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 function Valid_Conversion
279 Operand : Node_Id) return Boolean;
280 -- Verify legality rules given in 4.6 (8-23). Target is the target type
281 -- of the conversion, which may be an implicit conversion of an actual
282 -- parameter to an anonymous access type (in which case N denotes the
283 -- actual parameter and N = Operand).
285 -------------------------
286 -- Ambiguous_Character --
287 -------------------------
289 procedure Ambiguous_Character (C : Node_Id) is
293 if Nkind (C) = N_Character_Literal then
294 Error_Msg_N ("ambiguous character literal", C);
296 -- First the ones in Standard
298 Error_Msg_N ("\\possible interpretation: Character!", C);
299 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
301 -- Include Wide_Wide_Character in Ada 2005 mode
303 if Ada_Version >= Ada_2005 then
304 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
307 -- Now any other types that match
309 E := Current_Entity (C);
310 while Present (E) loop
311 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
315 end Ambiguous_Character;
317 -------------------------
318 -- Analyze_And_Resolve --
319 -------------------------
321 procedure Analyze_And_Resolve (N : Node_Id) is
325 end Analyze_And_Resolve;
327 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
331 end Analyze_And_Resolve;
333 -- Version withs check(s) suppressed
335 procedure Analyze_And_Resolve
340 Scop : constant Entity_Id := Current_Scope;
343 if Suppress = All_Checks then
345 Svg : constant Suppress_Array := Scope_Suppress;
347 Scope_Suppress := (others => True);
348 Analyze_And_Resolve (N, Typ);
349 Scope_Suppress := Svg;
354 Svg : constant Boolean := Scope_Suppress (Suppress);
357 Scope_Suppress (Suppress) := True;
358 Analyze_And_Resolve (N, Typ);
359 Scope_Suppress (Suppress) := Svg;
363 if Current_Scope /= Scop
364 and then Scope_Is_Transient
366 -- This can only happen if a transient scope was created for an inner
367 -- expression, which will be removed upon completion of the analysis
368 -- of an enclosing construct. The transient scope must have the
369 -- suppress status of the enclosing environment, not of this Analyze
372 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
375 end Analyze_And_Resolve;
377 procedure Analyze_And_Resolve
381 Scop : constant Entity_Id := Current_Scope;
384 if Suppress = All_Checks then
386 Svg : constant Suppress_Array := Scope_Suppress;
388 Scope_Suppress := (others => True);
389 Analyze_And_Resolve (N);
390 Scope_Suppress := Svg;
395 Svg : constant Boolean := Scope_Suppress (Suppress);
398 Scope_Suppress (Suppress) := True;
399 Analyze_And_Resolve (N);
400 Scope_Suppress (Suppress) := Svg;
404 if Current_Scope /= Scop
405 and then Scope_Is_Transient
407 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
410 end Analyze_And_Resolve;
412 ----------------------------------------
413 -- Bad_Unordered_Enumeration_Reference --
414 ----------------------------------------
416 function Bad_Unordered_Enumeration_Reference
418 T : Entity_Id) return Boolean
421 return Is_Enumeration_Type (T)
422 and then Comes_From_Source (N)
423 and then Warn_On_Unordered_Enumeration_Type
424 and then not Has_Pragma_Ordered (T)
425 and then not In_Same_Extended_Unit (N, T);
426 end Bad_Unordered_Enumeration_Reference;
428 ----------------------------
429 -- Check_Discriminant_Use --
430 ----------------------------
432 procedure Check_Discriminant_Use (N : Node_Id) is
433 PN : constant Node_Id := Parent (N);
434 Disc : constant Entity_Id := Entity (N);
439 -- Any use in a spec-expression is legal
441 if In_Spec_Expression then
444 elsif Nkind (PN) = N_Range then
446 -- Discriminant cannot be used to constrain a scalar type
450 if Nkind (P) = N_Range_Constraint
451 and then Nkind (Parent (P)) = N_Subtype_Indication
452 and then Nkind (Parent (Parent (P))) = N_Component_Definition
454 Error_Msg_N ("discriminant cannot constrain scalar type", N);
456 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
458 -- The following check catches the unusual case where a
459 -- discriminant appears within an index constraint that is part of
460 -- a larger expression within a constraint on a component, e.g. "C
461 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
462 -- of record components, and note that a similar check should also
463 -- apply in the case of discriminant constraints below. ???
465 -- Note that the check for N_Subtype_Declaration below is to
466 -- detect the valid use of discriminants in the constraints of a
467 -- subtype declaration when this subtype declaration appears
468 -- inside the scope of a record type (which is syntactically
469 -- illegal, but which may be created as part of derived type
470 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
473 if Ekind (Current_Scope) = E_Record_Type
474 and then Scope (Disc) = Current_Scope
476 (Nkind (Parent (P)) = N_Subtype_Indication
478 Nkind_In (Parent (Parent (P)), N_Component_Definition,
479 N_Subtype_Declaration)
480 and then Paren_Count (N) = 0)
483 ("discriminant must appear alone in component constraint", N);
487 -- Detect a common error:
489 -- type R (D : Positive := 100) is record
490 -- Name : String (1 .. D);
493 -- The default value causes an object of type R to be allocated
494 -- with room for Positive'Last characters. The RM does not mandate
495 -- the allocation of the maximum size, but that is what GNAT does
496 -- so we should warn the programmer that there is a problem.
498 Check_Large : declare
504 function Large_Storage_Type (T : Entity_Id) return Boolean;
505 -- Return True if type T has a large enough range that any
506 -- array whose index type covered the whole range of the type
507 -- would likely raise Storage_Error.
509 ------------------------
510 -- Large_Storage_Type --
511 ------------------------
513 function Large_Storage_Type (T : Entity_Id) return Boolean is
515 -- The type is considered large if its bounds are known at
516 -- compile time and if it requires at least as many bits as
517 -- a Positive to store the possible values.
519 return Compile_Time_Known_Value (Type_Low_Bound (T))
520 and then Compile_Time_Known_Value (Type_High_Bound (T))
522 Minimum_Size (T, Biased => True) >=
523 RM_Size (Standard_Positive);
524 end Large_Storage_Type;
526 -- Start of processing for Check_Large
529 -- Check that the Disc has a large range
531 if not Large_Storage_Type (Etype (Disc)) then
535 -- If the enclosing type is limited, we allocate only the
536 -- default value, not the maximum, and there is no need for
539 if Is_Limited_Type (Scope (Disc)) then
543 -- Check that it is the high bound
545 if N /= High_Bound (PN)
546 or else No (Discriminant_Default_Value (Disc))
551 -- Check the array allows a large range at this bound. First
556 if Nkind (SI) /= N_Subtype_Indication then
560 T := Entity (Subtype_Mark (SI));
562 if not Is_Array_Type (T) then
566 -- Next, find the dimension
568 TB := First_Index (T);
569 CB := First (Constraints (P));
571 and then Present (TB)
572 and then Present (CB)
583 -- Now, check the dimension has a large range
585 if not Large_Storage_Type (Etype (TB)) then
589 -- Warn about the danger
592 ("?creation of & object may raise Storage_Error!",
601 -- Legal case is in index or discriminant constraint
603 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
604 N_Discriminant_Association)
606 if Paren_Count (N) > 0 then
608 ("discriminant in constraint must appear alone", N);
610 elsif Nkind (N) = N_Expanded_Name
611 and then Comes_From_Source (N)
614 ("discriminant must appear alone as a direct name", N);
619 -- Otherwise, context is an expression. It should not be within (i.e. a
620 -- subexpression of) a constraint for a component.
625 while not Nkind_In (P, N_Component_Declaration,
626 N_Subtype_Indication,
634 -- If the discriminant is used in an expression that is a bound of a
635 -- scalar type, an Itype is created and the bounds are attached to
636 -- its range, not to the original subtype indication. Such use is of
637 -- course a double fault.
639 if (Nkind (P) = N_Subtype_Indication
640 and then Nkind_In (Parent (P), N_Component_Definition,
641 N_Derived_Type_Definition)
642 and then D = Constraint (P))
644 -- The constraint itself may be given by a subtype indication,
645 -- rather than by a more common discrete range.
647 or else (Nkind (P) = N_Subtype_Indication
649 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
650 or else Nkind (P) = N_Entry_Declaration
651 or else Nkind (D) = N_Defining_Identifier
654 ("discriminant in constraint must appear alone", N);
657 end Check_Discriminant_Use;
659 --------------------------------
660 -- Check_For_Visible_Operator --
661 --------------------------------
663 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
665 if Is_Invisible_Operator (N, T) then
666 Error_Msg_NE -- CODEFIX
667 ("operator for} is not directly visible!", N, First_Subtype (T));
668 Error_Msg_N -- CODEFIX
669 ("use clause would make operation legal!", N);
671 end Check_For_Visible_Operator;
673 ----------------------------------
674 -- Check_Fully_Declared_Prefix --
675 ----------------------------------
677 procedure Check_Fully_Declared_Prefix
682 -- Check that the designated type of the prefix of a dereference is
683 -- not an incomplete type. This cannot be done unconditionally, because
684 -- dereferences of private types are legal in default expressions. This
685 -- case is taken care of in Check_Fully_Declared, called below. There
686 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
688 -- This consideration also applies to similar checks for allocators,
689 -- qualified expressions, and type conversions.
691 -- An additional exception concerns other per-object expressions that
692 -- are not directly related to component declarations, in particular
693 -- representation pragmas for tasks. These will be per-object
694 -- expressions if they depend on discriminants or some global entity.
695 -- If the task has access discriminants, the designated type may be
696 -- incomplete at the point the expression is resolved. This resolution
697 -- takes place within the body of the initialization procedure, where
698 -- the discriminant is replaced by its discriminal.
700 if Is_Entity_Name (Pref)
701 and then Ekind (Entity (Pref)) = E_In_Parameter
705 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
706 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
707 -- Analyze_Object_Renaming, and Freeze_Entity.
709 elsif Ada_Version >= Ada_2005
710 and then Is_Entity_Name (Pref)
711 and then Is_Access_Type (Etype (Pref))
712 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
714 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
718 Check_Fully_Declared (Typ, Parent (Pref));
720 end Check_Fully_Declared_Prefix;
722 ------------------------------
723 -- Check_Infinite_Recursion --
724 ------------------------------
726 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
730 function Same_Argument_List return Boolean;
731 -- Check whether list of actuals is identical to list of formals of
732 -- called function (which is also the enclosing scope).
734 ------------------------
735 -- Same_Argument_List --
736 ------------------------
738 function Same_Argument_List return Boolean is
744 if not Is_Entity_Name (Name (N)) then
747 Subp := Entity (Name (N));
750 F := First_Formal (Subp);
751 A := First_Actual (N);
752 while Present (F) and then Present (A) loop
753 if not Is_Entity_Name (A)
754 or else Entity (A) /= F
764 end Same_Argument_List;
766 -- Start of processing for Check_Infinite_Recursion
769 -- Special case, if this is a procedure call and is a call to the
770 -- current procedure with the same argument list, then this is for
771 -- sure an infinite recursion and we insert a call to raise SE.
773 if Is_List_Member (N)
774 and then List_Length (List_Containing (N)) = 1
775 and then Same_Argument_List
778 P : constant Node_Id := Parent (N);
780 if Nkind (P) = N_Handled_Sequence_Of_Statements
781 and then Nkind (Parent (P)) = N_Subprogram_Body
782 and then Is_Empty_List (Declarations (Parent (P)))
784 Error_Msg_N ("!?infinite recursion", N);
785 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
787 Make_Raise_Storage_Error (Sloc (N),
788 Reason => SE_Infinite_Recursion));
794 -- If not that special case, search up tree, quitting if we reach a
795 -- construct (e.g. a conditional) that tells us that this is not a
796 -- case for an infinite recursion warning.
802 -- If no parent, then we were not inside a subprogram, this can for
803 -- example happen when processing certain pragmas in a spec. Just
804 -- return False in this case.
810 -- Done if we get to subprogram body, this is definitely an infinite
811 -- recursion case if we did not find anything to stop us.
813 exit when Nkind (P) = N_Subprogram_Body;
815 -- If appearing in conditional, result is false
817 if Nkind_In (P, N_Or_Else,
821 N_Conditional_Expression,
826 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
827 and then C /= First (Statements (P))
829 -- If the call is the expression of a return statement and the
830 -- actuals are identical to the formals, it's worth a warning.
831 -- However, we skip this if there is an immediately preceding
832 -- raise statement, since the call is never executed.
834 -- Furthermore, this corresponds to a common idiom:
836 -- function F (L : Thing) return Boolean is
838 -- raise Program_Error;
842 -- for generating a stub function
844 if Nkind (Parent (N)) = N_Simple_Return_Statement
845 and then Same_Argument_List
847 exit when not Is_List_Member (Parent (N));
849 -- OK, return statement is in a statement list, look for raise
855 -- Skip past N_Freeze_Entity nodes generated by expansion
857 Nod := Prev (Parent (N));
859 and then Nkind (Nod) = N_Freeze_Entity
864 -- If no raise statement, give warning
866 exit when Nkind (Nod) /= N_Raise_Statement
868 (Nkind (Nod) not in N_Raise_xxx_Error
869 or else Present (Condition (Nod)));
880 Error_Msg_N ("!?possible infinite recursion", N);
881 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
884 end Check_Infinite_Recursion;
886 -------------------------------
887 -- Check_Initialization_Call --
888 -------------------------------
890 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
891 Typ : constant Entity_Id := Etype (First_Formal (Nam));
893 function Uses_SS (T : Entity_Id) return Boolean;
894 -- Check whether the creation of an object of the type will involve
895 -- use of the secondary stack. If T is a record type, this is true
896 -- if the expression for some component uses the secondary stack, e.g.
897 -- through a call to a function that returns an unconstrained value.
898 -- False if T is controlled, because cleanups occur elsewhere.
904 function Uses_SS (T : Entity_Id) return Boolean is
907 Full_Type : Entity_Id := Underlying_Type (T);
910 -- Normally we want to use the underlying type, but if it's not set
911 -- then continue with T.
913 if not Present (Full_Type) then
917 if Is_Controlled (Full_Type) then
920 elsif Is_Array_Type (Full_Type) then
921 return Uses_SS (Component_Type (Full_Type));
923 elsif Is_Record_Type (Full_Type) then
924 Comp := First_Component (Full_Type);
925 while Present (Comp) loop
926 if Ekind (Comp) = E_Component
927 and then Nkind (Parent (Comp)) = N_Component_Declaration
929 -- The expression for a dynamic component may be rewritten
930 -- as a dereference, so retrieve original node.
932 Expr := Original_Node (Expression (Parent (Comp)));
934 -- Return True if the expression is a call to a function
935 -- (including an attribute function such as Image, or a
936 -- user-defined operator) with a result that requires a
939 if (Nkind (Expr) = N_Function_Call
940 or else Nkind (Expr) in N_Op
941 or else (Nkind (Expr) = N_Attribute_Reference
942 and then Present (Expressions (Expr))))
943 and then Requires_Transient_Scope (Etype (Expr))
947 elsif Uses_SS (Etype (Comp)) then
952 Next_Component (Comp);
962 -- Start of processing for Check_Initialization_Call
965 -- Establish a transient scope if the type needs it
967 if Uses_SS (Typ) then
968 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
970 end Check_Initialization_Call;
972 ---------------------------------------
973 -- Check_No_Direct_Boolean_Operators --
974 ---------------------------------------
976 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
978 if Scope (Entity (N)) = Standard_Standard
979 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
981 -- Restriction only applies to original source code
983 if Comes_From_Source (N) then
984 Check_Restriction (No_Direct_Boolean_Operators, N);
989 Check_Boolean_Operator (N);
991 end Check_No_Direct_Boolean_Operators;
993 ------------------------------
994 -- Check_Parameterless_Call --
995 ------------------------------
997 procedure Check_Parameterless_Call (N : Node_Id) is
1000 function Prefix_Is_Access_Subp return Boolean;
1001 -- If the prefix is of an access_to_subprogram type, the node must be
1002 -- rewritten as a call. Ditto if the prefix is overloaded and all its
1003 -- interpretations are access to subprograms.
1005 ---------------------------
1006 -- Prefix_Is_Access_Subp --
1007 ---------------------------
1009 function Prefix_Is_Access_Subp return Boolean is
1014 -- If the context is an attribute reference that can apply to
1015 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1017 if Nkind (Parent (N)) = N_Attribute_Reference
1018 and then (Attribute_Name (Parent (N)) = Name_Address or else
1019 Attribute_Name (Parent (N)) = Name_Code_Address or else
1020 Attribute_Name (Parent (N)) = Name_Access)
1025 if not Is_Overloaded (N) then
1027 Ekind (Etype (N)) = E_Subprogram_Type
1028 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1030 Get_First_Interp (N, I, It);
1031 while Present (It.Typ) loop
1032 if Ekind (It.Typ) /= E_Subprogram_Type
1033 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1038 Get_Next_Interp (I, It);
1043 end Prefix_Is_Access_Subp;
1045 -- Start of processing for Check_Parameterless_Call
1048 -- Defend against junk stuff if errors already detected
1050 if Total_Errors_Detected /= 0 then
1051 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1053 elsif Nkind (N) in N_Has_Chars
1054 and then Chars (N) in Error_Name_Or_No_Name
1062 -- If the context expects a value, and the name is a procedure, this is
1063 -- most likely a missing 'Access. Don't try to resolve the parameterless
1064 -- call, error will be caught when the outer call is analyzed.
1066 if Is_Entity_Name (N)
1067 and then Ekind (Entity (N)) = E_Procedure
1068 and then not Is_Overloaded (N)
1070 Nkind_In (Parent (N), N_Parameter_Association,
1072 N_Procedure_Call_Statement)
1077 -- Rewrite as call if overloadable entity that is (or could be, in the
1078 -- overloaded case) a function call. If we know for sure that the entity
1079 -- is an enumeration literal, we do not rewrite it.
1081 -- If the entity is the name of an operator, it cannot be a call because
1082 -- operators cannot have default parameters. In this case, this must be
1083 -- a string whose contents coincide with an operator name. Set the kind
1084 -- of the node appropriately.
1086 if (Is_Entity_Name (N)
1087 and then Nkind (N) /= N_Operator_Symbol
1088 and then Is_Overloadable (Entity (N))
1089 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1090 or else Is_Overloaded (N)))
1092 -- Rewrite as call if it is an explicit dereference of an expression of
1093 -- a subprogram access type, and the subprogram type is not that of a
1094 -- procedure or entry.
1097 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1099 -- Rewrite as call if it is a selected component which is a function,
1100 -- this is the case of a call to a protected function (which may be
1101 -- overloaded with other protected operations).
1104 (Nkind (N) = N_Selected_Component
1105 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1107 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1109 and then Is_Overloaded (Selector_Name (N)))))
1111 -- If one of the above three conditions is met, rewrite as call. Apply
1112 -- the rewriting only once.
1115 if Nkind (Parent (N)) /= N_Function_Call
1116 or else N /= Name (Parent (N))
1118 Nam := New_Copy (N);
1120 -- If overloaded, overload set belongs to new copy
1122 Save_Interps (N, Nam);
1124 -- Change node to parameterless function call (note that the
1125 -- Parameter_Associations associations field is left set to Empty,
1126 -- its normal default value since there are no parameters)
1128 Change_Node (N, N_Function_Call);
1130 Set_Sloc (N, Sloc (Nam));
1134 elsif Nkind (N) = N_Parameter_Association then
1135 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1137 elsif Nkind (N) = N_Operator_Symbol then
1138 Change_Operator_Symbol_To_String_Literal (N);
1139 Set_Is_Overloaded (N, False);
1140 Set_Etype (N, Any_String);
1142 end Check_Parameterless_Call;
1144 -----------------------------
1145 -- Is_Definite_Access_Type --
1146 -----------------------------
1148 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1149 Btyp : constant Entity_Id := Base_Type (E);
1151 return Ekind (Btyp) = E_Access_Type
1152 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1153 and then Comes_From_Source (Btyp));
1154 end Is_Definite_Access_Type;
1156 ----------------------
1157 -- Is_Predefined_Op --
1158 ----------------------
1160 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1162 -- Predefined operators are intrinsic subprograms
1164 if not Is_Intrinsic_Subprogram (Nam) then
1168 -- A call to a back-end builtin is never a predefined operator
1170 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1174 return not Is_Generic_Instance (Nam)
1175 and then Chars (Nam) in Any_Operator_Name
1176 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1177 end Is_Predefined_Op;
1179 -----------------------------
1180 -- Make_Call_Into_Operator --
1181 -----------------------------
1183 procedure Make_Call_Into_Operator
1188 Op_Name : constant Name_Id := Chars (Op_Id);
1189 Act1 : Node_Id := First_Actual (N);
1190 Act2 : Node_Id := Next_Actual (Act1);
1191 Error : Boolean := False;
1192 Func : constant Entity_Id := Entity (Name (N));
1193 Is_Binary : constant Boolean := Present (Act2);
1195 Opnd_Type : Entity_Id;
1196 Orig_Type : Entity_Id := Empty;
1199 type Kind_Test is access function (E : Entity_Id) return Boolean;
1201 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1202 -- If the operand is not universal, and the operator is given by an
1203 -- expanded name, verify that the operand has an interpretation with a
1204 -- type defined in the given scope of the operator.
1206 function Type_In_P (Test : Kind_Test) return Entity_Id;
1207 -- Find a type of the given class in package Pack that contains the
1210 ---------------------------
1211 -- Operand_Type_In_Scope --
1212 ---------------------------
1214 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1215 Nod : constant Node_Id := Right_Opnd (Op_Node);
1220 if not Is_Overloaded (Nod) then
1221 return Scope (Base_Type (Etype (Nod))) = S;
1224 Get_First_Interp (Nod, I, It);
1225 while Present (It.Typ) loop
1226 if Scope (Base_Type (It.Typ)) = S then
1230 Get_Next_Interp (I, It);
1235 end Operand_Type_In_Scope;
1241 function Type_In_P (Test : Kind_Test) return Entity_Id is
1244 function In_Decl return Boolean;
1245 -- Verify that node is not part of the type declaration for the
1246 -- candidate type, which would otherwise be invisible.
1252 function In_Decl return Boolean is
1253 Decl_Node : constant Node_Id := Parent (E);
1259 if Etype (E) = Any_Type then
1262 elsif No (Decl_Node) then
1267 and then Nkind (N2) /= N_Compilation_Unit
1269 if N2 = Decl_Node then
1280 -- Start of processing for Type_In_P
1283 -- If the context type is declared in the prefix package, this is the
1284 -- desired base type.
1286 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1287 return Base_Type (Typ);
1290 E := First_Entity (Pack);
1291 while Present (E) loop
1293 and then not In_Decl
1305 -- Start of processing for Make_Call_Into_Operator
1308 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1313 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1314 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1315 Save_Interps (Act1, Left_Opnd (Op_Node));
1316 Save_Interps (Act2, Right_Opnd (Op_Node));
1317 Act1 := Left_Opnd (Op_Node);
1318 Act2 := Right_Opnd (Op_Node);
1323 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1324 Save_Interps (Act1, Right_Opnd (Op_Node));
1325 Act1 := Right_Opnd (Op_Node);
1328 -- If the operator is denoted by an expanded name, and the prefix is
1329 -- not Standard, but the operator is a predefined one whose scope is
1330 -- Standard, then this is an implicit_operator, inserted as an
1331 -- interpretation by the procedure of the same name. This procedure
1332 -- overestimates the presence of implicit operators, because it does
1333 -- not examine the type of the operands. Verify now that the operand
1334 -- type appears in the given scope. If right operand is universal,
1335 -- check the other operand. In the case of concatenation, either
1336 -- argument can be the component type, so check the type of the result.
1337 -- If both arguments are literals, look for a type of the right kind
1338 -- defined in the given scope. This elaborate nonsense is brought to
1339 -- you courtesy of b33302a. The type itself must be frozen, so we must
1340 -- find the type of the proper class in the given scope.
1342 -- A final wrinkle is the multiplication operator for fixed point types,
1343 -- which is defined in Standard only, and not in the scope of the
1344 -- fixed point type itself.
1346 if Nkind (Name (N)) = N_Expanded_Name then
1347 Pack := Entity (Prefix (Name (N)));
1349 -- If the entity being called is defined in the given package, it is
1350 -- a renaming of a predefined operator, and known to be legal.
1352 if Scope (Entity (Name (N))) = Pack
1353 and then Pack /= Standard_Standard
1357 -- Visibility does not need to be checked in an instance: if the
1358 -- operator was not visible in the generic it has been diagnosed
1359 -- already, else there is an implicit copy of it in the instance.
1361 elsif In_Instance then
1364 elsif (Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide)
1365 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1366 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1368 if Pack /= Standard_Standard then
1372 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1375 elsif Ada_Version >= Ada_2005
1376 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1377 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1382 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1384 if Op_Name = Name_Op_Concat then
1385 Opnd_Type := Base_Type (Typ);
1387 elsif (Scope (Opnd_Type) = Standard_Standard
1389 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1391 and then not Comes_From_Source (Opnd_Type))
1393 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1396 if Scope (Opnd_Type) = Standard_Standard then
1398 -- Verify that the scope contains a type that corresponds to
1399 -- the given literal. Optimize the case where Pack is Standard.
1401 if Pack /= Standard_Standard then
1403 if Opnd_Type = Universal_Integer then
1404 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1406 elsif Opnd_Type = Universal_Real then
1407 Orig_Type := Type_In_P (Is_Real_Type'Access);
1409 elsif Opnd_Type = Any_String then
1410 Orig_Type := Type_In_P (Is_String_Type'Access);
1412 elsif Opnd_Type = Any_Access then
1413 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1415 elsif Opnd_Type = Any_Composite then
1416 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1418 if Present (Orig_Type) then
1419 if Has_Private_Component (Orig_Type) then
1422 Set_Etype (Act1, Orig_Type);
1425 Set_Etype (Act2, Orig_Type);
1434 Error := No (Orig_Type);
1437 elsif Ekind (Opnd_Type) = E_Allocator_Type
1438 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1442 -- If the type is defined elsewhere, and the operator is not
1443 -- defined in the given scope (by a renaming declaration, e.g.)
1444 -- then this is an error as well. If an extension of System is
1445 -- present, and the type may be defined there, Pack must be
1448 elsif Scope (Opnd_Type) /= Pack
1449 and then Scope (Op_Id) /= Pack
1450 and then (No (System_Aux_Id)
1451 or else Scope (Opnd_Type) /= System_Aux_Id
1452 or else Pack /= Scope (System_Aux_Id))
1454 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1457 Error := not Operand_Type_In_Scope (Pack);
1460 elsif Pack = Standard_Standard
1461 and then not Operand_Type_In_Scope (Standard_Standard)
1468 Error_Msg_Node_2 := Pack;
1470 ("& not declared in&", N, Selector_Name (Name (N)));
1471 Set_Etype (N, Any_Type);
1474 -- Detect a mismatch between the context type and the result type
1475 -- in the named package, which is otherwise not detected if the
1476 -- operands are universal. Check is only needed if source entity is
1477 -- an operator, not a function that renames an operator.
1479 elsif Nkind (Parent (N)) /= N_Type_Conversion
1480 and then Ekind (Entity (Name (N))) = E_Operator
1481 and then Is_Numeric_Type (Typ)
1482 and then not Is_Universal_Numeric_Type (Typ)
1483 and then Scope (Base_Type (Typ)) /= Pack
1484 and then not In_Instance
1486 if Is_Fixed_Point_Type (Typ)
1487 and then (Op_Name = Name_Op_Multiply
1489 Op_Name = Name_Op_Divide)
1491 -- Already checked above
1495 -- Operator may be defined in an extension of System
1497 elsif Present (System_Aux_Id)
1498 and then Scope (Opnd_Type) = System_Aux_Id
1503 -- Could we use Wrong_Type here??? (this would require setting
1504 -- Etype (N) to the actual type found where Typ was expected).
1506 Error_Msg_NE ("expect }", N, Typ);
1511 Set_Chars (Op_Node, Op_Name);
1513 if not Is_Private_Type (Etype (N)) then
1514 Set_Etype (Op_Node, Base_Type (Etype (N)));
1516 Set_Etype (Op_Node, Etype (N));
1519 -- If this is a call to a function that renames a predefined equality,
1520 -- the renaming declaration provides a type that must be used to
1521 -- resolve the operands. This must be done now because resolution of
1522 -- the equality node will not resolve any remaining ambiguity, and it
1523 -- assumes that the first operand is not overloaded.
1525 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1526 and then Ekind (Func) = E_Function
1527 and then Is_Overloaded (Act1)
1529 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1530 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1533 Set_Entity (Op_Node, Op_Id);
1534 Generate_Reference (Op_Id, N, ' ');
1536 -- Do rewrite setting Comes_From_Source on the result if the original
1537 -- call came from source. Although it is not strictly the case that the
1538 -- operator as such comes from the source, logically it corresponds
1539 -- exactly to the function call in the source, so it should be marked
1540 -- this way (e.g. to make sure that validity checks work fine).
1543 CS : constant Boolean := Comes_From_Source (N);
1545 Rewrite (N, Op_Node);
1546 Set_Comes_From_Source (N, CS);
1549 -- If this is an arithmetic operator and the result type is private,
1550 -- the operands and the result must be wrapped in conversion to
1551 -- expose the underlying numeric type and expand the proper checks,
1552 -- e.g. on division.
1554 if Is_Private_Type (Typ) then
1556 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1557 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1558 Resolve_Intrinsic_Operator (N, Typ);
1560 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1561 Resolve_Intrinsic_Unary_Operator (N, Typ);
1569 end Make_Call_Into_Operator;
1575 function Operator_Kind
1577 Is_Binary : Boolean) return Node_Kind
1582 -- Use CASE statement or array???
1585 if Op_Name = Name_Op_And then
1587 elsif Op_Name = Name_Op_Or then
1589 elsif Op_Name = Name_Op_Xor then
1591 elsif Op_Name = Name_Op_Eq then
1593 elsif Op_Name = Name_Op_Ne then
1595 elsif Op_Name = Name_Op_Lt then
1597 elsif Op_Name = Name_Op_Le then
1599 elsif Op_Name = Name_Op_Gt then
1601 elsif Op_Name = Name_Op_Ge then
1603 elsif Op_Name = Name_Op_Add then
1605 elsif Op_Name = Name_Op_Subtract then
1606 Kind := N_Op_Subtract;
1607 elsif Op_Name = Name_Op_Concat then
1608 Kind := N_Op_Concat;
1609 elsif Op_Name = Name_Op_Multiply then
1610 Kind := N_Op_Multiply;
1611 elsif Op_Name = Name_Op_Divide then
1612 Kind := N_Op_Divide;
1613 elsif Op_Name = Name_Op_Mod then
1615 elsif Op_Name = Name_Op_Rem then
1617 elsif Op_Name = Name_Op_Expon then
1620 raise Program_Error;
1626 if Op_Name = Name_Op_Add then
1628 elsif Op_Name = Name_Op_Subtract then
1630 elsif Op_Name = Name_Op_Abs then
1632 elsif Op_Name = Name_Op_Not then
1635 raise Program_Error;
1642 ----------------------------
1643 -- Preanalyze_And_Resolve --
1644 ----------------------------
1646 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1647 Save_Full_Analysis : constant Boolean := Full_Analysis;
1650 Full_Analysis := False;
1651 Expander_Mode_Save_And_Set (False);
1653 -- We suppress all checks for this analysis, since the checks will
1654 -- be applied properly, and in the right location, when the default
1655 -- expression is reanalyzed and reexpanded later on.
1657 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1659 Expander_Mode_Restore;
1660 Full_Analysis := Save_Full_Analysis;
1661 end Preanalyze_And_Resolve;
1663 -- Version without context type
1665 procedure Preanalyze_And_Resolve (N : Node_Id) is
1666 Save_Full_Analysis : constant Boolean := Full_Analysis;
1669 Full_Analysis := False;
1670 Expander_Mode_Save_And_Set (False);
1673 Resolve (N, Etype (N), Suppress => All_Checks);
1675 Expander_Mode_Restore;
1676 Full_Analysis := Save_Full_Analysis;
1677 end Preanalyze_And_Resolve;
1679 ----------------------------------
1680 -- Replace_Actual_Discriminants --
1681 ----------------------------------
1683 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1684 Loc : constant Source_Ptr := Sloc (N);
1685 Tsk : Node_Id := Empty;
1687 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1688 -- Comment needed???
1694 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1698 if Nkind (Nod) = N_Identifier then
1699 Ent := Entity (Nod);
1702 and then Ekind (Ent) = E_Discriminant
1705 Make_Selected_Component (Loc,
1706 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1707 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1709 Set_Etype (Nod, Etype (Ent));
1717 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1719 -- Start of processing for Replace_Actual_Discriminants
1722 if not Expander_Active then
1726 if Nkind (Name (N)) = N_Selected_Component then
1727 Tsk := Prefix (Name (N));
1729 elsif Nkind (Name (N)) = N_Indexed_Component then
1730 Tsk := Prefix (Prefix (Name (N)));
1736 Replace_Discrs (Default);
1738 end Replace_Actual_Discriminants;
1744 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1745 Ambiguous : Boolean := False;
1746 Ctx_Type : Entity_Id := Typ;
1747 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1748 Err_Type : Entity_Id := Empty;
1749 Found : Boolean := False;
1752 I1 : Interp_Index := 0; -- prevent junk warning
1755 Seen : Entity_Id := Empty; -- prevent junk warning
1757 procedure Build_Explicit_Dereference
1760 -- AI05-139: Names with implicit dereference. If the expression N is a
1761 -- reference type and the context imposes the corresponding designated
1762 -- type, convert N into N.Disc.all. Such expressions are always over-
1763 -- loaded with both interpretations, and the dereference interpretation
1764 -- carries the name of the reference discriminant.
1766 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1767 -- Determine whether a node comes from a predefined library unit or
1770 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1771 -- Try and fix up a literal so that it matches its expected type. New
1772 -- literals are manufactured if necessary to avoid cascaded errors.
1774 procedure Report_Ambiguous_Argument;
1775 -- Additional diagnostics when an ambiguous call has an ambiguous
1776 -- argument (typically a controlling actual).
1778 procedure Resolution_Failed;
1779 -- Called when attempt at resolving current expression fails
1781 --------------------------------
1782 -- Build_Explicit_Dereference --
1783 --------------------------------
1785 procedure Build_Explicit_Dereference
1789 Loc : constant Source_Ptr := Sloc (Expr);
1792 Set_Is_Overloaded (Expr, False);
1794 Make_Explicit_Dereference (Loc,
1796 Make_Selected_Component (Loc,
1797 Prefix => Relocate_Node (Expr),
1798 Selector_Name => New_Occurrence_Of (Disc, Loc))));
1800 Set_Etype (Prefix (Expr), Etype (Disc));
1801 Set_Etype (Expr, Typ);
1802 end Build_Explicit_Dereference;
1804 ------------------------------------
1805 -- Comes_From_Predefined_Lib_Unit --
1806 -------------------------------------
1808 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1811 Sloc (Nod) = Standard_Location
1812 or else Is_Predefined_File_Name
1813 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1814 end Comes_From_Predefined_Lib_Unit;
1816 --------------------
1817 -- Patch_Up_Value --
1818 --------------------
1820 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1822 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1824 Make_Real_Literal (Sloc (N),
1825 Realval => UR_From_Uint (Intval (N))));
1826 Set_Etype (N, Universal_Real);
1827 Set_Is_Static_Expression (N);
1829 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1831 Make_Integer_Literal (Sloc (N),
1832 Intval => UR_To_Uint (Realval (N))));
1833 Set_Etype (N, Universal_Integer);
1834 Set_Is_Static_Expression (N);
1836 elsif Nkind (N) = N_String_Literal
1837 and then Is_Character_Type (Typ)
1839 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1841 Make_Character_Literal (Sloc (N),
1843 Char_Literal_Value =>
1844 UI_From_Int (Character'Pos ('A'))));
1845 Set_Etype (N, Any_Character);
1846 Set_Is_Static_Expression (N);
1848 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1850 Make_String_Literal (Sloc (N),
1851 Strval => End_String));
1853 elsif Nkind (N) = N_Range then
1854 Patch_Up_Value (Low_Bound (N), Typ);
1855 Patch_Up_Value (High_Bound (N), Typ);
1859 -------------------------------
1860 -- Report_Ambiguous_Argument --
1861 -------------------------------
1863 procedure Report_Ambiguous_Argument is
1864 Arg : constant Node_Id := First (Parameter_Associations (N));
1869 if Nkind (Arg) = N_Function_Call
1870 and then Is_Entity_Name (Name (Arg))
1871 and then Is_Overloaded (Name (Arg))
1873 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1875 -- Could use comments on what is going on here???
1877 Get_First_Interp (Name (Arg), I, It);
1878 while Present (It.Nam) loop
1879 Error_Msg_Sloc := Sloc (It.Nam);
1881 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1882 Error_Msg_N ("interpretation (inherited) #!", Arg);
1884 Error_Msg_N ("interpretation #!", Arg);
1887 Get_Next_Interp (I, It);
1890 end Report_Ambiguous_Argument;
1892 -----------------------
1893 -- Resolution_Failed --
1894 -----------------------
1896 procedure Resolution_Failed is
1898 Patch_Up_Value (N, Typ);
1900 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1901 Set_Is_Overloaded (N, False);
1903 -- The caller will return without calling the expander, so we need
1904 -- to set the analyzed flag. Note that it is fine to set Analyzed
1905 -- to True even if we are in the middle of a shallow analysis,
1906 -- (see the spec of sem for more details) since this is an error
1907 -- situation anyway, and there is no point in repeating the
1908 -- analysis later (indeed it won't work to repeat it later, since
1909 -- we haven't got a clear resolution of which entity is being
1912 Set_Analyzed (N, True);
1914 end Resolution_Failed;
1916 -- Start of processing for Resolve
1923 -- Access attribute on remote subprogram cannot be used for a non-remote
1924 -- access-to-subprogram type.
1926 if Nkind (N) = N_Attribute_Reference
1927 and then (Attribute_Name (N) = Name_Access or else
1928 Attribute_Name (N) = Name_Unrestricted_Access or else
1929 Attribute_Name (N) = Name_Unchecked_Access)
1930 and then Comes_From_Source (N)
1931 and then Is_Entity_Name (Prefix (N))
1932 and then Is_Subprogram (Entity (Prefix (N)))
1933 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1934 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1937 ("prefix must statically denote a non-remote subprogram", N);
1940 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1942 -- If the context is a Remote_Access_To_Subprogram, access attributes
1943 -- must be resolved with the corresponding fat pointer. There is no need
1944 -- to check for the attribute name since the return type of an
1945 -- attribute is never a remote type.
1947 if Nkind (N) = N_Attribute_Reference
1948 and then Comes_From_Source (N)
1949 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
1952 Attr : constant Attribute_Id :=
1953 Get_Attribute_Id (Attribute_Name (N));
1954 Pref : constant Node_Id := Prefix (N);
1957 Is_Remote : Boolean := True;
1960 -- Check that Typ is a remote access-to-subprogram type
1962 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1964 -- Prefix (N) must statically denote a remote subprogram
1965 -- declared in a package specification.
1967 if Attr = Attribute_Access then
1968 Decl := Unit_Declaration_Node (Entity (Pref));
1970 if Nkind (Decl) = N_Subprogram_Body then
1971 Spec := Corresponding_Spec (Decl);
1973 if not No (Spec) then
1974 Decl := Unit_Declaration_Node (Spec);
1978 Spec := Parent (Decl);
1980 if not Is_Entity_Name (Prefix (N))
1981 or else Nkind (Spec) /= N_Package_Specification
1983 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1987 ("prefix must statically denote a remote subprogram ",
1992 -- If we are generating code for a distributed program.
1993 -- perform semantic checks against the corresponding
1996 if (Attr = Attribute_Access or else
1997 Attr = Attribute_Unchecked_Access or else
1998 Attr = Attribute_Unrestricted_Access)
1999 and then Expander_Active
2000 and then Get_PCS_Name /= Name_No_DSA
2002 Check_Subtype_Conformant
2003 (New_Id => Entity (Prefix (N)),
2004 Old_Id => Designated_Type
2005 (Corresponding_Remote_Type (Typ)),
2009 Process_Remote_AST_Attribute (N, Typ);
2016 Debug_A_Entry ("resolving ", N);
2018 if Comes_From_Source (N) then
2019 if Is_Fixed_Point_Type (Typ) then
2020 Check_Restriction (No_Fixed_Point, N);
2022 elsif Is_Floating_Point_Type (Typ)
2023 and then Typ /= Universal_Real
2024 and then Typ /= Any_Real
2026 Check_Restriction (No_Floating_Point, N);
2030 -- Return if already analyzed
2032 if Analyzed (N) then
2033 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2036 -- Return if type = Any_Type (previous error encountered)
2038 elsif Etype (N) = Any_Type then
2039 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2043 Check_Parameterless_Call (N);
2045 -- If not overloaded, then we know the type, and all that needs doing
2046 -- is to check that this type is compatible with the context.
2048 if not Is_Overloaded (N) then
2049 Found := Covers (Typ, Etype (N));
2050 Expr_Type := Etype (N);
2052 -- In the overloaded case, we must select the interpretation that
2053 -- is compatible with the context (i.e. the type passed to Resolve)
2056 -- Loop through possible interpretations
2058 Get_First_Interp (N, I, It);
2059 Interp_Loop : while Present (It.Typ) loop
2061 -- We are only interested in interpretations that are compatible
2062 -- with the expected type, any other interpretations are ignored.
2064 if not Covers (Typ, It.Typ) then
2065 if Debug_Flag_V then
2066 Write_Str (" interpretation incompatible with context");
2071 -- Skip the current interpretation if it is disabled by an
2072 -- abstract operator. This action is performed only when the
2073 -- type against which we are resolving is the same as the
2074 -- type of the interpretation.
2076 if Ada_Version >= Ada_2005
2077 and then It.Typ = Typ
2078 and then Typ /= Universal_Integer
2079 and then Typ /= Universal_Real
2080 and then Present (It.Abstract_Op)
2085 -- First matching interpretation
2091 Expr_Type := It.Typ;
2093 -- Matching interpretation that is not the first, maybe an
2094 -- error, but there are some cases where preference rules are
2095 -- used to choose between the two possibilities. These and
2096 -- some more obscure cases are handled in Disambiguate.
2099 -- If the current statement is part of a predefined library
2100 -- unit, then all interpretations which come from user level
2101 -- packages should not be considered.
2104 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
2109 Error_Msg_Sloc := Sloc (Seen);
2110 It1 := Disambiguate (N, I1, I, Typ);
2112 -- Disambiguation has succeeded. Skip the remaining
2115 if It1 /= No_Interp then
2117 Expr_Type := It1.Typ;
2119 while Present (It.Typ) loop
2120 Get_Next_Interp (I, It);
2124 -- Before we issue an ambiguity complaint, check for
2125 -- the case of a subprogram call where at least one
2126 -- of the arguments is Any_Type, and if so, suppress
2127 -- the message, since it is a cascaded error.
2129 if Nkind_In (N, N_Function_Call,
2130 N_Procedure_Call_Statement)
2137 A := First_Actual (N);
2138 while Present (A) loop
2141 if Nkind (E) = N_Parameter_Association then
2142 E := Explicit_Actual_Parameter (E);
2145 if Etype (E) = Any_Type then
2146 if Debug_Flag_V then
2147 Write_Str ("Any_Type in call");
2158 elsif Nkind (N) in N_Binary_Op
2159 and then (Etype (Left_Opnd (N)) = Any_Type
2160 or else Etype (Right_Opnd (N)) = Any_Type)
2164 elsif Nkind (N) in N_Unary_Op
2165 and then Etype (Right_Opnd (N)) = Any_Type
2170 -- Not that special case, so issue message using the
2171 -- flag Ambiguous to control printing of the header
2172 -- message only at the start of an ambiguous set.
2174 if not Ambiguous then
2175 if Nkind (N) = N_Function_Call
2176 and then Nkind (Name (N)) = N_Explicit_Dereference
2179 ("ambiguous expression "
2180 & "(cannot resolve indirect call)!", N);
2182 Error_Msg_NE -- CODEFIX
2183 ("ambiguous expression (cannot resolve&)!",
2189 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2191 ("\\possible interpretation (inherited)#!", N);
2193 Error_Msg_N -- CODEFIX
2194 ("\\possible interpretation#!", N);
2198 (N, N_Procedure_Call_Statement, N_Function_Call)
2199 and then Present (Parameter_Associations (N))
2201 Report_Ambiguous_Argument;
2205 Error_Msg_Sloc := Sloc (It.Nam);
2207 -- By default, the error message refers to the candidate
2208 -- interpretation. But if it is a predefined operator, it
2209 -- is implicitly declared at the declaration of the type
2210 -- of the operand. Recover the sloc of that declaration
2211 -- for the error message.
2213 if Nkind (N) in N_Op
2214 and then Scope (It.Nam) = Standard_Standard
2215 and then not Is_Overloaded (Right_Opnd (N))
2216 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2219 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2221 if Comes_From_Source (Err_Type)
2222 and then Present (Parent (Err_Type))
2224 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2227 elsif Nkind (N) in N_Binary_Op
2228 and then Scope (It.Nam) = Standard_Standard
2229 and then not Is_Overloaded (Left_Opnd (N))
2230 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2233 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2235 if Comes_From_Source (Err_Type)
2236 and then Present (Parent (Err_Type))
2238 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2241 -- If this is an indirect call, use the subprogram_type
2242 -- in the message, to have a meaningful location. Also
2243 -- indicate if this is an inherited operation, created
2244 -- by a type declaration.
2246 elsif Nkind (N) = N_Function_Call
2247 and then Nkind (Name (N)) = N_Explicit_Dereference
2248 and then Is_Type (It.Nam)
2252 Sloc (Associated_Node_For_Itype (Err_Type));
2257 if Nkind (N) in N_Op
2258 and then Scope (It.Nam) = Standard_Standard
2259 and then Present (Err_Type)
2261 -- Special-case the message for universal_fixed
2262 -- operators, which are not declared with the type
2263 -- of the operand, but appear forever in Standard.
2265 if It.Typ = Universal_Fixed
2266 and then Scope (It.Nam) = Standard_Standard
2269 ("\\possible interpretation as " &
2270 "universal_fixed operation " &
2271 "(RM 4.5.5 (19))", N);
2274 ("\\possible interpretation (predefined)#!", N);
2278 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2281 ("\\possible interpretation (inherited)#!", N);
2283 Error_Msg_N -- CODEFIX
2284 ("\\possible interpretation#!", N);
2290 -- We have a matching interpretation, Expr_Type is the type
2291 -- from this interpretation, and Seen is the entity.
2293 -- For an operator, just set the entity name. The type will be
2294 -- set by the specific operator resolution routine.
2296 if Nkind (N) in N_Op then
2297 Set_Entity (N, Seen);
2298 Generate_Reference (Seen, N);
2300 elsif Nkind (N) = N_Case_Expression then
2301 Set_Etype (N, Expr_Type);
2303 elsif Nkind (N) = N_Character_Literal then
2304 Set_Etype (N, Expr_Type);
2306 elsif Nkind (N) = N_Conditional_Expression then
2307 Set_Etype (N, Expr_Type);
2309 -- AI05-0139-2: Expression is overloaded because type has
2310 -- implicit dereference. If type matches context, no implicit
2311 -- dereference is involved.
2313 elsif Has_Implicit_Dereference (Expr_Type) then
2314 Set_Etype (N, Expr_Type);
2315 Set_Is_Overloaded (N, False);
2318 elsif Is_Overloaded (N)
2319 and then Present (It.Nam)
2320 and then Ekind (It.Nam) = E_Discriminant
2321 and then Has_Implicit_Dereference (It.Nam)
2323 Build_Explicit_Dereference (N, It.Nam);
2325 -- For an explicit dereference, attribute reference, range,
2326 -- short-circuit form (which is not an operator node), or call
2327 -- with a name that is an explicit dereference, there is
2328 -- nothing to be done at this point.
2330 elsif Nkind_In (N, N_Explicit_Dereference,
2331 N_Attribute_Reference,
2333 N_Indexed_Component,
2336 N_Selected_Component,
2338 or else Nkind (Name (N)) = N_Explicit_Dereference
2342 -- For procedure or function calls, set the type of the name,
2343 -- and also the entity pointer for the prefix.
2345 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2346 and then Is_Entity_Name (Name (N))
2348 Set_Etype (Name (N), Expr_Type);
2349 Set_Entity (Name (N), Seen);
2350 Generate_Reference (Seen, Name (N));
2352 elsif Nkind (N) = N_Function_Call
2353 and then Nkind (Name (N)) = N_Selected_Component
2355 Set_Etype (Name (N), Expr_Type);
2356 Set_Entity (Selector_Name (Name (N)), Seen);
2357 Generate_Reference (Seen, Selector_Name (Name (N)));
2359 -- For all other cases, just set the type of the Name
2362 Set_Etype (Name (N), Expr_Type);
2369 -- Move to next interpretation
2371 exit Interp_Loop when No (It.Typ);
2373 Get_Next_Interp (I, It);
2374 end loop Interp_Loop;
2377 -- At this stage Found indicates whether or not an acceptable
2378 -- interpretation exists. If not, then we have an error, except that if
2379 -- the context is Any_Type as a result of some other error, then we
2380 -- suppress the error report.
2383 if Typ /= Any_Type then
2385 -- If type we are looking for is Void, then this is the procedure
2386 -- call case, and the error is simply that what we gave is not a
2387 -- procedure name (we think of procedure calls as expressions with
2388 -- types internally, but the user doesn't think of them this way!)
2390 if Typ = Standard_Void_Type then
2392 -- Special case message if function used as a procedure
2394 if Nkind (N) = N_Procedure_Call_Statement
2395 and then Is_Entity_Name (Name (N))
2396 and then Ekind (Entity (Name (N))) = E_Function
2399 ("cannot use function & in a procedure call",
2400 Name (N), Entity (Name (N)));
2402 -- Otherwise give general message (not clear what cases this
2403 -- covers, but no harm in providing for them!)
2406 Error_Msg_N ("expect procedure name in procedure call", N);
2411 -- Otherwise we do have a subexpression with the wrong type
2413 -- Check for the case of an allocator which uses an access type
2414 -- instead of the designated type. This is a common error and we
2415 -- specialize the message, posting an error on the operand of the
2416 -- allocator, complaining that we expected the designated type of
2419 elsif Nkind (N) = N_Allocator
2420 and then Ekind (Typ) in Access_Kind
2421 and then Ekind (Etype (N)) in Access_Kind
2422 and then Designated_Type (Etype (N)) = Typ
2424 Wrong_Type (Expression (N), Designated_Type (Typ));
2427 -- Check for view mismatch on Null in instances, for which the
2428 -- view-swapping mechanism has no identifier.
2430 elsif (In_Instance or else In_Inlined_Body)
2431 and then (Nkind (N) = N_Null)
2432 and then Is_Private_Type (Typ)
2433 and then Is_Access_Type (Full_View (Typ))
2435 Resolve (N, Full_View (Typ));
2439 -- Check for an aggregate. Sometimes we can get bogus aggregates
2440 -- from misuse of parentheses, and we are about to complain about
2441 -- the aggregate without even looking inside it.
2443 -- Instead, if we have an aggregate of type Any_Composite, then
2444 -- analyze and resolve the component fields, and then only issue
2445 -- another message if we get no errors doing this (otherwise
2446 -- assume that the errors in the aggregate caused the problem).
2448 elsif Nkind (N) = N_Aggregate
2449 and then Etype (N) = Any_Composite
2451 -- Disable expansion in any case. If there is a type mismatch
2452 -- it may be fatal to try to expand the aggregate. The flag
2453 -- would otherwise be set to false when the error is posted.
2455 Expander_Active := False;
2458 procedure Check_Aggr (Aggr : Node_Id);
2459 -- Check one aggregate, and set Found to True if we have a
2460 -- definite error in any of its elements
2462 procedure Check_Elmt (Aelmt : Node_Id);
2463 -- Check one element of aggregate and set Found to True if
2464 -- we definitely have an error in the element.
2470 procedure Check_Aggr (Aggr : Node_Id) is
2474 if Present (Expressions (Aggr)) then
2475 Elmt := First (Expressions (Aggr));
2476 while Present (Elmt) loop
2482 if Present (Component_Associations (Aggr)) then
2483 Elmt := First (Component_Associations (Aggr));
2484 while Present (Elmt) loop
2486 -- If this is a default-initialized component, then
2487 -- there is nothing to check. The box will be
2488 -- replaced by the appropriate call during late
2491 if not Box_Present (Elmt) then
2492 Check_Elmt (Expression (Elmt));
2504 procedure Check_Elmt (Aelmt : Node_Id) is
2506 -- If we have a nested aggregate, go inside it (to
2507 -- attempt a naked analyze-resolve of the aggregate can
2508 -- cause undesirable cascaded errors). Do not resolve
2509 -- expression if it needs a type from context, as for
2510 -- integer * fixed expression.
2512 if Nkind (Aelmt) = N_Aggregate then
2518 if not Is_Overloaded (Aelmt)
2519 and then Etype (Aelmt) /= Any_Fixed
2524 if Etype (Aelmt) = Any_Type then
2535 -- If an error message was issued already, Found got reset to
2536 -- True, so if it is still False, issue standard Wrong_Type msg.
2539 if Is_Overloaded (N)
2540 and then Nkind (N) = N_Function_Call
2543 Subp_Name : Node_Id;
2545 if Is_Entity_Name (Name (N)) then
2546 Subp_Name := Name (N);
2548 elsif Nkind (Name (N)) = N_Selected_Component then
2550 -- Protected operation: retrieve operation name
2552 Subp_Name := Selector_Name (Name (N));
2555 raise Program_Error;
2558 Error_Msg_Node_2 := Typ;
2559 Error_Msg_NE ("no visible interpretation of&" &
2560 " matches expected type&", N, Subp_Name);
2563 if All_Errors_Mode then
2565 Index : Interp_Index;
2569 Error_Msg_N ("\\possible interpretations:", N);
2571 Get_First_Interp (Name (N), Index, It);
2572 while Present (It.Nam) loop
2573 Error_Msg_Sloc := Sloc (It.Nam);
2574 Error_Msg_Node_2 := It.Nam;
2576 ("\\ type& for & declared#", N, It.Typ);
2577 Get_Next_Interp (Index, It);
2582 Error_Msg_N ("\use -gnatf for details", N);
2586 Wrong_Type (N, Typ);
2594 -- Test if we have more than one interpretation for the context
2596 elsif Ambiguous then
2600 -- Here we have an acceptable interpretation for the context
2603 -- Propagate type information and normalize tree for various
2604 -- predefined operations. If the context only imposes a class of
2605 -- types, rather than a specific type, propagate the actual type
2608 if Typ = Any_Integer or else
2609 Typ = Any_Boolean or else
2610 Typ = Any_Modular or else
2611 Typ = Any_Real or else
2614 Ctx_Type := Expr_Type;
2616 -- Any_Fixed is legal in a real context only if a specific fixed-
2617 -- point type is imposed. If Norman Cohen can be confused by this,
2618 -- it deserves a separate message.
2621 and then Expr_Type = Any_Fixed
2623 Error_Msg_N ("illegal context for mixed mode operation", N);
2624 Set_Etype (N, Universal_Real);
2625 Ctx_Type := Universal_Real;
2629 -- A user-defined operator is transformed into a function call at
2630 -- this point, so that further processing knows that operators are
2631 -- really operators (i.e. are predefined operators). User-defined
2632 -- operators that are intrinsic are just renamings of the predefined
2633 -- ones, and need not be turned into calls either, but if they rename
2634 -- a different operator, we must transform the node accordingly.
2635 -- Instantiations of Unchecked_Conversion are intrinsic but are
2636 -- treated as functions, even if given an operator designator.
2638 if Nkind (N) in N_Op
2639 and then Present (Entity (N))
2640 and then Ekind (Entity (N)) /= E_Operator
2643 if not Is_Predefined_Op (Entity (N)) then
2644 Rewrite_Operator_As_Call (N, Entity (N));
2646 elsif Present (Alias (Entity (N)))
2648 Nkind (Parent (Parent (Entity (N)))) =
2649 N_Subprogram_Renaming_Declaration
2651 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2653 -- If the node is rewritten, it will be fully resolved in
2654 -- Rewrite_Renamed_Operator.
2656 if Analyzed (N) then
2662 case N_Subexpr'(Nkind (N)) is
2664 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2666 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2668 when N_Short_Circuit
2669 => Resolve_Short_Circuit (N, Ctx_Type);
2671 when N_Attribute_Reference
2672 => Resolve_Attribute (N, Ctx_Type);
2674 when N_Case_Expression
2675 => Resolve_Case_Expression (N, Ctx_Type);
2677 when N_Character_Literal
2678 => Resolve_Character_Literal (N, Ctx_Type);
2680 when N_Conditional_Expression
2681 => Resolve_Conditional_Expression (N, Ctx_Type);
2683 when N_Expanded_Name
2684 => Resolve_Entity_Name (N, Ctx_Type);
2686 when N_Explicit_Dereference
2687 => Resolve_Explicit_Dereference (N, Ctx_Type);
2689 when N_Expression_With_Actions
2690 => Resolve_Expression_With_Actions (N, Ctx_Type);
2692 when N_Extension_Aggregate
2693 => Resolve_Extension_Aggregate (N, Ctx_Type);
2695 when N_Function_Call
2696 => Resolve_Call (N, Ctx_Type);
2699 => Resolve_Entity_Name (N, Ctx_Type);
2701 when N_Indexed_Component
2702 => Resolve_Indexed_Component (N, Ctx_Type);
2704 when N_Integer_Literal
2705 => Resolve_Integer_Literal (N, Ctx_Type);
2707 when N_Membership_Test
2708 => Resolve_Membership_Op (N, Ctx_Type);
2710 when N_Null => Resolve_Null (N, Ctx_Type);
2712 when N_Op_And | N_Op_Or | N_Op_Xor
2713 => Resolve_Logical_Op (N, Ctx_Type);
2715 when N_Op_Eq | N_Op_Ne
2716 => Resolve_Equality_Op (N, Ctx_Type);
2718 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2719 => Resolve_Comparison_Op (N, Ctx_Type);
2721 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2723 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2724 N_Op_Divide | N_Op_Mod | N_Op_Rem
2726 => Resolve_Arithmetic_Op (N, Ctx_Type);
2728 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2730 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2732 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2733 => Resolve_Unary_Op (N, Ctx_Type);
2735 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2737 when N_Procedure_Call_Statement
2738 => Resolve_Call (N, Ctx_Type);
2740 when N_Operator_Symbol
2741 => Resolve_Operator_Symbol (N, Ctx_Type);
2743 when N_Qualified_Expression
2744 => Resolve_Qualified_Expression (N, Ctx_Type);
2746 when N_Quantified_Expression
2747 => Resolve_Quantified_Expression (N, Ctx_Type);
2749 when N_Raise_xxx_Error
2750 => Set_Etype (N, Ctx_Type);
2752 when N_Range => Resolve_Range (N, Ctx_Type);
2755 => Resolve_Real_Literal (N, Ctx_Type);
2757 when N_Reference => Resolve_Reference (N, Ctx_Type);
2759 when N_Selected_Component
2760 => Resolve_Selected_Component (N, Ctx_Type);
2762 when N_Slice => Resolve_Slice (N, Ctx_Type);
2764 when N_String_Literal
2765 => Resolve_String_Literal (N, Ctx_Type);
2767 when N_Subprogram_Info
2768 => Resolve_Subprogram_Info (N, Ctx_Type);
2770 when N_Type_Conversion
2771 => Resolve_Type_Conversion (N, Ctx_Type);
2773 when N_Unchecked_Expression =>
2774 Resolve_Unchecked_Expression (N, Ctx_Type);
2776 when N_Unchecked_Type_Conversion =>
2777 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2780 -- If the subexpression was replaced by a non-subexpression, then
2781 -- all we do is to expand it. The only legitimate case we know of
2782 -- is converting procedure call statement to entry call statements,
2783 -- but there may be others, so we are making this test general.
2785 if Nkind (N) not in N_Subexpr then
2786 Debug_A_Exit ("resolving ", N, " (done)");
2791 -- AI05-144-2: Check dangerous order dependence within an expression
2792 -- that is not a subexpression. Exclude RHS of an assignment, because
2793 -- both sides may have side-effects and the check must be performed
2794 -- over the statement.
2796 if Nkind (Parent (N)) not in N_Subexpr
2797 and then Nkind (Parent (N)) /= N_Assignment_Statement
2798 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
2800 Check_Order_Dependence;
2803 -- The expression is definitely NOT overloaded at this point, so
2804 -- we reset the Is_Overloaded flag to avoid any confusion when
2805 -- reanalyzing the node.
2807 Set_Is_Overloaded (N, False);
2809 -- Freeze expression type, entity if it is a name, and designated
2810 -- type if it is an allocator (RM 13.14(10,11,13)).
2812 -- Now that the resolution of the type of the node is complete, and
2813 -- we did not detect an error, we can expand this node. We skip the
2814 -- expand call if we are in a default expression, see section
2815 -- "Handling of Default Expressions" in Sem spec.
2817 Debug_A_Exit ("resolving ", N, " (done)");
2819 -- We unconditionally freeze the expression, even if we are in
2820 -- default expression mode (the Freeze_Expression routine tests this
2821 -- flag and only freezes static types if it is set).
2823 Freeze_Expression (N);
2825 -- Now we can do the expansion
2835 -- Version with check(s) suppressed
2837 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2839 if Suppress = All_Checks then
2841 Svg : constant Suppress_Array := Scope_Suppress;
2843 Scope_Suppress := (others => True);
2845 Scope_Suppress := Svg;
2850 Svg : constant Boolean := Scope_Suppress (Suppress);
2852 Scope_Suppress (Suppress) := True;
2854 Scope_Suppress (Suppress) := Svg;
2863 -- Version with implicit type
2865 procedure Resolve (N : Node_Id) is
2867 Resolve (N, Etype (N));
2870 ---------------------
2871 -- Resolve_Actuals --
2872 ---------------------
2874 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2875 Loc : constant Source_Ptr := Sloc (N);
2880 Prev : Node_Id := Empty;
2883 procedure Check_Argument_Order;
2884 -- Performs a check for the case where the actuals are all simple
2885 -- identifiers that correspond to the formal names, but in the wrong
2886 -- order, which is considered suspicious and cause for a warning.
2888 procedure Check_Prefixed_Call;
2889 -- If the original node is an overloaded call in prefix notation,
2890 -- insert an 'Access or a dereference as needed over the first actual.
2891 -- Try_Object_Operation has already verified that there is a valid
2892 -- interpretation, but the form of the actual can only be determined
2893 -- once the primitive operation is identified.
2895 procedure Insert_Default;
2896 -- If the actual is missing in a call, insert in the actuals list
2897 -- an instance of the default expression. The insertion is always
2898 -- a named association.
2900 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2901 -- Check whether T1 and T2, or their full views, are derived from a
2902 -- common type. Used to enforce the restrictions on array conversions
2905 function Static_Concatenation (N : Node_Id) return Boolean;
2906 -- Predicate to determine whether an actual that is a concatenation
2907 -- will be evaluated statically and does not need a transient scope.
2908 -- This must be determined before the actual is resolved and expanded
2909 -- because if needed the transient scope must be introduced earlier.
2911 --------------------------
2912 -- Check_Argument_Order --
2913 --------------------------
2915 procedure Check_Argument_Order is
2917 -- Nothing to do if no parameters, or original node is neither a
2918 -- function call nor a procedure call statement (happens in the
2919 -- operator-transformed-to-function call case), or the call does
2920 -- not come from source, or this warning is off.
2922 if not Warn_On_Parameter_Order
2923 or else No (Parameter_Associations (N))
2924 or else not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2926 or else not Comes_From_Source (N)
2932 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2935 -- Nothing to do if only one parameter
2941 -- Here if at least two arguments
2944 Actuals : array (1 .. Nargs) of Node_Id;
2948 Wrong_Order : Boolean := False;
2949 -- Set True if an out of order case is found
2952 -- Collect identifier names of actuals, fail if any actual is
2953 -- not a simple identifier, and record max length of name.
2955 Actual := First (Parameter_Associations (N));
2956 for J in Actuals'Range loop
2957 if Nkind (Actual) /= N_Identifier then
2960 Actuals (J) := Actual;
2965 -- If we got this far, all actuals are identifiers and the list
2966 -- of their names is stored in the Actuals array.
2968 Formal := First_Formal (Nam);
2969 for J in Actuals'Range loop
2971 -- If we ran out of formals, that's odd, probably an error
2972 -- which will be detected elsewhere, but abandon the search.
2978 -- If name matches and is in order OK
2980 if Chars (Formal) = Chars (Actuals (J)) then
2984 -- If no match, see if it is elsewhere in list and if so
2985 -- flag potential wrong order if type is compatible.
2987 for K in Actuals'Range loop
2988 if Chars (Formal) = Chars (Actuals (K))
2990 Has_Compatible_Type (Actuals (K), Etype (Formal))
2992 Wrong_Order := True;
3002 <<Continue>> Next_Formal (Formal);
3005 -- If Formals left over, also probably an error, skip warning
3007 if Present (Formal) then
3011 -- Here we give the warning if something was out of order
3015 ("actuals for this call may be in wrong order?", N);
3019 end Check_Argument_Order;
3021 -------------------------
3022 -- Check_Prefixed_Call --
3023 -------------------------
3025 procedure Check_Prefixed_Call is
3026 Act : constant Node_Id := First_Actual (N);
3027 A_Type : constant Entity_Id := Etype (Act);
3028 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3029 Orig : constant Node_Id := Original_Node (N);
3033 -- Check whether the call is a prefixed call, with or without
3034 -- additional actuals.
3036 if Nkind (Orig) = N_Selected_Component
3038 (Nkind (Orig) = N_Indexed_Component
3039 and then Nkind (Prefix (Orig)) = N_Selected_Component
3040 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3041 and then Is_Entity_Name (Act)
3042 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3044 if Is_Access_Type (A_Type)
3045 and then not Is_Access_Type (F_Type)
3047 -- Introduce dereference on object in prefix
3050 Make_Explicit_Dereference (Sloc (Act),
3051 Prefix => Relocate_Node (Act));
3052 Rewrite (Act, New_A);
3055 elsif Is_Access_Type (F_Type)
3056 and then not Is_Access_Type (A_Type)
3058 -- Introduce an implicit 'Access in prefix
3060 if not Is_Aliased_View (Act) then
3062 ("object in prefixed call to& must be aliased"
3063 & " (RM-2005 4.3.1 (13))",
3068 Make_Attribute_Reference (Loc,
3069 Attribute_Name => Name_Access,
3070 Prefix => Relocate_Node (Act)));
3075 end Check_Prefixed_Call;
3077 --------------------
3078 -- Insert_Default --
3079 --------------------
3081 procedure Insert_Default is
3086 -- Missing argument in call, nothing to insert
3088 if No (Default_Value (F)) then
3092 -- Note that we do a full New_Copy_Tree, so that any associated
3093 -- Itypes are properly copied. This may not be needed any more,
3094 -- but it does no harm as a safety measure! Defaults of a generic
3095 -- formal may be out of bounds of the corresponding actual (see
3096 -- cc1311b) and an additional check may be required.
3101 New_Scope => Current_Scope,
3104 if Is_Concurrent_Type (Scope (Nam))
3105 and then Has_Discriminants (Scope (Nam))
3107 Replace_Actual_Discriminants (N, Actval);
3110 if Is_Overloadable (Nam)
3111 and then Present (Alias (Nam))
3113 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3114 and then not Is_Tagged_Type (Etype (F))
3116 -- If default is a real literal, do not introduce a
3117 -- conversion whose effect may depend on the run-time
3118 -- size of universal real.
3120 if Nkind (Actval) = N_Real_Literal then
3121 Set_Etype (Actval, Base_Type (Etype (F)));
3123 Actval := Unchecked_Convert_To (Etype (F), Actval);
3127 if Is_Scalar_Type (Etype (F)) then
3128 Enable_Range_Check (Actval);
3131 Set_Parent (Actval, N);
3133 -- Resolve aggregates with their base type, to avoid scope
3134 -- anomalies: the subtype was first built in the subprogram
3135 -- declaration, and the current call may be nested.
3137 if Nkind (Actval) = N_Aggregate then
3138 Analyze_And_Resolve (Actval, Etype (F));
3140 Analyze_And_Resolve (Actval, Etype (Actval));
3144 Set_Parent (Actval, N);
3146 -- See note above concerning aggregates
3148 if Nkind (Actval) = N_Aggregate
3149 and then Has_Discriminants (Etype (Actval))
3151 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3153 -- Resolve entities with their own type, which may differ from
3154 -- the type of a reference in a generic context (the view
3155 -- swapping mechanism did not anticipate the re-analysis of
3156 -- default values in calls).
3158 elsif Is_Entity_Name (Actval) then
3159 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3162 Analyze_And_Resolve (Actval, Etype (Actval));
3166 -- If default is a tag indeterminate function call, propagate tag
3167 -- to obtain proper dispatching.
3169 if Is_Controlling_Formal (F)
3170 and then Nkind (Default_Value (F)) = N_Function_Call
3172 Set_Is_Controlling_Actual (Actval);
3177 -- If the default expression raises constraint error, then just
3178 -- silently replace it with an N_Raise_Constraint_Error node, since
3179 -- we already gave the warning on the subprogram spec. If node is
3180 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3181 -- the warnings removal machinery.
3183 if Raises_Constraint_Error (Actval)
3184 and then Nkind (Actval) /= N_Raise_Constraint_Error
3187 Make_Raise_Constraint_Error (Loc,
3188 Reason => CE_Range_Check_Failed));
3189 Set_Raises_Constraint_Error (Actval);
3190 Set_Etype (Actval, Etype (F));
3194 Make_Parameter_Association (Loc,
3195 Explicit_Actual_Parameter => Actval,
3196 Selector_Name => Make_Identifier (Loc, Chars (F)));
3198 -- Case of insertion is first named actual
3200 if No (Prev) or else
3201 Nkind (Parent (Prev)) /= N_Parameter_Association
3203 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3204 Set_First_Named_Actual (N, Actval);
3207 if No (Parameter_Associations (N)) then
3208 Set_Parameter_Associations (N, New_List (Assoc));
3210 Append (Assoc, Parameter_Associations (N));
3214 Insert_After (Prev, Assoc);
3217 -- Case of insertion is not first named actual
3220 Set_Next_Named_Actual
3221 (Assoc, Next_Named_Actual (Parent (Prev)));
3222 Set_Next_Named_Actual (Parent (Prev), Actval);
3223 Append (Assoc, Parameter_Associations (N));
3226 Mark_Rewrite_Insertion (Assoc);
3227 Mark_Rewrite_Insertion (Actval);
3236 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3237 FT1 : Entity_Id := T1;
3238 FT2 : Entity_Id := T2;
3241 if Is_Private_Type (T1)
3242 and then Present (Full_View (T1))
3244 FT1 := Full_View (T1);
3247 if Is_Private_Type (T2)
3248 and then Present (Full_View (T2))
3250 FT2 := Full_View (T2);
3253 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3256 --------------------------
3257 -- Static_Concatenation --
3258 --------------------------
3260 function Static_Concatenation (N : Node_Id) return Boolean is
3263 when N_String_Literal =>
3268 -- Concatenation is static when both operands are static and
3269 -- the concatenation operator is a predefined one.
3271 return Scope (Entity (N)) = Standard_Standard
3273 Static_Concatenation (Left_Opnd (N))
3275 Static_Concatenation (Right_Opnd (N));
3278 if Is_Entity_Name (N) then
3280 Ent : constant Entity_Id := Entity (N);
3282 return Ekind (Ent) = E_Constant
3283 and then Present (Constant_Value (Ent))
3285 Is_Static_Expression (Constant_Value (Ent));
3292 end Static_Concatenation;
3294 -- Start of processing for Resolve_Actuals
3297 Check_Argument_Order;
3299 if Present (First_Actual (N)) then
3300 Check_Prefixed_Call;
3303 A := First_Actual (N);
3304 F := First_Formal (Nam);
3305 while Present (F) loop
3306 if No (A) and then Needs_No_Actuals (Nam) then
3309 -- If we have an error in any actual or formal, indicated by a type
3310 -- of Any_Type, then abandon resolution attempt, and set result type
3313 elsif (Present (A) and then Etype (A) = Any_Type)
3314 or else Etype (F) = Any_Type
3316 Set_Etype (N, Any_Type);
3320 -- Case where actual is present
3322 -- If the actual is an entity, generate a reference to it now. We
3323 -- do this before the actual is resolved, because a formal of some
3324 -- protected subprogram, or a task discriminant, will be rewritten
3325 -- during expansion, and the source entity reference may be lost.
3328 and then Is_Entity_Name (A)
3329 and then Comes_From_Source (N)
3331 Orig_A := Entity (A);
3333 if Present (Orig_A) then
3334 if Is_Formal (Orig_A)
3335 and then Ekind (F) /= E_In_Parameter
3337 Generate_Reference (Orig_A, A, 'm');
3339 elsif not Is_Overloaded (A) then
3340 Generate_Reference (Orig_A, A);
3346 and then (Nkind (Parent (A)) /= N_Parameter_Association
3347 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3349 -- If style checking mode on, check match of formal name
3352 if Nkind (Parent (A)) = N_Parameter_Association then
3353 Check_Identifier (Selector_Name (Parent (A)), F);
3357 -- If the formal is Out or In_Out, do not resolve and expand the
3358 -- conversion, because it is subsequently expanded into explicit
3359 -- temporaries and assignments. However, the object of the
3360 -- conversion can be resolved. An exception is the case of tagged
3361 -- type conversion with a class-wide actual. In that case we want
3362 -- the tag check to occur and no temporary will be needed (no
3363 -- representation change can occur) and the parameter is passed by
3364 -- reference, so we go ahead and resolve the type conversion.
3365 -- Another exception is the case of reference to component or
3366 -- subcomponent of a bit-packed array, in which case we want to
3367 -- defer expansion to the point the in and out assignments are
3370 if Ekind (F) /= E_In_Parameter
3371 and then Nkind (A) = N_Type_Conversion
3372 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3374 if Ekind (F) = E_In_Out_Parameter
3375 and then Is_Array_Type (Etype (F))
3377 -- In a view conversion, the conversion must be legal in
3378 -- both directions, and thus both component types must be
3379 -- aliased, or neither (4.6 (8)).
3381 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3382 -- the privacy requirement should not apply to generic
3383 -- types, and should be checked in an instance. ARG query
3386 if Has_Aliased_Components (Etype (Expression (A))) /=
3387 Has_Aliased_Components (Etype (F))
3390 ("both component types in a view conversion must be"
3391 & " aliased, or neither", A);
3393 -- Comment here??? what set of cases???
3396 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3398 -- Check view conv between unrelated by ref array types
3400 if Is_By_Reference_Type (Etype (F))
3401 or else Is_By_Reference_Type (Etype (Expression (A)))
3404 ("view conversion between unrelated by reference " &
3405 "array types not allowed (\'A'I-00246)", A);
3407 -- In Ada 2005 mode, check view conversion component
3408 -- type cannot be private, tagged, or volatile. Note
3409 -- that we only apply this to source conversions. The
3410 -- generated code can contain conversions which are
3411 -- not subject to this test, and we cannot extract the
3412 -- component type in such cases since it is not present.
3414 elsif Comes_From_Source (A)
3415 and then Ada_Version >= Ada_2005
3418 Comp_Type : constant Entity_Id :=
3420 (Etype (Expression (A)));
3422 if (Is_Private_Type (Comp_Type)
3423 and then not Is_Generic_Type (Comp_Type))
3424 or else Is_Tagged_Type (Comp_Type)
3425 or else Is_Volatile (Comp_Type)
3428 ("component type of a view conversion cannot"
3429 & " be private, tagged, or volatile"
3438 -- Resolve expression if conversion is all OK
3440 if (Conversion_OK (A)
3441 or else Valid_Conversion (A, Etype (A), Expression (A)))
3442 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3444 Resolve (Expression (A));
3447 -- If the actual is a function call that returns a limited
3448 -- unconstrained object that needs finalization, create a
3449 -- transient scope for it, so that it can receive the proper
3450 -- finalization list.
3452 elsif Nkind (A) = N_Function_Call
3453 and then Is_Limited_Record (Etype (F))
3454 and then not Is_Constrained (Etype (F))
3455 and then Expander_Active
3456 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3458 Establish_Transient_Scope (A, False);
3460 -- A small optimization: if one of the actuals is a concatenation
3461 -- create a block around a procedure call to recover stack space.
3462 -- This alleviates stack usage when several procedure calls in
3463 -- the same statement list use concatenation. We do not perform
3464 -- this wrapping for code statements, where the argument is a
3465 -- static string, and we want to preserve warnings involving
3466 -- sequences of such statements.
3468 elsif Nkind (A) = N_Op_Concat
3469 and then Nkind (N) = N_Procedure_Call_Statement
3470 and then Expander_Active
3472 not (Is_Intrinsic_Subprogram (Nam)
3473 and then Chars (Nam) = Name_Asm)
3474 and then not Static_Concatenation (A)
3476 Establish_Transient_Scope (A, False);
3477 Resolve (A, Etype (F));
3480 if Nkind (A) = N_Type_Conversion
3481 and then Is_Array_Type (Etype (F))
3482 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3484 (Is_Limited_Type (Etype (F))
3485 or else Is_Limited_Type (Etype (Expression (A))))
3488 ("conversion between unrelated limited array types " &
3489 "not allowed (\A\I-00246)", A);
3491 if Is_Limited_Type (Etype (F)) then
3492 Explain_Limited_Type (Etype (F), A);
3495 if Is_Limited_Type (Etype (Expression (A))) then
3496 Explain_Limited_Type (Etype (Expression (A)), A);
3500 -- (Ada 2005: AI-251): If the actual is an allocator whose
3501 -- directly designated type is a class-wide interface, we build
3502 -- an anonymous access type to use it as the type of the
3503 -- allocator. Later, when the subprogram call is expanded, if
3504 -- the interface has a secondary dispatch table the expander
3505 -- will add a type conversion to force the correct displacement
3508 if Nkind (A) = N_Allocator then
3510 DDT : constant Entity_Id :=
3511 Directly_Designated_Type (Base_Type (Etype (F)));
3513 New_Itype : Entity_Id;
3516 if Is_Class_Wide_Type (DDT)
3517 and then Is_Interface (DDT)
3519 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3520 Set_Etype (New_Itype, Etype (A));
3521 Set_Directly_Designated_Type (New_Itype,
3522 Directly_Designated_Type (Etype (A)));
3523 Set_Etype (A, New_Itype);
3526 -- Ada 2005, AI-162:If the actual is an allocator, the
3527 -- innermost enclosing statement is the master of the
3528 -- created object. This needs to be done with expansion
3529 -- enabled only, otherwise the transient scope will not
3530 -- be removed in the expansion of the wrapped construct.
3532 if (Is_Controlled (DDT) or else Has_Task (DDT))
3533 and then Expander_Active
3535 Establish_Transient_Scope (A, False);
3540 -- (Ada 2005): The call may be to a primitive operation of
3541 -- a tagged synchronized type, declared outside of the type.
3542 -- In this case the controlling actual must be converted to
3543 -- its corresponding record type, which is the formal type.
3544 -- The actual may be a subtype, either because of a constraint
3545 -- or because it is a generic actual, so use base type to
3546 -- locate concurrent type.
3548 F_Typ := Base_Type (Etype (F));
3550 if Is_Tagged_Type (F_Typ)
3551 and then (Is_Concurrent_Type (F_Typ)
3552 or else Is_Concurrent_Record_Type (F_Typ))
3554 -- If the actual is overloaded, look for an interpretation
3555 -- that has a synchronized type.
3557 if not Is_Overloaded (A) then
3558 A_Typ := Base_Type (Etype (A));
3562 Index : Interp_Index;
3566 Get_First_Interp (A, Index, It);
3567 while Present (It.Typ) loop
3568 if Is_Concurrent_Type (It.Typ)
3569 or else Is_Concurrent_Record_Type (It.Typ)
3571 A_Typ := Base_Type (It.Typ);
3575 Get_Next_Interp (Index, It);
3581 Full_A_Typ : Entity_Id;
3584 if Present (Full_View (A_Typ)) then
3585 Full_A_Typ := Base_Type (Full_View (A_Typ));
3587 Full_A_Typ := A_Typ;
3590 -- Tagged synchronized type (case 1): the actual is a
3593 if Is_Concurrent_Type (A_Typ)
3594 and then Corresponding_Record_Type (A_Typ) = F_Typ
3597 Unchecked_Convert_To
3598 (Corresponding_Record_Type (A_Typ), A));
3599 Resolve (A, Etype (F));
3601 -- Tagged synchronized type (case 2): the formal is a
3604 elsif Ekind (Full_A_Typ) = E_Record_Type
3606 (Corresponding_Concurrent_Type (Full_A_Typ))
3607 and then Is_Concurrent_Type (F_Typ)
3608 and then Present (Corresponding_Record_Type (F_Typ))
3609 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3611 Resolve (A, Corresponding_Record_Type (F_Typ));
3616 Resolve (A, Etype (F));
3621 -- not a synchronized operation.
3623 Resolve (A, Etype (F));
3630 if Comes_From_Source (Original_Node (N))
3631 and then Nkind_In (Original_Node (N), N_Function_Call,
3632 N_Procedure_Call_Statement)
3634 -- In formal mode, check that actual parameters matching
3635 -- formals of tagged types are objects (or ancestor type
3636 -- conversions of objects), not general expressions.
3638 if Is_Actual_Tagged_Parameter (A) then
3639 if Is_SPARK_Object_Reference (A) then
3642 elsif Nkind (A) = N_Type_Conversion then
3644 Operand : constant Node_Id := Expression (A);
3645 Operand_Typ : constant Entity_Id := Etype (Operand);
3646 Target_Typ : constant Entity_Id := A_Typ;
3649 if not Is_SPARK_Object_Reference (Operand) then
3650 Check_SPARK_Restriction
3651 ("object required", Operand);
3653 -- In formal mode, the only view conversions are those
3654 -- involving ancestor conversion of an extended type.
3657 (Is_Tagged_Type (Target_Typ)
3658 and then not Is_Class_Wide_Type (Target_Typ)
3659 and then Is_Tagged_Type (Operand_Typ)
3660 and then not Is_Class_Wide_Type (Operand_Typ)
3661 and then Is_Ancestor (Target_Typ, Operand_Typ))
3664 (F, E_Out_Parameter, E_In_Out_Parameter)
3666 Check_SPARK_Restriction
3667 ("ancestor conversion is the only permitted "
3668 & "view conversion", A);
3670 Check_SPARK_Restriction
3671 ("ancestor conversion required", A);
3680 Check_SPARK_Restriction ("object required", A);
3683 -- In formal mode, the only view conversions are those
3684 -- involving ancestor conversion of an extended type.
3686 elsif Nkind (A) = N_Type_Conversion
3687 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3689 Check_SPARK_Restriction
3690 ("ancestor conversion is the only permitted view "
3695 -- Save actual for subsequent check on order dependence, and
3696 -- indicate whether actual is modifiable. For AI05-0144-2.
3698 Save_Actual (A, Ekind (F) /= E_In_Parameter);
3700 -- For mode IN, if actual is an entity, and the type of the formal
3701 -- has warnings suppressed, then we reset Never_Set_In_Source for
3702 -- the calling entity. The reason for this is to catch cases like
3703 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3704 -- uses trickery to modify an IN parameter.
3706 if Ekind (F) = E_In_Parameter
3707 and then Is_Entity_Name (A)
3708 and then Present (Entity (A))
3709 and then Ekind (Entity (A)) = E_Variable
3710 and then Has_Warnings_Off (F_Typ)
3712 Set_Never_Set_In_Source (Entity (A), False);
3715 -- Perform error checks for IN and IN OUT parameters
3717 if Ekind (F) /= E_Out_Parameter then
3719 -- Check unset reference. For scalar parameters, it is clearly
3720 -- wrong to pass an uninitialized value as either an IN or
3721 -- IN-OUT parameter. For composites, it is also clearly an
3722 -- error to pass a completely uninitialized value as an IN
3723 -- parameter, but the case of IN OUT is trickier. We prefer
3724 -- not to give a warning here. For example, suppose there is
3725 -- a routine that sets some component of a record to False.
3726 -- It is perfectly reasonable to make this IN-OUT and allow
3727 -- either initialized or uninitialized records to be passed
3730 -- For partially initialized composite values, we also avoid
3731 -- warnings, since it is quite likely that we are passing a
3732 -- partially initialized value and only the initialized fields
3733 -- will in fact be read in the subprogram.
3735 if Is_Scalar_Type (A_Typ)
3736 or else (Ekind (F) = E_In_Parameter
3737 and then not Is_Partially_Initialized_Type (A_Typ))
3739 Check_Unset_Reference (A);
3742 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3743 -- actual to a nested call, since this is case of reading an
3744 -- out parameter, which is not allowed.
3746 if Ada_Version = Ada_83
3747 and then Is_Entity_Name (A)
3748 and then Ekind (Entity (A)) = E_Out_Parameter
3750 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3754 -- Case of OUT or IN OUT parameter
3756 if Ekind (F) /= E_In_Parameter then
3758 -- For an Out parameter, check for useless assignment. Note
3759 -- that we can't set Last_Assignment this early, because we may
3760 -- kill current values in Resolve_Call, and that call would
3761 -- clobber the Last_Assignment field.
3763 -- Note: call Warn_On_Useless_Assignment before doing the check
3764 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3765 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3766 -- reflects the last assignment, not this one!
3768 if Ekind (F) = E_Out_Parameter then
3769 if Warn_On_Modified_As_Out_Parameter (F)
3770 and then Is_Entity_Name (A)
3771 and then Present (Entity (A))
3772 and then Comes_From_Source (N)
3774 Warn_On_Useless_Assignment (Entity (A), A);
3778 -- Validate the form of the actual. Note that the call to
3779 -- Is_OK_Variable_For_Out_Formal generates the required
3780 -- reference in this case.
3782 -- A call to an initialization procedure for an aggregate
3783 -- component may initialize a nested component of a constant
3784 -- designated object. In this context the object is variable.
3786 if not Is_OK_Variable_For_Out_Formal (A)
3787 and then not Is_Init_Proc (Nam)
3789 Error_Msg_NE ("actual for& must be a variable", A, F);
3792 -- What's the following about???
3794 if Is_Entity_Name (A) then
3795 Kill_Checks (Entity (A));
3801 if Etype (A) = Any_Type then
3802 Set_Etype (N, Any_Type);
3806 -- Apply appropriate range checks for in, out, and in-out
3807 -- parameters. Out and in-out parameters also need a separate
3808 -- check, if there is a type conversion, to make sure the return
3809 -- value meets the constraints of the variable before the
3812 -- Gigi looks at the check flag and uses the appropriate types.
3813 -- For now since one flag is used there is an optimization which
3814 -- might not be done in the In Out case since Gigi does not do
3815 -- any analysis. More thought required about this ???
3817 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
3819 -- Apply predicate checks, unless this is a call to the
3820 -- predicate check function itself, which would cause an
3821 -- infinite recursion.
3823 if not (Ekind (Nam) = E_Function
3824 and then Has_Predicates (Nam))
3826 Apply_Predicate_Check (A, F_Typ);
3829 -- Apply required constraint checks
3831 if Is_Scalar_Type (Etype (A)) then
3832 Apply_Scalar_Range_Check (A, F_Typ);
3834 elsif Is_Array_Type (Etype (A)) then
3835 Apply_Length_Check (A, F_Typ);
3837 elsif Is_Record_Type (F_Typ)
3838 and then Has_Discriminants (F_Typ)
3839 and then Is_Constrained (F_Typ)
3840 and then (not Is_Derived_Type (F_Typ)
3841 or else Comes_From_Source (Nam))
3843 Apply_Discriminant_Check (A, F_Typ);
3845 elsif Is_Access_Type (F_Typ)
3846 and then Is_Array_Type (Designated_Type (F_Typ))
3847 and then Is_Constrained (Designated_Type (F_Typ))
3849 Apply_Length_Check (A, F_Typ);
3851 elsif Is_Access_Type (F_Typ)
3852 and then Has_Discriminants (Designated_Type (F_Typ))
3853 and then Is_Constrained (Designated_Type (F_Typ))
3855 Apply_Discriminant_Check (A, F_Typ);
3858 Apply_Range_Check (A, F_Typ);
3861 -- Ada 2005 (AI-231): Note that the controlling parameter case
3862 -- already existed in Ada 95, which is partially checked
3863 -- elsewhere (see Checks), and we don't want the warning
3864 -- message to differ.
3866 if Is_Access_Type (F_Typ)
3867 and then Can_Never_Be_Null (F_Typ)
3868 and then Known_Null (A)
3870 if Is_Controlling_Formal (F) then
3871 Apply_Compile_Time_Constraint_Error
3873 Msg => "null value not allowed here?",
3874 Reason => CE_Access_Check_Failed);
3876 elsif Ada_Version >= Ada_2005 then
3877 Apply_Compile_Time_Constraint_Error
3879 Msg => "(Ada 2005) null not allowed in "
3880 & "null-excluding formal?",
3881 Reason => CE_Null_Not_Allowed);
3886 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
3887 if Nkind (A) = N_Type_Conversion then
3888 if Is_Scalar_Type (A_Typ) then
3889 Apply_Scalar_Range_Check
3890 (Expression (A), Etype (Expression (A)), A_Typ);
3893 (Expression (A), Etype (Expression (A)), A_Typ);
3897 if Is_Scalar_Type (F_Typ) then
3898 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3899 elsif Is_Array_Type (F_Typ)
3900 and then Ekind (F) = E_Out_Parameter
3902 Apply_Length_Check (A, F_Typ);
3904 Apply_Range_Check (A, A_Typ, F_Typ);
3909 -- An actual associated with an access parameter is implicitly
3910 -- converted to the anonymous access type of the formal and must
3911 -- satisfy the legality checks for access conversions.
3913 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3914 if not Valid_Conversion (A, F_Typ, A) then
3916 ("invalid implicit conversion for access parameter", A);
3920 -- Check bad case of atomic/volatile argument (RM C.6(12))
3922 if Is_By_Reference_Type (Etype (F))
3923 and then Comes_From_Source (N)
3925 if Is_Atomic_Object (A)
3926 and then not Is_Atomic (Etype (F))
3929 ("cannot pass atomic argument to non-atomic formal",
3932 elsif Is_Volatile_Object (A)
3933 and then not Is_Volatile (Etype (F))
3936 ("cannot pass volatile argument to non-volatile formal",
3941 -- Check that subprograms don't have improper controlling
3942 -- arguments (RM 3.9.2 (9)).
3944 -- A primitive operation may have an access parameter of an
3945 -- incomplete tagged type, but a dispatching call is illegal
3946 -- if the type is still incomplete.
3948 if Is_Controlling_Formal (F) then
3949 Set_Is_Controlling_Actual (A);
3951 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3953 Desig : constant Entity_Id := Designated_Type (Etype (F));
3955 if Ekind (Desig) = E_Incomplete_Type
3956 and then No (Full_View (Desig))
3957 and then No (Non_Limited_View (Desig))
3960 ("premature use of incomplete type& " &
3961 "in dispatching call", A, Desig);
3966 elsif Nkind (A) = N_Explicit_Dereference then
3967 Validate_Remote_Access_To_Class_Wide_Type (A);
3970 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3971 and then not Is_Class_Wide_Type (F_Typ)
3972 and then not Is_Controlling_Formal (F)
3974 Error_Msg_N ("class-wide argument not allowed here!", A);
3976 if Is_Subprogram (Nam)
3977 and then Comes_From_Source (Nam)
3979 Error_Msg_Node_2 := F_Typ;
3981 ("& is not a dispatching operation of &!", A, Nam);
3984 -- Apply the checks described in 3.10.2(27): if the context is a
3985 -- specific access-to-object, the actual cannot be class-wide.
3986 -- Use base type to exclude access_to_subprogram cases.
3988 elsif Is_Access_Type (A_Typ)
3989 and then Is_Access_Type (F_Typ)
3990 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
3991 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3992 or else (Nkind (A) = N_Attribute_Reference
3994 Is_Class_Wide_Type (Etype (Prefix (A)))))
3995 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3996 and then not Is_Controlling_Formal (F)
3998 -- Disable these checks for call to imported C++ subprograms
4001 (Is_Entity_Name (Name (N))
4002 and then Is_Imported (Entity (Name (N)))
4003 and then Convention (Entity (Name (N))) = Convention_CPP)
4006 ("access to class-wide argument not allowed here!", A);
4008 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4009 Error_Msg_Node_2 := Designated_Type (F_Typ);
4011 ("& is not a dispatching operation of &!", A, Nam);
4017 -- If it is a named association, treat the selector_name as a
4018 -- proper identifier, and mark the corresponding entity. Ignore
4019 -- this reference in ALFA mode, as it refers to an entity not in
4020 -- scope at the point of reference, so the reference should be
4021 -- ignored for computing effects of subprograms.
4023 if Nkind (Parent (A)) = N_Parameter_Association
4024 and then not ALFA_Mode
4026 Set_Entity (Selector_Name (Parent (A)), F);
4027 Generate_Reference (F, Selector_Name (Parent (A)));
4028 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4029 Generate_Reference (F_Typ, N, ' ');
4034 if Ekind (F) /= E_Out_Parameter then
4035 Check_Unset_Reference (A);
4040 -- Case where actual is not present
4048 end Resolve_Actuals;
4050 -----------------------
4051 -- Resolve_Allocator --
4052 -----------------------
4054 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4055 Desig_T : constant Entity_Id := Designated_Type (Typ);
4056 E : constant Node_Id := Expression (N);
4058 Discrim : Entity_Id;
4061 Assoc : Node_Id := Empty;
4064 procedure Check_Allocator_Discrim_Accessibility
4065 (Disc_Exp : Node_Id;
4066 Alloc_Typ : Entity_Id);
4067 -- Check that accessibility level associated with an access discriminant
4068 -- initialized in an allocator by the expression Disc_Exp is not deeper
4069 -- than the level of the allocator type Alloc_Typ. An error message is
4070 -- issued if this condition is violated. Specialized checks are done for
4071 -- the cases of a constraint expression which is an access attribute or
4072 -- an access discriminant.
4074 function In_Dispatching_Context return Boolean;
4075 -- If the allocator is an actual in a call, it is allowed to be class-
4076 -- wide when the context is not because it is a controlling actual.
4078 -------------------------------------------
4079 -- Check_Allocator_Discrim_Accessibility --
4080 -------------------------------------------
4082 procedure Check_Allocator_Discrim_Accessibility
4083 (Disc_Exp : Node_Id;
4084 Alloc_Typ : Entity_Id)
4087 if Type_Access_Level (Etype (Disc_Exp)) >
4088 Type_Access_Level (Alloc_Typ)
4091 ("operand type has deeper level than allocator type", Disc_Exp);
4093 -- When the expression is an Access attribute the level of the prefix
4094 -- object must not be deeper than that of the allocator's type.
4096 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4097 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
4099 and then Object_Access_Level (Prefix (Disc_Exp))
4100 > Type_Access_Level (Alloc_Typ)
4103 ("prefix of attribute has deeper level than allocator type",
4106 -- When the expression is an access discriminant the check is against
4107 -- the level of the prefix object.
4109 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4110 and then Nkind (Disc_Exp) = N_Selected_Component
4111 and then Object_Access_Level (Prefix (Disc_Exp))
4112 > Type_Access_Level (Alloc_Typ)
4115 ("access discriminant has deeper level than allocator type",
4118 -- All other cases are legal
4123 end Check_Allocator_Discrim_Accessibility;
4125 ----------------------------
4126 -- In_Dispatching_Context --
4127 ----------------------------
4129 function In_Dispatching_Context return Boolean is
4130 Par : constant Node_Id := Parent (N);
4134 Nkind_In (Par, N_Function_Call,
4135 N_Procedure_Call_Statement)
4136 and then Is_Entity_Name (Name (Par))
4137 and then Is_Dispatching_Operation (Entity (Name (Par)));
4138 end In_Dispatching_Context;
4140 -- Start of processing for Resolve_Allocator
4143 -- Replace general access with specific type
4145 if Ekind (Etype (N)) = E_Allocator_Type then
4146 Set_Etype (N, Base_Type (Typ));
4149 if Is_Abstract_Type (Typ) then
4150 Error_Msg_N ("type of allocator cannot be abstract", N);
4153 -- For qualified expression, resolve the expression using the
4154 -- given subtype (nothing to do for type mark, subtype indication)
4156 if Nkind (E) = N_Qualified_Expression then
4157 if Is_Class_Wide_Type (Etype (E))
4158 and then not Is_Class_Wide_Type (Desig_T)
4159 and then not In_Dispatching_Context
4162 ("class-wide allocator not allowed for this access type", N);
4165 Resolve (Expression (E), Etype (E));
4166 Check_Unset_Reference (Expression (E));
4168 -- A qualified expression requires an exact match of the type,
4169 -- class-wide matching is not allowed.
4171 if (Is_Class_Wide_Type (Etype (Expression (E)))
4172 or else Is_Class_Wide_Type (Etype (E)))
4173 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4175 Wrong_Type (Expression (E), Etype (E));
4178 -- A special accessibility check is needed for allocators that
4179 -- constrain access discriminants. The level of the type of the
4180 -- expression used to constrain an access discriminant cannot be
4181 -- deeper than the type of the allocator (in contrast to access
4182 -- parameters, where the level of the actual can be arbitrary).
4184 -- We can't use Valid_Conversion to perform this check because
4185 -- in general the type of the allocator is unrelated to the type
4186 -- of the access discriminant.
4188 if Ekind (Typ) /= E_Anonymous_Access_Type
4189 or else Is_Local_Anonymous_Access (Typ)
4191 Subtyp := Entity (Subtype_Mark (E));
4193 Aggr := Original_Node (Expression (E));
4195 if Has_Discriminants (Subtyp)
4196 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4198 Discrim := First_Discriminant (Base_Type (Subtyp));
4200 -- Get the first component expression of the aggregate
4202 if Present (Expressions (Aggr)) then
4203 Disc_Exp := First (Expressions (Aggr));
4205 elsif Present (Component_Associations (Aggr)) then
4206 Assoc := First (Component_Associations (Aggr));
4208 if Present (Assoc) then
4209 Disc_Exp := Expression (Assoc);
4218 while Present (Discrim) and then Present (Disc_Exp) loop
4219 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4220 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4223 Next_Discriminant (Discrim);
4225 if Present (Discrim) then
4226 if Present (Assoc) then
4228 Disc_Exp := Expression (Assoc);
4230 elsif Present (Next (Disc_Exp)) then
4234 Assoc := First (Component_Associations (Aggr));
4236 if Present (Assoc) then
4237 Disc_Exp := Expression (Assoc);
4247 -- For a subtype mark or subtype indication, freeze the subtype
4250 Freeze_Expression (E);
4252 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4254 ("initialization required for access-to-constant allocator", N);
4257 -- A special accessibility check is needed for allocators that
4258 -- constrain access discriminants. The level of the type of the
4259 -- expression used to constrain an access discriminant cannot be
4260 -- deeper than the type of the allocator (in contrast to access
4261 -- parameters, where the level of the actual can be arbitrary).
4262 -- We can't use Valid_Conversion to perform this check because
4263 -- in general the type of the allocator is unrelated to the type
4264 -- of the access discriminant.
4266 if Nkind (Original_Node (E)) = N_Subtype_Indication
4267 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4268 or else Is_Local_Anonymous_Access (Typ))
4270 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4272 if Has_Discriminants (Subtyp) then
4273 Discrim := First_Discriminant (Base_Type (Subtyp));
4274 Constr := First (Constraints (Constraint (Original_Node (E))));
4275 while Present (Discrim) and then Present (Constr) loop
4276 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4277 if Nkind (Constr) = N_Discriminant_Association then
4278 Disc_Exp := Original_Node (Expression (Constr));
4280 Disc_Exp := Original_Node (Constr);
4283 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4286 Next_Discriminant (Discrim);
4293 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4294 -- check that the level of the type of the created object is not deeper
4295 -- than the level of the allocator's access type, since extensions can
4296 -- now occur at deeper levels than their ancestor types. This is a
4297 -- static accessibility level check; a run-time check is also needed in
4298 -- the case of an initialized allocator with a class-wide argument (see
4299 -- Expand_Allocator_Expression).
4301 if Ada_Version >= Ada_2005
4302 and then Is_Class_Wide_Type (Desig_T)
4305 Exp_Typ : Entity_Id;
4308 if Nkind (E) = N_Qualified_Expression then
4309 Exp_Typ := Etype (E);
4310 elsif Nkind (E) = N_Subtype_Indication then
4311 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4313 Exp_Typ := Entity (E);
4316 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4317 if In_Instance_Body then
4318 Error_Msg_N ("?type in allocator has deeper level than" &
4319 " designated class-wide type", E);
4320 Error_Msg_N ("\?Program_Error will be raised at run time",
4323 Make_Raise_Program_Error (Sloc (N),
4324 Reason => PE_Accessibility_Check_Failed));
4327 -- Do not apply Ada 2005 accessibility checks on a class-wide
4328 -- allocator if the type given in the allocator is a formal
4329 -- type. A run-time check will be performed in the instance.
4331 elsif not Is_Generic_Type (Exp_Typ) then
4332 Error_Msg_N ("type in allocator has deeper level than" &
4333 " designated class-wide type", E);
4339 -- Check for allocation from an empty storage pool
4341 if No_Pool_Assigned (Typ) then
4342 Error_Msg_N ("allocation from empty storage pool!", N);
4344 -- If the context is an unchecked conversion, as may happen within an
4345 -- inlined subprogram, the allocator is being resolved with its own
4346 -- anonymous type. In that case, if the target type has a specific
4347 -- storage pool, it must be inherited explicitly by the allocator type.
4349 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4350 and then No (Associated_Storage_Pool (Typ))
4352 Set_Associated_Storage_Pool
4353 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4356 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4357 Check_Restriction (No_Anonymous_Allocators, N);
4360 -- Check that an allocator with task parts isn't for a nested access
4361 -- type when restriction No_Task_Hierarchy applies.
4363 if not Is_Library_Level_Entity (Base_Type (Typ))
4364 and then Has_Task (Base_Type (Desig_T))
4366 Check_Restriction (No_Task_Hierarchy, N);
4369 -- An erroneous allocator may be rewritten as a raise Program_Error
4372 if Nkind (N) = N_Allocator then
4374 -- An anonymous access discriminant is the definition of a
4377 if Ekind (Typ) = E_Anonymous_Access_Type
4378 and then Nkind (Associated_Node_For_Itype (Typ)) =
4379 N_Discriminant_Specification
4382 Discr : constant Entity_Id :=
4383 Defining_Identifier (Associated_Node_For_Itype (Typ));
4386 -- Ada 2012 AI05-0052: If the designated type of the allocator
4387 -- is limited, then the allocator shall not be used to define
4388 -- the value of an access discriminant unless the discriminated
4389 -- type is immutably limited.
4391 if Ada_Version >= Ada_2012
4392 and then Is_Limited_Type (Desig_T)
4393 and then not Is_Immutably_Limited_Type (Scope (Discr))
4396 ("only immutably limited types can have anonymous "
4397 & "access discriminants designating a limited type", N);
4401 -- Avoid marking an allocator as a dynamic coextension if it is
4402 -- within a static construct.
4404 if not Is_Static_Coextension (N) then
4405 Set_Is_Dynamic_Coextension (N);
4408 -- Cleanup for potential static coextensions
4411 Set_Is_Dynamic_Coextension (N, False);
4412 Set_Is_Static_Coextension (N, False);
4416 -- Report a simple error: if the designated object is a local task,
4417 -- its body has not been seen yet, and its activation will fail
4418 -- an elaboration check.
4420 if Is_Task_Type (Desig_T)
4421 and then Scope (Base_Type (Desig_T)) = Current_Scope
4422 and then Is_Compilation_Unit (Current_Scope)
4423 and then Ekind (Current_Scope) = E_Package
4424 and then not In_Package_Body (Current_Scope)
4427 ("cannot activate task before body seen?", N);
4428 Error_Msg_N ("\Program_Error will be raised at run time?", N);
4430 end Resolve_Allocator;
4432 ---------------------------
4433 -- Resolve_Arithmetic_Op --
4434 ---------------------------
4436 -- Used for resolving all arithmetic operators except exponentiation
4438 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4439 L : constant Node_Id := Left_Opnd (N);
4440 R : constant Node_Id := Right_Opnd (N);
4441 TL : constant Entity_Id := Base_Type (Etype (L));
4442 TR : constant Entity_Id := Base_Type (Etype (R));
4446 B_Typ : constant Entity_Id := Base_Type (Typ);
4447 -- We do the resolution using the base type, because intermediate values
4448 -- in expressions always are of the base type, not a subtype of it.
4450 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4451 -- Returns True if N is in a context that expects "any real type"
4453 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4454 -- Return True iff given type is Integer or universal real/integer
4456 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4457 -- Choose type of integer literal in fixed-point operation to conform
4458 -- to available fixed-point type. T is the type of the other operand,
4459 -- which is needed to determine the expected type of N.
4461 procedure Set_Operand_Type (N : Node_Id);
4462 -- Set operand type to T if universal
4464 -------------------------------
4465 -- Expected_Type_Is_Any_Real --
4466 -------------------------------
4468 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4470 -- N is the expression after "delta" in a fixed_point_definition;
4473 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4474 N_Decimal_Fixed_Point_Definition,
4476 -- N is one of the bounds in a real_range_specification;
4479 N_Real_Range_Specification,
4481 -- N is the expression of a delta_constraint;
4484 N_Delta_Constraint);
4485 end Expected_Type_Is_Any_Real;
4487 -----------------------------
4488 -- Is_Integer_Or_Universal --
4489 -----------------------------
4491 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4493 Index : Interp_Index;
4497 if not Is_Overloaded (N) then
4499 return Base_Type (T) = Base_Type (Standard_Integer)
4500 or else T = Universal_Integer
4501 or else T = Universal_Real;
4503 Get_First_Interp (N, Index, It);
4504 while Present (It.Typ) loop
4505 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4506 or else It.Typ = Universal_Integer
4507 or else It.Typ = Universal_Real
4512 Get_Next_Interp (Index, It);
4517 end Is_Integer_Or_Universal;
4519 ----------------------------
4520 -- Set_Mixed_Mode_Operand --
4521 ----------------------------
4523 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4524 Index : Interp_Index;
4528 if Universal_Interpretation (N) = Universal_Integer then
4530 -- A universal integer literal is resolved as standard integer
4531 -- except in the case of a fixed-point result, where we leave it
4532 -- as universal (to be handled by Exp_Fixd later on)
4534 if Is_Fixed_Point_Type (T) then
4535 Resolve (N, Universal_Integer);
4537 Resolve (N, Standard_Integer);
4540 elsif Universal_Interpretation (N) = Universal_Real
4541 and then (T = Base_Type (Standard_Integer)
4542 or else T = Universal_Integer
4543 or else T = Universal_Real)
4545 -- A universal real can appear in a fixed-type context. We resolve
4546 -- the literal with that context, even though this might raise an
4547 -- exception prematurely (the other operand may be zero).
4551 elsif Etype (N) = Base_Type (Standard_Integer)
4552 and then T = Universal_Real
4553 and then Is_Overloaded (N)
4555 -- Integer arg in mixed-mode operation. Resolve with universal
4556 -- type, in case preference rule must be applied.
4558 Resolve (N, Universal_Integer);
4561 and then B_Typ /= Universal_Fixed
4563 -- Not a mixed-mode operation, resolve with context
4567 elsif Etype (N) = Any_Fixed then
4569 -- N may itself be a mixed-mode operation, so use context type
4573 elsif Is_Fixed_Point_Type (T)
4574 and then B_Typ = Universal_Fixed
4575 and then Is_Overloaded (N)
4577 -- Must be (fixed * fixed) operation, operand must have one
4578 -- compatible interpretation.
4580 Resolve (N, Any_Fixed);
4582 elsif Is_Fixed_Point_Type (B_Typ)
4583 and then (T = Universal_Real
4584 or else Is_Fixed_Point_Type (T))
4585 and then Is_Overloaded (N)
4587 -- C * F(X) in a fixed context, where C is a real literal or a
4588 -- fixed-point expression. F must have either a fixed type
4589 -- interpretation or an integer interpretation, but not both.
4591 Get_First_Interp (N, Index, It);
4592 while Present (It.Typ) loop
4593 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4594 if Analyzed (N) then
4595 Error_Msg_N ("ambiguous operand in fixed operation", N);
4597 Resolve (N, Standard_Integer);
4600 elsif Is_Fixed_Point_Type (It.Typ) then
4601 if Analyzed (N) then
4602 Error_Msg_N ("ambiguous operand in fixed operation", N);
4604 Resolve (N, It.Typ);
4608 Get_Next_Interp (Index, It);
4611 -- Reanalyze the literal with the fixed type of the context. If
4612 -- context is Universal_Fixed, we are within a conversion, leave
4613 -- the literal as a universal real because there is no usable
4614 -- fixed type, and the target of the conversion plays no role in
4628 if B_Typ = Universal_Fixed
4629 and then Nkind (Op2) = N_Real_Literal
4631 T2 := Universal_Real;
4636 Set_Analyzed (Op2, False);
4643 end Set_Mixed_Mode_Operand;
4645 ----------------------
4646 -- Set_Operand_Type --
4647 ----------------------
4649 procedure Set_Operand_Type (N : Node_Id) is
4651 if Etype (N) = Universal_Integer
4652 or else Etype (N) = Universal_Real
4656 end Set_Operand_Type;
4658 -- Start of processing for Resolve_Arithmetic_Op
4661 if Comes_From_Source (N)
4662 and then Ekind (Entity (N)) = E_Function
4663 and then Is_Imported (Entity (N))
4664 and then Is_Intrinsic_Subprogram (Entity (N))
4666 Resolve_Intrinsic_Operator (N, Typ);
4669 -- Special-case for mixed-mode universal expressions or fixed point type
4670 -- operation: each argument is resolved separately. The same treatment
4671 -- is required if one of the operands of a fixed point operation is
4672 -- universal real, since in this case we don't do a conversion to a
4673 -- specific fixed-point type (instead the expander handles the case).
4675 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4676 and then Present (Universal_Interpretation (L))
4677 and then Present (Universal_Interpretation (R))
4679 Resolve (L, Universal_Interpretation (L));
4680 Resolve (R, Universal_Interpretation (R));
4681 Set_Etype (N, B_Typ);
4683 elsif (B_Typ = Universal_Real
4684 or else Etype (N) = Universal_Fixed
4685 or else (Etype (N) = Any_Fixed
4686 and then Is_Fixed_Point_Type (B_Typ))
4687 or else (Is_Fixed_Point_Type (B_Typ)
4688 and then (Is_Integer_Or_Universal (L)
4690 Is_Integer_Or_Universal (R))))
4691 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4693 if TL = Universal_Integer or else TR = Universal_Integer then
4694 Check_For_Visible_Operator (N, B_Typ);
4697 -- If context is a fixed type and one operand is integer, the other
4698 -- is resolved with the type of the context.
4700 if Is_Fixed_Point_Type (B_Typ)
4701 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4702 or else TL = Universal_Integer)
4707 elsif Is_Fixed_Point_Type (B_Typ)
4708 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4709 or else TR = Universal_Integer)
4715 Set_Mixed_Mode_Operand (L, TR);
4716 Set_Mixed_Mode_Operand (R, TL);
4719 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4720 -- multiplying operators from being used when the expected type is
4721 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4722 -- some cases where the expected type is actually Any_Real;
4723 -- Expected_Type_Is_Any_Real takes care of that case.
4725 if Etype (N) = Universal_Fixed
4726 or else Etype (N) = Any_Fixed
4728 if B_Typ = Universal_Fixed
4729 and then not Expected_Type_Is_Any_Real (N)
4730 and then not Nkind_In (Parent (N), N_Type_Conversion,
4731 N_Unchecked_Type_Conversion)
4733 Error_Msg_N ("type cannot be determined from context!", N);
4734 Error_Msg_N ("\explicit conversion to result type required", N);
4736 Set_Etype (L, Any_Type);
4737 Set_Etype (R, Any_Type);
4740 if Ada_Version = Ada_83
4741 and then Etype (N) = Universal_Fixed
4743 Nkind_In (Parent (N), N_Type_Conversion,
4744 N_Unchecked_Type_Conversion)
4747 ("(Ada 83) fixed-point operation "
4748 & "needs explicit conversion", N);
4751 -- The expected type is "any real type" in contexts like
4753 -- type T is delta <universal_fixed-expression> ...
4755 -- in which case we need to set the type to Universal_Real
4756 -- so that static expression evaluation will work properly.
4758 if Expected_Type_Is_Any_Real (N) then
4759 Set_Etype (N, Universal_Real);
4761 Set_Etype (N, B_Typ);
4765 elsif Is_Fixed_Point_Type (B_Typ)
4766 and then (Is_Integer_Or_Universal (L)
4767 or else Nkind (L) = N_Real_Literal
4768 or else Nkind (R) = N_Real_Literal
4769 or else Is_Integer_Or_Universal (R))
4771 Set_Etype (N, B_Typ);
4773 elsif Etype (N) = Any_Fixed then
4775 -- If no previous errors, this is only possible if one operand is
4776 -- overloaded and the context is universal. Resolve as such.
4778 Set_Etype (N, B_Typ);
4782 if (TL = Universal_Integer or else TL = Universal_Real)
4784 (TR = Universal_Integer or else TR = Universal_Real)
4786 Check_For_Visible_Operator (N, B_Typ);
4789 -- If the context is Universal_Fixed and the operands are also
4790 -- universal fixed, this is an error, unless there is only one
4791 -- applicable fixed_point type (usually Duration).
4793 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4794 T := Unique_Fixed_Point_Type (N);
4796 if T = Any_Type then
4809 -- If one of the arguments was resolved to a non-universal type.
4810 -- label the result of the operation itself with the same type.
4811 -- Do the same for the universal argument, if any.
4813 T := Intersect_Types (L, R);
4814 Set_Etype (N, Base_Type (T));
4815 Set_Operand_Type (L);
4816 Set_Operand_Type (R);
4819 Generate_Operator_Reference (N, Typ);
4820 Eval_Arithmetic_Op (N);
4822 -- In SPARK, a multiplication or division with operands of fixed point
4823 -- types shall be qualified or explicitly converted to identify the
4826 if (Is_Fixed_Point_Type (Etype (L))
4827 or else Is_Fixed_Point_Type (Etype (R)))
4828 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4830 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
4832 Check_SPARK_Restriction
4833 ("operation should be qualified or explicitly converted", N);
4836 -- Set overflow and division checking bit. Much cleverer code needed
4837 -- here eventually and perhaps the Resolve routines should be separated
4838 -- for the various arithmetic operations, since they will need
4839 -- different processing. ???
4841 if Nkind (N) in N_Op then
4842 if not Overflow_Checks_Suppressed (Etype (N)) then
4843 Enable_Overflow_Check (N);
4846 -- Give warning if explicit division by zero
4848 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4849 and then not Division_Checks_Suppressed (Etype (N))
4851 Rop := Right_Opnd (N);
4853 if Compile_Time_Known_Value (Rop)
4854 and then ((Is_Integer_Type (Etype (Rop))
4855 and then Expr_Value (Rop) = Uint_0)
4857 (Is_Real_Type (Etype (Rop))
4858 and then Expr_Value_R (Rop) = Ureal_0))
4860 -- Specialize the warning message according to the operation
4864 Apply_Compile_Time_Constraint_Error
4865 (N, "division by zero?", CE_Divide_By_Zero,
4866 Loc => Sloc (Right_Opnd (N)));
4869 Apply_Compile_Time_Constraint_Error
4870 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4871 Loc => Sloc (Right_Opnd (N)));
4874 Apply_Compile_Time_Constraint_Error
4875 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4876 Loc => Sloc (Right_Opnd (N)));
4878 -- Division by zero can only happen with division, rem,
4879 -- and mod operations.
4882 raise Program_Error;
4885 -- Otherwise just set the flag to check at run time
4888 Activate_Division_Check (N);
4892 -- If Restriction No_Implicit_Conditionals is active, then it is
4893 -- violated if either operand can be negative for mod, or for rem
4894 -- if both operands can be negative.
4896 if Restriction_Check_Required (No_Implicit_Conditionals)
4897 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4906 -- Set if corresponding operand might be negative
4910 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4911 LNeg := (not OK) or else Lo < 0;
4914 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4915 RNeg := (not OK) or else Lo < 0;
4917 -- Check if we will be generating conditionals. There are two
4918 -- cases where that can happen, first for REM, the only case
4919 -- is largest negative integer mod -1, where the division can
4920 -- overflow, but we still have to give the right result. The
4921 -- front end generates a test for this annoying case. Here we
4922 -- just test if both operands can be negative (that's what the
4923 -- expander does, so we match its logic here).
4925 -- The second case is mod where either operand can be negative.
4926 -- In this case, the back end has to generate additional tests.
4928 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4930 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4932 Check_Restriction (No_Implicit_Conditionals, N);
4938 Check_Unset_Reference (L);
4939 Check_Unset_Reference (R);
4940 end Resolve_Arithmetic_Op;
4946 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4947 Loc : constant Source_Ptr := Sloc (N);
4948 Subp : constant Node_Id := Name (N);
4956 function Same_Or_Aliased_Subprograms
4958 E : Entity_Id) return Boolean;
4959 -- Returns True if the subprogram entity S is the same as E or else
4960 -- S is an alias of E.
4962 ---------------------------------
4963 -- Same_Or_Aliased_Subprograms --
4964 ---------------------------------
4966 function Same_Or_Aliased_Subprograms
4968 E : Entity_Id) return Boolean
4970 Subp_Alias : constant Entity_Id := Alias (S);
4973 or else (Present (Subp_Alias) and then Subp_Alias = E);
4974 end Same_Or_Aliased_Subprograms;
4976 -- Start of processing for Resolve_Call
4979 -- The context imposes a unique interpretation with type Typ on a
4980 -- procedure or function call. Find the entity of the subprogram that
4981 -- yields the expected type, and propagate the corresponding formal
4982 -- constraints on the actuals. The caller has established that an
4983 -- interpretation exists, and emitted an error if not unique.
4985 -- First deal with the case of a call to an access-to-subprogram,
4986 -- dereference made explicit in Analyze_Call.
4988 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4989 if not Is_Overloaded (Subp) then
4990 Nam := Etype (Subp);
4993 -- Find the interpretation whose type (a subprogram type) has a
4994 -- return type that is compatible with the context. Analysis of
4995 -- the node has established that one exists.
4999 Get_First_Interp (Subp, I, It);
5000 while Present (It.Typ) loop
5001 if Covers (Typ, Etype (It.Typ)) then
5006 Get_Next_Interp (I, It);
5010 raise Program_Error;
5014 -- If the prefix is not an entity, then resolve it
5016 if not Is_Entity_Name (Subp) then
5017 Resolve (Subp, Nam);
5020 -- For an indirect call, we always invalidate checks, since we do not
5021 -- know whether the subprogram is local or global. Yes we could do
5022 -- better here, e.g. by knowing that there are no local subprograms,
5023 -- but it does not seem worth the effort. Similarly, we kill all
5024 -- knowledge of current constant values.
5026 Kill_Current_Values;
5028 -- If this is a procedure call which is really an entry call, do
5029 -- the conversion of the procedure call to an entry call. Protected
5030 -- operations use the same circuitry because the name in the call
5031 -- can be an arbitrary expression with special resolution rules.
5033 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5034 or else (Is_Entity_Name (Subp)
5035 and then Ekind (Entity (Subp)) = E_Entry)
5037 Resolve_Entry_Call (N, Typ);
5038 Check_Elab_Call (N);
5040 -- Kill checks and constant values, as above for indirect case
5041 -- Who knows what happens when another task is activated?
5043 Kill_Current_Values;
5046 -- Normal subprogram call with name established in Resolve
5048 elsif not (Is_Type (Entity (Subp))) then
5049 Nam := Entity (Subp);
5050 Set_Entity_With_Style_Check (Subp, Nam);
5052 -- Otherwise we must have the case of an overloaded call
5055 pragma Assert (Is_Overloaded (Subp));
5057 -- Initialize Nam to prevent warning (we know it will be assigned
5058 -- in the loop below, but the compiler does not know that).
5062 Get_First_Interp (Subp, I, It);
5063 while Present (It.Typ) loop
5064 if Covers (Typ, It.Typ) then
5066 Set_Entity_With_Style_Check (Subp, Nam);
5070 Get_Next_Interp (I, It);
5074 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5075 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5076 and then Nkind (Subp) /= N_Explicit_Dereference
5077 and then Present (Parameter_Associations (N))
5079 -- The prefix is a parameterless function call that returns an access
5080 -- to subprogram. If parameters are present in the current call, add
5081 -- add an explicit dereference. We use the base type here because
5082 -- within an instance these may be subtypes.
5084 -- The dereference is added either in Analyze_Call or here. Should
5085 -- be consolidated ???
5087 Set_Is_Overloaded (Subp, False);
5088 Set_Etype (Subp, Etype (Nam));
5089 Insert_Explicit_Dereference (Subp);
5090 Nam := Designated_Type (Etype (Nam));
5091 Resolve (Subp, Nam);
5094 -- Check that a call to Current_Task does not occur in an entry body
5096 if Is_RTE (Nam, RE_Current_Task) then
5105 -- Exclude calls that occur within the default of a formal
5106 -- parameter of the entry, since those are evaluated outside
5109 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5111 if Nkind (P) = N_Entry_Body
5112 or else (Nkind (P) = N_Subprogram_Body
5113 and then Is_Entry_Barrier_Function (P))
5117 ("?& should not be used in entry body (RM C.7(17))",
5120 ("\Program_Error will be raised at run time?", N, Nam);
5122 Make_Raise_Program_Error (Loc,
5123 Reason => PE_Current_Task_In_Entry_Body));
5124 Set_Etype (N, Rtype);
5131 -- Check that a procedure call does not occur in the context of the
5132 -- entry call statement of a conditional or timed entry call. Note that
5133 -- the case of a call to a subprogram renaming of an entry will also be
5134 -- rejected. The test for N not being an N_Entry_Call_Statement is
5135 -- defensive, covering the possibility that the processing of entry
5136 -- calls might reach this point due to later modifications of the code
5139 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5140 and then Nkind (N) /= N_Entry_Call_Statement
5141 and then Entry_Call_Statement (Parent (N)) = N
5143 if Ada_Version < Ada_2005 then
5144 Error_Msg_N ("entry call required in select statement", N);
5146 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5147 -- for a procedure_or_entry_call, the procedure_name or
5148 -- procedure_prefix of the procedure_call_statement shall denote
5149 -- an entry renamed by a procedure, or (a view of) a primitive
5150 -- subprogram of a limited interface whose first parameter is
5151 -- a controlling parameter.
5153 elsif Nkind (N) = N_Procedure_Call_Statement
5154 and then not Is_Renamed_Entry (Nam)
5155 and then not Is_Controlling_Limited_Procedure (Nam)
5158 ("entry call or dispatching primitive of interface required", N);
5162 -- Check that this is not a call to a protected procedure or entry from
5163 -- within a protected function.
5165 if Ekind (Current_Scope) = E_Function
5166 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
5167 and then Ekind (Nam) /= E_Function
5168 and then Scope (Nam) = Scope (Current_Scope)
5170 Error_Msg_N ("within protected function, protected " &
5171 "object is constant", N);
5172 Error_Msg_N ("\cannot call operation that may modify it", N);
5175 -- Freeze the subprogram name if not in a spec-expression. Note that we
5176 -- freeze procedure calls as well as function calls. Procedure calls are
5177 -- not frozen according to the rules (RM 13.14(14)) because it is
5178 -- impossible to have a procedure call to a non-frozen procedure in pure
5179 -- Ada, but in the code that we generate in the expander, this rule
5180 -- needs extending because we can generate procedure calls that need
5183 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
5184 Freeze_Expression (Subp);
5187 -- For a predefined operator, the type of the result is the type imposed
5188 -- by context, except for a predefined operation on universal fixed.
5189 -- Otherwise The type of the call is the type returned by the subprogram
5192 if Is_Predefined_Op (Nam) then
5193 if Etype (N) /= Universal_Fixed then
5197 -- If the subprogram returns an array type, and the context requires the
5198 -- component type of that array type, the node is really an indexing of
5199 -- the parameterless call. Resolve as such. A pathological case occurs
5200 -- when the type of the component is an access to the array type. In
5201 -- this case the call is truly ambiguous.
5203 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5205 ((Is_Array_Type (Etype (Nam))
5206 and then Covers (Typ, Component_Type (Etype (Nam))))
5207 or else (Is_Access_Type (Etype (Nam))
5208 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5212 Component_Type (Designated_Type (Etype (Nam))))))
5215 Index_Node : Node_Id;
5217 Ret_Type : constant Entity_Id := Etype (Nam);
5220 if Is_Access_Type (Ret_Type)
5221 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5224 ("cannot disambiguate function call and indexing", N);
5226 New_Subp := Relocate_Node (Subp);
5227 Set_Entity (Subp, Nam);
5229 if (Is_Array_Type (Ret_Type)
5230 and then Component_Type (Ret_Type) /= Any_Type)
5232 (Is_Access_Type (Ret_Type)
5234 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5236 if Needs_No_Actuals (Nam) then
5238 -- Indexed call to a parameterless function
5241 Make_Indexed_Component (Loc,
5243 Make_Function_Call (Loc,
5245 Expressions => Parameter_Associations (N));
5247 -- An Ada 2005 prefixed call to a primitive operation
5248 -- whose first parameter is the prefix. This prefix was
5249 -- prepended to the parameter list, which is actually a
5250 -- list of indexes. Remove the prefix in order to build
5251 -- the proper indexed component.
5254 Make_Indexed_Component (Loc,
5256 Make_Function_Call (Loc,
5258 Parameter_Associations =>
5260 (Remove_Head (Parameter_Associations (N)))),
5261 Expressions => Parameter_Associations (N));
5264 -- Preserve the parenthesis count of the node
5266 Set_Paren_Count (Index_Node, Paren_Count (N));
5268 -- Since we are correcting a node classification error made
5269 -- by the parser, we call Replace rather than Rewrite.
5271 Replace (N, Index_Node);
5273 Set_Etype (Prefix (N), Ret_Type);
5275 Resolve_Indexed_Component (N, Typ);
5276 Check_Elab_Call (Prefix (N));
5284 Set_Etype (N, Etype (Nam));
5287 -- In the case where the call is to an overloaded subprogram, Analyze
5288 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5289 -- such a case Normalize_Actuals needs to be called once more to order
5290 -- the actuals correctly. Otherwise the call will have the ordering
5291 -- given by the last overloaded subprogram whether this is the correct
5292 -- one being called or not.
5294 if Is_Overloaded (Subp) then
5295 Normalize_Actuals (N, Nam, False, Norm_OK);
5296 pragma Assert (Norm_OK);
5299 -- In any case, call is fully resolved now. Reset Overload flag, to
5300 -- prevent subsequent overload resolution if node is analyzed again
5302 Set_Is_Overloaded (Subp, False);
5303 Set_Is_Overloaded (N, False);
5305 -- If we are calling the current subprogram from immediately within its
5306 -- body, then that is the case where we can sometimes detect cases of
5307 -- infinite recursion statically. Do not try this in case restriction
5308 -- No_Recursion is in effect anyway, and do it only for source calls.
5310 if Comes_From_Source (N) then
5311 Scop := Current_Scope;
5313 -- Issue warning for possible infinite recursion in the absence
5314 -- of the No_Recursion restriction.
5316 if Same_Or_Aliased_Subprograms (Nam, Scop)
5317 and then not Restriction_Active (No_Recursion)
5318 and then Check_Infinite_Recursion (N)
5320 -- Here we detected and flagged an infinite recursion, so we do
5321 -- not need to test the case below for further warnings. Also we
5322 -- are all done if we now have a raise SE node.
5324 if Nkind (N) = N_Raise_Storage_Error then
5328 -- If call is to immediately containing subprogram, then check for
5329 -- the case of a possible run-time detectable infinite recursion.
5332 Scope_Loop : while Scop /= Standard_Standard loop
5333 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5335 -- Although in general case, recursion is not statically
5336 -- checkable, the case of calling an immediately containing
5337 -- subprogram is easy to catch.
5339 Check_Restriction (No_Recursion, N);
5341 -- If the recursive call is to a parameterless subprogram,
5342 -- then even if we can't statically detect infinite
5343 -- recursion, this is pretty suspicious, and we output a
5344 -- warning. Furthermore, we will try later to detect some
5345 -- cases here at run time by expanding checking code (see
5346 -- Detect_Infinite_Recursion in package Exp_Ch6).
5348 -- If the recursive call is within a handler, do not emit a
5349 -- warning, because this is a common idiom: loop until input
5350 -- is correct, catch illegal input in handler and restart.
5352 if No (First_Formal (Nam))
5353 and then Etype (Nam) = Standard_Void_Type
5354 and then not Error_Posted (N)
5355 and then Nkind (Parent (N)) /= N_Exception_Handler
5357 -- For the case of a procedure call. We give the message
5358 -- only if the call is the first statement in a sequence
5359 -- of statements, or if all previous statements are
5360 -- simple assignments. This is simply a heuristic to
5361 -- decrease false positives, without losing too many good
5362 -- warnings. The idea is that these previous statements
5363 -- may affect global variables the procedure depends on.
5364 -- We also exclude raise statements, that may arise from
5365 -- constraint checks and are probably unrelated to the
5366 -- intended control flow.
5368 if Nkind (N) = N_Procedure_Call_Statement
5369 and then Is_List_Member (N)
5375 while Present (P) loop
5377 N_Assignment_Statement,
5378 N_Raise_Constraint_Error)
5388 -- Do not give warning if we are in a conditional context
5391 K : constant Node_Kind := Nkind (Parent (N));
5393 if (K = N_Loop_Statement
5394 and then Present (Iteration_Scheme (Parent (N))))
5395 or else K = N_If_Statement
5396 or else K = N_Elsif_Part
5397 or else K = N_Case_Statement_Alternative
5403 -- Here warning is to be issued
5405 Set_Has_Recursive_Call (Nam);
5407 ("?possible infinite recursion!", N);
5409 ("\?Storage_Error may be raised at run time!", N);
5415 Scop := Scope (Scop);
5416 end loop Scope_Loop;
5420 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5422 Check_Obsolescent_2005_Entity (Nam, Subp);
5424 -- If subprogram name is a predefined operator, it was given in
5425 -- functional notation. Replace call node with operator node, so
5426 -- that actuals can be resolved appropriately.
5428 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5429 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5432 elsif Present (Alias (Nam))
5433 and then Is_Predefined_Op (Alias (Nam))
5435 Resolve_Actuals (N, Nam);
5436 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5440 -- Create a transient scope if the resulting type requires it
5442 -- There are several notable exceptions:
5444 -- a) In init procs, the transient scope overhead is not needed, and is
5445 -- even incorrect when the call is a nested initialization call for a
5446 -- component whose expansion may generate adjust calls. However, if the
5447 -- call is some other procedure call within an initialization procedure
5448 -- (for example a call to Create_Task in the init_proc of the task
5449 -- run-time record) a transient scope must be created around this call.
5451 -- b) Enumeration literal pseudo-calls need no transient scope
5453 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5454 -- functions) do not use the secondary stack even though the return
5455 -- type may be unconstrained.
5457 -- d) Calls to a build-in-place function, since such functions may
5458 -- allocate their result directly in a target object, and cases where
5459 -- the result does get allocated in the secondary stack are checked for
5460 -- within the specialized Exp_Ch6 procedures for expanding those
5461 -- build-in-place calls.
5463 -- e) If the subprogram is marked Inline_Always, then even if it returns
5464 -- an unconstrained type the call does not require use of the secondary
5465 -- stack. However, inlining will only take place if the body to inline
5466 -- is already present. It may not be available if e.g. the subprogram is
5467 -- declared in a child instance.
5469 -- If this is an initialization call for a type whose construction
5470 -- uses the secondary stack, and it is not a nested call to initialize
5471 -- a component, we do need to create a transient scope for it. We
5472 -- check for this by traversing the type in Check_Initialization_Call.
5475 and then Has_Pragma_Inline_Always (Nam)
5476 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5477 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5481 elsif Ekind (Nam) = E_Enumeration_Literal
5482 or else Is_Build_In_Place_Function (Nam)
5483 or else Is_Intrinsic_Subprogram (Nam)
5487 elsif Expander_Active
5488 and then Is_Type (Etype (Nam))
5489 and then Requires_Transient_Scope (Etype (Nam))
5491 (not Within_Init_Proc
5493 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5495 Establish_Transient_Scope (N, Sec_Stack => True);
5497 -- If the call appears within the bounds of a loop, it will
5498 -- be rewritten and reanalyzed, nothing left to do here.
5500 if Nkind (N) /= N_Function_Call then
5504 elsif Is_Init_Proc (Nam)
5505 and then not Within_Init_Proc
5507 Check_Initialization_Call (N, Nam);
5510 -- A protected function cannot be called within the definition of the
5511 -- enclosing protected type.
5513 if Is_Protected_Type (Scope (Nam))
5514 and then In_Open_Scopes (Scope (Nam))
5515 and then not Has_Completion (Scope (Nam))
5518 ("& cannot be called before end of protected definition", N, Nam);
5521 -- Propagate interpretation to actuals, and add default expressions
5524 if Present (First_Formal (Nam)) then
5525 Resolve_Actuals (N, Nam);
5527 -- Overloaded literals are rewritten as function calls, for purpose of
5528 -- resolution. After resolution, we can replace the call with the
5531 elsif Ekind (Nam) = E_Enumeration_Literal then
5532 Copy_Node (Subp, N);
5533 Resolve_Entity_Name (N, Typ);
5535 -- Avoid validation, since it is a static function call
5537 Generate_Reference (Nam, Subp);
5541 -- If the subprogram is not global, then kill all saved values and
5542 -- checks. This is a bit conservative, since in many cases we could do
5543 -- better, but it is not worth the effort. Similarly, we kill constant
5544 -- values. However we do not need to do this for internal entities
5545 -- (unless they are inherited user-defined subprograms), since they
5546 -- are not in the business of molesting local values.
5548 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5549 -- kill all checks and values for calls to global subprograms. This
5550 -- takes care of the case where an access to a local subprogram is
5551 -- taken, and could be passed directly or indirectly and then called
5552 -- from almost any context.
5554 -- Note: we do not do this step till after resolving the actuals. That
5555 -- way we still take advantage of the current value information while
5556 -- scanning the actuals.
5558 -- We suppress killing values if we are processing the nodes associated
5559 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5560 -- type kills all the values as part of analyzing the code that
5561 -- initializes the dispatch tables.
5563 if Inside_Freezing_Actions = 0
5564 and then (not Is_Library_Level_Entity (Nam)
5565 or else Suppress_Value_Tracking_On_Call
5566 (Nearest_Dynamic_Scope (Current_Scope)))
5567 and then (Comes_From_Source (Nam)
5568 or else (Present (Alias (Nam))
5569 and then Comes_From_Source (Alias (Nam))))
5571 Kill_Current_Values;
5574 -- If we are warning about unread OUT parameters, this is the place to
5575 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5576 -- after the above call to Kill_Current_Values (since that call clears
5577 -- the Last_Assignment field of all local variables).
5579 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5580 and then Comes_From_Source (N)
5581 and then In_Extended_Main_Source_Unit (N)
5588 F := First_Formal (Nam);
5589 A := First_Actual (N);
5590 while Present (F) and then Present (A) loop
5591 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
5592 and then Warn_On_Modified_As_Out_Parameter (F)
5593 and then Is_Entity_Name (A)
5594 and then Present (Entity (A))
5595 and then Comes_From_Source (N)
5596 and then Safe_To_Capture_Value (N, Entity (A))
5598 Set_Last_Assignment (Entity (A), A);
5607 -- If the subprogram is a primitive operation, check whether or not
5608 -- it is a correct dispatching call.
5610 if Is_Overloadable (Nam)
5611 and then Is_Dispatching_Operation (Nam)
5613 Check_Dispatching_Call (N);
5615 elsif Ekind (Nam) /= E_Subprogram_Type
5616 and then Is_Abstract_Subprogram (Nam)
5617 and then not In_Instance
5619 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5622 -- If this is a dispatching call, generate the appropriate reference,
5623 -- for better source navigation in GPS.
5625 if Is_Overloadable (Nam)
5626 and then Present (Controlling_Argument (N))
5628 Generate_Reference (Nam, Subp, 'R');
5630 -- Normal case, not a dispatching call: generate a call reference
5633 Generate_Reference (Nam, Subp, 's');
5636 if Is_Intrinsic_Subprogram (Nam) then
5637 Check_Intrinsic_Call (N);
5640 -- Check for violation of restriction No_Specific_Termination_Handlers
5641 -- and warn on a potentially blocking call to Abort_Task.
5643 if Restriction_Check_Required (No_Specific_Termination_Handlers)
5644 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
5646 Is_RTE (Nam, RE_Specific_Handler))
5648 Check_Restriction (No_Specific_Termination_Handlers, N);
5650 elsif Is_RTE (Nam, RE_Abort_Task) then
5651 Check_Potentially_Blocking_Operation (N);
5654 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5655 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5656 -- need to check the second argument to determine whether it is an
5657 -- absolute or relative timing event.
5659 if Restriction_Check_Required (No_Relative_Delay)
5660 and then Is_RTE (Nam, RE_Set_Handler)
5661 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
5663 Check_Restriction (No_Relative_Delay, N);
5666 -- Issue an error for a call to an eliminated subprogram. We skip this
5667 -- in a spec expression, e.g. a call in a default parameter value, since
5668 -- we are not really doing a call at this time. That's important because
5669 -- the spec expression may itself belong to an eliminated subprogram.
5671 if not In_Spec_Expression then
5672 Check_For_Eliminated_Subprogram (Subp, Nam);
5675 -- In formal mode, the primitive operations of a tagged type or type
5676 -- extension do not include functions that return the tagged type.
5678 -- Commented out as the call to Is_Inherited_Operation_For_Type may
5679 -- cause an error because the type entity of the parent node of
5680 -- Entity (Name (N) may not be set. ???
5681 -- So why not just add a guard ???
5683 -- if Nkind (N) = N_Function_Call
5684 -- and then Is_Tagged_Type (Etype (N))
5685 -- and then Is_Entity_Name (Name (N))
5686 -- and then Is_Inherited_Operation_For_Type
5687 -- (Entity (Name (N)), Etype (N))
5689 -- Check_SPARK_Restriction ("function not inherited", N);
5692 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
5693 -- class-wide and the call dispatches on result in a context that does
5694 -- not provide a tag, the call raises Program_Error.
5696 if Nkind (N) = N_Function_Call
5697 and then In_Instance
5698 and then Is_Generic_Actual_Type (Typ)
5699 and then Is_Class_Wide_Type (Typ)
5700 and then Has_Controlling_Result (Nam)
5701 and then Nkind (Parent (N)) = N_Object_Declaration
5703 -- Verify that none of the formals are controlling
5706 Call_OK : Boolean := False;
5710 F := First_Formal (Nam);
5711 while Present (F) loop
5712 if Is_Controlling_Formal (F) then
5721 Error_Msg_N ("!? cannot determine tag of result", N);
5722 Error_Msg_N ("!? Program_Error will be raised", N);
5724 Make_Raise_Program_Error (Sloc (N),
5725 Reason => PE_Explicit_Raise));
5730 -- All done, evaluate call and deal with elaboration issues
5733 Check_Elab_Call (N);
5734 Warn_On_Overlapping_Actuals (Nam, N);
5737 -----------------------------
5738 -- Resolve_Case_Expression --
5739 -----------------------------
5741 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
5745 Alt := First (Alternatives (N));
5746 while Present (Alt) loop
5747 Resolve (Expression (Alt), Typ);
5752 Eval_Case_Expression (N);
5753 end Resolve_Case_Expression;
5755 -------------------------------
5756 -- Resolve_Character_Literal --
5757 -------------------------------
5759 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5760 B_Typ : constant Entity_Id := Base_Type (Typ);
5764 -- Verify that the character does belong to the type of the context
5766 Set_Etype (N, B_Typ);
5767 Eval_Character_Literal (N);
5769 -- Wide_Wide_Character literals must always be defined, since the set
5770 -- of wide wide character literals is complete, i.e. if a character
5771 -- literal is accepted by the parser, then it is OK for wide wide
5772 -- character (out of range character literals are rejected).
5774 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5777 -- Always accept character literal for type Any_Character, which
5778 -- occurs in error situations and in comparisons of literals, both
5779 -- of which should accept all literals.
5781 elsif B_Typ = Any_Character then
5784 -- For Standard.Character or a type derived from it, check that the
5785 -- literal is in range.
5787 elsif Root_Type (B_Typ) = Standard_Character then
5788 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5792 -- For Standard.Wide_Character or a type derived from it, check that the
5793 -- literal is in range.
5795 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5796 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5800 -- For Standard.Wide_Wide_Character or a type derived from it, we
5801 -- know the literal is in range, since the parser checked!
5803 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5806 -- If the entity is already set, this has already been resolved in a
5807 -- generic context, or comes from expansion. Nothing else to do.
5809 elsif Present (Entity (N)) then
5812 -- Otherwise we have a user defined character type, and we can use the
5813 -- standard visibility mechanisms to locate the referenced entity.
5816 C := Current_Entity (N);
5817 while Present (C) loop
5818 if Etype (C) = B_Typ then
5819 Set_Entity_With_Style_Check (N, C);
5820 Generate_Reference (C, N);
5828 -- If we fall through, then the literal does not match any of the
5829 -- entries of the enumeration type. This isn't just a constraint error
5830 -- situation, it is an illegality (see RM 4.2).
5833 ("character not defined for }", N, First_Subtype (B_Typ));
5834 end Resolve_Character_Literal;
5836 ---------------------------
5837 -- Resolve_Comparison_Op --
5838 ---------------------------
5840 -- Context requires a boolean type, and plays no role in resolution.
5841 -- Processing identical to that for equality operators. The result type is
5842 -- the base type, which matters when pathological subtypes of booleans with
5843 -- limited ranges are used.
5845 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5846 L : constant Node_Id := Left_Opnd (N);
5847 R : constant Node_Id := Right_Opnd (N);
5851 -- If this is an intrinsic operation which is not predefined, use the
5852 -- types of its declared arguments to resolve the possibly overloaded
5853 -- operands. Otherwise the operands are unambiguous and specify the
5856 if Scope (Entity (N)) /= Standard_Standard then
5857 T := Etype (First_Entity (Entity (N)));
5860 T := Find_Unique_Type (L, R);
5862 if T = Any_Fixed then
5863 T := Unique_Fixed_Point_Type (L);
5867 Set_Etype (N, Base_Type (Typ));
5868 Generate_Reference (T, N, ' ');
5870 -- Skip remaining processing if already set to Any_Type
5872 if T = Any_Type then
5876 -- Deal with other error cases
5878 if T = Any_String or else
5879 T = Any_Composite or else
5882 if T = Any_Character then
5883 Ambiguous_Character (L);
5885 Error_Msg_N ("ambiguous operands for comparison", N);
5888 Set_Etype (N, Any_Type);
5892 -- Resolve the operands if types OK
5896 Check_Unset_Reference (L);
5897 Check_Unset_Reference (R);
5898 Generate_Operator_Reference (N, T);
5899 Check_Low_Bound_Tested (N);
5901 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
5902 -- types or array types except String.
5904 if Is_Boolean_Type (T) then
5905 Check_SPARK_Restriction
5906 ("comparison is not defined on Boolean type", N);
5908 elsif Is_Array_Type (T)
5909 and then Base_Type (T) /= Standard_String
5911 Check_SPARK_Restriction
5912 ("comparison is not defined on array types other than String", N);
5915 -- Check comparison on unordered enumeration
5917 if Comes_From_Source (N)
5918 and then Bad_Unordered_Enumeration_Reference (N, Etype (L))
5920 Error_Msg_N ("comparison on unordered enumeration type?", N);
5923 -- Evaluate the relation (note we do this after the above check since
5924 -- this Eval call may change N to True/False.
5926 Eval_Relational_Op (N);
5927 end Resolve_Comparison_Op;
5929 ------------------------------------
5930 -- Resolve_Conditional_Expression --
5931 ------------------------------------
5933 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5934 Condition : constant Node_Id := First (Expressions (N));
5935 Then_Expr : constant Node_Id := Next (Condition);
5936 Else_Expr : Node_Id := Next (Then_Expr);
5939 Resolve (Condition, Any_Boolean);
5940 Resolve (Then_Expr, Typ);
5942 -- If ELSE expression present, just resolve using the determined type
5944 if Present (Else_Expr) then
5945 Resolve (Else_Expr, Typ);
5947 -- If no ELSE expression is present, root type must be Standard.Boolean
5948 -- and we provide a Standard.True result converted to the appropriate
5949 -- Boolean type (in case it is a derived boolean type).
5951 elsif Root_Type (Typ) = Standard_Boolean then
5953 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5954 Analyze_And_Resolve (Else_Expr, Typ);
5955 Append_To (Expressions (N), Else_Expr);
5958 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5959 Append_To (Expressions (N), Error);
5963 Eval_Conditional_Expression (N);
5964 end Resolve_Conditional_Expression;
5966 -----------------------------------------
5967 -- Resolve_Discrete_Subtype_Indication --
5968 -----------------------------------------
5970 procedure Resolve_Discrete_Subtype_Indication
5978 Analyze (Subtype_Mark (N));
5979 S := Entity (Subtype_Mark (N));
5981 if Nkind (Constraint (N)) /= N_Range_Constraint then
5982 Error_Msg_N ("expect range constraint for discrete type", N);
5983 Set_Etype (N, Any_Type);
5986 R := Range_Expression (Constraint (N));
5994 if Base_Type (S) /= Base_Type (Typ) then
5996 ("expect subtype of }", N, First_Subtype (Typ));
5998 -- Rewrite the constraint as a range of Typ
5999 -- to allow compilation to proceed further.
6002 Rewrite (Low_Bound (R),
6003 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6004 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6005 Attribute_Name => Name_First));
6006 Rewrite (High_Bound (R),
6007 Make_Attribute_Reference (Sloc (High_Bound (R)),
6008 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6009 Attribute_Name => Name_First));
6013 Set_Etype (N, Etype (R));
6015 -- Additionally, we must check that the bounds are compatible
6016 -- with the given subtype, which might be different from the
6017 -- type of the context.
6019 Apply_Range_Check (R, S);
6021 -- ??? If the above check statically detects a Constraint_Error
6022 -- it replaces the offending bound(s) of the range R with a
6023 -- Constraint_Error node. When the itype which uses these bounds
6024 -- is frozen the resulting call to Duplicate_Subexpr generates
6025 -- a new temporary for the bounds.
6027 -- Unfortunately there are other itypes that are also made depend
6028 -- on these bounds, so when Duplicate_Subexpr is called they get
6029 -- a forward reference to the newly created temporaries and Gigi
6030 -- aborts on such forward references. This is probably sign of a
6031 -- more fundamental problem somewhere else in either the order of
6032 -- itype freezing or the way certain itypes are constructed.
6034 -- To get around this problem we call Remove_Side_Effects right
6035 -- away if either bounds of R are a Constraint_Error.
6038 L : constant Node_Id := Low_Bound (R);
6039 H : constant Node_Id := High_Bound (R);
6042 if Nkind (L) = N_Raise_Constraint_Error then
6043 Remove_Side_Effects (L);
6046 if Nkind (H) = N_Raise_Constraint_Error then
6047 Remove_Side_Effects (H);
6051 Check_Unset_Reference (Low_Bound (R));
6052 Check_Unset_Reference (High_Bound (R));
6055 end Resolve_Discrete_Subtype_Indication;
6057 -------------------------
6058 -- Resolve_Entity_Name --
6059 -------------------------
6061 -- Used to resolve identifiers and expanded names
6063 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6064 E : constant Entity_Id := Entity (N);
6067 -- If garbage from errors, set to Any_Type and return
6069 if No (E) and then Total_Errors_Detected /= 0 then
6070 Set_Etype (N, Any_Type);
6074 -- Replace named numbers by corresponding literals. Note that this is
6075 -- the one case where Resolve_Entity_Name must reset the Etype, since
6076 -- it is currently marked as universal.
6078 if Ekind (E) = E_Named_Integer then
6080 Eval_Named_Integer (N);
6082 elsif Ekind (E) = E_Named_Real then
6084 Eval_Named_Real (N);
6086 -- For enumeration literals, we need to make sure that a proper style
6087 -- check is done, since such literals are overloaded, and thus we did
6088 -- not do a style check during the first phase of analysis.
6090 elsif Ekind (E) = E_Enumeration_Literal then
6091 Set_Entity_With_Style_Check (N, E);
6092 Eval_Entity_Name (N);
6094 -- Case of subtype name appearing as an operand in expression
6096 elsif Is_Type (E) then
6098 -- Allow use of subtype if it is a concurrent type where we are
6099 -- currently inside the body. This will eventually be expanded into a
6100 -- call to Self (for tasks) or _object (for protected objects). Any
6101 -- other use of a subtype is invalid.
6103 if Is_Concurrent_Type (E)
6104 and then In_Open_Scopes (E)
6108 -- Any other use is an error
6112 ("invalid use of subtype mark in expression or call", N);
6115 -- Check discriminant use if entity is discriminant in current scope,
6116 -- i.e. discriminant of record or concurrent type currently being
6117 -- analyzed. Uses in corresponding body are unrestricted.
6119 elsif Ekind (E) = E_Discriminant
6120 and then Scope (E) = Current_Scope
6121 and then not Has_Completion (Current_Scope)
6123 Check_Discriminant_Use (N);
6125 -- A parameterless generic function cannot appear in a context that
6126 -- requires resolution.
6128 elsif Ekind (E) = E_Generic_Function then
6129 Error_Msg_N ("illegal use of generic function", N);
6131 elsif Ekind (E) = E_Out_Parameter
6132 and then Ada_Version = Ada_83
6133 and then (Nkind (Parent (N)) in N_Op
6134 or else (Nkind (Parent (N)) = N_Assignment_Statement
6135 and then N = Expression (Parent (N)))
6136 or else Nkind (Parent (N)) = N_Explicit_Dereference)
6138 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6140 -- In all other cases, just do the possible static evaluation
6143 -- A deferred constant that appears in an expression must have a
6144 -- completion, unless it has been removed by in-place expansion of
6147 if Ekind (E) = E_Constant
6148 and then Comes_From_Source (E)
6149 and then No (Constant_Value (E))
6150 and then Is_Frozen (Etype (E))
6151 and then not In_Spec_Expression
6152 and then not Is_Imported (E)
6154 if No_Initialization (Parent (E))
6155 or else (Present (Full_View (E))
6156 and then No_Initialization (Parent (Full_View (E))))
6161 "deferred constant is frozen before completion", N);
6165 Eval_Entity_Name (N);
6167 end Resolve_Entity_Name;
6173 procedure Resolve_Entry (Entry_Name : Node_Id) is
6174 Loc : constant Source_Ptr := Sloc (Entry_Name);
6182 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6183 -- If the bounds of the entry family being called depend on task
6184 -- discriminants, build a new index subtype where a discriminant is
6185 -- replaced with the value of the discriminant of the target task.
6186 -- The target task is the prefix of the entry name in the call.
6188 -----------------------
6189 -- Actual_Index_Type --
6190 -----------------------
6192 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
6193 Typ : constant Entity_Id := Entry_Index_Type (E);
6194 Tsk : constant Entity_Id := Scope (E);
6195 Lo : constant Node_Id := Type_Low_Bound (Typ);
6196 Hi : constant Node_Id := Type_High_Bound (Typ);
6199 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6200 -- If the bound is given by a discriminant, replace with a reference
6201 -- to the discriminant of the same name in the target task. If the
6202 -- entry name is the target of a requeue statement and the entry is
6203 -- in the current protected object, the bound to be used is the
6204 -- discriminal of the object (see Apply_Range_Checks for details of
6205 -- the transformation).
6207 -----------------------------
6208 -- Actual_Discriminant_Ref --
6209 -----------------------------
6211 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
6212 Typ : constant Entity_Id := Etype (Bound);
6216 Remove_Side_Effects (Bound);
6218 if not Is_Entity_Name (Bound)
6219 or else Ekind (Entity (Bound)) /= E_Discriminant
6223 elsif Is_Protected_Type (Tsk)
6224 and then In_Open_Scopes (Tsk)
6225 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6227 -- Note: here Bound denotes a discriminant of the corresponding
6228 -- record type tskV, whose discriminal is a formal of the
6229 -- init-proc tskVIP. What we want is the body discriminal,
6230 -- which is associated to the discriminant of the original
6231 -- concurrent type tsk.
6233 return New_Occurrence_Of
6234 (Find_Body_Discriminal (Entity (Bound)), Loc);
6238 Make_Selected_Component (Loc,
6239 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6240 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6245 end Actual_Discriminant_Ref;
6247 -- Start of processing for Actual_Index_Type
6250 if not Has_Discriminants (Tsk)
6251 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
6253 return Entry_Index_Type (E);
6256 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6257 Set_Etype (New_T, Base_Type (Typ));
6258 Set_Size_Info (New_T, Typ);
6259 Set_RM_Size (New_T, RM_Size (Typ));
6260 Set_Scalar_Range (New_T,
6261 Make_Range (Sloc (Entry_Name),
6262 Low_Bound => Actual_Discriminant_Ref (Lo),
6263 High_Bound => Actual_Discriminant_Ref (Hi)));
6267 end Actual_Index_Type;
6269 -- Start of processing of Resolve_Entry
6272 -- Find name of entry being called, and resolve prefix of name with its
6273 -- own type. The prefix can be overloaded, and the name and signature of
6274 -- the entry must be taken into account.
6276 if Nkind (Entry_Name) = N_Indexed_Component then
6278 -- Case of dealing with entry family within the current tasks
6280 E_Name := Prefix (Entry_Name);
6283 E_Name := Entry_Name;
6286 if Is_Entity_Name (E_Name) then
6288 -- Entry call to an entry (or entry family) in the current task. This
6289 -- is legal even though the task will deadlock. Rewrite as call to
6292 -- This can also be a call to an entry in an enclosing task. If this
6293 -- is a single task, we have to retrieve its name, because the scope
6294 -- of the entry is the task type, not the object. If the enclosing
6295 -- task is a task type, the identity of the task is given by its own
6298 -- Finally this can be a requeue on an entry of the same task or
6299 -- protected object.
6301 S := Scope (Entity (E_Name));
6303 for J in reverse 0 .. Scope_Stack.Last loop
6304 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6305 and then not Comes_From_Source (S)
6307 -- S is an enclosing task or protected object. The concurrent
6308 -- declaration has been converted into a type declaration, and
6309 -- the object itself has an object declaration that follows
6310 -- the type in the same declarative part.
6312 Tsk := Next_Entity (S);
6313 while Etype (Tsk) /= S loop
6320 elsif S = Scope_Stack.Table (J).Entity then
6322 -- Call to current task. Will be transformed into call to Self
6330 Make_Selected_Component (Loc,
6331 Prefix => New_Occurrence_Of (S, Loc),
6333 New_Occurrence_Of (Entity (E_Name), Loc));
6334 Rewrite (E_Name, New_N);
6337 elsif Nkind (Entry_Name) = N_Selected_Component
6338 and then Is_Overloaded (Prefix (Entry_Name))
6340 -- Use the entry name (which must be unique at this point) to find
6341 -- the prefix that returns the corresponding task/protected type.
6344 Pref : constant Node_Id := Prefix (Entry_Name);
6345 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
6350 Get_First_Interp (Pref, I, It);
6351 while Present (It.Typ) loop
6352 if Scope (Ent) = It.Typ then
6353 Set_Etype (Pref, It.Typ);
6357 Get_Next_Interp (I, It);
6362 if Nkind (Entry_Name) = N_Selected_Component then
6363 Resolve (Prefix (Entry_Name));
6365 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6366 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6367 Resolve (Prefix (Prefix (Entry_Name)));
6368 Index := First (Expressions (Entry_Name));
6369 Resolve (Index, Entry_Index_Type (Nam));
6371 -- Up to this point the expression could have been the actual in a
6372 -- simple entry call, and be given by a named association.
6374 if Nkind (Index) = N_Parameter_Association then
6375 Error_Msg_N ("expect expression for entry index", Index);
6377 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6382 ------------------------
6383 -- Resolve_Entry_Call --
6384 ------------------------
6386 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6387 Entry_Name : constant Node_Id := Name (N);
6388 Loc : constant Source_Ptr := Sloc (Entry_Name);
6390 First_Named : Node_Id;
6397 -- We kill all checks here, because it does not seem worth the effort to
6398 -- do anything better, an entry call is a big operation.
6402 -- Processing of the name is similar for entry calls and protected
6403 -- operation calls. Once the entity is determined, we can complete
6404 -- the resolution of the actuals.
6406 -- The selector may be overloaded, in the case of a protected object
6407 -- with overloaded functions. The type of the context is used for
6410 if Nkind (Entry_Name) = N_Selected_Component
6411 and then Is_Overloaded (Selector_Name (Entry_Name))
6412 and then Typ /= Standard_Void_Type
6419 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6420 while Present (It.Typ) loop
6421 if Covers (Typ, It.Typ) then
6422 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6423 Set_Etype (Entry_Name, It.Typ);
6425 Generate_Reference (It.Typ, N, ' ');
6428 Get_Next_Interp (I, It);
6433 Resolve_Entry (Entry_Name);
6435 if Nkind (Entry_Name) = N_Selected_Component then
6437 -- Simple entry call
6439 Nam := Entity (Selector_Name (Entry_Name));
6440 Obj := Prefix (Entry_Name);
6441 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6443 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6445 -- Call to member of entry family
6447 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6448 Obj := Prefix (Prefix (Entry_Name));
6449 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6452 -- We cannot in general check the maximum depth of protected entry calls
6453 -- at compile time. But we can tell that any protected entry call at all
6454 -- violates a specified nesting depth of zero.
6456 if Is_Protected_Type (Scope (Nam)) then
6457 Check_Restriction (Max_Entry_Queue_Length, N);
6460 -- Use context type to disambiguate a protected function that can be
6461 -- called without actuals and that returns an array type, and where the
6462 -- argument list may be an indexing of the returned value.
6464 if Ekind (Nam) = E_Function
6465 and then Needs_No_Actuals (Nam)
6466 and then Present (Parameter_Associations (N))
6468 ((Is_Array_Type (Etype (Nam))
6469 and then Covers (Typ, Component_Type (Etype (Nam))))
6471 or else (Is_Access_Type (Etype (Nam))
6472 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6476 Component_Type (Designated_Type (Etype (Nam))))))
6479 Index_Node : Node_Id;
6483 Make_Indexed_Component (Loc,
6485 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
6486 Expressions => Parameter_Associations (N));
6488 -- Since we are correcting a node classification error made by the
6489 -- parser, we call Replace rather than Rewrite.
6491 Replace (N, Index_Node);
6492 Set_Etype (Prefix (N), Etype (Nam));
6494 Resolve_Indexed_Component (N, Typ);
6499 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6500 and then Present (PPC_Wrapper (Nam))
6501 and then Current_Scope /= PPC_Wrapper (Nam)
6503 -- Rewrite as call to the precondition wrapper, adding the task
6504 -- object to the list of actuals. If the call is to a member of an
6505 -- entry family, include the index as well.
6509 New_Actuals : List_Id;
6512 New_Actuals := New_List (Obj);
6514 if Nkind (Entry_Name) = N_Indexed_Component then
6515 Append_To (New_Actuals,
6516 New_Copy_Tree (First (Expressions (Entry_Name))));
6519 Append_List (Parameter_Associations (N), New_Actuals);
6521 Make_Procedure_Call_Statement (Loc,
6523 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6524 Parameter_Associations => New_Actuals);
6525 Rewrite (N, New_Call);
6526 Analyze_And_Resolve (N);
6531 -- The operation name may have been overloaded. Order the actuals
6532 -- according to the formals of the resolved entity, and set the return
6533 -- type to that of the operation.
6536 Normalize_Actuals (N, Nam, False, Norm_OK);
6537 pragma Assert (Norm_OK);
6538 Set_Etype (N, Etype (Nam));
6541 Resolve_Actuals (N, Nam);
6543 -- Create a call reference to the entry
6545 Generate_Reference (Nam, Entry_Name, 's');
6547 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
6548 Check_Potentially_Blocking_Operation (N);
6551 -- Verify that a procedure call cannot masquerade as an entry
6552 -- call where an entry call is expected.
6554 if Ekind (Nam) = E_Procedure then
6555 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6556 and then N = Entry_Call_Statement (Parent (N))
6558 Error_Msg_N ("entry call required in select statement", N);
6560 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6561 and then N = Triggering_Statement (Parent (N))
6563 Error_Msg_N ("triggering statement cannot be procedure call", N);
6565 elsif Ekind (Scope (Nam)) = E_Task_Type
6566 and then not In_Open_Scopes (Scope (Nam))
6568 Error_Msg_N ("task has no entry with this name", Entry_Name);
6572 -- After resolution, entry calls and protected procedure calls are
6573 -- changed into entry calls, for expansion. The structure of the node
6574 -- does not change, so it can safely be done in place. Protected
6575 -- function calls must keep their structure because they are
6578 if Ekind (Nam) /= E_Function then
6580 -- A protected operation that is not a function may modify the
6581 -- corresponding object, and cannot apply to a constant. If this
6582 -- is an internal call, the prefix is the type itself.
6584 if Is_Protected_Type (Scope (Nam))
6585 and then not Is_Variable (Obj)
6586 and then (not Is_Entity_Name (Obj)
6587 or else not Is_Type (Entity (Obj)))
6590 ("prefix of protected procedure or entry call must be variable",
6594 Actuals := Parameter_Associations (N);
6595 First_Named := First_Named_Actual (N);
6598 Make_Entry_Call_Statement (Loc,
6600 Parameter_Associations => Actuals));
6602 Set_First_Named_Actual (N, First_Named);
6603 Set_Analyzed (N, True);
6605 -- Protected functions can return on the secondary stack, in which
6606 -- case we must trigger the transient scope mechanism.
6608 elsif Expander_Active
6609 and then Requires_Transient_Scope (Etype (Nam))
6611 Establish_Transient_Scope (N, Sec_Stack => True);
6613 end Resolve_Entry_Call;
6615 -------------------------
6616 -- Resolve_Equality_Op --
6617 -------------------------
6619 -- Both arguments must have the same type, and the boolean context does
6620 -- not participate in the resolution. The first pass verifies that the
6621 -- interpretation is not ambiguous, and the type of the left argument is
6622 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6623 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6624 -- though they carry a single (universal) type. Diagnose this case here.
6626 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6627 L : constant Node_Id := Left_Opnd (N);
6628 R : constant Node_Id := Right_Opnd (N);
6629 T : Entity_Id := Find_Unique_Type (L, R);
6631 procedure Check_Conditional_Expression (Cond : Node_Id);
6632 -- The resolution rule for conditional expressions requires that each
6633 -- such must have a unique type. This means that if several dependent
6634 -- expressions are of a non-null anonymous access type, and the context
6635 -- does not impose an expected type (as can be the case in an equality
6636 -- operation) the expression must be rejected.
6638 function Find_Unique_Access_Type return Entity_Id;
6639 -- In the case of allocators, make a last-ditch attempt to find a single
6640 -- access type with the right designated type. This is semantically
6641 -- dubious, and of no interest to any real code, but c48008a makes it
6644 ----------------------------------
6645 -- Check_Conditional_Expression --
6646 ----------------------------------
6648 procedure Check_Conditional_Expression (Cond : Node_Id) is
6649 Then_Expr : Node_Id;
6650 Else_Expr : Node_Id;
6653 if Nkind (Cond) = N_Conditional_Expression then
6654 Then_Expr := Next (First (Expressions (Cond)));
6655 Else_Expr := Next (Then_Expr);
6657 if Nkind (Then_Expr) /= N_Null
6658 and then Nkind (Else_Expr) /= N_Null
6661 ("cannot determine type of conditional expression", Cond);
6664 end Check_Conditional_Expression;
6666 -----------------------------
6667 -- Find_Unique_Access_Type --
6668 -----------------------------
6670 function Find_Unique_Access_Type return Entity_Id is
6676 if Ekind (Etype (R)) = E_Allocator_Type then
6677 Acc := Designated_Type (Etype (R));
6678 elsif Ekind (Etype (L)) = E_Allocator_Type then
6679 Acc := Designated_Type (Etype (L));
6685 while S /= Standard_Standard loop
6686 E := First_Entity (S);
6687 while Present (E) loop
6689 and then Is_Access_Type (E)
6690 and then Ekind (E) /= E_Allocator_Type
6691 and then Designated_Type (E) = Base_Type (Acc)
6703 end Find_Unique_Access_Type;
6705 -- Start of processing for Resolve_Equality_Op
6708 Set_Etype (N, Base_Type (Typ));
6709 Generate_Reference (T, N, ' ');
6711 if T = Any_Fixed then
6712 T := Unique_Fixed_Point_Type (L);
6715 if T /= Any_Type then
6716 if T = Any_String or else
6717 T = Any_Composite or else
6720 if T = Any_Character then
6721 Ambiguous_Character (L);
6723 Error_Msg_N ("ambiguous operands for equality", N);
6726 Set_Etype (N, Any_Type);
6729 elsif T = Any_Access
6730 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
6732 T := Find_Unique_Access_Type;
6735 Error_Msg_N ("ambiguous operands for equality", N);
6736 Set_Etype (N, Any_Type);
6740 -- Conditional expressions must have a single type, and if the
6741 -- context does not impose one the dependent expressions cannot
6742 -- be anonymous access types.
6744 elsif Ada_Version >= Ada_2012
6745 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
6746 E_Anonymous_Access_Subprogram_Type)
6747 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
6748 E_Anonymous_Access_Subprogram_Type)
6750 Check_Conditional_Expression (L);
6751 Check_Conditional_Expression (R);
6757 -- In SPARK, equality operators = and /= for array types other than
6758 -- String are only defined when, for each index position, the
6759 -- operands have equal static bounds.
6761 if Is_Array_Type (T) then
6762 -- Protect call to Matching_Static_Array_Bounds to avoid costly
6763 -- operation if not needed.
6765 if Restriction_Check_Required (SPARK)
6766 and then Base_Type (T) /= Standard_String
6767 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6768 and then Etype (L) /= Any_Composite -- or else L in error
6769 and then Etype (R) /= Any_Composite -- or else R in error
6770 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
6772 Check_SPARK_Restriction
6773 ("array types should have matching static bounds", N);
6777 -- If the unique type is a class-wide type then it will be expanded
6778 -- into a dispatching call to the predefined primitive. Therefore we
6779 -- check here for potential violation of such restriction.
6781 if Is_Class_Wide_Type (T) then
6782 Check_Restriction (No_Dispatching_Calls, N);
6785 if Warn_On_Redundant_Constructs
6786 and then Comes_From_Source (N)
6787 and then Is_Entity_Name (R)
6788 and then Entity (R) = Standard_True
6789 and then Comes_From_Source (R)
6791 Error_Msg_N -- CODEFIX
6792 ("?comparison with True is redundant!", R);
6795 Check_Unset_Reference (L);
6796 Check_Unset_Reference (R);
6797 Generate_Operator_Reference (N, T);
6798 Check_Low_Bound_Tested (N);
6800 -- If this is an inequality, it may be the implicit inequality
6801 -- created for a user-defined operation, in which case the corres-
6802 -- ponding equality operation is not intrinsic, and the operation
6803 -- cannot be constant-folded. Else fold.
6805 if Nkind (N) = N_Op_Eq
6806 or else Comes_From_Source (Entity (N))
6807 or else Ekind (Entity (N)) = E_Operator
6808 or else Is_Intrinsic_Subprogram
6809 (Corresponding_Equality (Entity (N)))
6811 Eval_Relational_Op (N);
6813 elsif Nkind (N) = N_Op_Ne
6814 and then Is_Abstract_Subprogram (Entity (N))
6816 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6819 -- Ada 2005: If one operand is an anonymous access type, convert the
6820 -- other operand to it, to ensure that the underlying types match in
6821 -- the back-end. Same for access_to_subprogram, and the conversion
6822 -- verifies that the types are subtype conformant.
6824 -- We apply the same conversion in the case one of the operands is a
6825 -- private subtype of the type of the other.
6827 -- Why the Expander_Active test here ???
6831 (Ekind_In (T, E_Anonymous_Access_Type,
6832 E_Anonymous_Access_Subprogram_Type)
6833 or else Is_Private_Type (T))
6835 if Etype (L) /= T then
6837 Make_Unchecked_Type_Conversion (Sloc (L),
6838 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6839 Expression => Relocate_Node (L)));
6840 Analyze_And_Resolve (L, T);
6843 if (Etype (R)) /= T then
6845 Make_Unchecked_Type_Conversion (Sloc (R),
6846 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6847 Expression => Relocate_Node (R)));
6848 Analyze_And_Resolve (R, T);
6852 end Resolve_Equality_Op;
6854 ----------------------------------
6855 -- Resolve_Explicit_Dereference --
6856 ----------------------------------
6858 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6859 Loc : constant Source_Ptr := Sloc (N);
6861 P : constant Node_Id := Prefix (N);
6866 Check_Fully_Declared_Prefix (Typ, P);
6868 if Is_Overloaded (P) then
6870 -- Use the context type to select the prefix that has the correct
6873 Get_First_Interp (P, I, It);
6874 while Present (It.Typ) loop
6875 exit when Is_Access_Type (It.Typ)
6876 and then Covers (Typ, Designated_Type (It.Typ));
6877 Get_Next_Interp (I, It);
6880 if Present (It.Typ) then
6881 Resolve (P, It.Typ);
6883 -- If no interpretation covers the designated type of the prefix,
6884 -- this is the pathological case where not all implementations of
6885 -- the prefix allow the interpretation of the node as a call. Now
6886 -- that the expected type is known, Remove other interpretations
6887 -- from prefix, rewrite it as a call, and resolve again, so that
6888 -- the proper call node is generated.
6890 Get_First_Interp (P, I, It);
6891 while Present (It.Typ) loop
6892 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6896 Get_Next_Interp (I, It);
6900 Make_Function_Call (Loc,
6902 Make_Explicit_Dereference (Loc,
6904 Parameter_Associations => New_List);
6906 Save_Interps (N, New_N);
6908 Analyze_And_Resolve (N, Typ);
6912 Set_Etype (N, Designated_Type (It.Typ));
6918 if Is_Access_Type (Etype (P)) then
6919 Apply_Access_Check (N);
6922 -- If the designated type is a packed unconstrained array type, and the
6923 -- explicit dereference is not in the context of an attribute reference,
6924 -- then we must compute and set the actual subtype, since it is needed
6925 -- by Gigi. The reason we exclude the attribute case is that this is
6926 -- handled fine by Gigi, and in fact we use such attributes to build the
6927 -- actual subtype. We also exclude generated code (which builds actual
6928 -- subtypes directly if they are needed).
6930 if Is_Array_Type (Etype (N))
6931 and then Is_Packed (Etype (N))
6932 and then not Is_Constrained (Etype (N))
6933 and then Nkind (Parent (N)) /= N_Attribute_Reference
6934 and then Comes_From_Source (N)
6936 Set_Etype (N, Get_Actual_Subtype (N));
6939 -- Note: No Eval processing is required for an explicit dereference,
6940 -- because such a name can never be static.
6942 end Resolve_Explicit_Dereference;
6944 -------------------------------------
6945 -- Resolve_Expression_With_Actions --
6946 -------------------------------------
6948 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
6951 end Resolve_Expression_With_Actions;
6953 -------------------------------
6954 -- Resolve_Indexed_Component --
6955 -------------------------------
6957 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6958 Name : constant Node_Id := Prefix (N);
6960 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6964 if Is_Overloaded (Name) then
6966 -- Use the context type to select the prefix that yields the correct
6972 I1 : Interp_Index := 0;
6973 P : constant Node_Id := Prefix (N);
6974 Found : Boolean := False;
6977 Get_First_Interp (P, I, It);
6978 while Present (It.Typ) loop
6979 if (Is_Array_Type (It.Typ)
6980 and then Covers (Typ, Component_Type (It.Typ)))
6981 or else (Is_Access_Type (It.Typ)
6982 and then Is_Array_Type (Designated_Type (It.Typ))
6986 Component_Type (Designated_Type (It.Typ))))
6989 It := Disambiguate (P, I1, I, Any_Type);
6991 if It = No_Interp then
6992 Error_Msg_N ("ambiguous prefix for indexing", N);
6998 Array_Type := It.Typ;
7004 Array_Type := It.Typ;
7009 Get_Next_Interp (I, It);
7014 Array_Type := Etype (Name);
7017 Resolve (Name, Array_Type);
7018 Array_Type := Get_Actual_Subtype_If_Available (Name);
7020 -- If prefix is access type, dereference to get real array type.
7021 -- Note: we do not apply an access check because the expander always
7022 -- introduces an explicit dereference, and the check will happen there.
7024 if Is_Access_Type (Array_Type) then
7025 Array_Type := Designated_Type (Array_Type);
7028 -- If name was overloaded, set component type correctly now
7029 -- If a misplaced call to an entry family (which has no index types)
7030 -- return. Error will be diagnosed from calling context.
7032 if Is_Array_Type (Array_Type) then
7033 Set_Etype (N, Component_Type (Array_Type));
7038 Index := First_Index (Array_Type);
7039 Expr := First (Expressions (N));
7041 -- The prefix may have resolved to a string literal, in which case its
7042 -- etype has a special representation. This is only possible currently
7043 -- if the prefix is a static concatenation, written in functional
7046 if Ekind (Array_Type) = E_String_Literal_Subtype then
7047 Resolve (Expr, Standard_Positive);
7050 while Present (Index) and Present (Expr) loop
7051 Resolve (Expr, Etype (Index));
7052 Check_Unset_Reference (Expr);
7054 if Is_Scalar_Type (Etype (Expr)) then
7055 Apply_Scalar_Range_Check (Expr, Etype (Index));
7057 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
7065 -- Do not generate the warning on suspicious index if we are analyzing
7066 -- package Ada.Tags; otherwise we will report the warning with the
7067 -- Prims_Ptr field of the dispatch table.
7069 if Scope (Etype (Prefix (N))) = Standard_Standard
7071 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
7074 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
7075 Eval_Indexed_Component (N);
7078 -- If the array type is atomic, and is packed, and we are in a left side
7079 -- context, then this is worth a warning, since we have a situation
7080 -- where the access to the component may cause extra read/writes of
7081 -- the atomic array object, which could be considered unexpected.
7083 if Nkind (N) = N_Indexed_Component
7084 and then (Is_Atomic (Array_Type)
7085 or else (Is_Entity_Name (Prefix (N))
7086 and then Is_Atomic (Entity (Prefix (N)))))
7087 and then Is_Bit_Packed_Array (Array_Type)
7090 Error_Msg_N ("?assignment to component of packed atomic array",
7092 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
7095 end Resolve_Indexed_Component;
7097 -----------------------------
7098 -- Resolve_Integer_Literal --
7099 -----------------------------
7101 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7104 Eval_Integer_Literal (N);
7105 end Resolve_Integer_Literal;
7107 --------------------------------
7108 -- Resolve_Intrinsic_Operator --
7109 --------------------------------
7111 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
7112 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7114 Orig_Op : constant Entity_Id := Entity (N);
7118 function Convert_Operand (Opnd : Node_Id) return Node_Id;
7119 -- If the operand is a literal, it cannot be the expression in a
7120 -- conversion. Use a qualified expression instead.
7122 function Convert_Operand (Opnd : Node_Id) return Node_Id is
7123 Loc : constant Source_Ptr := Sloc (Opnd);
7126 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
7128 Make_Qualified_Expression (Loc,
7129 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7130 Expression => Relocate_Node (Opnd));
7134 Res := Unchecked_Convert_To (Btyp, Opnd);
7138 end Convert_Operand;
7141 -- We must preserve the original entity in a generic setting, so that
7142 -- the legality of the operation can be verified in an instance.
7144 if not Expander_Active then
7149 while Scope (Op) /= Standard_Standard loop
7151 pragma Assert (Present (Op));
7155 Set_Is_Overloaded (N, False);
7157 -- If the operand type is private, rewrite with suitable conversions on
7158 -- the operands and the result, to expose the proper underlying numeric
7161 if Is_Private_Type (Typ) then
7162 Arg1 := Convert_Operand (Left_Opnd (N));
7163 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
7165 if Nkind (N) = N_Op_Expon then
7166 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7168 Arg2 := Convert_Operand (Right_Opnd (N));
7171 if Nkind (Arg1) = N_Type_Conversion then
7172 Save_Interps (Left_Opnd (N), Expression (Arg1));
7175 if Nkind (Arg2) = N_Type_Conversion then
7176 Save_Interps (Right_Opnd (N), Expression (Arg2));
7179 Set_Left_Opnd (N, Arg1);
7180 Set_Right_Opnd (N, Arg2);
7182 Set_Etype (N, Btyp);
7183 Rewrite (N, Unchecked_Convert_To (Typ, N));
7186 elsif Typ /= Etype (Left_Opnd (N))
7187 or else Typ /= Etype (Right_Opnd (N))
7189 -- Add explicit conversion where needed, and save interpretations in
7190 -- case operands are overloaded. If the context is a VMS operation,
7191 -- assert that the conversion is legal (the operands have the proper
7192 -- types to select the VMS intrinsic). Note that in rare cases the
7193 -- VMS operators may be visible, but the default System is being used
7194 -- and Address is a private type.
7196 Arg1 := Convert_To (Typ, Left_Opnd (N));
7197 Arg2 := Convert_To (Typ, Right_Opnd (N));
7199 if Nkind (Arg1) = N_Type_Conversion then
7200 Save_Interps (Left_Opnd (N), Expression (Arg1));
7202 if Is_VMS_Operator (Orig_Op) then
7203 Set_Conversion_OK (Arg1);
7206 Save_Interps (Left_Opnd (N), Arg1);
7209 if Nkind (Arg2) = N_Type_Conversion then
7210 Save_Interps (Right_Opnd (N), Expression (Arg2));
7212 if Is_VMS_Operator (Orig_Op) then
7213 Set_Conversion_OK (Arg2);
7216 Save_Interps (Right_Opnd (N), Arg2);
7219 Rewrite (Left_Opnd (N), Arg1);
7220 Rewrite (Right_Opnd (N), Arg2);
7223 Resolve_Arithmetic_Op (N, Typ);
7226 Resolve_Arithmetic_Op (N, Typ);
7228 end Resolve_Intrinsic_Operator;
7230 --------------------------------------
7231 -- Resolve_Intrinsic_Unary_Operator --
7232 --------------------------------------
7234 procedure Resolve_Intrinsic_Unary_Operator
7238 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7244 while Scope (Op) /= Standard_Standard loop
7246 pragma Assert (Present (Op));
7251 if Is_Private_Type (Typ) then
7252 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7253 Save_Interps (Right_Opnd (N), Expression (Arg2));
7255 Set_Right_Opnd (N, Arg2);
7257 Set_Etype (N, Btyp);
7258 Rewrite (N, Unchecked_Convert_To (Typ, N));
7262 Resolve_Unary_Op (N, Typ);
7264 end Resolve_Intrinsic_Unary_Operator;
7266 ------------------------
7267 -- Resolve_Logical_Op --
7268 ------------------------
7270 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7274 Check_No_Direct_Boolean_Operators (N);
7276 -- Predefined operations on scalar types yield the base type. On the
7277 -- other hand, logical operations on arrays yield the type of the
7278 -- arguments (and the context).
7280 if Is_Array_Type (Typ) then
7283 B_Typ := Base_Type (Typ);
7286 -- OK if this is a VMS-specific intrinsic operation
7288 if Is_VMS_Operator (Entity (N)) then
7291 -- The following test is required because the operands of the operation
7292 -- may be literals, in which case the resulting type appears to be
7293 -- compatible with a signed integer type, when in fact it is compatible
7294 -- only with modular types. If the context itself is universal, the
7295 -- operation is illegal.
7297 elsif not Valid_Boolean_Arg (Typ) then
7298 Error_Msg_N ("invalid context for logical operation", N);
7299 Set_Etype (N, Any_Type);
7302 elsif Typ = Any_Modular then
7304 ("no modular type available in this context", N);
7305 Set_Etype (N, Any_Type);
7308 elsif Is_Modular_Integer_Type (Typ)
7309 and then Etype (Left_Opnd (N)) = Universal_Integer
7310 and then Etype (Right_Opnd (N)) = Universal_Integer
7312 Check_For_Visible_Operator (N, B_Typ);
7315 Resolve (Left_Opnd (N), B_Typ);
7316 Resolve (Right_Opnd (N), B_Typ);
7318 Check_Unset_Reference (Left_Opnd (N));
7319 Check_Unset_Reference (Right_Opnd (N));
7321 Set_Etype (N, B_Typ);
7322 Generate_Operator_Reference (N, B_Typ);
7323 Eval_Logical_Op (N);
7325 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
7326 -- only when both operands have same static lower and higher bounds. Of
7327 -- course the types have to match, so only check if operands are
7328 -- compatible and the node itself has no errors.
7330 if Is_Array_Type (B_Typ)
7331 and then Nkind (N) in N_Binary_Op
7334 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
7335 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
7338 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7339 -- operation if not needed.
7341 if Restriction_Check_Required (SPARK)
7342 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
7343 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
7344 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
7345 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
7347 Check_SPARK_Restriction
7348 ("array types should have matching static bounds", N);
7352 end Resolve_Logical_Op;
7354 ---------------------------
7355 -- Resolve_Membership_Op --
7356 ---------------------------
7358 -- The context can only be a boolean type, and does not determine the
7359 -- arguments. Arguments should be unambiguous, but the preference rule for
7360 -- universal types applies.
7362 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
7363 pragma Warnings (Off, Typ);
7365 L : constant Node_Id := Left_Opnd (N);
7366 R : constant Node_Id := Right_Opnd (N);
7369 procedure Resolve_Set_Membership;
7370 -- Analysis has determined a unique type for the left operand. Use it to
7371 -- resolve the disjuncts.
7373 ----------------------------
7374 -- Resolve_Set_Membership --
7375 ----------------------------
7377 procedure Resolve_Set_Membership is
7381 Resolve (L, Etype (L));
7383 Alt := First (Alternatives (N));
7384 while Present (Alt) loop
7386 -- Alternative is an expression, a range
7387 -- or a subtype mark.
7389 if not Is_Entity_Name (Alt)
7390 or else not Is_Type (Entity (Alt))
7392 Resolve (Alt, Etype (L));
7397 end Resolve_Set_Membership;
7399 -- Start of processing for Resolve_Membership_Op
7402 if L = Error or else R = Error then
7406 if Present (Alternatives (N)) then
7407 Resolve_Set_Membership;
7410 elsif not Is_Overloaded (R)
7412 (Etype (R) = Universal_Integer
7414 Etype (R) = Universal_Real)
7415 and then Is_Overloaded (L)
7419 -- Ada 2005 (AI-251): Support the following case:
7421 -- type I is interface;
7422 -- type T is tagged ...
7424 -- function Test (O : I'Class) is
7426 -- return O in T'Class.
7429 -- In this case we have nothing else to do. The membership test will be
7430 -- done at run time.
7432 elsif Ada_Version >= Ada_2005
7433 and then Is_Class_Wide_Type (Etype (L))
7434 and then Is_Interface (Etype (L))
7435 and then Is_Class_Wide_Type (Etype (R))
7436 and then not Is_Interface (Etype (R))
7440 T := Intersect_Types (L, R);
7443 -- If mixed-mode operations are present and operands are all literal,
7444 -- the only interpretation involves Duration, which is probably not
7445 -- the intention of the programmer.
7447 if T = Any_Fixed then
7448 T := Unique_Fixed_Point_Type (N);
7450 if T = Any_Type then
7456 Check_Unset_Reference (L);
7458 if Nkind (R) = N_Range
7459 and then not Is_Scalar_Type (T)
7461 Error_Msg_N ("scalar type required for range", R);
7464 if Is_Entity_Name (R) then
7465 Freeze_Expression (R);
7468 Check_Unset_Reference (R);
7471 Eval_Membership_Op (N);
7472 end Resolve_Membership_Op;
7478 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
7479 Loc : constant Source_Ptr := Sloc (N);
7482 -- Handle restriction against anonymous null access values This
7483 -- restriction can be turned off using -gnatdj.
7485 -- Ada 2005 (AI-231): Remove restriction
7487 if Ada_Version < Ada_2005
7488 and then not Debug_Flag_J
7489 and then Ekind (Typ) = E_Anonymous_Access_Type
7490 and then Comes_From_Source (N)
7492 -- In the common case of a call which uses an explicitly null value
7493 -- for an access parameter, give specialized error message.
7495 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
7499 ("null is not allowed as argument for an access parameter", N);
7501 -- Standard message for all other cases (are there any?)
7505 ("null cannot be of an anonymous access type", N);
7509 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7510 -- assignment to a null-excluding object
7512 if Ada_Version >= Ada_2005
7513 and then Can_Never_Be_Null (Typ)
7514 and then Nkind (Parent (N)) = N_Assignment_Statement
7516 if not Inside_Init_Proc then
7518 (Compile_Time_Constraint_Error (N,
7519 "(Ada 2005) null not allowed in null-excluding objects?"),
7520 Make_Raise_Constraint_Error (Loc,
7521 Reason => CE_Access_Check_Failed));
7524 Make_Raise_Constraint_Error (Loc,
7525 Reason => CE_Access_Check_Failed));
7529 -- In a distributed context, null for a remote access to subprogram may
7530 -- need to be replaced with a special record aggregate. In this case,
7531 -- return after having done the transformation.
7533 if (Ekind (Typ) = E_Record_Type
7534 or else Is_Remote_Access_To_Subprogram_Type (Typ))
7535 and then Remote_AST_Null_Value (N, Typ)
7540 -- The null literal takes its type from the context
7545 -----------------------
7546 -- Resolve_Op_Concat --
7547 -----------------------
7549 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
7551 -- We wish to avoid deep recursion, because concatenations are often
7552 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
7553 -- operands nonrecursively until we find something that is not a simple
7554 -- concatenation (A in this case). We resolve that, and then walk back
7555 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
7556 -- to do the rest of the work at each level. The Parent pointers allow
7557 -- us to avoid recursion, and thus avoid running out of memory. See also
7558 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
7564 -- The following code is equivalent to:
7566 -- Resolve_Op_Concat_First (NN, Typ);
7567 -- Resolve_Op_Concat_Arg (N, ...);
7568 -- Resolve_Op_Concat_Rest (N, Typ);
7570 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
7571 -- operand is a concatenation.
7573 -- Walk down left operands
7576 Resolve_Op_Concat_First (NN, Typ);
7577 Op1 := Left_Opnd (NN);
7578 exit when not (Nkind (Op1) = N_Op_Concat
7579 and then not Is_Array_Type (Component_Type (Typ))
7580 and then Entity (Op1) = Entity (NN));
7584 -- Now (given the above example) NN is A&B and Op1 is A
7586 -- First resolve Op1 ...
7588 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7590 -- ... then walk NN back up until we reach N (where we started), calling
7591 -- Resolve_Op_Concat_Rest along the way.
7594 Resolve_Op_Concat_Rest (NN, Typ);
7599 if Base_Type (Etype (N)) /= Standard_String then
7600 Check_SPARK_Restriction
7601 ("result of concatenation should have type String", N);
7603 end Resolve_Op_Concat;
7605 ---------------------------
7606 -- Resolve_Op_Concat_Arg --
7607 ---------------------------
7609 procedure Resolve_Op_Concat_Arg
7615 Btyp : constant Entity_Id := Base_Type (Typ);
7616 Ctyp : constant Entity_Id := Component_Type (Typ);
7621 or else (not Is_Overloaded (Arg)
7622 and then Etype (Arg) /= Any_Composite
7623 and then Covers (Ctyp, Etype (Arg)))
7625 Resolve (Arg, Ctyp);
7627 Resolve (Arg, Btyp);
7630 -- If both Array & Array and Array & Component are visible, there is a
7631 -- potential ambiguity that must be reported.
7633 elsif Has_Compatible_Type (Arg, Ctyp) then
7634 if Nkind (Arg) = N_Aggregate
7635 and then Is_Composite_Type (Ctyp)
7637 if Is_Private_Type (Ctyp) then
7638 Resolve (Arg, Btyp);
7640 -- If the operation is user-defined and not overloaded use its
7641 -- profile. The operation may be a renaming, in which case it has
7642 -- been rewritten, and we want the original profile.
7644 elsif not Is_Overloaded (N)
7645 and then Comes_From_Source (Entity (Original_Node (N)))
7646 and then Ekind (Entity (Original_Node (N))) = E_Function
7650 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
7653 -- Otherwise an aggregate may match both the array type and the
7657 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7658 Set_Etype (Arg, Any_Type);
7662 if Is_Overloaded (Arg)
7663 and then Has_Compatible_Type (Arg, Typ)
7664 and then Etype (Arg) /= Any_Type
7672 Get_First_Interp (Arg, I, It);
7674 Get_Next_Interp (I, It);
7676 -- Special-case the error message when the overloading is
7677 -- caused by a function that yields an array and can be
7678 -- called without parameters.
7680 if It.Nam = Func then
7681 Error_Msg_Sloc := Sloc (Func);
7682 Error_Msg_N ("ambiguous call to function#", Arg);
7684 ("\\interpretation as call yields&", Arg, Typ);
7686 ("\\interpretation as indexing of call yields&",
7687 Arg, Component_Type (Typ));
7690 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
7692 Get_First_Interp (Arg, I, It);
7693 while Present (It.Nam) loop
7694 Error_Msg_Sloc := Sloc (It.Nam);
7696 if Base_Type (It.Typ) = Btyp
7698 Base_Type (It.Typ) = Base_Type (Ctyp)
7700 Error_Msg_N -- CODEFIX
7701 ("\\possible interpretation#", Arg);
7704 Get_Next_Interp (I, It);
7710 Resolve (Arg, Component_Type (Typ));
7712 if Nkind (Arg) = N_String_Literal then
7713 Set_Etype (Arg, Component_Type (Typ));
7716 if Arg = Left_Opnd (N) then
7717 Set_Is_Component_Left_Opnd (N);
7719 Set_Is_Component_Right_Opnd (N);
7724 Resolve (Arg, Btyp);
7727 -- Concatenation is restricted in SPARK: each operand must be either a
7728 -- string literal, the name of a string constant, a static character or
7729 -- string expression, or another concatenation. Arg cannot be a
7730 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
7731 -- separately on each final operand, past concatenation operations.
7733 if Is_Character_Type (Etype (Arg)) then
7734 if not Is_Static_Expression (Arg) then
7735 Check_SPARK_Restriction
7736 ("character operand for concatenation should be static", N);
7739 elsif Is_String_Type (Etype (Arg)) then
7740 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
7741 and then Is_Constant_Object (Entity (Arg)))
7742 and then not Is_Static_Expression (Arg)
7744 Check_SPARK_Restriction
7745 ("string operand for concatenation should be static", N);
7748 -- Do not issue error on an operand that is neither a character nor a
7749 -- string, as the error is issued in Resolve_Op_Concat.
7755 Check_Unset_Reference (Arg);
7756 end Resolve_Op_Concat_Arg;
7758 -----------------------------
7759 -- Resolve_Op_Concat_First --
7760 -----------------------------
7762 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7763 Btyp : constant Entity_Id := Base_Type (Typ);
7764 Op1 : constant Node_Id := Left_Opnd (N);
7765 Op2 : constant Node_Id := Right_Opnd (N);
7768 -- The parser folds an enormous sequence of concatenations of string
7769 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7770 -- in the right operand. If the expression resolves to a predefined "&"
7771 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7772 -- we give an error. See P_Simple_Expression in Par.Ch4.
7774 if Nkind (Op2) = N_String_Literal
7775 and then Is_Folded_In_Parser (Op2)
7776 and then Ekind (Entity (N)) = E_Function
7778 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7779 and then String_Length (Strval (Op1)) = 0);
7780 Error_Msg_N ("too many user-defined concatenations", N);
7784 Set_Etype (N, Btyp);
7786 if Is_Limited_Composite (Btyp) then
7787 Error_Msg_N ("concatenation not available for limited array", N);
7788 Explain_Limited_Type (Btyp, N);
7790 end Resolve_Op_Concat_First;
7792 ----------------------------
7793 -- Resolve_Op_Concat_Rest --
7794 ----------------------------
7796 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7797 Op1 : constant Node_Id := Left_Opnd (N);
7798 Op2 : constant Node_Id := Right_Opnd (N);
7801 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7803 Generate_Operator_Reference (N, Typ);
7805 if Is_String_Type (Typ) then
7806 Eval_Concatenation (N);
7809 -- If this is not a static concatenation, but the result is a string
7810 -- type (and not an array of strings) ensure that static string operands
7811 -- have their subtypes properly constructed.
7813 if Nkind (N) /= N_String_Literal
7814 and then Is_Character_Type (Component_Type (Typ))
7816 Set_String_Literal_Subtype (Op1, Typ);
7817 Set_String_Literal_Subtype (Op2, Typ);
7819 end Resolve_Op_Concat_Rest;
7821 ----------------------
7822 -- Resolve_Op_Expon --
7823 ----------------------
7825 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7826 B_Typ : constant Entity_Id := Base_Type (Typ);
7829 -- Catch attempts to do fixed-point exponentiation with universal
7830 -- operands, which is a case where the illegality is not caught during
7831 -- normal operator analysis.
7833 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7834 Error_Msg_N ("exponentiation not available for fixed point", N);
7837 elsif Nkind (Parent (N)) in N_Op
7838 and then Is_Fixed_Point_Type (Etype (Parent (N)))
7839 and then Etype (N) = Universal_Real
7840 and then Comes_From_Source (N)
7842 Error_Msg_N ("exponentiation not available for fixed point", N);
7846 if Comes_From_Source (N)
7847 and then Ekind (Entity (N)) = E_Function
7848 and then Is_Imported (Entity (N))
7849 and then Is_Intrinsic_Subprogram (Entity (N))
7851 Resolve_Intrinsic_Operator (N, Typ);
7855 if Etype (Left_Opnd (N)) = Universal_Integer
7856 or else Etype (Left_Opnd (N)) = Universal_Real
7858 Check_For_Visible_Operator (N, B_Typ);
7861 -- We do the resolution using the base type, because intermediate values
7862 -- in expressions always are of the base type, not a subtype of it.
7864 Resolve (Left_Opnd (N), B_Typ);
7865 Resolve (Right_Opnd (N), Standard_Integer);
7867 Check_Unset_Reference (Left_Opnd (N));
7868 Check_Unset_Reference (Right_Opnd (N));
7870 Set_Etype (N, B_Typ);
7871 Generate_Operator_Reference (N, B_Typ);
7874 -- Set overflow checking bit. Much cleverer code needed here eventually
7875 -- and perhaps the Resolve routines should be separated for the various
7876 -- arithmetic operations, since they will need different processing. ???
7878 if Nkind (N) in N_Op then
7879 if not Overflow_Checks_Suppressed (Etype (N)) then
7880 Enable_Overflow_Check (N);
7883 end Resolve_Op_Expon;
7885 --------------------
7886 -- Resolve_Op_Not --
7887 --------------------
7889 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7892 function Parent_Is_Boolean return Boolean;
7893 -- This function determines if the parent node is a boolean operator or
7894 -- operation (comparison op, membership test, or short circuit form) and
7895 -- the not in question is the left operand of this operation. Note that
7896 -- if the not is in parens, then false is returned.
7898 -----------------------
7899 -- Parent_Is_Boolean --
7900 -----------------------
7902 function Parent_Is_Boolean return Boolean is
7904 if Paren_Count (N) /= 0 then
7908 case Nkind (Parent (N)) is
7923 return Left_Opnd (Parent (N)) = N;
7929 end Parent_Is_Boolean;
7931 -- Start of processing for Resolve_Op_Not
7934 -- Predefined operations on scalar types yield the base type. On the
7935 -- other hand, logical operations on arrays yield the type of the
7936 -- arguments (and the context).
7938 if Is_Array_Type (Typ) then
7941 B_Typ := Base_Type (Typ);
7944 if Is_VMS_Operator (Entity (N)) then
7947 -- Straightforward case of incorrect arguments
7949 elsif not Valid_Boolean_Arg (Typ) then
7950 Error_Msg_N ("invalid operand type for operator&", N);
7951 Set_Etype (N, Any_Type);
7954 -- Special case of probable missing parens
7956 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7957 if Parent_Is_Boolean then
7959 ("operand of not must be enclosed in parentheses",
7963 ("no modular type available in this context", N);
7966 Set_Etype (N, Any_Type);
7969 -- OK resolution of NOT
7972 -- Warn if non-boolean types involved. This is a case like not a < b
7973 -- where a and b are modular, where we will get (not a) < b and most
7974 -- likely not (a < b) was intended.
7976 if Warn_On_Questionable_Missing_Parens
7977 and then not Is_Boolean_Type (Typ)
7978 and then Parent_Is_Boolean
7980 Error_Msg_N ("?not expression should be parenthesized here!", N);
7983 -- Warn on double negation if checking redundant constructs
7985 if Warn_On_Redundant_Constructs
7986 and then Comes_From_Source (N)
7987 and then Comes_From_Source (Right_Opnd (N))
7988 and then Root_Type (Typ) = Standard_Boolean
7989 and then Nkind (Right_Opnd (N)) = N_Op_Not
7991 Error_Msg_N ("redundant double negation?", N);
7994 -- Complete resolution and evaluation of NOT
7996 Resolve (Right_Opnd (N), B_Typ);
7997 Check_Unset_Reference (Right_Opnd (N));
7998 Set_Etype (N, B_Typ);
7999 Generate_Operator_Reference (N, B_Typ);
8004 -----------------------------
8005 -- Resolve_Operator_Symbol --
8006 -----------------------------
8008 -- Nothing to be done, all resolved already
8010 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
8011 pragma Warnings (Off, N);
8012 pragma Warnings (Off, Typ);
8016 end Resolve_Operator_Symbol;
8018 ----------------------------------
8019 -- Resolve_Qualified_Expression --
8020 ----------------------------------
8022 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
8023 pragma Warnings (Off, Typ);
8025 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
8026 Expr : constant Node_Id := Expression (N);
8029 Resolve (Expr, Target_Typ);
8031 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8032 -- operation if not needed.
8034 if Restriction_Check_Required (SPARK)
8035 and then Is_Array_Type (Target_Typ)
8036 and then Is_Array_Type (Etype (Expr))
8037 and then Etype (Expr) /= Any_Composite -- or else Expr in error
8038 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
8040 Check_SPARK_Restriction
8041 ("array types should have matching static bounds", N);
8044 -- A qualified expression requires an exact match of the type, class-
8045 -- wide matching is not allowed. However, if the qualifying type is
8046 -- specific and the expression has a class-wide type, it may still be
8047 -- okay, since it can be the result of the expansion of a call to a
8048 -- dispatching function, so we also have to check class-wideness of the
8049 -- type of the expression's original node.
8051 if (Is_Class_Wide_Type (Target_Typ)
8053 (Is_Class_Wide_Type (Etype (Expr))
8054 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
8055 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
8057 Wrong_Type (Expr, Target_Typ);
8060 -- If the target type is unconstrained, then we reset the type of the
8061 -- result from the type of the expression. For other cases, the actual
8062 -- subtype of the expression is the target type.
8064 if Is_Composite_Type (Target_Typ)
8065 and then not Is_Constrained (Target_Typ)
8067 Set_Etype (N, Etype (Expr));
8070 Eval_Qualified_Expression (N);
8071 end Resolve_Qualified_Expression;
8073 -----------------------------------
8074 -- Resolve_Quantified_Expression --
8075 -----------------------------------
8077 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id) is
8079 if not ALFA_Mode then
8081 -- The loop structure is already resolved during its analysis, only
8082 -- the resolution of the condition needs to be done. Expansion is
8083 -- disabled so that checks and other generated code are inserted in
8084 -- the tree after expression has been rewritten as a loop.
8086 Expander_Mode_Save_And_Set (False);
8087 Resolve (Condition (N), Typ);
8088 Expander_Mode_Restore;
8091 -- In ALFA_Mode, no such magic needs to happen, we just resolve the
8092 -- underlying nodes.
8094 Resolve (Condition (N), Typ);
8096 end Resolve_Quantified_Expression;
8102 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
8103 L : constant Node_Id := Low_Bound (N);
8104 H : constant Node_Id := High_Bound (N);
8106 function First_Last_Ref return Boolean;
8107 -- Returns True if N is of the form X'First .. X'Last where X is the
8108 -- same entity for both attributes.
8110 --------------------
8111 -- First_Last_Ref --
8112 --------------------
8114 function First_Last_Ref return Boolean is
8115 Lorig : constant Node_Id := Original_Node (L);
8116 Horig : constant Node_Id := Original_Node (H);
8119 if Nkind (Lorig) = N_Attribute_Reference
8120 and then Nkind (Horig) = N_Attribute_Reference
8121 and then Attribute_Name (Lorig) = Name_First
8122 and then Attribute_Name (Horig) = Name_Last
8125 PL : constant Node_Id := Prefix (Lorig);
8126 PH : constant Node_Id := Prefix (Horig);
8128 if Is_Entity_Name (PL)
8129 and then Is_Entity_Name (PH)
8130 and then Entity (PL) = Entity (PH)
8140 -- Start of processing for Resolve_Range
8147 -- Check for inappropriate range on unordered enumeration type
8149 if Bad_Unordered_Enumeration_Reference (N, Typ)
8151 -- Exclude X'First .. X'Last if X is the same entity for both
8153 and then not First_Last_Ref
8155 Error_Msg ("subrange of unordered enumeration type?", Sloc (N));
8158 Check_Unset_Reference (L);
8159 Check_Unset_Reference (H);
8161 -- We have to check the bounds for being within the base range as
8162 -- required for a non-static context. Normally this is automatic and
8163 -- done as part of evaluating expressions, but the N_Range node is an
8164 -- exception, since in GNAT we consider this node to be a subexpression,
8165 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8166 -- this, but that would put the test on the main evaluation path for
8169 Check_Non_Static_Context (L);
8170 Check_Non_Static_Context (H);
8172 -- Check for an ambiguous range over character literals. This will
8173 -- happen with a membership test involving only literals.
8175 if Typ = Any_Character then
8176 Ambiguous_Character (L);
8177 Set_Etype (N, Any_Type);
8181 -- If bounds are static, constant-fold them, so size computations are
8182 -- identical between front-end and back-end. Do not perform this
8183 -- transformation while analyzing generic units, as type information
8184 -- would be lost when reanalyzing the constant node in the instance.
8186 if Is_Discrete_Type (Typ) and then Expander_Active then
8187 if Is_OK_Static_Expression (L) then
8188 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8191 if Is_OK_Static_Expression (H) then
8192 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8197 --------------------------
8198 -- Resolve_Real_Literal --
8199 --------------------------
8201 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8202 Actual_Typ : constant Entity_Id := Etype (N);
8205 -- Special processing for fixed-point literals to make sure that the
8206 -- value is an exact multiple of small where this is required. We skip
8207 -- this for the universal real case, and also for generic types.
8209 if Is_Fixed_Point_Type (Typ)
8210 and then Typ /= Universal_Fixed
8211 and then Typ /= Any_Fixed
8212 and then not Is_Generic_Type (Typ)
8215 Val : constant Ureal := Realval (N);
8216 Cintr : constant Ureal := Val / Small_Value (Typ);
8217 Cint : constant Uint := UR_Trunc (Cintr);
8218 Den : constant Uint := Norm_Den (Cintr);
8222 -- Case of literal is not an exact multiple of the Small
8226 -- For a source program literal for a decimal fixed-point type,
8227 -- this is statically illegal (RM 4.9(36)).
8229 if Is_Decimal_Fixed_Point_Type (Typ)
8230 and then Actual_Typ = Universal_Real
8231 and then Comes_From_Source (N)
8233 Error_Msg_N ("value has extraneous low order digits", N);
8236 -- Generate a warning if literal from source
8238 if Is_Static_Expression (N)
8239 and then Warn_On_Bad_Fixed_Value
8242 ("?static fixed-point value is not a multiple of Small!",
8246 -- Replace literal by a value that is the exact representation
8247 -- of a value of the type, i.e. a multiple of the small value,
8248 -- by truncation, since Machine_Rounds is false for all GNAT
8249 -- fixed-point types (RM 4.9(38)).
8251 Stat := Is_Static_Expression (N);
8253 Make_Real_Literal (Sloc (N),
8254 Realval => Small_Value (Typ) * Cint));
8256 Set_Is_Static_Expression (N, Stat);
8259 -- In all cases, set the corresponding integer field
8261 Set_Corresponding_Integer_Value (N, Cint);
8265 -- Now replace the actual type by the expected type as usual
8268 Eval_Real_Literal (N);
8269 end Resolve_Real_Literal;
8271 -----------------------
8272 -- Resolve_Reference --
8273 -----------------------
8275 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
8276 P : constant Node_Id := Prefix (N);
8279 -- Replace general access with specific type
8281 if Ekind (Etype (N)) = E_Allocator_Type then
8282 Set_Etype (N, Base_Type (Typ));
8285 Resolve (P, Designated_Type (Etype (N)));
8287 -- If we are taking the reference of a volatile entity, then treat it as
8288 -- a potential modification of this entity. This is too conservative,
8289 -- but necessary because remove side effects can cause transformations
8290 -- of normal assignments into reference sequences that otherwise fail to
8291 -- notice the modification.
8293 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
8294 Note_Possible_Modification (P, Sure => False);
8296 end Resolve_Reference;
8298 --------------------------------
8299 -- Resolve_Selected_Component --
8300 --------------------------------
8302 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
8304 Comp1 : Entity_Id := Empty; -- prevent junk warning
8305 P : constant Node_Id := Prefix (N);
8306 S : constant Node_Id := Selector_Name (N);
8307 T : Entity_Id := Etype (P);
8309 I1 : Interp_Index := 0; -- prevent junk warning
8314 function Init_Component return Boolean;
8315 -- Check whether this is the initialization of a component within an
8316 -- init proc (by assignment or call to another init proc). If true,
8317 -- there is no need for a discriminant check.
8319 --------------------
8320 -- Init_Component --
8321 --------------------
8323 function Init_Component return Boolean is
8325 return Inside_Init_Proc
8326 and then Nkind (Prefix (N)) = N_Identifier
8327 and then Chars (Prefix (N)) = Name_uInit
8328 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
8331 -- Start of processing for Resolve_Selected_Component
8334 if Is_Overloaded (P) then
8336 -- Use the context type to select the prefix that has a selector
8337 -- of the correct name and type.
8340 Get_First_Interp (P, I, It);
8342 Search : while Present (It.Typ) loop
8343 if Is_Access_Type (It.Typ) then
8344 T := Designated_Type (It.Typ);
8349 -- Locate selected component. For a private prefix the selector
8350 -- can denote a discriminant.
8352 if Is_Record_Type (T) or else Is_Private_Type (T) then
8354 -- The visible components of a class-wide type are those of
8357 if Is_Class_Wide_Type (T) then
8361 Comp := First_Entity (T);
8362 while Present (Comp) loop
8363 if Chars (Comp) = Chars (S)
8364 and then Covers (Etype (Comp), Typ)
8373 It := Disambiguate (P, I1, I, Any_Type);
8375 if It = No_Interp then
8377 ("ambiguous prefix for selected component", N);
8384 -- There may be an implicit dereference. Retrieve
8385 -- designated record type.
8387 if Is_Access_Type (It1.Typ) then
8388 T := Designated_Type (It1.Typ);
8393 if Scope (Comp1) /= T then
8395 -- Resolution chooses the new interpretation.
8396 -- Find the component with the right name.
8398 Comp1 := First_Entity (T);
8399 while Present (Comp1)
8400 and then Chars (Comp1) /= Chars (S)
8402 Comp1 := Next_Entity (Comp1);
8411 Comp := Next_Entity (Comp);
8415 Get_Next_Interp (I, It);
8418 Resolve (P, It1.Typ);
8420 Set_Entity_With_Style_Check (S, Comp1);
8423 -- Resolve prefix with its type
8428 -- Generate cross-reference. We needed to wait until full overloading
8429 -- resolution was complete to do this, since otherwise we can't tell if
8430 -- we are an lvalue or not.
8432 if May_Be_Lvalue (N) then
8433 Generate_Reference (Entity (S), S, 'm');
8435 Generate_Reference (Entity (S), S, 'r');
8438 -- If prefix is an access type, the node will be transformed into an
8439 -- explicit dereference during expansion. The type of the node is the
8440 -- designated type of that of the prefix.
8442 if Is_Access_Type (Etype (P)) then
8443 T := Designated_Type (Etype (P));
8444 Check_Fully_Declared_Prefix (T, P);
8449 if Has_Discriminants (T)
8450 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
8451 and then Present (Original_Record_Component (Entity (S)))
8452 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
8453 and then Present (Discriminant_Checking_Func
8454 (Original_Record_Component (Entity (S))))
8455 and then not Discriminant_Checks_Suppressed (T)
8456 and then not Init_Component
8458 Set_Do_Discriminant_Check (N);
8461 if Ekind (Entity (S)) = E_Void then
8462 Error_Msg_N ("premature use of component", S);
8465 -- If the prefix is a record conversion, this may be a renamed
8466 -- discriminant whose bounds differ from those of the original
8467 -- one, so we must ensure that a range check is performed.
8469 if Nkind (P) = N_Type_Conversion
8470 and then Ekind (Entity (S)) = E_Discriminant
8471 and then Is_Discrete_Type (Typ)
8473 Set_Etype (N, Base_Type (Typ));
8476 -- Note: No Eval processing is required, because the prefix is of a
8477 -- record type, or protected type, and neither can possibly be static.
8479 -- If the array type is atomic, and is packed, and we are in a left side
8480 -- context, then this is worth a warning, since we have a situation
8481 -- where the access to the component may cause extra read/writes of the
8482 -- atomic array object, which could be considered unexpected.
8484 if Nkind (N) = N_Selected_Component
8485 and then (Is_Atomic (T)
8486 or else (Is_Entity_Name (Prefix (N))
8487 and then Is_Atomic (Entity (Prefix (N)))))
8488 and then Is_Packed (T)
8491 Error_Msg_N ("?assignment to component of packed atomic record",
8493 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
8496 end Resolve_Selected_Component;
8502 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
8503 B_Typ : constant Entity_Id := Base_Type (Typ);
8504 L : constant Node_Id := Left_Opnd (N);
8505 R : constant Node_Id := Right_Opnd (N);
8508 -- We do the resolution using the base type, because intermediate values
8509 -- in expressions always are of the base type, not a subtype of it.
8512 Resolve (R, Standard_Natural);
8514 Check_Unset_Reference (L);
8515 Check_Unset_Reference (R);
8517 Set_Etype (N, B_Typ);
8518 Generate_Operator_Reference (N, B_Typ);
8522 ---------------------------
8523 -- Resolve_Short_Circuit --
8524 ---------------------------
8526 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
8527 B_Typ : constant Entity_Id := Base_Type (Typ);
8528 L : constant Node_Id := Left_Opnd (N);
8529 R : constant Node_Id := Right_Opnd (N);
8535 -- Check for issuing warning for always False assert/check, this happens
8536 -- when assertions are turned off, in which case the pragma Assert/Check
8537 -- was transformed into:
8539 -- if False and then <condition> then ...
8541 -- and we detect this pattern
8543 if Warn_On_Assertion_Failure
8544 and then Is_Entity_Name (R)
8545 and then Entity (R) = Standard_False
8546 and then Nkind (Parent (N)) = N_If_Statement
8547 and then Nkind (N) = N_And_Then
8548 and then Is_Entity_Name (L)
8549 and then Entity (L) = Standard_False
8552 Orig : constant Node_Id := Original_Node (Parent (N));
8555 if Nkind (Orig) = N_Pragma
8556 and then Pragma_Name (Orig) = Name_Assert
8558 -- Don't want to warn if original condition is explicit False
8561 Expr : constant Node_Id :=
8564 (First (Pragma_Argument_Associations (Orig))));
8566 if Is_Entity_Name (Expr)
8567 and then Entity (Expr) = Standard_False
8571 -- Issue warning. We do not want the deletion of the
8572 -- IF/AND-THEN to take this message with it. We achieve
8573 -- this by making sure that the expanded code points to
8574 -- the Sloc of the expression, not the original pragma.
8577 ("?assertion would fail at run time!",
8579 (First (Pragma_Argument_Associations (Orig))));
8583 -- Similar processing for Check pragma
8585 elsif Nkind (Orig) = N_Pragma
8586 and then Pragma_Name (Orig) = Name_Check
8588 -- Don't want to warn if original condition is explicit False
8591 Expr : constant Node_Id :=
8595 (Pragma_Argument_Associations (Orig)))));
8597 if Is_Entity_Name (Expr)
8598 and then Entity (Expr) = Standard_False
8603 ("?check would fail at run time!",
8605 (Last (Pragma_Argument_Associations (Orig))));
8612 -- Continue with processing of short circuit
8614 Check_Unset_Reference (L);
8615 Check_Unset_Reference (R);
8617 Set_Etype (N, B_Typ);
8618 Eval_Short_Circuit (N);
8619 end Resolve_Short_Circuit;
8625 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
8626 Name : constant Node_Id := Prefix (N);
8627 Drange : constant Node_Id := Discrete_Range (N);
8628 Array_Type : Entity_Id := Empty;
8632 if Is_Overloaded (Name) then
8634 -- Use the context type to select the prefix that yields the correct
8639 I1 : Interp_Index := 0;
8641 P : constant Node_Id := Prefix (N);
8642 Found : Boolean := False;
8645 Get_First_Interp (P, I, It);
8646 while Present (It.Typ) loop
8647 if (Is_Array_Type (It.Typ)
8648 and then Covers (Typ, It.Typ))
8649 or else (Is_Access_Type (It.Typ)
8650 and then Is_Array_Type (Designated_Type (It.Typ))
8651 and then Covers (Typ, Designated_Type (It.Typ)))
8654 It := Disambiguate (P, I1, I, Any_Type);
8656 if It = No_Interp then
8657 Error_Msg_N ("ambiguous prefix for slicing", N);
8662 Array_Type := It.Typ;
8667 Array_Type := It.Typ;
8672 Get_Next_Interp (I, It);
8677 Array_Type := Etype (Name);
8680 Resolve (Name, Array_Type);
8682 if Is_Access_Type (Array_Type) then
8683 Apply_Access_Check (N);
8684 Array_Type := Designated_Type (Array_Type);
8686 -- If the prefix is an access to an unconstrained array, we must use
8687 -- the actual subtype of the object to perform the index checks. The
8688 -- object denoted by the prefix is implicit in the node, so we build
8689 -- an explicit representation for it in order to compute the actual
8692 if not Is_Constrained (Array_Type) then
8693 Remove_Side_Effects (Prefix (N));
8696 Obj : constant Node_Id :=
8697 Make_Explicit_Dereference (Sloc (N),
8698 Prefix => New_Copy_Tree (Prefix (N)));
8700 Set_Etype (Obj, Array_Type);
8701 Set_Parent (Obj, Parent (N));
8702 Array_Type := Get_Actual_Subtype (Obj);
8706 elsif Is_Entity_Name (Name)
8707 or else Nkind (Name) = N_Explicit_Dereference
8708 or else (Nkind (Name) = N_Function_Call
8709 and then not Is_Constrained (Etype (Name)))
8711 Array_Type := Get_Actual_Subtype (Name);
8713 -- If the name is a selected component that depends on discriminants,
8714 -- build an actual subtype for it. This can happen only when the name
8715 -- itself is overloaded; otherwise the actual subtype is created when
8716 -- the selected component is analyzed.
8718 elsif Nkind (Name) = N_Selected_Component
8719 and then Full_Analysis
8720 and then Depends_On_Discriminant (First_Index (Array_Type))
8723 Act_Decl : constant Node_Id :=
8724 Build_Actual_Subtype_Of_Component (Array_Type, Name);
8726 Insert_Action (N, Act_Decl);
8727 Array_Type := Defining_Identifier (Act_Decl);
8730 -- Maybe this should just be "else", instead of checking for the
8731 -- specific case of slice??? This is needed for the case where the
8732 -- prefix is an Image attribute, which gets expanded to a slice, and so
8733 -- has a constrained subtype which we want to use for the slice range
8734 -- check applied below (the range check won't get done if the
8735 -- unconstrained subtype of the 'Image is used).
8737 elsif Nkind (Name) = N_Slice then
8738 Array_Type := Etype (Name);
8741 -- If name was overloaded, set slice type correctly now
8743 Set_Etype (N, Array_Type);
8745 -- If the range is specified by a subtype mark, no resolution is
8746 -- necessary. Else resolve the bounds, and apply needed checks.
8748 if not Is_Entity_Name (Drange) then
8749 Index := First_Index (Array_Type);
8750 Resolve (Drange, Base_Type (Etype (Index)));
8752 if Nkind (Drange) = N_Range then
8754 -- Ensure that side effects in the bounds are properly handled
8756 Force_Evaluation (Low_Bound (Drange));
8757 Force_Evaluation (High_Bound (Drange));
8759 -- Do not apply the range check to nodes associated with the
8760 -- frontend expansion of the dispatch table. We first check
8761 -- if Ada.Tags is already loaded to avoid the addition of an
8762 -- undesired dependence on such run-time unit.
8764 if not Tagged_Type_Expansion
8766 (RTU_Loaded (Ada_Tags)
8767 and then Nkind (Prefix (N)) = N_Selected_Component
8768 and then Present (Entity (Selector_Name (Prefix (N))))
8769 and then Entity (Selector_Name (Prefix (N))) =
8770 RTE_Record_Component (RE_Prims_Ptr))
8772 Apply_Range_Check (Drange, Etype (Index));
8777 Set_Slice_Subtype (N);
8779 -- Check bad use of type with predicates
8781 if Has_Predicates (Etype (Drange)) then
8782 Bad_Predicated_Subtype_Use
8783 ("subtype& has predicate, not allowed in slice",
8784 Drange, Etype (Drange));
8786 -- Otherwise here is where we check suspicious indexes
8788 elsif Nkind (Drange) = N_Range then
8789 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8790 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8796 ----------------------------
8797 -- Resolve_String_Literal --
8798 ----------------------------
8800 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8801 C_Typ : constant Entity_Id := Component_Type (Typ);
8802 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8803 Loc : constant Source_Ptr := Sloc (N);
8804 Str : constant String_Id := Strval (N);
8805 Strlen : constant Nat := String_Length (Str);
8806 Subtype_Id : Entity_Id;
8807 Need_Check : Boolean;
8810 -- For a string appearing in a concatenation, defer creation of the
8811 -- string_literal_subtype until the end of the resolution of the
8812 -- concatenation, because the literal may be constant-folded away. This
8813 -- is a useful optimization for long concatenation expressions.
8815 -- If the string is an aggregate built for a single character (which
8816 -- happens in a non-static context) or a is null string to which special
8817 -- checks may apply, we build the subtype. Wide strings must also get a
8818 -- string subtype if they come from a one character aggregate. Strings
8819 -- generated by attributes might be static, but it is often hard to
8820 -- determine whether the enclosing context is static, so we generate
8821 -- subtypes for them as well, thus losing some rarer optimizations ???
8822 -- Same for strings that come from a static conversion.
8825 (Strlen = 0 and then Typ /= Standard_String)
8826 or else Nkind (Parent (N)) /= N_Op_Concat
8827 or else (N /= Left_Opnd (Parent (N))
8828 and then N /= Right_Opnd (Parent (N)))
8829 or else ((Typ = Standard_Wide_String
8830 or else Typ = Standard_Wide_Wide_String)
8831 and then Nkind (Original_Node (N)) /= N_String_Literal);
8833 -- If the resolving type is itself a string literal subtype, we can just
8834 -- reuse it, since there is no point in creating another.
8836 if Ekind (Typ) = E_String_Literal_Subtype then
8839 elsif Nkind (Parent (N)) = N_Op_Concat
8840 and then not Need_Check
8841 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8842 N_Attribute_Reference,
8843 N_Qualified_Expression,
8848 -- Otherwise we must create a string literal subtype. Note that the
8849 -- whole idea of string literal subtypes is simply to avoid the need
8850 -- for building a full fledged array subtype for each literal.
8853 Set_String_Literal_Subtype (N, Typ);
8854 Subtype_Id := Etype (N);
8857 if Nkind (Parent (N)) /= N_Op_Concat
8860 Set_Etype (N, Subtype_Id);
8861 Eval_String_Literal (N);
8864 if Is_Limited_Composite (Typ)
8865 or else Is_Private_Composite (Typ)
8867 Error_Msg_N ("string literal not available for private array", N);
8868 Set_Etype (N, Any_Type);
8872 -- The validity of a null string has been checked in the call to
8873 -- Eval_String_Literal.
8878 -- Always accept string literal with component type Any_Character, which
8879 -- occurs in error situations and in comparisons of literals, both of
8880 -- which should accept all literals.
8882 elsif R_Typ = Any_Character then
8885 -- If the type is bit-packed, then we always transform the string
8886 -- literal into a full fledged aggregate.
8888 elsif Is_Bit_Packed_Array (Typ) then
8891 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8894 -- For Standard.Wide_Wide_String, or any other type whose component
8895 -- type is Standard.Wide_Wide_Character, we know that all the
8896 -- characters in the string must be acceptable, since the parser
8897 -- accepted the characters as valid character literals.
8899 if R_Typ = Standard_Wide_Wide_Character then
8902 -- For the case of Standard.String, or any other type whose component
8903 -- type is Standard.Character, we must make sure that there are no
8904 -- wide characters in the string, i.e. that it is entirely composed
8905 -- of characters in range of type Character.
8907 -- If the string literal is the result of a static concatenation, the
8908 -- test has already been performed on the components, and need not be
8911 elsif R_Typ = Standard_Character
8912 and then Nkind (Original_Node (N)) /= N_Op_Concat
8914 for J in 1 .. Strlen loop
8915 if not In_Character_Range (Get_String_Char (Str, J)) then
8917 -- If we are out of range, post error. This is one of the
8918 -- very few places that we place the flag in the middle of
8919 -- a token, right under the offending wide character. Not
8920 -- quite clear if this is right wrt wide character encoding
8921 -- sequences, but it's only an error message!
8924 ("literal out of range of type Standard.Character",
8925 Source_Ptr (Int (Loc) + J));
8930 -- For the case of Standard.Wide_String, or any other type whose
8931 -- component type is Standard.Wide_Character, we must make sure that
8932 -- there are no wide characters in the string, i.e. that it is
8933 -- entirely composed of characters in range of type Wide_Character.
8935 -- If the string literal is the result of a static concatenation,
8936 -- the test has already been performed on the components, and need
8939 elsif R_Typ = Standard_Wide_Character
8940 and then Nkind (Original_Node (N)) /= N_Op_Concat
8942 for J in 1 .. Strlen loop
8943 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8945 -- If we are out of range, post error. This is one of the
8946 -- very few places that we place the flag in the middle of
8947 -- a token, right under the offending wide character.
8949 -- This is not quite right, because characters in general
8950 -- will take more than one character position ???
8953 ("literal out of range of type Standard.Wide_Character",
8954 Source_Ptr (Int (Loc) + J));
8959 -- If the root type is not a standard character, then we will convert
8960 -- the string into an aggregate and will let the aggregate code do
8961 -- the checking. Standard Wide_Wide_Character is also OK here.
8967 -- See if the component type of the array corresponding to the string
8968 -- has compile time known bounds. If yes we can directly check
8969 -- whether the evaluation of the string will raise constraint error.
8970 -- Otherwise we need to transform the string literal into the
8971 -- corresponding character aggregate and let the aggregate code do
8974 if Is_Standard_Character_Type (R_Typ) then
8976 -- Check for the case of full range, where we are definitely OK
8978 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8982 -- Here the range is not the complete base type range, so check
8985 Comp_Typ_Lo : constant Node_Id :=
8986 Type_Low_Bound (Component_Type (Typ));
8987 Comp_Typ_Hi : constant Node_Id :=
8988 Type_High_Bound (Component_Type (Typ));
8993 if Compile_Time_Known_Value (Comp_Typ_Lo)
8994 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8996 for J in 1 .. Strlen loop
8997 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8999 if Char_Val < Expr_Value (Comp_Typ_Lo)
9000 or else Char_Val > Expr_Value (Comp_Typ_Hi)
9002 Apply_Compile_Time_Constraint_Error
9003 (N, "character out of range?", CE_Range_Check_Failed,
9004 Loc => Source_Ptr (Int (Loc) + J));
9014 -- If we got here we meed to transform the string literal into the
9015 -- equivalent qualified positional array aggregate. This is rather
9016 -- heavy artillery for this situation, but it is hard work to avoid.
9019 Lits : constant List_Id := New_List;
9020 P : Source_Ptr := Loc + 1;
9024 -- Build the character literals, we give them source locations that
9025 -- correspond to the string positions, which is a bit tricky given
9026 -- the possible presence of wide character escape sequences.
9028 for J in 1 .. Strlen loop
9029 C := Get_String_Char (Str, J);
9030 Set_Character_Literal_Name (C);
9033 Make_Character_Literal (P,
9035 Char_Literal_Value => UI_From_CC (C)));
9037 if In_Character_Range (C) then
9040 -- Should we have a call to Skip_Wide here ???
9049 Make_Qualified_Expression (Loc,
9050 Subtype_Mark => New_Reference_To (Typ, Loc),
9052 Make_Aggregate (Loc, Expressions => Lits)));
9054 Analyze_And_Resolve (N, Typ);
9056 end Resolve_String_Literal;
9058 -----------------------------
9059 -- Resolve_Subprogram_Info --
9060 -----------------------------
9062 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
9065 end Resolve_Subprogram_Info;
9067 -----------------------------
9068 -- Resolve_Type_Conversion --
9069 -----------------------------
9071 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
9072 Conv_OK : constant Boolean := Conversion_OK (N);
9073 Operand : constant Node_Id := Expression (N);
9074 Operand_Typ : constant Entity_Id := Etype (Operand);
9075 Target_Typ : constant Entity_Id := Etype (N);
9080 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
9081 -- Set to False to suppress cases where we want to suppress the test
9082 -- for redundancy to avoid possible false positives on this warning.
9086 and then not Valid_Conversion (N, Target_Typ, Operand)
9091 -- If the Operand Etype is Universal_Fixed, then the conversion is
9092 -- never redundant. We need this check because by the time we have
9093 -- finished the rather complex transformation, the conversion looks
9094 -- redundant when it is not.
9096 if Operand_Typ = Universal_Fixed then
9097 Test_Redundant := False;
9099 -- If the operand is marked as Any_Fixed, then special processing is
9100 -- required. This is also a case where we suppress the test for a
9101 -- redundant conversion, since most certainly it is not redundant.
9103 elsif Operand_Typ = Any_Fixed then
9104 Test_Redundant := False;
9106 -- Mixed-mode operation involving a literal. Context must be a fixed
9107 -- type which is applied to the literal subsequently.
9109 if Is_Fixed_Point_Type (Typ) then
9110 Set_Etype (Operand, Universal_Real);
9112 elsif Is_Numeric_Type (Typ)
9113 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
9114 and then (Etype (Right_Opnd (Operand)) = Universal_Real
9116 Etype (Left_Opnd (Operand)) = Universal_Real)
9118 -- Return if expression is ambiguous
9120 if Unique_Fixed_Point_Type (N) = Any_Type then
9123 -- If nothing else, the available fixed type is Duration
9126 Set_Etype (Operand, Standard_Duration);
9129 -- Resolve the real operand with largest available precision
9131 if Etype (Right_Opnd (Operand)) = Universal_Real then
9132 Rop := New_Copy_Tree (Right_Opnd (Operand));
9134 Rop := New_Copy_Tree (Left_Opnd (Operand));
9137 Resolve (Rop, Universal_Real);
9139 -- If the operand is a literal (it could be a non-static and
9140 -- illegal exponentiation) check whether the use of Duration
9141 -- is potentially inaccurate.
9143 if Nkind (Rop) = N_Real_Literal
9144 and then Realval (Rop) /= Ureal_0
9145 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9148 ("?universal real operand can only " &
9149 "be interpreted as Duration!",
9152 ("\?precision will be lost in the conversion!", Rop);
9155 elsif Is_Numeric_Type (Typ)
9156 and then Nkind (Operand) in N_Op
9157 and then Unique_Fixed_Point_Type (N) /= Any_Type
9159 Set_Etype (Operand, Standard_Duration);
9162 Error_Msg_N ("invalid context for mixed mode operation", N);
9163 Set_Etype (Operand, Any_Type);
9170 -- In SPARK, a type conversion between array types should be restricted
9171 -- to types which have matching static bounds.
9173 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9174 -- operation if not needed.
9176 if Restriction_Check_Required (SPARK)
9177 and then Is_Array_Type (Target_Typ)
9178 and then Is_Array_Type (Operand_Typ)
9179 and then Operand_Typ /= Any_Composite -- or else Operand in error
9180 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
9182 Check_SPARK_Restriction
9183 ("array types should have matching static bounds", N);
9186 -- In formal mode, the operand of an ancestor type conversion must be an
9187 -- object (not an expression).
9189 if Is_Tagged_Type (Target_Typ)
9190 and then not Is_Class_Wide_Type (Target_Typ)
9191 and then Is_Tagged_Type (Operand_Typ)
9192 and then not Is_Class_Wide_Type (Operand_Typ)
9193 and then Is_Ancestor (Target_Typ, Operand_Typ)
9194 and then not Is_SPARK_Object_Reference (Operand)
9196 Check_SPARK_Restriction ("object required", Operand);
9199 -- Note: we do the Eval_Type_Conversion call before applying the
9200 -- required checks for a subtype conversion. This is important, since
9201 -- both are prepared under certain circumstances to change the type
9202 -- conversion to a constraint error node, but in the case of
9203 -- Eval_Type_Conversion this may reflect an illegality in the static
9204 -- case, and we would miss the illegality (getting only a warning
9205 -- message), if we applied the type conversion checks first.
9207 Eval_Type_Conversion (N);
9209 -- Even when evaluation is not possible, we may be able to simplify the
9210 -- conversion or its expression. This needs to be done before applying
9211 -- checks, since otherwise the checks may use the original expression
9212 -- and defeat the simplifications. This is specifically the case for
9213 -- elimination of the floating-point Truncation attribute in
9214 -- float-to-int conversions.
9216 Simplify_Type_Conversion (N);
9218 -- If after evaluation we still have a type conversion, then we may need
9219 -- to apply checks required for a subtype conversion.
9221 -- Skip these type conversion checks if universal fixed operands
9222 -- operands involved, since range checks are handled separately for
9223 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9225 if Nkind (N) = N_Type_Conversion
9226 and then not Is_Generic_Type (Root_Type (Target_Typ))
9227 and then Target_Typ /= Universal_Fixed
9228 and then Operand_Typ /= Universal_Fixed
9230 Apply_Type_Conversion_Checks (N);
9233 -- Issue warning for conversion of simple object to its own type. We
9234 -- have to test the original nodes, since they may have been rewritten
9235 -- by various optimizations.
9237 Orig_N := Original_Node (N);
9239 -- Here we test for a redundant conversion if the warning mode is
9240 -- active (and was not locally reset), and we have a type conversion
9241 -- from source not appearing in a generic instance.
9244 and then Nkind (Orig_N) = N_Type_Conversion
9245 and then Comes_From_Source (Orig_N)
9246 and then not In_Instance
9248 Orig_N := Original_Node (Expression (Orig_N));
9249 Orig_T := Target_Typ;
9251 -- If the node is part of a larger expression, the Target_Type
9252 -- may not be the original type of the node if the context is a
9253 -- condition. Recover original type to see if conversion is needed.
9255 if Is_Boolean_Type (Orig_T)
9256 and then Nkind (Parent (N)) in N_Op
9258 Orig_T := Etype (Parent (N));
9261 -- If we have an entity name, then give the warning if the entity
9262 -- is the right type, or if it is a loop parameter covered by the
9263 -- original type (that's needed because loop parameters have an
9264 -- odd subtype coming from the bounds).
9266 if (Is_Entity_Name (Orig_N)
9268 (Etype (Entity (Orig_N)) = Orig_T
9270 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
9271 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
9273 -- If not an entity, then type of expression must match
9275 or else Etype (Orig_N) = Orig_T
9277 -- One more check, do not give warning if the analyzed conversion
9278 -- has an expression with non-static bounds, and the bounds of the
9279 -- target are static. This avoids junk warnings in cases where the
9280 -- conversion is necessary to establish staticness, for example in
9281 -- a case statement.
9283 if not Is_OK_Static_Subtype (Operand_Typ)
9284 and then Is_OK_Static_Subtype (Target_Typ)
9288 -- Finally, if this type conversion occurs in a context requiring
9289 -- a prefix, and the expression is a qualified expression then the
9290 -- type conversion is not redundant, since a qualified expression
9291 -- is not a prefix, whereas a type conversion is. For example, "X
9292 -- := T'(Funx(...)).Y;" is illegal because a selected component
9293 -- requires a prefix, but a type conversion makes it legal: "X :=
9294 -- T(T'(Funx(...))).Y;"
9296 -- In Ada 2012, a qualified expression is a name, so this idiom is
9297 -- no longer needed, but we still suppress the warning because it
9298 -- seems unfriendly for warnings to pop up when you switch to the
9299 -- newer language version.
9301 elsif Nkind (Orig_N) = N_Qualified_Expression
9302 and then Nkind_In (Parent (N), N_Attribute_Reference,
9303 N_Indexed_Component,
9304 N_Selected_Component,
9306 N_Explicit_Dereference)
9310 -- Here we give the redundant conversion warning. If it is an
9311 -- entity, give the name of the entity in the message. If not,
9312 -- just mention the expression.
9315 if Is_Entity_Name (Orig_N) then
9316 Error_Msg_Node_2 := Orig_T;
9317 Error_Msg_NE -- CODEFIX
9318 ("?redundant conversion, & is of type &!",
9319 N, Entity (Orig_N));
9322 ("?redundant conversion, expression is of type&!",
9329 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
9330 -- No need to perform any interface conversion if the type of the
9331 -- expression coincides with the target type.
9333 if Ada_Version >= Ada_2005
9334 and then Expander_Active
9335 and then Operand_Typ /= Target_Typ
9338 Opnd : Entity_Id := Operand_Typ;
9339 Target : Entity_Id := Target_Typ;
9342 if Is_Access_Type (Opnd) then
9343 Opnd := Designated_Type (Opnd);
9346 if Is_Access_Type (Target_Typ) then
9347 Target := Designated_Type (Target);
9350 if Opnd = Target then
9353 -- Conversion from interface type
9355 elsif Is_Interface (Opnd) then
9357 -- Ada 2005 (AI-217): Handle entities from limited views
9359 if From_With_Type (Opnd) then
9360 Error_Msg_Qual_Level := 99;
9361 Error_Msg_NE -- CODEFIX
9362 ("missing WITH clause on package &", N,
9363 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
9365 ("type conversions require visibility of the full view",
9368 elsif From_With_Type (Target)
9370 (Is_Access_Type (Target_Typ)
9371 and then Present (Non_Limited_View (Etype (Target))))
9373 Error_Msg_Qual_Level := 99;
9374 Error_Msg_NE -- CODEFIX
9375 ("missing WITH clause on package &", N,
9376 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
9378 ("type conversions require visibility of the full view",
9382 Expand_Interface_Conversion (N, Is_Static => False);
9385 -- Conversion to interface type
9387 elsif Is_Interface (Target) then
9391 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
9392 Opnd := Etype (Opnd);
9395 if not Interface_Present_In_Ancestor
9399 if Is_Class_Wide_Type (Opnd) then
9401 -- The static analysis is not enough to know if the
9402 -- interface is implemented or not. Hence we must pass
9403 -- the work to the expander to generate code to evaluate
9404 -- the conversion at run time.
9406 Expand_Interface_Conversion (N, Is_Static => False);
9409 Error_Msg_Name_1 := Chars (Etype (Target));
9410 Error_Msg_Name_2 := Chars (Opnd);
9412 ("wrong interface conversion (% is not a progenitor " &
9417 Expand_Interface_Conversion (N);
9422 end Resolve_Type_Conversion;
9424 ----------------------
9425 -- Resolve_Unary_Op --
9426 ----------------------
9428 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
9429 B_Typ : constant Entity_Id := Base_Type (Typ);
9430 R : constant Node_Id := Right_Opnd (N);
9436 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
9437 Error_Msg_Name_1 := Chars (Typ);
9438 Check_SPARK_Restriction
9439 ("unary operator not defined for modular type%", N);
9442 -- Deal with intrinsic unary operators
9444 if Comes_From_Source (N)
9445 and then Ekind (Entity (N)) = E_Function
9446 and then Is_Imported (Entity (N))
9447 and then Is_Intrinsic_Subprogram (Entity (N))
9449 Resolve_Intrinsic_Unary_Operator (N, Typ);
9453 -- Deal with universal cases
9455 if Etype (R) = Universal_Integer
9457 Etype (R) = Universal_Real
9459 Check_For_Visible_Operator (N, B_Typ);
9462 Set_Etype (N, B_Typ);
9465 -- Generate warning for expressions like abs (x mod 2)
9467 if Warn_On_Redundant_Constructs
9468 and then Nkind (N) = N_Op_Abs
9470 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
9472 if OK and then Hi >= Lo and then Lo >= 0 then
9473 Error_Msg_N -- CODEFIX
9474 ("?abs applied to known non-negative value has no effect", N);
9478 -- Deal with reference generation
9480 Check_Unset_Reference (R);
9481 Generate_Operator_Reference (N, B_Typ);
9484 -- Set overflow checking bit. Much cleverer code needed here eventually
9485 -- and perhaps the Resolve routines should be separated for the various
9486 -- arithmetic operations, since they will need different processing ???
9488 if Nkind (N) in N_Op then
9489 if not Overflow_Checks_Suppressed (Etype (N)) then
9490 Enable_Overflow_Check (N);
9494 -- Generate warning for expressions like -5 mod 3 for integers. No need
9495 -- to worry in the floating-point case, since parens do not affect the
9496 -- result so there is no point in giving in a warning.
9499 Norig : constant Node_Id := Original_Node (N);
9508 if Warn_On_Questionable_Missing_Parens
9509 and then Comes_From_Source (Norig)
9510 and then Is_Integer_Type (Typ)
9511 and then Nkind (Norig) = N_Op_Minus
9513 Rorig := Original_Node (Right_Opnd (Norig));
9515 -- We are looking for cases where the right operand is not
9516 -- parenthesized, and is a binary operator, multiply, divide, or
9517 -- mod. These are the cases where the grouping can affect results.
9519 if Paren_Count (Rorig) = 0
9520 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
9522 -- For mod, we always give the warning, since the value is
9523 -- affected by the parenthesization (e.g. (-5) mod 315 /=
9524 -- -(5 mod 315)). But for the other cases, the only concern is
9525 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
9526 -- overflows, but (-2) * 64 does not). So we try to give the
9527 -- message only when overflow is possible.
9529 if Nkind (Rorig) /= N_Op_Mod
9530 and then Compile_Time_Known_Value (R)
9532 Val := Expr_Value (R);
9534 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
9535 HB := Expr_Value (Type_High_Bound (Typ));
9537 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
9540 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
9541 LB := Expr_Value (Type_Low_Bound (Typ));
9543 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
9546 -- Note that the test below is deliberately excluding the
9547 -- largest negative number, since that is a potentially
9548 -- troublesome case (e.g. -2 * x, where the result is the
9549 -- largest negative integer has an overflow with 2 * x).
9551 if Val > LB and then Val <= HB then
9556 -- For the multiplication case, the only case we have to worry
9557 -- about is when (-a)*b is exactly the largest negative number
9558 -- so that -(a*b) can cause overflow. This can only happen if
9559 -- a is a power of 2, and more generally if any operand is a
9560 -- constant that is not a power of 2, then the parentheses
9561 -- cannot affect whether overflow occurs. We only bother to
9562 -- test the left most operand
9564 -- Loop looking at left operands for one that has known value
9567 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
9568 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
9569 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
9571 -- Operand value of 0 or 1 skips warning
9576 -- Otherwise check power of 2, if power of 2, warn, if
9577 -- anything else, skip warning.
9580 while Lval /= 2 loop
9581 if Lval mod 2 = 1 then
9592 -- Keep looking at left operands
9594 Opnd := Left_Opnd (Opnd);
9597 -- For rem or "/" we can only have a problematic situation
9598 -- if the divisor has a value of minus one or one. Otherwise
9599 -- overflow is impossible (divisor > 1) or we have a case of
9600 -- division by zero in any case.
9602 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
9603 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
9604 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
9609 -- If we fall through warning should be issued
9612 ("?unary minus expression should be parenthesized here!", N);
9616 end Resolve_Unary_Op;
9618 ----------------------------------
9619 -- Resolve_Unchecked_Expression --
9620 ----------------------------------
9622 procedure Resolve_Unchecked_Expression
9627 Resolve (Expression (N), Typ, Suppress => All_Checks);
9629 end Resolve_Unchecked_Expression;
9631 ---------------------------------------
9632 -- Resolve_Unchecked_Type_Conversion --
9633 ---------------------------------------
9635 procedure Resolve_Unchecked_Type_Conversion
9639 pragma Warnings (Off, Typ);
9641 Operand : constant Node_Id := Expression (N);
9642 Opnd_Type : constant Entity_Id := Etype (Operand);
9645 -- Resolve operand using its own type
9647 Resolve (Operand, Opnd_Type);
9648 Eval_Unchecked_Conversion (N);
9649 end Resolve_Unchecked_Type_Conversion;
9651 ------------------------------
9652 -- Rewrite_Operator_As_Call --
9653 ------------------------------
9655 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
9656 Loc : constant Source_Ptr := Sloc (N);
9657 Actuals : constant List_Id := New_List;
9661 if Nkind (N) in N_Binary_Op then
9662 Append (Left_Opnd (N), Actuals);
9665 Append (Right_Opnd (N), Actuals);
9668 Make_Function_Call (Sloc => Loc,
9669 Name => New_Occurrence_Of (Nam, Loc),
9670 Parameter_Associations => Actuals);
9672 Preserve_Comes_From_Source (New_N, N);
9673 Preserve_Comes_From_Source (Name (New_N), N);
9675 Set_Etype (N, Etype (Nam));
9676 end Rewrite_Operator_As_Call;
9678 ------------------------------
9679 -- Rewrite_Renamed_Operator --
9680 ------------------------------
9682 procedure Rewrite_Renamed_Operator
9687 Nam : constant Name_Id := Chars (Op);
9688 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
9692 -- Rewrite the operator node using the real operator, not its renaming.
9693 -- Exclude user-defined intrinsic operations of the same name, which are
9694 -- treated separately and rewritten as calls.
9696 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
9697 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
9698 Set_Chars (Op_Node, Nam);
9699 Set_Etype (Op_Node, Etype (N));
9700 Set_Entity (Op_Node, Op);
9701 Set_Right_Opnd (Op_Node, Right_Opnd (N));
9703 -- Indicate that both the original entity and its renaming are
9704 -- referenced at this point.
9706 Generate_Reference (Entity (N), N);
9707 Generate_Reference (Op, N);
9710 Set_Left_Opnd (Op_Node, Left_Opnd (N));
9713 Rewrite (N, Op_Node);
9715 -- If the context type is private, add the appropriate conversions so
9716 -- that the operator is applied to the full view. This is done in the
9717 -- routines that resolve intrinsic operators.
9719 if Is_Intrinsic_Subprogram (Op)
9720 and then Is_Private_Type (Typ)
9723 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
9724 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
9725 Resolve_Intrinsic_Operator (N, Typ);
9727 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
9728 Resolve_Intrinsic_Unary_Operator (N, Typ);
9735 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
9737 -- Operator renames a user-defined operator of the same name. Use the
9738 -- original operator in the node, which is the one Gigi knows about.
9741 Set_Is_Overloaded (N, False);
9743 end Rewrite_Renamed_Operator;
9745 -----------------------
9746 -- Set_Slice_Subtype --
9747 -----------------------
9749 -- Build an implicit subtype declaration to represent the type delivered by
9750 -- the slice. This is an abbreviated version of an array subtype. We define
9751 -- an index subtype for the slice, using either the subtype name or the
9752 -- discrete range of the slice. To be consistent with index usage elsewhere
9753 -- we create a list header to hold the single index. This list is not
9754 -- otherwise attached to the syntax tree.
9756 procedure Set_Slice_Subtype (N : Node_Id) is
9757 Loc : constant Source_Ptr := Sloc (N);
9758 Index_List : constant List_Id := New_List;
9760 Index_Subtype : Entity_Id;
9761 Index_Type : Entity_Id;
9762 Slice_Subtype : Entity_Id;
9763 Drange : constant Node_Id := Discrete_Range (N);
9766 if Is_Entity_Name (Drange) then
9767 Index_Subtype := Entity (Drange);
9770 -- We force the evaluation of a range. This is definitely needed in
9771 -- the renamed case, and seems safer to do unconditionally. Note in
9772 -- any case that since we will create and insert an Itype referring
9773 -- to this range, we must make sure any side effect removal actions
9774 -- are inserted before the Itype definition.
9776 if Nkind (Drange) = N_Range then
9777 Force_Evaluation (Low_Bound (Drange));
9778 Force_Evaluation (High_Bound (Drange));
9781 Index_Type := Base_Type (Etype (Drange));
9783 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9785 -- Take a new copy of Drange (where bounds have been rewritten to
9786 -- reference side-effect-free names). Using a separate tree ensures
9787 -- that further expansion (e.g. while rewriting a slice assignment
9788 -- into a FOR loop) does not attempt to remove side effects on the
9789 -- bounds again (which would cause the bounds in the index subtype
9790 -- definition to refer to temporaries before they are defined) (the
9791 -- reason is that some names are considered side effect free here
9792 -- for the subtype, but not in the context of a loop iteration
9795 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
9796 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
9797 Set_Etype (Index_Subtype, Index_Type);
9798 Set_Size_Info (Index_Subtype, Index_Type);
9799 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9802 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
9804 Index := New_Occurrence_Of (Index_Subtype, Loc);
9805 Set_Etype (Index, Index_Subtype);
9806 Append (Index, Index_List);
9808 Set_First_Index (Slice_Subtype, Index);
9809 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
9810 Set_Is_Constrained (Slice_Subtype, True);
9812 Check_Compile_Time_Size (Slice_Subtype);
9814 -- The Etype of the existing Slice node is reset to this slice subtype.
9815 -- Its bounds are obtained from its first index.
9817 Set_Etype (N, Slice_Subtype);
9819 -- For packed slice subtypes, freeze immediately (except in the case of
9820 -- being in a "spec expression" where we never freeze when we first see
9823 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
9824 Freeze_Itype (Slice_Subtype, N);
9826 -- For all other cases insert an itype reference in the slice's actions
9827 -- so that the itype is frozen at the proper place in the tree (i.e. at
9828 -- the point where actions for the slice are analyzed). Note that this
9829 -- is different from freezing the itype immediately, which might be
9830 -- premature (e.g. if the slice is within a transient scope). This needs
9831 -- to be done only if expansion is enabled.
9833 elsif Expander_Active then
9834 Ensure_Defined (Typ => Slice_Subtype, N => N);
9836 end Set_Slice_Subtype;
9838 --------------------------------
9839 -- Set_String_Literal_Subtype --
9840 --------------------------------
9842 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
9843 Loc : constant Source_Ptr := Sloc (N);
9844 Low_Bound : constant Node_Id :=
9845 Type_Low_Bound (Etype (First_Index (Typ)));
9846 Subtype_Id : Entity_Id;
9849 if Nkind (N) /= N_String_Literal then
9853 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
9854 Set_String_Literal_Length (Subtype_Id, UI_From_Int
9855 (String_Length (Strval (N))));
9856 Set_Etype (Subtype_Id, Base_Type (Typ));
9857 Set_Is_Constrained (Subtype_Id);
9858 Set_Etype (N, Subtype_Id);
9860 if Is_OK_Static_Expression (Low_Bound) then
9862 -- The low bound is set from the low bound of the corresponding index
9863 -- type. Note that we do not store the high bound in the string literal
9864 -- subtype, but it can be deduced if necessary from the length and the
9867 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
9870 -- If the lower bound is not static we create a range for the string
9871 -- literal, using the index type and the known length of the literal.
9872 -- The index type is not necessarily Positive, so the upper bound is
9873 -- computed as T'Val (T'Pos (Low_Bound) + L - 1)
9876 Index_List : constant List_Id := New_List;
9877 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9879 High_Bound : constant Node_Id :=
9880 Make_Attribute_Reference (Loc,
9881 Attribute_Name => Name_Val,
9883 New_Occurrence_Of (Index_Type, Loc),
9884 Expressions => New_List (
9887 Make_Attribute_Reference (Loc,
9888 Attribute_Name => Name_Pos,
9890 New_Occurrence_Of (Index_Type, Loc),
9892 New_List (New_Copy_Tree (Low_Bound))),
9894 Make_Integer_Literal (Loc,
9895 String_Length (Strval (N)) - 1))));
9897 Array_Subtype : Entity_Id;
9898 Index_Subtype : Entity_Id;
9903 if Is_Integer_Type (Index_Type) then
9904 Set_String_Literal_Low_Bound
9905 (Subtype_Id, Make_Integer_Literal (Loc, 1));
9908 -- If the index type is an enumeration type, build bounds
9909 -- expression with attributes.
9911 Set_String_Literal_Low_Bound
9913 Make_Attribute_Reference (Loc,
9914 Attribute_Name => Name_First,
9916 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
9917 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
9920 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
9922 -- Build bona fide subtype for the string, and wrap it in an
9923 -- unchecked conversion, because the backend expects the
9924 -- String_Literal_Subtype to have a static lower bound.
9927 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9928 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
9929 Set_Scalar_Range (Index_Subtype, Drange);
9930 Set_Parent (Drange, N);
9931 Analyze_And_Resolve (Drange, Index_Type);
9933 -- In the context, the Index_Type may already have a constraint,
9934 -- so use common base type on string subtype. The base type may
9935 -- be used when generating attributes of the string, for example
9936 -- in the context of a slice assignment.
9938 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9939 Set_Size_Info (Index_Subtype, Index_Type);
9940 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9942 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9944 Index := New_Occurrence_Of (Index_Subtype, Loc);
9945 Set_Etype (Index, Index_Subtype);
9946 Append (Index, Index_List);
9948 Set_First_Index (Array_Subtype, Index);
9949 Set_Etype (Array_Subtype, Base_Type (Typ));
9950 Set_Is_Constrained (Array_Subtype, True);
9953 Make_Unchecked_Type_Conversion (Loc,
9954 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9955 Expression => Relocate_Node (N)));
9956 Set_Etype (N, Array_Subtype);
9959 end Set_String_Literal_Subtype;
9961 ------------------------------
9962 -- Simplify_Type_Conversion --
9963 ------------------------------
9965 procedure Simplify_Type_Conversion (N : Node_Id) is
9967 if Nkind (N) = N_Type_Conversion then
9969 Operand : constant Node_Id := Expression (N);
9970 Target_Typ : constant Entity_Id := Etype (N);
9971 Opnd_Typ : constant Entity_Id := Etype (Operand);
9974 if Is_Floating_Point_Type (Opnd_Typ)
9976 (Is_Integer_Type (Target_Typ)
9977 or else (Is_Fixed_Point_Type (Target_Typ)
9978 and then Conversion_OK (N)))
9979 and then Nkind (Operand) = N_Attribute_Reference
9980 and then Attribute_Name (Operand) = Name_Truncation
9982 -- Special processing required if the conversion is the expression
9983 -- of a Truncation attribute reference. In this case we replace:
9985 -- ityp (ftyp'Truncation (x))
9991 -- with the Float_Truncate flag set, which is more efficient.
9995 Relocate_Node (First (Expressions (Operand))));
9996 Set_Float_Truncate (N, True);
10000 end Simplify_Type_Conversion;
10002 -----------------------------
10003 -- Unique_Fixed_Point_Type --
10004 -----------------------------
10006 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
10007 T1 : Entity_Id := Empty;
10012 procedure Fixed_Point_Error;
10013 -- Give error messages for true ambiguity. Messages are posted on node
10014 -- N, and entities T1, T2 are the possible interpretations.
10016 -----------------------
10017 -- Fixed_Point_Error --
10018 -----------------------
10020 procedure Fixed_Point_Error is
10022 Error_Msg_N ("ambiguous universal_fixed_expression", N);
10023 Error_Msg_NE ("\\possible interpretation as}", N, T1);
10024 Error_Msg_NE ("\\possible interpretation as}", N, T2);
10025 end Fixed_Point_Error;
10027 -- Start of processing for Unique_Fixed_Point_Type
10030 -- The operations on Duration are visible, so Duration is always a
10031 -- possible interpretation.
10033 T1 := Standard_Duration;
10035 -- Look for fixed-point types in enclosing scopes
10037 Scop := Current_Scope;
10038 while Scop /= Standard_Standard loop
10039 T2 := First_Entity (Scop);
10040 while Present (T2) loop
10041 if Is_Fixed_Point_Type (T2)
10042 and then Current_Entity (T2) = T2
10043 and then Scope (Base_Type (T2)) = Scop
10045 if Present (T1) then
10056 Scop := Scope (Scop);
10059 -- Look for visible fixed type declarations in the context
10061 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
10062 while Present (Item) loop
10063 if Nkind (Item) = N_With_Clause then
10064 Scop := Entity (Name (Item));
10065 T2 := First_Entity (Scop);
10066 while Present (T2) loop
10067 if Is_Fixed_Point_Type (T2)
10068 and then Scope (Base_Type (T2)) = Scop
10069 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
10071 if Present (T1) then
10086 if Nkind (N) = N_Real_Literal then
10087 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
10089 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
10093 end Unique_Fixed_Point_Type;
10095 ----------------------
10096 -- Valid_Conversion --
10097 ----------------------
10099 function Valid_Conversion
10101 Target : Entity_Id;
10102 Operand : Node_Id) return Boolean
10104 Target_Type : constant Entity_Id := Base_Type (Target);
10105 Opnd_Type : Entity_Id := Etype (Operand);
10107 function Conversion_Check
10109 Msg : String) return Boolean;
10110 -- Little routine to post Msg if Valid is False, returns Valid value
10112 function Valid_Tagged_Conversion
10113 (Target_Type : Entity_Id;
10114 Opnd_Type : Entity_Id) return Boolean;
10115 -- Specifically test for validity of tagged conversions
10117 function Valid_Array_Conversion return Boolean;
10118 -- Check index and component conformance, and accessibility levels if
10119 -- the component types are anonymous access types (Ada 2005).
10121 ----------------------
10122 -- Conversion_Check --
10123 ----------------------
10125 function Conversion_Check
10127 Msg : String) return Boolean
10131 Error_Msg_N (Msg, Operand);
10135 end Conversion_Check;
10137 ----------------------------
10138 -- Valid_Array_Conversion --
10139 ----------------------------
10141 function Valid_Array_Conversion return Boolean
10143 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
10144 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
10146 Opnd_Index : Node_Id;
10147 Opnd_Index_Type : Entity_Id;
10149 Target_Comp_Type : constant Entity_Id :=
10150 Component_Type (Target_Type);
10151 Target_Comp_Base : constant Entity_Id :=
10152 Base_Type (Target_Comp_Type);
10154 Target_Index : Node_Id;
10155 Target_Index_Type : Entity_Id;
10158 -- Error if wrong number of dimensions
10161 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
10164 ("incompatible number of dimensions for conversion", Operand);
10167 -- Number of dimensions matches
10170 -- Loop through indexes of the two arrays
10172 Target_Index := First_Index (Target_Type);
10173 Opnd_Index := First_Index (Opnd_Type);
10174 while Present (Target_Index) and then Present (Opnd_Index) loop
10175 Target_Index_Type := Etype (Target_Index);
10176 Opnd_Index_Type := Etype (Opnd_Index);
10178 -- Error if index types are incompatible
10180 if not (Is_Integer_Type (Target_Index_Type)
10181 and then Is_Integer_Type (Opnd_Index_Type))
10182 and then (Root_Type (Target_Index_Type)
10183 /= Root_Type (Opnd_Index_Type))
10186 ("incompatible index types for array conversion",
10191 Next_Index (Target_Index);
10192 Next_Index (Opnd_Index);
10195 -- If component types have same base type, all set
10197 if Target_Comp_Base = Opnd_Comp_Base then
10200 -- Here if base types of components are not the same. The only
10201 -- time this is allowed is if we have anonymous access types.
10203 -- The conversion of arrays of anonymous access types can lead
10204 -- to dangling pointers. AI-392 formalizes the accessibility
10205 -- checks that must be applied to such conversions to prevent
10206 -- out-of-scope references.
10209 (Target_Comp_Base, E_Anonymous_Access_Type,
10210 E_Anonymous_Access_Subprogram_Type)
10211 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
10213 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
10215 if Type_Access_Level (Target_Type) <
10216 Type_Access_Level (Opnd_Type)
10218 if In_Instance_Body then
10219 Error_Msg_N ("?source array type " &
10220 "has deeper accessibility level than target", Operand);
10221 Error_Msg_N ("\?Program_Error will be raised at run time",
10224 Make_Raise_Program_Error (Sloc (N),
10225 Reason => PE_Accessibility_Check_Failed));
10226 Set_Etype (N, Target_Type);
10229 -- Conversion not allowed because of accessibility levels
10232 Error_Msg_N ("source array type " &
10233 "has deeper accessibility level than target", Operand);
10241 -- All other cases where component base types do not match
10245 ("incompatible component types for array conversion",
10250 -- Check that component subtypes statically match. For numeric
10251 -- types this means that both must be either constrained or
10252 -- unconstrained. For enumeration types the bounds must match.
10253 -- All of this is checked in Subtypes_Statically_Match.
10255 if not Subtypes_Statically_Match
10256 (Target_Comp_Type, Opnd_Comp_Type)
10259 ("component subtypes must statically match", Operand);
10265 end Valid_Array_Conversion;
10267 -----------------------------
10268 -- Valid_Tagged_Conversion --
10269 -----------------------------
10271 function Valid_Tagged_Conversion
10272 (Target_Type : Entity_Id;
10273 Opnd_Type : Entity_Id) return Boolean
10276 -- Upward conversions are allowed (RM 4.6(22))
10278 if Covers (Target_Type, Opnd_Type)
10279 or else Is_Ancestor (Target_Type, Opnd_Type)
10283 -- Downward conversion are allowed if the operand is class-wide
10286 elsif Is_Class_Wide_Type (Opnd_Type)
10287 and then Covers (Opnd_Type, Target_Type)
10291 elsif Covers (Opnd_Type, Target_Type)
10292 or else Is_Ancestor (Opnd_Type, Target_Type)
10295 Conversion_Check (False,
10296 "downward conversion of tagged objects not allowed");
10298 -- Ada 2005 (AI-251): The conversion to/from interface types is
10301 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
10304 -- If the operand is a class-wide type obtained through a limited_
10305 -- with clause, and the context includes the non-limited view, use
10306 -- it to determine whether the conversion is legal.
10308 elsif Is_Class_Wide_Type (Opnd_Type)
10309 and then From_With_Type (Opnd_Type)
10310 and then Present (Non_Limited_View (Etype (Opnd_Type)))
10311 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
10315 elsif Is_Access_Type (Opnd_Type)
10316 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
10322 ("invalid tagged conversion, not compatible with}",
10323 N, First_Subtype (Opnd_Type));
10326 end Valid_Tagged_Conversion;
10328 -- Start of processing for Valid_Conversion
10331 Check_Parameterless_Call (Operand);
10333 if Is_Overloaded (Operand) then
10343 -- Remove procedure calls, which syntactically cannot appear in
10344 -- this context, but which cannot be removed by type checking,
10345 -- because the context does not impose a type.
10347 -- When compiling for VMS, spurious ambiguities can be produced
10348 -- when arithmetic operations have a literal operand and return
10349 -- System.Address or a descendant of it. These ambiguities are
10350 -- otherwise resolved by the context, but for conversions there
10351 -- is no context type and the removal of the spurious operations
10352 -- must be done explicitly here.
10354 -- The node may be labelled overloaded, but still contain only one
10355 -- interpretation because others were discarded earlier. If this
10356 -- is the case, retain the single interpretation if legal.
10358 Get_First_Interp (Operand, I, It);
10359 Opnd_Type := It.Typ;
10360 Get_Next_Interp (I, It);
10362 if Present (It.Typ)
10363 and then Opnd_Type /= Standard_Void_Type
10365 -- More than one candidate interpretation is available
10367 Get_First_Interp (Operand, I, It);
10368 while Present (It.Typ) loop
10369 if It.Typ = Standard_Void_Type then
10373 if Present (System_Aux_Id)
10374 and then Is_Descendent_Of_Address (It.Typ)
10379 Get_Next_Interp (I, It);
10383 Get_First_Interp (Operand, I, It);
10387 if No (It.Typ) then
10388 Error_Msg_N ("illegal operand in conversion", Operand);
10392 Get_Next_Interp (I, It);
10394 if Present (It.Typ) then
10397 It1 := Disambiguate (Operand, I1, I, Any_Type);
10399 if It1 = No_Interp then
10400 Error_Msg_N ("ambiguous operand in conversion", Operand);
10402 -- If the interpretation involves a standard operator, use
10403 -- the location of the type, which may be user-defined.
10405 if Sloc (It.Nam) = Standard_Location then
10406 Error_Msg_Sloc := Sloc (It.Typ);
10408 Error_Msg_Sloc := Sloc (It.Nam);
10411 Error_Msg_N -- CODEFIX
10412 ("\\possible interpretation#!", Operand);
10414 if Sloc (N1) = Standard_Location then
10415 Error_Msg_Sloc := Sloc (T1);
10417 Error_Msg_Sloc := Sloc (N1);
10420 Error_Msg_N -- CODEFIX
10421 ("\\possible interpretation#!", Operand);
10427 Set_Etype (Operand, It1.Typ);
10428 Opnd_Type := It1.Typ;
10434 if Is_Numeric_Type (Target_Type) then
10436 -- A universal fixed expression can be converted to any numeric type
10438 if Opnd_Type = Universal_Fixed then
10441 -- Also no need to check when in an instance or inlined body, because
10442 -- the legality has been established when the template was analyzed.
10443 -- Furthermore, numeric conversions may occur where only a private
10444 -- view of the operand type is visible at the instantiation point.
10445 -- This results in a spurious error if we check that the operand type
10446 -- is a numeric type.
10448 -- Note: in a previous version of this unit, the following tests were
10449 -- applied only for generated code (Comes_From_Source set to False),
10450 -- but in fact the test is required for source code as well, since
10451 -- this situation can arise in source code.
10453 elsif In_Instance or else In_Inlined_Body then
10456 -- Otherwise we need the conversion check
10459 return Conversion_Check
10460 (Is_Numeric_Type (Opnd_Type),
10461 "illegal operand for numeric conversion");
10466 elsif Is_Array_Type (Target_Type) then
10467 if not Is_Array_Type (Opnd_Type)
10468 or else Opnd_Type = Any_Composite
10469 or else Opnd_Type = Any_String
10471 Error_Msg_N ("illegal operand for array conversion", Operand);
10474 return Valid_Array_Conversion;
10477 -- Ada 2005 (AI-251): Anonymous access types where target references an
10480 elsif Ekind_In (Target_Type, E_General_Access_Type,
10481 E_Anonymous_Access_Type)
10482 and then Is_Interface (Directly_Designated_Type (Target_Type))
10484 -- Check the static accessibility rule of 4.6(17). Note that the
10485 -- check is not enforced when within an instance body, since the
10486 -- RM requires such cases to be caught at run time.
10488 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
10489 if Type_Access_Level (Opnd_Type) >
10490 Type_Access_Level (Target_Type)
10492 -- In an instance, this is a run-time check, but one we know
10493 -- will fail, so generate an appropriate warning. The raise
10494 -- will be generated by Expand_N_Type_Conversion.
10496 if In_Instance_Body then
10498 ("?cannot convert local pointer to non-local access type",
10501 ("\?Program_Error will be raised at run time", Operand);
10504 ("cannot convert local pointer to non-local access type",
10509 -- Special accessibility checks are needed in the case of access
10510 -- discriminants declared for a limited type.
10512 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10513 and then not Is_Local_Anonymous_Access (Opnd_Type)
10515 -- When the operand is a selected access discriminant the check
10516 -- needs to be made against the level of the object denoted by
10517 -- the prefix of the selected name (Object_Access_Level handles
10518 -- checking the prefix of the operand for this case).
10520 if Nkind (Operand) = N_Selected_Component
10521 and then Object_Access_Level (Operand) >
10522 Type_Access_Level (Target_Type)
10524 -- In an instance, this is a run-time check, but one we know
10525 -- will fail, so generate an appropriate warning. The raise
10526 -- will be generated by Expand_N_Type_Conversion.
10528 if In_Instance_Body then
10530 ("?cannot convert access discriminant to non-local" &
10531 " access type", Operand);
10533 ("\?Program_Error will be raised at run time", Operand);
10536 ("cannot convert access discriminant to non-local" &
10537 " access type", Operand);
10542 -- The case of a reference to an access discriminant from
10543 -- within a limited type declaration (which will appear as
10544 -- a discriminal) is always illegal because the level of the
10545 -- discriminant is considered to be deeper than any (nameable)
10548 if Is_Entity_Name (Operand)
10549 and then not Is_Local_Anonymous_Access (Opnd_Type)
10551 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10552 and then Present (Discriminal_Link (Entity (Operand)))
10555 ("discriminant has deeper accessibility level than target",
10564 -- General and anonymous access types
10566 elsif Ekind_In (Target_Type, E_General_Access_Type,
10567 E_Anonymous_Access_Type)
10570 (Is_Access_Type (Opnd_Type)
10572 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
10573 E_Access_Protected_Subprogram_Type),
10574 "must be an access-to-object type")
10576 if Is_Access_Constant (Opnd_Type)
10577 and then not Is_Access_Constant (Target_Type)
10580 ("access-to-constant operand type not allowed", Operand);
10584 -- Check the static accessibility rule of 4.6(17). Note that the
10585 -- check is not enforced when within an instance body, since the RM
10586 -- requires such cases to be caught at run time.
10588 if Ekind (Target_Type) /= E_Anonymous_Access_Type
10589 or else Is_Local_Anonymous_Access (Target_Type)
10591 if Type_Access_Level (Opnd_Type)
10592 > Type_Access_Level (Target_Type)
10594 -- In an instance, this is a run-time check, but one we know
10595 -- will fail, so generate an appropriate warning. The raise
10596 -- will be generated by Expand_N_Type_Conversion.
10598 if In_Instance_Body then
10600 ("?cannot convert local pointer to non-local access type",
10603 ("\?Program_Error will be raised at run time", Operand);
10606 -- Avoid generation of spurious error message
10608 if not Error_Posted (N) then
10610 ("cannot convert local pointer to non-local access type",
10617 -- Special accessibility checks are needed in the case of access
10618 -- discriminants declared for a limited type.
10620 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10621 and then not Is_Local_Anonymous_Access (Opnd_Type)
10623 -- When the operand is a selected access discriminant the check
10624 -- needs to be made against the level of the object denoted by
10625 -- the prefix of the selected name (Object_Access_Level handles
10626 -- checking the prefix of the operand for this case).
10628 if Nkind (Operand) = N_Selected_Component
10629 and then Object_Access_Level (Operand) >
10630 Type_Access_Level (Target_Type)
10632 -- In an instance, this is a run-time check, but one we know
10633 -- will fail, so generate an appropriate warning. The raise
10634 -- will be generated by Expand_N_Type_Conversion.
10636 if In_Instance_Body then
10638 ("?cannot convert access discriminant to non-local" &
10639 " access type", Operand);
10641 ("\?Program_Error will be raised at run time",
10646 ("cannot convert access discriminant to non-local" &
10647 " access type", Operand);
10652 -- The case of a reference to an access discriminant from
10653 -- within a limited type declaration (which will appear as
10654 -- a discriminal) is always illegal because the level of the
10655 -- discriminant is considered to be deeper than any (nameable)
10658 if Is_Entity_Name (Operand)
10660 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10661 and then Present (Discriminal_Link (Entity (Operand)))
10664 ("discriminant has deeper accessibility level than target",
10671 -- In the presence of limited_with clauses we have to use non-limited
10672 -- views, if available.
10674 Check_Limited : declare
10675 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
10676 -- Helper function to handle limited views
10678 --------------------------
10679 -- Full_Designated_Type --
10680 --------------------------
10682 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
10683 Desig : constant Entity_Id := Designated_Type (T);
10686 -- Handle the limited view of a type
10688 if Is_Incomplete_Type (Desig)
10689 and then From_With_Type (Desig)
10690 and then Present (Non_Limited_View (Desig))
10692 return Available_View (Desig);
10696 end Full_Designated_Type;
10698 -- Local Declarations
10700 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
10701 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
10703 Same_Base : constant Boolean :=
10704 Base_Type (Target) = Base_Type (Opnd);
10706 -- Start of processing for Check_Limited
10709 if Is_Tagged_Type (Target) then
10710 return Valid_Tagged_Conversion (Target, Opnd);
10713 if not Same_Base then
10715 ("target designated type not compatible with }",
10716 N, Base_Type (Opnd));
10719 -- Ada 2005 AI-384: legality rule is symmetric in both
10720 -- designated types. The conversion is legal (with possible
10721 -- constraint check) if either designated type is
10724 elsif Subtypes_Statically_Match (Target, Opnd)
10726 (Has_Discriminants (Target)
10728 (not Is_Constrained (Opnd)
10729 or else not Is_Constrained (Target)))
10731 -- Special case, if Value_Size has been used to make the
10732 -- sizes different, the conversion is not allowed even
10733 -- though the subtypes statically match.
10735 if Known_Static_RM_Size (Target)
10736 and then Known_Static_RM_Size (Opnd)
10737 and then RM_Size (Target) /= RM_Size (Opnd)
10740 ("target designated subtype not compatible with }",
10743 ("\because sizes of the two designated subtypes differ",
10747 -- Normal case where conversion is allowed
10755 ("target designated subtype not compatible with }",
10762 -- Access to subprogram types. If the operand is an access parameter,
10763 -- the type has a deeper accessibility that any master, and cannot be
10764 -- assigned. We must make an exception if the conversion is part of an
10765 -- assignment and the target is the return object of an extended return
10766 -- statement, because in that case the accessibility check takes place
10767 -- after the return.
10769 elsif Is_Access_Subprogram_Type (Target_Type)
10770 and then No (Corresponding_Remote_Type (Opnd_Type))
10772 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
10773 and then Is_Entity_Name (Operand)
10774 and then Ekind (Entity (Operand)) = E_In_Parameter
10776 (Nkind (Parent (N)) /= N_Assignment_Statement
10777 or else not Is_Entity_Name (Name (Parent (N)))
10778 or else not Is_Return_Object (Entity (Name (Parent (N)))))
10781 ("illegal attempt to store anonymous access to subprogram",
10784 ("\value has deeper accessibility than any master " &
10785 "(RM 3.10.2 (13))",
10789 ("\use named access type for& instead of access parameter",
10790 Operand, Entity (Operand));
10793 -- Check that the designated types are subtype conformant
10795 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
10796 Old_Id => Designated_Type (Opnd_Type),
10799 -- Check the static accessibility rule of 4.6(20)
10801 if Type_Access_Level (Opnd_Type) >
10802 Type_Access_Level (Target_Type)
10805 ("operand type has deeper accessibility level than target",
10808 -- Check that if the operand type is declared in a generic body,
10809 -- then the target type must be declared within that same body
10810 -- (enforces last sentence of 4.6(20)).
10812 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
10814 O_Gen : constant Node_Id :=
10815 Enclosing_Generic_Body (Opnd_Type);
10820 T_Gen := Enclosing_Generic_Body (Target_Type);
10821 while Present (T_Gen) and then T_Gen /= O_Gen loop
10822 T_Gen := Enclosing_Generic_Body (T_Gen);
10825 if T_Gen /= O_Gen then
10827 ("target type must be declared in same generic body"
10828 & " as operand type", N);
10835 -- Remote subprogram access types
10837 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
10838 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
10840 -- It is valid to convert from one RAS type to another provided
10841 -- that their specification statically match.
10843 Check_Subtype_Conformant
10845 Designated_Type (Corresponding_Remote_Type (Target_Type)),
10847 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
10852 -- If both are tagged types, check legality of view conversions
10854 elsif Is_Tagged_Type (Target_Type)
10856 Is_Tagged_Type (Opnd_Type)
10858 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
10860 -- Types derived from the same root type are convertible
10862 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
10865 -- In an instance or an inlined body, there may be inconsistent views of
10866 -- the same type, or of types derived from a common root.
10868 elsif (In_Instance or In_Inlined_Body)
10870 Root_Type (Underlying_Type (Target_Type)) =
10871 Root_Type (Underlying_Type (Opnd_Type))
10875 -- Special check for common access type error case
10877 elsif Ekind (Target_Type) = E_Access_Type
10878 and then Is_Access_Type (Opnd_Type)
10880 Error_Msg_N ("target type must be general access type!", N);
10881 Error_Msg_NE -- CODEFIX
10882 ("add ALL to }!", N, Target_Type);
10886 Error_Msg_NE ("invalid conversion, not compatible with }",
10890 end Valid_Conversion;
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