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_Ch13; use Sem_Ch13;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Elim; use Sem_Elim;
64 with Sem_Elab; use Sem_Elab;
65 with Sem_Eval; use Sem_Eval;
66 with Sem_Intr; use Sem_Intr;
67 with Sem_Util; use Sem_Util;
68 with Sem_Type; use Sem_Type;
69 with Sem_Warn; use Sem_Warn;
70 with Sinfo; use Sinfo;
71 with Snames; use Snames;
72 with Stand; use Stand;
73 with Stringt; use Stringt;
74 with Style; use Style;
75 with Tbuild; use Tbuild;
76 with Uintp; use Uintp;
77 with Urealp; use Urealp;
79 package body Sem_Res is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the
87 -- type information recursively to the descendants of N. If the node
88 -- is not overloaded, its Etype is established in the first pass. If
89 -- overloaded, the Resolve routines set the correct type. For arith.
90 -- operators, the Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 procedure Check_Discriminant_Use (N : Node_Id);
95 -- Enforce the restrictions on the use of discriminants when constraining
96 -- a component of a discriminated type (record or concurrent type).
98 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
99 -- Given a node for an operator associated with type T, check that
100 -- the operator is visible. Operators all of whose operands are
101 -- universal must be checked for visibility during resolution
102 -- because their type is not determinable based on their operands.
104 procedure Check_Fully_Declared_Prefix
107 -- Check that the type of the prefix of a dereference is not incomplete
109 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
110 -- Given a call node, N, which is known to occur immediately within the
111 -- subprogram being called, determines whether it is a detectable case of
112 -- an infinite recursion, and if so, outputs appropriate messages. Returns
113 -- True if an infinite recursion is detected, and False otherwise.
115 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
116 -- If the type of the object being initialized uses the secondary stack
117 -- directly or indirectly, create a transient scope for the call to the
118 -- init proc. This is because we do not create transient scopes for the
119 -- initialization of individual components within the init proc itself.
120 -- Could be optimized away perhaps?
122 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
123 -- N is the node for a logical operator. If the operator is predefined, and
124 -- the root type of the operands is Standard.Boolean, then a check is made
125 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
126 -- the style check for Style_Check_Boolean_And_Or.
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 Is_Access_Type (Etype (Pref))
680 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
682 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
686 Check_Fully_Declared (Typ, Parent (Pref));
688 end Check_Fully_Declared_Prefix;
690 ------------------------------
691 -- Check_Infinite_Recursion --
692 ------------------------------
694 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
698 function Same_Argument_List return Boolean;
699 -- Check whether list of actuals is identical to list of formals
700 -- of called function (which is also the enclosing scope).
702 ------------------------
703 -- Same_Argument_List --
704 ------------------------
706 function Same_Argument_List return Boolean is
712 if not Is_Entity_Name (Name (N)) then
715 Subp := Entity (Name (N));
718 F := First_Formal (Subp);
719 A := First_Actual (N);
720 while Present (F) and then Present (A) loop
721 if not Is_Entity_Name (A)
722 or else Entity (A) /= F
732 end Same_Argument_List;
734 -- Start of processing for Check_Infinite_Recursion
737 -- Special case, if this is a procedure call and is a call to the
738 -- current procedure with the same argument list, then this is for
739 -- sure an infinite recursion and we insert a call to raise SE.
741 if Is_List_Member (N)
742 and then List_Length (List_Containing (N)) = 1
743 and then Same_Argument_List
746 P : constant Node_Id := Parent (N);
748 if Nkind (P) = N_Handled_Sequence_Of_Statements
749 and then Nkind (Parent (P)) = N_Subprogram_Body
750 and then Is_Empty_List (Declarations (Parent (P)))
752 Error_Msg_N ("!?infinite recursion", N);
753 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
755 Make_Raise_Storage_Error (Sloc (N),
756 Reason => SE_Infinite_Recursion));
762 -- If not that special case, search up tree, quitting if we reach a
763 -- construct (e.g. a conditional) that tells us that this is not a
764 -- case for an infinite recursion warning.
770 -- If no parent, then we were not inside a subprogram, this can for
771 -- example happen when processing certain pragmas in a spec. Just
772 -- return False in this case.
778 -- Done if we get to subprogram body, this is definitely an infinite
779 -- recursion case if we did not find anything to stop us.
781 exit when Nkind (P) = N_Subprogram_Body;
783 -- If appearing in conditional, result is false
785 if Nkind_In (P, N_Or_Else,
792 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
793 and then C /= First (Statements (P))
795 -- If the call is the expression of a return statement and the
796 -- actuals are identical to the formals, it's worth a warning.
797 -- However, we skip this if there is an immediately preceding
798 -- raise statement, since the call is never executed.
800 -- Furthermore, this corresponds to a common idiom:
802 -- function F (L : Thing) return Boolean is
804 -- raise Program_Error;
808 -- for generating a stub function
810 if Nkind (Parent (N)) = N_Simple_Return_Statement
811 and then Same_Argument_List
813 exit when not Is_List_Member (Parent (N));
815 -- OK, return statement is in a statement list, look for raise
821 -- Skip past N_Freeze_Entity nodes generated by expansion
823 Nod := Prev (Parent (N));
825 and then Nkind (Nod) = N_Freeze_Entity
830 -- If no raise statement, give warning
832 exit when Nkind (Nod) /= N_Raise_Statement
834 (Nkind (Nod) not in N_Raise_xxx_Error
835 or else Present (Condition (Nod)));
846 Error_Msg_N ("!?possible infinite recursion", N);
847 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
850 end Check_Infinite_Recursion;
852 -------------------------------
853 -- Check_Initialization_Call --
854 -------------------------------
856 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
857 Typ : constant Entity_Id := Etype (First_Formal (Nam));
859 function Uses_SS (T : Entity_Id) return Boolean;
860 -- Check whether the creation of an object of the type will involve
861 -- use of the secondary stack. If T is a record type, this is true
862 -- if the expression for some component uses the secondary stack, e.g.
863 -- through a call to a function that returns an unconstrained value.
864 -- False if T is controlled, because cleanups occur elsewhere.
870 function Uses_SS (T : Entity_Id) return Boolean is
873 Full_Type : Entity_Id := Underlying_Type (T);
876 -- Normally we want to use the underlying type, but if it's not set
877 -- then continue with T.
879 if not Present (Full_Type) then
883 if Is_Controlled (Full_Type) then
886 elsif Is_Array_Type (Full_Type) then
887 return Uses_SS (Component_Type (Full_Type));
889 elsif Is_Record_Type (Full_Type) then
890 Comp := First_Component (Full_Type);
891 while Present (Comp) loop
892 if Ekind (Comp) = E_Component
893 and then Nkind (Parent (Comp)) = N_Component_Declaration
895 -- The expression for a dynamic component may be rewritten
896 -- as a dereference, so retrieve original node.
898 Expr := Original_Node (Expression (Parent (Comp)));
900 -- Return True if the expression is a call to a function
901 -- (including an attribute function such as Image) with
902 -- a result that requires a transient scope.
904 if (Nkind (Expr) = N_Function_Call
905 or else (Nkind (Expr) = N_Attribute_Reference
906 and then Present (Expressions (Expr))))
907 and then Requires_Transient_Scope (Etype (Expr))
911 elsif Uses_SS (Etype (Comp)) then
916 Next_Component (Comp);
926 -- Start of processing for Check_Initialization_Call
929 -- Establish a transient scope if the type needs it
931 if Uses_SS (Typ) then
932 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
934 end Check_Initialization_Call;
936 ---------------------------------------
937 -- Check_No_Direct_Boolean_Operators --
938 ---------------------------------------
940 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
942 if Scope (Entity (N)) = Standard_Standard
943 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
945 -- Restriction only applies to original source code
947 if Comes_From_Source (N) then
948 Check_Restriction (No_Direct_Boolean_Operators, N);
953 Check_Boolean_Operator (N);
955 end Check_No_Direct_Boolean_Operators;
957 ------------------------------
958 -- Check_Parameterless_Call --
959 ------------------------------
961 procedure Check_Parameterless_Call (N : Node_Id) is
964 function Prefix_Is_Access_Subp return Boolean;
965 -- If the prefix is of an access_to_subprogram type, the node must be
966 -- rewritten as a call. Ditto if the prefix is overloaded and all its
967 -- interpretations are access to subprograms.
969 ---------------------------
970 -- Prefix_Is_Access_Subp --
971 ---------------------------
973 function Prefix_Is_Access_Subp return Boolean is
978 if not Is_Overloaded (N) then
980 Ekind (Etype (N)) = E_Subprogram_Type
981 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
983 Get_First_Interp (N, I, It);
984 while Present (It.Typ) loop
985 if Ekind (It.Typ) /= E_Subprogram_Type
986 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
991 Get_Next_Interp (I, It);
996 end Prefix_Is_Access_Subp;
998 -- Start of processing for Check_Parameterless_Call
1001 -- Defend against junk stuff if errors already detected
1003 if Total_Errors_Detected /= 0 then
1004 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1006 elsif Nkind (N) in N_Has_Chars
1007 and then Chars (N) in Error_Name_Or_No_Name
1015 -- If the context expects a value, and the name is a procedure, this is
1016 -- most likely a missing 'Access. Don't try to resolve the parameterless
1017 -- call, error will be caught when the outer call is analyzed.
1019 if Is_Entity_Name (N)
1020 and then Ekind (Entity (N)) = E_Procedure
1021 and then not Is_Overloaded (N)
1023 Nkind_In (Parent (N), N_Parameter_Association,
1025 N_Procedure_Call_Statement)
1030 -- Rewrite as call if overloadable entity that is (or could be, in the
1031 -- overloaded case) a function call. If we know for sure that the entity
1032 -- is an enumeration literal, we do not rewrite it.
1034 if (Is_Entity_Name (N)
1035 and then Is_Overloadable (Entity (N))
1036 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1037 or else Is_Overloaded (N)))
1039 -- Rewrite as call if it is an explicit dereference of an expression of
1040 -- a subprogram access type, and the subprogram type is not that of a
1041 -- procedure or entry.
1044 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1046 -- Rewrite as call if it is a selected component which is a function,
1047 -- this is the case of a call to a protected function (which may be
1048 -- overloaded with other protected operations).
1051 (Nkind (N) = N_Selected_Component
1052 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1054 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1056 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1057 and then Is_Overloaded (Selector_Name (N)))))
1059 -- If one of the above three conditions is met, rewrite as call.
1060 -- Apply the rewriting only once.
1063 if Nkind (Parent (N)) /= N_Function_Call
1064 or else N /= Name (Parent (N))
1066 Nam := New_Copy (N);
1068 -- If overloaded, overload set belongs to new copy
1070 Save_Interps (N, Nam);
1072 -- Change node to parameterless function call (note that the
1073 -- Parameter_Associations associations field is left set to Empty,
1074 -- its normal default value since there are no parameters)
1076 Change_Node (N, N_Function_Call);
1078 Set_Sloc (N, Sloc (Nam));
1082 elsif Nkind (N) = N_Parameter_Association then
1083 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1085 end Check_Parameterless_Call;
1087 -----------------------------
1088 -- Is_Definite_Access_Type --
1089 -----------------------------
1091 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1092 Btyp : constant Entity_Id := Base_Type (E);
1094 return Ekind (Btyp) = E_Access_Type
1095 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1096 and then Comes_From_Source (Btyp));
1097 end Is_Definite_Access_Type;
1099 ----------------------
1100 -- Is_Predefined_Op --
1101 ----------------------
1103 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1105 return Is_Intrinsic_Subprogram (Nam)
1106 and then not Is_Generic_Instance (Nam)
1107 and then Chars (Nam) in Any_Operator_Name
1108 and then (No (Alias (Nam))
1109 or else Is_Predefined_Op (Alias (Nam)));
1110 end Is_Predefined_Op;
1112 -----------------------------
1113 -- Make_Call_Into_Operator --
1114 -----------------------------
1116 procedure Make_Call_Into_Operator
1121 Op_Name : constant Name_Id := Chars (Op_Id);
1122 Act1 : Node_Id := First_Actual (N);
1123 Act2 : Node_Id := Next_Actual (Act1);
1124 Error : Boolean := False;
1125 Func : constant Entity_Id := Entity (Name (N));
1126 Is_Binary : constant Boolean := Present (Act2);
1128 Opnd_Type : Entity_Id;
1129 Orig_Type : Entity_Id := Empty;
1132 type Kind_Test is access function (E : Entity_Id) return Boolean;
1134 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1135 -- If the operand is not universal, and the operator is given by a
1136 -- expanded name, verify that the operand has an interpretation with
1137 -- a type defined in the given scope of the operator.
1139 function Type_In_P (Test : Kind_Test) return Entity_Id;
1140 -- Find a type of the given class in the package Pack that contains
1143 ---------------------------
1144 -- Operand_Type_In_Scope --
1145 ---------------------------
1147 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1148 Nod : constant Node_Id := Right_Opnd (Op_Node);
1153 if not Is_Overloaded (Nod) then
1154 return Scope (Base_Type (Etype (Nod))) = S;
1157 Get_First_Interp (Nod, I, It);
1158 while Present (It.Typ) loop
1159 if Scope (Base_Type (It.Typ)) = S then
1163 Get_Next_Interp (I, It);
1168 end Operand_Type_In_Scope;
1174 function Type_In_P (Test : Kind_Test) return Entity_Id is
1177 function In_Decl return Boolean;
1178 -- Verify that node is not part of the type declaration for the
1179 -- candidate type, which would otherwise be invisible.
1185 function In_Decl return Boolean is
1186 Decl_Node : constant Node_Id := Parent (E);
1192 if Etype (E) = Any_Type then
1195 elsif No (Decl_Node) then
1200 and then Nkind (N2) /= N_Compilation_Unit
1202 if N2 = Decl_Node then
1213 -- Start of processing for Type_In_P
1216 -- If the context type is declared in the prefix package, this
1217 -- is the desired base type.
1219 if Scope (Base_Type (Typ)) = Pack
1222 return Base_Type (Typ);
1225 E := First_Entity (Pack);
1226 while Present (E) loop
1228 and then not In_Decl
1240 -- Start of processing for Make_Call_Into_Operator
1243 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1248 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1249 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1250 Save_Interps (Act1, Left_Opnd (Op_Node));
1251 Save_Interps (Act2, Right_Opnd (Op_Node));
1252 Act1 := Left_Opnd (Op_Node);
1253 Act2 := Right_Opnd (Op_Node);
1258 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1259 Save_Interps (Act1, Right_Opnd (Op_Node));
1260 Act1 := Right_Opnd (Op_Node);
1263 -- If the operator is denoted by an expanded name, and the prefix is
1264 -- not Standard, but the operator is a predefined one whose scope is
1265 -- Standard, then this is an implicit_operator, inserted as an
1266 -- interpretation by the procedure of the same name. This procedure
1267 -- overestimates the presence of implicit operators, because it does
1268 -- not examine the type of the operands. Verify now that the operand
1269 -- type appears in the given scope. If right operand is universal,
1270 -- check the other operand. In the case of concatenation, either
1271 -- argument can be the component type, so check the type of the result.
1272 -- If both arguments are literals, look for a type of the right kind
1273 -- defined in the given scope. This elaborate nonsense is brought to
1274 -- you courtesy of b33302a. The type itself must be frozen, so we must
1275 -- find the type of the proper class in the given scope.
1277 -- A final wrinkle is the multiplication operator for fixed point
1278 -- types, which is defined in Standard only, and not in the scope of
1279 -- the fixed_point type itself.
1281 if Nkind (Name (N)) = N_Expanded_Name then
1282 Pack := Entity (Prefix (Name (N)));
1284 -- If the entity being called is defined in the given package,
1285 -- it is a renaming of a predefined operator, and known to be
1288 if Scope (Entity (Name (N))) = Pack
1289 and then Pack /= Standard_Standard
1293 -- Visibility does not need to be checked in an instance: if the
1294 -- operator was not visible in the generic it has been diagnosed
1295 -- already, else there is an implicit copy of it in the instance.
1297 elsif In_Instance then
1300 elsif (Op_Name = Name_Op_Multiply
1301 or else Op_Name = Name_Op_Divide)
1302 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1303 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1305 if Pack /= Standard_Standard then
1309 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1312 elsif Ada_Version >= Ada_05
1313 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1314 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1319 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1321 if Op_Name = Name_Op_Concat then
1322 Opnd_Type := Base_Type (Typ);
1324 elsif (Scope (Opnd_Type) = Standard_Standard
1326 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1328 and then not Comes_From_Source (Opnd_Type))
1330 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1333 if Scope (Opnd_Type) = Standard_Standard then
1335 -- Verify that the scope contains a type that corresponds to
1336 -- the given literal. Optimize the case where Pack is Standard.
1338 if Pack /= Standard_Standard then
1340 if Opnd_Type = Universal_Integer then
1341 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1343 elsif Opnd_Type = Universal_Real then
1344 Orig_Type := Type_In_P (Is_Real_Type'Access);
1346 elsif Opnd_Type = Any_String then
1347 Orig_Type := Type_In_P (Is_String_Type'Access);
1349 elsif Opnd_Type = Any_Access then
1350 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1352 elsif Opnd_Type = Any_Composite then
1353 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1355 if Present (Orig_Type) then
1356 if Has_Private_Component (Orig_Type) then
1359 Set_Etype (Act1, Orig_Type);
1362 Set_Etype (Act2, Orig_Type);
1371 Error := No (Orig_Type);
1374 elsif Ekind (Opnd_Type) = E_Allocator_Type
1375 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1379 -- If the type is defined elsewhere, and the operator is not
1380 -- defined in the given scope (by a renaming declaration, e.g.)
1381 -- then this is an error as well. If an extension of System is
1382 -- present, and the type may be defined there, Pack must be
1385 elsif Scope (Opnd_Type) /= Pack
1386 and then Scope (Op_Id) /= Pack
1387 and then (No (System_Aux_Id)
1388 or else Scope (Opnd_Type) /= System_Aux_Id
1389 or else Pack /= Scope (System_Aux_Id))
1391 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1394 Error := not Operand_Type_In_Scope (Pack);
1397 elsif Pack = Standard_Standard
1398 and then not Operand_Type_In_Scope (Standard_Standard)
1405 Error_Msg_Node_2 := Pack;
1407 ("& not declared in&", N, Selector_Name (Name (N)));
1408 Set_Etype (N, Any_Type);
1413 Set_Chars (Op_Node, Op_Name);
1415 if not Is_Private_Type (Etype (N)) then
1416 Set_Etype (Op_Node, Base_Type (Etype (N)));
1418 Set_Etype (Op_Node, Etype (N));
1421 -- If this is a call to a function that renames a predefined equality,
1422 -- the renaming declaration provides a type that must be used to
1423 -- resolve the operands. This must be done now because resolution of
1424 -- the equality node will not resolve any remaining ambiguity, and it
1425 -- assumes that the first operand is not overloaded.
1427 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1428 and then Ekind (Func) = E_Function
1429 and then Is_Overloaded (Act1)
1431 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1432 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1435 Set_Entity (Op_Node, Op_Id);
1436 Generate_Reference (Op_Id, N, ' ');
1438 -- Do rewrite setting Comes_From_Source on the result if the original
1439 -- call came from source. Although it is not strictly the case that the
1440 -- operator as such comes from the source, logically it corresponds
1441 -- exactly to the function call in the source, so it should be marked
1442 -- this way (e.g. to make sure that validity checks work fine).
1445 CS : constant Boolean := Comes_From_Source (N);
1447 Rewrite (N, Op_Node);
1448 Set_Comes_From_Source (N, CS);
1451 -- If this is an arithmetic operator and the result type is private,
1452 -- the operands and the result must be wrapped in conversion to
1453 -- expose the underlying numeric type and expand the proper checks,
1454 -- e.g. on division.
1456 if Is_Private_Type (Typ) then
1458 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1459 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1460 Resolve_Intrinsic_Operator (N, Typ);
1462 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1463 Resolve_Intrinsic_Unary_Operator (N, Typ);
1472 -- For predefined operators on literals, the operation freezes
1475 if Present (Orig_Type) then
1476 Set_Etype (Act1, Orig_Type);
1477 Freeze_Expression (Act1);
1479 end Make_Call_Into_Operator;
1485 function Operator_Kind
1487 Is_Binary : Boolean) return Node_Kind
1493 if Op_Name = Name_Op_And then
1495 elsif Op_Name = Name_Op_Or then
1497 elsif Op_Name = Name_Op_Xor then
1499 elsif Op_Name = Name_Op_Eq then
1501 elsif Op_Name = Name_Op_Ne then
1503 elsif Op_Name = Name_Op_Lt then
1505 elsif Op_Name = Name_Op_Le then
1507 elsif Op_Name = Name_Op_Gt then
1509 elsif Op_Name = Name_Op_Ge then
1511 elsif Op_Name = Name_Op_Add then
1513 elsif Op_Name = Name_Op_Subtract then
1514 Kind := N_Op_Subtract;
1515 elsif Op_Name = Name_Op_Concat then
1516 Kind := N_Op_Concat;
1517 elsif Op_Name = Name_Op_Multiply then
1518 Kind := N_Op_Multiply;
1519 elsif Op_Name = Name_Op_Divide then
1520 Kind := N_Op_Divide;
1521 elsif Op_Name = Name_Op_Mod then
1523 elsif Op_Name = Name_Op_Rem then
1525 elsif Op_Name = Name_Op_Expon then
1528 raise Program_Error;
1534 if Op_Name = Name_Op_Add then
1536 elsif Op_Name = Name_Op_Subtract then
1538 elsif Op_Name = Name_Op_Abs then
1540 elsif Op_Name = Name_Op_Not then
1543 raise Program_Error;
1550 ----------------------------
1551 -- Preanalyze_And_Resolve --
1552 ----------------------------
1554 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1555 Save_Full_Analysis : constant Boolean := Full_Analysis;
1558 Full_Analysis := False;
1559 Expander_Mode_Save_And_Set (False);
1561 -- We suppress all checks for this analysis, since the checks will
1562 -- be applied properly, and in the right location, when the default
1563 -- expression is reanalyzed and reexpanded later on.
1565 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1567 Expander_Mode_Restore;
1568 Full_Analysis := Save_Full_Analysis;
1569 end Preanalyze_And_Resolve;
1571 -- Version without context type
1573 procedure Preanalyze_And_Resolve (N : Node_Id) is
1574 Save_Full_Analysis : constant Boolean := Full_Analysis;
1577 Full_Analysis := False;
1578 Expander_Mode_Save_And_Set (False);
1581 Resolve (N, Etype (N), Suppress => All_Checks);
1583 Expander_Mode_Restore;
1584 Full_Analysis := Save_Full_Analysis;
1585 end Preanalyze_And_Resolve;
1587 ----------------------------------
1588 -- Replace_Actual_Discriminants --
1589 ----------------------------------
1591 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1592 Loc : constant Source_Ptr := Sloc (N);
1593 Tsk : Node_Id := Empty;
1595 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1601 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1605 if Nkind (Nod) = N_Identifier then
1606 Ent := Entity (Nod);
1609 and then Ekind (Ent) = E_Discriminant
1612 Make_Selected_Component (Loc,
1613 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1614 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1616 Set_Etype (Nod, Etype (Ent));
1624 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1626 -- Start of processing for Replace_Actual_Discriminants
1629 if not Expander_Active then
1633 if Nkind (Name (N)) = N_Selected_Component then
1634 Tsk := Prefix (Name (N));
1636 elsif Nkind (Name (N)) = N_Indexed_Component then
1637 Tsk := Prefix (Prefix (Name (N)));
1643 Replace_Discrs (Default);
1645 end Replace_Actual_Discriminants;
1651 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1652 Ambiguous : Boolean := False;
1653 Ctx_Type : Entity_Id := Typ;
1654 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1655 Err_Type : Entity_Id := Empty;
1656 Found : Boolean := False;
1659 I1 : Interp_Index := 0; -- prevent junk warning
1662 Seen : Entity_Id := Empty; -- prevent junk warning
1664 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1665 -- Determine whether a node comes from a predefined library unit or
1668 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1669 -- Try and fix up a literal so that it matches its expected type. New
1670 -- literals are manufactured if necessary to avoid cascaded errors.
1672 procedure Report_Ambiguous_Argument;
1673 -- Additional diagnostics when an ambiguous call has an ambiguous
1674 -- argument (typically a controlling actual).
1676 procedure Resolution_Failed;
1677 -- Called when attempt at resolving current expression fails
1679 ------------------------------------
1680 -- Comes_From_Predefined_Lib_Unit --
1681 -------------------------------------
1683 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1686 Sloc (Nod) = Standard_Location
1687 or else Is_Predefined_File_Name (Unit_File_Name (
1688 Get_Source_Unit (Sloc (Nod))));
1689 end Comes_From_Predefined_Lib_Unit;
1691 --------------------
1692 -- Patch_Up_Value --
1693 --------------------
1695 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1697 if Nkind (N) = N_Integer_Literal
1698 and then Is_Real_Type (Typ)
1701 Make_Real_Literal (Sloc (N),
1702 Realval => UR_From_Uint (Intval (N))));
1703 Set_Etype (N, Universal_Real);
1704 Set_Is_Static_Expression (N);
1706 elsif Nkind (N) = N_Real_Literal
1707 and then Is_Integer_Type (Typ)
1710 Make_Integer_Literal (Sloc (N),
1711 Intval => UR_To_Uint (Realval (N))));
1712 Set_Etype (N, Universal_Integer);
1713 Set_Is_Static_Expression (N);
1715 elsif Nkind (N) = N_String_Literal
1716 and then Is_Character_Type (Typ)
1718 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1720 Make_Character_Literal (Sloc (N),
1722 Char_Literal_Value =>
1723 UI_From_Int (Character'Pos ('A'))));
1724 Set_Etype (N, Any_Character);
1725 Set_Is_Static_Expression (N);
1727 elsif Nkind (N) /= N_String_Literal
1728 and then Is_String_Type (Typ)
1731 Make_String_Literal (Sloc (N),
1732 Strval => End_String));
1734 elsif Nkind (N) = N_Range then
1735 Patch_Up_Value (Low_Bound (N), Typ);
1736 Patch_Up_Value (High_Bound (N), Typ);
1740 -------------------------------
1741 -- Report_Ambiguous_Argument --
1742 -------------------------------
1744 procedure Report_Ambiguous_Argument is
1745 Arg : constant Node_Id := First (Parameter_Associations (N));
1750 if Nkind (Arg) = N_Function_Call
1751 and then Is_Entity_Name (Name (Arg))
1752 and then Is_Overloaded (Name (Arg))
1754 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1756 Get_First_Interp (Name (Arg), I, It);
1757 while Present (It.Nam) loop
1758 Error_Msg_Sloc := Sloc (It.Nam);
1760 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1761 Error_Msg_N ("interpretation (inherited) #!", Arg);
1764 Error_Msg_N ("interpretation #!", Arg);
1767 Get_Next_Interp (I, It);
1770 end Report_Ambiguous_Argument;
1772 -----------------------
1773 -- Resolution_Failed --
1774 -----------------------
1776 procedure Resolution_Failed is
1778 Patch_Up_Value (N, Typ);
1780 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1781 Set_Is_Overloaded (N, False);
1783 -- The caller will return without calling the expander, so we need
1784 -- to set the analyzed flag. Note that it is fine to set Analyzed
1785 -- to True even if we are in the middle of a shallow analysis,
1786 -- (see the spec of sem for more details) since this is an error
1787 -- situation anyway, and there is no point in repeating the
1788 -- analysis later (indeed it won't work to repeat it later, since
1789 -- we haven't got a clear resolution of which entity is being
1792 Set_Analyzed (N, True);
1794 end Resolution_Failed;
1796 -- Start of processing for Resolve
1803 -- Access attribute on remote subprogram cannot be used for
1804 -- a non-remote access-to-subprogram type.
1806 if Nkind (N) = N_Attribute_Reference
1807 and then (Attribute_Name (N) = Name_Access
1808 or else Attribute_Name (N) = Name_Unrestricted_Access
1809 or else Attribute_Name (N) = Name_Unchecked_Access)
1810 and then Comes_From_Source (N)
1811 and then Is_Entity_Name (Prefix (N))
1812 and then Is_Subprogram (Entity (Prefix (N)))
1813 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1814 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1817 ("prefix must statically denote a non-remote subprogram", N);
1820 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1822 -- If the context is a Remote_Access_To_Subprogram, access attributes
1823 -- must be resolved with the corresponding fat pointer. There is no need
1824 -- to check for the attribute name since the return type of an
1825 -- attribute is never a remote type.
1827 if Nkind (N) = N_Attribute_Reference
1828 and then Comes_From_Source (N)
1829 and then (Is_Remote_Call_Interface (Typ)
1830 or else Is_Remote_Types (Typ))
1833 Attr : constant Attribute_Id :=
1834 Get_Attribute_Id (Attribute_Name (N));
1835 Pref : constant Node_Id := Prefix (N);
1838 Is_Remote : Boolean := True;
1841 -- Check that Typ is a remote access-to-subprogram type
1843 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1844 -- Prefix (N) must statically denote a remote subprogram
1845 -- declared in a package specification.
1847 if Attr = Attribute_Access then
1848 Decl := Unit_Declaration_Node (Entity (Pref));
1850 if Nkind (Decl) = N_Subprogram_Body then
1851 Spec := Corresponding_Spec (Decl);
1853 if not No (Spec) then
1854 Decl := Unit_Declaration_Node (Spec);
1858 Spec := Parent (Decl);
1860 if not Is_Entity_Name (Prefix (N))
1861 or else Nkind (Spec) /= N_Package_Specification
1863 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1867 ("prefix must statically denote a remote subprogram ",
1872 -- If we are generating code for a distributed program.
1873 -- perform semantic checks against the corresponding
1876 if (Attr = Attribute_Access
1877 or else Attr = Attribute_Unchecked_Access
1878 or else Attr = Attribute_Unrestricted_Access)
1879 and then Expander_Active
1880 and then Get_PCS_Name /= Name_No_DSA
1882 Check_Subtype_Conformant
1883 (New_Id => Entity (Prefix (N)),
1884 Old_Id => Designated_Type
1885 (Corresponding_Remote_Type (Typ)),
1889 Process_Remote_AST_Attribute (N, Typ);
1896 Debug_A_Entry ("resolving ", N);
1898 if Comes_From_Source (N) then
1899 if Is_Fixed_Point_Type (Typ) then
1900 Check_Restriction (No_Fixed_Point, N);
1902 elsif Is_Floating_Point_Type (Typ)
1903 and then Typ /= Universal_Real
1904 and then Typ /= Any_Real
1906 Check_Restriction (No_Floating_Point, N);
1910 -- Return if already analyzed
1912 if Analyzed (N) then
1913 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1916 -- Return if type = Any_Type (previous error encountered)
1918 elsif Etype (N) = Any_Type then
1919 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1923 Check_Parameterless_Call (N);
1925 -- If not overloaded, then we know the type, and all that needs doing
1926 -- is to check that this type is compatible with the context.
1928 if not Is_Overloaded (N) then
1929 Found := Covers (Typ, Etype (N));
1930 Expr_Type := Etype (N);
1932 -- In the overloaded case, we must select the interpretation that
1933 -- is compatible with the context (i.e. the type passed to Resolve)
1936 -- Loop through possible interpretations
1938 Get_First_Interp (N, I, It);
1939 Interp_Loop : while Present (It.Typ) loop
1941 -- We are only interested in interpretations that are compatible
1942 -- with the expected type, any other interpretations are ignored.
1944 if not Covers (Typ, It.Typ) then
1945 if Debug_Flag_V then
1946 Write_Str (" interpretation incompatible with context");
1951 -- Skip the current interpretation if it is disabled by an
1952 -- abstract operator. This action is performed only when the
1953 -- type against which we are resolving is the same as the
1954 -- type of the interpretation.
1956 if Ada_Version >= Ada_05
1957 and then It.Typ = Typ
1958 and then Typ /= Universal_Integer
1959 and then Typ /= Universal_Real
1960 and then Present (It.Abstract_Op)
1965 -- First matching interpretation
1971 Expr_Type := It.Typ;
1973 -- Matching interpretation that is not the first, maybe an
1974 -- error, but there are some cases where preference rules are
1975 -- used to choose between the two possibilities. These and
1976 -- some more obscure cases are handled in Disambiguate.
1979 -- If the current statement is part of a predefined library
1980 -- unit, then all interpretations which come from user level
1981 -- packages should not be considered.
1984 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1989 Error_Msg_Sloc := Sloc (Seen);
1990 It1 := Disambiguate (N, I1, I, Typ);
1992 -- Disambiguation has succeeded. Skip the remaining
1995 if It1 /= No_Interp then
1997 Expr_Type := It1.Typ;
1999 while Present (It.Typ) loop
2000 Get_Next_Interp (I, It);
2004 -- Before we issue an ambiguity complaint, check for
2005 -- the case of a subprogram call where at least one
2006 -- of the arguments is Any_Type, and if so, suppress
2007 -- the message, since it is a cascaded error.
2009 if Nkind_In (N, N_Function_Call,
2010 N_Procedure_Call_Statement)
2017 A := First_Actual (N);
2018 while Present (A) loop
2021 if Nkind (E) = N_Parameter_Association then
2022 E := Explicit_Actual_Parameter (E);
2025 if Etype (E) = Any_Type then
2026 if Debug_Flag_V then
2027 Write_Str ("Any_Type in call");
2038 elsif Nkind (N) in N_Binary_Op
2039 and then (Etype (Left_Opnd (N)) = Any_Type
2040 or else Etype (Right_Opnd (N)) = Any_Type)
2044 elsif Nkind (N) in N_Unary_Op
2045 and then Etype (Right_Opnd (N)) = Any_Type
2050 -- Not that special case, so issue message using the
2051 -- flag Ambiguous to control printing of the header
2052 -- message only at the start of an ambiguous set.
2054 if not Ambiguous then
2055 if Nkind (N) = N_Function_Call
2056 and then Nkind (Name (N)) = N_Explicit_Dereference
2059 ("ambiguous expression "
2060 & "(cannot resolve indirect call)!", N);
2062 Error_Msg_NE -- CODEFIX
2063 ("ambiguous expression (cannot resolve&)!",
2069 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2071 ("\\possible interpretation (inherited)#!", N);
2073 Error_Msg_N -- CODEFIX
2074 ("\\possible interpretation#!", N);
2078 (N, N_Procedure_Call_Statement, N_Function_Call)
2079 and then Present (Parameter_Associations (N))
2081 Report_Ambiguous_Argument;
2085 Error_Msg_Sloc := Sloc (It.Nam);
2087 -- By default, the error message refers to the candidate
2088 -- interpretation. But if it is a predefined operator, it
2089 -- is implicitly declared at the declaration of the type
2090 -- of the operand. Recover the sloc of that declaration
2091 -- for the error message.
2093 if Nkind (N) in N_Op
2094 and then Scope (It.Nam) = Standard_Standard
2095 and then not Is_Overloaded (Right_Opnd (N))
2096 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2099 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2101 if Comes_From_Source (Err_Type)
2102 and then Present (Parent (Err_Type))
2104 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2107 elsif Nkind (N) in N_Binary_Op
2108 and then Scope (It.Nam) = Standard_Standard
2109 and then not Is_Overloaded (Left_Opnd (N))
2110 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2113 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2115 if Comes_From_Source (Err_Type)
2116 and then Present (Parent (Err_Type))
2118 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2121 -- If this is an indirect call, use the subprogram_type
2122 -- in the message, to have a meaningful location.
2123 -- Indicate as well if this is an inherited operation,
2124 -- created by a type declaration.
2126 elsif Nkind (N) = N_Function_Call
2127 and then Nkind (Name (N)) = N_Explicit_Dereference
2128 and then Is_Type (It.Nam)
2132 Sloc (Associated_Node_For_Itype (Err_Type));
2137 if Nkind (N) in N_Op
2138 and then Scope (It.Nam) = Standard_Standard
2139 and then Present (Err_Type)
2141 -- Special-case the message for universal_fixed
2142 -- operators, which are not declared with the type
2143 -- of the operand, but appear forever in Standard.
2145 if It.Typ = Universal_Fixed
2146 and then Scope (It.Nam) = Standard_Standard
2149 ("\\possible interpretation as " &
2150 "universal_fixed operation " &
2151 "(RM 4.5.5 (19))", N);
2154 ("\\possible interpretation (predefined)#!", N);
2158 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2161 ("\\possible interpretation (inherited)#!", N);
2163 Error_Msg_N -- CODEFIX
2164 ("\\possible interpretation#!", N);
2170 -- We have a matching interpretation, Expr_Type is the type
2171 -- from this interpretation, and Seen is the entity.
2173 -- For an operator, just set the entity name. The type will be
2174 -- set by the specific operator resolution routine.
2176 if Nkind (N) in N_Op then
2177 Set_Entity (N, Seen);
2178 Generate_Reference (Seen, N);
2180 elsif Nkind (N) = N_Character_Literal then
2181 Set_Etype (N, Expr_Type);
2183 elsif Nkind (N) = N_Conditional_Expression then
2184 Set_Etype (N, Expr_Type);
2186 -- For an explicit dereference, attribute reference, range,
2187 -- short-circuit form (which is not an operator node), or call
2188 -- with a name that is an explicit dereference, there is
2189 -- nothing to be done at this point.
2191 elsif Nkind_In (N, N_Explicit_Dereference,
2192 N_Attribute_Reference,
2194 N_Indexed_Component,
2197 N_Selected_Component,
2199 or else Nkind (Name (N)) = N_Explicit_Dereference
2203 -- For procedure or function calls, set the type of the name,
2204 -- and also the entity pointer for the prefix
2206 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2207 and then (Is_Entity_Name (Name (N))
2208 or else Nkind (Name (N)) = N_Operator_Symbol)
2210 Set_Etype (Name (N), Expr_Type);
2211 Set_Entity (Name (N), Seen);
2212 Generate_Reference (Seen, Name (N));
2214 elsif Nkind (N) = N_Function_Call
2215 and then Nkind (Name (N)) = N_Selected_Component
2217 Set_Etype (Name (N), Expr_Type);
2218 Set_Entity (Selector_Name (Name (N)), Seen);
2219 Generate_Reference (Seen, Selector_Name (Name (N)));
2221 -- For all other cases, just set the type of the Name
2224 Set_Etype (Name (N), Expr_Type);
2231 -- Move to next interpretation
2233 exit Interp_Loop when No (It.Typ);
2235 Get_Next_Interp (I, It);
2236 end loop Interp_Loop;
2239 -- At this stage Found indicates whether or not an acceptable
2240 -- interpretation exists. If not, then we have an error, except
2241 -- that if the context is Any_Type as a result of some other error,
2242 -- then we suppress the error report.
2245 if Typ /= Any_Type then
2247 -- If type we are looking for is Void, then this is the procedure
2248 -- call case, and the error is simply that what we gave is not a
2249 -- procedure name (we think of procedure calls as expressions with
2250 -- types internally, but the user doesn't think of them this way!)
2252 if Typ = Standard_Void_Type then
2254 -- Special case message if function used as a procedure
2256 if Nkind (N) = N_Procedure_Call_Statement
2257 and then Is_Entity_Name (Name (N))
2258 and then Ekind (Entity (Name (N))) = E_Function
2261 ("cannot use function & in a procedure call",
2262 Name (N), Entity (Name (N)));
2264 -- Otherwise give general message (not clear what cases this
2265 -- covers, but no harm in providing for them!)
2268 Error_Msg_N ("expect procedure name in procedure call", N);
2273 -- Otherwise we do have a subexpression with the wrong type
2275 -- Check for the case of an allocator which uses an access type
2276 -- instead of the designated type. This is a common error and we
2277 -- specialize the message, posting an error on the operand of the
2278 -- allocator, complaining that we expected the designated type of
2281 elsif Nkind (N) = N_Allocator
2282 and then Ekind (Typ) in Access_Kind
2283 and then Ekind (Etype (N)) in Access_Kind
2284 and then Designated_Type (Etype (N)) = Typ
2286 Wrong_Type (Expression (N), Designated_Type (Typ));
2289 -- Check for view mismatch on Null in instances, for which the
2290 -- view-swapping mechanism has no identifier.
2292 elsif (In_Instance or else In_Inlined_Body)
2293 and then (Nkind (N) = N_Null)
2294 and then Is_Private_Type (Typ)
2295 and then Is_Access_Type (Full_View (Typ))
2297 Resolve (N, Full_View (Typ));
2301 -- Check for an aggregate. Sometimes we can get bogus aggregates
2302 -- from misuse of parentheses, and we are about to complain about
2303 -- the aggregate without even looking inside it.
2305 -- Instead, if we have an aggregate of type Any_Composite, then
2306 -- analyze and resolve the component fields, and then only issue
2307 -- another message if we get no errors doing this (otherwise
2308 -- assume that the errors in the aggregate caused the problem).
2310 elsif Nkind (N) = N_Aggregate
2311 and then Etype (N) = Any_Composite
2313 -- Disable expansion in any case. If there is a type mismatch
2314 -- it may be fatal to try to expand the aggregate. The flag
2315 -- would otherwise be set to false when the error is posted.
2317 Expander_Active := False;
2320 procedure Check_Aggr (Aggr : Node_Id);
2321 -- Check one aggregate, and set Found to True if we have a
2322 -- definite error in any of its elements
2324 procedure Check_Elmt (Aelmt : Node_Id);
2325 -- Check one element of aggregate and set Found to True if
2326 -- we definitely have an error in the element.
2332 procedure Check_Aggr (Aggr : Node_Id) is
2336 if Present (Expressions (Aggr)) then
2337 Elmt := First (Expressions (Aggr));
2338 while Present (Elmt) loop
2344 if Present (Component_Associations (Aggr)) then
2345 Elmt := First (Component_Associations (Aggr));
2346 while Present (Elmt) loop
2348 -- If this is a default-initialized component, then
2349 -- there is nothing to check. The box will be
2350 -- replaced by the appropriate call during late
2353 if not Box_Present (Elmt) then
2354 Check_Elmt (Expression (Elmt));
2366 procedure Check_Elmt (Aelmt : Node_Id) is
2368 -- If we have a nested aggregate, go inside it (to
2369 -- attempt a naked analyze-resolve of the aggregate
2370 -- can cause undesirable cascaded errors). Do not
2371 -- resolve expression if it needs a type from context,
2372 -- as for integer * fixed expression.
2374 if Nkind (Aelmt) = N_Aggregate then
2380 if not Is_Overloaded (Aelmt)
2381 and then Etype (Aelmt) /= Any_Fixed
2386 if Etype (Aelmt) = Any_Type then
2397 -- If an error message was issued already, Found got reset
2398 -- to True, so if it is still False, issue the standard
2399 -- Wrong_Type message.
2402 if Is_Overloaded (N)
2403 and then Nkind (N) = N_Function_Call
2406 Subp_Name : Node_Id;
2408 if Is_Entity_Name (Name (N)) then
2409 Subp_Name := Name (N);
2411 elsif Nkind (Name (N)) = N_Selected_Component then
2413 -- Protected operation: retrieve operation name
2415 Subp_Name := Selector_Name (Name (N));
2417 raise Program_Error;
2420 Error_Msg_Node_2 := Typ;
2421 Error_Msg_NE ("no visible interpretation of&" &
2422 " matches expected type&", N, Subp_Name);
2425 if All_Errors_Mode then
2427 Index : Interp_Index;
2431 Error_Msg_N ("\\possible interpretations:", N);
2433 Get_First_Interp (Name (N), Index, It);
2434 while Present (It.Nam) loop
2435 Error_Msg_Sloc := Sloc (It.Nam);
2436 Error_Msg_Node_2 := It.Nam;
2438 ("\\ type& for & declared#", N, It.Typ);
2439 Get_Next_Interp (Index, It);
2444 Error_Msg_N ("\use -gnatf for details", N);
2447 Wrong_Type (N, Typ);
2455 -- Test if we have more than one interpretation for the context
2457 elsif Ambiguous then
2461 -- Here we have an acceptable interpretation for the context
2464 -- Propagate type information and normalize tree for various
2465 -- predefined operations. If the context only imposes a class of
2466 -- types, rather than a specific type, propagate the actual type
2469 if Typ = Any_Integer
2470 or else Typ = Any_Boolean
2471 or else Typ = Any_Modular
2472 or else Typ = Any_Real
2473 or else Typ = Any_Discrete
2475 Ctx_Type := Expr_Type;
2477 -- Any_Fixed is legal in a real context only if a specific
2478 -- fixed point type is imposed. If Norman Cohen can be
2479 -- confused by this, it deserves a separate message.
2482 and then Expr_Type = Any_Fixed
2484 Error_Msg_N ("illegal context for mixed mode operation", N);
2485 Set_Etype (N, Universal_Real);
2486 Ctx_Type := Universal_Real;
2490 -- A user-defined operator is transformed into a function call at
2491 -- this point, so that further processing knows that operators are
2492 -- really operators (i.e. are predefined operators). User-defined
2493 -- operators that are intrinsic are just renamings of the predefined
2494 -- ones, and need not be turned into calls either, but if they rename
2495 -- a different operator, we must transform the node accordingly.
2496 -- Instantiations of Unchecked_Conversion are intrinsic but are
2497 -- treated as functions, even if given an operator designator.
2499 if Nkind (N) in N_Op
2500 and then Present (Entity (N))
2501 and then Ekind (Entity (N)) /= E_Operator
2504 if not Is_Predefined_Op (Entity (N)) then
2505 Rewrite_Operator_As_Call (N, Entity (N));
2507 elsif Present (Alias (Entity (N)))
2509 Nkind (Parent (Parent (Entity (N)))) =
2510 N_Subprogram_Renaming_Declaration
2512 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2514 -- If the node is rewritten, it will be fully resolved in
2515 -- Rewrite_Renamed_Operator.
2517 if Analyzed (N) then
2523 case N_Subexpr'(Nkind (N)) is
2525 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2527 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2529 when N_Short_Circuit
2530 => Resolve_Short_Circuit (N, Ctx_Type);
2532 when N_Attribute_Reference
2533 => Resolve_Attribute (N, Ctx_Type);
2535 when N_Character_Literal
2536 => Resolve_Character_Literal (N, Ctx_Type);
2538 when N_Conditional_Expression
2539 => Resolve_Conditional_Expression (N, Ctx_Type);
2541 when N_Expanded_Name
2542 => Resolve_Entity_Name (N, Ctx_Type);
2544 when N_Extension_Aggregate
2545 => Resolve_Extension_Aggregate (N, Ctx_Type);
2547 when N_Explicit_Dereference
2548 => Resolve_Explicit_Dereference (N, Ctx_Type);
2550 when N_Function_Call
2551 => Resolve_Call (N, Ctx_Type);
2554 => Resolve_Entity_Name (N, Ctx_Type);
2556 when N_Indexed_Component
2557 => Resolve_Indexed_Component (N, Ctx_Type);
2559 when N_Integer_Literal
2560 => Resolve_Integer_Literal (N, Ctx_Type);
2562 when N_Membership_Test
2563 => Resolve_Membership_Op (N, Ctx_Type);
2565 when N_Null => Resolve_Null (N, Ctx_Type);
2567 when N_Op_And | N_Op_Or | N_Op_Xor
2568 => Resolve_Logical_Op (N, Ctx_Type);
2570 when N_Op_Eq | N_Op_Ne
2571 => Resolve_Equality_Op (N, Ctx_Type);
2573 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2574 => Resolve_Comparison_Op (N, Ctx_Type);
2576 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2578 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2579 N_Op_Divide | N_Op_Mod | N_Op_Rem
2581 => Resolve_Arithmetic_Op (N, Ctx_Type);
2583 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2585 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2587 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2588 => Resolve_Unary_Op (N, Ctx_Type);
2590 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2592 when N_Procedure_Call_Statement
2593 => Resolve_Call (N, Ctx_Type);
2595 when N_Operator_Symbol
2596 => Resolve_Operator_Symbol (N, Ctx_Type);
2598 when N_Qualified_Expression
2599 => Resolve_Qualified_Expression (N, Ctx_Type);
2601 when N_Raise_xxx_Error
2602 => Set_Etype (N, Ctx_Type);
2604 when N_Range => Resolve_Range (N, Ctx_Type);
2607 => Resolve_Real_Literal (N, Ctx_Type);
2609 when N_Reference => Resolve_Reference (N, Ctx_Type);
2611 when N_Selected_Component
2612 => Resolve_Selected_Component (N, Ctx_Type);
2614 when N_Slice => Resolve_Slice (N, Ctx_Type);
2616 when N_String_Literal
2617 => Resolve_String_Literal (N, Ctx_Type);
2619 when N_Subprogram_Info
2620 => Resolve_Subprogram_Info (N, Ctx_Type);
2622 when N_Type_Conversion
2623 => Resolve_Type_Conversion (N, Ctx_Type);
2625 when N_Unchecked_Expression =>
2626 Resolve_Unchecked_Expression (N, Ctx_Type);
2628 when N_Unchecked_Type_Conversion =>
2629 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2633 -- If the subexpression was replaced by a non-subexpression, then
2634 -- all we do is to expand it. The only legitimate case we know of
2635 -- is converting procedure call statement to entry call statements,
2636 -- but there may be others, so we are making this test general.
2638 if Nkind (N) not in N_Subexpr then
2639 Debug_A_Exit ("resolving ", N, " (done)");
2644 -- The expression is definitely NOT overloaded at this point, so
2645 -- we reset the Is_Overloaded flag to avoid any confusion when
2646 -- reanalyzing the node.
2648 Set_Is_Overloaded (N, False);
2650 -- Freeze expression type, entity if it is a name, and designated
2651 -- type if it is an allocator (RM 13.14(10,11,13)).
2653 -- Now that the resolution of the type of the node is complete,
2654 -- and we did not detect an error, we can expand this node. We
2655 -- skip the expand call if we are in a default expression, see
2656 -- section "Handling of Default Expressions" in Sem spec.
2658 Debug_A_Exit ("resolving ", N, " (done)");
2660 -- We unconditionally freeze the expression, even if we are in
2661 -- default expression mode (the Freeze_Expression routine tests
2662 -- this flag and only freezes static types if it is set).
2664 Freeze_Expression (N);
2666 -- Now we can do the expansion
2676 -- Version with check(s) suppressed
2678 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2680 if Suppress = All_Checks then
2682 Svg : constant Suppress_Array := Scope_Suppress;
2684 Scope_Suppress := (others => True);
2686 Scope_Suppress := Svg;
2691 Svg : constant Boolean := Scope_Suppress (Suppress);
2693 Scope_Suppress (Suppress) := True;
2695 Scope_Suppress (Suppress) := Svg;
2704 -- Version with implicit type
2706 procedure Resolve (N : Node_Id) is
2708 Resolve (N, Etype (N));
2711 ---------------------
2712 -- Resolve_Actuals --
2713 ---------------------
2715 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2716 Loc : constant Source_Ptr := Sloc (N);
2721 Prev : Node_Id := Empty;
2724 procedure Check_Argument_Order;
2725 -- Performs a check for the case where the actuals are all simple
2726 -- identifiers that correspond to the formal names, but in the wrong
2727 -- order, which is considered suspicious and cause for a warning.
2729 procedure Check_Prefixed_Call;
2730 -- If the original node is an overloaded call in prefix notation,
2731 -- insert an 'Access or a dereference as needed over the first actual.
2732 -- Try_Object_Operation has already verified that there is a valid
2733 -- interpretation, but the form of the actual can only be determined
2734 -- once the primitive operation is identified.
2736 procedure Insert_Default;
2737 -- If the actual is missing in a call, insert in the actuals list
2738 -- an instance of the default expression. The insertion is always
2739 -- a named association.
2741 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2742 -- Check whether T1 and T2, or their full views, are derived from a
2743 -- common type. Used to enforce the restrictions on array conversions
2746 function Static_Concatenation (N : Node_Id) return Boolean;
2747 -- Predicate to determine whether an actual that is a concatenation
2748 -- will be evaluated statically and does not need a transient scope.
2749 -- This must be determined before the actual is resolved and expanded
2750 -- because if needed the transient scope must be introduced earlier.
2752 --------------------------
2753 -- Check_Argument_Order --
2754 --------------------------
2756 procedure Check_Argument_Order is
2758 -- Nothing to do if no parameters, or original node is neither a
2759 -- function call nor a procedure call statement (happens in the
2760 -- operator-transformed-to-function call case), or the call does
2761 -- not come from source, or this warning is off.
2763 if not Warn_On_Parameter_Order
2765 No (Parameter_Associations (N))
2767 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2770 not Comes_From_Source (N)
2776 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2779 -- Nothing to do if only one parameter
2785 -- Here if at least two arguments
2788 Actuals : array (1 .. Nargs) of Node_Id;
2792 Wrong_Order : Boolean := False;
2793 -- Set True if an out of order case is found
2796 -- Collect identifier names of actuals, fail if any actual is
2797 -- not a simple identifier, and record max length of name.
2799 Actual := First (Parameter_Associations (N));
2800 for J in Actuals'Range loop
2801 if Nkind (Actual) /= N_Identifier then
2804 Actuals (J) := Actual;
2809 -- If we got this far, all actuals are identifiers and the list
2810 -- of their names is stored in the Actuals array.
2812 Formal := First_Formal (Nam);
2813 for J in Actuals'Range loop
2815 -- If we ran out of formals, that's odd, probably an error
2816 -- which will be detected elsewhere, but abandon the search.
2822 -- If name matches and is in order OK
2824 if Chars (Formal) = Chars (Actuals (J)) then
2828 -- If no match, see if it is elsewhere in list and if so
2829 -- flag potential wrong order if type is compatible.
2831 for K in Actuals'Range loop
2832 if Chars (Formal) = Chars (Actuals (K))
2834 Has_Compatible_Type (Actuals (K), Etype (Formal))
2836 Wrong_Order := True;
2846 <<Continue>> Next_Formal (Formal);
2849 -- If Formals left over, also probably an error, skip warning
2851 if Present (Formal) then
2855 -- Here we give the warning if something was out of order
2859 ("actuals for this call may be in wrong order?", N);
2863 end Check_Argument_Order;
2865 -------------------------
2866 -- Check_Prefixed_Call --
2867 -------------------------
2869 procedure Check_Prefixed_Call is
2870 Act : constant Node_Id := First_Actual (N);
2871 A_Type : constant Entity_Id := Etype (Act);
2872 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2873 Orig : constant Node_Id := Original_Node (N);
2877 -- Check whether the call is a prefixed call, with or without
2878 -- additional actuals.
2880 if Nkind (Orig) = N_Selected_Component
2882 (Nkind (Orig) = N_Indexed_Component
2883 and then Nkind (Prefix (Orig)) = N_Selected_Component
2884 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2885 and then Is_Entity_Name (Act)
2886 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2888 if Is_Access_Type (A_Type)
2889 and then not Is_Access_Type (F_Type)
2891 -- Introduce dereference on object in prefix
2894 Make_Explicit_Dereference (Sloc (Act),
2895 Prefix => Relocate_Node (Act));
2896 Rewrite (Act, New_A);
2899 elsif Is_Access_Type (F_Type)
2900 and then not Is_Access_Type (A_Type)
2902 -- Introduce an implicit 'Access in prefix
2904 if not Is_Aliased_View (Act) then
2906 ("object in prefixed call to& must be aliased"
2907 & " (RM-2005 4.3.1 (13))",
2912 Make_Attribute_Reference (Loc,
2913 Attribute_Name => Name_Access,
2914 Prefix => Relocate_Node (Act)));
2919 end Check_Prefixed_Call;
2921 --------------------
2922 -- Insert_Default --
2923 --------------------
2925 procedure Insert_Default is
2930 -- Missing argument in call, nothing to insert
2932 if No (Default_Value (F)) then
2936 -- Note that we do a full New_Copy_Tree, so that any associated
2937 -- Itypes are properly copied. This may not be needed any more,
2938 -- but it does no harm as a safety measure! Defaults of a generic
2939 -- formal may be out of bounds of the corresponding actual (see
2940 -- cc1311b) and an additional check may be required.
2945 New_Scope => Current_Scope,
2948 if Is_Concurrent_Type (Scope (Nam))
2949 and then Has_Discriminants (Scope (Nam))
2951 Replace_Actual_Discriminants (N, Actval);
2954 if Is_Overloadable (Nam)
2955 and then Present (Alias (Nam))
2957 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2958 and then not Is_Tagged_Type (Etype (F))
2960 -- If default is a real literal, do not introduce a
2961 -- conversion whose effect may depend on the run-time
2962 -- size of universal real.
2964 if Nkind (Actval) = N_Real_Literal then
2965 Set_Etype (Actval, Base_Type (Etype (F)));
2967 Actval := Unchecked_Convert_To (Etype (F), Actval);
2971 if Is_Scalar_Type (Etype (F)) then
2972 Enable_Range_Check (Actval);
2975 Set_Parent (Actval, N);
2977 -- Resolve aggregates with their base type, to avoid scope
2978 -- anomalies: the subtype was first built in the subprogram
2979 -- declaration, and the current call may be nested.
2981 if Nkind (Actval) = N_Aggregate then
2982 Analyze_And_Resolve (Actval, Etype (F));
2984 Analyze_And_Resolve (Actval, Etype (Actval));
2988 Set_Parent (Actval, N);
2990 -- See note above concerning aggregates
2992 if Nkind (Actval) = N_Aggregate
2993 and then Has_Discriminants (Etype (Actval))
2995 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2997 -- Resolve entities with their own type, which may differ
2998 -- from the type of a reference in a generic context (the
2999 -- view swapping mechanism did not anticipate the re-analysis
3000 -- of default values in calls).
3002 elsif Is_Entity_Name (Actval) then
3003 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3006 Analyze_And_Resolve (Actval, Etype (Actval));
3010 -- If default is a tag indeterminate function call, propagate
3011 -- tag to obtain proper dispatching.
3013 if Is_Controlling_Formal (F)
3014 and then Nkind (Default_Value (F)) = N_Function_Call
3016 Set_Is_Controlling_Actual (Actval);
3021 -- If the default expression raises constraint error, then just
3022 -- silently replace it with an N_Raise_Constraint_Error node,
3023 -- since we already gave the warning on the subprogram spec.
3025 if Raises_Constraint_Error (Actval) then
3027 Make_Raise_Constraint_Error (Loc,
3028 Reason => CE_Range_Check_Failed));
3029 Set_Raises_Constraint_Error (Actval);
3030 Set_Etype (Actval, Etype (F));
3034 Make_Parameter_Association (Loc,
3035 Explicit_Actual_Parameter => Actval,
3036 Selector_Name => Make_Identifier (Loc, Chars (F)));
3038 -- Case of insertion is first named actual
3040 if No (Prev) or else
3041 Nkind (Parent (Prev)) /= N_Parameter_Association
3043 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3044 Set_First_Named_Actual (N, Actval);
3047 if No (Parameter_Associations (N)) then
3048 Set_Parameter_Associations (N, New_List (Assoc));
3050 Append (Assoc, Parameter_Associations (N));
3054 Insert_After (Prev, Assoc);
3057 -- Case of insertion is not first named actual
3060 Set_Next_Named_Actual
3061 (Assoc, Next_Named_Actual (Parent (Prev)));
3062 Set_Next_Named_Actual (Parent (Prev), Actval);
3063 Append (Assoc, Parameter_Associations (N));
3066 Mark_Rewrite_Insertion (Assoc);
3067 Mark_Rewrite_Insertion (Actval);
3076 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3077 FT1 : Entity_Id := T1;
3078 FT2 : Entity_Id := T2;
3081 if Is_Private_Type (T1)
3082 and then Present (Full_View (T1))
3084 FT1 := Full_View (T1);
3087 if Is_Private_Type (T2)
3088 and then Present (Full_View (T2))
3090 FT2 := Full_View (T2);
3093 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3096 --------------------------
3097 -- Static_Concatenation --
3098 --------------------------
3100 function Static_Concatenation (N : Node_Id) return Boolean is
3103 when N_String_Literal =>
3108 -- Concatenation is static when both operands are static
3109 -- and the concatenation operator is a predefined one.
3111 return Scope (Entity (N)) = Standard_Standard
3113 Static_Concatenation (Left_Opnd (N))
3115 Static_Concatenation (Right_Opnd (N));
3118 if Is_Entity_Name (N) then
3120 Ent : constant Entity_Id := Entity (N);
3122 return Ekind (Ent) = E_Constant
3123 and then Present (Constant_Value (Ent))
3125 Is_Static_Expression (Constant_Value (Ent));
3132 end Static_Concatenation;
3134 -- Start of processing for Resolve_Actuals
3137 Check_Argument_Order;
3139 if Present (First_Actual (N)) then
3140 Check_Prefixed_Call;
3143 A := First_Actual (N);
3144 F := First_Formal (Nam);
3145 while Present (F) loop
3146 if No (A) and then Needs_No_Actuals (Nam) then
3149 -- If we have an error in any actual or formal, indicated by a type
3150 -- of Any_Type, then abandon resolution attempt, and set result type
3153 elsif (Present (A) and then Etype (A) = Any_Type)
3154 or else Etype (F) = Any_Type
3156 Set_Etype (N, Any_Type);
3160 -- Case where actual is present
3162 -- If the actual is an entity, generate a reference to it now. We
3163 -- do this before the actual is resolved, because a formal of some
3164 -- protected subprogram, or a task discriminant, will be rewritten
3165 -- during expansion, and the reference to the source entity may
3169 and then Is_Entity_Name (A)
3170 and then Comes_From_Source (N)
3172 Orig_A := Entity (A);
3174 if Present (Orig_A) then
3175 if Is_Formal (Orig_A)
3176 and then Ekind (F) /= E_In_Parameter
3178 Generate_Reference (Orig_A, A, 'm');
3179 elsif not Is_Overloaded (A) then
3180 Generate_Reference (Orig_A, A);
3186 and then (Nkind (Parent (A)) /= N_Parameter_Association
3188 Chars (Selector_Name (Parent (A))) = Chars (F))
3190 -- If style checking mode on, check match of formal name
3193 if Nkind (Parent (A)) = N_Parameter_Association then
3194 Check_Identifier (Selector_Name (Parent (A)), F);
3198 -- If the formal is Out or In_Out, do not resolve and expand the
3199 -- conversion, because it is subsequently expanded into explicit
3200 -- temporaries and assignments. However, the object of the
3201 -- conversion can be resolved. An exception is the case of tagged
3202 -- type conversion with a class-wide actual. In that case we want
3203 -- the tag check to occur and no temporary will be needed (no
3204 -- representation change can occur) and the parameter is passed by
3205 -- reference, so we go ahead and resolve the type conversion.
3206 -- Another exception is the case of reference to component or
3207 -- subcomponent of a bit-packed array, in which case we want to
3208 -- defer expansion to the point the in and out assignments are
3211 if Ekind (F) /= E_In_Parameter
3212 and then Nkind (A) = N_Type_Conversion
3213 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3215 if Ekind (F) = E_In_Out_Parameter
3216 and then Is_Array_Type (Etype (F))
3218 if Has_Aliased_Components (Etype (Expression (A)))
3219 /= Has_Aliased_Components (Etype (F))
3222 -- In a view conversion, the conversion must be legal in
3223 -- both directions, and thus both component types must be
3224 -- aliased, or neither (4.6 (8)).
3226 -- The additional rule 4.6 (24.9.2) seems unduly
3227 -- restrictive: the privacy requirement should not apply
3228 -- to generic types, and should be checked in an
3229 -- instance. ARG query is in order ???
3232 ("both component types in a view conversion must be"
3233 & " aliased, or neither", A);
3236 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3238 if Is_By_Reference_Type (Etype (F))
3239 or else Is_By_Reference_Type (Etype (Expression (A)))
3242 ("view conversion between unrelated by reference " &
3243 "array types not allowed (\'A'I-00246)", A);
3246 Comp_Type : constant Entity_Id :=
3248 (Etype (Expression (A)));
3250 if Comes_From_Source (A)
3251 and then Ada_Version >= Ada_05
3253 ((Is_Private_Type (Comp_Type)
3254 and then not Is_Generic_Type (Comp_Type))
3255 or else Is_Tagged_Type (Comp_Type)
3256 or else Is_Volatile (Comp_Type))
3259 ("component type of a view conversion cannot"
3260 & " be private, tagged, or volatile"
3269 if (Conversion_OK (A)
3270 or else Valid_Conversion (A, Etype (A), Expression (A)))
3271 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3273 Resolve (Expression (A));
3276 -- If the actual is a function call that returns a limited
3277 -- unconstrained object that needs finalization, create a
3278 -- transient scope for it, so that it can receive the proper
3279 -- finalization list.
3281 elsif Nkind (A) = N_Function_Call
3282 and then Is_Limited_Record (Etype (F))
3283 and then not Is_Constrained (Etype (F))
3284 and then Expander_Active
3286 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3288 Establish_Transient_Scope (A, False);
3290 -- A small optimization: if one of the actuals is a concatenation
3291 -- create a block around a procedure call to recover stack space.
3292 -- This alleviates stack usage when several procedure calls in
3293 -- the same statement list use concatenation. We do not perform
3294 -- this wrapping for code statements, where the argument is a
3295 -- static string, and we want to preserve warnings involving
3296 -- sequences of such statements.
3298 elsif Nkind (A) = N_Op_Concat
3299 and then Nkind (N) = N_Procedure_Call_Statement
3300 and then Expander_Active
3302 not (Is_Intrinsic_Subprogram (Nam)
3303 and then Chars (Nam) = Name_Asm)
3304 and then not Static_Concatenation (A)
3306 Establish_Transient_Scope (A, False);
3307 Resolve (A, Etype (F));
3310 if Nkind (A) = N_Type_Conversion
3311 and then Is_Array_Type (Etype (F))
3312 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3314 (Is_Limited_Type (Etype (F))
3315 or else Is_Limited_Type (Etype (Expression (A))))
3318 ("conversion between unrelated limited array types " &
3319 "not allowed (\A\I-00246)", A);
3321 if Is_Limited_Type (Etype (F)) then
3322 Explain_Limited_Type (Etype (F), A);
3325 if Is_Limited_Type (Etype (Expression (A))) then
3326 Explain_Limited_Type (Etype (Expression (A)), A);
3330 -- (Ada 2005: AI-251): If the actual is an allocator whose
3331 -- directly designated type is a class-wide interface, we build
3332 -- an anonymous access type to use it as the type of the
3333 -- allocator. Later, when the subprogram call is expanded, if
3334 -- the interface has a secondary dispatch table the expander
3335 -- will add a type conversion to force the correct displacement
3338 if Nkind (A) = N_Allocator then
3340 DDT : constant Entity_Id :=
3341 Directly_Designated_Type (Base_Type (Etype (F)));
3343 New_Itype : Entity_Id;
3346 if Is_Class_Wide_Type (DDT)
3347 and then Is_Interface (DDT)
3349 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3350 Set_Etype (New_Itype, Etype (A));
3351 Set_Directly_Designated_Type (New_Itype,
3352 Directly_Designated_Type (Etype (A)));
3353 Set_Etype (A, New_Itype);
3356 -- Ada 2005, AI-162:If the actual is an allocator, the
3357 -- innermost enclosing statement is the master of the
3358 -- created object. This needs to be done with expansion
3359 -- enabled only, otherwise the transient scope will not
3360 -- be removed in the expansion of the wrapped construct.
3362 if (Is_Controlled (DDT) or else Has_Task (DDT))
3363 and then Expander_Active
3365 Establish_Transient_Scope (A, False);
3370 -- (Ada 2005): The call may be to a primitive operation of
3371 -- a tagged synchronized type, declared outside of the type.
3372 -- In this case the controlling actual must be converted to
3373 -- its corresponding record type, which is the formal type.
3374 -- The actual may be a subtype, either because of a constraint
3375 -- or because it is a generic actual, so use base type to
3376 -- locate concurrent type.
3378 A_Typ := Base_Type (Etype (A));
3379 F_Typ := Base_Type (Etype (F));
3382 Full_A_Typ : Entity_Id;
3385 if Present (Full_View (A_Typ)) then
3386 Full_A_Typ := Base_Type (Full_View (A_Typ));
3388 Full_A_Typ := A_Typ;
3391 -- Tagged synchronized type (case 1): the actual is a
3394 if Is_Concurrent_Type (A_Typ)
3395 and then Corresponding_Record_Type (A_Typ) = F_Typ
3398 Unchecked_Convert_To
3399 (Corresponding_Record_Type (A_Typ), A));
3400 Resolve (A, Etype (F));
3402 -- Tagged synchronized type (case 2): the formal is a
3405 elsif Ekind (Full_A_Typ) = E_Record_Type
3407 (Corresponding_Concurrent_Type (Full_A_Typ))
3408 and then Is_Concurrent_Type (F_Typ)
3409 and then Present (Corresponding_Record_Type (F_Typ))
3410 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3412 Resolve (A, Corresponding_Record_Type (F_Typ));
3417 Resolve (A, Etype (F));
3425 -- For mode IN, if actual is an entity, and the type of the formal
3426 -- has warnings suppressed, then we reset Never_Set_In_Source for
3427 -- the calling entity. The reason for this is to catch cases like
3428 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3429 -- uses trickery to modify an IN parameter.
3431 if Ekind (F) = E_In_Parameter
3432 and then Is_Entity_Name (A)
3433 and then Present (Entity (A))
3434 and then Ekind (Entity (A)) = E_Variable
3435 and then Has_Warnings_Off (F_Typ)
3437 Set_Never_Set_In_Source (Entity (A), False);
3440 -- Perform error checks for IN and IN OUT parameters
3442 if Ekind (F) /= E_Out_Parameter then
3444 -- Check unset reference. For scalar parameters, it is clearly
3445 -- wrong to pass an uninitialized value as either an IN or
3446 -- IN-OUT parameter. For composites, it is also clearly an
3447 -- error to pass a completely uninitialized value as an IN
3448 -- parameter, but the case of IN OUT is trickier. We prefer
3449 -- not to give a warning here. For example, suppose there is
3450 -- a routine that sets some component of a record to False.
3451 -- It is perfectly reasonable to make this IN-OUT and allow
3452 -- either initialized or uninitialized records to be passed
3455 -- For partially initialized composite values, we also avoid
3456 -- warnings, since it is quite likely that we are passing a
3457 -- partially initialized value and only the initialized fields
3458 -- will in fact be read in the subprogram.
3460 if Is_Scalar_Type (A_Typ)
3461 or else (Ekind (F) = E_In_Parameter
3462 and then not Is_Partially_Initialized_Type (A_Typ))
3464 Check_Unset_Reference (A);
3467 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3468 -- actual to a nested call, since this is case of reading an
3469 -- out parameter, which is not allowed.
3471 if Ada_Version = Ada_83
3472 and then Is_Entity_Name (A)
3473 and then Ekind (Entity (A)) = E_Out_Parameter
3475 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3479 -- Case of OUT or IN OUT parameter
3481 if Ekind (F) /= E_In_Parameter then
3483 -- For an Out parameter, check for useless assignment. Note
3484 -- that we can't set Last_Assignment this early, because we may
3485 -- kill current values in Resolve_Call, and that call would
3486 -- clobber the Last_Assignment field.
3488 -- Note: call Warn_On_Useless_Assignment before doing the check
3489 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3490 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3491 -- reflects the last assignment, not this one!
3493 if Ekind (F) = E_Out_Parameter then
3494 if Warn_On_Modified_As_Out_Parameter (F)
3495 and then Is_Entity_Name (A)
3496 and then Present (Entity (A))
3497 and then Comes_From_Source (N)
3499 Warn_On_Useless_Assignment (Entity (A), A);
3503 -- Validate the form of the actual. Note that the call to
3504 -- Is_OK_Variable_For_Out_Formal generates the required
3505 -- reference in this case.
3507 if not Is_OK_Variable_For_Out_Formal (A) then
3508 Error_Msg_NE ("actual for& must be a variable", A, F);
3511 -- What's the following about???
3513 if Is_Entity_Name (A) then
3514 Kill_Checks (Entity (A));
3520 if Etype (A) = Any_Type then
3521 Set_Etype (N, Any_Type);
3525 -- Apply appropriate range checks for in, out, and in-out
3526 -- parameters. Out and in-out parameters also need a separate
3527 -- check, if there is a type conversion, to make sure the return
3528 -- value meets the constraints of the variable before the
3531 -- Gigi looks at the check flag and uses the appropriate types.
3532 -- For now since one flag is used there is an optimization which
3533 -- might not be done in the In Out case since Gigi does not do
3534 -- any analysis. More thought required about this ???
3536 if Ekind (F) = E_In_Parameter
3537 or else Ekind (F) = E_In_Out_Parameter
3539 if Is_Scalar_Type (Etype (A)) then
3540 Apply_Scalar_Range_Check (A, F_Typ);
3542 elsif Is_Array_Type (Etype (A)) then
3543 Apply_Length_Check (A, F_Typ);
3545 elsif Is_Record_Type (F_Typ)
3546 and then Has_Discriminants (F_Typ)
3547 and then Is_Constrained (F_Typ)
3548 and then (not Is_Derived_Type (F_Typ)
3549 or else Comes_From_Source (Nam))
3551 Apply_Discriminant_Check (A, F_Typ);
3553 elsif Is_Access_Type (F_Typ)
3554 and then Is_Array_Type (Designated_Type (F_Typ))
3555 and then Is_Constrained (Designated_Type (F_Typ))
3557 Apply_Length_Check (A, F_Typ);
3559 elsif Is_Access_Type (F_Typ)
3560 and then Has_Discriminants (Designated_Type (F_Typ))
3561 and then Is_Constrained (Designated_Type (F_Typ))
3563 Apply_Discriminant_Check (A, F_Typ);
3566 Apply_Range_Check (A, F_Typ);
3569 -- Ada 2005 (AI-231)
3571 if Ada_Version >= Ada_05
3572 and then Is_Access_Type (F_Typ)
3573 and then Can_Never_Be_Null (F_Typ)
3574 and then Known_Null (A)
3576 Apply_Compile_Time_Constraint_Error
3578 Msg => "(Ada 2005) null not allowed in "
3579 & "null-excluding formal?",
3580 Reason => CE_Null_Not_Allowed);
3584 if Ekind (F) = E_Out_Parameter
3585 or else Ekind (F) = E_In_Out_Parameter
3587 if Nkind (A) = N_Type_Conversion then
3588 if Is_Scalar_Type (A_Typ) then
3589 Apply_Scalar_Range_Check
3590 (Expression (A), Etype (Expression (A)), A_Typ);
3593 (Expression (A), Etype (Expression (A)), A_Typ);
3597 if Is_Scalar_Type (F_Typ) then
3598 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3600 elsif Is_Array_Type (F_Typ)
3601 and then Ekind (F) = E_Out_Parameter
3603 Apply_Length_Check (A, F_Typ);
3606 Apply_Range_Check (A, A_Typ, F_Typ);
3611 -- An actual associated with an access parameter is implicitly
3612 -- converted to the anonymous access type of the formal and must
3613 -- satisfy the legality checks for access conversions.
3615 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3616 if not Valid_Conversion (A, F_Typ, A) then
3618 ("invalid implicit conversion for access parameter", A);
3622 -- Check bad case of atomic/volatile argument (RM C.6(12))
3624 if Is_By_Reference_Type (Etype (F))
3625 and then Comes_From_Source (N)
3627 if Is_Atomic_Object (A)
3628 and then not Is_Atomic (Etype (F))
3631 ("cannot pass atomic argument to non-atomic formal",
3634 elsif Is_Volatile_Object (A)
3635 and then not Is_Volatile (Etype (F))
3638 ("cannot pass volatile argument to non-volatile formal",
3643 -- Check that subprograms don't have improper controlling
3644 -- arguments (RM 3.9.2 (9)).
3646 -- A primitive operation may have an access parameter of an
3647 -- incomplete tagged type, but a dispatching call is illegal
3648 -- if the type is still incomplete.
3650 if Is_Controlling_Formal (F) then
3651 Set_Is_Controlling_Actual (A);
3653 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3655 Desig : constant Entity_Id := Designated_Type (Etype (F));
3657 if Ekind (Desig) = E_Incomplete_Type
3658 and then No (Full_View (Desig))
3659 and then No (Non_Limited_View (Desig))
3662 ("premature use of incomplete type& " &
3663 "in dispatching call", A, Desig);
3668 elsif Nkind (A) = N_Explicit_Dereference then
3669 Validate_Remote_Access_To_Class_Wide_Type (A);
3672 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3673 and then not Is_Class_Wide_Type (F_Typ)
3674 and then not Is_Controlling_Formal (F)
3676 Error_Msg_N ("class-wide argument not allowed here!", A);
3678 if Is_Subprogram (Nam)
3679 and then Comes_From_Source (Nam)
3681 Error_Msg_Node_2 := F_Typ;
3683 ("& is not a dispatching operation of &!", A, Nam);
3686 elsif Is_Access_Type (A_Typ)
3687 and then Is_Access_Type (F_Typ)
3688 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3689 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3690 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3691 or else (Nkind (A) = N_Attribute_Reference
3693 Is_Class_Wide_Type (Etype (Prefix (A)))))
3694 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3695 and then not Is_Controlling_Formal (F)
3697 -- Disable these checks for call to imported C++ subprograms
3700 (Is_Entity_Name (Name (N))
3701 and then Is_Imported (Entity (Name (N)))
3702 and then Convention (Entity (Name (N))) = Convention_CPP)
3705 ("access to class-wide argument not allowed here!", A);
3707 if Is_Subprogram (Nam)
3708 and then Comes_From_Source (Nam)
3710 Error_Msg_Node_2 := Designated_Type (F_Typ);
3712 ("& is not a dispatching operation of &!", A, Nam);
3718 -- If it is a named association, treat the selector_name as
3719 -- a proper identifier, and mark the corresponding entity.
3721 if Nkind (Parent (A)) = N_Parameter_Association then
3722 Set_Entity (Selector_Name (Parent (A)), F);
3723 Generate_Reference (F, Selector_Name (Parent (A)));
3724 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3725 Generate_Reference (F_Typ, N, ' ');
3730 if Ekind (F) /= E_Out_Parameter then
3731 Check_Unset_Reference (A);
3736 -- Case where actual is not present
3744 end Resolve_Actuals;
3746 -----------------------
3747 -- Resolve_Allocator --
3748 -----------------------
3750 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3751 E : constant Node_Id := Expression (N);
3753 Discrim : Entity_Id;
3756 Assoc : Node_Id := Empty;
3759 procedure Check_Allocator_Discrim_Accessibility
3760 (Disc_Exp : Node_Id;
3761 Alloc_Typ : Entity_Id);
3762 -- Check that accessibility level associated with an access discriminant
3763 -- initialized in an allocator by the expression Disc_Exp is not deeper
3764 -- than the level of the allocator type Alloc_Typ. An error message is
3765 -- issued if this condition is violated. Specialized checks are done for
3766 -- the cases of a constraint expression which is an access attribute or
3767 -- an access discriminant.
3769 function In_Dispatching_Context return Boolean;
3770 -- If the allocator is an actual in a call, it is allowed to be class-
3771 -- wide when the context is not because it is a controlling actual.
3773 procedure Propagate_Coextensions (Root : Node_Id);
3774 -- Propagate all nested coextensions which are located one nesting
3775 -- level down the tree to the node Root. Example:
3778 -- Level_1_Coextension
3779 -- Level_2_Coextension
3781 -- The algorithm is paired with delay actions done by the Expander. In
3782 -- the above example, assume all coextensions are controlled types.
3783 -- The cycle of analysis, resolution and expansion will yield:
3785 -- 1) Analyze Top_Record
3786 -- 2) Analyze Level_1_Coextension
3787 -- 3) Analyze Level_2_Coextension
3788 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3790 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3791 -- generated to capture the allocated object. Temp_1 is attached
3792 -- to the coextension chain of Level_2_Coextension.
3793 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3794 -- coextension. A forward tree traversal is performed which finds
3795 -- Level_2_Coextension's list and copies its contents into its
3797 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3798 -- generated to capture the allocated object. Temp_2 is attached
3799 -- to the coextension chain of Level_1_Coextension. Currently, the
3800 -- contents of the list are [Temp_2, Temp_1].
3801 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3802 -- finds Level_1_Coextension's list and copies its contents into
3804 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3805 -- Temp_2 and attach them to Top_Record's finalization list.
3807 -------------------------------------------
3808 -- Check_Allocator_Discrim_Accessibility --
3809 -------------------------------------------
3811 procedure Check_Allocator_Discrim_Accessibility
3812 (Disc_Exp : Node_Id;
3813 Alloc_Typ : Entity_Id)
3816 if Type_Access_Level (Etype (Disc_Exp)) >
3817 Type_Access_Level (Alloc_Typ)
3820 ("operand type has deeper level than allocator type", Disc_Exp);
3822 -- When the expression is an Access attribute the level of the prefix
3823 -- object must not be deeper than that of the allocator's type.
3825 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3826 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3828 and then Object_Access_Level (Prefix (Disc_Exp))
3829 > Type_Access_Level (Alloc_Typ)
3832 ("prefix of attribute has deeper level than allocator type",
3835 -- When the expression is an access discriminant the check is against
3836 -- the level of the prefix object.
3838 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3839 and then Nkind (Disc_Exp) = N_Selected_Component
3840 and then Object_Access_Level (Prefix (Disc_Exp))
3841 > Type_Access_Level (Alloc_Typ)
3844 ("access discriminant has deeper level than allocator type",
3847 -- All other cases are legal
3852 end Check_Allocator_Discrim_Accessibility;
3854 ----------------------------
3855 -- In_Dispatching_Context --
3856 ----------------------------
3858 function In_Dispatching_Context return Boolean is
3859 Par : constant Node_Id := Parent (N);
3861 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3862 and then Is_Entity_Name (Name (Par))
3863 and then Is_Dispatching_Operation (Entity (Name (Par)));
3864 end In_Dispatching_Context;
3866 ----------------------------
3867 -- Propagate_Coextensions --
3868 ----------------------------
3870 procedure Propagate_Coextensions (Root : Node_Id) is
3872 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3873 -- Copy the contents of list From into list To, preserving the
3874 -- order of elements.
3876 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3877 -- Recognize an allocator or a rewritten allocator node and add it
3878 -- along with its nested coextensions to the list of Root.
3884 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3885 From_Elmt : Elmt_Id;
3887 From_Elmt := First_Elmt (From);
3888 while Present (From_Elmt) loop
3889 Append_Elmt (Node (From_Elmt), To);
3890 Next_Elmt (From_Elmt);
3894 -----------------------
3895 -- Process_Allocator --
3896 -----------------------
3898 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3899 Orig_Nod : Node_Id := Nod;
3902 -- This is a possible rewritten subtype indication allocator. Any
3903 -- nested coextensions will appear as discriminant constraints.
3905 if Nkind (Nod) = N_Identifier
3906 and then Present (Original_Node (Nod))
3907 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3911 Discr_Elmt : Elmt_Id;
3914 if Is_Record_Type (Entity (Nod)) then
3916 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3917 while Present (Discr_Elmt) loop
3918 Discr := Node (Discr_Elmt);
3920 if Nkind (Discr) = N_Identifier
3921 and then Present (Original_Node (Discr))
3922 and then Nkind (Original_Node (Discr)) = N_Allocator
3923 and then Present (Coextensions (
3924 Original_Node (Discr)))
3926 if No (Coextensions (Root)) then
3927 Set_Coextensions (Root, New_Elmt_List);
3931 (From => Coextensions (Original_Node (Discr)),
3932 To => Coextensions (Root));
3935 Next_Elmt (Discr_Elmt);
3938 -- There is no need to continue the traversal of this
3939 -- subtree since all the information has already been
3946 -- Case of either a stand alone allocator or a rewritten allocator
3947 -- with an aggregate.
3950 if Present (Original_Node (Nod)) then
3951 Orig_Nod := Original_Node (Nod);
3954 if Nkind (Orig_Nod) = N_Allocator then
3956 -- Propagate the list of nested coextensions to the Root
3957 -- allocator. This is done through list copy since a single
3958 -- allocator may have multiple coextensions. Do not touch
3959 -- coextensions roots.
3961 if not Is_Coextension_Root (Orig_Nod)
3962 and then Present (Coextensions (Orig_Nod))
3964 if No (Coextensions (Root)) then
3965 Set_Coextensions (Root, New_Elmt_List);
3969 (From => Coextensions (Orig_Nod),
3970 To => Coextensions (Root));
3973 -- There is no need to continue the traversal of this
3974 -- subtree since all the information has already been
3981 -- Keep on traversing, looking for the next allocator
3984 end Process_Allocator;
3986 procedure Process_Allocators is
3987 new Traverse_Proc (Process_Allocator);
3989 -- Start of processing for Propagate_Coextensions
3992 Process_Allocators (Expression (Root));
3993 end Propagate_Coextensions;
3995 -- Start of processing for Resolve_Allocator
3998 -- Replace general access with specific type
4000 if Ekind (Etype (N)) = E_Allocator_Type then
4001 Set_Etype (N, Base_Type (Typ));
4004 if Is_Abstract_Type (Typ) then
4005 Error_Msg_N ("type of allocator cannot be abstract", N);
4008 -- For qualified expression, resolve the expression using the
4009 -- given subtype (nothing to do for type mark, subtype indication)
4011 if Nkind (E) = N_Qualified_Expression then
4012 if Is_Class_Wide_Type (Etype (E))
4013 and then not Is_Class_Wide_Type (Designated_Type (Typ))
4014 and then not In_Dispatching_Context
4017 ("class-wide allocator not allowed for this access type", N);
4020 Resolve (Expression (E), Etype (E));
4021 Check_Unset_Reference (Expression (E));
4023 -- A qualified expression requires an exact match of the type,
4024 -- class-wide matching is not allowed.
4026 if (Is_Class_Wide_Type (Etype (Expression (E)))
4027 or else Is_Class_Wide_Type (Etype (E)))
4028 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4030 Wrong_Type (Expression (E), Etype (E));
4033 -- A special accessibility check is needed for allocators that
4034 -- constrain access discriminants. The level of the type of the
4035 -- expression used to constrain an access discriminant cannot be
4036 -- deeper than the type of the allocator (in contrast to access
4037 -- parameters, where the level of the actual can be arbitrary).
4039 -- We can't use Valid_Conversion to perform this check because
4040 -- in general the type of the allocator is unrelated to the type
4041 -- of the access discriminant.
4043 if Ekind (Typ) /= E_Anonymous_Access_Type
4044 or else Is_Local_Anonymous_Access (Typ)
4046 Subtyp := Entity (Subtype_Mark (E));
4048 Aggr := Original_Node (Expression (E));
4050 if Has_Discriminants (Subtyp)
4051 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4053 Discrim := First_Discriminant (Base_Type (Subtyp));
4055 -- Get the first component expression of the aggregate
4057 if Present (Expressions (Aggr)) then
4058 Disc_Exp := First (Expressions (Aggr));
4060 elsif Present (Component_Associations (Aggr)) then
4061 Assoc := First (Component_Associations (Aggr));
4063 if Present (Assoc) then
4064 Disc_Exp := Expression (Assoc);
4073 while Present (Discrim) and then Present (Disc_Exp) loop
4074 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4075 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4078 Next_Discriminant (Discrim);
4080 if Present (Discrim) then
4081 if Present (Assoc) then
4083 Disc_Exp := Expression (Assoc);
4085 elsif Present (Next (Disc_Exp)) then
4089 Assoc := First (Component_Associations (Aggr));
4091 if Present (Assoc) then
4092 Disc_Exp := Expression (Assoc);
4102 -- For a subtype mark or subtype indication, freeze the subtype
4105 Freeze_Expression (E);
4107 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4109 ("initialization required for access-to-constant allocator", N);
4112 -- A special accessibility check is needed for allocators that
4113 -- constrain access discriminants. The level of the type of the
4114 -- expression used to constrain an access discriminant cannot be
4115 -- deeper than the type of the allocator (in contrast to access
4116 -- parameters, where the level of the actual can be arbitrary).
4117 -- We can't use Valid_Conversion to perform this check because
4118 -- in general the type of the allocator is unrelated to the type
4119 -- of the access discriminant.
4121 if Nkind (Original_Node (E)) = N_Subtype_Indication
4122 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4123 or else Is_Local_Anonymous_Access (Typ))
4125 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4127 if Has_Discriminants (Subtyp) then
4128 Discrim := First_Discriminant (Base_Type (Subtyp));
4129 Constr := First (Constraints (Constraint (Original_Node (E))));
4130 while Present (Discrim) and then Present (Constr) loop
4131 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4132 if Nkind (Constr) = N_Discriminant_Association then
4133 Disc_Exp := Original_Node (Expression (Constr));
4135 Disc_Exp := Original_Node (Constr);
4138 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4141 Next_Discriminant (Discrim);
4148 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4149 -- check that the level of the type of the created object is not deeper
4150 -- than the level of the allocator's access type, since extensions can
4151 -- now occur at deeper levels than their ancestor types. This is a
4152 -- static accessibility level check; a run-time check is also needed in
4153 -- the case of an initialized allocator with a class-wide argument (see
4154 -- Expand_Allocator_Expression).
4156 if Ada_Version >= Ada_05
4157 and then Is_Class_Wide_Type (Designated_Type (Typ))
4160 Exp_Typ : Entity_Id;
4163 if Nkind (E) = N_Qualified_Expression then
4164 Exp_Typ := Etype (E);
4165 elsif Nkind (E) = N_Subtype_Indication then
4166 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4168 Exp_Typ := Entity (E);
4171 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4172 if In_Instance_Body then
4173 Error_Msg_N ("?type in allocator has deeper level than" &
4174 " designated class-wide type", E);
4175 Error_Msg_N ("\?Program_Error will be raised at run time",
4178 Make_Raise_Program_Error (Sloc (N),
4179 Reason => PE_Accessibility_Check_Failed));
4182 -- Do not apply Ada 2005 accessibility checks on a class-wide
4183 -- allocator if the type given in the allocator is a formal
4184 -- type. A run-time check will be performed in the instance.
4186 elsif not Is_Generic_Type (Exp_Typ) then
4187 Error_Msg_N ("type in allocator has deeper level than" &
4188 " designated class-wide type", E);
4194 -- Check for allocation from an empty storage pool
4196 if No_Pool_Assigned (Typ) then
4198 Loc : constant Source_Ptr := Sloc (N);
4200 Error_Msg_N ("?allocation from empty storage pool!", N);
4201 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4203 Make_Raise_Storage_Error (Loc,
4204 Reason => SE_Empty_Storage_Pool));
4207 -- If the context is an unchecked conversion, as may happen within
4208 -- an inlined subprogram, the allocator is being resolved with its
4209 -- own anonymous type. In that case, if the target type has a specific
4210 -- storage pool, it must be inherited explicitly by the allocator type.
4212 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4213 and then No (Associated_Storage_Pool (Typ))
4215 Set_Associated_Storage_Pool
4216 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4219 -- An erroneous allocator may be rewritten as a raise Program_Error
4222 if Nkind (N) = N_Allocator then
4224 -- An anonymous access discriminant is the definition of a
4227 if Ekind (Typ) = E_Anonymous_Access_Type
4228 and then Nkind (Associated_Node_For_Itype (Typ)) =
4229 N_Discriminant_Specification
4231 -- Avoid marking an allocator as a dynamic coextension if it is
4232 -- within a static construct.
4234 if not Is_Static_Coextension (N) then
4235 Set_Is_Dynamic_Coextension (N);
4238 -- Cleanup for potential static coextensions
4241 Set_Is_Dynamic_Coextension (N, False);
4242 Set_Is_Static_Coextension (N, False);
4245 -- There is no need to propagate any nested coextensions if they
4246 -- are marked as static since they will be rewritten on the spot.
4248 if not Is_Static_Coextension (N) then
4249 Propagate_Coextensions (N);
4252 end Resolve_Allocator;
4254 ---------------------------
4255 -- Resolve_Arithmetic_Op --
4256 ---------------------------
4258 -- Used for resolving all arithmetic operators except exponentiation
4260 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4261 L : constant Node_Id := Left_Opnd (N);
4262 R : constant Node_Id := Right_Opnd (N);
4263 TL : constant Entity_Id := Base_Type (Etype (L));
4264 TR : constant Entity_Id := Base_Type (Etype (R));
4268 B_Typ : constant Entity_Id := Base_Type (Typ);
4269 -- We do the resolution using the base type, because intermediate values
4270 -- in expressions always are of the base type, not a subtype of it.
4272 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4273 -- Returns True if N is in a context that expects "any real type"
4275 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4276 -- Return True iff given type is Integer or universal real/integer
4278 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4279 -- Choose type of integer literal in fixed-point operation to conform
4280 -- to available fixed-point type. T is the type of the other operand,
4281 -- which is needed to determine the expected type of N.
4283 procedure Set_Operand_Type (N : Node_Id);
4284 -- Set operand type to T if universal
4286 -------------------------------
4287 -- Expected_Type_Is_Any_Real --
4288 -------------------------------
4290 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4292 -- N is the expression after "delta" in a fixed_point_definition;
4295 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4296 N_Decimal_Fixed_Point_Definition,
4298 -- N is one of the bounds in a real_range_specification;
4301 N_Real_Range_Specification,
4303 -- N is the expression of a delta_constraint;
4306 N_Delta_Constraint);
4307 end Expected_Type_Is_Any_Real;
4309 -----------------------------
4310 -- Is_Integer_Or_Universal --
4311 -----------------------------
4313 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4315 Index : Interp_Index;
4319 if not Is_Overloaded (N) then
4321 return Base_Type (T) = Base_Type (Standard_Integer)
4322 or else T = Universal_Integer
4323 or else T = Universal_Real;
4325 Get_First_Interp (N, Index, It);
4326 while Present (It.Typ) loop
4327 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4328 or else It.Typ = Universal_Integer
4329 or else It.Typ = Universal_Real
4334 Get_Next_Interp (Index, It);
4339 end Is_Integer_Or_Universal;
4341 ----------------------------
4342 -- Set_Mixed_Mode_Operand --
4343 ----------------------------
4345 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4346 Index : Interp_Index;
4350 if Universal_Interpretation (N) = Universal_Integer then
4352 -- A universal integer literal is resolved as standard integer
4353 -- except in the case of a fixed-point result, where we leave it
4354 -- as universal (to be handled by Exp_Fixd later on)
4356 if Is_Fixed_Point_Type (T) then
4357 Resolve (N, Universal_Integer);
4359 Resolve (N, Standard_Integer);
4362 elsif Universal_Interpretation (N) = Universal_Real
4363 and then (T = Base_Type (Standard_Integer)
4364 or else T = Universal_Integer
4365 or else T = Universal_Real)
4367 -- A universal real can appear in a fixed-type context. We resolve
4368 -- the literal with that context, even though this might raise an
4369 -- exception prematurely (the other operand may be zero).
4373 elsif Etype (N) = Base_Type (Standard_Integer)
4374 and then T = Universal_Real
4375 and then Is_Overloaded (N)
4377 -- Integer arg in mixed-mode operation. Resolve with universal
4378 -- type, in case preference rule must be applied.
4380 Resolve (N, Universal_Integer);
4383 and then B_Typ /= Universal_Fixed
4385 -- Not a mixed-mode operation, resolve with context
4389 elsif Etype (N) = Any_Fixed then
4391 -- N may itself be a mixed-mode operation, so use context type
4395 elsif Is_Fixed_Point_Type (T)
4396 and then B_Typ = Universal_Fixed
4397 and then Is_Overloaded (N)
4399 -- Must be (fixed * fixed) operation, operand must have one
4400 -- compatible interpretation.
4402 Resolve (N, Any_Fixed);
4404 elsif Is_Fixed_Point_Type (B_Typ)
4405 and then (T = Universal_Real
4406 or else Is_Fixed_Point_Type (T))
4407 and then Is_Overloaded (N)
4409 -- C * F(X) in a fixed context, where C is a real literal or a
4410 -- fixed-point expression. F must have either a fixed type
4411 -- interpretation or an integer interpretation, but not both.
4413 Get_First_Interp (N, Index, It);
4414 while Present (It.Typ) loop
4415 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4417 if Analyzed (N) then
4418 Error_Msg_N ("ambiguous operand in fixed operation", N);
4420 Resolve (N, Standard_Integer);
4423 elsif Is_Fixed_Point_Type (It.Typ) then
4425 if Analyzed (N) then
4426 Error_Msg_N ("ambiguous operand in fixed operation", N);
4428 Resolve (N, It.Typ);
4432 Get_Next_Interp (Index, It);
4435 -- Reanalyze the literal with the fixed type of the context. If
4436 -- context is Universal_Fixed, we are within a conversion, leave
4437 -- the literal as a universal real because there is no usable
4438 -- fixed type, and the target of the conversion plays no role in
4452 if B_Typ = Universal_Fixed
4453 and then Nkind (Op2) = N_Real_Literal
4455 T2 := Universal_Real;
4460 Set_Analyzed (Op2, False);
4467 end Set_Mixed_Mode_Operand;
4469 ----------------------
4470 -- Set_Operand_Type --
4471 ----------------------
4473 procedure Set_Operand_Type (N : Node_Id) is
4475 if Etype (N) = Universal_Integer
4476 or else Etype (N) = Universal_Real
4480 end Set_Operand_Type;
4482 -- Start of processing for Resolve_Arithmetic_Op
4485 if Comes_From_Source (N)
4486 and then Ekind (Entity (N)) = E_Function
4487 and then Is_Imported (Entity (N))
4488 and then Is_Intrinsic_Subprogram (Entity (N))
4490 Resolve_Intrinsic_Operator (N, Typ);
4493 -- Special-case for mixed-mode universal expressions or fixed point
4494 -- type operation: each argument is resolved separately. The same
4495 -- treatment is required if one of the operands of a fixed point
4496 -- operation is universal real, since in this case we don't do a
4497 -- conversion to a specific fixed-point type (instead the expander
4498 -- takes care of the case).
4500 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4501 and then Present (Universal_Interpretation (L))
4502 and then Present (Universal_Interpretation (R))
4504 Resolve (L, Universal_Interpretation (L));
4505 Resolve (R, Universal_Interpretation (R));
4506 Set_Etype (N, B_Typ);
4508 elsif (B_Typ = Universal_Real
4509 or else Etype (N) = Universal_Fixed
4510 or else (Etype (N) = Any_Fixed
4511 and then Is_Fixed_Point_Type (B_Typ))
4512 or else (Is_Fixed_Point_Type (B_Typ)
4513 and then (Is_Integer_Or_Universal (L)
4515 Is_Integer_Or_Universal (R))))
4516 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4518 if TL = Universal_Integer or else TR = Universal_Integer then
4519 Check_For_Visible_Operator (N, B_Typ);
4522 -- If context is a fixed type and one operand is integer, the
4523 -- other is resolved with the type of the context.
4525 if Is_Fixed_Point_Type (B_Typ)
4526 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4527 or else TL = Universal_Integer)
4532 elsif Is_Fixed_Point_Type (B_Typ)
4533 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4534 or else TR = Universal_Integer)
4540 Set_Mixed_Mode_Operand (L, TR);
4541 Set_Mixed_Mode_Operand (R, TL);
4544 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4545 -- multiplying operators from being used when the expected type is
4546 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4547 -- some cases where the expected type is actually Any_Real;
4548 -- Expected_Type_Is_Any_Real takes care of that case.
4550 if Etype (N) = Universal_Fixed
4551 or else Etype (N) = Any_Fixed
4553 if B_Typ = Universal_Fixed
4554 and then not Expected_Type_Is_Any_Real (N)
4555 and then not Nkind_In (Parent (N), N_Type_Conversion,
4556 N_Unchecked_Type_Conversion)
4558 Error_Msg_N ("type cannot be determined from context!", N);
4559 Error_Msg_N ("\explicit conversion to result type required", N);
4561 Set_Etype (L, Any_Type);
4562 Set_Etype (R, Any_Type);
4565 if Ada_Version = Ada_83
4566 and then Etype (N) = Universal_Fixed
4568 Nkind_In (Parent (N), N_Type_Conversion,
4569 N_Unchecked_Type_Conversion)
4572 ("(Ada 83) fixed-point operation "
4573 & "needs explicit conversion", N);
4576 -- The expected type is "any real type" in contexts like
4577 -- type T is delta <universal_fixed-expression> ...
4578 -- in which case we need to set the type to Universal_Real
4579 -- so that static expression evaluation will work properly.
4581 if Expected_Type_Is_Any_Real (N) then
4582 Set_Etype (N, Universal_Real);
4584 Set_Etype (N, B_Typ);
4588 elsif Is_Fixed_Point_Type (B_Typ)
4589 and then (Is_Integer_Or_Universal (L)
4590 or else Nkind (L) = N_Real_Literal
4591 or else Nkind (R) = N_Real_Literal
4592 or else Is_Integer_Or_Universal (R))
4594 Set_Etype (N, B_Typ);
4596 elsif Etype (N) = Any_Fixed then
4598 -- If no previous errors, this is only possible if one operand
4599 -- is overloaded and the context is universal. Resolve as such.
4601 Set_Etype (N, B_Typ);
4605 if (TL = Universal_Integer or else TL = Universal_Real)
4607 (TR = Universal_Integer or else TR = Universal_Real)
4609 Check_For_Visible_Operator (N, B_Typ);
4612 -- If the context is Universal_Fixed and the operands are also
4613 -- universal fixed, this is an error, unless there is only one
4614 -- applicable fixed_point type (usually duration).
4616 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4617 T := Unique_Fixed_Point_Type (N);
4619 if T = Any_Type then
4632 -- If one of the arguments was resolved to a non-universal type.
4633 -- label the result of the operation itself with the same type.
4634 -- Do the same for the universal argument, if any.
4636 T := Intersect_Types (L, R);
4637 Set_Etype (N, Base_Type (T));
4638 Set_Operand_Type (L);
4639 Set_Operand_Type (R);
4642 Generate_Operator_Reference (N, Typ);
4643 Eval_Arithmetic_Op (N);
4645 -- Set overflow and division checking bit. Much cleverer code needed
4646 -- here eventually and perhaps the Resolve routines should be separated
4647 -- for the various arithmetic operations, since they will need
4648 -- different processing. ???
4650 if Nkind (N) in N_Op then
4651 if not Overflow_Checks_Suppressed (Etype (N)) then
4652 Enable_Overflow_Check (N);
4655 -- Give warning if explicit division by zero
4657 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4658 and then not Division_Checks_Suppressed (Etype (N))
4660 Rop := Right_Opnd (N);
4662 if Compile_Time_Known_Value (Rop)
4663 and then ((Is_Integer_Type (Etype (Rop))
4664 and then Expr_Value (Rop) = Uint_0)
4666 (Is_Real_Type (Etype (Rop))
4667 and then Expr_Value_R (Rop) = Ureal_0))
4669 -- Specialize the warning message according to the operation
4673 Apply_Compile_Time_Constraint_Error
4674 (N, "division by zero?", CE_Divide_By_Zero,
4675 Loc => Sloc (Right_Opnd (N)));
4678 Apply_Compile_Time_Constraint_Error
4679 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4680 Loc => Sloc (Right_Opnd (N)));
4683 Apply_Compile_Time_Constraint_Error
4684 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4685 Loc => Sloc (Right_Opnd (N)));
4687 -- Division by zero can only happen with division, rem,
4688 -- and mod operations.
4691 raise Program_Error;
4694 -- Otherwise just set the flag to check at run time
4697 Activate_Division_Check (N);
4701 -- If Restriction No_Implicit_Conditionals is active, then it is
4702 -- violated if either operand can be negative for mod, or for rem
4703 -- if both operands can be negative.
4705 if Restrictions.Set (No_Implicit_Conditionals)
4706 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4715 -- Set if corresponding operand might be negative
4719 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4720 LNeg := (not OK) or else Lo < 0;
4723 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4724 RNeg := (not OK) or else Lo < 0;
4726 -- Check if we will be generating conditionals. There are two
4727 -- cases where that can happen, first for REM, the only case
4728 -- is largest negative integer mod -1, where the division can
4729 -- overflow, but we still have to give the right result. The
4730 -- front end generates a test for this annoying case. Here we
4731 -- just test if both operands can be negative (that's what the
4732 -- expander does, so we match its logic here).
4734 -- The second case is mod where either operand can be negative.
4735 -- In this case, the back end has to generate additonal tests.
4737 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4739 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4741 Check_Restriction (No_Implicit_Conditionals, N);
4747 Check_Unset_Reference (L);
4748 Check_Unset_Reference (R);
4749 end Resolve_Arithmetic_Op;
4755 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4756 Loc : constant Source_Ptr := Sloc (N);
4757 Subp : constant Node_Id := Name (N);
4766 -- The context imposes a unique interpretation with type Typ on a
4767 -- procedure or function call. Find the entity of the subprogram that
4768 -- yields the expected type, and propagate the corresponding formal
4769 -- constraints on the actuals. The caller has established that an
4770 -- interpretation exists, and emitted an error if not unique.
4772 -- First deal with the case of a call to an access-to-subprogram,
4773 -- dereference made explicit in Analyze_Call.
4775 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4776 if not Is_Overloaded (Subp) then
4777 Nam := Etype (Subp);
4780 -- Find the interpretation whose type (a subprogram type) has a
4781 -- return type that is compatible with the context. Analysis of
4782 -- the node has established that one exists.
4786 Get_First_Interp (Subp, I, It);
4787 while Present (It.Typ) loop
4788 if Covers (Typ, Etype (It.Typ)) then
4793 Get_Next_Interp (I, It);
4797 raise Program_Error;
4801 -- If the prefix is not an entity, then resolve it
4803 if not Is_Entity_Name (Subp) then
4804 Resolve (Subp, Nam);
4807 -- For an indirect call, we always invalidate checks, since we do not
4808 -- know whether the subprogram is local or global. Yes we could do
4809 -- better here, e.g. by knowing that there are no local subprograms,
4810 -- but it does not seem worth the effort. Similarly, we kill all
4811 -- knowledge of current constant values.
4813 Kill_Current_Values;
4815 -- If this is a procedure call which is really an entry call, do
4816 -- the conversion of the procedure call to an entry call. Protected
4817 -- operations use the same circuitry because the name in the call
4818 -- can be an arbitrary expression with special resolution rules.
4820 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4821 or else (Is_Entity_Name (Subp)
4822 and then Ekind (Entity (Subp)) = E_Entry)
4824 Resolve_Entry_Call (N, Typ);
4825 Check_Elab_Call (N);
4827 -- Kill checks and constant values, as above for indirect case
4828 -- Who knows what happens when another task is activated?
4830 Kill_Current_Values;
4833 -- Normal subprogram call with name established in Resolve
4835 elsif not (Is_Type (Entity (Subp))) then
4836 Nam := Entity (Subp);
4837 Set_Entity_With_Style_Check (Subp, Nam);
4839 -- Otherwise we must have the case of an overloaded call
4842 pragma Assert (Is_Overloaded (Subp));
4844 -- Initialize Nam to prevent warning (we know it will be assigned
4845 -- in the loop below, but the compiler does not know that).
4849 Get_First_Interp (Subp, I, It);
4850 while Present (It.Typ) loop
4851 if Covers (Typ, It.Typ) then
4853 Set_Entity_With_Style_Check (Subp, Nam);
4857 Get_Next_Interp (I, It);
4861 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4862 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4863 and then Nkind (Subp) /= N_Explicit_Dereference
4864 and then Present (Parameter_Associations (N))
4866 -- The prefix is a parameterless function call that returns an access
4867 -- to subprogram. If parameters are present in the current call, add
4868 -- add an explicit dereference. We use the base type here because
4869 -- within an instance these may be subtypes.
4871 -- The dereference is added either in Analyze_Call or here. Should
4872 -- be consolidated ???
4874 Set_Is_Overloaded (Subp, False);
4875 Set_Etype (Subp, Etype (Nam));
4876 Insert_Explicit_Dereference (Subp);
4877 Nam := Designated_Type (Etype (Nam));
4878 Resolve (Subp, Nam);
4881 -- Check that a call to Current_Task does not occur in an entry body
4883 if Is_RTE (Nam, RE_Current_Task) then
4892 -- Exclude calls that occur within the default of a formal
4893 -- parameter of the entry, since those are evaluated outside
4896 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4898 if Nkind (P) = N_Entry_Body
4899 or else (Nkind (P) = N_Subprogram_Body
4900 and then Is_Entry_Barrier_Function (P))
4904 ("?& should not be used in entry body (RM C.7(17))",
4907 ("\Program_Error will be raised at run time?", N, Nam);
4909 Make_Raise_Program_Error (Loc,
4910 Reason => PE_Current_Task_In_Entry_Body));
4911 Set_Etype (N, Rtype);
4918 -- Check that a procedure call does not occur in the context of the
4919 -- entry call statement of a conditional or timed entry call. Note that
4920 -- the case of a call to a subprogram renaming of an entry will also be
4921 -- rejected. The test for N not being an N_Entry_Call_Statement is
4922 -- defensive, covering the possibility that the processing of entry
4923 -- calls might reach this point due to later modifications of the code
4926 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4927 and then Nkind (N) /= N_Entry_Call_Statement
4928 and then Entry_Call_Statement (Parent (N)) = N
4930 if Ada_Version < Ada_05 then
4931 Error_Msg_N ("entry call required in select statement", N);
4933 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4934 -- for a procedure_or_entry_call, the procedure_name or
4935 -- procedure_prefix of the procedure_call_statement shall denote
4936 -- an entry renamed by a procedure, or (a view of) a primitive
4937 -- subprogram of a limited interface whose first parameter is
4938 -- a controlling parameter.
4940 elsif Nkind (N) = N_Procedure_Call_Statement
4941 and then not Is_Renamed_Entry (Nam)
4942 and then not Is_Controlling_Limited_Procedure (Nam)
4945 ("entry call or dispatching primitive of interface required", N);
4949 -- Check that this is not a call to a protected procedure or entry from
4950 -- within a protected function.
4952 if Ekind (Current_Scope) = E_Function
4953 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4954 and then Ekind (Nam) /= E_Function
4955 and then Scope (Nam) = Scope (Current_Scope)
4957 Error_Msg_N ("within protected function, protected " &
4958 "object is constant", N);
4959 Error_Msg_N ("\cannot call operation that may modify it", N);
4962 -- Freeze the subprogram name if not in a spec-expression. Note that we
4963 -- freeze procedure calls as well as function calls. Procedure calls are
4964 -- not frozen according to the rules (RM 13.14(14)) because it is
4965 -- impossible to have a procedure call to a non-frozen procedure in pure
4966 -- Ada, but in the code that we generate in the expander, this rule
4967 -- needs extending because we can generate procedure calls that need
4970 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4971 Freeze_Expression (Subp);
4974 -- For a predefined operator, the type of the result is the type imposed
4975 -- by context, except for a predefined operation on universal fixed.
4976 -- Otherwise The type of the call is the type returned by the subprogram
4979 if Is_Predefined_Op (Nam) then
4980 if Etype (N) /= Universal_Fixed then
4984 -- If the subprogram returns an array type, and the context requires the
4985 -- component type of that array type, the node is really an indexing of
4986 -- the parameterless call. Resolve as such. A pathological case occurs
4987 -- when the type of the component is an access to the array type. In
4988 -- this case the call is truly ambiguous.
4990 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4992 ((Is_Array_Type (Etype (Nam))
4993 and then Covers (Typ, Component_Type (Etype (Nam))))
4994 or else (Is_Access_Type (Etype (Nam))
4995 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4998 Component_Type (Designated_Type (Etype (Nam))))))
5001 Index_Node : Node_Id;
5003 Ret_Type : constant Entity_Id := Etype (Nam);
5006 if Is_Access_Type (Ret_Type)
5007 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5010 ("cannot disambiguate function call and indexing", N);
5012 New_Subp := Relocate_Node (Subp);
5013 Set_Entity (Subp, Nam);
5015 if (Is_Array_Type (Ret_Type)
5016 and then Component_Type (Ret_Type) /= Any_Type)
5018 (Is_Access_Type (Ret_Type)
5020 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5022 if Needs_No_Actuals (Nam) then
5024 -- Indexed call to a parameterless function
5027 Make_Indexed_Component (Loc,
5029 Make_Function_Call (Loc,
5031 Expressions => Parameter_Associations (N));
5033 -- An Ada 2005 prefixed call to a primitive operation
5034 -- whose first parameter is the prefix. This prefix was
5035 -- prepended to the parameter list, which is actually a
5036 -- list of indices. Remove the prefix in order to build
5037 -- the proper indexed component.
5040 Make_Indexed_Component (Loc,
5042 Make_Function_Call (Loc,
5044 Parameter_Associations =>
5046 (Remove_Head (Parameter_Associations (N)))),
5047 Expressions => Parameter_Associations (N));
5050 -- Since we are correcting a node classification error made
5051 -- by the parser, we call Replace rather than Rewrite.
5053 Replace (N, Index_Node);
5054 Set_Etype (Prefix (N), Ret_Type);
5056 Resolve_Indexed_Component (N, Typ);
5057 Check_Elab_Call (Prefix (N));
5065 Set_Etype (N, Etype (Nam));
5068 -- In the case where the call is to an overloaded subprogram, Analyze
5069 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5070 -- such a case Normalize_Actuals needs to be called once more to order
5071 -- the actuals correctly. Otherwise the call will have the ordering
5072 -- given by the last overloaded subprogram whether this is the correct
5073 -- one being called or not.
5075 if Is_Overloaded (Subp) then
5076 Normalize_Actuals (N, Nam, False, Norm_OK);
5077 pragma Assert (Norm_OK);
5080 -- In any case, call is fully resolved now. Reset Overload flag, to
5081 -- prevent subsequent overload resolution if node is analyzed again
5083 Set_Is_Overloaded (Subp, False);
5084 Set_Is_Overloaded (N, False);
5086 -- If we are calling the current subprogram from immediately within its
5087 -- body, then that is the case where we can sometimes detect cases of
5088 -- infinite recursion statically. Do not try this in case restriction
5089 -- No_Recursion is in effect anyway, and do it only for source calls.
5091 if Comes_From_Source (N) then
5092 Scop := Current_Scope;
5094 -- Issue warning for possible infinite recursion in the absence
5095 -- of the No_Recursion restriction.
5098 and then not Restriction_Active (No_Recursion)
5099 and then Check_Infinite_Recursion (N)
5101 -- Here we detected and flagged an infinite recursion, so we do
5102 -- not need to test the case below for further warnings. Also if
5103 -- we now have a raise SE node, we are all done.
5105 if Nkind (N) = N_Raise_Storage_Error then
5109 -- If call is to immediately containing subprogram, then check for
5110 -- the case of a possible run-time detectable infinite recursion.
5113 Scope_Loop : while Scop /= Standard_Standard loop
5116 -- Although in general case, recursion is not statically
5117 -- checkable, the case of calling an immediately containing
5118 -- subprogram is easy to catch.
5120 Check_Restriction (No_Recursion, N);
5122 -- If the recursive call is to a parameterless subprogram,
5123 -- then even if we can't statically detect infinite
5124 -- recursion, this is pretty suspicious, and we output a
5125 -- warning. Furthermore, we will try later to detect some
5126 -- cases here at run time by expanding checking code (see
5127 -- Detect_Infinite_Recursion in package Exp_Ch6).
5129 -- If the recursive call is within a handler, do not emit a
5130 -- warning, because this is a common idiom: loop until input
5131 -- is correct, catch illegal input in handler and restart.
5133 if No (First_Formal (Nam))
5134 and then Etype (Nam) = Standard_Void_Type
5135 and then not Error_Posted (N)
5136 and then Nkind (Parent (N)) /= N_Exception_Handler
5138 -- For the case of a procedure call. We give the message
5139 -- only if the call is the first statement in a sequence
5140 -- of statements, or if all previous statements are
5141 -- simple assignments. This is simply a heuristic to
5142 -- decrease false positives, without losing too many good
5143 -- warnings. The idea is that these previous statements
5144 -- may affect global variables the procedure depends on.
5146 if Nkind (N) = N_Procedure_Call_Statement
5147 and then Is_List_Member (N)
5153 while Present (P) loop
5154 if Nkind (P) /= N_Assignment_Statement then
5163 -- Do not give warning if we are in a conditional context
5166 K : constant Node_Kind := Nkind (Parent (N));
5168 if (K = N_Loop_Statement
5169 and then Present (Iteration_Scheme (Parent (N))))
5170 or else K = N_If_Statement
5171 or else K = N_Elsif_Part
5172 or else K = N_Case_Statement_Alternative
5178 -- Here warning is to be issued
5180 Set_Has_Recursive_Call (Nam);
5182 ("?possible infinite recursion!", N);
5184 ("\?Storage_Error may be raised at run time!", N);
5190 Scop := Scope (Scop);
5191 end loop Scope_Loop;
5195 -- If subprogram name is a predefined operator, it was given in
5196 -- functional notation. Replace call node with operator node, so
5197 -- that actuals can be resolved appropriately.
5199 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5200 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5203 elsif Present (Alias (Nam))
5204 and then Is_Predefined_Op (Alias (Nam))
5206 Resolve_Actuals (N, Nam);
5207 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5211 -- Create a transient scope if the resulting type requires it
5213 -- There are several notable exceptions:
5215 -- a) In init procs, the transient scope overhead is not needed, and is
5216 -- even incorrect when the call is a nested initialization call for a
5217 -- component whose expansion may generate adjust calls. However, if the
5218 -- call is some other procedure call within an initialization procedure
5219 -- (for example a call to Create_Task in the init_proc of the task
5220 -- run-time record) a transient scope must be created around this call.
5222 -- b) Enumeration literal pseudo-calls need no transient scope
5224 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5225 -- functions) do not use the secondary stack even though the return
5226 -- type may be unconstrained.
5228 -- d) Calls to a build-in-place function, since such functions may
5229 -- allocate their result directly in a target object, and cases where
5230 -- the result does get allocated in the secondary stack are checked for
5231 -- within the specialized Exp_Ch6 procedures for expanding those
5232 -- build-in-place calls.
5234 -- e) If the subprogram is marked Inline_Always, then even if it returns
5235 -- an unconstrained type the call does not require use of the secondary
5236 -- stack. However, inlining will only take place if the body to inline
5237 -- is already present. It may not be available if e.g. the subprogram is
5238 -- declared in a child instance.
5240 -- If this is an initialization call for a type whose construction
5241 -- uses the secondary stack, and it is not a nested call to initialize
5242 -- a component, we do need to create a transient scope for it. We
5243 -- check for this by traversing the type in Check_Initialization_Call.
5246 and then Has_Pragma_Inline_Always (Nam)
5247 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5248 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5252 elsif Ekind (Nam) = E_Enumeration_Literal
5253 or else Is_Build_In_Place_Function (Nam)
5254 or else Is_Intrinsic_Subprogram (Nam)
5258 elsif Expander_Active
5259 and then Is_Type (Etype (Nam))
5260 and then Requires_Transient_Scope (Etype (Nam))
5262 (not Within_Init_Proc
5264 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5266 Establish_Transient_Scope (N, Sec_Stack => True);
5268 -- If the call appears within the bounds of a loop, it will
5269 -- be rewritten and reanalyzed, nothing left to do here.
5271 if Nkind (N) /= N_Function_Call then
5275 elsif Is_Init_Proc (Nam)
5276 and then not Within_Init_Proc
5278 Check_Initialization_Call (N, Nam);
5281 -- A protected function cannot be called within the definition of the
5282 -- enclosing protected type.
5284 if Is_Protected_Type (Scope (Nam))
5285 and then In_Open_Scopes (Scope (Nam))
5286 and then not Has_Completion (Scope (Nam))
5289 ("& cannot be called before end of protected definition", N, Nam);
5292 -- Propagate interpretation to actuals, and add default expressions
5295 if Present (First_Formal (Nam)) then
5296 Resolve_Actuals (N, Nam);
5298 -- Overloaded literals are rewritten as function calls, for purpose of
5299 -- resolution. After resolution, we can replace the call with the
5302 elsif Ekind (Nam) = E_Enumeration_Literal then
5303 Copy_Node (Subp, N);
5304 Resolve_Entity_Name (N, Typ);
5306 -- Avoid validation, since it is a static function call
5308 Generate_Reference (Nam, Subp);
5312 -- If the subprogram is not global, then kill all saved values and
5313 -- checks. This is a bit conservative, since in many cases we could do
5314 -- better, but it is not worth the effort. Similarly, we kill constant
5315 -- values. However we do not need to do this for internal entities
5316 -- (unless they are inherited user-defined subprograms), since they
5317 -- are not in the business of molesting local values.
5319 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5320 -- kill all checks and values for calls to global subprograms. This
5321 -- takes care of the case where an access to a local subprogram is
5322 -- taken, and could be passed directly or indirectly and then called
5323 -- from almost any context.
5325 -- Note: we do not do this step till after resolving the actuals. That
5326 -- way we still take advantage of the current value information while
5327 -- scanning the actuals.
5329 -- We suppress killing values if we are processing the nodes associated
5330 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5331 -- type kills all the values as part of analyzing the code that
5332 -- initializes the dispatch tables.
5334 if Inside_Freezing_Actions = 0
5335 and then (not Is_Library_Level_Entity (Nam)
5336 or else Suppress_Value_Tracking_On_Call
5337 (Nearest_Dynamic_Scope (Current_Scope)))
5338 and then (Comes_From_Source (Nam)
5339 or else (Present (Alias (Nam))
5340 and then Comes_From_Source (Alias (Nam))))
5342 Kill_Current_Values;
5345 -- If we are warning about unread OUT parameters, this is the place to
5346 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5347 -- after the above call to Kill_Current_Values (since that call clears
5348 -- the Last_Assignment field of all local variables).
5350 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5351 and then Comes_From_Source (N)
5352 and then In_Extended_Main_Source_Unit (N)
5359 F := First_Formal (Nam);
5360 A := First_Actual (N);
5361 while Present (F) and then Present (A) loop
5362 if (Ekind (F) = E_Out_Parameter
5364 Ekind (F) = E_In_Out_Parameter)
5365 and then Warn_On_Modified_As_Out_Parameter (F)
5366 and then Is_Entity_Name (A)
5367 and then Present (Entity (A))
5368 and then Comes_From_Source (N)
5369 and then Safe_To_Capture_Value (N, Entity (A))
5371 Set_Last_Assignment (Entity (A), A);
5380 -- If the subprogram is a primitive operation, check whether or not
5381 -- it is a correct dispatching call.
5383 if Is_Overloadable (Nam)
5384 and then Is_Dispatching_Operation (Nam)
5386 Check_Dispatching_Call (N);
5388 elsif Ekind (Nam) /= E_Subprogram_Type
5389 and then Is_Abstract_Subprogram (Nam)
5390 and then not In_Instance
5392 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5395 -- If this is a dispatching call, generate the appropriate reference,
5396 -- for better source navigation in GPS.
5398 if Is_Overloadable (Nam)
5399 and then Present (Controlling_Argument (N))
5401 Generate_Reference (Nam, Subp, 'R');
5403 -- Normal case, not a dispatching call
5406 Generate_Reference (Nam, Subp);
5409 if Is_Intrinsic_Subprogram (Nam) then
5410 Check_Intrinsic_Call (N);
5413 -- Check for violation of restriction No_Specific_Termination_Handlers
5414 -- and warn on a potentially blocking call to Abort_Task.
5416 if Is_RTE (Nam, RE_Set_Specific_Handler)
5418 Is_RTE (Nam, RE_Specific_Handler)
5420 Check_Restriction (No_Specific_Termination_Handlers, N);
5422 elsif Is_RTE (Nam, RE_Abort_Task) then
5423 Check_Potentially_Blocking_Operation (N);
5426 -- Issue an error for a call to an eliminated subprogram
5428 Check_For_Eliminated_Subprogram (Subp, Nam);
5430 -- All done, evaluate call and deal with elaboration issues
5433 Check_Elab_Call (N);
5434 Warn_On_Overlapping_Actuals (Nam, N);
5437 -------------------------------
5438 -- Resolve_Character_Literal --
5439 -------------------------------
5441 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5442 B_Typ : constant Entity_Id := Base_Type (Typ);
5446 -- Verify that the character does belong to the type of the context
5448 Set_Etype (N, B_Typ);
5449 Eval_Character_Literal (N);
5451 -- Wide_Wide_Character literals must always be defined, since the set
5452 -- of wide wide character literals is complete, i.e. if a character
5453 -- literal is accepted by the parser, then it is OK for wide wide
5454 -- character (out of range character literals are rejected).
5456 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5459 -- Always accept character literal for type Any_Character, which
5460 -- occurs in error situations and in comparisons of literals, both
5461 -- of which should accept all literals.
5463 elsif B_Typ = Any_Character then
5466 -- For Standard.Character or a type derived from it, check that
5467 -- the literal is in range
5469 elsif Root_Type (B_Typ) = Standard_Character then
5470 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5474 -- For Standard.Wide_Character or a type derived from it, check
5475 -- that the literal is in range
5477 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5478 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5482 -- For Standard.Wide_Wide_Character or a type derived from it, we
5483 -- know the literal is in range, since the parser checked!
5485 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5488 -- If the entity is already set, this has already been resolved in a
5489 -- generic context, or comes from expansion. Nothing else to do.
5491 elsif Present (Entity (N)) then
5494 -- Otherwise we have a user defined character type, and we can use the
5495 -- standard visibility mechanisms to locate the referenced entity.
5498 C := Current_Entity (N);
5499 while Present (C) loop
5500 if Etype (C) = B_Typ then
5501 Set_Entity_With_Style_Check (N, C);
5502 Generate_Reference (C, N);
5510 -- If we fall through, then the literal does not match any of the
5511 -- entries of the enumeration type. This isn't just a constraint
5512 -- error situation, it is an illegality (see RM 4.2).
5515 ("character not defined for }", N, First_Subtype (B_Typ));
5516 end Resolve_Character_Literal;
5518 ---------------------------
5519 -- Resolve_Comparison_Op --
5520 ---------------------------
5522 -- Context requires a boolean type, and plays no role in resolution.
5523 -- Processing identical to that for equality operators. The result
5524 -- type is the base type, which matters when pathological subtypes of
5525 -- booleans with limited ranges are used.
5527 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5528 L : constant Node_Id := Left_Opnd (N);
5529 R : constant Node_Id := Right_Opnd (N);
5533 -- If this is an intrinsic operation which is not predefined, use the
5534 -- types of its declared arguments to resolve the possibly overloaded
5535 -- operands. Otherwise the operands are unambiguous and specify the
5538 if Scope (Entity (N)) /= Standard_Standard then
5539 T := Etype (First_Entity (Entity (N)));
5542 T := Find_Unique_Type (L, R);
5544 if T = Any_Fixed then
5545 T := Unique_Fixed_Point_Type (L);
5549 Set_Etype (N, Base_Type (Typ));
5550 Generate_Reference (T, N, ' ');
5552 if T /= Any_Type then
5553 if T = Any_String or else
5554 T = Any_Composite or else
5557 if T = Any_Character then
5558 Ambiguous_Character (L);
5560 Error_Msg_N ("ambiguous operands for comparison", N);
5563 Set_Etype (N, Any_Type);
5569 Check_Unset_Reference (L);
5570 Check_Unset_Reference (R);
5571 Generate_Operator_Reference (N, T);
5572 Check_Low_Bound_Tested (N);
5573 Eval_Relational_Op (N);
5576 end Resolve_Comparison_Op;
5578 ------------------------------------
5579 -- Resolve_Conditional_Expression --
5580 ------------------------------------
5582 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5583 Condition : constant Node_Id := First (Expressions (N));
5584 Then_Expr : constant Node_Id := Next (Condition);
5585 Else_Expr : Node_Id := Next (Then_Expr);
5588 Resolve (Condition, Any_Boolean);
5589 Resolve (Then_Expr, Typ);
5591 -- If ELSE expression present, just resolve using the determined type
5593 if Present (Else_Expr) then
5594 Resolve (Else_Expr, Typ);
5596 -- If no ELSE expression is present, root type must be Standard.Boolean
5597 -- and we provide a Standard.True result converted to the appropriate
5598 -- Boolean type (in case it is a derived boolean type).
5600 elsif Root_Type (Typ) = Standard_Boolean then
5602 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5603 Analyze_And_Resolve (Else_Expr, Typ);
5604 Append_To (Expressions (N), Else_Expr);
5607 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5608 Append_To (Expressions (N), Error);
5612 Eval_Conditional_Expression (N);
5613 end Resolve_Conditional_Expression;
5615 -----------------------------------------
5616 -- Resolve_Discrete_Subtype_Indication --
5617 -----------------------------------------
5619 procedure Resolve_Discrete_Subtype_Indication
5627 Analyze (Subtype_Mark (N));
5628 S := Entity (Subtype_Mark (N));
5630 if Nkind (Constraint (N)) /= N_Range_Constraint then
5631 Error_Msg_N ("expect range constraint for discrete type", N);
5632 Set_Etype (N, Any_Type);
5635 R := Range_Expression (Constraint (N));
5643 if Base_Type (S) /= Base_Type (Typ) then
5645 ("expect subtype of }", N, First_Subtype (Typ));
5647 -- Rewrite the constraint as a range of Typ
5648 -- to allow compilation to proceed further.
5651 Rewrite (Low_Bound (R),
5652 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5653 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5654 Attribute_Name => Name_First));
5655 Rewrite (High_Bound (R),
5656 Make_Attribute_Reference (Sloc (High_Bound (R)),
5657 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5658 Attribute_Name => Name_First));
5662 Set_Etype (N, Etype (R));
5664 -- Additionally, we must check that the bounds are compatible
5665 -- with the given subtype, which might be different from the
5666 -- type of the context.
5668 Apply_Range_Check (R, S);
5670 -- ??? If the above check statically detects a Constraint_Error
5671 -- it replaces the offending bound(s) of the range R with a
5672 -- Constraint_Error node. When the itype which uses these bounds
5673 -- is frozen the resulting call to Duplicate_Subexpr generates
5674 -- a new temporary for the bounds.
5676 -- Unfortunately there are other itypes that are also made depend
5677 -- on these bounds, so when Duplicate_Subexpr is called they get
5678 -- a forward reference to the newly created temporaries and Gigi
5679 -- aborts on such forward references. This is probably sign of a
5680 -- more fundamental problem somewhere else in either the order of
5681 -- itype freezing or the way certain itypes are constructed.
5683 -- To get around this problem we call Remove_Side_Effects right
5684 -- away if either bounds of R are a Constraint_Error.
5687 L : constant Node_Id := Low_Bound (R);
5688 H : constant Node_Id := High_Bound (R);
5691 if Nkind (L) = N_Raise_Constraint_Error then
5692 Remove_Side_Effects (L);
5695 if Nkind (H) = N_Raise_Constraint_Error then
5696 Remove_Side_Effects (H);
5700 Check_Unset_Reference (Low_Bound (R));
5701 Check_Unset_Reference (High_Bound (R));
5704 end Resolve_Discrete_Subtype_Indication;
5706 -------------------------
5707 -- Resolve_Entity_Name --
5708 -------------------------
5710 -- Used to resolve identifiers and expanded names
5712 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5713 E : constant Entity_Id := Entity (N);
5716 -- If garbage from errors, set to Any_Type and return
5718 if No (E) and then Total_Errors_Detected /= 0 then
5719 Set_Etype (N, Any_Type);
5723 -- Replace named numbers by corresponding literals. Note that this is
5724 -- the one case where Resolve_Entity_Name must reset the Etype, since
5725 -- it is currently marked as universal.
5727 if Ekind (E) = E_Named_Integer then
5729 Eval_Named_Integer (N);
5731 elsif Ekind (E) = E_Named_Real then
5733 Eval_Named_Real (N);
5735 -- Allow use of subtype only if it is a concurrent type where we are
5736 -- currently inside the body. This will eventually be expanded into a
5737 -- call to Self (for tasks) or _object (for protected objects). Any
5738 -- other use of a subtype is invalid.
5740 elsif Is_Type (E) then
5741 if Is_Concurrent_Type (E)
5742 and then In_Open_Scopes (E)
5747 ("invalid use of subtype mark in expression or call", N);
5750 -- Check discriminant use if entity is discriminant in current scope,
5751 -- i.e. discriminant of record or concurrent type currently being
5752 -- analyzed. Uses in corresponding body are unrestricted.
5754 elsif Ekind (E) = E_Discriminant
5755 and then Scope (E) = Current_Scope
5756 and then not Has_Completion (Current_Scope)
5758 Check_Discriminant_Use (N);
5760 -- A parameterless generic function cannot appear in a context that
5761 -- requires resolution.
5763 elsif Ekind (E) = E_Generic_Function then
5764 Error_Msg_N ("illegal use of generic function", N);
5766 elsif Ekind (E) = E_Out_Parameter
5767 and then Ada_Version = Ada_83
5768 and then (Nkind (Parent (N)) in N_Op
5769 or else (Nkind (Parent (N)) = N_Assignment_Statement
5770 and then N = Expression (Parent (N)))
5771 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5773 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5775 -- In all other cases, just do the possible static evaluation
5778 -- A deferred constant that appears in an expression must have a
5779 -- completion, unless it has been removed by in-place expansion of
5782 if Ekind (E) = E_Constant
5783 and then Comes_From_Source (E)
5784 and then No (Constant_Value (E))
5785 and then Is_Frozen (Etype (E))
5786 and then not In_Spec_Expression
5787 and then not Is_Imported (E)
5790 if No_Initialization (Parent (E))
5791 or else (Present (Full_View (E))
5792 and then No_Initialization (Parent (Full_View (E))))
5797 "deferred constant is frozen before completion", N);
5801 Eval_Entity_Name (N);
5803 end Resolve_Entity_Name;
5809 procedure Resolve_Entry (Entry_Name : Node_Id) is
5810 Loc : constant Source_Ptr := Sloc (Entry_Name);
5818 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5819 -- If the bounds of the entry family being called depend on task
5820 -- discriminants, build a new index subtype where a discriminant is
5821 -- replaced with the value of the discriminant of the target task.
5822 -- The target task is the prefix of the entry name in the call.
5824 -----------------------
5825 -- Actual_Index_Type --
5826 -----------------------
5828 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5829 Typ : constant Entity_Id := Entry_Index_Type (E);
5830 Tsk : constant Entity_Id := Scope (E);
5831 Lo : constant Node_Id := Type_Low_Bound (Typ);
5832 Hi : constant Node_Id := Type_High_Bound (Typ);
5835 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5836 -- If the bound is given by a discriminant, replace with a reference
5837 -- to the discriminant of the same name in the target task. If the
5838 -- entry name is the target of a requeue statement and the entry is
5839 -- in the current protected object, the bound to be used is the
5840 -- discriminal of the object (see apply_range_checks for details of
5841 -- the transformation).
5843 -----------------------------
5844 -- Actual_Discriminant_Ref --
5845 -----------------------------
5847 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5848 Typ : constant Entity_Id := Etype (Bound);
5852 Remove_Side_Effects (Bound);
5854 if not Is_Entity_Name (Bound)
5855 or else Ekind (Entity (Bound)) /= E_Discriminant
5859 elsif Is_Protected_Type (Tsk)
5860 and then In_Open_Scopes (Tsk)
5861 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5863 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5867 Make_Selected_Component (Loc,
5868 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5869 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5874 end Actual_Discriminant_Ref;
5876 -- Start of processing for Actual_Index_Type
5879 if not Has_Discriminants (Tsk)
5880 or else (not Is_Entity_Name (Lo)
5882 not Is_Entity_Name (Hi))
5884 return Entry_Index_Type (E);
5887 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5888 Set_Etype (New_T, Base_Type (Typ));
5889 Set_Size_Info (New_T, Typ);
5890 Set_RM_Size (New_T, RM_Size (Typ));
5891 Set_Scalar_Range (New_T,
5892 Make_Range (Sloc (Entry_Name),
5893 Low_Bound => Actual_Discriminant_Ref (Lo),
5894 High_Bound => Actual_Discriminant_Ref (Hi)));
5898 end Actual_Index_Type;
5900 -- Start of processing of Resolve_Entry
5903 -- Find name of entry being called, and resolve prefix of name
5904 -- with its own type. The prefix can be overloaded, and the name
5905 -- and signature of the entry must be taken into account.
5907 if Nkind (Entry_Name) = N_Indexed_Component then
5909 -- Case of dealing with entry family within the current tasks
5911 E_Name := Prefix (Entry_Name);
5914 E_Name := Entry_Name;
5917 if Is_Entity_Name (E_Name) then
5919 -- Entry call to an entry (or entry family) in the current task. This
5920 -- is legal even though the task will deadlock. Rewrite as call to
5923 -- This can also be a call to an entry in an enclosing task. If this
5924 -- is a single task, we have to retrieve its name, because the scope
5925 -- of the entry is the task type, not the object. If the enclosing
5926 -- task is a task type, the identity of the task is given by its own
5929 -- Finally this can be a requeue on an entry of the same task or
5930 -- protected object.
5932 S := Scope (Entity (E_Name));
5934 for J in reverse 0 .. Scope_Stack.Last loop
5935 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5936 and then not Comes_From_Source (S)
5938 -- S is an enclosing task or protected object. The concurrent
5939 -- declaration has been converted into a type declaration, and
5940 -- the object itself has an object declaration that follows
5941 -- the type in the same declarative part.
5943 Tsk := Next_Entity (S);
5944 while Etype (Tsk) /= S loop
5951 elsif S = Scope_Stack.Table (J).Entity then
5953 -- Call to current task. Will be transformed into call to Self
5961 Make_Selected_Component (Loc,
5962 Prefix => New_Occurrence_Of (S, Loc),
5964 New_Occurrence_Of (Entity (E_Name), Loc));
5965 Rewrite (E_Name, New_N);
5968 elsif Nkind (Entry_Name) = N_Selected_Component
5969 and then Is_Overloaded (Prefix (Entry_Name))
5971 -- Use the entry name (which must be unique at this point) to find
5972 -- the prefix that returns the corresponding task type or protected
5976 Pref : constant Node_Id := Prefix (Entry_Name);
5977 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5982 Get_First_Interp (Pref, I, It);
5983 while Present (It.Typ) loop
5984 if Scope (Ent) = It.Typ then
5985 Set_Etype (Pref, It.Typ);
5989 Get_Next_Interp (I, It);
5994 if Nkind (Entry_Name) = N_Selected_Component then
5995 Resolve (Prefix (Entry_Name));
5997 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5998 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5999 Resolve (Prefix (Prefix (Entry_Name)));
6000 Index := First (Expressions (Entry_Name));
6001 Resolve (Index, Entry_Index_Type (Nam));
6003 -- Up to this point the expression could have been the actual in a
6004 -- simple entry call, and be given by a named association.
6006 if Nkind (Index) = N_Parameter_Association then
6007 Error_Msg_N ("expect expression for entry index", Index);
6009 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6014 ------------------------
6015 -- Resolve_Entry_Call --
6016 ------------------------
6018 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6019 Entry_Name : constant Node_Id := Name (N);
6020 Loc : constant Source_Ptr := Sloc (Entry_Name);
6022 First_Named : Node_Id;
6029 -- We kill all checks here, because it does not seem worth the effort to
6030 -- do anything better, an entry call is a big operation.
6034 -- Processing of the name is similar for entry calls and protected
6035 -- operation calls. Once the entity is determined, we can complete
6036 -- the resolution of the actuals.
6038 -- The selector may be overloaded, in the case of a protected object
6039 -- with overloaded functions. The type of the context is used for
6042 if Nkind (Entry_Name) = N_Selected_Component
6043 and then Is_Overloaded (Selector_Name (Entry_Name))
6044 and then Typ /= Standard_Void_Type
6051 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6052 while Present (It.Typ) loop
6053 if Covers (Typ, It.Typ) then
6054 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6055 Set_Etype (Entry_Name, It.Typ);
6057 Generate_Reference (It.Typ, N, ' ');
6060 Get_Next_Interp (I, It);
6065 Resolve_Entry (Entry_Name);
6067 if Nkind (Entry_Name) = N_Selected_Component then
6069 -- Simple entry call
6071 Nam := Entity (Selector_Name (Entry_Name));
6072 Obj := Prefix (Entry_Name);
6073 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6075 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6077 -- Call to member of entry family
6079 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6080 Obj := Prefix (Prefix (Entry_Name));
6081 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6084 -- We cannot in general check the maximum depth of protected entry
6085 -- calls at compile time. But we can tell that any protected entry
6086 -- call at all violates a specified nesting depth of zero.
6088 if Is_Protected_Type (Scope (Nam)) then
6089 Check_Restriction (Max_Entry_Queue_Length, N);
6092 -- Use context type to disambiguate a protected function that can be
6093 -- called without actuals and that returns an array type, and where
6094 -- the argument list may be an indexing of the returned value.
6096 if Ekind (Nam) = E_Function
6097 and then Needs_No_Actuals (Nam)
6098 and then Present (Parameter_Associations (N))
6100 ((Is_Array_Type (Etype (Nam))
6101 and then Covers (Typ, Component_Type (Etype (Nam))))
6103 or else (Is_Access_Type (Etype (Nam))
6104 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6105 and then Covers (Typ,
6106 Component_Type (Designated_Type (Etype (Nam))))))
6109 Index_Node : Node_Id;
6113 Make_Indexed_Component (Loc,
6115 Make_Function_Call (Loc,
6116 Name => Relocate_Node (Entry_Name)),
6117 Expressions => Parameter_Associations (N));
6119 -- Since we are correcting a node classification error made by
6120 -- the parser, we call Replace rather than Rewrite.
6122 Replace (N, Index_Node);
6123 Set_Etype (Prefix (N), Etype (Nam));
6125 Resolve_Indexed_Component (N, Typ);
6130 -- The operation name may have been overloaded. Order the actuals
6131 -- according to the formals of the resolved entity, and set the
6132 -- return type to that of the operation.
6135 Normalize_Actuals (N, Nam, False, Norm_OK);
6136 pragma Assert (Norm_OK);
6137 Set_Etype (N, Etype (Nam));
6140 Resolve_Actuals (N, Nam);
6141 Generate_Reference (Nam, Entry_Name);
6143 if Ekind (Nam) = E_Entry
6144 or else Ekind (Nam) = E_Entry_Family
6146 Check_Potentially_Blocking_Operation (N);
6149 -- Verify that a procedure call cannot masquerade as an entry
6150 -- call where an entry call is expected.
6152 if Ekind (Nam) = E_Procedure then
6153 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6154 and then N = Entry_Call_Statement (Parent (N))
6156 Error_Msg_N ("entry call required in select statement", N);
6158 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6159 and then N = Triggering_Statement (Parent (N))
6161 Error_Msg_N ("triggering statement cannot be procedure call", N);
6163 elsif Ekind (Scope (Nam)) = E_Task_Type
6164 and then not In_Open_Scopes (Scope (Nam))
6166 Error_Msg_N ("task has no entry with this name", Entry_Name);
6170 -- After resolution, entry calls and protected procedure calls are
6171 -- changed into entry calls, for expansion. The structure of the node
6172 -- does not change, so it can safely be done in place. Protected
6173 -- function calls must keep their structure because they are
6176 if Ekind (Nam) /= E_Function then
6178 -- A protected operation that is not a function may modify the
6179 -- corresponding object, and cannot apply to a constant. If this
6180 -- is an internal call, the prefix is the type itself.
6182 if Is_Protected_Type (Scope (Nam))
6183 and then not Is_Variable (Obj)
6184 and then (not Is_Entity_Name (Obj)
6185 or else not Is_Type (Entity (Obj)))
6188 ("prefix of protected procedure or entry call must be variable",
6192 Actuals := Parameter_Associations (N);
6193 First_Named := First_Named_Actual (N);
6196 Make_Entry_Call_Statement (Loc,
6198 Parameter_Associations => Actuals));
6200 Set_First_Named_Actual (N, First_Named);
6201 Set_Analyzed (N, True);
6203 -- Protected functions can return on the secondary stack, in which
6204 -- case we must trigger the transient scope mechanism.
6206 elsif Expander_Active
6207 and then Requires_Transient_Scope (Etype (Nam))
6209 Establish_Transient_Scope (N, Sec_Stack => True);
6211 end Resolve_Entry_Call;
6213 -------------------------
6214 -- Resolve_Equality_Op --
6215 -------------------------
6217 -- Both arguments must have the same type, and the boolean context does
6218 -- not participate in the resolution. The first pass verifies that the
6219 -- interpretation is not ambiguous, and the type of the left argument is
6220 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6221 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6222 -- though they carry a single (universal) type. Diagnose this case here.
6224 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6225 L : constant Node_Id := Left_Opnd (N);
6226 R : constant Node_Id := Right_Opnd (N);
6227 T : Entity_Id := Find_Unique_Type (L, R);
6229 function Find_Unique_Access_Type return Entity_Id;
6230 -- In the case of allocators, make a last-ditch attempt to find a single
6231 -- access type with the right designated type. This is semantically
6232 -- dubious, and of no interest to any real code, but c48008a makes it
6235 -----------------------------
6236 -- Find_Unique_Access_Type --
6237 -----------------------------
6239 function Find_Unique_Access_Type return Entity_Id is
6245 if Ekind (Etype (R)) = E_Allocator_Type then
6246 Acc := Designated_Type (Etype (R));
6247 elsif Ekind (Etype (L)) = E_Allocator_Type then
6248 Acc := Designated_Type (Etype (L));
6254 while S /= Standard_Standard loop
6255 E := First_Entity (S);
6256 while Present (E) loop
6258 and then Is_Access_Type (E)
6259 and then Ekind (E) /= E_Allocator_Type
6260 and then Designated_Type (E) = Base_Type (Acc)
6272 end Find_Unique_Access_Type;
6274 -- Start of processing for Resolve_Equality_Op
6277 Set_Etype (N, Base_Type (Typ));
6278 Generate_Reference (T, N, ' ');
6280 if T = Any_Fixed then
6281 T := Unique_Fixed_Point_Type (L);
6284 if T /= Any_Type then
6286 or else T = Any_Composite
6287 or else T = Any_Character
6289 if T = Any_Character then
6290 Ambiguous_Character (L);
6292 Error_Msg_N ("ambiguous operands for equality", N);
6295 Set_Etype (N, Any_Type);
6298 elsif T = Any_Access
6299 or else Ekind (T) = E_Allocator_Type
6300 or else Ekind (T) = E_Access_Attribute_Type
6302 T := Find_Unique_Access_Type;
6305 Error_Msg_N ("ambiguous operands for equality", N);
6306 Set_Etype (N, Any_Type);
6314 -- If the unique type is a class-wide type then it will be expanded
6315 -- into a dispatching call to the predefined primitive. Therefore we
6316 -- check here for potential violation of such restriction.
6318 if Is_Class_Wide_Type (T) then
6319 Check_Restriction (No_Dispatching_Calls, N);
6322 if Warn_On_Redundant_Constructs
6323 and then Comes_From_Source (N)
6324 and then Is_Entity_Name (R)
6325 and then Entity (R) = Standard_True
6326 and then Comes_From_Source (R)
6328 Error_Msg_N ("?comparison with True is redundant!", R);
6331 Check_Unset_Reference (L);
6332 Check_Unset_Reference (R);
6333 Generate_Operator_Reference (N, T);
6334 Check_Low_Bound_Tested (N);
6336 -- If this is an inequality, it may be the implicit inequality
6337 -- created for a user-defined operation, in which case the corres-
6338 -- ponding equality operation is not intrinsic, and the operation
6339 -- cannot be constant-folded. Else fold.
6341 if Nkind (N) = N_Op_Eq
6342 or else Comes_From_Source (Entity (N))
6343 or else Ekind (Entity (N)) = E_Operator
6344 or else Is_Intrinsic_Subprogram
6345 (Corresponding_Equality (Entity (N)))
6347 Eval_Relational_Op (N);
6349 elsif Nkind (N) = N_Op_Ne
6350 and then Is_Abstract_Subprogram (Entity (N))
6352 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6355 -- Ada 2005: If one operand is an anonymous access type, convert the
6356 -- other operand to it, to ensure that the underlying types match in
6357 -- the back-end. Same for access_to_subprogram, and the conversion
6358 -- verifies that the types are subtype conformant.
6360 -- We apply the same conversion in the case one of the operands is a
6361 -- private subtype of the type of the other.
6363 -- Why the Expander_Active test here ???
6367 (Ekind (T) = E_Anonymous_Access_Type
6368 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6369 or else Is_Private_Type (T))
6371 if Etype (L) /= T then
6373 Make_Unchecked_Type_Conversion (Sloc (L),
6374 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6375 Expression => Relocate_Node (L)));
6376 Analyze_And_Resolve (L, T);
6379 if (Etype (R)) /= T then
6381 Make_Unchecked_Type_Conversion (Sloc (R),
6382 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6383 Expression => Relocate_Node (R)));
6384 Analyze_And_Resolve (R, T);
6388 end Resolve_Equality_Op;
6390 ----------------------------------
6391 -- Resolve_Explicit_Dereference --
6392 ----------------------------------
6394 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6395 Loc : constant Source_Ptr := Sloc (N);
6397 P : constant Node_Id := Prefix (N);
6402 Check_Fully_Declared_Prefix (Typ, P);
6404 if Is_Overloaded (P) then
6406 -- Use the context type to select the prefix that has the correct
6409 Get_First_Interp (P, I, It);
6410 while Present (It.Typ) loop
6411 exit when Is_Access_Type (It.Typ)
6412 and then Covers (Typ, Designated_Type (It.Typ));
6413 Get_Next_Interp (I, It);
6416 if Present (It.Typ) then
6417 Resolve (P, It.Typ);
6419 -- If no interpretation covers the designated type of the prefix,
6420 -- this is the pathological case where not all implementations of
6421 -- the prefix allow the interpretation of the node as a call. Now
6422 -- that the expected type is known, Remove other interpretations
6423 -- from prefix, rewrite it as a call, and resolve again, so that
6424 -- the proper call node is generated.
6426 Get_First_Interp (P, I, It);
6427 while Present (It.Typ) loop
6428 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6432 Get_Next_Interp (I, It);
6436 Make_Function_Call (Loc,
6438 Make_Explicit_Dereference (Loc,
6440 Parameter_Associations => New_List);
6442 Save_Interps (N, New_N);
6444 Analyze_And_Resolve (N, Typ);
6448 Set_Etype (N, Designated_Type (It.Typ));
6454 if Is_Access_Type (Etype (P)) then
6455 Apply_Access_Check (N);
6458 -- If the designated type is a packed unconstrained array type, and the
6459 -- explicit dereference is not in the context of an attribute reference,
6460 -- then we must compute and set the actual subtype, since it is needed
6461 -- by Gigi. The reason we exclude the attribute case is that this is
6462 -- handled fine by Gigi, and in fact we use such attributes to build the
6463 -- actual subtype. We also exclude generated code (which builds actual
6464 -- subtypes directly if they are needed).
6466 if Is_Array_Type (Etype (N))
6467 and then Is_Packed (Etype (N))
6468 and then not Is_Constrained (Etype (N))
6469 and then Nkind (Parent (N)) /= N_Attribute_Reference
6470 and then Comes_From_Source (N)
6472 Set_Etype (N, Get_Actual_Subtype (N));
6475 -- Note: No Eval processing is required for an explicit dereference,
6476 -- because such a name can never be static.
6478 end Resolve_Explicit_Dereference;
6480 -------------------------------
6481 -- Resolve_Indexed_Component --
6482 -------------------------------
6484 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6485 Name : constant Node_Id := Prefix (N);
6487 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6491 if Is_Overloaded (Name) then
6493 -- Use the context type to select the prefix that yields the correct
6499 I1 : Interp_Index := 0;
6500 P : constant Node_Id := Prefix (N);
6501 Found : Boolean := False;
6504 Get_First_Interp (P, I, It);
6505 while Present (It.Typ) loop
6506 if (Is_Array_Type (It.Typ)
6507 and then Covers (Typ, Component_Type (It.Typ)))
6508 or else (Is_Access_Type (It.Typ)
6509 and then Is_Array_Type (Designated_Type (It.Typ))
6511 (Typ, Component_Type (Designated_Type (It.Typ))))
6514 It := Disambiguate (P, I1, I, Any_Type);
6516 if It = No_Interp then
6517 Error_Msg_N ("ambiguous prefix for indexing", N);
6523 Array_Type := It.Typ;
6529 Array_Type := It.Typ;
6534 Get_Next_Interp (I, It);
6539 Array_Type := Etype (Name);
6542 Resolve (Name, Array_Type);
6543 Array_Type := Get_Actual_Subtype_If_Available (Name);
6545 -- If prefix is access type, dereference to get real array type.
6546 -- Note: we do not apply an access check because the expander always
6547 -- introduces an explicit dereference, and the check will happen there.
6549 if Is_Access_Type (Array_Type) then
6550 Array_Type := Designated_Type (Array_Type);
6553 -- If name was overloaded, set component type correctly now
6554 -- If a misplaced call to an entry family (which has no index types)
6555 -- return. Error will be diagnosed from calling context.
6557 if Is_Array_Type (Array_Type) then
6558 Set_Etype (N, Component_Type (Array_Type));
6563 Index := First_Index (Array_Type);
6564 Expr := First (Expressions (N));
6566 -- The prefix may have resolved to a string literal, in which case its
6567 -- etype has a special representation. This is only possible currently
6568 -- if the prefix is a static concatenation, written in functional
6571 if Ekind (Array_Type) = E_String_Literal_Subtype then
6572 Resolve (Expr, Standard_Positive);
6575 while Present (Index) and Present (Expr) loop
6576 Resolve (Expr, Etype (Index));
6577 Check_Unset_Reference (Expr);
6579 if Is_Scalar_Type (Etype (Expr)) then
6580 Apply_Scalar_Range_Check (Expr, Etype (Index));
6582 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6590 -- Do not generate the warning on suspicious index if we are analyzing
6591 -- package Ada.Tags; otherwise we will report the warning with the
6592 -- Prims_Ptr field of the dispatch table.
6594 if Scope (Etype (Prefix (N))) = Standard_Standard
6596 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6599 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6600 Eval_Indexed_Component (N);
6602 end Resolve_Indexed_Component;
6604 -----------------------------
6605 -- Resolve_Integer_Literal --
6606 -----------------------------
6608 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6611 Eval_Integer_Literal (N);
6612 end Resolve_Integer_Literal;
6614 --------------------------------
6615 -- Resolve_Intrinsic_Operator --
6616 --------------------------------
6618 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6619 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6626 while Scope (Op) /= Standard_Standard loop
6628 pragma Assert (Present (Op));
6632 Set_Is_Overloaded (N, False);
6634 -- If the operand type is private, rewrite with suitable conversions on
6635 -- the operands and the result, to expose the proper underlying numeric
6638 if Is_Private_Type (Typ) then
6639 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6641 if Nkind (N) = N_Op_Expon then
6642 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6644 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6647 Save_Interps (Left_Opnd (N), Expression (Arg1));
6648 Save_Interps (Right_Opnd (N), Expression (Arg2));
6650 Set_Left_Opnd (N, Arg1);
6651 Set_Right_Opnd (N, Arg2);
6653 Set_Etype (N, Btyp);
6654 Rewrite (N, Unchecked_Convert_To (Typ, N));
6657 elsif Typ /= Etype (Left_Opnd (N))
6658 or else Typ /= Etype (Right_Opnd (N))
6660 -- Add explicit conversion where needed, and save interpretations in
6661 -- case operands are overloaded.
6663 Arg1 := Convert_To (Typ, Left_Opnd (N));
6664 Arg2 := Convert_To (Typ, Right_Opnd (N));
6666 if Nkind (Arg1) = N_Type_Conversion then
6667 Save_Interps (Left_Opnd (N), Expression (Arg1));
6669 Save_Interps (Left_Opnd (N), Arg1);
6672 if Nkind (Arg2) = N_Type_Conversion then
6673 Save_Interps (Right_Opnd (N), Expression (Arg2));
6675 Save_Interps (Right_Opnd (N), Arg2);
6678 Rewrite (Left_Opnd (N), Arg1);
6679 Rewrite (Right_Opnd (N), Arg2);
6682 Resolve_Arithmetic_Op (N, Typ);
6685 Resolve_Arithmetic_Op (N, Typ);
6687 end Resolve_Intrinsic_Operator;
6689 --------------------------------------
6690 -- Resolve_Intrinsic_Unary_Operator --
6691 --------------------------------------
6693 procedure Resolve_Intrinsic_Unary_Operator
6697 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6703 while Scope (Op) /= Standard_Standard loop
6705 pragma Assert (Present (Op));
6710 if Is_Private_Type (Typ) then
6711 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6712 Save_Interps (Right_Opnd (N), Expression (Arg2));
6714 Set_Right_Opnd (N, Arg2);
6716 Set_Etype (N, Btyp);
6717 Rewrite (N, Unchecked_Convert_To (Typ, N));
6721 Resolve_Unary_Op (N, Typ);
6723 end Resolve_Intrinsic_Unary_Operator;
6725 ------------------------
6726 -- Resolve_Logical_Op --
6727 ------------------------
6729 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6733 Check_No_Direct_Boolean_Operators (N);
6735 -- Predefined operations on scalar types yield the base type. On the
6736 -- other hand, logical operations on arrays yield the type of the
6737 -- arguments (and the context).
6739 if Is_Array_Type (Typ) then
6742 B_Typ := Base_Type (Typ);
6745 -- The following test is required because the operands of the operation
6746 -- may be literals, in which case the resulting type appears to be
6747 -- compatible with a signed integer type, when in fact it is compatible
6748 -- only with modular types. If the context itself is universal, the
6749 -- operation is illegal.
6751 if not Valid_Boolean_Arg (Typ) then
6752 Error_Msg_N ("invalid context for logical operation", N);
6753 Set_Etype (N, Any_Type);
6756 elsif Typ = Any_Modular then
6758 ("no modular type available in this context", N);
6759 Set_Etype (N, Any_Type);
6761 elsif Is_Modular_Integer_Type (Typ)
6762 and then Etype (Left_Opnd (N)) = Universal_Integer
6763 and then Etype (Right_Opnd (N)) = Universal_Integer
6765 Check_For_Visible_Operator (N, B_Typ);
6768 Resolve (Left_Opnd (N), B_Typ);
6769 Resolve (Right_Opnd (N), B_Typ);
6771 Check_Unset_Reference (Left_Opnd (N));
6772 Check_Unset_Reference (Right_Opnd (N));
6774 Set_Etype (N, B_Typ);
6775 Generate_Operator_Reference (N, B_Typ);
6776 Eval_Logical_Op (N);
6777 end Resolve_Logical_Op;
6779 ---------------------------
6780 -- Resolve_Membership_Op --
6781 ---------------------------
6783 -- The context can only be a boolean type, and does not determine
6784 -- the arguments. Arguments should be unambiguous, but the preference
6785 -- rule for universal types applies.
6787 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6788 pragma Warnings (Off, Typ);
6790 L : constant Node_Id := Left_Opnd (N);
6791 R : constant Node_Id := Right_Opnd (N);
6794 procedure Resolve_Set_Membership;
6795 -- Analysis has determined a unique type for the left operand.
6796 -- Use it to resolve the disjuncts.
6798 ----------------------------
6799 -- Resolve_Set_Membership --
6800 ----------------------------
6802 procedure Resolve_Set_Membership is
6806 Resolve (L, Etype (L));
6808 Alt := First (Alternatives (N));
6809 while Present (Alt) loop
6811 -- Alternative is an expression, a range
6812 -- or a subtype mark.
6814 if not Is_Entity_Name (Alt)
6815 or else not Is_Type (Entity (Alt))
6817 Resolve (Alt, Etype (L));
6822 end Resolve_Set_Membership;
6824 -- Start of processing for Resolve_Membership_Op
6827 if L = Error or else R = Error then
6831 if Present (Alternatives (N)) then
6832 Resolve_Set_Membership;
6835 elsif not Is_Overloaded (R)
6837 (Etype (R) = Universal_Integer or else
6838 Etype (R) = Universal_Real)
6839 and then Is_Overloaded (L)
6843 -- Ada 2005 (AI-251): Support the following case:
6845 -- type I is interface;
6846 -- type T is tagged ...
6848 -- function Test (O : I'Class) is
6850 -- return O in T'Class.
6853 -- In this case we have nothing else to do. The membership test will be
6854 -- done at run-time.
6856 elsif Ada_Version >= Ada_05
6857 and then Is_Class_Wide_Type (Etype (L))
6858 and then Is_Interface (Etype (L))
6859 and then Is_Class_Wide_Type (Etype (R))
6860 and then not Is_Interface (Etype (R))
6865 T := Intersect_Types (L, R);
6869 Check_Unset_Reference (L);
6871 if Nkind (R) = N_Range
6872 and then not Is_Scalar_Type (T)
6874 Error_Msg_N ("scalar type required for range", R);
6877 if Is_Entity_Name (R) then
6878 Freeze_Expression (R);
6881 Check_Unset_Reference (R);
6884 Eval_Membership_Op (N);
6885 end Resolve_Membership_Op;
6891 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6892 Loc : constant Source_Ptr := Sloc (N);
6895 -- Handle restriction against anonymous null access values This
6896 -- restriction can be turned off using -gnatdj.
6898 -- Ada 2005 (AI-231): Remove restriction
6900 if Ada_Version < Ada_05
6901 and then not Debug_Flag_J
6902 and then Ekind (Typ) = E_Anonymous_Access_Type
6903 and then Comes_From_Source (N)
6905 -- In the common case of a call which uses an explicitly null value
6906 -- for an access parameter, give specialized error message.
6908 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6912 ("null is not allowed as argument for an access parameter", N);
6914 -- Standard message for all other cases (are there any?)
6918 ("null cannot be of an anonymous access type", N);
6922 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6923 -- assignment to a null-excluding object
6925 if Ada_Version >= Ada_05
6926 and then Can_Never_Be_Null (Typ)
6927 and then Nkind (Parent (N)) = N_Assignment_Statement
6929 if not Inside_Init_Proc then
6931 (Compile_Time_Constraint_Error (N,
6932 "(Ada 2005) null not allowed in null-excluding objects?"),
6933 Make_Raise_Constraint_Error (Loc,
6934 Reason => CE_Access_Check_Failed));
6937 Make_Raise_Constraint_Error (Loc,
6938 Reason => CE_Access_Check_Failed));
6942 -- In a distributed context, null for a remote access to subprogram may
6943 -- need to be replaced with a special record aggregate. In this case,
6944 -- return after having done the transformation.
6946 if (Ekind (Typ) = E_Record_Type
6947 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6948 and then Remote_AST_Null_Value (N, Typ)
6953 -- The null literal takes its type from the context
6958 -----------------------
6959 -- Resolve_Op_Concat --
6960 -----------------------
6962 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6964 -- We wish to avoid deep recursion, because concatenations are often
6965 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6966 -- operands nonrecursively until we find something that is not a simple
6967 -- concatenation (A in this case). We resolve that, and then walk back
6968 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6969 -- to do the rest of the work at each level. The Parent pointers allow
6970 -- us to avoid recursion, and thus avoid running out of memory. See also
6971 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6977 -- The following code is equivalent to:
6979 -- Resolve_Op_Concat_First (NN, Typ);
6980 -- Resolve_Op_Concat_Arg (N, ...);
6981 -- Resolve_Op_Concat_Rest (N, Typ);
6983 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6984 -- operand is a concatenation.
6986 -- Walk down left operands
6989 Resolve_Op_Concat_First (NN, Typ);
6990 Op1 := Left_Opnd (NN);
6991 exit when not (Nkind (Op1) = N_Op_Concat
6992 and then not Is_Array_Type (Component_Type (Typ))
6993 and then Entity (Op1) = Entity (NN));
6997 -- Now (given the above example) NN is A&B and Op1 is A
6999 -- First resolve Op1 ...
7001 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7003 -- ... then walk NN back up until we reach N (where we started), calling
7004 -- Resolve_Op_Concat_Rest along the way.
7007 Resolve_Op_Concat_Rest (NN, Typ);
7011 end Resolve_Op_Concat;
7013 ---------------------------
7014 -- Resolve_Op_Concat_Arg --
7015 ---------------------------
7017 procedure Resolve_Op_Concat_Arg
7023 Btyp : constant Entity_Id := Base_Type (Typ);
7028 or else (not Is_Overloaded (Arg)
7029 and then Etype (Arg) /= Any_Composite
7030 and then Covers (Component_Type (Typ), Etype (Arg)))
7032 Resolve (Arg, Component_Type (Typ));
7034 Resolve (Arg, Btyp);
7037 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
7038 if Nkind (Arg) = N_Aggregate
7039 and then Is_Composite_Type (Component_Type (Typ))
7041 if Is_Private_Type (Component_Type (Typ)) then
7042 Resolve (Arg, Btyp);
7044 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7045 Set_Etype (Arg, Any_Type);
7049 if Is_Overloaded (Arg)
7050 and then Has_Compatible_Type (Arg, Typ)
7051 and then Etype (Arg) /= Any_Type
7059 Get_First_Interp (Arg, I, It);
7061 Get_Next_Interp (I, It);
7063 -- Special-case the error message when the overloading is
7064 -- caused by a function that yields an array and can be
7065 -- called without parameters.
7067 if It.Nam = Func then
7068 Error_Msg_Sloc := Sloc (Func);
7069 Error_Msg_N ("ambiguous call to function#", Arg);
7071 ("\\interpretation as call yields&", Arg, Typ);
7073 ("\\interpretation as indexing of call yields&",
7074 Arg, Component_Type (Typ));
7078 ("ambiguous operand for concatenation!", Arg);
7079 Get_First_Interp (Arg, I, It);
7080 while Present (It.Nam) loop
7081 Error_Msg_Sloc := Sloc (It.Nam);
7083 if Base_Type (It.Typ) = Base_Type (Typ)
7084 or else Base_Type (It.Typ) =
7085 Base_Type (Component_Type (Typ))
7087 Error_Msg_N -- CODEFIX
7088 ("\\possible interpretation#", Arg);
7091 Get_Next_Interp (I, It);
7097 Resolve (Arg, Component_Type (Typ));
7099 if Nkind (Arg) = N_String_Literal then
7100 Set_Etype (Arg, Component_Type (Typ));
7103 if Arg = Left_Opnd (N) then
7104 Set_Is_Component_Left_Opnd (N);
7106 Set_Is_Component_Right_Opnd (N);
7111 Resolve (Arg, Btyp);
7114 Check_Unset_Reference (Arg);
7115 end Resolve_Op_Concat_Arg;
7117 -----------------------------
7118 -- Resolve_Op_Concat_First --
7119 -----------------------------
7121 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7122 Btyp : constant Entity_Id := Base_Type (Typ);
7123 Op1 : constant Node_Id := Left_Opnd (N);
7124 Op2 : constant Node_Id := Right_Opnd (N);
7127 -- The parser folds an enormous sequence of concatenations of string
7128 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7129 -- in the right operand. If the expression resolves to a predefined "&"
7130 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7131 -- we give an error. See P_Simple_Expression in Par.Ch4.
7133 if Nkind (Op2) = N_String_Literal
7134 and then Is_Folded_In_Parser (Op2)
7135 and then Ekind (Entity (N)) = E_Function
7137 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7138 and then String_Length (Strval (Op1)) = 0);
7139 Error_Msg_N ("too many user-defined concatenations", N);
7143 Set_Etype (N, Btyp);
7145 if Is_Limited_Composite (Btyp) then
7146 Error_Msg_N ("concatenation not available for limited array", N);
7147 Explain_Limited_Type (Btyp, N);
7149 end Resolve_Op_Concat_First;
7151 ----------------------------
7152 -- Resolve_Op_Concat_Rest --
7153 ----------------------------
7155 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7156 Op1 : constant Node_Id := Left_Opnd (N);
7157 Op2 : constant Node_Id := Right_Opnd (N);
7160 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7162 Generate_Operator_Reference (N, Typ);
7164 if Is_String_Type (Typ) then
7165 Eval_Concatenation (N);
7168 -- If this is not a static concatenation, but the result is a string
7169 -- type (and not an array of strings) ensure that static string operands
7170 -- have their subtypes properly constructed.
7172 if Nkind (N) /= N_String_Literal
7173 and then Is_Character_Type (Component_Type (Typ))
7175 Set_String_Literal_Subtype (Op1, Typ);
7176 Set_String_Literal_Subtype (Op2, Typ);
7178 end Resolve_Op_Concat_Rest;
7180 ----------------------
7181 -- Resolve_Op_Expon --
7182 ----------------------
7184 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7185 B_Typ : constant Entity_Id := Base_Type (Typ);
7188 -- Catch attempts to do fixed-point exponentiation with universal
7189 -- operands, which is a case where the illegality is not caught during
7190 -- normal operator analysis.
7192 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7193 Error_Msg_N ("exponentiation not available for fixed point", N);
7197 if Comes_From_Source (N)
7198 and then Ekind (Entity (N)) = E_Function
7199 and then Is_Imported (Entity (N))
7200 and then Is_Intrinsic_Subprogram (Entity (N))
7202 Resolve_Intrinsic_Operator (N, Typ);
7206 if Etype (Left_Opnd (N)) = Universal_Integer
7207 or else Etype (Left_Opnd (N)) = Universal_Real
7209 Check_For_Visible_Operator (N, B_Typ);
7212 -- We do the resolution using the base type, because intermediate values
7213 -- in expressions always are of the base type, not a subtype of it.
7215 Resolve (Left_Opnd (N), B_Typ);
7216 Resolve (Right_Opnd (N), Standard_Integer);
7218 Check_Unset_Reference (Left_Opnd (N));
7219 Check_Unset_Reference (Right_Opnd (N));
7221 Set_Etype (N, B_Typ);
7222 Generate_Operator_Reference (N, B_Typ);
7225 -- Set overflow checking bit. Much cleverer code needed here eventually
7226 -- and perhaps the Resolve routines should be separated for the various
7227 -- arithmetic operations, since they will need different processing. ???
7229 if Nkind (N) in N_Op then
7230 if not Overflow_Checks_Suppressed (Etype (N)) then
7231 Enable_Overflow_Check (N);
7234 end Resolve_Op_Expon;
7236 --------------------
7237 -- Resolve_Op_Not --
7238 --------------------
7240 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7243 function Parent_Is_Boolean return Boolean;
7244 -- This function determines if the parent node is a boolean operator
7245 -- or operation (comparison op, membership test, or short circuit form)
7246 -- and the not in question is the left operand of this operation.
7247 -- Note that if the not is in parens, then false is returned.
7249 -----------------------
7250 -- Parent_Is_Boolean --
7251 -----------------------
7253 function Parent_Is_Boolean return Boolean is
7255 if Paren_Count (N) /= 0 then
7259 case Nkind (Parent (N)) is
7274 return Left_Opnd (Parent (N)) = N;
7280 end Parent_Is_Boolean;
7282 -- Start of processing for Resolve_Op_Not
7285 -- Predefined operations on scalar types yield the base type. On the
7286 -- other hand, logical operations on arrays yield the type of the
7287 -- arguments (and the context).
7289 if Is_Array_Type (Typ) then
7292 B_Typ := Base_Type (Typ);
7295 -- Straightforward case of incorrect arguments
7297 if not Valid_Boolean_Arg (Typ) then
7298 Error_Msg_N ("invalid operand type for operator&", N);
7299 Set_Etype (N, Any_Type);
7302 -- Special case of probable missing parens
7304 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7305 if Parent_Is_Boolean then
7307 ("operand of not must be enclosed in parentheses",
7311 ("no modular type available in this context", N);
7314 Set_Etype (N, Any_Type);
7317 -- OK resolution of not
7320 -- Warn if non-boolean types involved. This is a case like not a < b
7321 -- where a and b are modular, where we will get (not a) < b and most
7322 -- likely not (a < b) was intended.
7324 if Warn_On_Questionable_Missing_Parens
7325 and then not Is_Boolean_Type (Typ)
7326 and then Parent_Is_Boolean
7328 Error_Msg_N ("?not expression should be parenthesized here!", N);
7331 -- Warn on double negation if checking redundant constructs
7333 if Warn_On_Redundant_Constructs
7334 and then Comes_From_Source (N)
7335 and then Comes_From_Source (Right_Opnd (N))
7336 and then Root_Type (Typ) = Standard_Boolean
7337 and then Nkind (Right_Opnd (N)) = N_Op_Not
7339 Error_Msg_N ("redundant double negation?", N);
7342 -- Complete resolution and evaluation of NOT
7344 Resolve (Right_Opnd (N), B_Typ);
7345 Check_Unset_Reference (Right_Opnd (N));
7346 Set_Etype (N, B_Typ);
7347 Generate_Operator_Reference (N, B_Typ);
7352 -----------------------------
7353 -- Resolve_Operator_Symbol --
7354 -----------------------------
7356 -- Nothing to be done, all resolved already
7358 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7359 pragma Warnings (Off, N);
7360 pragma Warnings (Off, Typ);
7364 end Resolve_Operator_Symbol;
7366 ----------------------------------
7367 -- Resolve_Qualified_Expression --
7368 ----------------------------------
7370 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7371 pragma Warnings (Off, Typ);
7373 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7374 Expr : constant Node_Id := Expression (N);
7377 Resolve (Expr, Target_Typ);
7379 -- A qualified expression requires an exact match of the type,
7380 -- class-wide matching is not allowed. However, if the qualifying
7381 -- type is specific and the expression has a class-wide type, it
7382 -- may still be okay, since it can be the result of the expansion
7383 -- of a call to a dispatching function, so we also have to check
7384 -- class-wideness of the type of the expression's original node.
7386 if (Is_Class_Wide_Type (Target_Typ)
7388 (Is_Class_Wide_Type (Etype (Expr))
7389 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7390 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7392 Wrong_Type (Expr, Target_Typ);
7395 -- If the target type is unconstrained, then we reset the type of
7396 -- the result from the type of the expression. For other cases, the
7397 -- actual subtype of the expression is the target type.
7399 if Is_Composite_Type (Target_Typ)
7400 and then not Is_Constrained (Target_Typ)
7402 Set_Etype (N, Etype (Expr));
7405 Eval_Qualified_Expression (N);
7406 end Resolve_Qualified_Expression;
7412 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7413 L : constant Node_Id := Low_Bound (N);
7414 H : constant Node_Id := High_Bound (N);
7421 Check_Unset_Reference (L);
7422 Check_Unset_Reference (H);
7424 -- We have to check the bounds for being within the base range as
7425 -- required for a non-static context. Normally this is automatic and
7426 -- done as part of evaluating expressions, but the N_Range node is an
7427 -- exception, since in GNAT we consider this node to be a subexpression,
7428 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7429 -- this, but that would put the test on the main evaluation path for
7432 Check_Non_Static_Context (L);
7433 Check_Non_Static_Context (H);
7435 -- Check for an ambiguous range over character literals. This will
7436 -- happen with a membership test involving only literals.
7438 if Typ = Any_Character then
7439 Ambiguous_Character (L);
7440 Set_Etype (N, Any_Type);
7444 -- If bounds are static, constant-fold them, so size computations
7445 -- are identical between front-end and back-end. Do not perform this
7446 -- transformation while analyzing generic units, as type information
7447 -- would then be lost when reanalyzing the constant node in the
7450 if Is_Discrete_Type (Typ) and then Expander_Active then
7451 if Is_OK_Static_Expression (L) then
7452 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7455 if Is_OK_Static_Expression (H) then
7456 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7461 --------------------------
7462 -- Resolve_Real_Literal --
7463 --------------------------
7465 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7466 Actual_Typ : constant Entity_Id := Etype (N);
7469 -- Special processing for fixed-point literals to make sure that the
7470 -- value is an exact multiple of small where this is required. We
7471 -- skip this for the universal real case, and also for generic types.
7473 if Is_Fixed_Point_Type (Typ)
7474 and then Typ /= Universal_Fixed
7475 and then Typ /= Any_Fixed
7476 and then not Is_Generic_Type (Typ)
7479 Val : constant Ureal := Realval (N);
7480 Cintr : constant Ureal := Val / Small_Value (Typ);
7481 Cint : constant Uint := UR_Trunc (Cintr);
7482 Den : constant Uint := Norm_Den (Cintr);
7486 -- Case of literal is not an exact multiple of the Small
7490 -- For a source program literal for a decimal fixed-point
7491 -- type, this is statically illegal (RM 4.9(36)).
7493 if Is_Decimal_Fixed_Point_Type (Typ)
7494 and then Actual_Typ = Universal_Real
7495 and then Comes_From_Source (N)
7497 Error_Msg_N ("value has extraneous low order digits", N);
7500 -- Generate a warning if literal from source
7502 if Is_Static_Expression (N)
7503 and then Warn_On_Bad_Fixed_Value
7506 ("?static fixed-point value is not a multiple of Small!",
7510 -- Replace literal by a value that is the exact representation
7511 -- of a value of the type, i.e. a multiple of the small value,
7512 -- by truncation, since Machine_Rounds is false for all GNAT
7513 -- fixed-point types (RM 4.9(38)).
7515 Stat := Is_Static_Expression (N);
7517 Make_Real_Literal (Sloc (N),
7518 Realval => Small_Value (Typ) * Cint));
7520 Set_Is_Static_Expression (N, Stat);
7523 -- In all cases, set the corresponding integer field
7525 Set_Corresponding_Integer_Value (N, Cint);
7529 -- Now replace the actual type by the expected type as usual
7532 Eval_Real_Literal (N);
7533 end Resolve_Real_Literal;
7535 -----------------------
7536 -- Resolve_Reference --
7537 -----------------------
7539 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7540 P : constant Node_Id := Prefix (N);
7543 -- Replace general access with specific type
7545 if Ekind (Etype (N)) = E_Allocator_Type then
7546 Set_Etype (N, Base_Type (Typ));
7549 Resolve (P, Designated_Type (Etype (N)));
7551 -- If we are taking the reference of a volatile entity, then treat
7552 -- it as a potential modification of this entity. This is much too
7553 -- conservative, but is necessary because remove side effects can
7554 -- result in transformations of normal assignments into reference
7555 -- sequences that otherwise fail to notice the modification.
7557 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7558 Note_Possible_Modification (P, Sure => False);
7560 end Resolve_Reference;
7562 --------------------------------
7563 -- Resolve_Selected_Component --
7564 --------------------------------
7566 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7568 Comp1 : Entity_Id := Empty; -- prevent junk warning
7569 P : constant Node_Id := Prefix (N);
7570 S : constant Node_Id := Selector_Name (N);
7571 T : Entity_Id := Etype (P);
7573 I1 : Interp_Index := 0; -- prevent junk warning
7578 function Init_Component return Boolean;
7579 -- Check whether this is the initialization of a component within an
7580 -- init proc (by assignment or call to another init proc). If true,
7581 -- there is no need for a discriminant check.
7583 --------------------
7584 -- Init_Component --
7585 --------------------
7587 function Init_Component return Boolean is
7589 return Inside_Init_Proc
7590 and then Nkind (Prefix (N)) = N_Identifier
7591 and then Chars (Prefix (N)) = Name_uInit
7592 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7595 -- Start of processing for Resolve_Selected_Component
7598 if Is_Overloaded (P) then
7600 -- Use the context type to select the prefix that has a selector
7601 -- of the correct name and type.
7604 Get_First_Interp (P, I, It);
7606 Search : while Present (It.Typ) loop
7607 if Is_Access_Type (It.Typ) then
7608 T := Designated_Type (It.Typ);
7613 if Is_Record_Type (T) then
7615 -- The visible components of a class-wide type are those of
7618 if Is_Class_Wide_Type (T) then
7622 Comp := First_Entity (T);
7623 while Present (Comp) loop
7624 if Chars (Comp) = Chars (S)
7625 and then Covers (Etype (Comp), Typ)
7634 It := Disambiguate (P, I1, I, Any_Type);
7636 if It = No_Interp then
7638 ("ambiguous prefix for selected component", N);
7645 -- There may be an implicit dereference. Retrieve
7646 -- designated record type.
7648 if Is_Access_Type (It1.Typ) then
7649 T := Designated_Type (It1.Typ);
7654 if Scope (Comp1) /= T then
7656 -- Resolution chooses the new interpretation.
7657 -- Find the component with the right name.
7659 Comp1 := First_Entity (T);
7660 while Present (Comp1)
7661 and then Chars (Comp1) /= Chars (S)
7663 Comp1 := Next_Entity (Comp1);
7672 Comp := Next_Entity (Comp);
7677 Get_Next_Interp (I, It);
7680 Resolve (P, It1.Typ);
7682 Set_Entity_With_Style_Check (S, Comp1);
7685 -- Resolve prefix with its type
7690 -- Generate cross-reference. We needed to wait until full overloading
7691 -- resolution was complete to do this, since otherwise we can't tell if
7692 -- we are an lvalue or not.
7694 if May_Be_Lvalue (N) then
7695 Generate_Reference (Entity (S), S, 'm');
7697 Generate_Reference (Entity (S), S, 'r');
7700 -- If prefix is an access type, the node will be transformed into an
7701 -- explicit dereference during expansion. The type of the node is the
7702 -- designated type of that of the prefix.
7704 if Is_Access_Type (Etype (P)) then
7705 T := Designated_Type (Etype (P));
7706 Check_Fully_Declared_Prefix (T, P);
7711 if Has_Discriminants (T)
7712 and then (Ekind (Entity (S)) = E_Component
7714 Ekind (Entity (S)) = E_Discriminant)
7715 and then Present (Original_Record_Component (Entity (S)))
7716 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7717 and then Present (Discriminant_Checking_Func
7718 (Original_Record_Component (Entity (S))))
7719 and then not Discriminant_Checks_Suppressed (T)
7720 and then not Init_Component
7722 Set_Do_Discriminant_Check (N);
7725 if Ekind (Entity (S)) = E_Void then
7726 Error_Msg_N ("premature use of component", S);
7729 -- If the prefix is a record conversion, this may be a renamed
7730 -- discriminant whose bounds differ from those of the original
7731 -- one, so we must ensure that a range check is performed.
7733 if Nkind (P) = N_Type_Conversion
7734 and then Ekind (Entity (S)) = E_Discriminant
7735 and then Is_Discrete_Type (Typ)
7737 Set_Etype (N, Base_Type (Typ));
7740 -- Note: No Eval processing is required, because the prefix is of a
7741 -- record type, or protected type, and neither can possibly be static.
7743 end Resolve_Selected_Component;
7749 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7750 B_Typ : constant Entity_Id := Base_Type (Typ);
7751 L : constant Node_Id := Left_Opnd (N);
7752 R : constant Node_Id := Right_Opnd (N);
7755 -- We do the resolution using the base type, because intermediate values
7756 -- in expressions always are of the base type, not a subtype of it.
7759 Resolve (R, Standard_Natural);
7761 Check_Unset_Reference (L);
7762 Check_Unset_Reference (R);
7764 Set_Etype (N, B_Typ);
7765 Generate_Operator_Reference (N, B_Typ);
7769 ---------------------------
7770 -- Resolve_Short_Circuit --
7771 ---------------------------
7773 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7774 B_Typ : constant Entity_Id := Base_Type (Typ);
7775 L : constant Node_Id := Left_Opnd (N);
7776 R : constant Node_Id := Right_Opnd (N);
7782 -- Check for issuing warning for always False assert/check, this happens
7783 -- when assertions are turned off, in which case the pragma Assert/Check
7784 -- was transformed into:
7786 -- if False and then <condition> then ...
7788 -- and we detect this pattern
7790 if Warn_On_Assertion_Failure
7791 and then Is_Entity_Name (R)
7792 and then Entity (R) = Standard_False
7793 and then Nkind (Parent (N)) = N_If_Statement
7794 and then Nkind (N) = N_And_Then
7795 and then Is_Entity_Name (L)
7796 and then Entity (L) = Standard_False
7799 Orig : constant Node_Id := Original_Node (Parent (N));
7802 if Nkind (Orig) = N_Pragma
7803 and then Pragma_Name (Orig) = Name_Assert
7805 -- Don't want to warn if original condition is explicit False
7808 Expr : constant Node_Id :=
7811 (First (Pragma_Argument_Associations (Orig))));
7813 if Is_Entity_Name (Expr)
7814 and then Entity (Expr) = Standard_False
7818 -- Issue warning. Note that we don't want to make this
7819 -- an unconditional warning, because if the assert is
7820 -- within deleted code we do not want the warning. But
7821 -- we do not want the deletion of the IF/AND-THEN to
7822 -- take this message with it. We achieve this by making
7823 -- sure that the expanded code points to the Sloc of
7824 -- the expression, not the original pragma.
7826 Error_Msg_N ("?assertion would fail at run-time", Orig);
7830 -- Similar processing for Check pragma
7832 elsif Nkind (Orig) = N_Pragma
7833 and then Pragma_Name (Orig) = Name_Check
7835 -- Don't want to warn if original condition is explicit False
7838 Expr : constant Node_Id :=
7842 (Pragma_Argument_Associations (Orig)))));
7844 if Is_Entity_Name (Expr)
7845 and then Entity (Expr) = Standard_False
7849 Error_Msg_N ("?check would fail at run-time", Orig);
7856 -- Continue with processing of short circuit
7858 Check_Unset_Reference (L);
7859 Check_Unset_Reference (R);
7861 Set_Etype (N, B_Typ);
7862 Eval_Short_Circuit (N);
7863 end Resolve_Short_Circuit;
7869 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7870 Name : constant Node_Id := Prefix (N);
7871 Drange : constant Node_Id := Discrete_Range (N);
7872 Array_Type : Entity_Id := Empty;
7876 if Is_Overloaded (Name) then
7878 -- Use the context type to select the prefix that yields the correct
7883 I1 : Interp_Index := 0;
7885 P : constant Node_Id := Prefix (N);
7886 Found : Boolean := False;
7889 Get_First_Interp (P, I, It);
7890 while Present (It.Typ) loop
7891 if (Is_Array_Type (It.Typ)
7892 and then Covers (Typ, It.Typ))
7893 or else (Is_Access_Type (It.Typ)
7894 and then Is_Array_Type (Designated_Type (It.Typ))
7895 and then Covers (Typ, Designated_Type (It.Typ)))
7898 It := Disambiguate (P, I1, I, Any_Type);
7900 if It = No_Interp then
7901 Error_Msg_N ("ambiguous prefix for slicing", N);
7906 Array_Type := It.Typ;
7911 Array_Type := It.Typ;
7916 Get_Next_Interp (I, It);
7921 Array_Type := Etype (Name);
7924 Resolve (Name, Array_Type);
7926 if Is_Access_Type (Array_Type) then
7927 Apply_Access_Check (N);
7928 Array_Type := Designated_Type (Array_Type);
7930 -- If the prefix is an access to an unconstrained array, we must use
7931 -- the actual subtype of the object to perform the index checks. The
7932 -- object denoted by the prefix is implicit in the node, so we build
7933 -- an explicit representation for it in order to compute the actual
7936 if not Is_Constrained (Array_Type) then
7937 Remove_Side_Effects (Prefix (N));
7940 Obj : constant Node_Id :=
7941 Make_Explicit_Dereference (Sloc (N),
7942 Prefix => New_Copy_Tree (Prefix (N)));
7944 Set_Etype (Obj, Array_Type);
7945 Set_Parent (Obj, Parent (N));
7946 Array_Type := Get_Actual_Subtype (Obj);
7950 elsif Is_Entity_Name (Name)
7951 or else (Nkind (Name) = N_Function_Call
7952 and then not Is_Constrained (Etype (Name)))
7954 Array_Type := Get_Actual_Subtype (Name);
7956 -- If the name is a selected component that depends on discriminants,
7957 -- build an actual subtype for it. This can happen only when the name
7958 -- itself is overloaded; otherwise the actual subtype is created when
7959 -- the selected component is analyzed.
7961 elsif Nkind (Name) = N_Selected_Component
7962 and then Full_Analysis
7963 and then Depends_On_Discriminant (First_Index (Array_Type))
7966 Act_Decl : constant Node_Id :=
7967 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7969 Insert_Action (N, Act_Decl);
7970 Array_Type := Defining_Identifier (Act_Decl);
7973 -- Maybe this should just be "else", instead of checking for the
7974 -- specific case of slice??? This is needed for the case where
7975 -- the prefix is an Image attribute, which gets expanded to a
7976 -- slice, and so has a constrained subtype which we want to use
7977 -- for the slice range check applied below (the range check won't
7978 -- get done if the unconstrained subtype of the 'Image is used).
7980 elsif Nkind (Name) = N_Slice then
7981 Array_Type := Etype (Name);
7984 -- If name was overloaded, set slice type correctly now
7986 Set_Etype (N, Array_Type);
7988 -- If the range is specified by a subtype mark, no resolution is
7989 -- necessary. Else resolve the bounds, and apply needed checks.
7991 if not Is_Entity_Name (Drange) then
7992 Index := First_Index (Array_Type);
7993 Resolve (Drange, Base_Type (Etype (Index)));
7995 if Nkind (Drange) = N_Range
7997 -- Do not apply the range check to nodes associated with the
7998 -- frontend expansion of the dispatch table. We first check
7999 -- if Ada.Tags is already loaded to void the addition of an
8000 -- undesired dependence on such run-time unit.
8003 (not Tagged_Type_Expansion
8005 (RTU_Loaded (Ada_Tags)
8006 and then Nkind (Prefix (N)) = N_Selected_Component
8007 and then Present (Entity (Selector_Name (Prefix (N))))
8008 and then Entity (Selector_Name (Prefix (N))) =
8009 RTE_Record_Component (RE_Prims_Ptr)))
8011 Apply_Range_Check (Drange, Etype (Index));
8015 Set_Slice_Subtype (N);
8017 if Nkind (Drange) = N_Range then
8018 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8019 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8025 ----------------------------
8026 -- Resolve_String_Literal --
8027 ----------------------------
8029 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8030 C_Typ : constant Entity_Id := Component_Type (Typ);
8031 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8032 Loc : constant Source_Ptr := Sloc (N);
8033 Str : constant String_Id := Strval (N);
8034 Strlen : constant Nat := String_Length (Str);
8035 Subtype_Id : Entity_Id;
8036 Need_Check : Boolean;
8039 -- For a string appearing in a concatenation, defer creation of the
8040 -- string_literal_subtype until the end of the resolution of the
8041 -- concatenation, because the literal may be constant-folded away. This
8042 -- is a useful optimization for long concatenation expressions.
8044 -- If the string is an aggregate built for a single character (which
8045 -- happens in a non-static context) or a is null string to which special
8046 -- checks may apply, we build the subtype. Wide strings must also get a
8047 -- string subtype if they come from a one character aggregate. Strings
8048 -- generated by attributes might be static, but it is often hard to
8049 -- determine whether the enclosing context is static, so we generate
8050 -- subtypes for them as well, thus losing some rarer optimizations ???
8051 -- Same for strings that come from a static conversion.
8054 (Strlen = 0 and then Typ /= Standard_String)
8055 or else Nkind (Parent (N)) /= N_Op_Concat
8056 or else (N /= Left_Opnd (Parent (N))
8057 and then N /= Right_Opnd (Parent (N)))
8058 or else ((Typ = Standard_Wide_String
8059 or else Typ = Standard_Wide_Wide_String)
8060 and then Nkind (Original_Node (N)) /= N_String_Literal);
8062 -- If the resolving type is itself a string literal subtype, we can just
8063 -- reuse it, since there is no point in creating another.
8065 if Ekind (Typ) = E_String_Literal_Subtype then
8068 elsif Nkind (Parent (N)) = N_Op_Concat
8069 and then not Need_Check
8070 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8071 N_Attribute_Reference,
8072 N_Qualified_Expression,
8077 -- Otherwise we must create a string literal subtype. Note that the
8078 -- whole idea of string literal subtypes is simply to avoid the need
8079 -- for building a full fledged array subtype for each literal.
8082 Set_String_Literal_Subtype (N, Typ);
8083 Subtype_Id := Etype (N);
8086 if Nkind (Parent (N)) /= N_Op_Concat
8089 Set_Etype (N, Subtype_Id);
8090 Eval_String_Literal (N);
8093 if Is_Limited_Composite (Typ)
8094 or else Is_Private_Composite (Typ)
8096 Error_Msg_N ("string literal not available for private array", N);
8097 Set_Etype (N, Any_Type);
8101 -- The validity of a null string has been checked in the call to
8102 -- Eval_String_Literal.
8107 -- Always accept string literal with component type Any_Character, which
8108 -- occurs in error situations and in comparisons of literals, both of
8109 -- which should accept all literals.
8111 elsif R_Typ = Any_Character then
8114 -- If the type is bit-packed, then we always transform the string
8115 -- literal into a full fledged aggregate.
8117 elsif Is_Bit_Packed_Array (Typ) then
8120 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8123 -- For Standard.Wide_Wide_String, or any other type whose component
8124 -- type is Standard.Wide_Wide_Character, we know that all the
8125 -- characters in the string must be acceptable, since the parser
8126 -- accepted the characters as valid character literals.
8128 if R_Typ = Standard_Wide_Wide_Character then
8131 -- For the case of Standard.String, or any other type whose component
8132 -- type is Standard.Character, we must make sure that there are no
8133 -- wide characters in the string, i.e. that it is entirely composed
8134 -- of characters in range of type Character.
8136 -- If the string literal is the result of a static concatenation, the
8137 -- test has already been performed on the components, and need not be
8140 elsif R_Typ = Standard_Character
8141 and then Nkind (Original_Node (N)) /= N_Op_Concat
8143 for J in 1 .. Strlen loop
8144 if not In_Character_Range (Get_String_Char (Str, J)) then
8146 -- If we are out of range, post error. This is one of the
8147 -- very few places that we place the flag in the middle of
8148 -- a token, right under the offending wide character. Not
8149 -- quite clear if this is right wrt wide character encoding
8150 -- sequences, but it's only an error message!
8153 ("literal out of range of type Standard.Character",
8154 Source_Ptr (Int (Loc) + J));
8159 -- For the case of Standard.Wide_String, or any other type whose
8160 -- component type is Standard.Wide_Character, we must make sure that
8161 -- there are no wide characters in the string, i.e. that it is
8162 -- entirely composed of characters in range of type Wide_Character.
8164 -- If the string literal is the result of a static concatenation,
8165 -- the test has already been performed on the components, and need
8168 elsif R_Typ = Standard_Wide_Character
8169 and then Nkind (Original_Node (N)) /= N_Op_Concat
8171 for J in 1 .. Strlen loop
8172 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8174 -- If we are out of range, post error. This is one of the
8175 -- very few places that we place the flag in the middle of
8176 -- a token, right under the offending wide character.
8178 -- This is not quite right, because characters in general
8179 -- will take more than one character position ???
8182 ("literal out of range of type Standard.Wide_Character",
8183 Source_Ptr (Int (Loc) + J));
8188 -- If the root type is not a standard character, then we will convert
8189 -- the string into an aggregate and will let the aggregate code do
8190 -- the checking. Standard Wide_Wide_Character is also OK here.
8196 -- See if the component type of the array corresponding to the string
8197 -- has compile time known bounds. If yes we can directly check
8198 -- whether the evaluation of the string will raise constraint error.
8199 -- Otherwise we need to transform the string literal into the
8200 -- corresponding character aggregate and let the aggregate
8201 -- code do the checking.
8203 if Is_Standard_Character_Type (R_Typ) then
8205 -- Check for the case of full range, where we are definitely OK
8207 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8211 -- Here the range is not the complete base type range, so check
8214 Comp_Typ_Lo : constant Node_Id :=
8215 Type_Low_Bound (Component_Type (Typ));
8216 Comp_Typ_Hi : constant Node_Id :=
8217 Type_High_Bound (Component_Type (Typ));
8222 if Compile_Time_Known_Value (Comp_Typ_Lo)
8223 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8225 for J in 1 .. Strlen loop
8226 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8228 if Char_Val < Expr_Value (Comp_Typ_Lo)
8229 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8231 Apply_Compile_Time_Constraint_Error
8232 (N, "character out of range?", CE_Range_Check_Failed,
8233 Loc => Source_Ptr (Int (Loc) + J));
8243 -- If we got here we meed to transform the string literal into the
8244 -- equivalent qualified positional array aggregate. This is rather
8245 -- heavy artillery for this situation, but it is hard work to avoid.
8248 Lits : constant List_Id := New_List;
8249 P : Source_Ptr := Loc + 1;
8253 -- Build the character literals, we give them source locations that
8254 -- correspond to the string positions, which is a bit tricky given
8255 -- the possible presence of wide character escape sequences.
8257 for J in 1 .. Strlen loop
8258 C := Get_String_Char (Str, J);
8259 Set_Character_Literal_Name (C);
8262 Make_Character_Literal (P,
8264 Char_Literal_Value => UI_From_CC (C)));
8266 if In_Character_Range (C) then
8269 -- Should we have a call to Skip_Wide here ???
8277 Make_Qualified_Expression (Loc,
8278 Subtype_Mark => New_Reference_To (Typ, Loc),
8280 Make_Aggregate (Loc, Expressions => Lits)));
8282 Analyze_And_Resolve (N, Typ);
8284 end Resolve_String_Literal;
8286 -----------------------------
8287 -- Resolve_Subprogram_Info --
8288 -----------------------------
8290 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8293 end Resolve_Subprogram_Info;
8295 -----------------------------
8296 -- Resolve_Type_Conversion --
8297 -----------------------------
8299 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8300 Conv_OK : constant Boolean := Conversion_OK (N);
8301 Operand : constant Node_Id := Expression (N);
8302 Operand_Typ : constant Entity_Id := Etype (Operand);
8303 Target_Typ : constant Entity_Id := Etype (N);
8310 and then not Valid_Conversion (N, Target_Typ, Operand)
8315 if Etype (Operand) = Any_Fixed then
8317 -- Mixed-mode operation involving a literal. Context must be a fixed
8318 -- type which is applied to the literal subsequently.
8320 if Is_Fixed_Point_Type (Typ) then
8321 Set_Etype (Operand, Universal_Real);
8323 elsif Is_Numeric_Type (Typ)
8324 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8325 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8327 Etype (Left_Opnd (Operand)) = Universal_Real)
8329 -- Return if expression is ambiguous
8331 if Unique_Fixed_Point_Type (N) = Any_Type then
8334 -- If nothing else, the available fixed type is Duration
8337 Set_Etype (Operand, Standard_Duration);
8340 -- Resolve the real operand with largest available precision
8342 if Etype (Right_Opnd (Operand)) = Universal_Real then
8343 Rop := New_Copy_Tree (Right_Opnd (Operand));
8345 Rop := New_Copy_Tree (Left_Opnd (Operand));
8348 Resolve (Rop, Universal_Real);
8350 -- If the operand is a literal (it could be a non-static and
8351 -- illegal exponentiation) check whether the use of Duration
8352 -- is potentially inaccurate.
8354 if Nkind (Rop) = N_Real_Literal
8355 and then Realval (Rop) /= Ureal_0
8356 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8359 ("?universal real operand can only " &
8360 "be interpreted as Duration!",
8363 ("\?precision will be lost in the conversion!", Rop);
8366 elsif Is_Numeric_Type (Typ)
8367 and then Nkind (Operand) in N_Op
8368 and then Unique_Fixed_Point_Type (N) /= Any_Type
8370 Set_Etype (Operand, Standard_Duration);
8373 Error_Msg_N ("invalid context for mixed mode operation", N);
8374 Set_Etype (Operand, Any_Type);
8381 -- Note: we do the Eval_Type_Conversion call before applying the
8382 -- required checks for a subtype conversion. This is important, since
8383 -- both are prepared under certain circumstances to change the type
8384 -- conversion to a constraint error node, but in the case of
8385 -- Eval_Type_Conversion this may reflect an illegality in the static
8386 -- case, and we would miss the illegality (getting only a warning
8387 -- message), if we applied the type conversion checks first.
8389 Eval_Type_Conversion (N);
8391 -- Even when evaluation is not possible, we may be able to simplify the
8392 -- conversion or its expression. This needs to be done before applying
8393 -- checks, since otherwise the checks may use the original expression
8394 -- and defeat the simplifications. This is specifically the case for
8395 -- elimination of the floating-point Truncation attribute in
8396 -- float-to-int conversions.
8398 Simplify_Type_Conversion (N);
8400 -- If after evaluation we still have a type conversion, then we may need
8401 -- to apply checks required for a subtype conversion.
8403 -- Skip these type conversion checks if universal fixed operands
8404 -- operands involved, since range checks are handled separately for
8405 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8407 if Nkind (N) = N_Type_Conversion
8408 and then not Is_Generic_Type (Root_Type (Target_Typ))
8409 and then Target_Typ /= Universal_Fixed
8410 and then Operand_Typ /= Universal_Fixed
8412 Apply_Type_Conversion_Checks (N);
8415 -- Issue warning for conversion of simple object to its own type. We
8416 -- have to test the original nodes, since they may have been rewritten
8417 -- by various optimizations.
8419 Orig_N := Original_Node (N);
8421 if Warn_On_Redundant_Constructs
8422 and then Comes_From_Source (Orig_N)
8423 and then Nkind (Orig_N) = N_Type_Conversion
8424 and then not In_Instance
8426 Orig_N := Original_Node (Expression (Orig_N));
8427 Orig_T := Target_Typ;
8429 -- If the node is part of a larger expression, the Target_Type
8430 -- may not be the original type of the node if the context is a
8431 -- condition. Recover original type to see if conversion is needed.
8433 if Is_Boolean_Type (Orig_T)
8434 and then Nkind (Parent (N)) in N_Op
8436 Orig_T := Etype (Parent (N));
8439 if Is_Entity_Name (Orig_N)
8441 (Etype (Entity (Orig_N)) = Orig_T
8443 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8444 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8446 -- One more check, do not give warning if the analyzed conversion
8447 -- has an expression with non-static bounds, and the bounds of the
8448 -- target are static. This avoids junk warnings in cases where the
8449 -- conversion is necessary to establish staticness, for example in
8450 -- a case statement.
8452 if not Is_OK_Static_Subtype (Operand_Typ)
8453 and then Is_OK_Static_Subtype (Target_Typ)
8457 -- Here we give the redundant conversion warning
8460 Error_Msg_Node_2 := Orig_T;
8461 Error_Msg_NE -- CODEFIX
8462 ("?redundant conversion, & is of type &!",
8463 N, Entity (Orig_N));
8468 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8469 -- No need to perform any interface conversion if the type of the
8470 -- expression coincides with the target type.
8472 if Ada_Version >= Ada_05
8473 and then Expander_Active
8474 and then Operand_Typ /= Target_Typ
8477 Opnd : Entity_Id := Operand_Typ;
8478 Target : Entity_Id := Target_Typ;
8481 if Is_Access_Type (Opnd) then
8482 Opnd := Directly_Designated_Type (Opnd);
8485 if Is_Access_Type (Target_Typ) then
8486 Target := Directly_Designated_Type (Target);
8489 if Opnd = Target then
8492 -- Conversion from interface type
8494 elsif Is_Interface (Opnd) then
8496 -- Ada 2005 (AI-217): Handle entities from limited views
8498 if From_With_Type (Opnd) then
8499 Error_Msg_Qual_Level := 99;
8500 Error_Msg_NE ("missing WITH clause on package &", N,
8501 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8503 ("type conversions require visibility of the full view",
8506 elsif From_With_Type (Target)
8508 (Is_Access_Type (Target_Typ)
8509 and then Present (Non_Limited_View (Etype (Target))))
8511 Error_Msg_Qual_Level := 99;
8512 Error_Msg_NE ("missing WITH clause on package &", N,
8513 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8515 ("type conversions require visibility of the full view",
8519 Expand_Interface_Conversion (N, Is_Static => False);
8522 -- Conversion to interface type
8524 elsif Is_Interface (Target) then
8528 if Ekind (Opnd) = E_Protected_Subtype
8529 or else Ekind (Opnd) = E_Task_Subtype
8531 Opnd := Etype (Opnd);
8534 if not Interface_Present_In_Ancestor
8538 if Is_Class_Wide_Type (Opnd) then
8540 -- The static analysis is not enough to know if the
8541 -- interface is implemented or not. Hence we must pass
8542 -- the work to the expander to generate code to evaluate
8543 -- the conversion at run-time.
8545 Expand_Interface_Conversion (N, Is_Static => False);
8548 Error_Msg_Name_1 := Chars (Etype (Target));
8549 Error_Msg_Name_2 := Chars (Opnd);
8551 ("wrong interface conversion (% is not a progenitor " &
8556 Expand_Interface_Conversion (N);
8561 end Resolve_Type_Conversion;
8563 ----------------------
8564 -- Resolve_Unary_Op --
8565 ----------------------
8567 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8568 B_Typ : constant Entity_Id := Base_Type (Typ);
8569 R : constant Node_Id := Right_Opnd (N);
8575 -- Deal with intrinsic unary operators
8577 if Comes_From_Source (N)
8578 and then Ekind (Entity (N)) = E_Function
8579 and then Is_Imported (Entity (N))
8580 and then Is_Intrinsic_Subprogram (Entity (N))
8582 Resolve_Intrinsic_Unary_Operator (N, Typ);
8586 -- Deal with universal cases
8588 if Etype (R) = Universal_Integer
8590 Etype (R) = Universal_Real
8592 Check_For_Visible_Operator (N, B_Typ);
8595 Set_Etype (N, B_Typ);
8598 -- Generate warning for expressions like abs (x mod 2)
8600 if Warn_On_Redundant_Constructs
8601 and then Nkind (N) = N_Op_Abs
8603 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8605 if OK and then Hi >= Lo and then Lo >= 0 then
8607 ("?abs applied to known non-negative value has no effect", N);
8611 -- Deal with reference generation
8613 Check_Unset_Reference (R);
8614 Generate_Operator_Reference (N, B_Typ);
8617 -- Set overflow checking bit. Much cleverer code needed here eventually
8618 -- and perhaps the Resolve routines should be separated for the various
8619 -- arithmetic operations, since they will need different processing ???
8621 if Nkind (N) in N_Op then
8622 if not Overflow_Checks_Suppressed (Etype (N)) then
8623 Enable_Overflow_Check (N);
8627 -- Generate warning for expressions like -5 mod 3 for integers. No need
8628 -- to worry in the floating-point case, since parens do not affect the
8629 -- result so there is no point in giving in a warning.
8632 Norig : constant Node_Id := Original_Node (N);
8641 if Warn_On_Questionable_Missing_Parens
8642 and then Comes_From_Source (Norig)
8643 and then Is_Integer_Type (Typ)
8644 and then Nkind (Norig) = N_Op_Minus
8646 Rorig := Original_Node (Right_Opnd (Norig));
8648 -- We are looking for cases where the right operand is not
8649 -- parenthesized, and is a binary operator, multiply, divide, or
8650 -- mod. These are the cases where the grouping can affect results.
8652 if Paren_Count (Rorig) = 0
8653 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8655 -- For mod, we always give the warning, since the value is
8656 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8657 -- -(5 mod 315)). But for the other cases, the only concern is
8658 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8659 -- overflows, but (-2) * 64 does not). So we try to give the
8660 -- message only when overflow is possible.
8662 if Nkind (Rorig) /= N_Op_Mod
8663 and then Compile_Time_Known_Value (R)
8665 Val := Expr_Value (R);
8667 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8668 HB := Expr_Value (Type_High_Bound (Typ));
8670 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8673 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8674 LB := Expr_Value (Type_Low_Bound (Typ));
8676 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8679 -- Note that the test below is deliberately excluding the
8680 -- largest negative number, since that is a potentially
8681 -- troublesome case (e.g. -2 * x, where the result is the
8682 -- largest negative integer has an overflow with 2 * x).
8684 if Val > LB and then Val <= HB then
8689 -- For the multiplication case, the only case we have to worry
8690 -- about is when (-a)*b is exactly the largest negative number
8691 -- so that -(a*b) can cause overflow. This can only happen if
8692 -- a is a power of 2, and more generally if any operand is a
8693 -- constant that is not a power of 2, then the parentheses
8694 -- cannot affect whether overflow occurs. We only bother to
8695 -- test the left most operand
8697 -- Loop looking at left operands for one that has known value
8700 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8701 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8702 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8704 -- Operand value of 0 or 1 skips warning
8709 -- Otherwise check power of 2, if power of 2, warn, if
8710 -- anything else, skip warning.
8713 while Lval /= 2 loop
8714 if Lval mod 2 = 1 then
8725 -- Keep looking at left operands
8727 Opnd := Left_Opnd (Opnd);
8730 -- For rem or "/" we can only have a problematic situation
8731 -- if the divisor has a value of minus one or one. Otherwise
8732 -- overflow is impossible (divisor > 1) or we have a case of
8733 -- division by zero in any case.
8735 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8736 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8737 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8742 -- If we fall through warning should be issued
8745 ("?unary minus expression should be parenthesized here!", N);
8749 end Resolve_Unary_Op;
8751 ----------------------------------
8752 -- Resolve_Unchecked_Expression --
8753 ----------------------------------
8755 procedure Resolve_Unchecked_Expression
8760 Resolve (Expression (N), Typ, Suppress => All_Checks);
8762 end Resolve_Unchecked_Expression;
8764 ---------------------------------------
8765 -- Resolve_Unchecked_Type_Conversion --
8766 ---------------------------------------
8768 procedure Resolve_Unchecked_Type_Conversion
8772 pragma Warnings (Off, Typ);
8774 Operand : constant Node_Id := Expression (N);
8775 Opnd_Type : constant Entity_Id := Etype (Operand);
8778 -- Resolve operand using its own type
8780 Resolve (Operand, Opnd_Type);
8781 Eval_Unchecked_Conversion (N);
8783 end Resolve_Unchecked_Type_Conversion;
8785 ------------------------------
8786 -- Rewrite_Operator_As_Call --
8787 ------------------------------
8789 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8790 Loc : constant Source_Ptr := Sloc (N);
8791 Actuals : constant List_Id := New_List;
8795 if Nkind (N) in N_Binary_Op then
8796 Append (Left_Opnd (N), Actuals);
8799 Append (Right_Opnd (N), Actuals);
8802 Make_Function_Call (Sloc => Loc,
8803 Name => New_Occurrence_Of (Nam, Loc),
8804 Parameter_Associations => Actuals);
8806 Preserve_Comes_From_Source (New_N, N);
8807 Preserve_Comes_From_Source (Name (New_N), N);
8809 Set_Etype (N, Etype (Nam));
8810 end Rewrite_Operator_As_Call;
8812 ------------------------------
8813 -- Rewrite_Renamed_Operator --
8814 ------------------------------
8816 procedure Rewrite_Renamed_Operator
8821 Nam : constant Name_Id := Chars (Op);
8822 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8826 -- Rewrite the operator node using the real operator, not its renaming.
8827 -- Exclude user-defined intrinsic operations of the same name, which are
8828 -- treated separately and rewritten as calls.
8830 if Ekind (Op) /= E_Function
8831 or else Chars (N) /= Nam
8833 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8834 Set_Chars (Op_Node, Nam);
8835 Set_Etype (Op_Node, Etype (N));
8836 Set_Entity (Op_Node, Op);
8837 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8839 -- Indicate that both the original entity and its renaming are
8840 -- referenced at this point.
8842 Generate_Reference (Entity (N), N);
8843 Generate_Reference (Op, N);
8846 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8849 Rewrite (N, Op_Node);
8851 -- If the context type is private, add the appropriate conversions
8852 -- so that the operator is applied to the full view. This is done
8853 -- in the routines that resolve intrinsic operators,
8855 if Is_Intrinsic_Subprogram (Op)
8856 and then Is_Private_Type (Typ)
8859 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8860 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8861 Resolve_Intrinsic_Operator (N, Typ);
8863 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8864 Resolve_Intrinsic_Unary_Operator (N, Typ);
8871 elsif Ekind (Op) = E_Function
8872 and then Is_Intrinsic_Subprogram (Op)
8874 -- Operator renames a user-defined operator of the same name. Use
8875 -- the original operator in the node, which is the one that Gigi
8879 Set_Is_Overloaded (N, False);
8881 end Rewrite_Renamed_Operator;
8883 -----------------------
8884 -- Set_Slice_Subtype --
8885 -----------------------
8887 -- Build an implicit subtype declaration to represent the type delivered
8888 -- by the slice. This is an abbreviated version of an array subtype. We
8889 -- define an index subtype for the slice, using either the subtype name
8890 -- or the discrete range of the slice. To be consistent with index usage
8891 -- elsewhere, we create a list header to hold the single index. This list
8892 -- is not otherwise attached to the syntax tree.
8894 procedure Set_Slice_Subtype (N : Node_Id) is
8895 Loc : constant Source_Ptr := Sloc (N);
8896 Index_List : constant List_Id := New_List;
8898 Index_Subtype : Entity_Id;
8899 Index_Type : Entity_Id;
8900 Slice_Subtype : Entity_Id;
8901 Drange : constant Node_Id := Discrete_Range (N);
8904 if Is_Entity_Name (Drange) then
8905 Index_Subtype := Entity (Drange);
8908 -- We force the evaluation of a range. This is definitely needed in
8909 -- the renamed case, and seems safer to do unconditionally. Note in
8910 -- any case that since we will create and insert an Itype referring
8911 -- to this range, we must make sure any side effect removal actions
8912 -- are inserted before the Itype definition.
8914 if Nkind (Drange) = N_Range then
8915 Force_Evaluation (Low_Bound (Drange));
8916 Force_Evaluation (High_Bound (Drange));
8919 Index_Type := Base_Type (Etype (Drange));
8921 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8923 Set_Scalar_Range (Index_Subtype, Drange);
8924 Set_Etype (Index_Subtype, Index_Type);
8925 Set_Size_Info (Index_Subtype, Index_Type);
8926 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8929 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8931 Index := New_Occurrence_Of (Index_Subtype, Loc);
8932 Set_Etype (Index, Index_Subtype);
8933 Append (Index, Index_List);
8935 Set_First_Index (Slice_Subtype, Index);
8936 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8937 Set_Is_Constrained (Slice_Subtype, True);
8939 Check_Compile_Time_Size (Slice_Subtype);
8941 -- The Etype of the existing Slice node is reset to this slice subtype.
8942 -- Its bounds are obtained from its first index.
8944 Set_Etype (N, Slice_Subtype);
8946 -- In the packed case, this must be immediately frozen
8948 -- Couldn't we always freeze here??? and if we did, then the above
8949 -- call to Check_Compile_Time_Size could be eliminated, which would
8950 -- be nice, because then that routine could be made private to Freeze.
8952 -- Why the test for In_Spec_Expression here ???
8954 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8955 Freeze_Itype (Slice_Subtype, N);
8958 end Set_Slice_Subtype;
8960 --------------------------------
8961 -- Set_String_Literal_Subtype --
8962 --------------------------------
8964 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8965 Loc : constant Source_Ptr := Sloc (N);
8966 Low_Bound : constant Node_Id :=
8967 Type_Low_Bound (Etype (First_Index (Typ)));
8968 Subtype_Id : Entity_Id;
8971 if Nkind (N) /= N_String_Literal then
8975 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8976 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8977 (String_Length (Strval (N))));
8978 Set_Etype (Subtype_Id, Base_Type (Typ));
8979 Set_Is_Constrained (Subtype_Id);
8980 Set_Etype (N, Subtype_Id);
8982 if Is_OK_Static_Expression (Low_Bound) then
8984 -- The low bound is set from the low bound of the corresponding
8985 -- index type. Note that we do not store the high bound in the
8986 -- string literal subtype, but it can be deduced if necessary
8987 -- from the length and the low bound.
8989 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8992 Set_String_Literal_Low_Bound
8993 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8994 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8996 -- Build bona fide subtype for the string, and wrap it in an
8997 -- unchecked conversion, because the backend expects the
8998 -- String_Literal_Subtype to have a static lower bound.
9001 Index_List : constant List_Id := New_List;
9002 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9003 High_Bound : constant Node_Id :=
9005 Left_Opnd => New_Copy_Tree (Low_Bound),
9007 Make_Integer_Literal (Loc,
9008 String_Length (Strval (N)) - 1));
9009 Array_Subtype : Entity_Id;
9010 Index_Subtype : Entity_Id;
9016 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9017 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
9018 Set_Scalar_Range (Index_Subtype, Drange);
9019 Set_Parent (Drange, N);
9020 Analyze_And_Resolve (Drange, Index_Type);
9022 -- In the context, the Index_Type may already have a constraint,
9023 -- so use common base type on string subtype. The base type may
9024 -- be used when generating attributes of the string, for example
9025 -- in the context of a slice assignment.
9027 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9028 Set_Size_Info (Index_Subtype, Index_Type);
9029 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9031 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9033 Index := New_Occurrence_Of (Index_Subtype, Loc);
9034 Set_Etype (Index, Index_Subtype);
9035 Append (Index, Index_List);
9037 Set_First_Index (Array_Subtype, Index);
9038 Set_Etype (Array_Subtype, Base_Type (Typ));
9039 Set_Is_Constrained (Array_Subtype, True);
9042 Make_Unchecked_Type_Conversion (Loc,
9043 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9044 Expression => Relocate_Node (N)));
9045 Set_Etype (N, Array_Subtype);
9048 end Set_String_Literal_Subtype;
9050 ------------------------------
9051 -- Simplify_Type_Conversion --
9052 ------------------------------
9054 procedure Simplify_Type_Conversion (N : Node_Id) is
9056 if Nkind (N) = N_Type_Conversion then
9058 Operand : constant Node_Id := Expression (N);
9059 Target_Typ : constant Entity_Id := Etype (N);
9060 Opnd_Typ : constant Entity_Id := Etype (Operand);
9063 if Is_Floating_Point_Type (Opnd_Typ)
9065 (Is_Integer_Type (Target_Typ)
9066 or else (Is_Fixed_Point_Type (Target_Typ)
9067 and then Conversion_OK (N)))
9068 and then Nkind (Operand) = N_Attribute_Reference
9069 and then Attribute_Name (Operand) = Name_Truncation
9071 -- Special processing required if the conversion is the expression
9072 -- of a Truncation attribute reference. In this case we replace:
9074 -- ityp (ftyp'Truncation (x))
9080 -- with the Float_Truncate flag set, which is more efficient
9084 Relocate_Node (First (Expressions (Operand))));
9085 Set_Float_Truncate (N, True);
9089 end Simplify_Type_Conversion;
9091 -----------------------------
9092 -- Unique_Fixed_Point_Type --
9093 -----------------------------
9095 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
9096 T1 : Entity_Id := Empty;
9101 procedure Fixed_Point_Error;
9102 -- Give error messages for true ambiguity. Messages are posted on node
9103 -- N, and entities T1, T2 are the possible interpretations.
9105 -----------------------
9106 -- Fixed_Point_Error --
9107 -----------------------
9109 procedure Fixed_Point_Error is
9111 Error_Msg_N ("ambiguous universal_fixed_expression", N);
9112 Error_Msg_NE ("\\possible interpretation as}", N, T1);
9113 Error_Msg_NE ("\\possible interpretation as}", N, T2);
9114 end Fixed_Point_Error;
9116 -- Start of processing for Unique_Fixed_Point_Type
9119 -- The operations on Duration are visible, so Duration is always a
9120 -- possible interpretation.
9122 T1 := Standard_Duration;
9124 -- Look for fixed-point types in enclosing scopes
9126 Scop := Current_Scope;
9127 while Scop /= Standard_Standard loop
9128 T2 := First_Entity (Scop);
9129 while Present (T2) loop
9130 if Is_Fixed_Point_Type (T2)
9131 and then Current_Entity (T2) = T2
9132 and then Scope (Base_Type (T2)) = Scop
9134 if Present (T1) then
9145 Scop := Scope (Scop);
9148 -- Look for visible fixed type declarations in the context
9150 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
9151 while Present (Item) loop
9152 if Nkind (Item) = N_With_Clause then
9153 Scop := Entity (Name (Item));
9154 T2 := First_Entity (Scop);
9155 while Present (T2) loop
9156 if Is_Fixed_Point_Type (T2)
9157 and then Scope (Base_Type (T2)) = Scop
9158 and then (Is_Potentially_Use_Visible (T2)
9159 or else In_Use (T2))
9161 if Present (T1) then
9176 if Nkind (N) = N_Real_Literal then
9177 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9179 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9183 end Unique_Fixed_Point_Type;
9185 ----------------------
9186 -- Valid_Conversion --
9187 ----------------------
9189 function Valid_Conversion
9192 Operand : Node_Id) return Boolean
9194 Target_Type : constant Entity_Id := Base_Type (Target);
9195 Opnd_Type : Entity_Id := Etype (Operand);
9197 function Conversion_Check
9199 Msg : String) return Boolean;
9200 -- Little routine to post Msg if Valid is False, returns Valid value
9202 function Valid_Tagged_Conversion
9203 (Target_Type : Entity_Id;
9204 Opnd_Type : Entity_Id) return Boolean;
9205 -- Specifically test for validity of tagged conversions
9207 function Valid_Array_Conversion return Boolean;
9208 -- Check index and component conformance, and accessibility levels
9209 -- if the component types are anonymous access types (Ada 2005)
9211 ----------------------
9212 -- Conversion_Check --
9213 ----------------------
9215 function Conversion_Check
9217 Msg : String) return Boolean
9221 Error_Msg_N (Msg, Operand);
9225 end Conversion_Check;
9227 ----------------------------
9228 -- Valid_Array_Conversion --
9229 ----------------------------
9231 function Valid_Array_Conversion return Boolean
9233 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9234 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9236 Opnd_Index : Node_Id;
9237 Opnd_Index_Type : Entity_Id;
9239 Target_Comp_Type : constant Entity_Id :=
9240 Component_Type (Target_Type);
9241 Target_Comp_Base : constant Entity_Id :=
9242 Base_Type (Target_Comp_Type);
9244 Target_Index : Node_Id;
9245 Target_Index_Type : Entity_Id;
9248 -- Error if wrong number of dimensions
9251 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9254 ("incompatible number of dimensions for conversion", Operand);
9257 -- Number of dimensions matches
9260 -- Loop through indexes of the two arrays
9262 Target_Index := First_Index (Target_Type);
9263 Opnd_Index := First_Index (Opnd_Type);
9264 while Present (Target_Index) and then Present (Opnd_Index) loop
9265 Target_Index_Type := Etype (Target_Index);
9266 Opnd_Index_Type := Etype (Opnd_Index);
9268 -- Error if index types are incompatible
9270 if not (Is_Integer_Type (Target_Index_Type)
9271 and then Is_Integer_Type (Opnd_Index_Type))
9272 and then (Root_Type (Target_Index_Type)
9273 /= Root_Type (Opnd_Index_Type))
9276 ("incompatible index types for array conversion",
9281 Next_Index (Target_Index);
9282 Next_Index (Opnd_Index);
9285 -- If component types have same base type, all set
9287 if Target_Comp_Base = Opnd_Comp_Base then
9290 -- Here if base types of components are not the same. The only
9291 -- time this is allowed is if we have anonymous access types.
9293 -- The conversion of arrays of anonymous access types can lead
9294 -- to dangling pointers. AI-392 formalizes the accessibility
9295 -- checks that must be applied to such conversions to prevent
9296 -- out-of-scope references.
9299 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9301 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9302 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9304 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9306 if Type_Access_Level (Target_Type) <
9307 Type_Access_Level (Opnd_Type)
9309 if In_Instance_Body then
9310 Error_Msg_N ("?source array type " &
9311 "has deeper accessibility level than target", Operand);
9312 Error_Msg_N ("\?Program_Error will be raised at run time",
9315 Make_Raise_Program_Error (Sloc (N),
9316 Reason => PE_Accessibility_Check_Failed));
9317 Set_Etype (N, Target_Type);
9320 -- Conversion not allowed because of accessibility levels
9323 Error_Msg_N ("source array type " &
9324 "has deeper accessibility level than target", Operand);
9331 -- All other cases where component base types do not match
9335 ("incompatible component types for array conversion",
9340 -- Check that component subtypes statically match. For numeric
9341 -- types this means that both must be either constrained or
9342 -- unconstrained. For enumeration types the bounds must match.
9343 -- All of this is checked in Subtypes_Statically_Match.
9345 if not Subtypes_Statically_Match
9346 (Target_Comp_Type, Opnd_Comp_Type)
9349 ("component subtypes must statically match", Operand);
9355 end Valid_Array_Conversion;
9357 -----------------------------
9358 -- Valid_Tagged_Conversion --
9359 -----------------------------
9361 function Valid_Tagged_Conversion
9362 (Target_Type : Entity_Id;
9363 Opnd_Type : Entity_Id) return Boolean
9366 -- Upward conversions are allowed (RM 4.6(22))
9368 if Covers (Target_Type, Opnd_Type)
9369 or else Is_Ancestor (Target_Type, Opnd_Type)
9373 -- Downward conversion are allowed if the operand is class-wide
9376 elsif Is_Class_Wide_Type (Opnd_Type)
9377 and then Covers (Opnd_Type, Target_Type)
9381 elsif Covers (Opnd_Type, Target_Type)
9382 or else Is_Ancestor (Opnd_Type, Target_Type)
9385 Conversion_Check (False,
9386 "downward conversion of tagged objects not allowed");
9388 -- Ada 2005 (AI-251): The conversion to/from interface types is
9391 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9394 -- If the operand is a class-wide type obtained through a limited_
9395 -- with clause, and the context includes the non-limited view, use
9396 -- it to determine whether the conversion is legal.
9398 elsif Is_Class_Wide_Type (Opnd_Type)
9399 and then From_With_Type (Opnd_Type)
9400 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9401 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9405 elsif Is_Access_Type (Opnd_Type)
9406 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9412 ("invalid tagged conversion, not compatible with}",
9413 N, First_Subtype (Opnd_Type));
9416 end Valid_Tagged_Conversion;
9418 -- Start of processing for Valid_Conversion
9421 Check_Parameterless_Call (Operand);
9423 if Is_Overloaded (Operand) then
9432 -- Remove procedure calls, which syntactically cannot appear in
9433 -- this context, but which cannot be removed by type checking,
9434 -- because the context does not impose a type.
9436 -- When compiling for VMS, spurious ambiguities can be produced
9437 -- when arithmetic operations have a literal operand and return
9438 -- System.Address or a descendant of it. These ambiguities are
9439 -- otherwise resolved by the context, but for conversions there
9440 -- is no context type and the removal of the spurious operations
9441 -- must be done explicitly here.
9443 -- The node may be labelled overloaded, but still contain only
9444 -- one interpretation because others were discarded in previous
9445 -- filters. If this is the case, retain the single interpretation
9448 Get_First_Interp (Operand, I, It);
9449 Opnd_Type := It.Typ;
9450 Get_Next_Interp (I, It);
9453 and then Opnd_Type /= Standard_Void_Type
9455 -- More than one candidate interpretation is available
9457 Get_First_Interp (Operand, I, It);
9458 while Present (It.Typ) loop
9459 if It.Typ = Standard_Void_Type then
9463 if Present (System_Aux_Id)
9464 and then Is_Descendent_Of_Address (It.Typ)
9469 Get_Next_Interp (I, It);
9473 Get_First_Interp (Operand, I, It);
9478 Error_Msg_N ("illegal operand in conversion", Operand);
9482 Get_Next_Interp (I, It);
9484 if Present (It.Typ) then
9486 It1 := Disambiguate (Operand, I1, I, Any_Type);
9488 if It1 = No_Interp then
9489 Error_Msg_N ("ambiguous operand in conversion", Operand);
9491 Error_Msg_Sloc := Sloc (It.Nam);
9492 Error_Msg_N -- CODEFIX
9493 ("\\possible interpretation#!", Operand);
9495 Error_Msg_Sloc := Sloc (N1);
9496 Error_Msg_N -- CODEFIX
9497 ("\\possible interpretation#!", Operand);
9503 Set_Etype (Operand, It1.Typ);
9504 Opnd_Type := It1.Typ;
9510 if Is_Numeric_Type (Target_Type) then
9512 -- A universal fixed expression can be converted to any numeric type
9514 if Opnd_Type = Universal_Fixed then
9517 -- Also no need to check when in an instance or inlined body, because
9518 -- the legality has been established when the template was analyzed.
9519 -- Furthermore, numeric conversions may occur where only a private
9520 -- view of the operand type is visible at the instantiation point.
9521 -- This results in a spurious error if we check that the operand type
9522 -- is a numeric type.
9524 -- Note: in a previous version of this unit, the following tests were
9525 -- applied only for generated code (Comes_From_Source set to False),
9526 -- but in fact the test is required for source code as well, since
9527 -- this situation can arise in source code.
9529 elsif In_Instance or else In_Inlined_Body then
9532 -- Otherwise we need the conversion check
9535 return Conversion_Check
9536 (Is_Numeric_Type (Opnd_Type),
9537 "illegal operand for numeric conversion");
9542 elsif Is_Array_Type (Target_Type) then
9543 if not Is_Array_Type (Opnd_Type)
9544 or else Opnd_Type = Any_Composite
9545 or else Opnd_Type = Any_String
9548 ("illegal operand for array conversion", Operand);
9551 return Valid_Array_Conversion;
9554 -- Ada 2005 (AI-251): Anonymous access types where target references an
9557 elsif (Ekind (Target_Type) = E_General_Access_Type
9559 Ekind (Target_Type) = E_Anonymous_Access_Type)
9560 and then Is_Interface (Directly_Designated_Type (Target_Type))
9562 -- Check the static accessibility rule of 4.6(17). Note that the
9563 -- check is not enforced when within an instance body, since the
9564 -- RM requires such cases to be caught at run time.
9566 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9567 if Type_Access_Level (Opnd_Type) >
9568 Type_Access_Level (Target_Type)
9570 -- In an instance, this is a run-time check, but one we know
9571 -- will fail, so generate an appropriate warning. The raise
9572 -- will be generated by Expand_N_Type_Conversion.
9574 if In_Instance_Body then
9576 ("?cannot convert local pointer to non-local access type",
9579 ("\?Program_Error will be raised at run time", Operand);
9582 ("cannot convert local pointer to non-local access type",
9587 -- Special accessibility checks are needed in the case of access
9588 -- discriminants declared for a limited type.
9590 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9591 and then not Is_Local_Anonymous_Access (Opnd_Type)
9593 -- When the operand is a selected access discriminant the check
9594 -- needs to be made against the level of the object denoted by
9595 -- the prefix of the selected name (Object_Access_Level handles
9596 -- checking the prefix of the operand for this case).
9598 if Nkind (Operand) = N_Selected_Component
9599 and then Object_Access_Level (Operand) >
9600 Type_Access_Level (Target_Type)
9602 -- In an instance, this is a run-time check, but one we know
9603 -- will fail, so generate an appropriate warning. The raise
9604 -- will be generated by Expand_N_Type_Conversion.
9606 if In_Instance_Body then
9608 ("?cannot convert access discriminant to non-local" &
9609 " access type", Operand);
9611 ("\?Program_Error will be raised at run time", Operand);
9614 ("cannot convert access discriminant to non-local" &
9615 " access type", Operand);
9620 -- The case of a reference to an access discriminant from
9621 -- within a limited type declaration (which will appear as
9622 -- a discriminal) is always illegal because the level of the
9623 -- discriminant is considered to be deeper than any (nameable)
9626 if Is_Entity_Name (Operand)
9627 and then not Is_Local_Anonymous_Access (Opnd_Type)
9628 and then (Ekind (Entity (Operand)) = E_In_Parameter
9629 or else Ekind (Entity (Operand)) = E_Constant)
9630 and then Present (Discriminal_Link (Entity (Operand)))
9633 ("discriminant has deeper accessibility level than target",
9642 -- General and anonymous access types
9644 elsif (Ekind (Target_Type) = E_General_Access_Type
9645 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9648 (Is_Access_Type (Opnd_Type)
9649 and then Ekind (Opnd_Type) /=
9650 E_Access_Subprogram_Type
9651 and then Ekind (Opnd_Type) /=
9652 E_Access_Protected_Subprogram_Type,
9653 "must be an access-to-object type")
9655 if Is_Access_Constant (Opnd_Type)
9656 and then not Is_Access_Constant (Target_Type)
9659 ("access-to-constant operand type not allowed", Operand);
9663 -- Check the static accessibility rule of 4.6(17). Note that the
9664 -- check is not enforced when within an instance body, since the RM
9665 -- requires such cases to be caught at run time.
9667 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9668 or else Is_Local_Anonymous_Access (Target_Type)
9670 if Type_Access_Level (Opnd_Type)
9671 > Type_Access_Level (Target_Type)
9673 -- In an instance, this is a run-time check, but one we know
9674 -- will fail, so generate an appropriate warning. The raise
9675 -- will be generated by Expand_N_Type_Conversion.
9677 if In_Instance_Body then
9679 ("?cannot convert local pointer to non-local access type",
9682 ("\?Program_Error will be raised at run time", Operand);
9685 -- Avoid generation of spurious error message
9687 if not Error_Posted (N) then
9689 ("cannot convert local pointer to non-local access type",
9696 -- Special accessibility checks are needed in the case of access
9697 -- discriminants declared for a limited type.
9699 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9700 and then not Is_Local_Anonymous_Access (Opnd_Type)
9703 -- When the operand is a selected access discriminant the check
9704 -- needs to be made against the level of the object denoted by
9705 -- the prefix of the selected name (Object_Access_Level handles
9706 -- checking the prefix of the operand for this case).
9708 if Nkind (Operand) = N_Selected_Component
9709 and then Object_Access_Level (Operand) >
9710 Type_Access_Level (Target_Type)
9712 -- In an instance, this is a run-time check, but one we know
9713 -- will fail, so generate an appropriate warning. The raise
9714 -- will be generated by Expand_N_Type_Conversion.
9716 if In_Instance_Body then
9718 ("?cannot convert access discriminant to non-local" &
9719 " access type", Operand);
9721 ("\?Program_Error will be raised at run time",
9726 ("cannot convert access discriminant to non-local" &
9727 " access type", Operand);
9732 -- The case of a reference to an access discriminant from
9733 -- within a limited type declaration (which will appear as
9734 -- a discriminal) is always illegal because the level of the
9735 -- discriminant is considered to be deeper than any (nameable)
9738 if Is_Entity_Name (Operand)
9739 and then (Ekind (Entity (Operand)) = E_In_Parameter
9740 or else Ekind (Entity (Operand)) = E_Constant)
9741 and then Present (Discriminal_Link (Entity (Operand)))
9744 ("discriminant has deeper accessibility level than target",
9751 -- In the presence of limited_with clauses we have to use non-limited
9752 -- views, if available.
9754 Check_Limited : declare
9755 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9756 -- Helper function to handle limited views
9758 --------------------------
9759 -- Full_Designated_Type --
9760 --------------------------
9762 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9763 Desig : constant Entity_Id := Designated_Type (T);
9766 -- Handle the limited view of a type
9768 if Is_Incomplete_Type (Desig)
9769 and then From_With_Type (Desig)
9770 and then Present (Non_Limited_View (Desig))
9772 return Available_View (Desig);
9776 end Full_Designated_Type;
9778 -- Local Declarations
9780 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9781 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9783 Same_Base : constant Boolean :=
9784 Base_Type (Target) = Base_Type (Opnd);
9786 -- Start of processing for Check_Limited
9789 if Is_Tagged_Type (Target) then
9790 return Valid_Tagged_Conversion (Target, Opnd);
9793 if not Same_Base then
9795 ("target designated type not compatible with }",
9796 N, Base_Type (Opnd));
9799 -- Ada 2005 AI-384: legality rule is symmetric in both
9800 -- designated types. The conversion is legal (with possible
9801 -- constraint check) if either designated type is
9804 elsif Subtypes_Statically_Match (Target, Opnd)
9806 (Has_Discriminants (Target)
9808 (not Is_Constrained (Opnd)
9809 or else not Is_Constrained (Target)))
9811 -- Special case, if Value_Size has been used to make the
9812 -- sizes different, the conversion is not allowed even
9813 -- though the subtypes statically match.
9815 if Known_Static_RM_Size (Target)
9816 and then Known_Static_RM_Size (Opnd)
9817 and then RM_Size (Target) /= RM_Size (Opnd)
9820 ("target designated subtype not compatible with }",
9823 ("\because sizes of the two designated subtypes differ",
9827 -- Normal case where conversion is allowed
9835 ("target designated subtype not compatible with }",
9842 -- Access to subprogram types. If the operand is an access parameter,
9843 -- the type has a deeper accessibility that any master, and cannot
9844 -- be assigned. We must make an exception if the conversion is part
9845 -- of an assignment and the target is the return object of an extended
9846 -- return statement, because in that case the accessibility check
9847 -- takes place after the return.
9849 elsif Is_Access_Subprogram_Type (Target_Type)
9850 and then No (Corresponding_Remote_Type (Opnd_Type))
9852 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9853 and then Is_Entity_Name (Operand)
9854 and then Ekind (Entity (Operand)) = E_In_Parameter
9856 (Nkind (Parent (N)) /= N_Assignment_Statement
9857 or else not Is_Entity_Name (Name (Parent (N)))
9858 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9861 ("illegal attempt to store anonymous access to subprogram",
9864 ("\value has deeper accessibility than any master " &
9869 ("\use named access type for& instead of access parameter",
9870 Operand, Entity (Operand));
9873 -- Check that the designated types are subtype conformant
9875 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9876 Old_Id => Designated_Type (Opnd_Type),
9879 -- Check the static accessibility rule of 4.6(20)
9881 if Type_Access_Level (Opnd_Type) >
9882 Type_Access_Level (Target_Type)
9885 ("operand type has deeper accessibility level than target",
9888 -- Check that if the operand type is declared in a generic body,
9889 -- then the target type must be declared within that same body
9890 -- (enforces last sentence of 4.6(20)).
9892 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9894 O_Gen : constant Node_Id :=
9895 Enclosing_Generic_Body (Opnd_Type);
9900 T_Gen := Enclosing_Generic_Body (Target_Type);
9901 while Present (T_Gen) and then T_Gen /= O_Gen loop
9902 T_Gen := Enclosing_Generic_Body (T_Gen);
9905 if T_Gen /= O_Gen then
9907 ("target type must be declared in same generic body"
9908 & " as operand type", N);
9915 -- Remote subprogram access types
9917 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9918 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9920 -- It is valid to convert from one RAS type to another provided
9921 -- that their specification statically match.
9923 Check_Subtype_Conformant
9925 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9927 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9932 -- If both are tagged types, check legality of view conversions
9934 elsif Is_Tagged_Type (Target_Type)
9935 and then Is_Tagged_Type (Opnd_Type)
9937 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9939 -- Types derived from the same root type are convertible
9941 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9944 -- In an instance or an inlined body, there may be inconsistent
9945 -- views of the same type, or of types derived from a common root.
9947 elsif (In_Instance or In_Inlined_Body)
9949 Root_Type (Underlying_Type (Target_Type)) =
9950 Root_Type (Underlying_Type (Opnd_Type))
9954 -- Special check for common access type error case
9956 elsif Ekind (Target_Type) = E_Access_Type
9957 and then Is_Access_Type (Opnd_Type)
9959 Error_Msg_N ("target type must be general access type!", N);
9960 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9964 Error_Msg_NE ("invalid conversion, not compatible with }",
9968 end Valid_Conversion;