1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2014, 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 procedure Check_Discriminant_Use (N : Node_Id);
97 -- Enforce the restrictions on the use of discriminants when constraining
98 -- a component of a discriminated type (record or concurrent type).
100 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
101 -- Given a node for an operator associated with type T, check that
102 -- the operator is visible. Operators all of whose operands are
103 -- universal must be checked for visibility during resolution
104 -- because their type is not determinable based on their operands.
106 procedure Check_Fully_Declared_Prefix
109 -- Check that the type of the prefix of a dereference is not incomplete
111 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
112 -- Given a call node, N, which is known to occur immediately within the
113 -- subprogram being called, determines whether it is a detectable case of
114 -- an infinite recursion, and if so, outputs appropriate messages. Returns
115 -- True if an infinite recursion is detected, and False otherwise.
117 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
118 -- If the type of the object being initialized uses the secondary stack
119 -- directly or indirectly, create a transient scope for the call to the
120 -- init proc. This is because we do not create transient scopes for the
121 -- initialization of individual components within the init proc itself.
122 -- Could be optimized away perhaps?
124 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
125 -- N is the node for a logical operator. If the operator is predefined, and
126 -- the root type of the operands is Standard.Boolean, then a check is made
127 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
128 -- the style check for Style_Check_Boolean_And_Or.
130 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
131 -- Determine whether E is an access type declared by an access declaration,
132 -- and not an (anonymous) allocator type.
134 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
135 -- Utility to check whether the entity for an operator is a predefined
136 -- operator, in which case the expression is left as an operator in the
137 -- tree (else it is rewritten into a call). An instance of an intrinsic
138 -- conversion operation may be given an operator name, but is not treated
139 -- like an operator. Note that an operator that is an imported back-end
140 -- builtin has convention Intrinsic, but is expected to be rewritten into
141 -- a call, so such an operator is not treated as predefined by this
144 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
145 -- If a default expression in entry call N depends on the discriminants
146 -- of the task, it must be replaced with a reference to the discriminant
147 -- of the task being called.
149 procedure Resolve_Op_Concat_Arg
154 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
155 -- concatenation operator. The operand is either of the array type or of
156 -- the component type. If the operand is an aggregate, and the component
157 -- type is composite, this is ambiguous if component type has aggregates.
159 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
160 -- Does the first part of the work of Resolve_Op_Concat
162 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
163 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
164 -- has been resolved. See Resolve_Op_Concat for details.
166 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
202 function Operator_Kind
204 Is_Binary : Boolean) return Node_Kind;
205 -- Utility to map the name of an operator into the corresponding Node. Used
206 -- by other node rewriting procedures.
208 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
209 -- Resolve actuals of call, and add default expressions for missing ones.
210 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
211 -- called subprogram.
213 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
214 -- Called from Resolve_Call, when the prefix denotes an entry or element
215 -- of entry family. Actuals are resolved as for subprograms, and the node
216 -- is rebuilt as an entry call. Also called for protected operations. Typ
217 -- is the context type, which is used when the operation is a protected
218 -- function with no arguments, and the return value is indexed.
220 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
221 -- A call to a user-defined intrinsic operator is rewritten as a call to
222 -- the corresponding predefined operator, with suitable conversions. Note
223 -- that this applies only for intrinsic operators that denote predefined
224 -- operators, not ones that are intrinsic imports of back-end builtins.
226 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
227 -- Ditto, for unary operators (arithmetic ones and "not" on signed
228 -- integer types for VMS).
230 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
231 -- If an operator node resolves to a call to a user-defined operator,
232 -- rewrite the node as a function call.
234 procedure Make_Call_Into_Operator
238 -- Inverse transformation: if an operator is given in functional notation,
239 -- then after resolving the node, transform into an operator node, so
240 -- that operands are resolved properly. Recall that predefined operators
241 -- do not have a full signature and special resolution rules apply.
243 procedure Rewrite_Renamed_Operator
247 -- An operator can rename another, e.g. in an instantiation. In that
248 -- case, the proper operator node must be constructed and resolved.
250 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
251 -- The String_Literal_Subtype is built for all strings that are not
252 -- operands of a static concatenation operation. If the argument is
253 -- not a N_String_Literal node, then the call has no effect.
255 procedure Set_Slice_Subtype (N : Node_Id);
256 -- Build subtype of array type, with the range specified by the slice
258 procedure Simplify_Type_Conversion (N : Node_Id);
259 -- Called after N has been resolved and evaluated, but before range checks
260 -- have been applied. Currently simplifies a combination of floating-point
261 -- to integer conversion and Truncation attribute.
263 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
264 -- A universal_fixed expression in an universal context is unambiguous if
265 -- there is only one applicable fixed point type. Determining whether there
266 -- is only one requires a search over all visible entities, and happens
267 -- only in very pathological cases (see 6115-006).
269 -------------------------
270 -- Ambiguous_Character --
271 -------------------------
273 procedure Ambiguous_Character (C : Node_Id) is
277 if Nkind (C) = N_Character_Literal then
278 Error_Msg_N ("ambiguous character literal", C);
280 -- First the ones in Standard
282 Error_Msg_N ("\\possible interpretation: Character!", C);
283 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
285 -- Include Wide_Wide_Character in Ada 2005 mode
287 if Ada_Version >= Ada_2005 then
288 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
291 -- Now any other types that match
293 E := Current_Entity (C);
294 while Present (E) loop
295 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
299 end Ambiguous_Character;
301 -------------------------
302 -- Analyze_And_Resolve --
303 -------------------------
305 procedure Analyze_And_Resolve (N : Node_Id) is
309 end Analyze_And_Resolve;
311 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
315 end Analyze_And_Resolve;
317 -- Versions with check(s) suppressed
319 procedure Analyze_And_Resolve
324 Scop : constant Entity_Id := Current_Scope;
327 if Suppress = All_Checks then
329 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
331 Scope_Suppress.Suppress := (others => True);
332 Analyze_And_Resolve (N, Typ);
333 Scope_Suppress.Suppress := Sva;
338 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
340 Scope_Suppress.Suppress (Suppress) := True;
341 Analyze_And_Resolve (N, Typ);
342 Scope_Suppress.Suppress (Suppress) := Svg;
346 if Current_Scope /= Scop
347 and then Scope_Is_Transient
349 -- This can only happen if a transient scope was created for an inner
350 -- expression, which will be removed upon completion of the analysis
351 -- of an enclosing construct. The transient scope must have the
352 -- suppress status of the enclosing environment, not of this Analyze
355 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
358 end Analyze_And_Resolve;
360 procedure Analyze_And_Resolve
364 Scop : constant Entity_Id := Current_Scope;
367 if Suppress = All_Checks then
369 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
371 Scope_Suppress.Suppress := (others => True);
372 Analyze_And_Resolve (N);
373 Scope_Suppress.Suppress := Sva;
378 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
380 Scope_Suppress.Suppress (Suppress) := True;
381 Analyze_And_Resolve (N);
382 Scope_Suppress.Suppress (Suppress) := Svg;
386 if Current_Scope /= Scop and then Scope_Is_Transient then
387 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
390 end Analyze_And_Resolve;
392 ----------------------------
393 -- Check_Discriminant_Use --
394 ----------------------------
396 procedure Check_Discriminant_Use (N : Node_Id) is
397 PN : constant Node_Id := Parent (N);
398 Disc : constant Entity_Id := Entity (N);
403 -- Any use in a spec-expression is legal
405 if In_Spec_Expression then
408 elsif Nkind (PN) = N_Range then
410 -- Discriminant cannot be used to constrain a scalar type
414 if Nkind (P) = N_Range_Constraint
415 and then Nkind (Parent (P)) = N_Subtype_Indication
416 and then Nkind (Parent (Parent (P))) = N_Component_Definition
418 Error_Msg_N ("discriminant cannot constrain scalar type", N);
420 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
422 -- The following check catches the unusual case where a
423 -- discriminant appears within an index constraint that is part of
424 -- a larger expression within a constraint on a component, e.g. "C
425 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
426 -- of record components, and note that a similar check should also
427 -- apply in the case of discriminant constraints below. ???
429 -- Note that the check for N_Subtype_Declaration below is to
430 -- detect the valid use of discriminants in the constraints of a
431 -- subtype declaration when this subtype declaration appears
432 -- inside the scope of a record type (which is syntactically
433 -- illegal, but which may be created as part of derived type
434 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
437 if Ekind (Current_Scope) = E_Record_Type
438 and then Scope (Disc) = Current_Scope
440 (Nkind (Parent (P)) = N_Subtype_Indication
442 Nkind_In (Parent (Parent (P)), N_Component_Definition,
443 N_Subtype_Declaration)
444 and then Paren_Count (N) = 0)
447 ("discriminant must appear alone in component constraint", N);
451 -- Detect a common error:
453 -- type R (D : Positive := 100) is record
454 -- Name : String (1 .. D);
457 -- The default value causes an object of type R to be allocated
458 -- with room for Positive'Last characters. The RM does not mandate
459 -- the allocation of the maximum size, but that is what GNAT does
460 -- so we should warn the programmer that there is a problem.
462 Check_Large : declare
468 function Large_Storage_Type (T : Entity_Id) return Boolean;
469 -- Return True if type T has a large enough range that any
470 -- array whose index type covered the whole range of the type
471 -- would likely raise Storage_Error.
473 ------------------------
474 -- Large_Storage_Type --
475 ------------------------
477 function Large_Storage_Type (T : Entity_Id) return Boolean is
479 -- The type is considered large if its bounds are known at
480 -- compile time and if it requires at least as many bits as
481 -- a Positive to store the possible values.
483 return Compile_Time_Known_Value (Type_Low_Bound (T))
484 and then Compile_Time_Known_Value (Type_High_Bound (T))
486 Minimum_Size (T, Biased => True) >=
487 RM_Size (Standard_Positive);
488 end Large_Storage_Type;
490 -- Start of processing for Check_Large
493 -- Check that the Disc has a large range
495 if not Large_Storage_Type (Etype (Disc)) then
499 -- If the enclosing type is limited, we allocate only the
500 -- default value, not the maximum, and there is no need for
503 if Is_Limited_Type (Scope (Disc)) then
507 -- Check that it is the high bound
509 if N /= High_Bound (PN)
510 or else No (Discriminant_Default_Value (Disc))
515 -- Check the array allows a large range at this bound. First
520 if Nkind (SI) /= N_Subtype_Indication then
524 T := Entity (Subtype_Mark (SI));
526 if not Is_Array_Type (T) then
530 -- Next, find the dimension
532 TB := First_Index (T);
533 CB := First (Constraints (P));
535 and then Present (TB)
536 and then Present (CB)
547 -- Now, check the dimension has a large range
549 if not Large_Storage_Type (Etype (TB)) then
553 -- Warn about the danger
556 ("??creation of & object may raise Storage_Error!",
565 -- Legal case is in index or discriminant constraint
567 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
568 N_Discriminant_Association)
570 if Paren_Count (N) > 0 then
572 ("discriminant in constraint must appear alone", N);
574 elsif Nkind (N) = N_Expanded_Name
575 and then Comes_From_Source (N)
578 ("discriminant must appear alone as a direct name", N);
583 -- Otherwise, context is an expression. It should not be within (i.e. a
584 -- subexpression of) a constraint for a component.
589 while not Nkind_In (P, N_Component_Declaration,
590 N_Subtype_Indication,
598 -- If the discriminant is used in an expression that is a bound of a
599 -- scalar type, an Itype is created and the bounds are attached to
600 -- its range, not to the original subtype indication. Such use is of
601 -- course a double fault.
603 if (Nkind (P) = N_Subtype_Indication
604 and then Nkind_In (Parent (P), N_Component_Definition,
605 N_Derived_Type_Definition)
606 and then D = Constraint (P))
608 -- The constraint itself may be given by a subtype indication,
609 -- rather than by a more common discrete range.
611 or else (Nkind (P) = N_Subtype_Indication
613 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
614 or else Nkind (P) = N_Entry_Declaration
615 or else Nkind (D) = N_Defining_Identifier
618 ("discriminant in constraint must appear alone", N);
621 end Check_Discriminant_Use;
623 --------------------------------
624 -- Check_For_Visible_Operator --
625 --------------------------------
627 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
629 if Is_Invisible_Operator (N, T) then
630 Error_Msg_NE -- CODEFIX
631 ("operator for} is not directly visible!", N, First_Subtype (T));
632 Error_Msg_N -- CODEFIX
633 ("use clause would make operation legal!", N);
635 end Check_For_Visible_Operator;
637 ----------------------------------
638 -- Check_Fully_Declared_Prefix --
639 ----------------------------------
641 procedure Check_Fully_Declared_Prefix
646 -- Check that the designated type of the prefix of a dereference is
647 -- not an incomplete type. This cannot be done unconditionally, because
648 -- dereferences of private types are legal in default expressions. This
649 -- case is taken care of in Check_Fully_Declared, called below. There
650 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
652 -- This consideration also applies to similar checks for allocators,
653 -- qualified expressions, and type conversions.
655 -- An additional exception concerns other per-object expressions that
656 -- are not directly related to component declarations, in particular
657 -- representation pragmas for tasks. These will be per-object
658 -- expressions if they depend on discriminants or some global entity.
659 -- If the task has access discriminants, the designated type may be
660 -- incomplete at the point the expression is resolved. This resolution
661 -- takes place within the body of the initialization procedure, where
662 -- the discriminant is replaced by its discriminal.
664 if Is_Entity_Name (Pref)
665 and then Ekind (Entity (Pref)) = E_In_Parameter
669 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
670 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
671 -- Analyze_Object_Renaming, and Freeze_Entity.
673 elsif Ada_Version >= Ada_2005
674 and then Is_Entity_Name (Pref)
675 and then Is_Access_Type (Etype (Pref))
676 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
678 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
682 Check_Fully_Declared (Typ, Parent (Pref));
684 end Check_Fully_Declared_Prefix;
686 ------------------------------
687 -- Check_Infinite_Recursion --
688 ------------------------------
690 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
694 function Same_Argument_List return Boolean;
695 -- Check whether list of actuals is identical to list of formals of
696 -- called function (which is also the enclosing scope).
698 ------------------------
699 -- Same_Argument_List --
700 ------------------------
702 function Same_Argument_List return Boolean is
708 if not Is_Entity_Name (Name (N)) then
711 Subp := Entity (Name (N));
714 F := First_Formal (Subp);
715 A := First_Actual (N);
716 while Present (F) and then Present (A) loop
717 if not Is_Entity_Name (A)
718 or else Entity (A) /= F
728 end Same_Argument_List;
730 -- Start of processing for Check_Infinite_Recursion
733 -- Special case, if this is a procedure call and is a call to the
734 -- current procedure with the same argument list, then this is for
735 -- sure an infinite recursion and we insert a call to raise SE.
737 if Is_List_Member (N)
738 and then List_Length (List_Containing (N)) = 1
739 and then Same_Argument_List
742 P : constant Node_Id := Parent (N);
744 if Nkind (P) = N_Handled_Sequence_Of_Statements
745 and then Nkind (Parent (P)) = N_Subprogram_Body
746 and then Is_Empty_List (Declarations (Parent (P)))
748 Error_Msg_Warn := SPARK_Mode /= On;
749 Error_Msg_N ("!infinite recursion<<", N);
750 Error_Msg_N ("\!Storage_Error [<<", N);
752 Make_Raise_Storage_Error (Sloc (N),
753 Reason => SE_Infinite_Recursion));
759 -- If not that special case, search up tree, quitting if we reach a
760 -- construct (e.g. a conditional) that tells us that this is not a
761 -- case for an infinite recursion warning.
767 -- If no parent, then we were not inside a subprogram, this can for
768 -- example happen when processing certain pragmas in a spec. Just
769 -- return False in this case.
775 -- Done if we get to subprogram body, this is definitely an infinite
776 -- recursion case if we did not find anything to stop us.
778 exit when Nkind (P) = N_Subprogram_Body;
780 -- If appearing in conditional, result is false
782 if Nkind_In (P, N_Or_Else,
791 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
792 and then C /= First (Statements (P))
794 -- If the call is the expression of a return statement and the
795 -- actuals are identical to the formals, it's worth a warning.
796 -- However, we skip this if there is an immediately preceding
797 -- raise statement, since the call is never executed.
799 -- Furthermore, this corresponds to a common idiom:
801 -- function F (L : Thing) return Boolean is
803 -- raise Program_Error;
807 -- for generating a stub function
809 if Nkind (Parent (N)) = N_Simple_Return_Statement
810 and then Same_Argument_List
812 exit when not Is_List_Member (Parent (N));
814 -- OK, return statement is in a statement list, look for raise
820 -- Skip past N_Freeze_Entity nodes generated by expansion
822 Nod := Prev (Parent (N));
824 and then Nkind (Nod) = N_Freeze_Entity
829 -- If no raise statement, give warning. We look at the
830 -- original node, because in the case of "raise ... with
831 -- ...", the node has been transformed into a call.
833 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
835 (Nkind (Nod) not in N_Raise_xxx_Error
836 or else Present (Condition (Nod)));
847 Error_Msg_Warn := SPARK_Mode /= On;
848 Error_Msg_N ("!possible infinite recursion<<", N);
849 Error_Msg_N ("\!??Storage_Error ]<<", N);
852 end Check_Infinite_Recursion;
854 -------------------------------
855 -- Check_Initialization_Call --
856 -------------------------------
858 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
859 Typ : constant Entity_Id := Etype (First_Formal (Nam));
861 function Uses_SS (T : Entity_Id) return Boolean;
862 -- Check whether the creation of an object of the type will involve
863 -- use of the secondary stack. If T is a record type, this is true
864 -- if the expression for some component uses the secondary stack, e.g.
865 -- through a call to a function that returns an unconstrained value.
866 -- False if T is controlled, because cleanups occur elsewhere.
872 function Uses_SS (T : Entity_Id) return Boolean is
875 Full_Type : Entity_Id := Underlying_Type (T);
878 -- Normally we want to use the underlying type, but if it's not set
879 -- then continue with T.
881 if not Present (Full_Type) then
885 if Is_Controlled (Full_Type) then
888 elsif Is_Array_Type (Full_Type) then
889 return Uses_SS (Component_Type (Full_Type));
891 elsif Is_Record_Type (Full_Type) then
892 Comp := First_Component (Full_Type);
893 while Present (Comp) loop
894 if Ekind (Comp) = E_Component
895 and then Nkind (Parent (Comp)) = N_Component_Declaration
897 -- The expression for a dynamic component may be rewritten
898 -- as a dereference, so retrieve original node.
900 Expr := Original_Node (Expression (Parent (Comp)));
902 -- Return True if the expression is a call to a function
903 -- (including an attribute function such as Image, or a
904 -- user-defined operator) with a result that requires a
907 if (Nkind (Expr) = N_Function_Call
908 or else Nkind (Expr) in N_Op
909 or else (Nkind (Expr) = N_Attribute_Reference
910 and then Present (Expressions (Expr))))
911 and then Requires_Transient_Scope (Etype (Expr))
915 elsif Uses_SS (Etype (Comp)) then
920 Next_Component (Comp);
930 -- Start of processing for Check_Initialization_Call
933 -- Establish a transient scope if the type needs it
935 if Uses_SS (Typ) then
936 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
938 end Check_Initialization_Call;
940 ---------------------------------------
941 -- Check_No_Direct_Boolean_Operators --
942 ---------------------------------------
944 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
946 if Scope (Entity (N)) = Standard_Standard
947 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
949 -- Restriction only applies to original source code
951 if Comes_From_Source (N) then
952 Check_Restriction (No_Direct_Boolean_Operators, N);
956 -- Do style check (but skip if in instance, error is on template)
959 if not In_Instance then
960 Check_Boolean_Operator (N);
963 end Check_No_Direct_Boolean_Operators;
965 ------------------------------
966 -- Check_Parameterless_Call --
967 ------------------------------
969 procedure Check_Parameterless_Call (N : Node_Id) is
972 function Prefix_Is_Access_Subp return Boolean;
973 -- If the prefix is of an access_to_subprogram type, the node must be
974 -- rewritten as a call. Ditto if the prefix is overloaded and all its
975 -- interpretations are access to subprograms.
977 ---------------------------
978 -- Prefix_Is_Access_Subp --
979 ---------------------------
981 function Prefix_Is_Access_Subp return Boolean is
986 -- If the context is an attribute reference that can apply to
987 -- functions, this is never a parameterless call (RM 4.1.4(6)).
989 if Nkind (Parent (N)) = N_Attribute_Reference
990 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
997 if not Is_Overloaded (N) then
999 Ekind (Etype (N)) = E_Subprogram_Type
1000 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1002 Get_First_Interp (N, I, It);
1003 while Present (It.Typ) loop
1004 if Ekind (It.Typ) /= E_Subprogram_Type
1005 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1010 Get_Next_Interp (I, It);
1015 end Prefix_Is_Access_Subp;
1017 -- Start of processing for Check_Parameterless_Call
1020 -- Defend against junk stuff if errors already detected
1022 if Total_Errors_Detected /= 0 then
1023 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1025 elsif Nkind (N) in N_Has_Chars
1026 and then Chars (N) in Error_Name_Or_No_Name
1034 -- If the context expects a value, and the name is a procedure, this is
1035 -- most likely a missing 'Access. Don't try to resolve the parameterless
1036 -- call, error will be caught when the outer call is analyzed.
1038 if Is_Entity_Name (N)
1039 and then Ekind (Entity (N)) = E_Procedure
1040 and then not Is_Overloaded (N)
1042 Nkind_In (Parent (N), N_Parameter_Association,
1044 N_Procedure_Call_Statement)
1049 -- Rewrite as call if overloadable entity that is (or could be, in the
1050 -- overloaded case) a function call. If we know for sure that the entity
1051 -- is an enumeration literal, we do not rewrite it.
1053 -- If the entity is the name of an operator, it cannot be a call because
1054 -- operators cannot have default parameters. In this case, this must be
1055 -- a string whose contents coincide with an operator name. Set the kind
1056 -- of the node appropriately.
1058 if (Is_Entity_Name (N)
1059 and then Nkind (N) /= N_Operator_Symbol
1060 and then Is_Overloadable (Entity (N))
1061 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1062 or else Is_Overloaded (N)))
1064 -- Rewrite as call if it is an explicit dereference of an expression of
1065 -- a subprogram access type, and the subprogram type is not that of a
1066 -- procedure or entry.
1069 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1071 -- Rewrite as call if it is a selected component which is a function,
1072 -- this is the case of a call to a protected function (which may be
1073 -- overloaded with other protected operations).
1076 (Nkind (N) = N_Selected_Component
1077 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1079 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1081 and then Is_Overloaded (Selector_Name (N)))))
1083 -- If one of the above three conditions is met, rewrite as call. Apply
1084 -- the rewriting only once.
1087 if Nkind (Parent (N)) /= N_Function_Call
1088 or else N /= Name (Parent (N))
1091 -- This may be a prefixed call that was not fully analyzed, e.g.
1092 -- an actual in an instance.
1094 if Ada_Version >= Ada_2005
1095 and then Nkind (N) = N_Selected_Component
1096 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1098 Analyze_Selected_Component (N);
1100 if Nkind (N) /= N_Selected_Component then
1105 Nam := New_Copy (N);
1107 -- If overloaded, overload set belongs to new copy
1109 Save_Interps (N, Nam);
1111 -- Change node to parameterless function call (note that the
1112 -- Parameter_Associations associations field is left set to Empty,
1113 -- its normal default value since there are no parameters)
1115 Change_Node (N, N_Function_Call);
1117 Set_Sloc (N, Sloc (Nam));
1121 elsif Nkind (N) = N_Parameter_Association then
1122 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1124 elsif Nkind (N) = N_Operator_Symbol then
1125 Change_Operator_Symbol_To_String_Literal (N);
1126 Set_Is_Overloaded (N, False);
1127 Set_Etype (N, Any_String);
1129 end Check_Parameterless_Call;
1131 -----------------------------
1132 -- Is_Definite_Access_Type --
1133 -----------------------------
1135 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1136 Btyp : constant Entity_Id := Base_Type (E);
1138 return Ekind (Btyp) = E_Access_Type
1139 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1140 and then Comes_From_Source (Btyp));
1141 end Is_Definite_Access_Type;
1143 ----------------------
1144 -- Is_Predefined_Op --
1145 ----------------------
1147 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1149 -- Predefined operators are intrinsic subprograms
1151 if not Is_Intrinsic_Subprogram (Nam) then
1155 -- A call to a back-end builtin is never a predefined operator
1157 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1161 return not Is_Generic_Instance (Nam)
1162 and then Chars (Nam) in Any_Operator_Name
1163 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1164 end Is_Predefined_Op;
1166 -----------------------------
1167 -- Make_Call_Into_Operator --
1168 -----------------------------
1170 procedure Make_Call_Into_Operator
1175 Op_Name : constant Name_Id := Chars (Op_Id);
1176 Act1 : Node_Id := First_Actual (N);
1177 Act2 : Node_Id := Next_Actual (Act1);
1178 Error : Boolean := False;
1179 Func : constant Entity_Id := Entity (Name (N));
1180 Is_Binary : constant Boolean := Present (Act2);
1182 Opnd_Type : Entity_Id;
1183 Orig_Type : Entity_Id := Empty;
1186 type Kind_Test is access function (E : Entity_Id) return Boolean;
1188 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1189 -- If the operand is not universal, and the operator is given by an
1190 -- expanded name, verify that the operand has an interpretation with a
1191 -- type defined in the given scope of the operator.
1193 function Type_In_P (Test : Kind_Test) return Entity_Id;
1194 -- Find a type of the given class in package Pack that contains the
1197 ---------------------------
1198 -- Operand_Type_In_Scope --
1199 ---------------------------
1201 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1202 Nod : constant Node_Id := Right_Opnd (Op_Node);
1207 if not Is_Overloaded (Nod) then
1208 return Scope (Base_Type (Etype (Nod))) = S;
1211 Get_First_Interp (Nod, I, It);
1212 while Present (It.Typ) loop
1213 if Scope (Base_Type (It.Typ)) = S then
1217 Get_Next_Interp (I, It);
1222 end Operand_Type_In_Scope;
1228 function Type_In_P (Test : Kind_Test) return Entity_Id is
1231 function In_Decl return Boolean;
1232 -- Verify that node is not part of the type declaration for the
1233 -- candidate type, which would otherwise be invisible.
1239 function In_Decl return Boolean is
1240 Decl_Node : constant Node_Id := Parent (E);
1246 if Etype (E) = Any_Type then
1249 elsif No (Decl_Node) then
1254 and then Nkind (N2) /= N_Compilation_Unit
1256 if N2 = Decl_Node then
1267 -- Start of processing for Type_In_P
1270 -- If the context type is declared in the prefix package, this is the
1271 -- desired base type.
1273 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1274 return Base_Type (Typ);
1277 E := First_Entity (Pack);
1278 while Present (E) loop
1280 and then not In_Decl
1292 -- Start of processing for Make_Call_Into_Operator
1295 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1300 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1301 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1302 Save_Interps (Act1, Left_Opnd (Op_Node));
1303 Save_Interps (Act2, Right_Opnd (Op_Node));
1304 Act1 := Left_Opnd (Op_Node);
1305 Act2 := Right_Opnd (Op_Node);
1310 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1311 Save_Interps (Act1, Right_Opnd (Op_Node));
1312 Act1 := Right_Opnd (Op_Node);
1315 -- If the operator is denoted by an expanded name, and the prefix is
1316 -- not Standard, but the operator is a predefined one whose scope is
1317 -- Standard, then this is an implicit_operator, inserted as an
1318 -- interpretation by the procedure of the same name. This procedure
1319 -- overestimates the presence of implicit operators, because it does
1320 -- not examine the type of the operands. Verify now that the operand
1321 -- type appears in the given scope. If right operand is universal,
1322 -- check the other operand. In the case of concatenation, either
1323 -- argument can be the component type, so check the type of the result.
1324 -- If both arguments are literals, look for a type of the right kind
1325 -- defined in the given scope. This elaborate nonsense is brought to
1326 -- you courtesy of b33302a. The type itself must be frozen, so we must
1327 -- find the type of the proper class in the given scope.
1329 -- A final wrinkle is the multiplication operator for fixed point types,
1330 -- which is defined in Standard only, and not in the scope of the
1331 -- fixed point type itself.
1333 if Nkind (Name (N)) = N_Expanded_Name then
1334 Pack := Entity (Prefix (Name (N)));
1336 -- If this is a package renaming, get renamed entity, which will be
1337 -- the scope of the operands if operaton is type-correct.
1339 if Present (Renamed_Entity (Pack)) then
1340 Pack := Renamed_Entity (Pack);
1343 -- If the entity being called is defined in the given package, it is
1344 -- a renaming of a predefined operator, and known to be legal.
1346 if Scope (Entity (Name (N))) = Pack
1347 and then Pack /= Standard_Standard
1351 -- Visibility does not need to be checked in an instance: if the
1352 -- operator was not visible in the generic it has been diagnosed
1353 -- already, else there is an implicit copy of it in the instance.
1355 elsif In_Instance then
1358 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1359 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1360 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1362 if Pack /= Standard_Standard then
1366 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1369 elsif Ada_Version >= Ada_2005
1370 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1371 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1376 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1378 if Op_Name = Name_Op_Concat then
1379 Opnd_Type := Base_Type (Typ);
1381 elsif (Scope (Opnd_Type) = Standard_Standard
1383 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1385 and then not Comes_From_Source (Opnd_Type))
1387 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1390 if Scope (Opnd_Type) = Standard_Standard then
1392 -- Verify that the scope contains a type that corresponds to
1393 -- the given literal. Optimize the case where Pack is Standard.
1395 if Pack /= Standard_Standard then
1397 if Opnd_Type = Universal_Integer then
1398 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1400 elsif Opnd_Type = Universal_Real then
1401 Orig_Type := Type_In_P (Is_Real_Type'Access);
1403 elsif Opnd_Type = Any_String then
1404 Orig_Type := Type_In_P (Is_String_Type'Access);
1406 elsif Opnd_Type = Any_Access then
1407 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1409 elsif Opnd_Type = Any_Composite then
1410 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1412 if Present (Orig_Type) then
1413 if Has_Private_Component (Orig_Type) then
1416 Set_Etype (Act1, Orig_Type);
1419 Set_Etype (Act2, Orig_Type);
1428 Error := No (Orig_Type);
1431 elsif Ekind (Opnd_Type) = E_Allocator_Type
1432 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1436 -- If the type is defined elsewhere, and the operator is not
1437 -- defined in the given scope (by a renaming declaration, e.g.)
1438 -- then this is an error as well. If an extension of System is
1439 -- present, and the type may be defined there, Pack must be
1442 elsif Scope (Opnd_Type) /= Pack
1443 and then Scope (Op_Id) /= Pack
1444 and then (No (System_Aux_Id)
1445 or else Scope (Opnd_Type) /= System_Aux_Id
1446 or else Pack /= Scope (System_Aux_Id))
1448 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1451 Error := not Operand_Type_In_Scope (Pack);
1454 elsif Pack = Standard_Standard
1455 and then not Operand_Type_In_Scope (Standard_Standard)
1462 Error_Msg_Node_2 := Pack;
1464 ("& not declared in&", N, Selector_Name (Name (N)));
1465 Set_Etype (N, Any_Type);
1468 -- Detect a mismatch between the context type and the result type
1469 -- in the named package, which is otherwise not detected if the
1470 -- operands are universal. Check is only needed if source entity is
1471 -- an operator, not a function that renames an operator.
1473 elsif Nkind (Parent (N)) /= N_Type_Conversion
1474 and then Ekind (Entity (Name (N))) = E_Operator
1475 and then Is_Numeric_Type (Typ)
1476 and then not Is_Universal_Numeric_Type (Typ)
1477 and then Scope (Base_Type (Typ)) /= Pack
1478 and then not In_Instance
1480 if Is_Fixed_Point_Type (Typ)
1481 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1483 -- Already checked above
1487 -- Operator may be defined in an extension of System
1489 elsif Present (System_Aux_Id)
1490 and then Scope (Opnd_Type) = System_Aux_Id
1495 -- Could we use Wrong_Type here??? (this would require setting
1496 -- Etype (N) to the actual type found where Typ was expected).
1498 Error_Msg_NE ("expect }", N, Typ);
1503 Set_Chars (Op_Node, Op_Name);
1505 if not Is_Private_Type (Etype (N)) then
1506 Set_Etype (Op_Node, Base_Type (Etype (N)));
1508 Set_Etype (Op_Node, Etype (N));
1511 -- If this is a call to a function that renames a predefined equality,
1512 -- the renaming declaration provides a type that must be used to
1513 -- resolve the operands. This must be done now because resolution of
1514 -- the equality node will not resolve any remaining ambiguity, and it
1515 -- assumes that the first operand is not overloaded.
1517 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1518 and then Ekind (Func) = E_Function
1519 and then Is_Overloaded (Act1)
1521 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1522 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1525 Set_Entity (Op_Node, Op_Id);
1526 Generate_Reference (Op_Id, N, ' ');
1528 -- Do rewrite setting Comes_From_Source on the result if the original
1529 -- call came from source. Although it is not strictly the case that the
1530 -- operator as such comes from the source, logically it corresponds
1531 -- exactly to the function call in the source, so it should be marked
1532 -- this way (e.g. to make sure that validity checks work fine).
1535 CS : constant Boolean := Comes_From_Source (N);
1537 Rewrite (N, Op_Node);
1538 Set_Comes_From_Source (N, CS);
1541 -- If this is an arithmetic operator and the result type is private,
1542 -- the operands and the result must be wrapped in conversion to
1543 -- expose the underlying numeric type and expand the proper checks,
1544 -- e.g. on division.
1546 if Is_Private_Type (Typ) then
1548 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1549 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1550 Resolve_Intrinsic_Operator (N, Typ);
1552 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1553 Resolve_Intrinsic_Unary_Operator (N, Typ);
1562 -- If in ASIS_Mode, propagate operand types to original actuals of
1563 -- function call, which would otherwise not be fully resolved. If
1564 -- the call has already been constant-folded, nothing to do. We
1565 -- relocate the operand nodes rather than copy them, to preserve
1566 -- original_node pointers, given that the operands themselves may
1567 -- have been rewritten.
1569 if ASIS_Mode and then Nkind (N) in N_Op then
1571 Rewrite (First (Parameter_Associations (Original_Node (N))),
1572 Relocate_Node (Left_Opnd (N)));
1573 Rewrite (Next (First (Parameter_Associations (Original_Node (N)))),
1574 Relocate_Node (Right_Opnd (N)));
1576 Rewrite (First (Parameter_Associations (Original_Node (N))),
1577 Relocate_Node (Right_Opnd (N)));
1580 Set_Parent (Original_Node (N), Parent (N));
1582 end Make_Call_Into_Operator;
1588 function Operator_Kind
1590 Is_Binary : Boolean) return Node_Kind
1595 -- Use CASE statement or array???
1598 if Op_Name = Name_Op_And then
1600 elsif Op_Name = Name_Op_Or then
1602 elsif Op_Name = Name_Op_Xor then
1604 elsif Op_Name = Name_Op_Eq then
1606 elsif Op_Name = Name_Op_Ne then
1608 elsif Op_Name = Name_Op_Lt then
1610 elsif Op_Name = Name_Op_Le then
1612 elsif Op_Name = Name_Op_Gt then
1614 elsif Op_Name = Name_Op_Ge then
1616 elsif Op_Name = Name_Op_Add then
1618 elsif Op_Name = Name_Op_Subtract then
1619 Kind := N_Op_Subtract;
1620 elsif Op_Name = Name_Op_Concat then
1621 Kind := N_Op_Concat;
1622 elsif Op_Name = Name_Op_Multiply then
1623 Kind := N_Op_Multiply;
1624 elsif Op_Name = Name_Op_Divide then
1625 Kind := N_Op_Divide;
1626 elsif Op_Name = Name_Op_Mod then
1628 elsif Op_Name = Name_Op_Rem then
1630 elsif Op_Name = Name_Op_Expon then
1633 raise Program_Error;
1639 if Op_Name = Name_Op_Add then
1641 elsif Op_Name = Name_Op_Subtract then
1643 elsif Op_Name = Name_Op_Abs then
1645 elsif Op_Name = Name_Op_Not then
1648 raise Program_Error;
1655 ----------------------------
1656 -- Preanalyze_And_Resolve --
1657 ----------------------------
1659 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1660 Save_Full_Analysis : constant Boolean := Full_Analysis;
1663 Full_Analysis := False;
1664 Expander_Mode_Save_And_Set (False);
1666 -- Normally, we suppress all checks for this preanalysis. There is no
1667 -- point in processing them now, since they will be applied properly
1668 -- and in the proper location when the default expressions reanalyzed
1669 -- and reexpanded later on. We will also have more information at that
1670 -- point for possible suppression of individual checks.
1672 -- However, in SPARK mode, most expansion is suppressed, and this
1673 -- later reanalysis and reexpansion may not occur. SPARK mode does
1674 -- require the setting of checking flags for proof purposes, so we
1675 -- do the SPARK preanalysis without suppressing checks.
1677 -- This special handling for SPARK mode is required for example in the
1678 -- case of Ada 2012 constructs such as quantified expressions, which are
1679 -- expanded in two separate steps.
1681 if GNATprove_Mode then
1682 Analyze_And_Resolve (N, T);
1684 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1687 Expander_Mode_Restore;
1688 Full_Analysis := Save_Full_Analysis;
1689 end Preanalyze_And_Resolve;
1691 -- Version without context type
1693 procedure Preanalyze_And_Resolve (N : Node_Id) is
1694 Save_Full_Analysis : constant Boolean := Full_Analysis;
1697 Full_Analysis := False;
1698 Expander_Mode_Save_And_Set (False);
1701 Resolve (N, Etype (N), Suppress => All_Checks);
1703 Expander_Mode_Restore;
1704 Full_Analysis := Save_Full_Analysis;
1705 end Preanalyze_And_Resolve;
1707 ----------------------------------
1708 -- Replace_Actual_Discriminants --
1709 ----------------------------------
1711 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1712 Loc : constant Source_Ptr := Sloc (N);
1713 Tsk : Node_Id := Empty;
1715 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1716 -- Comment needed???
1722 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1726 if Nkind (Nod) = N_Identifier then
1727 Ent := Entity (Nod);
1730 and then Ekind (Ent) = E_Discriminant
1733 Make_Selected_Component (Loc,
1734 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1735 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1737 Set_Etype (Nod, Etype (Ent));
1745 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1747 -- Start of processing for Replace_Actual_Discriminants
1750 if not Expander_Active then
1754 if Nkind (Name (N)) = N_Selected_Component then
1755 Tsk := Prefix (Name (N));
1757 elsif Nkind (Name (N)) = N_Indexed_Component then
1758 Tsk := Prefix (Prefix (Name (N)));
1764 Replace_Discrs (Default);
1766 end Replace_Actual_Discriminants;
1772 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1773 Ambiguous : Boolean := False;
1774 Ctx_Type : Entity_Id := Typ;
1775 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1776 Err_Type : Entity_Id := Empty;
1777 Found : Boolean := False;
1780 I1 : Interp_Index := 0; -- prevent junk warning
1783 Seen : Entity_Id := Empty; -- prevent junk warning
1785 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1786 -- Determine whether a node comes from a predefined library unit or
1789 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1790 -- Try and fix up a literal so that it matches its expected type. New
1791 -- literals are manufactured if necessary to avoid cascaded errors.
1793 procedure Report_Ambiguous_Argument;
1794 -- Additional diagnostics when an ambiguous call has an ambiguous
1795 -- argument (typically a controlling actual).
1797 procedure Resolution_Failed;
1798 -- Called when attempt at resolving current expression fails
1800 ------------------------------------
1801 -- Comes_From_Predefined_Lib_Unit --
1802 -------------------------------------
1804 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1807 Sloc (Nod) = Standard_Location
1808 or else Is_Predefined_File_Name
1809 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1810 end Comes_From_Predefined_Lib_Unit;
1812 --------------------
1813 -- Patch_Up_Value --
1814 --------------------
1816 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1818 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1820 Make_Real_Literal (Sloc (N),
1821 Realval => UR_From_Uint (Intval (N))));
1822 Set_Etype (N, Universal_Real);
1823 Set_Is_Static_Expression (N);
1825 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1827 Make_Integer_Literal (Sloc (N),
1828 Intval => UR_To_Uint (Realval (N))));
1829 Set_Etype (N, Universal_Integer);
1830 Set_Is_Static_Expression (N);
1832 elsif Nkind (N) = N_String_Literal
1833 and then Is_Character_Type (Typ)
1835 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1837 Make_Character_Literal (Sloc (N),
1839 Char_Literal_Value =>
1840 UI_From_Int (Character'Pos ('A'))));
1841 Set_Etype (N, Any_Character);
1842 Set_Is_Static_Expression (N);
1844 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1846 Make_String_Literal (Sloc (N),
1847 Strval => End_String));
1849 elsif Nkind (N) = N_Range then
1850 Patch_Up_Value (Low_Bound (N), Typ);
1851 Patch_Up_Value (High_Bound (N), Typ);
1855 -------------------------------
1856 -- Report_Ambiguous_Argument --
1857 -------------------------------
1859 procedure Report_Ambiguous_Argument is
1860 Arg : constant Node_Id := First (Parameter_Associations (N));
1865 if Nkind (Arg) = N_Function_Call
1866 and then Is_Entity_Name (Name (Arg))
1867 and then Is_Overloaded (Name (Arg))
1869 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1871 -- Could use comments on what is going on here???
1873 Get_First_Interp (Name (Arg), I, It);
1874 while Present (It.Nam) loop
1875 Error_Msg_Sloc := Sloc (It.Nam);
1877 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1878 Error_Msg_N ("interpretation (inherited) #!", Arg);
1880 Error_Msg_N ("interpretation #!", Arg);
1883 Get_Next_Interp (I, It);
1886 end Report_Ambiguous_Argument;
1888 -----------------------
1889 -- Resolution_Failed --
1890 -----------------------
1892 procedure Resolution_Failed is
1894 Patch_Up_Value (N, Typ);
1896 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1897 Set_Is_Overloaded (N, False);
1899 -- The caller will return without calling the expander, so we need
1900 -- to set the analyzed flag. Note that it is fine to set Analyzed
1901 -- to True even if we are in the middle of a shallow analysis,
1902 -- (see the spec of sem for more details) since this is an error
1903 -- situation anyway, and there is no point in repeating the
1904 -- analysis later (indeed it won't work to repeat it later, since
1905 -- we haven't got a clear resolution of which entity is being
1908 Set_Analyzed (N, True);
1910 end Resolution_Failed;
1912 -- Start of processing for Resolve
1919 -- Access attribute on remote subprogram cannot be used for a non-remote
1920 -- access-to-subprogram type.
1922 if Nkind (N) = N_Attribute_Reference
1923 and then Nam_In (Attribute_Name (N), Name_Access,
1924 Name_Unrestricted_Access,
1925 Name_Unchecked_Access)
1926 and then Comes_From_Source (N)
1927 and then Is_Entity_Name (Prefix (N))
1928 and then Is_Subprogram (Entity (Prefix (N)))
1929 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1930 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1933 ("prefix must statically denote a non-remote subprogram", N);
1936 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1938 -- If the context is a Remote_Access_To_Subprogram, access attributes
1939 -- must be resolved with the corresponding fat pointer. There is no need
1940 -- to check for the attribute name since the return type of an
1941 -- attribute is never a remote type.
1943 if Nkind (N) = N_Attribute_Reference
1944 and then Comes_From_Source (N)
1945 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
1948 Attr : constant Attribute_Id :=
1949 Get_Attribute_Id (Attribute_Name (N));
1950 Pref : constant Node_Id := Prefix (N);
1953 Is_Remote : Boolean := True;
1956 -- Check that Typ is a remote access-to-subprogram type
1958 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1960 -- Prefix (N) must statically denote a remote subprogram
1961 -- declared in a package specification.
1963 if Attr = Attribute_Access or else
1964 Attr = Attribute_Unchecked_Access or else
1965 Attr = Attribute_Unrestricted_Access
1967 Decl := Unit_Declaration_Node (Entity (Pref));
1969 if Nkind (Decl) = N_Subprogram_Body then
1970 Spec := Corresponding_Spec (Decl);
1972 if not No (Spec) then
1973 Decl := Unit_Declaration_Node (Spec);
1977 Spec := Parent (Decl);
1979 if not Is_Entity_Name (Prefix (N))
1980 or else Nkind (Spec) /= N_Package_Specification
1982 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1986 ("prefix must statically denote a remote subprogram ",
1990 -- If we are generating code in distributed mode, perform
1991 -- semantic checks against corresponding remote entities.
1994 and then Get_PCS_Name /= Name_No_DSA
1996 Check_Subtype_Conformant
1997 (New_Id => Entity (Prefix (N)),
1998 Old_Id => Designated_Type
1999 (Corresponding_Remote_Type (Typ)),
2003 Process_Remote_AST_Attribute (N, Typ);
2011 Debug_A_Entry ("resolving ", N);
2013 if Debug_Flag_V then
2014 Write_Overloads (N);
2017 if Comes_From_Source (N) then
2018 if Is_Fixed_Point_Type (Typ) then
2019 Check_Restriction (No_Fixed_Point, N);
2021 elsif Is_Floating_Point_Type (Typ)
2022 and then Typ /= Universal_Real
2023 and then Typ /= Any_Real
2025 Check_Restriction (No_Floating_Point, N);
2029 -- Return if already analyzed
2031 if Analyzed (N) then
2032 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2033 Analyze_Dimension (N);
2036 -- Any case of Any_Type as the Etype value means that we had a
2039 elsif Etype (N) = Any_Type then
2040 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2044 Check_Parameterless_Call (N);
2046 -- The resolution of an Expression_With_Actions is determined by
2049 if Nkind (N) = N_Expression_With_Actions then
2050 Resolve (Expression (N), Typ);
2053 Expr_Type := Etype (Expression (N));
2055 -- If not overloaded, then we know the type, and all that needs doing
2056 -- is to check that this type is compatible with the context.
2058 elsif not Is_Overloaded (N) then
2059 Found := Covers (Typ, Etype (N));
2060 Expr_Type := Etype (N);
2062 -- In the overloaded case, we must select the interpretation that
2063 -- is compatible with the context (i.e. the type passed to Resolve)
2066 -- Loop through possible interpretations
2068 Get_First_Interp (N, I, It);
2069 Interp_Loop : while Present (It.Typ) loop
2071 if Debug_Flag_V then
2072 Write_Str ("Interp: ");
2076 -- We are only interested in interpretations that are compatible
2077 -- with the expected type, any other interpretations are ignored.
2079 if not Covers (Typ, It.Typ) then
2080 if Debug_Flag_V then
2081 Write_Str (" interpretation incompatible with context");
2086 -- Skip the current interpretation if it is disabled by an
2087 -- abstract operator. This action is performed only when the
2088 -- type against which we are resolving is the same as the
2089 -- type of the interpretation.
2091 if Ada_Version >= Ada_2005
2092 and then It.Typ = Typ
2093 and then Typ /= Universal_Integer
2094 and then Typ /= Universal_Real
2095 and then Present (It.Abstract_Op)
2097 if Debug_Flag_V then
2098 Write_Line ("Skip.");
2104 -- First matching interpretation
2110 Expr_Type := It.Typ;
2112 -- Matching interpretation that is not the first, maybe an
2113 -- error, but there are some cases where preference rules are
2114 -- used to choose between the two possibilities. These and
2115 -- some more obscure cases are handled in Disambiguate.
2118 -- If the current statement is part of a predefined library
2119 -- unit, then all interpretations which come from user level
2120 -- packages should not be considered. Check previous and
2124 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2127 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2129 -- Previous interpretation must be discarded
2133 Expr_Type := It.Typ;
2134 Set_Entity (N, Seen);
2139 -- Otherwise apply further disambiguation steps
2141 Error_Msg_Sloc := Sloc (Seen);
2142 It1 := Disambiguate (N, I1, I, Typ);
2144 -- Disambiguation has succeeded. Skip the remaining
2147 if It1 /= No_Interp then
2149 Expr_Type := It1.Typ;
2151 while Present (It.Typ) loop
2152 Get_Next_Interp (I, It);
2156 -- Before we issue an ambiguity complaint, check for
2157 -- the case of a subprogram call where at least one
2158 -- of the arguments is Any_Type, and if so, suppress
2159 -- the message, since it is a cascaded error.
2161 if Nkind (N) in N_Subprogram_Call then
2167 A := First_Actual (N);
2168 while Present (A) loop
2171 if Nkind (E) = N_Parameter_Association then
2172 E := Explicit_Actual_Parameter (E);
2175 if Etype (E) = Any_Type then
2176 if Debug_Flag_V then
2177 Write_Str ("Any_Type in call");
2188 elsif Nkind (N) in N_Binary_Op
2189 and then (Etype (Left_Opnd (N)) = Any_Type
2190 or else Etype (Right_Opnd (N)) = Any_Type)
2194 elsif Nkind (N) in N_Unary_Op
2195 and then Etype (Right_Opnd (N)) = Any_Type
2200 -- Not that special case, so issue message using the
2201 -- flag Ambiguous to control printing of the header
2202 -- message only at the start of an ambiguous set.
2204 if not Ambiguous then
2205 if Nkind (N) = N_Function_Call
2206 and then Nkind (Name (N)) = N_Explicit_Dereference
2209 ("ambiguous expression "
2210 & "(cannot resolve indirect call)!", N);
2212 Error_Msg_NE -- CODEFIX
2213 ("ambiguous expression (cannot resolve&)!",
2219 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2221 ("\\possible interpretation (inherited)#!", N);
2223 Error_Msg_N -- CODEFIX
2224 ("\\possible interpretation#!", N);
2227 if Nkind (N) in N_Subprogram_Call
2228 and then Present (Parameter_Associations (N))
2230 Report_Ambiguous_Argument;
2234 Error_Msg_Sloc := Sloc (It.Nam);
2236 -- By default, the error message refers to the candidate
2237 -- interpretation. But if it is a predefined operator, it
2238 -- is implicitly declared at the declaration of the type
2239 -- of the operand. Recover the sloc of that declaration
2240 -- for the error message.
2242 if Nkind (N) in N_Op
2243 and then Scope (It.Nam) = Standard_Standard
2244 and then not Is_Overloaded (Right_Opnd (N))
2245 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2248 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2250 if Comes_From_Source (Err_Type)
2251 and then Present (Parent (Err_Type))
2253 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2256 elsif Nkind (N) in N_Binary_Op
2257 and then Scope (It.Nam) = Standard_Standard
2258 and then not Is_Overloaded (Left_Opnd (N))
2259 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2262 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2264 if Comes_From_Source (Err_Type)
2265 and then Present (Parent (Err_Type))
2267 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2270 -- If this is an indirect call, use the subprogram_type
2271 -- in the message, to have a meaningful location. Also
2272 -- indicate if this is an inherited operation, created
2273 -- by a type declaration.
2275 elsif Nkind (N) = N_Function_Call
2276 and then Nkind (Name (N)) = N_Explicit_Dereference
2277 and then Is_Type (It.Nam)
2281 Sloc (Associated_Node_For_Itype (Err_Type));
2286 if Nkind (N) in N_Op
2287 and then Scope (It.Nam) = Standard_Standard
2288 and then Present (Err_Type)
2290 -- Special-case the message for universal_fixed
2291 -- operators, which are not declared with the type
2292 -- of the operand, but appear forever in Standard.
2294 if It.Typ = Universal_Fixed
2295 and then Scope (It.Nam) = Standard_Standard
2298 ("\\possible interpretation as universal_fixed "
2299 & "operation (RM 4.5.5 (19))", N);
2302 ("\\possible interpretation (predefined)#!", N);
2306 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2309 ("\\possible interpretation (inherited)#!", N);
2311 Error_Msg_N -- CODEFIX
2312 ("\\possible interpretation#!", N);
2318 -- We have a matching interpretation, Expr_Type is the type
2319 -- from this interpretation, and Seen is the entity.
2321 -- For an operator, just set the entity name. The type will be
2322 -- set by the specific operator resolution routine.
2324 if Nkind (N) in N_Op then
2325 Set_Entity (N, Seen);
2326 Generate_Reference (Seen, N);
2328 elsif Nkind (N) = N_Case_Expression then
2329 Set_Etype (N, Expr_Type);
2331 elsif Nkind (N) = N_Character_Literal then
2332 Set_Etype (N, Expr_Type);
2334 elsif Nkind (N) = N_If_Expression then
2335 Set_Etype (N, Expr_Type);
2337 -- AI05-0139-2: Expression is overloaded because type has
2338 -- implicit dereference. If type matches context, no implicit
2339 -- dereference is involved.
2341 elsif Has_Implicit_Dereference (Expr_Type) then
2342 Set_Etype (N, Expr_Type);
2343 Set_Is_Overloaded (N, False);
2346 elsif Is_Overloaded (N)
2347 and then Present (It.Nam)
2348 and then Ekind (It.Nam) = E_Discriminant
2349 and then Has_Implicit_Dereference (It.Nam)
2351 -- If the node is a general indexing, the dereference is
2352 -- is inserted when resolving the rewritten form, else
2355 if Nkind (N) /= N_Indexed_Component
2356 or else No (Generalized_Indexing (N))
2358 Build_Explicit_Dereference (N, It.Nam);
2361 -- For an explicit dereference, attribute reference, range,
2362 -- short-circuit form (which is not an operator node), or call
2363 -- with a name that is an explicit dereference, there is
2364 -- nothing to be done at this point.
2366 elsif Nkind_In (N, N_Explicit_Dereference,
2367 N_Attribute_Reference,
2369 N_Indexed_Component,
2372 N_Selected_Component,
2374 or else Nkind (Name (N)) = N_Explicit_Dereference
2378 -- For procedure or function calls, set the type of the name,
2379 -- and also the entity pointer for the prefix.
2381 elsif Nkind (N) in N_Subprogram_Call
2382 and then Is_Entity_Name (Name (N))
2384 Set_Etype (Name (N), Expr_Type);
2385 Set_Entity (Name (N), Seen);
2386 Generate_Reference (Seen, Name (N));
2388 elsif Nkind (N) = N_Function_Call
2389 and then Nkind (Name (N)) = N_Selected_Component
2391 Set_Etype (Name (N), Expr_Type);
2392 Set_Entity (Selector_Name (Name (N)), Seen);
2393 Generate_Reference (Seen, Selector_Name (Name (N)));
2395 -- For all other cases, just set the type of the Name
2398 Set_Etype (Name (N), Expr_Type);
2405 -- Move to next interpretation
2407 exit Interp_Loop when No (It.Typ);
2409 Get_Next_Interp (I, It);
2410 end loop Interp_Loop;
2413 -- At this stage Found indicates whether or not an acceptable
2414 -- interpretation exists. If not, then we have an error, except that if
2415 -- the context is Any_Type as a result of some other error, then we
2416 -- suppress the error report.
2419 if Typ /= Any_Type then
2421 -- If type we are looking for is Void, then this is the procedure
2422 -- call case, and the error is simply that what we gave is not a
2423 -- procedure name (we think of procedure calls as expressions with
2424 -- types internally, but the user doesn't think of them this way).
2426 if Typ = Standard_Void_Type then
2428 -- Special case message if function used as a procedure
2430 if Nkind (N) = N_Procedure_Call_Statement
2431 and then Is_Entity_Name (Name (N))
2432 and then Ekind (Entity (Name (N))) = E_Function
2435 ("cannot use function & in a procedure call",
2436 Name (N), Entity (Name (N)));
2438 -- Otherwise give general message (not clear what cases this
2439 -- covers, but no harm in providing for them).
2442 Error_Msg_N ("expect procedure name in procedure call", N);
2447 -- Otherwise we do have a subexpression with the wrong type
2449 -- Check for the case of an allocator which uses an access type
2450 -- instead of the designated type. This is a common error and we
2451 -- specialize the message, posting an error on the operand of the
2452 -- allocator, complaining that we expected the designated type of
2455 elsif Nkind (N) = N_Allocator
2456 and then Is_Access_Type (Typ)
2457 and then Is_Access_Type (Etype (N))
2458 and then Designated_Type (Etype (N)) = Typ
2460 Wrong_Type (Expression (N), Designated_Type (Typ));
2463 -- Check for view mismatch on Null in instances, for which the
2464 -- view-swapping mechanism has no identifier.
2466 elsif (In_Instance or else In_Inlined_Body)
2467 and then (Nkind (N) = N_Null)
2468 and then Is_Private_Type (Typ)
2469 and then Is_Access_Type (Full_View (Typ))
2471 Resolve (N, Full_View (Typ));
2475 -- Check for an aggregate. Sometimes we can get bogus aggregates
2476 -- from misuse of parentheses, and we are about to complain about
2477 -- the aggregate without even looking inside it.
2479 -- Instead, if we have an aggregate of type Any_Composite, then
2480 -- analyze and resolve the component fields, and then only issue
2481 -- another message if we get no errors doing this (otherwise
2482 -- assume that the errors in the aggregate caused the problem).
2484 elsif Nkind (N) = N_Aggregate
2485 and then Etype (N) = Any_Composite
2487 -- Disable expansion in any case. If there is a type mismatch
2488 -- it may be fatal to try to expand the aggregate. The flag
2489 -- would otherwise be set to false when the error is posted.
2491 Expander_Active := False;
2494 procedure Check_Aggr (Aggr : Node_Id);
2495 -- Check one aggregate, and set Found to True if we have a
2496 -- definite error in any of its elements
2498 procedure Check_Elmt (Aelmt : Node_Id);
2499 -- Check one element of aggregate and set Found to True if
2500 -- we definitely have an error in the element.
2506 procedure Check_Aggr (Aggr : Node_Id) is
2510 if Present (Expressions (Aggr)) then
2511 Elmt := First (Expressions (Aggr));
2512 while Present (Elmt) loop
2518 if Present (Component_Associations (Aggr)) then
2519 Elmt := First (Component_Associations (Aggr));
2520 while Present (Elmt) loop
2522 -- If this is a default-initialized component, then
2523 -- there is nothing to check. The box will be
2524 -- replaced by the appropriate call during late
2527 if not Box_Present (Elmt) then
2528 Check_Elmt (Expression (Elmt));
2540 procedure Check_Elmt (Aelmt : Node_Id) is
2542 -- If we have a nested aggregate, go inside it (to
2543 -- attempt a naked analyze-resolve of the aggregate can
2544 -- cause undesirable cascaded errors). Do not resolve
2545 -- expression if it needs a type from context, as for
2546 -- integer * fixed expression.
2548 if Nkind (Aelmt) = N_Aggregate then
2554 if not Is_Overloaded (Aelmt)
2555 and then Etype (Aelmt) /= Any_Fixed
2560 if Etype (Aelmt) = Any_Type then
2571 -- Looks like we have a type error, but check for special case
2572 -- of Address wanted, integer found, with the configuration pragma
2573 -- Allow_Integer_Address active. If we have this case, introduce
2574 -- an unchecked conversion to allow the integer expression to be
2575 -- treated as an Address. The reverse case of integer wanted,
2576 -- Address found, is treated in an analogous manner.
2578 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2579 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2580 Analyze_And_Resolve (N, Typ);
2584 -- That special Allow_Integer_Address check did not appply, so we
2585 -- have a real type error. If an error message was issued already,
2586 -- Found got reset to True, so if it's still False, issue standard
2587 -- Wrong_Type message.
2590 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2592 Subp_Name : Node_Id;
2595 if Is_Entity_Name (Name (N)) then
2596 Subp_Name := Name (N);
2598 elsif Nkind (Name (N)) = N_Selected_Component then
2600 -- Protected operation: retrieve operation name
2602 Subp_Name := Selector_Name (Name (N));
2605 raise Program_Error;
2608 Error_Msg_Node_2 := Typ;
2610 ("no visible interpretation of& "
2611 & "matches expected type&", N, Subp_Name);
2614 if All_Errors_Mode then
2616 Index : Interp_Index;
2620 Error_Msg_N ("\\possible interpretations:", N);
2622 Get_First_Interp (Name (N), Index, It);
2623 while Present (It.Nam) loop
2624 Error_Msg_Sloc := Sloc (It.Nam);
2625 Error_Msg_Node_2 := It.Nam;
2627 ("\\ type& for & declared#", N, It.Typ);
2628 Get_Next_Interp (Index, It);
2633 Error_Msg_N ("\use -gnatf for details", N);
2637 Wrong_Type (N, Typ);
2645 -- Test if we have more than one interpretation for the context
2647 elsif Ambiguous then
2651 -- Only one intepretation
2654 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2655 -- the "+" on T is abstract, and the operands are of universal type,
2656 -- the above code will have (incorrectly) resolved the "+" to the
2657 -- universal one in Standard. Therefore check for this case and give
2658 -- an error. We can't do this earlier, because it would cause legal
2659 -- cases to get errors (when some other type has an abstract "+").
2661 if Ada_Version >= Ada_2005
2662 and then Nkind (N) in N_Op
2663 and then Is_Overloaded (N)
2664 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2666 Get_First_Interp (N, I, It);
2667 while Present (It.Typ) loop
2668 if Present (It.Abstract_Op) and then
2669 Etype (It.Abstract_Op) = Typ
2672 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2676 Get_Next_Interp (I, It);
2680 -- Here we have an acceptable interpretation for the context
2682 -- Propagate type information and normalize tree for various
2683 -- predefined operations. If the context only imposes a class of
2684 -- types, rather than a specific type, propagate the actual type
2687 if Typ = Any_Integer or else
2688 Typ = Any_Boolean or else
2689 Typ = Any_Modular or else
2690 Typ = Any_Real or else
2693 Ctx_Type := Expr_Type;
2695 -- Any_Fixed is legal in a real context only if a specific fixed-
2696 -- point type is imposed. If Norman Cohen can be confused by this,
2697 -- it deserves a separate message.
2700 and then Expr_Type = Any_Fixed
2702 Error_Msg_N ("illegal context for mixed mode operation", N);
2703 Set_Etype (N, Universal_Real);
2704 Ctx_Type := Universal_Real;
2708 -- A user-defined operator is transformed into a function call at
2709 -- this point, so that further processing knows that operators are
2710 -- really operators (i.e. are predefined operators). User-defined
2711 -- operators that are intrinsic are just renamings of the predefined
2712 -- ones, and need not be turned into calls either, but if they rename
2713 -- a different operator, we must transform the node accordingly.
2714 -- Instantiations of Unchecked_Conversion are intrinsic but are
2715 -- treated as functions, even if given an operator designator.
2717 if Nkind (N) in N_Op
2718 and then Present (Entity (N))
2719 and then Ekind (Entity (N)) /= E_Operator
2722 if not Is_Predefined_Op (Entity (N)) then
2723 Rewrite_Operator_As_Call (N, Entity (N));
2725 elsif Present (Alias (Entity (N)))
2727 Nkind (Parent (Parent (Entity (N)))) =
2728 N_Subprogram_Renaming_Declaration
2730 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2732 -- If the node is rewritten, it will be fully resolved in
2733 -- Rewrite_Renamed_Operator.
2735 if Analyzed (N) then
2741 case N_Subexpr'(Nkind (N)) is
2743 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2745 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2747 when N_Short_Circuit
2748 => Resolve_Short_Circuit (N, Ctx_Type);
2750 when N_Attribute_Reference
2751 => Resolve_Attribute (N, Ctx_Type);
2753 when N_Case_Expression
2754 => Resolve_Case_Expression (N, Ctx_Type);
2756 when N_Character_Literal
2757 => Resolve_Character_Literal (N, Ctx_Type);
2759 when N_Expanded_Name
2760 => Resolve_Entity_Name (N, Ctx_Type);
2762 when N_Explicit_Dereference
2763 => Resolve_Explicit_Dereference (N, Ctx_Type);
2765 when N_Expression_With_Actions
2766 => Resolve_Expression_With_Actions (N, Ctx_Type);
2768 when N_Extension_Aggregate
2769 => Resolve_Extension_Aggregate (N, Ctx_Type);
2771 when N_Function_Call
2772 => Resolve_Call (N, Ctx_Type);
2775 => Resolve_Entity_Name (N, Ctx_Type);
2777 when N_If_Expression
2778 => Resolve_If_Expression (N, Ctx_Type);
2780 when N_Indexed_Component
2781 => Resolve_Indexed_Component (N, Ctx_Type);
2783 when N_Integer_Literal
2784 => Resolve_Integer_Literal (N, Ctx_Type);
2786 when N_Membership_Test
2787 => Resolve_Membership_Op (N, Ctx_Type);
2789 when N_Null => Resolve_Null (N, Ctx_Type);
2791 when N_Op_And | N_Op_Or | N_Op_Xor
2792 => Resolve_Logical_Op (N, Ctx_Type);
2794 when N_Op_Eq | N_Op_Ne
2795 => Resolve_Equality_Op (N, Ctx_Type);
2797 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2798 => Resolve_Comparison_Op (N, Ctx_Type);
2800 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2802 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2803 N_Op_Divide | N_Op_Mod | N_Op_Rem
2805 => Resolve_Arithmetic_Op (N, Ctx_Type);
2807 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2809 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2811 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2812 => Resolve_Unary_Op (N, Ctx_Type);
2814 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2816 when N_Procedure_Call_Statement
2817 => Resolve_Call (N, Ctx_Type);
2819 when N_Operator_Symbol
2820 => Resolve_Operator_Symbol (N, Ctx_Type);
2822 when N_Qualified_Expression
2823 => Resolve_Qualified_Expression (N, Ctx_Type);
2825 -- Why is the following null, needs a comment ???
2827 when N_Quantified_Expression
2830 when N_Raise_Expression
2831 => Resolve_Raise_Expression (N, Ctx_Type);
2833 when N_Raise_xxx_Error
2834 => Set_Etype (N, Ctx_Type);
2836 when N_Range => Resolve_Range (N, Ctx_Type);
2839 => Resolve_Real_Literal (N, Ctx_Type);
2841 when N_Reference => Resolve_Reference (N, Ctx_Type);
2843 when N_Selected_Component
2844 => Resolve_Selected_Component (N, Ctx_Type);
2846 when N_Slice => Resolve_Slice (N, Ctx_Type);
2848 when N_String_Literal
2849 => Resolve_String_Literal (N, Ctx_Type);
2851 when N_Type_Conversion
2852 => Resolve_Type_Conversion (N, Ctx_Type);
2854 when N_Unchecked_Expression =>
2855 Resolve_Unchecked_Expression (N, Ctx_Type);
2857 when N_Unchecked_Type_Conversion =>
2858 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2861 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2862 -- expression of an anonymous access type that occurs in the context
2863 -- of a named general access type, except when the expression is that
2864 -- of a membership test. This ensures proper legality checking in
2865 -- terms of allowed conversions (expressions that would be illegal to
2866 -- convert implicitly are allowed in membership tests).
2868 if Ada_Version >= Ada_2012
2869 and then Ekind (Ctx_Type) = E_General_Access_Type
2870 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2871 and then Nkind (Parent (N)) not in N_Membership_Test
2873 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2874 Analyze_And_Resolve (N, Ctx_Type);
2877 -- If the subexpression was replaced by a non-subexpression, then
2878 -- all we do is to expand it. The only legitimate case we know of
2879 -- is converting procedure call statement to entry call statements,
2880 -- but there may be others, so we are making this test general.
2882 if Nkind (N) not in N_Subexpr then
2883 Debug_A_Exit ("resolving ", N, " (done)");
2888 -- The expression is definitely NOT overloaded at this point, so
2889 -- we reset the Is_Overloaded flag to avoid any confusion when
2890 -- reanalyzing the node.
2892 Set_Is_Overloaded (N, False);
2894 -- Freeze expression type, entity if it is a name, and designated
2895 -- type if it is an allocator (RM 13.14(10,11,13)).
2897 -- Now that the resolution of the type of the node is complete, and
2898 -- we did not detect an error, we can expand this node. We skip the
2899 -- expand call if we are in a default expression, see section
2900 -- "Handling of Default Expressions" in Sem spec.
2902 Debug_A_Exit ("resolving ", N, " (done)");
2904 -- We unconditionally freeze the expression, even if we are in
2905 -- default expression mode (the Freeze_Expression routine tests this
2906 -- flag and only freezes static types if it is set).
2908 -- Ada 2012 (AI05-177): The declaration of an expression function
2909 -- does not cause freezing, but we never reach here in that case.
2910 -- Here we are resolving the corresponding expanded body, so we do
2911 -- need to perform normal freezing.
2913 Freeze_Expression (N);
2915 -- Now we can do the expansion
2925 -- Version with check(s) suppressed
2927 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2929 if Suppress = All_Checks then
2931 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
2933 Scope_Suppress.Suppress := (others => True);
2935 Scope_Suppress.Suppress := Sva;
2940 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
2942 Scope_Suppress.Suppress (Suppress) := True;
2944 Scope_Suppress.Suppress (Suppress) := Svg;
2953 -- Version with implicit type
2955 procedure Resolve (N : Node_Id) is
2957 Resolve (N, Etype (N));
2960 ---------------------
2961 -- Resolve_Actuals --
2962 ---------------------
2964 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2965 Loc : constant Source_Ptr := Sloc (N);
2971 Prev : Node_Id := Empty;
2974 procedure Check_Argument_Order;
2975 -- Performs a check for the case where the actuals are all simple
2976 -- identifiers that correspond to the formal names, but in the wrong
2977 -- order, which is considered suspicious and cause for a warning.
2979 procedure Check_Prefixed_Call;
2980 -- If the original node is an overloaded call in prefix notation,
2981 -- insert an 'Access or a dereference as needed over the first actual.
2982 -- Try_Object_Operation has already verified that there is a valid
2983 -- interpretation, but the form of the actual can only be determined
2984 -- once the primitive operation is identified.
2986 procedure Insert_Default;
2987 -- If the actual is missing in a call, insert in the actuals list
2988 -- an instance of the default expression. The insertion is always
2989 -- a named association.
2991 procedure Property_Error
2994 Prop_Nam : Name_Id);
2995 -- Emit an error concerning variable Var with entity Var_Id that has
2996 -- enabled property Prop_Nam when it acts as an actual parameter in a
2997 -- call and the corresponding formal parameter is of mode IN.
2999 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3000 -- Check whether T1 and T2, or their full views, are derived from a
3001 -- common type. Used to enforce the restrictions on array conversions
3004 function Static_Concatenation (N : Node_Id) return Boolean;
3005 -- Predicate to determine whether an actual that is a concatenation
3006 -- will be evaluated statically and does not need a transient scope.
3007 -- This must be determined before the actual is resolved and expanded
3008 -- because if needed the transient scope must be introduced earlier.
3010 --------------------------
3011 -- Check_Argument_Order --
3012 --------------------------
3014 procedure Check_Argument_Order is
3016 -- Nothing to do if no parameters, or original node is neither a
3017 -- function call nor a procedure call statement (happens in the
3018 -- operator-transformed-to-function call case), or the call does
3019 -- not come from source, or this warning is off.
3021 if not Warn_On_Parameter_Order
3022 or else No (Parameter_Associations (N))
3023 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3024 or else not Comes_From_Source (N)
3030 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3033 -- Nothing to do if only one parameter
3039 -- Here if at least two arguments
3042 Actuals : array (1 .. Nargs) of Node_Id;
3046 Wrong_Order : Boolean := False;
3047 -- Set True if an out of order case is found
3050 -- Collect identifier names of actuals, fail if any actual is
3051 -- not a simple identifier, and record max length of name.
3053 Actual := First (Parameter_Associations (N));
3054 for J in Actuals'Range loop
3055 if Nkind (Actual) /= N_Identifier then
3058 Actuals (J) := Actual;
3063 -- If we got this far, all actuals are identifiers and the list
3064 -- of their names is stored in the Actuals array.
3066 Formal := First_Formal (Nam);
3067 for J in Actuals'Range loop
3069 -- If we ran out of formals, that's odd, probably an error
3070 -- which will be detected elsewhere, but abandon the search.
3076 -- If name matches and is in order OK
3078 if Chars (Formal) = Chars (Actuals (J)) then
3082 -- If no match, see if it is elsewhere in list and if so
3083 -- flag potential wrong order if type is compatible.
3085 for K in Actuals'Range loop
3086 if Chars (Formal) = Chars (Actuals (K))
3088 Has_Compatible_Type (Actuals (K), Etype (Formal))
3090 Wrong_Order := True;
3100 <<Continue>> Next_Formal (Formal);
3103 -- If Formals left over, also probably an error, skip warning
3105 if Present (Formal) then
3109 -- Here we give the warning if something was out of order
3113 ("?P?actuals for this call may be in wrong order", N);
3117 end Check_Argument_Order;
3119 -------------------------
3120 -- Check_Prefixed_Call --
3121 -------------------------
3123 procedure Check_Prefixed_Call is
3124 Act : constant Node_Id := First_Actual (N);
3125 A_Type : constant Entity_Id := Etype (Act);
3126 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3127 Orig : constant Node_Id := Original_Node (N);
3131 -- Check whether the call is a prefixed call, with or without
3132 -- additional actuals.
3134 if Nkind (Orig) = N_Selected_Component
3136 (Nkind (Orig) = N_Indexed_Component
3137 and then Nkind (Prefix (Orig)) = N_Selected_Component
3138 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3139 and then Is_Entity_Name (Act)
3140 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3142 if Is_Access_Type (A_Type)
3143 and then not Is_Access_Type (F_Type)
3145 -- Introduce dereference on object in prefix
3148 Make_Explicit_Dereference (Sloc (Act),
3149 Prefix => Relocate_Node (Act));
3150 Rewrite (Act, New_A);
3153 elsif Is_Access_Type (F_Type)
3154 and then not Is_Access_Type (A_Type)
3156 -- Introduce an implicit 'Access in prefix
3158 if not Is_Aliased_View (Act) then
3160 ("object in prefixed call to& must be aliased"
3161 & " (RM-2005 4.3.1 (13))",
3166 Make_Attribute_Reference (Loc,
3167 Attribute_Name => Name_Access,
3168 Prefix => Relocate_Node (Act)));
3173 end Check_Prefixed_Call;
3175 --------------------
3176 -- Insert_Default --
3177 --------------------
3179 procedure Insert_Default is
3184 -- Missing argument in call, nothing to insert
3186 if No (Default_Value (F)) then
3190 -- Note that we do a full New_Copy_Tree, so that any associated
3191 -- Itypes are properly copied. This may not be needed any more,
3192 -- but it does no harm as a safety measure. Defaults of a generic
3193 -- formal may be out of bounds of the corresponding actual (see
3194 -- cc1311b) and an additional check may be required.
3199 New_Scope => Current_Scope,
3202 if Is_Concurrent_Type (Scope (Nam))
3203 and then Has_Discriminants (Scope (Nam))
3205 Replace_Actual_Discriminants (N, Actval);
3208 if Is_Overloadable (Nam)
3209 and then Present (Alias (Nam))
3211 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3212 and then not Is_Tagged_Type (Etype (F))
3214 -- If default is a real literal, do not introduce a
3215 -- conversion whose effect may depend on the run-time
3216 -- size of universal real.
3218 if Nkind (Actval) = N_Real_Literal then
3219 Set_Etype (Actval, Base_Type (Etype (F)));
3221 Actval := Unchecked_Convert_To (Etype (F), Actval);
3225 if Is_Scalar_Type (Etype (F)) then
3226 Enable_Range_Check (Actval);
3229 Set_Parent (Actval, N);
3231 -- Resolve aggregates with their base type, to avoid scope
3232 -- anomalies: the subtype was first built in the subprogram
3233 -- declaration, and the current call may be nested.
3235 if Nkind (Actval) = N_Aggregate then
3236 Analyze_And_Resolve (Actval, Etype (F));
3238 Analyze_And_Resolve (Actval, Etype (Actval));
3242 Set_Parent (Actval, N);
3244 -- See note above concerning aggregates
3246 if Nkind (Actval) = N_Aggregate
3247 and then Has_Discriminants (Etype (Actval))
3249 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3251 -- Resolve entities with their own type, which may differ from
3252 -- the type of a reference in a generic context (the view
3253 -- swapping mechanism did not anticipate the re-analysis of
3254 -- default values in calls).
3256 elsif Is_Entity_Name (Actval) then
3257 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3260 Analyze_And_Resolve (Actval, Etype (Actval));
3264 -- If default is a tag indeterminate function call, propagate tag
3265 -- to obtain proper dispatching.
3267 if Is_Controlling_Formal (F)
3268 and then Nkind (Default_Value (F)) = N_Function_Call
3270 Set_Is_Controlling_Actual (Actval);
3275 -- If the default expression raises constraint error, then just
3276 -- silently replace it with an N_Raise_Constraint_Error node, since
3277 -- we already gave the warning on the subprogram spec. If node is
3278 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3279 -- the warnings removal machinery.
3281 if Raises_Constraint_Error (Actval)
3282 and then Nkind (Actval) /= N_Raise_Constraint_Error
3285 Make_Raise_Constraint_Error (Loc,
3286 Reason => CE_Range_Check_Failed));
3287 Set_Raises_Constraint_Error (Actval);
3288 Set_Etype (Actval, Etype (F));
3292 Make_Parameter_Association (Loc,
3293 Explicit_Actual_Parameter => Actval,
3294 Selector_Name => Make_Identifier (Loc, Chars (F)));
3296 -- Case of insertion is first named actual
3298 if No (Prev) or else
3299 Nkind (Parent (Prev)) /= N_Parameter_Association
3301 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3302 Set_First_Named_Actual (N, Actval);
3305 if No (Parameter_Associations (N)) then
3306 Set_Parameter_Associations (N, New_List (Assoc));
3308 Append (Assoc, Parameter_Associations (N));
3312 Insert_After (Prev, Assoc);
3315 -- Case of insertion is not first named actual
3318 Set_Next_Named_Actual
3319 (Assoc, Next_Named_Actual (Parent (Prev)));
3320 Set_Next_Named_Actual (Parent (Prev), Actval);
3321 Append (Assoc, Parameter_Associations (N));
3324 Mark_Rewrite_Insertion (Assoc);
3325 Mark_Rewrite_Insertion (Actval);
3330 --------------------
3331 -- Property_Error --
3332 --------------------
3334 procedure Property_Error
3340 Error_Msg_Name_1 := Prop_Nam;
3342 ("external variable & with enabled property % cannot appear as "
3343 & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id);
3344 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3351 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3352 FT1 : Entity_Id := T1;
3353 FT2 : Entity_Id := T2;
3356 if Is_Private_Type (T1)
3357 and then Present (Full_View (T1))
3359 FT1 := Full_View (T1);
3362 if Is_Private_Type (T2)
3363 and then Present (Full_View (T2))
3365 FT2 := Full_View (T2);
3368 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3371 --------------------------
3372 -- Static_Concatenation --
3373 --------------------------
3375 function Static_Concatenation (N : Node_Id) return Boolean is
3378 when N_String_Literal =>
3383 -- Concatenation is static when both operands are static and
3384 -- the concatenation operator is a predefined one.
3386 return Scope (Entity (N)) = Standard_Standard
3388 Static_Concatenation (Left_Opnd (N))
3390 Static_Concatenation (Right_Opnd (N));
3393 if Is_Entity_Name (N) then
3395 Ent : constant Entity_Id := Entity (N);
3397 return Ekind (Ent) = E_Constant
3398 and then Present (Constant_Value (Ent))
3400 Is_Static_Expression (Constant_Value (Ent));
3407 end Static_Concatenation;
3409 -- Start of processing for Resolve_Actuals
3412 Check_Argument_Order;
3413 Check_Function_Writable_Actuals (N);
3415 if Present (First_Actual (N)) then
3416 Check_Prefixed_Call;
3419 A := First_Actual (N);
3420 F := First_Formal (Nam);
3421 while Present (F) loop
3422 if No (A) and then Needs_No_Actuals (Nam) then
3425 -- If we have an error in any actual or formal, indicated by a type
3426 -- of Any_Type, then abandon resolution attempt, and set result type
3427 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3428 -- type is imposed from context.
3430 elsif (Present (A) and then Etype (A) = Any_Type)
3431 or else Etype (F) = Any_Type
3433 if Nkind (A) /= N_Raise_Expression then
3434 Set_Etype (N, Any_Type);
3439 -- Case where actual is present
3441 -- If the actual is an entity, generate a reference to it now. We
3442 -- do this before the actual is resolved, because a formal of some
3443 -- protected subprogram, or a task discriminant, will be rewritten
3444 -- during expansion, and the source entity reference may be lost.
3447 and then Is_Entity_Name (A)
3448 and then Comes_From_Source (N)
3450 Orig_A := Entity (A);
3452 if Present (Orig_A) then
3453 if Is_Formal (Orig_A)
3454 and then Ekind (F) /= E_In_Parameter
3456 Generate_Reference (Orig_A, A, 'm');
3458 elsif not Is_Overloaded (A) then
3459 if Ekind (F) /= E_Out_Parameter then
3460 Generate_Reference (Orig_A, A);
3462 -- RM 6.4.1(12): For an out parameter that is passed by
3463 -- copy, the formal parameter object is created, and:
3465 -- * For an access type, the formal parameter is initialized
3466 -- from the value of the actual, without checking that the
3467 -- value satisfies any constraint, any predicate, or any
3468 -- exclusion of the null value.
3470 -- * For a scalar type that has the Default_Value aspect
3471 -- specified, the formal parameter is initialized from the
3472 -- value of the actual, without checking that the value
3473 -- satisfies any constraint or any predicate.
3474 -- I do not understand why this case is included??? this is
3475 -- not a case where an OUT parameter is treated as IN OUT.
3477 -- * For a composite type with discriminants or that has
3478 -- implicit initial values for any subcomponents, the
3479 -- behavior is as for an in out parameter passed by copy.
3481 -- Hence for these cases we generate the read reference now
3482 -- (the write reference will be generated later by
3483 -- Note_Possible_Modification).
3485 elsif Is_By_Copy_Type (Etype (F))
3487 (Is_Access_Type (Etype (F))
3489 (Is_Scalar_Type (Etype (F))
3491 Present (Default_Aspect_Value (Etype (F))))
3493 (Is_Composite_Type (Etype (F))
3494 and then (Has_Discriminants (Etype (F))
3495 or else Is_Partially_Initialized_Type
3498 Generate_Reference (Orig_A, A);
3505 and then (Nkind (Parent (A)) /= N_Parameter_Association
3506 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3508 -- If style checking mode on, check match of formal name
3511 if Nkind (Parent (A)) = N_Parameter_Association then
3512 Check_Identifier (Selector_Name (Parent (A)), F);
3516 -- If the formal is Out or In_Out, do not resolve and expand the
3517 -- conversion, because it is subsequently expanded into explicit
3518 -- temporaries and assignments. However, the object of the
3519 -- conversion can be resolved. An exception is the case of tagged
3520 -- type conversion with a class-wide actual. In that case we want
3521 -- the tag check to occur and no temporary will be needed (no
3522 -- representation change can occur) and the parameter is passed by
3523 -- reference, so we go ahead and resolve the type conversion.
3524 -- Another exception is the case of reference to component or
3525 -- subcomponent of a bit-packed array, in which case we want to
3526 -- defer expansion to the point the in and out assignments are
3529 if Ekind (F) /= E_In_Parameter
3530 and then Nkind (A) = N_Type_Conversion
3531 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3533 if Ekind (F) = E_In_Out_Parameter
3534 and then Is_Array_Type (Etype (F))
3536 -- In a view conversion, the conversion must be legal in
3537 -- both directions, and thus both component types must be
3538 -- aliased, or neither (4.6 (8)).
3540 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3541 -- the privacy requirement should not apply to generic
3542 -- types, and should be checked in an instance. ARG query
3545 if Has_Aliased_Components (Etype (Expression (A))) /=
3546 Has_Aliased_Components (Etype (F))
3549 ("both component types in a view conversion must be"
3550 & " aliased, or neither", A);
3552 -- Comment here??? what set of cases???
3555 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3557 -- Check view conv between unrelated by ref array types
3559 if Is_By_Reference_Type (Etype (F))
3560 or else Is_By_Reference_Type (Etype (Expression (A)))
3563 ("view conversion between unrelated by reference "
3564 & "array types not allowed (\'A'I-00246)", A);
3566 -- In Ada 2005 mode, check view conversion component
3567 -- type cannot be private, tagged, or volatile. Note
3568 -- that we only apply this to source conversions. The
3569 -- generated code can contain conversions which are
3570 -- not subject to this test, and we cannot extract the
3571 -- component type in such cases since it is not present.
3573 elsif Comes_From_Source (A)
3574 and then Ada_Version >= Ada_2005
3577 Comp_Type : constant Entity_Id :=
3579 (Etype (Expression (A)));
3581 if (Is_Private_Type (Comp_Type)
3582 and then not Is_Generic_Type (Comp_Type))
3583 or else Is_Tagged_Type (Comp_Type)
3584 or else Is_Volatile (Comp_Type)
3587 ("component type of a view conversion cannot"
3588 & " be private, tagged, or volatile"
3597 -- Resolve expression if conversion is all OK
3599 if (Conversion_OK (A)
3600 or else Valid_Conversion (A, Etype (A), Expression (A)))
3601 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3603 Resolve (Expression (A));
3606 -- If the actual is a function call that returns a limited
3607 -- unconstrained object that needs finalization, create a
3608 -- transient scope for it, so that it can receive the proper
3609 -- finalization list.
3611 elsif Nkind (A) = N_Function_Call
3612 and then Is_Limited_Record (Etype (F))
3613 and then not Is_Constrained (Etype (F))
3614 and then Expander_Active
3615 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3617 Establish_Transient_Scope (A, Sec_Stack => False);
3618 Resolve (A, Etype (F));
3620 -- A small optimization: if one of the actuals is a concatenation
3621 -- create a block around a procedure call to recover stack space.
3622 -- This alleviates stack usage when several procedure calls in
3623 -- the same statement list use concatenation. We do not perform
3624 -- this wrapping for code statements, where the argument is a
3625 -- static string, and we want to preserve warnings involving
3626 -- sequences of such statements.
3628 elsif Nkind (A) = N_Op_Concat
3629 and then Nkind (N) = N_Procedure_Call_Statement
3630 and then Expander_Active
3632 not (Is_Intrinsic_Subprogram (Nam)
3633 and then Chars (Nam) = Name_Asm)
3634 and then not Static_Concatenation (A)
3636 Establish_Transient_Scope (A, Sec_Stack => False);
3637 Resolve (A, Etype (F));
3640 if Nkind (A) = N_Type_Conversion
3641 and then Is_Array_Type (Etype (F))
3642 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3644 (Is_Limited_Type (Etype (F))
3645 or else Is_Limited_Type (Etype (Expression (A))))
3648 ("conversion between unrelated limited array types "
3649 & "not allowed ('A'I-00246)", A);
3651 if Is_Limited_Type (Etype (F)) then
3652 Explain_Limited_Type (Etype (F), A);
3655 if Is_Limited_Type (Etype (Expression (A))) then
3656 Explain_Limited_Type (Etype (Expression (A)), A);
3660 -- (Ada 2005: AI-251): If the actual is an allocator whose
3661 -- directly designated type is a class-wide interface, we build
3662 -- an anonymous access type to use it as the type of the
3663 -- allocator. Later, when the subprogram call is expanded, if
3664 -- the interface has a secondary dispatch table the expander
3665 -- will add a type conversion to force the correct displacement
3668 if Nkind (A) = N_Allocator then
3670 DDT : constant Entity_Id :=
3671 Directly_Designated_Type (Base_Type (Etype (F)));
3673 New_Itype : Entity_Id;
3676 if Is_Class_Wide_Type (DDT)
3677 and then Is_Interface (DDT)
3679 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3680 Set_Etype (New_Itype, Etype (A));
3681 Set_Directly_Designated_Type
3682 (New_Itype, Directly_Designated_Type (Etype (A)));
3683 Set_Etype (A, New_Itype);
3686 -- Ada 2005, AI-162:If the actual is an allocator, the
3687 -- innermost enclosing statement is the master of the
3688 -- created object. This needs to be done with expansion
3689 -- enabled only, otherwise the transient scope will not
3690 -- be removed in the expansion of the wrapped construct.
3692 if (Is_Controlled (DDT) or else Has_Task (DDT))
3693 and then Expander_Active
3695 Establish_Transient_Scope (A, Sec_Stack => False);
3699 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3700 Check_Restriction (No_Access_Parameter_Allocators, A);
3704 -- (Ada 2005): The call may be to a primitive operation of a
3705 -- tagged synchronized type, declared outside of the type. In
3706 -- this case the controlling actual must be converted to its
3707 -- corresponding record type, which is the formal type. The
3708 -- actual may be a subtype, either because of a constraint or
3709 -- because it is a generic actual, so use base type to locate
3712 F_Typ := Base_Type (Etype (F));
3714 if Is_Tagged_Type (F_Typ)
3715 and then (Is_Concurrent_Type (F_Typ)
3716 or else Is_Concurrent_Record_Type (F_Typ))
3718 -- If the actual is overloaded, look for an interpretation
3719 -- that has a synchronized type.
3721 if not Is_Overloaded (A) then
3722 A_Typ := Base_Type (Etype (A));
3726 Index : Interp_Index;
3730 Get_First_Interp (A, Index, It);
3731 while Present (It.Typ) loop
3732 if Is_Concurrent_Type (It.Typ)
3733 or else Is_Concurrent_Record_Type (It.Typ)
3735 A_Typ := Base_Type (It.Typ);
3739 Get_Next_Interp (Index, It);
3745 Full_A_Typ : Entity_Id;
3748 if Present (Full_View (A_Typ)) then
3749 Full_A_Typ := Base_Type (Full_View (A_Typ));
3751 Full_A_Typ := A_Typ;
3754 -- Tagged synchronized type (case 1): the actual is a
3757 if Is_Concurrent_Type (A_Typ)
3758 and then Corresponding_Record_Type (A_Typ) = F_Typ
3761 Unchecked_Convert_To
3762 (Corresponding_Record_Type (A_Typ), A));
3763 Resolve (A, Etype (F));
3765 -- Tagged synchronized type (case 2): the formal is a
3768 elsif Ekind (Full_A_Typ) = E_Record_Type
3770 (Corresponding_Concurrent_Type (Full_A_Typ))
3771 and then Is_Concurrent_Type (F_Typ)
3772 and then Present (Corresponding_Record_Type (F_Typ))
3773 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3775 Resolve (A, Corresponding_Record_Type (F_Typ));
3780 Resolve (A, Etype (F));
3784 -- Not a synchronized operation
3787 Resolve (A, Etype (F));
3794 if Comes_From_Source (Original_Node (N))
3795 and then Nkind_In (Original_Node (N), N_Function_Call,
3796 N_Procedure_Call_Statement)
3798 -- In formal mode, check that actual parameters matching
3799 -- formals of tagged types are objects (or ancestor type
3800 -- conversions of objects), not general expressions.
3802 if Is_Actual_Tagged_Parameter (A) then
3803 if Is_SPARK_Object_Reference (A) then
3806 elsif Nkind (A) = N_Type_Conversion then
3808 Operand : constant Node_Id := Expression (A);
3809 Operand_Typ : constant Entity_Id := Etype (Operand);
3810 Target_Typ : constant Entity_Id := A_Typ;
3813 if not Is_SPARK_Object_Reference (Operand) then
3814 Check_SPARK_Restriction
3815 ("object required", Operand);
3817 -- In formal mode, the only view conversions are those
3818 -- involving ancestor conversion of an extended type.
3821 (Is_Tagged_Type (Target_Typ)
3822 and then not Is_Class_Wide_Type (Target_Typ)
3823 and then Is_Tagged_Type (Operand_Typ)
3824 and then not Is_Class_Wide_Type (Operand_Typ)
3825 and then Is_Ancestor (Target_Typ, Operand_Typ))
3828 (F, E_Out_Parameter, E_In_Out_Parameter)
3830 Check_SPARK_Restriction
3831 ("ancestor conversion is the only permitted "
3832 & "view conversion", A);
3834 Check_SPARK_Restriction
3835 ("ancestor conversion required", A);
3844 Check_SPARK_Restriction ("object required", A);
3847 -- In formal mode, the only view conversions are those
3848 -- involving ancestor conversion of an extended type.
3850 elsif Nkind (A) = N_Type_Conversion
3851 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3853 Check_SPARK_Restriction
3854 ("ancestor conversion is the only permitted view "
3859 -- has warnings suppressed, then we reset Never_Set_In_Source for
3860 -- the calling entity. The reason for this is to catch cases like
3861 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3862 -- uses trickery to modify an IN parameter.
3864 if Ekind (F) = E_In_Parameter
3865 and then Is_Entity_Name (A)
3866 and then Present (Entity (A))
3867 and then Ekind (Entity (A)) = E_Variable
3868 and then Has_Warnings_Off (F_Typ)
3870 Set_Never_Set_In_Source (Entity (A), False);
3873 -- Perform error checks for IN and IN OUT parameters
3875 if Ekind (F) /= E_Out_Parameter then
3877 -- Check unset reference. For scalar parameters, it is clearly
3878 -- wrong to pass an uninitialized value as either an IN or
3879 -- IN-OUT parameter. For composites, it is also clearly an
3880 -- error to pass a completely uninitialized value as an IN
3881 -- parameter, but the case of IN OUT is trickier. We prefer
3882 -- not to give a warning here. For example, suppose there is
3883 -- a routine that sets some component of a record to False.
3884 -- It is perfectly reasonable to make this IN-OUT and allow
3885 -- either initialized or uninitialized records to be passed
3888 -- For partially initialized composite values, we also avoid
3889 -- warnings, since it is quite likely that we are passing a
3890 -- partially initialized value and only the initialized fields
3891 -- will in fact be read in the subprogram.
3893 if Is_Scalar_Type (A_Typ)
3894 or else (Ekind (F) = E_In_Parameter
3895 and then not Is_Partially_Initialized_Type (A_Typ))
3897 Check_Unset_Reference (A);
3900 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3901 -- actual to a nested call, since this is case of reading an
3902 -- out parameter, which is not allowed.
3904 if Ada_Version = Ada_83
3905 and then Is_Entity_Name (A)
3906 and then Ekind (Entity (A)) = E_Out_Parameter
3908 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3912 -- Case of OUT or IN OUT parameter
3914 if Ekind (F) /= E_In_Parameter then
3916 -- For an Out parameter, check for useless assignment. Note
3917 -- that we can't set Last_Assignment this early, because we may
3918 -- kill current values in Resolve_Call, and that call would
3919 -- clobber the Last_Assignment field.
3921 -- Note: call Warn_On_Useless_Assignment before doing the check
3922 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3923 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3924 -- reflects the last assignment, not this one.
3926 if Ekind (F) = E_Out_Parameter then
3927 if Warn_On_Modified_As_Out_Parameter (F)
3928 and then Is_Entity_Name (A)
3929 and then Present (Entity (A))
3930 and then Comes_From_Source (N)
3932 Warn_On_Useless_Assignment (Entity (A), A);
3936 -- Validate the form of the actual. Note that the call to
3937 -- Is_OK_Variable_For_Out_Formal generates the required
3938 -- reference in this case.
3940 -- A call to an initialization procedure for an aggregate
3941 -- component may initialize a nested component of a constant
3942 -- designated object. In this context the object is variable.
3944 if not Is_OK_Variable_For_Out_Formal (A)
3945 and then not Is_Init_Proc (Nam)
3947 Error_Msg_NE ("actual for& must be a variable", A, F);
3949 if Is_Subprogram (Current_Scope)
3951 (Is_Invariant_Procedure (Current_Scope)
3952 or else Is_Predicate_Function (Current_Scope))
3955 ("function used in predicate cannot "
3956 & "modify its argument", F);
3960 -- What's the following about???
3962 if Is_Entity_Name (A) then
3963 Kill_Checks (Entity (A));
3969 if Etype (A) = Any_Type then
3970 Set_Etype (N, Any_Type);
3974 -- Apply appropriate range checks for in, out, and in-out
3975 -- parameters. Out and in-out parameters also need a separate
3976 -- check, if there is a type conversion, to make sure the return
3977 -- value meets the constraints of the variable before the
3980 -- Gigi looks at the check flag and uses the appropriate types.
3981 -- For now since one flag is used there is an optimization which
3982 -- might not be done in the In Out case since Gigi does not do
3983 -- any analysis. More thought required about this ???
3985 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
3987 -- Apply predicate checks, unless this is a call to the
3988 -- predicate check function itself, which would cause an
3989 -- infinite recursion, or it is a call to an initialization
3990 -- procedure whose operand is of course an unfinished object.
3992 if not (Ekind (Nam) = E_Function
3993 and then (Is_Predicate_Function (Nam)
3995 Is_Predicate_Function_M (Nam)))
3996 and then not Is_Init_Proc (Nam)
3998 Apply_Predicate_Check (A, F_Typ);
4001 -- Apply required constraint checks
4003 if Is_Scalar_Type (Etype (A)) then
4004 Apply_Scalar_Range_Check (A, F_Typ);
4006 elsif Is_Array_Type (Etype (A)) then
4007 Apply_Length_Check (A, F_Typ);
4009 elsif Is_Record_Type (F_Typ)
4010 and then Has_Discriminants (F_Typ)
4011 and then Is_Constrained (F_Typ)
4012 and then (not Is_Derived_Type (F_Typ)
4013 or else Comes_From_Source (Nam))
4015 Apply_Discriminant_Check (A, F_Typ);
4017 -- For view conversions of a discriminated object, apply
4018 -- check to object itself, the conversion alreay has the
4021 if Nkind (A) = N_Type_Conversion
4022 and then Is_Constrained (Etype (Expression (A)))
4024 Apply_Discriminant_Check (Expression (A), F_Typ);
4027 elsif Is_Access_Type (F_Typ)
4028 and then Is_Array_Type (Designated_Type (F_Typ))
4029 and then Is_Constrained (Designated_Type (F_Typ))
4031 Apply_Length_Check (A, F_Typ);
4033 elsif Is_Access_Type (F_Typ)
4034 and then Has_Discriminants (Designated_Type (F_Typ))
4035 and then Is_Constrained (Designated_Type (F_Typ))
4037 Apply_Discriminant_Check (A, F_Typ);
4040 Apply_Range_Check (A, F_Typ);
4043 -- Ada 2005 (AI-231): Note that the controlling parameter case
4044 -- already existed in Ada 95, which is partially checked
4045 -- elsewhere (see Checks), and we don't want the warning
4046 -- message to differ.
4048 if Is_Access_Type (F_Typ)
4049 and then Can_Never_Be_Null (F_Typ)
4050 and then Known_Null (A)
4052 if Is_Controlling_Formal (F) then
4053 Apply_Compile_Time_Constraint_Error
4055 Msg => "null value not allowed here??",
4056 Reason => CE_Access_Check_Failed);
4058 elsif Ada_Version >= Ada_2005 then
4059 Apply_Compile_Time_Constraint_Error
4061 Msg => "(Ada 2005) null not allowed in "
4062 & "null-excluding formal??",
4063 Reason => CE_Null_Not_Allowed);
4068 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4069 if Nkind (A) = N_Type_Conversion then
4070 if Is_Scalar_Type (A_Typ) then
4071 Apply_Scalar_Range_Check
4072 (Expression (A), Etype (Expression (A)), A_Typ);
4075 (Expression (A), Etype (Expression (A)), A_Typ);
4079 if Is_Scalar_Type (F_Typ) then
4080 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4081 elsif Is_Array_Type (F_Typ)
4082 and then Ekind (F) = E_Out_Parameter
4084 Apply_Length_Check (A, F_Typ);
4086 Apply_Range_Check (A, A_Typ, F_Typ);
4091 -- An actual associated with an access parameter is implicitly
4092 -- converted to the anonymous access type of the formal and must
4093 -- satisfy the legality checks for access conversions.
4095 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4096 if not Valid_Conversion (A, F_Typ, A) then
4098 ("invalid implicit conversion for access parameter", A);
4101 -- If the actual is an access selected component of a variable,
4102 -- the call may modify its designated object. It is reasonable
4103 -- to treat this as a potential modification of the enclosing
4104 -- record, to prevent spurious warnings that it should be
4105 -- declared as a constant, because intuitively programmers
4106 -- regard the designated subcomponent as part of the record.
4108 if Nkind (A) = N_Selected_Component
4109 and then Is_Entity_Name (Prefix (A))
4110 and then not Is_Constant_Object (Entity (Prefix (A)))
4112 Note_Possible_Modification (A, Sure => False);
4116 -- Check bad case of atomic/volatile argument (RM C.6(12))
4118 if Is_By_Reference_Type (Etype (F))
4119 and then Comes_From_Source (N)
4121 if Is_Atomic_Object (A)
4122 and then not Is_Atomic (Etype (F))
4125 ("cannot pass atomic argument to non-atomic formal&",
4128 elsif Is_Volatile_Object (A)
4129 and then not Is_Volatile (Etype (F))
4132 ("cannot pass volatile argument to non-volatile formal&",
4137 -- Check that subprograms don't have improper controlling
4138 -- arguments (RM 3.9.2 (9)).
4140 -- A primitive operation may have an access parameter of an
4141 -- incomplete tagged type, but a dispatching call is illegal
4142 -- if the type is still incomplete.
4144 if Is_Controlling_Formal (F) then
4145 Set_Is_Controlling_Actual (A);
4147 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4149 Desig : constant Entity_Id := Designated_Type (Etype (F));
4151 if Ekind (Desig) = E_Incomplete_Type
4152 and then No (Full_View (Desig))
4153 and then No (Non_Limited_View (Desig))
4156 ("premature use of incomplete type& "
4157 & "in dispatching call", A, Desig);
4162 elsif Nkind (A) = N_Explicit_Dereference then
4163 Validate_Remote_Access_To_Class_Wide_Type (A);
4166 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4167 and then not Is_Class_Wide_Type (F_Typ)
4168 and then not Is_Controlling_Formal (F)
4170 Error_Msg_N ("class-wide argument not allowed here!", A);
4172 if Is_Subprogram (Nam)
4173 and then Comes_From_Source (Nam)
4175 Error_Msg_Node_2 := F_Typ;
4177 ("& is not a dispatching operation of &!", A, Nam);
4180 -- Apply the checks described in 3.10.2(27): if the context is a
4181 -- specific access-to-object, the actual cannot be class-wide.
4182 -- Use base type to exclude access_to_subprogram cases.
4184 elsif Is_Access_Type (A_Typ)
4185 and then Is_Access_Type (F_Typ)
4186 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4187 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4188 or else (Nkind (A) = N_Attribute_Reference
4190 Is_Class_Wide_Type (Etype (Prefix (A)))))
4191 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4192 and then not Is_Controlling_Formal (F)
4194 -- Disable these checks for call to imported C++ subprograms
4197 (Is_Entity_Name (Name (N))
4198 and then Is_Imported (Entity (Name (N)))
4199 and then Convention (Entity (Name (N))) = Convention_CPP)
4202 ("access to class-wide argument not allowed here!", A);
4204 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4205 Error_Msg_Node_2 := Designated_Type (F_Typ);
4207 ("& is not a dispatching operation of &!", A, Nam);
4213 -- If it is a named association, treat the selector_name as a
4214 -- proper identifier, and mark the corresponding entity.
4216 if Nkind (Parent (A)) = N_Parameter_Association
4218 -- Ignore reference in SPARK mode, as it refers to an entity not
4219 -- in scope at the point of reference, so the reference should
4220 -- be ignored for computing effects of subprograms.
4222 and then not GNATprove_Mode
4224 Set_Entity (Selector_Name (Parent (A)), F);
4225 Generate_Reference (F, Selector_Name (Parent (A)));
4226 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4227 Generate_Reference (F_Typ, N, ' ');
4232 if Ekind (F) /= E_Out_Parameter then
4233 Check_Unset_Reference (A);
4236 -- The following checks are only relevant when SPARK_Mode is on as
4237 -- they are not standard Ada legality rule.
4240 and then Is_SPARK_Volatile_Object (A)
4242 -- A volatile object may act as an actual parameter when the
4243 -- corresponding formal is of a non-scalar volatile type.
4245 if Is_Volatile (Etype (F))
4246 and then not Is_Scalar_Type (Etype (F))
4250 -- A volatile object may act as an actual parameter in a call
4251 -- to an instance of Unchecked_Conversion.
4253 elsif Is_Unchecked_Conversion_Instance (Nam) then
4258 ("volatile object cannot act as actual in a call (SPARK "
4259 & "RM 7.1.3(12))", A);
4262 -- Detect an external variable with an enabled property that
4263 -- does not match the mode of the corresponding formal in a
4266 -- why only procedure calls ???
4268 if Ekind (Nam) = E_Procedure
4269 and then Is_Entity_Name (A)
4270 and then Present (Entity (A))
4271 and then Ekind (Entity (A)) = E_Variable
4275 if Ekind (F) = E_In_Parameter then
4276 if Async_Readers_Enabled (A_Id) then
4277 Property_Error (A, A_Id, Name_Async_Readers);
4278 elsif Effective_Reads_Enabled (A_Id) then
4279 Property_Error (A, A_Id, Name_Effective_Reads);
4280 elsif Effective_Writes_Enabled (A_Id) then
4281 Property_Error (A, A_Id, Name_Effective_Writes);
4284 elsif Ekind (F) = E_Out_Parameter
4285 and then Async_Writers_Enabled (A_Id)
4287 Error_Msg_Name_1 := Name_Async_Writers;
4289 ("external variable & with enabled property % cannot "
4290 & "appear as actual in procedure call "
4291 & "(SPARK RM 7.1.3(11))", A, A_Id);
4293 ("\\corresponding formal parameter has mode Out", A);
4300 -- Case where actual is not present
4308 end Resolve_Actuals;
4310 -----------------------
4311 -- Resolve_Allocator --
4312 -----------------------
4314 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4315 Desig_T : constant Entity_Id := Designated_Type (Typ);
4316 E : constant Node_Id := Expression (N);
4318 Discrim : Entity_Id;
4321 Assoc : Node_Id := Empty;
4324 procedure Check_Allocator_Discrim_Accessibility
4325 (Disc_Exp : Node_Id;
4326 Alloc_Typ : Entity_Id);
4327 -- Check that accessibility level associated with an access discriminant
4328 -- initialized in an allocator by the expression Disc_Exp is not deeper
4329 -- than the level of the allocator type Alloc_Typ. An error message is
4330 -- issued if this condition is violated. Specialized checks are done for
4331 -- the cases of a constraint expression which is an access attribute or
4332 -- an access discriminant.
4334 function In_Dispatching_Context return Boolean;
4335 -- If the allocator is an actual in a call, it is allowed to be class-
4336 -- wide when the context is not because it is a controlling actual.
4338 -------------------------------------------
4339 -- Check_Allocator_Discrim_Accessibility --
4340 -------------------------------------------
4342 procedure Check_Allocator_Discrim_Accessibility
4343 (Disc_Exp : Node_Id;
4344 Alloc_Typ : Entity_Id)
4347 if Type_Access_Level (Etype (Disc_Exp)) >
4348 Deepest_Type_Access_Level (Alloc_Typ)
4351 ("operand type has deeper level than allocator type", Disc_Exp);
4353 -- When the expression is an Access attribute the level of the prefix
4354 -- object must not be deeper than that of the allocator's type.
4356 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4357 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4359 and then Object_Access_Level (Prefix (Disc_Exp)) >
4360 Deepest_Type_Access_Level (Alloc_Typ)
4363 ("prefix of attribute has deeper level than allocator type",
4366 -- When the expression is an access discriminant the check is against
4367 -- the level of the prefix object.
4369 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4370 and then Nkind (Disc_Exp) = N_Selected_Component
4371 and then Object_Access_Level (Prefix (Disc_Exp)) >
4372 Deepest_Type_Access_Level (Alloc_Typ)
4375 ("access discriminant has deeper level than allocator type",
4378 -- All other cases are legal
4383 end Check_Allocator_Discrim_Accessibility;
4385 ----------------------------
4386 -- In_Dispatching_Context --
4387 ----------------------------
4389 function In_Dispatching_Context return Boolean is
4390 Par : constant Node_Id := Parent (N);
4393 return Nkind (Par) in N_Subprogram_Call
4394 and then Is_Entity_Name (Name (Par))
4395 and then Is_Dispatching_Operation (Entity (Name (Par)));
4396 end In_Dispatching_Context;
4398 -- Start of processing for Resolve_Allocator
4401 -- Replace general access with specific type
4403 if Ekind (Etype (N)) = E_Allocator_Type then
4404 Set_Etype (N, Base_Type (Typ));
4407 if Is_Abstract_Type (Typ) then
4408 Error_Msg_N ("type of allocator cannot be abstract", N);
4411 -- For qualified expression, resolve the expression using the given
4412 -- subtype (nothing to do for type mark, subtype indication)
4414 if Nkind (E) = N_Qualified_Expression then
4415 if Is_Class_Wide_Type (Etype (E))
4416 and then not Is_Class_Wide_Type (Desig_T)
4417 and then not In_Dispatching_Context
4420 ("class-wide allocator not allowed for this access type", N);
4423 Resolve (Expression (E), Etype (E));
4424 Check_Unset_Reference (Expression (E));
4426 -- A qualified expression requires an exact match of the type.
4427 -- Class-wide matching is not allowed.
4429 if (Is_Class_Wide_Type (Etype (Expression (E)))
4430 or else Is_Class_Wide_Type (Etype (E)))
4431 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4433 Wrong_Type (Expression (E), Etype (E));
4436 -- Calls to build-in-place functions are not currently supported in
4437 -- allocators for access types associated with a simple storage pool.
4438 -- Supporting such allocators may require passing additional implicit
4439 -- parameters to build-in-place functions (or a significant revision
4440 -- of the current b-i-p implementation to unify the handling for
4441 -- multiple kinds of storage pools). ???
4443 if Is_Limited_View (Desig_T)
4444 and then Nkind (Expression (E)) = N_Function_Call
4447 Pool : constant Entity_Id :=
4448 Associated_Storage_Pool (Root_Type (Typ));
4452 Present (Get_Rep_Pragma
4453 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4456 ("limited function calls not yet supported in simple "
4457 & "storage pool allocators", Expression (E));
4462 -- A special accessibility check is needed for allocators that
4463 -- constrain access discriminants. The level of the type of the
4464 -- expression used to constrain an access discriminant cannot be
4465 -- deeper than the type of the allocator (in contrast to access
4466 -- parameters, where the level of the actual can be arbitrary).
4468 -- We can't use Valid_Conversion to perform this check because in
4469 -- general the type of the allocator is unrelated to the type of
4470 -- the access discriminant.
4472 if Ekind (Typ) /= E_Anonymous_Access_Type
4473 or else Is_Local_Anonymous_Access (Typ)
4475 Subtyp := Entity (Subtype_Mark (E));
4477 Aggr := Original_Node (Expression (E));
4479 if Has_Discriminants (Subtyp)
4480 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4482 Discrim := First_Discriminant (Base_Type (Subtyp));
4484 -- Get the first component expression of the aggregate
4486 if Present (Expressions (Aggr)) then
4487 Disc_Exp := First (Expressions (Aggr));
4489 elsif Present (Component_Associations (Aggr)) then
4490 Assoc := First (Component_Associations (Aggr));
4492 if Present (Assoc) then
4493 Disc_Exp := Expression (Assoc);
4502 while Present (Discrim) and then Present (Disc_Exp) loop
4503 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4504 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4507 Next_Discriminant (Discrim);
4509 if Present (Discrim) then
4510 if Present (Assoc) then
4512 Disc_Exp := Expression (Assoc);
4514 elsif Present (Next (Disc_Exp)) then
4518 Assoc := First (Component_Associations (Aggr));
4520 if Present (Assoc) then
4521 Disc_Exp := Expression (Assoc);
4531 -- For a subtype mark or subtype indication, freeze the subtype
4534 Freeze_Expression (E);
4536 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4538 ("initialization required for access-to-constant allocator", N);
4541 -- A special accessibility check is needed for allocators that
4542 -- constrain access discriminants. The level of the type of the
4543 -- expression used to constrain an access discriminant cannot be
4544 -- deeper than the type of the allocator (in contrast to access
4545 -- parameters, where the level of the actual can be arbitrary).
4546 -- We can't use Valid_Conversion to perform this check because
4547 -- in general the type of the allocator is unrelated to the type
4548 -- of the access discriminant.
4550 if Nkind (Original_Node (E)) = N_Subtype_Indication
4551 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4552 or else Is_Local_Anonymous_Access (Typ))
4554 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4556 if Has_Discriminants (Subtyp) then
4557 Discrim := First_Discriminant (Base_Type (Subtyp));
4558 Constr := First (Constraints (Constraint (Original_Node (E))));
4559 while Present (Discrim) and then Present (Constr) loop
4560 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4561 if Nkind (Constr) = N_Discriminant_Association then
4562 Disc_Exp := Original_Node (Expression (Constr));
4564 Disc_Exp := Original_Node (Constr);
4567 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4570 Next_Discriminant (Discrim);
4577 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4578 -- check that the level of the type of the created object is not deeper
4579 -- than the level of the allocator's access type, since extensions can
4580 -- now occur at deeper levels than their ancestor types. This is a
4581 -- static accessibility level check; a run-time check is also needed in
4582 -- the case of an initialized allocator with a class-wide argument (see
4583 -- Expand_Allocator_Expression).
4585 if Ada_Version >= Ada_2005
4586 and then Is_Class_Wide_Type (Desig_T)
4589 Exp_Typ : Entity_Id;
4592 if Nkind (E) = N_Qualified_Expression then
4593 Exp_Typ := Etype (E);
4594 elsif Nkind (E) = N_Subtype_Indication then
4595 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4597 Exp_Typ := Entity (E);
4600 if Type_Access_Level (Exp_Typ) >
4601 Deepest_Type_Access_Level (Typ)
4603 if In_Instance_Body then
4604 Error_Msg_Warn := SPARK_Mode /= On;
4606 ("type in allocator has deeper level than "
4607 & "designated class-wide type<<", E);
4608 Error_Msg_N ("\Program_Error [<<", E);
4610 Make_Raise_Program_Error (Sloc (N),
4611 Reason => PE_Accessibility_Check_Failed));
4614 -- Do not apply Ada 2005 accessibility checks on a class-wide
4615 -- allocator if the type given in the allocator is a formal
4616 -- type. A run-time check will be performed in the instance.
4618 elsif not Is_Generic_Type (Exp_Typ) then
4619 Error_Msg_N ("type in allocator has deeper level than "
4620 & "designated class-wide type", E);
4626 -- Check for allocation from an empty storage pool
4628 if No_Pool_Assigned (Typ) then
4629 Error_Msg_N ("allocation from empty storage pool!", N);
4631 -- If the context is an unchecked conversion, as may happen within an
4632 -- inlined subprogram, the allocator is being resolved with its own
4633 -- anonymous type. In that case, if the target type has a specific
4634 -- storage pool, it must be inherited explicitly by the allocator type.
4636 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4637 and then No (Associated_Storage_Pool (Typ))
4639 Set_Associated_Storage_Pool
4640 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4643 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4644 Check_Restriction (No_Anonymous_Allocators, N);
4647 -- Check that an allocator with task parts isn't for a nested access
4648 -- type when restriction No_Task_Hierarchy applies.
4650 if not Is_Library_Level_Entity (Base_Type (Typ))
4651 and then Has_Task (Base_Type (Desig_T))
4653 Check_Restriction (No_Task_Hierarchy, N);
4656 -- An illegal allocator may be rewritten as a raise Program_Error
4659 if Nkind (N) = N_Allocator then
4661 -- An anonymous access discriminant is the definition of a
4664 if Ekind (Typ) = E_Anonymous_Access_Type
4665 and then Nkind (Associated_Node_For_Itype (Typ)) =
4666 N_Discriminant_Specification
4669 Discr : constant Entity_Id :=
4670 Defining_Identifier (Associated_Node_For_Itype (Typ));
4673 Check_Restriction (No_Coextensions, N);
4675 -- Ada 2012 AI05-0052: If the designated type of the allocator
4676 -- is limited, then the allocator shall not be used to define
4677 -- the value of an access discriminant unless the discriminated
4678 -- type is immutably limited.
4680 if Ada_Version >= Ada_2012
4681 and then Is_Limited_Type (Desig_T)
4682 and then not Is_Limited_View (Scope (Discr))
4685 ("only immutably limited types can have anonymous "
4686 & "access discriminants designating a limited type", N);
4690 -- Avoid marking an allocator as a dynamic coextension if it is
4691 -- within a static construct.
4693 if not Is_Static_Coextension (N) then
4694 Set_Is_Dynamic_Coextension (N);
4697 -- Cleanup for potential static coextensions
4700 Set_Is_Dynamic_Coextension (N, False);
4701 Set_Is_Static_Coextension (N, False);
4705 -- Report a simple error: if the designated object is a local task,
4706 -- its body has not been seen yet, and its activation will fail an
4707 -- elaboration check.
4709 if Is_Task_Type (Desig_T)
4710 and then Scope (Base_Type (Desig_T)) = Current_Scope
4711 and then Is_Compilation_Unit (Current_Scope)
4712 and then Ekind (Current_Scope) = E_Package
4713 and then not In_Package_Body (Current_Scope)
4715 Error_Msg_Warn := SPARK_Mode /= On;
4716 Error_Msg_N ("cannot activate task before body seen<<", N);
4717 Error_Msg_N ("\Program_Error [<<", N);
4720 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
4721 -- type with a task component on a subpool. This action must raise
4722 -- Program_Error at runtime.
4724 if Ada_Version >= Ada_2012
4725 and then Nkind (N) = N_Allocator
4726 and then Present (Subpool_Handle_Name (N))
4727 and then Has_Task (Desig_T)
4729 Error_Msg_Warn := SPARK_Mode /= On;
4730 Error_Msg_N ("cannot allocate task on subpool<<", N);
4731 Error_Msg_N ("\Program_Error [<<", N);
4734 Make_Raise_Program_Error (Sloc (N),
4735 Reason => PE_Explicit_Raise));
4738 end Resolve_Allocator;
4740 ---------------------------
4741 -- Resolve_Arithmetic_Op --
4742 ---------------------------
4744 -- Used for resolving all arithmetic operators except exponentiation
4746 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4747 L : constant Node_Id := Left_Opnd (N);
4748 R : constant Node_Id := Right_Opnd (N);
4749 TL : constant Entity_Id := Base_Type (Etype (L));
4750 TR : constant Entity_Id := Base_Type (Etype (R));
4754 B_Typ : constant Entity_Id := Base_Type (Typ);
4755 -- We do the resolution using the base type, because intermediate values
4756 -- in expressions always are of the base type, not a subtype of it.
4758 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4759 -- Returns True if N is in a context that expects "any real type"
4761 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4762 -- Return True iff given type is Integer or universal real/integer
4764 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4765 -- Choose type of integer literal in fixed-point operation to conform
4766 -- to available fixed-point type. T is the type of the other operand,
4767 -- which is needed to determine the expected type of N.
4769 procedure Set_Operand_Type (N : Node_Id);
4770 -- Set operand type to T if universal
4772 -------------------------------
4773 -- Expected_Type_Is_Any_Real --
4774 -------------------------------
4776 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4778 -- N is the expression after "delta" in a fixed_point_definition;
4781 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4782 N_Decimal_Fixed_Point_Definition,
4784 -- N is one of the bounds in a real_range_specification;
4787 N_Real_Range_Specification,
4789 -- N is the expression of a delta_constraint;
4792 N_Delta_Constraint);
4793 end Expected_Type_Is_Any_Real;
4795 -----------------------------
4796 -- Is_Integer_Or_Universal --
4797 -----------------------------
4799 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4801 Index : Interp_Index;
4805 if not Is_Overloaded (N) then
4807 return Base_Type (T) = Base_Type (Standard_Integer)
4808 or else T = Universal_Integer
4809 or else T = Universal_Real;
4811 Get_First_Interp (N, Index, It);
4812 while Present (It.Typ) loop
4813 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4814 or else It.Typ = Universal_Integer
4815 or else It.Typ = Universal_Real
4820 Get_Next_Interp (Index, It);
4825 end Is_Integer_Or_Universal;
4827 ----------------------------
4828 -- Set_Mixed_Mode_Operand --
4829 ----------------------------
4831 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4832 Index : Interp_Index;
4836 if Universal_Interpretation (N) = Universal_Integer then
4838 -- A universal integer literal is resolved as standard integer
4839 -- except in the case of a fixed-point result, where we leave it
4840 -- as universal (to be handled by Exp_Fixd later on)
4842 if Is_Fixed_Point_Type (T) then
4843 Resolve (N, Universal_Integer);
4845 Resolve (N, Standard_Integer);
4848 elsif Universal_Interpretation (N) = Universal_Real
4849 and then (T = Base_Type (Standard_Integer)
4850 or else T = Universal_Integer
4851 or else T = Universal_Real)
4853 -- A universal real can appear in a fixed-type context. We resolve
4854 -- the literal with that context, even though this might raise an
4855 -- exception prematurely (the other operand may be zero).
4859 elsif Etype (N) = Base_Type (Standard_Integer)
4860 and then T = Universal_Real
4861 and then Is_Overloaded (N)
4863 -- Integer arg in mixed-mode operation. Resolve with universal
4864 -- type, in case preference rule must be applied.
4866 Resolve (N, Universal_Integer);
4869 and then B_Typ /= Universal_Fixed
4871 -- Not a mixed-mode operation, resolve with context
4875 elsif Etype (N) = Any_Fixed then
4877 -- N may itself be a mixed-mode operation, so use context type
4881 elsif Is_Fixed_Point_Type (T)
4882 and then B_Typ = Universal_Fixed
4883 and then Is_Overloaded (N)
4885 -- Must be (fixed * fixed) operation, operand must have one
4886 -- compatible interpretation.
4888 Resolve (N, Any_Fixed);
4890 elsif Is_Fixed_Point_Type (B_Typ)
4891 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
4892 and then Is_Overloaded (N)
4894 -- C * F(X) in a fixed context, where C is a real literal or a
4895 -- fixed-point expression. F must have either a fixed type
4896 -- interpretation or an integer interpretation, but not both.
4898 Get_First_Interp (N, Index, It);
4899 while Present (It.Typ) loop
4900 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4901 if Analyzed (N) then
4902 Error_Msg_N ("ambiguous operand in fixed operation", N);
4904 Resolve (N, Standard_Integer);
4907 elsif Is_Fixed_Point_Type (It.Typ) then
4908 if Analyzed (N) then
4909 Error_Msg_N ("ambiguous operand in fixed operation", N);
4911 Resolve (N, It.Typ);
4915 Get_Next_Interp (Index, It);
4918 -- Reanalyze the literal with the fixed type of the context. If
4919 -- context is Universal_Fixed, we are within a conversion, leave
4920 -- the literal as a universal real because there is no usable
4921 -- fixed type, and the target of the conversion plays no role in
4935 if B_Typ = Universal_Fixed
4936 and then Nkind (Op2) = N_Real_Literal
4938 T2 := Universal_Real;
4943 Set_Analyzed (Op2, False);
4950 end Set_Mixed_Mode_Operand;
4952 ----------------------
4953 -- Set_Operand_Type --
4954 ----------------------
4956 procedure Set_Operand_Type (N : Node_Id) is
4958 if Etype (N) = Universal_Integer
4959 or else Etype (N) = Universal_Real
4963 end Set_Operand_Type;
4965 -- Start of processing for Resolve_Arithmetic_Op
4968 if Comes_From_Source (N)
4969 and then Ekind (Entity (N)) = E_Function
4970 and then Is_Imported (Entity (N))
4971 and then Is_Intrinsic_Subprogram (Entity (N))
4973 Resolve_Intrinsic_Operator (N, Typ);
4976 -- Special-case for mixed-mode universal expressions or fixed point type
4977 -- operation: each argument is resolved separately. The same treatment
4978 -- is required if one of the operands of a fixed point operation is
4979 -- universal real, since in this case we don't do a conversion to a
4980 -- specific fixed-point type (instead the expander handles the case).
4982 -- Set the type of the node to its universal interpretation because
4983 -- legality checks on an exponentiation operand need the context.
4985 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4986 and then Present (Universal_Interpretation (L))
4987 and then Present (Universal_Interpretation (R))
4989 Set_Etype (N, B_Typ);
4990 Resolve (L, Universal_Interpretation (L));
4991 Resolve (R, Universal_Interpretation (R));
4993 elsif (B_Typ = Universal_Real
4994 or else Etype (N) = Universal_Fixed
4995 or else (Etype (N) = Any_Fixed
4996 and then Is_Fixed_Point_Type (B_Typ))
4997 or else (Is_Fixed_Point_Type (B_Typ)
4998 and then (Is_Integer_Or_Universal (L)
5000 Is_Integer_Or_Universal (R))))
5001 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5003 if TL = Universal_Integer or else TR = Universal_Integer then
5004 Check_For_Visible_Operator (N, B_Typ);
5007 -- If context is a fixed type and one operand is integer, the other
5008 -- is resolved with the type of the context.
5010 if Is_Fixed_Point_Type (B_Typ)
5011 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5012 or else TL = Universal_Integer)
5017 elsif Is_Fixed_Point_Type (B_Typ)
5018 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5019 or else TR = Universal_Integer)
5025 Set_Mixed_Mode_Operand (L, TR);
5026 Set_Mixed_Mode_Operand (R, TL);
5029 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5030 -- multiplying operators from being used when the expected type is
5031 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5032 -- some cases where the expected type is actually Any_Real;
5033 -- Expected_Type_Is_Any_Real takes care of that case.
5035 if Etype (N) = Universal_Fixed
5036 or else Etype (N) = Any_Fixed
5038 if B_Typ = Universal_Fixed
5039 and then not Expected_Type_Is_Any_Real (N)
5040 and then not Nkind_In (Parent (N), N_Type_Conversion,
5041 N_Unchecked_Type_Conversion)
5043 Error_Msg_N ("type cannot be determined from context!", N);
5044 Error_Msg_N ("\explicit conversion to result type required", N);
5046 Set_Etype (L, Any_Type);
5047 Set_Etype (R, Any_Type);
5050 if Ada_Version = Ada_83
5051 and then Etype (N) = Universal_Fixed
5053 Nkind_In (Parent (N), N_Type_Conversion,
5054 N_Unchecked_Type_Conversion)
5057 ("(Ada 83) fixed-point operation "
5058 & "needs explicit conversion", N);
5061 -- The expected type is "any real type" in contexts like
5063 -- type T is delta <universal_fixed-expression> ...
5065 -- in which case we need to set the type to Universal_Real
5066 -- so that static expression evaluation will work properly.
5068 if Expected_Type_Is_Any_Real (N) then
5069 Set_Etype (N, Universal_Real);
5071 Set_Etype (N, B_Typ);
5075 elsif Is_Fixed_Point_Type (B_Typ)
5076 and then (Is_Integer_Or_Universal (L)
5077 or else Nkind (L) = N_Real_Literal
5078 or else Nkind (R) = N_Real_Literal
5079 or else Is_Integer_Or_Universal (R))
5081 Set_Etype (N, B_Typ);
5083 elsif Etype (N) = Any_Fixed then
5085 -- If no previous errors, this is only possible if one operand is
5086 -- overloaded and the context is universal. Resolve as such.
5088 Set_Etype (N, B_Typ);
5092 if (TL = Universal_Integer or else TL = Universal_Real)
5094 (TR = Universal_Integer or else TR = Universal_Real)
5096 Check_For_Visible_Operator (N, B_Typ);
5099 -- If the context is Universal_Fixed and the operands are also
5100 -- universal fixed, this is an error, unless there is only one
5101 -- applicable fixed_point type (usually Duration).
5103 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5104 T := Unique_Fixed_Point_Type (N);
5106 if T = Any_Type then
5119 -- If one of the arguments was resolved to a non-universal type.
5120 -- label the result of the operation itself with the same type.
5121 -- Do the same for the universal argument, if any.
5123 T := Intersect_Types (L, R);
5124 Set_Etype (N, Base_Type (T));
5125 Set_Operand_Type (L);
5126 Set_Operand_Type (R);
5129 Generate_Operator_Reference (N, Typ);
5130 Analyze_Dimension (N);
5131 Eval_Arithmetic_Op (N);
5133 -- In SPARK, a multiplication or division with operands of fixed point
5134 -- types shall be qualified or explicitly converted to identify the
5137 if (Is_Fixed_Point_Type (Etype (L))
5138 or else Is_Fixed_Point_Type (Etype (R)))
5139 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5141 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5143 Check_SPARK_Restriction
5144 ("operation should be qualified or explicitly converted", N);
5147 -- Set overflow and division checking bit
5149 if Nkind (N) in N_Op then
5150 if not Overflow_Checks_Suppressed (Etype (N)) then
5151 Enable_Overflow_Check (N);
5154 -- Give warning if explicit division by zero
5156 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5157 and then not Division_Checks_Suppressed (Etype (N))
5159 Rop := Right_Opnd (N);
5161 if Compile_Time_Known_Value (Rop)
5162 and then ((Is_Integer_Type (Etype (Rop))
5163 and then Expr_Value (Rop) = Uint_0)
5165 (Is_Real_Type (Etype (Rop))
5166 and then Expr_Value_R (Rop) = Ureal_0))
5168 -- Specialize the warning message according to the operation.
5169 -- The following warnings are for the case
5174 -- For division, we have two cases, for float division
5175 -- of an unconstrained float type, on a machine where
5176 -- Machine_Overflows is false, we don't get an exception
5177 -- at run-time, but rather an infinity or Nan. The Nan
5178 -- case is pretty obscure, so just warn about infinities.
5180 if Is_Floating_Point_Type (Typ)
5181 and then not Is_Constrained (Typ)
5182 and then not Machine_Overflows_On_Target
5185 ("float division by zero, may generate "
5186 & "'+'/'- infinity??", Right_Opnd (N));
5188 -- For all other cases, we get a Constraint_Error
5191 Apply_Compile_Time_Constraint_Error
5192 (N, "division by zero??", CE_Divide_By_Zero,
5193 Loc => Sloc (Right_Opnd (N)));
5197 Apply_Compile_Time_Constraint_Error
5198 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5199 Loc => Sloc (Right_Opnd (N)));
5202 Apply_Compile_Time_Constraint_Error
5203 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5204 Loc => Sloc (Right_Opnd (N)));
5206 -- Division by zero can only happen with division, rem,
5207 -- and mod operations.
5210 raise Program_Error;
5213 -- Otherwise just set the flag to check at run time
5216 Activate_Division_Check (N);
5220 -- If Restriction No_Implicit_Conditionals is active, then it is
5221 -- violated if either operand can be negative for mod, or for rem
5222 -- if both operands can be negative.
5224 if Restriction_Check_Required (No_Implicit_Conditionals)
5225 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5234 -- Set if corresponding operand might be negative
5238 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5239 LNeg := (not OK) or else Lo < 0;
5242 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5243 RNeg := (not OK) or else Lo < 0;
5245 -- Check if we will be generating conditionals. There are two
5246 -- cases where that can happen, first for REM, the only case
5247 -- is largest negative integer mod -1, where the division can
5248 -- overflow, but we still have to give the right result. The
5249 -- front end generates a test for this annoying case. Here we
5250 -- just test if both operands can be negative (that's what the
5251 -- expander does, so we match its logic here).
5253 -- The second case is mod where either operand can be negative.
5254 -- In this case, the back end has to generate additional tests.
5256 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5258 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5260 Check_Restriction (No_Implicit_Conditionals, N);
5266 Check_Unset_Reference (L);
5267 Check_Unset_Reference (R);
5268 Check_Function_Writable_Actuals (N);
5269 end Resolve_Arithmetic_Op;
5275 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5276 Loc : constant Source_Ptr := Sloc (N);
5277 Subp : constant Node_Id := Name (N);
5285 function Same_Or_Aliased_Subprograms
5287 E : Entity_Id) return Boolean;
5288 -- Returns True if the subprogram entity S is the same as E or else
5289 -- S is an alias of E.
5291 ---------------------------------
5292 -- Same_Or_Aliased_Subprograms --
5293 ---------------------------------
5295 function Same_Or_Aliased_Subprograms
5297 E : Entity_Id) return Boolean
5299 Subp_Alias : constant Entity_Id := Alias (S);
5301 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5302 end Same_Or_Aliased_Subprograms;
5304 -- Start of processing for Resolve_Call
5307 -- The context imposes a unique interpretation with type Typ on a
5308 -- procedure or function call. Find the entity of the subprogram that
5309 -- yields the expected type, and propagate the corresponding formal
5310 -- constraints on the actuals. The caller has established that an
5311 -- interpretation exists, and emitted an error if not unique.
5313 -- First deal with the case of a call to an access-to-subprogram,
5314 -- dereference made explicit in Analyze_Call.
5316 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5317 if not Is_Overloaded (Subp) then
5318 Nam := Etype (Subp);
5321 -- Find the interpretation whose type (a subprogram type) has a
5322 -- return type that is compatible with the context. Analysis of
5323 -- the node has established that one exists.
5327 Get_First_Interp (Subp, I, It);
5328 while Present (It.Typ) loop
5329 if Covers (Typ, Etype (It.Typ)) then
5334 Get_Next_Interp (I, It);
5338 raise Program_Error;
5342 -- If the prefix is not an entity, then resolve it
5344 if not Is_Entity_Name (Subp) then
5345 Resolve (Subp, Nam);
5348 -- For an indirect call, we always invalidate checks, since we do not
5349 -- know whether the subprogram is local or global. Yes we could do
5350 -- better here, e.g. by knowing that there are no local subprograms,
5351 -- but it does not seem worth the effort. Similarly, we kill all
5352 -- knowledge of current constant values.
5354 Kill_Current_Values;
5356 -- If this is a procedure call which is really an entry call, do
5357 -- the conversion of the procedure call to an entry call. Protected
5358 -- operations use the same circuitry because the name in the call
5359 -- can be an arbitrary expression with special resolution rules.
5361 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5362 or else (Is_Entity_Name (Subp)
5363 and then Ekind (Entity (Subp)) = E_Entry)
5365 Resolve_Entry_Call (N, Typ);
5366 Check_Elab_Call (N);
5368 -- Kill checks and constant values, as above for indirect case
5369 -- Who knows what happens when another task is activated?
5371 Kill_Current_Values;
5374 -- Normal subprogram call with name established in Resolve
5376 elsif not (Is_Type (Entity (Subp))) then
5377 Nam := Entity (Subp);
5378 Set_Entity_With_Checks (Subp, Nam);
5380 -- Otherwise we must have the case of an overloaded call
5383 pragma Assert (Is_Overloaded (Subp));
5385 -- Initialize Nam to prevent warning (we know it will be assigned
5386 -- in the loop below, but the compiler does not know that).
5390 Get_First_Interp (Subp, I, It);
5391 while Present (It.Typ) loop
5392 if Covers (Typ, It.Typ) then
5394 Set_Entity_With_Checks (Subp, Nam);
5398 Get_Next_Interp (I, It);
5402 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5403 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5404 and then Nkind (Subp) /= N_Explicit_Dereference
5405 and then Present (Parameter_Associations (N))
5407 -- The prefix is a parameterless function call that returns an access
5408 -- to subprogram. If parameters are present in the current call, add
5409 -- add an explicit dereference. We use the base type here because
5410 -- within an instance these may be subtypes.
5412 -- The dereference is added either in Analyze_Call or here. Should
5413 -- be consolidated ???
5415 Set_Is_Overloaded (Subp, False);
5416 Set_Etype (Subp, Etype (Nam));
5417 Insert_Explicit_Dereference (Subp);
5418 Nam := Designated_Type (Etype (Nam));
5419 Resolve (Subp, Nam);
5422 -- Check that a call to Current_Task does not occur in an entry body
5424 if Is_RTE (Nam, RE_Current_Task) then
5433 -- Exclude calls that occur within the default of a formal
5434 -- parameter of the entry, since those are evaluated outside
5437 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5439 if Nkind (P) = N_Entry_Body
5440 or else (Nkind (P) = N_Subprogram_Body
5441 and then Is_Entry_Barrier_Function (P))
5444 Error_Msg_Warn := SPARK_Mode /= On;
5446 ("& should not be used in entry body (RM C.7(17))<<",
5448 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5450 Make_Raise_Program_Error (Loc,
5451 Reason => PE_Current_Task_In_Entry_Body));
5452 Set_Etype (N, Rtype);
5459 -- Check that a procedure call does not occur in the context of the
5460 -- entry call statement of a conditional or timed entry call. Note that
5461 -- the case of a call to a subprogram renaming of an entry will also be
5462 -- rejected. The test for N not being an N_Entry_Call_Statement is
5463 -- defensive, covering the possibility that the processing of entry
5464 -- calls might reach this point due to later modifications of the code
5467 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5468 and then Nkind (N) /= N_Entry_Call_Statement
5469 and then Entry_Call_Statement (Parent (N)) = N
5471 if Ada_Version < Ada_2005 then
5472 Error_Msg_N ("entry call required in select statement", N);
5474 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5475 -- for a procedure_or_entry_call, the procedure_name or
5476 -- procedure_prefix of the procedure_call_statement shall denote
5477 -- an entry renamed by a procedure, or (a view of) a primitive
5478 -- subprogram of a limited interface whose first parameter is
5479 -- a controlling parameter.
5481 elsif Nkind (N) = N_Procedure_Call_Statement
5482 and then not Is_Renamed_Entry (Nam)
5483 and then not Is_Controlling_Limited_Procedure (Nam)
5486 ("entry call or dispatching primitive of interface required", N);
5490 -- If the SPARK_05 restriction is active, we are not allowed
5491 -- to have a call to a subprogram before we see its completion.
5493 if not Has_Completion (Nam)
5494 and then Restriction_Check_Required (SPARK_05)
5496 -- Don't flag strange internal calls
5498 and then Comes_From_Source (N)
5499 and then Comes_From_Source (Nam)
5501 -- Only flag calls in extended main source
5503 and then In_Extended_Main_Source_Unit (Nam)
5504 and then In_Extended_Main_Source_Unit (N)
5506 -- Exclude enumeration literals from this processing
5508 and then Ekind (Nam) /= E_Enumeration_Literal
5510 Check_SPARK_Restriction
5511 ("call to subprogram cannot appear before its body", N);
5514 -- Check that this is not a call to a protected procedure or entry from
5515 -- within a protected function.
5517 Check_Internal_Protected_Use (N, Nam);
5519 -- Freeze the subprogram name if not in a spec-expression. Note that
5520 -- we freeze procedure calls as well as function calls. Procedure calls
5521 -- are not frozen according to the rules (RM 13.14(14)) because it is
5522 -- impossible to have a procedure call to a non-frozen procedure in
5523 -- pure Ada, but in the code that we generate in the expander, this
5524 -- rule needs extending because we can generate procedure calls that
5527 -- In Ada 2012, expression functions may be called within pre/post
5528 -- conditions of subsequent functions or expression functions. Such
5529 -- calls do not freeze when they appear within generated bodies,
5530 -- (including the body of another expression function) which would
5531 -- place the freeze node in the wrong scope. An expression function
5532 -- is frozen in the usual fashion, by the appearance of a real body,
5533 -- or at the end of a declarative part.
5535 if Is_Entity_Name (Subp) and then not In_Spec_Expression
5536 and then not Is_Expression_Function (Current_Scope)
5538 (not Is_Expression_Function (Entity (Subp))
5539 or else Scope (Entity (Subp)) = Current_Scope)
5541 Freeze_Expression (Subp);
5544 -- For a predefined operator, the type of the result is the type imposed
5545 -- by context, except for a predefined operation on universal fixed.
5546 -- Otherwise The type of the call is the type returned by the subprogram
5549 if Is_Predefined_Op (Nam) then
5550 if Etype (N) /= Universal_Fixed then
5554 -- If the subprogram returns an array type, and the context requires the
5555 -- component type of that array type, the node is really an indexing of
5556 -- the parameterless call. Resolve as such. A pathological case occurs
5557 -- when the type of the component is an access to the array type. In
5558 -- this case the call is truly ambiguous.
5560 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5562 ((Is_Array_Type (Etype (Nam))
5563 and then Covers (Typ, Component_Type (Etype (Nam))))
5565 (Is_Access_Type (Etype (Nam))
5566 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5568 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5571 Index_Node : Node_Id;
5573 Ret_Type : constant Entity_Id := Etype (Nam);
5576 if Is_Access_Type (Ret_Type)
5577 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5580 ("cannot disambiguate function call and indexing", N);
5582 New_Subp := Relocate_Node (Subp);
5584 -- The called entity may be an explicit dereference, in which
5585 -- case there is no entity to set.
5587 if Nkind (New_Subp) /= N_Explicit_Dereference then
5588 Set_Entity (Subp, Nam);
5591 if (Is_Array_Type (Ret_Type)
5592 and then Component_Type (Ret_Type) /= Any_Type)
5594 (Is_Access_Type (Ret_Type)
5596 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5598 if Needs_No_Actuals (Nam) then
5600 -- Indexed call to a parameterless function
5603 Make_Indexed_Component (Loc,
5605 Make_Function_Call (Loc,
5607 Expressions => Parameter_Associations (N));
5609 -- An Ada 2005 prefixed call to a primitive operation
5610 -- whose first parameter is the prefix. This prefix was
5611 -- prepended to the parameter list, which is actually a
5612 -- list of indexes. Remove the prefix in order to build
5613 -- the proper indexed component.
5616 Make_Indexed_Component (Loc,
5618 Make_Function_Call (Loc,
5620 Parameter_Associations =>
5622 (Remove_Head (Parameter_Associations (N)))),
5623 Expressions => Parameter_Associations (N));
5626 -- Preserve the parenthesis count of the node
5628 Set_Paren_Count (Index_Node, Paren_Count (N));
5630 -- Since we are correcting a node classification error made
5631 -- by the parser, we call Replace rather than Rewrite.
5633 Replace (N, Index_Node);
5635 Set_Etype (Prefix (N), Ret_Type);
5637 Resolve_Indexed_Component (N, Typ);
5638 Check_Elab_Call (Prefix (N));
5646 Set_Etype (N, Etype (Nam));
5649 -- In the case where the call is to an overloaded subprogram, Analyze
5650 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5651 -- such a case Normalize_Actuals needs to be called once more to order
5652 -- the actuals correctly. Otherwise the call will have the ordering
5653 -- given by the last overloaded subprogram whether this is the correct
5654 -- one being called or not.
5656 if Is_Overloaded (Subp) then
5657 Normalize_Actuals (N, Nam, False, Norm_OK);
5658 pragma Assert (Norm_OK);
5661 -- In any case, call is fully resolved now. Reset Overload flag, to
5662 -- prevent subsequent overload resolution if node is analyzed again
5664 Set_Is_Overloaded (Subp, False);
5665 Set_Is_Overloaded (N, False);
5667 -- If we are calling the current subprogram from immediately within its
5668 -- body, then that is the case where we can sometimes detect cases of
5669 -- infinite recursion statically. Do not try this in case restriction
5670 -- No_Recursion is in effect anyway, and do it only for source calls.
5672 if Comes_From_Source (N) then
5673 Scop := Current_Scope;
5675 -- Check violation of SPARK_05 restriction which does not permit
5676 -- a subprogram body to contain a call to the subprogram directly.
5678 if Restriction_Check_Required (SPARK_05)
5679 and then Same_Or_Aliased_Subprograms (Nam, Scop)
5681 Check_SPARK_Restriction
5682 ("subprogram may not contain direct call to itself", N);
5685 -- Issue warning for possible infinite recursion in the absence
5686 -- of the No_Recursion restriction.
5688 if Same_Or_Aliased_Subprograms (Nam, Scop)
5689 and then not Restriction_Active (No_Recursion)
5690 and then Check_Infinite_Recursion (N)
5692 -- Here we detected and flagged an infinite recursion, so we do
5693 -- not need to test the case below for further warnings. Also we
5694 -- are all done if we now have a raise SE node.
5696 if Nkind (N) = N_Raise_Storage_Error then
5700 -- If call is to immediately containing subprogram, then check for
5701 -- the case of a possible run-time detectable infinite recursion.
5704 Scope_Loop : while Scop /= Standard_Standard loop
5705 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5707 -- Although in general case, recursion is not statically
5708 -- checkable, the case of calling an immediately containing
5709 -- subprogram is easy to catch.
5711 Check_Restriction (No_Recursion, N);
5713 -- If the recursive call is to a parameterless subprogram,
5714 -- then even if we can't statically detect infinite
5715 -- recursion, this is pretty suspicious, and we output a
5716 -- warning. Furthermore, we will try later to detect some
5717 -- cases here at run time by expanding checking code (see
5718 -- Detect_Infinite_Recursion in package Exp_Ch6).
5720 -- If the recursive call is within a handler, do not emit a
5721 -- warning, because this is a common idiom: loop until input
5722 -- is correct, catch illegal input in handler and restart.
5724 if No (First_Formal (Nam))
5725 and then Etype (Nam) = Standard_Void_Type
5726 and then not Error_Posted (N)
5727 and then Nkind (Parent (N)) /= N_Exception_Handler
5729 -- For the case of a procedure call. We give the message
5730 -- only if the call is the first statement in a sequence
5731 -- of statements, or if all previous statements are
5732 -- simple assignments. This is simply a heuristic to
5733 -- decrease false positives, without losing too many good
5734 -- warnings. The idea is that these previous statements
5735 -- may affect global variables the procedure depends on.
5736 -- We also exclude raise statements, that may arise from
5737 -- constraint checks and are probably unrelated to the
5738 -- intended control flow.
5740 if Nkind (N) = N_Procedure_Call_Statement
5741 and then Is_List_Member (N)
5747 while Present (P) loop
5749 N_Assignment_Statement,
5750 N_Raise_Constraint_Error)
5760 -- Do not give warning if we are in a conditional context
5763 K : constant Node_Kind := Nkind (Parent (N));
5765 if (K = N_Loop_Statement
5766 and then Present (Iteration_Scheme (Parent (N))))
5767 or else K = N_If_Statement
5768 or else K = N_Elsif_Part
5769 or else K = N_Case_Statement_Alternative
5775 -- Here warning is to be issued
5777 Set_Has_Recursive_Call (Nam);
5778 Error_Msg_Warn := SPARK_Mode /= On;
5779 Error_Msg_N ("possible infinite recursion<<!", N);
5780 Error_Msg_N ("\Storage_Error ]<<!", N);
5786 Scop := Scope (Scop);
5787 end loop Scope_Loop;
5791 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5793 Check_Obsolescent_2005_Entity (Nam, Subp);
5795 -- If subprogram name is a predefined operator, it was given in
5796 -- functional notation. Replace call node with operator node, so
5797 -- that actuals can be resolved appropriately.
5799 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5800 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5803 elsif Present (Alias (Nam))
5804 and then Is_Predefined_Op (Alias (Nam))
5806 Resolve_Actuals (N, Nam);
5807 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5811 -- Create a transient scope if the resulting type requires it
5813 -- There are several notable exceptions:
5815 -- a) In init procs, the transient scope overhead is not needed, and is
5816 -- even incorrect when the call is a nested initialization call for a
5817 -- component whose expansion may generate adjust calls. However, if the
5818 -- call is some other procedure call within an initialization procedure
5819 -- (for example a call to Create_Task in the init_proc of the task
5820 -- run-time record) a transient scope must be created around this call.
5822 -- b) Enumeration literal pseudo-calls need no transient scope
5824 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5825 -- functions) do not use the secondary stack even though the return
5826 -- type may be unconstrained.
5828 -- d) Calls to a build-in-place function, since such functions may
5829 -- allocate their result directly in a target object, and cases where
5830 -- the result does get allocated in the secondary stack are checked for
5831 -- within the specialized Exp_Ch6 procedures for expanding those
5832 -- build-in-place calls.
5834 -- e) If the subprogram is marked Inline_Always, then even if it returns
5835 -- an unconstrained type the call does not require use of the secondary
5836 -- stack. However, inlining will only take place if the body to inline
5837 -- is already present. It may not be available if e.g. the subprogram is
5838 -- declared in a child instance.
5840 -- If this is an initialization call for a type whose construction
5841 -- uses the secondary stack, and it is not a nested call to initialize
5842 -- a component, we do need to create a transient scope for it. We
5843 -- check for this by traversing the type in Check_Initialization_Call.
5846 and then Has_Pragma_Inline_Always (Nam)
5847 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5848 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5849 and then not Debug_Flag_Dot_K
5853 elsif Is_Inlined (Nam)
5854 and then Has_Pragma_Inline (Nam)
5855 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5856 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5857 and then Debug_Flag_Dot_K
5861 elsif Ekind (Nam) = E_Enumeration_Literal
5862 or else Is_Build_In_Place_Function (Nam)
5863 or else Is_Intrinsic_Subprogram (Nam)
5867 elsif Expander_Active
5868 and then Is_Type (Etype (Nam))
5869 and then Requires_Transient_Scope (Etype (Nam))
5871 (not Within_Init_Proc
5873 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5875 Establish_Transient_Scope (N, Sec_Stack => True);
5877 -- If the call appears within the bounds of a loop, it will
5878 -- be rewritten and reanalyzed, nothing left to do here.
5880 if Nkind (N) /= N_Function_Call then
5884 elsif Is_Init_Proc (Nam)
5885 and then not Within_Init_Proc
5887 Check_Initialization_Call (N, Nam);
5890 -- A protected function cannot be called within the definition of the
5891 -- enclosing protected type.
5893 if Is_Protected_Type (Scope (Nam))
5894 and then In_Open_Scopes (Scope (Nam))
5895 and then not Has_Completion (Scope (Nam))
5898 ("& cannot be called before end of protected definition", N, Nam);
5901 -- Propagate interpretation to actuals, and add default expressions
5904 if Present (First_Formal (Nam)) then
5905 Resolve_Actuals (N, Nam);
5907 -- Overloaded literals are rewritten as function calls, for purpose of
5908 -- resolution. After resolution, we can replace the call with the
5911 elsif Ekind (Nam) = E_Enumeration_Literal then
5912 Copy_Node (Subp, N);
5913 Resolve_Entity_Name (N, Typ);
5915 -- Avoid validation, since it is a static function call
5917 Generate_Reference (Nam, Subp);
5921 -- If the subprogram is not global, then kill all saved values and
5922 -- checks. This is a bit conservative, since in many cases we could do
5923 -- better, but it is not worth the effort. Similarly, we kill constant
5924 -- values. However we do not need to do this for internal entities
5925 -- (unless they are inherited user-defined subprograms), since they
5926 -- are not in the business of molesting local values.
5928 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5929 -- kill all checks and values for calls to global subprograms. This
5930 -- takes care of the case where an access to a local subprogram is
5931 -- taken, and could be passed directly or indirectly and then called
5932 -- from almost any context.
5934 -- Note: we do not do this step till after resolving the actuals. That
5935 -- way we still take advantage of the current value information while
5936 -- scanning the actuals.
5938 -- We suppress killing values if we are processing the nodes associated
5939 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5940 -- type kills all the values as part of analyzing the code that
5941 -- initializes the dispatch tables.
5943 if Inside_Freezing_Actions = 0
5944 and then (not Is_Library_Level_Entity (Nam)
5945 or else Suppress_Value_Tracking_On_Call
5946 (Nearest_Dynamic_Scope (Current_Scope)))
5947 and then (Comes_From_Source (Nam)
5948 or else (Present (Alias (Nam))
5949 and then Comes_From_Source (Alias (Nam))))
5951 Kill_Current_Values;
5954 -- If we are warning about unread OUT parameters, this is the place to
5955 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5956 -- after the above call to Kill_Current_Values (since that call clears
5957 -- the Last_Assignment field of all local variables).
5959 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5960 and then Comes_From_Source (N)
5961 and then In_Extended_Main_Source_Unit (N)
5968 F := First_Formal (Nam);
5969 A := First_Actual (N);
5970 while Present (F) and then Present (A) loop
5971 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
5972 and then Warn_On_Modified_As_Out_Parameter (F)
5973 and then Is_Entity_Name (A)
5974 and then Present (Entity (A))
5975 and then Comes_From_Source (N)
5976 and then Safe_To_Capture_Value (N, Entity (A))
5978 Set_Last_Assignment (Entity (A), A);
5987 -- If the subprogram is a primitive operation, check whether or not
5988 -- it is a correct dispatching call.
5990 if Is_Overloadable (Nam)
5991 and then Is_Dispatching_Operation (Nam)
5993 Check_Dispatching_Call (N);
5995 elsif Ekind (Nam) /= E_Subprogram_Type
5996 and then Is_Abstract_Subprogram (Nam)
5997 and then not In_Instance
5999 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6002 -- If this is a dispatching call, generate the appropriate reference,
6003 -- for better source navigation in GPS.
6005 if Is_Overloadable (Nam)
6006 and then Present (Controlling_Argument (N))
6008 Generate_Reference (Nam, Subp, 'R');
6010 -- Normal case, not a dispatching call: generate a call reference
6013 Generate_Reference (Nam, Subp, 's');
6016 if Is_Intrinsic_Subprogram (Nam) then
6017 Check_Intrinsic_Call (N);
6020 -- Check for violation of restriction No_Specific_Termination_Handlers
6021 -- and warn on a potentially blocking call to Abort_Task.
6023 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6024 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6026 Is_RTE (Nam, RE_Specific_Handler))
6028 Check_Restriction (No_Specific_Termination_Handlers, N);
6030 elsif Is_RTE (Nam, RE_Abort_Task) then
6031 Check_Potentially_Blocking_Operation (N);
6034 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6035 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6036 -- need to check the second argument to determine whether it is an
6037 -- absolute or relative timing event.
6039 if Restriction_Check_Required (No_Relative_Delay)
6040 and then Is_RTE (Nam, RE_Set_Handler)
6041 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6043 Check_Restriction (No_Relative_Delay, N);
6046 -- Issue an error for a call to an eliminated subprogram. This routine
6047 -- will not perform the check if the call appears within a default
6050 Check_For_Eliminated_Subprogram (Subp, Nam);
6052 -- In formal mode, the primitive operations of a tagged type or type
6053 -- extension do not include functions that return the tagged type.
6055 if Nkind (N) = N_Function_Call
6056 and then Is_Tagged_Type (Etype (N))
6057 and then Is_Entity_Name (Name (N))
6058 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6060 Check_SPARK_Restriction ("function not inherited", N);
6063 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6064 -- class-wide and the call dispatches on result in a context that does
6065 -- not provide a tag, the call raises Program_Error.
6067 if Nkind (N) = N_Function_Call
6068 and then In_Instance
6069 and then Is_Generic_Actual_Type (Typ)
6070 and then Is_Class_Wide_Type (Typ)
6071 and then Has_Controlling_Result (Nam)
6072 and then Nkind (Parent (N)) = N_Object_Declaration
6074 -- Verify that none of the formals are controlling
6077 Call_OK : Boolean := False;
6081 F := First_Formal (Nam);
6082 while Present (F) loop
6083 if Is_Controlling_Formal (F) then
6092 Error_Msg_Warn := SPARK_Mode /= On;
6093 Error_Msg_N ("!cannot determine tag of result<<", N);
6094 Error_Msg_N ("\Program_Error [<<!", N);
6096 Make_Raise_Program_Error (Sloc (N),
6097 Reason => PE_Explicit_Raise));
6102 -- Check the dimensions of the actuals in the call. For function calls,
6103 -- propagate the dimensions from the returned type to N.
6105 Analyze_Dimension_Call (N, Nam);
6107 -- All done, evaluate call and deal with elaboration issues
6110 Check_Elab_Call (N);
6111 Warn_On_Overlapping_Actuals (Nam, N);
6114 -----------------------------
6115 -- Resolve_Case_Expression --
6116 -----------------------------
6118 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6122 Alt := First (Alternatives (N));
6123 while Present (Alt) loop
6124 Resolve (Expression (Alt), Typ);
6129 Eval_Case_Expression (N);
6130 end Resolve_Case_Expression;
6132 -------------------------------
6133 -- Resolve_Character_Literal --
6134 -------------------------------
6136 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6137 B_Typ : constant Entity_Id := Base_Type (Typ);
6141 -- Verify that the character does belong to the type of the context
6143 Set_Etype (N, B_Typ);
6144 Eval_Character_Literal (N);
6146 -- Wide_Wide_Character literals must always be defined, since the set
6147 -- of wide wide character literals is complete, i.e. if a character
6148 -- literal is accepted by the parser, then it is OK for wide wide
6149 -- character (out of range character literals are rejected).
6151 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6154 -- Always accept character literal for type Any_Character, which
6155 -- occurs in error situations and in comparisons of literals, both
6156 -- of which should accept all literals.
6158 elsif B_Typ = Any_Character then
6161 -- For Standard.Character or a type derived from it, check that the
6162 -- literal is in range.
6164 elsif Root_Type (B_Typ) = Standard_Character then
6165 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6169 -- For Standard.Wide_Character or a type derived from it, check that the
6170 -- literal is in range.
6172 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6173 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6177 -- For Standard.Wide_Wide_Character or a type derived from it, we
6178 -- know the literal is in range, since the parser checked.
6180 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6183 -- If the entity is already set, this has already been resolved in a
6184 -- generic context, or comes from expansion. Nothing else to do.
6186 elsif Present (Entity (N)) then
6189 -- Otherwise we have a user defined character type, and we can use the
6190 -- standard visibility mechanisms to locate the referenced entity.
6193 C := Current_Entity (N);
6194 while Present (C) loop
6195 if Etype (C) = B_Typ then
6196 Set_Entity_With_Checks (N, C);
6197 Generate_Reference (C, N);
6205 -- If we fall through, then the literal does not match any of the
6206 -- entries of the enumeration type. This isn't just a constraint error
6207 -- situation, it is an illegality (see RM 4.2).
6210 ("character not defined for }", N, First_Subtype (B_Typ));
6211 end Resolve_Character_Literal;
6213 ---------------------------
6214 -- Resolve_Comparison_Op --
6215 ---------------------------
6217 -- Context requires a boolean type, and plays no role in resolution.
6218 -- Processing identical to that for equality operators. The result type is
6219 -- the base type, which matters when pathological subtypes of booleans with
6220 -- limited ranges are used.
6222 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6223 L : constant Node_Id := Left_Opnd (N);
6224 R : constant Node_Id := Right_Opnd (N);
6228 -- If this is an intrinsic operation which is not predefined, use the
6229 -- types of its declared arguments to resolve the possibly overloaded
6230 -- operands. Otherwise the operands are unambiguous and specify the
6233 if Scope (Entity (N)) /= Standard_Standard then
6234 T := Etype (First_Entity (Entity (N)));
6237 T := Find_Unique_Type (L, R);
6239 if T = Any_Fixed then
6240 T := Unique_Fixed_Point_Type (L);
6244 Set_Etype (N, Base_Type (Typ));
6245 Generate_Reference (T, N, ' ');
6247 -- Skip remaining processing if already set to Any_Type
6249 if T = Any_Type then
6253 -- Deal with other error cases
6255 if T = Any_String or else
6256 T = Any_Composite or else
6259 if T = Any_Character then
6260 Ambiguous_Character (L);
6262 Error_Msg_N ("ambiguous operands for comparison", N);
6265 Set_Etype (N, Any_Type);
6269 -- Resolve the operands if types OK
6273 Check_Unset_Reference (L);
6274 Check_Unset_Reference (R);
6275 Generate_Operator_Reference (N, T);
6276 Check_Low_Bound_Tested (N);
6278 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6279 -- types or array types except String.
6281 if Is_Boolean_Type (T) then
6282 Check_SPARK_Restriction
6283 ("comparison is not defined on Boolean type", N);
6285 elsif Is_Array_Type (T)
6286 and then Base_Type (T) /= Standard_String
6288 Check_SPARK_Restriction
6289 ("comparison is not defined on array types other than String", N);
6292 -- Check comparison on unordered enumeration
6294 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6295 Error_Msg_Sloc := Sloc (Etype (L));
6297 ("comparison on unordered enumeration type& declared#?U?",
6301 -- Evaluate the relation (note we do this after the above check since
6302 -- this Eval call may change N to True/False.
6304 Analyze_Dimension (N);
6305 Eval_Relational_Op (N);
6306 end Resolve_Comparison_Op;
6308 -----------------------------------------
6309 -- Resolve_Discrete_Subtype_Indication --
6310 -----------------------------------------
6312 procedure Resolve_Discrete_Subtype_Indication
6320 Analyze (Subtype_Mark (N));
6321 S := Entity (Subtype_Mark (N));
6323 if Nkind (Constraint (N)) /= N_Range_Constraint then
6324 Error_Msg_N ("expect range constraint for discrete type", N);
6325 Set_Etype (N, Any_Type);
6328 R := Range_Expression (Constraint (N));
6336 if Base_Type (S) /= Base_Type (Typ) then
6338 ("expect subtype of }", N, First_Subtype (Typ));
6340 -- Rewrite the constraint as a range of Typ
6341 -- to allow compilation to proceed further.
6344 Rewrite (Low_Bound (R),
6345 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6346 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6347 Attribute_Name => Name_First));
6348 Rewrite (High_Bound (R),
6349 Make_Attribute_Reference (Sloc (High_Bound (R)),
6350 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6351 Attribute_Name => Name_First));
6355 Set_Etype (N, Etype (R));
6357 -- Additionally, we must check that the bounds are compatible
6358 -- with the given subtype, which might be different from the
6359 -- type of the context.
6361 Apply_Range_Check (R, S);
6363 -- ??? If the above check statically detects a Constraint_Error
6364 -- it replaces the offending bound(s) of the range R with a
6365 -- Constraint_Error node. When the itype which uses these bounds
6366 -- is frozen the resulting call to Duplicate_Subexpr generates
6367 -- a new temporary for the bounds.
6369 -- Unfortunately there are other itypes that are also made depend
6370 -- on these bounds, so when Duplicate_Subexpr is called they get
6371 -- a forward reference to the newly created temporaries and Gigi
6372 -- aborts on such forward references. This is probably sign of a
6373 -- more fundamental problem somewhere else in either the order of
6374 -- itype freezing or the way certain itypes are constructed.
6376 -- To get around this problem we call Remove_Side_Effects right
6377 -- away if either bounds of R are a Constraint_Error.
6380 L : constant Node_Id := Low_Bound (R);
6381 H : constant Node_Id := High_Bound (R);
6384 if Nkind (L) = N_Raise_Constraint_Error then
6385 Remove_Side_Effects (L);
6388 if Nkind (H) = N_Raise_Constraint_Error then
6389 Remove_Side_Effects (H);
6393 Check_Unset_Reference (Low_Bound (R));
6394 Check_Unset_Reference (High_Bound (R));
6397 end Resolve_Discrete_Subtype_Indication;
6399 -------------------------
6400 -- Resolve_Entity_Name --
6401 -------------------------
6403 -- Used to resolve identifiers and expanded names
6405 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6406 function Appears_In_Check (Nod : Node_Id) return Boolean;
6407 -- Denote whether an arbitrary node Nod appears in a check node
6409 ----------------------
6410 -- Appears_In_Check --
6411 ----------------------
6413 function Appears_In_Check (Nod : Node_Id) return Boolean is
6417 -- Climb the parent chain looking for a check node
6420 while Present (Par) loop
6421 if Nkind (Par) in N_Raise_xxx_Error then
6424 -- Prevent the search from going too far
6426 elsif Is_Body_Or_Package_Declaration (Par) then
6430 Par := Parent (Par);
6434 end Appears_In_Check;
6438 E : constant Entity_Id := Entity (N);
6439 Par : constant Node_Id := Parent (N);
6441 -- Start of processing for Resolve_Entity_Name
6444 -- If garbage from errors, set to Any_Type and return
6446 if No (E) and then Total_Errors_Detected /= 0 then
6447 Set_Etype (N, Any_Type);
6451 -- Replace named numbers by corresponding literals. Note that this is
6452 -- the one case where Resolve_Entity_Name must reset the Etype, since
6453 -- it is currently marked as universal.
6455 if Ekind (E) = E_Named_Integer then
6457 Eval_Named_Integer (N);
6459 elsif Ekind (E) = E_Named_Real then
6461 Eval_Named_Real (N);
6463 -- For enumeration literals, we need to make sure that a proper style
6464 -- check is done, since such literals are overloaded, and thus we did
6465 -- not do a style check during the first phase of analysis.
6467 elsif Ekind (E) = E_Enumeration_Literal then
6468 Set_Entity_With_Checks (N, E);
6469 Eval_Entity_Name (N);
6471 -- Case of subtype name appearing as an operand in expression
6473 elsif Is_Type (E) then
6475 -- Allow use of subtype if it is a concurrent type where we are
6476 -- currently inside the body. This will eventually be expanded into a
6477 -- call to Self (for tasks) or _object (for protected objects). Any
6478 -- other use of a subtype is invalid.
6480 if Is_Concurrent_Type (E)
6481 and then In_Open_Scopes (E)
6485 -- Any other use is an error
6489 ("invalid use of subtype mark in expression or call", N);
6492 -- Check discriminant use if entity is discriminant in current scope,
6493 -- i.e. discriminant of record or concurrent type currently being
6494 -- analyzed. Uses in corresponding body are unrestricted.
6496 elsif Ekind (E) = E_Discriminant
6497 and then Scope (E) = Current_Scope
6498 and then not Has_Completion (Current_Scope)
6500 Check_Discriminant_Use (N);
6502 -- A parameterless generic function cannot appear in a context that
6503 -- requires resolution.
6505 elsif Ekind (E) = E_Generic_Function then
6506 Error_Msg_N ("illegal use of generic function", N);
6508 elsif Ekind (E) = E_Out_Parameter
6509 and then Ada_Version = Ada_83
6510 and then (Nkind (Parent (N)) in N_Op
6511 or else (Nkind (Parent (N)) = N_Assignment_Statement
6512 and then N = Expression (Parent (N)))
6513 or else Nkind (Parent (N)) = N_Explicit_Dereference)
6515 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6517 -- In all other cases, just do the possible static evaluation
6520 -- A deferred constant that appears in an expression must have a
6521 -- completion, unless it has been removed by in-place expansion of
6524 if Ekind (E) = E_Constant
6525 and then Comes_From_Source (E)
6526 and then No (Constant_Value (E))
6527 and then Is_Frozen (Etype (E))
6528 and then not In_Spec_Expression
6529 and then not Is_Imported (E)
6531 if No_Initialization (Parent (E))
6532 or else (Present (Full_View (E))
6533 and then No_Initialization (Parent (Full_View (E))))
6538 "deferred constant is frozen before completion", N);
6542 Eval_Entity_Name (N);
6545 -- A volatile object subject to enabled properties Async_Writers or
6546 -- Effective_Reads must appear in a specific context. The following
6547 -- checks are only relevant when SPARK_Mode is on as they are not
6548 -- standard Ada legality rules.
6551 and then Is_Object (E)
6552 and then Is_SPARK_Volatile (E)
6553 and then Comes_From_Source (E)
6555 (Async_Writers_Enabled (E) or else Effective_Reads_Enabled (E))
6557 -- The volatile object can appear on either side of an assignment
6559 if Nkind (Par) = N_Assignment_Statement then
6562 -- The volatile object is part of the initialization expression of
6563 -- another object. Ensure that the climb of the parent chain came
6564 -- from the expression side and not from the name side.
6566 elsif Nkind (Par) = N_Object_Declaration
6567 and then Present (Expression (Par))
6568 and then N = Expression (Par)
6572 -- The volatile object appears as an actual parameter in a call to an
6573 -- instance of Unchecked_Conversion whose result is renamed.
6575 elsif Nkind (Par) = N_Function_Call
6576 and then Is_Unchecked_Conversion_Instance (Entity (Name (Par)))
6577 and then Nkind (Parent (Par)) = N_Object_Renaming_Declaration
6581 -- Assume that references to volatile objects that appear as actual
6582 -- parameters in a procedure call are always legal. The full legality
6583 -- check is done when the actuals are resolved.
6585 elsif Nkind (Par) = N_Procedure_Call_Statement then
6588 -- Allow references to volatile objects in various checks
6590 elsif Appears_In_Check (Par) then
6595 ("volatile object cannot appear in this context "
6596 & "(SPARK RM 7.1.3(13))", N);
6599 end Resolve_Entity_Name;
6605 procedure Resolve_Entry (Entry_Name : Node_Id) is
6606 Loc : constant Source_Ptr := Sloc (Entry_Name);
6614 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6615 -- If the bounds of the entry family being called depend on task
6616 -- discriminants, build a new index subtype where a discriminant is
6617 -- replaced with the value of the discriminant of the target task.
6618 -- The target task is the prefix of the entry name in the call.
6620 -----------------------
6621 -- Actual_Index_Type --
6622 -----------------------
6624 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
6625 Typ : constant Entity_Id := Entry_Index_Type (E);
6626 Tsk : constant Entity_Id := Scope (E);
6627 Lo : constant Node_Id := Type_Low_Bound (Typ);
6628 Hi : constant Node_Id := Type_High_Bound (Typ);
6631 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6632 -- If the bound is given by a discriminant, replace with a reference
6633 -- to the discriminant of the same name in the target task. If the
6634 -- entry name is the target of a requeue statement and the entry is
6635 -- in the current protected object, the bound to be used is the
6636 -- discriminal of the object (see Apply_Range_Checks for details of
6637 -- the transformation).
6639 -----------------------------
6640 -- Actual_Discriminant_Ref --
6641 -----------------------------
6643 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
6644 Typ : constant Entity_Id := Etype (Bound);
6648 Remove_Side_Effects (Bound);
6650 if not Is_Entity_Name (Bound)
6651 or else Ekind (Entity (Bound)) /= E_Discriminant
6655 elsif Is_Protected_Type (Tsk)
6656 and then In_Open_Scopes (Tsk)
6657 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6659 -- Note: here Bound denotes a discriminant of the corresponding
6660 -- record type tskV, whose discriminal is a formal of the
6661 -- init-proc tskVIP. What we want is the body discriminal,
6662 -- which is associated to the discriminant of the original
6663 -- concurrent type tsk.
6665 return New_Occurrence_Of
6666 (Find_Body_Discriminal (Entity (Bound)), Loc);
6670 Make_Selected_Component (Loc,
6671 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6672 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6677 end Actual_Discriminant_Ref;
6679 -- Start of processing for Actual_Index_Type
6682 if not Has_Discriminants (Tsk)
6683 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
6685 return Entry_Index_Type (E);
6688 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6689 Set_Etype (New_T, Base_Type (Typ));
6690 Set_Size_Info (New_T, Typ);
6691 Set_RM_Size (New_T, RM_Size (Typ));
6692 Set_Scalar_Range (New_T,
6693 Make_Range (Sloc (Entry_Name),
6694 Low_Bound => Actual_Discriminant_Ref (Lo),
6695 High_Bound => Actual_Discriminant_Ref (Hi)));
6699 end Actual_Index_Type;
6701 -- Start of processing of Resolve_Entry
6704 -- Find name of entry being called, and resolve prefix of name with its
6705 -- own type. The prefix can be overloaded, and the name and signature of
6706 -- the entry must be taken into account.
6708 if Nkind (Entry_Name) = N_Indexed_Component then
6710 -- Case of dealing with entry family within the current tasks
6712 E_Name := Prefix (Entry_Name);
6715 E_Name := Entry_Name;
6718 if Is_Entity_Name (E_Name) then
6720 -- Entry call to an entry (or entry family) in the current task. This
6721 -- is legal even though the task will deadlock. Rewrite as call to
6724 -- This can also be a call to an entry in an enclosing task. If this
6725 -- is a single task, we have to retrieve its name, because the scope
6726 -- of the entry is the task type, not the object. If the enclosing
6727 -- task is a task type, the identity of the task is given by its own
6730 -- Finally this can be a requeue on an entry of the same task or
6731 -- protected object.
6733 S := Scope (Entity (E_Name));
6735 for J in reverse 0 .. Scope_Stack.Last loop
6736 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6737 and then not Comes_From_Source (S)
6739 -- S is an enclosing task or protected object. The concurrent
6740 -- declaration has been converted into a type declaration, and
6741 -- the object itself has an object declaration that follows
6742 -- the type in the same declarative part.
6744 Tsk := Next_Entity (S);
6745 while Etype (Tsk) /= S loop
6752 elsif S = Scope_Stack.Table (J).Entity then
6754 -- Call to current task. Will be transformed into call to Self
6762 Make_Selected_Component (Loc,
6763 Prefix => New_Occurrence_Of (S, Loc),
6765 New_Occurrence_Of (Entity (E_Name), Loc));
6766 Rewrite (E_Name, New_N);
6769 elsif Nkind (Entry_Name) = N_Selected_Component
6770 and then Is_Overloaded (Prefix (Entry_Name))
6772 -- Use the entry name (which must be unique at this point) to find
6773 -- the prefix that returns the corresponding task/protected type.
6776 Pref : constant Node_Id := Prefix (Entry_Name);
6777 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
6782 Get_First_Interp (Pref, I, It);
6783 while Present (It.Typ) loop
6784 if Scope (Ent) = It.Typ then
6785 Set_Etype (Pref, It.Typ);
6789 Get_Next_Interp (I, It);
6794 if Nkind (Entry_Name) = N_Selected_Component then
6795 Resolve (Prefix (Entry_Name));
6797 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6798 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6799 Resolve (Prefix (Prefix (Entry_Name)));
6800 Index := First (Expressions (Entry_Name));
6801 Resolve (Index, Entry_Index_Type (Nam));
6803 -- Up to this point the expression could have been the actual in a
6804 -- simple entry call, and be given by a named association.
6806 if Nkind (Index) = N_Parameter_Association then
6807 Error_Msg_N ("expect expression for entry index", Index);
6809 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6814 ------------------------
6815 -- Resolve_Entry_Call --
6816 ------------------------
6818 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6819 Entry_Name : constant Node_Id := Name (N);
6820 Loc : constant Source_Ptr := Sloc (Entry_Name);
6822 First_Named : Node_Id;
6829 -- We kill all checks here, because it does not seem worth the effort to
6830 -- do anything better, an entry call is a big operation.
6834 -- Processing of the name is similar for entry calls and protected
6835 -- operation calls. Once the entity is determined, we can complete
6836 -- the resolution of the actuals.
6838 -- The selector may be overloaded, in the case of a protected object
6839 -- with overloaded functions. The type of the context is used for
6842 if Nkind (Entry_Name) = N_Selected_Component
6843 and then Is_Overloaded (Selector_Name (Entry_Name))
6844 and then Typ /= Standard_Void_Type
6851 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6852 while Present (It.Typ) loop
6853 if Covers (Typ, It.Typ) then
6854 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6855 Set_Etype (Entry_Name, It.Typ);
6857 Generate_Reference (It.Typ, N, ' ');
6860 Get_Next_Interp (I, It);
6865 Resolve_Entry (Entry_Name);
6867 if Nkind (Entry_Name) = N_Selected_Component then
6869 -- Simple entry call
6871 Nam := Entity (Selector_Name (Entry_Name));
6872 Obj := Prefix (Entry_Name);
6873 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6875 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6877 -- Call to member of entry family
6879 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6880 Obj := Prefix (Prefix (Entry_Name));
6881 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6884 -- We cannot in general check the maximum depth of protected entry calls
6885 -- at compile time. But we can tell that any protected entry call at all
6886 -- violates a specified nesting depth of zero.
6888 if Is_Protected_Type (Scope (Nam)) then
6889 Check_Restriction (Max_Entry_Queue_Length, N);
6892 -- Use context type to disambiguate a protected function that can be
6893 -- called without actuals and that returns an array type, and where the
6894 -- argument list may be an indexing of the returned value.
6896 if Ekind (Nam) = E_Function
6897 and then Needs_No_Actuals (Nam)
6898 and then Present (Parameter_Associations (N))
6900 ((Is_Array_Type (Etype (Nam))
6901 and then Covers (Typ, Component_Type (Etype (Nam))))
6903 or else (Is_Access_Type (Etype (Nam))
6904 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6908 Component_Type (Designated_Type (Etype (Nam))))))
6911 Index_Node : Node_Id;
6915 Make_Indexed_Component (Loc,
6917 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
6918 Expressions => Parameter_Associations (N));
6920 -- Since we are correcting a node classification error made by the
6921 -- parser, we call Replace rather than Rewrite.
6923 Replace (N, Index_Node);
6924 Set_Etype (Prefix (N), Etype (Nam));
6926 Resolve_Indexed_Component (N, Typ);
6931 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6932 and then Present (PPC_Wrapper (Nam))
6933 and then Current_Scope /= PPC_Wrapper (Nam)
6935 -- Rewrite as call to the precondition wrapper, adding the task
6936 -- object to the list of actuals. If the call is to a member of an
6937 -- entry family, include the index as well.
6941 New_Actuals : List_Id;
6944 New_Actuals := New_List (Obj);
6946 if Nkind (Entry_Name) = N_Indexed_Component then
6947 Append_To (New_Actuals,
6948 New_Copy_Tree (First (Expressions (Entry_Name))));
6951 Append_List (Parameter_Associations (N), New_Actuals);
6953 Make_Procedure_Call_Statement (Loc,
6955 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6956 Parameter_Associations => New_Actuals);
6957 Rewrite (N, New_Call);
6958 Analyze_And_Resolve (N);
6963 -- The operation name may have been overloaded. Order the actuals
6964 -- according to the formals of the resolved entity, and set the return
6965 -- type to that of the operation.
6968 Normalize_Actuals (N, Nam, False, Norm_OK);
6969 pragma Assert (Norm_OK);
6970 Set_Etype (N, Etype (Nam));
6973 Resolve_Actuals (N, Nam);
6974 Check_Internal_Protected_Use (N, Nam);
6976 -- Create a call reference to the entry
6978 Generate_Reference (Nam, Entry_Name, 's');
6980 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
6981 Check_Potentially_Blocking_Operation (N);
6984 -- Verify that a procedure call cannot masquerade as an entry
6985 -- call where an entry call is expected.
6987 if Ekind (Nam) = E_Procedure then
6988 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6989 and then N = Entry_Call_Statement (Parent (N))
6991 Error_Msg_N ("entry call required in select statement", N);
6993 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6994 and then N = Triggering_Statement (Parent (N))
6996 Error_Msg_N ("triggering statement cannot be procedure call", N);
6998 elsif Ekind (Scope (Nam)) = E_Task_Type
6999 and then not In_Open_Scopes (Scope (Nam))
7001 Error_Msg_N ("task has no entry with this name", Entry_Name);
7005 -- After resolution, entry calls and protected procedure calls are
7006 -- changed into entry calls, for expansion. The structure of the node
7007 -- does not change, so it can safely be done in place. Protected
7008 -- function calls must keep their structure because they are
7011 if Ekind (Nam) /= E_Function then
7013 -- A protected operation that is not a function may modify the
7014 -- corresponding object, and cannot apply to a constant. If this
7015 -- is an internal call, the prefix is the type itself.
7017 if Is_Protected_Type (Scope (Nam))
7018 and then not Is_Variable (Obj)
7019 and then (not Is_Entity_Name (Obj)
7020 or else not Is_Type (Entity (Obj)))
7023 ("prefix of protected procedure or entry call must be variable",
7027 Actuals := Parameter_Associations (N);
7028 First_Named := First_Named_Actual (N);
7031 Make_Entry_Call_Statement (Loc,
7033 Parameter_Associations => Actuals));
7035 Set_First_Named_Actual (N, First_Named);
7036 Set_Analyzed (N, True);
7038 -- Protected functions can return on the secondary stack, in which
7039 -- case we must trigger the transient scope mechanism.
7041 elsif Expander_Active
7042 and then Requires_Transient_Scope (Etype (Nam))
7044 Establish_Transient_Scope (N, Sec_Stack => True);
7046 end Resolve_Entry_Call;
7048 -------------------------
7049 -- Resolve_Equality_Op --
7050 -------------------------
7052 -- Both arguments must have the same type, and the boolean context does
7053 -- not participate in the resolution. The first pass verifies that the
7054 -- interpretation is not ambiguous, and the type of the left argument is
7055 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7056 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7057 -- though they carry a single (universal) type. Diagnose this case here.
7059 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7060 L : constant Node_Id := Left_Opnd (N);
7061 R : constant Node_Id := Right_Opnd (N);
7062 T : Entity_Id := Find_Unique_Type (L, R);
7064 procedure Check_If_Expression (Cond : Node_Id);
7065 -- The resolution rule for if expressions requires that each such must
7066 -- have a unique type. This means that if several dependent expressions
7067 -- are of a non-null anonymous access type, and the context does not
7068 -- impose an expected type (as can be the case in an equality operation)
7069 -- the expression must be rejected.
7071 procedure Explain_Redundancy (N : Node_Id);
7072 -- Attempt to explain the nature of a redundant comparison with True. If
7073 -- the expression N is too complex, this routine issues a general error
7076 function Find_Unique_Access_Type return Entity_Id;
7077 -- In the case of allocators and access attributes, the context must
7078 -- provide an indication of the specific access type to be used. If
7079 -- one operand is of such a "generic" access type, check whether there
7080 -- is a specific visible access type that has the same designated type.
7081 -- This is semantically dubious, and of no interest to any real code,
7082 -- but c48008a makes it all worthwhile.
7084 -------------------------
7085 -- Check_If_Expression --
7086 -------------------------
7088 procedure Check_If_Expression (Cond : Node_Id) is
7089 Then_Expr : Node_Id;
7090 Else_Expr : Node_Id;
7093 if Nkind (Cond) = N_If_Expression then
7094 Then_Expr := Next (First (Expressions (Cond)));
7095 Else_Expr := Next (Then_Expr);
7097 if Nkind (Then_Expr) /= N_Null
7098 and then Nkind (Else_Expr) /= N_Null
7100 Error_Msg_N ("cannot determine type of if expression", Cond);
7103 end Check_If_Expression;
7105 ------------------------
7106 -- Explain_Redundancy --
7107 ------------------------
7109 procedure Explain_Redundancy (N : Node_Id) is
7117 -- Strip the operand down to an entity
7120 if Nkind (Val) = N_Selected_Component then
7121 Val := Selector_Name (Val);
7127 -- The construct denotes an entity
7129 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7130 Val_Id := Entity (Val);
7132 -- Do not generate an error message when the comparison is done
7133 -- against the enumeration literal Standard.True.
7135 if Ekind (Val_Id) /= E_Enumeration_Literal then
7137 -- Build a customized error message
7140 Add_Str_To_Name_Buffer ("?r?");
7142 if Ekind (Val_Id) = E_Component then
7143 Add_Str_To_Name_Buffer ("component ");
7145 elsif Ekind (Val_Id) = E_Constant then
7146 Add_Str_To_Name_Buffer ("constant ");
7148 elsif Ekind (Val_Id) = E_Discriminant then
7149 Add_Str_To_Name_Buffer ("discriminant ");
7151 elsif Is_Formal (Val_Id) then
7152 Add_Str_To_Name_Buffer ("parameter ");
7154 elsif Ekind (Val_Id) = E_Variable then
7155 Add_Str_To_Name_Buffer ("variable ");
7158 Add_Str_To_Name_Buffer ("& is always True!");
7161 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7164 -- The construct is too complex to disect, issue a general message
7167 Error_Msg_N ("?r?expression is always True!", Val);
7169 end Explain_Redundancy;
7171 -----------------------------
7172 -- Find_Unique_Access_Type --
7173 -----------------------------
7175 function Find_Unique_Access_Type return Entity_Id is
7181 if Ekind_In (Etype (R), E_Allocator_Type,
7182 E_Access_Attribute_Type)
7184 Acc := Designated_Type (Etype (R));
7186 elsif Ekind_In (Etype (L), E_Allocator_Type,
7187 E_Access_Attribute_Type)
7189 Acc := Designated_Type (Etype (L));
7195 while S /= Standard_Standard loop
7196 E := First_Entity (S);
7197 while Present (E) loop
7199 and then Is_Access_Type (E)
7200 and then Ekind (E) /= E_Allocator_Type
7201 and then Designated_Type (E) = Base_Type (Acc)
7213 end Find_Unique_Access_Type;
7215 -- Start of processing for Resolve_Equality_Op
7218 Set_Etype (N, Base_Type (Typ));
7219 Generate_Reference (T, N, ' ');
7221 if T = Any_Fixed then
7222 T := Unique_Fixed_Point_Type (L);
7225 if T /= Any_Type then
7226 if T = Any_String or else
7227 T = Any_Composite or else
7230 if T = Any_Character then
7231 Ambiguous_Character (L);
7233 Error_Msg_N ("ambiguous operands for equality", N);
7236 Set_Etype (N, Any_Type);
7239 elsif T = Any_Access
7240 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7242 T := Find_Unique_Access_Type;
7245 Error_Msg_N ("ambiguous operands for equality", N);
7246 Set_Etype (N, Any_Type);
7250 -- If expressions must have a single type, and if the context does
7251 -- not impose one the dependent expressions cannot be anonymous
7254 -- Why no similar processing for case expressions???
7256 elsif Ada_Version >= Ada_2012
7257 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7258 E_Anonymous_Access_Subprogram_Type)
7259 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7260 E_Anonymous_Access_Subprogram_Type)
7262 Check_If_Expression (L);
7263 Check_If_Expression (R);
7269 -- In SPARK, equality operators = and /= for array types other than
7270 -- String are only defined when, for each index position, the
7271 -- operands have equal static bounds.
7273 if Is_Array_Type (T) then
7275 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7276 -- operation if not needed.
7278 if Restriction_Check_Required (SPARK_05)
7279 and then Base_Type (T) /= Standard_String
7280 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7281 and then Etype (L) /= Any_Composite -- or else L in error
7282 and then Etype (R) /= Any_Composite -- or else R in error
7283 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7285 Check_SPARK_Restriction
7286 ("array types should have matching static bounds", N);
7290 -- If the unique type is a class-wide type then it will be expanded
7291 -- into a dispatching call to the predefined primitive. Therefore we
7292 -- check here for potential violation of such restriction.
7294 if Is_Class_Wide_Type (T) then
7295 Check_Restriction (No_Dispatching_Calls, N);
7298 if Warn_On_Redundant_Constructs
7299 and then Comes_From_Source (N)
7300 and then Comes_From_Source (R)
7301 and then Is_Entity_Name (R)
7302 and then Entity (R) = Standard_True
7304 Error_Msg_N -- CODEFIX
7305 ("?r?comparison with True is redundant!", N);
7306 Explain_Redundancy (Original_Node (R));
7309 Check_Unset_Reference (L);
7310 Check_Unset_Reference (R);
7311 Generate_Operator_Reference (N, T);
7312 Check_Low_Bound_Tested (N);
7314 -- If this is an inequality, it may be the implicit inequality
7315 -- created for a user-defined operation, in which case the corres-
7316 -- ponding equality operation is not intrinsic, and the operation
7317 -- cannot be constant-folded. Else fold.
7319 if Nkind (N) = N_Op_Eq
7320 or else Comes_From_Source (Entity (N))
7321 or else Ekind (Entity (N)) = E_Operator
7322 or else Is_Intrinsic_Subprogram
7323 (Corresponding_Equality (Entity (N)))
7325 Analyze_Dimension (N);
7326 Eval_Relational_Op (N);
7328 elsif Nkind (N) = N_Op_Ne
7329 and then Is_Abstract_Subprogram (Entity (N))
7331 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7334 -- Ada 2005: If one operand is an anonymous access type, convert the
7335 -- other operand to it, to ensure that the underlying types match in
7336 -- the back-end. Same for access_to_subprogram, and the conversion
7337 -- verifies that the types are subtype conformant.
7339 -- We apply the same conversion in the case one of the operands is a
7340 -- private subtype of the type of the other.
7342 -- Why the Expander_Active test here ???
7346 (Ekind_In (T, E_Anonymous_Access_Type,
7347 E_Anonymous_Access_Subprogram_Type)
7348 or else Is_Private_Type (T))
7350 if Etype (L) /= T then
7352 Make_Unchecked_Type_Conversion (Sloc (L),
7353 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7354 Expression => Relocate_Node (L)));
7355 Analyze_And_Resolve (L, T);
7358 if (Etype (R)) /= T then
7360 Make_Unchecked_Type_Conversion (Sloc (R),
7361 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7362 Expression => Relocate_Node (R)));
7363 Analyze_And_Resolve (R, T);
7367 end Resolve_Equality_Op;
7369 ----------------------------------
7370 -- Resolve_Explicit_Dereference --
7371 ----------------------------------
7373 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7374 Loc : constant Source_Ptr := Sloc (N);
7376 P : constant Node_Id := Prefix (N);
7379 -- The candidate prefix type, if overloaded
7385 Check_Fully_Declared_Prefix (Typ, P);
7388 -- A useful optimization: check whether the dereference denotes an
7389 -- element of a container, and if so rewrite it as a call to the
7390 -- corresponding Element function.
7392 -- Disabled for now, on advice of ARG. A more restricted form of the
7393 -- predicate might be acceptable ???
7395 -- if Is_Container_Element (N) then
7399 if Is_Overloaded (P) then
7401 -- Use the context type to select the prefix that has the correct
7402 -- designated type. Keep the first match, which will be the inner-
7405 Get_First_Interp (P, I, It);
7407 while Present (It.Typ) loop
7408 if Is_Access_Type (It.Typ)
7409 and then Covers (Typ, Designated_Type (It.Typ))
7415 -- Remove access types that do not match, but preserve access
7416 -- to subprogram interpretations, in case a further dereference
7417 -- is needed (see below).
7419 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
7423 Get_Next_Interp (I, It);
7426 if Present (P_Typ) then
7428 Set_Etype (N, Designated_Type (P_Typ));
7431 -- If no interpretation covers the designated type of the prefix,
7432 -- this is the pathological case where not all implementations of
7433 -- the prefix allow the interpretation of the node as a call. Now
7434 -- that the expected type is known, Remove other interpretations
7435 -- from prefix, rewrite it as a call, and resolve again, so that
7436 -- the proper call node is generated.
7438 Get_First_Interp (P, I, It);
7439 while Present (It.Typ) loop
7440 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
7444 Get_Next_Interp (I, It);
7448 Make_Function_Call (Loc,
7450 Make_Explicit_Dereference (Loc,
7452 Parameter_Associations => New_List);
7454 Save_Interps (N, New_N);
7456 Analyze_And_Resolve (N, Typ);
7460 -- If not overloaded, resolve P with its own type
7466 if Is_Access_Type (Etype (P)) then
7467 Apply_Access_Check (N);
7470 -- If the designated type is a packed unconstrained array type, and the
7471 -- explicit dereference is not in the context of an attribute reference,
7472 -- then we must compute and set the actual subtype, since it is needed
7473 -- by Gigi. The reason we exclude the attribute case is that this is
7474 -- handled fine by Gigi, and in fact we use such attributes to build the
7475 -- actual subtype. We also exclude generated code (which builds actual
7476 -- subtypes directly if they are needed).
7478 if Is_Array_Type (Etype (N))
7479 and then Is_Packed (Etype (N))
7480 and then not Is_Constrained (Etype (N))
7481 and then Nkind (Parent (N)) /= N_Attribute_Reference
7482 and then Comes_From_Source (N)
7484 Set_Etype (N, Get_Actual_Subtype (N));
7487 -- Note: No Eval processing is required for an explicit dereference,
7488 -- because such a name can never be static.
7490 end Resolve_Explicit_Dereference;
7492 -------------------------------------
7493 -- Resolve_Expression_With_Actions --
7494 -------------------------------------
7496 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
7500 -- If N has no actions, and its expression has been constant folded,
7501 -- then rewrite N as just its expression. Note, we can't do this in
7502 -- the general case of Is_Empty_List (Actions (N)) as this would cause
7503 -- Expression (N) to be expanded again.
7505 if Is_Empty_List (Actions (N))
7506 and then Compile_Time_Known_Value (Expression (N))
7508 Rewrite (N, Expression (N));
7510 end Resolve_Expression_With_Actions;
7512 ----------------------------------
7513 -- Resolve_Generalized_Indexing --
7514 ----------------------------------
7516 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
7517 Indexing : constant Node_Id := Generalized_Indexing (N);
7523 -- In ASIS mode, propagate the information about the indices back to
7524 -- to the original indexing node. The generalized indexing is either
7525 -- a function call, or a dereference of one. The actuals include the
7526 -- prefix of the original node, which is the container expression.
7529 Resolve (Indexing, Typ);
7530 Set_Etype (N, Etype (Indexing));
7531 Set_Is_Overloaded (N, False);
7534 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
7536 Call := Prefix (Call);
7539 if Nkind (Call) = N_Function_Call then
7540 Indices := Parameter_Associations (Call);
7541 Pref := Remove_Head (Indices);
7542 Set_Expressions (N, Indices);
7543 Set_Prefix (N, Pref);
7547 Rewrite (N, Indexing);
7550 end Resolve_Generalized_Indexing;
7552 ---------------------------
7553 -- Resolve_If_Expression --
7554 ---------------------------
7556 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
7557 Condition : constant Node_Id := First (Expressions (N));
7558 Then_Expr : constant Node_Id := Next (Condition);
7559 Else_Expr : Node_Id := Next (Then_Expr);
7560 Else_Typ : Entity_Id;
7561 Then_Typ : Entity_Id;
7564 Resolve (Condition, Any_Boolean);
7565 Resolve (Then_Expr, Typ);
7566 Then_Typ := Etype (Then_Expr);
7568 -- When the "then" expression is of a scalar subtype different from the
7569 -- result subtype, then insert a conversion to ensure the generation of
7570 -- a constraint check. The same is done for the else part below, again
7571 -- comparing subtypes rather than base types.
7573 if Is_Scalar_Type (Then_Typ)
7574 and then Then_Typ /= Typ
7576 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
7577 Analyze_And_Resolve (Then_Expr, Typ);
7580 -- If ELSE expression present, just resolve using the determined type
7582 if Present (Else_Expr) then
7583 Resolve (Else_Expr, Typ);
7584 Else_Typ := Etype (Else_Expr);
7586 if Is_Scalar_Type (Else_Typ)
7587 and then Else_Typ /= Typ
7589 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
7590 Analyze_And_Resolve (Else_Expr, Typ);
7593 -- If no ELSE expression is present, root type must be Standard.Boolean
7594 -- and we provide a Standard.True result converted to the appropriate
7595 -- Boolean type (in case it is a derived boolean type).
7597 elsif Root_Type (Typ) = Standard_Boolean then
7599 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
7600 Analyze_And_Resolve (Else_Expr, Typ);
7601 Append_To (Expressions (N), Else_Expr);
7604 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
7605 Append_To (Expressions (N), Error);
7609 Eval_If_Expression (N);
7610 end Resolve_If_Expression;
7612 -------------------------------
7613 -- Resolve_Indexed_Component --
7614 -------------------------------
7616 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
7617 Name : constant Node_Id := Prefix (N);
7619 Array_Type : Entity_Id := Empty; -- to prevent junk warning
7623 if Present (Generalized_Indexing (N)) then
7624 Resolve_Generalized_Indexing (N, Typ);
7628 if Is_Overloaded (Name) then
7630 -- Use the context type to select the prefix that yields the correct
7636 I1 : Interp_Index := 0;
7637 P : constant Node_Id := Prefix (N);
7638 Found : Boolean := False;
7641 Get_First_Interp (P, I, It);
7642 while Present (It.Typ) loop
7643 if (Is_Array_Type (It.Typ)
7644 and then Covers (Typ, Component_Type (It.Typ)))
7645 or else (Is_Access_Type (It.Typ)
7646 and then Is_Array_Type (Designated_Type (It.Typ))
7650 Component_Type (Designated_Type (It.Typ))))
7653 It := Disambiguate (P, I1, I, Any_Type);
7655 if It = No_Interp then
7656 Error_Msg_N ("ambiguous prefix for indexing", N);
7662 Array_Type := It.Typ;
7668 Array_Type := It.Typ;
7673 Get_Next_Interp (I, It);
7678 Array_Type := Etype (Name);
7681 Resolve (Name, Array_Type);
7682 Array_Type := Get_Actual_Subtype_If_Available (Name);
7684 -- If prefix is access type, dereference to get real array type.
7685 -- Note: we do not apply an access check because the expander always
7686 -- introduces an explicit dereference, and the check will happen there.
7688 if Is_Access_Type (Array_Type) then
7689 Array_Type := Designated_Type (Array_Type);
7692 -- If name was overloaded, set component type correctly now
7693 -- If a misplaced call to an entry family (which has no index types)
7694 -- return. Error will be diagnosed from calling context.
7696 if Is_Array_Type (Array_Type) then
7697 Set_Etype (N, Component_Type (Array_Type));
7702 Index := First_Index (Array_Type);
7703 Expr := First (Expressions (N));
7705 -- The prefix may have resolved to a string literal, in which case its
7706 -- etype has a special representation. This is only possible currently
7707 -- if the prefix is a static concatenation, written in functional
7710 if Ekind (Array_Type) = E_String_Literal_Subtype then
7711 Resolve (Expr, Standard_Positive);
7714 while Present (Index) and Present (Expr) loop
7715 Resolve (Expr, Etype (Index));
7716 Check_Unset_Reference (Expr);
7718 if Is_Scalar_Type (Etype (Expr)) then
7719 Apply_Scalar_Range_Check (Expr, Etype (Index));
7721 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
7729 Analyze_Dimension (N);
7731 -- Do not generate the warning on suspicious index if we are analyzing
7732 -- package Ada.Tags; otherwise we will report the warning with the
7733 -- Prims_Ptr field of the dispatch table.
7735 if Scope (Etype (Prefix (N))) = Standard_Standard
7737 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
7740 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
7741 Eval_Indexed_Component (N);
7744 -- If the array type is atomic, and is packed, and we are in a left side
7745 -- context, then this is worth a warning, since we have a situation
7746 -- where the access to the component may cause extra read/writes of
7747 -- the atomic array object, which could be considered unexpected.
7749 if Nkind (N) = N_Indexed_Component
7750 and then (Is_Atomic (Array_Type)
7751 or else (Is_Entity_Name (Prefix (N))
7752 and then Is_Atomic (Entity (Prefix (N)))))
7753 and then Is_Bit_Packed_Array (Array_Type)
7754 and then Is_LHS (N) = Yes
7756 Error_Msg_N ("??assignment to component of packed atomic array",
7758 Error_Msg_N ("??\may cause unexpected accesses to atomic object",
7761 end Resolve_Indexed_Component;
7763 -----------------------------
7764 -- Resolve_Integer_Literal --
7765 -----------------------------
7767 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7770 Eval_Integer_Literal (N);
7771 end Resolve_Integer_Literal;
7773 --------------------------------
7774 -- Resolve_Intrinsic_Operator --
7775 --------------------------------
7777 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
7778 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7780 Orig_Op : constant Entity_Id := Entity (N);
7784 function Convert_Operand (Opnd : Node_Id) return Node_Id;
7785 -- If the operand is a literal, it cannot be the expression in a
7786 -- conversion. Use a qualified expression instead.
7788 function Convert_Operand (Opnd : Node_Id) return Node_Id is
7789 Loc : constant Source_Ptr := Sloc (Opnd);
7792 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
7794 Make_Qualified_Expression (Loc,
7795 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7796 Expression => Relocate_Node (Opnd));
7800 Res := Unchecked_Convert_To (Btyp, Opnd);
7804 end Convert_Operand;
7806 -- Start of processing for Resolve_Intrinsic_Operator
7809 -- We must preserve the original entity in a generic setting, so that
7810 -- the legality of the operation can be verified in an instance.
7812 if not Expander_Active then
7817 while Scope (Op) /= Standard_Standard loop
7819 pragma Assert (Present (Op));
7823 Set_Is_Overloaded (N, False);
7825 -- If the result or operand types are private, rewrite with unchecked
7826 -- conversions on the operands and the result, to expose the proper
7827 -- underlying numeric type.
7829 if Is_Private_Type (Typ)
7830 or else Is_Private_Type (Etype (Left_Opnd (N)))
7831 or else Is_Private_Type (Etype (Right_Opnd (N)))
7833 Arg1 := Convert_Operand (Left_Opnd (N));
7834 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
7835 -- What on earth is this commented out fragment of code???
7837 if Nkind (N) = N_Op_Expon then
7838 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7840 Arg2 := Convert_Operand (Right_Opnd (N));
7843 if Nkind (Arg1) = N_Type_Conversion then
7844 Save_Interps (Left_Opnd (N), Expression (Arg1));
7847 if Nkind (Arg2) = N_Type_Conversion then
7848 Save_Interps (Right_Opnd (N), Expression (Arg2));
7851 Set_Left_Opnd (N, Arg1);
7852 Set_Right_Opnd (N, Arg2);
7854 Set_Etype (N, Btyp);
7855 Rewrite (N, Unchecked_Convert_To (Typ, N));
7858 elsif Typ /= Etype (Left_Opnd (N))
7859 or else Typ /= Etype (Right_Opnd (N))
7861 -- Add explicit conversion where needed, and save interpretations in
7862 -- case operands are overloaded. If the context is a VMS operation,
7863 -- assert that the conversion is legal (the operands have the proper
7864 -- types to select the VMS intrinsic). Note that in rare cases the
7865 -- VMS operators may be visible, but the default System is being used
7866 -- and Address is a private type.
7868 Arg1 := Convert_To (Typ, Left_Opnd (N));
7869 Arg2 := Convert_To (Typ, Right_Opnd (N));
7871 if Nkind (Arg1) = N_Type_Conversion then
7872 Save_Interps (Left_Opnd (N), Expression (Arg1));
7874 if Is_VMS_Operator (Orig_Op) then
7875 Set_Conversion_OK (Arg1);
7878 Save_Interps (Left_Opnd (N), Arg1);
7881 if Nkind (Arg2) = N_Type_Conversion then
7882 Save_Interps (Right_Opnd (N), Expression (Arg2));
7884 if Is_VMS_Operator (Orig_Op) then
7885 Set_Conversion_OK (Arg2);
7888 Save_Interps (Right_Opnd (N), Arg2);
7891 Rewrite (Left_Opnd (N), Arg1);
7892 Rewrite (Right_Opnd (N), Arg2);
7895 Resolve_Arithmetic_Op (N, Typ);
7898 Resolve_Arithmetic_Op (N, Typ);
7900 end Resolve_Intrinsic_Operator;
7902 --------------------------------------
7903 -- Resolve_Intrinsic_Unary_Operator --
7904 --------------------------------------
7906 procedure Resolve_Intrinsic_Unary_Operator
7910 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7916 while Scope (Op) /= Standard_Standard loop
7918 pragma Assert (Present (Op));
7923 if Is_Private_Type (Typ) then
7924 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7925 Save_Interps (Right_Opnd (N), Expression (Arg2));
7927 Set_Right_Opnd (N, Arg2);
7929 Set_Etype (N, Btyp);
7930 Rewrite (N, Unchecked_Convert_To (Typ, N));
7934 Resolve_Unary_Op (N, Typ);
7936 end Resolve_Intrinsic_Unary_Operator;
7938 ------------------------
7939 -- Resolve_Logical_Op --
7940 ------------------------
7942 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7946 Check_No_Direct_Boolean_Operators (N);
7948 -- Predefined operations on scalar types yield the base type. On the
7949 -- other hand, logical operations on arrays yield the type of the
7950 -- arguments (and the context).
7952 if Is_Array_Type (Typ) then
7955 B_Typ := Base_Type (Typ);
7958 -- OK if this is a VMS-specific intrinsic operation
7960 if Is_VMS_Operator (Entity (N)) then
7963 -- The following test is required because the operands of the operation
7964 -- may be literals, in which case the resulting type appears to be
7965 -- compatible with a signed integer type, when in fact it is compatible
7966 -- only with modular types. If the context itself is universal, the
7967 -- operation is illegal.
7969 elsif not Valid_Boolean_Arg (Typ) then
7970 Error_Msg_N ("invalid context for logical operation", N);
7971 Set_Etype (N, Any_Type);
7974 elsif Typ = Any_Modular then
7976 ("no modular type available in this context", N);
7977 Set_Etype (N, Any_Type);
7980 elsif Is_Modular_Integer_Type (Typ)
7981 and then Etype (Left_Opnd (N)) = Universal_Integer
7982 and then Etype (Right_Opnd (N)) = Universal_Integer
7984 Check_For_Visible_Operator (N, B_Typ);
7987 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
7988 -- is active and the result type is standard Boolean (do not mess with
7989 -- ops that return a nonstandard Boolean type, because something strange
7992 -- Note: you might expect this replacement to be done during expansion,
7993 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
7994 -- is used, no part of the right operand of an "and" or "or" operator
7995 -- should be executed if the left operand would short-circuit the
7996 -- evaluation of the corresponding "and then" or "or else". If we left
7997 -- the replacement to expansion time, then run-time checks associated
7998 -- with such operands would be evaluated unconditionally, due to being
7999 -- before the condition prior to the rewriting as short-circuit forms
8000 -- during expansion.
8002 if Short_Circuit_And_Or
8003 and then B_Typ = Standard_Boolean
8004 and then Nkind_In (N, N_Op_And, N_Op_Or)
8006 if Nkind (N) = N_Op_And then
8008 Make_And_Then (Sloc (N),
8009 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8010 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8011 Analyze_And_Resolve (N, B_Typ);
8013 -- Case of OR changed to OR ELSE
8017 Make_Or_Else (Sloc (N),
8018 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8019 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8020 Analyze_And_Resolve (N, B_Typ);
8023 -- Return now, since analysis of the rewritten ops will take care of
8024 -- other reference bookkeeping and expression folding.
8029 Resolve (Left_Opnd (N), B_Typ);
8030 Resolve (Right_Opnd (N), B_Typ);
8032 Check_Unset_Reference (Left_Opnd (N));
8033 Check_Unset_Reference (Right_Opnd (N));
8035 Set_Etype (N, B_Typ);
8036 Generate_Operator_Reference (N, B_Typ);
8037 Eval_Logical_Op (N);
8039 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8040 -- only when both operands have same static lower and higher bounds. Of
8041 -- course the types have to match, so only check if operands are
8042 -- compatible and the node itself has no errors.
8044 if Is_Array_Type (B_Typ)
8045 and then Nkind (N) in N_Binary_Op
8048 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8049 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8052 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8053 -- operation if not needed.
8055 if Restriction_Check_Required (SPARK_05)
8056 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8057 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8058 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8059 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8061 Check_SPARK_Restriction
8062 ("array types should have matching static bounds", N);
8067 Check_Function_Writable_Actuals (N);
8068 end Resolve_Logical_Op;
8070 ---------------------------
8071 -- Resolve_Membership_Op --
8072 ---------------------------
8074 -- The context can only be a boolean type, and does not determine the
8075 -- arguments. Arguments should be unambiguous, but the preference rule for
8076 -- universal types applies.
8078 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8079 pragma Warnings (Off, Typ);
8081 L : constant Node_Id := Left_Opnd (N);
8082 R : constant Node_Id := Right_Opnd (N);
8085 procedure Resolve_Set_Membership;
8086 -- Analysis has determined a unique type for the left operand. Use it to
8087 -- resolve the disjuncts.
8089 ----------------------------
8090 -- Resolve_Set_Membership --
8091 ----------------------------
8093 procedure Resolve_Set_Membership is
8095 Ltyp : constant Entity_Id := Etype (L);
8100 Alt := First (Alternatives (N));
8101 while Present (Alt) loop
8103 -- Alternative is an expression, a range
8104 -- or a subtype mark.
8106 if not Is_Entity_Name (Alt)
8107 or else not Is_Type (Entity (Alt))
8109 Resolve (Alt, Ltyp);
8115 -- Check for duplicates for discrete case
8117 if Is_Discrete_Type (Ltyp) then
8124 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8128 -- Loop checking duplicates. This is quadratic, but giant sets
8129 -- are unlikely in this context so it's a reasonable choice.
8132 Alt := First (Alternatives (N));
8133 while Present (Alt) loop
8134 if Is_Static_Expression (Alt)
8135 and then (Nkind_In (Alt, N_Integer_Literal,
8136 N_Character_Literal)
8137 or else Nkind (Alt) in N_Has_Entity)
8140 Alts (Nalts) := (Alt, Expr_Value (Alt));
8142 for J in 1 .. Nalts - 1 loop
8143 if Alts (J).Val = Alts (Nalts).Val then
8144 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8145 Error_Msg_N ("duplicate of value given#??", Alt);
8154 end Resolve_Set_Membership;
8156 -- Start of processing for Resolve_Membership_Op
8159 if L = Error or else R = Error then
8163 if Present (Alternatives (N)) then
8164 Resolve_Set_Membership;
8165 Check_Function_Writable_Actuals (N);
8168 elsif not Is_Overloaded (R)
8170 (Etype (R) = Universal_Integer
8172 Etype (R) = Universal_Real)
8173 and then Is_Overloaded (L)
8177 -- Ada 2005 (AI-251): Support the following case:
8179 -- type I is interface;
8180 -- type T is tagged ...
8182 -- function Test (O : I'Class) is
8184 -- return O in T'Class.
8187 -- In this case we have nothing else to do. The membership test will be
8188 -- done at run time.
8190 elsif Ada_Version >= Ada_2005
8191 and then Is_Class_Wide_Type (Etype (L))
8192 and then Is_Interface (Etype (L))
8193 and then Is_Class_Wide_Type (Etype (R))
8194 and then not Is_Interface (Etype (R))
8198 T := Intersect_Types (L, R);
8201 -- If mixed-mode operations are present and operands are all literal,
8202 -- the only interpretation involves Duration, which is probably not
8203 -- the intention of the programmer.
8205 if T = Any_Fixed then
8206 T := Unique_Fixed_Point_Type (N);
8208 if T = Any_Type then
8214 Check_Unset_Reference (L);
8216 if Nkind (R) = N_Range
8217 and then not Is_Scalar_Type (T)
8219 Error_Msg_N ("scalar type required for range", R);
8222 if Is_Entity_Name (R) then
8223 Freeze_Expression (R);
8226 Check_Unset_Reference (R);
8229 Eval_Membership_Op (N);
8230 Check_Function_Writable_Actuals (N);
8231 end Resolve_Membership_Op;
8237 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8238 Loc : constant Source_Ptr := Sloc (N);
8241 -- Handle restriction against anonymous null access values This
8242 -- restriction can be turned off using -gnatdj.
8244 -- Ada 2005 (AI-231): Remove restriction
8246 if Ada_Version < Ada_2005
8247 and then not Debug_Flag_J
8248 and then Ekind (Typ) = E_Anonymous_Access_Type
8249 and then Comes_From_Source (N)
8251 -- In the common case of a call which uses an explicitly null value
8252 -- for an access parameter, give specialized error message.
8254 if Nkind (Parent (N)) in N_Subprogram_Call then
8256 ("null is not allowed as argument for an access parameter", N);
8258 -- Standard message for all other cases (are there any?)
8262 ("null cannot be of an anonymous access type", N);
8266 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8267 -- assignment to a null-excluding object
8269 if Ada_Version >= Ada_2005
8270 and then Can_Never_Be_Null (Typ)
8271 and then Nkind (Parent (N)) = N_Assignment_Statement
8273 if not Inside_Init_Proc then
8275 (Compile_Time_Constraint_Error (N,
8276 "(Ada 2005) null not allowed in null-excluding objects??"),
8277 Make_Raise_Constraint_Error (Loc,
8278 Reason => CE_Access_Check_Failed));
8281 Make_Raise_Constraint_Error (Loc,
8282 Reason => CE_Access_Check_Failed));
8286 -- In a distributed context, null for a remote access to subprogram may
8287 -- need to be replaced with a special record aggregate. In this case,
8288 -- return after having done the transformation.
8290 if (Ekind (Typ) = E_Record_Type
8291 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8292 and then Remote_AST_Null_Value (N, Typ)
8297 -- The null literal takes its type from the context
8302 -----------------------
8303 -- Resolve_Op_Concat --
8304 -----------------------
8306 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8308 -- We wish to avoid deep recursion, because concatenations are often
8309 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8310 -- operands nonrecursively until we find something that is not a simple
8311 -- concatenation (A in this case). We resolve that, and then walk back
8312 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8313 -- to do the rest of the work at each level. The Parent pointers allow
8314 -- us to avoid recursion, and thus avoid running out of memory. See also
8315 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8321 -- The following code is equivalent to:
8323 -- Resolve_Op_Concat_First (NN, Typ);
8324 -- Resolve_Op_Concat_Arg (N, ...);
8325 -- Resolve_Op_Concat_Rest (N, Typ);
8327 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8328 -- operand is a concatenation.
8330 -- Walk down left operands
8333 Resolve_Op_Concat_First (NN, Typ);
8334 Op1 := Left_Opnd (NN);
8335 exit when not (Nkind (Op1) = N_Op_Concat
8336 and then not Is_Array_Type (Component_Type (Typ))
8337 and then Entity (Op1) = Entity (NN));
8341 -- Now (given the above example) NN is A&B and Op1 is A
8343 -- First resolve Op1 ...
8345 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8347 -- ... then walk NN back up until we reach N (where we started), calling
8348 -- Resolve_Op_Concat_Rest along the way.
8351 Resolve_Op_Concat_Rest (NN, Typ);
8356 if Base_Type (Etype (N)) /= Standard_String then
8357 Check_SPARK_Restriction
8358 ("result of concatenation should have type String", N);
8360 end Resolve_Op_Concat;
8362 ---------------------------
8363 -- Resolve_Op_Concat_Arg --
8364 ---------------------------
8366 procedure Resolve_Op_Concat_Arg
8372 Btyp : constant Entity_Id := Base_Type (Typ);
8373 Ctyp : constant Entity_Id := Component_Type (Typ);
8378 or else (not Is_Overloaded (Arg)
8379 and then Etype (Arg) /= Any_Composite
8380 and then Covers (Ctyp, Etype (Arg)))
8382 Resolve (Arg, Ctyp);
8384 Resolve (Arg, Btyp);
8387 -- If both Array & Array and Array & Component are visible, there is a
8388 -- potential ambiguity that must be reported.
8390 elsif Has_Compatible_Type (Arg, Ctyp) then
8391 if Nkind (Arg) = N_Aggregate
8392 and then Is_Composite_Type (Ctyp)
8394 if Is_Private_Type (Ctyp) then
8395 Resolve (Arg, Btyp);
8397 -- If the operation is user-defined and not overloaded use its
8398 -- profile. The operation may be a renaming, in which case it has
8399 -- been rewritten, and we want the original profile.
8401 elsif not Is_Overloaded (N)
8402 and then Comes_From_Source (Entity (Original_Node (N)))
8403 and then Ekind (Entity (Original_Node (N))) = E_Function
8407 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
8410 -- Otherwise an aggregate may match both the array type and the
8414 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
8415 Set_Etype (Arg, Any_Type);
8419 if Is_Overloaded (Arg)
8420 and then Has_Compatible_Type (Arg, Typ)
8421 and then Etype (Arg) /= Any_Type
8429 Get_First_Interp (Arg, I, It);
8431 Get_Next_Interp (I, It);
8433 -- Special-case the error message when the overloading is
8434 -- caused by a function that yields an array and can be
8435 -- called without parameters.
8437 if It.Nam = Func then
8438 Error_Msg_Sloc := Sloc (Func);
8439 Error_Msg_N ("ambiguous call to function#", Arg);
8441 ("\\interpretation as call yields&", Arg, Typ);
8443 ("\\interpretation as indexing of call yields&",
8444 Arg, Component_Type (Typ));
8447 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
8449 Get_First_Interp (Arg, I, It);
8450 while Present (It.Nam) loop
8451 Error_Msg_Sloc := Sloc (It.Nam);
8453 if Base_Type (It.Typ) = Btyp
8455 Base_Type (It.Typ) = Base_Type (Ctyp)
8457 Error_Msg_N -- CODEFIX
8458 ("\\possible interpretation#", Arg);
8461 Get_Next_Interp (I, It);
8467 Resolve (Arg, Component_Type (Typ));
8469 if Nkind (Arg) = N_String_Literal then
8470 Set_Etype (Arg, Component_Type (Typ));
8473 if Arg = Left_Opnd (N) then
8474 Set_Is_Component_Left_Opnd (N);
8476 Set_Is_Component_Right_Opnd (N);
8481 Resolve (Arg, Btyp);
8484 -- Concatenation is restricted in SPARK: each operand must be either a
8485 -- string literal, the name of a string constant, a static character or
8486 -- string expression, or another concatenation. Arg cannot be a
8487 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
8488 -- separately on each final operand, past concatenation operations.
8490 if Is_Character_Type (Etype (Arg)) then
8491 if not Is_Static_Expression (Arg) then
8492 Check_SPARK_Restriction
8493 ("character operand for concatenation should be static", Arg);
8496 elsif Is_String_Type (Etype (Arg)) then
8497 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
8498 and then Is_Constant_Object (Entity (Arg)))
8499 and then not Is_Static_Expression (Arg)
8501 Check_SPARK_Restriction
8502 ("string operand for concatenation should be static", Arg);
8505 -- Do not issue error on an operand that is neither a character nor a
8506 -- string, as the error is issued in Resolve_Op_Concat.
8512 Check_Unset_Reference (Arg);
8513 end Resolve_Op_Concat_Arg;
8515 -----------------------------
8516 -- Resolve_Op_Concat_First --
8517 -----------------------------
8519 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
8520 Btyp : constant Entity_Id := Base_Type (Typ);
8521 Op1 : constant Node_Id := Left_Opnd (N);
8522 Op2 : constant Node_Id := Right_Opnd (N);
8525 -- The parser folds an enormous sequence of concatenations of string
8526 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
8527 -- in the right operand. If the expression resolves to a predefined "&"
8528 -- operator, all is well. Otherwise, the parser's folding is wrong, so
8529 -- we give an error. See P_Simple_Expression in Par.Ch4.
8531 if Nkind (Op2) = N_String_Literal
8532 and then Is_Folded_In_Parser (Op2)
8533 and then Ekind (Entity (N)) = E_Function
8535 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
8536 and then String_Length (Strval (Op1)) = 0);
8537 Error_Msg_N ("too many user-defined concatenations", N);
8541 Set_Etype (N, Btyp);
8543 if Is_Limited_Composite (Btyp) then
8544 Error_Msg_N ("concatenation not available for limited array", N);
8545 Explain_Limited_Type (Btyp, N);
8547 end Resolve_Op_Concat_First;
8549 ----------------------------
8550 -- Resolve_Op_Concat_Rest --
8551 ----------------------------
8553 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
8554 Op1 : constant Node_Id := Left_Opnd (N);
8555 Op2 : constant Node_Id := Right_Opnd (N);
8558 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
8560 Generate_Operator_Reference (N, Typ);
8562 if Is_String_Type (Typ) then
8563 Eval_Concatenation (N);
8566 -- If this is not a static concatenation, but the result is a string
8567 -- type (and not an array of strings) ensure that static string operands
8568 -- have their subtypes properly constructed.
8570 if Nkind (N) /= N_String_Literal
8571 and then Is_Character_Type (Component_Type (Typ))
8573 Set_String_Literal_Subtype (Op1, Typ);
8574 Set_String_Literal_Subtype (Op2, Typ);
8576 end Resolve_Op_Concat_Rest;
8578 ----------------------
8579 -- Resolve_Op_Expon --
8580 ----------------------
8582 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
8583 B_Typ : constant Entity_Id := Base_Type (Typ);
8586 -- Catch attempts to do fixed-point exponentiation with universal
8587 -- operands, which is a case where the illegality is not caught during
8588 -- normal operator analysis. This is not done in preanalysis mode
8589 -- since the tree is not fully decorated during preanalysis.
8591 if Full_Analysis then
8592 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
8593 Error_Msg_N ("exponentiation not available for fixed point", N);
8596 elsif Nkind (Parent (N)) in N_Op
8597 and then Is_Fixed_Point_Type (Etype (Parent (N)))
8598 and then Etype (N) = Universal_Real
8599 and then Comes_From_Source (N)
8601 Error_Msg_N ("exponentiation not available for fixed point", N);
8606 if Comes_From_Source (N)
8607 and then Ekind (Entity (N)) = E_Function
8608 and then Is_Imported (Entity (N))
8609 and then Is_Intrinsic_Subprogram (Entity (N))
8611 Resolve_Intrinsic_Operator (N, Typ);
8615 if Etype (Left_Opnd (N)) = Universal_Integer
8616 or else Etype (Left_Opnd (N)) = Universal_Real
8618 Check_For_Visible_Operator (N, B_Typ);
8621 -- We do the resolution using the base type, because intermediate values
8622 -- in expressions are always of the base type, not a subtype of it.
8624 Resolve (Left_Opnd (N), B_Typ);
8625 Resolve (Right_Opnd (N), Standard_Integer);
8627 -- For integer types, right argument must be in Natural range
8629 if Is_Integer_Type (Typ) then
8630 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
8633 Check_Unset_Reference (Left_Opnd (N));
8634 Check_Unset_Reference (Right_Opnd (N));
8636 Set_Etype (N, B_Typ);
8637 Generate_Operator_Reference (N, B_Typ);
8639 Analyze_Dimension (N);
8641 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
8642 -- Evaluate the exponentiation operator for dimensioned type
8644 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
8649 -- Set overflow checking bit. Much cleverer code needed here eventually
8650 -- and perhaps the Resolve routines should be separated for the various
8651 -- arithmetic operations, since they will need different processing. ???
8653 if Nkind (N) in N_Op then
8654 if not Overflow_Checks_Suppressed (Etype (N)) then
8655 Enable_Overflow_Check (N);
8658 end Resolve_Op_Expon;
8660 --------------------
8661 -- Resolve_Op_Not --
8662 --------------------
8664 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
8667 function Parent_Is_Boolean return Boolean;
8668 -- This function determines if the parent node is a boolean operator or
8669 -- operation (comparison op, membership test, or short circuit form) and
8670 -- the not in question is the left operand of this operation. Note that
8671 -- if the not is in parens, then false is returned.
8673 -----------------------
8674 -- Parent_Is_Boolean --
8675 -----------------------
8677 function Parent_Is_Boolean return Boolean is
8679 if Paren_Count (N) /= 0 then
8683 case Nkind (Parent (N)) is
8698 return Left_Opnd (Parent (N)) = N;
8704 end Parent_Is_Boolean;
8706 -- Start of processing for Resolve_Op_Not
8709 -- Predefined operations on scalar types yield the base type. On the
8710 -- other hand, logical operations on arrays yield the type of the
8711 -- arguments (and the context).
8713 if Is_Array_Type (Typ) then
8716 B_Typ := Base_Type (Typ);
8719 if Is_VMS_Operator (Entity (N)) then
8722 -- Straightforward case of incorrect arguments
8724 elsif not Valid_Boolean_Arg (Typ) then
8725 Error_Msg_N ("invalid operand type for operator&", N);
8726 Set_Etype (N, Any_Type);
8729 -- Special case of probable missing parens
8731 elsif Typ = Universal_Integer or else Typ = Any_Modular then
8732 if Parent_Is_Boolean then
8734 ("operand of not must be enclosed in parentheses",
8738 ("no modular type available in this context", N);
8741 Set_Etype (N, Any_Type);
8744 -- OK resolution of NOT
8747 -- Warn if non-boolean types involved. This is a case like not a < b
8748 -- where a and b are modular, where we will get (not a) < b and most
8749 -- likely not (a < b) was intended.
8751 if Warn_On_Questionable_Missing_Parens
8752 and then not Is_Boolean_Type (Typ)
8753 and then Parent_Is_Boolean
8755 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
8758 -- Warn on double negation if checking redundant constructs
8760 if Warn_On_Redundant_Constructs
8761 and then Comes_From_Source (N)
8762 and then Comes_From_Source (Right_Opnd (N))
8763 and then Root_Type (Typ) = Standard_Boolean
8764 and then Nkind (Right_Opnd (N)) = N_Op_Not
8766 Error_Msg_N ("redundant double negation?r?", N);
8769 -- Complete resolution and evaluation of NOT
8771 Resolve (Right_Opnd (N), B_Typ);
8772 Check_Unset_Reference (Right_Opnd (N));
8773 Set_Etype (N, B_Typ);
8774 Generate_Operator_Reference (N, B_Typ);
8779 -----------------------------
8780 -- Resolve_Operator_Symbol --
8781 -----------------------------
8783 -- Nothing to be done, all resolved already
8785 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
8786 pragma Warnings (Off, N);
8787 pragma Warnings (Off, Typ);
8791 end Resolve_Operator_Symbol;
8793 ----------------------------------
8794 -- Resolve_Qualified_Expression --
8795 ----------------------------------
8797 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
8798 pragma Warnings (Off, Typ);
8800 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
8801 Expr : constant Node_Id := Expression (N);
8804 Resolve (Expr, Target_Typ);
8806 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8807 -- operation if not needed.
8809 if Restriction_Check_Required (SPARK_05)
8810 and then Is_Array_Type (Target_Typ)
8811 and then Is_Array_Type (Etype (Expr))
8812 and then Etype (Expr) /= Any_Composite -- or else Expr in error
8813 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
8815 Check_SPARK_Restriction
8816 ("array types should have matching static bounds", N);
8819 -- A qualified expression requires an exact match of the type, class-
8820 -- wide matching is not allowed. However, if the qualifying type is
8821 -- specific and the expression has a class-wide type, it may still be
8822 -- okay, since it can be the result of the expansion of a call to a
8823 -- dispatching function, so we also have to check class-wideness of the
8824 -- type of the expression's original node.
8826 if (Is_Class_Wide_Type (Target_Typ)
8828 (Is_Class_Wide_Type (Etype (Expr))
8829 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
8830 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
8832 Wrong_Type (Expr, Target_Typ);
8835 -- If the target type is unconstrained, then we reset the type of the
8836 -- result from the type of the expression. For other cases, the actual
8837 -- subtype of the expression is the target type.
8839 if Is_Composite_Type (Target_Typ)
8840 and then not Is_Constrained (Target_Typ)
8842 Set_Etype (N, Etype (Expr));
8845 Analyze_Dimension (N);
8846 Eval_Qualified_Expression (N);
8847 end Resolve_Qualified_Expression;
8849 ------------------------------
8850 -- Resolve_Raise_Expression --
8851 ------------------------------
8853 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
8855 if Typ = Raise_Type then
8856 Error_Msg_N ("cannot find unique type for raise expression", N);
8857 Set_Etype (N, Any_Type);
8861 end Resolve_Raise_Expression;
8867 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
8868 L : constant Node_Id := Low_Bound (N);
8869 H : constant Node_Id := High_Bound (N);
8871 function First_Last_Ref return Boolean;
8872 -- Returns True if N is of the form X'First .. X'Last where X is the
8873 -- same entity for both attributes.
8875 --------------------
8876 -- First_Last_Ref --
8877 --------------------
8879 function First_Last_Ref return Boolean is
8880 Lorig : constant Node_Id := Original_Node (L);
8881 Horig : constant Node_Id := Original_Node (H);
8884 if Nkind (Lorig) = N_Attribute_Reference
8885 and then Nkind (Horig) = N_Attribute_Reference
8886 and then Attribute_Name (Lorig) = Name_First
8887 and then Attribute_Name (Horig) = Name_Last
8890 PL : constant Node_Id := Prefix (Lorig);
8891 PH : constant Node_Id := Prefix (Horig);
8893 if Is_Entity_Name (PL)
8894 and then Is_Entity_Name (PH)
8895 and then Entity (PL) = Entity (PH)
8905 -- Start of processing for Resolve_Range
8912 -- Check for inappropriate range on unordered enumeration type
8914 if Bad_Unordered_Enumeration_Reference (N, Typ)
8916 -- Exclude X'First .. X'Last if X is the same entity for both
8918 and then not First_Last_Ref
8920 Error_Msg_Sloc := Sloc (Typ);
8922 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
8925 Check_Unset_Reference (L);
8926 Check_Unset_Reference (H);
8928 -- We have to check the bounds for being within the base range as
8929 -- required for a non-static context. Normally this is automatic and
8930 -- done as part of evaluating expressions, but the N_Range node is an
8931 -- exception, since in GNAT we consider this node to be a subexpression,
8932 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8933 -- this, but that would put the test on the main evaluation path for
8936 Check_Non_Static_Context (L);
8937 Check_Non_Static_Context (H);
8939 -- Check for an ambiguous range over character literals. This will
8940 -- happen with a membership test involving only literals.
8942 if Typ = Any_Character then
8943 Ambiguous_Character (L);
8944 Set_Etype (N, Any_Type);
8948 -- If bounds are static, constant-fold them, so size computations are
8949 -- identical between front-end and back-end. Do not perform this
8950 -- transformation while analyzing generic units, as type information
8951 -- would be lost when reanalyzing the constant node in the instance.
8953 if Is_Discrete_Type (Typ) and then Expander_Active then
8954 if Is_OK_Static_Expression (L) then
8955 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8958 if Is_OK_Static_Expression (H) then
8959 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8964 --------------------------
8965 -- Resolve_Real_Literal --
8966 --------------------------
8968 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8969 Actual_Typ : constant Entity_Id := Etype (N);
8972 -- Special processing for fixed-point literals to make sure that the
8973 -- value is an exact multiple of small where this is required. We skip
8974 -- this for the universal real case, and also for generic types.
8976 if Is_Fixed_Point_Type (Typ)
8977 and then Typ /= Universal_Fixed
8978 and then Typ /= Any_Fixed
8979 and then not Is_Generic_Type (Typ)
8982 Val : constant Ureal := Realval (N);
8983 Cintr : constant Ureal := Val / Small_Value (Typ);
8984 Cint : constant Uint := UR_Trunc (Cintr);
8985 Den : constant Uint := Norm_Den (Cintr);
8989 -- Case of literal is not an exact multiple of the Small
8993 -- For a source program literal for a decimal fixed-point type,
8994 -- this is statically illegal (RM 4.9(36)).
8996 if Is_Decimal_Fixed_Point_Type (Typ)
8997 and then Actual_Typ = Universal_Real
8998 and then Comes_From_Source (N)
9000 Error_Msg_N ("value has extraneous low order digits", N);
9003 -- Generate a warning if literal from source
9005 if Is_Static_Expression (N)
9006 and then Warn_On_Bad_Fixed_Value
9009 ("?b?static fixed-point value is not a multiple of Small!",
9013 -- Replace literal by a value that is the exact representation
9014 -- of a value of the type, i.e. a multiple of the small value,
9015 -- by truncation, since Machine_Rounds is false for all GNAT
9016 -- fixed-point types (RM 4.9(38)).
9018 Stat := Is_Static_Expression (N);
9020 Make_Real_Literal (Sloc (N),
9021 Realval => Small_Value (Typ) * Cint));
9023 Set_Is_Static_Expression (N, Stat);
9026 -- In all cases, set the corresponding integer field
9028 Set_Corresponding_Integer_Value (N, Cint);
9032 -- Now replace the actual type by the expected type as usual
9035 Eval_Real_Literal (N);
9036 end Resolve_Real_Literal;
9038 -----------------------
9039 -- Resolve_Reference --
9040 -----------------------
9042 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9043 P : constant Node_Id := Prefix (N);
9046 -- Replace general access with specific type
9048 if Ekind (Etype (N)) = E_Allocator_Type then
9049 Set_Etype (N, Base_Type (Typ));
9052 Resolve (P, Designated_Type (Etype (N)));
9054 -- If we are taking the reference of a volatile entity, then treat it as
9055 -- a potential modification of this entity. This is too conservative,
9056 -- but necessary because remove side effects can cause transformations
9057 -- of normal assignments into reference sequences that otherwise fail to
9058 -- notice the modification.
9060 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9061 Note_Possible_Modification (P, Sure => False);
9063 end Resolve_Reference;
9065 --------------------------------
9066 -- Resolve_Selected_Component --
9067 --------------------------------
9069 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9071 Comp1 : Entity_Id := Empty; -- prevent junk warning
9072 P : constant Node_Id := Prefix (N);
9073 S : constant Node_Id := Selector_Name (N);
9074 T : Entity_Id := Etype (P);
9076 I1 : Interp_Index := 0; -- prevent junk warning
9081 function Init_Component return Boolean;
9082 -- Check whether this is the initialization of a component within an
9083 -- init proc (by assignment or call to another init proc). If true,
9084 -- there is no need for a discriminant check.
9086 --------------------
9087 -- Init_Component --
9088 --------------------
9090 function Init_Component return Boolean is
9092 return Inside_Init_Proc
9093 and then Nkind (Prefix (N)) = N_Identifier
9094 and then Chars (Prefix (N)) = Name_uInit
9095 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9098 -- Start of processing for Resolve_Selected_Component
9101 if Is_Overloaded (P) then
9103 -- Use the context type to select the prefix that has a selector
9104 -- of the correct name and type.
9107 Get_First_Interp (P, I, It);
9109 Search : while Present (It.Typ) loop
9110 if Is_Access_Type (It.Typ) then
9111 T := Designated_Type (It.Typ);
9116 -- Locate selected component. For a private prefix the selector
9117 -- can denote a discriminant.
9119 if Is_Record_Type (T) or else Is_Private_Type (T) then
9121 -- The visible components of a class-wide type are those of
9124 if Is_Class_Wide_Type (T) then
9128 Comp := First_Entity (T);
9129 while Present (Comp) loop
9130 if Chars (Comp) = Chars (S)
9131 and then Covers (Typ, Etype (Comp))
9140 It := Disambiguate (P, I1, I, Any_Type);
9142 if It = No_Interp then
9144 ("ambiguous prefix for selected component", N);
9151 -- There may be an implicit dereference. Retrieve
9152 -- designated record type.
9154 if Is_Access_Type (It1.Typ) then
9155 T := Designated_Type (It1.Typ);
9160 if Scope (Comp1) /= T then
9162 -- Resolution chooses the new interpretation.
9163 -- Find the component with the right name.
9165 Comp1 := First_Entity (T);
9166 while Present (Comp1)
9167 and then Chars (Comp1) /= Chars (S)
9169 Comp1 := Next_Entity (Comp1);
9178 Comp := Next_Entity (Comp);
9182 Get_Next_Interp (I, It);
9185 -- There must be a legal interpretation at this point
9187 pragma Assert (Found);
9188 Resolve (P, It1.Typ);
9190 Set_Entity_With_Checks (S, Comp1);
9193 -- Resolve prefix with its type
9198 -- Generate cross-reference. We needed to wait until full overloading
9199 -- resolution was complete to do this, since otherwise we can't tell if
9200 -- we are an lvalue or not.
9202 if May_Be_Lvalue (N) then
9203 Generate_Reference (Entity (S), S, 'm');
9205 Generate_Reference (Entity (S), S, 'r');
9208 -- If prefix is an access type, the node will be transformed into an
9209 -- explicit dereference during expansion. The type of the node is the
9210 -- designated type of that of the prefix.
9212 if Is_Access_Type (Etype (P)) then
9213 T := Designated_Type (Etype (P));
9214 Check_Fully_Declared_Prefix (T, P);
9219 -- Set flag for expander if discriminant check required
9221 if Has_Discriminants (T)
9222 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
9223 and then Present (Original_Record_Component (Entity (S)))
9224 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9225 and then not Discriminant_Checks_Suppressed (T)
9226 and then not Init_Component
9228 Set_Do_Discriminant_Check (N);
9231 if Ekind (Entity (S)) = E_Void then
9232 Error_Msg_N ("premature use of component", S);
9235 -- If the prefix is a record conversion, this may be a renamed
9236 -- discriminant whose bounds differ from those of the original
9237 -- one, so we must ensure that a range check is performed.
9239 if Nkind (P) = N_Type_Conversion
9240 and then Ekind (Entity (S)) = E_Discriminant
9241 and then Is_Discrete_Type (Typ)
9243 Set_Etype (N, Base_Type (Typ));
9246 -- Note: No Eval processing is required, because the prefix is of a
9247 -- record type, or protected type, and neither can possibly be static.
9249 -- If the array type is atomic, and is packed, and we are in a left side
9250 -- context, then this is worth a warning, since we have a situation
9251 -- where the access to the component may cause extra read/writes of the
9252 -- atomic array object, which could be considered unexpected.
9254 if Nkind (N) = N_Selected_Component
9255 and then (Is_Atomic (T)
9256 or else (Is_Entity_Name (Prefix (N))
9257 and then Is_Atomic (Entity (Prefix (N)))))
9258 and then Is_Packed (T)
9259 and then Is_LHS (N) = Yes
9262 ("??assignment to component of packed atomic record", Prefix (N));
9264 ("\??may cause unexpected accesses to atomic object", Prefix (N));
9267 Analyze_Dimension (N);
9268 end Resolve_Selected_Component;
9274 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9275 B_Typ : constant Entity_Id := Base_Type (Typ);
9276 L : constant Node_Id := Left_Opnd (N);
9277 R : constant Node_Id := Right_Opnd (N);
9280 -- We do the resolution using the base type, because intermediate values
9281 -- in expressions always are of the base type, not a subtype of it.
9284 Resolve (R, Standard_Natural);
9286 Check_Unset_Reference (L);
9287 Check_Unset_Reference (R);
9289 Set_Etype (N, B_Typ);
9290 Generate_Operator_Reference (N, B_Typ);
9294 ---------------------------
9295 -- Resolve_Short_Circuit --
9296 ---------------------------
9298 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9299 B_Typ : constant Entity_Id := Base_Type (Typ);
9300 L : constant Node_Id := Left_Opnd (N);
9301 R : constant Node_Id := Right_Opnd (N);
9304 -- Ensure all actions associated with the left operand (e.g.
9305 -- finalization of transient controlled objects) are fully evaluated
9306 -- locally within an expression with actions. This is particularly
9307 -- helpful for coverage analysis. However this should not happen in
9310 if Expander_Active then
9312 Reloc_L : constant Node_Id := Relocate_Node (L);
9314 Save_Interps (Old_N => L, New_N => Reloc_L);
9317 Make_Expression_With_Actions (Sloc (L),
9318 Actions => New_List,
9319 Expression => Reloc_L));
9321 -- Set Comes_From_Source on L to preserve warnings for unset
9324 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9331 -- Check for issuing warning for always False assert/check, this happens
9332 -- when assertions are turned off, in which case the pragma Assert/Check
9333 -- was transformed into:
9335 -- if False and then <condition> then ...
9337 -- and we detect this pattern
9339 if Warn_On_Assertion_Failure
9340 and then Is_Entity_Name (R)
9341 and then Entity (R) = Standard_False
9342 and then Nkind (Parent (N)) = N_If_Statement
9343 and then Nkind (N) = N_And_Then
9344 and then Is_Entity_Name (L)
9345 and then Entity (L) = Standard_False
9348 Orig : constant Node_Id := Original_Node (Parent (N));
9351 -- Special handling of Asssert pragma
9353 if Nkind (Orig) = N_Pragma
9354 and then Pragma_Name (Orig) = Name_Assert
9357 Expr : constant Node_Id :=
9360 (First (Pragma_Argument_Associations (Orig))));
9363 -- Don't warn if original condition is explicit False,
9364 -- since obviously the failure is expected in this case.
9366 if Is_Entity_Name (Expr)
9367 and then Entity (Expr) = Standard_False
9371 -- Issue warning. We do not want the deletion of the
9372 -- IF/AND-THEN to take this message with it. We achieve this
9373 -- by making sure that the expanded code points to the Sloc
9374 -- of the expression, not the original pragma.
9377 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
9378 -- The source location of the expression is not usually
9379 -- the best choice here. For example, it gets located on
9380 -- the last AND keyword in a chain of boolean expressiond
9381 -- AND'ed together. It is best to put the message on the
9382 -- first character of the assertion, which is the effect
9383 -- of the First_Node call here.
9386 ("?A?assertion would fail at run time!",
9388 (First (Pragma_Argument_Associations (Orig))));
9392 -- Similar processing for Check pragma
9394 elsif Nkind (Orig) = N_Pragma
9395 and then Pragma_Name (Orig) = Name_Check
9397 -- Don't want to warn if original condition is explicit False
9400 Expr : constant Node_Id :=
9403 (Next (First (Pragma_Argument_Associations (Orig)))));
9405 if Is_Entity_Name (Expr)
9406 and then Entity (Expr) = Standard_False
9413 -- Again use Error_Msg_F rather than Error_Msg_N, see
9414 -- comment above for an explanation of why we do this.
9417 ("?A?check would fail at run time!",
9419 (Last (Pragma_Argument_Associations (Orig))));
9426 -- Continue with processing of short circuit
9428 Check_Unset_Reference (L);
9429 Check_Unset_Reference (R);
9431 Set_Etype (N, B_Typ);
9432 Eval_Short_Circuit (N);
9433 end Resolve_Short_Circuit;
9439 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
9440 Drange : constant Node_Id := Discrete_Range (N);
9441 Name : constant Node_Id := Prefix (N);
9442 Array_Type : Entity_Id := Empty;
9443 Dexpr : Node_Id := Empty;
9444 Index_Type : Entity_Id;
9447 if Is_Overloaded (Name) then
9449 -- Use the context type to select the prefix that yields the correct
9454 I1 : Interp_Index := 0;
9456 P : constant Node_Id := Prefix (N);
9457 Found : Boolean := False;
9460 Get_First_Interp (P, I, It);
9461 while Present (It.Typ) loop
9462 if (Is_Array_Type (It.Typ)
9463 and then Covers (Typ, It.Typ))
9464 or else (Is_Access_Type (It.Typ)
9465 and then Is_Array_Type (Designated_Type (It.Typ))
9466 and then Covers (Typ, Designated_Type (It.Typ)))
9469 It := Disambiguate (P, I1, I, Any_Type);
9471 if It = No_Interp then
9472 Error_Msg_N ("ambiguous prefix for slicing", N);
9477 Array_Type := It.Typ;
9482 Array_Type := It.Typ;
9487 Get_Next_Interp (I, It);
9492 Array_Type := Etype (Name);
9495 Resolve (Name, Array_Type);
9497 if Is_Access_Type (Array_Type) then
9498 Apply_Access_Check (N);
9499 Array_Type := Designated_Type (Array_Type);
9501 -- If the prefix is an access to an unconstrained array, we must use
9502 -- the actual subtype of the object to perform the index checks. The
9503 -- object denoted by the prefix is implicit in the node, so we build
9504 -- an explicit representation for it in order to compute the actual
9507 if not Is_Constrained (Array_Type) then
9508 Remove_Side_Effects (Prefix (N));
9511 Obj : constant Node_Id :=
9512 Make_Explicit_Dereference (Sloc (N),
9513 Prefix => New_Copy_Tree (Prefix (N)));
9515 Set_Etype (Obj, Array_Type);
9516 Set_Parent (Obj, Parent (N));
9517 Array_Type := Get_Actual_Subtype (Obj);
9521 elsif Is_Entity_Name (Name)
9522 or else Nkind (Name) = N_Explicit_Dereference
9523 or else (Nkind (Name) = N_Function_Call
9524 and then not Is_Constrained (Etype (Name)))
9526 Array_Type := Get_Actual_Subtype (Name);
9528 -- If the name is a selected component that depends on discriminants,
9529 -- build an actual subtype for it. This can happen only when the name
9530 -- itself is overloaded; otherwise the actual subtype is created when
9531 -- the selected component is analyzed.
9533 elsif Nkind (Name) = N_Selected_Component
9534 and then Full_Analysis
9535 and then Depends_On_Discriminant (First_Index (Array_Type))
9538 Act_Decl : constant Node_Id :=
9539 Build_Actual_Subtype_Of_Component (Array_Type, Name);
9541 Insert_Action (N, Act_Decl);
9542 Array_Type := Defining_Identifier (Act_Decl);
9545 -- Maybe this should just be "else", instead of checking for the
9546 -- specific case of slice??? This is needed for the case where the
9547 -- prefix is an Image attribute, which gets expanded to a slice, and so
9548 -- has a constrained subtype which we want to use for the slice range
9549 -- check applied below (the range check won't get done if the
9550 -- unconstrained subtype of the 'Image is used).
9552 elsif Nkind (Name) = N_Slice then
9553 Array_Type := Etype (Name);
9556 -- Obtain the type of the array index
9558 if Ekind (Array_Type) = E_String_Literal_Subtype then
9559 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
9561 Index_Type := Etype (First_Index (Array_Type));
9564 -- If name was overloaded, set slice type correctly now
9566 Set_Etype (N, Array_Type);
9568 -- Handle the generation of a range check that compares the array index
9569 -- against the discrete_range. The check is not applied to internally
9570 -- built nodes associated with the expansion of dispatch tables. Check
9571 -- that Ada.Tags has already been loaded to avoid extra dependencies on
9574 if Tagged_Type_Expansion
9575 and then RTU_Loaded (Ada_Tags)
9576 and then Nkind (Prefix (N)) = N_Selected_Component
9577 and then Present (Entity (Selector_Name (Prefix (N))))
9578 and then Entity (Selector_Name (Prefix (N))) =
9579 RTE_Record_Component (RE_Prims_Ptr)
9583 -- The discrete_range is specified by a subtype indication. Create a
9584 -- shallow copy and inherit the type, parent and source location from
9585 -- the discrete_range. This ensures that the range check is inserted
9586 -- relative to the slice and that the runtime exception points to the
9587 -- proper construct.
9589 elsif Is_Entity_Name (Drange) then
9590 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
9592 Set_Etype (Dexpr, Etype (Drange));
9593 Set_Parent (Dexpr, Parent (Drange));
9594 Set_Sloc (Dexpr, Sloc (Drange));
9596 -- The discrete_range is a regular range. Resolve the bounds and remove
9597 -- their side effects.
9600 Resolve (Drange, Base_Type (Index_Type));
9602 if Nkind (Drange) = N_Range then
9603 Force_Evaluation (Low_Bound (Drange));
9604 Force_Evaluation (High_Bound (Drange));
9610 if Present (Dexpr) then
9611 Apply_Range_Check (Dexpr, Index_Type);
9614 Set_Slice_Subtype (N);
9616 -- Check bad use of type with predicates
9618 if Has_Predicates (Etype (Drange)) then
9619 Bad_Predicated_Subtype_Use
9620 ("subtype& has predicate, not allowed in slice",
9621 Drange, Etype (Drange));
9623 -- Otherwise here is where we check suspicious indexes
9625 elsif Nkind (Drange) = N_Range then
9626 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
9627 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
9630 Analyze_Dimension (N);
9634 ----------------------------
9635 -- Resolve_String_Literal --
9636 ----------------------------
9638 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
9639 C_Typ : constant Entity_Id := Component_Type (Typ);
9640 R_Typ : constant Entity_Id := Root_Type (C_Typ);
9641 Loc : constant Source_Ptr := Sloc (N);
9642 Str : constant String_Id := Strval (N);
9643 Strlen : constant Nat := String_Length (Str);
9644 Subtype_Id : Entity_Id;
9645 Need_Check : Boolean;
9648 -- For a string appearing in a concatenation, defer creation of the
9649 -- string_literal_subtype until the end of the resolution of the
9650 -- concatenation, because the literal may be constant-folded away. This
9651 -- is a useful optimization for long concatenation expressions.
9653 -- If the string is an aggregate built for a single character (which
9654 -- happens in a non-static context) or a is null string to which special
9655 -- checks may apply, we build the subtype. Wide strings must also get a
9656 -- string subtype if they come from a one character aggregate. Strings
9657 -- generated by attributes might be static, but it is often hard to
9658 -- determine whether the enclosing context is static, so we generate
9659 -- subtypes for them as well, thus losing some rarer optimizations ???
9660 -- Same for strings that come from a static conversion.
9663 (Strlen = 0 and then Typ /= Standard_String)
9664 or else Nkind (Parent (N)) /= N_Op_Concat
9665 or else (N /= Left_Opnd (Parent (N))
9666 and then N /= Right_Opnd (Parent (N)))
9667 or else ((Typ = Standard_Wide_String
9668 or else Typ = Standard_Wide_Wide_String)
9669 and then Nkind (Original_Node (N)) /= N_String_Literal);
9671 -- If the resolving type is itself a string literal subtype, we can just
9672 -- reuse it, since there is no point in creating another.
9674 if Ekind (Typ) = E_String_Literal_Subtype then
9677 elsif Nkind (Parent (N)) = N_Op_Concat
9678 and then not Need_Check
9679 and then not Nkind_In (Original_Node (N), N_Character_Literal,
9680 N_Attribute_Reference,
9681 N_Qualified_Expression,
9686 -- Otherwise we must create a string literal subtype. Note that the
9687 -- whole idea of string literal subtypes is simply to avoid the need
9688 -- for building a full fledged array subtype for each literal.
9691 Set_String_Literal_Subtype (N, Typ);
9692 Subtype_Id := Etype (N);
9695 if Nkind (Parent (N)) /= N_Op_Concat
9698 Set_Etype (N, Subtype_Id);
9699 Eval_String_Literal (N);
9702 if Is_Limited_Composite (Typ)
9703 or else Is_Private_Composite (Typ)
9705 Error_Msg_N ("string literal not available for private array", N);
9706 Set_Etype (N, Any_Type);
9710 -- The validity of a null string has been checked in the call to
9711 -- Eval_String_Literal.
9716 -- Always accept string literal with component type Any_Character, which
9717 -- occurs in error situations and in comparisons of literals, both of
9718 -- which should accept all literals.
9720 elsif R_Typ = Any_Character then
9723 -- If the type is bit-packed, then we always transform the string
9724 -- literal into a full fledged aggregate.
9726 elsif Is_Bit_Packed_Array (Typ) then
9729 -- Deal with cases of Wide_Wide_String, Wide_String, and String
9732 -- For Standard.Wide_Wide_String, or any other type whose component
9733 -- type is Standard.Wide_Wide_Character, we know that all the
9734 -- characters in the string must be acceptable, since the parser
9735 -- accepted the characters as valid character literals.
9737 if R_Typ = Standard_Wide_Wide_Character then
9740 -- For the case of Standard.String, or any other type whose component
9741 -- type is Standard.Character, we must make sure that there are no
9742 -- wide characters in the string, i.e. that it is entirely composed
9743 -- of characters in range of type Character.
9745 -- If the string literal is the result of a static concatenation, the
9746 -- test has already been performed on the components, and need not be
9749 elsif R_Typ = Standard_Character
9750 and then Nkind (Original_Node (N)) /= N_Op_Concat
9752 for J in 1 .. Strlen loop
9753 if not In_Character_Range (Get_String_Char (Str, J)) then
9755 -- If we are out of range, post error. This is one of the
9756 -- very few places that we place the flag in the middle of
9757 -- a token, right under the offending wide character. Not
9758 -- quite clear if this is right wrt wide character encoding
9759 -- sequences, but it's only an error message.
9762 ("literal out of range of type Standard.Character",
9763 Source_Ptr (Int (Loc) + J));
9768 -- For the case of Standard.Wide_String, or any other type whose
9769 -- component type is Standard.Wide_Character, we must make sure that
9770 -- there are no wide characters in the string, i.e. that it is
9771 -- entirely composed of characters in range of type Wide_Character.
9773 -- If the string literal is the result of a static concatenation,
9774 -- the test has already been performed on the components, and need
9777 elsif R_Typ = Standard_Wide_Character
9778 and then Nkind (Original_Node (N)) /= N_Op_Concat
9780 for J in 1 .. Strlen loop
9781 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
9783 -- If we are out of range, post error. This is one of the
9784 -- very few places that we place the flag in the middle of
9785 -- a token, right under the offending wide character.
9787 -- This is not quite right, because characters in general
9788 -- will take more than one character position ???
9791 ("literal out of range of type Standard.Wide_Character",
9792 Source_Ptr (Int (Loc) + J));
9797 -- If the root type is not a standard character, then we will convert
9798 -- the string into an aggregate and will let the aggregate code do
9799 -- the checking. Standard Wide_Wide_Character is also OK here.
9805 -- See if the component type of the array corresponding to the string
9806 -- has compile time known bounds. If yes we can directly check
9807 -- whether the evaluation of the string will raise constraint error.
9808 -- Otherwise we need to transform the string literal into the
9809 -- corresponding character aggregate and let the aggregate code do
9812 if Is_Standard_Character_Type (R_Typ) then
9814 -- Check for the case of full range, where we are definitely OK
9816 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
9820 -- Here the range is not the complete base type range, so check
9823 Comp_Typ_Lo : constant Node_Id :=
9824 Type_Low_Bound (Component_Type (Typ));
9825 Comp_Typ_Hi : constant Node_Id :=
9826 Type_High_Bound (Component_Type (Typ));
9831 if Compile_Time_Known_Value (Comp_Typ_Lo)
9832 and then Compile_Time_Known_Value (Comp_Typ_Hi)
9834 for J in 1 .. Strlen loop
9835 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
9837 if Char_Val < Expr_Value (Comp_Typ_Lo)
9838 or else Char_Val > Expr_Value (Comp_Typ_Hi)
9840 Apply_Compile_Time_Constraint_Error
9841 (N, "character out of range??",
9842 CE_Range_Check_Failed,
9843 Loc => Source_Ptr (Int (Loc) + J));
9853 -- If we got here we meed to transform the string literal into the
9854 -- equivalent qualified positional array aggregate. This is rather
9855 -- heavy artillery for this situation, but it is hard work to avoid.
9858 Lits : constant List_Id := New_List;
9859 P : Source_Ptr := Loc + 1;
9863 -- Build the character literals, we give them source locations that
9864 -- correspond to the string positions, which is a bit tricky given
9865 -- the possible presence of wide character escape sequences.
9867 for J in 1 .. Strlen loop
9868 C := Get_String_Char (Str, J);
9869 Set_Character_Literal_Name (C);
9872 Make_Character_Literal (P,
9874 Char_Literal_Value => UI_From_CC (C)));
9876 if In_Character_Range (C) then
9879 -- Should we have a call to Skip_Wide here ???
9888 Make_Qualified_Expression (Loc,
9889 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
9891 Make_Aggregate (Loc, Expressions => Lits)));
9893 Analyze_And_Resolve (N, Typ);
9895 end Resolve_String_Literal;
9897 -----------------------------
9898 -- Resolve_Type_Conversion --
9899 -----------------------------
9901 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
9902 Conv_OK : constant Boolean := Conversion_OK (N);
9903 Operand : constant Node_Id := Expression (N);
9904 Operand_Typ : constant Entity_Id := Etype (Operand);
9905 Target_Typ : constant Entity_Id := Etype (N);
9910 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
9911 -- Set to False to suppress cases where we want to suppress the test
9912 -- for redundancy to avoid possible false positives on this warning.
9916 and then not Valid_Conversion (N, Target_Typ, Operand)
9921 -- If the Operand Etype is Universal_Fixed, then the conversion is
9922 -- never redundant. We need this check because by the time we have
9923 -- finished the rather complex transformation, the conversion looks
9924 -- redundant when it is not.
9926 if Operand_Typ = Universal_Fixed then
9927 Test_Redundant := False;
9929 -- If the operand is marked as Any_Fixed, then special processing is
9930 -- required. This is also a case where we suppress the test for a
9931 -- redundant conversion, since most certainly it is not redundant.
9933 elsif Operand_Typ = Any_Fixed then
9934 Test_Redundant := False;
9936 -- Mixed-mode operation involving a literal. Context must be a fixed
9937 -- type which is applied to the literal subsequently.
9939 if Is_Fixed_Point_Type (Typ) then
9940 Set_Etype (Operand, Universal_Real);
9942 elsif Is_Numeric_Type (Typ)
9943 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
9944 and then (Etype (Right_Opnd (Operand)) = Universal_Real
9946 Etype (Left_Opnd (Operand)) = Universal_Real)
9948 -- Return if expression is ambiguous
9950 if Unique_Fixed_Point_Type (N) = Any_Type then
9953 -- If nothing else, the available fixed type is Duration
9956 Set_Etype (Operand, Standard_Duration);
9959 -- Resolve the real operand with largest available precision
9961 if Etype (Right_Opnd (Operand)) = Universal_Real then
9962 Rop := New_Copy_Tree (Right_Opnd (Operand));
9964 Rop := New_Copy_Tree (Left_Opnd (Operand));
9967 Resolve (Rop, Universal_Real);
9969 -- If the operand is a literal (it could be a non-static and
9970 -- illegal exponentiation) check whether the use of Duration
9971 -- is potentially inaccurate.
9973 if Nkind (Rop) = N_Real_Literal
9974 and then Realval (Rop) /= Ureal_0
9975 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9978 ("??universal real operand can only "
9979 & "be interpreted as Duration!", Rop);
9981 ("\??precision will be lost in the conversion!", Rop);
9984 elsif Is_Numeric_Type (Typ)
9985 and then Nkind (Operand) in N_Op
9986 and then Unique_Fixed_Point_Type (N) /= Any_Type
9988 Set_Etype (Operand, Standard_Duration);
9991 Error_Msg_N ("invalid context for mixed mode operation", N);
9992 Set_Etype (Operand, Any_Type);
9999 -- In SPARK, a type conversion between array types should be restricted
10000 -- to types which have matching static bounds.
10002 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10003 -- operation if not needed.
10005 if Restriction_Check_Required (SPARK_05)
10006 and then Is_Array_Type (Target_Typ)
10007 and then Is_Array_Type (Operand_Typ)
10008 and then Operand_Typ /= Any_Composite -- or else Operand in error
10009 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10011 Check_SPARK_Restriction
10012 ("array types should have matching static bounds", N);
10015 -- In formal mode, the operand of an ancestor type conversion must be an
10016 -- object (not an expression).
10018 if Is_Tagged_Type (Target_Typ)
10019 and then not Is_Class_Wide_Type (Target_Typ)
10020 and then Is_Tagged_Type (Operand_Typ)
10021 and then not Is_Class_Wide_Type (Operand_Typ)
10022 and then Is_Ancestor (Target_Typ, Operand_Typ)
10023 and then not Is_SPARK_Object_Reference (Operand)
10025 Check_SPARK_Restriction ("object required", Operand);
10028 Analyze_Dimension (N);
10030 -- Note: we do the Eval_Type_Conversion call before applying the
10031 -- required checks for a subtype conversion. This is important, since
10032 -- both are prepared under certain circumstances to change the type
10033 -- conversion to a constraint error node, but in the case of
10034 -- Eval_Type_Conversion this may reflect an illegality in the static
10035 -- case, and we would miss the illegality (getting only a warning
10036 -- message), if we applied the type conversion checks first.
10038 Eval_Type_Conversion (N);
10040 -- Even when evaluation is not possible, we may be able to simplify the
10041 -- conversion or its expression. This needs to be done before applying
10042 -- checks, since otherwise the checks may use the original expression
10043 -- and defeat the simplifications. This is specifically the case for
10044 -- elimination of the floating-point Truncation attribute in
10045 -- float-to-int conversions.
10047 Simplify_Type_Conversion (N);
10049 -- If after evaluation we still have a type conversion, then we may need
10050 -- to apply checks required for a subtype conversion.
10052 -- Skip these type conversion checks if universal fixed operands
10053 -- operands involved, since range checks are handled separately for
10054 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10056 if Nkind (N) = N_Type_Conversion
10057 and then not Is_Generic_Type (Root_Type (Target_Typ))
10058 and then Target_Typ /= Universal_Fixed
10059 and then Operand_Typ /= Universal_Fixed
10061 Apply_Type_Conversion_Checks (N);
10064 -- Issue warning for conversion of simple object to its own type. We
10065 -- have to test the original nodes, since they may have been rewritten
10066 -- by various optimizations.
10068 Orig_N := Original_Node (N);
10070 -- Here we test for a redundant conversion if the warning mode is
10071 -- active (and was not locally reset), and we have a type conversion
10072 -- from source not appearing in a generic instance.
10075 and then Nkind (Orig_N) = N_Type_Conversion
10076 and then Comes_From_Source (Orig_N)
10077 and then not In_Instance
10079 Orig_N := Original_Node (Expression (Orig_N));
10080 Orig_T := Target_Typ;
10082 -- If the node is part of a larger expression, the Target_Type
10083 -- may not be the original type of the node if the context is a
10084 -- condition. Recover original type to see if conversion is needed.
10086 if Is_Boolean_Type (Orig_T)
10087 and then Nkind (Parent (N)) in N_Op
10089 Orig_T := Etype (Parent (N));
10092 -- If we have an entity name, then give the warning if the entity
10093 -- is the right type, or if it is a loop parameter covered by the
10094 -- original type (that's needed because loop parameters have an
10095 -- odd subtype coming from the bounds).
10097 if (Is_Entity_Name (Orig_N)
10099 (Etype (Entity (Orig_N)) = Orig_T
10101 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10102 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10104 -- If not an entity, then type of expression must match
10106 or else Etype (Orig_N) = Orig_T
10108 -- One more check, do not give warning if the analyzed conversion
10109 -- has an expression with non-static bounds, and the bounds of the
10110 -- target are static. This avoids junk warnings in cases where the
10111 -- conversion is necessary to establish staticness, for example in
10112 -- a case statement.
10114 if not Is_OK_Static_Subtype (Operand_Typ)
10115 and then Is_OK_Static_Subtype (Target_Typ)
10119 -- Finally, if this type conversion occurs in a context requiring
10120 -- a prefix, and the expression is a qualified expression then the
10121 -- type conversion is not redundant, since a qualified expression
10122 -- is not a prefix, whereas a type conversion is. For example, "X
10123 -- := T'(Funx(...)).Y;" is illegal because a selected component
10124 -- requires a prefix, but a type conversion makes it legal: "X :=
10125 -- T(T'(Funx(...))).Y;"
10127 -- In Ada 2012, a qualified expression is a name, so this idiom is
10128 -- no longer needed, but we still suppress the warning because it
10129 -- seems unfriendly for warnings to pop up when you switch to the
10130 -- newer language version.
10132 elsif Nkind (Orig_N) = N_Qualified_Expression
10133 and then Nkind_In (Parent (N), N_Attribute_Reference,
10134 N_Indexed_Component,
10135 N_Selected_Component,
10137 N_Explicit_Dereference)
10141 -- Never warn on conversion to Long_Long_Integer'Base since
10142 -- that is most likely an artifact of the extended overflow
10143 -- checking and comes from complex expanded code.
10145 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10148 -- Here we give the redundant conversion warning. If it is an
10149 -- entity, give the name of the entity in the message. If not,
10150 -- just mention the expression.
10152 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10155 if Is_Entity_Name (Orig_N) then
10156 Error_Msg_Node_2 := Orig_T;
10157 Error_Msg_NE -- CODEFIX
10158 ("??redundant conversion, & is of type &!",
10159 N, Entity (Orig_N));
10162 ("??redundant conversion, expression is of type&!",
10169 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10170 -- No need to perform any interface conversion if the type of the
10171 -- expression coincides with the target type.
10173 if Ada_Version >= Ada_2005
10174 and then Expander_Active
10175 and then Operand_Typ /= Target_Typ
10178 Opnd : Entity_Id := Operand_Typ;
10179 Target : Entity_Id := Target_Typ;
10182 if Is_Access_Type (Opnd) then
10183 Opnd := Designated_Type (Opnd);
10186 if Is_Access_Type (Target_Typ) then
10187 Target := Designated_Type (Target);
10190 if Opnd = Target then
10193 -- Conversion from interface type
10195 elsif Is_Interface (Opnd) then
10197 -- Ada 2005 (AI-217): Handle entities from limited views
10199 if From_Limited_With (Opnd) then
10200 Error_Msg_Qual_Level := 99;
10201 Error_Msg_NE -- CODEFIX
10202 ("missing WITH clause on package &", N,
10203 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10205 ("type conversions require visibility of the full view",
10208 elsif From_Limited_With (Target)
10210 (Is_Access_Type (Target_Typ)
10211 and then Present (Non_Limited_View (Etype (Target))))
10213 Error_Msg_Qual_Level := 99;
10214 Error_Msg_NE -- CODEFIX
10215 ("missing WITH clause on package &", N,
10216 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10218 ("type conversions require visibility of the full view",
10222 Expand_Interface_Conversion (N);
10225 -- Conversion to interface type
10227 elsif Is_Interface (Target) then
10231 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10232 Opnd := Etype (Opnd);
10235 if Is_Class_Wide_Type (Opnd)
10236 or else Interface_Present_In_Ancestor
10240 Expand_Interface_Conversion (N);
10242 Error_Msg_Name_1 := Chars (Etype (Target));
10243 Error_Msg_Name_2 := Chars (Opnd);
10245 ("wrong interface conversion (% is not a progenitor "
10252 -- Ada 2012: if target type has predicates, the result requires a
10253 -- predicate check. If the context is a call to another predicate
10254 -- check we must prevent infinite recursion.
10256 if Has_Predicates (Target_Typ) then
10257 if Nkind (Parent (N)) = N_Function_Call
10258 and then Present (Name (Parent (N)))
10259 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10261 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10266 Apply_Predicate_Check (N, Target_Typ);
10269 end Resolve_Type_Conversion;
10271 ----------------------
10272 -- Resolve_Unary_Op --
10273 ----------------------
10275 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
10276 B_Typ : constant Entity_Id := Base_Type (Typ);
10277 R : constant Node_Id := Right_Opnd (N);
10283 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
10284 Error_Msg_Name_1 := Chars (Typ);
10285 Check_SPARK_Restriction
10286 ("unary operator not defined for modular type%", N);
10289 -- Deal with intrinsic unary operators
10291 if Comes_From_Source (N)
10292 and then Ekind (Entity (N)) = E_Function
10293 and then Is_Imported (Entity (N))
10294 and then Is_Intrinsic_Subprogram (Entity (N))
10296 Resolve_Intrinsic_Unary_Operator (N, Typ);
10300 -- Deal with universal cases
10302 if Etype (R) = Universal_Integer
10304 Etype (R) = Universal_Real
10306 Check_For_Visible_Operator (N, B_Typ);
10309 Set_Etype (N, B_Typ);
10310 Resolve (R, B_Typ);
10312 -- Generate warning for expressions like abs (x mod 2)
10314 if Warn_On_Redundant_Constructs
10315 and then Nkind (N) = N_Op_Abs
10317 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
10319 if OK and then Hi >= Lo and then Lo >= 0 then
10320 Error_Msg_N -- CODEFIX
10321 ("?r?abs applied to known non-negative value has no effect", N);
10325 -- Deal with reference generation
10327 Check_Unset_Reference (R);
10328 Generate_Operator_Reference (N, B_Typ);
10329 Analyze_Dimension (N);
10332 -- Set overflow checking bit. Much cleverer code needed here eventually
10333 -- and perhaps the Resolve routines should be separated for the various
10334 -- arithmetic operations, since they will need different processing ???
10336 if Nkind (N) in N_Op then
10337 if not Overflow_Checks_Suppressed (Etype (N)) then
10338 Enable_Overflow_Check (N);
10342 -- Generate warning for expressions like -5 mod 3 for integers. No need
10343 -- to worry in the floating-point case, since parens do not affect the
10344 -- result so there is no point in giving in a warning.
10347 Norig : constant Node_Id := Original_Node (N);
10356 if Warn_On_Questionable_Missing_Parens
10357 and then Comes_From_Source (Norig)
10358 and then Is_Integer_Type (Typ)
10359 and then Nkind (Norig) = N_Op_Minus
10361 Rorig := Original_Node (Right_Opnd (Norig));
10363 -- We are looking for cases where the right operand is not
10364 -- parenthesized, and is a binary operator, multiply, divide, or
10365 -- mod. These are the cases where the grouping can affect results.
10367 if Paren_Count (Rorig) = 0
10368 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
10370 -- For mod, we always give the warning, since the value is
10371 -- affected by the parenthesization (e.g. (-5) mod 315 /=
10372 -- -(5 mod 315)). But for the other cases, the only concern is
10373 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
10374 -- overflows, but (-2) * 64 does not). So we try to give the
10375 -- message only when overflow is possible.
10377 if Nkind (Rorig) /= N_Op_Mod
10378 and then Compile_Time_Known_Value (R)
10380 Val := Expr_Value (R);
10382 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
10383 HB := Expr_Value (Type_High_Bound (Typ));
10385 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
10388 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
10389 LB := Expr_Value (Type_Low_Bound (Typ));
10391 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
10394 -- Note that the test below is deliberately excluding the
10395 -- largest negative number, since that is a potentially
10396 -- troublesome case (e.g. -2 * x, where the result is the
10397 -- largest negative integer has an overflow with 2 * x).
10399 if Val > LB and then Val <= HB then
10404 -- For the multiplication case, the only case we have to worry
10405 -- about is when (-a)*b is exactly the largest negative number
10406 -- so that -(a*b) can cause overflow. This can only happen if
10407 -- a is a power of 2, and more generally if any operand is a
10408 -- constant that is not a power of 2, then the parentheses
10409 -- cannot affect whether overflow occurs. We only bother to
10410 -- test the left most operand
10412 -- Loop looking at left operands for one that has known value
10415 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
10416 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
10417 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
10419 -- Operand value of 0 or 1 skips warning
10424 -- Otherwise check power of 2, if power of 2, warn, if
10425 -- anything else, skip warning.
10428 while Lval /= 2 loop
10429 if Lval mod 2 = 1 then
10440 -- Keep looking at left operands
10442 Opnd := Left_Opnd (Opnd);
10443 end loop Opnd_Loop;
10445 -- For rem or "/" we can only have a problematic situation
10446 -- if the divisor has a value of minus one or one. Otherwise
10447 -- overflow is impossible (divisor > 1) or we have a case of
10448 -- division by zero in any case.
10450 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
10451 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
10452 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
10457 -- If we fall through warning should be issued
10459 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
10462 ("??unary minus expression should be parenthesized here!", N);
10466 end Resolve_Unary_Op;
10468 ----------------------------------
10469 -- Resolve_Unchecked_Expression --
10470 ----------------------------------
10472 procedure Resolve_Unchecked_Expression
10477 Resolve (Expression (N), Typ, Suppress => All_Checks);
10478 Set_Etype (N, Typ);
10479 end Resolve_Unchecked_Expression;
10481 ---------------------------------------
10482 -- Resolve_Unchecked_Type_Conversion --
10483 ---------------------------------------
10485 procedure Resolve_Unchecked_Type_Conversion
10489 pragma Warnings (Off, Typ);
10491 Operand : constant Node_Id := Expression (N);
10492 Opnd_Type : constant Entity_Id := Etype (Operand);
10495 -- Resolve operand using its own type
10497 Resolve (Operand, Opnd_Type);
10498 Analyze_Dimension (N);
10499 Eval_Unchecked_Conversion (N);
10500 end Resolve_Unchecked_Type_Conversion;
10502 ------------------------------
10503 -- Rewrite_Operator_As_Call --
10504 ------------------------------
10506 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
10507 Loc : constant Source_Ptr := Sloc (N);
10508 Actuals : constant List_Id := New_List;
10512 if Nkind (N) in N_Binary_Op then
10513 Append (Left_Opnd (N), Actuals);
10516 Append (Right_Opnd (N), Actuals);
10519 Make_Function_Call (Sloc => Loc,
10520 Name => New_Occurrence_Of (Nam, Loc),
10521 Parameter_Associations => Actuals);
10523 Preserve_Comes_From_Source (New_N, N);
10524 Preserve_Comes_From_Source (Name (New_N), N);
10525 Rewrite (N, New_N);
10526 Set_Etype (N, Etype (Nam));
10527 end Rewrite_Operator_As_Call;
10529 ------------------------------
10530 -- Rewrite_Renamed_Operator --
10531 ------------------------------
10533 procedure Rewrite_Renamed_Operator
10538 Nam : constant Name_Id := Chars (Op);
10539 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
10543 -- Do not perform this transformation within a pre/postcondition,
10544 -- because the expression will be re-analyzed, and the transformation
10545 -- might affect the visibility of the operator, e.g. in an instance.
10547 if In_Assertion_Expr > 0 then
10551 -- Rewrite the operator node using the real operator, not its renaming.
10552 -- Exclude user-defined intrinsic operations of the same name, which are
10553 -- treated separately and rewritten as calls.
10555 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
10556 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
10557 Set_Chars (Op_Node, Nam);
10558 Set_Etype (Op_Node, Etype (N));
10559 Set_Entity (Op_Node, Op);
10560 Set_Right_Opnd (Op_Node, Right_Opnd (N));
10562 -- Indicate that both the original entity and its renaming are
10563 -- referenced at this point.
10565 Generate_Reference (Entity (N), N);
10566 Generate_Reference (Op, N);
10569 Set_Left_Opnd (Op_Node, Left_Opnd (N));
10572 Rewrite (N, Op_Node);
10574 -- If the context type is private, add the appropriate conversions so
10575 -- that the operator is applied to the full view. This is done in the
10576 -- routines that resolve intrinsic operators.
10578 if Is_Intrinsic_Subprogram (Op)
10579 and then Is_Private_Type (Typ)
10582 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
10583 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
10584 Resolve_Intrinsic_Operator (N, Typ);
10586 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
10587 Resolve_Intrinsic_Unary_Operator (N, Typ);
10594 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
10596 -- Operator renames a user-defined operator of the same name. Use the
10597 -- original operator in the node, which is the one Gigi knows about.
10599 Set_Entity (N, Op);
10600 Set_Is_Overloaded (N, False);
10602 end Rewrite_Renamed_Operator;
10604 -----------------------
10605 -- Set_Slice_Subtype --
10606 -----------------------
10608 -- Build an implicit subtype declaration to represent the type delivered by
10609 -- the slice. This is an abbreviated version of an array subtype. We define
10610 -- an index subtype for the slice, using either the subtype name or the
10611 -- discrete range of the slice. To be consistent with index usage elsewhere
10612 -- we create a list header to hold the single index. This list is not
10613 -- otherwise attached to the syntax tree.
10615 procedure Set_Slice_Subtype (N : Node_Id) is
10616 Loc : constant Source_Ptr := Sloc (N);
10617 Index_List : constant List_Id := New_List;
10619 Index_Subtype : Entity_Id;
10620 Index_Type : Entity_Id;
10621 Slice_Subtype : Entity_Id;
10622 Drange : constant Node_Id := Discrete_Range (N);
10625 Index_Type := Base_Type (Etype (Drange));
10627 if Is_Entity_Name (Drange) then
10628 Index_Subtype := Entity (Drange);
10631 -- We force the evaluation of a range. This is definitely needed in
10632 -- the renamed case, and seems safer to do unconditionally. Note in
10633 -- any case that since we will create and insert an Itype referring
10634 -- to this range, we must make sure any side effect removal actions
10635 -- are inserted before the Itype definition.
10637 if Nkind (Drange) = N_Range then
10638 Force_Evaluation (Low_Bound (Drange));
10639 Force_Evaluation (High_Bound (Drange));
10641 -- If the discrete range is given by a subtype indication, the
10642 -- type of the slice is the base of the subtype mark.
10644 elsif Nkind (Drange) = N_Subtype_Indication then
10646 R : constant Node_Id := Range_Expression (Constraint (Drange));
10648 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
10649 Force_Evaluation (Low_Bound (R));
10650 Force_Evaluation (High_Bound (R));
10654 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
10656 -- Take a new copy of Drange (where bounds have been rewritten to
10657 -- reference side-effect-free names). Using a separate tree ensures
10658 -- that further expansion (e.g. while rewriting a slice assignment
10659 -- into a FOR loop) does not attempt to remove side effects on the
10660 -- bounds again (which would cause the bounds in the index subtype
10661 -- definition to refer to temporaries before they are defined) (the
10662 -- reason is that some names are considered side effect free here
10663 -- for the subtype, but not in the context of a loop iteration
10666 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
10667 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
10668 Set_Etype (Index_Subtype, Index_Type);
10669 Set_Size_Info (Index_Subtype, Index_Type);
10670 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
10673 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
10675 Index := New_Occurrence_Of (Index_Subtype, Loc);
10676 Set_Etype (Index, Index_Subtype);
10677 Append (Index, Index_List);
10679 Set_First_Index (Slice_Subtype, Index);
10680 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
10681 Set_Is_Constrained (Slice_Subtype, True);
10683 Check_Compile_Time_Size (Slice_Subtype);
10685 -- The Etype of the existing Slice node is reset to this slice subtype.
10686 -- Its bounds are obtained from its first index.
10688 Set_Etype (N, Slice_Subtype);
10690 -- For packed slice subtypes, freeze immediately (except in the case of
10691 -- being in a "spec expression" where we never freeze when we first see
10692 -- the expression).
10694 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
10695 Freeze_Itype (Slice_Subtype, N);
10697 -- For all other cases insert an itype reference in the slice's actions
10698 -- so that the itype is frozen at the proper place in the tree (i.e. at
10699 -- the point where actions for the slice are analyzed). Note that this
10700 -- is different from freezing the itype immediately, which might be
10701 -- premature (e.g. if the slice is within a transient scope). This needs
10702 -- to be done only if expansion is enabled.
10704 elsif Expander_Active then
10705 Ensure_Defined (Typ => Slice_Subtype, N => N);
10707 end Set_Slice_Subtype;
10709 --------------------------------
10710 -- Set_String_Literal_Subtype --
10711 --------------------------------
10713 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
10714 Loc : constant Source_Ptr := Sloc (N);
10715 Low_Bound : constant Node_Id :=
10716 Type_Low_Bound (Etype (First_Index (Typ)));
10717 Subtype_Id : Entity_Id;
10720 if Nkind (N) /= N_String_Literal then
10724 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
10725 Set_String_Literal_Length (Subtype_Id, UI_From_Int
10726 (String_Length (Strval (N))));
10727 Set_Etype (Subtype_Id, Base_Type (Typ));
10728 Set_Is_Constrained (Subtype_Id);
10729 Set_Etype (N, Subtype_Id);
10731 -- The low bound is set from the low bound of the corresponding index
10732 -- type. Note that we do not store the high bound in the string literal
10733 -- subtype, but it can be deduced if necessary from the length and the
10736 if Is_OK_Static_Expression (Low_Bound) then
10737 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
10739 -- If the lower bound is not static we create a range for the string
10740 -- literal, using the index type and the known length of the literal.
10741 -- The index type is not necessarily Positive, so the upper bound is
10742 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
10746 Index_List : constant List_Id := New_List;
10747 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
10748 High_Bound : constant Node_Id :=
10749 Make_Attribute_Reference (Loc,
10750 Attribute_Name => Name_Val,
10752 New_Occurrence_Of (Index_Type, Loc),
10753 Expressions => New_List (
10756 Make_Attribute_Reference (Loc,
10757 Attribute_Name => Name_Pos,
10759 New_Occurrence_Of (Index_Type, Loc),
10761 New_List (New_Copy_Tree (Low_Bound))),
10763 Make_Integer_Literal (Loc,
10764 String_Length (Strval (N)) - 1))));
10766 Array_Subtype : Entity_Id;
10769 Index_Subtype : Entity_Id;
10772 if Is_Integer_Type (Index_Type) then
10773 Set_String_Literal_Low_Bound
10774 (Subtype_Id, Make_Integer_Literal (Loc, 1));
10777 -- If the index type is an enumeration type, build bounds
10778 -- expression with attributes.
10780 Set_String_Literal_Low_Bound
10782 Make_Attribute_Reference (Loc,
10783 Attribute_Name => Name_First,
10785 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
10786 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
10789 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
10791 -- Build bona fide subtype for the string, and wrap it in an
10792 -- unchecked conversion, because the backend expects the
10793 -- String_Literal_Subtype to have a static lower bound.
10796 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
10797 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
10798 Set_Scalar_Range (Index_Subtype, Drange);
10799 Set_Parent (Drange, N);
10800 Analyze_And_Resolve (Drange, Index_Type);
10802 -- In the context, the Index_Type may already have a constraint,
10803 -- so use common base type on string subtype. The base type may
10804 -- be used when generating attributes of the string, for example
10805 -- in the context of a slice assignment.
10807 Set_Etype (Index_Subtype, Base_Type (Index_Type));
10808 Set_Size_Info (Index_Subtype, Index_Type);
10809 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
10811 Array_Subtype := Create_Itype (E_Array_Subtype, N);
10813 Index := New_Occurrence_Of (Index_Subtype, Loc);
10814 Set_Etype (Index, Index_Subtype);
10815 Append (Index, Index_List);
10817 Set_First_Index (Array_Subtype, Index);
10818 Set_Etype (Array_Subtype, Base_Type (Typ));
10819 Set_Is_Constrained (Array_Subtype, True);
10822 Make_Unchecked_Type_Conversion (Loc,
10823 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
10824 Expression => Relocate_Node (N)));
10825 Set_Etype (N, Array_Subtype);
10828 end Set_String_Literal_Subtype;
10830 ------------------------------
10831 -- Simplify_Type_Conversion --
10832 ------------------------------
10834 procedure Simplify_Type_Conversion (N : Node_Id) is
10836 if Nkind (N) = N_Type_Conversion then
10838 Operand : constant Node_Id := Expression (N);
10839 Target_Typ : constant Entity_Id := Etype (N);
10840 Opnd_Typ : constant Entity_Id := Etype (Operand);
10843 if Is_Floating_Point_Type (Opnd_Typ)
10845 (Is_Integer_Type (Target_Typ)
10846 or else (Is_Fixed_Point_Type (Target_Typ)
10847 and then Conversion_OK (N)))
10848 and then Nkind (Operand) = N_Attribute_Reference
10849 and then Attribute_Name (Operand) = Name_Truncation
10851 -- Special processing required if the conversion is the expression
10852 -- of a Truncation attribute reference. In this case we replace:
10854 -- ityp (ftyp'Truncation (x))
10860 -- with the Float_Truncate flag set, which is more efficient.
10864 Relocate_Node (First (Expressions (Operand))));
10865 Set_Float_Truncate (N, True);
10869 end Simplify_Type_Conversion;
10871 -----------------------------
10872 -- Unique_Fixed_Point_Type --
10873 -----------------------------
10875 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
10876 T1 : Entity_Id := Empty;
10881 procedure Fixed_Point_Error;
10882 -- Give error messages for true ambiguity. Messages are posted on node
10883 -- N, and entities T1, T2 are the possible interpretations.
10885 -----------------------
10886 -- Fixed_Point_Error --
10887 -----------------------
10889 procedure Fixed_Point_Error is
10891 Error_Msg_N ("ambiguous universal_fixed_expression", N);
10892 Error_Msg_NE ("\\possible interpretation as}", N, T1);
10893 Error_Msg_NE ("\\possible interpretation as}", N, T2);
10894 end Fixed_Point_Error;
10896 -- Start of processing for Unique_Fixed_Point_Type
10899 -- The operations on Duration are visible, so Duration is always a
10900 -- possible interpretation.
10902 T1 := Standard_Duration;
10904 -- Look for fixed-point types in enclosing scopes
10906 Scop := Current_Scope;
10907 while Scop /= Standard_Standard loop
10908 T2 := First_Entity (Scop);
10909 while Present (T2) loop
10910 if Is_Fixed_Point_Type (T2)
10911 and then Current_Entity (T2) = T2
10912 and then Scope (Base_Type (T2)) = Scop
10914 if Present (T1) then
10925 Scop := Scope (Scop);
10928 -- Look for visible fixed type declarations in the context
10930 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
10931 while Present (Item) loop
10932 if Nkind (Item) = N_With_Clause then
10933 Scop := Entity (Name (Item));
10934 T2 := First_Entity (Scop);
10935 while Present (T2) loop
10936 if Is_Fixed_Point_Type (T2)
10937 and then Scope (Base_Type (T2)) = Scop
10938 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
10940 if Present (T1) then
10955 if Nkind (N) = N_Real_Literal then
10957 ("??real literal interpreted as }!", N, T1);
10960 ("??universal_fixed expression interpreted as }!", N, T1);
10964 end Unique_Fixed_Point_Type;
10966 ----------------------
10967 -- Valid_Conversion --
10968 ----------------------
10970 function Valid_Conversion
10972 Target : Entity_Id;
10974 Report_Errs : Boolean := True) return Boolean
10976 Target_Type : constant Entity_Id := Base_Type (Target);
10977 Opnd_Type : Entity_Id := Etype (Operand);
10978 Inc_Ancestor : Entity_Id;
10980 function Conversion_Check
10982 Msg : String) return Boolean;
10983 -- Little routine to post Msg if Valid is False, returns Valid value
10985 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
10986 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
10988 procedure Conversion_Error_NE
10990 N : Node_Or_Entity_Id;
10991 E : Node_Or_Entity_Id);
10992 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
10994 function Valid_Tagged_Conversion
10995 (Target_Type : Entity_Id;
10996 Opnd_Type : Entity_Id) return Boolean;
10997 -- Specifically test for validity of tagged conversions
10999 function Valid_Array_Conversion return Boolean;
11000 -- Check index and component conformance, and accessibility levels if
11001 -- the component types are anonymous access types (Ada 2005).
11003 ----------------------
11004 -- Conversion_Check --
11005 ----------------------
11007 function Conversion_Check
11009 Msg : String) return Boolean
11014 -- A generic unit has already been analyzed and we have verified
11015 -- that a particular conversion is OK in that context. Since the
11016 -- instance is reanalyzed without relying on the relationships
11017 -- established during the analysis of the generic, it is possible
11018 -- to end up with inconsistent views of private types. Do not emit
11019 -- the error message in such cases. The rest of the machinery in
11020 -- Valid_Conversion still ensures the proper compatibility of
11021 -- target and operand types.
11023 and then not In_Instance
11025 Conversion_Error_N (Msg, Operand);
11029 end Conversion_Check;
11031 ------------------------
11032 -- Conversion_Error_N --
11033 ------------------------
11035 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11037 if Report_Errs then
11038 Error_Msg_N (Msg, N);
11040 end Conversion_Error_N;
11042 -------------------------
11043 -- Conversion_Error_NE --
11044 -------------------------
11046 procedure Conversion_Error_NE
11048 N : Node_Or_Entity_Id;
11049 E : Node_Or_Entity_Id)
11052 if Report_Errs then
11053 Error_Msg_NE (Msg, N, E);
11055 end Conversion_Error_NE;
11057 ----------------------------
11058 -- Valid_Array_Conversion --
11059 ----------------------------
11061 function Valid_Array_Conversion return Boolean
11063 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11064 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11066 Opnd_Index : Node_Id;
11067 Opnd_Index_Type : Entity_Id;
11069 Target_Comp_Type : constant Entity_Id :=
11070 Component_Type (Target_Type);
11071 Target_Comp_Base : constant Entity_Id :=
11072 Base_Type (Target_Comp_Type);
11074 Target_Index : Node_Id;
11075 Target_Index_Type : Entity_Id;
11078 -- Error if wrong number of dimensions
11081 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11084 ("incompatible number of dimensions for conversion", Operand);
11087 -- Number of dimensions matches
11090 -- Loop through indexes of the two arrays
11092 Target_Index := First_Index (Target_Type);
11093 Opnd_Index := First_Index (Opnd_Type);
11094 while Present (Target_Index) and then Present (Opnd_Index) loop
11095 Target_Index_Type := Etype (Target_Index);
11096 Opnd_Index_Type := Etype (Opnd_Index);
11098 -- Error if index types are incompatible
11100 if not (Is_Integer_Type (Target_Index_Type)
11101 and then Is_Integer_Type (Opnd_Index_Type))
11102 and then (Root_Type (Target_Index_Type)
11103 /= Root_Type (Opnd_Index_Type))
11106 ("incompatible index types for array conversion",
11111 Next_Index (Target_Index);
11112 Next_Index (Opnd_Index);
11115 -- If component types have same base type, all set
11117 if Target_Comp_Base = Opnd_Comp_Base then
11120 -- Here if base types of components are not the same. The only
11121 -- time this is allowed is if we have anonymous access types.
11123 -- The conversion of arrays of anonymous access types can lead
11124 -- to dangling pointers. AI-392 formalizes the accessibility
11125 -- checks that must be applied to such conversions to prevent
11126 -- out-of-scope references.
11129 (Target_Comp_Base, E_Anonymous_Access_Type,
11130 E_Anonymous_Access_Subprogram_Type)
11131 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11133 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11135 if Type_Access_Level (Target_Type) <
11136 Deepest_Type_Access_Level (Opnd_Type)
11138 if In_Instance_Body then
11139 Error_Msg_Warn := SPARK_Mode /= On;
11141 ("source array type has deeper accessibility "
11142 & "level than target<<", Operand);
11143 Conversion_Error_N ("\Program_Error [<<", Operand);
11145 Make_Raise_Program_Error (Sloc (N),
11146 Reason => PE_Accessibility_Check_Failed));
11147 Set_Etype (N, Target_Type);
11150 -- Conversion not allowed because of accessibility levels
11154 ("source array type has deeper accessibility "
11155 & "level than target", Operand);
11163 -- All other cases where component base types do not match
11167 ("incompatible component types for array conversion",
11172 -- Check that component subtypes statically match. For numeric
11173 -- types this means that both must be either constrained or
11174 -- unconstrained. For enumeration types the bounds must match.
11175 -- All of this is checked in Subtypes_Statically_Match.
11177 if not Subtypes_Statically_Match
11178 (Target_Comp_Type, Opnd_Comp_Type)
11181 ("component subtypes must statically match", Operand);
11187 end Valid_Array_Conversion;
11189 -----------------------------
11190 -- Valid_Tagged_Conversion --
11191 -----------------------------
11193 function Valid_Tagged_Conversion
11194 (Target_Type : Entity_Id;
11195 Opnd_Type : Entity_Id) return Boolean
11198 -- Upward conversions are allowed (RM 4.6(22))
11200 if Covers (Target_Type, Opnd_Type)
11201 or else Is_Ancestor (Target_Type, Opnd_Type)
11205 -- Downward conversion are allowed if the operand is class-wide
11208 elsif Is_Class_Wide_Type (Opnd_Type)
11209 and then Covers (Opnd_Type, Target_Type)
11213 elsif Covers (Opnd_Type, Target_Type)
11214 or else Is_Ancestor (Opnd_Type, Target_Type)
11217 Conversion_Check (False,
11218 "downward conversion of tagged objects not allowed");
11220 -- Ada 2005 (AI-251): The conversion to/from interface types is
11223 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
11226 -- If the operand is a class-wide type obtained through a limited_
11227 -- with clause, and the context includes the non-limited view, use
11228 -- it to determine whether the conversion is legal.
11230 elsif Is_Class_Wide_Type (Opnd_Type)
11231 and then From_Limited_With (Opnd_Type)
11232 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11233 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11237 elsif Is_Access_Type (Opnd_Type)
11238 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11243 Conversion_Error_NE
11244 ("invalid tagged conversion, not compatible with}",
11245 N, First_Subtype (Opnd_Type));
11248 end Valid_Tagged_Conversion;
11250 -- Start of processing for Valid_Conversion
11253 Check_Parameterless_Call (Operand);
11255 if Is_Overloaded (Operand) then
11265 -- Remove procedure calls, which syntactically cannot appear in
11266 -- this context, but which cannot be removed by type checking,
11267 -- because the context does not impose a type.
11269 -- When compiling for VMS, spurious ambiguities can be produced
11270 -- when arithmetic operations have a literal operand and return
11271 -- System.Address or a descendant of it. These ambiguities are
11272 -- otherwise resolved by the context, but for conversions there
11273 -- is no context type and the removal of the spurious operations
11274 -- must be done explicitly here.
11276 -- The node may be labelled overloaded, but still contain only one
11277 -- interpretation because others were discarded earlier. If this
11278 -- is the case, retain the single interpretation if legal.
11280 Get_First_Interp (Operand, I, It);
11281 Opnd_Type := It.Typ;
11282 Get_Next_Interp (I, It);
11284 if Present (It.Typ)
11285 and then Opnd_Type /= Standard_Void_Type
11287 -- More than one candidate interpretation is available
11289 Get_First_Interp (Operand, I, It);
11290 while Present (It.Typ) loop
11291 if It.Typ = Standard_Void_Type then
11295 if Present (System_Aux_Id)
11296 and then Is_Descendent_Of_Address (It.Typ)
11301 Get_Next_Interp (I, It);
11305 Get_First_Interp (Operand, I, It);
11309 if No (It.Typ) then
11310 Conversion_Error_N ("illegal operand in conversion", Operand);
11314 Get_Next_Interp (I, It);
11316 if Present (It.Typ) then
11319 It1 := Disambiguate (Operand, I1, I, Any_Type);
11321 if It1 = No_Interp then
11323 ("ambiguous operand in conversion", Operand);
11325 -- If the interpretation involves a standard operator, use
11326 -- the location of the type, which may be user-defined.
11328 if Sloc (It.Nam) = Standard_Location then
11329 Error_Msg_Sloc := Sloc (It.Typ);
11331 Error_Msg_Sloc := Sloc (It.Nam);
11334 Conversion_Error_N -- CODEFIX
11335 ("\\possible interpretation#!", Operand);
11337 if Sloc (N1) = Standard_Location then
11338 Error_Msg_Sloc := Sloc (T1);
11340 Error_Msg_Sloc := Sloc (N1);
11343 Conversion_Error_N -- CODEFIX
11344 ("\\possible interpretation#!", Operand);
11350 Set_Etype (Operand, It1.Typ);
11351 Opnd_Type := It1.Typ;
11355 -- Deal with conversion of integer type to address if the pragma
11356 -- Allow_Integer_Address is in effect. We convert the conversion to
11357 -- an unchecked conversion in this case and we are all done.
11359 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
11360 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
11361 Analyze_And_Resolve (N, Target_Type);
11365 -- If we are within a child unit, check whether the type of the
11366 -- expression has an ancestor in a parent unit, in which case it
11367 -- belongs to its derivation class even if the ancestor is private.
11368 -- See RM 7.3.1 (5.2/3).
11370 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
11374 if Is_Numeric_Type (Target_Type) then
11376 -- A universal fixed expression can be converted to any numeric type
11378 if Opnd_Type = Universal_Fixed then
11381 -- Also no need to check when in an instance or inlined body, because
11382 -- the legality has been established when the template was analyzed.
11383 -- Furthermore, numeric conversions may occur where only a private
11384 -- view of the operand type is visible at the instantiation point.
11385 -- This results in a spurious error if we check that the operand type
11386 -- is a numeric type.
11388 -- Note: in a previous version of this unit, the following tests were
11389 -- applied only for generated code (Comes_From_Source set to False),
11390 -- but in fact the test is required for source code as well, since
11391 -- this situation can arise in source code.
11393 elsif In_Instance or else In_Inlined_Body then
11396 -- Otherwise we need the conversion check
11399 return Conversion_Check
11400 (Is_Numeric_Type (Opnd_Type)
11402 (Present (Inc_Ancestor)
11403 and then Is_Numeric_Type (Inc_Ancestor)),
11404 "illegal operand for numeric conversion");
11409 elsif Is_Array_Type (Target_Type) then
11410 if not Is_Array_Type (Opnd_Type)
11411 or else Opnd_Type = Any_Composite
11412 or else Opnd_Type = Any_String
11415 ("illegal operand for array conversion", Operand);
11419 return Valid_Array_Conversion;
11422 -- Ada 2005 (AI-251): Anonymous access types where target references an
11425 elsif Ekind_In (Target_Type, E_General_Access_Type,
11426 E_Anonymous_Access_Type)
11427 and then Is_Interface (Directly_Designated_Type (Target_Type))
11429 -- Check the static accessibility rule of 4.6(17). Note that the
11430 -- check is not enforced when within an instance body, since the
11431 -- RM requires such cases to be caught at run time.
11433 -- If the operand is a rewriting of an allocator no check is needed
11434 -- because there are no accessibility issues.
11436 if Nkind (Original_Node (N)) = N_Allocator then
11439 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
11440 if Type_Access_Level (Opnd_Type) >
11441 Deepest_Type_Access_Level (Target_Type)
11443 -- In an instance, this is a run-time check, but one we know
11444 -- will fail, so generate an appropriate warning. The raise
11445 -- will be generated by Expand_N_Type_Conversion.
11447 if In_Instance_Body then
11448 Error_Msg_Warn := SPARK_Mode /= On;
11450 ("cannot convert local pointer to non-local access type<<",
11452 Conversion_Error_N ("\Program_Error [<<", Operand);
11456 ("cannot convert local pointer to non-local access type",
11461 -- Special accessibility checks are needed in the case of access
11462 -- discriminants declared for a limited type.
11464 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
11465 and then not Is_Local_Anonymous_Access (Opnd_Type)
11467 -- When the operand is a selected access discriminant the check
11468 -- needs to be made against the level of the object denoted by
11469 -- the prefix of the selected name (Object_Access_Level handles
11470 -- checking the prefix of the operand for this case).
11472 if Nkind (Operand) = N_Selected_Component
11473 and then Object_Access_Level (Operand) >
11474 Deepest_Type_Access_Level (Target_Type)
11476 -- In an instance, this is a run-time check, but one we know
11477 -- will fail, so generate an appropriate warning. The raise
11478 -- will be generated by Expand_N_Type_Conversion.
11480 if In_Instance_Body then
11481 Error_Msg_Warn := SPARK_Mode /= On;
11483 ("cannot convert access discriminant to non-local "
11484 & "access type<<", Operand);
11485 Conversion_Error_N ("\Program_Error [<<", Operand);
11487 -- Real error if not in instance body
11491 ("cannot convert access discriminant to non-local "
11492 & "access type", Operand);
11497 -- The case of a reference to an access discriminant from
11498 -- within a limited type declaration (which will appear as
11499 -- a discriminal) is always illegal because the level of the
11500 -- discriminant is considered to be deeper than any (nameable)
11503 if Is_Entity_Name (Operand)
11504 and then not Is_Local_Anonymous_Access (Opnd_Type)
11506 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
11507 and then Present (Discriminal_Link (Entity (Operand)))
11510 ("discriminant has deeper accessibility level than target",
11519 -- General and anonymous access types
11521 elsif Ekind_In (Target_Type, E_General_Access_Type,
11522 E_Anonymous_Access_Type)
11525 (Is_Access_Type (Opnd_Type)
11527 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
11528 E_Access_Protected_Subprogram_Type),
11529 "must be an access-to-object type")
11531 if Is_Access_Constant (Opnd_Type)
11532 and then not Is_Access_Constant (Target_Type)
11535 ("access-to-constant operand type not allowed", Operand);
11539 -- Check the static accessibility rule of 4.6(17). Note that the
11540 -- check is not enforced when within an instance body, since the RM
11541 -- requires such cases to be caught at run time.
11543 if Ekind (Target_Type) /= E_Anonymous_Access_Type
11544 or else Is_Local_Anonymous_Access (Target_Type)
11545 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
11546 N_Object_Declaration
11548 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
11549 -- conversions from an anonymous access type to a named general
11550 -- access type. Such conversions are not allowed in the case of
11551 -- access parameters and stand-alone objects of an anonymous
11552 -- access type. The implicit conversion case is recognized by
11553 -- testing that Comes_From_Source is False and that it's been
11554 -- rewritten. The Comes_From_Source test isn't sufficient because
11555 -- nodes in inlined calls to predefined library routines can have
11556 -- Comes_From_Source set to False. (Is there a better way to test
11557 -- for implicit conversions???)
11559 if Ada_Version >= Ada_2012
11560 and then not Comes_From_Source (N)
11561 and then N /= Original_Node (N)
11562 and then Ekind (Target_Type) = E_General_Access_Type
11563 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
11565 if Is_Itype (Opnd_Type) then
11567 -- Implicit conversions aren't allowed for objects of an
11568 -- anonymous access type, since such objects have nonstatic
11569 -- levels in Ada 2012.
11571 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
11572 N_Object_Declaration
11575 ("implicit conversion of stand-alone anonymous "
11576 & "access object not allowed", Operand);
11579 -- Implicit conversions aren't allowed for anonymous access
11580 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
11581 -- is done to exclude anonymous access results.
11583 elsif not Is_Local_Anonymous_Access (Opnd_Type)
11584 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
11585 N_Function_Specification,
11586 N_Procedure_Specification)
11589 ("implicit conversion of anonymous access formal "
11590 & "not allowed", Operand);
11593 -- This is a case where there's an enclosing object whose
11594 -- to which the "statically deeper than" relationship does
11595 -- not apply (such as an access discriminant selected from
11596 -- a dereference of an access parameter).
11598 elsif Object_Access_Level (Operand)
11599 = Scope_Depth (Standard_Standard)
11602 ("implicit conversion of anonymous access value "
11603 & "not allowed", Operand);
11606 -- In other cases, the level of the operand's type must be
11607 -- statically less deep than that of the target type, else
11608 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
11610 elsif Type_Access_Level (Opnd_Type) >
11611 Deepest_Type_Access_Level (Target_Type)
11614 ("implicit conversion of anonymous access value "
11615 & "violates accessibility", Operand);
11620 elsif Type_Access_Level (Opnd_Type) >
11621 Deepest_Type_Access_Level (Target_Type)
11623 -- In an instance, this is a run-time check, but one we know
11624 -- will fail, so generate an appropriate warning. The raise
11625 -- will be generated by Expand_N_Type_Conversion.
11627 if In_Instance_Body then
11628 Error_Msg_Warn := SPARK_Mode /= On;
11630 ("cannot convert local pointer to non-local access type<<",
11632 Conversion_Error_N ("\Program_Error [<<", Operand);
11634 -- If not in an instance body, this is a real error
11637 -- Avoid generation of spurious error message
11639 if not Error_Posted (N) then
11641 ("cannot convert local pointer to non-local access type",
11648 -- Special accessibility checks are needed in the case of access
11649 -- discriminants declared for a limited type.
11651 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
11652 and then not Is_Local_Anonymous_Access (Opnd_Type)
11654 -- When the operand is a selected access discriminant the check
11655 -- needs to be made against the level of the object denoted by
11656 -- the prefix of the selected name (Object_Access_Level handles
11657 -- checking the prefix of the operand for this case).
11659 if Nkind (Operand) = N_Selected_Component
11660 and then Object_Access_Level (Operand) >
11661 Deepest_Type_Access_Level (Target_Type)
11663 -- In an instance, this is a run-time check, but one we know
11664 -- will fail, so generate an appropriate warning. The raise
11665 -- will be generated by Expand_N_Type_Conversion.
11667 if In_Instance_Body then
11668 Error_Msg_Warn := SPARK_Mode /= On;
11670 ("cannot convert access discriminant to non-local "
11671 & "access type<<", Operand);
11672 Conversion_Error_N ("\Program_Error [<<", Operand);
11674 -- If not in an instance body, this is a real error
11678 ("cannot convert access discriminant to non-local "
11679 & "access type", Operand);
11684 -- The case of a reference to an access discriminant from
11685 -- within a limited type declaration (which will appear as
11686 -- a discriminal) is always illegal because the level of the
11687 -- discriminant is considered to be deeper than any (nameable)
11690 if Is_Entity_Name (Operand)
11692 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
11693 and then Present (Discriminal_Link (Entity (Operand)))
11696 ("discriminant has deeper accessibility level than target",
11703 -- In the presence of limited_with clauses we have to use non-limited
11704 -- views, if available.
11706 Check_Limited : declare
11707 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
11708 -- Helper function to handle limited views
11710 --------------------------
11711 -- Full_Designated_Type --
11712 --------------------------
11714 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
11715 Desig : constant Entity_Id := Designated_Type (T);
11718 -- Handle the limited view of a type
11720 if Is_Incomplete_Type (Desig)
11721 and then From_Limited_With (Desig)
11722 and then Present (Non_Limited_View (Desig))
11724 return Available_View (Desig);
11728 end Full_Designated_Type;
11730 -- Local Declarations
11732 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
11733 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
11735 Same_Base : constant Boolean :=
11736 Base_Type (Target) = Base_Type (Opnd);
11738 -- Start of processing for Check_Limited
11741 if Is_Tagged_Type (Target) then
11742 return Valid_Tagged_Conversion (Target, Opnd);
11745 if not Same_Base then
11746 Conversion_Error_NE
11747 ("target designated type not compatible with }",
11748 N, Base_Type (Opnd));
11751 -- Ada 2005 AI-384: legality rule is symmetric in both
11752 -- designated types. The conversion is legal (with possible
11753 -- constraint check) if either designated type is
11756 elsif Subtypes_Statically_Match (Target, Opnd)
11758 (Has_Discriminants (Target)
11760 (not Is_Constrained (Opnd)
11761 or else not Is_Constrained (Target)))
11763 -- Special case, if Value_Size has been used to make the
11764 -- sizes different, the conversion is not allowed even
11765 -- though the subtypes statically match.
11767 if Known_Static_RM_Size (Target)
11768 and then Known_Static_RM_Size (Opnd)
11769 and then RM_Size (Target) /= RM_Size (Opnd)
11771 Conversion_Error_NE
11772 ("target designated subtype not compatible with }",
11774 Conversion_Error_NE
11775 ("\because sizes of the two designated subtypes differ",
11779 -- Normal case where conversion is allowed
11787 ("target designated subtype not compatible with }",
11794 -- Access to subprogram types. If the operand is an access parameter,
11795 -- the type has a deeper accessibility that any master, and cannot be
11796 -- assigned. We must make an exception if the conversion is part of an
11797 -- assignment and the target is the return object of an extended return
11798 -- statement, because in that case the accessibility check takes place
11799 -- after the return.
11801 elsif Is_Access_Subprogram_Type (Target_Type)
11803 -- Note: this test of Opnd_Type is there to prevent entering this
11804 -- branch in the case of a remote access to subprogram type, which
11805 -- is internally represented as an E_Record_Type.
11807 and then Is_Access_Type (Opnd_Type)
11809 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
11810 and then Is_Entity_Name (Operand)
11811 and then Ekind (Entity (Operand)) = E_In_Parameter
11813 (Nkind (Parent (N)) /= N_Assignment_Statement
11814 or else not Is_Entity_Name (Name (Parent (N)))
11815 or else not Is_Return_Object (Entity (Name (Parent (N)))))
11818 ("illegal attempt to store anonymous access to subprogram",
11821 ("\value has deeper accessibility than any master "
11822 & "(RM 3.10.2 (13))",
11826 ("\use named access type for& instead of access parameter",
11827 Operand, Entity (Operand));
11830 -- Check that the designated types are subtype conformant
11832 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
11833 Old_Id => Designated_Type (Opnd_Type),
11836 -- Check the static accessibility rule of 4.6(20)
11838 if Type_Access_Level (Opnd_Type) >
11839 Deepest_Type_Access_Level (Target_Type)
11842 ("operand type has deeper accessibility level than target",
11845 -- Check that if the operand type is declared in a generic body,
11846 -- then the target type must be declared within that same body
11847 -- (enforces last sentence of 4.6(20)).
11849 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
11851 O_Gen : constant Node_Id :=
11852 Enclosing_Generic_Body (Opnd_Type);
11857 T_Gen := Enclosing_Generic_Body (Target_Type);
11858 while Present (T_Gen) and then T_Gen /= O_Gen loop
11859 T_Gen := Enclosing_Generic_Body (T_Gen);
11862 if T_Gen /= O_Gen then
11864 ("target type must be declared in same generic body "
11865 & "as operand type", N);
11872 -- Remote access to subprogram types
11874 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
11875 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
11877 -- It is valid to convert from one RAS type to another provided
11878 -- that their specification statically match.
11880 -- Note: at this point, remote access to subprogram types have been
11881 -- expanded to their E_Record_Type representation, and we need to
11882 -- go back to the original access type definition using the
11883 -- Corresponding_Remote_Type attribute in order to check that the
11884 -- designated profiles match.
11886 pragma Assert (Ekind (Target_Type) = E_Record_Type);
11887 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
11889 Check_Subtype_Conformant
11891 Designated_Type (Corresponding_Remote_Type (Target_Type)),
11893 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
11898 -- If it was legal in the generic, it's legal in the instance
11900 elsif In_Instance_Body then
11903 -- If both are tagged types, check legality of view conversions
11905 elsif Is_Tagged_Type (Target_Type)
11907 Is_Tagged_Type (Opnd_Type)
11909 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
11911 -- Types derived from the same root type are convertible
11913 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
11916 -- In an instance or an inlined body, there may be inconsistent views of
11917 -- the same type, or of types derived from a common root.
11919 elsif (In_Instance or In_Inlined_Body)
11921 Root_Type (Underlying_Type (Target_Type)) =
11922 Root_Type (Underlying_Type (Opnd_Type))
11926 -- Special check for common access type error case
11928 elsif Ekind (Target_Type) = E_Access_Type
11929 and then Is_Access_Type (Opnd_Type)
11931 Conversion_Error_N ("target type must be general access type!", N);
11932 Conversion_Error_NE -- CODEFIX
11933 ("add ALL to }!", N, Target_Type);
11936 -- Here we have a real conversion error
11939 Conversion_Error_NE
11940 ("invalid conversion, not compatible with }", N, Opnd_Type);
11943 end Valid_Conversion;