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, Relocate_Node (N)));
598 -- 2) Add the conversion to displace the pointer to reference
599 -- the secondary dispatch table.
601 Rewrite (N, Convert_To (Dtyp, Relocate_Node (N)));
602 Analyze_And_Resolve (N, Dtyp);
604 -- 3) The 'access to the secondary dispatch table will be used
605 -- as the value returned by the allocator.
608 Make_Attribute_Reference (Loc,
609 Prefix => Relocate_Node (N),
610 Attribute_Name => Name_Access));
611 Set_Etype (N, Saved_Typ);
615 -- If the type of the allocator expression is an interface type we
616 -- generate a run-time call to displace "this" to reference the
617 -- component containing the pointer to the secondary dispatch table
618 -- or else raise Constraint_Error if the actual object does not
619 -- implement the target interface. This case corresponds with the
620 -- following example:
622 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
624 -- return new Iface_2'Class'(Obj);
629 Unchecked_Convert_To (PtrT,
630 Make_Function_Call (Loc,
631 Name => New_Reference_To (RTE (RE_Displace), Loc),
632 Parameter_Associations => New_List (
633 Unchecked_Convert_To (RTE (RE_Address),
639 (Access_Disp_Table (Etype (Base_Type (Dtyp))))),
641 Analyze_And_Resolve (N, PtrT);
644 end Displace_Allocator_Pointer;
646 ---------------------------------
647 -- Expand_Allocator_Expression --
648 ---------------------------------
650 procedure Expand_Allocator_Expression (N : Node_Id) is
651 Loc : constant Source_Ptr := Sloc (N);
652 Exp : constant Node_Id := Expression (Expression (N));
653 PtrT : constant Entity_Id := Etype (N);
654 DesigT : constant Entity_Id := Designated_Type (PtrT);
656 procedure Apply_Accessibility_Check
658 Built_In_Place : Boolean := False);
659 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
660 -- type, generate an accessibility check to verify that the level of the
661 -- type of the created object is not deeper than the level of the access
662 -- type. If the type of the qualified expression is class- wide, then
663 -- always generate the check (except in the case where it is known to be
664 -- unnecessary, see comment below). Otherwise, only generate the check
665 -- if the level of the qualified expression type is statically deeper
666 -- than the access type.
668 -- Although the static accessibility will generally have been performed
669 -- as a legality check, it won't have been done in cases where the
670 -- allocator appears in generic body, so a run-time check is needed in
671 -- general. One special case is when the access type is declared in the
672 -- same scope as the class-wide allocator, in which case the check can
673 -- never fail, so it need not be generated.
675 -- As an open issue, there seem to be cases where the static level
676 -- associated with the class-wide object's underlying type is not
677 -- sufficient to perform the proper accessibility check, such as for
678 -- allocators in nested subprograms or accept statements initialized by
679 -- class-wide formals when the actual originates outside at a deeper
680 -- static level. The nested subprogram case might require passing
681 -- accessibility levels along with class-wide parameters, and the task
682 -- case seems to be an actual gap in the language rules that needs to
683 -- be fixed by the ARG. ???
685 -------------------------------
686 -- Apply_Accessibility_Check --
687 -------------------------------
689 procedure Apply_Accessibility_Check
691 Built_In_Place : Boolean := False)
696 if Ada_Version >= Ada_2005
697 and then Is_Class_Wide_Type (DesigT)
698 and then not Scope_Suppress (Accessibility_Check)
700 (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT)
702 (Is_Class_Wide_Type (Etype (Exp))
703 and then Scope (PtrT) /= Current_Scope))
705 -- If the allocator was built in place Ref is already a reference
706 -- to the access object initialized to the result of the allocator
707 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise
708 -- it is the entity associated with the object containing the
709 -- address of the allocated object.
711 if Built_In_Place then
712 New_Node := New_Copy (Ref);
714 New_Node := New_Reference_To (Ref, Loc);
718 Make_Attribute_Reference (Loc,
720 Attribute_Name => Name_Tag);
722 if Tagged_Type_Expansion then
723 New_Node := Build_Get_Access_Level (Loc, New_Node);
725 elsif VM_Target /= No_VM then
727 Make_Function_Call (Loc,
728 Name => New_Reference_To (RTE (RE_Get_Access_Level), Loc),
729 Parameter_Associations => New_List (New_Node));
731 -- Cannot generate the runtime check
738 Make_Raise_Program_Error (Loc,
741 Left_Opnd => New_Node,
743 Make_Integer_Literal (Loc, Type_Access_Level (PtrT))),
744 Reason => PE_Accessibility_Check_Failed));
746 end Apply_Accessibility_Check;
750 Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp);
751 Indic : constant Node_Id := Subtype_Mark (Expression (N));
752 T : constant Entity_Id := Entity (Indic);
754 Tag_Assign : Node_Id;
758 TagT : Entity_Id := Empty;
759 -- Type used as source for tag assignment
761 TagR : Node_Id := Empty;
762 -- Target reference for tag assignment
764 -- Start of processing for Expand_Allocator_Expression
767 -- In the case of an Ada 2012 allocator whose initial value comes from a
768 -- function call, pass "the accessibility level determined by the point
769 -- of call" (AI05-0234) to the function. Conceptually, this belongs in
770 -- Expand_Call but it couldn't be done there (because the Etype of the
771 -- allocator wasn't set then) so we generate the parameter here. See
772 -- the Boolean variable Defer in (a block within) Expand_Call.
774 if Ada_Version >= Ada_2012 and then Nkind (Exp) = N_Function_Call then
779 if Nkind (Name (Exp)) = N_Explicit_Dereference then
780 Subp := Designated_Type (Etype (Prefix (Name (Exp))));
782 Subp := Entity (Name (Exp));
785 Subp := Ultimate_Alias (Subp);
787 if Present (Extra_Accessibility_Of_Result (Subp)) then
788 Add_Extra_Actual_To_Call
789 (Subprogram_Call => Exp,
790 Extra_Formal => Extra_Accessibility_Of_Result (Subp),
791 Extra_Actual => Dynamic_Accessibility_Level (PtrT));
796 -- Would be nice to comment the branches of this very long if ???
798 if Is_Tagged_Type (T) or else Needs_Finalization (T) then
799 if Is_CPP_Constructor_Call (Exp) then
802 -- Pnnn : constant ptr_T := new (T);
803 -- Init (Pnnn.all,...);
805 -- Allocate the object without an expression
807 Node := Relocate_Node (N);
808 Set_Expression (Node, New_Reference_To (Etype (Exp), Loc));
810 -- Avoid its expansion to avoid generating a call to the default
815 Temp := Make_Temporary (Loc, 'P', N);
818 Make_Object_Declaration (Loc,
819 Defining_Identifier => Temp,
820 Constant_Present => True,
821 Object_Definition => New_Reference_To (PtrT, Loc),
823 Insert_Action (N, Temp_Decl);
825 Apply_Accessibility_Check (Temp);
827 -- Locate the enclosing list and insert the C++ constructor call
834 while not Is_List_Member (P) loop
838 Insert_List_After_And_Analyze (P,
839 Build_Initialization_Call (Loc,
841 Make_Explicit_Dereference (Loc,
842 Prefix => New_Reference_To (Temp, Loc)),
844 Constructor_Ref => Exp));
847 Rewrite (N, New_Reference_To (Temp, Loc));
848 Analyze_And_Resolve (N, PtrT);
852 -- Ada 2005 (AI-318-02): If the initialization expression is a call
853 -- to a build-in-place function, then access to the allocated object
854 -- must be passed to the function. Currently we limit such functions
855 -- to those with constrained limited result subtypes, but eventually
856 -- we plan to expand the allowed forms of functions that are treated
857 -- as build-in-place.
859 if Ada_Version >= Ada_2005
860 and then Is_Build_In_Place_Function_Call (Exp)
862 Make_Build_In_Place_Call_In_Allocator (N, Exp);
863 Apply_Accessibility_Check (N, Built_In_Place => True);
867 -- Actions inserted before:
868 -- Temp : constant ptr_T := new T'(Expression);
869 -- Temp._tag = T'tag; -- when not class-wide
870 -- [Deep_]Adjust (Temp.all);
872 -- We analyze by hand the new internal allocator to avoid any
873 -- recursion and inappropriate call to Initialize
875 -- We don't want to remove side effects when the expression must be
876 -- built in place. In the case of a build-in-place function call,
877 -- that could lead to a duplication of the call, which was already
878 -- substituted for the allocator.
880 if not Aggr_In_Place then
881 Remove_Side_Effects (Exp);
884 Temp := Make_Temporary (Loc, 'P', N);
886 -- For a class wide allocation generate the following code:
888 -- type Equiv_Record is record ... end record;
889 -- implicit subtype CW is <Class_Wide_Subytpe>;
890 -- temp : PtrT := new CW'(CW!(expr));
892 if Is_Class_Wide_Type (T) then
893 Expand_Subtype_From_Expr (Empty, T, Indic, Exp);
895 -- Ada 2005 (AI-251): If the expression is a class-wide interface
896 -- object we generate code to move up "this" to reference the
897 -- base of the object before allocating the new object.
899 -- Note that Exp'Address is recursively expanded into a call
900 -- to Base_Address (Exp.Tag)
902 if Is_Class_Wide_Type (Etype (Exp))
903 and then Is_Interface (Etype (Exp))
904 and then Tagged_Type_Expansion
908 Unchecked_Convert_To (Entity (Indic),
909 Make_Explicit_Dereference (Loc,
910 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
911 Make_Attribute_Reference (Loc,
913 Attribute_Name => Name_Address)))));
917 Unchecked_Convert_To (Entity (Indic), Exp));
920 Analyze_And_Resolve (Expression (N), Entity (Indic));
923 -- Processing for allocators returning non-interface types
925 if not Is_Interface (Directly_Designated_Type (PtrT)) then
926 if Aggr_In_Place then
928 Make_Object_Declaration (Loc,
929 Defining_Identifier => Temp,
930 Object_Definition => New_Reference_To (PtrT, Loc),
934 New_Reference_To (Etype (Exp), Loc)));
936 -- Copy the Comes_From_Source flag for the allocator we just
937 -- built, since logically this allocator is a replacement of
938 -- the original allocator node. This is for proper handling of
939 -- restriction No_Implicit_Heap_Allocations.
941 Set_Comes_From_Source
942 (Expression (Temp_Decl), Comes_From_Source (N));
944 Set_No_Initialization (Expression (Temp_Decl));
945 Insert_Action (N, Temp_Decl);
947 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
948 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
950 -- Attach the object to the associated finalization master.
951 -- This is done manually on .NET/JVM since those compilers do
952 -- no support pools and can't benefit from internally generated
953 -- Allocate / Deallocate procedures.
955 if VM_Target /= No_VM
956 and then Is_Controlled (DesigT)
957 and then Present (Finalization_Master (PtrT))
962 New_Reference_To (Temp, Loc),
967 Node := Relocate_Node (N);
971 Make_Object_Declaration (Loc,
972 Defining_Identifier => Temp,
973 Constant_Present => True,
974 Object_Definition => New_Reference_To (PtrT, Loc),
977 Insert_Action (N, Temp_Decl);
978 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
980 -- Attach the object to the associated finalization master.
981 -- This is done manually on .NET/JVM since those compilers do
982 -- no support pools and can't benefit from internally generated
983 -- Allocate / Deallocate procedures.
985 if VM_Target /= No_VM
986 and then Is_Controlled (DesigT)
987 and then Present (Finalization_Master (PtrT))
992 New_Reference_To (Temp, Loc),
997 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
998 -- interface type. In this case we use the type of the qualified
999 -- expression to allocate the object.
1003 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
1008 Make_Full_Type_Declaration (Loc,
1009 Defining_Identifier => Def_Id,
1011 Make_Access_To_Object_Definition (Loc,
1012 All_Present => True,
1013 Null_Exclusion_Present => False,
1014 Constant_Present => False,
1015 Subtype_Indication =>
1016 New_Reference_To (Etype (Exp), Loc)));
1018 Insert_Action (N, New_Decl);
1020 -- Inherit the allocation-related attributes from the original
1023 Set_Finalization_Master (Def_Id, Finalization_Master (PtrT));
1025 Set_Associated_Storage_Pool (Def_Id,
1026 Associated_Storage_Pool (PtrT));
1028 -- Declare the object using the previous type declaration
1030 if Aggr_In_Place then
1032 Make_Object_Declaration (Loc,
1033 Defining_Identifier => Temp,
1034 Object_Definition => New_Reference_To (Def_Id, Loc),
1036 Make_Allocator (Loc,
1037 New_Reference_To (Etype (Exp), Loc)));
1039 -- Copy the Comes_From_Source flag for the allocator we just
1040 -- built, since logically this allocator is a replacement of
1041 -- the original allocator node. This is for proper handling
1042 -- of restriction No_Implicit_Heap_Allocations.
1044 Set_Comes_From_Source
1045 (Expression (Temp_Decl), Comes_From_Source (N));
1047 Set_No_Initialization (Expression (Temp_Decl));
1048 Insert_Action (N, Temp_Decl);
1050 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1051 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
1054 Node := Relocate_Node (N);
1055 Set_Analyzed (Node);
1058 Make_Object_Declaration (Loc,
1059 Defining_Identifier => Temp,
1060 Constant_Present => True,
1061 Object_Definition => New_Reference_To (Def_Id, Loc),
1062 Expression => Node);
1064 Insert_Action (N, Temp_Decl);
1065 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1068 -- Generate an additional object containing the address of the
1069 -- returned object. The type of this second object declaration
1070 -- is the correct type required for the common processing that
1071 -- is still performed by this subprogram. The displacement of
1072 -- this pointer to reference the component associated with the
1073 -- interface type will be done at the end of common processing.
1076 Make_Object_Declaration (Loc,
1077 Defining_Identifier => Make_Temporary (Loc, 'P'),
1078 Object_Definition => New_Reference_To (PtrT, Loc),
1080 Unchecked_Convert_To (PtrT,
1081 New_Reference_To (Temp, Loc)));
1083 Insert_Action (N, New_Decl);
1085 Temp_Decl := New_Decl;
1086 Temp := Defining_Identifier (New_Decl);
1090 Apply_Accessibility_Check (Temp);
1092 -- Generate the tag assignment
1094 -- Suppress the tag assignment when VM_Target because VM tags are
1095 -- represented implicitly in objects.
1097 if not Tagged_Type_Expansion then
1100 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
1101 -- interface objects because in this case the tag does not change.
1103 elsif Is_Interface (Directly_Designated_Type (Etype (N))) then
1104 pragma Assert (Is_Class_Wide_Type
1105 (Directly_Designated_Type (Etype (N))));
1108 elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then
1110 TagR := New_Reference_To (Temp, Loc);
1112 elsif Is_Private_Type (T)
1113 and then Is_Tagged_Type (Underlying_Type (T))
1115 TagT := Underlying_Type (T);
1117 Unchecked_Convert_To (Underlying_Type (T),
1118 Make_Explicit_Dereference (Loc,
1119 Prefix => New_Reference_To (Temp, Loc)));
1122 if Present (TagT) then
1124 Full_T : constant Entity_Id := Underlying_Type (TagT);
1127 Make_Assignment_Statement (Loc,
1129 Make_Selected_Component (Loc,
1132 New_Reference_To (First_Tag_Component (Full_T), Loc)),
1134 Unchecked_Convert_To (RTE (RE_Tag),
1137 (First_Elmt (Access_Disp_Table (Full_T))), Loc)));
1140 -- The previous assignment has to be done in any case
1142 Set_Assignment_OK (Name (Tag_Assign));
1143 Insert_Action (N, Tag_Assign);
1146 if Needs_Finalization (DesigT)
1147 and then Needs_Finalization (T)
1149 -- Generate an Adjust call if the object will be moved. In Ada
1150 -- 2005, the object may be inherently limited, in which case
1151 -- there is no Adjust procedure, and the object is built in
1152 -- place. In Ada 95, the object can be limited but not
1153 -- inherently limited if this allocator came from a return
1154 -- statement (we're allocating the result on the secondary
1155 -- stack). In that case, the object will be moved, so we _do_
1158 if not Aggr_In_Place
1159 and then not Is_Immutably_Limited_Type (T)
1165 -- An unchecked conversion is needed in the classwide
1166 -- case because the designated type can be an ancestor
1167 -- of the subtype mark of the allocator.
1169 Unchecked_Convert_To (T,
1170 Make_Explicit_Dereference (Loc,
1171 Prefix => New_Reference_To (Temp, Loc))),
1176 -- Set_Finalize_Address (<PtrT>FM, <T>FD'Unrestricted_Access);
1178 -- Do not generate this call in the following cases:
1180 -- * .NET/JVM - these targets do not support address arithmetic
1181 -- and unchecked conversion, key elements of Finalize_Address.
1183 -- * Alfa mode - the call is useless and results in unwanted
1186 -- * CodePeer mode - TSS primitive Finalize_Address is not
1187 -- created in this mode.
1189 if VM_Target = No_VM
1190 and then not Alfa_Mode
1191 and then not CodePeer_Mode
1192 and then Present (Finalization_Master (PtrT))
1193 and then Present (Temp_Decl)
1194 and then Nkind (Expression (Temp_Decl)) = N_Allocator
1197 Make_Set_Finalize_Address_Call
1204 Rewrite (N, New_Reference_To (Temp, Loc));
1205 Analyze_And_Resolve (N, PtrT);
1207 -- Ada 2005 (AI-251): Displace the pointer to reference the record
1208 -- component containing the secondary dispatch table of the interface
1211 if Is_Interface (Directly_Designated_Type (PtrT)) then
1212 Displace_Allocator_Pointer (N);
1215 elsif Aggr_In_Place then
1216 Temp := Make_Temporary (Loc, 'P', N);
1218 Make_Object_Declaration (Loc,
1219 Defining_Identifier => Temp,
1220 Object_Definition => New_Reference_To (PtrT, Loc),
1222 Make_Allocator (Loc,
1223 Expression => New_Reference_To (Etype (Exp), Loc)));
1225 -- Copy the Comes_From_Source flag for the allocator we just built,
1226 -- since logically this allocator is a replacement of the original
1227 -- allocator node. This is for proper handling of restriction
1228 -- No_Implicit_Heap_Allocations.
1230 Set_Comes_From_Source
1231 (Expression (Temp_Decl), Comes_From_Source (N));
1233 Set_No_Initialization (Expression (Temp_Decl));
1234 Insert_Action (N, Temp_Decl);
1236 Build_Allocate_Deallocate_Proc (Temp_Decl, True);
1237 Convert_Aggr_In_Allocator (N, Temp_Decl, Exp);
1239 -- Attach the object to the associated finalization master. Thisis
1240 -- done manually on .NET/JVM since those compilers do no support
1241 -- pools and cannot benefit from internally generated Allocate and
1242 -- Deallocate procedures.
1244 if VM_Target /= No_VM
1245 and then Is_Controlled (DesigT)
1246 and then Present (Finalization_Master (PtrT))
1250 (Obj_Ref => New_Reference_To (Temp, Loc),
1254 Rewrite (N, New_Reference_To (Temp, Loc));
1255 Analyze_And_Resolve (N, PtrT);
1257 elsif Is_Access_Type (T)
1258 and then Can_Never_Be_Null (T)
1260 Install_Null_Excluding_Check (Exp);
1262 elsif Is_Access_Type (DesigT)
1263 and then Nkind (Exp) = N_Allocator
1264 and then Nkind (Expression (Exp)) /= N_Qualified_Expression
1266 -- Apply constraint to designated subtype indication
1268 Apply_Constraint_Check (Expression (Exp),
1269 Designated_Type (DesigT),
1270 No_Sliding => True);
1272 if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then
1274 -- Propagate constraint_error to enclosing allocator
1276 Rewrite (Exp, New_Copy (Expression (Exp)));
1280 Build_Allocate_Deallocate_Proc (N, True);
1283 -- type A is access T1;
1284 -- X : A := new T2'(...);
1285 -- T1 and T2 can be different subtypes, and we might need to check
1286 -- both constraints. First check against the type of the qualified
1289 Apply_Constraint_Check (Exp, T, No_Sliding => True);
1291 if Do_Range_Check (Exp) then
1292 Set_Do_Range_Check (Exp, False);
1293 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1296 -- A check is also needed in cases where the designated subtype is
1297 -- constrained and differs from the subtype given in the qualified
1298 -- expression. Note that the check on the qualified expression does
1299 -- not allow sliding, but this check does (a relaxation from Ada 83).
1301 if Is_Constrained (DesigT)
1302 and then not Subtypes_Statically_Match (T, DesigT)
1304 Apply_Constraint_Check
1305 (Exp, DesigT, No_Sliding => False);
1307 if Do_Range_Check (Exp) then
1308 Set_Do_Range_Check (Exp, False);
1309 Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed);
1313 -- For an access to unconstrained packed array, GIGI needs to see an
1314 -- expression with a constrained subtype in order to compute the
1315 -- proper size for the allocator.
1317 if Is_Array_Type (T)
1318 and then not Is_Constrained (T)
1319 and then Is_Packed (T)
1322 ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A');
1323 Internal_Exp : constant Node_Id := Relocate_Node (Exp);
1326 Make_Subtype_Declaration (Loc,
1327 Defining_Identifier => ConstrT,
1328 Subtype_Indication =>
1329 Make_Subtype_From_Expr (Internal_Exp, T)));
1330 Freeze_Itype (ConstrT, Exp);
1331 Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp));
1335 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1336 -- to a build-in-place function, then access to the allocated object
1337 -- must be passed to the function. Currently we limit such functions
1338 -- to those with constrained limited result subtypes, but eventually
1339 -- we plan to expand the allowed forms of functions that are treated
1340 -- as build-in-place.
1342 if Ada_Version >= Ada_2005
1343 and then Is_Build_In_Place_Function_Call (Exp)
1345 Make_Build_In_Place_Call_In_Allocator (N, Exp);
1350 when RE_Not_Available =>
1352 end Expand_Allocator_Expression;
1354 -----------------------------
1355 -- Expand_Array_Comparison --
1356 -----------------------------
1358 -- Expansion is only required in the case of array types. For the unpacked
1359 -- case, an appropriate runtime routine is called. For packed cases, and
1360 -- also in some other cases where a runtime routine cannot be called, the
1361 -- form of the expansion is:
1363 -- [body for greater_nn; boolean_expression]
1365 -- The body is built by Make_Array_Comparison_Op, and the form of the
1366 -- Boolean expression depends on the operator involved.
1368 procedure Expand_Array_Comparison (N : Node_Id) is
1369 Loc : constant Source_Ptr := Sloc (N);
1370 Op1 : Node_Id := Left_Opnd (N);
1371 Op2 : Node_Id := Right_Opnd (N);
1372 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
1373 Ctyp : constant Entity_Id := Component_Type (Typ1);
1376 Func_Body : Node_Id;
1377 Func_Name : Entity_Id;
1381 Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size;
1382 -- True for byte addressable target
1384 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean;
1385 -- Returns True if the length of the given operand is known to be less
1386 -- than 4. Returns False if this length is known to be four or greater
1387 -- or is not known at compile time.
1389 ------------------------
1390 -- Length_Less_Than_4 --
1391 ------------------------
1393 function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is
1394 Otyp : constant Entity_Id := Etype (Opnd);
1397 if Ekind (Otyp) = E_String_Literal_Subtype then
1398 return String_Literal_Length (Otyp) < 4;
1402 Ityp : constant Entity_Id := Etype (First_Index (Otyp));
1403 Lo : constant Node_Id := Type_Low_Bound (Ityp);
1404 Hi : constant Node_Id := Type_High_Bound (Ityp);
1409 if Compile_Time_Known_Value (Lo) then
1410 Lov := Expr_Value (Lo);
1415 if Compile_Time_Known_Value (Hi) then
1416 Hiv := Expr_Value (Hi);
1421 return Hiv < Lov + 3;
1424 end Length_Less_Than_4;
1426 -- Start of processing for Expand_Array_Comparison
1429 -- Deal first with unpacked case, where we can call a runtime routine
1430 -- except that we avoid this for targets for which are not addressable
1431 -- by bytes, and for the JVM/CIL, since they do not support direct
1432 -- addressing of array components.
1434 if not Is_Bit_Packed_Array (Typ1)
1435 and then Byte_Addressable
1436 and then VM_Target = No_VM
1438 -- The call we generate is:
1440 -- Compare_Array_xn[_Unaligned]
1441 -- (left'address, right'address, left'length, right'length) <op> 0
1443 -- x = U for unsigned, S for signed
1444 -- n = 8,16,32,64 for component size
1445 -- Add _Unaligned if length < 4 and component size is 8.
1446 -- <op> is the standard comparison operator
1448 if Component_Size (Typ1) = 8 then
1449 if Length_Less_Than_4 (Op1)
1451 Length_Less_Than_4 (Op2)
1453 if Is_Unsigned_Type (Ctyp) then
1454 Comp := RE_Compare_Array_U8_Unaligned;
1456 Comp := RE_Compare_Array_S8_Unaligned;
1460 if Is_Unsigned_Type (Ctyp) then
1461 Comp := RE_Compare_Array_U8;
1463 Comp := RE_Compare_Array_S8;
1467 elsif Component_Size (Typ1) = 16 then
1468 if Is_Unsigned_Type (Ctyp) then
1469 Comp := RE_Compare_Array_U16;
1471 Comp := RE_Compare_Array_S16;
1474 elsif Component_Size (Typ1) = 32 then
1475 if Is_Unsigned_Type (Ctyp) then
1476 Comp := RE_Compare_Array_U32;
1478 Comp := RE_Compare_Array_S32;
1481 else pragma Assert (Component_Size (Typ1) = 64);
1482 if Is_Unsigned_Type (Ctyp) then
1483 Comp := RE_Compare_Array_U64;
1485 Comp := RE_Compare_Array_S64;
1489 Remove_Side_Effects (Op1, Name_Req => True);
1490 Remove_Side_Effects (Op2, Name_Req => True);
1493 Make_Function_Call (Sloc (Op1),
1494 Name => New_Occurrence_Of (RTE (Comp), Loc),
1496 Parameter_Associations => New_List (
1497 Make_Attribute_Reference (Loc,
1498 Prefix => Relocate_Node (Op1),
1499 Attribute_Name => Name_Address),
1501 Make_Attribute_Reference (Loc,
1502 Prefix => Relocate_Node (Op2),
1503 Attribute_Name => Name_Address),
1505 Make_Attribute_Reference (Loc,
1506 Prefix => Relocate_Node (Op1),
1507 Attribute_Name => Name_Length),
1509 Make_Attribute_Reference (Loc,
1510 Prefix => Relocate_Node (Op2),
1511 Attribute_Name => Name_Length))));
1514 Make_Integer_Literal (Sloc (Op2),
1517 Analyze_And_Resolve (Op1, Standard_Integer);
1518 Analyze_And_Resolve (Op2, Standard_Integer);
1522 -- Cases where we cannot make runtime call
1524 -- For (a <= b) we convert to not (a > b)
1526 if Chars (N) = Name_Op_Le then
1532 Right_Opnd => Op2)));
1533 Analyze_And_Resolve (N, Standard_Boolean);
1536 -- For < the Boolean expression is
1537 -- greater__nn (op2, op1)
1539 elsif Chars (N) = Name_Op_Lt then
1540 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1544 Op1 := Right_Opnd (N);
1545 Op2 := Left_Opnd (N);
1547 -- For (a >= b) we convert to not (a < b)
1549 elsif Chars (N) = Name_Op_Ge then
1555 Right_Opnd => Op2)));
1556 Analyze_And_Resolve (N, Standard_Boolean);
1559 -- For > the Boolean expression is
1560 -- greater__nn (op1, op2)
1563 pragma Assert (Chars (N) = Name_Op_Gt);
1564 Func_Body := Make_Array_Comparison_Op (Typ1, N);
1567 Func_Name := Defining_Unit_Name (Specification (Func_Body));
1569 Make_Function_Call (Loc,
1570 Name => New_Reference_To (Func_Name, Loc),
1571 Parameter_Associations => New_List (Op1, Op2));
1573 Insert_Action (N, Func_Body);
1575 Analyze_And_Resolve (N, Standard_Boolean);
1578 when RE_Not_Available =>
1580 end Expand_Array_Comparison;
1582 ---------------------------
1583 -- Expand_Array_Equality --
1584 ---------------------------
1586 -- Expand an equality function for multi-dimensional arrays. Here is an
1587 -- example of such a function for Nb_Dimension = 2
1589 -- function Enn (A : atyp; B : btyp) return boolean is
1591 -- if (A'length (1) = 0 or else A'length (2) = 0)
1593 -- (B'length (1) = 0 or else B'length (2) = 0)
1595 -- return True; -- RM 4.5.2(22)
1598 -- if A'length (1) /= B'length (1)
1600 -- A'length (2) /= B'length (2)
1602 -- return False; -- RM 4.5.2(23)
1606 -- A1 : Index_T1 := A'first (1);
1607 -- B1 : Index_T1 := B'first (1);
1611 -- A2 : Index_T2 := A'first (2);
1612 -- B2 : Index_T2 := B'first (2);
1615 -- if A (A1, A2) /= B (B1, B2) then
1619 -- exit when A2 = A'last (2);
1620 -- A2 := Index_T2'succ (A2);
1621 -- B2 := Index_T2'succ (B2);
1625 -- exit when A1 = A'last (1);
1626 -- A1 := Index_T1'succ (A1);
1627 -- B1 := Index_T1'succ (B1);
1634 -- Note on the formal types used (atyp and btyp). If either of the arrays
1635 -- is of a private type, we use the underlying type, and do an unchecked
1636 -- conversion of the actual. If either of the arrays has a bound depending
1637 -- on a discriminant, then we use the base type since otherwise we have an
1638 -- escaped discriminant in the function.
1640 -- If both arrays are constrained and have the same bounds, we can generate
1641 -- a loop with an explicit iteration scheme using a 'Range attribute over
1644 function Expand_Array_Equality
1649 Typ : Entity_Id) return Node_Id
1651 Loc : constant Source_Ptr := Sloc (Nod);
1652 Decls : constant List_Id := New_List;
1653 Index_List1 : constant List_Id := New_List;
1654 Index_List2 : constant List_Id := New_List;
1658 Func_Name : Entity_Id;
1659 Func_Body : Node_Id;
1661 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
1662 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
1666 -- The parameter types to be used for the formals
1671 Num : Int) return Node_Id;
1672 -- This builds the attribute reference Arr'Nam (Expr)
1674 function Component_Equality (Typ : Entity_Id) return Node_Id;
1675 -- Create one statement to compare corresponding components, designated
1676 -- by a full set of indexes.
1678 function Get_Arg_Type (N : Node_Id) return Entity_Id;
1679 -- Given one of the arguments, computes the appropriate type to be used
1680 -- for that argument in the corresponding function formal
1682 function Handle_One_Dimension
1684 Index : Node_Id) return Node_Id;
1685 -- This procedure returns the following code
1688 -- Bn : Index_T := B'First (N);
1692 -- exit when An = A'Last (N);
1693 -- An := Index_T'Succ (An)
1694 -- Bn := Index_T'Succ (Bn)
1698 -- If both indexes are constrained and identical, the procedure
1699 -- returns a simpler loop:
1701 -- for An in A'Range (N) loop
1705 -- N is the dimension for which we are generating a loop. Index is the
1706 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1707 -- xxx statement is either the loop or declare for the next dimension
1708 -- or if this is the last dimension the comparison of corresponding
1709 -- components of the arrays.
1711 -- The actual way the code works is to return the comparison of
1712 -- corresponding components for the N+1 call. That's neater!
1714 function Test_Empty_Arrays return Node_Id;
1715 -- This function constructs the test for both arrays being empty
1716 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1718 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1720 function Test_Lengths_Correspond return Node_Id;
1721 -- This function constructs the test for arrays having different lengths
1722 -- in at least one index position, in which case the resulting code is:
1724 -- A'length (1) /= B'length (1)
1726 -- A'length (2) /= B'length (2)
1737 Num : Int) return Node_Id
1741 Make_Attribute_Reference (Loc,
1742 Attribute_Name => Nam,
1743 Prefix => New_Reference_To (Arr, Loc),
1744 Expressions => New_List (Make_Integer_Literal (Loc, Num)));
1747 ------------------------
1748 -- Component_Equality --
1749 ------------------------
1751 function Component_Equality (Typ : Entity_Id) return Node_Id is
1756 -- if a(i1...) /= b(j1...) then return false; end if;
1759 Make_Indexed_Component (Loc,
1760 Prefix => Make_Identifier (Loc, Chars (A)),
1761 Expressions => Index_List1);
1764 Make_Indexed_Component (Loc,
1765 Prefix => Make_Identifier (Loc, Chars (B)),
1766 Expressions => Index_List2);
1768 Test := Expand_Composite_Equality
1769 (Nod, Component_Type (Typ), L, R, Decls);
1771 -- If some (sub)component is an unchecked_union, the whole operation
1772 -- will raise program error.
1774 if Nkind (Test) = N_Raise_Program_Error then
1776 -- This node is going to be inserted at a location where a
1777 -- statement is expected: clear its Etype so analysis will set
1778 -- it to the expected Standard_Void_Type.
1780 Set_Etype (Test, Empty);
1785 Make_Implicit_If_Statement (Nod,
1786 Condition => Make_Op_Not (Loc, Right_Opnd => Test),
1787 Then_Statements => New_List (
1788 Make_Simple_Return_Statement (Loc,
1789 Expression => New_Occurrence_Of (Standard_False, Loc))));
1791 end Component_Equality;
1797 function Get_Arg_Type (N : Node_Id) return Entity_Id is
1808 T := Underlying_Type (T);
1810 X := First_Index (T);
1811 while Present (X) loop
1812 if Denotes_Discriminant (Type_Low_Bound (Etype (X)))
1814 Denotes_Discriminant (Type_High_Bound (Etype (X)))
1827 --------------------------
1828 -- Handle_One_Dimension --
1829 ---------------------------
1831 function Handle_One_Dimension
1833 Index : Node_Id) return Node_Id
1835 Need_Separate_Indexes : constant Boolean :=
1837 or else not Is_Constrained (Ltyp);
1838 -- If the index types are identical, and we are working with
1839 -- constrained types, then we can use the same index for both
1842 An : constant Entity_Id := Make_Temporary (Loc, 'A');
1845 Index_T : Entity_Id;
1850 if N > Number_Dimensions (Ltyp) then
1851 return Component_Equality (Ltyp);
1854 -- Case where we generate a loop
1856 Index_T := Base_Type (Etype (Index));
1858 if Need_Separate_Indexes then
1859 Bn := Make_Temporary (Loc, 'B');
1864 Append (New_Reference_To (An, Loc), Index_List1);
1865 Append (New_Reference_To (Bn, Loc), Index_List2);
1867 Stm_List := New_List (
1868 Handle_One_Dimension (N + 1, Next_Index (Index)));
1870 if Need_Separate_Indexes then
1872 -- Generate guard for loop, followed by increments of indexes
1874 Append_To (Stm_List,
1875 Make_Exit_Statement (Loc,
1878 Left_Opnd => New_Reference_To (An, Loc),
1879 Right_Opnd => Arr_Attr (A, Name_Last, N))));
1881 Append_To (Stm_List,
1882 Make_Assignment_Statement (Loc,
1883 Name => New_Reference_To (An, Loc),
1885 Make_Attribute_Reference (Loc,
1886 Prefix => New_Reference_To (Index_T, Loc),
1887 Attribute_Name => Name_Succ,
1888 Expressions => New_List (New_Reference_To (An, Loc)))));
1890 Append_To (Stm_List,
1891 Make_Assignment_Statement (Loc,
1892 Name => New_Reference_To (Bn, Loc),
1894 Make_Attribute_Reference (Loc,
1895 Prefix => New_Reference_To (Index_T, Loc),
1896 Attribute_Name => Name_Succ,
1897 Expressions => New_List (New_Reference_To (Bn, Loc)))));
1900 -- If separate indexes, we need a declare block for An and Bn, and a
1901 -- loop without an iteration scheme.
1903 if Need_Separate_Indexes then
1905 Make_Implicit_Loop_Statement (Nod, Statements => Stm_List);
1908 Make_Block_Statement (Loc,
1909 Declarations => New_List (
1910 Make_Object_Declaration (Loc,
1911 Defining_Identifier => An,
1912 Object_Definition => New_Reference_To (Index_T, Loc),
1913 Expression => Arr_Attr (A, Name_First, N)),
1915 Make_Object_Declaration (Loc,
1916 Defining_Identifier => Bn,
1917 Object_Definition => New_Reference_To (Index_T, Loc),
1918 Expression => Arr_Attr (B, Name_First, N))),
1920 Handled_Statement_Sequence =>
1921 Make_Handled_Sequence_Of_Statements (Loc,
1922 Statements => New_List (Loop_Stm)));
1924 -- If no separate indexes, return loop statement with explicit
1925 -- iteration scheme on its own
1929 Make_Implicit_Loop_Statement (Nod,
1930 Statements => Stm_List,
1932 Make_Iteration_Scheme (Loc,
1933 Loop_Parameter_Specification =>
1934 Make_Loop_Parameter_Specification (Loc,
1935 Defining_Identifier => An,
1936 Discrete_Subtype_Definition =>
1937 Arr_Attr (A, Name_Range, N))));
1940 end Handle_One_Dimension;
1942 -----------------------
1943 -- Test_Empty_Arrays --
1944 -----------------------
1946 function Test_Empty_Arrays return Node_Id is
1956 for J in 1 .. Number_Dimensions (Ltyp) loop
1959 Left_Opnd => Arr_Attr (A, Name_Length, J),
1960 Right_Opnd => Make_Integer_Literal (Loc, 0));
1964 Left_Opnd => Arr_Attr (B, Name_Length, J),
1965 Right_Opnd => Make_Integer_Literal (Loc, 0));
1974 Left_Opnd => Relocate_Node (Alist),
1975 Right_Opnd => Atest);
1979 Left_Opnd => Relocate_Node (Blist),
1980 Right_Opnd => Btest);
1987 Right_Opnd => Blist);
1988 end Test_Empty_Arrays;
1990 -----------------------------
1991 -- Test_Lengths_Correspond --
1992 -----------------------------
1994 function Test_Lengths_Correspond return Node_Id is
2000 for J in 1 .. Number_Dimensions (Ltyp) loop
2003 Left_Opnd => Arr_Attr (A, Name_Length, J),
2004 Right_Opnd => Arr_Attr (B, Name_Length, J));
2011 Left_Opnd => Relocate_Node (Result),
2012 Right_Opnd => Rtest);
2017 end Test_Lengths_Correspond;
2019 -- Start of processing for Expand_Array_Equality
2022 Ltyp := Get_Arg_Type (Lhs);
2023 Rtyp := Get_Arg_Type (Rhs);
2025 -- For now, if the argument types are not the same, go to the base type,
2026 -- since the code assumes that the formals have the same type. This is
2027 -- fixable in future ???
2029 if Ltyp /= Rtyp then
2030 Ltyp := Base_Type (Ltyp);
2031 Rtyp := Base_Type (Rtyp);
2032 pragma Assert (Ltyp = Rtyp);
2035 -- Build list of formals for function
2037 Formals := New_List (
2038 Make_Parameter_Specification (Loc,
2039 Defining_Identifier => A,
2040 Parameter_Type => New_Reference_To (Ltyp, Loc)),
2042 Make_Parameter_Specification (Loc,
2043 Defining_Identifier => B,
2044 Parameter_Type => New_Reference_To (Rtyp, Loc)));
2046 Func_Name := Make_Temporary (Loc, 'E');
2048 -- Build statement sequence for function
2051 Make_Subprogram_Body (Loc,
2053 Make_Function_Specification (Loc,
2054 Defining_Unit_Name => Func_Name,
2055 Parameter_Specifications => Formals,
2056 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
2058 Declarations => Decls,
2060 Handled_Statement_Sequence =>
2061 Make_Handled_Sequence_Of_Statements (Loc,
2062 Statements => New_List (
2064 Make_Implicit_If_Statement (Nod,
2065 Condition => Test_Empty_Arrays,
2066 Then_Statements => New_List (
2067 Make_Simple_Return_Statement (Loc,
2069 New_Occurrence_Of (Standard_True, Loc)))),
2071 Make_Implicit_If_Statement (Nod,
2072 Condition => Test_Lengths_Correspond,
2073 Then_Statements => New_List (
2074 Make_Simple_Return_Statement (Loc,
2076 New_Occurrence_Of (Standard_False, Loc)))),
2078 Handle_One_Dimension (1, First_Index (Ltyp)),
2080 Make_Simple_Return_Statement (Loc,
2081 Expression => New_Occurrence_Of (Standard_True, Loc)))));
2083 Set_Has_Completion (Func_Name, True);
2084 Set_Is_Inlined (Func_Name);
2086 -- If the array type is distinct from the type of the arguments, it
2087 -- is the full view of a private type. Apply an unchecked conversion
2088 -- to insure that analysis of the call succeeds.
2098 or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp)
2100 L := OK_Convert_To (Ltyp, Lhs);
2104 or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp)
2106 R := OK_Convert_To (Rtyp, Rhs);
2109 Actuals := New_List (L, R);
2112 Append_To (Bodies, Func_Body);
2115 Make_Function_Call (Loc,
2116 Name => New_Reference_To (Func_Name, Loc),
2117 Parameter_Associations => Actuals);
2118 end Expand_Array_Equality;
2120 -----------------------------
2121 -- Expand_Boolean_Operator --
2122 -----------------------------
2124 -- Note that we first get the actual subtypes of the operands, since we
2125 -- always want to deal with types that have bounds.
2127 procedure Expand_Boolean_Operator (N : Node_Id) is
2128 Typ : constant Entity_Id := Etype (N);
2131 -- Special case of bit packed array where both operands are known to be
2132 -- properly aligned. In this case we use an efficient run time routine
2133 -- to carry out the operation (see System.Bit_Ops).
2135 if Is_Bit_Packed_Array (Typ)
2136 and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
2137 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
2139 Expand_Packed_Boolean_Operator (N);
2143 -- For the normal non-packed case, the general expansion is to build
2144 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
2145 -- and then inserting it into the tree. The original operator node is
2146 -- then rewritten as a call to this function. We also use this in the
2147 -- packed case if either operand is a possibly unaligned object.
2150 Loc : constant Source_Ptr := Sloc (N);
2151 L : constant Node_Id := Relocate_Node (Left_Opnd (N));
2152 R : constant Node_Id := Relocate_Node (Right_Opnd (N));
2153 Func_Body : Node_Id;
2154 Func_Name : Entity_Id;
2157 Convert_To_Actual_Subtype (L);
2158 Convert_To_Actual_Subtype (R);
2159 Ensure_Defined (Etype (L), N);
2160 Ensure_Defined (Etype (R), N);
2161 Apply_Length_Check (R, Etype (L));
2163 if Nkind (N) = N_Op_Xor then
2164 Silly_Boolean_Array_Xor_Test (N, Etype (L));
2167 if Nkind (Parent (N)) = N_Assignment_Statement
2168 and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
2170 Build_Boolean_Array_Proc_Call (Parent (N), L, R);
2172 elsif Nkind (Parent (N)) = N_Op_Not
2173 and then Nkind (N) = N_Op_And
2175 Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
2180 Func_Body := Make_Boolean_Array_Op (Etype (L), N);
2181 Func_Name := Defining_Unit_Name (Specification (Func_Body));
2182 Insert_Action (N, Func_Body);
2184 -- Now rewrite the expression with a call
2187 Make_Function_Call (Loc,
2188 Name => New_Reference_To (Func_Name, Loc),
2189 Parameter_Associations =>
2192 Make_Type_Conversion
2193 (Loc, New_Reference_To (Etype (L), Loc), R))));
2195 Analyze_And_Resolve (N, Typ);
2198 end Expand_Boolean_Operator;
2200 -------------------------------
2201 -- Expand_Composite_Equality --
2202 -------------------------------
2204 -- This function is only called for comparing internal fields of composite
2205 -- types when these fields are themselves composites. This is a special
2206 -- case because it is not possible to respect normal Ada visibility rules.
2208 function Expand_Composite_Equality
2213 Bodies : List_Id) return Node_Id
2215 Loc : constant Source_Ptr := Sloc (Nod);
2216 Full_Type : Entity_Id;
2220 function Find_Primitive_Eq return Node_Id;
2221 -- AI05-0123: Locate primitive equality for type if it exists, and
2222 -- build the corresponding call. If operation is abstract, replace
2223 -- call with an explicit raise. Return Empty if there is no primitive.
2225 -----------------------
2226 -- Find_Primitive_Eq --
2227 -----------------------
2229 function Find_Primitive_Eq return Node_Id is
2234 Prim_E := First_Elmt (Collect_Primitive_Operations (Typ));
2235 while Present (Prim_E) loop
2236 Prim := Node (Prim_E);
2238 -- Locate primitive equality with the right signature
2240 if Chars (Prim) = Name_Op_Eq
2241 and then Etype (First_Formal (Prim)) =
2242 Etype (Next_Formal (First_Formal (Prim)))
2243 and then Etype (Prim) = Standard_Boolean
2245 if Is_Abstract_Subprogram (Prim) then
2247 Make_Raise_Program_Error (Loc,
2248 Reason => PE_Explicit_Raise);
2252 Make_Function_Call (Loc,
2253 Name => New_Reference_To (Prim, Loc),
2254 Parameter_Associations => New_List (Lhs, Rhs));
2261 -- If not found, predefined operation will be used
2264 end Find_Primitive_Eq;
2266 -- Start of processing for Expand_Composite_Equality
2269 if Is_Private_Type (Typ) then
2270 Full_Type := Underlying_Type (Typ);
2275 -- Defense against malformed private types with no completion the error
2276 -- will be diagnosed later by check_completion
2278 if No (Full_Type) then
2279 return New_Reference_To (Standard_False, Loc);
2282 Full_Type := Base_Type (Full_Type);
2284 if Is_Array_Type (Full_Type) then
2286 -- If the operand is an elementary type other than a floating-point
2287 -- type, then we can simply use the built-in block bitwise equality,
2288 -- since the predefined equality operators always apply and bitwise
2289 -- equality is fine for all these cases.
2291 if Is_Elementary_Type (Component_Type (Full_Type))
2292 and then not Is_Floating_Point_Type (Component_Type (Full_Type))
2294 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2296 -- For composite component types, and floating-point types, use the
2297 -- expansion. This deals with tagged component types (where we use
2298 -- the applicable equality routine) and floating-point, (where we
2299 -- need to worry about negative zeroes), and also the case of any
2300 -- composite type recursively containing such fields.
2303 return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type);
2306 elsif Is_Tagged_Type (Full_Type) then
2308 -- Call the primitive operation "=" of this type
2310 if Is_Class_Wide_Type (Full_Type) then
2311 Full_Type := Root_Type (Full_Type);
2314 -- If this is derived from an untagged private type completed with a
2315 -- tagged type, it does not have a full view, so we use the primitive
2316 -- operations of the private type. This check should no longer be
2317 -- necessary when these types receive their full views ???
2319 if Is_Private_Type (Typ)
2320 and then not Is_Tagged_Type (Typ)
2321 and then not Is_Controlled (Typ)
2322 and then Is_Derived_Type (Typ)
2323 and then No (Full_View (Typ))
2325 Prim := First_Elmt (Collect_Primitive_Operations (Typ));
2327 Prim := First_Elmt (Primitive_Operations (Full_Type));
2331 Eq_Op := Node (Prim);
2332 exit when Chars (Eq_Op) = Name_Op_Eq
2333 and then Etype (First_Formal (Eq_Op)) =
2334 Etype (Next_Formal (First_Formal (Eq_Op)))
2335 and then Base_Type (Etype (Eq_Op)) = Standard_Boolean;
2337 pragma Assert (Present (Prim));
2340 Eq_Op := Node (Prim);
2343 Make_Function_Call (Loc,
2344 Name => New_Reference_To (Eq_Op, Loc),
2345 Parameter_Associations =>
2347 (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs),
2348 Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs)));
2350 elsif Is_Record_Type (Full_Type) then
2351 Eq_Op := TSS (Full_Type, TSS_Composite_Equality);
2353 if Present (Eq_Op) then
2354 if Etype (First_Formal (Eq_Op)) /= Full_Type then
2356 -- Inherited equality from parent type. Convert the actuals to
2357 -- match signature of operation.
2360 T : constant Entity_Id := Etype (First_Formal (Eq_Op));
2364 Make_Function_Call (Loc,
2365 Name => New_Reference_To (Eq_Op, Loc),
2366 Parameter_Associations => New_List (
2367 OK_Convert_To (T, Lhs),
2368 OK_Convert_To (T, Rhs)));
2372 -- Comparison between Unchecked_Union components
2374 if Is_Unchecked_Union (Full_Type) then
2376 Lhs_Type : Node_Id := Full_Type;
2377 Rhs_Type : Node_Id := Full_Type;
2378 Lhs_Discr_Val : Node_Id;
2379 Rhs_Discr_Val : Node_Id;
2384 if Nkind (Lhs) = N_Selected_Component then
2385 Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
2390 if Nkind (Rhs) = N_Selected_Component then
2391 Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
2394 -- Lhs of the composite equality
2396 if Is_Constrained (Lhs_Type) then
2398 -- Since the enclosing record type can never be an
2399 -- Unchecked_Union (this code is executed for records
2400 -- that do not have variants), we may reference its
2403 if Nkind (Lhs) = N_Selected_Component
2404 and then Has_Per_Object_Constraint (
2405 Entity (Selector_Name (Lhs)))
2408 Make_Selected_Component (Loc,
2409 Prefix => Prefix (Lhs),
2412 (Get_Discriminant_Value
2413 (First_Discriminant (Lhs_Type),
2415 Stored_Constraint (Lhs_Type))));
2420 (Get_Discriminant_Value
2421 (First_Discriminant (Lhs_Type),
2423 Stored_Constraint (Lhs_Type)));
2427 -- It is not possible to infer the discriminant since
2428 -- the subtype is not constrained.
2431 Make_Raise_Program_Error (Loc,
2432 Reason => PE_Unchecked_Union_Restriction);
2435 -- Rhs of the composite equality
2437 if Is_Constrained (Rhs_Type) then
2438 if Nkind (Rhs) = N_Selected_Component
2439 and then Has_Per_Object_Constraint
2440 (Entity (Selector_Name (Rhs)))
2443 Make_Selected_Component (Loc,
2444 Prefix => Prefix (Rhs),
2447 (Get_Discriminant_Value
2448 (First_Discriminant (Rhs_Type),
2450 Stored_Constraint (Rhs_Type))));
2455 (Get_Discriminant_Value
2456 (First_Discriminant (Rhs_Type),
2458 Stored_Constraint (Rhs_Type)));
2463 Make_Raise_Program_Error (Loc,
2464 Reason => PE_Unchecked_Union_Restriction);
2467 -- Call the TSS equality function with the inferred
2468 -- discriminant values.
2471 Make_Function_Call (Loc,
2472 Name => New_Reference_To (Eq_Op, Loc),
2473 Parameter_Associations => New_List (
2482 Make_Function_Call (Loc,
2483 Name => New_Reference_To (Eq_Op, Loc),
2484 Parameter_Associations => New_List (Lhs, Rhs));
2488 elsif Ada_Version >= Ada_2012 then
2490 -- if no TSS has been created for the type, check whether there is
2491 -- a primitive equality declared for it.
2494 Ada_2012_Op : constant Node_Id := Find_Primitive_Eq;
2497 if Present (Ada_2012_Op) then
2501 -- Use predefined equality if no user-defined primitive exists
2503 return Make_Op_Eq (Loc, Lhs, Rhs);
2508 return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
2512 -- If not array or record type, it is predefined equality.
2514 return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
2516 end Expand_Composite_Equality;
2518 ------------------------
2519 -- Expand_Concatenate --
2520 ------------------------
2522 procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is
2523 Loc : constant Source_Ptr := Sloc (Cnode);
2525 Atyp : constant Entity_Id := Base_Type (Etype (Cnode));
2526 -- Result type of concatenation
2528 Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode)));
2529 -- Component type. Elements of this component type can appear as one
2530 -- of the operands of concatenation as well as arrays.
2532 Istyp : constant Entity_Id := Etype (First_Index (Atyp));
2535 Ityp : constant Entity_Id := Base_Type (Istyp);
2536 -- Index type. This is the base type of the index subtype, and is used
2537 -- for all computed bounds (which may be out of range of Istyp in the
2538 -- case of null ranges).
2541 -- This is the type we use to do arithmetic to compute the bounds and
2542 -- lengths of operands. The choice of this type is a little subtle and
2543 -- is discussed in a separate section at the start of the body code.
2545 Concatenation_Error : exception;
2546 -- Raised if concatenation is sure to raise a CE
2548 Result_May_Be_Null : Boolean := True;
2549 -- Reset to False if at least one operand is encountered which is known
2550 -- at compile time to be non-null. Used for handling the special case
2551 -- of setting the high bound to the last operand high bound for a null
2552 -- result, thus ensuring a proper high bound in the super-flat case.
2554 N : constant Nat := List_Length (Opnds);
2555 -- Number of concatenation operands including possibly null operands
2558 -- Number of operands excluding any known to be null, except that the
2559 -- last operand is always retained, in case it provides the bounds for
2563 -- Current operand being processed in the loop through operands. After
2564 -- this loop is complete, always contains the last operand (which is not
2565 -- the same as Operands (NN), since null operands are skipped).
2567 -- Arrays describing the operands, only the first NN entries of each
2568 -- array are set (NN < N when we exclude known null operands).
2570 Is_Fixed_Length : array (1 .. N) of Boolean;
2571 -- True if length of corresponding operand known at compile time
2573 Operands : array (1 .. N) of Node_Id;
2574 -- Set to the corresponding entry in the Opnds list (but note that null
2575 -- operands are excluded, so not all entries in the list are stored).
2577 Fixed_Length : array (1 .. N) of Uint;
2578 -- Set to length of operand. Entries in this array are set only if the
2579 -- corresponding entry in Is_Fixed_Length is True.
2581 Opnd_Low_Bound : array (1 .. N) of Node_Id;
2582 -- Set to lower bound of operand. Either an integer literal in the case
2583 -- where the bound is known at compile time, else actual lower bound.
2584 -- The operand low bound is of type Ityp.
2586 Var_Length : array (1 .. N) of Entity_Id;
2587 -- Set to an entity of type Natural that contains the length of an
2588 -- operand whose length is not known at compile time. Entries in this
2589 -- array are set only if the corresponding entry in Is_Fixed_Length
2590 -- is False. The entity is of type Artyp.
2592 Aggr_Length : array (0 .. N) of Node_Id;
2593 -- The J'th entry in an expression node that represents the total length
2594 -- of operands 1 through J. It is either an integer literal node, or a
2595 -- reference to a constant entity with the right value, so it is fine
2596 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2597 -- entry always is set to zero. The length is of type Artyp.
2599 Low_Bound : Node_Id;
2600 -- A tree node representing the low bound of the result (of type Ityp).
2601 -- This is either an integer literal node, or an identifier reference to
2602 -- a constant entity initialized to the appropriate value.
2604 Last_Opnd_High_Bound : Node_Id;
2605 -- A tree node representing the high bound of the last operand. This
2606 -- need only be set if the result could be null. It is used for the
2607 -- special case of setting the right high bound for a null result.
2608 -- This is of type Ityp.
2610 High_Bound : Node_Id;
2611 -- A tree node representing the high bound of the result (of type Ityp)
2614 -- Result of the concatenation (of type Ityp)
2616 Actions : constant List_Id := New_List;
2617 -- Collect actions to be inserted
2619 Known_Non_Null_Operand_Seen : Boolean;
2620 -- Set True during generation of the assignments of operands into
2621 -- result once an operand known to be non-null has been seen.
2623 function Make_Artyp_Literal (Val : Nat) return Node_Id;
2624 -- This function makes an N_Integer_Literal node that is returned in
2625 -- analyzed form with the type set to Artyp. Importantly this literal
2626 -- is not flagged as static, so that if we do computations with it that
2627 -- result in statically detected out of range conditions, we will not
2628 -- generate error messages but instead warning messages.
2630 function To_Artyp (X : Node_Id) return Node_Id;
2631 -- Given a node of type Ityp, returns the corresponding value of type
2632 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2633 -- For enum types, the Pos of the value is returned.
2635 function To_Ityp (X : Node_Id) return Node_Id;
2636 -- The inverse function (uses Val in the case of enumeration types)
2638 ------------------------
2639 -- Make_Artyp_Literal --
2640 ------------------------
2642 function Make_Artyp_Literal (Val : Nat) return Node_Id is
2643 Result : constant Node_Id := Make_Integer_Literal (Loc, Val);
2645 Set_Etype (Result, Artyp);
2646 Set_Analyzed (Result, True);
2647 Set_Is_Static_Expression (Result, False);
2649 end Make_Artyp_Literal;
2655 function To_Artyp (X : Node_Id) return Node_Id is
2657 if Ityp = Base_Type (Artyp) then
2660 elsif Is_Enumeration_Type (Ityp) then
2662 Make_Attribute_Reference (Loc,
2663 Prefix => New_Occurrence_Of (Ityp, Loc),
2664 Attribute_Name => Name_Pos,
2665 Expressions => New_List (X));
2668 return Convert_To (Artyp, X);
2676 function To_Ityp (X : Node_Id) return Node_Id is
2678 if Is_Enumeration_Type (Ityp) then
2680 Make_Attribute_Reference (Loc,
2681 Prefix => New_Occurrence_Of (Ityp, Loc),
2682 Attribute_Name => Name_Val,
2683 Expressions => New_List (X));
2685 -- Case where we will do a type conversion
2688 if Ityp = Base_Type (Artyp) then
2691 return Convert_To (Ityp, X);
2696 -- Local Declarations
2698 Opnd_Typ : Entity_Id;
2705 -- Start of processing for Expand_Concatenate
2708 -- Choose an appropriate computational type
2710 -- We will be doing calculations of lengths and bounds in this routine
2711 -- and computing one from the other in some cases, e.g. getting the high
2712 -- bound by adding the length-1 to the low bound.
2714 -- We can't just use the index type, or even its base type for this
2715 -- purpose for two reasons. First it might be an enumeration type which
2716 -- is not suitable for computations of any kind, and second it may
2717 -- simply not have enough range. For example if the index type is
2718 -- -128..+127 then lengths can be up to 256, which is out of range of
2721 -- For enumeration types, we can simply use Standard_Integer, this is
2722 -- sufficient since the actual number of enumeration literals cannot
2723 -- possibly exceed the range of integer (remember we will be doing the
2724 -- arithmetic with POS values, not representation values).
2726 if Is_Enumeration_Type (Ityp) then
2727 Artyp := Standard_Integer;
2729 -- If index type is Positive, we use the standard unsigned type, to give
2730 -- more room on the top of the range, obviating the need for an overflow
2731 -- check when creating the upper bound. This is needed to avoid junk
2732 -- overflow checks in the common case of String types.
2734 -- ??? Disabled for now
2736 -- elsif Istyp = Standard_Positive then
2737 -- Artyp := Standard_Unsigned;
2739 -- For modular types, we use a 32-bit modular type for types whose size
2740 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2741 -- identity type, and for larger unsigned types we use 64-bits.
2743 elsif Is_Modular_Integer_Type (Ityp) then
2744 if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
2745 Artyp := Standard_Unsigned;
2746 elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
2749 Artyp := RTE (RE_Long_Long_Unsigned);
2752 -- Similar treatment for signed types
2755 if RM_Size (Ityp) < RM_Size (Standard_Integer) then
2756 Artyp := Standard_Integer;
2757 elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
2760 Artyp := Standard_Long_Long_Integer;
2764 -- Supply dummy entry at start of length array
2766 Aggr_Length (0) := Make_Artyp_Literal (0);
2768 -- Go through operands setting up the above arrays
2772 Opnd := Remove_Head (Opnds);
2773 Opnd_Typ := Etype (Opnd);
2775 -- The parent got messed up when we put the operands in a list,
2776 -- so now put back the proper parent for the saved operand, that
2777 -- is to say the concatenation node, to make sure that each operand
2778 -- is seen as a subexpression, e.g. if actions must be inserted.
2780 Set_Parent (Opnd, Cnode);
2782 -- Set will be True when we have setup one entry in the array
2786 -- Singleton element (or character literal) case
2788 if Base_Type (Opnd_Typ) = Ctyp then
2790 Operands (NN) := Opnd;
2791 Is_Fixed_Length (NN) := True;
2792 Fixed_Length (NN) := Uint_1;
2793 Result_May_Be_Null := False;
2795 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2796 -- since we know that the result cannot be null).
2798 Opnd_Low_Bound (NN) :=
2799 Make_Attribute_Reference (Loc,
2800 Prefix => New_Reference_To (Istyp, Loc),
2801 Attribute_Name => Name_First);
2805 -- String literal case (can only occur for strings of course)
2807 elsif Nkind (Opnd) = N_String_Literal then
2808 Len := String_Literal_Length (Opnd_Typ);
2811 Result_May_Be_Null := False;
2814 -- Capture last operand high bound if result could be null
2816 if J = N and then Result_May_Be_Null then
2817 Last_Opnd_High_Bound :=
2820 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)),
2821 Right_Opnd => Make_Integer_Literal (Loc, 1));
2824 -- Skip null string literal
2826 if J < N and then Len = 0 then
2831 Operands (NN) := Opnd;
2832 Is_Fixed_Length (NN) := True;
2834 -- Set length and bounds
2836 Fixed_Length (NN) := Len;
2838 Opnd_Low_Bound (NN) :=
2839 New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ));
2846 -- Check constrained case with known bounds
2848 if Is_Constrained (Opnd_Typ) then
2850 Index : constant Node_Id := First_Index (Opnd_Typ);
2851 Indx_Typ : constant Entity_Id := Etype (Index);
2852 Lo : constant Node_Id := Type_Low_Bound (Indx_Typ);
2853 Hi : constant Node_Id := Type_High_Bound (Indx_Typ);
2856 -- Fixed length constrained array type with known at compile
2857 -- time bounds is last case of fixed length operand.
2859 if Compile_Time_Known_Value (Lo)
2861 Compile_Time_Known_Value (Hi)
2864 Loval : constant Uint := Expr_Value (Lo);
2865 Hival : constant Uint := Expr_Value (Hi);
2866 Len : constant Uint :=
2867 UI_Max (Hival - Loval + 1, Uint_0);
2871 Result_May_Be_Null := False;
2874 -- Capture last operand bound if result could be null
2876 if J = N and then Result_May_Be_Null then
2877 Last_Opnd_High_Bound :=
2879 Make_Integer_Literal (Loc, Expr_Value (Hi)));
2882 -- Exclude null length case unless last operand
2884 if J < N and then Len = 0 then
2889 Operands (NN) := Opnd;
2890 Is_Fixed_Length (NN) := True;
2891 Fixed_Length (NN) := Len;
2893 Opnd_Low_Bound (NN) :=
2895 (Make_Integer_Literal (Loc, Expr_Value (Lo)));
2902 -- All cases where the length is not known at compile time, or the
2903 -- special case of an operand which is known to be null but has a
2904 -- lower bound other than 1 or is other than a string type.
2909 -- Capture operand bounds
2911 Opnd_Low_Bound (NN) :=
2912 Make_Attribute_Reference (Loc,
2914 Duplicate_Subexpr (Opnd, Name_Req => True),
2915 Attribute_Name => Name_First);
2917 if J = N and Result_May_Be_Null then
2918 Last_Opnd_High_Bound :=
2920 Make_Attribute_Reference (Loc,
2922 Duplicate_Subexpr (Opnd, Name_Req => True),
2923 Attribute_Name => Name_Last));
2926 -- Capture length of operand in entity
2928 Operands (NN) := Opnd;
2929 Is_Fixed_Length (NN) := False;
2931 Var_Length (NN) := Make_Temporary (Loc, 'L');
2934 Make_Object_Declaration (Loc,
2935 Defining_Identifier => Var_Length (NN),
2936 Constant_Present => True,
2937 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2939 Make_Attribute_Reference (Loc,
2941 Duplicate_Subexpr (Opnd, Name_Req => True),
2942 Attribute_Name => Name_Length)));
2946 -- Set next entry in aggregate length array
2948 -- For first entry, make either integer literal for fixed length
2949 -- or a reference to the saved length for variable length.
2952 if Is_Fixed_Length (1) then
2953 Aggr_Length (1) := Make_Integer_Literal (Loc, Fixed_Length (1));
2955 Aggr_Length (1) := New_Reference_To (Var_Length (1), Loc);
2958 -- If entry is fixed length and only fixed lengths so far, make
2959 -- appropriate new integer literal adding new length.
2961 elsif Is_Fixed_Length (NN)
2962 and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal
2965 Make_Integer_Literal (Loc,
2966 Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1)));
2968 -- All other cases, construct an addition node for the length and
2969 -- create an entity initialized to this length.
2972 Ent := Make_Temporary (Loc, 'L');
2974 if Is_Fixed_Length (NN) then
2975 Clen := Make_Integer_Literal (Loc, Fixed_Length (NN));
2977 Clen := New_Reference_To (Var_Length (NN), Loc);
2981 Make_Object_Declaration (Loc,
2982 Defining_Identifier => Ent,
2983 Constant_Present => True,
2984 Object_Definition => New_Occurrence_Of (Artyp, Loc),
2987 Left_Opnd => New_Copy (Aggr_Length (NN - 1)),
2988 Right_Opnd => Clen)));
2990 Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent));
2997 -- If we have only skipped null operands, return the last operand
3004 -- If we have only one non-null operand, return it and we are done.
3005 -- There is one case in which this cannot be done, and that is when
3006 -- the sole operand is of the element type, in which case it must be
3007 -- converted to an array, and the easiest way of doing that is to go
3008 -- through the normal general circuit.
3011 and then Base_Type (Etype (Operands (1))) /= Ctyp
3013 Result := Operands (1);
3017 -- Cases where we have a real concatenation
3019 -- Next step is to find the low bound for the result array that we
3020 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
3022 -- If the ultimate ancestor of the index subtype is a constrained array
3023 -- definition, then the lower bound is that of the index subtype as
3024 -- specified by (RM 4.5.3(6)).
3026 -- The right test here is to go to the root type, and then the ultimate
3027 -- ancestor is the first subtype of this root type.
3029 if Is_Constrained (First_Subtype (Root_Type (Atyp))) then
3031 Make_Attribute_Reference (Loc,
3033 New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc),
3034 Attribute_Name => Name_First);
3036 -- If the first operand in the list has known length we know that
3037 -- the lower bound of the result is the lower bound of this operand.
3039 elsif Is_Fixed_Length (1) then
3040 Low_Bound := Opnd_Low_Bound (1);
3042 -- OK, we don't know the lower bound, we have to build a horrible
3043 -- expression actions node of the form
3045 -- if Cond1'Length /= 0 then
3048 -- if Opnd2'Length /= 0 then
3053 -- The nesting ends either when we hit an operand whose length is known
3054 -- at compile time, or on reaching the last operand, whose low bound we
3055 -- take unconditionally whether or not it is null. It's easiest to do
3056 -- this with a recursive procedure:
3060 function Get_Known_Bound (J : Nat) return Node_Id;
3061 -- Returns the lower bound determined by operands J .. NN
3063 ---------------------
3064 -- Get_Known_Bound --
3065 ---------------------
3067 function Get_Known_Bound (J : Nat) return Node_Id is
3069 if Is_Fixed_Length (J) or else J = NN then
3070 return New_Copy (Opnd_Low_Bound (J));
3074 Make_Conditional_Expression (Loc,
3075 Expressions => New_List (
3078 Left_Opnd => New_Reference_To (Var_Length (J), Loc),
3079 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3081 New_Copy (Opnd_Low_Bound (J)),
3082 Get_Known_Bound (J + 1)));
3084 end Get_Known_Bound;
3087 Ent := Make_Temporary (Loc, 'L');
3090 Make_Object_Declaration (Loc,
3091 Defining_Identifier => Ent,
3092 Constant_Present => True,
3093 Object_Definition => New_Occurrence_Of (Ityp, Loc),
3094 Expression => Get_Known_Bound (1)));
3096 Low_Bound := New_Reference_To (Ent, Loc);
3100 -- Now we can safely compute the upper bound, normally
3101 -- Low_Bound + Length - 1.
3106 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3108 Make_Op_Subtract (Loc,
3109 Left_Opnd => New_Copy (Aggr_Length (NN)),
3110 Right_Opnd => Make_Artyp_Literal (1))));
3112 -- Note that calculation of the high bound may cause overflow in some
3113 -- very weird cases, so in the general case we need an overflow check on
3114 -- the high bound. We can avoid this for the common case of string types
3115 -- and other types whose index is Positive, since we chose a wider range
3116 -- for the arithmetic type.
3118 if Istyp /= Standard_Positive then
3119 Activate_Overflow_Check (High_Bound);
3122 -- Handle the exceptional case where the result is null, in which case
3123 -- case the bounds come from the last operand (so that we get the proper
3124 -- bounds if the last operand is super-flat).
3126 if Result_May_Be_Null then
3128 Make_Conditional_Expression (Loc,
3129 Expressions => New_List (
3131 Left_Opnd => New_Copy (Aggr_Length (NN)),
3132 Right_Opnd => Make_Artyp_Literal (0)),
3133 Last_Opnd_High_Bound,
3137 -- Here is where we insert the saved up actions
3139 Insert_Actions (Cnode, Actions, Suppress => All_Checks);
3141 -- Now we construct an array object with appropriate bounds. We mark
3142 -- the target as internal to prevent useless initialization when
3143 -- Initialize_Scalars is enabled. Also since this is the actual result
3144 -- entity, we make sure we have debug information for the result.
3146 Ent := Make_Temporary (Loc, 'S');
3147 Set_Is_Internal (Ent);
3148 Set_Needs_Debug_Info (Ent);
3150 -- If the bound is statically known to be out of range, we do not want
3151 -- to abort, we want a warning and a runtime constraint error. Note that
3152 -- we have arranged that the result will not be treated as a static
3153 -- constant, so we won't get an illegality during this insertion.
3155 Insert_Action (Cnode,
3156 Make_Object_Declaration (Loc,
3157 Defining_Identifier => Ent,
3158 Object_Definition =>
3159 Make_Subtype_Indication (Loc,
3160 Subtype_Mark => New_Occurrence_Of (Atyp, Loc),
3162 Make_Index_Or_Discriminant_Constraint (Loc,
3163 Constraints => New_List (
3165 Low_Bound => Low_Bound,
3166 High_Bound => High_Bound))))),
3167 Suppress => All_Checks);
3169 -- If the result of the concatenation appears as the initializing
3170 -- expression of an object declaration, we can just rename the
3171 -- result, rather than copying it.
3173 Set_OK_To_Rename (Ent);
3175 -- Catch the static out of range case now
3177 if Raises_Constraint_Error (High_Bound) then
3178 raise Concatenation_Error;
3181 -- Now we will generate the assignments to do the actual concatenation
3183 -- There is one case in which we will not do this, namely when all the
3184 -- following conditions are met:
3186 -- The result type is Standard.String
3188 -- There are nine or fewer retained (non-null) operands
3190 -- The optimization level is -O0
3192 -- The corresponding System.Concat_n.Str_Concat_n routine is
3193 -- available in the run time.
3195 -- The debug flag gnatd.c is not set
3197 -- If all these conditions are met then we generate a call to the
3198 -- relevant concatenation routine. The purpose of this is to avoid
3199 -- undesirable code bloat at -O0.
3201 if Atyp = Standard_String
3202 and then NN in 2 .. 9
3203 and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC)
3204 and then not Debug_Flag_Dot_C
3207 RR : constant array (Nat range 2 .. 9) of RE_Id :=
3218 if RTE_Available (RR (NN)) then
3220 Opnds : constant List_Id :=
3221 New_List (New_Occurrence_Of (Ent, Loc));
3224 for J in 1 .. NN loop
3225 if Is_List_Member (Operands (J)) then
3226 Remove (Operands (J));
3229 if Base_Type (Etype (Operands (J))) = Ctyp then
3231 Make_Aggregate (Loc,
3232 Component_Associations => New_List (
3233 Make_Component_Association (Loc,
3234 Choices => New_List (
3235 Make_Integer_Literal (Loc, 1)),
3236 Expression => Operands (J)))));
3239 Append_To (Opnds, Operands (J));
3243 Insert_Action (Cnode,
3244 Make_Procedure_Call_Statement (Loc,
3245 Name => New_Reference_To (RTE (RR (NN)), Loc),
3246 Parameter_Associations => Opnds));
3248 Result := New_Reference_To (Ent, Loc);
3255 -- Not special case so generate the assignments
3257 Known_Non_Null_Operand_Seen := False;
3259 for J in 1 .. NN loop
3261 Lo : constant Node_Id :=
3263 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3264 Right_Opnd => Aggr_Length (J - 1));
3266 Hi : constant Node_Id :=
3268 Left_Opnd => To_Artyp (New_Copy (Low_Bound)),
3270 Make_Op_Subtract (Loc,
3271 Left_Opnd => Aggr_Length (J),
3272 Right_Opnd => Make_Artyp_Literal (1)));
3275 -- Singleton case, simple assignment
3277 if Base_Type (Etype (Operands (J))) = Ctyp then
3278 Known_Non_Null_Operand_Seen := True;
3279 Insert_Action (Cnode,
3280 Make_Assignment_Statement (Loc,
3282 Make_Indexed_Component (Loc,
3283 Prefix => New_Occurrence_Of (Ent, Loc),
3284 Expressions => New_List (To_Ityp (Lo))),
3285 Expression => Operands (J)),
3286 Suppress => All_Checks);
3288 -- Array case, slice assignment, skipped when argument is fixed
3289 -- length and known to be null.
3291 elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then
3294 Make_Assignment_Statement (Loc,
3298 New_Occurrence_Of (Ent, Loc),
3301 Low_Bound => To_Ityp (Lo),
3302 High_Bound => To_Ityp (Hi))),
3303 Expression => Operands (J));
3305 if Is_Fixed_Length (J) then
3306 Known_Non_Null_Operand_Seen := True;
3308 elsif not Known_Non_Null_Operand_Seen then
3310 -- Here if operand length is not statically known and no
3311 -- operand known to be non-null has been processed yet.
3312 -- If operand length is 0, we do not need to perform the
3313 -- assignment, and we must avoid the evaluation of the
3314 -- high bound of the slice, since it may underflow if the
3315 -- low bound is Ityp'First.
3318 Make_Implicit_If_Statement (Cnode,
3322 New_Occurrence_Of (Var_Length (J), Loc),
3323 Right_Opnd => Make_Integer_Literal (Loc, 0)),
3324 Then_Statements => New_List (Assign));
3327 Insert_Action (Cnode, Assign, Suppress => All_Checks);
3333 -- Finally we build the result, which is a reference to the array object
3335 Result := New_Reference_To (Ent, Loc);
3338 Rewrite (Cnode, Result);
3339 Analyze_And_Resolve (Cnode, Atyp);
3342 when Concatenation_Error =>
3344 -- Kill warning generated for the declaration of the static out of
3345 -- range high bound, and instead generate a Constraint_Error with
3346 -- an appropriate specific message.
3348 Kill_Dead_Code (Declaration_Node (Entity (High_Bound)));
3349 Apply_Compile_Time_Constraint_Error
3351 Msg => "concatenation result upper bound out of range?",
3352 Reason => CE_Range_Check_Failed);
3353 -- Set_Etype (Cnode, Atyp);
3354 end Expand_Concatenate;
3356 ------------------------
3357 -- Expand_N_Allocator --
3358 ------------------------
3360 procedure Expand_N_Allocator (N : Node_Id) is
3361 PtrT : constant Entity_Id := Etype (N);
3362 Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT));
3363 Etyp : constant Entity_Id := Etype (Expression (N));
3364 Loc : constant Source_Ptr := Sloc (N);
3370 procedure Rewrite_Coextension (N : Node_Id);
3371 -- Static coextensions have the same lifetime as the entity they
3372 -- constrain. Such occurrences can be rewritten as aliased objects
3373 -- and their unrestricted access used instead of the coextension.
3375 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id;
3376 -- Given a constrained array type E, returns a node representing the
3377 -- code to compute the size in storage elements for the given type.
3378 -- This is done without using the attribute (which malfunctions for
3381 -------------------------
3382 -- Rewrite_Coextension --
3383 -------------------------
3385 procedure Rewrite_Coextension (N : Node_Id) is
3386 Temp_Id : constant Node_Id := Make_Temporary (Loc, 'C');
3387 Temp_Decl : Node_Id;
3388 Insert_Nod : Node_Id;
3392 -- Cnn : aliased Etyp;
3395 Make_Object_Declaration (Loc,
3396 Defining_Identifier => Temp_Id,
3397 Aliased_Present => True,
3398 Object_Definition => New_Occurrence_Of (Etyp, Loc));
3400 if Nkind (Expression (N)) = N_Qualified_Expression then
3401 Set_Expression (Temp_Decl, Expression (Expression (N)));
3404 -- Find the proper insertion node for the declaration
3406 Insert_Nod := Parent (N);
3407 while Present (Insert_Nod) loop
3409 Nkind (Insert_Nod) in N_Statement_Other_Than_Procedure_Call
3410 or else Nkind (Insert_Nod) = N_Procedure_Call_Statement
3411 or else Nkind (Insert_Nod) in N_Declaration;
3413 Insert_Nod := Parent (Insert_Nod);
3416 Insert_Before (Insert_Nod, Temp_Decl);
3417 Analyze (Temp_Decl);
3420 Make_Attribute_Reference (Loc,
3421 Prefix => New_Occurrence_Of (Temp_Id, Loc),
3422 Attribute_Name => Name_Unrestricted_Access));
3424 Analyze_And_Resolve (N, PtrT);
3425 end Rewrite_Coextension;
3427 ------------------------------
3428 -- Size_In_Storage_Elements --
3429 ------------------------------
3431 function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is
3433 -- Logically this just returns E'Max_Size_In_Storage_Elements.
3434 -- However, the reason for the existence of this function is
3435 -- to construct a test for sizes too large, which means near the
3436 -- 32-bit limit on a 32-bit machine, and precisely the trouble
3437 -- is that we get overflows when sizes are greater than 2**31.
3439 -- So what we end up doing for array types is to use the expression:
3441 -- number-of-elements * component_type'Max_Size_In_Storage_Elements
3443 -- which avoids this problem. All this is a bit bogus, but it does
3444 -- mean we catch common cases of trying to allocate arrays that
3445 -- are too large, and which in the absence of a check results in
3446 -- undetected chaos ???
3453 for J in 1 .. Number_Dimensions (E) loop
3455 Make_Attribute_Reference (Loc,
3456 Prefix => New_Occurrence_Of (E, Loc),
3457 Attribute_Name => Name_Length,
3458 Expressions => New_List (Make_Integer_Literal (Loc, J)));
3465 Make_Op_Multiply (Loc,
3472 Make_Op_Multiply (Loc,
3475 Make_Attribute_Reference (Loc,
3476 Prefix => New_Occurrence_Of (Component_Type (E), Loc),
3477 Attribute_Name => Name_Max_Size_In_Storage_Elements));
3479 end Size_In_Storage_Elements;
3481 -- Start of processing for Expand_N_Allocator
3484 -- RM E.2.3(22). We enforce that the expected type of an allocator
3485 -- shall not be a remote access-to-class-wide-limited-private type
3487 -- Why is this being done at expansion time, seems clearly wrong ???
3489 Validate_Remote_Access_To_Class_Wide_Type (N);
3491 -- Processing for anonymous access-to-controlled types. These access
3492 -- types receive a special finalization master which appears in the
3493 -- declarations of the enclosing semantic unit. This expansion is done
3494 -- now to ensure that any additional types generated by this routine
3495 -- or Expand_Allocator_Expression inherit the proper type attributes.
3497 if Ekind (PtrT) = E_Anonymous_Access_Type
3498 and then Needs_Finalization (Dtyp)
3500 -- Anonymous access-to-controlled types allocate on the global pool.
3501 -- Do not set this attribute on .NET/JVM since those targets do not
3504 if No (Associated_Storage_Pool (PtrT))
3505 and then VM_Target = No_VM
3507 Set_Associated_Storage_Pool
3508 (PtrT, Get_Global_Pool_For_Access_Type (PtrT));
3511 -- The finalization master must be inserted and analyzed as part of
3512 -- the current semantic unit. This form of expansion is not carried
3513 -- out in Alfa mode because it is useless. Note that the master is
3514 -- updated when analysis changes current units.
3516 if not Alfa_Mode then
3517 Set_Finalization_Master (PtrT, Current_Anonymous_Master);
3521 -- Set the storage pool and find the appropriate version of Allocate to
3522 -- call. Do not overwrite the storage pool if it is already set, which
3523 -- can happen for build-in-place function returns (see
3524 -- Exp_Ch4.Expand_N_Extended_Return_Statement).
3526 if No (Storage_Pool (N)) then
3527 Pool := Associated_Storage_Pool (Root_Type (PtrT));
3529 if Present (Pool) then
3530 Set_Storage_Pool (N, Pool);
3532 if Is_RTE (Pool, RE_SS_Pool) then
3533 if VM_Target = No_VM then
3534 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
3537 elsif Is_Class_Wide_Type (Etype (Pool)) then
3538 Set_Procedure_To_Call (N, RTE (RE_Allocate_Any));
3541 Set_Procedure_To_Call (N,
3542 Find_Prim_Op (Etype (Pool), Name_Allocate));
3547 -- Under certain circumstances we can replace an allocator by an access
3548 -- to statically allocated storage. The conditions, as noted in AARM
3549 -- 3.10 (10c) are as follows:
3551 -- Size and initial value is known at compile time
3552 -- Access type is access-to-constant
3554 -- The allocator is not part of a constraint on a record component,
3555 -- because in that case the inserted actions are delayed until the
3556 -- record declaration is fully analyzed, which is too late for the
3557 -- analysis of the rewritten allocator.
3559 if Is_Access_Constant (PtrT)
3560 and then Nkind (Expression (N)) = N_Qualified_Expression
3561 and then Compile_Time_Known_Value (Expression (Expression (N)))
3562 and then Size_Known_At_Compile_Time
3563 (Etype (Expression (Expression (N))))
3564 and then not Is_Record_Type (Current_Scope)
3566 -- Here we can do the optimization. For the allocator
3570 -- We insert an object declaration
3572 -- Tnn : aliased x := y;
3574 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
3575 -- marked as requiring static allocation.
3577 Temp := Make_Temporary (Loc, 'T', Expression (Expression (N)));
3578 Desig := Subtype_Mark (Expression (N));
3580 -- If context is constrained, use constrained subtype directly,
3581 -- so that the constant is not labelled as having a nominally
3582 -- unconstrained subtype.
3584 if Entity (Desig) = Base_Type (Dtyp) then
3585 Desig := New_Occurrence_Of (Dtyp, Loc);
3589 Make_Object_Declaration (Loc,
3590 Defining_Identifier => Temp,
3591 Aliased_Present => True,
3592 Constant_Present => Is_Access_Constant (PtrT),
3593 Object_Definition => Desig,
3594 Expression => Expression (Expression (N))));
3597 Make_Attribute_Reference (Loc,
3598 Prefix => New_Occurrence_Of (Temp, Loc),
3599 Attribute_Name => Name_Unrestricted_Access));
3601 Analyze_And_Resolve (N, PtrT);
3603 -- We set the variable as statically allocated, since we don't want
3604 -- it going on the stack of the current procedure!
3606 Set_Is_Statically_Allocated (Temp);
3610 -- Same if the allocator is an access discriminant for a local object:
3611 -- instead of an allocator we create a local value and constrain the
3612 -- enclosing object with the corresponding access attribute.
3614 if Is_Static_Coextension (N) then
3615 Rewrite_Coextension (N);
3619 -- Check for size too large, we do this because the back end misses
3620 -- proper checks here and can generate rubbish allocation calls when
3621 -- we are near the limit. We only do this for the 32-bit address case
3622 -- since that is from a practical point of view where we see a problem.
3624 if System_Address_Size = 32
3625 and then not Storage_Checks_Suppressed (PtrT)
3626 and then not Storage_Checks_Suppressed (Dtyp)
3627 and then not Storage_Checks_Suppressed (Etyp)
3629 -- The check we want to generate should look like
3631 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
3632 -- raise Storage_Error;
3635 -- where 3.5 gigabytes is a constant large enough to accommodate any
3636 -- reasonable request for. But we can't do it this way because at
3637 -- least at the moment we don't compute this attribute right, and
3638 -- can silently give wrong results when the result gets large. Since
3639 -- this is all about large results, that's bad, so instead we only
3640 -- apply the check for constrained arrays, and manually compute the
3641 -- value of the attribute ???
3643 if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then
3645 Make_Raise_Storage_Error (Loc,
3648 Left_Opnd => Size_In_Storage_Elements (Etyp),
3650 Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))),
3651 Reason => SE_Object_Too_Large));
3655 -- Handle case of qualified expression (other than optimization above)
3656 -- First apply constraint checks, because the bounds or discriminants
3657 -- in the aggregate might not match the subtype mark in the allocator.
3659 if Nkind (Expression (N)) = N_Qualified_Expression then
3660 Apply_Constraint_Check
3661 (Expression (Expression (N)), Etype (Expression (N)));
3663 Expand_Allocator_Expression (N);
3667 -- If the allocator is for a type which requires initialization, and
3668 -- there is no initial value (i.e. operand is a subtype indication
3669 -- rather than a qualified expression), then we must generate a call to
3670 -- the initialization routine using an expressions action node:
3672 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
3674 -- Here ptr_T is the pointer type for the allocator, and T is the
3675 -- subtype of the allocator. A special case arises if the designated
3676 -- type of the access type is a task or contains tasks. In this case
3677 -- the call to Init (Temp.all ...) is replaced by code that ensures
3678 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
3679 -- for details). In addition, if the type T is a task T, then the
3680 -- first argument to Init must be converted to the task record type.
3683 T : constant Entity_Id := Entity (Expression (N));
3689 Init_Arg1 : Node_Id;
3690 Temp_Decl : Node_Id;
3691 Temp_Type : Entity_Id;
3694 if No_Initialization (N) then
3696 -- Even though this might be a simple allocation, create a custom
3697 -- Allocate if the context requires it. Since .NET/JVM compilers
3698 -- do not support pools, this step is skipped.
3700 if VM_Target = No_VM
3701 and then Present (Finalization_Master (PtrT))
3703 Build_Allocate_Deallocate_Proc
3705 Is_Allocate => True);
3708 -- Case of no initialization procedure present
3710 elsif not Has_Non_Null_Base_Init_Proc (T) then
3712 -- Case of simple initialization required
3714 if Needs_Simple_Initialization (T) then
3715 Check_Restriction (No_Default_Initialization, N);
3716 Rewrite (Expression (N),
3717 Make_Qualified_Expression (Loc,
3718 Subtype_Mark => New_Occurrence_Of (T, Loc),
3719 Expression => Get_Simple_Init_Val (T, N)));
3721 Analyze_And_Resolve (Expression (Expression (N)), T);
3722 Analyze_And_Resolve (Expression (N), T);
3723 Set_Paren_Count (Expression (Expression (N)), 1);
3724 Expand_N_Allocator (N);
3726 -- No initialization required
3732 -- Case of initialization procedure present, must be called
3735 Check_Restriction (No_Default_Initialization, N);
3737 if not Restriction_Active (No_Default_Initialization) then
3738 Init := Base_Init_Proc (T);
3740 Temp := Make_Temporary (Loc, 'P');
3742 -- Construct argument list for the initialization routine call
3745 Make_Explicit_Dereference (Loc,
3747 New_Reference_To (Temp, Loc));
3749 Set_Assignment_OK (Init_Arg1);
3752 -- The initialization procedure expects a specific type. if the
3753 -- context is access to class wide, indicate that the object
3754 -- being allocated has the right specific type.
3756 if Is_Class_Wide_Type (Dtyp) then
3757 Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1);
3760 -- If designated type is a concurrent type or if it is private
3761 -- type whose definition is a concurrent type, the first
3762 -- argument in the Init routine has to be unchecked conversion
3763 -- to the corresponding record type. If the designated type is
3764 -- a derived type, also convert the argument to its root type.
3766 if Is_Concurrent_Type (T) then
3768 Unchecked_Convert_To (
3769 Corresponding_Record_Type (T), Init_Arg1);
3771 elsif Is_Private_Type (T)
3772 and then Present (Full_View (T))
3773 and then Is_Concurrent_Type (Full_View (T))
3776 Unchecked_Convert_To
3777 (Corresponding_Record_Type (Full_View (T)), Init_Arg1);
3779 elsif Etype (First_Formal (Init)) /= Base_Type (T) then
3781 Ftyp : constant Entity_Id := Etype (First_Formal (Init));
3784 Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1);
3785 Set_Etype (Init_Arg1, Ftyp);
3789 Args := New_List (Init_Arg1);
3791 -- For the task case, pass the Master_Id of the access type as
3792 -- the value of the _Master parameter, and _Chain as the value
3793 -- of the _Chain parameter (_Chain will be defined as part of
3794 -- the generated code for the allocator).
3796 -- In Ada 2005, the context may be a function that returns an
3797 -- anonymous access type. In that case the Master_Id has been
3798 -- created when expanding the function declaration.
3800 if Has_Task (T) then
3801 if No (Master_Id (Base_Type (PtrT))) then
3803 -- The designated type was an incomplete type, and the
3804 -- access type did not get expanded. Salvage it now.
3806 if not Restriction_Active (No_Task_Hierarchy) then
3807 pragma Assert (Present (Parent (Base_Type (PtrT))));
3808 Expand_N_Full_Type_Declaration
3809 (Parent (Base_Type (PtrT)));
3813 -- If the context of the allocator is a declaration or an
3814 -- assignment, we can generate a meaningful image for it,
3815 -- even though subsequent assignments might remove the
3816 -- connection between task and entity. We build this image
3817 -- when the left-hand side is a simple variable, a simple
3818 -- indexed assignment or a simple selected component.
3820 if Nkind (Parent (N)) = N_Assignment_Statement then
3822 Nam : constant Node_Id := Name (Parent (N));
3825 if Is_Entity_Name (Nam) then
3827 Build_Task_Image_Decls
3830 (Entity (Nam), Sloc (Nam)), T);
3832 elsif Nkind_In (Nam, N_Indexed_Component,
3833 N_Selected_Component)
3834 and then Is_Entity_Name (Prefix (Nam))
3837 Build_Task_Image_Decls
3838 (Loc, Nam, Etype (Prefix (Nam)));
3840 Decls := Build_Task_Image_Decls (Loc, T, T);
3844 elsif Nkind (Parent (N)) = N_Object_Declaration then
3846 Build_Task_Image_Decls
3847 (Loc, Defining_Identifier (Parent (N)), T);
3850 Decls := Build_Task_Image_Decls (Loc, T, T);
3853 if Restriction_Active (No_Task_Hierarchy) then
3855 New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc));
3859 (Master_Id (Base_Type (Root_Type (PtrT))), Loc));
3862 Append_To (Args, Make_Identifier (Loc, Name_uChain));
3864 Decl := Last (Decls);
3866 New_Occurrence_Of (Defining_Identifier (Decl), Loc));
3868 -- Has_Task is false, Decls not used
3874 -- Add discriminants if discriminated type
3877 Dis : Boolean := False;
3881 if Has_Discriminants (T) then
3885 elsif Is_Private_Type (T)
3886 and then Present (Full_View (T))
3887 and then Has_Discriminants (Full_View (T))
3890 Typ := Full_View (T);
3895 -- If the allocated object will be constrained by the
3896 -- default values for discriminants, then build a subtype
3897 -- with those defaults, and change the allocated subtype
3898 -- to that. Note that this happens in fewer cases in Ada
3901 if not Is_Constrained (Typ)
3902 and then Present (Discriminant_Default_Value
3903 (First_Discriminant (Typ)))
3904 and then (Ada_Version < Ada_2005
3906 Effectively_Has_Constrained_Partial_View
3908 Scop => Current_Scope))
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));
4471 -- If the type is an Atomic type for which Atomic_Sync is enabled, then
4472 -- we set the atomic sync flag.
4474 if Is_Atomic (Etype (N))
4475 and then not Atomic_Synchronization_Disabled (Etype (N))
4477 Activate_Atomic_Synchronization (N);
4479 end Expand_N_Explicit_Dereference;
4481 --------------------------------------
4482 -- Expand_N_Expression_With_Actions --
4483 --------------------------------------
4485 procedure Expand_N_Expression_With_Actions (N : Node_Id) is
4487 procedure Process_Transient_Object (Decl : Node_Id);
4488 -- Given the declaration of a controlled transient declared inside the
4489 -- Actions list of an Expression_With_Actions, generate all necessary
4490 -- types and hooks in order to properly finalize the transient. This
4491 -- mechanism works in conjunction with Build_Finalizer.
4493 ------------------------------
4494 -- Process_Transient_Object --
4495 ------------------------------
4497 procedure Process_Transient_Object (Decl : Node_Id) is
4499 function Find_Insertion_Node return Node_Id;
4500 -- Complex conditions in if statements may be converted into nested
4501 -- EWAs. In this case, any generated code must be inserted before the
4502 -- if statement to ensure proper visibility of the hook objects. This
4503 -- routine returns the top most short circuit operator or the parent
4504 -- of the EWA if no nesting was detected.
4506 -------------------------
4507 -- Find_Insertion_Node --
4508 -------------------------
4510 function Find_Insertion_Node return Node_Id is
4514 -- Climb up the branches of a complex condition
4517 while Nkind_In (Parent (Par), N_And_Then, N_Op_Not, N_Or_Else) loop
4518 Par := Parent (Par);
4522 end Find_Insertion_Node;
4526 Ins_Node : constant Node_Id := Find_Insertion_Node;
4527 Loc : constant Source_Ptr := Sloc (Decl);
4528 Obj_Id : constant Entity_Id := Defining_Identifier (Decl);
4529 Obj_Typ : constant Entity_Id := Etype (Obj_Id);
4530 Desig_Typ : Entity_Id;
4534 Temp_Decl : Node_Id;
4537 -- Start of processing for Process_Transient_Object
4540 -- Step 1: Create the access type which provides a reference to the
4541 -- transient object.
4543 if Is_Access_Type (Obj_Typ) then
4544 Desig_Typ := Directly_Designated_Type (Obj_Typ);
4546 Desig_Typ := Obj_Typ;
4550 -- Ann : access [all] <Desig_Typ>;
4552 Ptr_Id := Make_Temporary (Loc, 'A');
4555 Make_Full_Type_Declaration (Loc,
4556 Defining_Identifier => Ptr_Id,
4558 Make_Access_To_Object_Definition (Loc,
4560 Ekind (Obj_Typ) = E_General_Access_Type,
4561 Subtype_Indication => New_Reference_To (Desig_Typ, Loc)));
4563 Insert_Action (Ins_Node, Ptr_Decl);
4566 -- Step 2: Create a temporary which acts as a hook to the transient
4567 -- object. Generate:
4569 -- Temp : Ptr_Id := null;
4571 Temp_Id := Make_Temporary (Loc, 'T');
4574 Make_Object_Declaration (Loc,
4575 Defining_Identifier => Temp_Id,
4576 Object_Definition => New_Reference_To (Ptr_Id, Loc));
4578 Insert_Action (Ins_Node, Temp_Decl);
4579 Analyze (Temp_Decl);
4581 -- Mark this temporary as created for the purposes of exporting the
4582 -- transient declaration out of the Actions list. This signals the
4583 -- machinery in Build_Finalizer to recognize this special case.
4585 Set_Return_Flag_Or_Transient_Decl (Temp_Id, Decl);
4587 -- Step 3: Hook the transient object to the temporary
4589 if Is_Access_Type (Obj_Typ) then
4590 Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc));
4593 Make_Attribute_Reference (Loc,
4594 Prefix => New_Reference_To (Obj_Id, Loc),
4595 Attribute_Name => Name_Unrestricted_Access);
4599 -- Temp := Ptr_Id (Obj_Id);
4601 -- Temp := Obj_Id'Unrestricted_Access;
4603 Insert_After_And_Analyze (Decl,
4604 Make_Assignment_Statement (Loc,
4605 Name => New_Reference_To (Temp_Id, Loc),
4606 Expression => Expr));
4607 end Process_Transient_Object;
4613 -- Start of processing for Expand_N_Expression_With_Actions
4616 Decl := First (Actions (N));
4617 while Present (Decl) loop
4618 if Nkind (Decl) = N_Object_Declaration
4619 and then Is_Finalizable_Transient (Decl, N)
4621 Process_Transient_Object (Decl);
4626 end Expand_N_Expression_With_Actions;
4632 procedure Expand_N_In (N : Node_Id) is
4633 Loc : constant Source_Ptr := Sloc (N);
4634 Restyp : constant Entity_Id := Etype (N);
4635 Lop : constant Node_Id := Left_Opnd (N);
4636 Rop : constant Node_Id := Right_Opnd (N);
4637 Static : constant Boolean := Is_OK_Static_Expression (N);
4642 procedure Substitute_Valid_Check;
4643 -- Replaces node N by Lop'Valid. This is done when we have an explicit
4644 -- test for the left operand being in range of its subtype.
4646 ----------------------------
4647 -- Substitute_Valid_Check --
4648 ----------------------------
4650 procedure Substitute_Valid_Check is
4653 Make_Attribute_Reference (Loc,
4654 Prefix => Relocate_Node (Lop),
4655 Attribute_Name => Name_Valid));
4657 Analyze_And_Resolve (N, Restyp);
4659 Error_Msg_N ("?explicit membership test may be optimized away", N);
4660 Error_Msg_N -- CODEFIX
4661 ("\?use ''Valid attribute instead", N);
4663 end Substitute_Valid_Check;
4665 -- Start of processing for Expand_N_In
4668 -- If set membership case, expand with separate procedure
4670 if Present (Alternatives (N)) then
4671 Expand_Set_Membership (N);
4675 -- Not set membership, proceed with expansion
4677 Ltyp := Etype (Left_Opnd (N));
4678 Rtyp := Etype (Right_Opnd (N));
4680 -- Check case of explicit test for an expression in range of its
4681 -- subtype. This is suspicious usage and we replace it with a 'Valid
4682 -- test and give a warning. For floating point types however, this is a
4683 -- standard way to check for finite numbers, and using 'Valid would
4684 -- typically be a pessimization. Also skip this test for predicated
4685 -- types, since it is perfectly reasonable to check if a value meets
4688 if Is_Scalar_Type (Ltyp)
4689 and then not Is_Floating_Point_Type (Ltyp)
4690 and then Nkind (Rop) in N_Has_Entity
4691 and then Ltyp = Entity (Rop)
4692 and then Comes_From_Source (N)
4693 and then VM_Target = No_VM
4694 and then not (Is_Discrete_Type (Ltyp)
4695 and then Present (Predicate_Function (Ltyp)))
4697 Substitute_Valid_Check;
4701 -- Do validity check on operands
4703 if Validity_Checks_On and Validity_Check_Operands then
4704 Ensure_Valid (Left_Opnd (N));
4705 Validity_Check_Range (Right_Opnd (N));
4708 -- Case of explicit range
4710 if Nkind (Rop) = N_Range then
4712 Lo : constant Node_Id := Low_Bound (Rop);
4713 Hi : constant Node_Id := High_Bound (Rop);
4715 Lo_Orig : constant Node_Id := Original_Node (Lo);
4716 Hi_Orig : constant Node_Id := Original_Node (Hi);
4718 Lcheck : Compare_Result;
4719 Ucheck : Compare_Result;
4721 Warn1 : constant Boolean :=
4722 Constant_Condition_Warnings
4723 and then Comes_From_Source (N)
4724 and then not In_Instance;
4725 -- This must be true for any of the optimization warnings, we
4726 -- clearly want to give them only for source with the flag on. We
4727 -- also skip these warnings in an instance since it may be the
4728 -- case that different instantiations have different ranges.
4730 Warn2 : constant Boolean :=
4732 and then Nkind (Original_Node (Rop)) = N_Range
4733 and then Is_Integer_Type (Etype (Lo));
4734 -- For the case where only one bound warning is elided, we also
4735 -- insist on an explicit range and an integer type. The reason is
4736 -- that the use of enumeration ranges including an end point is
4737 -- common, as is the use of a subtype name, one of whose bounds is
4738 -- the same as the type of the expression.
4741 -- If test is explicit x'First .. x'Last, replace by valid check
4743 -- Could use some individual comments for this complex test ???
4745 if Is_Scalar_Type (Ltyp)
4746 and then Nkind (Lo_Orig) = N_Attribute_Reference
4747 and then Attribute_Name (Lo_Orig) = Name_First
4748 and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity
4749 and then Entity (Prefix (Lo_Orig)) = Ltyp
4750 and then Nkind (Hi_Orig) = N_Attribute_Reference
4751 and then Attribute_Name (Hi_Orig) = Name_Last
4752 and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity
4753 and then Entity (Prefix (Hi_Orig)) = Ltyp
4754 and then Comes_From_Source (N)
4755 and then VM_Target = No_VM
4757 Substitute_Valid_Check;
4761 -- If bounds of type are known at compile time, and the end points
4762 -- are known at compile time and identical, this is another case
4763 -- for substituting a valid test. We only do this for discrete
4764 -- types, since it won't arise in practice for float types.
4766 if Comes_From_Source (N)
4767 and then Is_Discrete_Type (Ltyp)
4768 and then Compile_Time_Known_Value (Type_High_Bound (Ltyp))
4769 and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp))
4770 and then Compile_Time_Known_Value (Lo)
4771 and then Compile_Time_Known_Value (Hi)
4772 and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi)
4773 and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo)
4775 -- Kill warnings in instances, since they may be cases where we
4776 -- have a test in the generic that makes sense with some types
4777 -- and not with other types.
4779 and then not In_Instance
4781 Substitute_Valid_Check;
4785 -- If we have an explicit range, do a bit of optimization based on
4786 -- range analysis (we may be able to kill one or both checks).
4788 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False);
4789 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False);
4791 -- If either check is known to fail, replace result by False since
4792 -- the other check does not matter. Preserve the static flag for
4793 -- legality checks, because we are constant-folding beyond RM 4.9.
4795 if Lcheck = LT or else Ucheck = GT then
4797 Error_Msg_N ("?range test optimized away", N);
4798 Error_Msg_N ("\?value is known to be out of range", N);
4801 Rewrite (N, New_Reference_To (Standard_False, Loc));
4802 Analyze_And_Resolve (N, Restyp);
4803 Set_Is_Static_Expression (N, Static);
4806 -- If both checks are known to succeed, replace result by True,
4807 -- since we know we are in range.
4809 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4811 Error_Msg_N ("?range test optimized away", N);
4812 Error_Msg_N ("\?value is known to be in range", N);
4815 Rewrite (N, New_Reference_To (Standard_True, Loc));
4816 Analyze_And_Resolve (N, Restyp);
4817 Set_Is_Static_Expression (N, Static);
4820 -- If lower bound check succeeds and upper bound check is not
4821 -- known to succeed or fail, then replace the range check with
4822 -- a comparison against the upper bound.
4824 elsif Lcheck in Compare_GE then
4825 if Warn2 and then not In_Instance then
4826 Error_Msg_N ("?lower bound test optimized away", Lo);
4827 Error_Msg_N ("\?value is known to be in range", Lo);
4833 Right_Opnd => High_Bound (Rop)));
4834 Analyze_And_Resolve (N, Restyp);
4837 -- If upper bound check succeeds and lower bound check is not
4838 -- known to succeed or fail, then replace the range check with
4839 -- a comparison against the lower bound.
4841 elsif Ucheck in Compare_LE then
4842 if Warn2 and then not In_Instance then
4843 Error_Msg_N ("?upper bound test optimized away", Hi);
4844 Error_Msg_N ("\?value is known to be in range", Hi);
4850 Right_Opnd => Low_Bound (Rop)));
4851 Analyze_And_Resolve (N, Restyp);
4855 -- We couldn't optimize away the range check, but there is one
4856 -- more issue. If we are checking constant conditionals, then we
4857 -- see if we can determine the outcome assuming everything is
4858 -- valid, and if so give an appropriate warning.
4860 if Warn1 and then not Assume_No_Invalid_Values then
4861 Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True);
4862 Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True);
4864 -- Result is out of range for valid value
4866 if Lcheck = LT or else Ucheck = GT then
4868 ("?value can only be in range if it is invalid", N);
4870 -- Result is in range for valid value
4872 elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then
4874 ("?value can only be out of range if it is invalid", N);
4876 -- Lower bound check succeeds if value is valid
4878 elsif Warn2 and then Lcheck in Compare_GE then
4880 ("?lower bound check only fails if it is invalid", Lo);
4882 -- Upper bound check succeeds if value is valid
4884 elsif Warn2 and then Ucheck in Compare_LE then
4886 ("?upper bound check only fails for invalid values", Hi);
4891 -- For all other cases of an explicit range, nothing to be done
4895 -- Here right operand is a subtype mark
4899 Typ : Entity_Id := Etype (Rop);
4900 Is_Acc : constant Boolean := Is_Access_Type (Typ);
4901 Cond : Node_Id := Empty;
4903 Obj : Node_Id := Lop;
4904 SCIL_Node : Node_Id;
4907 Remove_Side_Effects (Obj);
4909 -- For tagged type, do tagged membership operation
4911 if Is_Tagged_Type (Typ) then
4913 -- No expansion will be performed when VM_Target, as the VM
4914 -- back-ends will handle the membership tests directly (tags
4915 -- are not explicitly represented in Java objects, so the
4916 -- normal tagged membership expansion is not what we want).
4918 if Tagged_Type_Expansion then
4919 Tagged_Membership (N, SCIL_Node, New_N);
4921 Analyze_And_Resolve (N, Restyp);
4923 -- Update decoration of relocated node referenced by the
4926 if Generate_SCIL and then Present (SCIL_Node) then
4927 Set_SCIL_Node (N, SCIL_Node);
4933 -- If type is scalar type, rewrite as x in t'First .. t'Last.
4934 -- This reason we do this is that the bounds may have the wrong
4935 -- type if they come from the original type definition. Also this
4936 -- way we get all the processing above for an explicit range.
4938 -- Don't do this for predicated types, since in this case we
4939 -- want to check the predicate!
4941 elsif Is_Scalar_Type (Typ) then
4942 if No (Predicate_Function (Typ)) then
4946 Make_Attribute_Reference (Loc,
4947 Attribute_Name => Name_First,
4948 Prefix => New_Reference_To (Typ, Loc)),
4951 Make_Attribute_Reference (Loc,
4952 Attribute_Name => Name_Last,
4953 Prefix => New_Reference_To (Typ, Loc))));
4954 Analyze_And_Resolve (N, Restyp);
4959 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
4960 -- a membership test if the subtype mark denotes a constrained
4961 -- Unchecked_Union subtype and the expression lacks inferable
4964 elsif Is_Unchecked_Union (Base_Type (Typ))
4965 and then Is_Constrained (Typ)
4966 and then not Has_Inferable_Discriminants (Lop)
4969 Make_Raise_Program_Error (Loc,
4970 Reason => PE_Unchecked_Union_Restriction));
4972 -- Prevent Gigi from generating incorrect code by rewriting the
4975 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
4979 -- Here we have a non-scalar type
4982 Typ := Designated_Type (Typ);
4985 if not Is_Constrained (Typ) then
4986 Rewrite (N, New_Reference_To (Standard_True, Loc));
4987 Analyze_And_Resolve (N, Restyp);
4989 -- For the constrained array case, we have to check the subscripts
4990 -- for an exact match if the lengths are non-zero (the lengths
4991 -- must match in any case).
4993 elsif Is_Array_Type (Typ) then
4994 Check_Subscripts : declare
4995 function Build_Attribute_Reference
4998 Dim : Nat) return Node_Id;
4999 -- Build attribute reference E'Nam (Dim)
5001 -------------------------------
5002 -- Build_Attribute_Reference --
5003 -------------------------------
5005 function Build_Attribute_Reference
5008 Dim : Nat) return Node_Id
5012 Make_Attribute_Reference (Loc,
5014 Attribute_Name => Nam,
5015 Expressions => New_List (
5016 Make_Integer_Literal (Loc, Dim)));
5017 end Build_Attribute_Reference;
5019 -- Start of processing for Check_Subscripts
5022 for J in 1 .. Number_Dimensions (Typ) loop
5023 Evolve_And_Then (Cond,
5026 Build_Attribute_Reference
5027 (Duplicate_Subexpr_No_Checks (Obj),
5030 Build_Attribute_Reference
5031 (New_Occurrence_Of (Typ, Loc), Name_First, J)));
5033 Evolve_And_Then (Cond,
5036 Build_Attribute_Reference
5037 (Duplicate_Subexpr_No_Checks (Obj),
5040 Build_Attribute_Reference
5041 (New_Occurrence_Of (Typ, Loc), Name_Last, J)));
5050 Right_Opnd => Make_Null (Loc)),
5051 Right_Opnd => Cond);
5055 Analyze_And_Resolve (N, Restyp);
5056 end Check_Subscripts;
5058 -- These are the cases where constraint checks may be required,
5059 -- e.g. records with possible discriminants
5062 -- Expand the test into a series of discriminant comparisons.
5063 -- The expression that is built is the negation of the one that
5064 -- is used for checking discriminant constraints.
5066 Obj := Relocate_Node (Left_Opnd (N));
5068 if Has_Discriminants (Typ) then
5069 Cond := Make_Op_Not (Loc,
5070 Right_Opnd => Build_Discriminant_Checks (Obj, Typ));
5073 Cond := Make_Or_Else (Loc,
5077 Right_Opnd => Make_Null (Loc)),
5078 Right_Opnd => Cond);
5082 Cond := New_Occurrence_Of (Standard_True, Loc);
5086 Analyze_And_Resolve (N, Restyp);
5089 -- Ada 2012 (AI05-0149): Handle membership tests applied to an
5090 -- expression of an anonymous access type. This can involve an
5091 -- accessibility test and a tagged type membership test in the
5092 -- case of tagged designated types.
5094 if Ada_Version >= Ada_2012
5096 and then Ekind (Ltyp) = E_Anonymous_Access_Type
5099 Expr_Entity : Entity_Id := Empty;
5101 Param_Level : Node_Id;
5102 Type_Level : Node_Id;
5105 if Is_Entity_Name (Lop) then
5106 Expr_Entity := Param_Entity (Lop);
5108 if not Present (Expr_Entity) then
5109 Expr_Entity := Entity (Lop);
5113 -- If a conversion of the anonymous access value to the
5114 -- tested type would be illegal, then the result is False.
5116 if not Valid_Conversion
5117 (Lop, Rtyp, Lop, Report_Errs => False)
5119 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5120 Analyze_And_Resolve (N, Restyp);
5122 -- Apply an accessibility check if the access object has an
5123 -- associated access level and when the level of the type is
5124 -- less deep than the level of the access parameter. This
5125 -- only occur for access parameters and stand-alone objects
5126 -- of an anonymous access type.
5129 if Present (Expr_Entity)
5132 (Effective_Extra_Accessibility (Expr_Entity))
5133 and then UI_Gt (Object_Access_Level (Lop),
5134 Type_Access_Level (Rtyp))
5138 (Effective_Extra_Accessibility (Expr_Entity), Loc);
5141 Make_Integer_Literal (Loc, Type_Access_Level (Rtyp));
5143 -- Return True only if the accessibility level of the
5144 -- expression entity is not deeper than the level of
5145 -- the tested access type.
5149 Left_Opnd => Relocate_Node (N),
5150 Right_Opnd => Make_Op_Le (Loc,
5151 Left_Opnd => Param_Level,
5152 Right_Opnd => Type_Level)));
5154 Analyze_And_Resolve (N);
5157 -- If the designated type is tagged, do tagged membership
5160 -- *** NOTE: we have to check not null before doing the
5161 -- tagged membership test (but maybe that can be done
5162 -- inside Tagged_Membership?).
5164 if Is_Tagged_Type (Typ) then
5167 Left_Opnd => Relocate_Node (N),
5171 Right_Opnd => Make_Null (Loc))));
5173 -- No expansion will be performed when VM_Target, as
5174 -- the VM back-ends will handle the membership tests
5175 -- directly (tags are not explicitly represented in
5176 -- Java objects, so the normal tagged membership
5177 -- expansion is not what we want).
5179 if Tagged_Type_Expansion then
5181 -- Note that we have to pass Original_Node, because
5182 -- the membership test might already have been
5183 -- rewritten by earlier parts of membership test.
5186 (Original_Node (N), SCIL_Node, New_N);
5188 -- Update decoration of relocated node referenced
5189 -- by the SCIL node.
5191 if Generate_SCIL and then Present (SCIL_Node) then
5192 Set_SCIL_Node (New_N, SCIL_Node);
5197 Left_Opnd => Relocate_Node (N),
5198 Right_Opnd => New_N));
5200 Analyze_And_Resolve (N, Restyp);
5209 -- At this point, we have done the processing required for the basic
5210 -- membership test, but not yet dealt with the predicate.
5214 -- If a predicate is present, then we do the predicate test, but we
5215 -- most certainly want to omit this if we are within the predicate
5216 -- function itself, since otherwise we have an infinite recursion!
5219 PFunc : constant Entity_Id := Predicate_Function (Rtyp);
5223 and then Current_Scope /= PFunc
5227 Left_Opnd => Relocate_Node (N),
5228 Right_Opnd => Make_Predicate_Call (Rtyp, Lop)));
5230 -- Analyze new expression, mark left operand as analyzed to
5231 -- avoid infinite recursion adding predicate calls. Similarly,
5232 -- suppress further range checks on the call.
5234 Set_Analyzed (Left_Opnd (N));
5235 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
5237 -- All done, skip attempt at compile time determination of result
5244 --------------------------------
5245 -- Expand_N_Indexed_Component --
5246 --------------------------------
5248 procedure Expand_N_Indexed_Component (N : Node_Id) is
5249 Loc : constant Source_Ptr := Sloc (N);
5250 Typ : constant Entity_Id := Etype (N);
5251 P : constant Node_Id := Prefix (N);
5252 T : constant Entity_Id := Etype (P);
5256 -- A special optimization, if we have an indexed component that is
5257 -- selecting from a slice, then we can eliminate the slice, since, for
5258 -- example, x (i .. j)(k) is identical to x(k). The only difference is
5259 -- the range check required by the slice. The range check for the slice
5260 -- itself has already been generated. The range check for the
5261 -- subscripting operation is ensured by converting the subject to
5262 -- the subtype of the slice.
5264 -- This optimization not only generates better code, avoiding slice
5265 -- messing especially in the packed case, but more importantly bypasses
5266 -- some problems in handling this peculiar case, for example, the issue
5267 -- of dealing specially with object renamings.
5269 if Nkind (P) = N_Slice then
5271 Make_Indexed_Component (Loc,
5272 Prefix => Prefix (P),
5273 Expressions => New_List (
5275 (Etype (First_Index (Etype (P))),
5276 First (Expressions (N))))));
5277 Analyze_And_Resolve (N, Typ);
5281 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
5282 -- function, then additional actuals must be passed.
5284 if Ada_Version >= Ada_2005
5285 and then Is_Build_In_Place_Function_Call (P)
5287 Make_Build_In_Place_Call_In_Anonymous_Context (P);
5290 -- If the prefix is an access type, then we unconditionally rewrite if
5291 -- as an explicit dereference. This simplifies processing for several
5292 -- cases, including packed array cases and certain cases in which checks
5293 -- must be generated. We used to try to do this only when it was
5294 -- necessary, but it cleans up the code to do it all the time.
5296 if Is_Access_Type (T) then
5297 Insert_Explicit_Dereference (P);
5298 Analyze_And_Resolve (P, Designated_Type (T));
5299 Atp := Designated_Type (T);
5304 -- Generate index and validity checks
5306 Generate_Index_Checks (N);
5308 if Validity_Checks_On and then Validity_Check_Subscripts then
5309 Apply_Subscript_Validity_Checks (N);
5312 -- If selecting from an array with atomic components, and atomic sync
5313 -- is not suppressed for this array type, set atomic sync flag.
5315 if (Has_Atomic_Components (Atp)
5316 and then not Atomic_Synchronization_Disabled (Atp))
5317 or else (Is_Atomic (Typ)
5318 and then not Atomic_Synchronization_Disabled (Typ))
5320 Activate_Atomic_Synchronization (N);
5323 -- All done for the non-packed case
5325 if not Is_Packed (Etype (Prefix (N))) then
5329 -- For packed arrays that are not bit-packed (i.e. the case of an array
5330 -- with one or more index types with a non-contiguous enumeration type),
5331 -- we can always use the normal packed element get circuit.
5333 if not Is_Bit_Packed_Array (Etype (Prefix (N))) then
5334 Expand_Packed_Element_Reference (N);
5338 -- For a reference to a component of a bit packed array, we have to
5339 -- convert it to a reference to the corresponding Packed_Array_Type.
5340 -- We only want to do this for simple references, and not for:
5342 -- Left side of assignment, or prefix of left side of assignment, or
5343 -- prefix of the prefix, to handle packed arrays of packed arrays,
5344 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
5346 -- Renaming objects in renaming associations
5347 -- This case is handled when a use of the renamed variable occurs
5349 -- Actual parameters for a procedure call
5350 -- This case is handled in Exp_Ch6.Expand_Actuals
5352 -- The second expression in a 'Read attribute reference
5354 -- The prefix of an address or bit or size attribute reference
5356 -- The following circuit detects these exceptions
5359 Child : Node_Id := N;
5360 Parnt : Node_Id := Parent (N);
5364 if Nkind (Parnt) = N_Unchecked_Expression then
5367 elsif Nkind_In (Parnt, N_Object_Renaming_Declaration,
5368 N_Procedure_Call_Statement)
5369 or else (Nkind (Parnt) = N_Parameter_Association
5371 Nkind (Parent (Parnt)) = N_Procedure_Call_Statement)
5375 elsif Nkind (Parnt) = N_Attribute_Reference
5376 and then (Attribute_Name (Parnt) = Name_Address
5378 Attribute_Name (Parnt) = Name_Bit
5380 Attribute_Name (Parnt) = Name_Size)
5381 and then Prefix (Parnt) = Child
5385 elsif Nkind (Parnt) = N_Assignment_Statement
5386 and then Name (Parnt) = Child
5390 -- If the expression is an index of an indexed component, it must
5391 -- be expanded regardless of context.
5393 elsif Nkind (Parnt) = N_Indexed_Component
5394 and then Child /= Prefix (Parnt)
5396 Expand_Packed_Element_Reference (N);
5399 elsif Nkind (Parent (Parnt)) = N_Assignment_Statement
5400 and then Name (Parent (Parnt)) = Parnt
5404 elsif Nkind (Parnt) = N_Attribute_Reference
5405 and then Attribute_Name (Parnt) = Name_Read
5406 and then Next (First (Expressions (Parnt))) = Child
5410 elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component)
5411 and then Prefix (Parnt) = Child
5416 Expand_Packed_Element_Reference (N);
5420 -- Keep looking up tree for unchecked expression, or if we are the
5421 -- prefix of a possible assignment left side.
5424 Parnt := Parent (Child);
5427 end Expand_N_Indexed_Component;
5429 ---------------------
5430 -- Expand_N_Not_In --
5431 ---------------------
5433 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
5434 -- can be done. This avoids needing to duplicate this expansion code.
5436 procedure Expand_N_Not_In (N : Node_Id) is
5437 Loc : constant Source_Ptr := Sloc (N);
5438 Typ : constant Entity_Id := Etype (N);
5439 Cfs : constant Boolean := Comes_From_Source (N);
5446 Left_Opnd => Left_Opnd (N),
5447 Right_Opnd => Right_Opnd (N))));
5449 -- If this is a set membership, preserve list of alternatives
5451 Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N)));
5453 -- We want this to appear as coming from source if original does (see
5454 -- transformations in Expand_N_In).
5456 Set_Comes_From_Source (N, Cfs);
5457 Set_Comes_From_Source (Right_Opnd (N), Cfs);
5459 -- Now analyze transformed node
5461 Analyze_And_Resolve (N, Typ);
5462 end Expand_N_Not_In;
5468 -- The only replacement required is for the case of a null of a type that
5469 -- is an access to protected subprogram, or a subtype thereof. We represent
5470 -- such access values as a record, and so we must replace the occurrence of
5471 -- null by the equivalent record (with a null address and a null pointer in
5472 -- it), so that the backend creates the proper value.
5474 procedure Expand_N_Null (N : Node_Id) is
5475 Loc : constant Source_Ptr := Sloc (N);
5476 Typ : constant Entity_Id := Base_Type (Etype (N));
5480 if Is_Access_Protected_Subprogram_Type (Typ) then
5482 Make_Aggregate (Loc,
5483 Expressions => New_List (
5484 New_Occurrence_Of (RTE (RE_Null_Address), Loc),
5488 Analyze_And_Resolve (N, Equivalent_Type (Typ));
5490 -- For subsequent semantic analysis, the node must retain its type.
5491 -- Gigi in any case replaces this type by the corresponding record
5492 -- type before processing the node.
5498 when RE_Not_Available =>
5502 ---------------------
5503 -- Expand_N_Op_Abs --
5504 ---------------------
5506 procedure Expand_N_Op_Abs (N : Node_Id) is
5507 Loc : constant Source_Ptr := Sloc (N);
5508 Expr : constant Node_Id := Right_Opnd (N);
5511 Unary_Op_Validity_Checks (N);
5513 -- Deal with software overflow checking
5515 if not Backend_Overflow_Checks_On_Target
5516 and then Is_Signed_Integer_Type (Etype (N))
5517 and then Do_Overflow_Check (N)
5519 -- The only case to worry about is when the argument is equal to the
5520 -- largest negative number, so what we do is to insert the check:
5522 -- [constraint_error when Expr = typ'Base'First]
5524 -- with the usual Duplicate_Subexpr use coding for expr
5527 Make_Raise_Constraint_Error (Loc,
5530 Left_Opnd => Duplicate_Subexpr (Expr),
5532 Make_Attribute_Reference (Loc,
5534 New_Occurrence_Of (Base_Type (Etype (Expr)), Loc),
5535 Attribute_Name => Name_First)),
5536 Reason => CE_Overflow_Check_Failed));
5539 -- Vax floating-point types case
5541 if Vax_Float (Etype (N)) then
5542 Expand_Vax_Arith (N);
5544 end Expand_N_Op_Abs;
5546 ---------------------
5547 -- Expand_N_Op_Add --
5548 ---------------------
5550 procedure Expand_N_Op_Add (N : Node_Id) is
5551 Typ : constant Entity_Id := Etype (N);
5554 Binary_Op_Validity_Checks (N);
5556 -- N + 0 = 0 + N = N for integer types
5558 if Is_Integer_Type (Typ) then
5559 if Compile_Time_Known_Value (Right_Opnd (N))
5560 and then Expr_Value (Right_Opnd (N)) = Uint_0
5562 Rewrite (N, Left_Opnd (N));
5565 elsif Compile_Time_Known_Value (Left_Opnd (N))
5566 and then Expr_Value (Left_Opnd (N)) = Uint_0
5568 Rewrite (N, Right_Opnd (N));
5573 -- Arithmetic overflow checks for signed integer/fixed point types
5575 if Is_Signed_Integer_Type (Typ)
5576 or else Is_Fixed_Point_Type (Typ)
5578 Apply_Arithmetic_Overflow_Check (N);
5581 -- Vax floating-point types case
5583 elsif Vax_Float (Typ) then
5584 Expand_Vax_Arith (N);
5586 end Expand_N_Op_Add;
5588 ---------------------
5589 -- Expand_N_Op_And --
5590 ---------------------
5592 procedure Expand_N_Op_And (N : Node_Id) is
5593 Typ : constant Entity_Id := Etype (N);
5596 Binary_Op_Validity_Checks (N);
5598 if Is_Array_Type (Etype (N)) then
5599 Expand_Boolean_Operator (N);
5601 elsif Is_Boolean_Type (Etype (N)) then
5602 Adjust_Condition (Left_Opnd (N));
5603 Adjust_Condition (Right_Opnd (N));
5604 Set_Etype (N, Standard_Boolean);
5605 Adjust_Result_Type (N, Typ);
5607 elsif Is_Intrinsic_Subprogram (Entity (N)) then
5608 Expand_Intrinsic_Call (N, Entity (N));
5611 end Expand_N_Op_And;
5613 ------------------------
5614 -- Expand_N_Op_Concat --
5615 ------------------------
5617 procedure Expand_N_Op_Concat (N : Node_Id) is
5619 -- List of operands to be concatenated
5622 -- Node which is to be replaced by the result of concatenating the nodes
5623 -- in the list Opnds.
5626 -- Ensure validity of both operands
5628 Binary_Op_Validity_Checks (N);
5630 -- If we are the left operand of a concatenation higher up the tree,
5631 -- then do nothing for now, since we want to deal with a series of
5632 -- concatenations as a unit.
5634 if Nkind (Parent (N)) = N_Op_Concat
5635 and then N = Left_Opnd (Parent (N))
5640 -- We get here with a concatenation whose left operand may be a
5641 -- concatenation itself with a consistent type. We need to process
5642 -- these concatenation operands from left to right, which means
5643 -- from the deepest node in the tree to the highest node.
5646 while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop
5647 Cnode := Left_Opnd (Cnode);
5650 -- Now Cnode is the deepest concatenation, and its parents are the
5651 -- concatenation nodes above, so now we process bottom up, doing the
5652 -- operations. We gather a string that is as long as possible up to five
5655 -- The outer loop runs more than once if more than one concatenation
5656 -- type is involved.
5659 Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode));
5660 Set_Parent (Opnds, N);
5662 -- The inner loop gathers concatenation operands
5664 Inner : while Cnode /= N
5665 and then Base_Type (Etype (Cnode)) =
5666 Base_Type (Etype (Parent (Cnode)))
5668 Cnode := Parent (Cnode);
5669 Append (Right_Opnd (Cnode), Opnds);
5672 Expand_Concatenate (Cnode, Opnds);
5674 exit Outer when Cnode = N;
5675 Cnode := Parent (Cnode);
5677 end Expand_N_Op_Concat;
5679 ------------------------
5680 -- Expand_N_Op_Divide --
5681 ------------------------
5683 procedure Expand_N_Op_Divide (N : Node_Id) is
5684 Loc : constant Source_Ptr := Sloc (N);
5685 Lopnd : constant Node_Id := Left_Opnd (N);
5686 Ropnd : constant Node_Id := Right_Opnd (N);
5687 Ltyp : constant Entity_Id := Etype (Lopnd);
5688 Rtyp : constant Entity_Id := Etype (Ropnd);
5689 Typ : Entity_Id := Etype (N);
5690 Rknow : constant Boolean := Is_Integer_Type (Typ)
5692 Compile_Time_Known_Value (Ropnd);
5696 Binary_Op_Validity_Checks (N);
5699 Rval := Expr_Value (Ropnd);
5702 -- N / 1 = N for integer types
5704 if Rknow and then Rval = Uint_1 then
5709 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
5710 -- Is_Power_Of_2_For_Shift is set means that we know that our left
5711 -- operand is an unsigned integer, as required for this to work.
5713 if Nkind (Ropnd) = N_Op_Expon
5714 and then Is_Power_Of_2_For_Shift (Ropnd)
5716 -- We cannot do this transformation in configurable run time mode if we
5717 -- have 64-bit integers and long shifts are not available.
5721 or else Support_Long_Shifts_On_Target)
5724 Make_Op_Shift_Right (Loc,
5727 Convert_To (Standard_Natural, Right_Opnd (Ropnd))));
5728 Analyze_And_Resolve (N, Typ);
5732 -- Do required fixup of universal fixed operation
5734 if Typ = Universal_Fixed then
5735 Fixup_Universal_Fixed_Operation (N);
5739 -- Divisions with fixed-point results
5741 if Is_Fixed_Point_Type (Typ) then
5743 -- No special processing if Treat_Fixed_As_Integer is set, since
5744 -- from a semantic point of view such operations are simply integer
5745 -- operations and will be treated that way.
5747 if not Treat_Fixed_As_Integer (N) then
5748 if Is_Integer_Type (Rtyp) then
5749 Expand_Divide_Fixed_By_Integer_Giving_Fixed (N);
5751 Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N);
5755 -- Other cases of division of fixed-point operands. Again we exclude the
5756 -- case where Treat_Fixed_As_Integer is set.
5758 elsif (Is_Fixed_Point_Type (Ltyp) or else
5759 Is_Fixed_Point_Type (Rtyp))
5760 and then not Treat_Fixed_As_Integer (N)
5762 if Is_Integer_Type (Typ) then
5763 Expand_Divide_Fixed_By_Fixed_Giving_Integer (N);
5765 pragma Assert (Is_Floating_Point_Type (Typ));
5766 Expand_Divide_Fixed_By_Fixed_Giving_Float (N);
5769 -- Mixed-mode operations can appear in a non-static universal context,
5770 -- in which case the integer argument must be converted explicitly.
5772 elsif Typ = Universal_Real
5773 and then Is_Integer_Type (Rtyp)
5776 Convert_To (Universal_Real, Relocate_Node (Ropnd)));
5778 Analyze_And_Resolve (Ropnd, Universal_Real);
5780 elsif Typ = Universal_Real
5781 and then Is_Integer_Type (Ltyp)
5784 Convert_To (Universal_Real, Relocate_Node (Lopnd)));
5786 Analyze_And_Resolve (Lopnd, Universal_Real);
5788 -- Non-fixed point cases, do integer zero divide and overflow checks
5790 elsif Is_Integer_Type (Typ) then
5791 Apply_Divide_Check (N);
5793 -- Deal with Vax_Float
5795 elsif Vax_Float (Typ) then
5796 Expand_Vax_Arith (N);
5799 end Expand_N_Op_Divide;
5801 --------------------
5802 -- Expand_N_Op_Eq --
5803 --------------------
5805 procedure Expand_N_Op_Eq (N : Node_Id) is
5806 Loc : constant Source_Ptr := Sloc (N);
5807 Typ : constant Entity_Id := Etype (N);
5808 Lhs : constant Node_Id := Left_Opnd (N);
5809 Rhs : constant Node_Id := Right_Opnd (N);
5810 Bodies : constant List_Id := New_List;
5811 A_Typ : constant Entity_Id := Etype (Lhs);
5813 Typl : Entity_Id := A_Typ;
5814 Op_Name : Entity_Id;
5817 procedure Build_Equality_Call (Eq : Entity_Id);
5818 -- If a constructed equality exists for the type or for its parent,
5819 -- build and analyze call, adding conversions if the operation is
5822 function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
5823 -- Determines whether a type has a subcomponent of an unconstrained
5824 -- Unchecked_Union subtype. Typ is a record type.
5826 -------------------------
5827 -- Build_Equality_Call --
5828 -------------------------
5830 procedure Build_Equality_Call (Eq : Entity_Id) is
5831 Op_Type : constant Entity_Id := Etype (First_Formal (Eq));
5832 L_Exp : Node_Id := Relocate_Node (Lhs);
5833 R_Exp : Node_Id := Relocate_Node (Rhs);
5836 if Base_Type (Op_Type) /= Base_Type (A_Typ)
5837 and then not Is_Class_Wide_Type (A_Typ)
5839 L_Exp := OK_Convert_To (Op_Type, L_Exp);
5840 R_Exp := OK_Convert_To (Op_Type, R_Exp);
5843 -- If we have an Unchecked_Union, we need to add the inferred
5844 -- discriminant values as actuals in the function call. At this
5845 -- point, the expansion has determined that both operands have
5846 -- inferable discriminants.
5848 if Is_Unchecked_Union (Op_Type) then
5850 Lhs_Type : constant Node_Id := Etype (L_Exp);
5851 Rhs_Type : constant Node_Id := Etype (R_Exp);
5852 Lhs_Discr_Val : Node_Id;
5853 Rhs_Discr_Val : Node_Id;
5856 -- Per-object constrained selected components require special
5857 -- attention. If the enclosing scope of the component is an
5858 -- Unchecked_Union, we cannot reference its discriminants
5859 -- directly. This is why we use the two extra parameters of
5860 -- the equality function of the enclosing Unchecked_Union.
5862 -- type UU_Type (Discr : Integer := 0) is
5865 -- pragma Unchecked_Union (UU_Type);
5867 -- 1. Unchecked_Union enclosing record:
5869 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
5871 -- Comp : UU_Type (Discr);
5873 -- end Enclosing_UU_Type;
5874 -- pragma Unchecked_Union (Enclosing_UU_Type);
5876 -- Obj1 : Enclosing_UU_Type;
5877 -- Obj2 : Enclosing_UU_Type (1);
5879 -- [. . .] Obj1 = Obj2 [. . .]
5883 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
5885 -- A and B are the formal parameters of the equality function
5886 -- of Enclosing_UU_Type. The function always has two extra
5887 -- formals to capture the inferred discriminant values.
5889 -- 2. Non-Unchecked_Union enclosing record:
5892 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
5895 -- Comp : UU_Type (Discr);
5897 -- end Enclosing_Non_UU_Type;
5899 -- Obj1 : Enclosing_Non_UU_Type;
5900 -- Obj2 : Enclosing_Non_UU_Type (1);
5902 -- ... Obj1 = Obj2 ...
5906 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
5907 -- obj1.discr, obj2.discr)) then
5909 -- In this case we can directly reference the discriminants of
5910 -- the enclosing record.
5914 if Nkind (Lhs) = N_Selected_Component
5915 and then Has_Per_Object_Constraint
5916 (Entity (Selector_Name (Lhs)))
5918 -- Enclosing record is an Unchecked_Union, use formal A
5920 if Is_Unchecked_Union
5921 (Scope (Entity (Selector_Name (Lhs))))
5923 Lhs_Discr_Val := Make_Identifier (Loc, Name_A);
5925 -- Enclosing record is of a non-Unchecked_Union type, it is
5926 -- possible to reference the discriminant.
5930 Make_Selected_Component (Loc,
5931 Prefix => Prefix (Lhs),
5934 (Get_Discriminant_Value
5935 (First_Discriminant (Lhs_Type),
5937 Stored_Constraint (Lhs_Type))));
5940 -- Comment needed here ???
5943 -- Infer the discriminant value
5947 (Get_Discriminant_Value
5948 (First_Discriminant (Lhs_Type),
5950 Stored_Constraint (Lhs_Type)));
5955 if Nkind (Rhs) = N_Selected_Component
5956 and then Has_Per_Object_Constraint
5957 (Entity (Selector_Name (Rhs)))
5959 if Is_Unchecked_Union
5960 (Scope (Entity (Selector_Name (Rhs))))
5962 Rhs_Discr_Val := Make_Identifier (Loc, Name_B);
5966 Make_Selected_Component (Loc,
5967 Prefix => Prefix (Rhs),
5969 New_Copy (Get_Discriminant_Value (
5970 First_Discriminant (Rhs_Type),
5972 Stored_Constraint (Rhs_Type))));
5977 New_Copy (Get_Discriminant_Value (
5978 First_Discriminant (Rhs_Type),
5980 Stored_Constraint (Rhs_Type)));
5985 Make_Function_Call (Loc,
5986 Name => New_Reference_To (Eq, Loc),
5987 Parameter_Associations => New_List (
5994 -- Normal case, not an unchecked union
5998 Make_Function_Call (Loc,
5999 Name => New_Reference_To (Eq, Loc),
6000 Parameter_Associations => New_List (L_Exp, R_Exp)));
6003 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6004 end Build_Equality_Call;
6006 ------------------------------------
6007 -- Has_Unconstrained_UU_Component --
6008 ------------------------------------
6010 function Has_Unconstrained_UU_Component
6011 (Typ : Node_Id) return Boolean
6013 Tdef : constant Node_Id :=
6014 Type_Definition (Declaration_Node (Base_Type (Typ)));
6018 function Component_Is_Unconstrained_UU
6019 (Comp : Node_Id) return Boolean;
6020 -- Determines whether the subtype of the component is an
6021 -- unconstrained Unchecked_Union.
6023 function Variant_Is_Unconstrained_UU
6024 (Variant : Node_Id) return Boolean;
6025 -- Determines whether a component of the variant has an unconstrained
6026 -- Unchecked_Union subtype.
6028 -----------------------------------
6029 -- Component_Is_Unconstrained_UU --
6030 -----------------------------------
6032 function Component_Is_Unconstrained_UU
6033 (Comp : Node_Id) return Boolean
6036 if Nkind (Comp) /= N_Component_Declaration then
6041 Sindic : constant Node_Id :=
6042 Subtype_Indication (Component_Definition (Comp));
6045 -- Unconstrained nominal type. In the case of a constraint
6046 -- present, the node kind would have been N_Subtype_Indication.
6048 if Nkind (Sindic) = N_Identifier then
6049 return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
6054 end Component_Is_Unconstrained_UU;
6056 ---------------------------------
6057 -- Variant_Is_Unconstrained_UU --
6058 ---------------------------------
6060 function Variant_Is_Unconstrained_UU
6061 (Variant : Node_Id) return Boolean
6063 Clist : constant Node_Id := Component_List (Variant);
6066 if Is_Empty_List (Component_Items (Clist)) then
6070 -- We only need to test one component
6073 Comp : Node_Id := First (Component_Items (Clist));
6076 while Present (Comp) loop
6077 if Component_Is_Unconstrained_UU (Comp) then
6085 -- None of the components withing the variant were of
6086 -- unconstrained Unchecked_Union type.
6089 end Variant_Is_Unconstrained_UU;
6091 -- Start of processing for Has_Unconstrained_UU_Component
6094 if Null_Present (Tdef) then
6098 Clist := Component_List (Tdef);
6099 Vpart := Variant_Part (Clist);
6101 -- Inspect available components
6103 if Present (Component_Items (Clist)) then
6105 Comp : Node_Id := First (Component_Items (Clist));
6108 while Present (Comp) loop
6110 -- One component is sufficient
6112 if Component_Is_Unconstrained_UU (Comp) then
6121 -- Inspect available components withing variants
6123 if Present (Vpart) then
6125 Variant : Node_Id := First (Variants (Vpart));
6128 while Present (Variant) loop
6130 -- One component within a variant is sufficient
6132 if Variant_Is_Unconstrained_UU (Variant) then
6141 -- Neither the available components, nor the components inside the
6142 -- variant parts were of an unconstrained Unchecked_Union subtype.
6145 end Has_Unconstrained_UU_Component;
6147 -- Start of processing for Expand_N_Op_Eq
6150 Binary_Op_Validity_Checks (N);
6152 if Ekind (Typl) = E_Private_Type then
6153 Typl := Underlying_Type (Typl);
6154 elsif Ekind (Typl) = E_Private_Subtype then
6155 Typl := Underlying_Type (Base_Type (Typl));
6160 -- It may happen in error situations that the underlying type is not
6161 -- set. The error will be detected later, here we just defend the
6168 Typl := Base_Type (Typl);
6170 -- Boolean types (requiring handling of non-standard case)
6172 if Is_Boolean_Type (Typl) then
6173 Adjust_Condition (Left_Opnd (N));
6174 Adjust_Condition (Right_Opnd (N));
6175 Set_Etype (N, Standard_Boolean);
6176 Adjust_Result_Type (N, Typ);
6180 elsif Is_Array_Type (Typl) then
6182 -- If we are doing full validity checking, and it is possible for the
6183 -- array elements to be invalid then expand out array comparisons to
6184 -- make sure that we check the array elements.
6186 if Validity_Check_Operands
6187 and then not Is_Known_Valid (Component_Type (Typl))
6190 Save_Force_Validity_Checks : constant Boolean :=
6191 Force_Validity_Checks;
6193 Force_Validity_Checks := True;
6195 Expand_Array_Equality
6197 Relocate_Node (Lhs),
6198 Relocate_Node (Rhs),
6201 Insert_Actions (N, Bodies);
6202 Analyze_And_Resolve (N, Standard_Boolean);
6203 Force_Validity_Checks := Save_Force_Validity_Checks;
6206 -- Packed case where both operands are known aligned
6208 elsif Is_Bit_Packed_Array (Typl)
6209 and then not Is_Possibly_Unaligned_Object (Lhs)
6210 and then not Is_Possibly_Unaligned_Object (Rhs)
6212 Expand_Packed_Eq (N);
6214 -- Where the component type is elementary we can use a block bit
6215 -- comparison (if supported on the target) exception in the case
6216 -- of floating-point (negative zero issues require element by
6217 -- element comparison), and atomic types (where we must be sure
6218 -- to load elements independently) and possibly unaligned arrays.
6220 elsif Is_Elementary_Type (Component_Type (Typl))
6221 and then not Is_Floating_Point_Type (Component_Type (Typl))
6222 and then not Is_Atomic (Component_Type (Typl))
6223 and then not Is_Possibly_Unaligned_Object (Lhs)
6224 and then not Is_Possibly_Unaligned_Object (Rhs)
6225 and then Support_Composite_Compare_On_Target
6229 -- For composite and floating-point cases, expand equality loop to
6230 -- make sure of using proper comparisons for tagged types, and
6231 -- correctly handling the floating-point case.
6235 Expand_Array_Equality
6237 Relocate_Node (Lhs),
6238 Relocate_Node (Rhs),
6241 Insert_Actions (N, Bodies, Suppress => All_Checks);
6242 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6247 elsif Is_Record_Type (Typl) then
6249 -- For tagged types, use the primitive "="
6251 if Is_Tagged_Type (Typl) then
6253 -- No need to do anything else compiling under restriction
6254 -- No_Dispatching_Calls. During the semantic analysis we
6255 -- already notified such violation.
6257 if Restriction_Active (No_Dispatching_Calls) then
6261 -- If this is derived from an untagged private type completed with
6262 -- a tagged type, it does not have a full view, so we use the
6263 -- primitive operations of the private type. This check should no
6264 -- longer be necessary when these types get their full views???
6266 if Is_Private_Type (A_Typ)
6267 and then not Is_Tagged_Type (A_Typ)
6268 and then Is_Derived_Type (A_Typ)
6269 and then No (Full_View (A_Typ))
6271 -- Search for equality operation, checking that the operands
6272 -- have the same type. Note that we must find a matching entry,
6273 -- or something is very wrong!
6275 Prim := First_Elmt (Collect_Primitive_Operations (A_Typ));
6277 while Present (Prim) loop
6278 exit when Chars (Node (Prim)) = Name_Op_Eq
6279 and then Etype (First_Formal (Node (Prim))) =
6280 Etype (Next_Formal (First_Formal (Node (Prim))))
6282 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6287 pragma Assert (Present (Prim));
6288 Op_Name := Node (Prim);
6290 -- Find the type's predefined equality or an overriding
6291 -- user- defined equality. The reason for not simply calling
6292 -- Find_Prim_Op here is that there may be a user-defined
6293 -- overloaded equality op that precedes the equality that we want,
6294 -- so we have to explicitly search (e.g., there could be an
6295 -- equality with two different parameter types).
6298 if Is_Class_Wide_Type (Typl) then
6299 Typl := Root_Type (Typl);
6302 Prim := First_Elmt (Primitive_Operations (Typl));
6303 while Present (Prim) loop
6304 exit when Chars (Node (Prim)) = Name_Op_Eq
6305 and then Etype (First_Formal (Node (Prim))) =
6306 Etype (Next_Formal (First_Formal (Node (Prim))))
6308 Base_Type (Etype (Node (Prim))) = Standard_Boolean;
6313 pragma Assert (Present (Prim));
6314 Op_Name := Node (Prim);
6317 Build_Equality_Call (Op_Name);
6319 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
6320 -- predefined equality operator for a type which has a subcomponent
6321 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
6323 elsif Has_Unconstrained_UU_Component (Typl) then
6325 Make_Raise_Program_Error (Loc,
6326 Reason => PE_Unchecked_Union_Restriction));
6328 -- Prevent Gigi from generating incorrect code by rewriting the
6329 -- equality as a standard False.
6332 New_Occurrence_Of (Standard_False, Loc));
6334 elsif Is_Unchecked_Union (Typl) then
6336 -- If we can infer the discriminants of the operands, we make a
6337 -- call to the TSS equality function.
6339 if Has_Inferable_Discriminants (Lhs)
6341 Has_Inferable_Discriminants (Rhs)
6344 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6347 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
6348 -- the predefined equality operator for an Unchecked_Union type
6349 -- if either of the operands lack inferable discriminants.
6352 Make_Raise_Program_Error (Loc,
6353 Reason => PE_Unchecked_Union_Restriction));
6355 -- Prevent Gigi from generating incorrect code by rewriting
6356 -- the equality as a standard False.
6359 New_Occurrence_Of (Standard_False, Loc));
6363 -- If a type support function is present (for complex cases), use it
6365 elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
6367 (TSS (Root_Type (Typl), TSS_Composite_Equality));
6369 -- Otherwise expand the component by component equality. Note that
6370 -- we never use block-bit comparisons for records, because of the
6371 -- problems with gaps. The backend will often be able to recombine
6372 -- the separate comparisons that we generate here.
6375 Remove_Side_Effects (Lhs);
6376 Remove_Side_Effects (Rhs);
6378 Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies));
6380 Insert_Actions (N, Bodies, Suppress => All_Checks);
6381 Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
6385 -- Test if result is known at compile time
6387 Rewrite_Comparison (N);
6389 -- If we still have comparison for Vax_Float, process it
6391 if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then
6392 Expand_Vax_Comparison (N);
6396 Optimize_Length_Comparison (N);
6399 -----------------------
6400 -- Expand_N_Op_Expon --
6401 -----------------------
6403 procedure Expand_N_Op_Expon (N : Node_Id) is
6404 Loc : constant Source_Ptr := Sloc (N);
6405 Typ : constant Entity_Id := Etype (N);
6406 Rtyp : constant Entity_Id := Root_Type (Typ);
6407 Base : constant Node_Id := Relocate_Node (Left_Opnd (N));
6408 Bastyp : constant Node_Id := Etype (Base);
6409 Exp : constant Node_Id := Relocate_Node (Right_Opnd (N));
6410 Exptyp : constant Entity_Id := Etype (Exp);
6411 Ovflo : constant Boolean := Do_Overflow_Check (N);
6420 Binary_Op_Validity_Checks (N);
6422 -- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node
6424 if CodePeer_Mode or Alfa_Mode then
6428 -- If either operand is of a private type, then we have the use of an
6429 -- intrinsic operator, and we get rid of the privateness, by using root
6430 -- types of underlying types for the actual operation. Otherwise the
6431 -- private types will cause trouble if we expand multiplications or
6432 -- shifts etc. We also do this transformation if the result type is
6433 -- different from the base type.
6435 if Is_Private_Type (Etype (Base))
6436 or else Is_Private_Type (Typ)
6437 or else Is_Private_Type (Exptyp)
6438 or else Rtyp /= Root_Type (Bastyp)
6441 Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp));
6442 Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp));
6446 Unchecked_Convert_To (Typ,
6448 Left_Opnd => Unchecked_Convert_To (Bt, Base),
6449 Right_Opnd => Unchecked_Convert_To (Et, Exp))));
6450 Analyze_And_Resolve (N, Typ);
6455 -- Test for case of known right argument
6457 if Compile_Time_Known_Value (Exp) then
6458 Expv := Expr_Value (Exp);
6460 -- We only fold small non-negative exponents. You might think we
6461 -- could fold small negative exponents for the real case, but we
6462 -- can't because we are required to raise Constraint_Error for
6463 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
6464 -- See ACVC test C4A012B.
6466 if Expv >= 0 and then Expv <= 4 then
6468 -- X ** 0 = 1 (or 1.0)
6472 -- Call Remove_Side_Effects to ensure that any side effects
6473 -- in the ignored left operand (in particular function calls
6474 -- to user defined functions) are properly executed.
6476 Remove_Side_Effects (Base);
6478 if Ekind (Typ) in Integer_Kind then
6479 Xnode := Make_Integer_Literal (Loc, Intval => 1);
6481 Xnode := Make_Real_Literal (Loc, Ureal_1);
6493 Make_Op_Multiply (Loc,
6494 Left_Opnd => Duplicate_Subexpr (Base),
6495 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6497 -- X ** 3 = X * X * X
6501 Make_Op_Multiply (Loc,
6503 Make_Op_Multiply (Loc,
6504 Left_Opnd => Duplicate_Subexpr (Base),
6505 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)),
6506 Right_Opnd => Duplicate_Subexpr_No_Checks (Base));
6509 -- En : constant base'type := base * base;
6514 Temp := Make_Temporary (Loc, 'E', Base);
6516 Insert_Actions (N, New_List (
6517 Make_Object_Declaration (Loc,
6518 Defining_Identifier => Temp,
6519 Constant_Present => True,
6520 Object_Definition => New_Reference_To (Typ, Loc),
6522 Make_Op_Multiply (Loc,
6523 Left_Opnd => Duplicate_Subexpr (Base),
6524 Right_Opnd => Duplicate_Subexpr_No_Checks (Base)))));
6527 Make_Op_Multiply (Loc,
6528 Left_Opnd => New_Reference_To (Temp, Loc),
6529 Right_Opnd => New_Reference_To (Temp, Loc));
6533 Analyze_And_Resolve (N, Typ);
6538 -- Case of (2 ** expression) appearing as an argument of an integer
6539 -- multiplication, or as the right argument of a division of a non-
6540 -- negative integer. In such cases we leave the node untouched, setting
6541 -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion
6542 -- of the higher level node converts it into a shift.
6544 -- Another case is 2 ** N in any other context. We simply convert
6545 -- this to 1 * 2 ** N, and then the above transformation applies.
6547 -- Note: this transformation is not applicable for a modular type with
6548 -- a non-binary modulus in the multiplication case, since we get a wrong
6549 -- result if the shift causes an overflow before the modular reduction.
6551 if Nkind (Base) = N_Integer_Literal
6552 and then Intval (Base) = 2
6553 and then Is_Integer_Type (Root_Type (Exptyp))
6554 and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer)
6555 and then Is_Unsigned_Type (Exptyp)
6558 -- First the multiply and divide cases
6560 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
6562 P : constant Node_Id := Parent (N);
6563 L : constant Node_Id := Left_Opnd (P);
6564 R : constant Node_Id := Right_Opnd (P);
6567 if (Nkind (P) = N_Op_Multiply
6568 and then not Non_Binary_Modulus (Typ)
6570 ((Is_Integer_Type (Etype (L)) and then R = N)
6572 (Is_Integer_Type (Etype (R)) and then L = N))
6573 and then not Do_Overflow_Check (P))
6575 (Nkind (P) = N_Op_Divide
6576 and then Is_Integer_Type (Etype (L))
6577 and then Is_Unsigned_Type (Etype (L))
6579 and then not Do_Overflow_Check (P))
6581 Set_Is_Power_Of_2_For_Shift (N);
6586 -- Now the other cases
6588 elsif not Non_Binary_Modulus (Typ) then
6590 Make_Op_Multiply (Loc,
6591 Left_Opnd => Make_Integer_Literal (Loc, 1),
6592 Right_Opnd => Relocate_Node (N)));
6593 Analyze_And_Resolve (N, Typ);
6598 -- Fall through if exponentiation must be done using a runtime routine
6600 -- First deal with modular case
6602 if Is_Modular_Integer_Type (Rtyp) then
6604 -- Non-binary case, we call the special exponentiation routine for
6605 -- the non-binary case, converting the argument to Long_Long_Integer
6606 -- and passing the modulus value. Then the result is converted back
6607 -- to the base type.
6609 if Non_Binary_Modulus (Rtyp) then
6612 Make_Function_Call (Loc,
6613 Name => New_Reference_To (RTE (RE_Exp_Modular), Loc),
6614 Parameter_Associations => New_List (
6615 Convert_To (Standard_Integer, Base),
6616 Make_Integer_Literal (Loc, Modulus (Rtyp)),
6619 -- Binary case, in this case, we call one of two routines, either the
6620 -- unsigned integer case, or the unsigned long long integer case,
6621 -- with a final "and" operation to do the required mod.
6624 if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then
6625 Ent := RTE (RE_Exp_Unsigned);
6627 Ent := RTE (RE_Exp_Long_Long_Unsigned);
6634 Make_Function_Call (Loc,
6635 Name => New_Reference_To (Ent, Loc),
6636 Parameter_Associations => New_List (
6637 Convert_To (Etype (First_Formal (Ent)), Base),
6640 Make_Integer_Literal (Loc, Modulus (Rtyp) - 1))));
6644 -- Common exit point for modular type case
6646 Analyze_And_Resolve (N, Typ);
6649 -- Signed integer cases, done using either Integer or Long_Long_Integer.
6650 -- It is not worth having routines for Short_[Short_]Integer, since for
6651 -- most machines it would not help, and it would generate more code that
6652 -- might need certification when a certified run time is required.
6654 -- In the integer cases, we have two routines, one for when overflow
6655 -- checks are required, and one when they are not required, since there
6656 -- is a real gain in omitting checks on many machines.
6658 elsif Rtyp = Base_Type (Standard_Long_Long_Integer)
6659 or else (Rtyp = Base_Type (Standard_Long_Integer)
6661 Esize (Standard_Long_Integer) > Esize (Standard_Integer))
6662 or else (Rtyp = Universal_Integer)
6664 Etyp := Standard_Long_Long_Integer;
6667 Rent := RE_Exp_Long_Long_Integer;
6669 Rent := RE_Exn_Long_Long_Integer;
6672 elsif Is_Signed_Integer_Type (Rtyp) then
6673 Etyp := Standard_Integer;
6676 Rent := RE_Exp_Integer;
6678 Rent := RE_Exn_Integer;
6681 -- Floating-point cases, always done using Long_Long_Float. We do not
6682 -- need separate routines for the overflow case here, since in the case
6683 -- of floating-point, we generate infinities anyway as a rule (either
6684 -- that or we automatically trap overflow), and if there is an infinity
6685 -- generated and a range check is required, the check will fail anyway.
6688 pragma Assert (Is_Floating_Point_Type (Rtyp));
6689 Etyp := Standard_Long_Long_Float;
6690 Rent := RE_Exn_Long_Long_Float;
6693 -- Common processing for integer cases and floating-point cases.
6694 -- If we are in the right type, we can call runtime routine directly
6697 and then Rtyp /= Universal_Integer
6698 and then Rtyp /= Universal_Real
6701 Make_Function_Call (Loc,
6702 Name => New_Reference_To (RTE (Rent), Loc),
6703 Parameter_Associations => New_List (Base, Exp)));
6705 -- Otherwise we have to introduce conversions (conversions are also
6706 -- required in the universal cases, since the runtime routine is
6707 -- typed using one of the standard types).
6712 Make_Function_Call (Loc,
6713 Name => New_Reference_To (RTE (Rent), Loc),
6714 Parameter_Associations => New_List (
6715 Convert_To (Etyp, Base),
6719 Analyze_And_Resolve (N, Typ);
6723 when RE_Not_Available =>
6725 end Expand_N_Op_Expon;
6727 --------------------
6728 -- Expand_N_Op_Ge --
6729 --------------------
6731 procedure Expand_N_Op_Ge (N : Node_Id) is
6732 Typ : constant Entity_Id := Etype (N);
6733 Op1 : constant Node_Id := Left_Opnd (N);
6734 Op2 : constant Node_Id := Right_Opnd (N);
6735 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6738 Binary_Op_Validity_Checks (N);
6740 if Is_Array_Type (Typ1) then
6741 Expand_Array_Comparison (N);
6745 if Is_Boolean_Type (Typ1) then
6746 Adjust_Condition (Op1);
6747 Adjust_Condition (Op2);
6748 Set_Etype (N, Standard_Boolean);
6749 Adjust_Result_Type (N, Typ);
6752 Rewrite_Comparison (N);
6754 -- If we still have comparison, and Vax_Float type, process it
6756 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6757 Expand_Vax_Comparison (N);
6761 Optimize_Length_Comparison (N);
6764 --------------------
6765 -- Expand_N_Op_Gt --
6766 --------------------
6768 procedure Expand_N_Op_Gt (N : Node_Id) is
6769 Typ : constant Entity_Id := Etype (N);
6770 Op1 : constant Node_Id := Left_Opnd (N);
6771 Op2 : constant Node_Id := Right_Opnd (N);
6772 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6775 Binary_Op_Validity_Checks (N);
6777 if Is_Array_Type (Typ1) then
6778 Expand_Array_Comparison (N);
6782 if Is_Boolean_Type (Typ1) then
6783 Adjust_Condition (Op1);
6784 Adjust_Condition (Op2);
6785 Set_Etype (N, Standard_Boolean);
6786 Adjust_Result_Type (N, Typ);
6789 Rewrite_Comparison (N);
6791 -- If we still have comparison, and Vax_Float type, process it
6793 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6794 Expand_Vax_Comparison (N);
6798 Optimize_Length_Comparison (N);
6801 --------------------
6802 -- Expand_N_Op_Le --
6803 --------------------
6805 procedure Expand_N_Op_Le (N : Node_Id) is
6806 Typ : constant Entity_Id := Etype (N);
6807 Op1 : constant Node_Id := Left_Opnd (N);
6808 Op2 : constant Node_Id := Right_Opnd (N);
6809 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6812 Binary_Op_Validity_Checks (N);
6814 if Is_Array_Type (Typ1) then
6815 Expand_Array_Comparison (N);
6819 if Is_Boolean_Type (Typ1) then
6820 Adjust_Condition (Op1);
6821 Adjust_Condition (Op2);
6822 Set_Etype (N, Standard_Boolean);
6823 Adjust_Result_Type (N, Typ);
6826 Rewrite_Comparison (N);
6828 -- If we still have comparison, and Vax_Float type, process it
6830 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6831 Expand_Vax_Comparison (N);
6835 Optimize_Length_Comparison (N);
6838 --------------------
6839 -- Expand_N_Op_Lt --
6840 --------------------
6842 procedure Expand_N_Op_Lt (N : Node_Id) is
6843 Typ : constant Entity_Id := Etype (N);
6844 Op1 : constant Node_Id := Left_Opnd (N);
6845 Op2 : constant Node_Id := Right_Opnd (N);
6846 Typ1 : constant Entity_Id := Base_Type (Etype (Op1));
6849 Binary_Op_Validity_Checks (N);
6851 if Is_Array_Type (Typ1) then
6852 Expand_Array_Comparison (N);
6856 if Is_Boolean_Type (Typ1) then
6857 Adjust_Condition (Op1);
6858 Adjust_Condition (Op2);
6859 Set_Etype (N, Standard_Boolean);
6860 Adjust_Result_Type (N, Typ);
6863 Rewrite_Comparison (N);
6865 -- If we still have comparison, and Vax_Float type, process it
6867 if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then
6868 Expand_Vax_Comparison (N);
6872 Optimize_Length_Comparison (N);
6875 -----------------------
6876 -- Expand_N_Op_Minus --
6877 -----------------------
6879 procedure Expand_N_Op_Minus (N : Node_Id) is
6880 Loc : constant Source_Ptr := Sloc (N);
6881 Typ : constant Entity_Id := Etype (N);
6884 Unary_Op_Validity_Checks (N);
6886 if not Backend_Overflow_Checks_On_Target
6887 and then Is_Signed_Integer_Type (Etype (N))
6888 and then Do_Overflow_Check (N)
6890 -- Software overflow checking expands -expr into (0 - expr)
6893 Make_Op_Subtract (Loc,
6894 Left_Opnd => Make_Integer_Literal (Loc, 0),
6895 Right_Opnd => Right_Opnd (N)));
6897 Analyze_And_Resolve (N, Typ);
6899 -- Vax floating-point types case
6901 elsif Vax_Float (Etype (N)) then
6902 Expand_Vax_Arith (N);
6904 end Expand_N_Op_Minus;
6906 ---------------------
6907 -- Expand_N_Op_Mod --
6908 ---------------------
6910 procedure Expand_N_Op_Mod (N : Node_Id) is
6911 Loc : constant Source_Ptr := Sloc (N);
6912 Typ : constant Entity_Id := Etype (N);
6913 Left : constant Node_Id := Left_Opnd (N);
6914 Right : constant Node_Id := Right_Opnd (N);
6915 DOC : constant Boolean := Do_Overflow_Check (N);
6916 DDC : constant Boolean := Do_Division_Check (N);
6926 pragma Warnings (Off, Lhi);
6929 Binary_Op_Validity_Checks (N);
6931 Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True);
6932 Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True);
6934 -- Convert mod to rem if operands are known non-negative. We do this
6935 -- since it is quite likely that this will improve the quality of code,
6936 -- (the operation now corresponds to the hardware remainder), and it
6937 -- does not seem likely that it could be harmful.
6939 if LOK and then Llo >= 0
6941 ROK and then Rlo >= 0
6944 Make_Op_Rem (Sloc (N),
6945 Left_Opnd => Left_Opnd (N),
6946 Right_Opnd => Right_Opnd (N)));
6948 -- Instead of reanalyzing the node we do the analysis manually. This
6949 -- avoids anomalies when the replacement is done in an instance and
6950 -- is epsilon more efficient.
6952 Set_Entity (N, Standard_Entity (S_Op_Rem));
6954 Set_Do_Overflow_Check (N, DOC);
6955 Set_Do_Division_Check (N, DDC);
6956 Expand_N_Op_Rem (N);
6959 -- Otherwise, normal mod processing
6962 if Is_Integer_Type (Etype (N)) then
6963 Apply_Divide_Check (N);
6966 -- Apply optimization x mod 1 = 0. We don't really need that with
6967 -- gcc, but it is useful with other back ends (e.g. AAMP), and is
6968 -- certainly harmless.
6970 if Is_Integer_Type (Etype (N))
6971 and then Compile_Time_Known_Value (Right)
6972 and then Expr_Value (Right) = Uint_1
6974 -- Call Remove_Side_Effects to ensure that any side effects in
6975 -- the ignored left operand (in particular function calls to
6976 -- user defined functions) are properly executed.
6978 Remove_Side_Effects (Left);
6980 Rewrite (N, Make_Integer_Literal (Loc, 0));
6981 Analyze_And_Resolve (N, Typ);
6985 -- Deal with annoying case of largest negative number remainder
6986 -- minus one. Gigi does not handle this case correctly, because
6987 -- it generates a divide instruction which may trap in this case.
6989 -- In fact the check is quite easy, if the right operand is -1, then
6990 -- the mod value is always 0, and we can just ignore the left operand
6991 -- completely in this case.
6993 -- The operand type may be private (e.g. in the expansion of an
6994 -- intrinsic operation) so we must use the underlying type to get the
6995 -- bounds, and convert the literals explicitly.
6999 (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left)))));
7001 if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi))
7003 ((not LOK) or else (Llo = LLB))
7006 Make_Conditional_Expression (Loc,
7007 Expressions => New_List (
7009 Left_Opnd => Duplicate_Subexpr (Right),
7011 Unchecked_Convert_To (Typ,
7012 Make_Integer_Literal (Loc, -1))),
7013 Unchecked_Convert_To (Typ,
7014 Make_Integer_Literal (Loc, Uint_0)),
7015 Relocate_Node (N))));
7017 Set_Analyzed (Next (Next (First (Expressions (N)))));
7018 Analyze_And_Resolve (N, Typ);
7021 end Expand_N_Op_Mod;
7023 --------------------------
7024 -- Expand_N_Op_Multiply --
7025 --------------------------
7027 procedure Expand_N_Op_Multiply (N : Node_Id) is
7028 Loc : constant Source_Ptr := Sloc (N);
7029 Lop : constant Node_Id := Left_Opnd (N);
7030 Rop : constant Node_Id := Right_Opnd (N);
7032 Lp2 : constant Boolean :=
7033 Nkind (Lop) = N_Op_Expon
7034 and then Is_Power_Of_2_For_Shift (Lop);
7036 Rp2 : constant Boolean :=
7037 Nkind (Rop) = N_Op_Expon
7038 and then Is_Power_Of_2_For_Shift (Rop);
7040 Ltyp : constant Entity_Id := Etype (Lop);
7041 Rtyp : constant Entity_Id := Etype (Rop);
7042 Typ : Entity_Id := Etype (N);
7045 Binary_Op_Validity_Checks (N);
7047 -- Special optimizations for integer types
7049 if Is_Integer_Type (Typ) then
7051 -- N * 0 = 0 for integer types
7053 if Compile_Time_Known_Value (Rop)
7054 and then Expr_Value (Rop) = Uint_0
7056 -- Call Remove_Side_Effects to ensure that any side effects in
7057 -- the ignored left operand (in particular function calls to
7058 -- user defined functions) are properly executed.
7060 Remove_Side_Effects (Lop);
7062 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7063 Analyze_And_Resolve (N, Typ);
7067 -- Similar handling for 0 * N = 0
7069 if Compile_Time_Known_Value (Lop)
7070 and then Expr_Value (Lop) = Uint_0
7072 Remove_Side_Effects (Rop);
7073 Rewrite (N, Make_Integer_Literal (Loc, Uint_0));
7074 Analyze_And_Resolve (N, Typ);
7078 -- N * 1 = 1 * N = N for integer types
7080 -- This optimisation is not done if we are going to
7081 -- rewrite the product 1 * 2 ** N to a shift.
7083 if Compile_Time_Known_Value (Rop)
7084 and then Expr_Value (Rop) = Uint_1
7090 elsif Compile_Time_Known_Value (Lop)
7091 and then Expr_Value (Lop) = Uint_1
7099 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
7100 -- Is_Power_Of_2_For_Shift is set means that we know that our left
7101 -- operand is an integer, as required for this to work.
7106 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
7110 Left_Opnd => Make_Integer_Literal (Loc, 2),
7113 Left_Opnd => Right_Opnd (Lop),
7114 Right_Opnd => Right_Opnd (Rop))));
7115 Analyze_And_Resolve (N, Typ);
7120 Make_Op_Shift_Left (Loc,
7123 Convert_To (Standard_Natural, Right_Opnd (Rop))));
7124 Analyze_And_Resolve (N, Typ);
7128 -- Same processing for the operands the other way round
7132 Make_Op_Shift_Left (Loc,
7135 Convert_To (Standard_Natural, Right_Opnd (Lop))));
7136 Analyze_And_Resolve (N, Typ);
7140 -- Do required fixup of universal fixed operation
7142 if Typ = Universal_Fixed then
7143 Fixup_Universal_Fixed_Operation (N);
7147 -- Multiplications with fixed-point results
7149 if Is_Fixed_Point_Type (Typ) then
7151 -- No special processing if Treat_Fixed_As_Integer is set, since from
7152 -- a semantic point of view such operations are simply integer
7153 -- operations and will be treated that way.
7155 if not Treat_Fixed_As_Integer (N) then
7157 -- Case of fixed * integer => fixed
7159 if Is_Integer_Type (Rtyp) then
7160 Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N);
7162 -- Case of integer * fixed => fixed
7164 elsif Is_Integer_Type (Ltyp) then
7165 Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N);
7167 -- Case of fixed * fixed => fixed
7170 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N);
7174 -- Other cases of multiplication of fixed-point operands. Again we
7175 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
7177 elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp))
7178 and then not Treat_Fixed_As_Integer (N)
7180 if Is_Integer_Type (Typ) then
7181 Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N);
7183 pragma Assert (Is_Floating_Point_Type (Typ));
7184 Expand_Multiply_Fixed_By_Fixed_Giving_Float (N);
7187 -- Mixed-mode operations can appear in a non-static universal context,
7188 -- in which case the integer argument must be converted explicitly.
7190 elsif Typ = Universal_Real
7191 and then Is_Integer_Type (Rtyp)
7193 Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop)));
7195 Analyze_And_Resolve (Rop, Universal_Real);
7197 elsif Typ = Universal_Real
7198 and then Is_Integer_Type (Ltyp)
7200 Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop)));
7202 Analyze_And_Resolve (Lop, Universal_Real);
7204 -- Non-fixed point cases, check software overflow checking required
7206 elsif Is_Signed_Integer_Type (Etype (N)) then
7207 Apply_Arithmetic_Overflow_Check (N);
7209 -- Deal with VAX float case
7211 elsif Vax_Float (Typ) then
7212 Expand_Vax_Arith (N);
7215 end Expand_N_Op_Multiply;
7217 --------------------
7218 -- Expand_N_Op_Ne --
7219 --------------------
7221 procedure Expand_N_Op_Ne (N : Node_Id) is
7222 Typ : constant Entity_Id := Etype (Left_Opnd (N));
7225 -- Case of elementary type with standard operator
7227 if Is_Elementary_Type (Typ)
7228 and then Sloc (Entity (N)) = Standard_Location
7230 Binary_Op_Validity_Checks (N);
7232 -- Boolean types (requiring handling of non-standard case)
7234 if Is_Boolean_Type (Typ) then
7235 Adjust_Condition (Left_Opnd (N));
7236 Adjust_Condition (Right_Opnd (N));
7237 Set_Etype (N, Standard_Boolean);
7238 Adjust_Result_Type (N, Typ);
7241 Rewrite_Comparison (N);
7243 -- If we still have comparison for Vax_Float, process it
7245 if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then
7246 Expand_Vax_Comparison (N);
7250 -- For all cases other than elementary types, we rewrite node as the
7251 -- negation of an equality operation, and reanalyze. The equality to be
7252 -- used is defined in the same scope and has the same signature. This
7253 -- signature must be set explicitly since in an instance it may not have
7254 -- the same visibility as in the generic unit. This avoids duplicating
7255 -- or factoring the complex code for record/array equality tests etc.
7259 Loc : constant Source_Ptr := Sloc (N);
7261 Ne : constant Entity_Id := Entity (N);
7264 Binary_Op_Validity_Checks (N);
7270 Left_Opnd => Left_Opnd (N),
7271 Right_Opnd => Right_Opnd (N)));
7272 Set_Paren_Count (Right_Opnd (Neg), 1);
7274 if Scope (Ne) /= Standard_Standard then
7275 Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne));
7278 -- For navigation purposes, we want to treat the inequality as an
7279 -- implicit reference to the corresponding equality. Preserve the
7280 -- Comes_From_ source flag to generate proper Xref entries.
7282 Preserve_Comes_From_Source (Neg, N);
7283 Preserve_Comes_From_Source (Right_Opnd (Neg), N);
7285 Analyze_And_Resolve (N, Standard_Boolean);
7289 Optimize_Length_Comparison (N);
7292 ---------------------
7293 -- Expand_N_Op_Not --
7294 ---------------------
7296 -- If the argument is other than a Boolean array type, there is no special
7297 -- expansion required, except for VMS operations on signed integers.
7299 -- For the packed case, we call the special routine in Exp_Pakd, except
7300 -- that if the component size is greater than one, we use the standard
7301 -- routine generating a gruesome loop (it is so peculiar to have packed
7302 -- arrays with non-standard Boolean representations anyway, so it does not
7303 -- matter that we do not handle this case efficiently).
7305 -- For the unpacked case (and for the special packed case where we have non
7306 -- standard Booleans, as discussed above), we generate and insert into the
7307 -- tree the following function definition:
7309 -- function Nnnn (A : arr) is
7312 -- for J in a'range loop
7313 -- B (J) := not A (J);
7318 -- Here arr is the actual subtype of the parameter (and hence always
7319 -- constrained). Then we replace the not with a call to this function.
7321 procedure Expand_N_Op_Not (N : Node_Id) is
7322 Loc : constant Source_Ptr := Sloc (N);
7323 Typ : constant Entity_Id := Etype (N);
7332 Func_Name : Entity_Id;
7333 Loop_Statement : Node_Id;
7336 Unary_Op_Validity_Checks (N);
7338 -- For boolean operand, deal with non-standard booleans
7340 if Is_Boolean_Type (Typ) then
7341 Adjust_Condition (Right_Opnd (N));
7342 Set_Etype (N, Standard_Boolean);
7343 Adjust_Result_Type (N, Typ);
7347 -- For the VMS "not" on signed integer types, use conversion to and from
7348 -- a predefined modular type.
7350 if Is_VMS_Operator (Entity (N)) then
7356 -- If this is a derived type, retrieve original VMS type so that
7357 -- the proper sized type is used for intermediate values.
7359 if Is_Derived_Type (Typ) then
7360 Rtyp := First_Subtype (Etype (Typ));
7365 -- The proper unsigned type must have a size compatible with the
7366 -- operand, to prevent misalignment.
7368 if RM_Size (Rtyp) <= 8 then
7369 Utyp := RTE (RE_Unsigned_8);
7371 elsif RM_Size (Rtyp) <= 16 then
7372 Utyp := RTE (RE_Unsigned_16);
7374 elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then
7375 Utyp := RTE (RE_Unsigned_32);
7378 Utyp := RTE (RE_Long_Long_Unsigned);
7382 Unchecked_Convert_To (Typ,
7384 Unchecked_Convert_To (Utyp, Right_Opnd (N)))));
7385 Analyze_And_Resolve (N, Typ);
7390 -- Only array types need any other processing
7392 if not Is_Array_Type (Typ) then
7396 -- Case of array operand. If bit packed with a component size of 1,
7397 -- handle it in Exp_Pakd if the operand is known to be aligned.
7399 if Is_Bit_Packed_Array (Typ)
7400 and then Component_Size (Typ) = 1
7401 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
7403 Expand_Packed_Not (N);
7407 -- Case of array operand which is not bit-packed. If the context is
7408 -- a safe assignment, call in-place operation, If context is a larger
7409 -- boolean expression in the context of a safe assignment, expansion is
7410 -- done by enclosing operation.
7412 Opnd := Relocate_Node (Right_Opnd (N));
7413 Convert_To_Actual_Subtype (Opnd);
7414 Arr := Etype (Opnd);
7415 Ensure_Defined (Arr, N);
7416 Silly_Boolean_Array_Not_Test (N, Arr);
7418 if Nkind (Parent (N)) = N_Assignment_Statement then
7419 if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then
7420 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7423 -- Special case the negation of a binary operation
7425 elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor)
7426 and then Safe_In_Place_Array_Op
7427 (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd))
7429 Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
7433 elsif Nkind (Parent (N)) in N_Binary_Op
7434 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
7437 Op1 : constant Node_Id := Left_Opnd (Parent (N));
7438 Op2 : constant Node_Id := Right_Opnd (Parent (N));
7439 Lhs : constant Node_Id := Name (Parent (Parent (N)));
7442 if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then
7444 -- (not A) op (not B) can be reduced to a single call
7446 if N = Op1 and then Nkind (Op2) = N_Op_Not then
7449 elsif N = Op2 and then Nkind (Op1) = N_Op_Not then
7452 -- A xor (not B) can also be special-cased
7454 elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then
7461 A := Make_Defining_Identifier (Loc, Name_uA);
7462 B := Make_Defining_Identifier (Loc, Name_uB);
7463 J := Make_Defining_Identifier (Loc, Name_uJ);
7466 Make_Indexed_Component (Loc,
7467 Prefix => New_Reference_To (A, Loc),
7468 Expressions => New_List (New_Reference_To (J, Loc)));
7471 Make_Indexed_Component (Loc,
7472 Prefix => New_Reference_To (B, Loc),
7473 Expressions => New_List (New_Reference_To (J, Loc)));
7476 Make_Implicit_Loop_Statement (N,
7477 Identifier => Empty,
7480 Make_Iteration_Scheme (Loc,
7481 Loop_Parameter_Specification =>
7482 Make_Loop_Parameter_Specification (Loc,
7483 Defining_Identifier => J,
7484 Discrete_Subtype_Definition =>
7485 Make_Attribute_Reference (Loc,
7486 Prefix => Make_Identifier (Loc, Chars (A)),
7487 Attribute_Name => Name_Range))),
7489 Statements => New_List (
7490 Make_Assignment_Statement (Loc,
7492 Expression => Make_Op_Not (Loc, A_J))));
7494 Func_Name := Make_Temporary (Loc, 'N');
7495 Set_Is_Inlined (Func_Name);
7498 Make_Subprogram_Body (Loc,
7500 Make_Function_Specification (Loc,
7501 Defining_Unit_Name => Func_Name,
7502 Parameter_Specifications => New_List (
7503 Make_Parameter_Specification (Loc,
7504 Defining_Identifier => A,
7505 Parameter_Type => New_Reference_To (Typ, Loc))),
7506 Result_Definition => New_Reference_To (Typ, Loc)),
7508 Declarations => New_List (
7509 Make_Object_Declaration (Loc,
7510 Defining_Identifier => B,
7511 Object_Definition => New_Reference_To (Arr, Loc))),
7513 Handled_Statement_Sequence =>
7514 Make_Handled_Sequence_Of_Statements (Loc,
7515 Statements => New_List (
7517 Make_Simple_Return_Statement (Loc,
7518 Expression => Make_Identifier (Loc, Chars (B)))))));
7521 Make_Function_Call (Loc,
7522 Name => New_Reference_To (Func_Name, Loc),
7523 Parameter_Associations => New_List (Opnd)));
7525 Analyze_And_Resolve (N, Typ);
7526 end Expand_N_Op_Not;
7528 --------------------
7529 -- Expand_N_Op_Or --
7530 --------------------
7532 procedure Expand_N_Op_Or (N : Node_Id) is
7533 Typ : constant Entity_Id := Etype (N);
7536 Binary_Op_Validity_Checks (N);
7538 if Is_Array_Type (Etype (N)) then
7539 Expand_Boolean_Operator (N);
7541 elsif Is_Boolean_Type (Etype (N)) then
7542 Adjust_Condition (Left_Opnd (N));
7543 Adjust_Condition (Right_Opnd (N));
7544 Set_Etype (N, Standard_Boolean);
7545 Adjust_Result_Type (N, Typ);
7547 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7548 Expand_Intrinsic_Call (N, Entity (N));
7553 ----------------------
7554 -- Expand_N_Op_Plus --
7555 ----------------------
7557 procedure Expand_N_Op_Plus (N : Node_Id) is
7559 Unary_Op_Validity_Checks (N);
7560 end Expand_N_Op_Plus;
7562 ---------------------
7563 -- Expand_N_Op_Rem --
7564 ---------------------
7566 procedure Expand_N_Op_Rem (N : Node_Id) is
7567 Loc : constant Source_Ptr := Sloc (N);
7568 Typ : constant Entity_Id := Etype (N);
7570 Left : constant Node_Id := Left_Opnd (N);
7571 Right : constant Node_Id := Right_Opnd (N);
7579 -- Set if corresponding operand can be negative
7581 pragma Unreferenced (Hi);
7584 Binary_Op_Validity_Checks (N);
7586 if Is_Integer_Type (Etype (N)) then
7587 Apply_Divide_Check (N);
7590 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
7591 -- but it is useful with other back ends (e.g. AAMP), and is certainly
7594 if Is_Integer_Type (Etype (N))
7595 and then Compile_Time_Known_Value (Right)
7596 and then Expr_Value (Right) = Uint_1
7598 -- Call Remove_Side_Effects to ensure that any side effects in the
7599 -- ignored left operand (in particular function calls to user defined
7600 -- functions) are properly executed.
7602 Remove_Side_Effects (Left);
7604 Rewrite (N, Make_Integer_Literal (Loc, 0));
7605 Analyze_And_Resolve (N, Typ);
7609 -- Deal with annoying case of largest negative number remainder minus
7610 -- one. Gigi does not handle this case correctly, because it generates
7611 -- a divide instruction which may trap in this case.
7613 -- In fact the check is quite easy, if the right operand is -1, then
7614 -- the remainder is always 0, and we can just ignore the left operand
7615 -- completely in this case.
7617 Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True);
7618 Lneg := (not OK) or else Lo < 0;
7620 Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True);
7621 Rneg := (not OK) or else Lo < 0;
7623 -- We won't mess with trying to find out if the left operand can really
7624 -- be the largest negative number (that's a pain in the case of private
7625 -- types and this is really marginal). We will just assume that we need
7626 -- the test if the left operand can be negative at all.
7628 if Lneg and Rneg then
7630 Make_Conditional_Expression (Loc,
7631 Expressions => New_List (
7633 Left_Opnd => Duplicate_Subexpr (Right),
7635 Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))),
7637 Unchecked_Convert_To (Typ,
7638 Make_Integer_Literal (Loc, Uint_0)),
7640 Relocate_Node (N))));
7642 Set_Analyzed (Next (Next (First (Expressions (N)))));
7643 Analyze_And_Resolve (N, Typ);
7645 end Expand_N_Op_Rem;
7647 -----------------------------
7648 -- Expand_N_Op_Rotate_Left --
7649 -----------------------------
7651 procedure Expand_N_Op_Rotate_Left (N : Node_Id) is
7653 Binary_Op_Validity_Checks (N);
7654 end Expand_N_Op_Rotate_Left;
7656 ------------------------------
7657 -- Expand_N_Op_Rotate_Right --
7658 ------------------------------
7660 procedure Expand_N_Op_Rotate_Right (N : Node_Id) is
7662 Binary_Op_Validity_Checks (N);
7663 end Expand_N_Op_Rotate_Right;
7665 ----------------------------
7666 -- Expand_N_Op_Shift_Left --
7667 ----------------------------
7669 procedure Expand_N_Op_Shift_Left (N : Node_Id) is
7671 Binary_Op_Validity_Checks (N);
7672 end Expand_N_Op_Shift_Left;
7674 -----------------------------
7675 -- Expand_N_Op_Shift_Right --
7676 -----------------------------
7678 procedure Expand_N_Op_Shift_Right (N : Node_Id) is
7680 Binary_Op_Validity_Checks (N);
7681 end Expand_N_Op_Shift_Right;
7683 ----------------------------------------
7684 -- Expand_N_Op_Shift_Right_Arithmetic --
7685 ----------------------------------------
7687 procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is
7689 Binary_Op_Validity_Checks (N);
7690 end Expand_N_Op_Shift_Right_Arithmetic;
7692 --------------------------
7693 -- Expand_N_Op_Subtract --
7694 --------------------------
7696 procedure Expand_N_Op_Subtract (N : Node_Id) is
7697 Typ : constant Entity_Id := Etype (N);
7700 Binary_Op_Validity_Checks (N);
7702 -- N - 0 = N for integer types
7704 if Is_Integer_Type (Typ)
7705 and then Compile_Time_Known_Value (Right_Opnd (N))
7706 and then Expr_Value (Right_Opnd (N)) = 0
7708 Rewrite (N, Left_Opnd (N));
7712 -- Arithmetic overflow checks for signed integer/fixed point types
7714 if Is_Signed_Integer_Type (Typ)
7716 Is_Fixed_Point_Type (Typ)
7718 Apply_Arithmetic_Overflow_Check (N);
7720 -- VAX floating-point types case
7722 elsif Vax_Float (Typ) then
7723 Expand_Vax_Arith (N);
7725 end Expand_N_Op_Subtract;
7727 ---------------------
7728 -- Expand_N_Op_Xor --
7729 ---------------------
7731 procedure Expand_N_Op_Xor (N : Node_Id) is
7732 Typ : constant Entity_Id := Etype (N);
7735 Binary_Op_Validity_Checks (N);
7737 if Is_Array_Type (Etype (N)) then
7738 Expand_Boolean_Operator (N);
7740 elsif Is_Boolean_Type (Etype (N)) then
7741 Adjust_Condition (Left_Opnd (N));
7742 Adjust_Condition (Right_Opnd (N));
7743 Set_Etype (N, Standard_Boolean);
7744 Adjust_Result_Type (N, Typ);
7746 elsif Is_Intrinsic_Subprogram (Entity (N)) then
7747 Expand_Intrinsic_Call (N, Entity (N));
7750 end Expand_N_Op_Xor;
7752 ----------------------
7753 -- Expand_N_Or_Else --
7754 ----------------------
7756 procedure Expand_N_Or_Else (N : Node_Id)
7757 renames Expand_Short_Circuit_Operator;
7759 -----------------------------------
7760 -- Expand_N_Qualified_Expression --
7761 -----------------------------------
7763 procedure Expand_N_Qualified_Expression (N : Node_Id) is
7764 Operand : constant Node_Id := Expression (N);
7765 Target_Type : constant Entity_Id := Entity (Subtype_Mark (N));
7768 -- Do validity check if validity checking operands
7770 if Validity_Checks_On
7771 and then Validity_Check_Operands
7773 Ensure_Valid (Operand);
7776 -- Apply possible constraint check
7778 Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True);
7780 if Do_Range_Check (Operand) then
7781 Set_Do_Range_Check (Operand, False);
7782 Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed);
7784 end Expand_N_Qualified_Expression;
7786 ------------------------------------
7787 -- Expand_N_Quantified_Expression --
7788 ------------------------------------
7792 -- for all X in range => Cond
7797 -- for X in range loop
7804 -- Conversely, an existentially quantified expression:
7806 -- for some X in range => Cond
7811 -- for X in range loop
7818 -- In both cases, the iteration may be over a container in which case it is
7819 -- given by an iterator specification, not a loop parameter specification.
7821 procedure Expand_N_Quantified_Expression (N : Node_Id) is
7822 Loc : constant Source_Ptr := Sloc (N);
7823 Is_Universal : constant Boolean := All_Present (N);
7824 Actions : constant List_Id := New_List;
7825 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N);
7833 Make_Object_Declaration (Loc,
7834 Defining_Identifier => Tnn,
7835 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc),
7837 New_Occurrence_Of (Boolean_Literals (Is_Universal), Loc));
7838 Append_To (Actions, Decl);
7840 Cond := Relocate_Node (Condition (N));
7842 -- Reset flag analyzed in the condition to force its analysis. Required
7843 -- since the previous analysis was done with expansion disabled (see
7844 -- Resolve_Quantified_Expression) and hence checks were not inserted
7845 -- and record comparisons have not been expanded.
7847 Reset_Analyzed_Flags (Cond);
7849 if Is_Universal then
7850 Cond := Make_Op_Not (Loc, Cond);
7854 Make_Implicit_If_Statement (N,
7856 Then_Statements => New_List (
7857 Make_Assignment_Statement (Loc,
7858 Name => New_Occurrence_Of (Tnn, Loc),
7860 New_Occurrence_Of (Boolean_Literals (not Is_Universal), Loc)),
7861 Make_Exit_Statement (Loc)));
7863 if Present (Loop_Parameter_Specification (N)) then
7865 Make_Iteration_Scheme (Loc,
7866 Loop_Parameter_Specification =>
7867 Loop_Parameter_Specification (N));
7870 Make_Iteration_Scheme (Loc,
7871 Iterator_Specification => Iterator_Specification (N));
7875 Make_Loop_Statement (Loc,
7876 Iteration_Scheme => I_Scheme,
7877 Statements => New_List (Test),
7878 End_Label => Empty));
7881 Make_Expression_With_Actions (Loc,
7882 Expression => New_Occurrence_Of (Tnn, Loc),
7883 Actions => Actions));
7885 Analyze_And_Resolve (N, Standard_Boolean);
7886 end Expand_N_Quantified_Expression;
7888 ---------------------------------
7889 -- Expand_N_Selected_Component --
7890 ---------------------------------
7892 procedure Expand_N_Selected_Component (N : Node_Id) is
7893 Loc : constant Source_Ptr := Sloc (N);
7894 Par : constant Node_Id := Parent (N);
7895 P : constant Node_Id := Prefix (N);
7896 Ptyp : Entity_Id := Underlying_Type (Etype (P));
7902 function In_Left_Hand_Side (Comp : Node_Id) return Boolean;
7903 -- Gigi needs a temporary for prefixes that depend on a discriminant,
7904 -- unless the context of an assignment can provide size information.
7905 -- Don't we have a general routine that does this???
7907 function Is_Subtype_Declaration return Boolean;
7908 -- The replacement of a discriminant reference by its value is required
7909 -- if this is part of the initialization of an temporary generated by a
7910 -- change of representation. This shows up as the construction of a
7911 -- discriminant constraint for a subtype declared at the same point as
7912 -- the entity in the prefix of the selected component. We recognize this
7913 -- case when the context of the reference is:
7914 -- subtype ST is T(Obj.D);
7915 -- where the entity for Obj comes from source, and ST has the same sloc.
7917 -----------------------
7918 -- In_Left_Hand_Side --
7919 -----------------------
7921 function In_Left_Hand_Side (Comp : Node_Id) return Boolean is
7923 return (Nkind (Parent (Comp)) = N_Assignment_Statement
7924 and then Comp = Name (Parent (Comp)))
7925 or else (Present (Parent (Comp))
7926 and then Nkind (Parent (Comp)) in N_Subexpr
7927 and then In_Left_Hand_Side (Parent (Comp)));
7928 end In_Left_Hand_Side;
7930 -----------------------------
7931 -- Is_Subtype_Declaration --
7932 -----------------------------
7934 function Is_Subtype_Declaration return Boolean is
7935 Par : constant Node_Id := Parent (N);
7938 Nkind (Par) = N_Index_Or_Discriminant_Constraint
7939 and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration
7940 and then Comes_From_Source (Entity (Prefix (N)))
7941 and then Sloc (Par) = Sloc (Entity (Prefix (N)));
7942 end Is_Subtype_Declaration;
7944 -- Start of processing for Expand_N_Selected_Component
7947 -- Insert explicit dereference if required
7949 if Is_Access_Type (Ptyp) then
7951 -- First set prefix type to proper access type, in case it currently
7952 -- has a private (non-access) view of this type.
7954 Set_Etype (P, Ptyp);
7956 Insert_Explicit_Dereference (P);
7957 Analyze_And_Resolve (P, Designated_Type (Ptyp));
7959 if Ekind (Etype (P)) = E_Private_Subtype
7960 and then Is_For_Access_Subtype (Etype (P))
7962 Set_Etype (P, Base_Type (Etype (P)));
7968 -- Deal with discriminant check required
7970 if Do_Discriminant_Check (N) then
7972 -- Present the discriminant checking function to the backend, so that
7973 -- it can inline the call to the function.
7976 (Discriminant_Checking_Func
7977 (Original_Record_Component (Entity (Selector_Name (N)))));
7979 -- Now reset the flag and generate the call
7981 Set_Do_Discriminant_Check (N, False);
7982 Generate_Discriminant_Check (N);
7985 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
7986 -- function, then additional actuals must be passed.
7988 if Ada_Version >= Ada_2005
7989 and then Is_Build_In_Place_Function_Call (P)
7991 Make_Build_In_Place_Call_In_Anonymous_Context (P);
7994 -- Gigi cannot handle unchecked conversions that are the prefix of a
7995 -- selected component with discriminants. This must be checked during
7996 -- expansion, because during analysis the type of the selector is not
7997 -- known at the point the prefix is analyzed. If the conversion is the
7998 -- target of an assignment, then we cannot force the evaluation.
8000 if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion
8001 and then Has_Discriminants (Etype (N))
8002 and then not In_Left_Hand_Side (N)
8004 Force_Evaluation (Prefix (N));
8007 -- Remaining processing applies only if selector is a discriminant
8009 if Ekind (Entity (Selector_Name (N))) = E_Discriminant then
8011 -- If the selector is a discriminant of a constrained record type,
8012 -- we may be able to rewrite the expression with the actual value
8013 -- of the discriminant, a useful optimization in some cases.
8015 if Is_Record_Type (Ptyp)
8016 and then Has_Discriminants (Ptyp)
8017 and then Is_Constrained (Ptyp)
8019 -- Do this optimization for discrete types only, and not for
8020 -- access types (access discriminants get us into trouble!)
8022 if not Is_Discrete_Type (Etype (N)) then
8025 -- Don't do this on the left hand of an assignment statement.
8026 -- Normally one would think that references like this would not
8027 -- occur, but they do in generated code, and mean that we really
8028 -- do want to assign the discriminant!
8030 elsif Nkind (Par) = N_Assignment_Statement
8031 and then Name (Par) = N
8035 -- Don't do this optimization for the prefix of an attribute or
8036 -- the name of an object renaming declaration since these are
8037 -- contexts where we do not want the value anyway.
8039 elsif (Nkind (Par) = N_Attribute_Reference
8040 and then Prefix (Par) = N)
8041 or else Is_Renamed_Object (N)
8045 -- Don't do this optimization if we are within the code for a
8046 -- discriminant check, since the whole point of such a check may
8047 -- be to verify the condition on which the code below depends!
8049 elsif Is_In_Discriminant_Check (N) then
8052 -- Green light to see if we can do the optimization. There is
8053 -- still one condition that inhibits the optimization below but
8054 -- now is the time to check the particular discriminant.
8057 -- Loop through discriminants to find the matching discriminant
8058 -- constraint to see if we can copy it.
8060 Disc := First_Discriminant (Ptyp);
8061 Dcon := First_Elmt (Discriminant_Constraint (Ptyp));
8062 Discr_Loop : while Present (Dcon) loop
8063 Dval := Node (Dcon);
8065 -- Check if this is the matching discriminant and if the
8066 -- discriminant value is simple enough to make sense to
8067 -- copy. We don't want to copy complex expressions, and
8068 -- indeed to do so can cause trouble (before we put in
8069 -- this guard, a discriminant expression containing an
8070 -- AND THEN was copied, causing problems for coverage
8073 -- However, if the reference is part of the initialization
8074 -- code generated for an object declaration, we must use
8075 -- the discriminant value from the subtype constraint,
8076 -- because the selected component may be a reference to the
8077 -- object being initialized, whose discriminant is not yet
8078 -- set. This only happens in complex cases involving changes
8079 -- or representation.
8081 if Disc = Entity (Selector_Name (N))
8082 and then (Is_Entity_Name (Dval)
8083 or else Compile_Time_Known_Value (Dval)
8084 or else Is_Subtype_Declaration)
8086 -- Here we have the matching discriminant. Check for
8087 -- the case of a discriminant of a component that is
8088 -- constrained by an outer discriminant, which cannot
8089 -- be optimized away.
8091 if Denotes_Discriminant
8092 (Dval, Check_Concurrent => True)
8096 elsif Nkind (Original_Node (Dval)) = N_Selected_Component
8098 Denotes_Discriminant
8099 (Selector_Name (Original_Node (Dval)), True)
8103 -- Do not retrieve value if constraint is not static. It
8104 -- is generally not useful, and the constraint may be a
8105 -- rewritten outer discriminant in which case it is in
8108 elsif Is_Entity_Name (Dval)
8109 and then Nkind (Parent (Entity (Dval))) =
8110 N_Object_Declaration
8111 and then Present (Expression (Parent (Entity (Dval))))
8113 not Is_Static_Expression
8114 (Expression (Parent (Entity (Dval))))
8118 -- In the context of a case statement, the expression may
8119 -- have the base type of the discriminant, and we need to
8120 -- preserve the constraint to avoid spurious errors on
8123 elsif Nkind (Parent (N)) = N_Case_Statement
8124 and then Etype (Dval) /= Etype (Disc)
8127 Make_Qualified_Expression (Loc,
8129 New_Occurrence_Of (Etype (Disc), Loc),
8131 New_Copy_Tree (Dval)));
8132 Analyze_And_Resolve (N, Etype (Disc));
8134 -- In case that comes out as a static expression,
8135 -- reset it (a selected component is never static).
8137 Set_Is_Static_Expression (N, False);
8140 -- Otherwise we can just copy the constraint, but the
8141 -- result is certainly not static! In some cases the
8142 -- discriminant constraint has been analyzed in the
8143 -- context of the original subtype indication, but for
8144 -- itypes the constraint might not have been analyzed
8145 -- yet, and this must be done now.
8148 Rewrite (N, New_Copy_Tree (Dval));
8149 Analyze_And_Resolve (N);
8150 Set_Is_Static_Expression (N, False);
8156 Next_Discriminant (Disc);
8157 end loop Discr_Loop;
8159 -- Note: the above loop should always find a matching
8160 -- discriminant, but if it does not, we just missed an
8161 -- optimization due to some glitch (perhaps a previous
8162 -- error), so ignore.
8167 -- The only remaining processing is in the case of a discriminant of
8168 -- a concurrent object, where we rewrite the prefix to denote the
8169 -- corresponding record type. If the type is derived and has renamed
8170 -- discriminants, use corresponding discriminant, which is the one
8171 -- that appears in the corresponding record.
8173 if not Is_Concurrent_Type (Ptyp) then
8177 Disc := Entity (Selector_Name (N));
8179 if Is_Derived_Type (Ptyp)
8180 and then Present (Corresponding_Discriminant (Disc))
8182 Disc := Corresponding_Discriminant (Disc);
8186 Make_Selected_Component (Loc,
8188 Unchecked_Convert_To (Corresponding_Record_Type (Ptyp),
8190 Selector_Name => Make_Identifier (Loc, Chars (Disc)));
8196 -- Set Atomic_Sync_Required if necessary for atomic component
8198 if Nkind (N) = N_Selected_Component then
8200 E : constant Entity_Id := Entity (Selector_Name (N));
8204 -- If component is atomic, but type is not, setting depends on
8205 -- disable/enable state for the component.
8207 if Is_Atomic (E) and then not Is_Atomic (Etype (E)) then
8208 Set := not Atomic_Synchronization_Disabled (E);
8210 -- If component is not atomic, but its type is atomic, setting
8211 -- depends on disable/enable state for the type.
8213 elsif not Is_Atomic (E) and then Is_Atomic (Etype (E)) then
8214 Set := not Atomic_Synchronization_Disabled (Etype (E));
8216 -- If both component and type are atomic, we disable if either
8217 -- component or its type have sync disabled.
8219 elsif Is_Atomic (E) and then Is_Atomic (Etype (E)) then
8220 Set := (not Atomic_Synchronization_Disabled (E))
8222 (not Atomic_Synchronization_Disabled (Etype (E)));
8228 -- Set flag if required
8231 Activate_Atomic_Synchronization (N);
8235 end Expand_N_Selected_Component;
8237 --------------------
8238 -- Expand_N_Slice --
8239 --------------------
8241 procedure Expand_N_Slice (N : Node_Id) is
8242 Loc : constant Source_Ptr := Sloc (N);
8243 Typ : constant Entity_Id := Etype (N);
8244 Pfx : constant Node_Id := Prefix (N);
8245 Ptp : Entity_Id := Etype (Pfx);
8247 function Is_Procedure_Actual (N : Node_Id) return Boolean;
8248 -- Check whether the argument is an actual for a procedure call, in
8249 -- which case the expansion of a bit-packed slice is deferred until the
8250 -- call itself is expanded. The reason this is required is that we might
8251 -- have an IN OUT or OUT parameter, and the copy out is essential, and
8252 -- that copy out would be missed if we created a temporary here in
8253 -- Expand_N_Slice. Note that we don't bother to test specifically for an
8254 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
8255 -- is harmless to defer expansion in the IN case, since the call
8256 -- processing will still generate the appropriate copy in operation,
8257 -- which will take care of the slice.
8259 procedure Make_Temporary_For_Slice;
8260 -- Create a named variable for the value of the slice, in cases where
8261 -- the back-end cannot handle it properly, e.g. when packed types or
8262 -- unaligned slices are involved.
8264 -------------------------
8265 -- Is_Procedure_Actual --
8266 -------------------------
8268 function Is_Procedure_Actual (N : Node_Id) return Boolean is
8269 Par : Node_Id := Parent (N);
8273 -- If our parent is a procedure call we can return
8275 if Nkind (Par) = N_Procedure_Call_Statement then
8278 -- If our parent is a type conversion, keep climbing the tree,
8279 -- since a type conversion can be a procedure actual. Also keep
8280 -- climbing if parameter association or a qualified expression,
8281 -- since these are additional cases that do can appear on
8282 -- procedure actuals.
8284 elsif Nkind_In (Par, N_Type_Conversion,
8285 N_Parameter_Association,
8286 N_Qualified_Expression)
8288 Par := Parent (Par);
8290 -- Any other case is not what we are looking for
8296 end Is_Procedure_Actual;
8298 ------------------------------
8299 -- Make_Temporary_For_Slice --
8300 ------------------------------
8302 procedure Make_Temporary_For_Slice is
8304 Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N);
8308 Make_Object_Declaration (Loc,
8309 Defining_Identifier => Ent,
8310 Object_Definition => New_Occurrence_Of (Typ, Loc));
8312 Set_No_Initialization (Decl);
8314 Insert_Actions (N, New_List (
8316 Make_Assignment_Statement (Loc,
8317 Name => New_Occurrence_Of (Ent, Loc),
8318 Expression => Relocate_Node (N))));
8320 Rewrite (N, New_Occurrence_Of (Ent, Loc));
8321 Analyze_And_Resolve (N, Typ);
8322 end Make_Temporary_For_Slice;
8324 -- Start of processing for Expand_N_Slice
8327 -- Special handling for access types
8329 if Is_Access_Type (Ptp) then
8331 Ptp := Designated_Type (Ptp);
8334 Make_Explicit_Dereference (Sloc (N),
8335 Prefix => Relocate_Node (Pfx)));
8337 Analyze_And_Resolve (Pfx, Ptp);
8340 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
8341 -- function, then additional actuals must be passed.
8343 if Ada_Version >= Ada_2005
8344 and then Is_Build_In_Place_Function_Call (Pfx)
8346 Make_Build_In_Place_Call_In_Anonymous_Context (Pfx);
8349 -- The remaining case to be handled is packed slices. We can leave
8350 -- packed slices as they are in the following situations:
8352 -- 1. Right or left side of an assignment (we can handle this
8353 -- situation correctly in the assignment statement expansion).
8355 -- 2. Prefix of indexed component (the slide is optimized away in this
8356 -- case, see the start of Expand_N_Slice.)
8358 -- 3. Object renaming declaration, since we want the name of the
8359 -- slice, not the value.
8361 -- 4. Argument to procedure call, since copy-in/copy-out handling may
8362 -- be required, and this is handled in the expansion of call
8365 -- 5. Prefix of an address attribute (this is an error which is caught
8366 -- elsewhere, and the expansion would interfere with generating the
8369 if not Is_Packed (Typ) then
8371 -- Apply transformation for actuals of a function call, where
8372 -- Expand_Actuals is not used.
8374 if Nkind (Parent (N)) = N_Function_Call
8375 and then Is_Possibly_Unaligned_Slice (N)
8377 Make_Temporary_For_Slice;
8380 elsif Nkind (Parent (N)) = N_Assignment_Statement
8381 or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement
8382 and then Parent (N) = Name (Parent (Parent (N))))
8386 elsif Nkind (Parent (N)) = N_Indexed_Component
8387 or else Is_Renamed_Object (N)
8388 or else Is_Procedure_Actual (N)
8392 elsif Nkind (Parent (N)) = N_Attribute_Reference
8393 and then Attribute_Name (Parent (N)) = Name_Address
8398 Make_Temporary_For_Slice;
8402 ------------------------------
8403 -- Expand_N_Type_Conversion --
8404 ------------------------------
8406 procedure Expand_N_Type_Conversion (N : Node_Id) is
8407 Loc : constant Source_Ptr := Sloc (N);
8408 Operand : constant Node_Id := Expression (N);
8409 Target_Type : constant Entity_Id := Etype (N);
8410 Operand_Type : Entity_Id := Etype (Operand);
8412 procedure Handle_Changed_Representation;
8413 -- This is called in the case of record and array type conversions to
8414 -- see if there is a change of representation to be handled. Change of
8415 -- representation is actually handled at the assignment statement level,
8416 -- and what this procedure does is rewrite node N conversion as an
8417 -- assignment to temporary. If there is no change of representation,
8418 -- then the conversion node is unchanged.
8420 procedure Raise_Accessibility_Error;
8421 -- Called when we know that an accessibility check will fail. Rewrites
8422 -- node N to an appropriate raise statement and outputs warning msgs.
8423 -- The Etype of the raise node is set to Target_Type.
8425 procedure Real_Range_Check;
8426 -- Handles generation of range check for real target value
8428 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean;
8429 -- True iff Present (Effective_Extra_Accessibility (Id)) successfully
8430 -- evaluates to True.
8432 -----------------------------------
8433 -- Handle_Changed_Representation --
8434 -----------------------------------
8436 procedure Handle_Changed_Representation is
8445 -- Nothing else to do if no change of representation
8447 if Same_Representation (Operand_Type, Target_Type) then
8450 -- The real change of representation work is done by the assignment
8451 -- statement processing. So if this type conversion is appearing as
8452 -- the expression of an assignment statement, nothing needs to be
8453 -- done to the conversion.
8455 elsif Nkind (Parent (N)) = N_Assignment_Statement then
8458 -- Otherwise we need to generate a temporary variable, and do the
8459 -- change of representation assignment into that temporary variable.
8460 -- The conversion is then replaced by a reference to this variable.
8465 -- If type is unconstrained we have to add a constraint, copied
8466 -- from the actual value of the left hand side.
8468 if not Is_Constrained (Target_Type) then
8469 if Has_Discriminants (Operand_Type) then
8470 Disc := First_Discriminant (Operand_Type);
8472 if Disc /= First_Stored_Discriminant (Operand_Type) then
8473 Disc := First_Stored_Discriminant (Operand_Type);
8477 while Present (Disc) loop
8479 Make_Selected_Component (Loc,
8481 Duplicate_Subexpr_Move_Checks (Operand),
8483 Make_Identifier (Loc, Chars (Disc))));
8484 Next_Discriminant (Disc);
8487 elsif Is_Array_Type (Operand_Type) then
8488 N_Ix := First_Index (Target_Type);
8491 for J in 1 .. Number_Dimensions (Operand_Type) loop
8493 -- We convert the bounds explicitly. We use an unchecked
8494 -- conversion because bounds checks are done elsewhere.
8499 Unchecked_Convert_To (Etype (N_Ix),
8500 Make_Attribute_Reference (Loc,
8502 Duplicate_Subexpr_No_Checks
8503 (Operand, Name_Req => True),
8504 Attribute_Name => Name_First,
8505 Expressions => New_List (
8506 Make_Integer_Literal (Loc, J)))),
8509 Unchecked_Convert_To (Etype (N_Ix),
8510 Make_Attribute_Reference (Loc,
8512 Duplicate_Subexpr_No_Checks
8513 (Operand, Name_Req => True),
8514 Attribute_Name => Name_Last,
8515 Expressions => New_List (
8516 Make_Integer_Literal (Loc, J))))));
8523 Odef := New_Occurrence_Of (Target_Type, Loc);
8525 if Present (Cons) then
8527 Make_Subtype_Indication (Loc,
8528 Subtype_Mark => Odef,
8530 Make_Index_Or_Discriminant_Constraint (Loc,
8531 Constraints => Cons));
8534 Temp := Make_Temporary (Loc, 'C');
8536 Make_Object_Declaration (Loc,
8537 Defining_Identifier => Temp,
8538 Object_Definition => Odef);
8540 Set_No_Initialization (Decl, True);
8542 -- Insert required actions. It is essential to suppress checks
8543 -- since we have suppressed default initialization, which means
8544 -- that the variable we create may have no discriminants.
8549 Make_Assignment_Statement (Loc,
8550 Name => New_Occurrence_Of (Temp, Loc),
8551 Expression => Relocate_Node (N))),
8552 Suppress => All_Checks);
8554 Rewrite (N, New_Occurrence_Of (Temp, Loc));
8557 end Handle_Changed_Representation;
8559 -------------------------------
8560 -- Raise_Accessibility_Error --
8561 -------------------------------
8563 procedure Raise_Accessibility_Error is
8566 Make_Raise_Program_Error (Sloc (N),
8567 Reason => PE_Accessibility_Check_Failed));
8568 Set_Etype (N, Target_Type);
8570 Error_Msg_N ("?accessibility check failure", N);
8572 ("\?& will be raised at run time", N, Standard_Program_Error);
8573 end Raise_Accessibility_Error;
8575 ----------------------
8576 -- Real_Range_Check --
8577 ----------------------
8579 -- Case of conversions to floating-point or fixed-point. If range checks
8580 -- are enabled and the target type has a range constraint, we convert:
8586 -- Tnn : typ'Base := typ'Base (x);
8587 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
8590 -- This is necessary when there is a conversion of integer to float or
8591 -- to fixed-point to ensure that the correct checks are made. It is not
8592 -- necessary for float to float where it is enough to simply set the
8593 -- Do_Range_Check flag.
8595 procedure Real_Range_Check is
8596 Btyp : constant Entity_Id := Base_Type (Target_Type);
8597 Lo : constant Node_Id := Type_Low_Bound (Target_Type);
8598 Hi : constant Node_Id := Type_High_Bound (Target_Type);
8599 Xtyp : constant Entity_Id := Etype (Operand);
8604 -- Nothing to do if conversion was rewritten
8606 if Nkind (N) /= N_Type_Conversion then
8610 -- Nothing to do if range checks suppressed, or target has the same
8611 -- range as the base type (or is the base type).
8613 if Range_Checks_Suppressed (Target_Type)
8614 or else (Lo = Type_Low_Bound (Btyp)
8616 Hi = Type_High_Bound (Btyp))
8621 -- Nothing to do if expression is an entity on which checks have been
8624 if Is_Entity_Name (Operand)
8625 and then Range_Checks_Suppressed (Entity (Operand))
8630 -- Nothing to do if bounds are all static and we can tell that the
8631 -- expression is within the bounds of the target. Note that if the
8632 -- operand is of an unconstrained floating-point type, then we do
8633 -- not trust it to be in range (might be infinite)
8636 S_Lo : constant Node_Id := Type_Low_Bound (Xtyp);
8637 S_Hi : constant Node_Id := Type_High_Bound (Xtyp);
8640 if (not Is_Floating_Point_Type (Xtyp)
8641 or else Is_Constrained (Xtyp))
8642 and then Compile_Time_Known_Value (S_Lo)
8643 and then Compile_Time_Known_Value (S_Hi)
8644 and then Compile_Time_Known_Value (Hi)
8645 and then Compile_Time_Known_Value (Lo)
8648 D_Lov : constant Ureal := Expr_Value_R (Lo);
8649 D_Hiv : constant Ureal := Expr_Value_R (Hi);
8654 if Is_Real_Type (Xtyp) then
8655 S_Lov := Expr_Value_R (S_Lo);
8656 S_Hiv := Expr_Value_R (S_Hi);
8658 S_Lov := UR_From_Uint (Expr_Value (S_Lo));
8659 S_Hiv := UR_From_Uint (Expr_Value (S_Hi));
8663 and then S_Lov >= D_Lov
8664 and then S_Hiv <= D_Hiv
8666 Set_Do_Range_Check (Operand, False);
8673 -- For float to float conversions, we are done
8675 if Is_Floating_Point_Type (Xtyp)
8677 Is_Floating_Point_Type (Btyp)
8682 -- Otherwise rewrite the conversion as described above
8684 Conv := Relocate_Node (N);
8685 Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc));
8686 Set_Etype (Conv, Btyp);
8688 -- Enable overflow except for case of integer to float conversions,
8689 -- where it is never required, since we can never have overflow in
8692 if not Is_Integer_Type (Etype (Operand)) then
8693 Enable_Overflow_Check (Conv);
8696 Tnn := Make_Temporary (Loc, 'T', Conv);
8698 Insert_Actions (N, New_List (
8699 Make_Object_Declaration (Loc,
8700 Defining_Identifier => Tnn,
8701 Object_Definition => New_Occurrence_Of (Btyp, Loc),
8702 Constant_Present => True,
8703 Expression => Conv),
8705 Make_Raise_Constraint_Error (Loc,
8710 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8712 Make_Attribute_Reference (Loc,
8713 Attribute_Name => Name_First,
8715 New_Occurrence_Of (Target_Type, Loc))),
8719 Left_Opnd => New_Occurrence_Of (Tnn, Loc),
8721 Make_Attribute_Reference (Loc,
8722 Attribute_Name => Name_Last,
8724 New_Occurrence_Of (Target_Type, Loc)))),
8725 Reason => CE_Range_Check_Failed)));
8727 Rewrite (N, New_Occurrence_Of (Tnn, Loc));
8728 Analyze_And_Resolve (N, Btyp);
8729 end Real_Range_Check;
8731 -----------------------------
8732 -- Has_Extra_Accessibility --
8733 -----------------------------
8735 -- Returns true for a formal of an anonymous access type or for
8736 -- an Ada 2012-style stand-alone object of an anonymous access type.
8738 function Has_Extra_Accessibility (Id : Entity_Id) return Boolean is
8740 if Is_Formal (Id) or else Ekind_In (Id, E_Constant, E_Variable) then
8741 return Present (Effective_Extra_Accessibility (Id));
8745 end Has_Extra_Accessibility;
8747 -- Start of processing for Expand_N_Type_Conversion
8750 -- Nothing at all to do if conversion is to the identical type so remove
8751 -- the conversion completely, it is useless, except that it may carry
8752 -- an Assignment_OK attribute, which must be propagated to the operand.
8754 if Operand_Type = Target_Type then
8755 if Assignment_OK (N) then
8756 Set_Assignment_OK (Operand);
8759 Rewrite (N, Relocate_Node (Operand));
8763 -- Nothing to do if this is the second argument of read. This is a
8764 -- "backwards" conversion that will be handled by the specialized code
8765 -- in attribute processing.
8767 if Nkind (Parent (N)) = N_Attribute_Reference
8768 and then Attribute_Name (Parent (N)) = Name_Read
8769 and then Next (First (Expressions (Parent (N)))) = N
8774 -- Check for case of converting to a type that has an invariant
8775 -- associated with it. This required an invariant check. We convert
8781 -- do invariant_check (typ (expr)) in typ (expr);
8783 -- using Duplicate_Subexpr to avoid multiple side effects
8785 -- Note: the Comes_From_Source check, and then the resetting of this
8786 -- flag prevents what would otherwise be an infinite recursion.
8788 if Has_Invariants (Target_Type)
8789 and then Present (Invariant_Procedure (Target_Type))
8790 and then Comes_From_Source (N)
8792 Set_Comes_From_Source (N, False);
8794 Make_Expression_With_Actions (Loc,
8795 Actions => New_List (
8796 Make_Invariant_Call (Duplicate_Subexpr (N))),
8797 Expression => Duplicate_Subexpr_No_Checks (N)));
8798 Analyze_And_Resolve (N, Target_Type);
8802 -- Here if we may need to expand conversion
8804 -- If the operand of the type conversion is an arithmetic operation on
8805 -- signed integers, and the based type of the signed integer type in
8806 -- question is smaller than Standard.Integer, we promote both of the
8807 -- operands to type Integer.
8809 -- For example, if we have
8811 -- target-type (opnd1 + opnd2)
8813 -- and opnd1 and opnd2 are of type short integer, then we rewrite
8816 -- target-type (integer(opnd1) + integer(opnd2))
8818 -- We do this because we are always allowed to compute in a larger type
8819 -- if we do the right thing with the result, and in this case we are
8820 -- going to do a conversion which will do an appropriate check to make
8821 -- sure that things are in range of the target type in any case. This
8822 -- avoids some unnecessary intermediate overflows.
8824 -- We might consider a similar transformation in the case where the
8825 -- target is a real type or a 64-bit integer type, and the operand
8826 -- is an arithmetic operation using a 32-bit integer type. However,
8827 -- we do not bother with this case, because it could cause significant
8828 -- inefficiencies on 32-bit machines. On a 64-bit machine it would be
8829 -- much cheaper, but we don't want different behavior on 32-bit and
8830 -- 64-bit machines. Note that the exclusion of the 64-bit case also
8831 -- handles the configurable run-time cases where 64-bit arithmetic
8832 -- may simply be unavailable.
8834 -- Note: this circuit is partially redundant with respect to the circuit
8835 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
8836 -- the processing here. Also we still need the Checks circuit, since we
8837 -- have to be sure not to generate junk overflow checks in the first
8838 -- place, since it would be trick to remove them here!
8840 if Integer_Promotion_Possible (N) then
8842 -- All conditions met, go ahead with transformation
8850 Make_Type_Conversion (Loc,
8851 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8852 Expression => Relocate_Node (Right_Opnd (Operand)));
8854 Opnd := New_Op_Node (Nkind (Operand), Loc);
8855 Set_Right_Opnd (Opnd, R);
8857 if Nkind (Operand) in N_Binary_Op then
8859 Make_Type_Conversion (Loc,
8860 Subtype_Mark => New_Reference_To (Standard_Integer, Loc),
8861 Expression => Relocate_Node (Left_Opnd (Operand)));
8863 Set_Left_Opnd (Opnd, L);
8867 Make_Type_Conversion (Loc,
8868 Subtype_Mark => Relocate_Node (Subtype_Mark (N)),
8869 Expression => Opnd));
8871 Analyze_And_Resolve (N, Target_Type);
8876 -- Do validity check if validity checking operands
8878 if Validity_Checks_On
8879 and then Validity_Check_Operands
8881 Ensure_Valid (Operand);
8884 -- Special case of converting from non-standard boolean type
8886 if Is_Boolean_Type (Operand_Type)
8887 and then (Nonzero_Is_True (Operand_Type))
8889 Adjust_Condition (Operand);
8890 Set_Etype (Operand, Standard_Boolean);
8891 Operand_Type := Standard_Boolean;
8894 -- Case of converting to an access type
8896 if Is_Access_Type (Target_Type) then
8898 -- Apply an accessibility check when the conversion operand is an
8899 -- access parameter (or a renaming thereof), unless conversion was
8900 -- expanded from an Unchecked_ or Unrestricted_Access attribute.
8901 -- Note that other checks may still need to be applied below (such
8902 -- as tagged type checks).
8904 if Is_Entity_Name (Operand)
8905 and then Has_Extra_Accessibility (Entity (Operand))
8906 and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type
8907 and then (Nkind (Original_Node (N)) /= N_Attribute_Reference
8908 or else Attribute_Name (Original_Node (N)) = Name_Access)
8910 Apply_Accessibility_Check
8911 (Operand, Target_Type, Insert_Node => Operand);
8913 -- If the level of the operand type is statically deeper than the
8914 -- level of the target type, then force Program_Error. Note that this
8915 -- can only occur for cases where the attribute is within the body of
8916 -- an instantiation (otherwise the conversion will already have been
8917 -- rejected as illegal). Note: warnings are issued by the analyzer
8918 -- for the instance cases.
8920 elsif In_Instance_Body
8921 and then Type_Access_Level (Operand_Type) >
8922 Type_Access_Level (Target_Type)
8924 Raise_Accessibility_Error;
8926 -- When the operand is a selected access discriminant the check needs
8927 -- to be made against the level of the object denoted by the prefix
8928 -- of the selected name. Force Program_Error for this case as well
8929 -- (this accessibility violation can only happen if within the body
8930 -- of an instantiation).
8932 elsif In_Instance_Body
8933 and then Ekind (Operand_Type) = E_Anonymous_Access_Type
8934 and then Nkind (Operand) = N_Selected_Component
8935 and then Object_Access_Level (Operand) >
8936 Type_Access_Level (Target_Type)
8938 Raise_Accessibility_Error;
8943 -- Case of conversions of tagged types and access to tagged types
8945 -- When needed, that is to say when the expression is class-wide, Add
8946 -- runtime a tag check for (strict) downward conversion by using the
8947 -- membership test, generating:
8949 -- [constraint_error when Operand not in Target_Type'Class]
8951 -- or in the access type case
8953 -- [constraint_error
8954 -- when Operand /= null
8955 -- and then Operand.all not in
8956 -- Designated_Type (Target_Type)'Class]
8958 if (Is_Access_Type (Target_Type)
8959 and then Is_Tagged_Type (Designated_Type (Target_Type)))
8960 or else Is_Tagged_Type (Target_Type)
8962 -- Do not do any expansion in the access type case if the parent is a
8963 -- renaming, since this is an error situation which will be caught by
8964 -- Sem_Ch8, and the expansion can interfere with this error check.
8966 if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then
8970 -- Otherwise, proceed with processing tagged conversion
8972 Tagged_Conversion : declare
8973 Actual_Op_Typ : Entity_Id;
8974 Actual_Targ_Typ : Entity_Id;
8975 Make_Conversion : Boolean := False;
8976 Root_Op_Typ : Entity_Id;
8978 procedure Make_Tag_Check (Targ_Typ : Entity_Id);
8979 -- Create a membership check to test whether Operand is a member
8980 -- of Targ_Typ. If the original Target_Type is an access, include
8981 -- a test for null value. The check is inserted at N.
8983 --------------------
8984 -- Make_Tag_Check --
8985 --------------------
8987 procedure Make_Tag_Check (Targ_Typ : Entity_Id) is
8992 -- [Constraint_Error
8993 -- when Operand /= null
8994 -- and then Operand.all not in Targ_Typ]
8996 if Is_Access_Type (Target_Type) then
9001 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
9002 Right_Opnd => Make_Null (Loc)),
9007 Make_Explicit_Dereference (Loc,
9008 Prefix => Duplicate_Subexpr_No_Checks (Operand)),
9009 Right_Opnd => New_Reference_To (Targ_Typ, Loc)));
9012 -- [Constraint_Error when Operand not in Targ_Typ]
9017 Left_Opnd => Duplicate_Subexpr_No_Checks (Operand),
9018 Right_Opnd => New_Reference_To (Targ_Typ, Loc));
9022 Make_Raise_Constraint_Error (Loc,
9024 Reason => CE_Tag_Check_Failed));
9027 -- Start of processing for Tagged_Conversion
9030 -- Handle entities from the limited view
9032 if Is_Access_Type (Operand_Type) then
9034 Available_View (Designated_Type (Operand_Type));
9036 Actual_Op_Typ := Operand_Type;
9039 if Is_Access_Type (Target_Type) then
9041 Available_View (Designated_Type (Target_Type));
9043 Actual_Targ_Typ := Target_Type;
9046 Root_Op_Typ := Root_Type (Actual_Op_Typ);
9048 -- Ada 2005 (AI-251): Handle interface type conversion
9050 if Is_Interface (Actual_Op_Typ) then
9051 Expand_Interface_Conversion (N, Is_Static => False);
9055 if not Tag_Checks_Suppressed (Actual_Targ_Typ) then
9057 -- Create a runtime tag check for a downward class-wide type
9060 if Is_Class_Wide_Type (Actual_Op_Typ)
9061 and then Actual_Op_Typ /= Actual_Targ_Typ
9062 and then Root_Op_Typ /= Actual_Targ_Typ
9063 and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ,
9064 Use_Full_View => True)
9066 Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ));
9067 Make_Conversion := True;
9070 -- AI05-0073: If the result subtype of the function is defined
9071 -- by an access_definition designating a specific tagged type
9072 -- T, a check is made that the result value is null or the tag
9073 -- of the object designated by the result value identifies T.
9074 -- Constraint_Error is raised if this check fails.
9076 if Nkind (Parent (N)) = Sinfo.N_Return_Statement then
9079 Func_Typ : Entity_Id;
9082 -- Climb scope stack looking for the enclosing function
9084 Func := Current_Scope;
9085 while Present (Func)
9086 and then Ekind (Func) /= E_Function
9088 Func := Scope (Func);
9091 -- The function's return subtype must be defined using
9092 -- an access definition.
9094 if Nkind (Result_Definition (Parent (Func))) =
9097 Func_Typ := Directly_Designated_Type (Etype (Func));
9099 -- The return subtype denotes a specific tagged type,
9100 -- in other words, a non class-wide type.
9102 if Is_Tagged_Type (Func_Typ)
9103 and then not Is_Class_Wide_Type (Func_Typ)
9105 Make_Tag_Check (Actual_Targ_Typ);
9106 Make_Conversion := True;
9112 -- We have generated a tag check for either a class-wide type
9113 -- conversion or for AI05-0073.
9115 if Make_Conversion then
9120 Make_Unchecked_Type_Conversion (Loc,
9121 Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
9122 Expression => Relocate_Node (Expression (N)));
9124 Analyze_And_Resolve (N, Target_Type);
9128 end Tagged_Conversion;
9130 -- Case of other access type conversions
9132 elsif Is_Access_Type (Target_Type) then
9133 Apply_Constraint_Check (Operand, Target_Type);
9135 -- Case of conversions from a fixed-point type
9137 -- These conversions require special expansion and processing, found in
9138 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
9139 -- since from a semantic point of view, these are simple integer
9140 -- conversions, which do not need further processing.
9142 elsif Is_Fixed_Point_Type (Operand_Type)
9143 and then not Conversion_OK (N)
9145 -- We should never see universal fixed at this case, since the
9146 -- expansion of the constituent divide or multiply should have
9147 -- eliminated the explicit mention of universal fixed.
9149 pragma Assert (Operand_Type /= Universal_Fixed);
9151 -- Check for special case of the conversion to universal real that
9152 -- occurs as a result of the use of a round attribute. In this case,
9153 -- the real type for the conversion is taken from the target type of
9154 -- the Round attribute and the result must be marked as rounded.
9156 if Target_Type = Universal_Real
9157 and then Nkind (Parent (N)) = N_Attribute_Reference
9158 and then Attribute_Name (Parent (N)) = Name_Round
9160 Set_Rounded_Result (N);
9161 Set_Etype (N, Etype (Parent (N)));
9164 -- Otherwise do correct fixed-conversion, but skip these if the
9165 -- Conversion_OK flag is set, because from a semantic point of view
9166 -- these are simple integer conversions needing no further processing
9167 -- (the backend will simply treat them as integers).
9169 if not Conversion_OK (N) then
9170 if Is_Fixed_Point_Type (Etype (N)) then
9171 Expand_Convert_Fixed_To_Fixed (N);
9174 elsif Is_Integer_Type (Etype (N)) then
9175 Expand_Convert_Fixed_To_Integer (N);
9178 pragma Assert (Is_Floating_Point_Type (Etype (N)));
9179 Expand_Convert_Fixed_To_Float (N);
9184 -- Case of conversions to a fixed-point type
9186 -- These conversions require special expansion and processing, found in
9187 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
9188 -- since from a semantic point of view, these are simple integer
9189 -- conversions, which do not need further processing.
9191 elsif Is_Fixed_Point_Type (Target_Type)
9192 and then not Conversion_OK (N)
9194 if Is_Integer_Type (Operand_Type) then
9195 Expand_Convert_Integer_To_Fixed (N);
9198 pragma Assert (Is_Floating_Point_Type (Operand_Type));
9199 Expand_Convert_Float_To_Fixed (N);
9203 -- Case of float-to-integer conversions
9205 -- We also handle float-to-fixed conversions with Conversion_OK set
9206 -- since semantically the fixed-point target is treated as though it
9207 -- were an integer in such cases.
9209 elsif Is_Floating_Point_Type (Operand_Type)
9211 (Is_Integer_Type (Target_Type)
9213 (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N)))
9215 -- One more check here, gcc is still not able to do conversions of
9216 -- this type with proper overflow checking, and so gigi is doing an
9217 -- approximation of what is required by doing floating-point compares
9218 -- with the end-point. But that can lose precision in some cases, and
9219 -- give a wrong result. Converting the operand to Universal_Real is
9220 -- helpful, but still does not catch all cases with 64-bit integers
9221 -- on targets with only 64-bit floats.
9223 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
9224 -- Can this code be removed ???
9226 if Do_Range_Check (Operand) then
9228 Make_Type_Conversion (Loc,
9230 New_Occurrence_Of (Universal_Real, Loc),
9232 Relocate_Node (Operand)));
9234 Set_Etype (Operand, Universal_Real);
9235 Enable_Range_Check (Operand);
9236 Set_Do_Range_Check (Expression (Operand), False);
9239 -- Case of array conversions
9241 -- Expansion of array conversions, add required length/range checks but
9242 -- only do this if there is no change of representation. For handling of
9243 -- this case, see Handle_Changed_Representation.
9245 elsif Is_Array_Type (Target_Type) then
9246 if Is_Constrained (Target_Type) then
9247 Apply_Length_Check (Operand, Target_Type);
9249 Apply_Range_Check (Operand, Target_Type);
9252 Handle_Changed_Representation;
9254 -- Case of conversions of discriminated types
9256 -- Add required discriminant checks if target is constrained. Again this
9257 -- change is skipped if we have a change of representation.
9259 elsif Has_Discriminants (Target_Type)
9260 and then Is_Constrained (Target_Type)
9262 Apply_Discriminant_Check (Operand, Target_Type);
9263 Handle_Changed_Representation;
9265 -- Case of all other record conversions. The only processing required
9266 -- is to check for a change of representation requiring the special
9267 -- assignment processing.
9269 elsif Is_Record_Type (Target_Type) then
9271 -- Ada 2005 (AI-216): Program_Error is raised when converting from
9272 -- a derived Unchecked_Union type to an unconstrained type that is
9273 -- not Unchecked_Union if the operand lacks inferable discriminants.
9275 if Is_Derived_Type (Operand_Type)
9276 and then Is_Unchecked_Union (Base_Type (Operand_Type))
9277 and then not Is_Constrained (Target_Type)
9278 and then not Is_Unchecked_Union (Base_Type (Target_Type))
9279 and then not Has_Inferable_Discriminants (Operand)
9281 -- To prevent Gigi from generating illegal code, we generate a
9282 -- Program_Error node, but we give it the target type of the
9286 PE : constant Node_Id := Make_Raise_Program_Error (Loc,
9287 Reason => PE_Unchecked_Union_Restriction);
9290 Set_Etype (PE, Target_Type);
9295 Handle_Changed_Representation;
9298 -- Case of conversions of enumeration types
9300 elsif Is_Enumeration_Type (Target_Type) then
9302 -- Special processing is required if there is a change of
9303 -- representation (from enumeration representation clauses).
9305 if not Same_Representation (Target_Type, Operand_Type) then
9307 -- Convert: x(y) to x'val (ytyp'val (y))
9310 Make_Attribute_Reference (Loc,
9311 Prefix => New_Occurrence_Of (Target_Type, Loc),
9312 Attribute_Name => Name_Val,
9313 Expressions => New_List (
9314 Make_Attribute_Reference (Loc,
9315 Prefix => New_Occurrence_Of (Operand_Type, Loc),
9316 Attribute_Name => Name_Pos,
9317 Expressions => New_List (Operand)))));
9319 Analyze_And_Resolve (N, Target_Type);
9322 -- Case of conversions to floating-point
9324 elsif Is_Floating_Point_Type (Target_Type) then
9328 -- At this stage, either the conversion node has been transformed into
9329 -- some other equivalent expression, or left as a conversion that can be
9330 -- handled by Gigi, in the following cases:
9332 -- Conversions with no change of representation or type
9334 -- Numeric conversions involving integer, floating- and fixed-point
9335 -- values. Fixed-point values are allowed only if Conversion_OK is
9336 -- set, i.e. if the fixed-point values are to be treated as integers.
9338 -- No other conversions should be passed to Gigi
9340 -- Check: are these rules stated in sinfo??? if so, why restate here???
9342 -- The only remaining step is to generate a range check if we still have
9343 -- a type conversion at this stage and Do_Range_Check is set. For now we
9344 -- do this only for conversions of discrete types.
9346 if Nkind (N) = N_Type_Conversion
9347 and then Is_Discrete_Type (Etype (N))
9350 Expr : constant Node_Id := Expression (N);
9355 if Do_Range_Check (Expr)
9356 and then Is_Discrete_Type (Etype (Expr))
9358 Set_Do_Range_Check (Expr, False);
9360 -- Before we do a range check, we have to deal with treating a
9361 -- fixed-point operand as an integer. The way we do this is
9362 -- simply to do an unchecked conversion to an appropriate
9363 -- integer type large enough to hold the result.
9365 -- This code is not active yet, because we are only dealing
9366 -- with discrete types so far ???
9368 if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer
9369 and then Treat_Fixed_As_Integer (Expr)
9371 Ftyp := Base_Type (Etype (Expr));
9373 if Esize (Ftyp) >= Esize (Standard_Integer) then
9374 Ityp := Standard_Long_Long_Integer;
9376 Ityp := Standard_Integer;
9379 Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr));
9382 -- Reset overflow flag, since the range check will include
9383 -- dealing with possible overflow, and generate the check. If
9384 -- Address is either a source type or target type, suppress
9385 -- range check to avoid typing anomalies when it is a visible
9388 Set_Do_Overflow_Check (N, False);
9389 if not Is_Descendent_Of_Address (Etype (Expr))
9390 and then not Is_Descendent_Of_Address (Target_Type)
9392 Generate_Range_Check
9393 (Expr, Target_Type, CE_Range_Check_Failed);
9399 -- Final step, if the result is a type conversion involving Vax_Float
9400 -- types, then it is subject for further special processing.
9402 if Nkind (N) = N_Type_Conversion
9403 and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type))
9405 Expand_Vax_Conversion (N);
9409 -- Here at end of processing
9412 -- Apply predicate check if required. Note that we can't just call
9413 -- Apply_Predicate_Check here, because the type looks right after
9414 -- the conversion and it would omit the check. The Comes_From_Source
9415 -- guard is necessary to prevent infinite recursions when we generate
9416 -- internal conversions for the purpose of checking predicates.
9418 if Present (Predicate_Function (Target_Type))
9419 and then Target_Type /= Operand_Type
9420 and then Comes_From_Source (N)
9423 New_Expr : constant Node_Id := Duplicate_Subexpr (N);
9426 -- Avoid infinite recursion on the subsequent expansion of
9427 -- of the copy of the original type conversion.
9429 Set_Comes_From_Source (New_Expr, False);
9430 Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr));
9433 end Expand_N_Type_Conversion;
9435 -----------------------------------
9436 -- Expand_N_Unchecked_Expression --
9437 -----------------------------------
9439 -- Remove the unchecked expression node from the tree. Its job was simply
9440 -- to make sure that its constituent expression was handled with checks
9441 -- off, and now that that is done, we can remove it from the tree, and
9442 -- indeed must, since Gigi does not expect to see these nodes.
9444 procedure Expand_N_Unchecked_Expression (N : Node_Id) is
9445 Exp : constant Node_Id := Expression (N);
9447 Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp));
9449 end Expand_N_Unchecked_Expression;
9451 ----------------------------------------
9452 -- Expand_N_Unchecked_Type_Conversion --
9453 ----------------------------------------
9455 -- If this cannot be handled by Gigi and we haven't already made a
9456 -- temporary for it, do it now.
9458 procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is
9459 Target_Type : constant Entity_Id := Etype (N);
9460 Operand : constant Node_Id := Expression (N);
9461 Operand_Type : constant Entity_Id := Etype (Operand);
9464 -- Nothing at all to do if conversion is to the identical type so remove
9465 -- the conversion completely, it is useless, except that it may carry
9466 -- an Assignment_OK indication which must be propagated to the operand.
9468 if Operand_Type = Target_Type then
9470 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
9472 if Assignment_OK (N) then
9473 Set_Assignment_OK (Operand);
9476 Rewrite (N, Relocate_Node (Operand));
9480 -- If we have a conversion of a compile time known value to a target
9481 -- type and the value is in range of the target type, then we can simply
9482 -- replace the construct by an integer literal of the correct type. We
9483 -- only apply this to integer types being converted. Possibly it may
9484 -- apply in other cases, but it is too much trouble to worry about.
9486 -- Note that we do not do this transformation if the Kill_Range_Check
9487 -- flag is set, since then the value may be outside the expected range.
9488 -- This happens in the Normalize_Scalars case.
9490 -- We also skip this if either the target or operand type is biased
9491 -- because in this case, the unchecked conversion is supposed to
9492 -- preserve the bit pattern, not the integer value.
9494 if Is_Integer_Type (Target_Type)
9495 and then not Has_Biased_Representation (Target_Type)
9496 and then Is_Integer_Type (Operand_Type)
9497 and then not Has_Biased_Representation (Operand_Type)
9498 and then Compile_Time_Known_Value (Operand)
9499 and then not Kill_Range_Check (N)
9502 Val : constant Uint := Expr_Value (Operand);
9505 if Compile_Time_Known_Value (Type_Low_Bound (Target_Type))
9507 Compile_Time_Known_Value (Type_High_Bound (Target_Type))
9509 Val >= Expr_Value (Type_Low_Bound (Target_Type))
9511 Val <= Expr_Value (Type_High_Bound (Target_Type))
9513 Rewrite (N, Make_Integer_Literal (Sloc (N), Val));
9515 -- If Address is the target type, just set the type to avoid a
9516 -- spurious type error on the literal when Address is a visible
9519 if Is_Descendent_Of_Address (Target_Type) then
9520 Set_Etype (N, Target_Type);
9522 Analyze_And_Resolve (N, Target_Type);
9530 -- Nothing to do if conversion is safe
9532 if Safe_Unchecked_Type_Conversion (N) then
9536 -- Otherwise force evaluation unless Assignment_OK flag is set (this
9537 -- flag indicates ??? -- more comments needed here)
9539 if Assignment_OK (N) then
9542 Force_Evaluation (N);
9544 end Expand_N_Unchecked_Type_Conversion;
9546 ----------------------------
9547 -- Expand_Record_Equality --
9548 ----------------------------
9550 -- For non-variant records, Equality is expanded when needed into:
9552 -- and then Lhs.Discr1 = Rhs.Discr1
9554 -- and then Lhs.Discrn = Rhs.Discrn
9555 -- and then Lhs.Cmp1 = Rhs.Cmp1
9557 -- and then Lhs.Cmpn = Rhs.Cmpn
9559 -- The expression is folded by the back-end for adjacent fields. This
9560 -- function is called for tagged record in only one occasion: for imple-
9561 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
9562 -- otherwise the primitive "=" is used directly.
9564 function Expand_Record_Equality
9569 Bodies : List_Id) return Node_Id
9571 Loc : constant Source_Ptr := Sloc (Nod);
9576 First_Time : Boolean := True;
9578 function Suitable_Element (C : Entity_Id) return Entity_Id;
9579 -- Return the first field to compare beginning with C, skipping the
9580 -- inherited components.
9582 ----------------------
9583 -- Suitable_Element --
9584 ----------------------
9586 function Suitable_Element (C : Entity_Id) return Entity_Id is
9591 elsif Ekind (C) /= E_Discriminant
9592 and then Ekind (C) /= E_Component
9594 return Suitable_Element (Next_Entity (C));
9596 elsif Is_Tagged_Type (Typ)
9597 and then C /= Original_Record_Component (C)
9599 return Suitable_Element (Next_Entity (C));
9601 elsif Chars (C) = Name_uTag then
9602 return Suitable_Element (Next_Entity (C));
9604 -- The .NET/JVM version of type Root_Controlled contains two fields
9605 -- which should not be considered part of the object. To achieve
9606 -- proper equiality between two controlled objects on .NET/JVM, skip
9607 -- field _parent whenever it is of type Root_Controlled.
9609 elsif Chars (C) = Name_uParent
9610 and then VM_Target /= No_VM
9611 and then Etype (C) = RTE (RE_Root_Controlled)
9613 return Suitable_Element (Next_Entity (C));
9615 elsif Is_Interface (Etype (C)) then
9616 return Suitable_Element (Next_Entity (C));
9621 end Suitable_Element;
9623 -- Start of processing for Expand_Record_Equality
9626 -- Generates the following code: (assuming that Typ has one Discr and
9627 -- component C2 is also a record)
9630 -- and then Lhs.Discr1 = Rhs.Discr1
9631 -- and then Lhs.C1 = Rhs.C1
9632 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
9634 -- and then Lhs.Cmpn = Rhs.Cmpn
9636 Result := New_Reference_To (Standard_True, Loc);
9637 C := Suitable_Element (First_Entity (Typ));
9638 while Present (C) loop
9646 First_Time := False;
9650 New_Lhs := New_Copy_Tree (Lhs);
9651 New_Rhs := New_Copy_Tree (Rhs);
9655 Expand_Composite_Equality (Nod, Etype (C),
9657 Make_Selected_Component (Loc,
9659 Selector_Name => New_Reference_To (C, Loc)),
9661 Make_Selected_Component (Loc,
9663 Selector_Name => New_Reference_To (C, Loc)),
9666 -- If some (sub)component is an unchecked_union, the whole
9667 -- operation will raise program error.
9669 if Nkind (Check) = N_Raise_Program_Error then
9671 Set_Etype (Result, Standard_Boolean);
9676 Left_Opnd => Result,
9677 Right_Opnd => Check);
9681 C := Suitable_Element (Next_Entity (C));
9685 end Expand_Record_Equality;
9687 ---------------------------
9688 -- Expand_Set_Membership --
9689 ---------------------------
9691 procedure Expand_Set_Membership (N : Node_Id) is
9692 Lop : constant Node_Id := Left_Opnd (N);
9696 function Make_Cond (Alt : Node_Id) return Node_Id;
9697 -- If the alternative is a subtype mark, create a simple membership
9698 -- test. Otherwise create an equality test for it.
9704 function Make_Cond (Alt : Node_Id) return Node_Id is
9706 L : constant Node_Id := New_Copy (Lop);
9707 R : constant Node_Id := Relocate_Node (Alt);
9710 if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt)))
9711 or else Nkind (Alt) = N_Range
9714 Make_In (Sloc (Alt),
9719 Make_Op_Eq (Sloc (Alt),
9727 -- Start of processing for Expand_Set_Membership
9730 Remove_Side_Effects (Lop);
9732 Alt := Last (Alternatives (N));
9733 Res := Make_Cond (Alt);
9736 while Present (Alt) loop
9738 Make_Or_Else (Sloc (Alt),
9739 Left_Opnd => Make_Cond (Alt),
9745 Analyze_And_Resolve (N, Standard_Boolean);
9746 end Expand_Set_Membership;
9748 -----------------------------------
9749 -- Expand_Short_Circuit_Operator --
9750 -----------------------------------
9752 -- Deal with special expansion if actions are present for the right operand
9753 -- and deal with optimizing case of arguments being True or False. We also
9754 -- deal with the special case of non-standard boolean values.
9756 procedure Expand_Short_Circuit_Operator (N : Node_Id) is
9757 Loc : constant Source_Ptr := Sloc (N);
9758 Typ : constant Entity_Id := Etype (N);
9759 Left : constant Node_Id := Left_Opnd (N);
9760 Right : constant Node_Id := Right_Opnd (N);
9761 LocR : constant Source_Ptr := Sloc (Right);
9764 Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else;
9765 Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value);
9766 -- If Left = Shortcut_Value then Right need not be evaluated
9768 function Make_Test_Expr (Opnd : Node_Id) return Node_Id;
9769 -- For Opnd a boolean expression, return a Boolean expression equivalent
9770 -- to Opnd /= Shortcut_Value.
9772 --------------------
9773 -- Make_Test_Expr --
9774 --------------------
9776 function Make_Test_Expr (Opnd : Node_Id) return Node_Id is
9778 if Shortcut_Value then
9779 return Make_Op_Not (Sloc (Opnd), Opnd);
9786 -- Entity for a temporary variable holding the value of the operator,
9787 -- used for expansion in the case where actions are present.
9789 -- Start of processing for Expand_Short_Circuit_Operator
9792 -- Deal with non-standard booleans
9794 if Is_Boolean_Type (Typ) then
9795 Adjust_Condition (Left);
9796 Adjust_Condition (Right);
9797 Set_Etype (N, Standard_Boolean);
9800 -- Check for cases where left argument is known to be True or False
9802 if Compile_Time_Known_Value (Left) then
9804 -- Mark SCO for left condition as compile time known
9806 if Generate_SCO and then Comes_From_Source (Left) then
9807 Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True);
9810 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
9811 -- Any actions associated with Right will be executed unconditionally
9812 -- and can thus be inserted into the tree unconditionally.
9814 if Expr_Value_E (Left) /= Shortcut_Ent then
9815 if Present (Actions (N)) then
9816 Insert_Actions (N, Actions (N));
9821 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
9822 -- In this case we can forget the actions associated with Right,
9823 -- since they will never be executed.
9826 Kill_Dead_Code (Right);
9827 Kill_Dead_Code (Actions (N));
9828 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9831 Adjust_Result_Type (N, Typ);
9835 -- If Actions are present for the right operand, we have to do some
9836 -- special processing. We can't just let these actions filter back into
9837 -- code preceding the short circuit (which is what would have happened
9838 -- if we had not trapped them in the short-circuit form), since they
9839 -- must only be executed if the right operand of the short circuit is
9840 -- executed and not otherwise.
9842 -- the temporary variable C.
9844 if Present (Actions (N)) then
9845 Actlist := Actions (N);
9847 -- The old approach is to expand:
9849 -- left AND THEN right
9853 -- C : Boolean := False;
9861 -- and finally rewrite the operator into a reference to C. Similarly
9862 -- for left OR ELSE right, with negated values. Note that this
9863 -- rewrite causes some difficulties for coverage analysis because
9864 -- of the introduction of the new variable C, which obscures the
9865 -- structure of the test.
9867 -- We use this "old approach" if use of N_Expression_With_Actions
9868 -- is False (see description in Opt of when this is or is not set).
9870 if not Use_Expression_With_Actions then
9871 Op_Var := Make_Temporary (Loc, 'C', Related_Node => N);
9874 Make_Object_Declaration (Loc,
9875 Defining_Identifier =>
9877 Object_Definition =>
9878 New_Occurrence_Of (Standard_Boolean, Loc),
9880 New_Occurrence_Of (Shortcut_Ent, Loc)));
9883 Make_Implicit_If_Statement (Right,
9884 Condition => Make_Test_Expr (Right),
9885 Then_Statements => New_List (
9886 Make_Assignment_Statement (LocR,
9887 Name => New_Occurrence_Of (Op_Var, LocR),
9890 (Boolean_Literals (not Shortcut_Value), LocR)))));
9893 Make_Implicit_If_Statement (Left,
9894 Condition => Make_Test_Expr (Left),
9895 Then_Statements => Actlist));
9897 Rewrite (N, New_Occurrence_Of (Op_Var, Loc));
9898 Analyze_And_Resolve (N, Standard_Boolean);
9900 -- The new approach, activated for now by the use of debug flag
9901 -- -gnatd.X is to use the new Expression_With_Actions node for the
9902 -- right operand of the short-circuit form. This should solve the
9903 -- traceability problems for coverage analysis.
9907 Make_Expression_With_Actions (LocR,
9908 Expression => Relocate_Node (Right),
9909 Actions => Actlist));
9910 Set_Actions (N, No_List);
9911 Analyze_And_Resolve (Right, Standard_Boolean);
9914 Adjust_Result_Type (N, Typ);
9918 -- No actions present, check for cases of right argument True/False
9920 if Compile_Time_Known_Value (Right) then
9922 -- Mark SCO for left condition as compile time known
9924 if Generate_SCO and then Comes_From_Source (Right) then
9925 Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True);
9928 -- Change (Left and then True), (Left or else False) to Left.
9929 -- Note that we know there are no actions associated with the right
9930 -- operand, since we just checked for this case above.
9932 if Expr_Value_E (Right) /= Shortcut_Ent then
9935 -- Change (Left and then False), (Left or else True) to Right,
9936 -- making sure to preserve any side effects associated with the Left
9940 Remove_Side_Effects (Left);
9941 Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc));
9945 Adjust_Result_Type (N, Typ);
9946 end Expand_Short_Circuit_Operator;
9948 -------------------------------------
9949 -- Fixup_Universal_Fixed_Operation --
9950 -------------------------------------
9952 procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is
9953 Conv : constant Node_Id := Parent (N);
9956 -- We must have a type conversion immediately above us
9958 pragma Assert (Nkind (Conv) = N_Type_Conversion);
9960 -- Normally the type conversion gives our target type. The exception
9961 -- occurs in the case of the Round attribute, where the conversion
9962 -- will be to universal real, and our real type comes from the Round
9963 -- attribute (as well as an indication that we must round the result)
9965 if Nkind (Parent (Conv)) = N_Attribute_Reference
9966 and then Attribute_Name (Parent (Conv)) = Name_Round
9968 Set_Etype (N, Etype (Parent (Conv)));
9969 Set_Rounded_Result (N);
9971 -- Normal case where type comes from conversion above us
9974 Set_Etype (N, Etype (Conv));
9976 end Fixup_Universal_Fixed_Operation;
9978 ---------------------------------
9979 -- Has_Inferable_Discriminants --
9980 ---------------------------------
9982 function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
9984 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
9985 -- Determines whether the left-most prefix of a selected component is a
9986 -- formal parameter in a subprogram. Assumes N is a selected component.
9988 --------------------------------
9989 -- Prefix_Is_Formal_Parameter --
9990 --------------------------------
9992 function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
9993 Sel_Comp : Node_Id := N;
9996 -- Move to the left-most prefix by climbing up the tree
9998 while Present (Parent (Sel_Comp))
9999 and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
10001 Sel_Comp := Parent (Sel_Comp);
10004 return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
10005 end Prefix_Is_Formal_Parameter;
10007 -- Start of processing for Has_Inferable_Discriminants
10010 -- For identifiers and indexed components, it is sufficient to have a
10011 -- constrained Unchecked_Union nominal subtype.
10013 if Nkind_In (N, N_Identifier, N_Indexed_Component) then
10014 return Is_Unchecked_Union (Base_Type (Etype (N)))
10016 Is_Constrained (Etype (N));
10018 -- For selected components, the subtype of the selector must be a
10019 -- constrained Unchecked_Union. If the component is subject to a
10020 -- per-object constraint, then the enclosing object must have inferable
10023 elsif Nkind (N) = N_Selected_Component then
10024 if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
10026 -- A small hack. If we have a per-object constrained selected
10027 -- component of a formal parameter, return True since we do not
10028 -- know the actual parameter association yet.
10030 if Prefix_Is_Formal_Parameter (N) then
10034 -- Otherwise, check the enclosing object and the selector
10036 return Has_Inferable_Discriminants (Prefix (N))
10038 Has_Inferable_Discriminants (Selector_Name (N));
10041 -- The call to Has_Inferable_Discriminants will determine whether
10042 -- the selector has a constrained Unchecked_Union nominal type.
10044 return Has_Inferable_Discriminants (Selector_Name (N));
10046 -- A qualified expression has inferable discriminants if its subtype
10047 -- mark is a constrained Unchecked_Union subtype.
10049 elsif Nkind (N) = N_Qualified_Expression then
10050 return Is_Unchecked_Union (Subtype_Mark (N))
10052 Is_Constrained (Subtype_Mark (N));
10057 end Has_Inferable_Discriminants;
10059 -------------------------------
10060 -- Insert_Dereference_Action --
10061 -------------------------------
10063 procedure Insert_Dereference_Action (N : Node_Id) is
10064 Loc : constant Source_Ptr := Sloc (N);
10065 Typ : constant Entity_Id := Etype (N);
10066 Pool : constant Entity_Id := Associated_Storage_Pool (Typ);
10067 Pnod : constant Node_Id := Parent (N);
10069 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean;
10070 -- Return true if type of P is derived from Checked_Pool;
10072 -----------------------------
10073 -- Is_Checked_Storage_Pool --
10074 -----------------------------
10076 function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is
10085 while T /= Etype (T) loop
10086 if Is_RTE (T, RE_Checked_Pool) then
10094 end Is_Checked_Storage_Pool;
10096 -- Start of processing for Insert_Dereference_Action
10099 pragma Assert (Nkind (Pnod) = N_Explicit_Dereference);
10101 if not (Is_Checked_Storage_Pool (Pool)
10102 and then Comes_From_Source (Original_Node (Pnod)))
10108 Make_Procedure_Call_Statement (Loc,
10109 Name => New_Reference_To (
10110 Find_Prim_Op (Etype (Pool), Name_Dereference), Loc),
10112 Parameter_Associations => New_List (
10116 New_Reference_To (Pool, Loc),
10118 -- Storage_Address. We use the attribute Pool_Address, which uses
10119 -- the pointer itself to find the address of the object, and which
10120 -- handles unconstrained arrays properly by computing the address
10121 -- of the template. i.e. the correct address of the corresponding
10124 Make_Attribute_Reference (Loc,
10125 Prefix => Duplicate_Subexpr_Move_Checks (N),
10126 Attribute_Name => Name_Pool_Address),
10128 -- Size_In_Storage_Elements
10130 Make_Op_Divide (Loc,
10132 Make_Attribute_Reference (Loc,
10134 Make_Explicit_Dereference (Loc,
10135 Duplicate_Subexpr_Move_Checks (N)),
10136 Attribute_Name => Name_Size),
10138 Make_Integer_Literal (Loc, System_Storage_Unit)),
10142 Make_Attribute_Reference (Loc,
10144 Make_Explicit_Dereference (Loc,
10145 Duplicate_Subexpr_Move_Checks (N)),
10146 Attribute_Name => Name_Alignment))));
10149 when RE_Not_Available =>
10151 end Insert_Dereference_Action;
10153 --------------------------------
10154 -- Integer_Promotion_Possible --
10155 --------------------------------
10157 function Integer_Promotion_Possible (N : Node_Id) return Boolean is
10158 Operand : constant Node_Id := Expression (N);
10159 Operand_Type : constant Entity_Id := Etype (Operand);
10160 Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type);
10163 pragma Assert (Nkind (N) = N_Type_Conversion);
10167 -- We only do the transformation for source constructs. We assume
10168 -- that the expander knows what it is doing when it generates code.
10170 Comes_From_Source (N)
10172 -- If the operand type is Short_Integer or Short_Short_Integer,
10173 -- then we will promote to Integer, which is available on all
10174 -- targets, and is sufficient to ensure no intermediate overflow.
10175 -- Furthermore it is likely to be as efficient or more efficient
10176 -- than using the smaller type for the computation so we do this
10177 -- unconditionally.
10180 (Root_Operand_Type = Base_Type (Standard_Short_Integer)
10182 Root_Operand_Type = Base_Type (Standard_Short_Short_Integer))
10184 -- Test for interesting operation, which includes addition,
10185 -- division, exponentiation, multiplication, subtraction, absolute
10186 -- value and unary negation. Unary "+" is omitted since it is a
10187 -- no-op and thus can't overflow.
10189 and then Nkind_In (Operand, N_Op_Abs,
10196 end Integer_Promotion_Possible;
10198 ------------------------------
10199 -- Make_Array_Comparison_Op --
10200 ------------------------------
10202 -- This is a hand-coded expansion of the following generic function:
10205 -- type elem is (<>);
10206 -- type index is (<>);
10207 -- type a is array (index range <>) of elem;
10209 -- function Gnnn (X : a; Y: a) return boolean is
10210 -- J : index := Y'first;
10213 -- if X'length = 0 then
10216 -- elsif Y'length = 0 then
10220 -- for I in X'range loop
10221 -- if X (I) = Y (J) then
10222 -- if J = Y'last then
10225 -- J := index'succ (J);
10229 -- return X (I) > Y (J);
10233 -- return X'length > Y'length;
10237 -- Note that since we are essentially doing this expansion by hand, we
10238 -- do not need to generate an actual or formal generic part, just the
10239 -- instantiated function itself.
10241 function Make_Array_Comparison_Op
10243 Nod : Node_Id) return Node_Id
10245 Loc : constant Source_Ptr := Sloc (Nod);
10247 X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX);
10248 Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY);
10249 I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI);
10250 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10252 Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ)));
10254 Loop_Statement : Node_Id;
10255 Loop_Body : Node_Id;
10257 Inner_If : Node_Id;
10258 Final_Expr : Node_Id;
10259 Func_Body : Node_Id;
10260 Func_Name : Entity_Id;
10266 -- if J = Y'last then
10269 -- J := index'succ (J);
10273 Make_Implicit_If_Statement (Nod,
10276 Left_Opnd => New_Reference_To (J, Loc),
10278 Make_Attribute_Reference (Loc,
10279 Prefix => New_Reference_To (Y, Loc),
10280 Attribute_Name => Name_Last)),
10282 Then_Statements => New_List (
10283 Make_Exit_Statement (Loc)),
10287 Make_Assignment_Statement (Loc,
10288 Name => New_Reference_To (J, Loc),
10290 Make_Attribute_Reference (Loc,
10291 Prefix => New_Reference_To (Index, Loc),
10292 Attribute_Name => Name_Succ,
10293 Expressions => New_List (New_Reference_To (J, Loc))))));
10295 -- if X (I) = Y (J) then
10298 -- return X (I) > Y (J);
10302 Make_Implicit_If_Statement (Nod,
10306 Make_Indexed_Component (Loc,
10307 Prefix => New_Reference_To (X, Loc),
10308 Expressions => New_List (New_Reference_To (I, Loc))),
10311 Make_Indexed_Component (Loc,
10312 Prefix => New_Reference_To (Y, Loc),
10313 Expressions => New_List (New_Reference_To (J, Loc)))),
10315 Then_Statements => New_List (Inner_If),
10317 Else_Statements => New_List (
10318 Make_Simple_Return_Statement (Loc,
10322 Make_Indexed_Component (Loc,
10323 Prefix => New_Reference_To (X, Loc),
10324 Expressions => New_List (New_Reference_To (I, Loc))),
10327 Make_Indexed_Component (Loc,
10328 Prefix => New_Reference_To (Y, Loc),
10329 Expressions => New_List (
10330 New_Reference_To (J, Loc)))))));
10332 -- for I in X'range loop
10337 Make_Implicit_Loop_Statement (Nod,
10338 Identifier => Empty,
10340 Iteration_Scheme =>
10341 Make_Iteration_Scheme (Loc,
10342 Loop_Parameter_Specification =>
10343 Make_Loop_Parameter_Specification (Loc,
10344 Defining_Identifier => I,
10345 Discrete_Subtype_Definition =>
10346 Make_Attribute_Reference (Loc,
10347 Prefix => New_Reference_To (X, Loc),
10348 Attribute_Name => Name_Range))),
10350 Statements => New_List (Loop_Body));
10352 -- if X'length = 0 then
10354 -- elsif Y'length = 0 then
10357 -- for ... loop ... end loop;
10358 -- return X'length > Y'length;
10362 Make_Attribute_Reference (Loc,
10363 Prefix => New_Reference_To (X, Loc),
10364 Attribute_Name => Name_Length);
10367 Make_Attribute_Reference (Loc,
10368 Prefix => New_Reference_To (Y, Loc),
10369 Attribute_Name => Name_Length);
10373 Left_Opnd => Length1,
10374 Right_Opnd => Length2);
10377 Make_Implicit_If_Statement (Nod,
10381 Make_Attribute_Reference (Loc,
10382 Prefix => New_Reference_To (X, Loc),
10383 Attribute_Name => Name_Length),
10385 Make_Integer_Literal (Loc, 0)),
10389 Make_Simple_Return_Statement (Loc,
10390 Expression => New_Reference_To (Standard_False, Loc))),
10392 Elsif_Parts => New_List (
10393 Make_Elsif_Part (Loc,
10397 Make_Attribute_Reference (Loc,
10398 Prefix => New_Reference_To (Y, Loc),
10399 Attribute_Name => Name_Length),
10401 Make_Integer_Literal (Loc, 0)),
10405 Make_Simple_Return_Statement (Loc,
10406 Expression => New_Reference_To (Standard_True, Loc))))),
10408 Else_Statements => New_List (
10410 Make_Simple_Return_Statement (Loc,
10411 Expression => Final_Expr)));
10415 Formals := New_List (
10416 Make_Parameter_Specification (Loc,
10417 Defining_Identifier => X,
10418 Parameter_Type => New_Reference_To (Typ, Loc)),
10420 Make_Parameter_Specification (Loc,
10421 Defining_Identifier => Y,
10422 Parameter_Type => New_Reference_To (Typ, Loc)));
10424 -- function Gnnn (...) return boolean is
10425 -- J : index := Y'first;
10430 Func_Name := Make_Temporary (Loc, 'G');
10433 Make_Subprogram_Body (Loc,
10435 Make_Function_Specification (Loc,
10436 Defining_Unit_Name => Func_Name,
10437 Parameter_Specifications => Formals,
10438 Result_Definition => New_Reference_To (Standard_Boolean, Loc)),
10440 Declarations => New_List (
10441 Make_Object_Declaration (Loc,
10442 Defining_Identifier => J,
10443 Object_Definition => New_Reference_To (Index, Loc),
10445 Make_Attribute_Reference (Loc,
10446 Prefix => New_Reference_To (Y, Loc),
10447 Attribute_Name => Name_First))),
10449 Handled_Statement_Sequence =>
10450 Make_Handled_Sequence_Of_Statements (Loc,
10451 Statements => New_List (If_Stat)));
10454 end Make_Array_Comparison_Op;
10456 ---------------------------
10457 -- Make_Boolean_Array_Op --
10458 ---------------------------
10460 -- For logical operations on boolean arrays, expand in line the following,
10461 -- replacing 'and' with 'or' or 'xor' where needed:
10463 -- function Annn (A : typ; B: typ) return typ is
10466 -- for J in A'range loop
10467 -- C (J) := A (J) op B (J);
10472 -- Here typ is the boolean array type
10474 function Make_Boolean_Array_Op
10476 N : Node_Id) return Node_Id
10478 Loc : constant Source_Ptr := Sloc (N);
10480 A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA);
10481 B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB);
10482 C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC);
10483 J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ);
10491 Func_Name : Entity_Id;
10492 Func_Body : Node_Id;
10493 Loop_Statement : Node_Id;
10497 Make_Indexed_Component (Loc,
10498 Prefix => New_Reference_To (A, Loc),
10499 Expressions => New_List (New_Reference_To (J, Loc)));
10502 Make_Indexed_Component (Loc,
10503 Prefix => New_Reference_To (B, Loc),
10504 Expressions => New_List (New_Reference_To (J, Loc)));
10507 Make_Indexed_Component (Loc,
10508 Prefix => New_Reference_To (C, Loc),
10509 Expressions => New_List (New_Reference_To (J, Loc)));
10511 if Nkind (N) = N_Op_And then
10515 Right_Opnd => B_J);
10517 elsif Nkind (N) = N_Op_Or then
10521 Right_Opnd => B_J);
10527 Right_Opnd => B_J);
10531 Make_Implicit_Loop_Statement (N,
10532 Identifier => Empty,
10534 Iteration_Scheme =>
10535 Make_Iteration_Scheme (Loc,
10536 Loop_Parameter_Specification =>
10537 Make_Loop_Parameter_Specification (Loc,
10538 Defining_Identifier => J,
10539 Discrete_Subtype_Definition =>
10540 Make_Attribute_Reference (Loc,
10541 Prefix => New_Reference_To (A, Loc),
10542 Attribute_Name => Name_Range))),
10544 Statements => New_List (
10545 Make_Assignment_Statement (Loc,
10547 Expression => Op)));
10549 Formals := New_List (
10550 Make_Parameter_Specification (Loc,
10551 Defining_Identifier => A,
10552 Parameter_Type => New_Reference_To (Typ, Loc)),
10554 Make_Parameter_Specification (Loc,
10555 Defining_Identifier => B,
10556 Parameter_Type => New_Reference_To (Typ, Loc)));
10558 Func_Name := Make_Temporary (Loc, 'A');
10559 Set_Is_Inlined (Func_Name);
10562 Make_Subprogram_Body (Loc,
10564 Make_Function_Specification (Loc,
10565 Defining_Unit_Name => Func_Name,
10566 Parameter_Specifications => Formals,
10567 Result_Definition => New_Reference_To (Typ, Loc)),
10569 Declarations => New_List (
10570 Make_Object_Declaration (Loc,
10571 Defining_Identifier => C,
10572 Object_Definition => New_Reference_To (Typ, Loc))),
10574 Handled_Statement_Sequence =>
10575 Make_Handled_Sequence_Of_Statements (Loc,
10576 Statements => New_List (
10578 Make_Simple_Return_Statement (Loc,
10579 Expression => New_Reference_To (C, Loc)))));
10582 end Make_Boolean_Array_Op;
10584 --------------------------------
10585 -- Optimize_Length_Comparison --
10586 --------------------------------
10588 procedure Optimize_Length_Comparison (N : Node_Id) is
10589 Loc : constant Source_Ptr := Sloc (N);
10590 Typ : constant Entity_Id := Etype (N);
10595 -- First and Last attribute reference nodes, which end up as left and
10596 -- right operands of the optimized result.
10599 -- True for comparison operand of zero
10602 -- Comparison operand, set only if Is_Zero is false
10605 -- Entity whose length is being compared
10608 -- Integer_Literal node for length attribute expression, or Empty
10609 -- if there is no such expression present.
10612 -- Type of array index to which 'Length is applied
10614 Op : Node_Kind := Nkind (N);
10615 -- Kind of comparison operator, gets flipped if operands backwards
10617 function Is_Optimizable (N : Node_Id) return Boolean;
10618 -- Tests N to see if it is an optimizable comparison value (defined as
10619 -- constant zero or one, or something else where the value is known to
10620 -- be positive and in the range of 32-bits, and where the corresponding
10621 -- Length value is also known to be 32-bits. If result is true, sets
10622 -- Is_Zero, Ityp, and Comp accordingly.
10624 function Is_Entity_Length (N : Node_Id) return Boolean;
10625 -- Tests if N is a length attribute applied to a simple entity. If so,
10626 -- returns True, and sets Ent to the entity, and Index to the integer
10627 -- literal provided as an attribute expression, or to Empty if none.
10628 -- Also returns True if the expression is a generated type conversion
10629 -- whose expression is of the desired form. This latter case arises
10630 -- when Apply_Universal_Integer_Attribute_Check installs a conversion
10631 -- to check for being in range, which is not needed in this context.
10632 -- Returns False if neither condition holds.
10634 function Prepare_64 (N : Node_Id) return Node_Id;
10635 -- Given a discrete expression, returns a Long_Long_Integer typed
10636 -- expression representing the underlying value of the expression.
10637 -- This is done with an unchecked conversion to the result type. We
10638 -- use unchecked conversion to handle the enumeration type case.
10640 ----------------------
10641 -- Is_Entity_Length --
10642 ----------------------
10644 function Is_Entity_Length (N : Node_Id) return Boolean is
10646 if Nkind (N) = N_Attribute_Reference
10647 and then Attribute_Name (N) = Name_Length
10648 and then Is_Entity_Name (Prefix (N))
10650 Ent := Entity (Prefix (N));
10652 if Present (Expressions (N)) then
10653 Index := First (Expressions (N));
10660 elsif Nkind (N) = N_Type_Conversion
10661 and then not Comes_From_Source (N)
10663 return Is_Entity_Length (Expression (N));
10668 end Is_Entity_Length;
10670 --------------------
10671 -- Is_Optimizable --
10672 --------------------
10674 function Is_Optimizable (N : Node_Id) return Boolean is
10682 if Compile_Time_Known_Value (N) then
10683 Val := Expr_Value (N);
10685 if Val = Uint_0 then
10690 elsif Val = Uint_1 then
10697 -- Here we have to make sure of being within 32-bits
10699 Determine_Range (N, OK, Lo, Hi, Assume_Valid => True);
10702 or else Lo < Uint_1
10703 or else Hi > UI_From_Int (Int'Last)
10708 -- Comparison value was within range, so now we must check the index
10709 -- value to make sure it is also within 32-bits.
10711 Indx := First_Index (Etype (Ent));
10713 if Present (Index) then
10714 for J in 2 .. UI_To_Int (Intval (Index)) loop
10719 Ityp := Etype (Indx);
10721 if Esize (Ityp) > 32 then
10728 end Is_Optimizable;
10734 function Prepare_64 (N : Node_Id) return Node_Id is
10736 return Unchecked_Convert_To (Standard_Long_Long_Integer, N);
10739 -- Start of processing for Optimize_Length_Comparison
10742 -- Nothing to do if not a comparison
10744 if Op not in N_Op_Compare then
10748 -- Nothing to do if special -gnatd.P debug flag set
10750 if Debug_Flag_Dot_PP then
10754 -- Ent'Length op 0/1
10756 if Is_Entity_Length (Left_Opnd (N))
10757 and then Is_Optimizable (Right_Opnd (N))
10761 -- 0/1 op Ent'Length
10763 elsif Is_Entity_Length (Right_Opnd (N))
10764 and then Is_Optimizable (Left_Opnd (N))
10766 -- Flip comparison to opposite sense
10769 when N_Op_Lt => Op := N_Op_Gt;
10770 when N_Op_Le => Op := N_Op_Ge;
10771 when N_Op_Gt => Op := N_Op_Lt;
10772 when N_Op_Ge => Op := N_Op_Le;
10773 when others => null;
10776 -- Else optimization not possible
10782 -- Fall through if we will do the optimization
10784 -- Cases to handle:
10786 -- X'Length = 0 => X'First > X'Last
10787 -- X'Length = 1 => X'First = X'Last
10788 -- X'Length = n => X'First + (n - 1) = X'Last
10790 -- X'Length /= 0 => X'First <= X'Last
10791 -- X'Length /= 1 => X'First /= X'Last
10792 -- X'Length /= n => X'First + (n - 1) /= X'Last
10794 -- X'Length >= 0 => always true, warn
10795 -- X'Length >= 1 => X'First <= X'Last
10796 -- X'Length >= n => X'First + (n - 1) <= X'Last
10798 -- X'Length > 0 => X'First <= X'Last
10799 -- X'Length > 1 => X'First < X'Last
10800 -- X'Length > n => X'First + (n - 1) < X'Last
10802 -- X'Length <= 0 => X'First > X'Last (warn, could be =)
10803 -- X'Length <= 1 => X'First >= X'Last
10804 -- X'Length <= n => X'First + (n - 1) >= X'Last
10806 -- X'Length < 0 => always false (warn)
10807 -- X'Length < 1 => X'First > X'Last
10808 -- X'Length < n => X'First + (n - 1) > X'Last
10810 -- Note: for the cases of n (not constant 0,1), we require that the
10811 -- corresponding index type be integer or shorter (i.e. not 64-bit),
10812 -- and the same for the comparison value. Then we do the comparison
10813 -- using 64-bit arithmetic (actually long long integer), so that we
10814 -- cannot have overflow intefering with the result.
10816 -- First deal with warning cases
10825 Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc)));
10826 Analyze_And_Resolve (N, Typ);
10827 Warn_On_Known_Condition (N);
10834 Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc)));
10835 Analyze_And_Resolve (N, Typ);
10836 Warn_On_Known_Condition (N);
10840 if Constant_Condition_Warnings
10841 and then Comes_From_Source (Original_Node (N))
10843 Error_Msg_N ("could replace by ""'=""?", N);
10853 -- Build the First reference we will use
10856 Make_Attribute_Reference (Loc,
10857 Prefix => New_Occurrence_Of (Ent, Loc),
10858 Attribute_Name => Name_First);
10860 if Present (Index) then
10861 Set_Expressions (Left, New_List (New_Copy (Index)));
10864 -- If general value case, then do the addition of (n - 1), and
10865 -- also add the needed conversions to type Long_Long_Integer.
10867 if Present (Comp) then
10870 Left_Opnd => Prepare_64 (Left),
10872 Make_Op_Subtract (Loc,
10873 Left_Opnd => Prepare_64 (Comp),
10874 Right_Opnd => Make_Integer_Literal (Loc, 1)));
10877 -- Build the Last reference we will use
10880 Make_Attribute_Reference (Loc,
10881 Prefix => New_Occurrence_Of (Ent, Loc),
10882 Attribute_Name => Name_Last);
10884 if Present (Index) then
10885 Set_Expressions (Right, New_List (New_Copy (Index)));
10888 -- If general operand, convert Last reference to Long_Long_Integer
10890 if Present (Comp) then
10891 Right := Prepare_64 (Right);
10894 -- Check for cases to optimize
10896 -- X'Length = 0 => X'First > X'Last
10897 -- X'Length < 1 => X'First > X'Last
10898 -- X'Length < n => X'First + (n - 1) > X'Last
10900 if (Is_Zero and then Op = N_Op_Eq)
10901 or else (not Is_Zero and then Op = N_Op_Lt)
10906 Right_Opnd => Right);
10908 -- X'Length = 1 => X'First = X'Last
10909 -- X'Length = n => X'First + (n - 1) = X'Last
10911 elsif not Is_Zero and then Op = N_Op_Eq then
10915 Right_Opnd => Right);
10917 -- X'Length /= 0 => X'First <= X'Last
10918 -- X'Length > 0 => X'First <= X'Last
10920 elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then
10924 Right_Opnd => Right);
10926 -- X'Length /= 1 => X'First /= X'Last
10927 -- X'Length /= n => X'First + (n - 1) /= X'Last
10929 elsif not Is_Zero and then Op = N_Op_Ne then
10933 Right_Opnd => Right);
10935 -- X'Length >= 1 => X'First <= X'Last
10936 -- X'Length >= n => X'First + (n - 1) <= X'Last
10938 elsif not Is_Zero and then Op = N_Op_Ge then
10942 Right_Opnd => Right);
10944 -- X'Length > 1 => X'First < X'Last
10945 -- X'Length > n => X'First + (n = 1) < X'Last
10947 elsif not Is_Zero and then Op = N_Op_Gt then
10951 Right_Opnd => Right);
10953 -- X'Length <= 1 => X'First >= X'Last
10954 -- X'Length <= n => X'First + (n - 1) >= X'Last
10956 elsif not Is_Zero and then Op = N_Op_Le then
10960 Right_Opnd => Right);
10962 -- Should not happen at this stage
10965 raise Program_Error;
10968 -- Rewrite and finish up
10970 Rewrite (N, Result);
10971 Analyze_And_Resolve (N, Typ);
10973 end Optimize_Length_Comparison;
10975 ------------------------
10976 -- Rewrite_Comparison --
10977 ------------------------
10979 procedure Rewrite_Comparison (N : Node_Id) is
10980 Warning_Generated : Boolean := False;
10981 -- Set to True if first pass with Assume_Valid generates a warning in
10982 -- which case we skip the second pass to avoid warning overloaded.
10985 -- Set to Standard_True or Standard_False
10988 if Nkind (N) = N_Type_Conversion then
10989 Rewrite_Comparison (Expression (N));
10992 elsif Nkind (N) not in N_Op_Compare then
10996 -- Now start looking at the comparison in detail. We potentially go
10997 -- through this loop twice. The first time, Assume_Valid is set False
10998 -- in the call to Compile_Time_Compare. If this call results in a
10999 -- clear result of always True or Always False, that's decisive and
11000 -- we are done. Otherwise we repeat the processing with Assume_Valid
11001 -- set to True to generate additional warnings. We can skip that step
11002 -- if Constant_Condition_Warnings is False.
11004 for AV in False .. True loop
11006 Typ : constant Entity_Id := Etype (N);
11007 Op1 : constant Node_Id := Left_Opnd (N);
11008 Op2 : constant Node_Id := Right_Opnd (N);
11010 Res : constant Compare_Result :=
11011 Compile_Time_Compare (Op1, Op2, Assume_Valid => AV);
11012 -- Res indicates if compare outcome can be compile time determined
11014 True_Result : Boolean;
11015 False_Result : Boolean;
11018 case N_Op_Compare (Nkind (N)) is
11020 True_Result := Res = EQ;
11021 False_Result := Res = LT or else Res = GT or else Res = NE;
11024 True_Result := Res in Compare_GE;
11025 False_Result := Res = LT;
11028 and then Constant_Condition_Warnings
11029 and then Comes_From_Source (Original_Node (N))
11030 and then Nkind (Original_Node (N)) = N_Op_Ge
11031 and then not In_Instance
11032 and then Is_Integer_Type (Etype (Left_Opnd (N)))
11033 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
11036 ("can never be greater than, could replace by ""'=""?", N);
11037 Warning_Generated := True;
11041 True_Result := Res = GT;
11042 False_Result := Res in Compare_LE;
11045 True_Result := Res = LT;
11046 False_Result := Res in Compare_GE;
11049 True_Result := Res in Compare_LE;
11050 False_Result := Res = GT;
11053 and then Constant_Condition_Warnings
11054 and then Comes_From_Source (Original_Node (N))
11055 and then Nkind (Original_Node (N)) = N_Op_Le
11056 and then not In_Instance
11057 and then Is_Integer_Type (Etype (Left_Opnd (N)))
11058 and then not Has_Warnings_Off (Etype (Left_Opnd (N)))
11061 ("can never be less than, could replace by ""'=""?", N);
11062 Warning_Generated := True;
11066 True_Result := Res = NE or else Res = GT or else Res = LT;
11067 False_Result := Res = EQ;
11070 -- If this is the first iteration, then we actually convert the
11071 -- comparison into True or False, if the result is certain.
11074 if True_Result or False_Result then
11075 if True_Result then
11076 Result := Standard_True;
11078 Result := Standard_False;
11083 New_Occurrence_Of (Result, Sloc (N))));
11084 Analyze_And_Resolve (N, Typ);
11085 Warn_On_Known_Condition (N);
11089 -- If this is the second iteration (AV = True), and the original
11090 -- node comes from source and we are not in an instance, then give
11091 -- a warning if we know result would be True or False. Note: we
11092 -- know Constant_Condition_Warnings is set if we get here.
11094 elsif Comes_From_Source (Original_Node (N))
11095 and then not In_Instance
11097 if True_Result then
11099 ("condition can only be False if invalid values present?",
11101 elsif False_Result then
11103 ("condition can only be True if invalid values present?",
11109 -- Skip second iteration if not warning on constant conditions or
11110 -- if the first iteration already generated a warning of some kind or
11111 -- if we are in any case assuming all values are valid (so that the
11112 -- first iteration took care of the valid case).
11114 exit when not Constant_Condition_Warnings;
11115 exit when Warning_Generated;
11116 exit when Assume_No_Invalid_Values;
11118 end Rewrite_Comparison;
11120 ----------------------------
11121 -- Safe_In_Place_Array_Op --
11122 ----------------------------
11124 function Safe_In_Place_Array_Op
11127 Op2 : Node_Id) return Boolean
11129 Target : Entity_Id;
11131 function Is_Safe_Operand (Op : Node_Id) return Boolean;
11132 -- Operand is safe if it cannot overlap part of the target of the
11133 -- operation. If the operand and the target are identical, the operand
11134 -- is safe. The operand can be empty in the case of negation.
11136 function Is_Unaliased (N : Node_Id) return Boolean;
11137 -- Check that N is a stand-alone entity
11143 function Is_Unaliased (N : Node_Id) return Boolean is
11147 and then No (Address_Clause (Entity (N)))
11148 and then No (Renamed_Object (Entity (N)));
11151 ---------------------
11152 -- Is_Safe_Operand --
11153 ---------------------
11155 function Is_Safe_Operand (Op : Node_Id) return Boolean is
11160 elsif Is_Entity_Name (Op) then
11161 return Is_Unaliased (Op);
11163 elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then
11164 return Is_Unaliased (Prefix (Op));
11166 elsif Nkind (Op) = N_Slice then
11168 Is_Unaliased (Prefix (Op))
11169 and then Entity (Prefix (Op)) /= Target;
11171 elsif Nkind (Op) = N_Op_Not then
11172 return Is_Safe_Operand (Right_Opnd (Op));
11177 end Is_Safe_Operand;
11179 -- Start of processing for Is_Safe_In_Place_Array_Op
11182 -- Skip this processing if the component size is different from system
11183 -- storage unit (since at least for NOT this would cause problems).
11185 if Component_Size (Etype (Lhs)) /= System_Storage_Unit then
11188 -- Cannot do in place stuff on VM_Target since cannot pass addresses
11190 elsif VM_Target /= No_VM then
11193 -- Cannot do in place stuff if non-standard Boolean representation
11195 elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then
11198 elsif not Is_Unaliased (Lhs) then
11202 Target := Entity (Lhs);
11203 return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2);
11205 end Safe_In_Place_Array_Op;
11207 -----------------------
11208 -- Tagged_Membership --
11209 -----------------------
11211 -- There are two different cases to consider depending on whether the right
11212 -- operand is a class-wide type or not. If not we just compare the actual
11213 -- tag of the left expr to the target type tag:
11215 -- Left_Expr.Tag = Right_Type'Tag;
11217 -- If it is a class-wide type we use the RT function CW_Membership which is
11218 -- usually implemented by looking in the ancestor tables contained in the
11219 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
11221 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
11222 -- function IW_Membership which is usually implemented by looking in the
11223 -- table of abstract interface types plus the ancestor table contained in
11224 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
11226 procedure Tagged_Membership
11228 SCIL_Node : out Node_Id;
11229 Result : out Node_Id)
11231 Left : constant Node_Id := Left_Opnd (N);
11232 Right : constant Node_Id := Right_Opnd (N);
11233 Loc : constant Source_Ptr := Sloc (N);
11235 Full_R_Typ : Entity_Id;
11236 Left_Type : Entity_Id;
11237 New_Node : Node_Id;
11238 Right_Type : Entity_Id;
11242 SCIL_Node := Empty;
11244 -- Handle entities from the limited view
11246 Left_Type := Available_View (Etype (Left));
11247 Right_Type := Available_View (Etype (Right));
11249 -- In the case where the type is an access type, the test is applied
11250 -- using the designated types (needed in Ada 2012 for implicit anonymous
11251 -- access conversions, for AI05-0149).
11253 if Is_Access_Type (Right_Type) then
11254 Left_Type := Designated_Type (Left_Type);
11255 Right_Type := Designated_Type (Right_Type);
11258 if Is_Class_Wide_Type (Left_Type) then
11259 Left_Type := Root_Type (Left_Type);
11262 if Is_Class_Wide_Type (Right_Type) then
11263 Full_R_Typ := Underlying_Type (Root_Type (Right_Type));
11265 Full_R_Typ := Underlying_Type (Right_Type);
11269 Make_Selected_Component (Loc,
11270 Prefix => Relocate_Node (Left),
11272 New_Reference_To (First_Tag_Component (Left_Type), Loc));
11274 if Is_Class_Wide_Type (Right_Type) then
11276 -- No need to issue a run-time check if we statically know that the
11277 -- result of this membership test is always true. For example,
11278 -- considering the following declarations:
11280 -- type Iface is interface;
11281 -- type T is tagged null record;
11282 -- type DT is new T and Iface with null record;
11287 -- These membership tests are always true:
11290 -- Obj2 in T'Class;
11291 -- Obj2 in Iface'Class;
11293 -- We do not need to handle cases where the membership is illegal.
11296 -- Obj1 in DT'Class; -- Compile time error
11297 -- Obj1 in Iface'Class; -- Compile time error
11299 if not Is_Class_Wide_Type (Left_Type)
11300 and then (Is_Ancestor (Etype (Right_Type), Left_Type,
11301 Use_Full_View => True)
11302 or else (Is_Interface (Etype (Right_Type))
11303 and then Interface_Present_In_Ancestor
11305 Iface => Etype (Right_Type))))
11307 Result := New_Reference_To (Standard_True, Loc);
11311 -- Ada 2005 (AI-251): Class-wide applied to interfaces
11313 if Is_Interface (Etype (Class_Wide_Type (Right_Type)))
11315 -- Support to: "Iface_CW_Typ in Typ'Class"
11317 or else Is_Interface (Left_Type)
11319 -- Issue error if IW_Membership operation not available in a
11320 -- configurable run time setting.
11322 if not RTE_Available (RE_IW_Membership) then
11324 ("dynamic membership test on interface types", N);
11330 Make_Function_Call (Loc,
11331 Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc),
11332 Parameter_Associations => New_List (
11333 Make_Attribute_Reference (Loc,
11335 Attribute_Name => Name_Address),
11337 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))),
11340 -- Ada 95: Normal case
11343 Build_CW_Membership (Loc,
11344 Obj_Tag_Node => Obj_Tag,
11347 Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc),
11349 New_Node => New_Node);
11351 -- Generate the SCIL node for this class-wide membership test.
11352 -- Done here because the previous call to Build_CW_Membership
11353 -- relocates Obj_Tag.
11355 if Generate_SCIL then
11356 SCIL_Node := Make_SCIL_Membership_Test (Sloc (N));
11357 Set_SCIL_Entity (SCIL_Node, Etype (Right_Type));
11358 Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag);
11361 Result := New_Node;
11364 -- Right_Type is not a class-wide type
11367 -- No need to check the tag of the object if Right_Typ is abstract
11369 if Is_Abstract_Type (Right_Type) then
11370 Result := New_Reference_To (Standard_False, Loc);
11375 Left_Opnd => Obj_Tag,
11378 (Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc));
11381 end Tagged_Membership;
11383 ------------------------------
11384 -- Unary_Op_Validity_Checks --
11385 ------------------------------
11387 procedure Unary_Op_Validity_Checks (N : Node_Id) is
11389 if Validity_Checks_On and Validity_Check_Operands then
11390 Ensure_Valid (Right_Opnd (N));
11392 end Unary_Op_Validity_Checks;