1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2018, 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 Freeze; use Freeze;
39 with Ghost; use Ghost;
40 with Inline; use Inline;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Par_SCO; use Par_SCO;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
54 with Sem_Aux; use Sem_Aux;
55 with Sem_Aggr; use Sem_Aggr;
56 with Sem_Attr; use Sem_Attr;
57 with Sem_Cat; use Sem_Cat;
58 with Sem_Ch4; use Sem_Ch4;
59 with Sem_Ch3; use Sem_Ch3;
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_Elab; use Sem_Elab;
67 with Sem_Elim; use Sem_Elim;
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_No_Direct_Boolean_Operators (N : Node_Id);
121 -- N is the node for a logical operator. If the operator is predefined, and
122 -- the root type of the operands is Standard.Boolean, then a check is made
123 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
124 -- the style check for Style_Check_Boolean_And_Or.
126 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
127 -- N is either an indexed component or a selected component. This function
128 -- returns true if the prefix refers to an object that has an address
129 -- clause (the case in which we may want to issue a warning).
131 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
132 -- Determine whether E is an access type declared by an access declaration,
133 -- and not an (anonymous) allocator type.
135 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
136 -- Utility to check whether the entity for an operator is a predefined
137 -- operator, in which case the expression is left as an operator in the
138 -- tree (else it is rewritten into a call). An instance of an intrinsic
139 -- conversion operation may be given an operator name, but is not treated
140 -- like an operator. Note that an operator that is an imported back-end
141 -- builtin has convention Intrinsic, but is expected to be rewritten into
142 -- a call, so such an operator is not treated as predefined by this
145 procedure Preanalyze_And_Resolve
148 With_Freezing : Boolean);
149 -- Subsidiary of public versions of Preanalyze_And_Resolve.
151 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
152 -- If a default expression in entry call N depends on the discriminants
153 -- of the task, it must be replaced with a reference to the discriminant
154 -- of the task being called.
156 procedure Resolve_Op_Concat_Arg
161 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
162 -- concatenation operator. The operand is either of the array type or of
163 -- the component type. If the operand is an aggregate, and the component
164 -- type is composite, this is ambiguous if component type has aggregates.
166 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
167 -- Does the first part of the work of Resolve_Op_Concat
169 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
170 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
171 -- has been resolved. See Resolve_Op_Concat for details.
173 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Target_Name (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_No_Direct_Boolean_Operators --
862 ---------------------------------------
864 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
866 if Scope (Entity (N)) = Standard_Standard
867 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
869 -- Restriction only applies to original source code
871 if Comes_From_Source (N) then
872 Check_Restriction (No_Direct_Boolean_Operators, N);
876 -- Do style check (but skip if in instance, error is on template)
879 if not In_Instance then
880 Check_Boolean_Operator (N);
883 end Check_No_Direct_Boolean_Operators;
885 ------------------------------
886 -- Check_Parameterless_Call --
887 ------------------------------
889 procedure Check_Parameterless_Call (N : Node_Id) is
892 function Prefix_Is_Access_Subp return Boolean;
893 -- If the prefix is of an access_to_subprogram type, the node must be
894 -- rewritten as a call. Ditto if the prefix is overloaded and all its
895 -- interpretations are access to subprograms.
897 ---------------------------
898 -- Prefix_Is_Access_Subp --
899 ---------------------------
901 function Prefix_Is_Access_Subp return Boolean is
906 -- If the context is an attribute reference that can apply to
907 -- functions, this is never a parameterless call (RM 4.1.4(6)).
909 if Nkind (Parent (N)) = N_Attribute_Reference
910 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
917 if not Is_Overloaded (N) then
919 Ekind (Etype (N)) = E_Subprogram_Type
920 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
922 Get_First_Interp (N, I, It);
923 while Present (It.Typ) loop
924 if Ekind (It.Typ) /= E_Subprogram_Type
925 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
930 Get_Next_Interp (I, It);
935 end Prefix_Is_Access_Subp;
937 -- Start of processing for Check_Parameterless_Call
940 -- Defend against junk stuff if errors already detected
942 if Total_Errors_Detected /= 0 then
943 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
945 elsif Nkind (N) in N_Has_Chars
946 and then not Is_Valid_Name (Chars (N))
954 -- If the context expects a value, and the name is a procedure, this is
955 -- most likely a missing 'Access. Don't try to resolve the parameterless
956 -- call, error will be caught when the outer call is analyzed.
958 if Is_Entity_Name (N)
959 and then Ekind (Entity (N)) = E_Procedure
960 and then not Is_Overloaded (N)
962 Nkind_In (Parent (N), N_Parameter_Association,
964 N_Procedure_Call_Statement)
969 -- Rewrite as call if overloadable entity that is (or could be, in the
970 -- overloaded case) a function call. If we know for sure that the entity
971 -- is an enumeration literal, we do not rewrite it.
973 -- If the entity is the name of an operator, it cannot be a call because
974 -- operators cannot have default parameters. In this case, this must be
975 -- a string whose contents coincide with an operator name. Set the kind
976 -- of the node appropriately.
978 if (Is_Entity_Name (N)
979 and then Nkind (N) /= N_Operator_Symbol
980 and then Is_Overloadable (Entity (N))
981 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
982 or else Is_Overloaded (N)))
984 -- Rewrite as call if it is an explicit dereference of an expression of
985 -- a subprogram access type, and the subprogram type is not that of a
986 -- procedure or entry.
989 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
991 -- Rewrite as call if it is a selected component which is a function,
992 -- this is the case of a call to a protected function (which may be
993 -- overloaded with other protected operations).
996 (Nkind (N) = N_Selected_Component
997 and then (Ekind (Entity (Selector_Name (N))) = E_Function
999 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1001 and then Is_Overloaded (Selector_Name (N)))))
1003 -- If one of the above three conditions is met, rewrite as call. Apply
1004 -- the rewriting only once.
1007 if Nkind (Parent (N)) /= N_Function_Call
1008 or else N /= Name (Parent (N))
1011 -- This may be a prefixed call that was not fully analyzed, e.g.
1012 -- an actual in an instance.
1014 if Ada_Version >= Ada_2005
1015 and then Nkind (N) = N_Selected_Component
1016 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1018 Analyze_Selected_Component (N);
1020 if Nkind (N) /= N_Selected_Component then
1025 -- The node is the name of the parameterless call. Preserve its
1026 -- descendants, which may be complex expressions.
1028 Nam := Relocate_Node (N);
1030 -- If overloaded, overload set belongs to new copy
1032 Save_Interps (N, Nam);
1034 -- Change node to parameterless function call (note that the
1035 -- Parameter_Associations associations field is left set to Empty,
1036 -- its normal default value since there are no parameters)
1038 Change_Node (N, N_Function_Call);
1040 Set_Sloc (N, Sloc (Nam));
1044 elsif Nkind (N) = N_Parameter_Association then
1045 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1047 elsif Nkind (N) = N_Operator_Symbol then
1048 Change_Operator_Symbol_To_String_Literal (N);
1049 Set_Is_Overloaded (N, False);
1050 Set_Etype (N, Any_String);
1052 end Check_Parameterless_Call;
1054 --------------------------------
1055 -- Is_Atomic_Ref_With_Address --
1056 --------------------------------
1058 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1059 Pref : constant Node_Id := Prefix (N);
1062 if not Is_Entity_Name (Pref) then
1067 Pent : constant Entity_Id := Entity (Pref);
1068 Ptyp : constant Entity_Id := Etype (Pent);
1070 return not Is_Access_Type (Ptyp)
1071 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1072 and then Present (Address_Clause (Pent));
1075 end Is_Atomic_Ref_With_Address;
1077 -----------------------------
1078 -- Is_Definite_Access_Type --
1079 -----------------------------
1081 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1082 Btyp : constant Entity_Id := Base_Type (E);
1084 return Ekind (Btyp) = E_Access_Type
1085 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1086 and then Comes_From_Source (Btyp));
1087 end Is_Definite_Access_Type;
1089 ----------------------
1090 -- Is_Predefined_Op --
1091 ----------------------
1093 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1095 -- Predefined operators are intrinsic subprograms
1097 if not Is_Intrinsic_Subprogram (Nam) then
1101 -- A call to a back-end builtin is never a predefined operator
1103 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1107 return not Is_Generic_Instance (Nam)
1108 and then Chars (Nam) in Any_Operator_Name
1109 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1110 end Is_Predefined_Op;
1112 -----------------------------
1113 -- Make_Call_Into_Operator --
1114 -----------------------------
1116 procedure Make_Call_Into_Operator
1121 Op_Name : constant Name_Id := Chars (Op_Id);
1122 Act1 : Node_Id := First_Actual (N);
1123 Act2 : Node_Id := Next_Actual (Act1);
1124 Error : Boolean := False;
1125 Func : constant Entity_Id := Entity (Name (N));
1126 Is_Binary : constant Boolean := Present (Act2);
1128 Opnd_Type : Entity_Id := Empty;
1129 Orig_Type : Entity_Id := Empty;
1132 type Kind_Test is access function (E : Entity_Id) return Boolean;
1134 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1135 -- If the operand is not universal, and the operator is given by an
1136 -- expanded name, verify that the operand has an interpretation with a
1137 -- type defined in the given scope of the operator.
1139 function Type_In_P (Test : Kind_Test) return Entity_Id;
1140 -- Find a type of the given class in package Pack that contains the
1143 ---------------------------
1144 -- Operand_Type_In_Scope --
1145 ---------------------------
1147 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1148 Nod : constant Node_Id := Right_Opnd (Op_Node);
1153 if not Is_Overloaded (Nod) then
1154 return Scope (Base_Type (Etype (Nod))) = S;
1157 Get_First_Interp (Nod, I, It);
1158 while Present (It.Typ) loop
1159 if Scope (Base_Type (It.Typ)) = S then
1163 Get_Next_Interp (I, It);
1168 end Operand_Type_In_Scope;
1174 function Type_In_P (Test : Kind_Test) return Entity_Id is
1177 function In_Decl return Boolean;
1178 -- Verify that node is not part of the type declaration for the
1179 -- candidate type, which would otherwise be invisible.
1185 function In_Decl return Boolean is
1186 Decl_Node : constant Node_Id := Parent (E);
1192 if Etype (E) = Any_Type then
1195 elsif No (Decl_Node) then
1200 and then Nkind (N2) /= N_Compilation_Unit
1202 if N2 = Decl_Node then
1213 -- Start of processing for Type_In_P
1216 -- If the context type is declared in the prefix package, this is the
1217 -- desired base type.
1219 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1220 return Base_Type (Typ);
1223 E := First_Entity (Pack);
1224 while Present (E) loop
1225 if Test (E) and then not In_Decl then
1236 -- Start of processing for Make_Call_Into_Operator
1239 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1241 -- Ensure that the corresponding operator has the same parent as the
1242 -- original call. This guarantees that parent traversals performed by
1243 -- the ABE mechanism succeed.
1245 Set_Parent (Op_Node, Parent (N));
1250 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1251 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1252 Save_Interps (Act1, Left_Opnd (Op_Node));
1253 Save_Interps (Act2, Right_Opnd (Op_Node));
1254 Act1 := Left_Opnd (Op_Node);
1255 Act2 := Right_Opnd (Op_Node);
1260 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1261 Save_Interps (Act1, Right_Opnd (Op_Node));
1262 Act1 := Right_Opnd (Op_Node);
1265 -- If the operator is denoted by an expanded name, and the prefix is
1266 -- not Standard, but the operator is a predefined one whose scope is
1267 -- Standard, then this is an implicit_operator, inserted as an
1268 -- interpretation by the procedure of the same name. This procedure
1269 -- overestimates the presence of implicit operators, because it does
1270 -- not examine the type of the operands. Verify now that the operand
1271 -- type appears in the given scope. If right operand is universal,
1272 -- check the other operand. In the case of concatenation, either
1273 -- argument can be the component type, so check the type of the result.
1274 -- If both arguments are literals, look for a type of the right kind
1275 -- defined in the given scope. This elaborate nonsense is brought to
1276 -- you courtesy of b33302a. The type itself must be frozen, so we must
1277 -- find the type of the proper class in the given scope.
1279 -- A final wrinkle is the multiplication operator for fixed point types,
1280 -- which is defined in Standard only, and not in the scope of the
1281 -- fixed point type itself.
1283 if Nkind (Name (N)) = N_Expanded_Name then
1284 Pack := Entity (Prefix (Name (N)));
1286 -- If this is a package renaming, get renamed entity, which will be
1287 -- the scope of the operands if operaton is type-correct.
1289 if Present (Renamed_Entity (Pack)) then
1290 Pack := Renamed_Entity (Pack);
1293 -- If the entity being called is defined in the given package, it is
1294 -- a renaming of a predefined operator, and known to be legal.
1296 if Scope (Entity (Name (N))) = Pack
1297 and then Pack /= Standard_Standard
1301 -- Visibility does not need to be checked in an instance: if the
1302 -- operator was not visible in the generic it has been diagnosed
1303 -- already, else there is an implicit copy of it in the instance.
1305 elsif In_Instance then
1308 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1309 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1310 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1312 if Pack /= Standard_Standard then
1316 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1319 elsif Ada_Version >= Ada_2005
1320 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1321 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1326 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1328 if Op_Name = Name_Op_Concat then
1329 Opnd_Type := Base_Type (Typ);
1331 elsif (Scope (Opnd_Type) = Standard_Standard
1333 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1335 and then not Comes_From_Source (Opnd_Type))
1337 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1340 if Scope (Opnd_Type) = Standard_Standard then
1342 -- Verify that the scope contains a type that corresponds to
1343 -- the given literal. Optimize the case where Pack is Standard.
1345 if Pack /= Standard_Standard then
1346 if Opnd_Type = Universal_Integer then
1347 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1349 elsif Opnd_Type = Universal_Real then
1350 Orig_Type := Type_In_P (Is_Real_Type'Access);
1352 elsif Opnd_Type = Any_String then
1353 Orig_Type := Type_In_P (Is_String_Type'Access);
1355 elsif Opnd_Type = Any_Access then
1356 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1358 elsif Opnd_Type = Any_Composite then
1359 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1361 if Present (Orig_Type) then
1362 if Has_Private_Component (Orig_Type) then
1365 Set_Etype (Act1, Orig_Type);
1368 Set_Etype (Act2, Orig_Type);
1377 Error := No (Orig_Type);
1380 elsif Ekind (Opnd_Type) = E_Allocator_Type
1381 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1385 -- If the type is defined elsewhere, and the operator is not
1386 -- defined in the given scope (by a renaming declaration, e.g.)
1387 -- then this is an error as well. If an extension of System is
1388 -- present, and the type may be defined there, Pack must be
1391 elsif Scope (Opnd_Type) /= Pack
1392 and then Scope (Op_Id) /= Pack
1393 and then (No (System_Aux_Id)
1394 or else Scope (Opnd_Type) /= System_Aux_Id
1395 or else Pack /= Scope (System_Aux_Id))
1397 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1400 Error := not Operand_Type_In_Scope (Pack);
1403 elsif Pack = Standard_Standard
1404 and then not Operand_Type_In_Scope (Standard_Standard)
1411 Error_Msg_Node_2 := Pack;
1413 ("& not declared in&", N, Selector_Name (Name (N)));
1414 Set_Etype (N, Any_Type);
1417 -- Detect a mismatch between the context type and the result type
1418 -- in the named package, which is otherwise not detected if the
1419 -- operands are universal. Check is only needed if source entity is
1420 -- an operator, not a function that renames an operator.
1422 elsif Nkind (Parent (N)) /= N_Type_Conversion
1423 and then Ekind (Entity (Name (N))) = E_Operator
1424 and then Is_Numeric_Type (Typ)
1425 and then not Is_Universal_Numeric_Type (Typ)
1426 and then Scope (Base_Type (Typ)) /= Pack
1427 and then not In_Instance
1429 if Is_Fixed_Point_Type (Typ)
1430 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1432 -- Already checked above
1436 -- Operator may be defined in an extension of System
1438 elsif Present (System_Aux_Id)
1439 and then Present (Opnd_Type)
1440 and then Scope (Opnd_Type) = System_Aux_Id
1445 -- Could we use Wrong_Type here??? (this would require setting
1446 -- Etype (N) to the actual type found where Typ was expected).
1448 Error_Msg_NE ("expect }", N, Typ);
1453 Set_Chars (Op_Node, Op_Name);
1455 if not Is_Private_Type (Etype (N)) then
1456 Set_Etype (Op_Node, Base_Type (Etype (N)));
1458 Set_Etype (Op_Node, Etype (N));
1461 -- If this is a call to a function that renames a predefined equality,
1462 -- the renaming declaration provides a type that must be used to
1463 -- resolve the operands. This must be done now because resolution of
1464 -- the equality node will not resolve any remaining ambiguity, and it
1465 -- assumes that the first operand is not overloaded.
1467 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1468 and then Ekind (Func) = E_Function
1469 and then Is_Overloaded (Act1)
1471 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1472 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1475 Set_Entity (Op_Node, Op_Id);
1476 Generate_Reference (Op_Id, N, ' ');
1478 -- Do rewrite setting Comes_From_Source on the result if the original
1479 -- call came from source. Although it is not strictly the case that the
1480 -- operator as such comes from the source, logically it corresponds
1481 -- exactly to the function call in the source, so it should be marked
1482 -- this way (e.g. to make sure that validity checks work fine).
1485 CS : constant Boolean := Comes_From_Source (N);
1487 Rewrite (N, Op_Node);
1488 Set_Comes_From_Source (N, CS);
1491 -- If this is an arithmetic operator and the result type is private,
1492 -- the operands and the result must be wrapped in conversion to
1493 -- expose the underlying numeric type and expand the proper checks,
1494 -- e.g. on division.
1496 if Is_Private_Type (Typ) then
1506 Resolve_Intrinsic_Operator (N, Typ);
1512 Resolve_Intrinsic_Unary_Operator (N, Typ);
1521 -- If in ASIS_Mode, propagate operand types to original actuals of
1522 -- function call, which would otherwise not be fully resolved. If
1523 -- the call has already been constant-folded, nothing to do. We
1524 -- relocate the operand nodes rather than copy them, to preserve
1525 -- original_node pointers, given that the operands themselves may
1526 -- have been rewritten. If the call was itself a rewriting of an
1527 -- operator node, nothing to do.
1530 and then Nkind (N) in N_Op
1531 and then Nkind (Original_Node (N)) = N_Function_Call
1535 R : constant Node_Id := Right_Opnd (N);
1537 Old_First : constant Node_Id :=
1538 First (Parameter_Associations (Original_Node (N)));
1544 Old_Sec := Next (Old_First);
1546 -- If the original call has named associations, replace the
1547 -- explicit actual parameter in the association with the proper
1548 -- resolved operand.
1550 if Nkind (Old_First) = N_Parameter_Association then
1551 if Chars (Selector_Name (Old_First)) =
1552 Chars (First_Entity (Op_Id))
1554 Rewrite (Explicit_Actual_Parameter (Old_First),
1557 Rewrite (Explicit_Actual_Parameter (Old_First),
1562 Rewrite (Old_First, Relocate_Node (L));
1565 if Nkind (Old_Sec) = N_Parameter_Association then
1566 if Chars (Selector_Name (Old_Sec)) =
1567 Chars (First_Entity (Op_Id))
1569 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1572 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1577 Rewrite (Old_Sec, Relocate_Node (R));
1581 if Nkind (Old_First) = N_Parameter_Association then
1582 Rewrite (Explicit_Actual_Parameter (Old_First),
1585 Rewrite (Old_First, Relocate_Node (R));
1590 Set_Parent (Original_Node (N), Parent (N));
1592 end Make_Call_Into_Operator;
1598 function Operator_Kind
1600 Is_Binary : Boolean) return Node_Kind
1605 -- Use CASE statement or array???
1608 if Op_Name = Name_Op_And then
1610 elsif Op_Name = Name_Op_Or then
1612 elsif Op_Name = Name_Op_Xor then
1614 elsif Op_Name = Name_Op_Eq then
1616 elsif Op_Name = Name_Op_Ne then
1618 elsif Op_Name = Name_Op_Lt then
1620 elsif Op_Name = Name_Op_Le then
1622 elsif Op_Name = Name_Op_Gt then
1624 elsif Op_Name = Name_Op_Ge then
1626 elsif Op_Name = Name_Op_Add then
1628 elsif Op_Name = Name_Op_Subtract then
1629 Kind := N_Op_Subtract;
1630 elsif Op_Name = Name_Op_Concat then
1631 Kind := N_Op_Concat;
1632 elsif Op_Name = Name_Op_Multiply then
1633 Kind := N_Op_Multiply;
1634 elsif Op_Name = Name_Op_Divide then
1635 Kind := N_Op_Divide;
1636 elsif Op_Name = Name_Op_Mod then
1638 elsif Op_Name = Name_Op_Rem then
1640 elsif Op_Name = Name_Op_Expon then
1643 raise Program_Error;
1649 if Op_Name = Name_Op_Add then
1651 elsif Op_Name = Name_Op_Subtract then
1653 elsif Op_Name = Name_Op_Abs then
1655 elsif Op_Name = Name_Op_Not then
1658 raise Program_Error;
1665 ----------------------------
1666 -- Preanalyze_And_Resolve --
1667 ----------------------------
1669 procedure Preanalyze_And_Resolve
1672 With_Freezing : Boolean)
1674 Save_Full_Analysis : constant Boolean := Full_Analysis;
1675 Save_Must_Not_Freeze : constant Boolean := Must_Not_Freeze (N);
1676 Save_Preanalysis_Count : constant Nat :=
1677 Inside_Preanalysis_Without_Freezing;
1679 pragma Assert (Nkind (N) in N_Subexpr);
1681 if not With_Freezing then
1682 Set_Must_Not_Freeze (N);
1683 Inside_Preanalysis_Without_Freezing :=
1684 Inside_Preanalysis_Without_Freezing + 1;
1687 Full_Analysis := False;
1688 Expander_Mode_Save_And_Set (False);
1690 -- Normally, we suppress all checks for this preanalysis. There is no
1691 -- point in processing them now, since they will be applied properly
1692 -- and in the proper location when the default expressions reanalyzed
1693 -- and reexpanded later on. We will also have more information at that
1694 -- point for possible suppression of individual checks.
1696 -- However, in SPARK mode, most expansion is suppressed, and this
1697 -- later reanalysis and reexpansion may not occur. SPARK mode does
1698 -- require the setting of checking flags for proof purposes, so we
1699 -- do the SPARK preanalysis without suppressing checks.
1701 -- This special handling for SPARK mode is required for example in the
1702 -- case of Ada 2012 constructs such as quantified expressions, which are
1703 -- expanded in two separate steps.
1705 if GNATprove_Mode then
1706 Analyze_And_Resolve (N, T);
1708 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1711 Expander_Mode_Restore;
1712 Full_Analysis := Save_Full_Analysis;
1713 Set_Must_Not_Freeze (N, Save_Must_Not_Freeze);
1715 if not With_Freezing then
1716 Inside_Preanalysis_Without_Freezing :=
1717 Inside_Preanalysis_Without_Freezing - 1;
1721 (Inside_Preanalysis_Without_Freezing = Save_Preanalysis_Count);
1722 end Preanalyze_And_Resolve;
1724 ----------------------------
1725 -- Preanalyze_And_Resolve --
1726 ----------------------------
1728 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1730 Preanalyze_And_Resolve (N, T, With_Freezing => False);
1731 end Preanalyze_And_Resolve;
1733 -- Version without context type
1735 procedure Preanalyze_And_Resolve (N : Node_Id) is
1736 Save_Full_Analysis : constant Boolean := Full_Analysis;
1739 Full_Analysis := False;
1740 Expander_Mode_Save_And_Set (False);
1743 Resolve (N, Etype (N), Suppress => All_Checks);
1745 Expander_Mode_Restore;
1746 Full_Analysis := Save_Full_Analysis;
1747 end Preanalyze_And_Resolve;
1749 ------------------------------------------
1750 -- Preanalyze_With_Freezing_And_Resolve --
1751 ------------------------------------------
1753 procedure Preanalyze_With_Freezing_And_Resolve
1758 Preanalyze_And_Resolve (N, T, With_Freezing => True);
1759 end Preanalyze_With_Freezing_And_Resolve;
1761 ----------------------------------
1762 -- Replace_Actual_Discriminants --
1763 ----------------------------------
1765 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1766 Loc : constant Source_Ptr := Sloc (N);
1767 Tsk : Node_Id := Empty;
1769 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1770 -- Comment needed???
1776 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1780 if Nkind (Nod) = N_Identifier then
1781 Ent := Entity (Nod);
1784 and then Ekind (Ent) = E_Discriminant
1787 Make_Selected_Component (Loc,
1788 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1789 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1791 Set_Etype (Nod, Etype (Ent));
1799 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1801 -- Start of processing for Replace_Actual_Discriminants
1804 if Expander_Active then
1807 -- Allow the replacement of concurrent discriminants in GNATprove even
1808 -- though this is a light expansion activity. Note that generic units
1809 -- are not modified.
1811 elsif GNATprove_Mode and not Inside_A_Generic then
1818 if Nkind (Name (N)) = N_Selected_Component then
1819 Tsk := Prefix (Name (N));
1821 elsif Nkind (Name (N)) = N_Indexed_Component then
1822 Tsk := Prefix (Prefix (Name (N)));
1825 if Present (Tsk) then
1826 Replace_Discrs (Default);
1828 end Replace_Actual_Discriminants;
1834 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1835 Ambiguous : Boolean := False;
1836 Ctx_Type : Entity_Id := Typ;
1837 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1838 Err_Type : Entity_Id := Empty;
1839 Found : Boolean := False;
1842 I1 : Interp_Index := 0; -- prevent junk warning
1845 Seen : Entity_Id := Empty; -- prevent junk warning
1847 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1848 -- Determine whether a node comes from a predefined library unit or
1851 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1852 -- Try and fix up a literal so that it matches its expected type. New
1853 -- literals are manufactured if necessary to avoid cascaded errors.
1855 procedure Report_Ambiguous_Argument;
1856 -- Additional diagnostics when an ambiguous call has an ambiguous
1857 -- argument (typically a controlling actual).
1859 procedure Resolution_Failed;
1860 -- Called when attempt at resolving current expression fails
1862 ------------------------------------
1863 -- Comes_From_Predefined_Lib_Unit --
1864 -------------------------------------
1866 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1869 Sloc (Nod) = Standard_Location or else In_Predefined_Unit (Nod);
1870 end Comes_From_Predefined_Lib_Unit;
1872 --------------------
1873 -- Patch_Up_Value --
1874 --------------------
1876 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1878 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1880 Make_Real_Literal (Sloc (N),
1881 Realval => UR_From_Uint (Intval (N))));
1882 Set_Etype (N, Universal_Real);
1883 Set_Is_Static_Expression (N);
1885 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1887 Make_Integer_Literal (Sloc (N),
1888 Intval => UR_To_Uint (Realval (N))));
1889 Set_Etype (N, Universal_Integer);
1890 Set_Is_Static_Expression (N);
1892 elsif Nkind (N) = N_String_Literal
1893 and then Is_Character_Type (Typ)
1895 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1897 Make_Character_Literal (Sloc (N),
1899 Char_Literal_Value =>
1900 UI_From_Int (Character'Pos ('A'))));
1901 Set_Etype (N, Any_Character);
1902 Set_Is_Static_Expression (N);
1904 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1906 Make_String_Literal (Sloc (N),
1907 Strval => End_String));
1909 elsif Nkind (N) = N_Range then
1910 Patch_Up_Value (Low_Bound (N), Typ);
1911 Patch_Up_Value (High_Bound (N), Typ);
1915 -------------------------------
1916 -- Report_Ambiguous_Argument --
1917 -------------------------------
1919 procedure Report_Ambiguous_Argument is
1920 Arg : constant Node_Id := First (Parameter_Associations (N));
1925 if Nkind (Arg) = N_Function_Call
1926 and then Is_Entity_Name (Name (Arg))
1927 and then Is_Overloaded (Name (Arg))
1929 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1931 -- Could use comments on what is going on here???
1933 Get_First_Interp (Name (Arg), I, It);
1934 while Present (It.Nam) loop
1935 Error_Msg_Sloc := Sloc (It.Nam);
1937 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1938 Error_Msg_N ("interpretation (inherited) #!", Arg);
1940 Error_Msg_N ("interpretation #!", Arg);
1943 Get_Next_Interp (I, It);
1946 end Report_Ambiguous_Argument;
1948 -----------------------
1949 -- Resolution_Failed --
1950 -----------------------
1952 procedure Resolution_Failed is
1954 Patch_Up_Value (N, Typ);
1956 -- Set the type to the desired one to minimize cascaded errors. Note
1957 -- that this is an approximation and does not work in all cases.
1961 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1962 Set_Is_Overloaded (N, False);
1964 -- The caller will return without calling the expander, so we need
1965 -- to set the analyzed flag. Note that it is fine to set Analyzed
1966 -- to True even if we are in the middle of a shallow analysis,
1967 -- (see the spec of sem for more details) since this is an error
1968 -- situation anyway, and there is no point in repeating the
1969 -- analysis later (indeed it won't work to repeat it later, since
1970 -- we haven't got a clear resolution of which entity is being
1973 Set_Analyzed (N, True);
1975 end Resolution_Failed;
1977 -- Start of processing for Resolve
1984 -- Access attribute on remote subprogram cannot be used for a non-remote
1985 -- access-to-subprogram type.
1987 if Nkind (N) = N_Attribute_Reference
1988 and then Nam_In (Attribute_Name (N), Name_Access,
1989 Name_Unrestricted_Access,
1990 Name_Unchecked_Access)
1991 and then Comes_From_Source (N)
1992 and then Is_Entity_Name (Prefix (N))
1993 and then Is_Subprogram (Entity (Prefix (N)))
1994 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1995 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1998 ("prefix must statically denote a non-remote subprogram", N);
2001 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2003 -- If the context is a Remote_Access_To_Subprogram, access attributes
2004 -- must be resolved with the corresponding fat pointer. There is no need
2005 -- to check for the attribute name since the return type of an
2006 -- attribute is never a remote type.
2008 if Nkind (N) = N_Attribute_Reference
2009 and then Comes_From_Source (N)
2010 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2013 Attr : constant Attribute_Id :=
2014 Get_Attribute_Id (Attribute_Name (N));
2015 Pref : constant Node_Id := Prefix (N);
2018 Is_Remote : Boolean := True;
2021 -- Check that Typ is a remote access-to-subprogram type
2023 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2025 -- Prefix (N) must statically denote a remote subprogram
2026 -- declared in a package specification.
2028 if Attr = Attribute_Access or else
2029 Attr = Attribute_Unchecked_Access or else
2030 Attr = Attribute_Unrestricted_Access
2032 Decl := Unit_Declaration_Node (Entity (Pref));
2034 if Nkind (Decl) = N_Subprogram_Body then
2035 Spec := Corresponding_Spec (Decl);
2037 if Present (Spec) then
2038 Decl := Unit_Declaration_Node (Spec);
2042 Spec := Parent (Decl);
2044 if not Is_Entity_Name (Prefix (N))
2045 or else Nkind (Spec) /= N_Package_Specification
2047 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2051 ("prefix must statically denote a remote subprogram ",
2055 -- If we are generating code in distributed mode, perform
2056 -- semantic checks against corresponding remote entities.
2059 and then Get_PCS_Name /= Name_No_DSA
2061 Check_Subtype_Conformant
2062 (New_Id => Entity (Prefix (N)),
2063 Old_Id => Designated_Type
2064 (Corresponding_Remote_Type (Typ)),
2068 Process_Remote_AST_Attribute (N, Typ);
2076 Debug_A_Entry ("resolving ", N);
2078 if Debug_Flag_V then
2079 Write_Overloads (N);
2082 if Comes_From_Source (N) then
2083 if Is_Fixed_Point_Type (Typ) then
2084 Check_Restriction (No_Fixed_Point, N);
2086 elsif Is_Floating_Point_Type (Typ)
2087 and then Typ /= Universal_Real
2088 and then Typ /= Any_Real
2090 Check_Restriction (No_Floating_Point, N);
2094 -- Return if already analyzed
2096 if Analyzed (N) then
2097 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2098 Analyze_Dimension (N);
2101 -- Any case of Any_Type as the Etype value means that we had a
2104 elsif Etype (N) = Any_Type then
2105 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2109 Check_Parameterless_Call (N);
2111 -- The resolution of an Expression_With_Actions is determined by
2114 if Nkind (N) = N_Expression_With_Actions then
2115 Resolve (Expression (N), Typ);
2118 Expr_Type := Etype (Expression (N));
2120 -- If not overloaded, then we know the type, and all that needs doing
2121 -- is to check that this type is compatible with the context.
2123 elsif not Is_Overloaded (N) then
2124 Found := Covers (Typ, Etype (N));
2125 Expr_Type := Etype (N);
2127 -- In the overloaded case, we must select the interpretation that
2128 -- is compatible with the context (i.e. the type passed to Resolve)
2131 -- Loop through possible interpretations
2133 Get_First_Interp (N, I, It);
2134 Interp_Loop : while Present (It.Typ) loop
2135 if Debug_Flag_V then
2136 Write_Str ("Interp: ");
2140 -- We are only interested in interpretations that are compatible
2141 -- with the expected type, any other interpretations are ignored.
2143 if not Covers (Typ, It.Typ) then
2144 if Debug_Flag_V then
2145 Write_Str (" interpretation incompatible with context");
2150 -- Skip the current interpretation if it is disabled by an
2151 -- abstract operator. This action is performed only when the
2152 -- type against which we are resolving is the same as the
2153 -- type of the interpretation.
2155 if Ada_Version >= Ada_2005
2156 and then It.Typ = Typ
2157 and then Typ /= Universal_Integer
2158 and then Typ /= Universal_Real
2159 and then Present (It.Abstract_Op)
2161 if Debug_Flag_V then
2162 Write_Line ("Skip.");
2168 -- First matching interpretation
2174 Expr_Type := It.Typ;
2176 -- Matching interpretation that is not the first, maybe an
2177 -- error, but there are some cases where preference rules are
2178 -- used to choose between the two possibilities. These and
2179 -- some more obscure cases are handled in Disambiguate.
2182 -- If the current statement is part of a predefined library
2183 -- unit, then all interpretations which come from user level
2184 -- packages should not be considered. Check previous and
2188 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2191 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2193 -- Previous interpretation must be discarded
2197 Expr_Type := It.Typ;
2198 Set_Entity (N, Seen);
2203 -- Otherwise apply further disambiguation steps
2205 Error_Msg_Sloc := Sloc (Seen);
2206 It1 := Disambiguate (N, I1, I, Typ);
2208 -- Disambiguation has succeeded. Skip the remaining
2211 if It1 /= No_Interp then
2213 Expr_Type := It1.Typ;
2215 while Present (It.Typ) loop
2216 Get_Next_Interp (I, It);
2220 -- Before we issue an ambiguity complaint, check for the
2221 -- case of a subprogram call where at least one of the
2222 -- arguments is Any_Type, and if so suppress the message,
2223 -- since it is a cascaded error. This can also happen for
2224 -- a generalized indexing operation.
2226 if Nkind (N) in N_Subprogram_Call
2227 or else (Nkind (N) = N_Indexed_Component
2228 and then Present (Generalized_Indexing (N)))
2235 if Nkind (N) = N_Indexed_Component then
2236 Rewrite (N, Generalized_Indexing (N));
2239 A := First_Actual (N);
2240 while Present (A) loop
2243 if Nkind (E) = N_Parameter_Association then
2244 E := Explicit_Actual_Parameter (E);
2247 if Etype (E) = Any_Type then
2248 if Debug_Flag_V then
2249 Write_Str ("Any_Type in call");
2260 elsif Nkind (N) in N_Binary_Op
2261 and then (Etype (Left_Opnd (N)) = Any_Type
2262 or else Etype (Right_Opnd (N)) = Any_Type)
2266 elsif Nkind (N) in N_Unary_Op
2267 and then Etype (Right_Opnd (N)) = Any_Type
2272 -- Not that special case, so issue message using the flag
2273 -- Ambiguous to control printing of the header message
2274 -- only at the start of an ambiguous set.
2276 if not Ambiguous then
2277 if Nkind (N) = N_Function_Call
2278 and then Nkind (Name (N)) = N_Explicit_Dereference
2281 ("ambiguous expression (cannot resolve indirect "
2284 Error_Msg_NE -- CODEFIX
2285 ("ambiguous expression (cannot resolve&)!",
2291 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2293 ("\\possible interpretation (inherited)#!", N);
2295 Error_Msg_N -- CODEFIX
2296 ("\\possible interpretation#!", N);
2299 if Nkind (N) in N_Subprogram_Call
2300 and then Present (Parameter_Associations (N))
2302 Report_Ambiguous_Argument;
2306 Error_Msg_Sloc := Sloc (It.Nam);
2308 -- By default, the error message refers to the candidate
2309 -- interpretation. But if it is a predefined operator, it
2310 -- is implicitly declared at the declaration of the type
2311 -- of the operand. Recover the sloc of that declaration
2312 -- for the error message.
2314 if Nkind (N) in N_Op
2315 and then Scope (It.Nam) = Standard_Standard
2316 and then not Is_Overloaded (Right_Opnd (N))
2317 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2320 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2322 if Comes_From_Source (Err_Type)
2323 and then Present (Parent (Err_Type))
2325 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2328 elsif Nkind (N) in N_Binary_Op
2329 and then Scope (It.Nam) = Standard_Standard
2330 and then not Is_Overloaded (Left_Opnd (N))
2331 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2334 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2336 if Comes_From_Source (Err_Type)
2337 and then Present (Parent (Err_Type))
2339 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2342 -- If this is an indirect call, use the subprogram_type
2343 -- in the message, to have a meaningful location. Also
2344 -- indicate if this is an inherited operation, created
2345 -- by a type declaration.
2347 elsif Nkind (N) = N_Function_Call
2348 and then Nkind (Name (N)) = N_Explicit_Dereference
2349 and then Is_Type (It.Nam)
2353 Sloc (Associated_Node_For_Itype (Err_Type));
2358 if Nkind (N) in N_Op
2359 and then Scope (It.Nam) = Standard_Standard
2360 and then Present (Err_Type)
2362 -- Special-case the message for universal_fixed
2363 -- operators, which are not declared with the type
2364 -- of the operand, but appear forever in Standard.
2366 if It.Typ = Universal_Fixed
2367 and then Scope (It.Nam) = Standard_Standard
2370 ("\\possible interpretation as universal_fixed "
2371 & "operation (RM 4.5.5 (19))", N);
2374 ("\\possible interpretation (predefined)#!", N);
2378 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2381 ("\\possible interpretation (inherited)#!", N);
2383 Error_Msg_N -- CODEFIX
2384 ("\\possible interpretation#!", N);
2390 -- We have a matching interpretation, Expr_Type is the type
2391 -- from this interpretation, and Seen is the entity.
2393 -- For an operator, just set the entity name. The type will be
2394 -- set by the specific operator resolution routine.
2396 if Nkind (N) in N_Op then
2397 Set_Entity (N, Seen);
2398 Generate_Reference (Seen, N);
2400 elsif Nkind_In (N, N_Case_Expression,
2401 N_Character_Literal,
2405 Set_Etype (N, Expr_Type);
2407 -- AI05-0139-2: Expression is overloaded because type has
2408 -- implicit dereference. If type matches context, no implicit
2409 -- dereference is involved. If the expression is an entity,
2410 -- generate a reference to it, as this is not done for an
2411 -- overloaded construct during analysis.
2413 elsif Has_Implicit_Dereference (Expr_Type) then
2414 Set_Etype (N, Expr_Type);
2415 Set_Is_Overloaded (N, False);
2417 if Is_Entity_Name (N) then
2418 Generate_Reference (Entity (N), N);
2423 elsif Is_Overloaded (N)
2424 and then Present (It.Nam)
2425 and then Ekind (It.Nam) = E_Discriminant
2426 and then Has_Implicit_Dereference (It.Nam)
2428 -- If the node is a general indexing, the dereference is
2429 -- is inserted when resolving the rewritten form, else
2432 if Nkind (N) /= N_Indexed_Component
2433 or else No (Generalized_Indexing (N))
2435 Build_Explicit_Dereference (N, It.Nam);
2438 -- For an explicit dereference, attribute reference, range,
2439 -- short-circuit form (which is not an operator node), or call
2440 -- with a name that is an explicit dereference, there is
2441 -- nothing to be done at this point.
2443 elsif Nkind_In (N, N_Attribute_Reference,
2445 N_Explicit_Dereference,
2447 N_Indexed_Component,
2450 N_Selected_Component,
2452 or else Nkind (Name (N)) = N_Explicit_Dereference
2456 -- For procedure or function calls, set the type of the name,
2457 -- and also the entity pointer for the prefix.
2459 elsif Nkind (N) in N_Subprogram_Call
2460 and then Is_Entity_Name (Name (N))
2462 Set_Etype (Name (N), Expr_Type);
2463 Set_Entity (Name (N), Seen);
2464 Generate_Reference (Seen, Name (N));
2466 elsif Nkind (N) = N_Function_Call
2467 and then Nkind (Name (N)) = N_Selected_Component
2469 Set_Etype (Name (N), Expr_Type);
2470 Set_Entity (Selector_Name (Name (N)), Seen);
2471 Generate_Reference (Seen, Selector_Name (Name (N)));
2473 -- For all other cases, just set the type of the Name
2476 Set_Etype (Name (N), Expr_Type);
2483 -- Move to next interpretation
2485 exit Interp_Loop when No (It.Typ);
2487 Get_Next_Interp (I, It);
2488 end loop Interp_Loop;
2491 -- At this stage Found indicates whether or not an acceptable
2492 -- interpretation exists. If not, then we have an error, except that if
2493 -- the context is Any_Type as a result of some other error, then we
2494 -- suppress the error report.
2497 if Typ /= Any_Type then
2499 -- If type we are looking for is Void, then this is the procedure
2500 -- call case, and the error is simply that what we gave is not a
2501 -- procedure name (we think of procedure calls as expressions with
2502 -- types internally, but the user doesn't think of them this way).
2504 if Typ = Standard_Void_Type then
2506 -- Special case message if function used as a procedure
2508 if Nkind (N) = N_Procedure_Call_Statement
2509 and then Is_Entity_Name (Name (N))
2510 and then Ekind (Entity (Name (N))) = E_Function
2513 ("cannot use call to function & as a statement",
2514 Name (N), Entity (Name (N)));
2516 ("\return value of a function call cannot be ignored",
2519 -- Otherwise give general message (not clear what cases this
2520 -- covers, but no harm in providing for them).
2523 Error_Msg_N ("expect procedure name in procedure call", N);
2528 -- Otherwise we do have a subexpression with the wrong type
2530 -- Check for the case of an allocator which uses an access type
2531 -- instead of the designated type. This is a common error and we
2532 -- specialize the message, posting an error on the operand of the
2533 -- allocator, complaining that we expected the designated type of
2536 elsif Nkind (N) = N_Allocator
2537 and then Is_Access_Type (Typ)
2538 and then Is_Access_Type (Etype (N))
2539 and then Designated_Type (Etype (N)) = Typ
2541 Wrong_Type (Expression (N), Designated_Type (Typ));
2544 -- Check for view mismatch on Null in instances, for which the
2545 -- view-swapping mechanism has no identifier.
2547 elsif (In_Instance or else In_Inlined_Body)
2548 and then (Nkind (N) = N_Null)
2549 and then Is_Private_Type (Typ)
2550 and then Is_Access_Type (Full_View (Typ))
2552 Resolve (N, Full_View (Typ));
2556 -- Check for an aggregate. Sometimes we can get bogus aggregates
2557 -- from misuse of parentheses, and we are about to complain about
2558 -- the aggregate without even looking inside it.
2560 -- Instead, if we have an aggregate of type Any_Composite, then
2561 -- analyze and resolve the component fields, and then only issue
2562 -- another message if we get no errors doing this (otherwise
2563 -- assume that the errors in the aggregate caused the problem).
2565 elsif Nkind (N) = N_Aggregate
2566 and then Etype (N) = Any_Composite
2568 -- Disable expansion in any case. If there is a type mismatch
2569 -- it may be fatal to try to expand the aggregate. The flag
2570 -- would otherwise be set to false when the error is posted.
2572 Expander_Active := False;
2575 procedure Check_Aggr (Aggr : Node_Id);
2576 -- Check one aggregate, and set Found to True if we have a
2577 -- definite error in any of its elements
2579 procedure Check_Elmt (Aelmt : Node_Id);
2580 -- Check one element of aggregate and set Found to True if
2581 -- we definitely have an error in the element.
2587 procedure Check_Aggr (Aggr : Node_Id) is
2591 if Present (Expressions (Aggr)) then
2592 Elmt := First (Expressions (Aggr));
2593 while Present (Elmt) loop
2599 if Present (Component_Associations (Aggr)) then
2600 Elmt := First (Component_Associations (Aggr));
2601 while Present (Elmt) loop
2603 -- If this is a default-initialized component, then
2604 -- there is nothing to check. The box will be
2605 -- replaced by the appropriate call during late
2608 if Nkind (Elmt) /= N_Iterated_Component_Association
2609 and then not Box_Present (Elmt)
2611 Check_Elmt (Expression (Elmt));
2623 procedure Check_Elmt (Aelmt : Node_Id) is
2625 -- If we have a nested aggregate, go inside it (to
2626 -- attempt a naked analyze-resolve of the aggregate can
2627 -- cause undesirable cascaded errors). Do not resolve
2628 -- expression if it needs a type from context, as for
2629 -- integer * fixed expression.
2631 if Nkind (Aelmt) = N_Aggregate then
2637 if not Is_Overloaded (Aelmt)
2638 and then Etype (Aelmt) /= Any_Fixed
2643 if Etype (Aelmt) = Any_Type then
2654 -- Looks like we have a type error, but check for special case
2655 -- of Address wanted, integer found, with the configuration pragma
2656 -- Allow_Integer_Address active. If we have this case, introduce
2657 -- an unchecked conversion to allow the integer expression to be
2658 -- treated as an Address. The reverse case of integer wanted,
2659 -- Address found, is treated in an analogous manner.
2661 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2662 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2663 Analyze_And_Resolve (N, Typ);
2666 -- Under relaxed RM semantics silently replace occurrences of null
2667 -- by System.Address_Null.
2669 elsif Null_To_Null_Address_Convert_OK (N, Typ) then
2670 Replace_Null_By_Null_Address (N);
2671 Analyze_And_Resolve (N, Typ);
2675 -- That special Allow_Integer_Address check did not apply, so we
2676 -- have a real type error. If an error message was issued already,
2677 -- Found got reset to True, so if it's still False, issue standard
2678 -- Wrong_Type message.
2681 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2683 Subp_Name : Node_Id;
2686 if Is_Entity_Name (Name (N)) then
2687 Subp_Name := Name (N);
2689 elsif Nkind (Name (N)) = N_Selected_Component then
2691 -- Protected operation: retrieve operation name
2693 Subp_Name := Selector_Name (Name (N));
2696 raise Program_Error;
2699 Error_Msg_Node_2 := Typ;
2701 ("no visible interpretation of& matches expected type&",
2705 if All_Errors_Mode then
2707 Index : Interp_Index;
2711 Error_Msg_N ("\\possible interpretations:", N);
2713 Get_First_Interp (Name (N), Index, It);
2714 while Present (It.Nam) loop
2715 Error_Msg_Sloc := Sloc (It.Nam);
2716 Error_Msg_Node_2 := It.Nam;
2718 ("\\ type& for & declared#", N, It.Typ);
2719 Get_Next_Interp (Index, It);
2724 Error_Msg_N ("\use -gnatf for details", N);
2728 Wrong_Type (N, Typ);
2736 -- Test if we have more than one interpretation for the context
2738 elsif Ambiguous then
2742 -- Only one intepretation
2745 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2746 -- the "+" on T is abstract, and the operands are of universal type,
2747 -- the above code will have (incorrectly) resolved the "+" to the
2748 -- universal one in Standard. Therefore check for this case and give
2749 -- an error. We can't do this earlier, because it would cause legal
2750 -- cases to get errors (when some other type has an abstract "+").
2752 if Ada_Version >= Ada_2005
2753 and then Nkind (N) in N_Op
2754 and then Is_Overloaded (N)
2755 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2757 Get_First_Interp (N, I, It);
2758 while Present (It.Typ) loop
2759 if Present (It.Abstract_Op) and then
2760 Etype (It.Abstract_Op) = Typ
2763 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2767 Get_Next_Interp (I, It);
2771 -- Here we have an acceptable interpretation for the context
2773 -- Propagate type information and normalize tree for various
2774 -- predefined operations. If the context only imposes a class of
2775 -- types, rather than a specific type, propagate the actual type
2778 if Typ = Any_Integer or else
2779 Typ = Any_Boolean or else
2780 Typ = Any_Modular or else
2781 Typ = Any_Real or else
2784 Ctx_Type := Expr_Type;
2786 -- Any_Fixed is legal in a real context only if a specific fixed-
2787 -- point type is imposed. If Norman Cohen can be confused by this,
2788 -- it deserves a separate message.
2791 and then Expr_Type = Any_Fixed
2793 Error_Msg_N ("illegal context for mixed mode operation", N);
2794 Set_Etype (N, Universal_Real);
2795 Ctx_Type := Universal_Real;
2799 -- A user-defined operator is transformed into a function call at
2800 -- this point, so that further processing knows that operators are
2801 -- really operators (i.e. are predefined operators). User-defined
2802 -- operators that are intrinsic are just renamings of the predefined
2803 -- ones, and need not be turned into calls either, but if they rename
2804 -- a different operator, we must transform the node accordingly.
2805 -- Instantiations of Unchecked_Conversion are intrinsic but are
2806 -- treated as functions, even if given an operator designator.
2808 if Nkind (N) in N_Op
2809 and then Present (Entity (N))
2810 and then Ekind (Entity (N)) /= E_Operator
2812 if not Is_Predefined_Op (Entity (N)) then
2813 Rewrite_Operator_As_Call (N, Entity (N));
2815 elsif Present (Alias (Entity (N)))
2817 Nkind (Parent (Parent (Entity (N)))) =
2818 N_Subprogram_Renaming_Declaration
2820 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2822 -- If the node is rewritten, it will be fully resolved in
2823 -- Rewrite_Renamed_Operator.
2825 if Analyzed (N) then
2831 case N_Subexpr'(Nkind (N)) is
2833 Resolve_Aggregate (N, Ctx_Type);
2836 Resolve_Allocator (N, Ctx_Type);
2838 when N_Short_Circuit =>
2839 Resolve_Short_Circuit (N, Ctx_Type);
2841 when N_Attribute_Reference =>
2842 Resolve_Attribute (N, Ctx_Type);
2844 when N_Case_Expression =>
2845 Resolve_Case_Expression (N, Ctx_Type);
2847 when N_Character_Literal =>
2848 Resolve_Character_Literal (N, Ctx_Type);
2850 when N_Delta_Aggregate =>
2851 Resolve_Delta_Aggregate (N, Ctx_Type);
2853 when N_Expanded_Name =>
2854 Resolve_Entity_Name (N, Ctx_Type);
2856 when N_Explicit_Dereference =>
2857 Resolve_Explicit_Dereference (N, Ctx_Type);
2859 when N_Expression_With_Actions =>
2860 Resolve_Expression_With_Actions (N, Ctx_Type);
2862 when N_Extension_Aggregate =>
2863 Resolve_Extension_Aggregate (N, Ctx_Type);
2865 when N_Function_Call =>
2866 Resolve_Call (N, Ctx_Type);
2868 when N_Identifier =>
2869 Resolve_Entity_Name (N, Ctx_Type);
2871 when N_If_Expression =>
2872 Resolve_If_Expression (N, Ctx_Type);
2874 when N_Indexed_Component =>
2875 Resolve_Indexed_Component (N, Ctx_Type);
2877 when N_Integer_Literal =>
2878 Resolve_Integer_Literal (N, Ctx_Type);
2880 when N_Membership_Test =>
2881 Resolve_Membership_Op (N, Ctx_Type);
2884 Resolve_Null (N, Ctx_Type);
2890 Resolve_Logical_Op (N, Ctx_Type);
2895 Resolve_Equality_Op (N, Ctx_Type);
2902 Resolve_Comparison_Op (N, Ctx_Type);
2905 Resolve_Op_Not (N, Ctx_Type);
2914 Resolve_Arithmetic_Op (N, Ctx_Type);
2917 Resolve_Op_Concat (N, Ctx_Type);
2920 Resolve_Op_Expon (N, Ctx_Type);
2926 Resolve_Unary_Op (N, Ctx_Type);
2929 Resolve_Shift (N, Ctx_Type);
2931 when N_Procedure_Call_Statement =>
2932 Resolve_Call (N, Ctx_Type);
2934 when N_Operator_Symbol =>
2935 Resolve_Operator_Symbol (N, Ctx_Type);
2937 when N_Qualified_Expression =>
2938 Resolve_Qualified_Expression (N, Ctx_Type);
2940 -- Why is the following null, needs a comment ???
2942 when N_Quantified_Expression =>
2945 when N_Raise_Expression =>
2946 Resolve_Raise_Expression (N, Ctx_Type);
2948 when N_Raise_xxx_Error =>
2949 Set_Etype (N, Ctx_Type);
2952 Resolve_Range (N, Ctx_Type);
2954 when N_Real_Literal =>
2955 Resolve_Real_Literal (N, Ctx_Type);
2958 Resolve_Reference (N, Ctx_Type);
2960 when N_Selected_Component =>
2961 Resolve_Selected_Component (N, Ctx_Type);
2964 Resolve_Slice (N, Ctx_Type);
2966 when N_String_Literal =>
2967 Resolve_String_Literal (N, Ctx_Type);
2969 when N_Target_Name =>
2970 Resolve_Target_Name (N, Ctx_Type);
2972 when N_Type_Conversion =>
2973 Resolve_Type_Conversion (N, Ctx_Type);
2975 when N_Unchecked_Expression =>
2976 Resolve_Unchecked_Expression (N, Ctx_Type);
2978 when N_Unchecked_Type_Conversion =>
2979 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2982 -- Mark relevant use-type and use-package clauses as effective using
2983 -- the original node because constant folding may have occured and
2984 -- removed references that need to be examined.
2986 if Nkind (Original_Node (N)) in N_Op then
2987 Mark_Use_Clauses (Original_Node (N));
2990 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2991 -- expression of an anonymous access type that occurs in the context
2992 -- of a named general access type, except when the expression is that
2993 -- of a membership test. This ensures proper legality checking in
2994 -- terms of allowed conversions (expressions that would be illegal to
2995 -- convert implicitly are allowed in membership tests).
2997 if Ada_Version >= Ada_2012
2998 and then Ekind (Ctx_Type) = E_General_Access_Type
2999 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3000 and then Nkind (Parent (N)) not in N_Membership_Test
3002 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3003 Analyze_And_Resolve (N, Ctx_Type);
3006 -- If the subexpression was replaced by a non-subexpression, then
3007 -- all we do is to expand it. The only legitimate case we know of
3008 -- is converting procedure call statement to entry call statements,
3009 -- but there may be others, so we are making this test general.
3011 if Nkind (N) not in N_Subexpr then
3012 Debug_A_Exit ("resolving ", N, " (done)");
3017 -- The expression is definitely NOT overloaded at this point, so
3018 -- we reset the Is_Overloaded flag to avoid any confusion when
3019 -- reanalyzing the node.
3021 Set_Is_Overloaded (N, False);
3023 -- Freeze expression type, entity if it is a name, and designated
3024 -- type if it is an allocator (RM 13.14(10,11,13)).
3026 -- Now that the resolution of the type of the node is complete, and
3027 -- we did not detect an error, we can expand this node. We skip the
3028 -- expand call if we are in a default expression, see section
3029 -- "Handling of Default Expressions" in Sem spec.
3031 Debug_A_Exit ("resolving ", N, " (done)");
3033 -- We unconditionally freeze the expression, even if we are in
3034 -- default expression mode (the Freeze_Expression routine tests this
3035 -- flag and only freezes static types if it is set).
3037 -- Ada 2012 (AI05-177): The declaration of an expression function
3038 -- does not cause freezing, but we never reach here in that case.
3039 -- Here we are resolving the corresponding expanded body, so we do
3040 -- need to perform normal freezing.
3042 -- As elsewhere we do not emit freeze node within a generic. We make
3043 -- an exception for entities that are expressions, only to detect
3044 -- misuses of deferred constants and preserve the output of various
3047 if not Inside_A_Generic or else Is_Entity_Name (N) then
3048 Freeze_Expression (N);
3051 -- Now we can do the expansion
3061 -- Version with check(s) suppressed
3063 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3065 if Suppress = All_Checks then
3067 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3069 Scope_Suppress.Suppress := (others => True);
3071 Scope_Suppress.Suppress := Sva;
3076 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3078 Scope_Suppress.Suppress (Suppress) := True;
3080 Scope_Suppress.Suppress (Suppress) := Svg;
3089 -- Version with implicit type
3091 procedure Resolve (N : Node_Id) is
3093 Resolve (N, Etype (N));
3096 ---------------------
3097 -- Resolve_Actuals --
3098 ---------------------
3100 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3101 Loc : constant Source_Ptr := Sloc (N);
3104 A_Typ : Entity_Id := Empty; -- init to avoid warning
3107 Prev : Node_Id := Empty;
3109 Real_F : Entity_Id := Empty; -- init to avoid warning
3111 Real_Subp : Entity_Id;
3112 -- If the subprogram being called is an inherited operation for
3113 -- a formal derived type in an instance, Real_Subp is the subprogram
3114 -- that will be called. It may have different formal names than the
3115 -- operation of the formal in the generic, so after actual is resolved
3116 -- the name of the actual in a named association must carry the name
3117 -- of the actual of the subprogram being called.
3119 procedure Check_Aliased_Parameter;
3120 -- Check rules on aliased parameters and related accessibility rules
3121 -- in (RM 3.10.2 (10.2-10.4)).
3123 procedure Check_Argument_Order;
3124 -- Performs a check for the case where the actuals are all simple
3125 -- identifiers that correspond to the formal names, but in the wrong
3126 -- order, which is considered suspicious and cause for a warning.
3128 procedure Check_Prefixed_Call;
3129 -- If the original node is an overloaded call in prefix notation,
3130 -- insert an 'Access or a dereference as needed over the first actual.
3131 -- Try_Object_Operation has already verified that there is a valid
3132 -- interpretation, but the form of the actual can only be determined
3133 -- once the primitive operation is identified.
3135 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id);
3136 -- Emit an error concerning the illegal usage of an effectively volatile
3137 -- object in interfering context (SPARK RM 7.13(12)).
3139 procedure Insert_Default;
3140 -- If the actual is missing in a call, insert in the actuals list
3141 -- an instance of the default expression. The insertion is always
3142 -- a named association.
3144 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3145 -- Check whether T1 and T2, or their full views, are derived from a
3146 -- common type. Used to enforce the restrictions on array conversions
3149 function Static_Concatenation (N : Node_Id) return Boolean;
3150 -- Predicate to determine whether an actual that is a concatenation
3151 -- will be evaluated statically and does not need a transient scope.
3152 -- This must be determined before the actual is resolved and expanded
3153 -- because if needed the transient scope must be introduced earlier.
3155 -----------------------------
3156 -- Check_Aliased_Parameter --
3157 -----------------------------
3159 procedure Check_Aliased_Parameter is
3160 Nominal_Subt : Entity_Id;
3163 if Is_Aliased (F) then
3164 if Is_Tagged_Type (A_Typ) then
3167 elsif Is_Aliased_View (A) then
3168 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3169 Nominal_Subt := Base_Type (A_Typ);
3171 Nominal_Subt := A_Typ;
3174 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3177 -- In a generic body assume the worst for generic formals:
3178 -- they can have a constrained partial view (AI05-041).
3180 elsif Has_Discriminants (F_Typ)
3181 and then not Is_Constrained (F_Typ)
3182 and then not Has_Constrained_Partial_View (F_Typ)
3183 and then not Is_Generic_Type (F_Typ)
3188 Error_Msg_NE ("untagged actual does not match "
3189 & "aliased formal&", A, F);
3193 Error_Msg_NE ("actual for aliased formal& must be "
3194 & "aliased object", A, F);
3197 if Ekind (Nam) = E_Procedure then
3200 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3201 if Nkind (Parent (N)) = N_Type_Conversion
3202 and then Type_Access_Level (Etype (Parent (N))) <
3203 Object_Access_Level (A)
3205 Error_Msg_N ("aliased actual has wrong accessibility", A);
3208 elsif Nkind (Parent (N)) = N_Qualified_Expression
3209 and then Nkind (Parent (Parent (N))) = N_Allocator
3210 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3211 Object_Access_Level (A)
3214 ("aliased actual in allocator has wrong accessibility", A);
3217 end Check_Aliased_Parameter;
3219 --------------------------
3220 -- Check_Argument_Order --
3221 --------------------------
3223 procedure Check_Argument_Order is
3225 -- Nothing to do if no parameters, or original node is neither a
3226 -- function call nor a procedure call statement (happens in the
3227 -- operator-transformed-to-function call case), or the call does
3228 -- not come from source, or this warning is off.
3230 if not Warn_On_Parameter_Order
3231 or else No (Parameter_Associations (N))
3232 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3233 or else not Comes_From_Source (N)
3239 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3242 -- Nothing to do if only one parameter
3248 -- Here if at least two arguments
3251 Actuals : array (1 .. Nargs) of Node_Id;
3255 Wrong_Order : Boolean := False;
3256 -- Set True if an out of order case is found
3259 -- Collect identifier names of actuals, fail if any actual is
3260 -- not a simple identifier, and record max length of name.
3262 Actual := First (Parameter_Associations (N));
3263 for J in Actuals'Range loop
3264 if Nkind (Actual) /= N_Identifier then
3267 Actuals (J) := Actual;
3272 -- If we got this far, all actuals are identifiers and the list
3273 -- of their names is stored in the Actuals array.
3275 Formal := First_Formal (Nam);
3276 for J in Actuals'Range loop
3278 -- If we ran out of formals, that's odd, probably an error
3279 -- which will be detected elsewhere, but abandon the search.
3285 -- If name matches and is in order OK
3287 if Chars (Formal) = Chars (Actuals (J)) then
3291 -- If no match, see if it is elsewhere in list and if so
3292 -- flag potential wrong order if type is compatible.
3294 for K in Actuals'Range loop
3295 if Chars (Formal) = Chars (Actuals (K))
3297 Has_Compatible_Type (Actuals (K), Etype (Formal))
3299 Wrong_Order := True;
3309 <<Continue>> Next_Formal (Formal);
3312 -- If Formals left over, also probably an error, skip warning
3314 if Present (Formal) then
3318 -- Here we give the warning if something was out of order
3322 ("?P?actuals for this call may be in wrong order", N);
3326 end Check_Argument_Order;
3328 -------------------------
3329 -- Check_Prefixed_Call --
3330 -------------------------
3332 procedure Check_Prefixed_Call is
3333 Act : constant Node_Id := First_Actual (N);
3334 A_Type : constant Entity_Id := Etype (Act);
3335 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3336 Orig : constant Node_Id := Original_Node (N);
3340 -- Check whether the call is a prefixed call, with or without
3341 -- additional actuals.
3343 if Nkind (Orig) = N_Selected_Component
3345 (Nkind (Orig) = N_Indexed_Component
3346 and then Nkind (Prefix (Orig)) = N_Selected_Component
3347 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3348 and then Is_Entity_Name (Act)
3349 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3351 if Is_Access_Type (A_Type)
3352 and then not Is_Access_Type (F_Type)
3354 -- Introduce dereference on object in prefix
3357 Make_Explicit_Dereference (Sloc (Act),
3358 Prefix => Relocate_Node (Act));
3359 Rewrite (Act, New_A);
3362 elsif Is_Access_Type (F_Type)
3363 and then not Is_Access_Type (A_Type)
3365 -- Introduce an implicit 'Access in prefix
3367 if not Is_Aliased_View (Act) then
3369 ("object in prefixed call to& must be aliased "
3370 & "(RM 4.1.3 (13 1/2))",
3375 Make_Attribute_Reference (Loc,
3376 Attribute_Name => Name_Access,
3377 Prefix => Relocate_Node (Act)));
3382 end Check_Prefixed_Call;
3384 ---------------------------------------
3385 -- Flag_Effectively_Volatile_Objects --
3386 ---------------------------------------
3388 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id) is
3389 function Flag_Object (N : Node_Id) return Traverse_Result;
3390 -- Determine whether arbitrary node N denotes an effectively volatile
3391 -- object and if it does, emit an error.
3397 function Flag_Object (N : Node_Id) return Traverse_Result is
3401 -- Do not consider nested function calls because they have already
3402 -- been processed during their own resolution.
3404 if Nkind (N) = N_Function_Call then
3407 elsif Is_Entity_Name (N) and then Present (Entity (N)) then
3411 and then Is_Effectively_Volatile (Id)
3412 and then (Async_Writers_Enabled (Id)
3413 or else Effective_Reads_Enabled (Id))
3416 ("volatile object cannot appear in this context (SPARK "
3417 & "RM 7.1.3(11))", N);
3425 procedure Flag_Objects is new Traverse_Proc (Flag_Object);
3427 -- Start of processing for Flag_Effectively_Volatile_Objects
3430 Flag_Objects (Expr);
3431 end Flag_Effectively_Volatile_Objects;
3433 --------------------
3434 -- Insert_Default --
3435 --------------------
3437 procedure Insert_Default is
3442 -- Missing argument in call, nothing to insert
3444 if No (Default_Value (F)) then
3448 -- Note that we do a full New_Copy_Tree, so that any associated
3449 -- Itypes are properly copied. This may not be needed any more,
3450 -- but it does no harm as a safety measure. Defaults of a generic
3451 -- formal may be out of bounds of the corresponding actual (see
3452 -- cc1311b) and an additional check may be required.
3457 New_Scope => Current_Scope,
3460 -- Propagate dimension information, if any.
3462 Copy_Dimensions (Default_Value (F), Actval);
3464 if Is_Concurrent_Type (Scope (Nam))
3465 and then Has_Discriminants (Scope (Nam))
3467 Replace_Actual_Discriminants (N, Actval);
3470 if Is_Overloadable (Nam)
3471 and then Present (Alias (Nam))
3473 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3474 and then not Is_Tagged_Type (Etype (F))
3476 -- If default is a real literal, do not introduce a
3477 -- conversion whose effect may depend on the run-time
3478 -- size of universal real.
3480 if Nkind (Actval) = N_Real_Literal then
3481 Set_Etype (Actval, Base_Type (Etype (F)));
3483 Actval := Unchecked_Convert_To (Etype (F), Actval);
3487 if Is_Scalar_Type (Etype (F)) then
3488 Enable_Range_Check (Actval);
3491 Set_Parent (Actval, N);
3493 -- Resolve aggregates with their base type, to avoid scope
3494 -- anomalies: the subtype was first built in the subprogram
3495 -- declaration, and the current call may be nested.
3497 if Nkind (Actval) = N_Aggregate then
3498 Analyze_And_Resolve (Actval, Etype (F));
3500 Analyze_And_Resolve (Actval, Etype (Actval));
3504 Set_Parent (Actval, N);
3506 -- See note above concerning aggregates
3508 if Nkind (Actval) = N_Aggregate
3509 and then Has_Discriminants (Etype (Actval))
3511 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3513 -- Resolve entities with their own type, which may differ from
3514 -- the type of a reference in a generic context (the view
3515 -- swapping mechanism did not anticipate the re-analysis of
3516 -- default values in calls).
3518 elsif Is_Entity_Name (Actval) then
3519 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3522 Analyze_And_Resolve (Actval, Etype (Actval));
3526 -- If default is a tag indeterminate function call, propagate tag
3527 -- to obtain proper dispatching.
3529 if Is_Controlling_Formal (F)
3530 and then Nkind (Default_Value (F)) = N_Function_Call
3532 Set_Is_Controlling_Actual (Actval);
3536 -- If the default expression raises constraint error, then just
3537 -- silently replace it with an N_Raise_Constraint_Error node, since
3538 -- we already gave the warning on the subprogram spec. If node is
3539 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3540 -- the warnings removal machinery.
3542 if Raises_Constraint_Error (Actval)
3543 and then Nkind (Actval) /= N_Raise_Constraint_Error
3546 Make_Raise_Constraint_Error (Loc,
3547 Reason => CE_Range_Check_Failed));
3549 Set_Raises_Constraint_Error (Actval);
3550 Set_Etype (Actval, Etype (F));
3554 Make_Parameter_Association (Loc,
3555 Explicit_Actual_Parameter => Actval,
3556 Selector_Name => Make_Identifier (Loc, Chars (F)));
3558 -- Case of insertion is first named actual
3561 or else Nkind (Parent (Prev)) /= N_Parameter_Association
3563 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3564 Set_First_Named_Actual (N, Actval);
3567 if No (Parameter_Associations (N)) then
3568 Set_Parameter_Associations (N, New_List (Assoc));
3570 Append (Assoc, Parameter_Associations (N));
3574 Insert_After (Prev, Assoc);
3577 -- Case of insertion is not first named actual
3580 Set_Next_Named_Actual
3581 (Assoc, Next_Named_Actual (Parent (Prev)));
3582 Set_Next_Named_Actual (Parent (Prev), Actval);
3583 Append (Assoc, Parameter_Associations (N));
3586 Mark_Rewrite_Insertion (Assoc);
3587 Mark_Rewrite_Insertion (Actval);
3596 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3597 FT1 : Entity_Id := T1;
3598 FT2 : Entity_Id := T2;
3601 if Is_Private_Type (T1)
3602 and then Present (Full_View (T1))
3604 FT1 := Full_View (T1);
3607 if Is_Private_Type (T2)
3608 and then Present (Full_View (T2))
3610 FT2 := Full_View (T2);
3613 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3616 --------------------------
3617 -- Static_Concatenation --
3618 --------------------------
3620 function Static_Concatenation (N : Node_Id) return Boolean is
3623 when N_String_Literal =>
3628 -- Concatenation is static when both operands are static and
3629 -- the concatenation operator is a predefined one.
3631 return Scope (Entity (N)) = Standard_Standard
3633 Static_Concatenation (Left_Opnd (N))
3635 Static_Concatenation (Right_Opnd (N));
3638 if Is_Entity_Name (N) then
3640 Ent : constant Entity_Id := Entity (N);
3642 return Ekind (Ent) = E_Constant
3643 and then Present (Constant_Value (Ent))
3645 Is_OK_Static_Expression (Constant_Value (Ent));
3652 end Static_Concatenation;
3654 -- Start of processing for Resolve_Actuals
3657 Check_Argument_Order;
3659 if Is_Overloadable (Nam)
3660 and then Is_Inherited_Operation (Nam)
3661 and then In_Instance
3662 and then Present (Alias (Nam))
3663 and then Present (Overridden_Operation (Alias (Nam)))
3665 Real_Subp := Alias (Nam);
3670 if Present (First_Actual (N)) then
3671 Check_Prefixed_Call;
3674 A := First_Actual (N);
3675 F := First_Formal (Nam);
3677 if Present (Real_Subp) then
3678 Real_F := First_Formal (Real_Subp);
3681 while Present (F) loop
3682 if No (A) and then Needs_No_Actuals (Nam) then
3685 -- If we have an error in any actual or formal, indicated by a type
3686 -- of Any_Type, then abandon resolution attempt, and set result type
3687 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3688 -- type is imposed from context.
3690 elsif (Present (A) and then Etype (A) = Any_Type)
3691 or else Etype (F) = Any_Type
3693 if Nkind (A) /= N_Raise_Expression then
3694 Set_Etype (N, Any_Type);
3699 -- Case where actual is present
3701 -- If the actual is an entity, generate a reference to it now. We
3702 -- do this before the actual is resolved, because a formal of some
3703 -- protected subprogram, or a task discriminant, will be rewritten
3704 -- during expansion, and the source entity reference may be lost.
3707 and then Is_Entity_Name (A)
3708 and then Comes_From_Source (A)
3710 -- Annotate the tree by creating a variable reference marker when
3711 -- the actual denotes a variable reference, in case the reference
3712 -- is folded or optimized away. The variable reference marker is
3713 -- automatically saved for later examination by the ABE Processing
3714 -- phase. The status of the reference is set as follows:
3718 -- write IN OUT, OUT
3720 if Needs_Variable_Reference_Marker
3724 Build_Variable_Reference_Marker
3726 Read => Ekind (F) /= E_Out_Parameter,
3727 Write => Ekind (F) /= E_In_Parameter);
3730 Orig_A := Entity (A);
3732 if Present (Orig_A) then
3733 if Is_Formal (Orig_A)
3734 and then Ekind (F) /= E_In_Parameter
3736 Generate_Reference (Orig_A, A, 'm');
3738 elsif not Is_Overloaded (A) then
3739 if Ekind (F) /= E_Out_Parameter then
3740 Generate_Reference (Orig_A, A);
3742 -- RM 6.4.1(12): For an out parameter that is passed by
3743 -- copy, the formal parameter object is created, and:
3745 -- * For an access type, the formal parameter is initialized
3746 -- from the value of the actual, without checking that the
3747 -- value satisfies any constraint, any predicate, or any
3748 -- exclusion of the null value.
3750 -- * For a scalar type that has the Default_Value aspect
3751 -- specified, the formal parameter is initialized from the
3752 -- value of the actual, without checking that the value
3753 -- satisfies any constraint or any predicate.
3754 -- I do not understand why this case is included??? this is
3755 -- not a case where an OUT parameter is treated as IN OUT.
3757 -- * For a composite type with discriminants or that has
3758 -- implicit initial values for any subcomponents, the
3759 -- behavior is as for an in out parameter passed by copy.
3761 -- Hence for these cases we generate the read reference now
3762 -- (the write reference will be generated later by
3763 -- Note_Possible_Modification).
3765 elsif Is_By_Copy_Type (Etype (F))
3767 (Is_Access_Type (Etype (F))
3769 (Is_Scalar_Type (Etype (F))
3771 Present (Default_Aspect_Value (Etype (F))))
3773 (Is_Composite_Type (Etype (F))
3774 and then (Has_Discriminants (Etype (F))
3775 or else Is_Partially_Initialized_Type
3778 Generate_Reference (Orig_A, A);
3785 and then (Nkind (Parent (A)) /= N_Parameter_Association
3786 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3788 -- If style checking mode on, check match of formal name
3791 if Nkind (Parent (A)) = N_Parameter_Association then
3792 Check_Identifier (Selector_Name (Parent (A)), F);
3796 -- If the formal is Out or In_Out, do not resolve and expand the
3797 -- conversion, because it is subsequently expanded into explicit
3798 -- temporaries and assignments. However, the object of the
3799 -- conversion can be resolved. An exception is the case of tagged
3800 -- type conversion with a class-wide actual. In that case we want
3801 -- the tag check to occur and no temporary will be needed (no
3802 -- representation change can occur) and the parameter is passed by
3803 -- reference, so we go ahead and resolve the type conversion.
3804 -- Another exception is the case of reference to component or
3805 -- subcomponent of a bit-packed array, in which case we want to
3806 -- defer expansion to the point the in and out assignments are
3809 if Ekind (F) /= E_In_Parameter
3810 and then Nkind (A) = N_Type_Conversion
3811 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3813 if Ekind (F) = E_In_Out_Parameter
3814 and then Is_Array_Type (Etype (F))
3816 -- In a view conversion, the conversion must be legal in
3817 -- both directions, and thus both component types must be
3818 -- aliased, or neither (4.6 (8)).
3820 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3821 -- the privacy requirement should not apply to generic
3822 -- types, and should be checked in an instance. ARG query
3825 if Has_Aliased_Components (Etype (Expression (A))) /=
3826 Has_Aliased_Components (Etype (F))
3829 ("both component types in a view conversion must be"
3830 & " aliased, or neither", A);
3832 -- Comment here??? what set of cases???
3835 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3837 -- Check view conv between unrelated by ref array types
3839 if Is_By_Reference_Type (Etype (F))
3840 or else Is_By_Reference_Type (Etype (Expression (A)))
3843 ("view conversion between unrelated by reference "
3844 & "array types not allowed (\'A'I-00246)", A);
3846 -- In Ada 2005 mode, check view conversion component
3847 -- type cannot be private, tagged, or volatile. Note
3848 -- that we only apply this to source conversions. The
3849 -- generated code can contain conversions which are
3850 -- not subject to this test, and we cannot extract the
3851 -- component type in such cases since it is not present.
3853 elsif Comes_From_Source (A)
3854 and then Ada_Version >= Ada_2005
3857 Comp_Type : constant Entity_Id :=
3859 (Etype (Expression (A)));
3861 if (Is_Private_Type (Comp_Type)
3862 and then not Is_Generic_Type (Comp_Type))
3863 or else Is_Tagged_Type (Comp_Type)
3864 or else Is_Volatile (Comp_Type)
3867 ("component type of a view conversion cannot"
3868 & " be private, tagged, or volatile"
3877 -- Resolve expression if conversion is all OK
3879 if (Conversion_OK (A)
3880 or else Valid_Conversion (A, Etype (A), Expression (A)))
3881 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3883 Resolve (Expression (A));
3886 -- If the actual is a function call that returns a limited
3887 -- unconstrained object that needs finalization, create a
3888 -- transient scope for it, so that it can receive the proper
3889 -- finalization list.
3891 elsif Expander_Active
3892 and then Nkind (A) = N_Function_Call
3893 and then Is_Limited_Record (Etype (F))
3894 and then not Is_Constrained (Etype (F))
3895 and then (Needs_Finalization (Etype (F))
3896 or else Has_Task (Etype (F)))
3898 Establish_Transient_Scope (A, Manage_Sec_Stack => False);
3899 Resolve (A, Etype (F));
3901 -- A small optimization: if one of the actuals is a concatenation
3902 -- create a block around a procedure call to recover stack space.
3903 -- This alleviates stack usage when several procedure calls in
3904 -- the same statement list use concatenation. We do not perform
3905 -- this wrapping for code statements, where the argument is a
3906 -- static string, and we want to preserve warnings involving
3907 -- sequences of such statements.
3909 elsif Expander_Active
3910 and then Nkind (A) = N_Op_Concat
3911 and then Nkind (N) = N_Procedure_Call_Statement
3912 and then not (Is_Intrinsic_Subprogram (Nam)
3913 and then Chars (Nam) = Name_Asm)
3914 and then not Static_Concatenation (A)
3916 Establish_Transient_Scope (A, Manage_Sec_Stack => False);
3917 Resolve (A, Etype (F));
3920 if Nkind (A) = N_Type_Conversion
3921 and then Is_Array_Type (Etype (F))
3922 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3924 (Is_Limited_Type (Etype (F))
3925 or else Is_Limited_Type (Etype (Expression (A))))
3928 ("conversion between unrelated limited array types not "
3929 & "allowed ('A'I-00246)", A);
3931 if Is_Limited_Type (Etype (F)) then
3932 Explain_Limited_Type (Etype (F), A);
3935 if Is_Limited_Type (Etype (Expression (A))) then
3936 Explain_Limited_Type (Etype (Expression (A)), A);
3940 -- (Ada 2005: AI-251): If the actual is an allocator whose
3941 -- directly designated type is a class-wide interface, we build
3942 -- an anonymous access type to use it as the type of the
3943 -- allocator. Later, when the subprogram call is expanded, if
3944 -- the interface has a secondary dispatch table the expander
3945 -- will add a type conversion to force the correct displacement
3948 if Nkind (A) = N_Allocator then
3950 DDT : constant Entity_Id :=
3951 Directly_Designated_Type (Base_Type (Etype (F)));
3953 New_Itype : Entity_Id;
3956 if Is_Class_Wide_Type (DDT)
3957 and then Is_Interface (DDT)
3959 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3960 Set_Etype (New_Itype, Etype (A));
3961 Set_Directly_Designated_Type
3962 (New_Itype, Directly_Designated_Type (Etype (A)));
3963 Set_Etype (A, New_Itype);
3966 -- Ada 2005, AI-162:If the actual is an allocator, the
3967 -- innermost enclosing statement is the master of the
3968 -- created object. This needs to be done with expansion
3969 -- enabled only, otherwise the transient scope will not
3970 -- be removed in the expansion of the wrapped construct.
3973 and then (Needs_Finalization (DDT)
3974 or else Has_Task (DDT))
3976 Establish_Transient_Scope
3977 (A, Manage_Sec_Stack => False);
3981 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3982 Check_Restriction (No_Access_Parameter_Allocators, A);
3986 -- (Ada 2005): The call may be to a primitive operation of a
3987 -- tagged synchronized type, declared outside of the type. In
3988 -- this case the controlling actual must be converted to its
3989 -- corresponding record type, which is the formal type. The
3990 -- actual may be a subtype, either because of a constraint or
3991 -- because it is a generic actual, so use base type to locate
3994 F_Typ := Base_Type (Etype (F));
3996 if Is_Tagged_Type (F_Typ)
3997 and then (Is_Concurrent_Type (F_Typ)
3998 or else Is_Concurrent_Record_Type (F_Typ))
4000 -- If the actual is overloaded, look for an interpretation
4001 -- that has a synchronized type.
4003 if not Is_Overloaded (A) then
4004 A_Typ := Base_Type (Etype (A));
4008 Index : Interp_Index;
4012 Get_First_Interp (A, Index, It);
4013 while Present (It.Typ) loop
4014 if Is_Concurrent_Type (It.Typ)
4015 or else Is_Concurrent_Record_Type (It.Typ)
4017 A_Typ := Base_Type (It.Typ);
4021 Get_Next_Interp (Index, It);
4027 Full_A_Typ : Entity_Id;
4030 if Present (Full_View (A_Typ)) then
4031 Full_A_Typ := Base_Type (Full_View (A_Typ));
4033 Full_A_Typ := A_Typ;
4036 -- Tagged synchronized type (case 1): the actual is a
4039 if Is_Concurrent_Type (A_Typ)
4040 and then Corresponding_Record_Type (A_Typ) = F_Typ
4043 Unchecked_Convert_To
4044 (Corresponding_Record_Type (A_Typ), A));
4045 Resolve (A, Etype (F));
4047 -- Tagged synchronized type (case 2): the formal is a
4050 elsif Ekind (Full_A_Typ) = E_Record_Type
4052 (Corresponding_Concurrent_Type (Full_A_Typ))
4053 and then Is_Concurrent_Type (F_Typ)
4054 and then Present (Corresponding_Record_Type (F_Typ))
4055 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4057 Resolve (A, Corresponding_Record_Type (F_Typ));
4062 Resolve (A, Etype (F));
4066 -- Not a synchronized operation
4069 Resolve (A, Etype (F));
4076 -- An actual cannot be an untagged formal incomplete type
4078 if Ekind (A_Typ) = E_Incomplete_Type
4079 and then not Is_Tagged_Type (A_Typ)
4080 and then Is_Generic_Type (A_Typ)
4083 ("invalid use of untagged formal incomplete type", A);
4086 if Comes_From_Source (Original_Node (N))
4087 and then Nkind_In (Original_Node (N), N_Function_Call,
4088 N_Procedure_Call_Statement)
4090 -- In formal mode, check that actual parameters matching
4091 -- formals of tagged types are objects (or ancestor type
4092 -- conversions of objects), not general expressions.
4094 if Is_Actual_Tagged_Parameter (A) then
4095 if Is_SPARK_05_Object_Reference (A) then
4098 elsif Nkind (A) = N_Type_Conversion then
4100 Operand : constant Node_Id := Expression (A);
4101 Operand_Typ : constant Entity_Id := Etype (Operand);
4102 Target_Typ : constant Entity_Id := A_Typ;
4105 if not Is_SPARK_05_Object_Reference (Operand) then
4106 Check_SPARK_05_Restriction
4107 ("object required", Operand);
4109 -- In formal mode, the only view conversions are those
4110 -- involving ancestor conversion of an extended type.
4113 (Is_Tagged_Type (Target_Typ)
4114 and then not Is_Class_Wide_Type (Target_Typ)
4115 and then Is_Tagged_Type (Operand_Typ)
4116 and then not Is_Class_Wide_Type (Operand_Typ)
4117 and then Is_Ancestor (Target_Typ, Operand_Typ))
4120 (F, E_Out_Parameter, E_In_Out_Parameter)
4122 Check_SPARK_05_Restriction
4123 ("ancestor conversion is the only permitted "
4124 & "view conversion", A);
4126 Check_SPARK_05_Restriction
4127 ("ancestor conversion required", A);
4136 Check_SPARK_05_Restriction ("object required", A);
4139 -- In formal mode, the only view conversions are those
4140 -- involving ancestor conversion of an extended type.
4142 elsif Nkind (A) = N_Type_Conversion
4143 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4145 Check_SPARK_05_Restriction
4146 ("ancestor conversion is the only permitted view "
4151 -- has warnings suppressed, then we reset Never_Set_In_Source for
4152 -- the calling entity. The reason for this is to catch cases like
4153 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4154 -- uses trickery to modify an IN parameter.
4156 if Ekind (F) = E_In_Parameter
4157 and then Is_Entity_Name (A)
4158 and then Present (Entity (A))
4159 and then Ekind (Entity (A)) = E_Variable
4160 and then Has_Warnings_Off (F_Typ)
4162 Set_Never_Set_In_Source (Entity (A), False);
4165 -- Perform error checks for IN and IN OUT parameters
4167 if Ekind (F) /= E_Out_Parameter then
4169 -- Check unset reference. For scalar parameters, it is clearly
4170 -- wrong to pass an uninitialized value as either an IN or
4171 -- IN-OUT parameter. For composites, it is also clearly an
4172 -- error to pass a completely uninitialized value as an IN
4173 -- parameter, but the case of IN OUT is trickier. We prefer
4174 -- not to give a warning here. For example, suppose there is
4175 -- a routine that sets some component of a record to False.
4176 -- It is perfectly reasonable to make this IN-OUT and allow
4177 -- either initialized or uninitialized records to be passed
4180 -- For partially initialized composite values, we also avoid
4181 -- warnings, since it is quite likely that we are passing a
4182 -- partially initialized value and only the initialized fields
4183 -- will in fact be read in the subprogram.
4185 if Is_Scalar_Type (A_Typ)
4186 or else (Ekind (F) = E_In_Parameter
4187 and then not Is_Partially_Initialized_Type (A_Typ))
4189 Check_Unset_Reference (A);
4192 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4193 -- actual to a nested call, since this constitutes a reading of
4194 -- the parameter, which is not allowed.
4196 if Ada_Version = Ada_83
4197 and then Is_Entity_Name (A)
4198 and then Ekind (Entity (A)) = E_Out_Parameter
4200 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4204 -- In -gnatd.q mode, forget that a given array is constant when
4205 -- it is passed as an IN parameter to a foreign-convention
4206 -- subprogram. This is in case the subprogram evilly modifies the
4207 -- object. Of course, correct code would use IN OUT.
4210 and then Ekind (F) = E_In_Parameter
4211 and then Has_Foreign_Convention (Nam)
4212 and then Is_Array_Type (F_Typ)
4213 and then Nkind (A) in N_Has_Entity
4214 and then Present (Entity (A))
4216 Set_Is_True_Constant (Entity (A), False);
4219 -- Case of OUT or IN OUT parameter
4221 if Ekind (F) /= E_In_Parameter then
4223 -- For an Out parameter, check for useless assignment. Note
4224 -- that we can't set Last_Assignment this early, because we may
4225 -- kill current values in Resolve_Call, and that call would
4226 -- clobber the Last_Assignment field.
4228 -- Note: call Warn_On_Useless_Assignment before doing the check
4229 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4230 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4231 -- reflects the last assignment, not this one.
4233 if Ekind (F) = E_Out_Parameter then
4234 if Warn_On_Modified_As_Out_Parameter (F)
4235 and then Is_Entity_Name (A)
4236 and then Present (Entity (A))
4237 and then Comes_From_Source (N)
4239 Warn_On_Useless_Assignment (Entity (A), A);
4243 -- Validate the form of the actual. Note that the call to
4244 -- Is_OK_Variable_For_Out_Formal generates the required
4245 -- reference in this case.
4247 -- A call to an initialization procedure for an aggregate
4248 -- component may initialize a nested component of a constant
4249 -- designated object. In this context the object is variable.
4251 if not Is_OK_Variable_For_Out_Formal (A)
4252 and then not Is_Init_Proc (Nam)
4254 Error_Msg_NE ("actual for& must be a variable", A, F);
4256 if Is_Subprogram (Current_Scope) then
4257 if Is_Invariant_Procedure (Current_Scope)
4258 or else Is_Partial_Invariant_Procedure (Current_Scope)
4261 ("function used in invariant cannot modify its "
4264 elsif Is_Predicate_Function (Current_Scope) then
4266 ("function used in predicate cannot modify its "
4272 -- What's the following about???
4274 if Is_Entity_Name (A) then
4275 Kill_Checks (Entity (A));
4281 if Etype (A) = Any_Type then
4282 Set_Etype (N, Any_Type);
4286 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4288 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4290 -- Apply predicate tests except in certain special cases. Note
4291 -- that it might be more consistent to apply these only when
4292 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4293 -- for the outbound predicate tests ??? In any case indicate
4294 -- the function being called, for better warnings if the call
4295 -- leads to an infinite recursion.
4297 if Predicate_Tests_On_Arguments (Nam) then
4298 Apply_Predicate_Check (A, F_Typ, Nam);
4301 -- Apply required constraint checks
4303 -- Gigi looks at the check flag and uses the appropriate types.
4304 -- For now since one flag is used there is an optimization
4305 -- which might not be done in the IN OUT case since Gigi does
4306 -- not do any analysis. More thought required about this ???
4308 -- In fact is this comment obsolete??? doesn't the expander now
4309 -- generate all these tests anyway???
4311 if Is_Scalar_Type (Etype (A)) then
4312 Apply_Scalar_Range_Check (A, F_Typ);
4314 elsif Is_Array_Type (Etype (A)) then
4315 Apply_Length_Check (A, F_Typ);
4317 elsif Is_Record_Type (F_Typ)
4318 and then Has_Discriminants (F_Typ)
4319 and then Is_Constrained (F_Typ)
4320 and then (not Is_Derived_Type (F_Typ)
4321 or else Comes_From_Source (Nam))
4323 Apply_Discriminant_Check (A, F_Typ);
4325 -- For view conversions of a discriminated object, apply
4326 -- check to object itself, the conversion alreay has the
4329 if Nkind (A) = N_Type_Conversion
4330 and then Is_Constrained (Etype (Expression (A)))
4332 Apply_Discriminant_Check (Expression (A), F_Typ);
4335 elsif Is_Access_Type (F_Typ)
4336 and then Is_Array_Type (Designated_Type (F_Typ))
4337 and then Is_Constrained (Designated_Type (F_Typ))
4339 Apply_Length_Check (A, F_Typ);
4341 elsif Is_Access_Type (F_Typ)
4342 and then Has_Discriminants (Designated_Type (F_Typ))
4343 and then Is_Constrained (Designated_Type (F_Typ))
4345 Apply_Discriminant_Check (A, F_Typ);
4348 Apply_Range_Check (A, F_Typ);
4351 -- Ada 2005 (AI-231): Note that the controlling parameter case
4352 -- already existed in Ada 95, which is partially checked
4353 -- elsewhere (see Checks), and we don't want the warning
4354 -- message to differ.
4356 if Is_Access_Type (F_Typ)
4357 and then Can_Never_Be_Null (F_Typ)
4358 and then Known_Null (A)
4360 if Is_Controlling_Formal (F) then
4361 Apply_Compile_Time_Constraint_Error
4363 Msg => "null value not allowed here??",
4364 Reason => CE_Access_Check_Failed);
4366 elsif Ada_Version >= Ada_2005 then
4367 Apply_Compile_Time_Constraint_Error
4369 Msg => "(Ada 2005) null not allowed in "
4370 & "null-excluding formal??",
4371 Reason => CE_Null_Not_Allowed);
4376 -- Checks for OUT parameters and IN OUT parameters
4378 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4380 -- If there is a type conversion, make sure the return value
4381 -- meets the constraints of the variable before the conversion.
4383 if Nkind (A) = N_Type_Conversion then
4384 if Is_Scalar_Type (A_Typ) then
4385 Apply_Scalar_Range_Check
4386 (Expression (A), Etype (Expression (A)), A_Typ);
4388 -- In addition, the returned value of the parameter must
4389 -- satisfy the bounds of the object type (see comment
4392 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4396 (Expression (A), Etype (Expression (A)), A_Typ);
4399 -- If no conversion, apply scalar range checks and length check
4400 -- based on the subtype of the actual (NOT that of the formal).
4401 -- This indicates that the check takes place on return from the
4402 -- call. During expansion the required constraint checks are
4403 -- inserted. In GNATprove mode, in the absence of expansion,
4404 -- the flag indicates that the returned value is valid.
4407 if Is_Scalar_Type (F_Typ) then
4408 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4410 elsif Is_Array_Type (F_Typ)
4411 and then Ekind (F) = E_Out_Parameter
4413 Apply_Length_Check (A, F_Typ);
4415 Apply_Range_Check (A, A_Typ, F_Typ);
4419 -- Note: we do not apply the predicate checks for the case of
4420 -- OUT and IN OUT parameters. They are instead applied in the
4421 -- Expand_Actuals routine in Exp_Ch6.
4424 -- An actual associated with an access parameter is implicitly
4425 -- converted to the anonymous access type of the formal and must
4426 -- satisfy the legality checks for access conversions.
4428 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4429 if not Valid_Conversion (A, F_Typ, A) then
4431 ("invalid implicit conversion for access parameter", A);
4434 -- If the actual is an access selected component of a variable,
4435 -- the call may modify its designated object. It is reasonable
4436 -- to treat this as a potential modification of the enclosing
4437 -- record, to prevent spurious warnings that it should be
4438 -- declared as a constant, because intuitively programmers
4439 -- regard the designated subcomponent as part of the record.
4441 if Nkind (A) = N_Selected_Component
4442 and then Is_Entity_Name (Prefix (A))
4443 and then not Is_Constant_Object (Entity (Prefix (A)))
4445 Note_Possible_Modification (A, Sure => False);
4449 -- Check bad case of atomic/volatile argument (RM C.6(12))
4451 if Is_By_Reference_Type (Etype (F))
4452 and then Comes_From_Source (N)
4454 if Is_Atomic_Object (A)
4455 and then not Is_Atomic (Etype (F))
4458 ("cannot pass atomic argument to non-atomic formal&",
4461 elsif Is_Volatile_Object (A)
4462 and then not Is_Volatile (Etype (F))
4465 ("cannot pass volatile argument to non-volatile formal&",
4470 -- Check that subprograms don't have improper controlling
4471 -- arguments (RM 3.9.2 (9)).
4473 -- A primitive operation may have an access parameter of an
4474 -- incomplete tagged type, but a dispatching call is illegal
4475 -- if the type is still incomplete.
4477 if Is_Controlling_Formal (F) then
4478 Set_Is_Controlling_Actual (A);
4480 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4482 Desig : constant Entity_Id := Designated_Type (Etype (F));
4484 if Ekind (Desig) = E_Incomplete_Type
4485 and then No (Full_View (Desig))
4486 and then No (Non_Limited_View (Desig))
4489 ("premature use of incomplete type& "
4490 & "in dispatching call", A, Desig);
4495 elsif Nkind (A) = N_Explicit_Dereference then
4496 Validate_Remote_Access_To_Class_Wide_Type (A);
4499 -- Apply legality rule 3.9.2 (9/1)
4501 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4502 and then not Is_Class_Wide_Type (F_Typ)
4503 and then not Is_Controlling_Formal (F)
4504 and then not In_Instance
4506 Error_Msg_N ("class-wide argument not allowed here!", A);
4508 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4509 Error_Msg_Node_2 := F_Typ;
4511 ("& is not a dispatching operation of &!", A, Nam);
4514 -- Apply the checks described in 3.10.2(27): if the context is a
4515 -- specific access-to-object, the actual cannot be class-wide.
4516 -- Use base type to exclude access_to_subprogram cases.
4518 elsif Is_Access_Type (A_Typ)
4519 and then Is_Access_Type (F_Typ)
4520 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4521 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4522 or else (Nkind (A) = N_Attribute_Reference
4524 Is_Class_Wide_Type (Etype (Prefix (A)))))
4525 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4526 and then not Is_Controlling_Formal (F)
4528 -- Disable these checks for call to imported C++ subprograms
4531 (Is_Entity_Name (Name (N))
4532 and then Is_Imported (Entity (Name (N)))
4533 and then Convention (Entity (Name (N))) = Convention_CPP)
4536 ("access to class-wide argument not allowed here!", A);
4538 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4539 Error_Msg_Node_2 := Designated_Type (F_Typ);
4541 ("& is not a dispatching operation of &!", A, Nam);
4545 Check_Aliased_Parameter;
4549 -- If it is a named association, treat the selector_name as a
4550 -- proper identifier, and mark the corresponding entity.
4552 if Nkind (Parent (A)) = N_Parameter_Association
4554 -- Ignore reference in SPARK mode, as it refers to an entity not
4555 -- in scope at the point of reference, so the reference should
4556 -- be ignored for computing effects of subprograms.
4558 and then not GNATprove_Mode
4560 -- If subprogram is overridden, use name of formal that
4563 if Present (Real_Subp) then
4564 Set_Entity (Selector_Name (Parent (A)), Real_F);
4565 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4568 Set_Entity (Selector_Name (Parent (A)), F);
4569 Generate_Reference (F, Selector_Name (Parent (A)));
4570 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4571 Generate_Reference (F_Typ, N, ' ');
4577 if Ekind (F) /= E_Out_Parameter then
4578 Check_Unset_Reference (A);
4581 -- The following checks are only relevant when SPARK_Mode is on as
4582 -- they are not standard Ada legality rule. Internally generated
4583 -- temporaries are ignored.
4585 if SPARK_Mode = On and then Comes_From_Source (A) then
4587 -- An effectively volatile object may act as an actual when the
4588 -- corresponding formal is of a non-scalar effectively volatile
4589 -- type (SPARK RM 7.1.3(11)).
4591 if not Is_Scalar_Type (Etype (F))
4592 and then Is_Effectively_Volatile (Etype (F))
4596 -- An effectively volatile object may act as an actual in a
4597 -- call to an instance of Unchecked_Conversion.
4598 -- (SPARK RM 7.1.3(11)).
4600 elsif Is_Unchecked_Conversion_Instance (Nam) then
4603 -- The actual denotes an object
4605 elsif Is_Effectively_Volatile_Object (A) then
4607 ("volatile object cannot act as actual in a call (SPARK "
4608 & "RM 7.1.3(11))", A);
4610 -- Otherwise the actual denotes an expression. Inspect the
4611 -- expression and flag each effectively volatile object with
4612 -- enabled property Async_Writers or Effective_Reads as illegal
4613 -- because it apprears within an interfering context. Note that
4614 -- this is usually done in Resolve_Entity_Name, but when the
4615 -- effectively volatile object appears as an actual in a call,
4616 -- the call must be resolved first.
4619 Flag_Effectively_Volatile_Objects (A);
4622 -- An effectively volatile variable cannot act as an actual
4623 -- parameter in a procedure call when the variable has enabled
4624 -- property Effective_Reads and the corresponding formal is of
4625 -- mode IN (SPARK RM 7.1.3(10)).
4627 if Ekind (Nam) = E_Procedure
4628 and then Ekind (F) = E_In_Parameter
4629 and then Is_Entity_Name (A)
4633 if Ekind (A_Id) = E_Variable
4634 and then Is_Effectively_Volatile (Etype (A_Id))
4635 and then Effective_Reads_Enabled (A_Id)
4638 ("effectively volatile variable & cannot appear as "
4639 & "actual in procedure call", A, A_Id);
4641 Error_Msg_Name_1 := Name_Effective_Reads;
4642 Error_Msg_N ("\\variable has enabled property %", A);
4643 Error_Msg_N ("\\corresponding formal has mode IN", A);
4648 -- A formal parameter of a specific tagged type whose related
4649 -- subprogram is subject to pragma Extensions_Visible with value
4650 -- "False" cannot act as an actual in a subprogram with value
4651 -- "True" (SPARK RM 6.1.7(3)).
4653 if Is_EVF_Expression (A)
4654 and then Extensions_Visible_Status (Nam) =
4655 Extensions_Visible_True
4658 ("formal parameter cannot act as actual parameter when "
4659 & "Extensions_Visible is False", A);
4661 ("\subprogram & has Extensions_Visible True", A, Nam);
4664 -- The actual parameter of a Ghost subprogram whose formal is of
4665 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4667 if Comes_From_Source (Nam)
4668 and then Is_Ghost_Entity (Nam)
4669 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4670 and then Is_Entity_Name (A)
4671 and then Present (Entity (A))
4672 and then not Is_Ghost_Entity (Entity (A))
4675 ("non-ghost variable & cannot appear as actual in call to "
4676 & "ghost procedure", A, Entity (A));
4678 if Ekind (F) = E_In_Out_Parameter then
4679 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4681 Error_Msg_N ("\corresponding formal has mode OUT", A);
4687 -- Case where actual is not present
4695 if Present (Real_Subp) then
4696 Next_Formal (Real_F);
4699 end Resolve_Actuals;
4701 -----------------------
4702 -- Resolve_Allocator --
4703 -----------------------
4705 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4706 Desig_T : constant Entity_Id := Designated_Type (Typ);
4707 E : constant Node_Id := Expression (N);
4709 Discrim : Entity_Id;
4712 Assoc : Node_Id := Empty;
4715 procedure Check_Allocator_Discrim_Accessibility
4716 (Disc_Exp : Node_Id;
4717 Alloc_Typ : Entity_Id);
4718 -- Check that accessibility level associated with an access discriminant
4719 -- initialized in an allocator by the expression Disc_Exp is not deeper
4720 -- than the level of the allocator type Alloc_Typ. An error message is
4721 -- issued if this condition is violated. Specialized checks are done for
4722 -- the cases of a constraint expression which is an access attribute or
4723 -- an access discriminant.
4725 function In_Dispatching_Context return Boolean;
4726 -- If the allocator is an actual in a call, it is allowed to be class-
4727 -- wide when the context is not because it is a controlling actual.
4729 -------------------------------------------
4730 -- Check_Allocator_Discrim_Accessibility --
4731 -------------------------------------------
4733 procedure Check_Allocator_Discrim_Accessibility
4734 (Disc_Exp : Node_Id;
4735 Alloc_Typ : Entity_Id)
4738 if Type_Access_Level (Etype (Disc_Exp)) >
4739 Deepest_Type_Access_Level (Alloc_Typ)
4742 ("operand type has deeper level than allocator type", Disc_Exp);
4744 -- When the expression is an Access attribute the level of the prefix
4745 -- object must not be deeper than that of the allocator's type.
4747 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4748 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4750 and then Object_Access_Level (Prefix (Disc_Exp)) >
4751 Deepest_Type_Access_Level (Alloc_Typ)
4754 ("prefix of attribute has deeper level than allocator type",
4757 -- When the expression is an access discriminant the check is against
4758 -- the level of the prefix object.
4760 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4761 and then Nkind (Disc_Exp) = N_Selected_Component
4762 and then Object_Access_Level (Prefix (Disc_Exp)) >
4763 Deepest_Type_Access_Level (Alloc_Typ)
4766 ("access discriminant has deeper level than allocator type",
4769 -- All other cases are legal
4774 end Check_Allocator_Discrim_Accessibility;
4776 ----------------------------
4777 -- In_Dispatching_Context --
4778 ----------------------------
4780 function In_Dispatching_Context return Boolean is
4781 Par : constant Node_Id := Parent (N);
4784 return Nkind (Par) in N_Subprogram_Call
4785 and then Is_Entity_Name (Name (Par))
4786 and then Is_Dispatching_Operation (Entity (Name (Par)));
4787 end In_Dispatching_Context;
4789 -- Start of processing for Resolve_Allocator
4792 -- Replace general access with specific type
4794 if Ekind (Etype (N)) = E_Allocator_Type then
4795 Set_Etype (N, Base_Type (Typ));
4798 if Is_Abstract_Type (Typ) then
4799 Error_Msg_N ("type of allocator cannot be abstract", N);
4802 -- For qualified expression, resolve the expression using the given
4803 -- subtype (nothing to do for type mark, subtype indication)
4805 if Nkind (E) = N_Qualified_Expression then
4806 if Is_Class_Wide_Type (Etype (E))
4807 and then not Is_Class_Wide_Type (Desig_T)
4808 and then not In_Dispatching_Context
4811 ("class-wide allocator not allowed for this access type", N);
4814 Resolve (Expression (E), Etype (E));
4815 Check_Non_Static_Context (Expression (E));
4816 Check_Unset_Reference (Expression (E));
4818 -- Allocators generated by the build-in-place expansion mechanism
4819 -- are explicitly marked as coming from source but do not need to be
4820 -- checked for limited initialization. To exclude this case, ensure
4821 -- that the parent of the allocator is a source node.
4822 -- The return statement constructed for an Expression_Function does
4823 -- not come from source but requires a limited check.
4825 if Is_Limited_Type (Etype (E))
4826 and then Comes_From_Source (N)
4828 (Comes_From_Source (Parent (N))
4830 (Ekind (Current_Scope) = E_Function
4831 and then Nkind (Original_Node (Unit_Declaration_Node
4832 (Current_Scope))) = N_Expression_Function))
4833 and then not In_Instance_Body
4835 if not OK_For_Limited_Init (Etype (E), Expression (E)) then
4836 if Nkind (Parent (N)) = N_Assignment_Statement then
4838 ("illegal expression for initialized allocator of a "
4839 & "limited type (RM 7.5 (2.7/2))", N);
4842 ("initialization not allowed for limited types", N);
4845 Explain_Limited_Type (Etype (E), N);
4849 -- A qualified expression requires an exact match of the type. Class-
4850 -- wide matching is not allowed.
4852 if (Is_Class_Wide_Type (Etype (Expression (E)))
4853 or else Is_Class_Wide_Type (Etype (E)))
4854 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4856 Wrong_Type (Expression (E), Etype (E));
4859 -- Calls to build-in-place functions are not currently supported in
4860 -- allocators for access types associated with a simple storage pool.
4861 -- Supporting such allocators may require passing additional implicit
4862 -- parameters to build-in-place functions (or a significant revision
4863 -- of the current b-i-p implementation to unify the handling for
4864 -- multiple kinds of storage pools). ???
4866 if Is_Limited_View (Desig_T)
4867 and then Nkind (Expression (E)) = N_Function_Call
4870 Pool : constant Entity_Id :=
4871 Associated_Storage_Pool (Root_Type (Typ));
4875 Present (Get_Rep_Pragma
4876 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4879 ("limited function calls not yet supported in simple "
4880 & "storage pool allocators", Expression (E));
4885 -- A special accessibility check is needed for allocators that
4886 -- constrain access discriminants. The level of the type of the
4887 -- expression used to constrain an access discriminant cannot be
4888 -- deeper than the type of the allocator (in contrast to access
4889 -- parameters, where the level of the actual can be arbitrary).
4891 -- We can't use Valid_Conversion to perform this check because in
4892 -- general the type of the allocator is unrelated to the type of
4893 -- the access discriminant.
4895 if Ekind (Typ) /= E_Anonymous_Access_Type
4896 or else Is_Local_Anonymous_Access (Typ)
4898 Subtyp := Entity (Subtype_Mark (E));
4900 Aggr := Original_Node (Expression (E));
4902 if Has_Discriminants (Subtyp)
4903 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4905 Discrim := First_Discriminant (Base_Type (Subtyp));
4907 -- Get the first component expression of the aggregate
4909 if Present (Expressions (Aggr)) then
4910 Disc_Exp := First (Expressions (Aggr));
4912 elsif Present (Component_Associations (Aggr)) then
4913 Assoc := First (Component_Associations (Aggr));
4915 if Present (Assoc) then
4916 Disc_Exp := Expression (Assoc);
4925 while Present (Discrim) and then Present (Disc_Exp) loop
4926 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4927 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4930 Next_Discriminant (Discrim);
4932 if Present (Discrim) then
4933 if Present (Assoc) then
4935 Disc_Exp := Expression (Assoc);
4937 elsif Present (Next (Disc_Exp)) then
4941 Assoc := First (Component_Associations (Aggr));
4943 if Present (Assoc) then
4944 Disc_Exp := Expression (Assoc);
4954 -- For a subtype mark or subtype indication, freeze the subtype
4957 Freeze_Expression (E);
4959 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4961 ("initialization required for access-to-constant allocator", N);
4964 -- A special accessibility check is needed for allocators that
4965 -- constrain access discriminants. The level of the type of the
4966 -- expression used to constrain an access discriminant cannot be
4967 -- deeper than the type of the allocator (in contrast to access
4968 -- parameters, where the level of the actual can be arbitrary).
4969 -- We can't use Valid_Conversion to perform this check because
4970 -- in general the type of the allocator is unrelated to the type
4971 -- of the access discriminant.
4973 if Nkind (Original_Node (E)) = N_Subtype_Indication
4974 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4975 or else Is_Local_Anonymous_Access (Typ))
4977 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4979 if Has_Discriminants (Subtyp) then
4980 Discrim := First_Discriminant (Base_Type (Subtyp));
4981 Constr := First (Constraints (Constraint (Original_Node (E))));
4982 while Present (Discrim) and then Present (Constr) loop
4983 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4984 if Nkind (Constr) = N_Discriminant_Association then
4985 Disc_Exp := Original_Node (Expression (Constr));
4987 Disc_Exp := Original_Node (Constr);
4990 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4993 Next_Discriminant (Discrim);
5000 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
5001 -- check that the level of the type of the created object is not deeper
5002 -- than the level of the allocator's access type, since extensions can
5003 -- now occur at deeper levels than their ancestor types. This is a
5004 -- static accessibility level check; a run-time check is also needed in
5005 -- the case of an initialized allocator with a class-wide argument (see
5006 -- Expand_Allocator_Expression).
5008 if Ada_Version >= Ada_2005
5009 and then Is_Class_Wide_Type (Desig_T)
5012 Exp_Typ : Entity_Id;
5015 if Nkind (E) = N_Qualified_Expression then
5016 Exp_Typ := Etype (E);
5017 elsif Nkind (E) = N_Subtype_Indication then
5018 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
5020 Exp_Typ := Entity (E);
5023 if Type_Access_Level (Exp_Typ) >
5024 Deepest_Type_Access_Level (Typ)
5026 if In_Instance_Body then
5027 Error_Msg_Warn := SPARK_Mode /= On;
5029 ("type in allocator has deeper level than designated "
5030 & "class-wide type<<", E);
5031 Error_Msg_N ("\Program_Error [<<", E);
5034 Make_Raise_Program_Error (Sloc (N),
5035 Reason => PE_Accessibility_Check_Failed));
5038 -- Do not apply Ada 2005 accessibility checks on a class-wide
5039 -- allocator if the type given in the allocator is a formal
5040 -- type. A run-time check will be performed in the instance.
5042 elsif not Is_Generic_Type (Exp_Typ) then
5044 ("type in allocator has deeper level than designated "
5045 & "class-wide type", E);
5051 -- Check for allocation from an empty storage pool. But do not complain
5052 -- if it's a return statement for a build-in-place function, because the
5053 -- allocator is there just in case the caller uses an allocator. If the
5054 -- caller does use an allocator, it will be caught at the call site.
5056 if No_Pool_Assigned (Typ)
5057 and then not Alloc_For_BIP_Return (N)
5059 Error_Msg_N ("allocation from empty storage pool!", N);
5061 -- If the context is an unchecked conversion, as may happen within an
5062 -- inlined subprogram, the allocator is being resolved with its own
5063 -- anonymous type. In that case, if the target type has a specific
5064 -- storage pool, it must be inherited explicitly by the allocator type.
5066 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
5067 and then No (Associated_Storage_Pool (Typ))
5069 Set_Associated_Storage_Pool
5070 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
5073 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
5074 Check_Restriction (No_Anonymous_Allocators, N);
5077 -- Check that an allocator with task parts isn't for a nested access
5078 -- type when restriction No_Task_Hierarchy applies.
5080 if not Is_Library_Level_Entity (Base_Type (Typ))
5081 and then Has_Task (Base_Type (Desig_T))
5083 Check_Restriction (No_Task_Hierarchy, N);
5086 -- An illegal allocator may be rewritten as a raise Program_Error
5089 if Nkind (N) = N_Allocator then
5091 -- Avoid coextension processing for an allocator that is the
5092 -- expansion of a build-in-place function call.
5094 if Nkind (Original_Node (N)) = N_Allocator
5095 and then Nkind (Expression (Original_Node (N))) =
5096 N_Qualified_Expression
5097 and then Nkind (Expression (Expression (Original_Node (N)))) =
5099 and then Is_Expanded_Build_In_Place_Call
5100 (Expression (Expression (Original_Node (N))))
5102 null; -- b-i-p function call case
5105 -- An anonymous access discriminant is the definition of a
5108 if Ekind (Typ) = E_Anonymous_Access_Type
5109 and then Nkind (Associated_Node_For_Itype (Typ)) =
5110 N_Discriminant_Specification
5113 Discr : constant Entity_Id :=
5114 Defining_Identifier (Associated_Node_For_Itype (Typ));
5117 Check_Restriction (No_Coextensions, N);
5119 -- Ada 2012 AI05-0052: If the designated type of the
5120 -- allocator is limited, then the allocator shall not
5121 -- be used to define the value of an access discriminant
5122 -- unless the discriminated type is immutably limited.
5124 if Ada_Version >= Ada_2012
5125 and then Is_Limited_Type (Desig_T)
5126 and then not Is_Limited_View (Scope (Discr))
5129 ("only immutably limited types can have anonymous "
5130 & "access discriminants designating a limited type",
5135 -- Avoid marking an allocator as a dynamic coextension if it is
5136 -- within a static construct.
5138 if not Is_Static_Coextension (N) then
5139 Set_Is_Dynamic_Coextension (N);
5141 -- Finalization and deallocation of coextensions utilizes an
5142 -- approximate implementation which does not directly adhere
5143 -- to the semantic rules. Warn on potential issues involving
5146 if Is_Controlled (Desig_T) then
5148 ("??coextension will not be finalized when its "
5149 & "associated owner is deallocated or finalized", N);
5152 ("??coextension will not be deallocated when its "
5153 & "associated owner is deallocated", N);
5157 -- Cleanup for potential static coextensions
5160 Set_Is_Dynamic_Coextension (N, False);
5161 Set_Is_Static_Coextension (N, False);
5163 -- Anonymous access-to-controlled objects are not finalized on
5164 -- time because this involves run-time ownership and currently
5165 -- this property is not available. In rare cases the object may
5166 -- not be finalized at all. Warn on potential issues involving
5167 -- anonymous access-to-controlled objects.
5169 if Ekind (Typ) = E_Anonymous_Access_Type
5170 and then Is_Controlled_Active (Desig_T)
5173 ("??object designated by anonymous access object might "
5174 & "not be finalized until its enclosing library unit "
5175 & "goes out of scope", N);
5176 Error_Msg_N ("\use named access type instead", N);
5182 -- Report a simple error: if the designated object is a local task,
5183 -- its body has not been seen yet, and its activation will fail an
5184 -- elaboration check.
5186 if Is_Task_Type (Desig_T)
5187 and then Scope (Base_Type (Desig_T)) = Current_Scope
5188 and then Is_Compilation_Unit (Current_Scope)
5189 and then Ekind (Current_Scope) = E_Package
5190 and then not In_Package_Body (Current_Scope)
5192 Error_Msg_Warn := SPARK_Mode /= On;
5193 Error_Msg_N ("cannot activate task before body seen<<", N);
5194 Error_Msg_N ("\Program_Error [<<", N);
5197 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5198 -- type with a task component on a subpool. This action must raise
5199 -- Program_Error at runtime.
5201 if Ada_Version >= Ada_2012
5202 and then Nkind (N) = N_Allocator
5203 and then Present (Subpool_Handle_Name (N))
5204 and then Has_Task (Desig_T)
5206 Error_Msg_Warn := SPARK_Mode /= On;
5207 Error_Msg_N ("cannot allocate task on subpool<<", N);
5208 Error_Msg_N ("\Program_Error [<<", N);
5211 Make_Raise_Program_Error (Sloc (N),
5212 Reason => PE_Explicit_Raise));
5215 end Resolve_Allocator;
5217 ---------------------------
5218 -- Resolve_Arithmetic_Op --
5219 ---------------------------
5221 -- Used for resolving all arithmetic operators except exponentiation
5223 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5224 L : constant Node_Id := Left_Opnd (N);
5225 R : constant Node_Id := Right_Opnd (N);
5226 TL : constant Entity_Id := Base_Type (Etype (L));
5227 TR : constant Entity_Id := Base_Type (Etype (R));
5231 B_Typ : constant Entity_Id := Base_Type (Typ);
5232 -- We do the resolution using the base type, because intermediate values
5233 -- in expressions always are of the base type, not a subtype of it.
5235 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5236 -- Returns True if N is in a context that expects "any real type"
5238 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5239 -- Return True iff given type is Integer or universal real/integer
5241 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5242 -- Choose type of integer literal in fixed-point operation to conform
5243 -- to available fixed-point type. T is the type of the other operand,
5244 -- which is needed to determine the expected type of N.
5246 procedure Set_Operand_Type (N : Node_Id);
5247 -- Set operand type to T if universal
5249 -------------------------------
5250 -- Expected_Type_Is_Any_Real --
5251 -------------------------------
5253 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5255 -- N is the expression after "delta" in a fixed_point_definition;
5258 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5259 N_Decimal_Fixed_Point_Definition,
5261 -- N is one of the bounds in a real_range_specification;
5264 N_Real_Range_Specification,
5266 -- N is the expression of a delta_constraint;
5269 N_Delta_Constraint);
5270 end Expected_Type_Is_Any_Real;
5272 -----------------------------
5273 -- Is_Integer_Or_Universal --
5274 -----------------------------
5276 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5278 Index : Interp_Index;
5282 if not Is_Overloaded (N) then
5284 return Base_Type (T) = Base_Type (Standard_Integer)
5285 or else T = Universal_Integer
5286 or else T = Universal_Real;
5288 Get_First_Interp (N, Index, It);
5289 while Present (It.Typ) loop
5290 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5291 or else It.Typ = Universal_Integer
5292 or else It.Typ = Universal_Real
5297 Get_Next_Interp (Index, It);
5302 end Is_Integer_Or_Universal;
5304 ----------------------------
5305 -- Set_Mixed_Mode_Operand --
5306 ----------------------------
5308 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5309 Index : Interp_Index;
5313 if Universal_Interpretation (N) = Universal_Integer then
5315 -- A universal integer literal is resolved as standard integer
5316 -- except in the case of a fixed-point result, where we leave it
5317 -- as universal (to be handled by Exp_Fixd later on)
5319 if Is_Fixed_Point_Type (T) then
5320 Resolve (N, Universal_Integer);
5322 Resolve (N, Standard_Integer);
5325 elsif Universal_Interpretation (N) = Universal_Real
5326 and then (T = Base_Type (Standard_Integer)
5327 or else T = Universal_Integer
5328 or else T = Universal_Real)
5330 -- A universal real can appear in a fixed-type context. We resolve
5331 -- the literal with that context, even though this might raise an
5332 -- exception prematurely (the other operand may be zero).
5336 elsif Etype (N) = Base_Type (Standard_Integer)
5337 and then T = Universal_Real
5338 and then Is_Overloaded (N)
5340 -- Integer arg in mixed-mode operation. Resolve with universal
5341 -- type, in case preference rule must be applied.
5343 Resolve (N, Universal_Integer);
5345 elsif Etype (N) = T and then B_Typ /= Universal_Fixed then
5347 -- If the operand is part of a fixed multiplication operation,
5348 -- a conversion will be applied to each operand, so resolve it
5349 -- with its own type.
5351 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
5355 -- Not a mixed-mode operation, resolve with context
5360 elsif Etype (N) = Any_Fixed then
5362 -- N may itself be a mixed-mode operation, so use context type
5366 elsif Is_Fixed_Point_Type (T)
5367 and then B_Typ = Universal_Fixed
5368 and then Is_Overloaded (N)
5370 -- Must be (fixed * fixed) operation, operand must have one
5371 -- compatible interpretation.
5373 Resolve (N, Any_Fixed);
5375 elsif Is_Fixed_Point_Type (B_Typ)
5376 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5377 and then Is_Overloaded (N)
5379 -- C * F(X) in a fixed context, where C is a real literal or a
5380 -- fixed-point expression. F must have either a fixed type
5381 -- interpretation or an integer interpretation, but not both.
5383 Get_First_Interp (N, Index, It);
5384 while Present (It.Typ) loop
5385 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5386 if Analyzed (N) then
5387 Error_Msg_N ("ambiguous operand in fixed operation", N);
5389 Resolve (N, Standard_Integer);
5392 elsif Is_Fixed_Point_Type (It.Typ) then
5393 if Analyzed (N) then
5394 Error_Msg_N ("ambiguous operand in fixed operation", N);
5396 Resolve (N, It.Typ);
5400 Get_Next_Interp (Index, It);
5403 -- Reanalyze the literal with the fixed type of the context. If
5404 -- context is Universal_Fixed, we are within a conversion, leave
5405 -- the literal as a universal real because there is no usable
5406 -- fixed type, and the target of the conversion plays no role in
5420 if B_Typ = Universal_Fixed
5421 and then Nkind (Op2) = N_Real_Literal
5423 T2 := Universal_Real;
5428 Set_Analyzed (Op2, False);
5432 -- A universal real conditional expression can appear in a fixed-type
5433 -- context and must be resolved with that context to facilitate the
5434 -- code generation in the back end.
5436 elsif Nkind_In (N, N_Case_Expression, N_If_Expression)
5437 and then Etype (N) = Universal_Real
5438 and then Is_Fixed_Point_Type (B_Typ)
5445 end Set_Mixed_Mode_Operand;
5447 ----------------------
5448 -- Set_Operand_Type --
5449 ----------------------
5451 procedure Set_Operand_Type (N : Node_Id) is
5453 if Etype (N) = Universal_Integer
5454 or else Etype (N) = Universal_Real
5458 end Set_Operand_Type;
5460 -- Start of processing for Resolve_Arithmetic_Op
5463 if Comes_From_Source (N)
5464 and then Ekind (Entity (N)) = E_Function
5465 and then Is_Imported (Entity (N))
5466 and then Is_Intrinsic_Subprogram (Entity (N))
5468 Resolve_Intrinsic_Operator (N, Typ);
5471 -- Special-case for mixed-mode universal expressions or fixed point type
5472 -- operation: each argument is resolved separately. The same treatment
5473 -- is required if one of the operands of a fixed point operation is
5474 -- universal real, since in this case we don't do a conversion to a
5475 -- specific fixed-point type (instead the expander handles the case).
5477 -- Set the type of the node to its universal interpretation because
5478 -- legality checks on an exponentiation operand need the context.
5480 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5481 and then Present (Universal_Interpretation (L))
5482 and then Present (Universal_Interpretation (R))
5484 Set_Etype (N, B_Typ);
5485 Resolve (L, Universal_Interpretation (L));
5486 Resolve (R, Universal_Interpretation (R));
5488 elsif (B_Typ = Universal_Real
5489 or else Etype (N) = Universal_Fixed
5490 or else (Etype (N) = Any_Fixed
5491 and then Is_Fixed_Point_Type (B_Typ))
5492 or else (Is_Fixed_Point_Type (B_Typ)
5493 and then (Is_Integer_Or_Universal (L)
5495 Is_Integer_Or_Universal (R))))
5496 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5498 if TL = Universal_Integer or else TR = Universal_Integer then
5499 Check_For_Visible_Operator (N, B_Typ);
5502 -- If context is a fixed type and one operand is integer, the other
5503 -- is resolved with the type of the context.
5505 if Is_Fixed_Point_Type (B_Typ)
5506 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5507 or else TL = Universal_Integer)
5512 elsif Is_Fixed_Point_Type (B_Typ)
5513 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5514 or else TR = Universal_Integer)
5519 -- If both operands are universal and the context is a floating
5520 -- point type, the operands are resolved to the type of the context.
5522 elsif Is_Floating_Point_Type (B_Typ) then
5527 Set_Mixed_Mode_Operand (L, TR);
5528 Set_Mixed_Mode_Operand (R, TL);
5531 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5532 -- multiplying operators from being used when the expected type is
5533 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5534 -- some cases where the expected type is actually Any_Real;
5535 -- Expected_Type_Is_Any_Real takes care of that case.
5537 if Etype (N) = Universal_Fixed
5538 or else Etype (N) = Any_Fixed
5540 if B_Typ = Universal_Fixed
5541 and then not Expected_Type_Is_Any_Real (N)
5542 and then not Nkind_In (Parent (N), N_Type_Conversion,
5543 N_Unchecked_Type_Conversion)
5545 Error_Msg_N ("type cannot be determined from context!", N);
5546 Error_Msg_N ("\explicit conversion to result type required", N);
5548 Set_Etype (L, Any_Type);
5549 Set_Etype (R, Any_Type);
5552 if Ada_Version = Ada_83
5553 and then Etype (N) = Universal_Fixed
5555 Nkind_In (Parent (N), N_Type_Conversion,
5556 N_Unchecked_Type_Conversion)
5559 ("(Ada 83) fixed-point operation needs explicit "
5563 -- The expected type is "any real type" in contexts like
5565 -- type T is delta <universal_fixed-expression> ...
5567 -- in which case we need to set the type to Universal_Real
5568 -- so that static expression evaluation will work properly.
5570 if Expected_Type_Is_Any_Real (N) then
5571 Set_Etype (N, Universal_Real);
5573 Set_Etype (N, B_Typ);
5577 elsif Is_Fixed_Point_Type (B_Typ)
5578 and then (Is_Integer_Or_Universal (L)
5579 or else Nkind (L) = N_Real_Literal
5580 or else Nkind (R) = N_Real_Literal
5581 or else Is_Integer_Or_Universal (R))
5583 Set_Etype (N, B_Typ);
5585 elsif Etype (N) = Any_Fixed then
5587 -- If no previous errors, this is only possible if one operand is
5588 -- overloaded and the context is universal. Resolve as such.
5590 Set_Etype (N, B_Typ);
5594 if (TL = Universal_Integer or else TL = Universal_Real)
5596 (TR = Universal_Integer or else TR = Universal_Real)
5598 Check_For_Visible_Operator (N, B_Typ);
5601 -- If the context is Universal_Fixed and the operands are also
5602 -- universal fixed, this is an error, unless there is only one
5603 -- applicable fixed_point type (usually Duration).
5605 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5606 T := Unique_Fixed_Point_Type (N);
5608 if T = Any_Type then
5621 -- If one of the arguments was resolved to a non-universal type.
5622 -- label the result of the operation itself with the same type.
5623 -- Do the same for the universal argument, if any.
5625 T := Intersect_Types (L, R);
5626 Set_Etype (N, Base_Type (T));
5627 Set_Operand_Type (L);
5628 Set_Operand_Type (R);
5631 Generate_Operator_Reference (N, Typ);
5632 Analyze_Dimension (N);
5633 Eval_Arithmetic_Op (N);
5635 -- In SPARK, a multiplication or division with operands of fixed point
5636 -- types must be qualified or explicitly converted to identify the
5639 if (Is_Fixed_Point_Type (Etype (L))
5640 or else Is_Fixed_Point_Type (Etype (R)))
5641 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5643 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5645 Check_SPARK_05_Restriction
5646 ("operation should be qualified or explicitly converted", N);
5649 -- Set overflow and division checking bit
5651 if Nkind (N) in N_Op then
5652 if not Overflow_Checks_Suppressed (Etype (N)) then
5653 Enable_Overflow_Check (N);
5656 -- Give warning if explicit division by zero
5658 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5659 and then not Division_Checks_Suppressed (Etype (N))
5661 Rop := Right_Opnd (N);
5663 if Compile_Time_Known_Value (Rop)
5664 and then ((Is_Integer_Type (Etype (Rop))
5665 and then Expr_Value (Rop) = Uint_0)
5667 (Is_Real_Type (Etype (Rop))
5668 and then Expr_Value_R (Rop) = Ureal_0))
5670 -- Specialize the warning message according to the operation.
5671 -- When SPARK_Mode is On, force a warning instead of an error
5672 -- in that case, as this likely corresponds to deactivated
5673 -- code. The following warnings are for the case
5678 -- For division, we have two cases, for float division
5679 -- of an unconstrained float type, on a machine where
5680 -- Machine_Overflows is false, we don't get an exception
5681 -- at run-time, but rather an infinity or Nan. The Nan
5682 -- case is pretty obscure, so just warn about infinities.
5684 if Is_Floating_Point_Type (Typ)
5685 and then not Is_Constrained (Typ)
5686 and then not Machine_Overflows_On_Target
5689 ("float division by zero, may generate "
5690 & "'+'/'- infinity??", Right_Opnd (N));
5692 -- For all other cases, we get a Constraint_Error
5695 Apply_Compile_Time_Constraint_Error
5696 (N, "division by zero??", CE_Divide_By_Zero,
5697 Loc => Sloc (Right_Opnd (N)),
5698 Warn => SPARK_Mode = On);
5702 Apply_Compile_Time_Constraint_Error
5703 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5704 Loc => Sloc (Right_Opnd (N)),
5705 Warn => SPARK_Mode = On);
5708 Apply_Compile_Time_Constraint_Error
5709 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5710 Loc => Sloc (Right_Opnd (N)),
5711 Warn => SPARK_Mode = On);
5713 -- Division by zero can only happen with division, rem,
5714 -- and mod operations.
5717 raise Program_Error;
5720 -- In GNATprove mode, we enable the division check so that
5721 -- GNATprove will issue a message if it cannot be proved.
5723 if GNATprove_Mode then
5724 Activate_Division_Check (N);
5727 -- Otherwise just set the flag to check at run time
5730 Activate_Division_Check (N);
5734 -- If Restriction No_Implicit_Conditionals is active, then it is
5735 -- violated if either operand can be negative for mod, or for rem
5736 -- if both operands can be negative.
5738 if Restriction_Check_Required (No_Implicit_Conditionals)
5739 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5748 -- Set if corresponding operand might be negative
5752 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5753 LNeg := (not OK) or else Lo < 0;
5756 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5757 RNeg := (not OK) or else Lo < 0;
5759 -- Check if we will be generating conditionals. There are two
5760 -- cases where that can happen, first for REM, the only case
5761 -- is largest negative integer mod -1, where the division can
5762 -- overflow, but we still have to give the right result. The
5763 -- front end generates a test for this annoying case. Here we
5764 -- just test if both operands can be negative (that's what the
5765 -- expander does, so we match its logic here).
5767 -- The second case is mod where either operand can be negative.
5768 -- In this case, the back end has to generate additional tests.
5770 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5772 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5774 Check_Restriction (No_Implicit_Conditionals, N);
5780 Check_Unset_Reference (L);
5781 Check_Unset_Reference (R);
5782 end Resolve_Arithmetic_Op;
5788 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5789 function Same_Or_Aliased_Subprograms
5791 E : Entity_Id) return Boolean;
5792 -- Returns True if the subprogram entity S is the same as E or else
5793 -- S is an alias of E.
5795 ---------------------------------
5796 -- Same_Or_Aliased_Subprograms --
5797 ---------------------------------
5799 function Same_Or_Aliased_Subprograms
5801 E : Entity_Id) return Boolean
5803 Subp_Alias : constant Entity_Id := Alias (S);
5805 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5806 end Same_Or_Aliased_Subprograms;
5810 Loc : constant Source_Ptr := Sloc (N);
5811 Subp : constant Node_Id := Name (N);
5812 Body_Id : Entity_Id;
5822 -- Start of processing for Resolve_Call
5825 -- Preserve relevant elaboration-related attributes of the context which
5826 -- are no longer available or very expensive to recompute once analysis,
5827 -- resolution, and expansion are over.
5829 Mark_Elaboration_Attributes
5835 -- The context imposes a unique interpretation with type Typ on a
5836 -- procedure or function call. Find the entity of the subprogram that
5837 -- yields the expected type, and propagate the corresponding formal
5838 -- constraints on the actuals. The caller has established that an
5839 -- interpretation exists, and emitted an error if not unique.
5841 -- First deal with the case of a call to an access-to-subprogram,
5842 -- dereference made explicit in Analyze_Call.
5844 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5845 if not Is_Overloaded (Subp) then
5846 Nam := Etype (Subp);
5849 -- Find the interpretation whose type (a subprogram type) has a
5850 -- return type that is compatible with the context. Analysis of
5851 -- the node has established that one exists.
5855 Get_First_Interp (Subp, I, It);
5856 while Present (It.Typ) loop
5857 if Covers (Typ, Etype (It.Typ)) then
5862 Get_Next_Interp (I, It);
5866 raise Program_Error;
5870 -- If the prefix is not an entity, then resolve it
5872 if not Is_Entity_Name (Subp) then
5873 Resolve (Subp, Nam);
5876 -- For an indirect call, we always invalidate checks, since we do not
5877 -- know whether the subprogram is local or global. Yes we could do
5878 -- better here, e.g. by knowing that there are no local subprograms,
5879 -- but it does not seem worth the effort. Similarly, we kill all
5880 -- knowledge of current constant values.
5882 Kill_Current_Values;
5884 -- If this is a procedure call which is really an entry call, do
5885 -- the conversion of the procedure call to an entry call. Protected
5886 -- operations use the same circuitry because the name in the call
5887 -- can be an arbitrary expression with special resolution rules.
5889 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5890 or else (Is_Entity_Name (Subp)
5891 and then Ekind_In (Entity (Subp), E_Entry, E_Entry_Family))
5893 Resolve_Entry_Call (N, Typ);
5895 if Legacy_Elaboration_Checks then
5896 Check_Elab_Call (N);
5899 -- Annotate the tree by creating a call marker in case the original
5900 -- call is transformed by expansion. The call marker is automatically
5901 -- saved for later examination by the ABE Processing phase.
5903 Build_Call_Marker (N);
5905 -- Kill checks and constant values, as above for indirect case
5906 -- Who knows what happens when another task is activated?
5908 Kill_Current_Values;
5911 -- Normal subprogram call with name established in Resolve
5913 elsif not (Is_Type (Entity (Subp))) then
5914 Nam := Entity (Subp);
5915 Set_Entity_With_Checks (Subp, Nam);
5917 -- Otherwise we must have the case of an overloaded call
5920 pragma Assert (Is_Overloaded (Subp));
5922 -- Initialize Nam to prevent warning (we know it will be assigned
5923 -- in the loop below, but the compiler does not know that).
5927 Get_First_Interp (Subp, I, It);
5928 while Present (It.Typ) loop
5929 if Covers (Typ, It.Typ) then
5931 Set_Entity_With_Checks (Subp, Nam);
5935 Get_Next_Interp (I, It);
5939 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5940 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5941 and then Nkind (Subp) /= N_Explicit_Dereference
5942 and then Present (Parameter_Associations (N))
5944 -- The prefix is a parameterless function call that returns an access
5945 -- to subprogram. If parameters are present in the current call, add
5946 -- add an explicit dereference. We use the base type here because
5947 -- within an instance these may be subtypes.
5949 -- The dereference is added either in Analyze_Call or here. Should
5950 -- be consolidated ???
5952 Set_Is_Overloaded (Subp, False);
5953 Set_Etype (Subp, Etype (Nam));
5954 Insert_Explicit_Dereference (Subp);
5955 Nam := Designated_Type (Etype (Nam));
5956 Resolve (Subp, Nam);
5959 -- Check that a call to Current_Task does not occur in an entry body
5961 if Is_RTE (Nam, RE_Current_Task) then
5970 -- Exclude calls that occur within the default of a formal
5971 -- parameter of the entry, since those are evaluated outside
5974 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5976 if Nkind (P) = N_Entry_Body
5977 or else (Nkind (P) = N_Subprogram_Body
5978 and then Is_Entry_Barrier_Function (P))
5981 Error_Msg_Warn := SPARK_Mode /= On;
5983 ("& should not be used in entry body (RM C.7(17))<<",
5985 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5987 Make_Raise_Program_Error (Loc,
5988 Reason => PE_Current_Task_In_Entry_Body));
5989 Set_Etype (N, Rtype);
5996 -- Check that a procedure call does not occur in the context of the
5997 -- entry call statement of a conditional or timed entry call. Note that
5998 -- the case of a call to a subprogram renaming of an entry will also be
5999 -- rejected. The test for N not being an N_Entry_Call_Statement is
6000 -- defensive, covering the possibility that the processing of entry
6001 -- calls might reach this point due to later modifications of the code
6004 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6005 and then Nkind (N) /= N_Entry_Call_Statement
6006 and then Entry_Call_Statement (Parent (N)) = N
6008 if Ada_Version < Ada_2005 then
6009 Error_Msg_N ("entry call required in select statement", N);
6011 -- Ada 2005 (AI-345): If a procedure_call_statement is used
6012 -- for a procedure_or_entry_call, the procedure_name or
6013 -- procedure_prefix of the procedure_call_statement shall denote
6014 -- an entry renamed by a procedure, or (a view of) a primitive
6015 -- subprogram of a limited interface whose first parameter is
6016 -- a controlling parameter.
6018 elsif Nkind (N) = N_Procedure_Call_Statement
6019 and then not Is_Renamed_Entry (Nam)
6020 and then not Is_Controlling_Limited_Procedure (Nam)
6023 ("entry call or dispatching primitive of interface required", N);
6027 -- If the SPARK_05 restriction is active, we are not allowed
6028 -- to have a call to a subprogram before we see its completion.
6030 if not Has_Completion (Nam)
6031 and then Restriction_Check_Required (SPARK_05)
6033 -- Don't flag strange internal calls
6035 and then Comes_From_Source (N)
6036 and then Comes_From_Source (Nam)
6038 -- Only flag calls in extended main source
6040 and then In_Extended_Main_Source_Unit (Nam)
6041 and then In_Extended_Main_Source_Unit (N)
6043 -- Exclude enumeration literals from this processing
6045 and then Ekind (Nam) /= E_Enumeration_Literal
6047 Check_SPARK_05_Restriction
6048 ("call to subprogram cannot appear before its body", N);
6051 -- Check that this is not a call to a protected procedure or entry from
6052 -- within a protected function.
6054 Check_Internal_Protected_Use (N, Nam);
6056 -- Freeze the subprogram name if not in a spec-expression. Note that
6057 -- we freeze procedure calls as well as function calls. Procedure calls
6058 -- are not frozen according to the rules (RM 13.14(14)) because it is
6059 -- impossible to have a procedure call to a non-frozen procedure in
6060 -- pure Ada, but in the code that we generate in the expander, this
6061 -- rule needs extending because we can generate procedure calls that
6064 -- In Ada 2012, expression functions may be called within pre/post
6065 -- conditions of subsequent functions or expression functions. Such
6066 -- calls do not freeze when they appear within generated bodies,
6067 -- (including the body of another expression function) which would
6068 -- place the freeze node in the wrong scope. An expression function
6069 -- is frozen in the usual fashion, by the appearance of a real body,
6070 -- or at the end of a declarative part. However an implcit call to
6071 -- an expression function may appear when it is part of a default
6072 -- expression in a call to an initialiation procedure, and must be
6073 -- frozen now, even if the body is inserted at a later point.
6075 if Is_Entity_Name (Subp)
6076 and then not In_Spec_Expression
6077 and then not Is_Expression_Function_Or_Completion (Current_Scope)
6079 (not Is_Expression_Function_Or_Completion (Entity (Subp))
6080 or else Scope (Entity (Subp)) = Current_Scope)
6082 if Is_Expression_Function (Entity (Subp)) then
6084 -- Force freeze of expression function in call.
6086 Set_Comes_From_Source (Subp, True);
6087 Set_Must_Not_Freeze (Subp, False);
6090 Freeze_Expression (Subp);
6093 -- For a predefined operator, the type of the result is the type imposed
6094 -- by context, except for a predefined operation on universal fixed.
6095 -- Otherwise The type of the call is the type returned by the subprogram
6098 if Is_Predefined_Op (Nam) then
6099 if Etype (N) /= Universal_Fixed then
6103 -- If the subprogram returns an array type, and the context requires the
6104 -- component type of that array type, the node is really an indexing of
6105 -- the parameterless call. Resolve as such. A pathological case occurs
6106 -- when the type of the component is an access to the array type. In
6107 -- this case the call is truly ambiguous. If the call is to an intrinsic
6108 -- subprogram, it can't be an indexed component. This check is necessary
6109 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
6110 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
6111 -- pointers to the same array), the compiler gets confused and does an
6112 -- infinite recursion.
6114 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
6116 ((Is_Array_Type (Etype (Nam))
6117 and then Covers (Typ, Component_Type (Etype (Nam))))
6119 (Is_Access_Type (Etype (Nam))
6120 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6122 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))
6123 and then not Is_Intrinsic_Subprogram (Entity (Subp))))
6126 Index_Node : Node_Id;
6128 Ret_Type : constant Entity_Id := Etype (Nam);
6131 if Is_Access_Type (Ret_Type)
6132 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
6135 ("cannot disambiguate function call and indexing", N);
6137 New_Subp := Relocate_Node (Subp);
6139 -- The called entity may be an explicit dereference, in which
6140 -- case there is no entity to set.
6142 if Nkind (New_Subp) /= N_Explicit_Dereference then
6143 Set_Entity (Subp, Nam);
6146 if (Is_Array_Type (Ret_Type)
6147 and then Component_Type (Ret_Type) /= Any_Type)
6149 (Is_Access_Type (Ret_Type)
6151 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
6153 if Needs_No_Actuals (Nam) then
6155 -- Indexed call to a parameterless function
6158 Make_Indexed_Component (Loc,
6160 Make_Function_Call (Loc, Name => New_Subp),
6161 Expressions => Parameter_Associations (N));
6163 -- An Ada 2005 prefixed call to a primitive operation
6164 -- whose first parameter is the prefix. This prefix was
6165 -- prepended to the parameter list, which is actually a
6166 -- list of indexes. Remove the prefix in order to build
6167 -- the proper indexed component.
6170 Make_Indexed_Component (Loc,
6172 Make_Function_Call (Loc,
6174 Parameter_Associations =>
6176 (Remove_Head (Parameter_Associations (N)))),
6177 Expressions => Parameter_Associations (N));
6180 -- Preserve the parenthesis count of the node
6182 Set_Paren_Count (Index_Node, Paren_Count (N));
6184 -- Since we are correcting a node classification error made
6185 -- by the parser, we call Replace rather than Rewrite.
6187 Replace (N, Index_Node);
6189 Set_Etype (Prefix (N), Ret_Type);
6191 Resolve_Indexed_Component (N, Typ);
6193 if Legacy_Elaboration_Checks then
6194 Check_Elab_Call (Prefix (N));
6197 -- Annotate the tree by creating a call marker in case
6198 -- the original call is transformed by expansion. The call
6199 -- marker is automatically saved for later examination by
6200 -- the ABE Processing phase.
6202 Build_Call_Marker (Prefix (N));
6210 -- If the called function is not declared in the main unit and it
6211 -- returns the limited view of type then use the available view (as
6212 -- is done in Try_Object_Operation) to prevent back-end confusion;
6213 -- for the function entity itself. The call must appear in a context
6214 -- where the nonlimited view is available. If the function entity is
6215 -- in the extended main unit then no action is needed, because the
6216 -- back end handles this case. In either case the type of the call
6217 -- is the nonlimited view.
6219 if From_Limited_With (Etype (Nam))
6220 and then Present (Available_View (Etype (Nam)))
6222 Set_Etype (N, Available_View (Etype (Nam)));
6224 if not In_Extended_Main_Code_Unit (Nam) then
6225 Set_Etype (Nam, Available_View (Etype (Nam)));
6229 Set_Etype (N, Etype (Nam));
6233 -- In the case where the call is to an overloaded subprogram, Analyze
6234 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6235 -- such a case Normalize_Actuals needs to be called once more to order
6236 -- the actuals correctly. Otherwise the call will have the ordering
6237 -- given by the last overloaded subprogram whether this is the correct
6238 -- one being called or not.
6240 if Is_Overloaded (Subp) then
6241 Normalize_Actuals (N, Nam, False, Norm_OK);
6242 pragma Assert (Norm_OK);
6245 -- In any case, call is fully resolved now. Reset Overload flag, to
6246 -- prevent subsequent overload resolution if node is analyzed again
6248 Set_Is_Overloaded (Subp, False);
6249 Set_Is_Overloaded (N, False);
6251 -- A Ghost entity must appear in a specific context
6253 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6254 Check_Ghost_Context (Nam, N);
6257 -- If we are calling the current subprogram from immediately within its
6258 -- body, then that is the case where we can sometimes detect cases of
6259 -- infinite recursion statically. Do not try this in case restriction
6260 -- No_Recursion is in effect anyway, and do it only for source calls.
6262 if Comes_From_Source (N) then
6263 Scop := Current_Scope;
6265 -- Check violation of SPARK_05 restriction which does not permit
6266 -- a subprogram body to contain a call to the subprogram directly.
6268 if Restriction_Check_Required (SPARK_05)
6269 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6271 Check_SPARK_05_Restriction
6272 ("subprogram may not contain direct call to itself", N);
6275 -- Issue warning for possible infinite recursion in the absence
6276 -- of the No_Recursion restriction.
6278 if Same_Or_Aliased_Subprograms (Nam, Scop)
6279 and then not Restriction_Active (No_Recursion)
6280 and then Check_Infinite_Recursion (N)
6282 -- Here we detected and flagged an infinite recursion, so we do
6283 -- not need to test the case below for further warnings. Also we
6284 -- are all done if we now have a raise SE node.
6286 if Nkind (N) = N_Raise_Storage_Error then
6290 -- If call is to immediately containing subprogram, then check for
6291 -- the case of a possible run-time detectable infinite recursion.
6294 Scope_Loop : while Scop /= Standard_Standard loop
6295 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6297 -- Although in general case, recursion is not statically
6298 -- checkable, the case of calling an immediately containing
6299 -- subprogram is easy to catch.
6301 Check_Restriction (No_Recursion, N);
6303 -- If the recursive call is to a parameterless subprogram,
6304 -- then even if we can't statically detect infinite
6305 -- recursion, this is pretty suspicious, and we output a
6306 -- warning. Furthermore, we will try later to detect some
6307 -- cases here at run time by expanding checking code (see
6308 -- Detect_Infinite_Recursion in package Exp_Ch6).
6310 -- If the recursive call is within a handler, do not emit a
6311 -- warning, because this is a common idiom: loop until input
6312 -- is correct, catch illegal input in handler and restart.
6314 if No (First_Formal (Nam))
6315 and then Etype (Nam) = Standard_Void_Type
6316 and then not Error_Posted (N)
6317 and then Nkind (Parent (N)) /= N_Exception_Handler
6319 -- For the case of a procedure call. We give the message
6320 -- only if the call is the first statement in a sequence
6321 -- of statements, or if all previous statements are
6322 -- simple assignments. This is simply a heuristic to
6323 -- decrease false positives, without losing too many good
6324 -- warnings. The idea is that these previous statements
6325 -- may affect global variables the procedure depends on.
6326 -- We also exclude raise statements, that may arise from
6327 -- constraint checks and are probably unrelated to the
6328 -- intended control flow.
6330 if Nkind (N) = N_Procedure_Call_Statement
6331 and then Is_List_Member (N)
6337 while Present (P) loop
6338 if not Nkind_In (P, N_Assignment_Statement,
6339 N_Raise_Constraint_Error)
6349 -- Do not give warning if we are in a conditional context
6352 K : constant Node_Kind := Nkind (Parent (N));
6354 if (K = N_Loop_Statement
6355 and then Present (Iteration_Scheme (Parent (N))))
6356 or else K = N_If_Statement
6357 or else K = N_Elsif_Part
6358 or else K = N_Case_Statement_Alternative
6364 -- Here warning is to be issued
6366 Set_Has_Recursive_Call (Nam);
6367 Error_Msg_Warn := SPARK_Mode /= On;
6368 Error_Msg_N ("possible infinite recursion<<!", N);
6369 Error_Msg_N ("\Storage_Error ]<<!", N);
6375 Scop := Scope (Scop);
6376 end loop Scope_Loop;
6380 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6382 Check_Obsolescent_2005_Entity (Nam, Subp);
6384 -- If subprogram name is a predefined operator, it was given in
6385 -- functional notation. Replace call node with operator node, so
6386 -- that actuals can be resolved appropriately.
6388 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6389 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6392 elsif Present (Alias (Nam))
6393 and then Is_Predefined_Op (Alias (Nam))
6395 Resolve_Actuals (N, Nam);
6396 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6400 -- Create a transient scope if the resulting type requires it
6402 -- There are several notable exceptions:
6404 -- a) In init procs, the transient scope overhead is not needed, and is
6405 -- even incorrect when the call is a nested initialization call for a
6406 -- component whose expansion may generate adjust calls. However, if the
6407 -- call is some other procedure call within an initialization procedure
6408 -- (for example a call to Create_Task in the init_proc of the task
6409 -- run-time record) a transient scope must be created around this call.
6411 -- b) Enumeration literal pseudo-calls need no transient scope
6413 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6414 -- functions) do not use the secondary stack even though the return
6415 -- type may be unconstrained.
6417 -- d) Calls to a build-in-place function, since such functions may
6418 -- allocate their result directly in a target object, and cases where
6419 -- the result does get allocated in the secondary stack are checked for
6420 -- within the specialized Exp_Ch6 procedures for expanding those
6421 -- build-in-place calls.
6423 -- e) Calls to inlinable expression functions do not use the secondary
6424 -- stack (since the call will be replaced by its returned object).
6426 -- f) If the subprogram is marked Inline_Always, then even if it returns
6427 -- an unconstrained type the call does not require use of the secondary
6428 -- stack. However, inlining will only take place if the body to inline
6429 -- is already present. It may not be available if e.g. the subprogram is
6430 -- declared in a child instance.
6433 and then Has_Pragma_Inline (Nam)
6434 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6435 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6439 elsif Ekind (Nam) = E_Enumeration_Literal
6440 or else Is_Build_In_Place_Function (Nam)
6441 or else Is_Intrinsic_Subprogram (Nam)
6442 or else Is_Inlinable_Expression_Function (Nam)
6446 elsif Expander_Active
6447 and then Ekind_In (Nam, E_Function, E_Subprogram_Type)
6448 and then Requires_Transient_Scope (Etype (Nam))
6450 Establish_Transient_Scope (N, Manage_Sec_Stack => True);
6452 -- If the call appears within the bounds of a loop, it will be
6453 -- rewritten and reanalyzed, nothing left to do here.
6455 if Nkind (N) /= N_Function_Call then
6460 -- A protected function cannot be called within the definition of the
6461 -- enclosing protected type, unless it is part of a pre/postcondition
6462 -- on another protected operation. This may appear in the entry wrapper
6463 -- created for an entry with preconditions.
6465 if Is_Protected_Type (Scope (Nam))
6466 and then In_Open_Scopes (Scope (Nam))
6467 and then not Has_Completion (Scope (Nam))
6468 and then not In_Spec_Expression
6469 and then not Is_Entry_Wrapper (Current_Scope)
6472 ("& cannot be called before end of protected definition", N, Nam);
6475 -- Propagate interpretation to actuals, and add default expressions
6478 if Present (First_Formal (Nam)) then
6479 Resolve_Actuals (N, Nam);
6481 -- Overloaded literals are rewritten as function calls, for purpose of
6482 -- resolution. After resolution, we can replace the call with the
6485 elsif Ekind (Nam) = E_Enumeration_Literal then
6486 Copy_Node (Subp, N);
6487 Resolve_Entity_Name (N, Typ);
6489 -- Avoid validation, since it is a static function call
6491 Generate_Reference (Nam, Subp);
6495 -- If the subprogram is not global, then kill all saved values and
6496 -- checks. This is a bit conservative, since in many cases we could do
6497 -- better, but it is not worth the effort. Similarly, we kill constant
6498 -- values. However we do not need to do this for internal entities
6499 -- (unless they are inherited user-defined subprograms), since they
6500 -- are not in the business of molesting local values.
6502 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6503 -- kill all checks and values for calls to global subprograms. This
6504 -- takes care of the case where an access to a local subprogram is
6505 -- taken, and could be passed directly or indirectly and then called
6506 -- from almost any context.
6508 -- Note: we do not do this step till after resolving the actuals. That
6509 -- way we still take advantage of the current value information while
6510 -- scanning the actuals.
6512 -- We suppress killing values if we are processing the nodes associated
6513 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6514 -- type kills all the values as part of analyzing the code that
6515 -- initializes the dispatch tables.
6517 if Inside_Freezing_Actions = 0
6518 and then (not Is_Library_Level_Entity (Nam)
6519 or else Suppress_Value_Tracking_On_Call
6520 (Nearest_Dynamic_Scope (Current_Scope)))
6521 and then (Comes_From_Source (Nam)
6522 or else (Present (Alias (Nam))
6523 and then Comes_From_Source (Alias (Nam))))
6525 Kill_Current_Values;
6528 -- If we are warning about unread OUT parameters, this is the place to
6529 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6530 -- after the above call to Kill_Current_Values (since that call clears
6531 -- the Last_Assignment field of all local variables).
6533 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6534 and then Comes_From_Source (N)
6535 and then In_Extended_Main_Source_Unit (N)
6542 F := First_Formal (Nam);
6543 A := First_Actual (N);
6544 while Present (F) and then Present (A) loop
6545 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6546 and then Warn_On_Modified_As_Out_Parameter (F)
6547 and then Is_Entity_Name (A)
6548 and then Present (Entity (A))
6549 and then Comes_From_Source (N)
6550 and then Safe_To_Capture_Value (N, Entity (A))
6552 Set_Last_Assignment (Entity (A), A);
6561 -- If the subprogram is a primitive operation, check whether or not
6562 -- it is a correct dispatching call.
6564 if Is_Overloadable (Nam)
6565 and then Is_Dispatching_Operation (Nam)
6567 Check_Dispatching_Call (N);
6569 elsif Ekind (Nam) /= E_Subprogram_Type
6570 and then Is_Abstract_Subprogram (Nam)
6571 and then not In_Instance
6573 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6576 -- If this is a dispatching call, generate the appropriate reference,
6577 -- for better source navigation in GPS.
6579 if Is_Overloadable (Nam)
6580 and then Present (Controlling_Argument (N))
6582 Generate_Reference (Nam, Subp, 'R');
6584 -- Normal case, not a dispatching call: generate a call reference
6587 Generate_Reference (Nam, Subp, 's');
6590 if Is_Intrinsic_Subprogram (Nam) then
6591 Check_Intrinsic_Call (N);
6594 -- Check for violation of restriction No_Specific_Termination_Handlers
6595 -- and warn on a potentially blocking call to Abort_Task.
6597 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6598 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6600 Is_RTE (Nam, RE_Specific_Handler))
6602 Check_Restriction (No_Specific_Termination_Handlers, N);
6604 elsif Is_RTE (Nam, RE_Abort_Task) then
6605 Check_Potentially_Blocking_Operation (N);
6608 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6609 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6610 -- need to check the second argument to determine whether it is an
6611 -- absolute or relative timing event.
6613 if Restriction_Check_Required (No_Relative_Delay)
6614 and then Is_RTE (Nam, RE_Set_Handler)
6615 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6617 Check_Restriction (No_Relative_Delay, N);
6620 -- Issue an error for a call to an eliminated subprogram. This routine
6621 -- will not perform the check if the call appears within a default
6624 Check_For_Eliminated_Subprogram (Subp, Nam);
6626 -- In formal mode, the primitive operations of a tagged type or type
6627 -- extension do not include functions that return the tagged type.
6629 if Nkind (N) = N_Function_Call
6630 and then Is_Tagged_Type (Etype (N))
6631 and then Is_Entity_Name (Name (N))
6632 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6634 Check_SPARK_05_Restriction ("function not inherited", N);
6637 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6638 -- class-wide and the call dispatches on result in a context that does
6639 -- not provide a tag, the call raises Program_Error.
6641 if Nkind (N) = N_Function_Call
6642 and then In_Instance
6643 and then Is_Generic_Actual_Type (Typ)
6644 and then Is_Class_Wide_Type (Typ)
6645 and then Has_Controlling_Result (Nam)
6646 and then Nkind (Parent (N)) = N_Object_Declaration
6648 -- Verify that none of the formals are controlling
6651 Call_OK : Boolean := False;
6655 F := First_Formal (Nam);
6656 while Present (F) loop
6657 if Is_Controlling_Formal (F) then
6666 Error_Msg_Warn := SPARK_Mode /= On;
6667 Error_Msg_N ("!cannot determine tag of result<<", N);
6668 Error_Msg_N ("\Program_Error [<<!", N);
6670 Make_Raise_Program_Error (Sloc (N),
6671 Reason => PE_Explicit_Raise));
6676 -- Check for calling a function with OUT or IN OUT parameter when the
6677 -- calling context (us right now) is not Ada 2012, so does not allow
6678 -- OUT or IN OUT parameters in function calls. Functions declared in
6679 -- a predefined unit are OK, as they may be called indirectly from a
6680 -- user-declared instantiation.
6682 if Ada_Version < Ada_2012
6683 and then Ekind (Nam) = E_Function
6684 and then Has_Out_Or_In_Out_Parameter (Nam)
6685 and then not In_Predefined_Unit (Nam)
6687 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6688 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6691 -- Check the dimensions of the actuals in the call. For function calls,
6692 -- propagate the dimensions from the returned type to N.
6694 Analyze_Dimension_Call (N, Nam);
6696 -- All done, evaluate call and deal with elaboration issues
6700 if Legacy_Elaboration_Checks then
6701 Check_Elab_Call (N);
6704 -- Annotate the tree by creating a call marker in case the original call
6705 -- is transformed by expansion. The call marker is automatically saved
6706 -- for later examination by the ABE Processing phase.
6708 Build_Call_Marker (N);
6710 -- In GNATprove mode, expansion is disabled, but we want to inline some
6711 -- subprograms to facilitate formal verification. Indirect calls through
6712 -- a subprogram type or within a generic cannot be inlined. Inlining is
6713 -- performed only for calls subject to SPARK_Mode on.
6716 and then SPARK_Mode = On
6717 and then Is_Overloadable (Nam)
6718 and then not Inside_A_Generic
6720 Nam_UA := Ultimate_Alias (Nam);
6721 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6723 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6724 Body_Id := Corresponding_Body (Nam_Decl);
6726 -- Nothing to do if the subprogram is not eligible for inlining in
6727 -- GNATprove mode, or inlining is disabled with switch -gnatdm
6729 if not Is_Inlined_Always (Nam_UA)
6730 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6731 or else Debug_Flag_M
6735 -- Calls cannot be inlined inside assertions, as GNATprove treats
6736 -- assertions as logic expressions. Only issue a message when the
6737 -- body has been seen, otherwise this leads to spurious messages
6738 -- on expression functions.
6740 elsif In_Assertion_Expr /= 0 then
6741 if Present (Body_Id) then
6743 ("cannot inline & (in assertion expression)?", N, Nam_UA);
6746 -- Calls cannot be inlined inside default expressions
6748 elsif In_Default_Expr then
6750 ("cannot inline & (in default expression)?", N, Nam_UA);
6752 -- Inlining should not be performed during preanalysis
6754 elsif Full_Analysis then
6756 -- Do not inline calls inside expression functions or functions
6757 -- generated by the front end for subtype predicates, as this
6758 -- would prevent interpreting them as logical formulas in
6759 -- GNATprove. Only issue a message when the body has been seen,
6760 -- otherwise this leads to spurious messages on callees that
6761 -- are themselves expression functions.
6763 if Present (Current_Subprogram)
6765 (Is_Expression_Function_Or_Completion (Current_Subprogram)
6766 or else Is_Predicate_Function (Current_Subprogram)
6767 or else Is_Invariant_Procedure (Current_Subprogram)
6768 or else Is_DIC_Procedure (Current_Subprogram))
6770 if Present (Body_Id)
6771 and then Present (Body_To_Inline (Nam_Decl))
6773 if Is_Predicate_Function (Current_Subprogram) then
6775 ("cannot inline & (inside predicate)?",
6778 elsif Is_Invariant_Procedure (Current_Subprogram) then
6780 ("cannot inline & (inside invariant)?",
6783 elsif Is_DIC_Procedure (Current_Subprogram) then
6785 ("cannot inline & (inside Default_Initial_Condition)?",
6790 ("cannot inline & (inside expression function)?",
6795 -- With the one-pass inlining technique, a call cannot be
6796 -- inlined if the corresponding body has not been seen yet.
6798 elsif No (Body_Id) then
6800 ("cannot inline & (body not seen yet)?", N, Nam_UA);
6802 -- Nothing to do if there is no body to inline, indicating that
6803 -- the subprogram is not suitable for inlining in GNATprove
6806 elsif No (Body_To_Inline (Nam_Decl)) then
6809 -- Calls cannot be inlined inside potentially unevaluated
6810 -- expressions, as this would create complex actions inside
6811 -- expressions, that are not handled by GNATprove.
6813 elsif Is_Potentially_Unevaluated (N) then
6815 ("cannot inline & (in potentially unevaluated context)?",
6818 -- Do not inline calls which would possibly lead to missing a
6819 -- type conversion check on an input parameter.
6821 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode (N, Nam) then
6823 ("cannot inline & (possible check on input parameters)?",
6826 -- Otherwise, inline the call
6829 Expand_Inlined_Call (N, Nam_UA, Nam);
6835 Mark_Use_Clauses (Subp);
6837 Warn_On_Overlapping_Actuals (Nam, N);
6840 -----------------------------
6841 -- Resolve_Case_Expression --
6842 -----------------------------
6844 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6847 Alt_Typ : Entity_Id;
6851 Alt := First (Alternatives (N));
6852 while Present (Alt) loop
6853 Alt_Expr := Expression (Alt);
6855 if Error_Posted (Alt_Expr) then
6859 Resolve (Alt_Expr, Typ);
6860 Alt_Typ := Etype (Alt_Expr);
6862 -- When the expression is of a scalar subtype different from the
6863 -- result subtype, then insert a conversion to ensure the generation
6864 -- of a constraint check.
6866 if Is_Scalar_Type (Alt_Typ) and then Alt_Typ /= Typ then
6867 Rewrite (Alt_Expr, Convert_To (Typ, Alt_Expr));
6868 Analyze_And_Resolve (Alt_Expr, Typ);
6874 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6875 -- dynamically tagged must be known statically.
6877 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
6878 Alt := First (Alternatives (N));
6879 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
6881 while Present (Alt) loop
6882 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
6884 ("all or none of the dependent expressions can be "
6885 & "dynamically tagged", N);
6893 Eval_Case_Expression (N);
6894 Analyze_Dimension (N);
6895 end Resolve_Case_Expression;
6897 -------------------------------
6898 -- Resolve_Character_Literal --
6899 -------------------------------
6901 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6902 B_Typ : constant Entity_Id := Base_Type (Typ);
6906 -- Verify that the character does belong to the type of the context
6908 Set_Etype (N, B_Typ);
6909 Eval_Character_Literal (N);
6911 -- Wide_Wide_Character literals must always be defined, since the set
6912 -- of wide wide character literals is complete, i.e. if a character
6913 -- literal is accepted by the parser, then it is OK for wide wide
6914 -- character (out of range character literals are rejected).
6916 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6919 -- Always accept character literal for type Any_Character, which
6920 -- occurs in error situations and in comparisons of literals, both
6921 -- of which should accept all literals.
6923 elsif B_Typ = Any_Character then
6926 -- For Standard.Character or a type derived from it, check that the
6927 -- literal is in range.
6929 elsif Root_Type (B_Typ) = Standard_Character then
6930 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6934 -- For Standard.Wide_Character or a type derived from it, check that the
6935 -- literal is in range.
6937 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6938 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6942 -- If the entity is already set, this has already been resolved in a
6943 -- generic context, or comes from expansion. Nothing else to do.
6945 elsif Present (Entity (N)) then
6948 -- Otherwise we have a user defined character type, and we can use the
6949 -- standard visibility mechanisms to locate the referenced entity.
6952 C := Current_Entity (N);
6953 while Present (C) loop
6954 if Etype (C) = B_Typ then
6955 Set_Entity_With_Checks (N, C);
6956 Generate_Reference (C, N);
6964 -- If we fall through, then the literal does not match any of the
6965 -- entries of the enumeration type. This isn't just a constraint error
6966 -- situation, it is an illegality (see RM 4.2).
6969 ("character not defined for }", N, First_Subtype (B_Typ));
6970 end Resolve_Character_Literal;
6972 ---------------------------
6973 -- Resolve_Comparison_Op --
6974 ---------------------------
6976 -- Context requires a boolean type, and plays no role in resolution.
6977 -- Processing identical to that for equality operators. The result type is
6978 -- the base type, which matters when pathological subtypes of booleans with
6979 -- limited ranges are used.
6981 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6982 L : constant Node_Id := Left_Opnd (N);
6983 R : constant Node_Id := Right_Opnd (N);
6987 -- If this is an intrinsic operation which is not predefined, use the
6988 -- types of its declared arguments to resolve the possibly overloaded
6989 -- operands. Otherwise the operands are unambiguous and specify the
6992 if Scope (Entity (N)) /= Standard_Standard then
6993 T := Etype (First_Entity (Entity (N)));
6996 T := Find_Unique_Type (L, R);
6998 if T = Any_Fixed then
6999 T := Unique_Fixed_Point_Type (L);
7003 Set_Etype (N, Base_Type (Typ));
7004 Generate_Reference (T, N, ' ');
7006 -- Skip remaining processing if already set to Any_Type
7008 if T = Any_Type then
7012 -- Deal with other error cases
7014 if T = Any_String or else
7015 T = Any_Composite or else
7018 if T = Any_Character then
7019 Ambiguous_Character (L);
7021 Error_Msg_N ("ambiguous operands for comparison", N);
7024 Set_Etype (N, Any_Type);
7028 -- Resolve the operands if types OK
7032 Check_Unset_Reference (L);
7033 Check_Unset_Reference (R);
7034 Generate_Operator_Reference (N, T);
7035 Check_Low_Bound_Tested (N);
7037 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
7038 -- types or array types except String.
7040 if Is_Boolean_Type (T) then
7041 Check_SPARK_05_Restriction
7042 ("comparison is not defined on Boolean type", N);
7044 elsif Is_Array_Type (T)
7045 and then Base_Type (T) /= Standard_String
7047 Check_SPARK_05_Restriction
7048 ("comparison is not defined on array types other than String", N);
7051 -- Check comparison on unordered enumeration
7053 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
7054 Error_Msg_Sloc := Sloc (Etype (L));
7056 ("comparison on unordered enumeration type& declared#?U?",
7060 Analyze_Dimension (N);
7062 -- Evaluate the relation (note we do this after the above check since
7063 -- this Eval call may change N to True/False. Skip this evaluation
7064 -- inside assertions, in order to keep assertions as written by users
7065 -- for tools that rely on these, e.g. GNATprove for loop invariants.
7066 -- Except evaluation is still performed even inside assertions for
7067 -- comparisons between values of universal type, which are useless
7068 -- for static analysis tools, and not supported even by GNATprove.
7070 if In_Assertion_Expr = 0
7071 or else (Is_Universal_Numeric_Type (Etype (L))
7073 Is_Universal_Numeric_Type (Etype (R)))
7075 Eval_Relational_Op (N);
7077 end Resolve_Comparison_Op;
7079 -----------------------------------------
7080 -- Resolve_Discrete_Subtype_Indication --
7081 -----------------------------------------
7083 procedure Resolve_Discrete_Subtype_Indication
7091 Analyze (Subtype_Mark (N));
7092 S := Entity (Subtype_Mark (N));
7094 if Nkind (Constraint (N)) /= N_Range_Constraint then
7095 Error_Msg_N ("expect range constraint for discrete type", N);
7096 Set_Etype (N, Any_Type);
7099 R := Range_Expression (Constraint (N));
7107 if Base_Type (S) /= Base_Type (Typ) then
7109 ("expect subtype of }", N, First_Subtype (Typ));
7111 -- Rewrite the constraint as a range of Typ
7112 -- to allow compilation to proceed further.
7115 Rewrite (Low_Bound (R),
7116 Make_Attribute_Reference (Sloc (Low_Bound (R)),
7117 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
7118 Attribute_Name => Name_First));
7119 Rewrite (High_Bound (R),
7120 Make_Attribute_Reference (Sloc (High_Bound (R)),
7121 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
7122 Attribute_Name => Name_First));
7126 Set_Etype (N, Etype (R));
7128 -- Additionally, we must check that the bounds are compatible
7129 -- with the given subtype, which might be different from the
7130 -- type of the context.
7132 Apply_Range_Check (R, S);
7134 -- ??? If the above check statically detects a Constraint_Error
7135 -- it replaces the offending bound(s) of the range R with a
7136 -- Constraint_Error node. When the itype which uses these bounds
7137 -- is frozen the resulting call to Duplicate_Subexpr generates
7138 -- a new temporary for the bounds.
7140 -- Unfortunately there are other itypes that are also made depend
7141 -- on these bounds, so when Duplicate_Subexpr is called they get
7142 -- a forward reference to the newly created temporaries and Gigi
7143 -- aborts on such forward references. This is probably sign of a
7144 -- more fundamental problem somewhere else in either the order of
7145 -- itype freezing or the way certain itypes are constructed.
7147 -- To get around this problem we call Remove_Side_Effects right
7148 -- away if either bounds of R are a Constraint_Error.
7151 L : constant Node_Id := Low_Bound (R);
7152 H : constant Node_Id := High_Bound (R);
7155 if Nkind (L) = N_Raise_Constraint_Error then
7156 Remove_Side_Effects (L);
7159 if Nkind (H) = N_Raise_Constraint_Error then
7160 Remove_Side_Effects (H);
7164 Check_Unset_Reference (Low_Bound (R));
7165 Check_Unset_Reference (High_Bound (R));
7168 end Resolve_Discrete_Subtype_Indication;
7170 -------------------------
7171 -- Resolve_Entity_Name --
7172 -------------------------
7174 -- Used to resolve identifiers and expanded names
7176 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
7177 function Is_Assignment_Or_Object_Expression
7179 Expr : Node_Id) return Boolean;
7180 -- Determine whether node Context denotes an assignment statement or an
7181 -- object declaration whose expression is node Expr.
7183 ----------------------------------------
7184 -- Is_Assignment_Or_Object_Expression --
7185 ----------------------------------------
7187 function Is_Assignment_Or_Object_Expression
7189 Expr : Node_Id) return Boolean
7192 if Nkind_In (Context, N_Assignment_Statement,
7193 N_Object_Declaration)
7194 and then Expression (Context) = Expr
7198 -- Check whether a construct that yields a name is the expression of
7199 -- an assignment statement or an object declaration.
7201 elsif (Nkind_In (Context, N_Attribute_Reference,
7202 N_Explicit_Dereference,
7203 N_Indexed_Component,
7204 N_Selected_Component,
7206 and then Prefix (Context) = Expr)
7208 (Nkind_In (Context, N_Type_Conversion,
7209 N_Unchecked_Type_Conversion)
7210 and then Expression (Context) = Expr)
7213 Is_Assignment_Or_Object_Expression
7214 (Context => Parent (Context),
7217 -- Otherwise the context is not an assignment statement or an object
7223 end Is_Assignment_Or_Object_Expression;
7227 E : constant Entity_Id := Entity (N);
7230 -- Start of processing for Resolve_Entity_Name
7233 -- If garbage from errors, set to Any_Type and return
7235 if No (E) and then Total_Errors_Detected /= 0 then
7236 Set_Etype (N, Any_Type);
7240 -- Replace named numbers by corresponding literals. Note that this is
7241 -- the one case where Resolve_Entity_Name must reset the Etype, since
7242 -- it is currently marked as universal.
7244 if Ekind (E) = E_Named_Integer then
7246 Eval_Named_Integer (N);
7248 elsif Ekind (E) = E_Named_Real then
7250 Eval_Named_Real (N);
7252 -- For enumeration literals, we need to make sure that a proper style
7253 -- check is done, since such literals are overloaded, and thus we did
7254 -- not do a style check during the first phase of analysis.
7256 elsif Ekind (E) = E_Enumeration_Literal then
7257 Set_Entity_With_Checks (N, E);
7258 Eval_Entity_Name (N);
7260 -- Case of (sub)type name appearing in a context where an expression
7261 -- is expected. This is legal if occurrence is a current instance.
7262 -- See RM 8.6 (17/3).
7264 elsif Is_Type (E) then
7265 if Is_Current_Instance (N) then
7268 -- Any other use is an error
7272 ("invalid use of subtype mark in expression or call", N);
7275 -- Check discriminant use if entity is discriminant in current scope,
7276 -- i.e. discriminant of record or concurrent type currently being
7277 -- analyzed. Uses in corresponding body are unrestricted.
7279 elsif Ekind (E) = E_Discriminant
7280 and then Scope (E) = Current_Scope
7281 and then not Has_Completion (Current_Scope)
7283 Check_Discriminant_Use (N);
7285 -- A parameterless generic function cannot appear in a context that
7286 -- requires resolution.
7288 elsif Ekind (E) = E_Generic_Function then
7289 Error_Msg_N ("illegal use of generic function", N);
7291 -- In Ada 83 an OUT parameter cannot be read, but attributes of
7292 -- array types (i.e. bounds and length) are legal.
7294 elsif Ekind (E) = E_Out_Parameter
7295 and then (Nkind (Parent (N)) /= N_Attribute_Reference
7296 or else Is_Scalar_Type (Etype (E)))
7298 and then (Nkind (Parent (N)) in N_Op
7299 or else Nkind (Parent (N)) = N_Explicit_Dereference
7300 or else Is_Assignment_Or_Object_Expression
7301 (Context => Parent (N),
7304 if Ada_Version = Ada_83 then
7305 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7308 -- In all other cases, just do the possible static evaluation
7311 -- A deferred constant that appears in an expression must have a
7312 -- completion, unless it has been removed by in-place expansion of
7313 -- an aggregate. A constant that is a renaming does not need
7316 if Ekind (E) = E_Constant
7317 and then Comes_From_Source (E)
7318 and then No (Constant_Value (E))
7319 and then Is_Frozen (Etype (E))
7320 and then not In_Spec_Expression
7321 and then not Is_Imported (E)
7322 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7324 if No_Initialization (Parent (E))
7325 or else (Present (Full_View (E))
7326 and then No_Initialization (Parent (Full_View (E))))
7331 ("deferred constant is frozen before completion", N);
7335 Eval_Entity_Name (N);
7340 -- When the entity appears in a parameter association, retrieve the
7341 -- related subprogram call.
7343 if Nkind (Par) = N_Parameter_Association then
7344 Par := Parent (Par);
7347 if Comes_From_Source (N) then
7349 -- The following checks are only relevant when SPARK_Mode is on as
7350 -- they are not standard Ada legality rules.
7352 if SPARK_Mode = On then
7354 -- An effectively volatile object subject to enabled properties
7355 -- Async_Writers or Effective_Reads must appear in non-interfering
7356 -- context (SPARK RM 7.1.3(12)).
7359 and then Is_Effectively_Volatile (E)
7360 and then (Async_Writers_Enabled (E)
7361 or else Effective_Reads_Enabled (E))
7362 and then not Is_OK_Volatile_Context (Par, N)
7365 ("volatile object cannot appear in this context "
7366 & "(SPARK RM 7.1.3(12))", N);
7369 -- Check for possible elaboration issues with respect to reads of
7370 -- variables. The act of renaming the variable is not considered a
7371 -- read as it simply establishes an alias.
7373 if Legacy_Elaboration_Checks
7374 and then Ekind (E) = E_Variable
7375 and then Dynamic_Elaboration_Checks
7376 and then Nkind (Par) /= N_Object_Renaming_Declaration
7378 Check_Elab_Call (N);
7382 -- The variable may eventually become a constituent of a single
7383 -- protected/task type. Record the reference now and verify its
7384 -- legality when analyzing the contract of the variable
7387 if Ekind (E) = E_Variable then
7388 Record_Possible_Part_Of_Reference (E, N);
7391 -- A Ghost entity must appear in a specific context
7393 if Is_Ghost_Entity (E) then
7394 Check_Ghost_Context (E, N);
7398 -- We may be resolving an entity within expanded code, so a reference to
7399 -- an entity should be ignored when calculating effective use clauses to
7400 -- avoid inappropriate marking.
7402 if Comes_From_Source (N) then
7403 Mark_Use_Clauses (E);
7405 end Resolve_Entity_Name;
7411 procedure Resolve_Entry (Entry_Name : Node_Id) is
7412 Loc : constant Source_Ptr := Sloc (Entry_Name);
7420 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7421 -- If the bounds of the entry family being called depend on task
7422 -- discriminants, build a new index subtype where a discriminant is
7423 -- replaced with the value of the discriminant of the target task.
7424 -- The target task is the prefix of the entry name in the call.
7426 -----------------------
7427 -- Actual_Index_Type --
7428 -----------------------
7430 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7431 Typ : constant Entity_Id := Entry_Index_Type (E);
7432 Tsk : constant Entity_Id := Scope (E);
7433 Lo : constant Node_Id := Type_Low_Bound (Typ);
7434 Hi : constant Node_Id := Type_High_Bound (Typ);
7437 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7438 -- If the bound is given by a discriminant, replace with a reference
7439 -- to the discriminant of the same name in the target task. If the
7440 -- entry name is the target of a requeue statement and the entry is
7441 -- in the current protected object, the bound to be used is the
7442 -- discriminal of the object (see Apply_Range_Checks for details of
7443 -- the transformation).
7445 -----------------------------
7446 -- Actual_Discriminant_Ref --
7447 -----------------------------
7449 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7450 Typ : constant Entity_Id := Etype (Bound);
7454 Remove_Side_Effects (Bound);
7456 if not Is_Entity_Name (Bound)
7457 or else Ekind (Entity (Bound)) /= E_Discriminant
7461 elsif Is_Protected_Type (Tsk)
7462 and then In_Open_Scopes (Tsk)
7463 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7465 -- Note: here Bound denotes a discriminant of the corresponding
7466 -- record type tskV, whose discriminal is a formal of the
7467 -- init-proc tskVIP. What we want is the body discriminal,
7468 -- which is associated to the discriminant of the original
7469 -- concurrent type tsk.
7471 return New_Occurrence_Of
7472 (Find_Body_Discriminal (Entity (Bound)), Loc);
7476 Make_Selected_Component (Loc,
7477 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7478 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7483 end Actual_Discriminant_Ref;
7485 -- Start of processing for Actual_Index_Type
7488 if not Has_Discriminants (Tsk)
7489 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7491 return Entry_Index_Type (E);
7494 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7495 Set_Etype (New_T, Base_Type (Typ));
7496 Set_Size_Info (New_T, Typ);
7497 Set_RM_Size (New_T, RM_Size (Typ));
7498 Set_Scalar_Range (New_T,
7499 Make_Range (Sloc (Entry_Name),
7500 Low_Bound => Actual_Discriminant_Ref (Lo),
7501 High_Bound => Actual_Discriminant_Ref (Hi)));
7505 end Actual_Index_Type;
7507 -- Start of processing for Resolve_Entry
7510 -- Find name of entry being called, and resolve prefix of name with its
7511 -- own type. The prefix can be overloaded, and the name and signature of
7512 -- the entry must be taken into account.
7514 if Nkind (Entry_Name) = N_Indexed_Component then
7516 -- Case of dealing with entry family within the current tasks
7518 E_Name := Prefix (Entry_Name);
7521 E_Name := Entry_Name;
7524 if Is_Entity_Name (E_Name) then
7526 -- Entry call to an entry (or entry family) in the current task. This
7527 -- is legal even though the task will deadlock. Rewrite as call to
7530 -- This can also be a call to an entry in an enclosing task. If this
7531 -- is a single task, we have to retrieve its name, because the scope
7532 -- of the entry is the task type, not the object. If the enclosing
7533 -- task is a task type, the identity of the task is given by its own
7536 -- Finally this can be a requeue on an entry of the same task or
7537 -- protected object.
7539 S := Scope (Entity (E_Name));
7541 for J in reverse 0 .. Scope_Stack.Last loop
7542 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7543 and then not Comes_From_Source (S)
7545 -- S is an enclosing task or protected object. The concurrent
7546 -- declaration has been converted into a type declaration, and
7547 -- the object itself has an object declaration that follows
7548 -- the type in the same declarative part.
7550 Tsk := Next_Entity (S);
7551 while Etype (Tsk) /= S loop
7558 elsif S = Scope_Stack.Table (J).Entity then
7560 -- Call to current task. Will be transformed into call to Self
7568 Make_Selected_Component (Loc,
7569 Prefix => New_Occurrence_Of (S, Loc),
7571 New_Occurrence_Of (Entity (E_Name), Loc));
7572 Rewrite (E_Name, New_N);
7575 elsif Nkind (Entry_Name) = N_Selected_Component
7576 and then Is_Overloaded (Prefix (Entry_Name))
7578 -- Use the entry name (which must be unique at this point) to find
7579 -- the prefix that returns the corresponding task/protected type.
7582 Pref : constant Node_Id := Prefix (Entry_Name);
7583 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7588 Get_First_Interp (Pref, I, It);
7589 while Present (It.Typ) loop
7590 if Scope (Ent) = It.Typ then
7591 Set_Etype (Pref, It.Typ);
7595 Get_Next_Interp (I, It);
7600 if Nkind (Entry_Name) = N_Selected_Component then
7601 Resolve (Prefix (Entry_Name));
7603 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7604 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7605 Resolve (Prefix (Prefix (Entry_Name)));
7606 Index := First (Expressions (Entry_Name));
7607 Resolve (Index, Entry_Index_Type (Nam));
7609 -- Generate a reference for the index when it denotes an entity
7611 if Is_Entity_Name (Index) then
7612 Generate_Reference (Entity (Index), Nam);
7615 -- Up to this point the expression could have been the actual in a
7616 -- simple entry call, and be given by a named association.
7618 if Nkind (Index) = N_Parameter_Association then
7619 Error_Msg_N ("expect expression for entry index", Index);
7621 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7626 ------------------------
7627 -- Resolve_Entry_Call --
7628 ------------------------
7630 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7631 Entry_Name : constant Node_Id := Name (N);
7632 Loc : constant Source_Ptr := Sloc (Entry_Name);
7640 -- We kill all checks here, because it does not seem worth the effort to
7641 -- do anything better, an entry call is a big operation.
7645 -- Processing of the name is similar for entry calls and protected
7646 -- operation calls. Once the entity is determined, we can complete
7647 -- the resolution of the actuals.
7649 -- The selector may be overloaded, in the case of a protected object
7650 -- with overloaded functions. The type of the context is used for
7653 if Nkind (Entry_Name) = N_Selected_Component
7654 and then Is_Overloaded (Selector_Name (Entry_Name))
7655 and then Typ /= Standard_Void_Type
7662 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7663 while Present (It.Typ) loop
7664 if Covers (Typ, It.Typ) then
7665 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7666 Set_Etype (Entry_Name, It.Typ);
7668 Generate_Reference (It.Typ, N, ' ');
7671 Get_Next_Interp (I, It);
7676 Resolve_Entry (Entry_Name);
7678 if Nkind (Entry_Name) = N_Selected_Component then
7680 -- Simple entry or protected operation call
7682 Nam := Entity (Selector_Name (Entry_Name));
7683 Obj := Prefix (Entry_Name);
7685 if Is_Subprogram (Nam) then
7686 Check_For_Eliminated_Subprogram (Entry_Name, Nam);
7689 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7691 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7693 -- Call to member of entry family
7695 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7696 Obj := Prefix (Prefix (Entry_Name));
7697 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7700 -- We cannot in general check the maximum depth of protected entry calls
7701 -- at compile time. But we can tell that any protected entry call at all
7702 -- violates a specified nesting depth of zero.
7704 if Is_Protected_Type (Scope (Nam)) then
7705 Check_Restriction (Max_Entry_Queue_Length, N);
7708 -- Use context type to disambiguate a protected function that can be
7709 -- called without actuals and that returns an array type, and where the
7710 -- argument list may be an indexing of the returned value.
7712 if Ekind (Nam) = E_Function
7713 and then Needs_No_Actuals (Nam)
7714 and then Present (Parameter_Associations (N))
7716 ((Is_Array_Type (Etype (Nam))
7717 and then Covers (Typ, Component_Type (Etype (Nam))))
7719 or else (Is_Access_Type (Etype (Nam))
7720 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7724 Component_Type (Designated_Type (Etype (Nam))))))
7727 Index_Node : Node_Id;
7731 Make_Indexed_Component (Loc,
7733 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7734 Expressions => Parameter_Associations (N));
7736 -- Since we are correcting a node classification error made by the
7737 -- parser, we call Replace rather than Rewrite.
7739 Replace (N, Index_Node);
7740 Set_Etype (Prefix (N), Etype (Nam));
7742 Resolve_Indexed_Component (N, Typ);
7747 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7748 and then Present (Contract_Wrapper (Nam))
7749 and then Current_Scope /= Contract_Wrapper (Nam)
7751 -- Note the entity being called before rewriting the call, so that
7752 -- it appears used at this point.
7754 Generate_Reference (Nam, Entry_Name, 'r');
7756 -- Rewrite as call to the precondition wrapper, adding the task
7757 -- object to the list of actuals. If the call is to a member of an
7758 -- entry family, include the index as well.
7762 New_Actuals : List_Id;
7765 New_Actuals := New_List (Obj);
7767 if Nkind (Entry_Name) = N_Indexed_Component then
7768 Append_To (New_Actuals,
7769 New_Copy_Tree (First (Expressions (Entry_Name))));
7772 Append_List (Parameter_Associations (N), New_Actuals);
7774 Make_Procedure_Call_Statement (Loc,
7776 New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
7777 Parameter_Associations => New_Actuals);
7778 Rewrite (N, New_Call);
7780 -- Preanalyze and resolve new call. Current procedure is called
7781 -- from Resolve_Call, after which expansion will take place.
7783 Preanalyze_And_Resolve (N);
7788 -- The operation name may have been overloaded. Order the actuals
7789 -- according to the formals of the resolved entity, and set the return
7790 -- type to that of the operation.
7793 Normalize_Actuals (N, Nam, False, Norm_OK);
7794 pragma Assert (Norm_OK);
7795 Set_Etype (N, Etype (Nam));
7797 -- Reset the Is_Overloaded flag, since resolution is now completed
7799 -- Simple entry call
7801 if Nkind (Entry_Name) = N_Selected_Component then
7802 Set_Is_Overloaded (Selector_Name (Entry_Name), False);
7804 -- Call to a member of an entry family
7806 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7807 Set_Is_Overloaded (Selector_Name (Prefix (Entry_Name)), False);
7811 Resolve_Actuals (N, Nam);
7812 Check_Internal_Protected_Use (N, Nam);
7814 -- Create a call reference to the entry
7816 Generate_Reference (Nam, Entry_Name, 's');
7818 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7819 Check_Potentially_Blocking_Operation (N);
7822 -- Verify that a procedure call cannot masquerade as an entry
7823 -- call where an entry call is expected.
7825 if Ekind (Nam) = E_Procedure then
7826 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7827 and then N = Entry_Call_Statement (Parent (N))
7829 Error_Msg_N ("entry call required in select statement", N);
7831 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7832 and then N = Triggering_Statement (Parent (N))
7834 Error_Msg_N ("triggering statement cannot be procedure call", N);
7836 elsif Ekind (Scope (Nam)) = E_Task_Type
7837 and then not In_Open_Scopes (Scope (Nam))
7839 Error_Msg_N ("task has no entry with this name", Entry_Name);
7843 -- After resolution, entry calls and protected procedure calls are
7844 -- changed into entry calls, for expansion. The structure of the node
7845 -- does not change, so it can safely be done in place. Protected
7846 -- function calls must keep their structure because they are
7849 if Ekind (Nam) /= E_Function then
7851 -- A protected operation that is not a function may modify the
7852 -- corresponding object, and cannot apply to a constant. If this
7853 -- is an internal call, the prefix is the type itself.
7855 if Is_Protected_Type (Scope (Nam))
7856 and then not Is_Variable (Obj)
7857 and then (not Is_Entity_Name (Obj)
7858 or else not Is_Type (Entity (Obj)))
7861 ("prefix of protected procedure or entry call must be variable",
7866 Entry_Call : Node_Id;
7870 Make_Entry_Call_Statement (Loc,
7872 Parameter_Associations => Parameter_Associations (N));
7874 -- Inherit relevant attributes from the original call
7876 Set_First_Named_Actual
7877 (Entry_Call, First_Named_Actual (N));
7879 Set_Is_Elaboration_Checks_OK_Node
7880 (Entry_Call, Is_Elaboration_Checks_OK_Node (N));
7882 Set_Is_Elaboration_Warnings_OK_Node
7883 (Entry_Call, Is_Elaboration_Warnings_OK_Node (N));
7885 Set_Is_SPARK_Mode_On_Node
7886 (Entry_Call, Is_SPARK_Mode_On_Node (N));
7888 Rewrite (N, Entry_Call);
7889 Set_Analyzed (N, True);
7892 -- Protected functions can return on the secondary stack, in which case
7893 -- we must trigger the transient scope mechanism.
7895 elsif Expander_Active
7896 and then Requires_Transient_Scope (Etype (Nam))
7898 Establish_Transient_Scope (N, Manage_Sec_Stack => True);
7900 end Resolve_Entry_Call;
7902 -------------------------
7903 -- Resolve_Equality_Op --
7904 -------------------------
7906 -- Both arguments must have the same type, and the boolean context does
7907 -- not participate in the resolution. The first pass verifies that the
7908 -- interpretation is not ambiguous, and the type of the left argument is
7909 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7910 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7911 -- though they carry a single (universal) type. Diagnose this case here.
7913 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7914 L : constant Node_Id := Left_Opnd (N);
7915 R : constant Node_Id := Right_Opnd (N);
7916 T : Entity_Id := Find_Unique_Type (L, R);
7918 procedure Check_If_Expression (Cond : Node_Id);
7919 -- The resolution rule for if expressions requires that each such must
7920 -- have a unique type. This means that if several dependent expressions
7921 -- are of a non-null anonymous access type, and the context does not
7922 -- impose an expected type (as can be the case in an equality operation)
7923 -- the expression must be rejected.
7925 procedure Explain_Redundancy (N : Node_Id);
7926 -- Attempt to explain the nature of a redundant comparison with True. If
7927 -- the expression N is too complex, this routine issues a general error
7930 function Find_Unique_Access_Type return Entity_Id;
7931 -- In the case of allocators and access attributes, the context must
7932 -- provide an indication of the specific access type to be used. If
7933 -- one operand is of such a "generic" access type, check whether there
7934 -- is a specific visible access type that has the same designated type.
7935 -- This is semantically dubious, and of no interest to any real code,
7936 -- but c48008a makes it all worthwhile.
7938 -------------------------
7939 -- Check_If_Expression --
7940 -------------------------
7942 procedure Check_If_Expression (Cond : Node_Id) is
7943 Then_Expr : Node_Id;
7944 Else_Expr : Node_Id;
7947 if Nkind (Cond) = N_If_Expression then
7948 Then_Expr := Next (First (Expressions (Cond)));
7949 Else_Expr := Next (Then_Expr);
7951 if Nkind (Then_Expr) /= N_Null
7952 and then Nkind (Else_Expr) /= N_Null
7954 Error_Msg_N ("cannot determine type of if expression", Cond);
7957 end Check_If_Expression;
7959 ------------------------
7960 -- Explain_Redundancy --
7961 ------------------------
7963 procedure Explain_Redundancy (N : Node_Id) is
7971 -- Strip the operand down to an entity
7974 if Nkind (Val) = N_Selected_Component then
7975 Val := Selector_Name (Val);
7981 -- The construct denotes an entity
7983 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7984 Val_Id := Entity (Val);
7986 -- Do not generate an error message when the comparison is done
7987 -- against the enumeration literal Standard.True.
7989 if Ekind (Val_Id) /= E_Enumeration_Literal then
7991 -- Build a customized error message
7994 Add_Str_To_Name_Buffer ("?r?");
7996 if Ekind (Val_Id) = E_Component then
7997 Add_Str_To_Name_Buffer ("component ");
7999 elsif Ekind (Val_Id) = E_Constant then
8000 Add_Str_To_Name_Buffer ("constant ");
8002 elsif Ekind (Val_Id) = E_Discriminant then
8003 Add_Str_To_Name_Buffer ("discriminant ");
8005 elsif Is_Formal (Val_Id) then
8006 Add_Str_To_Name_Buffer ("parameter ");
8008 elsif Ekind (Val_Id) = E_Variable then
8009 Add_Str_To_Name_Buffer ("variable ");
8012 Add_Str_To_Name_Buffer ("& is always True!");
8015 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
8018 -- The construct is too complex to disect, issue a general message
8021 Error_Msg_N ("?r?expression is always True!", Val);
8023 end Explain_Redundancy;
8025 -----------------------------
8026 -- Find_Unique_Access_Type --
8027 -----------------------------
8029 function Find_Unique_Access_Type return Entity_Id is
8035 if Ekind_In (Etype (R), E_Allocator_Type,
8036 E_Access_Attribute_Type)
8038 Acc := Designated_Type (Etype (R));
8040 elsif Ekind_In (Etype (L), E_Allocator_Type,
8041 E_Access_Attribute_Type)
8043 Acc := Designated_Type (Etype (L));
8049 while S /= Standard_Standard loop
8050 E := First_Entity (S);
8051 while Present (E) loop
8053 and then Is_Access_Type (E)
8054 and then Ekind (E) /= E_Allocator_Type
8055 and then Designated_Type (E) = Base_Type (Acc)
8067 end Find_Unique_Access_Type;
8069 -- Start of processing for Resolve_Equality_Op
8072 Set_Etype (N, Base_Type (Typ));
8073 Generate_Reference (T, N, ' ');
8075 if T = Any_Fixed then
8076 T := Unique_Fixed_Point_Type (L);
8079 if T /= Any_Type then
8080 if T = Any_String or else
8081 T = Any_Composite or else
8084 if T = Any_Character then
8085 Ambiguous_Character (L);
8087 Error_Msg_N ("ambiguous operands for equality", N);
8090 Set_Etype (N, Any_Type);
8093 elsif T = Any_Access
8094 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
8096 T := Find_Unique_Access_Type;
8099 Error_Msg_N ("ambiguous operands for equality", N);
8100 Set_Etype (N, Any_Type);
8104 -- If expressions must have a single type, and if the context does
8105 -- not impose one the dependent expressions cannot be anonymous
8108 -- Why no similar processing for case expressions???
8110 elsif Ada_Version >= Ada_2012
8111 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
8112 E_Anonymous_Access_Subprogram_Type)
8113 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
8114 E_Anonymous_Access_Subprogram_Type)
8116 Check_If_Expression (L);
8117 Check_If_Expression (R);
8123 -- In SPARK, equality operators = and /= for array types other than
8124 -- String are only defined when, for each index position, the
8125 -- operands have equal static bounds.
8127 if Is_Array_Type (T) then
8129 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8130 -- operation if not needed.
8132 if Restriction_Check_Required (SPARK_05)
8133 and then Base_Type (T) /= Standard_String
8134 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
8135 and then Etype (L) /= Any_Composite -- or else L in error
8136 and then Etype (R) /= Any_Composite -- or else R in error
8137 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
8139 Check_SPARK_05_Restriction
8140 ("array types should have matching static bounds", N);
8144 -- If the unique type is a class-wide type then it will be expanded
8145 -- into a dispatching call to the predefined primitive. Therefore we
8146 -- check here for potential violation of such restriction.
8148 if Is_Class_Wide_Type (T) then
8149 Check_Restriction (No_Dispatching_Calls, N);
8152 -- Only warn for redundant equality comparison to True for objects
8153 -- (e.g. "X = True") and operations (e.g. "(X < Y) = True"). For
8154 -- other expressions, it may be a matter of preference to write
8155 -- "Expr = True" or "Expr".
8157 if Warn_On_Redundant_Constructs
8158 and then Comes_From_Source (N)
8159 and then Comes_From_Source (R)
8160 and then Is_Entity_Name (R)
8161 and then Entity (R) = Standard_True
8163 ((Is_Entity_Name (L) and then Is_Object (Entity (L)))
8167 Error_Msg_N -- CODEFIX
8168 ("?r?comparison with True is redundant!", N);
8169 Explain_Redundancy (Original_Node (R));
8172 Check_Unset_Reference (L);
8173 Check_Unset_Reference (R);
8174 Generate_Operator_Reference (N, T);
8175 Check_Low_Bound_Tested (N);
8177 -- If this is an inequality, it may be the implicit inequality
8178 -- created for a user-defined operation, in which case the corres-
8179 -- ponding equality operation is not intrinsic, and the operation
8180 -- cannot be constant-folded. Else fold.
8182 if Nkind (N) = N_Op_Eq
8183 or else Comes_From_Source (Entity (N))
8184 or else Ekind (Entity (N)) = E_Operator
8185 or else Is_Intrinsic_Subprogram
8186 (Corresponding_Equality (Entity (N)))
8188 Analyze_Dimension (N);
8189 Eval_Relational_Op (N);
8191 elsif Nkind (N) = N_Op_Ne
8192 and then Is_Abstract_Subprogram (Entity (N))
8194 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
8197 -- Ada 2005: If one operand is an anonymous access type, convert the
8198 -- other operand to it, to ensure that the underlying types match in
8199 -- the back-end. Same for access_to_subprogram, and the conversion
8200 -- verifies that the types are subtype conformant.
8202 -- We apply the same conversion in the case one of the operands is a
8203 -- private subtype of the type of the other.
8205 -- Why the Expander_Active test here ???
8209 (Ekind_In (T, E_Anonymous_Access_Type,
8210 E_Anonymous_Access_Subprogram_Type)
8211 or else Is_Private_Type (T))
8213 if Etype (L) /= T then
8215 Make_Unchecked_Type_Conversion (Sloc (L),
8216 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
8217 Expression => Relocate_Node (L)));
8218 Analyze_And_Resolve (L, T);
8221 if (Etype (R)) /= T then
8223 Make_Unchecked_Type_Conversion (Sloc (R),
8224 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
8225 Expression => Relocate_Node (R)));
8226 Analyze_And_Resolve (R, T);
8230 end Resolve_Equality_Op;
8232 ----------------------------------
8233 -- Resolve_Explicit_Dereference --
8234 ----------------------------------
8236 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
8237 Loc : constant Source_Ptr := Sloc (N);
8239 P : constant Node_Id := Prefix (N);
8242 -- The candidate prefix type, if overloaded
8248 Check_Fully_Declared_Prefix (Typ, P);
8251 -- A useful optimization: check whether the dereference denotes an
8252 -- element of a container, and if so rewrite it as a call to the
8253 -- corresponding Element function.
8255 -- Disabled for now, on advice of ARG. A more restricted form of the
8256 -- predicate might be acceptable ???
8258 -- if Is_Container_Element (N) then
8262 if Is_Overloaded (P) then
8264 -- Use the context type to select the prefix that has the correct
8265 -- designated type. Keep the first match, which will be the inner-
8268 Get_First_Interp (P, I, It);
8270 while Present (It.Typ) loop
8271 if Is_Access_Type (It.Typ)
8272 and then Covers (Typ, Designated_Type (It.Typ))
8278 -- Remove access types that do not match, but preserve access
8279 -- to subprogram interpretations, in case a further dereference
8280 -- is needed (see below).
8282 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8286 Get_Next_Interp (I, It);
8289 if Present (P_Typ) then
8291 Set_Etype (N, Designated_Type (P_Typ));
8294 -- If no interpretation covers the designated type of the prefix,
8295 -- this is the pathological case where not all implementations of
8296 -- the prefix allow the interpretation of the node as a call. Now
8297 -- that the expected type is known, Remove other interpretations
8298 -- from prefix, rewrite it as a call, and resolve again, so that
8299 -- the proper call node is generated.
8301 Get_First_Interp (P, I, It);
8302 while Present (It.Typ) loop
8303 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8307 Get_Next_Interp (I, It);
8311 Make_Function_Call (Loc,
8313 Make_Explicit_Dereference (Loc,
8315 Parameter_Associations => New_List);
8317 Save_Interps (N, New_N);
8319 Analyze_And_Resolve (N, Typ);
8323 -- If not overloaded, resolve P with its own type
8329 -- If the prefix might be null, add an access check
8331 if Is_Access_Type (Etype (P))
8332 and then not Can_Never_Be_Null (Etype (P))
8334 Apply_Access_Check (N);
8337 -- If the designated type is a packed unconstrained array type, and the
8338 -- explicit dereference is not in the context of an attribute reference,
8339 -- then we must compute and set the actual subtype, since it is needed
8340 -- by Gigi. The reason we exclude the attribute case is that this is
8341 -- handled fine by Gigi, and in fact we use such attributes to build the
8342 -- actual subtype. We also exclude generated code (which builds actual
8343 -- subtypes directly if they are needed).
8345 if Is_Array_Type (Etype (N))
8346 and then Is_Packed (Etype (N))
8347 and then not Is_Constrained (Etype (N))
8348 and then Nkind (Parent (N)) /= N_Attribute_Reference
8349 and then Comes_From_Source (N)
8351 Set_Etype (N, Get_Actual_Subtype (N));
8354 Analyze_Dimension (N);
8356 -- Note: No Eval processing is required for an explicit dereference,
8357 -- because such a name can never be static.
8359 end Resolve_Explicit_Dereference;
8361 -------------------------------------
8362 -- Resolve_Expression_With_Actions --
8363 -------------------------------------
8365 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8369 -- If N has no actions, and its expression has been constant folded,
8370 -- then rewrite N as just its expression. Note, we can't do this in
8371 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8372 -- Expression (N) to be expanded again.
8374 if Is_Empty_List (Actions (N))
8375 and then Compile_Time_Known_Value (Expression (N))
8377 Rewrite (N, Expression (N));
8379 end Resolve_Expression_With_Actions;
8381 ----------------------------------
8382 -- Resolve_Generalized_Indexing --
8383 ----------------------------------
8385 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8386 Indexing : constant Node_Id := Generalized_Indexing (N);
8392 -- In ASIS mode, propagate the information about the indexes back to
8393 -- to the original indexing node. The generalized indexing is either
8394 -- a function call, or a dereference of one. The actuals include the
8395 -- prefix of the original node, which is the container expression.
8398 Resolve (Indexing, Typ);
8399 Set_Etype (N, Etype (Indexing));
8400 Set_Is_Overloaded (N, False);
8403 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8405 Call := Prefix (Call);
8408 if Nkind (Call) = N_Function_Call then
8409 Indexes := New_Copy_List (Parameter_Associations (Call));
8410 Pref := Remove_Head (Indexes);
8411 Set_Expressions (N, Indexes);
8413 -- If expression is to be reanalyzed, reset Generalized_Indexing
8414 -- to recreate call node, as is the case when the expression is
8415 -- part of an expression function.
8417 if In_Spec_Expression then
8418 Set_Generalized_Indexing (N, Empty);
8421 Set_Prefix (N, Pref);
8425 Rewrite (N, Indexing);
8428 end Resolve_Generalized_Indexing;
8430 ---------------------------
8431 -- Resolve_If_Expression --
8432 ---------------------------
8434 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8435 Condition : constant Node_Id := First (Expressions (N));
8436 Then_Expr : Node_Id;
8437 Else_Expr : Node_Id;
8438 Else_Typ : Entity_Id;
8439 Then_Typ : Entity_Id;
8442 -- Defend against malformed expressions
8444 if No (Condition) then
8448 Then_Expr := Next (Condition);
8450 if No (Then_Expr) then
8454 Else_Expr := Next (Then_Expr);
8456 Resolve (Condition, Any_Boolean);
8457 Resolve (Then_Expr, Typ);
8458 Then_Typ := Etype (Then_Expr);
8460 -- When the "then" expression is of a scalar subtype different from the
8461 -- result subtype, then insert a conversion to ensure the generation of
8462 -- a constraint check. The same is done for the else part below, again
8463 -- comparing subtypes rather than base types.
8465 if Is_Scalar_Type (Then_Typ) and then Then_Typ /= Typ then
8466 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8467 Analyze_And_Resolve (Then_Expr, Typ);
8470 -- If ELSE expression present, just resolve using the determined type
8471 -- If type is universal, resolve to any member of the class.
8473 if Present (Else_Expr) then
8474 if Typ = Universal_Integer then
8475 Resolve (Else_Expr, Any_Integer);
8477 elsif Typ = Universal_Real then
8478 Resolve (Else_Expr, Any_Real);
8481 Resolve (Else_Expr, Typ);
8484 Else_Typ := Etype (Else_Expr);
8486 if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
8487 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8488 Analyze_And_Resolve (Else_Expr, Typ);
8490 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8491 -- dynamically tagged must be known statically.
8493 elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8494 if Is_Dynamically_Tagged (Then_Expr) /=
8495 Is_Dynamically_Tagged (Else_Expr)
8497 Error_Msg_N ("all or none of the dependent expressions "
8498 & "can be dynamically tagged", N);
8502 -- If no ELSE expression is present, root type must be Standard.Boolean
8503 -- and we provide a Standard.True result converted to the appropriate
8504 -- Boolean type (in case it is a derived boolean type).
8506 elsif Root_Type (Typ) = Standard_Boolean then
8508 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8509 Analyze_And_Resolve (Else_Expr, Typ);
8510 Append_To (Expressions (N), Else_Expr);
8513 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8514 Append_To (Expressions (N), Error);
8519 if not Error_Posted (N) then
8520 Eval_If_Expression (N);
8523 Analyze_Dimension (N);
8524 end Resolve_If_Expression;
8526 -------------------------------
8527 -- Resolve_Indexed_Component --
8528 -------------------------------
8530 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8531 Name : constant Node_Id := Prefix (N);
8533 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8537 if Present (Generalized_Indexing (N)) then
8538 Resolve_Generalized_Indexing (N, Typ);
8542 if Is_Overloaded (Name) then
8544 -- Use the context type to select the prefix that yields the correct
8550 I1 : Interp_Index := 0;
8551 P : constant Node_Id := Prefix (N);
8552 Found : Boolean := False;
8555 Get_First_Interp (P, I, It);
8556 while Present (It.Typ) loop
8557 if (Is_Array_Type (It.Typ)
8558 and then Covers (Typ, Component_Type (It.Typ)))
8559 or else (Is_Access_Type (It.Typ)
8560 and then Is_Array_Type (Designated_Type (It.Typ))
8564 Component_Type (Designated_Type (It.Typ))))
8567 It := Disambiguate (P, I1, I, Any_Type);
8569 if It = No_Interp then
8570 Error_Msg_N ("ambiguous prefix for indexing", N);
8576 Array_Type := It.Typ;
8582 Array_Type := It.Typ;
8587 Get_Next_Interp (I, It);
8592 Array_Type := Etype (Name);
8595 Resolve (Name, Array_Type);
8596 Array_Type := Get_Actual_Subtype_If_Available (Name);
8598 -- If prefix is access type, dereference to get real array type.
8599 -- Note: we do not apply an access check because the expander always
8600 -- introduces an explicit dereference, and the check will happen there.
8602 if Is_Access_Type (Array_Type) then
8603 Array_Type := Designated_Type (Array_Type);
8606 -- If name was overloaded, set component type correctly now
8607 -- If a misplaced call to an entry family (which has no index types)
8608 -- return. Error will be diagnosed from calling context.
8610 if Is_Array_Type (Array_Type) then
8611 Set_Etype (N, Component_Type (Array_Type));
8616 Index := First_Index (Array_Type);
8617 Expr := First (Expressions (N));
8619 -- The prefix may have resolved to a string literal, in which case its
8620 -- etype has a special representation. This is only possible currently
8621 -- if the prefix is a static concatenation, written in functional
8624 if Ekind (Array_Type) = E_String_Literal_Subtype then
8625 Resolve (Expr, Standard_Positive);
8628 while Present (Index) and Present (Expr) loop
8629 Resolve (Expr, Etype (Index));
8630 Check_Unset_Reference (Expr);
8632 if Is_Scalar_Type (Etype (Expr)) then
8633 Apply_Scalar_Range_Check (Expr, Etype (Index));
8635 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8643 Analyze_Dimension (N);
8645 -- Do not generate the warning on suspicious index if we are analyzing
8646 -- package Ada.Tags; otherwise we will report the warning with the
8647 -- Prims_Ptr field of the dispatch table.
8649 if Scope (Etype (Prefix (N))) = Standard_Standard
8651 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8654 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8655 Eval_Indexed_Component (N);
8658 -- If the array type is atomic, and the component is not atomic, then
8659 -- this is worth a warning, since we have a situation where the access
8660 -- to the component may cause extra read/writes of the atomic array
8661 -- object, or partial word accesses, which could be unexpected.
8663 if Nkind (N) = N_Indexed_Component
8664 and then Is_Atomic_Ref_With_Address (N)
8665 and then not (Has_Atomic_Components (Array_Type)
8666 or else (Is_Entity_Name (Prefix (N))
8667 and then Has_Atomic_Components
8668 (Entity (Prefix (N)))))
8669 and then not Is_Atomic (Component_Type (Array_Type))
8672 ("??access to non-atomic component of atomic array", Prefix (N));
8674 ("??\may cause unexpected accesses to atomic object", Prefix (N));
8676 end Resolve_Indexed_Component;
8678 -----------------------------
8679 -- Resolve_Integer_Literal --
8680 -----------------------------
8682 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8685 Eval_Integer_Literal (N);
8686 end Resolve_Integer_Literal;
8688 --------------------------------
8689 -- Resolve_Intrinsic_Operator --
8690 --------------------------------
8692 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8693 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8698 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8699 -- If the operand is a literal, it cannot be the expression in a
8700 -- conversion. Use a qualified expression instead.
8702 ---------------------
8703 -- Convert_Operand --
8704 ---------------------
8706 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8707 Loc : constant Source_Ptr := Sloc (Opnd);
8711 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8713 Make_Qualified_Expression (Loc,
8714 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8715 Expression => Relocate_Node (Opnd));
8719 Res := Unchecked_Convert_To (Btyp, Opnd);
8723 end Convert_Operand;
8725 -- Start of processing for Resolve_Intrinsic_Operator
8728 -- We must preserve the original entity in a generic setting, so that
8729 -- the legality of the operation can be verified in an instance.
8731 if not Expander_Active then
8736 while Scope (Op) /= Standard_Standard loop
8738 pragma Assert (Present (Op));
8742 Set_Is_Overloaded (N, False);
8744 -- If the result or operand types are private, rewrite with unchecked
8745 -- conversions on the operands and the result, to expose the proper
8746 -- underlying numeric type.
8748 if Is_Private_Type (Typ)
8749 or else Is_Private_Type (Etype (Left_Opnd (N)))
8750 or else Is_Private_Type (Etype (Right_Opnd (N)))
8752 Arg1 := Convert_Operand (Left_Opnd (N));
8754 if Nkind (N) = N_Op_Expon then
8755 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8757 Arg2 := Convert_Operand (Right_Opnd (N));
8760 if Nkind (Arg1) = N_Type_Conversion then
8761 Save_Interps (Left_Opnd (N), Expression (Arg1));
8764 if Nkind (Arg2) = N_Type_Conversion then
8765 Save_Interps (Right_Opnd (N), Expression (Arg2));
8768 Set_Left_Opnd (N, Arg1);
8769 Set_Right_Opnd (N, Arg2);
8771 Set_Etype (N, Btyp);
8772 Rewrite (N, Unchecked_Convert_To (Typ, N));
8775 elsif Typ /= Etype (Left_Opnd (N))
8776 or else Typ /= Etype (Right_Opnd (N))
8778 -- Add explicit conversion where needed, and save interpretations in
8779 -- case operands are overloaded.
8781 Arg1 := Convert_To (Typ, Left_Opnd (N));
8782 Arg2 := Convert_To (Typ, Right_Opnd (N));
8784 if Nkind (Arg1) = N_Type_Conversion then
8785 Save_Interps (Left_Opnd (N), Expression (Arg1));
8787 Save_Interps (Left_Opnd (N), Arg1);
8790 if Nkind (Arg2) = N_Type_Conversion then
8791 Save_Interps (Right_Opnd (N), Expression (Arg2));
8793 Save_Interps (Right_Opnd (N), Arg2);
8796 Rewrite (Left_Opnd (N), Arg1);
8797 Rewrite (Right_Opnd (N), Arg2);
8800 Resolve_Arithmetic_Op (N, Typ);
8803 Resolve_Arithmetic_Op (N, Typ);
8805 end Resolve_Intrinsic_Operator;
8807 --------------------------------------
8808 -- Resolve_Intrinsic_Unary_Operator --
8809 --------------------------------------
8811 procedure Resolve_Intrinsic_Unary_Operator
8815 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8821 while Scope (Op) /= Standard_Standard loop
8823 pragma Assert (Present (Op));
8828 if Is_Private_Type (Typ) then
8829 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8830 Save_Interps (Right_Opnd (N), Expression (Arg2));
8832 Set_Right_Opnd (N, Arg2);
8834 Set_Etype (N, Btyp);
8835 Rewrite (N, Unchecked_Convert_To (Typ, N));
8839 Resolve_Unary_Op (N, Typ);
8841 end Resolve_Intrinsic_Unary_Operator;
8843 ------------------------
8844 -- Resolve_Logical_Op --
8845 ------------------------
8847 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8851 Check_No_Direct_Boolean_Operators (N);
8853 -- Predefined operations on scalar types yield the base type. On the
8854 -- other hand, logical operations on arrays yield the type of the
8855 -- arguments (and the context).
8857 if Is_Array_Type (Typ) then
8860 B_Typ := Base_Type (Typ);
8863 -- The following test is required because the operands of the operation
8864 -- may be literals, in which case the resulting type appears to be
8865 -- compatible with a signed integer type, when in fact it is compatible
8866 -- only with modular types. If the context itself is universal, the
8867 -- operation is illegal.
8869 if not Valid_Boolean_Arg (Typ) then
8870 Error_Msg_N ("invalid context for logical operation", N);
8871 Set_Etype (N, Any_Type);
8874 elsif Typ = Any_Modular then
8876 ("no modular type available in this context", N);
8877 Set_Etype (N, Any_Type);
8880 elsif Is_Modular_Integer_Type (Typ)
8881 and then Etype (Left_Opnd (N)) = Universal_Integer
8882 and then Etype (Right_Opnd (N)) = Universal_Integer
8884 Check_For_Visible_Operator (N, B_Typ);
8887 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8888 -- is active and the result type is standard Boolean (do not mess with
8889 -- ops that return a nonstandard Boolean type, because something strange
8892 -- Note: you might expect this replacement to be done during expansion,
8893 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8894 -- is used, no part of the right operand of an "and" or "or" operator
8895 -- should be executed if the left operand would short-circuit the
8896 -- evaluation of the corresponding "and then" or "or else". If we left
8897 -- the replacement to expansion time, then run-time checks associated
8898 -- with such operands would be evaluated unconditionally, due to being
8899 -- before the condition prior to the rewriting as short-circuit forms
8900 -- during expansion.
8902 if Short_Circuit_And_Or
8903 and then B_Typ = Standard_Boolean
8904 and then Nkind_In (N, N_Op_And, N_Op_Or)
8906 -- Mark the corresponding putative SCO operator as truly a logical
8907 -- (and short-circuit) operator.
8909 if Generate_SCO and then Comes_From_Source (N) then
8910 Set_SCO_Logical_Operator (N);
8913 if Nkind (N) = N_Op_And then
8915 Make_And_Then (Sloc (N),
8916 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8917 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8918 Analyze_And_Resolve (N, B_Typ);
8920 -- Case of OR changed to OR ELSE
8924 Make_Or_Else (Sloc (N),
8925 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8926 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8927 Analyze_And_Resolve (N, B_Typ);
8930 -- Return now, since analysis of the rewritten ops will take care of
8931 -- other reference bookkeeping and expression folding.
8936 Resolve (Left_Opnd (N), B_Typ);
8937 Resolve (Right_Opnd (N), B_Typ);
8939 Check_Unset_Reference (Left_Opnd (N));
8940 Check_Unset_Reference (Right_Opnd (N));
8942 Set_Etype (N, B_Typ);
8943 Generate_Operator_Reference (N, B_Typ);
8944 Eval_Logical_Op (N);
8946 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8947 -- only when both operands have same static lower and higher bounds. Of
8948 -- course the types have to match, so only check if operands are
8949 -- compatible and the node itself has no errors.
8951 if Is_Array_Type (B_Typ)
8952 and then Nkind (N) in N_Binary_Op
8955 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8956 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8959 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8960 -- operation if not needed.
8962 if Restriction_Check_Required (SPARK_05)
8963 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8964 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8965 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8966 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8968 Check_SPARK_05_Restriction
8969 ("array types should have matching static bounds", N);
8973 end Resolve_Logical_Op;
8975 ---------------------------
8976 -- Resolve_Membership_Op --
8977 ---------------------------
8979 -- The context can only be a boolean type, and does not determine the
8980 -- arguments. Arguments should be unambiguous, but the preference rule for
8981 -- universal types applies.
8983 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8984 pragma Warnings (Off, Typ);
8986 L : constant Node_Id := Left_Opnd (N);
8987 R : constant Node_Id := Right_Opnd (N);
8990 procedure Resolve_Set_Membership;
8991 -- Analysis has determined a unique type for the left operand. Use it to
8992 -- resolve the disjuncts.
8994 ----------------------------
8995 -- Resolve_Set_Membership --
8996 ----------------------------
8998 procedure Resolve_Set_Membership is
9003 -- If the left operand is overloaded, find type compatible with not
9004 -- overloaded alternative of the right operand.
9006 if Is_Overloaded (L) then
9008 Alt := First (Alternatives (N));
9009 while Present (Alt) loop
9010 if not Is_Overloaded (Alt) then
9011 Ltyp := Intersect_Types (L, Alt);
9018 -- Unclear how to resolve expression if all alternatives are also
9022 Error_Msg_N ("ambiguous expression", N);
9031 Alt := First (Alternatives (N));
9032 while Present (Alt) loop
9034 -- Alternative is an expression, a range
9035 -- or a subtype mark.
9037 if not Is_Entity_Name (Alt)
9038 or else not Is_Type (Entity (Alt))
9040 Resolve (Alt, Ltyp);
9046 -- Check for duplicates for discrete case
9048 if Is_Discrete_Type (Ltyp) then
9055 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
9059 -- Loop checking duplicates. This is quadratic, but giant sets
9060 -- are unlikely in this context so it's a reasonable choice.
9063 Alt := First (Alternatives (N));
9064 while Present (Alt) loop
9065 if Is_OK_Static_Expression (Alt)
9066 and then (Nkind_In (Alt, N_Integer_Literal,
9067 N_Character_Literal)
9068 or else Nkind (Alt) in N_Has_Entity)
9071 Alts (Nalts) := (Alt, Expr_Value (Alt));
9073 for J in 1 .. Nalts - 1 loop
9074 if Alts (J).Val = Alts (Nalts).Val then
9075 Error_Msg_Sloc := Sloc (Alts (J).Alt);
9076 Error_Msg_N ("duplicate of value given#??", Alt);
9086 -- RM 4.5.2 (28.1/3) specifies that for types other than records or
9087 -- limited types, evaluation of a membership test uses the predefined
9088 -- equality for the type. This may be confusing to users, and the
9089 -- following warning appears useful for the most common case.
9091 if Is_Scalar_Type (Ltyp)
9092 and then Present (Get_User_Defined_Eq (Ltyp))
9095 ("membership test on& uses predefined equality?", N, Ltyp);
9097 ("\even if user-defined equality exists (RM 4.5.2 (28.1/3)?", N);
9099 end Resolve_Set_Membership;
9101 -- Start of processing for Resolve_Membership_Op
9104 if L = Error or else R = Error then
9108 if Present (Alternatives (N)) then
9109 Resolve_Set_Membership;
9112 elsif not Is_Overloaded (R)
9114 (Etype (R) = Universal_Integer
9116 Etype (R) = Universal_Real)
9117 and then Is_Overloaded (L)
9121 -- Ada 2005 (AI-251): Support the following case:
9123 -- type I is interface;
9124 -- type T is tagged ...
9126 -- function Test (O : I'Class) is
9128 -- return O in T'Class.
9131 -- In this case we have nothing else to do. The membership test will be
9132 -- done at run time.
9134 elsif Ada_Version >= Ada_2005
9135 and then Is_Class_Wide_Type (Etype (L))
9136 and then Is_Interface (Etype (L))
9137 and then not Is_Interface (Etype (R))
9141 T := Intersect_Types (L, R);
9144 -- If mixed-mode operations are present and operands are all literal,
9145 -- the only interpretation involves Duration, which is probably not
9146 -- the intention of the programmer.
9148 if T = Any_Fixed then
9149 T := Unique_Fixed_Point_Type (N);
9151 if T = Any_Type then
9157 Check_Unset_Reference (L);
9159 if Nkind (R) = N_Range
9160 and then not Is_Scalar_Type (T)
9162 Error_Msg_N ("scalar type required for range", R);
9165 if Is_Entity_Name (R) then
9166 Freeze_Expression (R);
9169 Check_Unset_Reference (R);
9172 -- Here after resolving membership operation
9176 Eval_Membership_Op (N);
9177 end Resolve_Membership_Op;
9183 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
9184 Loc : constant Source_Ptr := Sloc (N);
9187 -- Handle restriction against anonymous null access values This
9188 -- restriction can be turned off using -gnatdj.
9190 -- Ada 2005 (AI-231): Remove restriction
9192 if Ada_Version < Ada_2005
9193 and then not Debug_Flag_J
9194 and then Ekind (Typ) = E_Anonymous_Access_Type
9195 and then Comes_From_Source (N)
9197 -- In the common case of a call which uses an explicitly null value
9198 -- for an access parameter, give specialized error message.
9200 if Nkind (Parent (N)) in N_Subprogram_Call then
9202 ("null is not allowed as argument for an access parameter", N);
9204 -- Standard message for all other cases (are there any?)
9208 ("null cannot be of an anonymous access type", N);
9212 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
9213 -- assignment to a null-excluding object.
9215 if Ada_Version >= Ada_2005
9216 and then Can_Never_Be_Null (Typ)
9217 and then Nkind (Parent (N)) = N_Assignment_Statement
9219 if Inside_Init_Proc then
9221 -- Decide whether to generate an if_statement around our
9222 -- null-excluding check to avoid them on certain internal object
9223 -- declarations by looking at the type the current Init_Proc
9227 -- if T1b_skip_null_excluding_check then
9228 -- [constraint_error "access check failed"]
9231 if Needs_Conditional_Null_Excluding_Check
9232 (Etype (First_Formal (Enclosing_Init_Proc)))
9235 Make_If_Statement (Loc,
9237 Make_Identifier (Loc,
9239 (Chars (Typ), "_skip_null_excluding_check")),
9242 Make_Raise_Constraint_Error (Loc,
9243 Reason => CE_Access_Check_Failed))));
9245 -- Otherwise, simply create the check
9249 Make_Raise_Constraint_Error (Loc,
9250 Reason => CE_Access_Check_Failed));
9254 (Compile_Time_Constraint_Error (N,
9255 "(Ada 2005) null not allowed in null-excluding objects??"),
9256 Make_Raise_Constraint_Error (Loc,
9257 Reason => CE_Access_Check_Failed));
9261 -- In a distributed context, null for a remote access to subprogram may
9262 -- need to be replaced with a special record aggregate. In this case,
9263 -- return after having done the transformation.
9265 if (Ekind (Typ) = E_Record_Type
9266 or else Is_Remote_Access_To_Subprogram_Type (Typ))
9267 and then Remote_AST_Null_Value (N, Typ)
9272 -- The null literal takes its type from the context
9277 -----------------------
9278 -- Resolve_Op_Concat --
9279 -----------------------
9281 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
9283 -- We wish to avoid deep recursion, because concatenations are often
9284 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
9285 -- operands nonrecursively until we find something that is not a simple
9286 -- concatenation (A in this case). We resolve that, and then walk back
9287 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9288 -- to do the rest of the work at each level. The Parent pointers allow
9289 -- us to avoid recursion, and thus avoid running out of memory. See also
9290 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9296 -- The following code is equivalent to:
9298 -- Resolve_Op_Concat_First (NN, Typ);
9299 -- Resolve_Op_Concat_Arg (N, ...);
9300 -- Resolve_Op_Concat_Rest (N, Typ);
9302 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9303 -- operand is a concatenation.
9305 -- Walk down left operands
9308 Resolve_Op_Concat_First (NN, Typ);
9309 Op1 := Left_Opnd (NN);
9310 exit when not (Nkind (Op1) = N_Op_Concat
9311 and then not Is_Array_Type (Component_Type (Typ))
9312 and then Entity (Op1) = Entity (NN));
9316 -- Now (given the above example) NN is A&B and Op1 is A
9318 -- First resolve Op1 ...
9320 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
9322 -- ... then walk NN back up until we reach N (where we started), calling
9323 -- Resolve_Op_Concat_Rest along the way.
9326 Resolve_Op_Concat_Rest (NN, Typ);
9331 if Base_Type (Etype (N)) /= Standard_String then
9332 Check_SPARK_05_Restriction
9333 ("result of concatenation should have type String", N);
9335 end Resolve_Op_Concat;
9337 ---------------------------
9338 -- Resolve_Op_Concat_Arg --
9339 ---------------------------
9341 procedure Resolve_Op_Concat_Arg
9347 Btyp : constant Entity_Id := Base_Type (Typ);
9348 Ctyp : constant Entity_Id := Component_Type (Typ);
9353 or else (not Is_Overloaded (Arg)
9354 and then Etype (Arg) /= Any_Composite
9355 and then Covers (Ctyp, Etype (Arg)))
9357 Resolve (Arg, Ctyp);
9359 Resolve (Arg, Btyp);
9362 -- If both Array & Array and Array & Component are visible, there is a
9363 -- potential ambiguity that must be reported.
9365 elsif Has_Compatible_Type (Arg, Ctyp) then
9366 if Nkind (Arg) = N_Aggregate
9367 and then Is_Composite_Type (Ctyp)
9369 if Is_Private_Type (Ctyp) then
9370 Resolve (Arg, Btyp);
9372 -- If the operation is user-defined and not overloaded use its
9373 -- profile. The operation may be a renaming, in which case it has
9374 -- been rewritten, and we want the original profile.
9376 elsif not Is_Overloaded (N)
9377 and then Comes_From_Source (Entity (Original_Node (N)))
9378 and then Ekind (Entity (Original_Node (N))) = E_Function
9382 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9385 -- Otherwise an aggregate may match both the array type and the
9389 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9390 Set_Etype (Arg, Any_Type);
9394 if Is_Overloaded (Arg)
9395 and then Has_Compatible_Type (Arg, Typ)
9396 and then Etype (Arg) /= Any_Type
9404 Get_First_Interp (Arg, I, It);
9406 Get_Next_Interp (I, It);
9408 -- Special-case the error message when the overloading is
9409 -- caused by a function that yields an array and can be
9410 -- called without parameters.
9412 if It.Nam = Func then
9413 Error_Msg_Sloc := Sloc (Func);
9414 Error_Msg_N ("ambiguous call to function#", Arg);
9416 ("\\interpretation as call yields&", Arg, Typ);
9418 ("\\interpretation as indexing of call yields&",
9419 Arg, Component_Type (Typ));
9422 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9424 Get_First_Interp (Arg, I, It);
9425 while Present (It.Nam) loop
9426 Error_Msg_Sloc := Sloc (It.Nam);
9428 if Base_Type (It.Typ) = Btyp
9430 Base_Type (It.Typ) = Base_Type (Ctyp)
9432 Error_Msg_N -- CODEFIX
9433 ("\\possible interpretation#", Arg);
9436 Get_Next_Interp (I, It);
9442 Resolve (Arg, Component_Type (Typ));
9444 if Nkind (Arg) = N_String_Literal then
9445 Set_Etype (Arg, Component_Type (Typ));
9448 if Arg = Left_Opnd (N) then
9449 Set_Is_Component_Left_Opnd (N);
9451 Set_Is_Component_Right_Opnd (N);
9456 Resolve (Arg, Btyp);
9459 -- Concatenation is restricted in SPARK: each operand must be either a
9460 -- string literal, the name of a string constant, a static character or
9461 -- string expression, or another concatenation. Arg cannot be a
9462 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9463 -- separately on each final operand, past concatenation operations.
9465 if Is_Character_Type (Etype (Arg)) then
9466 if not Is_OK_Static_Expression (Arg) then
9467 Check_SPARK_05_Restriction
9468 ("character operand for concatenation should be static", Arg);
9471 elsif Is_String_Type (Etype (Arg)) then
9472 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9473 and then Is_Constant_Object (Entity (Arg)))
9474 and then not Is_OK_Static_Expression (Arg)
9476 Check_SPARK_05_Restriction
9477 ("string operand for concatenation should be static", Arg);
9480 -- Do not issue error on an operand that is neither a character nor a
9481 -- string, as the error is issued in Resolve_Op_Concat.
9487 Check_Unset_Reference (Arg);
9488 end Resolve_Op_Concat_Arg;
9490 -----------------------------
9491 -- Resolve_Op_Concat_First --
9492 -----------------------------
9494 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9495 Btyp : constant Entity_Id := Base_Type (Typ);
9496 Op1 : constant Node_Id := Left_Opnd (N);
9497 Op2 : constant Node_Id := Right_Opnd (N);
9500 -- The parser folds an enormous sequence of concatenations of string
9501 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9502 -- in the right operand. If the expression resolves to a predefined "&"
9503 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9504 -- we give an error. See P_Simple_Expression in Par.Ch4.
9506 if Nkind (Op2) = N_String_Literal
9507 and then Is_Folded_In_Parser (Op2)
9508 and then Ekind (Entity (N)) = E_Function
9510 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9511 and then String_Length (Strval (Op1)) = 0);
9512 Error_Msg_N ("too many user-defined concatenations", N);
9516 Set_Etype (N, Btyp);
9518 if Is_Limited_Composite (Btyp) then
9519 Error_Msg_N ("concatenation not available for limited array", N);
9520 Explain_Limited_Type (Btyp, N);
9522 end Resolve_Op_Concat_First;
9524 ----------------------------
9525 -- Resolve_Op_Concat_Rest --
9526 ----------------------------
9528 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9529 Op1 : constant Node_Id := Left_Opnd (N);
9530 Op2 : constant Node_Id := Right_Opnd (N);
9533 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9535 Generate_Operator_Reference (N, Typ);
9537 if Is_String_Type (Typ) then
9538 Eval_Concatenation (N);
9541 -- If this is not a static concatenation, but the result is a string
9542 -- type (and not an array of strings) ensure that static string operands
9543 -- have their subtypes properly constructed.
9545 if Nkind (N) /= N_String_Literal
9546 and then Is_Character_Type (Component_Type (Typ))
9548 Set_String_Literal_Subtype (Op1, Typ);
9549 Set_String_Literal_Subtype (Op2, Typ);
9551 end Resolve_Op_Concat_Rest;
9553 ----------------------
9554 -- Resolve_Op_Expon --
9555 ----------------------
9557 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9558 B_Typ : constant Entity_Id := Base_Type (Typ);
9561 -- Catch attempts to do fixed-point exponentiation with universal
9562 -- operands, which is a case where the illegality is not caught during
9563 -- normal operator analysis. This is not done in preanalysis mode
9564 -- since the tree is not fully decorated during preanalysis.
9566 if Full_Analysis then
9567 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9568 Error_Msg_N ("exponentiation not available for fixed point", N);
9571 elsif Nkind (Parent (N)) in N_Op
9572 and then Present (Etype (Parent (N)))
9573 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9574 and then Etype (N) = Universal_Real
9575 and then Comes_From_Source (N)
9577 Error_Msg_N ("exponentiation not available for fixed point", N);
9582 if Comes_From_Source (N)
9583 and then Ekind (Entity (N)) = E_Function
9584 and then Is_Imported (Entity (N))
9585 and then Is_Intrinsic_Subprogram (Entity (N))
9587 Resolve_Intrinsic_Operator (N, Typ);
9591 if Etype (Left_Opnd (N)) = Universal_Integer
9592 or else Etype (Left_Opnd (N)) = Universal_Real
9594 Check_For_Visible_Operator (N, B_Typ);
9597 -- We do the resolution using the base type, because intermediate values
9598 -- in expressions are always of the base type, not a subtype of it.
9600 Resolve (Left_Opnd (N), B_Typ);
9601 Resolve (Right_Opnd (N), Standard_Integer);
9603 -- For integer types, right argument must be in Natural range
9605 if Is_Integer_Type (Typ) then
9606 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9609 Check_Unset_Reference (Left_Opnd (N));
9610 Check_Unset_Reference (Right_Opnd (N));
9612 Set_Etype (N, B_Typ);
9613 Generate_Operator_Reference (N, B_Typ);
9615 Analyze_Dimension (N);
9617 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9618 -- Evaluate the exponentiation operator for dimensioned type
9620 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9625 -- Set overflow checking bit. Much cleverer code needed here eventually
9626 -- and perhaps the Resolve routines should be separated for the various
9627 -- arithmetic operations, since they will need different processing. ???
9629 if Nkind (N) in N_Op then
9630 if not Overflow_Checks_Suppressed (Etype (N)) then
9631 Enable_Overflow_Check (N);
9634 end Resolve_Op_Expon;
9636 --------------------
9637 -- Resolve_Op_Not --
9638 --------------------
9640 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9643 function Parent_Is_Boolean return Boolean;
9644 -- This function determines if the parent node is a boolean operator or
9645 -- operation (comparison op, membership test, or short circuit form) and
9646 -- the not in question is the left operand of this operation. Note that
9647 -- if the not is in parens, then false is returned.
9649 -----------------------
9650 -- Parent_Is_Boolean --
9651 -----------------------
9653 function Parent_Is_Boolean return Boolean is
9655 if Paren_Count (N) /= 0 then
9659 case Nkind (Parent (N)) is
9674 return Left_Opnd (Parent (N)) = N;
9680 end Parent_Is_Boolean;
9682 -- Start of processing for Resolve_Op_Not
9685 -- Predefined operations on scalar types yield the base type. On the
9686 -- other hand, logical operations on arrays yield the type of the
9687 -- arguments (and the context).
9689 if Is_Array_Type (Typ) then
9692 B_Typ := Base_Type (Typ);
9695 -- Straightforward case of incorrect arguments
9697 if not Valid_Boolean_Arg (Typ) then
9698 Error_Msg_N ("invalid operand type for operator&", N);
9699 Set_Etype (N, Any_Type);
9702 -- Special case of probable missing parens
9704 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9705 if Parent_Is_Boolean then
9707 ("operand of not must be enclosed in parentheses",
9711 ("no modular type available in this context", N);
9714 Set_Etype (N, Any_Type);
9717 -- OK resolution of NOT
9720 -- Warn if non-boolean types involved. This is a case like not a < b
9721 -- where a and b are modular, where we will get (not a) < b and most
9722 -- likely not (a < b) was intended.
9724 if Warn_On_Questionable_Missing_Parens
9725 and then not Is_Boolean_Type (Typ)
9726 and then Parent_Is_Boolean
9728 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9731 -- Warn on double negation if checking redundant constructs
9733 if Warn_On_Redundant_Constructs
9734 and then Comes_From_Source (N)
9735 and then Comes_From_Source (Right_Opnd (N))
9736 and then Root_Type (Typ) = Standard_Boolean
9737 and then Nkind (Right_Opnd (N)) = N_Op_Not
9739 Error_Msg_N ("redundant double negation?r?", N);
9742 -- Complete resolution and evaluation of NOT
9744 Resolve (Right_Opnd (N), B_Typ);
9745 Check_Unset_Reference (Right_Opnd (N));
9746 Set_Etype (N, B_Typ);
9747 Generate_Operator_Reference (N, B_Typ);
9752 -----------------------------
9753 -- Resolve_Operator_Symbol --
9754 -----------------------------
9756 -- Nothing to be done, all resolved already
9758 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9759 pragma Warnings (Off, N);
9760 pragma Warnings (Off, Typ);
9764 end Resolve_Operator_Symbol;
9766 ----------------------------------
9767 -- Resolve_Qualified_Expression --
9768 ----------------------------------
9770 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9771 pragma Warnings (Off, Typ);
9773 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9774 Expr : constant Node_Id := Expression (N);
9777 Resolve (Expr, Target_Typ);
9779 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9780 -- operation if not needed.
9782 if Restriction_Check_Required (SPARK_05)
9783 and then Is_Array_Type (Target_Typ)
9784 and then Is_Array_Type (Etype (Expr))
9785 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9786 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9788 Check_SPARK_05_Restriction
9789 ("array types should have matching static bounds", N);
9792 -- A qualified expression requires an exact match of the type, class-
9793 -- wide matching is not allowed. However, if the qualifying type is
9794 -- specific and the expression has a class-wide type, it may still be
9795 -- okay, since it can be the result of the expansion of a call to a
9796 -- dispatching function, so we also have to check class-wideness of the
9797 -- type of the expression's original node.
9799 if (Is_Class_Wide_Type (Target_Typ)
9801 (Is_Class_Wide_Type (Etype (Expr))
9802 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9803 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9805 Wrong_Type (Expr, Target_Typ);
9808 -- If the target type is unconstrained, then we reset the type of the
9809 -- result from the type of the expression. For other cases, the actual
9810 -- subtype of the expression is the target type.
9812 if Is_Composite_Type (Target_Typ)
9813 and then not Is_Constrained (Target_Typ)
9815 Set_Etype (N, Etype (Expr));
9818 Analyze_Dimension (N);
9819 Eval_Qualified_Expression (N);
9821 -- If we still have a qualified expression after the static evaluation,
9822 -- then apply a scalar range check if needed. The reason that we do this
9823 -- after the Eval call is that otherwise, the application of the range
9824 -- check may convert an illegal static expression and result in warning
9825 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9827 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9828 Apply_Scalar_Range_Check (Expr, Typ);
9831 -- Finally, check whether a predicate applies to the target type. This
9832 -- comes from AI12-0100. As for type conversions, check the enclosing
9833 -- context to prevent an infinite expansion.
9835 if Has_Predicates (Target_Typ) then
9836 if Nkind (Parent (N)) = N_Function_Call
9837 and then Present (Name (Parent (N)))
9838 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
9840 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
9844 -- In the case of a qualified expression in an allocator, the check
9845 -- is applied when expanding the allocator, so avoid redundant check.
9847 elsif Nkind (N) = N_Qualified_Expression
9848 and then Nkind (Parent (N)) /= N_Allocator
9850 Apply_Predicate_Check (N, Target_Typ);
9853 end Resolve_Qualified_Expression;
9855 ------------------------------
9856 -- Resolve_Raise_Expression --
9857 ------------------------------
9859 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9861 if Typ = Raise_Type then
9862 Error_Msg_N ("cannot find unique type for raise expression", N);
9863 Set_Etype (N, Any_Type);
9867 end Resolve_Raise_Expression;
9873 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9874 L : constant Node_Id := Low_Bound (N);
9875 H : constant Node_Id := High_Bound (N);
9877 function First_Last_Ref return Boolean;
9878 -- Returns True if N is of the form X'First .. X'Last where X is the
9879 -- same entity for both attributes.
9881 --------------------
9882 -- First_Last_Ref --
9883 --------------------
9885 function First_Last_Ref return Boolean is
9886 Lorig : constant Node_Id := Original_Node (L);
9887 Horig : constant Node_Id := Original_Node (H);
9890 if Nkind (Lorig) = N_Attribute_Reference
9891 and then Nkind (Horig) = N_Attribute_Reference
9892 and then Attribute_Name (Lorig) = Name_First
9893 and then Attribute_Name (Horig) = Name_Last
9896 PL : constant Node_Id := Prefix (Lorig);
9897 PH : constant Node_Id := Prefix (Horig);
9899 if Is_Entity_Name (PL)
9900 and then Is_Entity_Name (PH)
9901 and then Entity (PL) = Entity (PH)
9911 -- Start of processing for Resolve_Range
9916 -- The lower bound should be in Typ. The higher bound can be in Typ's
9917 -- base type if the range is null. It may still be invalid if it is
9918 -- higher than the lower bound. This is checked later in the context in
9919 -- which the range appears.
9922 Resolve (H, Base_Type (Typ));
9924 -- Reanalyze the lower bound after both bounds have been analyzed, so
9925 -- that the range is known to be static or not by now. This may trigger
9926 -- more compile-time evaluation, which is useful for static analysis
9927 -- with GNATprove. This is not needed for compilation or static analysis
9928 -- with CodePeer, as full expansion does that evaluation then.
9930 if GNATprove_Mode then
9931 Set_Analyzed (L, False);
9935 -- Check for inappropriate range on unordered enumeration type
9937 if Bad_Unordered_Enumeration_Reference (N, Typ)
9939 -- Exclude X'First .. X'Last if X is the same entity for both
9941 and then not First_Last_Ref
9943 Error_Msg_Sloc := Sloc (Typ);
9945 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9948 Check_Unset_Reference (L);
9949 Check_Unset_Reference (H);
9951 -- We have to check the bounds for being within the base range as
9952 -- required for a non-static context. Normally this is automatic and
9953 -- done as part of evaluating expressions, but the N_Range node is an
9954 -- exception, since in GNAT we consider this node to be a subexpression,
9955 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9956 -- this, but that would put the test on the main evaluation path for
9959 Check_Non_Static_Context (L);
9960 Check_Non_Static_Context (H);
9962 -- Check for an ambiguous range over character literals. This will
9963 -- happen with a membership test involving only literals.
9965 if Typ = Any_Character then
9966 Ambiguous_Character (L);
9967 Set_Etype (N, Any_Type);
9971 -- If bounds are static, constant-fold them, so size computations are
9972 -- identical between front-end and back-end. Do not perform this
9973 -- transformation while analyzing generic units, as type information
9974 -- would be lost when reanalyzing the constant node in the instance.
9976 if Is_Discrete_Type (Typ) and then Expander_Active then
9977 if Is_OK_Static_Expression (L) then
9978 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9981 if Is_OK_Static_Expression (H) then
9982 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9987 --------------------------
9988 -- Resolve_Real_Literal --
9989 --------------------------
9991 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9992 Actual_Typ : constant Entity_Id := Etype (N);
9995 -- Special processing for fixed-point literals to make sure that the
9996 -- value is an exact multiple of small where this is required. We skip
9997 -- this for the universal real case, and also for generic types.
9999 if Is_Fixed_Point_Type (Typ)
10000 and then Typ /= Universal_Fixed
10001 and then Typ /= Any_Fixed
10002 and then not Is_Generic_Type (Typ)
10005 Val : constant Ureal := Realval (N);
10006 Cintr : constant Ureal := Val / Small_Value (Typ);
10007 Cint : constant Uint := UR_Trunc (Cintr);
10008 Den : constant Uint := Norm_Den (Cintr);
10012 -- Case of literal is not an exact multiple of the Small
10016 -- For a source program literal for a decimal fixed-point type,
10017 -- this is statically illegal (RM 4.9(36)).
10019 if Is_Decimal_Fixed_Point_Type (Typ)
10020 and then Actual_Typ = Universal_Real
10021 and then Comes_From_Source (N)
10023 Error_Msg_N ("value has extraneous low order digits", N);
10026 -- Generate a warning if literal from source
10028 if Is_OK_Static_Expression (N)
10029 and then Warn_On_Bad_Fixed_Value
10032 ("?b?static fixed-point value is not a multiple of Small!",
10036 -- Replace literal by a value that is the exact representation
10037 -- of a value of the type, i.e. a multiple of the small value,
10038 -- by truncation, since Machine_Rounds is false for all GNAT
10039 -- fixed-point types (RM 4.9(38)).
10041 Stat := Is_OK_Static_Expression (N);
10043 Make_Real_Literal (Sloc (N),
10044 Realval => Small_Value (Typ) * Cint));
10046 Set_Is_Static_Expression (N, Stat);
10049 -- In all cases, set the corresponding integer field
10051 Set_Corresponding_Integer_Value (N, Cint);
10055 -- Now replace the actual type by the expected type as usual
10057 Set_Etype (N, Typ);
10058 Eval_Real_Literal (N);
10059 end Resolve_Real_Literal;
10061 -----------------------
10062 -- Resolve_Reference --
10063 -----------------------
10065 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
10066 P : constant Node_Id := Prefix (N);
10069 -- Replace general access with specific type
10071 if Ekind (Etype (N)) = E_Allocator_Type then
10072 Set_Etype (N, Base_Type (Typ));
10075 Resolve (P, Designated_Type (Etype (N)));
10077 -- If we are taking the reference of a volatile entity, then treat it as
10078 -- a potential modification of this entity. This is too conservative,
10079 -- but necessary because remove side effects can cause transformations
10080 -- of normal assignments into reference sequences that otherwise fail to
10081 -- notice the modification.
10083 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
10084 Note_Possible_Modification (P, Sure => False);
10086 end Resolve_Reference;
10088 --------------------------------
10089 -- Resolve_Selected_Component --
10090 --------------------------------
10092 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
10094 Comp1 : Entity_Id := Empty; -- prevent junk warning
10095 P : constant Node_Id := Prefix (N);
10096 S : constant Node_Id := Selector_Name (N);
10097 T : Entity_Id := Etype (P);
10099 I1 : Interp_Index := 0; -- prevent junk warning
10104 function Init_Component return Boolean;
10105 -- Check whether this is the initialization of a component within an
10106 -- init proc (by assignment or call to another init proc). If true,
10107 -- there is no need for a discriminant check.
10109 --------------------
10110 -- Init_Component --
10111 --------------------
10113 function Init_Component return Boolean is
10115 return Inside_Init_Proc
10116 and then Nkind (Prefix (N)) = N_Identifier
10117 and then Chars (Prefix (N)) = Name_uInit
10118 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
10119 end Init_Component;
10121 -- Start of processing for Resolve_Selected_Component
10124 if Is_Overloaded (P) then
10126 -- Use the context type to select the prefix that has a selector
10127 -- of the correct name and type.
10130 Get_First_Interp (P, I, It);
10132 Search : while Present (It.Typ) loop
10133 if Is_Access_Type (It.Typ) then
10134 T := Designated_Type (It.Typ);
10139 -- Locate selected component. For a private prefix the selector
10140 -- can denote a discriminant.
10142 if Is_Record_Type (T) or else Is_Private_Type (T) then
10144 -- The visible components of a class-wide type are those of
10147 if Is_Class_Wide_Type (T) then
10151 Comp := First_Entity (T);
10152 while Present (Comp) loop
10153 if Chars (Comp) = Chars (S)
10154 and then Covers (Typ, Etype (Comp))
10163 It := Disambiguate (P, I1, I, Any_Type);
10165 if It = No_Interp then
10167 ("ambiguous prefix for selected component", N);
10168 Set_Etype (N, Typ);
10174 -- There may be an implicit dereference. Retrieve
10175 -- designated record type.
10177 if Is_Access_Type (It1.Typ) then
10178 T := Designated_Type (It1.Typ);
10183 if Scope (Comp1) /= T then
10185 -- Resolution chooses the new interpretation.
10186 -- Find the component with the right name.
10188 Comp1 := First_Entity (T);
10189 while Present (Comp1)
10190 and then Chars (Comp1) /= Chars (S)
10192 Comp1 := Next_Entity (Comp1);
10201 Comp := Next_Entity (Comp);
10205 Get_Next_Interp (I, It);
10208 -- There must be a legal interpretation at this point
10210 pragma Assert (Found);
10211 Resolve (P, It1.Typ);
10212 Set_Etype (N, Typ);
10213 Set_Entity_With_Checks (S, Comp1);
10215 -- The type of the context and that of the component are
10216 -- compatible and in general identical, but if they are anonymous
10217 -- access-to-subprogram types, the relevant type is that of the
10218 -- component. This matters in Unnest_Subprograms mode, where the
10219 -- relevant context is the one in which the type is declared, not
10220 -- the point of use. This determines what activation record to use.
10222 if Ekind (Typ) = E_Anonymous_Access_Subprogram_Type then
10223 Set_Etype (N, Etype (Comp1));
10227 -- Resolve prefix with its type
10232 -- Generate cross-reference. We needed to wait until full overloading
10233 -- resolution was complete to do this, since otherwise we can't tell if
10234 -- we are an lvalue or not.
10236 if May_Be_Lvalue (N) then
10237 Generate_Reference (Entity (S), S, 'm');
10239 Generate_Reference (Entity (S), S, 'r');
10242 -- If prefix is an access type, the node will be transformed into an
10243 -- explicit dereference during expansion. The type of the node is the
10244 -- designated type of that of the prefix.
10246 if Is_Access_Type (Etype (P)) then
10247 T := Designated_Type (Etype (P));
10248 Check_Fully_Declared_Prefix (T, P);
10253 -- Set flag for expander if discriminant check required on a component
10254 -- appearing within a variant.
10256 if Has_Discriminants (T)
10257 and then Ekind (Entity (S)) = E_Component
10258 and then Present (Original_Record_Component (Entity (S)))
10259 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
10261 Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
10262 and then not Discriminant_Checks_Suppressed (T)
10263 and then not Init_Component
10265 Set_Do_Discriminant_Check (N);
10268 if Ekind (Entity (S)) = E_Void then
10269 Error_Msg_N ("premature use of component", S);
10272 -- If the prefix is a record conversion, this may be a renamed
10273 -- discriminant whose bounds differ from those of the original
10274 -- one, so we must ensure that a range check is performed.
10276 if Nkind (P) = N_Type_Conversion
10277 and then Ekind (Entity (S)) = E_Discriminant
10278 and then Is_Discrete_Type (Typ)
10280 Set_Etype (N, Base_Type (Typ));
10283 -- Note: No Eval processing is required, because the prefix is of a
10284 -- record type, or protected type, and neither can possibly be static.
10286 -- If the record type is atomic, and the component is non-atomic, then
10287 -- this is worth a warning, since we have a situation where the access
10288 -- to the component may cause extra read/writes of the atomic array
10289 -- object, or partial word accesses, both of which may be unexpected.
10291 if Nkind (N) = N_Selected_Component
10292 and then Is_Atomic_Ref_With_Address (N)
10293 and then not Is_Atomic (Entity (S))
10294 and then not Is_Atomic (Etype (Entity (S)))
10297 ("??access to non-atomic component of atomic record",
10300 ("\??may cause unexpected accesses to atomic object",
10304 Analyze_Dimension (N);
10305 end Resolve_Selected_Component;
10307 -------------------
10308 -- Resolve_Shift --
10309 -------------------
10311 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
10312 B_Typ : constant Entity_Id := Base_Type (Typ);
10313 L : constant Node_Id := Left_Opnd (N);
10314 R : constant Node_Id := Right_Opnd (N);
10317 -- We do the resolution using the base type, because intermediate values
10318 -- in expressions always are of the base type, not a subtype of it.
10320 Resolve (L, B_Typ);
10321 Resolve (R, Standard_Natural);
10323 Check_Unset_Reference (L);
10324 Check_Unset_Reference (R);
10326 Set_Etype (N, B_Typ);
10327 Generate_Operator_Reference (N, B_Typ);
10331 ---------------------------
10332 -- Resolve_Short_Circuit --
10333 ---------------------------
10335 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
10336 B_Typ : constant Entity_Id := Base_Type (Typ);
10337 L : constant Node_Id := Left_Opnd (N);
10338 R : constant Node_Id := Right_Opnd (N);
10341 -- Ensure all actions associated with the left operand (e.g.
10342 -- finalization of transient objects) are fully evaluated locally within
10343 -- an expression with actions. This is particularly helpful for coverage
10344 -- analysis. However this should not happen in generics or if option
10345 -- Minimize_Expression_With_Actions is set.
10347 if Expander_Active and not Minimize_Expression_With_Actions then
10349 Reloc_L : constant Node_Id := Relocate_Node (L);
10351 Save_Interps (Old_N => L, New_N => Reloc_L);
10354 Make_Expression_With_Actions (Sloc (L),
10355 Actions => New_List,
10356 Expression => Reloc_L));
10358 -- Set Comes_From_Source on L to preserve warnings for unset
10361 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
10365 Resolve (L, B_Typ);
10366 Resolve (R, B_Typ);
10368 -- Check for issuing warning for always False assert/check, this happens
10369 -- when assertions are turned off, in which case the pragma Assert/Check
10370 -- was transformed into:
10372 -- if False and then <condition> then ...
10374 -- and we detect this pattern
10376 if Warn_On_Assertion_Failure
10377 and then Is_Entity_Name (R)
10378 and then Entity (R) = Standard_False
10379 and then Nkind (Parent (N)) = N_If_Statement
10380 and then Nkind (N) = N_And_Then
10381 and then Is_Entity_Name (L)
10382 and then Entity (L) = Standard_False
10385 Orig : constant Node_Id := Original_Node (Parent (N));
10388 -- Special handling of Asssert pragma
10390 if Nkind (Orig) = N_Pragma
10391 and then Pragma_Name (Orig) = Name_Assert
10394 Expr : constant Node_Id :=
10397 (First (Pragma_Argument_Associations (Orig))));
10400 -- Don't warn if original condition is explicit False,
10401 -- since obviously the failure is expected in this case.
10403 if Is_Entity_Name (Expr)
10404 and then Entity (Expr) = Standard_False
10408 -- Issue warning. We do not want the deletion of the
10409 -- IF/AND-THEN to take this message with it. We achieve this
10410 -- by making sure that the expanded code points to the Sloc
10411 -- of the expression, not the original pragma.
10414 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10415 -- The source location of the expression is not usually
10416 -- the best choice here. For example, it gets located on
10417 -- the last AND keyword in a chain of boolean expressiond
10418 -- AND'ed together. It is best to put the message on the
10419 -- first character of the assertion, which is the effect
10420 -- of the First_Node call here.
10423 ("?A?assertion would fail at run time!",
10425 (First (Pragma_Argument_Associations (Orig))));
10429 -- Similar processing for Check pragma
10431 elsif Nkind (Orig) = N_Pragma
10432 and then Pragma_Name (Orig) = Name_Check
10434 -- Don't want to warn if original condition is explicit False
10437 Expr : constant Node_Id :=
10440 (Next (First (Pragma_Argument_Associations (Orig)))));
10442 if Is_Entity_Name (Expr)
10443 and then Entity (Expr) = Standard_False
10450 -- Again use Error_Msg_F rather than Error_Msg_N, see
10451 -- comment above for an explanation of why we do this.
10454 ("?A?check would fail at run time!",
10456 (Last (Pragma_Argument_Associations (Orig))));
10463 -- Continue with processing of short circuit
10465 Check_Unset_Reference (L);
10466 Check_Unset_Reference (R);
10468 Set_Etype (N, B_Typ);
10469 Eval_Short_Circuit (N);
10470 end Resolve_Short_Circuit;
10472 -------------------
10473 -- Resolve_Slice --
10474 -------------------
10476 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10477 Drange : constant Node_Id := Discrete_Range (N);
10478 Name : constant Node_Id := Prefix (N);
10479 Array_Type : Entity_Id := Empty;
10480 Dexpr : Node_Id := Empty;
10481 Index_Type : Entity_Id;
10484 if Is_Overloaded (Name) then
10486 -- Use the context type to select the prefix that yields the correct
10491 I1 : Interp_Index := 0;
10493 P : constant Node_Id := Prefix (N);
10494 Found : Boolean := False;
10497 Get_First_Interp (P, I, It);
10498 while Present (It.Typ) loop
10499 if (Is_Array_Type (It.Typ)
10500 and then Covers (Typ, It.Typ))
10501 or else (Is_Access_Type (It.Typ)
10502 and then Is_Array_Type (Designated_Type (It.Typ))
10503 and then Covers (Typ, Designated_Type (It.Typ)))
10506 It := Disambiguate (P, I1, I, Any_Type);
10508 if It = No_Interp then
10509 Error_Msg_N ("ambiguous prefix for slicing", N);
10510 Set_Etype (N, Typ);
10514 Array_Type := It.Typ;
10519 Array_Type := It.Typ;
10524 Get_Next_Interp (I, It);
10529 Array_Type := Etype (Name);
10532 Resolve (Name, Array_Type);
10534 if Is_Access_Type (Array_Type) then
10535 Apply_Access_Check (N);
10536 Array_Type := Designated_Type (Array_Type);
10538 -- If the prefix is an access to an unconstrained array, we must use
10539 -- the actual subtype of the object to perform the index checks. The
10540 -- object denoted by the prefix is implicit in the node, so we build
10541 -- an explicit representation for it in order to compute the actual
10544 if not Is_Constrained (Array_Type) then
10545 Remove_Side_Effects (Prefix (N));
10548 Obj : constant Node_Id :=
10549 Make_Explicit_Dereference (Sloc (N),
10550 Prefix => New_Copy_Tree (Prefix (N)));
10552 Set_Etype (Obj, Array_Type);
10553 Set_Parent (Obj, Parent (N));
10554 Array_Type := Get_Actual_Subtype (Obj);
10558 elsif Is_Entity_Name (Name)
10559 or else Nkind (Name) = N_Explicit_Dereference
10560 or else (Nkind (Name) = N_Function_Call
10561 and then not Is_Constrained (Etype (Name)))
10563 Array_Type := Get_Actual_Subtype (Name);
10565 -- If the name is a selected component that depends on discriminants,
10566 -- build an actual subtype for it. This can happen only when the name
10567 -- itself is overloaded; otherwise the actual subtype is created when
10568 -- the selected component is analyzed.
10570 elsif Nkind (Name) = N_Selected_Component
10571 and then Full_Analysis
10572 and then Depends_On_Discriminant (First_Index (Array_Type))
10575 Act_Decl : constant Node_Id :=
10576 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10578 Insert_Action (N, Act_Decl);
10579 Array_Type := Defining_Identifier (Act_Decl);
10582 -- Maybe this should just be "else", instead of checking for the
10583 -- specific case of slice??? This is needed for the case where the
10584 -- prefix is an Image attribute, which gets expanded to a slice, and so
10585 -- has a constrained subtype which we want to use for the slice range
10586 -- check applied below (the range check won't get done if the
10587 -- unconstrained subtype of the 'Image is used).
10589 elsif Nkind (Name) = N_Slice then
10590 Array_Type := Etype (Name);
10593 -- Obtain the type of the array index
10595 if Ekind (Array_Type) = E_String_Literal_Subtype then
10596 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10598 Index_Type := Etype (First_Index (Array_Type));
10601 -- If name was overloaded, set slice type correctly now
10603 Set_Etype (N, Array_Type);
10605 -- Handle the generation of a range check that compares the array index
10606 -- against the discrete_range. The check is not applied to internally
10607 -- built nodes associated with the expansion of dispatch tables. Check
10608 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10611 if Tagged_Type_Expansion
10612 and then RTU_Loaded (Ada_Tags)
10613 and then Nkind (Prefix (N)) = N_Selected_Component
10614 and then Present (Entity (Selector_Name (Prefix (N))))
10615 and then Entity (Selector_Name (Prefix (N))) =
10616 RTE_Record_Component (RE_Prims_Ptr)
10620 -- The discrete_range is specified by a subtype indication. Create a
10621 -- shallow copy and inherit the type, parent and source location from
10622 -- the discrete_range. This ensures that the range check is inserted
10623 -- relative to the slice and that the runtime exception points to the
10624 -- proper construct.
10626 elsif Is_Entity_Name (Drange) then
10627 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10629 Set_Etype (Dexpr, Etype (Drange));
10630 Set_Parent (Dexpr, Parent (Drange));
10631 Set_Sloc (Dexpr, Sloc (Drange));
10633 -- The discrete_range is a regular range. Resolve the bounds and remove
10634 -- their side effects.
10637 Resolve (Drange, Base_Type (Index_Type));
10639 if Nkind (Drange) = N_Range then
10640 Force_Evaluation (Low_Bound (Drange));
10641 Force_Evaluation (High_Bound (Drange));
10647 if Present (Dexpr) then
10648 Apply_Range_Check (Dexpr, Index_Type);
10651 Set_Slice_Subtype (N);
10653 -- Check bad use of type with predicates
10659 if Nkind (Drange) = N_Subtype_Indication
10660 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10662 Subt := Entity (Subtype_Mark (Drange));
10664 Subt := Etype (Drange);
10667 if Has_Predicates (Subt) then
10668 Bad_Predicated_Subtype_Use
10669 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10673 -- Otherwise here is where we check suspicious indexes
10675 if Nkind (Drange) = N_Range then
10676 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10677 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10680 Analyze_Dimension (N);
10684 ----------------------------
10685 -- Resolve_String_Literal --
10686 ----------------------------
10688 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10689 C_Typ : constant Entity_Id := Component_Type (Typ);
10690 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10691 Loc : constant Source_Ptr := Sloc (N);
10692 Str : constant String_Id := Strval (N);
10693 Strlen : constant Nat := String_Length (Str);
10694 Subtype_Id : Entity_Id;
10695 Need_Check : Boolean;
10698 -- For a string appearing in a concatenation, defer creation of the
10699 -- string_literal_subtype until the end of the resolution of the
10700 -- concatenation, because the literal may be constant-folded away. This
10701 -- is a useful optimization for long concatenation expressions.
10703 -- If the string is an aggregate built for a single character (which
10704 -- happens in a non-static context) or a is null string to which special
10705 -- checks may apply, we build the subtype. Wide strings must also get a
10706 -- string subtype if they come from a one character aggregate. Strings
10707 -- generated by attributes might be static, but it is often hard to
10708 -- determine whether the enclosing context is static, so we generate
10709 -- subtypes for them as well, thus losing some rarer optimizations ???
10710 -- Same for strings that come from a static conversion.
10713 (Strlen = 0 and then Typ /= Standard_String)
10714 or else Nkind (Parent (N)) /= N_Op_Concat
10715 or else (N /= Left_Opnd (Parent (N))
10716 and then N /= Right_Opnd (Parent (N)))
10717 or else ((Typ = Standard_Wide_String
10718 or else Typ = Standard_Wide_Wide_String)
10719 and then Nkind (Original_Node (N)) /= N_String_Literal);
10721 -- If the resolving type is itself a string literal subtype, we can just
10722 -- reuse it, since there is no point in creating another.
10724 if Ekind (Typ) = E_String_Literal_Subtype then
10727 elsif Nkind (Parent (N)) = N_Op_Concat
10728 and then not Need_Check
10729 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10730 N_Attribute_Reference,
10731 N_Qualified_Expression,
10736 -- Do not generate a string literal subtype for the default expression
10737 -- of a formal parameter in GNATprove mode. This is because the string
10738 -- subtype is associated with the freezing actions of the subprogram,
10739 -- however freezing is disabled in GNATprove mode and as a result the
10740 -- subtype is unavailable.
10742 elsif GNATprove_Mode
10743 and then Nkind (Parent (N)) = N_Parameter_Specification
10747 -- Otherwise we must create a string literal subtype. Note that the
10748 -- whole idea of string literal subtypes is simply to avoid the need
10749 -- for building a full fledged array subtype for each literal.
10752 Set_String_Literal_Subtype (N, Typ);
10753 Subtype_Id := Etype (N);
10756 if Nkind (Parent (N)) /= N_Op_Concat
10759 Set_Etype (N, Subtype_Id);
10760 Eval_String_Literal (N);
10763 if Is_Limited_Composite (Typ)
10764 or else Is_Private_Composite (Typ)
10766 Error_Msg_N ("string literal not available for private array", N);
10767 Set_Etype (N, Any_Type);
10771 -- The validity of a null string has been checked in the call to
10772 -- Eval_String_Literal.
10777 -- Always accept string literal with component type Any_Character, which
10778 -- occurs in error situations and in comparisons of literals, both of
10779 -- which should accept all literals.
10781 elsif R_Typ = Any_Character then
10784 -- If the type is bit-packed, then we always transform the string
10785 -- literal into a full fledged aggregate.
10787 elsif Is_Bit_Packed_Array (Typ) then
10790 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10793 -- For Standard.Wide_Wide_String, or any other type whose component
10794 -- type is Standard.Wide_Wide_Character, we know that all the
10795 -- characters in the string must be acceptable, since the parser
10796 -- accepted the characters as valid character literals.
10798 if R_Typ = Standard_Wide_Wide_Character then
10801 -- For the case of Standard.String, or any other type whose component
10802 -- type is Standard.Character, we must make sure that there are no
10803 -- wide characters in the string, i.e. that it is entirely composed
10804 -- of characters in range of type Character.
10806 -- If the string literal is the result of a static concatenation, the
10807 -- test has already been performed on the components, and need not be
10810 elsif R_Typ = Standard_Character
10811 and then Nkind (Original_Node (N)) /= N_Op_Concat
10813 for J in 1 .. Strlen loop
10814 if not In_Character_Range (Get_String_Char (Str, J)) then
10816 -- If we are out of range, post error. This is one of the
10817 -- very few places that we place the flag in the middle of
10818 -- a token, right under the offending wide character. Not
10819 -- quite clear if this is right wrt wide character encoding
10820 -- sequences, but it's only an error message.
10823 ("literal out of range of type Standard.Character",
10824 Source_Ptr (Int (Loc) + J));
10829 -- For the case of Standard.Wide_String, or any other type whose
10830 -- component type is Standard.Wide_Character, we must make sure that
10831 -- there are no wide characters in the string, i.e. that it is
10832 -- entirely composed of characters in range of type Wide_Character.
10834 -- If the string literal is the result of a static concatenation,
10835 -- the test has already been performed on the components, and need
10836 -- not be repeated.
10838 elsif R_Typ = Standard_Wide_Character
10839 and then Nkind (Original_Node (N)) /= N_Op_Concat
10841 for J in 1 .. Strlen loop
10842 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10844 -- If we are out of range, post error. This is one of the
10845 -- very few places that we place the flag in the middle of
10846 -- a token, right under the offending wide character.
10848 -- This is not quite right, because characters in general
10849 -- will take more than one character position ???
10852 ("literal out of range of type Standard.Wide_Character",
10853 Source_Ptr (Int (Loc) + J));
10858 -- If the root type is not a standard character, then we will convert
10859 -- the string into an aggregate and will let the aggregate code do
10860 -- the checking. Standard Wide_Wide_Character is also OK here.
10866 -- See if the component type of the array corresponding to the string
10867 -- has compile time known bounds. If yes we can directly check
10868 -- whether the evaluation of the string will raise constraint error.
10869 -- Otherwise we need to transform the string literal into the
10870 -- corresponding character aggregate and let the aggregate code do
10871 -- the checking. We use the same transformation if the component
10872 -- type has a static predicate, which will be applied to each
10873 -- character when the aggregate is resolved.
10875 if Is_Standard_Character_Type (R_Typ) then
10877 -- Check for the case of full range, where we are definitely OK
10879 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10883 -- Here the range is not the complete base type range, so check
10886 Comp_Typ_Lo : constant Node_Id :=
10887 Type_Low_Bound (Component_Type (Typ));
10888 Comp_Typ_Hi : constant Node_Id :=
10889 Type_High_Bound (Component_Type (Typ));
10894 if Compile_Time_Known_Value (Comp_Typ_Lo)
10895 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10897 for J in 1 .. Strlen loop
10898 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10900 if Char_Val < Expr_Value (Comp_Typ_Lo)
10901 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10903 Apply_Compile_Time_Constraint_Error
10904 (N, "character out of range??",
10905 CE_Range_Check_Failed,
10906 Loc => Source_Ptr (Int (Loc) + J));
10910 if not Has_Static_Predicate (C_Typ) then
10918 -- If we got here we meed to transform the string literal into the
10919 -- equivalent qualified positional array aggregate. This is rather
10920 -- heavy artillery for this situation, but it is hard work to avoid.
10923 Lits : constant List_Id := New_List;
10924 P : Source_Ptr := Loc + 1;
10928 -- Build the character literals, we give them source locations that
10929 -- correspond to the string positions, which is a bit tricky given
10930 -- the possible presence of wide character escape sequences.
10932 for J in 1 .. Strlen loop
10933 C := Get_String_Char (Str, J);
10934 Set_Character_Literal_Name (C);
10937 Make_Character_Literal (P,
10938 Chars => Name_Find,
10939 Char_Literal_Value => UI_From_CC (C)));
10941 if In_Character_Range (C) then
10944 -- Should we have a call to Skip_Wide here ???
10953 Make_Qualified_Expression (Loc,
10954 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10956 Make_Aggregate (Loc, Expressions => Lits)));
10958 Analyze_And_Resolve (N, Typ);
10960 end Resolve_String_Literal;
10962 -------------------------
10963 -- Resolve_Target_Name --
10964 -------------------------
10966 procedure Resolve_Target_Name (N : Node_Id; Typ : Entity_Id) is
10968 Set_Etype (N, Typ);
10969 end Resolve_Target_Name;
10971 -----------------------------
10972 -- Resolve_Type_Conversion --
10973 -----------------------------
10975 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10976 Conv_OK : constant Boolean := Conversion_OK (N);
10977 Operand : constant Node_Id := Expression (N);
10978 Operand_Typ : constant Entity_Id := Etype (Operand);
10979 Target_Typ : constant Entity_Id := Etype (N);
10984 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10985 -- Set to False to suppress cases where we want to suppress the test
10986 -- for redundancy to avoid possible false positives on this warning.
10990 and then not Valid_Conversion (N, Target_Typ, Operand)
10995 -- If the Operand Etype is Universal_Fixed, then the conversion is
10996 -- never redundant. We need this check because by the time we have
10997 -- finished the rather complex transformation, the conversion looks
10998 -- redundant when it is not.
11000 if Operand_Typ = Universal_Fixed then
11001 Test_Redundant := False;
11003 -- If the operand is marked as Any_Fixed, then special processing is
11004 -- required. This is also a case where we suppress the test for a
11005 -- redundant conversion, since most certainly it is not redundant.
11007 elsif Operand_Typ = Any_Fixed then
11008 Test_Redundant := False;
11010 -- Mixed-mode operation involving a literal. Context must be a fixed
11011 -- type which is applied to the literal subsequently.
11013 -- Multiplication and division involving two fixed type operands must
11014 -- yield a universal real because the result is computed in arbitrary
11017 if Is_Fixed_Point_Type (Typ)
11018 and then Nkind_In (Operand, N_Op_Divide, N_Op_Multiply)
11019 and then Etype (Left_Opnd (Operand)) = Any_Fixed
11020 and then Etype (Right_Opnd (Operand)) = Any_Fixed
11022 Set_Etype (Operand, Universal_Real);
11024 elsif Is_Numeric_Type (Typ)
11025 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
11026 and then (Etype (Right_Opnd (Operand)) = Universal_Real
11028 Etype (Left_Opnd (Operand)) = Universal_Real)
11030 -- Return if expression is ambiguous
11032 if Unique_Fixed_Point_Type (N) = Any_Type then
11035 -- If nothing else, the available fixed type is Duration
11038 Set_Etype (Operand, Standard_Duration);
11041 -- Resolve the real operand with largest available precision
11043 if Etype (Right_Opnd (Operand)) = Universal_Real then
11044 Rop := New_Copy_Tree (Right_Opnd (Operand));
11046 Rop := New_Copy_Tree (Left_Opnd (Operand));
11049 Resolve (Rop, Universal_Real);
11051 -- If the operand is a literal (it could be a non-static and
11052 -- illegal exponentiation) check whether the use of Duration
11053 -- is potentially inaccurate.
11055 if Nkind (Rop) = N_Real_Literal
11056 and then Realval (Rop) /= Ureal_0
11057 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
11060 ("??universal real operand can only "
11061 & "be interpreted as Duration!", Rop);
11063 ("\??precision will be lost in the conversion!", Rop);
11066 elsif Is_Numeric_Type (Typ)
11067 and then Nkind (Operand) in N_Op
11068 and then Unique_Fixed_Point_Type (N) /= Any_Type
11070 Set_Etype (Operand, Standard_Duration);
11073 Error_Msg_N ("invalid context for mixed mode operation", N);
11074 Set_Etype (Operand, Any_Type);
11081 -- In SPARK, a type conversion between array types should be restricted
11082 -- to types which have matching static bounds.
11084 -- Protect call to Matching_Static_Array_Bounds to avoid costly
11085 -- operation if not needed.
11087 if Restriction_Check_Required (SPARK_05)
11088 and then Is_Array_Type (Target_Typ)
11089 and then Is_Array_Type (Operand_Typ)
11090 and then Operand_Typ /= Any_Composite -- or else Operand in error
11091 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
11093 Check_SPARK_05_Restriction
11094 ("array types should have matching static bounds", N);
11097 -- In formal mode, the operand of an ancestor type conversion must be an
11098 -- object (not an expression).
11100 if Is_Tagged_Type (Target_Typ)
11101 and then not Is_Class_Wide_Type (Target_Typ)
11102 and then Is_Tagged_Type (Operand_Typ)
11103 and then not Is_Class_Wide_Type (Operand_Typ)
11104 and then Is_Ancestor (Target_Typ, Operand_Typ)
11105 and then not Is_SPARK_05_Object_Reference (Operand)
11107 Check_SPARK_05_Restriction ("object required", Operand);
11110 Analyze_Dimension (N);
11112 -- Note: we do the Eval_Type_Conversion call before applying the
11113 -- required checks for a subtype conversion. This is important, since
11114 -- both are prepared under certain circumstances to change the type
11115 -- conversion to a constraint error node, but in the case of
11116 -- Eval_Type_Conversion this may reflect an illegality in the static
11117 -- case, and we would miss the illegality (getting only a warning
11118 -- message), if we applied the type conversion checks first.
11120 Eval_Type_Conversion (N);
11122 -- Even when evaluation is not possible, we may be able to simplify the
11123 -- conversion or its expression. This needs to be done before applying
11124 -- checks, since otherwise the checks may use the original expression
11125 -- and defeat the simplifications. This is specifically the case for
11126 -- elimination of the floating-point Truncation attribute in
11127 -- float-to-int conversions.
11129 Simplify_Type_Conversion (N);
11131 -- If after evaluation we still have a type conversion, then we may need
11132 -- to apply checks required for a subtype conversion.
11134 -- Skip these type conversion checks if universal fixed operands
11135 -- operands involved, since range checks are handled separately for
11136 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
11138 if Nkind (N) = N_Type_Conversion
11139 and then not Is_Generic_Type (Root_Type (Target_Typ))
11140 and then Target_Typ /= Universal_Fixed
11141 and then Operand_Typ /= Universal_Fixed
11143 Apply_Type_Conversion_Checks (N);
11146 -- Issue warning for conversion of simple object to its own type. We
11147 -- have to test the original nodes, since they may have been rewritten
11148 -- by various optimizations.
11150 Orig_N := Original_Node (N);
11152 -- Here we test for a redundant conversion if the warning mode is
11153 -- active (and was not locally reset), and we have a type conversion
11154 -- from source not appearing in a generic instance.
11157 and then Nkind (Orig_N) = N_Type_Conversion
11158 and then Comes_From_Source (Orig_N)
11159 and then not In_Instance
11161 Orig_N := Original_Node (Expression (Orig_N));
11162 Orig_T := Target_Typ;
11164 -- If the node is part of a larger expression, the Target_Type
11165 -- may not be the original type of the node if the context is a
11166 -- condition. Recover original type to see if conversion is needed.
11168 if Is_Boolean_Type (Orig_T)
11169 and then Nkind (Parent (N)) in N_Op
11171 Orig_T := Etype (Parent (N));
11174 -- If we have an entity name, then give the warning if the entity
11175 -- is the right type, or if it is a loop parameter covered by the
11176 -- original type (that's needed because loop parameters have an
11177 -- odd subtype coming from the bounds).
11179 if (Is_Entity_Name (Orig_N)
11181 (Etype (Entity (Orig_N)) = Orig_T
11183 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
11184 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
11186 -- If not an entity, then type of expression must match
11188 or else Etype (Orig_N) = Orig_T
11190 -- One more check, do not give warning if the analyzed conversion
11191 -- has an expression with non-static bounds, and the bounds of the
11192 -- target are static. This avoids junk warnings in cases where the
11193 -- conversion is necessary to establish staticness, for example in
11194 -- a case statement.
11196 if not Is_OK_Static_Subtype (Operand_Typ)
11197 and then Is_OK_Static_Subtype (Target_Typ)
11201 -- Finally, if this type conversion occurs in a context requiring
11202 -- a prefix, and the expression is a qualified expression then the
11203 -- type conversion is not redundant, since a qualified expression
11204 -- is not a prefix, whereas a type conversion is. For example, "X
11205 -- := T'(Funx(...)).Y;" is illegal because a selected component
11206 -- requires a prefix, but a type conversion makes it legal: "X :=
11207 -- T(T'(Funx(...))).Y;"
11209 -- In Ada 2012, a qualified expression is a name, so this idiom is
11210 -- no longer needed, but we still suppress the warning because it
11211 -- seems unfriendly for warnings to pop up when you switch to the
11212 -- newer language version.
11214 elsif Nkind (Orig_N) = N_Qualified_Expression
11215 and then Nkind_In (Parent (N), N_Attribute_Reference,
11216 N_Indexed_Component,
11217 N_Selected_Component,
11219 N_Explicit_Dereference)
11223 -- Never warn on conversion to Long_Long_Integer'Base since
11224 -- that is most likely an artifact of the extended overflow
11225 -- checking and comes from complex expanded code.
11227 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
11230 -- Here we give the redundant conversion warning. If it is an
11231 -- entity, give the name of the entity in the message. If not,
11232 -- just mention the expression.
11234 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
11237 if Is_Entity_Name (Orig_N) then
11238 Error_Msg_Node_2 := Orig_T;
11239 Error_Msg_NE -- CODEFIX
11240 ("??redundant conversion, & is of type &!",
11241 N, Entity (Orig_N));
11244 ("??redundant conversion, expression is of type&!",
11251 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
11252 -- No need to perform any interface conversion if the type of the
11253 -- expression coincides with the target type.
11255 if Ada_Version >= Ada_2005
11256 and then Expander_Active
11257 and then Operand_Typ /= Target_Typ
11260 Opnd : Entity_Id := Operand_Typ;
11261 Target : Entity_Id := Target_Typ;
11264 -- If the type of the operand is a limited view, use nonlimited
11265 -- view when available. If it is a class-wide type, recover the
11266 -- class-wide type of the nonlimited view.
11268 if From_Limited_With (Opnd)
11269 and then Has_Non_Limited_View (Opnd)
11271 Opnd := Non_Limited_View (Opnd);
11272 Set_Etype (Expression (N), Opnd);
11275 if Is_Access_Type (Opnd) then
11276 Opnd := Designated_Type (Opnd);
11279 if Is_Access_Type (Target_Typ) then
11280 Target := Designated_Type (Target);
11283 if Opnd = Target then
11286 -- Conversion from interface type
11288 elsif Is_Interface (Opnd) then
11290 -- Ada 2005 (AI-217): Handle entities from limited views
11292 if From_Limited_With (Opnd) then
11293 Error_Msg_Qual_Level := 99;
11294 Error_Msg_NE -- CODEFIX
11295 ("missing WITH clause on package &", N,
11296 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
11298 ("type conversions require visibility of the full view",
11301 elsif From_Limited_With (Target)
11303 (Is_Access_Type (Target_Typ)
11304 and then Present (Non_Limited_View (Etype (Target))))
11306 Error_Msg_Qual_Level := 99;
11307 Error_Msg_NE -- CODEFIX
11308 ("missing WITH clause on package &", N,
11309 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
11311 ("type conversions require visibility of the full view",
11315 Expand_Interface_Conversion (N);
11318 -- Conversion to interface type
11320 elsif Is_Interface (Target) then
11324 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
11325 Opnd := Etype (Opnd);
11328 if Is_Class_Wide_Type (Opnd)
11329 or else Interface_Present_In_Ancestor
11333 Expand_Interface_Conversion (N);
11335 Error_Msg_Name_1 := Chars (Etype (Target));
11336 Error_Msg_Name_2 := Chars (Opnd);
11338 ("wrong interface conversion (% is not a progenitor "
11345 -- Ada 2012: once the type conversion is resolved, check whether the
11346 -- operand statisfies the static predicate of the target type.
11348 if Has_Predicates (Target_Typ) then
11349 Check_Expression_Against_Static_Predicate (N, Target_Typ);
11352 -- If at this stage we have a real to integer conversion, make sure that
11353 -- the Do_Range_Check flag is set, because such conversions in general
11354 -- need a range check. We only need this if expansion is off.
11355 -- In GNATprove mode, we only do that when converting from fixed-point
11356 -- (as floating-point to integer conversions are now handled in
11357 -- GNATprove mode).
11359 if Nkind (N) = N_Type_Conversion
11360 and then not Expander_Active
11361 and then Is_Integer_Type (Target_Typ)
11362 and then (Is_Fixed_Point_Type (Operand_Typ)
11363 or else (not GNATprove_Mode
11364 and then Is_Floating_Point_Type (Operand_Typ)))
11366 Set_Do_Range_Check (Operand);
11369 -- Generating C code a type conversion of an access to constrained
11370 -- array type to access to unconstrained array type involves building
11371 -- a fat pointer which in general cannot be generated on the fly. We
11372 -- remove side effects in order to store the result of the conversion
11373 -- into a temporary.
11375 if Modify_Tree_For_C
11376 and then Nkind (N) = N_Type_Conversion
11377 and then Nkind (Parent (N)) /= N_Object_Declaration
11378 and then Is_Access_Type (Etype (N))
11379 and then Is_Array_Type (Designated_Type (Etype (N)))
11380 and then not Is_Constrained (Designated_Type (Etype (N)))
11381 and then Is_Constrained (Designated_Type (Etype (Expression (N))))
11383 Remove_Side_Effects (N);
11385 end Resolve_Type_Conversion;
11387 ----------------------
11388 -- Resolve_Unary_Op --
11389 ----------------------
11391 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
11392 B_Typ : constant Entity_Id := Base_Type (Typ);
11393 R : constant Node_Id := Right_Opnd (N);
11399 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
11400 Error_Msg_Name_1 := Chars (Typ);
11401 Check_SPARK_05_Restriction
11402 ("unary operator not defined for modular type%", N);
11405 -- Deal with intrinsic unary operators
11407 if Comes_From_Source (N)
11408 and then Ekind (Entity (N)) = E_Function
11409 and then Is_Imported (Entity (N))
11410 and then Is_Intrinsic_Subprogram (Entity (N))
11412 Resolve_Intrinsic_Unary_Operator (N, Typ);
11416 -- Deal with universal cases
11418 if Etype (R) = Universal_Integer
11420 Etype (R) = Universal_Real
11422 Check_For_Visible_Operator (N, B_Typ);
11425 Set_Etype (N, B_Typ);
11426 Resolve (R, B_Typ);
11428 -- Generate warning for expressions like abs (x mod 2)
11430 if Warn_On_Redundant_Constructs
11431 and then Nkind (N) = N_Op_Abs
11433 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
11435 if OK and then Hi >= Lo and then Lo >= 0 then
11436 Error_Msg_N -- CODEFIX
11437 ("?r?abs applied to known non-negative value has no effect", N);
11441 -- Deal with reference generation
11443 Check_Unset_Reference (R);
11444 Generate_Operator_Reference (N, B_Typ);
11445 Analyze_Dimension (N);
11448 -- Set overflow checking bit. Much cleverer code needed here eventually
11449 -- and perhaps the Resolve routines should be separated for the various
11450 -- arithmetic operations, since they will need different processing ???
11452 if Nkind (N) in N_Op then
11453 if not Overflow_Checks_Suppressed (Etype (N)) then
11454 Enable_Overflow_Check (N);
11458 -- Generate warning for expressions like -5 mod 3 for integers. No need
11459 -- to worry in the floating-point case, since parens do not affect the
11460 -- result so there is no point in giving in a warning.
11463 Norig : constant Node_Id := Original_Node (N);
11472 if Warn_On_Questionable_Missing_Parens
11473 and then Comes_From_Source (Norig)
11474 and then Is_Integer_Type (Typ)
11475 and then Nkind (Norig) = N_Op_Minus
11477 Rorig := Original_Node (Right_Opnd (Norig));
11479 -- We are looking for cases where the right operand is not
11480 -- parenthesized, and is a binary operator, multiply, divide, or
11481 -- mod. These are the cases where the grouping can affect results.
11483 if Paren_Count (Rorig) = 0
11484 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11486 -- For mod, we always give the warning, since the value is
11487 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11488 -- -(5 mod 315)). But for the other cases, the only concern is
11489 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11490 -- overflows, but (-2) * 64 does not). So we try to give the
11491 -- message only when overflow is possible.
11493 if Nkind (Rorig) /= N_Op_Mod
11494 and then Compile_Time_Known_Value (R)
11496 Val := Expr_Value (R);
11498 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11499 HB := Expr_Value (Type_High_Bound (Typ));
11501 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11504 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11505 LB := Expr_Value (Type_Low_Bound (Typ));
11507 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11510 -- Note that the test below is deliberately excluding the
11511 -- largest negative number, since that is a potentially
11512 -- troublesome case (e.g. -2 * x, where the result is the
11513 -- largest negative integer has an overflow with 2 * x).
11515 if Val > LB and then Val <= HB then
11520 -- For the multiplication case, the only case we have to worry
11521 -- about is when (-a)*b is exactly the largest negative number
11522 -- so that -(a*b) can cause overflow. This can only happen if
11523 -- a is a power of 2, and more generally if any operand is a
11524 -- constant that is not a power of 2, then the parentheses
11525 -- cannot affect whether overflow occurs. We only bother to
11526 -- test the left most operand
11528 -- Loop looking at left operands for one that has known value
11531 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11532 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11533 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11535 -- Operand value of 0 or 1 skips warning
11540 -- Otherwise check power of 2, if power of 2, warn, if
11541 -- anything else, skip warning.
11544 while Lval /= 2 loop
11545 if Lval mod 2 = 1 then
11556 -- Keep looking at left operands
11558 Opnd := Left_Opnd (Opnd);
11559 end loop Opnd_Loop;
11561 -- For rem or "/" we can only have a problematic situation
11562 -- if the divisor has a value of minus one or one. Otherwise
11563 -- overflow is impossible (divisor > 1) or we have a case of
11564 -- division by zero in any case.
11566 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11567 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11568 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11573 -- If we fall through warning should be issued
11575 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11578 ("??unary minus expression should be parenthesized here!", N);
11582 end Resolve_Unary_Op;
11584 ----------------------------------
11585 -- Resolve_Unchecked_Expression --
11586 ----------------------------------
11588 procedure Resolve_Unchecked_Expression
11593 Resolve (Expression (N), Typ, Suppress => All_Checks);
11594 Set_Etype (N, Typ);
11595 end Resolve_Unchecked_Expression;
11597 ---------------------------------------
11598 -- Resolve_Unchecked_Type_Conversion --
11599 ---------------------------------------
11601 procedure Resolve_Unchecked_Type_Conversion
11605 pragma Warnings (Off, Typ);
11607 Operand : constant Node_Id := Expression (N);
11608 Opnd_Type : constant Entity_Id := Etype (Operand);
11611 -- Resolve operand using its own type
11613 Resolve (Operand, Opnd_Type);
11615 -- In an inlined context, the unchecked conversion may be applied
11616 -- to a literal, in which case its type is the type of the context.
11617 -- (In other contexts conversions cannot apply to literals).
11620 and then (Opnd_Type = Any_Character or else
11621 Opnd_Type = Any_Integer or else
11622 Opnd_Type = Any_Real)
11624 Set_Etype (Operand, Typ);
11627 Analyze_Dimension (N);
11628 Eval_Unchecked_Conversion (N);
11629 end Resolve_Unchecked_Type_Conversion;
11631 ------------------------------
11632 -- Rewrite_Operator_As_Call --
11633 ------------------------------
11635 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11636 Loc : constant Source_Ptr := Sloc (N);
11637 Actuals : constant List_Id := New_List;
11641 if Nkind (N) in N_Binary_Op then
11642 Append (Left_Opnd (N), Actuals);
11645 Append (Right_Opnd (N), Actuals);
11648 Make_Function_Call (Sloc => Loc,
11649 Name => New_Occurrence_Of (Nam, Loc),
11650 Parameter_Associations => Actuals);
11652 Preserve_Comes_From_Source (New_N, N);
11653 Preserve_Comes_From_Source (Name (New_N), N);
11654 Rewrite (N, New_N);
11655 Set_Etype (N, Etype (Nam));
11656 end Rewrite_Operator_As_Call;
11658 ------------------------------
11659 -- Rewrite_Renamed_Operator --
11660 ------------------------------
11662 procedure Rewrite_Renamed_Operator
11667 Nam : constant Name_Id := Chars (Op);
11668 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11672 -- Do not perform this transformation within a pre/postcondition,
11673 -- because the expression will be reanalyzed, and the transformation
11674 -- might affect the visibility of the operator, e.g. in an instance.
11675 -- Note that fully analyzed and expanded pre/postconditions appear as
11676 -- pragma Check equivalents.
11678 if In_Pre_Post_Condition (N) then
11682 -- Likewise when an expression function is being preanalyzed, since the
11683 -- expression will be reanalyzed as part of the generated body.
11685 if In_Spec_Expression then
11687 S : constant Entity_Id := Current_Scope_No_Loops;
11689 if Ekind (S) = E_Function
11690 and then Nkind (Original_Node (Unit_Declaration_Node (S))) =
11691 N_Expression_Function
11698 -- Rewrite the operator node using the real operator, not its renaming.
11699 -- Exclude user-defined intrinsic operations of the same name, which are
11700 -- treated separately and rewritten as calls.
11702 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11703 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11704 Set_Chars (Op_Node, Nam);
11705 Set_Etype (Op_Node, Etype (N));
11706 Set_Entity (Op_Node, Op);
11707 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11709 -- Indicate that both the original entity and its renaming are
11710 -- referenced at this point.
11712 Generate_Reference (Entity (N), N);
11713 Generate_Reference (Op, N);
11716 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11719 Rewrite (N, Op_Node);
11721 -- If the context type is private, add the appropriate conversions so
11722 -- that the operator is applied to the full view. This is done in the
11723 -- routines that resolve intrinsic operators.
11725 if Is_Intrinsic_Subprogram (Op) and then Is_Private_Type (Typ) then
11735 Resolve_Intrinsic_Operator (N, Typ);
11741 Resolve_Intrinsic_Unary_Operator (N, Typ);
11748 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11750 -- Operator renames a user-defined operator of the same name. Use the
11751 -- original operator in the node, which is the one Gigi knows about.
11753 Set_Entity (N, Op);
11754 Set_Is_Overloaded (N, False);
11756 end Rewrite_Renamed_Operator;
11758 -----------------------
11759 -- Set_Slice_Subtype --
11760 -----------------------
11762 -- Build an implicit subtype declaration to represent the type delivered by
11763 -- the slice. This is an abbreviated version of an array subtype. We define
11764 -- an index subtype for the slice, using either the subtype name or the
11765 -- discrete range of the slice. To be consistent with index usage elsewhere
11766 -- we create a list header to hold the single index. This list is not
11767 -- otherwise attached to the syntax tree.
11769 procedure Set_Slice_Subtype (N : Node_Id) is
11770 Loc : constant Source_Ptr := Sloc (N);
11771 Index_List : constant List_Id := New_List;
11773 Index_Subtype : Entity_Id;
11774 Index_Type : Entity_Id;
11775 Slice_Subtype : Entity_Id;
11776 Drange : constant Node_Id := Discrete_Range (N);
11779 Index_Type := Base_Type (Etype (Drange));
11781 if Is_Entity_Name (Drange) then
11782 Index_Subtype := Entity (Drange);
11785 -- We force the evaluation of a range. This is definitely needed in
11786 -- the renamed case, and seems safer to do unconditionally. Note in
11787 -- any case that since we will create and insert an Itype referring
11788 -- to this range, we must make sure any side effect removal actions
11789 -- are inserted before the Itype definition.
11791 if Nkind (Drange) = N_Range then
11792 Force_Evaluation (Low_Bound (Drange));
11793 Force_Evaluation (High_Bound (Drange));
11795 -- If the discrete range is given by a subtype indication, the
11796 -- type of the slice is the base of the subtype mark.
11798 elsif Nkind (Drange) = N_Subtype_Indication then
11800 R : constant Node_Id := Range_Expression (Constraint (Drange));
11802 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11803 Force_Evaluation (Low_Bound (R));
11804 Force_Evaluation (High_Bound (R));
11808 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11810 -- Take a new copy of Drange (where bounds have been rewritten to
11811 -- reference side-effect-free names). Using a separate tree ensures
11812 -- that further expansion (e.g. while rewriting a slice assignment
11813 -- into a FOR loop) does not attempt to remove side effects on the
11814 -- bounds again (which would cause the bounds in the index subtype
11815 -- definition to refer to temporaries before they are defined) (the
11816 -- reason is that some names are considered side effect free here
11817 -- for the subtype, but not in the context of a loop iteration
11820 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11821 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11822 Set_Etype (Index_Subtype, Index_Type);
11823 Set_Size_Info (Index_Subtype, Index_Type);
11824 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11827 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11829 Index := New_Occurrence_Of (Index_Subtype, Loc);
11830 Set_Etype (Index, Index_Subtype);
11831 Append (Index, Index_List);
11833 Set_First_Index (Slice_Subtype, Index);
11834 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11835 Set_Is_Constrained (Slice_Subtype, True);
11837 Check_Compile_Time_Size (Slice_Subtype);
11839 -- The Etype of the existing Slice node is reset to this slice subtype.
11840 -- Its bounds are obtained from its first index.
11842 Set_Etype (N, Slice_Subtype);
11844 -- For bit-packed slice subtypes, freeze immediately (except in the case
11845 -- of being in a "spec expression" where we never freeze when we first
11846 -- see the expression).
11848 if Is_Bit_Packed_Array (Slice_Subtype) and not In_Spec_Expression then
11849 Freeze_Itype (Slice_Subtype, N);
11851 -- For all other cases insert an itype reference in the slice's actions
11852 -- so that the itype is frozen at the proper place in the tree (i.e. at
11853 -- the point where actions for the slice are analyzed). Note that this
11854 -- is different from freezing the itype immediately, which might be
11855 -- premature (e.g. if the slice is within a transient scope). This needs
11856 -- to be done only if expansion is enabled.
11858 elsif Expander_Active then
11859 Ensure_Defined (Typ => Slice_Subtype, N => N);
11861 end Set_Slice_Subtype;
11863 --------------------------------
11864 -- Set_String_Literal_Subtype --
11865 --------------------------------
11867 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11868 Loc : constant Source_Ptr := Sloc (N);
11869 Low_Bound : constant Node_Id :=
11870 Type_Low_Bound (Etype (First_Index (Typ)));
11871 Subtype_Id : Entity_Id;
11874 if Nkind (N) /= N_String_Literal then
11878 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11879 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11880 (String_Length (Strval (N))));
11881 Set_Etype (Subtype_Id, Base_Type (Typ));
11882 Set_Is_Constrained (Subtype_Id);
11883 Set_Etype (N, Subtype_Id);
11885 -- The low bound is set from the low bound of the corresponding index
11886 -- type. Note that we do not store the high bound in the string literal
11887 -- subtype, but it can be deduced if necessary from the length and the
11890 if Is_OK_Static_Expression (Low_Bound) then
11891 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11893 -- If the lower bound is not static we create a range for the string
11894 -- literal, using the index type and the known length of the literal.
11895 -- The index type is not necessarily Positive, so the upper bound is
11896 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11900 Index_List : constant List_Id := New_List;
11901 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11902 High_Bound : constant Node_Id :=
11903 Make_Attribute_Reference (Loc,
11904 Attribute_Name => Name_Val,
11906 New_Occurrence_Of (Index_Type, Loc),
11907 Expressions => New_List (
11910 Make_Attribute_Reference (Loc,
11911 Attribute_Name => Name_Pos,
11913 New_Occurrence_Of (Index_Type, Loc),
11915 New_List (New_Copy_Tree (Low_Bound))),
11917 Make_Integer_Literal (Loc,
11918 String_Length (Strval (N)) - 1))));
11920 Array_Subtype : Entity_Id;
11923 Index_Subtype : Entity_Id;
11926 if Is_Integer_Type (Index_Type) then
11927 Set_String_Literal_Low_Bound
11928 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11931 -- If the index type is an enumeration type, build bounds
11932 -- expression with attributes.
11934 Set_String_Literal_Low_Bound
11936 Make_Attribute_Reference (Loc,
11937 Attribute_Name => Name_First,
11939 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11940 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11943 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11945 -- Build bona fide subtype for the string, and wrap it in an
11946 -- unchecked conversion, because the back end expects the
11947 -- String_Literal_Subtype to have a static lower bound.
11950 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11951 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11952 Set_Scalar_Range (Index_Subtype, Drange);
11953 Set_Parent (Drange, N);
11954 Analyze_And_Resolve (Drange, Index_Type);
11956 -- In this context, the Index_Type may already have a constraint,
11957 -- so use common base type on string subtype. The base type may
11958 -- be used when generating attributes of the string, for example
11959 -- in the context of a slice assignment.
11961 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11962 Set_Size_Info (Index_Subtype, Index_Type);
11963 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11965 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11967 Index := New_Occurrence_Of (Index_Subtype, Loc);
11968 Set_Etype (Index, Index_Subtype);
11969 Append (Index, Index_List);
11971 Set_First_Index (Array_Subtype, Index);
11972 Set_Etype (Array_Subtype, Base_Type (Typ));
11973 Set_Is_Constrained (Array_Subtype, True);
11976 Make_Unchecked_Type_Conversion (Loc,
11977 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11978 Expression => Relocate_Node (N)));
11979 Set_Etype (N, Array_Subtype);
11982 end Set_String_Literal_Subtype;
11984 ------------------------------
11985 -- Simplify_Type_Conversion --
11986 ------------------------------
11988 procedure Simplify_Type_Conversion (N : Node_Id) is
11990 if Nkind (N) = N_Type_Conversion then
11992 Operand : constant Node_Id := Expression (N);
11993 Target_Typ : constant Entity_Id := Etype (N);
11994 Opnd_Typ : constant Entity_Id := Etype (Operand);
11997 -- Special processing if the conversion is the expression of a
11998 -- Rounding or Truncation attribute reference. In this case we
12001 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
12007 -- with the Float_Truncate flag set to False or True respectively,
12008 -- which is more efficient.
12010 if Is_Floating_Point_Type (Opnd_Typ)
12012 (Is_Integer_Type (Target_Typ)
12013 or else (Is_Fixed_Point_Type (Target_Typ)
12014 and then Conversion_OK (N)))
12015 and then Nkind (Operand) = N_Attribute_Reference
12016 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
12020 Truncate : constant Boolean :=
12021 Attribute_Name (Operand) = Name_Truncation;
12024 Relocate_Node (First (Expressions (Operand))));
12025 Set_Float_Truncate (N, Truncate);
12030 end Simplify_Type_Conversion;
12032 -----------------------------
12033 -- Unique_Fixed_Point_Type --
12034 -----------------------------
12036 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
12037 procedure Fixed_Point_Error (T1 : Entity_Id; T2 : Entity_Id);
12038 -- Give error messages for true ambiguity. Messages are posted on node
12039 -- N, and entities T1, T2 are the possible interpretations.
12041 -----------------------
12042 -- Fixed_Point_Error --
12043 -----------------------
12045 procedure Fixed_Point_Error (T1 : Entity_Id; T2 : Entity_Id) is
12047 Error_Msg_N ("ambiguous universal_fixed_expression", N);
12048 Error_Msg_NE ("\\possible interpretation as}", N, T1);
12049 Error_Msg_NE ("\\possible interpretation as}", N, T2);
12050 end Fixed_Point_Error;
12060 -- Start of processing for Unique_Fixed_Point_Type
12063 -- The operations on Duration are visible, so Duration is always a
12064 -- possible interpretation.
12066 T1 := Standard_Duration;
12068 -- Look for fixed-point types in enclosing scopes
12070 Scop := Current_Scope;
12071 while Scop /= Standard_Standard loop
12072 T2 := First_Entity (Scop);
12073 while Present (T2) loop
12074 if Is_Fixed_Point_Type (T2)
12075 and then Current_Entity (T2) = T2
12076 and then Scope (Base_Type (T2)) = Scop
12078 if Present (T1) then
12079 Fixed_Point_Error (T1, T2);
12089 Scop := Scope (Scop);
12092 -- Look for visible fixed type declarations in the context
12094 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
12095 while Present (Item) loop
12096 if Nkind (Item) = N_With_Clause then
12097 Scop := Entity (Name (Item));
12098 T2 := First_Entity (Scop);
12099 while Present (T2) loop
12100 if Is_Fixed_Point_Type (T2)
12101 and then Scope (Base_Type (T2)) = Scop
12102 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
12104 if Present (T1) then
12105 Fixed_Point_Error (T1, T2);
12119 if Nkind (N) = N_Real_Literal then
12120 Error_Msg_NE ("??real literal interpreted as }!", N, T1);
12123 -- When the context is a type conversion, issue the warning on the
12124 -- expression of the conversion because it is the actual operation.
12126 if Nkind_In (N, N_Type_Conversion, N_Unchecked_Type_Conversion) then
12127 ErrN := Expression (N);
12133 ("??universal_fixed expression interpreted as }!", ErrN, T1);
12137 end Unique_Fixed_Point_Type;
12139 ----------------------
12140 -- Valid_Conversion --
12141 ----------------------
12143 function Valid_Conversion
12145 Target : Entity_Id;
12147 Report_Errs : Boolean := True) return Boolean
12149 Target_Type : constant Entity_Id := Base_Type (Target);
12150 Opnd_Type : Entity_Id := Etype (Operand);
12151 Inc_Ancestor : Entity_Id;
12153 function Conversion_Check
12155 Msg : String) return Boolean;
12156 -- Little routine to post Msg if Valid is False, returns Valid value
12158 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
12159 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
12161 procedure Conversion_Error_NE
12163 N : Node_Or_Entity_Id;
12164 E : Node_Or_Entity_Id);
12165 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
12167 function In_Instance_Code return Boolean;
12168 -- Return True if expression is within an instance but is not in one of
12169 -- the actuals of the instantiation. Type conversions within an instance
12170 -- are not rechecked because type visbility may lead to spurious errors,
12171 -- but conversions in an actual for a formal object must be checked.
12173 function Valid_Tagged_Conversion
12174 (Target_Type : Entity_Id;
12175 Opnd_Type : Entity_Id) return Boolean;
12176 -- Specifically test for validity of tagged conversions
12178 function Valid_Array_Conversion return Boolean;
12179 -- Check index and component conformance, and accessibility levels if
12180 -- the component types are anonymous access types (Ada 2005).
12182 ----------------------
12183 -- Conversion_Check --
12184 ----------------------
12186 function Conversion_Check
12188 Msg : String) return Boolean
12193 -- A generic unit has already been analyzed and we have verified
12194 -- that a particular conversion is OK in that context. Since the
12195 -- instance is reanalyzed without relying on the relationships
12196 -- established during the analysis of the generic, it is possible
12197 -- to end up with inconsistent views of private types. Do not emit
12198 -- the error message in such cases. The rest of the machinery in
12199 -- Valid_Conversion still ensures the proper compatibility of
12200 -- target and operand types.
12202 and then not In_Instance_Code
12204 Conversion_Error_N (Msg, Operand);
12208 end Conversion_Check;
12210 ------------------------
12211 -- Conversion_Error_N --
12212 ------------------------
12214 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
12216 if Report_Errs then
12217 Error_Msg_N (Msg, N);
12219 end Conversion_Error_N;
12221 -------------------------
12222 -- Conversion_Error_NE --
12223 -------------------------
12225 procedure Conversion_Error_NE
12227 N : Node_Or_Entity_Id;
12228 E : Node_Or_Entity_Id)
12231 if Report_Errs then
12232 Error_Msg_NE (Msg, N, E);
12234 end Conversion_Error_NE;
12236 ----------------------
12237 -- In_Instance_Code --
12238 ----------------------
12240 function In_Instance_Code return Boolean is
12244 if not In_Instance then
12249 while Present (Par) loop
12251 -- The expression is part of an actual object if it appears in
12252 -- the generated object declaration in the instance.
12254 if Nkind (Par) = N_Object_Declaration
12255 and then Present (Corresponding_Generic_Association (Par))
12261 Nkind (Par) in N_Statement_Other_Than_Procedure_Call
12262 or else Nkind (Par) in N_Subprogram_Call
12263 or else Nkind (Par) in N_Declaration;
12266 Par := Parent (Par);
12269 -- Otherwise the expression appears within the instantiated unit
12273 end In_Instance_Code;
12275 ----------------------------
12276 -- Valid_Array_Conversion --
12277 ----------------------------
12279 function Valid_Array_Conversion return Boolean is
12280 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
12281 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
12283 Opnd_Index : Node_Id;
12284 Opnd_Index_Type : Entity_Id;
12286 Target_Comp_Type : constant Entity_Id :=
12287 Component_Type (Target_Type);
12288 Target_Comp_Base : constant Entity_Id :=
12289 Base_Type (Target_Comp_Type);
12291 Target_Index : Node_Id;
12292 Target_Index_Type : Entity_Id;
12295 -- Error if wrong number of dimensions
12298 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
12301 ("incompatible number of dimensions for conversion", Operand);
12304 -- Number of dimensions matches
12307 -- Loop through indexes of the two arrays
12309 Target_Index := First_Index (Target_Type);
12310 Opnd_Index := First_Index (Opnd_Type);
12311 while Present (Target_Index) and then Present (Opnd_Index) loop
12312 Target_Index_Type := Etype (Target_Index);
12313 Opnd_Index_Type := Etype (Opnd_Index);
12315 -- Error if index types are incompatible
12317 if not (Is_Integer_Type (Target_Index_Type)
12318 and then Is_Integer_Type (Opnd_Index_Type))
12319 and then (Root_Type (Target_Index_Type)
12320 /= Root_Type (Opnd_Index_Type))
12323 ("incompatible index types for array conversion",
12328 Next_Index (Target_Index);
12329 Next_Index (Opnd_Index);
12332 -- If component types have same base type, all set
12334 if Target_Comp_Base = Opnd_Comp_Base then
12337 -- Here if base types of components are not the same. The only
12338 -- time this is allowed is if we have anonymous access types.
12340 -- The conversion of arrays of anonymous access types can lead
12341 -- to dangling pointers. AI-392 formalizes the accessibility
12342 -- checks that must be applied to such conversions to prevent
12343 -- out-of-scope references.
12346 (Target_Comp_Base, E_Anonymous_Access_Type,
12347 E_Anonymous_Access_Subprogram_Type)
12348 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
12350 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
12352 if Type_Access_Level (Target_Type) <
12353 Deepest_Type_Access_Level (Opnd_Type)
12355 if In_Instance_Body then
12356 Error_Msg_Warn := SPARK_Mode /= On;
12358 ("source array type has deeper accessibility "
12359 & "level than target<<", Operand);
12360 Conversion_Error_N ("\Program_Error [<<", Operand);
12362 Make_Raise_Program_Error (Sloc (N),
12363 Reason => PE_Accessibility_Check_Failed));
12364 Set_Etype (N, Target_Type);
12367 -- Conversion not allowed because of accessibility levels
12371 ("source array type has deeper accessibility "
12372 & "level than target", Operand);
12380 -- All other cases where component base types do not match
12384 ("incompatible component types for array conversion",
12389 -- Check that component subtypes statically match. For numeric
12390 -- types this means that both must be either constrained or
12391 -- unconstrained. For enumeration types the bounds must match.
12392 -- All of this is checked in Subtypes_Statically_Match.
12394 if not Subtypes_Statically_Match
12395 (Target_Comp_Type, Opnd_Comp_Type)
12398 ("component subtypes must statically match", Operand);
12404 end Valid_Array_Conversion;
12406 -----------------------------
12407 -- Valid_Tagged_Conversion --
12408 -----------------------------
12410 function Valid_Tagged_Conversion
12411 (Target_Type : Entity_Id;
12412 Opnd_Type : Entity_Id) return Boolean
12415 -- Upward conversions are allowed (RM 4.6(22))
12417 if Covers (Target_Type, Opnd_Type)
12418 or else Is_Ancestor (Target_Type, Opnd_Type)
12422 -- Downward conversion are allowed if the operand is class-wide
12425 elsif Is_Class_Wide_Type (Opnd_Type)
12426 and then Covers (Opnd_Type, Target_Type)
12430 elsif Covers (Opnd_Type, Target_Type)
12431 or else Is_Ancestor (Opnd_Type, Target_Type)
12434 Conversion_Check (False,
12435 "downward conversion of tagged objects not allowed");
12437 -- Ada 2005 (AI-251): The conversion to/from interface types is
12438 -- always valid. The types involved may be class-wide (sub)types.
12440 elsif Is_Interface (Etype (Base_Type (Target_Type)))
12441 or else Is_Interface (Etype (Base_Type (Opnd_Type)))
12445 -- If the operand is a class-wide type obtained through a limited_
12446 -- with clause, and the context includes the nonlimited view, use
12447 -- it to determine whether the conversion is legal.
12449 elsif Is_Class_Wide_Type (Opnd_Type)
12450 and then From_Limited_With (Opnd_Type)
12451 and then Present (Non_Limited_View (Etype (Opnd_Type)))
12452 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
12456 elsif Is_Access_Type (Opnd_Type)
12457 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
12462 Conversion_Error_NE
12463 ("invalid tagged conversion, not compatible with}",
12464 N, First_Subtype (Opnd_Type));
12467 end Valid_Tagged_Conversion;
12469 -- Start of processing for Valid_Conversion
12472 Check_Parameterless_Call (Operand);
12474 if Is_Overloaded (Operand) then
12484 -- Remove procedure calls, which syntactically cannot appear in
12485 -- this context, but which cannot be removed by type checking,
12486 -- because the context does not impose a type.
12488 -- The node may be labelled overloaded, but still contain only one
12489 -- interpretation because others were discarded earlier. If this
12490 -- is the case, retain the single interpretation if legal.
12492 Get_First_Interp (Operand, I, It);
12493 Opnd_Type := It.Typ;
12494 Get_Next_Interp (I, It);
12496 if Present (It.Typ)
12497 and then Opnd_Type /= Standard_Void_Type
12499 -- More than one candidate interpretation is available
12501 Get_First_Interp (Operand, I, It);
12502 while Present (It.Typ) loop
12503 if It.Typ = Standard_Void_Type then
12507 -- When compiling for a system where Address is of a visible
12508 -- integer type, spurious ambiguities can be produced when
12509 -- arithmetic operations have a literal operand and return
12510 -- System.Address or a descendant of it. These ambiguities
12511 -- are usually resolved by the context, but for conversions
12512 -- there is no context type and the removal of the spurious
12513 -- operations must be done explicitly here.
12515 if not Address_Is_Private
12516 and then Is_Descendant_Of_Address (It.Typ)
12521 Get_Next_Interp (I, It);
12525 Get_First_Interp (Operand, I, It);
12529 if No (It.Typ) then
12530 Conversion_Error_N ("illegal operand in conversion", Operand);
12534 Get_Next_Interp (I, It);
12536 if Present (It.Typ) then
12539 It1 := Disambiguate (Operand, I1, I, Any_Type);
12541 if It1 = No_Interp then
12543 ("ambiguous operand in conversion", Operand);
12545 -- If the interpretation involves a standard operator, use
12546 -- the location of the type, which may be user-defined.
12548 if Sloc (It.Nam) = Standard_Location then
12549 Error_Msg_Sloc := Sloc (It.Typ);
12551 Error_Msg_Sloc := Sloc (It.Nam);
12554 Conversion_Error_N -- CODEFIX
12555 ("\\possible interpretation#!", Operand);
12557 if Sloc (N1) = Standard_Location then
12558 Error_Msg_Sloc := Sloc (T1);
12560 Error_Msg_Sloc := Sloc (N1);
12563 Conversion_Error_N -- CODEFIX
12564 ("\\possible interpretation#!", Operand);
12570 Set_Etype (Operand, It1.Typ);
12571 Opnd_Type := It1.Typ;
12575 -- Deal with conversion of integer type to address if the pragma
12576 -- Allow_Integer_Address is in effect. We convert the conversion to
12577 -- an unchecked conversion in this case and we are all done.
12579 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12580 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12581 Analyze_And_Resolve (N, Target_Type);
12585 -- If we are within a child unit, check whether the type of the
12586 -- expression has an ancestor in a parent unit, in which case it
12587 -- belongs to its derivation class even if the ancestor is private.
12588 -- See RM 7.3.1 (5.2/3).
12590 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12594 if Is_Numeric_Type (Target_Type) then
12596 -- A universal fixed expression can be converted to any numeric type
12598 if Opnd_Type = Universal_Fixed then
12601 -- Also no need to check when in an instance or inlined body, because
12602 -- the legality has been established when the template was analyzed.
12603 -- Furthermore, numeric conversions may occur where only a private
12604 -- view of the operand type is visible at the instantiation point.
12605 -- This results in a spurious error if we check that the operand type
12606 -- is a numeric type.
12608 -- Note: in a previous version of this unit, the following tests were
12609 -- applied only for generated code (Comes_From_Source set to False),
12610 -- but in fact the test is required for source code as well, since
12611 -- this situation can arise in source code.
12613 elsif In_Instance_Code or else In_Inlined_Body then
12616 -- Otherwise we need the conversion check
12619 return Conversion_Check
12620 (Is_Numeric_Type (Opnd_Type)
12622 (Present (Inc_Ancestor)
12623 and then Is_Numeric_Type (Inc_Ancestor)),
12624 "illegal operand for numeric conversion");
12629 elsif Is_Array_Type (Target_Type) then
12630 if not Is_Array_Type (Opnd_Type)
12631 or else Opnd_Type = Any_Composite
12632 or else Opnd_Type = Any_String
12635 ("illegal operand for array conversion", Operand);
12639 return Valid_Array_Conversion;
12642 -- Ada 2005 (AI-251): Internally generated conversions of access to
12643 -- interface types added to force the displacement of the pointer to
12644 -- reference the corresponding dispatch table.
12646 elsif not Comes_From_Source (N)
12647 and then Is_Access_Type (Target_Type)
12648 and then Is_Interface (Designated_Type (Target_Type))
12652 -- Ada 2005 (AI-251): Anonymous access types where target references an
12655 elsif Is_Access_Type (Opnd_Type)
12656 and then Ekind_In (Target_Type, E_General_Access_Type,
12657 E_Anonymous_Access_Type)
12658 and then Is_Interface (Directly_Designated_Type (Target_Type))
12660 -- Check the static accessibility rule of 4.6(17). Note that the
12661 -- check is not enforced when within an instance body, since the
12662 -- RM requires such cases to be caught at run time.
12664 -- If the operand is a rewriting of an allocator no check is needed
12665 -- because there are no accessibility issues.
12667 if Nkind (Original_Node (N)) = N_Allocator then
12670 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12671 if Type_Access_Level (Opnd_Type) >
12672 Deepest_Type_Access_Level (Target_Type)
12674 -- In an instance, this is a run-time check, but one we know
12675 -- will fail, so generate an appropriate warning. The raise
12676 -- will be generated by Expand_N_Type_Conversion.
12678 if In_Instance_Body then
12679 Error_Msg_Warn := SPARK_Mode /= On;
12681 ("cannot convert local pointer to non-local access type<<",
12683 Conversion_Error_N ("\Program_Error [<<", Operand);
12687 ("cannot convert local pointer to non-local access type",
12692 -- Special accessibility checks are needed in the case of access
12693 -- discriminants declared for a limited type.
12695 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12696 and then not Is_Local_Anonymous_Access (Opnd_Type)
12698 -- When the operand is a selected access discriminant the check
12699 -- needs to be made against the level of the object denoted by
12700 -- the prefix of the selected name (Object_Access_Level handles
12701 -- checking the prefix of the operand for this case).
12703 if Nkind (Operand) = N_Selected_Component
12704 and then Object_Access_Level (Operand) >
12705 Deepest_Type_Access_Level (Target_Type)
12707 -- In an instance, this is a run-time check, but one we know
12708 -- will fail, so generate an appropriate warning. The raise
12709 -- will be generated by Expand_N_Type_Conversion.
12711 if In_Instance_Body then
12712 Error_Msg_Warn := SPARK_Mode /= On;
12714 ("cannot convert access discriminant to non-local "
12715 & "access type<<", Operand);
12716 Conversion_Error_N ("\Program_Error [<<", Operand);
12718 -- Real error if not in instance body
12722 ("cannot convert access discriminant to non-local "
12723 & "access type", Operand);
12728 -- The case of a reference to an access discriminant from
12729 -- within a limited type declaration (which will appear as
12730 -- a discriminal) is always illegal because the level of the
12731 -- discriminant is considered to be deeper than any (nameable)
12734 if Is_Entity_Name (Operand)
12735 and then not Is_Local_Anonymous_Access (Opnd_Type)
12737 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12738 and then Present (Discriminal_Link (Entity (Operand)))
12741 ("discriminant has deeper accessibility level than target",
12750 -- General and anonymous access types
12752 elsif Ekind_In (Target_Type, E_General_Access_Type,
12753 E_Anonymous_Access_Type)
12756 (Is_Access_Type (Opnd_Type)
12758 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12759 E_Access_Protected_Subprogram_Type),
12760 "must be an access-to-object type")
12762 if Is_Access_Constant (Opnd_Type)
12763 and then not Is_Access_Constant (Target_Type)
12766 ("access-to-constant operand type not allowed", Operand);
12770 -- Check the static accessibility rule of 4.6(17). Note that the
12771 -- check is not enforced when within an instance body, since the RM
12772 -- requires such cases to be caught at run time.
12774 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12775 or else Is_Local_Anonymous_Access (Target_Type)
12776 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12777 N_Object_Declaration
12779 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12780 -- conversions from an anonymous access type to a named general
12781 -- access type. Such conversions are not allowed in the case of
12782 -- access parameters and stand-alone objects of an anonymous
12783 -- access type. The implicit conversion case is recognized by
12784 -- testing that Comes_From_Source is False and that it's been
12785 -- rewritten. The Comes_From_Source test isn't sufficient because
12786 -- nodes in inlined calls to predefined library routines can have
12787 -- Comes_From_Source set to False. (Is there a better way to test
12788 -- for implicit conversions???)
12790 if Ada_Version >= Ada_2012
12791 and then not Comes_From_Source (N)
12792 and then Is_Rewrite_Substitution (N)
12793 and then Ekind (Target_Type) = E_General_Access_Type
12794 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12796 if Is_Itype (Opnd_Type) then
12798 -- Implicit conversions aren't allowed for objects of an
12799 -- anonymous access type, since such objects have nonstatic
12800 -- levels in Ada 2012.
12802 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12803 N_Object_Declaration
12806 ("implicit conversion of stand-alone anonymous "
12807 & "access object not allowed", Operand);
12810 -- Implicit conversions aren't allowed for anonymous access
12811 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12812 -- is done to exclude anonymous access results.
12814 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12815 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12816 N_Function_Specification,
12817 N_Procedure_Specification)
12820 ("implicit conversion of anonymous access formal "
12821 & "not allowed", Operand);
12824 -- This is a case where there's an enclosing object whose
12825 -- to which the "statically deeper than" relationship does
12826 -- not apply (such as an access discriminant selected from
12827 -- a dereference of an access parameter).
12829 elsif Object_Access_Level (Operand)
12830 = Scope_Depth (Standard_Standard)
12833 ("implicit conversion of anonymous access value "
12834 & "not allowed", Operand);
12837 -- In other cases, the level of the operand's type must be
12838 -- statically less deep than that of the target type, else
12839 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12841 elsif Type_Access_Level (Opnd_Type) >
12842 Deepest_Type_Access_Level (Target_Type)
12845 ("implicit conversion of anonymous access value "
12846 & "violates accessibility", Operand);
12851 elsif Type_Access_Level (Opnd_Type) >
12852 Deepest_Type_Access_Level (Target_Type)
12854 -- In an instance, this is a run-time check, but one we know
12855 -- will fail, so generate an appropriate warning. The raise
12856 -- will be generated by Expand_N_Type_Conversion.
12858 if In_Instance_Body then
12859 Error_Msg_Warn := SPARK_Mode /= On;
12861 ("cannot convert local pointer to non-local access type<<",
12863 Conversion_Error_N ("\Program_Error [<<", Operand);
12865 -- If not in an instance body, this is a real error
12868 -- Avoid generation of spurious error message
12870 if not Error_Posted (N) then
12872 ("cannot convert local pointer to non-local access type",
12879 -- Special accessibility checks are needed in the case of access
12880 -- discriminants declared for a limited type.
12882 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12883 and then not Is_Local_Anonymous_Access (Opnd_Type)
12885 -- When the operand is a selected access discriminant the check
12886 -- needs to be made against the level of the object denoted by
12887 -- the prefix of the selected name (Object_Access_Level handles
12888 -- checking the prefix of the operand for this case).
12890 if Nkind (Operand) = N_Selected_Component
12891 and then Object_Access_Level (Operand) >
12892 Deepest_Type_Access_Level (Target_Type)
12894 -- In an instance, this is a run-time check, but one we know
12895 -- will fail, so generate an appropriate warning. The raise
12896 -- will be generated by Expand_N_Type_Conversion.
12898 if In_Instance_Body then
12899 Error_Msg_Warn := SPARK_Mode /= On;
12901 ("cannot convert access discriminant to non-local "
12902 & "access type<<", Operand);
12903 Conversion_Error_N ("\Program_Error [<<", Operand);
12905 -- If not in an instance body, this is a real error
12909 ("cannot convert access discriminant to non-local "
12910 & "access type", Operand);
12915 -- The case of a reference to an access discriminant from
12916 -- within a limited type declaration (which will appear as
12917 -- a discriminal) is always illegal because the level of the
12918 -- discriminant is considered to be deeper than any (nameable)
12921 if Is_Entity_Name (Operand)
12923 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12924 and then Present (Discriminal_Link (Entity (Operand)))
12927 ("discriminant has deeper accessibility level than target",
12934 -- In the presence of limited_with clauses we have to use nonlimited
12935 -- views, if available.
12937 Check_Limited : declare
12938 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12939 -- Helper function to handle limited views
12941 --------------------------
12942 -- Full_Designated_Type --
12943 --------------------------
12945 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12946 Desig : constant Entity_Id := Designated_Type (T);
12949 -- Handle the limited view of a type
12951 if From_Limited_With (Desig)
12952 and then Has_Non_Limited_View (Desig)
12954 return Available_View (Desig);
12958 end Full_Designated_Type;
12960 -- Local Declarations
12962 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12963 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12965 Same_Base : constant Boolean :=
12966 Base_Type (Target) = Base_Type (Opnd);
12968 -- Start of processing for Check_Limited
12971 if Is_Tagged_Type (Target) then
12972 return Valid_Tagged_Conversion (Target, Opnd);
12975 if not Same_Base then
12976 Conversion_Error_NE
12977 ("target designated type not compatible with }",
12978 N, Base_Type (Opnd));
12981 -- Ada 2005 AI-384: legality rule is symmetric in both
12982 -- designated types. The conversion is legal (with possible
12983 -- constraint check) if either designated type is
12986 elsif Subtypes_Statically_Match (Target, Opnd)
12988 (Has_Discriminants (Target)
12990 (not Is_Constrained (Opnd)
12991 or else not Is_Constrained (Target)))
12993 -- Special case, if Value_Size has been used to make the
12994 -- sizes different, the conversion is not allowed even
12995 -- though the subtypes statically match.
12997 if Known_Static_RM_Size (Target)
12998 and then Known_Static_RM_Size (Opnd)
12999 and then RM_Size (Target) /= RM_Size (Opnd)
13001 Conversion_Error_NE
13002 ("target designated subtype not compatible with }",
13004 Conversion_Error_NE
13005 ("\because sizes of the two designated subtypes differ",
13009 -- Normal case where conversion is allowed
13017 ("target designated subtype not compatible with }",
13024 -- Access to subprogram types. If the operand is an access parameter,
13025 -- the type has a deeper accessibility that any master, and cannot be
13026 -- assigned. We must make an exception if the conversion is part of an
13027 -- assignment and the target is the return object of an extended return
13028 -- statement, because in that case the accessibility check takes place
13029 -- after the return.
13031 elsif Is_Access_Subprogram_Type (Target_Type)
13033 -- Note: this test of Opnd_Type is there to prevent entering this
13034 -- branch in the case of a remote access to subprogram type, which
13035 -- is internally represented as an E_Record_Type.
13037 and then Is_Access_Type (Opnd_Type)
13039 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
13040 and then Is_Entity_Name (Operand)
13041 and then Ekind (Entity (Operand)) = E_In_Parameter
13043 (Nkind (Parent (N)) /= N_Assignment_Statement
13044 or else not Is_Entity_Name (Name (Parent (N)))
13045 or else not Is_Return_Object (Entity (Name (Parent (N)))))
13048 ("illegal attempt to store anonymous access to subprogram",
13051 ("\value has deeper accessibility than any master "
13052 & "(RM 3.10.2 (13))",
13056 ("\use named access type for& instead of access parameter",
13057 Operand, Entity (Operand));
13060 -- Check that the designated types are subtype conformant
13062 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
13063 Old_Id => Designated_Type (Opnd_Type),
13066 -- Check the static accessibility rule of 4.6(20)
13068 if Type_Access_Level (Opnd_Type) >
13069 Deepest_Type_Access_Level (Target_Type)
13072 ("operand type has deeper accessibility level than target",
13075 -- Check that if the operand type is declared in a generic body,
13076 -- then the target type must be declared within that same body
13077 -- (enforces last sentence of 4.6(20)).
13079 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
13081 O_Gen : constant Node_Id :=
13082 Enclosing_Generic_Body (Opnd_Type);
13087 T_Gen := Enclosing_Generic_Body (Target_Type);
13088 while Present (T_Gen) and then T_Gen /= O_Gen loop
13089 T_Gen := Enclosing_Generic_Body (T_Gen);
13092 if T_Gen /= O_Gen then
13094 ("target type must be declared in same generic body "
13095 & "as operand type", N);
13102 -- Remote access to subprogram types
13104 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
13105 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
13107 -- It is valid to convert from one RAS type to another provided
13108 -- that their specification statically match.
13110 -- Note: at this point, remote access to subprogram types have been
13111 -- expanded to their E_Record_Type representation, and we need to
13112 -- go back to the original access type definition using the
13113 -- Corresponding_Remote_Type attribute in order to check that the
13114 -- designated profiles match.
13116 pragma Assert (Ekind (Target_Type) = E_Record_Type);
13117 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
13119 Check_Subtype_Conformant
13121 Designated_Type (Corresponding_Remote_Type (Target_Type)),
13123 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
13128 -- If it was legal in the generic, it's legal in the instance
13130 elsif In_Instance_Body then
13133 -- If both are tagged types, check legality of view conversions
13135 elsif Is_Tagged_Type (Target_Type)
13137 Is_Tagged_Type (Opnd_Type)
13139 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
13141 -- Types derived from the same root type are convertible
13143 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
13146 -- In an instance or an inlined body, there may be inconsistent views of
13147 -- the same type, or of types derived from a common root.
13149 elsif (In_Instance or In_Inlined_Body)
13151 Root_Type (Underlying_Type (Target_Type)) =
13152 Root_Type (Underlying_Type (Opnd_Type))
13156 -- Special check for common access type error case
13158 elsif Ekind (Target_Type) = E_Access_Type
13159 and then Is_Access_Type (Opnd_Type)
13161 Conversion_Error_N ("target type must be general access type!", N);
13162 Conversion_Error_NE -- CODEFIX
13163 ("add ALL to }!", N, Target_Type);
13166 -- Here we have a real conversion error
13169 -- Check for missing regular with_clause when only a limited view of
13170 -- target is available.
13172 if From_Limited_With (Opnd_Type) and then In_Package_Body then
13173 Conversion_Error_NE
13174 ("invalid conversion, not compatible with limited view of }",
13176 Conversion_Error_NE
13177 ("\add with_clause for& to current unit!", N, Scope (Opnd_Type));
13179 elsif Is_Access_Type (Opnd_Type)
13180 and then From_Limited_With (Designated_Type (Opnd_Type))
13181 and then In_Package_Body
13183 Conversion_Error_NE
13184 ("invalid conversion, not compatible with }", N, Opnd_Type);
13185 Conversion_Error_NE
13186 ("\add with_clause for& to current unit!",
13187 N, Scope (Designated_Type (Opnd_Type)));
13190 Conversion_Error_NE
13191 ("invalid conversion, not compatible with }", N, Opnd_Type);
13196 end Valid_Conversion;