1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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 Elists; use Elists;
32 with Errout; use Errout;
33 with Expander; use Expander;
34 with Exp_Disp; use Exp_Disp;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Tss; use Exp_Tss;
38 with Exp_Util; use Exp_Util;
39 with Fname; use Fname;
40 with Freeze; use Freeze;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch4; use Sem_Ch4;
58 with Sem_Ch6; use Sem_Ch6;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch10; use Sem_Ch10;
61 with Sem_Ch13; use Sem_Ch13;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Elim; use Sem_Elim;
65 with Sem_Elab; use Sem_Elab;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Intr; use Sem_Intr;
68 with Sem_Util; use Sem_Util;
69 with Sem_Type; use Sem_Type;
70 with Sem_Warn; use Sem_Warn;
71 with Sinfo; use Sinfo;
72 with Snames; use Snames;
73 with Stand; use Stand;
74 with Stringt; use Stringt;
75 with Style; use Style;
76 with Tbuild; use Tbuild;
77 with Uintp; use Uintp;
78 with Urealp; use Urealp;
80 package body Sem_Res is
82 -----------------------
83 -- Local Subprograms --
84 -----------------------
86 -- Second pass (top-down) type checking and overload resolution procedures
87 -- Typ is the type required by context. These procedures propagate the
88 -- type information recursively to the descendants of N. If the node
89 -- is not overloaded, its Etype is established in the first pass. If
90 -- overloaded, the Resolve routines set the correct type. For arith.
91 -- operators, the Etype is the base type of the context.
93 -- Note that Resolve_Attribute is separated off in Sem_Attr
95 procedure Check_Discriminant_Use (N : Node_Id);
96 -- Enforce the restrictions on the use of discriminants when constraining
97 -- a component of a discriminated type (record or concurrent type).
99 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
100 -- Given a node for an operator associated with type T, check that
101 -- the operator is visible. Operators all of whose operands are
102 -- universal must be checked for visibility during resolution
103 -- because their type is not determinable based on their operands.
105 procedure Check_Fully_Declared_Prefix
108 -- Check that the type of the prefix of a dereference is not incomplete
110 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
111 -- Given a call node, N, which is known to occur immediately within the
112 -- subprogram being called, determines whether it is a detectable case of
113 -- an infinite recursion, and if so, outputs appropriate messages. Returns
114 -- True if an infinite recursion is detected, and False otherwise.
116 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
117 -- If the type of the object being initialized uses the secondary stack
118 -- directly or indirectly, create a transient scope for the call to the
119 -- init proc. This is because we do not create transient scopes for the
120 -- initialization of individual components within the init proc itself.
121 -- Could be optimized away perhaps?
123 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
124 -- N is the node for a comparison or logical operator. If the operator
125 -- is predefined, and the root type of the operands is Standard.Boolean,
126 -- then a check is made for restriction No_Direct_Boolean_Operators.
128 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
129 -- Determine whether E is an access type declared by an access
130 -- declaration, and not an (anonymous) allocator type.
132 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
133 -- Utility to check whether the name in the call is a predefined
134 -- operator, in which case the call is made into an operator node.
135 -- An instance of an intrinsic conversion operation may be given
136 -- an operator name, but is not treated like an operator.
138 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
139 -- If a default expression in entry call N depends on the discriminants
140 -- of the task, it must be replaced with a reference to the discriminant
141 -- of the task being called.
143 procedure Resolve_Op_Concat_Arg
148 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
149 -- concatenation operator. The operand is either of the array type or of
150 -- the component type. If the operand is an aggregate, and the component
151 -- type is composite, this is ambiguous if component type has aggregates.
153 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
154 -- Does the first part of the work of Resolve_Op_Concat
156 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
157 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
158 -- has been resolved. See Resolve_Op_Concat for details.
160 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
164 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
165 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
166 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
193 function Operator_Kind
195 Is_Binary : Boolean) return Node_Kind;
196 -- Utility to map the name of an operator into the corresponding Node. Used
197 -- by other node rewriting procedures.
199 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
200 -- Resolve actuals of call, and add default expressions for missing ones.
201 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
202 -- called subprogram.
204 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
205 -- Called from Resolve_Call, when the prefix denotes an entry or element
206 -- of entry family. Actuals are resolved as for subprograms, and the node
207 -- is rebuilt as an entry call. Also called for protected operations. Typ
208 -- is the context type, which is used when the operation is a protected
209 -- function with no arguments, and the return value is indexed.
211 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
212 -- A call to a user-defined intrinsic operator is rewritten as a call
213 -- to the corresponding predefined operator, with suitable conversions.
215 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
216 -- Ditto, for unary operators (only arithmetic ones)
218 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
219 -- If an operator node resolves to a call to a user-defined operator,
220 -- rewrite the node as a function call.
222 procedure Make_Call_Into_Operator
226 -- Inverse transformation: if an operator is given in functional notation,
227 -- then after resolving the node, transform into an operator node, so
228 -- that operands are resolved properly. Recall that predefined operators
229 -- do not have a full signature and special resolution rules apply.
231 procedure Rewrite_Renamed_Operator
235 -- An operator can rename another, e.g. in an instantiation. In that
236 -- case, the proper operator node must be constructed and resolved.
238 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
239 -- The String_Literal_Subtype is built for all strings that are not
240 -- operands of a static concatenation operation. If the argument is
241 -- not a N_String_Literal node, then the call has no effect.
243 procedure Set_Slice_Subtype (N : Node_Id);
244 -- Build subtype of array type, with the range specified by the slice
246 procedure Simplify_Type_Conversion (N : Node_Id);
247 -- Called after N has been resolved and evaluated, but before range checks
248 -- have been applied. Currently simplifies a combination of floating-point
249 -- to integer conversion and Truncation attribute.
251 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
252 -- A universal_fixed expression in an universal context is unambiguous
253 -- if there is only one applicable fixed point type. Determining whether
254 -- there is only one requires a search over all visible entities, and
255 -- happens only in very pathological cases (see 6115-006).
257 function Valid_Conversion
260 Operand : Node_Id) return Boolean;
261 -- Verify legality rules given in 4.6 (8-23). Target is the target
262 -- type of the conversion, which may be an implicit conversion of
263 -- an actual parameter to an anonymous access type (in which case
264 -- N denotes the actual parameter and N = Operand).
266 -------------------------
267 -- Ambiguous_Character --
268 -------------------------
270 procedure Ambiguous_Character (C : Node_Id) is
274 if Nkind (C) = N_Character_Literal then
275 Error_Msg_N ("ambiguous character literal", C);
277 -- First the ones in Standard
280 ("\\possible interpretation: Character!", C);
282 ("\\possible interpretation: Wide_Character!", C);
284 -- Include Wide_Wide_Character in Ada 2005 mode
286 if Ada_Version >= Ada_05 then
288 ("\\possible interpretation: Wide_Wide_Character!", C);
291 -- Now any other types that match
293 E := Current_Entity (C);
294 while Present (E) loop
295 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
299 end Ambiguous_Character;
301 -------------------------
302 -- Analyze_And_Resolve --
303 -------------------------
305 procedure Analyze_And_Resolve (N : Node_Id) is
309 end Analyze_And_Resolve;
311 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
315 end Analyze_And_Resolve;
317 -- Version withs check(s) suppressed
319 procedure Analyze_And_Resolve
324 Scop : constant Entity_Id := Current_Scope;
327 if Suppress = All_Checks then
329 Svg : constant Suppress_Array := Scope_Suppress;
331 Scope_Suppress := (others => True);
332 Analyze_And_Resolve (N, Typ);
333 Scope_Suppress := Svg;
338 Svg : constant Boolean := Scope_Suppress (Suppress);
341 Scope_Suppress (Suppress) := True;
342 Analyze_And_Resolve (N, Typ);
343 Scope_Suppress (Suppress) := Svg;
347 if Current_Scope /= Scop
348 and then Scope_Is_Transient
350 -- This can only happen if a transient scope was created
351 -- for an inner expression, which will be removed upon
352 -- completion of the analysis of an enclosing construct.
353 -- The transient scope must have the suppress status of
354 -- the enclosing environment, not of this Analyze call.
356 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
359 end Analyze_And_Resolve;
361 procedure Analyze_And_Resolve
365 Scop : constant Entity_Id := Current_Scope;
368 if Suppress = All_Checks then
370 Svg : constant Suppress_Array := Scope_Suppress;
372 Scope_Suppress := (others => True);
373 Analyze_And_Resolve (N);
374 Scope_Suppress := Svg;
379 Svg : constant Boolean := Scope_Suppress (Suppress);
382 Scope_Suppress (Suppress) := True;
383 Analyze_And_Resolve (N);
384 Scope_Suppress (Suppress) := Svg;
388 if Current_Scope /= Scop
389 and then Scope_Is_Transient
391 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
394 end Analyze_And_Resolve;
396 ----------------------------
397 -- Check_Discriminant_Use --
398 ----------------------------
400 procedure Check_Discriminant_Use (N : Node_Id) is
401 PN : constant Node_Id := Parent (N);
402 Disc : constant Entity_Id := Entity (N);
407 -- Any use in a spec-expression is legal
409 if In_Spec_Expression then
412 elsif Nkind (PN) = N_Range then
414 -- Discriminant cannot be used to constrain a scalar type
418 if Nkind (P) = N_Range_Constraint
419 and then Nkind (Parent (P)) = N_Subtype_Indication
420 and then Nkind (Parent (Parent (P))) = N_Component_Definition
422 Error_Msg_N ("discriminant cannot constrain scalar type", N);
424 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
426 -- The following check catches the unusual case where
427 -- a discriminant appears within an index constraint
428 -- that is part of a larger expression within a constraint
429 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
430 -- For now we only check case of record components, and
431 -- note that a similar check should also apply in the
432 -- case of discriminant constraints below. ???
434 -- Note that the check for N_Subtype_Declaration below is to
435 -- detect the valid use of discriminants in the constraints of a
436 -- subtype declaration when this subtype declaration appears
437 -- inside the scope of a record type (which is syntactically
438 -- illegal, but which may be created as part of derived type
439 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
442 if Ekind (Current_Scope) = E_Record_Type
443 and then Scope (Disc) = Current_Scope
445 (Nkind (Parent (P)) = N_Subtype_Indication
447 Nkind_In (Parent (Parent (P)), N_Component_Definition,
448 N_Subtype_Declaration)
449 and then Paren_Count (N) = 0)
452 ("discriminant must appear alone in component constraint", N);
456 -- Detect a common error:
458 -- type R (D : Positive := 100) is record
459 -- Name : String (1 .. D);
462 -- The default value causes an object of type R to be allocated
463 -- with room for Positive'Last characters. The RM does not mandate
464 -- the allocation of the maximum size, but that is what GNAT does
465 -- so we should warn the programmer that there is a problem.
467 Check_Large : declare
473 function Large_Storage_Type (T : Entity_Id) return Boolean;
474 -- Return True if type T has a large enough range that
475 -- any array whose index type covered the whole range of
476 -- the type would likely raise Storage_Error.
478 ------------------------
479 -- Large_Storage_Type --
480 ------------------------
482 function Large_Storage_Type (T : Entity_Id) return Boolean is
484 -- The type is considered large if its bounds are known at
485 -- compile time and if it requires at least as many bits as
486 -- a Positive to store the possible values.
488 return Compile_Time_Known_Value (Type_Low_Bound (T))
489 and then Compile_Time_Known_Value (Type_High_Bound (T))
491 Minimum_Size (T, Biased => True) >=
492 RM_Size (Standard_Positive);
493 end Large_Storage_Type;
495 -- Start of processing for Check_Large
498 -- Check that the Disc has a large range
500 if not Large_Storage_Type (Etype (Disc)) then
504 -- If the enclosing type is limited, we allocate only the
505 -- default value, not the maximum, and there is no need for
508 if Is_Limited_Type (Scope (Disc)) then
512 -- Check that it is the high bound
514 if N /= High_Bound (PN)
515 or else No (Discriminant_Default_Value (Disc))
520 -- Check the array allows a large range at this bound.
521 -- First find the array
525 if Nkind (SI) /= N_Subtype_Indication then
529 T := Entity (Subtype_Mark (SI));
531 if not Is_Array_Type (T) then
535 -- Next, find the dimension
537 TB := First_Index (T);
538 CB := First (Constraints (P));
540 and then Present (TB)
541 and then Present (CB)
552 -- Now, check the dimension has a large range
554 if not Large_Storage_Type (Etype (TB)) then
558 -- Warn about the danger
561 ("?creation of & object may raise Storage_Error!",
570 -- Legal case is in index or discriminant constraint
572 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
573 N_Discriminant_Association)
575 if Paren_Count (N) > 0 then
577 ("discriminant in constraint must appear alone", N);
579 elsif Nkind (N) = N_Expanded_Name
580 and then Comes_From_Source (N)
583 ("discriminant must appear alone as a direct name", N);
588 -- Otherwise, context is an expression. It should not be within
589 -- (i.e. a subexpression of) a constraint for a component.
594 while not Nkind_In (P, N_Component_Declaration,
595 N_Subtype_Indication,
603 -- If the discriminant is used in an expression that is a bound
604 -- of a scalar type, an Itype is created and the bounds are attached
605 -- to its range, not to the original subtype indication. Such use
606 -- is of course a double fault.
608 if (Nkind (P) = N_Subtype_Indication
609 and then Nkind_In (Parent (P), N_Component_Definition,
610 N_Derived_Type_Definition)
611 and then D = Constraint (P))
613 -- The constraint itself may be given by a subtype indication,
614 -- rather than by a more common discrete range.
616 or else (Nkind (P) = N_Subtype_Indication
618 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
619 or else Nkind (P) = N_Entry_Declaration
620 or else Nkind (D) = N_Defining_Identifier
623 ("discriminant in constraint must appear alone", N);
626 end Check_Discriminant_Use;
628 --------------------------------
629 -- Check_For_Visible_Operator --
630 --------------------------------
632 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
634 if Is_Invisible_Operator (N, T) then
636 ("operator for} is not directly visible!", N, First_Subtype (T));
637 Error_Msg_N ("use clause would make operation legal!", N);
639 end Check_For_Visible_Operator;
641 ----------------------------------
642 -- Check_Fully_Declared_Prefix --
643 ----------------------------------
645 procedure Check_Fully_Declared_Prefix
650 -- Check that the designated type of the prefix of a dereference is
651 -- not an incomplete type. This cannot be done unconditionally, because
652 -- dereferences of private types are legal in default expressions. This
653 -- case is taken care of in Check_Fully_Declared, called below. There
654 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
656 -- This consideration also applies to similar checks for allocators,
657 -- qualified expressions, and type conversions.
659 -- An additional exception concerns other per-object expressions that
660 -- are not directly related to component declarations, in particular
661 -- representation pragmas for tasks. These will be per-object
662 -- expressions if they depend on discriminants or some global entity.
663 -- If the task has access discriminants, the designated type may be
664 -- incomplete at the point the expression is resolved. This resolution
665 -- takes place within the body of the initialization procedure, where
666 -- the discriminant is replaced by its discriminal.
668 if Is_Entity_Name (Pref)
669 and then Ekind (Entity (Pref)) = E_In_Parameter
673 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
674 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
675 -- Analyze_Object_Renaming, and Freeze_Entity.
677 elsif Ada_Version >= Ada_05
678 and then Is_Entity_Name (Pref)
679 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
681 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
685 Check_Fully_Declared (Typ, Parent (Pref));
687 end Check_Fully_Declared_Prefix;
689 ------------------------------
690 -- Check_Infinite_Recursion --
691 ------------------------------
693 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
697 function Same_Argument_List return Boolean;
698 -- Check whether list of actuals is identical to list of formals
699 -- of called function (which is also the enclosing scope).
701 ------------------------
702 -- Same_Argument_List --
703 ------------------------
705 function Same_Argument_List return Boolean is
711 if not Is_Entity_Name (Name (N)) then
714 Subp := Entity (Name (N));
717 F := First_Formal (Subp);
718 A := First_Actual (N);
719 while Present (F) and then Present (A) loop
720 if not Is_Entity_Name (A)
721 or else Entity (A) /= F
731 end Same_Argument_List;
733 -- Start of processing for Check_Infinite_Recursion
736 -- Special case, if this is a procedure call and is a call to the
737 -- current procedure with the same argument list, then this is for
738 -- sure an infinite recursion and we insert a call to raise SE.
740 if Is_List_Member (N)
741 and then List_Length (List_Containing (N)) = 1
742 and then Same_Argument_List
745 P : constant Node_Id := Parent (N);
747 if Nkind (P) = N_Handled_Sequence_Of_Statements
748 and then Nkind (Parent (P)) = N_Subprogram_Body
749 and then Is_Empty_List (Declarations (Parent (P)))
751 Error_Msg_N ("!?infinite recursion", N);
752 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
754 Make_Raise_Storage_Error (Sloc (N),
755 Reason => SE_Infinite_Recursion));
761 -- If not that special case, search up tree, quitting if we reach a
762 -- construct (e.g. a conditional) that tells us that this is not a
763 -- case for an infinite recursion warning.
769 -- If no parent, then we were not inside a subprogram, this can for
770 -- example happen when processing certain pragmas in a spec. Just
771 -- return False in this case.
777 -- Done if we get to subprogram body, this is definitely an infinite
778 -- recursion case if we did not find anything to stop us.
780 exit when Nkind (P) = N_Subprogram_Body;
782 -- If appearing in conditional, result is false
784 if Nkind_In (P, N_Or_Else,
791 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
792 and then C /= First (Statements (P))
794 -- If the call is the expression of a return statement and the
795 -- actuals are identical to the formals, it's worth a warning.
796 -- However, we skip this if there is an immediately preceding
797 -- raise statement, since the call is never executed.
799 -- Furthermore, this corresponds to a common idiom:
801 -- function F (L : Thing) return Boolean is
803 -- raise Program_Error;
807 -- for generating a stub function
809 if Nkind (Parent (N)) = N_Simple_Return_Statement
810 and then Same_Argument_List
812 exit when not Is_List_Member (Parent (N));
814 -- OK, return statement is in a statement list, look for raise
820 -- Skip past N_Freeze_Entity nodes generated by expansion
822 Nod := Prev (Parent (N));
824 and then Nkind (Nod) = N_Freeze_Entity
829 -- If no raise statement, give warning
831 exit when Nkind (Nod) /= N_Raise_Statement
833 (Nkind (Nod) not in N_Raise_xxx_Error
834 or else Present (Condition (Nod)));
845 Error_Msg_N ("!?possible infinite recursion", N);
846 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
849 end Check_Infinite_Recursion;
851 -------------------------------
852 -- Check_Initialization_Call --
853 -------------------------------
855 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
856 Typ : constant Entity_Id := Etype (First_Formal (Nam));
858 function Uses_SS (T : Entity_Id) return Boolean;
859 -- Check whether the creation of an object of the type will involve
860 -- use of the secondary stack. If T is a record type, this is true
861 -- if the expression for some component uses the secondary stack, e.g.
862 -- through a call to a function that returns an unconstrained value.
863 -- False if T is controlled, because cleanups occur elsewhere.
869 function Uses_SS (T : Entity_Id) return Boolean is
872 Full_Type : Entity_Id := Underlying_Type (T);
875 -- Normally we want to use the underlying type, but if it's not set
876 -- then continue with T.
878 if not Present (Full_Type) then
882 if Is_Controlled (Full_Type) then
885 elsif Is_Array_Type (Full_Type) then
886 return Uses_SS (Component_Type (Full_Type));
888 elsif Is_Record_Type (Full_Type) then
889 Comp := First_Component (Full_Type);
890 while Present (Comp) loop
891 if Ekind (Comp) = E_Component
892 and then Nkind (Parent (Comp)) = N_Component_Declaration
894 -- The expression for a dynamic component may be rewritten
895 -- as a dereference, so retrieve original node.
897 Expr := Original_Node (Expression (Parent (Comp)));
899 -- Return True if the expression is a call to a function
900 -- (including an attribute function such as Image) with
901 -- a result that requires a transient scope.
903 if (Nkind (Expr) = N_Function_Call
904 or else (Nkind (Expr) = N_Attribute_Reference
905 and then Present (Expressions (Expr))))
906 and then Requires_Transient_Scope (Etype (Expr))
910 elsif Uses_SS (Etype (Comp)) then
915 Next_Component (Comp);
925 -- Start of processing for Check_Initialization_Call
928 -- Establish a transient scope if the type needs it
930 if Uses_SS (Typ) then
931 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
933 end Check_Initialization_Call;
935 ---------------------------------------
936 -- Check_No_Direct_Boolean_Operators --
937 ---------------------------------------
939 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
941 if Scope (Entity (N)) = Standard_Standard
942 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
944 -- Restriction does not apply to generated code
946 if not Comes_From_Source (N) then
949 -- Restriction does not apply for A=False, A=True
951 elsif Nkind (N) = N_Op_Eq
952 and then (Is_Entity_Name (Right_Opnd (N))
953 and then (Entity (Right_Opnd (N)) = Standard_True
955 Entity (Right_Opnd (N)) = Standard_False))
959 -- Otherwise restriction applies
962 Check_Restriction (No_Direct_Boolean_Operators, N);
965 end Check_No_Direct_Boolean_Operators;
967 ------------------------------
968 -- Check_Parameterless_Call --
969 ------------------------------
971 procedure Check_Parameterless_Call (N : Node_Id) is
974 function Prefix_Is_Access_Subp return Boolean;
975 -- If the prefix is of an access_to_subprogram type, the node must be
976 -- rewritten as a call. Ditto if the prefix is overloaded and all its
977 -- interpretations are access to subprograms.
979 ---------------------------
980 -- Prefix_Is_Access_Subp --
981 ---------------------------
983 function Prefix_Is_Access_Subp return Boolean is
988 if not Is_Overloaded (N) then
990 Ekind (Etype (N)) = E_Subprogram_Type
991 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
993 Get_First_Interp (N, I, It);
994 while Present (It.Typ) loop
995 if Ekind (It.Typ) /= E_Subprogram_Type
996 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1001 Get_Next_Interp (I, It);
1006 end Prefix_Is_Access_Subp;
1008 -- Start of processing for Check_Parameterless_Call
1011 -- Defend against junk stuff if errors already detected
1013 if Total_Errors_Detected /= 0 then
1014 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1016 elsif Nkind (N) in N_Has_Chars
1017 and then Chars (N) in Error_Name_Or_No_Name
1025 -- If the context expects a value, and the name is a procedure, this is
1026 -- most likely a missing 'Access. Don't try to resolve the parameterless
1027 -- call, error will be caught when the outer call is analyzed.
1029 if Is_Entity_Name (N)
1030 and then Ekind (Entity (N)) = E_Procedure
1031 and then not Is_Overloaded (N)
1033 Nkind_In (Parent (N), N_Parameter_Association,
1035 N_Procedure_Call_Statement)
1040 -- Rewrite as call if overloadable entity that is (or could be, in the
1041 -- overloaded case) a function call. If we know for sure that the entity
1042 -- is an enumeration literal, we do not rewrite it.
1044 if (Is_Entity_Name (N)
1045 and then Is_Overloadable (Entity (N))
1046 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1047 or else Is_Overloaded (N)))
1049 -- Rewrite as call if it is an explicit deference of an expression of
1050 -- a subprogram access type, and the subprogram type is not that of a
1051 -- procedure or entry.
1054 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1056 -- Rewrite as call if it is a selected component which is a function,
1057 -- this is the case of a call to a protected function (which may be
1058 -- overloaded with other protected operations).
1061 (Nkind (N) = N_Selected_Component
1062 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1064 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1066 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1067 and then Is_Overloaded (Selector_Name (N)))))
1069 -- If one of the above three conditions is met, rewrite as call.
1070 -- Apply the rewriting only once.
1073 if Nkind (Parent (N)) /= N_Function_Call
1074 or else N /= Name (Parent (N))
1076 Nam := New_Copy (N);
1078 -- If overloaded, overload set belongs to new copy
1080 Save_Interps (N, Nam);
1082 -- Change node to parameterless function call (note that the
1083 -- Parameter_Associations associations field is left set to Empty,
1084 -- its normal default value since there are no parameters)
1086 Change_Node (N, N_Function_Call);
1088 Set_Sloc (N, Sloc (Nam));
1092 elsif Nkind (N) = N_Parameter_Association then
1093 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1095 end Check_Parameterless_Call;
1097 -----------------------------
1098 -- Is_Definite_Access_Type --
1099 -----------------------------
1101 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1102 Btyp : constant Entity_Id := Base_Type (E);
1104 return Ekind (Btyp) = E_Access_Type
1105 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1106 and then Comes_From_Source (Btyp));
1107 end Is_Definite_Access_Type;
1109 ----------------------
1110 -- Is_Predefined_Op --
1111 ----------------------
1113 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1115 return Is_Intrinsic_Subprogram (Nam)
1116 and then not Is_Generic_Instance (Nam)
1117 and then Chars (Nam) in Any_Operator_Name
1118 and then (No (Alias (Nam))
1119 or else Is_Predefined_Op (Alias (Nam)));
1120 end Is_Predefined_Op;
1122 -----------------------------
1123 -- Make_Call_Into_Operator --
1124 -----------------------------
1126 procedure Make_Call_Into_Operator
1131 Op_Name : constant Name_Id := Chars (Op_Id);
1132 Act1 : Node_Id := First_Actual (N);
1133 Act2 : Node_Id := Next_Actual (Act1);
1134 Error : Boolean := False;
1135 Func : constant Entity_Id := Entity (Name (N));
1136 Is_Binary : constant Boolean := Present (Act2);
1138 Opnd_Type : Entity_Id;
1139 Orig_Type : Entity_Id := Empty;
1142 type Kind_Test is access function (E : Entity_Id) return Boolean;
1144 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1145 -- If the operand is not universal, and the operator is given by a
1146 -- expanded name, verify that the operand has an interpretation with
1147 -- a type defined in the given scope of the operator.
1149 function Type_In_P (Test : Kind_Test) return Entity_Id;
1150 -- Find a type of the given class in the package Pack that contains
1153 ---------------------------
1154 -- Operand_Type_In_Scope --
1155 ---------------------------
1157 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1158 Nod : constant Node_Id := Right_Opnd (Op_Node);
1163 if not Is_Overloaded (Nod) then
1164 return Scope (Base_Type (Etype (Nod))) = S;
1167 Get_First_Interp (Nod, I, It);
1168 while Present (It.Typ) loop
1169 if Scope (Base_Type (It.Typ)) = S then
1173 Get_Next_Interp (I, It);
1178 end Operand_Type_In_Scope;
1184 function Type_In_P (Test : Kind_Test) return Entity_Id is
1187 function In_Decl return Boolean;
1188 -- Verify that node is not part of the type declaration for the
1189 -- candidate type, which would otherwise be invisible.
1195 function In_Decl return Boolean is
1196 Decl_Node : constant Node_Id := Parent (E);
1202 if Etype (E) = Any_Type then
1205 elsif No (Decl_Node) then
1210 and then Nkind (N2) /= N_Compilation_Unit
1212 if N2 = Decl_Node then
1223 -- Start of processing for Type_In_P
1226 -- If the context type is declared in the prefix package, this
1227 -- is the desired base type.
1229 if Scope (Base_Type (Typ)) = Pack
1232 return Base_Type (Typ);
1235 E := First_Entity (Pack);
1236 while Present (E) loop
1238 and then not In_Decl
1250 -- Start of processing for Make_Call_Into_Operator
1253 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1258 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1259 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1260 Save_Interps (Act1, Left_Opnd (Op_Node));
1261 Save_Interps (Act2, Right_Opnd (Op_Node));
1262 Act1 := Left_Opnd (Op_Node);
1263 Act2 := Right_Opnd (Op_Node);
1268 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1269 Save_Interps (Act1, Right_Opnd (Op_Node));
1270 Act1 := Right_Opnd (Op_Node);
1273 -- If the operator is denoted by an expanded name, and the prefix is
1274 -- not Standard, but the operator is a predefined one whose scope is
1275 -- Standard, then this is an implicit_operator, inserted as an
1276 -- interpretation by the procedure of the same name. This procedure
1277 -- overestimates the presence of implicit operators, because it does
1278 -- not examine the type of the operands. Verify now that the operand
1279 -- type appears in the given scope. If right operand is universal,
1280 -- check the other operand. In the case of concatenation, either
1281 -- argument can be the component type, so check the type of the result.
1282 -- If both arguments are literals, look for a type of the right kind
1283 -- defined in the given scope. This elaborate nonsense is brought to
1284 -- you courtesy of b33302a. The type itself must be frozen, so we must
1285 -- find the type of the proper class in the given scope.
1287 -- A final wrinkle is the multiplication operator for fixed point
1288 -- types, which is defined in Standard only, and not in the scope of
1289 -- the fixed_point type itself.
1291 if Nkind (Name (N)) = N_Expanded_Name then
1292 Pack := Entity (Prefix (Name (N)));
1294 -- If the entity being called is defined in the given package,
1295 -- it is a renaming of a predefined operator, and known to be
1298 if Scope (Entity (Name (N))) = Pack
1299 and then Pack /= Standard_Standard
1303 -- Visibility does not need to be checked in an instance: if the
1304 -- operator was not visible in the generic it has been diagnosed
1305 -- already, else there is an implicit copy of it in the instance.
1307 elsif In_Instance then
1310 elsif (Op_Name = Name_Op_Multiply
1311 or else Op_Name = Name_Op_Divide)
1312 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1313 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1315 if Pack /= Standard_Standard then
1319 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1322 elsif Ada_Version >= Ada_05
1323 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1324 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1329 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1331 if Op_Name = Name_Op_Concat then
1332 Opnd_Type := Base_Type (Typ);
1334 elsif (Scope (Opnd_Type) = Standard_Standard
1336 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1338 and then not Comes_From_Source (Opnd_Type))
1340 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1343 if Scope (Opnd_Type) = Standard_Standard then
1345 -- Verify that the scope contains a type that corresponds to
1346 -- the given literal. Optimize the case where Pack is Standard.
1348 if Pack /= Standard_Standard then
1350 if Opnd_Type = Universal_Integer then
1351 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1353 elsif Opnd_Type = Universal_Real then
1354 Orig_Type := Type_In_P (Is_Real_Type'Access);
1356 elsif Opnd_Type = Any_String then
1357 Orig_Type := Type_In_P (Is_String_Type'Access);
1359 elsif Opnd_Type = Any_Access then
1360 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1362 elsif Opnd_Type = Any_Composite then
1363 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1365 if Present (Orig_Type) then
1366 if Has_Private_Component (Orig_Type) then
1369 Set_Etype (Act1, Orig_Type);
1372 Set_Etype (Act2, Orig_Type);
1381 Error := No (Orig_Type);
1384 elsif Ekind (Opnd_Type) = E_Allocator_Type
1385 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1389 -- If the type is defined elsewhere, and the operator is not
1390 -- defined in the given scope (by a renaming declaration, e.g.)
1391 -- then this is an error as well. If an extension of System is
1392 -- present, and the type may be defined there, Pack must be
1395 elsif Scope (Opnd_Type) /= Pack
1396 and then Scope (Op_Id) /= Pack
1397 and then (No (System_Aux_Id)
1398 or else Scope (Opnd_Type) /= System_Aux_Id
1399 or else Pack /= Scope (System_Aux_Id))
1401 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1404 Error := not Operand_Type_In_Scope (Pack);
1407 elsif Pack = Standard_Standard
1408 and then not Operand_Type_In_Scope (Standard_Standard)
1415 Error_Msg_Node_2 := Pack;
1417 ("& not declared in&", N, Selector_Name (Name (N)));
1418 Set_Etype (N, Any_Type);
1423 Set_Chars (Op_Node, Op_Name);
1425 if not Is_Private_Type (Etype (N)) then
1426 Set_Etype (Op_Node, Base_Type (Etype (N)));
1428 Set_Etype (Op_Node, Etype (N));
1431 -- If this is a call to a function that renames a predefined equality,
1432 -- the renaming declaration provides a type that must be used to
1433 -- resolve the operands. This must be done now because resolution of
1434 -- the equality node will not resolve any remaining ambiguity, and it
1435 -- assumes that the first operand is not overloaded.
1437 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1438 and then Ekind (Func) = E_Function
1439 and then Is_Overloaded (Act1)
1441 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1442 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1445 Set_Entity (Op_Node, Op_Id);
1446 Generate_Reference (Op_Id, N, ' ');
1448 -- Do rewrite setting Comes_From_Source on the result if the original
1449 -- call came from source. Although it is not strictly the case that the
1450 -- operator as such comes from the source, logically it corresponds
1451 -- exactly to the function call in the source, so it should be marked
1452 -- this way (e.g. to make sure that validity checks work fine).
1455 CS : constant Boolean := Comes_From_Source (N);
1457 Rewrite (N, Op_Node);
1458 Set_Comes_From_Source (N, CS);
1461 -- If this is an arithmetic operator and the result type is private,
1462 -- the operands and the result must be wrapped in conversion to
1463 -- expose the underlying numeric type and expand the proper checks,
1464 -- e.g. on division.
1466 if Is_Private_Type (Typ) then
1468 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1469 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1470 Resolve_Intrinsic_Operator (N, Typ);
1472 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1473 Resolve_Intrinsic_Unary_Operator (N, Typ);
1482 -- For predefined operators on literals, the operation freezes
1485 if Present (Orig_Type) then
1486 Set_Etype (Act1, Orig_Type);
1487 Freeze_Expression (Act1);
1489 end Make_Call_Into_Operator;
1495 function Operator_Kind
1497 Is_Binary : Boolean) return Node_Kind
1503 if Op_Name = Name_Op_And then
1505 elsif Op_Name = Name_Op_Or then
1507 elsif Op_Name = Name_Op_Xor then
1509 elsif Op_Name = Name_Op_Eq then
1511 elsif Op_Name = Name_Op_Ne then
1513 elsif Op_Name = Name_Op_Lt then
1515 elsif Op_Name = Name_Op_Le then
1517 elsif Op_Name = Name_Op_Gt then
1519 elsif Op_Name = Name_Op_Ge then
1521 elsif Op_Name = Name_Op_Add then
1523 elsif Op_Name = Name_Op_Subtract then
1524 Kind := N_Op_Subtract;
1525 elsif Op_Name = Name_Op_Concat then
1526 Kind := N_Op_Concat;
1527 elsif Op_Name = Name_Op_Multiply then
1528 Kind := N_Op_Multiply;
1529 elsif Op_Name = Name_Op_Divide then
1530 Kind := N_Op_Divide;
1531 elsif Op_Name = Name_Op_Mod then
1533 elsif Op_Name = Name_Op_Rem then
1535 elsif Op_Name = Name_Op_Expon then
1538 raise Program_Error;
1544 if Op_Name = Name_Op_Add then
1546 elsif Op_Name = Name_Op_Subtract then
1548 elsif Op_Name = Name_Op_Abs then
1550 elsif Op_Name = Name_Op_Not then
1553 raise Program_Error;
1560 ----------------------------
1561 -- Preanalyze_And_Resolve --
1562 ----------------------------
1564 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1565 Save_Full_Analysis : constant Boolean := Full_Analysis;
1568 Full_Analysis := False;
1569 Expander_Mode_Save_And_Set (False);
1571 -- We suppress all checks for this analysis, since the checks will
1572 -- be applied properly, and in the right location, when the default
1573 -- expression is reanalyzed and reexpanded later on.
1575 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1577 Expander_Mode_Restore;
1578 Full_Analysis := Save_Full_Analysis;
1579 end Preanalyze_And_Resolve;
1581 -- Version without context type
1583 procedure Preanalyze_And_Resolve (N : Node_Id) is
1584 Save_Full_Analysis : constant Boolean := Full_Analysis;
1587 Full_Analysis := False;
1588 Expander_Mode_Save_And_Set (False);
1591 Resolve (N, Etype (N), Suppress => All_Checks);
1593 Expander_Mode_Restore;
1594 Full_Analysis := Save_Full_Analysis;
1595 end Preanalyze_And_Resolve;
1597 ----------------------------------
1598 -- Replace_Actual_Discriminants --
1599 ----------------------------------
1601 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1602 Loc : constant Source_Ptr := Sloc (N);
1603 Tsk : Node_Id := Empty;
1605 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1611 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1615 if Nkind (Nod) = N_Identifier then
1616 Ent := Entity (Nod);
1619 and then Ekind (Ent) = E_Discriminant
1622 Make_Selected_Component (Loc,
1623 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1624 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1626 Set_Etype (Nod, Etype (Ent));
1634 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1636 -- Start of processing for Replace_Actual_Discriminants
1639 if not Expander_Active then
1643 if Nkind (Name (N)) = N_Selected_Component then
1644 Tsk := Prefix (Name (N));
1646 elsif Nkind (Name (N)) = N_Indexed_Component then
1647 Tsk := Prefix (Prefix (Name (N)));
1653 Replace_Discrs (Default);
1655 end Replace_Actual_Discriminants;
1661 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1662 Ambiguous : Boolean := False;
1663 Ctx_Type : Entity_Id := Typ;
1664 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1665 Err_Type : Entity_Id := Empty;
1666 Found : Boolean := False;
1669 I1 : Interp_Index := 0; -- prevent junk warning
1672 Seen : Entity_Id := Empty; -- prevent junk warning
1674 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1675 -- Determine whether a node comes from a predefined library unit or
1678 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1679 -- Try and fix up a literal so that it matches its expected type. New
1680 -- literals are manufactured if necessary to avoid cascaded errors.
1682 procedure Resolution_Failed;
1683 -- Called when attempt at resolving current expression fails
1685 ------------------------------------
1686 -- Comes_From_Predefined_Lib_Unit --
1687 -------------------------------------
1689 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1692 Sloc (Nod) = Standard_Location
1693 or else Is_Predefined_File_Name (Unit_File_Name (
1694 Get_Source_Unit (Sloc (Nod))));
1695 end Comes_From_Predefined_Lib_Unit;
1697 --------------------
1698 -- Patch_Up_Value --
1699 --------------------
1701 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1703 if Nkind (N) = N_Integer_Literal
1704 and then Is_Real_Type (Typ)
1707 Make_Real_Literal (Sloc (N),
1708 Realval => UR_From_Uint (Intval (N))));
1709 Set_Etype (N, Universal_Real);
1710 Set_Is_Static_Expression (N);
1712 elsif Nkind (N) = N_Real_Literal
1713 and then Is_Integer_Type (Typ)
1716 Make_Integer_Literal (Sloc (N),
1717 Intval => UR_To_Uint (Realval (N))));
1718 Set_Etype (N, Universal_Integer);
1719 Set_Is_Static_Expression (N);
1721 elsif Nkind (N) = N_String_Literal
1722 and then Is_Character_Type (Typ)
1724 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1726 Make_Character_Literal (Sloc (N),
1728 Char_Literal_Value =>
1729 UI_From_Int (Character'Pos ('A'))));
1730 Set_Etype (N, Any_Character);
1731 Set_Is_Static_Expression (N);
1733 elsif Nkind (N) /= N_String_Literal
1734 and then Is_String_Type (Typ)
1737 Make_String_Literal (Sloc (N),
1738 Strval => End_String));
1740 elsif Nkind (N) = N_Range then
1741 Patch_Up_Value (Low_Bound (N), Typ);
1742 Patch_Up_Value (High_Bound (N), Typ);
1746 -----------------------
1747 -- Resolution_Failed --
1748 -----------------------
1750 procedure Resolution_Failed is
1752 Patch_Up_Value (N, Typ);
1754 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1755 Set_Is_Overloaded (N, False);
1757 -- The caller will return without calling the expander, so we need
1758 -- to set the analyzed flag. Note that it is fine to set Analyzed
1759 -- to True even if we are in the middle of a shallow analysis,
1760 -- (see the spec of sem for more details) since this is an error
1761 -- situation anyway, and there is no point in repeating the
1762 -- analysis later (indeed it won't work to repeat it later, since
1763 -- we haven't got a clear resolution of which entity is being
1766 Set_Analyzed (N, True);
1768 end Resolution_Failed;
1770 -- Start of processing for Resolve
1777 -- Access attribute on remote subprogram cannot be used for
1778 -- a non-remote access-to-subprogram type.
1780 if Nkind (N) = N_Attribute_Reference
1781 and then (Attribute_Name (N) = Name_Access
1782 or else Attribute_Name (N) = Name_Unrestricted_Access
1783 or else Attribute_Name (N) = Name_Unchecked_Access)
1784 and then Comes_From_Source (N)
1785 and then Is_Entity_Name (Prefix (N))
1786 and then Is_Subprogram (Entity (Prefix (N)))
1787 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1788 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1791 ("prefix must statically denote a non-remote subprogram", N);
1794 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1796 -- If the context is a Remote_Access_To_Subprogram, access attributes
1797 -- must be resolved with the corresponding fat pointer. There is no need
1798 -- to check for the attribute name since the return type of an
1799 -- attribute is never a remote type.
1801 if Nkind (N) = N_Attribute_Reference
1802 and then Comes_From_Source (N)
1803 and then (Is_Remote_Call_Interface (Typ)
1804 or else Is_Remote_Types (Typ))
1807 Attr : constant Attribute_Id :=
1808 Get_Attribute_Id (Attribute_Name (N));
1809 Pref : constant Node_Id := Prefix (N);
1812 Is_Remote : Boolean := True;
1815 -- Check that Typ is a remote access-to-subprogram type
1817 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1818 -- Prefix (N) must statically denote a remote subprogram
1819 -- declared in a package specification.
1821 if Attr = Attribute_Access then
1822 Decl := Unit_Declaration_Node (Entity (Pref));
1824 if Nkind (Decl) = N_Subprogram_Body then
1825 Spec := Corresponding_Spec (Decl);
1827 if not No (Spec) then
1828 Decl := Unit_Declaration_Node (Spec);
1832 Spec := Parent (Decl);
1834 if not Is_Entity_Name (Prefix (N))
1835 or else Nkind (Spec) /= N_Package_Specification
1837 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1841 ("prefix must statically denote a remote subprogram ",
1846 -- If we are generating code for a distributed program.
1847 -- perform semantic checks against the corresponding
1850 if (Attr = Attribute_Access
1851 or else Attr = Attribute_Unchecked_Access
1852 or else Attr = Attribute_Unrestricted_Access)
1853 and then Expander_Active
1854 and then Get_PCS_Name /= Name_No_DSA
1856 Check_Subtype_Conformant
1857 (New_Id => Entity (Prefix (N)),
1858 Old_Id => Designated_Type
1859 (Corresponding_Remote_Type (Typ)),
1863 Process_Remote_AST_Attribute (N, Typ);
1870 Debug_A_Entry ("resolving ", N);
1872 if Comes_From_Source (N) then
1873 if Is_Fixed_Point_Type (Typ) then
1874 Check_Restriction (No_Fixed_Point, N);
1876 elsif Is_Floating_Point_Type (Typ)
1877 and then Typ /= Universal_Real
1878 and then Typ /= Any_Real
1880 Check_Restriction (No_Floating_Point, N);
1884 -- Return if already analyzed
1886 if Analyzed (N) then
1887 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1890 -- Return if type = Any_Type (previous error encountered)
1892 elsif Etype (N) = Any_Type then
1893 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1897 Check_Parameterless_Call (N);
1899 -- If not overloaded, then we know the type, and all that needs doing
1900 -- is to check that this type is compatible with the context.
1902 if not Is_Overloaded (N) then
1903 Found := Covers (Typ, Etype (N));
1904 Expr_Type := Etype (N);
1906 -- In the overloaded case, we must select the interpretation that
1907 -- is compatible with the context (i.e. the type passed to Resolve)
1910 -- Loop through possible interpretations
1912 Get_First_Interp (N, I, It);
1913 Interp_Loop : while Present (It.Typ) loop
1915 -- We are only interested in interpretations that are compatible
1916 -- with the expected type, any other interpretations are ignored.
1918 if not Covers (Typ, It.Typ) then
1919 if Debug_Flag_V then
1920 Write_Str (" interpretation incompatible with context");
1925 -- Skip the current interpretation if it is disabled by an
1926 -- abstract operator. This action is performed only when the
1927 -- type against which we are resolving is the same as the
1928 -- type of the interpretation.
1930 if Ada_Version >= Ada_05
1931 and then It.Typ = Typ
1932 and then Typ /= Universal_Integer
1933 and then Typ /= Universal_Real
1934 and then Present (It.Abstract_Op)
1939 -- First matching interpretation
1945 Expr_Type := It.Typ;
1947 -- Matching interpretation that is not the first, maybe an
1948 -- error, but there are some cases where preference rules are
1949 -- used to choose between the two possibilities. These and
1950 -- some more obscure cases are handled in Disambiguate.
1953 -- If the current statement is part of a predefined library
1954 -- unit, then all interpretations which come from user level
1955 -- packages should not be considered.
1958 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1963 Error_Msg_Sloc := Sloc (Seen);
1964 It1 := Disambiguate (N, I1, I, Typ);
1966 -- Disambiguation has succeeded. Skip the remaining
1969 if It1 /= No_Interp then
1971 Expr_Type := It1.Typ;
1973 while Present (It.Typ) loop
1974 Get_Next_Interp (I, It);
1978 -- Before we issue an ambiguity complaint, check for
1979 -- the case of a subprogram call where at least one
1980 -- of the arguments is Any_Type, and if so, suppress
1981 -- the message, since it is a cascaded error.
1983 if Nkind_In (N, N_Function_Call,
1984 N_Procedure_Call_Statement)
1991 A := First_Actual (N);
1992 while Present (A) loop
1995 if Nkind (E) = N_Parameter_Association then
1996 E := Explicit_Actual_Parameter (E);
1999 if Etype (E) = Any_Type then
2000 if Debug_Flag_V then
2001 Write_Str ("Any_Type in call");
2012 elsif Nkind (N) in N_Binary_Op
2013 and then (Etype (Left_Opnd (N)) = Any_Type
2014 or else Etype (Right_Opnd (N)) = Any_Type)
2018 elsif Nkind (N) in N_Unary_Op
2019 and then Etype (Right_Opnd (N)) = Any_Type
2024 -- Not that special case, so issue message using the
2025 -- flag Ambiguous to control printing of the header
2026 -- message only at the start of an ambiguous set.
2028 if not Ambiguous then
2029 if Nkind (N) = N_Function_Call
2030 and then Nkind (Name (N)) = N_Explicit_Dereference
2033 ("ambiguous expression "
2034 & "(cannot resolve indirect call)!", N);
2036 Error_Msg_NE -- CODEFIX
2037 ("ambiguous expression (cannot resolve&)!",
2043 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2045 ("\\possible interpretation (inherited)#!", N);
2047 Error_Msg_N -- CODEFIX
2048 ("\\possible interpretation#!", N);
2052 Error_Msg_Sloc := Sloc (It.Nam);
2054 -- By default, the error message refers to the candidate
2055 -- interpretation. But if it is a predefined operator, it
2056 -- is implicitly declared at the declaration of the type
2057 -- of the operand. Recover the sloc of that declaration
2058 -- for the error message.
2060 if Nkind (N) in N_Op
2061 and then Scope (It.Nam) = Standard_Standard
2062 and then not Is_Overloaded (Right_Opnd (N))
2063 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2066 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2068 if Comes_From_Source (Err_Type)
2069 and then Present (Parent (Err_Type))
2071 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2074 elsif Nkind (N) in N_Binary_Op
2075 and then Scope (It.Nam) = Standard_Standard
2076 and then not Is_Overloaded (Left_Opnd (N))
2077 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2080 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2082 if Comes_From_Source (Err_Type)
2083 and then Present (Parent (Err_Type))
2085 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2088 -- If this is an indirect call, use the subprogram_type
2089 -- in the message, to have a meaningful location.
2090 -- Indicate as well if this is an inherited operation,
2091 -- created by a type declaration.
2093 elsif Nkind (N) = N_Function_Call
2094 and then Nkind (Name (N)) = N_Explicit_Dereference
2095 and then Is_Type (It.Nam)
2099 Sloc (Associated_Node_For_Itype (Err_Type));
2104 if Nkind (N) in N_Op
2105 and then Scope (It.Nam) = Standard_Standard
2106 and then Present (Err_Type)
2108 -- Special-case the message for universal_fixed
2109 -- operators, which are not declared with the type
2110 -- of the operand, but appear forever in Standard.
2112 if It.Typ = Universal_Fixed
2113 and then Scope (It.Nam) = Standard_Standard
2116 ("\\possible interpretation as " &
2117 "universal_fixed operation " &
2118 "(RM 4.5.5 (19))", N);
2121 ("\\possible interpretation (predefined)#!", N);
2125 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2128 ("\\possible interpretation (inherited)#!", N);
2130 Error_Msg_N -- CODEFIX
2131 ("\\possible interpretation#!", N);
2137 -- We have a matching interpretation, Expr_Type is the type
2138 -- from this interpretation, and Seen is the entity.
2140 -- For an operator, just set the entity name. The type will be
2141 -- set by the specific operator resolution routine.
2143 if Nkind (N) in N_Op then
2144 Set_Entity (N, Seen);
2145 Generate_Reference (Seen, N);
2147 elsif Nkind (N) = N_Character_Literal then
2148 Set_Etype (N, Expr_Type);
2150 -- For an explicit dereference, attribute reference, range,
2151 -- short-circuit form (which is not an operator node), or call
2152 -- with a name that is an explicit dereference, there is
2153 -- nothing to be done at this point.
2155 elsif Nkind_In (N, N_Explicit_Dereference,
2156 N_Attribute_Reference,
2158 N_Indexed_Component,
2161 N_Selected_Component,
2163 or else Nkind (Name (N)) = N_Explicit_Dereference
2167 -- For procedure or function calls, set the type of the name,
2168 -- and also the entity pointer for the prefix
2170 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2171 and then (Is_Entity_Name (Name (N))
2172 or else Nkind (Name (N)) = N_Operator_Symbol)
2174 Set_Etype (Name (N), Expr_Type);
2175 Set_Entity (Name (N), Seen);
2176 Generate_Reference (Seen, Name (N));
2178 elsif Nkind (N) = N_Function_Call
2179 and then Nkind (Name (N)) = N_Selected_Component
2181 Set_Etype (Name (N), Expr_Type);
2182 Set_Entity (Selector_Name (Name (N)), Seen);
2183 Generate_Reference (Seen, Selector_Name (Name (N)));
2185 -- For all other cases, just set the type of the Name
2188 Set_Etype (Name (N), Expr_Type);
2195 -- Move to next interpretation
2197 exit Interp_Loop when No (It.Typ);
2199 Get_Next_Interp (I, It);
2200 end loop Interp_Loop;
2203 -- At this stage Found indicates whether or not an acceptable
2204 -- interpretation exists. If not, then we have an error, except
2205 -- that if the context is Any_Type as a result of some other error,
2206 -- then we suppress the error report.
2209 if Typ /= Any_Type then
2211 -- If type we are looking for is Void, then this is the procedure
2212 -- call case, and the error is simply that what we gave is not a
2213 -- procedure name (we think of procedure calls as expressions with
2214 -- types internally, but the user doesn't think of them this way!)
2216 if Typ = Standard_Void_Type then
2218 -- Special case message if function used as a procedure
2220 if Nkind (N) = N_Procedure_Call_Statement
2221 and then Is_Entity_Name (Name (N))
2222 and then Ekind (Entity (Name (N))) = E_Function
2225 ("cannot use function & in a procedure call",
2226 Name (N), Entity (Name (N)));
2228 -- Otherwise give general message (not clear what cases this
2229 -- covers, but no harm in providing for them!)
2232 Error_Msg_N ("expect procedure name in procedure call", N);
2237 -- Otherwise we do have a subexpression with the wrong type
2239 -- Check for the case of an allocator which uses an access type
2240 -- instead of the designated type. This is a common error and we
2241 -- specialize the message, posting an error on the operand of the
2242 -- allocator, complaining that we expected the designated type of
2245 elsif Nkind (N) = N_Allocator
2246 and then Ekind (Typ) in Access_Kind
2247 and then Ekind (Etype (N)) in Access_Kind
2248 and then Designated_Type (Etype (N)) = Typ
2250 Wrong_Type (Expression (N), Designated_Type (Typ));
2253 -- Check for view mismatch on Null in instances, for which the
2254 -- view-swapping mechanism has no identifier.
2256 elsif (In_Instance or else In_Inlined_Body)
2257 and then (Nkind (N) = N_Null)
2258 and then Is_Private_Type (Typ)
2259 and then Is_Access_Type (Full_View (Typ))
2261 Resolve (N, Full_View (Typ));
2265 -- Check for an aggregate. Sometimes we can get bogus aggregates
2266 -- from misuse of parentheses, and we are about to complain about
2267 -- the aggregate without even looking inside it.
2269 -- Instead, if we have an aggregate of type Any_Composite, then
2270 -- analyze and resolve the component fields, and then only issue
2271 -- another message if we get no errors doing this (otherwise
2272 -- assume that the errors in the aggregate caused the problem).
2274 elsif Nkind (N) = N_Aggregate
2275 and then Etype (N) = Any_Composite
2277 -- Disable expansion in any case. If there is a type mismatch
2278 -- it may be fatal to try to expand the aggregate. The flag
2279 -- would otherwise be set to false when the error is posted.
2281 Expander_Active := False;
2284 procedure Check_Aggr (Aggr : Node_Id);
2285 -- Check one aggregate, and set Found to True if we have a
2286 -- definite error in any of its elements
2288 procedure Check_Elmt (Aelmt : Node_Id);
2289 -- Check one element of aggregate and set Found to True if
2290 -- we definitely have an error in the element.
2296 procedure Check_Aggr (Aggr : Node_Id) is
2300 if Present (Expressions (Aggr)) then
2301 Elmt := First (Expressions (Aggr));
2302 while Present (Elmt) loop
2308 if Present (Component_Associations (Aggr)) then
2309 Elmt := First (Component_Associations (Aggr));
2310 while Present (Elmt) loop
2312 -- If this is a default-initialized component, then
2313 -- there is nothing to check. The box will be
2314 -- replaced by the appropriate call during late
2317 if not Box_Present (Elmt) then
2318 Check_Elmt (Expression (Elmt));
2330 procedure Check_Elmt (Aelmt : Node_Id) is
2332 -- If we have a nested aggregate, go inside it (to
2333 -- attempt a naked analyze-resolve of the aggregate
2334 -- can cause undesirable cascaded errors). Do not
2335 -- resolve expression if it needs a type from context,
2336 -- as for integer * fixed expression.
2338 if Nkind (Aelmt) = N_Aggregate then
2344 if not Is_Overloaded (Aelmt)
2345 and then Etype (Aelmt) /= Any_Fixed
2350 if Etype (Aelmt) = Any_Type then
2361 -- If an error message was issued already, Found got reset
2362 -- to True, so if it is still False, issue the standard
2363 -- Wrong_Type message.
2366 if Is_Overloaded (N)
2367 and then Nkind (N) = N_Function_Call
2370 Subp_Name : Node_Id;
2372 if Is_Entity_Name (Name (N)) then
2373 Subp_Name := Name (N);
2375 elsif Nkind (Name (N)) = N_Selected_Component then
2377 -- Protected operation: retrieve operation name
2379 Subp_Name := Selector_Name (Name (N));
2381 raise Program_Error;
2384 Error_Msg_Node_2 := Typ;
2385 Error_Msg_NE ("no visible interpretation of&" &
2386 " matches expected type&", N, Subp_Name);
2389 if All_Errors_Mode then
2391 Index : Interp_Index;
2395 Error_Msg_N ("\\possible interpretations:", N);
2397 Get_First_Interp (Name (N), Index, It);
2398 while Present (It.Nam) loop
2399 Error_Msg_Sloc := Sloc (It.Nam);
2400 Error_Msg_Node_2 := It.Nam;
2402 ("\\ type& for & declared#", N, It.Typ);
2403 Get_Next_Interp (Index, It);
2408 Error_Msg_N ("\use -gnatf for details", N);
2411 Wrong_Type (N, Typ);
2419 -- Test if we have more than one interpretation for the context
2421 elsif Ambiguous then
2425 -- Here we have an acceptable interpretation for the context
2428 -- Propagate type information and normalize tree for various
2429 -- predefined operations. If the context only imposes a class of
2430 -- types, rather than a specific type, propagate the actual type
2433 if Typ = Any_Integer
2434 or else Typ = Any_Boolean
2435 or else Typ = Any_Modular
2436 or else Typ = Any_Real
2437 or else Typ = Any_Discrete
2439 Ctx_Type := Expr_Type;
2441 -- Any_Fixed is legal in a real context only if a specific
2442 -- fixed point type is imposed. If Norman Cohen can be
2443 -- confused by this, it deserves a separate message.
2446 and then Expr_Type = Any_Fixed
2448 Error_Msg_N ("illegal context for mixed mode operation", N);
2449 Set_Etype (N, Universal_Real);
2450 Ctx_Type := Universal_Real;
2454 -- A user-defined operator is transformed into a function call at
2455 -- this point, so that further processing knows that operators are
2456 -- really operators (i.e. are predefined operators). User-defined
2457 -- operators that are intrinsic are just renamings of the predefined
2458 -- ones, and need not be turned into calls either, but if they rename
2459 -- a different operator, we must transform the node accordingly.
2460 -- Instantiations of Unchecked_Conversion are intrinsic but are
2461 -- treated as functions, even if given an operator designator.
2463 if Nkind (N) in N_Op
2464 and then Present (Entity (N))
2465 and then Ekind (Entity (N)) /= E_Operator
2468 if not Is_Predefined_Op (Entity (N)) then
2469 Rewrite_Operator_As_Call (N, Entity (N));
2471 elsif Present (Alias (Entity (N)))
2473 Nkind (Parent (Parent (Entity (N)))) =
2474 N_Subprogram_Renaming_Declaration
2476 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2478 -- If the node is rewritten, it will be fully resolved in
2479 -- Rewrite_Renamed_Operator.
2481 if Analyzed (N) then
2487 case N_Subexpr'(Nkind (N)) is
2489 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2491 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2493 when N_And_Then | N_Or_Else
2494 => Resolve_Short_Circuit (N, Ctx_Type);
2496 when N_Attribute_Reference
2497 => Resolve_Attribute (N, Ctx_Type);
2499 when N_Character_Literal
2500 => Resolve_Character_Literal (N, Ctx_Type);
2502 when N_Conditional_Expression
2503 => Resolve_Conditional_Expression (N, Ctx_Type);
2505 when N_Expanded_Name
2506 => Resolve_Entity_Name (N, Ctx_Type);
2508 when N_Extension_Aggregate
2509 => Resolve_Extension_Aggregate (N, Ctx_Type);
2511 when N_Explicit_Dereference
2512 => Resolve_Explicit_Dereference (N, Ctx_Type);
2514 when N_Function_Call
2515 => Resolve_Call (N, Ctx_Type);
2518 => Resolve_Entity_Name (N, Ctx_Type);
2520 when N_Indexed_Component
2521 => Resolve_Indexed_Component (N, Ctx_Type);
2523 when N_Integer_Literal
2524 => Resolve_Integer_Literal (N, Ctx_Type);
2526 when N_Membership_Test
2527 => Resolve_Membership_Op (N, Ctx_Type);
2529 when N_Null => Resolve_Null (N, Ctx_Type);
2531 when N_Op_And | N_Op_Or | N_Op_Xor
2532 => Resolve_Logical_Op (N, Ctx_Type);
2534 when N_Op_Eq | N_Op_Ne
2535 => Resolve_Equality_Op (N, Ctx_Type);
2537 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2538 => Resolve_Comparison_Op (N, Ctx_Type);
2540 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2542 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2543 N_Op_Divide | N_Op_Mod | N_Op_Rem
2545 => Resolve_Arithmetic_Op (N, Ctx_Type);
2547 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2549 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2551 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2552 => Resolve_Unary_Op (N, Ctx_Type);
2554 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2556 when N_Procedure_Call_Statement
2557 => Resolve_Call (N, Ctx_Type);
2559 when N_Operator_Symbol
2560 => Resolve_Operator_Symbol (N, Ctx_Type);
2562 when N_Qualified_Expression
2563 => Resolve_Qualified_Expression (N, Ctx_Type);
2565 when N_Raise_xxx_Error
2566 => Set_Etype (N, Ctx_Type);
2568 when N_Range => Resolve_Range (N, Ctx_Type);
2571 => Resolve_Real_Literal (N, Ctx_Type);
2573 when N_Reference => Resolve_Reference (N, Ctx_Type);
2575 when N_Selected_Component
2576 => Resolve_Selected_Component (N, Ctx_Type);
2578 when N_Slice => Resolve_Slice (N, Ctx_Type);
2580 when N_String_Literal
2581 => Resolve_String_Literal (N, Ctx_Type);
2583 when N_Subprogram_Info
2584 => Resolve_Subprogram_Info (N, Ctx_Type);
2586 when N_Type_Conversion
2587 => Resolve_Type_Conversion (N, Ctx_Type);
2589 when N_Unchecked_Expression =>
2590 Resolve_Unchecked_Expression (N, Ctx_Type);
2592 when N_Unchecked_Type_Conversion =>
2593 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2597 -- If the subexpression was replaced by a non-subexpression, then
2598 -- all we do is to expand it. The only legitimate case we know of
2599 -- is converting procedure call statement to entry call statements,
2600 -- but there may be others, so we are making this test general.
2602 if Nkind (N) not in N_Subexpr then
2603 Debug_A_Exit ("resolving ", N, " (done)");
2608 -- The expression is definitely NOT overloaded at this point, so
2609 -- we reset the Is_Overloaded flag to avoid any confusion when
2610 -- reanalyzing the node.
2612 Set_Is_Overloaded (N, False);
2614 -- Freeze expression type, entity if it is a name, and designated
2615 -- type if it is an allocator (RM 13.14(10,11,13)).
2617 -- Now that the resolution of the type of the node is complete,
2618 -- and we did not detect an error, we can expand this node. We
2619 -- skip the expand call if we are in a default expression, see
2620 -- section "Handling of Default Expressions" in Sem spec.
2622 Debug_A_Exit ("resolving ", N, " (done)");
2624 -- We unconditionally freeze the expression, even if we are in
2625 -- default expression mode (the Freeze_Expression routine tests
2626 -- this flag and only freezes static types if it is set).
2628 Freeze_Expression (N);
2630 -- Now we can do the expansion
2640 -- Version with check(s) suppressed
2642 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2644 if Suppress = All_Checks then
2646 Svg : constant Suppress_Array := Scope_Suppress;
2648 Scope_Suppress := (others => True);
2650 Scope_Suppress := Svg;
2655 Svg : constant Boolean := Scope_Suppress (Suppress);
2657 Scope_Suppress (Suppress) := True;
2659 Scope_Suppress (Suppress) := Svg;
2668 -- Version with implicit type
2670 procedure Resolve (N : Node_Id) is
2672 Resolve (N, Etype (N));
2675 ---------------------
2676 -- Resolve_Actuals --
2677 ---------------------
2679 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2680 Loc : constant Source_Ptr := Sloc (N);
2685 Prev : Node_Id := Empty;
2688 procedure Check_Argument_Order;
2689 -- Performs a check for the case where the actuals are all simple
2690 -- identifiers that correspond to the formal names, but in the wrong
2691 -- order, which is considered suspicious and cause for a warning.
2693 procedure Check_Prefixed_Call;
2694 -- If the original node is an overloaded call in prefix notation,
2695 -- insert an 'Access or a dereference as needed over the first actual.
2696 -- Try_Object_Operation has already verified that there is a valid
2697 -- interpretation, but the form of the actual can only be determined
2698 -- once the primitive operation is identified.
2700 procedure Insert_Default;
2701 -- If the actual is missing in a call, insert in the actuals list
2702 -- an instance of the default expression. The insertion is always
2703 -- a named association.
2705 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2706 -- Check whether T1 and T2, or their full views, are derived from a
2707 -- common type. Used to enforce the restrictions on array conversions
2710 function Static_Concatenation (N : Node_Id) return Boolean;
2711 -- Predicate to determine whether an actual that is a concatenation
2712 -- will be evaluated statically and does not need a transient scope.
2713 -- This must be determined before the actual is resolved and expanded
2714 -- because if needed the transient scope must be introduced earlier.
2716 --------------------------
2717 -- Check_Argument_Order --
2718 --------------------------
2720 procedure Check_Argument_Order is
2722 -- Nothing to do if no parameters, or original node is neither a
2723 -- function call nor a procedure call statement (happens in the
2724 -- operator-transformed-to-function call case), or the call does
2725 -- not come from source, or this warning is off.
2727 if not Warn_On_Parameter_Order
2729 No (Parameter_Associations (N))
2731 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2734 not Comes_From_Source (N)
2740 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2743 -- Nothing to do if only one parameter
2749 -- Here if at least two arguments
2752 Actuals : array (1 .. Nargs) of Node_Id;
2756 Wrong_Order : Boolean := False;
2757 -- Set True if an out of order case is found
2760 -- Collect identifier names of actuals, fail if any actual is
2761 -- not a simple identifier, and record max length of name.
2763 Actual := First (Parameter_Associations (N));
2764 for J in Actuals'Range loop
2765 if Nkind (Actual) /= N_Identifier then
2768 Actuals (J) := Actual;
2773 -- If we got this far, all actuals are identifiers and the list
2774 -- of their names is stored in the Actuals array.
2776 Formal := First_Formal (Nam);
2777 for J in Actuals'Range loop
2779 -- If we ran out of formals, that's odd, probably an error
2780 -- which will be detected elsewhere, but abandon the search.
2786 -- If name matches and is in order OK
2788 if Chars (Formal) = Chars (Actuals (J)) then
2792 -- If no match, see if it is elsewhere in list and if so
2793 -- flag potential wrong order if type is compatible.
2795 for K in Actuals'Range loop
2796 if Chars (Formal) = Chars (Actuals (K))
2798 Has_Compatible_Type (Actuals (K), Etype (Formal))
2800 Wrong_Order := True;
2810 <<Continue>> Next_Formal (Formal);
2813 -- If Formals left over, also probably an error, skip warning
2815 if Present (Formal) then
2819 -- Here we give the warning if something was out of order
2823 ("actuals for this call may be in wrong order?", N);
2827 end Check_Argument_Order;
2829 -------------------------
2830 -- Check_Prefixed_Call --
2831 -------------------------
2833 procedure Check_Prefixed_Call is
2834 Act : constant Node_Id := First_Actual (N);
2835 A_Type : constant Entity_Id := Etype (Act);
2836 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2837 Orig : constant Node_Id := Original_Node (N);
2841 -- Check whether the call is a prefixed call, with or without
2842 -- additional actuals.
2844 if Nkind (Orig) = N_Selected_Component
2846 (Nkind (Orig) = N_Indexed_Component
2847 and then Nkind (Prefix (Orig)) = N_Selected_Component
2848 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2849 and then Is_Entity_Name (Act)
2850 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2852 if Is_Access_Type (A_Type)
2853 and then not Is_Access_Type (F_Type)
2855 -- Introduce dereference on object in prefix
2858 Make_Explicit_Dereference (Sloc (Act),
2859 Prefix => Relocate_Node (Act));
2860 Rewrite (Act, New_A);
2863 elsif Is_Access_Type (F_Type)
2864 and then not Is_Access_Type (A_Type)
2866 -- Introduce an implicit 'Access in prefix
2868 if not Is_Aliased_View (Act) then
2870 ("object in prefixed call to& must be aliased"
2871 & " (RM-2005 4.3.1 (13))",
2876 Make_Attribute_Reference (Loc,
2877 Attribute_Name => Name_Access,
2878 Prefix => Relocate_Node (Act)));
2883 end Check_Prefixed_Call;
2885 --------------------
2886 -- Insert_Default --
2887 --------------------
2889 procedure Insert_Default is
2894 -- Missing argument in call, nothing to insert
2896 if No (Default_Value (F)) then
2900 -- Note that we do a full New_Copy_Tree, so that any associated
2901 -- Itypes are properly copied. This may not be needed any more,
2902 -- but it does no harm as a safety measure! Defaults of a generic
2903 -- formal may be out of bounds of the corresponding actual (see
2904 -- cc1311b) and an additional check may be required.
2909 New_Scope => Current_Scope,
2912 if Is_Concurrent_Type (Scope (Nam))
2913 and then Has_Discriminants (Scope (Nam))
2915 Replace_Actual_Discriminants (N, Actval);
2918 if Is_Overloadable (Nam)
2919 and then Present (Alias (Nam))
2921 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2922 and then not Is_Tagged_Type (Etype (F))
2924 -- If default is a real literal, do not introduce a
2925 -- conversion whose effect may depend on the run-time
2926 -- size of universal real.
2928 if Nkind (Actval) = N_Real_Literal then
2929 Set_Etype (Actval, Base_Type (Etype (F)));
2931 Actval := Unchecked_Convert_To (Etype (F), Actval);
2935 if Is_Scalar_Type (Etype (F)) then
2936 Enable_Range_Check (Actval);
2939 Set_Parent (Actval, N);
2941 -- Resolve aggregates with their base type, to avoid scope
2942 -- anomalies: the subtype was first built in the subprogram
2943 -- declaration, and the current call may be nested.
2945 if Nkind (Actval) = N_Aggregate
2946 and then Has_Discriminants (Etype (Actval))
2948 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2950 Analyze_And_Resolve (Actval, Etype (Actval));
2954 Set_Parent (Actval, N);
2956 -- See note above concerning aggregates
2958 if Nkind (Actval) = N_Aggregate
2959 and then Has_Discriminants (Etype (Actval))
2961 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2963 -- Resolve entities with their own type, which may differ
2964 -- from the type of a reference in a generic context (the
2965 -- view swapping mechanism did not anticipate the re-analysis
2966 -- of default values in calls).
2968 elsif Is_Entity_Name (Actval) then
2969 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2972 Analyze_And_Resolve (Actval, Etype (Actval));
2976 -- If default is a tag indeterminate function call, propagate
2977 -- tag to obtain proper dispatching.
2979 if Is_Controlling_Formal (F)
2980 and then Nkind (Default_Value (F)) = N_Function_Call
2982 Set_Is_Controlling_Actual (Actval);
2987 -- If the default expression raises constraint error, then just
2988 -- silently replace it with an N_Raise_Constraint_Error node,
2989 -- since we already gave the warning on the subprogram spec.
2991 if Raises_Constraint_Error (Actval) then
2993 Make_Raise_Constraint_Error (Loc,
2994 Reason => CE_Range_Check_Failed));
2995 Set_Raises_Constraint_Error (Actval);
2996 Set_Etype (Actval, Etype (F));
3000 Make_Parameter_Association (Loc,
3001 Explicit_Actual_Parameter => Actval,
3002 Selector_Name => Make_Identifier (Loc, Chars (F)));
3004 -- Case of insertion is first named actual
3006 if No (Prev) or else
3007 Nkind (Parent (Prev)) /= N_Parameter_Association
3009 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3010 Set_First_Named_Actual (N, Actval);
3013 if No (Parameter_Associations (N)) then
3014 Set_Parameter_Associations (N, New_List (Assoc));
3016 Append (Assoc, Parameter_Associations (N));
3020 Insert_After (Prev, Assoc);
3023 -- Case of insertion is not first named actual
3026 Set_Next_Named_Actual
3027 (Assoc, Next_Named_Actual (Parent (Prev)));
3028 Set_Next_Named_Actual (Parent (Prev), Actval);
3029 Append (Assoc, Parameter_Associations (N));
3032 Mark_Rewrite_Insertion (Assoc);
3033 Mark_Rewrite_Insertion (Actval);
3042 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3043 FT1 : Entity_Id := T1;
3044 FT2 : Entity_Id := T2;
3047 if Is_Private_Type (T1)
3048 and then Present (Full_View (T1))
3050 FT1 := Full_View (T1);
3053 if Is_Private_Type (T2)
3054 and then Present (Full_View (T2))
3056 FT2 := Full_View (T2);
3059 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3062 --------------------------
3063 -- Static_Concatenation --
3064 --------------------------
3066 function Static_Concatenation (N : Node_Id) return Boolean is
3069 when N_String_Literal =>
3074 -- Concatenation is static when both operands are static
3075 -- and the concatenation operator is a predefined one.
3077 return Scope (Entity (N)) = Standard_Standard
3079 Static_Concatenation (Left_Opnd (N))
3081 Static_Concatenation (Right_Opnd (N));
3084 if Is_Entity_Name (N) then
3086 Ent : constant Entity_Id := Entity (N);
3088 return Ekind (Ent) = E_Constant
3089 and then Present (Constant_Value (Ent))
3091 Is_Static_Expression (Constant_Value (Ent));
3098 end Static_Concatenation;
3100 -- Start of processing for Resolve_Actuals
3103 Check_Argument_Order;
3105 if Present (First_Actual (N)) then
3106 Check_Prefixed_Call;
3109 A := First_Actual (N);
3110 F := First_Formal (Nam);
3111 while Present (F) loop
3112 if No (A) and then Needs_No_Actuals (Nam) then
3115 -- If we have an error in any actual or formal, indicated by a type
3116 -- of Any_Type, then abandon resolution attempt, and set result type
3119 elsif (Present (A) and then Etype (A) = Any_Type)
3120 or else Etype (F) = Any_Type
3122 Set_Etype (N, Any_Type);
3126 -- Case where actual is present
3128 -- If the actual is an entity, generate a reference to it now. We
3129 -- do this before the actual is resolved, because a formal of some
3130 -- protected subprogram, or a task discriminant, will be rewritten
3131 -- during expansion, and the reference to the source entity may
3135 and then Is_Entity_Name (A)
3136 and then Comes_From_Source (N)
3138 Orig_A := Entity (A);
3140 if Present (Orig_A) then
3141 if Is_Formal (Orig_A)
3142 and then Ekind (F) /= E_In_Parameter
3144 Generate_Reference (Orig_A, A, 'm');
3145 elsif not Is_Overloaded (A) then
3146 Generate_Reference (Orig_A, A);
3152 and then (Nkind (Parent (A)) /= N_Parameter_Association
3154 Chars (Selector_Name (Parent (A))) = Chars (F))
3156 -- If style checking mode on, check match of formal name
3159 if Nkind (Parent (A)) = N_Parameter_Association then
3160 Check_Identifier (Selector_Name (Parent (A)), F);
3164 -- If the formal is Out or In_Out, do not resolve and expand the
3165 -- conversion, because it is subsequently expanded into explicit
3166 -- temporaries and assignments. However, the object of the
3167 -- conversion can be resolved. An exception is the case of tagged
3168 -- type conversion with a class-wide actual. In that case we want
3169 -- the tag check to occur and no temporary will be needed (no
3170 -- representation change can occur) and the parameter is passed by
3171 -- reference, so we go ahead and resolve the type conversion.
3172 -- Another exception is the case of reference to component or
3173 -- subcomponent of a bit-packed array, in which case we want to
3174 -- defer expansion to the point the in and out assignments are
3177 if Ekind (F) /= E_In_Parameter
3178 and then Nkind (A) = N_Type_Conversion
3179 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3181 if Ekind (F) = E_In_Out_Parameter
3182 and then Is_Array_Type (Etype (F))
3184 if Has_Aliased_Components (Etype (Expression (A)))
3185 /= Has_Aliased_Components (Etype (F))
3188 -- In a view conversion, the conversion must be legal in
3189 -- both directions, and thus both component types must be
3190 -- aliased, or neither (4.6 (8)).
3192 -- The additional rule 4.6 (24.9.2) seems unduly
3193 -- restrictive: the privacy requirement should not apply
3194 -- to generic types, and should be checked in an
3195 -- instance. ARG query is in order ???
3198 ("both component types in a view conversion must be"
3199 & " aliased, or neither", A);
3202 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3204 if Is_By_Reference_Type (Etype (F))
3205 or else Is_By_Reference_Type (Etype (Expression (A)))
3208 ("view conversion between unrelated by reference " &
3209 "array types not allowed (\'A'I-00246)", A);
3212 Comp_Type : constant Entity_Id :=
3214 (Etype (Expression (A)));
3216 if Comes_From_Source (A)
3217 and then Ada_Version >= Ada_05
3219 ((Is_Private_Type (Comp_Type)
3220 and then not Is_Generic_Type (Comp_Type))
3221 or else Is_Tagged_Type (Comp_Type)
3222 or else Is_Volatile (Comp_Type))
3225 ("component type of a view conversion cannot"
3226 & " be private, tagged, or volatile"
3235 if (Conversion_OK (A)
3236 or else Valid_Conversion (A, Etype (A), Expression (A)))
3237 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3239 Resolve (Expression (A));
3242 -- If the actual is a function call that returns a limited
3243 -- unconstrained object that needs finalization, create a
3244 -- transient scope for it, so that it can receive the proper
3245 -- finalization list.
3247 elsif Nkind (A) = N_Function_Call
3248 and then Is_Limited_Record (Etype (F))
3249 and then not Is_Constrained (Etype (F))
3250 and then Expander_Active
3252 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3254 Establish_Transient_Scope (A, False);
3256 -- A small optimization: if one of the actuals is a concatenation
3257 -- create a block around a procedure call to recover stack space.
3258 -- This alleviates stack usage when several procedure calls in
3259 -- the same statement list use concatenation. We do not perform
3260 -- this wrapping for code statements, where the argument is a
3261 -- static string, and we want to preserve warnings involving
3262 -- sequences of such statements.
3264 elsif Nkind (A) = N_Op_Concat
3265 and then Nkind (N) = N_Procedure_Call_Statement
3266 and then Expander_Active
3268 not (Is_Intrinsic_Subprogram (Nam)
3269 and then Chars (Nam) = Name_Asm)
3270 and then not Static_Concatenation (A)
3272 Establish_Transient_Scope (A, False);
3273 Resolve (A, Etype (F));
3276 if Nkind (A) = N_Type_Conversion
3277 and then Is_Array_Type (Etype (F))
3278 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3280 (Is_Limited_Type (Etype (F))
3281 or else Is_Limited_Type (Etype (Expression (A))))
3284 ("conversion between unrelated limited array types " &
3285 "not allowed (\A\I-00246)", A);
3287 if Is_Limited_Type (Etype (F)) then
3288 Explain_Limited_Type (Etype (F), A);
3291 if Is_Limited_Type (Etype (Expression (A))) then
3292 Explain_Limited_Type (Etype (Expression (A)), A);
3296 -- (Ada 2005: AI-251): If the actual is an allocator whose
3297 -- directly designated type is a class-wide interface, we build
3298 -- an anonymous access type to use it as the type of the
3299 -- allocator. Later, when the subprogram call is expanded, if
3300 -- the interface has a secondary dispatch table the expander
3301 -- will add a type conversion to force the correct displacement
3304 if Nkind (A) = N_Allocator then
3306 DDT : constant Entity_Id :=
3307 Directly_Designated_Type (Base_Type (Etype (F)));
3309 New_Itype : Entity_Id;
3312 if Is_Class_Wide_Type (DDT)
3313 and then Is_Interface (DDT)
3315 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3316 Set_Etype (New_Itype, Etype (A));
3317 Set_Directly_Designated_Type (New_Itype,
3318 Directly_Designated_Type (Etype (A)));
3319 Set_Etype (A, New_Itype);
3322 -- Ada 2005, AI-162:If the actual is an allocator, the
3323 -- innermost enclosing statement is the master of the
3324 -- created object. This needs to be done with expansion
3325 -- enabled only, otherwise the transient scope will not
3326 -- be removed in the expansion of the wrapped construct.
3328 if (Is_Controlled (DDT) or else Has_Task (DDT))
3329 and then Expander_Active
3331 Establish_Transient_Scope (A, False);
3336 -- (Ada 2005): The call may be to a primitive operation of
3337 -- a tagged synchronized type, declared outside of the type.
3338 -- In this case the controlling actual must be converted to
3339 -- its corresponding record type, which is the formal type.
3340 -- The actual may be a subtype, either because of a constraint
3341 -- or because it is a generic actual, so use base type to
3342 -- locate concurrent type.
3344 A_Typ := Base_Type (Etype (A));
3345 F_Typ := Base_Type (Etype (F));
3348 Full_A_Typ : Entity_Id;
3351 if Present (Full_View (A_Typ)) then
3352 Full_A_Typ := Base_Type (Full_View (A_Typ));
3354 Full_A_Typ := A_Typ;
3357 -- Tagged synchronized type (case 1): the actual is a
3360 if Is_Concurrent_Type (A_Typ)
3361 and then Corresponding_Record_Type (A_Typ) = F_Typ
3364 Unchecked_Convert_To
3365 (Corresponding_Record_Type (A_Typ), A));
3366 Resolve (A, Etype (F));
3368 -- Tagged synchronized type (case 2): the formal is a
3371 elsif Ekind (Full_A_Typ) = E_Record_Type
3373 (Corresponding_Concurrent_Type (Full_A_Typ))
3374 and then Is_Concurrent_Type (F_Typ)
3375 and then Present (Corresponding_Record_Type (F_Typ))
3376 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3378 Resolve (A, Corresponding_Record_Type (F_Typ));
3383 Resolve (A, Etype (F));
3391 -- For mode IN, if actual is an entity, and the type of the formal
3392 -- has warnings suppressed, then we reset Never_Set_In_Source for
3393 -- the calling entity. The reason for this is to catch cases like
3394 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3395 -- uses trickery to modify an IN parameter.
3397 if Ekind (F) = E_In_Parameter
3398 and then Is_Entity_Name (A)
3399 and then Present (Entity (A))
3400 and then Ekind (Entity (A)) = E_Variable
3401 and then Has_Warnings_Off (F_Typ)
3403 Set_Never_Set_In_Source (Entity (A), False);
3406 -- Perform error checks for IN and IN OUT parameters
3408 if Ekind (F) /= E_Out_Parameter then
3410 -- Check unset reference. For scalar parameters, it is clearly
3411 -- wrong to pass an uninitialized value as either an IN or
3412 -- IN-OUT parameter. For composites, it is also clearly an
3413 -- error to pass a completely uninitialized value as an IN
3414 -- parameter, but the case of IN OUT is trickier. We prefer
3415 -- not to give a warning here. For example, suppose there is
3416 -- a routine that sets some component of a record to False.
3417 -- It is perfectly reasonable to make this IN-OUT and allow
3418 -- either initialized or uninitialized records to be passed
3421 -- For partially initialized composite values, we also avoid
3422 -- warnings, since it is quite likely that we are passing a
3423 -- partially initialized value and only the initialized fields
3424 -- will in fact be read in the subprogram.
3426 if Is_Scalar_Type (A_Typ)
3427 or else (Ekind (F) = E_In_Parameter
3428 and then not Is_Partially_Initialized_Type (A_Typ))
3430 Check_Unset_Reference (A);
3433 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3434 -- actual to a nested call, since this is case of reading an
3435 -- out parameter, which is not allowed.
3437 if Ada_Version = Ada_83
3438 and then Is_Entity_Name (A)
3439 and then Ekind (Entity (A)) = E_Out_Parameter
3441 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3445 -- Case of OUT or IN OUT parameter
3447 if Ekind (F) /= E_In_Parameter then
3449 -- For an Out parameter, check for useless assignment. Note
3450 -- that we can't set Last_Assignment this early, because we may
3451 -- kill current values in Resolve_Call, and that call would
3452 -- clobber the Last_Assignment field.
3454 -- Note: call Warn_On_Useless_Assignment before doing the check
3455 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3456 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3457 -- reflects the last assignment, not this one!
3459 if Ekind (F) = E_Out_Parameter then
3460 if Warn_On_Modified_As_Out_Parameter (F)
3461 and then Is_Entity_Name (A)
3462 and then Present (Entity (A))
3463 and then Comes_From_Source (N)
3465 Warn_On_Useless_Assignment (Entity (A), A);
3469 -- Validate the form of the actual. Note that the call to
3470 -- Is_OK_Variable_For_Out_Formal generates the required
3471 -- reference in this case.
3473 if not Is_OK_Variable_For_Out_Formal (A) then
3474 Error_Msg_NE ("actual for& must be a variable", A, F);
3477 -- What's the following about???
3479 if Is_Entity_Name (A) then
3480 Kill_Checks (Entity (A));
3486 if Etype (A) = Any_Type then
3487 Set_Etype (N, Any_Type);
3491 -- Apply appropriate range checks for in, out, and in-out
3492 -- parameters. Out and in-out parameters also need a separate
3493 -- check, if there is a type conversion, to make sure the return
3494 -- value meets the constraints of the variable before the
3497 -- Gigi looks at the check flag and uses the appropriate types.
3498 -- For now since one flag is used there is an optimization which
3499 -- might not be done in the In Out case since Gigi does not do
3500 -- any analysis. More thought required about this ???
3502 if Ekind (F) = E_In_Parameter
3503 or else Ekind (F) = E_In_Out_Parameter
3505 if Is_Scalar_Type (Etype (A)) then
3506 Apply_Scalar_Range_Check (A, F_Typ);
3508 elsif Is_Array_Type (Etype (A)) then
3509 Apply_Length_Check (A, F_Typ);
3511 elsif Is_Record_Type (F_Typ)
3512 and then Has_Discriminants (F_Typ)
3513 and then Is_Constrained (F_Typ)
3514 and then (not Is_Derived_Type (F_Typ)
3515 or else Comes_From_Source (Nam))
3517 Apply_Discriminant_Check (A, F_Typ);
3519 elsif Is_Access_Type (F_Typ)
3520 and then Is_Array_Type (Designated_Type (F_Typ))
3521 and then Is_Constrained (Designated_Type (F_Typ))
3523 Apply_Length_Check (A, F_Typ);
3525 elsif Is_Access_Type (F_Typ)
3526 and then Has_Discriminants (Designated_Type (F_Typ))
3527 and then Is_Constrained (Designated_Type (F_Typ))
3529 Apply_Discriminant_Check (A, F_Typ);
3532 Apply_Range_Check (A, F_Typ);
3535 -- Ada 2005 (AI-231)
3537 if Ada_Version >= Ada_05
3538 and then Is_Access_Type (F_Typ)
3539 and then Can_Never_Be_Null (F_Typ)
3540 and then Known_Null (A)
3542 Apply_Compile_Time_Constraint_Error
3544 Msg => "(Ada 2005) null not allowed in "
3545 & "null-excluding formal?",
3546 Reason => CE_Null_Not_Allowed);
3550 if Ekind (F) = E_Out_Parameter
3551 or else Ekind (F) = E_In_Out_Parameter
3553 if Nkind (A) = N_Type_Conversion then
3554 if Is_Scalar_Type (A_Typ) then
3555 Apply_Scalar_Range_Check
3556 (Expression (A), Etype (Expression (A)), A_Typ);
3559 (Expression (A), Etype (Expression (A)), A_Typ);
3563 if Is_Scalar_Type (F_Typ) then
3564 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3566 elsif Is_Array_Type (F_Typ)
3567 and then Ekind (F) = E_Out_Parameter
3569 Apply_Length_Check (A, F_Typ);
3572 Apply_Range_Check (A, A_Typ, F_Typ);
3577 -- An actual associated with an access parameter is implicitly
3578 -- converted to the anonymous access type of the formal and must
3579 -- satisfy the legality checks for access conversions.
3581 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3582 if not Valid_Conversion (A, F_Typ, A) then
3584 ("invalid implicit conversion for access parameter", A);
3588 -- Check bad case of atomic/volatile argument (RM C.6(12))
3590 if Is_By_Reference_Type (Etype (F))
3591 and then Comes_From_Source (N)
3593 if Is_Atomic_Object (A)
3594 and then not Is_Atomic (Etype (F))
3597 ("cannot pass atomic argument to non-atomic formal",
3600 elsif Is_Volatile_Object (A)
3601 and then not Is_Volatile (Etype (F))
3604 ("cannot pass volatile argument to non-volatile formal",
3609 -- Check that subprograms don't have improper controlling
3610 -- arguments (RM 3.9.2 (9)).
3612 -- A primitive operation may have an access parameter of an
3613 -- incomplete tagged type, but a dispatching call is illegal
3614 -- if the type is still incomplete.
3616 if Is_Controlling_Formal (F) then
3617 Set_Is_Controlling_Actual (A);
3619 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3621 Desig : constant Entity_Id := Designated_Type (Etype (F));
3623 if Ekind (Desig) = E_Incomplete_Type
3624 and then No (Full_View (Desig))
3625 and then No (Non_Limited_View (Desig))
3628 ("premature use of incomplete type& " &
3629 "in dispatching call", A, Desig);
3634 elsif Nkind (A) = N_Explicit_Dereference then
3635 Validate_Remote_Access_To_Class_Wide_Type (A);
3638 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3639 and then not Is_Class_Wide_Type (F_Typ)
3640 and then not Is_Controlling_Formal (F)
3642 Error_Msg_N ("class-wide argument not allowed here!", A);
3644 if Is_Subprogram (Nam)
3645 and then Comes_From_Source (Nam)
3647 Error_Msg_Node_2 := F_Typ;
3649 ("& is not a dispatching operation of &!", A, Nam);
3652 elsif Is_Access_Type (A_Typ)
3653 and then Is_Access_Type (F_Typ)
3654 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3655 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3656 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3657 or else (Nkind (A) = N_Attribute_Reference
3659 Is_Class_Wide_Type (Etype (Prefix (A)))))
3660 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3661 and then not Is_Controlling_Formal (F)
3664 ("access to class-wide argument not allowed here!", A);
3666 if Is_Subprogram (Nam)
3667 and then Comes_From_Source (Nam)
3669 Error_Msg_Node_2 := Designated_Type (F_Typ);
3671 ("& is not a dispatching operation of &!", A, Nam);
3677 -- If it is a named association, treat the selector_name as
3678 -- a proper identifier, and mark the corresponding entity.
3680 if Nkind (Parent (A)) = N_Parameter_Association then
3681 Set_Entity (Selector_Name (Parent (A)), F);
3682 Generate_Reference (F, Selector_Name (Parent (A)));
3683 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3684 Generate_Reference (F_Typ, N, ' ');
3689 if Ekind (F) /= E_Out_Parameter then
3690 Check_Unset_Reference (A);
3695 -- Case where actual is not present
3703 end Resolve_Actuals;
3705 -----------------------
3706 -- Resolve_Allocator --
3707 -----------------------
3709 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3710 E : constant Node_Id := Expression (N);
3712 Discrim : Entity_Id;
3715 Assoc : Node_Id := Empty;
3718 procedure Check_Allocator_Discrim_Accessibility
3719 (Disc_Exp : Node_Id;
3720 Alloc_Typ : Entity_Id);
3721 -- Check that accessibility level associated with an access discriminant
3722 -- initialized in an allocator by the expression Disc_Exp is not deeper
3723 -- than the level of the allocator type Alloc_Typ. An error message is
3724 -- issued if this condition is violated. Specialized checks are done for
3725 -- the cases of a constraint expression which is an access attribute or
3726 -- an access discriminant.
3728 function In_Dispatching_Context return Boolean;
3729 -- If the allocator is an actual in a call, it is allowed to be class-
3730 -- wide when the context is not because it is a controlling actual.
3732 procedure Propagate_Coextensions (Root : Node_Id);
3733 -- Propagate all nested coextensions which are located one nesting
3734 -- level down the tree to the node Root. Example:
3737 -- Level_1_Coextension
3738 -- Level_2_Coextension
3740 -- The algorithm is paired with delay actions done by the Expander. In
3741 -- the above example, assume all coextensions are controlled types.
3742 -- The cycle of analysis, resolution and expansion will yield:
3744 -- 1) Analyze Top_Record
3745 -- 2) Analyze Level_1_Coextension
3746 -- 3) Analyze Level_2_Coextension
3747 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3749 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3750 -- generated to capture the allocated object. Temp_1 is attached
3751 -- to the coextension chain of Level_2_Coextension.
3752 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3753 -- coextension. A forward tree traversal is performed which finds
3754 -- Level_2_Coextension's list and copies its contents into its
3756 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3757 -- generated to capture the allocated object. Temp_2 is attached
3758 -- to the coextension chain of Level_1_Coextension. Currently, the
3759 -- contents of the list are [Temp_2, Temp_1].
3760 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3761 -- finds Level_1_Coextension's list and copies its contents into
3763 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3764 -- Temp_2 and attach them to Top_Record's finalization list.
3766 -------------------------------------------
3767 -- Check_Allocator_Discrim_Accessibility --
3768 -------------------------------------------
3770 procedure Check_Allocator_Discrim_Accessibility
3771 (Disc_Exp : Node_Id;
3772 Alloc_Typ : Entity_Id)
3775 if Type_Access_Level (Etype (Disc_Exp)) >
3776 Type_Access_Level (Alloc_Typ)
3779 ("operand type has deeper level than allocator type", Disc_Exp);
3781 -- When the expression is an Access attribute the level of the prefix
3782 -- object must not be deeper than that of the allocator's type.
3784 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3785 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3787 and then Object_Access_Level (Prefix (Disc_Exp))
3788 > Type_Access_Level (Alloc_Typ)
3791 ("prefix of attribute has deeper level than allocator type",
3794 -- When the expression is an access discriminant the check is against
3795 -- the level of the prefix object.
3797 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3798 and then Nkind (Disc_Exp) = N_Selected_Component
3799 and then Object_Access_Level (Prefix (Disc_Exp))
3800 > Type_Access_Level (Alloc_Typ)
3803 ("access discriminant has deeper level than allocator type",
3806 -- All other cases are legal
3811 end Check_Allocator_Discrim_Accessibility;
3813 ----------------------------
3814 -- In_Dispatching_Context --
3815 ----------------------------
3817 function In_Dispatching_Context return Boolean is
3818 Par : constant Node_Id := Parent (N);
3820 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3821 and then Is_Entity_Name (Name (Par))
3822 and then Is_Dispatching_Operation (Entity (Name (Par)));
3823 end In_Dispatching_Context;
3825 ----------------------------
3826 -- Propagate_Coextensions --
3827 ----------------------------
3829 procedure Propagate_Coextensions (Root : Node_Id) is
3831 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3832 -- Copy the contents of list From into list To, preserving the
3833 -- order of elements.
3835 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3836 -- Recognize an allocator or a rewritten allocator node and add it
3837 -- along with its nested coextensions to the list of Root.
3843 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3844 From_Elmt : Elmt_Id;
3846 From_Elmt := First_Elmt (From);
3847 while Present (From_Elmt) loop
3848 Append_Elmt (Node (From_Elmt), To);
3849 Next_Elmt (From_Elmt);
3853 -----------------------
3854 -- Process_Allocator --
3855 -----------------------
3857 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3858 Orig_Nod : Node_Id := Nod;
3861 -- This is a possible rewritten subtype indication allocator. Any
3862 -- nested coextensions will appear as discriminant constraints.
3864 if Nkind (Nod) = N_Identifier
3865 and then Present (Original_Node (Nod))
3866 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3870 Discr_Elmt : Elmt_Id;
3873 if Is_Record_Type (Entity (Nod)) then
3875 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3876 while Present (Discr_Elmt) loop
3877 Discr := Node (Discr_Elmt);
3879 if Nkind (Discr) = N_Identifier
3880 and then Present (Original_Node (Discr))
3881 and then Nkind (Original_Node (Discr)) = N_Allocator
3882 and then Present (Coextensions (
3883 Original_Node (Discr)))
3885 if No (Coextensions (Root)) then
3886 Set_Coextensions (Root, New_Elmt_List);
3890 (From => Coextensions (Original_Node (Discr)),
3891 To => Coextensions (Root));
3894 Next_Elmt (Discr_Elmt);
3897 -- There is no need to continue the traversal of this
3898 -- subtree since all the information has already been
3905 -- Case of either a stand alone allocator or a rewritten allocator
3906 -- with an aggregate.
3909 if Present (Original_Node (Nod)) then
3910 Orig_Nod := Original_Node (Nod);
3913 if Nkind (Orig_Nod) = N_Allocator then
3915 -- Propagate the list of nested coextensions to the Root
3916 -- allocator. This is done through list copy since a single
3917 -- allocator may have multiple coextensions. Do not touch
3918 -- coextensions roots.
3920 if not Is_Coextension_Root (Orig_Nod)
3921 and then Present (Coextensions (Orig_Nod))
3923 if No (Coextensions (Root)) then
3924 Set_Coextensions (Root, New_Elmt_List);
3928 (From => Coextensions (Orig_Nod),
3929 To => Coextensions (Root));
3932 -- There is no need to continue the traversal of this
3933 -- subtree since all the information has already been
3940 -- Keep on traversing, looking for the next allocator
3943 end Process_Allocator;
3945 procedure Process_Allocators is
3946 new Traverse_Proc (Process_Allocator);
3948 -- Start of processing for Propagate_Coextensions
3951 Process_Allocators (Expression (Root));
3952 end Propagate_Coextensions;
3954 -- Start of processing for Resolve_Allocator
3957 -- Replace general access with specific type
3959 if Ekind (Etype (N)) = E_Allocator_Type then
3960 Set_Etype (N, Base_Type (Typ));
3963 if Is_Abstract_Type (Typ) then
3964 Error_Msg_N ("type of allocator cannot be abstract", N);
3967 -- For qualified expression, resolve the expression using the
3968 -- given subtype (nothing to do for type mark, subtype indication)
3970 if Nkind (E) = N_Qualified_Expression then
3971 if Is_Class_Wide_Type (Etype (E))
3972 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3973 and then not In_Dispatching_Context
3976 ("class-wide allocator not allowed for this access type", N);
3979 Resolve (Expression (E), Etype (E));
3980 Check_Unset_Reference (Expression (E));
3982 -- A qualified expression requires an exact match of the type,
3983 -- class-wide matching is not allowed.
3985 if (Is_Class_Wide_Type (Etype (Expression (E)))
3986 or else Is_Class_Wide_Type (Etype (E)))
3987 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3989 Wrong_Type (Expression (E), Etype (E));
3992 -- A special accessibility check is needed for allocators that
3993 -- constrain access discriminants. The level of the type of the
3994 -- expression used to constrain an access discriminant cannot be
3995 -- deeper than the type of the allocator (in contrast to access
3996 -- parameters, where the level of the actual can be arbitrary).
3998 -- We can't use Valid_Conversion to perform this check because
3999 -- in general the type of the allocator is unrelated to the type
4000 -- of the access discriminant.
4002 if Ekind (Typ) /= E_Anonymous_Access_Type
4003 or else Is_Local_Anonymous_Access (Typ)
4005 Subtyp := Entity (Subtype_Mark (E));
4007 Aggr := Original_Node (Expression (E));
4009 if Has_Discriminants (Subtyp)
4010 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4012 Discrim := First_Discriminant (Base_Type (Subtyp));
4014 -- Get the first component expression of the aggregate
4016 if Present (Expressions (Aggr)) then
4017 Disc_Exp := First (Expressions (Aggr));
4019 elsif Present (Component_Associations (Aggr)) then
4020 Assoc := First (Component_Associations (Aggr));
4022 if Present (Assoc) then
4023 Disc_Exp := Expression (Assoc);
4032 while Present (Discrim) and then Present (Disc_Exp) loop
4033 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4034 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4037 Next_Discriminant (Discrim);
4039 if Present (Discrim) then
4040 if Present (Assoc) then
4042 Disc_Exp := Expression (Assoc);
4044 elsif Present (Next (Disc_Exp)) then
4048 Assoc := First (Component_Associations (Aggr));
4050 if Present (Assoc) then
4051 Disc_Exp := Expression (Assoc);
4061 -- For a subtype mark or subtype indication, freeze the subtype
4064 Freeze_Expression (E);
4066 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4068 ("initialization required for access-to-constant allocator", N);
4071 -- A special accessibility check is needed for allocators that
4072 -- constrain access discriminants. The level of the type of the
4073 -- expression used to constrain an access discriminant cannot be
4074 -- deeper than the type of the allocator (in contrast to access
4075 -- parameters, where the level of the actual can be arbitrary).
4076 -- We can't use Valid_Conversion to perform this check because
4077 -- in general the type of the allocator is unrelated to the type
4078 -- of the access discriminant.
4080 if Nkind (Original_Node (E)) = N_Subtype_Indication
4081 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4082 or else Is_Local_Anonymous_Access (Typ))
4084 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4086 if Has_Discriminants (Subtyp) then
4087 Discrim := First_Discriminant (Base_Type (Subtyp));
4088 Constr := First (Constraints (Constraint (Original_Node (E))));
4089 while Present (Discrim) and then Present (Constr) loop
4090 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4091 if Nkind (Constr) = N_Discriminant_Association then
4092 Disc_Exp := Original_Node (Expression (Constr));
4094 Disc_Exp := Original_Node (Constr);
4097 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4100 Next_Discriminant (Discrim);
4107 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4108 -- check that the level of the type of the created object is not deeper
4109 -- than the level of the allocator's access type, since extensions can
4110 -- now occur at deeper levels than their ancestor types. This is a
4111 -- static accessibility level check; a run-time check is also needed in
4112 -- the case of an initialized allocator with a class-wide argument (see
4113 -- Expand_Allocator_Expression).
4115 if Ada_Version >= Ada_05
4116 and then Is_Class_Wide_Type (Designated_Type (Typ))
4119 Exp_Typ : Entity_Id;
4122 if Nkind (E) = N_Qualified_Expression then
4123 Exp_Typ := Etype (E);
4124 elsif Nkind (E) = N_Subtype_Indication then
4125 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4127 Exp_Typ := Entity (E);
4130 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4131 if In_Instance_Body then
4132 Error_Msg_N ("?type in allocator has deeper level than" &
4133 " designated class-wide type", E);
4134 Error_Msg_N ("\?Program_Error will be raised at run time",
4137 Make_Raise_Program_Error (Sloc (N),
4138 Reason => PE_Accessibility_Check_Failed));
4141 -- Do not apply Ada 2005 accessibility checks on a class-wide
4142 -- allocator if the type given in the allocator is a formal
4143 -- type. A run-time check will be performed in the instance.
4145 elsif not Is_Generic_Type (Exp_Typ) then
4146 Error_Msg_N ("type in allocator has deeper level than" &
4147 " designated class-wide type", E);
4153 -- Check for allocation from an empty storage pool
4155 if No_Pool_Assigned (Typ) then
4157 Loc : constant Source_Ptr := Sloc (N);
4159 Error_Msg_N ("?allocation from empty storage pool!", N);
4160 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4162 Make_Raise_Storage_Error (Loc,
4163 Reason => SE_Empty_Storage_Pool));
4166 -- If the context is an unchecked conversion, as may happen within
4167 -- an inlined subprogram, the allocator is being resolved with its
4168 -- own anonymous type. In that case, if the target type has a specific
4169 -- storage pool, it must be inherited explicitly by the allocator type.
4171 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4172 and then No (Associated_Storage_Pool (Typ))
4174 Set_Associated_Storage_Pool
4175 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4178 -- An erroneous allocator may be rewritten as a raise Program_Error
4181 if Nkind (N) = N_Allocator then
4183 -- An anonymous access discriminant is the definition of a
4186 if Ekind (Typ) = E_Anonymous_Access_Type
4187 and then Nkind (Associated_Node_For_Itype (Typ)) =
4188 N_Discriminant_Specification
4190 -- Avoid marking an allocator as a dynamic coextension if it is
4191 -- within a static construct.
4193 if not Is_Static_Coextension (N) then
4194 Set_Is_Dynamic_Coextension (N);
4197 -- Cleanup for potential static coextensions
4200 Set_Is_Dynamic_Coextension (N, False);
4201 Set_Is_Static_Coextension (N, False);
4204 -- There is no need to propagate any nested coextensions if they
4205 -- are marked as static since they will be rewritten on the spot.
4207 if not Is_Static_Coextension (N) then
4208 Propagate_Coextensions (N);
4211 end Resolve_Allocator;
4213 ---------------------------
4214 -- Resolve_Arithmetic_Op --
4215 ---------------------------
4217 -- Used for resolving all arithmetic operators except exponentiation
4219 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4220 L : constant Node_Id := Left_Opnd (N);
4221 R : constant Node_Id := Right_Opnd (N);
4222 TL : constant Entity_Id := Base_Type (Etype (L));
4223 TR : constant Entity_Id := Base_Type (Etype (R));
4227 B_Typ : constant Entity_Id := Base_Type (Typ);
4228 -- We do the resolution using the base type, because intermediate values
4229 -- in expressions always are of the base type, not a subtype of it.
4231 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4232 -- Returns True if N is in a context that expects "any real type"
4234 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4235 -- Return True iff given type is Integer or universal real/integer
4237 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4238 -- Choose type of integer literal in fixed-point operation to conform
4239 -- to available fixed-point type. T is the type of the other operand,
4240 -- which is needed to determine the expected type of N.
4242 procedure Set_Operand_Type (N : Node_Id);
4243 -- Set operand type to T if universal
4245 -------------------------------
4246 -- Expected_Type_Is_Any_Real --
4247 -------------------------------
4249 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4251 -- N is the expression after "delta" in a fixed_point_definition;
4254 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4255 N_Decimal_Fixed_Point_Definition,
4257 -- N is one of the bounds in a real_range_specification;
4260 N_Real_Range_Specification,
4262 -- N is the expression of a delta_constraint;
4265 N_Delta_Constraint);
4266 end Expected_Type_Is_Any_Real;
4268 -----------------------------
4269 -- Is_Integer_Or_Universal --
4270 -----------------------------
4272 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4274 Index : Interp_Index;
4278 if not Is_Overloaded (N) then
4280 return Base_Type (T) = Base_Type (Standard_Integer)
4281 or else T = Universal_Integer
4282 or else T = Universal_Real;
4284 Get_First_Interp (N, Index, It);
4285 while Present (It.Typ) loop
4286 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4287 or else It.Typ = Universal_Integer
4288 or else It.Typ = Universal_Real
4293 Get_Next_Interp (Index, It);
4298 end Is_Integer_Or_Universal;
4300 ----------------------------
4301 -- Set_Mixed_Mode_Operand --
4302 ----------------------------
4304 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4305 Index : Interp_Index;
4309 if Universal_Interpretation (N) = Universal_Integer then
4311 -- A universal integer literal is resolved as standard integer
4312 -- except in the case of a fixed-point result, where we leave it
4313 -- as universal (to be handled by Exp_Fixd later on)
4315 if Is_Fixed_Point_Type (T) then
4316 Resolve (N, Universal_Integer);
4318 Resolve (N, Standard_Integer);
4321 elsif Universal_Interpretation (N) = Universal_Real
4322 and then (T = Base_Type (Standard_Integer)
4323 or else T = Universal_Integer
4324 or else T = Universal_Real)
4326 -- A universal real can appear in a fixed-type context. We resolve
4327 -- the literal with that context, even though this might raise an
4328 -- exception prematurely (the other operand may be zero).
4332 elsif Etype (N) = Base_Type (Standard_Integer)
4333 and then T = Universal_Real
4334 and then Is_Overloaded (N)
4336 -- Integer arg in mixed-mode operation. Resolve with universal
4337 -- type, in case preference rule must be applied.
4339 Resolve (N, Universal_Integer);
4342 and then B_Typ /= Universal_Fixed
4344 -- Not a mixed-mode operation, resolve with context
4348 elsif Etype (N) = Any_Fixed then
4350 -- N may itself be a mixed-mode operation, so use context type
4354 elsif Is_Fixed_Point_Type (T)
4355 and then B_Typ = Universal_Fixed
4356 and then Is_Overloaded (N)
4358 -- Must be (fixed * fixed) operation, operand must have one
4359 -- compatible interpretation.
4361 Resolve (N, Any_Fixed);
4363 elsif Is_Fixed_Point_Type (B_Typ)
4364 and then (T = Universal_Real
4365 or else Is_Fixed_Point_Type (T))
4366 and then Is_Overloaded (N)
4368 -- C * F(X) in a fixed context, where C is a real literal or a
4369 -- fixed-point expression. F must have either a fixed type
4370 -- interpretation or an integer interpretation, but not both.
4372 Get_First_Interp (N, Index, It);
4373 while Present (It.Typ) loop
4374 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4376 if Analyzed (N) then
4377 Error_Msg_N ("ambiguous operand in fixed operation", N);
4379 Resolve (N, Standard_Integer);
4382 elsif Is_Fixed_Point_Type (It.Typ) then
4384 if Analyzed (N) then
4385 Error_Msg_N ("ambiguous operand in fixed operation", N);
4387 Resolve (N, It.Typ);
4391 Get_Next_Interp (Index, It);
4394 -- Reanalyze the literal with the fixed type of the context. If
4395 -- context is Universal_Fixed, we are within a conversion, leave
4396 -- the literal as a universal real because there is no usable
4397 -- fixed type, and the target of the conversion plays no role in
4411 if B_Typ = Universal_Fixed
4412 and then Nkind (Op2) = N_Real_Literal
4414 T2 := Universal_Real;
4419 Set_Analyzed (Op2, False);
4426 end Set_Mixed_Mode_Operand;
4428 ----------------------
4429 -- Set_Operand_Type --
4430 ----------------------
4432 procedure Set_Operand_Type (N : Node_Id) is
4434 if Etype (N) = Universal_Integer
4435 or else Etype (N) = Universal_Real
4439 end Set_Operand_Type;
4441 -- Start of processing for Resolve_Arithmetic_Op
4444 if Comes_From_Source (N)
4445 and then Ekind (Entity (N)) = E_Function
4446 and then Is_Imported (Entity (N))
4447 and then Is_Intrinsic_Subprogram (Entity (N))
4449 Resolve_Intrinsic_Operator (N, Typ);
4452 -- Special-case for mixed-mode universal expressions or fixed point
4453 -- type operation: each argument is resolved separately. The same
4454 -- treatment is required if one of the operands of a fixed point
4455 -- operation is universal real, since in this case we don't do a
4456 -- conversion to a specific fixed-point type (instead the expander
4457 -- takes care of the case).
4459 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4460 and then Present (Universal_Interpretation (L))
4461 and then Present (Universal_Interpretation (R))
4463 Resolve (L, Universal_Interpretation (L));
4464 Resolve (R, Universal_Interpretation (R));
4465 Set_Etype (N, B_Typ);
4467 elsif (B_Typ = Universal_Real
4468 or else Etype (N) = Universal_Fixed
4469 or else (Etype (N) = Any_Fixed
4470 and then Is_Fixed_Point_Type (B_Typ))
4471 or else (Is_Fixed_Point_Type (B_Typ)
4472 and then (Is_Integer_Or_Universal (L)
4474 Is_Integer_Or_Universal (R))))
4475 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4477 if TL = Universal_Integer or else TR = Universal_Integer then
4478 Check_For_Visible_Operator (N, B_Typ);
4481 -- If context is a fixed type and one operand is integer, the
4482 -- other is resolved with the type of the context.
4484 if Is_Fixed_Point_Type (B_Typ)
4485 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4486 or else TL = Universal_Integer)
4491 elsif Is_Fixed_Point_Type (B_Typ)
4492 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4493 or else TR = Universal_Integer)
4499 Set_Mixed_Mode_Operand (L, TR);
4500 Set_Mixed_Mode_Operand (R, TL);
4503 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4504 -- multiplying operators from being used when the expected type is
4505 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4506 -- some cases where the expected type is actually Any_Real;
4507 -- Expected_Type_Is_Any_Real takes care of that case.
4509 if Etype (N) = Universal_Fixed
4510 or else Etype (N) = Any_Fixed
4512 if B_Typ = Universal_Fixed
4513 and then not Expected_Type_Is_Any_Real (N)
4514 and then not Nkind_In (Parent (N), N_Type_Conversion,
4515 N_Unchecked_Type_Conversion)
4517 Error_Msg_N ("type cannot be determined from context!", N);
4518 Error_Msg_N ("\explicit conversion to result type required", N);
4520 Set_Etype (L, Any_Type);
4521 Set_Etype (R, Any_Type);
4524 if Ada_Version = Ada_83
4525 and then Etype (N) = Universal_Fixed
4527 Nkind_In (Parent (N), N_Type_Conversion,
4528 N_Unchecked_Type_Conversion)
4531 ("(Ada 83) fixed-point operation "
4532 & "needs explicit conversion", N);
4535 -- The expected type is "any real type" in contexts like
4536 -- type T is delta <universal_fixed-expression> ...
4537 -- in which case we need to set the type to Universal_Real
4538 -- so that static expression evaluation will work properly.
4540 if Expected_Type_Is_Any_Real (N) then
4541 Set_Etype (N, Universal_Real);
4543 Set_Etype (N, B_Typ);
4547 elsif Is_Fixed_Point_Type (B_Typ)
4548 and then (Is_Integer_Or_Universal (L)
4549 or else Nkind (L) = N_Real_Literal
4550 or else Nkind (R) = N_Real_Literal
4551 or else Is_Integer_Or_Universal (R))
4553 Set_Etype (N, B_Typ);
4555 elsif Etype (N) = Any_Fixed then
4557 -- If no previous errors, this is only possible if one operand
4558 -- is overloaded and the context is universal. Resolve as such.
4560 Set_Etype (N, B_Typ);
4564 if (TL = Universal_Integer or else TL = Universal_Real)
4566 (TR = Universal_Integer or else TR = Universal_Real)
4568 Check_For_Visible_Operator (N, B_Typ);
4571 -- If the context is Universal_Fixed and the operands are also
4572 -- universal fixed, this is an error, unless there is only one
4573 -- applicable fixed_point type (usually duration).
4575 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4576 T := Unique_Fixed_Point_Type (N);
4578 if T = Any_Type then
4591 -- If one of the arguments was resolved to a non-universal type.
4592 -- label the result of the operation itself with the same type.
4593 -- Do the same for the universal argument, if any.
4595 T := Intersect_Types (L, R);
4596 Set_Etype (N, Base_Type (T));
4597 Set_Operand_Type (L);
4598 Set_Operand_Type (R);
4601 Generate_Operator_Reference (N, Typ);
4602 Eval_Arithmetic_Op (N);
4604 -- Set overflow and division checking bit. Much cleverer code needed
4605 -- here eventually and perhaps the Resolve routines should be separated
4606 -- for the various arithmetic operations, since they will need
4607 -- different processing. ???
4609 if Nkind (N) in N_Op then
4610 if not Overflow_Checks_Suppressed (Etype (N)) then
4611 Enable_Overflow_Check (N);
4614 -- Give warning if explicit division by zero
4616 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4617 and then not Division_Checks_Suppressed (Etype (N))
4619 Rop := Right_Opnd (N);
4621 if Compile_Time_Known_Value (Rop)
4622 and then ((Is_Integer_Type (Etype (Rop))
4623 and then Expr_Value (Rop) = Uint_0)
4625 (Is_Real_Type (Etype (Rop))
4626 and then Expr_Value_R (Rop) = Ureal_0))
4628 -- Specialize the warning message according to the operation
4632 Apply_Compile_Time_Constraint_Error
4633 (N, "division by zero?", CE_Divide_By_Zero,
4634 Loc => Sloc (Right_Opnd (N)));
4637 Apply_Compile_Time_Constraint_Error
4638 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4639 Loc => Sloc (Right_Opnd (N)));
4642 Apply_Compile_Time_Constraint_Error
4643 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4644 Loc => Sloc (Right_Opnd (N)));
4646 -- Division by zero can only happen with division, rem,
4647 -- and mod operations.
4650 raise Program_Error;
4653 -- Otherwise just set the flag to check at run time
4656 Activate_Division_Check (N);
4660 -- If Restriction No_Implicit_Conditionals is active, then it is
4661 -- violated if either operand can be negative for mod, or for rem
4662 -- if both operands can be negative.
4664 if Restrictions.Set (No_Implicit_Conditionals)
4665 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4674 -- Set if corresponding operand might be negative
4677 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4678 LNeg := (not OK) or else Lo < 0;
4680 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4681 RNeg := (not OK) or else Lo < 0;
4683 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4685 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4687 Check_Restriction (No_Implicit_Conditionals, N);
4693 Check_Unset_Reference (L);
4694 Check_Unset_Reference (R);
4695 end Resolve_Arithmetic_Op;
4701 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4702 Loc : constant Source_Ptr := Sloc (N);
4703 Subp : constant Node_Id := Name (N);
4712 -- The context imposes a unique interpretation with type Typ on a
4713 -- procedure or function call. Find the entity of the subprogram that
4714 -- yields the expected type, and propagate the corresponding formal
4715 -- constraints on the actuals. The caller has established that an
4716 -- interpretation exists, and emitted an error if not unique.
4718 -- First deal with the case of a call to an access-to-subprogram,
4719 -- dereference made explicit in Analyze_Call.
4721 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4722 if not Is_Overloaded (Subp) then
4723 Nam := Etype (Subp);
4726 -- Find the interpretation whose type (a subprogram type) has a
4727 -- return type that is compatible with the context. Analysis of
4728 -- the node has established that one exists.
4732 Get_First_Interp (Subp, I, It);
4733 while Present (It.Typ) loop
4734 if Covers (Typ, Etype (It.Typ)) then
4739 Get_Next_Interp (I, It);
4743 raise Program_Error;
4747 -- If the prefix is not an entity, then resolve it
4749 if not Is_Entity_Name (Subp) then
4750 Resolve (Subp, Nam);
4753 -- For an indirect call, we always invalidate checks, since we do not
4754 -- know whether the subprogram is local or global. Yes we could do
4755 -- better here, e.g. by knowing that there are no local subprograms,
4756 -- but it does not seem worth the effort. Similarly, we kill all
4757 -- knowledge of current constant values.
4759 Kill_Current_Values;
4761 -- If this is a procedure call which is really an entry call, do
4762 -- the conversion of the procedure call to an entry call. Protected
4763 -- operations use the same circuitry because the name in the call
4764 -- can be an arbitrary expression with special resolution rules.
4766 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4767 or else (Is_Entity_Name (Subp)
4768 and then Ekind (Entity (Subp)) = E_Entry)
4770 Resolve_Entry_Call (N, Typ);
4771 Check_Elab_Call (N);
4773 -- Kill checks and constant values, as above for indirect case
4774 -- Who knows what happens when another task is activated?
4776 Kill_Current_Values;
4779 -- Normal subprogram call with name established in Resolve
4781 elsif not (Is_Type (Entity (Subp))) then
4782 Nam := Entity (Subp);
4783 Set_Entity_With_Style_Check (Subp, Nam);
4785 -- Otherwise we must have the case of an overloaded call
4788 pragma Assert (Is_Overloaded (Subp));
4790 -- Initialize Nam to prevent warning (we know it will be assigned
4791 -- in the loop below, but the compiler does not know that).
4795 Get_First_Interp (Subp, I, It);
4796 while Present (It.Typ) loop
4797 if Covers (Typ, It.Typ) then
4799 Set_Entity_With_Style_Check (Subp, Nam);
4803 Get_Next_Interp (I, It);
4807 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4808 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4809 and then Nkind (Subp) /= N_Explicit_Dereference
4810 and then Present (Parameter_Associations (N))
4812 -- The prefix is a parameterless function call that returns an access
4813 -- to subprogram. If parameters are present in the current call, add
4814 -- add an explicit dereference. We use the base type here because
4815 -- within an instance these may be subtypes.
4817 -- The dereference is added either in Analyze_Call or here. Should
4818 -- be consolidated ???
4820 Set_Is_Overloaded (Subp, False);
4821 Set_Etype (Subp, Etype (Nam));
4822 Insert_Explicit_Dereference (Subp);
4823 Nam := Designated_Type (Etype (Nam));
4824 Resolve (Subp, Nam);
4827 -- Check that a call to Current_Task does not occur in an entry body
4829 if Is_RTE (Nam, RE_Current_Task) then
4838 -- Exclude calls that occur within the default of a formal
4839 -- parameter of the entry, since those are evaluated outside
4842 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4844 if Nkind (P) = N_Entry_Body
4845 or else (Nkind (P) = N_Subprogram_Body
4846 and then Is_Entry_Barrier_Function (P))
4850 ("?& should not be used in entry body (RM C.7(17))",
4853 ("\Program_Error will be raised at run time?", N, Nam);
4855 Make_Raise_Program_Error (Loc,
4856 Reason => PE_Current_Task_In_Entry_Body));
4857 Set_Etype (N, Rtype);
4864 -- Check that a procedure call does not occur in the context of the
4865 -- entry call statement of a conditional or timed entry call. Note that
4866 -- the case of a call to a subprogram renaming of an entry will also be
4867 -- rejected. The test for N not being an N_Entry_Call_Statement is
4868 -- defensive, covering the possibility that the processing of entry
4869 -- calls might reach this point due to later modifications of the code
4872 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4873 and then Nkind (N) /= N_Entry_Call_Statement
4874 and then Entry_Call_Statement (Parent (N)) = N
4876 if Ada_Version < Ada_05 then
4877 Error_Msg_N ("entry call required in select statement", N);
4879 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4880 -- for a procedure_or_entry_call, the procedure_name or
4881 -- procedure_prefix of the procedure_call_statement shall denote
4882 -- an entry renamed by a procedure, or (a view of) a primitive
4883 -- subprogram of a limited interface whose first parameter is
4884 -- a controlling parameter.
4886 elsif Nkind (N) = N_Procedure_Call_Statement
4887 and then not Is_Renamed_Entry (Nam)
4888 and then not Is_Controlling_Limited_Procedure (Nam)
4891 ("entry call or dispatching primitive of interface required", N);
4895 -- Check that this is not a call to a protected procedure or entry from
4896 -- within a protected function.
4898 if Ekind (Current_Scope) = E_Function
4899 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4900 and then Ekind (Nam) /= E_Function
4901 and then Scope (Nam) = Scope (Current_Scope)
4903 Error_Msg_N ("within protected function, protected " &
4904 "object is constant", N);
4905 Error_Msg_N ("\cannot call operation that may modify it", N);
4908 -- Freeze the subprogram name if not in a spec-expression. Note that we
4909 -- freeze procedure calls as well as function calls. Procedure calls are
4910 -- not frozen according to the rules (RM 13.14(14)) because it is
4911 -- impossible to have a procedure call to a non-frozen procedure in pure
4912 -- Ada, but in the code that we generate in the expander, this rule
4913 -- needs extending because we can generate procedure calls that need
4916 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4917 Freeze_Expression (Subp);
4920 -- For a predefined operator, the type of the result is the type imposed
4921 -- by context, except for a predefined operation on universal fixed.
4922 -- Otherwise The type of the call is the type returned by the subprogram
4925 if Is_Predefined_Op (Nam) then
4926 if Etype (N) /= Universal_Fixed then
4930 -- If the subprogram returns an array type, and the context requires the
4931 -- component type of that array type, the node is really an indexing of
4932 -- the parameterless call. Resolve as such. A pathological case occurs
4933 -- when the type of the component is an access to the array type. In
4934 -- this case the call is truly ambiguous.
4936 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4938 ((Is_Array_Type (Etype (Nam))
4939 and then Covers (Typ, Component_Type (Etype (Nam))))
4940 or else (Is_Access_Type (Etype (Nam))
4941 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4944 Component_Type (Designated_Type (Etype (Nam))))))
4947 Index_Node : Node_Id;
4949 Ret_Type : constant Entity_Id := Etype (Nam);
4952 if Is_Access_Type (Ret_Type)
4953 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4956 ("cannot disambiguate function call and indexing", N);
4958 New_Subp := Relocate_Node (Subp);
4959 Set_Entity (Subp, Nam);
4961 if Component_Type (Ret_Type) /= Any_Type then
4962 if Needs_No_Actuals (Nam) then
4964 -- Indexed call to a parameterless function
4967 Make_Indexed_Component (Loc,
4969 Make_Function_Call (Loc,
4971 Expressions => Parameter_Associations (N));
4973 -- An Ada 2005 prefixed call to a primitive operation
4974 -- whose first parameter is the prefix. This prefix was
4975 -- prepended to the parameter list, which is actually a
4976 -- list of indices. Remove the prefix in order to build
4977 -- the proper indexed component.
4980 Make_Indexed_Component (Loc,
4982 Make_Function_Call (Loc,
4984 Parameter_Associations =>
4986 (Remove_Head (Parameter_Associations (N)))),
4987 Expressions => Parameter_Associations (N));
4990 -- Since we are correcting a node classification error made
4991 -- by the parser, we call Replace rather than Rewrite.
4993 Replace (N, Index_Node);
4994 Set_Etype (Prefix (N), Ret_Type);
4996 Resolve_Indexed_Component (N, Typ);
4997 Check_Elab_Call (Prefix (N));
5005 Set_Etype (N, Etype (Nam));
5008 -- In the case where the call is to an overloaded subprogram, Analyze
5009 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5010 -- such a case Normalize_Actuals needs to be called once more to order
5011 -- the actuals correctly. Otherwise the call will have the ordering
5012 -- given by the last overloaded subprogram whether this is the correct
5013 -- one being called or not.
5015 if Is_Overloaded (Subp) then
5016 Normalize_Actuals (N, Nam, False, Norm_OK);
5017 pragma Assert (Norm_OK);
5020 -- In any case, call is fully resolved now. Reset Overload flag, to
5021 -- prevent subsequent overload resolution if node is analyzed again
5023 Set_Is_Overloaded (Subp, False);
5024 Set_Is_Overloaded (N, False);
5026 -- If we are calling the current subprogram from immediately within its
5027 -- body, then that is the case where we can sometimes detect cases of
5028 -- infinite recursion statically. Do not try this in case restriction
5029 -- No_Recursion is in effect anyway, and do it only for source calls.
5031 if Comes_From_Source (N) then
5032 Scop := Current_Scope;
5034 -- Issue warning for possible infinite recursion in the absence
5035 -- of the No_Recursion restriction.
5038 and then not Restriction_Active (No_Recursion)
5039 and then Check_Infinite_Recursion (N)
5041 -- Here we detected and flagged an infinite recursion, so we do
5042 -- not need to test the case below for further warnings. Also if
5043 -- we now have a raise SE node, we are all done.
5045 if Nkind (N) = N_Raise_Storage_Error then
5049 -- If call is to immediately containing subprogram, then check for
5050 -- the case of a possible run-time detectable infinite recursion.
5053 Scope_Loop : while Scop /= Standard_Standard loop
5056 -- Although in general case, recursion is not statically
5057 -- checkable, the case of calling an immediately containing
5058 -- subprogram is easy to catch.
5060 Check_Restriction (No_Recursion, N);
5062 -- If the recursive call is to a parameterless subprogram,
5063 -- then even if we can't statically detect infinite
5064 -- recursion, this is pretty suspicious, and we output a
5065 -- warning. Furthermore, we will try later to detect some
5066 -- cases here at run time by expanding checking code (see
5067 -- Detect_Infinite_Recursion in package Exp_Ch6).
5069 -- If the recursive call is within a handler, do not emit a
5070 -- warning, because this is a common idiom: loop until input
5071 -- is correct, catch illegal input in handler and restart.
5073 if No (First_Formal (Nam))
5074 and then Etype (Nam) = Standard_Void_Type
5075 and then not Error_Posted (N)
5076 and then Nkind (Parent (N)) /= N_Exception_Handler
5078 -- For the case of a procedure call. We give the message
5079 -- only if the call is the first statement in a sequence
5080 -- of statements, or if all previous statements are
5081 -- simple assignments. This is simply a heuristic to
5082 -- decrease false positives, without losing too many good
5083 -- warnings. The idea is that these previous statements
5084 -- may affect global variables the procedure depends on.
5086 if Nkind (N) = N_Procedure_Call_Statement
5087 and then Is_List_Member (N)
5093 while Present (P) loop
5094 if Nkind (P) /= N_Assignment_Statement then
5103 -- Do not give warning if we are in a conditional context
5106 K : constant Node_Kind := Nkind (Parent (N));
5108 if (K = N_Loop_Statement
5109 and then Present (Iteration_Scheme (Parent (N))))
5110 or else K = N_If_Statement
5111 or else K = N_Elsif_Part
5112 or else K = N_Case_Statement_Alternative
5118 -- Here warning is to be issued
5120 Set_Has_Recursive_Call (Nam);
5122 ("?possible infinite recursion!", N);
5124 ("\?Storage_Error may be raised at run time!", N);
5130 Scop := Scope (Scop);
5131 end loop Scope_Loop;
5135 -- If subprogram name is a predefined operator, it was given in
5136 -- functional notation. Replace call node with operator node, so
5137 -- that actuals can be resolved appropriately.
5139 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5140 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5143 elsif Present (Alias (Nam))
5144 and then Is_Predefined_Op (Alias (Nam))
5146 Resolve_Actuals (N, Nam);
5147 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5151 -- Create a transient scope if the resulting type requires it
5153 -- There are several notable exceptions:
5155 -- a) In init procs, the transient scope overhead is not needed, and is
5156 -- even incorrect when the call is a nested initialization call for a
5157 -- component whose expansion may generate adjust calls. However, if the
5158 -- call is some other procedure call within an initialization procedure
5159 -- (for example a call to Create_Task in the init_proc of the task
5160 -- run-time record) a transient scope must be created around this call.
5162 -- b) Enumeration literal pseudo-calls need no transient scope
5164 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5165 -- functions) do not use the secondary stack even though the return
5166 -- type may be unconstrained.
5168 -- d) Calls to a build-in-place function, since such functions may
5169 -- allocate their result directly in a target object, and cases where
5170 -- the result does get allocated in the secondary stack are checked for
5171 -- within the specialized Exp_Ch6 procedures for expanding those
5172 -- build-in-place calls.
5174 -- e) If the subprogram is marked Inline_Always, then even if it returns
5175 -- an unconstrained type the call does not require use of the secondary
5176 -- stack. However, inlining will only take place if the body to inline
5177 -- is already present. It may not be available if e.g. the subprogram is
5178 -- declared in a child instance.
5180 -- If this is an initialization call for a type whose construction
5181 -- uses the secondary stack, and it is not a nested call to initialize
5182 -- a component, we do need to create a transient scope for it. We
5183 -- check for this by traversing the type in Check_Initialization_Call.
5186 and then Has_Pragma_Inline_Always (Nam)
5187 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5188 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5192 elsif Ekind (Nam) = E_Enumeration_Literal
5193 or else Is_Build_In_Place_Function (Nam)
5194 or else Is_Intrinsic_Subprogram (Nam)
5198 elsif Expander_Active
5199 and then Is_Type (Etype (Nam))
5200 and then Requires_Transient_Scope (Etype (Nam))
5202 (not Within_Init_Proc
5204 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5206 Establish_Transient_Scope (N, Sec_Stack => True);
5208 -- If the call appears within the bounds of a loop, it will
5209 -- be rewritten and reanalyzed, nothing left to do here.
5211 if Nkind (N) /= N_Function_Call then
5215 elsif Is_Init_Proc (Nam)
5216 and then not Within_Init_Proc
5218 Check_Initialization_Call (N, Nam);
5221 -- A protected function cannot be called within the definition of the
5222 -- enclosing protected type.
5224 if Is_Protected_Type (Scope (Nam))
5225 and then In_Open_Scopes (Scope (Nam))
5226 and then not Has_Completion (Scope (Nam))
5229 ("& cannot be called before end of protected definition", N, Nam);
5232 -- Propagate interpretation to actuals, and add default expressions
5235 if Present (First_Formal (Nam)) then
5236 Resolve_Actuals (N, Nam);
5238 -- Overloaded literals are rewritten as function calls, for purpose of
5239 -- resolution. After resolution, we can replace the call with the
5242 elsif Ekind (Nam) = E_Enumeration_Literal then
5243 Copy_Node (Subp, N);
5244 Resolve_Entity_Name (N, Typ);
5246 -- Avoid validation, since it is a static function call
5248 Generate_Reference (Nam, Subp);
5252 -- If the subprogram is not global, then kill all saved values and
5253 -- checks. This is a bit conservative, since in many cases we could do
5254 -- better, but it is not worth the effort. Similarly, we kill constant
5255 -- values. However we do not need to do this for internal entities
5256 -- (unless they are inherited user-defined subprograms), since they
5257 -- are not in the business of molesting local values.
5259 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5260 -- kill all checks and values for calls to global subprograms. This
5261 -- takes care of the case where an access to a local subprogram is
5262 -- taken, and could be passed directly or indirectly and then called
5263 -- from almost any context.
5265 -- Note: we do not do this step till after resolving the actuals. That
5266 -- way we still take advantage of the current value information while
5267 -- scanning the actuals.
5269 -- We suppress killing values if we are processing the nodes associated
5270 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5271 -- type kills all the values as part of analyzing the code that
5272 -- initializes the dispatch tables.
5274 if Inside_Freezing_Actions = 0
5275 and then (not Is_Library_Level_Entity (Nam)
5276 or else Suppress_Value_Tracking_On_Call
5277 (Nearest_Dynamic_Scope (Current_Scope)))
5278 and then (Comes_From_Source (Nam)
5279 or else (Present (Alias (Nam))
5280 and then Comes_From_Source (Alias (Nam))))
5282 Kill_Current_Values;
5285 -- If we are warning about unread OUT parameters, this is the place to
5286 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5287 -- after the above call to Kill_Current_Values (since that call clears
5288 -- the Last_Assignment field of all local variables).
5290 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5291 and then Comes_From_Source (N)
5292 and then In_Extended_Main_Source_Unit (N)
5299 F := First_Formal (Nam);
5300 A := First_Actual (N);
5301 while Present (F) and then Present (A) loop
5302 if (Ekind (F) = E_Out_Parameter
5304 Ekind (F) = E_In_Out_Parameter)
5305 and then Warn_On_Modified_As_Out_Parameter (F)
5306 and then Is_Entity_Name (A)
5307 and then Present (Entity (A))
5308 and then Comes_From_Source (N)
5309 and then Safe_To_Capture_Value (N, Entity (A))
5311 Set_Last_Assignment (Entity (A), A);
5320 -- If the subprogram is a primitive operation, check whether or not
5321 -- it is a correct dispatching call.
5323 if Is_Overloadable (Nam)
5324 and then Is_Dispatching_Operation (Nam)
5326 Check_Dispatching_Call (N);
5328 elsif Ekind (Nam) /= E_Subprogram_Type
5329 and then Is_Abstract_Subprogram (Nam)
5330 and then not In_Instance
5332 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5335 -- If this is a dispatching call, generate the appropriate reference,
5336 -- for better source navigation in GPS.
5338 if Is_Overloadable (Nam)
5339 and then Present (Controlling_Argument (N))
5341 Generate_Reference (Nam, Subp, 'R');
5343 -- Normal case, not a dispatching call
5346 Generate_Reference (Nam, Subp);
5349 if Is_Intrinsic_Subprogram (Nam) then
5350 Check_Intrinsic_Call (N);
5353 -- Check for violation of restriction No_Specific_Termination_Handlers
5354 -- and warn on a potentially blocking call to Abort_Task.
5356 if Is_RTE (Nam, RE_Set_Specific_Handler)
5358 Is_RTE (Nam, RE_Specific_Handler)
5360 Check_Restriction (No_Specific_Termination_Handlers, N);
5362 elsif Is_RTE (Nam, RE_Abort_Task) then
5363 Check_Potentially_Blocking_Operation (N);
5366 -- Issue an error for a call to an eliminated subprogram
5368 Check_For_Eliminated_Subprogram (Subp, Nam);
5370 -- All done, evaluate call and deal with elaboration issues
5373 Check_Elab_Call (N);
5376 -------------------------------
5377 -- Resolve_Character_Literal --
5378 -------------------------------
5380 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5381 B_Typ : constant Entity_Id := Base_Type (Typ);
5385 -- Verify that the character does belong to the type of the context
5387 Set_Etype (N, B_Typ);
5388 Eval_Character_Literal (N);
5390 -- Wide_Wide_Character literals must always be defined, since the set
5391 -- of wide wide character literals is complete, i.e. if a character
5392 -- literal is accepted by the parser, then it is OK for wide wide
5393 -- character (out of range character literals are rejected).
5395 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5398 -- Always accept character literal for type Any_Character, which
5399 -- occurs in error situations and in comparisons of literals, both
5400 -- of which should accept all literals.
5402 elsif B_Typ = Any_Character then
5405 -- For Standard.Character or a type derived from it, check that
5406 -- the literal is in range
5408 elsif Root_Type (B_Typ) = Standard_Character then
5409 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5413 -- For Standard.Wide_Character or a type derived from it, check
5414 -- that the literal is in range
5416 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5417 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5421 -- For Standard.Wide_Wide_Character or a type derived from it, we
5422 -- know the literal is in range, since the parser checked!
5424 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5427 -- If the entity is already set, this has already been resolved in a
5428 -- generic context, or comes from expansion. Nothing else to do.
5430 elsif Present (Entity (N)) then
5433 -- Otherwise we have a user defined character type, and we can use the
5434 -- standard visibility mechanisms to locate the referenced entity.
5437 C := Current_Entity (N);
5438 while Present (C) loop
5439 if Etype (C) = B_Typ then
5440 Set_Entity_With_Style_Check (N, C);
5441 Generate_Reference (C, N);
5449 -- If we fall through, then the literal does not match any of the
5450 -- entries of the enumeration type. This isn't just a constraint
5451 -- error situation, it is an illegality (see RM 4.2).
5454 ("character not defined for }", N, First_Subtype (B_Typ));
5455 end Resolve_Character_Literal;
5457 ---------------------------
5458 -- Resolve_Comparison_Op --
5459 ---------------------------
5461 -- Context requires a boolean type, and plays no role in resolution.
5462 -- Processing identical to that for equality operators. The result
5463 -- type is the base type, which matters when pathological subtypes of
5464 -- booleans with limited ranges are used.
5466 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5467 L : constant Node_Id := Left_Opnd (N);
5468 R : constant Node_Id := Right_Opnd (N);
5472 Check_No_Direct_Boolean_Operators (N);
5474 -- If this is an intrinsic operation which is not predefined, use the
5475 -- types of its declared arguments to resolve the possibly overloaded
5476 -- operands. Otherwise the operands are unambiguous and specify the
5479 if Scope (Entity (N)) /= Standard_Standard then
5480 T := Etype (First_Entity (Entity (N)));
5483 T := Find_Unique_Type (L, R);
5485 if T = Any_Fixed then
5486 T := Unique_Fixed_Point_Type (L);
5490 Set_Etype (N, Base_Type (Typ));
5491 Generate_Reference (T, N, ' ');
5493 if T /= Any_Type then
5494 if T = Any_String or else
5495 T = Any_Composite or else
5498 if T = Any_Character then
5499 Ambiguous_Character (L);
5501 Error_Msg_N ("ambiguous operands for comparison", N);
5504 Set_Etype (N, Any_Type);
5510 Check_Unset_Reference (L);
5511 Check_Unset_Reference (R);
5512 Generate_Operator_Reference (N, T);
5513 Check_Low_Bound_Tested (N);
5514 Eval_Relational_Op (N);
5517 end Resolve_Comparison_Op;
5519 ------------------------------------
5520 -- Resolve_Conditional_Expression --
5521 ------------------------------------
5523 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5524 Condition : constant Node_Id := First (Expressions (N));
5525 Then_Expr : constant Node_Id := Next (Condition);
5526 Else_Expr : constant Node_Id := Next (Then_Expr);
5528 Resolve (Condition, Standard_Boolean);
5529 Resolve (Then_Expr, Typ);
5530 Resolve (Else_Expr, Typ);
5532 Eval_Conditional_Expression (N);
5533 end Resolve_Conditional_Expression;
5535 -----------------------------------------
5536 -- Resolve_Discrete_Subtype_Indication --
5537 -----------------------------------------
5539 procedure Resolve_Discrete_Subtype_Indication
5547 Analyze (Subtype_Mark (N));
5548 S := Entity (Subtype_Mark (N));
5550 if Nkind (Constraint (N)) /= N_Range_Constraint then
5551 Error_Msg_N ("expect range constraint for discrete type", N);
5552 Set_Etype (N, Any_Type);
5555 R := Range_Expression (Constraint (N));
5563 if Base_Type (S) /= Base_Type (Typ) then
5565 ("expect subtype of }", N, First_Subtype (Typ));
5567 -- Rewrite the constraint as a range of Typ
5568 -- to allow compilation to proceed further.
5571 Rewrite (Low_Bound (R),
5572 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5573 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5574 Attribute_Name => Name_First));
5575 Rewrite (High_Bound (R),
5576 Make_Attribute_Reference (Sloc (High_Bound (R)),
5577 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5578 Attribute_Name => Name_First));
5582 Set_Etype (N, Etype (R));
5584 -- Additionally, we must check that the bounds are compatible
5585 -- with the given subtype, which might be different from the
5586 -- type of the context.
5588 Apply_Range_Check (R, S);
5590 -- ??? If the above check statically detects a Constraint_Error
5591 -- it replaces the offending bound(s) of the range R with a
5592 -- Constraint_Error node. When the itype which uses these bounds
5593 -- is frozen the resulting call to Duplicate_Subexpr generates
5594 -- a new temporary for the bounds.
5596 -- Unfortunately there are other itypes that are also made depend
5597 -- on these bounds, so when Duplicate_Subexpr is called they get
5598 -- a forward reference to the newly created temporaries and Gigi
5599 -- aborts on such forward references. This is probably sign of a
5600 -- more fundamental problem somewhere else in either the order of
5601 -- itype freezing or the way certain itypes are constructed.
5603 -- To get around this problem we call Remove_Side_Effects right
5604 -- away if either bounds of R are a Constraint_Error.
5607 L : constant Node_Id := Low_Bound (R);
5608 H : constant Node_Id := High_Bound (R);
5611 if Nkind (L) = N_Raise_Constraint_Error then
5612 Remove_Side_Effects (L);
5615 if Nkind (H) = N_Raise_Constraint_Error then
5616 Remove_Side_Effects (H);
5620 Check_Unset_Reference (Low_Bound (R));
5621 Check_Unset_Reference (High_Bound (R));
5624 end Resolve_Discrete_Subtype_Indication;
5626 -------------------------
5627 -- Resolve_Entity_Name --
5628 -------------------------
5630 -- Used to resolve identifiers and expanded names
5632 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5633 E : constant Entity_Id := Entity (N);
5636 -- If garbage from errors, set to Any_Type and return
5638 if No (E) and then Total_Errors_Detected /= 0 then
5639 Set_Etype (N, Any_Type);
5643 -- Replace named numbers by corresponding literals. Note that this is
5644 -- the one case where Resolve_Entity_Name must reset the Etype, since
5645 -- it is currently marked as universal.
5647 if Ekind (E) = E_Named_Integer then
5649 Eval_Named_Integer (N);
5651 elsif Ekind (E) = E_Named_Real then
5653 Eval_Named_Real (N);
5655 -- Allow use of subtype only if it is a concurrent type where we are
5656 -- currently inside the body. This will eventually be expanded into a
5657 -- call to Self (for tasks) or _object (for protected objects). Any
5658 -- other use of a subtype is invalid.
5660 elsif Is_Type (E) then
5661 if Is_Concurrent_Type (E)
5662 and then In_Open_Scopes (E)
5667 ("invalid use of subtype mark in expression or call", N);
5670 -- Check discriminant use if entity is discriminant in current scope,
5671 -- i.e. discriminant of record or concurrent type currently being
5672 -- analyzed. Uses in corresponding body are unrestricted.
5674 elsif Ekind (E) = E_Discriminant
5675 and then Scope (E) = Current_Scope
5676 and then not Has_Completion (Current_Scope)
5678 Check_Discriminant_Use (N);
5680 -- A parameterless generic function cannot appear in a context that
5681 -- requires resolution.
5683 elsif Ekind (E) = E_Generic_Function then
5684 Error_Msg_N ("illegal use of generic function", N);
5686 elsif Ekind (E) = E_Out_Parameter
5687 and then Ada_Version = Ada_83
5688 and then (Nkind (Parent (N)) in N_Op
5689 or else (Nkind (Parent (N)) = N_Assignment_Statement
5690 and then N = Expression (Parent (N)))
5691 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5693 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5695 -- In all other cases, just do the possible static evaluation
5698 -- A deferred constant that appears in an expression must have a
5699 -- completion, unless it has been removed by in-place expansion of
5702 if Ekind (E) = E_Constant
5703 and then Comes_From_Source (E)
5704 and then No (Constant_Value (E))
5705 and then Is_Frozen (Etype (E))
5706 and then not In_Spec_Expression
5707 and then not Is_Imported (E)
5710 if No_Initialization (Parent (E))
5711 or else (Present (Full_View (E))
5712 and then No_Initialization (Parent (Full_View (E))))
5717 "deferred constant is frozen before completion", N);
5721 Eval_Entity_Name (N);
5723 end Resolve_Entity_Name;
5729 procedure Resolve_Entry (Entry_Name : Node_Id) is
5730 Loc : constant Source_Ptr := Sloc (Entry_Name);
5738 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5739 -- If the bounds of the entry family being called depend on task
5740 -- discriminants, build a new index subtype where a discriminant is
5741 -- replaced with the value of the discriminant of the target task.
5742 -- The target task is the prefix of the entry name in the call.
5744 -----------------------
5745 -- Actual_Index_Type --
5746 -----------------------
5748 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5749 Typ : constant Entity_Id := Entry_Index_Type (E);
5750 Tsk : constant Entity_Id := Scope (E);
5751 Lo : constant Node_Id := Type_Low_Bound (Typ);
5752 Hi : constant Node_Id := Type_High_Bound (Typ);
5755 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5756 -- If the bound is given by a discriminant, replace with a reference
5757 -- to the discriminant of the same name in the target task. If the
5758 -- entry name is the target of a requeue statement and the entry is
5759 -- in the current protected object, the bound to be used is the
5760 -- discriminal of the object (see apply_range_checks for details of
5761 -- the transformation).
5763 -----------------------------
5764 -- Actual_Discriminant_Ref --
5765 -----------------------------
5767 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5768 Typ : constant Entity_Id := Etype (Bound);
5772 Remove_Side_Effects (Bound);
5774 if not Is_Entity_Name (Bound)
5775 or else Ekind (Entity (Bound)) /= E_Discriminant
5779 elsif Is_Protected_Type (Tsk)
5780 and then In_Open_Scopes (Tsk)
5781 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5783 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5787 Make_Selected_Component (Loc,
5788 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5789 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5794 end Actual_Discriminant_Ref;
5796 -- Start of processing for Actual_Index_Type
5799 if not Has_Discriminants (Tsk)
5800 or else (not Is_Entity_Name (Lo)
5802 not Is_Entity_Name (Hi))
5804 return Entry_Index_Type (E);
5807 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5808 Set_Etype (New_T, Base_Type (Typ));
5809 Set_Size_Info (New_T, Typ);
5810 Set_RM_Size (New_T, RM_Size (Typ));
5811 Set_Scalar_Range (New_T,
5812 Make_Range (Sloc (Entry_Name),
5813 Low_Bound => Actual_Discriminant_Ref (Lo),
5814 High_Bound => Actual_Discriminant_Ref (Hi)));
5818 end Actual_Index_Type;
5820 -- Start of processing of Resolve_Entry
5823 -- Find name of entry being called, and resolve prefix of name
5824 -- with its own type. The prefix can be overloaded, and the name
5825 -- and signature of the entry must be taken into account.
5827 if Nkind (Entry_Name) = N_Indexed_Component then
5829 -- Case of dealing with entry family within the current tasks
5831 E_Name := Prefix (Entry_Name);
5834 E_Name := Entry_Name;
5837 if Is_Entity_Name (E_Name) then
5839 -- Entry call to an entry (or entry family) in the current task. This
5840 -- is legal even though the task will deadlock. Rewrite as call to
5843 -- This can also be a call to an entry in an enclosing task. If this
5844 -- is a single task, we have to retrieve its name, because the scope
5845 -- of the entry is the task type, not the object. If the enclosing
5846 -- task is a task type, the identity of the task is given by its own
5849 -- Finally this can be a requeue on an entry of the same task or
5850 -- protected object.
5852 S := Scope (Entity (E_Name));
5854 for J in reverse 0 .. Scope_Stack.Last loop
5855 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5856 and then not Comes_From_Source (S)
5858 -- S is an enclosing task or protected object. The concurrent
5859 -- declaration has been converted into a type declaration, and
5860 -- the object itself has an object declaration that follows
5861 -- the type in the same declarative part.
5863 Tsk := Next_Entity (S);
5864 while Etype (Tsk) /= S loop
5871 elsif S = Scope_Stack.Table (J).Entity then
5873 -- Call to current task. Will be transformed into call to Self
5881 Make_Selected_Component (Loc,
5882 Prefix => New_Occurrence_Of (S, Loc),
5884 New_Occurrence_Of (Entity (E_Name), Loc));
5885 Rewrite (E_Name, New_N);
5888 elsif Nkind (Entry_Name) = N_Selected_Component
5889 and then Is_Overloaded (Prefix (Entry_Name))
5891 -- Use the entry name (which must be unique at this point) to find
5892 -- the prefix that returns the corresponding task type or protected
5896 Pref : constant Node_Id := Prefix (Entry_Name);
5897 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5902 Get_First_Interp (Pref, I, It);
5903 while Present (It.Typ) loop
5904 if Scope (Ent) = It.Typ then
5905 Set_Etype (Pref, It.Typ);
5909 Get_Next_Interp (I, It);
5914 if Nkind (Entry_Name) = N_Selected_Component then
5915 Resolve (Prefix (Entry_Name));
5917 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5918 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5919 Resolve (Prefix (Prefix (Entry_Name)));
5920 Index := First (Expressions (Entry_Name));
5921 Resolve (Index, Entry_Index_Type (Nam));
5923 -- Up to this point the expression could have been the actual in a
5924 -- simple entry call, and be given by a named association.
5926 if Nkind (Index) = N_Parameter_Association then
5927 Error_Msg_N ("expect expression for entry index", Index);
5929 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5934 ------------------------
5935 -- Resolve_Entry_Call --
5936 ------------------------
5938 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5939 Entry_Name : constant Node_Id := Name (N);
5940 Loc : constant Source_Ptr := Sloc (Entry_Name);
5942 First_Named : Node_Id;
5949 -- We kill all checks here, because it does not seem worth the effort to
5950 -- do anything better, an entry call is a big operation.
5954 -- Processing of the name is similar for entry calls and protected
5955 -- operation calls. Once the entity is determined, we can complete
5956 -- the resolution of the actuals.
5958 -- The selector may be overloaded, in the case of a protected object
5959 -- with overloaded functions. The type of the context is used for
5962 if Nkind (Entry_Name) = N_Selected_Component
5963 and then Is_Overloaded (Selector_Name (Entry_Name))
5964 and then Typ /= Standard_Void_Type
5971 Get_First_Interp (Selector_Name (Entry_Name), I, It);
5972 while Present (It.Typ) loop
5973 if Covers (Typ, It.Typ) then
5974 Set_Entity (Selector_Name (Entry_Name), It.Nam);
5975 Set_Etype (Entry_Name, It.Typ);
5977 Generate_Reference (It.Typ, N, ' ');
5980 Get_Next_Interp (I, It);
5985 Resolve_Entry (Entry_Name);
5987 if Nkind (Entry_Name) = N_Selected_Component then
5989 -- Simple entry call
5991 Nam := Entity (Selector_Name (Entry_Name));
5992 Obj := Prefix (Entry_Name);
5993 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
5995 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5997 -- Call to member of entry family
5999 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6000 Obj := Prefix (Prefix (Entry_Name));
6001 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6004 -- We cannot in general check the maximum depth of protected entry
6005 -- calls at compile time. But we can tell that any protected entry
6006 -- call at all violates a specified nesting depth of zero.
6008 if Is_Protected_Type (Scope (Nam)) then
6009 Check_Restriction (Max_Entry_Queue_Length, N);
6012 -- Use context type to disambiguate a protected function that can be
6013 -- called without actuals and that returns an array type, and where
6014 -- the argument list may be an indexing of the returned value.
6016 if Ekind (Nam) = E_Function
6017 and then Needs_No_Actuals (Nam)
6018 and then Present (Parameter_Associations (N))
6020 ((Is_Array_Type (Etype (Nam))
6021 and then Covers (Typ, Component_Type (Etype (Nam))))
6023 or else (Is_Access_Type (Etype (Nam))
6024 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6025 and then Covers (Typ,
6026 Component_Type (Designated_Type (Etype (Nam))))))
6029 Index_Node : Node_Id;
6033 Make_Indexed_Component (Loc,
6035 Make_Function_Call (Loc,
6036 Name => Relocate_Node (Entry_Name)),
6037 Expressions => Parameter_Associations (N));
6039 -- Since we are correcting a node classification error made by
6040 -- the parser, we call Replace rather than Rewrite.
6042 Replace (N, Index_Node);
6043 Set_Etype (Prefix (N), Etype (Nam));
6045 Resolve_Indexed_Component (N, Typ);
6050 -- The operation name may have been overloaded. Order the actuals
6051 -- according to the formals of the resolved entity, and set the
6052 -- return type to that of the operation.
6055 Normalize_Actuals (N, Nam, False, Norm_OK);
6056 pragma Assert (Norm_OK);
6057 Set_Etype (N, Etype (Nam));
6060 Resolve_Actuals (N, Nam);
6061 Generate_Reference (Nam, Entry_Name);
6063 if Ekind (Nam) = E_Entry
6064 or else Ekind (Nam) = E_Entry_Family
6066 Check_Potentially_Blocking_Operation (N);
6069 -- Verify that a procedure call cannot masquerade as an entry
6070 -- call where an entry call is expected.
6072 if Ekind (Nam) = E_Procedure then
6073 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6074 and then N = Entry_Call_Statement (Parent (N))
6076 Error_Msg_N ("entry call required in select statement", N);
6078 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6079 and then N = Triggering_Statement (Parent (N))
6081 Error_Msg_N ("triggering statement cannot be procedure call", N);
6083 elsif Ekind (Scope (Nam)) = E_Task_Type
6084 and then not In_Open_Scopes (Scope (Nam))
6086 Error_Msg_N ("task has no entry with this name", Entry_Name);
6090 -- After resolution, entry calls and protected procedure calls are
6091 -- changed into entry calls, for expansion. The structure of the node
6092 -- does not change, so it can safely be done in place. Protected
6093 -- function calls must keep their structure because they are
6096 if Ekind (Nam) /= E_Function then
6098 -- A protected operation that is not a function may modify the
6099 -- corresponding object, and cannot apply to a constant. If this
6100 -- is an internal call, the prefix is the type itself.
6102 if Is_Protected_Type (Scope (Nam))
6103 and then not Is_Variable (Obj)
6104 and then (not Is_Entity_Name (Obj)
6105 or else not Is_Type (Entity (Obj)))
6108 ("prefix of protected procedure or entry call must be variable",
6112 Actuals := Parameter_Associations (N);
6113 First_Named := First_Named_Actual (N);
6116 Make_Entry_Call_Statement (Loc,
6118 Parameter_Associations => Actuals));
6120 Set_First_Named_Actual (N, First_Named);
6121 Set_Analyzed (N, True);
6123 -- Protected functions can return on the secondary stack, in which
6124 -- case we must trigger the transient scope mechanism.
6126 elsif Expander_Active
6127 and then Requires_Transient_Scope (Etype (Nam))
6129 Establish_Transient_Scope (N, Sec_Stack => True);
6131 end Resolve_Entry_Call;
6133 -------------------------
6134 -- Resolve_Equality_Op --
6135 -------------------------
6137 -- Both arguments must have the same type, and the boolean context does
6138 -- not participate in the resolution. The first pass verifies that the
6139 -- interpretation is not ambiguous, and the type of the left argument is
6140 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6141 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6142 -- though they carry a single (universal) type. Diagnose this case here.
6144 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6145 L : constant Node_Id := Left_Opnd (N);
6146 R : constant Node_Id := Right_Opnd (N);
6147 T : Entity_Id := Find_Unique_Type (L, R);
6149 function Find_Unique_Access_Type return Entity_Id;
6150 -- In the case of allocators, make a last-ditch attempt to find a single
6151 -- access type with the right designated type. This is semantically
6152 -- dubious, and of no interest to any real code, but c48008a makes it
6155 -----------------------------
6156 -- Find_Unique_Access_Type --
6157 -----------------------------
6159 function Find_Unique_Access_Type return Entity_Id is
6165 if Ekind (Etype (R)) = E_Allocator_Type then
6166 Acc := Designated_Type (Etype (R));
6167 elsif Ekind (Etype (L)) = E_Allocator_Type then
6168 Acc := Designated_Type (Etype (L));
6174 while S /= Standard_Standard loop
6175 E := First_Entity (S);
6176 while Present (E) loop
6178 and then Is_Access_Type (E)
6179 and then Ekind (E) /= E_Allocator_Type
6180 and then Designated_Type (E) = Base_Type (Acc)
6192 end Find_Unique_Access_Type;
6194 -- Start of processing for Resolve_Equality_Op
6197 Check_No_Direct_Boolean_Operators (N);
6199 Set_Etype (N, Base_Type (Typ));
6200 Generate_Reference (T, N, ' ');
6202 if T = Any_Fixed then
6203 T := Unique_Fixed_Point_Type (L);
6206 if T /= Any_Type then
6208 or else T = Any_Composite
6209 or else T = Any_Character
6211 if T = Any_Character then
6212 Ambiguous_Character (L);
6214 Error_Msg_N ("ambiguous operands for equality", N);
6217 Set_Etype (N, Any_Type);
6220 elsif T = Any_Access
6221 or else Ekind (T) = E_Allocator_Type
6222 or else Ekind (T) = E_Access_Attribute_Type
6224 T := Find_Unique_Access_Type;
6227 Error_Msg_N ("ambiguous operands for equality", N);
6228 Set_Etype (N, Any_Type);
6236 -- If the unique type is a class-wide type then it will be expanded
6237 -- into a dispatching call to the predefined primitive. Therefore we
6238 -- check here for potential violation of such restriction.
6240 if Is_Class_Wide_Type (T) then
6241 Check_Restriction (No_Dispatching_Calls, N);
6244 if Warn_On_Redundant_Constructs
6245 and then Comes_From_Source (N)
6246 and then Is_Entity_Name (R)
6247 and then Entity (R) = Standard_True
6248 and then Comes_From_Source (R)
6250 Error_Msg_N ("?comparison with True is redundant!", R);
6253 Check_Unset_Reference (L);
6254 Check_Unset_Reference (R);
6255 Generate_Operator_Reference (N, T);
6256 Check_Low_Bound_Tested (N);
6258 -- If this is an inequality, it may be the implicit inequality
6259 -- created for a user-defined operation, in which case the corres-
6260 -- ponding equality operation is not intrinsic, and the operation
6261 -- cannot be constant-folded. Else fold.
6263 if Nkind (N) = N_Op_Eq
6264 or else Comes_From_Source (Entity (N))
6265 or else Ekind (Entity (N)) = E_Operator
6266 or else Is_Intrinsic_Subprogram
6267 (Corresponding_Equality (Entity (N)))
6269 Eval_Relational_Op (N);
6271 elsif Nkind (N) = N_Op_Ne
6272 and then Is_Abstract_Subprogram (Entity (N))
6274 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6277 -- Ada 2005: If one operand is an anonymous access type, convert the
6278 -- other operand to it, to ensure that the underlying types match in
6279 -- the back-end. Same for access_to_subprogram, and the conversion
6280 -- verifies that the types are subtype conformant.
6282 -- We apply the same conversion in the case one of the operands is a
6283 -- private subtype of the type of the other.
6285 -- Why the Expander_Active test here ???
6289 (Ekind (T) = E_Anonymous_Access_Type
6290 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6291 or else Is_Private_Type (T))
6293 if Etype (L) /= T then
6295 Make_Unchecked_Type_Conversion (Sloc (L),
6296 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6297 Expression => Relocate_Node (L)));
6298 Analyze_And_Resolve (L, T);
6301 if (Etype (R)) /= T then
6303 Make_Unchecked_Type_Conversion (Sloc (R),
6304 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6305 Expression => Relocate_Node (R)));
6306 Analyze_And_Resolve (R, T);
6310 end Resolve_Equality_Op;
6312 ----------------------------------
6313 -- Resolve_Explicit_Dereference --
6314 ----------------------------------
6316 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6317 Loc : constant Source_Ptr := Sloc (N);
6319 P : constant Node_Id := Prefix (N);
6324 Check_Fully_Declared_Prefix (Typ, P);
6326 if Is_Overloaded (P) then
6328 -- Use the context type to select the prefix that has the correct
6331 Get_First_Interp (P, I, It);
6332 while Present (It.Typ) loop
6333 exit when Is_Access_Type (It.Typ)
6334 and then Covers (Typ, Designated_Type (It.Typ));
6335 Get_Next_Interp (I, It);
6338 if Present (It.Typ) then
6339 Resolve (P, It.Typ);
6341 -- If no interpretation covers the designated type of the prefix,
6342 -- this is the pathological case where not all implementations of
6343 -- the prefix allow the interpretation of the node as a call. Now
6344 -- that the expected type is known, Remove other interpretations
6345 -- from prefix, rewrite it as a call, and resolve again, so that
6346 -- the proper call node is generated.
6348 Get_First_Interp (P, I, It);
6349 while Present (It.Typ) loop
6350 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6354 Get_Next_Interp (I, It);
6358 Make_Function_Call (Loc,
6360 Make_Explicit_Dereference (Loc,
6362 Parameter_Associations => New_List);
6364 Save_Interps (N, New_N);
6366 Analyze_And_Resolve (N, Typ);
6370 Set_Etype (N, Designated_Type (It.Typ));
6376 if Is_Access_Type (Etype (P)) then
6377 Apply_Access_Check (N);
6380 -- If the designated type is a packed unconstrained array type, and the
6381 -- explicit dereference is not in the context of an attribute reference,
6382 -- then we must compute and set the actual subtype, since it is needed
6383 -- by Gigi. The reason we exclude the attribute case is that this is
6384 -- handled fine by Gigi, and in fact we use such attributes to build the
6385 -- actual subtype. We also exclude generated code (which builds actual
6386 -- subtypes directly if they are needed).
6388 if Is_Array_Type (Etype (N))
6389 and then Is_Packed (Etype (N))
6390 and then not Is_Constrained (Etype (N))
6391 and then Nkind (Parent (N)) /= N_Attribute_Reference
6392 and then Comes_From_Source (N)
6394 Set_Etype (N, Get_Actual_Subtype (N));
6397 -- Note: there is no Eval processing required for an explicit deference,
6398 -- because the type is known to be an allocators, and allocator
6399 -- expressions can never be static.
6401 end Resolve_Explicit_Dereference;
6403 -------------------------------
6404 -- Resolve_Indexed_Component --
6405 -------------------------------
6407 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6408 Name : constant Node_Id := Prefix (N);
6410 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6414 if Is_Overloaded (Name) then
6416 -- Use the context type to select the prefix that yields the correct
6422 I1 : Interp_Index := 0;
6423 P : constant Node_Id := Prefix (N);
6424 Found : Boolean := False;
6427 Get_First_Interp (P, I, It);
6428 while Present (It.Typ) loop
6429 if (Is_Array_Type (It.Typ)
6430 and then Covers (Typ, Component_Type (It.Typ)))
6431 or else (Is_Access_Type (It.Typ)
6432 and then Is_Array_Type (Designated_Type (It.Typ))
6434 (Typ, Component_Type (Designated_Type (It.Typ))))
6437 It := Disambiguate (P, I1, I, Any_Type);
6439 if It = No_Interp then
6440 Error_Msg_N ("ambiguous prefix for indexing", N);
6446 Array_Type := It.Typ;
6452 Array_Type := It.Typ;
6457 Get_Next_Interp (I, It);
6462 Array_Type := Etype (Name);
6465 Resolve (Name, Array_Type);
6466 Array_Type := Get_Actual_Subtype_If_Available (Name);
6468 -- If prefix is access type, dereference to get real array type.
6469 -- Note: we do not apply an access check because the expander always
6470 -- introduces an explicit dereference, and the check will happen there.
6472 if Is_Access_Type (Array_Type) then
6473 Array_Type := Designated_Type (Array_Type);
6476 -- If name was overloaded, set component type correctly now
6477 -- If a misplaced call to an entry family (which has no index types)
6478 -- return. Error will be diagnosed from calling context.
6480 if Is_Array_Type (Array_Type) then
6481 Set_Etype (N, Component_Type (Array_Type));
6486 Index := First_Index (Array_Type);
6487 Expr := First (Expressions (N));
6489 -- The prefix may have resolved to a string literal, in which case its
6490 -- etype has a special representation. This is only possible currently
6491 -- if the prefix is a static concatenation, written in functional
6494 if Ekind (Array_Type) = E_String_Literal_Subtype then
6495 Resolve (Expr, Standard_Positive);
6498 while Present (Index) and Present (Expr) loop
6499 Resolve (Expr, Etype (Index));
6500 Check_Unset_Reference (Expr);
6502 if Is_Scalar_Type (Etype (Expr)) then
6503 Apply_Scalar_Range_Check (Expr, Etype (Index));
6505 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6513 -- Do not generate the warning on suspicious index if we are analyzing
6514 -- package Ada.Tags; otherwise we will report the warning with the
6515 -- Prims_Ptr field of the dispatch table.
6517 if Scope (Etype (Prefix (N))) = Standard_Standard
6519 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6522 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6523 Eval_Indexed_Component (N);
6525 end Resolve_Indexed_Component;
6527 -----------------------------
6528 -- Resolve_Integer_Literal --
6529 -----------------------------
6531 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6534 Eval_Integer_Literal (N);
6535 end Resolve_Integer_Literal;
6537 --------------------------------
6538 -- Resolve_Intrinsic_Operator --
6539 --------------------------------
6541 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6542 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6549 while Scope (Op) /= Standard_Standard loop
6551 pragma Assert (Present (Op));
6555 Set_Is_Overloaded (N, False);
6557 -- If the operand type is private, rewrite with suitable conversions on
6558 -- the operands and the result, to expose the proper underlying numeric
6561 if Is_Private_Type (Typ) then
6562 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6564 if Nkind (N) = N_Op_Expon then
6565 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6567 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6570 Save_Interps (Left_Opnd (N), Expression (Arg1));
6571 Save_Interps (Right_Opnd (N), Expression (Arg2));
6573 Set_Left_Opnd (N, Arg1);
6574 Set_Right_Opnd (N, Arg2);
6576 Set_Etype (N, Btyp);
6577 Rewrite (N, Unchecked_Convert_To (Typ, N));
6580 elsif Typ /= Etype (Left_Opnd (N))
6581 or else Typ /= Etype (Right_Opnd (N))
6583 -- Add explicit conversion where needed, and save interpretations in
6584 -- case operands are overloaded.
6586 Arg1 := Convert_To (Typ, Left_Opnd (N));
6587 Arg2 := Convert_To (Typ, Right_Opnd (N));
6589 if Nkind (Arg1) = N_Type_Conversion then
6590 Save_Interps (Left_Opnd (N), Expression (Arg1));
6592 Save_Interps (Left_Opnd (N), Arg1);
6595 if Nkind (Arg2) = N_Type_Conversion then
6596 Save_Interps (Right_Opnd (N), Expression (Arg2));
6598 Save_Interps (Right_Opnd (N), Arg2);
6601 Rewrite (Left_Opnd (N), Arg1);
6602 Rewrite (Right_Opnd (N), Arg2);
6605 Resolve_Arithmetic_Op (N, Typ);
6608 Resolve_Arithmetic_Op (N, Typ);
6610 end Resolve_Intrinsic_Operator;
6612 --------------------------------------
6613 -- Resolve_Intrinsic_Unary_Operator --
6614 --------------------------------------
6616 procedure Resolve_Intrinsic_Unary_Operator
6620 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6626 while Scope (Op) /= Standard_Standard loop
6628 pragma Assert (Present (Op));
6633 if Is_Private_Type (Typ) then
6634 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6635 Save_Interps (Right_Opnd (N), Expression (Arg2));
6637 Set_Right_Opnd (N, Arg2);
6639 Set_Etype (N, Btyp);
6640 Rewrite (N, Unchecked_Convert_To (Typ, N));
6644 Resolve_Unary_Op (N, Typ);
6646 end Resolve_Intrinsic_Unary_Operator;
6648 ------------------------
6649 -- Resolve_Logical_Op --
6650 ------------------------
6652 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6656 Check_No_Direct_Boolean_Operators (N);
6658 -- Predefined operations on scalar types yield the base type. On the
6659 -- other hand, logical operations on arrays yield the type of the
6660 -- arguments (and the context).
6662 if Is_Array_Type (Typ) then
6665 B_Typ := Base_Type (Typ);
6668 -- The following test is required because the operands of the operation
6669 -- may be literals, in which case the resulting type appears to be
6670 -- compatible with a signed integer type, when in fact it is compatible
6671 -- only with modular types. If the context itself is universal, the
6672 -- operation is illegal.
6674 if not Valid_Boolean_Arg (Typ) then
6675 Error_Msg_N ("invalid context for logical operation", N);
6676 Set_Etype (N, Any_Type);
6679 elsif Typ = Any_Modular then
6681 ("no modular type available in this context", N);
6682 Set_Etype (N, Any_Type);
6684 elsif Is_Modular_Integer_Type (Typ)
6685 and then Etype (Left_Opnd (N)) = Universal_Integer
6686 and then Etype (Right_Opnd (N)) = Universal_Integer
6688 Check_For_Visible_Operator (N, B_Typ);
6691 Resolve (Left_Opnd (N), B_Typ);
6692 Resolve (Right_Opnd (N), B_Typ);
6694 Check_Unset_Reference (Left_Opnd (N));
6695 Check_Unset_Reference (Right_Opnd (N));
6697 Set_Etype (N, B_Typ);
6698 Generate_Operator_Reference (N, B_Typ);
6699 Eval_Logical_Op (N);
6700 end Resolve_Logical_Op;
6702 ---------------------------
6703 -- Resolve_Membership_Op --
6704 ---------------------------
6706 -- The context can only be a boolean type, and does not determine
6707 -- the arguments. Arguments should be unambiguous, but the preference
6708 -- rule for universal types applies.
6710 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6711 pragma Warnings (Off, Typ);
6713 L : constant Node_Id := Left_Opnd (N);
6714 R : constant Node_Id := Right_Opnd (N);
6718 if L = Error or else R = Error then
6722 if not Is_Overloaded (R)
6724 (Etype (R) = Universal_Integer or else
6725 Etype (R) = Universal_Real)
6726 and then Is_Overloaded (L)
6730 -- Ada 2005 (AI-251): Support the following case:
6732 -- type I is interface;
6733 -- type T is tagged ...
6735 -- function Test (O : I'Class) is
6737 -- return O in T'Class.
6740 -- In this case we have nothing else to do. The membership test will be
6741 -- done at run-time.
6743 elsif Ada_Version >= Ada_05
6744 and then Is_Class_Wide_Type (Etype (L))
6745 and then Is_Interface (Etype (L))
6746 and then Is_Class_Wide_Type (Etype (R))
6747 and then not Is_Interface (Etype (R))
6752 T := Intersect_Types (L, R);
6756 Check_Unset_Reference (L);
6758 if Nkind (R) = N_Range
6759 and then not Is_Scalar_Type (T)
6761 Error_Msg_N ("scalar type required for range", R);
6764 if Is_Entity_Name (R) then
6765 Freeze_Expression (R);
6768 Check_Unset_Reference (R);
6771 Eval_Membership_Op (N);
6772 end Resolve_Membership_Op;
6778 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6779 Loc : constant Source_Ptr := Sloc (N);
6782 -- Handle restriction against anonymous null access values This
6783 -- restriction can be turned off using -gnatdj.
6785 -- Ada 2005 (AI-231): Remove restriction
6787 if Ada_Version < Ada_05
6788 and then not Debug_Flag_J
6789 and then Ekind (Typ) = E_Anonymous_Access_Type
6790 and then Comes_From_Source (N)
6792 -- In the common case of a call which uses an explicitly null value
6793 -- for an access parameter, give specialized error message.
6795 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6799 ("null is not allowed as argument for an access parameter", N);
6801 -- Standard message for all other cases (are there any?)
6805 ("null cannot be of an anonymous access type", N);
6809 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6810 -- assignment to a null-excluding object
6812 if Ada_Version >= Ada_05
6813 and then Can_Never_Be_Null (Typ)
6814 and then Nkind (Parent (N)) = N_Assignment_Statement
6816 if not Inside_Init_Proc then
6818 (Compile_Time_Constraint_Error (N,
6819 "(Ada 2005) null not allowed in null-excluding objects?"),
6820 Make_Raise_Constraint_Error (Loc,
6821 Reason => CE_Access_Check_Failed));
6824 Make_Raise_Constraint_Error (Loc,
6825 Reason => CE_Access_Check_Failed));
6829 -- In a distributed context, null for a remote access to subprogram may
6830 -- need to be replaced with a special record aggregate. In this case,
6831 -- return after having done the transformation.
6833 if (Ekind (Typ) = E_Record_Type
6834 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6835 and then Remote_AST_Null_Value (N, Typ)
6840 -- The null literal takes its type from the context
6845 -----------------------
6846 -- Resolve_Op_Concat --
6847 -----------------------
6849 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6851 -- We wish to avoid deep recursion, because concatenations are often
6852 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6853 -- operands nonrecursively until we find something that is not a simple
6854 -- concatenation (A in this case). We resolve that, and then walk back
6855 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6856 -- to do the rest of the work at each level. The Parent pointers allow
6857 -- us to avoid recursion, and thus avoid running out of memory. See also
6858 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6864 -- The following code is equivalent to:
6866 -- Resolve_Op_Concat_First (NN, Typ);
6867 -- Resolve_Op_Concat_Arg (N, ...);
6868 -- Resolve_Op_Concat_Rest (N, Typ);
6870 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6871 -- operand is a concatenation.
6873 -- Walk down left operands
6876 Resolve_Op_Concat_First (NN, Typ);
6877 Op1 := Left_Opnd (NN);
6878 exit when not (Nkind (Op1) = N_Op_Concat
6879 and then not Is_Array_Type (Component_Type (Typ))
6880 and then Entity (Op1) = Entity (NN));
6884 -- Now (given the above example) NN is A&B and Op1 is A
6886 -- First resolve Op1 ...
6888 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6890 -- ... then walk NN back up until we reach N (where we started), calling
6891 -- Resolve_Op_Concat_Rest along the way.
6894 Resolve_Op_Concat_Rest (NN, Typ);
6898 end Resolve_Op_Concat;
6900 ---------------------------
6901 -- Resolve_Op_Concat_Arg --
6902 ---------------------------
6904 procedure Resolve_Op_Concat_Arg
6910 Btyp : constant Entity_Id := Base_Type (Typ);
6915 or else (not Is_Overloaded (Arg)
6916 and then Etype (Arg) /= Any_Composite
6917 and then Covers (Component_Type (Typ), Etype (Arg)))
6919 Resolve (Arg, Component_Type (Typ));
6921 Resolve (Arg, Btyp);
6924 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6925 if Nkind (Arg) = N_Aggregate
6926 and then Is_Composite_Type (Component_Type (Typ))
6928 if Is_Private_Type (Component_Type (Typ)) then
6929 Resolve (Arg, Btyp);
6931 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6932 Set_Etype (Arg, Any_Type);
6936 if Is_Overloaded (Arg)
6937 and then Has_Compatible_Type (Arg, Typ)
6938 and then Etype (Arg) /= Any_Type
6946 Get_First_Interp (Arg, I, It);
6948 Get_Next_Interp (I, It);
6950 -- Special-case the error message when the overloading is
6951 -- caused by a function that yields an array and can be
6952 -- called without parameters.
6954 if It.Nam = Func then
6955 Error_Msg_Sloc := Sloc (Func);
6956 Error_Msg_N ("ambiguous call to function#", Arg);
6958 ("\\interpretation as call yields&", Arg, Typ);
6960 ("\\interpretation as indexing of call yields&",
6961 Arg, Component_Type (Typ));
6965 ("ambiguous operand for concatenation!", Arg);
6966 Get_First_Interp (Arg, I, It);
6967 while Present (It.Nam) loop
6968 Error_Msg_Sloc := Sloc (It.Nam);
6970 if Base_Type (It.Typ) = Base_Type (Typ)
6971 or else Base_Type (It.Typ) =
6972 Base_Type (Component_Type (Typ))
6974 Error_Msg_N -- CODEFIX
6975 ("\\possible interpretation#", Arg);
6978 Get_Next_Interp (I, It);
6984 Resolve (Arg, Component_Type (Typ));
6986 if Nkind (Arg) = N_String_Literal then
6987 Set_Etype (Arg, Component_Type (Typ));
6990 if Arg = Left_Opnd (N) then
6991 Set_Is_Component_Left_Opnd (N);
6993 Set_Is_Component_Right_Opnd (N);
6998 Resolve (Arg, Btyp);
7001 Check_Unset_Reference (Arg);
7002 end Resolve_Op_Concat_Arg;
7004 -----------------------------
7005 -- Resolve_Op_Concat_First --
7006 -----------------------------
7008 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7009 Btyp : constant Entity_Id := Base_Type (Typ);
7010 Op1 : constant Node_Id := Left_Opnd (N);
7011 Op2 : constant Node_Id := Right_Opnd (N);
7014 -- The parser folds an enormous sequence of concatenations of string
7015 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7016 -- in the right operand. If the expression resolves to a predefined "&"
7017 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7018 -- we give an error. See P_Simple_Expression in Par.Ch4.
7020 if Nkind (Op2) = N_String_Literal
7021 and then Is_Folded_In_Parser (Op2)
7022 and then Ekind (Entity (N)) = E_Function
7024 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7025 and then String_Length (Strval (Op1)) = 0);
7026 Error_Msg_N ("too many user-defined concatenations", N);
7030 Set_Etype (N, Btyp);
7032 if Is_Limited_Composite (Btyp) then
7033 Error_Msg_N ("concatenation not available for limited array", N);
7034 Explain_Limited_Type (Btyp, N);
7036 end Resolve_Op_Concat_First;
7038 ----------------------------
7039 -- Resolve_Op_Concat_Rest --
7040 ----------------------------
7042 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7043 Op1 : constant Node_Id := Left_Opnd (N);
7044 Op2 : constant Node_Id := Right_Opnd (N);
7047 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7049 Generate_Operator_Reference (N, Typ);
7051 if Is_String_Type (Typ) then
7052 Eval_Concatenation (N);
7055 -- If this is not a static concatenation, but the result is a string
7056 -- type (and not an array of strings) ensure that static string operands
7057 -- have their subtypes properly constructed.
7059 if Nkind (N) /= N_String_Literal
7060 and then Is_Character_Type (Component_Type (Typ))
7062 Set_String_Literal_Subtype (Op1, Typ);
7063 Set_String_Literal_Subtype (Op2, Typ);
7065 end Resolve_Op_Concat_Rest;
7067 ----------------------
7068 -- Resolve_Op_Expon --
7069 ----------------------
7071 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7072 B_Typ : constant Entity_Id := Base_Type (Typ);
7075 -- Catch attempts to do fixed-point exponentiation with universal
7076 -- operands, which is a case where the illegality is not caught during
7077 -- normal operator analysis.
7079 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7080 Error_Msg_N ("exponentiation not available for fixed point", N);
7084 if Comes_From_Source (N)
7085 and then Ekind (Entity (N)) = E_Function
7086 and then Is_Imported (Entity (N))
7087 and then Is_Intrinsic_Subprogram (Entity (N))
7089 Resolve_Intrinsic_Operator (N, Typ);
7093 if Etype (Left_Opnd (N)) = Universal_Integer
7094 or else Etype (Left_Opnd (N)) = Universal_Real
7096 Check_For_Visible_Operator (N, B_Typ);
7099 -- We do the resolution using the base type, because intermediate values
7100 -- in expressions always are of the base type, not a subtype of it.
7102 Resolve (Left_Opnd (N), B_Typ);
7103 Resolve (Right_Opnd (N), Standard_Integer);
7105 Check_Unset_Reference (Left_Opnd (N));
7106 Check_Unset_Reference (Right_Opnd (N));
7108 Set_Etype (N, B_Typ);
7109 Generate_Operator_Reference (N, B_Typ);
7112 -- Set overflow checking bit. Much cleverer code needed here eventually
7113 -- and perhaps the Resolve routines should be separated for the various
7114 -- arithmetic operations, since they will need different processing. ???
7116 if Nkind (N) in N_Op then
7117 if not Overflow_Checks_Suppressed (Etype (N)) then
7118 Enable_Overflow_Check (N);
7121 end Resolve_Op_Expon;
7123 --------------------
7124 -- Resolve_Op_Not --
7125 --------------------
7127 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7130 function Parent_Is_Boolean return Boolean;
7131 -- This function determines if the parent node is a boolean operator
7132 -- or operation (comparison op, membership test, or short circuit form)
7133 -- and the not in question is the left operand of this operation.
7134 -- Note that if the not is in parens, then false is returned.
7136 -----------------------
7137 -- Parent_Is_Boolean --
7138 -----------------------
7140 function Parent_Is_Boolean return Boolean is
7142 if Paren_Count (N) /= 0 then
7146 case Nkind (Parent (N)) is
7161 return Left_Opnd (Parent (N)) = N;
7167 end Parent_Is_Boolean;
7169 -- Start of processing for Resolve_Op_Not
7172 -- Predefined operations on scalar types yield the base type. On the
7173 -- other hand, logical operations on arrays yield the type of the
7174 -- arguments (and the context).
7176 if Is_Array_Type (Typ) then
7179 B_Typ := Base_Type (Typ);
7182 -- Straightforward case of incorrect arguments
7184 if not Valid_Boolean_Arg (Typ) then
7185 Error_Msg_N ("invalid operand type for operator&", N);
7186 Set_Etype (N, Any_Type);
7189 -- Special case of probable missing parens
7191 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7192 if Parent_Is_Boolean then
7194 ("operand of not must be enclosed in parentheses",
7198 ("no modular type available in this context", N);
7201 Set_Etype (N, Any_Type);
7204 -- OK resolution of not
7207 -- Warn if non-boolean types involved. This is a case like not a < b
7208 -- where a and b are modular, where we will get (not a) < b and most
7209 -- likely not (a < b) was intended.
7211 if Warn_On_Questionable_Missing_Parens
7212 and then not Is_Boolean_Type (Typ)
7213 and then Parent_Is_Boolean
7215 Error_Msg_N ("?not expression should be parenthesized here!", N);
7218 -- Warn on double negation if checking redundant constructs
7220 if Warn_On_Redundant_Constructs
7221 and then Comes_From_Source (N)
7222 and then Comes_From_Source (Right_Opnd (N))
7223 and then Root_Type (Typ) = Standard_Boolean
7224 and then Nkind (Right_Opnd (N)) = N_Op_Not
7226 Error_Msg_N ("redundant double negation?", N);
7229 -- Complete resolution and evaluation of NOT
7231 Resolve (Right_Opnd (N), B_Typ);
7232 Check_Unset_Reference (Right_Opnd (N));
7233 Set_Etype (N, B_Typ);
7234 Generate_Operator_Reference (N, B_Typ);
7239 -----------------------------
7240 -- Resolve_Operator_Symbol --
7241 -----------------------------
7243 -- Nothing to be done, all resolved already
7245 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7246 pragma Warnings (Off, N);
7247 pragma Warnings (Off, Typ);
7251 end Resolve_Operator_Symbol;
7253 ----------------------------------
7254 -- Resolve_Qualified_Expression --
7255 ----------------------------------
7257 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7258 pragma Warnings (Off, Typ);
7260 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7261 Expr : constant Node_Id := Expression (N);
7264 Resolve (Expr, Target_Typ);
7266 -- A qualified expression requires an exact match of the type,
7267 -- class-wide matching is not allowed. However, if the qualifying
7268 -- type is specific and the expression has a class-wide type, it
7269 -- may still be okay, since it can be the result of the expansion
7270 -- of a call to a dispatching function, so we also have to check
7271 -- class-wideness of the type of the expression's original node.
7273 if (Is_Class_Wide_Type (Target_Typ)
7275 (Is_Class_Wide_Type (Etype (Expr))
7276 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7277 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7279 Wrong_Type (Expr, Target_Typ);
7282 -- If the target type is unconstrained, then we reset the type of
7283 -- the result from the type of the expression. For other cases, the
7284 -- actual subtype of the expression is the target type.
7286 if Is_Composite_Type (Target_Typ)
7287 and then not Is_Constrained (Target_Typ)
7289 Set_Etype (N, Etype (Expr));
7292 Eval_Qualified_Expression (N);
7293 end Resolve_Qualified_Expression;
7299 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7300 L : constant Node_Id := Low_Bound (N);
7301 H : constant Node_Id := High_Bound (N);
7308 Check_Unset_Reference (L);
7309 Check_Unset_Reference (H);
7311 -- We have to check the bounds for being within the base range as
7312 -- required for a non-static context. Normally this is automatic and
7313 -- done as part of evaluating expressions, but the N_Range node is an
7314 -- exception, since in GNAT we consider this node to be a subexpression,
7315 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7316 -- this, but that would put the test on the main evaluation path for
7319 Check_Non_Static_Context (L);
7320 Check_Non_Static_Context (H);
7322 -- Check for an ambiguous range over character literals. This will
7323 -- happen with a membership test involving only literals.
7325 if Typ = Any_Character then
7326 Ambiguous_Character (L);
7327 Set_Etype (N, Any_Type);
7331 -- If bounds are static, constant-fold them, so size computations
7332 -- are identical between front-end and back-end. Do not perform this
7333 -- transformation while analyzing generic units, as type information
7334 -- would then be lost when reanalyzing the constant node in the
7337 if Is_Discrete_Type (Typ) and then Expander_Active then
7338 if Is_OK_Static_Expression (L) then
7339 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7342 if Is_OK_Static_Expression (H) then
7343 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7348 --------------------------
7349 -- Resolve_Real_Literal --
7350 --------------------------
7352 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7353 Actual_Typ : constant Entity_Id := Etype (N);
7356 -- Special processing for fixed-point literals to make sure that the
7357 -- value is an exact multiple of small where this is required. We
7358 -- skip this for the universal real case, and also for generic types.
7360 if Is_Fixed_Point_Type (Typ)
7361 and then Typ /= Universal_Fixed
7362 and then Typ /= Any_Fixed
7363 and then not Is_Generic_Type (Typ)
7366 Val : constant Ureal := Realval (N);
7367 Cintr : constant Ureal := Val / Small_Value (Typ);
7368 Cint : constant Uint := UR_Trunc (Cintr);
7369 Den : constant Uint := Norm_Den (Cintr);
7373 -- Case of literal is not an exact multiple of the Small
7377 -- For a source program literal for a decimal fixed-point
7378 -- type, this is statically illegal (RM 4.9(36)).
7380 if Is_Decimal_Fixed_Point_Type (Typ)
7381 and then Actual_Typ = Universal_Real
7382 and then Comes_From_Source (N)
7384 Error_Msg_N ("value has extraneous low order digits", N);
7387 -- Generate a warning if literal from source
7389 if Is_Static_Expression (N)
7390 and then Warn_On_Bad_Fixed_Value
7393 ("?static fixed-point value is not a multiple of Small!",
7397 -- Replace literal by a value that is the exact representation
7398 -- of a value of the type, i.e. a multiple of the small value,
7399 -- by truncation, since Machine_Rounds is false for all GNAT
7400 -- fixed-point types (RM 4.9(38)).
7402 Stat := Is_Static_Expression (N);
7404 Make_Real_Literal (Sloc (N),
7405 Realval => Small_Value (Typ) * Cint));
7407 Set_Is_Static_Expression (N, Stat);
7410 -- In all cases, set the corresponding integer field
7412 Set_Corresponding_Integer_Value (N, Cint);
7416 -- Now replace the actual type by the expected type as usual
7419 Eval_Real_Literal (N);
7420 end Resolve_Real_Literal;
7422 -----------------------
7423 -- Resolve_Reference --
7424 -----------------------
7426 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7427 P : constant Node_Id := Prefix (N);
7430 -- Replace general access with specific type
7432 if Ekind (Etype (N)) = E_Allocator_Type then
7433 Set_Etype (N, Base_Type (Typ));
7436 Resolve (P, Designated_Type (Etype (N)));
7438 -- If we are taking the reference of a volatile entity, then treat
7439 -- it as a potential modification of this entity. This is much too
7440 -- conservative, but is necessary because remove side effects can
7441 -- result in transformations of normal assignments into reference
7442 -- sequences that otherwise fail to notice the modification.
7444 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7445 Note_Possible_Modification (P, Sure => False);
7447 end Resolve_Reference;
7449 --------------------------------
7450 -- Resolve_Selected_Component --
7451 --------------------------------
7453 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7455 Comp1 : Entity_Id := Empty; -- prevent junk warning
7456 P : constant Node_Id := Prefix (N);
7457 S : constant Node_Id := Selector_Name (N);
7458 T : Entity_Id := Etype (P);
7460 I1 : Interp_Index := 0; -- prevent junk warning
7465 function Init_Component return Boolean;
7466 -- Check whether this is the initialization of a component within an
7467 -- init proc (by assignment or call to another init proc). If true,
7468 -- there is no need for a discriminant check.
7470 --------------------
7471 -- Init_Component --
7472 --------------------
7474 function Init_Component return Boolean is
7476 return Inside_Init_Proc
7477 and then Nkind (Prefix (N)) = N_Identifier
7478 and then Chars (Prefix (N)) = Name_uInit
7479 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7482 -- Start of processing for Resolve_Selected_Component
7485 if Is_Overloaded (P) then
7487 -- Use the context type to select the prefix that has a selector
7488 -- of the correct name and type.
7491 Get_First_Interp (P, I, It);
7493 Search : while Present (It.Typ) loop
7494 if Is_Access_Type (It.Typ) then
7495 T := Designated_Type (It.Typ);
7500 if Is_Record_Type (T) then
7502 -- The visible components of a class-wide type are those of
7505 if Is_Class_Wide_Type (T) then
7509 Comp := First_Entity (T);
7510 while Present (Comp) loop
7511 if Chars (Comp) = Chars (S)
7512 and then Covers (Etype (Comp), Typ)
7521 It := Disambiguate (P, I1, I, Any_Type);
7523 if It = No_Interp then
7525 ("ambiguous prefix for selected component", N);
7532 -- There may be an implicit dereference. Retrieve
7533 -- designated record type.
7535 if Is_Access_Type (It1.Typ) then
7536 T := Designated_Type (It1.Typ);
7541 if Scope (Comp1) /= T then
7543 -- Resolution chooses the new interpretation.
7544 -- Find the component with the right name.
7546 Comp1 := First_Entity (T);
7547 while Present (Comp1)
7548 and then Chars (Comp1) /= Chars (S)
7550 Comp1 := Next_Entity (Comp1);
7559 Comp := Next_Entity (Comp);
7564 Get_Next_Interp (I, It);
7567 Resolve (P, It1.Typ);
7569 Set_Entity_With_Style_Check (S, Comp1);
7572 -- Resolve prefix with its type
7577 -- Generate cross-reference. We needed to wait until full overloading
7578 -- resolution was complete to do this, since otherwise we can't tell if
7579 -- we are an Lvalue of not.
7581 if May_Be_Lvalue (N) then
7582 Generate_Reference (Entity (S), S, 'm');
7584 Generate_Reference (Entity (S), S, 'r');
7587 -- If prefix is an access type, the node will be transformed into an
7588 -- explicit dereference during expansion. The type of the node is the
7589 -- designated type of that of the prefix.
7591 if Is_Access_Type (Etype (P)) then
7592 T := Designated_Type (Etype (P));
7593 Check_Fully_Declared_Prefix (T, P);
7598 if Has_Discriminants (T)
7599 and then (Ekind (Entity (S)) = E_Component
7601 Ekind (Entity (S)) = E_Discriminant)
7602 and then Present (Original_Record_Component (Entity (S)))
7603 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7604 and then Present (Discriminant_Checking_Func
7605 (Original_Record_Component (Entity (S))))
7606 and then not Discriminant_Checks_Suppressed (T)
7607 and then not Init_Component
7609 Set_Do_Discriminant_Check (N);
7612 if Ekind (Entity (S)) = E_Void then
7613 Error_Msg_N ("premature use of component", S);
7616 -- If the prefix is a record conversion, this may be a renamed
7617 -- discriminant whose bounds differ from those of the original
7618 -- one, so we must ensure that a range check is performed.
7620 if Nkind (P) = N_Type_Conversion
7621 and then Ekind (Entity (S)) = E_Discriminant
7622 and then Is_Discrete_Type (Typ)
7624 Set_Etype (N, Base_Type (Typ));
7627 -- Note: No Eval processing is required, because the prefix is of a
7628 -- record type, or protected type, and neither can possibly be static.
7630 end Resolve_Selected_Component;
7636 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7637 B_Typ : constant Entity_Id := Base_Type (Typ);
7638 L : constant Node_Id := Left_Opnd (N);
7639 R : constant Node_Id := Right_Opnd (N);
7642 -- We do the resolution using the base type, because intermediate values
7643 -- in expressions always are of the base type, not a subtype of it.
7646 Resolve (R, Standard_Natural);
7648 Check_Unset_Reference (L);
7649 Check_Unset_Reference (R);
7651 Set_Etype (N, B_Typ);
7652 Generate_Operator_Reference (N, B_Typ);
7656 ---------------------------
7657 -- Resolve_Short_Circuit --
7658 ---------------------------
7660 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7661 B_Typ : constant Entity_Id := Base_Type (Typ);
7662 L : constant Node_Id := Left_Opnd (N);
7663 R : constant Node_Id := Right_Opnd (N);
7669 -- Check for issuing warning for always False assert/check, this happens
7670 -- when assertions are turned off, in which case the pragma Assert/Check
7671 -- was transformed into:
7673 -- if False and then <condition> then ...
7675 -- and we detect this pattern
7677 if Warn_On_Assertion_Failure
7678 and then Is_Entity_Name (R)
7679 and then Entity (R) = Standard_False
7680 and then Nkind (Parent (N)) = N_If_Statement
7681 and then Nkind (N) = N_And_Then
7682 and then Is_Entity_Name (L)
7683 and then Entity (L) = Standard_False
7686 Orig : constant Node_Id := Original_Node (Parent (N));
7689 if Nkind (Orig) = N_Pragma
7690 and then Pragma_Name (Orig) = Name_Assert
7692 -- Don't want to warn if original condition is explicit False
7695 Expr : constant Node_Id :=
7698 (First (Pragma_Argument_Associations (Orig))));
7700 if Is_Entity_Name (Expr)
7701 and then Entity (Expr) = Standard_False
7705 -- Issue warning. Note that we don't want to make this
7706 -- an unconditional warning, because if the assert is
7707 -- within deleted code we do not want the warning. But
7708 -- we do not want the deletion of the IF/AND-THEN to
7709 -- take this message with it. We achieve this by making
7710 -- sure that the expanded code points to the Sloc of
7711 -- the expression, not the original pragma.
7713 Error_Msg_N ("?assertion would fail at run-time", Orig);
7717 -- Similar processing for Check pragma
7719 elsif Nkind (Orig) = N_Pragma
7720 and then Pragma_Name (Orig) = Name_Check
7722 -- Don't want to warn if original condition is explicit False
7725 Expr : constant Node_Id :=
7729 (Pragma_Argument_Associations (Orig)))));
7731 if Is_Entity_Name (Expr)
7732 and then Entity (Expr) = Standard_False
7736 Error_Msg_N ("?check would fail at run-time", Orig);
7743 -- Continue with processing of short circuit
7745 Check_Unset_Reference (L);
7746 Check_Unset_Reference (R);
7748 Set_Etype (N, B_Typ);
7749 Eval_Short_Circuit (N);
7750 end Resolve_Short_Circuit;
7756 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7757 Name : constant Node_Id := Prefix (N);
7758 Drange : constant Node_Id := Discrete_Range (N);
7759 Array_Type : Entity_Id := Empty;
7763 if Is_Overloaded (Name) then
7765 -- Use the context type to select the prefix that yields the correct
7770 I1 : Interp_Index := 0;
7772 P : constant Node_Id := Prefix (N);
7773 Found : Boolean := False;
7776 Get_First_Interp (P, I, It);
7777 while Present (It.Typ) loop
7778 if (Is_Array_Type (It.Typ)
7779 and then Covers (Typ, It.Typ))
7780 or else (Is_Access_Type (It.Typ)
7781 and then Is_Array_Type (Designated_Type (It.Typ))
7782 and then Covers (Typ, Designated_Type (It.Typ)))
7785 It := Disambiguate (P, I1, I, Any_Type);
7787 if It = No_Interp then
7788 Error_Msg_N ("ambiguous prefix for slicing", N);
7793 Array_Type := It.Typ;
7798 Array_Type := It.Typ;
7803 Get_Next_Interp (I, It);
7808 Array_Type := Etype (Name);
7811 Resolve (Name, Array_Type);
7813 if Is_Access_Type (Array_Type) then
7814 Apply_Access_Check (N);
7815 Array_Type := Designated_Type (Array_Type);
7817 -- If the prefix is an access to an unconstrained array, we must use
7818 -- the actual subtype of the object to perform the index checks. The
7819 -- object denoted by the prefix is implicit in the node, so we build
7820 -- an explicit representation for it in order to compute the actual
7823 if not Is_Constrained (Array_Type) then
7824 Remove_Side_Effects (Prefix (N));
7827 Obj : constant Node_Id :=
7828 Make_Explicit_Dereference (Sloc (N),
7829 Prefix => New_Copy_Tree (Prefix (N)));
7831 Set_Etype (Obj, Array_Type);
7832 Set_Parent (Obj, Parent (N));
7833 Array_Type := Get_Actual_Subtype (Obj);
7837 elsif Is_Entity_Name (Name)
7838 or else (Nkind (Name) = N_Function_Call
7839 and then not Is_Constrained (Etype (Name)))
7841 Array_Type := Get_Actual_Subtype (Name);
7843 -- If the name is a selected component that depends on discriminants,
7844 -- build an actual subtype for it. This can happen only when the name
7845 -- itself is overloaded; otherwise the actual subtype is created when
7846 -- the selected component is analyzed.
7848 elsif Nkind (Name) = N_Selected_Component
7849 and then Full_Analysis
7850 and then Depends_On_Discriminant (First_Index (Array_Type))
7853 Act_Decl : constant Node_Id :=
7854 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7856 Insert_Action (N, Act_Decl);
7857 Array_Type := Defining_Identifier (Act_Decl);
7861 -- If name was overloaded, set slice type correctly now
7863 Set_Etype (N, Array_Type);
7865 -- If the range is specified by a subtype mark, no resolution is
7866 -- necessary. Else resolve the bounds, and apply needed checks.
7868 if not Is_Entity_Name (Drange) then
7869 Index := First_Index (Array_Type);
7870 Resolve (Drange, Base_Type (Etype (Index)));
7872 if Nkind (Drange) = N_Range
7874 -- Do not apply the range check to nodes associated with the
7875 -- frontend expansion of the dispatch table. We first check
7876 -- if Ada.Tags is already loaded to void the addition of an
7877 -- undesired dependence on such run-time unit.
7880 (not Tagged_Type_Expansion
7882 (RTU_Loaded (Ada_Tags)
7883 and then Nkind (Prefix (N)) = N_Selected_Component
7884 and then Present (Entity (Selector_Name (Prefix (N))))
7885 and then Entity (Selector_Name (Prefix (N))) =
7886 RTE_Record_Component (RE_Prims_Ptr)))
7888 Apply_Range_Check (Drange, Etype (Index));
7892 Set_Slice_Subtype (N);
7894 if Nkind (Drange) = N_Range then
7895 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7896 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7902 ----------------------------
7903 -- Resolve_String_Literal --
7904 ----------------------------
7906 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7907 C_Typ : constant Entity_Id := Component_Type (Typ);
7908 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7909 Loc : constant Source_Ptr := Sloc (N);
7910 Str : constant String_Id := Strval (N);
7911 Strlen : constant Nat := String_Length (Str);
7912 Subtype_Id : Entity_Id;
7913 Need_Check : Boolean;
7916 -- For a string appearing in a concatenation, defer creation of the
7917 -- string_literal_subtype until the end of the resolution of the
7918 -- concatenation, because the literal may be constant-folded away. This
7919 -- is a useful optimization for long concatenation expressions.
7921 -- If the string is an aggregate built for a single character (which
7922 -- happens in a non-static context) or a is null string to which special
7923 -- checks may apply, we build the subtype. Wide strings must also get a
7924 -- string subtype if they come from a one character aggregate. Strings
7925 -- generated by attributes might be static, but it is often hard to
7926 -- determine whether the enclosing context is static, so we generate
7927 -- subtypes for them as well, thus losing some rarer optimizations ???
7928 -- Same for strings that come from a static conversion.
7931 (Strlen = 0 and then Typ /= Standard_String)
7932 or else Nkind (Parent (N)) /= N_Op_Concat
7933 or else (N /= Left_Opnd (Parent (N))
7934 and then N /= Right_Opnd (Parent (N)))
7935 or else ((Typ = Standard_Wide_String
7936 or else Typ = Standard_Wide_Wide_String)
7937 and then Nkind (Original_Node (N)) /= N_String_Literal);
7939 -- If the resolving type is itself a string literal subtype, we can just
7940 -- reuse it, since there is no point in creating another.
7942 if Ekind (Typ) = E_String_Literal_Subtype then
7945 elsif Nkind (Parent (N)) = N_Op_Concat
7946 and then not Need_Check
7947 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7948 N_Attribute_Reference,
7949 N_Qualified_Expression,
7954 -- Otherwise we must create a string literal subtype. Note that the
7955 -- whole idea of string literal subtypes is simply to avoid the need
7956 -- for building a full fledged array subtype for each literal.
7959 Set_String_Literal_Subtype (N, Typ);
7960 Subtype_Id := Etype (N);
7963 if Nkind (Parent (N)) /= N_Op_Concat
7966 Set_Etype (N, Subtype_Id);
7967 Eval_String_Literal (N);
7970 if Is_Limited_Composite (Typ)
7971 or else Is_Private_Composite (Typ)
7973 Error_Msg_N ("string literal not available for private array", N);
7974 Set_Etype (N, Any_Type);
7978 -- The validity of a null string has been checked in the call to
7979 -- Eval_String_Literal.
7984 -- Always accept string literal with component type Any_Character, which
7985 -- occurs in error situations and in comparisons of literals, both of
7986 -- which should accept all literals.
7988 elsif R_Typ = Any_Character then
7991 -- If the type is bit-packed, then we always transform the string
7992 -- literal into a full fledged aggregate.
7994 elsif Is_Bit_Packed_Array (Typ) then
7997 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8000 -- For Standard.Wide_Wide_String, or any other type whose component
8001 -- type is Standard.Wide_Wide_Character, we know that all the
8002 -- characters in the string must be acceptable, since the parser
8003 -- accepted the characters as valid character literals.
8005 if R_Typ = Standard_Wide_Wide_Character then
8008 -- For the case of Standard.String, or any other type whose component
8009 -- type is Standard.Character, we must make sure that there are no
8010 -- wide characters in the string, i.e. that it is entirely composed
8011 -- of characters in range of type Character.
8013 -- If the string literal is the result of a static concatenation, the
8014 -- test has already been performed on the components, and need not be
8017 elsif R_Typ = Standard_Character
8018 and then Nkind (Original_Node (N)) /= N_Op_Concat
8020 for J in 1 .. Strlen loop
8021 if not In_Character_Range (Get_String_Char (Str, J)) then
8023 -- If we are out of range, post error. This is one of the
8024 -- very few places that we place the flag in the middle of
8025 -- a token, right under the offending wide character. Not
8026 -- quite clear if this is right wrt wide character encoding
8027 -- sequences, but it's only an error message!
8030 ("literal out of range of type Standard.Character",
8031 Source_Ptr (Int (Loc) + J));
8036 -- For the case of Standard.Wide_String, or any other type whose
8037 -- component type is Standard.Wide_Character, we must make sure that
8038 -- there are no wide characters in the string, i.e. that it is
8039 -- entirely composed of characters in range of type Wide_Character.
8041 -- If the string literal is the result of a static concatenation,
8042 -- the test has already been performed on the components, and need
8045 elsif R_Typ = Standard_Wide_Character
8046 and then Nkind (Original_Node (N)) /= N_Op_Concat
8048 for J in 1 .. Strlen loop
8049 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8051 -- If we are out of range, post error. This is one of the
8052 -- very few places that we place the flag in the middle of
8053 -- a token, right under the offending wide character.
8055 -- This is not quite right, because characters in general
8056 -- will take more than one character position ???
8059 ("literal out of range of type Standard.Wide_Character",
8060 Source_Ptr (Int (Loc) + J));
8065 -- If the root type is not a standard character, then we will convert
8066 -- the string into an aggregate and will let the aggregate code do
8067 -- the checking. Standard Wide_Wide_Character is also OK here.
8073 -- See if the component type of the array corresponding to the string
8074 -- has compile time known bounds. If yes we can directly check
8075 -- whether the evaluation of the string will raise constraint error.
8076 -- Otherwise we need to transform the string literal into the
8077 -- corresponding character aggregate and let the aggregate
8078 -- code do the checking.
8080 if Is_Standard_Character_Type (R_Typ) then
8082 -- Check for the case of full range, where we are definitely OK
8084 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8088 -- Here the range is not the complete base type range, so check
8091 Comp_Typ_Lo : constant Node_Id :=
8092 Type_Low_Bound (Component_Type (Typ));
8093 Comp_Typ_Hi : constant Node_Id :=
8094 Type_High_Bound (Component_Type (Typ));
8099 if Compile_Time_Known_Value (Comp_Typ_Lo)
8100 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8102 for J in 1 .. Strlen loop
8103 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8105 if Char_Val < Expr_Value (Comp_Typ_Lo)
8106 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8108 Apply_Compile_Time_Constraint_Error
8109 (N, "character out of range?", CE_Range_Check_Failed,
8110 Loc => Source_Ptr (Int (Loc) + J));
8120 -- If we got here we meed to transform the string literal into the
8121 -- equivalent qualified positional array aggregate. This is rather
8122 -- heavy artillery for this situation, but it is hard work to avoid.
8125 Lits : constant List_Id := New_List;
8126 P : Source_Ptr := Loc + 1;
8130 -- Build the character literals, we give them source locations that
8131 -- correspond to the string positions, which is a bit tricky given
8132 -- the possible presence of wide character escape sequences.
8134 for J in 1 .. Strlen loop
8135 C := Get_String_Char (Str, J);
8136 Set_Character_Literal_Name (C);
8139 Make_Character_Literal (P,
8141 Char_Literal_Value => UI_From_CC (C)));
8143 if In_Character_Range (C) then
8146 -- Should we have a call to Skip_Wide here ???
8154 Make_Qualified_Expression (Loc,
8155 Subtype_Mark => New_Reference_To (Typ, Loc),
8157 Make_Aggregate (Loc, Expressions => Lits)));
8159 Analyze_And_Resolve (N, Typ);
8161 end Resolve_String_Literal;
8163 -----------------------------
8164 -- Resolve_Subprogram_Info --
8165 -----------------------------
8167 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8170 end Resolve_Subprogram_Info;
8172 -----------------------------
8173 -- Resolve_Type_Conversion --
8174 -----------------------------
8176 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8177 Conv_OK : constant Boolean := Conversion_OK (N);
8178 Operand : constant Node_Id := Expression (N);
8179 Operand_Typ : constant Entity_Id := Etype (Operand);
8180 Target_Typ : constant Entity_Id := Etype (N);
8187 and then not Valid_Conversion (N, Target_Typ, Operand)
8192 if Etype (Operand) = Any_Fixed then
8194 -- Mixed-mode operation involving a literal. Context must be a fixed
8195 -- type which is applied to the literal subsequently.
8197 if Is_Fixed_Point_Type (Typ) then
8198 Set_Etype (Operand, Universal_Real);
8200 elsif Is_Numeric_Type (Typ)
8201 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8202 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8204 Etype (Left_Opnd (Operand)) = Universal_Real)
8206 -- Return if expression is ambiguous
8208 if Unique_Fixed_Point_Type (N) = Any_Type then
8211 -- If nothing else, the available fixed type is Duration
8214 Set_Etype (Operand, Standard_Duration);
8217 -- Resolve the real operand with largest available precision
8219 if Etype (Right_Opnd (Operand)) = Universal_Real then
8220 Rop := New_Copy_Tree (Right_Opnd (Operand));
8222 Rop := New_Copy_Tree (Left_Opnd (Operand));
8225 Resolve (Rop, Universal_Real);
8227 -- If the operand is a literal (it could be a non-static and
8228 -- illegal exponentiation) check whether the use of Duration
8229 -- is potentially inaccurate.
8231 if Nkind (Rop) = N_Real_Literal
8232 and then Realval (Rop) /= Ureal_0
8233 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8236 ("?universal real operand can only " &
8237 "be interpreted as Duration!",
8240 ("\?precision will be lost in the conversion!", Rop);
8243 elsif Is_Numeric_Type (Typ)
8244 and then Nkind (Operand) in N_Op
8245 and then Unique_Fixed_Point_Type (N) /= Any_Type
8247 Set_Etype (Operand, Standard_Duration);
8250 Error_Msg_N ("invalid context for mixed mode operation", N);
8251 Set_Etype (Operand, Any_Type);
8258 -- Note: we do the Eval_Type_Conversion call before applying the
8259 -- required checks for a subtype conversion. This is important, since
8260 -- both are prepared under certain circumstances to change the type
8261 -- conversion to a constraint error node, but in the case of
8262 -- Eval_Type_Conversion this may reflect an illegality in the static
8263 -- case, and we would miss the illegality (getting only a warning
8264 -- message), if we applied the type conversion checks first.
8266 Eval_Type_Conversion (N);
8268 -- Even when evaluation is not possible, we may be able to simplify the
8269 -- conversion or its expression. This needs to be done before applying
8270 -- checks, since otherwise the checks may use the original expression
8271 -- and defeat the simplifications. This is specifically the case for
8272 -- elimination of the floating-point Truncation attribute in
8273 -- float-to-int conversions.
8275 Simplify_Type_Conversion (N);
8277 -- If after evaluation we still have a type conversion, then we may need
8278 -- to apply checks required for a subtype conversion.
8280 -- Skip these type conversion checks if universal fixed operands
8281 -- operands involved, since range checks are handled separately for
8282 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8284 if Nkind (N) = N_Type_Conversion
8285 and then not Is_Generic_Type (Root_Type (Target_Typ))
8286 and then Target_Typ /= Universal_Fixed
8287 and then Operand_Typ /= Universal_Fixed
8289 Apply_Type_Conversion_Checks (N);
8292 -- Issue warning for conversion of simple object to its own type. We
8293 -- have to test the original nodes, since they may have been rewritten
8294 -- by various optimizations.
8296 Orig_N := Original_Node (N);
8298 if Warn_On_Redundant_Constructs
8299 and then Comes_From_Source (Orig_N)
8300 and then Nkind (Orig_N) = N_Type_Conversion
8301 and then not In_Instance
8303 Orig_N := Original_Node (Expression (Orig_N));
8304 Orig_T := Target_Typ;
8306 -- If the node is part of a larger expression, the Target_Type
8307 -- may not be the original type of the node if the context is a
8308 -- condition. Recover original type to see if conversion is needed.
8310 if Is_Boolean_Type (Orig_T)
8311 and then Nkind (Parent (N)) in N_Op
8313 Orig_T := Etype (Parent (N));
8316 if Is_Entity_Name (Orig_N)
8318 (Etype (Entity (Orig_N)) = Orig_T
8320 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8321 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8323 Error_Msg_Node_2 := Orig_T;
8324 Error_Msg_NE -- CODEFIX
8325 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8329 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8330 -- No need to perform any interface conversion if the type of the
8331 -- expression coincides with the target type.
8333 if Ada_Version >= Ada_05
8334 and then Expander_Active
8335 and then Operand_Typ /= Target_Typ
8338 Opnd : Entity_Id := Operand_Typ;
8339 Target : Entity_Id := Target_Typ;
8342 if Is_Access_Type (Opnd) then
8343 Opnd := Directly_Designated_Type (Opnd);
8346 if Is_Access_Type (Target_Typ) then
8347 Target := Directly_Designated_Type (Target);
8350 if Opnd = Target then
8353 -- Conversion from interface type
8355 elsif Is_Interface (Opnd) then
8357 -- Ada 2005 (AI-217): Handle entities from limited views
8359 if From_With_Type (Opnd) then
8360 Error_Msg_Qual_Level := 99;
8361 Error_Msg_NE ("missing WITH clause on package &", N,
8362 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8364 ("type conversions require visibility of the full view",
8367 elsif From_With_Type (Target)
8369 (Is_Access_Type (Target_Typ)
8370 and then Present (Non_Limited_View (Etype (Target))))
8372 Error_Msg_Qual_Level := 99;
8373 Error_Msg_NE ("missing WITH clause on package &", N,
8374 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8376 ("type conversions require visibility of the full view",
8380 Expand_Interface_Conversion (N, Is_Static => False);
8383 -- Conversion to interface type
8385 elsif Is_Interface (Target) then
8389 if Ekind (Opnd) = E_Protected_Subtype
8390 or else Ekind (Opnd) = E_Task_Subtype
8392 Opnd := Etype (Opnd);
8395 if not Interface_Present_In_Ancestor
8399 if Is_Class_Wide_Type (Opnd) then
8401 -- The static analysis is not enough to know if the
8402 -- interface is implemented or not. Hence we must pass
8403 -- the work to the expander to generate code to evaluate
8404 -- the conversion at run-time.
8406 Expand_Interface_Conversion (N, Is_Static => False);
8409 Error_Msg_Name_1 := Chars (Etype (Target));
8410 Error_Msg_Name_2 := Chars (Opnd);
8412 ("wrong interface conversion (% is not a progenitor " &
8417 Expand_Interface_Conversion (N);
8422 end Resolve_Type_Conversion;
8424 ----------------------
8425 -- Resolve_Unary_Op --
8426 ----------------------
8428 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8429 B_Typ : constant Entity_Id := Base_Type (Typ);
8430 R : constant Node_Id := Right_Opnd (N);
8436 -- Deal with intrinsic unary operators
8438 if Comes_From_Source (N)
8439 and then Ekind (Entity (N)) = E_Function
8440 and then Is_Imported (Entity (N))
8441 and then Is_Intrinsic_Subprogram (Entity (N))
8443 Resolve_Intrinsic_Unary_Operator (N, Typ);
8447 -- Deal with universal cases
8449 if Etype (R) = Universal_Integer
8451 Etype (R) = Universal_Real
8453 Check_For_Visible_Operator (N, B_Typ);
8456 Set_Etype (N, B_Typ);
8459 -- Generate warning for expressions like abs (x mod 2)
8461 if Warn_On_Redundant_Constructs
8462 and then Nkind (N) = N_Op_Abs
8464 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8466 if OK and then Hi >= Lo and then Lo >= 0 then
8468 ("?abs applied to known non-negative value has no effect", N);
8472 -- Deal with reference generation
8474 Check_Unset_Reference (R);
8475 Generate_Operator_Reference (N, B_Typ);
8478 -- Set overflow checking bit. Much cleverer code needed here eventually
8479 -- and perhaps the Resolve routines should be separated for the various
8480 -- arithmetic operations, since they will need different processing ???
8482 if Nkind (N) in N_Op then
8483 if not Overflow_Checks_Suppressed (Etype (N)) then
8484 Enable_Overflow_Check (N);
8488 -- Generate warning for expressions like -5 mod 3 for integers. No need
8489 -- to worry in the floating-point case, since parens do not affect the
8490 -- result so there is no point in giving in a warning.
8493 Norig : constant Node_Id := Original_Node (N);
8502 if Warn_On_Questionable_Missing_Parens
8503 and then Comes_From_Source (Norig)
8504 and then Is_Integer_Type (Typ)
8505 and then Nkind (Norig) = N_Op_Minus
8507 Rorig := Original_Node (Right_Opnd (Norig));
8509 -- We are looking for cases where the right operand is not
8510 -- parenthesized, and is a binary operator, multiply, divide, or
8511 -- mod. These are the cases where the grouping can affect results.
8513 if Paren_Count (Rorig) = 0
8514 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8516 -- For mod, we always give the warning, since the value is
8517 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8518 -- -(5 mod 315)). But for the other cases, the only concern is
8519 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8520 -- overflows, but (-2) * 64 does not). So we try to give the
8521 -- message only when overflow is possible.
8523 if Nkind (Rorig) /= N_Op_Mod
8524 and then Compile_Time_Known_Value (R)
8526 Val := Expr_Value (R);
8528 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8529 HB := Expr_Value (Type_High_Bound (Typ));
8531 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8534 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8535 LB := Expr_Value (Type_Low_Bound (Typ));
8537 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8540 -- Note that the test below is deliberately excluding the
8541 -- largest negative number, since that is a potentially
8542 -- troublesome case (e.g. -2 * x, where the result is the
8543 -- largest negative integer has an overflow with 2 * x).
8545 if Val > LB and then Val <= HB then
8550 -- For the multiplication case, the only case we have to worry
8551 -- about is when (-a)*b is exactly the largest negative number
8552 -- so that -(a*b) can cause overflow. This can only happen if
8553 -- a is a power of 2, and more generally if any operand is a
8554 -- constant that is not a power of 2, then the parentheses
8555 -- cannot affect whether overflow occurs. We only bother to
8556 -- test the left most operand
8558 -- Loop looking at left operands for one that has known value
8561 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8562 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8563 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8565 -- Operand value of 0 or 1 skips warning
8570 -- Otherwise check power of 2, if power of 2, warn, if
8571 -- anything else, skip warning.
8574 while Lval /= 2 loop
8575 if Lval mod 2 = 1 then
8586 -- Keep looking at left operands
8588 Opnd := Left_Opnd (Opnd);
8591 -- For rem or "/" we can only have a problematic situation
8592 -- if the divisor has a value of minus one or one. Otherwise
8593 -- overflow is impossible (divisor > 1) or we have a case of
8594 -- division by zero in any case.
8596 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8597 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8598 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8603 -- If we fall through warning should be issued
8606 ("?unary minus expression should be parenthesized here!", N);
8610 end Resolve_Unary_Op;
8612 ----------------------------------
8613 -- Resolve_Unchecked_Expression --
8614 ----------------------------------
8616 procedure Resolve_Unchecked_Expression
8621 Resolve (Expression (N), Typ, Suppress => All_Checks);
8623 end Resolve_Unchecked_Expression;
8625 ---------------------------------------
8626 -- Resolve_Unchecked_Type_Conversion --
8627 ---------------------------------------
8629 procedure Resolve_Unchecked_Type_Conversion
8633 pragma Warnings (Off, Typ);
8635 Operand : constant Node_Id := Expression (N);
8636 Opnd_Type : constant Entity_Id := Etype (Operand);
8639 -- Resolve operand using its own type
8641 Resolve (Operand, Opnd_Type);
8642 Eval_Unchecked_Conversion (N);
8644 end Resolve_Unchecked_Type_Conversion;
8646 ------------------------------
8647 -- Rewrite_Operator_As_Call --
8648 ------------------------------
8650 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8651 Loc : constant Source_Ptr := Sloc (N);
8652 Actuals : constant List_Id := New_List;
8656 if Nkind (N) in N_Binary_Op then
8657 Append (Left_Opnd (N), Actuals);
8660 Append (Right_Opnd (N), Actuals);
8663 Make_Function_Call (Sloc => Loc,
8664 Name => New_Occurrence_Of (Nam, Loc),
8665 Parameter_Associations => Actuals);
8667 Preserve_Comes_From_Source (New_N, N);
8668 Preserve_Comes_From_Source (Name (New_N), N);
8670 Set_Etype (N, Etype (Nam));
8671 end Rewrite_Operator_As_Call;
8673 ------------------------------
8674 -- Rewrite_Renamed_Operator --
8675 ------------------------------
8677 procedure Rewrite_Renamed_Operator
8682 Nam : constant Name_Id := Chars (Op);
8683 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8687 -- Rewrite the operator node using the real operator, not its renaming.
8688 -- Exclude user-defined intrinsic operations of the same name, which are
8689 -- treated separately and rewritten as calls.
8691 if Ekind (Op) /= E_Function
8692 or else Chars (N) /= Nam
8694 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8695 Set_Chars (Op_Node, Nam);
8696 Set_Etype (Op_Node, Etype (N));
8697 Set_Entity (Op_Node, Op);
8698 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8700 -- Indicate that both the original entity and its renaming are
8701 -- referenced at this point.
8703 Generate_Reference (Entity (N), N);
8704 Generate_Reference (Op, N);
8707 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8710 Rewrite (N, Op_Node);
8712 -- If the context type is private, add the appropriate conversions
8713 -- so that the operator is applied to the full view. This is done
8714 -- in the routines that resolve intrinsic operators,
8716 if Is_Intrinsic_Subprogram (Op)
8717 and then Is_Private_Type (Typ)
8720 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8721 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8722 Resolve_Intrinsic_Operator (N, Typ);
8724 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8725 Resolve_Intrinsic_Unary_Operator (N, Typ);
8732 elsif Ekind (Op) = E_Function
8733 and then Is_Intrinsic_Subprogram (Op)
8735 -- Operator renames a user-defined operator of the same name. Use
8736 -- the original operator in the node, which is the one that Gigi
8740 Set_Is_Overloaded (N, False);
8742 end Rewrite_Renamed_Operator;
8744 -----------------------
8745 -- Set_Slice_Subtype --
8746 -----------------------
8748 -- Build an implicit subtype declaration to represent the type delivered
8749 -- by the slice. This is an abbreviated version of an array subtype. We
8750 -- define an index subtype for the slice, using either the subtype name
8751 -- or the discrete range of the slice. To be consistent with index usage
8752 -- elsewhere, we create a list header to hold the single index. This list
8753 -- is not otherwise attached to the syntax tree.
8755 procedure Set_Slice_Subtype (N : Node_Id) is
8756 Loc : constant Source_Ptr := Sloc (N);
8757 Index_List : constant List_Id := New_List;
8759 Index_Subtype : Entity_Id;
8760 Index_Type : Entity_Id;
8761 Slice_Subtype : Entity_Id;
8762 Drange : constant Node_Id := Discrete_Range (N);
8765 if Is_Entity_Name (Drange) then
8766 Index_Subtype := Entity (Drange);
8769 -- We force the evaluation of a range. This is definitely needed in
8770 -- the renamed case, and seems safer to do unconditionally. Note in
8771 -- any case that since we will create and insert an Itype referring
8772 -- to this range, we must make sure any side effect removal actions
8773 -- are inserted before the Itype definition.
8775 if Nkind (Drange) = N_Range then
8776 Force_Evaluation (Low_Bound (Drange));
8777 Force_Evaluation (High_Bound (Drange));
8780 Index_Type := Base_Type (Etype (Drange));
8782 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8784 Set_Scalar_Range (Index_Subtype, Drange);
8785 Set_Etype (Index_Subtype, Index_Type);
8786 Set_Size_Info (Index_Subtype, Index_Type);
8787 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8790 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8792 Index := New_Occurrence_Of (Index_Subtype, Loc);
8793 Set_Etype (Index, Index_Subtype);
8794 Append (Index, Index_List);
8796 Set_First_Index (Slice_Subtype, Index);
8797 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8798 Set_Is_Constrained (Slice_Subtype, True);
8800 Check_Compile_Time_Size (Slice_Subtype);
8802 -- The Etype of the existing Slice node is reset to this slice subtype.
8803 -- Its bounds are obtained from its first index.
8805 Set_Etype (N, Slice_Subtype);
8807 -- In the packed case, this must be immediately frozen
8809 -- Couldn't we always freeze here??? and if we did, then the above
8810 -- call to Check_Compile_Time_Size could be eliminated, which would
8811 -- be nice, because then that routine could be made private to Freeze.
8813 -- Why the test for In_Spec_Expression here ???
8815 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8816 Freeze_Itype (Slice_Subtype, N);
8819 end Set_Slice_Subtype;
8821 --------------------------------
8822 -- Set_String_Literal_Subtype --
8823 --------------------------------
8825 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8826 Loc : constant Source_Ptr := Sloc (N);
8827 Low_Bound : constant Node_Id :=
8828 Type_Low_Bound (Etype (First_Index (Typ)));
8829 Subtype_Id : Entity_Id;
8832 if Nkind (N) /= N_String_Literal then
8836 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8837 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8838 (String_Length (Strval (N))));
8839 Set_Etype (Subtype_Id, Base_Type (Typ));
8840 Set_Is_Constrained (Subtype_Id);
8841 Set_Etype (N, Subtype_Id);
8843 if Is_OK_Static_Expression (Low_Bound) then
8845 -- The low bound is set from the low bound of the corresponding
8846 -- index type. Note that we do not store the high bound in the
8847 -- string literal subtype, but it can be deduced if necessary
8848 -- from the length and the low bound.
8850 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8853 Set_String_Literal_Low_Bound
8854 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8855 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8857 -- Build bona fide subtype for the string, and wrap it in an
8858 -- unchecked conversion, because the backend expects the
8859 -- String_Literal_Subtype to have a static lower bound.
8862 Index_List : constant List_Id := New_List;
8863 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8864 High_Bound : constant Node_Id :=
8866 Left_Opnd => New_Copy_Tree (Low_Bound),
8868 Make_Integer_Literal (Loc,
8869 String_Length (Strval (N)) - 1));
8870 Array_Subtype : Entity_Id;
8871 Index_Subtype : Entity_Id;
8877 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8878 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8879 Set_Scalar_Range (Index_Subtype, Drange);
8880 Set_Parent (Drange, N);
8881 Analyze_And_Resolve (Drange, Index_Type);
8883 -- In the context, the Index_Type may already have a constraint,
8884 -- so use common base type on string subtype. The base type may
8885 -- be used when generating attributes of the string, for example
8886 -- in the context of a slice assignment.
8888 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8889 Set_Size_Info (Index_Subtype, Index_Type);
8890 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8892 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8894 Index := New_Occurrence_Of (Index_Subtype, Loc);
8895 Set_Etype (Index, Index_Subtype);
8896 Append (Index, Index_List);
8898 Set_First_Index (Array_Subtype, Index);
8899 Set_Etype (Array_Subtype, Base_Type (Typ));
8900 Set_Is_Constrained (Array_Subtype, True);
8903 Make_Unchecked_Type_Conversion (Loc,
8904 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8905 Expression => Relocate_Node (N)));
8906 Set_Etype (N, Array_Subtype);
8909 end Set_String_Literal_Subtype;
8911 ------------------------------
8912 -- Simplify_Type_Conversion --
8913 ------------------------------
8915 procedure Simplify_Type_Conversion (N : Node_Id) is
8917 if Nkind (N) = N_Type_Conversion then
8919 Operand : constant Node_Id := Expression (N);
8920 Target_Typ : constant Entity_Id := Etype (N);
8921 Opnd_Typ : constant Entity_Id := Etype (Operand);
8924 if Is_Floating_Point_Type (Opnd_Typ)
8926 (Is_Integer_Type (Target_Typ)
8927 or else (Is_Fixed_Point_Type (Target_Typ)
8928 and then Conversion_OK (N)))
8929 and then Nkind (Operand) = N_Attribute_Reference
8930 and then Attribute_Name (Operand) = Name_Truncation
8932 -- Special processing required if the conversion is the expression
8933 -- of a Truncation attribute reference. In this case we replace:
8935 -- ityp (ftyp'Truncation (x))
8941 -- with the Float_Truncate flag set, which is more efficient
8945 Relocate_Node (First (Expressions (Operand))));
8946 Set_Float_Truncate (N, True);
8950 end Simplify_Type_Conversion;
8952 -----------------------------
8953 -- Unique_Fixed_Point_Type --
8954 -----------------------------
8956 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8957 T1 : Entity_Id := Empty;
8962 procedure Fixed_Point_Error;
8963 -- Give error messages for true ambiguity. Messages are posted on node
8964 -- N, and entities T1, T2 are the possible interpretations.
8966 -----------------------
8967 -- Fixed_Point_Error --
8968 -----------------------
8970 procedure Fixed_Point_Error is
8972 Error_Msg_N ("ambiguous universal_fixed_expression", N);
8973 Error_Msg_NE ("\\possible interpretation as}", N, T1);
8974 Error_Msg_NE ("\\possible interpretation as}", N, T2);
8975 end Fixed_Point_Error;
8977 -- Start of processing for Unique_Fixed_Point_Type
8980 -- The operations on Duration are visible, so Duration is always a
8981 -- possible interpretation.
8983 T1 := Standard_Duration;
8985 -- Look for fixed-point types in enclosing scopes
8987 Scop := Current_Scope;
8988 while Scop /= Standard_Standard loop
8989 T2 := First_Entity (Scop);
8990 while Present (T2) loop
8991 if Is_Fixed_Point_Type (T2)
8992 and then Current_Entity (T2) = T2
8993 and then Scope (Base_Type (T2)) = Scop
8995 if Present (T1) then
9006 Scop := Scope (Scop);
9009 -- Look for visible fixed type declarations in the context
9011 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
9012 while Present (Item) loop
9013 if Nkind (Item) = N_With_Clause then
9014 Scop := Entity (Name (Item));
9015 T2 := First_Entity (Scop);
9016 while Present (T2) loop
9017 if Is_Fixed_Point_Type (T2)
9018 and then Scope (Base_Type (T2)) = Scop
9019 and then (Is_Potentially_Use_Visible (T2)
9020 or else In_Use (T2))
9022 if Present (T1) then
9037 if Nkind (N) = N_Real_Literal then
9038 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9040 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9044 end Unique_Fixed_Point_Type;
9046 ----------------------
9047 -- Valid_Conversion --
9048 ----------------------
9050 function Valid_Conversion
9053 Operand : Node_Id) return Boolean
9055 Target_Type : constant Entity_Id := Base_Type (Target);
9056 Opnd_Type : Entity_Id := Etype (Operand);
9058 function Conversion_Check
9060 Msg : String) return Boolean;
9061 -- Little routine to post Msg if Valid is False, returns Valid value
9063 function Valid_Tagged_Conversion
9064 (Target_Type : Entity_Id;
9065 Opnd_Type : Entity_Id) return Boolean;
9066 -- Specifically test for validity of tagged conversions
9068 function Valid_Array_Conversion return Boolean;
9069 -- Check index and component conformance, and accessibility levels
9070 -- if the component types are anonymous access types (Ada 2005)
9072 ----------------------
9073 -- Conversion_Check --
9074 ----------------------
9076 function Conversion_Check
9078 Msg : String) return Boolean
9082 Error_Msg_N (Msg, Operand);
9086 end Conversion_Check;
9088 ----------------------------
9089 -- Valid_Array_Conversion --
9090 ----------------------------
9092 function Valid_Array_Conversion return Boolean
9094 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9095 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9097 Opnd_Index : Node_Id;
9098 Opnd_Index_Type : Entity_Id;
9100 Target_Comp_Type : constant Entity_Id :=
9101 Component_Type (Target_Type);
9102 Target_Comp_Base : constant Entity_Id :=
9103 Base_Type (Target_Comp_Type);
9105 Target_Index : Node_Id;
9106 Target_Index_Type : Entity_Id;
9109 -- Error if wrong number of dimensions
9112 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9115 ("incompatible number of dimensions for conversion", Operand);
9118 -- Number of dimensions matches
9121 -- Loop through indexes of the two arrays
9123 Target_Index := First_Index (Target_Type);
9124 Opnd_Index := First_Index (Opnd_Type);
9125 while Present (Target_Index) and then Present (Opnd_Index) loop
9126 Target_Index_Type := Etype (Target_Index);
9127 Opnd_Index_Type := Etype (Opnd_Index);
9129 -- Error if index types are incompatible
9131 if not (Is_Integer_Type (Target_Index_Type)
9132 and then Is_Integer_Type (Opnd_Index_Type))
9133 and then (Root_Type (Target_Index_Type)
9134 /= Root_Type (Opnd_Index_Type))
9137 ("incompatible index types for array conversion",
9142 Next_Index (Target_Index);
9143 Next_Index (Opnd_Index);
9146 -- If component types have same base type, all set
9148 if Target_Comp_Base = Opnd_Comp_Base then
9151 -- Here if base types of components are not the same. The only
9152 -- time this is allowed is if we have anonymous access types.
9154 -- The conversion of arrays of anonymous access types can lead
9155 -- to dangling pointers. AI-392 formalizes the accessibility
9156 -- checks that must be applied to such conversions to prevent
9157 -- out-of-scope references.
9160 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9162 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9163 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9165 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9167 if Type_Access_Level (Target_Type) <
9168 Type_Access_Level (Opnd_Type)
9170 if In_Instance_Body then
9171 Error_Msg_N ("?source array type " &
9172 "has deeper accessibility level than target", Operand);
9173 Error_Msg_N ("\?Program_Error will be raised at run time",
9176 Make_Raise_Program_Error (Sloc (N),
9177 Reason => PE_Accessibility_Check_Failed));
9178 Set_Etype (N, Target_Type);
9181 -- Conversion not allowed because of accessibility levels
9184 Error_Msg_N ("source array type " &
9185 "has deeper accessibility level than target", Operand);
9192 -- All other cases where component base types do not match
9196 ("incompatible component types for array conversion",
9201 -- Check that component subtypes statically match. For numeric
9202 -- types this means that both must be either constrained or
9203 -- unconstrained. For enumeration types the bounds must match.
9204 -- All of this is checked in Subtypes_Statically_Match.
9206 if not Subtypes_Statically_Match
9207 (Target_Comp_Type, Opnd_Comp_Type)
9210 ("component subtypes must statically match", Operand);
9216 end Valid_Array_Conversion;
9218 -----------------------------
9219 -- Valid_Tagged_Conversion --
9220 -----------------------------
9222 function Valid_Tagged_Conversion
9223 (Target_Type : Entity_Id;
9224 Opnd_Type : Entity_Id) return Boolean
9227 -- Upward conversions are allowed (RM 4.6(22))
9229 if Covers (Target_Type, Opnd_Type)
9230 or else Is_Ancestor (Target_Type, Opnd_Type)
9234 -- Downward conversion are allowed if the operand is class-wide
9237 elsif Is_Class_Wide_Type (Opnd_Type)
9238 and then Covers (Opnd_Type, Target_Type)
9242 elsif Covers (Opnd_Type, Target_Type)
9243 or else Is_Ancestor (Opnd_Type, Target_Type)
9246 Conversion_Check (False,
9247 "downward conversion of tagged objects not allowed");
9249 -- Ada 2005 (AI-251): The conversion to/from interface types is
9252 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9255 -- If the operand is a class-wide type obtained through a limited_
9256 -- with clause, and the context includes the non-limited view, use
9257 -- it to determine whether the conversion is legal.
9259 elsif Is_Class_Wide_Type (Opnd_Type)
9260 and then From_With_Type (Opnd_Type)
9261 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9262 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9266 elsif Is_Access_Type (Opnd_Type)
9267 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9273 ("invalid tagged conversion, not compatible with}",
9274 N, First_Subtype (Opnd_Type));
9277 end Valid_Tagged_Conversion;
9279 -- Start of processing for Valid_Conversion
9282 Check_Parameterless_Call (Operand);
9284 if Is_Overloaded (Operand) then
9293 -- Remove procedure calls, which syntactically cannot appear in
9294 -- this context, but which cannot be removed by type checking,
9295 -- because the context does not impose a type.
9297 -- When compiling for VMS, spurious ambiguities can be produced
9298 -- when arithmetic operations have a literal operand and return
9299 -- System.Address or a descendant of it. These ambiguities are
9300 -- otherwise resolved by the context, but for conversions there
9301 -- is no context type and the removal of the spurious operations
9302 -- must be done explicitly here.
9304 -- The node may be labelled overloaded, but still contain only
9305 -- one interpretation because others were discarded in previous
9306 -- filters. If this is the case, retain the single interpretation
9309 Get_First_Interp (Operand, I, It);
9310 Opnd_Type := It.Typ;
9311 Get_Next_Interp (I, It);
9314 and then Opnd_Type /= Standard_Void_Type
9316 -- More than one candidate interpretation is available
9318 Get_First_Interp (Operand, I, It);
9319 while Present (It.Typ) loop
9320 if It.Typ = Standard_Void_Type then
9324 if Present (System_Aux_Id)
9325 and then Is_Descendent_Of_Address (It.Typ)
9330 Get_Next_Interp (I, It);
9334 Get_First_Interp (Operand, I, It);
9339 Error_Msg_N ("illegal operand in conversion", Operand);
9343 Get_Next_Interp (I, It);
9345 if Present (It.Typ) then
9347 It1 := Disambiguate (Operand, I1, I, Any_Type);
9349 if It1 = No_Interp then
9350 Error_Msg_N ("ambiguous operand in conversion", Operand);
9352 Error_Msg_Sloc := Sloc (It.Nam);
9353 Error_Msg_N -- CODEFIX
9354 ("\\possible interpretation#!", Operand);
9356 Error_Msg_Sloc := Sloc (N1);
9357 Error_Msg_N -- CODEFIX
9358 ("\\possible interpretation#!", Operand);
9364 Set_Etype (Operand, It1.Typ);
9365 Opnd_Type := It1.Typ;
9371 if Is_Numeric_Type (Target_Type) then
9373 -- A universal fixed expression can be converted to any numeric type
9375 if Opnd_Type = Universal_Fixed then
9378 -- Also no need to check when in an instance or inlined body, because
9379 -- the legality has been established when the template was analyzed.
9380 -- Furthermore, numeric conversions may occur where only a private
9381 -- view of the operand type is visible at the instantiation point.
9382 -- This results in a spurious error if we check that the operand type
9383 -- is a numeric type.
9385 -- Note: in a previous version of this unit, the following tests were
9386 -- applied only for generated code (Comes_From_Source set to False),
9387 -- but in fact the test is required for source code as well, since
9388 -- this situation can arise in source code.
9390 elsif In_Instance or else In_Inlined_Body then
9393 -- Otherwise we need the conversion check
9396 return Conversion_Check
9397 (Is_Numeric_Type (Opnd_Type),
9398 "illegal operand for numeric conversion");
9403 elsif Is_Array_Type (Target_Type) then
9404 if not Is_Array_Type (Opnd_Type)
9405 or else Opnd_Type = Any_Composite
9406 or else Opnd_Type = Any_String
9409 ("illegal operand for array conversion", Operand);
9412 return Valid_Array_Conversion;
9415 -- Ada 2005 (AI-251): Anonymous access types where target references an
9418 elsif (Ekind (Target_Type) = E_General_Access_Type
9420 Ekind (Target_Type) = E_Anonymous_Access_Type)
9421 and then Is_Interface (Directly_Designated_Type (Target_Type))
9423 -- Check the static accessibility rule of 4.6(17). Note that the
9424 -- check is not enforced when within an instance body, since the
9425 -- RM requires such cases to be caught at run time.
9427 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9428 if Type_Access_Level (Opnd_Type) >
9429 Type_Access_Level (Target_Type)
9431 -- In an instance, this is a run-time check, but one we know
9432 -- will fail, so generate an appropriate warning. The raise
9433 -- will be generated by Expand_N_Type_Conversion.
9435 if In_Instance_Body then
9437 ("?cannot convert local pointer to non-local access type",
9440 ("\?Program_Error will be raised at run time", Operand);
9443 ("cannot convert local pointer to non-local access type",
9448 -- Special accessibility checks are needed in the case of access
9449 -- discriminants declared for a limited type.
9451 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9452 and then not Is_Local_Anonymous_Access (Opnd_Type)
9454 -- When the operand is a selected access discriminant the check
9455 -- needs to be made against the level of the object denoted by
9456 -- the prefix of the selected name (Object_Access_Level handles
9457 -- checking the prefix of the operand for this case).
9459 if Nkind (Operand) = N_Selected_Component
9460 and then Object_Access_Level (Operand) >
9461 Type_Access_Level (Target_Type)
9463 -- In an instance, this is a run-time check, but one we know
9464 -- will fail, so generate an appropriate warning. The raise
9465 -- will be generated by Expand_N_Type_Conversion.
9467 if In_Instance_Body then
9469 ("?cannot convert access discriminant to non-local" &
9470 " access type", Operand);
9472 ("\?Program_Error will be raised at run time", Operand);
9475 ("cannot convert access discriminant to non-local" &
9476 " access type", Operand);
9481 -- The case of a reference to an access discriminant from
9482 -- within a limited type declaration (which will appear as
9483 -- a discriminal) is always illegal because the level of the
9484 -- discriminant is considered to be deeper than any (nameable)
9487 if Is_Entity_Name (Operand)
9488 and then not Is_Local_Anonymous_Access (Opnd_Type)
9489 and then (Ekind (Entity (Operand)) = E_In_Parameter
9490 or else Ekind (Entity (Operand)) = E_Constant)
9491 and then Present (Discriminal_Link (Entity (Operand)))
9494 ("discriminant has deeper accessibility level than target",
9503 -- General and anonymous access types
9505 elsif (Ekind (Target_Type) = E_General_Access_Type
9506 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9509 (Is_Access_Type (Opnd_Type)
9510 and then Ekind (Opnd_Type) /=
9511 E_Access_Subprogram_Type
9512 and then Ekind (Opnd_Type) /=
9513 E_Access_Protected_Subprogram_Type,
9514 "must be an access-to-object type")
9516 if Is_Access_Constant (Opnd_Type)
9517 and then not Is_Access_Constant (Target_Type)
9520 ("access-to-constant operand type not allowed", Operand);
9524 -- Check the static accessibility rule of 4.6(17). Note that the
9525 -- check is not enforced when within an instance body, since the RM
9526 -- requires such cases to be caught at run time.
9528 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9529 or else Is_Local_Anonymous_Access (Target_Type)
9531 if Type_Access_Level (Opnd_Type)
9532 > Type_Access_Level (Target_Type)
9534 -- In an instance, this is a run-time check, but one we know
9535 -- will fail, so generate an appropriate warning. The raise
9536 -- will be generated by Expand_N_Type_Conversion.
9538 if In_Instance_Body then
9540 ("?cannot convert local pointer to non-local access type",
9543 ("\?Program_Error will be raised at run time", Operand);
9546 -- Avoid generation of spurious error message
9548 if not Error_Posted (N) then
9550 ("cannot convert local pointer to non-local access type",
9557 -- Special accessibility checks are needed in the case of access
9558 -- discriminants declared for a limited type.
9560 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9561 and then not Is_Local_Anonymous_Access (Opnd_Type)
9564 -- When the operand is a selected access discriminant the check
9565 -- needs to be made against the level of the object denoted by
9566 -- the prefix of the selected name (Object_Access_Level handles
9567 -- checking the prefix of the operand for this case).
9569 if Nkind (Operand) = N_Selected_Component
9570 and then Object_Access_Level (Operand) >
9571 Type_Access_Level (Target_Type)
9573 -- In an instance, this is a run-time check, but one we know
9574 -- will fail, so generate an appropriate warning. The raise
9575 -- will be generated by Expand_N_Type_Conversion.
9577 if In_Instance_Body then
9579 ("?cannot convert access discriminant to non-local" &
9580 " access type", Operand);
9582 ("\?Program_Error will be raised at run time",
9587 ("cannot convert access discriminant to non-local" &
9588 " access type", Operand);
9593 -- The case of a reference to an access discriminant from
9594 -- within a limited type declaration (which will appear as
9595 -- a discriminal) is always illegal because the level of the
9596 -- discriminant is considered to be deeper than any (nameable)
9599 if Is_Entity_Name (Operand)
9600 and then (Ekind (Entity (Operand)) = E_In_Parameter
9601 or else Ekind (Entity (Operand)) = E_Constant)
9602 and then Present (Discriminal_Link (Entity (Operand)))
9605 ("discriminant has deeper accessibility level than target",
9612 -- Need some comments here, and a name for this block ???
9615 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9616 -- Helper function to handle limited views
9618 --------------------------
9619 -- Full_Designated_Type --
9620 --------------------------
9622 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9623 Desig : Entity_Id := Designated_Type (T);
9626 -- Detect a legal use of a shadow entity
9628 if Is_Incomplete_Type (Desig)
9629 and then From_With_Type (Desig)
9630 and then Present (Non_Limited_View (Desig))
9631 and then Is_Legal_Shadow_Entity_In_Body (Desig)
9633 Desig := Non_Limited_View (Desig);
9636 return Available_View (Desig);
9637 end Full_Designated_Type;
9639 -- Local Declarations
9641 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9642 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9644 Same_Base : constant Boolean :=
9645 Base_Type (Target) = Base_Type (Opnd);
9647 -- Start of processing for ???
9650 if Is_Tagged_Type (Target) then
9651 return Valid_Tagged_Conversion (Target, Opnd);
9654 if not Same_Base then
9656 ("target designated type not compatible with }",
9657 N, Base_Type (Opnd));
9660 -- Ada 2005 AI-384: legality rule is symmetric in both
9661 -- designated types. The conversion is legal (with possible
9662 -- constraint check) if either designated type is
9665 elsif Subtypes_Statically_Match (Target, Opnd)
9667 (Has_Discriminants (Target)
9669 (not Is_Constrained (Opnd)
9670 or else not Is_Constrained (Target)))
9672 -- Special case, if Value_Size has been used to make the
9673 -- sizes different, the conversion is not allowed even
9674 -- though the subtypes statically match.
9676 if Known_Static_RM_Size (Target)
9677 and then Known_Static_RM_Size (Opnd)
9678 and then RM_Size (Target) /= RM_Size (Opnd)
9681 ("target designated subtype not compatible with }",
9684 ("\because sizes of the two designated subtypes differ",
9688 -- Normal case where conversion is allowed
9696 ("target designated subtype not compatible with }",
9703 -- Access to subprogram types. If the operand is an access parameter,
9704 -- the type has a deeper accessibility that any master, and cannot
9705 -- be assigned. We must make an exception if the conversion is part
9706 -- of an assignment and the target is the return object of an extended
9707 -- return statement, because in that case the accessibility check
9708 -- takes place after the return.
9710 elsif Is_Access_Subprogram_Type (Target_Type)
9711 and then No (Corresponding_Remote_Type (Opnd_Type))
9713 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9714 and then Is_Entity_Name (Operand)
9715 and then Ekind (Entity (Operand)) = E_In_Parameter
9717 (Nkind (Parent (N)) /= N_Assignment_Statement
9718 or else not Is_Entity_Name (Name (Parent (N)))
9719 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9722 ("illegal attempt to store anonymous access to subprogram",
9725 ("\value has deeper accessibility than any master " &
9730 ("\use named access type for& instead of access parameter",
9731 Operand, Entity (Operand));
9734 -- Check that the designated types are subtype conformant
9736 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9737 Old_Id => Designated_Type (Opnd_Type),
9740 -- Check the static accessibility rule of 4.6(20)
9742 if Type_Access_Level (Opnd_Type) >
9743 Type_Access_Level (Target_Type)
9746 ("operand type has deeper accessibility level than target",
9749 -- Check that if the operand type is declared in a generic body,
9750 -- then the target type must be declared within that same body
9751 -- (enforces last sentence of 4.6(20)).
9753 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9755 O_Gen : constant Node_Id :=
9756 Enclosing_Generic_Body (Opnd_Type);
9761 T_Gen := Enclosing_Generic_Body (Target_Type);
9762 while Present (T_Gen) and then T_Gen /= O_Gen loop
9763 T_Gen := Enclosing_Generic_Body (T_Gen);
9766 if T_Gen /= O_Gen then
9768 ("target type must be declared in same generic body"
9769 & " as operand type", N);
9776 -- Remote subprogram access types
9778 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9779 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9781 -- It is valid to convert from one RAS type to another provided
9782 -- that their specification statically match.
9784 Check_Subtype_Conformant
9786 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9788 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9793 -- If both are tagged types, check legality of view conversions
9795 elsif Is_Tagged_Type (Target_Type)
9796 and then Is_Tagged_Type (Opnd_Type)
9798 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9800 -- Types derived from the same root type are convertible
9802 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9805 -- In an instance or an inlined body, there may be inconsistent
9806 -- views of the same type, or of types derived from a common root.
9808 elsif (In_Instance or In_Inlined_Body)
9810 Root_Type (Underlying_Type (Target_Type)) =
9811 Root_Type (Underlying_Type (Opnd_Type))
9815 -- Special check for common access type error case
9817 elsif Ekind (Target_Type) = E_Access_Type
9818 and then Is_Access_Type (Opnd_Type)
9820 Error_Msg_N ("target type must be general access type!", N);
9821 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9825 Error_Msg_NE ("invalid conversion, not compatible with }",
9829 end Valid_Conversion;