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 Ada2012 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
3531 Pool := Associated_Storage_Pool (Root_Type (PtrT));
3532 Set_Storage_Pool (N, Pool);
3534 if Present (Pool) then
3535 if Is_RTE (Pool, RE_SS_Pool) then
3536 if VM_Target = No_VM then
3537 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3540 elsif Is_Class_Wide_Type (Etype (Pool)) then
3541 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3544 Set_Procedure_To_Call (N,
3545 Find_Prim_Op (Etype (Pool), Name_Allocate));
3549 -- Under certain circumstances we can replace an allocator by an access
3550 -- to statically allocated storage. The conditions, as noted in AARM
3551 -- 3.10 (10c) are as follows:
3553 -- Size and initial value is known at compile time
3554 -- Access type is access-to-constant
3556 -- The allocator is not part of a constraint on a record component,
3557 -- because in that case the inserted actions are delayed until the
3558 -- record declaration is fully analyzed, which is too late for the
3559 -- analysis of the rewritten allocator.
3561 if Is_Access_Constant (PtrT)
3562 and then Nkind (Expression (N)) = N_Qualified_Expression
3563 and then Compile_Time_Known_Value (Expression (Expression (N)))
3564 and then Size_Known_At_Compile_Time
3565 (Etype (Expression (Expression (N))))
3566 and then not Is_Record_Type (Current_Scope)
3568 -- Here we can do the optimization. For the allocator
3572 -- We insert an object declaration
3574 -- Tnn : aliased x := y;
3576 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3577 -- marked as requiring static allocation.
3579 Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
3580 Desig := Subtype_Mark (Expression (N));
3582 -- If context is constrained, use constrained subtype directly,
3583 -- so that the constant is not labelled as having a nominally
3584 -- unconstrained subtype.
3586 if Entity (Desig) = Base_Type (Dtyp) then
3587 Desig := New_Occurrence_Of (Dtyp, Loc);
3591 Make_Object_Declaration (Loc,
3592 Defining_Identifier => Temp,
3593 Aliased_Present => True,
3594 Constant_Present => Is_Access_Constant (PtrT),
3595 Object_Definition => Desig,
3596 Expression => Expression (Expression (N))));
3599 Make_Attribute_Reference (Loc,
3600 Prefix => New_Occurrence_Of (Temp, Loc),
3601 Attribute_Name => Name_Unrestricted_Access));
3603 Analyze_And_Resolve (N, PtrT);
3605 -- We set the variable as statically allocated, since we don't want
3606 -- it going on the stack of the current procedure!
3608 Set_Is_Statically_Allocated (Temp);
3612 -- Same if the allocator is an access discriminant for a local object:
3613 -- instead of an allocator we create a local value and constrain the
3614 -- enclosing object with the corresponding access attribute.
3616 if Is_Static_Coextension (N) then
3617 Rewrite_Coextension (N);
3621 -- Check for size too large, we do this because the back end misses
3622 -- proper checks here and can generate rubbish allocation calls when
3623 -- we are near the limit. We only do this for the 32-bit address case
3624 -- since that is from a practical point of view where we see a problem.
3626 if System_Address_Size = 32
3627 and then not Storage_Checks_Suppressed (PtrT)
3628 and then not Storage_Checks_Suppressed (Dtyp)
3629 and then not Storage_Checks_Suppressed (Etyp)
3631 -- The check we want to generate should look like
3633 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
3634 -- raise Storage_Error;
3637 -- where 3.5 gigabytes is a constant large enough to accommodate any
3638 -- reasonable request for. But we can't do it this way because at
3639 -- least at the moment we don't compute this attribute right, and
3640 -- can silently give wrong results when the result gets large. Since
3641 -- this is all about large results, that's bad, so instead we only
3642 -- apply the check for constrained arrays, and manually compute the
3643 -- value of the attribute ???
3645 if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
3647 Make_Raise_Storage_Error (Loc,
3650 Left_Opnd => Size_In_Storage_Elements (Etyp),
3652 Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))),
3653 Reason => SE_Object_Too_Large));
3657 -- Handle case of qualified expression (other than optimization above)
3658 -- First apply constraint checks, because the bounds or discriminants
3659 -- in the aggregate might not match the subtype mark in the allocator.
3661 if Nkind (Expression (N)) = N_Qualified_Expression then
3662 Apply_Constraint_Check
3663 (Expression (Expression (N)), Etype (Expression (N)));
3665 Expand_Allocator_Expression (N);
3669 -- If the allocator is for a type which requires initialization, and
3670 -- there is no initial value (i.e. operand is a subtype indication
3671 -- rather than a qualified expression), then we must generate a call to
3672 -- the initialization routine using an expressions action node:
3674 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3676 -- Here ptr_T is the pointer type for the allocator, and T is the
3677 -- subtype of the allocator. A special case arises if the designated
3678 -- type of the access type is a task or contains tasks. In this case
3679 -- the call to Init (Temp.all ...) is replaced by code that ensures
3680 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3681 -- for details). In addition, if the type T is a task T, then the
3682 -- first argument to Init must be converted to the task record type.
3685 T : constant Entity_Id := Entity (Expression (N));
3691 Init_Arg1 : Node_Id;
3692 Temp_Decl : Node_Id;
3693 Temp_Type : Entity_Id;
3696 if No_Initialization (N) then
3698 -- Even though this might be a simple allocation, create a custom
3699 -- Allocate if the context requires it. Since .NET/JVM compilers
3700 -- do not support pools, this step is skipped.
3702 if VM_Target = No_VM
3703 and then Present (Finalization_Master (PtrT))
3705 Build_Allocate_Deallocate_Proc
3707 Is_Allocate => True);
3710 -- Case of no initialization procedure present
3712 elsif not Has_Non_Null_Base_Init_Proc (T) then
3714 -- Case of simple initialization required
3716 if Needs_Simple_Initialization (T) then
3717 Check_Restriction (No_Default_Initialization, N);
3718 Rewrite (Expression (N),
3719 Make_Qualified_Expression (Loc,
3720 Subtype_Mark => New_Occurrence_Of (T, Loc),
3721 Expression => Get_Simple_Init_Val (T, N)));
3723 Analyze_And_Resolve (Expression (Expression (N)), T);
3724 Analyze_And_Resolve (Expression (N), T);
3725 Set_Paren_Count (Expression (Expression (N)), 1);
3726 Expand_N_Allocator (N);
3728 -- No initialization required
3734 -- Case of initialization procedure present, must be called
3737 Check_Restriction (No_Default_Initialization, N);
3739 if not Restriction_Active (No_Default_Initialization) then
3740 Init := Base_Init_Proc (T);
3742 Temp := Make_Temporary (Loc, 'P');
3744 -- Construct argument list for the initialization routine call
3747 Make_Explicit_Dereference (Loc,
3749 New_Reference_To (Temp, Loc));
3751 Set_Assignment_OK (Init_Arg1);
3754 -- The initialization procedure expects a specific type. if the
3755 -- context is access to class wide, indicate that the object
3756 -- being allocated has the right specific type.
3758 if Is_Class_Wide_Type (Dtyp) then
3759 Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1);
3762 -- If designated type is a concurrent type or if it is private
3763 -- type whose definition is a concurrent type, the first
3764 -- argument in the Init routine has to be unchecked conversion
3765 -- to the corresponding record type. If the designated type is
3766 -- a derived type, also convert the argument to its root type.
3768 if Is_Concurrent_Type (T) then
3770 Unchecked_Convert_To (
3771 Corresponding_Record_Type (T), Init_Arg1);
3773 elsif Is_Private_Type (T)
3774 and then Present (Full_View (T))
3775 and then Is_Concurrent_Type (Full_View (T))
3778 Unchecked_Convert_To
3779 (Corresponding_Record_Type (Full_View (T)), Init_Arg1);
3781 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3783 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3786 Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1);
3787 Set_Etype (Init_Arg1, Ftyp);
3791 Args := New_List (Init_Arg1);
3793 -- For the task case, pass the Master_Id of the access type as
3794 -- the value of the _Master parameter, and _Chain as the value
3795 -- of the _Chain parameter (_Chain will be defined as part of
3796 -- the generated code for the allocator).
3798 -- In Ada 2005, the context may be a function that returns an
3799 -- anonymous access type. In that case the Master_Id has been
3800 -- created when expanding the function declaration.
3802 if Has_Task (T) then
3803 if No (Master_Id (Base_Type (PtrT))) then
3805 -- The designated type was an incomplete type, and the
3806 -- access type did not get expanded. Salvage it now.
3808 if not Restriction_Active (No_Task_Hierarchy) then
3809 pragma Assert (Present (Parent (Base_Type (PtrT))));
3810 Expand_N_Full_Type_Declaration
3811 (Parent (Base_Type (PtrT)));
3815 -- If the context of the allocator is a declaration or an
3816 -- assignment, we can generate a meaningful image for it,
3817 -- even though subsequent assignments might remove the
3818 -- connection between task and entity. We build this image
3819 -- when the left-hand side is a simple variable, a simple
3820 -- indexed assignment or a simple selected component.
3822 if Nkind (Parent (N)) = N_Assignment_Statement then
3824 Nam : constant Node_Id := Name (Parent (N));
3827 if Is_Entity_Name (Nam) then
3829 Build_Task_Image_Decls
3832 (Entity (Nam), Sloc (Nam)), T);
3834 elsif Nkind_In (Nam, N_Indexed_Component,
3835 N_Selected_Component)
3836 and then Is_Entity_Name (Prefix (Nam))
3839 Build_Task_Image_Decls
3840 (Loc, Nam, Etype (Prefix (Nam)));
3842 Decls := Build_Task_Image_Decls (Loc, T, T);
3846 elsif Nkind (Parent (N)) = N_Object_Declaration then
3848 Build_Task_Image_Decls
3849 (Loc, Defining_Identifier (Parent (N)), T);
3852 Decls := Build_Task_Image_Decls (Loc, T, T);
3855 if Restriction_Active (No_Task_Hierarchy) then
3857 New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
3861 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3864 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3866 Decl := Last (Decls);
3868 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3870 -- Has_Task is false, Decls not used
3876 -- Add discriminants if discriminated type
3879 Dis : Boolean := False;
3883 if Has_Discriminants (T) then
3887 elsif Is_Private_Type (T)
3888 and then Present (Full_View (T))
3889 and then Has_Discriminants (Full_View (T))
3892 Typ := Full_View (T);
3897 -- If the allocated object will be constrained by the
3898 -- default values for discriminants, then build a subtype
3899 -- with those defaults, and change the allocated subtype
3900 -- to that. Note that this happens in fewer cases in Ada
3903 if not Is_Constrained (Typ)
3904 and then Present (Discriminant_Default_Value
3905 (First_Discriminant (Typ)))
3906 and then (Ada_Version < Ada_2005
3908 not Has_Constrained_Partial_View (Typ))
3910 Typ := Build_Default_Subtype (Typ, N);
3911 Set_Expression (N, New_Reference_To (Typ, Loc));
3914 Discr := First_Elmt (Discriminant_Constraint (Typ));
3915 while Present (Discr) loop
3916 Nod := Node (Discr);
3917 Append (New_Copy_Tree (Node (Discr)), Args);
3919 -- AI-416: when the discriminant constraint is an
3920 -- anonymous access type make sure an accessibility
3921 -- check is inserted if necessary (3.10.2(22.q/2))
3923 if Ada_Version >= Ada_2005
3925 Ekind (Etype (Nod)) = E_Anonymous_Access_Type
3927 Apply_Accessibility_Check
3928 (Nod, Typ, Insert_Node => Nod);
3936 -- We set the allocator as analyzed so that when we analyze the
3937 -- expression actions node, we do not get an unwanted recursive
3938 -- expansion of the allocator expression.
3940 Set_Analyzed (N, True);
3941 Nod := Relocate_Node (N);
3943 -- Here is the transformation:
3944 -- input: new Ctrl_Typ
3945 -- output: Temp : constant Ctrl_Typ_Ptr := new Ctrl_Typ;
3946 -- Ctrl_TypIP (Temp.all, ...);
3947 -- [Deep_]Initialize (Temp.all);
3949 -- Here Ctrl_Typ_Ptr is the pointer type for the allocator, and
3950 -- is the subtype of the allocator.
3953 Make_Object_Declaration (Loc,
3954 Defining_Identifier => Temp,
3955 Constant_Present => True,
3956 Object_Definition => New_Reference_To (Temp_Type, Loc),
3959 Set_Assignment_OK (Temp_Decl);
3960 Insert_Action (N, Temp_Decl, Suppress => All_Checks);
3962 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
3964 -- If the designated type is a task type or contains tasks,
3965 -- create block to activate created tasks, and insert
3966 -- declaration for Task_Image variable ahead of call.
3968 if Has_Task (T) then
3970 L : constant List_Id := New_List;
3973 Build_Task_Allocate_Block (L, Nod, Args);
3975 Insert_List_Before (First (Declarations (Blk)), Decls);
3976 Insert_Actions (N, L);
3981 Make_Procedure_Call_Statement (Loc,
3982 Name => New_Reference_To (Init, Loc),
3983 Parameter_Associations => Args));
3986 if Needs_Finalization (T) then
3989 -- [Deep_]Initialize (Init_Arg1);
3993 (Obj_Ref => New_Copy_Tree (Init_Arg1),
3996 if Present (Finalization_Master (PtrT)) then
3998 -- Special processing for .NET/JVM, the allocated object
3999 -- is attached to the finalization master. Generate:
4001 -- Attach (<PtrT>FM, Root_Controlled_Ptr (Init_Arg1));
4003 -- Types derived from [Limited_]Controlled are the only
4004 -- ones considered since they have fields Prev and Next.
4006 if VM_Target /= No_VM then
4007 if Is_Controlled (T) then
4010 (Obj_Ref => New_Copy_Tree (Init_Arg1),
4014 -- Default case, generate:
4016 -- Set_Finalize_Address
4017 -- (<PtrT>FM, <T>FD'Unrestricted_Access);
4019 -- Do not generate this call in the following cases:
4021 -- * Alfa mode - the call is useless and results in
4022 -- unwanted expansion.
4024 -- * CodePeer mode - TSS primitive Finalize_Address is
4025 -- not created in this mode.
4028 and then not CodePeer_Mode
4031 Make_Set_Finalize_Address_Call
4039 Rewrite (N, New_Reference_To (Temp, Loc));
4040 Analyze_And_Resolve (N, PtrT);
4045 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
4046 -- object that has been rewritten as a reference, we displace "this"
4047 -- to reference properly its secondary dispatch table.
4049 if Nkind (N) = N_Identifier
4050 and then Is_Interface (Dtyp)
4052 Displace_Allocator_Pointer (N);
4056 when RE_Not_Available =>
4058 end Expand_N_Allocator;
4060 -----------------------
4061 -- Expand_N_And_Then --
4062 -----------------------
4064 procedure Expand_N_And_Then (N : Node_Id)
4065 renames Expand_Short_Circuit_Operator;
4067 ------------------------------
4068 -- Expand_N_Case_Expression --
4069 ------------------------------
4071 procedure Expand_N_Case_Expression (N : Node_Id) is
4072 Loc : constant Source_Ptr := Sloc (N);
4073 Typ : constant Entity_Id := Etype (N);
4085 -- case X is when A => AX, when B => BX ...
4100 -- However, this expansion is wrong for limited types, and also
4101 -- wrong for unconstrained types (since the bounds may not be the
4102 -- same in all branches). Furthermore it involves an extra copy
4103 -- for large objects. So we take care of this by using the following
4104 -- modified expansion for non-scalar types:
4107 -- type Pnn is access all typ;
4111 -- T := AX'Unrestricted_Access;
4113 -- T := BX'Unrestricted_Access;
4119 Make_Case_Statement (Loc,
4120 Expression => Expression (N),
4121 Alternatives => New_List);
4123 Actions := New_List;
4127 if Is_Scalar_Type (Typ) then
4131 Pnn := Make_Temporary (Loc, 'P');
4133 Make_Full_Type_Declaration (Loc,
4134 Defining_Identifier => Pnn,
4136 Make_Access_To_Object_Definition (Loc,
4137 All_Present => True,
4138 Subtype_Indication =>
4139 New_Reference_To (Typ, Loc))));
4143 Tnn := Make_Temporary (Loc, 'T');
4145 Make_Object_Declaration (Loc,
4146 Defining_Identifier => Tnn,
4147 Object_Definition => New_Occurrence_Of (Ttyp, Loc)));
4149 -- Now process the alternatives
4151 Alt := First (Alternatives (N));
4152 while Present (Alt) loop
4154 Aexp : Node_Id := Expression (Alt);
4155 Aloc : constant Source_Ptr := Sloc (Aexp);
4159 -- As described above, take Unrestricted_Access for case of non-
4160 -- scalar types, to avoid big copies, and special cases.
4162 if not Is_Scalar_Type (Typ) then
4164 Make_Attribute_Reference (Aloc,
4165 Prefix => Relocate_Node (Aexp),
4166 Attribute_Name => Name_Unrestricted_Access);
4170 Make_Assignment_Statement (Aloc,
4171 Name => New_Occurrence_Of (Tnn, Loc),
4172 Expression => Aexp));
4174 -- Propagate declarations inserted in the node by Insert_Actions
4175 -- (for example, temporaries generated to remove side effects).
4176 -- These actions must remain attached to the alternative, given
4177 -- that they are generated by the corresponding expression.
4179 if Present (Sinfo.Actions (Alt)) then
4180 Prepend_List (Sinfo.Actions (Alt), Stats);
4184 (Alternatives (Cstmt),
4185 Make_Case_Statement_Alternative (Sloc (Alt),
4186 Discrete_Choices => Discrete_Choices (Alt),
4187 Statements => Stats));
4193 Append_To (Actions, Cstmt);
4195 -- Construct and return final expression with actions
4197 if Is_Scalar_Type (Typ) then
4198 Fexp := New_Occurrence_Of (Tnn, Loc);
4201 Make_Explicit_Dereference (Loc,
4202 Prefix => New_Occurrence_Of (Tnn, Loc));
4206 Make_Expression_With_Actions (Loc,
4208 Actions => Actions));
4210 Analyze_And_Resolve (N, Typ);
4211 end Expand_N_Case_Expression;
4213 -------------------------------------
4214 -- Expand_N_Conditional_Expression --
4215 -------------------------------------
4217 -- Deal with limited types and expression actions
4219 procedure Expand_N_Conditional_Expression (N : Node_Id) is
4220 Loc : constant Source_Ptr := Sloc (N);
4221 Cond : constant Node_Id := First (Expressions (N));
4222 Thenx : constant Node_Id := Next (Cond);
4223 Elsex : constant Node_Id := Next (Thenx);
4224 Typ : constant Entity_Id := Etype (N);
4235 -- Fold at compile time if condition known. We have already folded
4236 -- static conditional expressions, but it is possible to fold any
4237 -- case in which the condition is known at compile time, even though
4238 -- the result is non-static.
4240 -- Note that we don't do the fold of such cases in Sem_Elab because
4241 -- it can cause infinite loops with the expander adding a conditional
4242 -- expression, and Sem_Elab circuitry removing it repeatedly.
4244 if Compile_Time_Known_Value (Cond) then
4245 if Is_True (Expr_Value (Cond)) then
4247 Actions := Then_Actions (N);
4250 Actions := Else_Actions (N);
4255 if Present (Actions) then
4257 -- If we are not allowed to use Expression_With_Actions, just skip
4258 -- the optimization, it is not critical for correctness.
4260 if not Use_Expression_With_Actions then
4261 goto Skip_Optimization;
4265 Make_Expression_With_Actions (Loc,
4266 Expression => Relocate_Node (Expr),
4267 Actions => Actions));
4268 Analyze_And_Resolve (N, Typ);
4271 Rewrite (N, Relocate_Node (Expr));
4274 -- Note that the result is never static (legitimate cases of static
4275 -- conditional expressions were folded in Sem_Eval).
4277 Set_Is_Static_Expression (N, False);
4281 <<Skip_Optimization>>
4283 -- If the type is limited or unconstrained, we expand as follows to
4284 -- avoid any possibility of improper copies.
4286 -- Note: it may be possible to avoid this special processing if the
4287 -- back end uses its own mechanisms for handling by-reference types ???
4289 -- type Ptr is access all Typ;
4293 -- Cnn := then-expr'Unrestricted_Access;
4296 -- Cnn := else-expr'Unrestricted_Access;
4299 -- and replace the conditional expression by a reference to Cnn.all.
4301 -- This special case can be skipped if the back end handles limited
4302 -- types properly and ensures that no incorrect copies are made.
4304 if Is_By_Reference_Type (Typ)
4305 and then not Back_End_Handles_Limited_Types
4307 Cnn := Make_Temporary (Loc, 'C', N);
4310 Make_Full_Type_Declaration (Loc,
4311 Defining_Identifier =>
4312 Make_Temporary (Loc, 'A'),
4314 Make_Access_To_Object_Definition (Loc,
4315 All_Present => True,
4316 Subtype_Indication => New_Reference_To (Typ, Loc)));
4318 Insert_Action (N, P_Decl);
4321 Make_Object_Declaration (Loc,
4322 Defining_Identifier => Cnn,
4323 Object_Definition =>
4324 New_Occurrence_Of (Defining_Identifier (P_Decl), Loc));
4327 Make_Implicit_If_Statement (N,
4328 Condition => Relocate_Node (Cond),
4330 Then_Statements => New_List (
4331 Make_Assignment_Statement (Sloc (Thenx),
4332 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4334 Make_Attribute_Reference (Loc,
4335 Attribute_Name => Name_Unrestricted_Access,
4336 Prefix => Relocate_Node (Thenx)))),
4338 Else_Statements => New_List (
4339 Make_Assignment_Statement (Sloc (Elsex),
4340 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4342 Make_Attribute_Reference (Loc,
4343 Attribute_Name => Name_Unrestricted_Access,
4344 Prefix => Relocate_Node (Elsex)))));
4347 Make_Explicit_Dereference (Loc,
4348 Prefix => New_Occurrence_Of (Cnn, Loc));
4350 -- For other types, we only need to expand if there are other actions
4351 -- associated with either branch.
4353 elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
4355 -- We have two approaches to handling this. If we are allowed to use
4356 -- N_Expression_With_Actions, then we can just wrap the actions into
4357 -- the appropriate expression.
4359 if Use_Expression_With_Actions then
4360 if Present (Then_Actions (N)) then
4362 Make_Expression_With_Actions (Sloc (Thenx),
4363 Actions => Then_Actions (N),
4364 Expression => Relocate_Node (Thenx)));
4365 Set_Then_Actions (N, No_List);
4366 Analyze_And_Resolve (Thenx, Typ);
4369 if Present (Else_Actions (N)) then
4371 Make_Expression_With_Actions (Sloc (Elsex),
4372 Actions => Else_Actions (N),
4373 Expression => Relocate_Node (Elsex)));
4374 Set_Else_Actions (N, No_List);
4375 Analyze_And_Resolve (Elsex, Typ);
4380 -- if we can't use N_Expression_With_Actions nodes, then we insert
4381 -- the following sequence of actions (using Insert_Actions):
4386 -- Cnn := then-expr;
4392 -- and replace the conditional expression by a reference to Cnn
4395 Cnn := Make_Temporary (Loc, 'C', N);
4398 Make_Object_Declaration (Loc,
4399 Defining_Identifier => Cnn,
4400 Object_Definition => New_Occurrence_Of (Typ, Loc));
4403 Make_Implicit_If_Statement (N,
4404 Condition => Relocate_Node (Cond),
4406 Then_Statements => New_List (
4407 Make_Assignment_Statement (Sloc (Thenx),
4408 Name => New_Occurrence_Of (Cnn, Sloc (Thenx)),
4409 Expression => Relocate_Node (Thenx))),
4411 Else_Statements => New_List (
4412 Make_Assignment_Statement (Sloc (Elsex),
4413 Name => New_Occurrence_Of (Cnn, Sloc (Elsex)),
4414 Expression => Relocate_Node (Elsex))));
4416 Set_Assignment_OK (Name (First (Then_Statements (New_If))));
4417 Set_Assignment_OK (Name (First (Else_Statements (New_If))));
4419 New_N := New_Occurrence_Of (Cnn, Loc);
4422 -- If no actions then no expansion needed, gigi will handle it using
4423 -- the same approach as a C conditional expression.
4429 -- Fall through here for either the limited expansion, or the case of
4430 -- inserting actions for non-limited types. In both these cases, we must
4431 -- move the SLOC of the parent If statement to the newly created one and
4432 -- change it to the SLOC of the expression which, after expansion, will
4433 -- correspond to what is being evaluated.
4435 if Present (Parent (N))
4436 and then Nkind (Parent (N)) = N_If_Statement
4438 Set_Sloc (New_If, Sloc (Parent (N)));
4439 Set_Sloc (Parent (N), Loc);
4442 -- Make sure Then_Actions and Else_Actions are appropriately moved
4443 -- to the new if statement.
4445 if Present (Then_Actions (N)) then
4447 (First (Then_Statements (New_If)), Then_Actions (N));
4450 if Present (Else_Actions (N)) then
4452 (First (Else_Statements (New_If)), Else_Actions (N));
4455 Insert_Action (N, Decl);
4456 Insert_Action (N, New_If);
4458 Analyze_And_Resolve (N, Typ);
4459 end Expand_N_Conditional_Expression;
4461 -----------------------------------
4462 -- Expand_N_Explicit_Dereference --
4463 -----------------------------------
4465 procedure Expand_N_Explicit_Dereference (N : Node_Id) is
4467 -- Insert explicit dereference call for the checked storage pool case
4469 Insert_Dereference_Action (Prefix (N));
4470 end Expand_N_Explicit_Dereference;
4472 --------------------------------------
4473 -- Expand_N_Expression_With_Actions --
4474 --------------------------------------
4476 procedure Expand_N_Expression_With_Actions (N : Node_Id) is
4478 procedure Process_Transient_Object (Decl : Node_Id);
4479 -- Given the declaration of a controlled transient declared inside the
4480 -- Actions list of an Expression_With_Actions, generate all necessary
4481 -- types and hooks in order to properly finalize the transient. This
4482 -- mechanism works in conjunction with Build_Finalizer.
4484 ------------------------------
4485 -- Process_Transient_Object --
4486 ------------------------------
4488 procedure Process_Transient_Object (Decl : Node_Id) is
4490 function Find_Insertion_Node return Node_Id;
4491 -- Complex conditions in if statements may be converted into nested
4492 -- EWAs. In this case, any generated code must be inserted before the
4493 -- if statement to ensure proper visibility of the hook objects. This
4494 -- routine returns the top most short circuit operator or the parent
4495 -- of the EWA if no nesting was detected.
4497 -------------------------
4498 -- Find_Insertion_Node --
4499 -------------------------
4501 function Find_Insertion_Node return Node_Id is
4505 -- Climb up the branches of a complex condition
4508 while Nkind_In (Parent (Par), N_And_Then, N_Op_Not, N_Or_Else) loop
4509 Par := Parent (Par);
4513 end Find_Insertion_Node;
4517 Ins_Node : constant Node_Id := Find_Insertion_Node;
4518 Loc : constant Source_Ptr := Sloc (Decl);
4519 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
4520 Obj_Typ : constant Entity_Id := Etype (Obj_Id);
4521 Desig_Typ : Entity_Id;
4525 Temp_Decl : Node_Id;
4528 -- Start of processing for Process_Transient_Object
4531 -- Step 1: Create the access type which provides a reference to the
4532 -- transient object.
4534 if Is_Access_Type (Obj_Typ) then
4535 Desig_Typ := Directly_Designated_Type (Obj_Typ);
4537 Desig_Typ := Obj_Typ;
4541 -- Ann : access [all] <Desig_Typ>;
4543 Ptr_Id := Make_Temporary (Loc, 'A');
4546 Make_Full_Type_Declaration (Loc,
4547 Defining_Identifier => Ptr_Id,
4549 Make_Access_To_Object_Definition (Loc,
4551 Ekind (Obj_Typ) = E_General_Access_Type,
4552 Subtype_Indication => New_Reference_To (Desig_Typ, Loc)));
4554 Insert_Action (Ins_Node, Ptr_Decl);
4557 -- Step 2: Create a temporary which acts as a hook to the transient
4558 -- object. Generate:
4560 -- Temp : Ptr_Id := null;
4562 Temp_Id := Make_Temporary (Loc, 'T');
4565 Make_Object_Declaration (Loc,
4566 Defining_Identifier => Temp_Id,
4567 Object_Definition => New_Reference_To (Ptr_Id, Loc));
4569 Insert_Action (Ins_Node, Temp_Decl);
4570 Analyze (Temp_Decl);
4572 -- Mark this temporary as created for the purposes of exporting the
4573 -- transient declaration out of the Actions list. This signals the
4574 -- machinery in Build_Finalizer to recognize this special case.
4576 Set_Return_Flag_Or_Transient_Decl (Temp_Id, Decl);
4578 -- Step 3: Hook the transient object to the temporary
4580 if Is_Access_Type (Obj_Typ) then
4581 Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc));
4584 Make_Attribute_Reference (Loc,
4585 Prefix => New_Reference_To (Obj_Id, Loc),
4586 Attribute_Name => Name_Unrestricted_Access);
4590 -- Temp := Ptr_Id (Obj_Id);
4592 -- Temp := Obj_Id'Unrestricted_Access;
4594 Insert_After_And_Analyze (Decl,
4595 Make_Assignment_Statement (Loc,
4596 Name => New_Reference_To (Temp_Id, Loc),
4597 Expression => Expr));
4598 end Process_Transient_Object;
4604 -- Start of processing for Expand_N_Expression_With_Actions
4607 Decl := First (Actions (N));
4608 while Present (Decl) loop
4609 if Nkind (Decl) = N_Object_Declaration
4610 and then Is_Finalizable_Transient (Decl, N)
4612 Process_Transient_Object (Decl);
4617 end Expand_N_Expression_With_Actions;
4623 procedure Expand_N_In (N : Node_Id) is
4624 Loc : constant Source_Ptr := Sloc (N);
4625 Restyp : constant Entity_Id := Etype (N);
4626 Lop : constant Node_Id := Left_Opnd (N);
4627 Rop : constant Node_Id := Right_Opnd (N);
4628 Static : constant Boolean := Is_OK_Static_Expression (N);
4633 procedure Expand_Set_Membership;
4634 -- For each choice we create a simple equality or membership test.
4635 -- The whole membership is rewritten connecting these with OR ELSE.
4637 ---------------------------
4638 -- Expand_Set_Membership --
4639 ---------------------------
4641 procedure Expand_Set_Membership is
4645 function Make_Cond (Alt : Node_Id) return Node_Id;
4646 -- If the alternative is a subtype mark, create a simple membership
4647 -- test. Otherwise create an equality test for it.
4653 function Make_Cond (Alt : Node_Id) return Node_Id is
4655 L : constant Node_Id := New_Copy (Lop);
4656 R : constant Node_Id := Relocate_Node (Alt);
4659 if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
4660 or else Nkind (Alt) = N_Range
4663 Make_In (Sloc (Alt),
4668 Make_Op_Eq (Sloc (Alt),
4676 -- Start of processing for Expand_Set_Membership
4679 Alt := Last (Alternatives (N));
4680 Res := Make_Cond (Alt);
4683 while Present (Alt) loop
4685 Make_Or_Else (Sloc (Alt),
4686 Left_Opnd => Make_Cond (Alt),
4692 Analyze_And_Resolve (N, Standard_Boolean);
4693 end Expand_Set_Membership;
4695 procedure Substitute_Valid_Check;
4696 -- Replaces node N by Lop'Valid. This is done when we have an explicit
4697 -- test for the left operand being in range of its subtype.
4699 ----------------------------
4700 -- Substitute_Valid_Check --
4701 ----------------------------
4703 procedure Substitute_Valid_Check is
4706 Make_Attribute_Reference (Loc,
4707 Prefix => Relocate_Node (Lop),
4708 Attribute_Name => Name_Valid));
4710 Analyze_And_Resolve (N, Restyp);
4712 Error_Msg_N ("?explicit membership test may be optimized away", N);
4713 Error_Msg_N -- CODEFIX
4714 ("\?use ''Valid attribute instead", N);
4716 end Substitute_Valid_Check;
4718 -- Start of processing for Expand_N_In
4721 -- If set membership case, expand with separate procedure
4723 if Present (Alternatives (N)) then
4724 Remove_Side_Effects (Lop);
4725 Expand_Set_Membership;
4729 -- Not set membership, proceed with expansion
4731 Ltyp := Etype (Left_Opnd (N));
4732 Rtyp := Etype (Right_Opnd (N));
4734 -- Check case of explicit test for an expression in range of its
4735 -- subtype. This is suspicious usage and we replace it with a 'Valid
4736 -- test and give a warning. For floating point types however, this is a
4737 -- standard way to check for finite numbers, and using 'Valid would
4738 -- typically be a pessimization. Also skip this test for predicated
4739 -- types, since it is perfectly reasonable to check if a value meets
4742 if Is_Scalar_Type (Ltyp)
4743 and then not Is_Floating_Point_Type (Ltyp)
4744 and then Nkind (Rop) in N_Has_Entity
4745 and then Ltyp = Entity (Rop)
4746 and then Comes_From_Source (N)
4747 and then VM_Target = No_VM
4748 and then not (Is_Discrete_Type (Ltyp)
4749 and then Present (Predicate_Function (Ltyp)))
4751 Substitute_Valid_Check;
4755 -- Do validity check on operands
4757 if Validity_Checks_On and Validity_Check_Operands then
4758 Ensure_Valid (Left_Opnd (N));
4759 Validity_Check_Range (Right_Opnd (N));
4762 -- Case of explicit range
4764 if Nkind (Rop) = N_Range then
4766 Lo : constant Node_Id := Low_Bound (Rop);
4767 Hi : constant Node_Id := High_Bound (Rop);
4769 Lo_Orig : constant Node_Id := Original_Node (Lo);
4770 Hi_Orig : constant Node_Id := Original_Node (Hi);
4772 Lcheck : Compare_Result;
4773 Ucheck : Compare_Result;
4775 Warn1 : constant Boolean :=
4776 Constant_Condition_Warnings
4777 and then Comes_From_Source (N)
4778 and then not In_Instance;
4779 -- This must be true for any of the optimization warnings, we
4780 -- clearly want to give them only for source with the flag on. We
4781 -- also skip these warnings in an instance since it may be the
4782 -- case that different instantiations have different ranges.
4784 Warn2 : constant Boolean :=
4786 and then Nkind (Original_Node (Rop)) = N_Range
4787 and then Is_Integer_Type (Etype (Lo));
4788 -- For the case where only one bound warning is elided, we also
4789 -- insist on an explicit range and an integer type. The reason is
4790 -- that the use of enumeration ranges including an end point is
4791 -- common, as is the use of a subtype name, one of whose bounds is
4792 -- the same as the type of the expression.
4795 -- If test is explicit x'First .. x'Last, replace by valid check
4797 -- Could use some individual comments for this complex test ???
4799 if Is_Scalar_Type (Ltyp)
4800 and then Nkind (Lo_Orig) = N_Attribute_Reference
4801 and then Attribute_Name (Lo_Orig) = Name_First
4802 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
4803 and then Entity (Prefix (Lo_Orig)) = Ltyp
4804 and then Nkind (Hi_Orig) = N_Attribute_Reference
4805 and then Attribute_Name (Hi_Orig) = Name_Last
4806 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
4807 and then Entity (Prefix (Hi_Orig)) = Ltyp
4808 and then Comes_From_Source (N)
4809 and then VM_Target = No_VM
4811 Substitute_Valid_Check;
4815 -- If bounds of type are known at compile time, and the end points
4816 -- are known at compile time and identical, this is another case
4817 -- for substituting a valid test. We only do this for discrete
4818 -- types, since it won't arise in practice for float types.
4820 if Comes_From_Source (N)
4821 and then Is_Discrete_Type (Ltyp)
4822 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
4823 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
4824 and then Compile_Time_Known_Value (Lo)
4825 and then Compile_Time_Known_Value (Hi)
4826 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
4827 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
4829 -- Kill warnings in instances, since they may be cases where we
4830 -- have a test in the generic that makes sense with some types
4831 -- and not with other types.
4833 and then not In_Instance
4835 Substitute_Valid_Check;
4839 -- If we have an explicit range, do a bit of optimization based on
4840 -- range analysis (we may be able to kill one or both checks).
4842 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
4843 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
4845 -- If either check is known to fail, replace result by False since
4846 -- the other check does not matter. Preserve the static flag for
4847 -- legality checks, because we are constant-folding beyond RM 4.9.
4849 if Lcheck = LT or else Ucheck = GT then
4851 Error_Msg_N ("?range test optimized away", N);
4852 Error_Msg_N ("\?value is known to be out of range", N);
4855 Rewrite (N, New_Reference_To (Standard_False, Loc));
4856 Analyze_And_Resolve (N, Restyp);
4857 Set_Is_Static_Expression (N, Static);
4860 -- If both checks are known to succeed, replace result by True,
4861 -- since we know we are in range.
4863 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4865 Error_Msg_N ("?range test optimized away", N);
4866 Error_Msg_N ("\?value is known to be in range", N);
4869 Rewrite (N, New_Reference_To (Standard_True, Loc));
4870 Analyze_And_Resolve (N, Restyp);
4871 Set_Is_Static_Expression (N, Static);
4874 -- If lower bound check succeeds and upper bound check is not
4875 -- known to succeed or fail, then replace the range check with
4876 -- a comparison against the upper bound.
4878 elsif Lcheck in Compare_GE then
4879 if Warn2 and then not In_Instance then
4880 Error_Msg_N ("?lower bound test optimized away", Lo);
4881 Error_Msg_N ("\?value is known to be in range", Lo);
4887 Right_Opnd => High_Bound (Rop)));
4888 Analyze_And_Resolve (N, Restyp);
4891 -- If upper bound check succeeds and lower bound check is not
4892 -- known to succeed or fail, then replace the range check with
4893 -- a comparison against the lower bound.
4895 elsif Ucheck in Compare_LE then
4896 if Warn2 and then not In_Instance then
4897 Error_Msg_N ("?upper bound test optimized away", Hi);
4898 Error_Msg_N ("\?value is known to be in range", Hi);
4904 Right_Opnd => Low_Bound (Rop)));
4905 Analyze_And_Resolve (N, Restyp);
4909 -- We couldn't optimize away the range check, but there is one
4910 -- more issue. If we are checking constant conditionals, then we
4911 -- see if we can determine the outcome assuming everything is
4912 -- valid, and if so give an appropriate warning.
4914 if Warn1 and then not Assume_No_Invalid_Values then
4915 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4916 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4918 -- Result is out of range for valid value
4920 if Lcheck = LT or else Ucheck = GT then
4922 ("?value can only be in range if it is invalid", N);
4924 -- Result is in range for valid value
4926 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4928 ("?value can only be out of range if it is invalid", N);
4930 -- Lower bound check succeeds if value is valid
4932 elsif Warn2 and then Lcheck in Compare_GE then
4934 ("?lower bound check only fails if it is invalid", Lo);
4936 -- Upper bound check succeeds if value is valid
4938 elsif Warn2 and then Ucheck in Compare_LE then
4940 ("?upper bound check only fails for invalid values", Hi);
4945 -- For all other cases of an explicit range, nothing to be done
4949 -- Here right operand is a subtype mark
4953 Typ : Entity_Id := Etype (Rop);
4954 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4955 Cond : Node_Id := Empty;
4957 Obj : Node_Id := Lop;
4958 SCIL_Node : Node_Id;
4961 Remove_Side_Effects (Obj);
4963 -- For tagged type, do tagged membership operation
4965 if Is_Tagged_Type (Typ) then
4967 -- No expansion will be performed when VM_Target, as the VM
4968 -- back-ends will handle the membership tests directly (tags
4969 -- are not explicitly represented in Java objects, so the
4970 -- normal tagged membership expansion is not what we want).
4972 if Tagged_Type_Expansion then
4973 Tagged_Membership (N, SCIL_Node, New_N);
4975 Analyze_And_Resolve (N, Restyp);
4977 -- Update decoration of relocated node referenced by the
4980 if Generate_SCIL and then Present (SCIL_Node) then
4981 Set_SCIL_Node (N, SCIL_Node);
4987 -- If type is scalar type, rewrite as x in t'First .. t'Last.
4988 -- This reason we do this is that the bounds may have the wrong
4989 -- type if they come from the original type definition. Also this
4990 -- way we get all the processing above for an explicit range.
4992 -- Don't do this for predicated types, since in this case we
4993 -- want to check the predicate!
4995 elsif Is_Scalar_Type (Typ) then
4996 if No (Predicate_Function (Typ)) then
5000 Make_Attribute_Reference (Loc,
5001 Attribute_Name => Name_First,
5002 Prefix => New_Reference_To (Typ, Loc)),
5005 Make_Attribute_Reference (Loc,
5006 Attribute_Name => Name_Last,
5007 Prefix => New_Reference_To (Typ, Loc))));
5008 Analyze_And_Resolve (N, Restyp);
5013 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
5014 -- a membership test if the subtype mark denotes a constrained
5015 -- Unchecked_Union subtype and the expression lacks inferable
5018 elsif Is_Unchecked_Union (Base_Type (Typ))
5019 and then Is_Constrained (Typ)
5020 and then not Has_Inferable_Discriminants (Lop)
5023 Make_Raise_Program_Error (Loc,
5024 Reason => PE_Unchecked_Union_Restriction));
5026 -- Prevent Gigi from generating incorrect code by rewriting the
5029 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5033 -- Here we have a non-scalar type
5036 Typ := Designated_Type (Typ);
5039 if not Is_Constrained (Typ) then
5040 Rewrite (N, New_Reference_To (Standard_True, Loc));
5041 Analyze_And_Resolve (N, Restyp);
5043 -- For the constrained array case, we have to check the subscripts
5044 -- for an exact match if the lengths are non-zero (the lengths
5045 -- must match in any case).
5047 elsif Is_Array_Type (Typ) then
5048 Check_Subscripts : declare
5049 function Build_Attribute_Reference
5052 Dim : Nat) return Node_Id;
5053 -- Build attribute reference E'Nam (Dim)
5055 -------------------------------
5056 -- Build_Attribute_Reference --
5057 -------------------------------
5059 function Build_Attribute_Reference
5062 Dim : Nat) return Node_Id
5066 Make_Attribute_Reference (Loc,
5068 Attribute_Name => Nam,
5069 Expressions => New_List (
5070 Make_Integer_Literal (Loc, Dim)));
5071 end Build_Attribute_Reference;
5073 -- Start of processing for Check_Subscripts
5076 for J in 1 .. Number_Dimensions (Typ) loop
5077 Evolve_And_Then (Cond,
5080 Build_Attribute_Reference
5081 (Duplicate_Subexpr_No_Checks (Obj),
5084 Build_Attribute_Reference
5085 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
5087 Evolve_And_Then (Cond,
5090 Build_Attribute_Reference
5091 (Duplicate_Subexpr_No_Checks (Obj),
5094 Build_Attribute_Reference
5095 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
5104 Right_Opnd => Make_Null (Loc)),
5105 Right_Opnd => Cond);
5109 Analyze_And_Resolve (N, Restyp);
5110 end Check_Subscripts;
5112 -- These are the cases where constraint checks may be required,
5113 -- e.g. records with possible discriminants
5116 -- Expand the test into a series of discriminant comparisons.
5117 -- The expression that is built is the negation of the one that
5118 -- is used for checking discriminant constraints.
5120 Obj := Relocate_Node (Left_Opnd (N));
5122 if Has_Discriminants (Typ) then
5123 Cond := Make_Op_Not (Loc,
5124 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
5127 Cond := Make_Or_Else (Loc,
5131 Right_Opnd => Make_Null (Loc)),
5132 Right_Opnd => Cond);
5136 Cond := New_Occurrence_Of (Standard_True, Loc);
5140 Analyze_And_Resolve (N, Restyp);
5143 -- Ada 2012 (AI05-0149): Handle membership tests applied to an
5144 -- expression of an anonymous access type. This can involve an
5145 -- accessibility test and a tagged type membership test in the
5146 -- case of tagged designated types.
5148 if Ada_Version >= Ada_2012
5150 and then Ekind (Ltyp) = E_Anonymous_Access_Type
5153 Expr_Entity : Entity_Id := Empty;
5155 Param_Level : Node_Id;
5156 Type_Level : Node_Id;
5159 if Is_Entity_Name (Lop) then
5160 Expr_Entity := Param_Entity (Lop);
5162 if not Present (Expr_Entity) then
5163 Expr_Entity := Entity (Lop);
5167 -- If a conversion of the anonymous access value to the
5168 -- tested type would be illegal, then the result is False.
5170 if not Valid_Conversion
5171 (Lop, Rtyp, Lop, Report_Errs => False)
5173 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5174 Analyze_And_Resolve (N, Restyp);
5176 -- Apply an accessibility check if the access object has an
5177 -- associated access level and when the level of the type is
5178 -- less deep than the level of the access parameter. This
5179 -- only occur for access parameters and stand-alone objects
5180 -- of an anonymous access type.
5183 if Present (Expr_Entity)
5186 (Effective_Extra_Accessibility (Expr_Entity))
5187 and then UI_Gt (Object_Access_Level (Lop),
5188 Type_Access_Level (Rtyp))
5192 (Effective_Extra_Accessibility (Expr_Entity), Loc);
5195 Make_Integer_Literal (Loc, Type_Access_Level (Rtyp));
5197 -- Return True only if the accessibility level of the
5198 -- expression entity is not deeper than the level of
5199 -- the tested access type.
5203 Left_Opnd => Relocate_Node (N),
5204 Right_Opnd => Make_Op_Le (Loc,
5205 Left_Opnd => Param_Level,
5206 Right_Opnd => Type_Level)));
5208 Analyze_And_Resolve (N);
5211 -- If the designated type is tagged, do tagged membership
5214 -- *** NOTE: we have to check not null before doing the
5215 -- tagged membership test (but maybe that can be done
5216 -- inside Tagged_Membership?).
5218 if Is_Tagged_Type (Typ) then
5221 Left_Opnd => Relocate_Node (N),
5225 Right_Opnd => Make_Null (Loc))));
5227 -- No expansion will be performed when VM_Target, as
5228 -- the VM back-ends will handle the membership tests
5229 -- directly (tags are not explicitly represented in
5230 -- Java objects, so the normal tagged membership
5231 -- expansion is not what we want).
5233 if Tagged_Type_Expansion then
5235 -- Note that we have to pass Original_Node, because
5236 -- the membership test might already have been
5237 -- rewritten by earlier parts of membership test.
5240 (Original_Node (N), SCIL_Node, New_N);
5242 -- Update decoration of relocated node referenced
5243 -- by the SCIL node.
5245 if Generate_SCIL and then Present (SCIL_Node) then
5246 Set_SCIL_Node (New_N, SCIL_Node);
5251 Left_Opnd => Relocate_Node (N),
5252 Right_Opnd => New_N));
5254 Analyze_And_Resolve (N, Restyp);
5263 -- At this point, we have done the processing required for the basic
5264 -- membership test, but not yet dealt with the predicate.
5268 -- If a predicate is present, then we do the predicate test, but we
5269 -- most certainly want to omit this if we are within the predicate
5270 -- function itself, since otherwise we have an infinite recursion!
5273 PFunc : constant Entity_Id := Predicate_Function (Rtyp);
5277 and then Current_Scope /= PFunc
5281 Left_Opnd => Relocate_Node (N),
5282 Right_Opnd => Make_Predicate_Call (Rtyp, Lop)));
5284 -- Analyze new expression, mark left operand as analyzed to
5285 -- avoid infinite recursion adding predicate calls.
5287 Set_Analyzed (Left_Opnd (N));
5288 Analyze_And_Resolve (N, Standard_Boolean);
5290 -- All done, skip attempt at compile time determination of result
5297 --------------------------------
5298 -- Expand_N_Indexed_Component --
5299 --------------------------------
5301 procedure Expand_N_Indexed_Component (N : Node_Id) is
5302 Loc : constant Source_Ptr := Sloc (N);
5303 Typ : constant Entity_Id := Etype (N);
5304 P : constant Node_Id := Prefix (N);
5305 T : constant Entity_Id := Etype (P);
5308 -- A special optimization, if we have an indexed component that is
5309 -- selecting from a slice, then we can eliminate the slice, since, for
5310 -- example, x (i .. j)(k) is identical to x(k). The only difference is
5311 -- the range check required by the slice. The range check for the slice
5312 -- itself has already been generated. The range check for the
5313 -- subscripting operation is ensured by converting the subject to
5314 -- the subtype of the slice.
5316 -- This optimization not only generates better code, avoiding slice
5317 -- messing especially in the packed case, but more importantly bypasses
5318 -- some problems in handling this peculiar case, for example, the issue
5319 -- of dealing specially with object renamings.
5321 if Nkind (P) = N_Slice then
5323 Make_Indexed_Component (Loc,
5324 Prefix => Prefix (P),
5325 Expressions => New_List (
5327 (Etype (First_Index (Etype (P))),
5328 First (Expressions (N))))));
5329 Analyze_And_Resolve (N, Typ);
5333 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
5334 -- function, then additional actuals must be passed.
5336 if Ada_Version >= Ada_2005
5337 and then Is_Build_In_Place_Function_Call (P)
5339 Make_Build_In_Place_Call_In_Anonymous_Context (P);
5342 -- If the prefix is an access type, then we unconditionally rewrite if
5343 -- as an explicit dereference. This simplifies processing for several
5344 -- cases, including packed array cases and certain cases in which checks
5345 -- must be generated. We used to try to do this only when it was
5346 -- necessary, but it cleans up the code to do it all the time.
5348 if Is_Access_Type (T) then
5349 Insert_Explicit_Dereference (P);
5350 Analyze_And_Resolve (P, Designated_Type (T));
5353 -- Generate index and validity checks
5355 Generate_Index_Checks (N);
5357 if Validity_Checks_On and then Validity_Check_Subscripts then
5358 Apply_Subscript_Validity_Checks (N);
5361 -- All done for the non-packed case
5363 if not Is_Packed (Etype (Prefix (N))) then
5367 -- For packed arrays that are not bit-packed (i.e. the case of an array
5368 -- with one or more index types with a non-contiguous enumeration type),
5369 -- we can always use the normal packed element get circuit.
5371 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
5372 Expand_Packed_Element_Reference (N);
5376 -- For a reference to a component of a bit packed array, we have to
5377 -- convert it to a reference to the corresponding Packed_Array_Type.
5378 -- We only want to do this for simple references, and not for:
5380 -- Left side of assignment, or prefix of left side of assignment, or
5381 -- prefix of the prefix, to handle packed arrays of packed arrays,
5382 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
5384 -- Renaming objects in renaming associations
5385 -- This case is handled when a use of the renamed variable occurs
5387 -- Actual parameters for a procedure call
5388 -- This case is handled in Exp_Ch6.Expand_Actuals
5390 -- The second expression in a 'Read attribute reference
5392 -- The prefix of an address or bit or size attribute reference
5394 -- The following circuit detects these exceptions
5397 Child : Node_Id := N;
5398 Parnt : Node_Id := Parent (N);
5402 if Nkind (Parnt) = N_Unchecked_Expression then
5405 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
5406 N_Procedure_Call_Statement)
5407 or else (Nkind (Parnt) = N_Parameter_Association
5409 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
5413 elsif Nkind (Parnt) = N_Attribute_Reference
5414 and then (Attribute_Name (Parnt) = Name_Address
5416 Attribute_Name (Parnt) = Name_Bit
5418 Attribute_Name (Parnt) = Name_Size)
5419 and then Prefix (Parnt) = Child
5423 elsif Nkind (Parnt) = N_Assignment_Statement
5424 and then Name (Parnt) = Child
5428 -- If the expression is an index of an indexed component, it must
5429 -- be expanded regardless of context.
5431 elsif Nkind (Parnt) = N_Indexed_Component
5432 and then Child /= Prefix (Parnt)
5434 Expand_Packed_Element_Reference (N);
5437 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
5438 and then Name (Parent (Parnt)) = Parnt
5442 elsif Nkind (Parnt) = N_Attribute_Reference
5443 and then Attribute_Name (Parnt) = Name_Read
5444 and then Next (First (Expressions (Parnt))) = Child
5448 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
5449 and then Prefix (Parnt) = Child
5454 Expand_Packed_Element_Reference (N);
5458 -- Keep looking up tree for unchecked expression, or if we are the
5459 -- prefix of a possible assignment left side.
5462 Parnt := Parent (Child);
5465 end Expand_N_Indexed_Component;
5467 ---------------------
5468 -- Expand_N_Not_In --
5469 ---------------------
5471 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
5472 -- can be done. This avoids needing to duplicate this expansion code.
5474 procedure Expand_N_Not_In (N : Node_Id) is
5475 Loc : constant Source_Ptr := Sloc (N);
5476 Typ : constant Entity_Id := Etype (N);
5477 Cfs : constant Boolean := Comes_From_Source (N);
5484 Left_Opnd => Left_Opnd (N),
5485 Right_Opnd => Right_Opnd (N))));
5487 -- If this is a set membership, preserve list of alternatives
5489 Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
5491 -- We want this to appear as coming from source if original does (see
5492 -- transformations in Expand_N_In).
5494 Set_Comes_From_Source (N, Cfs);
5495 Set_Comes_From_Source (Right_Opnd (N), Cfs);
5497 -- Now analyze transformed node
5499 Analyze_And_Resolve (N, Typ);
5500 end Expand_N_Not_In;
5506 -- The only replacement required is for the case of a null of a type that
5507 -- is an access to protected subprogram, or a subtype thereof. We represent
5508 -- such access values as a record, and so we must replace the occurrence of
5509 -- null by the equivalent record (with a null address and a null pointer in
5510 -- it), so that the backend creates the proper value.
5512 procedure Expand_N_Null (N : Node_Id) is
5513 Loc : constant Source_Ptr := Sloc (N);
5514 Typ : constant Entity_Id := Base_Type (Etype (N));
5518 if Is_Access_Protected_Subprogram_Type (Typ) then
5520 Make_Aggregate (Loc,
5521 Expressions => New_List (
5522 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
5526 Analyze_And_Resolve (N, Equivalent_Type (Typ));
5528 -- For subsequent semantic analysis, the node must retain its type.
5529 -- Gigi in any case replaces this type by the corresponding record
5530 -- type before processing the node.
5536 when RE_Not_Available =>
5540 ---------------------
5541 -- Expand_N_Op_Abs --
5542 ---------------------
5544 procedure Expand_N_Op_Abs (N : Node_Id) is
5545 Loc : constant Source_Ptr := Sloc (N);
5546 Expr : constant Node_Id := Right_Opnd (N);
5549 Unary_Op_Validity_Checks (N);
5551 -- Deal with software overflow checking
5553 if not Backend_Overflow_Checks_On_Target
5554 and then Is_Signed_Integer_Type (Etype (N))
5555 and then Do_Overflow_Check (N)
5557 -- The only case to worry about is when the argument is equal to the
5558 -- largest negative number, so what we do is to insert the check:
5560 -- [constraint_error when Expr = typ'Base'First]
5562 -- with the usual Duplicate_Subexpr use coding for expr
5565 Make_Raise_Constraint_Error (Loc,
5568 Left_Opnd => Duplicate_Subexpr (Expr),
5570 Make_Attribute_Reference (Loc,
5572 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
5573 Attribute_Name => Name_First)),
5574 Reason => CE_Overflow_Check_Failed));
5577 -- Vax floating-point types case
5579 if Vax_Float (Etype (N)) then
5580 Expand_Vax_Arith (N);
5582 end Expand_N_Op_Abs;
5584 ---------------------
5585 -- Expand_N_Op_Add --
5586 ---------------------
5588 procedure Expand_N_Op_Add (N : Node_Id) is
5589 Typ : constant Entity_Id := Etype (N);
5592 Binary_Op_Validity_Checks (N);
5594 -- N + 0 = 0 + N = N for integer types
5596 if Is_Integer_Type (Typ) then
5597 if Compile_Time_Known_Value (Right_Opnd (N))
5598 and then Expr_Value (Right_Opnd (N)) = Uint_0
5600 Rewrite (N, Left_Opnd (N));
5603 elsif Compile_Time_Known_Value (Left_Opnd (N))
5604 and then Expr_Value (Left_Opnd (N)) = Uint_0
5606 Rewrite (N, Right_Opnd (N));
5611 -- Arithmetic overflow checks for signed integer/fixed point types
5613 if Is_Signed_Integer_Type (Typ)
5614 or else Is_Fixed_Point_Type (Typ)
5616 Apply_Arithmetic_Overflow_Check (N);
5619 -- Vax floating-point types case
5621 elsif Vax_Float (Typ) then
5622 Expand_Vax_Arith (N);
5624 end Expand_N_Op_Add;
5626 ---------------------
5627 -- Expand_N_Op_And --
5628 ---------------------
5630 procedure Expand_N_Op_And (N : Node_Id) is
5631 Typ : constant Entity_Id := Etype (N);
5634 Binary_Op_Validity_Checks (N);
5636 if Is_Array_Type (Etype (N)) then
5637 Expand_Boolean_Operator (N);
5639 elsif Is_Boolean_Type (Etype (N)) then
5641 -- Replace AND by AND THEN if Short_Circuit_And_Or active and the
5642 -- type is standard Boolean (do not mess with AND that uses a non-
5643 -- standard Boolean type, because something strange is going on).
5645 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
5647 Make_And_Then (Sloc (N),
5648 Left_Opnd => Relocate_Node (Left_Opnd (N)),
5649 Right_Opnd => Relocate_Node (Right_Opnd (N))));
5650 Analyze_And_Resolve (N, Typ);
5652 -- Otherwise, adjust conditions
5655 Adjust_Condition (Left_Opnd (N));
5656 Adjust_Condition (Right_Opnd (N));
5657 Set_Etype (N, Standard_Boolean);
5658 Adjust_Result_Type (N, Typ);
5661 elsif Is_Intrinsic_Subprogram (Entity (N)) then
5662 Expand_Intrinsic_Call (N, Entity (N));
5665 end Expand_N_Op_And;
5667 ------------------------
5668 -- Expand_N_Op_Concat --
5669 ------------------------
5671 procedure Expand_N_Op_Concat (N : Node_Id) is
5673 -- List of operands to be concatenated
5676 -- Node which is to be replaced by the result of concatenating the nodes
5677 -- in the list Opnds.
5680 -- Ensure validity of both operands
5682 Binary_Op_Validity_Checks (N);
5684 -- If we are the left operand of a concatenation higher up the tree,
5685 -- then do nothing for now, since we want to deal with a series of
5686 -- concatenations as a unit.
5688 if Nkind (Parent (N)) = N_Op_Concat
5689 and then N = Left_Opnd (Parent (N))
5694 -- We get here with a concatenation whose left operand may be a
5695 -- concatenation itself with a consistent type. We need to process
5696 -- these concatenation operands from left to right, which means
5697 -- from the deepest node in the tree to the highest node.
5700 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
5701 Cnode := Left_Opnd (Cnode);
5704 -- Now Cnode is the deepest concatenation, and its parents are the
5705 -- concatenation nodes above, so now we process bottom up, doing the
5706 -- operations. We gather a string that is as long as possible up to five
5709 -- The outer loop runs more than once if more than one concatenation
5710 -- type is involved.
5713 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
5714 Set_Parent (Opnds, N);
5716 -- The inner loop gathers concatenation operands
5718 Inner : while Cnode /= N
5719 and then Base_Type (Etype (Cnode)) =
5720 Base_Type (Etype (Parent (Cnode)))
5722 Cnode := Parent (Cnode);
5723 Append (Right_Opnd (Cnode), Opnds);
5726 Expand_Concatenate (Cnode, Opnds);
5728 exit Outer when Cnode = N;
5729 Cnode := Parent (Cnode);
5731 end Expand_N_Op_Concat;
5733 ------------------------
5734 -- Expand_N_Op_Divide --
5735 ------------------------
5737 procedure Expand_N_Op_Divide (N : Node_Id) is
5738 Loc : constant Source_Ptr := Sloc (N);
5739 Lopnd : constant Node_Id := Left_Opnd (N);
5740 Ropnd : constant Node_Id := Right_Opnd (N);
5741 Ltyp : constant Entity_Id := Etype (Lopnd);
5742 Rtyp : constant Entity_Id := Etype (Ropnd);
5743 Typ : Entity_Id := Etype (N);
5744 Rknow : constant Boolean := Is_Integer_Type (Typ)
5746 Compile_Time_Known_Value (Ropnd);
5750 Binary_Op_Validity_Checks (N);
5753 Rval := Expr_Value (Ropnd);
5756 -- N / 1 = N for integer types
5758 if Rknow and then Rval = Uint_1 then
5763 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
5764 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5765 -- operand is an unsigned integer, as required for this to work.
5767 if Nkind (Ropnd) = N_Op_Expon
5768 and then Is_Power_Of_2_For_Shift (Ropnd)
5770 -- We cannot do this transformation in configurable run time mode if we
5771 -- have 64-bit integers and long shifts are not available.
5775 or else Support_Long_Shifts_On_Target)
5778 Make_Op_Shift_Right (Loc,
5781 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
5782 Analyze_And_Resolve (N, Typ);
5786 -- Do required fixup of universal fixed operation
5788 if Typ = Universal_Fixed then
5789 Fixup_Universal_Fixed_Operation (N);
5793 -- Divisions with fixed-point results
5795 if Is_Fixed_Point_Type (Typ) then
5797 -- No special processing if Treat_Fixed_As_Integer is set, since
5798 -- from a semantic point of view such operations are simply integer
5799 -- operations and will be treated that way.
5801 if not Treat_Fixed_As_Integer (N) then
5802 if Is_Integer_Type (Rtyp) then
5803 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
5805 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
5809 -- Other cases of division of fixed-point operands. Again we exclude the
5810 -- case where Treat_Fixed_As_Integer is set.
5812 elsif (Is_Fixed_Point_Type (Ltyp) or else
5813 Is_Fixed_Point_Type (Rtyp))
5814 and then not Treat_Fixed_As_Integer (N)
5816 if Is_Integer_Type (Typ) then
5817 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
5819 pragma Assert (Is_Floating_Point_Type (Typ));
5820 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
5823 -- Mixed-mode operations can appear in a non-static universal context,
5824 -- in which case the integer argument must be converted explicitly.
5826 elsif Typ = Universal_Real
5827 and then Is_Integer_Type (Rtyp)
5830 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
5832 Analyze_And_Resolve (Ropnd, Universal_Real);
5834 elsif Typ = Universal_Real
5835 and then Is_Integer_Type (Ltyp)
5838 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
5840 Analyze_And_Resolve (Lopnd, Universal_Real);
5842 -- Non-fixed point cases, do integer zero divide and overflow checks
5844 elsif Is_Integer_Type (Typ) then
5845 Apply_Divide_Check (N);
5847 -- Deal with Vax_Float
5849 elsif Vax_Float (Typ) then
5850 Expand_Vax_Arith (N);
5853 end Expand_N_Op_Divide;
5855 --------------------
5856 -- Expand_N_Op_Eq --
5857 --------------------
5859 procedure Expand_N_Op_Eq (N : Node_Id) is
5860 Loc : constant Source_Ptr := Sloc (N);
5861 Typ : constant Entity_Id := Etype (N);
5862 Lhs : constant Node_Id := Left_Opnd (N);
5863 Rhs : constant Node_Id := Right_Opnd (N);
5864 Bodies : constant List_Id := New_List;
5865 A_Typ : constant Entity_Id := Etype (Lhs);
5867 Typl : Entity_Id := A_Typ;
5868 Op_Name : Entity_Id;
5871 procedure Build_Equality_Call (Eq : Entity_Id);
5872 -- If a constructed equality exists for the type or for its parent,
5873 -- build and analyze call, adding conversions if the operation is
5876 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
5877 -- Determines whether a type has a subcomponent of an unconstrained
5878 -- Unchecked_Union subtype. Typ is a record type.
5880 -------------------------
5881 -- Build_Equality_Call --
5882 -------------------------
5884 procedure Build_Equality_Call (Eq : Entity_Id) is
5885 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
5886 L_Exp : Node_Id := Relocate_Node (Lhs);
5887 R_Exp : Node_Id := Relocate_Node (Rhs);
5890 if Base_Type (Op_Type) /= Base_Type (A_Typ)
5891 and then not Is_Class_Wide_Type (A_Typ)
5893 L_Exp := OK_Convert_To (Op_Type, L_Exp);
5894 R_Exp := OK_Convert_To (Op_Type, R_Exp);
5897 -- If we have an Unchecked_Union, we need to add the inferred
5898 -- discriminant values as actuals in the function call. At this
5899 -- point, the expansion has determined that both operands have
5900 -- inferable discriminants.
5902 if Is_Unchecked_Union (Op_Type) then
5904 Lhs_Type : constant Node_Id := Etype (L_Exp);
5905 Rhs_Type : constant Node_Id := Etype (R_Exp);
5906 Lhs_Discr_Val : Node_Id;
5907 Rhs_Discr_Val : Node_Id;
5910 -- Per-object constrained selected components require special
5911 -- attention. If the enclosing scope of the component is an
5912 -- Unchecked_Union, we cannot reference its discriminants
5913 -- directly. This is why we use the two extra parameters of
5914 -- the equality function of the enclosing Unchecked_Union.
5916 -- type UU_Type (Discr : Integer := 0) is
5919 -- pragma Unchecked_Union (UU_Type);
5921 -- 1. Unchecked_Union enclosing record:
5923 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
5925 -- Comp : UU_Type (Discr);
5927 -- end Enclosing_UU_Type;
5928 -- pragma Unchecked_Union (Enclosing_UU_Type);
5930 -- Obj1 : Enclosing_UU_Type;
5931 -- Obj2 : Enclosing_UU_Type (1);
5933 -- [. . .] Obj1 = Obj2 [. . .]
5937 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
5939 -- A and B are the formal parameters of the equality function
5940 -- of Enclosing_UU_Type. The function always has two extra
5941 -- formals to capture the inferred discriminant values.
5943 -- 2. Non-Unchecked_Union enclosing record:
5946 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
5949 -- Comp : UU_Type (Discr);
5951 -- end Enclosing_Non_UU_Type;
5953 -- Obj1 : Enclosing_Non_UU_Type;
5954 -- Obj2 : Enclosing_Non_UU_Type (1);
5956 -- ... Obj1 = Obj2 ...
5960 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
5961 -- obj1.discr, obj2.discr)) then
5963 -- In this case we can directly reference the discriminants of
5964 -- the enclosing record.
5968 if Nkind (Lhs) = N_Selected_Component
5969 and then Has_Per_Object_Constraint
5970 (Entity (Selector_Name (Lhs)))
5972 -- Enclosing record is an Unchecked_Union, use formal A
5974 if Is_Unchecked_Union
5975 (Scope (Entity (Selector_Name (Lhs))))
5977 Lhs_Discr_Val := Make_Identifier (Loc, Name_A);
5979 -- Enclosing record is of a non-Unchecked_Union type, it is
5980 -- possible to reference the discriminant.
5984 Make_Selected_Component (Loc,
5985 Prefix => Prefix (Lhs),
5988 (Get_Discriminant_Value
5989 (First_Discriminant (Lhs_Type),
5991 Stored_Constraint (Lhs_Type))));
5994 -- Comment needed here ???
5997 -- Infer the discriminant value
6001 (Get_Discriminant_Value
6002 (First_Discriminant (Lhs_Type),
6004 Stored_Constraint (Lhs_Type)));
6009 if Nkind (Rhs) = N_Selected_Component
6010 and then Has_Per_Object_Constraint
6011 (Entity (Selector_Name (Rhs)))
6013 if Is_Unchecked_Union
6014 (Scope (Entity (Selector_Name (Rhs))))
6016 Rhs_Discr_Val := Make_Identifier (Loc, Name_B);
6020 Make_Selected_Component (Loc,
6021 Prefix => Prefix (Rhs),
6023 New_Copy (Get_Discriminant_Value (
6024 First_Discriminant (Rhs_Type),
6026 Stored_Constraint (Rhs_Type))));
6031 New_Copy (Get_Discriminant_Value (
6032 First_Discriminant (Rhs_Type),
6034 Stored_Constraint (Rhs_Type)));
6039 Make_Function_Call (Loc,
6040 Name => New_Reference_To (Eq, Loc),
6041 Parameter_Associations => New_List (
6048 -- Normal case, not an unchecked union
6052 Make_Function_Call (Loc,
6053 Name => New_Reference_To (Eq, Loc),
6054 Parameter_Associations => New_List (L_Exp, R_Exp)));
6057 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6058 end Build_Equality_Call;
6060 ------------------------------------
6061 -- Has_Unconstrained_UU_Component --
6062 ------------------------------------
6064 function Has_Unconstrained_UU_Component
6065 (Typ : Node_Id) return Boolean
6067 Tdef : constant Node_Id :=
6068 Type_Definition (Declaration_Node (Base_Type (Typ)));
6072 function Component_Is_Unconstrained_UU
6073 (Comp : Node_Id) return Boolean;
6074 -- Determines whether the subtype of the component is an
6075 -- unconstrained Unchecked_Union.
6077 function Variant_Is_Unconstrained_UU
6078 (Variant : Node_Id) return Boolean;
6079 -- Determines whether a component of the variant has an unconstrained
6080 -- Unchecked_Union subtype.
6082 -----------------------------------
6083 -- Component_Is_Unconstrained_UU --
6084 -----------------------------------
6086 function Component_Is_Unconstrained_UU
6087 (Comp : Node_Id) return Boolean
6090 if Nkind (Comp) /= N_Component_Declaration then
6095 Sindic : constant Node_Id :=
6096 Subtype_Indication (Component_Definition (Comp));
6099 -- Unconstrained nominal type. In the case of a constraint
6100 -- present, the node kind would have been N_Subtype_Indication.
6102 if Nkind (Sindic) = N_Identifier then
6103 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
6108 end Component_Is_Unconstrained_UU;
6110 ---------------------------------
6111 -- Variant_Is_Unconstrained_UU --
6112 ---------------------------------
6114 function Variant_Is_Unconstrained_UU
6115 (Variant : Node_Id) return Boolean
6117 Clist : constant Node_Id := Component_List (Variant);
6120 if Is_Empty_List (Component_Items (Clist)) then
6124 -- We only need to test one component
6127 Comp : Node_Id := First (Component_Items (Clist));
6130 while Present (Comp) loop
6131 if Component_Is_Unconstrained_UU (Comp) then
6139 -- None of the components withing the variant were of
6140 -- unconstrained Unchecked_Union type.
6143 end Variant_Is_Unconstrained_UU;
6145 -- Start of processing for Has_Unconstrained_UU_Component
6148 if Null_Present (Tdef) then
6152 Clist := Component_List (Tdef);
6153 Vpart := Variant_Part (Clist);
6155 -- Inspect available components
6157 if Present (Component_Items (Clist)) then
6159 Comp : Node_Id := First (Component_Items (Clist));
6162 while Present (Comp) loop
6164 -- One component is sufficient
6166 if Component_Is_Unconstrained_UU (Comp) then
6175 -- Inspect available components withing variants
6177 if Present (Vpart) then
6179 Variant : Node_Id := First (Variants (Vpart));
6182 while Present (Variant) loop
6184 -- One component within a variant is sufficient
6186 if Variant_Is_Unconstrained_UU (Variant) then
6195 -- Neither the available components, nor the components inside the
6196 -- variant parts were of an unconstrained Unchecked_Union subtype.
6199 end Has_Unconstrained_UU_Component;
6201 -- Start of processing for Expand_N_Op_Eq
6204 Binary_Op_Validity_Checks (N);
6206 if Ekind (Typl) = E_Private_Type then
6207 Typl := Underlying_Type (Typl);
6208 elsif Ekind (Typl) = E_Private_Subtype then
6209 Typl := Underlying_Type (Base_Type (Typl));
6214 -- It may happen in error situations that the underlying type is not
6215 -- set. The error will be detected later, here we just defend the
6222 Typl := Base_Type (Typl);
6224 -- Boolean types (requiring handling of non-standard case)
6226 if Is_Boolean_Type (Typl) then
6227 Adjust_Condition (Left_Opnd (N));
6228 Adjust_Condition (Right_Opnd (N));
6229 Set_Etype (N, Standard_Boolean);
6230 Adjust_Result_Type (N, Typ);
6234 elsif Is_Array_Type (Typl) then
6236 -- If we are doing full validity checking, and it is possible for the
6237 -- array elements to be invalid then expand out array comparisons to
6238 -- make sure that we check the array elements.
6240 if Validity_Check_Operands
6241 and then not Is_Known_Valid (Component_Type (Typl))
6244 Save_Force_Validity_Checks : constant Boolean :=
6245 Force_Validity_Checks;
6247 Force_Validity_Checks := True;
6249 Expand_Array_Equality
6251 Relocate_Node (Lhs),
6252 Relocate_Node (Rhs),
6255 Insert_Actions (N, Bodies);
6256 Analyze_And_Resolve (N, Standard_Boolean);
6257 Force_Validity_Checks := Save_Force_Validity_Checks;
6260 -- Packed case where both operands are known aligned
6262 elsif Is_Bit_Packed_Array (Typl)
6263 and then not Is_Possibly_Unaligned_Object (Lhs)
6264 and then not Is_Possibly_Unaligned_Object (Rhs)
6266 Expand_Packed_Eq (N);
6268 -- Where the component type is elementary we can use a block bit
6269 -- comparison (if supported on the target) exception in the case
6270 -- of floating-point (negative zero issues require element by
6271 -- element comparison), and atomic types (where we must be sure
6272 -- to load elements independently) and possibly unaligned arrays.
6274 elsif Is_Elementary_Type (Component_Type (Typl))
6275 and then not Is_Floating_Point_Type (Component_Type (Typl))
6276 and then not Is_Atomic (Component_Type (Typl))
6277 and then not Is_Possibly_Unaligned_Object (Lhs)
6278 and then not Is_Possibly_Unaligned_Object (Rhs)
6279 and then Support_Composite_Compare_On_Target
6283 -- For composite and floating-point cases, expand equality loop to
6284 -- make sure of using proper comparisons for tagged types, and
6285 -- correctly handling the floating-point case.
6289 Expand_Array_Equality
6291 Relocate_Node (Lhs),
6292 Relocate_Node (Rhs),
6295 Insert_Actions (N, Bodies, Suppress => All_Checks);
6296 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6301 elsif Is_Record_Type (Typl) then
6303 -- For tagged types, use the primitive "="
6305 if Is_Tagged_Type (Typl) then
6307 -- No need to do anything else compiling under restriction
6308 -- No_Dispatching_Calls. During the semantic analysis we
6309 -- already notified such violation.
6311 if Restriction_Active (No_Dispatching_Calls) then
6315 -- If this is derived from an untagged private type completed with
6316 -- a tagged type, it does not have a full view, so we use the
6317 -- primitive operations of the private type. This check should no
6318 -- longer be necessary when these types get their full views???
6320 if Is_Private_Type (A_Typ)
6321 and then not Is_Tagged_Type (A_Typ)
6322 and then Is_Derived_Type (A_Typ)
6323 and then No (Full_View (A_Typ))
6325 -- Search for equality operation, checking that the operands
6326 -- have the same type. Note that we must find a matching entry,
6327 -- or something is very wrong!
6329 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
6331 while Present (Prim) loop
6332 exit when Chars (Node (Prim)) = Name_Op_Eq
6333 and then Etype (First_Formal (Node (Prim))) =
6334 Etype (Next_Formal (First_Formal (Node (Prim))))
6336 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6341 pragma Assert (Present (Prim));
6342 Op_Name := Node (Prim);
6344 -- Find the type's predefined equality or an overriding
6345 -- user- defined equality. The reason for not simply calling
6346 -- Find_Prim_Op here is that there may be a user-defined
6347 -- overloaded equality op that precedes the equality that we want,
6348 -- so we have to explicitly search (e.g., there could be an
6349 -- equality with two different parameter types).
6352 if Is_Class_Wide_Type (Typl) then
6353 Typl := Root_Type (Typl);
6356 Prim := First_Elmt (Primitive_Operations (Typl));
6357 while Present (Prim) loop
6358 exit when Chars (Node (Prim)) = Name_Op_Eq
6359 and then Etype (First_Formal (Node (Prim))) =
6360 Etype (Next_Formal (First_Formal (Node (Prim))))
6362 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6367 pragma Assert (Present (Prim));
6368 Op_Name := Node (Prim);
6371 Build_Equality_Call (Op_Name);
6373 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
6374 -- predefined equality operator for a type which has a subcomponent
6375 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
6377 elsif Has_Unconstrained_UU_Component (Typl) then
6379 Make_Raise_Program_Error (Loc,
6380 Reason => PE_Unchecked_Union_Restriction));
6382 -- Prevent Gigi from generating incorrect code by rewriting the
6383 -- equality as a standard False.
6386 New_Occurrence_Of (Standard_False, Loc));
6388 elsif Is_Unchecked_Union (Typl) then
6390 -- If we can infer the discriminants of the operands, we make a
6391 -- call to the TSS equality function.
6393 if Has_Inferable_Discriminants (Lhs)
6395 Has_Inferable_Discriminants (Rhs)
6398 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6401 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
6402 -- the predefined equality operator for an Unchecked_Union type
6403 -- if either of the operands lack inferable discriminants.
6406 Make_Raise_Program_Error (Loc,
6407 Reason => PE_Unchecked_Union_Restriction));
6409 -- Prevent Gigi from generating incorrect code by rewriting
6410 -- the equality as a standard False.
6413 New_Occurrence_Of (Standard_False, Loc));
6417 -- If a type support function is present (for complex cases), use it
6419 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
6421 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6423 -- Otherwise expand the component by component equality. Note that
6424 -- we never use block-bit comparisons for records, because of the
6425 -- problems with gaps. The backend will often be able to recombine
6426 -- the separate comparisons that we generate here.
6429 Remove_Side_Effects (Lhs);
6430 Remove_Side_Effects (Rhs);
6432 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
6434 Insert_Actions (N, Bodies, Suppress => All_Checks);
6435 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6439 -- Test if result is known at compile time
6441 Rewrite_Comparison (N);
6443 -- If we still have comparison for Vax_Float, process it
6445 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
6446 Expand_Vax_Comparison (N);
6450 Optimize_Length_Comparison (N);
6453 -----------------------
6454 -- Expand_N_Op_Expon --
6455 -----------------------
6457 procedure Expand_N_Op_Expon (N : Node_Id) is
6458 Loc : constant Source_Ptr := Sloc (N);
6459 Typ : constant Entity_Id := Etype (N);
6460 Rtyp : constant Entity_Id := Root_Type (Typ);
6461 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
6462 Bastyp : constant Node_Id := Etype (Base);
6463 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
6464 Exptyp : constant Entity_Id := Etype (Exp);
6465 Ovflo : constant Boolean := Do_Overflow_Check (N);
6474 Binary_Op_Validity_Checks (N);
6476 -- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node
6478 if CodePeer_Mode or Alfa_Mode then
6482 -- If either operand is of a private type, then we have the use of an
6483 -- intrinsic operator, and we get rid of the privateness, by using root
6484 -- types of underlying types for the actual operation. Otherwise the
6485 -- private types will cause trouble if we expand multiplications or
6486 -- shifts etc. We also do this transformation if the result type is
6487 -- different from the base type.
6489 if Is_Private_Type (Etype (Base))
6490 or else Is_Private_Type (Typ)
6491 or else Is_Private_Type (Exptyp)
6492 or else Rtyp /= Root_Type (Bastyp)
6495 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
6496 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
6500 Unchecked_Convert_To (Typ,
6502 Left_Opnd => Unchecked_Convert_To (Bt, Base),
6503 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
6504 Analyze_And_Resolve (N, Typ);
6509 -- Test for case of known right argument
6511 if Compile_Time_Known_Value (Exp) then
6512 Expv := Expr_Value (Exp);
6514 -- We only fold small non-negative exponents. You might think we
6515 -- could fold small negative exponents for the real case, but we
6516 -- can't because we are required to raise Constraint_Error for
6517 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
6518 -- See ACVC test C4A012B.
6520 if Expv >= 0 and then Expv <= 4 then
6522 -- X ** 0 = 1 (or 1.0)
6526 -- Call Remove_Side_Effects to ensure that any side effects
6527 -- in the ignored left operand (in particular function calls
6528 -- to user defined functions) are properly executed.
6530 Remove_Side_Effects (Base);
6532 if Ekind (Typ) in Integer_Kind then
6533 Xnode := Make_Integer_Literal (Loc, Intval => 1);
6535 Xnode := Make_Real_Literal (Loc, Ureal_1);
6547 Make_Op_Multiply (Loc,
6548 Left_Opnd => Duplicate_Subexpr (Base),
6549 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6551 -- X ** 3 = X * X * X
6555 Make_Op_Multiply (Loc,
6557 Make_Op_Multiply (Loc,
6558 Left_Opnd => Duplicate_Subexpr (Base),
6559 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
6560 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6563 -- En : constant base'type := base * base;
6568 Temp := Make_Temporary (Loc, 'E', Base);
6570 Insert_Actions (N, New_List (
6571 Make_Object_Declaration (Loc,
6572 Defining_Identifier => Temp,
6573 Constant_Present => True,
6574 Object_Definition => New_Reference_To (Typ, Loc),
6576 Make_Op_Multiply (Loc,
6577 Left_Opnd => Duplicate_Subexpr (Base),
6578 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
6581 Make_Op_Multiply (Loc,
6582 Left_Opnd => New_Reference_To (Temp, Loc),
6583 Right_Opnd => New_Reference_To (Temp, Loc));
6587 Analyze_And_Resolve (N, Typ);
6592 -- Case of (2 ** expression) appearing as an argument of an integer
6593 -- multiplication, or as the right argument of a division of a non-
6594 -- negative integer. In such cases we leave the node untouched, setting
6595 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
6596 -- of the higher level node converts it into a shift.
6598 -- Another case is 2 ** N in any other context. We simply convert
6599 -- this to 1 * 2 ** N, and then the above transformation applies.
6601 -- Note: this transformation is not applicable for a modular type with
6602 -- a non-binary modulus in the multiplication case, since we get a wrong
6603 -- result if the shift causes an overflow before the modular reduction.
6605 if Nkind (Base) = N_Integer_Literal
6606 and then Intval (Base) = 2
6607 and then Is_Integer_Type (Root_Type (Exptyp))
6608 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
6609 and then Is_Unsigned_Type (Exptyp)
6612 -- First the multiply and divide cases
6614 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
6616 P : constant Node_Id := Parent (N);
6617 L : constant Node_Id := Left_Opnd (P);
6618 R : constant Node_Id := Right_Opnd (P);
6621 if (Nkind (P) = N_Op_Multiply
6622 and then not Non_Binary_Modulus (Typ)
6624 ((Is_Integer_Type (Etype (L)) and then R = N)
6626 (Is_Integer_Type (Etype (R)) and then L = N))
6627 and then not Do_Overflow_Check (P))
6629 (Nkind (P) = N_Op_Divide
6630 and then Is_Integer_Type (Etype (L))
6631 and then Is_Unsigned_Type (Etype (L))
6633 and then not Do_Overflow_Check (P))
6635 Set_Is_Power_Of_2_For_Shift (N);
6640 -- Now the other cases
6642 elsif not Non_Binary_Modulus (Typ) then
6644 Make_Op_Multiply (Loc,
6645 Left_Opnd => Make_Integer_Literal (Loc, 1),
6646 Right_Opnd => Relocate_Node (N)));
6647 Analyze_And_Resolve (N, Typ);
6652 -- Fall through if exponentiation must be done using a runtime routine
6654 -- First deal with modular case
6656 if Is_Modular_Integer_Type (Rtyp) then
6658 -- Non-binary case, we call the special exponentiation routine for
6659 -- the non-binary case, converting the argument to Long_Long_Integer
6660 -- and passing the modulus value. Then the result is converted back
6661 -- to the base type.
6663 if Non_Binary_Modulus (Rtyp) then
6666 Make_Function_Call (Loc,
6667 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
6668 Parameter_Associations => New_List (
6669 Convert_To (Standard_Integer, Base),
6670 Make_Integer_Literal (Loc, Modulus (Rtyp)),
6673 -- Binary case, in this case, we call one of two routines, either the
6674 -- unsigned integer case, or the unsigned long long integer case,
6675 -- with a final "and" operation to do the required mod.
6678 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
6679 Ent := RTE (RE_Exp_Unsigned);
6681 Ent := RTE (RE_Exp_Long_Long_Unsigned);
6688 Make_Function_Call (Loc,
6689 Name => New_Reference_To (Ent, Loc),
6690 Parameter_Associations => New_List (
6691 Convert_To (Etype (First_Formal (Ent)), Base),
6694 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
6698 -- Common exit point for modular type case
6700 Analyze_And_Resolve (N, Typ);
6703 -- Signed integer cases, done using either Integer or Long_Long_Integer.
6704 -- It is not worth having routines for Short_[Short_]Integer, since for
6705 -- most machines it would not help, and it would generate more code that
6706 -- might need certification when a certified run time is required.
6708 -- In the integer cases, we have two routines, one for when overflow
6709 -- checks are required, and one when they are not required, since there
6710 -- is a real gain in omitting checks on many machines.
6712 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
6713 or else (Rtyp = Base_Type (Standard_Long_Integer)
6715 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
6716 or else (Rtyp = Universal_Integer)
6718 Etyp := Standard_Long_Long_Integer;
6721 Rent := RE_Exp_Long_Long_Integer;
6723 Rent := RE_Exn_Long_Long_Integer;
6726 elsif Is_Signed_Integer_Type (Rtyp) then
6727 Etyp := Standard_Integer;
6730 Rent := RE_Exp_Integer;
6732 Rent := RE_Exn_Integer;
6735 -- Floating-point cases, always done using Long_Long_Float. We do not
6736 -- need separate routines for the overflow case here, since in the case
6737 -- of floating-point, we generate infinities anyway as a rule (either
6738 -- that or we automatically trap overflow), and if there is an infinity
6739 -- generated and a range check is required, the check will fail anyway.
6742 pragma Assert (Is_Floating_Point_Type (Rtyp));
6743 Etyp := Standard_Long_Long_Float;
6744 Rent := RE_Exn_Long_Long_Float;
6747 -- Common processing for integer cases and floating-point cases.
6748 -- If we are in the right type, we can call runtime routine directly
6751 and then Rtyp /= Universal_Integer
6752 and then Rtyp /= Universal_Real
6755 Make_Function_Call (Loc,
6756 Name => New_Reference_To (RTE (Rent), Loc),
6757 Parameter_Associations => New_List (Base, Exp)));
6759 -- Otherwise we have to introduce conversions (conversions are also
6760 -- required in the universal cases, since the runtime routine is
6761 -- typed using one of the standard types).
6766 Make_Function_Call (Loc,
6767 Name => New_Reference_To (RTE (Rent), Loc),
6768 Parameter_Associations => New_List (
6769 Convert_To (Etyp, Base),
6773 Analyze_And_Resolve (N, Typ);
6777 when RE_Not_Available =>
6779 end Expand_N_Op_Expon;
6781 --------------------
6782 -- Expand_N_Op_Ge --
6783 --------------------
6785 procedure Expand_N_Op_Ge (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_Gt --
6820 --------------------
6822 procedure Expand_N_Op_Gt (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_Le --
6857 --------------------
6859 procedure Expand_N_Op_Le (N : Node_Id) is
6860 Typ : constant Entity_Id := Etype (N);
6861 Op1 : constant Node_Id := Left_Opnd (N);
6862 Op2 : constant Node_Id := Right_Opnd (N);
6863 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6866 Binary_Op_Validity_Checks (N);
6868 if Is_Array_Type (Typ1) then
6869 Expand_Array_Comparison (N);
6873 if Is_Boolean_Type (Typ1) then
6874 Adjust_Condition (Op1);
6875 Adjust_Condition (Op2);
6876 Set_Etype (N, Standard_Boolean);
6877 Adjust_Result_Type (N, Typ);
6880 Rewrite_Comparison (N);
6882 -- If we still have comparison, and Vax_Float type, process it
6884 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6885 Expand_Vax_Comparison (N);
6889 Optimize_Length_Comparison (N);
6892 --------------------
6893 -- Expand_N_Op_Lt --
6894 --------------------
6896 procedure Expand_N_Op_Lt (N : Node_Id) is
6897 Typ : constant Entity_Id := Etype (N);
6898 Op1 : constant Node_Id := Left_Opnd (N);
6899 Op2 : constant Node_Id := Right_Opnd (N);
6900 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6903 Binary_Op_Validity_Checks (N);
6905 if Is_Array_Type (Typ1) then
6906 Expand_Array_Comparison (N);
6910 if Is_Boolean_Type (Typ1) then
6911 Adjust_Condition (Op1);
6912 Adjust_Condition (Op2);
6913 Set_Etype (N, Standard_Boolean);
6914 Adjust_Result_Type (N, Typ);
6917 Rewrite_Comparison (N);
6919 -- If we still have comparison, and Vax_Float type, process it
6921 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6922 Expand_Vax_Comparison (N);
6926 Optimize_Length_Comparison (N);
6929 -----------------------
6930 -- Expand_N_Op_Minus --
6931 -----------------------
6933 procedure Expand_N_Op_Minus (N : Node_Id) is
6934 Loc : constant Source_Ptr := Sloc (N);
6935 Typ : constant Entity_Id := Etype (N);
6938 Unary_Op_Validity_Checks (N);
6940 if not Backend_Overflow_Checks_On_Target
6941 and then Is_Signed_Integer_Type (Etype (N))
6942 and then Do_Overflow_Check (N)
6944 -- Software overflow checking expands -expr into (0 - expr)
6947 Make_Op_Subtract (Loc,
6948 Left_Opnd => Make_Integer_Literal (Loc, 0),
6949 Right_Opnd => Right_Opnd (N)));
6951 Analyze_And_Resolve (N, Typ);
6953 -- Vax floating-point types case
6955 elsif Vax_Float (Etype (N)) then
6956 Expand_Vax_Arith (N);
6958 end Expand_N_Op_Minus;
6960 ---------------------
6961 -- Expand_N_Op_Mod --
6962 ---------------------
6964 procedure Expand_N_Op_Mod (N : Node_Id) is
6965 Loc : constant Source_Ptr := Sloc (N);
6966 Typ : constant Entity_Id := Etype (N);
6967 Left : constant Node_Id := Left_Opnd (N);
6968 Right : constant Node_Id := Right_Opnd (N);
6969 DOC : constant Boolean := Do_Overflow_Check (N);
6970 DDC : constant Boolean := Do_Division_Check (N);
6980 pragma Warnings (Off, Lhi);
6983 Binary_Op_Validity_Checks (N);
6985 Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
6986 Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
6988 -- Convert mod to rem if operands are known non-negative. We do this
6989 -- since it is quite likely that this will improve the quality of code,
6990 -- (the operation now corresponds to the hardware remainder), and it
6991 -- does not seem likely that it could be harmful.
6993 if LOK and then Llo >= 0
6995 ROK and then Rlo >= 0
6998 Make_Op_Rem (Sloc (N),
6999 Left_Opnd => Left_Opnd (N),
7000 Right_Opnd => Right_Opnd (N)));
7002 -- Instead of reanalyzing the node we do the analysis manually. This
7003 -- avoids anomalies when the replacement is done in an instance and
7004 -- is epsilon more efficient.
7006 Set_Entity (N, Standard_Entity (S_Op_Rem));
7008 Set_Do_Overflow_Check (N, DOC);
7009 Set_Do_Division_Check (N, DDC);
7010 Expand_N_Op_Rem (N);
7013 -- Otherwise, normal mod processing
7016 if Is_Integer_Type (Etype (N)) then
7017 Apply_Divide_Check (N);
7020 -- Apply optimization x mod 1 = 0. We don't really need that with
7021 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
7022 -- certainly harmless.
7024 if Is_Integer_Type (Etype (N))
7025 and then Compile_Time_Known_Value (Right)
7026 and then Expr_Value (Right) = Uint_1
7028 -- Call Remove_Side_Effects to ensure that any side effects in
7029 -- the ignored left operand (in particular function calls to
7030 -- user defined functions) are properly executed.
7032 Remove_Side_Effects (Left);
7034 Rewrite (N, Make_Integer_Literal (Loc, 0));
7035 Analyze_And_Resolve (N, Typ);
7039 -- Deal with annoying case of largest negative number remainder
7040 -- minus one. Gigi does not handle this case correctly, because
7041 -- it generates a divide instruction which may trap in this case.
7043 -- In fact the check is quite easy, if the right operand is -1, then
7044 -- the mod value is always 0, and we can just ignore the left operand
7045 -- completely in this case.
7047 -- The operand type may be private (e.g. in the expansion of an
7048 -- intrinsic operation) so we must use the underlying type to get the
7049 -- bounds, and convert the literals explicitly.
7053 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
7055 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
7057 ((not LOK) or else (Llo = LLB))
7060 Make_Conditional_Expression (Loc,
7061 Expressions => New_List (
7063 Left_Opnd => Duplicate_Subexpr (Right),
7065 Unchecked_Convert_To (Typ,
7066 Make_Integer_Literal (Loc, -1))),
7067 Unchecked_Convert_To (Typ,
7068 Make_Integer_Literal (Loc, Uint_0)),
7069 Relocate_Node (N))));
7071 Set_Analyzed (Next (Next (First (Expressions (N)))));
7072 Analyze_And_Resolve (N, Typ);
7075 end Expand_N_Op_Mod;
7077 --------------------------
7078 -- Expand_N_Op_Multiply --
7079 --------------------------
7081 procedure Expand_N_Op_Multiply (N : Node_Id) is
7082 Loc : constant Source_Ptr := Sloc (N);
7083 Lop : constant Node_Id := Left_Opnd (N);
7084 Rop : constant Node_Id := Right_Opnd (N);
7086 Lp2 : constant Boolean :=
7087 Nkind (Lop) = N_Op_Expon
7088 and then Is_Power_Of_2_For_Shift (Lop);
7090 Rp2 : constant Boolean :=
7091 Nkind (Rop) = N_Op_Expon
7092 and then Is_Power_Of_2_For_Shift (Rop);
7094 Ltyp : constant Entity_Id := Etype (Lop);
7095 Rtyp : constant Entity_Id := Etype (Rop);
7096 Typ : Entity_Id := Etype (N);
7099 Binary_Op_Validity_Checks (N);
7101 -- Special optimizations for integer types
7103 if Is_Integer_Type (Typ) then
7105 -- N * 0 = 0 for integer types
7107 if Compile_Time_Known_Value (Rop)
7108 and then Expr_Value (Rop) = Uint_0
7110 -- Call Remove_Side_Effects to ensure that any side effects in
7111 -- the ignored left operand (in particular function calls to
7112 -- user defined functions) are properly executed.
7114 Remove_Side_Effects (Lop);
7116 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7117 Analyze_And_Resolve (N, Typ);
7121 -- Similar handling for 0 * N = 0
7123 if Compile_Time_Known_Value (Lop)
7124 and then Expr_Value (Lop) = Uint_0
7126 Remove_Side_Effects (Rop);
7127 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7128 Analyze_And_Resolve (N, Typ);
7132 -- N * 1 = 1 * N = N for integer types
7134 -- This optimisation is not done if we are going to
7135 -- rewrite the product 1 * 2 ** N to a shift.
7137 if Compile_Time_Known_Value (Rop)
7138 and then Expr_Value (Rop) = Uint_1
7144 elsif Compile_Time_Known_Value (Lop)
7145 and then Expr_Value (Lop) = Uint_1
7153 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
7154 -- Is_Power_Of_2_For_Shift is set means that we know that our left
7155 -- operand is an integer, as required for this to work.
7160 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
7164 Left_Opnd => Make_Integer_Literal (Loc, 2),
7167 Left_Opnd => Right_Opnd (Lop),
7168 Right_Opnd => Right_Opnd (Rop))));
7169 Analyze_And_Resolve (N, Typ);
7174 Make_Op_Shift_Left (Loc,
7177 Convert_To (Standard_Natural, Right_Opnd (Rop))));
7178 Analyze_And_Resolve (N, Typ);
7182 -- Same processing for the operands the other way round
7186 Make_Op_Shift_Left (Loc,
7189 Convert_To (Standard_Natural, Right_Opnd (Lop))));
7190 Analyze_And_Resolve (N, Typ);
7194 -- Do required fixup of universal fixed operation
7196 if Typ = Universal_Fixed then
7197 Fixup_Universal_Fixed_Operation (N);
7201 -- Multiplications with fixed-point results
7203 if Is_Fixed_Point_Type (Typ) then
7205 -- No special processing if Treat_Fixed_As_Integer is set, since from
7206 -- a semantic point of view such operations are simply integer
7207 -- operations and will be treated that way.
7209 if not Treat_Fixed_As_Integer (N) then
7211 -- Case of fixed * integer => fixed
7213 if Is_Integer_Type (Rtyp) then
7214 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
7216 -- Case of integer * fixed => fixed
7218 elsif Is_Integer_Type (Ltyp) then
7219 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
7221 -- Case of fixed * fixed => fixed
7224 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
7228 -- Other cases of multiplication of fixed-point operands. Again we
7229 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
7231 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
7232 and then not Treat_Fixed_As_Integer (N)
7234 if Is_Integer_Type (Typ) then
7235 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
7237 pragma Assert (Is_Floating_Point_Type (Typ));
7238 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
7241 -- Mixed-mode operations can appear in a non-static universal context,
7242 -- in which case the integer argument must be converted explicitly.
7244 elsif Typ = Universal_Real
7245 and then Is_Integer_Type (Rtyp)
7247 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
7249 Analyze_And_Resolve (Rop, Universal_Real);
7251 elsif Typ = Universal_Real
7252 and then Is_Integer_Type (Ltyp)
7254 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
7256 Analyze_And_Resolve (Lop, Universal_Real);
7258 -- Non-fixed point cases, check software overflow checking required
7260 elsif Is_Signed_Integer_Type (Etype (N)) then
7261 Apply_Arithmetic_Overflow_Check (N);
7263 -- Deal with VAX float case
7265 elsif Vax_Float (Typ) then
7266 Expand_Vax_Arith (N);
7269 end Expand_N_Op_Multiply;
7271 --------------------
7272 -- Expand_N_Op_Ne --
7273 --------------------
7275 procedure Expand_N_Op_Ne (N : Node_Id) is
7276 Typ : constant Entity_Id := Etype (Left_Opnd (N));
7279 -- Case of elementary type with standard operator
7281 if Is_Elementary_Type (Typ)
7282 and then Sloc (Entity (N)) = Standard_Location
7284 Binary_Op_Validity_Checks (N);
7286 -- Boolean types (requiring handling of non-standard case)
7288 if Is_Boolean_Type (Typ) then
7289 Adjust_Condition (Left_Opnd (N));
7290 Adjust_Condition (Right_Opnd (N));
7291 Set_Etype (N, Standard_Boolean);
7292 Adjust_Result_Type (N, Typ);
7295 Rewrite_Comparison (N);
7297 -- If we still have comparison for Vax_Float, process it
7299 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
7300 Expand_Vax_Comparison (N);
7304 -- For all cases other than elementary types, we rewrite node as the
7305 -- negation of an equality operation, and reanalyze. The equality to be
7306 -- used is defined in the same scope and has the same signature. This
7307 -- signature must be set explicitly since in an instance it may not have
7308 -- the same visibility as in the generic unit. This avoids duplicating
7309 -- or factoring the complex code for record/array equality tests etc.
7313 Loc : constant Source_Ptr := Sloc (N);
7315 Ne : constant Entity_Id := Entity (N);
7318 Binary_Op_Validity_Checks (N);
7324 Left_Opnd => Left_Opnd (N),
7325 Right_Opnd => Right_Opnd (N)));
7326 Set_Paren_Count (Right_Opnd (Neg), 1);
7328 if Scope (Ne) /= Standard_Standard then
7329 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
7332 -- For navigation purposes, we want to treat the inequality as an
7333 -- implicit reference to the corresponding equality. Preserve the
7334 -- Comes_From_ source flag to generate proper Xref entries.
7336 Preserve_Comes_From_Source (Neg, N);
7337 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
7339 Analyze_And_Resolve (N, Standard_Boolean);
7343 Optimize_Length_Comparison (N);
7346 ---------------------
7347 -- Expand_N_Op_Not --
7348 ---------------------
7350 -- If the argument is other than a Boolean array type, there is no special
7351 -- expansion required, except for VMS operations on signed integers.
7353 -- For the packed case, we call the special routine in Exp_Pakd, except
7354 -- that if the component size is greater than one, we use the standard
7355 -- routine generating a gruesome loop (it is so peculiar to have packed
7356 -- arrays with non-standard Boolean representations anyway, so it does not
7357 -- matter that we do not handle this case efficiently).
7359 -- For the unpacked case (and for the special packed case where we have non
7360 -- standard Booleans, as discussed above), we generate and insert into the
7361 -- tree the following function definition:
7363 -- function Nnnn (A : arr) is
7366 -- for J in a'range loop
7367 -- B (J) := not A (J);
7372 -- Here arr is the actual subtype of the parameter (and hence always
7373 -- constrained). Then we replace the not with a call to this function.
7375 procedure Expand_N_Op_Not (N : Node_Id) is
7376 Loc : constant Source_Ptr := Sloc (N);
7377 Typ : constant Entity_Id := Etype (N);
7386 Func_Name : Entity_Id;
7387 Loop_Statement : Node_Id;
7390 Unary_Op_Validity_Checks (N);
7392 -- For boolean operand, deal with non-standard booleans
7394 if Is_Boolean_Type (Typ) then
7395 Adjust_Condition (Right_Opnd (N));
7396 Set_Etype (N, Standard_Boolean);
7397 Adjust_Result_Type (N, Typ);
7401 -- For the VMS "not" on signed integer types, use conversion to and from
7402 -- a predefined modular type.
7404 if Is_VMS_Operator (Entity (N)) then
7410 -- If this is a derived type, retrieve original VMS type so that
7411 -- the proper sized type is used for intermediate values.
7413 if Is_Derived_Type (Typ) then
7414 Rtyp := First_Subtype (Etype (Typ));
7419 -- The proper unsigned type must have a size compatible with the
7420 -- operand, to prevent misalignment.
7422 if RM_Size (Rtyp) <= 8 then
7423 Utyp := RTE (RE_Unsigned_8);
7425 elsif RM_Size (Rtyp) <= 16 then
7426 Utyp := RTE (RE_Unsigned_16);
7428 elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
7429 Utyp := RTE (RE_Unsigned_32);
7432 Utyp := RTE (RE_Long_Long_Unsigned);
7436 Unchecked_Convert_To (Typ,
7438 Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
7439 Analyze_And_Resolve (N, Typ);
7444 -- Only array types need any other processing
7446 if not Is_Array_Type (Typ) then
7450 -- Case of array operand. If bit packed with a component size of 1,
7451 -- handle it in Exp_Pakd if the operand is known to be aligned.
7453 if Is_Bit_Packed_Array (Typ)
7454 and then Component_Size (Typ) = 1
7455 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
7457 Expand_Packed_Not (N);
7461 -- Case of array operand which is not bit-packed. If the context is
7462 -- a safe assignment, call in-place operation, If context is a larger
7463 -- boolean expression in the context of a safe assignment, expansion is
7464 -- done by enclosing operation.
7466 Opnd := Relocate_Node (Right_Opnd (N));
7467 Convert_To_Actual_Subtype (Opnd);
7468 Arr := Etype (Opnd);
7469 Ensure_Defined (Arr, N);
7470 Silly_Boolean_Array_Not_Test (N, Arr);
7472 if Nkind (Parent (N)) = N_Assignment_Statement then
7473 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
7474 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7477 -- Special case the negation of a binary operation
7479 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
7480 and then Safe_In_Place_Array_Op
7481 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
7483 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7487 elsif Nkind (Parent (N)) in N_Binary_Op
7488 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
7491 Op1 : constant Node_Id := Left_Opnd (Parent (N));
7492 Op2 : constant Node_Id := Right_Opnd (Parent (N));
7493 Lhs : constant Node_Id := Name (Parent (Parent (N)));
7496 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
7498 -- (not A) op (not B) can be reduced to a single call
7500 if N = Op1 and then Nkind (Op2) = N_Op_Not then
7503 elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
7506 -- A xor (not B) can also be special-cased
7508 elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
7515 A := Make_Defining_Identifier (Loc, Name_uA);
7516 B := Make_Defining_Identifier (Loc, Name_uB);
7517 J := Make_Defining_Identifier (Loc, Name_uJ);
7520 Make_Indexed_Component (Loc,
7521 Prefix => New_Reference_To (A, Loc),
7522 Expressions => New_List (New_Reference_To (J, Loc)));
7525 Make_Indexed_Component (Loc,
7526 Prefix => New_Reference_To (B, Loc),
7527 Expressions => New_List (New_Reference_To (J, Loc)));
7530 Make_Implicit_Loop_Statement (N,
7531 Identifier => Empty,
7534 Make_Iteration_Scheme (Loc,
7535 Loop_Parameter_Specification =>
7536 Make_Loop_Parameter_Specification (Loc,
7537 Defining_Identifier => J,
7538 Discrete_Subtype_Definition =>
7539 Make_Attribute_Reference (Loc,
7540 Prefix => Make_Identifier (Loc, Chars (A)),
7541 Attribute_Name => Name_Range))),
7543 Statements => New_List (
7544 Make_Assignment_Statement (Loc,
7546 Expression => Make_Op_Not (Loc, A_J))));
7548 Func_Name := Make_Temporary (Loc, 'N');
7549 Set_Is_Inlined (Func_Name);
7552 Make_Subprogram_Body (Loc,
7554 Make_Function_Specification (Loc,
7555 Defining_Unit_Name => Func_Name,
7556 Parameter_Specifications => New_List (
7557 Make_Parameter_Specification (Loc,
7558 Defining_Identifier => A,
7559 Parameter_Type => New_Reference_To (Typ, Loc))),
7560 Result_Definition => New_Reference_To (Typ, Loc)),
7562 Declarations => New_List (
7563 Make_Object_Declaration (Loc,
7564 Defining_Identifier => B,
7565 Object_Definition => New_Reference_To (Arr, Loc))),
7567 Handled_Statement_Sequence =>
7568 Make_Handled_Sequence_Of_Statements (Loc,
7569 Statements => New_List (
7571 Make_Simple_Return_Statement (Loc,
7572 Expression => Make_Identifier (Loc, Chars (B)))))));
7575 Make_Function_Call (Loc,
7576 Name => New_Reference_To (Func_Name, Loc),
7577 Parameter_Associations => New_List (Opnd)));
7579 Analyze_And_Resolve (N, Typ);
7580 end Expand_N_Op_Not;
7582 --------------------
7583 -- Expand_N_Op_Or --
7584 --------------------
7586 procedure Expand_N_Op_Or (N : Node_Id) is
7587 Typ : constant Entity_Id := Etype (N);
7590 Binary_Op_Validity_Checks (N);
7592 if Is_Array_Type (Etype (N)) then
7593 Expand_Boolean_Operator (N);
7595 elsif Is_Boolean_Type (Etype (N)) then
7597 -- Replace OR by OR ELSE if Short_Circuit_And_Or active and the type
7598 -- is standard Boolean (do not mess with AND that uses a non-standard
7599 -- Boolean type, because something strange is going on).
7601 if Short_Circuit_And_Or and then Typ = Standard_Boolean then
7603 Make_Or_Else (Sloc (N),
7604 Left_Opnd => Relocate_Node (Left_Opnd (N)),
7605 Right_Opnd => Relocate_Node (Right_Opnd (N))));
7606 Analyze_And_Resolve (N, Typ);
7608 -- Otherwise, adjust conditions
7611 Adjust_Condition (Left_Opnd (N));
7612 Adjust_Condition (Right_Opnd (N));
7613 Set_Etype (N, Standard_Boolean);
7614 Adjust_Result_Type (N, Typ);
7617 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7618 Expand_Intrinsic_Call (N, Entity (N));
7623 ----------------------
7624 -- Expand_N_Op_Plus --
7625 ----------------------
7627 procedure Expand_N_Op_Plus (N : Node_Id) is
7629 Unary_Op_Validity_Checks (N);
7630 end Expand_N_Op_Plus;
7632 ---------------------
7633 -- Expand_N_Op_Rem --
7634 ---------------------
7636 procedure Expand_N_Op_Rem (N : Node_Id) is
7637 Loc : constant Source_Ptr := Sloc (N);
7638 Typ : constant Entity_Id := Etype (N);
7640 Left : constant Node_Id := Left_Opnd (N);
7641 Right : constant Node_Id := Right_Opnd (N);
7649 -- Set if corresponding operand can be negative
7651 pragma Unreferenced (Hi);
7654 Binary_Op_Validity_Checks (N);
7656 if Is_Integer_Type (Etype (N)) then
7657 Apply_Divide_Check (N);
7660 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
7661 -- but it is useful with other back ends (e.g. AAMP), and is certainly
7664 if Is_Integer_Type (Etype (N))
7665 and then Compile_Time_Known_Value (Right)
7666 and then Expr_Value (Right) = Uint_1
7668 -- Call Remove_Side_Effects to ensure that any side effects in the
7669 -- ignored left operand (in particular function calls to user defined
7670 -- functions) are properly executed.
7672 Remove_Side_Effects (Left);
7674 Rewrite (N, Make_Integer_Literal (Loc, 0));
7675 Analyze_And_Resolve (N, Typ);
7679 -- Deal with annoying case of largest negative number remainder minus
7680 -- one. Gigi does not handle this case correctly, because it generates
7681 -- a divide instruction which may trap in this case.
7683 -- In fact the check is quite easy, if the right operand is -1, then
7684 -- the remainder is always 0, and we can just ignore the left operand
7685 -- completely in this case.
7687 Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
7688 Lneg := (not OK) or else Lo < 0;
7690 Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
7691 Rneg := (not OK) or else Lo < 0;
7693 -- We won't mess with trying to find out if the left operand can really
7694 -- be the largest negative number (that's a pain in the case of private
7695 -- types and this is really marginal). We will just assume that we need
7696 -- the test if the left operand can be negative at all.
7698 if Lneg and Rneg then
7700 Make_Conditional_Expression (Loc,
7701 Expressions => New_List (
7703 Left_Opnd => Duplicate_Subexpr (Right),
7705 Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
7707 Unchecked_Convert_To (Typ,
7708 Make_Integer_Literal (Loc, Uint_0)),
7710 Relocate_Node (N))));
7712 Set_Analyzed (Next (Next (First (Expressions (N)))));
7713 Analyze_And_Resolve (N, Typ);
7715 end Expand_N_Op_Rem;
7717 -----------------------------
7718 -- Expand_N_Op_Rotate_Left --
7719 -----------------------------
7721 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
7723 Binary_Op_Validity_Checks (N);
7724 end Expand_N_Op_Rotate_Left;
7726 ------------------------------
7727 -- Expand_N_Op_Rotate_Right --
7728 ------------------------------
7730 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
7732 Binary_Op_Validity_Checks (N);
7733 end Expand_N_Op_Rotate_Right;
7735 ----------------------------
7736 -- Expand_N_Op_Shift_Left --
7737 ----------------------------
7739 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
7741 Binary_Op_Validity_Checks (N);
7742 end Expand_N_Op_Shift_Left;
7744 -----------------------------
7745 -- Expand_N_Op_Shift_Right --
7746 -----------------------------
7748 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
7750 Binary_Op_Validity_Checks (N);
7751 end Expand_N_Op_Shift_Right;
7753 ----------------------------------------
7754 -- Expand_N_Op_Shift_Right_Arithmetic --
7755 ----------------------------------------
7757 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
7759 Binary_Op_Validity_Checks (N);
7760 end Expand_N_Op_Shift_Right_Arithmetic;
7762 --------------------------
7763 -- Expand_N_Op_Subtract --
7764 --------------------------
7766 procedure Expand_N_Op_Subtract (N : Node_Id) is
7767 Typ : constant Entity_Id := Etype (N);
7770 Binary_Op_Validity_Checks (N);
7772 -- N - 0 = N for integer types
7774 if Is_Integer_Type (Typ)
7775 and then Compile_Time_Known_Value (Right_Opnd (N))
7776 and then Expr_Value (Right_Opnd (N)) = 0
7778 Rewrite (N, Left_Opnd (N));
7782 -- Arithmetic overflow checks for signed integer/fixed point types
7784 if Is_Signed_Integer_Type (Typ)
7786 Is_Fixed_Point_Type (Typ)
7788 Apply_Arithmetic_Overflow_Check (N);
7790 -- VAX floating-point types case
7792 elsif Vax_Float (Typ) then
7793 Expand_Vax_Arith (N);
7795 end Expand_N_Op_Subtract;
7797 ---------------------
7798 -- Expand_N_Op_Xor --
7799 ---------------------
7801 procedure Expand_N_Op_Xor (N : Node_Id) is
7802 Typ : constant Entity_Id := Etype (N);
7805 Binary_Op_Validity_Checks (N);
7807 if Is_Array_Type (Etype (N)) then
7808 Expand_Boolean_Operator (N);
7810 elsif Is_Boolean_Type (Etype (N)) then
7811 Adjust_Condition (Left_Opnd (N));
7812 Adjust_Condition (Right_Opnd (N));
7813 Set_Etype (N, Standard_Boolean);
7814 Adjust_Result_Type (N, Typ);
7816 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7817 Expand_Intrinsic_Call (N, Entity (N));
7820 end Expand_N_Op_Xor;
7822 ----------------------
7823 -- Expand_N_Or_Else --
7824 ----------------------
7826 procedure Expand_N_Or_Else (N : Node_Id)
7827 renames Expand_Short_Circuit_Operator;
7829 -----------------------------------
7830 -- Expand_N_Qualified_Expression --
7831 -----------------------------------
7833 procedure Expand_N_Qualified_Expression (N : Node_Id) is
7834 Operand : constant Node_Id := Expression (N);
7835 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
7838 -- Do validity check if validity checking operands
7840 if Validity_Checks_On
7841 and then Validity_Check_Operands
7843 Ensure_Valid (Operand);
7846 -- Apply possible constraint check
7848 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
7850 if Do_Range_Check (Operand) then
7851 Set_Do_Range_Check (Operand, False);
7852 Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
7854 end Expand_N_Qualified_Expression;
7856 ------------------------------------
7857 -- Expand_N_Quantified_Expression --
7858 ------------------------------------
7862 -- for all X in range => Cond
7867 -- for X in range loop
7874 -- Conversely, an existentially quantified expression:
7876 -- for some X in range => Cond
7881 -- for X in range loop
7888 -- In both cases, the iteration may be over a container in which case it is
7889 -- given by an iterator specification, not a loop parameter specification.
7891 procedure Expand_N_Quantified_Expression (N : Node_Id) is
7892 Loc : constant Source_Ptr := Sloc (N);
7893 Is_Universal : constant Boolean := All_Present (N);
7894 Actions : constant List_Id := New_List;
7895 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
7903 Make_Object_Declaration (Loc,
7904 Defining_Identifier => Tnn,
7905 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
7907 New_Occurrence_Of (Boolean_Literals (Is_Universal), Loc));
7908 Append_To (Actions, Decl);
7910 Cond := Relocate_Node (Condition (N));
7912 -- Reset flag analyzed in the condition to force its analysis. Required
7913 -- since the previous analysis was done with expansion disabled (see
7914 -- Resolve_Quantified_Expression) and hence checks were not inserted
7915 -- and record comparisons have not been expanded.
7917 Reset_Analyzed_Flags (Cond);
7919 if Is_Universal then
7920 Cond := Make_Op_Not (Loc, Cond);
7924 Make_Implicit_If_Statement (N,
7926 Then_Statements => New_List (
7927 Make_Assignment_Statement (Loc,
7928 Name => New_Occurrence_Of (Tnn, Loc),
7930 New_Occurrence_Of (Boolean_Literals (not Is_Universal), Loc)),
7931 Make_Exit_Statement (Loc)));
7933 if Present (Loop_Parameter_Specification (N)) then
7935 Make_Iteration_Scheme (Loc,
7936 Loop_Parameter_Specification =>
7937 Loop_Parameter_Specification (N));
7940 Make_Iteration_Scheme (Loc,
7941 Iterator_Specification => Iterator_Specification (N));
7945 Make_Loop_Statement (Loc,
7946 Iteration_Scheme => I_Scheme,
7947 Statements => New_List (Test),
7948 End_Label => Empty));
7951 Make_Expression_With_Actions (Loc,
7952 Expression => New_Occurrence_Of (Tnn, Loc),
7953 Actions => Actions));
7955 Analyze_And_Resolve (N, Standard_Boolean);
7956 end Expand_N_Quantified_Expression;
7958 ---------------------------------
7959 -- Expand_N_Selected_Component --
7960 ---------------------------------
7962 -- If the selector is a discriminant of a concurrent object, rewrite the
7963 -- prefix to denote the corresponding record type.
7965 procedure Expand_N_Selected_Component (N : Node_Id) is
7966 Loc : constant Source_Ptr := Sloc (N);
7967 Par : constant Node_Id := Parent (N);
7968 P : constant Node_Id := Prefix (N);
7969 Ptyp : Entity_Id := Underlying_Type (Etype (P));
7975 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
7976 -- Gigi needs a temporary for prefixes that depend on a discriminant,
7977 -- unless the context of an assignment can provide size information.
7978 -- Don't we have a general routine that does this???
7980 function Is_Subtype_Declaration return Boolean;
7981 -- The replacement of a discriminant reference by its value is required
7982 -- if this is part of the initialization of an temporary generated by a
7983 -- change of representation. This shows up as the construction of a
7984 -- discriminant constraint for a subtype declared at the same point as
7985 -- the entity in the prefix of the selected component. We recognize this
7986 -- case when the context of the reference is:
7987 -- subtype ST is T(Obj.D);
7988 -- where the entity for Obj comes from source, and ST has the same sloc.
7990 -----------------------
7991 -- In_Left_Hand_Side --
7992 -----------------------
7994 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
7996 return (Nkind (Parent (Comp)) = N_Assignment_Statement
7997 and then Comp = Name (Parent (Comp)))
7998 or else (Present (Parent (Comp))
7999 and then Nkind (Parent (Comp)) in N_Subexpr
8000 and then In_Left_Hand_Side (Parent (Comp)));
8001 end In_Left_Hand_Side;
8003 -----------------------------
8004 -- Is_Subtype_Declaration --
8005 -----------------------------
8007 function Is_Subtype_Declaration return Boolean is
8008 Par : constant Node_Id := Parent (N);
8011 Nkind (Par) = N_Index_Or_Discriminant_Constraint
8012 and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration
8013 and then Comes_From_Source (Entity (Prefix (N)))
8014 and then Sloc (Par) = Sloc (Entity (Prefix (N)));
8015 end Is_Subtype_Declaration;
8017 -- Start of processing for Expand_N_Selected_Component
8020 -- Insert explicit dereference if required
8022 if Is_Access_Type (Ptyp) then
8024 -- First set prefix type to proper access type, in case it currently
8025 -- has a private (non-access) view of this type.
8027 Set_Etype (P, Ptyp);
8029 Insert_Explicit_Dereference (P);
8030 Analyze_And_Resolve (P, Designated_Type (Ptyp));
8032 if Ekind (Etype (P)) = E_Private_Subtype
8033 and then Is_For_Access_Subtype (Etype (P))
8035 Set_Etype (P, Base_Type (Etype (P)));
8041 -- Deal with discriminant check required
8043 if Do_Discriminant_Check (N) then
8045 -- Present the discriminant checking function to the backend, so that
8046 -- it can inline the call to the function.
8049 (Discriminant_Checking_Func
8050 (Original_Record_Component (Entity (Selector_Name (N)))));
8052 -- Now reset the flag and generate the call
8054 Set_Do_Discriminant_Check (N, False);
8055 Generate_Discriminant_Check (N);
8058 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
8059 -- function, then additional actuals must be passed.
8061 if Ada_Version >= Ada_2005
8062 and then Is_Build_In_Place_Function_Call (P)
8064 Make_Build_In_Place_Call_In_Anonymous_Context (P);
8067 -- Gigi cannot handle unchecked conversions that are the prefix of a
8068 -- selected component with discriminants. This must be checked during
8069 -- expansion, because during analysis the type of the selector is not
8070 -- known at the point the prefix is analyzed. If the conversion is the
8071 -- target of an assignment, then we cannot force the evaluation.
8073 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
8074 and then Has_Discriminants (Etype (N))
8075 and then not In_Left_Hand_Side (N)
8077 Force_Evaluation (Prefix (N));
8080 -- Remaining processing applies only if selector is a discriminant
8082 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
8084 -- If the selector is a discriminant of a constrained record type,
8085 -- we may be able to rewrite the expression with the actual value
8086 -- of the discriminant, a useful optimization in some cases.
8088 if Is_Record_Type (Ptyp)
8089 and then Has_Discriminants (Ptyp)
8090 and then Is_Constrained (Ptyp)
8092 -- Do this optimization for discrete types only, and not for
8093 -- access types (access discriminants get us into trouble!)
8095 if not Is_Discrete_Type (Etype (N)) then
8098 -- Don't do this on the left hand of an assignment statement.
8099 -- Normally one would think that references like this would not
8100 -- occur, but they do in generated code, and mean that we really
8101 -- do want to assign the discriminant!
8103 elsif Nkind (Par) = N_Assignment_Statement
8104 and then Name (Par) = N
8108 -- Don't do this optimization for the prefix of an attribute or
8109 -- the name of an object renaming declaration since these are
8110 -- contexts where we do not want the value anyway.
8112 elsif (Nkind (Par) = N_Attribute_Reference
8113 and then Prefix (Par) = N)
8114 or else Is_Renamed_Object (N)
8118 -- Don't do this optimization if we are within the code for a
8119 -- discriminant check, since the whole point of such a check may
8120 -- be to verify the condition on which the code below depends!
8122 elsif Is_In_Discriminant_Check (N) then
8125 -- Green light to see if we can do the optimization. There is
8126 -- still one condition that inhibits the optimization below but
8127 -- now is the time to check the particular discriminant.
8130 -- Loop through discriminants to find the matching discriminant
8131 -- constraint to see if we can copy it.
8133 Disc := First_Discriminant (Ptyp);
8134 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
8135 Discr_Loop : while Present (Dcon) loop
8136 Dval := Node (Dcon);
8138 -- Check if this is the matching discriminant and if the
8139 -- discriminant value is simple enough to make sense to
8140 -- copy. We don't want to copy complex expressions, and
8141 -- indeed to do so can cause trouble (before we put in
8142 -- this guard, a discriminant expression containing an
8143 -- AND THEN was copied, causing problems for coverage
8146 -- However, if the reference is part of the initialization
8147 -- code generated for an object declaration, we must use
8148 -- the discriminant value from the subtype constraint,
8149 -- because the selected component may be a reference to the
8150 -- object being initialized, whose discriminant is not yet
8151 -- set. This only happens in complex cases involving changes
8152 -- or representation.
8154 if Disc = Entity (Selector_Name (N))
8155 and then (Is_Entity_Name (Dval)
8156 or else Compile_Time_Known_Value (Dval)
8157 or else Is_Subtype_Declaration)
8159 -- Here we have the matching discriminant. Check for
8160 -- the case of a discriminant of a component that is
8161 -- constrained by an outer discriminant, which cannot
8162 -- be optimized away.
8164 if Denotes_Discriminant
8165 (Dval, Check_Concurrent => True)
8169 elsif Nkind (Original_Node (Dval)) = N_Selected_Component
8171 Denotes_Discriminant
8172 (Selector_Name (Original_Node (Dval)), True)
8176 -- Do not retrieve value if constraint is not static. It
8177 -- is generally not useful, and the constraint may be a
8178 -- rewritten outer discriminant in which case it is in
8181 elsif Is_Entity_Name (Dval)
8182 and then Nkind (Parent (Entity (Dval))) =
8183 N_Object_Declaration
8184 and then Present (Expression (Parent (Entity (Dval))))
8186 not Is_Static_Expression
8187 (Expression (Parent (Entity (Dval))))
8191 -- In the context of a case statement, the expression may
8192 -- have the base type of the discriminant, and we need to
8193 -- preserve the constraint to avoid spurious errors on
8196 elsif Nkind (Parent (N)) = N_Case_Statement
8197 and then Etype (Dval) /= Etype (Disc)
8200 Make_Qualified_Expression (Loc,
8202 New_Occurrence_Of (Etype (Disc), Loc),
8204 New_Copy_Tree (Dval)));
8205 Analyze_And_Resolve (N, Etype (Disc));
8207 -- In case that comes out as a static expression,
8208 -- reset it (a selected component is never static).
8210 Set_Is_Static_Expression (N, False);
8213 -- Otherwise we can just copy the constraint, but the
8214 -- result is certainly not static! In some cases the
8215 -- discriminant constraint has been analyzed in the
8216 -- context of the original subtype indication, but for
8217 -- itypes the constraint might not have been analyzed
8218 -- yet, and this must be done now.
8221 Rewrite (N, New_Copy_Tree (Dval));
8222 Analyze_And_Resolve (N);
8223 Set_Is_Static_Expression (N, False);
8229 Next_Discriminant (Disc);
8230 end loop Discr_Loop;
8232 -- Note: the above loop should always find a matching
8233 -- discriminant, but if it does not, we just missed an
8234 -- optimization due to some glitch (perhaps a previous
8235 -- error), so ignore.
8240 -- The only remaining processing is in the case of a discriminant of
8241 -- a concurrent object, where we rewrite the prefix to denote the
8242 -- corresponding record type. If the type is derived and has renamed
8243 -- discriminants, use corresponding discriminant, which is the one
8244 -- that appears in the corresponding record.
8246 if not Is_Concurrent_Type (Ptyp) then
8250 Disc := Entity (Selector_Name (N));
8252 if Is_Derived_Type (Ptyp)
8253 and then Present (Corresponding_Discriminant (Disc))
8255 Disc := Corresponding_Discriminant (Disc);
8259 Make_Selected_Component (Loc,
8261 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
8263 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
8268 end Expand_N_Selected_Component;
8270 --------------------
8271 -- Expand_N_Slice --
8272 --------------------
8274 procedure Expand_N_Slice (N : Node_Id) is
8275 Loc : constant Source_Ptr := Sloc (N);
8276 Typ : constant Entity_Id := Etype (N);
8277 Pfx : constant Node_Id := Prefix (N);
8278 Ptp : Entity_Id := Etype (Pfx);
8280 function Is_Procedure_Actual (N : Node_Id) return Boolean;
8281 -- Check whether the argument is an actual for a procedure call, in
8282 -- which case the expansion of a bit-packed slice is deferred until the
8283 -- call itself is expanded. The reason this is required is that we might
8284 -- have an IN OUT or OUT parameter, and the copy out is essential, and
8285 -- that copy out would be missed if we created a temporary here in
8286 -- Expand_N_Slice. Note that we don't bother to test specifically for an
8287 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
8288 -- is harmless to defer expansion in the IN case, since the call
8289 -- processing will still generate the appropriate copy in operation,
8290 -- which will take care of the slice.
8292 procedure Make_Temporary_For_Slice;
8293 -- Create a named variable for the value of the slice, in cases where
8294 -- the back-end cannot handle it properly, e.g. when packed types or
8295 -- unaligned slices are involved.
8297 -------------------------
8298 -- Is_Procedure_Actual --
8299 -------------------------
8301 function Is_Procedure_Actual (N : Node_Id) return Boolean is
8302 Par : Node_Id := Parent (N);
8306 -- If our parent is a procedure call we can return
8308 if Nkind (Par) = N_Procedure_Call_Statement then
8311 -- If our parent is a type conversion, keep climbing the tree,
8312 -- since a type conversion can be a procedure actual. Also keep
8313 -- climbing if parameter association or a qualified expression,
8314 -- since these are additional cases that do can appear on
8315 -- procedure actuals.
8317 elsif Nkind_In (Par, N_Type_Conversion,
8318 N_Parameter_Association,
8319 N_Qualified_Expression)
8321 Par := Parent (Par);
8323 -- Any other case is not what we are looking for
8329 end Is_Procedure_Actual;
8331 ------------------------------
8332 -- Make_Temporary_For_Slice --
8333 ------------------------------
8335 procedure Make_Temporary_For_Slice is
8337 Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
8341 Make_Object_Declaration (Loc,
8342 Defining_Identifier => Ent,
8343 Object_Definition => New_Occurrence_Of (Typ, Loc));
8345 Set_No_Initialization (Decl);
8347 Insert_Actions (N, New_List (
8349 Make_Assignment_Statement (Loc,
8350 Name => New_Occurrence_Of (Ent, Loc),
8351 Expression => Relocate_Node (N))));
8353 Rewrite (N, New_Occurrence_Of (Ent, Loc));
8354 Analyze_And_Resolve (N, Typ);
8355 end Make_Temporary_For_Slice;
8357 -- Start of processing for Expand_N_Slice
8360 -- Special handling for access types
8362 if Is_Access_Type (Ptp) then
8364 Ptp := Designated_Type (Ptp);
8367 Make_Explicit_Dereference (Sloc (N),
8368 Prefix => Relocate_Node (Pfx)));
8370 Analyze_And_Resolve (Pfx, Ptp);
8373 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
8374 -- function, then additional actuals must be passed.
8376 if Ada_Version >= Ada_2005
8377 and then Is_Build_In_Place_Function_Call (Pfx)
8379 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
8382 -- The remaining case to be handled is packed slices. We can leave
8383 -- packed slices as they are in the following situations:
8385 -- 1. Right or left side of an assignment (we can handle this
8386 -- situation correctly in the assignment statement expansion).
8388 -- 2. Prefix of indexed component (the slide is optimized away in this
8389 -- case, see the start of Expand_N_Slice.)
8391 -- 3. Object renaming declaration, since we want the name of the
8392 -- slice, not the value.
8394 -- 4. Argument to procedure call, since copy-in/copy-out handling may
8395 -- be required, and this is handled in the expansion of call
8398 -- 5. Prefix of an address attribute (this is an error which is caught
8399 -- elsewhere, and the expansion would interfere with generating the
8402 if not Is_Packed (Typ) then
8404 -- Apply transformation for actuals of a function call, where
8405 -- Expand_Actuals is not used.
8407 if Nkind (Parent (N)) = N_Function_Call
8408 and then Is_Possibly_Unaligned_Slice (N)
8410 Make_Temporary_For_Slice;
8413 elsif Nkind (Parent (N)) = N_Assignment_Statement
8414 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
8415 and then Parent (N) = Name (Parent (Parent (N))))
8419 elsif Nkind (Parent (N)) = N_Indexed_Component
8420 or else Is_Renamed_Object (N)
8421 or else Is_Procedure_Actual (N)
8425 elsif Nkind (Parent (N)) = N_Attribute_Reference
8426 and then Attribute_Name (Parent (N)) = Name_Address
8431 Make_Temporary_For_Slice;
8435 ------------------------------
8436 -- Expand_N_Type_Conversion --
8437 ------------------------------
8439 procedure Expand_N_Type_Conversion (N : Node_Id) is
8440 Loc : constant Source_Ptr := Sloc (N);
8441 Operand : constant Node_Id := Expression (N);
8442 Target_Type : constant Entity_Id := Etype (N);
8443 Operand_Type : Entity_Id := Etype (Operand);
8445 procedure Handle_Changed_Representation;
8446 -- This is called in the case of record and array type conversions to
8447 -- see if there is a change of representation to be handled. Change of
8448 -- representation is actually handled at the assignment statement level,
8449 -- and what this procedure does is rewrite node N conversion as an
8450 -- assignment to temporary. If there is no change of representation,
8451 -- then the conversion node is unchanged.
8453 procedure Raise_Accessibility_Error;
8454 -- Called when we know that an accessibility check will fail. Rewrites
8455 -- node N to an appropriate raise statement and outputs warning msgs.
8456 -- The Etype of the raise node is set to Target_Type.
8458 procedure Real_Range_Check;
8459 -- Handles generation of range check for real target value
8461 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean;
8462 -- True iff Present (Effective_Extra_Accessibility (Id)) successfully
8463 -- evaluates to True.
8465 -----------------------------------
8466 -- Handle_Changed_Representation --
8467 -----------------------------------
8469 procedure Handle_Changed_Representation is
8478 -- Nothing else to do if no change of representation
8480 if Same_Representation (Operand_Type, Target_Type) then
8483 -- The real change of representation work is done by the assignment
8484 -- statement processing. So if this type conversion is appearing as
8485 -- the expression of an assignment statement, nothing needs to be
8486 -- done to the conversion.
8488 elsif Nkind (Parent (N)) = N_Assignment_Statement then
8491 -- Otherwise we need to generate a temporary variable, and do the
8492 -- change of representation assignment into that temporary variable.
8493 -- The conversion is then replaced by a reference to this variable.
8498 -- If type is unconstrained we have to add a constraint, copied
8499 -- from the actual value of the left hand side.
8501 if not Is_Constrained (Target_Type) then
8502 if Has_Discriminants (Operand_Type) then
8503 Disc := First_Discriminant (Operand_Type);
8505 if Disc /= First_Stored_Discriminant (Operand_Type) then
8506 Disc := First_Stored_Discriminant (Operand_Type);
8510 while Present (Disc) loop
8512 Make_Selected_Component (Loc,
8514 Duplicate_Subexpr_Move_Checks (Operand),
8516 Make_Identifier (Loc, Chars (Disc))));
8517 Next_Discriminant (Disc);
8520 elsif Is_Array_Type (Operand_Type) then
8521 N_Ix := First_Index (Target_Type);
8524 for J in 1 .. Number_Dimensions (Operand_Type) loop
8526 -- We convert the bounds explicitly. We use an unchecked
8527 -- conversion because bounds checks are done elsewhere.
8532 Unchecked_Convert_To (Etype (N_Ix),
8533 Make_Attribute_Reference (Loc,
8535 Duplicate_Subexpr_No_Checks
8536 (Operand, Name_Req => True),
8537 Attribute_Name => Name_First,
8538 Expressions => New_List (
8539 Make_Integer_Literal (Loc, J)))),
8542 Unchecked_Convert_To (Etype (N_Ix),
8543 Make_Attribute_Reference (Loc,
8545 Duplicate_Subexpr_No_Checks
8546 (Operand, Name_Req => True),
8547 Attribute_Name => Name_Last,
8548 Expressions => New_List (
8549 Make_Integer_Literal (Loc, J))))));
8556 Odef := New_Occurrence_Of (Target_Type, Loc);
8558 if Present (Cons) then
8560 Make_Subtype_Indication (Loc,
8561 Subtype_Mark => Odef,
8563 Make_Index_Or_Discriminant_Constraint (Loc,
8564 Constraints => Cons));
8567 Temp := Make_Temporary (Loc, 'C');
8569 Make_Object_Declaration (Loc,
8570 Defining_Identifier => Temp,
8571 Object_Definition => Odef);
8573 Set_No_Initialization (Decl, True);
8575 -- Insert required actions. It is essential to suppress checks
8576 -- since we have suppressed default initialization, which means
8577 -- that the variable we create may have no discriminants.
8582 Make_Assignment_Statement (Loc,
8583 Name => New_Occurrence_Of (Temp, Loc),
8584 Expression => Relocate_Node (N))),
8585 Suppress => All_Checks);
8587 Rewrite (N, New_Occurrence_Of (Temp, Loc));
8590 end Handle_Changed_Representation;
8592 -------------------------------
8593 -- Raise_Accessibility_Error --
8594 -------------------------------
8596 procedure Raise_Accessibility_Error is
8599 Make_Raise_Program_Error (Sloc (N),
8600 Reason => PE_Accessibility_Check_Failed));
8601 Set_Etype (N, Target_Type);
8603 Error_Msg_N ("?accessibility check failure", N);
8605 ("\?& will be raised at run time", N, Standard_Program_Error);
8606 end Raise_Accessibility_Error;
8608 ----------------------
8609 -- Real_Range_Check --
8610 ----------------------
8612 -- Case of conversions to floating-point or fixed-point. If range checks
8613 -- are enabled and the target type has a range constraint, we convert:
8619 -- Tnn : typ'Base := typ'Base (x);
8620 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
8623 -- This is necessary when there is a conversion of integer to float or
8624 -- to fixed-point to ensure that the correct checks are made. It is not
8625 -- necessary for float to float where it is enough to simply set the
8626 -- Do_Range_Check flag.
8628 procedure Real_Range_Check is
8629 Btyp : constant Entity_Id := Base_Type (Target_Type);
8630 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
8631 Hi : constant Node_Id := Type_High_Bound (Target_Type);
8632 Xtyp : constant Entity_Id := Etype (Operand);
8637 -- Nothing to do if conversion was rewritten
8639 if Nkind (N) /= N_Type_Conversion then
8643 -- Nothing to do if range checks suppressed, or target has the same
8644 -- range as the base type (or is the base type).
8646 if Range_Checks_Suppressed (Target_Type)
8647 or else (Lo = Type_Low_Bound (Btyp)
8649 Hi = Type_High_Bound (Btyp))
8654 -- Nothing to do if expression is an entity on which checks have been
8657 if Is_Entity_Name (Operand)
8658 and then Range_Checks_Suppressed (Entity (Operand))
8663 -- Nothing to do if bounds are all static and we can tell that the
8664 -- expression is within the bounds of the target. Note that if the
8665 -- operand is of an unconstrained floating-point type, then we do
8666 -- not trust it to be in range (might be infinite)
8669 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
8670 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
8673 if (not Is_Floating_Point_Type (Xtyp)
8674 or else Is_Constrained (Xtyp))
8675 and then Compile_Time_Known_Value (S_Lo)
8676 and then Compile_Time_Known_Value (S_Hi)
8677 and then Compile_Time_Known_Value (Hi)
8678 and then Compile_Time_Known_Value (Lo)
8681 D_Lov : constant Ureal := Expr_Value_R (Lo);
8682 D_Hiv : constant Ureal := Expr_Value_R (Hi);
8687 if Is_Real_Type (Xtyp) then
8688 S_Lov := Expr_Value_R (S_Lo);
8689 S_Hiv := Expr_Value_R (S_Hi);
8691 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
8692 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
8696 and then S_Lov >= D_Lov
8697 and then S_Hiv <= D_Hiv
8699 Set_Do_Range_Check (Operand, False);
8706 -- For float to float conversions, we are done
8708 if Is_Floating_Point_Type (Xtyp)
8710 Is_Floating_Point_Type (Btyp)
8715 -- Otherwise rewrite the conversion as described above
8717 Conv := Relocate_Node (N);
8718 Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
8719 Set_Etype (Conv, Btyp);
8721 -- Enable overflow except for case of integer to float conversions,
8722 -- where it is never required, since we can never have overflow in
8725 if not Is_Integer_Type (Etype (Operand)) then
8726 Enable_Overflow_Check (Conv);
8729 Tnn := Make_Temporary (Loc, 'T', Conv);
8731 Insert_Actions (N, New_List (
8732 Make_Object_Declaration (Loc,
8733 Defining_Identifier => Tnn,
8734 Object_Definition => New_Occurrence_Of (Btyp, Loc),
8735 Constant_Present => True,
8736 Expression => Conv),
8738 Make_Raise_Constraint_Error (Loc,
8743 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8745 Make_Attribute_Reference (Loc,
8746 Attribute_Name => Name_First,
8748 New_Occurrence_Of (Target_Type, Loc))),
8752 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8754 Make_Attribute_Reference (Loc,
8755 Attribute_Name => Name_Last,
8757 New_Occurrence_Of (Target_Type, Loc)))),
8758 Reason => CE_Range_Check_Failed)));
8760 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
8761 Analyze_And_Resolve (N, Btyp);
8762 end Real_Range_Check;
8764 -----------------------------
8765 -- Has_Extra_Accessibility --
8766 -----------------------------
8768 -- Returns true for a formal of an anonymous access type or for
8769 -- an Ada 2012-style stand-alone object of an anonymous access type.
8771 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean is
8773 if Is_Formal (Id) or else Ekind_In (Id, E_Constant, E_Variable) then
8774 return Present (Effective_Extra_Accessibility (Id));
8778 end Has_Extra_Accessibility;
8780 -- Start of processing for Expand_N_Type_Conversion
8783 -- Nothing at all to do if conversion is to the identical type so remove
8784 -- the conversion completely, it is useless, except that it may carry
8785 -- an Assignment_OK attribute, which must be propagated to the operand.
8787 if Operand_Type = Target_Type then
8788 if Assignment_OK (N) then
8789 Set_Assignment_OK (Operand);
8792 Rewrite (N, Relocate_Node (Operand));
8796 -- Nothing to do if this is the second argument of read. This is a
8797 -- "backwards" conversion that will be handled by the specialized code
8798 -- in attribute processing.
8800 if Nkind (Parent (N)) = N_Attribute_Reference
8801 and then Attribute_Name (Parent (N)) = Name_Read
8802 and then Next (First (Expressions (Parent (N)))) = N
8807 -- Check for case of converting to a type that has an invariant
8808 -- associated with it. This required an invariant check. We convert
8814 -- do invariant_check (typ (expr)) in typ (expr);
8816 -- using Duplicate_Subexpr to avoid multiple side effects
8818 -- Note: the Comes_From_Source check, and then the resetting of this
8819 -- flag prevents what would otherwise be an infinite recursion.
8821 if Has_Invariants (Target_Type)
8822 and then Present (Invariant_Procedure (Target_Type))
8823 and then Comes_From_Source (N)
8825 Set_Comes_From_Source (N, False);
8827 Make_Expression_With_Actions (Loc,
8828 Actions => New_List (
8829 Make_Invariant_Call (Duplicate_Subexpr (N))),
8830 Expression => Duplicate_Subexpr_No_Checks (N)));
8831 Analyze_And_Resolve (N, Target_Type);
8835 -- Here if we may need to expand conversion
8837 -- If the operand of the type conversion is an arithmetic operation on
8838 -- signed integers, and the based type of the signed integer type in
8839 -- question is smaller than Standard.Integer, we promote both of the
8840 -- operands to type Integer.
8842 -- For example, if we have
8844 -- target-type (opnd1 + opnd2)
8846 -- and opnd1 and opnd2 are of type short integer, then we rewrite
8849 -- target-type (integer(opnd1) + integer(opnd2))
8851 -- We do this because we are always allowed to compute in a larger type
8852 -- if we do the right thing with the result, and in this case we are
8853 -- going to do a conversion which will do an appropriate check to make
8854 -- sure that things are in range of the target type in any case. This
8855 -- avoids some unnecessary intermediate overflows.
8857 -- We might consider a similar transformation in the case where the
8858 -- target is a real type or a 64-bit integer type, and the operand
8859 -- is an arithmetic operation using a 32-bit integer type. However,
8860 -- we do not bother with this case, because it could cause significant
8861 -- inefficiencies on 32-bit machines. On a 64-bit machine it would be
8862 -- much cheaper, but we don't want different behavior on 32-bit and
8863 -- 64-bit machines. Note that the exclusion of the 64-bit case also
8864 -- handles the configurable run-time cases where 64-bit arithmetic
8865 -- may simply be unavailable.
8867 -- Note: this circuit is partially redundant with respect to the circuit
8868 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
8869 -- the processing here. Also we still need the Checks circuit, since we
8870 -- have to be sure not to generate junk overflow checks in the first
8871 -- place, since it would be trick to remove them here!
8873 if Integer_Promotion_Possible (N) then
8875 -- All conditions met, go ahead with transformation
8883 Make_Type_Conversion (Loc,
8884 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8885 Expression => Relocate_Node (Right_Opnd (Operand)));
8887 Opnd := New_Op_Node (Nkind (Operand), Loc);
8888 Set_Right_Opnd (Opnd, R);
8890 if Nkind (Operand) in N_Binary_Op then
8892 Make_Type_Conversion (Loc,
8893 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8894 Expression => Relocate_Node (Left_Opnd (Operand)));
8896 Set_Left_Opnd (Opnd, L);
8900 Make_Type_Conversion (Loc,
8901 Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
8902 Expression => Opnd));
8904 Analyze_And_Resolve (N, Target_Type);
8909 -- Do validity check if validity checking operands
8911 if Validity_Checks_On
8912 and then Validity_Check_Operands
8914 Ensure_Valid (Operand);
8917 -- Special case of converting from non-standard boolean type
8919 if Is_Boolean_Type (Operand_Type)
8920 and then (Nonzero_Is_True (Operand_Type))
8922 Adjust_Condition (Operand);
8923 Set_Etype (Operand, Standard_Boolean);
8924 Operand_Type := Standard_Boolean;
8927 -- Case of converting to an access type
8929 if Is_Access_Type (Target_Type) then
8931 -- Apply an accessibility check when the conversion operand is an
8932 -- access parameter (or a renaming thereof), unless conversion was
8933 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
8934 -- Note that other checks may still need to be applied below (such
8935 -- as tagged type checks).
8937 if Is_Entity_Name (Operand)
8938 and then Has_Extra_Accessibility (Entity (Operand))
8939 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
8940 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
8941 or else Attribute_Name (Original_Node (N)) = Name_Access)
8943 Apply_Accessibility_Check
8944 (Operand, Target_Type, Insert_Node => Operand);
8946 -- If the level of the operand type is statically deeper than the
8947 -- level of the target type, then force Program_Error. Note that this
8948 -- can only occur for cases where the attribute is within the body of
8949 -- an instantiation (otherwise the conversion will already have been
8950 -- rejected as illegal). Note: warnings are issued by the analyzer
8951 -- for the instance cases.
8953 elsif In_Instance_Body
8954 and then Type_Access_Level (Operand_Type) >
8955 Type_Access_Level (Target_Type)
8957 Raise_Accessibility_Error;
8959 -- When the operand is a selected access discriminant the check needs
8960 -- to be made against the level of the object denoted by the prefix
8961 -- of the selected name. Force Program_Error for this case as well
8962 -- (this accessibility violation can only happen if within the body
8963 -- of an instantiation).
8965 elsif In_Instance_Body
8966 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
8967 and then Nkind (Operand) = N_Selected_Component
8968 and then Object_Access_Level (Operand) >
8969 Type_Access_Level (Target_Type)
8971 Raise_Accessibility_Error;
8976 -- Case of conversions of tagged types and access to tagged types
8978 -- When needed, that is to say when the expression is class-wide, Add
8979 -- runtime a tag check for (strict) downward conversion by using the
8980 -- membership test, generating:
8982 -- [constraint_error when Operand not in Target_Type'Class]
8984 -- or in the access type case
8986 -- [constraint_error
8987 -- when Operand /= null
8988 -- and then Operand.all not in
8989 -- Designated_Type (Target_Type)'Class]
8991 if (Is_Access_Type (Target_Type)
8992 and then Is_Tagged_Type (Designated_Type (Target_Type)))
8993 or else Is_Tagged_Type (Target_Type)
8995 -- Do not do any expansion in the access type case if the parent is a
8996 -- renaming, since this is an error situation which will be caught by
8997 -- Sem_Ch8, and the expansion can interfere with this error check.
8999 if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
9003 -- Otherwise, proceed with processing tagged conversion
9005 Tagged_Conversion : declare
9006 Actual_Op_Typ : Entity_Id;
9007 Actual_Targ_Typ : Entity_Id;
9008 Make_Conversion : Boolean := False;
9009 Root_Op_Typ : Entity_Id;
9011 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
9012 -- Create a membership check to test whether Operand is a member
9013 -- of Targ_Typ. If the original Target_Type is an access, include
9014 -- a test for null value. The check is inserted at N.
9016 --------------------
9017 -- Make_Tag_Check --
9018 --------------------
9020 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
9025 -- [Constraint_Error
9026 -- when Operand /= null
9027 -- and then Operand.all not in Targ_Typ]
9029 if Is_Access_Type (Target_Type) then
9034 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
9035 Right_Opnd => Make_Null (Loc)),
9040 Make_Explicit_Dereference (Loc,
9041 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
9042 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
9045 -- [Constraint_Error when Operand not in Targ_Typ]
9050 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
9051 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
9055 Make_Raise_Constraint_Error (Loc,
9057 Reason => CE_Tag_Check_Failed));
9060 -- Start of processing for Tagged_Conversion
9063 -- Handle entities from the limited view
9065 if Is_Access_Type (Operand_Type) then
9067 Available_View (Designated_Type (Operand_Type));
9069 Actual_Op_Typ := Operand_Type;
9072 if Is_Access_Type (Target_Type) then
9074 Available_View (Designated_Type (Target_Type));
9076 Actual_Targ_Typ := Target_Type;
9079 Root_Op_Typ := Root_Type (Actual_Op_Typ);
9081 -- Ada 2005 (AI-251): Handle interface type conversion
9083 if Is_Interface (Actual_Op_Typ) then
9084 Expand_Interface_Conversion (N, Is_Static => False);
9088 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
9090 -- Create a runtime tag check for a downward class-wide type
9093 if Is_Class_Wide_Type (Actual_Op_Typ)
9094 and then Actual_Op_Typ /= Actual_Targ_Typ
9095 and then Root_Op_Typ /= Actual_Targ_Typ
9096 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ,
9097 Use_Full_View => True)
9099 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
9100 Make_Conversion := True;
9103 -- AI05-0073: If the result subtype of the function is defined
9104 -- by an access_definition designating a specific tagged type
9105 -- T, a check is made that the result value is null or the tag
9106 -- of the object designated by the result value identifies T.
9107 -- Constraint_Error is raised if this check fails.
9109 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
9112 Func_Typ : Entity_Id;
9115 -- Climb scope stack looking for the enclosing function
9117 Func := Current_Scope;
9118 while Present (Func)
9119 and then Ekind (Func) /= E_Function
9121 Func := Scope (Func);
9124 -- The function's return subtype must be defined using
9125 -- an access definition.
9127 if Nkind (Result_Definition (Parent (Func))) =
9130 Func_Typ := Directly_Designated_Type (Etype (Func));
9132 -- The return subtype denotes a specific tagged type,
9133 -- in other words, a non class-wide type.
9135 if Is_Tagged_Type (Func_Typ)
9136 and then not Is_Class_Wide_Type (Func_Typ)
9138 Make_Tag_Check (Actual_Targ_Typ);
9139 Make_Conversion := True;
9145 -- We have generated a tag check for either a class-wide type
9146 -- conversion or for AI05-0073.
9148 if Make_Conversion then
9153 Make_Unchecked_Type_Conversion (Loc,
9154 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
9155 Expression => Relocate_Node (Expression (N)));
9157 Analyze_And_Resolve (N, Target_Type);
9161 end Tagged_Conversion;
9163 -- Case of other access type conversions
9165 elsif Is_Access_Type (Target_Type) then
9166 Apply_Constraint_Check (Operand, Target_Type);
9168 -- Case of conversions from a fixed-point type
9170 -- These conversions require special expansion and processing, found in
9171 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
9172 -- since from a semantic point of view, these are simple integer
9173 -- conversions, which do not need further processing.
9175 elsif Is_Fixed_Point_Type (Operand_Type)
9176 and then not Conversion_OK (N)
9178 -- We should never see universal fixed at this case, since the
9179 -- expansion of the constituent divide or multiply should have
9180 -- eliminated the explicit mention of universal fixed.
9182 pragma Assert (Operand_Type /= Universal_Fixed);
9184 -- Check for special case of the conversion to universal real that
9185 -- occurs as a result of the use of a round attribute. In this case,
9186 -- the real type for the conversion is taken from the target type of
9187 -- the Round attribute and the result must be marked as rounded.
9189 if Target_Type = Universal_Real
9190 and then Nkind (Parent (N)) = N_Attribute_Reference
9191 and then Attribute_Name (Parent (N)) = Name_Round
9193 Set_Rounded_Result (N);
9194 Set_Etype (N, Etype (Parent (N)));
9197 -- Otherwise do correct fixed-conversion, but skip these if the
9198 -- Conversion_OK flag is set, because from a semantic point of view
9199 -- these are simple integer conversions needing no further processing
9200 -- (the backend will simply treat them as integers).
9202 if not Conversion_OK (N) then
9203 if Is_Fixed_Point_Type (Etype (N)) then
9204 Expand_Convert_Fixed_To_Fixed (N);
9207 elsif Is_Integer_Type (Etype (N)) then
9208 Expand_Convert_Fixed_To_Integer (N);
9211 pragma Assert (Is_Floating_Point_Type (Etype (N)));
9212 Expand_Convert_Fixed_To_Float (N);
9217 -- Case of conversions to a fixed-point type
9219 -- These conversions require special expansion and processing, found in
9220 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
9221 -- since from a semantic point of view, these are simple integer
9222 -- conversions, which do not need further processing.
9224 elsif Is_Fixed_Point_Type (Target_Type)
9225 and then not Conversion_OK (N)
9227 if Is_Integer_Type (Operand_Type) then
9228 Expand_Convert_Integer_To_Fixed (N);
9231 pragma Assert (Is_Floating_Point_Type (Operand_Type));
9232 Expand_Convert_Float_To_Fixed (N);
9236 -- Case of float-to-integer conversions
9238 -- We also handle float-to-fixed conversions with Conversion_OK set
9239 -- since semantically the fixed-point target is treated as though it
9240 -- were an integer in such cases.
9242 elsif Is_Floating_Point_Type (Operand_Type)
9244 (Is_Integer_Type (Target_Type)
9246 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
9248 -- One more check here, gcc is still not able to do conversions of
9249 -- this type with proper overflow checking, and so gigi is doing an
9250 -- approximation of what is required by doing floating-point compares
9251 -- with the end-point. But that can lose precision in some cases, and
9252 -- give a wrong result. Converting the operand to Universal_Real is
9253 -- helpful, but still does not catch all cases with 64-bit integers
9254 -- on targets with only 64-bit floats.
9256 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
9257 -- Can this code be removed ???
9259 if Do_Range_Check (Operand) then
9261 Make_Type_Conversion (Loc,
9263 New_Occurrence_Of (Universal_Real, Loc),
9265 Relocate_Node (Operand)));
9267 Set_Etype (Operand, Universal_Real);
9268 Enable_Range_Check (Operand);
9269 Set_Do_Range_Check (Expression (Operand), False);
9272 -- Case of array conversions
9274 -- Expansion of array conversions, add required length/range checks but
9275 -- only do this if there is no change of representation. For handling of
9276 -- this case, see Handle_Changed_Representation.
9278 elsif Is_Array_Type (Target_Type) then
9279 if Is_Constrained (Target_Type) then
9280 Apply_Length_Check (Operand, Target_Type);
9282 Apply_Range_Check (Operand, Target_Type);
9285 Handle_Changed_Representation;
9287 -- Case of conversions of discriminated types
9289 -- Add required discriminant checks if target is constrained. Again this
9290 -- change is skipped if we have a change of representation.
9292 elsif Has_Discriminants (Target_Type)
9293 and then Is_Constrained (Target_Type)
9295 Apply_Discriminant_Check (Operand, Target_Type);
9296 Handle_Changed_Representation;
9298 -- Case of all other record conversions. The only processing required
9299 -- is to check for a change of representation requiring the special
9300 -- assignment processing.
9302 elsif Is_Record_Type (Target_Type) then
9304 -- Ada 2005 (AI-216): Program_Error is raised when converting from
9305 -- a derived Unchecked_Union type to an unconstrained type that is
9306 -- not Unchecked_Union if the operand lacks inferable discriminants.
9308 if Is_Derived_Type (Operand_Type)
9309 and then Is_Unchecked_Union (Base_Type (Operand_Type))
9310 and then not Is_Constrained (Target_Type)
9311 and then not Is_Unchecked_Union (Base_Type (Target_Type))
9312 and then not Has_Inferable_Discriminants (Operand)
9314 -- To prevent Gigi from generating illegal code, we generate a
9315 -- Program_Error node, but we give it the target type of the
9319 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
9320 Reason => PE_Unchecked_Union_Restriction);
9323 Set_Etype (PE, Target_Type);
9328 Handle_Changed_Representation;
9331 -- Case of conversions of enumeration types
9333 elsif Is_Enumeration_Type (Target_Type) then
9335 -- Special processing is required if there is a change of
9336 -- representation (from enumeration representation clauses).
9338 if not Same_Representation (Target_Type, Operand_Type) then
9340 -- Convert: x(y) to x'val (ytyp'val (y))
9343 Make_Attribute_Reference (Loc,
9344 Prefix => New_Occurrence_Of (Target_Type, Loc),
9345 Attribute_Name => Name_Val,
9346 Expressions => New_List (
9347 Make_Attribute_Reference (Loc,
9348 Prefix => New_Occurrence_Of (Operand_Type, Loc),
9349 Attribute_Name => Name_Pos,
9350 Expressions => New_List (Operand)))));
9352 Analyze_And_Resolve (N, Target_Type);
9355 -- Case of conversions to floating-point
9357 elsif Is_Floating_Point_Type (Target_Type) then
9361 -- At this stage, either the conversion node has been transformed into
9362 -- some other equivalent expression, or left as a conversion that can be
9363 -- handled by Gigi, in the following cases:
9365 -- Conversions with no change of representation or type
9367 -- Numeric conversions involving integer, floating- and fixed-point
9368 -- values. Fixed-point values are allowed only if Conversion_OK is
9369 -- set, i.e. if the fixed-point values are to be treated as integers.
9371 -- No other conversions should be passed to Gigi
9373 -- Check: are these rules stated in sinfo??? if so, why restate here???
9375 -- The only remaining step is to generate a range check if we still have
9376 -- a type conversion at this stage and Do_Range_Check is set. For now we
9377 -- do this only for conversions of discrete types.
9379 if Nkind (N) = N_Type_Conversion
9380 and then Is_Discrete_Type (Etype (N))
9383 Expr : constant Node_Id := Expression (N);
9388 if Do_Range_Check (Expr)
9389 and then Is_Discrete_Type (Etype (Expr))
9391 Set_Do_Range_Check (Expr, False);
9393 -- Before we do a range check, we have to deal with treating a
9394 -- fixed-point operand as an integer. The way we do this is
9395 -- simply to do an unchecked conversion to an appropriate
9396 -- integer type large enough to hold the result.
9398 -- This code is not active yet, because we are only dealing
9399 -- with discrete types so far ???
9401 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
9402 and then Treat_Fixed_As_Integer (Expr)
9404 Ftyp := Base_Type (Etype (Expr));
9406 if Esize (Ftyp) >= Esize (Standard_Integer) then
9407 Ityp := Standard_Long_Long_Integer;
9409 Ityp := Standard_Integer;
9412 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
9415 -- Reset overflow flag, since the range check will include
9416 -- dealing with possible overflow, and generate the check. If
9417 -- Address is either a source type or target type, suppress
9418 -- range check to avoid typing anomalies when it is a visible
9421 Set_Do_Overflow_Check (N, False);
9422 if not Is_Descendent_Of_Address (Etype (Expr))
9423 and then not Is_Descendent_Of_Address (Target_Type)
9425 Generate_Range_Check
9426 (Expr, Target_Type, CE_Range_Check_Failed);
9432 -- Final step, if the result is a type conversion involving Vax_Float
9433 -- types, then it is subject for further special processing.
9435 if Nkind (N) = N_Type_Conversion
9436 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
9438 Expand_Vax_Conversion (N);
9442 -- Here at end of processing
9445 -- Apply predicate check if required. Note that we can't just call
9446 -- Apply_Predicate_Check here, because the type looks right after
9447 -- the conversion and it would omit the check. The Comes_From_Source
9448 -- guard is necessary to prevent infinite recursions when we generate
9449 -- internal conversions for the purpose of checking predicates.
9451 if Present (Predicate_Function (Target_Type))
9452 and then Target_Type /= Operand_Type
9453 and then Comes_From_Source (N)
9456 New_Expr : constant Node_Id := Duplicate_Subexpr (N);
9459 -- Avoid infinite recursion on the subsequent expansion of
9460 -- of the copy of the original type conversion.
9462 Set_Comes_From_Source (New_Expr, False);
9463 Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr));
9466 end Expand_N_Type_Conversion;
9468 -----------------------------------
9469 -- Expand_N_Unchecked_Expression --
9470 -----------------------------------
9472 -- Remove the unchecked expression node from the tree. Its job was simply
9473 -- to make sure that its constituent expression was handled with checks
9474 -- off, and now that that is done, we can remove it from the tree, and
9475 -- indeed must, since Gigi does not expect to see these nodes.
9477 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
9478 Exp : constant Node_Id := Expression (N);
9480 Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
9482 end Expand_N_Unchecked_Expression;
9484 ----------------------------------------
9485 -- Expand_N_Unchecked_Type_Conversion --
9486 ----------------------------------------
9488 -- If this cannot be handled by Gigi and we haven't already made a
9489 -- temporary for it, do it now.
9491 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
9492 Target_Type : constant Entity_Id := Etype (N);
9493 Operand : constant Node_Id := Expression (N);
9494 Operand_Type : constant Entity_Id := Etype (Operand);
9497 -- Nothing at all to do if conversion is to the identical type so remove
9498 -- the conversion completely, it is useless, except that it may carry
9499 -- an Assignment_OK indication which must be propagated to the operand.
9501 if Operand_Type = Target_Type then
9503 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
9505 if Assignment_OK (N) then
9506 Set_Assignment_OK (Operand);
9509 Rewrite (N, Relocate_Node (Operand));
9513 -- If we have a conversion of a compile time known value to a target
9514 -- type and the value is in range of the target type, then we can simply
9515 -- replace the construct by an integer literal of the correct type. We
9516 -- only apply this to integer types being converted. Possibly it may
9517 -- apply in other cases, but it is too much trouble to worry about.
9519 -- Note that we do not do this transformation if the Kill_Range_Check
9520 -- flag is set, since then the value may be outside the expected range.
9521 -- This happens in the Normalize_Scalars case.
9523 -- We also skip this if either the target or operand type is biased
9524 -- because in this case, the unchecked conversion is supposed to
9525 -- preserve the bit pattern, not the integer value.
9527 if Is_Integer_Type (Target_Type)
9528 and then not Has_Biased_Representation (Target_Type)
9529 and then Is_Integer_Type (Operand_Type)
9530 and then not Has_Biased_Representation (Operand_Type)
9531 and then Compile_Time_Known_Value (Operand)
9532 and then not Kill_Range_Check (N)
9535 Val : constant Uint := Expr_Value (Operand);
9538 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
9540 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
9542 Val >= Expr_Value (Type_Low_Bound (Target_Type))
9544 Val <= Expr_Value (Type_High_Bound (Target_Type))
9546 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
9548 -- If Address is the target type, just set the type to avoid a
9549 -- spurious type error on the literal when Address is a visible
9552 if Is_Descendent_Of_Address (Target_Type) then
9553 Set_Etype (N, Target_Type);
9555 Analyze_And_Resolve (N, Target_Type);
9563 -- Nothing to do if conversion is safe
9565 if Safe_Unchecked_Type_Conversion (N) then
9569 -- Otherwise force evaluation unless Assignment_OK flag is set (this
9570 -- flag indicates ??? -- more comments needed here)
9572 if Assignment_OK (N) then
9575 Force_Evaluation (N);
9577 end Expand_N_Unchecked_Type_Conversion;
9579 ----------------------------
9580 -- Expand_Record_Equality --
9581 ----------------------------
9583 -- For non-variant records, Equality is expanded when needed into:
9585 -- and then Lhs.Discr1 = Rhs.Discr1
9587 -- and then Lhs.Discrn = Rhs.Discrn
9588 -- and then Lhs.Cmp1 = Rhs.Cmp1
9590 -- and then Lhs.Cmpn = Rhs.Cmpn
9592 -- The expression is folded by the back-end for adjacent fields. This
9593 -- function is called for tagged record in only one occasion: for imple-
9594 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
9595 -- otherwise the primitive "=" is used directly.
9597 function Expand_Record_Equality
9602 Bodies : List_Id) return Node_Id
9604 Loc : constant Source_Ptr := Sloc (Nod);
9609 First_Time : Boolean := True;
9611 function Suitable_Element (C : Entity_Id) return Entity_Id;
9612 -- Return the first field to compare beginning with C, skipping the
9613 -- inherited components.
9615 ----------------------
9616 -- Suitable_Element --
9617 ----------------------
9619 function Suitable_Element (C : Entity_Id) return Entity_Id is
9624 elsif Ekind (C) /= E_Discriminant
9625 and then Ekind (C) /= E_Component
9627 return Suitable_Element (Next_Entity (C));
9629 elsif Is_Tagged_Type (Typ)
9630 and then C /= Original_Record_Component (C)
9632 return Suitable_Element (Next_Entity (C));
9634 elsif Chars (C) = Name_uTag then
9635 return Suitable_Element (Next_Entity (C));
9637 -- The .NET/JVM version of type Root_Controlled contains two fields
9638 -- which should not be considered part of the object. To achieve
9639 -- proper equiality between two controlled objects on .NET/JVM, skip
9640 -- field _parent whenever it is of type Root_Controlled.
9642 elsif Chars (C) = Name_uParent
9643 and then VM_Target /= No_VM
9644 and then Etype (C) = RTE (RE_Root_Controlled)
9646 return Suitable_Element (Next_Entity (C));
9648 elsif Is_Interface (Etype (C)) then
9649 return Suitable_Element (Next_Entity (C));
9654 end Suitable_Element;
9656 -- Start of processing for Expand_Record_Equality
9659 -- Generates the following code: (assuming that Typ has one Discr and
9660 -- component C2 is also a record)
9663 -- and then Lhs.Discr1 = Rhs.Discr1
9664 -- and then Lhs.C1 = Rhs.C1
9665 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
9667 -- and then Lhs.Cmpn = Rhs.Cmpn
9669 Result := New_Reference_To (Standard_True, Loc);
9670 C := Suitable_Element (First_Entity (Typ));
9671 while Present (C) loop
9679 First_Time := False;
9683 New_Lhs := New_Copy_Tree (Lhs);
9684 New_Rhs := New_Copy_Tree (Rhs);
9688 Expand_Composite_Equality (Nod, Etype (C),
9690 Make_Selected_Component (Loc,
9692 Selector_Name => New_Reference_To (C, Loc)),
9694 Make_Selected_Component (Loc,
9696 Selector_Name => New_Reference_To (C, Loc)),
9699 -- If some (sub)component is an unchecked_union, the whole
9700 -- operation will raise program error.
9702 if Nkind (Check) = N_Raise_Program_Error then
9704 Set_Etype (Result, Standard_Boolean);
9709 Left_Opnd => Result,
9710 Right_Opnd => Check);
9714 C := Suitable_Element (Next_Entity (C));
9718 end Expand_Record_Equality;
9720 -----------------------------------
9721 -- Expand_Short_Circuit_Operator --
9722 -----------------------------------
9724 -- Deal with special expansion if actions are present for the right operand
9725 -- and deal with optimizing case of arguments being True or False. We also
9726 -- deal with the special case of non-standard boolean values.
9728 procedure Expand_Short_Circuit_Operator (N : Node_Id) is
9729 Loc : constant Source_Ptr := Sloc (N);
9730 Typ : constant Entity_Id := Etype (N);
9731 Left : constant Node_Id := Left_Opnd (N);
9732 Right : constant Node_Id := Right_Opnd (N);
9733 LocR : constant Source_Ptr := Sloc (Right);
9736 Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
9737 Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
9738 -- If Left = Shortcut_Value then Right need not be evaluated
9740 function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
9741 -- For Opnd a boolean expression, return a Boolean expression equivalent
9742 -- to Opnd /= Shortcut_Value.
9744 --------------------
9745 -- Make_Test_Expr --
9746 --------------------
9748 function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
9750 if Shortcut_Value then
9751 return Make_Op_Not (Sloc (Opnd), Opnd);
9758 -- Entity for a temporary variable holding the value of the operator,
9759 -- used for expansion in the case where actions are present.
9761 -- Start of processing for Expand_Short_Circuit_Operator
9764 -- Deal with non-standard booleans
9766 if Is_Boolean_Type (Typ) then
9767 Adjust_Condition (Left);
9768 Adjust_Condition (Right);
9769 Set_Etype (N, Standard_Boolean);
9772 -- Check for cases where left argument is known to be True or False
9774 if Compile_Time_Known_Value (Left) then
9776 -- Mark SCO for left condition as compile time known
9778 if Generate_SCO and then Comes_From_Source (Left) then
9779 Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
9782 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
9783 -- Any actions associated with Right will be executed unconditionally
9784 -- and can thus be inserted into the tree unconditionally.
9786 if Expr_Value_E (Left) /= Shortcut_Ent then
9787 if Present (Actions (N)) then
9788 Insert_Actions (N, Actions (N));
9793 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
9794 -- In this case we can forget the actions associated with Right,
9795 -- since they will never be executed.
9798 Kill_Dead_Code (Right);
9799 Kill_Dead_Code (Actions (N));
9800 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9803 Adjust_Result_Type (N, Typ);
9807 -- If Actions are present for the right operand, we have to do some
9808 -- special processing. We can't just let these actions filter back into
9809 -- code preceding the short circuit (which is what would have happened
9810 -- if we had not trapped them in the short-circuit form), since they
9811 -- must only be executed if the right operand of the short circuit is
9812 -- executed and not otherwise.
9814 -- the temporary variable C.
9816 if Present (Actions (N)) then
9817 Actlist := Actions (N);
9819 -- The old approach is to expand:
9821 -- left AND THEN right
9825 -- C : Boolean := False;
9833 -- and finally rewrite the operator into a reference to C. Similarly
9834 -- for left OR ELSE right, with negated values. Note that this
9835 -- rewrite causes some difficulties for coverage analysis because
9836 -- of the introduction of the new variable C, which obscures the
9837 -- structure of the test.
9839 -- We use this "old approach" if use of N_Expression_With_Actions
9840 -- is False (see description in Opt of when this is or is not set).
9842 if not Use_Expression_With_Actions then
9843 Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
9846 Make_Object_Declaration (Loc,
9847 Defining_Identifier =>
9849 Object_Definition =>
9850 New_Occurrence_Of (Standard_Boolean, Loc),
9852 New_Occurrence_Of (Shortcut_Ent, Loc)));
9855 Make_Implicit_If_Statement (Right,
9856 Condition => Make_Test_Expr (Right),
9857 Then_Statements => New_List (
9858 Make_Assignment_Statement (LocR,
9859 Name => New_Occurrence_Of (Op_Var, LocR),
9862 (Boolean_Literals (not Shortcut_Value), LocR)))));
9865 Make_Implicit_If_Statement (Left,
9866 Condition => Make_Test_Expr (Left),
9867 Then_Statements => Actlist));
9869 Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
9870 Analyze_And_Resolve (N, Standard_Boolean);
9872 -- The new approach, activated for now by the use of debug flag
9873 -- -gnatd.X is to use the new Expression_With_Actions node for the
9874 -- right operand of the short-circuit form. This should solve the
9875 -- traceability problems for coverage analysis.
9879 Make_Expression_With_Actions (LocR,
9880 Expression => Relocate_Node (Right),
9881 Actions => Actlist));
9882 Set_Actions (N, No_List);
9883 Analyze_And_Resolve (Right, Standard_Boolean);
9886 Adjust_Result_Type (N, Typ);
9890 -- No actions present, check for cases of right argument True/False
9892 if Compile_Time_Known_Value (Right) then
9894 -- Mark SCO for left condition as compile time known
9896 if Generate_SCO and then Comes_From_Source (Right) then
9897 Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
9900 -- Change (Left and then True), (Left or else False) to Left.
9901 -- Note that we know there are no actions associated with the right
9902 -- operand, since we just checked for this case above.
9904 if Expr_Value_E (Right) /= Shortcut_Ent then
9907 -- Change (Left and then False), (Left or else True) to Right,
9908 -- making sure to preserve any side effects associated with the Left
9912 Remove_Side_Effects (Left);
9913 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9917 Adjust_Result_Type (N, Typ);
9918 end Expand_Short_Circuit_Operator;
9920 -------------------------------------
9921 -- Fixup_Universal_Fixed_Operation --
9922 -------------------------------------
9924 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
9925 Conv : constant Node_Id := Parent (N);
9928 -- We must have a type conversion immediately above us
9930 pragma Assert (Nkind (Conv) = N_Type_Conversion);
9932 -- Normally the type conversion gives our target type. The exception
9933 -- occurs in the case of the Round attribute, where the conversion
9934 -- will be to universal real, and our real type comes from the Round
9935 -- attribute (as well as an indication that we must round the result)
9937 if Nkind (Parent (Conv)) = N_Attribute_Reference
9938 and then Attribute_Name (Parent (Conv)) = Name_Round
9940 Set_Etype (N, Etype (Parent (Conv)));
9941 Set_Rounded_Result (N);
9943 -- Normal case where type comes from conversion above us
9946 Set_Etype (N, Etype (Conv));
9948 end Fixup_Universal_Fixed_Operation;
9950 ---------------------------------
9951 -- Has_Inferable_Discriminants --
9952 ---------------------------------
9954 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
9956 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
9957 -- Determines whether the left-most prefix of a selected component is a
9958 -- formal parameter in a subprogram. Assumes N is a selected component.
9960 --------------------------------
9961 -- Prefix_Is_Formal_Parameter --
9962 --------------------------------
9964 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
9965 Sel_Comp : Node_Id := N;
9968 -- Move to the left-most prefix by climbing up the tree
9970 while Present (Parent (Sel_Comp))
9971 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
9973 Sel_Comp := Parent (Sel_Comp);
9976 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
9977 end Prefix_Is_Formal_Parameter;
9979 -- Start of processing for Has_Inferable_Discriminants
9982 -- For identifiers and indexed components, it is sufficient to have a
9983 -- constrained Unchecked_Union nominal subtype.
9985 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
9986 return Is_Unchecked_Union (Base_Type (Etype (N)))
9988 Is_Constrained (Etype (N));
9990 -- For selected components, the subtype of the selector must be a
9991 -- constrained Unchecked_Union. If the component is subject to a
9992 -- per-object constraint, then the enclosing object must have inferable
9995 elsif Nkind (N) = N_Selected_Component then
9996 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
9998 -- A small hack. If we have a per-object constrained selected
9999 -- component of a formal parameter, return True since we do not
10000 -- know the actual parameter association yet.
10002 if Prefix_Is_Formal_Parameter (N) then
10006 -- Otherwise, check the enclosing object and the selector
10008 return Has_Inferable_Discriminants (Prefix (N))
10010 Has_Inferable_Discriminants (Selector_Name (N));
10013 -- The call to Has_Inferable_Discriminants will determine whether
10014 -- the selector has a constrained Unchecked_Union nominal type.
10016 return Has_Inferable_Discriminants (Selector_Name (N));
10018 -- A qualified expression has inferable discriminants if its subtype
10019 -- mark is a constrained Unchecked_Union subtype.
10021 elsif Nkind (N) = N_Qualified_Expression then
10022 return Is_Unchecked_Union (Subtype_Mark (N))
10024 Is_Constrained (Subtype_Mark (N));
10029 end Has_Inferable_Discriminants;
10031 -------------------------------
10032 -- Insert_Dereference_Action --
10033 -------------------------------
10035 procedure Insert_Dereference_Action (N : Node_Id) is
10036 Loc : constant Source_Ptr := Sloc (N);
10037 Typ : constant Entity_Id := Etype (N);
10038 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
10039 Pnod : constant Node_Id := Parent (N);
10041 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
10042 -- Return true if type of P is derived from Checked_Pool;
10044 -----------------------------
10045 -- Is_Checked_Storage_Pool --
10046 -----------------------------
10048 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
10057 while T /= Etype (T) loop
10058 if Is_RTE (T, RE_Checked_Pool) then
10066 end Is_Checked_Storage_Pool;
10068 -- Start of processing for Insert_Dereference_Action
10071 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
10073 if not (Is_Checked_Storage_Pool (Pool)
10074 and then Comes_From_Source (Original_Node (Pnod)))
10080 Make_Procedure_Call_Statement (Loc,
10081 Name => New_Reference_To (
10082 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
10084 Parameter_Associations => New_List (
10088 New_Reference_To (Pool, Loc),
10090 -- Storage_Address. We use the attribute Pool_Address, which uses
10091 -- the pointer itself to find the address of the object, and which
10092 -- handles unconstrained arrays properly by computing the address
10093 -- of the template. i.e. the correct address of the corresponding
10096 Make_Attribute_Reference (Loc,
10097 Prefix => Duplicate_Subexpr_Move_Checks (N),
10098 Attribute_Name => Name_Pool_Address),
10100 -- Size_In_Storage_Elements
10102 Make_Op_Divide (Loc,
10104 Make_Attribute_Reference (Loc,
10106 Make_Explicit_Dereference (Loc,
10107 Duplicate_Subexpr_Move_Checks (N)),
10108 Attribute_Name => Name_Size),
10110 Make_Integer_Literal (Loc, System_Storage_Unit)),
10114 Make_Attribute_Reference (Loc,
10116 Make_Explicit_Dereference (Loc,
10117 Duplicate_Subexpr_Move_Checks (N)),
10118 Attribute_Name => Name_Alignment))));
10121 when RE_Not_Available =>
10123 end Insert_Dereference_Action;
10125 --------------------------------
10126 -- Integer_Promotion_Possible --
10127 --------------------------------
10129 function Integer_Promotion_Possible (N : Node_Id) return Boolean is
10130 Operand : constant Node_Id := Expression (N);
10131 Operand_Type : constant Entity_Id := Etype (Operand);
10132 Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
10135 pragma Assert (Nkind (N) = N_Type_Conversion);
10139 -- We only do the transformation for source constructs. We assume
10140 -- that the expander knows what it is doing when it generates code.
10142 Comes_From_Source (N)
10144 -- If the operand type is Short_Integer or Short_Short_Integer,
10145 -- then we will promote to Integer, which is available on all
10146 -- targets, and is sufficient to ensure no intermediate overflow.
10147 -- Furthermore it is likely to be as efficient or more efficient
10148 -- than using the smaller type for the computation so we do this
10149 -- unconditionally.
10152 (Root_Operand_Type = Base_Type (Standard_Short_Integer)
10154 Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
10156 -- Test for interesting operation, which includes addition,
10157 -- division, exponentiation, multiplication, subtraction, absolute
10158 -- value and unary negation. Unary "+" is omitted since it is a
10159 -- no-op and thus can't overflow.
10161 and then Nkind_In (Operand, N_Op_Abs,
10168 end Integer_Promotion_Possible;
10170 ------------------------------
10171 -- Make_Array_Comparison_Op --
10172 ------------------------------
10174 -- This is a hand-coded expansion of the following generic function:
10177 -- type elem is (<>);
10178 -- type index is (<>);
10179 -- type a is array (index range <>) of elem;
10181 -- function Gnnn (X : a; Y: a) return boolean is
10182 -- J : index := Y'first;
10185 -- if X'length = 0 then
10188 -- elsif Y'length = 0 then
10192 -- for I in X'range loop
10193 -- if X (I) = Y (J) then
10194 -- if J = Y'last then
10197 -- J := index'succ (J);
10201 -- return X (I) > Y (J);
10205 -- return X'length > Y'length;
10209 -- Note that since we are essentially doing this expansion by hand, we
10210 -- do not need to generate an actual or formal generic part, just the
10211 -- instantiated function itself.
10213 function Make_Array_Comparison_Op
10215 Nod : Node_Id) return Node_Id
10217 Loc : constant Source_Ptr := Sloc (Nod);
10219 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
10220 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
10221 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
10222 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10224 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
10226 Loop_Statement : Node_Id;
10227 Loop_Body : Node_Id;
10229 Inner_If : Node_Id;
10230 Final_Expr : Node_Id;
10231 Func_Body : Node_Id;
10232 Func_Name : Entity_Id;
10238 -- if J = Y'last then
10241 -- J := index'succ (J);
10245 Make_Implicit_If_Statement (Nod,
10248 Left_Opnd => New_Reference_To (J, Loc),
10250 Make_Attribute_Reference (Loc,
10251 Prefix => New_Reference_To (Y, Loc),
10252 Attribute_Name => Name_Last)),
10254 Then_Statements => New_List (
10255 Make_Exit_Statement (Loc)),
10259 Make_Assignment_Statement (Loc,
10260 Name => New_Reference_To (J, Loc),
10262 Make_Attribute_Reference (Loc,
10263 Prefix => New_Reference_To (Index, Loc),
10264 Attribute_Name => Name_Succ,
10265 Expressions => New_List (New_Reference_To (J, Loc))))));
10267 -- if X (I) = Y (J) then
10270 -- return X (I) > Y (J);
10274 Make_Implicit_If_Statement (Nod,
10278 Make_Indexed_Component (Loc,
10279 Prefix => New_Reference_To (X, Loc),
10280 Expressions => New_List (New_Reference_To (I, Loc))),
10283 Make_Indexed_Component (Loc,
10284 Prefix => New_Reference_To (Y, Loc),
10285 Expressions => New_List (New_Reference_To (J, Loc)))),
10287 Then_Statements => New_List (Inner_If),
10289 Else_Statements => New_List (
10290 Make_Simple_Return_Statement (Loc,
10294 Make_Indexed_Component (Loc,
10295 Prefix => New_Reference_To (X, Loc),
10296 Expressions => New_List (New_Reference_To (I, Loc))),
10299 Make_Indexed_Component (Loc,
10300 Prefix => New_Reference_To (Y, Loc),
10301 Expressions => New_List (
10302 New_Reference_To (J, Loc)))))));
10304 -- for I in X'range loop
10309 Make_Implicit_Loop_Statement (Nod,
10310 Identifier => Empty,
10312 Iteration_Scheme =>
10313 Make_Iteration_Scheme (Loc,
10314 Loop_Parameter_Specification =>
10315 Make_Loop_Parameter_Specification (Loc,
10316 Defining_Identifier => I,
10317 Discrete_Subtype_Definition =>
10318 Make_Attribute_Reference (Loc,
10319 Prefix => New_Reference_To (X, Loc),
10320 Attribute_Name => Name_Range))),
10322 Statements => New_List (Loop_Body));
10324 -- if X'length = 0 then
10326 -- elsif Y'length = 0 then
10329 -- for ... loop ... end loop;
10330 -- return X'length > Y'length;
10334 Make_Attribute_Reference (Loc,
10335 Prefix => New_Reference_To (X, Loc),
10336 Attribute_Name => Name_Length);
10339 Make_Attribute_Reference (Loc,
10340 Prefix => New_Reference_To (Y, Loc),
10341 Attribute_Name => Name_Length);
10345 Left_Opnd => Length1,
10346 Right_Opnd => Length2);
10349 Make_Implicit_If_Statement (Nod,
10353 Make_Attribute_Reference (Loc,
10354 Prefix => New_Reference_To (X, Loc),
10355 Attribute_Name => Name_Length),
10357 Make_Integer_Literal (Loc, 0)),
10361 Make_Simple_Return_Statement (Loc,
10362 Expression => New_Reference_To (Standard_False, Loc))),
10364 Elsif_Parts => New_List (
10365 Make_Elsif_Part (Loc,
10369 Make_Attribute_Reference (Loc,
10370 Prefix => New_Reference_To (Y, Loc),
10371 Attribute_Name => Name_Length),
10373 Make_Integer_Literal (Loc, 0)),
10377 Make_Simple_Return_Statement (Loc,
10378 Expression => New_Reference_To (Standard_True, Loc))))),
10380 Else_Statements => New_List (
10382 Make_Simple_Return_Statement (Loc,
10383 Expression => Final_Expr)));
10387 Formals := New_List (
10388 Make_Parameter_Specification (Loc,
10389 Defining_Identifier => X,
10390 Parameter_Type => New_Reference_To (Typ, Loc)),
10392 Make_Parameter_Specification (Loc,
10393 Defining_Identifier => Y,
10394 Parameter_Type => New_Reference_To (Typ, Loc)));
10396 -- function Gnnn (...) return boolean is
10397 -- J : index := Y'first;
10402 Func_Name := Make_Temporary (Loc, 'G');
10405 Make_Subprogram_Body (Loc,
10407 Make_Function_Specification (Loc,
10408 Defining_Unit_Name => Func_Name,
10409 Parameter_Specifications => Formals,
10410 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
10412 Declarations => New_List (
10413 Make_Object_Declaration (Loc,
10414 Defining_Identifier => J,
10415 Object_Definition => New_Reference_To (Index, Loc),
10417 Make_Attribute_Reference (Loc,
10418 Prefix => New_Reference_To (Y, Loc),
10419 Attribute_Name => Name_First))),
10421 Handled_Statement_Sequence =>
10422 Make_Handled_Sequence_Of_Statements (Loc,
10423 Statements => New_List (If_Stat)));
10426 end Make_Array_Comparison_Op;
10428 ---------------------------
10429 -- Make_Boolean_Array_Op --
10430 ---------------------------
10432 -- For logical operations on boolean arrays, expand in line the following,
10433 -- replacing 'and' with 'or' or 'xor' where needed:
10435 -- function Annn (A : typ; B: typ) return typ is
10438 -- for J in A'range loop
10439 -- C (J) := A (J) op B (J);
10444 -- Here typ is the boolean array type
10446 function Make_Boolean_Array_Op
10448 N : Node_Id) return Node_Id
10450 Loc : constant Source_Ptr := Sloc (N);
10452 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
10453 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
10454 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
10455 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10463 Func_Name : Entity_Id;
10464 Func_Body : Node_Id;
10465 Loop_Statement : Node_Id;
10469 Make_Indexed_Component (Loc,
10470 Prefix => New_Reference_To (A, Loc),
10471 Expressions => New_List (New_Reference_To (J, Loc)));
10474 Make_Indexed_Component (Loc,
10475 Prefix => New_Reference_To (B, Loc),
10476 Expressions => New_List (New_Reference_To (J, Loc)));
10479 Make_Indexed_Component (Loc,
10480 Prefix => New_Reference_To (C, Loc),
10481 Expressions => New_List (New_Reference_To (J, Loc)));
10483 if Nkind (N) = N_Op_And then
10487 Right_Opnd => B_J);
10489 elsif Nkind (N) = N_Op_Or then
10493 Right_Opnd => B_J);
10499 Right_Opnd => B_J);
10503 Make_Implicit_Loop_Statement (N,
10504 Identifier => Empty,
10506 Iteration_Scheme =>
10507 Make_Iteration_Scheme (Loc,
10508 Loop_Parameter_Specification =>
10509 Make_Loop_Parameter_Specification (Loc,
10510 Defining_Identifier => J,
10511 Discrete_Subtype_Definition =>
10512 Make_Attribute_Reference (Loc,
10513 Prefix => New_Reference_To (A, Loc),
10514 Attribute_Name => Name_Range))),
10516 Statements => New_List (
10517 Make_Assignment_Statement (Loc,
10519 Expression => Op)));
10521 Formals := New_List (
10522 Make_Parameter_Specification (Loc,
10523 Defining_Identifier => A,
10524 Parameter_Type => New_Reference_To (Typ, Loc)),
10526 Make_Parameter_Specification (Loc,
10527 Defining_Identifier => B,
10528 Parameter_Type => New_Reference_To (Typ, Loc)));
10530 Func_Name := Make_Temporary (Loc, 'A');
10531 Set_Is_Inlined (Func_Name);
10534 Make_Subprogram_Body (Loc,
10536 Make_Function_Specification (Loc,
10537 Defining_Unit_Name => Func_Name,
10538 Parameter_Specifications => Formals,
10539 Result_Definition => New_Reference_To (Typ, Loc)),
10541 Declarations => New_List (
10542 Make_Object_Declaration (Loc,
10543 Defining_Identifier => C,
10544 Object_Definition => New_Reference_To (Typ, Loc))),
10546 Handled_Statement_Sequence =>
10547 Make_Handled_Sequence_Of_Statements (Loc,
10548 Statements => New_List (
10550 Make_Simple_Return_Statement (Loc,
10551 Expression => New_Reference_To (C, Loc)))));
10554 end Make_Boolean_Array_Op;
10556 --------------------------------
10557 -- Optimize_Length_Comparison --
10558 --------------------------------
10560 procedure Optimize_Length_Comparison (N : Node_Id) is
10561 Loc : constant Source_Ptr := Sloc (N);
10562 Typ : constant Entity_Id := Etype (N);
10567 -- First and Last attribute reference nodes, which end up as left and
10568 -- right operands of the optimized result.
10571 -- True for comparison operand of zero
10574 -- Comparison operand, set only if Is_Zero is false
10577 -- Entity whose length is being compared
10580 -- Integer_Literal node for length attribute expression, or Empty
10581 -- if there is no such expression present.
10584 -- Type of array index to which 'Length is applied
10586 Op : Node_Kind := Nkind (N);
10587 -- Kind of comparison operator, gets flipped if operands backwards
10589 function Is_Optimizable (N : Node_Id) return Boolean;
10590 -- Tests N to see if it is an optimizable comparison value (defined as
10591 -- constant zero or one, or something else where the value is known to
10592 -- be positive and in the range of 32-bits, and where the corresponding
10593 -- Length value is also known to be 32-bits. If result is true, sets
10594 -- Is_Zero, Ityp, and Comp accordingly.
10596 function Is_Entity_Length (N : Node_Id) return Boolean;
10597 -- Tests if N is a length attribute applied to a simple entity. If so,
10598 -- returns True, and sets Ent to the entity, and Index to the integer
10599 -- literal provided as an attribute expression, or to Empty if none.
10600 -- Also returns True if the expression is a generated type conversion
10601 -- whose expression is of the desired form. This latter case arises
10602 -- when Apply_Universal_Integer_Attribute_Check installs a conversion
10603 -- to check for being in range, which is not needed in this context.
10604 -- Returns False if neither condition holds.
10606 function Prepare_64 (N : Node_Id) return Node_Id;
10607 -- Given a discrete expression, returns a Long_Long_Integer typed
10608 -- expression representing the underlying value of the expression.
10609 -- This is done with an unchecked conversion to the result type. We
10610 -- use unchecked conversion to handle the enumeration type case.
10612 ----------------------
10613 -- Is_Entity_Length --
10614 ----------------------
10616 function Is_Entity_Length (N : Node_Id) return Boolean is
10618 if Nkind (N) = N_Attribute_Reference
10619 and then Attribute_Name (N) = Name_Length
10620 and then Is_Entity_Name (Prefix (N))
10622 Ent := Entity (Prefix (N));
10624 if Present (Expressions (N)) then
10625 Index := First (Expressions (N));
10632 elsif Nkind (N) = N_Type_Conversion
10633 and then not Comes_From_Source (N)
10635 return Is_Entity_Length (Expression (N));
10640 end Is_Entity_Length;
10642 --------------------
10643 -- Is_Optimizable --
10644 --------------------
10646 function Is_Optimizable (N : Node_Id) return Boolean is
10654 if Compile_Time_Known_Value (N) then
10655 Val := Expr_Value (N);
10657 if Val = Uint_0 then
10662 elsif Val = Uint_1 then
10669 -- Here we have to make sure of being within 32-bits
10671 Determine_Range (N, OK, Lo, Hi, Assume_Valid => True);
10674 or else Lo < Uint_1
10675 or else Hi > UI_From_Int (Int'Last)
10680 -- Comparison value was within range, so now we must check the index
10681 -- value to make sure it is also within 32-bits.
10683 Indx := First_Index (Etype (Ent));
10685 if Present (Index) then
10686 for J in 2 .. UI_To_Int (Intval (Index)) loop
10691 Ityp := Etype (Indx);
10693 if Esize (Ityp) > 32 then
10700 end Is_Optimizable;
10706 function Prepare_64 (N : Node_Id) return Node_Id is
10708 return Unchecked_Convert_To (Standard_Long_Long_Integer, N);
10711 -- Start of processing for Optimize_Length_Comparison
10714 -- Nothing to do if not a comparison
10716 if Op not in N_Op_Compare then
10720 -- Nothing to do if special -gnatd.P debug flag set
10722 if Debug_Flag_Dot_PP then
10726 -- Ent'Length op 0/1
10728 if Is_Entity_Length (Left_Opnd (N))
10729 and then Is_Optimizable (Right_Opnd (N))
10733 -- 0/1 op Ent'Length
10735 elsif Is_Entity_Length (Right_Opnd (N))
10736 and then Is_Optimizable (Left_Opnd (N))
10738 -- Flip comparison to opposite sense
10741 when N_Op_Lt => Op := N_Op_Gt;
10742 when N_Op_Le => Op := N_Op_Ge;
10743 when N_Op_Gt => Op := N_Op_Lt;
10744 when N_Op_Ge => Op := N_Op_Le;
10745 when others => null;
10748 -- Else optimization not possible
10754 -- Fall through if we will do the optimization
10756 -- Cases to handle:
10758 -- X'Length = 0 => X'First > X'Last
10759 -- X'Length = 1 => X'First = X'Last
10760 -- X'Length = n => X'First + (n - 1) = X'Last
10762 -- X'Length /= 0 => X'First <= X'Last
10763 -- X'Length /= 1 => X'First /= X'Last
10764 -- X'Length /= n => X'First + (n - 1) /= X'Last
10766 -- X'Length >= 0 => always true, warn
10767 -- X'Length >= 1 => X'First <= X'Last
10768 -- X'Length >= n => X'First + (n - 1) <= X'Last
10770 -- X'Length > 0 => X'First <= X'Last
10771 -- X'Length > 1 => X'First < X'Last
10772 -- X'Length > n => X'First + (n - 1) < X'Last
10774 -- X'Length <= 0 => X'First > X'Last (warn, could be =)
10775 -- X'Length <= 1 => X'First >= X'Last
10776 -- X'Length <= n => X'First + (n - 1) >= X'Last
10778 -- X'Length < 0 => always false (warn)
10779 -- X'Length < 1 => X'First > X'Last
10780 -- X'Length < n => X'First + (n - 1) > X'Last
10782 -- Note: for the cases of n (not constant 0,1), we require that the
10783 -- corresponding index type be integer or shorter (i.e. not 64-bit),
10784 -- and the same for the comparison value. Then we do the comparison
10785 -- using 64-bit arithmetic (actually long long integer), so that we
10786 -- cannot have overflow intefering with the result.
10788 -- First deal with warning cases
10797 Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc)));
10798 Analyze_And_Resolve (N, Typ);
10799 Warn_On_Known_Condition (N);
10806 Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc)));
10807 Analyze_And_Resolve (N, Typ);
10808 Warn_On_Known_Condition (N);
10812 if Constant_Condition_Warnings
10813 and then Comes_From_Source (Original_Node (N))
10815 Error_Msg_N ("could replace by ""'=""?", N);
10825 -- Build the First reference we will use
10828 Make_Attribute_Reference (Loc,
10829 Prefix => New_Occurrence_Of (Ent, Loc),
10830 Attribute_Name => Name_First);
10832 if Present (Index) then
10833 Set_Expressions (Left, New_List (New_Copy (Index)));
10836 -- If general value case, then do the addition of (n - 1), and
10837 -- also add the needed conversions to type Long_Long_Integer.
10839 if Present (Comp) then
10842 Left_Opnd => Prepare_64 (Left),
10844 Make_Op_Subtract (Loc,
10845 Left_Opnd => Prepare_64 (Comp),
10846 Right_Opnd => Make_Integer_Literal (Loc, 1)));
10849 -- Build the Last reference we will use
10852 Make_Attribute_Reference (Loc,
10853 Prefix => New_Occurrence_Of (Ent, Loc),
10854 Attribute_Name => Name_Last);
10856 if Present (Index) then
10857 Set_Expressions (Right, New_List (New_Copy (Index)));
10860 -- If general operand, convert Last reference to Long_Long_Integer
10862 if Present (Comp) then
10863 Right := Prepare_64 (Right);
10866 -- Check for cases to optimize
10868 -- X'Length = 0 => X'First > X'Last
10869 -- X'Length < 1 => X'First > X'Last
10870 -- X'Length < n => X'First + (n - 1) > X'Last
10872 if (Is_Zero and then Op = N_Op_Eq)
10873 or else (not Is_Zero and then Op = N_Op_Lt)
10878 Right_Opnd => Right);
10880 -- X'Length = 1 => X'First = X'Last
10881 -- X'Length = n => X'First + (n - 1) = X'Last
10883 elsif not Is_Zero and then Op = N_Op_Eq then
10887 Right_Opnd => Right);
10889 -- X'Length /= 0 => X'First <= X'Last
10890 -- X'Length > 0 => X'First <= X'Last
10892 elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then
10896 Right_Opnd => Right);
10898 -- X'Length /= 1 => X'First /= X'Last
10899 -- X'Length /= n => X'First + (n - 1) /= X'Last
10901 elsif not Is_Zero and then Op = N_Op_Ne then
10905 Right_Opnd => Right);
10907 -- X'Length >= 1 => X'First <= X'Last
10908 -- X'Length >= n => X'First + (n - 1) <= X'Last
10910 elsif not Is_Zero and then Op = N_Op_Ge then
10914 Right_Opnd => Right);
10916 -- X'Length > 1 => X'First < X'Last
10917 -- X'Length > n => X'First + (n = 1) < X'Last
10919 elsif not Is_Zero and then Op = N_Op_Gt then
10923 Right_Opnd => Right);
10925 -- X'Length <= 1 => X'First >= X'Last
10926 -- X'Length <= n => X'First + (n - 1) >= X'Last
10928 elsif not Is_Zero and then Op = N_Op_Le then
10932 Right_Opnd => Right);
10934 -- Should not happen at this stage
10937 raise Program_Error;
10940 -- Rewrite and finish up
10942 Rewrite (N, Result);
10943 Analyze_And_Resolve (N, Typ);
10945 end Optimize_Length_Comparison;
10947 ------------------------
10948 -- Rewrite_Comparison --
10949 ------------------------
10951 procedure Rewrite_Comparison (N : Node_Id) is
10952 Warning_Generated : Boolean := False;
10953 -- Set to True if first pass with Assume_Valid generates a warning in
10954 -- which case we skip the second pass to avoid warning overloaded.
10957 -- Set to Standard_True or Standard_False
10960 if Nkind (N) = N_Type_Conversion then
10961 Rewrite_Comparison (Expression (N));
10964 elsif Nkind (N) not in N_Op_Compare then
10968 -- Now start looking at the comparison in detail. We potentially go
10969 -- through this loop twice. The first time, Assume_Valid is set False
10970 -- in the call to Compile_Time_Compare. If this call results in a
10971 -- clear result of always True or Always False, that's decisive and
10972 -- we are done. Otherwise we repeat the processing with Assume_Valid
10973 -- set to True to generate additional warnings. We can skip that step
10974 -- if Constant_Condition_Warnings is False.
10976 for AV in False .. True loop
10978 Typ : constant Entity_Id := Etype (N);
10979 Op1 : constant Node_Id := Left_Opnd (N);
10980 Op2 : constant Node_Id := Right_Opnd (N);
10982 Res : constant Compare_Result :=
10983 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
10984 -- Res indicates if compare outcome can be compile time determined
10986 True_Result : Boolean;
10987 False_Result : Boolean;
10990 case N_Op_Compare (Nkind (N)) is
10992 True_Result := Res = EQ;
10993 False_Result := Res = LT or else Res = GT or else Res = NE;
10996 True_Result := Res in Compare_GE;
10997 False_Result := Res = LT;
11000 and then Constant_Condition_Warnings
11001 and then Comes_From_Source (Original_Node (N))
11002 and then Nkind (Original_Node (N)) = N_Op_Ge
11003 and then not In_Instance
11004 and then Is_Integer_Type (Etype (Left_Opnd (N)))
11005 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
11008 ("can never be greater than, could replace by ""'=""?", N);
11009 Warning_Generated := True;
11013 True_Result := Res = GT;
11014 False_Result := Res in Compare_LE;
11017 True_Result := Res = LT;
11018 False_Result := Res in Compare_GE;
11021 True_Result := Res in Compare_LE;
11022 False_Result := Res = GT;
11025 and then Constant_Condition_Warnings
11026 and then Comes_From_Source (Original_Node (N))
11027 and then Nkind (Original_Node (N)) = N_Op_Le
11028 and then not In_Instance
11029 and then Is_Integer_Type (Etype (Left_Opnd (N)))
11030 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
11033 ("can never be less than, could replace by ""'=""?", N);
11034 Warning_Generated := True;
11038 True_Result := Res = NE or else Res = GT or else Res = LT;
11039 False_Result := Res = EQ;
11042 -- If this is the first iteration, then we actually convert the
11043 -- comparison into True or False, if the result is certain.
11046 if True_Result or False_Result then
11047 if True_Result then
11048 Result := Standard_True;
11050 Result := Standard_False;
11055 New_Occurrence_Of (Result, Sloc (N))));
11056 Analyze_And_Resolve (N, Typ);
11057 Warn_On_Known_Condition (N);
11061 -- If this is the second iteration (AV = True), and the original
11062 -- node comes from source and we are not in an instance, then give
11063 -- a warning if we know result would be True or False. Note: we
11064 -- know Constant_Condition_Warnings is set if we get here.
11066 elsif Comes_From_Source (Original_Node (N))
11067 and then not In_Instance
11069 if True_Result then
11071 ("condition can only be False if invalid values present?",
11073 elsif False_Result then
11075 ("condition can only be True if invalid values present?",
11081 -- Skip second iteration if not warning on constant conditions or
11082 -- if the first iteration already generated a warning of some kind or
11083 -- if we are in any case assuming all values are valid (so that the
11084 -- first iteration took care of the valid case).
11086 exit when not Constant_Condition_Warnings;
11087 exit when Warning_Generated;
11088 exit when Assume_No_Invalid_Values;
11090 end Rewrite_Comparison;
11092 ----------------------------
11093 -- Safe_In_Place_Array_Op --
11094 ----------------------------
11096 function Safe_In_Place_Array_Op
11099 Op2 : Node_Id) return Boolean
11101 Target : Entity_Id;
11103 function Is_Safe_Operand (Op : Node_Id) return Boolean;
11104 -- Operand is safe if it cannot overlap part of the target of the
11105 -- operation. If the operand and the target are identical, the operand
11106 -- is safe. The operand can be empty in the case of negation.
11108 function Is_Unaliased (N : Node_Id) return Boolean;
11109 -- Check that N is a stand-alone entity
11115 function Is_Unaliased (N : Node_Id) return Boolean is
11119 and then No (Address_Clause (Entity (N)))
11120 and then No (Renamed_Object (Entity (N)));
11123 ---------------------
11124 -- Is_Safe_Operand --
11125 ---------------------
11127 function Is_Safe_Operand (Op : Node_Id) return Boolean is
11132 elsif Is_Entity_Name (Op) then
11133 return Is_Unaliased (Op);
11135 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
11136 return Is_Unaliased (Prefix (Op));
11138 elsif Nkind (Op) = N_Slice then
11140 Is_Unaliased (Prefix (Op))
11141 and then Entity (Prefix (Op)) /= Target;
11143 elsif Nkind (Op) = N_Op_Not then
11144 return Is_Safe_Operand (Right_Opnd (Op));
11149 end Is_Safe_Operand;
11151 -- Start of processing for Is_Safe_In_Place_Array_Op
11154 -- Skip this processing if the component size is different from system
11155 -- storage unit (since at least for NOT this would cause problems).
11157 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
11160 -- Cannot do in place stuff on VM_Target since cannot pass addresses
11162 elsif VM_Target /= No_VM then
11165 -- Cannot do in place stuff if non-standard Boolean representation
11167 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
11170 elsif not Is_Unaliased (Lhs) then
11174 Target := Entity (Lhs);
11175 return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
11177 end Safe_In_Place_Array_Op;
11179 -----------------------
11180 -- Tagged_Membership --
11181 -----------------------
11183 -- There are two different cases to consider depending on whether the right
11184 -- operand is a class-wide type or not. If not we just compare the actual
11185 -- tag of the left expr to the target type tag:
11187 -- Left_Expr.Tag = Right_Type'Tag;
11189 -- If it is a class-wide type we use the RT function CW_Membership which is
11190 -- usually implemented by looking in the ancestor tables contained in the
11191 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
11193 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
11194 -- function IW_Membership which is usually implemented by looking in the
11195 -- table of abstract interface types plus the ancestor table contained in
11196 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
11198 procedure Tagged_Membership
11200 SCIL_Node : out Node_Id;
11201 Result : out Node_Id)
11203 Left : constant Node_Id := Left_Opnd (N);
11204 Right : constant Node_Id := Right_Opnd (N);
11205 Loc : constant Source_Ptr := Sloc (N);
11207 Full_R_Typ : Entity_Id;
11208 Left_Type : Entity_Id;
11209 New_Node : Node_Id;
11210 Right_Type : Entity_Id;
11214 SCIL_Node := Empty;
11216 -- Handle entities from the limited view
11218 Left_Type := Available_View (Etype (Left));
11219 Right_Type := Available_View (Etype (Right));
11221 -- In the case where the type is an access type, the test is applied
11222 -- using the designated types (needed in Ada 2012 for implicit anonymous
11223 -- access conversions, for AI05-0149).
11225 if Is_Access_Type (Right_Type) then
11226 Left_Type := Designated_Type (Left_Type);
11227 Right_Type := Designated_Type (Right_Type);
11230 if Is_Class_Wide_Type (Left_Type) then
11231 Left_Type := Root_Type (Left_Type);
11234 if Is_Class_Wide_Type (Right_Type) then
11235 Full_R_Typ := Underlying_Type (Root_Type (Right_Type));
11237 Full_R_Typ := Underlying_Type (Right_Type);
11241 Make_Selected_Component (Loc,
11242 Prefix => Relocate_Node (Left),
11244 New_Reference_To (First_Tag_Component (Left_Type), Loc));
11246 if Is_Class_Wide_Type (Right_Type) then
11248 -- No need to issue a run-time check if we statically know that the
11249 -- result of this membership test is always true. For example,
11250 -- considering the following declarations:
11252 -- type Iface is interface;
11253 -- type T is tagged null record;
11254 -- type DT is new T and Iface with null record;
11259 -- These membership tests are always true:
11262 -- Obj2 in T'Class;
11263 -- Obj2 in Iface'Class;
11265 -- We do not need to handle cases where the membership is illegal.
11268 -- Obj1 in DT'Class; -- Compile time error
11269 -- Obj1 in Iface'Class; -- Compile time error
11271 if not Is_Class_Wide_Type (Left_Type)
11272 and then (Is_Ancestor (Etype (Right_Type), Left_Type,
11273 Use_Full_View => True)
11274 or else (Is_Interface (Etype (Right_Type))
11275 and then Interface_Present_In_Ancestor
11277 Iface => Etype (Right_Type))))
11279 Result := New_Reference_To (Standard_True, Loc);
11283 -- Ada 2005 (AI-251): Class-wide applied to interfaces
11285 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
11287 -- Support to: "Iface_CW_Typ in Typ'Class"
11289 or else Is_Interface (Left_Type)
11291 -- Issue error if IW_Membership operation not available in a
11292 -- configurable run time setting.
11294 if not RTE_Available (RE_IW_Membership) then
11296 ("dynamic membership test on interface types", N);
11302 Make_Function_Call (Loc,
11303 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
11304 Parameter_Associations => New_List (
11305 Make_Attribute_Reference (Loc,
11307 Attribute_Name => Name_Address),
11309 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))),
11312 -- Ada 95: Normal case
11315 Build_CW_Membership (Loc,
11316 Obj_Tag_Node => Obj_Tag,
11319 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc),
11321 New_Node => New_Node);
11323 -- Generate the SCIL node for this class-wide membership test.
11324 -- Done here because the previous call to Build_CW_Membership
11325 -- relocates Obj_Tag.
11327 if Generate_SCIL then
11328 SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
11329 Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
11330 Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
11333 Result := New_Node;
11336 -- Right_Type is not a class-wide type
11339 -- No need to check the tag of the object if Right_Typ is abstract
11341 if Is_Abstract_Type (Right_Type) then
11342 Result := New_Reference_To (Standard_False, Loc);
11347 Left_Opnd => Obj_Tag,
11350 (Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc));
11353 end Tagged_Membership;
11355 ------------------------------
11356 -- Unary_Op_Validity_Checks --
11357 ------------------------------
11359 procedure Unary_Op_Validity_Checks (N : Node_Id) is
11361 if Validity_Checks_On and Validity_Check_Operands then
11362 Ensure_Valid (Right_Opnd (N));
11364 end Unary_Op_Validity_Checks;