1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, 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 Ghost; use Ghost;
41 with Inline; use Inline;
42 with Itypes; use Itypes;
44 with Lib.Xref; use Lib.Xref;
45 with Namet; use Namet;
46 with Nmake; use Nmake;
47 with Nlists; use Nlists;
49 with Output; use Output;
50 with Par_SCO; use Par_SCO;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Aggr; use Sem_Aggr;
57 with Sem_Attr; use Sem_Attr;
58 with Sem_Cat; use Sem_Cat;
59 with Sem_Ch4; use Sem_Ch4;
60 with Sem_Ch6; use Sem_Ch6;
61 with Sem_Ch8; use Sem_Ch8;
62 with Sem_Ch13; use Sem_Ch13;
63 with Sem_Dim; use Sem_Dim;
64 with Sem_Disp; use Sem_Disp;
65 with Sem_Dist; use Sem_Dist;
66 with Sem_Elim; use Sem_Elim;
67 with Sem_Elab; use Sem_Elab;
68 with Sem_Eval; use Sem_Eval;
69 with Sem_Intr; use Sem_Intr;
70 with Sem_Util; use Sem_Util;
71 with Targparm; use Targparm;
72 with Sem_Type; use Sem_Type;
73 with Sem_Warn; use Sem_Warn;
74 with Sinfo; use Sinfo;
75 with Sinfo.CN; use Sinfo.CN;
76 with Snames; use Snames;
77 with Stand; use Stand;
78 with Stringt; use Stringt;
79 with Style; use Style;
80 with Tbuild; use Tbuild;
81 with Uintp; use Uintp;
82 with Urealp; use Urealp;
84 package body Sem_Res is
86 -----------------------
87 -- Local Subprograms --
88 -----------------------
90 -- Second pass (top-down) type checking and overload resolution procedures
91 -- Typ is the type required by context. These procedures propagate the
92 -- type information recursively to the descendants of N. If the node is not
93 -- overloaded, its Etype is established in the first pass. If overloaded,
94 -- the Resolve routines set the correct type. For arithmetic operators, the
95 -- Etype is the base type of the context.
97 -- Note that Resolve_Attribute is separated off in Sem_Attr
99 procedure Check_Discriminant_Use (N : Node_Id);
100 -- Enforce the restrictions on the use of discriminants when constraining
101 -- a component of a discriminated type (record or concurrent type).
103 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
104 -- Given a node for an operator associated with type T, check that the
105 -- operator is visible. Operators all of whose operands are universal must
106 -- be checked for visibility during resolution because their type is not
107 -- determinable based on their operands.
109 procedure Check_Fully_Declared_Prefix
112 -- Check that the type of the prefix of a dereference is not incomplete
114 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
115 -- Given a call node, N, which is known to occur immediately within the
116 -- subprogram being called, determines whether it is a detectable case of
117 -- an infinite recursion, and if so, outputs appropriate messages. Returns
118 -- True if an infinite recursion is detected, and False otherwise.
120 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
121 -- If the type of the object being initialized uses the secondary stack
122 -- directly or indirectly, create a transient scope for the call to the
123 -- init proc. This is because we do not create transient scopes for the
124 -- initialization of individual components within the init proc itself.
125 -- Could be optimized away perhaps?
127 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
128 -- N is the node for a logical operator. If the operator is predefined, and
129 -- the root type of the operands is Standard.Boolean, then a check is made
130 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
131 -- the style check for Style_Check_Boolean_And_Or.
133 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
134 -- N is either an indexed component or a selected component. This function
135 -- returns true if the prefix refers to an object that has an address
136 -- clause (the case in which we may want to issue a warning).
138 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
139 -- Determine whether E is an access type declared by an access declaration,
140 -- and not an (anonymous) allocator type.
142 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
143 -- Utility to check whether the entity for an operator is a predefined
144 -- operator, in which case the expression is left as an operator in the
145 -- tree (else it is rewritten into a call). An instance of an intrinsic
146 -- conversion operation may be given an operator name, but is not treated
147 -- like an operator. Note that an operator that is an imported back-end
148 -- builtin has convention Intrinsic, but is expected to be rewritten into
149 -- a call, so such an operator is not treated as predefined by this
152 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
153 -- If a default expression in entry call N depends on the discriminants
154 -- of the task, it must be replaced with a reference to the discriminant
155 -- of the task being called.
157 procedure Resolve_Op_Concat_Arg
162 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
163 -- concatenation operator. The operand is either of the array type or of
164 -- the component type. If the operand is an aggregate, and the component
165 -- type is composite, this is ambiguous if component type has aggregates.
167 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
168 -- Does the first part of the work of Resolve_Op_Concat
170 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
171 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
172 -- has been resolved. See Resolve_Op_Concat for details.
174 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
210 function Operator_Kind
212 Is_Binary : Boolean) return Node_Kind;
213 -- Utility to map the name of an operator into the corresponding Node. Used
214 -- by other node rewriting procedures.
216 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
217 -- Resolve actuals of call, and add default expressions for missing ones.
218 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
219 -- called subprogram.
221 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
222 -- Called from Resolve_Call, when the prefix denotes an entry or element
223 -- of entry family. Actuals are resolved as for subprograms, and the node
224 -- is rebuilt as an entry call. Also called for protected operations. Typ
225 -- is the context type, which is used when the operation is a protected
226 -- function with no arguments, and the return value is indexed.
228 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
229 -- A call to a user-defined intrinsic operator is rewritten as a call to
230 -- the corresponding predefined operator, with suitable conversions. Note
231 -- that this applies only for intrinsic operators that denote predefined
232 -- operators, not ones that are intrinsic imports of back-end builtins.
234 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
235 -- Ditto, for arithmetic unary operators
237 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
238 -- If an operator node resolves to a call to a user-defined operator,
239 -- rewrite the node as a function call.
241 procedure Make_Call_Into_Operator
245 -- Inverse transformation: if an operator is given in functional notation,
246 -- then after resolving the node, transform into an operator node, so that
247 -- operands are resolved properly. Recall that predefined operators do not
248 -- have a full signature and special resolution rules apply.
250 procedure Rewrite_Renamed_Operator
254 -- An operator can rename another, e.g. in an instantiation. In that
255 -- case, the proper operator node must be constructed and resolved.
257 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
258 -- The String_Literal_Subtype is built for all strings that are not
259 -- operands of a static concatenation operation. If the argument is not
260 -- a N_String_Literal node, then the call has no effect.
262 procedure Set_Slice_Subtype (N : Node_Id);
263 -- Build subtype of array type, with the range specified by the slice
265 procedure Simplify_Type_Conversion (N : Node_Id);
266 -- Called after N has been resolved and evaluated, but before range checks
267 -- have been applied. Currently simplifies a combination of floating-point
268 -- to integer conversion and Rounding or Truncation attribute.
270 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
271 -- A universal_fixed expression in an universal context is unambiguous if
272 -- there is only one applicable fixed point type. Determining whether there
273 -- is only one requires a search over all visible entities, and happens
274 -- only in very pathological cases (see 6115-006).
276 -------------------------
277 -- Ambiguous_Character --
278 -------------------------
280 procedure Ambiguous_Character (C : Node_Id) is
284 if Nkind (C) = N_Character_Literal then
285 Error_Msg_N ("ambiguous character literal", C);
287 -- First the ones in Standard
289 Error_Msg_N ("\\possible interpretation: Character!", C);
290 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
292 -- Include Wide_Wide_Character in Ada 2005 mode
294 if Ada_Version >= Ada_2005 then
295 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
298 -- Now any other types that match
300 E := Current_Entity (C);
301 while Present (E) loop
302 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
306 end Ambiguous_Character;
308 -------------------------
309 -- Analyze_And_Resolve --
310 -------------------------
312 procedure Analyze_And_Resolve (N : Node_Id) is
316 end Analyze_And_Resolve;
318 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
322 end Analyze_And_Resolve;
324 -- Versions with check(s) suppressed
326 procedure Analyze_And_Resolve
331 Scop : constant Entity_Id := Current_Scope;
334 if Suppress = All_Checks then
336 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
338 Scope_Suppress.Suppress := (others => True);
339 Analyze_And_Resolve (N, Typ);
340 Scope_Suppress.Suppress := Sva;
345 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
347 Scope_Suppress.Suppress (Suppress) := True;
348 Analyze_And_Resolve (N, Typ);
349 Scope_Suppress.Suppress (Suppress) := Svg;
353 if Current_Scope /= Scop
354 and then Scope_Is_Transient
356 -- This can only happen if a transient scope was created for an inner
357 -- expression, which will be removed upon completion of the analysis
358 -- of an enclosing construct. The transient scope must have the
359 -- suppress status of the enclosing environment, not of this Analyze
362 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
365 end Analyze_And_Resolve;
367 procedure Analyze_And_Resolve
371 Scop : constant Entity_Id := Current_Scope;
374 if Suppress = All_Checks then
376 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
378 Scope_Suppress.Suppress := (others => True);
379 Analyze_And_Resolve (N);
380 Scope_Suppress.Suppress := Sva;
385 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
387 Scope_Suppress.Suppress (Suppress) := True;
388 Analyze_And_Resolve (N);
389 Scope_Suppress.Suppress (Suppress) := Svg;
393 if Current_Scope /= Scop and then Scope_Is_Transient then
394 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
397 end Analyze_And_Resolve;
399 ----------------------------
400 -- Check_Discriminant_Use --
401 ----------------------------
403 procedure Check_Discriminant_Use (N : Node_Id) is
404 PN : constant Node_Id := Parent (N);
405 Disc : constant Entity_Id := Entity (N);
410 -- Any use in a spec-expression is legal
412 if In_Spec_Expression then
415 elsif Nkind (PN) = N_Range then
417 -- Discriminant cannot be used to constrain a scalar type
421 if Nkind (P) = N_Range_Constraint
422 and then Nkind (Parent (P)) = N_Subtype_Indication
423 and then Nkind (Parent (Parent (P))) = N_Component_Definition
425 Error_Msg_N ("discriminant cannot constrain scalar type", N);
427 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
429 -- The following check catches the unusual case where a
430 -- discriminant appears within an index constraint that is part
431 -- of a larger expression within a constraint on a component,
432 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
433 -- check case of record components, and note that a similar check
434 -- should also apply in the case of discriminant constraints
437 -- Note that the check for N_Subtype_Declaration below is to
438 -- detect the valid use of discriminants in the constraints of a
439 -- subtype declaration when this subtype declaration appears
440 -- inside the scope of a record type (which is syntactically
441 -- illegal, but which may be created as part of derived type
442 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
445 if Ekind (Current_Scope) = E_Record_Type
446 and then Scope (Disc) = Current_Scope
448 (Nkind (Parent (P)) = N_Subtype_Indication
450 Nkind_In (Parent (Parent (P)), N_Component_Definition,
451 N_Subtype_Declaration)
452 and then Paren_Count (N) = 0)
455 ("discriminant must appear alone in component constraint", N);
459 -- Detect a common error:
461 -- type R (D : Positive := 100) is record
462 -- Name : String (1 .. D);
465 -- The default value causes an object of type R to be allocated
466 -- with room for Positive'Last characters. The RM does not mandate
467 -- the allocation of the maximum size, but that is what GNAT does
468 -- so we should warn the programmer that there is a problem.
470 Check_Large : declare
476 function Large_Storage_Type (T : Entity_Id) return Boolean;
477 -- Return True if type T has a large enough range that any
478 -- array whose index type covered the whole range of the type
479 -- would likely raise Storage_Error.
481 ------------------------
482 -- Large_Storage_Type --
483 ------------------------
485 function Large_Storage_Type (T : Entity_Id) return Boolean is
487 -- The type is considered large if its bounds are known at
488 -- compile time and if it requires at least as many bits as
489 -- a Positive to store the possible values.
491 return Compile_Time_Known_Value (Type_Low_Bound (T))
492 and then Compile_Time_Known_Value (Type_High_Bound (T))
494 Minimum_Size (T, Biased => True) >=
495 RM_Size (Standard_Positive);
496 end Large_Storage_Type;
498 -- Start of processing for Check_Large
501 -- Check that the Disc has a large range
503 if not Large_Storage_Type (Etype (Disc)) then
507 -- If the enclosing type is limited, we allocate only the
508 -- default value, not the maximum, and there is no need for
511 if Is_Limited_Type (Scope (Disc)) then
515 -- Check that it is the high bound
517 if N /= High_Bound (PN)
518 or else No (Discriminant_Default_Value (Disc))
523 -- Check the array allows a large range at this bound. First
528 if Nkind (SI) /= N_Subtype_Indication then
532 T := Entity (Subtype_Mark (SI));
534 if not Is_Array_Type (T) then
538 -- Next, find the dimension
540 TB := First_Index (T);
541 CB := First (Constraints (P));
543 and then Present (TB)
544 and then Present (CB)
555 -- Now, check the dimension has a large range
557 if not Large_Storage_Type (Etype (TB)) then
561 -- Warn about the danger
564 ("??creation of & object may raise Storage_Error!",
573 -- Legal case is in index or discriminant constraint
575 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
576 N_Discriminant_Association)
578 if Paren_Count (N) > 0 then
580 ("discriminant in constraint must appear alone", N);
582 elsif Nkind (N) = N_Expanded_Name
583 and then Comes_From_Source (N)
586 ("discriminant must appear alone as a direct name", N);
591 -- Otherwise, context is an expression. It should not be within (i.e. a
592 -- subexpression of) a constraint for a component.
597 while not Nkind_In (P, N_Component_Declaration,
598 N_Subtype_Indication,
606 -- If the discriminant is used in an expression that is a bound of a
607 -- scalar type, an Itype is created and the bounds are attached to
608 -- its range, not to the original subtype indication. Such use is of
609 -- course a double fault.
611 if (Nkind (P) = N_Subtype_Indication
612 and then Nkind_In (Parent (P), N_Component_Definition,
613 N_Derived_Type_Definition)
614 and then D = Constraint (P))
616 -- The constraint itself may be given by a subtype indication,
617 -- rather than by a more common discrete range.
619 or else (Nkind (P) = N_Subtype_Indication
621 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
622 or else Nkind (P) = N_Entry_Declaration
623 or else Nkind (D) = N_Defining_Identifier
626 ("discriminant in constraint must appear alone", N);
629 end Check_Discriminant_Use;
631 --------------------------------
632 -- Check_For_Visible_Operator --
633 --------------------------------
635 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
637 if Is_Invisible_Operator (N, T) then
638 Error_Msg_NE -- CODEFIX
639 ("operator for} is not directly visible!", N, First_Subtype (T));
640 Error_Msg_N -- CODEFIX
641 ("use clause would make operation legal!", N);
643 end Check_For_Visible_Operator;
645 ----------------------------------
646 -- Check_Fully_Declared_Prefix --
647 ----------------------------------
649 procedure Check_Fully_Declared_Prefix
654 -- Check that the designated type of the prefix of a dereference is
655 -- not an incomplete type. This cannot be done unconditionally, because
656 -- dereferences of private types are legal in default expressions. This
657 -- case is taken care of in Check_Fully_Declared, called below. There
658 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
660 -- This consideration also applies to similar checks for allocators,
661 -- qualified expressions, and type conversions.
663 -- An additional exception concerns other per-object expressions that
664 -- are not directly related to component declarations, in particular
665 -- representation pragmas for tasks. These will be per-object
666 -- expressions if they depend on discriminants or some global entity.
667 -- If the task has access discriminants, the designated type may be
668 -- incomplete at the point the expression is resolved. This resolution
669 -- takes place within the body of the initialization procedure, where
670 -- the discriminant is replaced by its discriminal.
672 if Is_Entity_Name (Pref)
673 and then Ekind (Entity (Pref)) = E_In_Parameter
677 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
678 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
679 -- Analyze_Object_Renaming, and Freeze_Entity.
681 elsif Ada_Version >= Ada_2005
682 and then Is_Entity_Name (Pref)
683 and then Is_Access_Type (Etype (Pref))
684 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
686 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
690 Check_Fully_Declared (Typ, Parent (Pref));
692 end Check_Fully_Declared_Prefix;
694 ------------------------------
695 -- Check_Infinite_Recursion --
696 ------------------------------
698 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
702 function Same_Argument_List return Boolean;
703 -- Check whether list of actuals is identical to list of formals of
704 -- called function (which is also the enclosing scope).
706 ------------------------
707 -- Same_Argument_List --
708 ------------------------
710 function Same_Argument_List return Boolean is
716 if not Is_Entity_Name (Name (N)) then
719 Subp := Entity (Name (N));
722 F := First_Formal (Subp);
723 A := First_Actual (N);
724 while Present (F) and then Present (A) loop
725 if not Is_Entity_Name (A) or else Entity (A) /= F then
734 end Same_Argument_List;
736 -- Start of processing for Check_Infinite_Recursion
739 -- Special case, if this is a procedure call and is a call to the
740 -- current procedure with the same argument list, then this is for
741 -- sure an infinite recursion and we insert a call to raise SE.
743 if Is_List_Member (N)
744 and then List_Length (List_Containing (N)) = 1
745 and then Same_Argument_List
748 P : constant Node_Id := Parent (N);
750 if Nkind (P) = N_Handled_Sequence_Of_Statements
751 and then Nkind (Parent (P)) = N_Subprogram_Body
752 and then Is_Empty_List (Declarations (Parent (P)))
754 Error_Msg_Warn := SPARK_Mode /= On;
755 Error_Msg_N ("!infinite recursion<<", N);
756 Error_Msg_N ("\!Storage_Error [<<", N);
758 Make_Raise_Storage_Error (Sloc (N),
759 Reason => SE_Infinite_Recursion));
765 -- If not that special case, search up tree, quitting if we reach a
766 -- construct (e.g. a conditional) that tells us that this is not a
767 -- case for an infinite recursion warning.
773 -- If no parent, then we were not inside a subprogram, this can for
774 -- example happen when processing certain pragmas in a spec. Just
775 -- return False in this case.
781 -- Done if we get to subprogram body, this is definitely an infinite
782 -- recursion case if we did not find anything to stop us.
784 exit when Nkind (P) = N_Subprogram_Body;
786 -- If appearing in conditional, result is false
788 if Nkind_In (P, N_Or_Else,
797 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
798 and then C /= First (Statements (P))
800 -- If the call is the expression of a return statement and the
801 -- actuals are identical to the formals, it's worth a warning.
802 -- However, we skip this if there is an immediately preceding
803 -- raise statement, since the call is never executed.
805 -- Furthermore, this corresponds to a common idiom:
807 -- function F (L : Thing) return Boolean is
809 -- raise Program_Error;
813 -- for generating a stub function
815 if Nkind (Parent (N)) = N_Simple_Return_Statement
816 and then Same_Argument_List
818 exit when not Is_List_Member (Parent (N));
820 -- OK, return statement is in a statement list, look for raise
826 -- Skip past N_Freeze_Entity nodes generated by expansion
828 Nod := Prev (Parent (N));
830 and then Nkind (Nod) = N_Freeze_Entity
835 -- If no raise statement, give warning. We look at the
836 -- original node, because in the case of "raise ... with
837 -- ...", the node has been transformed into a call.
839 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
841 (Nkind (Nod) not in N_Raise_xxx_Error
842 or else Present (Condition (Nod)));
853 Error_Msg_Warn := SPARK_Mode /= On;
854 Error_Msg_N ("!possible infinite recursion<<", N);
855 Error_Msg_N ("\!??Storage_Error ]<<", N);
858 end Check_Infinite_Recursion;
860 -------------------------------
861 -- Check_Initialization_Call --
862 -------------------------------
864 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
865 Typ : constant Entity_Id := Etype (First_Formal (Nam));
867 function Uses_SS (T : Entity_Id) return Boolean;
868 -- Check whether the creation of an object of the type will involve
869 -- use of the secondary stack. If T is a record type, this is true
870 -- if the expression for some component uses the secondary stack, e.g.
871 -- through a call to a function that returns an unconstrained value.
872 -- False if T is controlled, because cleanups occur elsewhere.
878 function Uses_SS (T : Entity_Id) return Boolean is
881 Full_Type : Entity_Id := Underlying_Type (T);
884 -- Normally we want to use the underlying type, but if it's not set
885 -- then continue with T.
887 if not Present (Full_Type) then
891 if Is_Controlled (Full_Type) then
894 elsif Is_Array_Type (Full_Type) then
895 return Uses_SS (Component_Type (Full_Type));
897 elsif Is_Record_Type (Full_Type) then
898 Comp := First_Component (Full_Type);
899 while Present (Comp) loop
900 if Ekind (Comp) = E_Component
901 and then Nkind (Parent (Comp)) = N_Component_Declaration
903 -- The expression for a dynamic component may be rewritten
904 -- as a dereference, so retrieve original node.
906 Expr := Original_Node (Expression (Parent (Comp)));
908 -- Return True if the expression is a call to a function
909 -- (including an attribute function such as Image, or a
910 -- user-defined operator) with a result that requires a
913 if (Nkind (Expr) = N_Function_Call
914 or else Nkind (Expr) in N_Op
915 or else (Nkind (Expr) = N_Attribute_Reference
916 and then Present (Expressions (Expr))))
917 and then Requires_Transient_Scope (Etype (Expr))
921 elsif Uses_SS (Etype (Comp)) then
926 Next_Component (Comp);
936 -- Start of processing for Check_Initialization_Call
939 -- Establish a transient scope if the type needs it
941 if Uses_SS (Typ) then
942 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
944 end Check_Initialization_Call;
946 ---------------------------------------
947 -- Check_No_Direct_Boolean_Operators --
948 ---------------------------------------
950 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
952 if Scope (Entity (N)) = Standard_Standard
953 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
955 -- Restriction only applies to original source code
957 if Comes_From_Source (N) then
958 Check_Restriction (No_Direct_Boolean_Operators, N);
962 -- Do style check (but skip if in instance, error is on template)
965 if not In_Instance then
966 Check_Boolean_Operator (N);
969 end Check_No_Direct_Boolean_Operators;
971 ------------------------------
972 -- Check_Parameterless_Call --
973 ------------------------------
975 procedure Check_Parameterless_Call (N : Node_Id) is
978 function Prefix_Is_Access_Subp return Boolean;
979 -- If the prefix is of an access_to_subprogram type, the node must be
980 -- rewritten as a call. Ditto if the prefix is overloaded and all its
981 -- interpretations are access to subprograms.
983 ---------------------------
984 -- Prefix_Is_Access_Subp --
985 ---------------------------
987 function Prefix_Is_Access_Subp return Boolean is
992 -- If the context is an attribute reference that can apply to
993 -- functions, this is never a parameterless call (RM 4.1.4(6)).
995 if Nkind (Parent (N)) = N_Attribute_Reference
996 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1003 if not Is_Overloaded (N) then
1005 Ekind (Etype (N)) = E_Subprogram_Type
1006 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1008 Get_First_Interp (N, I, It);
1009 while Present (It.Typ) loop
1010 if Ekind (It.Typ) /= E_Subprogram_Type
1011 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1016 Get_Next_Interp (I, It);
1021 end Prefix_Is_Access_Subp;
1023 -- Start of processing for Check_Parameterless_Call
1026 -- Defend against junk stuff if errors already detected
1028 if Total_Errors_Detected /= 0 then
1029 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1031 elsif Nkind (N) in N_Has_Chars
1032 and then Chars (N) in Error_Name_Or_No_Name
1040 -- If the context expects a value, and the name is a procedure, this is
1041 -- most likely a missing 'Access. Don't try to resolve the parameterless
1042 -- call, error will be caught when the outer call is analyzed.
1044 if Is_Entity_Name (N)
1045 and then Ekind (Entity (N)) = E_Procedure
1046 and then not Is_Overloaded (N)
1048 Nkind_In (Parent (N), N_Parameter_Association,
1050 N_Procedure_Call_Statement)
1055 -- Rewrite as call if overloadable entity that is (or could be, in the
1056 -- overloaded case) a function call. If we know for sure that the entity
1057 -- is an enumeration literal, we do not rewrite it.
1059 -- If the entity is the name of an operator, it cannot be a call because
1060 -- operators cannot have default parameters. In this case, this must be
1061 -- a string whose contents coincide with an operator name. Set the kind
1062 -- of the node appropriately.
1064 if (Is_Entity_Name (N)
1065 and then Nkind (N) /= N_Operator_Symbol
1066 and then Is_Overloadable (Entity (N))
1067 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1068 or else Is_Overloaded (N)))
1070 -- Rewrite as call if it is an explicit dereference of an expression of
1071 -- a subprogram access type, and the subprogram type is not that of a
1072 -- procedure or entry.
1075 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1077 -- Rewrite as call if it is a selected component which is a function,
1078 -- this is the case of a call to a protected function (which may be
1079 -- overloaded with other protected operations).
1082 (Nkind (N) = N_Selected_Component
1083 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1085 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1087 and then Is_Overloaded (Selector_Name (N)))))
1089 -- If one of the above three conditions is met, rewrite as call. Apply
1090 -- the rewriting only once.
1093 if Nkind (Parent (N)) /= N_Function_Call
1094 or else N /= Name (Parent (N))
1097 -- This may be a prefixed call that was not fully analyzed, e.g.
1098 -- an actual in an instance.
1100 if Ada_Version >= Ada_2005
1101 and then Nkind (N) = N_Selected_Component
1102 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1104 Analyze_Selected_Component (N);
1106 if Nkind (N) /= N_Selected_Component then
1111 -- The node is the name of the parameterless call. Preserve its
1112 -- descendants, which may be complex expressions.
1114 Nam := Relocate_Node (N);
1116 -- If overloaded, overload set belongs to new copy
1118 Save_Interps (N, Nam);
1120 -- Change node to parameterless function call (note that the
1121 -- Parameter_Associations associations field is left set to Empty,
1122 -- its normal default value since there are no parameters)
1124 Change_Node (N, N_Function_Call);
1126 Set_Sloc (N, Sloc (Nam));
1130 elsif Nkind (N) = N_Parameter_Association then
1131 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1133 elsif Nkind (N) = N_Operator_Symbol then
1134 Change_Operator_Symbol_To_String_Literal (N);
1135 Set_Is_Overloaded (N, False);
1136 Set_Etype (N, Any_String);
1138 end Check_Parameterless_Call;
1140 --------------------------------
1141 -- Is_Atomic_Ref_With_Address --
1142 --------------------------------
1144 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1145 Pref : constant Node_Id := Prefix (N);
1148 if not Is_Entity_Name (Pref) then
1153 Pent : constant Entity_Id := Entity (Pref);
1154 Ptyp : constant Entity_Id := Etype (Pent);
1156 return not Is_Access_Type (Ptyp)
1157 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1158 and then Present (Address_Clause (Pent));
1161 end Is_Atomic_Ref_With_Address;
1163 -----------------------------
1164 -- Is_Definite_Access_Type --
1165 -----------------------------
1167 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1168 Btyp : constant Entity_Id := Base_Type (E);
1170 return Ekind (Btyp) = E_Access_Type
1171 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1172 and then Comes_From_Source (Btyp));
1173 end Is_Definite_Access_Type;
1175 ----------------------
1176 -- Is_Predefined_Op --
1177 ----------------------
1179 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1181 -- Predefined operators are intrinsic subprograms
1183 if not Is_Intrinsic_Subprogram (Nam) then
1187 -- A call to a back-end builtin is never a predefined operator
1189 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1193 return not Is_Generic_Instance (Nam)
1194 and then Chars (Nam) in Any_Operator_Name
1195 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1196 end Is_Predefined_Op;
1198 -----------------------------
1199 -- Make_Call_Into_Operator --
1200 -----------------------------
1202 procedure Make_Call_Into_Operator
1207 Op_Name : constant Name_Id := Chars (Op_Id);
1208 Act1 : Node_Id := First_Actual (N);
1209 Act2 : Node_Id := Next_Actual (Act1);
1210 Error : Boolean := False;
1211 Func : constant Entity_Id := Entity (Name (N));
1212 Is_Binary : constant Boolean := Present (Act2);
1214 Opnd_Type : Entity_Id;
1215 Orig_Type : Entity_Id := Empty;
1218 type Kind_Test is access function (E : Entity_Id) return Boolean;
1220 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1221 -- If the operand is not universal, and the operator is given by an
1222 -- expanded name, verify that the operand has an interpretation with a
1223 -- type defined in the given scope of the operator.
1225 function Type_In_P (Test : Kind_Test) return Entity_Id;
1226 -- Find a type of the given class in package Pack that contains the
1229 ---------------------------
1230 -- Operand_Type_In_Scope --
1231 ---------------------------
1233 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1234 Nod : constant Node_Id := Right_Opnd (Op_Node);
1239 if not Is_Overloaded (Nod) then
1240 return Scope (Base_Type (Etype (Nod))) = S;
1243 Get_First_Interp (Nod, I, It);
1244 while Present (It.Typ) loop
1245 if Scope (Base_Type (It.Typ)) = S then
1249 Get_Next_Interp (I, It);
1254 end Operand_Type_In_Scope;
1260 function Type_In_P (Test : Kind_Test) return Entity_Id is
1263 function In_Decl return Boolean;
1264 -- Verify that node is not part of the type declaration for the
1265 -- candidate type, which would otherwise be invisible.
1271 function In_Decl return Boolean is
1272 Decl_Node : constant Node_Id := Parent (E);
1278 if Etype (E) = Any_Type then
1281 elsif No (Decl_Node) then
1286 and then Nkind (N2) /= N_Compilation_Unit
1288 if N2 = Decl_Node then
1299 -- Start of processing for Type_In_P
1302 -- If the context type is declared in the prefix package, this is the
1303 -- desired base type.
1305 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1306 return Base_Type (Typ);
1309 E := First_Entity (Pack);
1310 while Present (E) loop
1311 if Test (E) and then not In_Decl then
1322 -- Start of processing for Make_Call_Into_Operator
1325 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1330 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1331 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1332 Save_Interps (Act1, Left_Opnd (Op_Node));
1333 Save_Interps (Act2, Right_Opnd (Op_Node));
1334 Act1 := Left_Opnd (Op_Node);
1335 Act2 := Right_Opnd (Op_Node);
1340 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1341 Save_Interps (Act1, Right_Opnd (Op_Node));
1342 Act1 := Right_Opnd (Op_Node);
1345 -- If the operator is denoted by an expanded name, and the prefix is
1346 -- not Standard, but the operator is a predefined one whose scope is
1347 -- Standard, then this is an implicit_operator, inserted as an
1348 -- interpretation by the procedure of the same name. This procedure
1349 -- overestimates the presence of implicit operators, because it does
1350 -- not examine the type of the operands. Verify now that the operand
1351 -- type appears in the given scope. If right operand is universal,
1352 -- check the other operand. In the case of concatenation, either
1353 -- argument can be the component type, so check the type of the result.
1354 -- If both arguments are literals, look for a type of the right kind
1355 -- defined in the given scope. This elaborate nonsense is brought to
1356 -- you courtesy of b33302a. The type itself must be frozen, so we must
1357 -- find the type of the proper class in the given scope.
1359 -- A final wrinkle is the multiplication operator for fixed point types,
1360 -- which is defined in Standard only, and not in the scope of the
1361 -- fixed point type itself.
1363 if Nkind (Name (N)) = N_Expanded_Name then
1364 Pack := Entity (Prefix (Name (N)));
1366 -- If this is a package renaming, get renamed entity, which will be
1367 -- the scope of the operands if operaton is type-correct.
1369 if Present (Renamed_Entity (Pack)) then
1370 Pack := Renamed_Entity (Pack);
1373 -- If the entity being called is defined in the given package, it is
1374 -- a renaming of a predefined operator, and known to be legal.
1376 if Scope (Entity (Name (N))) = Pack
1377 and then Pack /= Standard_Standard
1381 -- Visibility does not need to be checked in an instance: if the
1382 -- operator was not visible in the generic it has been diagnosed
1383 -- already, else there is an implicit copy of it in the instance.
1385 elsif In_Instance then
1388 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1389 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1390 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1392 if Pack /= Standard_Standard then
1396 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1399 elsif Ada_Version >= Ada_2005
1400 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1401 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1406 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1408 if Op_Name = Name_Op_Concat then
1409 Opnd_Type := Base_Type (Typ);
1411 elsif (Scope (Opnd_Type) = Standard_Standard
1413 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1415 and then not Comes_From_Source (Opnd_Type))
1417 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1420 if Scope (Opnd_Type) = Standard_Standard then
1422 -- Verify that the scope contains a type that corresponds to
1423 -- the given literal. Optimize the case where Pack is Standard.
1425 if Pack /= Standard_Standard then
1427 if Opnd_Type = Universal_Integer then
1428 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1430 elsif Opnd_Type = Universal_Real then
1431 Orig_Type := Type_In_P (Is_Real_Type'Access);
1433 elsif Opnd_Type = Any_String then
1434 Orig_Type := Type_In_P (Is_String_Type'Access);
1436 elsif Opnd_Type = Any_Access then
1437 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1439 elsif Opnd_Type = Any_Composite then
1440 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1442 if Present (Orig_Type) then
1443 if Has_Private_Component (Orig_Type) then
1446 Set_Etype (Act1, Orig_Type);
1449 Set_Etype (Act2, Orig_Type);
1458 Error := No (Orig_Type);
1461 elsif Ekind (Opnd_Type) = E_Allocator_Type
1462 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1466 -- If the type is defined elsewhere, and the operator is not
1467 -- defined in the given scope (by a renaming declaration, e.g.)
1468 -- then this is an error as well. If an extension of System is
1469 -- present, and the type may be defined there, Pack must be
1472 elsif Scope (Opnd_Type) /= Pack
1473 and then Scope (Op_Id) /= Pack
1474 and then (No (System_Aux_Id)
1475 or else Scope (Opnd_Type) /= System_Aux_Id
1476 or else Pack /= Scope (System_Aux_Id))
1478 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1481 Error := not Operand_Type_In_Scope (Pack);
1484 elsif Pack = Standard_Standard
1485 and then not Operand_Type_In_Scope (Standard_Standard)
1492 Error_Msg_Node_2 := Pack;
1494 ("& not declared in&", N, Selector_Name (Name (N)));
1495 Set_Etype (N, Any_Type);
1498 -- Detect a mismatch between the context type and the result type
1499 -- in the named package, which is otherwise not detected if the
1500 -- operands are universal. Check is only needed if source entity is
1501 -- an operator, not a function that renames an operator.
1503 elsif Nkind (Parent (N)) /= N_Type_Conversion
1504 and then Ekind (Entity (Name (N))) = E_Operator
1505 and then Is_Numeric_Type (Typ)
1506 and then not Is_Universal_Numeric_Type (Typ)
1507 and then Scope (Base_Type (Typ)) /= Pack
1508 and then not In_Instance
1510 if Is_Fixed_Point_Type (Typ)
1511 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1513 -- Already checked above
1517 -- Operator may be defined in an extension of System
1519 elsif Present (System_Aux_Id)
1520 and then Scope (Opnd_Type) = System_Aux_Id
1525 -- Could we use Wrong_Type here??? (this would require setting
1526 -- Etype (N) to the actual type found where Typ was expected).
1528 Error_Msg_NE ("expect }", N, Typ);
1533 Set_Chars (Op_Node, Op_Name);
1535 if not Is_Private_Type (Etype (N)) then
1536 Set_Etype (Op_Node, Base_Type (Etype (N)));
1538 Set_Etype (Op_Node, Etype (N));
1541 -- If this is a call to a function that renames a predefined equality,
1542 -- the renaming declaration provides a type that must be used to
1543 -- resolve the operands. This must be done now because resolution of
1544 -- the equality node will not resolve any remaining ambiguity, and it
1545 -- assumes that the first operand is not overloaded.
1547 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1548 and then Ekind (Func) = E_Function
1549 and then Is_Overloaded (Act1)
1551 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1552 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1555 Set_Entity (Op_Node, Op_Id);
1556 Generate_Reference (Op_Id, N, ' ');
1558 -- Do rewrite setting Comes_From_Source on the result if the original
1559 -- call came from source. Although it is not strictly the case that the
1560 -- operator as such comes from the source, logically it corresponds
1561 -- exactly to the function call in the source, so it should be marked
1562 -- this way (e.g. to make sure that validity checks work fine).
1565 CS : constant Boolean := Comes_From_Source (N);
1567 Rewrite (N, Op_Node);
1568 Set_Comes_From_Source (N, CS);
1571 -- If this is an arithmetic operator and the result type is private,
1572 -- the operands and the result must be wrapped in conversion to
1573 -- expose the underlying numeric type and expand the proper checks,
1574 -- e.g. on division.
1576 if Is_Private_Type (Typ) then
1578 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1579 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1580 Resolve_Intrinsic_Operator (N, Typ);
1582 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1583 Resolve_Intrinsic_Unary_Operator (N, Typ);
1592 -- If in ASIS_Mode, propagate operand types to original actuals of
1593 -- function call, which would otherwise not be fully resolved. If
1594 -- the call has already been constant-folded, nothing to do. We
1595 -- relocate the operand nodes rather than copy them, to preserve
1596 -- original_node pointers, given that the operands themselves may
1597 -- have been rewritten. If the call was itself a rewriting of an
1598 -- operator node, nothing to do.
1601 and then Nkind (N) in N_Op
1602 and then Nkind (Original_Node (N)) = N_Function_Call
1606 R : constant Node_Id := Right_Opnd (N);
1608 Old_First : constant Node_Id :=
1609 First (Parameter_Associations (Original_Node (N)));
1615 Old_Sec := Next (Old_First);
1617 -- If the original call has named associations, replace the
1618 -- explicit actual parameter in the association with the proper
1619 -- resolved operand.
1621 if Nkind (Old_First) = N_Parameter_Association then
1622 if Chars (Selector_Name (Old_First)) =
1623 Chars (First_Entity (Op_Id))
1625 Rewrite (Explicit_Actual_Parameter (Old_First),
1628 Rewrite (Explicit_Actual_Parameter (Old_First),
1633 Rewrite (Old_First, Relocate_Node (L));
1636 if Nkind (Old_Sec) = N_Parameter_Association then
1637 if Chars (Selector_Name (Old_Sec)) =
1638 Chars (First_Entity (Op_Id))
1640 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1643 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1648 Rewrite (Old_Sec, Relocate_Node (R));
1652 if Nkind (Old_First) = N_Parameter_Association then
1653 Rewrite (Explicit_Actual_Parameter (Old_First),
1656 Rewrite (Old_First, Relocate_Node (R));
1661 Set_Parent (Original_Node (N), Parent (N));
1663 end Make_Call_Into_Operator;
1669 function Operator_Kind
1671 Is_Binary : Boolean) return Node_Kind
1676 -- Use CASE statement or array???
1679 if Op_Name = Name_Op_And then
1681 elsif Op_Name = Name_Op_Or then
1683 elsif Op_Name = Name_Op_Xor then
1685 elsif Op_Name = Name_Op_Eq then
1687 elsif Op_Name = Name_Op_Ne then
1689 elsif Op_Name = Name_Op_Lt then
1691 elsif Op_Name = Name_Op_Le then
1693 elsif Op_Name = Name_Op_Gt then
1695 elsif Op_Name = Name_Op_Ge then
1697 elsif Op_Name = Name_Op_Add then
1699 elsif Op_Name = Name_Op_Subtract then
1700 Kind := N_Op_Subtract;
1701 elsif Op_Name = Name_Op_Concat then
1702 Kind := N_Op_Concat;
1703 elsif Op_Name = Name_Op_Multiply then
1704 Kind := N_Op_Multiply;
1705 elsif Op_Name = Name_Op_Divide then
1706 Kind := N_Op_Divide;
1707 elsif Op_Name = Name_Op_Mod then
1709 elsif Op_Name = Name_Op_Rem then
1711 elsif Op_Name = Name_Op_Expon then
1714 raise Program_Error;
1720 if Op_Name = Name_Op_Add then
1722 elsif Op_Name = Name_Op_Subtract then
1724 elsif Op_Name = Name_Op_Abs then
1726 elsif Op_Name = Name_Op_Not then
1729 raise Program_Error;
1736 ----------------------------
1737 -- Preanalyze_And_Resolve --
1738 ----------------------------
1740 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1741 Save_Full_Analysis : constant Boolean := Full_Analysis;
1744 Full_Analysis := False;
1745 Expander_Mode_Save_And_Set (False);
1747 -- Normally, we suppress all checks for this preanalysis. There is no
1748 -- point in processing them now, since they will be applied properly
1749 -- and in the proper location when the default expressions reanalyzed
1750 -- and reexpanded later on. We will also have more information at that
1751 -- point for possible suppression of individual checks.
1753 -- However, in SPARK mode, most expansion is suppressed, and this
1754 -- later reanalysis and reexpansion may not occur. SPARK mode does
1755 -- require the setting of checking flags for proof purposes, so we
1756 -- do the SPARK preanalysis without suppressing checks.
1758 -- This special handling for SPARK mode is required for example in the
1759 -- case of Ada 2012 constructs such as quantified expressions, which are
1760 -- expanded in two separate steps.
1762 if GNATprove_Mode then
1763 Analyze_And_Resolve (N, T);
1765 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1768 Expander_Mode_Restore;
1769 Full_Analysis := Save_Full_Analysis;
1770 end Preanalyze_And_Resolve;
1772 -- Version without context type
1774 procedure Preanalyze_And_Resolve (N : Node_Id) is
1775 Save_Full_Analysis : constant Boolean := Full_Analysis;
1778 Full_Analysis := False;
1779 Expander_Mode_Save_And_Set (False);
1782 Resolve (N, Etype (N), Suppress => All_Checks);
1784 Expander_Mode_Restore;
1785 Full_Analysis := Save_Full_Analysis;
1786 end Preanalyze_And_Resolve;
1788 ----------------------------------
1789 -- Replace_Actual_Discriminants --
1790 ----------------------------------
1792 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1793 Loc : constant Source_Ptr := Sloc (N);
1794 Tsk : Node_Id := Empty;
1796 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1797 -- Comment needed???
1803 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1807 if Nkind (Nod) = N_Identifier then
1808 Ent := Entity (Nod);
1811 and then Ekind (Ent) = E_Discriminant
1814 Make_Selected_Component (Loc,
1815 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1816 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1818 Set_Etype (Nod, Etype (Ent));
1826 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1828 -- Start of processing for Replace_Actual_Discriminants
1831 if not Expander_Active then
1835 if Nkind (Name (N)) = N_Selected_Component then
1836 Tsk := Prefix (Name (N));
1838 elsif Nkind (Name (N)) = N_Indexed_Component then
1839 Tsk := Prefix (Prefix (Name (N)));
1845 Replace_Discrs (Default);
1847 end Replace_Actual_Discriminants;
1853 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1854 Ambiguous : Boolean := False;
1855 Ctx_Type : Entity_Id := Typ;
1856 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1857 Err_Type : Entity_Id := Empty;
1858 Found : Boolean := False;
1861 I1 : Interp_Index := 0; -- prevent junk warning
1864 Seen : Entity_Id := Empty; -- prevent junk warning
1866 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1867 -- Determine whether a node comes from a predefined library unit or
1870 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1871 -- Try and fix up a literal so that it matches its expected type. New
1872 -- literals are manufactured if necessary to avoid cascaded errors.
1874 procedure Report_Ambiguous_Argument;
1875 -- Additional diagnostics when an ambiguous call has an ambiguous
1876 -- argument (typically a controlling actual).
1878 procedure Resolution_Failed;
1879 -- Called when attempt at resolving current expression fails
1881 ------------------------------------
1882 -- Comes_From_Predefined_Lib_Unit --
1883 -------------------------------------
1885 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1888 Sloc (Nod) = Standard_Location
1889 or else Is_Predefined_File_Name
1890 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1891 end Comes_From_Predefined_Lib_Unit;
1893 --------------------
1894 -- Patch_Up_Value --
1895 --------------------
1897 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1899 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1901 Make_Real_Literal (Sloc (N),
1902 Realval => UR_From_Uint (Intval (N))));
1903 Set_Etype (N, Universal_Real);
1904 Set_Is_Static_Expression (N);
1906 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1908 Make_Integer_Literal (Sloc (N),
1909 Intval => UR_To_Uint (Realval (N))));
1910 Set_Etype (N, Universal_Integer);
1911 Set_Is_Static_Expression (N);
1913 elsif Nkind (N) = N_String_Literal
1914 and then Is_Character_Type (Typ)
1916 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1918 Make_Character_Literal (Sloc (N),
1920 Char_Literal_Value =>
1921 UI_From_Int (Character'Pos ('A'))));
1922 Set_Etype (N, Any_Character);
1923 Set_Is_Static_Expression (N);
1925 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1927 Make_String_Literal (Sloc (N),
1928 Strval => End_String));
1930 elsif Nkind (N) = N_Range then
1931 Patch_Up_Value (Low_Bound (N), Typ);
1932 Patch_Up_Value (High_Bound (N), Typ);
1936 -------------------------------
1937 -- Report_Ambiguous_Argument --
1938 -------------------------------
1940 procedure Report_Ambiguous_Argument is
1941 Arg : constant Node_Id := First (Parameter_Associations (N));
1946 if Nkind (Arg) = N_Function_Call
1947 and then Is_Entity_Name (Name (Arg))
1948 and then Is_Overloaded (Name (Arg))
1950 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1952 -- Could use comments on what is going on here???
1954 Get_First_Interp (Name (Arg), I, It);
1955 while Present (It.Nam) loop
1956 Error_Msg_Sloc := Sloc (It.Nam);
1958 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1959 Error_Msg_N ("interpretation (inherited) #!", Arg);
1961 Error_Msg_N ("interpretation #!", Arg);
1964 Get_Next_Interp (I, It);
1967 end Report_Ambiguous_Argument;
1969 -----------------------
1970 -- Resolution_Failed --
1971 -----------------------
1973 procedure Resolution_Failed is
1975 Patch_Up_Value (N, Typ);
1977 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1978 Set_Is_Overloaded (N, False);
1980 -- The caller will return without calling the expander, so we need
1981 -- to set the analyzed flag. Note that it is fine to set Analyzed
1982 -- to True even if we are in the middle of a shallow analysis,
1983 -- (see the spec of sem for more details) since this is an error
1984 -- situation anyway, and there is no point in repeating the
1985 -- analysis later (indeed it won't work to repeat it later, since
1986 -- we haven't got a clear resolution of which entity is being
1989 Set_Analyzed (N, True);
1991 end Resolution_Failed;
1993 -- Start of processing for Resolve
2000 -- Access attribute on remote subprogram cannot be used for a non-remote
2001 -- access-to-subprogram type.
2003 if Nkind (N) = N_Attribute_Reference
2004 and then Nam_In (Attribute_Name (N), Name_Access,
2005 Name_Unrestricted_Access,
2006 Name_Unchecked_Access)
2007 and then Comes_From_Source (N)
2008 and then Is_Entity_Name (Prefix (N))
2009 and then Is_Subprogram (Entity (Prefix (N)))
2010 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2011 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2014 ("prefix must statically denote a non-remote subprogram", N);
2017 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2019 -- If the context is a Remote_Access_To_Subprogram, access attributes
2020 -- must be resolved with the corresponding fat pointer. There is no need
2021 -- to check for the attribute name since the return type of an
2022 -- attribute is never a remote type.
2024 if Nkind (N) = N_Attribute_Reference
2025 and then Comes_From_Source (N)
2026 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2029 Attr : constant Attribute_Id :=
2030 Get_Attribute_Id (Attribute_Name (N));
2031 Pref : constant Node_Id := Prefix (N);
2034 Is_Remote : Boolean := True;
2037 -- Check that Typ is a remote access-to-subprogram type
2039 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2041 -- Prefix (N) must statically denote a remote subprogram
2042 -- declared in a package specification.
2044 if Attr = Attribute_Access or else
2045 Attr = Attribute_Unchecked_Access or else
2046 Attr = Attribute_Unrestricted_Access
2048 Decl := Unit_Declaration_Node (Entity (Pref));
2050 if Nkind (Decl) = N_Subprogram_Body then
2051 Spec := Corresponding_Spec (Decl);
2053 if Present (Spec) then
2054 Decl := Unit_Declaration_Node (Spec);
2058 Spec := Parent (Decl);
2060 if not Is_Entity_Name (Prefix (N))
2061 or else Nkind (Spec) /= N_Package_Specification
2063 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2067 ("prefix must statically denote a remote subprogram ",
2071 -- If we are generating code in distributed mode, perform
2072 -- semantic checks against corresponding remote entities.
2075 and then Get_PCS_Name /= Name_No_DSA
2077 Check_Subtype_Conformant
2078 (New_Id => Entity (Prefix (N)),
2079 Old_Id => Designated_Type
2080 (Corresponding_Remote_Type (Typ)),
2084 Process_Remote_AST_Attribute (N, Typ);
2092 Debug_A_Entry ("resolving ", N);
2094 if Debug_Flag_V then
2095 Write_Overloads (N);
2098 if Comes_From_Source (N) then
2099 if Is_Fixed_Point_Type (Typ) then
2100 Check_Restriction (No_Fixed_Point, N);
2102 elsif Is_Floating_Point_Type (Typ)
2103 and then Typ /= Universal_Real
2104 and then Typ /= Any_Real
2106 Check_Restriction (No_Floating_Point, N);
2110 -- Return if already analyzed
2112 if Analyzed (N) then
2113 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2114 Analyze_Dimension (N);
2117 -- Any case of Any_Type as the Etype value means that we had a
2120 elsif Etype (N) = Any_Type then
2121 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2125 Check_Parameterless_Call (N);
2127 -- The resolution of an Expression_With_Actions is determined by
2130 if Nkind (N) = N_Expression_With_Actions then
2131 Resolve (Expression (N), Typ);
2134 Expr_Type := Etype (Expression (N));
2136 -- If not overloaded, then we know the type, and all that needs doing
2137 -- is to check that this type is compatible with the context.
2139 elsif not Is_Overloaded (N) then
2140 Found := Covers (Typ, Etype (N));
2141 Expr_Type := Etype (N);
2143 -- In the overloaded case, we must select the interpretation that
2144 -- is compatible with the context (i.e. the type passed to Resolve)
2147 -- Loop through possible interpretations
2149 Get_First_Interp (N, I, It);
2150 Interp_Loop : while Present (It.Typ) loop
2151 if Debug_Flag_V then
2152 Write_Str ("Interp: ");
2156 -- We are only interested in interpretations that are compatible
2157 -- with the expected type, any other interpretations are ignored.
2159 if not Covers (Typ, It.Typ) then
2160 if Debug_Flag_V then
2161 Write_Str (" interpretation incompatible with context");
2166 -- Skip the current interpretation if it is disabled by an
2167 -- abstract operator. This action is performed only when the
2168 -- type against which we are resolving is the same as the
2169 -- type of the interpretation.
2171 if Ada_Version >= Ada_2005
2172 and then It.Typ = Typ
2173 and then Typ /= Universal_Integer
2174 and then Typ /= Universal_Real
2175 and then Present (It.Abstract_Op)
2177 if Debug_Flag_V then
2178 Write_Line ("Skip.");
2184 -- First matching interpretation
2190 Expr_Type := It.Typ;
2192 -- Matching interpretation that is not the first, maybe an
2193 -- error, but there are some cases where preference rules are
2194 -- used to choose between the two possibilities. These and
2195 -- some more obscure cases are handled in Disambiguate.
2198 -- If the current statement is part of a predefined library
2199 -- unit, then all interpretations which come from user level
2200 -- packages should not be considered. Check previous and
2204 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2207 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2209 -- Previous interpretation must be discarded
2213 Expr_Type := It.Typ;
2214 Set_Entity (N, Seen);
2219 -- Otherwise apply further disambiguation steps
2221 Error_Msg_Sloc := Sloc (Seen);
2222 It1 := Disambiguate (N, I1, I, Typ);
2224 -- Disambiguation has succeeded. Skip the remaining
2227 if It1 /= No_Interp then
2229 Expr_Type := It1.Typ;
2231 while Present (It.Typ) loop
2232 Get_Next_Interp (I, It);
2236 -- Before we issue an ambiguity complaint, check for
2237 -- the case of a subprogram call where at least one
2238 -- of the arguments is Any_Type, and if so, suppress
2239 -- the message, since it is a cascaded error.
2241 if Nkind (N) in N_Subprogram_Call then
2247 A := First_Actual (N);
2248 while Present (A) loop
2251 if Nkind (E) = N_Parameter_Association then
2252 E := Explicit_Actual_Parameter (E);
2255 if Etype (E) = Any_Type then
2256 if Debug_Flag_V then
2257 Write_Str ("Any_Type in call");
2268 elsif Nkind (N) in N_Binary_Op
2269 and then (Etype (Left_Opnd (N)) = Any_Type
2270 or else Etype (Right_Opnd (N)) = Any_Type)
2274 elsif Nkind (N) in N_Unary_Op
2275 and then Etype (Right_Opnd (N)) = Any_Type
2280 -- Not that special case, so issue message using the
2281 -- flag Ambiguous to control printing of the header
2282 -- message only at the start of an ambiguous set.
2284 if not Ambiguous then
2285 if Nkind (N) = N_Function_Call
2286 and then Nkind (Name (N)) = N_Explicit_Dereference
2289 ("ambiguous expression "
2290 & "(cannot resolve indirect call)!", N);
2292 Error_Msg_NE -- CODEFIX
2293 ("ambiguous expression (cannot resolve&)!",
2299 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2301 ("\\possible interpretation (inherited)#!", N);
2303 Error_Msg_N -- CODEFIX
2304 ("\\possible interpretation#!", N);
2307 if Nkind (N) in N_Subprogram_Call
2308 and then Present (Parameter_Associations (N))
2310 Report_Ambiguous_Argument;
2314 Error_Msg_Sloc := Sloc (It.Nam);
2316 -- By default, the error message refers to the candidate
2317 -- interpretation. But if it is a predefined operator, it
2318 -- is implicitly declared at the declaration of the type
2319 -- of the operand. Recover the sloc of that declaration
2320 -- for the error message.
2322 if Nkind (N) in N_Op
2323 and then Scope (It.Nam) = Standard_Standard
2324 and then not Is_Overloaded (Right_Opnd (N))
2325 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2328 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2330 if Comes_From_Source (Err_Type)
2331 and then Present (Parent (Err_Type))
2333 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2336 elsif Nkind (N) in N_Binary_Op
2337 and then Scope (It.Nam) = Standard_Standard
2338 and then not Is_Overloaded (Left_Opnd (N))
2339 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2342 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2344 if Comes_From_Source (Err_Type)
2345 and then Present (Parent (Err_Type))
2347 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2350 -- If this is an indirect call, use the subprogram_type
2351 -- in the message, to have a meaningful location. Also
2352 -- indicate if this is an inherited operation, created
2353 -- by a type declaration.
2355 elsif Nkind (N) = N_Function_Call
2356 and then Nkind (Name (N)) = N_Explicit_Dereference
2357 and then Is_Type (It.Nam)
2361 Sloc (Associated_Node_For_Itype (Err_Type));
2366 if Nkind (N) in N_Op
2367 and then Scope (It.Nam) = Standard_Standard
2368 and then Present (Err_Type)
2370 -- Special-case the message for universal_fixed
2371 -- operators, which are not declared with the type
2372 -- of the operand, but appear forever in Standard.
2374 if It.Typ = Universal_Fixed
2375 and then Scope (It.Nam) = Standard_Standard
2378 ("\\possible interpretation as universal_fixed "
2379 & "operation (RM 4.5.5 (19))", N);
2382 ("\\possible interpretation (predefined)#!", N);
2386 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2389 ("\\possible interpretation (inherited)#!", N);
2391 Error_Msg_N -- CODEFIX
2392 ("\\possible interpretation#!", N);
2398 -- We have a matching interpretation, Expr_Type is the type
2399 -- from this interpretation, and Seen is the entity.
2401 -- For an operator, just set the entity name. The type will be
2402 -- set by the specific operator resolution routine.
2404 if Nkind (N) in N_Op then
2405 Set_Entity (N, Seen);
2406 Generate_Reference (Seen, N);
2408 elsif Nkind (N) = N_Case_Expression then
2409 Set_Etype (N, Expr_Type);
2411 elsif Nkind (N) = N_Character_Literal then
2412 Set_Etype (N, Expr_Type);
2414 elsif Nkind (N) = N_If_Expression then
2415 Set_Etype (N, Expr_Type);
2417 -- AI05-0139-2: Expression is overloaded because type has
2418 -- implicit dereference. If type matches context, no implicit
2419 -- dereference is involved.
2421 elsif Has_Implicit_Dereference (Expr_Type) then
2422 Set_Etype (N, Expr_Type);
2423 Set_Is_Overloaded (N, False);
2426 elsif Is_Overloaded (N)
2427 and then Present (It.Nam)
2428 and then Ekind (It.Nam) = E_Discriminant
2429 and then Has_Implicit_Dereference (It.Nam)
2431 -- If the node is a general indexing, the dereference is
2432 -- is inserted when resolving the rewritten form, else
2435 if Nkind (N) /= N_Indexed_Component
2436 or else No (Generalized_Indexing (N))
2438 Build_Explicit_Dereference (N, It.Nam);
2441 -- For an explicit dereference, attribute reference, range,
2442 -- short-circuit form (which is not an operator node), or call
2443 -- with a name that is an explicit dereference, there is
2444 -- nothing to be done at this point.
2446 elsif Nkind_In (N, N_Explicit_Dereference,
2447 N_Attribute_Reference,
2449 N_Indexed_Component,
2452 N_Selected_Component,
2454 or else Nkind (Name (N)) = N_Explicit_Dereference
2458 -- For procedure or function calls, set the type of the name,
2459 -- and also the entity pointer for the prefix.
2461 elsif Nkind (N) in N_Subprogram_Call
2462 and then Is_Entity_Name (Name (N))
2464 Set_Etype (Name (N), Expr_Type);
2465 Set_Entity (Name (N), Seen);
2466 Generate_Reference (Seen, Name (N));
2468 elsif Nkind (N) = N_Function_Call
2469 and then Nkind (Name (N)) = N_Selected_Component
2471 Set_Etype (Name (N), Expr_Type);
2472 Set_Entity (Selector_Name (Name (N)), Seen);
2473 Generate_Reference (Seen, Selector_Name (Name (N)));
2475 -- For all other cases, just set the type of the Name
2478 Set_Etype (Name (N), Expr_Type);
2485 -- Move to next interpretation
2487 exit Interp_Loop when No (It.Typ);
2489 Get_Next_Interp (I, It);
2490 end loop Interp_Loop;
2493 -- At this stage Found indicates whether or not an acceptable
2494 -- interpretation exists. If not, then we have an error, except that if
2495 -- the context is Any_Type as a result of some other error, then we
2496 -- suppress the error report.
2499 if Typ /= Any_Type then
2501 -- If type we are looking for is Void, then this is the procedure
2502 -- call case, and the error is simply that what we gave is not a
2503 -- procedure name (we think of procedure calls as expressions with
2504 -- types internally, but the user doesn't think of them this way).
2506 if Typ = Standard_Void_Type then
2508 -- Special case message if function used as a procedure
2510 if Nkind (N) = N_Procedure_Call_Statement
2511 and then Is_Entity_Name (Name (N))
2512 and then Ekind (Entity (Name (N))) = E_Function
2515 ("cannot use function & in a procedure call",
2516 Name (N), Entity (Name (N)));
2518 -- Otherwise give general message (not clear what cases this
2519 -- covers, but no harm in providing for them).
2522 Error_Msg_N ("expect procedure name in procedure call", N);
2527 -- Otherwise we do have a subexpression with the wrong type
2529 -- Check for the case of an allocator which uses an access type
2530 -- instead of the designated type. This is a common error and we
2531 -- specialize the message, posting an error on the operand of the
2532 -- allocator, complaining that we expected the designated type of
2535 elsif Nkind (N) = N_Allocator
2536 and then Is_Access_Type (Typ)
2537 and then Is_Access_Type (Etype (N))
2538 and then Designated_Type (Etype (N)) = Typ
2540 Wrong_Type (Expression (N), Designated_Type (Typ));
2543 -- Check for view mismatch on Null in instances, for which the
2544 -- view-swapping mechanism has no identifier.
2546 elsif (In_Instance or else In_Inlined_Body)
2547 and then (Nkind (N) = N_Null)
2548 and then Is_Private_Type (Typ)
2549 and then Is_Access_Type (Full_View (Typ))
2551 Resolve (N, Full_View (Typ));
2555 -- Check for an aggregate. Sometimes we can get bogus aggregates
2556 -- from misuse of parentheses, and we are about to complain about
2557 -- the aggregate without even looking inside it.
2559 -- Instead, if we have an aggregate of type Any_Composite, then
2560 -- analyze and resolve the component fields, and then only issue
2561 -- another message if we get no errors doing this (otherwise
2562 -- assume that the errors in the aggregate caused the problem).
2564 elsif Nkind (N) = N_Aggregate
2565 and then Etype (N) = Any_Composite
2567 -- Disable expansion in any case. If there is a type mismatch
2568 -- it may be fatal to try to expand the aggregate. The flag
2569 -- would otherwise be set to false when the error is posted.
2571 Expander_Active := False;
2574 procedure Check_Aggr (Aggr : Node_Id);
2575 -- Check one aggregate, and set Found to True if we have a
2576 -- definite error in any of its elements
2578 procedure Check_Elmt (Aelmt : Node_Id);
2579 -- Check one element of aggregate and set Found to True if
2580 -- we definitely have an error in the element.
2586 procedure Check_Aggr (Aggr : Node_Id) is
2590 if Present (Expressions (Aggr)) then
2591 Elmt := First (Expressions (Aggr));
2592 while Present (Elmt) loop
2598 if Present (Component_Associations (Aggr)) then
2599 Elmt := First (Component_Associations (Aggr));
2600 while Present (Elmt) loop
2602 -- If this is a default-initialized component, then
2603 -- there is nothing to check. The box will be
2604 -- replaced by the appropriate call during late
2607 if not Box_Present (Elmt) then
2608 Check_Elmt (Expression (Elmt));
2620 procedure Check_Elmt (Aelmt : Node_Id) is
2622 -- If we have a nested aggregate, go inside it (to
2623 -- attempt a naked analyze-resolve of the aggregate can
2624 -- cause undesirable cascaded errors). Do not resolve
2625 -- expression if it needs a type from context, as for
2626 -- integer * fixed expression.
2628 if Nkind (Aelmt) = N_Aggregate then
2634 if not Is_Overloaded (Aelmt)
2635 and then Etype (Aelmt) /= Any_Fixed
2640 if Etype (Aelmt) = Any_Type then
2651 -- Looks like we have a type error, but check for special case
2652 -- of Address wanted, integer found, with the configuration pragma
2653 -- Allow_Integer_Address active. If we have this case, introduce
2654 -- an unchecked conversion to allow the integer expression to be
2655 -- treated as an Address. The reverse case of integer wanted,
2656 -- Address found, is treated in an analogous manner.
2658 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2659 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2660 Analyze_And_Resolve (N, Typ);
2664 -- That special Allow_Integer_Address check did not appply, so we
2665 -- have a real type error. If an error message was issued already,
2666 -- Found got reset to True, so if it's still False, issue standard
2667 -- Wrong_Type message.
2670 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2672 Subp_Name : Node_Id;
2675 if Is_Entity_Name (Name (N)) then
2676 Subp_Name := Name (N);
2678 elsif Nkind (Name (N)) = N_Selected_Component then
2680 -- Protected operation: retrieve operation name
2682 Subp_Name := Selector_Name (Name (N));
2685 raise Program_Error;
2688 Error_Msg_Node_2 := Typ;
2690 ("no visible interpretation of& "
2691 & "matches expected type&", N, Subp_Name);
2694 if All_Errors_Mode then
2696 Index : Interp_Index;
2700 Error_Msg_N ("\\possible interpretations:", N);
2702 Get_First_Interp (Name (N), Index, It);
2703 while Present (It.Nam) loop
2704 Error_Msg_Sloc := Sloc (It.Nam);
2705 Error_Msg_Node_2 := It.Nam;
2707 ("\\ type& for & declared#", N, It.Typ);
2708 Get_Next_Interp (Index, It);
2713 Error_Msg_N ("\use -gnatf for details", N);
2717 Wrong_Type (N, Typ);
2725 -- Test if we have more than one interpretation for the context
2727 elsif Ambiguous then
2731 -- Only one intepretation
2734 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2735 -- the "+" on T is abstract, and the operands are of universal type,
2736 -- the above code will have (incorrectly) resolved the "+" to the
2737 -- universal one in Standard. Therefore check for this case and give
2738 -- an error. We can't do this earlier, because it would cause legal
2739 -- cases to get errors (when some other type has an abstract "+").
2741 if Ada_Version >= Ada_2005
2742 and then Nkind (N) in N_Op
2743 and then Is_Overloaded (N)
2744 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2746 Get_First_Interp (N, I, It);
2747 while Present (It.Typ) loop
2748 if Present (It.Abstract_Op) and then
2749 Etype (It.Abstract_Op) = Typ
2752 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2756 Get_Next_Interp (I, It);
2760 -- Here we have an acceptable interpretation for the context
2762 -- Propagate type information and normalize tree for various
2763 -- predefined operations. If the context only imposes a class of
2764 -- types, rather than a specific type, propagate the actual type
2767 if Typ = Any_Integer or else
2768 Typ = Any_Boolean or else
2769 Typ = Any_Modular or else
2770 Typ = Any_Real or else
2773 Ctx_Type := Expr_Type;
2775 -- Any_Fixed is legal in a real context only if a specific fixed-
2776 -- point type is imposed. If Norman Cohen can be confused by this,
2777 -- it deserves a separate message.
2780 and then Expr_Type = Any_Fixed
2782 Error_Msg_N ("illegal context for mixed mode operation", N);
2783 Set_Etype (N, Universal_Real);
2784 Ctx_Type := Universal_Real;
2788 -- A user-defined operator is transformed into a function call at
2789 -- this point, so that further processing knows that operators are
2790 -- really operators (i.e. are predefined operators). User-defined
2791 -- operators that are intrinsic are just renamings of the predefined
2792 -- ones, and need not be turned into calls either, but if they rename
2793 -- a different operator, we must transform the node accordingly.
2794 -- Instantiations of Unchecked_Conversion are intrinsic but are
2795 -- treated as functions, even if given an operator designator.
2797 if Nkind (N) in N_Op
2798 and then Present (Entity (N))
2799 and then Ekind (Entity (N)) /= E_Operator
2802 if not Is_Predefined_Op (Entity (N)) then
2803 Rewrite_Operator_As_Call (N, Entity (N));
2805 elsif Present (Alias (Entity (N)))
2807 Nkind (Parent (Parent (Entity (N)))) =
2808 N_Subprogram_Renaming_Declaration
2810 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2812 -- If the node is rewritten, it will be fully resolved in
2813 -- Rewrite_Renamed_Operator.
2815 if Analyzed (N) then
2821 case N_Subexpr'(Nkind (N)) is
2823 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2825 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2827 when N_Short_Circuit
2828 => Resolve_Short_Circuit (N, Ctx_Type);
2830 when N_Attribute_Reference
2831 => Resolve_Attribute (N, Ctx_Type);
2833 when N_Case_Expression
2834 => Resolve_Case_Expression (N, Ctx_Type);
2836 when N_Character_Literal
2837 => Resolve_Character_Literal (N, Ctx_Type);
2839 when N_Expanded_Name
2840 => Resolve_Entity_Name (N, Ctx_Type);
2842 when N_Explicit_Dereference
2843 => Resolve_Explicit_Dereference (N, Ctx_Type);
2845 when N_Expression_With_Actions
2846 => Resolve_Expression_With_Actions (N, Ctx_Type);
2848 when N_Extension_Aggregate
2849 => Resolve_Extension_Aggregate (N, Ctx_Type);
2851 when N_Function_Call
2852 => Resolve_Call (N, Ctx_Type);
2855 => Resolve_Entity_Name (N, Ctx_Type);
2857 when N_If_Expression
2858 => Resolve_If_Expression (N, Ctx_Type);
2860 when N_Indexed_Component
2861 => Resolve_Indexed_Component (N, Ctx_Type);
2863 when N_Integer_Literal
2864 => Resolve_Integer_Literal (N, Ctx_Type);
2866 when N_Membership_Test
2867 => Resolve_Membership_Op (N, Ctx_Type);
2869 when N_Null => Resolve_Null (N, Ctx_Type);
2871 when N_Op_And | N_Op_Or | N_Op_Xor
2872 => Resolve_Logical_Op (N, Ctx_Type);
2874 when N_Op_Eq | N_Op_Ne
2875 => Resolve_Equality_Op (N, Ctx_Type);
2877 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2878 => Resolve_Comparison_Op (N, Ctx_Type);
2880 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2882 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2883 N_Op_Divide | N_Op_Mod | N_Op_Rem
2885 => Resolve_Arithmetic_Op (N, Ctx_Type);
2887 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2889 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2891 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2892 => Resolve_Unary_Op (N, Ctx_Type);
2894 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2896 when N_Procedure_Call_Statement
2897 => Resolve_Call (N, Ctx_Type);
2899 when N_Operator_Symbol
2900 => Resolve_Operator_Symbol (N, Ctx_Type);
2902 when N_Qualified_Expression
2903 => Resolve_Qualified_Expression (N, Ctx_Type);
2905 -- Why is the following null, needs a comment ???
2907 when N_Quantified_Expression
2910 when N_Raise_Expression
2911 => Resolve_Raise_Expression (N, Ctx_Type);
2913 when N_Raise_xxx_Error
2914 => Set_Etype (N, Ctx_Type);
2916 when N_Range => Resolve_Range (N, Ctx_Type);
2919 => Resolve_Real_Literal (N, Ctx_Type);
2921 when N_Reference => Resolve_Reference (N, Ctx_Type);
2923 when N_Selected_Component
2924 => Resolve_Selected_Component (N, Ctx_Type);
2926 when N_Slice => Resolve_Slice (N, Ctx_Type);
2928 when N_String_Literal
2929 => Resolve_String_Literal (N, Ctx_Type);
2931 when N_Type_Conversion
2932 => Resolve_Type_Conversion (N, Ctx_Type);
2934 when N_Unchecked_Expression =>
2935 Resolve_Unchecked_Expression (N, Ctx_Type);
2937 when N_Unchecked_Type_Conversion =>
2938 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2941 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2942 -- expression of an anonymous access type that occurs in the context
2943 -- of a named general access type, except when the expression is that
2944 -- of a membership test. This ensures proper legality checking in
2945 -- terms of allowed conversions (expressions that would be illegal to
2946 -- convert implicitly are allowed in membership tests).
2948 if Ada_Version >= Ada_2012
2949 and then Ekind (Ctx_Type) = E_General_Access_Type
2950 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2951 and then Nkind (Parent (N)) not in N_Membership_Test
2953 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2954 Analyze_And_Resolve (N, Ctx_Type);
2957 -- If the subexpression was replaced by a non-subexpression, then
2958 -- all we do is to expand it. The only legitimate case we know of
2959 -- is converting procedure call statement to entry call statements,
2960 -- but there may be others, so we are making this test general.
2962 if Nkind (N) not in N_Subexpr then
2963 Debug_A_Exit ("resolving ", N, " (done)");
2968 -- The expression is definitely NOT overloaded at this point, so
2969 -- we reset the Is_Overloaded flag to avoid any confusion when
2970 -- reanalyzing the node.
2972 Set_Is_Overloaded (N, False);
2974 -- Freeze expression type, entity if it is a name, and designated
2975 -- type if it is an allocator (RM 13.14(10,11,13)).
2977 -- Now that the resolution of the type of the node is complete, and
2978 -- we did not detect an error, we can expand this node. We skip the
2979 -- expand call if we are in a default expression, see section
2980 -- "Handling of Default Expressions" in Sem spec.
2982 Debug_A_Exit ("resolving ", N, " (done)");
2984 -- We unconditionally freeze the expression, even if we are in
2985 -- default expression mode (the Freeze_Expression routine tests this
2986 -- flag and only freezes static types if it is set).
2988 -- Ada 2012 (AI05-177): The declaration of an expression function
2989 -- does not cause freezing, but we never reach here in that case.
2990 -- Here we are resolving the corresponding expanded body, so we do
2991 -- need to perform normal freezing.
2993 Freeze_Expression (N);
2995 -- Now we can do the expansion
3005 -- Version with check(s) suppressed
3007 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3009 if Suppress = All_Checks then
3011 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3013 Scope_Suppress.Suppress := (others => True);
3015 Scope_Suppress.Suppress := Sva;
3020 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3022 Scope_Suppress.Suppress (Suppress) := True;
3024 Scope_Suppress.Suppress (Suppress) := Svg;
3033 -- Version with implicit type
3035 procedure Resolve (N : Node_Id) is
3037 Resolve (N, Etype (N));
3040 ---------------------
3041 -- Resolve_Actuals --
3042 ---------------------
3044 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3045 Loc : constant Source_Ptr := Sloc (N);
3051 Prev : Node_Id := Empty;
3055 Real_Subp : Entity_Id;
3056 -- If the subprogram being called is an overridden operation,
3057 -- Real_Subp is the subprogram that will be called. It may have
3058 -- different formal names than the overridden operation, so after
3059 -- actual is resolved, the name of the actual in a named association
3060 -- must carry the name of the actual of the subprogram being called.
3062 procedure Check_Aliased_Parameter;
3063 -- Check rules on aliased parameters and related accessibility rules
3064 -- in (RM 3.10.2 (10.2-10.4)).
3066 procedure Check_Argument_Order;
3067 -- Performs a check for the case where the actuals are all simple
3068 -- identifiers that correspond to the formal names, but in the wrong
3069 -- order, which is considered suspicious and cause for a warning.
3071 procedure Check_Prefixed_Call;
3072 -- If the original node is an overloaded call in prefix notation,
3073 -- insert an 'Access or a dereference as needed over the first actual.
3074 -- Try_Object_Operation has already verified that there is a valid
3075 -- interpretation, but the form of the actual can only be determined
3076 -- once the primitive operation is identified.
3078 procedure Insert_Default;
3079 -- If the actual is missing in a call, insert in the actuals list
3080 -- an instance of the default expression. The insertion is always
3081 -- a named association.
3083 procedure Property_Error
3086 Prop_Nam : Name_Id);
3087 -- Emit an error concerning variable Var with entity Var_Id that has
3088 -- enabled property Prop_Nam when it acts as an actual parameter in a
3089 -- call and the corresponding formal parameter is of mode IN.
3091 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3092 -- Check whether T1 and T2, or their full views, are derived from a
3093 -- common type. Used to enforce the restrictions on array conversions
3096 function Static_Concatenation (N : Node_Id) return Boolean;
3097 -- Predicate to determine whether an actual that is a concatenation
3098 -- will be evaluated statically and does not need a transient scope.
3099 -- This must be determined before the actual is resolved and expanded
3100 -- because if needed the transient scope must be introduced earlier.
3102 -----------------------------
3103 -- Check_Aliased_Parameter --
3104 -----------------------------
3106 procedure Check_Aliased_Parameter is
3107 Nominal_Subt : Entity_Id;
3110 if Is_Aliased (F) then
3111 if Is_Tagged_Type (A_Typ) then
3114 elsif Is_Aliased_View (A) then
3115 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3116 Nominal_Subt := Base_Type (A_Typ);
3118 Nominal_Subt := A_Typ;
3121 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3124 -- In a generic body assume the worst for generic formals:
3125 -- they can have a constrained partial view (AI05-041).
3127 elsif Has_Discriminants (F_Typ)
3128 and then not Is_Constrained (F_Typ)
3129 and then not Has_Constrained_Partial_View (F_Typ)
3130 and then not Is_Generic_Type (F_Typ)
3135 Error_Msg_NE ("untagged actual does not match "
3136 & "aliased formal&", A, F);
3140 Error_Msg_NE ("actual for aliased formal& must be "
3141 & "aliased object", A, F);
3144 if Ekind (Nam) = E_Procedure then
3147 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3148 if Nkind (Parent (N)) = N_Type_Conversion
3149 and then Type_Access_Level (Etype (Parent (N))) <
3150 Object_Access_Level (A)
3152 Error_Msg_N ("aliased actual has wrong accessibility", A);
3155 elsif Nkind (Parent (N)) = N_Qualified_Expression
3156 and then Nkind (Parent (Parent (N))) = N_Allocator
3157 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3158 Object_Access_Level (A)
3161 ("aliased actual in allocator has wrong accessibility", A);
3164 end Check_Aliased_Parameter;
3166 --------------------------
3167 -- Check_Argument_Order --
3168 --------------------------
3170 procedure Check_Argument_Order is
3172 -- Nothing to do if no parameters, or original node is neither a
3173 -- function call nor a procedure call statement (happens in the
3174 -- operator-transformed-to-function call case), or the call does
3175 -- not come from source, or this warning is off.
3177 if not Warn_On_Parameter_Order
3178 or else No (Parameter_Associations (N))
3179 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3180 or else not Comes_From_Source (N)
3186 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3189 -- Nothing to do if only one parameter
3195 -- Here if at least two arguments
3198 Actuals : array (1 .. Nargs) of Node_Id;
3202 Wrong_Order : Boolean := False;
3203 -- Set True if an out of order case is found
3206 -- Collect identifier names of actuals, fail if any actual is
3207 -- not a simple identifier, and record max length of name.
3209 Actual := First (Parameter_Associations (N));
3210 for J in Actuals'Range loop
3211 if Nkind (Actual) /= N_Identifier then
3214 Actuals (J) := Actual;
3219 -- If we got this far, all actuals are identifiers and the list
3220 -- of their names is stored in the Actuals array.
3222 Formal := First_Formal (Nam);
3223 for J in Actuals'Range loop
3225 -- If we ran out of formals, that's odd, probably an error
3226 -- which will be detected elsewhere, but abandon the search.
3232 -- If name matches and is in order OK
3234 if Chars (Formal) = Chars (Actuals (J)) then
3238 -- If no match, see if it is elsewhere in list and if so
3239 -- flag potential wrong order if type is compatible.
3241 for K in Actuals'Range loop
3242 if Chars (Formal) = Chars (Actuals (K))
3244 Has_Compatible_Type (Actuals (K), Etype (Formal))
3246 Wrong_Order := True;
3256 <<Continue>> Next_Formal (Formal);
3259 -- If Formals left over, also probably an error, skip warning
3261 if Present (Formal) then
3265 -- Here we give the warning if something was out of order
3269 ("?P?actuals for this call may be in wrong order", N);
3273 end Check_Argument_Order;
3275 -------------------------
3276 -- Check_Prefixed_Call --
3277 -------------------------
3279 procedure Check_Prefixed_Call is
3280 Act : constant Node_Id := First_Actual (N);
3281 A_Type : constant Entity_Id := Etype (Act);
3282 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3283 Orig : constant Node_Id := Original_Node (N);
3287 -- Check whether the call is a prefixed call, with or without
3288 -- additional actuals.
3290 if Nkind (Orig) = N_Selected_Component
3292 (Nkind (Orig) = N_Indexed_Component
3293 and then Nkind (Prefix (Orig)) = N_Selected_Component
3294 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3295 and then Is_Entity_Name (Act)
3296 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3298 if Is_Access_Type (A_Type)
3299 and then not Is_Access_Type (F_Type)
3301 -- Introduce dereference on object in prefix
3304 Make_Explicit_Dereference (Sloc (Act),
3305 Prefix => Relocate_Node (Act));
3306 Rewrite (Act, New_A);
3309 elsif Is_Access_Type (F_Type)
3310 and then not Is_Access_Type (A_Type)
3312 -- Introduce an implicit 'Access in prefix
3314 if not Is_Aliased_View (Act) then
3316 ("object in prefixed call to& must be aliased "
3317 & "(RM 4.1.3 (13 1/2))",
3322 Make_Attribute_Reference (Loc,
3323 Attribute_Name => Name_Access,
3324 Prefix => Relocate_Node (Act)));
3329 end Check_Prefixed_Call;
3331 --------------------
3332 -- Insert_Default --
3333 --------------------
3335 procedure Insert_Default is
3340 -- Missing argument in call, nothing to insert
3342 if No (Default_Value (F)) then
3346 -- Note that we do a full New_Copy_Tree, so that any associated
3347 -- Itypes are properly copied. This may not be needed any more,
3348 -- but it does no harm as a safety measure. Defaults of a generic
3349 -- formal may be out of bounds of the corresponding actual (see
3350 -- cc1311b) and an additional check may be required.
3355 New_Scope => Current_Scope,
3358 if Is_Concurrent_Type (Scope (Nam))
3359 and then Has_Discriminants (Scope (Nam))
3361 Replace_Actual_Discriminants (N, Actval);
3364 if Is_Overloadable (Nam)
3365 and then Present (Alias (Nam))
3367 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3368 and then not Is_Tagged_Type (Etype (F))
3370 -- If default is a real literal, do not introduce a
3371 -- conversion whose effect may depend on the run-time
3372 -- size of universal real.
3374 if Nkind (Actval) = N_Real_Literal then
3375 Set_Etype (Actval, Base_Type (Etype (F)));
3377 Actval := Unchecked_Convert_To (Etype (F), Actval);
3381 if Is_Scalar_Type (Etype (F)) then
3382 Enable_Range_Check (Actval);
3385 Set_Parent (Actval, N);
3387 -- Resolve aggregates with their base type, to avoid scope
3388 -- anomalies: the subtype was first built in the subprogram
3389 -- declaration, and the current call may be nested.
3391 if Nkind (Actval) = N_Aggregate then
3392 Analyze_And_Resolve (Actval, Etype (F));
3394 Analyze_And_Resolve (Actval, Etype (Actval));
3398 Set_Parent (Actval, N);
3400 -- See note above concerning aggregates
3402 if Nkind (Actval) = N_Aggregate
3403 and then Has_Discriminants (Etype (Actval))
3405 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3407 -- Resolve entities with their own type, which may differ from
3408 -- the type of a reference in a generic context (the view
3409 -- swapping mechanism did not anticipate the re-analysis of
3410 -- default values in calls).
3412 elsif Is_Entity_Name (Actval) then
3413 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3416 Analyze_And_Resolve (Actval, Etype (Actval));
3420 -- If default is a tag indeterminate function call, propagate tag
3421 -- to obtain proper dispatching.
3423 if Is_Controlling_Formal (F)
3424 and then Nkind (Default_Value (F)) = N_Function_Call
3426 Set_Is_Controlling_Actual (Actval);
3431 -- If the default expression raises constraint error, then just
3432 -- silently replace it with an N_Raise_Constraint_Error node, since
3433 -- we already gave the warning on the subprogram spec. If node is
3434 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3435 -- the warnings removal machinery.
3437 if Raises_Constraint_Error (Actval)
3438 and then Nkind (Actval) /= N_Raise_Constraint_Error
3441 Make_Raise_Constraint_Error (Loc,
3442 Reason => CE_Range_Check_Failed));
3443 Set_Raises_Constraint_Error (Actval);
3444 Set_Etype (Actval, Etype (F));
3448 Make_Parameter_Association (Loc,
3449 Explicit_Actual_Parameter => Actval,
3450 Selector_Name => Make_Identifier (Loc, Chars (F)));
3452 -- Case of insertion is first named actual
3454 if No (Prev) or else
3455 Nkind (Parent (Prev)) /= N_Parameter_Association
3457 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3458 Set_First_Named_Actual (N, Actval);
3461 if No (Parameter_Associations (N)) then
3462 Set_Parameter_Associations (N, New_List (Assoc));
3464 Append (Assoc, Parameter_Associations (N));
3468 Insert_After (Prev, Assoc);
3471 -- Case of insertion is not first named actual
3474 Set_Next_Named_Actual
3475 (Assoc, Next_Named_Actual (Parent (Prev)));
3476 Set_Next_Named_Actual (Parent (Prev), Actval);
3477 Append (Assoc, Parameter_Associations (N));
3480 Mark_Rewrite_Insertion (Assoc);
3481 Mark_Rewrite_Insertion (Actval);
3486 --------------------
3487 -- Property_Error --
3488 --------------------
3490 procedure Property_Error
3496 Error_Msg_Name_1 := Prop_Nam;
3498 ("external variable & with enabled property % cannot appear as "
3499 & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id);
3500 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3507 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3508 FT1 : Entity_Id := T1;
3509 FT2 : Entity_Id := T2;
3512 if Is_Private_Type (T1)
3513 and then Present (Full_View (T1))
3515 FT1 := Full_View (T1);
3518 if Is_Private_Type (T2)
3519 and then Present (Full_View (T2))
3521 FT2 := Full_View (T2);
3524 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3527 --------------------------
3528 -- Static_Concatenation --
3529 --------------------------
3531 function Static_Concatenation (N : Node_Id) return Boolean is
3534 when N_String_Literal =>
3539 -- Concatenation is static when both operands are static and
3540 -- the concatenation operator is a predefined one.
3542 return Scope (Entity (N)) = Standard_Standard
3544 Static_Concatenation (Left_Opnd (N))
3546 Static_Concatenation (Right_Opnd (N));
3549 if Is_Entity_Name (N) then
3551 Ent : constant Entity_Id := Entity (N);
3553 return Ekind (Ent) = E_Constant
3554 and then Present (Constant_Value (Ent))
3556 Is_OK_Static_Expression (Constant_Value (Ent));
3563 end Static_Concatenation;
3565 -- Start of processing for Resolve_Actuals
3568 Check_Argument_Order;
3569 Check_Function_Writable_Actuals (N);
3571 if Is_Overloadable (Nam)
3572 and then Is_Inherited_Operation (Nam)
3573 and then Present (Alias (Nam))
3574 and then Present (Overridden_Operation (Alias (Nam)))
3576 Real_Subp := Alias (Nam);
3581 if Present (First_Actual (N)) then
3582 Check_Prefixed_Call;
3585 A := First_Actual (N);
3586 F := First_Formal (Nam);
3588 if Present (Real_Subp) then
3589 Real_F := First_Formal (Real_Subp);
3592 while Present (F) loop
3593 if No (A) and then Needs_No_Actuals (Nam) then
3596 -- If we have an error in any actual or formal, indicated by a type
3597 -- of Any_Type, then abandon resolution attempt, and set result type
3598 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3599 -- type is imposed from context.
3601 elsif (Present (A) and then Etype (A) = Any_Type)
3602 or else Etype (F) = Any_Type
3604 if Nkind (A) /= N_Raise_Expression then
3605 Set_Etype (N, Any_Type);
3610 -- Case where actual is present
3612 -- If the actual is an entity, generate a reference to it now. We
3613 -- do this before the actual is resolved, because a formal of some
3614 -- protected subprogram, or a task discriminant, will be rewritten
3615 -- during expansion, and the source entity reference may be lost.
3618 and then Is_Entity_Name (A)
3619 and then Comes_From_Source (N)
3621 Orig_A := Entity (A);
3623 if Present (Orig_A) then
3624 if Is_Formal (Orig_A)
3625 and then Ekind (F) /= E_In_Parameter
3627 Generate_Reference (Orig_A, A, 'm');
3629 elsif not Is_Overloaded (A) then
3630 if Ekind (F) /= E_Out_Parameter then
3631 Generate_Reference (Orig_A, A);
3633 -- RM 6.4.1(12): For an out parameter that is passed by
3634 -- copy, the formal parameter object is created, and:
3636 -- * For an access type, the formal parameter is initialized
3637 -- from the value of the actual, without checking that the
3638 -- value satisfies any constraint, any predicate, or any
3639 -- exclusion of the null value.
3641 -- * For a scalar type that has the Default_Value aspect
3642 -- specified, the formal parameter is initialized from the
3643 -- value of the actual, without checking that the value
3644 -- satisfies any constraint or any predicate.
3645 -- I do not understand why this case is included??? this is
3646 -- not a case where an OUT parameter is treated as IN OUT.
3648 -- * For a composite type with discriminants or that has
3649 -- implicit initial values for any subcomponents, the
3650 -- behavior is as for an in out parameter passed by copy.
3652 -- Hence for these cases we generate the read reference now
3653 -- (the write reference will be generated later by
3654 -- Note_Possible_Modification).
3656 elsif Is_By_Copy_Type (Etype (F))
3658 (Is_Access_Type (Etype (F))
3660 (Is_Scalar_Type (Etype (F))
3662 Present (Default_Aspect_Value (Etype (F))))
3664 (Is_Composite_Type (Etype (F))
3665 and then (Has_Discriminants (Etype (F))
3666 or else Is_Partially_Initialized_Type
3669 Generate_Reference (Orig_A, A);
3676 and then (Nkind (Parent (A)) /= N_Parameter_Association
3677 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3679 -- If style checking mode on, check match of formal name
3682 if Nkind (Parent (A)) = N_Parameter_Association then
3683 Check_Identifier (Selector_Name (Parent (A)), F);
3687 -- If the formal is Out or In_Out, do not resolve and expand the
3688 -- conversion, because it is subsequently expanded into explicit
3689 -- temporaries and assignments. However, the object of the
3690 -- conversion can be resolved. An exception is the case of tagged
3691 -- type conversion with a class-wide actual. In that case we want
3692 -- the tag check to occur and no temporary will be needed (no
3693 -- representation change can occur) and the parameter is passed by
3694 -- reference, so we go ahead and resolve the type conversion.
3695 -- Another exception is the case of reference to component or
3696 -- subcomponent of a bit-packed array, in which case we want to
3697 -- defer expansion to the point the in and out assignments are
3700 if Ekind (F) /= E_In_Parameter
3701 and then Nkind (A) = N_Type_Conversion
3702 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3704 if Ekind (F) = E_In_Out_Parameter
3705 and then Is_Array_Type (Etype (F))
3707 -- In a view conversion, the conversion must be legal in
3708 -- both directions, and thus both component types must be
3709 -- aliased, or neither (4.6 (8)).
3711 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3712 -- the privacy requirement should not apply to generic
3713 -- types, and should be checked in an instance. ARG query
3716 if Has_Aliased_Components (Etype (Expression (A))) /=
3717 Has_Aliased_Components (Etype (F))
3720 ("both component types in a view conversion must be"
3721 & " aliased, or neither", A);
3723 -- Comment here??? what set of cases???
3726 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3728 -- Check view conv between unrelated by ref array types
3730 if Is_By_Reference_Type (Etype (F))
3731 or else Is_By_Reference_Type (Etype (Expression (A)))
3734 ("view conversion between unrelated by reference "
3735 & "array types not allowed (\'A'I-00246)", A);
3737 -- In Ada 2005 mode, check view conversion component
3738 -- type cannot be private, tagged, or volatile. Note
3739 -- that we only apply this to source conversions. The
3740 -- generated code can contain conversions which are
3741 -- not subject to this test, and we cannot extract the
3742 -- component type in such cases since it is not present.
3744 elsif Comes_From_Source (A)
3745 and then Ada_Version >= Ada_2005
3748 Comp_Type : constant Entity_Id :=
3750 (Etype (Expression (A)));
3752 if (Is_Private_Type (Comp_Type)
3753 and then not Is_Generic_Type (Comp_Type))
3754 or else Is_Tagged_Type (Comp_Type)
3755 or else Is_Volatile (Comp_Type)
3758 ("component type of a view conversion cannot"
3759 & " be private, tagged, or volatile"
3768 -- Resolve expression if conversion is all OK
3770 if (Conversion_OK (A)
3771 or else Valid_Conversion (A, Etype (A), Expression (A)))
3772 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3774 Resolve (Expression (A));
3777 -- If the actual is a function call that returns a limited
3778 -- unconstrained object that needs finalization, create a
3779 -- transient scope for it, so that it can receive the proper
3780 -- finalization list.
3782 elsif Nkind (A) = N_Function_Call
3783 and then Is_Limited_Record (Etype (F))
3784 and then not Is_Constrained (Etype (F))
3785 and then Expander_Active
3786 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3788 Establish_Transient_Scope (A, Sec_Stack => False);
3789 Resolve (A, Etype (F));
3791 -- A small optimization: if one of the actuals is a concatenation
3792 -- create a block around a procedure call to recover stack space.
3793 -- This alleviates stack usage when several procedure calls in
3794 -- the same statement list use concatenation. We do not perform
3795 -- this wrapping for code statements, where the argument is a
3796 -- static string, and we want to preserve warnings involving
3797 -- sequences of such statements.
3799 elsif Nkind (A) = N_Op_Concat
3800 and then Nkind (N) = N_Procedure_Call_Statement
3801 and then Expander_Active
3803 not (Is_Intrinsic_Subprogram (Nam)
3804 and then Chars (Nam) = Name_Asm)
3805 and then not Static_Concatenation (A)
3807 Establish_Transient_Scope (A, Sec_Stack => False);
3808 Resolve (A, Etype (F));
3811 if Nkind (A) = N_Type_Conversion
3812 and then Is_Array_Type (Etype (F))
3813 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3815 (Is_Limited_Type (Etype (F))
3816 or else Is_Limited_Type (Etype (Expression (A))))
3819 ("conversion between unrelated limited array types "
3820 & "not allowed ('A'I-00246)", A);
3822 if Is_Limited_Type (Etype (F)) then
3823 Explain_Limited_Type (Etype (F), A);
3826 if Is_Limited_Type (Etype (Expression (A))) then
3827 Explain_Limited_Type (Etype (Expression (A)), A);
3831 -- (Ada 2005: AI-251): If the actual is an allocator whose
3832 -- directly designated type is a class-wide interface, we build
3833 -- an anonymous access type to use it as the type of the
3834 -- allocator. Later, when the subprogram call is expanded, if
3835 -- the interface has a secondary dispatch table the expander
3836 -- will add a type conversion to force the correct displacement
3839 if Nkind (A) = N_Allocator then
3841 DDT : constant Entity_Id :=
3842 Directly_Designated_Type (Base_Type (Etype (F)));
3844 New_Itype : Entity_Id;
3847 if Is_Class_Wide_Type (DDT)
3848 and then Is_Interface (DDT)
3850 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3851 Set_Etype (New_Itype, Etype (A));
3852 Set_Directly_Designated_Type
3853 (New_Itype, Directly_Designated_Type (Etype (A)));
3854 Set_Etype (A, New_Itype);
3857 -- Ada 2005, AI-162:If the actual is an allocator, the
3858 -- innermost enclosing statement is the master of the
3859 -- created object. This needs to be done with expansion
3860 -- enabled only, otherwise the transient scope will not
3861 -- be removed in the expansion of the wrapped construct.
3863 if (Is_Controlled (DDT) or else Has_Task (DDT))
3864 and then Expander_Active
3866 Establish_Transient_Scope (A, Sec_Stack => False);
3870 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3871 Check_Restriction (No_Access_Parameter_Allocators, A);
3875 -- (Ada 2005): The call may be to a primitive operation of a
3876 -- tagged synchronized type, declared outside of the type. In
3877 -- this case the controlling actual must be converted to its
3878 -- corresponding record type, which is the formal type. The
3879 -- actual may be a subtype, either because of a constraint or
3880 -- because it is a generic actual, so use base type to locate
3883 F_Typ := Base_Type (Etype (F));
3885 if Is_Tagged_Type (F_Typ)
3886 and then (Is_Concurrent_Type (F_Typ)
3887 or else Is_Concurrent_Record_Type (F_Typ))
3889 -- If the actual is overloaded, look for an interpretation
3890 -- that has a synchronized type.
3892 if not Is_Overloaded (A) then
3893 A_Typ := Base_Type (Etype (A));
3897 Index : Interp_Index;
3901 Get_First_Interp (A, Index, It);
3902 while Present (It.Typ) loop
3903 if Is_Concurrent_Type (It.Typ)
3904 or else Is_Concurrent_Record_Type (It.Typ)
3906 A_Typ := Base_Type (It.Typ);
3910 Get_Next_Interp (Index, It);
3916 Full_A_Typ : Entity_Id;
3919 if Present (Full_View (A_Typ)) then
3920 Full_A_Typ := Base_Type (Full_View (A_Typ));
3922 Full_A_Typ := A_Typ;
3925 -- Tagged synchronized type (case 1): the actual is a
3928 if Is_Concurrent_Type (A_Typ)
3929 and then Corresponding_Record_Type (A_Typ) = F_Typ
3932 Unchecked_Convert_To
3933 (Corresponding_Record_Type (A_Typ), A));
3934 Resolve (A, Etype (F));
3936 -- Tagged synchronized type (case 2): the formal is a
3939 elsif Ekind (Full_A_Typ) = E_Record_Type
3941 (Corresponding_Concurrent_Type (Full_A_Typ))
3942 and then Is_Concurrent_Type (F_Typ)
3943 and then Present (Corresponding_Record_Type (F_Typ))
3944 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3946 Resolve (A, Corresponding_Record_Type (F_Typ));
3951 Resolve (A, Etype (F));
3955 -- Not a synchronized operation
3958 Resolve (A, Etype (F));
3965 -- An actual cannot be an untagged formal incomplete type
3967 if Ekind (A_Typ) = E_Incomplete_Type
3968 and then not Is_Tagged_Type (A_Typ)
3969 and then Is_Generic_Type (A_Typ)
3972 ("invalid use of untagged formal incomplete type", A);
3975 if Comes_From_Source (Original_Node (N))
3976 and then Nkind_In (Original_Node (N), N_Function_Call,
3977 N_Procedure_Call_Statement)
3979 -- In formal mode, check that actual parameters matching
3980 -- formals of tagged types are objects (or ancestor type
3981 -- conversions of objects), not general expressions.
3983 if Is_Actual_Tagged_Parameter (A) then
3984 if Is_SPARK_05_Object_Reference (A) then
3987 elsif Nkind (A) = N_Type_Conversion then
3989 Operand : constant Node_Id := Expression (A);
3990 Operand_Typ : constant Entity_Id := Etype (Operand);
3991 Target_Typ : constant Entity_Id := A_Typ;
3994 if not Is_SPARK_05_Object_Reference (Operand) then
3995 Check_SPARK_05_Restriction
3996 ("object required", Operand);
3998 -- In formal mode, the only view conversions are those
3999 -- involving ancestor conversion of an extended type.
4002 (Is_Tagged_Type (Target_Typ)
4003 and then not Is_Class_Wide_Type (Target_Typ)
4004 and then Is_Tagged_Type (Operand_Typ)
4005 and then not Is_Class_Wide_Type (Operand_Typ)
4006 and then Is_Ancestor (Target_Typ, Operand_Typ))
4009 (F, E_Out_Parameter, E_In_Out_Parameter)
4011 Check_SPARK_05_Restriction
4012 ("ancestor conversion is the only permitted "
4013 & "view conversion", A);
4015 Check_SPARK_05_Restriction
4016 ("ancestor conversion required", A);
4025 Check_SPARK_05_Restriction ("object required", A);
4028 -- In formal mode, the only view conversions are those
4029 -- involving ancestor conversion of an extended type.
4031 elsif Nkind (A) = N_Type_Conversion
4032 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4034 Check_SPARK_05_Restriction
4035 ("ancestor conversion is the only permitted view "
4040 -- has warnings suppressed, then we reset Never_Set_In_Source for
4041 -- the calling entity. The reason for this is to catch cases like
4042 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4043 -- uses trickery to modify an IN parameter.
4045 if Ekind (F) = E_In_Parameter
4046 and then Is_Entity_Name (A)
4047 and then Present (Entity (A))
4048 and then Ekind (Entity (A)) = E_Variable
4049 and then Has_Warnings_Off (F_Typ)
4051 Set_Never_Set_In_Source (Entity (A), False);
4054 -- Perform error checks for IN and IN OUT parameters
4056 if Ekind (F) /= E_Out_Parameter then
4058 -- Check unset reference. For scalar parameters, it is clearly
4059 -- wrong to pass an uninitialized value as either an IN or
4060 -- IN-OUT parameter. For composites, it is also clearly an
4061 -- error to pass a completely uninitialized value as an IN
4062 -- parameter, but the case of IN OUT is trickier. We prefer
4063 -- not to give a warning here. For example, suppose there is
4064 -- a routine that sets some component of a record to False.
4065 -- It is perfectly reasonable to make this IN-OUT and allow
4066 -- either initialized or uninitialized records to be passed
4069 -- For partially initialized composite values, we also avoid
4070 -- warnings, since it is quite likely that we are passing a
4071 -- partially initialized value and only the initialized fields
4072 -- will in fact be read in the subprogram.
4074 if Is_Scalar_Type (A_Typ)
4075 or else (Ekind (F) = E_In_Parameter
4076 and then not Is_Partially_Initialized_Type (A_Typ))
4078 Check_Unset_Reference (A);
4081 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4082 -- actual to a nested call, since this constitutes a reading of
4083 -- the parameter, which is not allowed.
4085 if Is_Entity_Name (A)
4086 and then Ekind (Entity (A)) = E_Out_Parameter
4088 if Ada_Version = Ada_83 then
4090 ("(Ada 83) illegal reading of out parameter", A);
4092 -- An effectively volatile OUT parameter cannot act as IN or
4093 -- IN OUT actual in a call (SPARK RM 7.1.3(11)).
4095 elsif SPARK_Mode = On
4096 and then Is_Effectively_Volatile (Entity (A))
4099 ("illegal reading of volatile OUT parameter", A);
4104 -- Case of OUT or IN OUT parameter
4106 if Ekind (F) /= E_In_Parameter then
4108 -- For an Out parameter, check for useless assignment. Note
4109 -- that we can't set Last_Assignment this early, because we may
4110 -- kill current values in Resolve_Call, and that call would
4111 -- clobber the Last_Assignment field.
4113 -- Note: call Warn_On_Useless_Assignment before doing the check
4114 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4115 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4116 -- reflects the last assignment, not this one.
4118 if Ekind (F) = E_Out_Parameter then
4119 if Warn_On_Modified_As_Out_Parameter (F)
4120 and then Is_Entity_Name (A)
4121 and then Present (Entity (A))
4122 and then Comes_From_Source (N)
4124 Warn_On_Useless_Assignment (Entity (A), A);
4128 -- Validate the form of the actual. Note that the call to
4129 -- Is_OK_Variable_For_Out_Formal generates the required
4130 -- reference in this case.
4132 -- A call to an initialization procedure for an aggregate
4133 -- component may initialize a nested component of a constant
4134 -- designated object. In this context the object is variable.
4136 if not Is_OK_Variable_For_Out_Formal (A)
4137 and then not Is_Init_Proc (Nam)
4139 Error_Msg_NE ("actual for& must be a variable", A, F);
4141 if Is_Subprogram (Current_Scope)
4143 (Is_Invariant_Procedure (Current_Scope)
4144 or else Is_Predicate_Function (Current_Scope))
4147 ("function used in predicate cannot "
4148 & "modify its argument", F);
4152 -- What's the following about???
4154 if Is_Entity_Name (A) then
4155 Kill_Checks (Entity (A));
4161 if Etype (A) = Any_Type then
4162 Set_Etype (N, Any_Type);
4166 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4168 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4170 -- Apply predicate tests except in certain special cases. Note
4171 -- that it might be more consistent to apply these only when
4172 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4173 -- for the outbound predicate tests ???
4175 if Predicate_Tests_On_Arguments (Nam) then
4176 Apply_Predicate_Check (A, F_Typ);
4179 -- Apply required constraint checks
4181 -- Gigi looks at the check flag and uses the appropriate types.
4182 -- For now since one flag is used there is an optimization
4183 -- which might not be done in the IN OUT case since Gigi does
4184 -- not do any analysis. More thought required about this ???
4186 -- In fact is this comment obsolete??? doesn't the expander now
4187 -- generate all these tests anyway???
4189 if Is_Scalar_Type (Etype (A)) then
4190 Apply_Scalar_Range_Check (A, F_Typ);
4192 elsif Is_Array_Type (Etype (A)) then
4193 Apply_Length_Check (A, F_Typ);
4195 elsif Is_Record_Type (F_Typ)
4196 and then Has_Discriminants (F_Typ)
4197 and then Is_Constrained (F_Typ)
4198 and then (not Is_Derived_Type (F_Typ)
4199 or else Comes_From_Source (Nam))
4201 Apply_Discriminant_Check (A, F_Typ);
4203 -- For view conversions of a discriminated object, apply
4204 -- check to object itself, the conversion alreay has the
4207 if Nkind (A) = N_Type_Conversion
4208 and then Is_Constrained (Etype (Expression (A)))
4210 Apply_Discriminant_Check (Expression (A), F_Typ);
4213 elsif Is_Access_Type (F_Typ)
4214 and then Is_Array_Type (Designated_Type (F_Typ))
4215 and then Is_Constrained (Designated_Type (F_Typ))
4217 Apply_Length_Check (A, F_Typ);
4219 elsif Is_Access_Type (F_Typ)
4220 and then Has_Discriminants (Designated_Type (F_Typ))
4221 and then Is_Constrained (Designated_Type (F_Typ))
4223 Apply_Discriminant_Check (A, F_Typ);
4226 Apply_Range_Check (A, F_Typ);
4229 -- Ada 2005 (AI-231): Note that the controlling parameter case
4230 -- already existed in Ada 95, which is partially checked
4231 -- elsewhere (see Checks), and we don't want the warning
4232 -- message to differ.
4234 if Is_Access_Type (F_Typ)
4235 and then Can_Never_Be_Null (F_Typ)
4236 and then Known_Null (A)
4238 if Is_Controlling_Formal (F) then
4239 Apply_Compile_Time_Constraint_Error
4241 Msg => "null value not allowed here??",
4242 Reason => CE_Access_Check_Failed);
4244 elsif Ada_Version >= Ada_2005 then
4245 Apply_Compile_Time_Constraint_Error
4247 Msg => "(Ada 2005) null not allowed in "
4248 & "null-excluding formal??",
4249 Reason => CE_Null_Not_Allowed);
4254 -- Checks for OUT parameters and IN OUT parameters
4256 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4258 -- If there is a type conversion, to make sure the return value
4259 -- meets the constraints of the variable before the conversion.
4261 if Nkind (A) = N_Type_Conversion then
4262 if Is_Scalar_Type (A_Typ) then
4263 Apply_Scalar_Range_Check
4264 (Expression (A), Etype (Expression (A)), A_Typ);
4267 (Expression (A), Etype (Expression (A)), A_Typ);
4270 -- If no conversion apply scalar range checks and length checks
4271 -- base on the subtype of the actual (NOT that of the formal).
4274 if Is_Scalar_Type (F_Typ) then
4275 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4276 elsif Is_Array_Type (F_Typ)
4277 and then Ekind (F) = E_Out_Parameter
4279 Apply_Length_Check (A, F_Typ);
4281 Apply_Range_Check (A, A_Typ, F_Typ);
4285 -- Note: we do not apply the predicate checks for the case of
4286 -- OUT and IN OUT parameters. They are instead applied in the
4287 -- Expand_Actuals routine in Exp_Ch6.
4290 -- An actual associated with an access parameter is implicitly
4291 -- converted to the anonymous access type of the formal and must
4292 -- satisfy the legality checks for access conversions.
4294 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4295 if not Valid_Conversion (A, F_Typ, A) then
4297 ("invalid implicit conversion for access parameter", A);
4300 -- If the actual is an access selected component of a variable,
4301 -- the call may modify its designated object. It is reasonable
4302 -- to treat this as a potential modification of the enclosing
4303 -- record, to prevent spurious warnings that it should be
4304 -- declared as a constant, because intuitively programmers
4305 -- regard the designated subcomponent as part of the record.
4307 if Nkind (A) = N_Selected_Component
4308 and then Is_Entity_Name (Prefix (A))
4309 and then not Is_Constant_Object (Entity (Prefix (A)))
4311 Note_Possible_Modification (A, Sure => False);
4315 -- Check bad case of atomic/volatile argument (RM C.6(12))
4317 if Is_By_Reference_Type (Etype (F))
4318 and then Comes_From_Source (N)
4320 if Is_Atomic_Object (A)
4321 and then not Is_Atomic (Etype (F))
4324 ("cannot pass atomic argument to non-atomic formal&",
4327 elsif Is_Volatile_Object (A)
4328 and then not Is_Volatile (Etype (F))
4331 ("cannot pass volatile argument to non-volatile formal&",
4336 -- Check that subprograms don't have improper controlling
4337 -- arguments (RM 3.9.2 (9)).
4339 -- A primitive operation may have an access parameter of an
4340 -- incomplete tagged type, but a dispatching call is illegal
4341 -- if the type is still incomplete.
4343 if Is_Controlling_Formal (F) then
4344 Set_Is_Controlling_Actual (A);
4346 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4348 Desig : constant Entity_Id := Designated_Type (Etype (F));
4350 if Ekind (Desig) = E_Incomplete_Type
4351 and then No (Full_View (Desig))
4352 and then No (Non_Limited_View (Desig))
4355 ("premature use of incomplete type& "
4356 & "in dispatching call", A, Desig);
4361 elsif Nkind (A) = N_Explicit_Dereference then
4362 Validate_Remote_Access_To_Class_Wide_Type (A);
4365 -- Apply legality rule 3.9.2 (9/1)
4367 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4368 and then not Is_Class_Wide_Type (F_Typ)
4369 and then not Is_Controlling_Formal (F)
4370 and then not In_Instance
4372 Error_Msg_N ("class-wide argument not allowed here!", A);
4374 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4375 Error_Msg_Node_2 := F_Typ;
4377 ("& is not a dispatching operation of &!", A, Nam);
4380 -- Apply the checks described in 3.10.2(27): if the context is a
4381 -- specific access-to-object, the actual cannot be class-wide.
4382 -- Use base type to exclude access_to_subprogram cases.
4384 elsif Is_Access_Type (A_Typ)
4385 and then Is_Access_Type (F_Typ)
4386 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4387 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4388 or else (Nkind (A) = N_Attribute_Reference
4390 Is_Class_Wide_Type (Etype (Prefix (A)))))
4391 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4392 and then not Is_Controlling_Formal (F)
4394 -- Disable these checks for call to imported C++ subprograms
4397 (Is_Entity_Name (Name (N))
4398 and then Is_Imported (Entity (Name (N)))
4399 and then Convention (Entity (Name (N))) = Convention_CPP)
4402 ("access to class-wide argument not allowed here!", A);
4404 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4405 Error_Msg_Node_2 := Designated_Type (F_Typ);
4407 ("& is not a dispatching operation of &!", A, Nam);
4411 Check_Aliased_Parameter;
4415 -- If it is a named association, treat the selector_name as a
4416 -- proper identifier, and mark the corresponding entity.
4418 if Nkind (Parent (A)) = N_Parameter_Association
4420 -- Ignore reference in SPARK mode, as it refers to an entity not
4421 -- in scope at the point of reference, so the reference should
4422 -- be ignored for computing effects of subprograms.
4424 and then not GNATprove_Mode
4426 -- If subprogram is overridden, use name of formal that
4429 if Present (Real_Subp) then
4430 Set_Entity (Selector_Name (Parent (A)), Real_F);
4431 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4434 Set_Entity (Selector_Name (Parent (A)), F);
4435 Generate_Reference (F, Selector_Name (Parent (A)));
4436 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4437 Generate_Reference (F_Typ, N, ' ');
4443 if Ekind (F) /= E_Out_Parameter then
4444 Check_Unset_Reference (A);
4447 -- The following checks are only relevant when SPARK_Mode is on as
4448 -- they are not standard Ada legality rule. Internally generated
4449 -- temporaries are ignored.
4452 and then Is_Effectively_Volatile_Object (A)
4453 and then Comes_From_Source (A)
4455 -- An effectively volatile object may act as an actual
4456 -- parameter when the corresponding formal is of a non-scalar
4459 if Is_Volatile (Etype (F))
4460 and then not Is_Scalar_Type (Etype (F))
4464 -- An effectively volatile object may act as an actual
4465 -- parameter in a call to an instance of Unchecked_Conversion.
4467 elsif Is_Unchecked_Conversion_Instance (Nam) then
4472 ("volatile object cannot act as actual in a call (SPARK "
4473 & "RM 7.1.3(12))", A);
4476 -- Detect an external variable with an enabled property that
4477 -- does not match the mode of the corresponding formal in a
4478 -- procedure call. Functions are not considered because they
4479 -- cannot have effectively volatile formal parameters in the
4482 if Ekind (Nam) = E_Procedure
4483 and then Ekind (F) = E_In_Parameter
4484 and then Is_Entity_Name (A)
4485 and then Present (Entity (A))
4486 and then Ekind (Entity (A)) = E_Variable
4490 if Async_Readers_Enabled (A_Id) then
4491 Property_Error (A, A_Id, Name_Async_Readers);
4492 elsif Effective_Reads_Enabled (A_Id) then
4493 Property_Error (A, A_Id, Name_Effective_Reads);
4494 elsif Effective_Writes_Enabled (A_Id) then
4495 Property_Error (A, A_Id, Name_Effective_Writes);
4500 -- A formal parameter of a specific tagged type whose related
4501 -- subprogram is subject to pragma Extensions_Visible with value
4502 -- "False" cannot act as an actual in a subprogram with value
4503 -- "True" (SPARK RM 6.1.7(3)).
4505 if Is_EVF_Expression (A)
4506 and then Extensions_Visible_Status (Nam) =
4507 Extensions_Visible_True
4510 ("formal parameter with Extensions_Visible False cannot act "
4511 & "as actual parameter", A);
4513 ("\subprogram & has Extensions_Visible True", A, Nam);
4516 -- The actual parameter of a Ghost subprogram whose formal is of
4517 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(13)).
4519 if Is_Ghost_Entity (Nam)
4520 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4521 and then Is_Entity_Name (A)
4522 and then Present (Entity (A))
4523 and then not Is_Ghost_Entity (Entity (A))
4526 ("non-ghost variable & cannot appear as actual in call to "
4527 & "ghost procedure", A, Entity (A));
4529 if Ekind (F) = E_In_Out_Parameter then
4530 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4532 Error_Msg_N ("\corresponding formal has mode OUT", A);
4538 if Present (Real_Subp) then
4539 Next_Formal (Real_F);
4542 -- Case where actual is not present
4550 end Resolve_Actuals;
4552 -----------------------
4553 -- Resolve_Allocator --
4554 -----------------------
4556 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4557 Desig_T : constant Entity_Id := Designated_Type (Typ);
4558 E : constant Node_Id := Expression (N);
4560 Discrim : Entity_Id;
4563 Assoc : Node_Id := Empty;
4566 procedure Check_Allocator_Discrim_Accessibility
4567 (Disc_Exp : Node_Id;
4568 Alloc_Typ : Entity_Id);
4569 -- Check that accessibility level associated with an access discriminant
4570 -- initialized in an allocator by the expression Disc_Exp is not deeper
4571 -- than the level of the allocator type Alloc_Typ. An error message is
4572 -- issued if this condition is violated. Specialized checks are done for
4573 -- the cases of a constraint expression which is an access attribute or
4574 -- an access discriminant.
4576 function In_Dispatching_Context return Boolean;
4577 -- If the allocator is an actual in a call, it is allowed to be class-
4578 -- wide when the context is not because it is a controlling actual.
4580 -------------------------------------------
4581 -- Check_Allocator_Discrim_Accessibility --
4582 -------------------------------------------
4584 procedure Check_Allocator_Discrim_Accessibility
4585 (Disc_Exp : Node_Id;
4586 Alloc_Typ : Entity_Id)
4589 if Type_Access_Level (Etype (Disc_Exp)) >
4590 Deepest_Type_Access_Level (Alloc_Typ)
4593 ("operand type has deeper level than allocator type", Disc_Exp);
4595 -- When the expression is an Access attribute the level of the prefix
4596 -- object must not be deeper than that of the allocator's type.
4598 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4599 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4601 and then Object_Access_Level (Prefix (Disc_Exp)) >
4602 Deepest_Type_Access_Level (Alloc_Typ)
4605 ("prefix of attribute has deeper level than allocator type",
4608 -- When the expression is an access discriminant the check is against
4609 -- the level of the prefix object.
4611 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4612 and then Nkind (Disc_Exp) = N_Selected_Component
4613 and then Object_Access_Level (Prefix (Disc_Exp)) >
4614 Deepest_Type_Access_Level (Alloc_Typ)
4617 ("access discriminant has deeper level than allocator type",
4620 -- All other cases are legal
4625 end Check_Allocator_Discrim_Accessibility;
4627 ----------------------------
4628 -- In_Dispatching_Context --
4629 ----------------------------
4631 function In_Dispatching_Context return Boolean is
4632 Par : constant Node_Id := Parent (N);
4635 return Nkind (Par) in N_Subprogram_Call
4636 and then Is_Entity_Name (Name (Par))
4637 and then Is_Dispatching_Operation (Entity (Name (Par)));
4638 end In_Dispatching_Context;
4640 -- Start of processing for Resolve_Allocator
4643 -- Replace general access with specific type
4645 if Ekind (Etype (N)) = E_Allocator_Type then
4646 Set_Etype (N, Base_Type (Typ));
4649 if Is_Abstract_Type (Typ) then
4650 Error_Msg_N ("type of allocator cannot be abstract", N);
4653 -- For qualified expression, resolve the expression using the given
4654 -- subtype (nothing to do for type mark, subtype indication)
4656 if Nkind (E) = N_Qualified_Expression then
4657 if Is_Class_Wide_Type (Etype (E))
4658 and then not Is_Class_Wide_Type (Desig_T)
4659 and then not In_Dispatching_Context
4662 ("class-wide allocator not allowed for this access type", N);
4665 Resolve (Expression (E), Etype (E));
4666 Check_Non_Static_Context (Expression (E));
4667 Check_Unset_Reference (Expression (E));
4669 -- A qualified expression requires an exact match of the type.
4670 -- Class-wide matching is not allowed.
4672 if (Is_Class_Wide_Type (Etype (Expression (E)))
4673 or else Is_Class_Wide_Type (Etype (E)))
4674 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4676 Wrong_Type (Expression (E), Etype (E));
4679 -- Calls to build-in-place functions are not currently supported in
4680 -- allocators for access types associated with a simple storage pool.
4681 -- Supporting such allocators may require passing additional implicit
4682 -- parameters to build-in-place functions (or a significant revision
4683 -- of the current b-i-p implementation to unify the handling for
4684 -- multiple kinds of storage pools). ???
4686 if Is_Limited_View (Desig_T)
4687 and then Nkind (Expression (E)) = N_Function_Call
4690 Pool : constant Entity_Id :=
4691 Associated_Storage_Pool (Root_Type (Typ));
4695 Present (Get_Rep_Pragma
4696 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4699 ("limited function calls not yet supported in simple "
4700 & "storage pool allocators", Expression (E));
4705 -- A special accessibility check is needed for allocators that
4706 -- constrain access discriminants. The level of the type of the
4707 -- expression used to constrain an access discriminant cannot be
4708 -- deeper than the type of the allocator (in contrast to access
4709 -- parameters, where the level of the actual can be arbitrary).
4711 -- We can't use Valid_Conversion to perform this check because in
4712 -- general the type of the allocator is unrelated to the type of
4713 -- the access discriminant.
4715 if Ekind (Typ) /= E_Anonymous_Access_Type
4716 or else Is_Local_Anonymous_Access (Typ)
4718 Subtyp := Entity (Subtype_Mark (E));
4720 Aggr := Original_Node (Expression (E));
4722 if Has_Discriminants (Subtyp)
4723 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4725 Discrim := First_Discriminant (Base_Type (Subtyp));
4727 -- Get the first component expression of the aggregate
4729 if Present (Expressions (Aggr)) then
4730 Disc_Exp := First (Expressions (Aggr));
4732 elsif Present (Component_Associations (Aggr)) then
4733 Assoc := First (Component_Associations (Aggr));
4735 if Present (Assoc) then
4736 Disc_Exp := Expression (Assoc);
4745 while Present (Discrim) and then Present (Disc_Exp) loop
4746 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4747 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4750 Next_Discriminant (Discrim);
4752 if Present (Discrim) then
4753 if Present (Assoc) then
4755 Disc_Exp := Expression (Assoc);
4757 elsif Present (Next (Disc_Exp)) then
4761 Assoc := First (Component_Associations (Aggr));
4763 if Present (Assoc) then
4764 Disc_Exp := Expression (Assoc);
4774 -- For a subtype mark or subtype indication, freeze the subtype
4777 Freeze_Expression (E);
4779 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4781 ("initialization required for access-to-constant allocator", N);
4784 -- A special accessibility check is needed for allocators that
4785 -- constrain access discriminants. The level of the type of the
4786 -- expression used to constrain an access discriminant cannot be
4787 -- deeper than the type of the allocator (in contrast to access
4788 -- parameters, where the level of the actual can be arbitrary).
4789 -- We can't use Valid_Conversion to perform this check because
4790 -- in general the type of the allocator is unrelated to the type
4791 -- of the access discriminant.
4793 if Nkind (Original_Node (E)) = N_Subtype_Indication
4794 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4795 or else Is_Local_Anonymous_Access (Typ))
4797 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4799 if Has_Discriminants (Subtyp) then
4800 Discrim := First_Discriminant (Base_Type (Subtyp));
4801 Constr := First (Constraints (Constraint (Original_Node (E))));
4802 while Present (Discrim) and then Present (Constr) loop
4803 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4804 if Nkind (Constr) = N_Discriminant_Association then
4805 Disc_Exp := Original_Node (Expression (Constr));
4807 Disc_Exp := Original_Node (Constr);
4810 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4813 Next_Discriminant (Discrim);
4820 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4821 -- check that the level of the type of the created object is not deeper
4822 -- than the level of the allocator's access type, since extensions can
4823 -- now occur at deeper levels than their ancestor types. This is a
4824 -- static accessibility level check; a run-time check is also needed in
4825 -- the case of an initialized allocator with a class-wide argument (see
4826 -- Expand_Allocator_Expression).
4828 if Ada_Version >= Ada_2005
4829 and then Is_Class_Wide_Type (Desig_T)
4832 Exp_Typ : Entity_Id;
4835 if Nkind (E) = N_Qualified_Expression then
4836 Exp_Typ := Etype (E);
4837 elsif Nkind (E) = N_Subtype_Indication then
4838 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4840 Exp_Typ := Entity (E);
4843 if Type_Access_Level (Exp_Typ) >
4844 Deepest_Type_Access_Level (Typ)
4846 if In_Instance_Body then
4847 Error_Msg_Warn := SPARK_Mode /= On;
4849 ("type in allocator has deeper level than "
4850 & "designated class-wide type<<", E);
4851 Error_Msg_N ("\Program_Error [<<", E);
4853 Make_Raise_Program_Error (Sloc (N),
4854 Reason => PE_Accessibility_Check_Failed));
4857 -- Do not apply Ada 2005 accessibility checks on a class-wide
4858 -- allocator if the type given in the allocator is a formal
4859 -- type. A run-time check will be performed in the instance.
4861 elsif not Is_Generic_Type (Exp_Typ) then
4862 Error_Msg_N ("type in allocator has deeper level than "
4863 & "designated class-wide type", E);
4869 -- Check for allocation from an empty storage pool
4871 if No_Pool_Assigned (Typ) then
4872 Error_Msg_N ("allocation from empty storage pool!", N);
4874 -- If the context is an unchecked conversion, as may happen within an
4875 -- inlined subprogram, the allocator is being resolved with its own
4876 -- anonymous type. In that case, if the target type has a specific
4877 -- storage pool, it must be inherited explicitly by the allocator type.
4879 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4880 and then No (Associated_Storage_Pool (Typ))
4882 Set_Associated_Storage_Pool
4883 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4886 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4887 Check_Restriction (No_Anonymous_Allocators, N);
4890 -- Check that an allocator with task parts isn't for a nested access
4891 -- type when restriction No_Task_Hierarchy applies.
4893 if not Is_Library_Level_Entity (Base_Type (Typ))
4894 and then Has_Task (Base_Type (Desig_T))
4896 Check_Restriction (No_Task_Hierarchy, N);
4899 -- An illegal allocator may be rewritten as a raise Program_Error
4902 if Nkind (N) = N_Allocator then
4904 -- An anonymous access discriminant is the definition of a
4907 if Ekind (Typ) = E_Anonymous_Access_Type
4908 and then Nkind (Associated_Node_For_Itype (Typ)) =
4909 N_Discriminant_Specification
4912 Discr : constant Entity_Id :=
4913 Defining_Identifier (Associated_Node_For_Itype (Typ));
4916 Check_Restriction (No_Coextensions, N);
4918 -- Ada 2012 AI05-0052: If the designated type of the allocator
4919 -- is limited, then the allocator shall not be used to define
4920 -- the value of an access discriminant unless the discriminated
4921 -- type is immutably limited.
4923 if Ada_Version >= Ada_2012
4924 and then Is_Limited_Type (Desig_T)
4925 and then not Is_Limited_View (Scope (Discr))
4928 ("only immutably limited types can have anonymous "
4929 & "access discriminants designating a limited type", N);
4933 -- Avoid marking an allocator as a dynamic coextension if it is
4934 -- within a static construct.
4936 if not Is_Static_Coextension (N) then
4937 Set_Is_Dynamic_Coextension (N);
4940 -- Cleanup for potential static coextensions
4943 Set_Is_Dynamic_Coextension (N, False);
4944 Set_Is_Static_Coextension (N, False);
4948 -- Report a simple error: if the designated object is a local task,
4949 -- its body has not been seen yet, and its activation will fail an
4950 -- elaboration check.
4952 if Is_Task_Type (Desig_T)
4953 and then Scope (Base_Type (Desig_T)) = Current_Scope
4954 and then Is_Compilation_Unit (Current_Scope)
4955 and then Ekind (Current_Scope) = E_Package
4956 and then not In_Package_Body (Current_Scope)
4958 Error_Msg_Warn := SPARK_Mode /= On;
4959 Error_Msg_N ("cannot activate task before body seen<<", N);
4960 Error_Msg_N ("\Program_Error [<<", N);
4963 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
4964 -- type with a task component on a subpool. This action must raise
4965 -- Program_Error at runtime.
4967 if Ada_Version >= Ada_2012
4968 and then Nkind (N) = N_Allocator
4969 and then Present (Subpool_Handle_Name (N))
4970 and then Has_Task (Desig_T)
4972 Error_Msg_Warn := SPARK_Mode /= On;
4973 Error_Msg_N ("cannot allocate task on subpool<<", N);
4974 Error_Msg_N ("\Program_Error [<<", N);
4977 Make_Raise_Program_Error (Sloc (N),
4978 Reason => PE_Explicit_Raise));
4981 end Resolve_Allocator;
4983 ---------------------------
4984 -- Resolve_Arithmetic_Op --
4985 ---------------------------
4987 -- Used for resolving all arithmetic operators except exponentiation
4989 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4990 L : constant Node_Id := Left_Opnd (N);
4991 R : constant Node_Id := Right_Opnd (N);
4992 TL : constant Entity_Id := Base_Type (Etype (L));
4993 TR : constant Entity_Id := Base_Type (Etype (R));
4997 B_Typ : constant Entity_Id := Base_Type (Typ);
4998 -- We do the resolution using the base type, because intermediate values
4999 -- in expressions always are of the base type, not a subtype of it.
5001 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5002 -- Returns True if N is in a context that expects "any real type"
5004 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5005 -- Return True iff given type is Integer or universal real/integer
5007 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5008 -- Choose type of integer literal in fixed-point operation to conform
5009 -- to available fixed-point type. T is the type of the other operand,
5010 -- which is needed to determine the expected type of N.
5012 procedure Set_Operand_Type (N : Node_Id);
5013 -- Set operand type to T if universal
5015 -------------------------------
5016 -- Expected_Type_Is_Any_Real --
5017 -------------------------------
5019 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5021 -- N is the expression after "delta" in a fixed_point_definition;
5024 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5025 N_Decimal_Fixed_Point_Definition,
5027 -- N is one of the bounds in a real_range_specification;
5030 N_Real_Range_Specification,
5032 -- N is the expression of a delta_constraint;
5035 N_Delta_Constraint);
5036 end Expected_Type_Is_Any_Real;
5038 -----------------------------
5039 -- Is_Integer_Or_Universal --
5040 -----------------------------
5042 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5044 Index : Interp_Index;
5048 if not Is_Overloaded (N) then
5050 return Base_Type (T) = Base_Type (Standard_Integer)
5051 or else T = Universal_Integer
5052 or else T = Universal_Real;
5054 Get_First_Interp (N, Index, It);
5055 while Present (It.Typ) loop
5056 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5057 or else It.Typ = Universal_Integer
5058 or else It.Typ = Universal_Real
5063 Get_Next_Interp (Index, It);
5068 end Is_Integer_Or_Universal;
5070 ----------------------------
5071 -- Set_Mixed_Mode_Operand --
5072 ----------------------------
5074 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5075 Index : Interp_Index;
5079 if Universal_Interpretation (N) = Universal_Integer then
5081 -- A universal integer literal is resolved as standard integer
5082 -- except in the case of a fixed-point result, where we leave it
5083 -- as universal (to be handled by Exp_Fixd later on)
5085 if Is_Fixed_Point_Type (T) then
5086 Resolve (N, Universal_Integer);
5088 Resolve (N, Standard_Integer);
5091 elsif Universal_Interpretation (N) = Universal_Real
5092 and then (T = Base_Type (Standard_Integer)
5093 or else T = Universal_Integer
5094 or else T = Universal_Real)
5096 -- A universal real can appear in a fixed-type context. We resolve
5097 -- the literal with that context, even though this might raise an
5098 -- exception prematurely (the other operand may be zero).
5102 elsif Etype (N) = Base_Type (Standard_Integer)
5103 and then T = Universal_Real
5104 and then Is_Overloaded (N)
5106 -- Integer arg in mixed-mode operation. Resolve with universal
5107 -- type, in case preference rule must be applied.
5109 Resolve (N, Universal_Integer);
5112 and then B_Typ /= Universal_Fixed
5114 -- Not a mixed-mode operation, resolve with context
5118 elsif Etype (N) = Any_Fixed then
5120 -- N may itself be a mixed-mode operation, so use context type
5124 elsif Is_Fixed_Point_Type (T)
5125 and then B_Typ = Universal_Fixed
5126 and then Is_Overloaded (N)
5128 -- Must be (fixed * fixed) operation, operand must have one
5129 -- compatible interpretation.
5131 Resolve (N, Any_Fixed);
5133 elsif Is_Fixed_Point_Type (B_Typ)
5134 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5135 and then Is_Overloaded (N)
5137 -- C * F(X) in a fixed context, where C is a real literal or a
5138 -- fixed-point expression. F must have either a fixed type
5139 -- interpretation or an integer interpretation, but not both.
5141 Get_First_Interp (N, Index, It);
5142 while Present (It.Typ) loop
5143 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5144 if Analyzed (N) then
5145 Error_Msg_N ("ambiguous operand in fixed operation", N);
5147 Resolve (N, Standard_Integer);
5150 elsif Is_Fixed_Point_Type (It.Typ) then
5151 if Analyzed (N) then
5152 Error_Msg_N ("ambiguous operand in fixed operation", N);
5154 Resolve (N, It.Typ);
5158 Get_Next_Interp (Index, It);
5161 -- Reanalyze the literal with the fixed type of the context. If
5162 -- context is Universal_Fixed, we are within a conversion, leave
5163 -- the literal as a universal real because there is no usable
5164 -- fixed type, and the target of the conversion plays no role in
5178 if B_Typ = Universal_Fixed
5179 and then Nkind (Op2) = N_Real_Literal
5181 T2 := Universal_Real;
5186 Set_Analyzed (Op2, False);
5193 end Set_Mixed_Mode_Operand;
5195 ----------------------
5196 -- Set_Operand_Type --
5197 ----------------------
5199 procedure Set_Operand_Type (N : Node_Id) is
5201 if Etype (N) = Universal_Integer
5202 or else Etype (N) = Universal_Real
5206 end Set_Operand_Type;
5208 -- Start of processing for Resolve_Arithmetic_Op
5211 if Comes_From_Source (N)
5212 and then Ekind (Entity (N)) = E_Function
5213 and then Is_Imported (Entity (N))
5214 and then Is_Intrinsic_Subprogram (Entity (N))
5216 Resolve_Intrinsic_Operator (N, Typ);
5219 -- Special-case for mixed-mode universal expressions or fixed point type
5220 -- operation: each argument is resolved separately. The same treatment
5221 -- is required if one of the operands of a fixed point operation is
5222 -- universal real, since in this case we don't do a conversion to a
5223 -- specific fixed-point type (instead the expander handles the case).
5225 -- Set the type of the node to its universal interpretation because
5226 -- legality checks on an exponentiation operand need the context.
5228 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5229 and then Present (Universal_Interpretation (L))
5230 and then Present (Universal_Interpretation (R))
5232 Set_Etype (N, B_Typ);
5233 Resolve (L, Universal_Interpretation (L));
5234 Resolve (R, Universal_Interpretation (R));
5236 elsif (B_Typ = Universal_Real
5237 or else Etype (N) = Universal_Fixed
5238 or else (Etype (N) = Any_Fixed
5239 and then Is_Fixed_Point_Type (B_Typ))
5240 or else (Is_Fixed_Point_Type (B_Typ)
5241 and then (Is_Integer_Or_Universal (L)
5243 Is_Integer_Or_Universal (R))))
5244 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5246 if TL = Universal_Integer or else TR = Universal_Integer then
5247 Check_For_Visible_Operator (N, B_Typ);
5250 -- If context is a fixed type and one operand is integer, the other
5251 -- is resolved with the type of the context.
5253 if Is_Fixed_Point_Type (B_Typ)
5254 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5255 or else TL = Universal_Integer)
5260 elsif Is_Fixed_Point_Type (B_Typ)
5261 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5262 or else TR = Universal_Integer)
5268 Set_Mixed_Mode_Operand (L, TR);
5269 Set_Mixed_Mode_Operand (R, TL);
5272 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5273 -- multiplying operators from being used when the expected type is
5274 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5275 -- some cases where the expected type is actually Any_Real;
5276 -- Expected_Type_Is_Any_Real takes care of that case.
5278 if Etype (N) = Universal_Fixed
5279 or else Etype (N) = Any_Fixed
5281 if B_Typ = Universal_Fixed
5282 and then not Expected_Type_Is_Any_Real (N)
5283 and then not Nkind_In (Parent (N), N_Type_Conversion,
5284 N_Unchecked_Type_Conversion)
5286 Error_Msg_N ("type cannot be determined from context!", N);
5287 Error_Msg_N ("\explicit conversion to result type required", N);
5289 Set_Etype (L, Any_Type);
5290 Set_Etype (R, Any_Type);
5293 if Ada_Version = Ada_83
5294 and then Etype (N) = Universal_Fixed
5296 Nkind_In (Parent (N), N_Type_Conversion,
5297 N_Unchecked_Type_Conversion)
5300 ("(Ada 83) fixed-point operation needs explicit "
5304 -- The expected type is "any real type" in contexts like
5306 -- type T is delta <universal_fixed-expression> ...
5308 -- in which case we need to set the type to Universal_Real
5309 -- so that static expression evaluation will work properly.
5311 if Expected_Type_Is_Any_Real (N) then
5312 Set_Etype (N, Universal_Real);
5314 Set_Etype (N, B_Typ);
5318 elsif Is_Fixed_Point_Type (B_Typ)
5319 and then (Is_Integer_Or_Universal (L)
5320 or else Nkind (L) = N_Real_Literal
5321 or else Nkind (R) = N_Real_Literal
5322 or else Is_Integer_Or_Universal (R))
5324 Set_Etype (N, B_Typ);
5326 elsif Etype (N) = Any_Fixed then
5328 -- If no previous errors, this is only possible if one operand is
5329 -- overloaded and the context is universal. Resolve as such.
5331 Set_Etype (N, B_Typ);
5335 if (TL = Universal_Integer or else TL = Universal_Real)
5337 (TR = Universal_Integer or else TR = Universal_Real)
5339 Check_For_Visible_Operator (N, B_Typ);
5342 -- If the context is Universal_Fixed and the operands are also
5343 -- universal fixed, this is an error, unless there is only one
5344 -- applicable fixed_point type (usually Duration).
5346 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5347 T := Unique_Fixed_Point_Type (N);
5349 if T = Any_Type then
5362 -- If one of the arguments was resolved to a non-universal type.
5363 -- label the result of the operation itself with the same type.
5364 -- Do the same for the universal argument, if any.
5366 T := Intersect_Types (L, R);
5367 Set_Etype (N, Base_Type (T));
5368 Set_Operand_Type (L);
5369 Set_Operand_Type (R);
5372 Generate_Operator_Reference (N, Typ);
5373 Analyze_Dimension (N);
5374 Eval_Arithmetic_Op (N);
5376 -- In SPARK, a multiplication or division with operands of fixed point
5377 -- types must be qualified or explicitly converted to identify the
5380 if (Is_Fixed_Point_Type (Etype (L))
5381 or else Is_Fixed_Point_Type (Etype (R)))
5382 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5384 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5386 Check_SPARK_05_Restriction
5387 ("operation should be qualified or explicitly converted", N);
5390 -- Set overflow and division checking bit
5392 if Nkind (N) in N_Op then
5393 if not Overflow_Checks_Suppressed (Etype (N)) then
5394 Enable_Overflow_Check (N);
5397 -- Give warning if explicit division by zero
5399 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5400 and then not Division_Checks_Suppressed (Etype (N))
5402 Rop := Right_Opnd (N);
5404 if Compile_Time_Known_Value (Rop)
5405 and then ((Is_Integer_Type (Etype (Rop))
5406 and then Expr_Value (Rop) = Uint_0)
5408 (Is_Real_Type (Etype (Rop))
5409 and then Expr_Value_R (Rop) = Ureal_0))
5411 -- Specialize the warning message according to the operation.
5412 -- The following warnings are for the case
5417 -- For division, we have two cases, for float division
5418 -- of an unconstrained float type, on a machine where
5419 -- Machine_Overflows is false, we don't get an exception
5420 -- at run-time, but rather an infinity or Nan. The Nan
5421 -- case is pretty obscure, so just warn about infinities.
5423 if Is_Floating_Point_Type (Typ)
5424 and then not Is_Constrained (Typ)
5425 and then not Machine_Overflows_On_Target
5428 ("float division by zero, may generate "
5429 & "'+'/'- infinity??", Right_Opnd (N));
5431 -- For all other cases, we get a Constraint_Error
5434 Apply_Compile_Time_Constraint_Error
5435 (N, "division by zero??", CE_Divide_By_Zero,
5436 Loc => Sloc (Right_Opnd (N)));
5440 Apply_Compile_Time_Constraint_Error
5441 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5442 Loc => Sloc (Right_Opnd (N)));
5445 Apply_Compile_Time_Constraint_Error
5446 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5447 Loc => Sloc (Right_Opnd (N)));
5449 -- Division by zero can only happen with division, rem,
5450 -- and mod operations.
5453 raise Program_Error;
5456 -- Otherwise just set the flag to check at run time
5459 Activate_Division_Check (N);
5463 -- If Restriction No_Implicit_Conditionals is active, then it is
5464 -- violated if either operand can be negative for mod, or for rem
5465 -- if both operands can be negative.
5467 if Restriction_Check_Required (No_Implicit_Conditionals)
5468 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5477 -- Set if corresponding operand might be negative
5481 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5482 LNeg := (not OK) or else Lo < 0;
5485 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5486 RNeg := (not OK) or else Lo < 0;
5488 -- Check if we will be generating conditionals. There are two
5489 -- cases where that can happen, first for REM, the only case
5490 -- is largest negative integer mod -1, where the division can
5491 -- overflow, but we still have to give the right result. The
5492 -- front end generates a test for this annoying case. Here we
5493 -- just test if both operands can be negative (that's what the
5494 -- expander does, so we match its logic here).
5496 -- The second case is mod where either operand can be negative.
5497 -- In this case, the back end has to generate additional tests.
5499 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5501 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5503 Check_Restriction (No_Implicit_Conditionals, N);
5509 Check_Unset_Reference (L);
5510 Check_Unset_Reference (R);
5511 Check_Function_Writable_Actuals (N);
5512 end Resolve_Arithmetic_Op;
5518 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5519 function Same_Or_Aliased_Subprograms
5521 E : Entity_Id) return Boolean;
5522 -- Returns True if the subprogram entity S is the same as E or else
5523 -- S is an alias of E.
5525 ---------------------------------
5526 -- Same_Or_Aliased_Subprograms --
5527 ---------------------------------
5529 function Same_Or_Aliased_Subprograms
5531 E : Entity_Id) return Boolean
5533 Subp_Alias : constant Entity_Id := Alias (S);
5535 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5536 end Same_Or_Aliased_Subprograms;
5540 Loc : constant Source_Ptr := Sloc (N);
5541 Subp : constant Node_Id := Name (N);
5542 Body_Id : Entity_Id;
5552 -- Start of processing for Resolve_Call
5555 -- The context imposes a unique interpretation with type Typ on a
5556 -- procedure or function call. Find the entity of the subprogram that
5557 -- yields the expected type, and propagate the corresponding formal
5558 -- constraints on the actuals. The caller has established that an
5559 -- interpretation exists, and emitted an error if not unique.
5561 -- First deal with the case of a call to an access-to-subprogram,
5562 -- dereference made explicit in Analyze_Call.
5564 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5565 if not Is_Overloaded (Subp) then
5566 Nam := Etype (Subp);
5569 -- Find the interpretation whose type (a subprogram type) has a
5570 -- return type that is compatible with the context. Analysis of
5571 -- the node has established that one exists.
5575 Get_First_Interp (Subp, I, It);
5576 while Present (It.Typ) loop
5577 if Covers (Typ, Etype (It.Typ)) then
5582 Get_Next_Interp (I, It);
5586 raise Program_Error;
5590 -- If the prefix is not an entity, then resolve it
5592 if not Is_Entity_Name (Subp) then
5593 Resolve (Subp, Nam);
5596 -- For an indirect call, we always invalidate checks, since we do not
5597 -- know whether the subprogram is local or global. Yes we could do
5598 -- better here, e.g. by knowing that there are no local subprograms,
5599 -- but it does not seem worth the effort. Similarly, we kill all
5600 -- knowledge of current constant values.
5602 Kill_Current_Values;
5604 -- If this is a procedure call which is really an entry call, do
5605 -- the conversion of the procedure call to an entry call. Protected
5606 -- operations use the same circuitry because the name in the call
5607 -- can be an arbitrary expression with special resolution rules.
5609 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5610 or else (Is_Entity_Name (Subp)
5611 and then Ekind (Entity (Subp)) = E_Entry)
5613 Resolve_Entry_Call (N, Typ);
5614 Check_Elab_Call (N);
5616 -- Kill checks and constant values, as above for indirect case
5617 -- Who knows what happens when another task is activated?
5619 Kill_Current_Values;
5622 -- Normal subprogram call with name established in Resolve
5624 elsif not (Is_Type (Entity (Subp))) then
5625 Nam := Entity (Subp);
5626 Set_Entity_With_Checks (Subp, Nam);
5628 -- Otherwise we must have the case of an overloaded call
5631 pragma Assert (Is_Overloaded (Subp));
5633 -- Initialize Nam to prevent warning (we know it will be assigned
5634 -- in the loop below, but the compiler does not know that).
5638 Get_First_Interp (Subp, I, It);
5639 while Present (It.Typ) loop
5640 if Covers (Typ, It.Typ) then
5642 Set_Entity_With_Checks (Subp, Nam);
5646 Get_Next_Interp (I, It);
5650 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5651 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5652 and then Nkind (Subp) /= N_Explicit_Dereference
5653 and then Present (Parameter_Associations (N))
5655 -- The prefix is a parameterless function call that returns an access
5656 -- to subprogram. If parameters are present in the current call, add
5657 -- add an explicit dereference. We use the base type here because
5658 -- within an instance these may be subtypes.
5660 -- The dereference is added either in Analyze_Call or here. Should
5661 -- be consolidated ???
5663 Set_Is_Overloaded (Subp, False);
5664 Set_Etype (Subp, Etype (Nam));
5665 Insert_Explicit_Dereference (Subp);
5666 Nam := Designated_Type (Etype (Nam));
5667 Resolve (Subp, Nam);
5670 -- Check that a call to Current_Task does not occur in an entry body
5672 if Is_RTE (Nam, RE_Current_Task) then
5681 -- Exclude calls that occur within the default of a formal
5682 -- parameter of the entry, since those are evaluated outside
5685 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5687 if Nkind (P) = N_Entry_Body
5688 or else (Nkind (P) = N_Subprogram_Body
5689 and then Is_Entry_Barrier_Function (P))
5692 Error_Msg_Warn := SPARK_Mode /= On;
5694 ("& should not be used in entry body (RM C.7(17))<<",
5696 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5698 Make_Raise_Program_Error (Loc,
5699 Reason => PE_Current_Task_In_Entry_Body));
5700 Set_Etype (N, Rtype);
5707 -- Check that a procedure call does not occur in the context of the
5708 -- entry call statement of a conditional or timed entry call. Note that
5709 -- the case of a call to a subprogram renaming of an entry will also be
5710 -- rejected. The test for N not being an N_Entry_Call_Statement is
5711 -- defensive, covering the possibility that the processing of entry
5712 -- calls might reach this point due to later modifications of the code
5715 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5716 and then Nkind (N) /= N_Entry_Call_Statement
5717 and then Entry_Call_Statement (Parent (N)) = N
5719 if Ada_Version < Ada_2005 then
5720 Error_Msg_N ("entry call required in select statement", N);
5722 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5723 -- for a procedure_or_entry_call, the procedure_name or
5724 -- procedure_prefix of the procedure_call_statement shall denote
5725 -- an entry renamed by a procedure, or (a view of) a primitive
5726 -- subprogram of a limited interface whose first parameter is
5727 -- a controlling parameter.
5729 elsif Nkind (N) = N_Procedure_Call_Statement
5730 and then not Is_Renamed_Entry (Nam)
5731 and then not Is_Controlling_Limited_Procedure (Nam)
5734 ("entry call or dispatching primitive of interface required", N);
5738 -- If the SPARK_05 restriction is active, we are not allowed
5739 -- to have a call to a subprogram before we see its completion.
5741 if not Has_Completion (Nam)
5742 and then Restriction_Check_Required (SPARK_05)
5744 -- Don't flag strange internal calls
5746 and then Comes_From_Source (N)
5747 and then Comes_From_Source (Nam)
5749 -- Only flag calls in extended main source
5751 and then In_Extended_Main_Source_Unit (Nam)
5752 and then In_Extended_Main_Source_Unit (N)
5754 -- Exclude enumeration literals from this processing
5756 and then Ekind (Nam) /= E_Enumeration_Literal
5758 Check_SPARK_05_Restriction
5759 ("call to subprogram cannot appear before its body", N);
5762 -- Check that this is not a call to a protected procedure or entry from
5763 -- within a protected function.
5765 Check_Internal_Protected_Use (N, Nam);
5767 -- Freeze the subprogram name if not in a spec-expression. Note that
5768 -- we freeze procedure calls as well as function calls. Procedure calls
5769 -- are not frozen according to the rules (RM 13.14(14)) because it is
5770 -- impossible to have a procedure call to a non-frozen procedure in
5771 -- pure Ada, but in the code that we generate in the expander, this
5772 -- rule needs extending because we can generate procedure calls that
5775 -- In Ada 2012, expression functions may be called within pre/post
5776 -- conditions of subsequent functions or expression functions. Such
5777 -- calls do not freeze when they appear within generated bodies,
5778 -- (including the body of another expression function) which would
5779 -- place the freeze node in the wrong scope. An expression function
5780 -- is frozen in the usual fashion, by the appearance of a real body,
5781 -- or at the end of a declarative part.
5783 if Is_Entity_Name (Subp) and then not In_Spec_Expression
5784 and then not Is_Expression_Function (Current_Scope)
5786 (not Is_Expression_Function (Entity (Subp))
5787 or else Scope (Entity (Subp)) = Current_Scope)
5789 Freeze_Expression (Subp);
5792 -- For a predefined operator, the type of the result is the type imposed
5793 -- by context, except for a predefined operation on universal fixed.
5794 -- Otherwise The type of the call is the type returned by the subprogram
5797 if Is_Predefined_Op (Nam) then
5798 if Etype (N) /= Universal_Fixed then
5802 -- If the subprogram returns an array type, and the context requires the
5803 -- component type of that array type, the node is really an indexing of
5804 -- the parameterless call. Resolve as such. A pathological case occurs
5805 -- when the type of the component is an access to the array type. In
5806 -- this case the call is truly ambiguous.
5808 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5810 ((Is_Array_Type (Etype (Nam))
5811 and then Covers (Typ, Component_Type (Etype (Nam))))
5813 (Is_Access_Type (Etype (Nam))
5814 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5816 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5819 Index_Node : Node_Id;
5821 Ret_Type : constant Entity_Id := Etype (Nam);
5824 if Is_Access_Type (Ret_Type)
5825 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5828 ("cannot disambiguate function call and indexing", N);
5830 New_Subp := Relocate_Node (Subp);
5832 -- The called entity may be an explicit dereference, in which
5833 -- case there is no entity to set.
5835 if Nkind (New_Subp) /= N_Explicit_Dereference then
5836 Set_Entity (Subp, Nam);
5839 if (Is_Array_Type (Ret_Type)
5840 and then Component_Type (Ret_Type) /= Any_Type)
5842 (Is_Access_Type (Ret_Type)
5844 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5846 if Needs_No_Actuals (Nam) then
5848 -- Indexed call to a parameterless function
5851 Make_Indexed_Component (Loc,
5853 Make_Function_Call (Loc, Name => New_Subp),
5854 Expressions => Parameter_Associations (N));
5856 -- An Ada 2005 prefixed call to a primitive operation
5857 -- whose first parameter is the prefix. This prefix was
5858 -- prepended to the parameter list, which is actually a
5859 -- list of indexes. Remove the prefix in order to build
5860 -- the proper indexed component.
5863 Make_Indexed_Component (Loc,
5865 Make_Function_Call (Loc,
5867 Parameter_Associations =>
5869 (Remove_Head (Parameter_Associations (N)))),
5870 Expressions => Parameter_Associations (N));
5873 -- Preserve the parenthesis count of the node
5875 Set_Paren_Count (Index_Node, Paren_Count (N));
5877 -- Since we are correcting a node classification error made
5878 -- by the parser, we call Replace rather than Rewrite.
5880 Replace (N, Index_Node);
5882 Set_Etype (Prefix (N), Ret_Type);
5884 Resolve_Indexed_Component (N, Typ);
5885 Check_Elab_Call (Prefix (N));
5893 Set_Etype (N, Etype (Nam));
5896 -- In the case where the call is to an overloaded subprogram, Analyze
5897 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5898 -- such a case Normalize_Actuals needs to be called once more to order
5899 -- the actuals correctly. Otherwise the call will have the ordering
5900 -- given by the last overloaded subprogram whether this is the correct
5901 -- one being called or not.
5903 if Is_Overloaded (Subp) then
5904 Normalize_Actuals (N, Nam, False, Norm_OK);
5905 pragma Assert (Norm_OK);
5908 -- In any case, call is fully resolved now. Reset Overload flag, to
5909 -- prevent subsequent overload resolution if node is analyzed again
5911 Set_Is_Overloaded (Subp, False);
5912 Set_Is_Overloaded (N, False);
5914 -- A Ghost entity must appear in a specific context
5916 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
5917 Check_Ghost_Context (Nam, N);
5920 -- If we are calling the current subprogram from immediately within its
5921 -- body, then that is the case where we can sometimes detect cases of
5922 -- infinite recursion statically. Do not try this in case restriction
5923 -- No_Recursion is in effect anyway, and do it only for source calls.
5925 if Comes_From_Source (N) then
5926 Scop := Current_Scope;
5928 -- Check violation of SPARK_05 restriction which does not permit
5929 -- a subprogram body to contain a call to the subprogram directly.
5931 if Restriction_Check_Required (SPARK_05)
5932 and then Same_Or_Aliased_Subprograms (Nam, Scop)
5934 Check_SPARK_05_Restriction
5935 ("subprogram may not contain direct call to itself", N);
5938 -- Issue warning for possible infinite recursion in the absence
5939 -- of the No_Recursion restriction.
5941 if Same_Or_Aliased_Subprograms (Nam, Scop)
5942 and then not Restriction_Active (No_Recursion)
5943 and then Check_Infinite_Recursion (N)
5945 -- Here we detected and flagged an infinite recursion, so we do
5946 -- not need to test the case below for further warnings. Also we
5947 -- are all done if we now have a raise SE node.
5949 if Nkind (N) = N_Raise_Storage_Error then
5953 -- If call is to immediately containing subprogram, then check for
5954 -- the case of a possible run-time detectable infinite recursion.
5957 Scope_Loop : while Scop /= Standard_Standard loop
5958 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5960 -- Although in general case, recursion is not statically
5961 -- checkable, the case of calling an immediately containing
5962 -- subprogram is easy to catch.
5964 Check_Restriction (No_Recursion, N);
5966 -- If the recursive call is to a parameterless subprogram,
5967 -- then even if we can't statically detect infinite
5968 -- recursion, this is pretty suspicious, and we output a
5969 -- warning. Furthermore, we will try later to detect some
5970 -- cases here at run time by expanding checking code (see
5971 -- Detect_Infinite_Recursion in package Exp_Ch6).
5973 -- If the recursive call is within a handler, do not emit a
5974 -- warning, because this is a common idiom: loop until input
5975 -- is correct, catch illegal input in handler and restart.
5977 if No (First_Formal (Nam))
5978 and then Etype (Nam) = Standard_Void_Type
5979 and then not Error_Posted (N)
5980 and then Nkind (Parent (N)) /= N_Exception_Handler
5982 -- For the case of a procedure call. We give the message
5983 -- only if the call is the first statement in a sequence
5984 -- of statements, or if all previous statements are
5985 -- simple assignments. This is simply a heuristic to
5986 -- decrease false positives, without losing too many good
5987 -- warnings. The idea is that these previous statements
5988 -- may affect global variables the procedure depends on.
5989 -- We also exclude raise statements, that may arise from
5990 -- constraint checks and are probably unrelated to the
5991 -- intended control flow.
5993 if Nkind (N) = N_Procedure_Call_Statement
5994 and then Is_List_Member (N)
6000 while Present (P) loop
6001 if not Nkind_In (P, N_Assignment_Statement,
6002 N_Raise_Constraint_Error)
6012 -- Do not give warning if we are in a conditional context
6015 K : constant Node_Kind := Nkind (Parent (N));
6017 if (K = N_Loop_Statement
6018 and then Present (Iteration_Scheme (Parent (N))))
6019 or else K = N_If_Statement
6020 or else K = N_Elsif_Part
6021 or else K = N_Case_Statement_Alternative
6027 -- Here warning is to be issued
6029 Set_Has_Recursive_Call (Nam);
6030 Error_Msg_Warn := SPARK_Mode /= On;
6031 Error_Msg_N ("possible infinite recursion<<!", N);
6032 Error_Msg_N ("\Storage_Error ]<<!", N);
6038 Scop := Scope (Scop);
6039 end loop Scope_Loop;
6043 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6045 Check_Obsolescent_2005_Entity (Nam, Subp);
6047 -- If subprogram name is a predefined operator, it was given in
6048 -- functional notation. Replace call node with operator node, so
6049 -- that actuals can be resolved appropriately.
6051 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6052 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6055 elsif Present (Alias (Nam))
6056 and then Is_Predefined_Op (Alias (Nam))
6058 Resolve_Actuals (N, Nam);
6059 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6063 -- Create a transient scope if the resulting type requires it
6065 -- There are several notable exceptions:
6067 -- a) In init procs, the transient scope overhead is not needed, and is
6068 -- even incorrect when the call is a nested initialization call for a
6069 -- component whose expansion may generate adjust calls. However, if the
6070 -- call is some other procedure call within an initialization procedure
6071 -- (for example a call to Create_Task in the init_proc of the task
6072 -- run-time record) a transient scope must be created around this call.
6074 -- b) Enumeration literal pseudo-calls need no transient scope
6076 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6077 -- functions) do not use the secondary stack even though the return
6078 -- type may be unconstrained.
6080 -- d) Calls to a build-in-place function, since such functions may
6081 -- allocate their result directly in a target object, and cases where
6082 -- the result does get allocated in the secondary stack are checked for
6083 -- within the specialized Exp_Ch6 procedures for expanding those
6084 -- build-in-place calls.
6086 -- e) If the subprogram is marked Inline_Always, then even if it returns
6087 -- an unconstrained type the call does not require use of the secondary
6088 -- stack. However, inlining will only take place if the body to inline
6089 -- is already present. It may not be available if e.g. the subprogram is
6090 -- declared in a child instance.
6092 -- If this is an initialization call for a type whose construction
6093 -- uses the secondary stack, and it is not a nested call to initialize
6094 -- a component, we do need to create a transient scope for it. We
6095 -- check for this by traversing the type in Check_Initialization_Call.
6098 and then Has_Pragma_Inline (Nam)
6099 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6100 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6104 elsif Ekind (Nam) = E_Enumeration_Literal
6105 or else Is_Build_In_Place_Function (Nam)
6106 or else Is_Intrinsic_Subprogram (Nam)
6110 elsif Expander_Active
6111 and then Is_Type (Etype (Nam))
6112 and then Requires_Transient_Scope (Etype (Nam))
6114 (not Within_Init_Proc
6116 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6118 Establish_Transient_Scope (N, Sec_Stack => True);
6120 -- If the call appears within the bounds of a loop, it will
6121 -- be rewritten and reanalyzed, nothing left to do here.
6123 if Nkind (N) /= N_Function_Call then
6127 elsif Is_Init_Proc (Nam)
6128 and then not Within_Init_Proc
6130 Check_Initialization_Call (N, Nam);
6133 -- A protected function cannot be called within the definition of the
6134 -- enclosing protected type, unless it is part of a pre/postcondition
6135 -- on another protected operation.
6137 if Is_Protected_Type (Scope (Nam))
6138 and then In_Open_Scopes (Scope (Nam))
6139 and then not Has_Completion (Scope (Nam))
6140 and then not In_Spec_Expression
6143 ("& cannot be called before end of protected definition", N, Nam);
6146 -- Propagate interpretation to actuals, and add default expressions
6149 if Present (First_Formal (Nam)) then
6150 Resolve_Actuals (N, Nam);
6152 -- Overloaded literals are rewritten as function calls, for purpose of
6153 -- resolution. After resolution, we can replace the call with the
6156 elsif Ekind (Nam) = E_Enumeration_Literal then
6157 Copy_Node (Subp, N);
6158 Resolve_Entity_Name (N, Typ);
6160 -- Avoid validation, since it is a static function call
6162 Generate_Reference (Nam, Subp);
6166 -- If the subprogram is not global, then kill all saved values and
6167 -- checks. This is a bit conservative, since in many cases we could do
6168 -- better, but it is not worth the effort. Similarly, we kill constant
6169 -- values. However we do not need to do this for internal entities
6170 -- (unless they are inherited user-defined subprograms), since they
6171 -- are not in the business of molesting local values.
6173 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6174 -- kill all checks and values for calls to global subprograms. This
6175 -- takes care of the case where an access to a local subprogram is
6176 -- taken, and could be passed directly or indirectly and then called
6177 -- from almost any context.
6179 -- Note: we do not do this step till after resolving the actuals. That
6180 -- way we still take advantage of the current value information while
6181 -- scanning the actuals.
6183 -- We suppress killing values if we are processing the nodes associated
6184 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6185 -- type kills all the values as part of analyzing the code that
6186 -- initializes the dispatch tables.
6188 if Inside_Freezing_Actions = 0
6189 and then (not Is_Library_Level_Entity (Nam)
6190 or else Suppress_Value_Tracking_On_Call
6191 (Nearest_Dynamic_Scope (Current_Scope)))
6192 and then (Comes_From_Source (Nam)
6193 or else (Present (Alias (Nam))
6194 and then Comes_From_Source (Alias (Nam))))
6196 Kill_Current_Values;
6199 -- If we are warning about unread OUT parameters, this is the place to
6200 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6201 -- after the above call to Kill_Current_Values (since that call clears
6202 -- the Last_Assignment field of all local variables).
6204 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6205 and then Comes_From_Source (N)
6206 and then In_Extended_Main_Source_Unit (N)
6213 F := First_Formal (Nam);
6214 A := First_Actual (N);
6215 while Present (F) and then Present (A) loop
6216 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6217 and then Warn_On_Modified_As_Out_Parameter (F)
6218 and then Is_Entity_Name (A)
6219 and then Present (Entity (A))
6220 and then Comes_From_Source (N)
6221 and then Safe_To_Capture_Value (N, Entity (A))
6223 Set_Last_Assignment (Entity (A), A);
6232 -- If the subprogram is a primitive operation, check whether or not
6233 -- it is a correct dispatching call.
6235 if Is_Overloadable (Nam)
6236 and then Is_Dispatching_Operation (Nam)
6238 Check_Dispatching_Call (N);
6240 elsif Ekind (Nam) /= E_Subprogram_Type
6241 and then Is_Abstract_Subprogram (Nam)
6242 and then not In_Instance
6244 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6247 -- If this is a dispatching call, generate the appropriate reference,
6248 -- for better source navigation in GPS.
6250 if Is_Overloadable (Nam)
6251 and then Present (Controlling_Argument (N))
6253 Generate_Reference (Nam, Subp, 'R');
6255 -- Normal case, not a dispatching call: generate a call reference
6258 Generate_Reference (Nam, Subp, 's');
6261 if Is_Intrinsic_Subprogram (Nam) then
6262 Check_Intrinsic_Call (N);
6265 -- Check for violation of restriction No_Specific_Termination_Handlers
6266 -- and warn on a potentially blocking call to Abort_Task.
6268 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6269 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6271 Is_RTE (Nam, RE_Specific_Handler))
6273 Check_Restriction (No_Specific_Termination_Handlers, N);
6275 elsif Is_RTE (Nam, RE_Abort_Task) then
6276 Check_Potentially_Blocking_Operation (N);
6279 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6280 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6281 -- need to check the second argument to determine whether it is an
6282 -- absolute or relative timing event.
6284 if Restriction_Check_Required (No_Relative_Delay)
6285 and then Is_RTE (Nam, RE_Set_Handler)
6286 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6288 Check_Restriction (No_Relative_Delay, N);
6291 -- Issue an error for a call to an eliminated subprogram. This routine
6292 -- will not perform the check if the call appears within a default
6295 Check_For_Eliminated_Subprogram (Subp, Nam);
6297 -- In formal mode, the primitive operations of a tagged type or type
6298 -- extension do not include functions that return the tagged type.
6300 if Nkind (N) = N_Function_Call
6301 and then Is_Tagged_Type (Etype (N))
6302 and then Is_Entity_Name (Name (N))
6303 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6305 Check_SPARK_05_Restriction ("function not inherited", N);
6308 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6309 -- class-wide and the call dispatches on result in a context that does
6310 -- not provide a tag, the call raises Program_Error.
6312 if Nkind (N) = N_Function_Call
6313 and then In_Instance
6314 and then Is_Generic_Actual_Type (Typ)
6315 and then Is_Class_Wide_Type (Typ)
6316 and then Has_Controlling_Result (Nam)
6317 and then Nkind (Parent (N)) = N_Object_Declaration
6319 -- Verify that none of the formals are controlling
6322 Call_OK : Boolean := False;
6326 F := First_Formal (Nam);
6327 while Present (F) loop
6328 if Is_Controlling_Formal (F) then
6337 Error_Msg_Warn := SPARK_Mode /= On;
6338 Error_Msg_N ("!cannot determine tag of result<<", N);
6339 Error_Msg_N ("\Program_Error [<<!", N);
6341 Make_Raise_Program_Error (Sloc (N),
6342 Reason => PE_Explicit_Raise));
6347 -- Check for calling a function with OUT or IN OUT parameter when the
6348 -- calling context (us right now) is not Ada 2012, so does not allow
6349 -- OUT or IN OUT parameters in function calls. Functions declared in
6350 -- a predefined unit are OK, as they may be called indirectly from a
6351 -- user-declared instantiation.
6353 if Ada_Version < Ada_2012
6354 and then Ekind (Nam) = E_Function
6355 and then Has_Out_Or_In_Out_Parameter (Nam)
6356 and then not In_Predefined_Unit (Nam)
6358 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6359 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6362 -- Check the dimensions of the actuals in the call. For function calls,
6363 -- propagate the dimensions from the returned type to N.
6365 Analyze_Dimension_Call (N, Nam);
6367 -- All done, evaluate call and deal with elaboration issues
6370 Check_Elab_Call (N);
6372 -- In GNATprove mode, expansion is disabled, but we want to inline some
6373 -- subprograms to facilitate formal verification. Indirect calls through
6374 -- a subprogram type or within a generic cannot be inlined. Inlining is
6375 -- performed only for calls subject to SPARK_Mode on.
6378 and then SPARK_Mode = On
6379 and then Is_Overloadable (Nam)
6380 and then not Inside_A_Generic
6382 Nam_UA := Ultimate_Alias (Nam);
6383 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6385 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6386 Body_Id := Corresponding_Body (Nam_Decl);
6388 -- Nothing to do if the subprogram is not eligible for inlining in
6391 if not Is_Inlined_Always (Nam_UA)
6392 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6396 -- Calls cannot be inlined inside assertions, as GNATprove treats
6397 -- assertions as logic expressions.
6399 elsif In_Assertion_Expr /= 0 then
6400 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6401 Error_Msg_N ("\call appears in assertion expression", N);
6402 Set_Is_Inlined_Always (Nam_UA, False);
6404 -- Calls cannot be inlined inside default expressions
6406 elsif In_Default_Expr then
6407 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6408 Error_Msg_N ("\call appears in default expression", N);
6409 Set_Is_Inlined_Always (Nam_UA, False);
6411 -- Inlining should not be performed during pre-analysis
6413 elsif Full_Analysis then
6415 -- With the one-pass inlining technique, a call cannot be
6416 -- inlined if the corresponding body has not been seen yet.
6418 if No (Body_Id) then
6420 ("?no contextual analysis of & (body not seen yet)",
6422 Set_Is_Inlined_Always (Nam_UA, False);
6424 -- Nothing to do if there is no body to inline, indicating that
6425 -- the subprogram is not suitable for inlining in GNATprove
6428 elsif No (Body_To_Inline (Nam_Decl)) then
6431 -- Calls cannot be inlined inside potentially unevaluated
6432 -- expressions, as this would create complex actions inside
6433 -- expressions, that are not handled by GNATprove.
6435 elsif Is_Potentially_Unevaluated (N) then
6436 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6438 ("\call appears in potentially unevaluated context", N);
6439 Set_Is_Inlined_Always (Nam_UA, False);
6441 -- Otherwise, inline the call
6444 Expand_Inlined_Call (N, Nam_UA, Nam);
6450 Warn_On_Overlapping_Actuals (Nam, N);
6453 -----------------------------
6454 -- Resolve_Case_Expression --
6455 -----------------------------
6457 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6462 Alt := First (Alternatives (N));
6463 while Present (Alt) loop
6464 Resolve (Expression (Alt), Typ);
6468 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6469 -- dynamically tagged must be known statically.
6471 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
6472 Alt := First (Alternatives (N));
6473 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
6475 while Present (Alt) loop
6476 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
6477 Error_Msg_N ("all or none of the dependent expressions "
6478 & "can be dynamically tagged", N);
6486 Eval_Case_Expression (N);
6487 end Resolve_Case_Expression;
6489 -------------------------------
6490 -- Resolve_Character_Literal --
6491 -------------------------------
6493 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6494 B_Typ : constant Entity_Id := Base_Type (Typ);
6498 -- Verify that the character does belong to the type of the context
6500 Set_Etype (N, B_Typ);
6501 Eval_Character_Literal (N);
6503 -- Wide_Wide_Character literals must always be defined, since the set
6504 -- of wide wide character literals is complete, i.e. if a character
6505 -- literal is accepted by the parser, then it is OK for wide wide
6506 -- character (out of range character literals are rejected).
6508 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6511 -- Always accept character literal for type Any_Character, which
6512 -- occurs in error situations and in comparisons of literals, both
6513 -- of which should accept all literals.
6515 elsif B_Typ = Any_Character then
6518 -- For Standard.Character or a type derived from it, check that the
6519 -- literal is in range.
6521 elsif Root_Type (B_Typ) = Standard_Character then
6522 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6526 -- For Standard.Wide_Character or a type derived from it, check that the
6527 -- literal is in range.
6529 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6530 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6534 -- For Standard.Wide_Wide_Character or a type derived from it, we
6535 -- know the literal is in range, since the parser checked.
6537 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6540 -- If the entity is already set, this has already been resolved in a
6541 -- generic context, or comes from expansion. Nothing else to do.
6543 elsif Present (Entity (N)) then
6546 -- Otherwise we have a user defined character type, and we can use the
6547 -- standard visibility mechanisms to locate the referenced entity.
6550 C := Current_Entity (N);
6551 while Present (C) loop
6552 if Etype (C) = B_Typ then
6553 Set_Entity_With_Checks (N, C);
6554 Generate_Reference (C, N);
6562 -- If we fall through, then the literal does not match any of the
6563 -- entries of the enumeration type. This isn't just a constraint error
6564 -- situation, it is an illegality (see RM 4.2).
6567 ("character not defined for }", N, First_Subtype (B_Typ));
6568 end Resolve_Character_Literal;
6570 ---------------------------
6571 -- Resolve_Comparison_Op --
6572 ---------------------------
6574 -- Context requires a boolean type, and plays no role in resolution.
6575 -- Processing identical to that for equality operators. The result type is
6576 -- the base type, which matters when pathological subtypes of booleans with
6577 -- limited ranges are used.
6579 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6580 L : constant Node_Id := Left_Opnd (N);
6581 R : constant Node_Id := Right_Opnd (N);
6585 -- If this is an intrinsic operation which is not predefined, use the
6586 -- types of its declared arguments to resolve the possibly overloaded
6587 -- operands. Otherwise the operands are unambiguous and specify the
6590 if Scope (Entity (N)) /= Standard_Standard then
6591 T := Etype (First_Entity (Entity (N)));
6594 T := Find_Unique_Type (L, R);
6596 if T = Any_Fixed then
6597 T := Unique_Fixed_Point_Type (L);
6601 Set_Etype (N, Base_Type (Typ));
6602 Generate_Reference (T, N, ' ');
6604 -- Skip remaining processing if already set to Any_Type
6606 if T = Any_Type then
6610 -- Deal with other error cases
6612 if T = Any_String or else
6613 T = Any_Composite or else
6616 if T = Any_Character then
6617 Ambiguous_Character (L);
6619 Error_Msg_N ("ambiguous operands for comparison", N);
6622 Set_Etype (N, Any_Type);
6626 -- Resolve the operands if types OK
6630 Check_Unset_Reference (L);
6631 Check_Unset_Reference (R);
6632 Generate_Operator_Reference (N, T);
6633 Check_Low_Bound_Tested (N);
6635 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6636 -- types or array types except String.
6638 if Is_Boolean_Type (T) then
6639 Check_SPARK_05_Restriction
6640 ("comparison is not defined on Boolean type", N);
6642 elsif Is_Array_Type (T)
6643 and then Base_Type (T) /= Standard_String
6645 Check_SPARK_05_Restriction
6646 ("comparison is not defined on array types other than String", N);
6649 -- Check comparison on unordered enumeration
6651 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6652 Error_Msg_Sloc := Sloc (Etype (L));
6654 ("comparison on unordered enumeration type& declared#?U?",
6658 -- Evaluate the relation (note we do this after the above check since
6659 -- this Eval call may change N to True/False.
6661 Analyze_Dimension (N);
6662 Eval_Relational_Op (N);
6663 end Resolve_Comparison_Op;
6665 -----------------------------------------
6666 -- Resolve_Discrete_Subtype_Indication --
6667 -----------------------------------------
6669 procedure Resolve_Discrete_Subtype_Indication
6677 Analyze (Subtype_Mark (N));
6678 S := Entity (Subtype_Mark (N));
6680 if Nkind (Constraint (N)) /= N_Range_Constraint then
6681 Error_Msg_N ("expect range constraint for discrete type", N);
6682 Set_Etype (N, Any_Type);
6685 R := Range_Expression (Constraint (N));
6693 if Base_Type (S) /= Base_Type (Typ) then
6695 ("expect subtype of }", N, First_Subtype (Typ));
6697 -- Rewrite the constraint as a range of Typ
6698 -- to allow compilation to proceed further.
6701 Rewrite (Low_Bound (R),
6702 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6703 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6704 Attribute_Name => Name_First));
6705 Rewrite (High_Bound (R),
6706 Make_Attribute_Reference (Sloc (High_Bound (R)),
6707 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6708 Attribute_Name => Name_First));
6712 Set_Etype (N, Etype (R));
6714 -- Additionally, we must check that the bounds are compatible
6715 -- with the given subtype, which might be different from the
6716 -- type of the context.
6718 Apply_Range_Check (R, S);
6720 -- ??? If the above check statically detects a Constraint_Error
6721 -- it replaces the offending bound(s) of the range R with a
6722 -- Constraint_Error node. When the itype which uses these bounds
6723 -- is frozen the resulting call to Duplicate_Subexpr generates
6724 -- a new temporary for the bounds.
6726 -- Unfortunately there are other itypes that are also made depend
6727 -- on these bounds, so when Duplicate_Subexpr is called they get
6728 -- a forward reference to the newly created temporaries and Gigi
6729 -- aborts on such forward references. This is probably sign of a
6730 -- more fundamental problem somewhere else in either the order of
6731 -- itype freezing or the way certain itypes are constructed.
6733 -- To get around this problem we call Remove_Side_Effects right
6734 -- away if either bounds of R are a Constraint_Error.
6737 L : constant Node_Id := Low_Bound (R);
6738 H : constant Node_Id := High_Bound (R);
6741 if Nkind (L) = N_Raise_Constraint_Error then
6742 Remove_Side_Effects (L);
6745 if Nkind (H) = N_Raise_Constraint_Error then
6746 Remove_Side_Effects (H);
6750 Check_Unset_Reference (Low_Bound (R));
6751 Check_Unset_Reference (High_Bound (R));
6754 end Resolve_Discrete_Subtype_Indication;
6756 -------------------------
6757 -- Resolve_Entity_Name --
6758 -------------------------
6760 -- Used to resolve identifiers and expanded names
6762 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6763 function Is_Assignment_Or_Object_Expression
6765 Expr : Node_Id) return Boolean;
6766 -- Determine whether node Context denotes an assignment statement or an
6767 -- object declaration whose expression is node Expr.
6769 function Is_OK_Volatile_Context
6771 Obj_Ref : Node_Id) return Boolean;
6772 -- Determine whether node Context denotes a "non-interfering context"
6773 -- (as defined in SPARK RM 7.1.3(13)) where volatile reference Obj_Ref
6774 -- can safely reside.
6776 ----------------------------------------
6777 -- Is_Assignment_Or_Object_Expression --
6778 ----------------------------------------
6780 function Is_Assignment_Or_Object_Expression
6782 Expr : Node_Id) return Boolean
6785 if Nkind_In (Context, N_Assignment_Statement,
6786 N_Object_Declaration)
6787 and then Expression (Context) = Expr
6791 -- Check whether a construct that yields a name is the expression of
6792 -- an assignment statement or an object declaration.
6794 elsif (Nkind_In (Context, N_Attribute_Reference,
6795 N_Explicit_Dereference,
6796 N_Indexed_Component,
6797 N_Selected_Component,
6799 and then Prefix (Context) = Expr)
6801 (Nkind_In (Context, N_Type_Conversion,
6802 N_Unchecked_Type_Conversion)
6803 and then Expression (Context) = Expr)
6806 Is_Assignment_Or_Object_Expression
6807 (Context => Parent (Context),
6810 -- Otherwise the context is not an assignment statement or an object
6816 end Is_Assignment_Or_Object_Expression;
6818 ----------------------------
6819 -- Is_OK_Volatile_Context --
6820 ----------------------------
6822 function Is_OK_Volatile_Context
6824 Obj_Ref : Node_Id) return Boolean
6826 function Within_Check (Nod : Node_Id) return Boolean;
6827 -- Determine whether an arbitrary node appears in a check node
6829 function Within_Procedure_Call (Nod : Node_Id) return Boolean;
6830 -- Determine whether an arbitrary node appears in a procedure call
6836 function Within_Check (Nod : Node_Id) return Boolean is
6840 -- Climb the parent chain looking for a check node
6843 while Present (Par) loop
6844 if Nkind (Par) in N_Raise_xxx_Error then
6847 -- Prevent the search from going too far
6849 elsif Is_Body_Or_Package_Declaration (Par) then
6853 Par := Parent (Par);
6859 ---------------------------
6860 -- Within_Procedure_Call --
6861 ---------------------------
6863 function Within_Procedure_Call (Nod : Node_Id) return Boolean is
6867 -- Climb the parent chain looking for a procedure call
6870 while Present (Par) loop
6871 if Nkind (Par) = N_Procedure_Call_Statement then
6874 -- Prevent the search from going too far
6876 elsif Is_Body_Or_Package_Declaration (Par) then
6880 Par := Parent (Par);
6884 end Within_Procedure_Call;
6886 -- Start of processing for Is_OK_Volatile_Context
6889 -- The volatile object appears on either side of an assignment
6891 if Nkind (Context) = N_Assignment_Statement then
6894 -- The volatile object is part of the initialization expression of
6895 -- another object. Ensure that the climb of the parent chain came
6896 -- from the expression side and not from the name side.
6898 elsif Nkind (Context) = N_Object_Declaration
6899 and then Present (Expression (Context))
6900 and then Expression (Context) = Obj_Ref
6904 -- The volatile object appears as an actual parameter in a call to an
6905 -- instance of Unchecked_Conversion whose result is renamed.
6907 elsif Nkind (Context) = N_Function_Call
6908 and then Is_Unchecked_Conversion_Instance (Entity (Name (Context)))
6909 and then Nkind (Parent (Context)) = N_Object_Renaming_Declaration
6913 -- The volatile object appears as the prefix of a name occurring
6914 -- in a non-interfering context.
6916 elsif Nkind_In (Context, N_Attribute_Reference,
6917 N_Explicit_Dereference,
6918 N_Indexed_Component,
6919 N_Selected_Component,
6921 and then Prefix (Context) = Obj_Ref
6922 and then Is_OK_Volatile_Context
6923 (Context => Parent (Context),
6928 -- The volatile object appears as the expression of a type conversion
6929 -- occurring in a non-interfering context.
6931 elsif Nkind_In (Context, N_Type_Conversion,
6932 N_Unchecked_Type_Conversion)
6933 and then Expression (Context) = Obj_Ref
6934 and then Is_OK_Volatile_Context
6935 (Context => Parent (Context),
6940 -- Allow references to volatile objects in various checks. This is
6941 -- not a direct SPARK 2014 requirement.
6943 elsif Within_Check (Context) then
6946 -- Assume that references to effectively volatile objects that appear
6947 -- as actual parameters in a procedure call are always legal. A full
6948 -- legality check is done when the actuals are resolved.
6950 elsif Within_Procedure_Call (Context) then
6953 -- Otherwise the context is not suitable for an effectively volatile
6959 end Is_OK_Volatile_Context;
6963 E : constant Entity_Id := Entity (N);
6966 -- Start of processing for Resolve_Entity_Name
6969 -- If garbage from errors, set to Any_Type and return
6971 if No (E) and then Total_Errors_Detected /= 0 then
6972 Set_Etype (N, Any_Type);
6976 -- Replace named numbers by corresponding literals. Note that this is
6977 -- the one case where Resolve_Entity_Name must reset the Etype, since
6978 -- it is currently marked as universal.
6980 if Ekind (E) = E_Named_Integer then
6982 Eval_Named_Integer (N);
6984 elsif Ekind (E) = E_Named_Real then
6986 Eval_Named_Real (N);
6988 -- For enumeration literals, we need to make sure that a proper style
6989 -- check is done, since such literals are overloaded, and thus we did
6990 -- not do a style check during the first phase of analysis.
6992 elsif Ekind (E) = E_Enumeration_Literal then
6993 Set_Entity_With_Checks (N, E);
6994 Eval_Entity_Name (N);
6996 -- Case of subtype name appearing as an operand in expression
6998 elsif Is_Type (E) then
7000 -- Allow use of subtype if it is a concurrent type where we are
7001 -- currently inside the body. This will eventually be expanded into a
7002 -- call to Self (for tasks) or _object (for protected objects). Any
7003 -- other use of a subtype is invalid.
7005 if Is_Concurrent_Type (E)
7006 and then In_Open_Scopes (E)
7010 -- Any other use is an error
7014 ("invalid use of subtype mark in expression or call", N);
7017 -- Check discriminant use if entity is discriminant in current scope,
7018 -- i.e. discriminant of record or concurrent type currently being
7019 -- analyzed. Uses in corresponding body are unrestricted.
7021 elsif Ekind (E) = E_Discriminant
7022 and then Scope (E) = Current_Scope
7023 and then not Has_Completion (Current_Scope)
7025 Check_Discriminant_Use (N);
7027 -- A parameterless generic function cannot appear in a context that
7028 -- requires resolution.
7030 elsif Ekind (E) = E_Generic_Function then
7031 Error_Msg_N ("illegal use of generic function", N);
7033 -- In Ada 83 an OUT parameter cannot be read
7035 elsif Ekind (E) = E_Out_Parameter
7036 and then (Nkind (Parent (N)) in N_Op
7037 or else Nkind (Parent (N)) = N_Explicit_Dereference
7038 or else Is_Assignment_Or_Object_Expression
7039 (Context => Parent (N),
7042 if Ada_Version = Ada_83 then
7043 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7045 -- An effectively volatile OUT parameter cannot be read
7046 -- (SPARK RM 7.1.3(11)).
7048 elsif SPARK_Mode = On
7049 and then Is_Effectively_Volatile (E)
7051 Error_Msg_N ("illegal reading of volatile OUT parameter", N);
7054 -- In all other cases, just do the possible static evaluation
7057 -- A deferred constant that appears in an expression must have a
7058 -- completion, unless it has been removed by in-place expansion of
7061 if Ekind (E) = E_Constant
7062 and then Comes_From_Source (E)
7063 and then No (Constant_Value (E))
7064 and then Is_Frozen (Etype (E))
7065 and then not In_Spec_Expression
7066 and then not Is_Imported (E)
7068 if No_Initialization (Parent (E))
7069 or else (Present (Full_View (E))
7070 and then No_Initialization (Parent (Full_View (E))))
7075 "deferred constant is frozen before completion", N);
7079 Eval_Entity_Name (N);
7084 -- When the entity appears in a parameter association, retrieve the
7085 -- related subprogram call.
7087 if Nkind (Par) = N_Parameter_Association then
7088 Par := Parent (Par);
7091 -- The following checks are only relevant when SPARK_Mode is on as they
7092 -- are not standard Ada legality rules. An effectively volatile object
7093 -- subject to enabled properties Async_Writers or Effective_Reads must
7094 -- appear in a specific context.
7097 and then Is_Object (E)
7098 and then Is_Effectively_Volatile (E)
7099 and then (Async_Writers_Enabled (E)
7100 or else Effective_Reads_Enabled (E))
7101 and then Comes_From_Source (N)
7103 -- The effectively volatile objects appears in a "non-interfering
7104 -- context" as defined in SPARK RM 7.1.3(13).
7106 if Is_OK_Volatile_Context (Par, N) then
7109 -- Otherwise the context causes a side effect with respect to the
7110 -- effectively volatile object.
7114 ("volatile object cannot appear in this context "
7115 & "(SPARK RM 7.1.3(13))", N);
7119 -- A Ghost entity must appear in a specific context
7121 if Is_Ghost_Entity (E) and then Comes_From_Source (N) then
7122 Check_Ghost_Context (E, N);
7125 -- In SPARK mode, need to check possible elaboration issues
7127 if SPARK_Mode = On and then Ekind (E) = E_Variable then
7128 Check_Elab_Call (N);
7130 end Resolve_Entity_Name;
7136 procedure Resolve_Entry (Entry_Name : Node_Id) is
7137 Loc : constant Source_Ptr := Sloc (Entry_Name);
7145 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7146 -- If the bounds of the entry family being called depend on task
7147 -- discriminants, build a new index subtype where a discriminant is
7148 -- replaced with the value of the discriminant of the target task.
7149 -- The target task is the prefix of the entry name in the call.
7151 -----------------------
7152 -- Actual_Index_Type --
7153 -----------------------
7155 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7156 Typ : constant Entity_Id := Entry_Index_Type (E);
7157 Tsk : constant Entity_Id := Scope (E);
7158 Lo : constant Node_Id := Type_Low_Bound (Typ);
7159 Hi : constant Node_Id := Type_High_Bound (Typ);
7162 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7163 -- If the bound is given by a discriminant, replace with a reference
7164 -- to the discriminant of the same name in the target task. If the
7165 -- entry name is the target of a requeue statement and the entry is
7166 -- in the current protected object, the bound to be used is the
7167 -- discriminal of the object (see Apply_Range_Checks for details of
7168 -- the transformation).
7170 -----------------------------
7171 -- Actual_Discriminant_Ref --
7172 -----------------------------
7174 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7175 Typ : constant Entity_Id := Etype (Bound);
7179 Remove_Side_Effects (Bound);
7181 if not Is_Entity_Name (Bound)
7182 or else Ekind (Entity (Bound)) /= E_Discriminant
7186 elsif Is_Protected_Type (Tsk)
7187 and then In_Open_Scopes (Tsk)
7188 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7190 -- Note: here Bound denotes a discriminant of the corresponding
7191 -- record type tskV, whose discriminal is a formal of the
7192 -- init-proc tskVIP. What we want is the body discriminal,
7193 -- which is associated to the discriminant of the original
7194 -- concurrent type tsk.
7196 return New_Occurrence_Of
7197 (Find_Body_Discriminal (Entity (Bound)), Loc);
7201 Make_Selected_Component (Loc,
7202 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7203 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7208 end Actual_Discriminant_Ref;
7210 -- Start of processing for Actual_Index_Type
7213 if not Has_Discriminants (Tsk)
7214 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7216 return Entry_Index_Type (E);
7219 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7220 Set_Etype (New_T, Base_Type (Typ));
7221 Set_Size_Info (New_T, Typ);
7222 Set_RM_Size (New_T, RM_Size (Typ));
7223 Set_Scalar_Range (New_T,
7224 Make_Range (Sloc (Entry_Name),
7225 Low_Bound => Actual_Discriminant_Ref (Lo),
7226 High_Bound => Actual_Discriminant_Ref (Hi)));
7230 end Actual_Index_Type;
7232 -- Start of processing of Resolve_Entry
7235 -- Find name of entry being called, and resolve prefix of name with its
7236 -- own type. The prefix can be overloaded, and the name and signature of
7237 -- the entry must be taken into account.
7239 if Nkind (Entry_Name) = N_Indexed_Component then
7241 -- Case of dealing with entry family within the current tasks
7243 E_Name := Prefix (Entry_Name);
7246 E_Name := Entry_Name;
7249 if Is_Entity_Name (E_Name) then
7251 -- Entry call to an entry (or entry family) in the current task. This
7252 -- is legal even though the task will deadlock. Rewrite as call to
7255 -- This can also be a call to an entry in an enclosing task. If this
7256 -- is a single task, we have to retrieve its name, because the scope
7257 -- of the entry is the task type, not the object. If the enclosing
7258 -- task is a task type, the identity of the task is given by its own
7261 -- Finally this can be a requeue on an entry of the same task or
7262 -- protected object.
7264 S := Scope (Entity (E_Name));
7266 for J in reverse 0 .. Scope_Stack.Last loop
7267 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7268 and then not Comes_From_Source (S)
7270 -- S is an enclosing task or protected object. The concurrent
7271 -- declaration has been converted into a type declaration, and
7272 -- the object itself has an object declaration that follows
7273 -- the type in the same declarative part.
7275 Tsk := Next_Entity (S);
7276 while Etype (Tsk) /= S loop
7283 elsif S = Scope_Stack.Table (J).Entity then
7285 -- Call to current task. Will be transformed into call to Self
7293 Make_Selected_Component (Loc,
7294 Prefix => New_Occurrence_Of (S, Loc),
7296 New_Occurrence_Of (Entity (E_Name), Loc));
7297 Rewrite (E_Name, New_N);
7300 elsif Nkind (Entry_Name) = N_Selected_Component
7301 and then Is_Overloaded (Prefix (Entry_Name))
7303 -- Use the entry name (which must be unique at this point) to find
7304 -- the prefix that returns the corresponding task/protected type.
7307 Pref : constant Node_Id := Prefix (Entry_Name);
7308 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7313 Get_First_Interp (Pref, I, It);
7314 while Present (It.Typ) loop
7315 if Scope (Ent) = It.Typ then
7316 Set_Etype (Pref, It.Typ);
7320 Get_Next_Interp (I, It);
7325 if Nkind (Entry_Name) = N_Selected_Component then
7326 Resolve (Prefix (Entry_Name));
7328 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7329 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7330 Resolve (Prefix (Prefix (Entry_Name)));
7331 Index := First (Expressions (Entry_Name));
7332 Resolve (Index, Entry_Index_Type (Nam));
7334 -- Up to this point the expression could have been the actual in a
7335 -- simple entry call, and be given by a named association.
7337 if Nkind (Index) = N_Parameter_Association then
7338 Error_Msg_N ("expect expression for entry index", Index);
7340 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7345 ------------------------
7346 -- Resolve_Entry_Call --
7347 ------------------------
7349 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7350 Entry_Name : constant Node_Id := Name (N);
7351 Loc : constant Source_Ptr := Sloc (Entry_Name);
7353 First_Named : Node_Id;
7360 -- We kill all checks here, because it does not seem worth the effort to
7361 -- do anything better, an entry call is a big operation.
7365 -- Processing of the name is similar for entry calls and protected
7366 -- operation calls. Once the entity is determined, we can complete
7367 -- the resolution of the actuals.
7369 -- The selector may be overloaded, in the case of a protected object
7370 -- with overloaded functions. The type of the context is used for
7373 if Nkind (Entry_Name) = N_Selected_Component
7374 and then Is_Overloaded (Selector_Name (Entry_Name))
7375 and then Typ /= Standard_Void_Type
7382 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7383 while Present (It.Typ) loop
7384 if Covers (Typ, It.Typ) then
7385 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7386 Set_Etype (Entry_Name, It.Typ);
7388 Generate_Reference (It.Typ, N, ' ');
7391 Get_Next_Interp (I, It);
7396 Resolve_Entry (Entry_Name);
7398 if Nkind (Entry_Name) = N_Selected_Component then
7400 -- Simple entry call
7402 Nam := Entity (Selector_Name (Entry_Name));
7403 Obj := Prefix (Entry_Name);
7404 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7406 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7408 -- Call to member of entry family
7410 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7411 Obj := Prefix (Prefix (Entry_Name));
7412 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7415 -- We cannot in general check the maximum depth of protected entry calls
7416 -- at compile time. But we can tell that any protected entry call at all
7417 -- violates a specified nesting depth of zero.
7419 if Is_Protected_Type (Scope (Nam)) then
7420 Check_Restriction (Max_Entry_Queue_Length, N);
7423 -- Use context type to disambiguate a protected function that can be
7424 -- called without actuals and that returns an array type, and where the
7425 -- argument list may be an indexing of the returned value.
7427 if Ekind (Nam) = E_Function
7428 and then Needs_No_Actuals (Nam)
7429 and then Present (Parameter_Associations (N))
7431 ((Is_Array_Type (Etype (Nam))
7432 and then Covers (Typ, Component_Type (Etype (Nam))))
7434 or else (Is_Access_Type (Etype (Nam))
7435 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7439 Component_Type (Designated_Type (Etype (Nam))))))
7442 Index_Node : Node_Id;
7446 Make_Indexed_Component (Loc,
7448 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7449 Expressions => Parameter_Associations (N));
7451 -- Since we are correcting a node classification error made by the
7452 -- parser, we call Replace rather than Rewrite.
7454 Replace (N, Index_Node);
7455 Set_Etype (Prefix (N), Etype (Nam));
7457 Resolve_Indexed_Component (N, Typ);
7462 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7463 and then Present (PPC_Wrapper (Nam))
7464 and then Current_Scope /= PPC_Wrapper (Nam)
7466 -- Rewrite as call to the precondition wrapper, adding the task
7467 -- object to the list of actuals. If the call is to a member of an
7468 -- entry family, include the index as well.
7472 New_Actuals : List_Id;
7475 New_Actuals := New_List (Obj);
7477 if Nkind (Entry_Name) = N_Indexed_Component then
7478 Append_To (New_Actuals,
7479 New_Copy_Tree (First (Expressions (Entry_Name))));
7482 Append_List (Parameter_Associations (N), New_Actuals);
7484 Make_Procedure_Call_Statement (Loc,
7486 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
7487 Parameter_Associations => New_Actuals);
7488 Rewrite (N, New_Call);
7490 -- Preanalyze and resolve new call. Current procedure is called
7491 -- from Resolve_Call, after which expansion will take place.
7493 Preanalyze_And_Resolve (N);
7498 -- The operation name may have been overloaded. Order the actuals
7499 -- according to the formals of the resolved entity, and set the return
7500 -- type to that of the operation.
7503 Normalize_Actuals (N, Nam, False, Norm_OK);
7504 pragma Assert (Norm_OK);
7505 Set_Etype (N, Etype (Nam));
7508 Resolve_Actuals (N, Nam);
7509 Check_Internal_Protected_Use (N, Nam);
7511 -- Create a call reference to the entry
7513 Generate_Reference (Nam, Entry_Name, 's');
7515 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7516 Check_Potentially_Blocking_Operation (N);
7519 -- Verify that a procedure call cannot masquerade as an entry
7520 -- call where an entry call is expected.
7522 if Ekind (Nam) = E_Procedure then
7523 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7524 and then N = Entry_Call_Statement (Parent (N))
7526 Error_Msg_N ("entry call required in select statement", N);
7528 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7529 and then N = Triggering_Statement (Parent (N))
7531 Error_Msg_N ("triggering statement cannot be procedure call", N);
7533 elsif Ekind (Scope (Nam)) = E_Task_Type
7534 and then not In_Open_Scopes (Scope (Nam))
7536 Error_Msg_N ("task has no entry with this name", Entry_Name);
7540 -- After resolution, entry calls and protected procedure calls are
7541 -- changed into entry calls, for expansion. The structure of the node
7542 -- does not change, so it can safely be done in place. Protected
7543 -- function calls must keep their structure because they are
7546 if Ekind (Nam) /= E_Function then
7548 -- A protected operation that is not a function may modify the
7549 -- corresponding object, and cannot apply to a constant. If this
7550 -- is an internal call, the prefix is the type itself.
7552 if Is_Protected_Type (Scope (Nam))
7553 and then not Is_Variable (Obj)
7554 and then (not Is_Entity_Name (Obj)
7555 or else not Is_Type (Entity (Obj)))
7558 ("prefix of protected procedure or entry call must be variable",
7562 Actuals := Parameter_Associations (N);
7563 First_Named := First_Named_Actual (N);
7566 Make_Entry_Call_Statement (Loc,
7568 Parameter_Associations => Actuals));
7570 Set_First_Named_Actual (N, First_Named);
7571 Set_Analyzed (N, True);
7573 -- Protected functions can return on the secondary stack, in which
7574 -- case we must trigger the transient scope mechanism.
7576 elsif Expander_Active
7577 and then Requires_Transient_Scope (Etype (Nam))
7579 Establish_Transient_Scope (N, Sec_Stack => True);
7581 end Resolve_Entry_Call;
7583 -------------------------
7584 -- Resolve_Equality_Op --
7585 -------------------------
7587 -- Both arguments must have the same type, and the boolean context does
7588 -- not participate in the resolution. The first pass verifies that the
7589 -- interpretation is not ambiguous, and the type of the left argument is
7590 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7591 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7592 -- though they carry a single (universal) type. Diagnose this case here.
7594 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7595 L : constant Node_Id := Left_Opnd (N);
7596 R : constant Node_Id := Right_Opnd (N);
7597 T : Entity_Id := Find_Unique_Type (L, R);
7599 procedure Check_If_Expression (Cond : Node_Id);
7600 -- The resolution rule for if expressions requires that each such must
7601 -- have a unique type. This means that if several dependent expressions
7602 -- are of a non-null anonymous access type, and the context does not
7603 -- impose an expected type (as can be the case in an equality operation)
7604 -- the expression must be rejected.
7606 procedure Explain_Redundancy (N : Node_Id);
7607 -- Attempt to explain the nature of a redundant comparison with True. If
7608 -- the expression N is too complex, this routine issues a general error
7611 function Find_Unique_Access_Type return Entity_Id;
7612 -- In the case of allocators and access attributes, the context must
7613 -- provide an indication of the specific access type to be used. If
7614 -- one operand is of such a "generic" access type, check whether there
7615 -- is a specific visible access type that has the same designated type.
7616 -- This is semantically dubious, and of no interest to any real code,
7617 -- but c48008a makes it all worthwhile.
7619 -------------------------
7620 -- Check_If_Expression --
7621 -------------------------
7623 procedure Check_If_Expression (Cond : Node_Id) is
7624 Then_Expr : Node_Id;
7625 Else_Expr : Node_Id;
7628 if Nkind (Cond) = N_If_Expression then
7629 Then_Expr := Next (First (Expressions (Cond)));
7630 Else_Expr := Next (Then_Expr);
7632 if Nkind (Then_Expr) /= N_Null
7633 and then Nkind (Else_Expr) /= N_Null
7635 Error_Msg_N ("cannot determine type of if expression", Cond);
7638 end Check_If_Expression;
7640 ------------------------
7641 -- Explain_Redundancy --
7642 ------------------------
7644 procedure Explain_Redundancy (N : Node_Id) is
7652 -- Strip the operand down to an entity
7655 if Nkind (Val) = N_Selected_Component then
7656 Val := Selector_Name (Val);
7662 -- The construct denotes an entity
7664 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7665 Val_Id := Entity (Val);
7667 -- Do not generate an error message when the comparison is done
7668 -- against the enumeration literal Standard.True.
7670 if Ekind (Val_Id) /= E_Enumeration_Literal then
7672 -- Build a customized error message
7675 Add_Str_To_Name_Buffer ("?r?");
7677 if Ekind (Val_Id) = E_Component then
7678 Add_Str_To_Name_Buffer ("component ");
7680 elsif Ekind (Val_Id) = E_Constant then
7681 Add_Str_To_Name_Buffer ("constant ");
7683 elsif Ekind (Val_Id) = E_Discriminant then
7684 Add_Str_To_Name_Buffer ("discriminant ");
7686 elsif Is_Formal (Val_Id) then
7687 Add_Str_To_Name_Buffer ("parameter ");
7689 elsif Ekind (Val_Id) = E_Variable then
7690 Add_Str_To_Name_Buffer ("variable ");
7693 Add_Str_To_Name_Buffer ("& is always True!");
7696 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7699 -- The construct is too complex to disect, issue a general message
7702 Error_Msg_N ("?r?expression is always True!", Val);
7704 end Explain_Redundancy;
7706 -----------------------------
7707 -- Find_Unique_Access_Type --
7708 -----------------------------
7710 function Find_Unique_Access_Type return Entity_Id is
7716 if Ekind_In (Etype (R), E_Allocator_Type,
7717 E_Access_Attribute_Type)
7719 Acc := Designated_Type (Etype (R));
7721 elsif Ekind_In (Etype (L), E_Allocator_Type,
7722 E_Access_Attribute_Type)
7724 Acc := Designated_Type (Etype (L));
7730 while S /= Standard_Standard loop
7731 E := First_Entity (S);
7732 while Present (E) loop
7734 and then Is_Access_Type (E)
7735 and then Ekind (E) /= E_Allocator_Type
7736 and then Designated_Type (E) = Base_Type (Acc)
7748 end Find_Unique_Access_Type;
7750 -- Start of processing for Resolve_Equality_Op
7753 Set_Etype (N, Base_Type (Typ));
7754 Generate_Reference (T, N, ' ');
7756 if T = Any_Fixed then
7757 T := Unique_Fixed_Point_Type (L);
7760 if T /= Any_Type then
7761 if T = Any_String or else
7762 T = Any_Composite or else
7765 if T = Any_Character then
7766 Ambiguous_Character (L);
7768 Error_Msg_N ("ambiguous operands for equality", N);
7771 Set_Etype (N, Any_Type);
7774 elsif T = Any_Access
7775 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7777 T := Find_Unique_Access_Type;
7780 Error_Msg_N ("ambiguous operands for equality", N);
7781 Set_Etype (N, Any_Type);
7785 -- If expressions must have a single type, and if the context does
7786 -- not impose one the dependent expressions cannot be anonymous
7789 -- Why no similar processing for case expressions???
7791 elsif Ada_Version >= Ada_2012
7792 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7793 E_Anonymous_Access_Subprogram_Type)
7794 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7795 E_Anonymous_Access_Subprogram_Type)
7797 Check_If_Expression (L);
7798 Check_If_Expression (R);
7804 -- In SPARK, equality operators = and /= for array types other than
7805 -- String are only defined when, for each index position, the
7806 -- operands have equal static bounds.
7808 if Is_Array_Type (T) then
7810 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7811 -- operation if not needed.
7813 if Restriction_Check_Required (SPARK_05)
7814 and then Base_Type (T) /= Standard_String
7815 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7816 and then Etype (L) /= Any_Composite -- or else L in error
7817 and then Etype (R) /= Any_Composite -- or else R in error
7818 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7820 Check_SPARK_05_Restriction
7821 ("array types should have matching static bounds", N);
7825 -- If the unique type is a class-wide type then it will be expanded
7826 -- into a dispatching call to the predefined primitive. Therefore we
7827 -- check here for potential violation of such restriction.
7829 if Is_Class_Wide_Type (T) then
7830 Check_Restriction (No_Dispatching_Calls, N);
7833 if Warn_On_Redundant_Constructs
7834 and then Comes_From_Source (N)
7835 and then Comes_From_Source (R)
7836 and then Is_Entity_Name (R)
7837 and then Entity (R) = Standard_True
7839 Error_Msg_N -- CODEFIX
7840 ("?r?comparison with True is redundant!", N);
7841 Explain_Redundancy (Original_Node (R));
7844 Check_Unset_Reference (L);
7845 Check_Unset_Reference (R);
7846 Generate_Operator_Reference (N, T);
7847 Check_Low_Bound_Tested (N);
7849 -- If this is an inequality, it may be the implicit inequality
7850 -- created for a user-defined operation, in which case the corres-
7851 -- ponding equality operation is not intrinsic, and the operation
7852 -- cannot be constant-folded. Else fold.
7854 if Nkind (N) = N_Op_Eq
7855 or else Comes_From_Source (Entity (N))
7856 or else Ekind (Entity (N)) = E_Operator
7857 or else Is_Intrinsic_Subprogram
7858 (Corresponding_Equality (Entity (N)))
7860 Analyze_Dimension (N);
7861 Eval_Relational_Op (N);
7863 elsif Nkind (N) = N_Op_Ne
7864 and then Is_Abstract_Subprogram (Entity (N))
7866 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7869 -- Ada 2005: If one operand is an anonymous access type, convert the
7870 -- other operand to it, to ensure that the underlying types match in
7871 -- the back-end. Same for access_to_subprogram, and the conversion
7872 -- verifies that the types are subtype conformant.
7874 -- We apply the same conversion in the case one of the operands is a
7875 -- private subtype of the type of the other.
7877 -- Why the Expander_Active test here ???
7881 (Ekind_In (T, E_Anonymous_Access_Type,
7882 E_Anonymous_Access_Subprogram_Type)
7883 or else Is_Private_Type (T))
7885 if Etype (L) /= T then
7887 Make_Unchecked_Type_Conversion (Sloc (L),
7888 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7889 Expression => Relocate_Node (L)));
7890 Analyze_And_Resolve (L, T);
7893 if (Etype (R)) /= T then
7895 Make_Unchecked_Type_Conversion (Sloc (R),
7896 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7897 Expression => Relocate_Node (R)));
7898 Analyze_And_Resolve (R, T);
7902 end Resolve_Equality_Op;
7904 ----------------------------------
7905 -- Resolve_Explicit_Dereference --
7906 ----------------------------------
7908 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7909 Loc : constant Source_Ptr := Sloc (N);
7911 P : constant Node_Id := Prefix (N);
7914 -- The candidate prefix type, if overloaded
7920 Check_Fully_Declared_Prefix (Typ, P);
7923 -- A useful optimization: check whether the dereference denotes an
7924 -- element of a container, and if so rewrite it as a call to the
7925 -- corresponding Element function.
7927 -- Disabled for now, on advice of ARG. A more restricted form of the
7928 -- predicate might be acceptable ???
7930 -- if Is_Container_Element (N) then
7934 if Is_Overloaded (P) then
7936 -- Use the context type to select the prefix that has the correct
7937 -- designated type. Keep the first match, which will be the inner-
7940 Get_First_Interp (P, I, It);
7942 while Present (It.Typ) loop
7943 if Is_Access_Type (It.Typ)
7944 and then Covers (Typ, Designated_Type (It.Typ))
7950 -- Remove access types that do not match, but preserve access
7951 -- to subprogram interpretations, in case a further dereference
7952 -- is needed (see below).
7954 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
7958 Get_Next_Interp (I, It);
7961 if Present (P_Typ) then
7963 Set_Etype (N, Designated_Type (P_Typ));
7966 -- If no interpretation covers the designated type of the prefix,
7967 -- this is the pathological case where not all implementations of
7968 -- the prefix allow the interpretation of the node as a call. Now
7969 -- that the expected type is known, Remove other interpretations
7970 -- from prefix, rewrite it as a call, and resolve again, so that
7971 -- the proper call node is generated.
7973 Get_First_Interp (P, I, It);
7974 while Present (It.Typ) loop
7975 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
7979 Get_Next_Interp (I, It);
7983 Make_Function_Call (Loc,
7985 Make_Explicit_Dereference (Loc,
7987 Parameter_Associations => New_List);
7989 Save_Interps (N, New_N);
7991 Analyze_And_Resolve (N, Typ);
7995 -- If not overloaded, resolve P with its own type
8001 if Is_Access_Type (Etype (P)) then
8002 Apply_Access_Check (N);
8005 -- If the designated type is a packed unconstrained array type, and the
8006 -- explicit dereference is not in the context of an attribute reference,
8007 -- then we must compute and set the actual subtype, since it is needed
8008 -- by Gigi. The reason we exclude the attribute case is that this is
8009 -- handled fine by Gigi, and in fact we use such attributes to build the
8010 -- actual subtype. We also exclude generated code (which builds actual
8011 -- subtypes directly if they are needed).
8013 if Is_Array_Type (Etype (N))
8014 and then Is_Packed (Etype (N))
8015 and then not Is_Constrained (Etype (N))
8016 and then Nkind (Parent (N)) /= N_Attribute_Reference
8017 and then Comes_From_Source (N)
8019 Set_Etype (N, Get_Actual_Subtype (N));
8022 -- Note: No Eval processing is required for an explicit dereference,
8023 -- because such a name can never be static.
8025 end Resolve_Explicit_Dereference;
8027 -------------------------------------
8028 -- Resolve_Expression_With_Actions --
8029 -------------------------------------
8031 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8035 -- If N has no actions, and its expression has been constant folded,
8036 -- then rewrite N as just its expression. Note, we can't do this in
8037 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8038 -- Expression (N) to be expanded again.
8040 if Is_Empty_List (Actions (N))
8041 and then Compile_Time_Known_Value (Expression (N))
8043 Rewrite (N, Expression (N));
8045 end Resolve_Expression_With_Actions;
8047 ----------------------------------
8048 -- Resolve_Generalized_Indexing --
8049 ----------------------------------
8051 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8052 Indexing : constant Node_Id := Generalized_Indexing (N);
8058 -- In ASIS mode, propagate the information about the indexes back to
8059 -- to the original indexing node. The generalized indexing is either
8060 -- a function call, or a dereference of one. The actuals include the
8061 -- prefix of the original node, which is the container expression.
8064 Resolve (Indexing, Typ);
8065 Set_Etype (N, Etype (Indexing));
8066 Set_Is_Overloaded (N, False);
8069 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8071 Call := Prefix (Call);
8074 if Nkind (Call) = N_Function_Call then
8075 Indexes := Parameter_Associations (Call);
8076 Pref := Remove_Head (Indexes);
8077 Set_Expressions (N, Indexes);
8078 Set_Prefix (N, Pref);
8082 Rewrite (N, Indexing);
8085 end Resolve_Generalized_Indexing;
8087 ---------------------------
8088 -- Resolve_If_Expression --
8089 ---------------------------
8091 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8092 Condition : constant Node_Id := First (Expressions (N));
8093 Then_Expr : constant Node_Id := Next (Condition);
8094 Else_Expr : Node_Id := Next (Then_Expr);
8095 Else_Typ : Entity_Id;
8096 Then_Typ : Entity_Id;
8099 Resolve (Condition, Any_Boolean);
8100 Resolve (Then_Expr, Typ);
8101 Then_Typ := Etype (Then_Expr);
8103 -- When the "then" expression is of a scalar subtype different from the
8104 -- result subtype, then insert a conversion to ensure the generation of
8105 -- a constraint check. The same is done for the else part below, again
8106 -- comparing subtypes rather than base types.
8108 if Is_Scalar_Type (Then_Typ)
8109 and then Then_Typ /= Typ
8111 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8112 Analyze_And_Resolve (Then_Expr, Typ);
8115 -- If ELSE expression present, just resolve using the determined type
8117 if Present (Else_Expr) then
8118 Resolve (Else_Expr, Typ);
8119 Else_Typ := Etype (Else_Expr);
8121 if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
8122 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8123 Analyze_And_Resolve (Else_Expr, Typ);
8125 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8126 -- dynamically tagged must be known statically.
8128 elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8129 if Is_Dynamically_Tagged (Then_Expr) /=
8130 Is_Dynamically_Tagged (Else_Expr)
8132 Error_Msg_N ("all or none of the dependent expressions "
8133 & "can be dynamically tagged", N);
8137 -- If no ELSE expression is present, root type must be Standard.Boolean
8138 -- and we provide a Standard.True result converted to the appropriate
8139 -- Boolean type (in case it is a derived boolean type).
8141 elsif Root_Type (Typ) = Standard_Boolean then
8143 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8144 Analyze_And_Resolve (Else_Expr, Typ);
8145 Append_To (Expressions (N), Else_Expr);
8148 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8149 Append_To (Expressions (N), Error);
8153 Eval_If_Expression (N);
8154 end Resolve_If_Expression;
8156 -------------------------------
8157 -- Resolve_Indexed_Component --
8158 -------------------------------
8160 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8161 Name : constant Node_Id := Prefix (N);
8163 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8167 if Present (Generalized_Indexing (N)) then
8168 Resolve_Generalized_Indexing (N, Typ);
8172 if Is_Overloaded (Name) then
8174 -- Use the context type to select the prefix that yields the correct
8180 I1 : Interp_Index := 0;
8181 P : constant Node_Id := Prefix (N);
8182 Found : Boolean := False;
8185 Get_First_Interp (P, I, It);
8186 while Present (It.Typ) loop
8187 if (Is_Array_Type (It.Typ)
8188 and then Covers (Typ, Component_Type (It.Typ)))
8189 or else (Is_Access_Type (It.Typ)
8190 and then Is_Array_Type (Designated_Type (It.Typ))
8194 Component_Type (Designated_Type (It.Typ))))
8197 It := Disambiguate (P, I1, I, Any_Type);
8199 if It = No_Interp then
8200 Error_Msg_N ("ambiguous prefix for indexing", N);
8206 Array_Type := It.Typ;
8212 Array_Type := It.Typ;
8217 Get_Next_Interp (I, It);
8222 Array_Type := Etype (Name);
8225 Resolve (Name, Array_Type);
8226 Array_Type := Get_Actual_Subtype_If_Available (Name);
8228 -- If prefix is access type, dereference to get real array type.
8229 -- Note: we do not apply an access check because the expander always
8230 -- introduces an explicit dereference, and the check will happen there.
8232 if Is_Access_Type (Array_Type) then
8233 Array_Type := Designated_Type (Array_Type);
8236 -- If name was overloaded, set component type correctly now
8237 -- If a misplaced call to an entry family (which has no index types)
8238 -- return. Error will be diagnosed from calling context.
8240 if Is_Array_Type (Array_Type) then
8241 Set_Etype (N, Component_Type (Array_Type));
8246 Index := First_Index (Array_Type);
8247 Expr := First (Expressions (N));
8249 -- The prefix may have resolved to a string literal, in which case its
8250 -- etype has a special representation. This is only possible currently
8251 -- if the prefix is a static concatenation, written in functional
8254 if Ekind (Array_Type) = E_String_Literal_Subtype then
8255 Resolve (Expr, Standard_Positive);
8258 while Present (Index) and Present (Expr) loop
8259 Resolve (Expr, Etype (Index));
8260 Check_Unset_Reference (Expr);
8262 if Is_Scalar_Type (Etype (Expr)) then
8263 Apply_Scalar_Range_Check (Expr, Etype (Index));
8265 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8273 Analyze_Dimension (N);
8275 -- Do not generate the warning on suspicious index if we are analyzing
8276 -- package Ada.Tags; otherwise we will report the warning with the
8277 -- Prims_Ptr field of the dispatch table.
8279 if Scope (Etype (Prefix (N))) = Standard_Standard
8281 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8284 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8285 Eval_Indexed_Component (N);
8288 -- If the array type is atomic, and the component is not atomic, then
8289 -- this is worth a warning, since we have a situation where the access
8290 -- to the component may cause extra read/writes of the atomic array
8291 -- object, or partial word accesses, which could be unexpected.
8293 if Nkind (N) = N_Indexed_Component
8294 and then Is_Atomic_Ref_With_Address (N)
8295 and then not (Has_Atomic_Components (Array_Type)
8296 or else (Is_Entity_Name (Prefix (N))
8297 and then Has_Atomic_Components
8298 (Entity (Prefix (N)))))
8299 and then not Is_Atomic (Component_Type (Array_Type))
8302 ("??access to non-atomic component of atomic array", Prefix (N));
8304 ("??\may cause unexpected accesses to atomic object", Prefix (N));
8306 end Resolve_Indexed_Component;
8308 -----------------------------
8309 -- Resolve_Integer_Literal --
8310 -----------------------------
8312 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8315 Eval_Integer_Literal (N);
8316 end Resolve_Integer_Literal;
8318 --------------------------------
8319 -- Resolve_Intrinsic_Operator --
8320 --------------------------------
8322 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8323 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8328 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8329 -- If the operand is a literal, it cannot be the expression in a
8330 -- conversion. Use a qualified expression instead.
8332 ---------------------
8333 -- Convert_Operand --
8334 ---------------------
8336 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8337 Loc : constant Source_Ptr := Sloc (Opnd);
8341 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8343 Make_Qualified_Expression (Loc,
8344 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8345 Expression => Relocate_Node (Opnd));
8349 Res := Unchecked_Convert_To (Btyp, Opnd);
8353 end Convert_Operand;
8355 -- Start of processing for Resolve_Intrinsic_Operator
8358 -- We must preserve the original entity in a generic setting, so that
8359 -- the legality of the operation can be verified in an instance.
8361 if not Expander_Active then
8366 while Scope (Op) /= Standard_Standard loop
8368 pragma Assert (Present (Op));
8372 Set_Is_Overloaded (N, False);
8374 -- If the result or operand types are private, rewrite with unchecked
8375 -- conversions on the operands and the result, to expose the proper
8376 -- underlying numeric type.
8378 if Is_Private_Type (Typ)
8379 or else Is_Private_Type (Etype (Left_Opnd (N)))
8380 or else Is_Private_Type (Etype (Right_Opnd (N)))
8382 Arg1 := Convert_Operand (Left_Opnd (N));
8384 if Nkind (N) = N_Op_Expon then
8385 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8387 Arg2 := Convert_Operand (Right_Opnd (N));
8390 if Nkind (Arg1) = N_Type_Conversion then
8391 Save_Interps (Left_Opnd (N), Expression (Arg1));
8394 if Nkind (Arg2) = N_Type_Conversion then
8395 Save_Interps (Right_Opnd (N), Expression (Arg2));
8398 Set_Left_Opnd (N, Arg1);
8399 Set_Right_Opnd (N, Arg2);
8401 Set_Etype (N, Btyp);
8402 Rewrite (N, Unchecked_Convert_To (Typ, N));
8405 elsif Typ /= Etype (Left_Opnd (N))
8406 or else Typ /= Etype (Right_Opnd (N))
8408 -- Add explicit conversion where needed, and save interpretations in
8409 -- case operands are overloaded.
8411 Arg1 := Convert_To (Typ, Left_Opnd (N));
8412 Arg2 := Convert_To (Typ, Right_Opnd (N));
8414 if Nkind (Arg1) = N_Type_Conversion then
8415 Save_Interps (Left_Opnd (N), Expression (Arg1));
8417 Save_Interps (Left_Opnd (N), Arg1);
8420 if Nkind (Arg2) = N_Type_Conversion then
8421 Save_Interps (Right_Opnd (N), Expression (Arg2));
8423 Save_Interps (Right_Opnd (N), Arg2);
8426 Rewrite (Left_Opnd (N), Arg1);
8427 Rewrite (Right_Opnd (N), Arg2);
8430 Resolve_Arithmetic_Op (N, Typ);
8433 Resolve_Arithmetic_Op (N, Typ);
8435 end Resolve_Intrinsic_Operator;
8437 --------------------------------------
8438 -- Resolve_Intrinsic_Unary_Operator --
8439 --------------------------------------
8441 procedure Resolve_Intrinsic_Unary_Operator
8445 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8451 while Scope (Op) /= Standard_Standard loop
8453 pragma Assert (Present (Op));
8458 if Is_Private_Type (Typ) then
8459 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8460 Save_Interps (Right_Opnd (N), Expression (Arg2));
8462 Set_Right_Opnd (N, Arg2);
8464 Set_Etype (N, Btyp);
8465 Rewrite (N, Unchecked_Convert_To (Typ, N));
8469 Resolve_Unary_Op (N, Typ);
8471 end Resolve_Intrinsic_Unary_Operator;
8473 ------------------------
8474 -- Resolve_Logical_Op --
8475 ------------------------
8477 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8481 Check_No_Direct_Boolean_Operators (N);
8483 -- Predefined operations on scalar types yield the base type. On the
8484 -- other hand, logical operations on arrays yield the type of the
8485 -- arguments (and the context).
8487 if Is_Array_Type (Typ) then
8490 B_Typ := Base_Type (Typ);
8493 -- The following test is required because the operands of the operation
8494 -- may be literals, in which case the resulting type appears to be
8495 -- compatible with a signed integer type, when in fact it is compatible
8496 -- only with modular types. If the context itself is universal, the
8497 -- operation is illegal.
8499 if not Valid_Boolean_Arg (Typ) then
8500 Error_Msg_N ("invalid context for logical operation", N);
8501 Set_Etype (N, Any_Type);
8504 elsif Typ = Any_Modular then
8506 ("no modular type available in this context", N);
8507 Set_Etype (N, Any_Type);
8510 elsif Is_Modular_Integer_Type (Typ)
8511 and then Etype (Left_Opnd (N)) = Universal_Integer
8512 and then Etype (Right_Opnd (N)) = Universal_Integer
8514 Check_For_Visible_Operator (N, B_Typ);
8517 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8518 -- is active and the result type is standard Boolean (do not mess with
8519 -- ops that return a nonstandard Boolean type, because something strange
8522 -- Note: you might expect this replacement to be done during expansion,
8523 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8524 -- is used, no part of the right operand of an "and" or "or" operator
8525 -- should be executed if the left operand would short-circuit the
8526 -- evaluation of the corresponding "and then" or "or else". If we left
8527 -- the replacement to expansion time, then run-time checks associated
8528 -- with such operands would be evaluated unconditionally, due to being
8529 -- before the condition prior to the rewriting as short-circuit forms
8530 -- during expansion.
8532 if Short_Circuit_And_Or
8533 and then B_Typ = Standard_Boolean
8534 and then Nkind_In (N, N_Op_And, N_Op_Or)
8536 -- Mark the corresponding putative SCO operator as truly a logical
8537 -- (and short-circuit) operator.
8539 if Generate_SCO and then Comes_From_Source (N) then
8540 Set_SCO_Logical_Operator (N);
8543 if Nkind (N) = N_Op_And then
8545 Make_And_Then (Sloc (N),
8546 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8547 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8548 Analyze_And_Resolve (N, B_Typ);
8550 -- Case of OR changed to OR ELSE
8554 Make_Or_Else (Sloc (N),
8555 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8556 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8557 Analyze_And_Resolve (N, B_Typ);
8560 -- Return now, since analysis of the rewritten ops will take care of
8561 -- other reference bookkeeping and expression folding.
8566 Resolve (Left_Opnd (N), B_Typ);
8567 Resolve (Right_Opnd (N), B_Typ);
8569 Check_Unset_Reference (Left_Opnd (N));
8570 Check_Unset_Reference (Right_Opnd (N));
8572 Set_Etype (N, B_Typ);
8573 Generate_Operator_Reference (N, B_Typ);
8574 Eval_Logical_Op (N);
8576 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8577 -- only when both operands have same static lower and higher bounds. Of
8578 -- course the types have to match, so only check if operands are
8579 -- compatible and the node itself has no errors.
8581 if Is_Array_Type (B_Typ)
8582 and then Nkind (N) in N_Binary_Op
8585 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8586 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8589 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8590 -- operation if not needed.
8592 if Restriction_Check_Required (SPARK_05)
8593 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8594 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8595 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8596 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8598 Check_SPARK_05_Restriction
8599 ("array types should have matching static bounds", N);
8604 Check_Function_Writable_Actuals (N);
8605 end Resolve_Logical_Op;
8607 ---------------------------
8608 -- Resolve_Membership_Op --
8609 ---------------------------
8611 -- The context can only be a boolean type, and does not determine the
8612 -- arguments. Arguments should be unambiguous, but the preference rule for
8613 -- universal types applies.
8615 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8616 pragma Warnings (Off, Typ);
8618 L : constant Node_Id := Left_Opnd (N);
8619 R : constant Node_Id := Right_Opnd (N);
8622 procedure Resolve_Set_Membership;
8623 -- Analysis has determined a unique type for the left operand. Use it to
8624 -- resolve the disjuncts.
8626 ----------------------------
8627 -- Resolve_Set_Membership --
8628 ----------------------------
8630 procedure Resolve_Set_Membership is
8635 -- If the left operand is overloaded, find type compatible with not
8636 -- overloaded alternative of the right operand.
8638 if Is_Overloaded (L) then
8640 Alt := First (Alternatives (N));
8641 while Present (Alt) loop
8642 if not Is_Overloaded (Alt) then
8643 Ltyp := Intersect_Types (L, Alt);
8650 -- Unclear how to resolve expression if all alternatives are also
8654 Error_Msg_N ("ambiguous expression", N);
8663 Alt := First (Alternatives (N));
8664 while Present (Alt) loop
8666 -- Alternative is an expression, a range
8667 -- or a subtype mark.
8669 if not Is_Entity_Name (Alt)
8670 or else not Is_Type (Entity (Alt))
8672 Resolve (Alt, Ltyp);
8678 -- Check for duplicates for discrete case
8680 if Is_Discrete_Type (Ltyp) then
8687 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8691 -- Loop checking duplicates. This is quadratic, but giant sets
8692 -- are unlikely in this context so it's a reasonable choice.
8695 Alt := First (Alternatives (N));
8696 while Present (Alt) loop
8697 if Is_OK_Static_Expression (Alt)
8698 and then (Nkind_In (Alt, N_Integer_Literal,
8699 N_Character_Literal)
8700 or else Nkind (Alt) in N_Has_Entity)
8703 Alts (Nalts) := (Alt, Expr_Value (Alt));
8705 for J in 1 .. Nalts - 1 loop
8706 if Alts (J).Val = Alts (Nalts).Val then
8707 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8708 Error_Msg_N ("duplicate of value given#??", Alt);
8717 end Resolve_Set_Membership;
8719 -- Start of processing for Resolve_Membership_Op
8722 if L = Error or else R = Error then
8726 if Present (Alternatives (N)) then
8727 Resolve_Set_Membership;
8730 elsif not Is_Overloaded (R)
8732 (Etype (R) = Universal_Integer
8734 Etype (R) = Universal_Real)
8735 and then Is_Overloaded (L)
8739 -- Ada 2005 (AI-251): Support the following case:
8741 -- type I is interface;
8742 -- type T is tagged ...
8744 -- function Test (O : I'Class) is
8746 -- return O in T'Class.
8749 -- In this case we have nothing else to do. The membership test will be
8750 -- done at run time.
8752 elsif Ada_Version >= Ada_2005
8753 and then Is_Class_Wide_Type (Etype (L))
8754 and then Is_Interface (Etype (L))
8755 and then Is_Class_Wide_Type (Etype (R))
8756 and then not Is_Interface (Etype (R))
8760 T := Intersect_Types (L, R);
8763 -- If mixed-mode operations are present and operands are all literal,
8764 -- the only interpretation involves Duration, which is probably not
8765 -- the intention of the programmer.
8767 if T = Any_Fixed then
8768 T := Unique_Fixed_Point_Type (N);
8770 if T = Any_Type then
8776 Check_Unset_Reference (L);
8778 if Nkind (R) = N_Range
8779 and then not Is_Scalar_Type (T)
8781 Error_Msg_N ("scalar type required for range", R);
8784 if Is_Entity_Name (R) then
8785 Freeze_Expression (R);
8788 Check_Unset_Reference (R);
8791 -- Here after resolving membership operation
8795 Eval_Membership_Op (N);
8796 Check_Function_Writable_Actuals (N);
8797 end Resolve_Membership_Op;
8803 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8804 Loc : constant Source_Ptr := Sloc (N);
8807 -- Handle restriction against anonymous null access values This
8808 -- restriction can be turned off using -gnatdj.
8810 -- Ada 2005 (AI-231): Remove restriction
8812 if Ada_Version < Ada_2005
8813 and then not Debug_Flag_J
8814 and then Ekind (Typ) = E_Anonymous_Access_Type
8815 and then Comes_From_Source (N)
8817 -- In the common case of a call which uses an explicitly null value
8818 -- for an access parameter, give specialized error message.
8820 if Nkind (Parent (N)) in N_Subprogram_Call then
8822 ("null is not allowed as argument for an access parameter", N);
8824 -- Standard message for all other cases (are there any?)
8828 ("null cannot be of an anonymous access type", N);
8832 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8833 -- assignment to a null-excluding object
8835 if Ada_Version >= Ada_2005
8836 and then Can_Never_Be_Null (Typ)
8837 and then Nkind (Parent (N)) = N_Assignment_Statement
8839 if not Inside_Init_Proc then
8841 (Compile_Time_Constraint_Error (N,
8842 "(Ada 2005) null not allowed in null-excluding objects??"),
8843 Make_Raise_Constraint_Error (Loc,
8844 Reason => CE_Access_Check_Failed));
8847 Make_Raise_Constraint_Error (Loc,
8848 Reason => CE_Access_Check_Failed));
8852 -- In a distributed context, null for a remote access to subprogram may
8853 -- need to be replaced with a special record aggregate. In this case,
8854 -- return after having done the transformation.
8856 if (Ekind (Typ) = E_Record_Type
8857 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8858 and then Remote_AST_Null_Value (N, Typ)
8863 -- The null literal takes its type from the context
8868 -----------------------
8869 -- Resolve_Op_Concat --
8870 -----------------------
8872 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8874 -- We wish to avoid deep recursion, because concatenations are often
8875 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8876 -- operands nonrecursively until we find something that is not a simple
8877 -- concatenation (A in this case). We resolve that, and then walk back
8878 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8879 -- to do the rest of the work at each level. The Parent pointers allow
8880 -- us to avoid recursion, and thus avoid running out of memory. See also
8881 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8887 -- The following code is equivalent to:
8889 -- Resolve_Op_Concat_First (NN, Typ);
8890 -- Resolve_Op_Concat_Arg (N, ...);
8891 -- Resolve_Op_Concat_Rest (N, Typ);
8893 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8894 -- operand is a concatenation.
8896 -- Walk down left operands
8899 Resolve_Op_Concat_First (NN, Typ);
8900 Op1 := Left_Opnd (NN);
8901 exit when not (Nkind (Op1) = N_Op_Concat
8902 and then not Is_Array_Type (Component_Type (Typ))
8903 and then Entity (Op1) = Entity (NN));
8907 -- Now (given the above example) NN is A&B and Op1 is A
8909 -- First resolve Op1 ...
8911 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8913 -- ... then walk NN back up until we reach N (where we started), calling
8914 -- Resolve_Op_Concat_Rest along the way.
8917 Resolve_Op_Concat_Rest (NN, Typ);
8922 if Base_Type (Etype (N)) /= Standard_String then
8923 Check_SPARK_05_Restriction
8924 ("result of concatenation should have type String", N);
8926 end Resolve_Op_Concat;
8928 ---------------------------
8929 -- Resolve_Op_Concat_Arg --
8930 ---------------------------
8932 procedure Resolve_Op_Concat_Arg
8938 Btyp : constant Entity_Id := Base_Type (Typ);
8939 Ctyp : constant Entity_Id := Component_Type (Typ);
8944 or else (not Is_Overloaded (Arg)
8945 and then Etype (Arg) /= Any_Composite
8946 and then Covers (Ctyp, Etype (Arg)))
8948 Resolve (Arg, Ctyp);
8950 Resolve (Arg, Btyp);
8953 -- If both Array & Array and Array & Component are visible, there is a
8954 -- potential ambiguity that must be reported.
8956 elsif Has_Compatible_Type (Arg, Ctyp) then
8957 if Nkind (Arg) = N_Aggregate
8958 and then Is_Composite_Type (Ctyp)
8960 if Is_Private_Type (Ctyp) then
8961 Resolve (Arg, Btyp);
8963 -- If the operation is user-defined and not overloaded use its
8964 -- profile. The operation may be a renaming, in which case it has
8965 -- been rewritten, and we want the original profile.
8967 elsif not Is_Overloaded (N)
8968 and then Comes_From_Source (Entity (Original_Node (N)))
8969 and then Ekind (Entity (Original_Node (N))) = E_Function
8973 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
8976 -- Otherwise an aggregate may match both the array type and the
8980 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
8981 Set_Etype (Arg, Any_Type);
8985 if Is_Overloaded (Arg)
8986 and then Has_Compatible_Type (Arg, Typ)
8987 and then Etype (Arg) /= Any_Type
8995 Get_First_Interp (Arg, I, It);
8997 Get_Next_Interp (I, It);
8999 -- Special-case the error message when the overloading is
9000 -- caused by a function that yields an array and can be
9001 -- called without parameters.
9003 if It.Nam = Func then
9004 Error_Msg_Sloc := Sloc (Func);
9005 Error_Msg_N ("ambiguous call to function#", Arg);
9007 ("\\interpretation as call yields&", Arg, Typ);
9009 ("\\interpretation as indexing of call yields&",
9010 Arg, Component_Type (Typ));
9013 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9015 Get_First_Interp (Arg, I, It);
9016 while Present (It.Nam) loop
9017 Error_Msg_Sloc := Sloc (It.Nam);
9019 if Base_Type (It.Typ) = Btyp
9021 Base_Type (It.Typ) = Base_Type (Ctyp)
9023 Error_Msg_N -- CODEFIX
9024 ("\\possible interpretation#", Arg);
9027 Get_Next_Interp (I, It);
9033 Resolve (Arg, Component_Type (Typ));
9035 if Nkind (Arg) = N_String_Literal then
9036 Set_Etype (Arg, Component_Type (Typ));
9039 if Arg = Left_Opnd (N) then
9040 Set_Is_Component_Left_Opnd (N);
9042 Set_Is_Component_Right_Opnd (N);
9047 Resolve (Arg, Btyp);
9050 -- Concatenation is restricted in SPARK: each operand must be either a
9051 -- string literal, the name of a string constant, a static character or
9052 -- string expression, or another concatenation. Arg cannot be a
9053 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9054 -- separately on each final operand, past concatenation operations.
9056 if Is_Character_Type (Etype (Arg)) then
9057 if not Is_OK_Static_Expression (Arg) then
9058 Check_SPARK_05_Restriction
9059 ("character operand for concatenation should be static", Arg);
9062 elsif Is_String_Type (Etype (Arg)) then
9063 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9064 and then Is_Constant_Object (Entity (Arg)))
9065 and then not Is_OK_Static_Expression (Arg)
9067 Check_SPARK_05_Restriction
9068 ("string operand for concatenation should be static", Arg);
9071 -- Do not issue error on an operand that is neither a character nor a
9072 -- string, as the error is issued in Resolve_Op_Concat.
9078 Check_Unset_Reference (Arg);
9079 end Resolve_Op_Concat_Arg;
9081 -----------------------------
9082 -- Resolve_Op_Concat_First --
9083 -----------------------------
9085 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9086 Btyp : constant Entity_Id := Base_Type (Typ);
9087 Op1 : constant Node_Id := Left_Opnd (N);
9088 Op2 : constant Node_Id := Right_Opnd (N);
9091 -- The parser folds an enormous sequence of concatenations of string
9092 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9093 -- in the right operand. If the expression resolves to a predefined "&"
9094 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9095 -- we give an error. See P_Simple_Expression in Par.Ch4.
9097 if Nkind (Op2) = N_String_Literal
9098 and then Is_Folded_In_Parser (Op2)
9099 and then Ekind (Entity (N)) = E_Function
9101 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9102 and then String_Length (Strval (Op1)) = 0);
9103 Error_Msg_N ("too many user-defined concatenations", N);
9107 Set_Etype (N, Btyp);
9109 if Is_Limited_Composite (Btyp) then
9110 Error_Msg_N ("concatenation not available for limited array", N);
9111 Explain_Limited_Type (Btyp, N);
9113 end Resolve_Op_Concat_First;
9115 ----------------------------
9116 -- Resolve_Op_Concat_Rest --
9117 ----------------------------
9119 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9120 Op1 : constant Node_Id := Left_Opnd (N);
9121 Op2 : constant Node_Id := Right_Opnd (N);
9124 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9126 Generate_Operator_Reference (N, Typ);
9128 if Is_String_Type (Typ) then
9129 Eval_Concatenation (N);
9132 -- If this is not a static concatenation, but the result is a string
9133 -- type (and not an array of strings) ensure that static string operands
9134 -- have their subtypes properly constructed.
9136 if Nkind (N) /= N_String_Literal
9137 and then Is_Character_Type (Component_Type (Typ))
9139 Set_String_Literal_Subtype (Op1, Typ);
9140 Set_String_Literal_Subtype (Op2, Typ);
9142 end Resolve_Op_Concat_Rest;
9144 ----------------------
9145 -- Resolve_Op_Expon --
9146 ----------------------
9148 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9149 B_Typ : constant Entity_Id := Base_Type (Typ);
9152 -- Catch attempts to do fixed-point exponentiation with universal
9153 -- operands, which is a case where the illegality is not caught during
9154 -- normal operator analysis. This is not done in preanalysis mode
9155 -- since the tree is not fully decorated during preanalysis.
9157 if Full_Analysis then
9158 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9159 Error_Msg_N ("exponentiation not available for fixed point", N);
9162 elsif Nkind (Parent (N)) in N_Op
9163 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9164 and then Etype (N) = Universal_Real
9165 and then Comes_From_Source (N)
9167 Error_Msg_N ("exponentiation not available for fixed point", N);
9172 if Comes_From_Source (N)
9173 and then Ekind (Entity (N)) = E_Function
9174 and then Is_Imported (Entity (N))
9175 and then Is_Intrinsic_Subprogram (Entity (N))
9177 Resolve_Intrinsic_Operator (N, Typ);
9181 if Etype (Left_Opnd (N)) = Universal_Integer
9182 or else Etype (Left_Opnd (N)) = Universal_Real
9184 Check_For_Visible_Operator (N, B_Typ);
9187 -- We do the resolution using the base type, because intermediate values
9188 -- in expressions are always of the base type, not a subtype of it.
9190 Resolve (Left_Opnd (N), B_Typ);
9191 Resolve (Right_Opnd (N), Standard_Integer);
9193 -- For integer types, right argument must be in Natural range
9195 if Is_Integer_Type (Typ) then
9196 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9199 Check_Unset_Reference (Left_Opnd (N));
9200 Check_Unset_Reference (Right_Opnd (N));
9202 Set_Etype (N, B_Typ);
9203 Generate_Operator_Reference (N, B_Typ);
9205 Analyze_Dimension (N);
9207 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9208 -- Evaluate the exponentiation operator for dimensioned type
9210 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9215 -- Set overflow checking bit. Much cleverer code needed here eventually
9216 -- and perhaps the Resolve routines should be separated for the various
9217 -- arithmetic operations, since they will need different processing. ???
9219 if Nkind (N) in N_Op then
9220 if not Overflow_Checks_Suppressed (Etype (N)) then
9221 Enable_Overflow_Check (N);
9224 end Resolve_Op_Expon;
9226 --------------------
9227 -- Resolve_Op_Not --
9228 --------------------
9230 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9233 function Parent_Is_Boolean return Boolean;
9234 -- This function determines if the parent node is a boolean operator or
9235 -- operation (comparison op, membership test, or short circuit form) and
9236 -- the not in question is the left operand of this operation. Note that
9237 -- if the not is in parens, then false is returned.
9239 -----------------------
9240 -- Parent_Is_Boolean --
9241 -----------------------
9243 function Parent_Is_Boolean return Boolean is
9245 if Paren_Count (N) /= 0 then
9249 case Nkind (Parent (N)) is
9264 return Left_Opnd (Parent (N)) = N;
9270 end Parent_Is_Boolean;
9272 -- Start of processing for Resolve_Op_Not
9275 -- Predefined operations on scalar types yield the base type. On the
9276 -- other hand, logical operations on arrays yield the type of the
9277 -- arguments (and the context).
9279 if Is_Array_Type (Typ) then
9282 B_Typ := Base_Type (Typ);
9285 -- Straightforward case of incorrect arguments
9287 if not Valid_Boolean_Arg (Typ) then
9288 Error_Msg_N ("invalid operand type for operator&", N);
9289 Set_Etype (N, Any_Type);
9292 -- Special case of probable missing parens
9294 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9295 if Parent_Is_Boolean then
9297 ("operand of not must be enclosed in parentheses",
9301 ("no modular type available in this context", N);
9304 Set_Etype (N, Any_Type);
9307 -- OK resolution of NOT
9310 -- Warn if non-boolean types involved. This is a case like not a < b
9311 -- where a and b are modular, where we will get (not a) < b and most
9312 -- likely not (a < b) was intended.
9314 if Warn_On_Questionable_Missing_Parens
9315 and then not Is_Boolean_Type (Typ)
9316 and then Parent_Is_Boolean
9318 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9321 -- Warn on double negation if checking redundant constructs
9323 if Warn_On_Redundant_Constructs
9324 and then Comes_From_Source (N)
9325 and then Comes_From_Source (Right_Opnd (N))
9326 and then Root_Type (Typ) = Standard_Boolean
9327 and then Nkind (Right_Opnd (N)) = N_Op_Not
9329 Error_Msg_N ("redundant double negation?r?", N);
9332 -- Complete resolution and evaluation of NOT
9334 Resolve (Right_Opnd (N), B_Typ);
9335 Check_Unset_Reference (Right_Opnd (N));
9336 Set_Etype (N, B_Typ);
9337 Generate_Operator_Reference (N, B_Typ);
9342 -----------------------------
9343 -- Resolve_Operator_Symbol --
9344 -----------------------------
9346 -- Nothing to be done, all resolved already
9348 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9349 pragma Warnings (Off, N);
9350 pragma Warnings (Off, Typ);
9354 end Resolve_Operator_Symbol;
9356 ----------------------------------
9357 -- Resolve_Qualified_Expression --
9358 ----------------------------------
9360 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9361 pragma Warnings (Off, Typ);
9363 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9364 Expr : constant Node_Id := Expression (N);
9367 Resolve (Expr, Target_Typ);
9369 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9370 -- operation if not needed.
9372 if Restriction_Check_Required (SPARK_05)
9373 and then Is_Array_Type (Target_Typ)
9374 and then Is_Array_Type (Etype (Expr))
9375 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9376 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9378 Check_SPARK_05_Restriction
9379 ("array types should have matching static bounds", N);
9382 -- A qualified expression requires an exact match of the type, class-
9383 -- wide matching is not allowed. However, if the qualifying type is
9384 -- specific and the expression has a class-wide type, it may still be
9385 -- okay, since it can be the result of the expansion of a call to a
9386 -- dispatching function, so we also have to check class-wideness of the
9387 -- type of the expression's original node.
9389 if (Is_Class_Wide_Type (Target_Typ)
9391 (Is_Class_Wide_Type (Etype (Expr))
9392 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9393 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9395 Wrong_Type (Expr, Target_Typ);
9398 -- If the target type is unconstrained, then we reset the type of the
9399 -- result from the type of the expression. For other cases, the actual
9400 -- subtype of the expression is the target type.
9402 if Is_Composite_Type (Target_Typ)
9403 and then not Is_Constrained (Target_Typ)
9405 Set_Etype (N, Etype (Expr));
9408 Analyze_Dimension (N);
9409 Eval_Qualified_Expression (N);
9411 -- If we still have a qualified expression after the static evaluation,
9412 -- then apply a scalar range check if needed. The reason that we do this
9413 -- after the Eval call is that otherwise, the application of the range
9414 -- check may convert an illegal static expression and result in warning
9415 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9417 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9418 Apply_Scalar_Range_Check (Expr, Typ);
9420 end Resolve_Qualified_Expression;
9422 ------------------------------
9423 -- Resolve_Raise_Expression --
9424 ------------------------------
9426 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9428 if Typ = Raise_Type then
9429 Error_Msg_N ("cannot find unique type for raise expression", N);
9430 Set_Etype (N, Any_Type);
9434 end Resolve_Raise_Expression;
9440 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9441 L : constant Node_Id := Low_Bound (N);
9442 H : constant Node_Id := High_Bound (N);
9444 function First_Last_Ref return Boolean;
9445 -- Returns True if N is of the form X'First .. X'Last where X is the
9446 -- same entity for both attributes.
9448 --------------------
9449 -- First_Last_Ref --
9450 --------------------
9452 function First_Last_Ref return Boolean is
9453 Lorig : constant Node_Id := Original_Node (L);
9454 Horig : constant Node_Id := Original_Node (H);
9457 if Nkind (Lorig) = N_Attribute_Reference
9458 and then Nkind (Horig) = N_Attribute_Reference
9459 and then Attribute_Name (Lorig) = Name_First
9460 and then Attribute_Name (Horig) = Name_Last
9463 PL : constant Node_Id := Prefix (Lorig);
9464 PH : constant Node_Id := Prefix (Horig);
9466 if Is_Entity_Name (PL)
9467 and then Is_Entity_Name (PH)
9468 and then Entity (PL) = Entity (PH)
9478 -- Start of processing for Resolve_Range
9485 -- Check for inappropriate range on unordered enumeration type
9487 if Bad_Unordered_Enumeration_Reference (N, Typ)
9489 -- Exclude X'First .. X'Last if X is the same entity for both
9491 and then not First_Last_Ref
9493 Error_Msg_Sloc := Sloc (Typ);
9495 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9498 Check_Unset_Reference (L);
9499 Check_Unset_Reference (H);
9501 -- We have to check the bounds for being within the base range as
9502 -- required for a non-static context. Normally this is automatic and
9503 -- done as part of evaluating expressions, but the N_Range node is an
9504 -- exception, since in GNAT we consider this node to be a subexpression,
9505 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9506 -- this, but that would put the test on the main evaluation path for
9509 Check_Non_Static_Context (L);
9510 Check_Non_Static_Context (H);
9512 -- Check for an ambiguous range over character literals. This will
9513 -- happen with a membership test involving only literals.
9515 if Typ = Any_Character then
9516 Ambiguous_Character (L);
9517 Set_Etype (N, Any_Type);
9521 -- If bounds are static, constant-fold them, so size computations are
9522 -- identical between front-end and back-end. Do not perform this
9523 -- transformation while analyzing generic units, as type information
9524 -- would be lost when reanalyzing the constant node in the instance.
9526 if Is_Discrete_Type (Typ) and then Expander_Active then
9527 if Is_OK_Static_Expression (L) then
9528 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9531 if Is_OK_Static_Expression (H) then
9532 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9537 --------------------------
9538 -- Resolve_Real_Literal --
9539 --------------------------
9541 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9542 Actual_Typ : constant Entity_Id := Etype (N);
9545 -- Special processing for fixed-point literals to make sure that the
9546 -- value is an exact multiple of small where this is required. We skip
9547 -- this for the universal real case, and also for generic types.
9549 if Is_Fixed_Point_Type (Typ)
9550 and then Typ /= Universal_Fixed
9551 and then Typ /= Any_Fixed
9552 and then not Is_Generic_Type (Typ)
9555 Val : constant Ureal := Realval (N);
9556 Cintr : constant Ureal := Val / Small_Value (Typ);
9557 Cint : constant Uint := UR_Trunc (Cintr);
9558 Den : constant Uint := Norm_Den (Cintr);
9562 -- Case of literal is not an exact multiple of the Small
9566 -- For a source program literal for a decimal fixed-point type,
9567 -- this is statically illegal (RM 4.9(36)).
9569 if Is_Decimal_Fixed_Point_Type (Typ)
9570 and then Actual_Typ = Universal_Real
9571 and then Comes_From_Source (N)
9573 Error_Msg_N ("value has extraneous low order digits", N);
9576 -- Generate a warning if literal from source
9578 if Is_OK_Static_Expression (N)
9579 and then Warn_On_Bad_Fixed_Value
9582 ("?b?static fixed-point value is not a multiple of Small!",
9586 -- Replace literal by a value that is the exact representation
9587 -- of a value of the type, i.e. a multiple of the small value,
9588 -- by truncation, since Machine_Rounds is false for all GNAT
9589 -- fixed-point types (RM 4.9(38)).
9591 Stat := Is_OK_Static_Expression (N);
9593 Make_Real_Literal (Sloc (N),
9594 Realval => Small_Value (Typ) * Cint));
9596 Set_Is_Static_Expression (N, Stat);
9599 -- In all cases, set the corresponding integer field
9601 Set_Corresponding_Integer_Value (N, Cint);
9605 -- Now replace the actual type by the expected type as usual
9608 Eval_Real_Literal (N);
9609 end Resolve_Real_Literal;
9611 -----------------------
9612 -- Resolve_Reference --
9613 -----------------------
9615 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9616 P : constant Node_Id := Prefix (N);
9619 -- Replace general access with specific type
9621 if Ekind (Etype (N)) = E_Allocator_Type then
9622 Set_Etype (N, Base_Type (Typ));
9625 Resolve (P, Designated_Type (Etype (N)));
9627 -- If we are taking the reference of a volatile entity, then treat it as
9628 -- a potential modification of this entity. This is too conservative,
9629 -- but necessary because remove side effects can cause transformations
9630 -- of normal assignments into reference sequences that otherwise fail to
9631 -- notice the modification.
9633 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9634 Note_Possible_Modification (P, Sure => False);
9636 end Resolve_Reference;
9638 --------------------------------
9639 -- Resolve_Selected_Component --
9640 --------------------------------
9642 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9644 Comp1 : Entity_Id := Empty; -- prevent junk warning
9645 P : constant Node_Id := Prefix (N);
9646 S : constant Node_Id := Selector_Name (N);
9647 T : Entity_Id := Etype (P);
9649 I1 : Interp_Index := 0; -- prevent junk warning
9654 function Init_Component return Boolean;
9655 -- Check whether this is the initialization of a component within an
9656 -- init proc (by assignment or call to another init proc). If true,
9657 -- there is no need for a discriminant check.
9659 --------------------
9660 -- Init_Component --
9661 --------------------
9663 function Init_Component return Boolean is
9665 return Inside_Init_Proc
9666 and then Nkind (Prefix (N)) = N_Identifier
9667 and then Chars (Prefix (N)) = Name_uInit
9668 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9671 -- Start of processing for Resolve_Selected_Component
9674 if Is_Overloaded (P) then
9676 -- Use the context type to select the prefix that has a selector
9677 -- of the correct name and type.
9680 Get_First_Interp (P, I, It);
9682 Search : while Present (It.Typ) loop
9683 if Is_Access_Type (It.Typ) then
9684 T := Designated_Type (It.Typ);
9689 -- Locate selected component. For a private prefix the selector
9690 -- can denote a discriminant.
9692 if Is_Record_Type (T) or else Is_Private_Type (T) then
9694 -- The visible components of a class-wide type are those of
9697 if Is_Class_Wide_Type (T) then
9701 Comp := First_Entity (T);
9702 while Present (Comp) loop
9703 if Chars (Comp) = Chars (S)
9704 and then Covers (Typ, Etype (Comp))
9713 It := Disambiguate (P, I1, I, Any_Type);
9715 if It = No_Interp then
9717 ("ambiguous prefix for selected component", N);
9724 -- There may be an implicit dereference. Retrieve
9725 -- designated record type.
9727 if Is_Access_Type (It1.Typ) then
9728 T := Designated_Type (It1.Typ);
9733 if Scope (Comp1) /= T then
9735 -- Resolution chooses the new interpretation.
9736 -- Find the component with the right name.
9738 Comp1 := First_Entity (T);
9739 while Present (Comp1)
9740 and then Chars (Comp1) /= Chars (S)
9742 Comp1 := Next_Entity (Comp1);
9751 Comp := Next_Entity (Comp);
9755 Get_Next_Interp (I, It);
9758 -- There must be a legal interpretation at this point
9760 pragma Assert (Found);
9761 Resolve (P, It1.Typ);
9763 Set_Entity_With_Checks (S, Comp1);
9766 -- Resolve prefix with its type
9771 -- Generate cross-reference. We needed to wait until full overloading
9772 -- resolution was complete to do this, since otherwise we can't tell if
9773 -- we are an lvalue or not.
9775 if May_Be_Lvalue (N) then
9776 Generate_Reference (Entity (S), S, 'm');
9778 Generate_Reference (Entity (S), S, 'r');
9781 -- If prefix is an access type, the node will be transformed into an
9782 -- explicit dereference during expansion. The type of the node is the
9783 -- designated type of that of the prefix.
9785 if Is_Access_Type (Etype (P)) then
9786 T := Designated_Type (Etype (P));
9787 Check_Fully_Declared_Prefix (T, P);
9792 -- Set flag for expander if discriminant check required
9794 if Has_Discriminants (T)
9795 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
9796 and then Present (Original_Record_Component (Entity (S)))
9797 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9798 and then not Discriminant_Checks_Suppressed (T)
9799 and then not Init_Component
9801 Set_Do_Discriminant_Check (N);
9804 if Ekind (Entity (S)) = E_Void then
9805 Error_Msg_N ("premature use of component", S);
9808 -- If the prefix is a record conversion, this may be a renamed
9809 -- discriminant whose bounds differ from those of the original
9810 -- one, so we must ensure that a range check is performed.
9812 if Nkind (P) = N_Type_Conversion
9813 and then Ekind (Entity (S)) = E_Discriminant
9814 and then Is_Discrete_Type (Typ)
9816 Set_Etype (N, Base_Type (Typ));
9819 -- Note: No Eval processing is required, because the prefix is of a
9820 -- record type, or protected type, and neither can possibly be static.
9822 -- If the record type is atomic, and the component is non-atomic, then
9823 -- this is worth a warning, since we have a situation where the access
9824 -- to the component may cause extra read/writes of the atomic array
9825 -- object, or partial word accesses, both of which may be unexpected.
9827 if Nkind (N) = N_Selected_Component
9828 and then Is_Atomic_Ref_With_Address (N)
9829 and then not Is_Atomic (Entity (S))
9830 and then not Is_Atomic (Etype (Entity (S)))
9833 ("??access to non-atomic component of atomic record",
9836 ("\??may cause unexpected accesses to atomic object",
9840 Analyze_Dimension (N);
9841 end Resolve_Selected_Component;
9847 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9848 B_Typ : constant Entity_Id := Base_Type (Typ);
9849 L : constant Node_Id := Left_Opnd (N);
9850 R : constant Node_Id := Right_Opnd (N);
9853 -- We do the resolution using the base type, because intermediate values
9854 -- in expressions always are of the base type, not a subtype of it.
9857 Resolve (R, Standard_Natural);
9859 Check_Unset_Reference (L);
9860 Check_Unset_Reference (R);
9862 Set_Etype (N, B_Typ);
9863 Generate_Operator_Reference (N, B_Typ);
9867 ---------------------------
9868 -- Resolve_Short_Circuit --
9869 ---------------------------
9871 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9872 B_Typ : constant Entity_Id := Base_Type (Typ);
9873 L : constant Node_Id := Left_Opnd (N);
9874 R : constant Node_Id := Right_Opnd (N);
9877 -- Ensure all actions associated with the left operand (e.g.
9878 -- finalization of transient controlled objects) are fully evaluated
9879 -- locally within an expression with actions. This is particularly
9880 -- helpful for coverage analysis. However this should not happen in
9883 if Expander_Active then
9885 Reloc_L : constant Node_Id := Relocate_Node (L);
9887 Save_Interps (Old_N => L, New_N => Reloc_L);
9890 Make_Expression_With_Actions (Sloc (L),
9891 Actions => New_List,
9892 Expression => Reloc_L));
9894 -- Set Comes_From_Source on L to preserve warnings for unset
9897 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9904 -- Check for issuing warning for always False assert/check, this happens
9905 -- when assertions are turned off, in which case the pragma Assert/Check
9906 -- was transformed into:
9908 -- if False and then <condition> then ...
9910 -- and we detect this pattern
9912 if Warn_On_Assertion_Failure
9913 and then Is_Entity_Name (R)
9914 and then Entity (R) = Standard_False
9915 and then Nkind (Parent (N)) = N_If_Statement
9916 and then Nkind (N) = N_And_Then
9917 and then Is_Entity_Name (L)
9918 and then Entity (L) = Standard_False
9921 Orig : constant Node_Id := Original_Node (Parent (N));
9924 -- Special handling of Asssert pragma
9926 if Nkind (Orig) = N_Pragma
9927 and then Pragma_Name (Orig) = Name_Assert
9930 Expr : constant Node_Id :=
9933 (First (Pragma_Argument_Associations (Orig))));
9936 -- Don't warn if original condition is explicit False,
9937 -- since obviously the failure is expected in this case.
9939 if Is_Entity_Name (Expr)
9940 and then Entity (Expr) = Standard_False
9944 -- Issue warning. We do not want the deletion of the
9945 -- IF/AND-THEN to take this message with it. We achieve this
9946 -- by making sure that the expanded code points to the Sloc
9947 -- of the expression, not the original pragma.
9950 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
9951 -- The source location of the expression is not usually
9952 -- the best choice here. For example, it gets located on
9953 -- the last AND keyword in a chain of boolean expressiond
9954 -- AND'ed together. It is best to put the message on the
9955 -- first character of the assertion, which is the effect
9956 -- of the First_Node call here.
9959 ("?A?assertion would fail at run time!",
9961 (First (Pragma_Argument_Associations (Orig))));
9965 -- Similar processing for Check pragma
9967 elsif Nkind (Orig) = N_Pragma
9968 and then Pragma_Name (Orig) = Name_Check
9970 -- Don't want to warn if original condition is explicit False
9973 Expr : constant Node_Id :=
9976 (Next (First (Pragma_Argument_Associations (Orig)))));
9978 if Is_Entity_Name (Expr)
9979 and then Entity (Expr) = Standard_False
9986 -- Again use Error_Msg_F rather than Error_Msg_N, see
9987 -- comment above for an explanation of why we do this.
9990 ("?A?check would fail at run time!",
9992 (Last (Pragma_Argument_Associations (Orig))));
9999 -- Continue with processing of short circuit
10001 Check_Unset_Reference (L);
10002 Check_Unset_Reference (R);
10004 Set_Etype (N, B_Typ);
10005 Eval_Short_Circuit (N);
10006 end Resolve_Short_Circuit;
10008 -------------------
10009 -- Resolve_Slice --
10010 -------------------
10012 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10013 Drange : constant Node_Id := Discrete_Range (N);
10014 Name : constant Node_Id := Prefix (N);
10015 Array_Type : Entity_Id := Empty;
10016 Dexpr : Node_Id := Empty;
10017 Index_Type : Entity_Id;
10020 if Is_Overloaded (Name) then
10022 -- Use the context type to select the prefix that yields the correct
10027 I1 : Interp_Index := 0;
10029 P : constant Node_Id := Prefix (N);
10030 Found : Boolean := False;
10033 Get_First_Interp (P, I, It);
10034 while Present (It.Typ) loop
10035 if (Is_Array_Type (It.Typ)
10036 and then Covers (Typ, It.Typ))
10037 or else (Is_Access_Type (It.Typ)
10038 and then Is_Array_Type (Designated_Type (It.Typ))
10039 and then Covers (Typ, Designated_Type (It.Typ)))
10042 It := Disambiguate (P, I1, I, Any_Type);
10044 if It = No_Interp then
10045 Error_Msg_N ("ambiguous prefix for slicing", N);
10046 Set_Etype (N, Typ);
10050 Array_Type := It.Typ;
10055 Array_Type := It.Typ;
10060 Get_Next_Interp (I, It);
10065 Array_Type := Etype (Name);
10068 Resolve (Name, Array_Type);
10070 if Is_Access_Type (Array_Type) then
10071 Apply_Access_Check (N);
10072 Array_Type := Designated_Type (Array_Type);
10074 -- If the prefix is an access to an unconstrained array, we must use
10075 -- the actual subtype of the object to perform the index checks. The
10076 -- object denoted by the prefix is implicit in the node, so we build
10077 -- an explicit representation for it in order to compute the actual
10080 if not Is_Constrained (Array_Type) then
10081 Remove_Side_Effects (Prefix (N));
10084 Obj : constant Node_Id :=
10085 Make_Explicit_Dereference (Sloc (N),
10086 Prefix => New_Copy_Tree (Prefix (N)));
10088 Set_Etype (Obj, Array_Type);
10089 Set_Parent (Obj, Parent (N));
10090 Array_Type := Get_Actual_Subtype (Obj);
10094 elsif Is_Entity_Name (Name)
10095 or else Nkind (Name) = N_Explicit_Dereference
10096 or else (Nkind (Name) = N_Function_Call
10097 and then not Is_Constrained (Etype (Name)))
10099 Array_Type := Get_Actual_Subtype (Name);
10101 -- If the name is a selected component that depends on discriminants,
10102 -- build an actual subtype for it. This can happen only when the name
10103 -- itself is overloaded; otherwise the actual subtype is created when
10104 -- the selected component is analyzed.
10106 elsif Nkind (Name) = N_Selected_Component
10107 and then Full_Analysis
10108 and then Depends_On_Discriminant (First_Index (Array_Type))
10111 Act_Decl : constant Node_Id :=
10112 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10114 Insert_Action (N, Act_Decl);
10115 Array_Type := Defining_Identifier (Act_Decl);
10118 -- Maybe this should just be "else", instead of checking for the
10119 -- specific case of slice??? This is needed for the case where the
10120 -- prefix is an Image attribute, which gets expanded to a slice, and so
10121 -- has a constrained subtype which we want to use for the slice range
10122 -- check applied below (the range check won't get done if the
10123 -- unconstrained subtype of the 'Image is used).
10125 elsif Nkind (Name) = N_Slice then
10126 Array_Type := Etype (Name);
10129 -- Obtain the type of the array index
10131 if Ekind (Array_Type) = E_String_Literal_Subtype then
10132 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10134 Index_Type := Etype (First_Index (Array_Type));
10137 -- If name was overloaded, set slice type correctly now
10139 Set_Etype (N, Array_Type);
10141 -- Handle the generation of a range check that compares the array index
10142 -- against the discrete_range. The check is not applied to internally
10143 -- built nodes associated with the expansion of dispatch tables. Check
10144 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10147 if Tagged_Type_Expansion
10148 and then RTU_Loaded (Ada_Tags)
10149 and then Nkind (Prefix (N)) = N_Selected_Component
10150 and then Present (Entity (Selector_Name (Prefix (N))))
10151 and then Entity (Selector_Name (Prefix (N))) =
10152 RTE_Record_Component (RE_Prims_Ptr)
10156 -- The discrete_range is specified by a subtype indication. Create a
10157 -- shallow copy and inherit the type, parent and source location from
10158 -- the discrete_range. This ensures that the range check is inserted
10159 -- relative to the slice and that the runtime exception points to the
10160 -- proper construct.
10162 elsif Is_Entity_Name (Drange) then
10163 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10165 Set_Etype (Dexpr, Etype (Drange));
10166 Set_Parent (Dexpr, Parent (Drange));
10167 Set_Sloc (Dexpr, Sloc (Drange));
10169 -- The discrete_range is a regular range. Resolve the bounds and remove
10170 -- their side effects.
10173 Resolve (Drange, Base_Type (Index_Type));
10175 if Nkind (Drange) = N_Range then
10176 Force_Evaluation (Low_Bound (Drange));
10177 Force_Evaluation (High_Bound (Drange));
10183 if Present (Dexpr) then
10184 Apply_Range_Check (Dexpr, Index_Type);
10187 Set_Slice_Subtype (N);
10189 -- Check bad use of type with predicates
10195 if Nkind (Drange) = N_Subtype_Indication
10196 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10198 Subt := Entity (Subtype_Mark (Drange));
10200 Subt := Etype (Drange);
10203 if Has_Predicates (Subt) then
10204 Bad_Predicated_Subtype_Use
10205 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10209 -- Otherwise here is where we check suspicious indexes
10211 if Nkind (Drange) = N_Range then
10212 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10213 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10216 Analyze_Dimension (N);
10220 ----------------------------
10221 -- Resolve_String_Literal --
10222 ----------------------------
10224 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10225 C_Typ : constant Entity_Id := Component_Type (Typ);
10226 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10227 Loc : constant Source_Ptr := Sloc (N);
10228 Str : constant String_Id := Strval (N);
10229 Strlen : constant Nat := String_Length (Str);
10230 Subtype_Id : Entity_Id;
10231 Need_Check : Boolean;
10234 -- For a string appearing in a concatenation, defer creation of the
10235 -- string_literal_subtype until the end of the resolution of the
10236 -- concatenation, because the literal may be constant-folded away. This
10237 -- is a useful optimization for long concatenation expressions.
10239 -- If the string is an aggregate built for a single character (which
10240 -- happens in a non-static context) or a is null string to which special
10241 -- checks may apply, we build the subtype. Wide strings must also get a
10242 -- string subtype if they come from a one character aggregate. Strings
10243 -- generated by attributes might be static, but it is often hard to
10244 -- determine whether the enclosing context is static, so we generate
10245 -- subtypes for them as well, thus losing some rarer optimizations ???
10246 -- Same for strings that come from a static conversion.
10249 (Strlen = 0 and then Typ /= Standard_String)
10250 or else Nkind (Parent (N)) /= N_Op_Concat
10251 or else (N /= Left_Opnd (Parent (N))
10252 and then N /= Right_Opnd (Parent (N)))
10253 or else ((Typ = Standard_Wide_String
10254 or else Typ = Standard_Wide_Wide_String)
10255 and then Nkind (Original_Node (N)) /= N_String_Literal);
10257 -- If the resolving type is itself a string literal subtype, we can just
10258 -- reuse it, since there is no point in creating another.
10260 if Ekind (Typ) = E_String_Literal_Subtype then
10263 elsif Nkind (Parent (N)) = N_Op_Concat
10264 and then not Need_Check
10265 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10266 N_Attribute_Reference,
10267 N_Qualified_Expression,
10272 -- Do not generate a string literal subtype for the default expression
10273 -- of a formal parameter in GNATprove mode. This is because the string
10274 -- subtype is associated with the freezing actions of the subprogram,
10275 -- however freezing is disabled in GNATprove mode and as a result the
10276 -- subtype is unavailable.
10278 elsif GNATprove_Mode
10279 and then Nkind (Parent (N)) = N_Parameter_Specification
10283 -- Otherwise we must create a string literal subtype. Note that the
10284 -- whole idea of string literal subtypes is simply to avoid the need
10285 -- for building a full fledged array subtype for each literal.
10288 Set_String_Literal_Subtype (N, Typ);
10289 Subtype_Id := Etype (N);
10292 if Nkind (Parent (N)) /= N_Op_Concat
10295 Set_Etype (N, Subtype_Id);
10296 Eval_String_Literal (N);
10299 if Is_Limited_Composite (Typ)
10300 or else Is_Private_Composite (Typ)
10302 Error_Msg_N ("string literal not available for private array", N);
10303 Set_Etype (N, Any_Type);
10307 -- The validity of a null string has been checked in the call to
10308 -- Eval_String_Literal.
10313 -- Always accept string literal with component type Any_Character, which
10314 -- occurs in error situations and in comparisons of literals, both of
10315 -- which should accept all literals.
10317 elsif R_Typ = Any_Character then
10320 -- If the type is bit-packed, then we always transform the string
10321 -- literal into a full fledged aggregate.
10323 elsif Is_Bit_Packed_Array (Typ) then
10326 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10329 -- For Standard.Wide_Wide_String, or any other type whose component
10330 -- type is Standard.Wide_Wide_Character, we know that all the
10331 -- characters in the string must be acceptable, since the parser
10332 -- accepted the characters as valid character literals.
10334 if R_Typ = Standard_Wide_Wide_Character then
10337 -- For the case of Standard.String, or any other type whose component
10338 -- type is Standard.Character, we must make sure that there are no
10339 -- wide characters in the string, i.e. that it is entirely composed
10340 -- of characters in range of type Character.
10342 -- If the string literal is the result of a static concatenation, the
10343 -- test has already been performed on the components, and need not be
10346 elsif R_Typ = Standard_Character
10347 and then Nkind (Original_Node (N)) /= N_Op_Concat
10349 for J in 1 .. Strlen loop
10350 if not In_Character_Range (Get_String_Char (Str, J)) then
10352 -- If we are out of range, post error. This is one of the
10353 -- very few places that we place the flag in the middle of
10354 -- a token, right under the offending wide character. Not
10355 -- quite clear if this is right wrt wide character encoding
10356 -- sequences, but it's only an error message.
10359 ("literal out of range of type Standard.Character",
10360 Source_Ptr (Int (Loc) + J));
10365 -- For the case of Standard.Wide_String, or any other type whose
10366 -- component type is Standard.Wide_Character, we must make sure that
10367 -- there are no wide characters in the string, i.e. that it is
10368 -- entirely composed of characters in range of type Wide_Character.
10370 -- If the string literal is the result of a static concatenation,
10371 -- the test has already been performed on the components, and need
10372 -- not be repeated.
10374 elsif R_Typ = Standard_Wide_Character
10375 and then Nkind (Original_Node (N)) /= N_Op_Concat
10377 for J in 1 .. Strlen loop
10378 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10380 -- If we are out of range, post error. This is one of the
10381 -- very few places that we place the flag in the middle of
10382 -- a token, right under the offending wide character.
10384 -- This is not quite right, because characters in general
10385 -- will take more than one character position ???
10388 ("literal out of range of type Standard.Wide_Character",
10389 Source_Ptr (Int (Loc) + J));
10394 -- If the root type is not a standard character, then we will convert
10395 -- the string into an aggregate and will let the aggregate code do
10396 -- the checking. Standard Wide_Wide_Character is also OK here.
10402 -- See if the component type of the array corresponding to the string
10403 -- has compile time known bounds. If yes we can directly check
10404 -- whether the evaluation of the string will raise constraint error.
10405 -- Otherwise we need to transform the string literal into the
10406 -- corresponding character aggregate and let the aggregate code do
10409 if Is_Standard_Character_Type (R_Typ) then
10411 -- Check for the case of full range, where we are definitely OK
10413 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10417 -- Here the range is not the complete base type range, so check
10420 Comp_Typ_Lo : constant Node_Id :=
10421 Type_Low_Bound (Component_Type (Typ));
10422 Comp_Typ_Hi : constant Node_Id :=
10423 Type_High_Bound (Component_Type (Typ));
10428 if Compile_Time_Known_Value (Comp_Typ_Lo)
10429 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10431 for J in 1 .. Strlen loop
10432 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10434 if Char_Val < Expr_Value (Comp_Typ_Lo)
10435 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10437 Apply_Compile_Time_Constraint_Error
10438 (N, "character out of range??",
10439 CE_Range_Check_Failed,
10440 Loc => Source_Ptr (Int (Loc) + J));
10450 -- If we got here we meed to transform the string literal into the
10451 -- equivalent qualified positional array aggregate. This is rather
10452 -- heavy artillery for this situation, but it is hard work to avoid.
10455 Lits : constant List_Id := New_List;
10456 P : Source_Ptr := Loc + 1;
10460 -- Build the character literals, we give them source locations that
10461 -- correspond to the string positions, which is a bit tricky given
10462 -- the possible presence of wide character escape sequences.
10464 for J in 1 .. Strlen loop
10465 C := Get_String_Char (Str, J);
10466 Set_Character_Literal_Name (C);
10469 Make_Character_Literal (P,
10470 Chars => Name_Find,
10471 Char_Literal_Value => UI_From_CC (C)));
10473 if In_Character_Range (C) then
10476 -- Should we have a call to Skip_Wide here ???
10485 Make_Qualified_Expression (Loc,
10486 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10488 Make_Aggregate (Loc, Expressions => Lits)));
10490 Analyze_And_Resolve (N, Typ);
10492 end Resolve_String_Literal;
10494 -----------------------------
10495 -- Resolve_Type_Conversion --
10496 -----------------------------
10498 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10499 Conv_OK : constant Boolean := Conversion_OK (N);
10500 Operand : constant Node_Id := Expression (N);
10501 Operand_Typ : constant Entity_Id := Etype (Operand);
10502 Target_Typ : constant Entity_Id := Etype (N);
10507 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10508 -- Set to False to suppress cases where we want to suppress the test
10509 -- for redundancy to avoid possible false positives on this warning.
10513 and then not Valid_Conversion (N, Target_Typ, Operand)
10518 -- If the Operand Etype is Universal_Fixed, then the conversion is
10519 -- never redundant. We need this check because by the time we have
10520 -- finished the rather complex transformation, the conversion looks
10521 -- redundant when it is not.
10523 if Operand_Typ = Universal_Fixed then
10524 Test_Redundant := False;
10526 -- If the operand is marked as Any_Fixed, then special processing is
10527 -- required. This is also a case where we suppress the test for a
10528 -- redundant conversion, since most certainly it is not redundant.
10530 elsif Operand_Typ = Any_Fixed then
10531 Test_Redundant := False;
10533 -- Mixed-mode operation involving a literal. Context must be a fixed
10534 -- type which is applied to the literal subsequently.
10536 if Is_Fixed_Point_Type (Typ) then
10537 Set_Etype (Operand, Universal_Real);
10539 elsif Is_Numeric_Type (Typ)
10540 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10541 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10543 Etype (Left_Opnd (Operand)) = Universal_Real)
10545 -- Return if expression is ambiguous
10547 if Unique_Fixed_Point_Type (N) = Any_Type then
10550 -- If nothing else, the available fixed type is Duration
10553 Set_Etype (Operand, Standard_Duration);
10556 -- Resolve the real operand with largest available precision
10558 if Etype (Right_Opnd (Operand)) = Universal_Real then
10559 Rop := New_Copy_Tree (Right_Opnd (Operand));
10561 Rop := New_Copy_Tree (Left_Opnd (Operand));
10564 Resolve (Rop, Universal_Real);
10566 -- If the operand is a literal (it could be a non-static and
10567 -- illegal exponentiation) check whether the use of Duration
10568 -- is potentially inaccurate.
10570 if Nkind (Rop) = N_Real_Literal
10571 and then Realval (Rop) /= Ureal_0
10572 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10575 ("??universal real operand can only "
10576 & "be interpreted as Duration!", Rop);
10578 ("\??precision will be lost in the conversion!", Rop);
10581 elsif Is_Numeric_Type (Typ)
10582 and then Nkind (Operand) in N_Op
10583 and then Unique_Fixed_Point_Type (N) /= Any_Type
10585 Set_Etype (Operand, Standard_Duration);
10588 Error_Msg_N ("invalid context for mixed mode operation", N);
10589 Set_Etype (Operand, Any_Type);
10596 -- In SPARK, a type conversion between array types should be restricted
10597 -- to types which have matching static bounds.
10599 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10600 -- operation if not needed.
10602 if Restriction_Check_Required (SPARK_05)
10603 and then Is_Array_Type (Target_Typ)
10604 and then Is_Array_Type (Operand_Typ)
10605 and then Operand_Typ /= Any_Composite -- or else Operand in error
10606 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10608 Check_SPARK_05_Restriction
10609 ("array types should have matching static bounds", N);
10612 -- In formal mode, the operand of an ancestor type conversion must be an
10613 -- object (not an expression).
10615 if Is_Tagged_Type (Target_Typ)
10616 and then not Is_Class_Wide_Type (Target_Typ)
10617 and then Is_Tagged_Type (Operand_Typ)
10618 and then not Is_Class_Wide_Type (Operand_Typ)
10619 and then Is_Ancestor (Target_Typ, Operand_Typ)
10620 and then not Is_SPARK_05_Object_Reference (Operand)
10622 Check_SPARK_05_Restriction ("object required", Operand);
10625 Analyze_Dimension (N);
10627 -- Note: we do the Eval_Type_Conversion call before applying the
10628 -- required checks for a subtype conversion. This is important, since
10629 -- both are prepared under certain circumstances to change the type
10630 -- conversion to a constraint error node, but in the case of
10631 -- Eval_Type_Conversion this may reflect an illegality in the static
10632 -- case, and we would miss the illegality (getting only a warning
10633 -- message), if we applied the type conversion checks first.
10635 Eval_Type_Conversion (N);
10637 -- Even when evaluation is not possible, we may be able to simplify the
10638 -- conversion or its expression. This needs to be done before applying
10639 -- checks, since otherwise the checks may use the original expression
10640 -- and defeat the simplifications. This is specifically the case for
10641 -- elimination of the floating-point Truncation attribute in
10642 -- float-to-int conversions.
10644 Simplify_Type_Conversion (N);
10646 -- If after evaluation we still have a type conversion, then we may need
10647 -- to apply checks required for a subtype conversion.
10649 -- Skip these type conversion checks if universal fixed operands
10650 -- operands involved, since range checks are handled separately for
10651 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10653 if Nkind (N) = N_Type_Conversion
10654 and then not Is_Generic_Type (Root_Type (Target_Typ))
10655 and then Target_Typ /= Universal_Fixed
10656 and then Operand_Typ /= Universal_Fixed
10658 Apply_Type_Conversion_Checks (N);
10661 -- Issue warning for conversion of simple object to its own type. We
10662 -- have to test the original nodes, since they may have been rewritten
10663 -- by various optimizations.
10665 Orig_N := Original_Node (N);
10667 -- Here we test for a redundant conversion if the warning mode is
10668 -- active (and was not locally reset), and we have a type conversion
10669 -- from source not appearing in a generic instance.
10672 and then Nkind (Orig_N) = N_Type_Conversion
10673 and then Comes_From_Source (Orig_N)
10674 and then not In_Instance
10676 Orig_N := Original_Node (Expression (Orig_N));
10677 Orig_T := Target_Typ;
10679 -- If the node is part of a larger expression, the Target_Type
10680 -- may not be the original type of the node if the context is a
10681 -- condition. Recover original type to see if conversion is needed.
10683 if Is_Boolean_Type (Orig_T)
10684 and then Nkind (Parent (N)) in N_Op
10686 Orig_T := Etype (Parent (N));
10689 -- If we have an entity name, then give the warning if the entity
10690 -- is the right type, or if it is a loop parameter covered by the
10691 -- original type (that's needed because loop parameters have an
10692 -- odd subtype coming from the bounds).
10694 if (Is_Entity_Name (Orig_N)
10696 (Etype (Entity (Orig_N)) = Orig_T
10698 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10699 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10701 -- If not an entity, then type of expression must match
10703 or else Etype (Orig_N) = Orig_T
10705 -- One more check, do not give warning if the analyzed conversion
10706 -- has an expression with non-static bounds, and the bounds of the
10707 -- target are static. This avoids junk warnings in cases where the
10708 -- conversion is necessary to establish staticness, for example in
10709 -- a case statement.
10711 if not Is_OK_Static_Subtype (Operand_Typ)
10712 and then Is_OK_Static_Subtype (Target_Typ)
10716 -- Finally, if this type conversion occurs in a context requiring
10717 -- a prefix, and the expression is a qualified expression then the
10718 -- type conversion is not redundant, since a qualified expression
10719 -- is not a prefix, whereas a type conversion is. For example, "X
10720 -- := T'(Funx(...)).Y;" is illegal because a selected component
10721 -- requires a prefix, but a type conversion makes it legal: "X :=
10722 -- T(T'(Funx(...))).Y;"
10724 -- In Ada 2012, a qualified expression is a name, so this idiom is
10725 -- no longer needed, but we still suppress the warning because it
10726 -- seems unfriendly for warnings to pop up when you switch to the
10727 -- newer language version.
10729 elsif Nkind (Orig_N) = N_Qualified_Expression
10730 and then Nkind_In (Parent (N), N_Attribute_Reference,
10731 N_Indexed_Component,
10732 N_Selected_Component,
10734 N_Explicit_Dereference)
10738 -- Never warn on conversion to Long_Long_Integer'Base since
10739 -- that is most likely an artifact of the extended overflow
10740 -- checking and comes from complex expanded code.
10742 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10745 -- Here we give the redundant conversion warning. If it is an
10746 -- entity, give the name of the entity in the message. If not,
10747 -- just mention the expression.
10749 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10752 if Is_Entity_Name (Orig_N) then
10753 Error_Msg_Node_2 := Orig_T;
10754 Error_Msg_NE -- CODEFIX
10755 ("??redundant conversion, & is of type &!",
10756 N, Entity (Orig_N));
10759 ("??redundant conversion, expression is of type&!",
10766 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10767 -- No need to perform any interface conversion if the type of the
10768 -- expression coincides with the target type.
10770 if Ada_Version >= Ada_2005
10771 and then Expander_Active
10772 and then Operand_Typ /= Target_Typ
10775 Opnd : Entity_Id := Operand_Typ;
10776 Target : Entity_Id := Target_Typ;
10779 -- If the type of the operand is a limited view, use nonlimited
10780 -- view when available. If it is a class-wide type, recover the
10781 -- class-wide type of the nonlimited view.
10783 if From_Limited_With (Opnd)
10784 and then Has_Non_Limited_View (Opnd)
10786 Opnd := Non_Limited_View (Opnd);
10787 Set_Etype (Expression (N), Opnd);
10790 if Is_Access_Type (Opnd) then
10791 Opnd := Designated_Type (Opnd);
10794 if Is_Access_Type (Target_Typ) then
10795 Target := Designated_Type (Target);
10798 if Opnd = Target then
10801 -- Conversion from interface type
10803 elsif Is_Interface (Opnd) then
10805 -- Ada 2005 (AI-217): Handle entities from limited views
10807 if From_Limited_With (Opnd) then
10808 Error_Msg_Qual_Level := 99;
10809 Error_Msg_NE -- CODEFIX
10810 ("missing WITH clause on package &", N,
10811 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10813 ("type conversions require visibility of the full view",
10816 elsif From_Limited_With (Target)
10818 (Is_Access_Type (Target_Typ)
10819 and then Present (Non_Limited_View (Etype (Target))))
10821 Error_Msg_Qual_Level := 99;
10822 Error_Msg_NE -- CODEFIX
10823 ("missing WITH clause on package &", N,
10824 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10826 ("type conversions require visibility of the full view",
10830 Expand_Interface_Conversion (N);
10833 -- Conversion to interface type
10835 elsif Is_Interface (Target) then
10839 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10840 Opnd := Etype (Opnd);
10843 if Is_Class_Wide_Type (Opnd)
10844 or else Interface_Present_In_Ancestor
10848 Expand_Interface_Conversion (N);
10850 Error_Msg_Name_1 := Chars (Etype (Target));
10851 Error_Msg_Name_2 := Chars (Opnd);
10853 ("wrong interface conversion (% is not a progenitor "
10860 -- Ada 2012: if target type has predicates, the result requires a
10861 -- predicate check. If the context is a call to another predicate
10862 -- check we must prevent infinite recursion.
10864 if Has_Predicates (Target_Typ) then
10865 if Nkind (Parent (N)) = N_Function_Call
10866 and then Present (Name (Parent (N)))
10867 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10869 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10874 Apply_Predicate_Check (N, Target_Typ);
10878 -- If at this stage we have a real to integer conversion, make sure
10879 -- that the Do_Range_Check flag is set, because such conversions in
10880 -- general need a range check. We only need this if expansion is off
10881 -- or we are in GNATProve mode.
10883 if Nkind (N) = N_Type_Conversion
10884 and then (GNATprove_Mode or not Expander_Active)
10885 and then Is_Integer_Type (Target_Typ)
10886 and then Is_Real_Type (Operand_Typ)
10888 Set_Do_Range_Check (Operand);
10890 end Resolve_Type_Conversion;
10892 ----------------------
10893 -- Resolve_Unary_Op --
10894 ----------------------
10896 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
10897 B_Typ : constant Entity_Id := Base_Type (Typ);
10898 R : constant Node_Id := Right_Opnd (N);
10904 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
10905 Error_Msg_Name_1 := Chars (Typ);
10906 Check_SPARK_05_Restriction
10907 ("unary operator not defined for modular type%", N);
10910 -- Deal with intrinsic unary operators
10912 if Comes_From_Source (N)
10913 and then Ekind (Entity (N)) = E_Function
10914 and then Is_Imported (Entity (N))
10915 and then Is_Intrinsic_Subprogram (Entity (N))
10917 Resolve_Intrinsic_Unary_Operator (N, Typ);
10921 -- Deal with universal cases
10923 if Etype (R) = Universal_Integer
10925 Etype (R) = Universal_Real
10927 Check_For_Visible_Operator (N, B_Typ);
10930 Set_Etype (N, B_Typ);
10931 Resolve (R, B_Typ);
10933 -- Generate warning for expressions like abs (x mod 2)
10935 if Warn_On_Redundant_Constructs
10936 and then Nkind (N) = N_Op_Abs
10938 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
10940 if OK and then Hi >= Lo and then Lo >= 0 then
10941 Error_Msg_N -- CODEFIX
10942 ("?r?abs applied to known non-negative value has no effect", N);
10946 -- Deal with reference generation
10948 Check_Unset_Reference (R);
10949 Generate_Operator_Reference (N, B_Typ);
10950 Analyze_Dimension (N);
10953 -- Set overflow checking bit. Much cleverer code needed here eventually
10954 -- and perhaps the Resolve routines should be separated for the various
10955 -- arithmetic operations, since they will need different processing ???
10957 if Nkind (N) in N_Op then
10958 if not Overflow_Checks_Suppressed (Etype (N)) then
10959 Enable_Overflow_Check (N);
10963 -- Generate warning for expressions like -5 mod 3 for integers. No need
10964 -- to worry in the floating-point case, since parens do not affect the
10965 -- result so there is no point in giving in a warning.
10968 Norig : constant Node_Id := Original_Node (N);
10977 if Warn_On_Questionable_Missing_Parens
10978 and then Comes_From_Source (Norig)
10979 and then Is_Integer_Type (Typ)
10980 and then Nkind (Norig) = N_Op_Minus
10982 Rorig := Original_Node (Right_Opnd (Norig));
10984 -- We are looking for cases where the right operand is not
10985 -- parenthesized, and is a binary operator, multiply, divide, or
10986 -- mod. These are the cases where the grouping can affect results.
10988 if Paren_Count (Rorig) = 0
10989 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
10991 -- For mod, we always give the warning, since the value is
10992 -- affected by the parenthesization (e.g. (-5) mod 315 /=
10993 -- -(5 mod 315)). But for the other cases, the only concern is
10994 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
10995 -- overflows, but (-2) * 64 does not). So we try to give the
10996 -- message only when overflow is possible.
10998 if Nkind (Rorig) /= N_Op_Mod
10999 and then Compile_Time_Known_Value (R)
11001 Val := Expr_Value (R);
11003 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11004 HB := Expr_Value (Type_High_Bound (Typ));
11006 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11009 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11010 LB := Expr_Value (Type_Low_Bound (Typ));
11012 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11015 -- Note that the test below is deliberately excluding the
11016 -- largest negative number, since that is a potentially
11017 -- troublesome case (e.g. -2 * x, where the result is the
11018 -- largest negative integer has an overflow with 2 * x).
11020 if Val > LB and then Val <= HB then
11025 -- For the multiplication case, the only case we have to worry
11026 -- about is when (-a)*b is exactly the largest negative number
11027 -- so that -(a*b) can cause overflow. This can only happen if
11028 -- a is a power of 2, and more generally if any operand is a
11029 -- constant that is not a power of 2, then the parentheses
11030 -- cannot affect whether overflow occurs. We only bother to
11031 -- test the left most operand
11033 -- Loop looking at left operands for one that has known value
11036 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11037 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11038 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11040 -- Operand value of 0 or 1 skips warning
11045 -- Otherwise check power of 2, if power of 2, warn, if
11046 -- anything else, skip warning.
11049 while Lval /= 2 loop
11050 if Lval mod 2 = 1 then
11061 -- Keep looking at left operands
11063 Opnd := Left_Opnd (Opnd);
11064 end loop Opnd_Loop;
11066 -- For rem or "/" we can only have a problematic situation
11067 -- if the divisor has a value of minus one or one. Otherwise
11068 -- overflow is impossible (divisor > 1) or we have a case of
11069 -- division by zero in any case.
11071 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11072 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11073 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11078 -- If we fall through warning should be issued
11080 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11083 ("??unary minus expression should be parenthesized here!", N);
11087 end Resolve_Unary_Op;
11089 ----------------------------------
11090 -- Resolve_Unchecked_Expression --
11091 ----------------------------------
11093 procedure Resolve_Unchecked_Expression
11098 Resolve (Expression (N), Typ, Suppress => All_Checks);
11099 Set_Etype (N, Typ);
11100 end Resolve_Unchecked_Expression;
11102 ---------------------------------------
11103 -- Resolve_Unchecked_Type_Conversion --
11104 ---------------------------------------
11106 procedure Resolve_Unchecked_Type_Conversion
11110 pragma Warnings (Off, Typ);
11112 Operand : constant Node_Id := Expression (N);
11113 Opnd_Type : constant Entity_Id := Etype (Operand);
11116 -- Resolve operand using its own type
11118 Resolve (Operand, Opnd_Type);
11120 -- In an inlined context, the unchecked conversion may be applied
11121 -- to a literal, in which case its type is the type of the context.
11122 -- (In other contexts conversions cannot apply to literals).
11125 and then (Opnd_Type = Any_Character or else
11126 Opnd_Type = Any_Integer or else
11127 Opnd_Type = Any_Real)
11129 Set_Etype (Operand, Typ);
11132 Analyze_Dimension (N);
11133 Eval_Unchecked_Conversion (N);
11134 end Resolve_Unchecked_Type_Conversion;
11136 ------------------------------
11137 -- Rewrite_Operator_As_Call --
11138 ------------------------------
11140 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11141 Loc : constant Source_Ptr := Sloc (N);
11142 Actuals : constant List_Id := New_List;
11146 if Nkind (N) in N_Binary_Op then
11147 Append (Left_Opnd (N), Actuals);
11150 Append (Right_Opnd (N), Actuals);
11153 Make_Function_Call (Sloc => Loc,
11154 Name => New_Occurrence_Of (Nam, Loc),
11155 Parameter_Associations => Actuals);
11157 Preserve_Comes_From_Source (New_N, N);
11158 Preserve_Comes_From_Source (Name (New_N), N);
11159 Rewrite (N, New_N);
11160 Set_Etype (N, Etype (Nam));
11161 end Rewrite_Operator_As_Call;
11163 ------------------------------
11164 -- Rewrite_Renamed_Operator --
11165 ------------------------------
11167 procedure Rewrite_Renamed_Operator
11172 Nam : constant Name_Id := Chars (Op);
11173 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11177 -- Do not perform this transformation within a pre/postcondition,
11178 -- because the expression will be re-analyzed, and the transformation
11179 -- might affect the visibility of the operator, e.g. in an instance.
11181 if In_Assertion_Expr > 0 then
11185 -- Rewrite the operator node using the real operator, not its renaming.
11186 -- Exclude user-defined intrinsic operations of the same name, which are
11187 -- treated separately and rewritten as calls.
11189 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11190 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11191 Set_Chars (Op_Node, Nam);
11192 Set_Etype (Op_Node, Etype (N));
11193 Set_Entity (Op_Node, Op);
11194 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11196 -- Indicate that both the original entity and its renaming are
11197 -- referenced at this point.
11199 Generate_Reference (Entity (N), N);
11200 Generate_Reference (Op, N);
11203 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11206 Rewrite (N, Op_Node);
11208 -- If the context type is private, add the appropriate conversions so
11209 -- that the operator is applied to the full view. This is done in the
11210 -- routines that resolve intrinsic operators.
11212 if Is_Intrinsic_Subprogram (Op)
11213 and then Is_Private_Type (Typ)
11216 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11217 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11218 Resolve_Intrinsic_Operator (N, Typ);
11220 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11221 Resolve_Intrinsic_Unary_Operator (N, Typ);
11228 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11230 -- Operator renames a user-defined operator of the same name. Use the
11231 -- original operator in the node, which is the one Gigi knows about.
11233 Set_Entity (N, Op);
11234 Set_Is_Overloaded (N, False);
11236 end Rewrite_Renamed_Operator;
11238 -----------------------
11239 -- Set_Slice_Subtype --
11240 -----------------------
11242 -- Build an implicit subtype declaration to represent the type delivered by
11243 -- the slice. This is an abbreviated version of an array subtype. We define
11244 -- an index subtype for the slice, using either the subtype name or the
11245 -- discrete range of the slice. To be consistent with index usage elsewhere
11246 -- we create a list header to hold the single index. This list is not
11247 -- otherwise attached to the syntax tree.
11249 procedure Set_Slice_Subtype (N : Node_Id) is
11250 Loc : constant Source_Ptr := Sloc (N);
11251 Index_List : constant List_Id := New_List;
11253 Index_Subtype : Entity_Id;
11254 Index_Type : Entity_Id;
11255 Slice_Subtype : Entity_Id;
11256 Drange : constant Node_Id := Discrete_Range (N);
11259 Index_Type := Base_Type (Etype (Drange));
11261 if Is_Entity_Name (Drange) then
11262 Index_Subtype := Entity (Drange);
11265 -- We force the evaluation of a range. This is definitely needed in
11266 -- the renamed case, and seems safer to do unconditionally. Note in
11267 -- any case that since we will create and insert an Itype referring
11268 -- to this range, we must make sure any side effect removal actions
11269 -- are inserted before the Itype definition.
11271 if Nkind (Drange) = N_Range then
11272 Force_Evaluation (Low_Bound (Drange));
11273 Force_Evaluation (High_Bound (Drange));
11275 -- If the discrete range is given by a subtype indication, the
11276 -- type of the slice is the base of the subtype mark.
11278 elsif Nkind (Drange) = N_Subtype_Indication then
11280 R : constant Node_Id := Range_Expression (Constraint (Drange));
11282 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11283 Force_Evaluation (Low_Bound (R));
11284 Force_Evaluation (High_Bound (R));
11288 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11290 -- Take a new copy of Drange (where bounds have been rewritten to
11291 -- reference side-effect-free names). Using a separate tree ensures
11292 -- that further expansion (e.g. while rewriting a slice assignment
11293 -- into a FOR loop) does not attempt to remove side effects on the
11294 -- bounds again (which would cause the bounds in the index subtype
11295 -- definition to refer to temporaries before they are defined) (the
11296 -- reason is that some names are considered side effect free here
11297 -- for the subtype, but not in the context of a loop iteration
11300 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11301 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11302 Set_Etype (Index_Subtype, Index_Type);
11303 Set_Size_Info (Index_Subtype, Index_Type);
11304 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11307 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11309 Index := New_Occurrence_Of (Index_Subtype, Loc);
11310 Set_Etype (Index, Index_Subtype);
11311 Append (Index, Index_List);
11313 Set_First_Index (Slice_Subtype, Index);
11314 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11315 Set_Is_Constrained (Slice_Subtype, True);
11317 Check_Compile_Time_Size (Slice_Subtype);
11319 -- The Etype of the existing Slice node is reset to this slice subtype.
11320 -- Its bounds are obtained from its first index.
11322 Set_Etype (N, Slice_Subtype);
11324 -- For packed slice subtypes, freeze immediately (except in the case of
11325 -- being in a "spec expression" where we never freeze when we first see
11326 -- the expression).
11328 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11329 Freeze_Itype (Slice_Subtype, N);
11331 -- For all other cases insert an itype reference in the slice's actions
11332 -- so that the itype is frozen at the proper place in the tree (i.e. at
11333 -- the point where actions for the slice are analyzed). Note that this
11334 -- is different from freezing the itype immediately, which might be
11335 -- premature (e.g. if the slice is within a transient scope). This needs
11336 -- to be done only if expansion is enabled.
11338 elsif Expander_Active then
11339 Ensure_Defined (Typ => Slice_Subtype, N => N);
11341 end Set_Slice_Subtype;
11343 --------------------------------
11344 -- Set_String_Literal_Subtype --
11345 --------------------------------
11347 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11348 Loc : constant Source_Ptr := Sloc (N);
11349 Low_Bound : constant Node_Id :=
11350 Type_Low_Bound (Etype (First_Index (Typ)));
11351 Subtype_Id : Entity_Id;
11354 if Nkind (N) /= N_String_Literal then
11358 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11359 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11360 (String_Length (Strval (N))));
11361 Set_Etype (Subtype_Id, Base_Type (Typ));
11362 Set_Is_Constrained (Subtype_Id);
11363 Set_Etype (N, Subtype_Id);
11365 -- The low bound is set from the low bound of the corresponding index
11366 -- type. Note that we do not store the high bound in the string literal
11367 -- subtype, but it can be deduced if necessary from the length and the
11370 if Is_OK_Static_Expression (Low_Bound) then
11371 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11373 -- If the lower bound is not static we create a range for the string
11374 -- literal, using the index type and the known length of the literal.
11375 -- The index type is not necessarily Positive, so the upper bound is
11376 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11380 Index_List : constant List_Id := New_List;
11381 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11382 High_Bound : constant Node_Id :=
11383 Make_Attribute_Reference (Loc,
11384 Attribute_Name => Name_Val,
11386 New_Occurrence_Of (Index_Type, Loc),
11387 Expressions => New_List (
11390 Make_Attribute_Reference (Loc,
11391 Attribute_Name => Name_Pos,
11393 New_Occurrence_Of (Index_Type, Loc),
11395 New_List (New_Copy_Tree (Low_Bound))),
11397 Make_Integer_Literal (Loc,
11398 String_Length (Strval (N)) - 1))));
11400 Array_Subtype : Entity_Id;
11403 Index_Subtype : Entity_Id;
11406 if Is_Integer_Type (Index_Type) then
11407 Set_String_Literal_Low_Bound
11408 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11411 -- If the index type is an enumeration type, build bounds
11412 -- expression with attributes.
11414 Set_String_Literal_Low_Bound
11416 Make_Attribute_Reference (Loc,
11417 Attribute_Name => Name_First,
11419 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11420 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11423 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11425 -- Build bona fide subtype for the string, and wrap it in an
11426 -- unchecked conversion, because the backend expects the
11427 -- String_Literal_Subtype to have a static lower bound.
11430 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11431 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11432 Set_Scalar_Range (Index_Subtype, Drange);
11433 Set_Parent (Drange, N);
11434 Analyze_And_Resolve (Drange, Index_Type);
11436 -- In the context, the Index_Type may already have a constraint,
11437 -- so use common base type on string subtype. The base type may
11438 -- be used when generating attributes of the string, for example
11439 -- in the context of a slice assignment.
11441 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11442 Set_Size_Info (Index_Subtype, Index_Type);
11443 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11445 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11447 Index := New_Occurrence_Of (Index_Subtype, Loc);
11448 Set_Etype (Index, Index_Subtype);
11449 Append (Index, Index_List);
11451 Set_First_Index (Array_Subtype, Index);
11452 Set_Etype (Array_Subtype, Base_Type (Typ));
11453 Set_Is_Constrained (Array_Subtype, True);
11456 Make_Unchecked_Type_Conversion (Loc,
11457 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11458 Expression => Relocate_Node (N)));
11459 Set_Etype (N, Array_Subtype);
11462 end Set_String_Literal_Subtype;
11464 ------------------------------
11465 -- Simplify_Type_Conversion --
11466 ------------------------------
11468 procedure Simplify_Type_Conversion (N : Node_Id) is
11470 if Nkind (N) = N_Type_Conversion then
11472 Operand : constant Node_Id := Expression (N);
11473 Target_Typ : constant Entity_Id := Etype (N);
11474 Opnd_Typ : constant Entity_Id := Etype (Operand);
11477 -- Special processing if the conversion is the expression of a
11478 -- Rounding or Truncation attribute reference. In this case we
11481 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11487 -- with the Float_Truncate flag set to False or True respectively,
11488 -- which is more efficient.
11490 if Is_Floating_Point_Type (Opnd_Typ)
11492 (Is_Integer_Type (Target_Typ)
11493 or else (Is_Fixed_Point_Type (Target_Typ)
11494 and then Conversion_OK (N)))
11495 and then Nkind (Operand) = N_Attribute_Reference
11496 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11500 Truncate : constant Boolean :=
11501 Attribute_Name (Operand) = Name_Truncation;
11504 Relocate_Node (First (Expressions (Operand))));
11505 Set_Float_Truncate (N, Truncate);
11510 end Simplify_Type_Conversion;
11512 -----------------------------
11513 -- Unique_Fixed_Point_Type --
11514 -----------------------------
11516 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11517 T1 : Entity_Id := Empty;
11522 procedure Fixed_Point_Error;
11523 -- Give error messages for true ambiguity. Messages are posted on node
11524 -- N, and entities T1, T2 are the possible interpretations.
11526 -----------------------
11527 -- Fixed_Point_Error --
11528 -----------------------
11530 procedure Fixed_Point_Error is
11532 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11533 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11534 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11535 end Fixed_Point_Error;
11537 -- Start of processing for Unique_Fixed_Point_Type
11540 -- The operations on Duration are visible, so Duration is always a
11541 -- possible interpretation.
11543 T1 := Standard_Duration;
11545 -- Look for fixed-point types in enclosing scopes
11547 Scop := Current_Scope;
11548 while Scop /= Standard_Standard loop
11549 T2 := First_Entity (Scop);
11550 while Present (T2) loop
11551 if Is_Fixed_Point_Type (T2)
11552 and then Current_Entity (T2) = T2
11553 and then Scope (Base_Type (T2)) = Scop
11555 if Present (T1) then
11566 Scop := Scope (Scop);
11569 -- Look for visible fixed type declarations in the context
11571 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11572 while Present (Item) loop
11573 if Nkind (Item) = N_With_Clause then
11574 Scop := Entity (Name (Item));
11575 T2 := First_Entity (Scop);
11576 while Present (T2) loop
11577 if Is_Fixed_Point_Type (T2)
11578 and then Scope (Base_Type (T2)) = Scop
11579 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11581 if Present (T1) then
11596 if Nkind (N) = N_Real_Literal then
11598 ("??real literal interpreted as }!", N, T1);
11601 ("??universal_fixed expression interpreted as }!", N, T1);
11605 end Unique_Fixed_Point_Type;
11607 ----------------------
11608 -- Valid_Conversion --
11609 ----------------------
11611 function Valid_Conversion
11613 Target : Entity_Id;
11615 Report_Errs : Boolean := True) return Boolean
11617 Target_Type : constant Entity_Id := Base_Type (Target);
11618 Opnd_Type : Entity_Id := Etype (Operand);
11619 Inc_Ancestor : Entity_Id;
11621 function Conversion_Check
11623 Msg : String) return Boolean;
11624 -- Little routine to post Msg if Valid is False, returns Valid value
11626 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11627 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11629 procedure Conversion_Error_NE
11631 N : Node_Or_Entity_Id;
11632 E : Node_Or_Entity_Id);
11633 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11635 function Valid_Tagged_Conversion
11636 (Target_Type : Entity_Id;
11637 Opnd_Type : Entity_Id) return Boolean;
11638 -- Specifically test for validity of tagged conversions
11640 function Valid_Array_Conversion return Boolean;
11641 -- Check index and component conformance, and accessibility levels if
11642 -- the component types are anonymous access types (Ada 2005).
11644 ----------------------
11645 -- Conversion_Check --
11646 ----------------------
11648 function Conversion_Check
11650 Msg : String) return Boolean
11655 -- A generic unit has already been analyzed and we have verified
11656 -- that a particular conversion is OK in that context. Since the
11657 -- instance is reanalyzed without relying on the relationships
11658 -- established during the analysis of the generic, it is possible
11659 -- to end up with inconsistent views of private types. Do not emit
11660 -- the error message in such cases. The rest of the machinery in
11661 -- Valid_Conversion still ensures the proper compatibility of
11662 -- target and operand types.
11664 and then not In_Instance
11666 Conversion_Error_N (Msg, Operand);
11670 end Conversion_Check;
11672 ------------------------
11673 -- Conversion_Error_N --
11674 ------------------------
11676 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11678 if Report_Errs then
11679 Error_Msg_N (Msg, N);
11681 end Conversion_Error_N;
11683 -------------------------
11684 -- Conversion_Error_NE --
11685 -------------------------
11687 procedure Conversion_Error_NE
11689 N : Node_Or_Entity_Id;
11690 E : Node_Or_Entity_Id)
11693 if Report_Errs then
11694 Error_Msg_NE (Msg, N, E);
11696 end Conversion_Error_NE;
11698 ----------------------------
11699 -- Valid_Array_Conversion --
11700 ----------------------------
11702 function Valid_Array_Conversion return Boolean
11704 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11705 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11707 Opnd_Index : Node_Id;
11708 Opnd_Index_Type : Entity_Id;
11710 Target_Comp_Type : constant Entity_Id :=
11711 Component_Type (Target_Type);
11712 Target_Comp_Base : constant Entity_Id :=
11713 Base_Type (Target_Comp_Type);
11715 Target_Index : Node_Id;
11716 Target_Index_Type : Entity_Id;
11719 -- Error if wrong number of dimensions
11722 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11725 ("incompatible number of dimensions for conversion", Operand);
11728 -- Number of dimensions matches
11731 -- Loop through indexes of the two arrays
11733 Target_Index := First_Index (Target_Type);
11734 Opnd_Index := First_Index (Opnd_Type);
11735 while Present (Target_Index) and then Present (Opnd_Index) loop
11736 Target_Index_Type := Etype (Target_Index);
11737 Opnd_Index_Type := Etype (Opnd_Index);
11739 -- Error if index types are incompatible
11741 if not (Is_Integer_Type (Target_Index_Type)
11742 and then Is_Integer_Type (Opnd_Index_Type))
11743 and then (Root_Type (Target_Index_Type)
11744 /= Root_Type (Opnd_Index_Type))
11747 ("incompatible index types for array conversion",
11752 Next_Index (Target_Index);
11753 Next_Index (Opnd_Index);
11756 -- If component types have same base type, all set
11758 if Target_Comp_Base = Opnd_Comp_Base then
11761 -- Here if base types of components are not the same. The only
11762 -- time this is allowed is if we have anonymous access types.
11764 -- The conversion of arrays of anonymous access types can lead
11765 -- to dangling pointers. AI-392 formalizes the accessibility
11766 -- checks that must be applied to such conversions to prevent
11767 -- out-of-scope references.
11770 (Target_Comp_Base, E_Anonymous_Access_Type,
11771 E_Anonymous_Access_Subprogram_Type)
11772 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11774 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11776 if Type_Access_Level (Target_Type) <
11777 Deepest_Type_Access_Level (Opnd_Type)
11779 if In_Instance_Body then
11780 Error_Msg_Warn := SPARK_Mode /= On;
11782 ("source array type has deeper accessibility "
11783 & "level than target<<", Operand);
11784 Conversion_Error_N ("\Program_Error [<<", Operand);
11786 Make_Raise_Program_Error (Sloc (N),
11787 Reason => PE_Accessibility_Check_Failed));
11788 Set_Etype (N, Target_Type);
11791 -- Conversion not allowed because of accessibility levels
11795 ("source array type has deeper accessibility "
11796 & "level than target", Operand);
11804 -- All other cases where component base types do not match
11808 ("incompatible component types for array conversion",
11813 -- Check that component subtypes statically match. For numeric
11814 -- types this means that both must be either constrained or
11815 -- unconstrained. For enumeration types the bounds must match.
11816 -- All of this is checked in Subtypes_Statically_Match.
11818 if not Subtypes_Statically_Match
11819 (Target_Comp_Type, Opnd_Comp_Type)
11822 ("component subtypes must statically match", Operand);
11828 end Valid_Array_Conversion;
11830 -----------------------------
11831 -- Valid_Tagged_Conversion --
11832 -----------------------------
11834 function Valid_Tagged_Conversion
11835 (Target_Type : Entity_Id;
11836 Opnd_Type : Entity_Id) return Boolean
11839 -- Upward conversions are allowed (RM 4.6(22))
11841 if Covers (Target_Type, Opnd_Type)
11842 or else Is_Ancestor (Target_Type, Opnd_Type)
11846 -- Downward conversion are allowed if the operand is class-wide
11849 elsif Is_Class_Wide_Type (Opnd_Type)
11850 and then Covers (Opnd_Type, Target_Type)
11854 elsif Covers (Opnd_Type, Target_Type)
11855 or else Is_Ancestor (Opnd_Type, Target_Type)
11858 Conversion_Check (False,
11859 "downward conversion of tagged objects not allowed");
11861 -- Ada 2005 (AI-251): The conversion to/from interface types is
11864 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
11867 -- If the operand is a class-wide type obtained through a limited_
11868 -- with clause, and the context includes the nonlimited view, use
11869 -- it to determine whether the conversion is legal.
11871 elsif Is_Class_Wide_Type (Opnd_Type)
11872 and then From_Limited_With (Opnd_Type)
11873 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11874 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11878 elsif Is_Access_Type (Opnd_Type)
11879 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11884 Conversion_Error_NE
11885 ("invalid tagged conversion, not compatible with}",
11886 N, First_Subtype (Opnd_Type));
11889 end Valid_Tagged_Conversion;
11891 -- Start of processing for Valid_Conversion
11894 Check_Parameterless_Call (Operand);
11896 if Is_Overloaded (Operand) then
11906 -- Remove procedure calls, which syntactically cannot appear in
11907 -- this context, but which cannot be removed by type checking,
11908 -- because the context does not impose a type.
11910 -- The node may be labelled overloaded, but still contain only one
11911 -- interpretation because others were discarded earlier. If this
11912 -- is the case, retain the single interpretation if legal.
11914 Get_First_Interp (Operand, I, It);
11915 Opnd_Type := It.Typ;
11916 Get_Next_Interp (I, It);
11918 if Present (It.Typ)
11919 and then Opnd_Type /= Standard_Void_Type
11921 -- More than one candidate interpretation is available
11923 Get_First_Interp (Operand, I, It);
11924 while Present (It.Typ) loop
11925 if It.Typ = Standard_Void_Type then
11929 -- When compiling for a system where Address is of a visible
11930 -- integer type, spurious ambiguities can be produced when
11931 -- arithmetic operations have a literal operand and return
11932 -- System.Address or a descendant of it. These ambiguities
11933 -- are usually resolved by the context, but for conversions
11934 -- there is no context type and the removal of the spurious
11935 -- operations must be done explicitly here.
11937 if not Address_Is_Private
11938 and then Is_Descendent_Of_Address (It.Typ)
11943 Get_Next_Interp (I, It);
11947 Get_First_Interp (Operand, I, It);
11951 if No (It.Typ) then
11952 Conversion_Error_N ("illegal operand in conversion", Operand);
11956 Get_Next_Interp (I, It);
11958 if Present (It.Typ) then
11961 It1 := Disambiguate (Operand, I1, I, Any_Type);
11963 if It1 = No_Interp then
11965 ("ambiguous operand in conversion", Operand);
11967 -- If the interpretation involves a standard operator, use
11968 -- the location of the type, which may be user-defined.
11970 if Sloc (It.Nam) = Standard_Location then
11971 Error_Msg_Sloc := Sloc (It.Typ);
11973 Error_Msg_Sloc := Sloc (It.Nam);
11976 Conversion_Error_N -- CODEFIX
11977 ("\\possible interpretation#!", Operand);
11979 if Sloc (N1) = Standard_Location then
11980 Error_Msg_Sloc := Sloc (T1);
11982 Error_Msg_Sloc := Sloc (N1);
11985 Conversion_Error_N -- CODEFIX
11986 ("\\possible interpretation#!", Operand);
11992 Set_Etype (Operand, It1.Typ);
11993 Opnd_Type := It1.Typ;
11997 -- Deal with conversion of integer type to address if the pragma
11998 -- Allow_Integer_Address is in effect. We convert the conversion to
11999 -- an unchecked conversion in this case and we are all done.
12001 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12002 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12003 Analyze_And_Resolve (N, Target_Type);
12007 -- If we are within a child unit, check whether the type of the
12008 -- expression has an ancestor in a parent unit, in which case it
12009 -- belongs to its derivation class even if the ancestor is private.
12010 -- See RM 7.3.1 (5.2/3).
12012 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12016 if Is_Numeric_Type (Target_Type) then
12018 -- A universal fixed expression can be converted to any numeric type
12020 if Opnd_Type = Universal_Fixed then
12023 -- Also no need to check when in an instance or inlined body, because
12024 -- the legality has been established when the template was analyzed.
12025 -- Furthermore, numeric conversions may occur where only a private
12026 -- view of the operand type is visible at the instantiation point.
12027 -- This results in a spurious error if we check that the operand type
12028 -- is a numeric type.
12030 -- Note: in a previous version of this unit, the following tests were
12031 -- applied only for generated code (Comes_From_Source set to False),
12032 -- but in fact the test is required for source code as well, since
12033 -- this situation can arise in source code.
12035 elsif In_Instance or else In_Inlined_Body then
12038 -- Otherwise we need the conversion check
12041 return Conversion_Check
12042 (Is_Numeric_Type (Opnd_Type)
12044 (Present (Inc_Ancestor)
12045 and then Is_Numeric_Type (Inc_Ancestor)),
12046 "illegal operand for numeric conversion");
12051 elsif Is_Array_Type (Target_Type) then
12052 if not Is_Array_Type (Opnd_Type)
12053 or else Opnd_Type = Any_Composite
12054 or else Opnd_Type = Any_String
12057 ("illegal operand for array conversion", Operand);
12061 return Valid_Array_Conversion;
12064 -- Ada 2005 (AI-251): Internally generated conversions of access to
12065 -- interface types added to force the displacement of the pointer to
12066 -- reference the corresponding dispatch table.
12068 elsif not Comes_From_Source (N)
12069 and then Is_Access_Type (Target_Type)
12070 and then Is_Interface (Designated_Type (Target_Type))
12074 -- Ada 2005 (AI-251): Anonymous access types where target references an
12077 elsif Is_Access_Type (Opnd_Type)
12078 and then Ekind_In (Target_Type, E_General_Access_Type,
12079 E_Anonymous_Access_Type)
12080 and then Is_Interface (Directly_Designated_Type (Target_Type))
12082 -- Check the static accessibility rule of 4.6(17). Note that the
12083 -- check is not enforced when within an instance body, since the
12084 -- RM requires such cases to be caught at run time.
12086 -- If the operand is a rewriting of an allocator no check is needed
12087 -- because there are no accessibility issues.
12089 if Nkind (Original_Node (N)) = N_Allocator then
12092 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12093 if Type_Access_Level (Opnd_Type) >
12094 Deepest_Type_Access_Level (Target_Type)
12096 -- In an instance, this is a run-time check, but one we know
12097 -- will fail, so generate an appropriate warning. The raise
12098 -- will be generated by Expand_N_Type_Conversion.
12100 if In_Instance_Body then
12101 Error_Msg_Warn := SPARK_Mode /= On;
12103 ("cannot convert local pointer to non-local access type<<",
12105 Conversion_Error_N ("\Program_Error [<<", Operand);
12109 ("cannot convert local pointer to non-local access type",
12114 -- Special accessibility checks are needed in the case of access
12115 -- discriminants declared for a limited type.
12117 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12118 and then not Is_Local_Anonymous_Access (Opnd_Type)
12120 -- When the operand is a selected access discriminant the check
12121 -- needs to be made against the level of the object denoted by
12122 -- the prefix of the selected name (Object_Access_Level handles
12123 -- checking the prefix of the operand for this case).
12125 if Nkind (Operand) = N_Selected_Component
12126 and then Object_Access_Level (Operand) >
12127 Deepest_Type_Access_Level (Target_Type)
12129 -- In an instance, this is a run-time check, but one we know
12130 -- will fail, so generate an appropriate warning. The raise
12131 -- will be generated by Expand_N_Type_Conversion.
12133 if In_Instance_Body then
12134 Error_Msg_Warn := SPARK_Mode /= On;
12136 ("cannot convert access discriminant to non-local "
12137 & "access type<<", Operand);
12138 Conversion_Error_N ("\Program_Error [<<", Operand);
12140 -- Real error if not in instance body
12144 ("cannot convert access discriminant to non-local "
12145 & "access type", Operand);
12150 -- The case of a reference to an access discriminant from
12151 -- within a limited type declaration (which will appear as
12152 -- a discriminal) is always illegal because the level of the
12153 -- discriminant is considered to be deeper than any (nameable)
12156 if Is_Entity_Name (Operand)
12157 and then not Is_Local_Anonymous_Access (Opnd_Type)
12159 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12160 and then Present (Discriminal_Link (Entity (Operand)))
12163 ("discriminant has deeper accessibility level than target",
12172 -- General and anonymous access types
12174 elsif Ekind_In (Target_Type, E_General_Access_Type,
12175 E_Anonymous_Access_Type)
12178 (Is_Access_Type (Opnd_Type)
12180 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12181 E_Access_Protected_Subprogram_Type),
12182 "must be an access-to-object type")
12184 if Is_Access_Constant (Opnd_Type)
12185 and then not Is_Access_Constant (Target_Type)
12188 ("access-to-constant operand type not allowed", Operand);
12192 -- Check the static accessibility rule of 4.6(17). Note that the
12193 -- check is not enforced when within an instance body, since the RM
12194 -- requires such cases to be caught at run time.
12196 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12197 or else Is_Local_Anonymous_Access (Target_Type)
12198 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12199 N_Object_Declaration
12201 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12202 -- conversions from an anonymous access type to a named general
12203 -- access type. Such conversions are not allowed in the case of
12204 -- access parameters and stand-alone objects of an anonymous
12205 -- access type. The implicit conversion case is recognized by
12206 -- testing that Comes_From_Source is False and that it's been
12207 -- rewritten. The Comes_From_Source test isn't sufficient because
12208 -- nodes in inlined calls to predefined library routines can have
12209 -- Comes_From_Source set to False. (Is there a better way to test
12210 -- for implicit conversions???)
12212 if Ada_Version >= Ada_2012
12213 and then not Comes_From_Source (N)
12214 and then N /= Original_Node (N)
12215 and then Ekind (Target_Type) = E_General_Access_Type
12216 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12218 if Is_Itype (Opnd_Type) then
12220 -- Implicit conversions aren't allowed for objects of an
12221 -- anonymous access type, since such objects have nonstatic
12222 -- levels in Ada 2012.
12224 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12225 N_Object_Declaration
12228 ("implicit conversion of stand-alone anonymous "
12229 & "access object not allowed", Operand);
12232 -- Implicit conversions aren't allowed for anonymous access
12233 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12234 -- is done to exclude anonymous access results.
12236 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12237 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12238 N_Function_Specification,
12239 N_Procedure_Specification)
12242 ("implicit conversion of anonymous access formal "
12243 & "not allowed", Operand);
12246 -- This is a case where there's an enclosing object whose
12247 -- to which the "statically deeper than" relationship does
12248 -- not apply (such as an access discriminant selected from
12249 -- a dereference of an access parameter).
12251 elsif Object_Access_Level (Operand)
12252 = Scope_Depth (Standard_Standard)
12255 ("implicit conversion of anonymous access value "
12256 & "not allowed", Operand);
12259 -- In other cases, the level of the operand's type must be
12260 -- statically less deep than that of the target type, else
12261 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12263 elsif Type_Access_Level (Opnd_Type) >
12264 Deepest_Type_Access_Level (Target_Type)
12267 ("implicit conversion of anonymous access value "
12268 & "violates accessibility", Operand);
12273 elsif Type_Access_Level (Opnd_Type) >
12274 Deepest_Type_Access_Level (Target_Type)
12276 -- In an instance, this is a run-time check, but one we know
12277 -- will fail, so generate an appropriate warning. The raise
12278 -- will be generated by Expand_N_Type_Conversion.
12280 if In_Instance_Body then
12281 Error_Msg_Warn := SPARK_Mode /= On;
12283 ("cannot convert local pointer to non-local access type<<",
12285 Conversion_Error_N ("\Program_Error [<<", Operand);
12287 -- If not in an instance body, this is a real error
12290 -- Avoid generation of spurious error message
12292 if not Error_Posted (N) then
12294 ("cannot convert local pointer to non-local access type",
12301 -- Special accessibility checks are needed in the case of access
12302 -- discriminants declared for a limited type.
12304 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12305 and then not Is_Local_Anonymous_Access (Opnd_Type)
12307 -- When the operand is a selected access discriminant the check
12308 -- needs to be made against the level of the object denoted by
12309 -- the prefix of the selected name (Object_Access_Level handles
12310 -- checking the prefix of the operand for this case).
12312 if Nkind (Operand) = N_Selected_Component
12313 and then Object_Access_Level (Operand) >
12314 Deepest_Type_Access_Level (Target_Type)
12316 -- In an instance, this is a run-time check, but one we know
12317 -- will fail, so generate an appropriate warning. The raise
12318 -- will be generated by Expand_N_Type_Conversion.
12320 if In_Instance_Body then
12321 Error_Msg_Warn := SPARK_Mode /= On;
12323 ("cannot convert access discriminant to non-local "
12324 & "access type<<", Operand);
12325 Conversion_Error_N ("\Program_Error [<<", Operand);
12327 -- If not in an instance body, this is a real error
12331 ("cannot convert access discriminant to non-local "
12332 & "access type", Operand);
12337 -- The case of a reference to an access discriminant from
12338 -- within a limited type declaration (which will appear as
12339 -- a discriminal) is always illegal because the level of the
12340 -- discriminant is considered to be deeper than any (nameable)
12343 if Is_Entity_Name (Operand)
12345 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12346 and then Present (Discriminal_Link (Entity (Operand)))
12349 ("discriminant has deeper accessibility level than target",
12356 -- In the presence of limited_with clauses we have to use nonlimited
12357 -- views, if available.
12359 Check_Limited : declare
12360 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12361 -- Helper function to handle limited views
12363 --------------------------
12364 -- Full_Designated_Type --
12365 --------------------------
12367 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12368 Desig : constant Entity_Id := Designated_Type (T);
12371 -- Handle the limited view of a type
12373 if From_Limited_With (Desig)
12374 and then Has_Non_Limited_View (Desig)
12376 return Available_View (Desig);
12380 end Full_Designated_Type;
12382 -- Local Declarations
12384 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12385 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12387 Same_Base : constant Boolean :=
12388 Base_Type (Target) = Base_Type (Opnd);
12390 -- Start of processing for Check_Limited
12393 if Is_Tagged_Type (Target) then
12394 return Valid_Tagged_Conversion (Target, Opnd);
12397 if not Same_Base then
12398 Conversion_Error_NE
12399 ("target designated type not compatible with }",
12400 N, Base_Type (Opnd));
12403 -- Ada 2005 AI-384: legality rule is symmetric in both
12404 -- designated types. The conversion is legal (with possible
12405 -- constraint check) if either designated type is
12408 elsif Subtypes_Statically_Match (Target, Opnd)
12410 (Has_Discriminants (Target)
12412 (not Is_Constrained (Opnd)
12413 or else not Is_Constrained (Target)))
12415 -- Special case, if Value_Size has been used to make the
12416 -- sizes different, the conversion is not allowed even
12417 -- though the subtypes statically match.
12419 if Known_Static_RM_Size (Target)
12420 and then Known_Static_RM_Size (Opnd)
12421 and then RM_Size (Target) /= RM_Size (Opnd)
12423 Conversion_Error_NE
12424 ("target designated subtype not compatible with }",
12426 Conversion_Error_NE
12427 ("\because sizes of the two designated subtypes differ",
12431 -- Normal case where conversion is allowed
12439 ("target designated subtype not compatible with }",
12446 -- Access to subprogram types. If the operand is an access parameter,
12447 -- the type has a deeper accessibility that any master, and cannot be
12448 -- assigned. We must make an exception if the conversion is part of an
12449 -- assignment and the target is the return object of an extended return
12450 -- statement, because in that case the accessibility check takes place
12451 -- after the return.
12453 elsif Is_Access_Subprogram_Type (Target_Type)
12455 -- Note: this test of Opnd_Type is there to prevent entering this
12456 -- branch in the case of a remote access to subprogram type, which
12457 -- is internally represented as an E_Record_Type.
12459 and then Is_Access_Type (Opnd_Type)
12461 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12462 and then Is_Entity_Name (Operand)
12463 and then Ekind (Entity (Operand)) = E_In_Parameter
12465 (Nkind (Parent (N)) /= N_Assignment_Statement
12466 or else not Is_Entity_Name (Name (Parent (N)))
12467 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12470 ("illegal attempt to store anonymous access to subprogram",
12473 ("\value has deeper accessibility than any master "
12474 & "(RM 3.10.2 (13))",
12478 ("\use named access type for& instead of access parameter",
12479 Operand, Entity (Operand));
12482 -- Check that the designated types are subtype conformant
12484 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12485 Old_Id => Designated_Type (Opnd_Type),
12488 -- Check the static accessibility rule of 4.6(20)
12490 if Type_Access_Level (Opnd_Type) >
12491 Deepest_Type_Access_Level (Target_Type)
12494 ("operand type has deeper accessibility level than target",
12497 -- Check that if the operand type is declared in a generic body,
12498 -- then the target type must be declared within that same body
12499 -- (enforces last sentence of 4.6(20)).
12501 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12503 O_Gen : constant Node_Id :=
12504 Enclosing_Generic_Body (Opnd_Type);
12509 T_Gen := Enclosing_Generic_Body (Target_Type);
12510 while Present (T_Gen) and then T_Gen /= O_Gen loop
12511 T_Gen := Enclosing_Generic_Body (T_Gen);
12514 if T_Gen /= O_Gen then
12516 ("target type must be declared in same generic body "
12517 & "as operand type", N);
12524 -- Remote access to subprogram types
12526 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12527 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12529 -- It is valid to convert from one RAS type to another provided
12530 -- that their specification statically match.
12532 -- Note: at this point, remote access to subprogram types have been
12533 -- expanded to their E_Record_Type representation, and we need to
12534 -- go back to the original access type definition using the
12535 -- Corresponding_Remote_Type attribute in order to check that the
12536 -- designated profiles match.
12538 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12539 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12541 Check_Subtype_Conformant
12543 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12545 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12550 -- If it was legal in the generic, it's legal in the instance
12552 elsif In_Instance_Body then
12555 -- If both are tagged types, check legality of view conversions
12557 elsif Is_Tagged_Type (Target_Type)
12559 Is_Tagged_Type (Opnd_Type)
12561 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12563 -- Types derived from the same root type are convertible
12565 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12568 -- In an instance or an inlined body, there may be inconsistent views of
12569 -- the same type, or of types derived from a common root.
12571 elsif (In_Instance or In_Inlined_Body)
12573 Root_Type (Underlying_Type (Target_Type)) =
12574 Root_Type (Underlying_Type (Opnd_Type))
12578 -- Special check for common access type error case
12580 elsif Ekind (Target_Type) = E_Access_Type
12581 and then Is_Access_Type (Opnd_Type)
12583 Conversion_Error_N ("target type must be general access type!", N);
12584 Conversion_Error_NE -- CODEFIX
12585 ("add ALL to }!", N, Target_Type);
12588 -- Here we have a real conversion error
12591 Conversion_Error_NE
12592 ("invalid conversion, not compatible with }", N, Opnd_Type);
12595 end Valid_Conversion;