duplicate_Subexpr_No_Checks
8446 (Operand, Name_Req => True),
8447 Attribute_Name => Name_First,
8448 Expressions => New_List (
8449 Make_Integer_Literal (Loc, J)))),
8452 Unchecked_Convert_To (Etype (N_Ix),
8453 Make_Attribute_Reference (Loc,
8455 Duplicate_Subexpr_No_Checks
8456 (Operand, Name_Req => True),
8457 Attribute_Name => Name_Last,
8458 Expressions => New_List (
8459 Make_Integer_Literal (Loc, J))))));
8466 Odef := New_Occurrence_Of (Target_Type, Loc);
8468 if Present (Cons) then
8470 Make_Subtype_Indication (Loc,
8471 Subtype_Mark => Odef,
8473 Make_Index_Or_Discriminant_Constraint (Loc,
8474 Constraints => Cons));
8477 Temp := Make_Temporary (Loc, 'C');
8479 Make_Object_Declaration (Loc,
8480 Defining_Identifier => Temp,
8481 Object_Definition => Odef);
8483 Set_No_Initialization (Decl, True);
8485 -- Insert required actions. It is essential to suppress checks
8486 -- since we have suppressed default initialization, which means
8487 -- that the variable we create may have no discriminants.
8492 Make_Assignment_Statement (Loc,
8493 Name => New_Occurrence_Of (Temp, Loc),
8494 Expression => Relocate_Node (N))),
8495 Suppress => All_Checks);
8497 Rewrite (N, New_Occurrence_Of (Temp, Loc));
8500 end Handle_Changed_Representation;
8502 -------------------------------
8503 -- Raise_Accessibility_Error --
8504 -------------------------------
8506 procedure Raise_Accessibility_Error is
8509 Make_Raise_Program_Error (Sloc (N),
8510 Reason => PE_Accessibility_Check_Failed));
8511 Set_Etype (N, Target_Type);
8513 Error_Msg_N ("?accessibility check failure", N);
8515 ("\?& will be raised at run time", N, Standard_Program_Error);
8516 end Raise_Accessibility_Error;
8518 ----------------------
8519 -- Real_Range_Check --
8520 ----------------------
8522 -- Case of conversions to floating-point or fixed-point. If range checks
8523 -- are enabled and the target type has a range constraint, we convert:
8529 -- Tnn : typ'Base := typ'Base (x);
8530 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
8533 -- This is necessary when there is a conversion of integer to float or
8534 -- to fixed-point to ensure that the correct checks are made. It is not
8535 -- necessary for float to float where it is enough to simply set the
8536 -- Do_Range_Check flag.
8538 procedure Real_Range_Check is
8539 Btyp : constant Entity_Id := Base_Type (Target_Type);
8540 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
8541 Hi : constant Node_Id := Type_High_Bound (Target_Type);
8542 Xtyp : constant Entity_Id := Etype (Operand);
8547 -- Nothing to do if conversion was rewritten
8549 if Nkind (N) /= N_Type_Conversion then
8553 -- Nothing to do if range checks suppressed, or target has the same
8554 -- range as the base type (or is the base type).
8556 if Range_Checks_Suppressed (Target_Type)
8557 or else (Lo = Type_Low_Bound (Btyp)
8559 Hi = Type_High_Bound (Btyp))
8564 -- Nothing to do if expression is an entity on which checks have been
8567 if Is_Entity_Name (Operand)
8568 and then Range_Checks_Suppressed (Entity (Operand))
8573 -- Nothing to do if bounds are all static and we can tell that the
8574 -- expression is within the bounds of the target. Note that if the
8575 -- operand is of an unconstrained floating-point type, then we do
8576 -- not trust it to be in range (might be infinite)
8579 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
8580 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
8583 if (not Is_Floating_Point_Type (Xtyp)
8584 or else Is_Constrained (Xtyp))
8585 and then Compile_Time_Known_Value (S_Lo)
8586 and then Compile_Time_Known_Value (S_Hi)
8587 and then Compile_Time_Known_Value (Hi)
8588 and then Compile_Time_Known_Value (Lo)
8591 D_Lov : constant Ureal := Expr_Value_R (Lo);
8592 D_Hiv : constant Ureal := Expr_Value_R (Hi);
8597 if Is_Real_Type (Xtyp) then
8598 S_Lov := Expr_Value_R (S_Lo);
8599 S_Hiv := Expr_Value_R (S_Hi);
8601 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
8602 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
8606 and then S_Lov >= D_Lov
8607 and then S_Hiv <= D_Hiv
8609 Set_Do_Range_Check (Operand, False);
8616 -- For float to float conversions, we are done
8618 if Is_Floating_Point_Type (Xtyp)
8620 Is_Floating_Point_Type (Btyp)
8625 -- Otherwise rewrite the conversion as described above
8627 Conv := Relocate_Node (N);
8628 Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
8629 Set_Etype (Conv, Btyp);
8631 -- Enable overflow except for case of integer to float conversions,
8632 -- where it is never required, since we can never have overflow in
8635 if not Is_Integer_Type (Etype (Operand)) then
8636 Enable_Overflow_Check (Conv);
8639 Tnn := Make_Temporary (Loc, 'T', Conv);
8641 Insert_Actions (N, New_List (
8642 Make_Object_Declaration (Loc,
8643 Defining_Identifier => Tnn,
8644 Object_Definition => New_Occurrence_Of (Btyp, Loc),
8645 Constant_Present => True,
8646 Expression => Conv),
8648 Make_Raise_Constraint_Error (Loc,
8653 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8655 Make_Attribute_Reference (Loc,
8656 Attribute_Name => Name_First,
8658 New_Occurrence_Of (Target_Type, Loc))),
8662 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8664 Make_Attribute_Reference (Loc,
8665 Attribute_Name => Name_Last,
8667 New_Occurrence_Of (Target_Type, Loc)))),
8668 Reason => CE_Range_Check_Failed)));
8670 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
8671 Analyze_And_Resolve (N, Btyp);
8672 end Real_Range_Check;
8674 -----------------------------
8675 -- Has_Extra_Accessibility --
8676 -----------------------------
8678 -- Returns true for a formal of an anonymous access type or for
8679 -- an Ada 2012-style stand-alone object of an anonymous access type.
8681 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean is
8683 if Is_Formal (Id) or else Ekind_In (Id, E_Constant, E_Variable) then
8684 return Present (Effective_Extra_Accessibility (Id));
8688 end Has_Extra_Accessibility;
8690 -- Start of processing for Expand_N_Type_Conversion
8693 -- Nothing at all to do if conversion is to the identical type so remove
8694 -- the conversion completely, it is useless, except that it may carry
8695 -- an Assignment_OK attribute, which must be propagated to the operand.
8697 if Operand_Type = Target_Type then
8698 if Assignment_OK (N) then
8699 Set_Assignment_OK (Operand);
8702 Rewrite (N, Relocate_Node (Operand));
8706 -- Nothing to do if this is the second argument of read. This is a
8707 -- "backwards" conversion that will be handled by the specialized code
8708 -- in attribute processing.
8710 if Nkind (Parent (N)) = N_Attribute_Reference
8711 and then Attribute_Name (Parent (N)) = Name_Read
8712 and then Next (First (Expressions (Parent (N)))) = N
8717 -- Check for case of converting to a type that has an invariant
8718 -- associated with it. This required an invariant check. We convert
8724 -- do invariant_check (typ (expr)) in typ (expr);
8726 -- using Duplicate_Subexpr to avoid multiple side effects
8728 -- Note: the Comes_From_Source check, and then the resetting of this
8729 -- flag prevents what would otherwise be an infinite recursion.
8731 if Has_Invariants (Target_Type)
8732 and then Present (Invariant_Procedure (Target_Type))
8733 and then Comes_From_Source (N)
8735 Set_Comes_From_Source (N, False);
8737 Make_Expression_With_Actions (Loc,
8738 Actions => New_List (
8739 Make_Invariant_Call (Duplicate_Subexpr (N))),
8740 Expression => Duplicate_Subexpr_No_Checks (N)));
8741 Analyze_And_Resolve (N, Target_Type);
8745 -- Here if we may need to expand conversion
8747 -- If the operand of the type conversion is an arithmetic operation on
8748 -- signed integers, and the based type of the signed integer type in
8749 -- question is smaller than Standard.Integer, we promote both of the
8750 -- operands to type Integer.
8752 -- For example, if we have
8754 -- target-type (opnd1 + opnd2)
8756 -- and opnd1 and opnd2 are of type short integer, then we rewrite
8759 -- target-type (integer(opnd1) + integer(opnd2))
8761 -- We do this because we are always allowed to compute in a larger type
8762 -- if we do the right thing with the result, and in this case we are
8763 -- going to do a conversion which will do an appropriate check to make
8764 -- sure that things are in range of the target type in any case. This
8765 -- avoids some unnecessary intermediate overflows.
8767 -- We might consider a similar transformation in the case where the
8768 -- target is a real type or a 64-bit integer type, and the operand
8769 -- is an arithmetic operation using a 32-bit integer type. However,
8770 -- we do not bother with this case, because it could cause significant
8771 -- inefficiencies on 32-bit machines. On a 64-bit machine it would be
8772 -- much cheaper, but we don't want different behavior on 32-bit and
8773 -- 64-bit machines. Note that the exclusion of the 64-bit case also
8774 -- handles the configurable run-time cases where 64-bit arithmetic
8775 -- may simply be unavailable.
8777 -- Note: this circuit is partially redundant with respect to the circuit
8778 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
8779 -- the processing here. Also we still need the Checks circuit, since we
8780 -- have to be sure not to generate junk overflow checks in the first
8781 -- place, since it would be trick to remove them here!
8783 if Integer_Promotion_Possible (N) then
8785 -- All conditions met, go ahead with transformation
8793 Make_Type_Conversion (Loc,
8794 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8795 Expression => Relocate_Node (Right_Opnd (Operand)));
8797 Opnd := New_Op_Node (Nkind (Operand), Loc);
8798 Set_Right_Opnd (Opnd, R);
8800 if Nkind (Operand) in N_Binary_Op then
8802 Make_Type_Conversion (Loc,
8803 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8804 Expression => Relocate_Node (Left_Opnd (Operand)));
8806 Set_Left_Opnd (Opnd, L);
8810 Make_Type_Conversion (Loc,
8811 Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
8812 Expression => Opnd));
8814 Analyze_And_Resolve (N, Target_Type);
8819 -- Do validity check if validity checking operands
8821 if Validity_Checks_On
8822 and then Validity_Check_Operands
8824 Ensure_Valid (Operand);
8827 -- Special case of converting from non-standard boolean type
8829 if Is_Boolean_Type (Operand_Type)
8830 and then (Nonzero_Is_True (Operand_Type))
8832 Adjust_Condition (Operand);
8833 Set_Etype (Operand, Standard_Boolean);
8834 Operand_Type := Standard_Boolean;
8837 -- Case of converting to an access type
8839 if Is_Access_Type (Target_Type) then
8841 -- Apply an accessibility check when the conversion operand is an
8842 -- access parameter (or a renaming thereof), unless conversion was
8843 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
8844 -- Note that other checks may still need to be applied below (such
8845 -- as tagged type checks).
8847 if Is_Entity_Name (Operand)
8848 and then Has_Extra_Accessibility (Entity (Operand))
8849 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
8850 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
8851 or else Attribute_Name (Original_Node (N)) = Name_Access)
8853 Apply_Accessibility_Check
8854 (Operand, Target_Type, Insert_Node => Operand);
8856 -- If the level of the operand type is statically deeper than the
8857 -- level of the target type, then force Program_Error. Note that this
8858 -- can only occur for cases where the attribute is within the body of
8859 -- an instantiation (otherwise the conversion will already have been
8860 -- rejected as illegal). Note: warnings are issued by the analyzer
8861 -- for the instance cases.
8863 elsif In_Instance_Body
8864 and then Type_Access_Level (Operand_Type) >
8865 Type_Access_Level (Target_Type)
8867 Raise_Accessibility_Error;
8869 -- When the operand is a selected access discriminant the check needs
8870 -- to be made against the level of the object denoted by the prefix
8871 -- of the selected name. Force Program_Error for this case as well
8872 -- (this accessibility violation can only happen if within the body
8873 -- of an instantiation).
8875 elsif In_Instance_Body
8876 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
8877 and then Nkind (Operand) = N_Selected_Component
8878 and then Object_Access_Level (Operand) >
8879 Type_Access_Level (Target_Type)
8881 Raise_Accessibility_Error;
8886 -- Case of conversions of tagged types and access to tagged types
8888 -- When needed, that is to say when the expression is class-wide, Add
8889 -- runtime a tag check for (strict) downward conversion by using the
8890 -- membership test, generating:
8892 -- [constraint_error when Operand not in Target_Type'Class]
8894 -- or in the access type case
8896 -- [constraint_error
8897 -- when Operand /= null
8898 -- and then Operand.all not in
8899 -- Designated_Type (Target_Type)'Class]
8901 if (Is_Access_Type (Target_Type)
8902 and then Is_Tagged_Type (Designated_Type (Target_Type)))
8903 or else Is_Tagged_Type (Target_Type)
8905 -- Do not do any expansion in the access type case if the parent is a
8906 -- renaming, since this is an error situation which will be caught by
8907 -- Sem_Ch8, and the expansion can interfere with this error check.
8909 if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
8913 -- Otherwise, proceed with processing tagged conversion
8915 Tagged_Conversion : declare
8916 Actual_Op_Typ : Entity_Id;
8917 Actual_Targ_Typ : Entity_Id;
8918 Make_Conversion : Boolean := False;
8919 Root_Op_Typ : Entity_Id;
8921 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
8922 -- Create a membership check to test whether Operand is a member
8923 -- of Targ_Typ. If the original Target_Type is an access, include
8924 -- a test for null value. The check is inserted at N.
8926 --------------------
8927 -- Make_Tag_Check --
8928 --------------------
8930 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
8935 -- [Constraint_Error
8936 -- when Operand /= null
8937 -- and then Operand.all not in Targ_Typ]
8939 if Is_Access_Type (Target_Type) then
8944 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8945 Right_Opnd => Make_Null (Loc)),
8950 Make_Explicit_Dereference (Loc,
8951 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
8952 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
8955 -- [Constraint_Error when Operand not in Targ_Typ]
8960 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
8961 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
8965 Make_Raise_Constraint_Error (Loc,
8967 Reason => CE_Tag_Check_Failed));
8970 -- Start of processing for Tagged_Conversion
8973 -- Handle entities from the limited view
8975 if Is_Access_Type (Operand_Type) then
8977 Available_View (Designated_Type (Operand_Type));
8979 Actual_Op_Typ := Operand_Type;
8982 if Is_Access_Type (Target_Type) then
8984 Available_View (Designated_Type (Target_Type));
8986 Actual_Targ_Typ := Target_Type;
8989 Root_Op_Typ := Root_Type (Actual_Op_Typ);
8991 -- Ada 2005 (AI-251): Handle interface type conversion
8993 if Is_Interface (Actual_Op_Typ) then
8994 Expand_Interface_Conversion (N, Is_Static => False);
8998 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
9000 -- Create a runtime tag check for a downward class-wide type
9003 if Is_Class_Wide_Type (Actual_Op_Typ)
9004 and then Actual_Op_Typ /= Actual_Targ_Typ
9005 and then Root_Op_Typ /= Actual_Targ_Typ
9006 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ,
9007 Use_Full_View => True)
9009 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
9010 Make_Conversion := True;
9013 -- AI05-0073: If the result subtype of the function is defined
9014 -- by an access_definition designating a specific tagged type
9015 -- T, a check is made that the result value is null or the tag
9016 -- of the object designated by the result value identifies T.
9017 -- Constraint_Error is raised if this check fails.
9019 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
9022 Func_Typ : Entity_Id;
9025 -- Climb scope stack looking for the enclosing function
9027 Func := Current_Scope;
9028 while Present (Func)
9029 and then Ekind (Func) /= E_Function
9031 Func := Scope (Func);
9034 -- The function's return subtype must be defined using
9035 -- an access definition.
9037 if Nkind (Result_Definition (Parent (Func))) =
9040 Func_Typ := Directly_Designated_Type (Etype (Func));
9042 -- The return subtype denotes a specific tagged type,
9043 -- in other words, a non class-wide type.
9045 if Is_Tagged_Type (Func_Typ)
9046 and then not Is_Class_Wide_Type (Func_Typ)
9048 Make_Tag_Check (Actual_Targ_Typ);
9049 Make_Conversion := True;
9055 -- We have generated a tag check for either a class-wide type
9056 -- conversion or for AI05-0073.
9058 if Make_Conversion then
9063 Make_Unchecked_Type_Conversion (Loc,
9064 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
9065 Expression => Relocate_Node (Expression (N)));
9067 Analyze_And_Resolve (N, Target_Type);
9071 end Tagged_Conversion;
9073 -- Case of other access type conversions
9075 elsif Is_Access_Type (Target_Type) then
9076 Apply_Constraint_Check (Operand, Target_Type);
9078 -- Case of conversions from a fixed-point type
9080 -- These conversions require special expansion and processing, found in
9081 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
9082 -- since from a semantic point of view, these are simple integer
9083 -- conversions, which do not need further processing.
9085 elsif Is_Fixed_Point_Type (Operand_Type)
9086 and then not Conversion_OK (N)
9088 -- We should never see universal fixed at this case, since the
9089 -- expansion of the constituent divide or multiply should have
9090 -- eliminated the explicit mention of universal fixed.
9092 pragma Assert (Operand_Type /= Universal_Fixed);
9094 -- Check for special case of the conversion to universal real that
9095 -- occurs as a result of the use of a round attribute. In this case,
9096 -- the real type for the conversion is taken from the target type of
9097 -- the Round attribute and the result must be marked as rounded.
9099 if Target_Type = Universal_Real
9100 and then Nkind (Parent (N)) = N_Attribute_Reference
9101 and then Attribute_Name (Parent (N)) = Name_Round
9103 Set_Rounded_Result (N);
9104 Set_Etype (N, Etype (Parent (N)));
9107 -- Otherwise do correct fixed-conversion, but skip these if the
9108 -- Conversion_OK flag is set, because from a semantic point of view
9109 -- these are simple integer conversions needing no further processing
9110 -- (the backend will simply treat them as integers).
9112 if not Conversion_OK (N) then
9113 if Is_Fixed_Point_Type (Etype (N)) then
9114 Expand_Convert_Fixed_To_Fixed (N);
9117 elsif Is_Integer_Type (Etype (N)) then
9118 Expand_Convert_Fixed_To_Integer (N);
9121 pragma Assert (Is_Floating_Point_Type (Etype (N)));
9122 Expand_Convert_Fixed_To_Float (N);
9127 -- Case of conversions to a fixed-point type
9129 -- These conversions require special expansion and processing, found in
9130 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
9131 -- since from a semantic point of view, these are simple integer
9132 -- conversions, which do not need further processing.
9134 elsif Is_Fixed_Point_Type (Target_Type)
9135 and then not Conversion_OK (N)
9137 if Is_Integer_Type (Operand_Type) then
9138 Expand_Convert_Integer_To_Fixed (N);
9141 pragma Assert (Is_Floating_Point_Type (Operand_Type));
9142 Expand_Convert_Float_To_Fixed (N);
9146 -- Case of float-to-integer conversions
9148 -- We also handle float-to-fixed conversions with Conversion_OK set
9149 -- since semantically the fixed-point target is treated as though it
9150 -- were an integer in such cases.
9152 elsif Is_Floating_Point_Type (Operand_Type)
9154 (Is_Integer_Type (Target_Type)
9156 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
9158 -- One more check here, gcc is still not able to do conversions of
9159 -- this type with proper overflow checking, and so gigi is doing an
9160 -- approximation of what is required by doing floating-point compares
9161 -- with the end-point. But that can lose precision in some cases, and
9162 -- give a wrong result. Converting the operand to Universal_Real is
9163 -- helpful, but still does not catch all cases with 64-bit integers
9164 -- on targets with only 64-bit floats.
9166 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
9167 -- Can this code be removed ???
9169 if Do_Range_Check (Operand) then
9171 Make_Type_Conversion (Loc,
9173 New_Occurrence_Of (Universal_Real, Loc),
9175 Relocate_Node (Operand)));
9177 Set_Etype (Operand, Universal_Real);
9178 Enable_Range_Check (Operand);
9179 Set_Do_Range_Check (Expression (Operand), False);
9182 -- Case of array conversions
9184 -- Expansion of array conversions, add required length/range checks but
9185 -- only do this if there is no change of representation. For handling of
9186 -- this case, see Handle_Changed_Representation.
9188 elsif Is_Array_Type (Target_Type) then
9189 if Is_Constrained (Target_Type) then
9190 Apply_Length_Check (Operand, Target_Type);
9192 Apply_Range_Check (Operand, Target_Type);
9195 Handle_Changed_Representation;
9197 -- Case of conversions of discriminated types
9199 -- Add required discriminant checks if target is constrained. Again this
9200 -- change is skipped if we have a change of representation.
9202 elsif Has_Discriminants (Target_Type)
9203 and then Is_Constrained (Target_Type)
9205 Apply_Discriminant_Check (Operand, Target_Type);
9206 Handle_Changed_Representation;
9208 -- Case of all other record conversions. The only processing required
9209 -- is to check for a change of representation requiring the special
9210 -- assignment processing.
9212 elsif Is_Record_Type (Target_Type) then
9214 -- Ada 2005 (AI-216): Program_Error is raised when converting from
9215 -- a derived Unchecked_Union type to an unconstrained type that is
9216 -- not Unchecked_Union if the operand lacks inferable discriminants.
9218 if Is_Derived_Type (Operand_Type)
9219 and then Is_Unchecked_Union (Base_Type (Operand_Type))
9220 and then not Is_Constrained (Target_Type)
9221 and then not Is_Unchecked_Union (Base_Type (Target_Type))
9222 and then not Has_Inferable_Discriminants (Operand)
9224 -- To prevent Gigi from generating illegal code, we generate a
9225 -- Program_Error node, but we give it the target type of the
9229 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
9230 Reason => PE_Unchecked_Union_Restriction);
9233 Set_Etype (PE, Target_Type);
9238 Handle_Changed_Representation;
9241 -- Case of conversions of enumeration types
9243 elsif Is_Enumeration_Type (Target_Type) then
9245 -- Special processing is required if there is a change of
9246 -- representation (from enumeration representation clauses).
9248 if not Same_Representation (Target_Type, Operand_Type) then
9250 -- Convert: x(y) to x'val (ytyp'val (y))
9253 Make_Attribute_Reference (Loc,
9254 Prefix => New_Occurrence_Of (Target_Type, Loc),
9255 Attribute_Name => Name_Val,
9256 Expressions => New_List (
9257 Make_Attribute_Reference (Loc,
9258 Prefix => New_Occurrence_Of (Operand_Type, Loc),
9259 Attribute_Name => Name_Pos,
9260 Expressions => New_List (Operand)))));
9262 Analyze_And_Resolve (N, Target_Type);
9265 -- Case of conversions to floating-point
9267 elsif Is_Floating_Point_Type (Target_Type) then
9271 -- At this stage, either the conversion node has been transformed into
9272 -- some other equivalent expression, or left as a conversion that can be
9273 -- handled by Gigi, in the following cases:
9275 -- Conversions with no change of representation or type
9277 -- Numeric conversions involving integer, floating- and fixed-point
9278 -- values. Fixed-point values are allowed only if Conversion_OK is
9279 -- set, i.e. if the fixed-point values are to be treated as integers.
9281 -- No other conversions should be passed to Gigi
9283 -- Check: are these rules stated in sinfo??? if so, why restate here???
9285 -- The only remaining step is to generate a range check if we still have
9286 -- a type conversion at this stage and Do_Range_Check is set. For now we
9287 -- do this only for conversions of discrete types.
9289 if Nkind (N) = N_Type_Conversion
9290 and then Is_Discrete_Type (Etype (N))
9293 Expr : constant Node_Id := Expression (N);
9298 if Do_Range_Check (Expr)
9299 and then Is_Discrete_Type (Etype (Expr))
9301 Set_Do_Range_Check (Expr, False);
9303 -- Before we do a range check, we have to deal with treating a
9304 -- fixed-point operand as an integer. The way we do this is
9305 -- simply to do an unchecked conversion to an appropriate
9306 -- integer type large enough to hold the result.
9308 -- This code is not active yet, because we are only dealing
9309 -- with discrete types so far ???
9311 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
9312 and then Treat_Fixed_As_Integer (Expr)
9314 Ftyp := Base_Type (Etype (Expr));
9316 if Esize (Ftyp) >= Esize (Standard_Integer) then
9317 Ityp := Standard_Long_Long_Integer;
9319 Ityp := Standard_Integer;
9322 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
9325 -- Reset overflow flag, since the range check will include
9326 -- dealing with possible overflow, and generate the check. If
9327 -- Address is either a source type or target type, suppress
9328 -- range check to avoid typing anomalies when it is a visible
9331 Set_Do_Overflow_Check (N, False);
9332 if not Is_Descendent_Of_Address (Etype (Expr))
9333 and then not Is_Descendent_Of_Address (Target_Type)
9335 Generate_Range_Check
9336 (Expr, Target_Type, CE_Range_Check_Failed);
9342 -- Final step, if the result is a type conversion involving Vax_Float
9343 -- types, then it is subject for further special processing.
9345 if Nkind (N) = N_Type_Conversion
9346 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
9348 Expand_Vax_Conversion (N);
9352 -- Here at end of processing
9355 -- Apply predicate check if required. Note that we can't just call
9356 -- Apply_Predicate_Check here, because the type looks right after
9357 -- the conversion and it would omit the check. The Comes_From_Source
9358 -- guard is necessary to prevent infinite recursions when we generate
9359 -- internal conversions for the purpose of checking predicates.
9361 if Present (Predicate_Function (Target_Type))
9362 and then Target_Type /= Operand_Type
9363 and then Comes_From_Source (N)
9366 New_Expr : constant Node_Id := Duplicate_Subexpr (N);
9369 -- Avoid infinite recursion on the subsequent expansion of
9370 -- of the copy of the original type conversion.
9372 Set_Comes_From_Source (New_Expr, False);
9373 Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr));
9376 end Expand_N_Type_Conversion;
9378 -----------------------------------
9379 -- Expand_N_Unchecked_Expression --
9380 -----------------------------------
9382 -- Remove the unchecked expression node from the tree. Its job was simply
9383 -- to make sure that its constituent expression was handled with checks
9384 -- off, and now that that is done, we can remove it from the tree, and
9385 -- indeed must, since Gigi does not expect to see these nodes.
9387 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
9388 Exp : constant Node_Id := Expression (N);
9390 Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
9392 end Expand_N_Unchecked_Expression;
9394 ----------------------------------------
9395 -- Expand_N_Unchecked_Type_Conversion --
9396 ----------------------------------------
9398 -- If this cannot be handled by Gigi and we haven't already made a
9399 -- temporary for it, do it now.
9401 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
9402 Target_Type : constant Entity_Id := Etype (N);
9403 Operand : constant Node_Id := Expression (N);
9404 Operand_Type : constant Entity_Id := Etype (Operand);
9407 -- Nothing at all to do if conversion is to the identical type so remove
9408 -- the conversion completely, it is useless, except that it may carry
9409 -- an Assignment_OK indication which must be propagated to the operand.
9411 if Operand_Type = Target_Type then
9413 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
9415 if Assignment_OK (N) then
9416 Set_Assignment_OK (Operand);
9419 Rewrite (N, Relocate_Node (Operand));
9423 -- If we have a conversion of a compile time known value to a target
9424 -- type and the value is in range of the target type, then we can simply
9425 -- replace the construct by an integer literal of the correct type. We
9426 -- only apply this to integer types being converted. Possibly it may
9427 -- apply in other cases, but it is too much trouble to worry about.
9429 -- Note that we do not do this transformation if the Kill_Range_Check
9430 -- flag is set, since then the value may be outside the expected range.
9431 -- This happens in the Normalize_Scalars case.
9433 -- We also skip this if either the target or operand type is biased
9434 -- because in this case, the unchecked conversion is supposed to
9435 -- preserve the bit pattern, not the integer value.
9437 if Is_Integer_Type (Target_Type)
9438 and then not Has_Biased_Representation (Target_Type)
9439 and then Is_Integer_Type (Operand_Type)
9440 and then not Has_Biased_Representation (Operand_Type)
9441 and then Compile_Time_Known_Value (Operand)
9442 and then not Kill_Range_Check (N)
9445 Val : constant Uint := Expr_Value (Operand);
9448 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
9450 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
9452 Val >= Expr_Value (Type_Low_Bound (Target_Type))
9454 Val <= Expr_Value (Type_High_Bound (Target_Type))
9456 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
9458 -- If Address is the target type, just set the type to avoid a
9459 -- spurious type error on the literal when Address is a visible
9462 if Is_Descendent_Of_Address (Target_Type) then
9463 Set_Etype (N, Target_Type);
9465 Analyze_And_Resolve (N, Target_Type);
9473 -- Nothing to do if conversion is safe
9475 if Safe_Unchecked_Type_Conversion (N) then
9479 -- Otherwise force evaluation unless Assignment_OK flag is set (this
9480 -- flag indicates ??? -- more comments needed here)
9482 if Assignment_OK (N) then
9485 Force_Evaluation (N);
9487 end Expand_N_Unchecked_Type_Conversion;
9489 ----------------------------
9490 -- Expand_Record_Equality --
9491 ----------------------------
9493 -- For non-variant records, Equality is expanded when needed into:
9495 -- and then Lhs.Discr1 = Rhs.Discr1
9497 -- and then Lhs.Discrn = Rhs.Discrn
9498 -- and then Lhs.Cmp1 = Rhs.Cmp1
9500 -- and then Lhs.Cmpn = Rhs.Cmpn
9502 -- The expression is folded by the back-end for adjacent fields. This
9503 -- function is called for tagged record in only one occasion: for imple-
9504 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
9505 -- otherwise the primitive "=" is used directly.
9507 function Expand_Record_Equality
9512 Bodies : List_Id) return Node_Id
9514 Loc : constant Source_Ptr := Sloc (Nod);
9519 First_Time : Boolean := True;
9521 function Suitable_Element (C : Entity_Id) return Entity_Id;
9522 -- Return the first field to compare beginning with C, skipping the
9523 -- inherited components.
9525 ----------------------
9526 -- Suitable_Element --
9527 ----------------------
9529 function Suitable_Element (C : Entity_Id) return Entity_Id is
9534 elsif Ekind (C) /= E_Discriminant
9535 and then Ekind (C) /= E_Component
9537 return Suitable_Element (Next_Entity (C));
9539 elsif Is_Tagged_Type (Typ)
9540 and then C /= Original_Record_Component (C)
9542 return Suitable_Element (Next_Entity (C));
9544 elsif Chars (C) = Name_uTag then
9545 return Suitable_Element (Next_Entity (C));
9547 -- The .NET/JVM version of type Root_Controlled contains two fields
9548 -- which should not be considered part of the object. To achieve
9549 -- proper equiality between two controlled objects on .NET/JVM, skip
9550 -- field _parent whenever it is of type Root_Controlled.
9552 elsif Chars (C) = Name_uParent
9553 and then VM_Target /= No_VM
9554 and then Etype (C) = RTE (RE_Root_Controlled)
9556 return Suitable_Element (Next_Entity (C));
9558 elsif Is_Interface (Etype (C)) then
9559 return Suitable_Element (Next_Entity (C));
9564 end Suitable_Element;
9566 -- Start of processing for Expand_Record_Equality
9569 -- Generates the following code: (assuming that Typ has one Discr and
9570 -- component C2 is also a record)
9573 -- and then Lhs.Discr1 = Rhs.Discr1
9574 -- and then Lhs.C1 = Rhs.C1
9575 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
9577 -- and then Lhs.Cmpn = Rhs.Cmpn
9579 Result := New_Reference_To (Standard_True, Loc);
9580 C := Suitable_Element (First_Entity (Typ));
9581 while Present (C) loop
9589 First_Time := False;
9593 New_Lhs := New_Copy_Tree (Lhs);
9594 New_Rhs := New_Copy_Tree (Rhs);
9598 Expand_Composite_Equality (Nod, Etype (C),
9600 Make_Selected_Component (Loc,
9602 Selector_Name => New_Reference_To (C, Loc)),
9604 Make_Selected_Component (Loc,
9606 Selector_Name => New_Reference_To (C, Loc)),
9609 -- If some (sub)component is an unchecked_union, the whole
9610 -- operation will raise program error.
9612 if Nkind (Check) = N_Raise_Program_Error then
9614 Set_Etype (Result, Standard_Boolean);
9619 Left_Opnd => Result,
9620 Right_Opnd => Check);
9624 C := Suitable_Element (Next_Entity (C));
9628 end Expand_Record_Equality;
9630 ---------------------------
9631 -- Expand_Set_Membership --
9632 ---------------------------
9634 procedure Expand_Set_Membership (N : Node_Id) is
9635 Lop : constant Node_Id := Left_Opnd (N);
9639 function Make_Cond (Alt : Node_Id) return Node_Id;
9640 -- If the alternative is a subtype mark, create a simple membership
9641 -- test. Otherwise create an equality test for it.
9647 function Make_Cond (Alt : Node_Id) return Node_Id is
9649 L : constant Node_Id := New_Copy (Lop);
9650 R : constant Node_Id := Relocate_Node (Alt);
9653 if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
9654 or else Nkind (Alt) = N_Range
9657 Make_In (Sloc (Alt),
9662 Make_Op_Eq (Sloc (Alt),
9670 -- Start of processing for Expand_Set_Membership
9673 Remove_Side_Effects (Lop);
9675 Alt := Last (Alternatives (N));
9676 Res := Make_Cond (Alt);
9679 while Present (Alt) loop
9681 Make_Or_Else (Sloc (Alt),
9682 Left_Opnd => Make_Cond (Alt),
9688 Analyze_And_Resolve (N, Standard_Boolean);
9689 end Expand_Set_Membership;
9691 -----------------------------------
9692 -- Expand_Short_Circuit_Operator --
9693 -----------------------------------
9695 -- Deal with special expansion if actions are present for the right operand
9696 -- and deal with optimizing case of arguments being True or False. We also
9697 -- deal with the special case of non-standard boolean values.
9699 procedure Expand_Short_Circuit_Operator (N : Node_Id) is
9700 Loc : constant Source_Ptr := Sloc (N);
9701 Typ : constant Entity_Id := Etype (N);
9702 Left : constant Node_Id := Left_Opnd (N);
9703 Right : constant Node_Id := Right_Opnd (N);
9704 LocR : constant Source_Ptr := Sloc (Right);
9707 Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
9708 Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
9709 -- If Left = Shortcut_Value then Right need not be evaluated
9711 function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
9712 -- For Opnd a boolean expression, return a Boolean expression equivalent
9713 -- to Opnd /= Shortcut_Value.
9715 --------------------
9716 -- Make_Test_Expr --
9717 --------------------
9719 function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
9721 if Shortcut_Value then
9722 return Make_Op_Not (Sloc (Opnd), Opnd);
9729 -- Entity for a temporary variable holding the value of the operator,
9730 -- used for expansion in the case where actions are present.
9732 -- Start of processing for Expand_Short_Circuit_Operator
9735 -- Deal with non-standard booleans
9737 if Is_Boolean_Type (Typ) then
9738 Adjust_Condition (Left);
9739 Adjust_Condition (Right);
9740 Set_Etype (N, Standard_Boolean);
9743 -- Check for cases where left argument is known to be True or False
9745 if Compile_Time_Known_Value (Left) then
9747 -- Mark SCO for left condition as compile time known
9749 if Generate_SCO and then Comes_From_Source (Left) then
9750 Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
9753 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
9754 -- Any actions associated with Right will be executed unconditionally
9755 -- and can thus be inserted into the tree unconditionally.
9757 if Expr_Value_E (Left) /= Shortcut_Ent then
9758 if Present (Actions (N)) then
9759 Insert_Actions (N, Actions (N));
9764 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
9765 -- In this case we can forget the actions associated with Right,
9766 -- since they will never be executed.
9769 Kill_Dead_Code (Right);
9770 Kill_Dead_Code (Actions (N));
9771 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9774 Adjust_Result_Type (N, Typ);
9778 -- If Actions are present for the right operand, we have to do some
9779 -- special processing. We can't just let these actions filter back into
9780 -- code preceding the short circuit (which is what would have happened
9781 -- if we had not trapped them in the short-circuit form), since they
9782 -- must only be executed if the right operand of the short circuit is
9783 -- executed and not otherwise.
9785 -- the temporary variable C.
9787 if Present (Actions (N)) then
9788 Actlist := Actions (N);
9790 -- The old approach is to expand:
9792 -- left AND THEN right
9796 -- C : Boolean := False;
9804 -- and finally rewrite the operator into a reference to C. Similarly
9805 -- for left OR ELSE right, with negated values. Note that this
9806 -- rewrite causes some difficulties for coverage analysis because
9807 -- of the introduction of the new variable C, which obscures the
9808 -- structure of the test.
9810 -- We use this "old approach" if use of N_Expression_With_Actions
9811 -- is False (see description in Opt of when this is or is not set).
9813 if not Use_Expression_With_Actions then
9814 Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
9817 Make_Object_Declaration (Loc,
9818 Defining_Identifier =>
9820 Object_Definition =>
9821 New_Occurrence_Of (Standard_Boolean, Loc),
9823 New_Occurrence_Of (Shortcut_Ent, Loc)));
9826 Make_Implicit_If_Statement (Right,
9827 Condition => Make_Test_Expr (Right),
9828 Then_Statements => New_List (
9829 Make_Assignment_Statement (LocR,
9830 Name => New_Occurrence_Of (Op_Var, LocR),
9833 (Boolean_Literals (not Shortcut_Value), LocR)))));
9836 Make_Implicit_If_Statement (Left,
9837 Condition => Make_Test_Expr (Left),
9838 Then_Statements => Actlist));
9840 Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
9841 Analyze_And_Resolve (N, Standard_Boolean);
9843 -- The new approach, activated for now by the use of debug flag
9844 -- -gnatd.X is to use the new Expression_With_Actions node for the
9845 -- right operand of the short-circuit form. This should solve the
9846 -- traceability problems for coverage analysis.
9850 Make_Expression_With_Actions (LocR,
9851 Expression => Relocate_Node (Right),
9852 Actions => Actlist));
9853 Set_Actions (N, No_List);
9854 Analyze_And_Resolve (Right, Standard_Boolean);
9857 Adjust_Result_Type (N, Typ);
9861 -- No actions present, check for cases of right argument True/False
9863 if Compile_Time_Known_Value (Right) then
9865 -- Mark SCO for left condition as compile time known
9867 if Generate_SCO and then Comes_From_Source (Right) then
9868 Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
9871 -- Change (Left and then True), (Left or else False) to Left.
9872 -- Note that we know there are no actions associated with the right
9873 -- operand, since we just checked for this case above.
9875 if Expr_Value_E (Right) /= Shortcut_Ent then
9878 -- Change (Left and then False), (Left or else True) to Right,
9879 -- making sure to preserve any side effects associated with the Left
9883 Remove_Side_Effects (Left);
9884 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9888 Adjust_Result_Type (N, Typ);
9889 end Expand_Short_Circuit_Operator;
9891 -------------------------------------
9892 -- Fixup_Universal_Fixed_Operation --
9893 -------------------------------------
9895 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
9896 Conv : constant Node_Id := Parent (N);
9899 -- We must have a type conversion immediately above us
9901 pragma Assert (Nkind (Conv) = N_Type_Conversion);
9903 -- Normally the type conversion gives our target type. The exception
9904 -- occurs in the case of the Round attribute, where the conversion
9905 -- will be to universal real, and our real type comes from the Round
9906 -- attribute (as well as an indication that we must round the result)
9908 if Nkind (Parent (Conv)) = N_Attribute_Reference
9909 and then Attribute_Name (Parent (Conv)) = Name_Round
9911 Set_Etype (N, Etype (Parent (Conv)));
9912 Set_Rounded_Result (N);
9914 -- Normal case where type comes from conversion above us
9917 Set_Etype (N, Etype (Conv));
9919 end Fixup_Universal_Fixed_Operation;
9921 ---------------------------------
9922 -- Has_Inferable_Discriminants --
9923 ---------------------------------
9925 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
9927 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
9928 -- Determines whether the left-most prefix of a selected component is a
9929 -- formal parameter in a subprogram. Assumes N is a selected component.
9931 --------------------------------
9932 -- Prefix_Is_Formal_Parameter --
9933 --------------------------------
9935 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
9936 Sel_Comp : Node_Id := N;
9939 -- Move to the left-most prefix by climbing up the tree
9941 while Present (Parent (Sel_Comp))
9942 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
9944 Sel_Comp := Parent (Sel_Comp);
9947 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
9948 end Prefix_Is_Formal_Parameter;
9950 -- Start of processing for Has_Inferable_Discriminants
9953 -- For identifiers and indexed components, it is sufficient to have a
9954 -- constrained Unchecked_Union nominal subtype.
9956 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
9957 return Is_Unchecked_Union (Base_Type (Etype (N)))
9959 Is_Constrained (Etype (N));
9961 -- For selected components, the subtype of the selector must be a
9962 -- constrained Unchecked_Union. If the component is subject to a
9963 -- per-object constraint, then the enclosing object must have inferable
9966 elsif Nkind (N) = N_Selected_Component then
9967 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
9969 -- A small hack. If we have a per-object constrained selected
9970 -- component of a formal parameter, return True since we do not
9971 -- know the actual parameter association yet.
9973 if Prefix_Is_Formal_Parameter (N) then
9977 -- Otherwise, check the enclosing object and the selector
9979 return Has_Inferable_Discriminants (Prefix (N))
9981 Has_Inferable_Discriminants (Selector_Name (N));
9984 -- The call to Has_Inferable_Discriminants will determine whether
9985 -- the selector has a constrained Unchecked_Union nominal type.
9987 return Has_Inferable_Discriminants (Selector_Name (N));
9989 -- A qualified expression has inferable discriminants if its subtype
9990 -- mark is a constrained Unchecked_Union subtype.
9992 elsif Nkind (N) = N_Qualified_Expression then
9993 return Is_Unchecked_Union (Subtype_Mark (N))
9995 Is_Constrained (Subtype_Mark (N));
10000 end Has_Inferable_Discriminants;
10002 -------------------------------
10003 -- Insert_Dereference_Action --
10004 -------------------------------
10006 procedure Insert_Dereference_Action (N : Node_Id) is
10007 Loc : constant Source_Ptr := Sloc (N);
10008 Typ : constant Entity_Id := Etype (N);
10009 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
10010 Pnod : constant Node_Id := Parent (N);
10012 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
10013 -- Return true if type of P is derived from Checked_Pool;
10015 -----------------------------
10016 -- Is_Checked_Storage_Pool --
10017 -----------------------------
10019 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
10028 while T /= Etype (T) loop
10029 if Is_RTE (T, RE_Checked_Pool) then
10037 end Is_Checked_Storage_Pool;
10039 -- Start of processing for Insert_Dereference_Action
10042 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
10044 if not (Is_Checked_Storage_Pool (Pool)
10045 and then Comes_From_Source (Original_Node (Pnod)))
10051 Make_Procedure_Call_Statement (Loc,
10052 Name => New_Reference_To (
10053 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
10055 Parameter_Associations => New_List (
10059 New_Reference_To (Pool, Loc),
10061 -- Storage_Address. We use the attribute Pool_Address, which uses
10062 -- the pointer itself to find the address of the object, and which
10063 -- handles unconstrained arrays properly by computing the address
10064 -- of the template. i.e. the correct address of the corresponding
10067 Make_Attribute_Reference (Loc,
10068 Prefix => Duplicate_Subexpr_Move_Checks (N),
10069 Attribute_Name => Name_Pool_Address),
10071 -- Size_In_Storage_Elements
10073 Make_Op_Divide (Loc,
10075 Make_Attribute_Reference (Loc,
10077 Make_Explicit_Dereference (Loc,
10078 Duplicate_Subexpr_Move_Checks (N)),
10079 Attribute_Name => Name_Size),
10081 Make_Integer_Literal (Loc, System_Storage_Unit)),
10085 Make_Attribute_Reference (Loc,
10087 Make_Explicit_Dereference (Loc,
10088 Duplicate_Subexpr_Move_Checks (N)),
10089 Attribute_Name => Name_Alignment))));
10092 when RE_Not_Available =>
10094 end Insert_Dereference_Action;
10096 --------------------------------
10097 -- Integer_Promotion_Possible --
10098 --------------------------------
10100 function Integer_Promotion_Possible (N : Node_Id) return Boolean is
10101 Operand : constant Node_Id := Expression (N);
10102 Operand_Type : constant Entity_Id := Etype (Operand);
10103 Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
10106 pragma Assert (Nkind (N) = N_Type_Conversion);
10110 -- We only do the transformation for source constructs. We assume
10111 -- that the expander knows what it is doing when it generates code.
10113 Comes_From_Source (N)
10115 -- If the operand type is Short_Integer or Short_Short_Integer,
10116 -- then we will promote to Integer, which is available on all
10117 -- targets, and is sufficient to ensure no intermediate overflow.
10118 -- Furthermore it is likely to be as efficient or more efficient
10119 -- than using the smaller type for the computation so we do this
10120 -- unconditionally.
10123 (Root_Operand_Type = Base_Type (Standard_Short_Integer)
10125 Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
10127 -- Test for interesting operation, which includes addition,
10128 -- division, exponentiation, multiplication, subtraction, absolute
10129 -- value and unary negation. Unary "+" is omitted since it is a
10130 -- no-op and thus can't overflow.
10132 and then Nkind_In (Operand, N_Op_Abs,
10139 end Integer_Promotion_Possible;
10141 ------------------------------
10142 -- Make_Array_Comparison_Op --
10143 ------------------------------
10145 -- This is a hand-coded expansion of the following generic function:
10148 -- type elem is (<>);
10149 -- type index is (<>);
10150 -- type a is array (index range <>) of elem;
10152 -- function Gnnn (X : a; Y: a) return boolean is
10153 -- J : index := Y'first;
10156 -- if X'length = 0 then
10159 -- elsif Y'length = 0 then
10163 -- for I in X'range loop
10164 -- if X (I) = Y (J) then
10165 -- if J = Y'last then
10168 -- J := index'succ (J);
10172 -- return X (I) > Y (J);
10176 -- return X'length > Y'length;
10180 -- Note that since we are essentially doing this expansion by hand, we
10181 -- do not need to generate an actual or formal generic part, just the
10182 -- instantiated function itself.
10184 function Make_Array_Comparison_Op
10186 Nod : Node_Id) return Node_Id
10188 Loc : constant Source_Ptr := Sloc (Nod);
10190 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
10191 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
10192 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
10193 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10195 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
10197 Loop_Statement : Node_Id;
10198 Loop_Body : Node_Id;
10200 Inner_If : Node_Id;
10201 Final_Expr : Node_Id;
10202 Func_Body : Node_Id;
10203 Func_Name : Entity_Id;
10209 -- if J = Y'last then
10212 -- J := index'succ (J);
10216 Make_Implicit_If_Statement (Nod,
10219 Left_Opnd => New_Reference_To (J, Loc),
10221 Make_Attribute_Reference (Loc,
10222 Prefix => New_Reference_To (Y, Loc),
10223 Attribute_Name => Name_Last)),
10225 Then_Statements => New_List (
10226 Make_Exit_Statement (Loc)),
10230 Make_Assignment_Statement (Loc,
10231 Name => New_Reference_To (J, Loc),
10233 Make_Attribute_Reference (Loc,
10234 Prefix => New_Reference_To (Index, Loc),
10235 Attribute_Name => Name_Succ,
10236 Expressions => New_List (New_Reference_To (J, Loc))))));
10238 -- if X (I) = Y (J) then
10241 -- return X (I) > Y (J);
10245 Make_Implicit_If_Statement (Nod,
10249 Make_Indexed_Component (Loc,
10250 Prefix => New_Reference_To (X, Loc),
10251 Expressions => New_List (New_Reference_To (I, Loc))),
10254 Make_Indexed_Component (Loc,
10255 Prefix => New_Reference_To (Y, Loc),
10256 Expressions => New_List (New_Reference_To (J, Loc)))),
10258 Then_Statements => New_List (Inner_If),
10260 Else_Statements => New_List (
10261 Make_Simple_Return_Statement (Loc,
10265 Make_Indexed_Component (Loc,
10266 Prefix => New_Reference_To (X, Loc),
10267 Expressions => New_List (New_Reference_To (I, Loc))),
10270 Make_Indexed_Component (Loc,
10271 Prefix => New_Reference_To (Y, Loc),
10272 Expressions => New_List (
10273 New_Reference_To (J, Loc)))))));
10275 -- for I in X'range loop
10280 Make_Implicit_Loop_Statement (Nod,
10281 Identifier => Empty,
10283 Iteration_Scheme =>
10284 Make_Iteration_Scheme (Loc,
10285 Loop_Parameter_Specification =>
10286 Make_Loop_Parameter_Specification (Loc,
10287 Defining_Identifier => I,
10288 Discrete_Subtype_Definition =>
10289 Make_Attribute_Reference (Loc,
10290 Prefix => New_Reference_To (X, Loc),
10291 Attribute_Name => Name_Range))),
10293 Statements => New_List (Loop_Body));
10295 -- if X'length = 0 then
10297 -- elsif Y'length = 0 then
10300 -- for ... loop ... end loop;
10301 -- return X'length > Y'length;
10305 Make_Attribute_Reference (Loc,
10306 Prefix => New_Reference_To (X, Loc),
10307 Attribute_Name => Name_Length);
10310 Make_Attribute_Reference (Loc,
10311 Prefix => New_Reference_To (Y, Loc),
10312 Attribute_Name => Name_Length);
10316 Left_Opnd => Length1,
10317 Right_Opnd => Length2);
10320 Make_Implicit_If_Statement (Nod,
10324 Make_Attribute_Reference (Loc,
10325 Prefix => New_Reference_To (X, Loc),
10326 Attribute_Name => Name_Length),
10328 Make_Integer_Literal (Loc, 0)),
10332 Make_Simple_Return_Statement (Loc,
10333 Expression => New_Reference_To (Standard_False, Loc))),
10335 Elsif_Parts => New_List (
10336 Make_Elsif_Part (Loc,
10340 Make_Attribute_Reference (Loc,
10341 Prefix => New_Reference_To (Y, Loc),
10342 Attribute_Name => Name_Length),
10344 Make_Integer_Literal (Loc, 0)),
10348 Make_Simple_Return_Statement (Loc,
10349 Expression => New_Reference_To (Standard_True, Loc))))),
10351 Else_Statements => New_List (
10353 Make_Simple_Return_Statement (Loc,
10354 Expression => Final_Expr)));
10358 Formals := New_List (
10359 Make_Parameter_Specification (Loc,
10360 Defining_Identifier => X,
10361 Parameter_Type => New_Reference_To (Typ, Loc)),
10363 Make_Parameter_Specification (Loc,
10364 Defining_Identifier => Y,
10365 Parameter_Type => New_Reference_To (Typ, Loc)));
10367 -- function Gnnn (...) return boolean is
10368 -- J : index := Y'first;
10373 Func_Name := Make_Temporary (Loc, 'G');
10376 Make_Subprogram_Body (Loc,
10378 Make_Function_Specification (Loc,
10379 Defining_Unit_Name => Func_Name,
10380 Parameter_Specifications => Formals,
10381 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
10383 Declarations => New_List (
10384 Make_Object_Declaration (Loc,
10385 Defining_Identifier => J,
10386 Object_Definition => New_Reference_To (Index, Loc),
10388 Make_Attribute_Reference (Loc,
10389 Prefix => New_Reference_To (Y, Loc),
10390 Attribute_Name => Name_First))),
10392 Handled_Statement_Sequence =>
10393 Make_Handled_Sequence_Of_Statements (Loc,
10394 Statements => New_List (If_Stat)));
10397 end Make_Array_Comparison_Op;
10399 ---------------------------
10400 -- Make_Boolean_Array_Op --
10401 ---------------------------
10403 -- For logical operations on boolean arrays, expand in line the following,
10404 -- replacing 'and' with 'or' or 'xor' where needed:
10406 -- function Annn (A : typ; B: typ) return typ is
10409 -- for J in A'range loop
10410 -- C (J) := A (J) op B (J);
10415 -- Here typ is the boolean array type
10417 function Make_Boolean_Array_Op
10419 N : Node_Id) return Node_Id
10421 Loc : constant Source_Ptr := Sloc (N);
10423 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
10424 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
10425 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
10426 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10434 Func_Name : Entity_Id;
10435 Func_Body : Node_Id;
10436 Loop_Statement : Node_Id;
10440 Make_Indexed_Component (Loc,
10441 Prefix => New_Reference_To (A, Loc),
10442 Expressions => New_List (New_Reference_To (J, Loc)));
10445 Make_Indexed_Component (Loc,
10446 Prefix => New_Reference_To (B, Loc),
10447 Expressions => New_List (New_Reference_To (J, Loc)));
10450 Make_Indexed_Component (Loc,
10451 Prefix => New_Reference_To (C, Loc),
10452 Expressions => New_List (New_Reference_To (J, Loc)));
10454 if Nkind (N) = N_Op_And then
10458 Right_Opnd => B_J);
10460 elsif Nkind (N) = N_Op_Or then
10464 Right_Opnd => B_J);
10470 Right_Opnd => B_J);
10474 Make_Implicit_Loop_Statement (N,
10475 Identifier => Empty,
10477 Iteration_Scheme =>
10478 Make_Iteration_Scheme (Loc,
10479 Loop_Parameter_Specification =>
10480 Make_Loop_Parameter_Specification (Loc,
10481 Defining_Identifier => J,
10482 Discrete_Subtype_Definition =>
10483 Make_Attribute_Reference (Loc,
10484 Prefix => New_Reference_To (A, Loc),
10485 Attribute_Name => Name_Range))),
10487 Statements => New_List (
10488 Make_Assignment_Statement (Loc,
10490 Expression => Op)));
10492 Formals := New_List (
10493 Make_Parameter_Specification (Loc,
10494 Defining_Identifier => A,
10495 Parameter_Type => New_Reference_To (Typ, Loc)),
10497 Make_Parameter_Specification (Loc,
10498 Defining_Identifier => B,
10499 Parameter_Type => New_Reference_To (Typ, Loc)));
10501 Func_Name := Make_Temporary (Loc, 'A');
10502 Set_Is_Inlined (Func_Name);
10505 Make_Subprogram_Body (Loc,
10507 Make_Function_Specification (Loc,
10508 Defining_Unit_Name => Func_Name,
10509 Parameter_Specifications => Formals,
10510 Result_Definition => New_Reference_To (Typ, Loc)),
10512 Declarations => New_List (
10513 Make_Object_Declaration (Loc,
10514 Defining_Identifier => C,
10515 Object_Definition => New_Reference_To (Typ, Loc))),
10517 Handled_Statement_Sequence =>
10518 Make_Handled_Sequence_Of_Statements (Loc,
10519 Statements => New_List (
10521 Make_Simple_Return_Statement (Loc,
10522 Expression => New_Reference_To (C, Loc)))));
10525 end Make_Boolean_Array_Op;
10527 --------------------------------
10528 -- Optimize_Length_Comparison --
10529 --------------------------------
10531 procedure Optimize_Length_Comparison (N : Node_Id) is
10532 Loc : constant Source_Ptr := Sloc (N);
10533 Typ : constant Entity_Id := Etype (N);
10538 -- First and Last attribute reference nodes, which end up as left and
10539 -- right operands of the optimized result.
10542 -- True for comparison operand of zero
10545 -- Comparison operand, set only if Is_Zero is false
10548 -- Entity whose length is being compared
10551 -- Integer_Literal node for length attribute expression, or Empty
10552 -- if there is no such expression present.
10555 -- Type of array index to which 'Length is applied
10557 Op : Node_Kind := Nkind (N);
10558 -- Kind of comparison operator, gets flipped if operands backwards
10560 function Is_Optimizable (N : Node_Id) return Boolean;
10561 -- Tests N to see if it is an optimizable comparison value (defined as
10562 -- constant zero or one, or something else where the value is known to
10563 -- be positive and in the range of 32-bits, and where the corresponding
10564 -- Length value is also known to be 32-bits. If result is true, sets
10565 -- Is_Zero, Ityp, and Comp accordingly.
10567 function Is_Entity_Length (N : Node_Id) return Boolean;
10568 -- Tests if N is a length attribute applied to a simple entity. If so,
10569 -- returns True, and sets Ent to the entity, and Index to the integer
10570 -- literal provided as an attribute expression, or to Empty if none.
10571 -- Also returns True if the expression is a generated type conversion
10572 -- whose expression is of the desired form. This latter case arises
10573 -- when Apply_Universal_Integer_Attribute_Check installs a conversion
10574 -- to check for being in range, which is not needed in this context.
10575 -- Returns False if neither condition holds.
10577 function Prepare_64 (N : Node_Id) return Node_Id;
10578 -- Given a discrete expression, returns a Long_Long_Integer typed
10579 -- expression representing the underlying value of the expression.
10580 -- This is done with an unchecked conversion to the result type. We
10581 -- use unchecked conversion to handle the enumeration type case.
10583 ----------------------
10584 -- Is_Entity_Length --
10585 ----------------------
10587 function Is_Entity_Length (N : Node_Id) return Boolean is
10589 if Nkind (N) = N_Attribute_Reference
10590 and then Attribute_Name (N) = Name_Length
10591 and then Is_Entity_Name (Prefix (N))
10593 Ent := Entity (Prefix (N));
10595 if Present (Expressions (N)) then
10596 Index := First (Expressions (N));
10603 elsif Nkind (N) = N_Type_Conversion
10604 and then not Comes_From_Source (N)
10606 return Is_Entity_Length (Expression (N));
10611 end Is_Entity_Length;
10613 --------------------
10614 -- Is_Optimizable --
10615 --------------------
10617 function Is_Optimizable (N : Node_Id) return Boolean is
10625 if Compile_Time_Known_Value (N) then
10626 Val := Expr_Value (N);
10628 if Val = Uint_0 then
10633 elsif Val = Uint_1 then
10640 -- Here we have to make sure of being within 32-bits
10642 Determine_Range (N, OK, Lo, Hi, Assume_Valid => True);
10645 or else Lo < Uint_1
10646 or else Hi > UI_From_Int (Int'Last)
10651 -- Comparison value was within range, so now we must check the index
10652 -- value to make sure it is also within 32-bits.
10654 Indx := First_Index (Etype (Ent));
10656 if Present (Index) then
10657 for J in 2 .. UI_To_Int (Intval (Index)) loop
10662 Ityp := Etype (Indx);
10664 if Esize (Ityp) > 32 then
10671 end Is_Optimizable;
10677 function Prepare_64 (N : Node_Id) return Node_Id is
10679 return Unchecked_Convert_To (Standard_Long_Long_Integer, N);
10682 -- Start of processing for Optimize_Length_Comparison
10685 -- Nothing to do if not a comparison
10687 if Op not in N_Op_Compare then
10691 -- Nothing to do if special -gnatd.P debug flag set
10693 if Debug_Flag_Dot_PP then
10697 -- Ent'Length op 0/1
10699 if Is_Entity_Length (Left_Opnd (N))
10700 and then Is_Optimizable (Right_Opnd (N))
10704 -- 0/1 op Ent'Length
10706 elsif Is_Entity_Length (Right_Opnd (N))
10707 and then Is_Optimizable (Left_Opnd (N))
10709 -- Flip comparison to opposite sense
10712 when N_Op_Lt => Op := N_Op_Gt;
10713 when N_Op_Le => Op := N_Op_Ge;
10714 when N_Op_Gt => Op := N_Op_Lt;
10715 when N_Op_Ge => Op := N_Op_Le;
10716 when others => null;
10719 -- Else optimization not possible
10725 -- Fall through if we will do the optimization
10727 -- Cases to handle:
10729 -- X'Length = 0 => X'First > X'Last
10730 -- X'Length = 1 => X'First = X'Last
10731 -- X'Length = n => X'First + (n - 1) = X'Last
10733 -- X'Length /= 0 => X'First <= X'Last
10734 -- X'Length /= 1 => X'First /= X'Last
10735 -- X'Length /= n => X'First + (n - 1) /= X'Last
10737 -- X'Length >= 0 => always true, warn
10738 -- X'Length >= 1 => X'First <= X'Last
10739 -- X'Length >= n => X'First + (n - 1) <= X'Last
10741 -- X'Length > 0 => X'First <= X'Last
10742 -- X'Length > 1 => X'First < X'Last
10743 -- X'Length > n => X'First + (n - 1) < X'Last
10745 -- X'Length <= 0 => X'First > X'Last (warn, could be =)
10746 -- X'Length <= 1 => X'First >= X'Last
10747 -- X'Length <= n => X'First + (n - 1) >= X'Last
10749 -- X'Length < 0 => always false (warn)
10750 -- X'Length < 1 => X'First > X'Last
10751 -- X'Length < n => X'First + (n - 1) > X'Last
10753 -- Note: for the cases of n (not constant 0,1), we require that the
10754 -- corresponding index type be integer or shorter (i.e. not 64-bit),
10755 -- and the same for the comparison value. Then we do the comparison
10756 -- using 64-bit arithmetic (actually long long integer), so that we
10757 -- cannot have overflow intefering with the result.
10759 -- First deal with warning cases
10768 Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc)));
10769 Analyze_And_Resolve (N, Typ);
10770 Warn_On_Known_Condition (N);
10777 Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc)));
10778 Analyze_And_Resolve (N, Typ);
10779 Warn_On_Known_Condition (N);
10783 if Constant_Condition_Warnings
10784 and then Comes_From_Source (Original_Node (N))
10786 Error_Msg_N ("could replace by ""'=""?", N);
10796 -- Build the First reference we will use
10799 Make_Attribute_Reference (Loc,
10800 Prefix => New_Occurrence_Of (Ent, Loc),
10801 Attribute_Name => Name_First);
10803 if Present (Index) then
10804 Set_Expressions (Left, New_List (New_Copy (Index)));
10807 -- If general value case, then do the addition of (n - 1), and
10808 -- also add the needed conversions to type Long_Long_Integer.
10810 if Present (Comp) then
10813 Left_Opnd => Prepare_64 (Left),
10815 Make_Op_Subtract (Loc,
10816 Left_Opnd => Prepare_64 (Comp),
10817 Right_Opnd => Make_Integer_Literal (Loc, 1)));
10820 -- Build the Last reference we will use
10823 Make_Attribute_Reference (Loc,
10824 Prefix => New_Occurrence_Of (Ent, Loc),
10825 Attribute_Name => Name_Last);
10827 if Present (Index) then
10828 Set_Expressions (Right, New_List (New_Copy (Index)));
10831 -- If general operand, convert Last reference to Long_Long_Integer
10833 if Present (Comp) then
10834 Right := Prepare_64 (Right);
10837 -- Check for cases to optimize
10839 -- X'Length = 0 => X'First > X'Last
10840 -- X'Length < 1 => X'First > X'Last
10841 -- X'Length < n => X'First + (n - 1) > X'Last
10843 if (Is_Zero and then Op = N_Op_Eq)
10844 or else (not Is_Zero and then Op = N_Op_Lt)
10849 Right_Opnd => Right);
10851 -- X'Length = 1 => X'First = X'Last
10852 -- X'Length = n => X'First + (n - 1) = X'Last
10854 elsif not Is_Zero and then Op = N_Op_Eq then
10858 Right_Opnd => Right);
10860 -- X'Length /= 0 => X'First <= X'Last
10861 -- X'Length > 0 => X'First <= X'Last
10863 elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then
10867 Right_Opnd => Right);
10869 -- X'Length /= 1 => X'First /= X'Last
10870 -- X'Length /= n => X'First + (n - 1) /= X'Last
10872 elsif not Is_Zero and then Op = N_Op_Ne then
10876 Right_Opnd => Right);
10878 -- X'Length >= 1 => X'First <= X'Last
10879 -- X'Length >= n => X'First + (n - 1) <= X'Last
10881 elsif not Is_Zero and then Op = N_Op_Ge then
10885 Right_Opnd => Right);
10887 -- X'Length > 1 => X'First < X'Last
10888 -- X'Length > n => X'First + (n = 1) < X'Last
10890 elsif not Is_Zero and then Op = N_Op_Gt then
10894 Right_Opnd => Right);
10896 -- X'Length <= 1 => X'First >= X'Last
10897 -- X'Length <= n => X'First + (n - 1) >= X'Last
10899 elsif not Is_Zero and then Op = N_Op_Le then
10903 Right_Opnd => Right);
10905 -- Should not happen at this stage
10908 raise Program_Error;
10911 -- Rewrite and finish up
10913 Rewrite (N, Result);
10914 Analyze_And_Resolve (N, Typ);
10916 end Optimize_Length_Comparison;
10918 ------------------------
10919 -- Rewrite_Comparison --
10920 ------------------------
10922 procedure Rewrite_Comparison (N : Node_Id) is
10923 Warning_Generated : Boolean := False;
10924 -- Set to True if first pass with Assume_Valid generates a warning in
10925 -- which case we skip the second pass to avoid warning overloaded.
10928 -- Set to Standard_True or Standard_False
10931 if Nkind (N) = N_Type_Conversion then
10932 Rewrite_Comparison (Expression (N));
10935 elsif Nkind (N) not in N_Op_Compare then
10939 -- Now start looking at the comparison in detail. We potentially go
10940 -- through this loop twice. The first time, Assume_Valid is set False
10941 -- in the call to Compile_Time_Compare. If this call results in a
10942 -- clear result of always True or Always False, that's decisive and
10943 -- we are done. Otherwise we repeat the processing with Assume_Valid
10944 -- set to True to generate additional warnings. We can skip that step
10945 -- if Constant_Condition_Warnings is False.
10947 for AV in False .. True loop
10949 Typ : constant Entity_Id := Etype (N);
10950 Op1 : constant Node_Id := Left_Opnd (N);
10951 Op2 : constant Node_Id := Right_Opnd (N);
10953 Res : constant Compare_Result :=
10954 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
10955 -- Res indicates if compare outcome can be compile time determined
10957 True_Result : Boolean;
10958 False_Result : Boolean;
10961 case N_Op_Compare (Nkind (N)) is
10963 True_Result := Res = EQ;
10964 False_Result := Res = LT or else Res = GT or else Res = NE;
10967 True_Result := Res in Compare_GE;
10968 False_Result := Res = LT;
10971 and then Constant_Condition_Warnings
10972 and then Comes_From_Source (Original_Node (N))
10973 and then Nkind (Original_Node (N)) = N_Op_Ge
10974 and then not In_Instance
10975 and then Is_Integer_Type (Etype (Left_Opnd (N)))
10976 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
10979 ("can never be greater than, could replace by ""'=""?", N);
10980 Warning_Generated := True;
10984 True_Result := Res = GT;
10985 False_Result := Res in Compare_LE;
10988 True_Result := Res = LT;
10989 False_Result := Res in Compare_GE;
10992 True_Result := Res in Compare_LE;
10993 False_Result := Res = GT;
10996 and then Constant_Condition_Warnings
10997 and then Comes_From_Source (Original_Node (N))
10998 and then Nkind (Original_Node (N)) = N_Op_Le
10999 and then not In_Instance
11000 and then Is_Integer_Type (Etype (Left_Opnd (N)))
11001 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
11004 ("can never be less than, could replace by ""'=""?", N);
11005 Warning_Generated := True;
11009 True_Result := Res = NE or else Res = GT or else Res = LT;
11010 False_Result := Res = EQ;
11013 -- If this is the first iteration, then we actually convert the
11014 -- comparison into True or False, if the result is certain.
11017 if True_Result or False_Result then
11018 if True_Result then
11019 Result := Standard_True;
11021 Result := Standard_False;
11026 New_Occurrence_Of (Result, Sloc (N))));
11027 Analyze_And_Resolve (N, Typ);
11028 Warn_On_Known_Condition (N);
11032 -- If this is the second iteration (AV = True), and the original
11033 -- node comes from source and we are not in an instance, then give
11034 -- a warning if we know result would be True or False. Note: we
11035 -- know Constant_Condition_Warnings is set if we get here.
11037 elsif Comes_From_Source (Original_Node (N))
11038 and then not In_Instance
11040 if True_Result then
11042 ("condition can only be False if invalid values present?",
11044 elsif False_Result then
11046 ("condition can only be True if invalid values present?",
11052 -- Skip second iteration if not warning on constant conditions or
11053 -- if the first iteration already generated a warning of some kind or
11054 -- if we are in any case assuming all values are valid (so that the
11055 -- first iteration took care of the valid case).
11057 exit when not Constant_Condition_Warnings;
11058 exit when Warning_Generated;
11059 exit when Assume_No_Invalid_Values;
11061 end Rewrite_Comparison;
11063 ----------------------------
11064 -- Safe_In_Place_Array_Op --
11065 ----------------------------
11067 function Safe_In_Place_Array_Op
11070 Op2 : Node_Id) return Boolean
11072 Target : Entity_Id;
11074 function Is_Safe_Operand (Op : Node_Id) return Boolean;
11075 -- Operand is safe if it cannot overlap part of the target of the
11076 -- operation. If the operand and the target are identical, the operand
11077 -- is safe. The operand can be empty in the case of negation.
11079 function Is_Unaliased (N : Node_Id) return Boolean;
11080 -- Check that N is a stand-alone entity
11086 function Is_Unaliased (N : Node_Id) return Boolean is
11090 and then No (Address_Clause (Entity (N)))
11091 and then No (Renamed_Object (Entity (N)));
11094 ---------------------
11095 -- Is_Safe_Operand --
11096 ---------------------
11098 function Is_Safe_Operand (Op : Node_Id) return Boolean is
11103 elsif Is_Entity_Name (Op) then
11104 return Is_Unaliased (Op);
11106 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
11107 return Is_Unaliased (Prefix (Op));
11109 elsif Nkind (Op) = N_Slice then
11111 Is_Unaliased (Prefix (Op))
11112 and then Entity (Prefix (Op)) /= Target;
11114 elsif Nkind (Op) = N_Op_Not then
11115 return Is_Safe_Operand (Right_Opnd (Op));
11120 end Is_Safe_Operand;
11122 -- Start of processing for Is_Safe_In_Place_Array_Op
11125 -- Skip this processing if the component size is different from system
11126 -- storage unit (since at least for NOT this would cause problems).
11128 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
11131 -- Cannot do in place stuff on VM_Target since cannot pass addresses
11133 elsif VM_Target /= No_VM then
11136 -- Cannot do in place stuff if non-standard Boolean representation
11138 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
11141 elsif not Is_Unaliased (Lhs) then
11145 Target := Entity (Lhs);
11146 return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
11148 end Safe_In_Place_Array_Op;
11150 -----------------------
11151 -- Tagged_Membership --
11152 -----------------------
11154 -- There are two different cases to consider depending on whether the right
11155 -- operand is a class-wide type or not. If not we just compare the actual
11156 -- tag of the left expr to the target type tag:
11158 -- Left_Expr.Tag = Right_Type'Tag;
11160 -- If it is a class-wide type we use the RT function CW_Membership which is
11161 -- usually implemented by looking in the ancestor tables contained in the
11162 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
11164 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
11165 -- function IW_Membership which is usually implemented by looking in the
11166 -- table of abstract interface types plus the ancestor table contained in
11167 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
11169 procedure Tagged_Membership
11171 SCIL_Node : out Node_Id;
11172 Result : out Node_Id)
11174 Left : constant Node_Id := Left_Opnd (N);
11175 Right : constant Node_Id := Right_Opnd (N);
11176 Loc : constant Source_Ptr := Sloc (N);
11178 Full_R_Typ : Entity_Id;
11179 Left_Type : Entity_Id;
11180 New_Node : Node_Id;
11181 Right_Type : Entity_Id;
11185 SCIL_Node := Empty;
11187 -- Handle entities from the limited view
11189 Left_Type := Available_View (Etype (Left));
11190 Right_Type := Available_View (Etype (Right));
11192 -- In the case where the type is an access type, the test is applied
11193 -- using the designated types (needed in Ada 2012 for implicit anonymous
11194 -- access conversions, for AI05-0149).
11196 if Is_Access_Type (Right_Type) then
11197 Left_Type := Designated_Type (Left_Type);
11198 Right_Type := Designated_Type (Right_Type);
11201 if Is_Class_Wide_Type (Left_Type) then
11202 Left_Type := Root_Type (Left_Type);
11205 if Is_Class_Wide_Type (Right_Type) then
11206 Full_R_Typ := Underlying_Type (Root_Type (Right_Type));
11208 Full_R_Typ := Underlying_Type (Right_Type);
11212 Make_Selected_Component (Loc,
11213 Prefix => Relocate_Node (Left),
11215 New_Reference_To (First_Tag_Component (Left_Type), Loc));
11217 if Is_Class_Wide_Type (Right_Type) then
11219 -- No need to issue a run-time check if we statically know that the
11220 -- result of this membership test is always true. For example,
11221 -- considering the following declarations:
11223 -- type Iface is interface;
11224 -- type T is tagged null record;
11225 -- type DT is new T and Iface with null record;
11230 -- These membership tests are always true:
11233 -- Obj2 in T'Class;
11234 -- Obj2 in Iface'Class;
11236 -- We do not need to handle cases where the membership is illegal.
11239 -- Obj1 in DT'Class; -- Compile time error
11240 -- Obj1 in Iface'Class; -- Compile time error
11242 if not Is_Class_Wide_Type (Left_Type)
11243 and then (Is_Ancestor (Etype (Right_Type), Left_Type,
11244 Use_Full_View => True)
11245 or else (Is_Interface (Etype (Right_Type))
11246 and then Interface_Present_In_Ancestor
11248 Iface => Etype (Right_Type))))
11250 Result := New_Reference_To (Standard_True, Loc);
11254 -- Ada 2005 (AI-251): Class-wide applied to interfaces
11256 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
11258 -- Support to: "Iface_CW_Typ in Typ'Class"
11260 or else Is_Interface (Left_Type)
11262 -- Issue error if IW_Membership operation not available in a
11263 -- configurable run time setting.
11265 if not RTE_Available (RE_IW_Membership) then
11267 ("dynamic membership test on interface types", N);
11273 Make_Function_Call (Loc,
11274 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
11275 Parameter_Associations => New_List (
11276 Make_Attribute_Reference (Loc,
11278 Attribute_Name => Name_Address),
11280 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))),
11283 -- Ada 95: Normal case
11286 Build_CW_Membership (Loc,
11287 Obj_Tag_Node => Obj_Tag,
11290 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc),
11292 New_Node => New_Node);
11294 -- Generate the SCIL node for this class-wide membership test.
11295 -- Done here because the previous call to Build_CW_Membership
11296 -- relocates Obj_Tag.
11298 if Generate_SCIL then
11299 SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
11300 Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
11301 Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
11304 Result := New_Node;
11307 -- Right_Type is not a class-wide type
11310 -- No need to check the tag of the object if Right_Typ is abstract
11312 if Is_Abstract_Type (Right_Type) then
11313 Result := New_Reference_To (Standard_False, Loc);
11318 Left_Opnd => Obj_Tag,
11321 (Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc));
11324 end Tagged_Membership;
11326 ------------------------------
11327 -- Unary_Op_Validity_Checks --
11328 ------------------------------
11330 procedure Unary_Op_Validity_Checks (N : Node_Id) is
11332 if Validity_Checks_On and Validity_Check_Operands then
11333 Ensure_Valid (Right_Opnd (N));
11335 end Unary_Op_Validity_Checks;