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;
1693 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1697 if Nkind (Nod) = N_Identifier then
1698 Ent := Entity (Nod);
1701 and then Ekind (Ent) = E_Discriminant
1704 Make_Selected_Component (Loc,
1705 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1706 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1708 Set_Etype (Nod, Etype (Ent));
1716 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1718 -- Start of processing for Replace_Actual_Discriminants
1721 if not Expander_Active then
1725 if Nkind (Name (N)) = N_Selected_Component then
1726 Tsk := Prefix (Name (N));
1728 elsif Nkind (Name (N)) = N_Indexed_Component then
1729 Tsk := Prefix (Prefix (Name (N)));
1735 Replace_Discrs (Default);
1737 end Replace_Actual_Discriminants;
1743 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1744 Ambiguous : Boolean := False;
1745 Ctx_Type : Entity_Id := Typ;
1746 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1747 Err_Type : Entity_Id := Empty;
1748 Found : Boolean := False;
1751 I1 : Interp_Index := 0; -- prevent junk warning
1754 Seen : Entity_Id := Empty; -- prevent junk warning
1756 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1757 -- Determine whether a node comes from a predefined library unit or
1760 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1761 -- Try and fix up a literal so that it matches its expected type. New
1762 -- literals are manufactured if necessary to avoid cascaded errors.
1764 procedure Report_Ambiguous_Argument;
1765 -- Additional diagnostics when an ambiguous call has an ambiguous
1766 -- argument (typically a controlling actual).
1768 procedure Resolution_Failed;
1769 -- Called when attempt at resolving current expression fails
1771 ------------------------------------
1772 -- Comes_From_Predefined_Lib_Unit --
1773 -------------------------------------
1775 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1778 Sloc (Nod) = Standard_Location
1779 or else Is_Predefined_File_Name
1780 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1781 end Comes_From_Predefined_Lib_Unit;
1783 --------------------
1784 -- Patch_Up_Value --
1785 --------------------
1787 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1789 if Nkind (N) = N_Integer_Literal
1790 and then Is_Real_Type (Typ)
1793 Make_Real_Literal (Sloc (N),
1794 Realval => UR_From_Uint (Intval (N))));
1795 Set_Etype (N, Universal_Real);
1796 Set_Is_Static_Expression (N);
1798 elsif Nkind (N) = N_Real_Literal
1799 and then Is_Integer_Type (Typ)
1802 Make_Integer_Literal (Sloc (N),
1803 Intval => UR_To_Uint (Realval (N))));
1804 Set_Etype (N, Universal_Integer);
1805 Set_Is_Static_Expression (N);
1807 elsif Nkind (N) = N_String_Literal
1808 and then Is_Character_Type (Typ)
1810 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1812 Make_Character_Literal (Sloc (N),
1814 Char_Literal_Value =>
1815 UI_From_Int (Character'Pos ('A'))));
1816 Set_Etype (N, Any_Character);
1817 Set_Is_Static_Expression (N);
1819 elsif Nkind (N) /= N_String_Literal
1820 and then Is_String_Type (Typ)
1823 Make_String_Literal (Sloc (N),
1824 Strval => End_String));
1826 elsif Nkind (N) = N_Range then
1827 Patch_Up_Value (Low_Bound (N), Typ);
1828 Patch_Up_Value (High_Bound (N), Typ);
1832 -------------------------------
1833 -- Report_Ambiguous_Argument --
1834 -------------------------------
1836 procedure Report_Ambiguous_Argument is
1837 Arg : constant Node_Id := First (Parameter_Associations (N));
1842 if Nkind (Arg) = N_Function_Call
1843 and then Is_Entity_Name (Name (Arg))
1844 and then Is_Overloaded (Name (Arg))
1846 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1848 -- Could use comments on what is going on here ???
1850 Get_First_Interp (Name (Arg), I, It);
1851 while Present (It.Nam) loop
1852 Error_Msg_Sloc := Sloc (It.Nam);
1854 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1855 Error_Msg_N ("interpretation (inherited) #!", Arg);
1857 Error_Msg_N ("interpretation #!", Arg);
1860 Get_Next_Interp (I, It);
1863 end Report_Ambiguous_Argument;
1865 -----------------------
1866 -- Resolution_Failed --
1867 -----------------------
1869 procedure Resolution_Failed is
1871 Patch_Up_Value (N, Typ);
1873 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1874 Set_Is_Overloaded (N, False);
1876 -- The caller will return without calling the expander, so we need
1877 -- to set the analyzed flag. Note that it is fine to set Analyzed
1878 -- to True even if we are in the middle of a shallow analysis,
1879 -- (see the spec of sem for more details) since this is an error
1880 -- situation anyway, and there is no point in repeating the
1881 -- analysis later (indeed it won't work to repeat it later, since
1882 -- we haven't got a clear resolution of which entity is being
1885 Set_Analyzed (N, True);
1887 end Resolution_Failed;
1889 -- Start of processing for Resolve
1896 -- Access attribute on remote subprogram cannot be used for
1897 -- a non-remote access-to-subprogram type.
1899 if Nkind (N) = N_Attribute_Reference
1900 and then (Attribute_Name (N) = Name_Access or else
1901 Attribute_Name (N) = Name_Unrestricted_Access or else
1902 Attribute_Name (N) = Name_Unchecked_Access)
1903 and then Comes_From_Source (N)
1904 and then Is_Entity_Name (Prefix (N))
1905 and then Is_Subprogram (Entity (Prefix (N)))
1906 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1907 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1910 ("prefix must statically denote a non-remote subprogram", N);
1913 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1915 -- If the context is a Remote_Access_To_Subprogram, access attributes
1916 -- must be resolved with the corresponding fat pointer. There is no need
1917 -- to check for the attribute name since the return type of an
1918 -- attribute is never a remote type.
1920 if Nkind (N) = N_Attribute_Reference
1921 and then Comes_From_Source (N)
1922 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
1925 Attr : constant Attribute_Id :=
1926 Get_Attribute_Id (Attribute_Name (N));
1927 Pref : constant Node_Id := Prefix (N);
1930 Is_Remote : Boolean := True;
1933 -- Check that Typ is a remote access-to-subprogram type
1935 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1937 -- Prefix (N) must statically denote a remote subprogram
1938 -- declared in a package specification.
1940 if Attr = Attribute_Access then
1941 Decl := Unit_Declaration_Node (Entity (Pref));
1943 if Nkind (Decl) = N_Subprogram_Body then
1944 Spec := Corresponding_Spec (Decl);
1946 if not No (Spec) then
1947 Decl := Unit_Declaration_Node (Spec);
1951 Spec := Parent (Decl);
1953 if not Is_Entity_Name (Prefix (N))
1954 or else Nkind (Spec) /= N_Package_Specification
1956 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1960 ("prefix must statically denote a remote subprogram ",
1965 -- If we are generating code for a distributed program.
1966 -- perform semantic checks against the corresponding
1969 if (Attr = Attribute_Access or else
1970 Attr = Attribute_Unchecked_Access or else
1971 Attr = Attribute_Unrestricted_Access)
1972 and then Expander_Active
1973 and then Get_PCS_Name /= Name_No_DSA
1975 Check_Subtype_Conformant
1976 (New_Id => Entity (Prefix (N)),
1977 Old_Id => Designated_Type
1978 (Corresponding_Remote_Type (Typ)),
1982 Process_Remote_AST_Attribute (N, Typ);
1989 Debug_A_Entry ("resolving ", N);
1991 if Comes_From_Source (N) then
1992 if Is_Fixed_Point_Type (Typ) then
1993 Check_Restriction (No_Fixed_Point, N);
1995 elsif Is_Floating_Point_Type (Typ)
1996 and then Typ /= Universal_Real
1997 and then Typ /= Any_Real
1999 Check_Restriction (No_Floating_Point, N);
2003 -- Return if already analyzed
2005 if Analyzed (N) then
2006 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2009 -- Return if type = Any_Type (previous error encountered)
2011 elsif Etype (N) = Any_Type then
2012 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2016 Check_Parameterless_Call (N);
2018 -- If not overloaded, then we know the type, and all that needs doing
2019 -- is to check that this type is compatible with the context.
2021 if not Is_Overloaded (N) then
2022 Found := Covers (Typ, Etype (N));
2023 Expr_Type := Etype (N);
2025 -- In the overloaded case, we must select the interpretation that
2026 -- is compatible with the context (i.e. the type passed to Resolve)
2029 -- Loop through possible interpretations
2031 Get_First_Interp (N, I, It);
2032 Interp_Loop : while Present (It.Typ) loop
2034 -- We are only interested in interpretations that are compatible
2035 -- with the expected type, any other interpretations are ignored.
2037 if not Covers (Typ, It.Typ) then
2038 if Debug_Flag_V then
2039 Write_Str (" interpretation incompatible with context");
2044 -- Skip the current interpretation if it is disabled by an
2045 -- abstract operator. This action is performed only when the
2046 -- type against which we are resolving is the same as the
2047 -- type of the interpretation.
2049 if Ada_Version >= Ada_2005
2050 and then It.Typ = Typ
2051 and then Typ /= Universal_Integer
2052 and then Typ /= Universal_Real
2053 and then Present (It.Abstract_Op)
2058 -- First matching interpretation
2064 Expr_Type := It.Typ;
2066 -- Matching interpretation that is not the first, maybe an
2067 -- error, but there are some cases where preference rules are
2068 -- used to choose between the two possibilities. These and
2069 -- some more obscure cases are handled in Disambiguate.
2072 -- If the current statement is part of a predefined library
2073 -- unit, then all interpretations which come from user level
2074 -- packages should not be considered.
2077 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
2082 Error_Msg_Sloc := Sloc (Seen);
2083 It1 := Disambiguate (N, I1, I, Typ);
2085 -- Disambiguation has succeeded. Skip the remaining
2088 if It1 /= No_Interp then
2090 Expr_Type := It1.Typ;
2092 while Present (It.Typ) loop
2093 Get_Next_Interp (I, It);
2097 -- Before we issue an ambiguity complaint, check for
2098 -- the case of a subprogram call where at least one
2099 -- of the arguments is Any_Type, and if so, suppress
2100 -- the message, since it is a cascaded error.
2102 if Nkind_In (N, N_Function_Call,
2103 N_Procedure_Call_Statement)
2110 A := First_Actual (N);
2111 while Present (A) loop
2114 if Nkind (E) = N_Parameter_Association then
2115 E := Explicit_Actual_Parameter (E);
2118 if Etype (E) = Any_Type then
2119 if Debug_Flag_V then
2120 Write_Str ("Any_Type in call");
2131 elsif Nkind (N) in N_Binary_Op
2132 and then (Etype (Left_Opnd (N)) = Any_Type
2133 or else Etype (Right_Opnd (N)) = Any_Type)
2137 elsif Nkind (N) in N_Unary_Op
2138 and then Etype (Right_Opnd (N)) = Any_Type
2143 -- Not that special case, so issue message using the
2144 -- flag Ambiguous to control printing of the header
2145 -- message only at the start of an ambiguous set.
2147 if not Ambiguous then
2148 if Nkind (N) = N_Function_Call
2149 and then Nkind (Name (N)) = N_Explicit_Dereference
2152 ("ambiguous expression "
2153 & "(cannot resolve indirect call)!", N);
2155 Error_Msg_NE -- CODEFIX
2156 ("ambiguous expression (cannot resolve&)!",
2162 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2164 ("\\possible interpretation (inherited)#!", N);
2166 Error_Msg_N -- CODEFIX
2167 ("\\possible interpretation#!", N);
2171 (N, N_Procedure_Call_Statement, N_Function_Call)
2172 and then Present (Parameter_Associations (N))
2174 Report_Ambiguous_Argument;
2178 Error_Msg_Sloc := Sloc (It.Nam);
2180 -- By default, the error message refers to the candidate
2181 -- interpretation. But if it is a predefined operator, it
2182 -- is implicitly declared at the declaration of the type
2183 -- of the operand. Recover the sloc of that declaration
2184 -- for the error message.
2186 if Nkind (N) in N_Op
2187 and then Scope (It.Nam) = Standard_Standard
2188 and then not Is_Overloaded (Right_Opnd (N))
2189 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2192 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2194 if Comes_From_Source (Err_Type)
2195 and then Present (Parent (Err_Type))
2197 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2200 elsif Nkind (N) in N_Binary_Op
2201 and then Scope (It.Nam) = Standard_Standard
2202 and then not Is_Overloaded (Left_Opnd (N))
2203 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2206 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2208 if Comes_From_Source (Err_Type)
2209 and then Present (Parent (Err_Type))
2211 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2214 -- If this is an indirect call, use the subprogram_type
2215 -- in the message, to have a meaningful location. Also
2216 -- indicate if this is an inherited operation, created
2217 -- by a type declaration.
2219 elsif Nkind (N) = N_Function_Call
2220 and then Nkind (Name (N)) = N_Explicit_Dereference
2221 and then Is_Type (It.Nam)
2225 Sloc (Associated_Node_For_Itype (Err_Type));
2230 if Nkind (N) in N_Op
2231 and then Scope (It.Nam) = Standard_Standard
2232 and then Present (Err_Type)
2234 -- Special-case the message for universal_fixed
2235 -- operators, which are not declared with the type
2236 -- of the operand, but appear forever in Standard.
2238 if It.Typ = Universal_Fixed
2239 and then Scope (It.Nam) = Standard_Standard
2242 ("\\possible interpretation as " &
2243 "universal_fixed operation " &
2244 "(RM 4.5.5 (19))", N);
2247 ("\\possible interpretation (predefined)#!", N);
2251 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2254 ("\\possible interpretation (inherited)#!", N);
2256 Error_Msg_N -- CODEFIX
2257 ("\\possible interpretation#!", N);
2263 -- We have a matching interpretation, Expr_Type is the type
2264 -- from this interpretation, and Seen is the entity.
2266 -- For an operator, just set the entity name. The type will be
2267 -- set by the specific operator resolution routine.
2269 if Nkind (N) in N_Op then
2270 Set_Entity (N, Seen);
2271 Generate_Reference (Seen, N);
2273 elsif Nkind (N) = N_Case_Expression then
2274 Set_Etype (N, Expr_Type);
2276 elsif Nkind (N) = N_Character_Literal then
2277 Set_Etype (N, Expr_Type);
2279 elsif Nkind (N) = N_Conditional_Expression then
2280 Set_Etype (N, Expr_Type);
2282 -- For an explicit dereference, attribute reference, range,
2283 -- short-circuit form (which is not an operator node), or call
2284 -- with a name that is an explicit dereference, there is
2285 -- nothing to be done at this point.
2287 elsif Nkind_In (N, N_Explicit_Dereference,
2288 N_Attribute_Reference,
2290 N_Indexed_Component,
2293 N_Selected_Component,
2295 or else Nkind (Name (N)) = N_Explicit_Dereference
2299 -- For procedure or function calls, set the type of the name,
2300 -- and also the entity pointer for the prefix.
2302 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2303 and then Is_Entity_Name (Name (N))
2305 Set_Etype (Name (N), Expr_Type);
2306 Set_Entity (Name (N), Seen);
2307 Generate_Reference (Seen, Name (N));
2309 elsif Nkind (N) = N_Function_Call
2310 and then Nkind (Name (N)) = N_Selected_Component
2312 Set_Etype (Name (N), Expr_Type);
2313 Set_Entity (Selector_Name (Name (N)), Seen);
2314 Generate_Reference (Seen, Selector_Name (Name (N)));
2316 -- For all other cases, just set the type of the Name
2319 Set_Etype (Name (N), Expr_Type);
2326 -- Move to next interpretation
2328 exit Interp_Loop when No (It.Typ);
2330 Get_Next_Interp (I, It);
2331 end loop Interp_Loop;
2334 -- At this stage Found indicates whether or not an acceptable
2335 -- interpretation exists. If not, then we have an error, except that if
2336 -- the context is Any_Type as a result of some other error, then we
2337 -- suppress the error report.
2340 if Typ /= Any_Type then
2342 -- If type we are looking for is Void, then this is the procedure
2343 -- call case, and the error is simply that what we gave is not a
2344 -- procedure name (we think of procedure calls as expressions with
2345 -- types internally, but the user doesn't think of them this way!)
2347 if Typ = Standard_Void_Type then
2349 -- Special case message if function used as a procedure
2351 if Nkind (N) = N_Procedure_Call_Statement
2352 and then Is_Entity_Name (Name (N))
2353 and then Ekind (Entity (Name (N))) = E_Function
2356 ("cannot use function & in a procedure call",
2357 Name (N), Entity (Name (N)));
2359 -- Otherwise give general message (not clear what cases this
2360 -- covers, but no harm in providing for them!)
2363 Error_Msg_N ("expect procedure name in procedure call", N);
2368 -- Otherwise we do have a subexpression with the wrong type
2370 -- Check for the case of an allocator which uses an access type
2371 -- instead of the designated type. This is a common error and we
2372 -- specialize the message, posting an error on the operand of the
2373 -- allocator, complaining that we expected the designated type of
2376 elsif Nkind (N) = N_Allocator
2377 and then Ekind (Typ) in Access_Kind
2378 and then Ekind (Etype (N)) in Access_Kind
2379 and then Designated_Type (Etype (N)) = Typ
2381 Wrong_Type (Expression (N), Designated_Type (Typ));
2384 -- Check for view mismatch on Null in instances, for which the
2385 -- view-swapping mechanism has no identifier.
2387 elsif (In_Instance or else In_Inlined_Body)
2388 and then (Nkind (N) = N_Null)
2389 and then Is_Private_Type (Typ)
2390 and then Is_Access_Type (Full_View (Typ))
2392 Resolve (N, Full_View (Typ));
2396 -- Check for an aggregate. Sometimes we can get bogus aggregates
2397 -- from misuse of parentheses, and we are about to complain about
2398 -- the aggregate without even looking inside it.
2400 -- Instead, if we have an aggregate of type Any_Composite, then
2401 -- analyze and resolve the component fields, and then only issue
2402 -- another message if we get no errors doing this (otherwise
2403 -- assume that the errors in the aggregate caused the problem).
2405 elsif Nkind (N) = N_Aggregate
2406 and then Etype (N) = Any_Composite
2408 -- Disable expansion in any case. If there is a type mismatch
2409 -- it may be fatal to try to expand the aggregate. The flag
2410 -- would otherwise be set to false when the error is posted.
2412 Expander_Active := False;
2415 procedure Check_Aggr (Aggr : Node_Id);
2416 -- Check one aggregate, and set Found to True if we have a
2417 -- definite error in any of its elements
2419 procedure Check_Elmt (Aelmt : Node_Id);
2420 -- Check one element of aggregate and set Found to True if
2421 -- we definitely have an error in the element.
2427 procedure Check_Aggr (Aggr : Node_Id) is
2431 if Present (Expressions (Aggr)) then
2432 Elmt := First (Expressions (Aggr));
2433 while Present (Elmt) loop
2439 if Present (Component_Associations (Aggr)) then
2440 Elmt := First (Component_Associations (Aggr));
2441 while Present (Elmt) loop
2443 -- If this is a default-initialized component, then
2444 -- there is nothing to check. The box will be
2445 -- replaced by the appropriate call during late
2448 if not Box_Present (Elmt) then
2449 Check_Elmt (Expression (Elmt));
2461 procedure Check_Elmt (Aelmt : Node_Id) is
2463 -- If we have a nested aggregate, go inside it (to
2464 -- attempt a naked analyze-resolve of the aggregate can
2465 -- cause undesirable cascaded errors). Do not resolve
2466 -- expression if it needs a type from context, as for
2467 -- integer * fixed expression.
2469 if Nkind (Aelmt) = N_Aggregate then
2475 if not Is_Overloaded (Aelmt)
2476 and then Etype (Aelmt) /= Any_Fixed
2481 if Etype (Aelmt) = Any_Type then
2492 -- If an error message was issued already, Found got reset to
2493 -- True, so if it is still False, issue standard Wrong_Type msg.
2496 if Is_Overloaded (N)
2497 and then Nkind (N) = N_Function_Call
2500 Subp_Name : Node_Id;
2502 if Is_Entity_Name (Name (N)) then
2503 Subp_Name := Name (N);
2505 elsif Nkind (Name (N)) = N_Selected_Component then
2507 -- Protected operation: retrieve operation name
2509 Subp_Name := Selector_Name (Name (N));
2512 raise Program_Error;
2515 Error_Msg_Node_2 := Typ;
2516 Error_Msg_NE ("no visible interpretation of&" &
2517 " matches expected type&", N, Subp_Name);
2520 if All_Errors_Mode then
2522 Index : Interp_Index;
2526 Error_Msg_N ("\\possible interpretations:", N);
2528 Get_First_Interp (Name (N), Index, It);
2529 while Present (It.Nam) loop
2530 Error_Msg_Sloc := Sloc (It.Nam);
2531 Error_Msg_Node_2 := It.Nam;
2533 ("\\ type& for & declared#", N, It.Typ);
2534 Get_Next_Interp (Index, It);
2539 Error_Msg_N ("\use -gnatf for details", N);
2543 Wrong_Type (N, Typ);
2551 -- Test if we have more than one interpretation for the context
2553 elsif Ambiguous then
2557 -- Here we have an acceptable interpretation for the context
2560 -- Propagate type information and normalize tree for various
2561 -- predefined operations. If the context only imposes a class of
2562 -- types, rather than a specific type, propagate the actual type
2565 if Typ = Any_Integer or else
2566 Typ = Any_Boolean or else
2567 Typ = Any_Modular or else
2568 Typ = Any_Real or else
2571 Ctx_Type := Expr_Type;
2573 -- Any_Fixed is legal in a real context only if a specific fixed-
2574 -- point type is imposed. If Norman Cohen can be confused by this,
2575 -- it deserves a separate message.
2578 and then Expr_Type = Any_Fixed
2580 Error_Msg_N ("illegal context for mixed mode operation", N);
2581 Set_Etype (N, Universal_Real);
2582 Ctx_Type := Universal_Real;
2586 -- A user-defined operator is transformed into a function call at
2587 -- this point, so that further processing knows that operators are
2588 -- really operators (i.e. are predefined operators). User-defined
2589 -- operators that are intrinsic are just renamings of the predefined
2590 -- ones, and need not be turned into calls either, but if they rename
2591 -- a different operator, we must transform the node accordingly.
2592 -- Instantiations of Unchecked_Conversion are intrinsic but are
2593 -- treated as functions, even if given an operator designator.
2595 if Nkind (N) in N_Op
2596 and then Present (Entity (N))
2597 and then Ekind (Entity (N)) /= E_Operator
2600 if not Is_Predefined_Op (Entity (N)) then
2601 Rewrite_Operator_As_Call (N, Entity (N));
2603 elsif Present (Alias (Entity (N)))
2605 Nkind (Parent (Parent (Entity (N)))) =
2606 N_Subprogram_Renaming_Declaration
2608 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2610 -- If the node is rewritten, it will be fully resolved in
2611 -- Rewrite_Renamed_Operator.
2613 if Analyzed (N) then
2619 case N_Subexpr'(Nkind (N)) is
2621 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2623 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2625 when N_Short_Circuit
2626 => Resolve_Short_Circuit (N, Ctx_Type);
2628 when N_Attribute_Reference
2629 => Resolve_Attribute (N, Ctx_Type);
2631 when N_Case_Expression
2632 => Resolve_Case_Expression (N, Ctx_Type);
2634 when N_Character_Literal
2635 => Resolve_Character_Literal (N, Ctx_Type);
2637 when N_Conditional_Expression
2638 => Resolve_Conditional_Expression (N, Ctx_Type);
2640 when N_Expanded_Name
2641 => Resolve_Entity_Name (N, Ctx_Type);
2643 when N_Explicit_Dereference
2644 => Resolve_Explicit_Dereference (N, Ctx_Type);
2646 when N_Expression_With_Actions
2647 => Resolve_Expression_With_Actions (N, Ctx_Type);
2649 when N_Extension_Aggregate
2650 => Resolve_Extension_Aggregate (N, Ctx_Type);
2652 when N_Function_Call
2653 => Resolve_Call (N, Ctx_Type);
2656 => Resolve_Entity_Name (N, Ctx_Type);
2658 when N_Indexed_Component
2659 => Resolve_Indexed_Component (N, Ctx_Type);
2661 when N_Integer_Literal
2662 => Resolve_Integer_Literal (N, Ctx_Type);
2664 when N_Membership_Test
2665 => Resolve_Membership_Op (N, Ctx_Type);
2667 when N_Null => Resolve_Null (N, Ctx_Type);
2669 when N_Op_And | N_Op_Or | N_Op_Xor
2670 => Resolve_Logical_Op (N, Ctx_Type);
2672 when N_Op_Eq | N_Op_Ne
2673 => Resolve_Equality_Op (N, Ctx_Type);
2675 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2676 => Resolve_Comparison_Op (N, Ctx_Type);
2678 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2680 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2681 N_Op_Divide | N_Op_Mod | N_Op_Rem
2683 => Resolve_Arithmetic_Op (N, Ctx_Type);
2685 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2687 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2689 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2690 => Resolve_Unary_Op (N, Ctx_Type);
2692 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2694 when N_Procedure_Call_Statement
2695 => Resolve_Call (N, Ctx_Type);
2697 when N_Operator_Symbol
2698 => Resolve_Operator_Symbol (N, Ctx_Type);
2700 when N_Qualified_Expression
2701 => Resolve_Qualified_Expression (N, Ctx_Type);
2703 when N_Quantified_Expression
2704 => Resolve_Quantified_Expression (N, Ctx_Type);
2706 when N_Raise_xxx_Error
2707 => Set_Etype (N, Ctx_Type);
2709 when N_Range => Resolve_Range (N, Ctx_Type);
2712 => Resolve_Real_Literal (N, Ctx_Type);
2714 when N_Reference => Resolve_Reference (N, Ctx_Type);
2716 when N_Selected_Component
2717 => Resolve_Selected_Component (N, Ctx_Type);
2719 when N_Slice => Resolve_Slice (N, Ctx_Type);
2721 when N_String_Literal
2722 => Resolve_String_Literal (N, Ctx_Type);
2724 when N_Subprogram_Info
2725 => Resolve_Subprogram_Info (N, Ctx_Type);
2727 when N_Type_Conversion
2728 => Resolve_Type_Conversion (N, Ctx_Type);
2730 when N_Unchecked_Expression =>
2731 Resolve_Unchecked_Expression (N, Ctx_Type);
2733 when N_Unchecked_Type_Conversion =>
2734 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2737 -- If the subexpression was replaced by a non-subexpression, then
2738 -- all we do is to expand it. The only legitimate case we know of
2739 -- is converting procedure call statement to entry call statements,
2740 -- but there may be others, so we are making this test general.
2742 if Nkind (N) not in N_Subexpr then
2743 Debug_A_Exit ("resolving ", N, " (done)");
2748 -- AI05-144-2: Check dangerous order dependence within an expression
2749 -- that is not a subexpression. Exclude RHS of an assignment, because
2750 -- both sides may have side-effects and the check must be performed
2751 -- over the statement.
2753 if Nkind (Parent (N)) not in N_Subexpr
2754 and then Nkind (Parent (N)) /= N_Assignment_Statement
2755 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
2757 Check_Order_Dependence;
2760 -- The expression is definitely NOT overloaded at this point, so
2761 -- we reset the Is_Overloaded flag to avoid any confusion when
2762 -- reanalyzing the node.
2764 Set_Is_Overloaded (N, False);
2766 -- Freeze expression type, entity if it is a name, and designated
2767 -- type if it is an allocator (RM 13.14(10,11,13)).
2769 -- Now that the resolution of the type of the node is complete, and
2770 -- we did not detect an error, we can expand this node. We skip the
2771 -- expand call if we are in a default expression, see section
2772 -- "Handling of Default Expressions" in Sem spec.
2774 Debug_A_Exit ("resolving ", N, " (done)");
2776 -- We unconditionally freeze the expression, even if we are in
2777 -- default expression mode (the Freeze_Expression routine tests this
2778 -- flag and only freezes static types if it is set).
2780 Freeze_Expression (N);
2782 -- Now we can do the expansion
2792 -- Version with check(s) suppressed
2794 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2796 if Suppress = All_Checks then
2798 Svg : constant Suppress_Array := Scope_Suppress;
2800 Scope_Suppress := (others => True);
2802 Scope_Suppress := Svg;
2807 Svg : constant Boolean := Scope_Suppress (Suppress);
2809 Scope_Suppress (Suppress) := True;
2811 Scope_Suppress (Suppress) := Svg;
2820 -- Version with implicit type
2822 procedure Resolve (N : Node_Id) is
2824 Resolve (N, Etype (N));
2827 ---------------------
2828 -- Resolve_Actuals --
2829 ---------------------
2831 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2832 Loc : constant Source_Ptr := Sloc (N);
2837 Prev : Node_Id := Empty;
2840 procedure Check_Argument_Order;
2841 -- Performs a check for the case where the actuals are all simple
2842 -- identifiers that correspond to the formal names, but in the wrong
2843 -- order, which is considered suspicious and cause for a warning.
2845 procedure Check_Prefixed_Call;
2846 -- If the original node is an overloaded call in prefix notation,
2847 -- insert an 'Access or a dereference as needed over the first actual.
2848 -- Try_Object_Operation has already verified that there is a valid
2849 -- interpretation, but the form of the actual can only be determined
2850 -- once the primitive operation is identified.
2852 procedure Insert_Default;
2853 -- If the actual is missing in a call, insert in the actuals list
2854 -- an instance of the default expression. The insertion is always
2855 -- a named association.
2857 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2858 -- Check whether T1 and T2, or their full views, are derived from a
2859 -- common type. Used to enforce the restrictions on array conversions
2862 function Static_Concatenation (N : Node_Id) return Boolean;
2863 -- Predicate to determine whether an actual that is a concatenation
2864 -- will be evaluated statically and does not need a transient scope.
2865 -- This must be determined before the actual is resolved and expanded
2866 -- because if needed the transient scope must be introduced earlier.
2868 --------------------------
2869 -- Check_Argument_Order --
2870 --------------------------
2872 procedure Check_Argument_Order is
2874 -- Nothing to do if no parameters, or original node is neither a
2875 -- function call nor a procedure call statement (happens in the
2876 -- operator-transformed-to-function call case), or the call does
2877 -- not come from source, or this warning is off.
2879 if not Warn_On_Parameter_Order
2880 or else No (Parameter_Associations (N))
2881 or else not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2883 or else not Comes_From_Source (N)
2889 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2892 -- Nothing to do if only one parameter
2898 -- Here if at least two arguments
2901 Actuals : array (1 .. Nargs) of Node_Id;
2905 Wrong_Order : Boolean := False;
2906 -- Set True if an out of order case is found
2909 -- Collect identifier names of actuals, fail if any actual is
2910 -- not a simple identifier, and record max length of name.
2912 Actual := First (Parameter_Associations (N));
2913 for J in Actuals'Range loop
2914 if Nkind (Actual) /= N_Identifier then
2917 Actuals (J) := Actual;
2922 -- If we got this far, all actuals are identifiers and the list
2923 -- of their names is stored in the Actuals array.
2925 Formal := First_Formal (Nam);
2926 for J in Actuals'Range loop
2928 -- If we ran out of formals, that's odd, probably an error
2929 -- which will be detected elsewhere, but abandon the search.
2935 -- If name matches and is in order OK
2937 if Chars (Formal) = Chars (Actuals (J)) then
2941 -- If no match, see if it is elsewhere in list and if so
2942 -- flag potential wrong order if type is compatible.
2944 for K in Actuals'Range loop
2945 if Chars (Formal) = Chars (Actuals (K))
2947 Has_Compatible_Type (Actuals (K), Etype (Formal))
2949 Wrong_Order := True;
2959 <<Continue>> Next_Formal (Formal);
2962 -- If Formals left over, also probably an error, skip warning
2964 if Present (Formal) then
2968 -- Here we give the warning if something was out of order
2972 ("actuals for this call may be in wrong order?", N);
2976 end Check_Argument_Order;
2978 -------------------------
2979 -- Check_Prefixed_Call --
2980 -------------------------
2982 procedure Check_Prefixed_Call is
2983 Act : constant Node_Id := First_Actual (N);
2984 A_Type : constant Entity_Id := Etype (Act);
2985 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2986 Orig : constant Node_Id := Original_Node (N);
2990 -- Check whether the call is a prefixed call, with or without
2991 -- additional actuals.
2993 if Nkind (Orig) = N_Selected_Component
2995 (Nkind (Orig) = N_Indexed_Component
2996 and then Nkind (Prefix (Orig)) = N_Selected_Component
2997 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2998 and then Is_Entity_Name (Act)
2999 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3001 if Is_Access_Type (A_Type)
3002 and then not Is_Access_Type (F_Type)
3004 -- Introduce dereference on object in prefix
3007 Make_Explicit_Dereference (Sloc (Act),
3008 Prefix => Relocate_Node (Act));
3009 Rewrite (Act, New_A);
3012 elsif Is_Access_Type (F_Type)
3013 and then not Is_Access_Type (A_Type)
3015 -- Introduce an implicit 'Access in prefix
3017 if not Is_Aliased_View (Act) then
3019 ("object in prefixed call to& must be aliased"
3020 & " (RM-2005 4.3.1 (13))",
3025 Make_Attribute_Reference (Loc,
3026 Attribute_Name => Name_Access,
3027 Prefix => Relocate_Node (Act)));
3032 end Check_Prefixed_Call;
3034 --------------------
3035 -- Insert_Default --
3036 --------------------
3038 procedure Insert_Default is
3043 -- Missing argument in call, nothing to insert
3045 if No (Default_Value (F)) then
3049 -- Note that we do a full New_Copy_Tree, so that any associated
3050 -- Itypes are properly copied. This may not be needed any more,
3051 -- but it does no harm as a safety measure! Defaults of a generic
3052 -- formal may be out of bounds of the corresponding actual (see
3053 -- cc1311b) and an additional check may be required.
3058 New_Scope => Current_Scope,
3061 if Is_Concurrent_Type (Scope (Nam))
3062 and then Has_Discriminants (Scope (Nam))
3064 Replace_Actual_Discriminants (N, Actval);
3067 if Is_Overloadable (Nam)
3068 and then Present (Alias (Nam))
3070 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3071 and then not Is_Tagged_Type (Etype (F))
3073 -- If default is a real literal, do not introduce a
3074 -- conversion whose effect may depend on the run-time
3075 -- size of universal real.
3077 if Nkind (Actval) = N_Real_Literal then
3078 Set_Etype (Actval, Base_Type (Etype (F)));
3080 Actval := Unchecked_Convert_To (Etype (F), Actval);
3084 if Is_Scalar_Type (Etype (F)) then
3085 Enable_Range_Check (Actval);
3088 Set_Parent (Actval, N);
3090 -- Resolve aggregates with their base type, to avoid scope
3091 -- anomalies: the subtype was first built in the subprogram
3092 -- declaration, and the current call may be nested.
3094 if Nkind (Actval) = N_Aggregate then
3095 Analyze_And_Resolve (Actval, Etype (F));
3097 Analyze_And_Resolve (Actval, Etype (Actval));
3101 Set_Parent (Actval, N);
3103 -- See note above concerning aggregates
3105 if Nkind (Actval) = N_Aggregate
3106 and then Has_Discriminants (Etype (Actval))
3108 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3110 -- Resolve entities with their own type, which may differ from
3111 -- the type of a reference in a generic context (the view
3112 -- swapping mechanism did not anticipate the re-analysis of
3113 -- default values in calls).
3115 elsif Is_Entity_Name (Actval) then
3116 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3119 Analyze_And_Resolve (Actval, Etype (Actval));
3123 -- If default is a tag indeterminate function call, propagate tag
3124 -- to obtain proper dispatching.
3126 if Is_Controlling_Formal (F)
3127 and then Nkind (Default_Value (F)) = N_Function_Call
3129 Set_Is_Controlling_Actual (Actval);
3134 -- If the default expression raises constraint error, then just
3135 -- silently replace it with an N_Raise_Constraint_Error node, since
3136 -- we already gave the warning on the subprogram spec. If node is
3137 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3138 -- the warnings removal machinery.
3140 if Raises_Constraint_Error (Actval)
3141 and then Nkind (Actval) /= N_Raise_Constraint_Error
3144 Make_Raise_Constraint_Error (Loc,
3145 Reason => CE_Range_Check_Failed));
3146 Set_Raises_Constraint_Error (Actval);
3147 Set_Etype (Actval, Etype (F));
3151 Make_Parameter_Association (Loc,
3152 Explicit_Actual_Parameter => Actval,
3153 Selector_Name => Make_Identifier (Loc, Chars (F)));
3155 -- Case of insertion is first named actual
3157 if No (Prev) or else
3158 Nkind (Parent (Prev)) /= N_Parameter_Association
3160 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3161 Set_First_Named_Actual (N, Actval);
3164 if No (Parameter_Associations (N)) then
3165 Set_Parameter_Associations (N, New_List (Assoc));
3167 Append (Assoc, Parameter_Associations (N));
3171 Insert_After (Prev, Assoc);
3174 -- Case of insertion is not first named actual
3177 Set_Next_Named_Actual
3178 (Assoc, Next_Named_Actual (Parent (Prev)));
3179 Set_Next_Named_Actual (Parent (Prev), Actval);
3180 Append (Assoc, Parameter_Associations (N));
3183 Mark_Rewrite_Insertion (Assoc);
3184 Mark_Rewrite_Insertion (Actval);
3193 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3194 FT1 : Entity_Id := T1;
3195 FT2 : Entity_Id := T2;
3198 if Is_Private_Type (T1)
3199 and then Present (Full_View (T1))
3201 FT1 := Full_View (T1);
3204 if Is_Private_Type (T2)
3205 and then Present (Full_View (T2))
3207 FT2 := Full_View (T2);
3210 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3213 --------------------------
3214 -- Static_Concatenation --
3215 --------------------------
3217 function Static_Concatenation (N : Node_Id) return Boolean is
3220 when N_String_Literal =>
3225 -- Concatenation is static when both operands are static and
3226 -- the concatenation operator is a predefined one.
3228 return Scope (Entity (N)) = Standard_Standard
3230 Static_Concatenation (Left_Opnd (N))
3232 Static_Concatenation (Right_Opnd (N));
3235 if Is_Entity_Name (N) then
3237 Ent : constant Entity_Id := Entity (N);
3239 return Ekind (Ent) = E_Constant
3240 and then Present (Constant_Value (Ent))
3242 Is_Static_Expression (Constant_Value (Ent));
3249 end Static_Concatenation;
3251 -- Start of processing for Resolve_Actuals
3254 Check_Argument_Order;
3256 if Present (First_Actual (N)) then
3257 Check_Prefixed_Call;
3260 A := First_Actual (N);
3261 F := First_Formal (Nam);
3262 while Present (F) loop
3263 if No (A) and then Needs_No_Actuals (Nam) then
3266 -- If we have an error in any actual or formal, indicated by a type
3267 -- of Any_Type, then abandon resolution attempt, and set result type
3270 elsif (Present (A) and then Etype (A) = Any_Type)
3271 or else Etype (F) = Any_Type
3273 Set_Etype (N, Any_Type);
3277 -- Case where actual is present
3279 -- If the actual is an entity, generate a reference to it now. We
3280 -- do this before the actual is resolved, because a formal of some
3281 -- protected subprogram, or a task discriminant, will be rewritten
3282 -- during expansion, and the source entity reference may be lost.
3285 and then Is_Entity_Name (A)
3286 and then Comes_From_Source (N)
3288 Orig_A := Entity (A);
3290 if Present (Orig_A) then
3291 if Is_Formal (Orig_A)
3292 and then Ekind (F) /= E_In_Parameter
3294 Generate_Reference (Orig_A, A, 'm');
3296 elsif not Is_Overloaded (A) then
3297 Generate_Reference (Orig_A, A);
3303 and then (Nkind (Parent (A)) /= N_Parameter_Association
3304 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3306 -- If style checking mode on, check match of formal name
3309 if Nkind (Parent (A)) = N_Parameter_Association then
3310 Check_Identifier (Selector_Name (Parent (A)), F);
3314 -- If the formal is Out or In_Out, do not resolve and expand the
3315 -- conversion, because it is subsequently expanded into explicit
3316 -- temporaries and assignments. However, the object of the
3317 -- conversion can be resolved. An exception is the case of tagged
3318 -- type conversion with a class-wide actual. In that case we want
3319 -- the tag check to occur and no temporary will be needed (no
3320 -- representation change can occur) and the parameter is passed by
3321 -- reference, so we go ahead and resolve the type conversion.
3322 -- Another exception is the case of reference to component or
3323 -- subcomponent of a bit-packed array, in which case we want to
3324 -- defer expansion to the point the in and out assignments are
3327 if Ekind (F) /= E_In_Parameter
3328 and then Nkind (A) = N_Type_Conversion
3329 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3331 if Ekind (F) = E_In_Out_Parameter
3332 and then Is_Array_Type (Etype (F))
3334 -- In a view conversion, the conversion must be legal in
3335 -- both directions, and thus both component types must be
3336 -- aliased, or neither (4.6 (8)).
3338 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3339 -- the privacy requirement should not apply to generic
3340 -- types, and should be checked in an instance. ARG query
3343 if Has_Aliased_Components (Etype (Expression (A))) /=
3344 Has_Aliased_Components (Etype (F))
3347 ("both component types in a view conversion must be"
3348 & " aliased, or neither", A);
3350 -- Comment here??? what set of cases???
3353 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3355 -- Check view conv between unrelated by ref array types
3357 if Is_By_Reference_Type (Etype (F))
3358 or else Is_By_Reference_Type (Etype (Expression (A)))
3361 ("view conversion between unrelated by reference " &
3362 "array types not allowed (\'A'I-00246)", A);
3364 -- In Ada 2005 mode, check view conversion component
3365 -- type cannot be private, tagged, or volatile. Note
3366 -- that we only apply this to source conversions. The
3367 -- generated code can contain conversions which are
3368 -- not subject to this test, and we cannot extract the
3369 -- component type in such cases since it is not present.
3371 elsif Comes_From_Source (A)
3372 and then Ada_Version >= Ada_2005
3375 Comp_Type : constant Entity_Id :=
3377 (Etype (Expression (A)));
3379 if (Is_Private_Type (Comp_Type)
3380 and then not Is_Generic_Type (Comp_Type))
3381 or else Is_Tagged_Type (Comp_Type)
3382 or else Is_Volatile (Comp_Type)
3385 ("component type of a view conversion cannot"
3386 & " be private, tagged, or volatile"
3395 -- Resolve expression if conversion is all OK
3397 if (Conversion_OK (A)
3398 or else Valid_Conversion (A, Etype (A), Expression (A)))
3399 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3401 Resolve (Expression (A));
3404 -- If the actual is a function call that returns a limited
3405 -- unconstrained object that needs finalization, create a
3406 -- transient scope for it, so that it can receive the proper
3407 -- finalization list.
3409 elsif Nkind (A) = N_Function_Call
3410 and then Is_Limited_Record (Etype (F))
3411 and then not Is_Constrained (Etype (F))
3412 and then Expander_Active
3413 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3415 Establish_Transient_Scope (A, False);
3417 -- A small optimization: if one of the actuals is a concatenation
3418 -- create a block around a procedure call to recover stack space.
3419 -- This alleviates stack usage when several procedure calls in
3420 -- the same statement list use concatenation. We do not perform
3421 -- this wrapping for code statements, where the argument is a
3422 -- static string, and we want to preserve warnings involving
3423 -- sequences of such statements.
3425 elsif Nkind (A) = N_Op_Concat
3426 and then Nkind (N) = N_Procedure_Call_Statement
3427 and then Expander_Active
3429 not (Is_Intrinsic_Subprogram (Nam)
3430 and then Chars (Nam) = Name_Asm)
3431 and then not Static_Concatenation (A)
3433 Establish_Transient_Scope (A, False);
3434 Resolve (A, Etype (F));
3437 if Nkind (A) = N_Type_Conversion
3438 and then Is_Array_Type (Etype (F))
3439 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3441 (Is_Limited_Type (Etype (F))
3442 or else Is_Limited_Type (Etype (Expression (A))))
3445 ("conversion between unrelated limited array types " &
3446 "not allowed (\A\I-00246)", A);
3448 if Is_Limited_Type (Etype (F)) then
3449 Explain_Limited_Type (Etype (F), A);
3452 if Is_Limited_Type (Etype (Expression (A))) then
3453 Explain_Limited_Type (Etype (Expression (A)), A);
3457 -- (Ada 2005: AI-251): If the actual is an allocator whose
3458 -- directly designated type is a class-wide interface, we build
3459 -- an anonymous access type to use it as the type of the
3460 -- allocator. Later, when the subprogram call is expanded, if
3461 -- the interface has a secondary dispatch table the expander
3462 -- will add a type conversion to force the correct displacement
3465 if Nkind (A) = N_Allocator then
3467 DDT : constant Entity_Id :=
3468 Directly_Designated_Type (Base_Type (Etype (F)));
3470 New_Itype : Entity_Id;
3473 if Is_Class_Wide_Type (DDT)
3474 and then Is_Interface (DDT)
3476 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3477 Set_Etype (New_Itype, Etype (A));
3478 Set_Directly_Designated_Type (New_Itype,
3479 Directly_Designated_Type (Etype (A)));
3480 Set_Etype (A, New_Itype);
3483 -- Ada 2005, AI-162:If the actual is an allocator, the
3484 -- innermost enclosing statement is the master of the
3485 -- created object. This needs to be done with expansion
3486 -- enabled only, otherwise the transient scope will not
3487 -- be removed in the expansion of the wrapped construct.
3489 if (Is_Controlled (DDT) or else Has_Task (DDT))
3490 and then Expander_Active
3492 Establish_Transient_Scope (A, False);
3497 -- (Ada 2005): The call may be to a primitive operation of
3498 -- a tagged synchronized type, declared outside of the type.
3499 -- In this case the controlling actual must be converted to
3500 -- its corresponding record type, which is the formal type.
3501 -- The actual may be a subtype, either because of a constraint
3502 -- or because it is a generic actual, so use base type to
3503 -- locate concurrent type.
3505 F_Typ := Base_Type (Etype (F));
3507 if Is_Tagged_Type (F_Typ)
3508 and then (Is_Concurrent_Type (F_Typ)
3509 or else Is_Concurrent_Record_Type (F_Typ))
3511 -- If the actual is overloaded, look for an interpretation
3512 -- that has a synchronized type.
3514 if not Is_Overloaded (A) then
3515 A_Typ := Base_Type (Etype (A));
3519 Index : Interp_Index;
3523 Get_First_Interp (A, Index, It);
3524 while Present (It.Typ) loop
3525 if Is_Concurrent_Type (It.Typ)
3526 or else Is_Concurrent_Record_Type (It.Typ)
3528 A_Typ := Base_Type (It.Typ);
3532 Get_Next_Interp (Index, It);
3538 Full_A_Typ : Entity_Id;
3541 if Present (Full_View (A_Typ)) then
3542 Full_A_Typ := Base_Type (Full_View (A_Typ));
3544 Full_A_Typ := A_Typ;
3547 -- Tagged synchronized type (case 1): the actual is a
3550 if Is_Concurrent_Type (A_Typ)
3551 and then Corresponding_Record_Type (A_Typ) = F_Typ
3554 Unchecked_Convert_To
3555 (Corresponding_Record_Type (A_Typ), A));
3556 Resolve (A, Etype (F));
3558 -- Tagged synchronized type (case 2): the formal is a
3561 elsif Ekind (Full_A_Typ) = E_Record_Type
3563 (Corresponding_Concurrent_Type (Full_A_Typ))
3564 and then Is_Concurrent_Type (F_Typ)
3565 and then Present (Corresponding_Record_Type (F_Typ))
3566 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3568 Resolve (A, Corresponding_Record_Type (F_Typ));
3573 Resolve (A, Etype (F));
3578 -- not a synchronized operation.
3580 Resolve (A, Etype (F));
3587 if Comes_From_Source (Original_Node (N))
3588 and then Nkind_In (Original_Node (N), N_Function_Call,
3589 N_Procedure_Call_Statement)
3591 -- In formal mode, check that actual parameters matching
3592 -- formals of tagged types are objects (or ancestor type
3593 -- conversions of objects), not general expressions.
3595 if Is_Actual_Tagged_Parameter (A) then
3596 if Is_SPARK_Object_Reference (A) then
3599 elsif Nkind (A) = N_Type_Conversion then
3601 Operand : constant Node_Id := Expression (A);
3602 Operand_Typ : constant Entity_Id := Etype (Operand);
3603 Target_Typ : constant Entity_Id := A_Typ;
3606 if not Is_SPARK_Object_Reference (Operand) then
3607 Check_SPARK_Restriction
3608 ("object required", Operand);
3610 -- In formal mode, the only view conversions are those
3611 -- involving ancestor conversion of an extended type.
3614 (Is_Tagged_Type (Target_Typ)
3615 and then not Is_Class_Wide_Type (Target_Typ)
3616 and then Is_Tagged_Type (Operand_Typ)
3617 and then not Is_Class_Wide_Type (Operand_Typ)
3618 and then Is_Ancestor (Target_Typ, Operand_Typ))
3621 (F, E_Out_Parameter, E_In_Out_Parameter)
3623 Check_SPARK_Restriction
3624 ("ancestor conversion is the only permitted "
3625 & "view conversion", A);
3627 Check_SPARK_Restriction
3628 ("ancestor conversion required", A);
3637 Check_SPARK_Restriction ("object required", A);
3640 -- In formal mode, the only view conversions are those
3641 -- involving ancestor conversion of an extended type.
3643 elsif Nkind (A) = N_Type_Conversion
3644 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3646 Check_SPARK_Restriction
3647 ("ancestor conversion is the only permitted view "
3652 -- Save actual for subsequent check on order dependence, and
3653 -- indicate whether actual is modifiable. For AI05-0144-2.
3655 Save_Actual (A, Ekind (F) /= E_In_Parameter);
3657 -- For mode IN, if actual is an entity, and the type of the formal
3658 -- has warnings suppressed, then we reset Never_Set_In_Source for
3659 -- the calling entity. The reason for this is to catch cases like
3660 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3661 -- uses trickery to modify an IN parameter.
3663 if Ekind (F) = E_In_Parameter
3664 and then Is_Entity_Name (A)
3665 and then Present (Entity (A))
3666 and then Ekind (Entity (A)) = E_Variable
3667 and then Has_Warnings_Off (F_Typ)
3669 Set_Never_Set_In_Source (Entity (A), False);
3672 -- Perform error checks for IN and IN OUT parameters
3674 if Ekind (F) /= E_Out_Parameter then
3676 -- Check unset reference. For scalar parameters, it is clearly
3677 -- wrong to pass an uninitialized value as either an IN or
3678 -- IN-OUT parameter. For composites, it is also clearly an
3679 -- error to pass a completely uninitialized value as an IN
3680 -- parameter, but the case of IN OUT is trickier. We prefer
3681 -- not to give a warning here. For example, suppose there is
3682 -- a routine that sets some component of a record to False.
3683 -- It is perfectly reasonable to make this IN-OUT and allow
3684 -- either initialized or uninitialized records to be passed
3687 -- For partially initialized composite values, we also avoid
3688 -- warnings, since it is quite likely that we are passing a
3689 -- partially initialized value and only the initialized fields
3690 -- will in fact be read in the subprogram.
3692 if Is_Scalar_Type (A_Typ)
3693 or else (Ekind (F) = E_In_Parameter
3694 and then not Is_Partially_Initialized_Type (A_Typ))
3696 Check_Unset_Reference (A);
3699 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3700 -- actual to a nested call, since this is case of reading an
3701 -- out parameter, which is not allowed.
3703 if Ada_Version = Ada_83
3704 and then Is_Entity_Name (A)
3705 and then Ekind (Entity (A)) = E_Out_Parameter
3707 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3711 -- Case of OUT or IN OUT parameter
3713 if Ekind (F) /= E_In_Parameter then
3715 -- For an Out parameter, check for useless assignment. Note
3716 -- that we can't set Last_Assignment this early, because we may
3717 -- kill current values in Resolve_Call, and that call would
3718 -- clobber the Last_Assignment field.
3720 -- Note: call Warn_On_Useless_Assignment before doing the check
3721 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3722 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3723 -- reflects the last assignment, not this one!
3725 if Ekind (F) = E_Out_Parameter then
3726 if Warn_On_Modified_As_Out_Parameter (F)
3727 and then Is_Entity_Name (A)
3728 and then Present (Entity (A))
3729 and then Comes_From_Source (N)
3731 Warn_On_Useless_Assignment (Entity (A), A);
3735 -- Validate the form of the actual. Note that the call to
3736 -- Is_OK_Variable_For_Out_Formal generates the required
3737 -- reference in this case.
3739 if not Is_OK_Variable_For_Out_Formal (A) then
3740 Error_Msg_NE ("actual for& must be a variable", A, F);
3743 -- What's the following about???
3745 if Is_Entity_Name (A) then
3746 Kill_Checks (Entity (A));
3752 if Etype (A) = Any_Type then
3753 Set_Etype (N, Any_Type);
3757 -- Apply appropriate range checks for in, out, and in-out
3758 -- parameters. Out and in-out parameters also need a separate
3759 -- check, if there is a type conversion, to make sure the return
3760 -- value meets the constraints of the variable before the
3763 -- Gigi looks at the check flag and uses the appropriate types.
3764 -- For now since one flag is used there is an optimization which
3765 -- might not be done in the In Out case since Gigi does not do
3766 -- any analysis. More thought required about this ???
3768 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
3770 -- Apply predicate checks, unless this is a call to the
3771 -- predicate check function itself, which would cause an
3772 -- infinite recursion.
3774 if not (Ekind (Nam) = E_Function
3775 and then Has_Predicates (Nam))
3777 Apply_Predicate_Check (A, F_Typ);
3780 -- Apply required constraint checks
3782 if Is_Scalar_Type (Etype (A)) then
3783 Apply_Scalar_Range_Check (A, F_Typ);
3785 elsif Is_Array_Type (Etype (A)) then
3786 Apply_Length_Check (A, F_Typ);
3788 elsif Is_Record_Type (F_Typ)
3789 and then Has_Discriminants (F_Typ)
3790 and then Is_Constrained (F_Typ)
3791 and then (not Is_Derived_Type (F_Typ)
3792 or else Comes_From_Source (Nam))
3794 Apply_Discriminant_Check (A, F_Typ);
3796 elsif Is_Access_Type (F_Typ)
3797 and then Is_Array_Type (Designated_Type (F_Typ))
3798 and then Is_Constrained (Designated_Type (F_Typ))
3800 Apply_Length_Check (A, F_Typ);
3802 elsif Is_Access_Type (F_Typ)
3803 and then Has_Discriminants (Designated_Type (F_Typ))
3804 and then Is_Constrained (Designated_Type (F_Typ))
3806 Apply_Discriminant_Check (A, F_Typ);
3809 Apply_Range_Check (A, F_Typ);
3812 -- Ada 2005 (AI-231): Note that the controlling parameter case
3813 -- already existed in Ada 95, which is partially checked
3814 -- elsewhere (see Checks), and we don't want the warning
3815 -- message to differ.
3817 if Is_Access_Type (F_Typ)
3818 and then Can_Never_Be_Null (F_Typ)
3819 and then Known_Null (A)
3821 if Is_Controlling_Formal (F) then
3822 Apply_Compile_Time_Constraint_Error
3824 Msg => "null value not allowed here?",
3825 Reason => CE_Access_Check_Failed);
3827 elsif Ada_Version >= Ada_2005 then
3828 Apply_Compile_Time_Constraint_Error
3830 Msg => "(Ada 2005) null not allowed in "
3831 & "null-excluding formal?",
3832 Reason => CE_Null_Not_Allowed);
3837 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
3838 if Nkind (A) = N_Type_Conversion then
3839 if Is_Scalar_Type (A_Typ) then
3840 Apply_Scalar_Range_Check
3841 (Expression (A), Etype (Expression (A)), A_Typ);
3844 (Expression (A), Etype (Expression (A)), A_Typ);
3848 if Is_Scalar_Type (F_Typ) then
3849 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3850 elsif Is_Array_Type (F_Typ)
3851 and then Ekind (F) = E_Out_Parameter
3853 Apply_Length_Check (A, F_Typ);
3855 Apply_Range_Check (A, A_Typ, F_Typ);
3860 -- An actual associated with an access parameter is implicitly
3861 -- converted to the anonymous access type of the formal and must
3862 -- satisfy the legality checks for access conversions.
3864 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3865 if not Valid_Conversion (A, F_Typ, A) then
3867 ("invalid implicit conversion for access parameter", A);
3871 -- Check bad case of atomic/volatile argument (RM C.6(12))
3873 if Is_By_Reference_Type (Etype (F))
3874 and then Comes_From_Source (N)
3876 if Is_Atomic_Object (A)
3877 and then not Is_Atomic (Etype (F))
3880 ("cannot pass atomic argument to non-atomic formal",
3883 elsif Is_Volatile_Object (A)
3884 and then not Is_Volatile (Etype (F))
3887 ("cannot pass volatile argument to non-volatile formal",
3892 -- Check that subprograms don't have improper controlling
3893 -- arguments (RM 3.9.2 (9)).
3895 -- A primitive operation may have an access parameter of an
3896 -- incomplete tagged type, but a dispatching call is illegal
3897 -- if the type is still incomplete.
3899 if Is_Controlling_Formal (F) then
3900 Set_Is_Controlling_Actual (A);
3902 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3904 Desig : constant Entity_Id := Designated_Type (Etype (F));
3906 if Ekind (Desig) = E_Incomplete_Type
3907 and then No (Full_View (Desig))
3908 and then No (Non_Limited_View (Desig))
3911 ("premature use of incomplete type& " &
3912 "in dispatching call", A, Desig);
3917 elsif Nkind (A) = N_Explicit_Dereference then
3918 Validate_Remote_Access_To_Class_Wide_Type (A);
3921 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3922 and then not Is_Class_Wide_Type (F_Typ)
3923 and then not Is_Controlling_Formal (F)
3925 Error_Msg_N ("class-wide argument not allowed here!", A);
3927 if Is_Subprogram (Nam)
3928 and then Comes_From_Source (Nam)
3930 Error_Msg_Node_2 := F_Typ;
3932 ("& is not a dispatching operation of &!", A, Nam);
3935 elsif Is_Access_Type (A_Typ)
3936 and then Is_Access_Type (F_Typ)
3937 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3938 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3939 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3940 or else (Nkind (A) = N_Attribute_Reference
3942 Is_Class_Wide_Type (Etype (Prefix (A)))))
3943 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3944 and then not Is_Controlling_Formal (F)
3946 -- Disable these checks for call to imported C++ subprograms
3949 (Is_Entity_Name (Name (N))
3950 and then Is_Imported (Entity (Name (N)))
3951 and then Convention (Entity (Name (N))) = Convention_CPP)
3954 ("access to class-wide argument not allowed here!", A);
3956 if Is_Subprogram (Nam)
3957 and then Comes_From_Source (Nam)
3959 Error_Msg_Node_2 := Designated_Type (F_Typ);
3961 ("& is not a dispatching operation of &!", A, Nam);
3967 -- If it is a named association, treat the selector_name as a
3968 -- proper identifier, and mark the corresponding entity.
3970 if Nkind (Parent (A)) = N_Parameter_Association then
3971 Set_Entity (Selector_Name (Parent (A)), F);
3972 Generate_Reference (F, Selector_Name (Parent (A)));
3973 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3974 Generate_Reference (F_Typ, N, ' ');
3979 if Ekind (F) /= E_Out_Parameter then
3980 Check_Unset_Reference (A);
3985 -- Case where actual is not present
3993 end Resolve_Actuals;
3995 -----------------------
3996 -- Resolve_Allocator --
3997 -----------------------
3999 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4000 E : constant Node_Id := Expression (N);
4002 Discrim : Entity_Id;
4005 Assoc : Node_Id := Empty;
4008 procedure Check_Allocator_Discrim_Accessibility
4009 (Disc_Exp : Node_Id;
4010 Alloc_Typ : Entity_Id);
4011 -- Check that accessibility level associated with an access discriminant
4012 -- initialized in an allocator by the expression Disc_Exp is not deeper
4013 -- than the level of the allocator type Alloc_Typ. An error message is
4014 -- issued if this condition is violated. Specialized checks are done for
4015 -- the cases of a constraint expression which is an access attribute or
4016 -- an access discriminant.
4018 function In_Dispatching_Context return Boolean;
4019 -- If the allocator is an actual in a call, it is allowed to be class-
4020 -- wide when the context is not because it is a controlling actual.
4022 -------------------------------------------
4023 -- Check_Allocator_Discrim_Accessibility --
4024 -------------------------------------------
4026 procedure Check_Allocator_Discrim_Accessibility
4027 (Disc_Exp : Node_Id;
4028 Alloc_Typ : Entity_Id)
4031 if Type_Access_Level (Etype (Disc_Exp)) >
4032 Type_Access_Level (Alloc_Typ)
4035 ("operand type has deeper level than allocator type", Disc_Exp);
4037 -- When the expression is an Access attribute the level of the prefix
4038 -- object must not be deeper than that of the allocator's type.
4040 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4041 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
4043 and then Object_Access_Level (Prefix (Disc_Exp))
4044 > Type_Access_Level (Alloc_Typ)
4047 ("prefix of attribute has deeper level than allocator type",
4050 -- When the expression is an access discriminant the check is against
4051 -- the level of the prefix object.
4053 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4054 and then Nkind (Disc_Exp) = N_Selected_Component
4055 and then Object_Access_Level (Prefix (Disc_Exp))
4056 > Type_Access_Level (Alloc_Typ)
4059 ("access discriminant has deeper level than allocator type",
4062 -- All other cases are legal
4067 end Check_Allocator_Discrim_Accessibility;
4069 ----------------------------
4070 -- In_Dispatching_Context --
4071 ----------------------------
4073 function In_Dispatching_Context return Boolean is
4074 Par : constant Node_Id := Parent (N);
4078 Nkind_In (Par, N_Function_Call,
4079 N_Procedure_Call_Statement)
4080 and then Is_Entity_Name (Name (Par))
4081 and then Is_Dispatching_Operation (Entity (Name (Par)));
4082 end In_Dispatching_Context;
4084 -- Start of processing for Resolve_Allocator
4087 -- Replace general access with specific type
4089 if Ekind (Etype (N)) = E_Allocator_Type then
4090 Set_Etype (N, Base_Type (Typ));
4093 if Is_Abstract_Type (Typ) then
4094 Error_Msg_N ("type of allocator cannot be abstract", N);
4097 -- For qualified expression, resolve the expression using the
4098 -- given subtype (nothing to do for type mark, subtype indication)
4100 if Nkind (E) = N_Qualified_Expression then
4101 if Is_Class_Wide_Type (Etype (E))
4102 and then not Is_Class_Wide_Type (Designated_Type (Typ))
4103 and then not In_Dispatching_Context
4106 ("class-wide allocator not allowed for this access type", N);
4109 Resolve (Expression (E), Etype (E));
4110 Check_Unset_Reference (Expression (E));
4112 -- A qualified expression requires an exact match of the type,
4113 -- class-wide matching is not allowed.
4115 if (Is_Class_Wide_Type (Etype (Expression (E)))
4116 or else Is_Class_Wide_Type (Etype (E)))
4117 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4119 Wrong_Type (Expression (E), Etype (E));
4122 -- A special accessibility check is needed for allocators that
4123 -- constrain access discriminants. The level of the type of the
4124 -- expression used to constrain an access discriminant cannot be
4125 -- deeper than the type of the allocator (in contrast to access
4126 -- parameters, where the level of the actual can be arbitrary).
4128 -- We can't use Valid_Conversion to perform this check because
4129 -- in general the type of the allocator is unrelated to the type
4130 -- of the access discriminant.
4132 if Ekind (Typ) /= E_Anonymous_Access_Type
4133 or else Is_Local_Anonymous_Access (Typ)
4135 Subtyp := Entity (Subtype_Mark (E));
4137 Aggr := Original_Node (Expression (E));
4139 if Has_Discriminants (Subtyp)
4140 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4142 Discrim := First_Discriminant (Base_Type (Subtyp));
4144 -- Get the first component expression of the aggregate
4146 if Present (Expressions (Aggr)) then
4147 Disc_Exp := First (Expressions (Aggr));
4149 elsif Present (Component_Associations (Aggr)) then
4150 Assoc := First (Component_Associations (Aggr));
4152 if Present (Assoc) then
4153 Disc_Exp := Expression (Assoc);
4162 while Present (Discrim) and then Present (Disc_Exp) loop
4163 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4164 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4167 Next_Discriminant (Discrim);
4169 if Present (Discrim) then
4170 if Present (Assoc) then
4172 Disc_Exp := Expression (Assoc);
4174 elsif Present (Next (Disc_Exp)) then
4178 Assoc := First (Component_Associations (Aggr));
4180 if Present (Assoc) then
4181 Disc_Exp := Expression (Assoc);
4191 -- For a subtype mark or subtype indication, freeze the subtype
4194 Freeze_Expression (E);
4196 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4198 ("initialization required for access-to-constant allocator", N);
4201 -- A special accessibility check is needed for allocators that
4202 -- constrain access discriminants. The level of the type of the
4203 -- expression used to constrain an access discriminant cannot be
4204 -- deeper than the type of the allocator (in contrast to access
4205 -- parameters, where the level of the actual can be arbitrary).
4206 -- We can't use Valid_Conversion to perform this check because
4207 -- in general the type of the allocator is unrelated to the type
4208 -- of the access discriminant.
4210 if Nkind (Original_Node (E)) = N_Subtype_Indication
4211 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4212 or else Is_Local_Anonymous_Access (Typ))
4214 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4216 if Has_Discriminants (Subtyp) then
4217 Discrim := First_Discriminant (Base_Type (Subtyp));
4218 Constr := First (Constraints (Constraint (Original_Node (E))));
4219 while Present (Discrim) and then Present (Constr) loop
4220 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4221 if Nkind (Constr) = N_Discriminant_Association then
4222 Disc_Exp := Original_Node (Expression (Constr));
4224 Disc_Exp := Original_Node (Constr);
4227 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4230 Next_Discriminant (Discrim);
4237 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4238 -- check that the level of the type of the created object is not deeper
4239 -- than the level of the allocator's access type, since extensions can
4240 -- now occur at deeper levels than their ancestor types. This is a
4241 -- static accessibility level check; a run-time check is also needed in
4242 -- the case of an initialized allocator with a class-wide argument (see
4243 -- Expand_Allocator_Expression).
4245 if Ada_Version >= Ada_2005
4246 and then Is_Class_Wide_Type (Designated_Type (Typ))
4249 Exp_Typ : Entity_Id;
4252 if Nkind (E) = N_Qualified_Expression then
4253 Exp_Typ := Etype (E);
4254 elsif Nkind (E) = N_Subtype_Indication then
4255 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4257 Exp_Typ := Entity (E);
4260 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4261 if In_Instance_Body then
4262 Error_Msg_N ("?type in allocator has deeper level than" &
4263 " designated class-wide type", E);
4264 Error_Msg_N ("\?Program_Error will be raised at run time",
4267 Make_Raise_Program_Error (Sloc (N),
4268 Reason => PE_Accessibility_Check_Failed));
4271 -- Do not apply Ada 2005 accessibility checks on a class-wide
4272 -- allocator if the type given in the allocator is a formal
4273 -- type. A run-time check will be performed in the instance.
4275 elsif not Is_Generic_Type (Exp_Typ) then
4276 Error_Msg_N ("type in allocator has deeper level than" &
4277 " designated class-wide type", E);
4283 -- Check for allocation from an empty storage pool
4285 if No_Pool_Assigned (Typ) then
4286 Error_Msg_N ("allocation from empty storage pool!", N);
4288 -- If the context is an unchecked conversion, as may happen within an
4289 -- inlined subprogram, the allocator is being resolved with its own
4290 -- anonymous type. In that case, if the target type has a specific
4291 -- storage pool, it must be inherited explicitly by the allocator type.
4293 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4294 and then No (Associated_Storage_Pool (Typ))
4296 Set_Associated_Storage_Pool
4297 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4300 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4301 Check_Restriction (No_Anonymous_Allocators, N);
4304 -- An erroneous allocator may be rewritten as a raise Program_Error
4307 if Nkind (N) = N_Allocator then
4309 -- An anonymous access discriminant is the definition of a
4312 if Ekind (Typ) = E_Anonymous_Access_Type
4313 and then Nkind (Associated_Node_For_Itype (Typ)) =
4314 N_Discriminant_Specification
4316 -- Avoid marking an allocator as a dynamic coextension if it is
4317 -- within a static construct.
4319 if not Is_Static_Coextension (N) then
4320 Set_Is_Dynamic_Coextension (N);
4323 -- Cleanup for potential static coextensions
4326 Set_Is_Dynamic_Coextension (N, False);
4327 Set_Is_Static_Coextension (N, False);
4330 end Resolve_Allocator;
4332 ---------------------------
4333 -- Resolve_Arithmetic_Op --
4334 ---------------------------
4336 -- Used for resolving all arithmetic operators except exponentiation
4338 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4339 L : constant Node_Id := Left_Opnd (N);
4340 R : constant Node_Id := Right_Opnd (N);
4341 TL : constant Entity_Id := Base_Type (Etype (L));
4342 TR : constant Entity_Id := Base_Type (Etype (R));
4346 B_Typ : constant Entity_Id := Base_Type (Typ);
4347 -- We do the resolution using the base type, because intermediate values
4348 -- in expressions always are of the base type, not a subtype of it.
4350 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4351 -- Returns True if N is in a context that expects "any real type"
4353 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4354 -- Return True iff given type is Integer or universal real/integer
4356 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4357 -- Choose type of integer literal in fixed-point operation to conform
4358 -- to available fixed-point type. T is the type of the other operand,
4359 -- which is needed to determine the expected type of N.
4361 procedure Set_Operand_Type (N : Node_Id);
4362 -- Set operand type to T if universal
4364 -------------------------------
4365 -- Expected_Type_Is_Any_Real --
4366 -------------------------------
4368 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4370 -- N is the expression after "delta" in a fixed_point_definition;
4373 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4374 N_Decimal_Fixed_Point_Definition,
4376 -- N is one of the bounds in a real_range_specification;
4379 N_Real_Range_Specification,
4381 -- N is the expression of a delta_constraint;
4384 N_Delta_Constraint);
4385 end Expected_Type_Is_Any_Real;
4387 -----------------------------
4388 -- Is_Integer_Or_Universal --
4389 -----------------------------
4391 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4393 Index : Interp_Index;
4397 if not Is_Overloaded (N) then
4399 return Base_Type (T) = Base_Type (Standard_Integer)
4400 or else T = Universal_Integer
4401 or else T = Universal_Real;
4403 Get_First_Interp (N, Index, It);
4404 while Present (It.Typ) loop
4405 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4406 or else It.Typ = Universal_Integer
4407 or else It.Typ = Universal_Real
4412 Get_Next_Interp (Index, It);
4417 end Is_Integer_Or_Universal;
4419 ----------------------------
4420 -- Set_Mixed_Mode_Operand --
4421 ----------------------------
4423 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4424 Index : Interp_Index;
4428 if Universal_Interpretation (N) = Universal_Integer then
4430 -- A universal integer literal is resolved as standard integer
4431 -- except in the case of a fixed-point result, where we leave it
4432 -- as universal (to be handled by Exp_Fixd later on)
4434 if Is_Fixed_Point_Type (T) then
4435 Resolve (N, Universal_Integer);
4437 Resolve (N, Standard_Integer);
4440 elsif Universal_Interpretation (N) = Universal_Real
4441 and then (T = Base_Type (Standard_Integer)
4442 or else T = Universal_Integer
4443 or else T = Universal_Real)
4445 -- A universal real can appear in a fixed-type context. We resolve
4446 -- the literal with that context, even though this might raise an
4447 -- exception prematurely (the other operand may be zero).
4451 elsif Etype (N) = Base_Type (Standard_Integer)
4452 and then T = Universal_Real
4453 and then Is_Overloaded (N)
4455 -- Integer arg in mixed-mode operation. Resolve with universal
4456 -- type, in case preference rule must be applied.
4458 Resolve (N, Universal_Integer);
4461 and then B_Typ /= Universal_Fixed
4463 -- Not a mixed-mode operation, resolve with context
4467 elsif Etype (N) = Any_Fixed then
4469 -- N may itself be a mixed-mode operation, so use context type
4473 elsif Is_Fixed_Point_Type (T)
4474 and then B_Typ = Universal_Fixed
4475 and then Is_Overloaded (N)
4477 -- Must be (fixed * fixed) operation, operand must have one
4478 -- compatible interpretation.
4480 Resolve (N, Any_Fixed);
4482 elsif Is_Fixed_Point_Type (B_Typ)
4483 and then (T = Universal_Real
4484 or else Is_Fixed_Point_Type (T))
4485 and then Is_Overloaded (N)
4487 -- C * F(X) in a fixed context, where C is a real literal or a
4488 -- fixed-point expression. F must have either a fixed type
4489 -- interpretation or an integer interpretation, but not both.
4491 Get_First_Interp (N, Index, It);
4492 while Present (It.Typ) loop
4493 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4494 if Analyzed (N) then
4495 Error_Msg_N ("ambiguous operand in fixed operation", N);
4497 Resolve (N, Standard_Integer);
4500 elsif Is_Fixed_Point_Type (It.Typ) then
4501 if Analyzed (N) then
4502 Error_Msg_N ("ambiguous operand in fixed operation", N);
4504 Resolve (N, It.Typ);
4508 Get_Next_Interp (Index, It);
4511 -- Reanalyze the literal with the fixed type of the context. If
4512 -- context is Universal_Fixed, we are within a conversion, leave
4513 -- the literal as a universal real because there is no usable
4514 -- fixed type, and the target of the conversion plays no role in
4528 if B_Typ = Universal_Fixed
4529 and then Nkind (Op2) = N_Real_Literal
4531 T2 := Universal_Real;
4536 Set_Analyzed (Op2, False);
4543 end Set_Mixed_Mode_Operand;
4545 ----------------------
4546 -- Set_Operand_Type --
4547 ----------------------
4549 procedure Set_Operand_Type (N : Node_Id) is
4551 if Etype (N) = Universal_Integer
4552 or else Etype (N) = Universal_Real
4556 end Set_Operand_Type;
4558 -- Start of processing for Resolve_Arithmetic_Op
4561 if Comes_From_Source (N)
4562 and then Ekind (Entity (N)) = E_Function
4563 and then Is_Imported (Entity (N))
4564 and then Is_Intrinsic_Subprogram (Entity (N))
4566 Resolve_Intrinsic_Operator (N, Typ);
4569 -- Special-case for mixed-mode universal expressions or fixed point type
4570 -- operation: each argument is resolved separately. The same treatment
4571 -- is required if one of the operands of a fixed point operation is
4572 -- universal real, since in this case we don't do a conversion to a
4573 -- specific fixed-point type (instead the expander handles the case).
4575 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4576 and then Present (Universal_Interpretation (L))
4577 and then Present (Universal_Interpretation (R))
4579 Resolve (L, Universal_Interpretation (L));
4580 Resolve (R, Universal_Interpretation (R));
4581 Set_Etype (N, B_Typ);
4583 elsif (B_Typ = Universal_Real
4584 or else Etype (N) = Universal_Fixed
4585 or else (Etype (N) = Any_Fixed
4586 and then Is_Fixed_Point_Type (B_Typ))
4587 or else (Is_Fixed_Point_Type (B_Typ)
4588 and then (Is_Integer_Or_Universal (L)
4590 Is_Integer_Or_Universal (R))))
4591 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4593 if TL = Universal_Integer or else TR = Universal_Integer then
4594 Check_For_Visible_Operator (N, B_Typ);
4597 -- If context is a fixed type and one operand is integer, the other
4598 -- is resolved with the type of the context.
4600 if Is_Fixed_Point_Type (B_Typ)
4601 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4602 or else TL = Universal_Integer)
4607 elsif Is_Fixed_Point_Type (B_Typ)
4608 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4609 or else TR = Universal_Integer)
4615 Set_Mixed_Mode_Operand (L, TR);
4616 Set_Mixed_Mode_Operand (R, TL);
4619 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4620 -- multiplying operators from being used when the expected type is
4621 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4622 -- some cases where the expected type is actually Any_Real;
4623 -- Expected_Type_Is_Any_Real takes care of that case.
4625 if Etype (N) = Universal_Fixed
4626 or else Etype (N) = Any_Fixed
4628 if B_Typ = Universal_Fixed
4629 and then not Expected_Type_Is_Any_Real (N)
4630 and then not Nkind_In (Parent (N), N_Type_Conversion,
4631 N_Unchecked_Type_Conversion)
4633 Error_Msg_N ("type cannot be determined from context!", N);
4634 Error_Msg_N ("\explicit conversion to result type required", N);
4636 Set_Etype (L, Any_Type);
4637 Set_Etype (R, Any_Type);
4640 if Ada_Version = Ada_83
4641 and then Etype (N) = Universal_Fixed
4643 Nkind_In (Parent (N), N_Type_Conversion,
4644 N_Unchecked_Type_Conversion)
4647 ("(Ada 83) fixed-point operation "
4648 & "needs explicit conversion", N);
4651 -- The expected type is "any real type" in contexts like
4653 -- type T is delta <universal_fixed-expression> ...
4655 -- in which case we need to set the type to Universal_Real
4656 -- so that static expression evaluation will work properly.
4658 if Expected_Type_Is_Any_Real (N) then
4659 Set_Etype (N, Universal_Real);
4661 Set_Etype (N, B_Typ);
4665 elsif Is_Fixed_Point_Type (B_Typ)
4666 and then (Is_Integer_Or_Universal (L)
4667 or else Nkind (L) = N_Real_Literal
4668 or else Nkind (R) = N_Real_Literal
4669 or else Is_Integer_Or_Universal (R))
4671 Set_Etype (N, B_Typ);
4673 elsif Etype (N) = Any_Fixed then
4675 -- If no previous errors, this is only possible if one operand is
4676 -- overloaded and the context is universal. Resolve as such.
4678 Set_Etype (N, B_Typ);
4682 if (TL = Universal_Integer or else TL = Universal_Real)
4684 (TR = Universal_Integer or else TR = Universal_Real)
4686 Check_For_Visible_Operator (N, B_Typ);
4689 -- If the context is Universal_Fixed and the operands are also
4690 -- universal fixed, this is an error, unless there is only one
4691 -- applicable fixed_point type (usually Duration).
4693 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4694 T := Unique_Fixed_Point_Type (N);
4696 if T = Any_Type then
4709 -- If one of the arguments was resolved to a non-universal type.
4710 -- label the result of the operation itself with the same type.
4711 -- Do the same for the universal argument, if any.
4713 T := Intersect_Types (L, R);
4714 Set_Etype (N, Base_Type (T));
4715 Set_Operand_Type (L);
4716 Set_Operand_Type (R);
4719 Generate_Operator_Reference (N, Typ);
4720 Eval_Arithmetic_Op (N);
4722 -- In SPARK, a multiplication or division with operands of fixed point
4723 -- types shall be qualified or explicitly converted to identify the
4726 if (Is_Fixed_Point_Type (Etype (L))
4727 or else Is_Fixed_Point_Type (Etype (R)))
4728 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4730 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
4732 Check_SPARK_Restriction
4733 ("operation should be qualified or explicitly converted", N);
4736 -- Set overflow and division checking bit. Much cleverer code needed
4737 -- here eventually and perhaps the Resolve routines should be separated
4738 -- for the various arithmetic operations, since they will need
4739 -- different processing. ???
4741 if Nkind (N) in N_Op then
4742 if not Overflow_Checks_Suppressed (Etype (N)) then
4743 Enable_Overflow_Check (N);
4746 -- Give warning if explicit division by zero
4748 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4749 and then not Division_Checks_Suppressed (Etype (N))
4751 Rop := Right_Opnd (N);
4753 if Compile_Time_Known_Value (Rop)
4754 and then ((Is_Integer_Type (Etype (Rop))
4755 and then Expr_Value (Rop) = Uint_0)
4757 (Is_Real_Type (Etype (Rop))
4758 and then Expr_Value_R (Rop) = Ureal_0))
4760 -- Specialize the warning message according to the operation
4764 Apply_Compile_Time_Constraint_Error
4765 (N, "division by zero?", CE_Divide_By_Zero,
4766 Loc => Sloc (Right_Opnd (N)));
4769 Apply_Compile_Time_Constraint_Error
4770 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4771 Loc => Sloc (Right_Opnd (N)));
4774 Apply_Compile_Time_Constraint_Error
4775 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4776 Loc => Sloc (Right_Opnd (N)));
4778 -- Division by zero can only happen with division, rem,
4779 -- and mod operations.
4782 raise Program_Error;
4785 -- Otherwise just set the flag to check at run time
4788 Activate_Division_Check (N);
4792 -- If Restriction No_Implicit_Conditionals is active, then it is
4793 -- violated if either operand can be negative for mod, or for rem
4794 -- if both operands can be negative.
4796 if Restriction_Check_Required (No_Implicit_Conditionals)
4797 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4806 -- Set if corresponding operand might be negative
4810 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4811 LNeg := (not OK) or else Lo < 0;
4814 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4815 RNeg := (not OK) or else Lo < 0;
4817 -- Check if we will be generating conditionals. There are two
4818 -- cases where that can happen, first for REM, the only case
4819 -- is largest negative integer mod -1, where the division can
4820 -- overflow, but we still have to give the right result. The
4821 -- front end generates a test for this annoying case. Here we
4822 -- just test if both operands can be negative (that's what the
4823 -- expander does, so we match its logic here).
4825 -- The second case is mod where either operand can be negative.
4826 -- In this case, the back end has to generate additional tests.
4828 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4830 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4832 Check_Restriction (No_Implicit_Conditionals, N);
4838 Check_Unset_Reference (L);
4839 Check_Unset_Reference (R);
4840 end Resolve_Arithmetic_Op;
4846 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4847 Loc : constant Source_Ptr := Sloc (N);
4848 Subp : constant Node_Id := Name (N);
4856 function Same_Or_Aliased_Subprograms
4858 E : Entity_Id) return Boolean;
4859 -- Returns True if the subprogram entity S is the same as E or else
4860 -- S is an alias of E.
4862 ---------------------------------
4863 -- Same_Or_Aliased_Subprograms --
4864 ---------------------------------
4866 function Same_Or_Aliased_Subprograms
4868 E : Entity_Id) return Boolean
4870 Subp_Alias : constant Entity_Id := Alias (S);
4873 or else (Present (Subp_Alias) and then Subp_Alias = E);
4874 end Same_Or_Aliased_Subprograms;
4876 -- Start of processing for Resolve_Call
4879 -- The context imposes a unique interpretation with type Typ on a
4880 -- procedure or function call. Find the entity of the subprogram that
4881 -- yields the expected type, and propagate the corresponding formal
4882 -- constraints on the actuals. The caller has established that an
4883 -- interpretation exists, and emitted an error if not unique.
4885 -- First deal with the case of a call to an access-to-subprogram,
4886 -- dereference made explicit in Analyze_Call.
4888 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4889 if not Is_Overloaded (Subp) then
4890 Nam := Etype (Subp);
4893 -- Find the interpretation whose type (a subprogram type) has a
4894 -- return type that is compatible with the context. Analysis of
4895 -- the node has established that one exists.
4899 Get_First_Interp (Subp, I, It);
4900 while Present (It.Typ) loop
4901 if Covers (Typ, Etype (It.Typ)) then
4906 Get_Next_Interp (I, It);
4910 raise Program_Error;
4914 -- If the prefix is not an entity, then resolve it
4916 if not Is_Entity_Name (Subp) then
4917 Resolve (Subp, Nam);
4920 -- For an indirect call, we always invalidate checks, since we do not
4921 -- know whether the subprogram is local or global. Yes we could do
4922 -- better here, e.g. by knowing that there are no local subprograms,
4923 -- but it does not seem worth the effort. Similarly, we kill all
4924 -- knowledge of current constant values.
4926 Kill_Current_Values;
4928 -- If this is a procedure call which is really an entry call, do
4929 -- the conversion of the procedure call to an entry call. Protected
4930 -- operations use the same circuitry because the name in the call
4931 -- can be an arbitrary expression with special resolution rules.
4933 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4934 or else (Is_Entity_Name (Subp)
4935 and then Ekind (Entity (Subp)) = E_Entry)
4937 Resolve_Entry_Call (N, Typ);
4938 Check_Elab_Call (N);
4940 -- Kill checks and constant values, as above for indirect case
4941 -- Who knows what happens when another task is activated?
4943 Kill_Current_Values;
4946 -- Normal subprogram call with name established in Resolve
4948 elsif not (Is_Type (Entity (Subp))) then
4949 Nam := Entity (Subp);
4950 Set_Entity_With_Style_Check (Subp, Nam);
4952 -- Otherwise we must have the case of an overloaded call
4955 pragma Assert (Is_Overloaded (Subp));
4957 -- Initialize Nam to prevent warning (we know it will be assigned
4958 -- in the loop below, but the compiler does not know that).
4962 Get_First_Interp (Subp, I, It);
4963 while Present (It.Typ) loop
4964 if Covers (Typ, It.Typ) then
4966 Set_Entity_With_Style_Check (Subp, Nam);
4970 Get_Next_Interp (I, It);
4974 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4975 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4976 and then Nkind (Subp) /= N_Explicit_Dereference
4977 and then Present (Parameter_Associations (N))
4979 -- The prefix is a parameterless function call that returns an access
4980 -- to subprogram. If parameters are present in the current call, add
4981 -- add an explicit dereference. We use the base type here because
4982 -- within an instance these may be subtypes.
4984 -- The dereference is added either in Analyze_Call or here. Should
4985 -- be consolidated ???
4987 Set_Is_Overloaded (Subp, False);
4988 Set_Etype (Subp, Etype (Nam));
4989 Insert_Explicit_Dereference (Subp);
4990 Nam := Designated_Type (Etype (Nam));
4991 Resolve (Subp, Nam);
4994 -- Check that a call to Current_Task does not occur in an entry body
4996 if Is_RTE (Nam, RE_Current_Task) then
5005 -- Exclude calls that occur within the default of a formal
5006 -- parameter of the entry, since those are evaluated outside
5009 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5011 if Nkind (P) = N_Entry_Body
5012 or else (Nkind (P) = N_Subprogram_Body
5013 and then Is_Entry_Barrier_Function (P))
5017 ("?& should not be used in entry body (RM C.7(17))",
5020 ("\Program_Error will be raised at run time?", N, Nam);
5022 Make_Raise_Program_Error (Loc,
5023 Reason => PE_Current_Task_In_Entry_Body));
5024 Set_Etype (N, Rtype);
5031 -- Check that a procedure call does not occur in the context of the
5032 -- entry call statement of a conditional or timed entry call. Note that
5033 -- the case of a call to a subprogram renaming of an entry will also be
5034 -- rejected. The test for N not being an N_Entry_Call_Statement is
5035 -- defensive, covering the possibility that the processing of entry
5036 -- calls might reach this point due to later modifications of the code
5039 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5040 and then Nkind (N) /= N_Entry_Call_Statement
5041 and then Entry_Call_Statement (Parent (N)) = N
5043 if Ada_Version < Ada_2005 then
5044 Error_Msg_N ("entry call required in select statement", N);
5046 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5047 -- for a procedure_or_entry_call, the procedure_name or
5048 -- procedure_prefix of the procedure_call_statement shall denote
5049 -- an entry renamed by a procedure, or (a view of) a primitive
5050 -- subprogram of a limited interface whose first parameter is
5051 -- a controlling parameter.
5053 elsif Nkind (N) = N_Procedure_Call_Statement
5054 and then not Is_Renamed_Entry (Nam)
5055 and then not Is_Controlling_Limited_Procedure (Nam)
5058 ("entry call or dispatching primitive of interface required", N);
5062 -- Check that this is not a call to a protected procedure or entry from
5063 -- within a protected function.
5065 if Ekind (Current_Scope) = E_Function
5066 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
5067 and then Ekind (Nam) /= E_Function
5068 and then Scope (Nam) = Scope (Current_Scope)
5070 Error_Msg_N ("within protected function, protected " &
5071 "object is constant", N);
5072 Error_Msg_N ("\cannot call operation that may modify it", N);
5075 -- Freeze the subprogram name if not in a spec-expression. Note that we
5076 -- freeze procedure calls as well as function calls. Procedure calls are
5077 -- not frozen according to the rules (RM 13.14(14)) because it is
5078 -- impossible to have a procedure call to a non-frozen procedure in pure
5079 -- Ada, but in the code that we generate in the expander, this rule
5080 -- needs extending because we can generate procedure calls that need
5083 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
5084 Freeze_Expression (Subp);
5087 -- For a predefined operator, the type of the result is the type imposed
5088 -- by context, except for a predefined operation on universal fixed.
5089 -- Otherwise The type of the call is the type returned by the subprogram
5092 if Is_Predefined_Op (Nam) then
5093 if Etype (N) /= Universal_Fixed then
5097 -- If the subprogram returns an array type, and the context requires the
5098 -- component type of that array type, the node is really an indexing of
5099 -- the parameterless call. Resolve as such. A pathological case occurs
5100 -- when the type of the component is an access to the array type. In
5101 -- this case the call is truly ambiguous.
5103 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5105 ((Is_Array_Type (Etype (Nam))
5106 and then Covers (Typ, Component_Type (Etype (Nam))))
5107 or else (Is_Access_Type (Etype (Nam))
5108 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5112 Component_Type (Designated_Type (Etype (Nam))))))
5115 Index_Node : Node_Id;
5117 Ret_Type : constant Entity_Id := Etype (Nam);
5120 if Is_Access_Type (Ret_Type)
5121 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5124 ("cannot disambiguate function call and indexing", N);
5126 New_Subp := Relocate_Node (Subp);
5127 Set_Entity (Subp, Nam);
5129 if (Is_Array_Type (Ret_Type)
5130 and then Component_Type (Ret_Type) /= Any_Type)
5132 (Is_Access_Type (Ret_Type)
5134 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5136 if Needs_No_Actuals (Nam) then
5138 -- Indexed call to a parameterless function
5141 Make_Indexed_Component (Loc,
5143 Make_Function_Call (Loc,
5145 Expressions => Parameter_Associations (N));
5147 -- An Ada 2005 prefixed call to a primitive operation
5148 -- whose first parameter is the prefix. This prefix was
5149 -- prepended to the parameter list, which is actually a
5150 -- list of indexes. Remove the prefix in order to build
5151 -- the proper indexed component.
5154 Make_Indexed_Component (Loc,
5156 Make_Function_Call (Loc,
5158 Parameter_Associations =>
5160 (Remove_Head (Parameter_Associations (N)))),
5161 Expressions => Parameter_Associations (N));
5164 -- Preserve the parenthesis count of the node
5166 Set_Paren_Count (Index_Node, Paren_Count (N));
5168 -- Since we are correcting a node classification error made
5169 -- by the parser, we call Replace rather than Rewrite.
5171 Replace (N, Index_Node);
5173 Set_Etype (Prefix (N), Ret_Type);
5175 Resolve_Indexed_Component (N, Typ);
5176 Check_Elab_Call (Prefix (N));
5184 Set_Etype (N, Etype (Nam));
5187 -- In the case where the call is to an overloaded subprogram, Analyze
5188 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5189 -- such a case Normalize_Actuals needs to be called once more to order
5190 -- the actuals correctly. Otherwise the call will have the ordering
5191 -- given by the last overloaded subprogram whether this is the correct
5192 -- one being called or not.
5194 if Is_Overloaded (Subp) then
5195 Normalize_Actuals (N, Nam, False, Norm_OK);
5196 pragma Assert (Norm_OK);
5199 -- In any case, call is fully resolved now. Reset Overload flag, to
5200 -- prevent subsequent overload resolution if node is analyzed again
5202 Set_Is_Overloaded (Subp, False);
5203 Set_Is_Overloaded (N, False);
5205 -- If we are calling the current subprogram from immediately within its
5206 -- body, then that is the case where we can sometimes detect cases of
5207 -- infinite recursion statically. Do not try this in case restriction
5208 -- No_Recursion is in effect anyway, and do it only for source calls.
5210 if Comes_From_Source (N) then
5211 Scop := Current_Scope;
5213 -- Issue warning for possible infinite recursion in the absence
5214 -- of the No_Recursion restriction.
5216 if Same_Or_Aliased_Subprograms (Nam, Scop)
5217 and then not Restriction_Active (No_Recursion)
5218 and then Check_Infinite_Recursion (N)
5220 -- Here we detected and flagged an infinite recursion, so we do
5221 -- not need to test the case below for further warnings. Also we
5222 -- are all done if we now have a raise SE node.
5224 if Nkind (N) = N_Raise_Storage_Error then
5228 -- If call is to immediately containing subprogram, then check for
5229 -- the case of a possible run-time detectable infinite recursion.
5232 Scope_Loop : while Scop /= Standard_Standard loop
5233 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5235 -- Although in general case, recursion is not statically
5236 -- checkable, the case of calling an immediately containing
5237 -- subprogram is easy to catch.
5239 Check_Restriction (No_Recursion, N);
5241 -- If the recursive call is to a parameterless subprogram,
5242 -- then even if we can't statically detect infinite
5243 -- recursion, this is pretty suspicious, and we output a
5244 -- warning. Furthermore, we will try later to detect some
5245 -- cases here at run time by expanding checking code (see
5246 -- Detect_Infinite_Recursion in package Exp_Ch6).
5248 -- If the recursive call is within a handler, do not emit a
5249 -- warning, because this is a common idiom: loop until input
5250 -- is correct, catch illegal input in handler and restart.
5252 if No (First_Formal (Nam))
5253 and then Etype (Nam) = Standard_Void_Type
5254 and then not Error_Posted (N)
5255 and then Nkind (Parent (N)) /= N_Exception_Handler
5257 -- For the case of a procedure call. We give the message
5258 -- only if the call is the first statement in a sequence
5259 -- of statements, or if all previous statements are
5260 -- simple assignments. This is simply a heuristic to
5261 -- decrease false positives, without losing too many good
5262 -- warnings. The idea is that these previous statements
5263 -- may affect global variables the procedure depends on.
5265 if Nkind (N) = N_Procedure_Call_Statement
5266 and then Is_List_Member (N)
5272 while Present (P) loop
5273 if Nkind (P) /= N_Assignment_Statement then
5282 -- Do not give warning if we are in a conditional context
5285 K : constant Node_Kind := Nkind (Parent (N));
5287 if (K = N_Loop_Statement
5288 and then Present (Iteration_Scheme (Parent (N))))
5289 or else K = N_If_Statement
5290 or else K = N_Elsif_Part
5291 or else K = N_Case_Statement_Alternative
5297 -- Here warning is to be issued
5299 Set_Has_Recursive_Call (Nam);
5301 ("?possible infinite recursion!", N);
5303 ("\?Storage_Error may be raised at run time!", N);
5309 Scop := Scope (Scop);
5310 end loop Scope_Loop;
5314 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5316 Check_Obsolescent_2005_Entity (Nam, Subp);
5318 -- If subprogram name is a predefined operator, it was given in
5319 -- functional notation. Replace call node with operator node, so
5320 -- that actuals can be resolved appropriately.
5322 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5323 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5326 elsif Present (Alias (Nam))
5327 and then Is_Predefined_Op (Alias (Nam))
5329 Resolve_Actuals (N, Nam);
5330 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5334 -- Create a transient scope if the resulting type requires it
5336 -- There are several notable exceptions:
5338 -- a) In init procs, the transient scope overhead is not needed, and is
5339 -- even incorrect when the call is a nested initialization call for a
5340 -- component whose expansion may generate adjust calls. However, if the
5341 -- call is some other procedure call within an initialization procedure
5342 -- (for example a call to Create_Task in the init_proc of the task
5343 -- run-time record) a transient scope must be created around this call.
5345 -- b) Enumeration literal pseudo-calls need no transient scope
5347 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5348 -- functions) do not use the secondary stack even though the return
5349 -- type may be unconstrained.
5351 -- d) Calls to a build-in-place function, since such functions may
5352 -- allocate their result directly in a target object, and cases where
5353 -- the result does get allocated in the secondary stack are checked for
5354 -- within the specialized Exp_Ch6 procedures for expanding those
5355 -- build-in-place calls.
5357 -- e) If the subprogram is marked Inline_Always, then even if it returns
5358 -- an unconstrained type the call does not require use of the secondary
5359 -- stack. However, inlining will only take place if the body to inline
5360 -- is already present. It may not be available if e.g. the subprogram is
5361 -- declared in a child instance.
5363 -- If this is an initialization call for a type whose construction
5364 -- uses the secondary stack, and it is not a nested call to initialize
5365 -- a component, we do need to create a transient scope for it. We
5366 -- check for this by traversing the type in Check_Initialization_Call.
5369 and then Has_Pragma_Inline_Always (Nam)
5370 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5371 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5375 elsif Ekind (Nam) = E_Enumeration_Literal
5376 or else Is_Build_In_Place_Function (Nam)
5377 or else Is_Intrinsic_Subprogram (Nam)
5381 elsif Expander_Active
5382 and then Is_Type (Etype (Nam))
5383 and then Requires_Transient_Scope (Etype (Nam))
5385 (not Within_Init_Proc
5387 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5389 Establish_Transient_Scope (N, Sec_Stack => True);
5391 -- If the call appears within the bounds of a loop, it will
5392 -- be rewritten and reanalyzed, nothing left to do here.
5394 if Nkind (N) /= N_Function_Call then
5398 elsif Is_Init_Proc (Nam)
5399 and then not Within_Init_Proc
5401 Check_Initialization_Call (N, Nam);
5404 -- A protected function cannot be called within the definition of the
5405 -- enclosing protected type.
5407 if Is_Protected_Type (Scope (Nam))
5408 and then In_Open_Scopes (Scope (Nam))
5409 and then not Has_Completion (Scope (Nam))
5412 ("& cannot be called before end of protected definition", N, Nam);
5415 -- Propagate interpretation to actuals, and add default expressions
5418 if Present (First_Formal (Nam)) then
5419 Resolve_Actuals (N, Nam);
5421 -- Overloaded literals are rewritten as function calls, for purpose of
5422 -- resolution. After resolution, we can replace the call with the
5425 elsif Ekind (Nam) = E_Enumeration_Literal then
5426 Copy_Node (Subp, N);
5427 Resolve_Entity_Name (N, Typ);
5429 -- Avoid validation, since it is a static function call
5431 Generate_Reference (Nam, Subp);
5435 -- If the subprogram is not global, then kill all saved values and
5436 -- checks. This is a bit conservative, since in many cases we could do
5437 -- better, but it is not worth the effort. Similarly, we kill constant
5438 -- values. However we do not need to do this for internal entities
5439 -- (unless they are inherited user-defined subprograms), since they
5440 -- are not in the business of molesting local values.
5442 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5443 -- kill all checks and values for calls to global subprograms. This
5444 -- takes care of the case where an access to a local subprogram is
5445 -- taken, and could be passed directly or indirectly and then called
5446 -- from almost any context.
5448 -- Note: we do not do this step till after resolving the actuals. That
5449 -- way we still take advantage of the current value information while
5450 -- scanning the actuals.
5452 -- We suppress killing values if we are processing the nodes associated
5453 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5454 -- type kills all the values as part of analyzing the code that
5455 -- initializes the dispatch tables.
5457 if Inside_Freezing_Actions = 0
5458 and then (not Is_Library_Level_Entity (Nam)
5459 or else Suppress_Value_Tracking_On_Call
5460 (Nearest_Dynamic_Scope (Current_Scope)))
5461 and then (Comes_From_Source (Nam)
5462 or else (Present (Alias (Nam))
5463 and then Comes_From_Source (Alias (Nam))))
5465 Kill_Current_Values;
5468 -- If we are warning about unread OUT parameters, this is the place to
5469 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5470 -- after the above call to Kill_Current_Values (since that call clears
5471 -- the Last_Assignment field of all local variables).
5473 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5474 and then Comes_From_Source (N)
5475 and then In_Extended_Main_Source_Unit (N)
5482 F := First_Formal (Nam);
5483 A := First_Actual (N);
5484 while Present (F) and then Present (A) loop
5485 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
5486 and then Warn_On_Modified_As_Out_Parameter (F)
5487 and then Is_Entity_Name (A)
5488 and then Present (Entity (A))
5489 and then Comes_From_Source (N)
5490 and then Safe_To_Capture_Value (N, Entity (A))
5492 Set_Last_Assignment (Entity (A), A);
5501 -- If the subprogram is a primitive operation, check whether or not
5502 -- it is a correct dispatching call.
5504 if Is_Overloadable (Nam)
5505 and then Is_Dispatching_Operation (Nam)
5507 Check_Dispatching_Call (N);
5509 elsif Ekind (Nam) /= E_Subprogram_Type
5510 and then Is_Abstract_Subprogram (Nam)
5511 and then not In_Instance
5513 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5516 -- If this is a dispatching call, generate the appropriate reference,
5517 -- for better source navigation in GPS.
5519 if Is_Overloadable (Nam)
5520 and then Present (Controlling_Argument (N))
5522 Generate_Reference (Nam, Subp, 'R');
5524 -- Normal case, not a dispatching call: generate a call reference
5527 Generate_Reference (Nam, Subp, 's');
5530 if Is_Intrinsic_Subprogram (Nam) then
5531 Check_Intrinsic_Call (N);
5534 -- Check for violation of restriction No_Specific_Termination_Handlers
5535 -- and warn on a potentially blocking call to Abort_Task.
5537 if Restriction_Check_Required (No_Specific_Termination_Handlers)
5538 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
5540 Is_RTE (Nam, RE_Specific_Handler))
5542 Check_Restriction (No_Specific_Termination_Handlers, N);
5544 elsif Is_RTE (Nam, RE_Abort_Task) then
5545 Check_Potentially_Blocking_Operation (N);
5548 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5549 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5550 -- need to check the second argument to determine whether it is an
5551 -- absolute or relative timing event.
5553 if Restriction_Check_Required (No_Relative_Delay)
5554 and then Is_RTE (Nam, RE_Set_Handler)
5555 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
5557 Check_Restriction (No_Relative_Delay, N);
5560 -- Issue an error for a call to an eliminated subprogram. We skip this
5561 -- in a spec expression, e.g. a call in a default parameter value, since
5562 -- we are not really doing a call at this time. That's important because
5563 -- the spec expression may itself belong to an eliminated subprogram.
5565 if not In_Spec_Expression then
5566 Check_For_Eliminated_Subprogram (Subp, Nam);
5569 -- In formal mode, the primitive operations of a tagged type or type
5570 -- extension do not include functions that return the tagged type.
5572 -- Commented out as the call to Is_Inherited_Operation_For_Type may
5573 -- cause an error because the type entity of the parent node of
5574 -- Entity (Name (N) may not be set. ???
5575 -- So why not just add a guard ???
5577 -- if Nkind (N) = N_Function_Call
5578 -- and then Is_Tagged_Type (Etype (N))
5579 -- and then Is_Entity_Name (Name (N))
5580 -- and then Is_Inherited_Operation_For_Type
5581 -- (Entity (Name (N)), Etype (N))
5583 -- Check_SPARK_Restriction ("function not inherited", N);
5586 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
5587 -- class-wide and the call dispatches on result in a context that does
5588 -- not provide a tag, the call raises Program_Error.
5590 if Nkind (N) = N_Function_Call
5591 and then In_Instance
5592 and then Is_Generic_Actual_Type (Typ)
5593 and then Is_Class_Wide_Type (Typ)
5594 and then Has_Controlling_Result (Nam)
5595 and then Nkind (Parent (N)) = N_Object_Declaration
5597 -- Verify that none of the formals are controlling
5600 Call_OK : Boolean := False;
5604 F := First_Formal (Nam);
5605 while Present (F) loop
5606 if Is_Controlling_Formal (F) then
5615 Error_Msg_N ("!? cannot determine tag of result", N);
5616 Error_Msg_N ("!? Program_Error will be raised", N);
5618 Make_Raise_Program_Error (Sloc (N),
5619 Reason => PE_Explicit_Raise));
5624 -- All done, evaluate call and deal with elaboration issues
5627 Check_Elab_Call (N);
5628 Warn_On_Overlapping_Actuals (Nam, N);
5631 -----------------------------
5632 -- Resolve_Case_Expression --
5633 -----------------------------
5635 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
5639 Alt := First (Alternatives (N));
5640 while Present (Alt) loop
5641 Resolve (Expression (Alt), Typ);
5646 Eval_Case_Expression (N);
5647 end Resolve_Case_Expression;
5649 -------------------------------
5650 -- Resolve_Character_Literal --
5651 -------------------------------
5653 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5654 B_Typ : constant Entity_Id := Base_Type (Typ);
5658 -- Verify that the character does belong to the type of the context
5660 Set_Etype (N, B_Typ);
5661 Eval_Character_Literal (N);
5663 -- Wide_Wide_Character literals must always be defined, since the set
5664 -- of wide wide character literals is complete, i.e. if a character
5665 -- literal is accepted by the parser, then it is OK for wide wide
5666 -- character (out of range character literals are rejected).
5668 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5671 -- Always accept character literal for type Any_Character, which
5672 -- occurs in error situations and in comparisons of literals, both
5673 -- of which should accept all literals.
5675 elsif B_Typ = Any_Character then
5678 -- For Standard.Character or a type derived from it, check that the
5679 -- literal is in range.
5681 elsif Root_Type (B_Typ) = Standard_Character then
5682 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5686 -- For Standard.Wide_Character or a type derived from it, check that the
5687 -- literal is in range.
5689 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5690 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5694 -- For Standard.Wide_Wide_Character or a type derived from it, we
5695 -- know the literal is in range, since the parser checked!
5697 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5700 -- If the entity is already set, this has already been resolved in a
5701 -- generic context, or comes from expansion. Nothing else to do.
5703 elsif Present (Entity (N)) then
5706 -- Otherwise we have a user defined character type, and we can use the
5707 -- standard visibility mechanisms to locate the referenced entity.
5710 C := Current_Entity (N);
5711 while Present (C) loop
5712 if Etype (C) = B_Typ then
5713 Set_Entity_With_Style_Check (N, C);
5714 Generate_Reference (C, N);
5722 -- If we fall through, then the literal does not match any of the
5723 -- entries of the enumeration type. This isn't just a constraint error
5724 -- situation, it is an illegality (see RM 4.2).
5727 ("character not defined for }", N, First_Subtype (B_Typ));
5728 end Resolve_Character_Literal;
5730 ---------------------------
5731 -- Resolve_Comparison_Op --
5732 ---------------------------
5734 -- Context requires a boolean type, and plays no role in resolution.
5735 -- Processing identical to that for equality operators. The result type is
5736 -- the base type, which matters when pathological subtypes of booleans with
5737 -- limited ranges are used.
5739 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5740 L : constant Node_Id := Left_Opnd (N);
5741 R : constant Node_Id := Right_Opnd (N);
5745 -- If this is an intrinsic operation which is not predefined, use the
5746 -- types of its declared arguments to resolve the possibly overloaded
5747 -- operands. Otherwise the operands are unambiguous and specify the
5750 if Scope (Entity (N)) /= Standard_Standard then
5751 T := Etype (First_Entity (Entity (N)));
5754 T := Find_Unique_Type (L, R);
5756 if T = Any_Fixed then
5757 T := Unique_Fixed_Point_Type (L);
5761 Set_Etype (N, Base_Type (Typ));
5762 Generate_Reference (T, N, ' ');
5764 -- Skip remaining processing if already set to Any_Type
5766 if T = Any_Type then
5770 -- Deal with other error cases
5772 if T = Any_String or else
5773 T = Any_Composite or else
5776 if T = Any_Character then
5777 Ambiguous_Character (L);
5779 Error_Msg_N ("ambiguous operands for comparison", N);
5782 Set_Etype (N, Any_Type);
5786 -- Resolve the operands if types OK
5790 Check_Unset_Reference (L);
5791 Check_Unset_Reference (R);
5792 Generate_Operator_Reference (N, T);
5793 Check_Low_Bound_Tested (N);
5795 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
5796 -- types or array types except String.
5798 if Is_Boolean_Type (T) then
5799 Mark_Non_ALFA_Subprogram
5800 ("ordering operator on boolean type is not in ALFA", N);
5801 Check_SPARK_Restriction
5802 ("comparison is not defined on Boolean type", N);
5804 elsif Is_Array_Type (T) then
5805 Mark_Non_ALFA_Subprogram
5806 ("ordering operator on array type is not in ALFA", N);
5808 if Base_Type (T) /= Standard_String then
5809 Check_SPARK_Restriction
5810 ("comparison is not defined on array types other than String",
5818 -- Check comparison on unordered enumeration
5820 if Comes_From_Source (N)
5821 and then Bad_Unordered_Enumeration_Reference (N, Etype (L))
5823 Error_Msg_N ("comparison on unordered enumeration type?", N);
5826 -- Evaluate the relation (note we do this after the above check since
5827 -- this Eval call may change N to True/False.
5829 Eval_Relational_Op (N);
5830 end Resolve_Comparison_Op;
5832 ------------------------------------
5833 -- Resolve_Conditional_Expression --
5834 ------------------------------------
5836 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5837 Condition : constant Node_Id := First (Expressions (N));
5838 Then_Expr : constant Node_Id := Next (Condition);
5839 Else_Expr : Node_Id := Next (Then_Expr);
5842 Resolve (Condition, Any_Boolean);
5843 Resolve (Then_Expr, Typ);
5845 -- If ELSE expression present, just resolve using the determined type
5847 if Present (Else_Expr) then
5848 Resolve (Else_Expr, Typ);
5850 -- If no ELSE expression is present, root type must be Standard.Boolean
5851 -- and we provide a Standard.True result converted to the appropriate
5852 -- Boolean type (in case it is a derived boolean type).
5854 elsif Root_Type (Typ) = Standard_Boolean then
5856 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5857 Analyze_And_Resolve (Else_Expr, Typ);
5858 Append_To (Expressions (N), Else_Expr);
5861 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5862 Append_To (Expressions (N), Error);
5865 if Root_Type (Typ) /= Standard_Boolean then
5866 Mark_Non_ALFA_Subprogram
5867 ("non-boolean conditional expression is not in ALFA", N);
5871 Eval_Conditional_Expression (N);
5872 end Resolve_Conditional_Expression;
5874 -----------------------------------------
5875 -- Resolve_Discrete_Subtype_Indication --
5876 -----------------------------------------
5878 procedure Resolve_Discrete_Subtype_Indication
5886 Analyze (Subtype_Mark (N));
5887 S := Entity (Subtype_Mark (N));
5889 if Nkind (Constraint (N)) /= N_Range_Constraint then
5890 Error_Msg_N ("expect range constraint for discrete type", N);
5891 Set_Etype (N, Any_Type);
5894 R := Range_Expression (Constraint (N));
5902 if Base_Type (S) /= Base_Type (Typ) then
5904 ("expect subtype of }", N, First_Subtype (Typ));
5906 -- Rewrite the constraint as a range of Typ
5907 -- to allow compilation to proceed further.
5910 Rewrite (Low_Bound (R),
5911 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5912 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5913 Attribute_Name => Name_First));
5914 Rewrite (High_Bound (R),
5915 Make_Attribute_Reference (Sloc (High_Bound (R)),
5916 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5917 Attribute_Name => Name_First));
5921 Set_Etype (N, Etype (R));
5923 -- Additionally, we must check that the bounds are compatible
5924 -- with the given subtype, which might be different from the
5925 -- type of the context.
5927 Apply_Range_Check (R, S);
5929 -- ??? If the above check statically detects a Constraint_Error
5930 -- it replaces the offending bound(s) of the range R with a
5931 -- Constraint_Error node. When the itype which uses these bounds
5932 -- is frozen the resulting call to Duplicate_Subexpr generates
5933 -- a new temporary for the bounds.
5935 -- Unfortunately there are other itypes that are also made depend
5936 -- on these bounds, so when Duplicate_Subexpr is called they get
5937 -- a forward reference to the newly created temporaries and Gigi
5938 -- aborts on such forward references. This is probably sign of a
5939 -- more fundamental problem somewhere else in either the order of
5940 -- itype freezing or the way certain itypes are constructed.
5942 -- To get around this problem we call Remove_Side_Effects right
5943 -- away if either bounds of R are a Constraint_Error.
5946 L : constant Node_Id := Low_Bound (R);
5947 H : constant Node_Id := High_Bound (R);
5950 if Nkind (L) = N_Raise_Constraint_Error then
5951 Remove_Side_Effects (L);
5954 if Nkind (H) = N_Raise_Constraint_Error then
5955 Remove_Side_Effects (H);
5959 Check_Unset_Reference (Low_Bound (R));
5960 Check_Unset_Reference (High_Bound (R));
5963 end Resolve_Discrete_Subtype_Indication;
5965 -------------------------
5966 -- Resolve_Entity_Name --
5967 -------------------------
5969 -- Used to resolve identifiers and expanded names
5971 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5972 E : constant Entity_Id := Entity (N);
5975 -- If garbage from errors, set to Any_Type and return
5977 if No (E) and then Total_Errors_Detected /= 0 then
5978 Set_Etype (N, Any_Type);
5982 -- Replace named numbers by corresponding literals. Note that this is
5983 -- the one case where Resolve_Entity_Name must reset the Etype, since
5984 -- it is currently marked as universal.
5986 if Ekind (E) = E_Named_Integer then
5988 Eval_Named_Integer (N);
5990 elsif Ekind (E) = E_Named_Real then
5992 Eval_Named_Real (N);
5994 -- For enumeration literals, we need to make sure that a proper style
5995 -- check is done, since such literals are overloaded, and thus we did
5996 -- not do a style check during the first phase of analysis.
5998 elsif Ekind (E) = E_Enumeration_Literal then
5999 Set_Entity_With_Style_Check (N, E);
6000 Eval_Entity_Name (N);
6002 -- Case of subtype name appearing as an operand in expression
6004 elsif Is_Type (E) then
6006 -- Allow use of subtype if it is a concurrent type where we are
6007 -- currently inside the body. This will eventually be expanded into a
6008 -- call to Self (for tasks) or _object (for protected objects). Any
6009 -- other use of a subtype is invalid.
6011 if Is_Concurrent_Type (E)
6012 and then In_Open_Scopes (E)
6016 -- Any other use is an error
6020 ("invalid use of subtype mark in expression or call", N);
6023 -- Check discriminant use if entity is discriminant in current scope,
6024 -- i.e. discriminant of record or concurrent type currently being
6025 -- analyzed. Uses in corresponding body are unrestricted.
6027 elsif Ekind (E) = E_Discriminant
6028 and then Scope (E) = Current_Scope
6029 and then not Has_Completion (Current_Scope)
6031 Check_Discriminant_Use (N);
6033 -- A parameterless generic function cannot appear in a context that
6034 -- requires resolution.
6036 elsif Ekind (E) = E_Generic_Function then
6037 Error_Msg_N ("illegal use of generic function", N);
6039 elsif Ekind (E) = E_Out_Parameter
6040 and then Ada_Version = Ada_83
6041 and then (Nkind (Parent (N)) in N_Op
6042 or else (Nkind (Parent (N)) = N_Assignment_Statement
6043 and then N = Expression (Parent (N)))
6044 or else Nkind (Parent (N)) = N_Explicit_Dereference)
6046 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6048 -- In all other cases, just do the possible static evaluation
6051 -- A deferred constant that appears in an expression must have a
6052 -- completion, unless it has been removed by in-place expansion of
6055 if Ekind (E) = E_Constant
6056 and then Comes_From_Source (E)
6057 and then No (Constant_Value (E))
6058 and then Is_Frozen (Etype (E))
6059 and then not In_Spec_Expression
6060 and then not Is_Imported (E)
6062 if No_Initialization (Parent (E))
6063 or else (Present (Full_View (E))
6064 and then No_Initialization (Parent (Full_View (E))))
6069 "deferred constant is frozen before completion", N);
6073 Eval_Entity_Name (N);
6075 end Resolve_Entity_Name;
6081 procedure Resolve_Entry (Entry_Name : Node_Id) is
6082 Loc : constant Source_Ptr := Sloc (Entry_Name);
6090 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6091 -- If the bounds of the entry family being called depend on task
6092 -- discriminants, build a new index subtype where a discriminant is
6093 -- replaced with the value of the discriminant of the target task.
6094 -- The target task is the prefix of the entry name in the call.
6096 -----------------------
6097 -- Actual_Index_Type --
6098 -----------------------
6100 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
6101 Typ : constant Entity_Id := Entry_Index_Type (E);
6102 Tsk : constant Entity_Id := Scope (E);
6103 Lo : constant Node_Id := Type_Low_Bound (Typ);
6104 Hi : constant Node_Id := Type_High_Bound (Typ);
6107 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6108 -- If the bound is given by a discriminant, replace with a reference
6109 -- to the discriminant of the same name in the target task. If the
6110 -- entry name is the target of a requeue statement and the entry is
6111 -- in the current protected object, the bound to be used is the
6112 -- discriminal of the object (see Apply_Range_Checks for details of
6113 -- the transformation).
6115 -----------------------------
6116 -- Actual_Discriminant_Ref --
6117 -----------------------------
6119 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
6120 Typ : constant Entity_Id := Etype (Bound);
6124 Remove_Side_Effects (Bound);
6126 if not Is_Entity_Name (Bound)
6127 or else Ekind (Entity (Bound)) /= E_Discriminant
6131 elsif Is_Protected_Type (Tsk)
6132 and then In_Open_Scopes (Tsk)
6133 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6135 -- Note: here Bound denotes a discriminant of the corresponding
6136 -- record type tskV, whose discriminal is a formal of the
6137 -- init-proc tskVIP. What we want is the body discriminal,
6138 -- which is associated to the discriminant of the original
6139 -- concurrent type tsk.
6141 return New_Occurrence_Of
6142 (Find_Body_Discriminal (Entity (Bound)), Loc);
6146 Make_Selected_Component (Loc,
6147 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6148 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6153 end Actual_Discriminant_Ref;
6155 -- Start of processing for Actual_Index_Type
6158 if not Has_Discriminants (Tsk)
6159 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
6161 return Entry_Index_Type (E);
6164 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6165 Set_Etype (New_T, Base_Type (Typ));
6166 Set_Size_Info (New_T, Typ);
6167 Set_RM_Size (New_T, RM_Size (Typ));
6168 Set_Scalar_Range (New_T,
6169 Make_Range (Sloc (Entry_Name),
6170 Low_Bound => Actual_Discriminant_Ref (Lo),
6171 High_Bound => Actual_Discriminant_Ref (Hi)));
6175 end Actual_Index_Type;
6177 -- Start of processing of Resolve_Entry
6180 -- Find name of entry being called, and resolve prefix of name with its
6181 -- own type. The prefix can be overloaded, and the name and signature of
6182 -- the entry must be taken into account.
6184 if Nkind (Entry_Name) = N_Indexed_Component then
6186 -- Case of dealing with entry family within the current tasks
6188 E_Name := Prefix (Entry_Name);
6191 E_Name := Entry_Name;
6194 if Is_Entity_Name (E_Name) then
6196 -- Entry call to an entry (or entry family) in the current task. This
6197 -- is legal even though the task will deadlock. Rewrite as call to
6200 -- This can also be a call to an entry in an enclosing task. If this
6201 -- is a single task, we have to retrieve its name, because the scope
6202 -- of the entry is the task type, not the object. If the enclosing
6203 -- task is a task type, the identity of the task is given by its own
6206 -- Finally this can be a requeue on an entry of the same task or
6207 -- protected object.
6209 S := Scope (Entity (E_Name));
6211 for J in reverse 0 .. Scope_Stack.Last loop
6212 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6213 and then not Comes_From_Source (S)
6215 -- S is an enclosing task or protected object. The concurrent
6216 -- declaration has been converted into a type declaration, and
6217 -- the object itself has an object declaration that follows
6218 -- the type in the same declarative part.
6220 Tsk := Next_Entity (S);
6221 while Etype (Tsk) /= S loop
6228 elsif S = Scope_Stack.Table (J).Entity then
6230 -- Call to current task. Will be transformed into call to Self
6238 Make_Selected_Component (Loc,
6239 Prefix => New_Occurrence_Of (S, Loc),
6241 New_Occurrence_Of (Entity (E_Name), Loc));
6242 Rewrite (E_Name, New_N);
6245 elsif Nkind (Entry_Name) = N_Selected_Component
6246 and then Is_Overloaded (Prefix (Entry_Name))
6248 -- Use the entry name (which must be unique at this point) to find
6249 -- the prefix that returns the corresponding task/protected type.
6252 Pref : constant Node_Id := Prefix (Entry_Name);
6253 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
6258 Get_First_Interp (Pref, I, It);
6259 while Present (It.Typ) loop
6260 if Scope (Ent) = It.Typ then
6261 Set_Etype (Pref, It.Typ);
6265 Get_Next_Interp (I, It);
6270 if Nkind (Entry_Name) = N_Selected_Component then
6271 Resolve (Prefix (Entry_Name));
6273 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6274 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6275 Resolve (Prefix (Prefix (Entry_Name)));
6276 Index := First (Expressions (Entry_Name));
6277 Resolve (Index, Entry_Index_Type (Nam));
6279 -- Up to this point the expression could have been the actual in a
6280 -- simple entry call, and be given by a named association.
6282 if Nkind (Index) = N_Parameter_Association then
6283 Error_Msg_N ("expect expression for entry index", Index);
6285 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6290 ------------------------
6291 -- Resolve_Entry_Call --
6292 ------------------------
6294 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6295 Entry_Name : constant Node_Id := Name (N);
6296 Loc : constant Source_Ptr := Sloc (Entry_Name);
6298 First_Named : Node_Id;
6305 -- We kill all checks here, because it does not seem worth the effort to
6306 -- do anything better, an entry call is a big operation.
6310 -- Processing of the name is similar for entry calls and protected
6311 -- operation calls. Once the entity is determined, we can complete
6312 -- the resolution of the actuals.
6314 -- The selector may be overloaded, in the case of a protected object
6315 -- with overloaded functions. The type of the context is used for
6318 if Nkind (Entry_Name) = N_Selected_Component
6319 and then Is_Overloaded (Selector_Name (Entry_Name))
6320 and then Typ /= Standard_Void_Type
6327 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6328 while Present (It.Typ) loop
6329 if Covers (Typ, It.Typ) then
6330 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6331 Set_Etype (Entry_Name, It.Typ);
6333 Generate_Reference (It.Typ, N, ' ');
6336 Get_Next_Interp (I, It);
6341 Resolve_Entry (Entry_Name);
6343 if Nkind (Entry_Name) = N_Selected_Component then
6345 -- Simple entry call
6347 Nam := Entity (Selector_Name (Entry_Name));
6348 Obj := Prefix (Entry_Name);
6349 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6351 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6353 -- Call to member of entry family
6355 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6356 Obj := Prefix (Prefix (Entry_Name));
6357 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6360 -- We cannot in general check the maximum depth of protected entry calls
6361 -- at compile time. But we can tell that any protected entry call at all
6362 -- violates a specified nesting depth of zero.
6364 if Is_Protected_Type (Scope (Nam)) then
6365 Check_Restriction (Max_Entry_Queue_Length, N);
6368 -- Use context type to disambiguate a protected function that can be
6369 -- called without actuals and that returns an array type, and where the
6370 -- argument list may be an indexing of the returned value.
6372 if Ekind (Nam) = E_Function
6373 and then Needs_No_Actuals (Nam)
6374 and then Present (Parameter_Associations (N))
6376 ((Is_Array_Type (Etype (Nam))
6377 and then Covers (Typ, Component_Type (Etype (Nam))))
6379 or else (Is_Access_Type (Etype (Nam))
6380 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6384 Component_Type (Designated_Type (Etype (Nam))))))
6387 Index_Node : Node_Id;
6391 Make_Indexed_Component (Loc,
6393 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
6394 Expressions => Parameter_Associations (N));
6396 -- Since we are correcting a node classification error made by the
6397 -- parser, we call Replace rather than Rewrite.
6399 Replace (N, Index_Node);
6400 Set_Etype (Prefix (N), Etype (Nam));
6402 Resolve_Indexed_Component (N, Typ);
6407 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6408 and then Present (PPC_Wrapper (Nam))
6409 and then Current_Scope /= PPC_Wrapper (Nam)
6411 -- Rewrite as call to the precondition wrapper, adding the task
6412 -- object to the list of actuals. If the call is to a member of an
6413 -- entry family, include the index as well.
6417 New_Actuals : List_Id;
6420 New_Actuals := New_List (Obj);
6422 if Nkind (Entry_Name) = N_Indexed_Component then
6423 Append_To (New_Actuals,
6424 New_Copy_Tree (First (Expressions (Entry_Name))));
6427 Append_List (Parameter_Associations (N), New_Actuals);
6429 Make_Procedure_Call_Statement (Loc,
6431 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6432 Parameter_Associations => New_Actuals);
6433 Rewrite (N, New_Call);
6434 Analyze_And_Resolve (N);
6439 -- The operation name may have been overloaded. Order the actuals
6440 -- according to the formals of the resolved entity, and set the return
6441 -- type to that of the operation.
6444 Normalize_Actuals (N, Nam, False, Norm_OK);
6445 pragma Assert (Norm_OK);
6446 Set_Etype (N, Etype (Nam));
6449 Resolve_Actuals (N, Nam);
6451 -- Create a call reference to the entry
6453 Generate_Reference (Nam, Entry_Name, 's');
6455 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
6456 Check_Potentially_Blocking_Operation (N);
6459 -- Verify that a procedure call cannot masquerade as an entry
6460 -- call where an entry call is expected.
6462 if Ekind (Nam) = E_Procedure then
6463 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6464 and then N = Entry_Call_Statement (Parent (N))
6466 Error_Msg_N ("entry call required in select statement", N);
6468 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6469 and then N = Triggering_Statement (Parent (N))
6471 Error_Msg_N ("triggering statement cannot be procedure call", N);
6473 elsif Ekind (Scope (Nam)) = E_Task_Type
6474 and then not In_Open_Scopes (Scope (Nam))
6476 Error_Msg_N ("task has no entry with this name", Entry_Name);
6480 -- After resolution, entry calls and protected procedure calls are
6481 -- changed into entry calls, for expansion. The structure of the node
6482 -- does not change, so it can safely be done in place. Protected
6483 -- function calls must keep their structure because they are
6486 if Ekind (Nam) /= E_Function then
6488 -- A protected operation that is not a function may modify the
6489 -- corresponding object, and cannot apply to a constant. If this
6490 -- is an internal call, the prefix is the type itself.
6492 if Is_Protected_Type (Scope (Nam))
6493 and then not Is_Variable (Obj)
6494 and then (not Is_Entity_Name (Obj)
6495 or else not Is_Type (Entity (Obj)))
6498 ("prefix of protected procedure or entry call must be variable",
6502 Actuals := Parameter_Associations (N);
6503 First_Named := First_Named_Actual (N);
6506 Make_Entry_Call_Statement (Loc,
6508 Parameter_Associations => Actuals));
6510 Set_First_Named_Actual (N, First_Named);
6511 Set_Analyzed (N, True);
6513 -- Protected functions can return on the secondary stack, in which
6514 -- case we must trigger the transient scope mechanism.
6516 elsif Expander_Active
6517 and then Requires_Transient_Scope (Etype (Nam))
6519 Establish_Transient_Scope (N, Sec_Stack => True);
6521 end Resolve_Entry_Call;
6523 -------------------------
6524 -- Resolve_Equality_Op --
6525 -------------------------
6527 -- Both arguments must have the same type, and the boolean context does
6528 -- not participate in the resolution. The first pass verifies that the
6529 -- interpretation is not ambiguous, and the type of the left argument is
6530 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6531 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6532 -- though they carry a single (universal) type. Diagnose this case here.
6534 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6535 L : constant Node_Id := Left_Opnd (N);
6536 R : constant Node_Id := Right_Opnd (N);
6537 T : Entity_Id := Find_Unique_Type (L, R);
6539 procedure Check_Conditional_Expression (Cond : Node_Id);
6540 -- The resolution rule for conditional expressions requires that each
6541 -- such must have a unique type. This means that if several dependent
6542 -- expressions are of a non-null anonymous access type, and the context
6543 -- does not impose an expected type (as can be the case in an equality
6544 -- operation) the expression must be rejected.
6546 function Find_Unique_Access_Type return Entity_Id;
6547 -- In the case of allocators, make a last-ditch attempt to find a single
6548 -- access type with the right designated type. This is semantically
6549 -- dubious, and of no interest to any real code, but c48008a makes it
6552 ----------------------------------
6553 -- Check_Conditional_Expression --
6554 ----------------------------------
6556 procedure Check_Conditional_Expression (Cond : Node_Id) is
6557 Then_Expr : Node_Id;
6558 Else_Expr : Node_Id;
6561 if Nkind (Cond) = N_Conditional_Expression then
6562 Then_Expr := Next (First (Expressions (Cond)));
6563 Else_Expr := Next (Then_Expr);
6565 if Nkind (Then_Expr) /= N_Null
6566 and then Nkind (Else_Expr) /= N_Null
6569 ("cannot determine type of conditional expression", Cond);
6572 end Check_Conditional_Expression;
6574 -----------------------------
6575 -- Find_Unique_Access_Type --
6576 -----------------------------
6578 function Find_Unique_Access_Type return Entity_Id is
6584 if Ekind (Etype (R)) = E_Allocator_Type then
6585 Acc := Designated_Type (Etype (R));
6586 elsif Ekind (Etype (L)) = E_Allocator_Type then
6587 Acc := Designated_Type (Etype (L));
6593 while S /= Standard_Standard loop
6594 E := First_Entity (S);
6595 while Present (E) loop
6597 and then Is_Access_Type (E)
6598 and then Ekind (E) /= E_Allocator_Type
6599 and then Designated_Type (E) = Base_Type (Acc)
6611 end Find_Unique_Access_Type;
6613 -- Start of processing for Resolve_Equality_Op
6616 Set_Etype (N, Base_Type (Typ));
6617 Generate_Reference (T, N, ' ');
6619 if T = Any_Fixed then
6620 T := Unique_Fixed_Point_Type (L);
6623 if T /= Any_Type then
6624 if T = Any_String or else
6625 T = Any_Composite or else
6628 if T = Any_Character then
6629 Ambiguous_Character (L);
6631 Error_Msg_N ("ambiguous operands for equality", N);
6634 Set_Etype (N, Any_Type);
6637 elsif T = Any_Access
6638 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
6640 T := Find_Unique_Access_Type;
6643 Error_Msg_N ("ambiguous operands for equality", N);
6644 Set_Etype (N, Any_Type);
6648 -- Conditional expressions must have a single type, and if the
6649 -- context does not impose one the dependent expressions cannot
6650 -- be anonymous access types.
6652 elsif Ada_Version >= Ada_2012
6653 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
6654 E_Anonymous_Access_Subprogram_Type)
6655 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
6656 E_Anonymous_Access_Subprogram_Type)
6658 Check_Conditional_Expression (L);
6659 Check_Conditional_Expression (R);
6665 -- In SPARK, equality operators = and /= for array types other than
6666 -- String are only defined when, for each index position, the
6667 -- operands have equal static bounds.
6669 if Is_Array_Type (T) then
6670 Mark_Non_ALFA_Subprogram
6671 ("equality operator on array is not in ALFA", N);
6673 -- Protect call to Matching_Static_Array_Bounds to avoid costly
6674 -- operation if not needed.
6676 if Restriction_Check_Required (SPARK)
6677 and then Base_Type (T) /= Standard_String
6678 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6679 and then Etype (L) /= Any_Composite -- or else L in error
6680 and then Etype (R) /= Any_Composite -- or else R in error
6681 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
6683 Check_SPARK_Restriction
6684 ("array types should have matching static bounds", N);
6688 -- If the unique type is a class-wide type then it will be expanded
6689 -- into a dispatching call to the predefined primitive. Therefore we
6690 -- check here for potential violation of such restriction.
6692 if Is_Class_Wide_Type (T) then
6693 Check_Restriction (No_Dispatching_Calls, N);
6696 if Warn_On_Redundant_Constructs
6697 and then Comes_From_Source (N)
6698 and then Is_Entity_Name (R)
6699 and then Entity (R) = Standard_True
6700 and then Comes_From_Source (R)
6702 Error_Msg_N -- CODEFIX
6703 ("?comparison with True is redundant!", R);
6706 Check_Unset_Reference (L);
6707 Check_Unset_Reference (R);
6708 Generate_Operator_Reference (N, T);
6709 Check_Low_Bound_Tested (N);
6711 -- If this is an inequality, it may be the implicit inequality
6712 -- created for a user-defined operation, in which case the corres-
6713 -- ponding equality operation is not intrinsic, and the operation
6714 -- cannot be constant-folded. Else fold.
6716 if Nkind (N) = N_Op_Eq
6717 or else Comes_From_Source (Entity (N))
6718 or else Ekind (Entity (N)) = E_Operator
6719 or else Is_Intrinsic_Subprogram
6720 (Corresponding_Equality (Entity (N)))
6722 Eval_Relational_Op (N);
6724 elsif Nkind (N) = N_Op_Ne
6725 and then Is_Abstract_Subprogram (Entity (N))
6727 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6730 -- Ada 2005: If one operand is an anonymous access type, convert the
6731 -- other operand to it, to ensure that the underlying types match in
6732 -- the back-end. Same for access_to_subprogram, and the conversion
6733 -- verifies that the types are subtype conformant.
6735 -- We apply the same conversion in the case one of the operands is a
6736 -- private subtype of the type of the other.
6738 -- Why the Expander_Active test here ???
6742 (Ekind_In (T, E_Anonymous_Access_Type,
6743 E_Anonymous_Access_Subprogram_Type)
6744 or else Is_Private_Type (T))
6746 if Etype (L) /= T then
6748 Make_Unchecked_Type_Conversion (Sloc (L),
6749 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6750 Expression => Relocate_Node (L)));
6751 Analyze_And_Resolve (L, T);
6754 if (Etype (R)) /= T then
6756 Make_Unchecked_Type_Conversion (Sloc (R),
6757 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6758 Expression => Relocate_Node (R)));
6759 Analyze_And_Resolve (R, T);
6763 end Resolve_Equality_Op;
6765 ----------------------------------
6766 -- Resolve_Explicit_Dereference --
6767 ----------------------------------
6769 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6770 Loc : constant Source_Ptr := Sloc (N);
6772 P : constant Node_Id := Prefix (N);
6777 Check_Fully_Declared_Prefix (Typ, P);
6779 if Is_Overloaded (P) then
6781 -- Use the context type to select the prefix that has the correct
6784 Get_First_Interp (P, I, It);
6785 while Present (It.Typ) loop
6786 exit when Is_Access_Type (It.Typ)
6787 and then Covers (Typ, Designated_Type (It.Typ));
6788 Get_Next_Interp (I, It);
6791 if Present (It.Typ) then
6792 Resolve (P, It.Typ);
6794 -- If no interpretation covers the designated type of the prefix,
6795 -- this is the pathological case where not all implementations of
6796 -- the prefix allow the interpretation of the node as a call. Now
6797 -- that the expected type is known, Remove other interpretations
6798 -- from prefix, rewrite it as a call, and resolve again, so that
6799 -- the proper call node is generated.
6801 Get_First_Interp (P, I, It);
6802 while Present (It.Typ) loop
6803 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6807 Get_Next_Interp (I, It);
6811 Make_Function_Call (Loc,
6813 Make_Explicit_Dereference (Loc,
6815 Parameter_Associations => New_List);
6817 Save_Interps (N, New_N);
6819 Analyze_And_Resolve (N, Typ);
6823 Set_Etype (N, Designated_Type (It.Typ));
6829 if Is_Access_Type (Etype (P)) then
6830 Apply_Access_Check (N);
6833 -- If the designated type is a packed unconstrained array type, and the
6834 -- explicit dereference is not in the context of an attribute reference,
6835 -- then we must compute and set the actual subtype, since it is needed
6836 -- by Gigi. The reason we exclude the attribute case is that this is
6837 -- handled fine by Gigi, and in fact we use such attributes to build the
6838 -- actual subtype. We also exclude generated code (which builds actual
6839 -- subtypes directly if they are needed).
6841 if Is_Array_Type (Etype (N))
6842 and then Is_Packed (Etype (N))
6843 and then not Is_Constrained (Etype (N))
6844 and then Nkind (Parent (N)) /= N_Attribute_Reference
6845 and then Comes_From_Source (N)
6847 Set_Etype (N, Get_Actual_Subtype (N));
6850 -- Note: No Eval processing is required for an explicit dereference,
6851 -- because such a name can never be static.
6853 end Resolve_Explicit_Dereference;
6855 -------------------------------------
6856 -- Resolve_Expression_With_Actions --
6857 -------------------------------------
6859 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
6862 end Resolve_Expression_With_Actions;
6864 -------------------------------
6865 -- Resolve_Indexed_Component --
6866 -------------------------------
6868 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6869 Name : constant Node_Id := Prefix (N);
6871 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6875 if Is_Overloaded (Name) then
6877 -- Use the context type to select the prefix that yields the correct
6883 I1 : Interp_Index := 0;
6884 P : constant Node_Id := Prefix (N);
6885 Found : Boolean := False;
6888 Get_First_Interp (P, I, It);
6889 while Present (It.Typ) loop
6890 if (Is_Array_Type (It.Typ)
6891 and then Covers (Typ, Component_Type (It.Typ)))
6892 or else (Is_Access_Type (It.Typ)
6893 and then Is_Array_Type (Designated_Type (It.Typ))
6897 Component_Type (Designated_Type (It.Typ))))
6900 It := Disambiguate (P, I1, I, Any_Type);
6902 if It = No_Interp then
6903 Error_Msg_N ("ambiguous prefix for indexing", N);
6909 Array_Type := It.Typ;
6915 Array_Type := It.Typ;
6920 Get_Next_Interp (I, It);
6925 Array_Type := Etype (Name);
6928 Resolve (Name, Array_Type);
6929 Array_Type := Get_Actual_Subtype_If_Available (Name);
6931 -- If prefix is access type, dereference to get real array type.
6932 -- Note: we do not apply an access check because the expander always
6933 -- introduces an explicit dereference, and the check will happen there.
6935 if Is_Access_Type (Array_Type) then
6936 Array_Type := Designated_Type (Array_Type);
6939 -- If name was overloaded, set component type correctly now
6940 -- If a misplaced call to an entry family (which has no index types)
6941 -- return. Error will be diagnosed from calling context.
6943 if Is_Array_Type (Array_Type) then
6944 Set_Etype (N, Component_Type (Array_Type));
6949 Index := First_Index (Array_Type);
6950 Expr := First (Expressions (N));
6952 -- The prefix may have resolved to a string literal, in which case its
6953 -- etype has a special representation. This is only possible currently
6954 -- if the prefix is a static concatenation, written in functional
6957 if Ekind (Array_Type) = E_String_Literal_Subtype then
6958 Resolve (Expr, Standard_Positive);
6961 while Present (Index) and Present (Expr) loop
6962 Resolve (Expr, Etype (Index));
6963 Check_Unset_Reference (Expr);
6965 if Is_Scalar_Type (Etype (Expr)) then
6966 Apply_Scalar_Range_Check (Expr, Etype (Index));
6968 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6976 -- Do not generate the warning on suspicious index if we are analyzing
6977 -- package Ada.Tags; otherwise we will report the warning with the
6978 -- Prims_Ptr field of the dispatch table.
6980 if Scope (Etype (Prefix (N))) = Standard_Standard
6982 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6985 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6986 Eval_Indexed_Component (N);
6989 -- If the array type is atomic, and is packed, and we are in a left side
6990 -- context, then this is worth a warning, since we have a situation
6991 -- where the access to the component may cause extra read/writes of
6992 -- the atomic array object, which could be considered unexpected.
6994 if Nkind (N) = N_Indexed_Component
6995 and then (Is_Atomic (Array_Type)
6996 or else (Is_Entity_Name (Prefix (N))
6997 and then Is_Atomic (Entity (Prefix (N)))))
6998 and then Is_Bit_Packed_Array (Array_Type)
7001 Error_Msg_N ("?assignment to component of packed atomic array",
7003 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
7006 end Resolve_Indexed_Component;
7008 -----------------------------
7009 -- Resolve_Integer_Literal --
7010 -----------------------------
7012 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7015 Eval_Integer_Literal (N);
7016 end Resolve_Integer_Literal;
7018 --------------------------------
7019 -- Resolve_Intrinsic_Operator --
7020 --------------------------------
7022 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
7023 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7025 Orig_Op : constant Entity_Id := Entity (N);
7030 -- We must preserve the original entity in a generic setting, so that
7031 -- the legality of the operation can be verified in an instance.
7033 if not Expander_Active then
7038 while Scope (Op) /= Standard_Standard loop
7040 pragma Assert (Present (Op));
7044 Set_Is_Overloaded (N, False);
7046 -- If the operand type is private, rewrite with suitable conversions on
7047 -- the operands and the result, to expose the proper underlying numeric
7050 if Is_Private_Type (Typ) then
7051 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
7053 if Nkind (N) = N_Op_Expon then
7054 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7056 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7059 if Nkind (Arg1) = N_Type_Conversion then
7060 Save_Interps (Left_Opnd (N), Expression (Arg1));
7063 if Nkind (Arg2) = N_Type_Conversion then
7064 Save_Interps (Right_Opnd (N), Expression (Arg2));
7067 Set_Left_Opnd (N, Arg1);
7068 Set_Right_Opnd (N, Arg2);
7070 Set_Etype (N, Btyp);
7071 Rewrite (N, Unchecked_Convert_To (Typ, N));
7074 elsif Typ /= Etype (Left_Opnd (N))
7075 or else Typ /= Etype (Right_Opnd (N))
7077 -- Add explicit conversion where needed, and save interpretations in
7078 -- case operands are overloaded. If the context is a VMS operation,
7079 -- assert that the conversion is legal (the operands have the proper
7080 -- types to select the VMS intrinsic). Note that in rare cases the
7081 -- VMS operators may be visible, but the default System is being used
7082 -- and Address is a private type.
7084 Arg1 := Convert_To (Typ, Left_Opnd (N));
7085 Arg2 := Convert_To (Typ, Right_Opnd (N));
7087 if Nkind (Arg1) = N_Type_Conversion then
7088 Save_Interps (Left_Opnd (N), Expression (Arg1));
7090 if Is_VMS_Operator (Orig_Op) then
7091 Set_Conversion_OK (Arg1);
7094 Save_Interps (Left_Opnd (N), Arg1);
7097 if Nkind (Arg2) = N_Type_Conversion then
7098 Save_Interps (Right_Opnd (N), Expression (Arg2));
7100 if Is_VMS_Operator (Orig_Op) then
7101 Set_Conversion_OK (Arg2);
7104 Save_Interps (Right_Opnd (N), Arg2);
7107 Rewrite (Left_Opnd (N), Arg1);
7108 Rewrite (Right_Opnd (N), Arg2);
7111 Resolve_Arithmetic_Op (N, Typ);
7114 Resolve_Arithmetic_Op (N, Typ);
7116 end Resolve_Intrinsic_Operator;
7118 --------------------------------------
7119 -- Resolve_Intrinsic_Unary_Operator --
7120 --------------------------------------
7122 procedure Resolve_Intrinsic_Unary_Operator
7126 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7132 while Scope (Op) /= Standard_Standard loop
7134 pragma Assert (Present (Op));
7139 if Is_Private_Type (Typ) then
7140 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7141 Save_Interps (Right_Opnd (N), Expression (Arg2));
7143 Set_Right_Opnd (N, Arg2);
7145 Set_Etype (N, Btyp);
7146 Rewrite (N, Unchecked_Convert_To (Typ, N));
7150 Resolve_Unary_Op (N, Typ);
7152 end Resolve_Intrinsic_Unary_Operator;
7154 ------------------------
7155 -- Resolve_Logical_Op --
7156 ------------------------
7158 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7162 Check_No_Direct_Boolean_Operators (N);
7164 -- Predefined operations on scalar types yield the base type. On the
7165 -- other hand, logical operations on arrays yield the type of the
7166 -- arguments (and the context).
7168 if Is_Array_Type (Typ) then
7171 B_Typ := Base_Type (Typ);
7174 -- OK if this is a VMS-specific intrinsic operation
7176 if Is_VMS_Operator (Entity (N)) then
7179 -- The following test is required because the operands of the operation
7180 -- may be literals, in which case the resulting type appears to be
7181 -- compatible with a signed integer type, when in fact it is compatible
7182 -- only with modular types. If the context itself is universal, the
7183 -- operation is illegal.
7185 elsif not Valid_Boolean_Arg (Typ) then
7186 Error_Msg_N ("invalid context for logical operation", N);
7187 Set_Etype (N, Any_Type);
7190 elsif Typ = Any_Modular then
7192 ("no modular type available in this context", N);
7193 Set_Etype (N, Any_Type);
7196 elsif Is_Modular_Integer_Type (Typ)
7197 and then Etype (Left_Opnd (N)) = Universal_Integer
7198 and then Etype (Right_Opnd (N)) = Universal_Integer
7200 Check_For_Visible_Operator (N, B_Typ);
7203 Resolve (Left_Opnd (N), B_Typ);
7204 Resolve (Right_Opnd (N), B_Typ);
7206 Check_Unset_Reference (Left_Opnd (N));
7207 Check_Unset_Reference (Right_Opnd (N));
7209 Set_Etype (N, B_Typ);
7210 Generate_Operator_Reference (N, B_Typ);
7211 Eval_Logical_Op (N);
7213 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
7214 -- only when both operands have same static lower and higher bounds. Of
7215 -- course the types have to match, so only check if operands are
7216 -- compatible and the node itself has no errors.
7218 if Is_Array_Type (B_Typ)
7219 and then Nkind (N) in N_Binary_Op
7221 Mark_Non_ALFA_Subprogram
7222 ("binary operator on array is not in ALFA", N);
7225 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
7226 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
7228 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7229 -- operation if not needed.
7231 if Restriction_Check_Required (SPARK)
7232 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
7233 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
7234 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
7235 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
7237 Check_SPARK_Restriction
7238 ("array types should have matching static bounds", N);
7242 end Resolve_Logical_Op;
7244 ---------------------------
7245 -- Resolve_Membership_Op --
7246 ---------------------------
7248 -- The context can only be a boolean type, and does not determine the
7249 -- arguments. Arguments should be unambiguous, but the preference rule for
7250 -- universal types applies.
7252 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
7253 pragma Warnings (Off, Typ);
7255 L : constant Node_Id := Left_Opnd (N);
7256 R : constant Node_Id := Right_Opnd (N);
7259 procedure Resolve_Set_Membership;
7260 -- Analysis has determined a unique type for the left operand. Use it to
7261 -- resolve the disjuncts.
7263 ----------------------------
7264 -- Resolve_Set_Membership --
7265 ----------------------------
7267 procedure Resolve_Set_Membership is
7271 Resolve (L, Etype (L));
7273 Alt := First (Alternatives (N));
7274 while Present (Alt) loop
7276 -- Alternative is an expression, a range
7277 -- or a subtype mark.
7279 if not Is_Entity_Name (Alt)
7280 or else not Is_Type (Entity (Alt))
7282 Resolve (Alt, Etype (L));
7287 end Resolve_Set_Membership;
7289 -- Start of processing for Resolve_Membership_Op
7292 if L = Error or else R = Error then
7296 if Present (Alternatives (N)) then
7297 Resolve_Set_Membership;
7300 elsif not Is_Overloaded (R)
7302 (Etype (R) = Universal_Integer
7304 Etype (R) = Universal_Real)
7305 and then Is_Overloaded (L)
7309 -- Ada 2005 (AI-251): Support the following case:
7311 -- type I is interface;
7312 -- type T is tagged ...
7314 -- function Test (O : I'Class) is
7316 -- return O in T'Class.
7319 -- In this case we have nothing else to do. The membership test will be
7320 -- done at run time.
7322 elsif Ada_Version >= Ada_2005
7323 and then Is_Class_Wide_Type (Etype (L))
7324 and then Is_Interface (Etype (L))
7325 and then Is_Class_Wide_Type (Etype (R))
7326 and then not Is_Interface (Etype (R))
7330 T := Intersect_Types (L, R);
7333 -- If mixed-mode operations are present and operands are all literal,
7334 -- the only interpretation involves Duration, which is probably not
7335 -- the intention of the programmer.
7337 if T = Any_Fixed then
7338 T := Unique_Fixed_Point_Type (N);
7340 if T = Any_Type then
7346 Check_Unset_Reference (L);
7348 if Nkind (R) = N_Range
7349 and then not Is_Scalar_Type (T)
7351 Error_Msg_N ("scalar type required for range", R);
7354 if Is_Entity_Name (R) then
7355 Freeze_Expression (R);
7358 Check_Unset_Reference (R);
7361 Eval_Membership_Op (N);
7362 end Resolve_Membership_Op;
7368 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
7369 Loc : constant Source_Ptr := Sloc (N);
7372 -- Handle restriction against anonymous null access values This
7373 -- restriction can be turned off using -gnatdj.
7375 -- Ada 2005 (AI-231): Remove restriction
7377 if Ada_Version < Ada_2005
7378 and then not Debug_Flag_J
7379 and then Ekind (Typ) = E_Anonymous_Access_Type
7380 and then Comes_From_Source (N)
7382 -- In the common case of a call which uses an explicitly null value
7383 -- for an access parameter, give specialized error message.
7385 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
7389 ("null is not allowed as argument for an access parameter", N);
7391 -- Standard message for all other cases (are there any?)
7395 ("null cannot be of an anonymous access type", N);
7399 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7400 -- assignment to a null-excluding object
7402 if Ada_Version >= Ada_2005
7403 and then Can_Never_Be_Null (Typ)
7404 and then Nkind (Parent (N)) = N_Assignment_Statement
7406 if not Inside_Init_Proc then
7408 (Compile_Time_Constraint_Error (N,
7409 "(Ada 2005) null not allowed in null-excluding objects?"),
7410 Make_Raise_Constraint_Error (Loc,
7411 Reason => CE_Access_Check_Failed));
7414 Make_Raise_Constraint_Error (Loc,
7415 Reason => CE_Access_Check_Failed));
7419 -- In a distributed context, null for a remote access to subprogram may
7420 -- need to be replaced with a special record aggregate. In this case,
7421 -- return after having done the transformation.
7423 if (Ekind (Typ) = E_Record_Type
7424 or else Is_Remote_Access_To_Subprogram_Type (Typ))
7425 and then Remote_AST_Null_Value (N, Typ)
7430 -- The null literal takes its type from the context
7435 -----------------------
7436 -- Resolve_Op_Concat --
7437 -----------------------
7439 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
7441 -- We wish to avoid deep recursion, because concatenations are often
7442 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
7443 -- operands nonrecursively until we find something that is not a simple
7444 -- concatenation (A in this case). We resolve that, and then walk back
7445 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
7446 -- to do the rest of the work at each level. The Parent pointers allow
7447 -- us to avoid recursion, and thus avoid running out of memory. See also
7448 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
7454 -- The following code is equivalent to:
7456 -- Resolve_Op_Concat_First (NN, Typ);
7457 -- Resolve_Op_Concat_Arg (N, ...);
7458 -- Resolve_Op_Concat_Rest (N, Typ);
7460 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
7461 -- operand is a concatenation.
7463 -- Walk down left operands
7466 Resolve_Op_Concat_First (NN, Typ);
7467 Op1 := Left_Opnd (NN);
7468 exit when not (Nkind (Op1) = N_Op_Concat
7469 and then not Is_Array_Type (Component_Type (Typ))
7470 and then Entity (Op1) = Entity (NN));
7474 -- Now (given the above example) NN is A&B and Op1 is A
7476 -- First resolve Op1 ...
7478 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7480 -- ... then walk NN back up until we reach N (where we started), calling
7481 -- Resolve_Op_Concat_Rest along the way.
7484 Resolve_Op_Concat_Rest (NN, Typ);
7489 if Base_Type (Etype (N)) /= Standard_String then
7490 Check_SPARK_Restriction
7491 ("result of concatenation should have type String", N);
7493 end Resolve_Op_Concat;
7495 ---------------------------
7496 -- Resolve_Op_Concat_Arg --
7497 ---------------------------
7499 procedure Resolve_Op_Concat_Arg
7505 Btyp : constant Entity_Id := Base_Type (Typ);
7506 Ctyp : constant Entity_Id := Component_Type (Typ);
7511 or else (not Is_Overloaded (Arg)
7512 and then Etype (Arg) /= Any_Composite
7513 and then Covers (Ctyp, Etype (Arg)))
7515 Resolve (Arg, Ctyp);
7517 Resolve (Arg, Btyp);
7520 -- If both Array & Array and Array & Component are visible, there is a
7521 -- potential ambiguity that must be reported.
7523 elsif Has_Compatible_Type (Arg, Ctyp) then
7524 if Nkind (Arg) = N_Aggregate
7525 and then Is_Composite_Type (Ctyp)
7527 if Is_Private_Type (Ctyp) then
7528 Resolve (Arg, Btyp);
7530 -- If the operation is user-defined and not overloaded use its
7531 -- profile. The operation may be a renaming, in which case it has
7532 -- been rewritten, and we want the original profile.
7534 elsif not Is_Overloaded (N)
7535 and then Comes_From_Source (Entity (Original_Node (N)))
7536 and then Ekind (Entity (Original_Node (N))) = E_Function
7540 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
7543 -- Otherwise an aggregate may match both the array type and the
7547 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7548 Set_Etype (Arg, Any_Type);
7552 if Is_Overloaded (Arg)
7553 and then Has_Compatible_Type (Arg, Typ)
7554 and then Etype (Arg) /= Any_Type
7562 Get_First_Interp (Arg, I, It);
7564 Get_Next_Interp (I, It);
7566 -- Special-case the error message when the overloading is
7567 -- caused by a function that yields an array and can be
7568 -- called without parameters.
7570 if It.Nam = Func then
7571 Error_Msg_Sloc := Sloc (Func);
7572 Error_Msg_N ("ambiguous call to function#", Arg);
7574 ("\\interpretation as call yields&", Arg, Typ);
7576 ("\\interpretation as indexing of call yields&",
7577 Arg, Component_Type (Typ));
7580 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
7582 Get_First_Interp (Arg, I, It);
7583 while Present (It.Nam) loop
7584 Error_Msg_Sloc := Sloc (It.Nam);
7586 if Base_Type (It.Typ) = Btyp
7588 Base_Type (It.Typ) = Base_Type (Ctyp)
7590 Error_Msg_N -- CODEFIX
7591 ("\\possible interpretation#", Arg);
7594 Get_Next_Interp (I, It);
7600 Resolve (Arg, Component_Type (Typ));
7602 if Nkind (Arg) = N_String_Literal then
7603 Set_Etype (Arg, Component_Type (Typ));
7606 if Arg = Left_Opnd (N) then
7607 Set_Is_Component_Left_Opnd (N);
7609 Set_Is_Component_Right_Opnd (N);
7614 Resolve (Arg, Btyp);
7617 -- Concatenation is restricted in SPARK: each operand must be either a
7618 -- string literal, the name of a string constant, a static character or
7619 -- string expression, or another concatenation. Arg cannot be a
7620 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
7621 -- separately on each final operand, past concatenation operations.
7623 if Is_Character_Type (Etype (Arg)) then
7624 if not Is_Static_Expression (Arg) then
7625 Check_SPARK_Restriction
7626 ("character operand for concatenation should be static", N);
7629 elsif Is_String_Type (Etype (Arg)) then
7630 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
7631 and then Is_Constant_Object (Entity (Arg)))
7632 and then not Is_Static_Expression (Arg)
7634 Check_SPARK_Restriction
7635 ("string operand for concatenation should be static", N);
7638 -- Do not issue error on an operand that is neither a character nor a
7639 -- string, as the error is issued in Resolve_Op_Concat.
7645 Check_Unset_Reference (Arg);
7646 end Resolve_Op_Concat_Arg;
7648 -----------------------------
7649 -- Resolve_Op_Concat_First --
7650 -----------------------------
7652 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7653 Btyp : constant Entity_Id := Base_Type (Typ);
7654 Op1 : constant Node_Id := Left_Opnd (N);
7655 Op2 : constant Node_Id := Right_Opnd (N);
7658 -- The parser folds an enormous sequence of concatenations of string
7659 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7660 -- in the right operand. If the expression resolves to a predefined "&"
7661 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7662 -- we give an error. See P_Simple_Expression in Par.Ch4.
7664 if Nkind (Op2) = N_String_Literal
7665 and then Is_Folded_In_Parser (Op2)
7666 and then Ekind (Entity (N)) = E_Function
7668 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7669 and then String_Length (Strval (Op1)) = 0);
7670 Error_Msg_N ("too many user-defined concatenations", N);
7674 Set_Etype (N, Btyp);
7676 if Is_Limited_Composite (Btyp) then
7677 Error_Msg_N ("concatenation not available for limited array", N);
7678 Explain_Limited_Type (Btyp, N);
7680 end Resolve_Op_Concat_First;
7682 ----------------------------
7683 -- Resolve_Op_Concat_Rest --
7684 ----------------------------
7686 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7687 Op1 : constant Node_Id := Left_Opnd (N);
7688 Op2 : constant Node_Id := Right_Opnd (N);
7691 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7693 Generate_Operator_Reference (N, Typ);
7695 if Is_String_Type (Typ) then
7696 Eval_Concatenation (N);
7699 -- If this is not a static concatenation, but the result is a string
7700 -- type (and not an array of strings) ensure that static string operands
7701 -- have their subtypes properly constructed.
7703 if Nkind (N) /= N_String_Literal
7704 and then Is_Character_Type (Component_Type (Typ))
7706 Set_String_Literal_Subtype (Op1, Typ);
7707 Set_String_Literal_Subtype (Op2, Typ);
7709 end Resolve_Op_Concat_Rest;
7711 ----------------------
7712 -- Resolve_Op_Expon --
7713 ----------------------
7715 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7716 B_Typ : constant Entity_Id := Base_Type (Typ);
7719 -- Catch attempts to do fixed-point exponentiation with universal
7720 -- operands, which is a case where the illegality is not caught during
7721 -- normal operator analysis.
7723 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7724 Error_Msg_N ("exponentiation not available for fixed point", N);
7728 if Comes_From_Source (N)
7729 and then Ekind (Entity (N)) = E_Function
7730 and then Is_Imported (Entity (N))
7731 and then Is_Intrinsic_Subprogram (Entity (N))
7733 Resolve_Intrinsic_Operator (N, Typ);
7737 if Etype (Left_Opnd (N)) = Universal_Integer
7738 or else Etype (Left_Opnd (N)) = Universal_Real
7740 Check_For_Visible_Operator (N, B_Typ);
7743 -- We do the resolution using the base type, because intermediate values
7744 -- in expressions always are of the base type, not a subtype of it.
7746 Resolve (Left_Opnd (N), B_Typ);
7747 Resolve (Right_Opnd (N), Standard_Integer);
7749 Check_Unset_Reference (Left_Opnd (N));
7750 Check_Unset_Reference (Right_Opnd (N));
7752 Set_Etype (N, B_Typ);
7753 Generate_Operator_Reference (N, B_Typ);
7756 -- Set overflow checking bit. Much cleverer code needed here eventually
7757 -- and perhaps the Resolve routines should be separated for the various
7758 -- arithmetic operations, since they will need different processing. ???
7760 if Nkind (N) in N_Op then
7761 if not Overflow_Checks_Suppressed (Etype (N)) then
7762 Enable_Overflow_Check (N);
7765 end Resolve_Op_Expon;
7767 --------------------
7768 -- Resolve_Op_Not --
7769 --------------------
7771 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7774 function Parent_Is_Boolean return Boolean;
7775 -- This function determines if the parent node is a boolean operator or
7776 -- operation (comparison op, membership test, or short circuit form) and
7777 -- the not in question is the left operand of this operation. Note that
7778 -- if the not is in parens, then false is returned.
7780 -----------------------
7781 -- Parent_Is_Boolean --
7782 -----------------------
7784 function Parent_Is_Boolean return Boolean is
7786 if Paren_Count (N) /= 0 then
7790 case Nkind (Parent (N)) is
7805 return Left_Opnd (Parent (N)) = N;
7811 end Parent_Is_Boolean;
7813 -- Start of processing for Resolve_Op_Not
7816 -- Predefined operations on scalar types yield the base type. On the
7817 -- other hand, logical operations on arrays yield the type of the
7818 -- arguments (and the context).
7820 if Is_Array_Type (Typ) then
7823 B_Typ := Base_Type (Typ);
7826 if Is_VMS_Operator (Entity (N)) then
7829 -- Straightforward case of incorrect arguments
7831 elsif not Valid_Boolean_Arg (Typ) then
7832 Error_Msg_N ("invalid operand type for operator&", N);
7833 Set_Etype (N, Any_Type);
7836 -- Special case of probable missing parens
7838 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7839 if Parent_Is_Boolean then
7841 ("operand of not must be enclosed in parentheses",
7845 ("no modular type available in this context", N);
7848 Set_Etype (N, Any_Type);
7851 -- OK resolution of NOT
7854 -- Warn if non-boolean types involved. This is a case like not a < b
7855 -- where a and b are modular, where we will get (not a) < b and most
7856 -- likely not (a < b) was intended.
7858 if Warn_On_Questionable_Missing_Parens
7859 and then not Is_Boolean_Type (Typ)
7860 and then Parent_Is_Boolean
7862 Error_Msg_N ("?not expression should be parenthesized here!", N);
7865 -- Warn on double negation if checking redundant constructs
7867 if Warn_On_Redundant_Constructs
7868 and then Comes_From_Source (N)
7869 and then Comes_From_Source (Right_Opnd (N))
7870 and then Root_Type (Typ) = Standard_Boolean
7871 and then Nkind (Right_Opnd (N)) = N_Op_Not
7873 Error_Msg_N ("redundant double negation?", N);
7876 -- Complete resolution and evaluation of NOT
7878 Resolve (Right_Opnd (N), B_Typ);
7879 Check_Unset_Reference (Right_Opnd (N));
7880 Set_Etype (N, B_Typ);
7881 Generate_Operator_Reference (N, B_Typ);
7886 -----------------------------
7887 -- Resolve_Operator_Symbol --
7888 -----------------------------
7890 -- Nothing to be done, all resolved already
7892 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7893 pragma Warnings (Off, N);
7894 pragma Warnings (Off, Typ);
7898 end Resolve_Operator_Symbol;
7900 ----------------------------------
7901 -- Resolve_Qualified_Expression --
7902 ----------------------------------
7904 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7905 pragma Warnings (Off, Typ);
7907 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7908 Expr : constant Node_Id := Expression (N);
7911 Resolve (Expr, Target_Typ);
7913 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7914 -- operation if not needed.
7916 if Restriction_Check_Required (SPARK)
7917 and then Is_Array_Type (Target_Typ)
7918 and then Is_Array_Type (Etype (Expr))
7919 and then Etype (Expr) /= Any_Composite -- or else Expr in error
7920 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
7922 Check_SPARK_Restriction
7923 ("array types should have matching static bounds", N);
7926 -- A qualified expression requires an exact match of the type, class-
7927 -- wide matching is not allowed. However, if the qualifying type is
7928 -- specific and the expression has a class-wide type, it may still be
7929 -- okay, since it can be the result of the expansion of a call to a
7930 -- dispatching function, so we also have to check class-wideness of the
7931 -- type of the expression's original node.
7933 if (Is_Class_Wide_Type (Target_Typ)
7935 (Is_Class_Wide_Type (Etype (Expr))
7936 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7937 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7939 Wrong_Type (Expr, Target_Typ);
7942 -- If the target type is unconstrained, then we reset the type of the
7943 -- result from the type of the expression. For other cases, the actual
7944 -- subtype of the expression is the target type.
7946 if Is_Composite_Type (Target_Typ)
7947 and then not Is_Constrained (Target_Typ)
7949 Set_Etype (N, Etype (Expr));
7952 Eval_Qualified_Expression (N);
7953 end Resolve_Qualified_Expression;
7955 -----------------------------------
7956 -- Resolve_Quantified_Expression --
7957 -----------------------------------
7959 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id) is
7961 -- The loop structure is already resolved during its analysis, only the
7962 -- resolution of the condition needs to be done. Expansion is disabled
7963 -- so that checks and other generated code are inserted in the tree
7964 -- after expression has been rewritten as a loop.
7966 Expander_Mode_Save_And_Set (False);
7967 Resolve (Condition (N), Typ);
7968 Expander_Mode_Restore;
7969 end Resolve_Quantified_Expression;
7975 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7976 L : constant Node_Id := Low_Bound (N);
7977 H : constant Node_Id := High_Bound (N);
7979 function First_Last_Ref return Boolean;
7980 -- Returns True if N is of the form X'First .. X'Last where X is the
7981 -- same entity for both attributes.
7983 --------------------
7984 -- First_Last_Ref --
7985 --------------------
7987 function First_Last_Ref return Boolean is
7988 Lorig : constant Node_Id := Original_Node (L);
7989 Horig : constant Node_Id := Original_Node (H);
7992 if Nkind (Lorig) = N_Attribute_Reference
7993 and then Nkind (Horig) = N_Attribute_Reference
7994 and then Attribute_Name (Lorig) = Name_First
7995 and then Attribute_Name (Horig) = Name_Last
7998 PL : constant Node_Id := Prefix (Lorig);
7999 PH : constant Node_Id := Prefix (Horig);
8001 if Is_Entity_Name (PL)
8002 and then Is_Entity_Name (PH)
8003 and then Entity (PL) = Entity (PH)
8013 -- Start of processing for Resolve_Range
8020 -- Check for inappropriate range on unordered enumeration type
8022 if Bad_Unordered_Enumeration_Reference (N, Typ)
8024 -- Exclude X'First .. X'Last if X is the same entity for both
8026 and then not First_Last_Ref
8028 Error_Msg ("subrange of unordered enumeration type?", Sloc (N));
8031 Check_Unset_Reference (L);
8032 Check_Unset_Reference (H);
8034 -- We have to check the bounds for being within the base range as
8035 -- required for a non-static context. Normally this is automatic and
8036 -- done as part of evaluating expressions, but the N_Range node is an
8037 -- exception, since in GNAT we consider this node to be a subexpression,
8038 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8039 -- this, but that would put the test on the main evaluation path for
8042 Check_Non_Static_Context (L);
8043 Check_Non_Static_Context (H);
8045 -- Check for an ambiguous range over character literals. This will
8046 -- happen with a membership test involving only literals.
8048 if Typ = Any_Character then
8049 Ambiguous_Character (L);
8050 Set_Etype (N, Any_Type);
8054 -- If bounds are static, constant-fold them, so size computations are
8055 -- identical between front-end and back-end. Do not perform this
8056 -- transformation while analyzing generic units, as type information
8057 -- would be lost when reanalyzing the constant node in the instance.
8059 if Is_Discrete_Type (Typ) and then Expander_Active then
8060 if Is_OK_Static_Expression (L) then
8061 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8064 if Is_OK_Static_Expression (H) then
8065 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8070 --------------------------
8071 -- Resolve_Real_Literal --
8072 --------------------------
8074 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8075 Actual_Typ : constant Entity_Id := Etype (N);
8078 -- Special processing for fixed-point literals to make sure that the
8079 -- value is an exact multiple of small where this is required. We skip
8080 -- this for the universal real case, and also for generic types.
8082 if Is_Fixed_Point_Type (Typ)
8083 and then Typ /= Universal_Fixed
8084 and then Typ /= Any_Fixed
8085 and then not Is_Generic_Type (Typ)
8088 Val : constant Ureal := Realval (N);
8089 Cintr : constant Ureal := Val / Small_Value (Typ);
8090 Cint : constant Uint := UR_Trunc (Cintr);
8091 Den : constant Uint := Norm_Den (Cintr);
8095 -- Case of literal is not an exact multiple of the Small
8099 -- For a source program literal for a decimal fixed-point type,
8100 -- this is statically illegal (RM 4.9(36)).
8102 if Is_Decimal_Fixed_Point_Type (Typ)
8103 and then Actual_Typ = Universal_Real
8104 and then Comes_From_Source (N)
8106 Error_Msg_N ("value has extraneous low order digits", N);
8109 -- Generate a warning if literal from source
8111 if Is_Static_Expression (N)
8112 and then Warn_On_Bad_Fixed_Value
8115 ("?static fixed-point value is not a multiple of Small!",
8119 -- Replace literal by a value that is the exact representation
8120 -- of a value of the type, i.e. a multiple of the small value,
8121 -- by truncation, since Machine_Rounds is false for all GNAT
8122 -- fixed-point types (RM 4.9(38)).
8124 Stat := Is_Static_Expression (N);
8126 Make_Real_Literal (Sloc (N),
8127 Realval => Small_Value (Typ) * Cint));
8129 Set_Is_Static_Expression (N, Stat);
8132 -- In all cases, set the corresponding integer field
8134 Set_Corresponding_Integer_Value (N, Cint);
8138 -- Now replace the actual type by the expected type as usual
8141 Eval_Real_Literal (N);
8142 end Resolve_Real_Literal;
8144 -----------------------
8145 -- Resolve_Reference --
8146 -----------------------
8148 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
8149 P : constant Node_Id := Prefix (N);
8152 -- Replace general access with specific type
8154 if Ekind (Etype (N)) = E_Allocator_Type then
8155 Set_Etype (N, Base_Type (Typ));
8158 Resolve (P, Designated_Type (Etype (N)));
8160 -- If we are taking the reference of a volatile entity, then treat it as
8161 -- a potential modification of this entity. This is too conservative,
8162 -- but necessary because remove side effects can cause transformations
8163 -- of normal assignments into reference sequences that otherwise fail to
8164 -- notice the modification.
8166 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
8167 Note_Possible_Modification (P, Sure => False);
8169 end Resolve_Reference;
8171 --------------------------------
8172 -- Resolve_Selected_Component --
8173 --------------------------------
8175 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
8177 Comp1 : Entity_Id := Empty; -- prevent junk warning
8178 P : constant Node_Id := Prefix (N);
8179 S : constant Node_Id := Selector_Name (N);
8180 T : Entity_Id := Etype (P);
8182 I1 : Interp_Index := 0; -- prevent junk warning
8187 function Init_Component return Boolean;
8188 -- Check whether this is the initialization of a component within an
8189 -- init proc (by assignment or call to another init proc). If true,
8190 -- there is no need for a discriminant check.
8192 --------------------
8193 -- Init_Component --
8194 --------------------
8196 function Init_Component return Boolean is
8198 return Inside_Init_Proc
8199 and then Nkind (Prefix (N)) = N_Identifier
8200 and then Chars (Prefix (N)) = Name_uInit
8201 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
8204 -- Start of processing for Resolve_Selected_Component
8207 if Is_Overloaded (P) then
8209 -- Use the context type to select the prefix that has a selector
8210 -- of the correct name and type.
8213 Get_First_Interp (P, I, It);
8215 Search : while Present (It.Typ) loop
8216 if Is_Access_Type (It.Typ) then
8217 T := Designated_Type (It.Typ);
8222 -- Locate selected component. For a private prefix the selector
8223 -- can denote a discriminant.
8225 if Is_Record_Type (T) or else Is_Private_Type (T) then
8227 -- The visible components of a class-wide type are those of
8230 if Is_Class_Wide_Type (T) then
8234 Comp := First_Entity (T);
8235 while Present (Comp) loop
8236 if Chars (Comp) = Chars (S)
8237 and then Covers (Etype (Comp), Typ)
8246 It := Disambiguate (P, I1, I, Any_Type);
8248 if It = No_Interp then
8250 ("ambiguous prefix for selected component", N);
8257 -- There may be an implicit dereference. Retrieve
8258 -- designated record type.
8260 if Is_Access_Type (It1.Typ) then
8261 T := Designated_Type (It1.Typ);
8266 if Scope (Comp1) /= T then
8268 -- Resolution chooses the new interpretation.
8269 -- Find the component with the right name.
8271 Comp1 := First_Entity (T);
8272 while Present (Comp1)
8273 and then Chars (Comp1) /= Chars (S)
8275 Comp1 := Next_Entity (Comp1);
8284 Comp := Next_Entity (Comp);
8288 Get_Next_Interp (I, It);
8291 Resolve (P, It1.Typ);
8293 Set_Entity_With_Style_Check (S, Comp1);
8296 -- Resolve prefix with its type
8301 -- Generate cross-reference. We needed to wait until full overloading
8302 -- resolution was complete to do this, since otherwise we can't tell if
8303 -- we are an lvalue or not.
8305 if May_Be_Lvalue (N) then
8306 Generate_Reference (Entity (S), S, 'm');
8308 Generate_Reference (Entity (S), S, 'r');
8311 -- If prefix is an access type, the node will be transformed into an
8312 -- explicit dereference during expansion. The type of the node is the
8313 -- designated type of that of the prefix.
8315 if Is_Access_Type (Etype (P)) then
8316 T := Designated_Type (Etype (P));
8317 Check_Fully_Declared_Prefix (T, P);
8322 if Has_Discriminants (T)
8323 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
8324 and then Present (Original_Record_Component (Entity (S)))
8325 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
8326 and then Present (Discriminant_Checking_Func
8327 (Original_Record_Component (Entity (S))))
8328 and then not Discriminant_Checks_Suppressed (T)
8329 and then not Init_Component
8331 Set_Do_Discriminant_Check (N);
8334 if Ekind (Entity (S)) = E_Void then
8335 Error_Msg_N ("premature use of component", S);
8338 -- If the prefix is a record conversion, this may be a renamed
8339 -- discriminant whose bounds differ from those of the original
8340 -- one, so we must ensure that a range check is performed.
8342 if Nkind (P) = N_Type_Conversion
8343 and then Ekind (Entity (S)) = E_Discriminant
8344 and then Is_Discrete_Type (Typ)
8346 Set_Etype (N, Base_Type (Typ));
8349 -- Note: No Eval processing is required, because the prefix is of a
8350 -- record type, or protected type, and neither can possibly be static.
8352 -- If the array type is atomic, and is packed, and we are in a left side
8353 -- context, then this is worth a warning, since we have a situation
8354 -- where the access to the component may cause extra read/writes of the
8355 -- atomic array object, which could be considered unexpected.
8357 if Nkind (N) = N_Selected_Component
8358 and then (Is_Atomic (T)
8359 or else (Is_Entity_Name (Prefix (N))
8360 and then Is_Atomic (Entity (Prefix (N)))))
8361 and then Is_Packed (T)
8364 Error_Msg_N ("?assignment to component of packed atomic record",
8366 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
8369 end Resolve_Selected_Component;
8375 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
8376 B_Typ : constant Entity_Id := Base_Type (Typ);
8377 L : constant Node_Id := Left_Opnd (N);
8378 R : constant Node_Id := Right_Opnd (N);
8381 -- We do the resolution using the base type, because intermediate values
8382 -- in expressions always are of the base type, not a subtype of it.
8385 Resolve (R, Standard_Natural);
8387 Check_Unset_Reference (L);
8388 Check_Unset_Reference (R);
8390 Set_Etype (N, B_Typ);
8391 Generate_Operator_Reference (N, B_Typ);
8395 ---------------------------
8396 -- Resolve_Short_Circuit --
8397 ---------------------------
8399 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
8400 B_Typ : constant Entity_Id := Base_Type (Typ);
8401 L : constant Node_Id := Left_Opnd (N);
8402 R : constant Node_Id := Right_Opnd (N);
8408 -- Check for issuing warning for always False assert/check, this happens
8409 -- when assertions are turned off, in which case the pragma Assert/Check
8410 -- was transformed into:
8412 -- if False and then <condition> then ...
8414 -- and we detect this pattern
8416 if Warn_On_Assertion_Failure
8417 and then Is_Entity_Name (R)
8418 and then Entity (R) = Standard_False
8419 and then Nkind (Parent (N)) = N_If_Statement
8420 and then Nkind (N) = N_And_Then
8421 and then Is_Entity_Name (L)
8422 and then Entity (L) = Standard_False
8425 Orig : constant Node_Id := Original_Node (Parent (N));
8428 if Nkind (Orig) = N_Pragma
8429 and then Pragma_Name (Orig) = Name_Assert
8431 -- Don't want to warn if original condition is explicit False
8434 Expr : constant Node_Id :=
8437 (First (Pragma_Argument_Associations (Orig))));
8439 if Is_Entity_Name (Expr)
8440 and then Entity (Expr) = Standard_False
8444 -- Issue warning. We do not want the deletion of the
8445 -- IF/AND-THEN to take this message with it. We achieve
8446 -- this by making sure that the expanded code points to
8447 -- the Sloc of the expression, not the original pragma.
8450 ("?assertion would fail at run time!",
8452 (First (Pragma_Argument_Associations (Orig))));
8456 -- Similar processing for Check pragma
8458 elsif Nkind (Orig) = N_Pragma
8459 and then Pragma_Name (Orig) = Name_Check
8461 -- Don't want to warn if original condition is explicit False
8464 Expr : constant Node_Id :=
8468 (Pragma_Argument_Associations (Orig)))));
8470 if Is_Entity_Name (Expr)
8471 and then Entity (Expr) = Standard_False
8476 ("?check would fail at run time!",
8478 (Last (Pragma_Argument_Associations (Orig))));
8485 -- Continue with processing of short circuit
8487 Check_Unset_Reference (L);
8488 Check_Unset_Reference (R);
8490 Set_Etype (N, B_Typ);
8491 Eval_Short_Circuit (N);
8492 end Resolve_Short_Circuit;
8498 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
8499 Name : constant Node_Id := Prefix (N);
8500 Drange : constant Node_Id := Discrete_Range (N);
8501 Array_Type : Entity_Id := Empty;
8505 if Is_Overloaded (Name) then
8507 -- Use the context type to select the prefix that yields the correct
8512 I1 : Interp_Index := 0;
8514 P : constant Node_Id := Prefix (N);
8515 Found : Boolean := False;
8518 Get_First_Interp (P, I, It);
8519 while Present (It.Typ) loop
8520 if (Is_Array_Type (It.Typ)
8521 and then Covers (Typ, It.Typ))
8522 or else (Is_Access_Type (It.Typ)
8523 and then Is_Array_Type (Designated_Type (It.Typ))
8524 and then Covers (Typ, Designated_Type (It.Typ)))
8527 It := Disambiguate (P, I1, I, Any_Type);
8529 if It = No_Interp then
8530 Error_Msg_N ("ambiguous prefix for slicing", N);
8535 Array_Type := It.Typ;
8540 Array_Type := It.Typ;
8545 Get_Next_Interp (I, It);
8550 Array_Type := Etype (Name);
8553 Resolve (Name, Array_Type);
8555 if Is_Access_Type (Array_Type) then
8556 Apply_Access_Check (N);
8557 Array_Type := Designated_Type (Array_Type);
8559 -- If the prefix is an access to an unconstrained array, we must use
8560 -- the actual subtype of the object to perform the index checks. The
8561 -- object denoted by the prefix is implicit in the node, so we build
8562 -- an explicit representation for it in order to compute the actual
8565 if not Is_Constrained (Array_Type) then
8566 Remove_Side_Effects (Prefix (N));
8569 Obj : constant Node_Id :=
8570 Make_Explicit_Dereference (Sloc (N),
8571 Prefix => New_Copy_Tree (Prefix (N)));
8573 Set_Etype (Obj, Array_Type);
8574 Set_Parent (Obj, Parent (N));
8575 Array_Type := Get_Actual_Subtype (Obj);
8579 elsif Is_Entity_Name (Name)
8580 or else Nkind (Name) = N_Explicit_Dereference
8581 or else (Nkind (Name) = N_Function_Call
8582 and then not Is_Constrained (Etype (Name)))
8584 Array_Type := Get_Actual_Subtype (Name);
8586 -- If the name is a selected component that depends on discriminants,
8587 -- build an actual subtype for it. This can happen only when the name
8588 -- itself is overloaded; otherwise the actual subtype is created when
8589 -- the selected component is analyzed.
8591 elsif Nkind (Name) = N_Selected_Component
8592 and then Full_Analysis
8593 and then Depends_On_Discriminant (First_Index (Array_Type))
8596 Act_Decl : constant Node_Id :=
8597 Build_Actual_Subtype_Of_Component (Array_Type, Name);
8599 Insert_Action (N, Act_Decl);
8600 Array_Type := Defining_Identifier (Act_Decl);
8603 -- Maybe this should just be "else", instead of checking for the
8604 -- specific case of slice??? This is needed for the case where the
8605 -- prefix is an Image attribute, which gets expanded to a slice, and so
8606 -- has a constrained subtype which we want to use for the slice range
8607 -- check applied below (the range check won't get done if the
8608 -- unconstrained subtype of the 'Image is used).
8610 elsif Nkind (Name) = N_Slice then
8611 Array_Type := Etype (Name);
8614 -- If name was overloaded, set slice type correctly now
8616 Set_Etype (N, Array_Type);
8618 -- If the range is specified by a subtype mark, no resolution is
8619 -- necessary. Else resolve the bounds, and apply needed checks.
8621 if not Is_Entity_Name (Drange) then
8622 Index := First_Index (Array_Type);
8623 Resolve (Drange, Base_Type (Etype (Index)));
8625 if Nkind (Drange) = N_Range then
8627 -- Ensure that side effects in the bounds are properly handled
8629 Force_Evaluation (Low_Bound (Drange));
8630 Force_Evaluation (High_Bound (Drange));
8632 -- Do not apply the range check to nodes associated with the
8633 -- frontend expansion of the dispatch table. We first check
8634 -- if Ada.Tags is already loaded to avoid the addition of an
8635 -- undesired dependence on such run-time unit.
8637 if not Tagged_Type_Expansion
8639 (RTU_Loaded (Ada_Tags)
8640 and then Nkind (Prefix (N)) = N_Selected_Component
8641 and then Present (Entity (Selector_Name (Prefix (N))))
8642 and then Entity (Selector_Name (Prefix (N))) =
8643 RTE_Record_Component (RE_Prims_Ptr))
8645 Apply_Range_Check (Drange, Etype (Index));
8650 Set_Slice_Subtype (N);
8652 -- Check bad use of type with predicates
8654 if Has_Predicates (Etype (Drange)) then
8655 Bad_Predicated_Subtype_Use
8656 ("subtype& has predicate, not allowed in slice",
8657 Drange, Etype (Drange));
8659 -- Otherwise here is where we check suspicious indexes
8661 elsif Nkind (Drange) = N_Range then
8662 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8663 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8669 ----------------------------
8670 -- Resolve_String_Literal --
8671 ----------------------------
8673 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8674 C_Typ : constant Entity_Id := Component_Type (Typ);
8675 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8676 Loc : constant Source_Ptr := Sloc (N);
8677 Str : constant String_Id := Strval (N);
8678 Strlen : constant Nat := String_Length (Str);
8679 Subtype_Id : Entity_Id;
8680 Need_Check : Boolean;
8683 -- For a string appearing in a concatenation, defer creation of the
8684 -- string_literal_subtype until the end of the resolution of the
8685 -- concatenation, because the literal may be constant-folded away. This
8686 -- is a useful optimization for long concatenation expressions.
8688 -- If the string is an aggregate built for a single character (which
8689 -- happens in a non-static context) or a is null string to which special
8690 -- checks may apply, we build the subtype. Wide strings must also get a
8691 -- string subtype if they come from a one character aggregate. Strings
8692 -- generated by attributes might be static, but it is often hard to
8693 -- determine whether the enclosing context is static, so we generate
8694 -- subtypes for them as well, thus losing some rarer optimizations ???
8695 -- Same for strings that come from a static conversion.
8698 (Strlen = 0 and then Typ /= Standard_String)
8699 or else Nkind (Parent (N)) /= N_Op_Concat
8700 or else (N /= Left_Opnd (Parent (N))
8701 and then N /= Right_Opnd (Parent (N)))
8702 or else ((Typ = Standard_Wide_String
8703 or else Typ = Standard_Wide_Wide_String)
8704 and then Nkind (Original_Node (N)) /= N_String_Literal);
8706 -- If the resolving type is itself a string literal subtype, we can just
8707 -- reuse it, since there is no point in creating another.
8709 if Ekind (Typ) = E_String_Literal_Subtype then
8712 elsif Nkind (Parent (N)) = N_Op_Concat
8713 and then not Need_Check
8714 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8715 N_Attribute_Reference,
8716 N_Qualified_Expression,
8721 -- Otherwise we must create a string literal subtype. Note that the
8722 -- whole idea of string literal subtypes is simply to avoid the need
8723 -- for building a full fledged array subtype for each literal.
8726 Set_String_Literal_Subtype (N, Typ);
8727 Subtype_Id := Etype (N);
8730 if Nkind (Parent (N)) /= N_Op_Concat
8733 Set_Etype (N, Subtype_Id);
8734 Eval_String_Literal (N);
8737 if Is_Limited_Composite (Typ)
8738 or else Is_Private_Composite (Typ)
8740 Error_Msg_N ("string literal not available for private array", N);
8741 Set_Etype (N, Any_Type);
8745 -- The validity of a null string has been checked in the call to
8746 -- Eval_String_Literal.
8751 -- Always accept string literal with component type Any_Character, which
8752 -- occurs in error situations and in comparisons of literals, both of
8753 -- which should accept all literals.
8755 elsif R_Typ = Any_Character then
8758 -- If the type is bit-packed, then we always transform the string
8759 -- literal into a full fledged aggregate.
8761 elsif Is_Bit_Packed_Array (Typ) then
8764 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8767 -- For Standard.Wide_Wide_String, or any other type whose component
8768 -- type is Standard.Wide_Wide_Character, we know that all the
8769 -- characters in the string must be acceptable, since the parser
8770 -- accepted the characters as valid character literals.
8772 if R_Typ = Standard_Wide_Wide_Character then
8775 -- For the case of Standard.String, or any other type whose component
8776 -- type is Standard.Character, we must make sure that there are no
8777 -- wide characters in the string, i.e. that it is entirely composed
8778 -- of characters in range of type Character.
8780 -- If the string literal is the result of a static concatenation, the
8781 -- test has already been performed on the components, and need not be
8784 elsif R_Typ = Standard_Character
8785 and then Nkind (Original_Node (N)) /= N_Op_Concat
8787 for J in 1 .. Strlen loop
8788 if not In_Character_Range (Get_String_Char (Str, J)) then
8790 -- If we are out of range, post error. This is one of the
8791 -- very few places that we place the flag in the middle of
8792 -- a token, right under the offending wide character. Not
8793 -- quite clear if this is right wrt wide character encoding
8794 -- sequences, but it's only an error message!
8797 ("literal out of range of type Standard.Character",
8798 Source_Ptr (Int (Loc) + J));
8803 -- For the case of Standard.Wide_String, or any other type whose
8804 -- component type is Standard.Wide_Character, we must make sure that
8805 -- there are no wide characters in the string, i.e. that it is
8806 -- entirely composed of characters in range of type Wide_Character.
8808 -- If the string literal is the result of a static concatenation,
8809 -- the test has already been performed on the components, and need
8812 elsif R_Typ = Standard_Wide_Character
8813 and then Nkind (Original_Node (N)) /= N_Op_Concat
8815 for J in 1 .. Strlen loop
8816 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8818 -- If we are out of range, post error. This is one of the
8819 -- very few places that we place the flag in the middle of
8820 -- a token, right under the offending wide character.
8822 -- This is not quite right, because characters in general
8823 -- will take more than one character position ???
8826 ("literal out of range of type Standard.Wide_Character",
8827 Source_Ptr (Int (Loc) + J));
8832 -- If the root type is not a standard character, then we will convert
8833 -- the string into an aggregate and will let the aggregate code do
8834 -- the checking. Standard Wide_Wide_Character is also OK here.
8840 -- See if the component type of the array corresponding to the string
8841 -- has compile time known bounds. If yes we can directly check
8842 -- whether the evaluation of the string will raise constraint error.
8843 -- Otherwise we need to transform the string literal into the
8844 -- corresponding character aggregate and let the aggregate code do
8847 if Is_Standard_Character_Type (R_Typ) then
8849 -- Check for the case of full range, where we are definitely OK
8851 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8855 -- Here the range is not the complete base type range, so check
8858 Comp_Typ_Lo : constant Node_Id :=
8859 Type_Low_Bound (Component_Type (Typ));
8860 Comp_Typ_Hi : constant Node_Id :=
8861 Type_High_Bound (Component_Type (Typ));
8866 if Compile_Time_Known_Value (Comp_Typ_Lo)
8867 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8869 for J in 1 .. Strlen loop
8870 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8872 if Char_Val < Expr_Value (Comp_Typ_Lo)
8873 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8875 Apply_Compile_Time_Constraint_Error
8876 (N, "character out of range?", CE_Range_Check_Failed,
8877 Loc => Source_Ptr (Int (Loc) + J));
8887 -- If we got here we meed to transform the string literal into the
8888 -- equivalent qualified positional array aggregate. This is rather
8889 -- heavy artillery for this situation, but it is hard work to avoid.
8892 Lits : constant List_Id := New_List;
8893 P : Source_Ptr := Loc + 1;
8897 -- Build the character literals, we give them source locations that
8898 -- correspond to the string positions, which is a bit tricky given
8899 -- the possible presence of wide character escape sequences.
8901 for J in 1 .. Strlen loop
8902 C := Get_String_Char (Str, J);
8903 Set_Character_Literal_Name (C);
8906 Make_Character_Literal (P,
8908 Char_Literal_Value => UI_From_CC (C)));
8910 if In_Character_Range (C) then
8913 -- Should we have a call to Skip_Wide here ???
8922 Make_Qualified_Expression (Loc,
8923 Subtype_Mark => New_Reference_To (Typ, Loc),
8925 Make_Aggregate (Loc, Expressions => Lits)));
8927 Analyze_And_Resolve (N, Typ);
8929 end Resolve_String_Literal;
8931 -----------------------------
8932 -- Resolve_Subprogram_Info --
8933 -----------------------------
8935 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8938 end Resolve_Subprogram_Info;
8940 -----------------------------
8941 -- Resolve_Type_Conversion --
8942 -----------------------------
8944 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8945 Conv_OK : constant Boolean := Conversion_OK (N);
8946 Operand : constant Node_Id := Expression (N);
8947 Operand_Typ : constant Entity_Id := Etype (Operand);
8948 Target_Typ : constant Entity_Id := Etype (N);
8953 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
8954 -- Set to False to suppress cases where we want to suppress the test
8955 -- for redundancy to avoid possible false positives on this warning.
8959 and then not Valid_Conversion (N, Target_Typ, Operand)
8964 -- If the Operand Etype is Universal_Fixed, then the conversion is
8965 -- never redundant. We need this check because by the time we have
8966 -- finished the rather complex transformation, the conversion looks
8967 -- redundant when it is not.
8969 if Operand_Typ = Universal_Fixed then
8970 Test_Redundant := False;
8972 -- If the operand is marked as Any_Fixed, then special processing is
8973 -- required. This is also a case where we suppress the test for a
8974 -- redundant conversion, since most certainly it is not redundant.
8976 elsif Operand_Typ = Any_Fixed then
8977 Test_Redundant := False;
8979 -- Mixed-mode operation involving a literal. Context must be a fixed
8980 -- type which is applied to the literal subsequently.
8982 if Is_Fixed_Point_Type (Typ) then
8983 Set_Etype (Operand, Universal_Real);
8985 elsif Is_Numeric_Type (Typ)
8986 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8987 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8989 Etype (Left_Opnd (Operand)) = Universal_Real)
8991 -- Return if expression is ambiguous
8993 if Unique_Fixed_Point_Type (N) = Any_Type then
8996 -- If nothing else, the available fixed type is Duration
8999 Set_Etype (Operand, Standard_Duration);
9002 -- Resolve the real operand with largest available precision
9004 if Etype (Right_Opnd (Operand)) = Universal_Real then
9005 Rop := New_Copy_Tree (Right_Opnd (Operand));
9007 Rop := New_Copy_Tree (Left_Opnd (Operand));
9010 Resolve (Rop, Universal_Real);
9012 -- If the operand is a literal (it could be a non-static and
9013 -- illegal exponentiation) check whether the use of Duration
9014 -- is potentially inaccurate.
9016 if Nkind (Rop) = N_Real_Literal
9017 and then Realval (Rop) /= Ureal_0
9018 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9021 ("?universal real operand can only " &
9022 "be interpreted as Duration!",
9025 ("\?precision will be lost in the conversion!", Rop);
9028 elsif Is_Numeric_Type (Typ)
9029 and then Nkind (Operand) in N_Op
9030 and then Unique_Fixed_Point_Type (N) /= Any_Type
9032 Set_Etype (Operand, Standard_Duration);
9035 Error_Msg_N ("invalid context for mixed mode operation", N);
9036 Set_Etype (Operand, Any_Type);
9043 -- In SPARK, a type conversion between array types should be restricted
9044 -- to types which have matching static bounds.
9046 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9047 -- operation if not needed.
9049 if Restriction_Check_Required (SPARK)
9050 and then Is_Array_Type (Target_Typ)
9051 and then Is_Array_Type (Operand_Typ)
9052 and then Operand_Typ /= Any_Composite -- or else Operand in error
9053 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
9055 Check_SPARK_Restriction
9056 ("array types should have matching static bounds", N);
9059 -- In formal mode, the operand of an ancestor type conversion must be an
9060 -- object (not an expression).
9062 if Is_Tagged_Type (Target_Typ)
9063 and then not Is_Class_Wide_Type (Target_Typ)
9064 and then Is_Tagged_Type (Operand_Typ)
9065 and then not Is_Class_Wide_Type (Operand_Typ)
9066 and then Is_Ancestor (Target_Typ, Operand_Typ)
9067 and then not Is_SPARK_Object_Reference (Operand)
9069 Check_SPARK_Restriction ("object required", Operand);
9072 -- Note: we do the Eval_Type_Conversion call before applying the
9073 -- required checks for a subtype conversion. This is important, since
9074 -- both are prepared under certain circumstances to change the type
9075 -- conversion to a constraint error node, but in the case of
9076 -- Eval_Type_Conversion this may reflect an illegality in the static
9077 -- case, and we would miss the illegality (getting only a warning
9078 -- message), if we applied the type conversion checks first.
9080 Eval_Type_Conversion (N);
9082 -- Even when evaluation is not possible, we may be able to simplify the
9083 -- conversion or its expression. This needs to be done before applying
9084 -- checks, since otherwise the checks may use the original expression
9085 -- and defeat the simplifications. This is specifically the case for
9086 -- elimination of the floating-point Truncation attribute in
9087 -- float-to-int conversions.
9089 Simplify_Type_Conversion (N);
9091 -- If after evaluation we still have a type conversion, then we may need
9092 -- to apply checks required for a subtype conversion.
9094 -- Skip these type conversion checks if universal fixed operands
9095 -- operands involved, since range checks are handled separately for
9096 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9098 if Nkind (N) = N_Type_Conversion
9099 and then not Is_Generic_Type (Root_Type (Target_Typ))
9100 and then Target_Typ /= Universal_Fixed
9101 and then Operand_Typ /= Universal_Fixed
9103 Apply_Type_Conversion_Checks (N);
9106 -- Issue warning for conversion of simple object to its own type. We
9107 -- have to test the original nodes, since they may have been rewritten
9108 -- by various optimizations.
9110 Orig_N := Original_Node (N);
9112 -- Here we test for a redundant conversion if the warning mode is
9113 -- active (and was not locally reset), and we have a type conversion
9114 -- from source not appearing in a generic instance.
9117 and then Nkind (Orig_N) = N_Type_Conversion
9118 and then Comes_From_Source (Orig_N)
9119 and then not In_Instance
9121 Orig_N := Original_Node (Expression (Orig_N));
9122 Orig_T := Target_Typ;
9124 -- If the node is part of a larger expression, the Target_Type
9125 -- may not be the original type of the node if the context is a
9126 -- condition. Recover original type to see if conversion is needed.
9128 if Is_Boolean_Type (Orig_T)
9129 and then Nkind (Parent (N)) in N_Op
9131 Orig_T := Etype (Parent (N));
9134 -- If we have an entity name, then give the warning if the entity
9135 -- is the right type, or if it is a loop parameter covered by the
9136 -- original type (that's needed because loop parameters have an
9137 -- odd subtype coming from the bounds).
9139 if (Is_Entity_Name (Orig_N)
9141 (Etype (Entity (Orig_N)) = Orig_T
9143 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
9144 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
9146 -- If not an entity, then type of expression must match
9148 or else Etype (Orig_N) = Orig_T
9150 -- One more check, do not give warning if the analyzed conversion
9151 -- has an expression with non-static bounds, and the bounds of the
9152 -- target are static. This avoids junk warnings in cases where the
9153 -- conversion is necessary to establish staticness, for example in
9154 -- a case statement.
9156 if not Is_OK_Static_Subtype (Operand_Typ)
9157 and then Is_OK_Static_Subtype (Target_Typ)
9161 -- Finally, if this type conversion occurs in a context requiring
9162 -- a prefix, and the expression is a qualified expression then the
9163 -- type conversion is not redundant, since a qualified expression
9164 -- is not a prefix, whereas a type conversion is. For example, "X
9165 -- := T'(Funx(...)).Y;" is illegal because a selected component
9166 -- requires a prefix, but a type conversion makes it legal: "X :=
9167 -- T(T'(Funx(...))).Y;"
9169 -- In Ada 2012, a qualified expression is a name, so this idiom is
9170 -- no longer needed, but we still suppress the warning because it
9171 -- seems unfriendly for warnings to pop up when you switch to the
9172 -- newer language version.
9174 elsif Nkind (Orig_N) = N_Qualified_Expression
9175 and then Nkind_In (Parent (N), N_Attribute_Reference,
9176 N_Indexed_Component,
9177 N_Selected_Component,
9179 N_Explicit_Dereference)
9183 -- Here we give the redundant conversion warning. If it is an
9184 -- entity, give the name of the entity in the message. If not,
9185 -- just mention the expression.
9188 if Is_Entity_Name (Orig_N) then
9189 Error_Msg_Node_2 := Orig_T;
9190 Error_Msg_NE -- CODEFIX
9191 ("?redundant conversion, & is of type &!",
9192 N, Entity (Orig_N));
9195 ("?redundant conversion, expression is of type&!",
9202 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
9203 -- No need to perform any interface conversion if the type of the
9204 -- expression coincides with the target type.
9206 if Ada_Version >= Ada_2005
9207 and then Expander_Active
9208 and then Operand_Typ /= Target_Typ
9211 Opnd : Entity_Id := Operand_Typ;
9212 Target : Entity_Id := Target_Typ;
9215 if Is_Access_Type (Opnd) then
9216 Opnd := Designated_Type (Opnd);
9219 if Is_Access_Type (Target_Typ) then
9220 Target := Designated_Type (Target);
9223 if Opnd = Target then
9226 -- Conversion from interface type
9228 elsif Is_Interface (Opnd) then
9230 -- Ada 2005 (AI-217): Handle entities from limited views
9232 if From_With_Type (Opnd) then
9233 Error_Msg_Qual_Level := 99;
9234 Error_Msg_NE -- CODEFIX
9235 ("missing WITH clause on package &", N,
9236 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
9238 ("type conversions require visibility of the full view",
9241 elsif From_With_Type (Target)
9243 (Is_Access_Type (Target_Typ)
9244 and then Present (Non_Limited_View (Etype (Target))))
9246 Error_Msg_Qual_Level := 99;
9247 Error_Msg_NE -- CODEFIX
9248 ("missing WITH clause on package &", N,
9249 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
9251 ("type conversions require visibility of the full view",
9255 Expand_Interface_Conversion (N, Is_Static => False);
9258 -- Conversion to interface type
9260 elsif Is_Interface (Target) then
9264 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
9265 Opnd := Etype (Opnd);
9268 if not Interface_Present_In_Ancestor
9272 if Is_Class_Wide_Type (Opnd) then
9274 -- The static analysis is not enough to know if the
9275 -- interface is implemented or not. Hence we must pass
9276 -- the work to the expander to generate code to evaluate
9277 -- the conversion at run time.
9279 Expand_Interface_Conversion (N, Is_Static => False);
9282 Error_Msg_Name_1 := Chars (Etype (Target));
9283 Error_Msg_Name_2 := Chars (Opnd);
9285 ("wrong interface conversion (% is not a progenitor " &
9290 Expand_Interface_Conversion (N);
9295 end Resolve_Type_Conversion;
9297 ----------------------
9298 -- Resolve_Unary_Op --
9299 ----------------------
9301 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
9302 B_Typ : constant Entity_Id := Base_Type (Typ);
9303 R : constant Node_Id := Right_Opnd (N);
9309 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
9310 Error_Msg_Name_1 := Chars (Typ);
9311 Check_SPARK_Restriction
9312 ("unary operator not defined for modular type%", N);
9315 -- Deal with intrinsic unary operators
9317 if Comes_From_Source (N)
9318 and then Ekind (Entity (N)) = E_Function
9319 and then Is_Imported (Entity (N))
9320 and then Is_Intrinsic_Subprogram (Entity (N))
9322 Resolve_Intrinsic_Unary_Operator (N, Typ);
9326 -- Deal with universal cases
9328 if Etype (R) = Universal_Integer
9330 Etype (R) = Universal_Real
9332 Check_For_Visible_Operator (N, B_Typ);
9335 Set_Etype (N, B_Typ);
9338 -- Generate warning for expressions like abs (x mod 2)
9340 if Warn_On_Redundant_Constructs
9341 and then Nkind (N) = N_Op_Abs
9343 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
9345 if OK and then Hi >= Lo and then Lo >= 0 then
9346 Error_Msg_N -- CODEFIX
9347 ("?abs applied to known non-negative value has no effect", N);
9351 -- Deal with reference generation
9353 Check_Unset_Reference (R);
9354 Generate_Operator_Reference (N, B_Typ);
9357 -- Set overflow checking bit. Much cleverer code needed here eventually
9358 -- and perhaps the Resolve routines should be separated for the various
9359 -- arithmetic operations, since they will need different processing ???
9361 if Nkind (N) in N_Op then
9362 if not Overflow_Checks_Suppressed (Etype (N)) then
9363 Enable_Overflow_Check (N);
9367 -- Generate warning for expressions like -5 mod 3 for integers. No need
9368 -- to worry in the floating-point case, since parens do not affect the
9369 -- result so there is no point in giving in a warning.
9372 Norig : constant Node_Id := Original_Node (N);
9381 if Warn_On_Questionable_Missing_Parens
9382 and then Comes_From_Source (Norig)
9383 and then Is_Integer_Type (Typ)
9384 and then Nkind (Norig) = N_Op_Minus
9386 Rorig := Original_Node (Right_Opnd (Norig));
9388 -- We are looking for cases where the right operand is not
9389 -- parenthesized, and is a binary operator, multiply, divide, or
9390 -- mod. These are the cases where the grouping can affect results.
9392 if Paren_Count (Rorig) = 0
9393 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
9395 -- For mod, we always give the warning, since the value is
9396 -- affected by the parenthesization (e.g. (-5) mod 315 /=
9397 -- -(5 mod 315)). But for the other cases, the only concern is
9398 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
9399 -- overflows, but (-2) * 64 does not). So we try to give the
9400 -- message only when overflow is possible.
9402 if Nkind (Rorig) /= N_Op_Mod
9403 and then Compile_Time_Known_Value (R)
9405 Val := Expr_Value (R);
9407 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
9408 HB := Expr_Value (Type_High_Bound (Typ));
9410 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
9413 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
9414 LB := Expr_Value (Type_Low_Bound (Typ));
9416 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
9419 -- Note that the test below is deliberately excluding the
9420 -- largest negative number, since that is a potentially
9421 -- troublesome case (e.g. -2 * x, where the result is the
9422 -- largest negative integer has an overflow with 2 * x).
9424 if Val > LB and then Val <= HB then
9429 -- For the multiplication case, the only case we have to worry
9430 -- about is when (-a)*b is exactly the largest negative number
9431 -- so that -(a*b) can cause overflow. This can only happen if
9432 -- a is a power of 2, and more generally if any operand is a
9433 -- constant that is not a power of 2, then the parentheses
9434 -- cannot affect whether overflow occurs. We only bother to
9435 -- test the left most operand
9437 -- Loop looking at left operands for one that has known value
9440 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
9441 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
9442 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
9444 -- Operand value of 0 or 1 skips warning
9449 -- Otherwise check power of 2, if power of 2, warn, if
9450 -- anything else, skip warning.
9453 while Lval /= 2 loop
9454 if Lval mod 2 = 1 then
9465 -- Keep looking at left operands
9467 Opnd := Left_Opnd (Opnd);
9470 -- For rem or "/" we can only have a problematic situation
9471 -- if the divisor has a value of minus one or one. Otherwise
9472 -- overflow is impossible (divisor > 1) or we have a case of
9473 -- division by zero in any case.
9475 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
9476 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
9477 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
9482 -- If we fall through warning should be issued
9485 ("?unary minus expression should be parenthesized here!", N);
9489 end Resolve_Unary_Op;
9491 ----------------------------------
9492 -- Resolve_Unchecked_Expression --
9493 ----------------------------------
9495 procedure Resolve_Unchecked_Expression
9500 Resolve (Expression (N), Typ, Suppress => All_Checks);
9502 end Resolve_Unchecked_Expression;
9504 ---------------------------------------
9505 -- Resolve_Unchecked_Type_Conversion --
9506 ---------------------------------------
9508 procedure Resolve_Unchecked_Type_Conversion
9512 pragma Warnings (Off, Typ);
9514 Operand : constant Node_Id := Expression (N);
9515 Opnd_Type : constant Entity_Id := Etype (Operand);
9518 -- Resolve operand using its own type
9520 Resolve (Operand, Opnd_Type);
9521 Eval_Unchecked_Conversion (N);
9522 end Resolve_Unchecked_Type_Conversion;
9524 ------------------------------
9525 -- Rewrite_Operator_As_Call --
9526 ------------------------------
9528 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
9529 Loc : constant Source_Ptr := Sloc (N);
9530 Actuals : constant List_Id := New_List;
9534 if Nkind (N) in N_Binary_Op then
9535 Append (Left_Opnd (N), Actuals);
9538 Append (Right_Opnd (N), Actuals);
9541 Make_Function_Call (Sloc => Loc,
9542 Name => New_Occurrence_Of (Nam, Loc),
9543 Parameter_Associations => Actuals);
9545 Preserve_Comes_From_Source (New_N, N);
9546 Preserve_Comes_From_Source (Name (New_N), N);
9548 Set_Etype (N, Etype (Nam));
9549 end Rewrite_Operator_As_Call;
9551 ------------------------------
9552 -- Rewrite_Renamed_Operator --
9553 ------------------------------
9555 procedure Rewrite_Renamed_Operator
9560 Nam : constant Name_Id := Chars (Op);
9561 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
9565 -- Rewrite the operator node using the real operator, not its renaming.
9566 -- Exclude user-defined intrinsic operations of the same name, which are
9567 -- treated separately and rewritten as calls.
9569 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
9570 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
9571 Set_Chars (Op_Node, Nam);
9572 Set_Etype (Op_Node, Etype (N));
9573 Set_Entity (Op_Node, Op);
9574 Set_Right_Opnd (Op_Node, Right_Opnd (N));
9576 -- Indicate that both the original entity and its renaming are
9577 -- referenced at this point.
9579 Generate_Reference (Entity (N), N);
9580 Generate_Reference (Op, N);
9583 Set_Left_Opnd (Op_Node, Left_Opnd (N));
9586 Rewrite (N, Op_Node);
9588 -- If the context type is private, add the appropriate conversions so
9589 -- that the operator is applied to the full view. This is done in the
9590 -- routines that resolve intrinsic operators.
9592 if Is_Intrinsic_Subprogram (Op)
9593 and then Is_Private_Type (Typ)
9596 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
9597 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
9598 Resolve_Intrinsic_Operator (N, Typ);
9600 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
9601 Resolve_Intrinsic_Unary_Operator (N, Typ);
9608 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
9610 -- Operator renames a user-defined operator of the same name. Use the
9611 -- original operator in the node, which is the one Gigi knows about.
9614 Set_Is_Overloaded (N, False);
9616 end Rewrite_Renamed_Operator;
9618 -----------------------
9619 -- Set_Slice_Subtype --
9620 -----------------------
9622 -- Build an implicit subtype declaration to represent the type delivered by
9623 -- the slice. This is an abbreviated version of an array subtype. We define
9624 -- an index subtype for the slice, using either the subtype name or the
9625 -- discrete range of the slice. To be consistent with index usage elsewhere
9626 -- we create a list header to hold the single index. This list is not
9627 -- otherwise attached to the syntax tree.
9629 procedure Set_Slice_Subtype (N : Node_Id) is
9630 Loc : constant Source_Ptr := Sloc (N);
9631 Index_List : constant List_Id := New_List;
9633 Index_Subtype : Entity_Id;
9634 Index_Type : Entity_Id;
9635 Slice_Subtype : Entity_Id;
9636 Drange : constant Node_Id := Discrete_Range (N);
9639 if Is_Entity_Name (Drange) then
9640 Index_Subtype := Entity (Drange);
9643 -- We force the evaluation of a range. This is definitely needed in
9644 -- the renamed case, and seems safer to do unconditionally. Note in
9645 -- any case that since we will create and insert an Itype referring
9646 -- to this range, we must make sure any side effect removal actions
9647 -- are inserted before the Itype definition.
9649 if Nkind (Drange) = N_Range then
9650 Force_Evaluation (Low_Bound (Drange));
9651 Force_Evaluation (High_Bound (Drange));
9654 Index_Type := Base_Type (Etype (Drange));
9656 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9658 -- Take a new copy of Drange (where bounds have been rewritten to
9659 -- reference side-effect-free names). Using a separate tree ensures
9660 -- that further expansion (e.g. while rewriting a slice assignment
9661 -- into a FOR loop) does not attempt to remove side effects on the
9662 -- bounds again (which would cause the bounds in the index subtype
9663 -- definition to refer to temporaries before they are defined) (the
9664 -- reason is that some names are considered side effect free here
9665 -- for the subtype, but not in the context of a loop iteration
9668 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
9669 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
9670 Set_Etype (Index_Subtype, Index_Type);
9671 Set_Size_Info (Index_Subtype, Index_Type);
9672 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9675 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
9677 Index := New_Occurrence_Of (Index_Subtype, Loc);
9678 Set_Etype (Index, Index_Subtype);
9679 Append (Index, Index_List);
9681 Set_First_Index (Slice_Subtype, Index);
9682 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
9683 Set_Is_Constrained (Slice_Subtype, True);
9685 Check_Compile_Time_Size (Slice_Subtype);
9687 -- The Etype of the existing Slice node is reset to this slice subtype.
9688 -- Its bounds are obtained from its first index.
9690 Set_Etype (N, Slice_Subtype);
9692 -- For packed slice subtypes, freeze immediately (except in the case of
9693 -- being in a "spec expression" where we never freeze when we first see
9696 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
9697 Freeze_Itype (Slice_Subtype, N);
9699 -- For all other cases insert an itype reference in the slice's actions
9700 -- so that the itype is frozen at the proper place in the tree (i.e. at
9701 -- the point where actions for the slice are analyzed). Note that this
9702 -- is different from freezing the itype immediately, which might be
9703 -- premature (e.g. if the slice is within a transient scope). This needs
9704 -- to be done only if expansion is enabled.
9706 elsif Expander_Active then
9707 Ensure_Defined (Typ => Slice_Subtype, N => N);
9709 end Set_Slice_Subtype;
9711 --------------------------------
9712 -- Set_String_Literal_Subtype --
9713 --------------------------------
9715 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
9716 Loc : constant Source_Ptr := Sloc (N);
9717 Low_Bound : constant Node_Id :=
9718 Type_Low_Bound (Etype (First_Index (Typ)));
9719 Subtype_Id : Entity_Id;
9722 if Nkind (N) /= N_String_Literal then
9726 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
9727 Set_String_Literal_Length (Subtype_Id, UI_From_Int
9728 (String_Length (Strval (N))));
9729 Set_Etype (Subtype_Id, Base_Type (Typ));
9730 Set_Is_Constrained (Subtype_Id);
9731 Set_Etype (N, Subtype_Id);
9733 if Is_OK_Static_Expression (Low_Bound) then
9735 -- The low bound is set from the low bound of the corresponding index
9736 -- type. Note that we do not store the high bound in the string literal
9737 -- subtype, but it can be deduced if necessary from the length and the
9740 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
9743 -- If the lower bound is not static we create a range for the string
9744 -- literal, using the index type and the known length of the literal.
9745 -- The index type is not necessarily Positive, so the upper bound is
9746 -- computed as T'Val (T'Pos (Low_Bound) + L - 1)
9749 Index_List : constant List_Id := New_List;
9750 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9752 High_Bound : constant Node_Id :=
9753 Make_Attribute_Reference (Loc,
9754 Attribute_Name => Name_Val,
9756 New_Occurrence_Of (Index_Type, Loc),
9757 Expressions => New_List (
9760 Make_Attribute_Reference (Loc,
9761 Attribute_Name => Name_Pos,
9763 New_Occurrence_Of (Index_Type, Loc),
9765 New_List (New_Copy_Tree (Low_Bound))),
9767 Make_Integer_Literal (Loc,
9768 String_Length (Strval (N)) - 1))));
9770 Array_Subtype : Entity_Id;
9771 Index_Subtype : Entity_Id;
9776 if Is_Integer_Type (Index_Type) then
9777 Set_String_Literal_Low_Bound
9778 (Subtype_Id, Make_Integer_Literal (Loc, 1));
9781 -- If the index type is an enumeration type, build bounds
9782 -- expression with attributes.
9784 Set_String_Literal_Low_Bound
9786 Make_Attribute_Reference (Loc,
9787 Attribute_Name => Name_First,
9789 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
9790 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
9793 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
9795 -- Build bona fide subtype for the string, and wrap it in an
9796 -- unchecked conversion, because the backend expects the
9797 -- String_Literal_Subtype to have a static lower bound.
9800 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9801 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
9802 Set_Scalar_Range (Index_Subtype, Drange);
9803 Set_Parent (Drange, N);
9804 Analyze_And_Resolve (Drange, Index_Type);
9806 -- In the context, the Index_Type may already have a constraint,
9807 -- so use common base type on string subtype. The base type may
9808 -- be used when generating attributes of the string, for example
9809 -- in the context of a slice assignment.
9811 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9812 Set_Size_Info (Index_Subtype, Index_Type);
9813 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9815 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9817 Index := New_Occurrence_Of (Index_Subtype, Loc);
9818 Set_Etype (Index, Index_Subtype);
9819 Append (Index, Index_List);
9821 Set_First_Index (Array_Subtype, Index);
9822 Set_Etype (Array_Subtype, Base_Type (Typ));
9823 Set_Is_Constrained (Array_Subtype, True);
9826 Make_Unchecked_Type_Conversion (Loc,
9827 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9828 Expression => Relocate_Node (N)));
9829 Set_Etype (N, Array_Subtype);
9832 end Set_String_Literal_Subtype;
9834 ------------------------------
9835 -- Simplify_Type_Conversion --
9836 ------------------------------
9838 procedure Simplify_Type_Conversion (N : Node_Id) is
9840 if Nkind (N) = N_Type_Conversion then
9842 Operand : constant Node_Id := Expression (N);
9843 Target_Typ : constant Entity_Id := Etype (N);
9844 Opnd_Typ : constant Entity_Id := Etype (Operand);
9847 if Is_Floating_Point_Type (Opnd_Typ)
9849 (Is_Integer_Type (Target_Typ)
9850 or else (Is_Fixed_Point_Type (Target_Typ)
9851 and then Conversion_OK (N)))
9852 and then Nkind (Operand) = N_Attribute_Reference
9853 and then Attribute_Name (Operand) = Name_Truncation
9855 -- Special processing required if the conversion is the expression
9856 -- of a Truncation attribute reference. In this case we replace:
9858 -- ityp (ftyp'Truncation (x))
9864 -- with the Float_Truncate flag set, which is more efficient.
9868 Relocate_Node (First (Expressions (Operand))));
9869 Set_Float_Truncate (N, True);
9873 end Simplify_Type_Conversion;
9875 -----------------------------
9876 -- Unique_Fixed_Point_Type --
9877 -----------------------------
9879 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
9880 T1 : Entity_Id := Empty;
9885 procedure Fixed_Point_Error;
9886 -- Give error messages for true ambiguity. Messages are posted on node
9887 -- N, and entities T1, T2 are the possible interpretations.
9889 -----------------------
9890 -- Fixed_Point_Error --
9891 -----------------------
9893 procedure Fixed_Point_Error is
9895 Error_Msg_N ("ambiguous universal_fixed_expression", N);
9896 Error_Msg_NE ("\\possible interpretation as}", N, T1);
9897 Error_Msg_NE ("\\possible interpretation as}", N, T2);
9898 end Fixed_Point_Error;
9900 -- Start of processing for Unique_Fixed_Point_Type
9903 -- The operations on Duration are visible, so Duration is always a
9904 -- possible interpretation.
9906 T1 := Standard_Duration;
9908 -- Look for fixed-point types in enclosing scopes
9910 Scop := Current_Scope;
9911 while Scop /= Standard_Standard loop
9912 T2 := First_Entity (Scop);
9913 while Present (T2) loop
9914 if Is_Fixed_Point_Type (T2)
9915 and then Current_Entity (T2) = T2
9916 and then Scope (Base_Type (T2)) = Scop
9918 if Present (T1) then
9929 Scop := Scope (Scop);
9932 -- Look for visible fixed type declarations in the context
9934 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
9935 while Present (Item) loop
9936 if Nkind (Item) = N_With_Clause then
9937 Scop := Entity (Name (Item));
9938 T2 := First_Entity (Scop);
9939 while Present (T2) loop
9940 if Is_Fixed_Point_Type (T2)
9941 and then Scope (Base_Type (T2)) = Scop
9942 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
9944 if Present (T1) then
9959 if Nkind (N) = N_Real_Literal then
9960 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9962 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9966 end Unique_Fixed_Point_Type;
9968 ----------------------
9969 -- Valid_Conversion --
9970 ----------------------
9972 function Valid_Conversion
9975 Operand : Node_Id) return Boolean
9977 Target_Type : constant Entity_Id := Base_Type (Target);
9978 Opnd_Type : Entity_Id := Etype (Operand);
9980 function Conversion_Check
9982 Msg : String) return Boolean;
9983 -- Little routine to post Msg if Valid is False, returns Valid value
9985 function Valid_Tagged_Conversion
9986 (Target_Type : Entity_Id;
9987 Opnd_Type : Entity_Id) return Boolean;
9988 -- Specifically test for validity of tagged conversions
9990 function Valid_Array_Conversion return Boolean;
9991 -- Check index and component conformance, and accessibility levels if
9992 -- the component types are anonymous access types (Ada 2005).
9994 ----------------------
9995 -- Conversion_Check --
9996 ----------------------
9998 function Conversion_Check
10000 Msg : String) return Boolean
10004 Error_Msg_N (Msg, Operand);
10008 end Conversion_Check;
10010 ----------------------------
10011 -- Valid_Array_Conversion --
10012 ----------------------------
10014 function Valid_Array_Conversion return Boolean
10016 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
10017 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
10019 Opnd_Index : Node_Id;
10020 Opnd_Index_Type : Entity_Id;
10022 Target_Comp_Type : constant Entity_Id :=
10023 Component_Type (Target_Type);
10024 Target_Comp_Base : constant Entity_Id :=
10025 Base_Type (Target_Comp_Type);
10027 Target_Index : Node_Id;
10028 Target_Index_Type : Entity_Id;
10031 -- Error if wrong number of dimensions
10034 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
10037 ("incompatible number of dimensions for conversion", Operand);
10040 -- Number of dimensions matches
10043 -- Loop through indexes of the two arrays
10045 Target_Index := First_Index (Target_Type);
10046 Opnd_Index := First_Index (Opnd_Type);
10047 while Present (Target_Index) and then Present (Opnd_Index) loop
10048 Target_Index_Type := Etype (Target_Index);
10049 Opnd_Index_Type := Etype (Opnd_Index);
10051 -- Error if index types are incompatible
10053 if not (Is_Integer_Type (Target_Index_Type)
10054 and then Is_Integer_Type (Opnd_Index_Type))
10055 and then (Root_Type (Target_Index_Type)
10056 /= Root_Type (Opnd_Index_Type))
10059 ("incompatible index types for array conversion",
10064 Next_Index (Target_Index);
10065 Next_Index (Opnd_Index);
10068 -- If component types have same base type, all set
10070 if Target_Comp_Base = Opnd_Comp_Base then
10073 -- Here if base types of components are not the same. The only
10074 -- time this is allowed is if we have anonymous access types.
10076 -- The conversion of arrays of anonymous access types can lead
10077 -- to dangling pointers. AI-392 formalizes the accessibility
10078 -- checks that must be applied to such conversions to prevent
10079 -- out-of-scope references.
10082 (Target_Comp_Base, E_Anonymous_Access_Type,
10083 E_Anonymous_Access_Subprogram_Type)
10084 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
10086 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
10088 if Type_Access_Level (Target_Type) <
10089 Type_Access_Level (Opnd_Type)
10091 if In_Instance_Body then
10092 Error_Msg_N ("?source array type " &
10093 "has deeper accessibility level than target", Operand);
10094 Error_Msg_N ("\?Program_Error will be raised at run time",
10097 Make_Raise_Program_Error (Sloc (N),
10098 Reason => PE_Accessibility_Check_Failed));
10099 Set_Etype (N, Target_Type);
10102 -- Conversion not allowed because of accessibility levels
10105 Error_Msg_N ("source array type " &
10106 "has deeper accessibility level than target", Operand);
10114 -- All other cases where component base types do not match
10118 ("incompatible component types for array conversion",
10123 -- Check that component subtypes statically match. For numeric
10124 -- types this means that both must be either constrained or
10125 -- unconstrained. For enumeration types the bounds must match.
10126 -- All of this is checked in Subtypes_Statically_Match.
10128 if not Subtypes_Statically_Match
10129 (Target_Comp_Type, Opnd_Comp_Type)
10132 ("component subtypes must statically match", Operand);
10138 end Valid_Array_Conversion;
10140 -----------------------------
10141 -- Valid_Tagged_Conversion --
10142 -----------------------------
10144 function Valid_Tagged_Conversion
10145 (Target_Type : Entity_Id;
10146 Opnd_Type : Entity_Id) return Boolean
10149 -- Upward conversions are allowed (RM 4.6(22))
10151 if Covers (Target_Type, Opnd_Type)
10152 or else Is_Ancestor (Target_Type, Opnd_Type)
10156 -- Downward conversion are allowed if the operand is class-wide
10159 elsif Is_Class_Wide_Type (Opnd_Type)
10160 and then Covers (Opnd_Type, Target_Type)
10164 elsif Covers (Opnd_Type, Target_Type)
10165 or else Is_Ancestor (Opnd_Type, Target_Type)
10168 Conversion_Check (False,
10169 "downward conversion of tagged objects not allowed");
10171 -- Ada 2005 (AI-251): The conversion to/from interface types is
10174 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
10177 -- If the operand is a class-wide type obtained through a limited_
10178 -- with clause, and the context includes the non-limited view, use
10179 -- it to determine whether the conversion is legal.
10181 elsif Is_Class_Wide_Type (Opnd_Type)
10182 and then From_With_Type (Opnd_Type)
10183 and then Present (Non_Limited_View (Etype (Opnd_Type)))
10184 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
10188 elsif Is_Access_Type (Opnd_Type)
10189 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
10195 ("invalid tagged conversion, not compatible with}",
10196 N, First_Subtype (Opnd_Type));
10199 end Valid_Tagged_Conversion;
10201 -- Start of processing for Valid_Conversion
10204 Check_Parameterless_Call (Operand);
10206 if Is_Overloaded (Operand) then
10216 -- Remove procedure calls, which syntactically cannot appear in
10217 -- this context, but which cannot be removed by type checking,
10218 -- because the context does not impose a type.
10220 -- When compiling for VMS, spurious ambiguities can be produced
10221 -- when arithmetic operations have a literal operand and return
10222 -- System.Address or a descendant of it. These ambiguities are
10223 -- otherwise resolved by the context, but for conversions there
10224 -- is no context type and the removal of the spurious operations
10225 -- must be done explicitly here.
10227 -- The node may be labelled overloaded, but still contain only one
10228 -- interpretation because others were discarded earlier. If this
10229 -- is the case, retain the single interpretation if legal.
10231 Get_First_Interp (Operand, I, It);
10232 Opnd_Type := It.Typ;
10233 Get_Next_Interp (I, It);
10235 if Present (It.Typ)
10236 and then Opnd_Type /= Standard_Void_Type
10238 -- More than one candidate interpretation is available
10240 Get_First_Interp (Operand, I, It);
10241 while Present (It.Typ) loop
10242 if It.Typ = Standard_Void_Type then
10246 if Present (System_Aux_Id)
10247 and then Is_Descendent_Of_Address (It.Typ)
10252 Get_Next_Interp (I, It);
10256 Get_First_Interp (Operand, I, It);
10260 if No (It.Typ) then
10261 Error_Msg_N ("illegal operand in conversion", Operand);
10265 Get_Next_Interp (I, It);
10267 if Present (It.Typ) then
10270 It1 := Disambiguate (Operand, I1, I, Any_Type);
10272 if It1 = No_Interp then
10273 Error_Msg_N ("ambiguous operand in conversion", Operand);
10275 -- If the interpretation involves a standard operator, use
10276 -- the location of the type, which may be user-defined.
10278 if Sloc (It.Nam) = Standard_Location then
10279 Error_Msg_Sloc := Sloc (It.Typ);
10281 Error_Msg_Sloc := Sloc (It.Nam);
10284 Error_Msg_N -- CODEFIX
10285 ("\\possible interpretation#!", Operand);
10287 if Sloc (N1) = Standard_Location then
10288 Error_Msg_Sloc := Sloc (T1);
10290 Error_Msg_Sloc := Sloc (N1);
10293 Error_Msg_N -- CODEFIX
10294 ("\\possible interpretation#!", Operand);
10300 Set_Etype (Operand, It1.Typ);
10301 Opnd_Type := It1.Typ;
10307 if Is_Numeric_Type (Target_Type) then
10309 -- A universal fixed expression can be converted to any numeric type
10311 if Opnd_Type = Universal_Fixed then
10314 -- Also no need to check when in an instance or inlined body, because
10315 -- the legality has been established when the template was analyzed.
10316 -- Furthermore, numeric conversions may occur where only a private
10317 -- view of the operand type is visible at the instantiation point.
10318 -- This results in a spurious error if we check that the operand type
10319 -- is a numeric type.
10321 -- Note: in a previous version of this unit, the following tests were
10322 -- applied only for generated code (Comes_From_Source set to False),
10323 -- but in fact the test is required for source code as well, since
10324 -- this situation can arise in source code.
10326 elsif In_Instance or else In_Inlined_Body then
10329 -- Otherwise we need the conversion check
10332 return Conversion_Check
10333 (Is_Numeric_Type (Opnd_Type),
10334 "illegal operand for numeric conversion");
10339 elsif Is_Array_Type (Target_Type) then
10340 if not Is_Array_Type (Opnd_Type)
10341 or else Opnd_Type = Any_Composite
10342 or else Opnd_Type = Any_String
10344 Error_Msg_N ("illegal operand for array conversion", Operand);
10347 return Valid_Array_Conversion;
10350 -- Ada 2005 (AI-251): Anonymous access types where target references an
10353 elsif Ekind_In (Target_Type, E_General_Access_Type,
10354 E_Anonymous_Access_Type)
10355 and then Is_Interface (Directly_Designated_Type (Target_Type))
10357 -- Check the static accessibility rule of 4.6(17). Note that the
10358 -- check is not enforced when within an instance body, since the
10359 -- RM requires such cases to be caught at run time.
10361 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
10362 if Type_Access_Level (Opnd_Type) >
10363 Type_Access_Level (Target_Type)
10365 -- In an instance, this is a run-time check, but one we know
10366 -- will fail, so generate an appropriate warning. The raise
10367 -- will be generated by Expand_N_Type_Conversion.
10369 if In_Instance_Body then
10371 ("?cannot convert local pointer to non-local access type",
10374 ("\?Program_Error will be raised at run time", Operand);
10377 ("cannot convert local pointer to non-local access type",
10382 -- Special accessibility checks are needed in the case of access
10383 -- discriminants declared for a limited type.
10385 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10386 and then not Is_Local_Anonymous_Access (Opnd_Type)
10388 -- When the operand is a selected access discriminant the check
10389 -- needs to be made against the level of the object denoted by
10390 -- the prefix of the selected name (Object_Access_Level handles
10391 -- checking the prefix of the operand for this case).
10393 if Nkind (Operand) = N_Selected_Component
10394 and then Object_Access_Level (Operand) >
10395 Type_Access_Level (Target_Type)
10397 -- In an instance, this is a run-time check, but one we know
10398 -- will fail, so generate an appropriate warning. The raise
10399 -- will be generated by Expand_N_Type_Conversion.
10401 if In_Instance_Body then
10403 ("?cannot convert access discriminant to non-local" &
10404 " access type", Operand);
10406 ("\?Program_Error will be raised at run time", Operand);
10409 ("cannot convert access discriminant to non-local" &
10410 " access type", Operand);
10415 -- The case of a reference to an access discriminant from
10416 -- within a limited type declaration (which will appear as
10417 -- a discriminal) is always illegal because the level of the
10418 -- discriminant is considered to be deeper than any (nameable)
10421 if Is_Entity_Name (Operand)
10422 and then not Is_Local_Anonymous_Access (Opnd_Type)
10424 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10425 and then Present (Discriminal_Link (Entity (Operand)))
10428 ("discriminant has deeper accessibility level than target",
10437 -- General and anonymous access types
10439 elsif Ekind_In (Target_Type, E_General_Access_Type,
10440 E_Anonymous_Access_Type)
10443 (Is_Access_Type (Opnd_Type)
10445 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
10446 E_Access_Protected_Subprogram_Type),
10447 "must be an access-to-object type")
10449 if Is_Access_Constant (Opnd_Type)
10450 and then not Is_Access_Constant (Target_Type)
10453 ("access-to-constant operand type not allowed", Operand);
10457 -- Check the static accessibility rule of 4.6(17). Note that the
10458 -- check is not enforced when within an instance body, since the RM
10459 -- requires such cases to be caught at run time.
10461 if Ekind (Target_Type) /= E_Anonymous_Access_Type
10462 or else Is_Local_Anonymous_Access (Target_Type)
10464 if Type_Access_Level (Opnd_Type)
10465 > Type_Access_Level (Target_Type)
10467 -- In an instance, this is a run-time check, but one we know
10468 -- will fail, so generate an appropriate warning. The raise
10469 -- will be generated by Expand_N_Type_Conversion.
10471 if In_Instance_Body then
10473 ("?cannot convert local pointer to non-local access type",
10476 ("\?Program_Error will be raised at run time", Operand);
10479 -- Avoid generation of spurious error message
10481 if not Error_Posted (N) then
10483 ("cannot convert local pointer to non-local access type",
10490 -- Special accessibility checks are needed in the case of access
10491 -- discriminants declared for a limited type.
10493 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10494 and then not Is_Local_Anonymous_Access (Opnd_Type)
10496 -- When the operand is a selected access discriminant the check
10497 -- needs to be made against the level of the object denoted by
10498 -- the prefix of the selected name (Object_Access_Level handles
10499 -- checking the prefix of the operand for this case).
10501 if Nkind (Operand) = N_Selected_Component
10502 and then Object_Access_Level (Operand) >
10503 Type_Access_Level (Target_Type)
10505 -- In an instance, this is a run-time check, but one we know
10506 -- will fail, so generate an appropriate warning. The raise
10507 -- will be generated by Expand_N_Type_Conversion.
10509 if In_Instance_Body then
10511 ("?cannot convert access discriminant to non-local" &
10512 " access type", Operand);
10514 ("\?Program_Error will be raised at run time",
10519 ("cannot convert access discriminant to non-local" &
10520 " access type", Operand);
10525 -- The case of a reference to an access discriminant from
10526 -- within a limited type declaration (which will appear as
10527 -- a discriminal) is always illegal because the level of the
10528 -- discriminant is considered to be deeper than any (nameable)
10531 if Is_Entity_Name (Operand)
10533 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10534 and then Present (Discriminal_Link (Entity (Operand)))
10537 ("discriminant has deeper accessibility level than target",
10544 -- In the presence of limited_with clauses we have to use non-limited
10545 -- views, if available.
10547 Check_Limited : declare
10548 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
10549 -- Helper function to handle limited views
10551 --------------------------
10552 -- Full_Designated_Type --
10553 --------------------------
10555 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
10556 Desig : constant Entity_Id := Designated_Type (T);
10559 -- Handle the limited view of a type
10561 if Is_Incomplete_Type (Desig)
10562 and then From_With_Type (Desig)
10563 and then Present (Non_Limited_View (Desig))
10565 return Available_View (Desig);
10569 end Full_Designated_Type;
10571 -- Local Declarations
10573 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
10574 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
10576 Same_Base : constant Boolean :=
10577 Base_Type (Target) = Base_Type (Opnd);
10579 -- Start of processing for Check_Limited
10582 if Is_Tagged_Type (Target) then
10583 return Valid_Tagged_Conversion (Target, Opnd);
10586 if not Same_Base then
10588 ("target designated type not compatible with }",
10589 N, Base_Type (Opnd));
10592 -- Ada 2005 AI-384: legality rule is symmetric in both
10593 -- designated types. The conversion is legal (with possible
10594 -- constraint check) if either designated type is
10597 elsif Subtypes_Statically_Match (Target, Opnd)
10599 (Has_Discriminants (Target)
10601 (not Is_Constrained (Opnd)
10602 or else not Is_Constrained (Target)))
10604 -- Special case, if Value_Size has been used to make the
10605 -- sizes different, the conversion is not allowed even
10606 -- though the subtypes statically match.
10608 if Known_Static_RM_Size (Target)
10609 and then Known_Static_RM_Size (Opnd)
10610 and then RM_Size (Target) /= RM_Size (Opnd)
10613 ("target designated subtype not compatible with }",
10616 ("\because sizes of the two designated subtypes differ",
10620 -- Normal case where conversion is allowed
10628 ("target designated subtype not compatible with }",
10635 -- Access to subprogram types. If the operand is an access parameter,
10636 -- the type has a deeper accessibility that any master, and cannot be
10637 -- assigned. We must make an exception if the conversion is part of an
10638 -- assignment and the target is the return object of an extended return
10639 -- statement, because in that case the accessibility check takes place
10640 -- after the return.
10642 elsif Is_Access_Subprogram_Type (Target_Type)
10643 and then No (Corresponding_Remote_Type (Opnd_Type))
10645 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
10646 and then Is_Entity_Name (Operand)
10647 and then Ekind (Entity (Operand)) = E_In_Parameter
10649 (Nkind (Parent (N)) /= N_Assignment_Statement
10650 or else not Is_Entity_Name (Name (Parent (N)))
10651 or else not Is_Return_Object (Entity (Name (Parent (N)))))
10654 ("illegal attempt to store anonymous access to subprogram",
10657 ("\value has deeper accessibility than any master " &
10658 "(RM 3.10.2 (13))",
10662 ("\use named access type for& instead of access parameter",
10663 Operand, Entity (Operand));
10666 -- Check that the designated types are subtype conformant
10668 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
10669 Old_Id => Designated_Type (Opnd_Type),
10672 -- Check the static accessibility rule of 4.6(20)
10674 if Type_Access_Level (Opnd_Type) >
10675 Type_Access_Level (Target_Type)
10678 ("operand type has deeper accessibility level than target",
10681 -- Check that if the operand type is declared in a generic body,
10682 -- then the target type must be declared within that same body
10683 -- (enforces last sentence of 4.6(20)).
10685 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
10687 O_Gen : constant Node_Id :=
10688 Enclosing_Generic_Body (Opnd_Type);
10693 T_Gen := Enclosing_Generic_Body (Target_Type);
10694 while Present (T_Gen) and then T_Gen /= O_Gen loop
10695 T_Gen := Enclosing_Generic_Body (T_Gen);
10698 if T_Gen /= O_Gen then
10700 ("target type must be declared in same generic body"
10701 & " as operand type", N);
10708 -- Remote subprogram access types
10710 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
10711 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
10713 -- It is valid to convert from one RAS type to another provided
10714 -- that their specification statically match.
10716 Check_Subtype_Conformant
10718 Designated_Type (Corresponding_Remote_Type (Target_Type)),
10720 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
10725 -- If both are tagged types, check legality of view conversions
10727 elsif Is_Tagged_Type (Target_Type)
10729 Is_Tagged_Type (Opnd_Type)
10731 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
10733 -- Types derived from the same root type are convertible
10735 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
10738 -- In an instance or an inlined body, there may be inconsistent views of
10739 -- the same type, or of types derived from a common root.
10741 elsif (In_Instance or In_Inlined_Body)
10743 Root_Type (Underlying_Type (Target_Type)) =
10744 Root_Type (Underlying_Type (Opnd_Type))
10748 -- Special check for common access type error case
10750 elsif Ekind (Target_Type) = E_Access_Type
10751 and then Is_Access_Type (Opnd_Type)
10753 Error_Msg_N ("target type must be general access type!", N);
10754 Error_Msg_NE -- CODEFIX
10755 ("add ALL to }!", N, Target_Type);
10759 Error_Msg_NE ("invalid conversion, not compatible with }",
10763 end Valid_Conversion;
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