1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Itypes; use Itypes;
42 with Lib.Xref; use Lib.Xref;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
45 with Nlists; use Nlists;
47 with Output; use Output;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
52 with Sem_Aux; use Sem_Aux;
53 with Sem_Aggr; use Sem_Aggr;
54 with Sem_Attr; use Sem_Attr;
55 with Sem_Cat; use Sem_Cat;
56 with Sem_Ch4; use Sem_Ch4;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch13; use Sem_Ch13;
60 with Sem_Dim; use Sem_Dim;
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 Targparm; use Targparm;
69 with Sem_Type; use Sem_Type;
70 with Sem_Warn; use Sem_Warn;
71 with Sinfo; use Sinfo;
72 with Sinfo.CN; use Sinfo.CN;
73 with Snames; use Snames;
74 with Stand; use Stand;
75 with Stringt; use Stringt;
76 with Style; use Style;
77 with Tbuild; use Tbuild;
78 with Uintp; use Uintp;
79 with Urealp; use Urealp;
81 package body Sem_Res is
83 -----------------------
84 -- Local Subprograms --
85 -----------------------
87 -- Second pass (top-down) type checking and overload resolution procedures
88 -- Typ is the type required by context. These procedures propagate the type
89 -- information recursively to the descendants of N. If the node is not
90 -- overloaded, its Etype is established in the first pass. If overloaded,
91 -- the Resolve routines set the correct type. For arith. operators, the
92 -- Etype is the base type of the context.
94 -- Note that Resolve_Attribute is separated off in Sem_Attr
96 function Bad_Unordered_Enumeration_Reference
98 T : Entity_Id) return Boolean;
99 -- Node N contains a potentially dubious reference to type T, either an
100 -- explicit comparison, or an explicit range. This function returns True
101 -- if the type T is an enumeration type for which No pragma Order has been
102 -- given, and the reference N is not in the same extended source unit as
103 -- the declaration of T.
105 procedure Check_Discriminant_Use (N : Node_Id);
106 -- Enforce the restrictions on the use of discriminants when constraining
107 -- a component of a discriminated type (record or concurrent type).
109 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
110 -- Given a node for an operator associated with type T, check that
111 -- the operator is visible. Operators all of whose operands are
112 -- universal must be checked for visibility during resolution
113 -- because their type is not determinable based on their operands.
115 procedure Check_Fully_Declared_Prefix
118 -- Check that the type of the prefix of a dereference is not incomplete
120 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
121 -- Given a call node, N, which is known to occur immediately within the
122 -- subprogram being called, determines whether it is a detectable case of
123 -- an infinite recursion, and if so, outputs appropriate messages. Returns
124 -- True if an infinite recursion is detected, and False otherwise.
126 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
127 -- If the type of the object being initialized uses the secondary stack
128 -- directly or indirectly, create a transient scope for the call to the
129 -- init proc. This is because we do not create transient scopes for the
130 -- initialization of individual components within the init proc itself.
131 -- Could be optimized away perhaps?
133 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
134 -- N is the node for a logical operator. If the operator is predefined, and
135 -- the root type of the operands is Standard.Boolean, then a check is made
136 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
137 -- the style check for Style_Check_Boolean_And_Or.
139 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
211 function Operator_Kind
213 Is_Binary : Boolean) return Node_Kind;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
236 -- Ditto, for unary operators (arithmetic ones and "not" on signed
237 -- integer types for VMS).
239 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
240 -- If an operator node resolves to a call to a user-defined operator,
241 -- rewrite the node as a function call.
243 procedure Make_Call_Into_Operator
247 -- Inverse transformation: if an operator is given in functional notation,
248 -- then after resolving the node, transform into an operator node, so
249 -- that operands are resolved properly. Recall that predefined operators
250 -- do not have a full signature and special resolution rules apply.
252 procedure Rewrite_Renamed_Operator
256 -- An operator can rename another, e.g. in an instantiation. In that
257 -- case, the proper operator node must be constructed and resolved.
259 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
260 -- The String_Literal_Subtype is built for all strings that are not
261 -- operands of a static concatenation operation. If the argument is
262 -- not a N_String_Literal node, then the call has no effect.
264 procedure Set_Slice_Subtype (N : Node_Id);
265 -- Build subtype of array type, with the range specified by the slice
267 procedure Simplify_Type_Conversion (N : Node_Id);
268 -- Called after N has been resolved and evaluated, but before range checks
269 -- have been applied. Currently simplifies a combination of floating-point
270 -- to integer conversion and Truncation attribute.
272 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
273 -- A universal_fixed expression in an universal context is unambiguous if
274 -- there is only one applicable fixed point type. Determining whether there
275 -- is only one requires a search over all visible entities, and happens
276 -- only in very pathological cases (see 6115-006).
278 -------------------------
279 -- Ambiguous_Character --
280 -------------------------
282 procedure Ambiguous_Character (C : Node_Id) is
286 if Nkind (C) = N_Character_Literal then
287 Error_Msg_N ("ambiguous character literal", C);
289 -- First the ones in Standard
291 Error_Msg_N ("\\possible interpretation: Character!", C);
292 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
294 -- Include Wide_Wide_Character in Ada 2005 mode
296 if Ada_Version >= Ada_2005 then
297 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
300 -- Now any other types that match
302 E := Current_Entity (C);
303 while Present (E) loop
304 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
308 end Ambiguous_Character;
310 -------------------------
311 -- Analyze_And_Resolve --
312 -------------------------
314 procedure Analyze_And_Resolve (N : Node_Id) is
318 end Analyze_And_Resolve;
320 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
324 end Analyze_And_Resolve;
326 -- Version withs check(s) suppressed
328 procedure Analyze_And_Resolve
333 Scop : constant Entity_Id := Current_Scope;
336 if Suppress = All_Checks then
338 Svg : constant Suppress_Array := Scope_Suppress;
340 Scope_Suppress := (others => True);
341 Analyze_And_Resolve (N, Typ);
342 Scope_Suppress := Svg;
347 Svg : constant Boolean := Scope_Suppress (Suppress);
350 Scope_Suppress (Suppress) := True;
351 Analyze_And_Resolve (N, Typ);
352 Scope_Suppress (Suppress) := Svg;
356 if Current_Scope /= Scop
357 and then Scope_Is_Transient
359 -- This can only happen if a transient scope was created for an inner
360 -- expression, which will be removed upon completion of the analysis
361 -- of an enclosing construct. The transient scope must have the
362 -- suppress status of the enclosing environment, not of this Analyze
365 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
368 end Analyze_And_Resolve;
370 procedure Analyze_And_Resolve
374 Scop : constant Entity_Id := Current_Scope;
377 if Suppress = All_Checks then
379 Svg : constant Suppress_Array := Scope_Suppress;
381 Scope_Suppress := (others => True);
382 Analyze_And_Resolve (N);
383 Scope_Suppress := Svg;
388 Svg : constant Boolean := Scope_Suppress (Suppress);
391 Scope_Suppress (Suppress) := True;
392 Analyze_And_Resolve (N);
393 Scope_Suppress (Suppress) := Svg;
397 if Current_Scope /= Scop
398 and then Scope_Is_Transient
400 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
403 end Analyze_And_Resolve;
405 ----------------------------------------
406 -- Bad_Unordered_Enumeration_Reference --
407 ----------------------------------------
409 function Bad_Unordered_Enumeration_Reference
411 T : Entity_Id) return Boolean
414 return Is_Enumeration_Type (T)
415 and then Comes_From_Source (N)
416 and then Warn_On_Unordered_Enumeration_Type
417 and then not Has_Pragma_Ordered (T)
418 and then not In_Same_Extended_Unit (N, T);
419 end Bad_Unordered_Enumeration_Reference;
421 ----------------------------
422 -- Check_Discriminant_Use --
423 ----------------------------
425 procedure Check_Discriminant_Use (N : Node_Id) is
426 PN : constant Node_Id := Parent (N);
427 Disc : constant Entity_Id := Entity (N);
432 -- Any use in a spec-expression is legal
434 if In_Spec_Expression then
437 elsif Nkind (PN) = N_Range then
439 -- Discriminant cannot be used to constrain a scalar type
443 if Nkind (P) = N_Range_Constraint
444 and then Nkind (Parent (P)) = N_Subtype_Indication
445 and then Nkind (Parent (Parent (P))) = N_Component_Definition
447 Error_Msg_N ("discriminant cannot constrain scalar type", N);
449 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
451 -- The following check catches the unusual case where a
452 -- discriminant appears within an index constraint that is part of
453 -- a larger expression within a constraint on a component, e.g. "C
454 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
455 -- of record components, and note that a similar check should also
456 -- apply in the case of discriminant constraints below. ???
458 -- Note that the check for N_Subtype_Declaration below is to
459 -- detect the valid use of discriminants in the constraints of a
460 -- subtype declaration when this subtype declaration appears
461 -- inside the scope of a record type (which is syntactically
462 -- illegal, but which may be created as part of derived type
463 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
466 if Ekind (Current_Scope) = E_Record_Type
467 and then Scope (Disc) = Current_Scope
469 (Nkind (Parent (P)) = N_Subtype_Indication
471 Nkind_In (Parent (Parent (P)), N_Component_Definition,
472 N_Subtype_Declaration)
473 and then Paren_Count (N) = 0)
476 ("discriminant must appear alone in component constraint", N);
480 -- Detect a common error:
482 -- type R (D : Positive := 100) is record
483 -- Name : String (1 .. D);
486 -- The default value causes an object of type R to be allocated
487 -- with room for Positive'Last characters. The RM does not mandate
488 -- the allocation of the maximum size, but that is what GNAT does
489 -- so we should warn the programmer that there is a problem.
491 Check_Large : declare
497 function Large_Storage_Type (T : Entity_Id) return Boolean;
498 -- Return True if type T has a large enough range that any
499 -- array whose index type covered the whole range of the type
500 -- would likely raise Storage_Error.
502 ------------------------
503 -- Large_Storage_Type --
504 ------------------------
506 function Large_Storage_Type (T : Entity_Id) return Boolean is
508 -- The type is considered large if its bounds are known at
509 -- compile time and if it requires at least as many bits as
510 -- a Positive to store the possible values.
512 return Compile_Time_Known_Value (Type_Low_Bound (T))
513 and then Compile_Time_Known_Value (Type_High_Bound (T))
515 Minimum_Size (T, Biased => True) >=
516 RM_Size (Standard_Positive);
517 end Large_Storage_Type;
519 -- Start of processing for Check_Large
522 -- Check that the Disc has a large range
524 if not Large_Storage_Type (Etype (Disc)) then
528 -- If the enclosing type is limited, we allocate only the
529 -- default value, not the maximum, and there is no need for
532 if Is_Limited_Type (Scope (Disc)) then
536 -- Check that it is the high bound
538 if N /= High_Bound (PN)
539 or else No (Discriminant_Default_Value (Disc))
544 -- Check the array allows a large range at this bound. First
549 if Nkind (SI) /= N_Subtype_Indication then
553 T := Entity (Subtype_Mark (SI));
555 if not Is_Array_Type (T) then
559 -- Next, find the dimension
561 TB := First_Index (T);
562 CB := First (Constraints (P));
564 and then Present (TB)
565 and then Present (CB)
576 -- Now, check the dimension has a large range
578 if not Large_Storage_Type (Etype (TB)) then
582 -- Warn about the danger
585 ("?creation of & object may raise Storage_Error!",
594 -- Legal case is in index or discriminant constraint
596 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
597 N_Discriminant_Association)
599 if Paren_Count (N) > 0 then
601 ("discriminant in constraint must appear alone", N);
603 elsif Nkind (N) = N_Expanded_Name
604 and then Comes_From_Source (N)
607 ("discriminant must appear alone as a direct name", N);
612 -- Otherwise, context is an expression. It should not be within (i.e. a
613 -- subexpression of) a constraint for a component.
618 while not Nkind_In (P, N_Component_Declaration,
619 N_Subtype_Indication,
627 -- If the discriminant is used in an expression that is a bound of a
628 -- scalar type, an Itype is created and the bounds are attached to
629 -- its range, not to the original subtype indication. Such use is of
630 -- course a double fault.
632 if (Nkind (P) = N_Subtype_Indication
633 and then Nkind_In (Parent (P), N_Component_Definition,
634 N_Derived_Type_Definition)
635 and then D = Constraint (P))
637 -- The constraint itself may be given by a subtype indication,
638 -- rather than by a more common discrete range.
640 or else (Nkind (P) = N_Subtype_Indication
642 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
643 or else Nkind (P) = N_Entry_Declaration
644 or else Nkind (D) = N_Defining_Identifier
647 ("discriminant in constraint must appear alone", N);
650 end Check_Discriminant_Use;
652 --------------------------------
653 -- Check_For_Visible_Operator --
654 --------------------------------
656 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
658 if Is_Invisible_Operator (N, T) then
659 Error_Msg_NE -- CODEFIX
660 ("operator for} is not directly visible!", N, First_Subtype (T));
661 Error_Msg_N -- CODEFIX
662 ("use clause would make operation legal!", N);
664 end Check_For_Visible_Operator;
666 ----------------------------------
667 -- Check_Fully_Declared_Prefix --
668 ----------------------------------
670 procedure Check_Fully_Declared_Prefix
675 -- Check that the designated type of the prefix of a dereference is
676 -- not an incomplete type. This cannot be done unconditionally, because
677 -- dereferences of private types are legal in default expressions. This
678 -- case is taken care of in Check_Fully_Declared, called below. There
679 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
681 -- This consideration also applies to similar checks for allocators,
682 -- qualified expressions, and type conversions.
684 -- An additional exception concerns other per-object expressions that
685 -- are not directly related to component declarations, in particular
686 -- representation pragmas for tasks. These will be per-object
687 -- expressions if they depend on discriminants or some global entity.
688 -- If the task has access discriminants, the designated type may be
689 -- incomplete at the point the expression is resolved. This resolution
690 -- takes place within the body of the initialization procedure, where
691 -- the discriminant is replaced by its discriminal.
693 if Is_Entity_Name (Pref)
694 and then Ekind (Entity (Pref)) = E_In_Parameter
698 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
699 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
700 -- Analyze_Object_Renaming, and Freeze_Entity.
702 elsif Ada_Version >= Ada_2005
703 and then Is_Entity_Name (Pref)
704 and then Is_Access_Type (Etype (Pref))
705 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
707 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
711 Check_Fully_Declared (Typ, Parent (Pref));
713 end Check_Fully_Declared_Prefix;
715 ------------------------------
716 -- Check_Infinite_Recursion --
717 ------------------------------
719 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
723 function Same_Argument_List return Boolean;
724 -- Check whether list of actuals is identical to list of formals of
725 -- called function (which is also the enclosing scope).
727 ------------------------
728 -- Same_Argument_List --
729 ------------------------
731 function Same_Argument_List return Boolean is
737 if not Is_Entity_Name (Name (N)) then
740 Subp := Entity (Name (N));
743 F := First_Formal (Subp);
744 A := First_Actual (N);
745 while Present (F) and then Present (A) loop
746 if not Is_Entity_Name (A)
747 or else Entity (A) /= F
757 end Same_Argument_List;
759 -- Start of processing for Check_Infinite_Recursion
762 -- Special case, if this is a procedure call and is a call to the
763 -- current procedure with the same argument list, then this is for
764 -- sure an infinite recursion and we insert a call to raise SE.
766 if Is_List_Member (N)
767 and then List_Length (List_Containing (N)) = 1
768 and then Same_Argument_List
771 P : constant Node_Id := Parent (N);
773 if Nkind (P) = N_Handled_Sequence_Of_Statements
774 and then Nkind (Parent (P)) = N_Subprogram_Body
775 and then Is_Empty_List (Declarations (Parent (P)))
777 Error_Msg_N ("!?infinite recursion", N);
778 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
780 Make_Raise_Storage_Error (Sloc (N),
781 Reason => SE_Infinite_Recursion));
787 -- If not that special case, search up tree, quitting if we reach a
788 -- construct (e.g. a conditional) that tells us that this is not a
789 -- case for an infinite recursion warning.
795 -- If no parent, then we were not inside a subprogram, this can for
796 -- example happen when processing certain pragmas in a spec. Just
797 -- return False in this case.
803 -- Done if we get to subprogram body, this is definitely an infinite
804 -- recursion case if we did not find anything to stop us.
806 exit when Nkind (P) = N_Subprogram_Body;
808 -- If appearing in conditional, result is false
810 if Nkind_In (P, N_Or_Else,
814 N_Conditional_Expression,
819 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
820 and then C /= First (Statements (P))
822 -- If the call is the expression of a return statement and the
823 -- actuals are identical to the formals, it's worth a warning.
824 -- However, we skip this if there is an immediately preceding
825 -- raise statement, since the call is never executed.
827 -- Furthermore, this corresponds to a common idiom:
829 -- function F (L : Thing) return Boolean is
831 -- raise Program_Error;
835 -- for generating a stub function
837 if Nkind (Parent (N)) = N_Simple_Return_Statement
838 and then Same_Argument_List
840 exit when not Is_List_Member (Parent (N));
842 -- OK, return statement is in a statement list, look for raise
848 -- Skip past N_Freeze_Entity nodes generated by expansion
850 Nod := Prev (Parent (N));
852 and then Nkind (Nod) = N_Freeze_Entity
857 -- If no raise statement, give warning
859 exit when Nkind (Nod) /= N_Raise_Statement
861 (Nkind (Nod) not in N_Raise_xxx_Error
862 or else Present (Condition (Nod)));
873 Error_Msg_N ("!?possible infinite recursion", N);
874 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
877 end Check_Infinite_Recursion;
879 -------------------------------
880 -- Check_Initialization_Call --
881 -------------------------------
883 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
884 Typ : constant Entity_Id := Etype (First_Formal (Nam));
886 function Uses_SS (T : Entity_Id) return Boolean;
887 -- Check whether the creation of an object of the type will involve
888 -- use of the secondary stack. If T is a record type, this is true
889 -- if the expression for some component uses the secondary stack, e.g.
890 -- through a call to a function that returns an unconstrained value.
891 -- False if T is controlled, because cleanups occur elsewhere.
897 function Uses_SS (T : Entity_Id) return Boolean is
900 Full_Type : Entity_Id := Underlying_Type (T);
903 -- Normally we want to use the underlying type, but if it's not set
904 -- then continue with T.
906 if not Present (Full_Type) then
910 if Is_Controlled (Full_Type) then
913 elsif Is_Array_Type (Full_Type) then
914 return Uses_SS (Component_Type (Full_Type));
916 elsif Is_Record_Type (Full_Type) then
917 Comp := First_Component (Full_Type);
918 while Present (Comp) loop
919 if Ekind (Comp) = E_Component
920 and then Nkind (Parent (Comp)) = N_Component_Declaration
922 -- The expression for a dynamic component may be rewritten
923 -- as a dereference, so retrieve original node.
925 Expr := Original_Node (Expression (Parent (Comp)));
927 -- Return True if the expression is a call to a function
928 -- (including an attribute function such as Image, or a
929 -- user-defined operator) with a result that requires a
932 if (Nkind (Expr) = N_Function_Call
933 or else Nkind (Expr) in N_Op
934 or else (Nkind (Expr) = N_Attribute_Reference
935 and then Present (Expressions (Expr))))
936 and then Requires_Transient_Scope (Etype (Expr))
940 elsif Uses_SS (Etype (Comp)) then
945 Next_Component (Comp);
955 -- Start of processing for Check_Initialization_Call
958 -- Establish a transient scope if the type needs it
960 if Uses_SS (Typ) then
961 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
963 end Check_Initialization_Call;
965 ---------------------------------------
966 -- Check_No_Direct_Boolean_Operators --
967 ---------------------------------------
969 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
971 if Scope (Entity (N)) = Standard_Standard
972 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
974 -- Restriction only applies to original source code
976 if Comes_From_Source (N) then
977 Check_Restriction (No_Direct_Boolean_Operators, N);
982 Check_Boolean_Operator (N);
984 end Check_No_Direct_Boolean_Operators;
986 ------------------------------
987 -- Check_Parameterless_Call --
988 ------------------------------
990 procedure Check_Parameterless_Call (N : Node_Id) is
993 function Prefix_Is_Access_Subp return Boolean;
994 -- If the prefix is of an access_to_subprogram type, the node must be
995 -- rewritten as a call. Ditto if the prefix is overloaded and all its
996 -- interpretations are access to subprograms.
998 ---------------------------
999 -- Prefix_Is_Access_Subp --
1000 ---------------------------
1002 function Prefix_Is_Access_Subp return Boolean is
1007 -- If the context is an attribute reference that can apply to
1008 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1010 if Nkind (Parent (N)) = N_Attribute_Reference
1011 and then (Attribute_Name (Parent (N)) = Name_Address or else
1012 Attribute_Name (Parent (N)) = Name_Code_Address or else
1013 Attribute_Name (Parent (N)) = Name_Access)
1018 if not Is_Overloaded (N) then
1020 Ekind (Etype (N)) = E_Subprogram_Type
1021 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1023 Get_First_Interp (N, I, It);
1024 while Present (It.Typ) loop
1025 if Ekind (It.Typ) /= E_Subprogram_Type
1026 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1031 Get_Next_Interp (I, It);
1036 end Prefix_Is_Access_Subp;
1038 -- Start of processing for Check_Parameterless_Call
1041 -- Defend against junk stuff if errors already detected
1043 if Total_Errors_Detected /= 0 then
1044 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1046 elsif Nkind (N) in N_Has_Chars
1047 and then Chars (N) in Error_Name_Or_No_Name
1055 -- If the context expects a value, and the name is a procedure, this is
1056 -- most likely a missing 'Access. Don't try to resolve the parameterless
1057 -- call, error will be caught when the outer call is analyzed.
1059 if Is_Entity_Name (N)
1060 and then Ekind (Entity (N)) = E_Procedure
1061 and then not Is_Overloaded (N)
1063 Nkind_In (Parent (N), N_Parameter_Association,
1065 N_Procedure_Call_Statement)
1070 -- Rewrite as call if overloadable entity that is (or could be, in the
1071 -- overloaded case) a function call. If we know for sure that the entity
1072 -- is an enumeration literal, we do not rewrite it.
1074 -- If the entity is the name of an operator, it cannot be a call because
1075 -- operators cannot have default parameters. In this case, this must be
1076 -- a string whose contents coincide with an operator name. Set the kind
1077 -- of the node appropriately.
1079 if (Is_Entity_Name (N)
1080 and then Nkind (N) /= N_Operator_Symbol
1081 and then Is_Overloadable (Entity (N))
1082 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1083 or else Is_Overloaded (N)))
1085 -- Rewrite as call if it is an explicit dereference of an expression of
1086 -- a subprogram access type, and the subprogram type is not that of a
1087 -- procedure or entry.
1090 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1092 -- Rewrite as call if it is a selected component which is a function,
1093 -- this is the case of a call to a protected function (which may be
1094 -- overloaded with other protected operations).
1097 (Nkind (N) = N_Selected_Component
1098 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1100 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1102 and then Is_Overloaded (Selector_Name (N)))))
1104 -- If one of the above three conditions is met, rewrite as call. Apply
1105 -- the rewriting only once.
1108 if Nkind (Parent (N)) /= N_Function_Call
1109 or else N /= Name (Parent (N))
1112 -- This may be a prefixed call that was not fully analyzed, e.g.
1113 -- an actual in an instance.
1115 if Ada_Version >= Ada_2005
1116 and then Nkind (N) = N_Selected_Component
1117 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1119 Analyze_Selected_Component (N);
1121 if Nkind (N) /= N_Selected_Component then
1126 Nam := New_Copy (N);
1128 -- If overloaded, overload set belongs to new copy
1130 Save_Interps (N, Nam);
1132 -- Change node to parameterless function call (note that the
1133 -- Parameter_Associations associations field is left set to Empty,
1134 -- its normal default value since there are no parameters)
1136 Change_Node (N, N_Function_Call);
1138 Set_Sloc (N, Sloc (Nam));
1142 elsif Nkind (N) = N_Parameter_Association then
1143 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1145 elsif Nkind (N) = N_Operator_Symbol then
1146 Change_Operator_Symbol_To_String_Literal (N);
1147 Set_Is_Overloaded (N, False);
1148 Set_Etype (N, Any_String);
1150 end Check_Parameterless_Call;
1152 -----------------------------
1153 -- Is_Definite_Access_Type --
1154 -----------------------------
1156 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1157 Btyp : constant Entity_Id := Base_Type (E);
1159 return Ekind (Btyp) = E_Access_Type
1160 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1161 and then Comes_From_Source (Btyp));
1162 end Is_Definite_Access_Type;
1164 ----------------------
1165 -- Is_Predefined_Op --
1166 ----------------------
1168 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1170 -- Predefined operators are intrinsic subprograms
1172 if not Is_Intrinsic_Subprogram (Nam) then
1176 -- A call to a back-end builtin is never a predefined operator
1178 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1182 return not Is_Generic_Instance (Nam)
1183 and then Chars (Nam) in Any_Operator_Name
1184 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1185 end Is_Predefined_Op;
1187 -----------------------------
1188 -- Make_Call_Into_Operator --
1189 -----------------------------
1191 procedure Make_Call_Into_Operator
1196 Op_Name : constant Name_Id := Chars (Op_Id);
1197 Act1 : Node_Id := First_Actual (N);
1198 Act2 : Node_Id := Next_Actual (Act1);
1199 Error : Boolean := False;
1200 Func : constant Entity_Id := Entity (Name (N));
1201 Is_Binary : constant Boolean := Present (Act2);
1203 Opnd_Type : Entity_Id;
1204 Orig_Type : Entity_Id := Empty;
1207 type Kind_Test is access function (E : Entity_Id) return Boolean;
1209 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1210 -- If the operand is not universal, and the operator is given by an
1211 -- expanded name, verify that the operand has an interpretation with a
1212 -- type defined in the given scope of the operator.
1214 function Type_In_P (Test : Kind_Test) return Entity_Id;
1215 -- Find a type of the given class in package Pack that contains the
1218 ---------------------------
1219 -- Operand_Type_In_Scope --
1220 ---------------------------
1222 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1223 Nod : constant Node_Id := Right_Opnd (Op_Node);
1228 if not Is_Overloaded (Nod) then
1229 return Scope (Base_Type (Etype (Nod))) = S;
1232 Get_First_Interp (Nod, I, It);
1233 while Present (It.Typ) loop
1234 if Scope (Base_Type (It.Typ)) = S then
1238 Get_Next_Interp (I, It);
1243 end Operand_Type_In_Scope;
1249 function Type_In_P (Test : Kind_Test) return Entity_Id is
1252 function In_Decl return Boolean;
1253 -- Verify that node is not part of the type declaration for the
1254 -- candidate type, which would otherwise be invisible.
1260 function In_Decl return Boolean is
1261 Decl_Node : constant Node_Id := Parent (E);
1267 if Etype (E) = Any_Type then
1270 elsif No (Decl_Node) then
1275 and then Nkind (N2) /= N_Compilation_Unit
1277 if N2 = Decl_Node then
1288 -- Start of processing for Type_In_P
1291 -- If the context type is declared in the prefix package, this is the
1292 -- desired base type.
1294 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1295 return Base_Type (Typ);
1298 E := First_Entity (Pack);
1299 while Present (E) loop
1301 and then not In_Decl
1313 -- Start of processing for Make_Call_Into_Operator
1316 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1321 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1322 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1323 Save_Interps (Act1, Left_Opnd (Op_Node));
1324 Save_Interps (Act2, Right_Opnd (Op_Node));
1325 Act1 := Left_Opnd (Op_Node);
1326 Act2 := Right_Opnd (Op_Node);
1331 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1332 Save_Interps (Act1, Right_Opnd (Op_Node));
1333 Act1 := Right_Opnd (Op_Node);
1336 -- If the operator is denoted by an expanded name, and the prefix is
1337 -- not Standard, but the operator is a predefined one whose scope is
1338 -- Standard, then this is an implicit_operator, inserted as an
1339 -- interpretation by the procedure of the same name. This procedure
1340 -- overestimates the presence of implicit operators, because it does
1341 -- not examine the type of the operands. Verify now that the operand
1342 -- type appears in the given scope. If right operand is universal,
1343 -- check the other operand. In the case of concatenation, either
1344 -- argument can be the component type, so check the type of the result.
1345 -- If both arguments are literals, look for a type of the right kind
1346 -- defined in the given scope. This elaborate nonsense is brought to
1347 -- you courtesy of b33302a. The type itself must be frozen, so we must
1348 -- find the type of the proper class in the given scope.
1350 -- A final wrinkle is the multiplication operator for fixed point types,
1351 -- which is defined in Standard only, and not in the scope of the
1352 -- fixed point type itself.
1354 if Nkind (Name (N)) = N_Expanded_Name then
1355 Pack := Entity (Prefix (Name (N)));
1357 -- If the entity being called is defined in the given package, it is
1358 -- a renaming of a predefined operator, and known to be legal.
1360 if Scope (Entity (Name (N))) = Pack
1361 and then Pack /= Standard_Standard
1365 -- Visibility does not need to be checked in an instance: if the
1366 -- operator was not visible in the generic it has been diagnosed
1367 -- already, else there is an implicit copy of it in the instance.
1369 elsif In_Instance then
1372 elsif (Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide)
1373 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1374 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1376 if Pack /= Standard_Standard then
1380 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1383 elsif Ada_Version >= Ada_2005
1384 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1385 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1390 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1392 if Op_Name = Name_Op_Concat then
1393 Opnd_Type := Base_Type (Typ);
1395 elsif (Scope (Opnd_Type) = Standard_Standard
1397 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1399 and then not Comes_From_Source (Opnd_Type))
1401 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1404 if Scope (Opnd_Type) = Standard_Standard then
1406 -- Verify that the scope contains a type that corresponds to
1407 -- the given literal. Optimize the case where Pack is Standard.
1409 if Pack /= Standard_Standard then
1411 if Opnd_Type = Universal_Integer then
1412 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1414 elsif Opnd_Type = Universal_Real then
1415 Orig_Type := Type_In_P (Is_Real_Type'Access);
1417 elsif Opnd_Type = Any_String then
1418 Orig_Type := Type_In_P (Is_String_Type'Access);
1420 elsif Opnd_Type = Any_Access then
1421 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1423 elsif Opnd_Type = Any_Composite then
1424 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1426 if Present (Orig_Type) then
1427 if Has_Private_Component (Orig_Type) then
1430 Set_Etype (Act1, Orig_Type);
1433 Set_Etype (Act2, Orig_Type);
1442 Error := No (Orig_Type);
1445 elsif Ekind (Opnd_Type) = E_Allocator_Type
1446 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1450 -- If the type is defined elsewhere, and the operator is not
1451 -- defined in the given scope (by a renaming declaration, e.g.)
1452 -- then this is an error as well. If an extension of System is
1453 -- present, and the type may be defined there, Pack must be
1456 elsif Scope (Opnd_Type) /= Pack
1457 and then Scope (Op_Id) /= Pack
1458 and then (No (System_Aux_Id)
1459 or else Scope (Opnd_Type) /= System_Aux_Id
1460 or else Pack /= Scope (System_Aux_Id))
1462 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1465 Error := not Operand_Type_In_Scope (Pack);
1468 elsif Pack = Standard_Standard
1469 and then not Operand_Type_In_Scope (Standard_Standard)
1476 Error_Msg_Node_2 := Pack;
1478 ("& not declared in&", N, Selector_Name (Name (N)));
1479 Set_Etype (N, Any_Type);
1482 -- Detect a mismatch between the context type and the result type
1483 -- in the named package, which is otherwise not detected if the
1484 -- operands are universal. Check is only needed if source entity is
1485 -- an operator, not a function that renames an operator.
1487 elsif Nkind (Parent (N)) /= N_Type_Conversion
1488 and then Ekind (Entity (Name (N))) = E_Operator
1489 and then Is_Numeric_Type (Typ)
1490 and then not Is_Universal_Numeric_Type (Typ)
1491 and then Scope (Base_Type (Typ)) /= Pack
1492 and then not In_Instance
1494 if Is_Fixed_Point_Type (Typ)
1495 and then (Op_Name = Name_Op_Multiply
1497 Op_Name = Name_Op_Divide)
1499 -- Already checked above
1503 -- Operator may be defined in an extension of System
1505 elsif Present (System_Aux_Id)
1506 and then Scope (Opnd_Type) = System_Aux_Id
1511 -- Could we use Wrong_Type here??? (this would require setting
1512 -- Etype (N) to the actual type found where Typ was expected).
1514 Error_Msg_NE ("expect }", N, Typ);
1519 Set_Chars (Op_Node, Op_Name);
1521 if not Is_Private_Type (Etype (N)) then
1522 Set_Etype (Op_Node, Base_Type (Etype (N)));
1524 Set_Etype (Op_Node, Etype (N));
1527 -- If this is a call to a function that renames a predefined equality,
1528 -- the renaming declaration provides a type that must be used to
1529 -- resolve the operands. This must be done now because resolution of
1530 -- the equality node will not resolve any remaining ambiguity, and it
1531 -- assumes that the first operand is not overloaded.
1533 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1534 and then Ekind (Func) = E_Function
1535 and then Is_Overloaded (Act1)
1537 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1538 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1541 Set_Entity (Op_Node, Op_Id);
1542 Generate_Reference (Op_Id, N, ' ');
1544 -- Do rewrite setting Comes_From_Source on the result if the original
1545 -- call came from source. Although it is not strictly the case that the
1546 -- operator as such comes from the source, logically it corresponds
1547 -- exactly to the function call in the source, so it should be marked
1548 -- this way (e.g. to make sure that validity checks work fine).
1551 CS : constant Boolean := Comes_From_Source (N);
1553 Rewrite (N, Op_Node);
1554 Set_Comes_From_Source (N, CS);
1557 -- If this is an arithmetic operator and the result type is private,
1558 -- the operands and the result must be wrapped in conversion to
1559 -- expose the underlying numeric type and expand the proper checks,
1560 -- e.g. on division.
1562 if Is_Private_Type (Typ) then
1564 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1565 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1566 Resolve_Intrinsic_Operator (N, Typ);
1568 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1569 Resolve_Intrinsic_Unary_Operator (N, Typ);
1577 end Make_Call_Into_Operator;
1583 function Operator_Kind
1585 Is_Binary : Boolean) return Node_Kind
1590 -- Use CASE statement or array???
1593 if Op_Name = Name_Op_And then
1595 elsif Op_Name = Name_Op_Or then
1597 elsif Op_Name = Name_Op_Xor then
1599 elsif Op_Name = Name_Op_Eq then
1601 elsif Op_Name = Name_Op_Ne then
1603 elsif Op_Name = Name_Op_Lt then
1605 elsif Op_Name = Name_Op_Le then
1607 elsif Op_Name = Name_Op_Gt then
1609 elsif Op_Name = Name_Op_Ge then
1611 elsif Op_Name = Name_Op_Add then
1613 elsif Op_Name = Name_Op_Subtract then
1614 Kind := N_Op_Subtract;
1615 elsif Op_Name = Name_Op_Concat then
1616 Kind := N_Op_Concat;
1617 elsif Op_Name = Name_Op_Multiply then
1618 Kind := N_Op_Multiply;
1619 elsif Op_Name = Name_Op_Divide then
1620 Kind := N_Op_Divide;
1621 elsif Op_Name = Name_Op_Mod then
1623 elsif Op_Name = Name_Op_Rem then
1625 elsif Op_Name = Name_Op_Expon then
1628 raise Program_Error;
1634 if Op_Name = Name_Op_Add then
1636 elsif Op_Name = Name_Op_Subtract then
1638 elsif Op_Name = Name_Op_Abs then
1640 elsif Op_Name = Name_Op_Not then
1643 raise Program_Error;
1650 ----------------------------
1651 -- Preanalyze_And_Resolve --
1652 ----------------------------
1654 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1655 Save_Full_Analysis : constant Boolean := Full_Analysis;
1658 Full_Analysis := False;
1659 Expander_Mode_Save_And_Set (False);
1661 -- We suppress all checks for this analysis, since the checks will
1662 -- be applied properly, and in the right location, when the default
1663 -- expression is reanalyzed and reexpanded later on.
1665 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1667 Expander_Mode_Restore;
1668 Full_Analysis := Save_Full_Analysis;
1669 end Preanalyze_And_Resolve;
1671 -- Version without context type
1673 procedure Preanalyze_And_Resolve (N : Node_Id) is
1674 Save_Full_Analysis : constant Boolean := Full_Analysis;
1677 Full_Analysis := False;
1678 Expander_Mode_Save_And_Set (False);
1681 Resolve (N, Etype (N), Suppress => All_Checks);
1683 Expander_Mode_Restore;
1684 Full_Analysis := Save_Full_Analysis;
1685 end Preanalyze_And_Resolve;
1687 ----------------------------------
1688 -- Replace_Actual_Discriminants --
1689 ----------------------------------
1691 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1692 Loc : constant Source_Ptr := Sloc (N);
1693 Tsk : Node_Id := Empty;
1695 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1696 -- Comment needed???
1702 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1706 if Nkind (Nod) = N_Identifier then
1707 Ent := Entity (Nod);
1710 and then Ekind (Ent) = E_Discriminant
1713 Make_Selected_Component (Loc,
1714 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1715 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1717 Set_Etype (Nod, Etype (Ent));
1725 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1727 -- Start of processing for Replace_Actual_Discriminants
1730 if not Full_Expander_Active then
1734 if Nkind (Name (N)) = N_Selected_Component then
1735 Tsk := Prefix (Name (N));
1737 elsif Nkind (Name (N)) = N_Indexed_Component then
1738 Tsk := Prefix (Prefix (Name (N)));
1744 Replace_Discrs (Default);
1746 end Replace_Actual_Discriminants;
1752 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1753 Ambiguous : Boolean := False;
1754 Ctx_Type : Entity_Id := Typ;
1755 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1756 Err_Type : Entity_Id := Empty;
1757 Found : Boolean := False;
1760 I1 : Interp_Index := 0; -- prevent junk warning
1763 Seen : Entity_Id := Empty; -- prevent junk warning
1765 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1766 -- Determine whether a node comes from a predefined library unit or
1769 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1770 -- Try and fix up a literal so that it matches its expected type. New
1771 -- literals are manufactured if necessary to avoid cascaded errors.
1773 procedure Report_Ambiguous_Argument;
1774 -- Additional diagnostics when an ambiguous call has an ambiguous
1775 -- argument (typically a controlling actual).
1777 procedure Resolution_Failed;
1778 -- Called when attempt at resolving current expression fails
1780 ------------------------------------
1781 -- Comes_From_Predefined_Lib_Unit --
1782 -------------------------------------
1784 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1787 Sloc (Nod) = Standard_Location
1788 or else Is_Predefined_File_Name
1789 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1790 end Comes_From_Predefined_Lib_Unit;
1792 --------------------
1793 -- Patch_Up_Value --
1794 --------------------
1796 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1798 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1800 Make_Real_Literal (Sloc (N),
1801 Realval => UR_From_Uint (Intval (N))));
1802 Set_Etype (N, Universal_Real);
1803 Set_Is_Static_Expression (N);
1805 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1807 Make_Integer_Literal (Sloc (N),
1808 Intval => UR_To_Uint (Realval (N))));
1809 Set_Etype (N, Universal_Integer);
1810 Set_Is_Static_Expression (N);
1812 elsif Nkind (N) = N_String_Literal
1813 and then Is_Character_Type (Typ)
1815 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1817 Make_Character_Literal (Sloc (N),
1819 Char_Literal_Value =>
1820 UI_From_Int (Character'Pos ('A'))));
1821 Set_Etype (N, Any_Character);
1822 Set_Is_Static_Expression (N);
1824 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1826 Make_String_Literal (Sloc (N),
1827 Strval => End_String));
1829 elsif Nkind (N) = N_Range then
1830 Patch_Up_Value (Low_Bound (N), Typ);
1831 Patch_Up_Value (High_Bound (N), Typ);
1835 -------------------------------
1836 -- Report_Ambiguous_Argument --
1837 -------------------------------
1839 procedure Report_Ambiguous_Argument is
1840 Arg : constant Node_Id := First (Parameter_Associations (N));
1845 if Nkind (Arg) = N_Function_Call
1846 and then Is_Entity_Name (Name (Arg))
1847 and then Is_Overloaded (Name (Arg))
1849 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1851 -- Could use comments on what is going on here???
1853 Get_First_Interp (Name (Arg), I, It);
1854 while Present (It.Nam) loop
1855 Error_Msg_Sloc := Sloc (It.Nam);
1857 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1858 Error_Msg_N ("interpretation (inherited) #!", Arg);
1860 Error_Msg_N ("interpretation #!", Arg);
1863 Get_Next_Interp (I, It);
1866 end Report_Ambiguous_Argument;
1868 -----------------------
1869 -- Resolution_Failed --
1870 -----------------------
1872 procedure Resolution_Failed is
1874 Patch_Up_Value (N, Typ);
1876 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1877 Set_Is_Overloaded (N, False);
1879 -- The caller will return without calling the expander, so we need
1880 -- to set the analyzed flag. Note that it is fine to set Analyzed
1881 -- to True even if we are in the middle of a shallow analysis,
1882 -- (see the spec of sem for more details) since this is an error
1883 -- situation anyway, and there is no point in repeating the
1884 -- analysis later (indeed it won't work to repeat it later, since
1885 -- we haven't got a clear resolution of which entity is being
1888 Set_Analyzed (N, True);
1890 end Resolution_Failed;
1892 -- Start of processing for Resolve
1899 -- Access attribute on remote subprogram cannot be used for a non-remote
1900 -- access-to-subprogram type.
1902 if Nkind (N) = N_Attribute_Reference
1903 and then (Attribute_Name (N) = Name_Access or else
1904 Attribute_Name (N) = Name_Unrestricted_Access or else
1905 Attribute_Name (N) = Name_Unchecked_Access)
1906 and then Comes_From_Source (N)
1907 and then Is_Entity_Name (Prefix (N))
1908 and then Is_Subprogram (Entity (Prefix (N)))
1909 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1910 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1913 ("prefix must statically denote a non-remote subprogram", N);
1916 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1918 -- If the context is a Remote_Access_To_Subprogram, access attributes
1919 -- must be resolved with the corresponding fat pointer. There is no need
1920 -- to check for the attribute name since the return type of an
1921 -- attribute is never a remote type.
1923 if Nkind (N) = N_Attribute_Reference
1924 and then Comes_From_Source (N)
1925 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
1928 Attr : constant Attribute_Id :=
1929 Get_Attribute_Id (Attribute_Name (N));
1930 Pref : constant Node_Id := Prefix (N);
1933 Is_Remote : Boolean := True;
1936 -- Check that Typ is a remote access-to-subprogram type
1938 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1940 -- Prefix (N) must statically denote a remote subprogram
1941 -- declared in a package specification.
1943 if Attr = Attribute_Access then
1944 Decl := Unit_Declaration_Node (Entity (Pref));
1946 if Nkind (Decl) = N_Subprogram_Body then
1947 Spec := Corresponding_Spec (Decl);
1949 if not No (Spec) then
1950 Decl := Unit_Declaration_Node (Spec);
1954 Spec := Parent (Decl);
1956 if not Is_Entity_Name (Prefix (N))
1957 or else Nkind (Spec) /= N_Package_Specification
1959 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1963 ("prefix must statically denote a remote subprogram ",
1968 -- If we are generating code for a distributed program.
1969 -- perform semantic checks against the corresponding
1972 if (Attr = Attribute_Access or else
1973 Attr = Attribute_Unchecked_Access or else
1974 Attr = Attribute_Unrestricted_Access)
1975 and then Full_Expander_Active
1976 and then Get_PCS_Name /= Name_No_DSA
1978 Check_Subtype_Conformant
1979 (New_Id => Entity (Prefix (N)),
1980 Old_Id => Designated_Type
1981 (Corresponding_Remote_Type (Typ)),
1985 Process_Remote_AST_Attribute (N, Typ);
1992 Debug_A_Entry ("resolving ", N);
1994 if Debug_Flag_V then
1995 Write_Overloads (N);
1998 if Comes_From_Source (N) then
1999 if Is_Fixed_Point_Type (Typ) then
2000 Check_Restriction (No_Fixed_Point, N);
2002 elsif Is_Floating_Point_Type (Typ)
2003 and then Typ /= Universal_Real
2004 and then Typ /= Any_Real
2006 Check_Restriction (No_Floating_Point, N);
2010 -- Return if already analyzed
2012 if Analyzed (N) then
2013 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2014 Analyze_Dimension (N);
2017 -- Return if type = Any_Type (previous error encountered)
2019 elsif Etype (N) = Any_Type then
2020 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2024 Check_Parameterless_Call (N);
2026 -- If not overloaded, then we know the type, and all that needs doing
2027 -- is to check that this type is compatible with the context.
2029 if not Is_Overloaded (N) then
2030 Found := Covers (Typ, Etype (N));
2031 Expr_Type := Etype (N);
2033 -- In the overloaded case, we must select the interpretation that
2034 -- is compatible with the context (i.e. the type passed to Resolve)
2037 -- Loop through possible interpretations
2039 Get_First_Interp (N, I, It);
2040 Interp_Loop : while Present (It.Typ) loop
2042 if Debug_Flag_V then
2043 Write_Str ("Interp: ");
2047 -- We are only interested in interpretations that are compatible
2048 -- with the expected type, any other interpretations are ignored.
2050 if not Covers (Typ, It.Typ) then
2051 if Debug_Flag_V then
2052 Write_Str (" interpretation incompatible with context");
2057 -- Skip the current interpretation if it is disabled by an
2058 -- abstract operator. This action is performed only when the
2059 -- type against which we are resolving is the same as the
2060 -- type of the interpretation.
2062 if Ada_Version >= Ada_2005
2063 and then It.Typ = Typ
2064 and then Typ /= Universal_Integer
2065 and then Typ /= Universal_Real
2066 and then Present (It.Abstract_Op)
2068 if Debug_Flag_V then
2069 Write_Line ("Skip.");
2075 -- First matching interpretation
2081 Expr_Type := It.Typ;
2083 -- Matching interpretation that is not the first, maybe an
2084 -- error, but there are some cases where preference rules are
2085 -- used to choose between the two possibilities. These and
2086 -- some more obscure cases are handled in Disambiguate.
2089 -- If the current statement is part of a predefined library
2090 -- unit, then all interpretations which come from user level
2091 -- packages should not be considered.
2094 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
2099 Error_Msg_Sloc := Sloc (Seen);
2100 It1 := Disambiguate (N, I1, I, Typ);
2102 -- Disambiguation has succeeded. Skip the remaining
2105 if It1 /= No_Interp then
2107 Expr_Type := It1.Typ;
2109 while Present (It.Typ) loop
2110 Get_Next_Interp (I, It);
2114 -- Before we issue an ambiguity complaint, check for
2115 -- the case of a subprogram call where at least one
2116 -- of the arguments is Any_Type, and if so, suppress
2117 -- the message, since it is a cascaded error.
2119 if Nkind_In (N, N_Function_Call,
2120 N_Procedure_Call_Statement)
2127 A := First_Actual (N);
2128 while Present (A) loop
2131 if Nkind (E) = N_Parameter_Association then
2132 E := Explicit_Actual_Parameter (E);
2135 if Etype (E) = Any_Type then
2136 if Debug_Flag_V then
2137 Write_Str ("Any_Type in call");
2148 elsif Nkind (N) in N_Binary_Op
2149 and then (Etype (Left_Opnd (N)) = Any_Type
2150 or else Etype (Right_Opnd (N)) = Any_Type)
2154 elsif Nkind (N) in N_Unary_Op
2155 and then Etype (Right_Opnd (N)) = Any_Type
2160 -- Not that special case, so issue message using the
2161 -- flag Ambiguous to control printing of the header
2162 -- message only at the start of an ambiguous set.
2164 if not Ambiguous then
2165 if Nkind (N) = N_Function_Call
2166 and then Nkind (Name (N)) = N_Explicit_Dereference
2169 ("ambiguous expression "
2170 & "(cannot resolve indirect call)!", N);
2172 Error_Msg_NE -- CODEFIX
2173 ("ambiguous expression (cannot resolve&)!",
2179 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2181 ("\\possible interpretation (inherited)#!", N);
2183 Error_Msg_N -- CODEFIX
2184 ("\\possible interpretation#!", N);
2188 (N, N_Procedure_Call_Statement, N_Function_Call)
2189 and then Present (Parameter_Associations (N))
2191 Report_Ambiguous_Argument;
2195 Error_Msg_Sloc := Sloc (It.Nam);
2197 -- By default, the error message refers to the candidate
2198 -- interpretation. But if it is a predefined operator, it
2199 -- is implicitly declared at the declaration of the type
2200 -- of the operand. Recover the sloc of that declaration
2201 -- for the error message.
2203 if Nkind (N) in N_Op
2204 and then Scope (It.Nam) = Standard_Standard
2205 and then not Is_Overloaded (Right_Opnd (N))
2206 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2209 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2211 if Comes_From_Source (Err_Type)
2212 and then Present (Parent (Err_Type))
2214 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2217 elsif Nkind (N) in N_Binary_Op
2218 and then Scope (It.Nam) = Standard_Standard
2219 and then not Is_Overloaded (Left_Opnd (N))
2220 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2223 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2225 if Comes_From_Source (Err_Type)
2226 and then Present (Parent (Err_Type))
2228 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2231 -- If this is an indirect call, use the subprogram_type
2232 -- in the message, to have a meaningful location. Also
2233 -- indicate if this is an inherited operation, created
2234 -- by a type declaration.
2236 elsif Nkind (N) = N_Function_Call
2237 and then Nkind (Name (N)) = N_Explicit_Dereference
2238 and then Is_Type (It.Nam)
2242 Sloc (Associated_Node_For_Itype (Err_Type));
2247 if Nkind (N) in N_Op
2248 and then Scope (It.Nam) = Standard_Standard
2249 and then Present (Err_Type)
2251 -- Special-case the message for universal_fixed
2252 -- operators, which are not declared with the type
2253 -- of the operand, but appear forever in Standard.
2255 if It.Typ = Universal_Fixed
2256 and then Scope (It.Nam) = Standard_Standard
2259 ("\\possible interpretation as " &
2260 "universal_fixed operation " &
2261 "(RM 4.5.5 (19))", N);
2264 ("\\possible interpretation (predefined)#!", N);
2268 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2271 ("\\possible interpretation (inherited)#!", N);
2273 Error_Msg_N -- CODEFIX
2274 ("\\possible interpretation#!", N);
2280 -- We have a matching interpretation, Expr_Type is the type
2281 -- from this interpretation, and Seen is the entity.
2283 -- For an operator, just set the entity name. The type will be
2284 -- set by the specific operator resolution routine.
2286 if Nkind (N) in N_Op then
2287 Set_Entity (N, Seen);
2288 Generate_Reference (Seen, N);
2290 elsif Nkind (N) = N_Case_Expression then
2291 Set_Etype (N, Expr_Type);
2293 elsif Nkind (N) = N_Character_Literal then
2294 Set_Etype (N, Expr_Type);
2296 elsif Nkind (N) = N_Conditional_Expression then
2297 Set_Etype (N, Expr_Type);
2299 -- AI05-0139-2: Expression is overloaded because type has
2300 -- implicit dereference. If type matches context, no implicit
2301 -- dereference is involved.
2303 elsif Has_Implicit_Dereference (Expr_Type) then
2304 Set_Etype (N, Expr_Type);
2305 Set_Is_Overloaded (N, False);
2308 elsif Is_Overloaded (N)
2309 and then Present (It.Nam)
2310 and then Ekind (It.Nam) = E_Discriminant
2311 and then Has_Implicit_Dereference (It.Nam)
2313 Build_Explicit_Dereference (N, It.Nam);
2315 -- For an explicit dereference, attribute reference, range,
2316 -- short-circuit form (which is not an operator node), or call
2317 -- with a name that is an explicit dereference, there is
2318 -- nothing to be done at this point.
2320 elsif Nkind_In (N, N_Explicit_Dereference,
2321 N_Attribute_Reference,
2323 N_Indexed_Component,
2326 N_Selected_Component,
2328 or else Nkind (Name (N)) = N_Explicit_Dereference
2332 -- For procedure or function calls, set the type of the name,
2333 -- and also the entity pointer for the prefix.
2335 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2336 and then Is_Entity_Name (Name (N))
2338 Set_Etype (Name (N), Expr_Type);
2339 Set_Entity (Name (N), Seen);
2340 Generate_Reference (Seen, Name (N));
2342 elsif Nkind (N) = N_Function_Call
2343 and then Nkind (Name (N)) = N_Selected_Component
2345 Set_Etype (Name (N), Expr_Type);
2346 Set_Entity (Selector_Name (Name (N)), Seen);
2347 Generate_Reference (Seen, Selector_Name (Name (N)));
2349 -- For all other cases, just set the type of the Name
2352 Set_Etype (Name (N), Expr_Type);
2359 -- Move to next interpretation
2361 exit Interp_Loop when No (It.Typ);
2363 Get_Next_Interp (I, It);
2364 end loop Interp_Loop;
2367 -- At this stage Found indicates whether or not an acceptable
2368 -- interpretation exists. If not, then we have an error, except that if
2369 -- the context is Any_Type as a result of some other error, then we
2370 -- suppress the error report.
2373 if Typ /= Any_Type then
2375 -- If type we are looking for is Void, then this is the procedure
2376 -- call case, and the error is simply that what we gave is not a
2377 -- procedure name (we think of procedure calls as expressions with
2378 -- types internally, but the user doesn't think of them this way!)
2380 if Typ = Standard_Void_Type then
2382 -- Special case message if function used as a procedure
2384 if Nkind (N) = N_Procedure_Call_Statement
2385 and then Is_Entity_Name (Name (N))
2386 and then Ekind (Entity (Name (N))) = E_Function
2389 ("cannot use function & in a procedure call",
2390 Name (N), Entity (Name (N)));
2392 -- Otherwise give general message (not clear what cases this
2393 -- covers, but no harm in providing for them!)
2396 Error_Msg_N ("expect procedure name in procedure call", N);
2401 -- Otherwise we do have a subexpression with the wrong type
2403 -- Check for the case of an allocator which uses an access type
2404 -- instead of the designated type. This is a common error and we
2405 -- specialize the message, posting an error on the operand of the
2406 -- allocator, complaining that we expected the designated type of
2409 elsif Nkind (N) = N_Allocator
2410 and then Ekind (Typ) in Access_Kind
2411 and then Ekind (Etype (N)) in Access_Kind
2412 and then Designated_Type (Etype (N)) = Typ
2414 Wrong_Type (Expression (N), Designated_Type (Typ));
2417 -- Check for view mismatch on Null in instances, for which the
2418 -- view-swapping mechanism has no identifier.
2420 elsif (In_Instance or else In_Inlined_Body)
2421 and then (Nkind (N) = N_Null)
2422 and then Is_Private_Type (Typ)
2423 and then Is_Access_Type (Full_View (Typ))
2425 Resolve (N, Full_View (Typ));
2429 -- Check for an aggregate. Sometimes we can get bogus aggregates
2430 -- from misuse of parentheses, and we are about to complain about
2431 -- the aggregate without even looking inside it.
2433 -- Instead, if we have an aggregate of type Any_Composite, then
2434 -- analyze and resolve the component fields, and then only issue
2435 -- another message if we get no errors doing this (otherwise
2436 -- assume that the errors in the aggregate caused the problem).
2438 elsif Nkind (N) = N_Aggregate
2439 and then Etype (N) = Any_Composite
2441 -- Disable expansion in any case. If there is a type mismatch
2442 -- it may be fatal to try to expand the aggregate. The flag
2443 -- would otherwise be set to false when the error is posted.
2445 Expander_Active := False;
2448 procedure Check_Aggr (Aggr : Node_Id);
2449 -- Check one aggregate, and set Found to True if we have a
2450 -- definite error in any of its elements
2452 procedure Check_Elmt (Aelmt : Node_Id);
2453 -- Check one element of aggregate and set Found to True if
2454 -- we definitely have an error in the element.
2460 procedure Check_Aggr (Aggr : Node_Id) is
2464 if Present (Expressions (Aggr)) then
2465 Elmt := First (Expressions (Aggr));
2466 while Present (Elmt) loop
2472 if Present (Component_Associations (Aggr)) then
2473 Elmt := First (Component_Associations (Aggr));
2474 while Present (Elmt) loop
2476 -- If this is a default-initialized component, then
2477 -- there is nothing to check. The box will be
2478 -- replaced by the appropriate call during late
2481 if not Box_Present (Elmt) then
2482 Check_Elmt (Expression (Elmt));
2494 procedure Check_Elmt (Aelmt : Node_Id) is
2496 -- If we have a nested aggregate, go inside it (to
2497 -- attempt a naked analyze-resolve of the aggregate can
2498 -- cause undesirable cascaded errors). Do not resolve
2499 -- expression if it needs a type from context, as for
2500 -- integer * fixed expression.
2502 if Nkind (Aelmt) = N_Aggregate then
2508 if not Is_Overloaded (Aelmt)
2509 and then Etype (Aelmt) /= Any_Fixed
2514 if Etype (Aelmt) = Any_Type then
2525 -- If an error message was issued already, Found got reset to
2526 -- True, so if it is still False, issue standard Wrong_Type msg.
2529 if Is_Overloaded (N)
2530 and then Nkind (N) = N_Function_Call
2533 Subp_Name : Node_Id;
2535 if Is_Entity_Name (Name (N)) then
2536 Subp_Name := Name (N);
2538 elsif Nkind (Name (N)) = N_Selected_Component then
2540 -- Protected operation: retrieve operation name
2542 Subp_Name := Selector_Name (Name (N));
2545 raise Program_Error;
2548 Error_Msg_Node_2 := Typ;
2549 Error_Msg_NE ("no visible interpretation of&" &
2550 " matches expected type&", N, Subp_Name);
2553 if All_Errors_Mode then
2555 Index : Interp_Index;
2559 Error_Msg_N ("\\possible interpretations:", N);
2561 Get_First_Interp (Name (N), Index, It);
2562 while Present (It.Nam) loop
2563 Error_Msg_Sloc := Sloc (It.Nam);
2564 Error_Msg_Node_2 := It.Nam;
2566 ("\\ type& for & declared#", N, It.Typ);
2567 Get_Next_Interp (Index, It);
2572 Error_Msg_N ("\use -gnatf for details", N);
2576 Wrong_Type (N, Typ);
2584 -- Test if we have more than one interpretation for the context
2586 elsif Ambiguous then
2590 -- Only one intepretation
2593 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2594 -- the "+" on T is abstract, and the operands are of universal type,
2595 -- the above code will have (incorrectly) resolved the "+" to the
2596 -- universal one in Standard. Therefore check for this case and give
2597 -- an error. We can't do this earlier, because it would cause legal
2598 -- cases to get errors (when some other type has an abstract "+").
2600 if Ada_Version >= Ada_2005 and then
2601 Nkind (N) in N_Op and then
2602 Is_Overloaded (N) and then
2603 Is_Universal_Numeric_Type (Etype (Entity (N)))
2605 Get_First_Interp (N, I, It);
2606 while Present (It.Typ) loop
2607 if Present (It.Abstract_Op) and then
2608 Etype (It.Abstract_Op) = Typ
2611 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2615 Get_Next_Interp (I, It);
2619 -- Here we have an acceptable interpretation for the context
2621 -- Propagate type information and normalize tree for various
2622 -- predefined operations. If the context only imposes a class of
2623 -- types, rather than a specific type, propagate the actual type
2626 if Typ = Any_Integer or else
2627 Typ = Any_Boolean or else
2628 Typ = Any_Modular or else
2629 Typ = Any_Real or else
2632 Ctx_Type := Expr_Type;
2634 -- Any_Fixed is legal in a real context only if a specific fixed-
2635 -- point type is imposed. If Norman Cohen can be confused by this,
2636 -- it deserves a separate message.
2639 and then Expr_Type = Any_Fixed
2641 Error_Msg_N ("illegal context for mixed mode operation", N);
2642 Set_Etype (N, Universal_Real);
2643 Ctx_Type := Universal_Real;
2647 -- A user-defined operator is transformed into a function call at
2648 -- this point, so that further processing knows that operators are
2649 -- really operators (i.e. are predefined operators). User-defined
2650 -- operators that are intrinsic are just renamings of the predefined
2651 -- ones, and need not be turned into calls either, but if they rename
2652 -- a different operator, we must transform the node accordingly.
2653 -- Instantiations of Unchecked_Conversion are intrinsic but are
2654 -- treated as functions, even if given an operator designator.
2656 if Nkind (N) in N_Op
2657 and then Present (Entity (N))
2658 and then Ekind (Entity (N)) /= E_Operator
2661 if not Is_Predefined_Op (Entity (N)) then
2662 Rewrite_Operator_As_Call (N, Entity (N));
2664 elsif Present (Alias (Entity (N)))
2666 Nkind (Parent (Parent (Entity (N)))) =
2667 N_Subprogram_Renaming_Declaration
2669 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2671 -- If the node is rewritten, it will be fully resolved in
2672 -- Rewrite_Renamed_Operator.
2674 if Analyzed (N) then
2680 case N_Subexpr'(Nkind (N)) is
2682 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2684 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2686 when N_Short_Circuit
2687 => Resolve_Short_Circuit (N, Ctx_Type);
2689 when N_Attribute_Reference
2690 => Resolve_Attribute (N, Ctx_Type);
2692 when N_Case_Expression
2693 => Resolve_Case_Expression (N, Ctx_Type);
2695 when N_Character_Literal
2696 => Resolve_Character_Literal (N, Ctx_Type);
2698 when N_Conditional_Expression
2699 => Resolve_Conditional_Expression (N, Ctx_Type);
2701 when N_Expanded_Name
2702 => Resolve_Entity_Name (N, Ctx_Type);
2704 when N_Explicit_Dereference
2705 => Resolve_Explicit_Dereference (N, Ctx_Type);
2707 when N_Expression_With_Actions
2708 => Resolve_Expression_With_Actions (N, Ctx_Type);
2710 when N_Extension_Aggregate
2711 => Resolve_Extension_Aggregate (N, Ctx_Type);
2713 when N_Function_Call
2714 => Resolve_Call (N, Ctx_Type);
2717 => Resolve_Entity_Name (N, Ctx_Type);
2719 when N_Indexed_Component
2720 => Resolve_Indexed_Component (N, Ctx_Type);
2722 when N_Integer_Literal
2723 => Resolve_Integer_Literal (N, Ctx_Type);
2725 when N_Membership_Test
2726 => Resolve_Membership_Op (N, Ctx_Type);
2728 when N_Null => Resolve_Null (N, Ctx_Type);
2730 when N_Op_And | N_Op_Or | N_Op_Xor
2731 => Resolve_Logical_Op (N, Ctx_Type);
2733 when N_Op_Eq | N_Op_Ne
2734 => Resolve_Equality_Op (N, Ctx_Type);
2736 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2737 => Resolve_Comparison_Op (N, Ctx_Type);
2739 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2741 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2742 N_Op_Divide | N_Op_Mod | N_Op_Rem
2744 => Resolve_Arithmetic_Op (N, Ctx_Type);
2746 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2748 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2750 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2751 => Resolve_Unary_Op (N, Ctx_Type);
2753 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2755 when N_Procedure_Call_Statement
2756 => Resolve_Call (N, Ctx_Type);
2758 when N_Operator_Symbol
2759 => Resolve_Operator_Symbol (N, Ctx_Type);
2761 when N_Qualified_Expression
2762 => Resolve_Qualified_Expression (N, Ctx_Type);
2764 when N_Quantified_Expression
2765 => Resolve_Quantified_Expression (N, Ctx_Type);
2767 when N_Raise_xxx_Error
2768 => Set_Etype (N, Ctx_Type);
2770 when N_Range => Resolve_Range (N, Ctx_Type);
2773 => Resolve_Real_Literal (N, Ctx_Type);
2775 when N_Reference => Resolve_Reference (N, Ctx_Type);
2777 when N_Selected_Component
2778 => Resolve_Selected_Component (N, Ctx_Type);
2780 when N_Slice => Resolve_Slice (N, Ctx_Type);
2782 when N_String_Literal
2783 => Resolve_String_Literal (N, Ctx_Type);
2785 when N_Subprogram_Info
2786 => Resolve_Subprogram_Info (N, Ctx_Type);
2788 when N_Type_Conversion
2789 => Resolve_Type_Conversion (N, Ctx_Type);
2791 when N_Unchecked_Expression =>
2792 Resolve_Unchecked_Expression (N, Ctx_Type);
2794 when N_Unchecked_Type_Conversion =>
2795 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2798 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2799 -- expression of an anonymous access type that occurs in the context
2800 -- of a named general access type, except when the expression is that
2801 -- of a membership test. This ensures proper legality checking in
2802 -- terms of allowed conversions (expressions that would be illegal to
2803 -- convert implicitly are allowed in membership tests).
2805 if Ada_Version >= Ada_2012
2806 and then Ekind (Ctx_Type) = E_General_Access_Type
2807 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2808 and then Nkind (Parent (N)) not in N_Membership_Test
2810 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2811 Analyze_And_Resolve (N, Ctx_Type);
2814 -- If the subexpression was replaced by a non-subexpression, then
2815 -- all we do is to expand it. The only legitimate case we know of
2816 -- is converting procedure call statement to entry call statements,
2817 -- but there may be others, so we are making this test general.
2819 if Nkind (N) not in N_Subexpr then
2820 Debug_A_Exit ("resolving ", N, " (done)");
2825 -- AI05-144-2: Check dangerous order dependence within an expression
2826 -- that is not a subexpression. Exclude RHS of an assignment, because
2827 -- both sides may have side-effects and the check must be performed
2828 -- over the statement.
2830 if Nkind (Parent (N)) not in N_Subexpr
2831 and then Nkind (Parent (N)) /= N_Assignment_Statement
2832 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
2834 Check_Order_Dependence;
2837 -- The expression is definitely NOT overloaded at this point, so
2838 -- we reset the Is_Overloaded flag to avoid any confusion when
2839 -- reanalyzing the node.
2841 Set_Is_Overloaded (N, False);
2843 -- Freeze expression type, entity if it is a name, and designated
2844 -- type if it is an allocator (RM 13.14(10,11,13)).
2846 -- Now that the resolution of the type of the node is complete, and
2847 -- we did not detect an error, we can expand this node. We skip the
2848 -- expand call if we are in a default expression, see section
2849 -- "Handling of Default Expressions" in Sem spec.
2851 Debug_A_Exit ("resolving ", N, " (done)");
2853 -- We unconditionally freeze the expression, even if we are in
2854 -- default expression mode (the Freeze_Expression routine tests this
2855 -- flag and only freezes static types if it is set).
2857 -- Ada 2012 (AI05-177): Expression functions do not freeze. Only
2858 -- their use (in an expanded call) freezes.
2860 if Ekind (Current_Scope) /= E_Function
2862 Nkind (Original_Node (Unit_Declaration_Node (Current_Scope))) /=
2863 N_Expression_Function
2865 Freeze_Expression (N);
2868 -- Now we can do the expansion
2878 -- Version with check(s) suppressed
2880 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2882 if Suppress = All_Checks then
2884 Svg : constant Suppress_Array := Scope_Suppress;
2886 Scope_Suppress := (others => True);
2888 Scope_Suppress := Svg;
2893 Svg : constant Boolean := Scope_Suppress (Suppress);
2895 Scope_Suppress (Suppress) := True;
2897 Scope_Suppress (Suppress) := Svg;
2906 -- Version with implicit type
2908 procedure Resolve (N : Node_Id) is
2910 Resolve (N, Etype (N));
2913 ---------------------
2914 -- Resolve_Actuals --
2915 ---------------------
2917 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2918 Loc : constant Source_Ptr := Sloc (N);
2923 Prev : Node_Id := Empty;
2926 procedure Check_Argument_Order;
2927 -- Performs a check for the case where the actuals are all simple
2928 -- identifiers that correspond to the formal names, but in the wrong
2929 -- order, which is considered suspicious and cause for a warning.
2931 procedure Check_Prefixed_Call;
2932 -- If the original node is an overloaded call in prefix notation,
2933 -- insert an 'Access or a dereference as needed over the first actual.
2934 -- Try_Object_Operation has already verified that there is a valid
2935 -- interpretation, but the form of the actual can only be determined
2936 -- once the primitive operation is identified.
2938 procedure Insert_Default;
2939 -- If the actual is missing in a call, insert in the actuals list
2940 -- an instance of the default expression. The insertion is always
2941 -- a named association.
2943 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2944 -- Check whether T1 and T2, or their full views, are derived from a
2945 -- common type. Used to enforce the restrictions on array conversions
2948 function Static_Concatenation (N : Node_Id) return Boolean;
2949 -- Predicate to determine whether an actual that is a concatenation
2950 -- will be evaluated statically and does not need a transient scope.
2951 -- This must be determined before the actual is resolved and expanded
2952 -- because if needed the transient scope must be introduced earlier.
2954 --------------------------
2955 -- Check_Argument_Order --
2956 --------------------------
2958 procedure Check_Argument_Order is
2960 -- Nothing to do if no parameters, or original node is neither a
2961 -- function call nor a procedure call statement (happens in the
2962 -- operator-transformed-to-function call case), or the call does
2963 -- not come from source, or this warning is off.
2965 if not Warn_On_Parameter_Order
2966 or else No (Parameter_Associations (N))
2967 or else not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2969 or else not Comes_From_Source (N)
2975 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2978 -- Nothing to do if only one parameter
2984 -- Here if at least two arguments
2987 Actuals : array (1 .. Nargs) of Node_Id;
2991 Wrong_Order : Boolean := False;
2992 -- Set True if an out of order case is found
2995 -- Collect identifier names of actuals, fail if any actual is
2996 -- not a simple identifier, and record max length of name.
2998 Actual := First (Parameter_Associations (N));
2999 for J in Actuals'Range loop
3000 if Nkind (Actual) /= N_Identifier then
3003 Actuals (J) := Actual;
3008 -- If we got this far, all actuals are identifiers and the list
3009 -- of their names is stored in the Actuals array.
3011 Formal := First_Formal (Nam);
3012 for J in Actuals'Range loop
3014 -- If we ran out of formals, that's odd, probably an error
3015 -- which will be detected elsewhere, but abandon the search.
3021 -- If name matches and is in order OK
3023 if Chars (Formal) = Chars (Actuals (J)) then
3027 -- If no match, see if it is elsewhere in list and if so
3028 -- flag potential wrong order if type is compatible.
3030 for K in Actuals'Range loop
3031 if Chars (Formal) = Chars (Actuals (K))
3033 Has_Compatible_Type (Actuals (K), Etype (Formal))
3035 Wrong_Order := True;
3045 <<Continue>> Next_Formal (Formal);
3048 -- If Formals left over, also probably an error, skip warning
3050 if Present (Formal) then
3054 -- Here we give the warning if something was out of order
3058 ("actuals for this call may be in wrong order?", N);
3062 end Check_Argument_Order;
3064 -------------------------
3065 -- Check_Prefixed_Call --
3066 -------------------------
3068 procedure Check_Prefixed_Call is
3069 Act : constant Node_Id := First_Actual (N);
3070 A_Type : constant Entity_Id := Etype (Act);
3071 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3072 Orig : constant Node_Id := Original_Node (N);
3076 -- Check whether the call is a prefixed call, with or without
3077 -- additional actuals.
3079 if Nkind (Orig) = N_Selected_Component
3081 (Nkind (Orig) = N_Indexed_Component
3082 and then Nkind (Prefix (Orig)) = N_Selected_Component
3083 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3084 and then Is_Entity_Name (Act)
3085 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3087 if Is_Access_Type (A_Type)
3088 and then not Is_Access_Type (F_Type)
3090 -- Introduce dereference on object in prefix
3093 Make_Explicit_Dereference (Sloc (Act),
3094 Prefix => Relocate_Node (Act));
3095 Rewrite (Act, New_A);
3098 elsif Is_Access_Type (F_Type)
3099 and then not Is_Access_Type (A_Type)
3101 -- Introduce an implicit 'Access in prefix
3103 if not Is_Aliased_View (Act) then
3105 ("object in prefixed call to& must be aliased"
3106 & " (RM-2005 4.3.1 (13))",
3111 Make_Attribute_Reference (Loc,
3112 Attribute_Name => Name_Access,
3113 Prefix => Relocate_Node (Act)));
3118 end Check_Prefixed_Call;
3120 --------------------
3121 -- Insert_Default --
3122 --------------------
3124 procedure Insert_Default is
3129 -- Missing argument in call, nothing to insert
3131 if No (Default_Value (F)) then
3135 -- Note that we do a full New_Copy_Tree, so that any associated
3136 -- Itypes are properly copied. This may not be needed any more,
3137 -- but it does no harm as a safety measure! Defaults of a generic
3138 -- formal may be out of bounds of the corresponding actual (see
3139 -- cc1311b) and an additional check may be required.
3144 New_Scope => Current_Scope,
3147 if Is_Concurrent_Type (Scope (Nam))
3148 and then Has_Discriminants (Scope (Nam))
3150 Replace_Actual_Discriminants (N, Actval);
3153 if Is_Overloadable (Nam)
3154 and then Present (Alias (Nam))
3156 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3157 and then not Is_Tagged_Type (Etype (F))
3159 -- If default is a real literal, do not introduce a
3160 -- conversion whose effect may depend on the run-time
3161 -- size of universal real.
3163 if Nkind (Actval) = N_Real_Literal then
3164 Set_Etype (Actval, Base_Type (Etype (F)));
3166 Actval := Unchecked_Convert_To (Etype (F), Actval);
3170 if Is_Scalar_Type (Etype (F)) then
3171 Enable_Range_Check (Actval);
3174 Set_Parent (Actval, N);
3176 -- Resolve aggregates with their base type, to avoid scope
3177 -- anomalies: the subtype was first built in the subprogram
3178 -- declaration, and the current call may be nested.
3180 if Nkind (Actval) = N_Aggregate then
3181 Analyze_And_Resolve (Actval, Etype (F));
3183 Analyze_And_Resolve (Actval, Etype (Actval));
3187 Set_Parent (Actval, N);
3189 -- See note above concerning aggregates
3191 if Nkind (Actval) = N_Aggregate
3192 and then Has_Discriminants (Etype (Actval))
3194 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3196 -- Resolve entities with their own type, which may differ from
3197 -- the type of a reference in a generic context (the view
3198 -- swapping mechanism did not anticipate the re-analysis of
3199 -- default values in calls).
3201 elsif Is_Entity_Name (Actval) then
3202 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3205 Analyze_And_Resolve (Actval, Etype (Actval));
3209 -- If default is a tag indeterminate function call, propagate tag
3210 -- to obtain proper dispatching.
3212 if Is_Controlling_Formal (F)
3213 and then Nkind (Default_Value (F)) = N_Function_Call
3215 Set_Is_Controlling_Actual (Actval);
3220 -- If the default expression raises constraint error, then just
3221 -- silently replace it with an N_Raise_Constraint_Error node, since
3222 -- we already gave the warning on the subprogram spec. If node is
3223 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3224 -- the warnings removal machinery.
3226 if Raises_Constraint_Error (Actval)
3227 and then Nkind (Actval) /= N_Raise_Constraint_Error
3230 Make_Raise_Constraint_Error (Loc,
3231 Reason => CE_Range_Check_Failed));
3232 Set_Raises_Constraint_Error (Actval);
3233 Set_Etype (Actval, Etype (F));
3237 Make_Parameter_Association (Loc,
3238 Explicit_Actual_Parameter => Actval,
3239 Selector_Name => Make_Identifier (Loc, Chars (F)));
3241 -- Case of insertion is first named actual
3243 if No (Prev) or else
3244 Nkind (Parent (Prev)) /= N_Parameter_Association
3246 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3247 Set_First_Named_Actual (N, Actval);
3250 if No (Parameter_Associations (N)) then
3251 Set_Parameter_Associations (N, New_List (Assoc));
3253 Append (Assoc, Parameter_Associations (N));
3257 Insert_After (Prev, Assoc);
3260 -- Case of insertion is not first named actual
3263 Set_Next_Named_Actual
3264 (Assoc, Next_Named_Actual (Parent (Prev)));
3265 Set_Next_Named_Actual (Parent (Prev), Actval);
3266 Append (Assoc, Parameter_Associations (N));
3269 Mark_Rewrite_Insertion (Assoc);
3270 Mark_Rewrite_Insertion (Actval);
3279 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3280 FT1 : Entity_Id := T1;
3281 FT2 : Entity_Id := T2;
3284 if Is_Private_Type (T1)
3285 and then Present (Full_View (T1))
3287 FT1 := Full_View (T1);
3290 if Is_Private_Type (T2)
3291 and then Present (Full_View (T2))
3293 FT2 := Full_View (T2);
3296 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3299 --------------------------
3300 -- Static_Concatenation --
3301 --------------------------
3303 function Static_Concatenation (N : Node_Id) return Boolean is
3306 when N_String_Literal =>
3311 -- Concatenation is static when both operands are static and
3312 -- the concatenation operator is a predefined one.
3314 return Scope (Entity (N)) = Standard_Standard
3316 Static_Concatenation (Left_Opnd (N))
3318 Static_Concatenation (Right_Opnd (N));
3321 if Is_Entity_Name (N) then
3323 Ent : constant Entity_Id := Entity (N);
3325 return Ekind (Ent) = E_Constant
3326 and then Present (Constant_Value (Ent))
3328 Is_Static_Expression (Constant_Value (Ent));
3335 end Static_Concatenation;
3337 -- Start of processing for Resolve_Actuals
3340 Check_Argument_Order;
3342 if Present (First_Actual (N)) then
3343 Check_Prefixed_Call;
3346 A := First_Actual (N);
3347 F := First_Formal (Nam);
3348 while Present (F) loop
3349 if No (A) and then Needs_No_Actuals (Nam) then
3352 -- If we have an error in any actual or formal, indicated by a type
3353 -- of Any_Type, then abandon resolution attempt, and set result type
3356 elsif (Present (A) and then Etype (A) = Any_Type)
3357 or else Etype (F) = Any_Type
3359 Set_Etype (N, Any_Type);
3363 -- Case where actual is present
3365 -- If the actual is an entity, generate a reference to it now. We
3366 -- do this before the actual is resolved, because a formal of some
3367 -- protected subprogram, or a task discriminant, will be rewritten
3368 -- during expansion, and the source entity reference may be lost.
3371 and then Is_Entity_Name (A)
3372 and then Comes_From_Source (N)
3374 Orig_A := Entity (A);
3376 if Present (Orig_A) then
3377 if Is_Formal (Orig_A)
3378 and then Ekind (F) /= E_In_Parameter
3380 Generate_Reference (Orig_A, A, 'm');
3382 elsif not Is_Overloaded (A) then
3383 Generate_Reference (Orig_A, A);
3389 and then (Nkind (Parent (A)) /= N_Parameter_Association
3390 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3392 -- If style checking mode on, check match of formal name
3395 if Nkind (Parent (A)) = N_Parameter_Association then
3396 Check_Identifier (Selector_Name (Parent (A)), F);
3400 -- If the formal is Out or In_Out, do not resolve and expand the
3401 -- conversion, because it is subsequently expanded into explicit
3402 -- temporaries and assignments. However, the object of the
3403 -- conversion can be resolved. An exception is the case of tagged
3404 -- type conversion with a class-wide actual. In that case we want
3405 -- the tag check to occur and no temporary will be needed (no
3406 -- representation change can occur) and the parameter is passed by
3407 -- reference, so we go ahead and resolve the type conversion.
3408 -- Another exception is the case of reference to component or
3409 -- subcomponent of a bit-packed array, in which case we want to
3410 -- defer expansion to the point the in and out assignments are
3413 if Ekind (F) /= E_In_Parameter
3414 and then Nkind (A) = N_Type_Conversion
3415 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3417 if Ekind (F) = E_In_Out_Parameter
3418 and then Is_Array_Type (Etype (F))
3420 -- In a view conversion, the conversion must be legal in
3421 -- both directions, and thus both component types must be
3422 -- aliased, or neither (4.6 (8)).
3424 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3425 -- the privacy requirement should not apply to generic
3426 -- types, and should be checked in an instance. ARG query
3429 if Has_Aliased_Components (Etype (Expression (A))) /=
3430 Has_Aliased_Components (Etype (F))
3433 ("both component types in a view conversion must be"
3434 & " aliased, or neither", A);
3436 -- Comment here??? what set of cases???
3439 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3441 -- Check view conv between unrelated by ref array types
3443 if Is_By_Reference_Type (Etype (F))
3444 or else Is_By_Reference_Type (Etype (Expression (A)))
3447 ("view conversion between unrelated by reference " &
3448 "array types not allowed (\'A'I-00246)", A);
3450 -- In Ada 2005 mode, check view conversion component
3451 -- type cannot be private, tagged, or volatile. Note
3452 -- that we only apply this to source conversions. The
3453 -- generated code can contain conversions which are
3454 -- not subject to this test, and we cannot extract the
3455 -- component type in such cases since it is not present.
3457 elsif Comes_From_Source (A)
3458 and then Ada_Version >= Ada_2005
3461 Comp_Type : constant Entity_Id :=
3463 (Etype (Expression (A)));
3465 if (Is_Private_Type (Comp_Type)
3466 and then not Is_Generic_Type (Comp_Type))
3467 or else Is_Tagged_Type (Comp_Type)
3468 or else Is_Volatile (Comp_Type)
3471 ("component type of a view conversion cannot"
3472 & " be private, tagged, or volatile"
3481 -- Resolve expression if conversion is all OK
3483 if (Conversion_OK (A)
3484 or else Valid_Conversion (A, Etype (A), Expression (A)))
3485 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3487 Resolve (Expression (A));
3490 -- If the actual is a function call that returns a limited
3491 -- unconstrained object that needs finalization, create a
3492 -- transient scope for it, so that it can receive the proper
3493 -- finalization list.
3495 elsif Nkind (A) = N_Function_Call
3496 and then Is_Limited_Record (Etype (F))
3497 and then not Is_Constrained (Etype (F))
3498 and then Full_Expander_Active
3499 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3501 Establish_Transient_Scope (A, False);
3502 Resolve (A, Etype (F));
3504 -- A small optimization: if one of the actuals is a concatenation
3505 -- create a block around a procedure call to recover stack space.
3506 -- This alleviates stack usage when several procedure calls in
3507 -- the same statement list use concatenation. We do not perform
3508 -- this wrapping for code statements, where the argument is a
3509 -- static string, and we want to preserve warnings involving
3510 -- sequences of such statements.
3512 elsif Nkind (A) = N_Op_Concat
3513 and then Nkind (N) = N_Procedure_Call_Statement
3514 and then Full_Expander_Active
3516 not (Is_Intrinsic_Subprogram (Nam)
3517 and then Chars (Nam) = Name_Asm)
3518 and then not Static_Concatenation (A)
3520 Establish_Transient_Scope (A, False);
3521 Resolve (A, Etype (F));
3524 if Nkind (A) = N_Type_Conversion
3525 and then Is_Array_Type (Etype (F))
3526 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3528 (Is_Limited_Type (Etype (F))
3529 or else Is_Limited_Type (Etype (Expression (A))))
3532 ("conversion between unrelated limited array types " &
3533 "not allowed (\A\I-00246)", A);
3535 if Is_Limited_Type (Etype (F)) then
3536 Explain_Limited_Type (Etype (F), A);
3539 if Is_Limited_Type (Etype (Expression (A))) then
3540 Explain_Limited_Type (Etype (Expression (A)), A);
3544 -- (Ada 2005: AI-251): If the actual is an allocator whose
3545 -- directly designated type is a class-wide interface, we build
3546 -- an anonymous access type to use it as the type of the
3547 -- allocator. Later, when the subprogram call is expanded, if
3548 -- the interface has a secondary dispatch table the expander
3549 -- will add a type conversion to force the correct displacement
3552 if Nkind (A) = N_Allocator then
3554 DDT : constant Entity_Id :=
3555 Directly_Designated_Type (Base_Type (Etype (F)));
3557 New_Itype : Entity_Id;
3560 if Is_Class_Wide_Type (DDT)
3561 and then Is_Interface (DDT)
3563 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3564 Set_Etype (New_Itype, Etype (A));
3565 Set_Directly_Designated_Type (New_Itype,
3566 Directly_Designated_Type (Etype (A)));
3567 Set_Etype (A, New_Itype);
3570 -- Ada 2005, AI-162:If the actual is an allocator, the
3571 -- innermost enclosing statement is the master of the
3572 -- created object. This needs to be done with expansion
3573 -- enabled only, otherwise the transient scope will not
3574 -- be removed in the expansion of the wrapped construct.
3576 if (Is_Controlled (DDT) or else Has_Task (DDT))
3577 and then Full_Expander_Active
3579 Establish_Transient_Scope (A, False);
3584 -- (Ada 2005): The call may be to a primitive operation of
3585 -- a tagged synchronized type, declared outside of the type.
3586 -- In this case the controlling actual must be converted to
3587 -- its corresponding record type, which is the formal type.
3588 -- The actual may be a subtype, either because of a constraint
3589 -- or because it is a generic actual, so use base type to
3590 -- locate concurrent type.
3592 F_Typ := Base_Type (Etype (F));
3594 if Is_Tagged_Type (F_Typ)
3595 and then (Is_Concurrent_Type (F_Typ)
3596 or else Is_Concurrent_Record_Type (F_Typ))
3598 -- If the actual is overloaded, look for an interpretation
3599 -- that has a synchronized type.
3601 if not Is_Overloaded (A) then
3602 A_Typ := Base_Type (Etype (A));
3606 Index : Interp_Index;
3610 Get_First_Interp (A, Index, It);
3611 while Present (It.Typ) loop
3612 if Is_Concurrent_Type (It.Typ)
3613 or else Is_Concurrent_Record_Type (It.Typ)
3615 A_Typ := Base_Type (It.Typ);
3619 Get_Next_Interp (Index, It);
3625 Full_A_Typ : Entity_Id;
3628 if Present (Full_View (A_Typ)) then
3629 Full_A_Typ := Base_Type (Full_View (A_Typ));
3631 Full_A_Typ := A_Typ;
3634 -- Tagged synchronized type (case 1): the actual is a
3637 if Is_Concurrent_Type (A_Typ)
3638 and then Corresponding_Record_Type (A_Typ) = F_Typ
3641 Unchecked_Convert_To
3642 (Corresponding_Record_Type (A_Typ), A));
3643 Resolve (A, Etype (F));
3645 -- Tagged synchronized type (case 2): the formal is a
3648 elsif Ekind (Full_A_Typ) = E_Record_Type
3650 (Corresponding_Concurrent_Type (Full_A_Typ))
3651 and then Is_Concurrent_Type (F_Typ)
3652 and then Present (Corresponding_Record_Type (F_Typ))
3653 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3655 Resolve (A, Corresponding_Record_Type (F_Typ));
3660 Resolve (A, Etype (F));
3665 -- not a synchronized operation.
3667 Resolve (A, Etype (F));
3674 if Comes_From_Source (Original_Node (N))
3675 and then Nkind_In (Original_Node (N), N_Function_Call,
3676 N_Procedure_Call_Statement)
3678 -- In formal mode, check that actual parameters matching
3679 -- formals of tagged types are objects (or ancestor type
3680 -- conversions of objects), not general expressions.
3682 if Is_Actual_Tagged_Parameter (A) then
3683 if Is_SPARK_Object_Reference (A) then
3686 elsif Nkind (A) = N_Type_Conversion then
3688 Operand : constant Node_Id := Expression (A);
3689 Operand_Typ : constant Entity_Id := Etype (Operand);
3690 Target_Typ : constant Entity_Id := A_Typ;
3693 if not Is_SPARK_Object_Reference (Operand) then
3694 Check_SPARK_Restriction
3695 ("object required", Operand);
3697 -- In formal mode, the only view conversions are those
3698 -- involving ancestor conversion of an extended type.
3701 (Is_Tagged_Type (Target_Typ)
3702 and then not Is_Class_Wide_Type (Target_Typ)
3703 and then Is_Tagged_Type (Operand_Typ)
3704 and then not Is_Class_Wide_Type (Operand_Typ)
3705 and then Is_Ancestor (Target_Typ, Operand_Typ))
3708 (F, E_Out_Parameter, E_In_Out_Parameter)
3710 Check_SPARK_Restriction
3711 ("ancestor conversion is the only permitted "
3712 & "view conversion", A);
3714 Check_SPARK_Restriction
3715 ("ancestor conversion required", A);
3724 Check_SPARK_Restriction ("object required", A);
3727 -- In formal mode, the only view conversions are those
3728 -- involving ancestor conversion of an extended type.
3730 elsif Nkind (A) = N_Type_Conversion
3731 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3733 Check_SPARK_Restriction
3734 ("ancestor conversion is the only permitted view "
3739 -- Save actual for subsequent check on order dependence, and
3740 -- indicate whether actual is modifiable. For AI05-0144-2.
3742 -- If this is a call to a reference function that is the result
3743 -- of expansion, as in element iterator loops, this does not lead
3744 -- to a dangerous order dependence: only subsequent use of the
3745 -- denoted element might, in some enclosing call.
3747 if not Has_Implicit_Dereference (Etype (Nam))
3748 or else Comes_From_Source (N)
3750 Save_Actual (A, Ekind (F) /= E_In_Parameter);
3753 -- For mode IN, if actual is an entity, and the type of the formal
3754 -- has warnings suppressed, then we reset Never_Set_In_Source for
3755 -- the calling entity. The reason for this is to catch cases like
3756 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3757 -- uses trickery to modify an IN parameter.
3759 if Ekind (F) = E_In_Parameter
3760 and then Is_Entity_Name (A)
3761 and then Present (Entity (A))
3762 and then Ekind (Entity (A)) = E_Variable
3763 and then Has_Warnings_Off (F_Typ)
3765 Set_Never_Set_In_Source (Entity (A), False);
3768 -- Perform error checks for IN and IN OUT parameters
3770 if Ekind (F) /= E_Out_Parameter then
3772 -- Check unset reference. For scalar parameters, it is clearly
3773 -- wrong to pass an uninitialized value as either an IN or
3774 -- IN-OUT parameter. For composites, it is also clearly an
3775 -- error to pass a completely uninitialized value as an IN
3776 -- parameter, but the case of IN OUT is trickier. We prefer
3777 -- not to give a warning here. For example, suppose there is
3778 -- a routine that sets some component of a record to False.
3779 -- It is perfectly reasonable to make this IN-OUT and allow
3780 -- either initialized or uninitialized records to be passed
3783 -- For partially initialized composite values, we also avoid
3784 -- warnings, since it is quite likely that we are passing a
3785 -- partially initialized value and only the initialized fields
3786 -- will in fact be read in the subprogram.
3788 if Is_Scalar_Type (A_Typ)
3789 or else (Ekind (F) = E_In_Parameter
3790 and then not Is_Partially_Initialized_Type (A_Typ))
3792 Check_Unset_Reference (A);
3795 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3796 -- actual to a nested call, since this is case of reading an
3797 -- out parameter, which is not allowed.
3799 if Ada_Version = Ada_83
3800 and then Is_Entity_Name (A)
3801 and then Ekind (Entity (A)) = E_Out_Parameter
3803 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3807 -- Case of OUT or IN OUT parameter
3809 if Ekind (F) /= E_In_Parameter then
3811 -- For an Out parameter, check for useless assignment. Note
3812 -- that we can't set Last_Assignment this early, because we may
3813 -- kill current values in Resolve_Call, and that call would
3814 -- clobber the Last_Assignment field.
3816 -- Note: call Warn_On_Useless_Assignment before doing the check
3817 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3818 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3819 -- reflects the last assignment, not this one!
3821 if Ekind (F) = E_Out_Parameter then
3822 if Warn_On_Modified_As_Out_Parameter (F)
3823 and then Is_Entity_Name (A)
3824 and then Present (Entity (A))
3825 and then Comes_From_Source (N)
3827 Warn_On_Useless_Assignment (Entity (A), A);
3831 -- Validate the form of the actual. Note that the call to
3832 -- Is_OK_Variable_For_Out_Formal generates the required
3833 -- reference in this case.
3835 -- A call to an initialization procedure for an aggregate
3836 -- component may initialize a nested component of a constant
3837 -- designated object. In this context the object is variable.
3839 if not Is_OK_Variable_For_Out_Formal (A)
3840 and then not Is_Init_Proc (Nam)
3842 Error_Msg_NE ("actual for& must be a variable", A, F);
3845 -- What's the following about???
3847 if Is_Entity_Name (A) then
3848 Kill_Checks (Entity (A));
3854 if Etype (A) = Any_Type then
3855 Set_Etype (N, Any_Type);
3859 -- Apply appropriate range checks for in, out, and in-out
3860 -- parameters. Out and in-out parameters also need a separate
3861 -- check, if there is a type conversion, to make sure the return
3862 -- value meets the constraints of the variable before the
3865 -- Gigi looks at the check flag and uses the appropriate types.
3866 -- For now since one flag is used there is an optimization which
3867 -- might not be done in the In Out case since Gigi does not do
3868 -- any analysis. More thought required about this ???
3870 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
3872 -- Apply predicate checks, unless this is a call to the
3873 -- predicate check function itself, which would cause an
3874 -- infinite recursion.
3876 if not (Ekind (Nam) = E_Function
3877 and then Has_Predicates (Nam))
3879 Apply_Predicate_Check (A, F_Typ);
3882 -- Apply required constraint checks
3884 if Is_Scalar_Type (Etype (A)) then
3885 Apply_Scalar_Range_Check (A, F_Typ);
3887 elsif Is_Array_Type (Etype (A)) then
3888 Apply_Length_Check (A, F_Typ);
3890 elsif Is_Record_Type (F_Typ)
3891 and then Has_Discriminants (F_Typ)
3892 and then Is_Constrained (F_Typ)
3893 and then (not Is_Derived_Type (F_Typ)
3894 or else Comes_From_Source (Nam))
3896 Apply_Discriminant_Check (A, F_Typ);
3898 elsif Is_Access_Type (F_Typ)
3899 and then Is_Array_Type (Designated_Type (F_Typ))
3900 and then Is_Constrained (Designated_Type (F_Typ))
3902 Apply_Length_Check (A, F_Typ);
3904 elsif Is_Access_Type (F_Typ)
3905 and then Has_Discriminants (Designated_Type (F_Typ))
3906 and then Is_Constrained (Designated_Type (F_Typ))
3908 Apply_Discriminant_Check (A, F_Typ);
3911 Apply_Range_Check (A, F_Typ);
3914 -- Ada 2005 (AI-231): Note that the controlling parameter case
3915 -- already existed in Ada 95, which is partially checked
3916 -- elsewhere (see Checks), and we don't want the warning
3917 -- message to differ.
3919 if Is_Access_Type (F_Typ)
3920 and then Can_Never_Be_Null (F_Typ)
3921 and then Known_Null (A)
3923 if Is_Controlling_Formal (F) then
3924 Apply_Compile_Time_Constraint_Error
3926 Msg => "null value not allowed here?",
3927 Reason => CE_Access_Check_Failed);
3929 elsif Ada_Version >= Ada_2005 then
3930 Apply_Compile_Time_Constraint_Error
3932 Msg => "(Ada 2005) null not allowed in "
3933 & "null-excluding formal?",
3934 Reason => CE_Null_Not_Allowed);
3939 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
3940 if Nkind (A) = N_Type_Conversion then
3941 if Is_Scalar_Type (A_Typ) then
3942 Apply_Scalar_Range_Check
3943 (Expression (A), Etype (Expression (A)), A_Typ);
3946 (Expression (A), Etype (Expression (A)), A_Typ);
3950 if Is_Scalar_Type (F_Typ) then
3951 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3952 elsif Is_Array_Type (F_Typ)
3953 and then Ekind (F) = E_Out_Parameter
3955 Apply_Length_Check (A, F_Typ);
3957 Apply_Range_Check (A, A_Typ, F_Typ);
3962 -- An actual associated with an access parameter is implicitly
3963 -- converted to the anonymous access type of the formal and must
3964 -- satisfy the legality checks for access conversions.
3966 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3967 if not Valid_Conversion (A, F_Typ, A) then
3969 ("invalid implicit conversion for access parameter", A);
3973 -- Check bad case of atomic/volatile argument (RM C.6(12))
3975 if Is_By_Reference_Type (Etype (F))
3976 and then Comes_From_Source (N)
3978 if Is_Atomic_Object (A)
3979 and then not Is_Atomic (Etype (F))
3982 ("cannot pass atomic argument to non-atomic formal&",
3985 elsif Is_Volatile_Object (A)
3986 and then not Is_Volatile (Etype (F))
3989 ("cannot pass volatile argument to non-volatile formal&",
3994 -- Check that subprograms don't have improper controlling
3995 -- arguments (RM 3.9.2 (9)).
3997 -- A primitive operation may have an access parameter of an
3998 -- incomplete tagged type, but a dispatching call is illegal
3999 -- if the type is still incomplete.
4001 if Is_Controlling_Formal (F) then
4002 Set_Is_Controlling_Actual (A);
4004 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4006 Desig : constant Entity_Id := Designated_Type (Etype (F));
4008 if Ekind (Desig) = E_Incomplete_Type
4009 and then No (Full_View (Desig))
4010 and then No (Non_Limited_View (Desig))
4013 ("premature use of incomplete type& " &
4014 "in dispatching call", A, Desig);
4019 elsif Nkind (A) = N_Explicit_Dereference then
4020 Validate_Remote_Access_To_Class_Wide_Type (A);
4023 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4024 and then not Is_Class_Wide_Type (F_Typ)
4025 and then not Is_Controlling_Formal (F)
4027 Error_Msg_N ("class-wide argument not allowed here!", A);
4029 if Is_Subprogram (Nam)
4030 and then Comes_From_Source (Nam)
4032 Error_Msg_Node_2 := F_Typ;
4034 ("& is not a dispatching operation of &!", A, Nam);
4037 -- Apply the checks described in 3.10.2(27): if the context is a
4038 -- specific access-to-object, the actual cannot be class-wide.
4039 -- Use base type to exclude access_to_subprogram cases.
4041 elsif Is_Access_Type (A_Typ)
4042 and then Is_Access_Type (F_Typ)
4043 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4044 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4045 or else (Nkind (A) = N_Attribute_Reference
4047 Is_Class_Wide_Type (Etype (Prefix (A)))))
4048 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4049 and then not Is_Controlling_Formal (F)
4051 -- Disable these checks for call to imported C++ subprograms
4054 (Is_Entity_Name (Name (N))
4055 and then Is_Imported (Entity (Name (N)))
4056 and then Convention (Entity (Name (N))) = Convention_CPP)
4059 ("access to class-wide argument not allowed here!", A);
4061 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4062 Error_Msg_Node_2 := Designated_Type (F_Typ);
4064 ("& is not a dispatching operation of &!", A, Nam);
4070 -- If it is a named association, treat the selector_name as a
4071 -- proper identifier, and mark the corresponding entity. Ignore
4072 -- this reference in Alfa mode, as it refers to an entity not in
4073 -- scope at the point of reference, so the reference should be
4074 -- ignored for computing effects of subprograms.
4076 if Nkind (Parent (A)) = N_Parameter_Association
4077 and then not Alfa_Mode
4079 Set_Entity (Selector_Name (Parent (A)), F);
4080 Generate_Reference (F, Selector_Name (Parent (A)));
4081 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4082 Generate_Reference (F_Typ, N, ' ');
4087 if Ekind (F) /= E_Out_Parameter then
4088 Check_Unset_Reference (A);
4093 -- Case where actual is not present
4101 end Resolve_Actuals;
4103 -----------------------
4104 -- Resolve_Allocator --
4105 -----------------------
4107 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4108 Desig_T : constant Entity_Id := Designated_Type (Typ);
4109 E : constant Node_Id := Expression (N);
4111 Discrim : Entity_Id;
4114 Assoc : Node_Id := Empty;
4117 procedure Check_Allocator_Discrim_Accessibility
4118 (Disc_Exp : Node_Id;
4119 Alloc_Typ : Entity_Id);
4120 -- Check that accessibility level associated with an access discriminant
4121 -- initialized in an allocator by the expression Disc_Exp is not deeper
4122 -- than the level of the allocator type Alloc_Typ. An error message is
4123 -- issued if this condition is violated. Specialized checks are done for
4124 -- the cases of a constraint expression which is an access attribute or
4125 -- an access discriminant.
4127 function In_Dispatching_Context return Boolean;
4128 -- If the allocator is an actual in a call, it is allowed to be class-
4129 -- wide when the context is not because it is a controlling actual.
4131 -------------------------------------------
4132 -- Check_Allocator_Discrim_Accessibility --
4133 -------------------------------------------
4135 procedure Check_Allocator_Discrim_Accessibility
4136 (Disc_Exp : Node_Id;
4137 Alloc_Typ : Entity_Id)
4140 if Type_Access_Level (Etype (Disc_Exp)) >
4141 Deepest_Type_Access_Level (Alloc_Typ)
4144 ("operand type has deeper level than allocator type", Disc_Exp);
4146 -- When the expression is an Access attribute the level of the prefix
4147 -- object must not be deeper than that of the allocator's type.
4149 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4150 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4152 and then Object_Access_Level (Prefix (Disc_Exp)) >
4153 Deepest_Type_Access_Level (Alloc_Typ)
4156 ("prefix of attribute has deeper level than allocator type",
4159 -- When the expression is an access discriminant the check is against
4160 -- the level of the prefix object.
4162 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4163 and then Nkind (Disc_Exp) = N_Selected_Component
4164 and then Object_Access_Level (Prefix (Disc_Exp)) >
4165 Deepest_Type_Access_Level (Alloc_Typ)
4168 ("access discriminant has deeper level than allocator type",
4171 -- All other cases are legal
4176 end Check_Allocator_Discrim_Accessibility;
4178 ----------------------------
4179 -- In_Dispatching_Context --
4180 ----------------------------
4182 function In_Dispatching_Context return Boolean is
4183 Par : constant Node_Id := Parent (N);
4187 Nkind_In (Par, N_Function_Call,
4188 N_Procedure_Call_Statement)
4189 and then Is_Entity_Name (Name (Par))
4190 and then Is_Dispatching_Operation (Entity (Name (Par)));
4191 end In_Dispatching_Context;
4193 -- Start of processing for Resolve_Allocator
4196 -- Replace general access with specific type
4198 if Ekind (Etype (N)) = E_Allocator_Type then
4199 Set_Etype (N, Base_Type (Typ));
4202 if Is_Abstract_Type (Typ) then
4203 Error_Msg_N ("type of allocator cannot be abstract", N);
4206 -- For qualified expression, resolve the expression using the
4207 -- given subtype (nothing to do for type mark, subtype indication)
4209 if Nkind (E) = N_Qualified_Expression then
4210 if Is_Class_Wide_Type (Etype (E))
4211 and then not Is_Class_Wide_Type (Desig_T)
4212 and then not In_Dispatching_Context
4215 ("class-wide allocator not allowed for this access type", N);
4218 Resolve (Expression (E), Etype (E));
4219 Check_Unset_Reference (Expression (E));
4221 -- A qualified expression requires an exact match of the type,
4222 -- class-wide matching is not allowed.
4224 if (Is_Class_Wide_Type (Etype (Expression (E)))
4225 or else Is_Class_Wide_Type (Etype (E)))
4226 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4228 Wrong_Type (Expression (E), Etype (E));
4231 -- Calls to build-in-place functions are not currently supported in
4232 -- allocators for access types associated with a simple storage pool.
4233 -- Supporting such allocators may require passing additional implicit
4234 -- parameters to build-in-place functions (or a significant revision
4235 -- of the current b-i-p implementation to unify the handling for
4236 -- multiple kinds of storage pools). ???
4238 if Is_Immutably_Limited_Type (Desig_T)
4239 and then Nkind (Expression (E)) = N_Function_Call
4242 Pool : constant Entity_Id
4243 := Associated_Storage_Pool (Root_Type (Typ));
4246 and then Present (Get_Rep_Pragma
4247 (Etype (Pool), Name_Simple_Storage_Pool))
4250 ("limited function calls not yet supported in simple " &
4251 "storage pool allocators", Expression (E));
4256 -- A special accessibility check is needed for allocators that
4257 -- constrain access discriminants. The level of the type of the
4258 -- expression used to constrain an access discriminant cannot be
4259 -- deeper than the type of the allocator (in contrast to access
4260 -- parameters, where the level of the actual can be arbitrary).
4262 -- We can't use Valid_Conversion to perform this check because
4263 -- in general the type of the allocator is unrelated to the type
4264 -- of the access discriminant.
4266 if Ekind (Typ) /= E_Anonymous_Access_Type
4267 or else Is_Local_Anonymous_Access (Typ)
4269 Subtyp := Entity (Subtype_Mark (E));
4271 Aggr := Original_Node (Expression (E));
4273 if Has_Discriminants (Subtyp)
4274 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4276 Discrim := First_Discriminant (Base_Type (Subtyp));
4278 -- Get the first component expression of the aggregate
4280 if Present (Expressions (Aggr)) then
4281 Disc_Exp := First (Expressions (Aggr));
4283 elsif Present (Component_Associations (Aggr)) then
4284 Assoc := First (Component_Associations (Aggr));
4286 if Present (Assoc) then
4287 Disc_Exp := Expression (Assoc);
4296 while Present (Discrim) and then Present (Disc_Exp) loop
4297 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4298 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4301 Next_Discriminant (Discrim);
4303 if Present (Discrim) then
4304 if Present (Assoc) then
4306 Disc_Exp := Expression (Assoc);
4308 elsif Present (Next (Disc_Exp)) then
4312 Assoc := First (Component_Associations (Aggr));
4314 if Present (Assoc) then
4315 Disc_Exp := Expression (Assoc);
4325 -- For a subtype mark or subtype indication, freeze the subtype
4328 Freeze_Expression (E);
4330 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4332 ("initialization required for access-to-constant allocator", N);
4335 -- A special accessibility check is needed for allocators that
4336 -- constrain access discriminants. The level of the type of the
4337 -- expression used to constrain an access discriminant cannot be
4338 -- deeper than the type of the allocator (in contrast to access
4339 -- parameters, where the level of the actual can be arbitrary).
4340 -- We can't use Valid_Conversion to perform this check because
4341 -- in general the type of the allocator is unrelated to the type
4342 -- of the access discriminant.
4344 if Nkind (Original_Node (E)) = N_Subtype_Indication
4345 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4346 or else Is_Local_Anonymous_Access (Typ))
4348 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4350 if Has_Discriminants (Subtyp) then
4351 Discrim := First_Discriminant (Base_Type (Subtyp));
4352 Constr := First (Constraints (Constraint (Original_Node (E))));
4353 while Present (Discrim) and then Present (Constr) loop
4354 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4355 if Nkind (Constr) = N_Discriminant_Association then
4356 Disc_Exp := Original_Node (Expression (Constr));
4358 Disc_Exp := Original_Node (Constr);
4361 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4364 Next_Discriminant (Discrim);
4371 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4372 -- check that the level of the type of the created object is not deeper
4373 -- than the level of the allocator's access type, since extensions can
4374 -- now occur at deeper levels than their ancestor types. This is a
4375 -- static accessibility level check; a run-time check is also needed in
4376 -- the case of an initialized allocator with a class-wide argument (see
4377 -- Expand_Allocator_Expression).
4379 if Ada_Version >= Ada_2005
4380 and then Is_Class_Wide_Type (Desig_T)
4383 Exp_Typ : Entity_Id;
4386 if Nkind (E) = N_Qualified_Expression then
4387 Exp_Typ := Etype (E);
4388 elsif Nkind (E) = N_Subtype_Indication then
4389 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4391 Exp_Typ := Entity (E);
4394 if Type_Access_Level (Exp_Typ) >
4395 Deepest_Type_Access_Level (Typ)
4397 if In_Instance_Body then
4398 Error_Msg_N ("?type in allocator has deeper level than" &
4399 " designated class-wide type", E);
4400 Error_Msg_N ("\?Program_Error will be raised at run time",
4403 Make_Raise_Program_Error (Sloc (N),
4404 Reason => PE_Accessibility_Check_Failed));
4407 -- Do not apply Ada 2005 accessibility checks on a class-wide
4408 -- allocator if the type given in the allocator is a formal
4409 -- type. A run-time check will be performed in the instance.
4411 elsif not Is_Generic_Type (Exp_Typ) then
4412 Error_Msg_N ("type in allocator has deeper level than" &
4413 " designated class-wide type", E);
4419 -- Check for allocation from an empty storage pool
4421 if No_Pool_Assigned (Typ) then
4422 Error_Msg_N ("allocation from empty storage pool!", N);
4424 -- If the context is an unchecked conversion, as may happen within an
4425 -- inlined subprogram, the allocator is being resolved with its own
4426 -- anonymous type. In that case, if the target type has a specific
4427 -- storage pool, it must be inherited explicitly by the allocator type.
4429 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4430 and then No (Associated_Storage_Pool (Typ))
4432 Set_Associated_Storage_Pool
4433 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4436 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4437 Check_Restriction (No_Anonymous_Allocators, N);
4440 -- Check that an allocator with task parts isn't for a nested access
4441 -- type when restriction No_Task_Hierarchy applies.
4443 if not Is_Library_Level_Entity (Base_Type (Typ))
4444 and then Has_Task (Base_Type (Desig_T))
4446 Check_Restriction (No_Task_Hierarchy, N);
4449 -- An erroneous allocator may be rewritten as a raise Program_Error
4452 if Nkind (N) = N_Allocator then
4454 -- An anonymous access discriminant is the definition of a
4457 if Ekind (Typ) = E_Anonymous_Access_Type
4458 and then Nkind (Associated_Node_For_Itype (Typ)) =
4459 N_Discriminant_Specification
4462 Discr : constant Entity_Id :=
4463 Defining_Identifier (Associated_Node_For_Itype (Typ));
4466 -- Ada 2012 AI05-0052: If the designated type of the allocator
4467 -- is limited, then the allocator shall not be used to define
4468 -- the value of an access discriminant unless the discriminated
4469 -- type is immutably limited.
4471 if Ada_Version >= Ada_2012
4472 and then Is_Limited_Type (Desig_T)
4473 and then not Is_Immutably_Limited_Type (Scope (Discr))
4476 ("only immutably limited types can have anonymous "
4477 & "access discriminants designating a limited type", N);
4481 -- Avoid marking an allocator as a dynamic coextension if it is
4482 -- within a static construct.
4484 if not Is_Static_Coextension (N) then
4485 Set_Is_Dynamic_Coextension (N);
4488 -- Cleanup for potential static coextensions
4491 Set_Is_Dynamic_Coextension (N, False);
4492 Set_Is_Static_Coextension (N, False);
4496 -- Report a simple error: if the designated object is a local task,
4497 -- its body has not been seen yet, and its activation will fail an
4498 -- elaboration check.
4500 if Is_Task_Type (Desig_T)
4501 and then Scope (Base_Type (Desig_T)) = Current_Scope
4502 and then Is_Compilation_Unit (Current_Scope)
4503 and then Ekind (Current_Scope) = E_Package
4504 and then not In_Package_Body (Current_Scope)
4506 Error_Msg_N ("?cannot activate task before body seen", N);
4507 Error_Msg_N ("\?Program_Error will be raised at run time", N);
4510 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
4511 -- type with a task component on a subpool. This action must raise
4512 -- Program_Error at runtime.
4514 if Ada_Version >= Ada_2012
4515 and then Nkind (N) = N_Allocator
4516 and then Present (Subpool_Handle_Name (N))
4517 and then Has_Task (Desig_T)
4519 Error_Msg_N ("?cannot allocate task on subpool", N);
4520 Error_Msg_N ("\?Program_Error will be raised at run time", N);
4523 Make_Raise_Program_Error (Sloc (N),
4524 Reason => PE_Explicit_Raise));
4527 end Resolve_Allocator;
4529 ---------------------------
4530 -- Resolve_Arithmetic_Op --
4531 ---------------------------
4533 -- Used for resolving all arithmetic operators except exponentiation
4535 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4536 L : constant Node_Id := Left_Opnd (N);
4537 R : constant Node_Id := Right_Opnd (N);
4538 TL : constant Entity_Id := Base_Type (Etype (L));
4539 TR : constant Entity_Id := Base_Type (Etype (R));
4543 B_Typ : constant Entity_Id := Base_Type (Typ);
4544 -- We do the resolution using the base type, because intermediate values
4545 -- in expressions always are of the base type, not a subtype of it.
4547 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4548 -- Returns True if N is in a context that expects "any real type"
4550 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4551 -- Return True iff given type is Integer or universal real/integer
4553 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4554 -- Choose type of integer literal in fixed-point operation to conform
4555 -- to available fixed-point type. T is the type of the other operand,
4556 -- which is needed to determine the expected type of N.
4558 procedure Set_Operand_Type (N : Node_Id);
4559 -- Set operand type to T if universal
4561 -------------------------------
4562 -- Expected_Type_Is_Any_Real --
4563 -------------------------------
4565 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4567 -- N is the expression after "delta" in a fixed_point_definition;
4570 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4571 N_Decimal_Fixed_Point_Definition,
4573 -- N is one of the bounds in a real_range_specification;
4576 N_Real_Range_Specification,
4578 -- N is the expression of a delta_constraint;
4581 N_Delta_Constraint);
4582 end Expected_Type_Is_Any_Real;
4584 -----------------------------
4585 -- Is_Integer_Or_Universal --
4586 -----------------------------
4588 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4590 Index : Interp_Index;
4594 if not Is_Overloaded (N) then
4596 return Base_Type (T) = Base_Type (Standard_Integer)
4597 or else T = Universal_Integer
4598 or else T = Universal_Real;
4600 Get_First_Interp (N, Index, It);
4601 while Present (It.Typ) loop
4602 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4603 or else It.Typ = Universal_Integer
4604 or else It.Typ = Universal_Real
4609 Get_Next_Interp (Index, It);
4614 end Is_Integer_Or_Universal;
4616 ----------------------------
4617 -- Set_Mixed_Mode_Operand --
4618 ----------------------------
4620 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4621 Index : Interp_Index;
4625 if Universal_Interpretation (N) = Universal_Integer then
4627 -- A universal integer literal is resolved as standard integer
4628 -- except in the case of a fixed-point result, where we leave it
4629 -- as universal (to be handled by Exp_Fixd later on)
4631 if Is_Fixed_Point_Type (T) then
4632 Resolve (N, Universal_Integer);
4634 Resolve (N, Standard_Integer);
4637 elsif Universal_Interpretation (N) = Universal_Real
4638 and then (T = Base_Type (Standard_Integer)
4639 or else T = Universal_Integer
4640 or else T = Universal_Real)
4642 -- A universal real can appear in a fixed-type context. We resolve
4643 -- the literal with that context, even though this might raise an
4644 -- exception prematurely (the other operand may be zero).
4648 elsif Etype (N) = Base_Type (Standard_Integer)
4649 and then T = Universal_Real
4650 and then Is_Overloaded (N)
4652 -- Integer arg in mixed-mode operation. Resolve with universal
4653 -- type, in case preference rule must be applied.
4655 Resolve (N, Universal_Integer);
4658 and then B_Typ /= Universal_Fixed
4660 -- Not a mixed-mode operation, resolve with context
4664 elsif Etype (N) = Any_Fixed then
4666 -- N may itself be a mixed-mode operation, so use context type
4670 elsif Is_Fixed_Point_Type (T)
4671 and then B_Typ = Universal_Fixed
4672 and then Is_Overloaded (N)
4674 -- Must be (fixed * fixed) operation, operand must have one
4675 -- compatible interpretation.
4677 Resolve (N, Any_Fixed);
4679 elsif Is_Fixed_Point_Type (B_Typ)
4680 and then (T = Universal_Real
4681 or else Is_Fixed_Point_Type (T))
4682 and then Is_Overloaded (N)
4684 -- C * F(X) in a fixed context, where C is a real literal or a
4685 -- fixed-point expression. F must have either a fixed type
4686 -- interpretation or an integer interpretation, but not both.
4688 Get_First_Interp (N, Index, It);
4689 while Present (It.Typ) loop
4690 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4691 if Analyzed (N) then
4692 Error_Msg_N ("ambiguous operand in fixed operation", N);
4694 Resolve (N, Standard_Integer);
4697 elsif Is_Fixed_Point_Type (It.Typ) then
4698 if Analyzed (N) then
4699 Error_Msg_N ("ambiguous operand in fixed operation", N);
4701 Resolve (N, It.Typ);
4705 Get_Next_Interp (Index, It);
4708 -- Reanalyze the literal with the fixed type of the context. If
4709 -- context is Universal_Fixed, we are within a conversion, leave
4710 -- the literal as a universal real because there is no usable
4711 -- fixed type, and the target of the conversion plays no role in
4725 if B_Typ = Universal_Fixed
4726 and then Nkind (Op2) = N_Real_Literal
4728 T2 := Universal_Real;
4733 Set_Analyzed (Op2, False);
4740 end Set_Mixed_Mode_Operand;
4742 ----------------------
4743 -- Set_Operand_Type --
4744 ----------------------
4746 procedure Set_Operand_Type (N : Node_Id) is
4748 if Etype (N) = Universal_Integer
4749 or else Etype (N) = Universal_Real
4753 end Set_Operand_Type;
4755 -- Start of processing for Resolve_Arithmetic_Op
4758 if Comes_From_Source (N)
4759 and then Ekind (Entity (N)) = E_Function
4760 and then Is_Imported (Entity (N))
4761 and then Is_Intrinsic_Subprogram (Entity (N))
4763 Resolve_Intrinsic_Operator (N, Typ);
4766 -- Special-case for mixed-mode universal expressions or fixed point type
4767 -- operation: each argument is resolved separately. The same treatment
4768 -- is required if one of the operands of a fixed point operation is
4769 -- universal real, since in this case we don't do a conversion to a
4770 -- specific fixed-point type (instead the expander handles the case).
4772 -- Set the type of the node to its universal interpretation because
4773 -- legality checks on an exponentiation operand need the context.
4775 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4776 and then Present (Universal_Interpretation (L))
4777 and then Present (Universal_Interpretation (R))
4779 Set_Etype (N, B_Typ);
4780 Resolve (L, Universal_Interpretation (L));
4781 Resolve (R, Universal_Interpretation (R));
4783 elsif (B_Typ = Universal_Real
4784 or else Etype (N) = Universal_Fixed
4785 or else (Etype (N) = Any_Fixed
4786 and then Is_Fixed_Point_Type (B_Typ))
4787 or else (Is_Fixed_Point_Type (B_Typ)
4788 and then (Is_Integer_Or_Universal (L)
4790 Is_Integer_Or_Universal (R))))
4791 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4793 if TL = Universal_Integer or else TR = Universal_Integer then
4794 Check_For_Visible_Operator (N, B_Typ);
4797 -- If context is a fixed type and one operand is integer, the other
4798 -- is resolved with the type of the context.
4800 if Is_Fixed_Point_Type (B_Typ)
4801 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4802 or else TL = Universal_Integer)
4807 elsif Is_Fixed_Point_Type (B_Typ)
4808 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4809 or else TR = Universal_Integer)
4815 Set_Mixed_Mode_Operand (L, TR);
4816 Set_Mixed_Mode_Operand (R, TL);
4819 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4820 -- multiplying operators from being used when the expected type is
4821 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4822 -- some cases where the expected type is actually Any_Real;
4823 -- Expected_Type_Is_Any_Real takes care of that case.
4825 if Etype (N) = Universal_Fixed
4826 or else Etype (N) = Any_Fixed
4828 if B_Typ = Universal_Fixed
4829 and then not Expected_Type_Is_Any_Real (N)
4830 and then not Nkind_In (Parent (N), N_Type_Conversion,
4831 N_Unchecked_Type_Conversion)
4833 Error_Msg_N ("type cannot be determined from context!", N);
4834 Error_Msg_N ("\explicit conversion to result type required", N);
4836 Set_Etype (L, Any_Type);
4837 Set_Etype (R, Any_Type);
4840 if Ada_Version = Ada_83
4841 and then Etype (N) = Universal_Fixed
4843 Nkind_In (Parent (N), N_Type_Conversion,
4844 N_Unchecked_Type_Conversion)
4847 ("(Ada 83) fixed-point operation "
4848 & "needs explicit conversion", N);
4851 -- The expected type is "any real type" in contexts like
4853 -- type T is delta <universal_fixed-expression> ...
4855 -- in which case we need to set the type to Universal_Real
4856 -- so that static expression evaluation will work properly.
4858 if Expected_Type_Is_Any_Real (N) then
4859 Set_Etype (N, Universal_Real);
4861 Set_Etype (N, B_Typ);
4865 elsif Is_Fixed_Point_Type (B_Typ)
4866 and then (Is_Integer_Or_Universal (L)
4867 or else Nkind (L) = N_Real_Literal
4868 or else Nkind (R) = N_Real_Literal
4869 or else Is_Integer_Or_Universal (R))
4871 Set_Etype (N, B_Typ);
4873 elsif Etype (N) = Any_Fixed then
4875 -- If no previous errors, this is only possible if one operand is
4876 -- overloaded and the context is universal. Resolve as such.
4878 Set_Etype (N, B_Typ);
4882 if (TL = Universal_Integer or else TL = Universal_Real)
4884 (TR = Universal_Integer or else TR = Universal_Real)
4886 Check_For_Visible_Operator (N, B_Typ);
4889 -- If the context is Universal_Fixed and the operands are also
4890 -- universal fixed, this is an error, unless there is only one
4891 -- applicable fixed_point type (usually Duration).
4893 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4894 T := Unique_Fixed_Point_Type (N);
4896 if T = Any_Type then
4909 -- If one of the arguments was resolved to a non-universal type.
4910 -- label the result of the operation itself with the same type.
4911 -- Do the same for the universal argument, if any.
4913 T := Intersect_Types (L, R);
4914 Set_Etype (N, Base_Type (T));
4915 Set_Operand_Type (L);
4916 Set_Operand_Type (R);
4919 Generate_Operator_Reference (N, Typ);
4920 Analyze_Dimension (N);
4921 Eval_Arithmetic_Op (N);
4923 -- In SPARK, a multiplication or division with operands of fixed point
4924 -- types shall be qualified or explicitly converted to identify the
4927 if (Is_Fixed_Point_Type (Etype (L))
4928 or else Is_Fixed_Point_Type (Etype (R)))
4929 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4931 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
4933 Check_SPARK_Restriction
4934 ("operation should be qualified or explicitly converted", N);
4937 -- Set overflow and division checking bit. Much cleverer code needed
4938 -- here eventually and perhaps the Resolve routines should be separated
4939 -- for the various arithmetic operations, since they will need
4940 -- different processing. ???
4942 if Nkind (N) in N_Op then
4943 if not Overflow_Checks_Suppressed (Etype (N)) then
4944 Enable_Overflow_Check (N);
4947 -- Give warning if explicit division by zero
4949 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4950 and then not Division_Checks_Suppressed (Etype (N))
4952 Rop := Right_Opnd (N);
4954 if Compile_Time_Known_Value (Rop)
4955 and then ((Is_Integer_Type (Etype (Rop))
4956 and then Expr_Value (Rop) = Uint_0)
4958 (Is_Real_Type (Etype (Rop))
4959 and then Expr_Value_R (Rop) = Ureal_0))
4961 -- Specialize the warning message according to the operation.
4962 -- The following warnings are for the case
4967 -- For division, we have two cases, for float division
4968 -- of an unconstrained float type, on a machine where
4969 -- Machine_Overflows is false, we don't get an exception
4970 -- at run-time, but rather an infinity or Nan. The Nan
4971 -- case is pretty obscure, so just warn about infinities.
4973 if Is_Floating_Point_Type (Typ)
4974 and then not Is_Constrained (Typ)
4975 and then not Machine_Overflows_On_Target
4978 ("float division by zero, " &
4979 "may generate '+'/'- infinity?", Right_Opnd (N));
4981 -- For all other cases, we get a Constraint_Error
4984 Apply_Compile_Time_Constraint_Error
4985 (N, "division by zero?", CE_Divide_By_Zero,
4986 Loc => Sloc (Right_Opnd (N)));
4990 Apply_Compile_Time_Constraint_Error
4991 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4992 Loc => Sloc (Right_Opnd (N)));
4995 Apply_Compile_Time_Constraint_Error
4996 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4997 Loc => Sloc (Right_Opnd (N)));
4999 -- Division by zero can only happen with division, rem,
5000 -- and mod operations.
5003 raise Program_Error;
5006 -- Otherwise just set the flag to check at run time
5009 Activate_Division_Check (N);
5013 -- If Restriction No_Implicit_Conditionals is active, then it is
5014 -- violated if either operand can be negative for mod, or for rem
5015 -- if both operands can be negative.
5017 if Restriction_Check_Required (No_Implicit_Conditionals)
5018 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5027 -- Set if corresponding operand might be negative
5031 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5032 LNeg := (not OK) or else Lo < 0;
5035 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5036 RNeg := (not OK) or else Lo < 0;
5038 -- Check if we will be generating conditionals. There are two
5039 -- cases where that can happen, first for REM, the only case
5040 -- is largest negative integer mod -1, where the division can
5041 -- overflow, but we still have to give the right result. The
5042 -- front end generates a test for this annoying case. Here we
5043 -- just test if both operands can be negative (that's what the
5044 -- expander does, so we match its logic here).
5046 -- The second case is mod where either operand can be negative.
5047 -- In this case, the back end has to generate additional tests.
5049 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5051 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5053 Check_Restriction (No_Implicit_Conditionals, N);
5059 Check_Unset_Reference (L);
5060 Check_Unset_Reference (R);
5061 end Resolve_Arithmetic_Op;
5067 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5068 Loc : constant Source_Ptr := Sloc (N);
5069 Subp : constant Node_Id := Name (N);
5077 function Same_Or_Aliased_Subprograms
5079 E : Entity_Id) return Boolean;
5080 -- Returns True if the subprogram entity S is the same as E or else
5081 -- S is an alias of E.
5083 ---------------------------------
5084 -- Same_Or_Aliased_Subprograms --
5085 ---------------------------------
5087 function Same_Or_Aliased_Subprograms
5089 E : Entity_Id) return Boolean
5091 Subp_Alias : constant Entity_Id := Alias (S);
5094 or else (Present (Subp_Alias) and then Subp_Alias = E);
5095 end Same_Or_Aliased_Subprograms;
5097 -- Start of processing for Resolve_Call
5100 -- The context imposes a unique interpretation with type Typ on a
5101 -- procedure or function call. Find the entity of the subprogram that
5102 -- yields the expected type, and propagate the corresponding formal
5103 -- constraints on the actuals. The caller has established that an
5104 -- interpretation exists, and emitted an error if not unique.
5106 -- First deal with the case of a call to an access-to-subprogram,
5107 -- dereference made explicit in Analyze_Call.
5109 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5110 if not Is_Overloaded (Subp) then
5111 Nam := Etype (Subp);
5114 -- Find the interpretation whose type (a subprogram type) has a
5115 -- return type that is compatible with the context. Analysis of
5116 -- the node has established that one exists.
5120 Get_First_Interp (Subp, I, It);
5121 while Present (It.Typ) loop
5122 if Covers (Typ, Etype (It.Typ)) then
5127 Get_Next_Interp (I, It);
5131 raise Program_Error;
5135 -- If the prefix is not an entity, then resolve it
5137 if not Is_Entity_Name (Subp) then
5138 Resolve (Subp, Nam);
5141 -- For an indirect call, we always invalidate checks, since we do not
5142 -- know whether the subprogram is local or global. Yes we could do
5143 -- better here, e.g. by knowing that there are no local subprograms,
5144 -- but it does not seem worth the effort. Similarly, we kill all
5145 -- knowledge of current constant values.
5147 Kill_Current_Values;
5149 -- If this is a procedure call which is really an entry call, do
5150 -- the conversion of the procedure call to an entry call. Protected
5151 -- operations use the same circuitry because the name in the call
5152 -- can be an arbitrary expression with special resolution rules.
5154 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5155 or else (Is_Entity_Name (Subp)
5156 and then Ekind (Entity (Subp)) = E_Entry)
5158 Resolve_Entry_Call (N, Typ);
5159 Check_Elab_Call (N);
5161 -- Kill checks and constant values, as above for indirect case
5162 -- Who knows what happens when another task is activated?
5164 Kill_Current_Values;
5167 -- Normal subprogram call with name established in Resolve
5169 elsif not (Is_Type (Entity (Subp))) then
5170 Nam := Entity (Subp);
5171 Set_Entity_With_Style_Check (Subp, Nam);
5173 -- Otherwise we must have the case of an overloaded call
5176 pragma Assert (Is_Overloaded (Subp));
5178 -- Initialize Nam to prevent warning (we know it will be assigned
5179 -- in the loop below, but the compiler does not know that).
5183 Get_First_Interp (Subp, I, It);
5184 while Present (It.Typ) loop
5185 if Covers (Typ, It.Typ) then
5187 Set_Entity_With_Style_Check (Subp, Nam);
5191 Get_Next_Interp (I, It);
5195 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5196 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5197 and then Nkind (Subp) /= N_Explicit_Dereference
5198 and then Present (Parameter_Associations (N))
5200 -- The prefix is a parameterless function call that returns an access
5201 -- to subprogram. If parameters are present in the current call, add
5202 -- add an explicit dereference. We use the base type here because
5203 -- within an instance these may be subtypes.
5205 -- The dereference is added either in Analyze_Call or here. Should
5206 -- be consolidated ???
5208 Set_Is_Overloaded (Subp, False);
5209 Set_Etype (Subp, Etype (Nam));
5210 Insert_Explicit_Dereference (Subp);
5211 Nam := Designated_Type (Etype (Nam));
5212 Resolve (Subp, Nam);
5215 -- Check that a call to Current_Task does not occur in an entry body
5217 if Is_RTE (Nam, RE_Current_Task) then
5226 -- Exclude calls that occur within the default of a formal
5227 -- parameter of the entry, since those are evaluated outside
5230 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5232 if Nkind (P) = N_Entry_Body
5233 or else (Nkind (P) = N_Subprogram_Body
5234 and then Is_Entry_Barrier_Function (P))
5238 ("?& should not be used in entry body (RM C.7(17))",
5241 ("\Program_Error will be raised at run time?", N, Nam);
5243 Make_Raise_Program_Error (Loc,
5244 Reason => PE_Current_Task_In_Entry_Body));
5245 Set_Etype (N, Rtype);
5252 -- Check that a procedure call does not occur in the context of the
5253 -- entry call statement of a conditional or timed entry call. Note that
5254 -- the case of a call to a subprogram renaming of an entry will also be
5255 -- rejected. The test for N not being an N_Entry_Call_Statement is
5256 -- defensive, covering the possibility that the processing of entry
5257 -- calls might reach this point due to later modifications of the code
5260 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5261 and then Nkind (N) /= N_Entry_Call_Statement
5262 and then Entry_Call_Statement (Parent (N)) = N
5264 if Ada_Version < Ada_2005 then
5265 Error_Msg_N ("entry call required in select statement", N);
5267 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5268 -- for a procedure_or_entry_call, the procedure_name or
5269 -- procedure_prefix of the procedure_call_statement shall denote
5270 -- an entry renamed by a procedure, or (a view of) a primitive
5271 -- subprogram of a limited interface whose first parameter is
5272 -- a controlling parameter.
5274 elsif Nkind (N) = N_Procedure_Call_Statement
5275 and then not Is_Renamed_Entry (Nam)
5276 and then not Is_Controlling_Limited_Procedure (Nam)
5279 ("entry call or dispatching primitive of interface required", N);
5283 -- Check that this is not a call to a protected procedure or entry from
5284 -- within a protected function.
5286 if Ekind (Current_Scope) = E_Function
5287 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
5288 and then Ekind (Nam) /= E_Function
5289 and then Scope (Nam) = Scope (Current_Scope)
5291 Error_Msg_N ("within protected function, protected " &
5292 "object is constant", N);
5293 Error_Msg_N ("\cannot call operation that may modify it", N);
5296 -- Freeze the subprogram name if not in a spec-expression. Note that we
5297 -- freeze procedure calls as well as function calls. Procedure calls are
5298 -- not frozen according to the rules (RM 13.14(14)) because it is
5299 -- impossible to have a procedure call to a non-frozen procedure in pure
5300 -- Ada, but in the code that we generate in the expander, this rule
5301 -- needs extending because we can generate procedure calls that need
5304 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
5305 Freeze_Expression (Subp);
5308 -- For a predefined operator, the type of the result is the type imposed
5309 -- by context, except for a predefined operation on universal fixed.
5310 -- Otherwise The type of the call is the type returned by the subprogram
5313 if Is_Predefined_Op (Nam) then
5314 if Etype (N) /= Universal_Fixed then
5318 -- If the subprogram returns an array type, and the context requires the
5319 -- component type of that array type, the node is really an indexing of
5320 -- the parameterless call. Resolve as such. A pathological case occurs
5321 -- when the type of the component is an access to the array type. In
5322 -- this case the call is truly ambiguous.
5324 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5326 ((Is_Array_Type (Etype (Nam))
5327 and then Covers (Typ, Component_Type (Etype (Nam))))
5328 or else (Is_Access_Type (Etype (Nam))
5329 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5333 Component_Type (Designated_Type (Etype (Nam))))))
5336 Index_Node : Node_Id;
5338 Ret_Type : constant Entity_Id := Etype (Nam);
5341 if Is_Access_Type (Ret_Type)
5342 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5345 ("cannot disambiguate function call and indexing", N);
5347 New_Subp := Relocate_Node (Subp);
5348 Set_Entity (Subp, Nam);
5350 if (Is_Array_Type (Ret_Type)
5351 and then Component_Type (Ret_Type) /= Any_Type)
5353 (Is_Access_Type (Ret_Type)
5355 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5357 if Needs_No_Actuals (Nam) then
5359 -- Indexed call to a parameterless function
5362 Make_Indexed_Component (Loc,
5364 Make_Function_Call (Loc,
5366 Expressions => Parameter_Associations (N));
5368 -- An Ada 2005 prefixed call to a primitive operation
5369 -- whose first parameter is the prefix. This prefix was
5370 -- prepended to the parameter list, which is actually a
5371 -- list of indexes. Remove the prefix in order to build
5372 -- the proper indexed component.
5375 Make_Indexed_Component (Loc,
5377 Make_Function_Call (Loc,
5379 Parameter_Associations =>
5381 (Remove_Head (Parameter_Associations (N)))),
5382 Expressions => Parameter_Associations (N));
5385 -- Preserve the parenthesis count of the node
5387 Set_Paren_Count (Index_Node, Paren_Count (N));
5389 -- Since we are correcting a node classification error made
5390 -- by the parser, we call Replace rather than Rewrite.
5392 Replace (N, Index_Node);
5394 Set_Etype (Prefix (N), Ret_Type);
5396 Resolve_Indexed_Component (N, Typ);
5397 Check_Elab_Call (Prefix (N));
5405 Set_Etype (N, Etype (Nam));
5408 -- In the case where the call is to an overloaded subprogram, Analyze
5409 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5410 -- such a case Normalize_Actuals needs to be called once more to order
5411 -- the actuals correctly. Otherwise the call will have the ordering
5412 -- given by the last overloaded subprogram whether this is the correct
5413 -- one being called or not.
5415 if Is_Overloaded (Subp) then
5416 Normalize_Actuals (N, Nam, False, Norm_OK);
5417 pragma Assert (Norm_OK);
5420 -- In any case, call is fully resolved now. Reset Overload flag, to
5421 -- prevent subsequent overload resolution if node is analyzed again
5423 Set_Is_Overloaded (Subp, False);
5424 Set_Is_Overloaded (N, False);
5426 -- If we are calling the current subprogram from immediately within its
5427 -- body, then that is the case where we can sometimes detect cases of
5428 -- infinite recursion statically. Do not try this in case restriction
5429 -- No_Recursion is in effect anyway, and do it only for source calls.
5431 if Comes_From_Source (N) then
5432 Scop := Current_Scope;
5434 -- Issue warning for possible infinite recursion in the absence
5435 -- of the No_Recursion restriction.
5437 if Same_Or_Aliased_Subprograms (Nam, Scop)
5438 and then not Restriction_Active (No_Recursion)
5439 and then Check_Infinite_Recursion (N)
5441 -- Here we detected and flagged an infinite recursion, so we do
5442 -- not need to test the case below for further warnings. Also we
5443 -- are all done if we now have a raise SE node.
5445 if Nkind (N) = N_Raise_Storage_Error then
5449 -- If call is to immediately containing subprogram, then check for
5450 -- the case of a possible run-time detectable infinite recursion.
5453 Scope_Loop : while Scop /= Standard_Standard loop
5454 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5456 -- Although in general case, recursion is not statically
5457 -- checkable, the case of calling an immediately containing
5458 -- subprogram is easy to catch.
5460 Check_Restriction (No_Recursion, N);
5462 -- If the recursive call is to a parameterless subprogram,
5463 -- then even if we can't statically detect infinite
5464 -- recursion, this is pretty suspicious, and we output a
5465 -- warning. Furthermore, we will try later to detect some
5466 -- cases here at run time by expanding checking code (see
5467 -- Detect_Infinite_Recursion in package Exp_Ch6).
5469 -- If the recursive call is within a handler, do not emit a
5470 -- warning, because this is a common idiom: loop until input
5471 -- is correct, catch illegal input in handler and restart.
5473 if No (First_Formal (Nam))
5474 and then Etype (Nam) = Standard_Void_Type
5475 and then not Error_Posted (N)
5476 and then Nkind (Parent (N)) /= N_Exception_Handler
5478 -- For the case of a procedure call. We give the message
5479 -- only if the call is the first statement in a sequence
5480 -- of statements, or if all previous statements are
5481 -- simple assignments. This is simply a heuristic to
5482 -- decrease false positives, without losing too many good
5483 -- warnings. The idea is that these previous statements
5484 -- may affect global variables the procedure depends on.
5485 -- We also exclude raise statements, that may arise from
5486 -- constraint checks and are probably unrelated to the
5487 -- intended control flow.
5489 if Nkind (N) = N_Procedure_Call_Statement
5490 and then Is_List_Member (N)
5496 while Present (P) loop
5498 N_Assignment_Statement,
5499 N_Raise_Constraint_Error)
5509 -- Do not give warning if we are in a conditional context
5512 K : constant Node_Kind := Nkind (Parent (N));
5514 if (K = N_Loop_Statement
5515 and then Present (Iteration_Scheme (Parent (N))))
5516 or else K = N_If_Statement
5517 or else K = N_Elsif_Part
5518 or else K = N_Case_Statement_Alternative
5524 -- Here warning is to be issued
5526 Set_Has_Recursive_Call (Nam);
5528 ("?possible infinite recursion!", N);
5530 ("\?Storage_Error may be raised at run time!", N);
5536 Scop := Scope (Scop);
5537 end loop Scope_Loop;
5541 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5543 Check_Obsolescent_2005_Entity (Nam, Subp);
5545 -- If subprogram name is a predefined operator, it was given in
5546 -- functional notation. Replace call node with operator node, so
5547 -- that actuals can be resolved appropriately.
5549 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5550 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5553 elsif Present (Alias (Nam))
5554 and then Is_Predefined_Op (Alias (Nam))
5556 Resolve_Actuals (N, Nam);
5557 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5561 -- Create a transient scope if the resulting type requires it
5563 -- There are several notable exceptions:
5565 -- a) In init procs, the transient scope overhead is not needed, and is
5566 -- even incorrect when the call is a nested initialization call for a
5567 -- component whose expansion may generate adjust calls. However, if the
5568 -- call is some other procedure call within an initialization procedure
5569 -- (for example a call to Create_Task in the init_proc of the task
5570 -- run-time record) a transient scope must be created around this call.
5572 -- b) Enumeration literal pseudo-calls need no transient scope
5574 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5575 -- functions) do not use the secondary stack even though the return
5576 -- type may be unconstrained.
5578 -- d) Calls to a build-in-place function, since such functions may
5579 -- allocate their result directly in a target object, and cases where
5580 -- the result does get allocated in the secondary stack are checked for
5581 -- within the specialized Exp_Ch6 procedures for expanding those
5582 -- build-in-place calls.
5584 -- e) If the subprogram is marked Inline_Always, then even if it returns
5585 -- an unconstrained type the call does not require use of the secondary
5586 -- stack. However, inlining will only take place if the body to inline
5587 -- is already present. It may not be available if e.g. the subprogram is
5588 -- declared in a child instance.
5590 -- If this is an initialization call for a type whose construction
5591 -- uses the secondary stack, and it is not a nested call to initialize
5592 -- a component, we do need to create a transient scope for it. We
5593 -- check for this by traversing the type in Check_Initialization_Call.
5596 and then Has_Pragma_Inline_Always (Nam)
5597 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5598 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5602 elsif Ekind (Nam) = E_Enumeration_Literal
5603 or else Is_Build_In_Place_Function (Nam)
5604 or else Is_Intrinsic_Subprogram (Nam)
5608 elsif Full_Expander_Active
5609 and then Is_Type (Etype (Nam))
5610 and then Requires_Transient_Scope (Etype (Nam))
5612 (not Within_Init_Proc
5614 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5616 Establish_Transient_Scope (N, Sec_Stack => True);
5618 -- If the call appears within the bounds of a loop, it will
5619 -- be rewritten and reanalyzed, nothing left to do here.
5621 if Nkind (N) /= N_Function_Call then
5625 elsif Is_Init_Proc (Nam)
5626 and then not Within_Init_Proc
5628 Check_Initialization_Call (N, Nam);
5631 -- A protected function cannot be called within the definition of the
5632 -- enclosing protected type.
5634 if Is_Protected_Type (Scope (Nam))
5635 and then In_Open_Scopes (Scope (Nam))
5636 and then not Has_Completion (Scope (Nam))
5639 ("& cannot be called before end of protected definition", N, Nam);
5642 -- Propagate interpretation to actuals, and add default expressions
5645 if Present (First_Formal (Nam)) then
5646 Resolve_Actuals (N, Nam);
5648 -- Overloaded literals are rewritten as function calls, for purpose of
5649 -- resolution. After resolution, we can replace the call with the
5652 elsif Ekind (Nam) = E_Enumeration_Literal then
5653 Copy_Node (Subp, N);
5654 Resolve_Entity_Name (N, Typ);
5656 -- Avoid validation, since it is a static function call
5658 Generate_Reference (Nam, Subp);
5662 -- If the subprogram is not global, then kill all saved values and
5663 -- checks. This is a bit conservative, since in many cases we could do
5664 -- better, but it is not worth the effort. Similarly, we kill constant
5665 -- values. However we do not need to do this for internal entities
5666 -- (unless they are inherited user-defined subprograms), since they
5667 -- are not in the business of molesting local values.
5669 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5670 -- kill all checks and values for calls to global subprograms. This
5671 -- takes care of the case where an access to a local subprogram is
5672 -- taken, and could be passed directly or indirectly and then called
5673 -- from almost any context.
5675 -- Note: we do not do this step till after resolving the actuals. That
5676 -- way we still take advantage of the current value information while
5677 -- scanning the actuals.
5679 -- We suppress killing values if we are processing the nodes associated
5680 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5681 -- type kills all the values as part of analyzing the code that
5682 -- initializes the dispatch tables.
5684 if Inside_Freezing_Actions = 0
5685 and then (not Is_Library_Level_Entity (Nam)
5686 or else Suppress_Value_Tracking_On_Call
5687 (Nearest_Dynamic_Scope (Current_Scope)))
5688 and then (Comes_From_Source (Nam)
5689 or else (Present (Alias (Nam))
5690 and then Comes_From_Source (Alias (Nam))))
5692 Kill_Current_Values;
5695 -- If we are warning about unread OUT parameters, this is the place to
5696 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5697 -- after the above call to Kill_Current_Values (since that call clears
5698 -- the Last_Assignment field of all local variables).
5700 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5701 and then Comes_From_Source (N)
5702 and then In_Extended_Main_Source_Unit (N)
5709 F := First_Formal (Nam);
5710 A := First_Actual (N);
5711 while Present (F) and then Present (A) loop
5712 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
5713 and then Warn_On_Modified_As_Out_Parameter (F)
5714 and then Is_Entity_Name (A)
5715 and then Present (Entity (A))
5716 and then Comes_From_Source (N)
5717 and then Safe_To_Capture_Value (N, Entity (A))
5719 Set_Last_Assignment (Entity (A), A);
5728 -- If the subprogram is a primitive operation, check whether or not
5729 -- it is a correct dispatching call.
5731 if Is_Overloadable (Nam)
5732 and then Is_Dispatching_Operation (Nam)
5734 Check_Dispatching_Call (N);
5736 elsif Ekind (Nam) /= E_Subprogram_Type
5737 and then Is_Abstract_Subprogram (Nam)
5738 and then not In_Instance
5740 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5743 -- If this is a dispatching call, generate the appropriate reference,
5744 -- for better source navigation in GPS.
5746 if Is_Overloadable (Nam)
5747 and then Present (Controlling_Argument (N))
5749 Generate_Reference (Nam, Subp, 'R');
5751 -- Normal case, not a dispatching call: generate a call reference
5754 Generate_Reference (Nam, Subp, 's');
5757 if Is_Intrinsic_Subprogram (Nam) then
5758 Check_Intrinsic_Call (N);
5761 -- Check for violation of restriction No_Specific_Termination_Handlers
5762 -- and warn on a potentially blocking call to Abort_Task.
5764 if Restriction_Check_Required (No_Specific_Termination_Handlers)
5765 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
5767 Is_RTE (Nam, RE_Specific_Handler))
5769 Check_Restriction (No_Specific_Termination_Handlers, N);
5771 elsif Is_RTE (Nam, RE_Abort_Task) then
5772 Check_Potentially_Blocking_Operation (N);
5775 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5776 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5777 -- need to check the second argument to determine whether it is an
5778 -- absolute or relative timing event.
5780 if Restriction_Check_Required (No_Relative_Delay)
5781 and then Is_RTE (Nam, RE_Set_Handler)
5782 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
5784 Check_Restriction (No_Relative_Delay, N);
5787 -- Issue an error for a call to an eliminated subprogram. We skip this
5788 -- in a spec expression, e.g. a call in a default parameter value, since
5789 -- we are not really doing a call at this time. That's important because
5790 -- the spec expression may itself belong to an eliminated subprogram.
5792 if not In_Spec_Expression then
5793 Check_For_Eliminated_Subprogram (Subp, Nam);
5796 -- In formal mode, the primitive operations of a tagged type or type
5797 -- extension do not include functions that return the tagged type.
5799 -- Commented out as the call to Is_Inherited_Operation_For_Type may
5800 -- cause an error because the type entity of the parent node of
5801 -- Entity (Name (N) may not be set. ???
5802 -- So why not just add a guard ???
5804 -- if Nkind (N) = N_Function_Call
5805 -- and then Is_Tagged_Type (Etype (N))
5806 -- and then Is_Entity_Name (Name (N))
5807 -- and then Is_Inherited_Operation_For_Type
5808 -- (Entity (Name (N)), Etype (N))
5810 -- Check_SPARK_Restriction ("function not inherited", N);
5813 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
5814 -- class-wide and the call dispatches on result in a context that does
5815 -- not provide a tag, the call raises Program_Error.
5817 if Nkind (N) = N_Function_Call
5818 and then In_Instance
5819 and then Is_Generic_Actual_Type (Typ)
5820 and then Is_Class_Wide_Type (Typ)
5821 and then Has_Controlling_Result (Nam)
5822 and then Nkind (Parent (N)) = N_Object_Declaration
5824 -- Verify that none of the formals are controlling
5827 Call_OK : Boolean := False;
5831 F := First_Formal (Nam);
5832 while Present (F) loop
5833 if Is_Controlling_Formal (F) then
5842 Error_Msg_N ("!? cannot determine tag of result", N);
5843 Error_Msg_N ("!? Program_Error will be raised", N);
5845 Make_Raise_Program_Error (Sloc (N),
5846 Reason => PE_Explicit_Raise));
5851 Analyze_Dimension (N);
5853 -- All done, evaluate call and deal with elaboration issues
5856 Check_Elab_Call (N);
5857 Warn_On_Overlapping_Actuals (Nam, N);
5860 -----------------------------
5861 -- Resolve_Case_Expression --
5862 -----------------------------
5864 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
5868 Alt := First (Alternatives (N));
5869 while Present (Alt) loop
5870 Resolve (Expression (Alt), Typ);
5875 Eval_Case_Expression (N);
5876 end Resolve_Case_Expression;
5878 -------------------------------
5879 -- Resolve_Character_Literal --
5880 -------------------------------
5882 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5883 B_Typ : constant Entity_Id := Base_Type (Typ);
5887 -- Verify that the character does belong to the type of the context
5889 Set_Etype (N, B_Typ);
5890 Eval_Character_Literal (N);
5892 -- Wide_Wide_Character literals must always be defined, since the set
5893 -- of wide wide character literals is complete, i.e. if a character
5894 -- literal is accepted by the parser, then it is OK for wide wide
5895 -- character (out of range character literals are rejected).
5897 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5900 -- Always accept character literal for type Any_Character, which
5901 -- occurs in error situations and in comparisons of literals, both
5902 -- of which should accept all literals.
5904 elsif B_Typ = Any_Character then
5907 -- For Standard.Character or a type derived from it, check that the
5908 -- literal is in range.
5910 elsif Root_Type (B_Typ) = Standard_Character then
5911 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5915 -- For Standard.Wide_Character or a type derived from it, check that the
5916 -- literal is in range.
5918 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5919 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5923 -- For Standard.Wide_Wide_Character or a type derived from it, we
5924 -- know the literal is in range, since the parser checked!
5926 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5929 -- If the entity is already set, this has already been resolved in a
5930 -- generic context, or comes from expansion. Nothing else to do.
5932 elsif Present (Entity (N)) then
5935 -- Otherwise we have a user defined character type, and we can use the
5936 -- standard visibility mechanisms to locate the referenced entity.
5939 C := Current_Entity (N);
5940 while Present (C) loop
5941 if Etype (C) = B_Typ then
5942 Set_Entity_With_Style_Check (N, C);
5943 Generate_Reference (C, N);
5951 -- If we fall through, then the literal does not match any of the
5952 -- entries of the enumeration type. This isn't just a constraint error
5953 -- situation, it is an illegality (see RM 4.2).
5956 ("character not defined for }", N, First_Subtype (B_Typ));
5957 end Resolve_Character_Literal;
5959 ---------------------------
5960 -- Resolve_Comparison_Op --
5961 ---------------------------
5963 -- Context requires a boolean type, and plays no role in resolution.
5964 -- Processing identical to that for equality operators. The result type is
5965 -- the base type, which matters when pathological subtypes of booleans with
5966 -- limited ranges are used.
5968 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5969 L : constant Node_Id := Left_Opnd (N);
5970 R : constant Node_Id := Right_Opnd (N);
5974 -- If this is an intrinsic operation which is not predefined, use the
5975 -- types of its declared arguments to resolve the possibly overloaded
5976 -- operands. Otherwise the operands are unambiguous and specify the
5979 if Scope (Entity (N)) /= Standard_Standard then
5980 T := Etype (First_Entity (Entity (N)));
5983 T := Find_Unique_Type (L, R);
5985 if T = Any_Fixed then
5986 T := Unique_Fixed_Point_Type (L);
5990 Set_Etype (N, Base_Type (Typ));
5991 Generate_Reference (T, N, ' ');
5993 -- Skip remaining processing if already set to Any_Type
5995 if T = Any_Type then
5999 -- Deal with other error cases
6001 if T = Any_String or else
6002 T = Any_Composite or else
6005 if T = Any_Character then
6006 Ambiguous_Character (L);
6008 Error_Msg_N ("ambiguous operands for comparison", N);
6011 Set_Etype (N, Any_Type);
6015 -- Resolve the operands if types OK
6019 Check_Unset_Reference (L);
6020 Check_Unset_Reference (R);
6021 Generate_Operator_Reference (N, T);
6022 Check_Low_Bound_Tested (N);
6024 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6025 -- types or array types except String.
6027 if Is_Boolean_Type (T) then
6028 Check_SPARK_Restriction
6029 ("comparison is not defined on Boolean type", N);
6031 elsif Is_Array_Type (T)
6032 and then Base_Type (T) /= Standard_String
6034 Check_SPARK_Restriction
6035 ("comparison is not defined on array types other than String", N);
6038 -- Check comparison on unordered enumeration
6040 if Comes_From_Source (N)
6041 and then Bad_Unordered_Enumeration_Reference (N, Etype (L))
6043 Error_Msg_N ("comparison on unordered enumeration type?", N);
6046 -- Evaluate the relation (note we do this after the above check since
6047 -- this Eval call may change N to True/False.
6049 Analyze_Dimension (N);
6050 Eval_Relational_Op (N);
6051 end Resolve_Comparison_Op;
6053 ------------------------------------
6054 -- Resolve_Conditional_Expression --
6055 ------------------------------------
6057 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
6058 Condition : constant Node_Id := First (Expressions (N));
6059 Then_Expr : constant Node_Id := Next (Condition);
6060 Else_Expr : Node_Id := Next (Then_Expr);
6063 Resolve (Condition, Any_Boolean);
6064 Resolve (Then_Expr, Typ);
6066 -- If ELSE expression present, just resolve using the determined type
6068 if Present (Else_Expr) then
6069 Resolve (Else_Expr, Typ);
6071 -- If no ELSE expression is present, root type must be Standard.Boolean
6072 -- and we provide a Standard.True result converted to the appropriate
6073 -- Boolean type (in case it is a derived boolean type).
6075 elsif Root_Type (Typ) = Standard_Boolean then
6077 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
6078 Analyze_And_Resolve (Else_Expr, Typ);
6079 Append_To (Expressions (N), Else_Expr);
6082 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
6083 Append_To (Expressions (N), Error);
6087 Eval_Conditional_Expression (N);
6088 end Resolve_Conditional_Expression;
6090 -----------------------------------------
6091 -- Resolve_Discrete_Subtype_Indication --
6092 -----------------------------------------
6094 procedure Resolve_Discrete_Subtype_Indication
6102 Analyze (Subtype_Mark (N));
6103 S := Entity (Subtype_Mark (N));
6105 if Nkind (Constraint (N)) /= N_Range_Constraint then
6106 Error_Msg_N ("expect range constraint for discrete type", N);
6107 Set_Etype (N, Any_Type);
6110 R := Range_Expression (Constraint (N));
6118 if Base_Type (S) /= Base_Type (Typ) then
6120 ("expect subtype of }", N, First_Subtype (Typ));
6122 -- Rewrite the constraint as a range of Typ
6123 -- to allow compilation to proceed further.
6126 Rewrite (Low_Bound (R),
6127 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6128 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6129 Attribute_Name => Name_First));
6130 Rewrite (High_Bound (R),
6131 Make_Attribute_Reference (Sloc (High_Bound (R)),
6132 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6133 Attribute_Name => Name_First));
6137 Set_Etype (N, Etype (R));
6139 -- Additionally, we must check that the bounds are compatible
6140 -- with the given subtype, which might be different from the
6141 -- type of the context.
6143 Apply_Range_Check (R, S);
6145 -- ??? If the above check statically detects a Constraint_Error
6146 -- it replaces the offending bound(s) of the range R with a
6147 -- Constraint_Error node. When the itype which uses these bounds
6148 -- is frozen the resulting call to Duplicate_Subexpr generates
6149 -- a new temporary for the bounds.
6151 -- Unfortunately there are other itypes that are also made depend
6152 -- on these bounds, so when Duplicate_Subexpr is called they get
6153 -- a forward reference to the newly created temporaries and Gigi
6154 -- aborts on such forward references. This is probably sign of a
6155 -- more fundamental problem somewhere else in either the order of
6156 -- itype freezing or the way certain itypes are constructed.
6158 -- To get around this problem we call Remove_Side_Effects right
6159 -- away if either bounds of R are a Constraint_Error.
6162 L : constant Node_Id := Low_Bound (R);
6163 H : constant Node_Id := High_Bound (R);
6166 if Nkind (L) = N_Raise_Constraint_Error then
6167 Remove_Side_Effects (L);
6170 if Nkind (H) = N_Raise_Constraint_Error then
6171 Remove_Side_Effects (H);
6175 Check_Unset_Reference (Low_Bound (R));
6176 Check_Unset_Reference (High_Bound (R));
6179 end Resolve_Discrete_Subtype_Indication;
6181 -------------------------
6182 -- Resolve_Entity_Name --
6183 -------------------------
6185 -- Used to resolve identifiers and expanded names
6187 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6188 E : constant Entity_Id := Entity (N);
6191 -- If garbage from errors, set to Any_Type and return
6193 if No (E) and then Total_Errors_Detected /= 0 then
6194 Set_Etype (N, Any_Type);
6198 -- Replace named numbers by corresponding literals. Note that this is
6199 -- the one case where Resolve_Entity_Name must reset the Etype, since
6200 -- it is currently marked as universal.
6202 if Ekind (E) = E_Named_Integer then
6204 Eval_Named_Integer (N);
6206 elsif Ekind (E) = E_Named_Real then
6208 Eval_Named_Real (N);
6210 -- For enumeration literals, we need to make sure that a proper style
6211 -- check is done, since such literals are overloaded, and thus we did
6212 -- not do a style check during the first phase of analysis.
6214 elsif Ekind (E) = E_Enumeration_Literal then
6215 Set_Entity_With_Style_Check (N, E);
6216 Eval_Entity_Name (N);
6218 -- Case of subtype name appearing as an operand in expression
6220 elsif Is_Type (E) then
6222 -- Allow use of subtype if it is a concurrent type where we are
6223 -- currently inside the body. This will eventually be expanded into a
6224 -- call to Self (for tasks) or _object (for protected objects). Any
6225 -- other use of a subtype is invalid.
6227 if Is_Concurrent_Type (E)
6228 and then In_Open_Scopes (E)
6232 -- Any other use is an error
6236 ("invalid use of subtype mark in expression or call", N);
6239 -- Check discriminant use if entity is discriminant in current scope,
6240 -- i.e. discriminant of record or concurrent type currently being
6241 -- analyzed. Uses in corresponding body are unrestricted.
6243 elsif Ekind (E) = E_Discriminant
6244 and then Scope (E) = Current_Scope
6245 and then not Has_Completion (Current_Scope)
6247 Check_Discriminant_Use (N);
6249 -- A parameterless generic function cannot appear in a context that
6250 -- requires resolution.
6252 elsif Ekind (E) = E_Generic_Function then
6253 Error_Msg_N ("illegal use of generic function", N);
6255 elsif Ekind (E) = E_Out_Parameter
6256 and then Ada_Version = Ada_83
6257 and then (Nkind (Parent (N)) in N_Op
6258 or else (Nkind (Parent (N)) = N_Assignment_Statement
6259 and then N = Expression (Parent (N)))
6260 or else Nkind (Parent (N)) = N_Explicit_Dereference)
6262 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6264 -- In all other cases, just do the possible static evaluation
6267 -- A deferred constant that appears in an expression must have a
6268 -- completion, unless it has been removed by in-place expansion of
6271 if Ekind (E) = E_Constant
6272 and then Comes_From_Source (E)
6273 and then No (Constant_Value (E))
6274 and then Is_Frozen (Etype (E))
6275 and then not In_Spec_Expression
6276 and then not Is_Imported (E)
6278 if No_Initialization (Parent (E))
6279 or else (Present (Full_View (E))
6280 and then No_Initialization (Parent (Full_View (E))))
6285 "deferred constant is frozen before completion", N);
6289 Eval_Entity_Name (N);
6291 end Resolve_Entity_Name;
6297 procedure Resolve_Entry (Entry_Name : Node_Id) is
6298 Loc : constant Source_Ptr := Sloc (Entry_Name);
6306 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6307 -- If the bounds of the entry family being called depend on task
6308 -- discriminants, build a new index subtype where a discriminant is
6309 -- replaced with the value of the discriminant of the target task.
6310 -- The target task is the prefix of the entry name in the call.
6312 -----------------------
6313 -- Actual_Index_Type --
6314 -----------------------
6316 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
6317 Typ : constant Entity_Id := Entry_Index_Type (E);
6318 Tsk : constant Entity_Id := Scope (E);
6319 Lo : constant Node_Id := Type_Low_Bound (Typ);
6320 Hi : constant Node_Id := Type_High_Bound (Typ);
6323 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6324 -- If the bound is given by a discriminant, replace with a reference
6325 -- to the discriminant of the same name in the target task. If the
6326 -- entry name is the target of a requeue statement and the entry is
6327 -- in the current protected object, the bound to be used is the
6328 -- discriminal of the object (see Apply_Range_Checks for details of
6329 -- the transformation).
6331 -----------------------------
6332 -- Actual_Discriminant_Ref --
6333 -----------------------------
6335 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
6336 Typ : constant Entity_Id := Etype (Bound);
6340 Remove_Side_Effects (Bound);
6342 if not Is_Entity_Name (Bound)
6343 or else Ekind (Entity (Bound)) /= E_Discriminant
6347 elsif Is_Protected_Type (Tsk)
6348 and then In_Open_Scopes (Tsk)
6349 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6351 -- Note: here Bound denotes a discriminant of the corresponding
6352 -- record type tskV, whose discriminal is a formal of the
6353 -- init-proc tskVIP. What we want is the body discriminal,
6354 -- which is associated to the discriminant of the original
6355 -- concurrent type tsk.
6357 return New_Occurrence_Of
6358 (Find_Body_Discriminal (Entity (Bound)), Loc);
6362 Make_Selected_Component (Loc,
6363 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6364 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6369 end Actual_Discriminant_Ref;
6371 -- Start of processing for Actual_Index_Type
6374 if not Has_Discriminants (Tsk)
6375 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
6377 return Entry_Index_Type (E);
6380 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6381 Set_Etype (New_T, Base_Type (Typ));
6382 Set_Size_Info (New_T, Typ);
6383 Set_RM_Size (New_T, RM_Size (Typ));
6384 Set_Scalar_Range (New_T,
6385 Make_Range (Sloc (Entry_Name),
6386 Low_Bound => Actual_Discriminant_Ref (Lo),
6387 High_Bound => Actual_Discriminant_Ref (Hi)));
6391 end Actual_Index_Type;
6393 -- Start of processing of Resolve_Entry
6396 -- Find name of entry being called, and resolve prefix of name with its
6397 -- own type. The prefix can be overloaded, and the name and signature of
6398 -- the entry must be taken into account.
6400 if Nkind (Entry_Name) = N_Indexed_Component then
6402 -- Case of dealing with entry family within the current tasks
6404 E_Name := Prefix (Entry_Name);
6407 E_Name := Entry_Name;
6410 if Is_Entity_Name (E_Name) then
6412 -- Entry call to an entry (or entry family) in the current task. This
6413 -- is legal even though the task will deadlock. Rewrite as call to
6416 -- This can also be a call to an entry in an enclosing task. If this
6417 -- is a single task, we have to retrieve its name, because the scope
6418 -- of the entry is the task type, not the object. If the enclosing
6419 -- task is a task type, the identity of the task is given by its own
6422 -- Finally this can be a requeue on an entry of the same task or
6423 -- protected object.
6425 S := Scope (Entity (E_Name));
6427 for J in reverse 0 .. Scope_Stack.Last loop
6428 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6429 and then not Comes_From_Source (S)
6431 -- S is an enclosing task or protected object. The concurrent
6432 -- declaration has been converted into a type declaration, and
6433 -- the object itself has an object declaration that follows
6434 -- the type in the same declarative part.
6436 Tsk := Next_Entity (S);
6437 while Etype (Tsk) /= S loop
6444 elsif S = Scope_Stack.Table (J).Entity then
6446 -- Call to current task. Will be transformed into call to Self
6454 Make_Selected_Component (Loc,
6455 Prefix => New_Occurrence_Of (S, Loc),
6457 New_Occurrence_Of (Entity (E_Name), Loc));
6458 Rewrite (E_Name, New_N);
6461 elsif Nkind (Entry_Name) = N_Selected_Component
6462 and then Is_Overloaded (Prefix (Entry_Name))
6464 -- Use the entry name (which must be unique at this point) to find
6465 -- the prefix that returns the corresponding task/protected type.
6468 Pref : constant Node_Id := Prefix (Entry_Name);
6469 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
6474 Get_First_Interp (Pref, I, It);
6475 while Present (It.Typ) loop
6476 if Scope (Ent) = It.Typ then
6477 Set_Etype (Pref, It.Typ);
6481 Get_Next_Interp (I, It);
6486 if Nkind (Entry_Name) = N_Selected_Component then
6487 Resolve (Prefix (Entry_Name));
6489 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6490 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6491 Resolve (Prefix (Prefix (Entry_Name)));
6492 Index := First (Expressions (Entry_Name));
6493 Resolve (Index, Entry_Index_Type (Nam));
6495 -- Up to this point the expression could have been the actual in a
6496 -- simple entry call, and be given by a named association.
6498 if Nkind (Index) = N_Parameter_Association then
6499 Error_Msg_N ("expect expression for entry index", Index);
6501 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6506 ------------------------
6507 -- Resolve_Entry_Call --
6508 ------------------------
6510 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6511 Entry_Name : constant Node_Id := Name (N);
6512 Loc : constant Source_Ptr := Sloc (Entry_Name);
6514 First_Named : Node_Id;
6521 -- We kill all checks here, because it does not seem worth the effort to
6522 -- do anything better, an entry call is a big operation.
6526 -- Processing of the name is similar for entry calls and protected
6527 -- operation calls. Once the entity is determined, we can complete
6528 -- the resolution of the actuals.
6530 -- The selector may be overloaded, in the case of a protected object
6531 -- with overloaded functions. The type of the context is used for
6534 if Nkind (Entry_Name) = N_Selected_Component
6535 and then Is_Overloaded (Selector_Name (Entry_Name))
6536 and then Typ /= Standard_Void_Type
6543 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6544 while Present (It.Typ) loop
6545 if Covers (Typ, It.Typ) then
6546 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6547 Set_Etype (Entry_Name, It.Typ);
6549 Generate_Reference (It.Typ, N, ' ');
6552 Get_Next_Interp (I, It);
6557 Resolve_Entry (Entry_Name);
6559 if Nkind (Entry_Name) = N_Selected_Component then
6561 -- Simple entry call
6563 Nam := Entity (Selector_Name (Entry_Name));
6564 Obj := Prefix (Entry_Name);
6565 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6567 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6569 -- Call to member of entry family
6571 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6572 Obj := Prefix (Prefix (Entry_Name));
6573 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6576 -- We cannot in general check the maximum depth of protected entry calls
6577 -- at compile time. But we can tell that any protected entry call at all
6578 -- violates a specified nesting depth of zero.
6580 if Is_Protected_Type (Scope (Nam)) then
6581 Check_Restriction (Max_Entry_Queue_Length, N);
6584 -- Use context type to disambiguate a protected function that can be
6585 -- called without actuals and that returns an array type, and where the
6586 -- argument list may be an indexing of the returned value.
6588 if Ekind (Nam) = E_Function
6589 and then Needs_No_Actuals (Nam)
6590 and then Present (Parameter_Associations (N))
6592 ((Is_Array_Type (Etype (Nam))
6593 and then Covers (Typ, Component_Type (Etype (Nam))))
6595 or else (Is_Access_Type (Etype (Nam))
6596 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6600 Component_Type (Designated_Type (Etype (Nam))))))
6603 Index_Node : Node_Id;
6607 Make_Indexed_Component (Loc,
6609 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
6610 Expressions => Parameter_Associations (N));
6612 -- Since we are correcting a node classification error made by the
6613 -- parser, we call Replace rather than Rewrite.
6615 Replace (N, Index_Node);
6616 Set_Etype (Prefix (N), Etype (Nam));
6618 Resolve_Indexed_Component (N, Typ);
6623 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6624 and then Present (PPC_Wrapper (Nam))
6625 and then Current_Scope /= PPC_Wrapper (Nam)
6627 -- Rewrite as call to the precondition wrapper, adding the task
6628 -- object to the list of actuals. If the call is to a member of an
6629 -- entry family, include the index as well.
6633 New_Actuals : List_Id;
6636 New_Actuals := New_List (Obj);
6638 if Nkind (Entry_Name) = N_Indexed_Component then
6639 Append_To (New_Actuals,
6640 New_Copy_Tree (First (Expressions (Entry_Name))));
6643 Append_List (Parameter_Associations (N), New_Actuals);
6645 Make_Procedure_Call_Statement (Loc,
6647 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6648 Parameter_Associations => New_Actuals);
6649 Rewrite (N, New_Call);
6650 Analyze_And_Resolve (N);
6655 -- The operation name may have been overloaded. Order the actuals
6656 -- according to the formals of the resolved entity, and set the return
6657 -- type to that of the operation.
6660 Normalize_Actuals (N, Nam, False, Norm_OK);
6661 pragma Assert (Norm_OK);
6662 Set_Etype (N, Etype (Nam));
6665 Resolve_Actuals (N, Nam);
6667 -- Create a call reference to the entry
6669 Generate_Reference (Nam, Entry_Name, 's');
6671 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
6672 Check_Potentially_Blocking_Operation (N);
6675 -- Verify that a procedure call cannot masquerade as an entry
6676 -- call where an entry call is expected.
6678 if Ekind (Nam) = E_Procedure then
6679 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6680 and then N = Entry_Call_Statement (Parent (N))
6682 Error_Msg_N ("entry call required in select statement", N);
6684 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6685 and then N = Triggering_Statement (Parent (N))
6687 Error_Msg_N ("triggering statement cannot be procedure call", N);
6689 elsif Ekind (Scope (Nam)) = E_Task_Type
6690 and then not In_Open_Scopes (Scope (Nam))
6692 Error_Msg_N ("task has no entry with this name", Entry_Name);
6696 -- After resolution, entry calls and protected procedure calls are
6697 -- changed into entry calls, for expansion. The structure of the node
6698 -- does not change, so it can safely be done in place. Protected
6699 -- function calls must keep their structure because they are
6702 if Ekind (Nam) /= E_Function then
6704 -- A protected operation that is not a function may modify the
6705 -- corresponding object, and cannot apply to a constant. If this
6706 -- is an internal call, the prefix is the type itself.
6708 if Is_Protected_Type (Scope (Nam))
6709 and then not Is_Variable (Obj)
6710 and then (not Is_Entity_Name (Obj)
6711 or else not Is_Type (Entity (Obj)))
6714 ("prefix of protected procedure or entry call must be variable",
6718 Actuals := Parameter_Associations (N);
6719 First_Named := First_Named_Actual (N);
6722 Make_Entry_Call_Statement (Loc,
6724 Parameter_Associations => Actuals));
6726 Set_First_Named_Actual (N, First_Named);
6727 Set_Analyzed (N, True);
6729 -- Protected functions can return on the secondary stack, in which
6730 -- case we must trigger the transient scope mechanism.
6732 elsif Full_Expander_Active
6733 and then Requires_Transient_Scope (Etype (Nam))
6735 Establish_Transient_Scope (N, Sec_Stack => True);
6737 end Resolve_Entry_Call;
6739 -------------------------
6740 -- Resolve_Equality_Op --
6741 -------------------------
6743 -- Both arguments must have the same type, and the boolean context does
6744 -- not participate in the resolution. The first pass verifies that the
6745 -- interpretation is not ambiguous, and the type of the left argument is
6746 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6747 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6748 -- though they carry a single (universal) type. Diagnose this case here.
6750 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6751 L : constant Node_Id := Left_Opnd (N);
6752 R : constant Node_Id := Right_Opnd (N);
6753 T : Entity_Id := Find_Unique_Type (L, R);
6755 procedure Check_Conditional_Expression (Cond : Node_Id);
6756 -- The resolution rule for conditional expressions requires that each
6757 -- such must have a unique type. This means that if several dependent
6758 -- expressions are of a non-null anonymous access type, and the context
6759 -- does not impose an expected type (as can be the case in an equality
6760 -- operation) the expression must be rejected.
6762 function Find_Unique_Access_Type return Entity_Id;
6763 -- In the case of allocators, make a last-ditch attempt to find a single
6764 -- access type with the right designated type. This is semantically
6765 -- dubious, and of no interest to any real code, but c48008a makes it
6768 ----------------------------------
6769 -- Check_Conditional_Expression --
6770 ----------------------------------
6772 procedure Check_Conditional_Expression (Cond : Node_Id) is
6773 Then_Expr : Node_Id;
6774 Else_Expr : Node_Id;
6777 if Nkind (Cond) = N_Conditional_Expression then
6778 Then_Expr := Next (First (Expressions (Cond)));
6779 Else_Expr := Next (Then_Expr);
6781 if Nkind (Then_Expr) /= N_Null
6782 and then Nkind (Else_Expr) /= N_Null
6785 ("cannot determine type of conditional expression", Cond);
6788 end Check_Conditional_Expression;
6790 -----------------------------
6791 -- Find_Unique_Access_Type --
6792 -----------------------------
6794 function Find_Unique_Access_Type return Entity_Id is
6800 if Ekind (Etype (R)) = E_Allocator_Type then
6801 Acc := Designated_Type (Etype (R));
6802 elsif Ekind (Etype (L)) = E_Allocator_Type then
6803 Acc := Designated_Type (Etype (L));
6809 while S /= Standard_Standard loop
6810 E := First_Entity (S);
6811 while Present (E) loop
6813 and then Is_Access_Type (E)
6814 and then Ekind (E) /= E_Allocator_Type
6815 and then Designated_Type (E) = Base_Type (Acc)
6827 end Find_Unique_Access_Type;
6829 -- Start of processing for Resolve_Equality_Op
6832 Set_Etype (N, Base_Type (Typ));
6833 Generate_Reference (T, N, ' ');
6835 if T = Any_Fixed then
6836 T := Unique_Fixed_Point_Type (L);
6839 if T /= Any_Type then
6840 if T = Any_String or else
6841 T = Any_Composite or else
6844 if T = Any_Character then
6845 Ambiguous_Character (L);
6847 Error_Msg_N ("ambiguous operands for equality", N);
6850 Set_Etype (N, Any_Type);
6853 elsif T = Any_Access
6854 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
6856 T := Find_Unique_Access_Type;
6859 Error_Msg_N ("ambiguous operands for equality", N);
6860 Set_Etype (N, Any_Type);
6864 -- Conditional expressions must have a single type, and if the
6865 -- context does not impose one the dependent expressions cannot
6866 -- be anonymous access types.
6868 elsif Ada_Version >= Ada_2012
6869 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
6870 E_Anonymous_Access_Subprogram_Type)
6871 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
6872 E_Anonymous_Access_Subprogram_Type)
6874 Check_Conditional_Expression (L);
6875 Check_Conditional_Expression (R);
6881 -- In SPARK, equality operators = and /= for array types other than
6882 -- String are only defined when, for each index position, the
6883 -- operands have equal static bounds.
6885 if Is_Array_Type (T) then
6886 -- Protect call to Matching_Static_Array_Bounds to avoid costly
6887 -- operation if not needed.
6889 if Restriction_Check_Required (SPARK)
6890 and then Base_Type (T) /= Standard_String
6891 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
6892 and then Etype (L) /= Any_Composite -- or else L in error
6893 and then Etype (R) /= Any_Composite -- or else R in error
6894 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
6896 Check_SPARK_Restriction
6897 ("array types should have matching static bounds", N);
6901 -- If the unique type is a class-wide type then it will be expanded
6902 -- into a dispatching call to the predefined primitive. Therefore we
6903 -- check here for potential violation of such restriction.
6905 if Is_Class_Wide_Type (T) then
6906 Check_Restriction (No_Dispatching_Calls, N);
6909 if Warn_On_Redundant_Constructs
6910 and then Comes_From_Source (N)
6911 and then Is_Entity_Name (R)
6912 and then Entity (R) = Standard_True
6913 and then Comes_From_Source (R)
6915 Error_Msg_N -- CODEFIX
6916 ("?comparison with True is redundant!", R);
6919 Check_Unset_Reference (L);
6920 Check_Unset_Reference (R);
6921 Generate_Operator_Reference (N, T);
6922 Check_Low_Bound_Tested (N);
6924 -- If this is an inequality, it may be the implicit inequality
6925 -- created for a user-defined operation, in which case the corres-
6926 -- ponding equality operation is not intrinsic, and the operation
6927 -- cannot be constant-folded. Else fold.
6929 if Nkind (N) = N_Op_Eq
6930 or else Comes_From_Source (Entity (N))
6931 or else Ekind (Entity (N)) = E_Operator
6932 or else Is_Intrinsic_Subprogram
6933 (Corresponding_Equality (Entity (N)))
6935 Analyze_Dimension (N);
6936 Eval_Relational_Op (N);
6938 elsif Nkind (N) = N_Op_Ne
6939 and then Is_Abstract_Subprogram (Entity (N))
6941 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6944 -- Ada 2005: If one operand is an anonymous access type, convert the
6945 -- other operand to it, to ensure that the underlying types match in
6946 -- the back-end. Same for access_to_subprogram, and the conversion
6947 -- verifies that the types are subtype conformant.
6949 -- We apply the same conversion in the case one of the operands is a
6950 -- private subtype of the type of the other.
6952 -- Why the Expander_Active test here ???
6954 if Full_Expander_Active
6956 (Ekind_In (T, E_Anonymous_Access_Type,
6957 E_Anonymous_Access_Subprogram_Type)
6958 or else Is_Private_Type (T))
6960 if Etype (L) /= T then
6962 Make_Unchecked_Type_Conversion (Sloc (L),
6963 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6964 Expression => Relocate_Node (L)));
6965 Analyze_And_Resolve (L, T);
6968 if (Etype (R)) /= T then
6970 Make_Unchecked_Type_Conversion (Sloc (R),
6971 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6972 Expression => Relocate_Node (R)));
6973 Analyze_And_Resolve (R, T);
6977 end Resolve_Equality_Op;
6979 ----------------------------------
6980 -- Resolve_Explicit_Dereference --
6981 ----------------------------------
6983 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6984 Loc : constant Source_Ptr := Sloc (N);
6986 P : constant Node_Id := Prefix (N);
6991 Check_Fully_Declared_Prefix (Typ, P);
6993 if Is_Overloaded (P) then
6995 -- Use the context type to select the prefix that has the correct
6998 Get_First_Interp (P, I, It);
6999 while Present (It.Typ) loop
7000 exit when Is_Access_Type (It.Typ)
7001 and then Covers (Typ, Designated_Type (It.Typ));
7002 Get_Next_Interp (I, It);
7005 if Present (It.Typ) then
7006 Resolve (P, It.Typ);
7008 -- If no interpretation covers the designated type of the prefix,
7009 -- this is the pathological case where not all implementations of
7010 -- the prefix allow the interpretation of the node as a call. Now
7011 -- that the expected type is known, Remove other interpretations
7012 -- from prefix, rewrite it as a call, and resolve again, so that
7013 -- the proper call node is generated.
7015 Get_First_Interp (P, I, It);
7016 while Present (It.Typ) loop
7017 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
7021 Get_Next_Interp (I, It);
7025 Make_Function_Call (Loc,
7027 Make_Explicit_Dereference (Loc,
7029 Parameter_Associations => New_List);
7031 Save_Interps (N, New_N);
7033 Analyze_And_Resolve (N, Typ);
7037 Set_Etype (N, Designated_Type (It.Typ));
7043 if Is_Access_Type (Etype (P)) then
7044 Apply_Access_Check (N);
7047 -- If the designated type is a packed unconstrained array type, and the
7048 -- explicit dereference is not in the context of an attribute reference,
7049 -- then we must compute and set the actual subtype, since it is needed
7050 -- by Gigi. The reason we exclude the attribute case is that this is
7051 -- handled fine by Gigi, and in fact we use such attributes to build the
7052 -- actual subtype. We also exclude generated code (which builds actual
7053 -- subtypes directly if they are needed).
7055 if Is_Array_Type (Etype (N))
7056 and then Is_Packed (Etype (N))
7057 and then not Is_Constrained (Etype (N))
7058 and then Nkind (Parent (N)) /= N_Attribute_Reference
7059 and then Comes_From_Source (N)
7061 Set_Etype (N, Get_Actual_Subtype (N));
7064 -- Note: No Eval processing is required for an explicit dereference,
7065 -- because such a name can never be static.
7067 end Resolve_Explicit_Dereference;
7069 -------------------------------------
7070 -- Resolve_Expression_With_Actions --
7071 -------------------------------------
7073 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
7076 end Resolve_Expression_With_Actions;
7078 -------------------------------
7079 -- Resolve_Indexed_Component --
7080 -------------------------------
7082 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
7083 Name : constant Node_Id := Prefix (N);
7085 Array_Type : Entity_Id := Empty; -- to prevent junk warning
7089 if Is_Overloaded (Name) then
7091 -- Use the context type to select the prefix that yields the correct
7097 I1 : Interp_Index := 0;
7098 P : constant Node_Id := Prefix (N);
7099 Found : Boolean := False;
7102 Get_First_Interp (P, I, It);
7103 while Present (It.Typ) loop
7104 if (Is_Array_Type (It.Typ)
7105 and then Covers (Typ, Component_Type (It.Typ)))
7106 or else (Is_Access_Type (It.Typ)
7107 and then Is_Array_Type (Designated_Type (It.Typ))
7111 Component_Type (Designated_Type (It.Typ))))
7114 It := Disambiguate (P, I1, I, Any_Type);
7116 if It = No_Interp then
7117 Error_Msg_N ("ambiguous prefix for indexing", N);
7123 Array_Type := It.Typ;
7129 Array_Type := It.Typ;
7134 Get_Next_Interp (I, It);
7139 Array_Type := Etype (Name);
7142 Resolve (Name, Array_Type);
7143 Array_Type := Get_Actual_Subtype_If_Available (Name);
7145 -- If prefix is access type, dereference to get real array type.
7146 -- Note: we do not apply an access check because the expander always
7147 -- introduces an explicit dereference, and the check will happen there.
7149 if Is_Access_Type (Array_Type) then
7150 Array_Type := Designated_Type (Array_Type);
7153 -- If name was overloaded, set component type correctly now
7154 -- If a misplaced call to an entry family (which has no index types)
7155 -- return. Error will be diagnosed from calling context.
7157 if Is_Array_Type (Array_Type) then
7158 Set_Etype (N, Component_Type (Array_Type));
7163 Index := First_Index (Array_Type);
7164 Expr := First (Expressions (N));
7166 -- The prefix may have resolved to a string literal, in which case its
7167 -- etype has a special representation. This is only possible currently
7168 -- if the prefix is a static concatenation, written in functional
7171 if Ekind (Array_Type) = E_String_Literal_Subtype then
7172 Resolve (Expr, Standard_Positive);
7175 while Present (Index) and Present (Expr) loop
7176 Resolve (Expr, Etype (Index));
7177 Check_Unset_Reference (Expr);
7179 if Is_Scalar_Type (Etype (Expr)) then
7180 Apply_Scalar_Range_Check (Expr, Etype (Index));
7182 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
7190 Analyze_Dimension (N);
7192 -- Do not generate the warning on suspicious index if we are analyzing
7193 -- package Ada.Tags; otherwise we will report the warning with the
7194 -- Prims_Ptr field of the dispatch table.
7196 if Scope (Etype (Prefix (N))) = Standard_Standard
7198 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
7201 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
7202 Eval_Indexed_Component (N);
7205 -- If the array type is atomic, and is packed, and we are in a left side
7206 -- context, then this is worth a warning, since we have a situation
7207 -- where the access to the component may cause extra read/writes of
7208 -- the atomic array object, which could be considered unexpected.
7210 if Nkind (N) = N_Indexed_Component
7211 and then (Is_Atomic (Array_Type)
7212 or else (Is_Entity_Name (Prefix (N))
7213 and then Is_Atomic (Entity (Prefix (N)))))
7214 and then Is_Bit_Packed_Array (Array_Type)
7217 Error_Msg_N ("?assignment to component of packed atomic array",
7219 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
7222 end Resolve_Indexed_Component;
7224 -----------------------------
7225 -- Resolve_Integer_Literal --
7226 -----------------------------
7228 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7231 Eval_Integer_Literal (N);
7232 end Resolve_Integer_Literal;
7234 --------------------------------
7235 -- Resolve_Intrinsic_Operator --
7236 --------------------------------
7238 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
7239 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7241 Orig_Op : constant Entity_Id := Entity (N);
7245 function Convert_Operand (Opnd : Node_Id) return Node_Id;
7246 -- If the operand is a literal, it cannot be the expression in a
7247 -- conversion. Use a qualified expression instead.
7249 function Convert_Operand (Opnd : Node_Id) return Node_Id is
7250 Loc : constant Source_Ptr := Sloc (Opnd);
7253 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
7255 Make_Qualified_Expression (Loc,
7256 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7257 Expression => Relocate_Node (Opnd));
7261 Res := Unchecked_Convert_To (Btyp, Opnd);
7265 end Convert_Operand;
7267 -- Start of processing for Resolve_Intrinsic_Operator
7270 -- We must preserve the original entity in a generic setting, so that
7271 -- the legality of the operation can be verified in an instance.
7273 if not Full_Expander_Active then
7278 while Scope (Op) /= Standard_Standard loop
7280 pragma Assert (Present (Op));
7284 Set_Is_Overloaded (N, False);
7286 -- If the result or operand types are private, rewrite with unchecked
7287 -- conversions on the operands and the result, to expose the proper
7288 -- underlying numeric type.
7290 if Is_Private_Type (Typ)
7291 or else Is_Private_Type (Etype (Left_Opnd (N)))
7292 or else Is_Private_Type (Etype (Right_Opnd (N)))
7294 Arg1 := Convert_Operand (Left_Opnd (N));
7295 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
7296 -- What on earth is this commented out fragment of code???
7298 if Nkind (N) = N_Op_Expon then
7299 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7301 Arg2 := Convert_Operand (Right_Opnd (N));
7304 if Nkind (Arg1) = N_Type_Conversion then
7305 Save_Interps (Left_Opnd (N), Expression (Arg1));
7308 if Nkind (Arg2) = N_Type_Conversion then
7309 Save_Interps (Right_Opnd (N), Expression (Arg2));
7312 Set_Left_Opnd (N, Arg1);
7313 Set_Right_Opnd (N, Arg2);
7315 Set_Etype (N, Btyp);
7316 Rewrite (N, Unchecked_Convert_To (Typ, N));
7319 elsif Typ /= Etype (Left_Opnd (N))
7320 or else Typ /= Etype (Right_Opnd (N))
7322 -- Add explicit conversion where needed, and save interpretations in
7323 -- case operands are overloaded. If the context is a VMS operation,
7324 -- assert that the conversion is legal (the operands have the proper
7325 -- types to select the VMS intrinsic). Note that in rare cases the
7326 -- VMS operators may be visible, but the default System is being used
7327 -- and Address is a private type.
7329 Arg1 := Convert_To (Typ, Left_Opnd (N));
7330 Arg2 := Convert_To (Typ, Right_Opnd (N));
7332 if Nkind (Arg1) = N_Type_Conversion then
7333 Save_Interps (Left_Opnd (N), Expression (Arg1));
7335 if Is_VMS_Operator (Orig_Op) then
7336 Set_Conversion_OK (Arg1);
7339 Save_Interps (Left_Opnd (N), Arg1);
7342 if Nkind (Arg2) = N_Type_Conversion then
7343 Save_Interps (Right_Opnd (N), Expression (Arg2));
7345 if Is_VMS_Operator (Orig_Op) then
7346 Set_Conversion_OK (Arg2);
7349 Save_Interps (Right_Opnd (N), Arg2);
7352 Rewrite (Left_Opnd (N), Arg1);
7353 Rewrite (Right_Opnd (N), Arg2);
7356 Resolve_Arithmetic_Op (N, Typ);
7359 Resolve_Arithmetic_Op (N, Typ);
7361 end Resolve_Intrinsic_Operator;
7363 --------------------------------------
7364 -- Resolve_Intrinsic_Unary_Operator --
7365 --------------------------------------
7367 procedure Resolve_Intrinsic_Unary_Operator
7371 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7377 while Scope (Op) /= Standard_Standard loop
7379 pragma Assert (Present (Op));
7384 if Is_Private_Type (Typ) then
7385 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7386 Save_Interps (Right_Opnd (N), Expression (Arg2));
7388 Set_Right_Opnd (N, Arg2);
7390 Set_Etype (N, Btyp);
7391 Rewrite (N, Unchecked_Convert_To (Typ, N));
7395 Resolve_Unary_Op (N, Typ);
7397 end Resolve_Intrinsic_Unary_Operator;
7399 ------------------------
7400 -- Resolve_Logical_Op --
7401 ------------------------
7403 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7407 Check_No_Direct_Boolean_Operators (N);
7409 -- Predefined operations on scalar types yield the base type. On the
7410 -- other hand, logical operations on arrays yield the type of the
7411 -- arguments (and the context).
7413 if Is_Array_Type (Typ) then
7416 B_Typ := Base_Type (Typ);
7419 -- OK if this is a VMS-specific intrinsic operation
7421 if Is_VMS_Operator (Entity (N)) then
7424 -- The following test is required because the operands of the operation
7425 -- may be literals, in which case the resulting type appears to be
7426 -- compatible with a signed integer type, when in fact it is compatible
7427 -- only with modular types. If the context itself is universal, the
7428 -- operation is illegal.
7430 elsif not Valid_Boolean_Arg (Typ) then
7431 Error_Msg_N ("invalid context for logical operation", N);
7432 Set_Etype (N, Any_Type);
7435 elsif Typ = Any_Modular then
7437 ("no modular type available in this context", N);
7438 Set_Etype (N, Any_Type);
7441 elsif Is_Modular_Integer_Type (Typ)
7442 and then Etype (Left_Opnd (N)) = Universal_Integer
7443 and then Etype (Right_Opnd (N)) = Universal_Integer
7445 Check_For_Visible_Operator (N, B_Typ);
7448 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
7449 -- is active and the result type is standard Boolean (do not mess with
7450 -- ops that return a nonstandard Boolean type, because something strange
7453 -- Note: you might expect this replacement to be done during expansion,
7454 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
7455 -- is used, no part of the right operand of an "and" or "or" operator
7456 -- should be executed if the left operand would short-circuit the
7457 -- evaluation of the corresponding "and then" or "or else". If we left
7458 -- the replacement to expansion time, then run-time checks associated
7459 -- with such operands would be evaluated unconditionally, due to being
7460 -- before the condition prior to the rewriting as short-circuit forms
7461 -- during expansion.
7463 if Short_Circuit_And_Or
7464 and then B_Typ = Standard_Boolean
7465 and then Nkind_In (N, N_Op_And, N_Op_Or)
7467 if Nkind (N) = N_Op_And then
7469 Make_And_Then (Sloc (N),
7470 Left_Opnd => Relocate_Node (Left_Opnd (N)),
7471 Right_Opnd => Relocate_Node (Right_Opnd (N))));
7472 Analyze_And_Resolve (N, B_Typ);
7474 -- Case of OR changed to OR ELSE
7478 Make_Or_Else (Sloc (N),
7479 Left_Opnd => Relocate_Node (Left_Opnd (N)),
7480 Right_Opnd => Relocate_Node (Right_Opnd (N))));
7481 Analyze_And_Resolve (N, B_Typ);
7484 -- Return now, since analysis of the rewritten ops will take care of
7485 -- other reference bookkeeping and expression folding.
7490 Resolve (Left_Opnd (N), B_Typ);
7491 Resolve (Right_Opnd (N), B_Typ);
7493 Check_Unset_Reference (Left_Opnd (N));
7494 Check_Unset_Reference (Right_Opnd (N));
7496 Set_Etype (N, B_Typ);
7497 Generate_Operator_Reference (N, B_Typ);
7498 Eval_Logical_Op (N);
7500 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
7501 -- only when both operands have same static lower and higher bounds. Of
7502 -- course the types have to match, so only check if operands are
7503 -- compatible and the node itself has no errors.
7505 if Is_Array_Type (B_Typ)
7506 and then Nkind (N) in N_Binary_Op
7509 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
7510 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
7513 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7514 -- operation if not needed.
7516 if Restriction_Check_Required (SPARK)
7517 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
7518 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
7519 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
7520 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
7522 Check_SPARK_Restriction
7523 ("array types should have matching static bounds", N);
7527 end Resolve_Logical_Op;
7529 ---------------------------
7530 -- Resolve_Membership_Op --
7531 ---------------------------
7533 -- The context can only be a boolean type, and does not determine the
7534 -- arguments. Arguments should be unambiguous, but the preference rule for
7535 -- universal types applies.
7537 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
7538 pragma Warnings (Off, Typ);
7540 L : constant Node_Id := Left_Opnd (N);
7541 R : constant Node_Id := Right_Opnd (N);
7544 procedure Resolve_Set_Membership;
7545 -- Analysis has determined a unique type for the left operand. Use it to
7546 -- resolve the disjuncts.
7548 ----------------------------
7549 -- Resolve_Set_Membership --
7550 ----------------------------
7552 procedure Resolve_Set_Membership is
7556 Resolve (L, Etype (L));
7558 Alt := First (Alternatives (N));
7559 while Present (Alt) loop
7561 -- Alternative is an expression, a range
7562 -- or a subtype mark.
7564 if not Is_Entity_Name (Alt)
7565 or else not Is_Type (Entity (Alt))
7567 Resolve (Alt, Etype (L));
7572 end Resolve_Set_Membership;
7574 -- Start of processing for Resolve_Membership_Op
7577 if L = Error or else R = Error then
7581 if Present (Alternatives (N)) then
7582 Resolve_Set_Membership;
7585 elsif not Is_Overloaded (R)
7587 (Etype (R) = Universal_Integer
7589 Etype (R) = Universal_Real)
7590 and then Is_Overloaded (L)
7594 -- Ada 2005 (AI-251): Support the following case:
7596 -- type I is interface;
7597 -- type T is tagged ...
7599 -- function Test (O : I'Class) is
7601 -- return O in T'Class.
7604 -- In this case we have nothing else to do. The membership test will be
7605 -- done at run time.
7607 elsif Ada_Version >= Ada_2005
7608 and then Is_Class_Wide_Type (Etype (L))
7609 and then Is_Interface (Etype (L))
7610 and then Is_Class_Wide_Type (Etype (R))
7611 and then not Is_Interface (Etype (R))
7615 T := Intersect_Types (L, R);
7618 -- If mixed-mode operations are present and operands are all literal,
7619 -- the only interpretation involves Duration, which is probably not
7620 -- the intention of the programmer.
7622 if T = Any_Fixed then
7623 T := Unique_Fixed_Point_Type (N);
7625 if T = Any_Type then
7631 Check_Unset_Reference (L);
7633 if Nkind (R) = N_Range
7634 and then not Is_Scalar_Type (T)
7636 Error_Msg_N ("scalar type required for range", R);
7639 if Is_Entity_Name (R) then
7640 Freeze_Expression (R);
7643 Check_Unset_Reference (R);
7646 Eval_Membership_Op (N);
7647 end Resolve_Membership_Op;
7653 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
7654 Loc : constant Source_Ptr := Sloc (N);
7657 -- Handle restriction against anonymous null access values This
7658 -- restriction can be turned off using -gnatdj.
7660 -- Ada 2005 (AI-231): Remove restriction
7662 if Ada_Version < Ada_2005
7663 and then not Debug_Flag_J
7664 and then Ekind (Typ) = E_Anonymous_Access_Type
7665 and then Comes_From_Source (N)
7667 -- In the common case of a call which uses an explicitly null value
7668 -- for an access parameter, give specialized error message.
7670 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
7674 ("null is not allowed as argument for an access parameter", N);
7676 -- Standard message for all other cases (are there any?)
7680 ("null cannot be of an anonymous access type", N);
7684 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7685 -- assignment to a null-excluding object
7687 if Ada_Version >= Ada_2005
7688 and then Can_Never_Be_Null (Typ)
7689 and then Nkind (Parent (N)) = N_Assignment_Statement
7691 if not Inside_Init_Proc then
7693 (Compile_Time_Constraint_Error (N,
7694 "(Ada 2005) null not allowed in null-excluding objects?"),
7695 Make_Raise_Constraint_Error (Loc,
7696 Reason => CE_Access_Check_Failed));
7699 Make_Raise_Constraint_Error (Loc,
7700 Reason => CE_Access_Check_Failed));
7704 -- In a distributed context, null for a remote access to subprogram may
7705 -- need to be replaced with a special record aggregate. In this case,
7706 -- return after having done the transformation.
7708 if (Ekind (Typ) = E_Record_Type
7709 or else Is_Remote_Access_To_Subprogram_Type (Typ))
7710 and then Remote_AST_Null_Value (N, Typ)
7715 -- The null literal takes its type from the context
7720 -----------------------
7721 -- Resolve_Op_Concat --
7722 -----------------------
7724 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
7726 -- We wish to avoid deep recursion, because concatenations are often
7727 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
7728 -- operands nonrecursively until we find something that is not a simple
7729 -- concatenation (A in this case). We resolve that, and then walk back
7730 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
7731 -- to do the rest of the work at each level. The Parent pointers allow
7732 -- us to avoid recursion, and thus avoid running out of memory. See also
7733 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
7739 -- The following code is equivalent to:
7741 -- Resolve_Op_Concat_First (NN, Typ);
7742 -- Resolve_Op_Concat_Arg (N, ...);
7743 -- Resolve_Op_Concat_Rest (N, Typ);
7745 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
7746 -- operand is a concatenation.
7748 -- Walk down left operands
7751 Resolve_Op_Concat_First (NN, Typ);
7752 Op1 := Left_Opnd (NN);
7753 exit when not (Nkind (Op1) = N_Op_Concat
7754 and then not Is_Array_Type (Component_Type (Typ))
7755 and then Entity (Op1) = Entity (NN));
7759 -- Now (given the above example) NN is A&B and Op1 is A
7761 -- First resolve Op1 ...
7763 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
7765 -- ... then walk NN back up until we reach N (where we started), calling
7766 -- Resolve_Op_Concat_Rest along the way.
7769 Resolve_Op_Concat_Rest (NN, Typ);
7774 if Base_Type (Etype (N)) /= Standard_String then
7775 Check_SPARK_Restriction
7776 ("result of concatenation should have type String", N);
7778 end Resolve_Op_Concat;
7780 ---------------------------
7781 -- Resolve_Op_Concat_Arg --
7782 ---------------------------
7784 procedure Resolve_Op_Concat_Arg
7790 Btyp : constant Entity_Id := Base_Type (Typ);
7791 Ctyp : constant Entity_Id := Component_Type (Typ);
7796 or else (not Is_Overloaded (Arg)
7797 and then Etype (Arg) /= Any_Composite
7798 and then Covers (Ctyp, Etype (Arg)))
7800 Resolve (Arg, Ctyp);
7802 Resolve (Arg, Btyp);
7805 -- If both Array & Array and Array & Component are visible, there is a
7806 -- potential ambiguity that must be reported.
7808 elsif Has_Compatible_Type (Arg, Ctyp) then
7809 if Nkind (Arg) = N_Aggregate
7810 and then Is_Composite_Type (Ctyp)
7812 if Is_Private_Type (Ctyp) then
7813 Resolve (Arg, Btyp);
7815 -- If the operation is user-defined and not overloaded use its
7816 -- profile. The operation may be a renaming, in which case it has
7817 -- been rewritten, and we want the original profile.
7819 elsif not Is_Overloaded (N)
7820 and then Comes_From_Source (Entity (Original_Node (N)))
7821 and then Ekind (Entity (Original_Node (N))) = E_Function
7825 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
7828 -- Otherwise an aggregate may match both the array type and the
7832 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7833 Set_Etype (Arg, Any_Type);
7837 if Is_Overloaded (Arg)
7838 and then Has_Compatible_Type (Arg, Typ)
7839 and then Etype (Arg) /= Any_Type
7847 Get_First_Interp (Arg, I, It);
7849 Get_Next_Interp (I, It);
7851 -- Special-case the error message when the overloading is
7852 -- caused by a function that yields an array and can be
7853 -- called without parameters.
7855 if It.Nam = Func then
7856 Error_Msg_Sloc := Sloc (Func);
7857 Error_Msg_N ("ambiguous call to function#", Arg);
7859 ("\\interpretation as call yields&", Arg, Typ);
7861 ("\\interpretation as indexing of call yields&",
7862 Arg, Component_Type (Typ));
7865 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
7867 Get_First_Interp (Arg, I, It);
7868 while Present (It.Nam) loop
7869 Error_Msg_Sloc := Sloc (It.Nam);
7871 if Base_Type (It.Typ) = Btyp
7873 Base_Type (It.Typ) = Base_Type (Ctyp)
7875 Error_Msg_N -- CODEFIX
7876 ("\\possible interpretation#", Arg);
7879 Get_Next_Interp (I, It);
7885 Resolve (Arg, Component_Type (Typ));
7887 if Nkind (Arg) = N_String_Literal then
7888 Set_Etype (Arg, Component_Type (Typ));
7891 if Arg = Left_Opnd (N) then
7892 Set_Is_Component_Left_Opnd (N);
7894 Set_Is_Component_Right_Opnd (N);
7899 Resolve (Arg, Btyp);
7902 -- Concatenation is restricted in SPARK: each operand must be either a
7903 -- string literal, the name of a string constant, a static character or
7904 -- string expression, or another concatenation. Arg cannot be a
7905 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
7906 -- separately on each final operand, past concatenation operations.
7908 if Is_Character_Type (Etype (Arg)) then
7909 if not Is_Static_Expression (Arg) then
7910 Check_SPARK_Restriction
7911 ("character operand for concatenation should be static", Arg);
7914 elsif Is_String_Type (Etype (Arg)) then
7915 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
7916 and then Is_Constant_Object (Entity (Arg)))
7917 and then not Is_Static_Expression (Arg)
7919 Check_SPARK_Restriction
7920 ("string operand for concatenation should be static", Arg);
7923 -- Do not issue error on an operand that is neither a character nor a
7924 -- string, as the error is issued in Resolve_Op_Concat.
7930 Check_Unset_Reference (Arg);
7931 end Resolve_Op_Concat_Arg;
7933 -----------------------------
7934 -- Resolve_Op_Concat_First --
7935 -----------------------------
7937 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7938 Btyp : constant Entity_Id := Base_Type (Typ);
7939 Op1 : constant Node_Id := Left_Opnd (N);
7940 Op2 : constant Node_Id := Right_Opnd (N);
7943 -- The parser folds an enormous sequence of concatenations of string
7944 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7945 -- in the right operand. If the expression resolves to a predefined "&"
7946 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7947 -- we give an error. See P_Simple_Expression in Par.Ch4.
7949 if Nkind (Op2) = N_String_Literal
7950 and then Is_Folded_In_Parser (Op2)
7951 and then Ekind (Entity (N)) = E_Function
7953 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7954 and then String_Length (Strval (Op1)) = 0);
7955 Error_Msg_N ("too many user-defined concatenations", N);
7959 Set_Etype (N, Btyp);
7961 if Is_Limited_Composite (Btyp) then
7962 Error_Msg_N ("concatenation not available for limited array", N);
7963 Explain_Limited_Type (Btyp, N);
7965 end Resolve_Op_Concat_First;
7967 ----------------------------
7968 -- Resolve_Op_Concat_Rest --
7969 ----------------------------
7971 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7972 Op1 : constant Node_Id := Left_Opnd (N);
7973 Op2 : constant Node_Id := Right_Opnd (N);
7976 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7978 Generate_Operator_Reference (N, Typ);
7980 if Is_String_Type (Typ) then
7981 Eval_Concatenation (N);
7984 -- If this is not a static concatenation, but the result is a string
7985 -- type (and not an array of strings) ensure that static string operands
7986 -- have their subtypes properly constructed.
7988 if Nkind (N) /= N_String_Literal
7989 and then Is_Character_Type (Component_Type (Typ))
7991 Set_String_Literal_Subtype (Op1, Typ);
7992 Set_String_Literal_Subtype (Op2, Typ);
7994 end Resolve_Op_Concat_Rest;
7996 ----------------------
7997 -- Resolve_Op_Expon --
7998 ----------------------
8000 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
8001 B_Typ : constant Entity_Id := Base_Type (Typ);
8004 -- Catch attempts to do fixed-point exponentiation with universal
8005 -- operands, which is a case where the illegality is not caught during
8006 -- normal operator analysis.
8008 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
8009 Error_Msg_N ("exponentiation not available for fixed point", N);
8012 elsif Nkind (Parent (N)) in N_Op
8013 and then Is_Fixed_Point_Type (Etype (Parent (N)))
8014 and then Etype (N) = Universal_Real
8015 and then Comes_From_Source (N)
8017 Error_Msg_N ("exponentiation not available for fixed point", N);
8021 if Comes_From_Source (N)
8022 and then Ekind (Entity (N)) = E_Function
8023 and then Is_Imported (Entity (N))
8024 and then Is_Intrinsic_Subprogram (Entity (N))
8026 Resolve_Intrinsic_Operator (N, Typ);
8030 if Etype (Left_Opnd (N)) = Universal_Integer
8031 or else Etype (Left_Opnd (N)) = Universal_Real
8033 Check_For_Visible_Operator (N, B_Typ);
8036 -- We do the resolution using the base type, because intermediate values
8037 -- in expressions always are of the base type, not a subtype of it.
8039 Resolve (Left_Opnd (N), B_Typ);
8040 Resolve (Right_Opnd (N), Standard_Integer);
8042 Check_Unset_Reference (Left_Opnd (N));
8043 Check_Unset_Reference (Right_Opnd (N));
8045 Set_Etype (N, B_Typ);
8046 Generate_Operator_Reference (N, B_Typ);
8048 Analyze_Dimension (N);
8050 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
8051 -- Evaluate the exponentiation operator for dimensioned type
8053 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
8058 -- Set overflow checking bit. Much cleverer code needed here eventually
8059 -- and perhaps the Resolve routines should be separated for the various
8060 -- arithmetic operations, since they will need different processing. ???
8062 if Nkind (N) in N_Op then
8063 if not Overflow_Checks_Suppressed (Etype (N)) then
8064 Enable_Overflow_Check (N);
8067 end Resolve_Op_Expon;
8069 --------------------
8070 -- Resolve_Op_Not --
8071 --------------------
8073 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
8076 function Parent_Is_Boolean return Boolean;
8077 -- This function determines if the parent node is a boolean operator or
8078 -- operation (comparison op, membership test, or short circuit form) and
8079 -- the not in question is the left operand of this operation. Note that
8080 -- if the not is in parens, then false is returned.
8082 -----------------------
8083 -- Parent_Is_Boolean --
8084 -----------------------
8086 function Parent_Is_Boolean return Boolean is
8088 if Paren_Count (N) /= 0 then
8092 case Nkind (Parent (N)) is
8107 return Left_Opnd (Parent (N)) = N;
8113 end Parent_Is_Boolean;
8115 -- Start of processing for Resolve_Op_Not
8118 -- Predefined operations on scalar types yield the base type. On the
8119 -- other hand, logical operations on arrays yield the type of the
8120 -- arguments (and the context).
8122 if Is_Array_Type (Typ) then
8125 B_Typ := Base_Type (Typ);
8128 if Is_VMS_Operator (Entity (N)) then
8131 -- Straightforward case of incorrect arguments
8133 elsif not Valid_Boolean_Arg (Typ) then
8134 Error_Msg_N ("invalid operand type for operator&", N);
8135 Set_Etype (N, Any_Type);
8138 -- Special case of probable missing parens
8140 elsif Typ = Universal_Integer or else Typ = Any_Modular then
8141 if Parent_Is_Boolean then
8143 ("operand of not must be enclosed in parentheses",
8147 ("no modular type available in this context", N);
8150 Set_Etype (N, Any_Type);
8153 -- OK resolution of NOT
8156 -- Warn if non-boolean types involved. This is a case like not a < b
8157 -- where a and b are modular, where we will get (not a) < b and most
8158 -- likely not (a < b) was intended.
8160 if Warn_On_Questionable_Missing_Parens
8161 and then not Is_Boolean_Type (Typ)
8162 and then Parent_Is_Boolean
8164 Error_Msg_N ("?not expression should be parenthesized here!", N);
8167 -- Warn on double negation if checking redundant constructs
8169 if Warn_On_Redundant_Constructs
8170 and then Comes_From_Source (N)
8171 and then Comes_From_Source (Right_Opnd (N))
8172 and then Root_Type (Typ) = Standard_Boolean
8173 and then Nkind (Right_Opnd (N)) = N_Op_Not
8175 Error_Msg_N ("redundant double negation?", N);
8178 -- Complete resolution and evaluation of NOT
8180 Resolve (Right_Opnd (N), B_Typ);
8181 Check_Unset_Reference (Right_Opnd (N));
8182 Set_Etype (N, B_Typ);
8183 Generate_Operator_Reference (N, B_Typ);
8188 -----------------------------
8189 -- Resolve_Operator_Symbol --
8190 -----------------------------
8192 -- Nothing to be done, all resolved already
8194 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
8195 pragma Warnings (Off, N);
8196 pragma Warnings (Off, Typ);
8200 end Resolve_Operator_Symbol;
8202 ----------------------------------
8203 -- Resolve_Qualified_Expression --
8204 ----------------------------------
8206 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
8207 pragma Warnings (Off, Typ);
8209 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
8210 Expr : constant Node_Id := Expression (N);
8213 Resolve (Expr, Target_Typ);
8215 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8216 -- operation if not needed.
8218 if Restriction_Check_Required (SPARK)
8219 and then Is_Array_Type (Target_Typ)
8220 and then Is_Array_Type (Etype (Expr))
8221 and then Etype (Expr) /= Any_Composite -- or else Expr in error
8222 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
8224 Check_SPARK_Restriction
8225 ("array types should have matching static bounds", N);
8228 -- A qualified expression requires an exact match of the type, class-
8229 -- wide matching is not allowed. However, if the qualifying type is
8230 -- specific and the expression has a class-wide type, it may still be
8231 -- okay, since it can be the result of the expansion of a call to a
8232 -- dispatching function, so we also have to check class-wideness of the
8233 -- type of the expression's original node.
8235 if (Is_Class_Wide_Type (Target_Typ)
8237 (Is_Class_Wide_Type (Etype (Expr))
8238 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
8239 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
8241 Wrong_Type (Expr, Target_Typ);
8244 -- If the target type is unconstrained, then we reset the type of the
8245 -- result from the type of the expression. For other cases, the actual
8246 -- subtype of the expression is the target type.
8248 if Is_Composite_Type (Target_Typ)
8249 and then not Is_Constrained (Target_Typ)
8251 Set_Etype (N, Etype (Expr));
8254 Analyze_Dimension (N);
8255 Eval_Qualified_Expression (N);
8256 end Resolve_Qualified_Expression;
8258 -----------------------------------
8259 -- Resolve_Quantified_Expression --
8260 -----------------------------------
8262 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id) is
8264 if not Alfa_Mode then
8266 -- If expansion is enabled, analysis is delayed until the expresssion
8267 -- is rewritten as a loop.
8269 if Operating_Mode /= Check_Semantics then
8273 -- The loop structure is already resolved during its analysis, only
8274 -- the resolution of the condition needs to be done. Expansion is
8275 -- disabled so that checks and other generated code are inserted in
8276 -- the tree after expression has been rewritten as a loop.
8278 Expander_Mode_Save_And_Set (False);
8279 Resolve (Condition (N), Typ);
8280 Expander_Mode_Restore;
8282 -- In Alfa mode, we need normal expansion in order to properly introduce
8283 -- the necessary transient scopes.
8286 Resolve (Condition (N), Typ);
8288 end Resolve_Quantified_Expression;
8294 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
8295 L : constant Node_Id := Low_Bound (N);
8296 H : constant Node_Id := High_Bound (N);
8298 function First_Last_Ref return Boolean;
8299 -- Returns True if N is of the form X'First .. X'Last where X is the
8300 -- same entity for both attributes.
8302 --------------------
8303 -- First_Last_Ref --
8304 --------------------
8306 function First_Last_Ref return Boolean is
8307 Lorig : constant Node_Id := Original_Node (L);
8308 Horig : constant Node_Id := Original_Node (H);
8311 if Nkind (Lorig) = N_Attribute_Reference
8312 and then Nkind (Horig) = N_Attribute_Reference
8313 and then Attribute_Name (Lorig) = Name_First
8314 and then Attribute_Name (Horig) = Name_Last
8317 PL : constant Node_Id := Prefix (Lorig);
8318 PH : constant Node_Id := Prefix (Horig);
8320 if Is_Entity_Name (PL)
8321 and then Is_Entity_Name (PH)
8322 and then Entity (PL) = Entity (PH)
8332 -- Start of processing for Resolve_Range
8339 -- Check for inappropriate range on unordered enumeration type
8341 if Bad_Unordered_Enumeration_Reference (N, Typ)
8343 -- Exclude X'First .. X'Last if X is the same entity for both
8345 and then not First_Last_Ref
8347 Error_Msg ("subrange of unordered enumeration type?", Sloc (N));
8350 Check_Unset_Reference (L);
8351 Check_Unset_Reference (H);
8353 -- We have to check the bounds for being within the base range as
8354 -- required for a non-static context. Normally this is automatic and
8355 -- done as part of evaluating expressions, but the N_Range node is an
8356 -- exception, since in GNAT we consider this node to be a subexpression,
8357 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8358 -- this, but that would put the test on the main evaluation path for
8361 Check_Non_Static_Context (L);
8362 Check_Non_Static_Context (H);
8364 -- Check for an ambiguous range over character literals. This will
8365 -- happen with a membership test involving only literals.
8367 if Typ = Any_Character then
8368 Ambiguous_Character (L);
8369 Set_Etype (N, Any_Type);
8373 -- If bounds are static, constant-fold them, so size computations are
8374 -- identical between front-end and back-end. Do not perform this
8375 -- transformation while analyzing generic units, as type information
8376 -- would be lost when reanalyzing the constant node in the instance.
8378 if Is_Discrete_Type (Typ) and then Full_Expander_Active then
8379 if Is_OK_Static_Expression (L) then
8380 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8383 if Is_OK_Static_Expression (H) then
8384 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8389 --------------------------
8390 -- Resolve_Real_Literal --
8391 --------------------------
8393 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8394 Actual_Typ : constant Entity_Id := Etype (N);
8397 -- Special processing for fixed-point literals to make sure that the
8398 -- value is an exact multiple of small where this is required. We skip
8399 -- this for the universal real case, and also for generic types.
8401 if Is_Fixed_Point_Type (Typ)
8402 and then Typ /= Universal_Fixed
8403 and then Typ /= Any_Fixed
8404 and then not Is_Generic_Type (Typ)
8407 Val : constant Ureal := Realval (N);
8408 Cintr : constant Ureal := Val / Small_Value (Typ);
8409 Cint : constant Uint := UR_Trunc (Cintr);
8410 Den : constant Uint := Norm_Den (Cintr);
8414 -- Case of literal is not an exact multiple of the Small
8418 -- For a source program literal for a decimal fixed-point type,
8419 -- this is statically illegal (RM 4.9(36)).
8421 if Is_Decimal_Fixed_Point_Type (Typ)
8422 and then Actual_Typ = Universal_Real
8423 and then Comes_From_Source (N)
8425 Error_Msg_N ("value has extraneous low order digits", N);
8428 -- Generate a warning if literal from source
8430 if Is_Static_Expression (N)
8431 and then Warn_On_Bad_Fixed_Value
8434 ("?static fixed-point value is not a multiple of Small!",
8438 -- Replace literal by a value that is the exact representation
8439 -- of a value of the type, i.e. a multiple of the small value,
8440 -- by truncation, since Machine_Rounds is false for all GNAT
8441 -- fixed-point types (RM 4.9(38)).
8443 Stat := Is_Static_Expression (N);
8445 Make_Real_Literal (Sloc (N),
8446 Realval => Small_Value (Typ) * Cint));
8448 Set_Is_Static_Expression (N, Stat);
8451 -- In all cases, set the corresponding integer field
8453 Set_Corresponding_Integer_Value (N, Cint);
8457 -- Now replace the actual type by the expected type as usual
8460 Eval_Real_Literal (N);
8461 end Resolve_Real_Literal;
8463 -----------------------
8464 -- Resolve_Reference --
8465 -----------------------
8467 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
8468 P : constant Node_Id := Prefix (N);
8471 -- Replace general access with specific type
8473 if Ekind (Etype (N)) = E_Allocator_Type then
8474 Set_Etype (N, Base_Type (Typ));
8477 Resolve (P, Designated_Type (Etype (N)));
8479 -- If we are taking the reference of a volatile entity, then treat it as
8480 -- a potential modification of this entity. This is too conservative,
8481 -- but necessary because remove side effects can cause transformations
8482 -- of normal assignments into reference sequences that otherwise fail to
8483 -- notice the modification.
8485 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
8486 Note_Possible_Modification (P, Sure => False);
8488 end Resolve_Reference;
8490 --------------------------------
8491 -- Resolve_Selected_Component --
8492 --------------------------------
8494 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
8496 Comp1 : Entity_Id := Empty; -- prevent junk warning
8497 P : constant Node_Id := Prefix (N);
8498 S : constant Node_Id := Selector_Name (N);
8499 T : Entity_Id := Etype (P);
8501 I1 : Interp_Index := 0; -- prevent junk warning
8506 function Init_Component return Boolean;
8507 -- Check whether this is the initialization of a component within an
8508 -- init proc (by assignment or call to another init proc). If true,
8509 -- there is no need for a discriminant check.
8511 --------------------
8512 -- Init_Component --
8513 --------------------
8515 function Init_Component return Boolean is
8517 return Inside_Init_Proc
8518 and then Nkind (Prefix (N)) = N_Identifier
8519 and then Chars (Prefix (N)) = Name_uInit
8520 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
8523 -- Start of processing for Resolve_Selected_Component
8526 if Is_Overloaded (P) then
8528 -- Use the context type to select the prefix that has a selector
8529 -- of the correct name and type.
8532 Get_First_Interp (P, I, It);
8534 Search : while Present (It.Typ) loop
8535 if Is_Access_Type (It.Typ) then
8536 T := Designated_Type (It.Typ);
8541 -- Locate selected component. For a private prefix the selector
8542 -- can denote a discriminant.
8544 if Is_Record_Type (T) or else Is_Private_Type (T) then
8546 -- The visible components of a class-wide type are those of
8549 if Is_Class_Wide_Type (T) then
8553 Comp := First_Entity (T);
8554 while Present (Comp) loop
8555 if Chars (Comp) = Chars (S)
8556 and then Covers (Etype (Comp), Typ)
8565 It := Disambiguate (P, I1, I, Any_Type);
8567 if It = No_Interp then
8569 ("ambiguous prefix for selected component", N);
8576 -- There may be an implicit dereference. Retrieve
8577 -- designated record type.
8579 if Is_Access_Type (It1.Typ) then
8580 T := Designated_Type (It1.Typ);
8585 if Scope (Comp1) /= T then
8587 -- Resolution chooses the new interpretation.
8588 -- Find the component with the right name.
8590 Comp1 := First_Entity (T);
8591 while Present (Comp1)
8592 and then Chars (Comp1) /= Chars (S)
8594 Comp1 := Next_Entity (Comp1);
8603 Comp := Next_Entity (Comp);
8607 Get_Next_Interp (I, It);
8610 Resolve (P, It1.Typ);
8612 Set_Entity_With_Style_Check (S, Comp1);
8615 -- Resolve prefix with its type
8620 -- Generate cross-reference. We needed to wait until full overloading
8621 -- resolution was complete to do this, since otherwise we can't tell if
8622 -- we are an lvalue or not.
8624 if May_Be_Lvalue (N) then
8625 Generate_Reference (Entity (S), S, 'm');
8627 Generate_Reference (Entity (S), S, 'r');
8630 -- If prefix is an access type, the node will be transformed into an
8631 -- explicit dereference during expansion. The type of the node is the
8632 -- designated type of that of the prefix.
8634 if Is_Access_Type (Etype (P)) then
8635 T := Designated_Type (Etype (P));
8636 Check_Fully_Declared_Prefix (T, P);
8641 if Has_Discriminants (T)
8642 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
8643 and then Present (Original_Record_Component (Entity (S)))
8644 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
8645 and then Present (Discriminant_Checking_Func
8646 (Original_Record_Component (Entity (S))))
8647 and then not Discriminant_Checks_Suppressed (T)
8648 and then not Init_Component
8650 Set_Do_Discriminant_Check (N);
8653 if Ekind (Entity (S)) = E_Void then
8654 Error_Msg_N ("premature use of component", S);
8657 -- If the prefix is a record conversion, this may be a renamed
8658 -- discriminant whose bounds differ from those of the original
8659 -- one, so we must ensure that a range check is performed.
8661 if Nkind (P) = N_Type_Conversion
8662 and then Ekind (Entity (S)) = E_Discriminant
8663 and then Is_Discrete_Type (Typ)
8665 Set_Etype (N, Base_Type (Typ));
8668 -- Note: No Eval processing is required, because the prefix is of a
8669 -- record type, or protected type, and neither can possibly be static.
8671 -- If the array type is atomic, and is packed, and we are in a left side
8672 -- context, then this is worth a warning, since we have a situation
8673 -- where the access to the component may cause extra read/writes of the
8674 -- atomic array object, which could be considered unexpected.
8676 if Nkind (N) = N_Selected_Component
8677 and then (Is_Atomic (T)
8678 or else (Is_Entity_Name (Prefix (N))
8679 and then Is_Atomic (Entity (Prefix (N)))))
8680 and then Is_Packed (T)
8684 ("?assignment to component of packed atomic record", Prefix (N));
8686 ("?\may cause unexpected accesses to atomic object", Prefix (N));
8689 Analyze_Dimension (N);
8690 end Resolve_Selected_Component;
8696 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
8697 B_Typ : constant Entity_Id := Base_Type (Typ);
8698 L : constant Node_Id := Left_Opnd (N);
8699 R : constant Node_Id := Right_Opnd (N);
8702 -- We do the resolution using the base type, because intermediate values
8703 -- in expressions always are of the base type, not a subtype of it.
8706 Resolve (R, Standard_Natural);
8708 Check_Unset_Reference (L);
8709 Check_Unset_Reference (R);
8711 Set_Etype (N, B_Typ);
8712 Generate_Operator_Reference (N, B_Typ);
8716 ---------------------------
8717 -- Resolve_Short_Circuit --
8718 ---------------------------
8720 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
8721 B_Typ : constant Entity_Id := Base_Type (Typ);
8722 L : constant Node_Id := Left_Opnd (N);
8723 R : constant Node_Id := Right_Opnd (N);
8729 -- Check for issuing warning for always False assert/check, this happens
8730 -- when assertions are turned off, in which case the pragma Assert/Check
8731 -- was transformed into:
8733 -- if False and then <condition> then ...
8735 -- and we detect this pattern
8737 if Warn_On_Assertion_Failure
8738 and then Is_Entity_Name (R)
8739 and then Entity (R) = Standard_False
8740 and then Nkind (Parent (N)) = N_If_Statement
8741 and then Nkind (N) = N_And_Then
8742 and then Is_Entity_Name (L)
8743 and then Entity (L) = Standard_False
8746 Orig : constant Node_Id := Original_Node (Parent (N));
8749 if Nkind (Orig) = N_Pragma
8750 and then Pragma_Name (Orig) = Name_Assert
8752 -- Don't want to warn if original condition is explicit False
8755 Expr : constant Node_Id :=
8758 (First (Pragma_Argument_Associations (Orig))));
8760 if Is_Entity_Name (Expr)
8761 and then Entity (Expr) = Standard_False
8765 -- Issue warning. We do not want the deletion of the
8766 -- IF/AND-THEN to take this message with it. We achieve
8767 -- this by making sure that the expanded code points to
8768 -- the Sloc of the expression, not the original pragma.
8770 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
8771 -- The source location of the expression is not usually
8772 -- the best choice here. For example, it gets located on
8773 -- the last AND keyword in a chain of boolean expressiond
8774 -- AND'ed together. It is best to put the message on the
8775 -- first character of the assertion, which is the effect
8776 -- of the First_Node call here.
8779 ("?assertion would fail at run time!",
8781 (First (Pragma_Argument_Associations (Orig))));
8785 -- Similar processing for Check pragma
8787 elsif Nkind (Orig) = N_Pragma
8788 and then Pragma_Name (Orig) = Name_Check
8790 -- Don't want to warn if original condition is explicit False
8793 Expr : constant Node_Id :=
8797 (Pragma_Argument_Associations (Orig)))));
8799 if Is_Entity_Name (Expr)
8800 and then Entity (Expr) = Standard_False
8807 -- Again use Error_Msg_F rather than Error_Msg_N, see
8808 -- comment above for an explanation of why we do this.
8811 ("?check would fail at run time!",
8813 (Last (Pragma_Argument_Associations (Orig))));
8820 -- Continue with processing of short circuit
8822 Check_Unset_Reference (L);
8823 Check_Unset_Reference (R);
8825 Set_Etype (N, B_Typ);
8826 Eval_Short_Circuit (N);
8827 end Resolve_Short_Circuit;
8833 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
8834 Name : constant Node_Id := Prefix (N);
8835 Drange : constant Node_Id := Discrete_Range (N);
8836 Array_Type : Entity_Id := Empty;
8840 if Is_Overloaded (Name) then
8842 -- Use the context type to select the prefix that yields the correct
8847 I1 : Interp_Index := 0;
8849 P : constant Node_Id := Prefix (N);
8850 Found : Boolean := False;
8853 Get_First_Interp (P, I, It);
8854 while Present (It.Typ) loop
8855 if (Is_Array_Type (It.Typ)
8856 and then Covers (Typ, It.Typ))
8857 or else (Is_Access_Type (It.Typ)
8858 and then Is_Array_Type (Designated_Type (It.Typ))
8859 and then Covers (Typ, Designated_Type (It.Typ)))
8862 It := Disambiguate (P, I1, I, Any_Type);
8864 if It = No_Interp then
8865 Error_Msg_N ("ambiguous prefix for slicing", N);
8870 Array_Type := It.Typ;
8875 Array_Type := It.Typ;
8880 Get_Next_Interp (I, It);
8885 Array_Type := Etype (Name);
8888 Resolve (Name, Array_Type);
8890 if Is_Access_Type (Array_Type) then
8891 Apply_Access_Check (N);
8892 Array_Type := Designated_Type (Array_Type);
8894 -- If the prefix is an access to an unconstrained array, we must use
8895 -- the actual subtype of the object to perform the index checks. The
8896 -- object denoted by the prefix is implicit in the node, so we build
8897 -- an explicit representation for it in order to compute the actual
8900 if not Is_Constrained (Array_Type) then
8901 Remove_Side_Effects (Prefix (N));
8904 Obj : constant Node_Id :=
8905 Make_Explicit_Dereference (Sloc (N),
8906 Prefix => New_Copy_Tree (Prefix (N)));
8908 Set_Etype (Obj, Array_Type);
8909 Set_Parent (Obj, Parent (N));
8910 Array_Type := Get_Actual_Subtype (Obj);
8914 elsif Is_Entity_Name (Name)
8915 or else Nkind (Name) = N_Explicit_Dereference
8916 or else (Nkind (Name) = N_Function_Call
8917 and then not Is_Constrained (Etype (Name)))
8919 Array_Type := Get_Actual_Subtype (Name);
8921 -- If the name is a selected component that depends on discriminants,
8922 -- build an actual subtype for it. This can happen only when the name
8923 -- itself is overloaded; otherwise the actual subtype is created when
8924 -- the selected component is analyzed.
8926 elsif Nkind (Name) = N_Selected_Component
8927 and then Full_Analysis
8928 and then Depends_On_Discriminant (First_Index (Array_Type))
8931 Act_Decl : constant Node_Id :=
8932 Build_Actual_Subtype_Of_Component (Array_Type, Name);
8934 Insert_Action (N, Act_Decl);
8935 Array_Type := Defining_Identifier (Act_Decl);
8938 -- Maybe this should just be "else", instead of checking for the
8939 -- specific case of slice??? This is needed for the case where the
8940 -- prefix is an Image attribute, which gets expanded to a slice, and so
8941 -- has a constrained subtype which we want to use for the slice range
8942 -- check applied below (the range check won't get done if the
8943 -- unconstrained subtype of the 'Image is used).
8945 elsif Nkind (Name) = N_Slice then
8946 Array_Type := Etype (Name);
8949 -- If name was overloaded, set slice type correctly now
8951 Set_Etype (N, Array_Type);
8953 -- If the range is specified by a subtype mark, no resolution is
8954 -- necessary. Else resolve the bounds, and apply needed checks.
8956 if not Is_Entity_Name (Drange) then
8957 Index := First_Index (Array_Type);
8958 Resolve (Drange, Base_Type (Etype (Index)));
8960 if Nkind (Drange) = N_Range then
8962 -- Ensure that side effects in the bounds are properly handled
8964 Force_Evaluation (Low_Bound (Drange));
8965 Force_Evaluation (High_Bound (Drange));
8967 -- Do not apply the range check to nodes associated with the
8968 -- frontend expansion of the dispatch table. We first check
8969 -- if Ada.Tags is already loaded to avoid the addition of an
8970 -- undesired dependence on such run-time unit.
8972 if not Tagged_Type_Expansion
8974 (RTU_Loaded (Ada_Tags)
8975 and then Nkind (Prefix (N)) = N_Selected_Component
8976 and then Present (Entity (Selector_Name (Prefix (N))))
8977 and then Entity (Selector_Name (Prefix (N))) =
8978 RTE_Record_Component (RE_Prims_Ptr))
8980 Apply_Range_Check (Drange, Etype (Index));
8985 Set_Slice_Subtype (N);
8987 -- Check bad use of type with predicates
8989 if Has_Predicates (Etype (Drange)) then
8990 Bad_Predicated_Subtype_Use
8991 ("subtype& has predicate, not allowed in slice",
8992 Drange, Etype (Drange));
8994 -- Otherwise here is where we check suspicious indexes
8996 elsif Nkind (Drange) = N_Range then
8997 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8998 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
9001 Analyze_Dimension (N);
9005 ----------------------------
9006 -- Resolve_String_Literal --
9007 ----------------------------
9009 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
9010 C_Typ : constant Entity_Id := Component_Type (Typ);
9011 R_Typ : constant Entity_Id := Root_Type (C_Typ);
9012 Loc : constant Source_Ptr := Sloc (N);
9013 Str : constant String_Id := Strval (N);
9014 Strlen : constant Nat := String_Length (Str);
9015 Subtype_Id : Entity_Id;
9016 Need_Check : Boolean;
9019 -- For a string appearing in a concatenation, defer creation of the
9020 -- string_literal_subtype until the end of the resolution of the
9021 -- concatenation, because the literal may be constant-folded away. This
9022 -- is a useful optimization for long concatenation expressions.
9024 -- If the string is an aggregate built for a single character (which
9025 -- happens in a non-static context) or a is null string to which special
9026 -- checks may apply, we build the subtype. Wide strings must also get a
9027 -- string subtype if they come from a one character aggregate. Strings
9028 -- generated by attributes might be static, but it is often hard to
9029 -- determine whether the enclosing context is static, so we generate
9030 -- subtypes for them as well, thus losing some rarer optimizations ???
9031 -- Same for strings that come from a static conversion.
9034 (Strlen = 0 and then Typ /= Standard_String)
9035 or else Nkind (Parent (N)) /= N_Op_Concat
9036 or else (N /= Left_Opnd (Parent (N))
9037 and then N /= Right_Opnd (Parent (N)))
9038 or else ((Typ = Standard_Wide_String
9039 or else Typ = Standard_Wide_Wide_String)
9040 and then Nkind (Original_Node (N)) /= N_String_Literal);
9042 -- If the resolving type is itself a string literal subtype, we can just
9043 -- reuse it, since there is no point in creating another.
9045 if Ekind (Typ) = E_String_Literal_Subtype then
9048 elsif Nkind (Parent (N)) = N_Op_Concat
9049 and then not Need_Check
9050 and then not Nkind_In (Original_Node (N), N_Character_Literal,
9051 N_Attribute_Reference,
9052 N_Qualified_Expression,
9057 -- Otherwise we must create a string literal subtype. Note that the
9058 -- whole idea of string literal subtypes is simply to avoid the need
9059 -- for building a full fledged array subtype for each literal.
9062 Set_String_Literal_Subtype (N, Typ);
9063 Subtype_Id := Etype (N);
9066 if Nkind (Parent (N)) /= N_Op_Concat
9069 Set_Etype (N, Subtype_Id);
9070 Eval_String_Literal (N);
9073 if Is_Limited_Composite (Typ)
9074 or else Is_Private_Composite (Typ)
9076 Error_Msg_N ("string literal not available for private array", N);
9077 Set_Etype (N, Any_Type);
9081 -- The validity of a null string has been checked in the call to
9082 -- Eval_String_Literal.
9087 -- Always accept string literal with component type Any_Character, which
9088 -- occurs in error situations and in comparisons of literals, both of
9089 -- which should accept all literals.
9091 elsif R_Typ = Any_Character then
9094 -- If the type is bit-packed, then we always transform the string
9095 -- literal into a full fledged aggregate.
9097 elsif Is_Bit_Packed_Array (Typ) then
9100 -- Deal with cases of Wide_Wide_String, Wide_String, and String
9103 -- For Standard.Wide_Wide_String, or any other type whose component
9104 -- type is Standard.Wide_Wide_Character, we know that all the
9105 -- characters in the string must be acceptable, since the parser
9106 -- accepted the characters as valid character literals.
9108 if R_Typ = Standard_Wide_Wide_Character then
9111 -- For the case of Standard.String, or any other type whose component
9112 -- type is Standard.Character, we must make sure that there are no
9113 -- wide characters in the string, i.e. that it is entirely composed
9114 -- of characters in range of type Character.
9116 -- If the string literal is the result of a static concatenation, the
9117 -- test has already been performed on the components, and need not be
9120 elsif R_Typ = Standard_Character
9121 and then Nkind (Original_Node (N)) /= N_Op_Concat
9123 for J in 1 .. Strlen loop
9124 if not In_Character_Range (Get_String_Char (Str, J)) then
9126 -- If we are out of range, post error. This is one of the
9127 -- very few places that we place the flag in the middle of
9128 -- a token, right under the offending wide character. Not
9129 -- quite clear if this is right wrt wide character encoding
9130 -- sequences, but it's only an error message!
9133 ("literal out of range of type Standard.Character",
9134 Source_Ptr (Int (Loc) + J));
9139 -- For the case of Standard.Wide_String, or any other type whose
9140 -- component type is Standard.Wide_Character, we must make sure that
9141 -- there are no wide characters in the string, i.e. that it is
9142 -- entirely composed of characters in range of type Wide_Character.
9144 -- If the string literal is the result of a static concatenation,
9145 -- the test has already been performed on the components, and need
9148 elsif R_Typ = Standard_Wide_Character
9149 and then Nkind (Original_Node (N)) /= N_Op_Concat
9151 for J in 1 .. Strlen loop
9152 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
9154 -- If we are out of range, post error. This is one of the
9155 -- very few places that we place the flag in the middle of
9156 -- a token, right under the offending wide character.
9158 -- This is not quite right, because characters in general
9159 -- will take more than one character position ???
9162 ("literal out of range of type Standard.Wide_Character",
9163 Source_Ptr (Int (Loc) + J));
9168 -- If the root type is not a standard character, then we will convert
9169 -- the string into an aggregate and will let the aggregate code do
9170 -- the checking. Standard Wide_Wide_Character is also OK here.
9176 -- See if the component type of the array corresponding to the string
9177 -- has compile time known bounds. If yes we can directly check
9178 -- whether the evaluation of the string will raise constraint error.
9179 -- Otherwise we need to transform the string literal into the
9180 -- corresponding character aggregate and let the aggregate code do
9183 if Is_Standard_Character_Type (R_Typ) then
9185 -- Check for the case of full range, where we are definitely OK
9187 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
9191 -- Here the range is not the complete base type range, so check
9194 Comp_Typ_Lo : constant Node_Id :=
9195 Type_Low_Bound (Component_Type (Typ));
9196 Comp_Typ_Hi : constant Node_Id :=
9197 Type_High_Bound (Component_Type (Typ));
9202 if Compile_Time_Known_Value (Comp_Typ_Lo)
9203 and then Compile_Time_Known_Value (Comp_Typ_Hi)
9205 for J in 1 .. Strlen loop
9206 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
9208 if Char_Val < Expr_Value (Comp_Typ_Lo)
9209 or else Char_Val > Expr_Value (Comp_Typ_Hi)
9211 Apply_Compile_Time_Constraint_Error
9212 (N, "character out of range?", CE_Range_Check_Failed,
9213 Loc => Source_Ptr (Int (Loc) + J));
9223 -- If we got here we meed to transform the string literal into the
9224 -- equivalent qualified positional array aggregate. This is rather
9225 -- heavy artillery for this situation, but it is hard work to avoid.
9228 Lits : constant List_Id := New_List;
9229 P : Source_Ptr := Loc + 1;
9233 -- Build the character literals, we give them source locations that
9234 -- correspond to the string positions, which is a bit tricky given
9235 -- the possible presence of wide character escape sequences.
9237 for J in 1 .. Strlen loop
9238 C := Get_String_Char (Str, J);
9239 Set_Character_Literal_Name (C);
9242 Make_Character_Literal (P,
9244 Char_Literal_Value => UI_From_CC (C)));
9246 if In_Character_Range (C) then
9249 -- Should we have a call to Skip_Wide here ???
9258 Make_Qualified_Expression (Loc,
9259 Subtype_Mark => New_Reference_To (Typ, Loc),
9261 Make_Aggregate (Loc, Expressions => Lits)));
9263 Analyze_And_Resolve (N, Typ);
9265 end Resolve_String_Literal;
9267 -----------------------------
9268 -- Resolve_Subprogram_Info --
9269 -----------------------------
9271 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
9274 end Resolve_Subprogram_Info;
9276 -----------------------------
9277 -- Resolve_Type_Conversion --
9278 -----------------------------
9280 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
9281 Conv_OK : constant Boolean := Conversion_OK (N);
9282 Operand : constant Node_Id := Expression (N);
9283 Operand_Typ : constant Entity_Id := Etype (Operand);
9284 Target_Typ : constant Entity_Id := Etype (N);
9289 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
9290 -- Set to False to suppress cases where we want to suppress the test
9291 -- for redundancy to avoid possible false positives on this warning.
9295 and then not Valid_Conversion (N, Target_Typ, Operand)
9300 -- If the Operand Etype is Universal_Fixed, then the conversion is
9301 -- never redundant. We need this check because by the time we have
9302 -- finished the rather complex transformation, the conversion looks
9303 -- redundant when it is not.
9305 if Operand_Typ = Universal_Fixed then
9306 Test_Redundant := False;
9308 -- If the operand is marked as Any_Fixed, then special processing is
9309 -- required. This is also a case where we suppress the test for a
9310 -- redundant conversion, since most certainly it is not redundant.
9312 elsif Operand_Typ = Any_Fixed then
9313 Test_Redundant := False;
9315 -- Mixed-mode operation involving a literal. Context must be a fixed
9316 -- type which is applied to the literal subsequently.
9318 if Is_Fixed_Point_Type (Typ) then
9319 Set_Etype (Operand, Universal_Real);
9321 elsif Is_Numeric_Type (Typ)
9322 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
9323 and then (Etype (Right_Opnd (Operand)) = Universal_Real
9325 Etype (Left_Opnd (Operand)) = Universal_Real)
9327 -- Return if expression is ambiguous
9329 if Unique_Fixed_Point_Type (N) = Any_Type then
9332 -- If nothing else, the available fixed type is Duration
9335 Set_Etype (Operand, Standard_Duration);
9338 -- Resolve the real operand with largest available precision
9340 if Etype (Right_Opnd (Operand)) = Universal_Real then
9341 Rop := New_Copy_Tree (Right_Opnd (Operand));
9343 Rop := New_Copy_Tree (Left_Opnd (Operand));
9346 Resolve (Rop, Universal_Real);
9348 -- If the operand is a literal (it could be a non-static and
9349 -- illegal exponentiation) check whether the use of Duration
9350 -- is potentially inaccurate.
9352 if Nkind (Rop) = N_Real_Literal
9353 and then Realval (Rop) /= Ureal_0
9354 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9357 ("?universal real operand can only " &
9358 "be interpreted as Duration!",
9361 ("\?precision will be lost in the conversion!", Rop);
9364 elsif Is_Numeric_Type (Typ)
9365 and then Nkind (Operand) in N_Op
9366 and then Unique_Fixed_Point_Type (N) /= Any_Type
9368 Set_Etype (Operand, Standard_Duration);
9371 Error_Msg_N ("invalid context for mixed mode operation", N);
9372 Set_Etype (Operand, Any_Type);
9379 -- In SPARK, a type conversion between array types should be restricted
9380 -- to types which have matching static bounds.
9382 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9383 -- operation if not needed.
9385 if Restriction_Check_Required (SPARK)
9386 and then Is_Array_Type (Target_Typ)
9387 and then Is_Array_Type (Operand_Typ)
9388 and then Operand_Typ /= Any_Composite -- or else Operand in error
9389 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
9391 Check_SPARK_Restriction
9392 ("array types should have matching static bounds", N);
9395 -- In formal mode, the operand of an ancestor type conversion must be an
9396 -- object (not an expression).
9398 if Is_Tagged_Type (Target_Typ)
9399 and then not Is_Class_Wide_Type (Target_Typ)
9400 and then Is_Tagged_Type (Operand_Typ)
9401 and then not Is_Class_Wide_Type (Operand_Typ)
9402 and then Is_Ancestor (Target_Typ, Operand_Typ)
9403 and then not Is_SPARK_Object_Reference (Operand)
9405 Check_SPARK_Restriction ("object required", Operand);
9408 Analyze_Dimension (N);
9410 -- Note: we do the Eval_Type_Conversion call before applying the
9411 -- required checks for a subtype conversion. This is important, since
9412 -- both are prepared under certain circumstances to change the type
9413 -- conversion to a constraint error node, but in the case of
9414 -- Eval_Type_Conversion this may reflect an illegality in the static
9415 -- case, and we would miss the illegality (getting only a warning
9416 -- message), if we applied the type conversion checks first.
9418 Eval_Type_Conversion (N);
9420 -- Even when evaluation is not possible, we may be able to simplify the
9421 -- conversion or its expression. This needs to be done before applying
9422 -- checks, since otherwise the checks may use the original expression
9423 -- and defeat the simplifications. This is specifically the case for
9424 -- elimination of the floating-point Truncation attribute in
9425 -- float-to-int conversions.
9427 Simplify_Type_Conversion (N);
9429 -- If after evaluation we still have a type conversion, then we may need
9430 -- to apply checks required for a subtype conversion.
9432 -- Skip these type conversion checks if universal fixed operands
9433 -- operands involved, since range checks are handled separately for
9434 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9436 if Nkind (N) = N_Type_Conversion
9437 and then not Is_Generic_Type (Root_Type (Target_Typ))
9438 and then Target_Typ /= Universal_Fixed
9439 and then Operand_Typ /= Universal_Fixed
9441 Apply_Type_Conversion_Checks (N);
9444 -- Issue warning for conversion of simple object to its own type. We
9445 -- have to test the original nodes, since they may have been rewritten
9446 -- by various optimizations.
9448 Orig_N := Original_Node (N);
9450 -- Here we test for a redundant conversion if the warning mode is
9451 -- active (and was not locally reset), and we have a type conversion
9452 -- from source not appearing in a generic instance.
9455 and then Nkind (Orig_N) = N_Type_Conversion
9456 and then Comes_From_Source (Orig_N)
9457 and then not In_Instance
9459 Orig_N := Original_Node (Expression (Orig_N));
9460 Orig_T := Target_Typ;
9462 -- If the node is part of a larger expression, the Target_Type
9463 -- may not be the original type of the node if the context is a
9464 -- condition. Recover original type to see if conversion is needed.
9466 if Is_Boolean_Type (Orig_T)
9467 and then Nkind (Parent (N)) in N_Op
9469 Orig_T := Etype (Parent (N));
9472 -- If we have an entity name, then give the warning if the entity
9473 -- is the right type, or if it is a loop parameter covered by the
9474 -- original type (that's needed because loop parameters have an
9475 -- odd subtype coming from the bounds).
9477 if (Is_Entity_Name (Orig_N)
9479 (Etype (Entity (Orig_N)) = Orig_T
9481 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
9482 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
9484 -- If not an entity, then type of expression must match
9486 or else Etype (Orig_N) = Orig_T
9488 -- One more check, do not give warning if the analyzed conversion
9489 -- has an expression with non-static bounds, and the bounds of the
9490 -- target are static. This avoids junk warnings in cases where the
9491 -- conversion is necessary to establish staticness, for example in
9492 -- a case statement.
9494 if not Is_OK_Static_Subtype (Operand_Typ)
9495 and then Is_OK_Static_Subtype (Target_Typ)
9499 -- Finally, if this type conversion occurs in a context requiring
9500 -- a prefix, and the expression is a qualified expression then the
9501 -- type conversion is not redundant, since a qualified expression
9502 -- is not a prefix, whereas a type conversion is. For example, "X
9503 -- := T'(Funx(...)).Y;" is illegal because a selected component
9504 -- requires a prefix, but a type conversion makes it legal: "X :=
9505 -- T(T'(Funx(...))).Y;"
9507 -- In Ada 2012, a qualified expression is a name, so this idiom is
9508 -- no longer needed, but we still suppress the warning because it
9509 -- seems unfriendly for warnings to pop up when you switch to the
9510 -- newer language version.
9512 elsif Nkind (Orig_N) = N_Qualified_Expression
9513 and then Nkind_In (Parent (N), N_Attribute_Reference,
9514 N_Indexed_Component,
9515 N_Selected_Component,
9517 N_Explicit_Dereference)
9521 -- Here we give the redundant conversion warning. If it is an
9522 -- entity, give the name of the entity in the message. If not,
9523 -- just mention the expression.
9526 if Is_Entity_Name (Orig_N) then
9527 Error_Msg_Node_2 := Orig_T;
9528 Error_Msg_NE -- CODEFIX
9529 ("?redundant conversion, & is of type &!",
9530 N, Entity (Orig_N));
9533 ("?redundant conversion, expression is of type&!",
9540 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
9541 -- No need to perform any interface conversion if the type of the
9542 -- expression coincides with the target type.
9544 if Ada_Version >= Ada_2005
9545 and then Full_Expander_Active
9546 and then Operand_Typ /= Target_Typ
9549 Opnd : Entity_Id := Operand_Typ;
9550 Target : Entity_Id := Target_Typ;
9553 if Is_Access_Type (Opnd) then
9554 Opnd := Designated_Type (Opnd);
9557 if Is_Access_Type (Target_Typ) then
9558 Target := Designated_Type (Target);
9561 if Opnd = Target then
9564 -- Conversion from interface type
9566 elsif Is_Interface (Opnd) then
9568 -- Ada 2005 (AI-217): Handle entities from limited views
9570 if From_With_Type (Opnd) then
9571 Error_Msg_Qual_Level := 99;
9572 Error_Msg_NE -- CODEFIX
9573 ("missing WITH clause on package &", N,
9574 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
9576 ("type conversions require visibility of the full view",
9579 elsif From_With_Type (Target)
9581 (Is_Access_Type (Target_Typ)
9582 and then Present (Non_Limited_View (Etype (Target))))
9584 Error_Msg_Qual_Level := 99;
9585 Error_Msg_NE -- CODEFIX
9586 ("missing WITH clause on package &", N,
9587 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
9589 ("type conversions require visibility of the full view",
9593 Expand_Interface_Conversion (N, Is_Static => False);
9596 -- Conversion to interface type
9598 elsif Is_Interface (Target) then
9602 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
9603 Opnd := Etype (Opnd);
9606 if not Interface_Present_In_Ancestor
9610 if Is_Class_Wide_Type (Opnd) then
9612 -- The static analysis is not enough to know if the
9613 -- interface is implemented or not. Hence we must pass
9614 -- the work to the expander to generate code to evaluate
9615 -- the conversion at run time.
9617 Expand_Interface_Conversion (N, Is_Static => False);
9620 Error_Msg_Name_1 := Chars (Etype (Target));
9621 Error_Msg_Name_2 := Chars (Opnd);
9623 ("wrong interface conversion (% is not a progenitor " &
9628 Expand_Interface_Conversion (N);
9633 end Resolve_Type_Conversion;
9635 ----------------------
9636 -- Resolve_Unary_Op --
9637 ----------------------
9639 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
9640 B_Typ : constant Entity_Id := Base_Type (Typ);
9641 R : constant Node_Id := Right_Opnd (N);
9647 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
9648 Error_Msg_Name_1 := Chars (Typ);
9649 Check_SPARK_Restriction
9650 ("unary operator not defined for modular type%", N);
9653 -- Deal with intrinsic unary operators
9655 if Comes_From_Source (N)
9656 and then Ekind (Entity (N)) = E_Function
9657 and then Is_Imported (Entity (N))
9658 and then Is_Intrinsic_Subprogram (Entity (N))
9660 Resolve_Intrinsic_Unary_Operator (N, Typ);
9664 -- Deal with universal cases
9666 if Etype (R) = Universal_Integer
9668 Etype (R) = Universal_Real
9670 Check_For_Visible_Operator (N, B_Typ);
9673 Set_Etype (N, B_Typ);
9676 -- Generate warning for expressions like abs (x mod 2)
9678 if Warn_On_Redundant_Constructs
9679 and then Nkind (N) = N_Op_Abs
9681 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
9683 if OK and then Hi >= Lo and then Lo >= 0 then
9684 Error_Msg_N -- CODEFIX
9685 ("?abs applied to known non-negative value has no effect", N);
9689 -- Deal with reference generation
9691 Check_Unset_Reference (R);
9692 Generate_Operator_Reference (N, B_Typ);
9693 Analyze_Dimension (N);
9696 -- Set overflow checking bit. Much cleverer code needed here eventually
9697 -- and perhaps the Resolve routines should be separated for the various
9698 -- arithmetic operations, since they will need different processing ???
9700 if Nkind (N) in N_Op then
9701 if not Overflow_Checks_Suppressed (Etype (N)) then
9702 Enable_Overflow_Check (N);
9706 -- Generate warning for expressions like -5 mod 3 for integers. No need
9707 -- to worry in the floating-point case, since parens do not affect the
9708 -- result so there is no point in giving in a warning.
9711 Norig : constant Node_Id := Original_Node (N);
9720 if Warn_On_Questionable_Missing_Parens
9721 and then Comes_From_Source (Norig)
9722 and then Is_Integer_Type (Typ)
9723 and then Nkind (Norig) = N_Op_Minus
9725 Rorig := Original_Node (Right_Opnd (Norig));
9727 -- We are looking for cases where the right operand is not
9728 -- parenthesized, and is a binary operator, multiply, divide, or
9729 -- mod. These are the cases where the grouping can affect results.
9731 if Paren_Count (Rorig) = 0
9732 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
9734 -- For mod, we always give the warning, since the value is
9735 -- affected by the parenthesization (e.g. (-5) mod 315 /=
9736 -- -(5 mod 315)). But for the other cases, the only concern is
9737 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
9738 -- overflows, but (-2) * 64 does not). So we try to give the
9739 -- message only when overflow is possible.
9741 if Nkind (Rorig) /= N_Op_Mod
9742 and then Compile_Time_Known_Value (R)
9744 Val := Expr_Value (R);
9746 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
9747 HB := Expr_Value (Type_High_Bound (Typ));
9749 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
9752 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
9753 LB := Expr_Value (Type_Low_Bound (Typ));
9755 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
9758 -- Note that the test below is deliberately excluding the
9759 -- largest negative number, since that is a potentially
9760 -- troublesome case (e.g. -2 * x, where the result is the
9761 -- largest negative integer has an overflow with 2 * x).
9763 if Val > LB and then Val <= HB then
9768 -- For the multiplication case, the only case we have to worry
9769 -- about is when (-a)*b is exactly the largest negative number
9770 -- so that -(a*b) can cause overflow. This can only happen if
9771 -- a is a power of 2, and more generally if any operand is a
9772 -- constant that is not a power of 2, then the parentheses
9773 -- cannot affect whether overflow occurs. We only bother to
9774 -- test the left most operand
9776 -- Loop looking at left operands for one that has known value
9779 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
9780 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
9781 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
9783 -- Operand value of 0 or 1 skips warning
9788 -- Otherwise check power of 2, if power of 2, warn, if
9789 -- anything else, skip warning.
9792 while Lval /= 2 loop
9793 if Lval mod 2 = 1 then
9804 -- Keep looking at left operands
9806 Opnd := Left_Opnd (Opnd);
9809 -- For rem or "/" we can only have a problematic situation
9810 -- if the divisor has a value of minus one or one. Otherwise
9811 -- overflow is impossible (divisor > 1) or we have a case of
9812 -- division by zero in any case.
9814 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
9815 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
9816 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
9821 -- If we fall through warning should be issued
9824 ("?unary minus expression should be parenthesized here!", N);
9828 end Resolve_Unary_Op;
9830 ----------------------------------
9831 -- Resolve_Unchecked_Expression --
9832 ----------------------------------
9834 procedure Resolve_Unchecked_Expression
9839 Resolve (Expression (N), Typ, Suppress => All_Checks);
9841 end Resolve_Unchecked_Expression;
9843 ---------------------------------------
9844 -- Resolve_Unchecked_Type_Conversion --
9845 ---------------------------------------
9847 procedure Resolve_Unchecked_Type_Conversion
9851 pragma Warnings (Off, Typ);
9853 Operand : constant Node_Id := Expression (N);
9854 Opnd_Type : constant Entity_Id := Etype (Operand);
9857 -- Resolve operand using its own type
9859 Resolve (Operand, Opnd_Type);
9860 Analyze_Dimension (N);
9861 Eval_Unchecked_Conversion (N);
9862 end Resolve_Unchecked_Type_Conversion;
9864 ------------------------------
9865 -- Rewrite_Operator_As_Call --
9866 ------------------------------
9868 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
9869 Loc : constant Source_Ptr := Sloc (N);
9870 Actuals : constant List_Id := New_List;
9874 if Nkind (N) in N_Binary_Op then
9875 Append (Left_Opnd (N), Actuals);
9878 Append (Right_Opnd (N), Actuals);
9881 Make_Function_Call (Sloc => Loc,
9882 Name => New_Occurrence_Of (Nam, Loc),
9883 Parameter_Associations => Actuals);
9885 Preserve_Comes_From_Source (New_N, N);
9886 Preserve_Comes_From_Source (Name (New_N), N);
9888 Set_Etype (N, Etype (Nam));
9889 end Rewrite_Operator_As_Call;
9891 ------------------------------
9892 -- Rewrite_Renamed_Operator --
9893 ------------------------------
9895 procedure Rewrite_Renamed_Operator
9900 Nam : constant Name_Id := Chars (Op);
9901 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
9905 -- Rewrite the operator node using the real operator, not its renaming.
9906 -- Exclude user-defined intrinsic operations of the same name, which are
9907 -- treated separately and rewritten as calls.
9909 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
9910 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
9911 Set_Chars (Op_Node, Nam);
9912 Set_Etype (Op_Node, Etype (N));
9913 Set_Entity (Op_Node, Op);
9914 Set_Right_Opnd (Op_Node, Right_Opnd (N));
9916 -- Indicate that both the original entity and its renaming are
9917 -- referenced at this point.
9919 Generate_Reference (Entity (N), N);
9920 Generate_Reference (Op, N);
9923 Set_Left_Opnd (Op_Node, Left_Opnd (N));
9926 Rewrite (N, Op_Node);
9928 -- If the context type is private, add the appropriate conversions so
9929 -- that the operator is applied to the full view. This is done in the
9930 -- routines that resolve intrinsic operators.
9932 if Is_Intrinsic_Subprogram (Op)
9933 and then Is_Private_Type (Typ)
9936 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
9937 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
9938 Resolve_Intrinsic_Operator (N, Typ);
9940 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
9941 Resolve_Intrinsic_Unary_Operator (N, Typ);
9948 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
9950 -- Operator renames a user-defined operator of the same name. Use the
9951 -- original operator in the node, which is the one Gigi knows about.
9954 Set_Is_Overloaded (N, False);
9956 end Rewrite_Renamed_Operator;
9958 -----------------------
9959 -- Set_Slice_Subtype --
9960 -----------------------
9962 -- Build an implicit subtype declaration to represent the type delivered by
9963 -- the slice. This is an abbreviated version of an array subtype. We define
9964 -- an index subtype for the slice, using either the subtype name or the
9965 -- discrete range of the slice. To be consistent with index usage elsewhere
9966 -- we create a list header to hold the single index. This list is not
9967 -- otherwise attached to the syntax tree.
9969 procedure Set_Slice_Subtype (N : Node_Id) is
9970 Loc : constant Source_Ptr := Sloc (N);
9971 Index_List : constant List_Id := New_List;
9973 Index_Subtype : Entity_Id;
9974 Index_Type : Entity_Id;
9975 Slice_Subtype : Entity_Id;
9976 Drange : constant Node_Id := Discrete_Range (N);
9979 if Is_Entity_Name (Drange) then
9980 Index_Subtype := Entity (Drange);
9983 -- We force the evaluation of a range. This is definitely needed in
9984 -- the renamed case, and seems safer to do unconditionally. Note in
9985 -- any case that since we will create and insert an Itype referring
9986 -- to this range, we must make sure any side effect removal actions
9987 -- are inserted before the Itype definition.
9989 if Nkind (Drange) = N_Range then
9990 Force_Evaluation (Low_Bound (Drange));
9991 Force_Evaluation (High_Bound (Drange));
9994 Index_Type := Base_Type (Etype (Drange));
9996 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9998 -- Take a new copy of Drange (where bounds have been rewritten to
9999 -- reference side-effect-free names). Using a separate tree ensures
10000 -- that further expansion (e.g. while rewriting a slice assignment
10001 -- into a FOR loop) does not attempt to remove side effects on the
10002 -- bounds again (which would cause the bounds in the index subtype
10003 -- definition to refer to temporaries before they are defined) (the
10004 -- reason is that some names are considered side effect free here
10005 -- for the subtype, but not in the context of a loop iteration
10008 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
10009 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
10010 Set_Etype (Index_Subtype, Index_Type);
10011 Set_Size_Info (Index_Subtype, Index_Type);
10012 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
10015 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
10017 Index := New_Occurrence_Of (Index_Subtype, Loc);
10018 Set_Etype (Index, Index_Subtype);
10019 Append (Index, Index_List);
10021 Set_First_Index (Slice_Subtype, Index);
10022 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
10023 Set_Is_Constrained (Slice_Subtype, True);
10025 Check_Compile_Time_Size (Slice_Subtype);
10027 -- The Etype of the existing Slice node is reset to this slice subtype.
10028 -- Its bounds are obtained from its first index.
10030 Set_Etype (N, Slice_Subtype);
10032 -- For packed slice subtypes, freeze immediately (except in the case of
10033 -- being in a "spec expression" where we never freeze when we first see
10034 -- the expression).
10036 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
10037 Freeze_Itype (Slice_Subtype, N);
10039 -- For all other cases insert an itype reference in the slice's actions
10040 -- so that the itype is frozen at the proper place in the tree (i.e. at
10041 -- the point where actions for the slice are analyzed). Note that this
10042 -- is different from freezing the itype immediately, which might be
10043 -- premature (e.g. if the slice is within a transient scope). This needs
10044 -- to be done only if expansion is enabled.
10046 elsif Full_Expander_Active then
10047 Ensure_Defined (Typ => Slice_Subtype, N => N);
10049 end Set_Slice_Subtype;
10051 --------------------------------
10052 -- Set_String_Literal_Subtype --
10053 --------------------------------
10055 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
10056 Loc : constant Source_Ptr := Sloc (N);
10057 Low_Bound : constant Node_Id :=
10058 Type_Low_Bound (Etype (First_Index (Typ)));
10059 Subtype_Id : Entity_Id;
10062 if Nkind (N) /= N_String_Literal then
10066 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
10067 Set_String_Literal_Length (Subtype_Id, UI_From_Int
10068 (String_Length (Strval (N))));
10069 Set_Etype (Subtype_Id, Base_Type (Typ));
10070 Set_Is_Constrained (Subtype_Id);
10071 Set_Etype (N, Subtype_Id);
10073 if Is_OK_Static_Expression (Low_Bound) then
10075 -- The low bound is set from the low bound of the corresponding index
10076 -- type. Note that we do not store the high bound in the string literal
10077 -- subtype, but it can be deduced if necessary from the length and the
10080 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
10083 -- If the lower bound is not static we create a range for the string
10084 -- literal, using the index type and the known length of the literal.
10085 -- The index type is not necessarily Positive, so the upper bound is
10086 -- computed as T'Val (T'Pos (Low_Bound) + L - 1)
10089 Index_List : constant List_Id := New_List;
10090 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
10092 High_Bound : constant Node_Id :=
10093 Make_Attribute_Reference (Loc,
10094 Attribute_Name => Name_Val,
10096 New_Occurrence_Of (Index_Type, Loc),
10097 Expressions => New_List (
10100 Make_Attribute_Reference (Loc,
10101 Attribute_Name => Name_Pos,
10103 New_Occurrence_Of (Index_Type, Loc),
10105 New_List (New_Copy_Tree (Low_Bound))),
10107 Make_Integer_Literal (Loc,
10108 String_Length (Strval (N)) - 1))));
10110 Array_Subtype : Entity_Id;
10111 Index_Subtype : Entity_Id;
10116 if Is_Integer_Type (Index_Type) then
10117 Set_String_Literal_Low_Bound
10118 (Subtype_Id, Make_Integer_Literal (Loc, 1));
10121 -- If the index type is an enumeration type, build bounds
10122 -- expression with attributes.
10124 Set_String_Literal_Low_Bound
10126 Make_Attribute_Reference (Loc,
10127 Attribute_Name => Name_First,
10129 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
10130 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
10133 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
10135 -- Build bona fide subtype for the string, and wrap it in an
10136 -- unchecked conversion, because the backend expects the
10137 -- String_Literal_Subtype to have a static lower bound.
10140 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
10141 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
10142 Set_Scalar_Range (Index_Subtype, Drange);
10143 Set_Parent (Drange, N);
10144 Analyze_And_Resolve (Drange, Index_Type);
10146 -- In the context, the Index_Type may already have a constraint,
10147 -- so use common base type on string subtype. The base type may
10148 -- be used when generating attributes of the string, for example
10149 -- in the context of a slice assignment.
10151 Set_Etype (Index_Subtype, Base_Type (Index_Type));
10152 Set_Size_Info (Index_Subtype, Index_Type);
10153 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
10155 Array_Subtype := Create_Itype (E_Array_Subtype, N);
10157 Index := New_Occurrence_Of (Index_Subtype, Loc);
10158 Set_Etype (Index, Index_Subtype);
10159 Append (Index, Index_List);
10161 Set_First_Index (Array_Subtype, Index);
10162 Set_Etype (Array_Subtype, Base_Type (Typ));
10163 Set_Is_Constrained (Array_Subtype, True);
10166 Make_Unchecked_Type_Conversion (Loc,
10167 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
10168 Expression => Relocate_Node (N)));
10169 Set_Etype (N, Array_Subtype);
10172 end Set_String_Literal_Subtype;
10174 ------------------------------
10175 -- Simplify_Type_Conversion --
10176 ------------------------------
10178 procedure Simplify_Type_Conversion (N : Node_Id) is
10180 if Nkind (N) = N_Type_Conversion then
10182 Operand : constant Node_Id := Expression (N);
10183 Target_Typ : constant Entity_Id := Etype (N);
10184 Opnd_Typ : constant Entity_Id := Etype (Operand);
10187 if Is_Floating_Point_Type (Opnd_Typ)
10189 (Is_Integer_Type (Target_Typ)
10190 or else (Is_Fixed_Point_Type (Target_Typ)
10191 and then Conversion_OK (N)))
10192 and then Nkind (Operand) = N_Attribute_Reference
10193 and then Attribute_Name (Operand) = Name_Truncation
10195 -- Special processing required if the conversion is the expression
10196 -- of a Truncation attribute reference. In this case we replace:
10198 -- ityp (ftyp'Truncation (x))
10204 -- with the Float_Truncate flag set, which is more efficient.
10208 Relocate_Node (First (Expressions (Operand))));
10209 Set_Float_Truncate (N, True);
10213 end Simplify_Type_Conversion;
10215 -----------------------------
10216 -- Unique_Fixed_Point_Type --
10217 -----------------------------
10219 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
10220 T1 : Entity_Id := Empty;
10225 procedure Fixed_Point_Error;
10226 -- Give error messages for true ambiguity. Messages are posted on node
10227 -- N, and entities T1, T2 are the possible interpretations.
10229 -----------------------
10230 -- Fixed_Point_Error --
10231 -----------------------
10233 procedure Fixed_Point_Error is
10235 Error_Msg_N ("ambiguous universal_fixed_expression", N);
10236 Error_Msg_NE ("\\possible interpretation as}", N, T1);
10237 Error_Msg_NE ("\\possible interpretation as}", N, T2);
10238 end Fixed_Point_Error;
10240 -- Start of processing for Unique_Fixed_Point_Type
10243 -- The operations on Duration are visible, so Duration is always a
10244 -- possible interpretation.
10246 T1 := Standard_Duration;
10248 -- Look for fixed-point types in enclosing scopes
10250 Scop := Current_Scope;
10251 while Scop /= Standard_Standard loop
10252 T2 := First_Entity (Scop);
10253 while Present (T2) loop
10254 if Is_Fixed_Point_Type (T2)
10255 and then Current_Entity (T2) = T2
10256 and then Scope (Base_Type (T2)) = Scop
10258 if Present (T1) then
10269 Scop := Scope (Scop);
10272 -- Look for visible fixed type declarations in the context
10274 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
10275 while Present (Item) loop
10276 if Nkind (Item) = N_With_Clause then
10277 Scop := Entity (Name (Item));
10278 T2 := First_Entity (Scop);
10279 while Present (T2) loop
10280 if Is_Fixed_Point_Type (T2)
10281 and then Scope (Base_Type (T2)) = Scop
10282 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
10284 if Present (T1) then
10299 if Nkind (N) = N_Real_Literal then
10300 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
10302 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
10306 end Unique_Fixed_Point_Type;
10308 ----------------------
10309 -- Valid_Conversion --
10310 ----------------------
10312 function Valid_Conversion
10314 Target : Entity_Id;
10316 Report_Errs : Boolean := True) return Boolean
10318 Target_Type : constant Entity_Id := Base_Type (Target);
10319 Opnd_Type : Entity_Id := Etype (Operand);
10321 function Conversion_Check
10323 Msg : String) return Boolean;
10324 -- Little routine to post Msg if Valid is False, returns Valid value
10326 -- The following are badly named, this kind of overloading is actively
10327 -- confusing in reading code, please rename to something like
10328 -- Error_Msg_N_If_Reporting ???
10330 procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id);
10331 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
10333 procedure Error_Msg_NE
10335 N : Node_Or_Entity_Id;
10336 E : Node_Or_Entity_Id);
10337 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
10339 function Valid_Tagged_Conversion
10340 (Target_Type : Entity_Id;
10341 Opnd_Type : Entity_Id) return Boolean;
10342 -- Specifically test for validity of tagged conversions
10344 function Valid_Array_Conversion return Boolean;
10345 -- Check index and component conformance, and accessibility levels if
10346 -- the component types are anonymous access types (Ada 2005).
10348 ----------------------
10349 -- Conversion_Check --
10350 ----------------------
10352 function Conversion_Check
10354 Msg : String) return Boolean
10359 -- A generic unit has already been analyzed and we have verified
10360 -- that a particular conversion is OK in that context. Since the
10361 -- instance is reanalyzed without relying on the relationships
10362 -- established during the analysis of the generic, it is possible
10363 -- to end up with inconsistent views of private types. Do not emit
10364 -- the error message in such cases. The rest of the machinery in
10365 -- Valid_Conversion still ensures the proper compatibility of
10366 -- target and operand types.
10368 and then not In_Instance
10370 Error_Msg_N (Msg, Operand);
10374 end Conversion_Check;
10380 procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id) is
10382 if Report_Errs then
10383 Errout.Error_Msg_N (Msg, N);
10391 procedure Error_Msg_NE
10393 N : Node_Or_Entity_Id;
10394 E : Node_Or_Entity_Id)
10397 if Report_Errs then
10398 Errout.Error_Msg_NE (Msg, N, E);
10402 ----------------------------
10403 -- Valid_Array_Conversion --
10404 ----------------------------
10406 function Valid_Array_Conversion return Boolean
10408 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
10409 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
10411 Opnd_Index : Node_Id;
10412 Opnd_Index_Type : Entity_Id;
10414 Target_Comp_Type : constant Entity_Id :=
10415 Component_Type (Target_Type);
10416 Target_Comp_Base : constant Entity_Id :=
10417 Base_Type (Target_Comp_Type);
10419 Target_Index : Node_Id;
10420 Target_Index_Type : Entity_Id;
10423 -- Error if wrong number of dimensions
10426 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
10429 ("incompatible number of dimensions for conversion", Operand);
10432 -- Number of dimensions matches
10435 -- Loop through indexes of the two arrays
10437 Target_Index := First_Index (Target_Type);
10438 Opnd_Index := First_Index (Opnd_Type);
10439 while Present (Target_Index) and then Present (Opnd_Index) loop
10440 Target_Index_Type := Etype (Target_Index);
10441 Opnd_Index_Type := Etype (Opnd_Index);
10443 -- Error if index types are incompatible
10445 if not (Is_Integer_Type (Target_Index_Type)
10446 and then Is_Integer_Type (Opnd_Index_Type))
10447 and then (Root_Type (Target_Index_Type)
10448 /= Root_Type (Opnd_Index_Type))
10451 ("incompatible index types for array conversion",
10456 Next_Index (Target_Index);
10457 Next_Index (Opnd_Index);
10460 -- If component types have same base type, all set
10462 if Target_Comp_Base = Opnd_Comp_Base then
10465 -- Here if base types of components are not the same. The only
10466 -- time this is allowed is if we have anonymous access types.
10468 -- The conversion of arrays of anonymous access types can lead
10469 -- to dangling pointers. AI-392 formalizes the accessibility
10470 -- checks that must be applied to such conversions to prevent
10471 -- out-of-scope references.
10474 (Target_Comp_Base, E_Anonymous_Access_Type,
10475 E_Anonymous_Access_Subprogram_Type)
10476 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
10478 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
10480 if Type_Access_Level (Target_Type) <
10481 Deepest_Type_Access_Level (Opnd_Type)
10483 if In_Instance_Body then
10485 ("?source array type has " &
10486 "deeper accessibility level than target", Operand);
10488 ("\?Program_Error will be raised at run time",
10491 Make_Raise_Program_Error (Sloc (N),
10492 Reason => PE_Accessibility_Check_Failed));
10493 Set_Etype (N, Target_Type);
10496 -- Conversion not allowed because of accessibility levels
10500 ("source array type has " &
10501 "deeper accessibility level than target", Operand);
10509 -- All other cases where component base types do not match
10513 ("incompatible component types for array conversion",
10518 -- Check that component subtypes statically match. For numeric
10519 -- types this means that both must be either constrained or
10520 -- unconstrained. For enumeration types the bounds must match.
10521 -- All of this is checked in Subtypes_Statically_Match.
10523 if not Subtypes_Statically_Match
10524 (Target_Comp_Type, Opnd_Comp_Type)
10527 ("component subtypes must statically match", Operand);
10533 end Valid_Array_Conversion;
10535 -----------------------------
10536 -- Valid_Tagged_Conversion --
10537 -----------------------------
10539 function Valid_Tagged_Conversion
10540 (Target_Type : Entity_Id;
10541 Opnd_Type : Entity_Id) return Boolean
10544 -- Upward conversions are allowed (RM 4.6(22))
10546 if Covers (Target_Type, Opnd_Type)
10547 or else Is_Ancestor (Target_Type, Opnd_Type)
10551 -- Downward conversion are allowed if the operand is class-wide
10554 elsif Is_Class_Wide_Type (Opnd_Type)
10555 and then Covers (Opnd_Type, Target_Type)
10559 elsif Covers (Opnd_Type, Target_Type)
10560 or else Is_Ancestor (Opnd_Type, Target_Type)
10563 Conversion_Check (False,
10564 "downward conversion of tagged objects not allowed");
10566 -- Ada 2005 (AI-251): The conversion to/from interface types is
10569 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
10572 -- If the operand is a class-wide type obtained through a limited_
10573 -- with clause, and the context includes the non-limited view, use
10574 -- it to determine whether the conversion is legal.
10576 elsif Is_Class_Wide_Type (Opnd_Type)
10577 and then From_With_Type (Opnd_Type)
10578 and then Present (Non_Limited_View (Etype (Opnd_Type)))
10579 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
10583 elsif Is_Access_Type (Opnd_Type)
10584 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
10590 ("invalid tagged conversion, not compatible with}",
10591 N, First_Subtype (Opnd_Type));
10594 end Valid_Tagged_Conversion;
10596 -- Start of processing for Valid_Conversion
10599 Check_Parameterless_Call (Operand);
10601 if Is_Overloaded (Operand) then
10611 -- Remove procedure calls, which syntactically cannot appear in
10612 -- this context, but which cannot be removed by type checking,
10613 -- because the context does not impose a type.
10615 -- When compiling for VMS, spurious ambiguities can be produced
10616 -- when arithmetic operations have a literal operand and return
10617 -- System.Address or a descendant of it. These ambiguities are
10618 -- otherwise resolved by the context, but for conversions there
10619 -- is no context type and the removal of the spurious operations
10620 -- must be done explicitly here.
10622 -- The node may be labelled overloaded, but still contain only one
10623 -- interpretation because others were discarded earlier. If this
10624 -- is the case, retain the single interpretation if legal.
10626 Get_First_Interp (Operand, I, It);
10627 Opnd_Type := It.Typ;
10628 Get_Next_Interp (I, It);
10630 if Present (It.Typ)
10631 and then Opnd_Type /= Standard_Void_Type
10633 -- More than one candidate interpretation is available
10635 Get_First_Interp (Operand, I, It);
10636 while Present (It.Typ) loop
10637 if It.Typ = Standard_Void_Type then
10641 if Present (System_Aux_Id)
10642 and then Is_Descendent_Of_Address (It.Typ)
10647 Get_Next_Interp (I, It);
10651 Get_First_Interp (Operand, I, It);
10655 if No (It.Typ) then
10656 Error_Msg_N ("illegal operand in conversion", Operand);
10660 Get_Next_Interp (I, It);
10662 if Present (It.Typ) then
10665 It1 := Disambiguate (Operand, I1, I, Any_Type);
10667 if It1 = No_Interp then
10668 Error_Msg_N ("ambiguous operand in conversion", Operand);
10670 -- If the interpretation involves a standard operator, use
10671 -- the location of the type, which may be user-defined.
10673 if Sloc (It.Nam) = Standard_Location then
10674 Error_Msg_Sloc := Sloc (It.Typ);
10676 Error_Msg_Sloc := Sloc (It.Nam);
10679 Error_Msg_N -- CODEFIX
10680 ("\\possible interpretation#!", Operand);
10682 if Sloc (N1) = Standard_Location then
10683 Error_Msg_Sloc := Sloc (T1);
10685 Error_Msg_Sloc := Sloc (N1);
10688 Error_Msg_N -- CODEFIX
10689 ("\\possible interpretation#!", Operand);
10695 Set_Etype (Operand, It1.Typ);
10696 Opnd_Type := It1.Typ;
10702 if Is_Numeric_Type (Target_Type) then
10704 -- A universal fixed expression can be converted to any numeric type
10706 if Opnd_Type = Universal_Fixed then
10709 -- Also no need to check when in an instance or inlined body, because
10710 -- the legality has been established when the template was analyzed.
10711 -- Furthermore, numeric conversions may occur where only a private
10712 -- view of the operand type is visible at the instantiation point.
10713 -- This results in a spurious error if we check that the operand type
10714 -- is a numeric type.
10716 -- Note: in a previous version of this unit, the following tests were
10717 -- applied only for generated code (Comes_From_Source set to False),
10718 -- but in fact the test is required for source code as well, since
10719 -- this situation can arise in source code.
10721 elsif In_Instance or else In_Inlined_Body then
10724 -- Otherwise we need the conversion check
10727 return Conversion_Check
10728 (Is_Numeric_Type (Opnd_Type),
10729 "illegal operand for numeric conversion");
10734 elsif Is_Array_Type (Target_Type) then
10735 if not Is_Array_Type (Opnd_Type)
10736 or else Opnd_Type = Any_Composite
10737 or else Opnd_Type = Any_String
10739 Error_Msg_N ("illegal operand for array conversion", Operand);
10742 return Valid_Array_Conversion;
10745 -- Ada 2005 (AI-251): Anonymous access types where target references an
10748 elsif Ekind_In (Target_Type, E_General_Access_Type,
10749 E_Anonymous_Access_Type)
10750 and then Is_Interface (Directly_Designated_Type (Target_Type))
10752 -- Check the static accessibility rule of 4.6(17). Note that the
10753 -- check is not enforced when within an instance body, since the
10754 -- RM requires such cases to be caught at run time.
10756 -- If the operand is a rewriting of an allocator no check is needed
10757 -- because there are no accessibility issues.
10759 if Nkind (Original_Node (N)) = N_Allocator then
10762 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
10763 if Type_Access_Level (Opnd_Type) >
10764 Deepest_Type_Access_Level (Target_Type)
10766 -- In an instance, this is a run-time check, but one we know
10767 -- will fail, so generate an appropriate warning. The raise
10768 -- will be generated by Expand_N_Type_Conversion.
10770 if In_Instance_Body then
10772 ("?cannot convert local pointer to non-local access type",
10775 ("\?Program_Error will be raised at run time", Operand);
10779 ("cannot convert local pointer to non-local access type",
10784 -- Special accessibility checks are needed in the case of access
10785 -- discriminants declared for a limited type.
10787 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10788 and then not Is_Local_Anonymous_Access (Opnd_Type)
10790 -- When the operand is a selected access discriminant the check
10791 -- needs to be made against the level of the object denoted by
10792 -- the prefix of the selected name (Object_Access_Level handles
10793 -- checking the prefix of the operand for this case).
10795 if Nkind (Operand) = N_Selected_Component
10796 and then Object_Access_Level (Operand) >
10797 Deepest_Type_Access_Level (Target_Type)
10799 -- In an instance, this is a run-time check, but one we know
10800 -- will fail, so generate an appropriate warning. The raise
10801 -- will be generated by Expand_N_Type_Conversion.
10803 if In_Instance_Body then
10805 ("?cannot convert access discriminant to non-local" &
10806 " access type", Operand);
10808 ("\?Program_Error will be raised at run time", Operand);
10811 ("cannot convert access discriminant to non-local" &
10812 " access type", Operand);
10817 -- The case of a reference to an access discriminant from
10818 -- within a limited type declaration (which will appear as
10819 -- a discriminal) is always illegal because the level of the
10820 -- discriminant is considered to be deeper than any (nameable)
10823 if Is_Entity_Name (Operand)
10824 and then not Is_Local_Anonymous_Access (Opnd_Type)
10826 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
10827 and then Present (Discriminal_Link (Entity (Operand)))
10830 ("discriminant has deeper accessibility level than target",
10839 -- General and anonymous access types
10841 elsif Ekind_In (Target_Type, E_General_Access_Type,
10842 E_Anonymous_Access_Type)
10845 (Is_Access_Type (Opnd_Type)
10847 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
10848 E_Access_Protected_Subprogram_Type),
10849 "must be an access-to-object type")
10851 if Is_Access_Constant (Opnd_Type)
10852 and then not Is_Access_Constant (Target_Type)
10855 ("access-to-constant operand type not allowed", Operand);
10859 -- Check the static accessibility rule of 4.6(17). Note that the
10860 -- check is not enforced when within an instance body, since the RM
10861 -- requires such cases to be caught at run time.
10863 if Ekind (Target_Type) /= E_Anonymous_Access_Type
10864 or else Is_Local_Anonymous_Access (Target_Type)
10865 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
10866 N_Object_Declaration
10868 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
10869 -- conversions from an anonymous access type to a named general
10870 -- access type. Such conversions are not allowed in the case of
10871 -- access parameters and stand-alone objects of an anonymous
10872 -- access type. The implicit conversion case is recognized by
10873 -- testing that Comes_From_Source is False and that it's been
10874 -- rewritten. The Comes_From_Source test isn't sufficient because
10875 -- nodes in inlined calls to predefined library routines can have
10876 -- Comes_From_Source set to False. (Is there a better way to test
10877 -- for implicit conversions???)
10879 if Ada_Version >= Ada_2012
10880 and then not Comes_From_Source (N)
10881 and then N /= Original_Node (N)
10882 and then Ekind (Target_Type) = E_General_Access_Type
10883 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
10885 if Is_Itype (Opnd_Type) then
10887 -- Implicit conversions aren't allowed for objects of an
10888 -- anonymous access type, since such objects have nonstatic
10889 -- levels in Ada 2012.
10891 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
10892 N_Object_Declaration
10895 ("implicit conversion of stand-alone anonymous " &
10896 "access object not allowed", Operand);
10899 -- Implicit conversions aren't allowed for anonymous access
10900 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
10901 -- is done to exclude anonymous access results.
10903 elsif not Is_Local_Anonymous_Access (Opnd_Type)
10904 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
10905 N_Function_Specification,
10906 N_Procedure_Specification)
10909 ("implicit conversion of anonymous access formal " &
10910 "not allowed", Operand);
10913 -- This is a case where there's an enclosing object whose
10914 -- to which the "statically deeper than" relationship does
10915 -- not apply (such as an access discriminant selected from
10916 -- a dereference of an access parameter).
10918 elsif Object_Access_Level (Operand)
10919 = Scope_Depth (Standard_Standard)
10922 ("implicit conversion of anonymous access value " &
10923 "not allowed", Operand);
10926 -- In other cases, the level of the operand's type must be
10927 -- statically less deep than that of the target type, else
10928 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
10930 elsif Type_Access_Level (Opnd_Type) >
10931 Deepest_Type_Access_Level (Target_Type)
10934 ("implicit conversion of anonymous access value " &
10935 "violates accessibility", Operand);
10940 elsif Type_Access_Level (Opnd_Type) >
10941 Deepest_Type_Access_Level (Target_Type)
10943 -- In an instance, this is a run-time check, but one we know
10944 -- will fail, so generate an appropriate warning. The raise
10945 -- will be generated by Expand_N_Type_Conversion.
10947 if In_Instance_Body then
10949 ("?cannot convert local pointer to non-local access type",
10952 ("\?Program_Error will be raised at run time", Operand);
10955 -- Avoid generation of spurious error message
10957 if not Error_Posted (N) then
10959 ("cannot convert local pointer to non-local access type",
10966 -- Special accessibility checks are needed in the case of access
10967 -- discriminants declared for a limited type.
10969 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10970 and then not Is_Local_Anonymous_Access (Opnd_Type)
10972 -- When the operand is a selected access discriminant the check
10973 -- needs to be made against the level of the object denoted by
10974 -- the prefix of the selected name (Object_Access_Level handles
10975 -- checking the prefix of the operand for this case).
10977 if Nkind (Operand) = N_Selected_Component
10978 and then Object_Access_Level (Operand) >
10979 Deepest_Type_Access_Level (Target_Type)
10981 -- In an instance, this is a run-time check, but one we know
10982 -- will fail, so generate an appropriate warning. The raise
10983 -- will be generated by Expand_N_Type_Conversion.
10985 if In_Instance_Body then
10987 ("?cannot convert access discriminant to non-local" &
10988 " access type", Operand);
10990 ("\?Program_Error will be raised at run time",
10995 ("cannot convert access discriminant to non-local" &
10996 " access type", Operand);
11001 -- The case of a reference to an access discriminant from
11002 -- within a limited type declaration (which will appear as
11003 -- a discriminal) is always illegal because the level of the
11004 -- discriminant is considered to be deeper than any (nameable)
11007 if Is_Entity_Name (Operand)
11009 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
11010 and then Present (Discriminal_Link (Entity (Operand)))
11013 ("discriminant has deeper accessibility level than target",
11020 -- In the presence of limited_with clauses we have to use non-limited
11021 -- views, if available.
11023 Check_Limited : declare
11024 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
11025 -- Helper function to handle limited views
11027 --------------------------
11028 -- Full_Designated_Type --
11029 --------------------------
11031 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
11032 Desig : constant Entity_Id := Designated_Type (T);
11035 -- Handle the limited view of a type
11037 if Is_Incomplete_Type (Desig)
11038 and then From_With_Type (Desig)
11039 and then Present (Non_Limited_View (Desig))
11041 return Available_View (Desig);
11045 end Full_Designated_Type;
11047 -- Local Declarations
11049 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
11050 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
11052 Same_Base : constant Boolean :=
11053 Base_Type (Target) = Base_Type (Opnd);
11055 -- Start of processing for Check_Limited
11058 if Is_Tagged_Type (Target) then
11059 return Valid_Tagged_Conversion (Target, Opnd);
11062 if not Same_Base then
11064 ("target designated type not compatible with }",
11065 N, Base_Type (Opnd));
11068 -- Ada 2005 AI-384: legality rule is symmetric in both
11069 -- designated types. The conversion is legal (with possible
11070 -- constraint check) if either designated type is
11073 elsif Subtypes_Statically_Match (Target, Opnd)
11075 (Has_Discriminants (Target)
11077 (not Is_Constrained (Opnd)
11078 or else not Is_Constrained (Target)))
11080 -- Special case, if Value_Size has been used to make the
11081 -- sizes different, the conversion is not allowed even
11082 -- though the subtypes statically match.
11084 if Known_Static_RM_Size (Target)
11085 and then Known_Static_RM_Size (Opnd)
11086 and then RM_Size (Target) /= RM_Size (Opnd)
11089 ("target designated subtype not compatible with }",
11092 ("\because sizes of the two designated subtypes differ",
11096 -- Normal case where conversion is allowed
11104 ("target designated subtype not compatible with }",
11111 -- Access to subprogram types. If the operand is an access parameter,
11112 -- the type has a deeper accessibility that any master, and cannot be
11113 -- assigned. We must make an exception if the conversion is part of an
11114 -- assignment and the target is the return object of an extended return
11115 -- statement, because in that case the accessibility check takes place
11116 -- after the return.
11118 elsif Is_Access_Subprogram_Type (Target_Type)
11119 and then No (Corresponding_Remote_Type (Opnd_Type))
11121 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
11122 and then Is_Entity_Name (Operand)
11123 and then Ekind (Entity (Operand)) = E_In_Parameter
11125 (Nkind (Parent (N)) /= N_Assignment_Statement
11126 or else not Is_Entity_Name (Name (Parent (N)))
11127 or else not Is_Return_Object (Entity (Name (Parent (N)))))
11130 ("illegal attempt to store anonymous access to subprogram",
11133 ("\value has deeper accessibility than any master " &
11134 "(RM 3.10.2 (13))",
11138 ("\use named access type for& instead of access parameter",
11139 Operand, Entity (Operand));
11142 -- Check that the designated types are subtype conformant
11144 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
11145 Old_Id => Designated_Type (Opnd_Type),
11148 -- Check the static accessibility rule of 4.6(20)
11150 if Type_Access_Level (Opnd_Type) >
11151 Deepest_Type_Access_Level (Target_Type)
11154 ("operand type has deeper accessibility level than target",
11157 -- Check that if the operand type is declared in a generic body,
11158 -- then the target type must be declared within that same body
11159 -- (enforces last sentence of 4.6(20)).
11161 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
11163 O_Gen : constant Node_Id :=
11164 Enclosing_Generic_Body (Opnd_Type);
11169 T_Gen := Enclosing_Generic_Body (Target_Type);
11170 while Present (T_Gen) and then T_Gen /= O_Gen loop
11171 T_Gen := Enclosing_Generic_Body (T_Gen);
11174 if T_Gen /= O_Gen then
11176 ("target type must be declared in same generic body"
11177 & " as operand type", N);
11184 -- Remote subprogram access types
11186 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
11187 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
11189 -- It is valid to convert from one RAS type to another provided
11190 -- that their specification statically match.
11192 Check_Subtype_Conformant
11194 Designated_Type (Corresponding_Remote_Type (Target_Type)),
11196 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
11201 -- If it was legal in the generic, it's legal in the instance
11203 elsif In_Instance_Body then
11206 -- If both are tagged types, check legality of view conversions
11208 elsif Is_Tagged_Type (Target_Type)
11210 Is_Tagged_Type (Opnd_Type)
11212 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
11214 -- Types derived from the same root type are convertible
11216 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
11219 -- In an instance or an inlined body, there may be inconsistent views of
11220 -- the same type, or of types derived from a common root.
11222 elsif (In_Instance or In_Inlined_Body)
11224 Root_Type (Underlying_Type (Target_Type)) =
11225 Root_Type (Underlying_Type (Opnd_Type))
11229 -- Special check for common access type error case
11231 elsif Ekind (Target_Type) = E_Access_Type
11232 and then Is_Access_Type (Opnd_Type)
11234 Error_Msg_N ("target type must be general access type!", N);
11235 Error_Msg_NE -- CODEFIX
11236 ("add ALL to }!", N, Target_Type);
11240 Error_Msg_NE ("invalid conversion, not compatible with }",
11244 end Valid_Conversion;
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