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 Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Itypes; use Itypes;
42 with Lib.Xref; use Lib.Xref;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
45 with Nlists; use Nlists;
47 with Output; use Output;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
52 with Sem_Aux; use Sem_Aux;
53 with Sem_Aggr; use Sem_Aggr;
54 with Sem_Attr; use Sem_Attr;
55 with Sem_Cat; use Sem_Cat;
56 with Sem_Ch4; use Sem_Ch4;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch13; use Sem_Ch13;
60 with Sem_Disp; use Sem_Disp;
61 with Sem_Dist; use Sem_Dist;
62 with Sem_Elim; use Sem_Elim;
63 with Sem_Elab; use Sem_Elab;
64 with Sem_Eval; use Sem_Eval;
65 with Sem_Intr; use Sem_Intr;
66 with Sem_Util; use Sem_Util;
67 with Sem_Type; use Sem_Type;
68 with Sem_Warn; use Sem_Warn;
69 with Sinfo; use Sinfo;
70 with Sinfo.CN; use Sinfo.CN;
71 with Snames; use Snames;
72 with Stand; use Stand;
73 with Stringt; use Stringt;
74 with Style; use Style;
75 with Tbuild; use Tbuild;
76 with Uintp; use Uintp;
77 with Urealp; use Urealp;
79 package body Sem_Res is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the type
87 -- information recursively to the descendants of N. If the node is not
88 -- overloaded, its Etype is established in the first pass. If overloaded,
89 -- the Resolve routines set the correct type. For arith. operators, the
90 -- Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 function Bad_Unordered_Enumeration_Reference
96 T : Entity_Id) return Boolean;
97 -- Node N contains a potentially dubious reference to type T, either an
98 -- explicit comparison, or an explicit range. This function returns True
99 -- if the type T is an enumeration type for which No pragma Order has been
100 -- given, and the reference N is not in the same extended source unit as
101 -- the declaration of T.
103 procedure Check_Discriminant_Use (N : Node_Id);
104 -- Enforce the restrictions on the use of discriminants when constraining
105 -- a component of a discriminated type (record or concurrent type).
107 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
108 -- Given a node for an operator associated with type T, check that
109 -- the operator is visible. Operators all of whose operands are
110 -- universal must be checked for visibility during resolution
111 -- because their type is not determinable based on their operands.
113 procedure Check_Fully_Declared_Prefix
116 -- Check that the type of the prefix of a dereference is not incomplete
118 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
119 -- Given a call node, N, which is known to occur immediately within the
120 -- subprogram being called, determines whether it is a detectable case of
121 -- an infinite recursion, and if so, outputs appropriate messages. Returns
122 -- True if an infinite recursion is detected, and False otherwise.
124 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
125 -- If the type of the object being initialized uses the secondary stack
126 -- directly or indirectly, create a transient scope for the call to the
127 -- init proc. This is because we do not create transient scopes for the
128 -- initialization of individual components within the init proc itself.
129 -- Could be optimized away perhaps?
131 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
132 -- N is the node for a logical operator. If the operator is predefined, and
133 -- the root type of the operands is Standard.Boolean, then a check is made
134 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
135 -- the style check for Style_Check_Boolean_And_Or.
137 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
138 -- Determine whether E is an access type declared by an access declaration,
139 -- and not an (anonymous) allocator type.
141 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
142 -- Utility to check whether the entity for an operator is a predefined
143 -- operator, in which case the expression is left as an operator in the
144 -- tree (else it is rewritten into a call). An instance of an intrinsic
145 -- conversion operation may be given an operator name, but is not treated
146 -- like an operator. Note that an operator that is an imported back-end
147 -- builtin has convention Intrinsic, but is expected to be rewritten into
148 -- a call, so such an operator is not treated as predefined by this
151 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
152 -- If a default expression in entry call N depends on the discriminants
153 -- of the task, it must be replaced with a reference to the discriminant
154 -- of the task being called.
156 procedure Resolve_Op_Concat_Arg
161 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
162 -- concatenation operator. The operand is either of the array type or of
163 -- the component type. If the operand is an aggregate, and the component
164 -- type is composite, this is ambiguous if component type has aggregates.
166 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
167 -- Does the first part of the work of Resolve_Op_Concat
169 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
170 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
171 -- has been resolved. See Resolve_Op_Concat for details.
173 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
209 function Operator_Kind
211 Is_Binary : Boolean) return Node_Kind;
212 -- Utility to map the name of an operator into the corresponding Node. Used
213 -- by other node rewriting procedures.
215 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
216 -- Resolve actuals of call, and add default expressions for missing ones.
217 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
218 -- called subprogram.
220 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
221 -- Called from Resolve_Call, when the prefix denotes an entry or element
222 -- of entry family. Actuals are resolved as for subprograms, and the node
223 -- is rebuilt as an entry call. Also called for protected operations. Typ
224 -- is the context type, which is used when the operation is a protected
225 -- function with no arguments, and the return value is indexed.
227 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
228 -- A call to a user-defined intrinsic operator is rewritten as a call to
229 -- the corresponding predefined operator, with suitable conversions. Note
230 -- that this applies only for intrinsic operators that denote predefined
231 -- operators, not ones that are intrinsic imports of back-end builtins.
233 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
234 -- Ditto, for unary operators (arithmetic ones and "not" on signed
235 -- integer types for VMS).
237 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
238 -- If an operator node resolves to a call to a user-defined operator,
239 -- rewrite the node as a function call.
241 procedure Make_Call_Into_Operator
245 -- Inverse transformation: if an operator is given in functional notation,
246 -- then after resolving the node, transform into an operator node, so
247 -- that operands are resolved properly. Recall that predefined operators
248 -- do not have a full signature and special resolution rules apply.
250 procedure Rewrite_Renamed_Operator
254 -- An operator can rename another, e.g. in an instantiation. In that
255 -- case, the proper operator node must be constructed and resolved.
257 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
258 -- The String_Literal_Subtype is built for all strings that are not
259 -- operands of a static concatenation operation. If the argument is
260 -- not a N_String_Literal node, then the call has no effect.
262 procedure Set_Slice_Subtype (N : Node_Id);
263 -- Build subtype of array type, with the range specified by the slice
265 procedure Simplify_Type_Conversion (N : Node_Id);
266 -- Called after N has been resolved and evaluated, but before range checks
267 -- have been applied. Currently simplifies a combination of floating-point
268 -- to integer conversion and Truncation attribute.
270 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
271 -- A universal_fixed expression in an universal context is unambiguous if
272 -- there is only one applicable fixed point type. Determining whether there
273 -- is only one requires a search over all visible entities, and happens
274 -- only in very pathological cases (see 6115-006).
276 -------------------------
277 -- Ambiguous_Character --
278 -------------------------
280 procedure Ambiguous_Character (C : Node_Id) is
284 if Nkind (C) = N_Character_Literal then
285 Error_Msg_N ("ambiguous character literal", C);
287 -- First the ones in Standard
289 Error_Msg_N ("\\possible interpretation: Character!", C);
290 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
292 -- Include Wide_Wide_Character in Ada 2005 mode
294 if Ada_Version >= Ada_2005 then
295 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
298 -- Now any other types that match
300 E := Current_Entity (C);
301 while Present (E) loop
302 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
306 end Ambiguous_Character;
308 -------------------------
309 -- Analyze_And_Resolve --
310 -------------------------
312 procedure Analyze_And_Resolve (N : Node_Id) is
316 end Analyze_And_Resolve;
318 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
322 end Analyze_And_Resolve;
324 -- Version withs check(s) suppressed
326 procedure Analyze_And_Resolve
331 Scop : constant Entity_Id := Current_Scope;
334 if Suppress = All_Checks then
336 Svg : constant Suppress_Array := Scope_Suppress;
338 Scope_Suppress := (others => True);
339 Analyze_And_Resolve (N, Typ);
340 Scope_Suppress := Svg;
345 Svg : constant Boolean := Scope_Suppress (Suppress);
348 Scope_Suppress (Suppress) := True;
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress (Suppress) := Svg;
354 if Current_Scope /= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
366 end Analyze_And_Resolve;
368 procedure Analyze_And_Resolve
372 Scop : constant Entity_Id := Current_Scope;
375 if Suppress = All_Checks then
377 Svg : constant Suppress_Array := Scope_Suppress;
379 Scope_Suppress := (others => True);
380 Analyze_And_Resolve (N);
381 Scope_Suppress := Svg;
386 Svg : constant Boolean := Scope_Suppress (Suppress);
389 Scope_Suppress (Suppress) := True;
390 Analyze_And_Resolve (N);
391 Scope_Suppress (Suppress) := Svg;
395 if Current_Scope /= Scop
396 and then Scope_Is_Transient
398 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
401 end Analyze_And_Resolve;
403 ----------------------------------------
404 -- Bad_Unordered_Enumeration_Reference --
405 ----------------------------------------
407 function Bad_Unordered_Enumeration_Reference
409 T : Entity_Id) return Boolean
412 return Is_Enumeration_Type (T)
413 and then Comes_From_Source (N)
414 and then Warn_On_Unordered_Enumeration_Type
415 and then not Has_Pragma_Ordered (T)
416 and then not In_Same_Extended_Unit (N, T);
417 end Bad_Unordered_Enumeration_Reference;
419 ----------------------------
420 -- Check_Discriminant_Use --
421 ----------------------------
423 procedure Check_Discriminant_Use (N : Node_Id) is
424 PN : constant Node_Id := Parent (N);
425 Disc : constant Entity_Id := Entity (N);
430 -- Any use in a spec-expression is legal
432 if In_Spec_Expression then
435 elsif Nkind (PN) = N_Range then
437 -- Discriminant cannot be used to constrain a scalar type
441 if Nkind (P) = N_Range_Constraint
442 and then Nkind (Parent (P)) = N_Subtype_Indication
443 and then Nkind (Parent (Parent (P))) = N_Component_Definition
445 Error_Msg_N ("discriminant cannot constrain scalar type", N);
447 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
449 -- The following check catches the unusual case where a
450 -- discriminant appears within an index constraint that is part of
451 -- a larger expression within a constraint on a component, e.g. "C
452 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
453 -- of record components, and note that a similar check should also
454 -- apply in the case of discriminant constraints below. ???
456 -- Note that the check for N_Subtype_Declaration below is to
457 -- detect the valid use of discriminants in the constraints of a
458 -- subtype declaration when this subtype declaration appears
459 -- inside the scope of a record type (which is syntactically
460 -- illegal, but which may be created as part of derived type
461 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
464 if Ekind (Current_Scope) = E_Record_Type
465 and then Scope (Disc) = Current_Scope
467 (Nkind (Parent (P)) = N_Subtype_Indication
469 Nkind_In (Parent (Parent (P)), N_Component_Definition,
470 N_Subtype_Declaration)
471 and then Paren_Count (N) = 0)
474 ("discriminant must appear alone in component constraint", N);
478 -- Detect a common error:
480 -- type R (D : Positive := 100) is record
481 -- Name : String (1 .. D);
484 -- The default value causes an object of type R to be allocated
485 -- with room for Positive'Last characters. The RM does not mandate
486 -- the allocation of the maximum size, but that is what GNAT does
487 -- so we should warn the programmer that there is a problem.
489 Check_Large : declare
495 function Large_Storage_Type (T : Entity_Id) return Boolean;
496 -- Return True if type T has a large enough range that any
497 -- array whose index type covered the whole range of the type
498 -- would likely raise Storage_Error.
500 ------------------------
501 -- Large_Storage_Type --
502 ------------------------
504 function Large_Storage_Type (T : Entity_Id) return Boolean is
506 -- The type is considered large if its bounds are known at
507 -- compile time and if it requires at least as many bits as
508 -- a Positive to store the possible values.
510 return Compile_Time_Known_Value (Type_Low_Bound (T))
511 and then Compile_Time_Known_Value (Type_High_Bound (T))
513 Minimum_Size (T, Biased => True) >=
514 RM_Size (Standard_Positive);
515 end Large_Storage_Type;
517 -- Start of processing for Check_Large
520 -- Check that the Disc has a large range
522 if not Large_Storage_Type (Etype (Disc)) then
526 -- If the enclosing type is limited, we allocate only the
527 -- default value, not the maximum, and there is no need for
530 if Is_Limited_Type (Scope (Disc)) then
534 -- Check that it is the high bound
536 if N /= High_Bound (PN)
537 or else No (Discriminant_Default_Value (Disc))
542 -- Check the array allows a large range at this bound. First
547 if Nkind (SI) /= N_Subtype_Indication then
551 T := Entity (Subtype_Mark (SI));
553 if not Is_Array_Type (T) then
557 -- Next, find the dimension
559 TB := First_Index (T);
560 CB := First (Constraints (P));
562 and then Present (TB)
563 and then Present (CB)
574 -- Now, check the dimension has a large range
576 if not Large_Storage_Type (Etype (TB)) then
580 -- Warn about the danger
583 ("?creation of & object may raise Storage_Error!",
592 -- Legal case is in index or discriminant constraint
594 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
595 N_Discriminant_Association)
597 if Paren_Count (N) > 0 then
599 ("discriminant in constraint must appear alone", N);
601 elsif Nkind (N) = N_Expanded_Name
602 and then Comes_From_Source (N)
605 ("discriminant must appear alone as a direct name", N);
610 -- Otherwise, context is an expression. It should not be within (i.e. a
611 -- subexpression of) a constraint for a component.
616 while not Nkind_In (P, N_Component_Declaration,
617 N_Subtype_Indication,
625 -- If the discriminant is used in an expression that is a bound of a
626 -- scalar type, an Itype is created and the bounds are attached to
627 -- its range, not to the original subtype indication. Such use is of
628 -- course a double fault.
630 if (Nkind (P) = N_Subtype_Indication
631 and then Nkind_In (Parent (P), N_Component_Definition,
632 N_Derived_Type_Definition)
633 and then D = Constraint (P))
635 -- The constraint itself may be given by a subtype indication,
636 -- rather than by a more common discrete range.
638 or else (Nkind (P) = N_Subtype_Indication
640 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
641 or else Nkind (P) = N_Entry_Declaration
642 or else Nkind (D) = N_Defining_Identifier
645 ("discriminant in constraint must appear alone", N);
648 end Check_Discriminant_Use;
650 --------------------------------
651 -- Check_For_Visible_Operator --
652 --------------------------------
654 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
656 if Is_Invisible_Operator (N, T) then
657 Error_Msg_NE -- CODEFIX
658 ("operator for} is not directly visible!", N, First_Subtype (T));
659 Error_Msg_N -- CODEFIX
660 ("use clause would make operation legal!", N);
662 end Check_For_Visible_Operator;
664 ----------------------------------
665 -- Check_Fully_Declared_Prefix --
666 ----------------------------------
668 procedure Check_Fully_Declared_Prefix
673 -- Check that the designated type of the prefix of a dereference is
674 -- not an incomplete type. This cannot be done unconditionally, because
675 -- dereferences of private types are legal in default expressions. This
676 -- case is taken care of in Check_Fully_Declared, called below. There
677 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
679 -- This consideration also applies to similar checks for allocators,
680 -- qualified expressions, and type conversions.
682 -- An additional exception concerns other per-object expressions that
683 -- are not directly related to component declarations, in particular
684 -- representation pragmas for tasks. These will be per-object
685 -- expressions if they depend on discriminants or some global entity.
686 -- If the task has access discriminants, the designated type may be
687 -- incomplete at the point the expression is resolved. This resolution
688 -- takes place within the body of the initialization procedure, where
689 -- the discriminant is replaced by its discriminal.
691 if Is_Entity_Name (Pref)
692 and then Ekind (Entity (Pref)) = E_In_Parameter
696 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
697 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
698 -- Analyze_Object_Renaming, and Freeze_Entity.
700 elsif Ada_Version >= Ada_2005
701 and then Is_Entity_Name (Pref)
702 and then Is_Access_Type (Etype (Pref))
703 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
705 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
709 Check_Fully_Declared (Typ, Parent (Pref));
711 end Check_Fully_Declared_Prefix;
713 ------------------------------
714 -- Check_Infinite_Recursion --
715 ------------------------------
717 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
721 function Same_Argument_List return Boolean;
722 -- Check whether list of actuals is identical to list of formals of
723 -- called function (which is also the enclosing scope).
725 ------------------------
726 -- Same_Argument_List --
727 ------------------------
729 function Same_Argument_List return Boolean is
735 if not Is_Entity_Name (Name (N)) then
738 Subp := Entity (Name (N));
741 F := First_Formal (Subp);
742 A := First_Actual (N);
743 while Present (F) and then Present (A) loop
744 if not Is_Entity_Name (A)
745 or else Entity (A) /= F
755 end Same_Argument_List;
757 -- Start of processing for Check_Infinite_Recursion
760 -- Special case, if this is a procedure call and is a call to the
761 -- current procedure with the same argument list, then this is for
762 -- sure an infinite recursion and we insert a call to raise SE.
764 if Is_List_Member (N)
765 and then List_Length (List_Containing (N)) = 1
766 and then Same_Argument_List
769 P : constant Node_Id := Parent (N);
771 if Nkind (P) = N_Handled_Sequence_Of_Statements
772 and then Nkind (Parent (P)) = N_Subprogram_Body
773 and then Is_Empty_List (Declarations (Parent (P)))
775 Error_Msg_N ("!?infinite recursion", N);
776 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
778 Make_Raise_Storage_Error (Sloc (N),
779 Reason => SE_Infinite_Recursion));
785 -- If not that special case, search up tree, quitting if we reach a
786 -- construct (e.g. a conditional) that tells us that this is not a
787 -- case for an infinite recursion warning.
793 -- If no parent, then we were not inside a subprogram, this can for
794 -- example happen when processing certain pragmas in a spec. Just
795 -- return False in this case.
801 -- Done if we get to subprogram body, this is definitely an infinite
802 -- recursion case if we did not find anything to stop us.
804 exit when Nkind (P) = N_Subprogram_Body;
806 -- If appearing in conditional, result is false
808 if Nkind_In (P, N_Or_Else,
812 N_Conditional_Expression,
817 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
818 and then C /= First (Statements (P))
820 -- If the call is the expression of a return statement and the
821 -- actuals are identical to the formals, it's worth a warning.
822 -- However, we skip this if there is an immediately preceding
823 -- raise statement, since the call is never executed.
825 -- Furthermore, this corresponds to a common idiom:
827 -- function F (L : Thing) return Boolean is
829 -- raise Program_Error;
833 -- for generating a stub function
835 if Nkind (Parent (N)) = N_Simple_Return_Statement
836 and then Same_Argument_List
838 exit when not Is_List_Member (Parent (N));
840 -- OK, return statement is in a statement list, look for raise
846 -- Skip past N_Freeze_Entity nodes generated by expansion
848 Nod := Prev (Parent (N));
850 and then Nkind (Nod) = N_Freeze_Entity
855 -- If no raise statement, give warning
857 exit when Nkind (Nod) /= N_Raise_Statement
859 (Nkind (Nod) not in N_Raise_xxx_Error
860 or else Present (Condition (Nod)));
871 Error_Msg_N ("!?possible infinite recursion", N);
872 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
875 end Check_Infinite_Recursion;
877 -------------------------------
878 -- Check_Initialization_Call --
879 -------------------------------
881 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
882 Typ : constant Entity_Id := Etype (First_Formal (Nam));
884 function Uses_SS (T : Entity_Id) return Boolean;
885 -- Check whether the creation of an object of the type will involve
886 -- use of the secondary stack. If T is a record type, this is true
887 -- if the expression for some component uses the secondary stack, e.g.
888 -- through a call to a function that returns an unconstrained value.
889 -- False if T is controlled, because cleanups occur elsewhere.
895 function Uses_SS (T : Entity_Id) return Boolean is
898 Full_Type : Entity_Id := Underlying_Type (T);
901 -- Normally we want to use the underlying type, but if it's not set
902 -- then continue with T.
904 if not Present (Full_Type) then
908 if Is_Controlled (Full_Type) then
911 elsif Is_Array_Type (Full_Type) then
912 return Uses_SS (Component_Type (Full_Type));
914 elsif Is_Record_Type (Full_Type) then
915 Comp := First_Component (Full_Type);
916 while Present (Comp) loop
917 if Ekind (Comp) = E_Component
918 and then Nkind (Parent (Comp)) = N_Component_Declaration
920 -- The expression for a dynamic component may be rewritten
921 -- as a dereference, so retrieve original node.
923 Expr := Original_Node (Expression (Parent (Comp)));
925 -- Return True if the expression is a call to a function
926 -- (including an attribute function such as Image, or a
927 -- user-defined operator) with a result that requires a
930 if (Nkind (Expr) = N_Function_Call
931 or else Nkind (Expr) in N_Op
932 or else (Nkind (Expr) = N_Attribute_Reference
933 and then Present (Expressions (Expr))))
934 and then Requires_Transient_Scope (Etype (Expr))
938 elsif Uses_SS (Etype (Comp)) then
943 Next_Component (Comp);
953 -- Start of processing for Check_Initialization_Call
956 -- Establish a transient scope if the type needs it
958 if Uses_SS (Typ) then
959 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
961 end Check_Initialization_Call;
963 ---------------------------------------
964 -- Check_No_Direct_Boolean_Operators --
965 ---------------------------------------
967 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
969 if Scope (Entity (N)) = Standard_Standard
970 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
972 -- Restriction only applies to original source code
974 if Comes_From_Source (N) then
975 Check_Restriction (No_Direct_Boolean_Operators, N);
980 Check_Boolean_Operator (N);
982 end Check_No_Direct_Boolean_Operators;
984 ------------------------------
985 -- Check_Parameterless_Call --
986 ------------------------------
988 procedure Check_Parameterless_Call (N : Node_Id) is
991 function Prefix_Is_Access_Subp return Boolean;
992 -- If the prefix is of an access_to_subprogram type, the node must be
993 -- rewritten as a call. Ditto if the prefix is overloaded and all its
994 -- interpretations are access to subprograms.
996 ---------------------------
997 -- Prefix_Is_Access_Subp --
998 ---------------------------
1000 function Prefix_Is_Access_Subp return Boolean is
1005 -- If the context is an attribute reference that can apply to
1006 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1008 if Nkind (Parent (N)) = N_Attribute_Reference
1009 and then (Attribute_Name (Parent (N)) = Name_Address or else
1010 Attribute_Name (Parent (N)) = Name_Code_Address or else
1011 Attribute_Name (Parent (N)) = Name_Access)
1016 if not Is_Overloaded (N) then
1018 Ekind (Etype (N)) = E_Subprogram_Type
1019 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1021 Get_First_Interp (N, I, It);
1022 while Present (It.Typ) loop
1023 if Ekind (It.Typ) /= E_Subprogram_Type
1024 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1029 Get_Next_Interp (I, It);
1034 end Prefix_Is_Access_Subp;
1036 -- Start of processing for Check_Parameterless_Call
1039 -- Defend against junk stuff if errors already detected
1041 if Total_Errors_Detected /= 0 then
1042 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1044 elsif Nkind (N) in N_Has_Chars
1045 and then Chars (N) in Error_Name_Or_No_Name
1053 -- If the context expects a value, and the name is a procedure, this is
1054 -- most likely a missing 'Access. Don't try to resolve the parameterless
1055 -- call, error will be caught when the outer call is analyzed.
1057 if Is_Entity_Name (N)
1058 and then Ekind (Entity (N)) = E_Procedure
1059 and then not Is_Overloaded (N)
1061 Nkind_In (Parent (N), N_Parameter_Association,
1063 N_Procedure_Call_Statement)
1068 -- Rewrite as call if overloadable entity that is (or could be, in the
1069 -- overloaded case) a function call. If we know for sure that the entity
1070 -- is an enumeration literal, we do not rewrite it.
1072 -- If the entity is the name of an operator, it cannot be a call because
1073 -- operators cannot have default parameters. In this case, this must be
1074 -- a string whose contents coincide with an operator name. Set the kind
1075 -- of the node appropriately.
1077 if (Is_Entity_Name (N)
1078 and then Nkind (N) /= N_Operator_Symbol
1079 and then Is_Overloadable (Entity (N))
1080 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1081 or else Is_Overloaded (N)))
1083 -- Rewrite as call if it is an explicit dereference of an expression of
1084 -- a subprogram access type, and the subprogram type is not that of a
1085 -- procedure or entry.
1088 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1090 -- Rewrite as call if it is a selected component which is a function,
1091 -- this is the case of a call to a protected function (which may be
1092 -- overloaded with other protected operations).
1095 (Nkind (N) = N_Selected_Component
1096 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1098 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1100 and then Is_Overloaded (Selector_Name (N)))))
1102 -- If one of the above three conditions is met, rewrite as call. Apply
1103 -- the rewriting only once.
1106 if Nkind (Parent (N)) /= N_Function_Call
1107 or else N /= Name (Parent (N))
1110 -- This may be a prefixed call that was not fully analyzed, e.g.
1111 -- an actual in an instance.
1113 if Ada_Version >= Ada_2005
1114 and then Nkind (N) = N_Selected_Component
1115 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1117 Analyze_Selected_Component (N);
1119 if Nkind (N) /= N_Selected_Component then
1124 Nam := New_Copy (N);
1126 -- If overloaded, overload set belongs to new copy
1128 Save_Interps (N, Nam);
1130 -- Change node to parameterless function call (note that the
1131 -- Parameter_Associations associations field is left set to Empty,
1132 -- its normal default value since there are no parameters)
1134 Change_Node (N, N_Function_Call);
1136 Set_Sloc (N, Sloc (Nam));
1140 elsif Nkind (N) = N_Parameter_Association then
1141 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1143 elsif Nkind (N) = N_Operator_Symbol then
1144 Change_Operator_Symbol_To_String_Literal (N);
1145 Set_Is_Overloaded (N, False);
1146 Set_Etype (N, Any_String);
1148 end Check_Parameterless_Call;
1150 -----------------------------
1151 -- Is_Definite_Access_Type --
1152 -----------------------------
1154 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1155 Btyp : constant Entity_Id := Base_Type (E);
1157 return Ekind (Btyp) = E_Access_Type
1158 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1159 and then Comes_From_Source (Btyp));
1160 end Is_Definite_Access_Type;
1162 ----------------------
1163 -- Is_Predefined_Op --
1164 ----------------------
1166 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1168 -- Predefined operators are intrinsic subprograms
1170 if not Is_Intrinsic_Subprogram (Nam) then
1174 -- A call to a back-end builtin is never a predefined operator
1176 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1180 return not Is_Generic_Instance (Nam)
1181 and then Chars (Nam) in Any_Operator_Name
1182 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1183 end Is_Predefined_Op;
1185 -----------------------------
1186 -- Make_Call_Into_Operator --
1187 -----------------------------
1189 procedure Make_Call_Into_Operator
1194 Op_Name : constant Name_Id := Chars (Op_Id);
1195 Act1 : Node_Id := First_Actual (N);
1196 Act2 : Node_Id := Next_Actual (Act1);
1197 Error : Boolean := False;
1198 Func : constant Entity_Id := Entity (Name (N));
1199 Is_Binary : constant Boolean := Present (Act2);
1201 Opnd_Type : Entity_Id;
1202 Orig_Type : Entity_Id := Empty;
1205 type Kind_Test is access function (E : Entity_Id) return Boolean;
1207 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1208 -- If the operand is not universal, and the operator is given by an
1209 -- expanded name, verify that the operand has an interpretation with a
1210 -- type defined in the given scope of the operator.
1212 function Type_In_P (Test : Kind_Test) return Entity_Id;
1213 -- Find a type of the given class in package Pack that contains the
1216 ---------------------------
1217 -- Operand_Type_In_Scope --
1218 ---------------------------
1220 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1221 Nod : constant Node_Id := Right_Opnd (Op_Node);
1226 if not Is_Overloaded (Nod) then
1227 return Scope (Base_Type (Etype (Nod))) = S;
1230 Get_First_Interp (Nod, I, It);
1231 while Present (It.Typ) loop
1232 if Scope (Base_Type (It.Typ)) = S then
1236 Get_Next_Interp (I, It);
1241 end Operand_Type_In_Scope;
1247 function Type_In_P (Test : Kind_Test) return Entity_Id is
1250 function In_Decl return Boolean;
1251 -- Verify that node is not part of the type declaration for the
1252 -- candidate type, which would otherwise be invisible.
1258 function In_Decl return Boolean is
1259 Decl_Node : constant Node_Id := Parent (E);
1265 if Etype (E) = Any_Type then
1268 elsif No (Decl_Node) then
1273 and then Nkind (N2) /= N_Compilation_Unit
1275 if N2 = Decl_Node then
1286 -- Start of processing for Type_In_P
1289 -- If the context type is declared in the prefix package, this is the
1290 -- desired base type.
1292 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1293 return Base_Type (Typ);
1296 E := First_Entity (Pack);
1297 while Present (E) loop
1299 and then not In_Decl
1311 -- Start of processing for Make_Call_Into_Operator
1314 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1319 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1320 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1321 Save_Interps (Act1, Left_Opnd (Op_Node));
1322 Save_Interps (Act2, Right_Opnd (Op_Node));
1323 Act1 := Left_Opnd (Op_Node);
1324 Act2 := Right_Opnd (Op_Node);
1329 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1330 Save_Interps (Act1, Right_Opnd (Op_Node));
1331 Act1 := Right_Opnd (Op_Node);
1334 -- If the operator is denoted by an expanded name, and the prefix is
1335 -- not Standard, but the operator is a predefined one whose scope is
1336 -- Standard, then this is an implicit_operator, inserted as an
1337 -- interpretation by the procedure of the same name. This procedure
1338 -- overestimates the presence of implicit operators, because it does
1339 -- not examine the type of the operands. Verify now that the operand
1340 -- type appears in the given scope. If right operand is universal,
1341 -- check the other operand. In the case of concatenation, either
1342 -- argument can be the component type, so check the type of the result.
1343 -- If both arguments are literals, look for a type of the right kind
1344 -- defined in the given scope. This elaborate nonsense is brought to
1345 -- you courtesy of b33302a. The type itself must be frozen, so we must
1346 -- find the type of the proper class in the given scope.
1348 -- A final wrinkle is the multiplication operator for fixed point types,
1349 -- which is defined in Standard only, and not in the scope of the
1350 -- fixed point type itself.
1352 if Nkind (Name (N)) = N_Expanded_Name then
1353 Pack := Entity (Prefix (Name (N)));
1355 -- If the entity being called is defined in the given package, it is
1356 -- a renaming of a predefined operator, and known to be legal.
1358 if Scope (Entity (Name (N))) = Pack
1359 and then Pack /= Standard_Standard
1363 -- Visibility does not need to be checked in an instance: if the
1364 -- operator was not visible in the generic it has been diagnosed
1365 -- already, else there is an implicit copy of it in the instance.
1367 elsif In_Instance then
1370 elsif (Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide)
1371 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1372 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1374 if Pack /= Standard_Standard then
1378 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1381 elsif Ada_Version >= Ada_2005
1382 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1383 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1388 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1390 if Op_Name = Name_Op_Concat then
1391 Opnd_Type := Base_Type (Typ);
1393 elsif (Scope (Opnd_Type) = Standard_Standard
1395 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1397 and then not Comes_From_Source (Opnd_Type))
1399 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1402 if Scope (Opnd_Type) = Standard_Standard then
1404 -- Verify that the scope contains a type that corresponds to
1405 -- the given literal. Optimize the case where Pack is Standard.
1407 if Pack /= Standard_Standard then
1409 if Opnd_Type = Universal_Integer then
1410 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1412 elsif Opnd_Type = Universal_Real then
1413 Orig_Type := Type_In_P (Is_Real_Type'Access);
1415 elsif Opnd_Type = Any_String then
1416 Orig_Type := Type_In_P (Is_String_Type'Access);
1418 elsif Opnd_Type = Any_Access then
1419 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1421 elsif Opnd_Type = Any_Composite then
1422 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1424 if Present (Orig_Type) then
1425 if Has_Private_Component (Orig_Type) then
1428 Set_Etype (Act1, Orig_Type);
1431 Set_Etype (Act2, Orig_Type);
1440 Error := No (Orig_Type);
1443 elsif Ekind (Opnd_Type) = E_Allocator_Type
1444 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1448 -- If the type is defined elsewhere, and the operator is not
1449 -- defined in the given scope (by a renaming declaration, e.g.)
1450 -- then this is an error as well. If an extension of System is
1451 -- present, and the type may be defined there, Pack must be
1454 elsif Scope (Opnd_Type) /= Pack
1455 and then Scope (Op_Id) /= Pack
1456 and then (No (System_Aux_Id)
1457 or else Scope (Opnd_Type) /= System_Aux_Id
1458 or else Pack /= Scope (System_Aux_Id))
1460 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1463 Error := not Operand_Type_In_Scope (Pack);
1466 elsif Pack = Standard_Standard
1467 and then not Operand_Type_In_Scope (Standard_Standard)
1474 Error_Msg_Node_2 := Pack;
1476 ("& not declared in&", N, Selector_Name (Name (N)));
1477 Set_Etype (N, Any_Type);
1480 -- Detect a mismatch between the context type and the result type
1481 -- in the named package, which is otherwise not detected if the
1482 -- operands are universal. Check is only needed if source entity is
1483 -- an operator, not a function that renames an operator.
1485 elsif Nkind (Parent (N)) /= N_Type_Conversion
1486 and then Ekind (Entity (Name (N))) = E_Operator
1487 and then Is_Numeric_Type (Typ)
1488 and then not Is_Universal_Numeric_Type (Typ)
1489 and then Scope (Base_Type (Typ)) /= Pack
1490 and then not In_Instance
1492 if Is_Fixed_Point_Type (Typ)
1493 and then (Op_Name = Name_Op_Multiply
1495 Op_Name = Name_Op_Divide)
1497 -- Already checked above
1501 -- Operator may be defined in an extension of System
1503 elsif Present (System_Aux_Id)
1504 and then Scope (Opnd_Type) = System_Aux_Id
1509 -- Could we use Wrong_Type here??? (this would require setting
1510 -- Etype (N) to the actual type found where Typ was expected).
1512 Error_Msg_NE ("expect }", N, Typ);
1517 Set_Chars (Op_Node, Op_Name);
1519 if not Is_Private_Type (Etype (N)) then
1520 Set_Etype (Op_Node, Base_Type (Etype (N)));
1522 Set_Etype (Op_Node, Etype (N));
1525 -- If this is a call to a function that renames a predefined equality,
1526 -- the renaming declaration provides a type that must be used to
1527 -- resolve the operands. This must be done now because resolution of
1528 -- the equality node will not resolve any remaining ambiguity, and it
1529 -- assumes that the first operand is not overloaded.
1531 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1532 and then Ekind (Func) = E_Function
1533 and then Is_Overloaded (Act1)
1535 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1536 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1539 Set_Entity (Op_Node, Op_Id);
1540 Generate_Reference (Op_Id, N, ' ');
1542 -- Do rewrite setting Comes_From_Source on the result if the original
1543 -- call came from source. Although it is not strictly the case that the
1544 -- operator as such comes from the source, logically it corresponds
1545 -- exactly to the function call in the source, so it should be marked
1546 -- this way (e.g. to make sure that validity checks work fine).
1549 CS : constant Boolean := Comes_From_Source (N);
1551 Rewrite (N, Op_Node);
1552 Set_Comes_From_Source (N, CS);
1555 -- If this is an arithmetic operator and the result type is private,
1556 -- the operands and the result must be wrapped in conversion to
1557 -- expose the underlying numeric type and expand the proper checks,
1558 -- e.g. on division.
1560 if Is_Private_Type (Typ) then
1562 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1563 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1564 Resolve_Intrinsic_Operator (N, Typ);
1566 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1567 Resolve_Intrinsic_Unary_Operator (N, Typ);
1575 end Make_Call_Into_Operator;
1581 function Operator_Kind
1583 Is_Binary : Boolean) return Node_Kind
1588 -- Use CASE statement or array???
1591 if Op_Name = Name_Op_And then
1593 elsif Op_Name = Name_Op_Or then
1595 elsif Op_Name = Name_Op_Xor then
1597 elsif Op_Name = Name_Op_Eq then
1599 elsif Op_Name = Name_Op_Ne then
1601 elsif Op_Name = Name_Op_Lt then
1603 elsif Op_Name = Name_Op_Le then
1605 elsif Op_Name = Name_Op_Gt then
1607 elsif Op_Name = Name_Op_Ge then
1609 elsif Op_Name = Name_Op_Add then
1611 elsif Op_Name = Name_Op_Subtract then
1612 Kind := N_Op_Subtract;
1613 elsif Op_Name = Name_Op_Concat then
1614 Kind := N_Op_Concat;
1615 elsif Op_Name = Name_Op_Multiply then
1616 Kind := N_Op_Multiply;
1617 elsif Op_Name = Name_Op_Divide then
1618 Kind := N_Op_Divide;
1619 elsif Op_Name = Name_Op_Mod then
1621 elsif Op_Name = Name_Op_Rem then
1623 elsif Op_Name = Name_Op_Expon then
1626 raise Program_Error;
1632 if Op_Name = Name_Op_Add then
1634 elsif Op_Name = Name_Op_Subtract then
1636 elsif Op_Name = Name_Op_Abs then
1638 elsif Op_Name = Name_Op_Not then
1641 raise Program_Error;
1648 ----------------------------
1649 -- Preanalyze_And_Resolve --
1650 ----------------------------
1652 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1653 Save_Full_Analysis : constant Boolean := Full_Analysis;
1656 Full_Analysis := False;
1657 Expander_Mode_Save_And_Set (False);
1659 -- We suppress all checks for this analysis, since the checks will
1660 -- be applied properly, and in the right location, when the default
1661 -- expression is reanalyzed and reexpanded later on.
1663 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1665 Expander_Mode_Restore;
1666 Full_Analysis := Save_Full_Analysis;
1667 end Preanalyze_And_Resolve;
1669 -- Version without context type
1671 procedure Preanalyze_And_Resolve (N : Node_Id) is
1672 Save_Full_Analysis : constant Boolean := Full_Analysis;
1675 Full_Analysis := False;
1676 Expander_Mode_Save_And_Set (False);
1679 Resolve (N, Etype (N), Suppress => All_Checks);
1681 Expander_Mode_Restore;
1682 Full_Analysis := Save_Full_Analysis;
1683 end Preanalyze_And_Resolve;
1685 ----------------------------------
1686 -- Replace_Actual_Discriminants --
1687 ----------------------------------
1689 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1690 Loc : constant Source_Ptr := Sloc (N);
1691 Tsk : Node_Id := Empty;
1693 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1694 -- Comment needed???
1700 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1704 if Nkind (Nod) = N_Identifier then
1705 Ent := Entity (Nod);
1708 and then Ekind (Ent) = E_Discriminant
1711 Make_Selected_Component (Loc,
1712 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1713 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1715 Set_Etype (Nod, Etype (Ent));
1723 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1725 -- Start of processing for Replace_Actual_Discriminants
1728 if not Full_Expander_Active then
1732 if Nkind (Name (N)) = N_Selected_Component then
1733 Tsk := Prefix (Name (N));
1735 elsif Nkind (Name (N)) = N_Indexed_Component then
1736 Tsk := Prefix (Prefix (Name (N)));
1742 Replace_Discrs (Default);
1744 end Replace_Actual_Discriminants;
1750 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1751 Ambiguous : Boolean := False;
1752 Ctx_Type : Entity_Id := Typ;
1753 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1754 Err_Type : Entity_Id := Empty;
1755 Found : Boolean := False;
1758 I1 : Interp_Index := 0; -- prevent junk warning
1761 Seen : Entity_Id := Empty; -- prevent junk warning
1763 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1764 -- Determine whether a node comes from a predefined library unit or
1767 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1768 -- Try and fix up a literal so that it matches its expected type. New
1769 -- literals are manufactured if necessary to avoid cascaded errors.
1771 procedure Report_Ambiguous_Argument;
1772 -- Additional diagnostics when an ambiguous call has an ambiguous
1773 -- argument (typically a controlling actual).
1775 procedure Resolution_Failed;
1776 -- Called when attempt at resolving current expression fails
1778 ------------------------------------
1779 -- Comes_From_Predefined_Lib_Unit --
1780 -------------------------------------
1782 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1785 Sloc (Nod) = Standard_Location
1786 or else Is_Predefined_File_Name
1787 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1788 end Comes_From_Predefined_Lib_Unit;
1790 --------------------
1791 -- Patch_Up_Value --
1792 --------------------
1794 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1796 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1798 Make_Real_Literal (Sloc (N),
1799 Realval => UR_From_Uint (Intval (N))));
1800 Set_Etype (N, Universal_Real);
1801 Set_Is_Static_Expression (N);
1803 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1805 Make_Integer_Literal (Sloc (N),
1806 Intval => UR_To_Uint (Realval (N))));
1807 Set_Etype (N, Universal_Integer);
1808 Set_Is_Static_Expression (N);
1810 elsif Nkind (N) = N_String_Literal
1811 and then Is_Character_Type (Typ)
1813 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1815 Make_Character_Literal (Sloc (N),
1817 Char_Literal_Value =>
1818 UI_From_Int (Character'Pos ('A'))));
1819 Set_Etype (N, Any_Character);
1820 Set_Is_Static_Expression (N);
1822 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1824 Make_String_Literal (Sloc (N),
1825 Strval => End_String));
1827 elsif Nkind (N) = N_Range then
1828 Patch_Up_Value (Low_Bound (N), Typ);
1829 Patch_Up_Value (High_Bound (N), Typ);
1833 -------------------------------
1834 -- Report_Ambiguous_Argument --
1835 -------------------------------
1837 procedure Report_Ambiguous_Argument is
1838 Arg : constant Node_Id := First (Parameter_Associations (N));
1843 if Nkind (Arg) = N_Function_Call
1844 and then Is_Entity_Name (Name (Arg))
1845 and then Is_Overloaded (Name (Arg))
1847 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1849 -- Could use comments on what is going on here???
1851 Get_First_Interp (Name (Arg), I, It);
1852 while Present (It.Nam) loop
1853 Error_Msg_Sloc := Sloc (It.Nam);
1855 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1856 Error_Msg_N ("interpretation (inherited) #!", Arg);
1858 Error_Msg_N ("interpretation #!", Arg);
1861 Get_Next_Interp (I, It);
1864 end Report_Ambiguous_Argument;
1866 -----------------------
1867 -- Resolution_Failed --
1868 -----------------------
1870 procedure Resolution_Failed is
1872 Patch_Up_Value (N, Typ);
1874 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1875 Set_Is_Overloaded (N, False);
1877 -- The caller will return without calling the expander, so we need
1878 -- to set the analyzed flag. Note that it is fine to set Analyzed
1879 -- to True even if we are in the middle of a shallow analysis,
1880 -- (see the spec of sem for more details) since this is an error
1881 -- situation anyway, and there is no point in repeating the
1882 -- analysis later (indeed it won't work to repeat it later, since
1883 -- we haven't got a clear resolution of which entity is being
1886 Set_Analyzed (N, True);
1888 end Resolution_Failed;
1890 -- Start of processing for Resolve
1897 -- Access attribute on remote subprogram cannot be used for a non-remote
1898 -- access-to-subprogram type.
1900 if Nkind (N) = N_Attribute_Reference
1901 and then (Attribute_Name (N) = Name_Access or else
1902 Attribute_Name (N) = Name_Unrestricted_Access or else
1903 Attribute_Name (N) = Name_Unchecked_Access)
1904 and then Comes_From_Source (N)
1905 and then Is_Entity_Name (Prefix (N))
1906 and then Is_Subprogram (Entity (Prefix (N)))
1907 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1908 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1911 ("prefix must statically denote a non-remote subprogram", N);
1914 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1916 -- If the context is a Remote_Access_To_Subprogram, access attributes
1917 -- must be resolved with the corresponding fat pointer. There is no need
1918 -- to check for the attribute name since the return type of an
1919 -- attribute is never a remote type.
1921 if Nkind (N) = N_Attribute_Reference
1922 and then Comes_From_Source (N)
1923 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
1926 Attr : constant Attribute_Id :=
1927 Get_Attribute_Id (Attribute_Name (N));
1928 Pref : constant Node_Id := Prefix (N);
1931 Is_Remote : Boolean := True;
1934 -- Check that Typ is a remote access-to-subprogram type
1936 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1938 -- Prefix (N) must statically denote a remote subprogram
1939 -- declared in a package specification.
1941 if Attr = Attribute_Access then
1942 Decl := Unit_Declaration_Node (Entity (Pref));
1944 if Nkind (Decl) = N_Subprogram_Body then
1945 Spec := Corresponding_Spec (Decl);
1947 if not No (Spec) then
1948 Decl := Unit_Declaration_Node (Spec);
1952 Spec := Parent (Decl);
1954 if not Is_Entity_Name (Prefix (N))
1955 or else Nkind (Spec) /= N_Package_Specification
1957 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1961 ("prefix must statically denote a remote subprogram ",
1966 -- If we are generating code for a distributed program.
1967 -- perform semantic checks against the corresponding
1970 if (Attr = Attribute_Access or else
1971 Attr = Attribute_Unchecked_Access or else
1972 Attr = Attribute_Unrestricted_Access)
1973 and then Full_Expander_Active
1974 and then Get_PCS_Name /= Name_No_DSA
1976 Check_Subtype_Conformant
1977 (New_Id => Entity (Prefix (N)),
1978 Old_Id => Designated_Type
1979 (Corresponding_Remote_Type (Typ)),
1983 Process_Remote_AST_Attribute (N, Typ);
1990 Debug_A_Entry ("resolving ", N);
1992 if Comes_From_Source (N) then
1993 if Is_Fixed_Point_Type (Typ) then
1994 Check_Restriction (No_Fixed_Point, N);
1996 elsif Is_Floating_Point_Type (Typ)
1997 and then Typ /= Universal_Real
1998 and then Typ /= Any_Real
2000 Check_Restriction (No_Floating_Point, N);
2004 -- Return if already analyzed
2006 if Analyzed (N) then
2007 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2010 -- Return if type = Any_Type (previous error encountered)
2012 elsif Etype (N) = Any_Type then
2013 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2017 Check_Parameterless_Call (N);
2019 -- If not overloaded, then we know the type, and all that needs doing
2020 -- is to check that this type is compatible with the context.
2022 if not Is_Overloaded (N) then
2023 Found := Covers (Typ, Etype (N));
2024 Expr_Type := Etype (N);
2026 -- In the overloaded case, we must select the interpretation that
2027 -- is compatible with the context (i.e. the type passed to Resolve)
2030 -- Loop through possible interpretations
2032 Get_First_Interp (N, I, It);
2033 Interp_Loop : while Present (It.Typ) loop
2035 -- We are only interested in interpretations that are compatible
2036 -- with the expected type, any other interpretations are ignored.
2038 if not Covers (Typ, It.Typ) then
2039 if Debug_Flag_V then
2040 Write_Str (" interpretation incompatible with context");
2045 -- Skip the current interpretation if it is disabled by an
2046 -- abstract operator. This action is performed only when the
2047 -- type against which we are resolving is the same as the
2048 -- type of the interpretation.
2050 if Ada_Version >= Ada_2005
2051 and then It.Typ = Typ
2052 and then Typ /= Universal_Integer
2053 and then Typ /= Universal_Real
2054 and then Present (It.Abstract_Op)
2059 -- First matching interpretation
2065 Expr_Type := It.Typ;
2067 -- Matching interpretation that is not the first, maybe an
2068 -- error, but there are some cases where preference rules are
2069 -- used to choose between the two possibilities. These and
2070 -- some more obscure cases are handled in Disambiguate.
2073 -- If the current statement is part of a predefined library
2074 -- unit, then all interpretations which come from user level
2075 -- packages should not be considered.
2078 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
2083 Error_Msg_Sloc := Sloc (Seen);
2084 It1 := Disambiguate (N, I1, I, Typ);
2086 -- Disambiguation has succeeded. Skip the remaining
2089 if It1 /= No_Interp then
2091 Expr_Type := It1.Typ;
2093 while Present (It.Typ) loop
2094 Get_Next_Interp (I, It);
2098 -- Before we issue an ambiguity complaint, check for
2099 -- the case of a subprogram call where at least one
2100 -- of the arguments is Any_Type, and if so, suppress
2101 -- the message, since it is a cascaded error.
2103 if Nkind_In (N, N_Function_Call,
2104 N_Procedure_Call_Statement)
2111 A := First_Actual (N);
2112 while Present (A) loop
2115 if Nkind (E) = N_Parameter_Association then
2116 E := Explicit_Actual_Parameter (E);
2119 if Etype (E) = Any_Type then
2120 if Debug_Flag_V then
2121 Write_Str ("Any_Type in call");
2132 elsif Nkind (N) in N_Binary_Op
2133 and then (Etype (Left_Opnd (N)) = Any_Type
2134 or else Etype (Right_Opnd (N)) = Any_Type)
2138 elsif Nkind (N) in N_Unary_Op
2139 and then Etype (Right_Opnd (N)) = Any_Type
2144 -- Not that special case, so issue message using the
2145 -- flag Ambiguous to control printing of the header
2146 -- message only at the start of an ambiguous set.
2148 if not Ambiguous then
2149 if Nkind (N) = N_Function_Call
2150 and then Nkind (Name (N)) = N_Explicit_Dereference
2153 ("ambiguous expression "
2154 & "(cannot resolve indirect call)!", N);
2156 Error_Msg_NE -- CODEFIX
2157 ("ambiguous expression (cannot resolve&)!",
2163 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2165 ("\\possible interpretation (inherited)#!", N);
2167 Error_Msg_N -- CODEFIX
2168 ("\\possible interpretation#!", N);
2172 (N, N_Procedure_Call_Statement, N_Function_Call)
2173 and then Present (Parameter_Associations (N))
2175 Report_Ambiguous_Argument;
2179 Error_Msg_Sloc := Sloc (It.Nam);
2181 -- By default, the error message refers to the candidate
2182 -- interpretation. But if it is a predefined operator, it
2183 -- is implicitly declared at the declaration of the type
2184 -- of the operand. Recover the sloc of that declaration
2185 -- for the error message.
2187 if Nkind (N) in N_Op
2188 and then Scope (It.Nam) = Standard_Standard
2189 and then not Is_Overloaded (Right_Opnd (N))
2190 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2193 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2195 if Comes_From_Source (Err_Type)
2196 and then Present (Parent (Err_Type))
2198 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2201 elsif Nkind (N) in N_Binary_Op
2202 and then Scope (It.Nam) = Standard_Standard
2203 and then not Is_Overloaded (Left_Opnd (N))
2204 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2207 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2209 if Comes_From_Source (Err_Type)
2210 and then Present (Parent (Err_Type))
2212 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2215 -- If this is an indirect call, use the subprogram_type
2216 -- in the message, to have a meaningful location. Also
2217 -- indicate if this is an inherited operation, created
2218 -- by a type declaration.
2220 elsif Nkind (N) = N_Function_Call
2221 and then Nkind (Name (N)) = N_Explicit_Dereference
2222 and then Is_Type (It.Nam)
2226 Sloc (Associated_Node_For_Itype (Err_Type));
2231 if Nkind (N) in N_Op
2232 and then Scope (It.Nam) = Standard_Standard
2233 and then Present (Err_Type)
2235 -- Special-case the message for universal_fixed
2236 -- operators, which are not declared with the type
2237 -- of the operand, but appear forever in Standard.
2239 if It.Typ = Universal_Fixed
2240 and then Scope (It.Nam) = Standard_Standard
2243 ("\\possible interpretation as " &
2244 "universal_fixed operation " &
2245 "(RM 4.5.5 (19))", N);
2248 ("\\possible interpretation (predefined)#!", N);
2252 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2255 ("\\possible interpretation (inherited)#!", N);
2257 Error_Msg_N -- CODEFIX
2258 ("\\possible interpretation#!", N);
2264 -- We have a matching interpretation, Expr_Type is the type
2265 -- from this interpretation, and Seen is the entity.
2267 -- For an operator, just set the entity name. The type will be
2268 -- set by the specific operator resolution routine.
2270 if Nkind (N) in N_Op then
2271 Set_Entity (N, Seen);
2272 Generate_Reference (Seen, N);
2274 elsif Nkind (N) = N_Case_Expression then
2275 Set_Etype (N, Expr_Type);
2277 elsif Nkind (N) = N_Character_Literal then
2278 Set_Etype (N, Expr_Type);
2280 elsif Nkind (N) = N_Conditional_Expression then
2281 Set_Etype (N, Expr_Type);
2283 -- AI05-0139-2: Expression is overloaded because type has
2284 -- implicit dereference. If type matches context, no implicit
2285 -- dereference is involved.
2287 elsif Has_Implicit_Dereference (Expr_Type) then
2288 Set_Etype (N, Expr_Type);
2289 Set_Is_Overloaded (N, False);
2292 elsif Is_Overloaded (N)
2293 and then Present (It.Nam)
2294 and then Ekind (It.Nam) = E_Discriminant
2295 and then Has_Implicit_Dereference (It.Nam)
2297 Build_Explicit_Dereference (N, It.Nam);
2299 -- For an explicit dereference, attribute reference, range,
2300 -- short-circuit form (which is not an operator node), or call
2301 -- with a name that is an explicit dereference, there is
2302 -- nothing to be done at this point.
2304 elsif Nkind_In (N, N_Explicit_Dereference,
2305 N_Attribute_Reference,
2307 N_Indexed_Component,
2310 N_Selected_Component,
2312 or else Nkind (Name (N)) = N_Explicit_Dereference
2316 -- For procedure or function calls, set the type of the name,
2317 -- and also the entity pointer for the prefix.
2319 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2320 and then Is_Entity_Name (Name (N))
2322 Set_Etype (Name (N), Expr_Type);
2323 Set_Entity (Name (N), Seen);
2324 Generate_Reference (Seen, Name (N));
2326 elsif Nkind (N) = N_Function_Call
2327 and then Nkind (Name (N)) = N_Selected_Component
2329 Set_Etype (Name (N), Expr_Type);
2330 Set_Entity (Selector_Name (Name (N)), Seen);
2331 Generate_Reference (Seen, Selector_Name (Name (N)));
2333 -- For all other cases, just set the type of the Name
2336 Set_Etype (Name (N), Expr_Type);
2343 -- Move to next interpretation
2345 exit Interp_Loop when No (It.Typ);
2347 Get_Next_Interp (I, It);
2348 end loop Interp_Loop;
2351 -- At this stage Found indicates whether or not an acceptable
2352 -- interpretation exists. If not, then we have an error, except that if
2353 -- the context is Any_Type as a result of some other error, then we
2354 -- suppress the error report.
2357 if Typ /= Any_Type then
2359 -- If type we are looking for is Void, then this is the procedure
2360 -- call case, and the error is simply that what we gave is not a
2361 -- procedure name (we think of procedure calls as expressions with
2362 -- types internally, but the user doesn't think of them this way!)
2364 if Typ = Standard_Void_Type then
2366 -- Special case message if function used as a procedure
2368 if Nkind (N) = N_Procedure_Call_Statement
2369 and then Is_Entity_Name (Name (N))
2370 and then Ekind (Entity (Name (N))) = E_Function
2373 ("cannot use function & in a procedure call",
2374 Name (N), Entity (Name (N)));
2376 -- Otherwise give general message (not clear what cases this
2377 -- covers, but no harm in providing for them!)
2380 Error_Msg_N ("expect procedure name in procedure call", N);
2385 -- Otherwise we do have a subexpression with the wrong type
2387 -- Check for the case of an allocator which uses an access type
2388 -- instead of the designated type. This is a common error and we
2389 -- specialize the message, posting an error on the operand of the
2390 -- allocator, complaining that we expected the designated type of
2393 elsif Nkind (N) = N_Allocator
2394 and then Ekind (Typ) in Access_Kind
2395 and then Ekind (Etype (N)) in Access_Kind
2396 and then Designated_Type (Etype (N)) = Typ
2398 Wrong_Type (Expression (N), Designated_Type (Typ));
2401 -- Check for view mismatch on Null in instances, for which the
2402 -- view-swapping mechanism has no identifier.
2404 elsif (In_Instance or else In_Inlined_Body)
2405 and then (Nkind (N) = N_Null)
2406 and then Is_Private_Type (Typ)
2407 and then Is_Access_Type (Full_View (Typ))
2409 Resolve (N, Full_View (Typ));
2413 -- Check for an aggregate. Sometimes we can get bogus aggregates
2414 -- from misuse of parentheses, and we are about to complain about
2415 -- the aggregate without even looking inside it.
2417 -- Instead, if we have an aggregate of type Any_Composite, then
2418 -- analyze and resolve the component fields, and then only issue
2419 -- another message if we get no errors doing this (otherwise
2420 -- assume that the errors in the aggregate caused the problem).
2422 elsif Nkind (N) = N_Aggregate
2423 and then Etype (N) = Any_Composite
2425 -- Disable expansion in any case. If there is a type mismatch
2426 -- it may be fatal to try to expand the aggregate. The flag
2427 -- would otherwise be set to false when the error is posted.
2429 Expander_Active := False;
2432 procedure Check_Aggr (Aggr : Node_Id);
2433 -- Check one aggregate, and set Found to True if we have a
2434 -- definite error in any of its elements
2436 procedure Check_Elmt (Aelmt : Node_Id);
2437 -- Check one element of aggregate and set Found to True if
2438 -- we definitely have an error in the element.
2444 procedure Check_Aggr (Aggr : Node_Id) is
2448 if Present (Expressions (Aggr)) then
2449 Elmt := First (Expressions (Aggr));
2450 while Present (Elmt) loop
2456 if Present (Component_Associations (Aggr)) then
2457 Elmt := First (Component_Associations (Aggr));
2458 while Present (Elmt) loop
2460 -- If this is a default-initialized component, then
2461 -- there is nothing to check. The box will be
2462 -- replaced by the appropriate call during late
2465 if not Box_Present (Elmt) then
2466 Check_Elmt (Expression (Elmt));
2478 procedure Check_Elmt (Aelmt : Node_Id) is
2480 -- If we have a nested aggregate, go inside it (to
2481 -- attempt a naked analyze-resolve of the aggregate can
2482 -- cause undesirable cascaded errors). Do not resolve
2483 -- expression if it needs a type from context, as for
2484 -- integer * fixed expression.
2486 if Nkind (Aelmt) = N_Aggregate then
2492 if not Is_Overloaded (Aelmt)
2493 and then Etype (Aelmt) /= Any_Fixed
2498 if Etype (Aelmt) = Any_Type then
2509 -- If an error message was issued already, Found got reset to
2510 -- True, so if it is still False, issue standard Wrong_Type msg.
2513 if Is_Overloaded (N)
2514 and then Nkind (N) = N_Function_Call
2517 Subp_Name : Node_Id;
2519 if Is_Entity_Name (Name (N)) then
2520 Subp_Name := Name (N);
2522 elsif Nkind (Name (N)) = N_Selected_Component then
2524 -- Protected operation: retrieve operation name
2526 Subp_Name := Selector_Name (Name (N));
2529 raise Program_Error;
2532 Error_Msg_Node_2 := Typ;
2533 Error_Msg_NE ("no visible interpretation of&" &
2534 " matches expected type&", N, Subp_Name);
2537 if All_Errors_Mode then
2539 Index : Interp_Index;
2543 Error_Msg_N ("\\possible interpretations:", N);
2545 Get_First_Interp (Name (N), Index, It);
2546 while Present (It.Nam) loop
2547 Error_Msg_Sloc := Sloc (It.Nam);
2548 Error_Msg_Node_2 := It.Nam;
2550 ("\\ type& for & declared#", N, It.Typ);
2551 Get_Next_Interp (Index, It);
2556 Error_Msg_N ("\use -gnatf for details", N);
2560 Wrong_Type (N, Typ);
2568 -- Test if we have more than one interpretation for the context
2570 elsif Ambiguous then
2574 -- Here we have an acceptable interpretation for the context
2577 -- Propagate type information and normalize tree for various
2578 -- predefined operations. If the context only imposes a class of
2579 -- types, rather than a specific type, propagate the actual type
2582 if Typ = Any_Integer or else
2583 Typ = Any_Boolean or else
2584 Typ = Any_Modular or else
2585 Typ = Any_Real or else
2588 Ctx_Type := Expr_Type;
2590 -- Any_Fixed is legal in a real context only if a specific fixed-
2591 -- point type is imposed. If Norman Cohen can be confused by this,
2592 -- it deserves a separate message.
2595 and then Expr_Type = Any_Fixed
2597 Error_Msg_N ("illegal context for mixed mode operation", N);
2598 Set_Etype (N, Universal_Real);
2599 Ctx_Type := Universal_Real;
2603 -- A user-defined operator is transformed into a function call at
2604 -- this point, so that further processing knows that operators are
2605 -- really operators (i.e. are predefined operators). User-defined
2606 -- operators that are intrinsic are just renamings of the predefined
2607 -- ones, and need not be turned into calls either, but if they rename
2608 -- a different operator, we must transform the node accordingly.
2609 -- Instantiations of Unchecked_Conversion are intrinsic but are
2610 -- treated as functions, even if given an operator designator.
2612 if Nkind (N) in N_Op
2613 and then Present (Entity (N))
2614 and then Ekind (Entity (N)) /= E_Operator
2617 if not Is_Predefined_Op (Entity (N)) then
2618 Rewrite_Operator_As_Call (N, Entity (N));
2620 elsif Present (Alias (Entity (N)))
2622 Nkind (Parent (Parent (Entity (N)))) =
2623 N_Subprogram_Renaming_Declaration
2625 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2627 -- If the node is rewritten, it will be fully resolved in
2628 -- Rewrite_Renamed_Operator.
2630 if Analyzed (N) then
2636 case N_Subexpr'(Nkind (N)) is
2638 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2640 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2642 when N_Short_Circuit
2643 => Resolve_Short_Circuit (N, Ctx_Type);
2645 when N_Attribute_Reference
2646 => Resolve_Attribute (N, Ctx_Type);
2648 when N_Case_Expression
2649 => Resolve_Case_Expression (N, Ctx_Type);
2651 when N_Character_Literal
2652 => Resolve_Character_Literal (N, Ctx_Type);
2654 when N_Conditional_Expression
2655 => Resolve_Conditional_Expression (N, Ctx_Type);
2657 when N_Expanded_Name
2658 => Resolve_Entity_Name (N, Ctx_Type);
2660 when N_Explicit_Dereference
2661 => Resolve_Explicit_Dereference (N, Ctx_Type);
2663 when N_Expression_With_Actions
2664 => Resolve_Expression_With_Actions (N, Ctx_Type);
2666 when N_Extension_Aggregate
2667 => Resolve_Extension_Aggregate (N, Ctx_Type);
2669 when N_Function_Call
2670 => Resolve_Call (N, Ctx_Type);
2673 => Resolve_Entity_Name (N, Ctx_Type);
2675 when N_Indexed_Component
2676 => Resolve_Indexed_Component (N, Ctx_Type);
2678 when N_Integer_Literal
2679 => Resolve_Integer_Literal (N, Ctx_Type);
2681 when N_Membership_Test
2682 => Resolve_Membership_Op (N, Ctx_Type);
2684 when N_Null => Resolve_Null (N, Ctx_Type);
2686 when N_Op_And | N_Op_Or | N_Op_Xor
2687 => Resolve_Logical_Op (N, Ctx_Type);
2689 when N_Op_Eq | N_Op_Ne
2690 => Resolve_Equality_Op (N, Ctx_Type);
2692 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2693 => Resolve_Comparison_Op (N, Ctx_Type);
2695 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2697 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2698 N_Op_Divide | N_Op_Mod | N_Op_Rem
2700 => Resolve_Arithmetic_Op (N, Ctx_Type);
2702 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2704 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2706 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2707 => Resolve_Unary_Op (N, Ctx_Type);
2709 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2711 when N_Procedure_Call_Statement
2712 => Resolve_Call (N, Ctx_Type);
2714 when N_Operator_Symbol
2715 => Resolve_Operator_Symbol (N, Ctx_Type);
2717 when N_Qualified_Expression
2718 => Resolve_Qualified_Expression (N, Ctx_Type);
2720 when N_Quantified_Expression
2721 => Resolve_Quantified_Expression (N, Ctx_Type);
2723 when N_Raise_xxx_Error
2724 => Set_Etype (N, Ctx_Type);
2726 when N_Range => Resolve_Range (N, Ctx_Type);
2729 => Resolve_Real_Literal (N, Ctx_Type);
2731 when N_Reference => Resolve_Reference (N, Ctx_Type);
2733 when N_Selected_Component
2734 => Resolve_Selected_Component (N, Ctx_Type);
2736 when N_Slice => Resolve_Slice (N, Ctx_Type);
2738 when N_String_Literal
2739 => Resolve_String_Literal (N, Ctx_Type);
2741 when N_Subprogram_Info
2742 => Resolve_Subprogram_Info (N, Ctx_Type);
2744 when N_Type_Conversion
2745 => Resolve_Type_Conversion (N, Ctx_Type);
2747 when N_Unchecked_Expression =>
2748 Resolve_Unchecked_Expression (N, Ctx_Type);
2750 when N_Unchecked_Type_Conversion =>
2751 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2754 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2755 -- expression of an anonymous access type that occurs in the context
2756 -- of a named general access type, except when the expression is that
2757 -- of a membership test. This ensures proper legality checking in
2758 -- terms of allowed conversions (expressions that would be illegal to
2759 -- convert implicitly are allowed in membership tests).
2761 if Ada_Version >= Ada_2012
2762 and then Ekind (Ctx_Type) = E_General_Access_Type
2763 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2764 and then Nkind (Parent (N)) not in N_Membership_Test
2766 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2767 Analyze_And_Resolve (N, Ctx_Type);
2770 -- If the subexpression was replaced by a non-subexpression, then
2771 -- all we do is to expand it. The only legitimate case we know of
2772 -- is converting procedure call statement to entry call statements,
2773 -- but there may be others, so we are making this test general.
2775 if Nkind (N) not in N_Subexpr then
2776 Debug_A_Exit ("resolving ", N, " (done)");
2781 -- AI05-144-2: Check dangerous order dependence within an expression
2782 -- that is not a subexpression. Exclude RHS of an assignment, because
2783 -- both sides may have side-effects and the check must be performed
2784 -- over the statement.
2786 if Nkind (Parent (N)) not in N_Subexpr
2787 and then Nkind (Parent (N)) /= N_Assignment_Statement
2788 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
2790 Check_Order_Dependence;
2793 -- The expression is definitely NOT overloaded at this point, so
2794 -- we reset the Is_Overloaded flag to avoid any confusion when
2795 -- reanalyzing the node.
2797 Set_Is_Overloaded (N, False);
2799 -- Freeze expression type, entity if it is a name, and designated
2800 -- type if it is an allocator (RM 13.14(10,11,13)).
2802 -- Now that the resolution of the type of the node is complete, and
2803 -- we did not detect an error, we can expand this node. We skip the
2804 -- expand call if we are in a default expression, see section
2805 -- "Handling of Default Expressions" in Sem spec.
2807 Debug_A_Exit ("resolving ", N, " (done)");
2809 -- We unconditionally freeze the expression, even if we are in
2810 -- default expression mode (the Freeze_Expression routine tests this
2811 -- flag and only freezes static types if it is set).
2813 Freeze_Expression (N);
2815 -- Now we can do the expansion
2825 -- Version with check(s) suppressed
2827 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2829 if Suppress = All_Checks then
2831 Svg : constant Suppress_Array := Scope_Suppress;
2833 Scope_Suppress := (others => True);
2835 Scope_Suppress := Svg;
2840 Svg : constant Boolean := Scope_Suppress (Suppress);
2842 Scope_Suppress (Suppress) := True;
2844 Scope_Suppress (Suppress) := Svg;
2853 -- Version with implicit type
2855 procedure Resolve (N : Node_Id) is
2857 Resolve (N, Etype (N));
2860 ---------------------
2861 -- Resolve_Actuals --
2862 ---------------------
2864 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2865 Loc : constant Source_Ptr := Sloc (N);
2870 Prev : Node_Id := Empty;
2873 procedure Check_Argument_Order;
2874 -- Performs a check for the case where the actuals are all simple
2875 -- identifiers that correspond to the formal names, but in the wrong
2876 -- order, which is considered suspicious and cause for a warning.
2878 procedure Check_Prefixed_Call;
2879 -- If the original node is an overloaded call in prefix notation,
2880 -- insert an 'Access or a dereference as needed over the first actual.
2881 -- Try_Object_Operation has already verified that there is a valid
2882 -- interpretation, but the form of the actual can only be determined
2883 -- once the primitive operation is identified.
2885 procedure Insert_Default;
2886 -- If the actual is missing in a call, insert in the actuals list
2887 -- an instance of the default expression. The insertion is always
2888 -- a named association.
2890 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2891 -- Check whether T1 and T2, or their full views, are derived from a
2892 -- common type. Used to enforce the restrictions on array conversions
2895 function Static_Concatenation (N : Node_Id) return Boolean;
2896 -- Predicate to determine whether an actual that is a concatenation
2897 -- will be evaluated statically and does not need a transient scope.
2898 -- This must be determined before the actual is resolved and expanded
2899 -- because if needed the transient scope must be introduced earlier.
2901 --------------------------
2902 -- Check_Argument_Order --
2903 --------------------------
2905 procedure Check_Argument_Order is
2907 -- Nothing to do if no parameters, or original node is neither a
2908 -- function call nor a procedure call statement (happens in the
2909 -- operator-transformed-to-function call case), or the call does
2910 -- not come from source, or this warning is off.
2912 if not Warn_On_Parameter_Order
2913 or else No (Parameter_Associations (N))
2914 or else not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2916 or else not Comes_From_Source (N)
2922 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2925 -- Nothing to do if only one parameter
2931 -- Here if at least two arguments
2934 Actuals : array (1 .. Nargs) of Node_Id;
2938 Wrong_Order : Boolean := False;
2939 -- Set True if an out of order case is found
2942 -- Collect identifier names of actuals, fail if any actual is
2943 -- not a simple identifier, and record max length of name.
2945 Actual := First (Parameter_Associations (N));
2946 for J in Actuals'Range loop
2947 if Nkind (Actual) /= N_Identifier then
2950 Actuals (J) := Actual;
2955 -- If we got this far, all actuals are identifiers and the list
2956 -- of their names is stored in the Actuals array.
2958 Formal := First_Formal (Nam);
2959 for J in Actuals'Range loop
2961 -- If we ran out of formals, that's odd, probably an error
2962 -- which will be detected elsewhere, but abandon the search.
2968 -- If name matches and is in order OK
2970 if Chars (Formal) = Chars (Actuals (J)) then
2974 -- If no match, see if it is elsewhere in list and if so
2975 -- flag potential wrong order if type is compatible.
2977 for K in Actuals'Range loop
2978 if Chars (Formal) = Chars (Actuals (K))
2980 Has_Compatible_Type (Actuals (K), Etype (Formal))
2982 Wrong_Order := True;
2992 <<Continue>> Next_Formal (Formal);
2995 -- If Formals left over, also probably an error, skip warning
2997 if Present (Formal) then
3001 -- Here we give the warning if something was out of order
3005 ("actuals for this call may be in wrong order?", N);
3009 end Check_Argument_Order;
3011 -------------------------
3012 -- Check_Prefixed_Call --
3013 -------------------------
3015 procedure Check_Prefixed_Call is
3016 Act : constant Node_Id := First_Actual (N);
3017 A_Type : constant Entity_Id := Etype (Act);
3018 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3019 Orig : constant Node_Id := Original_Node (N);
3023 -- Check whether the call is a prefixed call, with or without
3024 -- additional actuals.
3026 if Nkind (Orig) = N_Selected_Component
3028 (Nkind (Orig) = N_Indexed_Component
3029 and then Nkind (Prefix (Orig)) = N_Selected_Component
3030 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3031 and then Is_Entity_Name (Act)
3032 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3034 if Is_Access_Type (A_Type)
3035 and then not Is_Access_Type (F_Type)
3037 -- Introduce dereference on object in prefix
3040 Make_Explicit_Dereference (Sloc (Act),
3041 Prefix => Relocate_Node (Act));
3042 Rewrite (Act, New_A);
3045 elsif Is_Access_Type (F_Type)
3046 and then not Is_Access_Type (A_Type)
3048 -- Introduce an implicit 'Access in prefix
3050 if not Is_Aliased_View (Act) then
3052 ("object in prefixed call to& must be aliased"
3053 & " (RM-2005 4.3.1 (13))",
3058 Make_Attribute_Reference (Loc,
3059 Attribute_Name => Name_Access,
3060 Prefix => Relocate_Node (Act)));
3065 end Check_Prefixed_Call;
3067 --------------------
3068 -- Insert_Default --
3069 --------------------
3071 procedure Insert_Default is
3076 -- Missing argument in call, nothing to insert
3078 if No (Default_Value (F)) then
3082 -- Note that we do a full New_Copy_Tree, so that any associated
3083 -- Itypes are properly copied. This may not be needed any more,
3084 -- but it does no harm as a safety measure! Defaults of a generic
3085 -- formal may be out of bounds of the corresponding actual (see
3086 -- cc1311b) and an additional check may be required.
3091 New_Scope => Current_Scope,
3094 if Is_Concurrent_Type (Scope (Nam))
3095 and then Has_Discriminants (Scope (Nam))
3097 Replace_Actual_Discriminants (N, Actval);
3100 if Is_Overloadable (Nam)
3101 and then Present (Alias (Nam))
3103 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3104 and then not Is_Tagged_Type (Etype (F))
3106 -- If default is a real literal, do not introduce a
3107 -- conversion whose effect may depend on the run-time
3108 -- size of universal real.
3110 if Nkind (Actval) = N_Real_Literal then
3111 Set_Etype (Actval, Base_Type (Etype (F)));
3113 Actval := Unchecked_Convert_To (Etype (F), Actval);
3117 if Is_Scalar_Type (Etype (F)) then
3118 Enable_Range_Check (Actval);
3121 Set_Parent (Actval, N);
3123 -- Resolve aggregates with their base type, to avoid scope
3124 -- anomalies: the subtype was first built in the subprogram
3125 -- declaration, and the current call may be nested.
3127 if Nkind (Actval) = N_Aggregate then
3128 Analyze_And_Resolve (Actval, Etype (F));
3130 Analyze_And_Resolve (Actval, Etype (Actval));
3134 Set_Parent (Actval, N);
3136 -- See note above concerning aggregates
3138 if Nkind (Actval) = N_Aggregate
3139 and then Has_Discriminants (Etype (Actval))
3141 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3143 -- Resolve entities with their own type, which may differ from
3144 -- the type of a reference in a generic context (the view
3145 -- swapping mechanism did not anticipate the re-analysis of
3146 -- default values in calls).
3148 elsif Is_Entity_Name (Actval) then
3149 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3152 Analyze_And_Resolve (Actval, Etype (Actval));
3156 -- If default is a tag indeterminate function call, propagate tag
3157 -- to obtain proper dispatching.
3159 if Is_Controlling_Formal (F)
3160 and then Nkind (Default_Value (F)) = N_Function_Call
3162 Set_Is_Controlling_Actual (Actval);
3167 -- If the default expression raises constraint error, then just
3168 -- silently replace it with an N_Raise_Constraint_Error node, since
3169 -- we already gave the warning on the subprogram spec. If node is
3170 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3171 -- the warnings removal machinery.
3173 if Raises_Constraint_Error (Actval)
3174 and then Nkind (Actval) /= N_Raise_Constraint_Error
3177 Make_Raise_Constraint_Error (Loc,
3178 Reason => CE_Range_Check_Failed));
3179 Set_Raises_Constraint_Error (Actval);
3180 Set_Etype (Actval, Etype (F));
3184 Make_Parameter_Association (Loc,
3185 Explicit_Actual_Parameter => Actval,
3186 Selector_Name => Make_Identifier (Loc, Chars (F)));
3188 -- Case of insertion is first named actual
3190 if No (Prev) or else
3191 Nkind (Parent (Prev)) /= N_Parameter_Association
3193 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3194 Set_First_Named_Actual (N, Actval);
3197 if No (Parameter_Associations (N)) then
3198 Set_Parameter_Associations (N, New_List (Assoc));
3200 Append (Assoc, Parameter_Associations (N));
3204 Insert_After (Prev, Assoc);
3207 -- Case of insertion is not first named actual
3210 Set_Next_Named_Actual
3211 (Assoc, Next_Named_Actual (Parent (Prev)));
3212 Set_Next_Named_Actual (Parent (Prev), Actval);
3213 Append (Assoc, Parameter_Associations (N));
3216 Mark_Rewrite_Insertion (Assoc);
3217 Mark_Rewrite_Insertion (Actval);
3226 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3227 FT1 : Entity_Id := T1;
3228 FT2 : Entity_Id := T2;
3231 if Is_Private_Type (T1)
3232 and then Present (Full_View (T1))
3234 FT1 := Full_View (T1);
3237 if Is_Private_Type (T2)
3238 and then Present (Full_View (T2))
3240 FT2 := Full_View (T2);
3243 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3246 --------------------------
3247 -- Static_Concatenation --
3248 --------------------------
3250 function Static_Concatenation (N : Node_Id) return Boolean is
3253 when N_String_Literal =>
3258 -- Concatenation is static when both operands are static and
3259 -- the concatenation operator is a predefined one.
3261 return Scope (Entity (N)) = Standard_Standard
3263 Static_Concatenation (Left_Opnd (N))
3265 Static_Concatenation (Right_Opnd (N));
3268 if Is_Entity_Name (N) then
3270 Ent : constant Entity_Id := Entity (N);
3272 return Ekind (Ent) = E_Constant
3273 and then Present (Constant_Value (Ent))
3275 Is_Static_Expression (Constant_Value (Ent));
3282 end Static_Concatenation;
3284 -- Start of processing for Resolve_Actuals
3287 Check_Argument_Order;
3289 if Present (First_Actual (N)) then
3290 Check_Prefixed_Call;
3293 A := First_Actual (N);
3294 F := First_Formal (Nam);
3295 while Present (F) loop
3296 if No (A) and then Needs_No_Actuals (Nam) then
3299 -- If we have an error in any actual or formal, indicated by a type
3300 -- of Any_Type, then abandon resolution attempt, and set result type
3303 elsif (Present (A) and then Etype (A) = Any_Type)
3304 or else Etype (F) = Any_Type
3306 Set_Etype (N, Any_Type);
3310 -- Case where actual is present
3312 -- If the actual is an entity, generate a reference to it now. We
3313 -- do this before the actual is resolved, because a formal of some
3314 -- protected subprogram, or a task discriminant, will be rewritten
3315 -- during expansion, and the source entity reference may be lost.
3318 and then Is_Entity_Name (A)
3319 and then Comes_From_Source (N)
3321 Orig_A := Entity (A);
3323 if Present (Orig_A) then
3324 if Is_Formal (Orig_A)
3325 and then Ekind (F) /= E_In_Parameter
3327 Generate_Reference (Orig_A, A, 'm');
3329 elsif not Is_Overloaded (A) then
3330 Generate_Reference (Orig_A, A);
3336 and then (Nkind (Parent (A)) /= N_Parameter_Association
3337 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3339 -- If style checking mode on, check match of formal name
3342 if Nkind (Parent (A)) = N_Parameter_Association then
3343 Check_Identifier (Selector_Name (Parent (A)), F);
3347 -- If the formal is Out or In_Out, do not resolve and expand the
3348 -- conversion, because it is subsequently expanded into explicit
3349 -- temporaries and assignments. However, the object of the
3350 -- conversion can be resolved. An exception is the case of tagged
3351 -- type conversion with a class-wide actual. In that case we want
3352 -- the tag check to occur and no temporary will be needed (no
3353 -- representation change can occur) and the parameter is passed by
3354 -- reference, so we go ahead and resolve the type conversion.
3355 -- Another exception is the case of reference to component or
3356 -- subcomponent of a bit-packed array, in which case we want to
3357 -- defer expansion to the point the in and out assignments are
3360 if Ekind (F) /= E_In_Parameter
3361 and then Nkind (A) = N_Type_Conversion
3362 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3364 if Ekind (F) = E_In_Out_Parameter
3365 and then Is_Array_Type (Etype (F))
3367 -- In a view conversion, the conversion must be legal in
3368 -- both directions, and thus both component types must be
3369 -- aliased, or neither (4.6 (8)).
3371 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3372 -- the privacy requirement should not apply to generic
3373 -- types, and should be checked in an instance. ARG query
3376 if Has_Aliased_Components (Etype (Expression (A))) /=
3377 Has_Aliased_Components (Etype (F))
3380 ("both component types in a view conversion must be"
3381 & " aliased, or neither", A);
3383 -- Comment here??? what set of cases???
3386 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3388 -- Check view conv between unrelated by ref array types
3390 if Is_By_Reference_Type (Etype (F))
3391 or else Is_By_Reference_Type (Etype (Expression (A)))
3394 ("view conversion between unrelated by reference " &
3395 "array types not allowed (\'A'I-00246)", A);
3397 -- In Ada 2005 mode, check view conversion component
3398 -- type cannot be private, tagged, or volatile. Note
3399 -- that we only apply this to source conversions. The
3400 -- generated code can contain conversions which are
3401 -- not subject to this test, and we cannot extract the
3402 -- component type in such cases since it is not present.
3404 elsif Comes_From_Source (A)
3405 and then Ada_Version >= Ada_2005
3408 Comp_Type : constant Entity_Id :=
3410 (Etype (Expression (A)));
3412 if (Is_Private_Type (Comp_Type)
3413 and then not Is_Generic_Type (Comp_Type))
3414 or else Is_Tagged_Type (Comp_Type)
3415 or else Is_Volatile (Comp_Type)
3418 ("component type of a view conversion cannot"
3419 & " be private, tagged, or volatile"
3428 -- Resolve expression if conversion is all OK
3430 if (Conversion_OK (A)
3431 or else Valid_Conversion (A, Etype (A), Expression (A)))
3432 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3434 Resolve (Expression (A));
3437 -- If the actual is a function call that returns a limited
3438 -- unconstrained object that needs finalization, create a
3439 -- transient scope for it, so that it can receive the proper
3440 -- finalization list.
3442 elsif Nkind (A) = N_Function_Call
3443 and then Is_Limited_Record (Etype (F))
3444 and then not Is_Constrained (Etype (F))
3445 and then Full_Expander_Active
3446 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3448 Establish_Transient_Scope (A, False);
3449 Resolve (A, Etype (F));
3451 -- A small optimization: if one of the actuals is a concatenation
3452 -- create a block around a procedure call to recover stack space.
3453 -- This alleviates stack usage when several procedure calls in
3454 -- the same statement list use concatenation. We do not perform
3455 -- this wrapping for code statements, where the argument is a
3456 -- static string, and we want to preserve warnings involving
3457 -- sequences of such statements.
3459 elsif Nkind (A) = N_Op_Concat
3460 and then Nkind (N) = N_Procedure_Call_Statement
3461 and then Full_Expander_Active
3463 not (Is_Intrinsic_Subprogram (Nam)
3464 and then Chars (Nam) = Name_Asm)
3465 and then not Static_Concatenation (A)
3467 Establish_Transient_Scope (A, False);
3468 Resolve (A, Etype (F));
3471 if Nkind (A) = N_Type_Conversion
3472 and then Is_Array_Type (Etype (F))
3473 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3475 (Is_Limited_Type (Etype (F))
3476 or else Is_Limited_Type (Etype (Expression (A))))
3479 ("conversion between unrelated limited array types " &
3480 "not allowed (\A\I-00246)", A);
3482 if Is_Limited_Type (Etype (F)) then
3483 Explain_Limited_Type (Etype (F), A);
3486 if Is_Limited_Type (Etype (Expression (A))) then
3487 Explain_Limited_Type (Etype (Expression (A)), A);
3491 -- (Ada 2005: AI-251): If the actual is an allocator whose
3492 -- directly designated type is a class-wide interface, we build
3493 -- an anonymous access type to use it as the type of the
3494 -- allocator. Later, when the subprogram call is expanded, if
3495 -- the interface has a secondary dispatch table the expander
3496 -- will add a type conversion to force the correct displacement
3499 if Nkind (A) = N_Allocator then
3501 DDT : constant Entity_Id :=
3502 Directly_Designated_Type (Base_Type (Etype (F)));
3504 New_Itype : Entity_Id;
3507 if Is_Class_Wide_Type (DDT)
3508 and then Is_Interface (DDT)
3510 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3511 Set_Etype (New_Itype, Etype (A));
3512 Set_Directly_Designated_Type (New_Itype,
3513 Directly_Designated_Type (Etype (A)));
3514 Set_Etype (A, New_Itype);
3517 -- Ada 2005, AI-162:If the actual is an allocator, the
3518 -- innermost enclosing statement is the master of the
3519 -- created object. This needs to be done with expansion
3520 -- enabled only, otherwise the transient scope will not
3521 -- be removed in the expansion of the wrapped construct.
3523 if (Is_Controlled (DDT) or else Has_Task (DDT))
3524 and then Full_Expander_Active
3526 Establish_Transient_Scope (A, False);
3531 -- (Ada 2005): The call may be to a primitive operation of
3532 -- a tagged synchronized type, declared outside of the type.
3533 -- In this case the controlling actual must be converted to
3534 -- its corresponding record type, which is the formal type.
3535 -- The actual may be a subtype, either because of a constraint
3536 -- or because it is a generic actual, so use base type to
3537 -- locate concurrent type.
3539 F_Typ := Base_Type (Etype (F));
3541 if Is_Tagged_Type (F_Typ)
3542 and then (Is_Concurrent_Type (F_Typ)
3543 or else Is_Concurrent_Record_Type (F_Typ))
3545 -- If the actual is overloaded, look for an interpretation
3546 -- that has a synchronized type.
3548 if not Is_Overloaded (A) then
3549 A_Typ := Base_Type (Etype (A));
3553 Index : Interp_Index;
3557 Get_First_Interp (A, Index, It);
3558 while Present (It.Typ) loop
3559 if Is_Concurrent_Type (It.Typ)
3560 or else Is_Concurrent_Record_Type (It.Typ)
3562 A_Typ := Base_Type (It.Typ);
3566 Get_Next_Interp (Index, It);
3572 Full_A_Typ : Entity_Id;
3575 if Present (Full_View (A_Typ)) then
3576 Full_A_Typ := Base_Type (Full_View (A_Typ));
3578 Full_A_Typ := A_Typ;
3581 -- Tagged synchronized type (case 1): the actual is a
3584 if Is_Concurrent_Type (A_Typ)
3585 and then Corresponding_Record_Type (A_Typ) = F_Typ
3588 Unchecked_Convert_To
3589 (Corresponding_Record_Type (A_Typ), A));
3590 Resolve (A, Etype (F));
3592 -- Tagged synchronized type (case 2): the formal is a
3595 elsif Ekind (Full_A_Typ) = E_Record_Type
3597 (Corresponding_Concurrent_Type (Full_A_Typ))
3598 and then Is_Concurrent_Type (F_Typ)
3599 and then Present (Corresponding_Record_Type (F_Typ))
3600 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3602 Resolve (A, Corresponding_Record_Type (F_Typ));
3607 Resolve (A, Etype (F));
3612 -- not a synchronized operation.
3614 Resolve (A, Etype (F));
3621 if Comes_From_Source (Original_Node (N))
3622 and then Nkind_In (Original_Node (N), N_Function_Call,
3623 N_Procedure_Call_Statement)
3625 -- In formal mode, check that actual parameters matching
3626 -- formals of tagged types are objects (or ancestor type
3627 -- conversions of objects), not general expressions.
3629 if Is_Actual_Tagged_Parameter (A) then
3630 if Is_SPARK_Object_Reference (A) then
3633 elsif Nkind (A) = N_Type_Conversion then
3635 Operand : constant Node_Id := Expression (A);
3636 Operand_Typ : constant Entity_Id := Etype (Operand);
3637 Target_Typ : constant Entity_Id := A_Typ;
3640 if not Is_SPARK_Object_Reference (Operand) then
3641 Check_SPARK_Restriction
3642 ("object required", Operand);
3644 -- In formal mode, the only view conversions are those
3645 -- involving ancestor conversion of an extended type.
3648 (Is_Tagged_Type (Target_Typ)
3649 and then not Is_Class_Wide_Type (Target_Typ)
3650 and then Is_Tagged_Type (Operand_Typ)
3651 and then not Is_Class_Wide_Type (Operand_Typ)
3652 and then Is_Ancestor (Target_Typ, Operand_Typ))
3655 (F, E_Out_Parameter, E_In_Out_Parameter)
3657 Check_SPARK_Restriction
3658 ("ancestor conversion is the only permitted "
3659 & "view conversion", A);
3661 Check_SPARK_Restriction
3662 ("ancestor conversion required", A);
3671 Check_SPARK_Restriction ("object required", A);
3674 -- In formal mode, the only view conversions are those
3675 -- involving ancestor conversion of an extended type.
3677 elsif Nkind (A) = N_Type_Conversion
3678 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3680 Check_SPARK_Restriction
3681 ("ancestor conversion is the only permitted view "
3686 -- Save actual for subsequent check on order dependence, and
3687 -- indicate whether actual is modifiable. For AI05-0144-2.
3689 Save_Actual (A, Ekind (F) /= E_In_Parameter);
3691 -- For mode IN, if actual is an entity, and the type of the formal
3692 -- has warnings suppressed, then we reset Never_Set_In_Source for
3693 -- the calling entity. The reason for this is to catch cases like
3694 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3695 -- uses trickery to modify an IN parameter.
3697 if Ekind (F) = E_In_Parameter
3698 and then Is_Entity_Name (A)
3699 and then Present (Entity (A))
3700 and then Ekind (Entity (A)) = E_Variable
3701 and then Has_Warnings_Off (F_Typ)
3703 Set_Never_Set_In_Source (Entity (A), False);
3706 -- Perform error checks for IN and IN OUT parameters
3708 if Ekind (F) /= E_Out_Parameter then
3710 -- Check unset reference. For scalar parameters, it is clearly
3711 -- wrong to pass an uninitialized value as either an IN or
3712 -- IN-OUT parameter. For composites, it is also clearly an
3713 -- error to pass a completely uninitialized value as an IN
3714 -- parameter, but the case of IN OUT is trickier. We prefer
3715 -- not to give a warning here. For example, suppose there is
3716 -- a routine that sets some component of a record to False.
3717 -- It is perfectly reasonable to make this IN-OUT and allow
3718 -- either initialized or uninitialized records to be passed
3721 -- For partially initialized composite values, we also avoid
3722 -- warnings, since it is quite likely that we are passing a
3723 -- partially initialized value and only the initialized fields
3724 -- will in fact be read in the subprogram.
3726 if Is_Scalar_Type (A_Typ)
3727 or else (Ekind (F) = E_In_Parameter
3728 and then not Is_Partially_Initialized_Type (A_Typ))
3730 Check_Unset_Reference (A);
3733 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3734 -- actual to a nested call, since this is case of reading an
3735 -- out parameter, which is not allowed.
3737 if Ada_Version = Ada_83
3738 and then Is_Entity_Name (A)
3739 and then Ekind (Entity (A)) = E_Out_Parameter
3741 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3745 -- Case of OUT or IN OUT parameter
3747 if Ekind (F) /= E_In_Parameter then
3749 -- For an Out parameter, check for useless assignment. Note
3750 -- that we can't set Last_Assignment this early, because we may
3751 -- kill current values in Resolve_Call, and that call would
3752 -- clobber the Last_Assignment field.
3754 -- Note: call Warn_On_Useless_Assignment before doing the check
3755 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3756 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3757 -- reflects the last assignment, not this one!
3759 if Ekind (F) = E_Out_Parameter then
3760 if Warn_On_Modified_As_Out_Parameter (F)
3761 and then Is_Entity_Name (A)
3762 and then Present (Entity (A))
3763 and then Comes_From_Source (N)
3765 Warn_On_Useless_Assignment (Entity (A), A);
3769 -- Validate the form of the actual. Note that the call to
3770 -- Is_OK_Variable_For_Out_Formal generates the required
3771 -- reference in this case.
3773 -- A call to an initialization procedure for an aggregate
3774 -- component may initialize a nested component of a constant
3775 -- designated object. In this context the object is variable.
3777 if not Is_OK_Variable_For_Out_Formal (A)
3778 and then not Is_Init_Proc (Nam)
3780 Error_Msg_NE ("actual for& must be a variable", A, F);
3783 -- What's the following about???
3785 if Is_Entity_Name (A) then
3786 Kill_Checks (Entity (A));
3792 if Etype (A) = Any_Type then
3793 Set_Etype (N, Any_Type);
3797 -- Apply appropriate range checks for in, out, and in-out
3798 -- parameters. Out and in-out parameters also need a separate
3799 -- check, if there is a type conversion, to make sure the return
3800 -- value meets the constraints of the variable before the
3803 -- Gigi looks at the check flag and uses the appropriate types.
3804 -- For now since one flag is used there is an optimization which
3805 -- might not be done in the In Out case since Gigi does not do
3806 -- any analysis. More thought required about this ???
3808 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
3810 -- Apply predicate checks, unless this is a call to the
3811 -- predicate check function itself, which would cause an
3812 -- infinite recursion.
3814 if not (Ekind (Nam) = E_Function
3815 and then Has_Predicates (Nam))
3817 Apply_Predicate_Check (A, F_Typ);
3820 -- Apply required constraint checks
3822 if Is_Scalar_Type (Etype (A)) then
3823 Apply_Scalar_Range_Check (A, F_Typ);
3825 elsif Is_Array_Type (Etype (A)) then
3826 Apply_Length_Check (A, F_Typ);
3828 elsif Is_Record_Type (F_Typ)
3829 and then Has_Discriminants (F_Typ)
3830 and then Is_Constrained (F_Typ)
3831 and then (not Is_Derived_Type (F_Typ)
3832 or else Comes_From_Source (Nam))
3834 Apply_Discriminant_Check (A, F_Typ);
3836 elsif Is_Access_Type (F_Typ)
3837 and then Is_Array_Type (Designated_Type (F_Typ))
3838 and then Is_Constrained (Designated_Type (F_Typ))
3840 Apply_Length_Check (A, F_Typ);
3842 elsif Is_Access_Type (F_Typ)
3843 and then Has_Discriminants (Designated_Type (F_Typ))
3844 and then Is_Constrained (Designated_Type (F_Typ))
3846 Apply_Discriminant_Check (A, F_Typ);
3849 Apply_Range_Check (A, F_Typ);
3852 -- Ada 2005 (AI-231): Note that the controlling parameter case
3853 -- already existed in Ada 95, which is partially checked
3854 -- elsewhere (see Checks), and we don't want the warning
3855 -- message to differ.
3857 if Is_Access_Type (F_Typ)
3858 and then Can_Never_Be_Null (F_Typ)
3859 and then Known_Null (A)
3861 if Is_Controlling_Formal (F) then
3862 Apply_Compile_Time_Constraint_Error
3864 Msg => "null value not allowed here?",
3865 Reason => CE_Access_Check_Failed);
3867 elsif Ada_Version >= Ada_2005 then
3868 Apply_Compile_Time_Constraint_Error
3870 Msg => "(Ada 2005) null not allowed in "
3871 & "null-excluding formal?",
3872 Reason => CE_Null_Not_Allowed);
3877 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
3878 if Nkind (A) = N_Type_Conversion then
3879 if Is_Scalar_Type (A_Typ) then
3880 Apply_Scalar_Range_Check
3881 (Expression (A), Etype (Expression (A)), A_Typ);
3884 (Expression (A), Etype (Expression (A)), A_Typ);
3888 if Is_Scalar_Type (F_Typ) then
3889 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3890 elsif Is_Array_Type (F_Typ)
3891 and then Ekind (F) = E_Out_Parameter
3893 Apply_Length_Check (A, F_Typ);
3895 Apply_Range_Check (A, A_Typ, F_Typ);
3900 -- An actual associated with an access parameter is implicitly
3901 -- converted to the anonymous access type of the formal and must
3902 -- satisfy the legality checks for access conversions.
3904 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3905 if not Valid_Conversion (A, F_Typ, A) then
3907 ("invalid implicit conversion for access parameter", A);
3911 -- Check bad case of atomic/volatile argument (RM C.6(12))
3913 if Is_By_Reference_Type (Etype (F))
3914 and then Comes_From_Source (N)
3916 if Is_Atomic_Object (A)
3917 and then not Is_Atomic (Etype (F))
3920 ("cannot pass atomic argument to non-atomic formal",
3923 elsif Is_Volatile_Object (A)
3924 and then not Is_Volatile (Etype (F))
3927 ("cannot pass volatile argument to non-volatile formal",
3932 -- Check that subprograms don't have improper controlling
3933 -- arguments (RM 3.9.2 (9)).
3935 -- A primitive operation may have an access parameter of an
3936 -- incomplete tagged type, but a dispatching call is illegal
3937 -- if the type is still incomplete.
3939 if Is_Controlling_Formal (F) then
3940 Set_Is_Controlling_Actual (A);
3942 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3944 Desig : constant Entity_Id := Designated_Type (Etype (F));
3946 if Ekind (Desig) = E_Incomplete_Type
3947 and then No (Full_View (Desig))
3948 and then No (Non_Limited_View (Desig))
3951 ("premature use of incomplete type& " &
3952 "in dispatching call", A, Desig);
3957 elsif Nkind (A) = N_Explicit_Dereference then
3958 Validate_Remote_Access_To_Class_Wide_Type (A);
3961 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3962 and then not Is_Class_Wide_Type (F_Typ)
3963 and then not Is_Controlling_Formal (F)
3965 Error_Msg_N ("class-wide argument not allowed here!", A);
3967 if Is_Subprogram (Nam)
3968 and then Comes_From_Source (Nam)
3970 Error_Msg_Node_2 := F_Typ;
3972 ("& is not a dispatching operation of &!", A, Nam);
3975 -- Apply the checks described in 3.10.2(27): if the context is a
3976 -- specific access-to-object, the actual cannot be class-wide.
3977 -- Use base type to exclude access_to_subprogram cases.
3979 elsif Is_Access_Type (A_Typ)
3980 and then Is_Access_Type (F_Typ)
3981 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
3982 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3983 or else (Nkind (A) = N_Attribute_Reference
3985 Is_Class_Wide_Type (Etype (Prefix (A)))))
3986 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3987 and then not Is_Controlling_Formal (F)
3989 -- Disable these checks for call to imported C++ subprograms
3992 (Is_Entity_Name (Name (N))
3993 and then Is_Imported (Entity (Name (N)))
3994 and then Convention (Entity (Name (N))) = Convention_CPP)
3997 ("access to class-wide argument not allowed here!", A);
3999 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4000 Error_Msg_Node_2 := Designated_Type (F_Typ);
4002 ("& is not a dispatching operation of &!", A, Nam);
4008 -- If it is a named association, treat the selector_name as a
4009 -- proper identifier, and mark the corresponding entity. Ignore
4010 -- this reference in Alfa mode, as it refers to an entity not in
4011 -- scope at the point of reference, so the reference should be
4012 -- ignored for computing effects of subprograms.
4014 if Nkind (Parent (A)) = N_Parameter_Association
4015 and then not Alfa_Mode
4017 Set_Entity (Selector_Name (Parent (A)), F);
4018 Generate_Reference (F, Selector_Name (Parent (A)));
4019 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4020 Generate_Reference (F_Typ, N, ' ');
4025 if Ekind (F) /= E_Out_Parameter then
4026 Check_Unset_Reference (A);
4031 -- Case where actual is not present
4039 end Resolve_Actuals;
4041 -----------------------
4042 -- Resolve_Allocator --
4043 -----------------------
4045 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4046 Desig_T : constant Entity_Id := Designated_Type (Typ);
4047 E : constant Node_Id := Expression (N);
4049 Discrim : Entity_Id;
4052 Assoc : Node_Id := Empty;
4055 procedure Check_Allocator_Discrim_Accessibility
4056 (Disc_Exp : Node_Id;
4057 Alloc_Typ : Entity_Id);
4058 -- Check that accessibility level associated with an access discriminant
4059 -- initialized in an allocator by the expression Disc_Exp is not deeper
4060 -- than the level of the allocator type Alloc_Typ. An error message is
4061 -- issued if this condition is violated. Specialized checks are done for
4062 -- the cases of a constraint expression which is an access attribute or
4063 -- an access discriminant.
4065 function In_Dispatching_Context return Boolean;
4066 -- If the allocator is an actual in a call, it is allowed to be class-
4067 -- wide when the context is not because it is a controlling actual.
4069 -------------------------------------------
4070 -- Check_Allocator_Discrim_Accessibility --
4071 -------------------------------------------
4073 procedure Check_Allocator_Discrim_Accessibility
4074 (Disc_Exp : Node_Id;
4075 Alloc_Typ : Entity_Id)
4078 if Type_Access_Level (Etype (Disc_Exp)) >
4079 Type_Access_Level (Alloc_Typ)
4082 ("operand type has deeper level than allocator type", Disc_Exp);
4084 -- When the expression is an Access attribute the level of the prefix
4085 -- object must not be deeper than that of the allocator's type.
4087 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4088 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
4090 and then Object_Access_Level (Prefix (Disc_Exp))
4091 > Type_Access_Level (Alloc_Typ)
4094 ("prefix of attribute has deeper level than allocator type",
4097 -- When the expression is an access discriminant the check is against
4098 -- the level of the prefix object.
4100 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4101 and then Nkind (Disc_Exp) = N_Selected_Component
4102 and then Object_Access_Level (Prefix (Disc_Exp))
4103 > Type_Access_Level (Alloc_Typ)
4106 ("access discriminant has deeper level than allocator type",
4109 -- All other cases are legal
4114 end Check_Allocator_Discrim_Accessibility;
4116 ----------------------------
4117 -- In_Dispatching_Context --
4118 ----------------------------
4120 function In_Dispatching_Context return Boolean is
4121 Par : constant Node_Id := Parent (N);
4125 Nkind_In (Par, N_Function_Call,
4126 N_Procedure_Call_Statement)
4127 and then Is_Entity_Name (Name (Par))
4128 and then Is_Dispatching_Operation (Entity (Name (Par)));
4129 end In_Dispatching_Context;
4131 -- Start of processing for Resolve_Allocator
4134 -- Replace general access with specific type
4136 if Ekind (Etype (N)) = E_Allocator_Type then
4137 Set_Etype (N, Base_Type (Typ));
4140 if Is_Abstract_Type (Typ) then
4141 Error_Msg_N ("type of allocator cannot be abstract", N);
4144 -- For qualified expression, resolve the expression using the
4145 -- given subtype (nothing to do for type mark, subtype indication)
4147 if Nkind (E) = N_Qualified_Expression then
4148 if Is_Class_Wide_Type (Etype (E))
4149 and then not Is_Class_Wide_Type (Desig_T)
4150 and then not In_Dispatching_Context
4153 ("class-wide allocator not allowed for this access type", N);
4156 Resolve (Expression (E), Etype (E));
4157 Check_Unset_Reference (Expression (E));
4159 -- A qualified expression requires an exact match of the type,
4160 -- class-wide matching is not allowed.
4162 if (Is_Class_Wide_Type (Etype (Expression (E)))
4163 or else Is_Class_Wide_Type (Etype (E)))
4164 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4166 Wrong_Type (Expression (E), Etype (E));
4169 -- A special accessibility check is needed for allocators that
4170 -- constrain access discriminants. The level of the type of the
4171 -- expression used to constrain an access discriminant cannot be
4172 -- deeper than the type of the allocator (in contrast to access
4173 -- parameters, where the level of the actual can be arbitrary).
4175 -- We can't use Valid_Conversion to perform this check because
4176 -- in general the type of the allocator is unrelated to the type
4177 -- of the access discriminant.
4179 if Ekind (Typ) /= E_Anonymous_Access_Type
4180 or else Is_Local_Anonymous_Access (Typ)
4182 Subtyp := Entity (Subtype_Mark (E));
4184 Aggr := Original_Node (Expression (E));
4186 if Has_Discriminants (Subtyp)
4187 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4189 Discrim := First_Discriminant (Base_Type (Subtyp));
4191 -- Get the first component expression of the aggregate
4193 if Present (Expressions (Aggr)) then
4194 Disc_Exp := First (Expressions (Aggr));
4196 elsif Present (Component_Associations (Aggr)) then
4197 Assoc := First (Component_Associations (Aggr));
4199 if Present (Assoc) then
4200 Disc_Exp := Expression (Assoc);
4209 while Present (Discrim) and then Present (Disc_Exp) loop
4210 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4211 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4214 Next_Discriminant (Discrim);
4216 if Present (Discrim) then
4217 if Present (Assoc) then
4219 Disc_Exp := Expression (Assoc);
4221 elsif Present (Next (Disc_Exp)) then
4225 Assoc := First (Component_Associations (Aggr));
4227 if Present (Assoc) then
4228 Disc_Exp := Expression (Assoc);
4238 -- For a subtype mark or subtype indication, freeze the subtype
4241 Freeze_Expression (E);
4243 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4245 ("initialization required for access-to-constant allocator", N);
4248 -- A special accessibility check is needed for allocators that
4249 -- constrain access discriminants. The level of the type of the
4250 -- expression used to constrain an access discriminant cannot be
4251 -- deeper than the type of the allocator (in contrast to access
4252 -- parameters, where the level of the actual can be arbitrary).
4253 -- We can't use Valid_Conversion to perform this check because
4254 -- in general the type of the allocator is unrelated to the type
4255 -- of the access discriminant.
4257 if Nkind (Original_Node (E)) = N_Subtype_Indication
4258 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4259 or else Is_Local_Anonymous_Access (Typ))
4261 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4263 if Has_Discriminants (Subtyp) then
4264 Discrim := First_Discriminant (Base_Type (Subtyp));
4265 Constr := First (Constraints (Constraint (Original_Node (E))));
4266 while Present (Discrim) and then Present (Constr) loop
4267 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4268 if Nkind (Constr) = N_Discriminant_Association then
4269 Disc_Exp := Original_Node (Expression (Constr));
4271 Disc_Exp := Original_Node (Constr);
4274 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4277 Next_Discriminant (Discrim);
4284 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4285 -- check that the level of the type of the created object is not deeper
4286 -- than the level of the allocator's access type, since extensions can
4287 -- now occur at deeper levels than their ancestor types. This is a
4288 -- static accessibility level check; a run-time check is also needed in
4289 -- the case of an initialized allocator with a class-wide argument (see
4290 -- Expand_Allocator_Expression).
4292 if Ada_Version >= Ada_2005
4293 and then Is_Class_Wide_Type (Desig_T)
4296 Exp_Typ : Entity_Id;
4299 if Nkind (E) = N_Qualified_Expression then
4300 Exp_Typ := Etype (E);
4301 elsif Nkind (E) = N_Subtype_Indication then
4302 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4304 Exp_Typ := Entity (E);
4307 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4308 if In_Instance_Body then
4309 Error_Msg_N ("?type in allocator has deeper level than" &
4310 " designated class-wide type", E);
4311 Error_Msg_N ("\?Program_Error will be raised at run time",
4314 Make_Raise_Program_Error (Sloc (N),
4315 Reason => PE_Accessibility_Check_Failed));
4318 -- Do not apply Ada 2005 accessibility checks on a class-wide
4319 -- allocator if the type given in the allocator is a formal
4320 -- type. A run-time check will be performed in the instance.
4322 elsif not Is_Generic_Type (Exp_Typ) then
4323 Error_Msg_N ("type in allocator has deeper level than" &
4324 " designated class-wide type", E);
4330 -- Check for allocation from an empty storage pool
4332 if No_Pool_Assigned (Typ) then
4333 Error_Msg_N ("allocation from empty storage pool!", N);
4335 -- If the context is an unchecked conversion, as may happen within an
4336 -- inlined subprogram, the allocator is being resolved with its own
4337 -- anonymous type. In that case, if the target type has a specific
4338 -- storage pool, it must be inherited explicitly by the allocator type.
4340 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4341 and then No (Associated_Storage_Pool (Typ))
4343 Set_Associated_Storage_Pool
4344 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4347 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4348 Check_Restriction (No_Anonymous_Allocators, N);
4351 -- Check that an allocator with task parts isn't for a nested access
4352 -- type when restriction No_Task_Hierarchy applies.
4354 if not Is_Library_Level_Entity (Base_Type (Typ))
4355 and then Has_Task (Base_Type (Desig_T))
4357 Check_Restriction (No_Task_Hierarchy, N);
4360 -- An erroneous allocator may be rewritten as a raise Program_Error
4363 if Nkind (N) = N_Allocator then
4365 -- An anonymous access discriminant is the definition of a
4368 if Ekind (Typ) = E_Anonymous_Access_Type
4369 and then Nkind (Associated_Node_For_Itype (Typ)) =
4370 N_Discriminant_Specification
4373 Discr : constant Entity_Id :=
4374 Defining_Identifier (Associated_Node_For_Itype (Typ));
4377 -- Ada 2012 AI05-0052: If the designated type of the allocator
4378 -- is limited, then the allocator shall not be used to define
4379 -- the value of an access discriminant unless the discriminated
4380 -- type is immutably limited.
4382 if Ada_Version >= Ada_2012
4383 and then Is_Limited_Type (Desig_T)
4384 and then not Is_Immutably_Limited_Type (Scope (Discr))
4387 ("only immutably limited types can have anonymous "
4388 & "access discriminants designating a limited type", N);
4392 -- Avoid marking an allocator as a dynamic coextension if it is
4393 -- within a static construct.
4395 if not Is_Static_Coextension (N) then
4396 Set_Is_Dynamic_Coextension (N);
4399 -- Cleanup for potential static coextensions
4402 Set_Is_Dynamic_Coextension (N, False);
4403 Set_Is_Static_Coextension (N, False);
4407 -- Report a simple error: if the designated object is a local task,
4408 -- its body has not been seen yet, and its activation will fail an
4409 -- elaboration check.
4411 if Is_Task_Type (Desig_T)
4412 and then Scope (Base_Type (Desig_T)) = Current_Scope
4413 and then Is_Compilation_Unit (Current_Scope)
4414 and then Ekind (Current_Scope) = E_Package
4415 and then not In_Package_Body (Current_Scope)
4417 Error_Msg_N ("cannot activate task before body seen?", N);
4418 Error_Msg_N ("\Program_Error will be raised at run time?", N);
4421 -- Ada 2012 (AI05-0111-3): Issue a warning whenever allocating a task
4422 -- or a type containing tasks on a subpool since the deallocation of
4423 -- the subpool may lead to undefined task behavior. Perform the check
4424 -- only when the allocator has not been converted into a Program_Error
4425 -- due to a previous error.
4427 if Ada_Version >= Ada_2012
4428 and then Nkind (N) = N_Allocator
4429 and then Present (Subpool_Handle_Name (N))
4430 and then Has_Task (Desig_T)
4432 Error_Msg_N ("?allocation of task on subpool may lead to " &
4433 "undefined behavior", N);
4435 end Resolve_Allocator;
4437 ---------------------------
4438 -- Resolve_Arithmetic_Op --
4439 ---------------------------
4441 -- Used for resolving all arithmetic operators except exponentiation
4443 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4444 L : constant Node_Id := Left_Opnd (N);
4445 R : constant Node_Id := Right_Opnd (N);
4446 TL : constant Entity_Id := Base_Type (Etype (L));
4447 TR : constant Entity_Id := Base_Type (Etype (R));
4451 B_Typ : constant Entity_Id := Base_Type (Typ);
4452 -- We do the resolution using the base type, because intermediate values
4453 -- in expressions always are of the base type, not a subtype of it.
4455 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4456 -- Returns True if N is in a context that expects "any real type"
4458 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4459 -- Return True iff given type is Integer or universal real/integer
4461 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4462 -- Choose type of integer literal in fixed-point operation to conform
4463 -- to available fixed-point type. T is the type of the other operand,
4464 -- which is needed to determine the expected type of N.
4466 procedure Set_Operand_Type (N : Node_Id);
4467 -- Set operand type to T if universal
4469 -------------------------------
4470 -- Expected_Type_Is_Any_Real --
4471 -------------------------------
4473 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4475 -- N is the expression after "delta" in a fixed_point_definition;
4478 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4479 N_Decimal_Fixed_Point_Definition,
4481 -- N is one of the bounds in a real_range_specification;
4484 N_Real_Range_Specification,
4486 -- N is the expression of a delta_constraint;
4489 N_Delta_Constraint);
4490 end Expected_Type_Is_Any_Real;
4492 -----------------------------
4493 -- Is_Integer_Or_Universal --
4494 -----------------------------
4496 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4498 Index : Interp_Index;
4502 if not Is_Overloaded (N) then
4504 return Base_Type (T) = Base_Type (Standard_Integer)
4505 or else T = Universal_Integer
4506 or else T = Universal_Real;
4508 Get_First_Interp (N, Index, It);
4509 while Present (It.Typ) loop
4510 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4511 or else It.Typ = Universal_Integer
4512 or else It.Typ = Universal_Real
4517 Get_Next_Interp (Index, It);
4522 end Is_Integer_Or_Universal;
4524 ----------------------------
4525 -- Set_Mixed_Mode_Operand --
4526 ----------------------------
4528 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4529 Index : Interp_Index;
4533 if Universal_Interpretation (N) = Universal_Integer then
4535 -- A universal integer literal is resolved as standard integer
4536 -- except in the case of a fixed-point result, where we leave it
4537 -- as universal (to be handled by Exp_Fixd later on)
4539 if Is_Fixed_Point_Type (T) then
4540 Resolve (N, Universal_Integer);
4542 Resolve (N, Standard_Integer);
4545 elsif Universal_Interpretation (N) = Universal_Real
4546 and then (T = Base_Type (Standard_Integer)
4547 or else T = Universal_Integer
4548 or else T = Universal_Real)
4550 -- A universal real can appear in a fixed-type context. We resolve
4551 -- the literal with that context, even though this might raise an
4552 -- exception prematurely (the other operand may be zero).
4556 elsif Etype (N) = Base_Type (Standard_Integer)
4557 and then T = Universal_Real
4558 and then Is_Overloaded (N)
4560 -- Integer arg in mixed-mode operation. Resolve with universal
4561 -- type, in case preference rule must be applied.
4563 Resolve (N, Universal_Integer);
4566 and then B_Typ /= Universal_Fixed
4568 -- Not a mixed-mode operation, resolve with context
4572 elsif Etype (N) = Any_Fixed then
4574 -- N may itself be a mixed-mode operation, so use context type
4578 elsif Is_Fixed_Point_Type (T)
4579 and then B_Typ = Universal_Fixed
4580 and then Is_Overloaded (N)
4582 -- Must be (fixed * fixed) operation, operand must have one
4583 -- compatible interpretation.
4585 Resolve (N, Any_Fixed);
4587 elsif Is_Fixed_Point_Type (B_Typ)
4588 and then (T = Universal_Real
4589 or else Is_Fixed_Point_Type (T))
4590 and then Is_Overloaded (N)
4592 -- C * F(X) in a fixed context, where C is a real literal or a
4593 -- fixed-point expression. F must have either a fixed type
4594 -- interpretation or an integer interpretation, but not both.
4596 Get_First_Interp (N, Index, It);
4597 while Present (It.Typ) loop
4598 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4599 if Analyzed (N) then
4600 Error_Msg_N ("ambiguous operand in fixed operation", N);
4602 Resolve (N, Standard_Integer);
4605 elsif Is_Fixed_Point_Type (It.Typ) then
4606 if Analyzed (N) then
4607 Error_Msg_N ("ambiguous operand in fixed operation", N);
4609 Resolve (N, It.Typ);
4613 Get_Next_Interp (Index, It);
4616 -- Reanalyze the literal with the fixed type of the context. If
4617 -- context is Universal_Fixed, we are within a conversion, leave
4618 -- the literal as a universal real because there is no usable
4619 -- fixed type, and the target of the conversion plays no role in
4633 if B_Typ = Universal_Fixed
4634 and then Nkind (Op2) = N_Real_Literal
4636 T2 := Universal_Real;
4641 Set_Analyzed (Op2, False);
4648 end Set_Mixed_Mode_Operand;
4650 ----------------------
4651 -- Set_Operand_Type --
4652 ----------------------
4654 procedure Set_Operand_Type (N : Node_Id) is
4656 if Etype (N) = Universal_Integer
4657 or else Etype (N) = Universal_Real
4661 end Set_Operand_Type;
4663 -- Start of processing for Resolve_Arithmetic_Op
4666 if Comes_From_Source (N)
4667 and then Ekind (Entity (N)) = E_Function
4668 and then Is_Imported (Entity (N))
4669 and then Is_Intrinsic_Subprogram (Entity (N))
4671 Resolve_Intrinsic_Operator (N, Typ);
4674 -- Special-case for mixed-mode universal expressions or fixed point type
4675 -- operation: each argument is resolved separately. The same treatment
4676 -- is required if one of the operands of a fixed point operation is
4677 -- universal real, since in this case we don't do a conversion to a
4678 -- specific fixed-point type (instead the expander handles the case).
4680 -- Set the type of the node to its universal interpretation because
4681 -- legality checks on an exponentiation operand need the context.
4683 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4684 and then Present (Universal_Interpretation (L))
4685 and then Present (Universal_Interpretation (R))
4687 Set_Etype (N, B_Typ);
4688 Resolve (L, Universal_Interpretation (L));
4689 Resolve (R, Universal_Interpretation (R));
4691 elsif (B_Typ = Universal_Real
4692 or else Etype (N) = Universal_Fixed
4693 or else (Etype (N) = Any_Fixed
4694 and then Is_Fixed_Point_Type (B_Typ))
4695 or else (Is_Fixed_Point_Type (B_Typ)
4696 and then (Is_Integer_Or_Universal (L)
4698 Is_Integer_Or_Universal (R))))
4699 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4701 if TL = Universal_Integer or else TR = Universal_Integer then
4702 Check_For_Visible_Operator (N, B_Typ);
4705 -- If context is a fixed type and one operand is integer, the other
4706 -- is resolved with the type of the context.
4708 if Is_Fixed_Point_Type (B_Typ)
4709 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4710 or else TL = Universal_Integer)
4715 elsif Is_Fixed_Point_Type (B_Typ)
4716 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4717 or else TR = Universal_Integer)
4723 Set_Mixed_Mode_Operand (L, TR);
4724 Set_Mixed_Mode_Operand (R, TL);
4727 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4728 -- multiplying operators from being used when the expected type is
4729 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4730 -- some cases where the expected type is actually Any_Real;
4731 -- Expected_Type_Is_Any_Real takes care of that case.
4733 if Etype (N) = Universal_Fixed
4734 or else Etype (N) = Any_Fixed
4736 if B_Typ = Universal_Fixed
4737 and then not Expected_Type_Is_Any_Real (N)
4738 and then not Nkind_In (Parent (N), N_Type_Conversion,
4739 N_Unchecked_Type_Conversion)
4741 Error_Msg_N ("type cannot be determined from context!", N);
4742 Error_Msg_N ("\explicit conversion to result type required", N);
4744 Set_Etype (L, Any_Type);
4745 Set_Etype (R, Any_Type);
4748 if Ada_Version = Ada_83
4749 and then Etype (N) = Universal_Fixed
4751 Nkind_In (Parent (N), N_Type_Conversion,
4752 N_Unchecked_Type_Conversion)
4755 ("(Ada 83) fixed-point operation "
4756 & "needs explicit conversion", N);
4759 -- The expected type is "any real type" in contexts like
4761 -- type T is delta <universal_fixed-expression> ...
4763 -- in which case we need to set the type to Universal_Real
4764 -- so that static expression evaluation will work properly.
4766 if Expected_Type_Is_Any_Real (N) then
4767 Set_Etype (N, Universal_Real);
4769 Set_Etype (N, B_Typ);
4773 elsif Is_Fixed_Point_Type (B_Typ)
4774 and then (Is_Integer_Or_Universal (L)
4775 or else Nkind (L) = N_Real_Literal
4776 or else Nkind (R) = N_Real_Literal
4777 or else Is_Integer_Or_Universal (R))
4779 Set_Etype (N, B_Typ);
4781 elsif Etype (N) = Any_Fixed then
4783 -- If no previous errors, this is only possible if one operand is
4784 -- overloaded and the context is universal. Resolve as such.
4786 Set_Etype (N, B_Typ);
4790 if (TL = Universal_Integer or else TL = Universal_Real)
4792 (TR = Universal_Integer or else TR = Universal_Real)
4794 Check_For_Visible_Operator (N, B_Typ);
4797 -- If the context is Universal_Fixed and the operands are also
4798 -- universal fixed, this is an error, unless there is only one
4799 -- applicable fixed_point type (usually Duration).
4801 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4802 T := Unique_Fixed_Point_Type (N);
4804 if T = Any_Type then
4817 -- If one of the arguments was resolved to a non-universal type.
4818 -- label the result of the operation itself with the same type.
4819 -- Do the same for the universal argument, if any.
4821 T := Intersect_Types (L, R);
4822 Set_Etype (N, Base_Type (T));
4823 Set_Operand_Type (L);
4824 Set_Operand_Type (R);
4827 Generate_Operator_Reference (N, Typ);
4828 Eval_Arithmetic_Op (N);
4830 -- In SPARK, a multiplication or division with operands of fixed point
4831 -- types shall be qualified or explicitly converted to identify the
4834 if (Is_Fixed_Point_Type (Etype (L))
4835 or else Is_Fixed_Point_Type (Etype (R)))
4836 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4838 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
4840 Check_SPARK_Restriction
4841 ("operation should be qualified or explicitly converted", N);
4844 -- Set overflow and division checking bit. Much cleverer code needed
4845 -- here eventually and perhaps the Resolve routines should be separated
4846 -- for the various arithmetic operations, since they will need
4847 -- different processing. ???
4849 if Nkind (N) in N_Op then
4850 if not Overflow_Checks_Suppressed (Etype (N)) then
4851 Enable_Overflow_Check (N);
4854 -- Give warning if explicit division by zero
4856 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4857 and then not Division_Checks_Suppressed (Etype (N))
4859 Rop := Right_Opnd (N);
4861 if Compile_Time_Known_Value (Rop)
4862 and then ((Is_Integer_Type (Etype (Rop))
4863 and then Expr_Value (Rop) = Uint_0)
4865 (Is_Real_Type (Etype (Rop))
4866 and then Expr_Value_R (Rop) = Ureal_0))
4868 -- Specialize the warning message according to the operation
4872 Apply_Compile_Time_Constraint_Error
4873 (N, "division by zero?", CE_Divide_By_Zero,
4874 Loc => Sloc (Right_Opnd (N)));
4877 Apply_Compile_Time_Constraint_Error
4878 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4879 Loc => Sloc (Right_Opnd (N)));
4882 Apply_Compile_Time_Constraint_Error
4883 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4884 Loc => Sloc (Right_Opnd (N)));
4886 -- Division by zero can only happen with division, rem,
4887 -- and mod operations.
4890 raise Program_Error;
4893 -- Otherwise just set the flag to check at run time
4896 Activate_Division_Check (N);
4900 -- If Restriction No_Implicit_Conditionals is active, then it is
4901 -- violated if either operand can be negative for mod, or for rem
4902 -- if both operands can be negative.
4904 if Restriction_Check_Required (No_Implicit_Conditionals)
4905 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4914 -- Set if corresponding operand might be negative
4918 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4919 LNeg := (not OK) or else Lo < 0;
4922 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4923 RNeg := (not OK) or else Lo < 0;
4925 -- Check if we will be generating conditionals. There are two
4926 -- cases where that can happen, first for REM, the only case
4927 -- is largest negative integer mod -1, where the division can
4928 -- overflow, but we still have to give the right result. The
4929 -- front end generates a test for this annoying case. Here we
4930 -- just test if both operands can be negative (that's what the
4931 -- expander does, so we match its logic here).
4933 -- The second case is mod where either operand can be negative.
4934 -- In this case, the back end has to generate additional tests.
4936 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4938 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4940 Check_Restriction (No_Implicit_Conditionals, N);
4946 Check_Unset_Reference (L);
4947 Check_Unset_Reference (R);
4948 end Resolve_Arithmetic_Op;
4954 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4955 Loc : constant Source_Ptr := Sloc (N);
4956 Subp : constant Node_Id := Name (N);
4964 function Same_Or_Aliased_Subprograms
4966 E : Entity_Id) return Boolean;
4967 -- Returns True if the subprogram entity S is the same as E or else
4968 -- S is an alias of E.
4970 ---------------------------------
4971 -- Same_Or_Aliased_Subprograms --
4972 ---------------------------------
4974 function Same_Or_Aliased_Subprograms
4976 E : Entity_Id) return Boolean
4978 Subp_Alias : constant Entity_Id := Alias (S);
4981 or else (Present (Subp_Alias) and then Subp_Alias = E);
4982 end Same_Or_Aliased_Subprograms;
4984 -- Start of processing for Resolve_Call
4987 -- The context imposes a unique interpretation with type Typ on a
4988 -- procedure or function call. Find the entity of the subprogram that
4989 -- yields the expected type, and propagate the corresponding formal
4990 -- constraints on the actuals. The caller has established that an
4991 -- interpretation exists, and emitted an error if not unique.
4993 -- First deal with the case of a call to an access-to-subprogram,
4994 -- dereference made explicit in Analyze_Call.
4996 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4997 if not Is_Overloaded (Subp) then
4998 Nam := Etype (Subp);
5001 -- Find the interpretation whose type (a subprogram type) has a
5002 -- return type that is compatible with the context. Analysis of
5003 -- the node has established that one exists.
5007 Get_First_Interp (Subp, I, It);
5008 while Present (It.Typ) loop
5009 if Covers (Typ, Etype (It.Typ)) then
5014 Get_Next_Interp (I, It);
5018 raise Program_Error;
5022 -- If the prefix is not an entity, then resolve it
5024 if not Is_Entity_Name (Subp) then
5025 Resolve (Subp, Nam);
5028 -- For an indirect call, we always invalidate checks, since we do not
5029 -- know whether the subprogram is local or global. Yes we could do
5030 -- better here, e.g. by knowing that there are no local subprograms,
5031 -- but it does not seem worth the effort. Similarly, we kill all
5032 -- knowledge of current constant values.
5034 Kill_Current_Values;
5036 -- If this is a procedure call which is really an entry call, do
5037 -- the conversion of the procedure call to an entry call. Protected
5038 -- operations use the same circuitry because the name in the call
5039 -- can be an arbitrary expression with special resolution rules.
5041 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5042 or else (Is_Entity_Name (Subp)
5043 and then Ekind (Entity (Subp)) = E_Entry)
5045 Resolve_Entry_Call (N, Typ);
5046 Check_Elab_Call (N);
5048 -- Kill checks and constant values, as above for indirect case
5049 -- Who knows what happens when another task is activated?
5051 Kill_Current_Values;
5054 -- Normal subprogram call with name established in Resolve
5056 elsif not (Is_Type (Entity (Subp))) then
5057 Nam := Entity (Subp);
5058 Set_Entity_With_Style_Check (Subp, Nam);
5060 -- Otherwise we must have the case of an overloaded call
5063 pragma Assert (Is_Overloaded (Subp));
5065 -- Initialize Nam to prevent warning (we know it will be assigned
5066 -- in the loop below, but the compiler does not know that).
5070 Get_First_Interp (Subp, I, It);
5071 while Present (It.Typ) loop
5072 if Covers (Typ, It.Typ) then
5074 Set_Entity_With_Style_Check (Subp, Nam);
5078 Get_Next_Interp (I, It);
5082 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5083 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5084 and then Nkind (Subp) /= N_Explicit_Dereference
5085 and then Present (Parameter_Associations (N))
5087 -- The prefix is a parameterless function call that returns an access
5088 -- to subprogram. If parameters are present in the current call, add
5089 -- add an explicit dereference. We use the base type here because
5090 -- within an instance these may be subtypes.
5092 -- The dereference is added either in Analyze_Call or here. Should
5093 -- be consolidated ???
5095 Set_Is_Overloaded (Subp, False);
5096 Set_Etype (Subp, Etype (Nam));
5097 Insert_Explicit_Dereference (Subp);
5098 Nam := Designated_Type (Etype (Nam));
5099 Resolve (Subp, Nam);
5102 -- Check that a call to Current_Task does not occur in an entry body
5104 if Is_RTE (Nam, RE_Current_Task) then
5113 -- Exclude calls that occur within the default of a formal
5114 -- parameter of the entry, since those are evaluated outside
5117 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5119 if Nkind (P) = N_Entry_Body
5120 or else (Nkind (P) = N_Subprogram_Body
5121 and then Is_Entry_Barrier_Function (P))
5125 ("?& should not be used in entry body (RM C.7(17))",
5128 ("\Program_Error will be raised at run time?", N, Nam);
5130 Make_Raise_Program_Error (Loc,
5131 Reason => PE_Current_Task_In_Entry_Body));
5132 Set_Etype (N, Rtype);
5139 -- Check that a procedure call does not occur in the context of the
5140 -- entry call statement of a conditional or timed entry call. Note that
5141 -- the case of a call to a subprogram renaming of an entry will also be
5142 -- rejected. The test for N not being an N_Entry_Call_Statement is
5143 -- defensive, covering the possibility that the processing of entry
5144 -- calls might reach this point due to later modifications of the code
5147 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5148 and then Nkind (N) /= N_Entry_Call_Statement
5149 and then Entry_Call_Statement (Parent (N)) = N
5151 if Ada_Version < Ada_2005 then
5152 Error_Msg_N ("entry call required in select statement", N);
5154 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5155 -- for a procedure_or_entry_call, the procedure_name or
5156 -- procedure_prefix of the procedure_call_statement shall denote
5157 -- an entry renamed by a procedure, or (a view of) a primitive
5158 -- subprogram of a limited interface whose first parameter is
5159 -- a controlling parameter.
5161 elsif Nkind (N) = N_Procedure_Call_Statement
5162 and then not Is_Renamed_Entry (Nam)
5163 and then not Is_Controlling_Limited_Procedure (Nam)
5166 ("entry call or dispatching primitive of interface required", N);
5170 -- Check that this is not a call to a protected procedure or entry from
5171 -- within a protected function.
5173 if Ekind (Current_Scope) = E_Function
5174 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
5175 and then Ekind (Nam) /= E_Function
5176 and then Scope (Nam) = Scope (Current_Scope)
5178 Error_Msg_N ("within protected function, protected " &
5179 "object is constant", N);
5180 Error_Msg_N ("\cannot call operation that may modify it", N);
5183 -- Freeze the subprogram name if not in a spec-expression. Note that we
5184 -- freeze procedure calls as well as function calls. Procedure calls are
5185 -- not frozen according to the rules (RM 13.14(14)) because it is
5186 -- impossible to have a procedure call to a non-frozen procedure in pure
5187 -- Ada, but in the code that we generate in the expander, this rule
5188 -- needs extending because we can generate procedure calls that need
5191 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
5192 Freeze_Expression (Subp);
5195 -- For a predefined operator, the type of the result is the type imposed
5196 -- by context, except for a predefined operation on universal fixed.
5197 -- Otherwise The type of the call is the type returned by the subprogram
5200 if Is_Predefined_Op (Nam) then
5201 if Etype (N) /= Universal_Fixed then
5205 -- If the subprogram returns an array type, and the context requires the
5206 -- component type of that array type, the node is really an indexing of
5207 -- the parameterless call. Resolve as such. A pathological case occurs
5208 -- when the type of the component is an access to the array type. In
5209 -- this case the call is truly ambiguous.
5211 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5213 ((Is_Array_Type (Etype (Nam))
5214 and then Covers (Typ, Component_Type (Etype (Nam))))
5215 or else (Is_Access_Type (Etype (Nam))
5216 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5220 Component_Type (Designated_Type (Etype (Nam))))))
5223 Index_Node : Node_Id;
5225 Ret_Type : constant Entity_Id := Etype (Nam);
5228 if Is_Access_Type (Ret_Type)
5229 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5232 ("cannot disambiguate function call and indexing", N);
5234 New_Subp := Relocate_Node (Subp);
5235 Set_Entity (Subp, Nam);
5237 if (Is_Array_Type (Ret_Type)
5238 and then Component_Type (Ret_Type) /= Any_Type)
5240 (Is_Access_Type (Ret_Type)
5242 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5244 if Needs_No_Actuals (Nam) then
5246 -- Indexed call to a parameterless function
5249 Make_Indexed_Component (Loc,
5251 Make_Function_Call (Loc,
5253 Expressions => Parameter_Associations (N));
5255 -- An Ada 2005 prefixed call to a primitive operation
5256 -- whose first parameter is the prefix. This prefix was
5257 -- prepended to the parameter list, which is actually a
5258 -- list of indexes. Remove the prefix in order to build
5259 -- the proper indexed component.
5262 Make_Indexed_Component (Loc,
5264 Make_Function_Call (Loc,
5266 Parameter_Associations =>
5268 (Remove_Head (Parameter_Associations (N)))),
5269 Expressions => Parameter_Associations (N));
5272 -- Preserve the parenthesis count of the node
5274 Set_Paren_Count (Index_Node, Paren_Count (N));
5276 -- Since we are correcting a node classification error made
5277 -- by the parser, we call Replace rather than Rewrite.
5279 Replace (N, Index_Node);
5281 Set_Etype (Prefix (N), Ret_Type);
5283 Resolve_Indexed_Component (N, Typ);
5284 Check_Elab_Call (Prefix (N));
5292 Set_Etype (N, Etype (Nam));
5295 -- In the case where the call is to an overloaded subprogram, Analyze
5296 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5297 -- such a case Normalize_Actuals needs to be called once more to order
5298 -- the actuals correctly. Otherwise the call will have the ordering
5299 -- given by the last overloaded subprogram whether this is the correct
5300 -- one being called or not.
5302 if Is_Overloaded (Subp) then
5303 Normalize_Actuals (N, Nam, False, Norm_OK);
5304 pragma Assert (Norm_OK);
5307 -- In any case, call is fully resolved now. Reset Overload flag, to
5308 -- prevent subsequent overload resolution if node is analyzed again
5310 Set_Is_Overloaded (Subp, False);
5311 Set_Is_Overloaded (N, False);
5313 -- If we are calling the current subprogram from immediately within its
5314 -- body, then that is the case where we can sometimes detect cases of
5315 -- infinite recursion statically. Do not try this in case restriction
5316 -- No_Recursion is in effect anyway, and do it only for source calls.
5318 if Comes_From_Source (N) then
5319 Scop := Current_Scope;
5321 -- Issue warning for possible infinite recursion in the absence
5322 -- of the No_Recursion restriction.
5324 if Same_Or_Aliased_Subprograms (Nam, Scop)
5325 and then not Restriction_Active (No_Recursion)
5326 and then Check_Infinite_Recursion (N)
5328 -- Here we detected and flagged an infinite recursion, so we do
5329 -- not need to test the case below for further warnings. Also we
5330 -- are all done if we now have a raise SE node.
5332 if Nkind (N) = N_Raise_Storage_Error then
5336 -- If call is to immediately containing subprogram, then check for
5337 -- the case of a possible run-time detectable infinite recursion.
5340 Scope_Loop : while Scop /= Standard_Standard loop
5341 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5343 -- Although in general case, recursion is not statically
5344 -- checkable, the case of calling an immediately containing
5345 -- subprogram is easy to catch.
5347 Check_Restriction (No_Recursion, N);
5349 -- If the recursive call is to a parameterless subprogram,
5350 -- then even if we can't statically detect infinite
5351 -- recursion, this is pretty suspicious, and we output a
5352 -- warning. Furthermore, we will try later to detect some
5353 -- cases here at run time by expanding checking code (see
5354 -- Detect_Infinite_Recursion in package Exp_Ch6).
5356 -- If the recursive call is within a handler, do not emit a
5357 -- warning, because this is a common idiom: loop until input
5358 -- is correct, catch illegal input in handler and restart.
5360 if No (First_Formal (Nam))
5361 and then Etype (Nam) = Standard_Void_Type
5362 and then not Error_Posted (N)
5363 and then Nkind (Parent (N)) /= N_Exception_Handler
5365 -- For the case of a procedure call. We give the message
5366 -- only if the call is the first statement in a sequence
5367 -- of statements, or if all previous statements are
5368 -- simple assignments. This is simply a heuristic to
5369 -- decrease false positives, without losing too many good
5370 -- warnings. The idea is that these previous statements
5371 -- may affect global variables the procedure depends on.
5372 -- We also exclude raise statements, that may arise from
5373 -- constraint checks and are probably unrelated to the
5374 -- intended control flow.
5376 if Nkind (N) = N_Procedure_Call_Statement
5377 and then Is_List_Member (N)
5383 while Present (P) loop
5385 N_Assignment_Statement,
5386 N_Raise_Constraint_Error)
5396 -- Do not give warning if we are in a conditional context
5399 K : constant Node_Kind := Nkind (Parent (N));
5401 if (K = N_Loop_Statement
5402 and then Present (Iteration_Scheme (Parent (N))))
5403 or else K = N_If_Statement
5404 or else K = N_Elsif_Part
5405 or else K = N_Case_Statement_Alternative
5411 -- Here warning is to be issued
5413 Set_Has_Recursive_Call (Nam);
5415 ("?possible infinite recursion!", N);
5417 ("\?Storage_Error may be raised at run time!", N);
5423 Scop := Scope (Scop);
5424 end loop Scope_Loop;
5428 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5430 Check_Obsolescent_2005_Entity (Nam, Subp);
5432 -- If subprogram name is a predefined operator, it was given in
5433 -- functional notation. Replace call node with operator node, so
5434 -- that actuals can be resolved appropriately.
5436 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5437 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5440 elsif Present (Alias (Nam))
5441 and then Is_Predefined_Op (Alias (Nam))
5443 Resolve_Actuals (N, Nam);
5444 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5448 -- Create a transient scope if the resulting type requires it
5450 -- There are several notable exceptions:
5452 -- a) In init procs, the transient scope overhead is not needed, and is
5453 -- even incorrect when the call is a nested initialization call for a
5454 -- component whose expansion may generate adjust calls. However, if the
5455 -- call is some other procedure call within an initialization procedure
5456 -- (for example a call to Create_Task in the init_proc of the task
5457 -- run-time record) a transient scope must be created around this call.
5459 -- b) Enumeration literal pseudo-calls need no transient scope
5461 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5462 -- functions) do not use the secondary stack even though the return
5463 -- type may be unconstrained.
5465 -- d) Calls to a build-in-place function, since such functions may
5466 -- allocate their result directly in a target object, and cases where
5467 -- the result does get allocated in the secondary stack are checked for
5468 -- within the specialized Exp_Ch6 procedures for expanding those
5469 -- build-in-place calls.
5471 -- e) If the subprogram is marked Inline_Always, then even if it returns
5472 -- an unconstrained type the call does not require use of the secondary
5473 -- stack. However, inlining will only take place if the body to inline
5474 -- is already present. It may not be available if e.g. the subprogram is
5475 -- declared in a child instance.
5477 -- If this is an initialization call for a type whose construction
5478 -- uses the secondary stack, and it is not a nested call to initialize
5479 -- a component, we do need to create a transient scope for it. We
5480 -- check for this by traversing the type in Check_Initialization_Call.
5483 and then Has_Pragma_Inline_Always (Nam)
5484 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5485 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5489 elsif Ekind (Nam) = E_Enumeration_Literal
5490 or else Is_Build_In_Place_Function (Nam)
5491 or else Is_Intrinsic_Subprogram (Nam)
5495 elsif Full_Expander_Active
5496 and then Is_Type (Etype (Nam))
5497 and then Requires_Transient_Scope (Etype (Nam))
5499 (not Within_Init_Proc
5501 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5503 Establish_Transient_Scope (N, Sec_Stack => True);
5505 -- If the call appears within the bounds of a loop, it will
5506 -- be rewritten and reanalyzed, nothing left to do here.
5508 if Nkind (N) /= N_Function_Call then
5512 elsif Is_Init_Proc (Nam)
5513 and then not Within_Init_Proc
5515 Check_Initialization_Call (N, Nam);
5518 -- A protected function cannot be called within the definition of the
5519 -- enclosing protected type.
5521 if Is_Protected_Type (Scope (Nam))
5522 and then In_Open_Scopes (Scope (Nam))
5523 and then not Has_Completion (Scope (Nam))
5526 ("& cannot be called before end of protected definition", N, Nam);
5529 -- Propagate interpretation to actuals, and add default expressions
5532 if Present (First_Formal (Nam)) then
5533 Resolve_Actuals (N, Nam);
5535 -- Overloaded literals are rewritten as function calls, for purpose of
5536 -- resolution. After resolution, we can replace the call with the
5539 elsif Ekind (Nam) = E_Enumeration_Literal then
5540 Copy_Node (Subp, N);
5541 Resolve_Entity_Name (N, Typ);
5543 -- Avoid validation, since it is a static function call
5545 Generate_Reference (Nam, Subp);
5549 -- If the subprogram is not global, then kill all saved values and
5550 -- checks. This is a bit conservative, since in many cases we could do
5551 -- better, but it is not worth the effort. Similarly, we kill constant
5552 -- values. However we do not need to do this for internal entities
5553 -- (unless they are inherited user-defined subprograms), since they
5554 -- are not in the business of molesting local values.
5556 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5557 -- kill all checks and values for calls to global subprograms. This
5558 -- takes care of the case where an access to a local subprogram is
5559 -- taken, and could be passed directly or indirectly and then called
5560 -- from almost any context.
5562 -- Note: we do not do this step till after resolving the actuals. That
5563 -- way we still take advantage of the current value information while
5564 -- scanning the actuals.
5566 -- We suppress killing values if we are processing the nodes associated
5567 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5568 -- type kills all the values as part of analyzing the code that
5569 -- initializes the dispatch tables.
5571 if Inside_Freezing_Actions = 0
5572 and then (not Is_Library_Level_Entity (Nam)
5573 or else Suppress_Value_Tracking_On_Call
5574 (Nearest_Dynamic_Scope (Current_Scope)))
5575 and then (Comes_From_Source (Nam)
5576 or else (Present (Alias (Nam))
5577 and then Comes_From_Source (Alias (Nam))))
5579 Kill_Current_Values;
5582 -- If we are warning about unread OUT parameters, this is the place to
5583 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5584 -- after the above call to Kill_Current_Values (since that call clears
5585 -- the Last_Assignment field of all local variables).
5587 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5588 and then Comes_From_Source (N)
5589 and then In_Extended_Main_Source_Unit (N)
5596 F := First_Formal (Nam);
5597 A := First_Actual (N);
5598 while Present (F) and then Present (A) loop
5599 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
5600 and then Warn_On_Modified_As_Out_Parameter (F)
5601 and then Is_Entity_Name (A)
5602 and then Present (Entity (A))
5603 and then Comes_From_Source (N)
5604 and then Safe_To_Capture_Value (N, Entity (A))
5606 Set_Last_Assignment (Entity (A), A);
5615 -- If the subprogram is a primitive operation, check whether or not
5616 -- it is a correct dispatching call.
5618 if Is_Overloadable (Nam)
5619 and then Is_Dispatching_Operation (Nam)
5621 Check_Dispatching_Call (N);
5623 elsif Ekind (Nam) /= E_Subprogram_Type
5624 and then Is_Abstract_Subprogram (Nam)
5625 and then not In_Instance
5627 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5630 -- If this is a dispatching call, generate the appropriate reference,
5631 -- for better source navigation in GPS.
5633 if Is_Overloadable (Nam)
5634 and then Present (Controlling_Argument (N))
5636 Generate_Reference (Nam, Subp, 'R');
5638 -- Normal case, not a dispatching call: generate a call reference
5641 Generate_Reference (Nam, Subp, 's');
5644 if Is_Intrinsic_Subprogram (Nam) then
5645 Check_Intrinsic_Call (N);
5648 -- Check for violation of restriction No_Specific_Termination_Handlers
5649 -- and warn on a potentially blocking call to Abort_Task.
5651 if Restriction_Check_Required (No_Specific_Termination_Handlers)
5652 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
5654 Is_RTE (Nam, RE_Specific_Handler))
5656 Check_Restriction (No_Specific_Termination_Handlers, N);
5658 elsif Is_RTE (Nam, RE_Abort_Task) then
5659 Check_Potentially_Blocking_Operation (N);
5662 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5663 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5664 -- need to check the second argument to determine whether it is an
5665 -- absolute or relative timing event.
5667 if Restriction_Check_Required (No_Relative_Delay)
5668 and then Is_RTE (Nam, RE_Set_Handler)
5669 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
5671 Check_Restriction (No_Relative_Delay, N);
5674 -- Issue an error for a call to an eliminated subprogram. We skip this
5675 -- in a spec expression, e.g. a call in a default parameter value, since
5676 -- we are not really doing a call at this time. That's important because
5677 -- the spec expression may itself belong to an eliminated subprogram.
5679 if not In_Spec_Expression then
5680 Check_For_Eliminated_Subprogram (Subp, Nam);
5683 -- In formal mode, the primitive operations of a tagged type or type
5684 -- extension do not include functions that return the tagged type.
5686 -- Commented out as the call to Is_Inherited_Operation_For_Type may
5687 -- cause an error because the type entity of the parent node of
5688 -- Entity (Name (N) may not be set. ???
5689 -- So why not just add a guard ???
5691 -- if Nkind (N) = N_Function_Call
5692 -- and then Is_Tagged_Type (Etype (N))
5693 -- and then Is_Entity_Name (Name (N))
5694 -- and then Is_Inherited_Operation_For_Type
5695 -- (Entity (Name (N)), Etype (N))
5697 -- Check_SPARK_Restriction ("function not inherited", N);
5700 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
5701 -- class-wide and the call dispatches on result in a context that does
5702 -- not provide a tag, the call raises Program_Error.
5704 if Nkind (N) = N_Function_Call
5705 and then In_Instance
5706 and then Is_Generic_Actual_Type (Typ)
5707 and then Is_Class_Wide_Type (Typ)
5708 and then Has_Controlling_Result (Nam)
5709 and then Nkind (Parent (N)) = N_Object_Declaration
5711 -- Verify that none of the formals are controlling
5714 Call_OK : Boolean := False;
5718 F := First_Formal (Nam);
5719 while Present (F) loop
5720 if Is_Controlling_Formal (F) then
5729 Error_Msg_N ("!? cannot determine tag of result", N);
5730 Error_Msg_N ("!? Program_Error will be raised", N);
5732 Make_Raise_Program_Error (Sloc (N),
5733 Reason => PE_Explicit_Raise));
5738 -- All done, evaluate call and deal with elaboration issues
5741 Check_Elab_Call (N);
5742 Warn_On_Overlapping_Actuals (Nam, N);
5745 -----------------------------
5746 -- Resolve_Case_Expression --
5747 -----------------------------
5749 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
5753 Alt := First (Alternatives (N));
5754 while Present (Alt) loop
5755 Resolve (Expression (Alt), Typ);
5760 Eval_Case_Expression (N);
5761 end Resolve_Case_Expression;
5763 -------------------------------
5764 -- Resolve_Character_Literal --
5765 -------------------------------
5767 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5768 B_Typ : constant Entity_Id := Base_Type (Typ);
5772 -- Verify that the character does belong to the type of the context
5774 Set_Etype (N, B_Typ);
5775 Eval_Character_Literal (N);
5777 -- Wide_Wide_Character literals must always be defined, since the set
5778 -- of wide wide character literals is complete, i.e. if a character
5779 -- literal is accepted by the parser, then it is OK for wide wide
5780 -- character (out of range character literals are rejected).
5782 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5785 -- Always accept character literal for type Any_Character, which
5786 -- occurs in error situations and in comparisons of literals, both
5787 -- of which should accept all literals.
5789 elsif B_Typ = Any_Character then
5792 -- For Standard.Character or a type derived from it, check that the
5793 -- literal is in range.
5795 elsif Root_Type (B_Typ) = Standard_Character then
5796 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5800 -- For Standard.Wide_Character or a type derived from it, check that the
5801 -- literal is in range.
5803 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5804 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5808 -- For Standard.Wide_Wide_Character or a type derived from it, we
5809 -- know the literal is in range, since the parser checked!
5811 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5814 -- If the entity is already set, this has already been resolved in a
5815 -- generic context, or comes from expansion. Nothing else to do.
5817 elsif Present (Entity (N)) then
5820 -- Otherwise we have a user defined character type, and we can use the
5821 -- standard visibility mechanisms to locate the referenced entity.
5824 C := Current_Entity (N);
5825 while Present (C) loop
5826 if Etype (C) = B_Typ then
5827 Set_Entity_With_Style_Check (N, C);
5828 Generate_Reference (C, N);
5836 -- If we fall through, then the literal does not match any of the
5837 -- entries of the enumeration type. This isn't just a constraint error
5838 -- situation, it is an illegality (see RM 4.2).
5841 ("character not defined for }", N, First_Subtype (B_Typ));
5842 end Resolve_Character_Literal;
5844 ---------------------------
5845 -- Resolve_Comparison_Op --
5846 ---------------------------
5848 -- Context requires a boolean type, and plays no role in resolution.
5849 -- Processing identical to that for equality operators. The result type is
5850 -- the base type, which matters when pathological subtypes of booleans with
5851 -- limited ranges are used.
5853 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5854 L : constant Node_Id := Left_Opnd (N);
5855 R : constant Node_Id := Right_Opnd (N);
5859 -- If this is an intrinsic operation which is not predefined, use the
5860 -- types of its declared arguments to resolve the possibly overloaded
5861 -- operands. Otherwise the operands are unambiguous and specify the
5864 if Scope (Entity (N)) /= Standard_Standard then
5865 T := Etype (First_Entity (Entity (N)));
5868 T := Find_Unique_Type (L, R);
5870 if T = Any_Fixed then
5871 T := Unique_Fixed_Point_Type (L);
5875 Set_Etype (N, Base_Type (Typ));
5876 Generate_Reference (T, N, ' ');
5878 -- Skip remaining processing if already set to Any_Type
5880 if T = Any_Type then
5884 -- Deal with other error cases
5886 if T = Any_String or else
5887 T = Any_Composite or else
5890 if T = Any_Character then
5891 Ambiguous_Character (L);
5893 Error_Msg_N ("ambiguous operands for comparison", N);
5896 Set_Etype (N, Any_Type);
5900 -- Resolve the operands if types OK
5904 Check_Unset_Reference (L);
5905 Check_Unset_Reference (R);
5906 Generate_Operator_Reference (N, T);
5907 Check_Low_Bound_Tested (N);
5909 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
5910 -- types or array types except String.
5912 if Is_Boolean_Type (T) then
5913 Check_SPARK_Restriction
5914 ("comparison is not defined on Boolean type", N);
5916 elsif Is_Array_Type (T)
5917 and then Base_Type (T) /= Standard_String
5919 Check_SPARK_Restriction
5920 ("comparison is not defined on array types other than String", N);
5923 -- Check comparison on unordered enumeration
5925 if Comes_From_Source (N)
5926 and then Bad_Unordered_Enumeration_Reference (N, Etype (L))
5928 Error_Msg_N ("comparison on unordered enumeration type?", N);
5931 -- Evaluate the relation (note we do this after the above check since
5932 -- this Eval call may change N to True/False.
5934 Eval_Relational_Op (N);
5935 end Resolve_Comparison_Op;
5937 ------------------------------------
5938 -- Resolve_Conditional_Expression --
5939 ------------------------------------
5941 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5942 Condition : constant Node_Id := First (Expressions (N));
5943 Then_Expr : constant Node_Id := Next (Condition);
5944 Else_Expr : Node_Id := Next (Then_Expr);
5947 Resolve (Condition, Any_Boolean);
5948 Resolve (Then_Expr, Typ);
5950 -- If ELSE expression present, just resolve using the determined type
5952 if Present (Else_Expr) then
5953 Resolve (Else_Expr, Typ);
5955 -- If no ELSE expression is present, root type must be Standard.Boolean
5956 -- and we provide a Standard.True result converted to the appropriate
5957 -- Boolean type (in case it is a derived boolean type).
5959 elsif Root_Type (Typ) = Standard_Boolean then
5961 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5962 Analyze_And_Resolve (Else_Expr, Typ);
5963 Append_To (Expressions (N), Else_Expr);
5966 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5967 Append_To (Expressions (N), Error);
5971 Eval_Conditional_Expression (N);
5972 end Resolve_Conditional_Expression;
5974 -----------------------------------------
5975 -- Resolve_Discrete_Subtype_Indication --
5976 -----------------------------------------
5978 procedure Resolve_Discrete_Subtype_Indication
5986 Analyze (Subtype_Mark (N));
5987 S := Entity (Subtype_Mark (N));
5989 if Nkind (Constraint (N)) /= N_Range_Constraint then
5990 Error_Msg_N ("expect range constraint for discrete type", N);
5991 Set_Etype (N, Any_Type);
5994 R := Range_Expression (Constraint (N));
6002 if Base_Type (S) /= Base_Type (Typ) then
6004 ("expect subtype of }", N, First_Subtype (Typ));
6006 -- Rewrite the constraint as a range of Typ
6007 -- to allow compilation to proceed further.
6010 Rewrite (Low_Bound (R),
6011 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6012 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6013 Attribute_Name => Name_First));
6014 Rewrite (High_Bound (R),
6015 Make_Attribute_Reference (Sloc (High_Bound (R)),
6016 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6017 Attribute_Name => Name_First));
6021 Set_Etype (N, Etype (R));
6023 -- Additionally, we must check that the bounds are compatible
6024 -- with the given subtype, which might be different from the
6025 -- type of the context.
6027 Apply_Range_Check (R, S);
6029 -- ??? If the above check statically detects a Constraint_Error
6030 -- it replaces the offending bound(s) of the range R with a
6031 -- Constraint_Error node. When the itype which uses these bounds
6032 -- is frozen the resulting call to Duplicate_Subexpr generates
6033 -- a new temporary for the bounds.
6035 -- Unfortunately there are other itypes that are also made depend
6036 -- on these bounds, so when Duplicate_Subexpr is called they get
6037 -- a forward reference to the newly created temporaries and Gigi
6038 -- aborts on such forward references. This is probably sign of a
6039 -- more fundamental problem somewhere else in either the order of
6040 -- itype freezing or the way certain itypes are constructed.
6042 -- To get around this problem we call Remove_Side_Effects right
6043 -- away if either bounds of R are a Constraint_Error.
6046 L : constant Node_Id := Low_Bound (R);
6047 H : constant Node_Id := High_Bound (R);
6050 if Nkind (L) = N_Raise_Constraint_Error then
6051 Remove_Side_Effects (L);
6054 if Nkind (H) = N_Raise_Constraint_Error then
6055 Remove_Side_Effects (H);
6059 Check_Unset_Reference (Low_Bound (R));
6060 Check_Unset_Reference (High_Bound (R));
6063 end Resolve_Discrete_Subtype_Indication;
6065 -------------------------
6066 -- Resolve_Entity_Name --
6067 -------------------------
6069 -- Used to resolve identifiers and expanded names
6071 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6072 E : constant Entity_Id := Entity (N);
6075 -- If garbage from errors, set to Any_Type and return
6077 if No (E) and then Total_Errors_Detected /= 0 then
6078 Set_Etype (N, Any_Type);
6082 -- Replace named numbers by corresponding literals. Note that this is
6083 -- the one case where Resolve_Entity_Name must reset the Etype, since
6084 -- it is currently marked as universal.
6086 if Ekind (E) = E_Named_Integer then
6088 Eval_Named_Integer (N);
6090 elsif Ekind (E) = E_Named_Real then
6092 Eval_Named_Real (N);
6094 -- For enumeration literals, we need to make sure that a proper style
6095 -- check is done, since such literals are overloaded, and thus we did
6096 -- not do a style check during the first phase of analysis.
6098 elsif Ekind (E) = E_Enumeration_Literal then
6099 Set_Entity_With_Style_Check (N, E);
6100 Eval_Entity_Name (N);
6102 -- Case of subtype name appearing as an operand in expression
6104 elsif Is_Type (E) then
6106 -- Allow use of subtype if it is a concurrent type where we are
6107 -- currently inside the body. This will eventually be expanded into a
6108 -- call to Self (for tasks) or _object (for protected objects). Any
6109 -- other use of a subtype is invalid.
6111 if Is_Concurrent_Type (E)
6112 and then In_Open_Scopes (E)
6116 -- Any other use is an error
6120 ("invalid use of subtype mark in expression or call", N);
6123 -- Check discriminant use if entity is discriminant in current scope,
6124 -- i.e. discriminant of record or concurrent type currently being
6125 -- analyzed. Uses in corresponding body are unrestricted.
6127 elsif Ekind (E) = E_Discriminant
6128 and then Scope (E) = Current_Scope
6129 and then not Has_Completion (Current_Scope)
6131 Check_Discriminant_Use (N);
6133 -- A parameterless generic function cannot appear in a context that
6134 -- requires resolution.
6136 elsif Ekind (E) = E_Generic_Function then
6137 Error_Msg_N ("illegal use of generic function", N);
6139 elsif Ekind (E) = E_Out_Parameter
6140 and then Ada_Version = Ada_83
6141 and then (Nkind (Parent (N)) in N_Op
6142 or else (Nkind (Parent (N)) = N_Assignment_Statement
6143 and then N = Expression (Parent (N)))
6144 or else Nkind (Parent (N)) = N_Explicit_Dereference)
6146 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6148 -- In all other cases, just do the possible static evaluation
6151 -- A deferred constant that appears in an expression must have a
6152 -- completion, unless it has been removed by in-place expansion of
6155 if Ekind (E) = E_Constant
6156 and then Comes_From_Source (E)
6157 and then No (Constant_Value (E))
6158 and then Is_Frozen (Etype (E))
6159 and then not In_Spec_Expression
6160 and then not Is_Imported (E)
6162 if No_Initialization (Parent (E))
6163 or else (Present (Full_View (E))
6164 and then No_Initialization (Parent (Full_View (E))))
6169 "deferred constant is frozen before completion", N);
6173 Eval_Entity_Name (N);
6175 end Resolve_Entity_Name;
6181 procedure Resolve_Entry (Entry_Name : Node_Id) is
6182 Loc : constant Source_Ptr := Sloc (Entry_Name);
6190 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6191 -- If the bounds of the entry family being called depend on task
6192 -- discriminants, build a new index subtype where a discriminant is
6193 -- replaced with the value of the discriminant of the target task.
6194 -- The target task is the prefix of the entry name in the call.
6196 -----------------------
6197 -- Actual_Index_Type --
6198 -----------------------
6200 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
6201 Typ : constant Entity_Id := Entry_Index_Type (E);
6202 Tsk : constant Entity_Id := Scope (E);
6203 Lo : constant Node_Id := Type_Low_Bound (Typ);
6204 Hi : constant Node_Id := Type_High_Bound (Typ);
6207 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6208 -- If the bound is given by a discriminant, replace with a reference
6209 -- to the discriminant of the same name in the target task. If the
6210 -- entry name is the target of a requeue statement and the entry is
6211 -- in the current protected object, the bound to be used is the
6212 -- discriminal of the object (see Apply_Range_Checks for details of
6213 -- the transformation).
6215 -----------------------------
6216 -- Actual_Discriminant_Ref --
6217 -----------------------------
6219 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
6220 Typ : constant Entity_Id := Etype (Bound);
6224 Remove_Side_Effects (Bound);
6226 if not Is_Entity_Name (Bound)
6227 or else Ekind (Entity (Bound)) /= E_Discriminant
6231 elsif Is_Protected_Type (Tsk)
6232 and then In_Open_Scopes (Tsk)
6233 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6235 -- Note: here Bound denotes a discriminant of the corresponding
6236 -- record type tskV, whose discriminal is a formal of the
6237 -- init-proc tskVIP. What we want is the body discriminal,
6238 -- which is associated to the discriminant of the original
6239 -- concurrent type tsk.
6241 return New_Occurrence_Of
6242 (Find_Body_Discriminal (Entity (Bound)), Loc);
6246 Make_Selected_Component (Loc,
6247 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6248 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6253 end Actual_Discriminant_Ref;
6255 -- Start of processing for Actual_Index_Type
6258 if not Has_Discriminants (Tsk)
6259 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
6261 return Entry_Index_Type (E);
6264 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6265 Set_Etype (New_T, Base_Type (Typ));
6266 Set_Size_Info (New_T, Typ);
6267 Set_RM_Size (New_T, RM_Size (Typ));
6268 Set_Scalar_Range (New_T,
6269 Make_Range (Sloc (Entry_Name),
6270 Low_Bound => Actual_Discriminant_Ref (Lo),
6271 High_Bound => Actual_Discriminant_Ref (Hi)));
6275 end Actual_Index_Type;
6277 -- Start of processing of Resolve_Entry
6280 -- Find name of entry being called, and resolve prefix of name with its
6281 -- own type. The prefix can be overloaded, and the name and signature of
6282 -- the entry must be taken into account.
6284 if Nkind (Entry_Name) = N_Indexed_Component then
6286 -- Case of dealing with entry family within the current tasks
6288 E_Name := Prefix (Entry_Name);
6291 E_Name := Entry_Name;
6294 if Is_Entity_Name (E_Name) then
6296 -- Entry call to an entry (or entry family) in the current task. This
6297 -- is legal even though the task will deadlock. Rewrite as call to
6300 -- This can also be a call to an entry in an enclosing task. If this
6301 -- is a single task, we have to retrieve its name, because the scope
6302 -- of the entry is the task type, not the object. If the enclosing
6303 -- task is a task type, the identity of the task is given by its own
6306 -- Finally this can be a requeue on an entry of the same task or
6307 -- protected object.
6309 S := Scope (Entity (E_Name));
6311 for J in reverse 0 .. Scope_Stack.Last loop
6312 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6313 and then not Comes_From_Source (S)
6315 -- S is an enclosing task or protected object. The concurrent
6316 -- declaration has been converted into a type declaration, and
6317 -- the object itself has an object declaration that follows
6318 -- the type in the same declarative part.
6320 Tsk := Next_Entity (S);
6321 while Etype (Tsk) /= S loop
6328 elsif S = Scope_Stack.Table (J).Entity then
6330 -- Call to current task. Will be transformed into call to Self
6338 Make_Selected_Component (Loc,
6339 Prefix => New_Occurrence_Of (S, Loc),
6341 New_Occurrence_Of (Entity (E_Name), Loc));
6342 Rewrite (E_Name, New_N);
6345 elsif Nkind (Entry_Name) = N_Selected_Component
6346 and then Is_Overloaded (Prefix (Entry_Name))
6348 -- Use the entry name (which must be unique at this point) to find
6349 -- the prefix that returns the corresponding task/protected type.
6352 Pref : constant Node_Id := Prefix (Entry_Name);
6353 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
6358 Get_First_Interp (Pref, I, It);
6359 while Present (It.Typ) loop
6360 if Scope (Ent) = It.Typ then
6361 Set_Etype (Pref, It.Typ);
6365 Get_Next_Interp (I, It);
6370 if Nkind (Entry_Name) = N_Selected_Component then
6371 Resolve (Prefix (Entry_Name));
6373 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6374 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6375 Resolve (Prefix (Prefix (Entry_Name)));
6376 Index := First (Expressions (Entry_Name));
6377 Resolve (Index, Entry_Index_Type (Nam));
6379 -- Up to this point the expression could have been the actual in a
6380 -- simple entry call, and be given by a named association.
6382 if Nkind (Index) = N_Parameter_Association then
6383 Error_Msg_N ("expect expression for entry index", Index);
6385 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6390 ------------------------
6391 -- Resolve_Entry_Call --
6392 ------------------------
6394 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6395 Entry_Name : constant Node_Id := Name (N);
6396 Loc : constant Source_Ptr := Sloc (Entry_Name);
6398 First_Named : Node_Id;
6405 -- We kill all checks here, because it does not seem worth the effort to
6406 -- do anything better, an entry call is a big operation.
6410 -- Processing of the name is similar for entry calls and protected
6411 -- operation calls. Once the entity is determined, we can complete
6412 -- the resolution of the actuals.
6414 -- The selector may be overloaded, in the case of a protected object
6415 -- with overloaded functions. The type of the context is used for
6418 if Nkind (Entry_Name) = N_Selected_Component
6419 and then Is_Overloaded (Selector_Name (Entry_Name))
6420 and then Typ /= Standard_Void_Type
6427 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6428 while Present (It.Typ) loop
6429 if Covers (Typ, It.Typ) then
6430 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6431 Set_Etype (Entry_Name, It.Typ);
6433 Generate_Reference (It.Typ, N, ' ');
6436 Get_Next_Interp (I, It);
6441 Resolve_Entry (Entry_Name);
6443 if Nkind (Entry_Name) = N_Selected_Component then
6445 -- Simple entry call
6447 Nam := Entity (Selector_Name (Entry_Name));
6448 Obj := Prefix (Entry_Name);
6449 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6451 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6453 -- Call to member of entry family
6455 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6456 Obj := Prefix (Prefix (Entry_Name));
6457 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6460 -- We cannot in general check the maximum depth of protected entry calls
6461 -- at compile time. But we can tell that any protected entry call at all
6462 -- violates a specified nesting depth of zero.
6464 if Is_Protected_Type (Scope (Nam)) then
6465 Check_Restriction (Max_Entry_Queue_Length, N);
6468 -- Use context type to disambiguate a protected function that can be
6469 -- called without actuals and that returns an array type, and where the
6470 -- argument list may be an indexing of the returned value.
6472 if Ekind (Nam) = E_Function
6473 and then Needs_No_Actuals (Nam)
6474 and then Present (Parameter_Associations (N))
6476 ((Is_Array_Type (Etype (Nam))
6477 and then Covers (Typ, Component_Type (Etype (Nam))))
6479 or else (Is_Access_Type (Etype (Nam))
6480 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6484 Component_Type (Designated_Type (Etype (Nam))))))
6487 Index_Node : Node_Id;
6491 Make_Indexed_Component (Loc,
6493 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
6494 Expressions => Parameter_Associations (N));
6496 -- Since we are correcting a node classification error made by the
6497 -- parser, we call Replace rather than Rewrite.
6499 Replace (N, Index_Node);
6500 Set_Etype (Prefix (N), Etype (Nam));
6502 Resolve_Indexed_Component (N, Typ);
6507 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6508 and then Present (PPC_Wrapper (Nam))
6509 and then Current_Scope /= PPC_Wrapper (Nam)
6511 -- Rewrite as call to the precondition wrapper, adding the task
6512 -- object to the list of actuals. If the call is to a member of an
6513 -- entry family, include the index as well.
6517 New_Actuals : List_Id;
6520 New_Actuals := New_List (Obj);
6522 if Nkind (Entry_Name) = N_Indexed_Component then
6523 Append_To (New_Actuals,
6524 New_Copy_Tree (First (Expressions (Entry_Name))));
6527 Append_List (Parameter_Associations (N), New_Actuals);
6529 Make_Procedure_Call_Statement (Loc,
6531 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6532 Parameter_Associations => New_Actuals);
6533 Rewrite (N, New_Call);
6534 Analyze_And_Resolve (N);
6539 -- The operation name may have been overloaded. Order the actuals
6540 -- according to the formals of the resolved entity, and set the return
6541 -- type to that of the operation.
6544 Normalize_Actuals (N, Nam, False, Norm_OK);
6545 pragma Assert (Norm_OK);
6546 Set_Etype (N, Etype (Nam));
6549 Resolve_Actuals (N, Nam);
6551 -- Create a call reference to the entry
6553 Generate_Reference (Nam, Entry_Name, 's');
6555 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
6556 Check_Potentially_Blocking_Operation (N);
6559 -- Verify that a procedure call cannot masquerade as an entry
6560 -- call where an entry call is expected.
6562 if Ekind (Nam) = E_Procedure then
6563 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6564 and then N = Entry_Call_Statement (Parent (N))
6566 Error_Msg_N ("entry call required in select statement", N);
6568 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6569 and then N = Triggering_Statement (Parent (N))
6571 Error_Msg_N ("triggering statement cannot be procedure call", N);
6573 elsif Ekind (Scope (Nam)) = E_Task_Type
6574 and then not In_Open_Scopes (Scope (Nam))
6576 Error_Msg_N ("task has no entry with this name", Entry_Name);
6580 -- After resolution, entry calls and protected procedure calls are
6581 -- changed into entry calls, for expansion. The structure of the node
6582 -- does not change, so it can safely be done in place. Protected
6583 -- function calls must keep their structure because they are
6586 if Ekind (Nam) /= E_Function then
6588 -- A protected operation that is not a function may modify the
6589 -- corresponding object, and cannot apply to a constant. If this
6590 -- is an internal call, the prefix is the type itself.
6592 if Is_Protected_Type (Scope (Nam))
6593 and then not Is_Variable (Obj)
6594 and then (not Is_Entity_Name (Obj)
6595 or else not Is_Type (Entity (Obj)))
6598 ("prefix of protected procedure or entry call must be variable",
6602 Actuals := Parameter_Associations (N);
6603 First_Named := First_Named_Actual (N);
6606 Make_Entry_Call_Statement (Loc,
6608 Parameter_Associations => Actuals));
6610 Set_First_Named_Actual (N, First_Named);
6611 Set_Analyzed (N, True);
6613 -- Protected functions can return on the secondary stack, in which
6614 -- case we must trigger the transient scope mechanism.
6616 elsif Full_Expander_Active
6617 and then Requires_Transient_Scope (Etype (Nam))
6619 Establish_Transient_Scope (N, Sec_Stack => True);
6621 end Resolve_Entry_Call;
6623 -------------------------
6624 -- Resolve_Equality_Op --
6625 -------------------------
6627 -- Both arguments must have the same type, and the boolean context does
6628 -- not participate in the resolution. The first pass verifies that the
6629 -- interpretation is not ambiguous, and the type of the left argument is
6630 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6631 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6632 -- though they carry a single (universal) type. Diagnose this case here.
6634 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6635 L : constant Node_Id := Left_Opnd (N);
6636 R : constant Node_Id := Right_Opnd (N);
6637 T : Entity_Id := Find_Unique_Type (L, R);
6639 procedure Check_Conditional_Expression (Cond : Node_Id);
6640 -- The resolution rule for conditional expressions requires that each
6641 -- such must have a unique type. This means that if several dependent
6642 -- expressions are of a non-null anonymous access type, and the context
6643 -- does not impose an expected type (as can be the case in an equality
6644 -- operation) the expression must be rejected.
6646 function Find_Unique_Access_Type return Entity_Id;
6647 -- In the case of allocators, make a last-ditch attempt to find a single
6648 -- access type with the right designated type. This is semantically
6649 -- dubious, and of no interest to any real code, but c48008a makes it
6652 ----------------------------------
6653 -- Check_Conditional_Expression --
6654 ----------------------------------
6656 procedure Check_Conditional_Expression (Cond : Node_Id) is
6657 Then_Expr : Node_Id;
6658 Else_Expr : Node_Id;
6661 if Nkind (Cond) = N_Conditional_Expression then
6662 Then_Expr := Next (First (Expressions (Cond)));
6663 Else_Expr := Next (Then_Expr);
6665 if Nkind (Then_Expr) /= N_Null
6666 and then Nkind (Else_Expr) /= N_Null
6669 ("cannot determine type of conditional expression", Cond);
6672 end Check_Conditional_Expression;
6674 -----------------------------
6675 -- Find_Unique_Access_Type --
6676 -----------------------------
6678 function Find_Unique_Access_Type return Entity_Id is
6684 if Ekind (Etype (R)) = E_Allocator_Type then
6685 Acc := Designated_Type (Etype (R));
6686 elsif Ekind (Etype (L)) = E_Allocator_Type then
6687 Acc := Designated_Type (Etype (L));
6693 while S /= Standard_Standard loop
6694 E := First_Entity (S);
6695 while Present (E) loop
6697 and then Is_Access_Type (E)
6698 and then Ekind (E) /= E_Allocator_Type
6699 and then Designated_Type (E) = Base_Type (Acc)
6711 end Find_Unique_Access_Type;
6713 -- Start of processing for Resolve_Equality_Op
6716 Set_Etype (N, Base_Type (Typ));
6717 Generate_Reference (T, N, ' ');
6719 if T = Any_Fixed then
6720 T := Unique_Fixed_Point_Type (L);
6723 if T /= Any_Type then
6724 if T = Any_String or else
6725 T = Any_Composite or else
6728 if T = Any_Character then
6729 Ambiguous_Character (L);
6731 Error_Msg_N ("ambiguous operands for equality", N);
6734 Set_Etype (N, Any_Type);
6737 elsif T = Any_Access
6738 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
6740 T := Find_Unique_Access_Type;
6743 Error_Msg_N ("ambiguous operands for equality", N);
6744 Set_Etype (N, Any_Type);
6748 -- Conditional expressions must have a single type, and if the
6749 -- context does not impose one the dependent expressions cannot
6750 -- be anonymous access types.
6752 elsif Ada_Version >= Ada_2012
6753 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
6754 E_Anonymous_Access_Subprogram_Type)
6755 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
6756 E_Anonymous_Access_Subprogram_Type)
6758 Check_Conditional_Expression (L);
6759 Check_Conditional_Expression (R);
6765 -- In SPARK, equality operators = and /= for array types other than
6766 -- String are only defined when, for each index position, the
6767 -- operands have equal static bounds.
6769 if Is_Array_Type (T) then
6770 -- Protect call to Matching_Static_Array_Bounds to avoid costly
6771 -- operation if not needed.
6773 if Restriction_Check_Required (SPARK)
6774 and then Base_Type (T) /= Standard_String
6775 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6776 and then Etype (L) /= Any_Composite -- or else L in error
6777 and then Etype (R) /= Any_Composite -- or else R in error
6778 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
6780 Check_SPARK_Restriction
6781 ("array types should have matching static bounds", N);
6785 -- If the unique type is a class-wide type then it will be expanded
6786 -- into a dispatching call to the predefined primitive. Therefore we
6787 -- check here for potential violation of such restriction.
6789 if Is_Class_Wide_Type (T) then
6790 Check_Restriction (No_Dispatching_Calls, N);
6793 if Warn_On_Redundant_Constructs
6794 and then Comes_From_Source (N)
6795 and then Is_Entity_Name (R)
6796 and then Entity (R) = Standard_True
6797 and then Comes_From_Source (R)
6799 Error_Msg_N -- CODEFIX
6800 ("?comparison with True is redundant!", R);
6803 Check_Unset_Reference (L);
6804 Check_Unset_Reference (R);
6805 Generate_Operator_Reference (N, T);
6806 Check_Low_Bound_Tested (N);
6808 -- If this is an inequality, it may be the implicit inequality
6809 -- created for a user-defined operation, in which case the corres-
6810 -- ponding equality operation is not intrinsic, and the operation
6811 -- cannot be constant-folded. Else fold.
6813 if Nkind (N) = N_Op_Eq
6814 or else Comes_From_Source (Entity (N))
6815 or else Ekind (Entity (N)) = E_Operator
6816 or else Is_Intrinsic_Subprogram
6817 (Corresponding_Equality (Entity (N)))
6819 Eval_Relational_Op (N);
6821 elsif Nkind (N) = N_Op_Ne
6822 and then Is_Abstract_Subprogram (Entity (N))
6824 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6827 -- Ada 2005: If one operand is an anonymous access type, convert the
6828 -- other operand to it, to ensure that the underlying types match in
6829 -- the back-end. Same for access_to_subprogram, and the conversion
6830 -- verifies that the types are subtype conformant.
6832 -- We apply the same conversion in the case one of the operands is a
6833 -- private subtype of the type of the other.
6835 -- Why the Expander_Active test here ???
6837 if Full_Expander_Active
6839 (Ekind_In (T, E_Anonymous_Access_Type,
6840 E_Anonymous_Access_Subprogram_Type)
6841 or else Is_Private_Type (T))
6843 if Etype (L) /= T then
6845 Make_Unchecked_Type_Conversion (Sloc (L),
6846 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6847 Expression => Relocate_Node (L)));
6848 Analyze_And_Resolve (L, T);
6851 if (Etype (R)) /= T then
6853 Make_Unchecked_Type_Conversion (Sloc (R),
6854 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6855 Expression => Relocate_Node (R)));
6856 Analyze_And_Resolve (R, T);
6860 end Resolve_Equality_Op;
6862 ----------------------------------
6863 -- Resolve_Explicit_Dereference --
6864 ----------------------------------
6866 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6867 Loc : constant Source_Ptr := Sloc (N);
6869 P : constant Node_Id := Prefix (N);
6874 Check_Fully_Declared_Prefix (Typ, P);
6876 if Is_Overloaded (P) then
6878 -- Use the context type to select the prefix that has the correct
6881 Get_First_Interp (P, I, It);
6882 while Present (It.Typ) loop
6883 exit when Is_Access_Type (It.Typ)
6884 and then Covers (Typ, Designated_Type (It.Typ));
6885 Get_Next_Interp (I, It);
6888 if Present (It.Typ) then
6889 Resolve (P, It.Typ);
6891 -- If no interpretation covers the designated type of the prefix,
6892 -- this is the pathological case where not all implementations of
6893 -- the prefix allow the interpretation of the node as a call. Now
6894 -- that the expected type is known, Remove other interpretations
6895 -- from prefix, rewrite it as a call, and resolve again, so that
6896 -- the proper call node is generated.
6898 Get_First_Interp (P, I, It);
6899 while Present (It.Typ) loop
6900 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6904 Get_Next_Interp (I, It);
6908 Make_Function_Call (Loc,
6910 Make_Explicit_Dereference (Loc,
6912 Parameter_Associations => New_List);
6914 Save_Interps (N, New_N);
6916 Analyze_And_Resolve (N, Typ);
6920 Set_Etype (N, Designated_Type (It.Typ));
6926 if Is_Access_Type (Etype (P)) then
6927 Apply_Access_Check (N);
6930 -- If the designated type is a packed unconstrained array type, and the
6931 -- explicit dereference is not in the context of an attribute reference,
6932 -- then we must compute and set the actual subtype, since it is needed
6933 -- by Gigi. The reason we exclude the attribute case is that this is
6934 -- handled fine by Gigi, and in fact we use such attributes to build the
6935 -- actual subtype. We also exclude generated code (which builds actual
6936 -- subtypes directly if they are needed).
6938 if Is_Array_Type (Etype (N))
6939 and then Is_Packed (Etype (N))
6940 and then not Is_Constrained (Etype (N))
6941 and then Nkind (Parent (N)) /= N_Attribute_Reference
6942 and then Comes_From_Source (N)
6944 Set_Etype (N, Get_Actual_Subtype (N));
6947 -- Note: No Eval processing is required for an explicit dereference,
6948 -- because such a name can never be static.
6950 end Resolve_Explicit_Dereference;
6952 -------------------------------------
6953 -- Resolve_Expression_With_Actions --
6954 -------------------------------------
6956 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
6959 end Resolve_Expression_With_Actions;
6961 -------------------------------
6962 -- Resolve_Indexed_Component --
6963 -------------------------------
6965 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6966 Name : constant Node_Id := Prefix (N);
6968 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6972 if Is_Overloaded (Name) then
6974 -- Use the context type to select the prefix that yields the correct
6980 I1 : Interp_Index := 0;
6981 P : constant Node_Id := Prefix (N);
6982 Found : Boolean := False;
6985 Get_First_Interp (P, I, It);
6986 while Present (It.Typ) loop
6987 if (Is_Array_Type (It.Typ)
6988 and then Covers (Typ, Component_Type (It.Typ)))
6989 or else (Is_Access_Type (It.Typ)
6990 and then Is_Array_Type (Designated_Type (It.Typ))
6994 Component_Type (Designated_Type (It.Typ))))
6997 It := Disambiguate (P, I1, I, Any_Type);
6999 if It = No_Interp then
7000 Error_Msg_N ("ambiguous prefix for indexing", N);
7006 Array_Type := It.Typ;
7012 Array_Type := It.Typ;
7017 Get_Next_Interp (I, It);
7022 Array_Type := Etype (Name);
7025 Resolve (Name, Array_Type);
7026 Array_Type := Get_Actual_Subtype_If_Available (Name);
7028 -- If prefix is access type, dereference to get real array type.
7029 -- Note: we do not apply an access check because the expander always
7030 -- introduces an explicit dereference, and the check will happen there.
7032 if Is_Access_Type (Array_Type) then
7033 Array_Type := Designated_Type (Array_Type);
7036 -- If name was overloaded, set component type correctly now
7037 -- If a misplaced call to an entry family (which has no index types)
7038 -- return. Error will be diagnosed from calling context.
7040 if Is_Array_Type (Array_Type) then
7041 Set_Etype (N, Component_Type (Array_Type));
7046 Index := First_Index (Array_Type);
7047 Expr := First (Expressions (N));
7049 -- The prefix may have resolved to a string literal, in which case its
7050 -- etype has a special representation. This is only possible currently
7051 -- if the prefix is a static concatenation, written in functional
7054 if Ekind (Array_Type) = E_String_Literal_Subtype then
7055 Resolve (Expr, Standard_Positive);
7058 while Present (Index) and Present (Expr) loop
7059 Resolve (Expr, Etype (Index));
7060 Check_Unset_Reference (Expr);
7062 if Is_Scalar_Type (Etype (Expr)) then
7063 Apply_Scalar_Range_Check (Expr, Etype (Index));
7065 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
7073 -- Do not generate the warning on suspicious index if we are analyzing
7074 -- package Ada.Tags; otherwise we will report the warning with the
7075 -- Prims_Ptr field of the dispatch table.
7077 if Scope (Etype (Prefix (N))) = Standard_Standard
7079 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
7082 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
7083 Eval_Indexed_Component (N);
7086 -- If the array type is atomic, and is packed, and we are in a left side
7087 -- context, then this is worth a warning, since we have a situation
7088 -- where the access to the component may cause extra read/writes of
7089 -- the atomic array object, which could be considered unexpected.
7091 if Nkind (N) = N_Indexed_Component
7092 and then (Is_Atomic (Array_Type)
7093 or else (Is_Entity_Name (Prefix (N))
7094 and then Is_Atomic (Entity (Prefix (N)))))
7095 and then Is_Bit_Packed_Array (Array_Type)
7098 Error_Msg_N ("?assignment to component of packed atomic array",
7100 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
7103 end Resolve_Indexed_Component;
7105 -----------------------------
7106 -- Resolve_Integer_Literal --
7107 -----------------------------
7109 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7112 Eval_Integer_Literal (N);
7113 end Resolve_Integer_Literal;
7115 --------------------------------
7116 -- Resolve_Intrinsic_Operator --
7117 --------------------------------
7119 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
7120 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7122 Orig_Op : constant Entity_Id := Entity (N);
7126 function Convert_Operand (Opnd : Node_Id) return Node_Id;
7127 -- If the operand is a literal, it cannot be the expression in a
7128 -- conversion. Use a qualified expression instead.
7130 function Convert_Operand (Opnd : Node_Id) return Node_Id is
7131 Loc : constant Source_Ptr := Sloc (Opnd);
7134 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
7136 Make_Qualified_Expression (Loc,
7137 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7138 Expression => Relocate_Node (Opnd));
7142 Res := Unchecked_Convert_To (Btyp, Opnd);
7146 end Convert_Operand;
7148 -- Start of processing for Resolve_Intrinsic_Operator
7151 -- We must preserve the original entity in a generic setting, so that
7152 -- the legality of the operation can be verified in an instance.
7154 if not Full_Expander_Active then
7159 while Scope (Op) /= Standard_Standard loop
7161 pragma Assert (Present (Op));
7165 Set_Is_Overloaded (N, False);
7167 -- If the result or operand types are private, rewrite with unchecked
7168 -- conversions on the operands and the result, to expose the proper
7169 -- underlying numeric type.
7171 if Is_Private_Type (Typ)
7172 or else Is_Private_Type (Etype (Left_Opnd (N)))
7173 or else Is_Private_Type (Etype (Right_Opnd (N)))
7175 Arg1 := Convert_Operand (Left_Opnd (N));
7176 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
7178 if Nkind (N) = N_Op_Expon then
7179 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7181 Arg2 := Convert_Operand (Right_Opnd (N));
7184 if Nkind (Arg1) = N_Type_Conversion then
7185 Save_Interps (Left_Opnd (N), Expression (Arg1));
7188 if Nkind (Arg2) = N_Type_Conversion then
7189 Save_Interps (Right_Opnd (N), Expression (Arg2));
7192 Set_Left_Opnd (N, Arg1);
7193 Set_Right_Opnd (N, Arg2);
7195 Set_Etype (N, Btyp);
7196 Rewrite (N, Unchecked_Convert_To (Typ, N));
7199 elsif Typ /= Etype (Left_Opnd (N))
7200 or else Typ /= Etype (Right_Opnd (N))
7202 -- Add explicit conversion where needed, and save interpretations in
7203 -- case operands are overloaded. If the context is a VMS operation,
7204 -- assert that the conversion is legal (the operands have the proper
7205 -- types to select the VMS intrinsic). Note that in rare cases the
7206 -- VMS operators may be visible, but the default System is being used
7207 -- and Address is a private type.
7209 Arg1 := Convert_To (Typ, Left_Opnd (N));
7210 Arg2 := Convert_To (Typ, Right_Opnd (N));
7212 if Nkind (Arg1) = N_Type_Conversion then
7213 Save_Interps (Left_Opnd (N), Expression (Arg1));
7215 if Is_VMS_Operator (Orig_Op) then
7216 Set_Conversion_OK (Arg1);
7219 Save_Interps (Left_Opnd (N), Arg1);
7222 if Nkind (Arg2) = N_Type_Conversion then
7223 Save_Interps (Right_Opnd (N), Expression (Arg2));
7225 if Is_VMS_Operator (Orig_Op) then
7226 Set_Conversion_OK (Arg2);
7229 Save_Interps (Right_Opnd (N), Arg2);
7232 Rewrite (Left_Opnd (N), Arg1);
7233 Rewrite (Right_Opnd (N), Arg2);
7236 Resolve_Arithmetic_Op (N, Typ);
7239 Resolve_Arithmetic_Op (N, Typ);
7241 end Resolve_Intrinsic_Operator;
7243 --------------------------------------
7244 -- Resolve_Intrinsic_Unary_Operator --
7245 --------------------------------------
7247 procedure Resolve_Intrinsic_Unary_Operator
7251 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7257 while Scope (Op) /= Standard_Standard loop
7259 pragma Assert (Present (Op));
7264 if Is_Private_Type (Typ) then
7265 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7266 Save_Interps (Right_Opnd (N), Expression (Arg2));
7268 Set_Right_Opnd (N, Arg2);
7270 Set_Etype (N, Btyp);
7271 Rewrite (N, Unchecked_Convert_To (Typ, N));
7275 Resolve_Unary_Op (N, Typ);
7277 end Resolve_Intrinsic_Unary_Operator;
7279 ------------------------
7280 -- Resolve_Logical_Op --
7281 ------------------------
7283 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7287 Check_No_Direct_Boolean_Operators (N);
7289 -- Predefined operations on scalar types yield the base type. On the
7290 -- other hand, logical operations on arrays yield the type of the
7291 -- arguments (and the context).
7293 if Is_Array_Type (Typ) then
7296 B_Typ := Base_Type (Typ);
7299 -- OK if this is a VMS-specific intrinsic operation
7301 if Is_VMS_Operator (Entity (N)) then
7304 -- The following test is required because the operands of the operation
7305 -- may be literals, in which case the resulting type appears to be
7306 -- compatible with a signed integer type, when in fact it is compatible
7307 -- only with modular types. If the context itself is universal, the
7308 -- operation is illegal.
7310 elsif not Valid_Boolean_Arg (Typ) then
7311 Error_Msg_N ("invalid context for logical operation", N);
7312 Set_Etype (N, Any_Type);
7315 elsif Typ = Any_Modular then
7317 ("no modular type available in this context", N);
7318 Set_Etype (N, Any_Type);
7321 elsif Is_Modular_Integer_Type (Typ)
7322 and then Etype (Left_Opnd (N)) = Universal_Integer
7323 and then Etype (Right_Opnd (N)) = Universal_Integer
7325 Check_For_Visible_Operator (N, B_Typ);
7328 Resolve (Left_Opnd (N), B_Typ);
7329 Resolve (Right_Opnd (N), B_Typ);
7331 Check_Unset_Reference (Left_Opnd (N));
7332 Check_Unset_Reference (Right_Opnd (N));
7334 Set_Etype (N, B_Typ);
7335 Generate_Operator_Reference (N, B_Typ);
7336 Eval_Logical_Op (N);
7338 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
7339 -- only when both operands have same static lower and higher bounds. Of
7340 -- course the types have to match, so only check if operands are
7341 -- compatible and the node itself has no errors.
7343 if Is_Array_Type (B_Typ)
7344 and then Nkind (N) in N_Binary_Op
7347 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
7348 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
7351 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7352 -- operation if not needed.
7354 if Restriction_Check_Required (SPARK)
7355 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
7356 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
7357 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
7358 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
7360 Check_SPARK_Restriction
7361 ("array types should have matching static bounds", N);
7365 end Resolve_Logical_Op;
7367 ---------------------------
7368 -- Resolve_Membership_Op --
7369 ---------------------------
7371 -- The context can only be a boolean type, and does not determine the
7372 -- arguments. Arguments should be unambiguous, but the preference rule for
7373 -- universal types applies.
7375 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
7376 pragma Warnings (Off, Typ);
7378 L : constant Node_Id := Left_Opnd (N);
7379 R : constant Node_Id := Right_Opnd (N);
7382 procedure Resolve_Set_Membership;
7383 -- Analysis has determined a unique type for the left operand. Use it to
7384 -- resolve the disjuncts.
7386 ----------------------------
7387 -- Resolve_Set_Membership --
7388 ----------------------------
7390 procedure Resolve_Set_Membership is
7394 Resolve (L, Etype (L));
7396 Alt := First (Alternatives (N));
7397 while Present (Alt) loop
7399 -- Alternative is an expression, a range
7400 -- or a subtype mark.
7402 if not Is_Entity_Name (Alt)
7403 or else not Is_Type (Entity (Alt))
7405 Resolve (Alt, Etype (L));
7410 end Resolve_Set_Membership;
7412 -- Start of processing for Resolve_Membership_Op
7415 if L = Error or else R = Error then
7419 if Present (Alternatives (N)) then
7420 Resolve_Set_Membership;
7423 elsif not Is_Overloaded (R)
7425 (Etype (R) = Universal_Integer
7427 Etype (R) = Universal_Real)
7428 and then Is_Overloaded (L)
7432 -- Ada 2005 (AI-251): Support the following case:
7434 -- type I is interface;
7435 -- type T is tagged ...
7437 -- function Test (O : I'Class) is
7439 -- return O in T'Class.
7442 -- In this case we have nothing else to do. The membership test will be
7443 -- done at run time.
7445 elsif Ada_Version >= Ada_2005
7446 and then Is_Class_Wide_Type (Etype (L))
7447 and then Is_Interface (Etype (L))
7448 and then Is_Class_Wide_Type (Etype (R))
7449 and then not Is_Interface (Etype (R))
7453 T := Intersect_Types (L, R);
7456 -- If mixed-mode operations are present and operands are all literal,
7457 -- the only interpretation involves Duration, which is probably not
7458 -- the intention of the programmer.
7460 if T = Any_Fixed then
7461 T := Unique_Fixed_Point_Type (N);
7463 if T = Any_Type then
7469 Check_Unset_Reference (L);
7471 if Nkind (R) = N_Range
7472 and then not Is_Scalar_Type (T)
7474 Error_Msg_N ("scalar type required for range", R);
7477 if Is_Entity_Name (R) then
7478 Freeze_Expression (R);
7481 Check_Unset_Reference (R);
7484 Eval_Membership_Op (N);
7485 end Resolve_Membership_Op;
7491 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
7492 Loc : constant Source_Ptr := Sloc (N);
7495 -- Handle restriction against anonymous null access values This
7496 -- restriction can be turned off using -gnatdj.
7498 -- Ada 2005 (AI-231): Remove restriction
7500 if Ada_Version < Ada_2005
7501 and then not Debug_Flag_J
7502 and then Ekind (Typ) = E_Anonymous_Access_Type
7503 and then Comes_From_Source (N)
7505 -- In the common case of a call which uses an explicitly null value
7506 -- for an access parameter, give specialized error message.
7508 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
7512 ("null is not allowed as argument for an access parameter", N);
7514 -- Standard message for all other cases (are there any?)
7518 ("null cannot be of an anonymous access type", N);
7522 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7523 -- assignment to a null-excluding object
7525 if Ada_Version >= Ada_2005
7526 and then Can_Never_Be_Null (Typ)
7527 and then Nkind (Parent (N)) = N_Assignment_Statement
7529 if not Inside_Init_Proc then
7531 (Compile_Time_Constraint_Error (N,
7532 "(Ada 2005) null not allowed in null-excluding objects?"),
7533 Make_Raise_Constraint_Error (Loc,
7534 Reason => CE_Access_Check_Failed));
7537 Make_Raise_Constraint_Error (Loc,
7538 Reason => CE_Access_Check_Failed));
7542 -- In a distributed context, null for a remote access to subprogram may
7543 -- need to be replaced with a special record aggregate. In this case,
7544 -- return after having done the transformation.
7546 if (Ekind (Typ) = E_Record_Type
7547 or else Is_Remote_Access_To_Subprogram_Type (Typ))
7548 and then Remote_AST_Null_Value (N, Typ)
7553 -- The null literal takes its type from the context
7558 -----------------------
7559 -- Resolve_Op_Concat --
7560 -----------------------
7562 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
7564 -- We wish to avoid deep recursion, because concatenations are often
7565 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
7566 -- operands nonrecursively until we find something that is not a simple
7567 -- concatenation (A in this case). We resolve that, and then walk back
7568 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
7569 -- to do the rest of the work at each level. The Parent pointers allow
7570 -- us to avoid recursion, and thus avoid running out of memory. See also
7571 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
7577 -- The following code is equivalent to:
7579 -- Resolve_Op_Concat_First (NN, Typ);
7580 -- Resolve_Op_Concat_Arg (N, ...);
7581 -- Resolve_Op_Concat_Rest (N, Typ);
7583 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
7584 -- operand is a concatenation.
7586 -- Walk down left operands
7589 Resolve_Op_Concat_First (NN, Typ);
7590 Op1 := Left_Opnd (NN);
7591 exit when not (Nkind (Op1) = N_Op_Concat
7592 and then not Is_Array_Type (Component_Type (Typ))
7593 and then Entity (Op1) = Entity (NN));
7597 -- Now (given the above example) NN is A&B and Op1 is A
7599 -- First resolve Op1 ...
7601 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7603 -- ... then walk NN back up until we reach N (where we started), calling
7604 -- Resolve_Op_Concat_Rest along the way.
7607 Resolve_Op_Concat_Rest (NN, Typ);
7612 if Base_Type (Etype (N)) /= Standard_String then
7613 Check_SPARK_Restriction
7614 ("result of concatenation should have type String", N);
7616 end Resolve_Op_Concat;
7618 ---------------------------
7619 -- Resolve_Op_Concat_Arg --
7620 ---------------------------
7622 procedure Resolve_Op_Concat_Arg
7628 Btyp : constant Entity_Id := Base_Type (Typ);
7629 Ctyp : constant Entity_Id := Component_Type (Typ);
7634 or else (not Is_Overloaded (Arg)
7635 and then Etype (Arg) /= Any_Composite
7636 and then Covers (Ctyp, Etype (Arg)))
7638 Resolve (Arg, Ctyp);
7640 Resolve (Arg, Btyp);
7643 -- If both Array & Array and Array & Component are visible, there is a
7644 -- potential ambiguity that must be reported.
7646 elsif Has_Compatible_Type (Arg, Ctyp) then
7647 if Nkind (Arg) = N_Aggregate
7648 and then Is_Composite_Type (Ctyp)
7650 if Is_Private_Type (Ctyp) then
7651 Resolve (Arg, Btyp);
7653 -- If the operation is user-defined and not overloaded use its
7654 -- profile. The operation may be a renaming, in which case it has
7655 -- been rewritten, and we want the original profile.
7657 elsif not Is_Overloaded (N)
7658 and then Comes_From_Source (Entity (Original_Node (N)))
7659 and then Ekind (Entity (Original_Node (N))) = E_Function
7663 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
7666 -- Otherwise an aggregate may match both the array type and the
7670 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7671 Set_Etype (Arg, Any_Type);
7675 if Is_Overloaded (Arg)
7676 and then Has_Compatible_Type (Arg, Typ)
7677 and then Etype (Arg) /= Any_Type
7685 Get_First_Interp (Arg, I, It);
7687 Get_Next_Interp (I, It);
7689 -- Special-case the error message when the overloading is
7690 -- caused by a function that yields an array and can be
7691 -- called without parameters.
7693 if It.Nam = Func then
7694 Error_Msg_Sloc := Sloc (Func);
7695 Error_Msg_N ("ambiguous call to function#", Arg);
7697 ("\\interpretation as call yields&", Arg, Typ);
7699 ("\\interpretation as indexing of call yields&",
7700 Arg, Component_Type (Typ));
7703 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
7705 Get_First_Interp (Arg, I, It);
7706 while Present (It.Nam) loop
7707 Error_Msg_Sloc := Sloc (It.Nam);
7709 if Base_Type (It.Typ) = Btyp
7711 Base_Type (It.Typ) = Base_Type (Ctyp)
7713 Error_Msg_N -- CODEFIX
7714 ("\\possible interpretation#", Arg);
7717 Get_Next_Interp (I, It);
7723 Resolve (Arg, Component_Type (Typ));
7725 if Nkind (Arg) = N_String_Literal then
7726 Set_Etype (Arg, Component_Type (Typ));
7729 if Arg = Left_Opnd (N) then
7730 Set_Is_Component_Left_Opnd (N);
7732 Set_Is_Component_Right_Opnd (N);
7737 Resolve (Arg, Btyp);
7740 -- Concatenation is restricted in SPARK: each operand must be either a
7741 -- string literal, the name of a string constant, a static character or
7742 -- string expression, or another concatenation. Arg cannot be a
7743 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
7744 -- separately on each final operand, past concatenation operations.
7746 if Is_Character_Type (Etype (Arg)) then
7747 if not Is_Static_Expression (Arg) then
7748 Check_SPARK_Restriction
7749 ("character operand for concatenation should be static", Arg);
7752 elsif Is_String_Type (Etype (Arg)) then
7753 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
7754 and then Is_Constant_Object (Entity (Arg)))
7755 and then not Is_Static_Expression (Arg)
7757 Check_SPARK_Restriction
7758 ("string operand for concatenation should be static", Arg);
7761 -- Do not issue error on an operand that is neither a character nor a
7762 -- string, as the error is issued in Resolve_Op_Concat.
7768 Check_Unset_Reference (Arg);
7769 end Resolve_Op_Concat_Arg;
7771 -----------------------------
7772 -- Resolve_Op_Concat_First --
7773 -----------------------------
7775 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7776 Btyp : constant Entity_Id := Base_Type (Typ);
7777 Op1 : constant Node_Id := Left_Opnd (N);
7778 Op2 : constant Node_Id := Right_Opnd (N);
7781 -- The parser folds an enormous sequence of concatenations of string
7782 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7783 -- in the right operand. If the expression resolves to a predefined "&"
7784 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7785 -- we give an error. See P_Simple_Expression in Par.Ch4.
7787 if Nkind (Op2) = N_String_Literal
7788 and then Is_Folded_In_Parser (Op2)
7789 and then Ekind (Entity (N)) = E_Function
7791 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7792 and then String_Length (Strval (Op1)) = 0);
7793 Error_Msg_N ("too many user-defined concatenations", N);
7797 Set_Etype (N, Btyp);
7799 if Is_Limited_Composite (Btyp) then
7800 Error_Msg_N ("concatenation not available for limited array", N);
7801 Explain_Limited_Type (Btyp, N);
7803 end Resolve_Op_Concat_First;
7805 ----------------------------
7806 -- Resolve_Op_Concat_Rest --
7807 ----------------------------
7809 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7810 Op1 : constant Node_Id := Left_Opnd (N);
7811 Op2 : constant Node_Id := Right_Opnd (N);
7814 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7816 Generate_Operator_Reference (N, Typ);
7818 if Is_String_Type (Typ) then
7819 Eval_Concatenation (N);
7822 -- If this is not a static concatenation, but the result is a string
7823 -- type (and not an array of strings) ensure that static string operands
7824 -- have their subtypes properly constructed.
7826 if Nkind (N) /= N_String_Literal
7827 and then Is_Character_Type (Component_Type (Typ))
7829 Set_String_Literal_Subtype (Op1, Typ);
7830 Set_String_Literal_Subtype (Op2, Typ);
7832 end Resolve_Op_Concat_Rest;
7834 ----------------------
7835 -- Resolve_Op_Expon --
7836 ----------------------
7838 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7839 B_Typ : constant Entity_Id := Base_Type (Typ);
7842 -- Catch attempts to do fixed-point exponentiation with universal
7843 -- operands, which is a case where the illegality is not caught during
7844 -- normal operator analysis.
7846 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7847 Error_Msg_N ("exponentiation not available for fixed point", N);
7850 elsif Nkind (Parent (N)) in N_Op
7851 and then Is_Fixed_Point_Type (Etype (Parent (N)))
7852 and then Etype (N) = Universal_Real
7853 and then Comes_From_Source (N)
7855 Error_Msg_N ("exponentiation not available for fixed point", N);
7859 if Comes_From_Source (N)
7860 and then Ekind (Entity (N)) = E_Function
7861 and then Is_Imported (Entity (N))
7862 and then Is_Intrinsic_Subprogram (Entity (N))
7864 Resolve_Intrinsic_Operator (N, Typ);
7868 if Etype (Left_Opnd (N)) = Universal_Integer
7869 or else Etype (Left_Opnd (N)) = Universal_Real
7871 Check_For_Visible_Operator (N, B_Typ);
7874 -- We do the resolution using the base type, because intermediate values
7875 -- in expressions always are of the base type, not a subtype of it.
7877 Resolve (Left_Opnd (N), B_Typ);
7878 Resolve (Right_Opnd (N), Standard_Integer);
7880 Check_Unset_Reference (Left_Opnd (N));
7881 Check_Unset_Reference (Right_Opnd (N));
7883 Set_Etype (N, B_Typ);
7884 Generate_Operator_Reference (N, B_Typ);
7887 -- Set overflow checking bit. Much cleverer code needed here eventually
7888 -- and perhaps the Resolve routines should be separated for the various
7889 -- arithmetic operations, since they will need different processing. ???
7891 if Nkind (N) in N_Op then
7892 if not Overflow_Checks_Suppressed (Etype (N)) then
7893 Enable_Overflow_Check (N);
7896 end Resolve_Op_Expon;
7898 --------------------
7899 -- Resolve_Op_Not --
7900 --------------------
7902 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7905 function Parent_Is_Boolean return Boolean;
7906 -- This function determines if the parent node is a boolean operator or
7907 -- operation (comparison op, membership test, or short circuit form) and
7908 -- the not in question is the left operand of this operation. Note that
7909 -- if the not is in parens, then false is returned.
7911 -----------------------
7912 -- Parent_Is_Boolean --
7913 -----------------------
7915 function Parent_Is_Boolean return Boolean is
7917 if Paren_Count (N) /= 0 then
7921 case Nkind (Parent (N)) is
7936 return Left_Opnd (Parent (N)) = N;
7942 end Parent_Is_Boolean;
7944 -- Start of processing for Resolve_Op_Not
7947 -- Predefined operations on scalar types yield the base type. On the
7948 -- other hand, logical operations on arrays yield the type of the
7949 -- arguments (and the context).
7951 if Is_Array_Type (Typ) then
7954 B_Typ := Base_Type (Typ);
7957 if Is_VMS_Operator (Entity (N)) then
7960 -- Straightforward case of incorrect arguments
7962 elsif not Valid_Boolean_Arg (Typ) then
7963 Error_Msg_N ("invalid operand type for operator&", N);
7964 Set_Etype (N, Any_Type);
7967 -- Special case of probable missing parens
7969 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7970 if Parent_Is_Boolean then
7972 ("operand of not must be enclosed in parentheses",
7976 ("no modular type available in this context", N);
7979 Set_Etype (N, Any_Type);
7982 -- OK resolution of NOT
7985 -- Warn if non-boolean types involved. This is a case like not a < b
7986 -- where a and b are modular, where we will get (not a) < b and most
7987 -- likely not (a < b) was intended.
7989 if Warn_On_Questionable_Missing_Parens
7990 and then not Is_Boolean_Type (Typ)
7991 and then Parent_Is_Boolean
7993 Error_Msg_N ("?not expression should be parenthesized here!", N);
7996 -- Warn on double negation if checking redundant constructs
7998 if Warn_On_Redundant_Constructs
7999 and then Comes_From_Source (N)
8000 and then Comes_From_Source (Right_Opnd (N))
8001 and then Root_Type (Typ) = Standard_Boolean
8002 and then Nkind (Right_Opnd (N)) = N_Op_Not
8004 Error_Msg_N ("redundant double negation?", N);
8007 -- Complete resolution and evaluation of NOT
8009 Resolve (Right_Opnd (N), B_Typ);
8010 Check_Unset_Reference (Right_Opnd (N));
8011 Set_Etype (N, B_Typ);
8012 Generate_Operator_Reference (N, B_Typ);
8017 -----------------------------
8018 -- Resolve_Operator_Symbol --
8019 -----------------------------
8021 -- Nothing to be done, all resolved already
8023 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
8024 pragma Warnings (Off, N);
8025 pragma Warnings (Off, Typ);
8029 end Resolve_Operator_Symbol;
8031 ----------------------------------
8032 -- Resolve_Qualified_Expression --
8033 ----------------------------------
8035 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
8036 pragma Warnings (Off, Typ);
8038 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
8039 Expr : constant Node_Id := Expression (N);
8042 Resolve (Expr, Target_Typ);
8044 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8045 -- operation if not needed.
8047 if Restriction_Check_Required (SPARK)
8048 and then Is_Array_Type (Target_Typ)
8049 and then Is_Array_Type (Etype (Expr))
8050 and then Etype (Expr) /= Any_Composite -- or else Expr in error
8051 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
8053 Check_SPARK_Restriction
8054 ("array types should have matching static bounds", N);
8057 -- A qualified expression requires an exact match of the type, class-
8058 -- wide matching is not allowed. However, if the qualifying type is
8059 -- specific and the expression has a class-wide type, it may still be
8060 -- okay, since it can be the result of the expansion of a call to a
8061 -- dispatching function, so we also have to check class-wideness of the
8062 -- type of the expression's original node.
8064 if (Is_Class_Wide_Type (Target_Typ)
8066 (Is_Class_Wide_Type (Etype (Expr))
8067 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
8068 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
8070 Wrong_Type (Expr, Target_Typ);
8073 -- If the target type is unconstrained, then we reset the type of the
8074 -- result from the type of the expression. For other cases, the actual
8075 -- subtype of the expression is the target type.
8077 if Is_Composite_Type (Target_Typ)
8078 and then not Is_Constrained (Target_Typ)
8080 Set_Etype (N, Etype (Expr));
8083 Eval_Qualified_Expression (N);
8084 end Resolve_Qualified_Expression;
8086 -----------------------------------
8087 -- Resolve_Quantified_Expression --
8088 -----------------------------------
8090 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id) is
8092 if not Alfa_Mode then
8094 -- If expansion is enabled, analysis is delayed until the expresssion
8095 -- is rewritten as a loop.
8097 if Operating_Mode /= Check_Semantics then
8101 -- The loop structure is already resolved during its analysis, only
8102 -- the resolution of the condition needs to be done. Expansion is
8103 -- disabled so that checks and other generated code are inserted in
8104 -- the tree after expression has been rewritten as a loop.
8106 Expander_Mode_Save_And_Set (False);
8107 Resolve (Condition (N), Typ);
8108 Expander_Mode_Restore;
8110 -- In Alfa mode, we need normal expansion in order to properly introduce
8111 -- the necessary transient scopes.
8114 Resolve (Condition (N), Typ);
8116 end Resolve_Quantified_Expression;
8122 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
8123 L : constant Node_Id := Low_Bound (N);
8124 H : constant Node_Id := High_Bound (N);
8126 function First_Last_Ref return Boolean;
8127 -- Returns True if N is of the form X'First .. X'Last where X is the
8128 -- same entity for both attributes.
8130 --------------------
8131 -- First_Last_Ref --
8132 --------------------
8134 function First_Last_Ref return Boolean is
8135 Lorig : constant Node_Id := Original_Node (L);
8136 Horig : constant Node_Id := Original_Node (H);
8139 if Nkind (Lorig) = N_Attribute_Reference
8140 and then Nkind (Horig) = N_Attribute_Reference
8141 and then Attribute_Name (Lorig) = Name_First
8142 and then Attribute_Name (Horig) = Name_Last
8145 PL : constant Node_Id := Prefix (Lorig);
8146 PH : constant Node_Id := Prefix (Horig);
8148 if Is_Entity_Name (PL)
8149 and then Is_Entity_Name (PH)
8150 and then Entity (PL) = Entity (PH)
8160 -- Start of processing for Resolve_Range
8167 -- Check for inappropriate range on unordered enumeration type
8169 if Bad_Unordered_Enumeration_Reference (N, Typ)
8171 -- Exclude X'First .. X'Last if X is the same entity for both
8173 and then not First_Last_Ref
8175 Error_Msg ("subrange of unordered enumeration type?", Sloc (N));
8178 Check_Unset_Reference (L);
8179 Check_Unset_Reference (H);
8181 -- We have to check the bounds for being within the base range as
8182 -- required for a non-static context. Normally this is automatic and
8183 -- done as part of evaluating expressions, but the N_Range node is an
8184 -- exception, since in GNAT we consider this node to be a subexpression,
8185 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8186 -- this, but that would put the test on the main evaluation path for
8189 Check_Non_Static_Context (L);
8190 Check_Non_Static_Context (H);
8192 -- Check for an ambiguous range over character literals. This will
8193 -- happen with a membership test involving only literals.
8195 if Typ = Any_Character then
8196 Ambiguous_Character (L);
8197 Set_Etype (N, Any_Type);
8201 -- If bounds are static, constant-fold them, so size computations are
8202 -- identical between front-end and back-end. Do not perform this
8203 -- transformation while analyzing generic units, as type information
8204 -- would be lost when reanalyzing the constant node in the instance.
8206 if Is_Discrete_Type (Typ) and then Full_Expander_Active then
8207 if Is_OK_Static_Expression (L) then
8208 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8211 if Is_OK_Static_Expression (H) then
8212 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8217 --------------------------
8218 -- Resolve_Real_Literal --
8219 --------------------------
8221 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8222 Actual_Typ : constant Entity_Id := Etype (N);
8225 -- Special processing for fixed-point literals to make sure that the
8226 -- value is an exact multiple of small where this is required. We skip
8227 -- this for the universal real case, and also for generic types.
8229 if Is_Fixed_Point_Type (Typ)
8230 and then Typ /= Universal_Fixed
8231 and then Typ /= Any_Fixed
8232 and then not Is_Generic_Type (Typ)
8235 Val : constant Ureal := Realval (N);
8236 Cintr : constant Ureal := Val / Small_Value (Typ);
8237 Cint : constant Uint := UR_Trunc (Cintr);
8238 Den : constant Uint := Norm_Den (Cintr);
8242 -- Case of literal is not an exact multiple of the Small
8246 -- For a source program literal for a decimal fixed-point type,
8247 -- this is statically illegal (RM 4.9(36)).
8249 if Is_Decimal_Fixed_Point_Type (Typ)
8250 and then Actual_Typ = Universal_Real
8251 and then Comes_From_Source (N)
8253 Error_Msg_N ("value has extraneous low order digits", N);
8256 -- Generate a warning if literal from source
8258 if Is_Static_Expression (N)
8259 and then Warn_On_Bad_Fixed_Value
8262 ("?static fixed-point value is not a multiple of Small!",
8266 -- Replace literal by a value that is the exact representation
8267 -- of a value of the type, i.e. a multiple of the small value,
8268 -- by truncation, since Machine_Rounds is false for all GNAT
8269 -- fixed-point types (RM 4.9(38)).
8271 Stat := Is_Static_Expression (N);
8273 Make_Real_Literal (Sloc (N),
8274 Realval => Small_Value (Typ) * Cint));
8276 Set_Is_Static_Expression (N, Stat);
8279 -- In all cases, set the corresponding integer field
8281 Set_Corresponding_Integer_Value (N, Cint);
8285 -- Now replace the actual type by the expected type as usual
8288 Eval_Real_Literal (N);
8289 end Resolve_Real_Literal;
8291 -----------------------
8292 -- Resolve_Reference --
8293 -----------------------
8295 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
8296 P : constant Node_Id := Prefix (N);
8299 -- Replace general access with specific type
8301 if Ekind (Etype (N)) = E_Allocator_Type then
8302 Set_Etype (N, Base_Type (Typ));
8305 Resolve (P, Designated_Type (Etype (N)));
8307 -- If we are taking the reference of a volatile entity, then treat it as
8308 -- a potential modification of this entity. This is too conservative,
8309 -- but necessary because remove side effects can cause transformations
8310 -- of normal assignments into reference sequences that otherwise fail to
8311 -- notice the modification.
8313 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
8314 Note_Possible_Modification (P, Sure => False);
8316 end Resolve_Reference;
8318 --------------------------------
8319 -- Resolve_Selected_Component --
8320 --------------------------------
8322 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
8324 Comp1 : Entity_Id := Empty; -- prevent junk warning
8325 P : constant Node_Id := Prefix (N);
8326 S : constant Node_Id := Selector_Name (N);
8327 T : Entity_Id := Etype (P);
8329 I1 : Interp_Index := 0; -- prevent junk warning
8334 function Init_Component return Boolean;
8335 -- Check whether this is the initialization of a component within an
8336 -- init proc (by assignment or call to another init proc). If true,
8337 -- there is no need for a discriminant check.
8339 --------------------
8340 -- Init_Component --
8341 --------------------
8343 function Init_Component return Boolean is
8345 return Inside_Init_Proc
8346 and then Nkind (Prefix (N)) = N_Identifier
8347 and then Chars (Prefix (N)) = Name_uInit
8348 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
8351 -- Start of processing for Resolve_Selected_Component
8354 if Is_Overloaded (P) then
8356 -- Use the context type to select the prefix that has a selector
8357 -- of the correct name and type.
8360 Get_First_Interp (P, I, It);
8362 Search : while Present (It.Typ) loop
8363 if Is_Access_Type (It.Typ) then
8364 T := Designated_Type (It.Typ);
8369 -- Locate selected component. For a private prefix the selector
8370 -- can denote a discriminant.
8372 if Is_Record_Type (T) or else Is_Private_Type (T) then
8374 -- The visible components of a class-wide type are those of
8377 if Is_Class_Wide_Type (T) then
8381 Comp := First_Entity (T);
8382 while Present (Comp) loop
8383 if Chars (Comp) = Chars (S)
8384 and then Covers (Etype (Comp), Typ)
8393 It := Disambiguate (P, I1, I, Any_Type);
8395 if It = No_Interp then
8397 ("ambiguous prefix for selected component", N);
8404 -- There may be an implicit dereference. Retrieve
8405 -- designated record type.
8407 if Is_Access_Type (It1.Typ) then
8408 T := Designated_Type (It1.Typ);
8413 if Scope (Comp1) /= T then
8415 -- Resolution chooses the new interpretation.
8416 -- Find the component with the right name.
8418 Comp1 := First_Entity (T);
8419 while Present (Comp1)
8420 and then Chars (Comp1) /= Chars (S)
8422 Comp1 := Next_Entity (Comp1);
8431 Comp := Next_Entity (Comp);
8435 Get_Next_Interp (I, It);
8438 Resolve (P, It1.Typ);
8440 Set_Entity_With_Style_Check (S, Comp1);
8443 -- Resolve prefix with its type
8448 -- Generate cross-reference. We needed to wait until full overloading
8449 -- resolution was complete to do this, since otherwise we can't tell if
8450 -- we are an lvalue or not.
8452 if May_Be_Lvalue (N) then
8453 Generate_Reference (Entity (S), S, 'm');
8455 Generate_Reference (Entity (S), S, 'r');
8458 -- If prefix is an access type, the node will be transformed into an
8459 -- explicit dereference during expansion. The type of the node is the
8460 -- designated type of that of the prefix.
8462 if Is_Access_Type (Etype (P)) then
8463 T := Designated_Type (Etype (P));
8464 Check_Fully_Declared_Prefix (T, P);
8469 if Has_Discriminants (T)
8470 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
8471 and then Present (Original_Record_Component (Entity (S)))
8472 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
8473 and then Present (Discriminant_Checking_Func
8474 (Original_Record_Component (Entity (S))))
8475 and then not Discriminant_Checks_Suppressed (T)
8476 and then not Init_Component
8478 Set_Do_Discriminant_Check (N);
8481 if Ekind (Entity (S)) = E_Void then
8482 Error_Msg_N ("premature use of component", S);
8485 -- If the prefix is a record conversion, this may be a renamed
8486 -- discriminant whose bounds differ from those of the original
8487 -- one, so we must ensure that a range check is performed.
8489 if Nkind (P) = N_Type_Conversion
8490 and then Ekind (Entity (S)) = E_Discriminant
8491 and then Is_Discrete_Type (Typ)
8493 Set_Etype (N, Base_Type (Typ));
8496 -- Note: No Eval processing is required, because the prefix is of a
8497 -- record type, or protected type, and neither can possibly be static.
8499 -- If the array type is atomic, and is packed, and we are in a left side
8500 -- context, then this is worth a warning, since we have a situation
8501 -- where the access to the component may cause extra read/writes of the
8502 -- atomic array object, which could be considered unexpected.
8504 if Nkind (N) = N_Selected_Component
8505 and then (Is_Atomic (T)
8506 or else (Is_Entity_Name (Prefix (N))
8507 and then Is_Atomic (Entity (Prefix (N)))))
8508 and then Is_Packed (T)
8511 Error_Msg_N ("?assignment to component of packed atomic record",
8513 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
8516 end Resolve_Selected_Component;
8522 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
8523 B_Typ : constant Entity_Id := Base_Type (Typ);
8524 L : constant Node_Id := Left_Opnd (N);
8525 R : constant Node_Id := Right_Opnd (N);
8528 -- We do the resolution using the base type, because intermediate values
8529 -- in expressions always are of the base type, not a subtype of it.
8532 Resolve (R, Standard_Natural);
8534 Check_Unset_Reference (L);
8535 Check_Unset_Reference (R);
8537 Set_Etype (N, B_Typ);
8538 Generate_Operator_Reference (N, B_Typ);
8542 ---------------------------
8543 -- Resolve_Short_Circuit --
8544 ---------------------------
8546 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
8547 B_Typ : constant Entity_Id := Base_Type (Typ);
8548 L : constant Node_Id := Left_Opnd (N);
8549 R : constant Node_Id := Right_Opnd (N);
8555 -- Check for issuing warning for always False assert/check, this happens
8556 -- when assertions are turned off, in which case the pragma Assert/Check
8557 -- was transformed into:
8559 -- if False and then <condition> then ...
8561 -- and we detect this pattern
8563 if Warn_On_Assertion_Failure
8564 and then Is_Entity_Name (R)
8565 and then Entity (R) = Standard_False
8566 and then Nkind (Parent (N)) = N_If_Statement
8567 and then Nkind (N) = N_And_Then
8568 and then Is_Entity_Name (L)
8569 and then Entity (L) = Standard_False
8572 Orig : constant Node_Id := Original_Node (Parent (N));
8575 if Nkind (Orig) = N_Pragma
8576 and then Pragma_Name (Orig) = Name_Assert
8578 -- Don't want to warn if original condition is explicit False
8581 Expr : constant Node_Id :=
8584 (First (Pragma_Argument_Associations (Orig))));
8586 if Is_Entity_Name (Expr)
8587 and then Entity (Expr) = Standard_False
8591 -- Issue warning. We do not want the deletion of the
8592 -- IF/AND-THEN to take this message with it. We achieve
8593 -- this by making sure that the expanded code points to
8594 -- the Sloc of the expression, not the original pragma.
8597 ("?assertion would fail at run time!",
8599 (First (Pragma_Argument_Associations (Orig))));
8603 -- Similar processing for Check pragma
8605 elsif Nkind (Orig) = N_Pragma
8606 and then Pragma_Name (Orig) = Name_Check
8608 -- Don't want to warn if original condition is explicit False
8611 Expr : constant Node_Id :=
8615 (Pragma_Argument_Associations (Orig)))));
8617 if Is_Entity_Name (Expr)
8618 and then Entity (Expr) = Standard_False
8623 ("?check would fail at run time!",
8625 (Last (Pragma_Argument_Associations (Orig))));
8632 -- Continue with processing of short circuit
8634 Check_Unset_Reference (L);
8635 Check_Unset_Reference (R);
8637 Set_Etype (N, B_Typ);
8638 Eval_Short_Circuit (N);
8639 end Resolve_Short_Circuit;
8645 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
8646 Name : constant Node_Id := Prefix (N);
8647 Drange : constant Node_Id := Discrete_Range (N);
8648 Array_Type : Entity_Id := Empty;
8652 if Is_Overloaded (Name) then
8654 -- Use the context type to select the prefix that yields the correct
8659 I1 : Interp_Index := 0;
8661 P : constant Node_Id := Prefix (N);
8662 Found : Boolean := False;
8665 Get_First_Interp (P, I, It);
8666 while Present (It.Typ) loop
8667 if (Is_Array_Type (It.Typ)
8668 and then Covers (Typ, It.Typ))
8669 or else (Is_Access_Type (It.Typ)
8670 and then Is_Array_Type (Designated_Type (It.Typ))
8671 and then Covers (Typ, Designated_Type (It.Typ)))
8674 It := Disambiguate (P, I1, I, Any_Type);
8676 if It = No_Interp then
8677 Error_Msg_N ("ambiguous prefix for slicing", N);
8682 Array_Type := It.Typ;
8687 Array_Type := It.Typ;
8692 Get_Next_Interp (I, It);
8697 Array_Type := Etype (Name);
8700 Resolve (Name, Array_Type);
8702 if Is_Access_Type (Array_Type) then
8703 Apply_Access_Check (N);
8704 Array_Type := Designated_Type (Array_Type);
8706 -- If the prefix is an access to an unconstrained array, we must use
8707 -- the actual subtype of the object to perform the index checks. The
8708 -- object denoted by the prefix is implicit in the node, so we build
8709 -- an explicit representation for it in order to compute the actual
8712 if not Is_Constrained (Array_Type) then
8713 Remove_Side_Effects (Prefix (N));
8716 Obj : constant Node_Id :=
8717 Make_Explicit_Dereference (Sloc (N),
8718 Prefix => New_Copy_Tree (Prefix (N)));
8720 Set_Etype (Obj, Array_Type);
8721 Set_Parent (Obj, Parent (N));
8722 Array_Type := Get_Actual_Subtype (Obj);
8726 elsif Is_Entity_Name (Name)
8727 or else Nkind (Name) = N_Explicit_Dereference
8728 or else (Nkind (Name) = N_Function_Call
8729 and then not Is_Constrained (Etype (Name)))
8731 Array_Type := Get_Actual_Subtype (Name);
8733 -- If the name is a selected component that depends on discriminants,
8734 -- build an actual subtype for it. This can happen only when the name
8735 -- itself is overloaded; otherwise the actual subtype is created when
8736 -- the selected component is analyzed.
8738 elsif Nkind (Name) = N_Selected_Component
8739 and then Full_Analysis
8740 and then Depends_On_Discriminant (First_Index (Array_Type))
8743 Act_Decl : constant Node_Id :=
8744 Build_Actual_Subtype_Of_Component (Array_Type, Name);
8746 Insert_Action (N, Act_Decl);
8747 Array_Type := Defining_Identifier (Act_Decl);
8750 -- Maybe this should just be "else", instead of checking for the
8751 -- specific case of slice??? This is needed for the case where the
8752 -- prefix is an Image attribute, which gets expanded to a slice, and so
8753 -- has a constrained subtype which we want to use for the slice range
8754 -- check applied below (the range check won't get done if the
8755 -- unconstrained subtype of the 'Image is used).
8757 elsif Nkind (Name) = N_Slice then
8758 Array_Type := Etype (Name);
8761 -- If name was overloaded, set slice type correctly now
8763 Set_Etype (N, Array_Type);
8765 -- If the range is specified by a subtype mark, no resolution is
8766 -- necessary. Else resolve the bounds, and apply needed checks.
8768 if not Is_Entity_Name (Drange) then
8769 Index := First_Index (Array_Type);
8770 Resolve (Drange, Base_Type (Etype (Index)));
8772 if Nkind (Drange) = N_Range then
8774 -- Ensure that side effects in the bounds are properly handled
8776 Force_Evaluation (Low_Bound (Drange));
8777 Force_Evaluation (High_Bound (Drange));
8779 -- Do not apply the range check to nodes associated with the
8780 -- frontend expansion of the dispatch table. We first check
8781 -- if Ada.Tags is already loaded to avoid the addition of an
8782 -- undesired dependence on such run-time unit.
8784 if not Tagged_Type_Expansion
8786 (RTU_Loaded (Ada_Tags)
8787 and then Nkind (Prefix (N)) = N_Selected_Component
8788 and then Present (Entity (Selector_Name (Prefix (N))))
8789 and then Entity (Selector_Name (Prefix (N))) =
8790 RTE_Record_Component (RE_Prims_Ptr))
8792 Apply_Range_Check (Drange, Etype (Index));
8797 Set_Slice_Subtype (N);
8799 -- Check bad use of type with predicates
8801 if Has_Predicates (Etype (Drange)) then
8802 Bad_Predicated_Subtype_Use
8803 ("subtype& has predicate, not allowed in slice",
8804 Drange, Etype (Drange));
8806 -- Otherwise here is where we check suspicious indexes
8808 elsif Nkind (Drange) = N_Range then
8809 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8810 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8816 ----------------------------
8817 -- Resolve_String_Literal --
8818 ----------------------------
8820 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8821 C_Typ : constant Entity_Id := Component_Type (Typ);
8822 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8823 Loc : constant Source_Ptr := Sloc (N);
8824 Str : constant String_Id := Strval (N);
8825 Strlen : constant Nat := String_Length (Str);
8826 Subtype_Id : Entity_Id;
8827 Need_Check : Boolean;
8830 -- For a string appearing in a concatenation, defer creation of the
8831 -- string_literal_subtype until the end of the resolution of the
8832 -- concatenation, because the literal may be constant-folded away. This
8833 -- is a useful optimization for long concatenation expressions.
8835 -- If the string is an aggregate built for a single character (which
8836 -- happens in a non-static context) or a is null string to which special
8837 -- checks may apply, we build the subtype. Wide strings must also get a
8838 -- string subtype if they come from a one character aggregate. Strings
8839 -- generated by attributes might be static, but it is often hard to
8840 -- determine whether the enclosing context is static, so we generate
8841 -- subtypes for them as well, thus losing some rarer optimizations ???
8842 -- Same for strings that come from a static conversion.
8845 (Strlen = 0 and then Typ /= Standard_String)
8846 or else Nkind (Parent (N)) /= N_Op_Concat
8847 or else (N /= Left_Opnd (Parent (N))
8848 and then N /= Right_Opnd (Parent (N)))
8849 or else ((Typ = Standard_Wide_String
8850 or else Typ = Standard_Wide_Wide_String)
8851 and then Nkind (Original_Node (N)) /= N_String_Literal);
8853 -- If the resolving type is itself a string literal subtype, we can just
8854 -- reuse it, since there is no point in creating another.
8856 if Ekind (Typ) = E_String_Literal_Subtype then
8859 elsif Nkind (Parent (N)) = N_Op_Concat
8860 and then not Need_Check
8861 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8862 N_Attribute_Reference,
8863 N_Qualified_Expression,
8868 -- Otherwise we must create a string literal subtype. Note that the
8869 -- whole idea of string literal subtypes is simply to avoid the need
8870 -- for building a full fledged array subtype for each literal.
8873 Set_String_Literal_Subtype (N, Typ);
8874 Subtype_Id := Etype (N);
8877 if Nkind (Parent (N)) /= N_Op_Concat
8880 Set_Etype (N, Subtype_Id);
8881 Eval_String_Literal (N);
8884 if Is_Limited_Composite (Typ)
8885 or else Is_Private_Composite (Typ)
8887 Error_Msg_N ("string literal not available for private array", N);
8888 Set_Etype (N, Any_Type);
8892 -- The validity of a null string has been checked in the call to
8893 -- Eval_String_Literal.
8898 -- Always accept string literal with component type Any_Character, which
8899 -- occurs in error situations and in comparisons of literals, both of
8900 -- which should accept all literals.
8902 elsif R_Typ = Any_Character then
8905 -- If the type is bit-packed, then we always transform the string
8906 -- literal into a full fledged aggregate.
8908 elsif Is_Bit_Packed_Array (Typ) then
8911 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8914 -- For Standard.Wide_Wide_String, or any other type whose component
8915 -- type is Standard.Wide_Wide_Character, we know that all the
8916 -- characters in the string must be acceptable, since the parser
8917 -- accepted the characters as valid character literals.
8919 if R_Typ = Standard_Wide_Wide_Character then
8922 -- For the case of Standard.String, or any other type whose component
8923 -- type is Standard.Character, we must make sure that there are no
8924 -- wide characters in the string, i.e. that it is entirely composed
8925 -- of characters in range of type Character.
8927 -- If the string literal is the result of a static concatenation, the
8928 -- test has already been performed on the components, and need not be
8931 elsif R_Typ = Standard_Character
8932 and then Nkind (Original_Node (N)) /= N_Op_Concat
8934 for J in 1 .. Strlen loop
8935 if not In_Character_Range (Get_String_Char (Str, J)) then
8937 -- If we are out of range, post error. This is one of the
8938 -- very few places that we place the flag in the middle of
8939 -- a token, right under the offending wide character. Not
8940 -- quite clear if this is right wrt wide character encoding
8941 -- sequences, but it's only an error message!
8944 ("literal out of range of type Standard.Character",
8945 Source_Ptr (Int (Loc) + J));
8950 -- For the case of Standard.Wide_String, or any other type whose
8951 -- component type is Standard.Wide_Character, we must make sure that
8952 -- there are no wide characters in the string, i.e. that it is
8953 -- entirely composed of characters in range of type Wide_Character.
8955 -- If the string literal is the result of a static concatenation,
8956 -- the test has already been performed on the components, and need
8959 elsif R_Typ = Standard_Wide_Character
8960 and then Nkind (Original_Node (N)) /= N_Op_Concat
8962 for J in 1 .. Strlen loop
8963 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8965 -- If we are out of range, post error. This is one of the
8966 -- very few places that we place the flag in the middle of
8967 -- a token, right under the offending wide character.
8969 -- This is not quite right, because characters in general
8970 -- will take more than one character position ???
8973 ("literal out of range of type Standard.Wide_Character",
8974 Source_Ptr (Int (Loc) + J));
8979 -- If the root type is not a standard character, then we will convert
8980 -- the string into an aggregate and will let the aggregate code do
8981 -- the checking. Standard Wide_Wide_Character is also OK here.
8987 -- See if the component type of the array corresponding to the string
8988 -- has compile time known bounds. If yes we can directly check
8989 -- whether the evaluation of the string will raise constraint error.
8990 -- Otherwise we need to transform the string literal into the
8991 -- corresponding character aggregate and let the aggregate code do
8994 if Is_Standard_Character_Type (R_Typ) then
8996 -- Check for the case of full range, where we are definitely OK
8998 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
9002 -- Here the range is not the complete base type range, so check
9005 Comp_Typ_Lo : constant Node_Id :=
9006 Type_Low_Bound (Component_Type (Typ));
9007 Comp_Typ_Hi : constant Node_Id :=
9008 Type_High_Bound (Component_Type (Typ));
9013 if Compile_Time_Known_Value (Comp_Typ_Lo)
9014 and then Compile_Time_Known_Value (Comp_Typ_Hi)
9016 for J in 1 .. Strlen loop
9017 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
9019 if Char_Val < Expr_Value (Comp_Typ_Lo)
9020 or else Char_Val > Expr_Value (Comp_Typ_Hi)
9022 Apply_Compile_Time_Constraint_Error
9023 (N, "character out of range?", CE_Range_Check_Failed,
9024 Loc => Source_Ptr (Int (Loc) + J));
9034 -- If we got here we meed to transform the string literal into the
9035 -- equivalent qualified positional array aggregate. This is rather
9036 -- heavy artillery for this situation, but it is hard work to avoid.
9039 Lits : constant List_Id := New_List;
9040 P : Source_Ptr := Loc + 1;
9044 -- Build the character literals, we give them source locations that
9045 -- correspond to the string positions, which is a bit tricky given
9046 -- the possible presence of wide character escape sequences.
9048 for J in 1 .. Strlen loop
9049 C := Get_String_Char (Str, J);
9050 Set_Character_Literal_Name (C);
9053 Make_Character_Literal (P,
9055 Char_Literal_Value => UI_From_CC (C)));
9057 if In_Character_Range (C) then
9060 -- Should we have a call to Skip_Wide here ???
9069 Make_Qualified_Expression (Loc,
9070 Subtype_Mark => New_Reference_To (Typ, Loc),
9072 Make_Aggregate (Loc, Expressions => Lits)));
9074 Analyze_And_Resolve (N, Typ);
9076 end Resolve_String_Literal;
9078 -----------------------------
9079 -- Resolve_Subprogram_Info --
9080 -----------------------------
9082 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
9085 end Resolve_Subprogram_Info;
9087 -----------------------------
9088 -- Resolve_Type_Conversion --
9089 -----------------------------
9091 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
9092 Conv_OK : constant Boolean := Conversion_OK (N);
9093 Operand : constant Node_Id := Expression (N);
9094 Operand_Typ : constant Entity_Id := Etype (Operand);
9095 Target_Typ : constant Entity_Id := Etype (N);
9100 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
9101 -- Set to False to suppress cases where we want to suppress the test
9102 -- for redundancy to avoid possible false positives on this warning.
9106 and then not Valid_Conversion (N, Target_Typ, Operand)
9111 -- If the Operand Etype is Universal_Fixed, then the conversion is
9112 -- never redundant. We need this check because by the time we have
9113 -- finished the rather complex transformation, the conversion looks
9114 -- redundant when it is not.
9116 if Operand_Typ = Universal_Fixed then
9117 Test_Redundant := False;
9119 -- If the operand is marked as Any_Fixed, then special processing is
9120 -- required. This is also a case where we suppress the test for a
9121 -- redundant conversion, since most certainly it is not redundant.
9123 elsif Operand_Typ = Any_Fixed then
9124 Test_Redundant := False;
9126 -- Mixed-mode operation involving a literal. Context must be a fixed
9127 -- type which is applied to the literal subsequently.
9129 if Is_Fixed_Point_Type (Typ) then
9130 Set_Etype (Operand, Universal_Real);
9132 elsif Is_Numeric_Type (Typ)
9133 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
9134 and then (Etype (Right_Opnd (Operand)) = Universal_Real
9136 Etype (Left_Opnd (Operand)) = Universal_Real)
9138 -- Return if expression is ambiguous
9140 if Unique_Fixed_Point_Type (N) = Any_Type then
9143 -- If nothing else, the available fixed type is Duration
9146 Set_Etype (Operand, Standard_Duration);
9149 -- Resolve the real operand with largest available precision
9151 if Etype (Right_Opnd (Operand)) = Universal_Real then
9152 Rop := New_Copy_Tree (Right_Opnd (Operand));
9154 Rop := New_Copy_Tree (Left_Opnd (Operand));
9157 Resolve (Rop, Universal_Real);
9159 -- If the operand is a literal (it could be a non-static and
9160 -- illegal exponentiation) check whether the use of Duration
9161 -- is potentially inaccurate.
9163 if Nkind (Rop) = N_Real_Literal
9164 and then Realval (Rop) /= Ureal_0
9165 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9168 ("?universal real operand can only " &
9169 "be interpreted as Duration!",
9172 ("\?precision will be lost in the conversion!", Rop);
9175 elsif Is_Numeric_Type (Typ)
9176 and then Nkind (Operand) in N_Op
9177 and then Unique_Fixed_Point_Type (N) /= Any_Type
9179 Set_Etype (Operand, Standard_Duration);
9182 Error_Msg_N ("invalid context for mixed mode operation", N);
9183 Set_Etype (Operand, Any_Type);
9190 -- In SPARK, a type conversion between array types should be restricted
9191 -- to types which have matching static bounds.
9193 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9194 -- operation if not needed.
9196 if Restriction_Check_Required (SPARK)
9197 and then Is_Array_Type (Target_Typ)
9198 and then Is_Array_Type (Operand_Typ)
9199 and then Operand_Typ /= Any_Composite -- or else Operand in error
9200 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
9202 Check_SPARK_Restriction
9203 ("array types should have matching static bounds", N);
9206 -- In formal mode, the operand of an ancestor type conversion must be an
9207 -- object (not an expression).
9209 if Is_Tagged_Type (Target_Typ)
9210 and then not Is_Class_Wide_Type (Target_Typ)
9211 and then Is_Tagged_Type (Operand_Typ)
9212 and then not Is_Class_Wide_Type (Operand_Typ)
9213 and then Is_Ancestor (Target_Typ, Operand_Typ)
9214 and then not Is_SPARK_Object_Reference (Operand)
9216 Check_SPARK_Restriction ("object required", Operand);
9219 -- Note: we do the Eval_Type_Conversion call before applying the
9220 -- required checks for a subtype conversion. This is important, since
9221 -- both are prepared under certain circumstances to change the type
9222 -- conversion to a constraint error node, but in the case of
9223 -- Eval_Type_Conversion this may reflect an illegality in the static
9224 -- case, and we would miss the illegality (getting only a warning
9225 -- message), if we applied the type conversion checks first.
9227 Eval_Type_Conversion (N);
9229 -- Even when evaluation is not possible, we may be able to simplify the
9230 -- conversion or its expression. This needs to be done before applying
9231 -- checks, since otherwise the checks may use the original expression
9232 -- and defeat the simplifications. This is specifically the case for
9233 -- elimination of the floating-point Truncation attribute in
9234 -- float-to-int conversions.
9236 Simplify_Type_Conversion (N);
9238 -- If after evaluation we still have a type conversion, then we may need
9239 -- to apply checks required for a subtype conversion.
9241 -- Skip these type conversion checks if universal fixed operands
9242 -- operands involved, since range checks are handled separately for
9243 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9245 if Nkind (N) = N_Type_Conversion
9246 and then not Is_Generic_Type (Root_Type (Target_Typ))
9247 and then Target_Typ /= Universal_Fixed
9248 and then Operand_Typ /= Universal_Fixed
9250 Apply_Type_Conversion_Checks (N);
9253 -- Issue warning for conversion of simple object to its own type. We
9254 -- have to test the original nodes, since they may have been rewritten
9255 -- by various optimizations.
9257 Orig_N := Original_Node (N);
9259 -- Here we test for a redundant conversion if the warning mode is
9260 -- active (and was not locally reset), and we have a type conversion
9261 -- from source not appearing in a generic instance.
9264 and then Nkind (Orig_N) = N_Type_Conversion
9265 and then Comes_From_Source (Orig_N)
9266 and then not In_Instance
9268 Orig_N := Original_Node (Expression (Orig_N));
9269 Orig_T := Target_Typ;
9271 -- If the node is part of a larger expression, the Target_Type
9272 -- may not be the original type of the node if the context is a
9273 -- condition. Recover original type to see if conversion is needed.
9275 if Is_Boolean_Type (Orig_T)
9276 and then Nkind (Parent (N)) in N_Op
9278 Orig_T := Etype (Parent (N));
9281 -- If we have an entity name, then give the warning if the entity
9282 -- is the right type, or if it is a loop parameter covered by the
9283 -- original type (that's needed because loop parameters have an
9284 -- odd subtype coming from the bounds).
9286 if (Is_Entity_Name (Orig_N)
9288 (Etype (Entity (Orig_N)) = Orig_T
9290 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
9291 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
9293 -- If not an entity, then type of expression must match
9295 or else Etype (Orig_N) = Orig_T
9297 -- One more check, do not give warning if the analyzed conversion
9298 -- has an expression with non-static bounds, and the bounds of the
9299 -- target are static. This avoids junk warnings in cases where the
9300 -- conversion is necessary to establish staticness, for example in
9301 -- a case statement.
9303 if not Is_OK_Static_Subtype (Operand_Typ)
9304 and then Is_OK_Static_Subtype (Target_Typ)
9308 -- Finally, if this type conversion occurs in a context requiring
9309 -- a prefix, and the expression is a qualified expression then the
9310 -- type conversion is not redundant, since a qualified expression
9311 -- is not a prefix, whereas a type conversion is. For example, "X
9312 -- := T'(Funx(...)).Y;" is illegal because a selected component
9313 -- requires a prefix, but a type conversion makes it legal: "X :=
9314 -- T(T'(Funx(...))).Y;"
9316 -- In Ada 2012, a qualified expression is a name, so this idiom is
9317 -- no longer needed, but we still suppress the warning because it
9318 -- seems unfriendly for warnings to pop up when you switch to the
9319 -- newer language version.
9321 elsif Nkind (Orig_N) = N_Qualified_Expression
9322 and then Nkind_In (Parent (N), N_Attribute_Reference,
9323 N_Indexed_Component,
9324 N_Selected_Component,
9326 N_Explicit_Dereference)
9330 -- Here we give the redundant conversion warning. If it is an
9331 -- entity, give the name of the entity in the message. If not,
9332 -- just mention the expression.
9335 if Is_Entity_Name (Orig_N) then
9336 Error_Msg_Node_2 := Orig_T;
9337 Error_Msg_NE -- CODEFIX
9338 ("?redundant conversion, & is of type &!",
9339 N, Entity (Orig_N));
9342 ("?redundant conversion, expression is of type&!",
9349 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
9350 -- No need to perform any interface conversion if the type of the
9351 -- expression coincides with the target type.
9353 if Ada_Version >= Ada_2005
9354 and then Full_Expander_Active
9355 and then Operand_Typ /= Target_Typ
9358 Opnd : Entity_Id := Operand_Typ;
9359 Target : Entity_Id := Target_Typ;
9362 if Is_Access_Type (Opnd) then
9363 Opnd := Designated_Type (Opnd);
9366 if Is_Access_Type (Target_Typ) then
9367 Target := Designated_Type (Target);
9370 if Opnd = Target then
9373 -- Conversion from interface type
9375 elsif Is_Interface (Opnd) then
9377 -- Ada 2005 (AI-217): Handle entities from limited views
9379 if From_With_Type (Opnd) then
9380 Error_Msg_Qual_Level := 99;
9381 Error_Msg_NE -- CODEFIX
9382 ("missing WITH clause on package &", N,
9383 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
9385 ("type conversions require visibility of the full view",
9388 elsif From_With_Type (Target)
9390 (Is_Access_Type (Target_Typ)
9391 and then Present (Non_Limited_View (Etype (Target))))
9393 Error_Msg_Qual_Level := 99;
9394 Error_Msg_NE -- CODEFIX
9395 ("missing WITH clause on package &", N,
9396 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
9398 ("type conversions require visibility of the full view",
9402 Expand_Interface_Conversion (N, Is_Static => False);
9405 -- Conversion to interface type
9407 elsif Is_Interface (Target) then
9411 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
9412 Opnd := Etype (Opnd);
9415 if not Interface_Present_In_Ancestor
9419 if Is_Class_Wide_Type (Opnd) then
9421 -- The static analysis is not enough to know if the
9422 -- interface is implemented or not. Hence we must pass
9423 -- the work to the expander to generate code to evaluate
9424 -- the conversion at run time.
9426 Expand_Interface_Conversion (N, Is_Static => False);
9429 Error_Msg_Name_1 := Chars (Etype (Target));
9430 Error_Msg_Name_2 := Chars (Opnd);
9432 ("wrong interface conversion (% is not a progenitor " &
9437 Expand_Interface_Conversion (N);
9442 end Resolve_Type_Conversion;
9444 ----------------------
9445 -- Resolve_Unary_Op --
9446 ----------------------
9448 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
9449 B_Typ : constant Entity_Id := Base_Type (Typ);
9450 R : constant Node_Id := Right_Opnd (N);
9456 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
9457 Error_Msg_Name_1 := Chars (Typ);
9458 Check_SPARK_Restriction
9459 ("unary operator not defined for modular type%", N);
9462 -- Deal with intrinsic unary operators
9464 if Comes_From_Source (N)
9465 and then Ekind (Entity (N)) = E_Function
9466 and then Is_Imported (Entity (N))
9467 and then Is_Intrinsic_Subprogram (Entity (N))
9469 Resolve_Intrinsic_Unary_Operator (N, Typ);
9473 -- Deal with universal cases
9475 if Etype (R) = Universal_Integer
9477 Etype (R) = Universal_Real
9479 Check_For_Visible_Operator (N, B_Typ);
9482 Set_Etype (N, B_Typ);
9485 -- Generate warning for expressions like abs (x mod 2)
9487 if Warn_On_Redundant_Constructs
9488 and then Nkind (N) = N_Op_Abs
9490 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
9492 if OK and then Hi >= Lo and then Lo >= 0 then
9493 Error_Msg_N -- CODEFIX
9494 ("?abs applied to known non-negative value has no effect", N);
9498 -- Deal with reference generation
9500 Check_Unset_Reference (R);
9501 Generate_Operator_Reference (N, B_Typ);
9504 -- Set overflow checking bit. Much cleverer code needed here eventually
9505 -- and perhaps the Resolve routines should be separated for the various
9506 -- arithmetic operations, since they will need different processing ???
9508 if Nkind (N) in N_Op then
9509 if not Overflow_Checks_Suppressed (Etype (N)) then
9510 Enable_Overflow_Check (N);
9514 -- Generate warning for expressions like -5 mod 3 for integers. No need
9515 -- to worry in the floating-point case, since parens do not affect the
9516 -- result so there is no point in giving in a warning.
9519 Norig : constant Node_Id := Original_Node (N);
9528 if Warn_On_Questionable_Missing_Parens
9529 and then Comes_From_Source (Norig)
9530 and then Is_Integer_Type (Typ)
9531 and then Nkind (Norig) = N_Op_Minus
9533 Rorig := Original_Node (Right_Opnd (Norig));
9535 -- We are looking for cases where the right operand is not
9536 -- parenthesized, and is a binary operator, multiply, divide, or
9537 -- mod. These are the cases where the grouping can affect results.
9539 if Paren_Count (Rorig) = 0
9540 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
9542 -- For mod, we always give the warning, since the value is
9543 -- affected by the parenthesization (e.g. (-5) mod 315 /=
9544 -- -(5 mod 315)). But for the other cases, the only concern is
9545 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
9546 -- overflows, but (-2) * 64 does not). So we try to give the
9547 -- message only when overflow is possible.
9549 if Nkind (Rorig) /= N_Op_Mod
9550 and then Compile_Time_Known_Value (R)
9552 Val := Expr_Value (R);
9554 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
9555 HB := Expr_Value (Type_High_Bound (Typ));
9557 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
9560 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
9561 LB := Expr_Value (Type_Low_Bound (Typ));
9563 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
9566 -- Note that the test below is deliberately excluding the
9567 -- largest negative number, since that is a potentially
9568 -- troublesome case (e.g. -2 * x, where the result is the
9569 -- largest negative integer has an overflow with 2 * x).
9571 if Val > LB and then Val <= HB then
9576 -- For the multiplication case, the only case we have to worry
9577 -- about is when (-a)*b is exactly the largest negative number
9578 -- so that -(a*b) can cause overflow. This can only happen if
9579 -- a is a power of 2, and more generally if any operand is a
9580 -- constant that is not a power of 2, then the parentheses
9581 -- cannot affect whether overflow occurs. We only bother to
9582 -- test the left most operand
9584 -- Loop looking at left operands for one that has known value
9587 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
9588 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
9589 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
9591 -- Operand value of 0 or 1 skips warning
9596 -- Otherwise check power of 2, if power of 2, warn, if
9597 -- anything else, skip warning.
9600 while Lval /= 2 loop
9601 if Lval mod 2 = 1 then
9612 -- Keep looking at left operands
9614 Opnd := Left_Opnd (Opnd);
9617 -- For rem or "/" we can only have a problematic situation
9618 -- if the divisor has a value of minus one or one. Otherwise
9619 -- overflow is impossible (divisor > 1) or we have a case of
9620 -- division by zero in any case.
9622 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
9623 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
9624 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
9629 -- If we fall through warning should be issued
9632 ("?unary minus expression should be parenthesized here!", N);
9636 end Resolve_Unary_Op;
9638 ----------------------------------
9639 -- Resolve_Unchecked_Expression --
9640 ----------------------------------
9642 procedure Resolve_Unchecked_Expression
9647 Resolve (Expression (N), Typ, Suppress => All_Checks);
9649 end Resolve_Unchecked_Expression;
9651 ---------------------------------------
9652 -- Resolve_Unchecked_Type_Conversion --
9653 ---------------------------------------
9655 procedure Resolve_Unchecked_Type_Conversion
9659 pragma Warnings (Off, Typ);
9661 Operand : constant Node_Id := Expression (N);
9662 Opnd_Type : constant Entity_Id := Etype (Operand);
9665 -- Resolve operand using its own type
9667 Resolve (Operand, Opnd_Type);
9668 Eval_Unchecked_Conversion (N);
9669 end Resolve_Unchecked_Type_Conversion;
9671 ------------------------------
9672 -- Rewrite_Operator_As_Call --
9673 ------------------------------
9675 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
9676 Loc : constant Source_Ptr := Sloc (N);
9677 Actuals : constant List_Id := New_List;
9681 if Nkind (N) in N_Binary_Op then
9682 Append (Left_Opnd (N), Actuals);
9685 Append (Right_Opnd (N), Actuals);
9688 Make_Function_Call (Sloc => Loc,
9689 Name => New_Occurrence_Of (Nam, Loc),
9690 Parameter_Associations => Actuals);
9692 Preserve_Comes_From_Source (New_N, N);
9693 Preserve_Comes_From_Source (Name (New_N), N);
9695 Set_Etype (N, Etype (Nam));
9696 end Rewrite_Operator_As_Call;
9698 ------------------------------
9699 -- Rewrite_Renamed_Operator --
9700 ------------------------------
9702 procedure Rewrite_Renamed_Operator
9707 Nam : constant Name_Id := Chars (Op);
9708 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
9712 -- Rewrite the operator node using the real operator, not its renaming.
9713 -- Exclude user-defined intrinsic operations of the same name, which are
9714 -- treated separately and rewritten as calls.
9716 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
9717 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
9718 Set_Chars (Op_Node, Nam);
9719 Set_Etype (Op_Node, Etype (N));
9720 Set_Entity (Op_Node, Op);
9721 Set_Right_Opnd (Op_Node, Right_Opnd (N));
9723 -- Indicate that both the original entity and its renaming are
9724 -- referenced at this point.
9726 Generate_Reference (Entity (N), N);
9727 Generate_Reference (Op, N);
9730 Set_Left_Opnd (Op_Node, Left_Opnd (N));
9733 Rewrite (N, Op_Node);
9735 -- If the context type is private, add the appropriate conversions so
9736 -- that the operator is applied to the full view. This is done in the
9737 -- routines that resolve intrinsic operators.
9739 if Is_Intrinsic_Subprogram (Op)
9740 and then Is_Private_Type (Typ)
9743 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
9744 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
9745 Resolve_Intrinsic_Operator (N, Typ);
9747 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
9748 Resolve_Intrinsic_Unary_Operator (N, Typ);
9755 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
9757 -- Operator renames a user-defined operator of the same name. Use the
9758 -- original operator in the node, which is the one Gigi knows about.
9761 Set_Is_Overloaded (N, False);
9763 end Rewrite_Renamed_Operator;
9765 -----------------------
9766 -- Set_Slice_Subtype --
9767 -----------------------
9769 -- Build an implicit subtype declaration to represent the type delivered by
9770 -- the slice. This is an abbreviated version of an array subtype. We define
9771 -- an index subtype for the slice, using either the subtype name or the
9772 -- discrete range of the slice. To be consistent with index usage elsewhere
9773 -- we create a list header to hold the single index. This list is not
9774 -- otherwise attached to the syntax tree.
9776 procedure Set_Slice_Subtype (N : Node_Id) is
9777 Loc : constant Source_Ptr := Sloc (N);
9778 Index_List : constant List_Id := New_List;
9780 Index_Subtype : Entity_Id;
9781 Index_Type : Entity_Id;
9782 Slice_Subtype : Entity_Id;
9783 Drange : constant Node_Id := Discrete_Range (N);
9786 if Is_Entity_Name (Drange) then
9787 Index_Subtype := Entity (Drange);
9790 -- We force the evaluation of a range. This is definitely needed in
9791 -- the renamed case, and seems safer to do unconditionally. Note in
9792 -- any case that since we will create and insert an Itype referring
9793 -- to this range, we must make sure any side effect removal actions
9794 -- are inserted before the Itype definition.
9796 if Nkind (Drange) = N_Range then
9797 Force_Evaluation (Low_Bound (Drange));
9798 Force_Evaluation (High_Bound (Drange));
9801 Index_Type := Base_Type (Etype (Drange));
9803 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9805 -- Take a new copy of Drange (where bounds have been rewritten to
9806 -- reference side-effect-free names). Using a separate tree ensures
9807 -- that further expansion (e.g. while rewriting a slice assignment
9808 -- into a FOR loop) does not attempt to remove side effects on the
9809 -- bounds again (which would cause the bounds in the index subtype
9810 -- definition to refer to temporaries before they are defined) (the
9811 -- reason is that some names are considered side effect free here
9812 -- for the subtype, but not in the context of a loop iteration
9815 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
9816 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
9817 Set_Etype (Index_Subtype, Index_Type);
9818 Set_Size_Info (Index_Subtype, Index_Type);
9819 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9822 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
9824 Index := New_Occurrence_Of (Index_Subtype, Loc);
9825 Set_Etype (Index, Index_Subtype);
9826 Append (Index, Index_List);
9828 Set_First_Index (Slice_Subtype, Index);
9829 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
9830 Set_Is_Constrained (Slice_Subtype, True);
9832 Check_Compile_Time_Size (Slice_Subtype);
9834 -- The Etype of the existing Slice node is reset to this slice subtype.
9835 -- Its bounds are obtained from its first index.
9837 Set_Etype (N, Slice_Subtype);
9839 -- For packed slice subtypes, freeze immediately (except in the case of
9840 -- being in a "spec expression" where we never freeze when we first see
9843 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
9844 Freeze_Itype (Slice_Subtype, N);
9846 -- For all other cases insert an itype reference in the slice's actions
9847 -- so that the itype is frozen at the proper place in the tree (i.e. at
9848 -- the point where actions for the slice are analyzed). Note that this
9849 -- is different from freezing the itype immediately, which might be
9850 -- premature (e.g. if the slice is within a transient scope). This needs
9851 -- to be done only if expansion is enabled.
9853 elsif Full_Expander_Active then
9854 Ensure_Defined (Typ => Slice_Subtype, N => N);
9856 end Set_Slice_Subtype;
9858 --------------------------------
9859 -- Set_String_Literal_Subtype --
9860 --------------------------------
9862 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
9863 Loc : constant Source_Ptr := Sloc (N);
9864 Low_Bound : constant Node_Id :=
9865 Type_Low_Bound (Etype (First_Index (Typ)));
9866 Subtype_Id : Entity_Id;
9869 if Nkind (N) /= N_String_Literal then
9873 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
9874 Set_String_Literal_Length (Subtype_Id, UI_From_Int
9875 (String_Length (Strval (N))));
9876 Set_Etype (Subtype_Id, Base_Type (Typ));
9877 Set_Is_Constrained (Subtype_Id);
9878 Set_Etype (N, Subtype_Id);
9880 if Is_OK_Static_Expression (Low_Bound) then
9882 -- The low bound is set from the low bound of the corresponding index
9883 -- type. Note that we do not store the high bound in the string literal
9884 -- subtype, but it can be deduced if necessary from the length and the
9887 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
9890 -- If the lower bound is not static we create a range for the string
9891 -- literal, using the index type and the known length of the literal.
9892 -- The index type is not necessarily Positive, so the upper bound is
9893 -- computed as T'Val (T'Pos (Low_Bound) + L - 1)
9896 Index_List : constant List_Id := New_List;
9897 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9899 High_Bound : constant Node_Id :=
9900 Make_Attribute_Reference (Loc,
9901 Attribute_Name => Name_Val,
9903 New_Occurrence_Of (Index_Type, Loc),
9904 Expressions => New_List (
9907 Make_Attribute_Reference (Loc,
9908 Attribute_Name => Name_Pos,
9910 New_Occurrence_Of (Index_Type, Loc),
9912 New_List (New_Copy_Tree (Low_Bound))),
9914 Make_Integer_Literal (Loc,
9915 String_Length (Strval (N)) - 1))));
9917 Array_Subtype : Entity_Id;
9918 Index_Subtype : Entity_Id;
9923 if Is_Integer_Type (Index_Type) then
9924 Set_String_Literal_Low_Bound
9925 (Subtype_Id, Make_Integer_Literal (Loc, 1));
9928 -- If the index type is an enumeration type, build bounds
9929 -- expression with attributes.
9931 Set_String_Literal_Low_Bound
9933 Make_Attribute_Reference (Loc,
9934 Attribute_Name => Name_First,
9936 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
9937 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
9940 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
9942 -- Build bona fide subtype for the string, and wrap it in an
9943 -- unchecked conversion, because the backend expects the
9944 -- String_Literal_Subtype to have a static lower bound.
9947 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9948 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
9949 Set_Scalar_Range (Index_Subtype, Drange);
9950 Set_Parent (Drange, N);
9951 Analyze_And_Resolve (Drange, Index_Type);
9953 -- In the context, the Index_Type may already have a constraint,
9954 -- so use common base type on string subtype. The base type may
9955 -- be used when generating attributes of the string, for example
9956 -- in the context of a slice assignment.
9958 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9959 Set_Size_Info (Index_Subtype, Index_Type);
9960 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9962 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9964 Index := New_Occurrence_Of (Index_Subtype, Loc);
9965 Set_Etype (Index, Index_Subtype);
9966 Append (Index, Index_List);
9968 Set_First_Index (Array_Subtype, Index);
9969 Set_Etype (Array_Subtype, Base_Type (Typ));
9970 Set_Is_Constrained (Array_Subtype, True);
9973 Make_Unchecked_Type_Conversion (Loc,
9974 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9975 Expression => Relocate_Node (N)));
9976 Set_Etype (N, Array_Subtype);
9979 end Set_String_Literal_Subtype;
9981 ------------------------------
9982 -- Simplify_Type_Conversion --
9983 ------------------------------
9985 procedure Simplify_Type_Conversion (N : Node_Id) is
9987 if Nkind (N) = N_Type_Conversion then
9989 Operand : constant Node_Id := Expression (N);
9990 Target_Typ : constant Entity_Id := Etype (N);
9991 Opnd_Typ : constant Entity_Id := Etype (Operand);
9994 if Is_Floating_Point_Type (Opnd_Typ)
9996 (Is_Integer_Type (Target_Typ)
9997 or else (Is_Fixed_Point_Type (Target_Typ)
9998 and then Conversion_OK (N)))
9999 and then Nkind (Operand) = N_Attribute_Reference
10000 and then Attribute_Name (Operand) = Name_Truncation
10002 -- Special processing required if the conversion is the expression
10003 -- of a Truncation attribute reference. In this case we replace:
10005 -- ityp (ftyp'Truncation (x))
10011 -- with the Float_Truncate flag set, which is more efficient.
10015 Relocate_Node (First (Expressions (Operand))));
10016 Set_Float_Truncate (N, True);
10020 end Simplify_Type_Conversion;
10022 -----------------------------
10023 -- Unique_Fixed_Point_Type --
10024 -----------------------------
10026 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
10027 T1 : Entity_Id := Empty;
10032 procedure Fixed_Point_Error;
10033 -- Give error messages for true ambiguity. Messages are posted on node
10034 -- N, and entities T1, T2 are the possible interpretations.
10036 -----------------------
10037 -- Fixed_Point_Error --
10038 -----------------------
10040 procedure Fixed_Point_Error is
10042 Error_Msg_N ("ambiguous universal_fixed_expression", N);
10043 Error_Msg_NE ("\\possible interpretation as}", N, T1);
10044 Error_Msg_NE ("\\possible interpretation as}", N, T2);
10045 end Fixed_Point_Error;
10047 -- Start of processing for Unique_Fixed_Point_Type
10050 -- The operations on Duration are visible, so Duration is always a
10051 -- possible interpretation.
10053 T1 := Standard_Duration;
10055 -- Look for fixed-point types in enclosing scopes
10057 Scop := Current_Scope;
10058 while Scop /= Standard_Standard loop
10059 T2 := First_Entity (Scop);
10060 while Present (T2) loop
10061 if Is_Fixed_Point_Type (T2)
10062 and then Current_Entity (T2) = T2
10063 and then Scope (Base_Type (T2)) = Scop
10065 if Present (T1) then
10076 Scop := Scope (Scop);
10079 -- Look for visible fixed type declarations in the context
10081 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
10082 while Present (Item) loop
10083 if Nkind (Item) = N_With_Clause then
10084 Scop := Entity (Name (Item));
10085 T2 := First_Entity (Scop);
10086 while Present (T2) loop
10087 if Is_Fixed_Point_Type (T2)
10088 and then Scope (Base_Type (T2)) = Scop
10089 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
10091 if Present (T1) then
10106 if Nkind (N) = N_Real_Literal then
10107 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
10109 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
10113 end Unique_Fixed_Point_Type;
10115 ----------------------
10116 -- Valid_Conversion --
10117 ----------------------
10119 function Valid_Conversion
10121 Target : Entity_Id;
10123 Report_Errs : Boolean := True) return Boolean
10125 Target_Type : constant Entity_Id := Base_Type (Target);
10126 Opnd_Type : Entity_Id := Etype (Operand);
10128 function Conversion_Check
10130 Msg : String) return Boolean;
10131 -- Little routine to post Msg if Valid is False, returns Valid value
10133 -- The following are badly named, this kind of overloading is actively
10134 -- confusing in reading code, please rename to something like
10135 -- Error_Msg_N_If_Reporting ???
10137 procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id);
10138 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
10140 procedure Error_Msg_NE
10142 N : Node_Or_Entity_Id;
10143 E : Node_Or_Entity_Id);
10144 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
10146 function Valid_Tagged_Conversion
10147 (Target_Type : Entity_Id;
10148 Opnd_Type : Entity_Id) return Boolean;
10149 -- Specifically test for validity of tagged conversions
10151 function Valid_Array_Conversion return Boolean;
10152 -- Check index and component conformance, and accessibility levels if
10153 -- the component types are anonymous access types (Ada 2005).
10155 ----------------------
10156 -- Conversion_Check --
10157 ----------------------
10159 function Conversion_Check
10161 Msg : String) return Boolean
10166 -- A generic unit has already been analyzed and we have verified
10167 -- that a particular conversion is OK in that context. Since the
10168 -- instance is reanalyzed without relying on the relationships
10169 -- established during the analysis of the generic, it is possible
10170 -- to end up with inconsistent views of private types. Do not emit
10171 -- the error message in such cases. The rest of the machinery in
10172 -- Valid_Conversion still ensures the proper compatibility of
10173 -- target and operand types.
10175 and then not In_Instance
10177 Error_Msg_N (Msg, Operand);
10181 end Conversion_Check;
10187 procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id) is
10189 if Report_Errs then
10190 Errout.Error_Msg_N (Msg, N);
10198 procedure Error_Msg_NE
10200 N : Node_Or_Entity_Id;
10201 E : Node_Or_Entity_Id)
10204 if Report_Errs then
10205 Errout.Error_Msg_NE (Msg, N, E);
10209 ----------------------------
10210 -- Valid_Array_Conversion --
10211 ----------------------------
10213 function Valid_Array_Conversion return Boolean
10215 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
10216 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
10218 Opnd_Index : Node_Id;
10219 Opnd_Index_Type : Entity_Id;
10221 Target_Comp_Type : constant Entity_Id :=
10222 Component_Type (Target_Type);
10223 Target_Comp_Base : constant Entity_Id :=
10224 Base_Type (Target_Comp_Type);
10226 Target_Index : Node_Id;
10227 Target_Index_Type : Entity_Id;
10230 -- Error if wrong number of dimensions
10233 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
10236 ("incompatible number of dimensions for conversion", Operand);
10239 -- Number of dimensions matches
10242 -- Loop through indexes of the two arrays
10244 Target_Index := First_Index (Target_Type);
10245 Opnd_Index := First_Index (Opnd_Type);
10246 while Present (Target_Index) and then Present (Opnd_Index) loop
10247 Target_Index_Type := Etype (Target_Index);
10248 Opnd_Index_Type := Etype (Opnd_Index);
10250 -- Error if index types are incompatible
10252 if not (Is_Integer_Type (Target_Index_Type)
10253 and then Is_Integer_Type (Opnd_Index_Type))
10254 and then (Root_Type (Target_Index_Type)
10255 /= Root_Type (Opnd_Index_Type))
10258 ("incompatible index types for array conversion",
10263 Next_Index (Target_Index);
10264 Next_Index (Opnd_Index);
10267 -- If component types have same base type, all set
10269 if Target_Comp_Base = Opnd_Comp_Base then
10272 -- Here if base types of components are not the same. The only
10273 -- time this is allowed is if we have anonymous access types.
10275 -- The conversion of arrays of anonymous access types can lead
10276 -- to dangling pointers. AI-392 formalizes the accessibility
10277 -- checks that must be applied to such conversions to prevent
10278 -- out-of-scope references.
10281 (Target_Comp_Base, E_Anonymous_Access_Type,
10282 E_Anonymous_Access_Subprogram_Type)
10283 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
10285 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
10287 if Type_Access_Level (Target_Type) <
10288 Type_Access_Level (Opnd_Type)
10290 if In_Instance_Body then
10291 Error_Msg_N ("?source array type " &
10292 "has deeper accessibility level than target", Operand);
10293 Error_Msg_N ("\?Program_Error will be raised at run time",
10296 Make_Raise_Program_Error (Sloc (N),
10297 Reason => PE_Accessibility_Check_Failed));
10298 Set_Etype (N, Target_Type);
10301 -- Conversion not allowed because of accessibility levels
10304 Error_Msg_N ("source array type " &
10305 "has deeper accessibility level than target", Operand);
10313 -- All other cases where component base types do not match
10317 ("incompatible component types for array conversion",
10322 -- Check that component subtypes statically match. For numeric
10323 -- types this means that both must be either constrained or
10324 -- unconstrained. For enumeration types the bounds must match.
10325 -- All of this is checked in Subtypes_Statically_Match.
10327 if not Subtypes_Statically_Match
10328 (Target_Comp_Type, Opnd_Comp_Type)
10331 ("component subtypes must statically match", Operand);
10337 end Valid_Array_Conversion;
10339 -----------------------------
10340 -- Valid_Tagged_Conversion --
10341 -----------------------------
10343 function Valid_Tagged_Conversion
10344 (Target_Type : Entity_Id;
10345 Opnd_Type : Entity_Id) return Boolean
10348 -- Upward conversions are allowed (RM 4.6(22))
10350 if Covers (Target_Type, Opnd_Type)
10351 or else Is_Ancestor (Target_Type, Opnd_Type)
10355 -- Downward conversion are allowed if the operand is class-wide
10358 elsif Is_Class_Wide_Type (Opnd_Type)
10359 and then Covers (Opnd_Type, Target_Type)
10363 elsif Covers (Opnd_Type, Target_Type)
10364 or else Is_Ancestor (Opnd_Type, Target_Type)
10367 Conversion_Check (False,
10368 "downward conversion of tagged objects not allowed");
10370 -- Ada 2005 (AI-251): The conversion to/from interface types is
10373 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
10376 -- If the operand is a class-wide type obtained through a limited_
10377 -- with clause, and the context includes the non-limited view, use
10378 -- it to determine whether the conversion is legal.
10380 elsif Is_Class_Wide_Type (Opnd_Type)
10381 and then From_With_Type (Opnd_Type)
10382 and then Present (Non_Limited_View (Etype (Opnd_Type)))
10383 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
10387 elsif Is_Access_Type (Opnd_Type)
10388 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
10394 ("invalid tagged conversion, not compatible with}",
10395 N, First_Subtype (Opnd_Type));
10398 end Valid_Tagged_Conversion;
10400 -- Start of processing for Valid_Conversion
10403 Check_Parameterless_Call (Operand);
10405 if Is_Overloaded (Operand) then
10415 -- Remove procedure calls, which syntactically cannot appear in
10416 -- this context, but which cannot be removed by type checking,
10417 -- because the context does not impose a type.
10419 -- When compiling for VMS, spurious ambiguities can be produced
10420 -- when arithmetic operations have a literal operand and return
10421 -- System.Address or a descendant of it. These ambiguities are
10422 -- otherwise resolved by the context, but for conversions there
10423 -- is no context type and the removal of the spurious operations
10424 -- must be done explicitly here.
10426 -- The node may be labelled overloaded, but still contain only one
10427 -- interpretation because others were discarded earlier. If this
10428 -- is the case, retain the single interpretation if legal.
10430 Get_First_Interp (Operand, I, It);
10431 Opnd_Type := It.Typ;
10432 Get_Next_Interp (I, It);
10434 if Present (It.Typ)
10435 and then Opnd_Type /= Standard_Void_Type
10437 -- More than one candidate interpretation is available
10439 Get_First_Interp (Operand, I, It);
10440 while Present (It.Typ) loop
10441 if It.Typ = Standard_Void_Type then
10445 if Present (System_Aux_Id)
10446 and then Is_Descendent_Of_Address (It.Typ)
10451 Get_Next_Interp (I, It);
10455 Get_First_Interp (Operand, I, It);
10459 if No (It.Typ) then
10460 Error_Msg_N ("illegal operand in conversion", Operand);
10464 Get_Next_Interp (I, It);
10466 if Present (It.Typ) then
10469 It1 := Disambiguate (Operand, I1, I, Any_Type);
10471 if It1 = No_Interp then
10472 Error_Msg_N ("ambiguous operand in conversion", Operand);
10474 -- If the interpretation involves a standard operator, use
10475 -- the location of the type, which may be user-defined.
10477 if Sloc (It.Nam) = Standard_Location then
10478 Error_Msg_Sloc := Sloc (It.Typ);
10480 Error_Msg_Sloc := Sloc (It.Nam);
10483 Error_Msg_N -- CODEFIX
10484 ("\\possible interpretation#!", Operand);
10486 if Sloc (N1) = Standard_Location then
10487 Error_Msg_Sloc := Sloc (T1);
10489 Error_Msg_Sloc := Sloc (N1);
10492 Error_Msg_N -- CODEFIX
10493 ("\\possible interpretation#!", Operand);
10499 Set_Etype (Operand, It1.Typ);
10500 Opnd_Type := It1.Typ;
10506 if Is_Numeric_Type (Target_Type) then
10508 -- A universal fixed expression can be converted to any numeric type
10510 if Opnd_Type = Universal_Fixed then
10513 -- Also no need to check when in an instance or inlined body, because
10514 -- the legality has been established when the template was analyzed.
10515 -- Furthermore, numeric conversions may occur where only a private
10516 -- view of the operand type is visible at the instantiation point.
10517 -- This results in a spurious error if we check that the operand type
10518 -- is a numeric type.
10520 -- Note: in a previous version of this unit, the following tests were
10521 -- applied only for generated code (Comes_From_Source set to False),
10522 -- but in fact the test is required for source code as well, since
10523 -- this situation can arise in source code.
10525 elsif In_Instance or else In_Inlined_Body then
10528 -- Otherwise we need the conversion check
10531 return Conversion_Check
10532 (Is_Numeric_Type (Opnd_Type),
10533 "illegal operand for numeric conversion");
10538 elsif Is_Array_Type (Target_Type) then
10539 if not Is_Array_Type (Opnd_Type)
10540 or else Opnd_Type = Any_Composite
10541 or else Opnd_Type = Any_String
10543 Error_Msg_N ("illegal operand for array conversion", Operand);
10546 return Valid_Array_Conversion;
10549 -- Ada 2005 (AI-251): Anonymous access types where target references an
10552 elsif Ekind_In (Target_Type, E_General_Access_Type,
10553 E_Anonymous_Access_Type)
10554 and then Is_Interface (Directly_Designated_Type (Target_Type))
10556 -- Check the static accessibility rule of 4.6(17). Note that the
10557 -- check is not enforced when within an instance body, since the
10558 -- RM requires such cases to be caught at run time.
10560 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
10561 if Type_Access_Level (Opnd_Type) >
10562 Deepest_Type_Access_Level (Target_Type)
10564 -- In an instance, this is a run-time check, but one we know
10565 -- will fail, so generate an appropriate warning. The raise
10566 -- will be generated by Expand_N_Type_Conversion.
10568 if In_Instance_Body then
10570 ("?cannot convert local pointer to non-local access type",
10573 ("\?Program_Error will be raised at run time", Operand);
10577 ("cannot convert local pointer to non-local access type",
10582 -- Special accessibility checks are needed in the case of access
10583 -- discriminants declared for a limited type.
10585 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10586 and then not Is_Local_Anonymous_Access (Opnd_Type)
10588 -- When the operand is a selected access discriminant the check
10589 -- needs to be made against the level of the object denoted by
10590 -- the prefix of the selected name (Object_Access_Level handles
10591 -- checking the prefix of the operand for this case).
10593 if Nkind (Operand) = N_Selected_Component
10594 and then Object_Access_Level (Operand) >
10595 Deepest_Type_Access_Level (Target_Type)
10597 -- In an instance, this is a run-time check, but one we know
10598 -- will fail, so generate an appropriate warning. The raise
10599 -- will be generated by Expand_N_Type_Conversion.
10601 if In_Instance_Body then
10603 ("?cannot convert access discriminant to non-local" &
10604 " access type", Operand);
10606 ("\?Program_Error will be raised at run time", Operand);
10609 ("cannot convert access discriminant to non-local" &
10610 " access type", Operand);
10615 -- The case of a reference to an access discriminant from
10616 -- within a limited type declaration (which will appear as
10617 -- a discriminal) is always illegal because the level of the
10618 -- discriminant is considered to be deeper than any (nameable)
10621 if Is_Entity_Name (Operand)
10622 and then not Is_Local_Anonymous_Access (Opnd_Type)
10624 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10625 and then Present (Discriminal_Link (Entity (Operand)))
10628 ("discriminant has deeper accessibility level than target",
10637 -- General and anonymous access types
10639 elsif Ekind_In (Target_Type, E_General_Access_Type,
10640 E_Anonymous_Access_Type)
10643 (Is_Access_Type (Opnd_Type)
10645 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
10646 E_Access_Protected_Subprogram_Type),
10647 "must be an access-to-object type")
10649 if Is_Access_Constant (Opnd_Type)
10650 and then not Is_Access_Constant (Target_Type)
10653 ("access-to-constant operand type not allowed", Operand);
10657 -- Check the static accessibility rule of 4.6(17). Note that the
10658 -- check is not enforced when within an instance body, since the RM
10659 -- requires such cases to be caught at run time.
10661 if Ekind (Target_Type) /= E_Anonymous_Access_Type
10662 or else Is_Local_Anonymous_Access (Target_Type)
10663 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
10664 N_Object_Declaration
10666 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
10667 -- conversions from an anonymous access type to a named general
10668 -- access type. Such conversions are not allowed in the case of
10669 -- access parameters and stand-alone objects of an anonymous
10670 -- access type. The implicit conversion case is recognized by
10671 -- testing that Comes_From_Source is False and that it's been
10672 -- rewritten. The Comes_From_Source test isn't sufficient because
10673 -- nodes in inlined calls to predefined library routines can have
10674 -- Comes_From_Source set to False. (Is there a better way to test
10675 -- for implicit conversions???)
10677 if Ada_Version >= Ada_2012
10678 and then not Comes_From_Source (N)
10679 and then N /= Original_Node (N)
10680 and then Ekind (Target_Type) = E_General_Access_Type
10681 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
10683 if Is_Itype (Opnd_Type) then
10685 -- Implicit conversions aren't allowed for objects of an
10686 -- anonymous access type, since such objects have nonstatic
10687 -- levels in Ada 2012.
10689 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
10690 N_Object_Declaration
10693 ("implicit conversion of stand-alone anonymous " &
10694 "access object not allowed", Operand);
10697 -- Implicit conversions aren't allowed for anonymous access
10698 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
10699 -- is done to exclude anonymous access results.
10701 elsif not Is_Local_Anonymous_Access (Opnd_Type)
10702 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
10703 N_Function_Specification,
10704 N_Procedure_Specification)
10707 ("implicit conversion of anonymous access formal " &
10708 "not allowed", Operand);
10711 -- This is a case where there's an enclosing object whose
10712 -- to which the "statically deeper than" relationship does
10713 -- not apply (such as an access discriminant selected from
10714 -- a dereference of an access parameter).
10716 elsif Object_Access_Level (Operand)
10717 = Scope_Depth (Standard_Standard)
10720 ("implicit conversion of anonymous access value " &
10721 "not allowed", Operand);
10724 -- In other cases, the level of the operand's type must be
10725 -- statically less deep than that of the target type, else
10726 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
10728 elsif Type_Access_Level (Opnd_Type) >
10729 Deepest_Type_Access_Level (Target_Type)
10732 ("implicit conversion of anonymous access value " &
10733 "violates accessibility", Operand);
10738 elsif Type_Access_Level (Opnd_Type) >
10739 Deepest_Type_Access_Level (Target_Type)
10741 -- In an instance, this is a run-time check, but one we know
10742 -- will fail, so generate an appropriate warning. The raise
10743 -- will be generated by Expand_N_Type_Conversion.
10745 if In_Instance_Body then
10747 ("?cannot convert local pointer to non-local access type",
10750 ("\?Program_Error will be raised at run time", Operand);
10753 -- Avoid generation of spurious error message
10755 if not Error_Posted (N) then
10757 ("cannot convert local pointer to non-local access type",
10764 -- Special accessibility checks are needed in the case of access
10765 -- discriminants declared for a limited type.
10767 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10768 and then not Is_Local_Anonymous_Access (Opnd_Type)
10770 -- When the operand is a selected access discriminant the check
10771 -- needs to be made against the level of the object denoted by
10772 -- the prefix of the selected name (Object_Access_Level handles
10773 -- checking the prefix of the operand for this case).
10775 if Nkind (Operand) = N_Selected_Component
10776 and then Object_Access_Level (Operand) >
10777 Deepest_Type_Access_Level (Target_Type)
10779 -- In an instance, this is a run-time check, but one we know
10780 -- will fail, so generate an appropriate warning. The raise
10781 -- will be generated by Expand_N_Type_Conversion.
10783 if In_Instance_Body then
10785 ("?cannot convert access discriminant to non-local" &
10786 " access type", Operand);
10788 ("\?Program_Error will be raised at run time",
10793 ("cannot convert access discriminant to non-local" &
10794 " access type", Operand);
10799 -- The case of a reference to an access discriminant from
10800 -- within a limited type declaration (which will appear as
10801 -- a discriminal) is always illegal because the level of the
10802 -- discriminant is considered to be deeper than any (nameable)
10805 if Is_Entity_Name (Operand)
10807 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10808 and then Present (Discriminal_Link (Entity (Operand)))
10811 ("discriminant has deeper accessibility level than target",
10818 -- In the presence of limited_with clauses we have to use non-limited
10819 -- views, if available.
10821 Check_Limited : declare
10822 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
10823 -- Helper function to handle limited views
10825 --------------------------
10826 -- Full_Designated_Type --
10827 --------------------------
10829 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
10830 Desig : constant Entity_Id := Designated_Type (T);
10833 -- Handle the limited view of a type
10835 if Is_Incomplete_Type (Desig)
10836 and then From_With_Type (Desig)
10837 and then Present (Non_Limited_View (Desig))
10839 return Available_View (Desig);
10843 end Full_Designated_Type;
10845 -- Local Declarations
10847 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
10848 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
10850 Same_Base : constant Boolean :=
10851 Base_Type (Target) = Base_Type (Opnd);
10853 -- Start of processing for Check_Limited
10856 if Is_Tagged_Type (Target) then
10857 return Valid_Tagged_Conversion (Target, Opnd);
10860 if not Same_Base then
10862 ("target designated type not compatible with }",
10863 N, Base_Type (Opnd));
10866 -- Ada 2005 AI-384: legality rule is symmetric in both
10867 -- designated types. The conversion is legal (with possible
10868 -- constraint check) if either designated type is
10871 elsif Subtypes_Statically_Match (Target, Opnd)
10873 (Has_Discriminants (Target)
10875 (not Is_Constrained (Opnd)
10876 or else not Is_Constrained (Target)))
10878 -- Special case, if Value_Size has been used to make the
10879 -- sizes different, the conversion is not allowed even
10880 -- though the subtypes statically match.
10882 if Known_Static_RM_Size (Target)
10883 and then Known_Static_RM_Size (Opnd)
10884 and then RM_Size (Target) /= RM_Size (Opnd)
10887 ("target designated subtype not compatible with }",
10890 ("\because sizes of the two designated subtypes differ",
10894 -- Normal case where conversion is allowed
10902 ("target designated subtype not compatible with }",
10909 -- Access to subprogram types. If the operand is an access parameter,
10910 -- the type has a deeper accessibility that any master, and cannot be
10911 -- assigned. We must make an exception if the conversion is part of an
10912 -- assignment and the target is the return object of an extended return
10913 -- statement, because in that case the accessibility check takes place
10914 -- after the return.
10916 elsif Is_Access_Subprogram_Type (Target_Type)
10917 and then No (Corresponding_Remote_Type (Opnd_Type))
10919 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
10920 and then Is_Entity_Name (Operand)
10921 and then Ekind (Entity (Operand)) = E_In_Parameter
10923 (Nkind (Parent (N)) /= N_Assignment_Statement
10924 or else not Is_Entity_Name (Name (Parent (N)))
10925 or else not Is_Return_Object (Entity (Name (Parent (N)))))
10928 ("illegal attempt to store anonymous access to subprogram",
10931 ("\value has deeper accessibility than any master " &
10932 "(RM 3.10.2 (13))",
10936 ("\use named access type for& instead of access parameter",
10937 Operand, Entity (Operand));
10940 -- Check that the designated types are subtype conformant
10942 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
10943 Old_Id => Designated_Type (Opnd_Type),
10946 -- Check the static accessibility rule of 4.6(20)
10948 if Type_Access_Level (Opnd_Type) >
10949 Deepest_Type_Access_Level (Target_Type)
10952 ("operand type has deeper accessibility level than target",
10955 -- Check that if the operand type is declared in a generic body,
10956 -- then the target type must be declared within that same body
10957 -- (enforces last sentence of 4.6(20)).
10959 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
10961 O_Gen : constant Node_Id :=
10962 Enclosing_Generic_Body (Opnd_Type);
10967 T_Gen := Enclosing_Generic_Body (Target_Type);
10968 while Present (T_Gen) and then T_Gen /= O_Gen loop
10969 T_Gen := Enclosing_Generic_Body (T_Gen);
10972 if T_Gen /= O_Gen then
10974 ("target type must be declared in same generic body"
10975 & " as operand type", N);
10982 -- Remote subprogram access types
10984 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
10985 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
10987 -- It is valid to convert from one RAS type to another provided
10988 -- that their specification statically match.
10990 Check_Subtype_Conformant
10992 Designated_Type (Corresponding_Remote_Type (Target_Type)),
10994 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
10999 -- If both are tagged types, check legality of view conversions
11001 elsif Is_Tagged_Type (Target_Type)
11003 Is_Tagged_Type (Opnd_Type)
11005 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
11007 -- Types derived from the same root type are convertible
11009 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
11012 -- In an instance or an inlined body, there may be inconsistent views of
11013 -- the same type, or of types derived from a common root.
11015 elsif (In_Instance or In_Inlined_Body)
11017 Root_Type (Underlying_Type (Target_Type)) =
11018 Root_Type (Underlying_Type (Opnd_Type))
11022 -- Special check for common access type error case
11024 elsif Ekind (Target_Type) = E_Access_Type
11025 and then Is_Access_Type (Opnd_Type)
11027 Error_Msg_N ("target type must be general access type!", N);
11028 Error_Msg_NE -- CODEFIX
11029 ("add ALL to }!", N, Target_Type);
11033 Error_Msg_NE ("invalid conversion, not compatible with }",
11037 end Valid_Conversion;
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