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 -- Could use comments on what is going on here ???
1758 Get_First_Interp (Name (Arg), I, It);
1759 while Present (It.Nam) loop
1760 Error_Msg_Sloc := Sloc (It.Nam);
1762 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1763 Error_Msg_N ("interpretation (inherited) #!", Arg);
1765 Error_Msg_N ("interpretation #!", Arg);
1768 Get_Next_Interp (I, It);
1771 end Report_Ambiguous_Argument;
1773 -----------------------
1774 -- Resolution_Failed --
1775 -----------------------
1777 procedure Resolution_Failed is
1779 Patch_Up_Value (N, Typ);
1781 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1782 Set_Is_Overloaded (N, False);
1784 -- The caller will return without calling the expander, so we need
1785 -- to set the analyzed flag. Note that it is fine to set Analyzed
1786 -- to True even if we are in the middle of a shallow analysis,
1787 -- (see the spec of sem for more details) since this is an error
1788 -- situation anyway, and there is no point in repeating the
1789 -- analysis later (indeed it won't work to repeat it later, since
1790 -- we haven't got a clear resolution of which entity is being
1793 Set_Analyzed (N, True);
1795 end Resolution_Failed;
1797 -- Start of processing for Resolve
1804 -- Access attribute on remote subprogram cannot be used for
1805 -- a non-remote access-to-subprogram type.
1807 if Nkind (N) = N_Attribute_Reference
1808 and then (Attribute_Name (N) = Name_Access
1809 or else Attribute_Name (N) = Name_Unrestricted_Access
1810 or else Attribute_Name (N) = Name_Unchecked_Access)
1811 and then Comes_From_Source (N)
1812 and then Is_Entity_Name (Prefix (N))
1813 and then Is_Subprogram (Entity (Prefix (N)))
1814 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1815 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1818 ("prefix must statically denote a non-remote subprogram", N);
1821 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1823 -- If the context is a Remote_Access_To_Subprogram, access attributes
1824 -- must be resolved with the corresponding fat pointer. There is no need
1825 -- to check for the attribute name since the return type of an
1826 -- attribute is never a remote type.
1828 if Nkind (N) = N_Attribute_Reference
1829 and then Comes_From_Source (N)
1830 and then (Is_Remote_Call_Interface (Typ)
1831 or else Is_Remote_Types (Typ))
1834 Attr : constant Attribute_Id :=
1835 Get_Attribute_Id (Attribute_Name (N));
1836 Pref : constant Node_Id := Prefix (N);
1839 Is_Remote : Boolean := True;
1842 -- Check that Typ is a remote access-to-subprogram type
1844 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1845 -- Prefix (N) must statically denote a remote subprogram
1846 -- declared in a package specification.
1848 if Attr = Attribute_Access then
1849 Decl := Unit_Declaration_Node (Entity (Pref));
1851 if Nkind (Decl) = N_Subprogram_Body then
1852 Spec := Corresponding_Spec (Decl);
1854 if not No (Spec) then
1855 Decl := Unit_Declaration_Node (Spec);
1859 Spec := Parent (Decl);
1861 if not Is_Entity_Name (Prefix (N))
1862 or else Nkind (Spec) /= N_Package_Specification
1864 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1868 ("prefix must statically denote a remote subprogram ",
1873 -- If we are generating code for a distributed program.
1874 -- perform semantic checks against the corresponding
1877 if (Attr = Attribute_Access
1878 or else Attr = Attribute_Unchecked_Access
1879 or else Attr = Attribute_Unrestricted_Access)
1880 and then Expander_Active
1881 and then Get_PCS_Name /= Name_No_DSA
1883 Check_Subtype_Conformant
1884 (New_Id => Entity (Prefix (N)),
1885 Old_Id => Designated_Type
1886 (Corresponding_Remote_Type (Typ)),
1890 Process_Remote_AST_Attribute (N, Typ);
1897 Debug_A_Entry ("resolving ", N);
1899 if Comes_From_Source (N) then
1900 if Is_Fixed_Point_Type (Typ) then
1901 Check_Restriction (No_Fixed_Point, N);
1903 elsif Is_Floating_Point_Type (Typ)
1904 and then Typ /= Universal_Real
1905 and then Typ /= Any_Real
1907 Check_Restriction (No_Floating_Point, N);
1911 -- Return if already analyzed
1913 if Analyzed (N) then
1914 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1917 -- Return if type = Any_Type (previous error encountered)
1919 elsif Etype (N) = Any_Type then
1920 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1924 Check_Parameterless_Call (N);
1926 -- If not overloaded, then we know the type, and all that needs doing
1927 -- is to check that this type is compatible with the context.
1929 if not Is_Overloaded (N) then
1930 Found := Covers (Typ, Etype (N));
1931 Expr_Type := Etype (N);
1933 -- In the overloaded case, we must select the interpretation that
1934 -- is compatible with the context (i.e. the type passed to Resolve)
1937 -- Loop through possible interpretations
1939 Get_First_Interp (N, I, It);
1940 Interp_Loop : while Present (It.Typ) loop
1942 -- We are only interested in interpretations that are compatible
1943 -- with the expected type, any other interpretations are ignored.
1945 if not Covers (Typ, It.Typ) then
1946 if Debug_Flag_V then
1947 Write_Str (" interpretation incompatible with context");
1952 -- Skip the current interpretation if it is disabled by an
1953 -- abstract operator. This action is performed only when the
1954 -- type against which we are resolving is the same as the
1955 -- type of the interpretation.
1957 if Ada_Version >= Ada_05
1958 and then It.Typ = Typ
1959 and then Typ /= Universal_Integer
1960 and then Typ /= Universal_Real
1961 and then Present (It.Abstract_Op)
1966 -- First matching interpretation
1972 Expr_Type := It.Typ;
1974 -- Matching interpretation that is not the first, maybe an
1975 -- error, but there are some cases where preference rules are
1976 -- used to choose between the two possibilities. These and
1977 -- some more obscure cases are handled in Disambiguate.
1980 -- If the current statement is part of a predefined library
1981 -- unit, then all interpretations which come from user level
1982 -- packages should not be considered.
1985 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1990 Error_Msg_Sloc := Sloc (Seen);
1991 It1 := Disambiguate (N, I1, I, Typ);
1993 -- Disambiguation has succeeded. Skip the remaining
1996 if It1 /= No_Interp then
1998 Expr_Type := It1.Typ;
2000 while Present (It.Typ) loop
2001 Get_Next_Interp (I, It);
2005 -- Before we issue an ambiguity complaint, check for
2006 -- the case of a subprogram call where at least one
2007 -- of the arguments is Any_Type, and if so, suppress
2008 -- the message, since it is a cascaded error.
2010 if Nkind_In (N, N_Function_Call,
2011 N_Procedure_Call_Statement)
2018 A := First_Actual (N);
2019 while Present (A) loop
2022 if Nkind (E) = N_Parameter_Association then
2023 E := Explicit_Actual_Parameter (E);
2026 if Etype (E) = Any_Type then
2027 if Debug_Flag_V then
2028 Write_Str ("Any_Type in call");
2039 elsif Nkind (N) in N_Binary_Op
2040 and then (Etype (Left_Opnd (N)) = Any_Type
2041 or else Etype (Right_Opnd (N)) = Any_Type)
2045 elsif Nkind (N) in N_Unary_Op
2046 and then Etype (Right_Opnd (N)) = Any_Type
2051 -- Not that special case, so issue message using the
2052 -- flag Ambiguous to control printing of the header
2053 -- message only at the start of an ambiguous set.
2055 if not Ambiguous then
2056 if Nkind (N) = N_Function_Call
2057 and then Nkind (Name (N)) = N_Explicit_Dereference
2060 ("ambiguous expression "
2061 & "(cannot resolve indirect call)!", N);
2063 Error_Msg_NE -- CODEFIX
2064 ("ambiguous expression (cannot resolve&)!",
2070 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2072 ("\\possible interpretation (inherited)#!", N);
2074 Error_Msg_N -- CODEFIX
2075 ("\\possible interpretation#!", N);
2079 (N, N_Procedure_Call_Statement, N_Function_Call)
2080 and then Present (Parameter_Associations (N))
2082 Report_Ambiguous_Argument;
2086 Error_Msg_Sloc := Sloc (It.Nam);
2088 -- By default, the error message refers to the candidate
2089 -- interpretation. But if it is a predefined operator, it
2090 -- is implicitly declared at the declaration of the type
2091 -- of the operand. Recover the sloc of that declaration
2092 -- for the error message.
2094 if Nkind (N) in N_Op
2095 and then Scope (It.Nam) = Standard_Standard
2096 and then not Is_Overloaded (Right_Opnd (N))
2097 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2100 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2102 if Comes_From_Source (Err_Type)
2103 and then Present (Parent (Err_Type))
2105 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2108 elsif Nkind (N) in N_Binary_Op
2109 and then Scope (It.Nam) = Standard_Standard
2110 and then not Is_Overloaded (Left_Opnd (N))
2111 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2114 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2116 if Comes_From_Source (Err_Type)
2117 and then Present (Parent (Err_Type))
2119 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2122 -- If this is an indirect call, use the subprogram_type
2123 -- in the message, to have a meaningful location.
2124 -- Indicate as well if this is an inherited operation,
2125 -- created by a type declaration.
2127 elsif Nkind (N) = N_Function_Call
2128 and then Nkind (Name (N)) = N_Explicit_Dereference
2129 and then Is_Type (It.Nam)
2133 Sloc (Associated_Node_For_Itype (Err_Type));
2138 if Nkind (N) in N_Op
2139 and then Scope (It.Nam) = Standard_Standard
2140 and then Present (Err_Type)
2142 -- Special-case the message for universal_fixed
2143 -- operators, which are not declared with the type
2144 -- of the operand, but appear forever in Standard.
2146 if It.Typ = Universal_Fixed
2147 and then Scope (It.Nam) = Standard_Standard
2150 ("\\possible interpretation as " &
2151 "universal_fixed operation " &
2152 "(RM 4.5.5 (19))", N);
2155 ("\\possible interpretation (predefined)#!", N);
2159 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2162 ("\\possible interpretation (inherited)#!", N);
2164 Error_Msg_N -- CODEFIX
2165 ("\\possible interpretation#!", N);
2171 -- We have a matching interpretation, Expr_Type is the type
2172 -- from this interpretation, and Seen is the entity.
2174 -- For an operator, just set the entity name. The type will be
2175 -- set by the specific operator resolution routine.
2177 if Nkind (N) in N_Op then
2178 Set_Entity (N, Seen);
2179 Generate_Reference (Seen, N);
2181 elsif Nkind (N) = N_Character_Literal then
2182 Set_Etype (N, Expr_Type);
2184 elsif Nkind (N) = N_Conditional_Expression then
2185 Set_Etype (N, Expr_Type);
2187 -- For an explicit dereference, attribute reference, range,
2188 -- short-circuit form (which is not an operator node), or call
2189 -- with a name that is an explicit dereference, there is
2190 -- nothing to be done at this point.
2192 elsif Nkind_In (N, N_Explicit_Dereference,
2193 N_Attribute_Reference,
2195 N_Indexed_Component,
2198 N_Selected_Component,
2200 or else Nkind (Name (N)) = N_Explicit_Dereference
2204 -- For procedure or function calls, set the type of the name,
2205 -- and also the entity pointer for the prefix
2207 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2208 and then (Is_Entity_Name (Name (N))
2209 or else Nkind (Name (N)) = N_Operator_Symbol)
2211 Set_Etype (Name (N), Expr_Type);
2212 Set_Entity (Name (N), Seen);
2213 Generate_Reference (Seen, Name (N));
2215 elsif Nkind (N) = N_Function_Call
2216 and then Nkind (Name (N)) = N_Selected_Component
2218 Set_Etype (Name (N), Expr_Type);
2219 Set_Entity (Selector_Name (Name (N)), Seen);
2220 Generate_Reference (Seen, Selector_Name (Name (N)));
2222 -- For all other cases, just set the type of the Name
2225 Set_Etype (Name (N), Expr_Type);
2232 -- Move to next interpretation
2234 exit Interp_Loop when No (It.Typ);
2236 Get_Next_Interp (I, It);
2237 end loop Interp_Loop;
2240 -- At this stage Found indicates whether or not an acceptable
2241 -- interpretation exists. If not, then we have an error, except
2242 -- that if the context is Any_Type as a result of some other error,
2243 -- then we suppress the error report.
2246 if Typ /= Any_Type then
2248 -- If type we are looking for is Void, then this is the procedure
2249 -- call case, and the error is simply that what we gave is not a
2250 -- procedure name (we think of procedure calls as expressions with
2251 -- types internally, but the user doesn't think of them this way!)
2253 if Typ = Standard_Void_Type then
2255 -- Special case message if function used as a procedure
2257 if Nkind (N) = N_Procedure_Call_Statement
2258 and then Is_Entity_Name (Name (N))
2259 and then Ekind (Entity (Name (N))) = E_Function
2262 ("cannot use function & in a procedure call",
2263 Name (N), Entity (Name (N)));
2265 -- Otherwise give general message (not clear what cases this
2266 -- covers, but no harm in providing for them!)
2269 Error_Msg_N ("expect procedure name in procedure call", N);
2274 -- Otherwise we do have a subexpression with the wrong type
2276 -- Check for the case of an allocator which uses an access type
2277 -- instead of the designated type. This is a common error and we
2278 -- specialize the message, posting an error on the operand of the
2279 -- allocator, complaining that we expected the designated type of
2282 elsif Nkind (N) = N_Allocator
2283 and then Ekind (Typ) in Access_Kind
2284 and then Ekind (Etype (N)) in Access_Kind
2285 and then Designated_Type (Etype (N)) = Typ
2287 Wrong_Type (Expression (N), Designated_Type (Typ));
2290 -- Check for view mismatch on Null in instances, for which the
2291 -- view-swapping mechanism has no identifier.
2293 elsif (In_Instance or else In_Inlined_Body)
2294 and then (Nkind (N) = N_Null)
2295 and then Is_Private_Type (Typ)
2296 and then Is_Access_Type (Full_View (Typ))
2298 Resolve (N, Full_View (Typ));
2302 -- Check for an aggregate. Sometimes we can get bogus aggregates
2303 -- from misuse of parentheses, and we are about to complain about
2304 -- the aggregate without even looking inside it.
2306 -- Instead, if we have an aggregate of type Any_Composite, then
2307 -- analyze and resolve the component fields, and then only issue
2308 -- another message if we get no errors doing this (otherwise
2309 -- assume that the errors in the aggregate caused the problem).
2311 elsif Nkind (N) = N_Aggregate
2312 and then Etype (N) = Any_Composite
2314 -- Disable expansion in any case. If there is a type mismatch
2315 -- it may be fatal to try to expand the aggregate. The flag
2316 -- would otherwise be set to false when the error is posted.
2318 Expander_Active := False;
2321 procedure Check_Aggr (Aggr : Node_Id);
2322 -- Check one aggregate, and set Found to True if we have a
2323 -- definite error in any of its elements
2325 procedure Check_Elmt (Aelmt : Node_Id);
2326 -- Check one element of aggregate and set Found to True if
2327 -- we definitely have an error in the element.
2333 procedure Check_Aggr (Aggr : Node_Id) is
2337 if Present (Expressions (Aggr)) then
2338 Elmt := First (Expressions (Aggr));
2339 while Present (Elmt) loop
2345 if Present (Component_Associations (Aggr)) then
2346 Elmt := First (Component_Associations (Aggr));
2347 while Present (Elmt) loop
2349 -- If this is a default-initialized component, then
2350 -- there is nothing to check. The box will be
2351 -- replaced by the appropriate call during late
2354 if not Box_Present (Elmt) then
2355 Check_Elmt (Expression (Elmt));
2367 procedure Check_Elmt (Aelmt : Node_Id) is
2369 -- If we have a nested aggregate, go inside it (to
2370 -- attempt a naked analyze-resolve of the aggregate
2371 -- can cause undesirable cascaded errors). Do not
2372 -- resolve expression if it needs a type from context,
2373 -- as for integer * fixed expression.
2375 if Nkind (Aelmt) = N_Aggregate then
2381 if not Is_Overloaded (Aelmt)
2382 and then Etype (Aelmt) /= Any_Fixed
2387 if Etype (Aelmt) = Any_Type then
2398 -- If an error message was issued already, Found got reset
2399 -- to True, so if it is still False, issue the standard
2400 -- Wrong_Type message.
2403 if Is_Overloaded (N)
2404 and then Nkind (N) = N_Function_Call
2407 Subp_Name : Node_Id;
2409 if Is_Entity_Name (Name (N)) then
2410 Subp_Name := Name (N);
2412 elsif Nkind (Name (N)) = N_Selected_Component then
2414 -- Protected operation: retrieve operation name
2416 Subp_Name := Selector_Name (Name (N));
2418 raise Program_Error;
2421 Error_Msg_Node_2 := Typ;
2422 Error_Msg_NE ("no visible interpretation of&" &
2423 " matches expected type&", N, Subp_Name);
2426 if All_Errors_Mode then
2428 Index : Interp_Index;
2432 Error_Msg_N ("\\possible interpretations:", N);
2434 Get_First_Interp (Name (N), Index, It);
2435 while Present (It.Nam) loop
2436 Error_Msg_Sloc := Sloc (It.Nam);
2437 Error_Msg_Node_2 := It.Nam;
2439 ("\\ type& for & declared#", N, It.Typ);
2440 Get_Next_Interp (Index, It);
2445 Error_Msg_N ("\use -gnatf for details", N);
2448 Wrong_Type (N, Typ);
2456 -- Test if we have more than one interpretation for the context
2458 elsif Ambiguous then
2462 -- Here we have an acceptable interpretation for the context
2465 -- Propagate type information and normalize tree for various
2466 -- predefined operations. If the context only imposes a class of
2467 -- types, rather than a specific type, propagate the actual type
2470 if Typ = Any_Integer
2471 or else Typ = Any_Boolean
2472 or else Typ = Any_Modular
2473 or else Typ = Any_Real
2474 or else Typ = Any_Discrete
2476 Ctx_Type := Expr_Type;
2478 -- Any_Fixed is legal in a real context only if a specific
2479 -- fixed point type is imposed. If Norman Cohen can be
2480 -- confused by this, it deserves a separate message.
2483 and then Expr_Type = Any_Fixed
2485 Error_Msg_N ("illegal context for mixed mode operation", N);
2486 Set_Etype (N, Universal_Real);
2487 Ctx_Type := Universal_Real;
2491 -- A user-defined operator is transformed into a function call at
2492 -- this point, so that further processing knows that operators are
2493 -- really operators (i.e. are predefined operators). User-defined
2494 -- operators that are intrinsic are just renamings of the predefined
2495 -- ones, and need not be turned into calls either, but if they rename
2496 -- a different operator, we must transform the node accordingly.
2497 -- Instantiations of Unchecked_Conversion are intrinsic but are
2498 -- treated as functions, even if given an operator designator.
2500 if Nkind (N) in N_Op
2501 and then Present (Entity (N))
2502 and then Ekind (Entity (N)) /= E_Operator
2505 if not Is_Predefined_Op (Entity (N)) then
2506 Rewrite_Operator_As_Call (N, Entity (N));
2508 elsif Present (Alias (Entity (N)))
2510 Nkind (Parent (Parent (Entity (N)))) =
2511 N_Subprogram_Renaming_Declaration
2513 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2515 -- If the node is rewritten, it will be fully resolved in
2516 -- Rewrite_Renamed_Operator.
2518 if Analyzed (N) then
2524 case N_Subexpr'(Nkind (N)) is
2526 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2528 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2530 when N_Short_Circuit
2531 => Resolve_Short_Circuit (N, Ctx_Type);
2533 when N_Attribute_Reference
2534 => Resolve_Attribute (N, Ctx_Type);
2536 when N_Character_Literal
2537 => Resolve_Character_Literal (N, Ctx_Type);
2539 when N_Conditional_Expression
2540 => Resolve_Conditional_Expression (N, Ctx_Type);
2542 when N_Expanded_Name
2543 => Resolve_Entity_Name (N, Ctx_Type);
2545 when N_Extension_Aggregate
2546 => Resolve_Extension_Aggregate (N, Ctx_Type);
2548 when N_Explicit_Dereference
2549 => Resolve_Explicit_Dereference (N, Ctx_Type);
2551 when N_Function_Call
2552 => Resolve_Call (N, Ctx_Type);
2555 => Resolve_Entity_Name (N, Ctx_Type);
2557 when N_Indexed_Component
2558 => Resolve_Indexed_Component (N, Ctx_Type);
2560 when N_Integer_Literal
2561 => Resolve_Integer_Literal (N, Ctx_Type);
2563 when N_Membership_Test
2564 => Resolve_Membership_Op (N, Ctx_Type);
2566 when N_Null => Resolve_Null (N, Ctx_Type);
2568 when N_Op_And | N_Op_Or | N_Op_Xor
2569 => Resolve_Logical_Op (N, Ctx_Type);
2571 when N_Op_Eq | N_Op_Ne
2572 => Resolve_Equality_Op (N, Ctx_Type);
2574 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2575 => Resolve_Comparison_Op (N, Ctx_Type);
2577 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2579 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2580 N_Op_Divide | N_Op_Mod | N_Op_Rem
2582 => Resolve_Arithmetic_Op (N, Ctx_Type);
2584 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2586 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2588 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2589 => Resolve_Unary_Op (N, Ctx_Type);
2591 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2593 when N_Procedure_Call_Statement
2594 => Resolve_Call (N, Ctx_Type);
2596 when N_Operator_Symbol
2597 => Resolve_Operator_Symbol (N, Ctx_Type);
2599 when N_Qualified_Expression
2600 => Resolve_Qualified_Expression (N, Ctx_Type);
2602 when N_Raise_xxx_Error
2603 => Set_Etype (N, Ctx_Type);
2605 when N_Range => Resolve_Range (N, Ctx_Type);
2608 => Resolve_Real_Literal (N, Ctx_Type);
2610 when N_Reference => Resolve_Reference (N, Ctx_Type);
2612 when N_Selected_Component
2613 => Resolve_Selected_Component (N, Ctx_Type);
2615 when N_Slice => Resolve_Slice (N, Ctx_Type);
2617 when N_String_Literal
2618 => Resolve_String_Literal (N, Ctx_Type);
2620 when N_Subprogram_Info
2621 => Resolve_Subprogram_Info (N, Ctx_Type);
2623 when N_Type_Conversion
2624 => Resolve_Type_Conversion (N, Ctx_Type);
2626 when N_Unchecked_Expression =>
2627 Resolve_Unchecked_Expression (N, Ctx_Type);
2629 when N_Unchecked_Type_Conversion =>
2630 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2634 -- If the subexpression was replaced by a non-subexpression, then
2635 -- all we do is to expand it. The only legitimate case we know of
2636 -- is converting procedure call statement to entry call statements,
2637 -- but there may be others, so we are making this test general.
2639 if Nkind (N) not in N_Subexpr then
2640 Debug_A_Exit ("resolving ", N, " (done)");
2645 -- The expression is definitely NOT overloaded at this point, so
2646 -- we reset the Is_Overloaded flag to avoid any confusion when
2647 -- reanalyzing the node.
2649 Set_Is_Overloaded (N, False);
2651 -- Freeze expression type, entity if it is a name, and designated
2652 -- type if it is an allocator (RM 13.14(10,11,13)).
2654 -- Now that the resolution of the type of the node is complete,
2655 -- and we did not detect an error, we can expand this node. We
2656 -- skip the expand call if we are in a default expression, see
2657 -- section "Handling of Default Expressions" in Sem spec.
2659 Debug_A_Exit ("resolving ", N, " (done)");
2661 -- We unconditionally freeze the expression, even if we are in
2662 -- default expression mode (the Freeze_Expression routine tests
2663 -- this flag and only freezes static types if it is set).
2665 Freeze_Expression (N);
2667 -- Now we can do the expansion
2677 -- Version with check(s) suppressed
2679 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2681 if Suppress = All_Checks then
2683 Svg : constant Suppress_Array := Scope_Suppress;
2685 Scope_Suppress := (others => True);
2687 Scope_Suppress := Svg;
2692 Svg : constant Boolean := Scope_Suppress (Suppress);
2694 Scope_Suppress (Suppress) := True;
2696 Scope_Suppress (Suppress) := Svg;
2705 -- Version with implicit type
2707 procedure Resolve (N : Node_Id) is
2709 Resolve (N, Etype (N));
2712 ---------------------
2713 -- Resolve_Actuals --
2714 ---------------------
2716 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2717 Loc : constant Source_Ptr := Sloc (N);
2722 Prev : Node_Id := Empty;
2725 procedure Check_Argument_Order;
2726 -- Performs a check for the case where the actuals are all simple
2727 -- identifiers that correspond to the formal names, but in the wrong
2728 -- order, which is considered suspicious and cause for a warning.
2730 procedure Check_Prefixed_Call;
2731 -- If the original node is an overloaded call in prefix notation,
2732 -- insert an 'Access or a dereference as needed over the first actual.
2733 -- Try_Object_Operation has already verified that there is a valid
2734 -- interpretation, but the form of the actual can only be determined
2735 -- once the primitive operation is identified.
2737 procedure Insert_Default;
2738 -- If the actual is missing in a call, insert in the actuals list
2739 -- an instance of the default expression. The insertion is always
2740 -- a named association.
2742 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2743 -- Check whether T1 and T2, or their full views, are derived from a
2744 -- common type. Used to enforce the restrictions on array conversions
2747 function Static_Concatenation (N : Node_Id) return Boolean;
2748 -- Predicate to determine whether an actual that is a concatenation
2749 -- will be evaluated statically and does not need a transient scope.
2750 -- This must be determined before the actual is resolved and expanded
2751 -- because if needed the transient scope must be introduced earlier.
2753 --------------------------
2754 -- Check_Argument_Order --
2755 --------------------------
2757 procedure Check_Argument_Order is
2759 -- Nothing to do if no parameters, or original node is neither a
2760 -- function call nor a procedure call statement (happens in the
2761 -- operator-transformed-to-function call case), or the call does
2762 -- not come from source, or this warning is off.
2764 if not Warn_On_Parameter_Order
2766 No (Parameter_Associations (N))
2768 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2771 not Comes_From_Source (N)
2777 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2780 -- Nothing to do if only one parameter
2786 -- Here if at least two arguments
2789 Actuals : array (1 .. Nargs) of Node_Id;
2793 Wrong_Order : Boolean := False;
2794 -- Set True if an out of order case is found
2797 -- Collect identifier names of actuals, fail if any actual is
2798 -- not a simple identifier, and record max length of name.
2800 Actual := First (Parameter_Associations (N));
2801 for J in Actuals'Range loop
2802 if Nkind (Actual) /= N_Identifier then
2805 Actuals (J) := Actual;
2810 -- If we got this far, all actuals are identifiers and the list
2811 -- of their names is stored in the Actuals array.
2813 Formal := First_Formal (Nam);
2814 for J in Actuals'Range loop
2816 -- If we ran out of formals, that's odd, probably an error
2817 -- which will be detected elsewhere, but abandon the search.
2823 -- If name matches and is in order OK
2825 if Chars (Formal) = Chars (Actuals (J)) then
2829 -- If no match, see if it is elsewhere in list and if so
2830 -- flag potential wrong order if type is compatible.
2832 for K in Actuals'Range loop
2833 if Chars (Formal) = Chars (Actuals (K))
2835 Has_Compatible_Type (Actuals (K), Etype (Formal))
2837 Wrong_Order := True;
2847 <<Continue>> Next_Formal (Formal);
2850 -- If Formals left over, also probably an error, skip warning
2852 if Present (Formal) then
2856 -- Here we give the warning if something was out of order
2860 ("actuals for this call may be in wrong order?", N);
2864 end Check_Argument_Order;
2866 -------------------------
2867 -- Check_Prefixed_Call --
2868 -------------------------
2870 procedure Check_Prefixed_Call is
2871 Act : constant Node_Id := First_Actual (N);
2872 A_Type : constant Entity_Id := Etype (Act);
2873 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2874 Orig : constant Node_Id := Original_Node (N);
2878 -- Check whether the call is a prefixed call, with or without
2879 -- additional actuals.
2881 if Nkind (Orig) = N_Selected_Component
2883 (Nkind (Orig) = N_Indexed_Component
2884 and then Nkind (Prefix (Orig)) = N_Selected_Component
2885 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2886 and then Is_Entity_Name (Act)
2887 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2889 if Is_Access_Type (A_Type)
2890 and then not Is_Access_Type (F_Type)
2892 -- Introduce dereference on object in prefix
2895 Make_Explicit_Dereference (Sloc (Act),
2896 Prefix => Relocate_Node (Act));
2897 Rewrite (Act, New_A);
2900 elsif Is_Access_Type (F_Type)
2901 and then not Is_Access_Type (A_Type)
2903 -- Introduce an implicit 'Access in prefix
2905 if not Is_Aliased_View (Act) then
2907 ("object in prefixed call to& must be aliased"
2908 & " (RM-2005 4.3.1 (13))",
2913 Make_Attribute_Reference (Loc,
2914 Attribute_Name => Name_Access,
2915 Prefix => Relocate_Node (Act)));
2920 end Check_Prefixed_Call;
2922 --------------------
2923 -- Insert_Default --
2924 --------------------
2926 procedure Insert_Default is
2931 -- Missing argument in call, nothing to insert
2933 if No (Default_Value (F)) then
2937 -- Note that we do a full New_Copy_Tree, so that any associated
2938 -- Itypes are properly copied. This may not be needed any more,
2939 -- but it does no harm as a safety measure! Defaults of a generic
2940 -- formal may be out of bounds of the corresponding actual (see
2941 -- cc1311b) and an additional check may be required.
2946 New_Scope => Current_Scope,
2949 if Is_Concurrent_Type (Scope (Nam))
2950 and then Has_Discriminants (Scope (Nam))
2952 Replace_Actual_Discriminants (N, Actval);
2955 if Is_Overloadable (Nam)
2956 and then Present (Alias (Nam))
2958 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2959 and then not Is_Tagged_Type (Etype (F))
2961 -- If default is a real literal, do not introduce a
2962 -- conversion whose effect may depend on the run-time
2963 -- size of universal real.
2965 if Nkind (Actval) = N_Real_Literal then
2966 Set_Etype (Actval, Base_Type (Etype (F)));
2968 Actval := Unchecked_Convert_To (Etype (F), Actval);
2972 if Is_Scalar_Type (Etype (F)) then
2973 Enable_Range_Check (Actval);
2976 Set_Parent (Actval, N);
2978 -- Resolve aggregates with their base type, to avoid scope
2979 -- anomalies: the subtype was first built in the subprogram
2980 -- declaration, and the current call may be nested.
2982 if Nkind (Actval) = N_Aggregate then
2983 Analyze_And_Resolve (Actval, Etype (F));
2985 Analyze_And_Resolve (Actval, Etype (Actval));
2989 Set_Parent (Actval, N);
2991 -- See note above concerning aggregates
2993 if Nkind (Actval) = N_Aggregate
2994 and then Has_Discriminants (Etype (Actval))
2996 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2998 -- Resolve entities with their own type, which may differ
2999 -- from the type of a reference in a generic context (the
3000 -- view swapping mechanism did not anticipate the re-analysis
3001 -- of default values in calls).
3003 elsif Is_Entity_Name (Actval) then
3004 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3007 Analyze_And_Resolve (Actval, Etype (Actval));
3011 -- If default is a tag indeterminate function call, propagate
3012 -- tag to obtain proper dispatching.
3014 if Is_Controlling_Formal (F)
3015 and then Nkind (Default_Value (F)) = N_Function_Call
3017 Set_Is_Controlling_Actual (Actval);
3022 -- If the default expression raises constraint error, then just
3023 -- silently replace it with an N_Raise_Constraint_Error node,
3024 -- since we already gave the warning on the subprogram spec.
3026 if Raises_Constraint_Error (Actval) then
3028 Make_Raise_Constraint_Error (Loc,
3029 Reason => CE_Range_Check_Failed));
3030 Set_Raises_Constraint_Error (Actval);
3031 Set_Etype (Actval, Etype (F));
3035 Make_Parameter_Association (Loc,
3036 Explicit_Actual_Parameter => Actval,
3037 Selector_Name => Make_Identifier (Loc, Chars (F)));
3039 -- Case of insertion is first named actual
3041 if No (Prev) or else
3042 Nkind (Parent (Prev)) /= N_Parameter_Association
3044 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3045 Set_First_Named_Actual (N, Actval);
3048 if No (Parameter_Associations (N)) then
3049 Set_Parameter_Associations (N, New_List (Assoc));
3051 Append (Assoc, Parameter_Associations (N));
3055 Insert_After (Prev, Assoc);
3058 -- Case of insertion is not first named actual
3061 Set_Next_Named_Actual
3062 (Assoc, Next_Named_Actual (Parent (Prev)));
3063 Set_Next_Named_Actual (Parent (Prev), Actval);
3064 Append (Assoc, Parameter_Associations (N));
3067 Mark_Rewrite_Insertion (Assoc);
3068 Mark_Rewrite_Insertion (Actval);
3077 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3078 FT1 : Entity_Id := T1;
3079 FT2 : Entity_Id := T2;
3082 if Is_Private_Type (T1)
3083 and then Present (Full_View (T1))
3085 FT1 := Full_View (T1);
3088 if Is_Private_Type (T2)
3089 and then Present (Full_View (T2))
3091 FT2 := Full_View (T2);
3094 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3097 --------------------------
3098 -- Static_Concatenation --
3099 --------------------------
3101 function Static_Concatenation (N : Node_Id) return Boolean is
3104 when N_String_Literal =>
3109 -- Concatenation is static when both operands are static
3110 -- and the concatenation operator is a predefined one.
3112 return Scope (Entity (N)) = Standard_Standard
3114 Static_Concatenation (Left_Opnd (N))
3116 Static_Concatenation (Right_Opnd (N));
3119 if Is_Entity_Name (N) then
3121 Ent : constant Entity_Id := Entity (N);
3123 return Ekind (Ent) = E_Constant
3124 and then Present (Constant_Value (Ent))
3126 Is_Static_Expression (Constant_Value (Ent));
3133 end Static_Concatenation;
3135 -- Start of processing for Resolve_Actuals
3138 Check_Argument_Order;
3140 if Present (First_Actual (N)) then
3141 Check_Prefixed_Call;
3144 A := First_Actual (N);
3145 F := First_Formal (Nam);
3146 while Present (F) loop
3147 if No (A) and then Needs_No_Actuals (Nam) then
3150 -- If we have an error in any actual or formal, indicated by a type
3151 -- of Any_Type, then abandon resolution attempt, and set result type
3154 elsif (Present (A) and then Etype (A) = Any_Type)
3155 or else Etype (F) = Any_Type
3157 Set_Etype (N, Any_Type);
3161 -- Case where actual is present
3163 -- If the actual is an entity, generate a reference to it now. We
3164 -- do this before the actual is resolved, because a formal of some
3165 -- protected subprogram, or a task discriminant, will be rewritten
3166 -- during expansion, and the reference to the source entity may
3170 and then Is_Entity_Name (A)
3171 and then Comes_From_Source (N)
3173 Orig_A := Entity (A);
3175 if Present (Orig_A) then
3176 if Is_Formal (Orig_A)
3177 and then Ekind (F) /= E_In_Parameter
3179 Generate_Reference (Orig_A, A, 'm');
3180 elsif not Is_Overloaded (A) then
3181 Generate_Reference (Orig_A, A);
3187 and then (Nkind (Parent (A)) /= N_Parameter_Association
3189 Chars (Selector_Name (Parent (A))) = Chars (F))
3191 -- If style checking mode on, check match of formal name
3194 if Nkind (Parent (A)) = N_Parameter_Association then
3195 Check_Identifier (Selector_Name (Parent (A)), F);
3199 -- If the formal is Out or In_Out, do not resolve and expand the
3200 -- conversion, because it is subsequently expanded into explicit
3201 -- temporaries and assignments. However, the object of the
3202 -- conversion can be resolved. An exception is the case of tagged
3203 -- type conversion with a class-wide actual. In that case we want
3204 -- the tag check to occur and no temporary will be needed (no
3205 -- representation change can occur) and the parameter is passed by
3206 -- reference, so we go ahead and resolve the type conversion.
3207 -- Another exception is the case of reference to component or
3208 -- subcomponent of a bit-packed array, in which case we want to
3209 -- defer expansion to the point the in and out assignments are
3212 if Ekind (F) /= E_In_Parameter
3213 and then Nkind (A) = N_Type_Conversion
3214 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3216 if Ekind (F) = E_In_Out_Parameter
3217 and then Is_Array_Type (Etype (F))
3219 if Has_Aliased_Components (Etype (Expression (A)))
3220 /= Has_Aliased_Components (Etype (F))
3223 -- In a view conversion, the conversion must be legal in
3224 -- both directions, and thus both component types must be
3225 -- aliased, or neither (4.6 (8)).
3227 -- The additional rule 4.6 (24.9.2) seems unduly
3228 -- restrictive: the privacy requirement should not apply
3229 -- to generic types, and should be checked in an
3230 -- instance. ARG query is in order ???
3233 ("both component types in a view conversion must be"
3234 & " aliased, or neither", A);
3237 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3239 if Is_By_Reference_Type (Etype (F))
3240 or else Is_By_Reference_Type (Etype (Expression (A)))
3243 ("view conversion between unrelated by reference " &
3244 "array types not allowed (\'A'I-00246)", A);
3247 Comp_Type : constant Entity_Id :=
3249 (Etype (Expression (A)));
3251 if Comes_From_Source (A)
3252 and then Ada_Version >= Ada_05
3254 ((Is_Private_Type (Comp_Type)
3255 and then not Is_Generic_Type (Comp_Type))
3256 or else Is_Tagged_Type (Comp_Type)
3257 or else Is_Volatile (Comp_Type))
3260 ("component type of a view conversion cannot"
3261 & " be private, tagged, or volatile"
3270 if (Conversion_OK (A)
3271 or else Valid_Conversion (A, Etype (A), Expression (A)))
3272 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3274 Resolve (Expression (A));
3277 -- If the actual is a function call that returns a limited
3278 -- unconstrained object that needs finalization, create a
3279 -- transient scope for it, so that it can receive the proper
3280 -- finalization list.
3282 elsif Nkind (A) = N_Function_Call
3283 and then Is_Limited_Record (Etype (F))
3284 and then not Is_Constrained (Etype (F))
3285 and then Expander_Active
3287 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3289 Establish_Transient_Scope (A, False);
3291 -- A small optimization: if one of the actuals is a concatenation
3292 -- create a block around a procedure call to recover stack space.
3293 -- This alleviates stack usage when several procedure calls in
3294 -- the same statement list use concatenation. We do not perform
3295 -- this wrapping for code statements, where the argument is a
3296 -- static string, and we want to preserve warnings involving
3297 -- sequences of such statements.
3299 elsif Nkind (A) = N_Op_Concat
3300 and then Nkind (N) = N_Procedure_Call_Statement
3301 and then Expander_Active
3303 not (Is_Intrinsic_Subprogram (Nam)
3304 and then Chars (Nam) = Name_Asm)
3305 and then not Static_Concatenation (A)
3307 Establish_Transient_Scope (A, False);
3308 Resolve (A, Etype (F));
3311 if Nkind (A) = N_Type_Conversion
3312 and then Is_Array_Type (Etype (F))
3313 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3315 (Is_Limited_Type (Etype (F))
3316 or else Is_Limited_Type (Etype (Expression (A))))
3319 ("conversion between unrelated limited array types " &
3320 "not allowed (\A\I-00246)", A);
3322 if Is_Limited_Type (Etype (F)) then
3323 Explain_Limited_Type (Etype (F), A);
3326 if Is_Limited_Type (Etype (Expression (A))) then
3327 Explain_Limited_Type (Etype (Expression (A)), A);
3331 -- (Ada 2005: AI-251): If the actual is an allocator whose
3332 -- directly designated type is a class-wide interface, we build
3333 -- an anonymous access type to use it as the type of the
3334 -- allocator. Later, when the subprogram call is expanded, if
3335 -- the interface has a secondary dispatch table the expander
3336 -- will add a type conversion to force the correct displacement
3339 if Nkind (A) = N_Allocator then
3341 DDT : constant Entity_Id :=
3342 Directly_Designated_Type (Base_Type (Etype (F)));
3344 New_Itype : Entity_Id;
3347 if Is_Class_Wide_Type (DDT)
3348 and then Is_Interface (DDT)
3350 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3351 Set_Etype (New_Itype, Etype (A));
3352 Set_Directly_Designated_Type (New_Itype,
3353 Directly_Designated_Type (Etype (A)));
3354 Set_Etype (A, New_Itype);
3357 -- Ada 2005, AI-162:If the actual is an allocator, the
3358 -- innermost enclosing statement is the master of the
3359 -- created object. This needs to be done with expansion
3360 -- enabled only, otherwise the transient scope will not
3361 -- be removed in the expansion of the wrapped construct.
3363 if (Is_Controlled (DDT) or else Has_Task (DDT))
3364 and then Expander_Active
3366 Establish_Transient_Scope (A, False);
3371 -- (Ada 2005): The call may be to a primitive operation of
3372 -- a tagged synchronized type, declared outside of the type.
3373 -- In this case the controlling actual must be converted to
3374 -- its corresponding record type, which is the formal type.
3375 -- The actual may be a subtype, either because of a constraint
3376 -- or because it is a generic actual, so use base type to
3377 -- locate concurrent type.
3379 A_Typ := Base_Type (Etype (A));
3380 F_Typ := Base_Type (Etype (F));
3383 Full_A_Typ : Entity_Id;
3386 if Present (Full_View (A_Typ)) then
3387 Full_A_Typ := Base_Type (Full_View (A_Typ));
3389 Full_A_Typ := A_Typ;
3392 -- Tagged synchronized type (case 1): the actual is a
3395 if Is_Concurrent_Type (A_Typ)
3396 and then Corresponding_Record_Type (A_Typ) = F_Typ
3399 Unchecked_Convert_To
3400 (Corresponding_Record_Type (A_Typ), A));
3401 Resolve (A, Etype (F));
3403 -- Tagged synchronized type (case 2): the formal is a
3406 elsif Ekind (Full_A_Typ) = E_Record_Type
3408 (Corresponding_Concurrent_Type (Full_A_Typ))
3409 and then Is_Concurrent_Type (F_Typ)
3410 and then Present (Corresponding_Record_Type (F_Typ))
3411 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3413 Resolve (A, Corresponding_Record_Type (F_Typ));
3418 Resolve (A, Etype (F));
3426 -- For mode IN, if actual is an entity, and the type of the formal
3427 -- has warnings suppressed, then we reset Never_Set_In_Source for
3428 -- the calling entity. The reason for this is to catch cases like
3429 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3430 -- uses trickery to modify an IN parameter.
3432 if Ekind (F) = E_In_Parameter
3433 and then Is_Entity_Name (A)
3434 and then Present (Entity (A))
3435 and then Ekind (Entity (A)) = E_Variable
3436 and then Has_Warnings_Off (F_Typ)
3438 Set_Never_Set_In_Source (Entity (A), False);
3441 -- Perform error checks for IN and IN OUT parameters
3443 if Ekind (F) /= E_Out_Parameter then
3445 -- Check unset reference. For scalar parameters, it is clearly
3446 -- wrong to pass an uninitialized value as either an IN or
3447 -- IN-OUT parameter. For composites, it is also clearly an
3448 -- error to pass a completely uninitialized value as an IN
3449 -- parameter, but the case of IN OUT is trickier. We prefer
3450 -- not to give a warning here. For example, suppose there is
3451 -- a routine that sets some component of a record to False.
3452 -- It is perfectly reasonable to make this IN-OUT and allow
3453 -- either initialized or uninitialized records to be passed
3456 -- For partially initialized composite values, we also avoid
3457 -- warnings, since it is quite likely that we are passing a
3458 -- partially initialized value and only the initialized fields
3459 -- will in fact be read in the subprogram.
3461 if Is_Scalar_Type (A_Typ)
3462 or else (Ekind (F) = E_In_Parameter
3463 and then not Is_Partially_Initialized_Type (A_Typ))
3465 Check_Unset_Reference (A);
3468 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3469 -- actual to a nested call, since this is case of reading an
3470 -- out parameter, which is not allowed.
3472 if Ada_Version = Ada_83
3473 and then Is_Entity_Name (A)
3474 and then Ekind (Entity (A)) = E_Out_Parameter
3476 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3480 -- Case of OUT or IN OUT parameter
3482 if Ekind (F) /= E_In_Parameter then
3484 -- For an Out parameter, check for useless assignment. Note
3485 -- that we can't set Last_Assignment this early, because we may
3486 -- kill current values in Resolve_Call, and that call would
3487 -- clobber the Last_Assignment field.
3489 -- Note: call Warn_On_Useless_Assignment before doing the check
3490 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3491 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3492 -- reflects the last assignment, not this one!
3494 if Ekind (F) = E_Out_Parameter then
3495 if Warn_On_Modified_As_Out_Parameter (F)
3496 and then Is_Entity_Name (A)
3497 and then Present (Entity (A))
3498 and then Comes_From_Source (N)
3500 Warn_On_Useless_Assignment (Entity (A), A);
3504 -- Validate the form of the actual. Note that the call to
3505 -- Is_OK_Variable_For_Out_Formal generates the required
3506 -- reference in this case.
3508 if not Is_OK_Variable_For_Out_Formal (A) then
3509 Error_Msg_NE ("actual for& must be a variable", A, F);
3512 -- What's the following about???
3514 if Is_Entity_Name (A) then
3515 Kill_Checks (Entity (A));
3521 if Etype (A) = Any_Type then
3522 Set_Etype (N, Any_Type);
3526 -- Apply appropriate range checks for in, out, and in-out
3527 -- parameters. Out and in-out parameters also need a separate
3528 -- check, if there is a type conversion, to make sure the return
3529 -- value meets the constraints of the variable before the
3532 -- Gigi looks at the check flag and uses the appropriate types.
3533 -- For now since one flag is used there is an optimization which
3534 -- might not be done in the In Out case since Gigi does not do
3535 -- any analysis. More thought required about this ???
3537 if Ekind (F) = E_In_Parameter
3538 or else Ekind (F) = E_In_Out_Parameter
3540 if Is_Scalar_Type (Etype (A)) then
3541 Apply_Scalar_Range_Check (A, F_Typ);
3543 elsif Is_Array_Type (Etype (A)) then
3544 Apply_Length_Check (A, F_Typ);
3546 elsif Is_Record_Type (F_Typ)
3547 and then Has_Discriminants (F_Typ)
3548 and then Is_Constrained (F_Typ)
3549 and then (not Is_Derived_Type (F_Typ)
3550 or else Comes_From_Source (Nam))
3552 Apply_Discriminant_Check (A, F_Typ);
3554 elsif Is_Access_Type (F_Typ)
3555 and then Is_Array_Type (Designated_Type (F_Typ))
3556 and then Is_Constrained (Designated_Type (F_Typ))
3558 Apply_Length_Check (A, F_Typ);
3560 elsif Is_Access_Type (F_Typ)
3561 and then Has_Discriminants (Designated_Type (F_Typ))
3562 and then Is_Constrained (Designated_Type (F_Typ))
3564 Apply_Discriminant_Check (A, F_Typ);
3567 Apply_Range_Check (A, F_Typ);
3570 -- Ada 2005 (AI-231)
3572 if Ada_Version >= Ada_05
3573 and then Is_Access_Type (F_Typ)
3574 and then Can_Never_Be_Null (F_Typ)
3575 and then Known_Null (A)
3577 Apply_Compile_Time_Constraint_Error
3579 Msg => "(Ada 2005) null not allowed in "
3580 & "null-excluding formal?",
3581 Reason => CE_Null_Not_Allowed);
3585 if Ekind (F) = E_Out_Parameter
3586 or else Ekind (F) = E_In_Out_Parameter
3588 if Nkind (A) = N_Type_Conversion then
3589 if Is_Scalar_Type (A_Typ) then
3590 Apply_Scalar_Range_Check
3591 (Expression (A), Etype (Expression (A)), A_Typ);
3594 (Expression (A), Etype (Expression (A)), A_Typ);
3598 if Is_Scalar_Type (F_Typ) then
3599 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3601 elsif Is_Array_Type (F_Typ)
3602 and then Ekind (F) = E_Out_Parameter
3604 Apply_Length_Check (A, F_Typ);
3607 Apply_Range_Check (A, A_Typ, F_Typ);
3612 -- An actual associated with an access parameter is implicitly
3613 -- converted to the anonymous access type of the formal and must
3614 -- satisfy the legality checks for access conversions.
3616 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3617 if not Valid_Conversion (A, F_Typ, A) then
3619 ("invalid implicit conversion for access parameter", A);
3623 -- Check bad case of atomic/volatile argument (RM C.6(12))
3625 if Is_By_Reference_Type (Etype (F))
3626 and then Comes_From_Source (N)
3628 if Is_Atomic_Object (A)
3629 and then not Is_Atomic (Etype (F))
3632 ("cannot pass atomic argument to non-atomic formal",
3635 elsif Is_Volatile_Object (A)
3636 and then not Is_Volatile (Etype (F))
3639 ("cannot pass volatile argument to non-volatile formal",
3644 -- Check that subprograms don't have improper controlling
3645 -- arguments (RM 3.9.2 (9)).
3647 -- A primitive operation may have an access parameter of an
3648 -- incomplete tagged type, but a dispatching call is illegal
3649 -- if the type is still incomplete.
3651 if Is_Controlling_Formal (F) then
3652 Set_Is_Controlling_Actual (A);
3654 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3656 Desig : constant Entity_Id := Designated_Type (Etype (F));
3658 if Ekind (Desig) = E_Incomplete_Type
3659 and then No (Full_View (Desig))
3660 and then No (Non_Limited_View (Desig))
3663 ("premature use of incomplete type& " &
3664 "in dispatching call", A, Desig);
3669 elsif Nkind (A) = N_Explicit_Dereference then
3670 Validate_Remote_Access_To_Class_Wide_Type (A);
3673 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3674 and then not Is_Class_Wide_Type (F_Typ)
3675 and then not Is_Controlling_Formal (F)
3677 Error_Msg_N ("class-wide argument not allowed here!", A);
3679 if Is_Subprogram (Nam)
3680 and then Comes_From_Source (Nam)
3682 Error_Msg_Node_2 := F_Typ;
3684 ("& is not a dispatching operation of &!", A, Nam);
3687 elsif Is_Access_Type (A_Typ)
3688 and then Is_Access_Type (F_Typ)
3689 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3690 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3691 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3692 or else (Nkind (A) = N_Attribute_Reference
3694 Is_Class_Wide_Type (Etype (Prefix (A)))))
3695 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3696 and then not Is_Controlling_Formal (F)
3698 -- Disable these checks for call to imported C++ subprograms
3701 (Is_Entity_Name (Name (N))
3702 and then Is_Imported (Entity (Name (N)))
3703 and then Convention (Entity (Name (N))) = Convention_CPP)
3706 ("access to class-wide argument not allowed here!", A);
3708 if Is_Subprogram (Nam)
3709 and then Comes_From_Source (Nam)
3711 Error_Msg_Node_2 := Designated_Type (F_Typ);
3713 ("& is not a dispatching operation of &!", A, Nam);
3719 -- If it is a named association, treat the selector_name as
3720 -- a proper identifier, and mark the corresponding entity.
3722 if Nkind (Parent (A)) = N_Parameter_Association then
3723 Set_Entity (Selector_Name (Parent (A)), F);
3724 Generate_Reference (F, Selector_Name (Parent (A)));
3725 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3726 Generate_Reference (F_Typ, N, ' ');
3731 if Ekind (F) /= E_Out_Parameter then
3732 Check_Unset_Reference (A);
3737 -- Case where actual is not present
3745 end Resolve_Actuals;
3747 -----------------------
3748 -- Resolve_Allocator --
3749 -----------------------
3751 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3752 E : constant Node_Id := Expression (N);
3754 Discrim : Entity_Id;
3757 Assoc : Node_Id := Empty;
3760 procedure Check_Allocator_Discrim_Accessibility
3761 (Disc_Exp : Node_Id;
3762 Alloc_Typ : Entity_Id);
3763 -- Check that accessibility level associated with an access discriminant
3764 -- initialized in an allocator by the expression Disc_Exp is not deeper
3765 -- than the level of the allocator type Alloc_Typ. An error message is
3766 -- issued if this condition is violated. Specialized checks are done for
3767 -- the cases of a constraint expression which is an access attribute or
3768 -- an access discriminant.
3770 function In_Dispatching_Context return Boolean;
3771 -- If the allocator is an actual in a call, it is allowed to be class-
3772 -- wide when the context is not because it is a controlling actual.
3774 procedure Propagate_Coextensions (Root : Node_Id);
3775 -- Propagate all nested coextensions which are located one nesting
3776 -- level down the tree to the node Root. Example:
3779 -- Level_1_Coextension
3780 -- Level_2_Coextension
3782 -- The algorithm is paired with delay actions done by the Expander. In
3783 -- the above example, assume all coextensions are controlled types.
3784 -- The cycle of analysis, resolution and expansion will yield:
3786 -- 1) Analyze Top_Record
3787 -- 2) Analyze Level_1_Coextension
3788 -- 3) Analyze Level_2_Coextension
3789 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3791 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3792 -- generated to capture the allocated object. Temp_1 is attached
3793 -- to the coextension chain of Level_2_Coextension.
3794 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3795 -- coextension. A forward tree traversal is performed which finds
3796 -- Level_2_Coextension's list and copies its contents into its
3798 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3799 -- generated to capture the allocated object. Temp_2 is attached
3800 -- to the coextension chain of Level_1_Coextension. Currently, the
3801 -- contents of the list are [Temp_2, Temp_1].
3802 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3803 -- finds Level_1_Coextension's list and copies its contents into
3805 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3806 -- Temp_2 and attach them to Top_Record's finalization list.
3808 -------------------------------------------
3809 -- Check_Allocator_Discrim_Accessibility --
3810 -------------------------------------------
3812 procedure Check_Allocator_Discrim_Accessibility
3813 (Disc_Exp : Node_Id;
3814 Alloc_Typ : Entity_Id)
3817 if Type_Access_Level (Etype (Disc_Exp)) >
3818 Type_Access_Level (Alloc_Typ)
3821 ("operand type has deeper level than allocator type", Disc_Exp);
3823 -- When the expression is an Access attribute the level of the prefix
3824 -- object must not be deeper than that of the allocator's type.
3826 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3827 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3829 and then Object_Access_Level (Prefix (Disc_Exp))
3830 > Type_Access_Level (Alloc_Typ)
3833 ("prefix of attribute has deeper level than allocator type",
3836 -- When the expression is an access discriminant the check is against
3837 -- the level of the prefix object.
3839 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3840 and then Nkind (Disc_Exp) = N_Selected_Component
3841 and then Object_Access_Level (Prefix (Disc_Exp))
3842 > Type_Access_Level (Alloc_Typ)
3845 ("access discriminant has deeper level than allocator type",
3848 -- All other cases are legal
3853 end Check_Allocator_Discrim_Accessibility;
3855 ----------------------------
3856 -- In_Dispatching_Context --
3857 ----------------------------
3859 function In_Dispatching_Context return Boolean is
3860 Par : constant Node_Id := Parent (N);
3862 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3863 and then Is_Entity_Name (Name (Par))
3864 and then Is_Dispatching_Operation (Entity (Name (Par)));
3865 end In_Dispatching_Context;
3867 ----------------------------
3868 -- Propagate_Coextensions --
3869 ----------------------------
3871 procedure Propagate_Coextensions (Root : Node_Id) is
3873 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3874 -- Copy the contents of list From into list To, preserving the
3875 -- order of elements.
3877 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3878 -- Recognize an allocator or a rewritten allocator node and add it
3879 -- along with its nested coextensions to the list of Root.
3885 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3886 From_Elmt : Elmt_Id;
3888 From_Elmt := First_Elmt (From);
3889 while Present (From_Elmt) loop
3890 Append_Elmt (Node (From_Elmt), To);
3891 Next_Elmt (From_Elmt);
3895 -----------------------
3896 -- Process_Allocator --
3897 -----------------------
3899 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3900 Orig_Nod : Node_Id := Nod;
3903 -- This is a possible rewritten subtype indication allocator. Any
3904 -- nested coextensions will appear as discriminant constraints.
3906 if Nkind (Nod) = N_Identifier
3907 and then Present (Original_Node (Nod))
3908 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3912 Discr_Elmt : Elmt_Id;
3915 if Is_Record_Type (Entity (Nod)) then
3917 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3918 while Present (Discr_Elmt) loop
3919 Discr := Node (Discr_Elmt);
3921 if Nkind (Discr) = N_Identifier
3922 and then Present (Original_Node (Discr))
3923 and then Nkind (Original_Node (Discr)) = N_Allocator
3924 and then Present (Coextensions (
3925 Original_Node (Discr)))
3927 if No (Coextensions (Root)) then
3928 Set_Coextensions (Root, New_Elmt_List);
3932 (From => Coextensions (Original_Node (Discr)),
3933 To => Coextensions (Root));
3936 Next_Elmt (Discr_Elmt);
3939 -- There is no need to continue the traversal of this
3940 -- subtree since all the information has already been
3947 -- Case of either a stand alone allocator or a rewritten allocator
3948 -- with an aggregate.
3951 if Present (Original_Node (Nod)) then
3952 Orig_Nod := Original_Node (Nod);
3955 if Nkind (Orig_Nod) = N_Allocator then
3957 -- Propagate the list of nested coextensions to the Root
3958 -- allocator. This is done through list copy since a single
3959 -- allocator may have multiple coextensions. Do not touch
3960 -- coextensions roots.
3962 if not Is_Coextension_Root (Orig_Nod)
3963 and then Present (Coextensions (Orig_Nod))
3965 if No (Coextensions (Root)) then
3966 Set_Coextensions (Root, New_Elmt_List);
3970 (From => Coextensions (Orig_Nod),
3971 To => Coextensions (Root));
3974 -- There is no need to continue the traversal of this
3975 -- subtree since all the information has already been
3982 -- Keep on traversing, looking for the next allocator
3985 end Process_Allocator;
3987 procedure Process_Allocators is
3988 new Traverse_Proc (Process_Allocator);
3990 -- Start of processing for Propagate_Coextensions
3993 Process_Allocators (Expression (Root));
3994 end Propagate_Coextensions;
3996 -- Start of processing for Resolve_Allocator
3999 -- Replace general access with specific type
4001 if Ekind (Etype (N)) = E_Allocator_Type then
4002 Set_Etype (N, Base_Type (Typ));
4005 if Is_Abstract_Type (Typ) then
4006 Error_Msg_N ("type of allocator cannot be abstract", N);
4009 -- For qualified expression, resolve the expression using the
4010 -- given subtype (nothing to do for type mark, subtype indication)
4012 if Nkind (E) = N_Qualified_Expression then
4013 if Is_Class_Wide_Type (Etype (E))
4014 and then not Is_Class_Wide_Type (Designated_Type (Typ))
4015 and then not In_Dispatching_Context
4018 ("class-wide allocator not allowed for this access type", N);
4021 Resolve (Expression (E), Etype (E));
4022 Check_Unset_Reference (Expression (E));
4024 -- A qualified expression requires an exact match of the type,
4025 -- class-wide matching is not allowed.
4027 if (Is_Class_Wide_Type (Etype (Expression (E)))
4028 or else Is_Class_Wide_Type (Etype (E)))
4029 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4031 Wrong_Type (Expression (E), Etype (E));
4034 -- A special accessibility check is needed for allocators that
4035 -- constrain access discriminants. The level of the type of the
4036 -- expression used to constrain an access discriminant cannot be
4037 -- deeper than the type of the allocator (in contrast to access
4038 -- parameters, where the level of the actual can be arbitrary).
4040 -- We can't use Valid_Conversion to perform this check because
4041 -- in general the type of the allocator is unrelated to the type
4042 -- of the access discriminant.
4044 if Ekind (Typ) /= E_Anonymous_Access_Type
4045 or else Is_Local_Anonymous_Access (Typ)
4047 Subtyp := Entity (Subtype_Mark (E));
4049 Aggr := Original_Node (Expression (E));
4051 if Has_Discriminants (Subtyp)
4052 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4054 Discrim := First_Discriminant (Base_Type (Subtyp));
4056 -- Get the first component expression of the aggregate
4058 if Present (Expressions (Aggr)) then
4059 Disc_Exp := First (Expressions (Aggr));
4061 elsif Present (Component_Associations (Aggr)) then
4062 Assoc := First (Component_Associations (Aggr));
4064 if Present (Assoc) then
4065 Disc_Exp := Expression (Assoc);
4074 while Present (Discrim) and then Present (Disc_Exp) loop
4075 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4076 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4079 Next_Discriminant (Discrim);
4081 if Present (Discrim) then
4082 if Present (Assoc) then
4084 Disc_Exp := Expression (Assoc);
4086 elsif Present (Next (Disc_Exp)) then
4090 Assoc := First (Component_Associations (Aggr));
4092 if Present (Assoc) then
4093 Disc_Exp := Expression (Assoc);
4103 -- For a subtype mark or subtype indication, freeze the subtype
4106 Freeze_Expression (E);
4108 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4110 ("initialization required for access-to-constant allocator", N);
4113 -- A special accessibility check is needed for allocators that
4114 -- constrain access discriminants. The level of the type of the
4115 -- expression used to constrain an access discriminant cannot be
4116 -- deeper than the type of the allocator (in contrast to access
4117 -- parameters, where the level of the actual can be arbitrary).
4118 -- We can't use Valid_Conversion to perform this check because
4119 -- in general the type of the allocator is unrelated to the type
4120 -- of the access discriminant.
4122 if Nkind (Original_Node (E)) = N_Subtype_Indication
4123 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4124 or else Is_Local_Anonymous_Access (Typ))
4126 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4128 if Has_Discriminants (Subtyp) then
4129 Discrim := First_Discriminant (Base_Type (Subtyp));
4130 Constr := First (Constraints (Constraint (Original_Node (E))));
4131 while Present (Discrim) and then Present (Constr) loop
4132 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4133 if Nkind (Constr) = N_Discriminant_Association then
4134 Disc_Exp := Original_Node (Expression (Constr));
4136 Disc_Exp := Original_Node (Constr);
4139 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4142 Next_Discriminant (Discrim);
4149 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4150 -- check that the level of the type of the created object is not deeper
4151 -- than the level of the allocator's access type, since extensions can
4152 -- now occur at deeper levels than their ancestor types. This is a
4153 -- static accessibility level check; a run-time check is also needed in
4154 -- the case of an initialized allocator with a class-wide argument (see
4155 -- Expand_Allocator_Expression).
4157 if Ada_Version >= Ada_05
4158 and then Is_Class_Wide_Type (Designated_Type (Typ))
4161 Exp_Typ : Entity_Id;
4164 if Nkind (E) = N_Qualified_Expression then
4165 Exp_Typ := Etype (E);
4166 elsif Nkind (E) = N_Subtype_Indication then
4167 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4169 Exp_Typ := Entity (E);
4172 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4173 if In_Instance_Body then
4174 Error_Msg_N ("?type in allocator has deeper level than" &
4175 " designated class-wide type", E);
4176 Error_Msg_N ("\?Program_Error will be raised at run time",
4179 Make_Raise_Program_Error (Sloc (N),
4180 Reason => PE_Accessibility_Check_Failed));
4183 -- Do not apply Ada 2005 accessibility checks on a class-wide
4184 -- allocator if the type given in the allocator is a formal
4185 -- type. A run-time check will be performed in the instance.
4187 elsif not Is_Generic_Type (Exp_Typ) then
4188 Error_Msg_N ("type in allocator has deeper level than" &
4189 " designated class-wide type", E);
4195 -- Check for allocation from an empty storage pool
4197 if No_Pool_Assigned (Typ) then
4199 Loc : constant Source_Ptr := Sloc (N);
4201 Error_Msg_N ("?allocation from empty storage pool!", N);
4202 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4204 Make_Raise_Storage_Error (Loc,
4205 Reason => SE_Empty_Storage_Pool));
4208 -- If the context is an unchecked conversion, as may happen within
4209 -- an inlined subprogram, the allocator is being resolved with its
4210 -- own anonymous type. In that case, if the target type has a specific
4211 -- storage pool, it must be inherited explicitly by the allocator type.
4213 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4214 and then No (Associated_Storage_Pool (Typ))
4216 Set_Associated_Storage_Pool
4217 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4220 -- An erroneous allocator may be rewritten as a raise Program_Error
4223 if Nkind (N) = N_Allocator then
4225 -- An anonymous access discriminant is the definition of a
4228 if Ekind (Typ) = E_Anonymous_Access_Type
4229 and then Nkind (Associated_Node_For_Itype (Typ)) =
4230 N_Discriminant_Specification
4232 -- Avoid marking an allocator as a dynamic coextension if it is
4233 -- within a static construct.
4235 if not Is_Static_Coextension (N) then
4236 Set_Is_Dynamic_Coextension (N);
4239 -- Cleanup for potential static coextensions
4242 Set_Is_Dynamic_Coextension (N, False);
4243 Set_Is_Static_Coextension (N, False);
4246 -- There is no need to propagate any nested coextensions if they
4247 -- are marked as static since they will be rewritten on the spot.
4249 if not Is_Static_Coextension (N) then
4250 Propagate_Coextensions (N);
4253 end Resolve_Allocator;
4255 ---------------------------
4256 -- Resolve_Arithmetic_Op --
4257 ---------------------------
4259 -- Used for resolving all arithmetic operators except exponentiation
4261 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4262 L : constant Node_Id := Left_Opnd (N);
4263 R : constant Node_Id := Right_Opnd (N);
4264 TL : constant Entity_Id := Base_Type (Etype (L));
4265 TR : constant Entity_Id := Base_Type (Etype (R));
4269 B_Typ : constant Entity_Id := Base_Type (Typ);
4270 -- We do the resolution using the base type, because intermediate values
4271 -- in expressions always are of the base type, not a subtype of it.
4273 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4274 -- Returns True if N is in a context that expects "any real type"
4276 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4277 -- Return True iff given type is Integer or universal real/integer
4279 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4280 -- Choose type of integer literal in fixed-point operation to conform
4281 -- to available fixed-point type. T is the type of the other operand,
4282 -- which is needed to determine the expected type of N.
4284 procedure Set_Operand_Type (N : Node_Id);
4285 -- Set operand type to T if universal
4287 -------------------------------
4288 -- Expected_Type_Is_Any_Real --
4289 -------------------------------
4291 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4293 -- N is the expression after "delta" in a fixed_point_definition;
4296 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4297 N_Decimal_Fixed_Point_Definition,
4299 -- N is one of the bounds in a real_range_specification;
4302 N_Real_Range_Specification,
4304 -- N is the expression of a delta_constraint;
4307 N_Delta_Constraint);
4308 end Expected_Type_Is_Any_Real;
4310 -----------------------------
4311 -- Is_Integer_Or_Universal --
4312 -----------------------------
4314 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4316 Index : Interp_Index;
4320 if not Is_Overloaded (N) then
4322 return Base_Type (T) = Base_Type (Standard_Integer)
4323 or else T = Universal_Integer
4324 or else T = Universal_Real;
4326 Get_First_Interp (N, Index, It);
4327 while Present (It.Typ) loop
4328 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4329 or else It.Typ = Universal_Integer
4330 or else It.Typ = Universal_Real
4335 Get_Next_Interp (Index, It);
4340 end Is_Integer_Or_Universal;
4342 ----------------------------
4343 -- Set_Mixed_Mode_Operand --
4344 ----------------------------
4346 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4347 Index : Interp_Index;
4351 if Universal_Interpretation (N) = Universal_Integer then
4353 -- A universal integer literal is resolved as standard integer
4354 -- except in the case of a fixed-point result, where we leave it
4355 -- as universal (to be handled by Exp_Fixd later on)
4357 if Is_Fixed_Point_Type (T) then
4358 Resolve (N, Universal_Integer);
4360 Resolve (N, Standard_Integer);
4363 elsif Universal_Interpretation (N) = Universal_Real
4364 and then (T = Base_Type (Standard_Integer)
4365 or else T = Universal_Integer
4366 or else T = Universal_Real)
4368 -- A universal real can appear in a fixed-type context. We resolve
4369 -- the literal with that context, even though this might raise an
4370 -- exception prematurely (the other operand may be zero).
4374 elsif Etype (N) = Base_Type (Standard_Integer)
4375 and then T = Universal_Real
4376 and then Is_Overloaded (N)
4378 -- Integer arg in mixed-mode operation. Resolve with universal
4379 -- type, in case preference rule must be applied.
4381 Resolve (N, Universal_Integer);
4384 and then B_Typ /= Universal_Fixed
4386 -- Not a mixed-mode operation, resolve with context
4390 elsif Etype (N) = Any_Fixed then
4392 -- N may itself be a mixed-mode operation, so use context type
4396 elsif Is_Fixed_Point_Type (T)
4397 and then B_Typ = Universal_Fixed
4398 and then Is_Overloaded (N)
4400 -- Must be (fixed * fixed) operation, operand must have one
4401 -- compatible interpretation.
4403 Resolve (N, Any_Fixed);
4405 elsif Is_Fixed_Point_Type (B_Typ)
4406 and then (T = Universal_Real
4407 or else Is_Fixed_Point_Type (T))
4408 and then Is_Overloaded (N)
4410 -- C * F(X) in a fixed context, where C is a real literal or a
4411 -- fixed-point expression. F must have either a fixed type
4412 -- interpretation or an integer interpretation, but not both.
4414 Get_First_Interp (N, Index, It);
4415 while Present (It.Typ) loop
4416 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4418 if Analyzed (N) then
4419 Error_Msg_N ("ambiguous operand in fixed operation", N);
4421 Resolve (N, Standard_Integer);
4424 elsif Is_Fixed_Point_Type (It.Typ) then
4426 if Analyzed (N) then
4427 Error_Msg_N ("ambiguous operand in fixed operation", N);
4429 Resolve (N, It.Typ);
4433 Get_Next_Interp (Index, It);
4436 -- Reanalyze the literal with the fixed type of the context. If
4437 -- context is Universal_Fixed, we are within a conversion, leave
4438 -- the literal as a universal real because there is no usable
4439 -- fixed type, and the target of the conversion plays no role in
4453 if B_Typ = Universal_Fixed
4454 and then Nkind (Op2) = N_Real_Literal
4456 T2 := Universal_Real;
4461 Set_Analyzed (Op2, False);
4468 end Set_Mixed_Mode_Operand;
4470 ----------------------
4471 -- Set_Operand_Type --
4472 ----------------------
4474 procedure Set_Operand_Type (N : Node_Id) is
4476 if Etype (N) = Universal_Integer
4477 or else Etype (N) = Universal_Real
4481 end Set_Operand_Type;
4483 -- Start of processing for Resolve_Arithmetic_Op
4486 if Comes_From_Source (N)
4487 and then Ekind (Entity (N)) = E_Function
4488 and then Is_Imported (Entity (N))
4489 and then Is_Intrinsic_Subprogram (Entity (N))
4491 Resolve_Intrinsic_Operator (N, Typ);
4494 -- Special-case for mixed-mode universal expressions or fixed point
4495 -- type operation: each argument is resolved separately. The same
4496 -- treatment is required if one of the operands of a fixed point
4497 -- operation is universal real, since in this case we don't do a
4498 -- conversion to a specific fixed-point type (instead the expander
4499 -- takes care of the case).
4501 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4502 and then Present (Universal_Interpretation (L))
4503 and then Present (Universal_Interpretation (R))
4505 Resolve (L, Universal_Interpretation (L));
4506 Resolve (R, Universal_Interpretation (R));
4507 Set_Etype (N, B_Typ);
4509 elsif (B_Typ = Universal_Real
4510 or else Etype (N) = Universal_Fixed
4511 or else (Etype (N) = Any_Fixed
4512 and then Is_Fixed_Point_Type (B_Typ))
4513 or else (Is_Fixed_Point_Type (B_Typ)
4514 and then (Is_Integer_Or_Universal (L)
4516 Is_Integer_Or_Universal (R))))
4517 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4519 if TL = Universal_Integer or else TR = Universal_Integer then
4520 Check_For_Visible_Operator (N, B_Typ);
4523 -- If context is a fixed type and one operand is integer, the
4524 -- other is resolved with the type of the context.
4526 if Is_Fixed_Point_Type (B_Typ)
4527 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4528 or else TL = Universal_Integer)
4533 elsif Is_Fixed_Point_Type (B_Typ)
4534 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4535 or else TR = Universal_Integer)
4541 Set_Mixed_Mode_Operand (L, TR);
4542 Set_Mixed_Mode_Operand (R, TL);
4545 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4546 -- multiplying operators from being used when the expected type is
4547 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4548 -- some cases where the expected type is actually Any_Real;
4549 -- Expected_Type_Is_Any_Real takes care of that case.
4551 if Etype (N) = Universal_Fixed
4552 or else Etype (N) = Any_Fixed
4554 if B_Typ = Universal_Fixed
4555 and then not Expected_Type_Is_Any_Real (N)
4556 and then not Nkind_In (Parent (N), N_Type_Conversion,
4557 N_Unchecked_Type_Conversion)
4559 Error_Msg_N ("type cannot be determined from context!", N);
4560 Error_Msg_N ("\explicit conversion to result type required", N);
4562 Set_Etype (L, Any_Type);
4563 Set_Etype (R, Any_Type);
4566 if Ada_Version = Ada_83
4567 and then Etype (N) = Universal_Fixed
4569 Nkind_In (Parent (N), N_Type_Conversion,
4570 N_Unchecked_Type_Conversion)
4573 ("(Ada 83) fixed-point operation "
4574 & "needs explicit conversion", N);
4577 -- The expected type is "any real type" in contexts like
4578 -- type T is delta <universal_fixed-expression> ...
4579 -- in which case we need to set the type to Universal_Real
4580 -- so that static expression evaluation will work properly.
4582 if Expected_Type_Is_Any_Real (N) then
4583 Set_Etype (N, Universal_Real);
4585 Set_Etype (N, B_Typ);
4589 elsif Is_Fixed_Point_Type (B_Typ)
4590 and then (Is_Integer_Or_Universal (L)
4591 or else Nkind (L) = N_Real_Literal
4592 or else Nkind (R) = N_Real_Literal
4593 or else Is_Integer_Or_Universal (R))
4595 Set_Etype (N, B_Typ);
4597 elsif Etype (N) = Any_Fixed then
4599 -- If no previous errors, this is only possible if one operand
4600 -- is overloaded and the context is universal. Resolve as such.
4602 Set_Etype (N, B_Typ);
4606 if (TL = Universal_Integer or else TL = Universal_Real)
4608 (TR = Universal_Integer or else TR = Universal_Real)
4610 Check_For_Visible_Operator (N, B_Typ);
4613 -- If the context is Universal_Fixed and the operands are also
4614 -- universal fixed, this is an error, unless there is only one
4615 -- applicable fixed_point type (usually duration).
4617 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4618 T := Unique_Fixed_Point_Type (N);
4620 if T = Any_Type then
4633 -- If one of the arguments was resolved to a non-universal type.
4634 -- label the result of the operation itself with the same type.
4635 -- Do the same for the universal argument, if any.
4637 T := Intersect_Types (L, R);
4638 Set_Etype (N, Base_Type (T));
4639 Set_Operand_Type (L);
4640 Set_Operand_Type (R);
4643 Generate_Operator_Reference (N, Typ);
4644 Eval_Arithmetic_Op (N);
4646 -- Set overflow and division checking bit. Much cleverer code needed
4647 -- here eventually and perhaps the Resolve routines should be separated
4648 -- for the various arithmetic operations, since they will need
4649 -- different processing. ???
4651 if Nkind (N) in N_Op then
4652 if not Overflow_Checks_Suppressed (Etype (N)) then
4653 Enable_Overflow_Check (N);
4656 -- Give warning if explicit division by zero
4658 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4659 and then not Division_Checks_Suppressed (Etype (N))
4661 Rop := Right_Opnd (N);
4663 if Compile_Time_Known_Value (Rop)
4664 and then ((Is_Integer_Type (Etype (Rop))
4665 and then Expr_Value (Rop) = Uint_0)
4667 (Is_Real_Type (Etype (Rop))
4668 and then Expr_Value_R (Rop) = Ureal_0))
4670 -- Specialize the warning message according to the operation
4674 Apply_Compile_Time_Constraint_Error
4675 (N, "division by zero?", CE_Divide_By_Zero,
4676 Loc => Sloc (Right_Opnd (N)));
4679 Apply_Compile_Time_Constraint_Error
4680 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4681 Loc => Sloc (Right_Opnd (N)));
4684 Apply_Compile_Time_Constraint_Error
4685 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4686 Loc => Sloc (Right_Opnd (N)));
4688 -- Division by zero can only happen with division, rem,
4689 -- and mod operations.
4692 raise Program_Error;
4695 -- Otherwise just set the flag to check at run time
4698 Activate_Division_Check (N);
4702 -- If Restriction No_Implicit_Conditionals is active, then it is
4703 -- violated if either operand can be negative for mod, or for rem
4704 -- if both operands can be negative.
4706 if Restrictions.Set (No_Implicit_Conditionals)
4707 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4716 -- Set if corresponding operand might be negative
4720 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4721 LNeg := (not OK) or else Lo < 0;
4724 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
4725 RNeg := (not OK) or else Lo < 0;
4727 -- Check if we will be generating conditionals. There are two
4728 -- cases where that can happen, first for REM, the only case
4729 -- is largest negative integer mod -1, where the division can
4730 -- overflow, but we still have to give the right result. The
4731 -- front end generates a test for this annoying case. Here we
4732 -- just test if both operands can be negative (that's what the
4733 -- expander does, so we match its logic here).
4735 -- The second case is mod where either operand can be negative.
4736 -- In this case, the back end has to generate additonal tests.
4738 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4740 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4742 Check_Restriction (No_Implicit_Conditionals, N);
4748 Check_Unset_Reference (L);
4749 Check_Unset_Reference (R);
4750 end Resolve_Arithmetic_Op;
4756 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4757 Loc : constant Source_Ptr := Sloc (N);
4758 Subp : constant Node_Id := Name (N);
4767 -- The context imposes a unique interpretation with type Typ on a
4768 -- procedure or function call. Find the entity of the subprogram that
4769 -- yields the expected type, and propagate the corresponding formal
4770 -- constraints on the actuals. The caller has established that an
4771 -- interpretation exists, and emitted an error if not unique.
4773 -- First deal with the case of a call to an access-to-subprogram,
4774 -- dereference made explicit in Analyze_Call.
4776 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4777 if not Is_Overloaded (Subp) then
4778 Nam := Etype (Subp);
4781 -- Find the interpretation whose type (a subprogram type) has a
4782 -- return type that is compatible with the context. Analysis of
4783 -- the node has established that one exists.
4787 Get_First_Interp (Subp, I, It);
4788 while Present (It.Typ) loop
4789 if Covers (Typ, Etype (It.Typ)) then
4794 Get_Next_Interp (I, It);
4798 raise Program_Error;
4802 -- If the prefix is not an entity, then resolve it
4804 if not Is_Entity_Name (Subp) then
4805 Resolve (Subp, Nam);
4808 -- For an indirect call, we always invalidate checks, since we do not
4809 -- know whether the subprogram is local or global. Yes we could do
4810 -- better here, e.g. by knowing that there are no local subprograms,
4811 -- but it does not seem worth the effort. Similarly, we kill all
4812 -- knowledge of current constant values.
4814 Kill_Current_Values;
4816 -- If this is a procedure call which is really an entry call, do
4817 -- the conversion of the procedure call to an entry call. Protected
4818 -- operations use the same circuitry because the name in the call
4819 -- can be an arbitrary expression with special resolution rules.
4821 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4822 or else (Is_Entity_Name (Subp)
4823 and then Ekind (Entity (Subp)) = E_Entry)
4825 Resolve_Entry_Call (N, Typ);
4826 Check_Elab_Call (N);
4828 -- Kill checks and constant values, as above for indirect case
4829 -- Who knows what happens when another task is activated?
4831 Kill_Current_Values;
4834 -- Normal subprogram call with name established in Resolve
4836 elsif not (Is_Type (Entity (Subp))) then
4837 Nam := Entity (Subp);
4838 Set_Entity_With_Style_Check (Subp, Nam);
4840 -- Otherwise we must have the case of an overloaded call
4843 pragma Assert (Is_Overloaded (Subp));
4845 -- Initialize Nam to prevent warning (we know it will be assigned
4846 -- in the loop below, but the compiler does not know that).
4850 Get_First_Interp (Subp, I, It);
4851 while Present (It.Typ) loop
4852 if Covers (Typ, It.Typ) then
4854 Set_Entity_With_Style_Check (Subp, Nam);
4858 Get_Next_Interp (I, It);
4862 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4863 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4864 and then Nkind (Subp) /= N_Explicit_Dereference
4865 and then Present (Parameter_Associations (N))
4867 -- The prefix is a parameterless function call that returns an access
4868 -- to subprogram. If parameters are present in the current call, add
4869 -- add an explicit dereference. We use the base type here because
4870 -- within an instance these may be subtypes.
4872 -- The dereference is added either in Analyze_Call or here. Should
4873 -- be consolidated ???
4875 Set_Is_Overloaded (Subp, False);
4876 Set_Etype (Subp, Etype (Nam));
4877 Insert_Explicit_Dereference (Subp);
4878 Nam := Designated_Type (Etype (Nam));
4879 Resolve (Subp, Nam);
4882 -- Check that a call to Current_Task does not occur in an entry body
4884 if Is_RTE (Nam, RE_Current_Task) then
4893 -- Exclude calls that occur within the default of a formal
4894 -- parameter of the entry, since those are evaluated outside
4897 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4899 if Nkind (P) = N_Entry_Body
4900 or else (Nkind (P) = N_Subprogram_Body
4901 and then Is_Entry_Barrier_Function (P))
4905 ("?& should not be used in entry body (RM C.7(17))",
4908 ("\Program_Error will be raised at run time?", N, Nam);
4910 Make_Raise_Program_Error (Loc,
4911 Reason => PE_Current_Task_In_Entry_Body));
4912 Set_Etype (N, Rtype);
4919 -- Check that a procedure call does not occur in the context of the
4920 -- entry call statement of a conditional or timed entry call. Note that
4921 -- the case of a call to a subprogram renaming of an entry will also be
4922 -- rejected. The test for N not being an N_Entry_Call_Statement is
4923 -- defensive, covering the possibility that the processing of entry
4924 -- calls might reach this point due to later modifications of the code
4927 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4928 and then Nkind (N) /= N_Entry_Call_Statement
4929 and then Entry_Call_Statement (Parent (N)) = N
4931 if Ada_Version < Ada_05 then
4932 Error_Msg_N ("entry call required in select statement", N);
4934 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4935 -- for a procedure_or_entry_call, the procedure_name or
4936 -- procedure_prefix of the procedure_call_statement shall denote
4937 -- an entry renamed by a procedure, or (a view of) a primitive
4938 -- subprogram of a limited interface whose first parameter is
4939 -- a controlling parameter.
4941 elsif Nkind (N) = N_Procedure_Call_Statement
4942 and then not Is_Renamed_Entry (Nam)
4943 and then not Is_Controlling_Limited_Procedure (Nam)
4946 ("entry call or dispatching primitive of interface required", N);
4950 -- Check that this is not a call to a protected procedure or entry from
4951 -- within a protected function.
4953 if Ekind (Current_Scope) = E_Function
4954 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4955 and then Ekind (Nam) /= E_Function
4956 and then Scope (Nam) = Scope (Current_Scope)
4958 Error_Msg_N ("within protected function, protected " &
4959 "object is constant", N);
4960 Error_Msg_N ("\cannot call operation that may modify it", N);
4963 -- Freeze the subprogram name if not in a spec-expression. Note that we
4964 -- freeze procedure calls as well as function calls. Procedure calls are
4965 -- not frozen according to the rules (RM 13.14(14)) because it is
4966 -- impossible to have a procedure call to a non-frozen procedure in pure
4967 -- Ada, but in the code that we generate in the expander, this rule
4968 -- needs extending because we can generate procedure calls that need
4971 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4972 Freeze_Expression (Subp);
4975 -- For a predefined operator, the type of the result is the type imposed
4976 -- by context, except for a predefined operation on universal fixed.
4977 -- Otherwise The type of the call is the type returned by the subprogram
4980 if Is_Predefined_Op (Nam) then
4981 if Etype (N) /= Universal_Fixed then
4985 -- If the subprogram returns an array type, and the context requires the
4986 -- component type of that array type, the node is really an indexing of
4987 -- the parameterless call. Resolve as such. A pathological case occurs
4988 -- when the type of the component is an access to the array type. In
4989 -- this case the call is truly ambiguous.
4991 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4993 ((Is_Array_Type (Etype (Nam))
4994 and then Covers (Typ, Component_Type (Etype (Nam))))
4995 or else (Is_Access_Type (Etype (Nam))
4996 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4999 Component_Type (Designated_Type (Etype (Nam))))))
5002 Index_Node : Node_Id;
5004 Ret_Type : constant Entity_Id := Etype (Nam);
5007 if Is_Access_Type (Ret_Type)
5008 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5011 ("cannot disambiguate function call and indexing", N);
5013 New_Subp := Relocate_Node (Subp);
5014 Set_Entity (Subp, Nam);
5016 if (Is_Array_Type (Ret_Type)
5017 and then Component_Type (Ret_Type) /= Any_Type)
5019 (Is_Access_Type (Ret_Type)
5021 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5023 if Needs_No_Actuals (Nam) then
5025 -- Indexed call to a parameterless function
5028 Make_Indexed_Component (Loc,
5030 Make_Function_Call (Loc,
5032 Expressions => Parameter_Associations (N));
5034 -- An Ada 2005 prefixed call to a primitive operation
5035 -- whose first parameter is the prefix. This prefix was
5036 -- prepended to the parameter list, which is actually a
5037 -- list of indices. Remove the prefix in order to build
5038 -- the proper indexed component.
5041 Make_Indexed_Component (Loc,
5043 Make_Function_Call (Loc,
5045 Parameter_Associations =>
5047 (Remove_Head (Parameter_Associations (N)))),
5048 Expressions => Parameter_Associations (N));
5051 -- Since we are correcting a node classification error made
5052 -- by the parser, we call Replace rather than Rewrite.
5054 Replace (N, Index_Node);
5055 Set_Etype (Prefix (N), Ret_Type);
5057 Resolve_Indexed_Component (N, Typ);
5058 Check_Elab_Call (Prefix (N));
5066 Set_Etype (N, Etype (Nam));
5069 -- In the case where the call is to an overloaded subprogram, Analyze
5070 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5071 -- such a case Normalize_Actuals needs to be called once more to order
5072 -- the actuals correctly. Otherwise the call will have the ordering
5073 -- given by the last overloaded subprogram whether this is the correct
5074 -- one being called or not.
5076 if Is_Overloaded (Subp) then
5077 Normalize_Actuals (N, Nam, False, Norm_OK);
5078 pragma Assert (Norm_OK);
5081 -- In any case, call is fully resolved now. Reset Overload flag, to
5082 -- prevent subsequent overload resolution if node is analyzed again
5084 Set_Is_Overloaded (Subp, False);
5085 Set_Is_Overloaded (N, False);
5087 -- If we are calling the current subprogram from immediately within its
5088 -- body, then that is the case where we can sometimes detect cases of
5089 -- infinite recursion statically. Do not try this in case restriction
5090 -- No_Recursion is in effect anyway, and do it only for source calls.
5092 if Comes_From_Source (N) then
5093 Scop := Current_Scope;
5095 -- Issue warning for possible infinite recursion in the absence
5096 -- of the No_Recursion restriction.
5099 and then not Restriction_Active (No_Recursion)
5100 and then Check_Infinite_Recursion (N)
5102 -- Here we detected and flagged an infinite recursion, so we do
5103 -- not need to test the case below for further warnings. Also if
5104 -- we now have a raise SE node, we are all done.
5106 if Nkind (N) = N_Raise_Storage_Error then
5110 -- If call is to immediately containing subprogram, then check for
5111 -- the case of a possible run-time detectable infinite recursion.
5114 Scope_Loop : while Scop /= Standard_Standard loop
5117 -- Although in general case, recursion is not statically
5118 -- checkable, the case of calling an immediately containing
5119 -- subprogram is easy to catch.
5121 Check_Restriction (No_Recursion, N);
5123 -- If the recursive call is to a parameterless subprogram,
5124 -- then even if we can't statically detect infinite
5125 -- recursion, this is pretty suspicious, and we output a
5126 -- warning. Furthermore, we will try later to detect some
5127 -- cases here at run time by expanding checking code (see
5128 -- Detect_Infinite_Recursion in package Exp_Ch6).
5130 -- If the recursive call is within a handler, do not emit a
5131 -- warning, because this is a common idiom: loop until input
5132 -- is correct, catch illegal input in handler and restart.
5134 if No (First_Formal (Nam))
5135 and then Etype (Nam) = Standard_Void_Type
5136 and then not Error_Posted (N)
5137 and then Nkind (Parent (N)) /= N_Exception_Handler
5139 -- For the case of a procedure call. We give the message
5140 -- only if the call is the first statement in a sequence
5141 -- of statements, or if all previous statements are
5142 -- simple assignments. This is simply a heuristic to
5143 -- decrease false positives, without losing too many good
5144 -- warnings. The idea is that these previous statements
5145 -- may affect global variables the procedure depends on.
5147 if Nkind (N) = N_Procedure_Call_Statement
5148 and then Is_List_Member (N)
5154 while Present (P) loop
5155 if Nkind (P) /= N_Assignment_Statement then
5164 -- Do not give warning if we are in a conditional context
5167 K : constant Node_Kind := Nkind (Parent (N));
5169 if (K = N_Loop_Statement
5170 and then Present (Iteration_Scheme (Parent (N))))
5171 or else K = N_If_Statement
5172 or else K = N_Elsif_Part
5173 or else K = N_Case_Statement_Alternative
5179 -- Here warning is to be issued
5181 Set_Has_Recursive_Call (Nam);
5183 ("?possible infinite recursion!", N);
5185 ("\?Storage_Error may be raised at run time!", N);
5191 Scop := Scope (Scop);
5192 end loop Scope_Loop;
5196 -- If subprogram name is a predefined operator, it was given in
5197 -- functional notation. Replace call node with operator node, so
5198 -- that actuals can be resolved appropriately.
5200 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5201 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5204 elsif Present (Alias (Nam))
5205 and then Is_Predefined_Op (Alias (Nam))
5207 Resolve_Actuals (N, Nam);
5208 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5212 -- Create a transient scope if the resulting type requires it
5214 -- There are several notable exceptions:
5216 -- a) In init procs, the transient scope overhead is not needed, and is
5217 -- even incorrect when the call is a nested initialization call for a
5218 -- component whose expansion may generate adjust calls. However, if the
5219 -- call is some other procedure call within an initialization procedure
5220 -- (for example a call to Create_Task in the init_proc of the task
5221 -- run-time record) a transient scope must be created around this call.
5223 -- b) Enumeration literal pseudo-calls need no transient scope
5225 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5226 -- functions) do not use the secondary stack even though the return
5227 -- type may be unconstrained.
5229 -- d) Calls to a build-in-place function, since such functions may
5230 -- allocate their result directly in a target object, and cases where
5231 -- the result does get allocated in the secondary stack are checked for
5232 -- within the specialized Exp_Ch6 procedures for expanding those
5233 -- build-in-place calls.
5235 -- e) If the subprogram is marked Inline_Always, then even if it returns
5236 -- an unconstrained type the call does not require use of the secondary
5237 -- stack. However, inlining will only take place if the body to inline
5238 -- is already present. It may not be available if e.g. the subprogram is
5239 -- declared in a child instance.
5241 -- If this is an initialization call for a type whose construction
5242 -- uses the secondary stack, and it is not a nested call to initialize
5243 -- a component, we do need to create a transient scope for it. We
5244 -- check for this by traversing the type in Check_Initialization_Call.
5247 and then Has_Pragma_Inline_Always (Nam)
5248 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5249 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5253 elsif Ekind (Nam) = E_Enumeration_Literal
5254 or else Is_Build_In_Place_Function (Nam)
5255 or else Is_Intrinsic_Subprogram (Nam)
5259 elsif Expander_Active
5260 and then Is_Type (Etype (Nam))
5261 and then Requires_Transient_Scope (Etype (Nam))
5263 (not Within_Init_Proc
5265 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5267 Establish_Transient_Scope (N, Sec_Stack => True);
5269 -- If the call appears within the bounds of a loop, it will
5270 -- be rewritten and reanalyzed, nothing left to do here.
5272 if Nkind (N) /= N_Function_Call then
5276 elsif Is_Init_Proc (Nam)
5277 and then not Within_Init_Proc
5279 Check_Initialization_Call (N, Nam);
5282 -- A protected function cannot be called within the definition of the
5283 -- enclosing protected type.
5285 if Is_Protected_Type (Scope (Nam))
5286 and then In_Open_Scopes (Scope (Nam))
5287 and then not Has_Completion (Scope (Nam))
5290 ("& cannot be called before end of protected definition", N, Nam);
5293 -- Propagate interpretation to actuals, and add default expressions
5296 if Present (First_Formal (Nam)) then
5297 Resolve_Actuals (N, Nam);
5299 -- Overloaded literals are rewritten as function calls, for purpose of
5300 -- resolution. After resolution, we can replace the call with the
5303 elsif Ekind (Nam) = E_Enumeration_Literal then
5304 Copy_Node (Subp, N);
5305 Resolve_Entity_Name (N, Typ);
5307 -- Avoid validation, since it is a static function call
5309 Generate_Reference (Nam, Subp);
5313 -- If the subprogram is not global, then kill all saved values and
5314 -- checks. This is a bit conservative, since in many cases we could do
5315 -- better, but it is not worth the effort. Similarly, we kill constant
5316 -- values. However we do not need to do this for internal entities
5317 -- (unless they are inherited user-defined subprograms), since they
5318 -- are not in the business of molesting local values.
5320 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5321 -- kill all checks and values for calls to global subprograms. This
5322 -- takes care of the case where an access to a local subprogram is
5323 -- taken, and could be passed directly or indirectly and then called
5324 -- from almost any context.
5326 -- Note: we do not do this step till after resolving the actuals. That
5327 -- way we still take advantage of the current value information while
5328 -- scanning the actuals.
5330 -- We suppress killing values if we are processing the nodes associated
5331 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5332 -- type kills all the values as part of analyzing the code that
5333 -- initializes the dispatch tables.
5335 if Inside_Freezing_Actions = 0
5336 and then (not Is_Library_Level_Entity (Nam)
5337 or else Suppress_Value_Tracking_On_Call
5338 (Nearest_Dynamic_Scope (Current_Scope)))
5339 and then (Comes_From_Source (Nam)
5340 or else (Present (Alias (Nam))
5341 and then Comes_From_Source (Alias (Nam))))
5343 Kill_Current_Values;
5346 -- If we are warning about unread OUT parameters, this is the place to
5347 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5348 -- after the above call to Kill_Current_Values (since that call clears
5349 -- the Last_Assignment field of all local variables).
5351 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5352 and then Comes_From_Source (N)
5353 and then In_Extended_Main_Source_Unit (N)
5360 F := First_Formal (Nam);
5361 A := First_Actual (N);
5362 while Present (F) and then Present (A) loop
5363 if (Ekind (F) = E_Out_Parameter
5365 Ekind (F) = E_In_Out_Parameter)
5366 and then Warn_On_Modified_As_Out_Parameter (F)
5367 and then Is_Entity_Name (A)
5368 and then Present (Entity (A))
5369 and then Comes_From_Source (N)
5370 and then Safe_To_Capture_Value (N, Entity (A))
5372 Set_Last_Assignment (Entity (A), A);
5381 -- If the subprogram is a primitive operation, check whether or not
5382 -- it is a correct dispatching call.
5384 if Is_Overloadable (Nam)
5385 and then Is_Dispatching_Operation (Nam)
5387 Check_Dispatching_Call (N);
5389 elsif Ekind (Nam) /= E_Subprogram_Type
5390 and then Is_Abstract_Subprogram (Nam)
5391 and then not In_Instance
5393 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5396 -- If this is a dispatching call, generate the appropriate reference,
5397 -- for better source navigation in GPS.
5399 if Is_Overloadable (Nam)
5400 and then Present (Controlling_Argument (N))
5402 Generate_Reference (Nam, Subp, 'R');
5404 -- Normal case, not a dispatching call
5407 Generate_Reference (Nam, Subp);
5410 if Is_Intrinsic_Subprogram (Nam) then
5411 Check_Intrinsic_Call (N);
5414 -- Check for violation of restriction No_Specific_Termination_Handlers
5415 -- and warn on a potentially blocking call to Abort_Task.
5417 if Is_RTE (Nam, RE_Set_Specific_Handler)
5419 Is_RTE (Nam, RE_Specific_Handler)
5421 Check_Restriction (No_Specific_Termination_Handlers, N);
5423 elsif Is_RTE (Nam, RE_Abort_Task) then
5424 Check_Potentially_Blocking_Operation (N);
5427 -- Issue an error for a call to an eliminated subprogram
5429 Check_For_Eliminated_Subprogram (Subp, Nam);
5431 -- All done, evaluate call and deal with elaboration issues
5434 Check_Elab_Call (N);
5435 Warn_On_Overlapping_Actuals (Nam, N);
5438 -------------------------------
5439 -- Resolve_Character_Literal --
5440 -------------------------------
5442 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5443 B_Typ : constant Entity_Id := Base_Type (Typ);
5447 -- Verify that the character does belong to the type of the context
5449 Set_Etype (N, B_Typ);
5450 Eval_Character_Literal (N);
5452 -- Wide_Wide_Character literals must always be defined, since the set
5453 -- of wide wide character literals is complete, i.e. if a character
5454 -- literal is accepted by the parser, then it is OK for wide wide
5455 -- character (out of range character literals are rejected).
5457 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5460 -- Always accept character literal for type Any_Character, which
5461 -- occurs in error situations and in comparisons of literals, both
5462 -- of which should accept all literals.
5464 elsif B_Typ = Any_Character then
5467 -- For Standard.Character or a type derived from it, check that
5468 -- the literal is in range
5470 elsif Root_Type (B_Typ) = Standard_Character then
5471 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5475 -- For Standard.Wide_Character or a type derived from it, check
5476 -- that the literal is in range
5478 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5479 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5483 -- For Standard.Wide_Wide_Character or a type derived from it, we
5484 -- know the literal is in range, since the parser checked!
5486 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5489 -- If the entity is already set, this has already been resolved in a
5490 -- generic context, or comes from expansion. Nothing else to do.
5492 elsif Present (Entity (N)) then
5495 -- Otherwise we have a user defined character type, and we can use the
5496 -- standard visibility mechanisms to locate the referenced entity.
5499 C := Current_Entity (N);
5500 while Present (C) loop
5501 if Etype (C) = B_Typ then
5502 Set_Entity_With_Style_Check (N, C);
5503 Generate_Reference (C, N);
5511 -- If we fall through, then the literal does not match any of the
5512 -- entries of the enumeration type. This isn't just a constraint
5513 -- error situation, it is an illegality (see RM 4.2).
5516 ("character not defined for }", N, First_Subtype (B_Typ));
5517 end Resolve_Character_Literal;
5519 ---------------------------
5520 -- Resolve_Comparison_Op --
5521 ---------------------------
5523 -- Context requires a boolean type, and plays no role in resolution.
5524 -- Processing identical to that for equality operators. The result
5525 -- type is the base type, which matters when pathological subtypes of
5526 -- booleans with limited ranges are used.
5528 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5529 L : constant Node_Id := Left_Opnd (N);
5530 R : constant Node_Id := Right_Opnd (N);
5534 -- If this is an intrinsic operation which is not predefined, use the
5535 -- types of its declared arguments to resolve the possibly overloaded
5536 -- operands. Otherwise the operands are unambiguous and specify the
5539 if Scope (Entity (N)) /= Standard_Standard then
5540 T := Etype (First_Entity (Entity (N)));
5543 T := Find_Unique_Type (L, R);
5545 if T = Any_Fixed then
5546 T := Unique_Fixed_Point_Type (L);
5550 Set_Etype (N, Base_Type (Typ));
5551 Generate_Reference (T, N, ' ');
5553 if T /= Any_Type then
5554 if T = Any_String or else
5555 T = Any_Composite or else
5558 if T = Any_Character then
5559 Ambiguous_Character (L);
5561 Error_Msg_N ("ambiguous operands for comparison", N);
5564 Set_Etype (N, Any_Type);
5570 Check_Unset_Reference (L);
5571 Check_Unset_Reference (R);
5572 Generate_Operator_Reference (N, T);
5573 Check_Low_Bound_Tested (N);
5574 Eval_Relational_Op (N);
5577 end Resolve_Comparison_Op;
5579 ------------------------------------
5580 -- Resolve_Conditional_Expression --
5581 ------------------------------------
5583 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5584 Condition : constant Node_Id := First (Expressions (N));
5585 Then_Expr : constant Node_Id := Next (Condition);
5586 Else_Expr : Node_Id := Next (Then_Expr);
5589 Resolve (Condition, Any_Boolean);
5590 Resolve (Then_Expr, Typ);
5592 -- If ELSE expression present, just resolve using the determined type
5594 if Present (Else_Expr) then
5595 Resolve (Else_Expr, Typ);
5597 -- If no ELSE expression is present, root type must be Standard.Boolean
5598 -- and we provide a Standard.True result converted to the appropriate
5599 -- Boolean type (in case it is a derived boolean type).
5601 elsif Root_Type (Typ) = Standard_Boolean then
5603 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5604 Analyze_And_Resolve (Else_Expr, Typ);
5605 Append_To (Expressions (N), Else_Expr);
5608 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5609 Append_To (Expressions (N), Error);
5613 Eval_Conditional_Expression (N);
5614 end Resolve_Conditional_Expression;
5616 -----------------------------------------
5617 -- Resolve_Discrete_Subtype_Indication --
5618 -----------------------------------------
5620 procedure Resolve_Discrete_Subtype_Indication
5628 Analyze (Subtype_Mark (N));
5629 S := Entity (Subtype_Mark (N));
5631 if Nkind (Constraint (N)) /= N_Range_Constraint then
5632 Error_Msg_N ("expect range constraint for discrete type", N);
5633 Set_Etype (N, Any_Type);
5636 R := Range_Expression (Constraint (N));
5644 if Base_Type (S) /= Base_Type (Typ) then
5646 ("expect subtype of }", N, First_Subtype (Typ));
5648 -- Rewrite the constraint as a range of Typ
5649 -- to allow compilation to proceed further.
5652 Rewrite (Low_Bound (R),
5653 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5654 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5655 Attribute_Name => Name_First));
5656 Rewrite (High_Bound (R),
5657 Make_Attribute_Reference (Sloc (High_Bound (R)),
5658 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5659 Attribute_Name => Name_First));
5663 Set_Etype (N, Etype (R));
5665 -- Additionally, we must check that the bounds are compatible
5666 -- with the given subtype, which might be different from the
5667 -- type of the context.
5669 Apply_Range_Check (R, S);
5671 -- ??? If the above check statically detects a Constraint_Error
5672 -- it replaces the offending bound(s) of the range R with a
5673 -- Constraint_Error node. When the itype which uses these bounds
5674 -- is frozen the resulting call to Duplicate_Subexpr generates
5675 -- a new temporary for the bounds.
5677 -- Unfortunately there are other itypes that are also made depend
5678 -- on these bounds, so when Duplicate_Subexpr is called they get
5679 -- a forward reference to the newly created temporaries and Gigi
5680 -- aborts on such forward references. This is probably sign of a
5681 -- more fundamental problem somewhere else in either the order of
5682 -- itype freezing or the way certain itypes are constructed.
5684 -- To get around this problem we call Remove_Side_Effects right
5685 -- away if either bounds of R are a Constraint_Error.
5688 L : constant Node_Id := Low_Bound (R);
5689 H : constant Node_Id := High_Bound (R);
5692 if Nkind (L) = N_Raise_Constraint_Error then
5693 Remove_Side_Effects (L);
5696 if Nkind (H) = N_Raise_Constraint_Error then
5697 Remove_Side_Effects (H);
5701 Check_Unset_Reference (Low_Bound (R));
5702 Check_Unset_Reference (High_Bound (R));
5705 end Resolve_Discrete_Subtype_Indication;
5707 -------------------------
5708 -- Resolve_Entity_Name --
5709 -------------------------
5711 -- Used to resolve identifiers and expanded names
5713 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5714 E : constant Entity_Id := Entity (N);
5717 -- If garbage from errors, set to Any_Type and return
5719 if No (E) and then Total_Errors_Detected /= 0 then
5720 Set_Etype (N, Any_Type);
5724 -- Replace named numbers by corresponding literals. Note that this is
5725 -- the one case where Resolve_Entity_Name must reset the Etype, since
5726 -- it is currently marked as universal.
5728 if Ekind (E) = E_Named_Integer then
5730 Eval_Named_Integer (N);
5732 elsif Ekind (E) = E_Named_Real then
5734 Eval_Named_Real (N);
5736 -- Allow use of subtype only if it is a concurrent type where we are
5737 -- currently inside the body. This will eventually be expanded into a
5738 -- call to Self (for tasks) or _object (for protected objects). Any
5739 -- other use of a subtype is invalid.
5741 elsif Is_Type (E) then
5742 if Is_Concurrent_Type (E)
5743 and then In_Open_Scopes (E)
5748 ("invalid use of subtype mark in expression or call", N);
5751 -- Check discriminant use if entity is discriminant in current scope,
5752 -- i.e. discriminant of record or concurrent type currently being
5753 -- analyzed. Uses in corresponding body are unrestricted.
5755 elsif Ekind (E) = E_Discriminant
5756 and then Scope (E) = Current_Scope
5757 and then not Has_Completion (Current_Scope)
5759 Check_Discriminant_Use (N);
5761 -- A parameterless generic function cannot appear in a context that
5762 -- requires resolution.
5764 elsif Ekind (E) = E_Generic_Function then
5765 Error_Msg_N ("illegal use of generic function", N);
5767 elsif Ekind (E) = E_Out_Parameter
5768 and then Ada_Version = Ada_83
5769 and then (Nkind (Parent (N)) in N_Op
5770 or else (Nkind (Parent (N)) = N_Assignment_Statement
5771 and then N = Expression (Parent (N)))
5772 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5774 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5776 -- In all other cases, just do the possible static evaluation
5779 -- A deferred constant that appears in an expression must have a
5780 -- completion, unless it has been removed by in-place expansion of
5783 if Ekind (E) = E_Constant
5784 and then Comes_From_Source (E)
5785 and then No (Constant_Value (E))
5786 and then Is_Frozen (Etype (E))
5787 and then not In_Spec_Expression
5788 and then not Is_Imported (E)
5791 if No_Initialization (Parent (E))
5792 or else (Present (Full_View (E))
5793 and then No_Initialization (Parent (Full_View (E))))
5798 "deferred constant is frozen before completion", N);
5802 Eval_Entity_Name (N);
5804 end Resolve_Entity_Name;
5810 procedure Resolve_Entry (Entry_Name : Node_Id) is
5811 Loc : constant Source_Ptr := Sloc (Entry_Name);
5819 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5820 -- If the bounds of the entry family being called depend on task
5821 -- discriminants, build a new index subtype where a discriminant is
5822 -- replaced with the value of the discriminant of the target task.
5823 -- The target task is the prefix of the entry name in the call.
5825 -----------------------
5826 -- Actual_Index_Type --
5827 -----------------------
5829 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5830 Typ : constant Entity_Id := Entry_Index_Type (E);
5831 Tsk : constant Entity_Id := Scope (E);
5832 Lo : constant Node_Id := Type_Low_Bound (Typ);
5833 Hi : constant Node_Id := Type_High_Bound (Typ);
5836 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5837 -- If the bound is given by a discriminant, replace with a reference
5838 -- to the discriminant of the same name in the target task. If the
5839 -- entry name is the target of a requeue statement and the entry is
5840 -- in the current protected object, the bound to be used is the
5841 -- discriminal of the object (see apply_range_checks for details of
5842 -- the transformation).
5844 -----------------------------
5845 -- Actual_Discriminant_Ref --
5846 -----------------------------
5848 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5849 Typ : constant Entity_Id := Etype (Bound);
5853 Remove_Side_Effects (Bound);
5855 if not Is_Entity_Name (Bound)
5856 or else Ekind (Entity (Bound)) /= E_Discriminant
5860 elsif Is_Protected_Type (Tsk)
5861 and then In_Open_Scopes (Tsk)
5862 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5864 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5868 Make_Selected_Component (Loc,
5869 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5870 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5875 end Actual_Discriminant_Ref;
5877 -- Start of processing for Actual_Index_Type
5880 if not Has_Discriminants (Tsk)
5881 or else (not Is_Entity_Name (Lo)
5883 not Is_Entity_Name (Hi))
5885 return Entry_Index_Type (E);
5888 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5889 Set_Etype (New_T, Base_Type (Typ));
5890 Set_Size_Info (New_T, Typ);
5891 Set_RM_Size (New_T, RM_Size (Typ));
5892 Set_Scalar_Range (New_T,
5893 Make_Range (Sloc (Entry_Name),
5894 Low_Bound => Actual_Discriminant_Ref (Lo),
5895 High_Bound => Actual_Discriminant_Ref (Hi)));
5899 end Actual_Index_Type;
5901 -- Start of processing of Resolve_Entry
5904 -- Find name of entry being called, and resolve prefix of name
5905 -- with its own type. The prefix can be overloaded, and the name
5906 -- and signature of the entry must be taken into account.
5908 if Nkind (Entry_Name) = N_Indexed_Component then
5910 -- Case of dealing with entry family within the current tasks
5912 E_Name := Prefix (Entry_Name);
5915 E_Name := Entry_Name;
5918 if Is_Entity_Name (E_Name) then
5920 -- Entry call to an entry (or entry family) in the current task. This
5921 -- is legal even though the task will deadlock. Rewrite as call to
5924 -- This can also be a call to an entry in an enclosing task. If this
5925 -- is a single task, we have to retrieve its name, because the scope
5926 -- of the entry is the task type, not the object. If the enclosing
5927 -- task is a task type, the identity of the task is given by its own
5930 -- Finally this can be a requeue on an entry of the same task or
5931 -- protected object.
5933 S := Scope (Entity (E_Name));
5935 for J in reverse 0 .. Scope_Stack.Last loop
5936 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5937 and then not Comes_From_Source (S)
5939 -- S is an enclosing task or protected object. The concurrent
5940 -- declaration has been converted into a type declaration, and
5941 -- the object itself has an object declaration that follows
5942 -- the type in the same declarative part.
5944 Tsk := Next_Entity (S);
5945 while Etype (Tsk) /= S loop
5952 elsif S = Scope_Stack.Table (J).Entity then
5954 -- Call to current task. Will be transformed into call to Self
5962 Make_Selected_Component (Loc,
5963 Prefix => New_Occurrence_Of (S, Loc),
5965 New_Occurrence_Of (Entity (E_Name), Loc));
5966 Rewrite (E_Name, New_N);
5969 elsif Nkind (Entry_Name) = N_Selected_Component
5970 and then Is_Overloaded (Prefix (Entry_Name))
5972 -- Use the entry name (which must be unique at this point) to find
5973 -- the prefix that returns the corresponding task type or protected
5977 Pref : constant Node_Id := Prefix (Entry_Name);
5978 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5983 Get_First_Interp (Pref, I, It);
5984 while Present (It.Typ) loop
5985 if Scope (Ent) = It.Typ then
5986 Set_Etype (Pref, It.Typ);
5990 Get_Next_Interp (I, It);
5995 if Nkind (Entry_Name) = N_Selected_Component then
5996 Resolve (Prefix (Entry_Name));
5998 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5999 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6000 Resolve (Prefix (Prefix (Entry_Name)));
6001 Index := First (Expressions (Entry_Name));
6002 Resolve (Index, Entry_Index_Type (Nam));
6004 -- Up to this point the expression could have been the actual in a
6005 -- simple entry call, and be given by a named association.
6007 if Nkind (Index) = N_Parameter_Association then
6008 Error_Msg_N ("expect expression for entry index", Index);
6010 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6015 ------------------------
6016 -- Resolve_Entry_Call --
6017 ------------------------
6019 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6020 Entry_Name : constant Node_Id := Name (N);
6021 Loc : constant Source_Ptr := Sloc (Entry_Name);
6023 First_Named : Node_Id;
6030 -- We kill all checks here, because it does not seem worth the effort to
6031 -- do anything better, an entry call is a big operation.
6035 -- Processing of the name is similar for entry calls and protected
6036 -- operation calls. Once the entity is determined, we can complete
6037 -- the resolution of the actuals.
6039 -- The selector may be overloaded, in the case of a protected object
6040 -- with overloaded functions. The type of the context is used for
6043 if Nkind (Entry_Name) = N_Selected_Component
6044 and then Is_Overloaded (Selector_Name (Entry_Name))
6045 and then Typ /= Standard_Void_Type
6052 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6053 while Present (It.Typ) loop
6054 if Covers (Typ, It.Typ) then
6055 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6056 Set_Etype (Entry_Name, It.Typ);
6058 Generate_Reference (It.Typ, N, ' ');
6061 Get_Next_Interp (I, It);
6066 Resolve_Entry (Entry_Name);
6068 if Nkind (Entry_Name) = N_Selected_Component then
6070 -- Simple entry call
6072 Nam := Entity (Selector_Name (Entry_Name));
6073 Obj := Prefix (Entry_Name);
6074 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6076 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6078 -- Call to member of entry family
6080 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6081 Obj := Prefix (Prefix (Entry_Name));
6082 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6085 -- We cannot in general check the maximum depth of protected entry
6086 -- calls at compile time. But we can tell that any protected entry
6087 -- call at all violates a specified nesting depth of zero.
6089 if Is_Protected_Type (Scope (Nam)) then
6090 Check_Restriction (Max_Entry_Queue_Length, N);
6093 -- Use context type to disambiguate a protected function that can be
6094 -- called without actuals and that returns an array type, and where
6095 -- the argument list may be an indexing of the returned value.
6097 if Ekind (Nam) = E_Function
6098 and then Needs_No_Actuals (Nam)
6099 and then Present (Parameter_Associations (N))
6101 ((Is_Array_Type (Etype (Nam))
6102 and then Covers (Typ, Component_Type (Etype (Nam))))
6104 or else (Is_Access_Type (Etype (Nam))
6105 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6106 and then Covers (Typ,
6107 Component_Type (Designated_Type (Etype (Nam))))))
6110 Index_Node : Node_Id;
6114 Make_Indexed_Component (Loc,
6116 Make_Function_Call (Loc,
6117 Name => Relocate_Node (Entry_Name)),
6118 Expressions => Parameter_Associations (N));
6120 -- Since we are correcting a node classification error made by
6121 -- the parser, we call Replace rather than Rewrite.
6123 Replace (N, Index_Node);
6124 Set_Etype (Prefix (N), Etype (Nam));
6126 Resolve_Indexed_Component (N, Typ);
6131 -- The operation name may have been overloaded. Order the actuals
6132 -- according to the formals of the resolved entity, and set the
6133 -- return type to that of the operation.
6136 Normalize_Actuals (N, Nam, False, Norm_OK);
6137 pragma Assert (Norm_OK);
6138 Set_Etype (N, Etype (Nam));
6141 Resolve_Actuals (N, Nam);
6142 Generate_Reference (Nam, Entry_Name);
6144 if Ekind (Nam) = E_Entry
6145 or else Ekind (Nam) = E_Entry_Family
6147 Check_Potentially_Blocking_Operation (N);
6150 -- Verify that a procedure call cannot masquerade as an entry
6151 -- call where an entry call is expected.
6153 if Ekind (Nam) = E_Procedure then
6154 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6155 and then N = Entry_Call_Statement (Parent (N))
6157 Error_Msg_N ("entry call required in select statement", N);
6159 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6160 and then N = Triggering_Statement (Parent (N))
6162 Error_Msg_N ("triggering statement cannot be procedure call", N);
6164 elsif Ekind (Scope (Nam)) = E_Task_Type
6165 and then not In_Open_Scopes (Scope (Nam))
6167 Error_Msg_N ("task has no entry with this name", Entry_Name);
6171 -- After resolution, entry calls and protected procedure calls are
6172 -- changed into entry calls, for expansion. The structure of the node
6173 -- does not change, so it can safely be done in place. Protected
6174 -- function calls must keep their structure because they are
6177 if Ekind (Nam) /= E_Function then
6179 -- A protected operation that is not a function may modify the
6180 -- corresponding object, and cannot apply to a constant. If this
6181 -- is an internal call, the prefix is the type itself.
6183 if Is_Protected_Type (Scope (Nam))
6184 and then not Is_Variable (Obj)
6185 and then (not Is_Entity_Name (Obj)
6186 or else not Is_Type (Entity (Obj)))
6189 ("prefix of protected procedure or entry call must be variable",
6193 Actuals := Parameter_Associations (N);
6194 First_Named := First_Named_Actual (N);
6197 Make_Entry_Call_Statement (Loc,
6199 Parameter_Associations => Actuals));
6201 Set_First_Named_Actual (N, First_Named);
6202 Set_Analyzed (N, True);
6204 -- Protected functions can return on the secondary stack, in which
6205 -- case we must trigger the transient scope mechanism.
6207 elsif Expander_Active
6208 and then Requires_Transient_Scope (Etype (Nam))
6210 Establish_Transient_Scope (N, Sec_Stack => True);
6212 end Resolve_Entry_Call;
6214 -------------------------
6215 -- Resolve_Equality_Op --
6216 -------------------------
6218 -- Both arguments must have the same type, and the boolean context does
6219 -- not participate in the resolution. The first pass verifies that the
6220 -- interpretation is not ambiguous, and the type of the left argument is
6221 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6222 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6223 -- though they carry a single (universal) type. Diagnose this case here.
6225 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6226 L : constant Node_Id := Left_Opnd (N);
6227 R : constant Node_Id := Right_Opnd (N);
6228 T : Entity_Id := Find_Unique_Type (L, R);
6230 function Find_Unique_Access_Type return Entity_Id;
6231 -- In the case of allocators, make a last-ditch attempt to find a single
6232 -- access type with the right designated type. This is semantically
6233 -- dubious, and of no interest to any real code, but c48008a makes it
6236 -----------------------------
6237 -- Find_Unique_Access_Type --
6238 -----------------------------
6240 function Find_Unique_Access_Type return Entity_Id is
6246 if Ekind (Etype (R)) = E_Allocator_Type then
6247 Acc := Designated_Type (Etype (R));
6248 elsif Ekind (Etype (L)) = E_Allocator_Type then
6249 Acc := Designated_Type (Etype (L));
6255 while S /= Standard_Standard loop
6256 E := First_Entity (S);
6257 while Present (E) loop
6259 and then Is_Access_Type (E)
6260 and then Ekind (E) /= E_Allocator_Type
6261 and then Designated_Type (E) = Base_Type (Acc)
6273 end Find_Unique_Access_Type;
6275 -- Start of processing for Resolve_Equality_Op
6278 Set_Etype (N, Base_Type (Typ));
6279 Generate_Reference (T, N, ' ');
6281 if T = Any_Fixed then
6282 T := Unique_Fixed_Point_Type (L);
6285 if T /= Any_Type then
6287 or else T = Any_Composite
6288 or else T = Any_Character
6290 if T = Any_Character then
6291 Ambiguous_Character (L);
6293 Error_Msg_N ("ambiguous operands for equality", N);
6296 Set_Etype (N, Any_Type);
6299 elsif T = Any_Access
6300 or else Ekind (T) = E_Allocator_Type
6301 or else Ekind (T) = E_Access_Attribute_Type
6303 T := Find_Unique_Access_Type;
6306 Error_Msg_N ("ambiguous operands for equality", N);
6307 Set_Etype (N, Any_Type);
6315 -- If the unique type is a class-wide type then it will be expanded
6316 -- into a dispatching call to the predefined primitive. Therefore we
6317 -- check here for potential violation of such restriction.
6319 if Is_Class_Wide_Type (T) then
6320 Check_Restriction (No_Dispatching_Calls, N);
6323 if Warn_On_Redundant_Constructs
6324 and then Comes_From_Source (N)
6325 and then Is_Entity_Name (R)
6326 and then Entity (R) = Standard_True
6327 and then Comes_From_Source (R)
6329 Error_Msg_N ("?comparison with True is redundant!", R);
6332 Check_Unset_Reference (L);
6333 Check_Unset_Reference (R);
6334 Generate_Operator_Reference (N, T);
6335 Check_Low_Bound_Tested (N);
6337 -- If this is an inequality, it may be the implicit inequality
6338 -- created for a user-defined operation, in which case the corres-
6339 -- ponding equality operation is not intrinsic, and the operation
6340 -- cannot be constant-folded. Else fold.
6342 if Nkind (N) = N_Op_Eq
6343 or else Comes_From_Source (Entity (N))
6344 or else Ekind (Entity (N)) = E_Operator
6345 or else Is_Intrinsic_Subprogram
6346 (Corresponding_Equality (Entity (N)))
6348 Eval_Relational_Op (N);
6350 elsif Nkind (N) = N_Op_Ne
6351 and then Is_Abstract_Subprogram (Entity (N))
6353 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6356 -- Ada 2005: If one operand is an anonymous access type, convert the
6357 -- other operand to it, to ensure that the underlying types match in
6358 -- the back-end. Same for access_to_subprogram, and the conversion
6359 -- verifies that the types are subtype conformant.
6361 -- We apply the same conversion in the case one of the operands is a
6362 -- private subtype of the type of the other.
6364 -- Why the Expander_Active test here ???
6368 (Ekind (T) = E_Anonymous_Access_Type
6369 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6370 or else Is_Private_Type (T))
6372 if Etype (L) /= T then
6374 Make_Unchecked_Type_Conversion (Sloc (L),
6375 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6376 Expression => Relocate_Node (L)));
6377 Analyze_And_Resolve (L, T);
6380 if (Etype (R)) /= T then
6382 Make_Unchecked_Type_Conversion (Sloc (R),
6383 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6384 Expression => Relocate_Node (R)));
6385 Analyze_And_Resolve (R, T);
6389 end Resolve_Equality_Op;
6391 ----------------------------------
6392 -- Resolve_Explicit_Dereference --
6393 ----------------------------------
6395 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6396 Loc : constant Source_Ptr := Sloc (N);
6398 P : constant Node_Id := Prefix (N);
6403 Check_Fully_Declared_Prefix (Typ, P);
6405 if Is_Overloaded (P) then
6407 -- Use the context type to select the prefix that has the correct
6410 Get_First_Interp (P, I, It);
6411 while Present (It.Typ) loop
6412 exit when Is_Access_Type (It.Typ)
6413 and then Covers (Typ, Designated_Type (It.Typ));
6414 Get_Next_Interp (I, It);
6417 if Present (It.Typ) then
6418 Resolve (P, It.Typ);
6420 -- If no interpretation covers the designated type of the prefix,
6421 -- this is the pathological case where not all implementations of
6422 -- the prefix allow the interpretation of the node as a call. Now
6423 -- that the expected type is known, Remove other interpretations
6424 -- from prefix, rewrite it as a call, and resolve again, so that
6425 -- the proper call node is generated.
6427 Get_First_Interp (P, I, It);
6428 while Present (It.Typ) loop
6429 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6433 Get_Next_Interp (I, It);
6437 Make_Function_Call (Loc,
6439 Make_Explicit_Dereference (Loc,
6441 Parameter_Associations => New_List);
6443 Save_Interps (N, New_N);
6445 Analyze_And_Resolve (N, Typ);
6449 Set_Etype (N, Designated_Type (It.Typ));
6455 if Is_Access_Type (Etype (P)) then
6456 Apply_Access_Check (N);
6459 -- If the designated type is a packed unconstrained array type, and the
6460 -- explicit dereference is not in the context of an attribute reference,
6461 -- then we must compute and set the actual subtype, since it is needed
6462 -- by Gigi. The reason we exclude the attribute case is that this is
6463 -- handled fine by Gigi, and in fact we use such attributes to build the
6464 -- actual subtype. We also exclude generated code (which builds actual
6465 -- subtypes directly if they are needed).
6467 if Is_Array_Type (Etype (N))
6468 and then Is_Packed (Etype (N))
6469 and then not Is_Constrained (Etype (N))
6470 and then Nkind (Parent (N)) /= N_Attribute_Reference
6471 and then Comes_From_Source (N)
6473 Set_Etype (N, Get_Actual_Subtype (N));
6476 -- Note: No Eval processing is required for an explicit dereference,
6477 -- because such a name can never be static.
6479 end Resolve_Explicit_Dereference;
6481 -------------------------------
6482 -- Resolve_Indexed_Component --
6483 -------------------------------
6485 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6486 Name : constant Node_Id := Prefix (N);
6488 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6492 if Is_Overloaded (Name) then
6494 -- Use the context type to select the prefix that yields the correct
6500 I1 : Interp_Index := 0;
6501 P : constant Node_Id := Prefix (N);
6502 Found : Boolean := False;
6505 Get_First_Interp (P, I, It);
6506 while Present (It.Typ) loop
6507 if (Is_Array_Type (It.Typ)
6508 and then Covers (Typ, Component_Type (It.Typ)))
6509 or else (Is_Access_Type (It.Typ)
6510 and then Is_Array_Type (Designated_Type (It.Typ))
6512 (Typ, Component_Type (Designated_Type (It.Typ))))
6515 It := Disambiguate (P, I1, I, Any_Type);
6517 if It = No_Interp then
6518 Error_Msg_N ("ambiguous prefix for indexing", N);
6524 Array_Type := It.Typ;
6530 Array_Type := It.Typ;
6535 Get_Next_Interp (I, It);
6540 Array_Type := Etype (Name);
6543 Resolve (Name, Array_Type);
6544 Array_Type := Get_Actual_Subtype_If_Available (Name);
6546 -- If prefix is access type, dereference to get real array type.
6547 -- Note: we do not apply an access check because the expander always
6548 -- introduces an explicit dereference, and the check will happen there.
6550 if Is_Access_Type (Array_Type) then
6551 Array_Type := Designated_Type (Array_Type);
6554 -- If name was overloaded, set component type correctly now
6555 -- If a misplaced call to an entry family (which has no index types)
6556 -- return. Error will be diagnosed from calling context.
6558 if Is_Array_Type (Array_Type) then
6559 Set_Etype (N, Component_Type (Array_Type));
6564 Index := First_Index (Array_Type);
6565 Expr := First (Expressions (N));
6567 -- The prefix may have resolved to a string literal, in which case its
6568 -- etype has a special representation. This is only possible currently
6569 -- if the prefix is a static concatenation, written in functional
6572 if Ekind (Array_Type) = E_String_Literal_Subtype then
6573 Resolve (Expr, Standard_Positive);
6576 while Present (Index) and Present (Expr) loop
6577 Resolve (Expr, Etype (Index));
6578 Check_Unset_Reference (Expr);
6580 if Is_Scalar_Type (Etype (Expr)) then
6581 Apply_Scalar_Range_Check (Expr, Etype (Index));
6583 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6591 -- Do not generate the warning on suspicious index if we are analyzing
6592 -- package Ada.Tags; otherwise we will report the warning with the
6593 -- Prims_Ptr field of the dispatch table.
6595 if Scope (Etype (Prefix (N))) = Standard_Standard
6597 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6600 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6601 Eval_Indexed_Component (N);
6603 end Resolve_Indexed_Component;
6605 -----------------------------
6606 -- Resolve_Integer_Literal --
6607 -----------------------------
6609 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6612 Eval_Integer_Literal (N);
6613 end Resolve_Integer_Literal;
6615 --------------------------------
6616 -- Resolve_Intrinsic_Operator --
6617 --------------------------------
6619 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6620 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6627 while Scope (Op) /= Standard_Standard loop
6629 pragma Assert (Present (Op));
6633 Set_Is_Overloaded (N, False);
6635 -- If the operand type is private, rewrite with suitable conversions on
6636 -- the operands and the result, to expose the proper underlying numeric
6639 if Is_Private_Type (Typ) then
6640 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6642 if Nkind (N) = N_Op_Expon then
6643 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6645 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6648 Save_Interps (Left_Opnd (N), Expression (Arg1));
6649 Save_Interps (Right_Opnd (N), Expression (Arg2));
6651 Set_Left_Opnd (N, Arg1);
6652 Set_Right_Opnd (N, Arg2);
6654 Set_Etype (N, Btyp);
6655 Rewrite (N, Unchecked_Convert_To (Typ, N));
6658 elsif Typ /= Etype (Left_Opnd (N))
6659 or else Typ /= Etype (Right_Opnd (N))
6661 -- Add explicit conversion where needed, and save interpretations in
6662 -- case operands are overloaded.
6664 Arg1 := Convert_To (Typ, Left_Opnd (N));
6665 Arg2 := Convert_To (Typ, Right_Opnd (N));
6667 if Nkind (Arg1) = N_Type_Conversion then
6668 Save_Interps (Left_Opnd (N), Expression (Arg1));
6670 Save_Interps (Left_Opnd (N), Arg1);
6673 if Nkind (Arg2) = N_Type_Conversion then
6674 Save_Interps (Right_Opnd (N), Expression (Arg2));
6676 Save_Interps (Right_Opnd (N), Arg2);
6679 Rewrite (Left_Opnd (N), Arg1);
6680 Rewrite (Right_Opnd (N), Arg2);
6683 Resolve_Arithmetic_Op (N, Typ);
6686 Resolve_Arithmetic_Op (N, Typ);
6688 end Resolve_Intrinsic_Operator;
6690 --------------------------------------
6691 -- Resolve_Intrinsic_Unary_Operator --
6692 --------------------------------------
6694 procedure Resolve_Intrinsic_Unary_Operator
6698 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6704 while Scope (Op) /= Standard_Standard loop
6706 pragma Assert (Present (Op));
6711 if Is_Private_Type (Typ) then
6712 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6713 Save_Interps (Right_Opnd (N), Expression (Arg2));
6715 Set_Right_Opnd (N, Arg2);
6717 Set_Etype (N, Btyp);
6718 Rewrite (N, Unchecked_Convert_To (Typ, N));
6722 Resolve_Unary_Op (N, Typ);
6724 end Resolve_Intrinsic_Unary_Operator;
6726 ------------------------
6727 -- Resolve_Logical_Op --
6728 ------------------------
6730 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6734 Check_No_Direct_Boolean_Operators (N);
6736 -- Predefined operations on scalar types yield the base type. On the
6737 -- other hand, logical operations on arrays yield the type of the
6738 -- arguments (and the context).
6740 if Is_Array_Type (Typ) then
6743 B_Typ := Base_Type (Typ);
6746 -- The following test is required because the operands of the operation
6747 -- may be literals, in which case the resulting type appears to be
6748 -- compatible with a signed integer type, when in fact it is compatible
6749 -- only with modular types. If the context itself is universal, the
6750 -- operation is illegal.
6752 if not Valid_Boolean_Arg (Typ) then
6753 Error_Msg_N ("invalid context for logical operation", N);
6754 Set_Etype (N, Any_Type);
6757 elsif Typ = Any_Modular then
6759 ("no modular type available in this context", N);
6760 Set_Etype (N, Any_Type);
6762 elsif Is_Modular_Integer_Type (Typ)
6763 and then Etype (Left_Opnd (N)) = Universal_Integer
6764 and then Etype (Right_Opnd (N)) = Universal_Integer
6766 Check_For_Visible_Operator (N, B_Typ);
6769 Resolve (Left_Opnd (N), B_Typ);
6770 Resolve (Right_Opnd (N), B_Typ);
6772 Check_Unset_Reference (Left_Opnd (N));
6773 Check_Unset_Reference (Right_Opnd (N));
6775 Set_Etype (N, B_Typ);
6776 Generate_Operator_Reference (N, B_Typ);
6777 Eval_Logical_Op (N);
6778 end Resolve_Logical_Op;
6780 ---------------------------
6781 -- Resolve_Membership_Op --
6782 ---------------------------
6784 -- The context can only be a boolean type, and does not determine
6785 -- the arguments. Arguments should be unambiguous, but the preference
6786 -- rule for universal types applies.
6788 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6789 pragma Warnings (Off, Typ);
6791 L : constant Node_Id := Left_Opnd (N);
6792 R : constant Node_Id := Right_Opnd (N);
6795 procedure Resolve_Set_Membership;
6796 -- Analysis has determined a unique type for the left operand.
6797 -- Use it to resolve the disjuncts.
6799 ----------------------------
6800 -- Resolve_Set_Membership --
6801 ----------------------------
6803 procedure Resolve_Set_Membership is
6807 Resolve (L, Etype (L));
6809 Alt := First (Alternatives (N));
6810 while Present (Alt) loop
6812 -- Alternative is an expression, a range
6813 -- or a subtype mark.
6815 if not Is_Entity_Name (Alt)
6816 or else not Is_Type (Entity (Alt))
6818 Resolve (Alt, Etype (L));
6823 end Resolve_Set_Membership;
6825 -- Start of processing for Resolve_Membership_Op
6828 if L = Error or else R = Error then
6832 if Present (Alternatives (N)) then
6833 Resolve_Set_Membership;
6836 elsif not Is_Overloaded (R)
6838 (Etype (R) = Universal_Integer or else
6839 Etype (R) = Universal_Real)
6840 and then Is_Overloaded (L)
6844 -- Ada 2005 (AI-251): Support the following case:
6846 -- type I is interface;
6847 -- type T is tagged ...
6849 -- function Test (O : I'Class) is
6851 -- return O in T'Class.
6854 -- In this case we have nothing else to do. The membership test will be
6855 -- done at run-time.
6857 elsif Ada_Version >= Ada_05
6858 and then Is_Class_Wide_Type (Etype (L))
6859 and then Is_Interface (Etype (L))
6860 and then Is_Class_Wide_Type (Etype (R))
6861 and then not Is_Interface (Etype (R))
6866 T := Intersect_Types (L, R);
6870 Check_Unset_Reference (L);
6872 if Nkind (R) = N_Range
6873 and then not Is_Scalar_Type (T)
6875 Error_Msg_N ("scalar type required for range", R);
6878 if Is_Entity_Name (R) then
6879 Freeze_Expression (R);
6882 Check_Unset_Reference (R);
6885 Eval_Membership_Op (N);
6886 end Resolve_Membership_Op;
6892 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6893 Loc : constant Source_Ptr := Sloc (N);
6896 -- Handle restriction against anonymous null access values This
6897 -- restriction can be turned off using -gnatdj.
6899 -- Ada 2005 (AI-231): Remove restriction
6901 if Ada_Version < Ada_05
6902 and then not Debug_Flag_J
6903 and then Ekind (Typ) = E_Anonymous_Access_Type
6904 and then Comes_From_Source (N)
6906 -- In the common case of a call which uses an explicitly null value
6907 -- for an access parameter, give specialized error message.
6909 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6913 ("null is not allowed as argument for an access parameter", N);
6915 -- Standard message for all other cases (are there any?)
6919 ("null cannot be of an anonymous access type", N);
6923 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6924 -- assignment to a null-excluding object
6926 if Ada_Version >= Ada_05
6927 and then Can_Never_Be_Null (Typ)
6928 and then Nkind (Parent (N)) = N_Assignment_Statement
6930 if not Inside_Init_Proc then
6932 (Compile_Time_Constraint_Error (N,
6933 "(Ada 2005) null not allowed in null-excluding objects?"),
6934 Make_Raise_Constraint_Error (Loc,
6935 Reason => CE_Access_Check_Failed));
6938 Make_Raise_Constraint_Error (Loc,
6939 Reason => CE_Access_Check_Failed));
6943 -- In a distributed context, null for a remote access to subprogram may
6944 -- need to be replaced with a special record aggregate. In this case,
6945 -- return after having done the transformation.
6947 if (Ekind (Typ) = E_Record_Type
6948 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6949 and then Remote_AST_Null_Value (N, Typ)
6954 -- The null literal takes its type from the context
6959 -----------------------
6960 -- Resolve_Op_Concat --
6961 -----------------------
6963 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6965 -- We wish to avoid deep recursion, because concatenations are often
6966 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6967 -- operands nonrecursively until we find something that is not a simple
6968 -- concatenation (A in this case). We resolve that, and then walk back
6969 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6970 -- to do the rest of the work at each level. The Parent pointers allow
6971 -- us to avoid recursion, and thus avoid running out of memory. See also
6972 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6978 -- The following code is equivalent to:
6980 -- Resolve_Op_Concat_First (NN, Typ);
6981 -- Resolve_Op_Concat_Arg (N, ...);
6982 -- Resolve_Op_Concat_Rest (N, Typ);
6984 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6985 -- operand is a concatenation.
6987 -- Walk down left operands
6990 Resolve_Op_Concat_First (NN, Typ);
6991 Op1 := Left_Opnd (NN);
6992 exit when not (Nkind (Op1) = N_Op_Concat
6993 and then not Is_Array_Type (Component_Type (Typ))
6994 and then Entity (Op1) = Entity (NN));
6998 -- Now (given the above example) NN is A&B and Op1 is A
7000 -- First resolve Op1 ...
7002 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7004 -- ... then walk NN back up until we reach N (where we started), calling
7005 -- Resolve_Op_Concat_Rest along the way.
7008 Resolve_Op_Concat_Rest (NN, Typ);
7012 end Resolve_Op_Concat;
7014 ---------------------------
7015 -- Resolve_Op_Concat_Arg --
7016 ---------------------------
7018 procedure Resolve_Op_Concat_Arg
7024 Btyp : constant Entity_Id := Base_Type (Typ);
7029 or else (not Is_Overloaded (Arg)
7030 and then Etype (Arg) /= Any_Composite
7031 and then Covers (Component_Type (Typ), Etype (Arg)))
7033 Resolve (Arg, Component_Type (Typ));
7035 Resolve (Arg, Btyp);
7038 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
7039 if Nkind (Arg) = N_Aggregate
7040 and then Is_Composite_Type (Component_Type (Typ))
7042 if Is_Private_Type (Component_Type (Typ)) then
7043 Resolve (Arg, Btyp);
7045 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7046 Set_Etype (Arg, Any_Type);
7050 if Is_Overloaded (Arg)
7051 and then Has_Compatible_Type (Arg, Typ)
7052 and then Etype (Arg) /= Any_Type
7060 Get_First_Interp (Arg, I, It);
7062 Get_Next_Interp (I, It);
7064 -- Special-case the error message when the overloading is
7065 -- caused by a function that yields an array and can be
7066 -- called without parameters.
7068 if It.Nam = Func then
7069 Error_Msg_Sloc := Sloc (Func);
7070 Error_Msg_N ("ambiguous call to function#", Arg);
7072 ("\\interpretation as call yields&", Arg, Typ);
7074 ("\\interpretation as indexing of call yields&",
7075 Arg, Component_Type (Typ));
7079 ("ambiguous operand for concatenation!", Arg);
7080 Get_First_Interp (Arg, I, It);
7081 while Present (It.Nam) loop
7082 Error_Msg_Sloc := Sloc (It.Nam);
7084 if Base_Type (It.Typ) = Base_Type (Typ)
7085 or else Base_Type (It.Typ) =
7086 Base_Type (Component_Type (Typ))
7088 Error_Msg_N -- CODEFIX
7089 ("\\possible interpretation#", Arg);
7092 Get_Next_Interp (I, It);
7098 Resolve (Arg, Component_Type (Typ));
7100 if Nkind (Arg) = N_String_Literal then
7101 Set_Etype (Arg, Component_Type (Typ));
7104 if Arg = Left_Opnd (N) then
7105 Set_Is_Component_Left_Opnd (N);
7107 Set_Is_Component_Right_Opnd (N);
7112 Resolve (Arg, Btyp);
7115 Check_Unset_Reference (Arg);
7116 end Resolve_Op_Concat_Arg;
7118 -----------------------------
7119 -- Resolve_Op_Concat_First --
7120 -----------------------------
7122 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7123 Btyp : constant Entity_Id := Base_Type (Typ);
7124 Op1 : constant Node_Id := Left_Opnd (N);
7125 Op2 : constant Node_Id := Right_Opnd (N);
7128 -- The parser folds an enormous sequence of concatenations of string
7129 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7130 -- in the right operand. If the expression resolves to a predefined "&"
7131 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7132 -- we give an error. See P_Simple_Expression in Par.Ch4.
7134 if Nkind (Op2) = N_String_Literal
7135 and then Is_Folded_In_Parser (Op2)
7136 and then Ekind (Entity (N)) = E_Function
7138 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7139 and then String_Length (Strval (Op1)) = 0);
7140 Error_Msg_N ("too many user-defined concatenations", N);
7144 Set_Etype (N, Btyp);
7146 if Is_Limited_Composite (Btyp) then
7147 Error_Msg_N ("concatenation not available for limited array", N);
7148 Explain_Limited_Type (Btyp, N);
7150 end Resolve_Op_Concat_First;
7152 ----------------------------
7153 -- Resolve_Op_Concat_Rest --
7154 ----------------------------
7156 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7157 Op1 : constant Node_Id := Left_Opnd (N);
7158 Op2 : constant Node_Id := Right_Opnd (N);
7161 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7163 Generate_Operator_Reference (N, Typ);
7165 if Is_String_Type (Typ) then
7166 Eval_Concatenation (N);
7169 -- If this is not a static concatenation, but the result is a string
7170 -- type (and not an array of strings) ensure that static string operands
7171 -- have their subtypes properly constructed.
7173 if Nkind (N) /= N_String_Literal
7174 and then Is_Character_Type (Component_Type (Typ))
7176 Set_String_Literal_Subtype (Op1, Typ);
7177 Set_String_Literal_Subtype (Op2, Typ);
7179 end Resolve_Op_Concat_Rest;
7181 ----------------------
7182 -- Resolve_Op_Expon --
7183 ----------------------
7185 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7186 B_Typ : constant Entity_Id := Base_Type (Typ);
7189 -- Catch attempts to do fixed-point exponentiation with universal
7190 -- operands, which is a case where the illegality is not caught during
7191 -- normal operator analysis.
7193 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7194 Error_Msg_N ("exponentiation not available for fixed point", N);
7198 if Comes_From_Source (N)
7199 and then Ekind (Entity (N)) = E_Function
7200 and then Is_Imported (Entity (N))
7201 and then Is_Intrinsic_Subprogram (Entity (N))
7203 Resolve_Intrinsic_Operator (N, Typ);
7207 if Etype (Left_Opnd (N)) = Universal_Integer
7208 or else Etype (Left_Opnd (N)) = Universal_Real
7210 Check_For_Visible_Operator (N, B_Typ);
7213 -- We do the resolution using the base type, because intermediate values
7214 -- in expressions always are of the base type, not a subtype of it.
7216 Resolve (Left_Opnd (N), B_Typ);
7217 Resolve (Right_Opnd (N), Standard_Integer);
7219 Check_Unset_Reference (Left_Opnd (N));
7220 Check_Unset_Reference (Right_Opnd (N));
7222 Set_Etype (N, B_Typ);
7223 Generate_Operator_Reference (N, B_Typ);
7226 -- Set overflow checking bit. Much cleverer code needed here eventually
7227 -- and perhaps the Resolve routines should be separated for the various
7228 -- arithmetic operations, since they will need different processing. ???
7230 if Nkind (N) in N_Op then
7231 if not Overflow_Checks_Suppressed (Etype (N)) then
7232 Enable_Overflow_Check (N);
7235 end Resolve_Op_Expon;
7237 --------------------
7238 -- Resolve_Op_Not --
7239 --------------------
7241 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7244 function Parent_Is_Boolean return Boolean;
7245 -- This function determines if the parent node is a boolean operator
7246 -- or operation (comparison op, membership test, or short circuit form)
7247 -- and the not in question is the left operand of this operation.
7248 -- Note that if the not is in parens, then false is returned.
7250 -----------------------
7251 -- Parent_Is_Boolean --
7252 -----------------------
7254 function Parent_Is_Boolean return Boolean is
7256 if Paren_Count (N) /= 0 then
7260 case Nkind (Parent (N)) is
7275 return Left_Opnd (Parent (N)) = N;
7281 end Parent_Is_Boolean;
7283 -- Start of processing for Resolve_Op_Not
7286 -- Predefined operations on scalar types yield the base type. On the
7287 -- other hand, logical operations on arrays yield the type of the
7288 -- arguments (and the context).
7290 if Is_Array_Type (Typ) then
7293 B_Typ := Base_Type (Typ);
7296 -- Straightforward case of incorrect arguments
7298 if not Valid_Boolean_Arg (Typ) then
7299 Error_Msg_N ("invalid operand type for operator&", N);
7300 Set_Etype (N, Any_Type);
7303 -- Special case of probable missing parens
7305 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7306 if Parent_Is_Boolean then
7308 ("operand of not must be enclosed in parentheses",
7312 ("no modular type available in this context", N);
7315 Set_Etype (N, Any_Type);
7318 -- OK resolution of not
7321 -- Warn if non-boolean types involved. This is a case like not a < b
7322 -- where a and b are modular, where we will get (not a) < b and most
7323 -- likely not (a < b) was intended.
7325 if Warn_On_Questionable_Missing_Parens
7326 and then not Is_Boolean_Type (Typ)
7327 and then Parent_Is_Boolean
7329 Error_Msg_N ("?not expression should be parenthesized here!", N);
7332 -- Warn on double negation if checking redundant constructs
7334 if Warn_On_Redundant_Constructs
7335 and then Comes_From_Source (N)
7336 and then Comes_From_Source (Right_Opnd (N))
7337 and then Root_Type (Typ) = Standard_Boolean
7338 and then Nkind (Right_Opnd (N)) = N_Op_Not
7340 Error_Msg_N ("redundant double negation?", N);
7343 -- Complete resolution and evaluation of NOT
7345 Resolve (Right_Opnd (N), B_Typ);
7346 Check_Unset_Reference (Right_Opnd (N));
7347 Set_Etype (N, B_Typ);
7348 Generate_Operator_Reference (N, B_Typ);
7353 -----------------------------
7354 -- Resolve_Operator_Symbol --
7355 -----------------------------
7357 -- Nothing to be done, all resolved already
7359 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7360 pragma Warnings (Off, N);
7361 pragma Warnings (Off, Typ);
7365 end Resolve_Operator_Symbol;
7367 ----------------------------------
7368 -- Resolve_Qualified_Expression --
7369 ----------------------------------
7371 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7372 pragma Warnings (Off, Typ);
7374 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7375 Expr : constant Node_Id := Expression (N);
7378 Resolve (Expr, Target_Typ);
7380 -- A qualified expression requires an exact match of the type,
7381 -- class-wide matching is not allowed. However, if the qualifying
7382 -- type is specific and the expression has a class-wide type, it
7383 -- may still be okay, since it can be the result of the expansion
7384 -- of a call to a dispatching function, so we also have to check
7385 -- class-wideness of the type of the expression's original node.
7387 if (Is_Class_Wide_Type (Target_Typ)
7389 (Is_Class_Wide_Type (Etype (Expr))
7390 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7391 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7393 Wrong_Type (Expr, Target_Typ);
7396 -- If the target type is unconstrained, then we reset the type of
7397 -- the result from the type of the expression. For other cases, the
7398 -- actual subtype of the expression is the target type.
7400 if Is_Composite_Type (Target_Typ)
7401 and then not Is_Constrained (Target_Typ)
7403 Set_Etype (N, Etype (Expr));
7406 Eval_Qualified_Expression (N);
7407 end Resolve_Qualified_Expression;
7413 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7414 L : constant Node_Id := Low_Bound (N);
7415 H : constant Node_Id := High_Bound (N);
7422 Check_Unset_Reference (L);
7423 Check_Unset_Reference (H);
7425 -- We have to check the bounds for being within the base range as
7426 -- required for a non-static context. Normally this is automatic and
7427 -- done as part of evaluating expressions, but the N_Range node is an
7428 -- exception, since in GNAT we consider this node to be a subexpression,
7429 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7430 -- this, but that would put the test on the main evaluation path for
7433 Check_Non_Static_Context (L);
7434 Check_Non_Static_Context (H);
7436 -- Check for an ambiguous range over character literals. This will
7437 -- happen with a membership test involving only literals.
7439 if Typ = Any_Character then
7440 Ambiguous_Character (L);
7441 Set_Etype (N, Any_Type);
7445 -- If bounds are static, constant-fold them, so size computations
7446 -- are identical between front-end and back-end. Do not perform this
7447 -- transformation while analyzing generic units, as type information
7448 -- would then be lost when reanalyzing the constant node in the
7451 if Is_Discrete_Type (Typ) and then Expander_Active then
7452 if Is_OK_Static_Expression (L) then
7453 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7456 if Is_OK_Static_Expression (H) then
7457 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7462 --------------------------
7463 -- Resolve_Real_Literal --
7464 --------------------------
7466 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7467 Actual_Typ : constant Entity_Id := Etype (N);
7470 -- Special processing for fixed-point literals to make sure that the
7471 -- value is an exact multiple of small where this is required. We
7472 -- skip this for the universal real case, and also for generic types.
7474 if Is_Fixed_Point_Type (Typ)
7475 and then Typ /= Universal_Fixed
7476 and then Typ /= Any_Fixed
7477 and then not Is_Generic_Type (Typ)
7480 Val : constant Ureal := Realval (N);
7481 Cintr : constant Ureal := Val / Small_Value (Typ);
7482 Cint : constant Uint := UR_Trunc (Cintr);
7483 Den : constant Uint := Norm_Den (Cintr);
7487 -- Case of literal is not an exact multiple of the Small
7491 -- For a source program literal for a decimal fixed-point
7492 -- type, this is statically illegal (RM 4.9(36)).
7494 if Is_Decimal_Fixed_Point_Type (Typ)
7495 and then Actual_Typ = Universal_Real
7496 and then Comes_From_Source (N)
7498 Error_Msg_N ("value has extraneous low order digits", N);
7501 -- Generate a warning if literal from source
7503 if Is_Static_Expression (N)
7504 and then Warn_On_Bad_Fixed_Value
7507 ("?static fixed-point value is not a multiple of Small!",
7511 -- Replace literal by a value that is the exact representation
7512 -- of a value of the type, i.e. a multiple of the small value,
7513 -- by truncation, since Machine_Rounds is false for all GNAT
7514 -- fixed-point types (RM 4.9(38)).
7516 Stat := Is_Static_Expression (N);
7518 Make_Real_Literal (Sloc (N),
7519 Realval => Small_Value (Typ) * Cint));
7521 Set_Is_Static_Expression (N, Stat);
7524 -- In all cases, set the corresponding integer field
7526 Set_Corresponding_Integer_Value (N, Cint);
7530 -- Now replace the actual type by the expected type as usual
7533 Eval_Real_Literal (N);
7534 end Resolve_Real_Literal;
7536 -----------------------
7537 -- Resolve_Reference --
7538 -----------------------
7540 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7541 P : constant Node_Id := Prefix (N);
7544 -- Replace general access with specific type
7546 if Ekind (Etype (N)) = E_Allocator_Type then
7547 Set_Etype (N, Base_Type (Typ));
7550 Resolve (P, Designated_Type (Etype (N)));
7552 -- If we are taking the reference of a volatile entity, then treat
7553 -- it as a potential modification of this entity. This is much too
7554 -- conservative, but is necessary because remove side effects can
7555 -- result in transformations of normal assignments into reference
7556 -- sequences that otherwise fail to notice the modification.
7558 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7559 Note_Possible_Modification (P, Sure => False);
7561 end Resolve_Reference;
7563 --------------------------------
7564 -- Resolve_Selected_Component --
7565 --------------------------------
7567 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7569 Comp1 : Entity_Id := Empty; -- prevent junk warning
7570 P : constant Node_Id := Prefix (N);
7571 S : constant Node_Id := Selector_Name (N);
7572 T : Entity_Id := Etype (P);
7574 I1 : Interp_Index := 0; -- prevent junk warning
7579 function Init_Component return Boolean;
7580 -- Check whether this is the initialization of a component within an
7581 -- init proc (by assignment or call to another init proc). If true,
7582 -- there is no need for a discriminant check.
7584 --------------------
7585 -- Init_Component --
7586 --------------------
7588 function Init_Component return Boolean is
7590 return Inside_Init_Proc
7591 and then Nkind (Prefix (N)) = N_Identifier
7592 and then Chars (Prefix (N)) = Name_uInit
7593 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7596 -- Start of processing for Resolve_Selected_Component
7599 if Is_Overloaded (P) then
7601 -- Use the context type to select the prefix that has a selector
7602 -- of the correct name and type.
7605 Get_First_Interp (P, I, It);
7607 Search : while Present (It.Typ) loop
7608 if Is_Access_Type (It.Typ) then
7609 T := Designated_Type (It.Typ);
7614 if Is_Record_Type (T) then
7616 -- The visible components of a class-wide type are those of
7619 if Is_Class_Wide_Type (T) then
7623 Comp := First_Entity (T);
7624 while Present (Comp) loop
7625 if Chars (Comp) = Chars (S)
7626 and then Covers (Etype (Comp), Typ)
7635 It := Disambiguate (P, I1, I, Any_Type);
7637 if It = No_Interp then
7639 ("ambiguous prefix for selected component", N);
7646 -- There may be an implicit dereference. Retrieve
7647 -- designated record type.
7649 if Is_Access_Type (It1.Typ) then
7650 T := Designated_Type (It1.Typ);
7655 if Scope (Comp1) /= T then
7657 -- Resolution chooses the new interpretation.
7658 -- Find the component with the right name.
7660 Comp1 := First_Entity (T);
7661 while Present (Comp1)
7662 and then Chars (Comp1) /= Chars (S)
7664 Comp1 := Next_Entity (Comp1);
7673 Comp := Next_Entity (Comp);
7678 Get_Next_Interp (I, It);
7681 Resolve (P, It1.Typ);
7683 Set_Entity_With_Style_Check (S, Comp1);
7686 -- Resolve prefix with its type
7691 -- Generate cross-reference. We needed to wait until full overloading
7692 -- resolution was complete to do this, since otherwise we can't tell if
7693 -- we are an lvalue or not.
7695 if May_Be_Lvalue (N) then
7696 Generate_Reference (Entity (S), S, 'm');
7698 Generate_Reference (Entity (S), S, 'r');
7701 -- If prefix is an access type, the node will be transformed into an
7702 -- explicit dereference during expansion. The type of the node is the
7703 -- designated type of that of the prefix.
7705 if Is_Access_Type (Etype (P)) then
7706 T := Designated_Type (Etype (P));
7707 Check_Fully_Declared_Prefix (T, P);
7712 if Has_Discriminants (T)
7713 and then (Ekind (Entity (S)) = E_Component
7715 Ekind (Entity (S)) = E_Discriminant)
7716 and then Present (Original_Record_Component (Entity (S)))
7717 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7718 and then Present (Discriminant_Checking_Func
7719 (Original_Record_Component (Entity (S))))
7720 and then not Discriminant_Checks_Suppressed (T)
7721 and then not Init_Component
7723 Set_Do_Discriminant_Check (N);
7726 if Ekind (Entity (S)) = E_Void then
7727 Error_Msg_N ("premature use of component", S);
7730 -- If the prefix is a record conversion, this may be a renamed
7731 -- discriminant whose bounds differ from those of the original
7732 -- one, so we must ensure that a range check is performed.
7734 if Nkind (P) = N_Type_Conversion
7735 and then Ekind (Entity (S)) = E_Discriminant
7736 and then Is_Discrete_Type (Typ)
7738 Set_Etype (N, Base_Type (Typ));
7741 -- Note: No Eval processing is required, because the prefix is of a
7742 -- record type, or protected type, and neither can possibly be static.
7744 end Resolve_Selected_Component;
7750 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7751 B_Typ : constant Entity_Id := Base_Type (Typ);
7752 L : constant Node_Id := Left_Opnd (N);
7753 R : constant Node_Id := Right_Opnd (N);
7756 -- We do the resolution using the base type, because intermediate values
7757 -- in expressions always are of the base type, not a subtype of it.
7760 Resolve (R, Standard_Natural);
7762 Check_Unset_Reference (L);
7763 Check_Unset_Reference (R);
7765 Set_Etype (N, B_Typ);
7766 Generate_Operator_Reference (N, B_Typ);
7770 ---------------------------
7771 -- Resolve_Short_Circuit --
7772 ---------------------------
7774 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7775 B_Typ : constant Entity_Id := Base_Type (Typ);
7776 L : constant Node_Id := Left_Opnd (N);
7777 R : constant Node_Id := Right_Opnd (N);
7783 -- Check for issuing warning for always False assert/check, this happens
7784 -- when assertions are turned off, in which case the pragma Assert/Check
7785 -- was transformed into:
7787 -- if False and then <condition> then ...
7789 -- and we detect this pattern
7791 if Warn_On_Assertion_Failure
7792 and then Is_Entity_Name (R)
7793 and then Entity (R) = Standard_False
7794 and then Nkind (Parent (N)) = N_If_Statement
7795 and then Nkind (N) = N_And_Then
7796 and then Is_Entity_Name (L)
7797 and then Entity (L) = Standard_False
7800 Orig : constant Node_Id := Original_Node (Parent (N));
7803 if Nkind (Orig) = N_Pragma
7804 and then Pragma_Name (Orig) = Name_Assert
7806 -- Don't want to warn if original condition is explicit False
7809 Expr : constant Node_Id :=
7812 (First (Pragma_Argument_Associations (Orig))));
7814 if Is_Entity_Name (Expr)
7815 and then Entity (Expr) = Standard_False
7819 -- Issue warning. Note that we don't want to make this
7820 -- an unconditional warning, because if the assert is
7821 -- within deleted code we do not want the warning. But
7822 -- we do not want the deletion of the IF/AND-THEN to
7823 -- take this message with it. We achieve this by making
7824 -- sure that the expanded code points to the Sloc of
7825 -- the expression, not the original pragma.
7827 Error_Msg_N ("?assertion would fail at run-time", Orig);
7831 -- Similar processing for Check pragma
7833 elsif Nkind (Orig) = N_Pragma
7834 and then Pragma_Name (Orig) = Name_Check
7836 -- Don't want to warn if original condition is explicit False
7839 Expr : constant Node_Id :=
7843 (Pragma_Argument_Associations (Orig)))));
7845 if Is_Entity_Name (Expr)
7846 and then Entity (Expr) = Standard_False
7850 Error_Msg_N ("?check would fail at run-time", Orig);
7857 -- Continue with processing of short circuit
7859 Check_Unset_Reference (L);
7860 Check_Unset_Reference (R);
7862 Set_Etype (N, B_Typ);
7863 Eval_Short_Circuit (N);
7864 end Resolve_Short_Circuit;
7870 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7871 Name : constant Node_Id := Prefix (N);
7872 Drange : constant Node_Id := Discrete_Range (N);
7873 Array_Type : Entity_Id := Empty;
7877 if Is_Overloaded (Name) then
7879 -- Use the context type to select the prefix that yields the correct
7884 I1 : Interp_Index := 0;
7886 P : constant Node_Id := Prefix (N);
7887 Found : Boolean := False;
7890 Get_First_Interp (P, I, It);
7891 while Present (It.Typ) loop
7892 if (Is_Array_Type (It.Typ)
7893 and then Covers (Typ, It.Typ))
7894 or else (Is_Access_Type (It.Typ)
7895 and then Is_Array_Type (Designated_Type (It.Typ))
7896 and then Covers (Typ, Designated_Type (It.Typ)))
7899 It := Disambiguate (P, I1, I, Any_Type);
7901 if It = No_Interp then
7902 Error_Msg_N ("ambiguous prefix for slicing", N);
7907 Array_Type := It.Typ;
7912 Array_Type := It.Typ;
7917 Get_Next_Interp (I, It);
7922 Array_Type := Etype (Name);
7925 Resolve (Name, Array_Type);
7927 if Is_Access_Type (Array_Type) then
7928 Apply_Access_Check (N);
7929 Array_Type := Designated_Type (Array_Type);
7931 -- If the prefix is an access to an unconstrained array, we must use
7932 -- the actual subtype of the object to perform the index checks. The
7933 -- object denoted by the prefix is implicit in the node, so we build
7934 -- an explicit representation for it in order to compute the actual
7937 if not Is_Constrained (Array_Type) then
7938 Remove_Side_Effects (Prefix (N));
7941 Obj : constant Node_Id :=
7942 Make_Explicit_Dereference (Sloc (N),
7943 Prefix => New_Copy_Tree (Prefix (N)));
7945 Set_Etype (Obj, Array_Type);
7946 Set_Parent (Obj, Parent (N));
7947 Array_Type := Get_Actual_Subtype (Obj);
7951 elsif Is_Entity_Name (Name)
7952 or else (Nkind (Name) = N_Function_Call
7953 and then not Is_Constrained (Etype (Name)))
7955 Array_Type := Get_Actual_Subtype (Name);
7957 -- If the name is a selected component that depends on discriminants,
7958 -- build an actual subtype for it. This can happen only when the name
7959 -- itself is overloaded; otherwise the actual subtype is created when
7960 -- the selected component is analyzed.
7962 elsif Nkind (Name) = N_Selected_Component
7963 and then Full_Analysis
7964 and then Depends_On_Discriminant (First_Index (Array_Type))
7967 Act_Decl : constant Node_Id :=
7968 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7970 Insert_Action (N, Act_Decl);
7971 Array_Type := Defining_Identifier (Act_Decl);
7974 -- Maybe this should just be "else", instead of checking for the
7975 -- specific case of slice??? This is needed for the case where
7976 -- the prefix is an Image attribute, which gets expanded to a
7977 -- slice, and so has a constrained subtype which we want to use
7978 -- for the slice range check applied below (the range check won't
7979 -- get done if the unconstrained subtype of the 'Image is used).
7981 elsif Nkind (Name) = N_Slice then
7982 Array_Type := Etype (Name);
7985 -- If name was overloaded, set slice type correctly now
7987 Set_Etype (N, Array_Type);
7989 -- If the range is specified by a subtype mark, no resolution is
7990 -- necessary. Else resolve the bounds, and apply needed checks.
7992 if not Is_Entity_Name (Drange) then
7993 Index := First_Index (Array_Type);
7994 Resolve (Drange, Base_Type (Etype (Index)));
7996 if Nkind (Drange) = N_Range
7998 -- Do not apply the range check to nodes associated with the
7999 -- frontend expansion of the dispatch table. We first check
8000 -- if Ada.Tags is already loaded to void the addition of an
8001 -- undesired dependence on such run-time unit.
8004 (not Tagged_Type_Expansion
8006 (RTU_Loaded (Ada_Tags)
8007 and then Nkind (Prefix (N)) = N_Selected_Component
8008 and then Present (Entity (Selector_Name (Prefix (N))))
8009 and then Entity (Selector_Name (Prefix (N))) =
8010 RTE_Record_Component (RE_Prims_Ptr)))
8012 Apply_Range_Check (Drange, Etype (Index));
8016 Set_Slice_Subtype (N);
8018 if Nkind (Drange) = N_Range then
8019 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8020 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8026 ----------------------------
8027 -- Resolve_String_Literal --
8028 ----------------------------
8030 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8031 C_Typ : constant Entity_Id := Component_Type (Typ);
8032 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8033 Loc : constant Source_Ptr := Sloc (N);
8034 Str : constant String_Id := Strval (N);
8035 Strlen : constant Nat := String_Length (Str);
8036 Subtype_Id : Entity_Id;
8037 Need_Check : Boolean;
8040 -- For a string appearing in a concatenation, defer creation of the
8041 -- string_literal_subtype until the end of the resolution of the
8042 -- concatenation, because the literal may be constant-folded away. This
8043 -- is a useful optimization for long concatenation expressions.
8045 -- If the string is an aggregate built for a single character (which
8046 -- happens in a non-static context) or a is null string to which special
8047 -- checks may apply, we build the subtype. Wide strings must also get a
8048 -- string subtype if they come from a one character aggregate. Strings
8049 -- generated by attributes might be static, but it is often hard to
8050 -- determine whether the enclosing context is static, so we generate
8051 -- subtypes for them as well, thus losing some rarer optimizations ???
8052 -- Same for strings that come from a static conversion.
8055 (Strlen = 0 and then Typ /= Standard_String)
8056 or else Nkind (Parent (N)) /= N_Op_Concat
8057 or else (N /= Left_Opnd (Parent (N))
8058 and then N /= Right_Opnd (Parent (N)))
8059 or else ((Typ = Standard_Wide_String
8060 or else Typ = Standard_Wide_Wide_String)
8061 and then Nkind (Original_Node (N)) /= N_String_Literal);
8063 -- If the resolving type is itself a string literal subtype, we can just
8064 -- reuse it, since there is no point in creating another.
8066 if Ekind (Typ) = E_String_Literal_Subtype then
8069 elsif Nkind (Parent (N)) = N_Op_Concat
8070 and then not Need_Check
8071 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8072 N_Attribute_Reference,
8073 N_Qualified_Expression,
8078 -- Otherwise we must create a string literal subtype. Note that the
8079 -- whole idea of string literal subtypes is simply to avoid the need
8080 -- for building a full fledged array subtype for each literal.
8083 Set_String_Literal_Subtype (N, Typ);
8084 Subtype_Id := Etype (N);
8087 if Nkind (Parent (N)) /= N_Op_Concat
8090 Set_Etype (N, Subtype_Id);
8091 Eval_String_Literal (N);
8094 if Is_Limited_Composite (Typ)
8095 or else Is_Private_Composite (Typ)
8097 Error_Msg_N ("string literal not available for private array", N);
8098 Set_Etype (N, Any_Type);
8102 -- The validity of a null string has been checked in the call to
8103 -- Eval_String_Literal.
8108 -- Always accept string literal with component type Any_Character, which
8109 -- occurs in error situations and in comparisons of literals, both of
8110 -- which should accept all literals.
8112 elsif R_Typ = Any_Character then
8115 -- If the type is bit-packed, then we always transform the string
8116 -- literal into a full fledged aggregate.
8118 elsif Is_Bit_Packed_Array (Typ) then
8121 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8124 -- For Standard.Wide_Wide_String, or any other type whose component
8125 -- type is Standard.Wide_Wide_Character, we know that all the
8126 -- characters in the string must be acceptable, since the parser
8127 -- accepted the characters as valid character literals.
8129 if R_Typ = Standard_Wide_Wide_Character then
8132 -- For the case of Standard.String, or any other type whose component
8133 -- type is Standard.Character, we must make sure that there are no
8134 -- wide characters in the string, i.e. that it is entirely composed
8135 -- of characters in range of type Character.
8137 -- If the string literal is the result of a static concatenation, the
8138 -- test has already been performed on the components, and need not be
8141 elsif R_Typ = Standard_Character
8142 and then Nkind (Original_Node (N)) /= N_Op_Concat
8144 for J in 1 .. Strlen loop
8145 if not In_Character_Range (Get_String_Char (Str, J)) then
8147 -- If we are out of range, post error. This is one of the
8148 -- very few places that we place the flag in the middle of
8149 -- a token, right under the offending wide character. Not
8150 -- quite clear if this is right wrt wide character encoding
8151 -- sequences, but it's only an error message!
8154 ("literal out of range of type Standard.Character",
8155 Source_Ptr (Int (Loc) + J));
8160 -- For the case of Standard.Wide_String, or any other type whose
8161 -- component type is Standard.Wide_Character, we must make sure that
8162 -- there are no wide characters in the string, i.e. that it is
8163 -- entirely composed of characters in range of type Wide_Character.
8165 -- If the string literal is the result of a static concatenation,
8166 -- the test has already been performed on the components, and need
8169 elsif R_Typ = Standard_Wide_Character
8170 and then Nkind (Original_Node (N)) /= N_Op_Concat
8172 for J in 1 .. Strlen loop
8173 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8175 -- If we are out of range, post error. This is one of the
8176 -- very few places that we place the flag in the middle of
8177 -- a token, right under the offending wide character.
8179 -- This is not quite right, because characters in general
8180 -- will take more than one character position ???
8183 ("literal out of range of type Standard.Wide_Character",
8184 Source_Ptr (Int (Loc) + J));
8189 -- If the root type is not a standard character, then we will convert
8190 -- the string into an aggregate and will let the aggregate code do
8191 -- the checking. Standard Wide_Wide_Character is also OK here.
8197 -- See if the component type of the array corresponding to the string
8198 -- has compile time known bounds. If yes we can directly check
8199 -- whether the evaluation of the string will raise constraint error.
8200 -- Otherwise we need to transform the string literal into the
8201 -- corresponding character aggregate and let the aggregate
8202 -- code do the checking.
8204 if Is_Standard_Character_Type (R_Typ) then
8206 -- Check for the case of full range, where we are definitely OK
8208 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8212 -- Here the range is not the complete base type range, so check
8215 Comp_Typ_Lo : constant Node_Id :=
8216 Type_Low_Bound (Component_Type (Typ));
8217 Comp_Typ_Hi : constant Node_Id :=
8218 Type_High_Bound (Component_Type (Typ));
8223 if Compile_Time_Known_Value (Comp_Typ_Lo)
8224 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8226 for J in 1 .. Strlen loop
8227 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8229 if Char_Val < Expr_Value (Comp_Typ_Lo)
8230 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8232 Apply_Compile_Time_Constraint_Error
8233 (N, "character out of range?", CE_Range_Check_Failed,
8234 Loc => Source_Ptr (Int (Loc) + J));
8244 -- If we got here we meed to transform the string literal into the
8245 -- equivalent qualified positional array aggregate. This is rather
8246 -- heavy artillery for this situation, but it is hard work to avoid.
8249 Lits : constant List_Id := New_List;
8250 P : Source_Ptr := Loc + 1;
8254 -- Build the character literals, we give them source locations that
8255 -- correspond to the string positions, which is a bit tricky given
8256 -- the possible presence of wide character escape sequences.
8258 for J in 1 .. Strlen loop
8259 C := Get_String_Char (Str, J);
8260 Set_Character_Literal_Name (C);
8263 Make_Character_Literal (P,
8265 Char_Literal_Value => UI_From_CC (C)));
8267 if In_Character_Range (C) then
8270 -- Should we have a call to Skip_Wide here ???
8278 Make_Qualified_Expression (Loc,
8279 Subtype_Mark => New_Reference_To (Typ, Loc),
8281 Make_Aggregate (Loc, Expressions => Lits)));
8283 Analyze_And_Resolve (N, Typ);
8285 end Resolve_String_Literal;
8287 -----------------------------
8288 -- Resolve_Subprogram_Info --
8289 -----------------------------
8291 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8294 end Resolve_Subprogram_Info;
8296 -----------------------------
8297 -- Resolve_Type_Conversion --
8298 -----------------------------
8300 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8301 Conv_OK : constant Boolean := Conversion_OK (N);
8302 Operand : constant Node_Id := Expression (N);
8303 Operand_Typ : constant Entity_Id := Etype (Operand);
8304 Target_Typ : constant Entity_Id := Etype (N);
8311 and then not Valid_Conversion (N, Target_Typ, Operand)
8316 if Etype (Operand) = Any_Fixed then
8318 -- Mixed-mode operation involving a literal. Context must be a fixed
8319 -- type which is applied to the literal subsequently.
8321 if Is_Fixed_Point_Type (Typ) then
8322 Set_Etype (Operand, Universal_Real);
8324 elsif Is_Numeric_Type (Typ)
8325 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8326 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8328 Etype (Left_Opnd (Operand)) = Universal_Real)
8330 -- Return if expression is ambiguous
8332 if Unique_Fixed_Point_Type (N) = Any_Type then
8335 -- If nothing else, the available fixed type is Duration
8338 Set_Etype (Operand, Standard_Duration);
8341 -- Resolve the real operand with largest available precision
8343 if Etype (Right_Opnd (Operand)) = Universal_Real then
8344 Rop := New_Copy_Tree (Right_Opnd (Operand));
8346 Rop := New_Copy_Tree (Left_Opnd (Operand));
8349 Resolve (Rop, Universal_Real);
8351 -- If the operand is a literal (it could be a non-static and
8352 -- illegal exponentiation) check whether the use of Duration
8353 -- is potentially inaccurate.
8355 if Nkind (Rop) = N_Real_Literal
8356 and then Realval (Rop) /= Ureal_0
8357 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8360 ("?universal real operand can only " &
8361 "be interpreted as Duration!",
8364 ("\?precision will be lost in the conversion!", Rop);
8367 elsif Is_Numeric_Type (Typ)
8368 and then Nkind (Operand) in N_Op
8369 and then Unique_Fixed_Point_Type (N) /= Any_Type
8371 Set_Etype (Operand, Standard_Duration);
8374 Error_Msg_N ("invalid context for mixed mode operation", N);
8375 Set_Etype (Operand, Any_Type);
8382 -- Note: we do the Eval_Type_Conversion call before applying the
8383 -- required checks for a subtype conversion. This is important, since
8384 -- both are prepared under certain circumstances to change the type
8385 -- conversion to a constraint error node, but in the case of
8386 -- Eval_Type_Conversion this may reflect an illegality in the static
8387 -- case, and we would miss the illegality (getting only a warning
8388 -- message), if we applied the type conversion checks first.
8390 Eval_Type_Conversion (N);
8392 -- Even when evaluation is not possible, we may be able to simplify the
8393 -- conversion or its expression. This needs to be done before applying
8394 -- checks, since otherwise the checks may use the original expression
8395 -- and defeat the simplifications. This is specifically the case for
8396 -- elimination of the floating-point Truncation attribute in
8397 -- float-to-int conversions.
8399 Simplify_Type_Conversion (N);
8401 -- If after evaluation we still have a type conversion, then we may need
8402 -- to apply checks required for a subtype conversion.
8404 -- Skip these type conversion checks if universal fixed operands
8405 -- operands involved, since range checks are handled separately for
8406 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8408 if Nkind (N) = N_Type_Conversion
8409 and then not Is_Generic_Type (Root_Type (Target_Typ))
8410 and then Target_Typ /= Universal_Fixed
8411 and then Operand_Typ /= Universal_Fixed
8413 Apply_Type_Conversion_Checks (N);
8416 -- Issue warning for conversion of simple object to its own type. We
8417 -- have to test the original nodes, since they may have been rewritten
8418 -- by various optimizations.
8420 Orig_N := Original_Node (N);
8422 if Warn_On_Redundant_Constructs
8423 and then Comes_From_Source (Orig_N)
8424 and then Nkind (Orig_N) = N_Type_Conversion
8425 and then not In_Instance
8427 Orig_N := Original_Node (Expression (Orig_N));
8428 Orig_T := Target_Typ;
8430 -- If the node is part of a larger expression, the Target_Type
8431 -- may not be the original type of the node if the context is a
8432 -- condition. Recover original type to see if conversion is needed.
8434 if Is_Boolean_Type (Orig_T)
8435 and then Nkind (Parent (N)) in N_Op
8437 Orig_T := Etype (Parent (N));
8440 if Is_Entity_Name (Orig_N)
8442 (Etype (Entity (Orig_N)) = Orig_T
8444 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8445 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8447 -- One more check, do not give warning if the analyzed conversion
8448 -- has an expression with non-static bounds, and the bounds of the
8449 -- target are static. This avoids junk warnings in cases where the
8450 -- conversion is necessary to establish staticness, for example in
8451 -- a case statement.
8453 if not Is_OK_Static_Subtype (Operand_Typ)
8454 and then Is_OK_Static_Subtype (Target_Typ)
8458 -- Here we give the redundant conversion warning
8461 Error_Msg_Node_2 := Orig_T;
8462 Error_Msg_NE -- CODEFIX
8463 ("?redundant conversion, & is of type &!",
8464 N, Entity (Orig_N));
8469 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8470 -- No need to perform any interface conversion if the type of the
8471 -- expression coincides with the target type.
8473 if Ada_Version >= Ada_05
8474 and then Expander_Active
8475 and then Operand_Typ /= Target_Typ
8478 Opnd : Entity_Id := Operand_Typ;
8479 Target : Entity_Id := Target_Typ;
8482 if Is_Access_Type (Opnd) then
8483 Opnd := Directly_Designated_Type (Opnd);
8486 if Is_Access_Type (Target_Typ) then
8487 Target := Directly_Designated_Type (Target);
8490 if Opnd = Target then
8493 -- Conversion from interface type
8495 elsif Is_Interface (Opnd) then
8497 -- Ada 2005 (AI-217): Handle entities from limited views
8499 if From_With_Type (Opnd) then
8500 Error_Msg_Qual_Level := 99;
8501 Error_Msg_NE ("missing WITH clause on package &", N,
8502 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8504 ("type conversions require visibility of the full view",
8507 elsif From_With_Type (Target)
8509 (Is_Access_Type (Target_Typ)
8510 and then Present (Non_Limited_View (Etype (Target))))
8512 Error_Msg_Qual_Level := 99;
8513 Error_Msg_NE ("missing WITH clause on package &", N,
8514 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8516 ("type conversions require visibility of the full view",
8520 Expand_Interface_Conversion (N, Is_Static => False);
8523 -- Conversion to interface type
8525 elsif Is_Interface (Target) then
8529 if Ekind (Opnd) = E_Protected_Subtype
8530 or else Ekind (Opnd) = E_Task_Subtype
8532 Opnd := Etype (Opnd);
8535 if not Interface_Present_In_Ancestor
8539 if Is_Class_Wide_Type (Opnd) then
8541 -- The static analysis is not enough to know if the
8542 -- interface is implemented or not. Hence we must pass
8543 -- the work to the expander to generate code to evaluate
8544 -- the conversion at run-time.
8546 Expand_Interface_Conversion (N, Is_Static => False);
8549 Error_Msg_Name_1 := Chars (Etype (Target));
8550 Error_Msg_Name_2 := Chars (Opnd);
8552 ("wrong interface conversion (% is not a progenitor " &
8557 Expand_Interface_Conversion (N);
8562 end Resolve_Type_Conversion;
8564 ----------------------
8565 -- Resolve_Unary_Op --
8566 ----------------------
8568 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8569 B_Typ : constant Entity_Id := Base_Type (Typ);
8570 R : constant Node_Id := Right_Opnd (N);
8576 -- Deal with intrinsic unary operators
8578 if Comes_From_Source (N)
8579 and then Ekind (Entity (N)) = E_Function
8580 and then Is_Imported (Entity (N))
8581 and then Is_Intrinsic_Subprogram (Entity (N))
8583 Resolve_Intrinsic_Unary_Operator (N, Typ);
8587 -- Deal with universal cases
8589 if Etype (R) = Universal_Integer
8591 Etype (R) = Universal_Real
8593 Check_For_Visible_Operator (N, B_Typ);
8596 Set_Etype (N, B_Typ);
8599 -- Generate warning for expressions like abs (x mod 2)
8601 if Warn_On_Redundant_Constructs
8602 and then Nkind (N) = N_Op_Abs
8604 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8606 if OK and then Hi >= Lo and then Lo >= 0 then
8608 ("?abs applied to known non-negative value has no effect", N);
8612 -- Deal with reference generation
8614 Check_Unset_Reference (R);
8615 Generate_Operator_Reference (N, B_Typ);
8618 -- Set overflow checking bit. Much cleverer code needed here eventually
8619 -- and perhaps the Resolve routines should be separated for the various
8620 -- arithmetic operations, since they will need different processing ???
8622 if Nkind (N) in N_Op then
8623 if not Overflow_Checks_Suppressed (Etype (N)) then
8624 Enable_Overflow_Check (N);
8628 -- Generate warning for expressions like -5 mod 3 for integers. No need
8629 -- to worry in the floating-point case, since parens do not affect the
8630 -- result so there is no point in giving in a warning.
8633 Norig : constant Node_Id := Original_Node (N);
8642 if Warn_On_Questionable_Missing_Parens
8643 and then Comes_From_Source (Norig)
8644 and then Is_Integer_Type (Typ)
8645 and then Nkind (Norig) = N_Op_Minus
8647 Rorig := Original_Node (Right_Opnd (Norig));
8649 -- We are looking for cases where the right operand is not
8650 -- parenthesized, and is a binary operator, multiply, divide, or
8651 -- mod. These are the cases where the grouping can affect results.
8653 if Paren_Count (Rorig) = 0
8654 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8656 -- For mod, we always give the warning, since the value is
8657 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8658 -- -(5 mod 315)). But for the other cases, the only concern is
8659 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8660 -- overflows, but (-2) * 64 does not). So we try to give the
8661 -- message only when overflow is possible.
8663 if Nkind (Rorig) /= N_Op_Mod
8664 and then Compile_Time_Known_Value (R)
8666 Val := Expr_Value (R);
8668 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8669 HB := Expr_Value (Type_High_Bound (Typ));
8671 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8674 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8675 LB := Expr_Value (Type_Low_Bound (Typ));
8677 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8680 -- Note that the test below is deliberately excluding the
8681 -- largest negative number, since that is a potentially
8682 -- troublesome case (e.g. -2 * x, where the result is the
8683 -- largest negative integer has an overflow with 2 * x).
8685 if Val > LB and then Val <= HB then
8690 -- For the multiplication case, the only case we have to worry
8691 -- about is when (-a)*b is exactly the largest negative number
8692 -- so that -(a*b) can cause overflow. This can only happen if
8693 -- a is a power of 2, and more generally if any operand is a
8694 -- constant that is not a power of 2, then the parentheses
8695 -- cannot affect whether overflow occurs. We only bother to
8696 -- test the left most operand
8698 -- Loop looking at left operands for one that has known value
8701 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8702 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8703 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8705 -- Operand value of 0 or 1 skips warning
8710 -- Otherwise check power of 2, if power of 2, warn, if
8711 -- anything else, skip warning.
8714 while Lval /= 2 loop
8715 if Lval mod 2 = 1 then
8726 -- Keep looking at left operands
8728 Opnd := Left_Opnd (Opnd);
8731 -- For rem or "/" we can only have a problematic situation
8732 -- if the divisor has a value of minus one or one. Otherwise
8733 -- overflow is impossible (divisor > 1) or we have a case of
8734 -- division by zero in any case.
8736 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8737 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8738 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8743 -- If we fall through warning should be issued
8746 ("?unary minus expression should be parenthesized here!", N);
8750 end Resolve_Unary_Op;
8752 ----------------------------------
8753 -- Resolve_Unchecked_Expression --
8754 ----------------------------------
8756 procedure Resolve_Unchecked_Expression
8761 Resolve (Expression (N), Typ, Suppress => All_Checks);
8763 end Resolve_Unchecked_Expression;
8765 ---------------------------------------
8766 -- Resolve_Unchecked_Type_Conversion --
8767 ---------------------------------------
8769 procedure Resolve_Unchecked_Type_Conversion
8773 pragma Warnings (Off, Typ);
8775 Operand : constant Node_Id := Expression (N);
8776 Opnd_Type : constant Entity_Id := Etype (Operand);
8779 -- Resolve operand using its own type
8781 Resolve (Operand, Opnd_Type);
8782 Eval_Unchecked_Conversion (N);
8784 end Resolve_Unchecked_Type_Conversion;
8786 ------------------------------
8787 -- Rewrite_Operator_As_Call --
8788 ------------------------------
8790 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8791 Loc : constant Source_Ptr := Sloc (N);
8792 Actuals : constant List_Id := New_List;
8796 if Nkind (N) in N_Binary_Op then
8797 Append (Left_Opnd (N), Actuals);
8800 Append (Right_Opnd (N), Actuals);
8803 Make_Function_Call (Sloc => Loc,
8804 Name => New_Occurrence_Of (Nam, Loc),
8805 Parameter_Associations => Actuals);
8807 Preserve_Comes_From_Source (New_N, N);
8808 Preserve_Comes_From_Source (Name (New_N), N);
8810 Set_Etype (N, Etype (Nam));
8811 end Rewrite_Operator_As_Call;
8813 ------------------------------
8814 -- Rewrite_Renamed_Operator --
8815 ------------------------------
8817 procedure Rewrite_Renamed_Operator
8822 Nam : constant Name_Id := Chars (Op);
8823 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8827 -- Rewrite the operator node using the real operator, not its renaming.
8828 -- Exclude user-defined intrinsic operations of the same name, which are
8829 -- treated separately and rewritten as calls.
8831 if Ekind (Op) /= E_Function
8832 or else Chars (N) /= Nam
8834 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8835 Set_Chars (Op_Node, Nam);
8836 Set_Etype (Op_Node, Etype (N));
8837 Set_Entity (Op_Node, Op);
8838 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8840 -- Indicate that both the original entity and its renaming are
8841 -- referenced at this point.
8843 Generate_Reference (Entity (N), N);
8844 Generate_Reference (Op, N);
8847 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8850 Rewrite (N, Op_Node);
8852 -- If the context type is private, add the appropriate conversions
8853 -- so that the operator is applied to the full view. This is done
8854 -- in the routines that resolve intrinsic operators,
8856 if Is_Intrinsic_Subprogram (Op)
8857 and then Is_Private_Type (Typ)
8860 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8861 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8862 Resolve_Intrinsic_Operator (N, Typ);
8864 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8865 Resolve_Intrinsic_Unary_Operator (N, Typ);
8872 elsif Ekind (Op) = E_Function
8873 and then Is_Intrinsic_Subprogram (Op)
8875 -- Operator renames a user-defined operator of the same name. Use
8876 -- the original operator in the node, which is the one that Gigi
8880 Set_Is_Overloaded (N, False);
8882 end Rewrite_Renamed_Operator;
8884 -----------------------
8885 -- Set_Slice_Subtype --
8886 -----------------------
8888 -- Build an implicit subtype declaration to represent the type delivered
8889 -- by the slice. This is an abbreviated version of an array subtype. We
8890 -- define an index subtype for the slice, using either the subtype name
8891 -- or the discrete range of the slice. To be consistent with index usage
8892 -- elsewhere, we create a list header to hold the single index. This list
8893 -- is not otherwise attached to the syntax tree.
8895 procedure Set_Slice_Subtype (N : Node_Id) is
8896 Loc : constant Source_Ptr := Sloc (N);
8897 Index_List : constant List_Id := New_List;
8899 Index_Subtype : Entity_Id;
8900 Index_Type : Entity_Id;
8901 Slice_Subtype : Entity_Id;
8902 Drange : constant Node_Id := Discrete_Range (N);
8905 if Is_Entity_Name (Drange) then
8906 Index_Subtype := Entity (Drange);
8909 -- We force the evaluation of a range. This is definitely needed in
8910 -- the renamed case, and seems safer to do unconditionally. Note in
8911 -- any case that since we will create and insert an Itype referring
8912 -- to this range, we must make sure any side effect removal actions
8913 -- are inserted before the Itype definition.
8915 if Nkind (Drange) = N_Range then
8916 Force_Evaluation (Low_Bound (Drange));
8917 Force_Evaluation (High_Bound (Drange));
8920 Index_Type := Base_Type (Etype (Drange));
8922 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8924 Set_Scalar_Range (Index_Subtype, Drange);
8925 Set_Etype (Index_Subtype, Index_Type);
8926 Set_Size_Info (Index_Subtype, Index_Type);
8927 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8930 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8932 Index := New_Occurrence_Of (Index_Subtype, Loc);
8933 Set_Etype (Index, Index_Subtype);
8934 Append (Index, Index_List);
8936 Set_First_Index (Slice_Subtype, Index);
8937 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8938 Set_Is_Constrained (Slice_Subtype, True);
8940 Check_Compile_Time_Size (Slice_Subtype);
8942 -- The Etype of the existing Slice node is reset to this slice subtype.
8943 -- Its bounds are obtained from its first index.
8945 Set_Etype (N, Slice_Subtype);
8947 -- In the packed case, this must be immediately frozen
8949 -- Couldn't we always freeze here??? and if we did, then the above
8950 -- call to Check_Compile_Time_Size could be eliminated, which would
8951 -- be nice, because then that routine could be made private to Freeze.
8953 -- Why the test for In_Spec_Expression here ???
8955 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8956 Freeze_Itype (Slice_Subtype, N);
8959 end Set_Slice_Subtype;
8961 --------------------------------
8962 -- Set_String_Literal_Subtype --
8963 --------------------------------
8965 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8966 Loc : constant Source_Ptr := Sloc (N);
8967 Low_Bound : constant Node_Id :=
8968 Type_Low_Bound (Etype (First_Index (Typ)));
8969 Subtype_Id : Entity_Id;
8972 if Nkind (N) /= N_String_Literal then
8976 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8977 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8978 (String_Length (Strval (N))));
8979 Set_Etype (Subtype_Id, Base_Type (Typ));
8980 Set_Is_Constrained (Subtype_Id);
8981 Set_Etype (N, Subtype_Id);
8983 if Is_OK_Static_Expression (Low_Bound) then
8985 -- The low bound is set from the low bound of the corresponding
8986 -- index type. Note that we do not store the high bound in the
8987 -- string literal subtype, but it can be deduced if necessary
8988 -- from the length and the low bound.
8990 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8993 Set_String_Literal_Low_Bound
8994 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8995 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8997 -- Build bona fide subtype for the string, and wrap it in an
8998 -- unchecked conversion, because the backend expects the
8999 -- String_Literal_Subtype to have a static lower bound.
9002 Index_List : constant List_Id := New_List;
9003 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9004 High_Bound : constant Node_Id :=
9006 Left_Opnd => New_Copy_Tree (Low_Bound),
9008 Make_Integer_Literal (Loc,
9009 String_Length (Strval (N)) - 1));
9010 Array_Subtype : Entity_Id;
9011 Index_Subtype : Entity_Id;
9017 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9018 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
9019 Set_Scalar_Range (Index_Subtype, Drange);
9020 Set_Parent (Drange, N);
9021 Analyze_And_Resolve (Drange, Index_Type);
9023 -- In the context, the Index_Type may already have a constraint,
9024 -- so use common base type on string subtype. The base type may
9025 -- be used when generating attributes of the string, for example
9026 -- in the context of a slice assignment.
9028 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9029 Set_Size_Info (Index_Subtype, Index_Type);
9030 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9032 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9034 Index := New_Occurrence_Of (Index_Subtype, Loc);
9035 Set_Etype (Index, Index_Subtype);
9036 Append (Index, Index_List);
9038 Set_First_Index (Array_Subtype, Index);
9039 Set_Etype (Array_Subtype, Base_Type (Typ));
9040 Set_Is_Constrained (Array_Subtype, True);
9043 Make_Unchecked_Type_Conversion (Loc,
9044 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9045 Expression => Relocate_Node (N)));
9046 Set_Etype (N, Array_Subtype);
9049 end Set_String_Literal_Subtype;
9051 ------------------------------
9052 -- Simplify_Type_Conversion --
9053 ------------------------------
9055 procedure Simplify_Type_Conversion (N : Node_Id) is
9057 if Nkind (N) = N_Type_Conversion then
9059 Operand : constant Node_Id := Expression (N);
9060 Target_Typ : constant Entity_Id := Etype (N);
9061 Opnd_Typ : constant Entity_Id := Etype (Operand);
9064 if Is_Floating_Point_Type (Opnd_Typ)
9066 (Is_Integer_Type (Target_Typ)
9067 or else (Is_Fixed_Point_Type (Target_Typ)
9068 and then Conversion_OK (N)))
9069 and then Nkind (Operand) = N_Attribute_Reference
9070 and then Attribute_Name (Operand) = Name_Truncation
9072 -- Special processing required if the conversion is the expression
9073 -- of a Truncation attribute reference. In this case we replace:
9075 -- ityp (ftyp'Truncation (x))
9081 -- with the Float_Truncate flag set, which is more efficient
9085 Relocate_Node (First (Expressions (Operand))));
9086 Set_Float_Truncate (N, True);
9090 end Simplify_Type_Conversion;
9092 -----------------------------
9093 -- Unique_Fixed_Point_Type --
9094 -----------------------------
9096 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
9097 T1 : Entity_Id := Empty;
9102 procedure Fixed_Point_Error;
9103 -- Give error messages for true ambiguity. Messages are posted on node
9104 -- N, and entities T1, T2 are the possible interpretations.
9106 -----------------------
9107 -- Fixed_Point_Error --
9108 -----------------------
9110 procedure Fixed_Point_Error is
9112 Error_Msg_N ("ambiguous universal_fixed_expression", N);
9113 Error_Msg_NE ("\\possible interpretation as}", N, T1);
9114 Error_Msg_NE ("\\possible interpretation as}", N, T2);
9115 end Fixed_Point_Error;
9117 -- Start of processing for Unique_Fixed_Point_Type
9120 -- The operations on Duration are visible, so Duration is always a
9121 -- possible interpretation.
9123 T1 := Standard_Duration;
9125 -- Look for fixed-point types in enclosing scopes
9127 Scop := Current_Scope;
9128 while Scop /= Standard_Standard loop
9129 T2 := First_Entity (Scop);
9130 while Present (T2) loop
9131 if Is_Fixed_Point_Type (T2)
9132 and then Current_Entity (T2) = T2
9133 and then Scope (Base_Type (T2)) = Scop
9135 if Present (T1) then
9146 Scop := Scope (Scop);
9149 -- Look for visible fixed type declarations in the context
9151 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
9152 while Present (Item) loop
9153 if Nkind (Item) = N_With_Clause then
9154 Scop := Entity (Name (Item));
9155 T2 := First_Entity (Scop);
9156 while Present (T2) loop
9157 if Is_Fixed_Point_Type (T2)
9158 and then Scope (Base_Type (T2)) = Scop
9159 and then (Is_Potentially_Use_Visible (T2)
9160 or else In_Use (T2))
9162 if Present (T1) then
9177 if Nkind (N) = N_Real_Literal then
9178 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9180 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9184 end Unique_Fixed_Point_Type;
9186 ----------------------
9187 -- Valid_Conversion --
9188 ----------------------
9190 function Valid_Conversion
9193 Operand : Node_Id) return Boolean
9195 Target_Type : constant Entity_Id := Base_Type (Target);
9196 Opnd_Type : Entity_Id := Etype (Operand);
9198 function Conversion_Check
9200 Msg : String) return Boolean;
9201 -- Little routine to post Msg if Valid is False, returns Valid value
9203 function Valid_Tagged_Conversion
9204 (Target_Type : Entity_Id;
9205 Opnd_Type : Entity_Id) return Boolean;
9206 -- Specifically test for validity of tagged conversions
9208 function Valid_Array_Conversion return Boolean;
9209 -- Check index and component conformance, and accessibility levels
9210 -- if the component types are anonymous access types (Ada 2005)
9212 ----------------------
9213 -- Conversion_Check --
9214 ----------------------
9216 function Conversion_Check
9218 Msg : String) return Boolean
9222 Error_Msg_N (Msg, Operand);
9226 end Conversion_Check;
9228 ----------------------------
9229 -- Valid_Array_Conversion --
9230 ----------------------------
9232 function Valid_Array_Conversion return Boolean
9234 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9235 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9237 Opnd_Index : Node_Id;
9238 Opnd_Index_Type : Entity_Id;
9240 Target_Comp_Type : constant Entity_Id :=
9241 Component_Type (Target_Type);
9242 Target_Comp_Base : constant Entity_Id :=
9243 Base_Type (Target_Comp_Type);
9245 Target_Index : Node_Id;
9246 Target_Index_Type : Entity_Id;
9249 -- Error if wrong number of dimensions
9252 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9255 ("incompatible number of dimensions for conversion", Operand);
9258 -- Number of dimensions matches
9261 -- Loop through indexes of the two arrays
9263 Target_Index := First_Index (Target_Type);
9264 Opnd_Index := First_Index (Opnd_Type);
9265 while Present (Target_Index) and then Present (Opnd_Index) loop
9266 Target_Index_Type := Etype (Target_Index);
9267 Opnd_Index_Type := Etype (Opnd_Index);
9269 -- Error if index types are incompatible
9271 if not (Is_Integer_Type (Target_Index_Type)
9272 and then Is_Integer_Type (Opnd_Index_Type))
9273 and then (Root_Type (Target_Index_Type)
9274 /= Root_Type (Opnd_Index_Type))
9277 ("incompatible index types for array conversion",
9282 Next_Index (Target_Index);
9283 Next_Index (Opnd_Index);
9286 -- If component types have same base type, all set
9288 if Target_Comp_Base = Opnd_Comp_Base then
9291 -- Here if base types of components are not the same. The only
9292 -- time this is allowed is if we have anonymous access types.
9294 -- The conversion of arrays of anonymous access types can lead
9295 -- to dangling pointers. AI-392 formalizes the accessibility
9296 -- checks that must be applied to such conversions to prevent
9297 -- out-of-scope references.
9300 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9302 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9303 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9305 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9307 if Type_Access_Level (Target_Type) <
9308 Type_Access_Level (Opnd_Type)
9310 if In_Instance_Body then
9311 Error_Msg_N ("?source array type " &
9312 "has deeper accessibility level than target", Operand);
9313 Error_Msg_N ("\?Program_Error will be raised at run time",
9316 Make_Raise_Program_Error (Sloc (N),
9317 Reason => PE_Accessibility_Check_Failed));
9318 Set_Etype (N, Target_Type);
9321 -- Conversion not allowed because of accessibility levels
9324 Error_Msg_N ("source array type " &
9325 "has deeper accessibility level than target", Operand);
9332 -- All other cases where component base types do not match
9336 ("incompatible component types for array conversion",
9341 -- Check that component subtypes statically match. For numeric
9342 -- types this means that both must be either constrained or
9343 -- unconstrained. For enumeration types the bounds must match.
9344 -- All of this is checked in Subtypes_Statically_Match.
9346 if not Subtypes_Statically_Match
9347 (Target_Comp_Type, Opnd_Comp_Type)
9350 ("component subtypes must statically match", Operand);
9356 end Valid_Array_Conversion;
9358 -----------------------------
9359 -- Valid_Tagged_Conversion --
9360 -----------------------------
9362 function Valid_Tagged_Conversion
9363 (Target_Type : Entity_Id;
9364 Opnd_Type : Entity_Id) return Boolean
9367 -- Upward conversions are allowed (RM 4.6(22))
9369 if Covers (Target_Type, Opnd_Type)
9370 or else Is_Ancestor (Target_Type, Opnd_Type)
9374 -- Downward conversion are allowed if the operand is class-wide
9377 elsif Is_Class_Wide_Type (Opnd_Type)
9378 and then Covers (Opnd_Type, Target_Type)
9382 elsif Covers (Opnd_Type, Target_Type)
9383 or else Is_Ancestor (Opnd_Type, Target_Type)
9386 Conversion_Check (False,
9387 "downward conversion of tagged objects not allowed");
9389 -- Ada 2005 (AI-251): The conversion to/from interface types is
9392 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9395 -- If the operand is a class-wide type obtained through a limited_
9396 -- with clause, and the context includes the non-limited view, use
9397 -- it to determine whether the conversion is legal.
9399 elsif Is_Class_Wide_Type (Opnd_Type)
9400 and then From_With_Type (Opnd_Type)
9401 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9402 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9406 elsif Is_Access_Type (Opnd_Type)
9407 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9413 ("invalid tagged conversion, not compatible with}",
9414 N, First_Subtype (Opnd_Type));
9417 end Valid_Tagged_Conversion;
9419 -- Start of processing for Valid_Conversion
9422 Check_Parameterless_Call (Operand);
9424 if Is_Overloaded (Operand) then
9433 -- Remove procedure calls, which syntactically cannot appear in
9434 -- this context, but which cannot be removed by type checking,
9435 -- because the context does not impose a type.
9437 -- When compiling for VMS, spurious ambiguities can be produced
9438 -- when arithmetic operations have a literal operand and return
9439 -- System.Address or a descendant of it. These ambiguities are
9440 -- otherwise resolved by the context, but for conversions there
9441 -- is no context type and the removal of the spurious operations
9442 -- must be done explicitly here.
9444 -- The node may be labelled overloaded, but still contain only
9445 -- one interpretation because others were discarded in previous
9446 -- filters. If this is the case, retain the single interpretation
9449 Get_First_Interp (Operand, I, It);
9450 Opnd_Type := It.Typ;
9451 Get_Next_Interp (I, It);
9454 and then Opnd_Type /= Standard_Void_Type
9456 -- More than one candidate interpretation is available
9458 Get_First_Interp (Operand, I, It);
9459 while Present (It.Typ) loop
9460 if It.Typ = Standard_Void_Type then
9464 if Present (System_Aux_Id)
9465 and then Is_Descendent_Of_Address (It.Typ)
9470 Get_Next_Interp (I, It);
9474 Get_First_Interp (Operand, I, It);
9479 Error_Msg_N ("illegal operand in conversion", Operand);
9483 Get_Next_Interp (I, It);
9485 if Present (It.Typ) then
9487 It1 := Disambiguate (Operand, I1, I, Any_Type);
9489 if It1 = No_Interp then
9490 Error_Msg_N ("ambiguous operand in conversion", Operand);
9492 Error_Msg_Sloc := Sloc (It.Nam);
9493 Error_Msg_N -- CODEFIX
9494 ("\\possible interpretation#!", Operand);
9496 Error_Msg_Sloc := Sloc (N1);
9497 Error_Msg_N -- CODEFIX
9498 ("\\possible interpretation#!", Operand);
9504 Set_Etype (Operand, It1.Typ);
9505 Opnd_Type := It1.Typ;
9511 if Is_Numeric_Type (Target_Type) then
9513 -- A universal fixed expression can be converted to any numeric type
9515 if Opnd_Type = Universal_Fixed then
9518 -- Also no need to check when in an instance or inlined body, because
9519 -- the legality has been established when the template was analyzed.
9520 -- Furthermore, numeric conversions may occur where only a private
9521 -- view of the operand type is visible at the instantiation point.
9522 -- This results in a spurious error if we check that the operand type
9523 -- is a numeric type.
9525 -- Note: in a previous version of this unit, the following tests were
9526 -- applied only for generated code (Comes_From_Source set to False),
9527 -- but in fact the test is required for source code as well, since
9528 -- this situation can arise in source code.
9530 elsif In_Instance or else In_Inlined_Body then
9533 -- Otherwise we need the conversion check
9536 return Conversion_Check
9537 (Is_Numeric_Type (Opnd_Type),
9538 "illegal operand for numeric conversion");
9543 elsif Is_Array_Type (Target_Type) then
9544 if not Is_Array_Type (Opnd_Type)
9545 or else Opnd_Type = Any_Composite
9546 or else Opnd_Type = Any_String
9549 ("illegal operand for array conversion", Operand);
9552 return Valid_Array_Conversion;
9555 -- Ada 2005 (AI-251): Anonymous access types where target references an
9558 elsif (Ekind (Target_Type) = E_General_Access_Type
9560 Ekind (Target_Type) = E_Anonymous_Access_Type)
9561 and then Is_Interface (Directly_Designated_Type (Target_Type))
9563 -- Check the static accessibility rule of 4.6(17). Note that the
9564 -- check is not enforced when within an instance body, since the
9565 -- RM requires such cases to be caught at run time.
9567 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9568 if Type_Access_Level (Opnd_Type) >
9569 Type_Access_Level (Target_Type)
9571 -- In an instance, this is a run-time check, but one we know
9572 -- will fail, so generate an appropriate warning. The raise
9573 -- will be generated by Expand_N_Type_Conversion.
9575 if In_Instance_Body then
9577 ("?cannot convert local pointer to non-local access type",
9580 ("\?Program_Error will be raised at run time", Operand);
9583 ("cannot convert local pointer to non-local access type",
9588 -- Special accessibility checks are needed in the case of access
9589 -- discriminants declared for a limited type.
9591 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9592 and then not Is_Local_Anonymous_Access (Opnd_Type)
9594 -- When the operand is a selected access discriminant the check
9595 -- needs to be made against the level of the object denoted by
9596 -- the prefix of the selected name (Object_Access_Level handles
9597 -- checking the prefix of the operand for this case).
9599 if Nkind (Operand) = N_Selected_Component
9600 and then Object_Access_Level (Operand) >
9601 Type_Access_Level (Target_Type)
9603 -- In an instance, this is a run-time check, but one we know
9604 -- will fail, so generate an appropriate warning. The raise
9605 -- will be generated by Expand_N_Type_Conversion.
9607 if In_Instance_Body then
9609 ("?cannot convert access discriminant to non-local" &
9610 " access type", Operand);
9612 ("\?Program_Error will be raised at run time", Operand);
9615 ("cannot convert access discriminant to non-local" &
9616 " access type", Operand);
9621 -- The case of a reference to an access discriminant from
9622 -- within a limited type declaration (which will appear as
9623 -- a discriminal) is always illegal because the level of the
9624 -- discriminant is considered to be deeper than any (nameable)
9627 if Is_Entity_Name (Operand)
9628 and then not Is_Local_Anonymous_Access (Opnd_Type)
9629 and then (Ekind (Entity (Operand)) = E_In_Parameter
9630 or else Ekind (Entity (Operand)) = E_Constant)
9631 and then Present (Discriminal_Link (Entity (Operand)))
9634 ("discriminant has deeper accessibility level than target",
9643 -- General and anonymous access types
9645 elsif (Ekind (Target_Type) = E_General_Access_Type
9646 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9649 (Is_Access_Type (Opnd_Type)
9650 and then Ekind (Opnd_Type) /=
9651 E_Access_Subprogram_Type
9652 and then Ekind (Opnd_Type) /=
9653 E_Access_Protected_Subprogram_Type,
9654 "must be an access-to-object type")
9656 if Is_Access_Constant (Opnd_Type)
9657 and then not Is_Access_Constant (Target_Type)
9660 ("access-to-constant operand type not allowed", Operand);
9664 -- Check the static accessibility rule of 4.6(17). Note that the
9665 -- check is not enforced when within an instance body, since the RM
9666 -- requires such cases to be caught at run time.
9668 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9669 or else Is_Local_Anonymous_Access (Target_Type)
9671 if Type_Access_Level (Opnd_Type)
9672 > Type_Access_Level (Target_Type)
9674 -- In an instance, this is a run-time check, but one we know
9675 -- will fail, so generate an appropriate warning. The raise
9676 -- will be generated by Expand_N_Type_Conversion.
9678 if In_Instance_Body then
9680 ("?cannot convert local pointer to non-local access type",
9683 ("\?Program_Error will be raised at run time", Operand);
9686 -- Avoid generation of spurious error message
9688 if not Error_Posted (N) then
9690 ("cannot convert local pointer to non-local access type",
9697 -- Special accessibility checks are needed in the case of access
9698 -- discriminants declared for a limited type.
9700 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9701 and then not Is_Local_Anonymous_Access (Opnd_Type)
9704 -- When the operand is a selected access discriminant the check
9705 -- needs to be made against the level of the object denoted by
9706 -- the prefix of the selected name (Object_Access_Level handles
9707 -- checking the prefix of the operand for this case).
9709 if Nkind (Operand) = N_Selected_Component
9710 and then Object_Access_Level (Operand) >
9711 Type_Access_Level (Target_Type)
9713 -- In an instance, this is a run-time check, but one we know
9714 -- will fail, so generate an appropriate warning. The raise
9715 -- will be generated by Expand_N_Type_Conversion.
9717 if In_Instance_Body then
9719 ("?cannot convert access discriminant to non-local" &
9720 " access type", Operand);
9722 ("\?Program_Error will be raised at run time",
9727 ("cannot convert access discriminant to non-local" &
9728 " access type", Operand);
9733 -- The case of a reference to an access discriminant from
9734 -- within a limited type declaration (which will appear as
9735 -- a discriminal) is always illegal because the level of the
9736 -- discriminant is considered to be deeper than any (nameable)
9739 if Is_Entity_Name (Operand)
9740 and then (Ekind (Entity (Operand)) = E_In_Parameter
9741 or else Ekind (Entity (Operand)) = E_Constant)
9742 and then Present (Discriminal_Link (Entity (Operand)))
9745 ("discriminant has deeper accessibility level than target",
9752 -- In the presence of limited_with clauses we have to use non-limited
9753 -- views, if available.
9755 Check_Limited : declare
9756 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9757 -- Helper function to handle limited views
9759 --------------------------
9760 -- Full_Designated_Type --
9761 --------------------------
9763 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9764 Desig : constant Entity_Id := Designated_Type (T);
9767 -- Handle the limited view of a type
9769 if Is_Incomplete_Type (Desig)
9770 and then From_With_Type (Desig)
9771 and then Present (Non_Limited_View (Desig))
9773 return Available_View (Desig);
9777 end Full_Designated_Type;
9779 -- Local Declarations
9781 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9782 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9784 Same_Base : constant Boolean :=
9785 Base_Type (Target) = Base_Type (Opnd);
9787 -- Start of processing for Check_Limited
9790 if Is_Tagged_Type (Target) then
9791 return Valid_Tagged_Conversion (Target, Opnd);
9794 if not Same_Base then
9796 ("target designated type not compatible with }",
9797 N, Base_Type (Opnd));
9800 -- Ada 2005 AI-384: legality rule is symmetric in both
9801 -- designated types. The conversion is legal (with possible
9802 -- constraint check) if either designated type is
9805 elsif Subtypes_Statically_Match (Target, Opnd)
9807 (Has_Discriminants (Target)
9809 (not Is_Constrained (Opnd)
9810 or else not Is_Constrained (Target)))
9812 -- Special case, if Value_Size has been used to make the
9813 -- sizes different, the conversion is not allowed even
9814 -- though the subtypes statically match.
9816 if Known_Static_RM_Size (Target)
9817 and then Known_Static_RM_Size (Opnd)
9818 and then RM_Size (Target) /= RM_Size (Opnd)
9821 ("target designated subtype not compatible with }",
9824 ("\because sizes of the two designated subtypes differ",
9828 -- Normal case where conversion is allowed
9836 ("target designated subtype not compatible with }",
9843 -- Access to subprogram types. If the operand is an access parameter,
9844 -- the type has a deeper accessibility that any master, and cannot
9845 -- be assigned. We must make an exception if the conversion is part
9846 -- of an assignment and the target is the return object of an extended
9847 -- return statement, because in that case the accessibility check
9848 -- takes place after the return.
9850 elsif Is_Access_Subprogram_Type (Target_Type)
9851 and then No (Corresponding_Remote_Type (Opnd_Type))
9853 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9854 and then Is_Entity_Name (Operand)
9855 and then Ekind (Entity (Operand)) = E_In_Parameter
9857 (Nkind (Parent (N)) /= N_Assignment_Statement
9858 or else not Is_Entity_Name (Name (Parent (N)))
9859 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9862 ("illegal attempt to store anonymous access to subprogram",
9865 ("\value has deeper accessibility than any master " &
9870 ("\use named access type for& instead of access parameter",
9871 Operand, Entity (Operand));
9874 -- Check that the designated types are subtype conformant
9876 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9877 Old_Id => Designated_Type (Opnd_Type),
9880 -- Check the static accessibility rule of 4.6(20)
9882 if Type_Access_Level (Opnd_Type) >
9883 Type_Access_Level (Target_Type)
9886 ("operand type has deeper accessibility level than target",
9889 -- Check that if the operand type is declared in a generic body,
9890 -- then the target type must be declared within that same body
9891 -- (enforces last sentence of 4.6(20)).
9893 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9895 O_Gen : constant Node_Id :=
9896 Enclosing_Generic_Body (Opnd_Type);
9901 T_Gen := Enclosing_Generic_Body (Target_Type);
9902 while Present (T_Gen) and then T_Gen /= O_Gen loop
9903 T_Gen := Enclosing_Generic_Body (T_Gen);
9906 if T_Gen /= O_Gen then
9908 ("target type must be declared in same generic body"
9909 & " as operand type", N);
9916 -- Remote subprogram access types
9918 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9919 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9921 -- It is valid to convert from one RAS type to another provided
9922 -- that their specification statically match.
9924 Check_Subtype_Conformant
9926 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9928 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9933 -- If both are tagged types, check legality of view conversions
9935 elsif Is_Tagged_Type (Target_Type)
9936 and then Is_Tagged_Type (Opnd_Type)
9938 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9940 -- Types derived from the same root type are convertible
9942 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9945 -- In an instance or an inlined body, there may be inconsistent
9946 -- views of the same type, or of types derived from a common root.
9948 elsif (In_Instance or In_Inlined_Body)
9950 Root_Type (Underlying_Type (Target_Type)) =
9951 Root_Type (Underlying_Type (Opnd_Type))
9955 -- Special check for common access type error case
9957 elsif Ekind (Target_Type) = E_Access_Type
9958 and then Is_Access_Type (Opnd_Type)
9960 Error_Msg_N ("target type must be general access type!", N);
9961 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9965 Error_Msg_NE ("invalid conversion, not compatible with }",
9969 end Valid_Conversion;