1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Ghost; use Ghost;
41 with Inline; use Inline;
42 with Itypes; use Itypes;
44 with Lib.Xref; use Lib.Xref;
45 with Namet; use Namet;
46 with Nmake; use Nmake;
47 with Nlists; use Nlists;
49 with Output; use Output;
50 with Par_SCO; use Par_SCO;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Aggr; use Sem_Aggr;
57 with Sem_Attr; use Sem_Attr;
58 with Sem_Cat; use Sem_Cat;
59 with Sem_Ch4; use Sem_Ch4;
60 with Sem_Ch3; use Sem_Ch3;
61 with Sem_Ch6; use Sem_Ch6;
62 with Sem_Ch8; use Sem_Ch8;
63 with Sem_Ch13; use Sem_Ch13;
64 with Sem_Dim; use Sem_Dim;
65 with Sem_Disp; use Sem_Disp;
66 with Sem_Dist; use Sem_Dist;
67 with Sem_Elim; use Sem_Elim;
68 with Sem_Elab; use Sem_Elab;
69 with Sem_Eval; use Sem_Eval;
70 with Sem_Intr; use Sem_Intr;
71 with Sem_Util; use Sem_Util;
72 with Targparm; use Targparm;
73 with Sem_Type; use Sem_Type;
74 with Sem_Warn; use Sem_Warn;
75 with Sinfo; use Sinfo;
76 with Sinfo.CN; use Sinfo.CN;
77 with Snames; use Snames;
78 with Stand; use Stand;
79 with Stringt; use Stringt;
80 with Style; use Style;
81 with Tbuild; use Tbuild;
82 with Uintp; use Uintp;
83 with Urealp; use Urealp;
85 package body Sem_Res is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use (N : Node_Id);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
116 -- Given a call node, N, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
122 -- If the type of the object being initialized uses the secondary stack
123 -- directly or indirectly, create a transient scope for the call to the
124 -- init proc. This is because we do not create transient scopes for the
125 -- initialization of individual components within the init proc itself.
126 -- Could be optimized away perhaps?
128 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
129 -- N is the node for a logical operator. If the operator is predefined, and
130 -- the root type of the operands is Standard.Boolean, then a check is made
131 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
132 -- the style check for Style_Check_Boolean_And_Or.
134 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
135 -- N is either an indexed component or a selected component. This function
136 -- returns true if the prefix refers to an object that has an address
137 -- clause (the case in which we may want to issue a warning).
139 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
211 function Operator_Kind
213 Is_Binary : Boolean) return Node_Kind;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
236 -- Ditto, for arithmetic unary operators
238 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
242 procedure Make_Call_Into_Operator
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so that
248 -- operands are resolved properly. Recall that predefined operators do not
249 -- have a full signature and special resolution rules apply.
251 procedure Rewrite_Renamed_Operator
255 -- An operator can rename another, e.g. in an instantiation. In that
256 -- case, the proper operator node must be constructed and resolved.
258 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
259 -- The String_Literal_Subtype is built for all strings that are not
260 -- operands of a static concatenation operation. If the argument is not
261 -- a N_String_Literal node, then the call has no effect.
263 procedure Set_Slice_Subtype (N : Node_Id);
264 -- Build subtype of array type, with the range specified by the slice
266 procedure Simplify_Type_Conversion (N : Node_Id);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Rounding or Truncation attribute.
271 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
277 -------------------------
278 -- Ambiguous_Character --
279 -------------------------
281 procedure Ambiguous_Character (C : Node_Id) is
285 if Nkind (C) = N_Character_Literal then
286 Error_Msg_N ("ambiguous character literal", C);
288 -- First the ones in Standard
290 Error_Msg_N ("\\possible interpretation: Character!", C);
291 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
293 -- Include Wide_Wide_Character in Ada 2005 mode
295 if Ada_Version >= Ada_2005 then
296 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
299 -- Now any other types that match
301 E := Current_Entity (C);
302 while Present (E) loop
303 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
307 end Ambiguous_Character;
309 -------------------------
310 -- Analyze_And_Resolve --
311 -------------------------
313 procedure Analyze_And_Resolve (N : Node_Id) is
317 end Analyze_And_Resolve;
319 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
323 end Analyze_And_Resolve;
325 -- Versions with check(s) suppressed
327 procedure Analyze_And_Resolve
332 Scop : constant Entity_Id := Current_Scope;
335 if Suppress = All_Checks then
337 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
339 Scope_Suppress.Suppress := (others => True);
340 Analyze_And_Resolve (N, Typ);
341 Scope_Suppress.Suppress := Sva;
346 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
348 Scope_Suppress.Suppress (Suppress) := True;
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress.Suppress (Suppress) := Svg;
354 if Current_Scope /= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
366 end Analyze_And_Resolve;
368 procedure Analyze_And_Resolve
372 Scop : constant Entity_Id := Current_Scope;
375 if Suppress = All_Checks then
377 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
379 Scope_Suppress.Suppress := (others => True);
380 Analyze_And_Resolve (N);
381 Scope_Suppress.Suppress := Sva;
386 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
388 Scope_Suppress.Suppress (Suppress) := True;
389 Analyze_And_Resolve (N);
390 Scope_Suppress.Suppress (Suppress) := Svg;
394 if Current_Scope /= Scop and then Scope_Is_Transient then
395 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
398 end Analyze_And_Resolve;
400 ----------------------------
401 -- Check_Discriminant_Use --
402 ----------------------------
404 procedure Check_Discriminant_Use (N : Node_Id) is
405 PN : constant Node_Id := Parent (N);
406 Disc : constant Entity_Id := Entity (N);
411 -- Any use in a spec-expression is legal
413 if In_Spec_Expression then
416 elsif Nkind (PN) = N_Range then
418 -- Discriminant cannot be used to constrain a scalar type
422 if Nkind (P) = N_Range_Constraint
423 and then Nkind (Parent (P)) = N_Subtype_Indication
424 and then Nkind (Parent (Parent (P))) = N_Component_Definition
426 Error_Msg_N ("discriminant cannot constrain scalar type", N);
428 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
430 -- The following check catches the unusual case where a
431 -- discriminant appears within an index constraint that is part
432 -- of a larger expression within a constraint on a component,
433 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
434 -- check case of record components, and note that a similar check
435 -- should also apply in the case of discriminant constraints
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
446 if Ekind (Current_Scope) = E_Record_Type
447 and then Scope (Disc) = Current_Scope
449 (Nkind (Parent (P)) = N_Subtype_Indication
451 Nkind_In (Parent (Parent (P)), N_Component_Definition,
452 N_Subtype_Declaration)
453 and then Paren_Count (N) = 0)
456 ("discriminant must appear alone in component constraint", N);
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large : declare
477 function Large_Storage_Type (T : Entity_Id) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type (T : Entity_Id) return Boolean is
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value (Type_Low_Bound (T))
493 and then Compile_Time_Known_Value (Type_High_Bound (T))
495 Minimum_Size (T, Biased => True) >=
496 RM_Size (Standard_Positive);
497 end Large_Storage_Type;
499 -- Start of processing for Check_Large
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type (Etype (Disc)) then
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
512 if Is_Limited_Type (Scope (Disc)) then
516 -- Check that it is the high bound
518 if N /= High_Bound (PN)
519 or else No (Discriminant_Default_Value (Disc))
524 -- Check the array allows a large range at this bound. First
529 if Nkind (SI) /= N_Subtype_Indication then
533 T := Entity (Subtype_Mark (SI));
535 if not Is_Array_Type (T) then
539 -- Next, find the dimension
541 TB := First_Index (T);
542 CB := First (Constraints (P));
544 and then Present (TB)
545 and then Present (CB)
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type (Etype (TB)) then
562 -- Warn about the danger
565 ("??creation of & object may raise Storage_Error!",
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
577 N_Discriminant_Association)
579 if Paren_Count (N) > 0 then
581 ("discriminant in constraint must appear alone", N);
583 elsif Nkind (N) = N_Expanded_Name
584 and then Comes_From_Source (N)
587 ("discriminant must appear alone as a direct name", N);
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
598 while not Nkind_In (P, N_Component_Declaration,
599 N_Subtype_Indication,
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind (P) = N_Subtype_Indication
613 and then Nkind_In (Parent (P), N_Component_Definition,
614 N_Derived_Type_Definition)
615 and then D = Constraint (P))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind (P) = N_Subtype_Indication
622 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
623 or else Nkind (P) = N_Entry_Declaration
624 or else Nkind (D) = N_Defining_Identifier
627 ("discriminant in constraint must appear alone", N);
630 end Check_Discriminant_Use;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
638 if Is_Invisible_Operator (N, T) then
639 Error_Msg_NE -- CODEFIX
640 ("operator for} is not directly visible!", N, First_Subtype (T));
641 Error_Msg_N -- CODEFIX
642 ("use clause would make operation legal!", N);
644 end Check_For_Visible_Operator;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name (Pref)
674 and then Ekind (Entity (Pref)) = E_In_Parameter
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version >= Ada_2005
683 and then Is_Entity_Name (Pref)
684 and then Is_Access_Type (Etype (Pref))
685 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
687 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
691 Check_Fully_Declared (Typ, Parent (Pref));
693 end Check_Fully_Declared_Prefix;
695 ------------------------------
696 -- Check_Infinite_Recursion --
697 ------------------------------
699 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
703 function Same_Argument_List return Boolean;
704 -- Check whether list of actuals is identical to list of formals of
705 -- called function (which is also the enclosing scope).
707 ------------------------
708 -- Same_Argument_List --
709 ------------------------
711 function Same_Argument_List return Boolean is
717 if not Is_Entity_Name (Name (N)) then
720 Subp := Entity (Name (N));
723 F := First_Formal (Subp);
724 A := First_Actual (N);
725 while Present (F) and then Present (A) loop
726 if not Is_Entity_Name (A) or else Entity (A) /= F then
735 end Same_Argument_List;
737 -- Start of processing for Check_Infinite_Recursion
740 -- Special case, if this is a procedure call and is a call to the
741 -- current procedure with the same argument list, then this is for
742 -- sure an infinite recursion and we insert a call to raise SE.
744 if Is_List_Member (N)
745 and then List_Length (List_Containing (N)) = 1
746 and then Same_Argument_List
749 P : constant Node_Id := Parent (N);
751 if Nkind (P) = N_Handled_Sequence_Of_Statements
752 and then Nkind (Parent (P)) = N_Subprogram_Body
753 and then Is_Empty_List (Declarations (Parent (P)))
755 Error_Msg_Warn := SPARK_Mode /= On;
756 Error_Msg_N ("!infinite recursion<<", N);
757 Error_Msg_N ("\!Storage_Error [<<", N);
759 Make_Raise_Storage_Error (Sloc (N),
760 Reason => SE_Infinite_Recursion));
766 -- If not that special case, search up tree, quitting if we reach a
767 -- construct (e.g. a conditional) that tells us that this is not a
768 -- case for an infinite recursion warning.
774 -- If no parent, then we were not inside a subprogram, this can for
775 -- example happen when processing certain pragmas in a spec. Just
776 -- return False in this case.
782 -- Done if we get to subprogram body, this is definitely an infinite
783 -- recursion case if we did not find anything to stop us.
785 exit when Nkind (P) = N_Subprogram_Body;
787 -- If appearing in conditional, result is false
789 if Nkind_In (P, N_Or_Else,
798 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
799 and then C /= First (Statements (P))
801 -- If the call is the expression of a return statement and the
802 -- actuals are identical to the formals, it's worth a warning.
803 -- However, we skip this if there is an immediately preceding
804 -- raise statement, since the call is never executed.
806 -- Furthermore, this corresponds to a common idiom:
808 -- function F (L : Thing) return Boolean is
810 -- raise Program_Error;
814 -- for generating a stub function
816 if Nkind (Parent (N)) = N_Simple_Return_Statement
817 and then Same_Argument_List
819 exit when not Is_List_Member (Parent (N));
821 -- OK, return statement is in a statement list, look for raise
827 -- Skip past N_Freeze_Entity nodes generated by expansion
829 Nod := Prev (Parent (N));
831 and then Nkind (Nod) = N_Freeze_Entity
836 -- If no raise statement, give warning. We look at the
837 -- original node, because in the case of "raise ... with
838 -- ...", the node has been transformed into a call.
840 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
842 (Nkind (Nod) not in N_Raise_xxx_Error
843 or else Present (Condition (Nod)));
854 Error_Msg_Warn := SPARK_Mode /= On;
855 Error_Msg_N ("!possible infinite recursion<<", N);
856 Error_Msg_N ("\!??Storage_Error ]<<", N);
859 end Check_Infinite_Recursion;
861 -------------------------------
862 -- Check_Initialization_Call --
863 -------------------------------
865 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
866 Typ : constant Entity_Id := Etype (First_Formal (Nam));
868 function Uses_SS (T : Entity_Id) return Boolean;
869 -- Check whether the creation of an object of the type will involve
870 -- use of the secondary stack. If T is a record type, this is true
871 -- if the expression for some component uses the secondary stack, e.g.
872 -- through a call to a function that returns an unconstrained value.
873 -- False if T is controlled, because cleanups occur elsewhere.
879 function Uses_SS (T : Entity_Id) return Boolean is
882 Full_Type : Entity_Id := Underlying_Type (T);
885 -- Normally we want to use the underlying type, but if it's not set
886 -- then continue with T.
888 if not Present (Full_Type) then
892 if Is_Controlled (Full_Type) then
895 elsif Is_Array_Type (Full_Type) then
896 return Uses_SS (Component_Type (Full_Type));
898 elsif Is_Record_Type (Full_Type) then
899 Comp := First_Component (Full_Type);
900 while Present (Comp) loop
901 if Ekind (Comp) = E_Component
902 and then Nkind (Parent (Comp)) = N_Component_Declaration
904 -- The expression for a dynamic component may be rewritten
905 -- as a dereference, so retrieve original node.
907 Expr := Original_Node (Expression (Parent (Comp)));
909 -- Return True if the expression is a call to a function
910 -- (including an attribute function such as Image, or a
911 -- user-defined operator) with a result that requires a
914 if (Nkind (Expr) = N_Function_Call
915 or else Nkind (Expr) in N_Op
916 or else (Nkind (Expr) = N_Attribute_Reference
917 and then Present (Expressions (Expr))))
918 and then Requires_Transient_Scope (Etype (Expr))
922 elsif Uses_SS (Etype (Comp)) then
927 Next_Component (Comp);
937 -- Start of processing for Check_Initialization_Call
940 -- Establish a transient scope if the type needs it
942 if Uses_SS (Typ) then
943 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
945 end Check_Initialization_Call;
947 ---------------------------------------
948 -- Check_No_Direct_Boolean_Operators --
949 ---------------------------------------
951 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
953 if Scope (Entity (N)) = Standard_Standard
954 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
956 -- Restriction only applies to original source code
958 if Comes_From_Source (N) then
959 Check_Restriction (No_Direct_Boolean_Operators, N);
963 -- Do style check (but skip if in instance, error is on template)
966 if not In_Instance then
967 Check_Boolean_Operator (N);
970 end Check_No_Direct_Boolean_Operators;
972 ------------------------------
973 -- Check_Parameterless_Call --
974 ------------------------------
976 procedure Check_Parameterless_Call (N : Node_Id) is
979 function Prefix_Is_Access_Subp return Boolean;
980 -- If the prefix is of an access_to_subprogram type, the node must be
981 -- rewritten as a call. Ditto if the prefix is overloaded and all its
982 -- interpretations are access to subprograms.
984 ---------------------------
985 -- Prefix_Is_Access_Subp --
986 ---------------------------
988 function Prefix_Is_Access_Subp return Boolean is
993 -- If the context is an attribute reference that can apply to
994 -- functions, this is never a parameterless call (RM 4.1.4(6)).
996 if Nkind (Parent (N)) = N_Attribute_Reference
997 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1004 if not Is_Overloaded (N) then
1006 Ekind (Etype (N)) = E_Subprogram_Type
1007 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1009 Get_First_Interp (N, I, It);
1010 while Present (It.Typ) loop
1011 if Ekind (It.Typ) /= E_Subprogram_Type
1012 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1017 Get_Next_Interp (I, It);
1022 end Prefix_Is_Access_Subp;
1024 -- Start of processing for Check_Parameterless_Call
1027 -- Defend against junk stuff if errors already detected
1029 if Total_Errors_Detected /= 0 then
1030 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1032 elsif Nkind (N) in N_Has_Chars
1033 and then Chars (N) in Error_Name_Or_No_Name
1041 -- If the context expects a value, and the name is a procedure, this is
1042 -- most likely a missing 'Access. Don't try to resolve the parameterless
1043 -- call, error will be caught when the outer call is analyzed.
1045 if Is_Entity_Name (N)
1046 and then Ekind (Entity (N)) = E_Procedure
1047 and then not Is_Overloaded (N)
1049 Nkind_In (Parent (N), N_Parameter_Association,
1051 N_Procedure_Call_Statement)
1056 -- Rewrite as call if overloadable entity that is (or could be, in the
1057 -- overloaded case) a function call. If we know for sure that the entity
1058 -- is an enumeration literal, we do not rewrite it.
1060 -- If the entity is the name of an operator, it cannot be a call because
1061 -- operators cannot have default parameters. In this case, this must be
1062 -- a string whose contents coincide with an operator name. Set the kind
1063 -- of the node appropriately.
1065 if (Is_Entity_Name (N)
1066 and then Nkind (N) /= N_Operator_Symbol
1067 and then Is_Overloadable (Entity (N))
1068 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1069 or else Is_Overloaded (N)))
1071 -- Rewrite as call if it is an explicit dereference of an expression of
1072 -- a subprogram access type, and the subprogram type is not that of a
1073 -- procedure or entry.
1076 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1078 -- Rewrite as call if it is a selected component which is a function,
1079 -- this is the case of a call to a protected function (which may be
1080 -- overloaded with other protected operations).
1083 (Nkind (N) = N_Selected_Component
1084 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1086 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1088 and then Is_Overloaded (Selector_Name (N)))))
1090 -- If one of the above three conditions is met, rewrite as call. Apply
1091 -- the rewriting only once.
1094 if Nkind (Parent (N)) /= N_Function_Call
1095 or else N /= Name (Parent (N))
1098 -- This may be a prefixed call that was not fully analyzed, e.g.
1099 -- an actual in an instance.
1101 if Ada_Version >= Ada_2005
1102 and then Nkind (N) = N_Selected_Component
1103 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1105 Analyze_Selected_Component (N);
1107 if Nkind (N) /= N_Selected_Component then
1112 -- The node is the name of the parameterless call. Preserve its
1113 -- descendants, which may be complex expressions.
1115 Nam := Relocate_Node (N);
1117 -- If overloaded, overload set belongs to new copy
1119 Save_Interps (N, Nam);
1121 -- Change node to parameterless function call (note that the
1122 -- Parameter_Associations associations field is left set to Empty,
1123 -- its normal default value since there are no parameters)
1125 Change_Node (N, N_Function_Call);
1127 Set_Sloc (N, Sloc (Nam));
1131 elsif Nkind (N) = N_Parameter_Association then
1132 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1134 elsif Nkind (N) = N_Operator_Symbol then
1135 Change_Operator_Symbol_To_String_Literal (N);
1136 Set_Is_Overloaded (N, False);
1137 Set_Etype (N, Any_String);
1139 end Check_Parameterless_Call;
1141 --------------------------------
1142 -- Is_Atomic_Ref_With_Address --
1143 --------------------------------
1145 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1146 Pref : constant Node_Id := Prefix (N);
1149 if not Is_Entity_Name (Pref) then
1154 Pent : constant Entity_Id := Entity (Pref);
1155 Ptyp : constant Entity_Id := Etype (Pent);
1157 return not Is_Access_Type (Ptyp)
1158 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1159 and then Present (Address_Clause (Pent));
1162 end Is_Atomic_Ref_With_Address;
1164 -----------------------------
1165 -- Is_Definite_Access_Type --
1166 -----------------------------
1168 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1169 Btyp : constant Entity_Id := Base_Type (E);
1171 return Ekind (Btyp) = E_Access_Type
1172 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1173 and then Comes_From_Source (Btyp));
1174 end Is_Definite_Access_Type;
1176 ----------------------
1177 -- Is_Predefined_Op --
1178 ----------------------
1180 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1182 -- Predefined operators are intrinsic subprograms
1184 if not Is_Intrinsic_Subprogram (Nam) then
1188 -- A call to a back-end builtin is never a predefined operator
1190 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1194 return not Is_Generic_Instance (Nam)
1195 and then Chars (Nam) in Any_Operator_Name
1196 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1197 end Is_Predefined_Op;
1199 -----------------------------
1200 -- Make_Call_Into_Operator --
1201 -----------------------------
1203 procedure Make_Call_Into_Operator
1208 Op_Name : constant Name_Id := Chars (Op_Id);
1209 Act1 : Node_Id := First_Actual (N);
1210 Act2 : Node_Id := Next_Actual (Act1);
1211 Error : Boolean := False;
1212 Func : constant Entity_Id := Entity (Name (N));
1213 Is_Binary : constant Boolean := Present (Act2);
1215 Opnd_Type : Entity_Id;
1216 Orig_Type : Entity_Id := Empty;
1219 type Kind_Test is access function (E : Entity_Id) return Boolean;
1221 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1222 -- If the operand is not universal, and the operator is given by an
1223 -- expanded name, verify that the operand has an interpretation with a
1224 -- type defined in the given scope of the operator.
1226 function Type_In_P (Test : Kind_Test) return Entity_Id;
1227 -- Find a type of the given class in package Pack that contains the
1230 ---------------------------
1231 -- Operand_Type_In_Scope --
1232 ---------------------------
1234 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1235 Nod : constant Node_Id := Right_Opnd (Op_Node);
1240 if not Is_Overloaded (Nod) then
1241 return Scope (Base_Type (Etype (Nod))) = S;
1244 Get_First_Interp (Nod, I, It);
1245 while Present (It.Typ) loop
1246 if Scope (Base_Type (It.Typ)) = S then
1250 Get_Next_Interp (I, It);
1255 end Operand_Type_In_Scope;
1261 function Type_In_P (Test : Kind_Test) return Entity_Id is
1264 function In_Decl return Boolean;
1265 -- Verify that node is not part of the type declaration for the
1266 -- candidate type, which would otherwise be invisible.
1272 function In_Decl return Boolean is
1273 Decl_Node : constant Node_Id := Parent (E);
1279 if Etype (E) = Any_Type then
1282 elsif No (Decl_Node) then
1287 and then Nkind (N2) /= N_Compilation_Unit
1289 if N2 = Decl_Node then
1300 -- Start of processing for Type_In_P
1303 -- If the context type is declared in the prefix package, this is the
1304 -- desired base type.
1306 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1307 return Base_Type (Typ);
1310 E := First_Entity (Pack);
1311 while Present (E) loop
1312 if Test (E) and then not In_Decl then
1323 -- Start of processing for Make_Call_Into_Operator
1326 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1331 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1332 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1333 Save_Interps (Act1, Left_Opnd (Op_Node));
1334 Save_Interps (Act2, Right_Opnd (Op_Node));
1335 Act1 := Left_Opnd (Op_Node);
1336 Act2 := Right_Opnd (Op_Node);
1341 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1342 Save_Interps (Act1, Right_Opnd (Op_Node));
1343 Act1 := Right_Opnd (Op_Node);
1346 -- If the operator is denoted by an expanded name, and the prefix is
1347 -- not Standard, but the operator is a predefined one whose scope is
1348 -- Standard, then this is an implicit_operator, inserted as an
1349 -- interpretation by the procedure of the same name. This procedure
1350 -- overestimates the presence of implicit operators, because it does
1351 -- not examine the type of the operands. Verify now that the operand
1352 -- type appears in the given scope. If right operand is universal,
1353 -- check the other operand. In the case of concatenation, either
1354 -- argument can be the component type, so check the type of the result.
1355 -- If both arguments are literals, look for a type of the right kind
1356 -- defined in the given scope. This elaborate nonsense is brought to
1357 -- you courtesy of b33302a. The type itself must be frozen, so we must
1358 -- find the type of the proper class in the given scope.
1360 -- A final wrinkle is the multiplication operator for fixed point types,
1361 -- which is defined in Standard only, and not in the scope of the
1362 -- fixed point type itself.
1364 if Nkind (Name (N)) = N_Expanded_Name then
1365 Pack := Entity (Prefix (Name (N)));
1367 -- If this is a package renaming, get renamed entity, which will be
1368 -- the scope of the operands if operaton is type-correct.
1370 if Present (Renamed_Entity (Pack)) then
1371 Pack := Renamed_Entity (Pack);
1374 -- If the entity being called is defined in the given package, it is
1375 -- a renaming of a predefined operator, and known to be legal.
1377 if Scope (Entity (Name (N))) = Pack
1378 and then Pack /= Standard_Standard
1382 -- Visibility does not need to be checked in an instance: if the
1383 -- operator was not visible in the generic it has been diagnosed
1384 -- already, else there is an implicit copy of it in the instance.
1386 elsif In_Instance then
1389 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1390 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1391 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1393 if Pack /= Standard_Standard then
1397 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1400 elsif Ada_Version >= Ada_2005
1401 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1402 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1407 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1409 if Op_Name = Name_Op_Concat then
1410 Opnd_Type := Base_Type (Typ);
1412 elsif (Scope (Opnd_Type) = Standard_Standard
1414 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1416 and then not Comes_From_Source (Opnd_Type))
1418 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1421 if Scope (Opnd_Type) = Standard_Standard then
1423 -- Verify that the scope contains a type that corresponds to
1424 -- the given literal. Optimize the case where Pack is Standard.
1426 if Pack /= Standard_Standard then
1428 if Opnd_Type = Universal_Integer then
1429 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1431 elsif Opnd_Type = Universal_Real then
1432 Orig_Type := Type_In_P (Is_Real_Type'Access);
1434 elsif Opnd_Type = Any_String then
1435 Orig_Type := Type_In_P (Is_String_Type'Access);
1437 elsif Opnd_Type = Any_Access then
1438 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1440 elsif Opnd_Type = Any_Composite then
1441 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1443 if Present (Orig_Type) then
1444 if Has_Private_Component (Orig_Type) then
1447 Set_Etype (Act1, Orig_Type);
1450 Set_Etype (Act2, Orig_Type);
1459 Error := No (Orig_Type);
1462 elsif Ekind (Opnd_Type) = E_Allocator_Type
1463 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1467 -- If the type is defined elsewhere, and the operator is not
1468 -- defined in the given scope (by a renaming declaration, e.g.)
1469 -- then this is an error as well. If an extension of System is
1470 -- present, and the type may be defined there, Pack must be
1473 elsif Scope (Opnd_Type) /= Pack
1474 and then Scope (Op_Id) /= Pack
1475 and then (No (System_Aux_Id)
1476 or else Scope (Opnd_Type) /= System_Aux_Id
1477 or else Pack /= Scope (System_Aux_Id))
1479 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1482 Error := not Operand_Type_In_Scope (Pack);
1485 elsif Pack = Standard_Standard
1486 and then not Operand_Type_In_Scope (Standard_Standard)
1493 Error_Msg_Node_2 := Pack;
1495 ("& not declared in&", N, Selector_Name (Name (N)));
1496 Set_Etype (N, Any_Type);
1499 -- Detect a mismatch between the context type and the result type
1500 -- in the named package, which is otherwise not detected if the
1501 -- operands are universal. Check is only needed if source entity is
1502 -- an operator, not a function that renames an operator.
1504 elsif Nkind (Parent (N)) /= N_Type_Conversion
1505 and then Ekind (Entity (Name (N))) = E_Operator
1506 and then Is_Numeric_Type (Typ)
1507 and then not Is_Universal_Numeric_Type (Typ)
1508 and then Scope (Base_Type (Typ)) /= Pack
1509 and then not In_Instance
1511 if Is_Fixed_Point_Type (Typ)
1512 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1514 -- Already checked above
1518 -- Operator may be defined in an extension of System
1520 elsif Present (System_Aux_Id)
1521 and then Scope (Opnd_Type) = System_Aux_Id
1526 -- Could we use Wrong_Type here??? (this would require setting
1527 -- Etype (N) to the actual type found where Typ was expected).
1529 Error_Msg_NE ("expect }", N, Typ);
1534 Set_Chars (Op_Node, Op_Name);
1536 if not Is_Private_Type (Etype (N)) then
1537 Set_Etype (Op_Node, Base_Type (Etype (N)));
1539 Set_Etype (Op_Node, Etype (N));
1542 -- If this is a call to a function that renames a predefined equality,
1543 -- the renaming declaration provides a type that must be used to
1544 -- resolve the operands. This must be done now because resolution of
1545 -- the equality node will not resolve any remaining ambiguity, and it
1546 -- assumes that the first operand is not overloaded.
1548 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1549 and then Ekind (Func) = E_Function
1550 and then Is_Overloaded (Act1)
1552 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1553 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1556 Set_Entity (Op_Node, Op_Id);
1557 Generate_Reference (Op_Id, N, ' ');
1559 -- Do rewrite setting Comes_From_Source on the result if the original
1560 -- call came from source. Although it is not strictly the case that the
1561 -- operator as such comes from the source, logically it corresponds
1562 -- exactly to the function call in the source, so it should be marked
1563 -- this way (e.g. to make sure that validity checks work fine).
1566 CS : constant Boolean := Comes_From_Source (N);
1568 Rewrite (N, Op_Node);
1569 Set_Comes_From_Source (N, CS);
1572 -- If this is an arithmetic operator and the result type is private,
1573 -- the operands and the result must be wrapped in conversion to
1574 -- expose the underlying numeric type and expand the proper checks,
1575 -- e.g. on division.
1577 if Is_Private_Type (Typ) then
1579 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1580 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1581 Resolve_Intrinsic_Operator (N, Typ);
1583 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1584 Resolve_Intrinsic_Unary_Operator (N, Typ);
1593 -- If in ASIS_Mode, propagate operand types to original actuals of
1594 -- function call, which would otherwise not be fully resolved. If
1595 -- the call has already been constant-folded, nothing to do. We
1596 -- relocate the operand nodes rather than copy them, to preserve
1597 -- original_node pointers, given that the operands themselves may
1598 -- have been rewritten. If the call was itself a rewriting of an
1599 -- operator node, nothing to do.
1602 and then Nkind (N) in N_Op
1603 and then Nkind (Original_Node (N)) = N_Function_Call
1607 R : constant Node_Id := Right_Opnd (N);
1609 Old_First : constant Node_Id :=
1610 First (Parameter_Associations (Original_Node (N)));
1616 Old_Sec := Next (Old_First);
1618 -- If the original call has named associations, replace the
1619 -- explicit actual parameter in the association with the proper
1620 -- resolved operand.
1622 if Nkind (Old_First) = N_Parameter_Association then
1623 if Chars (Selector_Name (Old_First)) =
1624 Chars (First_Entity (Op_Id))
1626 Rewrite (Explicit_Actual_Parameter (Old_First),
1629 Rewrite (Explicit_Actual_Parameter (Old_First),
1634 Rewrite (Old_First, Relocate_Node (L));
1637 if Nkind (Old_Sec) = N_Parameter_Association then
1638 if Chars (Selector_Name (Old_Sec)) =
1639 Chars (First_Entity (Op_Id))
1641 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1644 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1649 Rewrite (Old_Sec, Relocate_Node (R));
1653 if Nkind (Old_First) = N_Parameter_Association then
1654 Rewrite (Explicit_Actual_Parameter (Old_First),
1657 Rewrite (Old_First, Relocate_Node (R));
1662 Set_Parent (Original_Node (N), Parent (N));
1664 end Make_Call_Into_Operator;
1670 function Operator_Kind
1672 Is_Binary : Boolean) return Node_Kind
1677 -- Use CASE statement or array???
1680 if Op_Name = Name_Op_And then
1682 elsif Op_Name = Name_Op_Or then
1684 elsif Op_Name = Name_Op_Xor then
1686 elsif Op_Name = Name_Op_Eq then
1688 elsif Op_Name = Name_Op_Ne then
1690 elsif Op_Name = Name_Op_Lt then
1692 elsif Op_Name = Name_Op_Le then
1694 elsif Op_Name = Name_Op_Gt then
1696 elsif Op_Name = Name_Op_Ge then
1698 elsif Op_Name = Name_Op_Add then
1700 elsif Op_Name = Name_Op_Subtract then
1701 Kind := N_Op_Subtract;
1702 elsif Op_Name = Name_Op_Concat then
1703 Kind := N_Op_Concat;
1704 elsif Op_Name = Name_Op_Multiply then
1705 Kind := N_Op_Multiply;
1706 elsif Op_Name = Name_Op_Divide then
1707 Kind := N_Op_Divide;
1708 elsif Op_Name = Name_Op_Mod then
1710 elsif Op_Name = Name_Op_Rem then
1712 elsif Op_Name = Name_Op_Expon then
1715 raise Program_Error;
1721 if Op_Name = Name_Op_Add then
1723 elsif Op_Name = Name_Op_Subtract then
1725 elsif Op_Name = Name_Op_Abs then
1727 elsif Op_Name = Name_Op_Not then
1730 raise Program_Error;
1737 ----------------------------
1738 -- Preanalyze_And_Resolve --
1739 ----------------------------
1741 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1742 Save_Full_Analysis : constant Boolean := Full_Analysis;
1745 Full_Analysis := False;
1746 Expander_Mode_Save_And_Set (False);
1748 -- Normally, we suppress all checks for this preanalysis. There is no
1749 -- point in processing them now, since they will be applied properly
1750 -- and in the proper location when the default expressions reanalyzed
1751 -- and reexpanded later on. We will also have more information at that
1752 -- point for possible suppression of individual checks.
1754 -- However, in SPARK mode, most expansion is suppressed, and this
1755 -- later reanalysis and reexpansion may not occur. SPARK mode does
1756 -- require the setting of checking flags for proof purposes, so we
1757 -- do the SPARK preanalysis without suppressing checks.
1759 -- This special handling for SPARK mode is required for example in the
1760 -- case of Ada 2012 constructs such as quantified expressions, which are
1761 -- expanded in two separate steps.
1763 if GNATprove_Mode then
1764 Analyze_And_Resolve (N, T);
1766 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1769 Expander_Mode_Restore;
1770 Full_Analysis := Save_Full_Analysis;
1771 end Preanalyze_And_Resolve;
1773 -- Version without context type
1775 procedure Preanalyze_And_Resolve (N : Node_Id) is
1776 Save_Full_Analysis : constant Boolean := Full_Analysis;
1779 Full_Analysis := False;
1780 Expander_Mode_Save_And_Set (False);
1783 Resolve (N, Etype (N), Suppress => All_Checks);
1785 Expander_Mode_Restore;
1786 Full_Analysis := Save_Full_Analysis;
1787 end Preanalyze_And_Resolve;
1789 ----------------------------------
1790 -- Replace_Actual_Discriminants --
1791 ----------------------------------
1793 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1794 Loc : constant Source_Ptr := Sloc (N);
1795 Tsk : Node_Id := Empty;
1797 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1798 -- Comment needed???
1804 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1808 if Nkind (Nod) = N_Identifier then
1809 Ent := Entity (Nod);
1812 and then Ekind (Ent) = E_Discriminant
1815 Make_Selected_Component (Loc,
1816 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1817 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1819 Set_Etype (Nod, Etype (Ent));
1827 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1829 -- Start of processing for Replace_Actual_Discriminants
1832 if not Expander_Active then
1836 if Nkind (Name (N)) = N_Selected_Component then
1837 Tsk := Prefix (Name (N));
1839 elsif Nkind (Name (N)) = N_Indexed_Component then
1840 Tsk := Prefix (Prefix (Name (N)));
1846 Replace_Discrs (Default);
1848 end Replace_Actual_Discriminants;
1854 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1855 Ambiguous : Boolean := False;
1856 Ctx_Type : Entity_Id := Typ;
1857 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1858 Err_Type : Entity_Id := Empty;
1859 Found : Boolean := False;
1862 I1 : Interp_Index := 0; -- prevent junk warning
1865 Seen : Entity_Id := Empty; -- prevent junk warning
1867 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1868 -- Determine whether a node comes from a predefined library unit or
1871 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1872 -- Try and fix up a literal so that it matches its expected type. New
1873 -- literals are manufactured if necessary to avoid cascaded errors.
1875 procedure Report_Ambiguous_Argument;
1876 -- Additional diagnostics when an ambiguous call has an ambiguous
1877 -- argument (typically a controlling actual).
1879 procedure Resolution_Failed;
1880 -- Called when attempt at resolving current expression fails
1882 ------------------------------------
1883 -- Comes_From_Predefined_Lib_Unit --
1884 -------------------------------------
1886 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1889 Sloc (Nod) = Standard_Location
1890 or else Is_Predefined_File_Name
1891 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1892 end Comes_From_Predefined_Lib_Unit;
1894 --------------------
1895 -- Patch_Up_Value --
1896 --------------------
1898 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1900 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1902 Make_Real_Literal (Sloc (N),
1903 Realval => UR_From_Uint (Intval (N))));
1904 Set_Etype (N, Universal_Real);
1905 Set_Is_Static_Expression (N);
1907 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1909 Make_Integer_Literal (Sloc (N),
1910 Intval => UR_To_Uint (Realval (N))));
1911 Set_Etype (N, Universal_Integer);
1912 Set_Is_Static_Expression (N);
1914 elsif Nkind (N) = N_String_Literal
1915 and then Is_Character_Type (Typ)
1917 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1919 Make_Character_Literal (Sloc (N),
1921 Char_Literal_Value =>
1922 UI_From_Int (Character'Pos ('A'))));
1923 Set_Etype (N, Any_Character);
1924 Set_Is_Static_Expression (N);
1926 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1928 Make_String_Literal (Sloc (N),
1929 Strval => End_String));
1931 elsif Nkind (N) = N_Range then
1932 Patch_Up_Value (Low_Bound (N), Typ);
1933 Patch_Up_Value (High_Bound (N), Typ);
1937 -------------------------------
1938 -- Report_Ambiguous_Argument --
1939 -------------------------------
1941 procedure Report_Ambiguous_Argument is
1942 Arg : constant Node_Id := First (Parameter_Associations (N));
1947 if Nkind (Arg) = N_Function_Call
1948 and then Is_Entity_Name (Name (Arg))
1949 and then Is_Overloaded (Name (Arg))
1951 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1953 -- Could use comments on what is going on here???
1955 Get_First_Interp (Name (Arg), I, It);
1956 while Present (It.Nam) loop
1957 Error_Msg_Sloc := Sloc (It.Nam);
1959 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1960 Error_Msg_N ("interpretation (inherited) #!", Arg);
1962 Error_Msg_N ("interpretation #!", Arg);
1965 Get_Next_Interp (I, It);
1968 end Report_Ambiguous_Argument;
1970 -----------------------
1971 -- Resolution_Failed --
1972 -----------------------
1974 procedure Resolution_Failed is
1976 Patch_Up_Value (N, Typ);
1978 -- Set the type to the desired one to minimize cascaded errors. Note
1979 -- that this is an approximation and does not work in all cases.
1983 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1984 Set_Is_Overloaded (N, False);
1986 -- The caller will return without calling the expander, so we need
1987 -- to set the analyzed flag. Note that it is fine to set Analyzed
1988 -- to True even if we are in the middle of a shallow analysis,
1989 -- (see the spec of sem for more details) since this is an error
1990 -- situation anyway, and there is no point in repeating the
1991 -- analysis later (indeed it won't work to repeat it later, since
1992 -- we haven't got a clear resolution of which entity is being
1995 Set_Analyzed (N, True);
1997 end Resolution_Failed;
2001 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
2003 -- Start of processing for Resolve
2010 -- A declaration may be subject to pragma Ghost. Set the mode now to
2011 -- ensure that any nodes generated during analysis and expansion are
2014 if Is_Declaration (N) then
2018 -- Access attribute on remote subprogram cannot be used for a non-remote
2019 -- access-to-subprogram type.
2021 if Nkind (N) = N_Attribute_Reference
2022 and then Nam_In (Attribute_Name (N), Name_Access,
2023 Name_Unrestricted_Access,
2024 Name_Unchecked_Access)
2025 and then Comes_From_Source (N)
2026 and then Is_Entity_Name (Prefix (N))
2027 and then Is_Subprogram (Entity (Prefix (N)))
2028 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2029 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2032 ("prefix must statically denote a non-remote subprogram", N);
2035 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2037 -- If the context is a Remote_Access_To_Subprogram, access attributes
2038 -- must be resolved with the corresponding fat pointer. There is no need
2039 -- to check for the attribute name since the return type of an
2040 -- attribute is never a remote type.
2042 if Nkind (N) = N_Attribute_Reference
2043 and then Comes_From_Source (N)
2044 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2047 Attr : constant Attribute_Id :=
2048 Get_Attribute_Id (Attribute_Name (N));
2049 Pref : constant Node_Id := Prefix (N);
2052 Is_Remote : Boolean := True;
2055 -- Check that Typ is a remote access-to-subprogram type
2057 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2059 -- Prefix (N) must statically denote a remote subprogram
2060 -- declared in a package specification.
2062 if Attr = Attribute_Access or else
2063 Attr = Attribute_Unchecked_Access or else
2064 Attr = Attribute_Unrestricted_Access
2066 Decl := Unit_Declaration_Node (Entity (Pref));
2068 if Nkind (Decl) = N_Subprogram_Body then
2069 Spec := Corresponding_Spec (Decl);
2071 if Present (Spec) then
2072 Decl := Unit_Declaration_Node (Spec);
2076 Spec := Parent (Decl);
2078 if not Is_Entity_Name (Prefix (N))
2079 or else Nkind (Spec) /= N_Package_Specification
2081 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2085 ("prefix must statically denote a remote subprogram ",
2089 -- If we are generating code in distributed mode, perform
2090 -- semantic checks against corresponding remote entities.
2093 and then Get_PCS_Name /= Name_No_DSA
2095 Check_Subtype_Conformant
2096 (New_Id => Entity (Prefix (N)),
2097 Old_Id => Designated_Type
2098 (Corresponding_Remote_Type (Typ)),
2102 Process_Remote_AST_Attribute (N, Typ);
2110 Debug_A_Entry ("resolving ", N);
2112 if Debug_Flag_V then
2113 Write_Overloads (N);
2116 if Comes_From_Source (N) then
2117 if Is_Fixed_Point_Type (Typ) then
2118 Check_Restriction (No_Fixed_Point, N);
2120 elsif Is_Floating_Point_Type (Typ)
2121 and then Typ /= Universal_Real
2122 and then Typ /= Any_Real
2124 Check_Restriction (No_Floating_Point, N);
2128 -- Return if already analyzed
2130 if Analyzed (N) then
2131 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2132 Analyze_Dimension (N);
2133 Ghost_Mode := Save_Ghost_Mode;
2136 -- Any case of Any_Type as the Etype value means that we had a
2139 elsif Etype (N) = Any_Type then
2140 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2141 Ghost_Mode := Save_Ghost_Mode;
2145 Check_Parameterless_Call (N);
2147 -- The resolution of an Expression_With_Actions is determined by
2150 if Nkind (N) = N_Expression_With_Actions then
2151 Resolve (Expression (N), Typ);
2154 Expr_Type := Etype (Expression (N));
2156 -- If not overloaded, then we know the type, and all that needs doing
2157 -- is to check that this type is compatible with the context.
2159 elsif not Is_Overloaded (N) then
2160 Found := Covers (Typ, Etype (N));
2161 Expr_Type := Etype (N);
2163 -- In the overloaded case, we must select the interpretation that
2164 -- is compatible with the context (i.e. the type passed to Resolve)
2167 -- Loop through possible interpretations
2169 Get_First_Interp (N, I, It);
2170 Interp_Loop : while Present (It.Typ) loop
2171 if Debug_Flag_V then
2172 Write_Str ("Interp: ");
2176 -- We are only interested in interpretations that are compatible
2177 -- with the expected type, any other interpretations are ignored.
2179 if not Covers (Typ, It.Typ) then
2180 if Debug_Flag_V then
2181 Write_Str (" interpretation incompatible with context");
2186 -- Skip the current interpretation if it is disabled by an
2187 -- abstract operator. This action is performed only when the
2188 -- type against which we are resolving is the same as the
2189 -- type of the interpretation.
2191 if Ada_Version >= Ada_2005
2192 and then It.Typ = Typ
2193 and then Typ /= Universal_Integer
2194 and then Typ /= Universal_Real
2195 and then Present (It.Abstract_Op)
2197 if Debug_Flag_V then
2198 Write_Line ("Skip.");
2204 -- First matching interpretation
2210 Expr_Type := It.Typ;
2212 -- Matching interpretation that is not the first, maybe an
2213 -- error, but there are some cases where preference rules are
2214 -- used to choose between the two possibilities. These and
2215 -- some more obscure cases are handled in Disambiguate.
2218 -- If the current statement is part of a predefined library
2219 -- unit, then all interpretations which come from user level
2220 -- packages should not be considered. Check previous and
2224 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2227 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2229 -- Previous interpretation must be discarded
2233 Expr_Type := It.Typ;
2234 Set_Entity (N, Seen);
2239 -- Otherwise apply further disambiguation steps
2241 Error_Msg_Sloc := Sloc (Seen);
2242 It1 := Disambiguate (N, I1, I, Typ);
2244 -- Disambiguation has succeeded. Skip the remaining
2247 if It1 /= No_Interp then
2249 Expr_Type := It1.Typ;
2251 while Present (It.Typ) loop
2252 Get_Next_Interp (I, It);
2256 -- Before we issue an ambiguity complaint, check for the
2257 -- case of a subprogram call where at least one of the
2258 -- arguments is Any_Type, and if so suppress the message,
2259 -- since it is a cascaded error. This can also happen for
2260 -- a generalized indexing operation.
2262 if Nkind (N) in N_Subprogram_Call
2263 or else (Nkind (N) = N_Indexed_Component
2264 and then Present (Generalized_Indexing (N)))
2271 if Nkind (N) = N_Indexed_Component then
2272 Rewrite (N, Generalized_Indexing (N));
2275 A := First_Actual (N);
2276 while Present (A) loop
2279 if Nkind (E) = N_Parameter_Association then
2280 E := Explicit_Actual_Parameter (E);
2283 if Etype (E) = Any_Type then
2284 if Debug_Flag_V then
2285 Write_Str ("Any_Type in call");
2296 elsif Nkind (N) in N_Binary_Op
2297 and then (Etype (Left_Opnd (N)) = Any_Type
2298 or else Etype (Right_Opnd (N)) = Any_Type)
2302 elsif Nkind (N) in N_Unary_Op
2303 and then Etype (Right_Opnd (N)) = Any_Type
2308 -- Not that special case, so issue message using the flag
2309 -- Ambiguous to control printing of the header message
2310 -- only at the start of an ambiguous set.
2312 if not Ambiguous then
2313 if Nkind (N) = N_Function_Call
2314 and then Nkind (Name (N)) = N_Explicit_Dereference
2317 ("ambiguous expression (cannot resolve indirect "
2320 Error_Msg_NE -- CODEFIX
2321 ("ambiguous expression (cannot resolve&)!",
2327 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2329 ("\\possible interpretation (inherited)#!", N);
2331 Error_Msg_N -- CODEFIX
2332 ("\\possible interpretation#!", N);
2335 if Nkind (N) in N_Subprogram_Call
2336 and then Present (Parameter_Associations (N))
2338 Report_Ambiguous_Argument;
2342 Error_Msg_Sloc := Sloc (It.Nam);
2344 -- By default, the error message refers to the candidate
2345 -- interpretation. But if it is a predefined operator, it
2346 -- is implicitly declared at the declaration of the type
2347 -- of the operand. Recover the sloc of that declaration
2348 -- for the error message.
2350 if Nkind (N) in N_Op
2351 and then Scope (It.Nam) = Standard_Standard
2352 and then not Is_Overloaded (Right_Opnd (N))
2353 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2356 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2358 if Comes_From_Source (Err_Type)
2359 and then Present (Parent (Err_Type))
2361 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2364 elsif Nkind (N) in N_Binary_Op
2365 and then Scope (It.Nam) = Standard_Standard
2366 and then not Is_Overloaded (Left_Opnd (N))
2367 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2370 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2372 if Comes_From_Source (Err_Type)
2373 and then Present (Parent (Err_Type))
2375 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2378 -- If this is an indirect call, use the subprogram_type
2379 -- in the message, to have a meaningful location. Also
2380 -- indicate if this is an inherited operation, created
2381 -- by a type declaration.
2383 elsif Nkind (N) = N_Function_Call
2384 and then Nkind (Name (N)) = N_Explicit_Dereference
2385 and then Is_Type (It.Nam)
2389 Sloc (Associated_Node_For_Itype (Err_Type));
2394 if Nkind (N) in N_Op
2395 and then Scope (It.Nam) = Standard_Standard
2396 and then Present (Err_Type)
2398 -- Special-case the message for universal_fixed
2399 -- operators, which are not declared with the type
2400 -- of the operand, but appear forever in Standard.
2402 if It.Typ = Universal_Fixed
2403 and then Scope (It.Nam) = Standard_Standard
2406 ("\\possible interpretation as universal_fixed "
2407 & "operation (RM 4.5.5 (19))", N);
2410 ("\\possible interpretation (predefined)#!", N);
2414 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2417 ("\\possible interpretation (inherited)#!", N);
2419 Error_Msg_N -- CODEFIX
2420 ("\\possible interpretation#!", N);
2426 -- We have a matching interpretation, Expr_Type is the type
2427 -- from this interpretation, and Seen is the entity.
2429 -- For an operator, just set the entity name. The type will be
2430 -- set by the specific operator resolution routine.
2432 if Nkind (N) in N_Op then
2433 Set_Entity (N, Seen);
2434 Generate_Reference (Seen, N);
2436 elsif Nkind (N) = N_Case_Expression then
2437 Set_Etype (N, Expr_Type);
2439 elsif Nkind (N) = N_Character_Literal then
2440 Set_Etype (N, Expr_Type);
2442 elsif Nkind (N) = N_If_Expression then
2443 Set_Etype (N, Expr_Type);
2445 -- AI05-0139-2: Expression is overloaded because type has
2446 -- implicit dereference. If type matches context, no implicit
2447 -- dereference is involved.
2449 elsif Has_Implicit_Dereference (Expr_Type) then
2450 Set_Etype (N, Expr_Type);
2451 Set_Is_Overloaded (N, False);
2454 elsif Is_Overloaded (N)
2455 and then Present (It.Nam)
2456 and then Ekind (It.Nam) = E_Discriminant
2457 and then Has_Implicit_Dereference (It.Nam)
2459 -- If the node is a general indexing, the dereference is
2460 -- is inserted when resolving the rewritten form, else
2463 if Nkind (N) /= N_Indexed_Component
2464 or else No (Generalized_Indexing (N))
2466 Build_Explicit_Dereference (N, It.Nam);
2469 -- For an explicit dereference, attribute reference, range,
2470 -- short-circuit form (which is not an operator node), or call
2471 -- with a name that is an explicit dereference, there is
2472 -- nothing to be done at this point.
2474 elsif Nkind_In (N, N_Explicit_Dereference,
2475 N_Attribute_Reference,
2477 N_Indexed_Component,
2480 N_Selected_Component,
2482 or else Nkind (Name (N)) = N_Explicit_Dereference
2486 -- For procedure or function calls, set the type of the name,
2487 -- and also the entity pointer for the prefix.
2489 elsif Nkind (N) in N_Subprogram_Call
2490 and then Is_Entity_Name (Name (N))
2492 Set_Etype (Name (N), Expr_Type);
2493 Set_Entity (Name (N), Seen);
2494 Generate_Reference (Seen, Name (N));
2496 elsif Nkind (N) = N_Function_Call
2497 and then Nkind (Name (N)) = N_Selected_Component
2499 Set_Etype (Name (N), Expr_Type);
2500 Set_Entity (Selector_Name (Name (N)), Seen);
2501 Generate_Reference (Seen, Selector_Name (Name (N)));
2503 -- For all other cases, just set the type of the Name
2506 Set_Etype (Name (N), Expr_Type);
2513 -- Move to next interpretation
2515 exit Interp_Loop when No (It.Typ);
2517 Get_Next_Interp (I, It);
2518 end loop Interp_Loop;
2521 -- At this stage Found indicates whether or not an acceptable
2522 -- interpretation exists. If not, then we have an error, except that if
2523 -- the context is Any_Type as a result of some other error, then we
2524 -- suppress the error report.
2527 if Typ /= Any_Type then
2529 -- If type we are looking for is Void, then this is the procedure
2530 -- call case, and the error is simply that what we gave is not a
2531 -- procedure name (we think of procedure calls as expressions with
2532 -- types internally, but the user doesn't think of them this way).
2534 if Typ = Standard_Void_Type then
2536 -- Special case message if function used as a procedure
2538 if Nkind (N) = N_Procedure_Call_Statement
2539 and then Is_Entity_Name (Name (N))
2540 and then Ekind (Entity (Name (N))) = E_Function
2543 ("cannot use function & in a procedure call",
2544 Name (N), Entity (Name (N)));
2546 -- Otherwise give general message (not clear what cases this
2547 -- covers, but no harm in providing for them).
2550 Error_Msg_N ("expect procedure name in procedure call", N);
2555 -- Otherwise we do have a subexpression with the wrong type
2557 -- Check for the case of an allocator which uses an access type
2558 -- instead of the designated type. This is a common error and we
2559 -- specialize the message, posting an error on the operand of the
2560 -- allocator, complaining that we expected the designated type of
2563 elsif Nkind (N) = N_Allocator
2564 and then Is_Access_Type (Typ)
2565 and then Is_Access_Type (Etype (N))
2566 and then Designated_Type (Etype (N)) = Typ
2568 Wrong_Type (Expression (N), Designated_Type (Typ));
2571 -- Check for view mismatch on Null in instances, for which the
2572 -- view-swapping mechanism has no identifier.
2574 elsif (In_Instance or else In_Inlined_Body)
2575 and then (Nkind (N) = N_Null)
2576 and then Is_Private_Type (Typ)
2577 and then Is_Access_Type (Full_View (Typ))
2579 Resolve (N, Full_View (Typ));
2581 Ghost_Mode := Save_Ghost_Mode;
2584 -- Check for an aggregate. Sometimes we can get bogus aggregates
2585 -- from misuse of parentheses, and we are about to complain about
2586 -- the aggregate without even looking inside it.
2588 -- Instead, if we have an aggregate of type Any_Composite, then
2589 -- analyze and resolve the component fields, and then only issue
2590 -- another message if we get no errors doing this (otherwise
2591 -- assume that the errors in the aggregate caused the problem).
2593 elsif Nkind (N) = N_Aggregate
2594 and then Etype (N) = Any_Composite
2596 -- Disable expansion in any case. If there is a type mismatch
2597 -- it may be fatal to try to expand the aggregate. The flag
2598 -- would otherwise be set to false when the error is posted.
2600 Expander_Active := False;
2603 procedure Check_Aggr (Aggr : Node_Id);
2604 -- Check one aggregate, and set Found to True if we have a
2605 -- definite error in any of its elements
2607 procedure Check_Elmt (Aelmt : Node_Id);
2608 -- Check one element of aggregate and set Found to True if
2609 -- we definitely have an error in the element.
2615 procedure Check_Aggr (Aggr : Node_Id) is
2619 if Present (Expressions (Aggr)) then
2620 Elmt := First (Expressions (Aggr));
2621 while Present (Elmt) loop
2627 if Present (Component_Associations (Aggr)) then
2628 Elmt := First (Component_Associations (Aggr));
2629 while Present (Elmt) loop
2631 -- If this is a default-initialized component, then
2632 -- there is nothing to check. The box will be
2633 -- replaced by the appropriate call during late
2636 if not Box_Present (Elmt) then
2637 Check_Elmt (Expression (Elmt));
2649 procedure Check_Elmt (Aelmt : Node_Id) is
2651 -- If we have a nested aggregate, go inside it (to
2652 -- attempt a naked analyze-resolve of the aggregate can
2653 -- cause undesirable cascaded errors). Do not resolve
2654 -- expression if it needs a type from context, as for
2655 -- integer * fixed expression.
2657 if Nkind (Aelmt) = N_Aggregate then
2663 if not Is_Overloaded (Aelmt)
2664 and then Etype (Aelmt) /= Any_Fixed
2669 if Etype (Aelmt) = Any_Type then
2680 -- Looks like we have a type error, but check for special case
2681 -- of Address wanted, integer found, with the configuration pragma
2682 -- Allow_Integer_Address active. If we have this case, introduce
2683 -- an unchecked conversion to allow the integer expression to be
2684 -- treated as an Address. The reverse case of integer wanted,
2685 -- Address found, is treated in an analogous manner.
2687 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2688 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2689 Analyze_And_Resolve (N, Typ);
2690 Ghost_Mode := Save_Ghost_Mode;
2693 -- Under relaxed RM semantics silently replace occurrences of null
2694 -- by System.Address_Null.
2696 elsif Null_To_Null_Address_Convert_OK (N, Typ) then
2697 Replace_Null_By_Null_Address (N);
2698 Analyze_And_Resolve (N, Typ);
2702 -- That special Allow_Integer_Address check did not apply, so we
2703 -- have a real type error. If an error message was issued already,
2704 -- Found got reset to True, so if it's still False, issue standard
2705 -- Wrong_Type message.
2708 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2710 Subp_Name : Node_Id;
2713 if Is_Entity_Name (Name (N)) then
2714 Subp_Name := Name (N);
2716 elsif Nkind (Name (N)) = N_Selected_Component then
2718 -- Protected operation: retrieve operation name
2720 Subp_Name := Selector_Name (Name (N));
2723 raise Program_Error;
2726 Error_Msg_Node_2 := Typ;
2728 ("no visible interpretation of& "
2729 & "matches expected type&", N, Subp_Name);
2732 if All_Errors_Mode then
2734 Index : Interp_Index;
2738 Error_Msg_N ("\\possible interpretations:", N);
2740 Get_First_Interp (Name (N), Index, It);
2741 while Present (It.Nam) loop
2742 Error_Msg_Sloc := Sloc (It.Nam);
2743 Error_Msg_Node_2 := It.Nam;
2745 ("\\ type& for & declared#", N, It.Typ);
2746 Get_Next_Interp (Index, It);
2751 Error_Msg_N ("\use -gnatf for details", N);
2755 Wrong_Type (N, Typ);
2761 Ghost_Mode := Save_Ghost_Mode;
2764 -- Test if we have more than one interpretation for the context
2766 elsif Ambiguous then
2768 Ghost_Mode := Save_Ghost_Mode;
2771 -- Only one intepretation
2774 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2775 -- the "+" on T is abstract, and the operands are of universal type,
2776 -- the above code will have (incorrectly) resolved the "+" to the
2777 -- universal one in Standard. Therefore check for this case and give
2778 -- an error. We can't do this earlier, because it would cause legal
2779 -- cases to get errors (when some other type has an abstract "+").
2781 if Ada_Version >= Ada_2005
2782 and then Nkind (N) in N_Op
2783 and then Is_Overloaded (N)
2784 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2786 Get_First_Interp (N, I, It);
2787 while Present (It.Typ) loop
2788 if Present (It.Abstract_Op) and then
2789 Etype (It.Abstract_Op) = Typ
2792 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2796 Get_Next_Interp (I, It);
2800 -- Here we have an acceptable interpretation for the context
2802 -- Propagate type information and normalize tree for various
2803 -- predefined operations. If the context only imposes a class of
2804 -- types, rather than a specific type, propagate the actual type
2807 if Typ = Any_Integer or else
2808 Typ = Any_Boolean or else
2809 Typ = Any_Modular or else
2810 Typ = Any_Real or else
2813 Ctx_Type := Expr_Type;
2815 -- Any_Fixed is legal in a real context only if a specific fixed-
2816 -- point type is imposed. If Norman Cohen can be confused by this,
2817 -- it deserves a separate message.
2820 and then Expr_Type = Any_Fixed
2822 Error_Msg_N ("illegal context for mixed mode operation", N);
2823 Set_Etype (N, Universal_Real);
2824 Ctx_Type := Universal_Real;
2828 -- A user-defined operator is transformed into a function call at
2829 -- this point, so that further processing knows that operators are
2830 -- really operators (i.e. are predefined operators). User-defined
2831 -- operators that are intrinsic are just renamings of the predefined
2832 -- ones, and need not be turned into calls either, but if they rename
2833 -- a different operator, we must transform the node accordingly.
2834 -- Instantiations of Unchecked_Conversion are intrinsic but are
2835 -- treated as functions, even if given an operator designator.
2837 if Nkind (N) in N_Op
2838 and then Present (Entity (N))
2839 and then Ekind (Entity (N)) /= E_Operator
2842 if not Is_Predefined_Op (Entity (N)) then
2843 Rewrite_Operator_As_Call (N, Entity (N));
2845 elsif Present (Alias (Entity (N)))
2847 Nkind (Parent (Parent (Entity (N)))) =
2848 N_Subprogram_Renaming_Declaration
2850 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2852 -- If the node is rewritten, it will be fully resolved in
2853 -- Rewrite_Renamed_Operator.
2855 if Analyzed (N) then
2856 Ghost_Mode := Save_Ghost_Mode;
2862 case N_Subexpr'(Nkind (N)) is
2864 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2866 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2868 when N_Short_Circuit
2869 => Resolve_Short_Circuit (N, Ctx_Type);
2871 when N_Attribute_Reference
2872 => Resolve_Attribute (N, Ctx_Type);
2874 when N_Case_Expression
2875 => Resolve_Case_Expression (N, Ctx_Type);
2877 when N_Character_Literal
2878 => Resolve_Character_Literal (N, Ctx_Type);
2880 when N_Expanded_Name
2881 => Resolve_Entity_Name (N, Ctx_Type);
2883 when N_Explicit_Dereference
2884 => Resolve_Explicit_Dereference (N, Ctx_Type);
2886 when N_Expression_With_Actions
2887 => Resolve_Expression_With_Actions (N, Ctx_Type);
2889 when N_Extension_Aggregate
2890 => Resolve_Extension_Aggregate (N, Ctx_Type);
2892 when N_Function_Call
2893 => Resolve_Call (N, Ctx_Type);
2896 => Resolve_Entity_Name (N, Ctx_Type);
2898 when N_If_Expression
2899 => Resolve_If_Expression (N, Ctx_Type);
2901 when N_Indexed_Component
2902 => Resolve_Indexed_Component (N, Ctx_Type);
2904 when N_Integer_Literal
2905 => Resolve_Integer_Literal (N, Ctx_Type);
2907 when N_Membership_Test
2908 => Resolve_Membership_Op (N, Ctx_Type);
2910 when N_Null => Resolve_Null (N, Ctx_Type);
2912 when N_Op_And | N_Op_Or | N_Op_Xor
2913 => Resolve_Logical_Op (N, Ctx_Type);
2915 when N_Op_Eq | N_Op_Ne
2916 => Resolve_Equality_Op (N, Ctx_Type);
2918 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2919 => Resolve_Comparison_Op (N, Ctx_Type);
2921 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2923 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2924 N_Op_Divide | N_Op_Mod | N_Op_Rem
2926 => Resolve_Arithmetic_Op (N, Ctx_Type);
2928 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2930 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2932 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2933 => Resolve_Unary_Op (N, Ctx_Type);
2935 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2937 when N_Procedure_Call_Statement
2938 => Resolve_Call (N, Ctx_Type);
2940 when N_Operator_Symbol
2941 => Resolve_Operator_Symbol (N, Ctx_Type);
2943 when N_Qualified_Expression
2944 => Resolve_Qualified_Expression (N, Ctx_Type);
2946 -- Why is the following null, needs a comment ???
2948 when N_Quantified_Expression
2951 when N_Raise_Expression
2952 => Resolve_Raise_Expression (N, Ctx_Type);
2954 when N_Raise_xxx_Error
2955 => Set_Etype (N, Ctx_Type);
2957 when N_Range => Resolve_Range (N, Ctx_Type);
2960 => Resolve_Real_Literal (N, Ctx_Type);
2962 when N_Reference => Resolve_Reference (N, Ctx_Type);
2964 when N_Selected_Component
2965 => Resolve_Selected_Component (N, Ctx_Type);
2967 when N_Slice => Resolve_Slice (N, Ctx_Type);
2969 when N_String_Literal
2970 => Resolve_String_Literal (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 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2983 -- expression of an anonymous access type that occurs in the context
2984 -- of a named general access type, except when the expression is that
2985 -- of a membership test. This ensures proper legality checking in
2986 -- terms of allowed conversions (expressions that would be illegal to
2987 -- convert implicitly are allowed in membership tests).
2989 if Ada_Version >= Ada_2012
2990 and then Ekind (Ctx_Type) = E_General_Access_Type
2991 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2992 and then Nkind (Parent (N)) not in N_Membership_Test
2994 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2995 Analyze_And_Resolve (N, Ctx_Type);
2998 -- If the subexpression was replaced by a non-subexpression, then
2999 -- all we do is to expand it. The only legitimate case we know of
3000 -- is converting procedure call statement to entry call statements,
3001 -- but there may be others, so we are making this test general.
3003 if Nkind (N) not in N_Subexpr then
3004 Debug_A_Exit ("resolving ", N, " (done)");
3006 Ghost_Mode := Save_Ghost_Mode;
3010 -- The expression is definitely NOT overloaded at this point, so
3011 -- we reset the Is_Overloaded flag to avoid any confusion when
3012 -- reanalyzing the node.
3014 Set_Is_Overloaded (N, False);
3016 -- Freeze expression type, entity if it is a name, and designated
3017 -- type if it is an allocator (RM 13.14(10,11,13)).
3019 -- Now that the resolution of the type of the node is complete, and
3020 -- we did not detect an error, we can expand this node. We skip the
3021 -- expand call if we are in a default expression, see section
3022 -- "Handling of Default Expressions" in Sem spec.
3024 Debug_A_Exit ("resolving ", N, " (done)");
3026 -- We unconditionally freeze the expression, even if we are in
3027 -- default expression mode (the Freeze_Expression routine tests this
3028 -- flag and only freezes static types if it is set).
3030 -- Ada 2012 (AI05-177): The declaration of an expression function
3031 -- does not cause freezing, but we never reach here in that case.
3032 -- Here we are resolving the corresponding expanded body, so we do
3033 -- need to perform normal freezing.
3035 Freeze_Expression (N);
3037 -- Now we can do the expansion
3042 Ghost_Mode := Save_Ghost_Mode;
3049 -- Version with check(s) suppressed
3051 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3053 if Suppress = All_Checks then
3055 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3057 Scope_Suppress.Suppress := (others => True);
3059 Scope_Suppress.Suppress := Sva;
3064 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3066 Scope_Suppress.Suppress (Suppress) := True;
3068 Scope_Suppress.Suppress (Suppress) := Svg;
3077 -- Version with implicit type
3079 procedure Resolve (N : Node_Id) is
3081 Resolve (N, Etype (N));
3084 ---------------------
3085 -- Resolve_Actuals --
3086 ---------------------
3088 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3089 Loc : constant Source_Ptr := Sloc (N);
3095 Prev : Node_Id := Empty;
3099 Real_Subp : Entity_Id;
3100 -- If the subprogram being called is an inherited operation for
3101 -- a formal derived type in an instance, Real_Subp is the subprogram
3102 -- that will be called. It may have different formal names than the
3103 -- operation of the formal in the generic, so after actual is resolved
3104 -- the name of the actual in a named association must carry the name
3105 -- of the actual of the subprogram being called.
3107 procedure Check_Aliased_Parameter;
3108 -- Check rules on aliased parameters and related accessibility rules
3109 -- in (RM 3.10.2 (10.2-10.4)).
3111 procedure Check_Argument_Order;
3112 -- Performs a check for the case where the actuals are all simple
3113 -- identifiers that correspond to the formal names, but in the wrong
3114 -- order, which is considered suspicious and cause for a warning.
3116 procedure Check_Prefixed_Call;
3117 -- If the original node is an overloaded call in prefix notation,
3118 -- insert an 'Access or a dereference as needed over the first actual.
3119 -- Try_Object_Operation has already verified that there is a valid
3120 -- interpretation, but the form of the actual can only be determined
3121 -- once the primitive operation is identified.
3123 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id);
3124 -- Emit an error concerning the illegal usage of an effectively volatile
3125 -- object in interfering context (SPARK RM 7.13(12)).
3127 procedure Insert_Default;
3128 -- If the actual is missing in a call, insert in the actuals list
3129 -- an instance of the default expression. The insertion is always
3130 -- a named association.
3132 procedure Property_Error
3135 Prop_Nam : Name_Id);
3136 -- Emit an error concerning variable Var with entity Var_Id that has
3137 -- enabled property Prop_Nam when it acts as an actual parameter in a
3138 -- call and the corresponding formal parameter is of mode IN.
3140 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3141 -- Check whether T1 and T2, or their full views, are derived from a
3142 -- common type. Used to enforce the restrictions on array conversions
3145 function Static_Concatenation (N : Node_Id) return Boolean;
3146 -- Predicate to determine whether an actual that is a concatenation
3147 -- will be evaluated statically and does not need a transient scope.
3148 -- This must be determined before the actual is resolved and expanded
3149 -- because if needed the transient scope must be introduced earlier.
3151 -----------------------------
3152 -- Check_Aliased_Parameter --
3153 -----------------------------
3155 procedure Check_Aliased_Parameter is
3156 Nominal_Subt : Entity_Id;
3159 if Is_Aliased (F) then
3160 if Is_Tagged_Type (A_Typ) then
3163 elsif Is_Aliased_View (A) then
3164 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3165 Nominal_Subt := Base_Type (A_Typ);
3167 Nominal_Subt := A_Typ;
3170 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3173 -- In a generic body assume the worst for generic formals:
3174 -- they can have a constrained partial view (AI05-041).
3176 elsif Has_Discriminants (F_Typ)
3177 and then not Is_Constrained (F_Typ)
3178 and then not Has_Constrained_Partial_View (F_Typ)
3179 and then not Is_Generic_Type (F_Typ)
3184 Error_Msg_NE ("untagged actual does not match "
3185 & "aliased formal&", A, F);
3189 Error_Msg_NE ("actual for aliased formal& must be "
3190 & "aliased object", A, F);
3193 if Ekind (Nam) = E_Procedure then
3196 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3197 if Nkind (Parent (N)) = N_Type_Conversion
3198 and then Type_Access_Level (Etype (Parent (N))) <
3199 Object_Access_Level (A)
3201 Error_Msg_N ("aliased actual has wrong accessibility", A);
3204 elsif Nkind (Parent (N)) = N_Qualified_Expression
3205 and then Nkind (Parent (Parent (N))) = N_Allocator
3206 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3207 Object_Access_Level (A)
3210 ("aliased actual in allocator has wrong accessibility", A);
3213 end Check_Aliased_Parameter;
3215 --------------------------
3216 -- Check_Argument_Order --
3217 --------------------------
3219 procedure Check_Argument_Order is
3221 -- Nothing to do if no parameters, or original node is neither a
3222 -- function call nor a procedure call statement (happens in the
3223 -- operator-transformed-to-function call case), or the call does
3224 -- not come from source, or this warning is off.
3226 if not Warn_On_Parameter_Order
3227 or else No (Parameter_Associations (N))
3228 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3229 or else not Comes_From_Source (N)
3235 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3238 -- Nothing to do if only one parameter
3244 -- Here if at least two arguments
3247 Actuals : array (1 .. Nargs) of Node_Id;
3251 Wrong_Order : Boolean := False;
3252 -- Set True if an out of order case is found
3255 -- Collect identifier names of actuals, fail if any actual is
3256 -- not a simple identifier, and record max length of name.
3258 Actual := First (Parameter_Associations (N));
3259 for J in Actuals'Range loop
3260 if Nkind (Actual) /= N_Identifier then
3263 Actuals (J) := Actual;
3268 -- If we got this far, all actuals are identifiers and the list
3269 -- of their names is stored in the Actuals array.
3271 Formal := First_Formal (Nam);
3272 for J in Actuals'Range loop
3274 -- If we ran out of formals, that's odd, probably an error
3275 -- which will be detected elsewhere, but abandon the search.
3281 -- If name matches and is in order OK
3283 if Chars (Formal) = Chars (Actuals (J)) then
3287 -- If no match, see if it is elsewhere in list and if so
3288 -- flag potential wrong order if type is compatible.
3290 for K in Actuals'Range loop
3291 if Chars (Formal) = Chars (Actuals (K))
3293 Has_Compatible_Type (Actuals (K), Etype (Formal))
3295 Wrong_Order := True;
3305 <<Continue>> Next_Formal (Formal);
3308 -- If Formals left over, also probably an error, skip warning
3310 if Present (Formal) then
3314 -- Here we give the warning if something was out of order
3318 ("?P?actuals for this call may be in wrong order", N);
3322 end Check_Argument_Order;
3324 -------------------------
3325 -- Check_Prefixed_Call --
3326 -------------------------
3328 procedure Check_Prefixed_Call is
3329 Act : constant Node_Id := First_Actual (N);
3330 A_Type : constant Entity_Id := Etype (Act);
3331 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3332 Orig : constant Node_Id := Original_Node (N);
3336 -- Check whether the call is a prefixed call, with or without
3337 -- additional actuals.
3339 if Nkind (Orig) = N_Selected_Component
3341 (Nkind (Orig) = N_Indexed_Component
3342 and then Nkind (Prefix (Orig)) = N_Selected_Component
3343 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3344 and then Is_Entity_Name (Act)
3345 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3347 if Is_Access_Type (A_Type)
3348 and then not Is_Access_Type (F_Type)
3350 -- Introduce dereference on object in prefix
3353 Make_Explicit_Dereference (Sloc (Act),
3354 Prefix => Relocate_Node (Act));
3355 Rewrite (Act, New_A);
3358 elsif Is_Access_Type (F_Type)
3359 and then not Is_Access_Type (A_Type)
3361 -- Introduce an implicit 'Access in prefix
3363 if not Is_Aliased_View (Act) then
3365 ("object in prefixed call to& must be aliased "
3366 & "(RM 4.1.3 (13 1/2))",
3371 Make_Attribute_Reference (Loc,
3372 Attribute_Name => Name_Access,
3373 Prefix => Relocate_Node (Act)));
3378 end Check_Prefixed_Call;
3380 ---------------------------------------
3381 -- Flag_Effectively_Volatile_Objects --
3382 ---------------------------------------
3384 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id) is
3385 function Flag_Object (N : Node_Id) return Traverse_Result;
3386 -- Determine whether arbitrary node N denotes an effectively volatile
3387 -- object and if it does, emit an error.
3393 function Flag_Object (N : Node_Id) return Traverse_Result is
3397 -- Do not consider nested function calls because they have already
3398 -- been processed during their own resolution.
3400 if Nkind (N) = N_Function_Call then
3403 elsif Is_Entity_Name (N) and then Present (Entity (N)) then
3407 and then Is_Effectively_Volatile (Id)
3408 and then (Async_Writers_Enabled (Id)
3409 or else Effective_Reads_Enabled (Id))
3412 ("volatile object cannot appear in this context (SPARK "
3413 & "RM 7.1.3(11))", N);
3421 procedure Flag_Objects is new Traverse_Proc (Flag_Object);
3423 -- Start of processing for Flag_Effectively_Volatile_Objects
3426 Flag_Objects (Expr);
3427 end Flag_Effectively_Volatile_Objects;
3429 --------------------
3430 -- Insert_Default --
3431 --------------------
3433 procedure Insert_Default is
3438 -- Missing argument in call, nothing to insert
3440 if No (Default_Value (F)) then
3444 -- Note that we do a full New_Copy_Tree, so that any associated
3445 -- Itypes are properly copied. This may not be needed any more,
3446 -- but it does no harm as a safety measure. Defaults of a generic
3447 -- formal may be out of bounds of the corresponding actual (see
3448 -- cc1311b) and an additional check may be required.
3453 New_Scope => Current_Scope,
3456 -- Propagate dimension information, if any.
3458 Copy_Dimensions (Default_Value (F), Actval);
3460 if Is_Concurrent_Type (Scope (Nam))
3461 and then Has_Discriminants (Scope (Nam))
3463 Replace_Actual_Discriminants (N, Actval);
3466 if Is_Overloadable (Nam)
3467 and then Present (Alias (Nam))
3469 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3470 and then not Is_Tagged_Type (Etype (F))
3472 -- If default is a real literal, do not introduce a
3473 -- conversion whose effect may depend on the run-time
3474 -- size of universal real.
3476 if Nkind (Actval) = N_Real_Literal then
3477 Set_Etype (Actval, Base_Type (Etype (F)));
3479 Actval := Unchecked_Convert_To (Etype (F), Actval);
3483 if Is_Scalar_Type (Etype (F)) then
3484 Enable_Range_Check (Actval);
3487 Set_Parent (Actval, N);
3489 -- Resolve aggregates with their base type, to avoid scope
3490 -- anomalies: the subtype was first built in the subprogram
3491 -- declaration, and the current call may be nested.
3493 if Nkind (Actval) = N_Aggregate then
3494 Analyze_And_Resolve (Actval, Etype (F));
3496 Analyze_And_Resolve (Actval, Etype (Actval));
3500 Set_Parent (Actval, N);
3502 -- See note above concerning aggregates
3504 if Nkind (Actval) = N_Aggregate
3505 and then Has_Discriminants (Etype (Actval))
3507 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3509 -- Resolve entities with their own type, which may differ from
3510 -- the type of a reference in a generic context (the view
3511 -- swapping mechanism did not anticipate the re-analysis of
3512 -- default values in calls).
3514 elsif Is_Entity_Name (Actval) then
3515 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3518 Analyze_And_Resolve (Actval, Etype (Actval));
3522 -- If default is a tag indeterminate function call, propagate tag
3523 -- to obtain proper dispatching.
3525 if Is_Controlling_Formal (F)
3526 and then Nkind (Default_Value (F)) = N_Function_Call
3528 Set_Is_Controlling_Actual (Actval);
3532 -- If the default expression raises constraint error, then just
3533 -- silently replace it with an N_Raise_Constraint_Error node, since
3534 -- we already gave the warning on the subprogram spec. If node is
3535 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3536 -- the warnings removal machinery.
3538 if Raises_Constraint_Error (Actval)
3539 and then Nkind (Actval) /= N_Raise_Constraint_Error
3542 Make_Raise_Constraint_Error (Loc,
3543 Reason => CE_Range_Check_Failed));
3544 Set_Raises_Constraint_Error (Actval);
3545 Set_Etype (Actval, Etype (F));
3549 Make_Parameter_Association (Loc,
3550 Explicit_Actual_Parameter => Actval,
3551 Selector_Name => Make_Identifier (Loc, Chars (F)));
3553 -- Case of insertion is first named actual
3555 if No (Prev) or else
3556 Nkind (Parent (Prev)) /= N_Parameter_Association
3558 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3559 Set_First_Named_Actual (N, Actval);
3562 if No (Parameter_Associations (N)) then
3563 Set_Parameter_Associations (N, New_List (Assoc));
3565 Append (Assoc, Parameter_Associations (N));
3569 Insert_After (Prev, Assoc);
3572 -- Case of insertion is not first named actual
3575 Set_Next_Named_Actual
3576 (Assoc, Next_Named_Actual (Parent (Prev)));
3577 Set_Next_Named_Actual (Parent (Prev), Actval);
3578 Append (Assoc, Parameter_Associations (N));
3581 Mark_Rewrite_Insertion (Assoc);
3582 Mark_Rewrite_Insertion (Actval);
3587 --------------------
3588 -- Property_Error --
3589 --------------------
3591 procedure Property_Error
3597 Error_Msg_Name_1 := Prop_Nam;
3599 ("external variable & with enabled property % cannot appear as "
3600 & "actual in procedure call (SPARK RM 7.1.3(10))", Var, Var_Id);
3601 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3608 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3609 FT1 : Entity_Id := T1;
3610 FT2 : Entity_Id := T2;
3613 if Is_Private_Type (T1)
3614 and then Present (Full_View (T1))
3616 FT1 := Full_View (T1);
3619 if Is_Private_Type (T2)
3620 and then Present (Full_View (T2))
3622 FT2 := Full_View (T2);
3625 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3628 --------------------------
3629 -- Static_Concatenation --
3630 --------------------------
3632 function Static_Concatenation (N : Node_Id) return Boolean is
3635 when N_String_Literal =>
3640 -- Concatenation is static when both operands are static and
3641 -- the concatenation operator is a predefined one.
3643 return Scope (Entity (N)) = Standard_Standard
3645 Static_Concatenation (Left_Opnd (N))
3647 Static_Concatenation (Right_Opnd (N));
3650 if Is_Entity_Name (N) then
3652 Ent : constant Entity_Id := Entity (N);
3654 return Ekind (Ent) = E_Constant
3655 and then Present (Constant_Value (Ent))
3657 Is_OK_Static_Expression (Constant_Value (Ent));
3664 end Static_Concatenation;
3666 -- Start of processing for Resolve_Actuals
3669 Check_Argument_Order;
3671 if Is_Overloadable (Nam)
3672 and then Is_Inherited_Operation (Nam)
3673 and then In_Instance
3674 and then Present (Alias (Nam))
3675 and then Present (Overridden_Operation (Alias (Nam)))
3677 Real_Subp := Alias (Nam);
3682 if Present (First_Actual (N)) then
3683 Check_Prefixed_Call;
3686 A := First_Actual (N);
3687 F := First_Formal (Nam);
3689 if Present (Real_Subp) then
3690 Real_F := First_Formal (Real_Subp);
3693 while Present (F) loop
3694 if No (A) and then Needs_No_Actuals (Nam) then
3697 -- If we have an error in any actual or formal, indicated by a type
3698 -- of Any_Type, then abandon resolution attempt, and set result type
3699 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3700 -- type is imposed from context.
3702 elsif (Present (A) and then Etype (A) = Any_Type)
3703 or else Etype (F) = Any_Type
3705 if Nkind (A) /= N_Raise_Expression then
3706 Set_Etype (N, Any_Type);
3711 -- Case where actual is present
3713 -- If the actual is an entity, generate a reference to it now. We
3714 -- do this before the actual is resolved, because a formal of some
3715 -- protected subprogram, or a task discriminant, will be rewritten
3716 -- during expansion, and the source entity reference may be lost.
3719 and then Is_Entity_Name (A)
3720 and then Comes_From_Source (A)
3722 Orig_A := Entity (A);
3724 if Present (Orig_A) then
3725 if Is_Formal (Orig_A)
3726 and then Ekind (F) /= E_In_Parameter
3728 Generate_Reference (Orig_A, A, 'm');
3730 elsif not Is_Overloaded (A) then
3731 if Ekind (F) /= E_Out_Parameter then
3732 Generate_Reference (Orig_A, A);
3734 -- RM 6.4.1(12): For an out parameter that is passed by
3735 -- copy, the formal parameter object is created, and:
3737 -- * For an access type, the formal parameter is initialized
3738 -- from the value of the actual, without checking that the
3739 -- value satisfies any constraint, any predicate, or any
3740 -- exclusion of the null value.
3742 -- * For a scalar type that has the Default_Value aspect
3743 -- specified, the formal parameter is initialized from the
3744 -- value of the actual, without checking that the value
3745 -- satisfies any constraint or any predicate.
3746 -- I do not understand why this case is included??? this is
3747 -- not a case where an OUT parameter is treated as IN OUT.
3749 -- * For a composite type with discriminants or that has
3750 -- implicit initial values for any subcomponents, the
3751 -- behavior is as for an in out parameter passed by copy.
3753 -- Hence for these cases we generate the read reference now
3754 -- (the write reference will be generated later by
3755 -- Note_Possible_Modification).
3757 elsif Is_By_Copy_Type (Etype (F))
3759 (Is_Access_Type (Etype (F))
3761 (Is_Scalar_Type (Etype (F))
3763 Present (Default_Aspect_Value (Etype (F))))
3765 (Is_Composite_Type (Etype (F))
3766 and then (Has_Discriminants (Etype (F))
3767 or else Is_Partially_Initialized_Type
3770 Generate_Reference (Orig_A, A);
3777 and then (Nkind (Parent (A)) /= N_Parameter_Association
3778 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3780 -- If style checking mode on, check match of formal name
3783 if Nkind (Parent (A)) = N_Parameter_Association then
3784 Check_Identifier (Selector_Name (Parent (A)), F);
3788 -- If the formal is Out or In_Out, do not resolve and expand the
3789 -- conversion, because it is subsequently expanded into explicit
3790 -- temporaries and assignments. However, the object of the
3791 -- conversion can be resolved. An exception is the case of tagged
3792 -- type conversion with a class-wide actual. In that case we want
3793 -- the tag check to occur and no temporary will be needed (no
3794 -- representation change can occur) and the parameter is passed by
3795 -- reference, so we go ahead and resolve the type conversion.
3796 -- Another exception is the case of reference to component or
3797 -- subcomponent of a bit-packed array, in which case we want to
3798 -- defer expansion to the point the in and out assignments are
3801 if Ekind (F) /= E_In_Parameter
3802 and then Nkind (A) = N_Type_Conversion
3803 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3805 if Ekind (F) = E_In_Out_Parameter
3806 and then Is_Array_Type (Etype (F))
3808 -- In a view conversion, the conversion must be legal in
3809 -- both directions, and thus both component types must be
3810 -- aliased, or neither (4.6 (8)).
3812 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3813 -- the privacy requirement should not apply to generic
3814 -- types, and should be checked in an instance. ARG query
3817 if Has_Aliased_Components (Etype (Expression (A))) /=
3818 Has_Aliased_Components (Etype (F))
3821 ("both component types in a view conversion must be"
3822 & " aliased, or neither", A);
3824 -- Comment here??? what set of cases???
3827 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3829 -- Check view conv between unrelated by ref array types
3831 if Is_By_Reference_Type (Etype (F))
3832 or else Is_By_Reference_Type (Etype (Expression (A)))
3835 ("view conversion between unrelated by reference "
3836 & "array types not allowed (\'A'I-00246)", A);
3838 -- In Ada 2005 mode, check view conversion component
3839 -- type cannot be private, tagged, or volatile. Note
3840 -- that we only apply this to source conversions. The
3841 -- generated code can contain conversions which are
3842 -- not subject to this test, and we cannot extract the
3843 -- component type in such cases since it is not present.
3845 elsif Comes_From_Source (A)
3846 and then Ada_Version >= Ada_2005
3849 Comp_Type : constant Entity_Id :=
3851 (Etype (Expression (A)));
3853 if (Is_Private_Type (Comp_Type)
3854 and then not Is_Generic_Type (Comp_Type))
3855 or else Is_Tagged_Type (Comp_Type)
3856 or else Is_Volatile (Comp_Type)
3859 ("component type of a view conversion cannot"
3860 & " be private, tagged, or volatile"
3869 -- Resolve expression if conversion is all OK
3871 if (Conversion_OK (A)
3872 or else Valid_Conversion (A, Etype (A), Expression (A)))
3873 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3875 Resolve (Expression (A));
3878 -- If the actual is a function call that returns a limited
3879 -- unconstrained object that needs finalization, create a
3880 -- transient scope for it, so that it can receive the proper
3881 -- finalization list.
3883 elsif Nkind (A) = N_Function_Call
3884 and then Is_Limited_Record (Etype (F))
3885 and then not Is_Constrained (Etype (F))
3886 and then Expander_Active
3887 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3889 Establish_Transient_Scope (A, Sec_Stack => False);
3890 Resolve (A, Etype (F));
3892 -- A small optimization: if one of the actuals is a concatenation
3893 -- create a block around a procedure call to recover stack space.
3894 -- This alleviates stack usage when several procedure calls in
3895 -- the same statement list use concatenation. We do not perform
3896 -- this wrapping for code statements, where the argument is a
3897 -- static string, and we want to preserve warnings involving
3898 -- sequences of such statements.
3900 elsif Nkind (A) = N_Op_Concat
3901 and then Nkind (N) = N_Procedure_Call_Statement
3902 and then Expander_Active
3904 not (Is_Intrinsic_Subprogram (Nam)
3905 and then Chars (Nam) = Name_Asm)
3906 and then not Static_Concatenation (A)
3908 Establish_Transient_Scope (A, Sec_Stack => False);
3909 Resolve (A, Etype (F));
3912 if Nkind (A) = N_Type_Conversion
3913 and then Is_Array_Type (Etype (F))
3914 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3916 (Is_Limited_Type (Etype (F))
3917 or else Is_Limited_Type (Etype (Expression (A))))
3920 ("conversion between unrelated limited array types "
3921 & "not allowed ('A'I-00246)", A);
3923 if Is_Limited_Type (Etype (F)) then
3924 Explain_Limited_Type (Etype (F), A);
3927 if Is_Limited_Type (Etype (Expression (A))) then
3928 Explain_Limited_Type (Etype (Expression (A)), A);
3932 -- (Ada 2005: AI-251): If the actual is an allocator whose
3933 -- directly designated type is a class-wide interface, we build
3934 -- an anonymous access type to use it as the type of the
3935 -- allocator. Later, when the subprogram call is expanded, if
3936 -- the interface has a secondary dispatch table the expander
3937 -- will add a type conversion to force the correct displacement
3940 if Nkind (A) = N_Allocator then
3942 DDT : constant Entity_Id :=
3943 Directly_Designated_Type (Base_Type (Etype (F)));
3945 New_Itype : Entity_Id;
3948 if Is_Class_Wide_Type (DDT)
3949 and then Is_Interface (DDT)
3951 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3952 Set_Etype (New_Itype, Etype (A));
3953 Set_Directly_Designated_Type
3954 (New_Itype, Directly_Designated_Type (Etype (A)));
3955 Set_Etype (A, New_Itype);
3958 -- Ada 2005, AI-162:If the actual is an allocator, the
3959 -- innermost enclosing statement is the master of the
3960 -- created object. This needs to be done with expansion
3961 -- enabled only, otherwise the transient scope will not
3962 -- be removed in the expansion of the wrapped construct.
3964 if (Is_Controlled (DDT) or else Has_Task (DDT))
3965 and then Expander_Active
3967 Establish_Transient_Scope (A, Sec_Stack => False);
3971 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3972 Check_Restriction (No_Access_Parameter_Allocators, A);
3976 -- (Ada 2005): The call may be to a primitive operation of a
3977 -- tagged synchronized type, declared outside of the type. In
3978 -- this case the controlling actual must be converted to its
3979 -- corresponding record type, which is the formal type. The
3980 -- actual may be a subtype, either because of a constraint or
3981 -- because it is a generic actual, so use base type to locate
3984 F_Typ := Base_Type (Etype (F));
3986 if Is_Tagged_Type (F_Typ)
3987 and then (Is_Concurrent_Type (F_Typ)
3988 or else Is_Concurrent_Record_Type (F_Typ))
3990 -- If the actual is overloaded, look for an interpretation
3991 -- that has a synchronized type.
3993 if not Is_Overloaded (A) then
3994 A_Typ := Base_Type (Etype (A));
3998 Index : Interp_Index;
4002 Get_First_Interp (A, Index, It);
4003 while Present (It.Typ) loop
4004 if Is_Concurrent_Type (It.Typ)
4005 or else Is_Concurrent_Record_Type (It.Typ)
4007 A_Typ := Base_Type (It.Typ);
4011 Get_Next_Interp (Index, It);
4017 Full_A_Typ : Entity_Id;
4020 if Present (Full_View (A_Typ)) then
4021 Full_A_Typ := Base_Type (Full_View (A_Typ));
4023 Full_A_Typ := A_Typ;
4026 -- Tagged synchronized type (case 1): the actual is a
4029 if Is_Concurrent_Type (A_Typ)
4030 and then Corresponding_Record_Type (A_Typ) = F_Typ
4033 Unchecked_Convert_To
4034 (Corresponding_Record_Type (A_Typ), A));
4035 Resolve (A, Etype (F));
4037 -- Tagged synchronized type (case 2): the formal is a
4040 elsif Ekind (Full_A_Typ) = E_Record_Type
4042 (Corresponding_Concurrent_Type (Full_A_Typ))
4043 and then Is_Concurrent_Type (F_Typ)
4044 and then Present (Corresponding_Record_Type (F_Typ))
4045 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4047 Resolve (A, Corresponding_Record_Type (F_Typ));
4052 Resolve (A, Etype (F));
4056 -- Not a synchronized operation
4059 Resolve (A, Etype (F));
4066 -- An actual cannot be an untagged formal incomplete type
4068 if Ekind (A_Typ) = E_Incomplete_Type
4069 and then not Is_Tagged_Type (A_Typ)
4070 and then Is_Generic_Type (A_Typ)
4073 ("invalid use of untagged formal incomplete type", A);
4076 if Comes_From_Source (Original_Node (N))
4077 and then Nkind_In (Original_Node (N), N_Function_Call,
4078 N_Procedure_Call_Statement)
4080 -- In formal mode, check that actual parameters matching
4081 -- formals of tagged types are objects (or ancestor type
4082 -- conversions of objects), not general expressions.
4084 if Is_Actual_Tagged_Parameter (A) then
4085 if Is_SPARK_05_Object_Reference (A) then
4088 elsif Nkind (A) = N_Type_Conversion then
4090 Operand : constant Node_Id := Expression (A);
4091 Operand_Typ : constant Entity_Id := Etype (Operand);
4092 Target_Typ : constant Entity_Id := A_Typ;
4095 if not Is_SPARK_05_Object_Reference (Operand) then
4096 Check_SPARK_05_Restriction
4097 ("object required", Operand);
4099 -- In formal mode, the only view conversions are those
4100 -- involving ancestor conversion of an extended type.
4103 (Is_Tagged_Type (Target_Typ)
4104 and then not Is_Class_Wide_Type (Target_Typ)
4105 and then Is_Tagged_Type (Operand_Typ)
4106 and then not Is_Class_Wide_Type (Operand_Typ)
4107 and then Is_Ancestor (Target_Typ, Operand_Typ))
4110 (F, E_Out_Parameter, E_In_Out_Parameter)
4112 Check_SPARK_05_Restriction
4113 ("ancestor conversion is the only permitted "
4114 & "view conversion", A);
4116 Check_SPARK_05_Restriction
4117 ("ancestor conversion required", A);
4126 Check_SPARK_05_Restriction ("object required", A);
4129 -- In formal mode, the only view conversions are those
4130 -- involving ancestor conversion of an extended type.
4132 elsif Nkind (A) = N_Type_Conversion
4133 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4135 Check_SPARK_05_Restriction
4136 ("ancestor conversion is the only permitted view "
4141 -- has warnings suppressed, then we reset Never_Set_In_Source for
4142 -- the calling entity. The reason for this is to catch cases like
4143 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4144 -- uses trickery to modify an IN parameter.
4146 if Ekind (F) = E_In_Parameter
4147 and then Is_Entity_Name (A)
4148 and then Present (Entity (A))
4149 and then Ekind (Entity (A)) = E_Variable
4150 and then Has_Warnings_Off (F_Typ)
4152 Set_Never_Set_In_Source (Entity (A), False);
4155 -- Perform error checks for IN and IN OUT parameters
4157 if Ekind (F) /= E_Out_Parameter then
4159 -- Check unset reference. For scalar parameters, it is clearly
4160 -- wrong to pass an uninitialized value as either an IN or
4161 -- IN-OUT parameter. For composites, it is also clearly an
4162 -- error to pass a completely uninitialized value as an IN
4163 -- parameter, but the case of IN OUT is trickier. We prefer
4164 -- not to give a warning here. For example, suppose there is
4165 -- a routine that sets some component of a record to False.
4166 -- It is perfectly reasonable to make this IN-OUT and allow
4167 -- either initialized or uninitialized records to be passed
4170 -- For partially initialized composite values, we also avoid
4171 -- warnings, since it is quite likely that we are passing a
4172 -- partially initialized value and only the initialized fields
4173 -- will in fact be read in the subprogram.
4175 if Is_Scalar_Type (A_Typ)
4176 or else (Ekind (F) = E_In_Parameter
4177 and then not Is_Partially_Initialized_Type (A_Typ))
4179 Check_Unset_Reference (A);
4182 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4183 -- actual to a nested call, since this constitutes a reading of
4184 -- the parameter, which is not allowed.
4186 if Ada_Version = Ada_83
4187 and then Is_Entity_Name (A)
4188 and then Ekind (Entity (A)) = E_Out_Parameter
4190 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4194 -- Case of OUT or IN OUT parameter
4196 if Ekind (F) /= E_In_Parameter then
4198 -- For an Out parameter, check for useless assignment. Note
4199 -- that we can't set Last_Assignment this early, because we may
4200 -- kill current values in Resolve_Call, and that call would
4201 -- clobber the Last_Assignment field.
4203 -- Note: call Warn_On_Useless_Assignment before doing the check
4204 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4205 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4206 -- reflects the last assignment, not this one.
4208 if Ekind (F) = E_Out_Parameter then
4209 if Warn_On_Modified_As_Out_Parameter (F)
4210 and then Is_Entity_Name (A)
4211 and then Present (Entity (A))
4212 and then Comes_From_Source (N)
4214 Warn_On_Useless_Assignment (Entity (A), A);
4218 -- Validate the form of the actual. Note that the call to
4219 -- Is_OK_Variable_For_Out_Formal generates the required
4220 -- reference in this case.
4222 -- A call to an initialization procedure for an aggregate
4223 -- component may initialize a nested component of a constant
4224 -- designated object. In this context the object is variable.
4226 if not Is_OK_Variable_For_Out_Formal (A)
4227 and then not Is_Init_Proc (Nam)
4229 Error_Msg_NE ("actual for& must be a variable", A, F);
4231 if Is_Subprogram (Current_Scope) then
4232 if Is_Invariant_Procedure (Current_Scope)
4233 or else Is_Partial_Invariant_Procedure (Current_Scope)
4236 ("function used in invariant cannot modify its "
4239 elsif Is_Predicate_Function (Current_Scope) then
4241 ("function used in predicate cannot modify its "
4247 -- What's the following about???
4249 if Is_Entity_Name (A) then
4250 Kill_Checks (Entity (A));
4256 if Etype (A) = Any_Type then
4257 Set_Etype (N, Any_Type);
4261 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4263 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4265 -- Apply predicate tests except in certain special cases. Note
4266 -- that it might be more consistent to apply these only when
4267 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4268 -- for the outbound predicate tests ??? In any case indicate
4269 -- the function being called, for better warnings if the call
4270 -- leads to an infinite recursion.
4272 if Predicate_Tests_On_Arguments (Nam) then
4273 Apply_Predicate_Check (A, F_Typ, Nam);
4276 -- Apply required constraint checks
4278 -- Gigi looks at the check flag and uses the appropriate types.
4279 -- For now since one flag is used there is an optimization
4280 -- which might not be done in the IN OUT case since Gigi does
4281 -- not do any analysis. More thought required about this ???
4283 -- In fact is this comment obsolete??? doesn't the expander now
4284 -- generate all these tests anyway???
4286 if Is_Scalar_Type (Etype (A)) then
4287 Apply_Scalar_Range_Check (A, F_Typ);
4289 elsif Is_Array_Type (Etype (A)) then
4290 Apply_Length_Check (A, F_Typ);
4292 elsif Is_Record_Type (F_Typ)
4293 and then Has_Discriminants (F_Typ)
4294 and then Is_Constrained (F_Typ)
4295 and then (not Is_Derived_Type (F_Typ)
4296 or else Comes_From_Source (Nam))
4298 Apply_Discriminant_Check (A, F_Typ);
4300 -- For view conversions of a discriminated object, apply
4301 -- check to object itself, the conversion alreay has the
4304 if Nkind (A) = N_Type_Conversion
4305 and then Is_Constrained (Etype (Expression (A)))
4307 Apply_Discriminant_Check (Expression (A), F_Typ);
4310 elsif Is_Access_Type (F_Typ)
4311 and then Is_Array_Type (Designated_Type (F_Typ))
4312 and then Is_Constrained (Designated_Type (F_Typ))
4314 Apply_Length_Check (A, F_Typ);
4316 elsif Is_Access_Type (F_Typ)
4317 and then Has_Discriminants (Designated_Type (F_Typ))
4318 and then Is_Constrained (Designated_Type (F_Typ))
4320 Apply_Discriminant_Check (A, F_Typ);
4323 Apply_Range_Check (A, F_Typ);
4326 -- Ada 2005 (AI-231): Note that the controlling parameter case
4327 -- already existed in Ada 95, which is partially checked
4328 -- elsewhere (see Checks), and we don't want the warning
4329 -- message to differ.
4331 if Is_Access_Type (F_Typ)
4332 and then Can_Never_Be_Null (F_Typ)
4333 and then Known_Null (A)
4335 if Is_Controlling_Formal (F) then
4336 Apply_Compile_Time_Constraint_Error
4338 Msg => "null value not allowed here??",
4339 Reason => CE_Access_Check_Failed);
4341 elsif Ada_Version >= Ada_2005 then
4342 Apply_Compile_Time_Constraint_Error
4344 Msg => "(Ada 2005) null not allowed in "
4345 & "null-excluding formal??",
4346 Reason => CE_Null_Not_Allowed);
4351 -- Checks for OUT parameters and IN OUT parameters
4353 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4355 -- If there is a type conversion, to make sure the return value
4356 -- meets the constraints of the variable before the conversion.
4358 if Nkind (A) = N_Type_Conversion then
4359 if Is_Scalar_Type (A_Typ) then
4360 Apply_Scalar_Range_Check
4361 (Expression (A), Etype (Expression (A)), A_Typ);
4364 (Expression (A), Etype (Expression (A)), A_Typ);
4367 -- If no conversion apply scalar range checks and length checks
4368 -- base on the subtype of the actual (NOT that of the formal).
4371 if Is_Scalar_Type (F_Typ) then
4372 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4373 elsif Is_Array_Type (F_Typ)
4374 and then Ekind (F) = E_Out_Parameter
4376 Apply_Length_Check (A, F_Typ);
4378 Apply_Range_Check (A, A_Typ, F_Typ);
4382 -- Note: we do not apply the predicate checks for the case of
4383 -- OUT and IN OUT parameters. They are instead applied in the
4384 -- Expand_Actuals routine in Exp_Ch6.
4387 -- An actual associated with an access parameter is implicitly
4388 -- converted to the anonymous access type of the formal and must
4389 -- satisfy the legality checks for access conversions.
4391 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4392 if not Valid_Conversion (A, F_Typ, A) then
4394 ("invalid implicit conversion for access parameter", A);
4397 -- If the actual is an access selected component of a variable,
4398 -- the call may modify its designated object. It is reasonable
4399 -- to treat this as a potential modification of the enclosing
4400 -- record, to prevent spurious warnings that it should be
4401 -- declared as a constant, because intuitively programmers
4402 -- regard the designated subcomponent as part of the record.
4404 if Nkind (A) = N_Selected_Component
4405 and then Is_Entity_Name (Prefix (A))
4406 and then not Is_Constant_Object (Entity (Prefix (A)))
4408 Note_Possible_Modification (A, Sure => False);
4412 -- Check bad case of atomic/volatile argument (RM C.6(12))
4414 if Is_By_Reference_Type (Etype (F))
4415 and then Comes_From_Source (N)
4417 if Is_Atomic_Object (A)
4418 and then not Is_Atomic (Etype (F))
4421 ("cannot pass atomic argument to non-atomic formal&",
4424 elsif Is_Volatile_Object (A)
4425 and then not Is_Volatile (Etype (F))
4428 ("cannot pass volatile argument to non-volatile formal&",
4433 -- Check that subprograms don't have improper controlling
4434 -- arguments (RM 3.9.2 (9)).
4436 -- A primitive operation may have an access parameter of an
4437 -- incomplete tagged type, but a dispatching call is illegal
4438 -- if the type is still incomplete.
4440 if Is_Controlling_Formal (F) then
4441 Set_Is_Controlling_Actual (A);
4443 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4445 Desig : constant Entity_Id := Designated_Type (Etype (F));
4447 if Ekind (Desig) = E_Incomplete_Type
4448 and then No (Full_View (Desig))
4449 and then No (Non_Limited_View (Desig))
4452 ("premature use of incomplete type& "
4453 & "in dispatching call", A, Desig);
4458 elsif Nkind (A) = N_Explicit_Dereference then
4459 Validate_Remote_Access_To_Class_Wide_Type (A);
4462 -- Apply legality rule 3.9.2 (9/1)
4464 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4465 and then not Is_Class_Wide_Type (F_Typ)
4466 and then not Is_Controlling_Formal (F)
4467 and then not In_Instance
4469 Error_Msg_N ("class-wide argument not allowed here!", A);
4471 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4472 Error_Msg_Node_2 := F_Typ;
4474 ("& is not a dispatching operation of &!", A, Nam);
4477 -- Apply the checks described in 3.10.2(27): if the context is a
4478 -- specific access-to-object, the actual cannot be class-wide.
4479 -- Use base type to exclude access_to_subprogram cases.
4481 elsif Is_Access_Type (A_Typ)
4482 and then Is_Access_Type (F_Typ)
4483 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4484 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4485 or else (Nkind (A) = N_Attribute_Reference
4487 Is_Class_Wide_Type (Etype (Prefix (A)))))
4488 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4489 and then not Is_Controlling_Formal (F)
4491 -- Disable these checks for call to imported C++ subprograms
4494 (Is_Entity_Name (Name (N))
4495 and then Is_Imported (Entity (Name (N)))
4496 and then Convention (Entity (Name (N))) = Convention_CPP)
4499 ("access to class-wide argument not allowed here!", A);
4501 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4502 Error_Msg_Node_2 := Designated_Type (F_Typ);
4504 ("& is not a dispatching operation of &!", A, Nam);
4508 Check_Aliased_Parameter;
4512 -- If it is a named association, treat the selector_name as a
4513 -- proper identifier, and mark the corresponding entity.
4515 if Nkind (Parent (A)) = N_Parameter_Association
4517 -- Ignore reference in SPARK mode, as it refers to an entity not
4518 -- in scope at the point of reference, so the reference should
4519 -- be ignored for computing effects of subprograms.
4521 and then not GNATprove_Mode
4523 -- If subprogram is overridden, use name of formal that
4526 if Present (Real_Subp) then
4527 Set_Entity (Selector_Name (Parent (A)), Real_F);
4528 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4531 Set_Entity (Selector_Name (Parent (A)), F);
4532 Generate_Reference (F, Selector_Name (Parent (A)));
4533 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4534 Generate_Reference (F_Typ, N, ' ');
4540 if Ekind (F) /= E_Out_Parameter then
4541 Check_Unset_Reference (A);
4544 -- The following checks are only relevant when SPARK_Mode is on as
4545 -- they are not standard Ada legality rule. Internally generated
4546 -- temporaries are ignored.
4548 if SPARK_Mode = On and then Comes_From_Source (A) then
4550 -- An effectively volatile object may act as an actual when the
4551 -- corresponding formal is of a non-scalar effectively volatile
4552 -- type (SPARK RM 7.1.3(11)).
4554 if not Is_Scalar_Type (Etype (F))
4555 and then Is_Effectively_Volatile (Etype (F))
4559 -- An effectively volatile object may act as an actual in a
4560 -- call to an instance of Unchecked_Conversion.
4561 -- (SPARK RM 7.1.3(11)).
4563 elsif Is_Unchecked_Conversion_Instance (Nam) then
4566 -- The actual denotes an object
4568 elsif Is_Effectively_Volatile_Object (A) then
4570 ("volatile object cannot act as actual in a call (SPARK "
4571 & "RM 7.1.3(11))", A);
4573 -- Otherwise the actual denotes an expression. Inspect the
4574 -- expression and flag each effectively volatile object with
4575 -- enabled property Async_Writers or Effective_Reads as illegal
4576 -- because it apprears within an interfering context. Note that
4577 -- this is usually done in Resolve_Entity_Name, but when the
4578 -- effectively volatile object appears as an actual in a call,
4579 -- the call must be resolved first.
4582 Flag_Effectively_Volatile_Objects (A);
4585 -- Detect an external variable with an enabled property that
4586 -- does not match the mode of the corresponding formal in a
4587 -- procedure call. Functions are not considered because they
4588 -- cannot have effectively volatile formal parameters in the
4591 if Ekind (Nam) = E_Procedure
4592 and then Ekind (F) = E_In_Parameter
4593 and then Is_Entity_Name (A)
4594 and then Present (Entity (A))
4595 and then Ekind (Entity (A)) = E_Variable
4599 if Async_Readers_Enabled (A_Id) then
4600 Property_Error (A, A_Id, Name_Async_Readers);
4601 elsif Effective_Reads_Enabled (A_Id) then
4602 Property_Error (A, A_Id, Name_Effective_Reads);
4603 elsif Effective_Writes_Enabled (A_Id) then
4604 Property_Error (A, A_Id, Name_Effective_Writes);
4609 -- A formal parameter of a specific tagged type whose related
4610 -- subprogram is subject to pragma Extensions_Visible with value
4611 -- "False" cannot act as an actual in a subprogram with value
4612 -- "True" (SPARK RM 6.1.7(3)).
4614 if Is_EVF_Expression (A)
4615 and then Extensions_Visible_Status (Nam) =
4616 Extensions_Visible_True
4619 ("formal parameter cannot act as actual parameter when "
4620 & "Extensions_Visible is False", A);
4622 ("\subprogram & has Extensions_Visible True", A, Nam);
4625 -- The actual parameter of a Ghost subprogram whose formal is of
4626 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4628 if Comes_From_Source (Nam)
4629 and then Is_Ghost_Entity (Nam)
4630 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4631 and then Is_Entity_Name (A)
4632 and then Present (Entity (A))
4633 and then not Is_Ghost_Entity (Entity (A))
4636 ("non-ghost variable & cannot appear as actual in call to "
4637 & "ghost procedure", A, Entity (A));
4639 if Ekind (F) = E_In_Out_Parameter then
4640 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4642 Error_Msg_N ("\corresponding formal has mode OUT", A);
4648 -- Case where actual is not present
4656 if Present (Real_Subp) then
4657 Next_Formal (Real_F);
4660 end Resolve_Actuals;
4662 -----------------------
4663 -- Resolve_Allocator --
4664 -----------------------
4666 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4667 Desig_T : constant Entity_Id := Designated_Type (Typ);
4668 E : constant Node_Id := Expression (N);
4670 Discrim : Entity_Id;
4673 Assoc : Node_Id := Empty;
4676 procedure Check_Allocator_Discrim_Accessibility
4677 (Disc_Exp : Node_Id;
4678 Alloc_Typ : Entity_Id);
4679 -- Check that accessibility level associated with an access discriminant
4680 -- initialized in an allocator by the expression Disc_Exp is not deeper
4681 -- than the level of the allocator type Alloc_Typ. An error message is
4682 -- issued if this condition is violated. Specialized checks are done for
4683 -- the cases of a constraint expression which is an access attribute or
4684 -- an access discriminant.
4686 function In_Dispatching_Context return Boolean;
4687 -- If the allocator is an actual in a call, it is allowed to be class-
4688 -- wide when the context is not because it is a controlling actual.
4690 -------------------------------------------
4691 -- Check_Allocator_Discrim_Accessibility --
4692 -------------------------------------------
4694 procedure Check_Allocator_Discrim_Accessibility
4695 (Disc_Exp : Node_Id;
4696 Alloc_Typ : Entity_Id)
4699 if Type_Access_Level (Etype (Disc_Exp)) >
4700 Deepest_Type_Access_Level (Alloc_Typ)
4703 ("operand type has deeper level than allocator type", Disc_Exp);
4705 -- When the expression is an Access attribute the level of the prefix
4706 -- object must not be deeper than that of the allocator's type.
4708 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4709 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4711 and then Object_Access_Level (Prefix (Disc_Exp)) >
4712 Deepest_Type_Access_Level (Alloc_Typ)
4715 ("prefix of attribute has deeper level than allocator type",
4718 -- When the expression is an access discriminant the check is against
4719 -- the level of the prefix object.
4721 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4722 and then Nkind (Disc_Exp) = N_Selected_Component
4723 and then Object_Access_Level (Prefix (Disc_Exp)) >
4724 Deepest_Type_Access_Level (Alloc_Typ)
4727 ("access discriminant has deeper level than allocator type",
4730 -- All other cases are legal
4735 end Check_Allocator_Discrim_Accessibility;
4737 ----------------------------
4738 -- In_Dispatching_Context --
4739 ----------------------------
4741 function In_Dispatching_Context return Boolean is
4742 Par : constant Node_Id := Parent (N);
4745 return Nkind (Par) in N_Subprogram_Call
4746 and then Is_Entity_Name (Name (Par))
4747 and then Is_Dispatching_Operation (Entity (Name (Par)));
4748 end In_Dispatching_Context;
4750 -- Start of processing for Resolve_Allocator
4753 -- Replace general access with specific type
4755 if Ekind (Etype (N)) = E_Allocator_Type then
4756 Set_Etype (N, Base_Type (Typ));
4759 if Is_Abstract_Type (Typ) then
4760 Error_Msg_N ("type of allocator cannot be abstract", N);
4763 -- For qualified expression, resolve the expression using the given
4764 -- subtype (nothing to do for type mark, subtype indication)
4766 if Nkind (E) = N_Qualified_Expression then
4767 if Is_Class_Wide_Type (Etype (E))
4768 and then not Is_Class_Wide_Type (Desig_T)
4769 and then not In_Dispatching_Context
4772 ("class-wide allocator not allowed for this access type", N);
4775 Resolve (Expression (E), Etype (E));
4776 Check_Non_Static_Context (Expression (E));
4777 Check_Unset_Reference (Expression (E));
4779 -- Allocators generated by the build-in-place expansion mechanism
4780 -- are explicitly marked as coming from source but do not need to be
4781 -- checked for limited initialization. To exclude this case, ensure
4782 -- that the parent of the allocator is a source node.
4784 if Is_Limited_Type (Etype (E))
4785 and then Comes_From_Source (N)
4786 and then Comes_From_Source (Parent (N))
4787 and then not In_Instance_Body
4789 if not OK_For_Limited_Init (Etype (E), Expression (E)) then
4790 if Nkind (Parent (N)) = N_Assignment_Statement then
4792 ("illegal expression for initialized allocator of a "
4793 & "limited type (RM 7.5 (2.7/2))", N);
4796 ("initialization not allowed for limited types", N);
4799 Explain_Limited_Type (Etype (E), N);
4803 -- A qualified expression requires an exact match of the type. Class-
4804 -- wide matching is not allowed.
4806 if (Is_Class_Wide_Type (Etype (Expression (E)))
4807 or else Is_Class_Wide_Type (Etype (E)))
4808 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4810 Wrong_Type (Expression (E), Etype (E));
4813 -- Calls to build-in-place functions are not currently supported in
4814 -- allocators for access types associated with a simple storage pool.
4815 -- Supporting such allocators may require passing additional implicit
4816 -- parameters to build-in-place functions (or a significant revision
4817 -- of the current b-i-p implementation to unify the handling for
4818 -- multiple kinds of storage pools). ???
4820 if Is_Limited_View (Desig_T)
4821 and then Nkind (Expression (E)) = N_Function_Call
4824 Pool : constant Entity_Id :=
4825 Associated_Storage_Pool (Root_Type (Typ));
4829 Present (Get_Rep_Pragma
4830 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4833 ("limited function calls not yet supported in simple "
4834 & "storage pool allocators", Expression (E));
4839 -- A special accessibility check is needed for allocators that
4840 -- constrain access discriminants. The level of the type of the
4841 -- expression used to constrain an access discriminant cannot be
4842 -- deeper than the type of the allocator (in contrast to access
4843 -- parameters, where the level of the actual can be arbitrary).
4845 -- We can't use Valid_Conversion to perform this check because in
4846 -- general the type of the allocator is unrelated to the type of
4847 -- the access discriminant.
4849 if Ekind (Typ) /= E_Anonymous_Access_Type
4850 or else Is_Local_Anonymous_Access (Typ)
4852 Subtyp := Entity (Subtype_Mark (E));
4854 Aggr := Original_Node (Expression (E));
4856 if Has_Discriminants (Subtyp)
4857 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4859 Discrim := First_Discriminant (Base_Type (Subtyp));
4861 -- Get the first component expression of the aggregate
4863 if Present (Expressions (Aggr)) then
4864 Disc_Exp := First (Expressions (Aggr));
4866 elsif Present (Component_Associations (Aggr)) then
4867 Assoc := First (Component_Associations (Aggr));
4869 if Present (Assoc) then
4870 Disc_Exp := Expression (Assoc);
4879 while Present (Discrim) and then Present (Disc_Exp) loop
4880 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4881 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4884 Next_Discriminant (Discrim);
4886 if Present (Discrim) then
4887 if Present (Assoc) then
4889 Disc_Exp := Expression (Assoc);
4891 elsif Present (Next (Disc_Exp)) then
4895 Assoc := First (Component_Associations (Aggr));
4897 if Present (Assoc) then
4898 Disc_Exp := Expression (Assoc);
4908 -- For a subtype mark or subtype indication, freeze the subtype
4911 Freeze_Expression (E);
4913 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4915 ("initialization required for access-to-constant allocator", N);
4918 -- A special accessibility check is needed for allocators that
4919 -- constrain access discriminants. The level of the type of the
4920 -- expression used to constrain an access discriminant cannot be
4921 -- deeper than the type of the allocator (in contrast to access
4922 -- parameters, where the level of the actual can be arbitrary).
4923 -- We can't use Valid_Conversion to perform this check because
4924 -- in general the type of the allocator is unrelated to the type
4925 -- of the access discriminant.
4927 if Nkind (Original_Node (E)) = N_Subtype_Indication
4928 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4929 or else Is_Local_Anonymous_Access (Typ))
4931 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4933 if Has_Discriminants (Subtyp) then
4934 Discrim := First_Discriminant (Base_Type (Subtyp));
4935 Constr := First (Constraints (Constraint (Original_Node (E))));
4936 while Present (Discrim) and then Present (Constr) loop
4937 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4938 if Nkind (Constr) = N_Discriminant_Association then
4939 Disc_Exp := Original_Node (Expression (Constr));
4941 Disc_Exp := Original_Node (Constr);
4944 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4947 Next_Discriminant (Discrim);
4954 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4955 -- check that the level of the type of the created object is not deeper
4956 -- than the level of the allocator's access type, since extensions can
4957 -- now occur at deeper levels than their ancestor types. This is a
4958 -- static accessibility level check; a run-time check is also needed in
4959 -- the case of an initialized allocator with a class-wide argument (see
4960 -- Expand_Allocator_Expression).
4962 if Ada_Version >= Ada_2005
4963 and then Is_Class_Wide_Type (Desig_T)
4966 Exp_Typ : Entity_Id;
4969 if Nkind (E) = N_Qualified_Expression then
4970 Exp_Typ := Etype (E);
4971 elsif Nkind (E) = N_Subtype_Indication then
4972 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4974 Exp_Typ := Entity (E);
4977 if Type_Access_Level (Exp_Typ) >
4978 Deepest_Type_Access_Level (Typ)
4980 if In_Instance_Body then
4981 Error_Msg_Warn := SPARK_Mode /= On;
4983 ("type in allocator has deeper level than "
4984 & "designated class-wide type<<", E);
4985 Error_Msg_N ("\Program_Error [<<", E);
4987 Make_Raise_Program_Error (Sloc (N),
4988 Reason => PE_Accessibility_Check_Failed));
4991 -- Do not apply Ada 2005 accessibility checks on a class-wide
4992 -- allocator if the type given in the allocator is a formal
4993 -- type. A run-time check will be performed in the instance.
4995 elsif not Is_Generic_Type (Exp_Typ) then
4996 Error_Msg_N ("type in allocator has deeper level than "
4997 & "designated class-wide type", E);
5003 -- Check for allocation from an empty storage pool
5005 if No_Pool_Assigned (Typ) then
5006 Error_Msg_N ("allocation from empty storage pool!", N);
5008 -- If the context is an unchecked conversion, as may happen within an
5009 -- inlined subprogram, the allocator is being resolved with its own
5010 -- anonymous type. In that case, if the target type has a specific
5011 -- storage pool, it must be inherited explicitly by the allocator type.
5013 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
5014 and then No (Associated_Storage_Pool (Typ))
5016 Set_Associated_Storage_Pool
5017 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
5020 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
5021 Check_Restriction (No_Anonymous_Allocators, N);
5024 -- Check that an allocator with task parts isn't for a nested access
5025 -- type when restriction No_Task_Hierarchy applies.
5027 if not Is_Library_Level_Entity (Base_Type (Typ))
5028 and then Has_Task (Base_Type (Desig_T))
5030 Check_Restriction (No_Task_Hierarchy, N);
5033 -- An illegal allocator may be rewritten as a raise Program_Error
5036 if Nkind (N) = N_Allocator then
5038 -- An anonymous access discriminant is the definition of a
5041 if Ekind (Typ) = E_Anonymous_Access_Type
5042 and then Nkind (Associated_Node_For_Itype (Typ)) =
5043 N_Discriminant_Specification
5046 Discr : constant Entity_Id :=
5047 Defining_Identifier (Associated_Node_For_Itype (Typ));
5050 Check_Restriction (No_Coextensions, N);
5052 -- Ada 2012 AI05-0052: If the designated type of the allocator
5053 -- is limited, then the allocator shall not be used to define
5054 -- the value of an access discriminant unless the discriminated
5055 -- type is immutably limited.
5057 if Ada_Version >= Ada_2012
5058 and then Is_Limited_Type (Desig_T)
5059 and then not Is_Limited_View (Scope (Discr))
5062 ("only immutably limited types can have anonymous "
5063 & "access discriminants designating a limited type", N);
5067 -- Avoid marking an allocator as a dynamic coextension if it is
5068 -- within a static construct.
5070 if not Is_Static_Coextension (N) then
5071 Set_Is_Dynamic_Coextension (N);
5074 -- Cleanup for potential static coextensions
5077 Set_Is_Dynamic_Coextension (N, False);
5078 Set_Is_Static_Coextension (N, False);
5082 -- Report a simple error: if the designated object is a local task,
5083 -- its body has not been seen yet, and its activation will fail an
5084 -- elaboration check.
5086 if Is_Task_Type (Desig_T)
5087 and then Scope (Base_Type (Desig_T)) = Current_Scope
5088 and then Is_Compilation_Unit (Current_Scope)
5089 and then Ekind (Current_Scope) = E_Package
5090 and then not In_Package_Body (Current_Scope)
5092 Error_Msg_Warn := SPARK_Mode /= On;
5093 Error_Msg_N ("cannot activate task before body seen<<", N);
5094 Error_Msg_N ("\Program_Error [<<", N);
5097 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5098 -- type with a task component on a subpool. This action must raise
5099 -- Program_Error at runtime.
5101 if Ada_Version >= Ada_2012
5102 and then Nkind (N) = N_Allocator
5103 and then Present (Subpool_Handle_Name (N))
5104 and then Has_Task (Desig_T)
5106 Error_Msg_Warn := SPARK_Mode /= On;
5107 Error_Msg_N ("cannot allocate task on subpool<<", N);
5108 Error_Msg_N ("\Program_Error [<<", N);
5111 Make_Raise_Program_Error (Sloc (N),
5112 Reason => PE_Explicit_Raise));
5115 end Resolve_Allocator;
5117 ---------------------------
5118 -- Resolve_Arithmetic_Op --
5119 ---------------------------
5121 -- Used for resolving all arithmetic operators except exponentiation
5123 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5124 L : constant Node_Id := Left_Opnd (N);
5125 R : constant Node_Id := Right_Opnd (N);
5126 TL : constant Entity_Id := Base_Type (Etype (L));
5127 TR : constant Entity_Id := Base_Type (Etype (R));
5131 B_Typ : constant Entity_Id := Base_Type (Typ);
5132 -- We do the resolution using the base type, because intermediate values
5133 -- in expressions always are of the base type, not a subtype of it.
5135 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5136 -- Returns True if N is in a context that expects "any real type"
5138 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5139 -- Return True iff given type is Integer or universal real/integer
5141 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5142 -- Choose type of integer literal in fixed-point operation to conform
5143 -- to available fixed-point type. T is the type of the other operand,
5144 -- which is needed to determine the expected type of N.
5146 procedure Set_Operand_Type (N : Node_Id);
5147 -- Set operand type to T if universal
5149 -------------------------------
5150 -- Expected_Type_Is_Any_Real --
5151 -------------------------------
5153 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5155 -- N is the expression after "delta" in a fixed_point_definition;
5158 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5159 N_Decimal_Fixed_Point_Definition,
5161 -- N is one of the bounds in a real_range_specification;
5164 N_Real_Range_Specification,
5166 -- N is the expression of a delta_constraint;
5169 N_Delta_Constraint);
5170 end Expected_Type_Is_Any_Real;
5172 -----------------------------
5173 -- Is_Integer_Or_Universal --
5174 -----------------------------
5176 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5178 Index : Interp_Index;
5182 if not Is_Overloaded (N) then
5184 return Base_Type (T) = Base_Type (Standard_Integer)
5185 or else T = Universal_Integer
5186 or else T = Universal_Real;
5188 Get_First_Interp (N, Index, It);
5189 while Present (It.Typ) loop
5190 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5191 or else It.Typ = Universal_Integer
5192 or else It.Typ = Universal_Real
5197 Get_Next_Interp (Index, It);
5202 end Is_Integer_Or_Universal;
5204 ----------------------------
5205 -- Set_Mixed_Mode_Operand --
5206 ----------------------------
5208 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5209 Index : Interp_Index;
5213 if Universal_Interpretation (N) = Universal_Integer then
5215 -- A universal integer literal is resolved as standard integer
5216 -- except in the case of a fixed-point result, where we leave it
5217 -- as universal (to be handled by Exp_Fixd later on)
5219 if Is_Fixed_Point_Type (T) then
5220 Resolve (N, Universal_Integer);
5222 Resolve (N, Standard_Integer);
5225 elsif Universal_Interpretation (N) = Universal_Real
5226 and then (T = Base_Type (Standard_Integer)
5227 or else T = Universal_Integer
5228 or else T = Universal_Real)
5230 -- A universal real can appear in a fixed-type context. We resolve
5231 -- the literal with that context, even though this might raise an
5232 -- exception prematurely (the other operand may be zero).
5236 elsif Etype (N) = Base_Type (Standard_Integer)
5237 and then T = Universal_Real
5238 and then Is_Overloaded (N)
5240 -- Integer arg in mixed-mode operation. Resolve with universal
5241 -- type, in case preference rule must be applied.
5243 Resolve (N, Universal_Integer);
5246 and then B_Typ /= Universal_Fixed
5248 -- Not a mixed-mode operation, resolve with context
5252 elsif Etype (N) = Any_Fixed then
5254 -- N may itself be a mixed-mode operation, so use context type
5258 elsif Is_Fixed_Point_Type (T)
5259 and then B_Typ = Universal_Fixed
5260 and then Is_Overloaded (N)
5262 -- Must be (fixed * fixed) operation, operand must have one
5263 -- compatible interpretation.
5265 Resolve (N, Any_Fixed);
5267 elsif Is_Fixed_Point_Type (B_Typ)
5268 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5269 and then Is_Overloaded (N)
5271 -- C * F(X) in a fixed context, where C is a real literal or a
5272 -- fixed-point expression. F must have either a fixed type
5273 -- interpretation or an integer interpretation, but not both.
5275 Get_First_Interp (N, Index, It);
5276 while Present (It.Typ) loop
5277 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5278 if Analyzed (N) then
5279 Error_Msg_N ("ambiguous operand in fixed operation", N);
5281 Resolve (N, Standard_Integer);
5284 elsif Is_Fixed_Point_Type (It.Typ) then
5285 if Analyzed (N) then
5286 Error_Msg_N ("ambiguous operand in fixed operation", N);
5288 Resolve (N, It.Typ);
5292 Get_Next_Interp (Index, It);
5295 -- Reanalyze the literal with the fixed type of the context. If
5296 -- context is Universal_Fixed, we are within a conversion, leave
5297 -- the literal as a universal real because there is no usable
5298 -- fixed type, and the target of the conversion plays no role in
5312 if B_Typ = Universal_Fixed
5313 and then Nkind (Op2) = N_Real_Literal
5315 T2 := Universal_Real;
5320 Set_Analyzed (Op2, False);
5327 end Set_Mixed_Mode_Operand;
5329 ----------------------
5330 -- Set_Operand_Type --
5331 ----------------------
5333 procedure Set_Operand_Type (N : Node_Id) is
5335 if Etype (N) = Universal_Integer
5336 or else Etype (N) = Universal_Real
5340 end Set_Operand_Type;
5342 -- Start of processing for Resolve_Arithmetic_Op
5345 if Comes_From_Source (N)
5346 and then Ekind (Entity (N)) = E_Function
5347 and then Is_Imported (Entity (N))
5348 and then Is_Intrinsic_Subprogram (Entity (N))
5350 Resolve_Intrinsic_Operator (N, Typ);
5353 -- Special-case for mixed-mode universal expressions or fixed point type
5354 -- operation: each argument is resolved separately. The same treatment
5355 -- is required if one of the operands of a fixed point operation is
5356 -- universal real, since in this case we don't do a conversion to a
5357 -- specific fixed-point type (instead the expander handles the case).
5359 -- Set the type of the node to its universal interpretation because
5360 -- legality checks on an exponentiation operand need the context.
5362 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5363 and then Present (Universal_Interpretation (L))
5364 and then Present (Universal_Interpretation (R))
5366 Set_Etype (N, B_Typ);
5367 Resolve (L, Universal_Interpretation (L));
5368 Resolve (R, Universal_Interpretation (R));
5370 elsif (B_Typ = Universal_Real
5371 or else Etype (N) = Universal_Fixed
5372 or else (Etype (N) = Any_Fixed
5373 and then Is_Fixed_Point_Type (B_Typ))
5374 or else (Is_Fixed_Point_Type (B_Typ)
5375 and then (Is_Integer_Or_Universal (L)
5377 Is_Integer_Or_Universal (R))))
5378 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5380 if TL = Universal_Integer or else TR = Universal_Integer then
5381 Check_For_Visible_Operator (N, B_Typ);
5384 -- If context is a fixed type and one operand is integer, the other
5385 -- is resolved with the type of the context.
5387 if Is_Fixed_Point_Type (B_Typ)
5388 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5389 or else TL = Universal_Integer)
5394 elsif Is_Fixed_Point_Type (B_Typ)
5395 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5396 or else TR = Universal_Integer)
5402 Set_Mixed_Mode_Operand (L, TR);
5403 Set_Mixed_Mode_Operand (R, TL);
5406 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5407 -- multiplying operators from being used when the expected type is
5408 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5409 -- some cases where the expected type is actually Any_Real;
5410 -- Expected_Type_Is_Any_Real takes care of that case.
5412 if Etype (N) = Universal_Fixed
5413 or else Etype (N) = Any_Fixed
5415 if B_Typ = Universal_Fixed
5416 and then not Expected_Type_Is_Any_Real (N)
5417 and then not Nkind_In (Parent (N), N_Type_Conversion,
5418 N_Unchecked_Type_Conversion)
5420 Error_Msg_N ("type cannot be determined from context!", N);
5421 Error_Msg_N ("\explicit conversion to result type required", N);
5423 Set_Etype (L, Any_Type);
5424 Set_Etype (R, Any_Type);
5427 if Ada_Version = Ada_83
5428 and then Etype (N) = Universal_Fixed
5430 Nkind_In (Parent (N), N_Type_Conversion,
5431 N_Unchecked_Type_Conversion)
5434 ("(Ada 83) fixed-point operation needs explicit "
5438 -- The expected type is "any real type" in contexts like
5440 -- type T is delta <universal_fixed-expression> ...
5442 -- in which case we need to set the type to Universal_Real
5443 -- so that static expression evaluation will work properly.
5445 if Expected_Type_Is_Any_Real (N) then
5446 Set_Etype (N, Universal_Real);
5448 Set_Etype (N, B_Typ);
5452 elsif Is_Fixed_Point_Type (B_Typ)
5453 and then (Is_Integer_Or_Universal (L)
5454 or else Nkind (L) = N_Real_Literal
5455 or else Nkind (R) = N_Real_Literal
5456 or else Is_Integer_Or_Universal (R))
5458 Set_Etype (N, B_Typ);
5460 elsif Etype (N) = Any_Fixed then
5462 -- If no previous errors, this is only possible if one operand is
5463 -- overloaded and the context is universal. Resolve as such.
5465 Set_Etype (N, B_Typ);
5469 if (TL = Universal_Integer or else TL = Universal_Real)
5471 (TR = Universal_Integer or else TR = Universal_Real)
5473 Check_For_Visible_Operator (N, B_Typ);
5476 -- If the context is Universal_Fixed and the operands are also
5477 -- universal fixed, this is an error, unless there is only one
5478 -- applicable fixed_point type (usually Duration).
5480 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5481 T := Unique_Fixed_Point_Type (N);
5483 if T = Any_Type then
5496 -- If one of the arguments was resolved to a non-universal type.
5497 -- label the result of the operation itself with the same type.
5498 -- Do the same for the universal argument, if any.
5500 T := Intersect_Types (L, R);
5501 Set_Etype (N, Base_Type (T));
5502 Set_Operand_Type (L);
5503 Set_Operand_Type (R);
5506 Generate_Operator_Reference (N, Typ);
5507 Analyze_Dimension (N);
5508 Eval_Arithmetic_Op (N);
5510 -- In SPARK, a multiplication or division with operands of fixed point
5511 -- types must be qualified or explicitly converted to identify the
5514 if (Is_Fixed_Point_Type (Etype (L))
5515 or else Is_Fixed_Point_Type (Etype (R)))
5516 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5518 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5520 Check_SPARK_05_Restriction
5521 ("operation should be qualified or explicitly converted", N);
5524 -- Set overflow and division checking bit
5526 if Nkind (N) in N_Op then
5527 if not Overflow_Checks_Suppressed (Etype (N)) then
5528 Enable_Overflow_Check (N);
5531 -- Give warning if explicit division by zero
5533 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5534 and then not Division_Checks_Suppressed (Etype (N))
5536 Rop := Right_Opnd (N);
5538 if Compile_Time_Known_Value (Rop)
5539 and then ((Is_Integer_Type (Etype (Rop))
5540 and then Expr_Value (Rop) = Uint_0)
5542 (Is_Real_Type (Etype (Rop))
5543 and then Expr_Value_R (Rop) = Ureal_0))
5545 -- Specialize the warning message according to the operation.
5546 -- When SPARK_Mode is On, force a warning instead of an error
5547 -- in that case, as this likely corresponds to deactivated
5548 -- code. The following warnings are for the case
5553 -- For division, we have two cases, for float division
5554 -- of an unconstrained float type, on a machine where
5555 -- Machine_Overflows is false, we don't get an exception
5556 -- at run-time, but rather an infinity or Nan. The Nan
5557 -- case is pretty obscure, so just warn about infinities.
5559 if Is_Floating_Point_Type (Typ)
5560 and then not Is_Constrained (Typ)
5561 and then not Machine_Overflows_On_Target
5564 ("float division by zero, may generate "
5565 & "'+'/'- infinity??", Right_Opnd (N));
5567 -- For all other cases, we get a Constraint_Error
5570 Apply_Compile_Time_Constraint_Error
5571 (N, "division by zero??", CE_Divide_By_Zero,
5572 Loc => Sloc (Right_Opnd (N)),
5573 Warn => SPARK_Mode = On);
5577 Apply_Compile_Time_Constraint_Error
5578 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5579 Loc => Sloc (Right_Opnd (N)),
5580 Warn => SPARK_Mode = On);
5583 Apply_Compile_Time_Constraint_Error
5584 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5585 Loc => Sloc (Right_Opnd (N)),
5586 Warn => SPARK_Mode = On);
5588 -- Division by zero can only happen with division, rem,
5589 -- and mod operations.
5592 raise Program_Error;
5595 -- In GNATprove mode, we enable the division check so that
5596 -- GNATprove will issue a message if it cannot be proved.
5598 if GNATprove_Mode then
5599 Activate_Division_Check (N);
5602 -- Otherwise just set the flag to check at run time
5605 Activate_Division_Check (N);
5609 -- If Restriction No_Implicit_Conditionals is active, then it is
5610 -- violated if either operand can be negative for mod, or for rem
5611 -- if both operands can be negative.
5613 if Restriction_Check_Required (No_Implicit_Conditionals)
5614 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5623 -- Set if corresponding operand might be negative
5627 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5628 LNeg := (not OK) or else Lo < 0;
5631 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5632 RNeg := (not OK) or else Lo < 0;
5634 -- Check if we will be generating conditionals. There are two
5635 -- cases where that can happen, first for REM, the only case
5636 -- is largest negative integer mod -1, where the division can
5637 -- overflow, but we still have to give the right result. The
5638 -- front end generates a test for this annoying case. Here we
5639 -- just test if both operands can be negative (that's what the
5640 -- expander does, so we match its logic here).
5642 -- The second case is mod where either operand can be negative.
5643 -- In this case, the back end has to generate additional tests.
5645 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5647 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5649 Check_Restriction (No_Implicit_Conditionals, N);
5655 Check_Unset_Reference (L);
5656 Check_Unset_Reference (R);
5657 end Resolve_Arithmetic_Op;
5663 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5664 function Same_Or_Aliased_Subprograms
5666 E : Entity_Id) return Boolean;
5667 -- Returns True if the subprogram entity S is the same as E or else
5668 -- S is an alias of E.
5670 ---------------------------------
5671 -- Same_Or_Aliased_Subprograms --
5672 ---------------------------------
5674 function Same_Or_Aliased_Subprograms
5676 E : Entity_Id) return Boolean
5678 Subp_Alias : constant Entity_Id := Alias (S);
5680 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5681 end Same_Or_Aliased_Subprograms;
5685 Loc : constant Source_Ptr := Sloc (N);
5686 Subp : constant Node_Id := Name (N);
5687 Body_Id : Entity_Id;
5697 -- Start of processing for Resolve_Call
5700 -- The context imposes a unique interpretation with type Typ on a
5701 -- procedure or function call. Find the entity of the subprogram that
5702 -- yields the expected type, and propagate the corresponding formal
5703 -- constraints on the actuals. The caller has established that an
5704 -- interpretation exists, and emitted an error if not unique.
5706 -- First deal with the case of a call to an access-to-subprogram,
5707 -- dereference made explicit in Analyze_Call.
5709 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5710 if not Is_Overloaded (Subp) then
5711 Nam := Etype (Subp);
5714 -- Find the interpretation whose type (a subprogram type) has a
5715 -- return type that is compatible with the context. Analysis of
5716 -- the node has established that one exists.
5720 Get_First_Interp (Subp, I, It);
5721 while Present (It.Typ) loop
5722 if Covers (Typ, Etype (It.Typ)) then
5727 Get_Next_Interp (I, It);
5731 raise Program_Error;
5735 -- If the prefix is not an entity, then resolve it
5737 if not Is_Entity_Name (Subp) then
5738 Resolve (Subp, Nam);
5741 -- For an indirect call, we always invalidate checks, since we do not
5742 -- know whether the subprogram is local or global. Yes we could do
5743 -- better here, e.g. by knowing that there are no local subprograms,
5744 -- but it does not seem worth the effort. Similarly, we kill all
5745 -- knowledge of current constant values.
5747 Kill_Current_Values;
5749 -- If this is a procedure call which is really an entry call, do
5750 -- the conversion of the procedure call to an entry call. Protected
5751 -- operations use the same circuitry because the name in the call
5752 -- can be an arbitrary expression with special resolution rules.
5754 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5755 or else (Is_Entity_Name (Subp)
5756 and then Ekind (Entity (Subp)) = E_Entry)
5758 Resolve_Entry_Call (N, Typ);
5759 Check_Elab_Call (N);
5761 -- Kill checks and constant values, as above for indirect case
5762 -- Who knows what happens when another task is activated?
5764 Kill_Current_Values;
5767 -- Normal subprogram call with name established in Resolve
5769 elsif not (Is_Type (Entity (Subp))) then
5770 Nam := Entity (Subp);
5771 Set_Entity_With_Checks (Subp, Nam);
5773 -- Otherwise we must have the case of an overloaded call
5776 pragma Assert (Is_Overloaded (Subp));
5778 -- Initialize Nam to prevent warning (we know it will be assigned
5779 -- in the loop below, but the compiler does not know that).
5783 Get_First_Interp (Subp, I, It);
5784 while Present (It.Typ) loop
5785 if Covers (Typ, It.Typ) then
5787 Set_Entity_With_Checks (Subp, Nam);
5791 Get_Next_Interp (I, It);
5795 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5796 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5797 and then Nkind (Subp) /= N_Explicit_Dereference
5798 and then Present (Parameter_Associations (N))
5800 -- The prefix is a parameterless function call that returns an access
5801 -- to subprogram. If parameters are present in the current call, add
5802 -- add an explicit dereference. We use the base type here because
5803 -- within an instance these may be subtypes.
5805 -- The dereference is added either in Analyze_Call or here. Should
5806 -- be consolidated ???
5808 Set_Is_Overloaded (Subp, False);
5809 Set_Etype (Subp, Etype (Nam));
5810 Insert_Explicit_Dereference (Subp);
5811 Nam := Designated_Type (Etype (Nam));
5812 Resolve (Subp, Nam);
5815 -- Check that a call to Current_Task does not occur in an entry body
5817 if Is_RTE (Nam, RE_Current_Task) then
5826 -- Exclude calls that occur within the default of a formal
5827 -- parameter of the entry, since those are evaluated outside
5830 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5832 if Nkind (P) = N_Entry_Body
5833 or else (Nkind (P) = N_Subprogram_Body
5834 and then Is_Entry_Barrier_Function (P))
5837 Error_Msg_Warn := SPARK_Mode /= On;
5839 ("& should not be used in entry body (RM C.7(17))<<",
5841 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5843 Make_Raise_Program_Error (Loc,
5844 Reason => PE_Current_Task_In_Entry_Body));
5845 Set_Etype (N, Rtype);
5852 -- Check that a procedure call does not occur in the context of the
5853 -- entry call statement of a conditional or timed entry call. Note that
5854 -- the case of a call to a subprogram renaming of an entry will also be
5855 -- rejected. The test for N not being an N_Entry_Call_Statement is
5856 -- defensive, covering the possibility that the processing of entry
5857 -- calls might reach this point due to later modifications of the code
5860 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5861 and then Nkind (N) /= N_Entry_Call_Statement
5862 and then Entry_Call_Statement (Parent (N)) = N
5864 if Ada_Version < Ada_2005 then
5865 Error_Msg_N ("entry call required in select statement", N);
5867 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5868 -- for a procedure_or_entry_call, the procedure_name or
5869 -- procedure_prefix of the procedure_call_statement shall denote
5870 -- an entry renamed by a procedure, or (a view of) a primitive
5871 -- subprogram of a limited interface whose first parameter is
5872 -- a controlling parameter.
5874 elsif Nkind (N) = N_Procedure_Call_Statement
5875 and then not Is_Renamed_Entry (Nam)
5876 and then not Is_Controlling_Limited_Procedure (Nam)
5879 ("entry call or dispatching primitive of interface required", N);
5883 -- If the SPARK_05 restriction is active, we are not allowed
5884 -- to have a call to a subprogram before we see its completion.
5886 if not Has_Completion (Nam)
5887 and then Restriction_Check_Required (SPARK_05)
5889 -- Don't flag strange internal calls
5891 and then Comes_From_Source (N)
5892 and then Comes_From_Source (Nam)
5894 -- Only flag calls in extended main source
5896 and then In_Extended_Main_Source_Unit (Nam)
5897 and then In_Extended_Main_Source_Unit (N)
5899 -- Exclude enumeration literals from this processing
5901 and then Ekind (Nam) /= E_Enumeration_Literal
5903 Check_SPARK_05_Restriction
5904 ("call to subprogram cannot appear before its body", N);
5907 -- Check that this is not a call to a protected procedure or entry from
5908 -- within a protected function.
5910 Check_Internal_Protected_Use (N, Nam);
5912 -- Freeze the subprogram name if not in a spec-expression. Note that
5913 -- we freeze procedure calls as well as function calls. Procedure calls
5914 -- are not frozen according to the rules (RM 13.14(14)) because it is
5915 -- impossible to have a procedure call to a non-frozen procedure in
5916 -- pure Ada, but in the code that we generate in the expander, this
5917 -- rule needs extending because we can generate procedure calls that
5920 -- In Ada 2012, expression functions may be called within pre/post
5921 -- conditions of subsequent functions or expression functions. Such
5922 -- calls do not freeze when they appear within generated bodies,
5923 -- (including the body of another expression function) which would
5924 -- place the freeze node in the wrong scope. An expression function
5925 -- is frozen in the usual fashion, by the appearance of a real body,
5926 -- or at the end of a declarative part.
5928 if Is_Entity_Name (Subp)
5929 and then not In_Spec_Expression
5930 and then not Is_Expression_Function_Or_Completion (Current_Scope)
5932 (not Is_Expression_Function_Or_Completion (Entity (Subp))
5933 or else Scope (Entity (Subp)) = Current_Scope)
5935 Freeze_Expression (Subp);
5938 -- For a predefined operator, the type of the result is the type imposed
5939 -- by context, except for a predefined operation on universal fixed.
5940 -- Otherwise The type of the call is the type returned by the subprogram
5943 if Is_Predefined_Op (Nam) then
5944 if Etype (N) /= Universal_Fixed then
5948 -- If the subprogram returns an array type, and the context requires the
5949 -- component type of that array type, the node is really an indexing of
5950 -- the parameterless call. Resolve as such. A pathological case occurs
5951 -- when the type of the component is an access to the array type. In
5952 -- this case the call is truly ambiguous.
5954 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5956 ((Is_Array_Type (Etype (Nam))
5957 and then Covers (Typ, Component_Type (Etype (Nam))))
5959 (Is_Access_Type (Etype (Nam))
5960 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5962 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5965 Index_Node : Node_Id;
5967 Ret_Type : constant Entity_Id := Etype (Nam);
5970 if Is_Access_Type (Ret_Type)
5971 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5974 ("cannot disambiguate function call and indexing", N);
5976 New_Subp := Relocate_Node (Subp);
5978 -- The called entity may be an explicit dereference, in which
5979 -- case there is no entity to set.
5981 if Nkind (New_Subp) /= N_Explicit_Dereference then
5982 Set_Entity (Subp, Nam);
5985 if (Is_Array_Type (Ret_Type)
5986 and then Component_Type (Ret_Type) /= Any_Type)
5988 (Is_Access_Type (Ret_Type)
5990 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5992 if Needs_No_Actuals (Nam) then
5994 -- Indexed call to a parameterless function
5997 Make_Indexed_Component (Loc,
5999 Make_Function_Call (Loc, Name => New_Subp),
6000 Expressions => Parameter_Associations (N));
6002 -- An Ada 2005 prefixed call to a primitive operation
6003 -- whose first parameter is the prefix. This prefix was
6004 -- prepended to the parameter list, which is actually a
6005 -- list of indexes. Remove the prefix in order to build
6006 -- the proper indexed component.
6009 Make_Indexed_Component (Loc,
6011 Make_Function_Call (Loc,
6013 Parameter_Associations =>
6015 (Remove_Head (Parameter_Associations (N)))),
6016 Expressions => Parameter_Associations (N));
6019 -- Preserve the parenthesis count of the node
6021 Set_Paren_Count (Index_Node, Paren_Count (N));
6023 -- Since we are correcting a node classification error made
6024 -- by the parser, we call Replace rather than Rewrite.
6026 Replace (N, Index_Node);
6028 Set_Etype (Prefix (N), Ret_Type);
6030 Resolve_Indexed_Component (N, Typ);
6031 Check_Elab_Call (Prefix (N));
6039 -- If the function returns the limited view of type, the call must
6040 -- appear in a context in which the non-limited view is available.
6041 -- As is done in Try_Object_Operation, use the available view to
6042 -- prevent back-end confusion.
6044 if From_Limited_With (Etype (Nam)) then
6045 Set_Etype (Nam, Available_View (Etype (Nam)));
6048 Set_Etype (N, Etype (Nam));
6051 -- In the case where the call is to an overloaded subprogram, Analyze
6052 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6053 -- such a case Normalize_Actuals needs to be called once more to order
6054 -- the actuals correctly. Otherwise the call will have the ordering
6055 -- given by the last overloaded subprogram whether this is the correct
6056 -- one being called or not.
6058 if Is_Overloaded (Subp) then
6059 Normalize_Actuals (N, Nam, False, Norm_OK);
6060 pragma Assert (Norm_OK);
6063 -- In any case, call is fully resolved now. Reset Overload flag, to
6064 -- prevent subsequent overload resolution if node is analyzed again
6066 Set_Is_Overloaded (Subp, False);
6067 Set_Is_Overloaded (N, False);
6069 -- A Ghost entity must appear in a specific context
6071 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6072 Check_Ghost_Context (Nam, N);
6075 -- If we are calling the current subprogram from immediately within its
6076 -- body, then that is the case where we can sometimes detect cases of
6077 -- infinite recursion statically. Do not try this in case restriction
6078 -- No_Recursion is in effect anyway, and do it only for source calls.
6080 if Comes_From_Source (N) then
6081 Scop := Current_Scope;
6083 -- Check violation of SPARK_05 restriction which does not permit
6084 -- a subprogram body to contain a call to the subprogram directly.
6086 if Restriction_Check_Required (SPARK_05)
6087 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6089 Check_SPARK_05_Restriction
6090 ("subprogram may not contain direct call to itself", N);
6093 -- Issue warning for possible infinite recursion in the absence
6094 -- of the No_Recursion restriction.
6096 if Same_Or_Aliased_Subprograms (Nam, Scop)
6097 and then not Restriction_Active (No_Recursion)
6098 and then Check_Infinite_Recursion (N)
6100 -- Here we detected and flagged an infinite recursion, so we do
6101 -- not need to test the case below for further warnings. Also we
6102 -- are all done if we now have a raise SE node.
6104 if Nkind (N) = N_Raise_Storage_Error then
6108 -- If call is to immediately containing subprogram, then check for
6109 -- the case of a possible run-time detectable infinite recursion.
6112 Scope_Loop : while Scop /= Standard_Standard loop
6113 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6115 -- Although in general case, recursion is not statically
6116 -- checkable, the case of calling an immediately containing
6117 -- subprogram is easy to catch.
6119 Check_Restriction (No_Recursion, N);
6121 -- If the recursive call is to a parameterless subprogram,
6122 -- then even if we can't statically detect infinite
6123 -- recursion, this is pretty suspicious, and we output a
6124 -- warning. Furthermore, we will try later to detect some
6125 -- cases here at run time by expanding checking code (see
6126 -- Detect_Infinite_Recursion in package Exp_Ch6).
6128 -- If the recursive call is within a handler, do not emit a
6129 -- warning, because this is a common idiom: loop until input
6130 -- is correct, catch illegal input in handler and restart.
6132 if No (First_Formal (Nam))
6133 and then Etype (Nam) = Standard_Void_Type
6134 and then not Error_Posted (N)
6135 and then Nkind (Parent (N)) /= N_Exception_Handler
6137 -- For the case of a procedure call. We give the message
6138 -- only if the call is the first statement in a sequence
6139 -- of statements, or if all previous statements are
6140 -- simple assignments. This is simply a heuristic to
6141 -- decrease false positives, without losing too many good
6142 -- warnings. The idea is that these previous statements
6143 -- may affect global variables the procedure depends on.
6144 -- We also exclude raise statements, that may arise from
6145 -- constraint checks and are probably unrelated to the
6146 -- intended control flow.
6148 if Nkind (N) = N_Procedure_Call_Statement
6149 and then Is_List_Member (N)
6155 while Present (P) loop
6156 if not Nkind_In (P, N_Assignment_Statement,
6157 N_Raise_Constraint_Error)
6167 -- Do not give warning if we are in a conditional context
6170 K : constant Node_Kind := Nkind (Parent (N));
6172 if (K = N_Loop_Statement
6173 and then Present (Iteration_Scheme (Parent (N))))
6174 or else K = N_If_Statement
6175 or else K = N_Elsif_Part
6176 or else K = N_Case_Statement_Alternative
6182 -- Here warning is to be issued
6184 Set_Has_Recursive_Call (Nam);
6185 Error_Msg_Warn := SPARK_Mode /= On;
6186 Error_Msg_N ("possible infinite recursion<<!", N);
6187 Error_Msg_N ("\Storage_Error ]<<!", N);
6193 Scop := Scope (Scop);
6194 end loop Scope_Loop;
6198 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6200 Check_Obsolescent_2005_Entity (Nam, Subp);
6202 -- If subprogram name is a predefined operator, it was given in
6203 -- functional notation. Replace call node with operator node, so
6204 -- that actuals can be resolved appropriately.
6206 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6207 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6210 elsif Present (Alias (Nam))
6211 and then Is_Predefined_Op (Alias (Nam))
6213 Resolve_Actuals (N, Nam);
6214 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6218 -- Create a transient scope if the resulting type requires it
6220 -- There are several notable exceptions:
6222 -- a) In init procs, the transient scope overhead is not needed, and is
6223 -- even incorrect when the call is a nested initialization call for a
6224 -- component whose expansion may generate adjust calls. However, if the
6225 -- call is some other procedure call within an initialization procedure
6226 -- (for example a call to Create_Task in the init_proc of the task
6227 -- run-time record) a transient scope must be created around this call.
6229 -- b) Enumeration literal pseudo-calls need no transient scope
6231 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6232 -- functions) do not use the secondary stack even though the return
6233 -- type may be unconstrained.
6235 -- d) Calls to a build-in-place function, since such functions may
6236 -- allocate their result directly in a target object, and cases where
6237 -- the result does get allocated in the secondary stack are checked for
6238 -- within the specialized Exp_Ch6 procedures for expanding those
6239 -- build-in-place calls.
6241 -- e) If the subprogram is marked Inline_Always, then even if it returns
6242 -- an unconstrained type the call does not require use of the secondary
6243 -- stack. However, inlining will only take place if the body to inline
6244 -- is already present. It may not be available if e.g. the subprogram is
6245 -- declared in a child instance.
6247 -- If this is an initialization call for a type whose construction
6248 -- uses the secondary stack, and it is not a nested call to initialize
6249 -- a component, we do need to create a transient scope for it. We
6250 -- check for this by traversing the type in Check_Initialization_Call.
6253 and then Has_Pragma_Inline (Nam)
6254 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6255 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6259 elsif Ekind (Nam) = E_Enumeration_Literal
6260 or else Is_Build_In_Place_Function (Nam)
6261 or else Is_Intrinsic_Subprogram (Nam)
6265 elsif Expander_Active
6266 and then Is_Type (Etype (Nam))
6267 and then Requires_Transient_Scope (Etype (Nam))
6269 (not Within_Init_Proc
6271 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6273 Establish_Transient_Scope (N, Sec_Stack => True);
6275 -- If the call appears within the bounds of a loop, it will
6276 -- be rewritten and reanalyzed, nothing left to do here.
6278 if Nkind (N) /= N_Function_Call then
6282 elsif Is_Init_Proc (Nam)
6283 and then not Within_Init_Proc
6285 Check_Initialization_Call (N, Nam);
6288 -- A protected function cannot be called within the definition of the
6289 -- enclosing protected type, unless it is part of a pre/postcondition
6290 -- on another protected operation. This may appear in the entry wrapper
6291 -- created for an entry with preconditions.
6293 if Is_Protected_Type (Scope (Nam))
6294 and then In_Open_Scopes (Scope (Nam))
6295 and then not Has_Completion (Scope (Nam))
6296 and then not In_Spec_Expression
6297 and then not Is_Entry_Wrapper (Current_Scope)
6300 ("& cannot be called before end of protected definition", N, Nam);
6303 -- Propagate interpretation to actuals, and add default expressions
6306 if Present (First_Formal (Nam)) then
6307 Resolve_Actuals (N, Nam);
6309 -- Overloaded literals are rewritten as function calls, for purpose of
6310 -- resolution. After resolution, we can replace the call with the
6313 elsif Ekind (Nam) = E_Enumeration_Literal then
6314 Copy_Node (Subp, N);
6315 Resolve_Entity_Name (N, Typ);
6317 -- Avoid validation, since it is a static function call
6319 Generate_Reference (Nam, Subp);
6323 -- If the subprogram is not global, then kill all saved values and
6324 -- checks. This is a bit conservative, since in many cases we could do
6325 -- better, but it is not worth the effort. Similarly, we kill constant
6326 -- values. However we do not need to do this for internal entities
6327 -- (unless they are inherited user-defined subprograms), since they
6328 -- are not in the business of molesting local values.
6330 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6331 -- kill all checks and values for calls to global subprograms. This
6332 -- takes care of the case where an access to a local subprogram is
6333 -- taken, and could be passed directly or indirectly and then called
6334 -- from almost any context.
6336 -- Note: we do not do this step till after resolving the actuals. That
6337 -- way we still take advantage of the current value information while
6338 -- scanning the actuals.
6340 -- We suppress killing values if we are processing the nodes associated
6341 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6342 -- type kills all the values as part of analyzing the code that
6343 -- initializes the dispatch tables.
6345 if Inside_Freezing_Actions = 0
6346 and then (not Is_Library_Level_Entity (Nam)
6347 or else Suppress_Value_Tracking_On_Call
6348 (Nearest_Dynamic_Scope (Current_Scope)))
6349 and then (Comes_From_Source (Nam)
6350 or else (Present (Alias (Nam))
6351 and then Comes_From_Source (Alias (Nam))))
6353 Kill_Current_Values;
6356 -- If we are warning about unread OUT parameters, this is the place to
6357 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6358 -- after the above call to Kill_Current_Values (since that call clears
6359 -- the Last_Assignment field of all local variables).
6361 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6362 and then Comes_From_Source (N)
6363 and then In_Extended_Main_Source_Unit (N)
6370 F := First_Formal (Nam);
6371 A := First_Actual (N);
6372 while Present (F) and then Present (A) loop
6373 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6374 and then Warn_On_Modified_As_Out_Parameter (F)
6375 and then Is_Entity_Name (A)
6376 and then Present (Entity (A))
6377 and then Comes_From_Source (N)
6378 and then Safe_To_Capture_Value (N, Entity (A))
6380 Set_Last_Assignment (Entity (A), A);
6389 -- If the subprogram is a primitive operation, check whether or not
6390 -- it is a correct dispatching call.
6392 if Is_Overloadable (Nam)
6393 and then Is_Dispatching_Operation (Nam)
6395 Check_Dispatching_Call (N);
6397 elsif Ekind (Nam) /= E_Subprogram_Type
6398 and then Is_Abstract_Subprogram (Nam)
6399 and then not In_Instance
6401 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6404 -- If this is a dispatching call, generate the appropriate reference,
6405 -- for better source navigation in GPS.
6407 if Is_Overloadable (Nam)
6408 and then Present (Controlling_Argument (N))
6410 Generate_Reference (Nam, Subp, 'R');
6412 -- Normal case, not a dispatching call: generate a call reference
6415 Generate_Reference (Nam, Subp, 's');
6418 if Is_Intrinsic_Subprogram (Nam) then
6419 Check_Intrinsic_Call (N);
6422 -- Check for violation of restriction No_Specific_Termination_Handlers
6423 -- and warn on a potentially blocking call to Abort_Task.
6425 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6426 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6428 Is_RTE (Nam, RE_Specific_Handler))
6430 Check_Restriction (No_Specific_Termination_Handlers, N);
6432 elsif Is_RTE (Nam, RE_Abort_Task) then
6433 Check_Potentially_Blocking_Operation (N);
6436 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6437 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6438 -- need to check the second argument to determine whether it is an
6439 -- absolute or relative timing event.
6441 if Restriction_Check_Required (No_Relative_Delay)
6442 and then Is_RTE (Nam, RE_Set_Handler)
6443 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6445 Check_Restriction (No_Relative_Delay, N);
6448 -- Issue an error for a call to an eliminated subprogram. This routine
6449 -- will not perform the check if the call appears within a default
6452 Check_For_Eliminated_Subprogram (Subp, Nam);
6454 -- In formal mode, the primitive operations of a tagged type or type
6455 -- extension do not include functions that return the tagged type.
6457 if Nkind (N) = N_Function_Call
6458 and then Is_Tagged_Type (Etype (N))
6459 and then Is_Entity_Name (Name (N))
6460 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6462 Check_SPARK_05_Restriction ("function not inherited", N);
6465 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6466 -- class-wide and the call dispatches on result in a context that does
6467 -- not provide a tag, the call raises Program_Error.
6469 if Nkind (N) = N_Function_Call
6470 and then In_Instance
6471 and then Is_Generic_Actual_Type (Typ)
6472 and then Is_Class_Wide_Type (Typ)
6473 and then Has_Controlling_Result (Nam)
6474 and then Nkind (Parent (N)) = N_Object_Declaration
6476 -- Verify that none of the formals are controlling
6479 Call_OK : Boolean := False;
6483 F := First_Formal (Nam);
6484 while Present (F) loop
6485 if Is_Controlling_Formal (F) then
6494 Error_Msg_Warn := SPARK_Mode /= On;
6495 Error_Msg_N ("!cannot determine tag of result<<", N);
6496 Error_Msg_N ("\Program_Error [<<!", N);
6498 Make_Raise_Program_Error (Sloc (N),
6499 Reason => PE_Explicit_Raise));
6504 -- Check for calling a function with OUT or IN OUT parameter when the
6505 -- calling context (us right now) is not Ada 2012, so does not allow
6506 -- OUT or IN OUT parameters in function calls. Functions declared in
6507 -- a predefined unit are OK, as they may be called indirectly from a
6508 -- user-declared instantiation.
6510 if Ada_Version < Ada_2012
6511 and then Ekind (Nam) = E_Function
6512 and then Has_Out_Or_In_Out_Parameter (Nam)
6513 and then not In_Predefined_Unit (Nam)
6515 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6516 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6519 -- Check the dimensions of the actuals in the call. For function calls,
6520 -- propagate the dimensions from the returned type to N.
6522 Analyze_Dimension_Call (N, Nam);
6524 -- All done, evaluate call and deal with elaboration issues
6527 Check_Elab_Call (N);
6529 -- In GNATprove mode, expansion is disabled, but we want to inline some
6530 -- subprograms to facilitate formal verification. Indirect calls through
6531 -- a subprogram type or within a generic cannot be inlined. Inlining is
6532 -- performed only for calls subject to SPARK_Mode on.
6535 and then SPARK_Mode = On
6536 and then Is_Overloadable (Nam)
6537 and then not Inside_A_Generic
6539 Nam_UA := Ultimate_Alias (Nam);
6540 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6542 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6543 Body_Id := Corresponding_Body (Nam_Decl);
6545 -- Nothing to do if the subprogram is not eligible for inlining in
6548 if not Is_Inlined_Always (Nam_UA)
6549 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6553 -- Calls cannot be inlined inside assertions, as GNATprove treats
6554 -- assertions as logic expressions.
6556 elsif In_Assertion_Expr /= 0 then
6558 ("cannot inline & (in assertion expression)?", N, Nam_UA);
6560 -- Calls cannot be inlined inside default expressions
6562 elsif In_Default_Expr then
6564 ("cannot inline & (in default expression)?", N, Nam_UA);
6566 -- Inlining should not be performed during pre-analysis
6568 elsif Full_Analysis then
6570 -- With the one-pass inlining technique, a call cannot be
6571 -- inlined if the corresponding body has not been seen yet.
6573 if No (Body_Id) then
6575 ("cannot inline & (body not seen yet)?", N, Nam_UA);
6577 -- Nothing to do if there is no body to inline, indicating that
6578 -- the subprogram is not suitable for inlining in GNATprove
6581 elsif No (Body_To_Inline (Nam_Decl)) then
6584 -- Do not inline calls inside expression functions, as this
6585 -- would prevent interpreting them as logical formulas in
6588 elsif Present (Current_Subprogram)
6590 Is_Expression_Function_Or_Completion (Current_Subprogram)
6593 ("cannot inline & (inside expression function)?",
6596 -- Calls cannot be inlined inside potentially unevaluated
6597 -- expressions, as this would create complex actions inside
6598 -- expressions, that are not handled by GNATprove.
6600 elsif Is_Potentially_Unevaluated (N) then
6602 ("cannot inline & (in potentially unevaluated context)?",
6605 -- Otherwise, inline the call
6608 Expand_Inlined_Call (N, Nam_UA, Nam);
6614 Warn_On_Overlapping_Actuals (Nam, N);
6617 -----------------------------
6618 -- Resolve_Case_Expression --
6619 -----------------------------
6621 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6624 Alt_Typ : Entity_Id;
6628 Alt := First (Alternatives (N));
6629 while Present (Alt) loop
6630 Alt_Expr := Expression (Alt);
6631 Resolve (Alt_Expr, Typ);
6632 Alt_Typ := Etype (Alt_Expr);
6634 -- When the expression is of a scalar subtype different from the
6635 -- result subtype, then insert a conversion to ensure the generation
6636 -- of a constraint check.
6638 if Is_Scalar_Type (Alt_Typ) and then Alt_Typ /= Typ then
6639 Rewrite (Alt_Expr, Convert_To (Typ, Alt_Expr));
6640 Analyze_And_Resolve (Alt_Expr, Typ);
6646 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6647 -- dynamically tagged must be known statically.
6649 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
6650 Alt := First (Alternatives (N));
6651 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
6653 while Present (Alt) loop
6654 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
6656 ("all or none of the dependent expressions can be "
6657 & "dynamically tagged", N);
6665 Eval_Case_Expression (N);
6666 end Resolve_Case_Expression;
6668 -------------------------------
6669 -- Resolve_Character_Literal --
6670 -------------------------------
6672 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6673 B_Typ : constant Entity_Id := Base_Type (Typ);
6677 -- Verify that the character does belong to the type of the context
6679 Set_Etype (N, B_Typ);
6680 Eval_Character_Literal (N);
6682 -- Wide_Wide_Character literals must always be defined, since the set
6683 -- of wide wide character literals is complete, i.e. if a character
6684 -- literal is accepted by the parser, then it is OK for wide wide
6685 -- character (out of range character literals are rejected).
6687 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6690 -- Always accept character literal for type Any_Character, which
6691 -- occurs in error situations and in comparisons of literals, both
6692 -- of which should accept all literals.
6694 elsif B_Typ = Any_Character then
6697 -- For Standard.Character or a type derived from it, check that the
6698 -- literal is in range.
6700 elsif Root_Type (B_Typ) = Standard_Character then
6701 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6705 -- For Standard.Wide_Character or a type derived from it, check that the
6706 -- literal is in range.
6708 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6709 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6713 -- For Standard.Wide_Wide_Character or a type derived from it, we
6714 -- know the literal is in range, since the parser checked.
6716 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6719 -- If the entity is already set, this has already been resolved in a
6720 -- generic context, or comes from expansion. Nothing else to do.
6722 elsif Present (Entity (N)) then
6725 -- Otherwise we have a user defined character type, and we can use the
6726 -- standard visibility mechanisms to locate the referenced entity.
6729 C := Current_Entity (N);
6730 while Present (C) loop
6731 if Etype (C) = B_Typ then
6732 Set_Entity_With_Checks (N, C);
6733 Generate_Reference (C, N);
6741 -- If we fall through, then the literal does not match any of the
6742 -- entries of the enumeration type. This isn't just a constraint error
6743 -- situation, it is an illegality (see RM 4.2).
6746 ("character not defined for }", N, First_Subtype (B_Typ));
6747 end Resolve_Character_Literal;
6749 ---------------------------
6750 -- Resolve_Comparison_Op --
6751 ---------------------------
6753 -- Context requires a boolean type, and plays no role in resolution.
6754 -- Processing identical to that for equality operators. The result type is
6755 -- the base type, which matters when pathological subtypes of booleans with
6756 -- limited ranges are used.
6758 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6759 L : constant Node_Id := Left_Opnd (N);
6760 R : constant Node_Id := Right_Opnd (N);
6764 -- If this is an intrinsic operation which is not predefined, use the
6765 -- types of its declared arguments to resolve the possibly overloaded
6766 -- operands. Otherwise the operands are unambiguous and specify the
6769 if Scope (Entity (N)) /= Standard_Standard then
6770 T := Etype (First_Entity (Entity (N)));
6773 T := Find_Unique_Type (L, R);
6775 if T = Any_Fixed then
6776 T := Unique_Fixed_Point_Type (L);
6780 Set_Etype (N, Base_Type (Typ));
6781 Generate_Reference (T, N, ' ');
6783 -- Skip remaining processing if already set to Any_Type
6785 if T = Any_Type then
6789 -- Deal with other error cases
6791 if T = Any_String or else
6792 T = Any_Composite or else
6795 if T = Any_Character then
6796 Ambiguous_Character (L);
6798 Error_Msg_N ("ambiguous operands for comparison", N);
6801 Set_Etype (N, Any_Type);
6805 -- Resolve the operands if types OK
6809 Check_Unset_Reference (L);
6810 Check_Unset_Reference (R);
6811 Generate_Operator_Reference (N, T);
6812 Check_Low_Bound_Tested (N);
6814 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6815 -- types or array types except String.
6817 if Is_Boolean_Type (T) then
6818 Check_SPARK_05_Restriction
6819 ("comparison is not defined on Boolean type", N);
6821 elsif Is_Array_Type (T)
6822 and then Base_Type (T) /= Standard_String
6824 Check_SPARK_05_Restriction
6825 ("comparison is not defined on array types other than String", N);
6828 -- Check comparison on unordered enumeration
6830 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6831 Error_Msg_Sloc := Sloc (Etype (L));
6833 ("comparison on unordered enumeration type& declared#?U?",
6837 -- Evaluate the relation (note we do this after the above check since
6838 -- this Eval call may change N to True/False.
6840 Analyze_Dimension (N);
6841 Eval_Relational_Op (N);
6842 end Resolve_Comparison_Op;
6844 -----------------------------------------
6845 -- Resolve_Discrete_Subtype_Indication --
6846 -----------------------------------------
6848 procedure Resolve_Discrete_Subtype_Indication
6856 Analyze (Subtype_Mark (N));
6857 S := Entity (Subtype_Mark (N));
6859 if Nkind (Constraint (N)) /= N_Range_Constraint then
6860 Error_Msg_N ("expect range constraint for discrete type", N);
6861 Set_Etype (N, Any_Type);
6864 R := Range_Expression (Constraint (N));
6872 if Base_Type (S) /= Base_Type (Typ) then
6874 ("expect subtype of }", N, First_Subtype (Typ));
6876 -- Rewrite the constraint as a range of Typ
6877 -- to allow compilation to proceed further.
6880 Rewrite (Low_Bound (R),
6881 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6882 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6883 Attribute_Name => Name_First));
6884 Rewrite (High_Bound (R),
6885 Make_Attribute_Reference (Sloc (High_Bound (R)),
6886 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6887 Attribute_Name => Name_First));
6891 Set_Etype (N, Etype (R));
6893 -- Additionally, we must check that the bounds are compatible
6894 -- with the given subtype, which might be different from the
6895 -- type of the context.
6897 Apply_Range_Check (R, S);
6899 -- ??? If the above check statically detects a Constraint_Error
6900 -- it replaces the offending bound(s) of the range R with a
6901 -- Constraint_Error node. When the itype which uses these bounds
6902 -- is frozen the resulting call to Duplicate_Subexpr generates
6903 -- a new temporary for the bounds.
6905 -- Unfortunately there are other itypes that are also made depend
6906 -- on these bounds, so when Duplicate_Subexpr is called they get
6907 -- a forward reference to the newly created temporaries and Gigi
6908 -- aborts on such forward references. This is probably sign of a
6909 -- more fundamental problem somewhere else in either the order of
6910 -- itype freezing or the way certain itypes are constructed.
6912 -- To get around this problem we call Remove_Side_Effects right
6913 -- away if either bounds of R are a Constraint_Error.
6916 L : constant Node_Id := Low_Bound (R);
6917 H : constant Node_Id := High_Bound (R);
6920 if Nkind (L) = N_Raise_Constraint_Error then
6921 Remove_Side_Effects (L);
6924 if Nkind (H) = N_Raise_Constraint_Error then
6925 Remove_Side_Effects (H);
6929 Check_Unset_Reference (Low_Bound (R));
6930 Check_Unset_Reference (High_Bound (R));
6933 end Resolve_Discrete_Subtype_Indication;
6935 -------------------------
6936 -- Resolve_Entity_Name --
6937 -------------------------
6939 -- Used to resolve identifiers and expanded names
6941 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6942 function Is_Assignment_Or_Object_Expression
6944 Expr : Node_Id) return Boolean;
6945 -- Determine whether node Context denotes an assignment statement or an
6946 -- object declaration whose expression is node Expr.
6948 ----------------------------------------
6949 -- Is_Assignment_Or_Object_Expression --
6950 ----------------------------------------
6952 function Is_Assignment_Or_Object_Expression
6954 Expr : Node_Id) return Boolean
6957 if Nkind_In (Context, N_Assignment_Statement,
6958 N_Object_Declaration)
6959 and then Expression (Context) = Expr
6963 -- Check whether a construct that yields a name is the expression of
6964 -- an assignment statement or an object declaration.
6966 elsif (Nkind_In (Context, N_Attribute_Reference,
6967 N_Explicit_Dereference,
6968 N_Indexed_Component,
6969 N_Selected_Component,
6971 and then Prefix (Context) = Expr)
6973 (Nkind_In (Context, N_Type_Conversion,
6974 N_Unchecked_Type_Conversion)
6975 and then Expression (Context) = Expr)
6978 Is_Assignment_Or_Object_Expression
6979 (Context => Parent (Context),
6982 -- Otherwise the context is not an assignment statement or an object
6988 end Is_Assignment_Or_Object_Expression;
6992 E : constant Entity_Id := Entity (N);
6995 -- Start of processing for Resolve_Entity_Name
6998 -- If garbage from errors, set to Any_Type and return
7000 if No (E) and then Total_Errors_Detected /= 0 then
7001 Set_Etype (N, Any_Type);
7005 -- Replace named numbers by corresponding literals. Note that this is
7006 -- the one case where Resolve_Entity_Name must reset the Etype, since
7007 -- it is currently marked as universal.
7009 if Ekind (E) = E_Named_Integer then
7011 Eval_Named_Integer (N);
7013 elsif Ekind (E) = E_Named_Real then
7015 Eval_Named_Real (N);
7017 -- For enumeration literals, we need to make sure that a proper style
7018 -- check is done, since such literals are overloaded, and thus we did
7019 -- not do a style check during the first phase of analysis.
7021 elsif Ekind (E) = E_Enumeration_Literal then
7022 Set_Entity_With_Checks (N, E);
7023 Eval_Entity_Name (N);
7025 -- Case of (sub)type name appearing in a context where an expression
7026 -- is expected. This is legal if occurrence is a current instance.
7027 -- See RM 8.6 (17/3).
7029 elsif Is_Type (E) then
7030 if Is_Current_Instance (N) then
7033 -- Any other use is an error
7037 ("invalid use of subtype mark in expression or call", N);
7040 -- Check discriminant use if entity is discriminant in current scope,
7041 -- i.e. discriminant of record or concurrent type currently being
7042 -- analyzed. Uses in corresponding body are unrestricted.
7044 elsif Ekind (E) = E_Discriminant
7045 and then Scope (E) = Current_Scope
7046 and then not Has_Completion (Current_Scope)
7048 Check_Discriminant_Use (N);
7050 -- A parameterless generic function cannot appear in a context that
7051 -- requires resolution.
7053 elsif Ekind (E) = E_Generic_Function then
7054 Error_Msg_N ("illegal use of generic function", N);
7056 -- In Ada 83 an OUT parameter cannot be read
7058 elsif Ekind (E) = E_Out_Parameter
7059 and then (Nkind (Parent (N)) in N_Op
7060 or else Nkind (Parent (N)) = N_Explicit_Dereference
7061 or else Is_Assignment_Or_Object_Expression
7062 (Context => Parent (N),
7065 if Ada_Version = Ada_83 then
7066 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7069 -- In all other cases, just do the possible static evaluation
7072 -- A deferred constant that appears in an expression must have a
7073 -- completion, unless it has been removed by in-place expansion of
7074 -- an aggregate. A constant that is a renaming does not need
7077 if Ekind (E) = E_Constant
7078 and then Comes_From_Source (E)
7079 and then No (Constant_Value (E))
7080 and then Is_Frozen (Etype (E))
7081 and then not In_Spec_Expression
7082 and then not Is_Imported (E)
7083 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7085 if No_Initialization (Parent (E))
7086 or else (Present (Full_View (E))
7087 and then No_Initialization (Parent (Full_View (E))))
7092 ("deferred constant is frozen before completion", N);
7096 Eval_Entity_Name (N);
7101 -- When the entity appears in a parameter association, retrieve the
7102 -- related subprogram call.
7104 if Nkind (Par) = N_Parameter_Association then
7105 Par := Parent (Par);
7108 if Comes_From_Source (N) then
7110 -- The following checks are only relevant when SPARK_Mode is on as
7111 -- they are not standard Ada legality rules.
7113 if SPARK_Mode = On then
7115 -- An effectively volatile object subject to enabled properties
7116 -- Async_Writers or Effective_Reads must appear in non-interfering
7117 -- context (SPARK RM 7.1.3(12)).
7120 and then Is_Effectively_Volatile (E)
7121 and then (Async_Writers_Enabled (E)
7122 or else Effective_Reads_Enabled (E))
7123 and then not Is_OK_Volatile_Context (Par, N)
7126 ("volatile object cannot appear in this context "
7127 & "(SPARK RM 7.1.3(12))", N);
7130 -- Check for possible elaboration issues with respect to reads of
7131 -- variables. The act of renaming the variable is not considered a
7132 -- read as it simply establishes an alias.
7134 if Ekind (E) = E_Variable
7135 and then Dynamic_Elaboration_Checks
7136 and then Nkind (Par) /= N_Object_Renaming_Declaration
7138 Check_Elab_Call (N);
7141 -- The variable may eventually become a constituent of a single
7142 -- protected/task type. Record the reference now and verify its
7143 -- legality when analyzing the contract of the variable
7146 if Ekind (E) = E_Variable then
7147 Record_Possible_Part_Of_Reference (E, N);
7151 -- A Ghost entity must appear in a specific context
7153 if Is_Ghost_Entity (E) then
7154 Check_Ghost_Context (E, N);
7157 end Resolve_Entity_Name;
7163 procedure Resolve_Entry (Entry_Name : Node_Id) is
7164 Loc : constant Source_Ptr := Sloc (Entry_Name);
7172 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7173 -- If the bounds of the entry family being called depend on task
7174 -- discriminants, build a new index subtype where a discriminant is
7175 -- replaced with the value of the discriminant of the target task.
7176 -- The target task is the prefix of the entry name in the call.
7178 -----------------------
7179 -- Actual_Index_Type --
7180 -----------------------
7182 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7183 Typ : constant Entity_Id := Entry_Index_Type (E);
7184 Tsk : constant Entity_Id := Scope (E);
7185 Lo : constant Node_Id := Type_Low_Bound (Typ);
7186 Hi : constant Node_Id := Type_High_Bound (Typ);
7189 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7190 -- If the bound is given by a discriminant, replace with a reference
7191 -- to the discriminant of the same name in the target task. If the
7192 -- entry name is the target of a requeue statement and the entry is
7193 -- in the current protected object, the bound to be used is the
7194 -- discriminal of the object (see Apply_Range_Checks for details of
7195 -- the transformation).
7197 -----------------------------
7198 -- Actual_Discriminant_Ref --
7199 -----------------------------
7201 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7202 Typ : constant Entity_Id := Etype (Bound);
7206 Remove_Side_Effects (Bound);
7208 if not Is_Entity_Name (Bound)
7209 or else Ekind (Entity (Bound)) /= E_Discriminant
7213 elsif Is_Protected_Type (Tsk)
7214 and then In_Open_Scopes (Tsk)
7215 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7217 -- Note: here Bound denotes a discriminant of the corresponding
7218 -- record type tskV, whose discriminal is a formal of the
7219 -- init-proc tskVIP. What we want is the body discriminal,
7220 -- which is associated to the discriminant of the original
7221 -- concurrent type tsk.
7223 return New_Occurrence_Of
7224 (Find_Body_Discriminal (Entity (Bound)), Loc);
7228 Make_Selected_Component (Loc,
7229 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7230 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7235 end Actual_Discriminant_Ref;
7237 -- Start of processing for Actual_Index_Type
7240 if not Has_Discriminants (Tsk)
7241 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7243 return Entry_Index_Type (E);
7246 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7247 Set_Etype (New_T, Base_Type (Typ));
7248 Set_Size_Info (New_T, Typ);
7249 Set_RM_Size (New_T, RM_Size (Typ));
7250 Set_Scalar_Range (New_T,
7251 Make_Range (Sloc (Entry_Name),
7252 Low_Bound => Actual_Discriminant_Ref (Lo),
7253 High_Bound => Actual_Discriminant_Ref (Hi)));
7257 end Actual_Index_Type;
7259 -- Start of processing for Resolve_Entry
7262 -- Find name of entry being called, and resolve prefix of name with its
7263 -- own type. The prefix can be overloaded, and the name and signature of
7264 -- the entry must be taken into account.
7266 if Nkind (Entry_Name) = N_Indexed_Component then
7268 -- Case of dealing with entry family within the current tasks
7270 E_Name := Prefix (Entry_Name);
7273 E_Name := Entry_Name;
7276 if Is_Entity_Name (E_Name) then
7278 -- Entry call to an entry (or entry family) in the current task. This
7279 -- is legal even though the task will deadlock. Rewrite as call to
7282 -- This can also be a call to an entry in an enclosing task. If this
7283 -- is a single task, we have to retrieve its name, because the scope
7284 -- of the entry is the task type, not the object. If the enclosing
7285 -- task is a task type, the identity of the task is given by its own
7288 -- Finally this can be a requeue on an entry of the same task or
7289 -- protected object.
7291 S := Scope (Entity (E_Name));
7293 for J in reverse 0 .. Scope_Stack.Last loop
7294 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7295 and then not Comes_From_Source (S)
7297 -- S is an enclosing task or protected object. The concurrent
7298 -- declaration has been converted into a type declaration, and
7299 -- the object itself has an object declaration that follows
7300 -- the type in the same declarative part.
7302 Tsk := Next_Entity (S);
7303 while Etype (Tsk) /= S loop
7310 elsif S = Scope_Stack.Table (J).Entity then
7312 -- Call to current task. Will be transformed into call to Self
7320 Make_Selected_Component (Loc,
7321 Prefix => New_Occurrence_Of (S, Loc),
7323 New_Occurrence_Of (Entity (E_Name), Loc));
7324 Rewrite (E_Name, New_N);
7327 elsif Nkind (Entry_Name) = N_Selected_Component
7328 and then Is_Overloaded (Prefix (Entry_Name))
7330 -- Use the entry name (which must be unique at this point) to find
7331 -- the prefix that returns the corresponding task/protected type.
7334 Pref : constant Node_Id := Prefix (Entry_Name);
7335 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7340 Get_First_Interp (Pref, I, It);
7341 while Present (It.Typ) loop
7342 if Scope (Ent) = It.Typ then
7343 Set_Etype (Pref, It.Typ);
7347 Get_Next_Interp (I, It);
7352 if Nkind (Entry_Name) = N_Selected_Component then
7353 Resolve (Prefix (Entry_Name));
7355 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7356 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7357 Resolve (Prefix (Prefix (Entry_Name)));
7358 Index := First (Expressions (Entry_Name));
7359 Resolve (Index, Entry_Index_Type (Nam));
7361 -- Up to this point the expression could have been the actual in a
7362 -- simple entry call, and be given by a named association.
7364 if Nkind (Index) = N_Parameter_Association then
7365 Error_Msg_N ("expect expression for entry index", Index);
7367 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7372 ------------------------
7373 -- Resolve_Entry_Call --
7374 ------------------------
7376 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7377 Entry_Name : constant Node_Id := Name (N);
7378 Loc : constant Source_Ptr := Sloc (Entry_Name);
7380 First_Named : Node_Id;
7387 -- We kill all checks here, because it does not seem worth the effort to
7388 -- do anything better, an entry call is a big operation.
7392 -- Processing of the name is similar for entry calls and protected
7393 -- operation calls. Once the entity is determined, we can complete
7394 -- the resolution of the actuals.
7396 -- The selector may be overloaded, in the case of a protected object
7397 -- with overloaded functions. The type of the context is used for
7400 if Nkind (Entry_Name) = N_Selected_Component
7401 and then Is_Overloaded (Selector_Name (Entry_Name))
7402 and then Typ /= Standard_Void_Type
7409 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7410 while Present (It.Typ) loop
7411 if Covers (Typ, It.Typ) then
7412 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7413 Set_Etype (Entry_Name, It.Typ);
7415 Generate_Reference (It.Typ, N, ' ');
7418 Get_Next_Interp (I, It);
7423 Resolve_Entry (Entry_Name);
7425 if Nkind (Entry_Name) = N_Selected_Component then
7427 -- Simple entry call
7429 Nam := Entity (Selector_Name (Entry_Name));
7430 Obj := Prefix (Entry_Name);
7431 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7433 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7435 -- Call to member of entry family
7437 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7438 Obj := Prefix (Prefix (Entry_Name));
7439 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7442 -- We cannot in general check the maximum depth of protected entry calls
7443 -- at compile time. But we can tell that any protected entry call at all
7444 -- violates a specified nesting depth of zero.
7446 if Is_Protected_Type (Scope (Nam)) then
7447 Check_Restriction (Max_Entry_Queue_Length, N);
7450 -- Use context type to disambiguate a protected function that can be
7451 -- called without actuals and that returns an array type, and where the
7452 -- argument list may be an indexing of the returned value.
7454 if Ekind (Nam) = E_Function
7455 and then Needs_No_Actuals (Nam)
7456 and then Present (Parameter_Associations (N))
7458 ((Is_Array_Type (Etype (Nam))
7459 and then Covers (Typ, Component_Type (Etype (Nam))))
7461 or else (Is_Access_Type (Etype (Nam))
7462 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7466 Component_Type (Designated_Type (Etype (Nam))))))
7469 Index_Node : Node_Id;
7473 Make_Indexed_Component (Loc,
7475 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7476 Expressions => Parameter_Associations (N));
7478 -- Since we are correcting a node classification error made by the
7479 -- parser, we call Replace rather than Rewrite.
7481 Replace (N, Index_Node);
7482 Set_Etype (Prefix (N), Etype (Nam));
7484 Resolve_Indexed_Component (N, Typ);
7489 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7490 and then Present (Contract_Wrapper (Nam))
7491 and then Current_Scope /= Contract_Wrapper (Nam)
7494 -- Note the entity being called before rewriting the call, so that
7495 -- it appears used at this point.
7497 Generate_Reference (Nam, Entry_Name, 'r');
7499 -- Rewrite as call to the precondition wrapper, adding the task
7500 -- object to the list of actuals. If the call is to a member of an
7501 -- entry family, include the index as well.
7505 New_Actuals : List_Id;
7508 New_Actuals := New_List (Obj);
7510 if Nkind (Entry_Name) = N_Indexed_Component then
7511 Append_To (New_Actuals,
7512 New_Copy_Tree (First (Expressions (Entry_Name))));
7515 Append_List (Parameter_Associations (N), New_Actuals);
7517 Make_Procedure_Call_Statement (Loc,
7519 New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
7520 Parameter_Associations => New_Actuals);
7521 Rewrite (N, New_Call);
7523 -- Preanalyze and resolve new call. Current procedure is called
7524 -- from Resolve_Call, after which expansion will take place.
7526 Preanalyze_And_Resolve (N);
7531 -- The operation name may have been overloaded. Order the actuals
7532 -- according to the formals of the resolved entity, and set the return
7533 -- type to that of the operation.
7536 Normalize_Actuals (N, Nam, False, Norm_OK);
7537 pragma Assert (Norm_OK);
7538 Set_Etype (N, Etype (Nam));
7540 -- Reset the Is_Overloaded flag, since resolution is now completed
7542 -- Simple entry call
7544 if Nkind (Entry_Name) = N_Selected_Component then
7545 Set_Is_Overloaded (Selector_Name (Entry_Name), False);
7547 -- Call to a member of an entry family
7549 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7550 Set_Is_Overloaded (Selector_Name (Prefix (Entry_Name)), False);
7554 Resolve_Actuals (N, Nam);
7555 Check_Internal_Protected_Use (N, Nam);
7557 -- Create a call reference to the entry
7559 Generate_Reference (Nam, Entry_Name, 's');
7561 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7562 Check_Potentially_Blocking_Operation (N);
7565 -- Verify that a procedure call cannot masquerade as an entry
7566 -- call where an entry call is expected.
7568 if Ekind (Nam) = E_Procedure then
7569 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7570 and then N = Entry_Call_Statement (Parent (N))
7572 Error_Msg_N ("entry call required in select statement", N);
7574 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7575 and then N = Triggering_Statement (Parent (N))
7577 Error_Msg_N ("triggering statement cannot be procedure call", N);
7579 elsif Ekind (Scope (Nam)) = E_Task_Type
7580 and then not In_Open_Scopes (Scope (Nam))
7582 Error_Msg_N ("task has no entry with this name", Entry_Name);
7586 -- After resolution, entry calls and protected procedure calls are
7587 -- changed into entry calls, for expansion. The structure of the node
7588 -- does not change, so it can safely be done in place. Protected
7589 -- function calls must keep their structure because they are
7592 if Ekind (Nam) /= E_Function then
7594 -- A protected operation that is not a function may modify the
7595 -- corresponding object, and cannot apply to a constant. If this
7596 -- is an internal call, the prefix is the type itself.
7598 if Is_Protected_Type (Scope (Nam))
7599 and then not Is_Variable (Obj)
7600 and then (not Is_Entity_Name (Obj)
7601 or else not Is_Type (Entity (Obj)))
7604 ("prefix of protected procedure or entry call must be variable",
7608 Actuals := Parameter_Associations (N);
7609 First_Named := First_Named_Actual (N);
7612 Make_Entry_Call_Statement (Loc,
7614 Parameter_Associations => Actuals));
7616 Set_First_Named_Actual (N, First_Named);
7617 Set_Analyzed (N, True);
7619 -- Protected functions can return on the secondary stack, in which
7620 -- case we must trigger the transient scope mechanism.
7622 elsif Expander_Active
7623 and then Requires_Transient_Scope (Etype (Nam))
7625 Establish_Transient_Scope (N, Sec_Stack => True);
7627 end Resolve_Entry_Call;
7629 -------------------------
7630 -- Resolve_Equality_Op --
7631 -------------------------
7633 -- Both arguments must have the same type, and the boolean context does
7634 -- not participate in the resolution. The first pass verifies that the
7635 -- interpretation is not ambiguous, and the type of the left argument is
7636 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7637 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7638 -- though they carry a single (universal) type. Diagnose this case here.
7640 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7641 L : constant Node_Id := Left_Opnd (N);
7642 R : constant Node_Id := Right_Opnd (N);
7643 T : Entity_Id := Find_Unique_Type (L, R);
7645 procedure Check_If_Expression (Cond : Node_Id);
7646 -- The resolution rule for if expressions requires that each such must
7647 -- have a unique type. This means that if several dependent expressions
7648 -- are of a non-null anonymous access type, and the context does not
7649 -- impose an expected type (as can be the case in an equality operation)
7650 -- the expression must be rejected.
7652 procedure Explain_Redundancy (N : Node_Id);
7653 -- Attempt to explain the nature of a redundant comparison with True. If
7654 -- the expression N is too complex, this routine issues a general error
7657 function Find_Unique_Access_Type return Entity_Id;
7658 -- In the case of allocators and access attributes, the context must
7659 -- provide an indication of the specific access type to be used. If
7660 -- one operand is of such a "generic" access type, check whether there
7661 -- is a specific visible access type that has the same designated type.
7662 -- This is semantically dubious, and of no interest to any real code,
7663 -- but c48008a makes it all worthwhile.
7665 -------------------------
7666 -- Check_If_Expression --
7667 -------------------------
7669 procedure Check_If_Expression (Cond : Node_Id) is
7670 Then_Expr : Node_Id;
7671 Else_Expr : Node_Id;
7674 if Nkind (Cond) = N_If_Expression then
7675 Then_Expr := Next (First (Expressions (Cond)));
7676 Else_Expr := Next (Then_Expr);
7678 if Nkind (Then_Expr) /= N_Null
7679 and then Nkind (Else_Expr) /= N_Null
7681 Error_Msg_N ("cannot determine type of if expression", Cond);
7684 end Check_If_Expression;
7686 ------------------------
7687 -- Explain_Redundancy --
7688 ------------------------
7690 procedure Explain_Redundancy (N : Node_Id) is
7698 -- Strip the operand down to an entity
7701 if Nkind (Val) = N_Selected_Component then
7702 Val := Selector_Name (Val);
7708 -- The construct denotes an entity
7710 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7711 Val_Id := Entity (Val);
7713 -- Do not generate an error message when the comparison is done
7714 -- against the enumeration literal Standard.True.
7716 if Ekind (Val_Id) /= E_Enumeration_Literal then
7718 -- Build a customized error message
7721 Add_Str_To_Name_Buffer ("?r?");
7723 if Ekind (Val_Id) = E_Component then
7724 Add_Str_To_Name_Buffer ("component ");
7726 elsif Ekind (Val_Id) = E_Constant then
7727 Add_Str_To_Name_Buffer ("constant ");
7729 elsif Ekind (Val_Id) = E_Discriminant then
7730 Add_Str_To_Name_Buffer ("discriminant ");
7732 elsif Is_Formal (Val_Id) then
7733 Add_Str_To_Name_Buffer ("parameter ");
7735 elsif Ekind (Val_Id) = E_Variable then
7736 Add_Str_To_Name_Buffer ("variable ");
7739 Add_Str_To_Name_Buffer ("& is always True!");
7742 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7745 -- The construct is too complex to disect, issue a general message
7748 Error_Msg_N ("?r?expression is always True!", Val);
7750 end Explain_Redundancy;
7752 -----------------------------
7753 -- Find_Unique_Access_Type --
7754 -----------------------------
7756 function Find_Unique_Access_Type return Entity_Id is
7762 if Ekind_In (Etype (R), E_Allocator_Type,
7763 E_Access_Attribute_Type)
7765 Acc := Designated_Type (Etype (R));
7767 elsif Ekind_In (Etype (L), E_Allocator_Type,
7768 E_Access_Attribute_Type)
7770 Acc := Designated_Type (Etype (L));
7776 while S /= Standard_Standard loop
7777 E := First_Entity (S);
7778 while Present (E) loop
7780 and then Is_Access_Type (E)
7781 and then Ekind (E) /= E_Allocator_Type
7782 and then Designated_Type (E) = Base_Type (Acc)
7794 end Find_Unique_Access_Type;
7796 -- Start of processing for Resolve_Equality_Op
7799 Set_Etype (N, Base_Type (Typ));
7800 Generate_Reference (T, N, ' ');
7802 if T = Any_Fixed then
7803 T := Unique_Fixed_Point_Type (L);
7806 if T /= Any_Type then
7807 if T = Any_String or else
7808 T = Any_Composite or else
7811 if T = Any_Character then
7812 Ambiguous_Character (L);
7814 Error_Msg_N ("ambiguous operands for equality", N);
7817 Set_Etype (N, Any_Type);
7820 elsif T = Any_Access
7821 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7823 T := Find_Unique_Access_Type;
7826 Error_Msg_N ("ambiguous operands for equality", N);
7827 Set_Etype (N, Any_Type);
7831 -- If expressions must have a single type, and if the context does
7832 -- not impose one the dependent expressions cannot be anonymous
7835 -- Why no similar processing for case expressions???
7837 elsif Ada_Version >= Ada_2012
7838 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7839 E_Anonymous_Access_Subprogram_Type)
7840 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7841 E_Anonymous_Access_Subprogram_Type)
7843 Check_If_Expression (L);
7844 Check_If_Expression (R);
7850 -- In SPARK, equality operators = and /= for array types other than
7851 -- String are only defined when, for each index position, the
7852 -- operands have equal static bounds.
7854 if Is_Array_Type (T) then
7856 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7857 -- operation if not needed.
7859 if Restriction_Check_Required (SPARK_05)
7860 and then Base_Type (T) /= Standard_String
7861 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7862 and then Etype (L) /= Any_Composite -- or else L in error
7863 and then Etype (R) /= Any_Composite -- or else R in error
7864 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7866 Check_SPARK_05_Restriction
7867 ("array types should have matching static bounds", N);
7871 -- If the unique type is a class-wide type then it will be expanded
7872 -- into a dispatching call to the predefined primitive. Therefore we
7873 -- check here for potential violation of such restriction.
7875 if Is_Class_Wide_Type (T) then
7876 Check_Restriction (No_Dispatching_Calls, N);
7879 if Warn_On_Redundant_Constructs
7880 and then Comes_From_Source (N)
7881 and then Comes_From_Source (R)
7882 and then Is_Entity_Name (R)
7883 and then Entity (R) = Standard_True
7885 Error_Msg_N -- CODEFIX
7886 ("?r?comparison with True is redundant!", N);
7887 Explain_Redundancy (Original_Node (R));
7890 Check_Unset_Reference (L);
7891 Check_Unset_Reference (R);
7892 Generate_Operator_Reference (N, T);
7893 Check_Low_Bound_Tested (N);
7895 -- If this is an inequality, it may be the implicit inequality
7896 -- created for a user-defined operation, in which case the corres-
7897 -- ponding equality operation is not intrinsic, and the operation
7898 -- cannot be constant-folded. Else fold.
7900 if Nkind (N) = N_Op_Eq
7901 or else Comes_From_Source (Entity (N))
7902 or else Ekind (Entity (N)) = E_Operator
7903 or else Is_Intrinsic_Subprogram
7904 (Corresponding_Equality (Entity (N)))
7906 Analyze_Dimension (N);
7907 Eval_Relational_Op (N);
7909 elsif Nkind (N) = N_Op_Ne
7910 and then Is_Abstract_Subprogram (Entity (N))
7912 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7915 -- Ada 2005: If one operand is an anonymous access type, convert the
7916 -- other operand to it, to ensure that the underlying types match in
7917 -- the back-end. Same for access_to_subprogram, and the conversion
7918 -- verifies that the types are subtype conformant.
7920 -- We apply the same conversion in the case one of the operands is a
7921 -- private subtype of the type of the other.
7923 -- Why the Expander_Active test here ???
7927 (Ekind_In (T, E_Anonymous_Access_Type,
7928 E_Anonymous_Access_Subprogram_Type)
7929 or else Is_Private_Type (T))
7931 if Etype (L) /= T then
7933 Make_Unchecked_Type_Conversion (Sloc (L),
7934 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7935 Expression => Relocate_Node (L)));
7936 Analyze_And_Resolve (L, T);
7939 if (Etype (R)) /= T then
7941 Make_Unchecked_Type_Conversion (Sloc (R),
7942 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7943 Expression => Relocate_Node (R)));
7944 Analyze_And_Resolve (R, T);
7948 end Resolve_Equality_Op;
7950 ----------------------------------
7951 -- Resolve_Explicit_Dereference --
7952 ----------------------------------
7954 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7955 Loc : constant Source_Ptr := Sloc (N);
7957 P : constant Node_Id := Prefix (N);
7960 -- The candidate prefix type, if overloaded
7966 Check_Fully_Declared_Prefix (Typ, P);
7969 -- A useful optimization: check whether the dereference denotes an
7970 -- element of a container, and if so rewrite it as a call to the
7971 -- corresponding Element function.
7973 -- Disabled for now, on advice of ARG. A more restricted form of the
7974 -- predicate might be acceptable ???
7976 -- if Is_Container_Element (N) then
7980 if Is_Overloaded (P) then
7982 -- Use the context type to select the prefix that has the correct
7983 -- designated type. Keep the first match, which will be the inner-
7986 Get_First_Interp (P, I, It);
7988 while Present (It.Typ) loop
7989 if Is_Access_Type (It.Typ)
7990 and then Covers (Typ, Designated_Type (It.Typ))
7996 -- Remove access types that do not match, but preserve access
7997 -- to subprogram interpretations, in case a further dereference
7998 -- is needed (see below).
8000 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8004 Get_Next_Interp (I, It);
8007 if Present (P_Typ) then
8009 Set_Etype (N, Designated_Type (P_Typ));
8012 -- If no interpretation covers the designated type of the prefix,
8013 -- this is the pathological case where not all implementations of
8014 -- the prefix allow the interpretation of the node as a call. Now
8015 -- that the expected type is known, Remove other interpretations
8016 -- from prefix, rewrite it as a call, and resolve again, so that
8017 -- the proper call node is generated.
8019 Get_First_Interp (P, I, It);
8020 while Present (It.Typ) loop
8021 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8025 Get_Next_Interp (I, It);
8029 Make_Function_Call (Loc,
8031 Make_Explicit_Dereference (Loc,
8033 Parameter_Associations => New_List);
8035 Save_Interps (N, New_N);
8037 Analyze_And_Resolve (N, Typ);
8041 -- If not overloaded, resolve P with its own type
8047 -- If the prefix might be null, add an access check
8049 if Is_Access_Type (Etype (P))
8050 and then not Can_Never_Be_Null (Etype (P))
8052 Apply_Access_Check (N);
8055 -- If the designated type is a packed unconstrained array type, and the
8056 -- explicit dereference is not in the context of an attribute reference,
8057 -- then we must compute and set the actual subtype, since it is needed
8058 -- by Gigi. The reason we exclude the attribute case is that this is
8059 -- handled fine by Gigi, and in fact we use such attributes to build the
8060 -- actual subtype. We also exclude generated code (which builds actual
8061 -- subtypes directly if they are needed).
8063 if Is_Array_Type (Etype (N))
8064 and then Is_Packed (Etype (N))
8065 and then not Is_Constrained (Etype (N))
8066 and then Nkind (Parent (N)) /= N_Attribute_Reference
8067 and then Comes_From_Source (N)
8069 Set_Etype (N, Get_Actual_Subtype (N));
8072 Analyze_Dimension (N);
8074 -- Note: No Eval processing is required for an explicit dereference,
8075 -- because such a name can never be static.
8077 end Resolve_Explicit_Dereference;
8079 -------------------------------------
8080 -- Resolve_Expression_With_Actions --
8081 -------------------------------------
8083 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8087 -- If N has no actions, and its expression has been constant folded,
8088 -- then rewrite N as just its expression. Note, we can't do this in
8089 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8090 -- Expression (N) to be expanded again.
8092 if Is_Empty_List (Actions (N))
8093 and then Compile_Time_Known_Value (Expression (N))
8095 Rewrite (N, Expression (N));
8097 end Resolve_Expression_With_Actions;
8099 ----------------------------------
8100 -- Resolve_Generalized_Indexing --
8101 ----------------------------------
8103 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8104 Indexing : constant Node_Id := Generalized_Indexing (N);
8110 -- In ASIS mode, propagate the information about the indexes back to
8111 -- to the original indexing node. The generalized indexing is either
8112 -- a function call, or a dereference of one. The actuals include the
8113 -- prefix of the original node, which is the container expression.
8116 Resolve (Indexing, Typ);
8117 Set_Etype (N, Etype (Indexing));
8118 Set_Is_Overloaded (N, False);
8121 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8123 Call := Prefix (Call);
8126 if Nkind (Call) = N_Function_Call then
8127 Indexes := Parameter_Associations (Call);
8128 Pref := Remove_Head (Indexes);
8129 Set_Expressions (N, Indexes);
8131 -- If expression is to be reanalyzed, reset Generalized_Indexing
8132 -- to recreate call node, as is the case when the expression is
8133 -- part of an expression function.
8135 if In_Spec_Expression then
8136 Set_Generalized_Indexing (N, Empty);
8139 Set_Prefix (N, Pref);
8143 Rewrite (N, Indexing);
8146 end Resolve_Generalized_Indexing;
8148 ---------------------------
8149 -- Resolve_If_Expression --
8150 ---------------------------
8152 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8153 Condition : constant Node_Id := First (Expressions (N));
8154 Then_Expr : constant Node_Id := Next (Condition);
8155 Else_Expr : Node_Id := Next (Then_Expr);
8156 Else_Typ : Entity_Id;
8157 Then_Typ : Entity_Id;
8160 Resolve (Condition, Any_Boolean);
8161 Resolve (Then_Expr, Typ);
8162 Then_Typ := Etype (Then_Expr);
8164 -- When the "then" expression is of a scalar subtype different from the
8165 -- result subtype, then insert a conversion to ensure the generation of
8166 -- a constraint check. The same is done for the else part below, again
8167 -- comparing subtypes rather than base types.
8169 if Is_Scalar_Type (Then_Typ)
8170 and then Then_Typ /= Typ
8172 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8173 Analyze_And_Resolve (Then_Expr, Typ);
8176 -- If ELSE expression present, just resolve using the determined type
8177 -- If type is universal, resolve to any member of the class.
8179 if Present (Else_Expr) then
8180 if Typ = Universal_Integer then
8181 Resolve (Else_Expr, Any_Integer);
8183 elsif Typ = Universal_Real then
8184 Resolve (Else_Expr, Any_Real);
8187 Resolve (Else_Expr, Typ);
8190 Else_Typ := Etype (Else_Expr);
8192 if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
8193 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8194 Analyze_And_Resolve (Else_Expr, Typ);
8196 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8197 -- dynamically tagged must be known statically.
8199 elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8200 if Is_Dynamically_Tagged (Then_Expr) /=
8201 Is_Dynamically_Tagged (Else_Expr)
8203 Error_Msg_N ("all or none of the dependent expressions "
8204 & "can be dynamically tagged", N);
8208 -- If no ELSE expression is present, root type must be Standard.Boolean
8209 -- and we provide a Standard.True result converted to the appropriate
8210 -- Boolean type (in case it is a derived boolean type).
8212 elsif Root_Type (Typ) = Standard_Boolean then
8214 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8215 Analyze_And_Resolve (Else_Expr, Typ);
8216 Append_To (Expressions (N), Else_Expr);
8219 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8220 Append_To (Expressions (N), Error);
8224 Eval_If_Expression (N);
8225 end Resolve_If_Expression;
8227 -------------------------------
8228 -- Resolve_Indexed_Component --
8229 -------------------------------
8231 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8232 Name : constant Node_Id := Prefix (N);
8234 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8238 if Present (Generalized_Indexing (N)) then
8239 Resolve_Generalized_Indexing (N, Typ);
8243 if Is_Overloaded (Name) then
8245 -- Use the context type to select the prefix that yields the correct
8251 I1 : Interp_Index := 0;
8252 P : constant Node_Id := Prefix (N);
8253 Found : Boolean := False;
8256 Get_First_Interp (P, I, It);
8257 while Present (It.Typ) loop
8258 if (Is_Array_Type (It.Typ)
8259 and then Covers (Typ, Component_Type (It.Typ)))
8260 or else (Is_Access_Type (It.Typ)
8261 and then Is_Array_Type (Designated_Type (It.Typ))
8265 Component_Type (Designated_Type (It.Typ))))
8268 It := Disambiguate (P, I1, I, Any_Type);
8270 if It = No_Interp then
8271 Error_Msg_N ("ambiguous prefix for indexing", N);
8277 Array_Type := It.Typ;
8283 Array_Type := It.Typ;
8288 Get_Next_Interp (I, It);
8293 Array_Type := Etype (Name);
8296 Resolve (Name, Array_Type);
8297 Array_Type := Get_Actual_Subtype_If_Available (Name);
8299 -- If prefix is access type, dereference to get real array type.
8300 -- Note: we do not apply an access check because the expander always
8301 -- introduces an explicit dereference, and the check will happen there.
8303 if Is_Access_Type (Array_Type) then
8304 Array_Type := Designated_Type (Array_Type);
8307 -- If name was overloaded, set component type correctly now
8308 -- If a misplaced call to an entry family (which has no index types)
8309 -- return. Error will be diagnosed from calling context.
8311 if Is_Array_Type (Array_Type) then
8312 Set_Etype (N, Component_Type (Array_Type));
8317 Index := First_Index (Array_Type);
8318 Expr := First (Expressions (N));
8320 -- The prefix may have resolved to a string literal, in which case its
8321 -- etype has a special representation. This is only possible currently
8322 -- if the prefix is a static concatenation, written in functional
8325 if Ekind (Array_Type) = E_String_Literal_Subtype then
8326 Resolve (Expr, Standard_Positive);
8329 while Present (Index) and Present (Expr) loop
8330 Resolve (Expr, Etype (Index));
8331 Check_Unset_Reference (Expr);
8333 if Is_Scalar_Type (Etype (Expr)) then
8334 Apply_Scalar_Range_Check (Expr, Etype (Index));
8336 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8344 Analyze_Dimension (N);
8346 -- Do not generate the warning on suspicious index if we are analyzing
8347 -- package Ada.Tags; otherwise we will report the warning with the
8348 -- Prims_Ptr field of the dispatch table.
8350 if Scope (Etype (Prefix (N))) = Standard_Standard
8352 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8355 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8356 Eval_Indexed_Component (N);
8359 -- If the array type is atomic, and the component is not atomic, then
8360 -- this is worth a warning, since we have a situation where the access
8361 -- to the component may cause extra read/writes of the atomic array
8362 -- object, or partial word accesses, which could be unexpected.
8364 if Nkind (N) = N_Indexed_Component
8365 and then Is_Atomic_Ref_With_Address (N)
8366 and then not (Has_Atomic_Components (Array_Type)
8367 or else (Is_Entity_Name (Prefix (N))
8368 and then Has_Atomic_Components
8369 (Entity (Prefix (N)))))
8370 and then not Is_Atomic (Component_Type (Array_Type))
8373 ("??access to non-atomic component of atomic array", Prefix (N));
8375 ("??\may cause unexpected accesses to atomic object", Prefix (N));
8377 end Resolve_Indexed_Component;
8379 -----------------------------
8380 -- Resolve_Integer_Literal --
8381 -----------------------------
8383 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8386 Eval_Integer_Literal (N);
8387 end Resolve_Integer_Literal;
8389 --------------------------------
8390 -- Resolve_Intrinsic_Operator --
8391 --------------------------------
8393 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8394 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8399 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8400 -- If the operand is a literal, it cannot be the expression in a
8401 -- conversion. Use a qualified expression instead.
8403 ---------------------
8404 -- Convert_Operand --
8405 ---------------------
8407 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8408 Loc : constant Source_Ptr := Sloc (Opnd);
8412 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8414 Make_Qualified_Expression (Loc,
8415 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8416 Expression => Relocate_Node (Opnd));
8420 Res := Unchecked_Convert_To (Btyp, Opnd);
8424 end Convert_Operand;
8426 -- Start of processing for Resolve_Intrinsic_Operator
8429 -- We must preserve the original entity in a generic setting, so that
8430 -- the legality of the operation can be verified in an instance.
8432 if not Expander_Active then
8437 while Scope (Op) /= Standard_Standard loop
8439 pragma Assert (Present (Op));
8443 Set_Is_Overloaded (N, False);
8445 -- If the result or operand types are private, rewrite with unchecked
8446 -- conversions on the operands and the result, to expose the proper
8447 -- underlying numeric type.
8449 if Is_Private_Type (Typ)
8450 or else Is_Private_Type (Etype (Left_Opnd (N)))
8451 or else Is_Private_Type (Etype (Right_Opnd (N)))
8453 Arg1 := Convert_Operand (Left_Opnd (N));
8455 if Nkind (N) = N_Op_Expon then
8456 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8458 Arg2 := Convert_Operand (Right_Opnd (N));
8461 if Nkind (Arg1) = N_Type_Conversion then
8462 Save_Interps (Left_Opnd (N), Expression (Arg1));
8465 if Nkind (Arg2) = N_Type_Conversion then
8466 Save_Interps (Right_Opnd (N), Expression (Arg2));
8469 Set_Left_Opnd (N, Arg1);
8470 Set_Right_Opnd (N, Arg2);
8472 Set_Etype (N, Btyp);
8473 Rewrite (N, Unchecked_Convert_To (Typ, N));
8476 elsif Typ /= Etype (Left_Opnd (N))
8477 or else Typ /= Etype (Right_Opnd (N))
8479 -- Add explicit conversion where needed, and save interpretations in
8480 -- case operands are overloaded.
8482 Arg1 := Convert_To (Typ, Left_Opnd (N));
8483 Arg2 := Convert_To (Typ, Right_Opnd (N));
8485 if Nkind (Arg1) = N_Type_Conversion then
8486 Save_Interps (Left_Opnd (N), Expression (Arg1));
8488 Save_Interps (Left_Opnd (N), Arg1);
8491 if Nkind (Arg2) = N_Type_Conversion then
8492 Save_Interps (Right_Opnd (N), Expression (Arg2));
8494 Save_Interps (Right_Opnd (N), Arg2);
8497 Rewrite (Left_Opnd (N), Arg1);
8498 Rewrite (Right_Opnd (N), Arg2);
8501 Resolve_Arithmetic_Op (N, Typ);
8504 Resolve_Arithmetic_Op (N, Typ);
8506 end Resolve_Intrinsic_Operator;
8508 --------------------------------------
8509 -- Resolve_Intrinsic_Unary_Operator --
8510 --------------------------------------
8512 procedure Resolve_Intrinsic_Unary_Operator
8516 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8522 while Scope (Op) /= Standard_Standard loop
8524 pragma Assert (Present (Op));
8529 if Is_Private_Type (Typ) then
8530 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8531 Save_Interps (Right_Opnd (N), Expression (Arg2));
8533 Set_Right_Opnd (N, Arg2);
8535 Set_Etype (N, Btyp);
8536 Rewrite (N, Unchecked_Convert_To (Typ, N));
8540 Resolve_Unary_Op (N, Typ);
8542 end Resolve_Intrinsic_Unary_Operator;
8544 ------------------------
8545 -- Resolve_Logical_Op --
8546 ------------------------
8548 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8552 Check_No_Direct_Boolean_Operators (N);
8554 -- Predefined operations on scalar types yield the base type. On the
8555 -- other hand, logical operations on arrays yield the type of the
8556 -- arguments (and the context).
8558 if Is_Array_Type (Typ) then
8561 B_Typ := Base_Type (Typ);
8564 -- The following test is required because the operands of the operation
8565 -- may be literals, in which case the resulting type appears to be
8566 -- compatible with a signed integer type, when in fact it is compatible
8567 -- only with modular types. If the context itself is universal, the
8568 -- operation is illegal.
8570 if not Valid_Boolean_Arg (Typ) then
8571 Error_Msg_N ("invalid context for logical operation", N);
8572 Set_Etype (N, Any_Type);
8575 elsif Typ = Any_Modular then
8577 ("no modular type available in this context", N);
8578 Set_Etype (N, Any_Type);
8581 elsif Is_Modular_Integer_Type (Typ)
8582 and then Etype (Left_Opnd (N)) = Universal_Integer
8583 and then Etype (Right_Opnd (N)) = Universal_Integer
8585 Check_For_Visible_Operator (N, B_Typ);
8588 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8589 -- is active and the result type is standard Boolean (do not mess with
8590 -- ops that return a nonstandard Boolean type, because something strange
8593 -- Note: you might expect this replacement to be done during expansion,
8594 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8595 -- is used, no part of the right operand of an "and" or "or" operator
8596 -- should be executed if the left operand would short-circuit the
8597 -- evaluation of the corresponding "and then" or "or else". If we left
8598 -- the replacement to expansion time, then run-time checks associated
8599 -- with such operands would be evaluated unconditionally, due to being
8600 -- before the condition prior to the rewriting as short-circuit forms
8601 -- during expansion.
8603 if Short_Circuit_And_Or
8604 and then B_Typ = Standard_Boolean
8605 and then Nkind_In (N, N_Op_And, N_Op_Or)
8607 -- Mark the corresponding putative SCO operator as truly a logical
8608 -- (and short-circuit) operator.
8610 if Generate_SCO and then Comes_From_Source (N) then
8611 Set_SCO_Logical_Operator (N);
8614 if Nkind (N) = N_Op_And then
8616 Make_And_Then (Sloc (N),
8617 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8618 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8619 Analyze_And_Resolve (N, B_Typ);
8621 -- Case of OR changed to OR ELSE
8625 Make_Or_Else (Sloc (N),
8626 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8627 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8628 Analyze_And_Resolve (N, B_Typ);
8631 -- Return now, since analysis of the rewritten ops will take care of
8632 -- other reference bookkeeping and expression folding.
8637 Resolve (Left_Opnd (N), B_Typ);
8638 Resolve (Right_Opnd (N), B_Typ);
8640 Check_Unset_Reference (Left_Opnd (N));
8641 Check_Unset_Reference (Right_Opnd (N));
8643 Set_Etype (N, B_Typ);
8644 Generate_Operator_Reference (N, B_Typ);
8645 Eval_Logical_Op (N);
8647 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8648 -- only when both operands have same static lower and higher bounds. Of
8649 -- course the types have to match, so only check if operands are
8650 -- compatible and the node itself has no errors.
8652 if Is_Array_Type (B_Typ)
8653 and then Nkind (N) in N_Binary_Op
8656 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8657 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8660 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8661 -- operation if not needed.
8663 if Restriction_Check_Required (SPARK_05)
8664 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8665 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8666 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8667 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8669 Check_SPARK_05_Restriction
8670 ("array types should have matching static bounds", N);
8674 end Resolve_Logical_Op;
8676 ---------------------------
8677 -- Resolve_Membership_Op --
8678 ---------------------------
8680 -- The context can only be a boolean type, and does not determine the
8681 -- arguments. Arguments should be unambiguous, but the preference rule for
8682 -- universal types applies.
8684 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8685 pragma Warnings (Off, Typ);
8687 L : constant Node_Id := Left_Opnd (N);
8688 R : constant Node_Id := Right_Opnd (N);
8691 procedure Resolve_Set_Membership;
8692 -- Analysis has determined a unique type for the left operand. Use it to
8693 -- resolve the disjuncts.
8695 ----------------------------
8696 -- Resolve_Set_Membership --
8697 ----------------------------
8699 procedure Resolve_Set_Membership is
8704 -- If the left operand is overloaded, find type compatible with not
8705 -- overloaded alternative of the right operand.
8707 if Is_Overloaded (L) then
8709 Alt := First (Alternatives (N));
8710 while Present (Alt) loop
8711 if not Is_Overloaded (Alt) then
8712 Ltyp := Intersect_Types (L, Alt);
8719 -- Unclear how to resolve expression if all alternatives are also
8723 Error_Msg_N ("ambiguous expression", N);
8732 Alt := First (Alternatives (N));
8733 while Present (Alt) loop
8735 -- Alternative is an expression, a range
8736 -- or a subtype mark.
8738 if not Is_Entity_Name (Alt)
8739 or else not Is_Type (Entity (Alt))
8741 Resolve (Alt, Ltyp);
8747 -- Check for duplicates for discrete case
8749 if Is_Discrete_Type (Ltyp) then
8756 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8760 -- Loop checking duplicates. This is quadratic, but giant sets
8761 -- are unlikely in this context so it's a reasonable choice.
8764 Alt := First (Alternatives (N));
8765 while Present (Alt) loop
8766 if Is_OK_Static_Expression (Alt)
8767 and then (Nkind_In (Alt, N_Integer_Literal,
8768 N_Character_Literal)
8769 or else Nkind (Alt) in N_Has_Entity)
8772 Alts (Nalts) := (Alt, Expr_Value (Alt));
8774 for J in 1 .. Nalts - 1 loop
8775 if Alts (J).Val = Alts (Nalts).Val then
8776 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8777 Error_Msg_N ("duplicate of value given#??", Alt);
8786 end Resolve_Set_Membership;
8788 -- Start of processing for Resolve_Membership_Op
8791 if L = Error or else R = Error then
8795 if Present (Alternatives (N)) then
8796 Resolve_Set_Membership;
8799 elsif not Is_Overloaded (R)
8801 (Etype (R) = Universal_Integer
8803 Etype (R) = Universal_Real)
8804 and then Is_Overloaded (L)
8808 -- Ada 2005 (AI-251): Support the following case:
8810 -- type I is interface;
8811 -- type T is tagged ...
8813 -- function Test (O : I'Class) is
8815 -- return O in T'Class.
8818 -- In this case we have nothing else to do. The membership test will be
8819 -- done at run time.
8821 elsif Ada_Version >= Ada_2005
8822 and then Is_Class_Wide_Type (Etype (L))
8823 and then Is_Interface (Etype (L))
8824 and then Is_Class_Wide_Type (Etype (R))
8825 and then not Is_Interface (Etype (R))
8829 T := Intersect_Types (L, R);
8832 -- If mixed-mode operations are present and operands are all literal,
8833 -- the only interpretation involves Duration, which is probably not
8834 -- the intention of the programmer.
8836 if T = Any_Fixed then
8837 T := Unique_Fixed_Point_Type (N);
8839 if T = Any_Type then
8845 Check_Unset_Reference (L);
8847 if Nkind (R) = N_Range
8848 and then not Is_Scalar_Type (T)
8850 Error_Msg_N ("scalar type required for range", R);
8853 if Is_Entity_Name (R) then
8854 Freeze_Expression (R);
8857 Check_Unset_Reference (R);
8860 -- Here after resolving membership operation
8864 Eval_Membership_Op (N);
8865 end Resolve_Membership_Op;
8871 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8872 Loc : constant Source_Ptr := Sloc (N);
8875 -- Handle restriction against anonymous null access values This
8876 -- restriction can be turned off using -gnatdj.
8878 -- Ada 2005 (AI-231): Remove restriction
8880 if Ada_Version < Ada_2005
8881 and then not Debug_Flag_J
8882 and then Ekind (Typ) = E_Anonymous_Access_Type
8883 and then Comes_From_Source (N)
8885 -- In the common case of a call which uses an explicitly null value
8886 -- for an access parameter, give specialized error message.
8888 if Nkind (Parent (N)) in N_Subprogram_Call then
8890 ("null is not allowed as argument for an access parameter", N);
8892 -- Standard message for all other cases (are there any?)
8896 ("null cannot be of an anonymous access type", N);
8900 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8901 -- assignment to a null-excluding object
8903 if Ada_Version >= Ada_2005
8904 and then Can_Never_Be_Null (Typ)
8905 and then Nkind (Parent (N)) = N_Assignment_Statement
8907 if not Inside_Init_Proc then
8909 (Compile_Time_Constraint_Error (N,
8910 "(Ada 2005) null not allowed in null-excluding objects??"),
8911 Make_Raise_Constraint_Error (Loc,
8912 Reason => CE_Access_Check_Failed));
8915 Make_Raise_Constraint_Error (Loc,
8916 Reason => CE_Access_Check_Failed));
8920 -- In a distributed context, null for a remote access to subprogram may
8921 -- need to be replaced with a special record aggregate. In this case,
8922 -- return after having done the transformation.
8924 if (Ekind (Typ) = E_Record_Type
8925 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8926 and then Remote_AST_Null_Value (N, Typ)
8931 -- The null literal takes its type from the context
8936 -----------------------
8937 -- Resolve_Op_Concat --
8938 -----------------------
8940 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8942 -- We wish to avoid deep recursion, because concatenations are often
8943 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8944 -- operands nonrecursively until we find something that is not a simple
8945 -- concatenation (A in this case). We resolve that, and then walk back
8946 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8947 -- to do the rest of the work at each level. The Parent pointers allow
8948 -- us to avoid recursion, and thus avoid running out of memory. See also
8949 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8955 -- The following code is equivalent to:
8957 -- Resolve_Op_Concat_First (NN, Typ);
8958 -- Resolve_Op_Concat_Arg (N, ...);
8959 -- Resolve_Op_Concat_Rest (N, Typ);
8961 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8962 -- operand is a concatenation.
8964 -- Walk down left operands
8967 Resolve_Op_Concat_First (NN, Typ);
8968 Op1 := Left_Opnd (NN);
8969 exit when not (Nkind (Op1) = N_Op_Concat
8970 and then not Is_Array_Type (Component_Type (Typ))
8971 and then Entity (Op1) = Entity (NN));
8975 -- Now (given the above example) NN is A&B and Op1 is A
8977 -- First resolve Op1 ...
8979 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8981 -- ... then walk NN back up until we reach N (where we started), calling
8982 -- Resolve_Op_Concat_Rest along the way.
8985 Resolve_Op_Concat_Rest (NN, Typ);
8990 if Base_Type (Etype (N)) /= Standard_String then
8991 Check_SPARK_05_Restriction
8992 ("result of concatenation should have type String", N);
8994 end Resolve_Op_Concat;
8996 ---------------------------
8997 -- Resolve_Op_Concat_Arg --
8998 ---------------------------
9000 procedure Resolve_Op_Concat_Arg
9006 Btyp : constant Entity_Id := Base_Type (Typ);
9007 Ctyp : constant Entity_Id := Component_Type (Typ);
9012 or else (not Is_Overloaded (Arg)
9013 and then Etype (Arg) /= Any_Composite
9014 and then Covers (Ctyp, Etype (Arg)))
9016 Resolve (Arg, Ctyp);
9018 Resolve (Arg, Btyp);
9021 -- If both Array & Array and Array & Component are visible, there is a
9022 -- potential ambiguity that must be reported.
9024 elsif Has_Compatible_Type (Arg, Ctyp) then
9025 if Nkind (Arg) = N_Aggregate
9026 and then Is_Composite_Type (Ctyp)
9028 if Is_Private_Type (Ctyp) then
9029 Resolve (Arg, Btyp);
9031 -- If the operation is user-defined and not overloaded use its
9032 -- profile. The operation may be a renaming, in which case it has
9033 -- been rewritten, and we want the original profile.
9035 elsif not Is_Overloaded (N)
9036 and then Comes_From_Source (Entity (Original_Node (N)))
9037 and then Ekind (Entity (Original_Node (N))) = E_Function
9041 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9044 -- Otherwise an aggregate may match both the array type and the
9048 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9049 Set_Etype (Arg, Any_Type);
9053 if Is_Overloaded (Arg)
9054 and then Has_Compatible_Type (Arg, Typ)
9055 and then Etype (Arg) /= Any_Type
9063 Get_First_Interp (Arg, I, It);
9065 Get_Next_Interp (I, It);
9067 -- Special-case the error message when the overloading is
9068 -- caused by a function that yields an array and can be
9069 -- called without parameters.
9071 if It.Nam = Func then
9072 Error_Msg_Sloc := Sloc (Func);
9073 Error_Msg_N ("ambiguous call to function#", Arg);
9075 ("\\interpretation as call yields&", Arg, Typ);
9077 ("\\interpretation as indexing of call yields&",
9078 Arg, Component_Type (Typ));
9081 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9083 Get_First_Interp (Arg, I, It);
9084 while Present (It.Nam) loop
9085 Error_Msg_Sloc := Sloc (It.Nam);
9087 if Base_Type (It.Typ) = Btyp
9089 Base_Type (It.Typ) = Base_Type (Ctyp)
9091 Error_Msg_N -- CODEFIX
9092 ("\\possible interpretation#", Arg);
9095 Get_Next_Interp (I, It);
9101 Resolve (Arg, Component_Type (Typ));
9103 if Nkind (Arg) = N_String_Literal then
9104 Set_Etype (Arg, Component_Type (Typ));
9107 if Arg = Left_Opnd (N) then
9108 Set_Is_Component_Left_Opnd (N);
9110 Set_Is_Component_Right_Opnd (N);
9115 Resolve (Arg, Btyp);
9118 -- Concatenation is restricted in SPARK: each operand must be either a
9119 -- string literal, the name of a string constant, a static character or
9120 -- string expression, or another concatenation. Arg cannot be a
9121 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9122 -- separately on each final operand, past concatenation operations.
9124 if Is_Character_Type (Etype (Arg)) then
9125 if not Is_OK_Static_Expression (Arg) then
9126 Check_SPARK_05_Restriction
9127 ("character operand for concatenation should be static", Arg);
9130 elsif Is_String_Type (Etype (Arg)) then
9131 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9132 and then Is_Constant_Object (Entity (Arg)))
9133 and then not Is_OK_Static_Expression (Arg)
9135 Check_SPARK_05_Restriction
9136 ("string operand for concatenation should be static", Arg);
9139 -- Do not issue error on an operand that is neither a character nor a
9140 -- string, as the error is issued in Resolve_Op_Concat.
9146 Check_Unset_Reference (Arg);
9147 end Resolve_Op_Concat_Arg;
9149 -----------------------------
9150 -- Resolve_Op_Concat_First --
9151 -----------------------------
9153 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9154 Btyp : constant Entity_Id := Base_Type (Typ);
9155 Op1 : constant Node_Id := Left_Opnd (N);
9156 Op2 : constant Node_Id := Right_Opnd (N);
9159 -- The parser folds an enormous sequence of concatenations of string
9160 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9161 -- in the right operand. If the expression resolves to a predefined "&"
9162 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9163 -- we give an error. See P_Simple_Expression in Par.Ch4.
9165 if Nkind (Op2) = N_String_Literal
9166 and then Is_Folded_In_Parser (Op2)
9167 and then Ekind (Entity (N)) = E_Function
9169 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9170 and then String_Length (Strval (Op1)) = 0);
9171 Error_Msg_N ("too many user-defined concatenations", N);
9175 Set_Etype (N, Btyp);
9177 if Is_Limited_Composite (Btyp) then
9178 Error_Msg_N ("concatenation not available for limited array", N);
9179 Explain_Limited_Type (Btyp, N);
9181 end Resolve_Op_Concat_First;
9183 ----------------------------
9184 -- Resolve_Op_Concat_Rest --
9185 ----------------------------
9187 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9188 Op1 : constant Node_Id := Left_Opnd (N);
9189 Op2 : constant Node_Id := Right_Opnd (N);
9192 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9194 Generate_Operator_Reference (N, Typ);
9196 if Is_String_Type (Typ) then
9197 Eval_Concatenation (N);
9200 -- If this is not a static concatenation, but the result is a string
9201 -- type (and not an array of strings) ensure that static string operands
9202 -- have their subtypes properly constructed.
9204 if Nkind (N) /= N_String_Literal
9205 and then Is_Character_Type (Component_Type (Typ))
9207 Set_String_Literal_Subtype (Op1, Typ);
9208 Set_String_Literal_Subtype (Op2, Typ);
9210 end Resolve_Op_Concat_Rest;
9212 ----------------------
9213 -- Resolve_Op_Expon --
9214 ----------------------
9216 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9217 B_Typ : constant Entity_Id := Base_Type (Typ);
9220 -- Catch attempts to do fixed-point exponentiation with universal
9221 -- operands, which is a case where the illegality is not caught during
9222 -- normal operator analysis. This is not done in preanalysis mode
9223 -- since the tree is not fully decorated during preanalysis.
9225 if Full_Analysis then
9226 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9227 Error_Msg_N ("exponentiation not available for fixed point", N);
9230 elsif Nkind (Parent (N)) in N_Op
9231 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9232 and then Etype (N) = Universal_Real
9233 and then Comes_From_Source (N)
9235 Error_Msg_N ("exponentiation not available for fixed point", N);
9240 if Comes_From_Source (N)
9241 and then Ekind (Entity (N)) = E_Function
9242 and then Is_Imported (Entity (N))
9243 and then Is_Intrinsic_Subprogram (Entity (N))
9245 Resolve_Intrinsic_Operator (N, Typ);
9249 if Etype (Left_Opnd (N)) = Universal_Integer
9250 or else Etype (Left_Opnd (N)) = Universal_Real
9252 Check_For_Visible_Operator (N, B_Typ);
9255 -- We do the resolution using the base type, because intermediate values
9256 -- in expressions are always of the base type, not a subtype of it.
9258 Resolve (Left_Opnd (N), B_Typ);
9259 Resolve (Right_Opnd (N), Standard_Integer);
9261 -- For integer types, right argument must be in Natural range
9263 if Is_Integer_Type (Typ) then
9264 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9267 Check_Unset_Reference (Left_Opnd (N));
9268 Check_Unset_Reference (Right_Opnd (N));
9270 Set_Etype (N, B_Typ);
9271 Generate_Operator_Reference (N, B_Typ);
9273 Analyze_Dimension (N);
9275 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9276 -- Evaluate the exponentiation operator for dimensioned type
9278 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9283 -- Set overflow checking bit. Much cleverer code needed here eventually
9284 -- and perhaps the Resolve routines should be separated for the various
9285 -- arithmetic operations, since they will need different processing. ???
9287 if Nkind (N) in N_Op then
9288 if not Overflow_Checks_Suppressed (Etype (N)) then
9289 Enable_Overflow_Check (N);
9292 end Resolve_Op_Expon;
9294 --------------------
9295 -- Resolve_Op_Not --
9296 --------------------
9298 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9301 function Parent_Is_Boolean return Boolean;
9302 -- This function determines if the parent node is a boolean operator or
9303 -- operation (comparison op, membership test, or short circuit form) and
9304 -- the not in question is the left operand of this operation. Note that
9305 -- if the not is in parens, then false is returned.
9307 -----------------------
9308 -- Parent_Is_Boolean --
9309 -----------------------
9311 function Parent_Is_Boolean return Boolean is
9313 if Paren_Count (N) /= 0 then
9317 case Nkind (Parent (N)) is
9332 return Left_Opnd (Parent (N)) = N;
9338 end Parent_Is_Boolean;
9340 -- Start of processing for Resolve_Op_Not
9343 -- Predefined operations on scalar types yield the base type. On the
9344 -- other hand, logical operations on arrays yield the type of the
9345 -- arguments (and the context).
9347 if Is_Array_Type (Typ) then
9350 B_Typ := Base_Type (Typ);
9353 -- Straightforward case of incorrect arguments
9355 if not Valid_Boolean_Arg (Typ) then
9356 Error_Msg_N ("invalid operand type for operator&", N);
9357 Set_Etype (N, Any_Type);
9360 -- Special case of probable missing parens
9362 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9363 if Parent_Is_Boolean then
9365 ("operand of not must be enclosed in parentheses",
9369 ("no modular type available in this context", N);
9372 Set_Etype (N, Any_Type);
9375 -- OK resolution of NOT
9378 -- Warn if non-boolean types involved. This is a case like not a < b
9379 -- where a and b are modular, where we will get (not a) < b and most
9380 -- likely not (a < b) was intended.
9382 if Warn_On_Questionable_Missing_Parens
9383 and then not Is_Boolean_Type (Typ)
9384 and then Parent_Is_Boolean
9386 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9389 -- Warn on double negation if checking redundant constructs
9391 if Warn_On_Redundant_Constructs
9392 and then Comes_From_Source (N)
9393 and then Comes_From_Source (Right_Opnd (N))
9394 and then Root_Type (Typ) = Standard_Boolean
9395 and then Nkind (Right_Opnd (N)) = N_Op_Not
9397 Error_Msg_N ("redundant double negation?r?", N);
9400 -- Complete resolution and evaluation of NOT
9402 Resolve (Right_Opnd (N), B_Typ);
9403 Check_Unset_Reference (Right_Opnd (N));
9404 Set_Etype (N, B_Typ);
9405 Generate_Operator_Reference (N, B_Typ);
9410 -----------------------------
9411 -- Resolve_Operator_Symbol --
9412 -----------------------------
9414 -- Nothing to be done, all resolved already
9416 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9417 pragma Warnings (Off, N);
9418 pragma Warnings (Off, Typ);
9422 end Resolve_Operator_Symbol;
9424 ----------------------------------
9425 -- Resolve_Qualified_Expression --
9426 ----------------------------------
9428 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9429 pragma Warnings (Off, Typ);
9431 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9432 Expr : constant Node_Id := Expression (N);
9435 Resolve (Expr, Target_Typ);
9437 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9438 -- operation if not needed.
9440 if Restriction_Check_Required (SPARK_05)
9441 and then Is_Array_Type (Target_Typ)
9442 and then Is_Array_Type (Etype (Expr))
9443 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9444 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9446 Check_SPARK_05_Restriction
9447 ("array types should have matching static bounds", N);
9450 -- A qualified expression requires an exact match of the type, class-
9451 -- wide matching is not allowed. However, if the qualifying type is
9452 -- specific and the expression has a class-wide type, it may still be
9453 -- okay, since it can be the result of the expansion of a call to a
9454 -- dispatching function, so we also have to check class-wideness of the
9455 -- type of the expression's original node.
9457 if (Is_Class_Wide_Type (Target_Typ)
9459 (Is_Class_Wide_Type (Etype (Expr))
9460 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9461 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9463 Wrong_Type (Expr, Target_Typ);
9466 -- If the target type is unconstrained, then we reset the type of the
9467 -- result from the type of the expression. For other cases, the actual
9468 -- subtype of the expression is the target type.
9470 if Is_Composite_Type (Target_Typ)
9471 and then not Is_Constrained (Target_Typ)
9473 Set_Etype (N, Etype (Expr));
9476 Analyze_Dimension (N);
9477 Eval_Qualified_Expression (N);
9479 -- If we still have a qualified expression after the static evaluation,
9480 -- then apply a scalar range check if needed. The reason that we do this
9481 -- after the Eval call is that otherwise, the application of the range
9482 -- check may convert an illegal static expression and result in warning
9483 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9485 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9486 Apply_Scalar_Range_Check (Expr, Typ);
9489 -- Finally, check whether a predicate applies to the target type. This
9490 -- comes from AI12-0100. As for type conversions, check the enclosing
9491 -- context to prevent an infinite expansion.
9493 if Has_Predicates (Target_Typ) then
9494 if Nkind (Parent (N)) = N_Function_Call
9495 and then Present (Name (Parent (N)))
9496 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
9498 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
9502 -- In the case of a qualified expression in an allocator, the check
9503 -- is applied when expanding the allocator, so avoid redundant check.
9505 elsif Nkind (N) = N_Qualified_Expression
9506 and then Nkind (Parent (N)) /= N_Allocator
9508 Apply_Predicate_Check (N, Target_Typ);
9511 end Resolve_Qualified_Expression;
9513 ------------------------------
9514 -- Resolve_Raise_Expression --
9515 ------------------------------
9517 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9519 if Typ = Raise_Type then
9520 Error_Msg_N ("cannot find unique type for raise expression", N);
9521 Set_Etype (N, Any_Type);
9525 end Resolve_Raise_Expression;
9531 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9532 L : constant Node_Id := Low_Bound (N);
9533 H : constant Node_Id := High_Bound (N);
9535 function First_Last_Ref return Boolean;
9536 -- Returns True if N is of the form X'First .. X'Last where X is the
9537 -- same entity for both attributes.
9539 --------------------
9540 -- First_Last_Ref --
9541 --------------------
9543 function First_Last_Ref return Boolean is
9544 Lorig : constant Node_Id := Original_Node (L);
9545 Horig : constant Node_Id := Original_Node (H);
9548 if Nkind (Lorig) = N_Attribute_Reference
9549 and then Nkind (Horig) = N_Attribute_Reference
9550 and then Attribute_Name (Lorig) = Name_First
9551 and then Attribute_Name (Horig) = Name_Last
9554 PL : constant Node_Id := Prefix (Lorig);
9555 PH : constant Node_Id := Prefix (Horig);
9557 if Is_Entity_Name (PL)
9558 and then Is_Entity_Name (PH)
9559 and then Entity (PL) = Entity (PH)
9569 -- Start of processing for Resolve_Range
9576 -- Check for inappropriate range on unordered enumeration type
9578 if Bad_Unordered_Enumeration_Reference (N, Typ)
9580 -- Exclude X'First .. X'Last if X is the same entity for both
9582 and then not First_Last_Ref
9584 Error_Msg_Sloc := Sloc (Typ);
9586 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9589 Check_Unset_Reference (L);
9590 Check_Unset_Reference (H);
9592 -- We have to check the bounds for being within the base range as
9593 -- required for a non-static context. Normally this is automatic and
9594 -- done as part of evaluating expressions, but the N_Range node is an
9595 -- exception, since in GNAT we consider this node to be a subexpression,
9596 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9597 -- this, but that would put the test on the main evaluation path for
9600 Check_Non_Static_Context (L);
9601 Check_Non_Static_Context (H);
9603 -- Check for an ambiguous range over character literals. This will
9604 -- happen with a membership test involving only literals.
9606 if Typ = Any_Character then
9607 Ambiguous_Character (L);
9608 Set_Etype (N, Any_Type);
9612 -- If bounds are static, constant-fold them, so size computations are
9613 -- identical between front-end and back-end. Do not perform this
9614 -- transformation while analyzing generic units, as type information
9615 -- would be lost when reanalyzing the constant node in the instance.
9617 if Is_Discrete_Type (Typ) and then Expander_Active then
9618 if Is_OK_Static_Expression (L) then
9619 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9622 if Is_OK_Static_Expression (H) then
9623 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9628 --------------------------
9629 -- Resolve_Real_Literal --
9630 --------------------------
9632 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9633 Actual_Typ : constant Entity_Id := Etype (N);
9636 -- Special processing for fixed-point literals to make sure that the
9637 -- value is an exact multiple of small where this is required. We skip
9638 -- this for the universal real case, and also for generic types.
9640 if Is_Fixed_Point_Type (Typ)
9641 and then Typ /= Universal_Fixed
9642 and then Typ /= Any_Fixed
9643 and then not Is_Generic_Type (Typ)
9646 Val : constant Ureal := Realval (N);
9647 Cintr : constant Ureal := Val / Small_Value (Typ);
9648 Cint : constant Uint := UR_Trunc (Cintr);
9649 Den : constant Uint := Norm_Den (Cintr);
9653 -- Case of literal is not an exact multiple of the Small
9657 -- For a source program literal for a decimal fixed-point type,
9658 -- this is statically illegal (RM 4.9(36)).
9660 if Is_Decimal_Fixed_Point_Type (Typ)
9661 and then Actual_Typ = Universal_Real
9662 and then Comes_From_Source (N)
9664 Error_Msg_N ("value has extraneous low order digits", N);
9667 -- Generate a warning if literal from source
9669 if Is_OK_Static_Expression (N)
9670 and then Warn_On_Bad_Fixed_Value
9673 ("?b?static fixed-point value is not a multiple of Small!",
9677 -- Replace literal by a value that is the exact representation
9678 -- of a value of the type, i.e. a multiple of the small value,
9679 -- by truncation, since Machine_Rounds is false for all GNAT
9680 -- fixed-point types (RM 4.9(38)).
9682 Stat := Is_OK_Static_Expression (N);
9684 Make_Real_Literal (Sloc (N),
9685 Realval => Small_Value (Typ) * Cint));
9687 Set_Is_Static_Expression (N, Stat);
9690 -- In all cases, set the corresponding integer field
9692 Set_Corresponding_Integer_Value (N, Cint);
9696 -- Now replace the actual type by the expected type as usual
9699 Eval_Real_Literal (N);
9700 end Resolve_Real_Literal;
9702 -----------------------
9703 -- Resolve_Reference --
9704 -----------------------
9706 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9707 P : constant Node_Id := Prefix (N);
9710 -- Replace general access with specific type
9712 if Ekind (Etype (N)) = E_Allocator_Type then
9713 Set_Etype (N, Base_Type (Typ));
9716 Resolve (P, Designated_Type (Etype (N)));
9718 -- If we are taking the reference of a volatile entity, then treat it as
9719 -- a potential modification of this entity. This is too conservative,
9720 -- but necessary because remove side effects can cause transformations
9721 -- of normal assignments into reference sequences that otherwise fail to
9722 -- notice the modification.
9724 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9725 Note_Possible_Modification (P, Sure => False);
9727 end Resolve_Reference;
9729 --------------------------------
9730 -- Resolve_Selected_Component --
9731 --------------------------------
9733 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9735 Comp1 : Entity_Id := Empty; -- prevent junk warning
9736 P : constant Node_Id := Prefix (N);
9737 S : constant Node_Id := Selector_Name (N);
9738 T : Entity_Id := Etype (P);
9740 I1 : Interp_Index := 0; -- prevent junk warning
9745 function Init_Component return Boolean;
9746 -- Check whether this is the initialization of a component within an
9747 -- init proc (by assignment or call to another init proc). If true,
9748 -- there is no need for a discriminant check.
9750 --------------------
9751 -- Init_Component --
9752 --------------------
9754 function Init_Component return Boolean is
9756 return Inside_Init_Proc
9757 and then Nkind (Prefix (N)) = N_Identifier
9758 and then Chars (Prefix (N)) = Name_uInit
9759 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9762 -- Start of processing for Resolve_Selected_Component
9765 if Is_Overloaded (P) then
9767 -- Use the context type to select the prefix that has a selector
9768 -- of the correct name and type.
9771 Get_First_Interp (P, I, It);
9773 Search : while Present (It.Typ) loop
9774 if Is_Access_Type (It.Typ) then
9775 T := Designated_Type (It.Typ);
9780 -- Locate selected component. For a private prefix the selector
9781 -- can denote a discriminant.
9783 if Is_Record_Type (T) or else Is_Private_Type (T) then
9785 -- The visible components of a class-wide type are those of
9788 if Is_Class_Wide_Type (T) then
9792 Comp := First_Entity (T);
9793 while Present (Comp) loop
9794 if Chars (Comp) = Chars (S)
9795 and then Covers (Typ, Etype (Comp))
9804 It := Disambiguate (P, I1, I, Any_Type);
9806 if It = No_Interp then
9808 ("ambiguous prefix for selected component", N);
9815 -- There may be an implicit dereference. Retrieve
9816 -- designated record type.
9818 if Is_Access_Type (It1.Typ) then
9819 T := Designated_Type (It1.Typ);
9824 if Scope (Comp1) /= T then
9826 -- Resolution chooses the new interpretation.
9827 -- Find the component with the right name.
9829 Comp1 := First_Entity (T);
9830 while Present (Comp1)
9831 and then Chars (Comp1) /= Chars (S)
9833 Comp1 := Next_Entity (Comp1);
9842 Comp := Next_Entity (Comp);
9846 Get_Next_Interp (I, It);
9849 -- There must be a legal interpretation at this point
9851 pragma Assert (Found);
9852 Resolve (P, It1.Typ);
9854 Set_Entity_With_Checks (S, Comp1);
9857 -- Resolve prefix with its type
9862 -- Generate cross-reference. We needed to wait until full overloading
9863 -- resolution was complete to do this, since otherwise we can't tell if
9864 -- we are an lvalue or not.
9866 if May_Be_Lvalue (N) then
9867 Generate_Reference (Entity (S), S, 'm');
9869 Generate_Reference (Entity (S), S, 'r');
9872 -- If prefix is an access type, the node will be transformed into an
9873 -- explicit dereference during expansion. The type of the node is the
9874 -- designated type of that of the prefix.
9876 if Is_Access_Type (Etype (P)) then
9877 T := Designated_Type (Etype (P));
9878 Check_Fully_Declared_Prefix (T, P);
9883 -- Set flag for expander if discriminant check required on a component
9884 -- appearing within a variant.
9886 if Has_Discriminants (T)
9887 and then Ekind (Entity (S)) = E_Component
9888 and then Present (Original_Record_Component (Entity (S)))
9889 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9891 Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
9892 and then not Discriminant_Checks_Suppressed (T)
9893 and then not Init_Component
9895 Set_Do_Discriminant_Check (N);
9898 if Ekind (Entity (S)) = E_Void then
9899 Error_Msg_N ("premature use of component", S);
9902 -- If the prefix is a record conversion, this may be a renamed
9903 -- discriminant whose bounds differ from those of the original
9904 -- one, so we must ensure that a range check is performed.
9906 if Nkind (P) = N_Type_Conversion
9907 and then Ekind (Entity (S)) = E_Discriminant
9908 and then Is_Discrete_Type (Typ)
9910 Set_Etype (N, Base_Type (Typ));
9913 -- Note: No Eval processing is required, because the prefix is of a
9914 -- record type, or protected type, and neither can possibly be static.
9916 -- If the record type is atomic, and the component is non-atomic, then
9917 -- this is worth a warning, since we have a situation where the access
9918 -- to the component may cause extra read/writes of the atomic array
9919 -- object, or partial word accesses, both of which may be unexpected.
9921 if Nkind (N) = N_Selected_Component
9922 and then Is_Atomic_Ref_With_Address (N)
9923 and then not Is_Atomic (Entity (S))
9924 and then not Is_Atomic (Etype (Entity (S)))
9927 ("??access to non-atomic component of atomic record",
9930 ("\??may cause unexpected accesses to atomic object",
9934 Analyze_Dimension (N);
9935 end Resolve_Selected_Component;
9941 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9942 B_Typ : constant Entity_Id := Base_Type (Typ);
9943 L : constant Node_Id := Left_Opnd (N);
9944 R : constant Node_Id := Right_Opnd (N);
9947 -- We do the resolution using the base type, because intermediate values
9948 -- in expressions always are of the base type, not a subtype of it.
9951 Resolve (R, Standard_Natural);
9953 Check_Unset_Reference (L);
9954 Check_Unset_Reference (R);
9956 Set_Etype (N, B_Typ);
9957 Generate_Operator_Reference (N, B_Typ);
9961 ---------------------------
9962 -- Resolve_Short_Circuit --
9963 ---------------------------
9965 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9966 B_Typ : constant Entity_Id := Base_Type (Typ);
9967 L : constant Node_Id := Left_Opnd (N);
9968 R : constant Node_Id := Right_Opnd (N);
9971 -- Ensure all actions associated with the left operand (e.g.
9972 -- finalization of transient objects) are fully evaluated locally within
9973 -- an expression with actions. This is particularly helpful for coverage
9974 -- analysis. However this should not happen in generics or if option
9975 -- Minimize_Expression_With_Actions is set.
9977 if Expander_Active and not Minimize_Expression_With_Actions then
9979 Reloc_L : constant Node_Id := Relocate_Node (L);
9981 Save_Interps (Old_N => L, New_N => Reloc_L);
9984 Make_Expression_With_Actions (Sloc (L),
9985 Actions => New_List,
9986 Expression => Reloc_L));
9988 -- Set Comes_From_Source on L to preserve warnings for unset
9991 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9998 -- Check for issuing warning for always False assert/check, this happens
9999 -- when assertions are turned off, in which case the pragma Assert/Check
10000 -- was transformed into:
10002 -- if False and then <condition> then ...
10004 -- and we detect this pattern
10006 if Warn_On_Assertion_Failure
10007 and then Is_Entity_Name (R)
10008 and then Entity (R) = Standard_False
10009 and then Nkind (Parent (N)) = N_If_Statement
10010 and then Nkind (N) = N_And_Then
10011 and then Is_Entity_Name (L)
10012 and then Entity (L) = Standard_False
10015 Orig : constant Node_Id := Original_Node (Parent (N));
10018 -- Special handling of Asssert pragma
10020 if Nkind (Orig) = N_Pragma
10021 and then Pragma_Name (Orig) = Name_Assert
10024 Expr : constant Node_Id :=
10027 (First (Pragma_Argument_Associations (Orig))));
10030 -- Don't warn if original condition is explicit False,
10031 -- since obviously the failure is expected in this case.
10033 if Is_Entity_Name (Expr)
10034 and then Entity (Expr) = Standard_False
10038 -- Issue warning. We do not want the deletion of the
10039 -- IF/AND-THEN to take this message with it. We achieve this
10040 -- by making sure that the expanded code points to the Sloc
10041 -- of the expression, not the original pragma.
10044 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10045 -- The source location of the expression is not usually
10046 -- the best choice here. For example, it gets located on
10047 -- the last AND keyword in a chain of boolean expressiond
10048 -- AND'ed together. It is best to put the message on the
10049 -- first character of the assertion, which is the effect
10050 -- of the First_Node call here.
10053 ("?A?assertion would fail at run time!",
10055 (First (Pragma_Argument_Associations (Orig))));
10059 -- Similar processing for Check pragma
10061 elsif Nkind (Orig) = N_Pragma
10062 and then Pragma_Name (Orig) = Name_Check
10064 -- Don't want to warn if original condition is explicit False
10067 Expr : constant Node_Id :=
10070 (Next (First (Pragma_Argument_Associations (Orig)))));
10072 if Is_Entity_Name (Expr)
10073 and then Entity (Expr) = Standard_False
10080 -- Again use Error_Msg_F rather than Error_Msg_N, see
10081 -- comment above for an explanation of why we do this.
10084 ("?A?check would fail at run time!",
10086 (Last (Pragma_Argument_Associations (Orig))));
10093 -- Continue with processing of short circuit
10095 Check_Unset_Reference (L);
10096 Check_Unset_Reference (R);
10098 Set_Etype (N, B_Typ);
10099 Eval_Short_Circuit (N);
10100 end Resolve_Short_Circuit;
10102 -------------------
10103 -- Resolve_Slice --
10104 -------------------
10106 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10107 Drange : constant Node_Id := Discrete_Range (N);
10108 Name : constant Node_Id := Prefix (N);
10109 Array_Type : Entity_Id := Empty;
10110 Dexpr : Node_Id := Empty;
10111 Index_Type : Entity_Id;
10114 if Is_Overloaded (Name) then
10116 -- Use the context type to select the prefix that yields the correct
10121 I1 : Interp_Index := 0;
10123 P : constant Node_Id := Prefix (N);
10124 Found : Boolean := False;
10127 Get_First_Interp (P, I, It);
10128 while Present (It.Typ) loop
10129 if (Is_Array_Type (It.Typ)
10130 and then Covers (Typ, It.Typ))
10131 or else (Is_Access_Type (It.Typ)
10132 and then Is_Array_Type (Designated_Type (It.Typ))
10133 and then Covers (Typ, Designated_Type (It.Typ)))
10136 It := Disambiguate (P, I1, I, Any_Type);
10138 if It = No_Interp then
10139 Error_Msg_N ("ambiguous prefix for slicing", N);
10140 Set_Etype (N, Typ);
10144 Array_Type := It.Typ;
10149 Array_Type := It.Typ;
10154 Get_Next_Interp (I, It);
10159 Array_Type := Etype (Name);
10162 Resolve (Name, Array_Type);
10164 if Is_Access_Type (Array_Type) then
10165 Apply_Access_Check (N);
10166 Array_Type := Designated_Type (Array_Type);
10168 -- If the prefix is an access to an unconstrained array, we must use
10169 -- the actual subtype of the object to perform the index checks. The
10170 -- object denoted by the prefix is implicit in the node, so we build
10171 -- an explicit representation for it in order to compute the actual
10174 if not Is_Constrained (Array_Type) then
10175 Remove_Side_Effects (Prefix (N));
10178 Obj : constant Node_Id :=
10179 Make_Explicit_Dereference (Sloc (N),
10180 Prefix => New_Copy_Tree (Prefix (N)));
10182 Set_Etype (Obj, Array_Type);
10183 Set_Parent (Obj, Parent (N));
10184 Array_Type := Get_Actual_Subtype (Obj);
10188 elsif Is_Entity_Name (Name)
10189 or else Nkind (Name) = N_Explicit_Dereference
10190 or else (Nkind (Name) = N_Function_Call
10191 and then not Is_Constrained (Etype (Name)))
10193 Array_Type := Get_Actual_Subtype (Name);
10195 -- If the name is a selected component that depends on discriminants,
10196 -- build an actual subtype for it. This can happen only when the name
10197 -- itself is overloaded; otherwise the actual subtype is created when
10198 -- the selected component is analyzed.
10200 elsif Nkind (Name) = N_Selected_Component
10201 and then Full_Analysis
10202 and then Depends_On_Discriminant (First_Index (Array_Type))
10205 Act_Decl : constant Node_Id :=
10206 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10208 Insert_Action (N, Act_Decl);
10209 Array_Type := Defining_Identifier (Act_Decl);
10212 -- Maybe this should just be "else", instead of checking for the
10213 -- specific case of slice??? This is needed for the case where the
10214 -- prefix is an Image attribute, which gets expanded to a slice, and so
10215 -- has a constrained subtype which we want to use for the slice range
10216 -- check applied below (the range check won't get done if the
10217 -- unconstrained subtype of the 'Image is used).
10219 elsif Nkind (Name) = N_Slice then
10220 Array_Type := Etype (Name);
10223 -- Obtain the type of the array index
10225 if Ekind (Array_Type) = E_String_Literal_Subtype then
10226 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10228 Index_Type := Etype (First_Index (Array_Type));
10231 -- If name was overloaded, set slice type correctly now
10233 Set_Etype (N, Array_Type);
10235 -- Handle the generation of a range check that compares the array index
10236 -- against the discrete_range. The check is not applied to internally
10237 -- built nodes associated with the expansion of dispatch tables. Check
10238 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10241 if Tagged_Type_Expansion
10242 and then RTU_Loaded (Ada_Tags)
10243 and then Nkind (Prefix (N)) = N_Selected_Component
10244 and then Present (Entity (Selector_Name (Prefix (N))))
10245 and then Entity (Selector_Name (Prefix (N))) =
10246 RTE_Record_Component (RE_Prims_Ptr)
10250 -- The discrete_range is specified by a subtype indication. Create a
10251 -- shallow copy and inherit the type, parent and source location from
10252 -- the discrete_range. This ensures that the range check is inserted
10253 -- relative to the slice and that the runtime exception points to the
10254 -- proper construct.
10256 elsif Is_Entity_Name (Drange) then
10257 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10259 Set_Etype (Dexpr, Etype (Drange));
10260 Set_Parent (Dexpr, Parent (Drange));
10261 Set_Sloc (Dexpr, Sloc (Drange));
10263 -- The discrete_range is a regular range. Resolve the bounds and remove
10264 -- their side effects.
10267 Resolve (Drange, Base_Type (Index_Type));
10269 if Nkind (Drange) = N_Range then
10270 Force_Evaluation (Low_Bound (Drange));
10271 Force_Evaluation (High_Bound (Drange));
10277 if Present (Dexpr) then
10278 Apply_Range_Check (Dexpr, Index_Type);
10281 Set_Slice_Subtype (N);
10283 -- Check bad use of type with predicates
10289 if Nkind (Drange) = N_Subtype_Indication
10290 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10292 Subt := Entity (Subtype_Mark (Drange));
10294 Subt := Etype (Drange);
10297 if Has_Predicates (Subt) then
10298 Bad_Predicated_Subtype_Use
10299 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10303 -- Otherwise here is where we check suspicious indexes
10305 if Nkind (Drange) = N_Range then
10306 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10307 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10310 Analyze_Dimension (N);
10314 ----------------------------
10315 -- Resolve_String_Literal --
10316 ----------------------------
10318 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10319 C_Typ : constant Entity_Id := Component_Type (Typ);
10320 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10321 Loc : constant Source_Ptr := Sloc (N);
10322 Str : constant String_Id := Strval (N);
10323 Strlen : constant Nat := String_Length (Str);
10324 Subtype_Id : Entity_Id;
10325 Need_Check : Boolean;
10328 -- For a string appearing in a concatenation, defer creation of the
10329 -- string_literal_subtype until the end of the resolution of the
10330 -- concatenation, because the literal may be constant-folded away. This
10331 -- is a useful optimization for long concatenation expressions.
10333 -- If the string is an aggregate built for a single character (which
10334 -- happens in a non-static context) or a is null string to which special
10335 -- checks may apply, we build the subtype. Wide strings must also get a
10336 -- string subtype if they come from a one character aggregate. Strings
10337 -- generated by attributes might be static, but it is often hard to
10338 -- determine whether the enclosing context is static, so we generate
10339 -- subtypes for them as well, thus losing some rarer optimizations ???
10340 -- Same for strings that come from a static conversion.
10343 (Strlen = 0 and then Typ /= Standard_String)
10344 or else Nkind (Parent (N)) /= N_Op_Concat
10345 or else (N /= Left_Opnd (Parent (N))
10346 and then N /= Right_Opnd (Parent (N)))
10347 or else ((Typ = Standard_Wide_String
10348 or else Typ = Standard_Wide_Wide_String)
10349 and then Nkind (Original_Node (N)) /= N_String_Literal);
10351 -- If the resolving type is itself a string literal subtype, we can just
10352 -- reuse it, since there is no point in creating another.
10354 if Ekind (Typ) = E_String_Literal_Subtype then
10357 elsif Nkind (Parent (N)) = N_Op_Concat
10358 and then not Need_Check
10359 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10360 N_Attribute_Reference,
10361 N_Qualified_Expression,
10366 -- Do not generate a string literal subtype for the default expression
10367 -- of a formal parameter in GNATprove mode. This is because the string
10368 -- subtype is associated with the freezing actions of the subprogram,
10369 -- however freezing is disabled in GNATprove mode and as a result the
10370 -- subtype is unavailable.
10372 elsif GNATprove_Mode
10373 and then Nkind (Parent (N)) = N_Parameter_Specification
10377 -- Otherwise we must create a string literal subtype. Note that the
10378 -- whole idea of string literal subtypes is simply to avoid the need
10379 -- for building a full fledged array subtype for each literal.
10382 Set_String_Literal_Subtype (N, Typ);
10383 Subtype_Id := Etype (N);
10386 if Nkind (Parent (N)) /= N_Op_Concat
10389 Set_Etype (N, Subtype_Id);
10390 Eval_String_Literal (N);
10393 if Is_Limited_Composite (Typ)
10394 or else Is_Private_Composite (Typ)
10396 Error_Msg_N ("string literal not available for private array", N);
10397 Set_Etype (N, Any_Type);
10401 -- The validity of a null string has been checked in the call to
10402 -- Eval_String_Literal.
10407 -- Always accept string literal with component type Any_Character, which
10408 -- occurs in error situations and in comparisons of literals, both of
10409 -- which should accept all literals.
10411 elsif R_Typ = Any_Character then
10414 -- If the type is bit-packed, then we always transform the string
10415 -- literal into a full fledged aggregate.
10417 elsif Is_Bit_Packed_Array (Typ) then
10420 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10423 -- For Standard.Wide_Wide_String, or any other type whose component
10424 -- type is Standard.Wide_Wide_Character, we know that all the
10425 -- characters in the string must be acceptable, since the parser
10426 -- accepted the characters as valid character literals.
10428 if R_Typ = Standard_Wide_Wide_Character then
10431 -- For the case of Standard.String, or any other type whose component
10432 -- type is Standard.Character, we must make sure that there are no
10433 -- wide characters in the string, i.e. that it is entirely composed
10434 -- of characters in range of type Character.
10436 -- If the string literal is the result of a static concatenation, the
10437 -- test has already been performed on the components, and need not be
10440 elsif R_Typ = Standard_Character
10441 and then Nkind (Original_Node (N)) /= N_Op_Concat
10443 for J in 1 .. Strlen loop
10444 if not In_Character_Range (Get_String_Char (Str, J)) then
10446 -- If we are out of range, post error. This is one of the
10447 -- very few places that we place the flag in the middle of
10448 -- a token, right under the offending wide character. Not
10449 -- quite clear if this is right wrt wide character encoding
10450 -- sequences, but it's only an error message.
10453 ("literal out of range of type Standard.Character",
10454 Source_Ptr (Int (Loc) + J));
10459 -- For the case of Standard.Wide_String, or any other type whose
10460 -- component type is Standard.Wide_Character, we must make sure that
10461 -- there are no wide characters in the string, i.e. that it is
10462 -- entirely composed of characters in range of type Wide_Character.
10464 -- If the string literal is the result of a static concatenation,
10465 -- the test has already been performed on the components, and need
10466 -- not be repeated.
10468 elsif R_Typ = Standard_Wide_Character
10469 and then Nkind (Original_Node (N)) /= N_Op_Concat
10471 for J in 1 .. Strlen loop
10472 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10474 -- If we are out of range, post error. This is one of the
10475 -- very few places that we place the flag in the middle of
10476 -- a token, right under the offending wide character.
10478 -- This is not quite right, because characters in general
10479 -- will take more than one character position ???
10482 ("literal out of range of type Standard.Wide_Character",
10483 Source_Ptr (Int (Loc) + J));
10488 -- If the root type is not a standard character, then we will convert
10489 -- the string into an aggregate and will let the aggregate code do
10490 -- the checking. Standard Wide_Wide_Character is also OK here.
10496 -- See if the component type of the array corresponding to the string
10497 -- has compile time known bounds. If yes we can directly check
10498 -- whether the evaluation of the string will raise constraint error.
10499 -- Otherwise we need to transform the string literal into the
10500 -- corresponding character aggregate and let the aggregate code do
10503 if Is_Standard_Character_Type (R_Typ) then
10505 -- Check for the case of full range, where we are definitely OK
10507 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10511 -- Here the range is not the complete base type range, so check
10514 Comp_Typ_Lo : constant Node_Id :=
10515 Type_Low_Bound (Component_Type (Typ));
10516 Comp_Typ_Hi : constant Node_Id :=
10517 Type_High_Bound (Component_Type (Typ));
10522 if Compile_Time_Known_Value (Comp_Typ_Lo)
10523 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10525 for J in 1 .. Strlen loop
10526 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10528 if Char_Val < Expr_Value (Comp_Typ_Lo)
10529 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10531 Apply_Compile_Time_Constraint_Error
10532 (N, "character out of range??",
10533 CE_Range_Check_Failed,
10534 Loc => Source_Ptr (Int (Loc) + J));
10544 -- If we got here we meed to transform the string literal into the
10545 -- equivalent qualified positional array aggregate. This is rather
10546 -- heavy artillery for this situation, but it is hard work to avoid.
10549 Lits : constant List_Id := New_List;
10550 P : Source_Ptr := Loc + 1;
10554 -- Build the character literals, we give them source locations that
10555 -- correspond to the string positions, which is a bit tricky given
10556 -- the possible presence of wide character escape sequences.
10558 for J in 1 .. Strlen loop
10559 C := Get_String_Char (Str, J);
10560 Set_Character_Literal_Name (C);
10563 Make_Character_Literal (P,
10564 Chars => Name_Find,
10565 Char_Literal_Value => UI_From_CC (C)));
10567 if In_Character_Range (C) then
10570 -- Should we have a call to Skip_Wide here ???
10579 Make_Qualified_Expression (Loc,
10580 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10582 Make_Aggregate (Loc, Expressions => Lits)));
10584 Analyze_And_Resolve (N, Typ);
10586 end Resolve_String_Literal;
10588 -----------------------------
10589 -- Resolve_Type_Conversion --
10590 -----------------------------
10592 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10593 Conv_OK : constant Boolean := Conversion_OK (N);
10594 Operand : constant Node_Id := Expression (N);
10595 Operand_Typ : constant Entity_Id := Etype (Operand);
10596 Target_Typ : constant Entity_Id := Etype (N);
10601 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10602 -- Set to False to suppress cases where we want to suppress the test
10603 -- for redundancy to avoid possible false positives on this warning.
10607 and then not Valid_Conversion (N, Target_Typ, Operand)
10612 -- If the Operand Etype is Universal_Fixed, then the conversion is
10613 -- never redundant. We need this check because by the time we have
10614 -- finished the rather complex transformation, the conversion looks
10615 -- redundant when it is not.
10617 if Operand_Typ = Universal_Fixed then
10618 Test_Redundant := False;
10620 -- If the operand is marked as Any_Fixed, then special processing is
10621 -- required. This is also a case where we suppress the test for a
10622 -- redundant conversion, since most certainly it is not redundant.
10624 elsif Operand_Typ = Any_Fixed then
10625 Test_Redundant := False;
10627 -- Mixed-mode operation involving a literal. Context must be a fixed
10628 -- type which is applied to the literal subsequently.
10630 if Is_Fixed_Point_Type (Typ) then
10631 Set_Etype (Operand, Universal_Real);
10633 elsif Is_Numeric_Type (Typ)
10634 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10635 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10637 Etype (Left_Opnd (Operand)) = Universal_Real)
10639 -- Return if expression is ambiguous
10641 if Unique_Fixed_Point_Type (N) = Any_Type then
10644 -- If nothing else, the available fixed type is Duration
10647 Set_Etype (Operand, Standard_Duration);
10650 -- Resolve the real operand with largest available precision
10652 if Etype (Right_Opnd (Operand)) = Universal_Real then
10653 Rop := New_Copy_Tree (Right_Opnd (Operand));
10655 Rop := New_Copy_Tree (Left_Opnd (Operand));
10658 Resolve (Rop, Universal_Real);
10660 -- If the operand is a literal (it could be a non-static and
10661 -- illegal exponentiation) check whether the use of Duration
10662 -- is potentially inaccurate.
10664 if Nkind (Rop) = N_Real_Literal
10665 and then Realval (Rop) /= Ureal_0
10666 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10669 ("??universal real operand can only "
10670 & "be interpreted as Duration!", Rop);
10672 ("\??precision will be lost in the conversion!", Rop);
10675 elsif Is_Numeric_Type (Typ)
10676 and then Nkind (Operand) in N_Op
10677 and then Unique_Fixed_Point_Type (N) /= Any_Type
10679 Set_Etype (Operand, Standard_Duration);
10682 Error_Msg_N ("invalid context for mixed mode operation", N);
10683 Set_Etype (Operand, Any_Type);
10690 -- In SPARK, a type conversion between array types should be restricted
10691 -- to types which have matching static bounds.
10693 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10694 -- operation if not needed.
10696 if Restriction_Check_Required (SPARK_05)
10697 and then Is_Array_Type (Target_Typ)
10698 and then Is_Array_Type (Operand_Typ)
10699 and then Operand_Typ /= Any_Composite -- or else Operand in error
10700 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10702 Check_SPARK_05_Restriction
10703 ("array types should have matching static bounds", N);
10706 -- In formal mode, the operand of an ancestor type conversion must be an
10707 -- object (not an expression).
10709 if Is_Tagged_Type (Target_Typ)
10710 and then not Is_Class_Wide_Type (Target_Typ)
10711 and then Is_Tagged_Type (Operand_Typ)
10712 and then not Is_Class_Wide_Type (Operand_Typ)
10713 and then Is_Ancestor (Target_Typ, Operand_Typ)
10714 and then not Is_SPARK_05_Object_Reference (Operand)
10716 Check_SPARK_05_Restriction ("object required", Operand);
10719 Analyze_Dimension (N);
10721 -- Note: we do the Eval_Type_Conversion call before applying the
10722 -- required checks for a subtype conversion. This is important, since
10723 -- both are prepared under certain circumstances to change the type
10724 -- conversion to a constraint error node, but in the case of
10725 -- Eval_Type_Conversion this may reflect an illegality in the static
10726 -- case, and we would miss the illegality (getting only a warning
10727 -- message), if we applied the type conversion checks first.
10729 Eval_Type_Conversion (N);
10731 -- Even when evaluation is not possible, we may be able to simplify the
10732 -- conversion or its expression. This needs to be done before applying
10733 -- checks, since otherwise the checks may use the original expression
10734 -- and defeat the simplifications. This is specifically the case for
10735 -- elimination of the floating-point Truncation attribute in
10736 -- float-to-int conversions.
10738 Simplify_Type_Conversion (N);
10740 -- If after evaluation we still have a type conversion, then we may need
10741 -- to apply checks required for a subtype conversion.
10743 -- Skip these type conversion checks if universal fixed operands
10744 -- operands involved, since range checks are handled separately for
10745 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10747 if Nkind (N) = N_Type_Conversion
10748 and then not Is_Generic_Type (Root_Type (Target_Typ))
10749 and then Target_Typ /= Universal_Fixed
10750 and then Operand_Typ /= Universal_Fixed
10752 Apply_Type_Conversion_Checks (N);
10755 -- Issue warning for conversion of simple object to its own type. We
10756 -- have to test the original nodes, since they may have been rewritten
10757 -- by various optimizations.
10759 Orig_N := Original_Node (N);
10761 -- Here we test for a redundant conversion if the warning mode is
10762 -- active (and was not locally reset), and we have a type conversion
10763 -- from source not appearing in a generic instance.
10766 and then Nkind (Orig_N) = N_Type_Conversion
10767 and then Comes_From_Source (Orig_N)
10768 and then not In_Instance
10770 Orig_N := Original_Node (Expression (Orig_N));
10771 Orig_T := Target_Typ;
10773 -- If the node is part of a larger expression, the Target_Type
10774 -- may not be the original type of the node if the context is a
10775 -- condition. Recover original type to see if conversion is needed.
10777 if Is_Boolean_Type (Orig_T)
10778 and then Nkind (Parent (N)) in N_Op
10780 Orig_T := Etype (Parent (N));
10783 -- If we have an entity name, then give the warning if the entity
10784 -- is the right type, or if it is a loop parameter covered by the
10785 -- original type (that's needed because loop parameters have an
10786 -- odd subtype coming from the bounds).
10788 if (Is_Entity_Name (Orig_N)
10790 (Etype (Entity (Orig_N)) = Orig_T
10792 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10793 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10795 -- If not an entity, then type of expression must match
10797 or else Etype (Orig_N) = Orig_T
10799 -- One more check, do not give warning if the analyzed conversion
10800 -- has an expression with non-static bounds, and the bounds of the
10801 -- target are static. This avoids junk warnings in cases where the
10802 -- conversion is necessary to establish staticness, for example in
10803 -- a case statement.
10805 if not Is_OK_Static_Subtype (Operand_Typ)
10806 and then Is_OK_Static_Subtype (Target_Typ)
10810 -- Finally, if this type conversion occurs in a context requiring
10811 -- a prefix, and the expression is a qualified expression then the
10812 -- type conversion is not redundant, since a qualified expression
10813 -- is not a prefix, whereas a type conversion is. For example, "X
10814 -- := T'(Funx(...)).Y;" is illegal because a selected component
10815 -- requires a prefix, but a type conversion makes it legal: "X :=
10816 -- T(T'(Funx(...))).Y;"
10818 -- In Ada 2012, a qualified expression is a name, so this idiom is
10819 -- no longer needed, but we still suppress the warning because it
10820 -- seems unfriendly for warnings to pop up when you switch to the
10821 -- newer language version.
10823 elsif Nkind (Orig_N) = N_Qualified_Expression
10824 and then Nkind_In (Parent (N), N_Attribute_Reference,
10825 N_Indexed_Component,
10826 N_Selected_Component,
10828 N_Explicit_Dereference)
10832 -- Never warn on conversion to Long_Long_Integer'Base since
10833 -- that is most likely an artifact of the extended overflow
10834 -- checking and comes from complex expanded code.
10836 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10839 -- Here we give the redundant conversion warning. If it is an
10840 -- entity, give the name of the entity in the message. If not,
10841 -- just mention the expression.
10843 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10846 if Is_Entity_Name (Orig_N) then
10847 Error_Msg_Node_2 := Orig_T;
10848 Error_Msg_NE -- CODEFIX
10849 ("??redundant conversion, & is of type &!",
10850 N, Entity (Orig_N));
10853 ("??redundant conversion, expression is of type&!",
10860 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10861 -- No need to perform any interface conversion if the type of the
10862 -- expression coincides with the target type.
10864 if Ada_Version >= Ada_2005
10865 and then Expander_Active
10866 and then Operand_Typ /= Target_Typ
10869 Opnd : Entity_Id := Operand_Typ;
10870 Target : Entity_Id := Target_Typ;
10873 -- If the type of the operand is a limited view, use nonlimited
10874 -- view when available. If it is a class-wide type, recover the
10875 -- class-wide type of the nonlimited view.
10877 if From_Limited_With (Opnd)
10878 and then Has_Non_Limited_View (Opnd)
10880 Opnd := Non_Limited_View (Opnd);
10881 Set_Etype (Expression (N), Opnd);
10884 if Is_Access_Type (Opnd) then
10885 Opnd := Designated_Type (Opnd);
10888 if Is_Access_Type (Target_Typ) then
10889 Target := Designated_Type (Target);
10892 if Opnd = Target then
10895 -- Conversion from interface type
10897 elsif Is_Interface (Opnd) then
10899 -- Ada 2005 (AI-217): Handle entities from limited views
10901 if From_Limited_With (Opnd) then
10902 Error_Msg_Qual_Level := 99;
10903 Error_Msg_NE -- CODEFIX
10904 ("missing WITH clause on package &", N,
10905 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10907 ("type conversions require visibility of the full view",
10910 elsif From_Limited_With (Target)
10912 (Is_Access_Type (Target_Typ)
10913 and then Present (Non_Limited_View (Etype (Target))))
10915 Error_Msg_Qual_Level := 99;
10916 Error_Msg_NE -- CODEFIX
10917 ("missing WITH clause on package &", N,
10918 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10920 ("type conversions require visibility of the full view",
10924 Expand_Interface_Conversion (N);
10927 -- Conversion to interface type
10929 elsif Is_Interface (Target) then
10933 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10934 Opnd := Etype (Opnd);
10937 if Is_Class_Wide_Type (Opnd)
10938 or else Interface_Present_In_Ancestor
10942 Expand_Interface_Conversion (N);
10944 Error_Msg_Name_1 := Chars (Etype (Target));
10945 Error_Msg_Name_2 := Chars (Opnd);
10947 ("wrong interface conversion (% is not a progenitor "
10954 -- Ada 2012: if target type has predicates, the result requires a
10955 -- predicate check. If the context is a call to another predicate
10956 -- check we must prevent infinite recursion.
10958 if Has_Predicates (Target_Typ) then
10959 if Nkind (Parent (N)) = N_Function_Call
10960 and then Present (Name (Parent (N)))
10961 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10963 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10968 Apply_Predicate_Check (N, Target_Typ);
10972 -- If at this stage we have a real to integer conversion, make sure
10973 -- that the Do_Range_Check flag is set, because such conversions in
10974 -- general need a range check. We only need this if expansion is off
10975 -- or we are in GNATProve mode.
10977 if Nkind (N) = N_Type_Conversion
10978 and then (GNATprove_Mode or not Expander_Active)
10979 and then Is_Integer_Type (Target_Typ)
10980 and then Is_Real_Type (Operand_Typ)
10982 Set_Do_Range_Check (Operand);
10985 -- Generating C code a type conversion of an access to constrained
10986 -- array type to access to unconstrained array type involves building
10987 -- a fat pointer which in general cannot be generated on the fly. We
10988 -- remove side effects in order to store the result of the conversion
10989 -- into a temporary.
10992 and then Nkind (N) = N_Type_Conversion
10993 and then Nkind (Parent (N)) /= N_Object_Declaration
10994 and then Is_Access_Type (Etype (N))
10995 and then Is_Array_Type (Designated_Type (Etype (N)))
10996 and then not Is_Constrained (Designated_Type (Etype (N)))
10997 and then Is_Constrained (Designated_Type (Etype (Expression (N))))
10999 Remove_Side_Effects (N);
11001 end Resolve_Type_Conversion;
11003 ----------------------
11004 -- Resolve_Unary_Op --
11005 ----------------------
11007 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
11008 B_Typ : constant Entity_Id := Base_Type (Typ);
11009 R : constant Node_Id := Right_Opnd (N);
11015 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
11016 Error_Msg_Name_1 := Chars (Typ);
11017 Check_SPARK_05_Restriction
11018 ("unary operator not defined for modular type%", N);
11021 -- Deal with intrinsic unary operators
11023 if Comes_From_Source (N)
11024 and then Ekind (Entity (N)) = E_Function
11025 and then Is_Imported (Entity (N))
11026 and then Is_Intrinsic_Subprogram (Entity (N))
11028 Resolve_Intrinsic_Unary_Operator (N, Typ);
11032 -- Deal with universal cases
11034 if Etype (R) = Universal_Integer
11036 Etype (R) = Universal_Real
11038 Check_For_Visible_Operator (N, B_Typ);
11041 Set_Etype (N, B_Typ);
11042 Resolve (R, B_Typ);
11044 -- Generate warning for expressions like abs (x mod 2)
11046 if Warn_On_Redundant_Constructs
11047 and then Nkind (N) = N_Op_Abs
11049 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
11051 if OK and then Hi >= Lo and then Lo >= 0 then
11052 Error_Msg_N -- CODEFIX
11053 ("?r?abs applied to known non-negative value has no effect", N);
11057 -- Deal with reference generation
11059 Check_Unset_Reference (R);
11060 Generate_Operator_Reference (N, B_Typ);
11061 Analyze_Dimension (N);
11064 -- Set overflow checking bit. Much cleverer code needed here eventually
11065 -- and perhaps the Resolve routines should be separated for the various
11066 -- arithmetic operations, since they will need different processing ???
11068 if Nkind (N) in N_Op then
11069 if not Overflow_Checks_Suppressed (Etype (N)) then
11070 Enable_Overflow_Check (N);
11074 -- Generate warning for expressions like -5 mod 3 for integers. No need
11075 -- to worry in the floating-point case, since parens do not affect the
11076 -- result so there is no point in giving in a warning.
11079 Norig : constant Node_Id := Original_Node (N);
11088 if Warn_On_Questionable_Missing_Parens
11089 and then Comes_From_Source (Norig)
11090 and then Is_Integer_Type (Typ)
11091 and then Nkind (Norig) = N_Op_Minus
11093 Rorig := Original_Node (Right_Opnd (Norig));
11095 -- We are looking for cases where the right operand is not
11096 -- parenthesized, and is a binary operator, multiply, divide, or
11097 -- mod. These are the cases where the grouping can affect results.
11099 if Paren_Count (Rorig) = 0
11100 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11102 -- For mod, we always give the warning, since the value is
11103 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11104 -- -(5 mod 315)). But for the other cases, the only concern is
11105 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11106 -- overflows, but (-2) * 64 does not). So we try to give the
11107 -- message only when overflow is possible.
11109 if Nkind (Rorig) /= N_Op_Mod
11110 and then Compile_Time_Known_Value (R)
11112 Val := Expr_Value (R);
11114 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11115 HB := Expr_Value (Type_High_Bound (Typ));
11117 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11120 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11121 LB := Expr_Value (Type_Low_Bound (Typ));
11123 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11126 -- Note that the test below is deliberately excluding the
11127 -- largest negative number, since that is a potentially
11128 -- troublesome case (e.g. -2 * x, where the result is the
11129 -- largest negative integer has an overflow with 2 * x).
11131 if Val > LB and then Val <= HB then
11136 -- For the multiplication case, the only case we have to worry
11137 -- about is when (-a)*b is exactly the largest negative number
11138 -- so that -(a*b) can cause overflow. This can only happen if
11139 -- a is a power of 2, and more generally if any operand is a
11140 -- constant that is not a power of 2, then the parentheses
11141 -- cannot affect whether overflow occurs. We only bother to
11142 -- test the left most operand
11144 -- Loop looking at left operands for one that has known value
11147 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11148 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11149 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11151 -- Operand value of 0 or 1 skips warning
11156 -- Otherwise check power of 2, if power of 2, warn, if
11157 -- anything else, skip warning.
11160 while Lval /= 2 loop
11161 if Lval mod 2 = 1 then
11172 -- Keep looking at left operands
11174 Opnd := Left_Opnd (Opnd);
11175 end loop Opnd_Loop;
11177 -- For rem or "/" we can only have a problematic situation
11178 -- if the divisor has a value of minus one or one. Otherwise
11179 -- overflow is impossible (divisor > 1) or we have a case of
11180 -- division by zero in any case.
11182 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11183 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11184 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11189 -- If we fall through warning should be issued
11191 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11194 ("??unary minus expression should be parenthesized here!", N);
11198 end Resolve_Unary_Op;
11200 ----------------------------------
11201 -- Resolve_Unchecked_Expression --
11202 ----------------------------------
11204 procedure Resolve_Unchecked_Expression
11209 Resolve (Expression (N), Typ, Suppress => All_Checks);
11210 Set_Etype (N, Typ);
11211 end Resolve_Unchecked_Expression;
11213 ---------------------------------------
11214 -- Resolve_Unchecked_Type_Conversion --
11215 ---------------------------------------
11217 procedure Resolve_Unchecked_Type_Conversion
11221 pragma Warnings (Off, Typ);
11223 Operand : constant Node_Id := Expression (N);
11224 Opnd_Type : constant Entity_Id := Etype (Operand);
11227 -- Resolve operand using its own type
11229 Resolve (Operand, Opnd_Type);
11231 -- In an inlined context, the unchecked conversion may be applied
11232 -- to a literal, in which case its type is the type of the context.
11233 -- (In other contexts conversions cannot apply to literals).
11236 and then (Opnd_Type = Any_Character or else
11237 Opnd_Type = Any_Integer or else
11238 Opnd_Type = Any_Real)
11240 Set_Etype (Operand, Typ);
11243 Analyze_Dimension (N);
11244 Eval_Unchecked_Conversion (N);
11245 end Resolve_Unchecked_Type_Conversion;
11247 ------------------------------
11248 -- Rewrite_Operator_As_Call --
11249 ------------------------------
11251 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11252 Loc : constant Source_Ptr := Sloc (N);
11253 Actuals : constant List_Id := New_List;
11257 if Nkind (N) in N_Binary_Op then
11258 Append (Left_Opnd (N), Actuals);
11261 Append (Right_Opnd (N), Actuals);
11264 Make_Function_Call (Sloc => Loc,
11265 Name => New_Occurrence_Of (Nam, Loc),
11266 Parameter_Associations => Actuals);
11268 Preserve_Comes_From_Source (New_N, N);
11269 Preserve_Comes_From_Source (Name (New_N), N);
11270 Rewrite (N, New_N);
11271 Set_Etype (N, Etype (Nam));
11272 end Rewrite_Operator_As_Call;
11274 ------------------------------
11275 -- Rewrite_Renamed_Operator --
11276 ------------------------------
11278 procedure Rewrite_Renamed_Operator
11283 Nam : constant Name_Id := Chars (Op);
11284 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11288 -- Do not perform this transformation within a pre/postcondition,
11289 -- because the expression will be re-analyzed, and the transformation
11290 -- might affect the visibility of the operator, e.g. in an instance.
11291 -- Note that fully analyzed and expanded pre/postconditions appear as
11292 -- pragma Check equivalents.
11294 if In_Pre_Post_Condition (N) then
11298 -- Rewrite the operator node using the real operator, not its renaming.
11299 -- Exclude user-defined intrinsic operations of the same name, which are
11300 -- treated separately and rewritten as calls.
11302 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11303 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11304 Set_Chars (Op_Node, Nam);
11305 Set_Etype (Op_Node, Etype (N));
11306 Set_Entity (Op_Node, Op);
11307 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11309 -- Indicate that both the original entity and its renaming are
11310 -- referenced at this point.
11312 Generate_Reference (Entity (N), N);
11313 Generate_Reference (Op, N);
11316 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11319 Rewrite (N, Op_Node);
11321 -- If the context type is private, add the appropriate conversions so
11322 -- that the operator is applied to the full view. This is done in the
11323 -- routines that resolve intrinsic operators.
11325 if Is_Intrinsic_Subprogram (Op) and then Is_Private_Type (Typ) then
11327 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11328 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11329 Resolve_Intrinsic_Operator (N, Typ);
11331 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11332 Resolve_Intrinsic_Unary_Operator (N, Typ);
11339 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11341 -- Operator renames a user-defined operator of the same name. Use the
11342 -- original operator in the node, which is the one Gigi knows about.
11344 Set_Entity (N, Op);
11345 Set_Is_Overloaded (N, False);
11347 end Rewrite_Renamed_Operator;
11349 -----------------------
11350 -- Set_Slice_Subtype --
11351 -----------------------
11353 -- Build an implicit subtype declaration to represent the type delivered by
11354 -- the slice. This is an abbreviated version of an array subtype. We define
11355 -- an index subtype for the slice, using either the subtype name or the
11356 -- discrete range of the slice. To be consistent with index usage elsewhere
11357 -- we create a list header to hold the single index. This list is not
11358 -- otherwise attached to the syntax tree.
11360 procedure Set_Slice_Subtype (N : Node_Id) is
11361 Loc : constant Source_Ptr := Sloc (N);
11362 Index_List : constant List_Id := New_List;
11364 Index_Subtype : Entity_Id;
11365 Index_Type : Entity_Id;
11366 Slice_Subtype : Entity_Id;
11367 Drange : constant Node_Id := Discrete_Range (N);
11370 Index_Type := Base_Type (Etype (Drange));
11372 if Is_Entity_Name (Drange) then
11373 Index_Subtype := Entity (Drange);
11376 -- We force the evaluation of a range. This is definitely needed in
11377 -- the renamed case, and seems safer to do unconditionally. Note in
11378 -- any case that since we will create and insert an Itype referring
11379 -- to this range, we must make sure any side effect removal actions
11380 -- are inserted before the Itype definition.
11382 if Nkind (Drange) = N_Range then
11383 Force_Evaluation (Low_Bound (Drange));
11384 Force_Evaluation (High_Bound (Drange));
11386 -- If the discrete range is given by a subtype indication, the
11387 -- type of the slice is the base of the subtype mark.
11389 elsif Nkind (Drange) = N_Subtype_Indication then
11391 R : constant Node_Id := Range_Expression (Constraint (Drange));
11393 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11394 Force_Evaluation (Low_Bound (R));
11395 Force_Evaluation (High_Bound (R));
11399 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11401 -- Take a new copy of Drange (where bounds have been rewritten to
11402 -- reference side-effect-free names). Using a separate tree ensures
11403 -- that further expansion (e.g. while rewriting a slice assignment
11404 -- into a FOR loop) does not attempt to remove side effects on the
11405 -- bounds again (which would cause the bounds in the index subtype
11406 -- definition to refer to temporaries before they are defined) (the
11407 -- reason is that some names are considered side effect free here
11408 -- for the subtype, but not in the context of a loop iteration
11411 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11412 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11413 Set_Etype (Index_Subtype, Index_Type);
11414 Set_Size_Info (Index_Subtype, Index_Type);
11415 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11418 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11420 Index := New_Occurrence_Of (Index_Subtype, Loc);
11421 Set_Etype (Index, Index_Subtype);
11422 Append (Index, Index_List);
11424 Set_First_Index (Slice_Subtype, Index);
11425 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11426 Set_Is_Constrained (Slice_Subtype, True);
11428 Check_Compile_Time_Size (Slice_Subtype);
11430 -- The Etype of the existing Slice node is reset to this slice subtype.
11431 -- Its bounds are obtained from its first index.
11433 Set_Etype (N, Slice_Subtype);
11435 -- For packed slice subtypes, freeze immediately (except in the case of
11436 -- being in a "spec expression" where we never freeze when we first see
11437 -- the expression).
11439 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11440 Freeze_Itype (Slice_Subtype, N);
11442 -- For all other cases insert an itype reference in the slice's actions
11443 -- so that the itype is frozen at the proper place in the tree (i.e. at
11444 -- the point where actions for the slice are analyzed). Note that this
11445 -- is different from freezing the itype immediately, which might be
11446 -- premature (e.g. if the slice is within a transient scope). This needs
11447 -- to be done only if expansion is enabled.
11449 elsif Expander_Active then
11450 Ensure_Defined (Typ => Slice_Subtype, N => N);
11452 end Set_Slice_Subtype;
11454 --------------------------------
11455 -- Set_String_Literal_Subtype --
11456 --------------------------------
11458 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11459 Loc : constant Source_Ptr := Sloc (N);
11460 Low_Bound : constant Node_Id :=
11461 Type_Low_Bound (Etype (First_Index (Typ)));
11462 Subtype_Id : Entity_Id;
11465 if Nkind (N) /= N_String_Literal then
11469 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11470 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11471 (String_Length (Strval (N))));
11472 Set_Etype (Subtype_Id, Base_Type (Typ));
11473 Set_Is_Constrained (Subtype_Id);
11474 Set_Etype (N, Subtype_Id);
11476 -- The low bound is set from the low bound of the corresponding index
11477 -- type. Note that we do not store the high bound in the string literal
11478 -- subtype, but it can be deduced if necessary from the length and the
11481 if Is_OK_Static_Expression (Low_Bound) then
11482 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11484 -- If the lower bound is not static we create a range for the string
11485 -- literal, using the index type and the known length of the literal.
11486 -- The index type is not necessarily Positive, so the upper bound is
11487 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11491 Index_List : constant List_Id := New_List;
11492 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11493 High_Bound : constant Node_Id :=
11494 Make_Attribute_Reference (Loc,
11495 Attribute_Name => Name_Val,
11497 New_Occurrence_Of (Index_Type, Loc),
11498 Expressions => New_List (
11501 Make_Attribute_Reference (Loc,
11502 Attribute_Name => Name_Pos,
11504 New_Occurrence_Of (Index_Type, Loc),
11506 New_List (New_Copy_Tree (Low_Bound))),
11508 Make_Integer_Literal (Loc,
11509 String_Length (Strval (N)) - 1))));
11511 Array_Subtype : Entity_Id;
11514 Index_Subtype : Entity_Id;
11517 if Is_Integer_Type (Index_Type) then
11518 Set_String_Literal_Low_Bound
11519 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11522 -- If the index type is an enumeration type, build bounds
11523 -- expression with attributes.
11525 Set_String_Literal_Low_Bound
11527 Make_Attribute_Reference (Loc,
11528 Attribute_Name => Name_First,
11530 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11531 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11534 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11536 -- Build bona fide subtype for the string, and wrap it in an
11537 -- unchecked conversion, because the backend expects the
11538 -- String_Literal_Subtype to have a static lower bound.
11541 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11542 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11543 Set_Scalar_Range (Index_Subtype, Drange);
11544 Set_Parent (Drange, N);
11545 Analyze_And_Resolve (Drange, Index_Type);
11547 -- In the context, the Index_Type may already have a constraint,
11548 -- so use common base type on string subtype. The base type may
11549 -- be used when generating attributes of the string, for example
11550 -- in the context of a slice assignment.
11552 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11553 Set_Size_Info (Index_Subtype, Index_Type);
11554 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11556 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11558 Index := New_Occurrence_Of (Index_Subtype, Loc);
11559 Set_Etype (Index, Index_Subtype);
11560 Append (Index, Index_List);
11562 Set_First_Index (Array_Subtype, Index);
11563 Set_Etype (Array_Subtype, Base_Type (Typ));
11564 Set_Is_Constrained (Array_Subtype, True);
11567 Make_Unchecked_Type_Conversion (Loc,
11568 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11569 Expression => Relocate_Node (N)));
11570 Set_Etype (N, Array_Subtype);
11573 end Set_String_Literal_Subtype;
11575 ------------------------------
11576 -- Simplify_Type_Conversion --
11577 ------------------------------
11579 procedure Simplify_Type_Conversion (N : Node_Id) is
11581 if Nkind (N) = N_Type_Conversion then
11583 Operand : constant Node_Id := Expression (N);
11584 Target_Typ : constant Entity_Id := Etype (N);
11585 Opnd_Typ : constant Entity_Id := Etype (Operand);
11588 -- Special processing if the conversion is the expression of a
11589 -- Rounding or Truncation attribute reference. In this case we
11592 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11598 -- with the Float_Truncate flag set to False or True respectively,
11599 -- which is more efficient.
11601 if Is_Floating_Point_Type (Opnd_Typ)
11603 (Is_Integer_Type (Target_Typ)
11604 or else (Is_Fixed_Point_Type (Target_Typ)
11605 and then Conversion_OK (N)))
11606 and then Nkind (Operand) = N_Attribute_Reference
11607 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11611 Truncate : constant Boolean :=
11612 Attribute_Name (Operand) = Name_Truncation;
11615 Relocate_Node (First (Expressions (Operand))));
11616 Set_Float_Truncate (N, Truncate);
11621 end Simplify_Type_Conversion;
11623 -----------------------------
11624 -- Unique_Fixed_Point_Type --
11625 -----------------------------
11627 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11628 T1 : Entity_Id := Empty;
11633 procedure Fixed_Point_Error;
11634 -- Give error messages for true ambiguity. Messages are posted on node
11635 -- N, and entities T1, T2 are the possible interpretations.
11637 -----------------------
11638 -- Fixed_Point_Error --
11639 -----------------------
11641 procedure Fixed_Point_Error is
11643 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11644 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11645 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11646 end Fixed_Point_Error;
11648 -- Start of processing for Unique_Fixed_Point_Type
11651 -- The operations on Duration are visible, so Duration is always a
11652 -- possible interpretation.
11654 T1 := Standard_Duration;
11656 -- Look for fixed-point types in enclosing scopes
11658 Scop := Current_Scope;
11659 while Scop /= Standard_Standard loop
11660 T2 := First_Entity (Scop);
11661 while Present (T2) loop
11662 if Is_Fixed_Point_Type (T2)
11663 and then Current_Entity (T2) = T2
11664 and then Scope (Base_Type (T2)) = Scop
11666 if Present (T1) then
11677 Scop := Scope (Scop);
11680 -- Look for visible fixed type declarations in the context
11682 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11683 while Present (Item) loop
11684 if Nkind (Item) = N_With_Clause then
11685 Scop := Entity (Name (Item));
11686 T2 := First_Entity (Scop);
11687 while Present (T2) loop
11688 if Is_Fixed_Point_Type (T2)
11689 and then Scope (Base_Type (T2)) = Scop
11690 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11692 if Present (T1) then
11707 if Nkind (N) = N_Real_Literal then
11709 ("??real literal interpreted as }!", N, T1);
11712 ("??universal_fixed expression interpreted as }!", N, T1);
11716 end Unique_Fixed_Point_Type;
11718 ----------------------
11719 -- Valid_Conversion --
11720 ----------------------
11722 function Valid_Conversion
11724 Target : Entity_Id;
11726 Report_Errs : Boolean := True) return Boolean
11728 Target_Type : constant Entity_Id := Base_Type (Target);
11729 Opnd_Type : Entity_Id := Etype (Operand);
11730 Inc_Ancestor : Entity_Id;
11732 function Conversion_Check
11734 Msg : String) return Boolean;
11735 -- Little routine to post Msg if Valid is False, returns Valid value
11737 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11738 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11740 procedure Conversion_Error_NE
11742 N : Node_Or_Entity_Id;
11743 E : Node_Or_Entity_Id);
11744 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11746 function Valid_Tagged_Conversion
11747 (Target_Type : Entity_Id;
11748 Opnd_Type : Entity_Id) return Boolean;
11749 -- Specifically test for validity of tagged conversions
11751 function Valid_Array_Conversion return Boolean;
11752 -- Check index and component conformance, and accessibility levels if
11753 -- the component types are anonymous access types (Ada 2005).
11755 ----------------------
11756 -- Conversion_Check --
11757 ----------------------
11759 function Conversion_Check
11761 Msg : String) return Boolean
11766 -- A generic unit has already been analyzed and we have verified
11767 -- that a particular conversion is OK in that context. Since the
11768 -- instance is reanalyzed without relying on the relationships
11769 -- established during the analysis of the generic, it is possible
11770 -- to end up with inconsistent views of private types. Do not emit
11771 -- the error message in such cases. The rest of the machinery in
11772 -- Valid_Conversion still ensures the proper compatibility of
11773 -- target and operand types.
11775 and then not In_Instance
11777 Conversion_Error_N (Msg, Operand);
11781 end Conversion_Check;
11783 ------------------------
11784 -- Conversion_Error_N --
11785 ------------------------
11787 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11789 if Report_Errs then
11790 Error_Msg_N (Msg, N);
11792 end Conversion_Error_N;
11794 -------------------------
11795 -- Conversion_Error_NE --
11796 -------------------------
11798 procedure Conversion_Error_NE
11800 N : Node_Or_Entity_Id;
11801 E : Node_Or_Entity_Id)
11804 if Report_Errs then
11805 Error_Msg_NE (Msg, N, E);
11807 end Conversion_Error_NE;
11809 ----------------------------
11810 -- Valid_Array_Conversion --
11811 ----------------------------
11813 function Valid_Array_Conversion return Boolean
11815 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11816 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11818 Opnd_Index : Node_Id;
11819 Opnd_Index_Type : Entity_Id;
11821 Target_Comp_Type : constant Entity_Id :=
11822 Component_Type (Target_Type);
11823 Target_Comp_Base : constant Entity_Id :=
11824 Base_Type (Target_Comp_Type);
11826 Target_Index : Node_Id;
11827 Target_Index_Type : Entity_Id;
11830 -- Error if wrong number of dimensions
11833 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11836 ("incompatible number of dimensions for conversion", Operand);
11839 -- Number of dimensions matches
11842 -- Loop through indexes of the two arrays
11844 Target_Index := First_Index (Target_Type);
11845 Opnd_Index := First_Index (Opnd_Type);
11846 while Present (Target_Index) and then Present (Opnd_Index) loop
11847 Target_Index_Type := Etype (Target_Index);
11848 Opnd_Index_Type := Etype (Opnd_Index);
11850 -- Error if index types are incompatible
11852 if not (Is_Integer_Type (Target_Index_Type)
11853 and then Is_Integer_Type (Opnd_Index_Type))
11854 and then (Root_Type (Target_Index_Type)
11855 /= Root_Type (Opnd_Index_Type))
11858 ("incompatible index types for array conversion",
11863 Next_Index (Target_Index);
11864 Next_Index (Opnd_Index);
11867 -- If component types have same base type, all set
11869 if Target_Comp_Base = Opnd_Comp_Base then
11872 -- Here if base types of components are not the same. The only
11873 -- time this is allowed is if we have anonymous access types.
11875 -- The conversion of arrays of anonymous access types can lead
11876 -- to dangling pointers. AI-392 formalizes the accessibility
11877 -- checks that must be applied to such conversions to prevent
11878 -- out-of-scope references.
11881 (Target_Comp_Base, E_Anonymous_Access_Type,
11882 E_Anonymous_Access_Subprogram_Type)
11883 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11885 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11887 if Type_Access_Level (Target_Type) <
11888 Deepest_Type_Access_Level (Opnd_Type)
11890 if In_Instance_Body then
11891 Error_Msg_Warn := SPARK_Mode /= On;
11893 ("source array type has deeper accessibility "
11894 & "level than target<<", Operand);
11895 Conversion_Error_N ("\Program_Error [<<", Operand);
11897 Make_Raise_Program_Error (Sloc (N),
11898 Reason => PE_Accessibility_Check_Failed));
11899 Set_Etype (N, Target_Type);
11902 -- Conversion not allowed because of accessibility levels
11906 ("source array type has deeper accessibility "
11907 & "level than target", Operand);
11915 -- All other cases where component base types do not match
11919 ("incompatible component types for array conversion",
11924 -- Check that component subtypes statically match. For numeric
11925 -- types this means that both must be either constrained or
11926 -- unconstrained. For enumeration types the bounds must match.
11927 -- All of this is checked in Subtypes_Statically_Match.
11929 if not Subtypes_Statically_Match
11930 (Target_Comp_Type, Opnd_Comp_Type)
11933 ("component subtypes must statically match", Operand);
11939 end Valid_Array_Conversion;
11941 -----------------------------
11942 -- Valid_Tagged_Conversion --
11943 -----------------------------
11945 function Valid_Tagged_Conversion
11946 (Target_Type : Entity_Id;
11947 Opnd_Type : Entity_Id) return Boolean
11950 -- Upward conversions are allowed (RM 4.6(22))
11952 if Covers (Target_Type, Opnd_Type)
11953 or else Is_Ancestor (Target_Type, Opnd_Type)
11957 -- Downward conversion are allowed if the operand is class-wide
11960 elsif Is_Class_Wide_Type (Opnd_Type)
11961 and then Covers (Opnd_Type, Target_Type)
11965 elsif Covers (Opnd_Type, Target_Type)
11966 or else Is_Ancestor (Opnd_Type, Target_Type)
11969 Conversion_Check (False,
11970 "downward conversion of tagged objects not allowed");
11972 -- Ada 2005 (AI-251): The conversion to/from interface types is
11973 -- always valid. The types involved may be class-wide (sub)types.
11975 elsif Is_Interface (Etype (Base_Type (Target_Type)))
11976 or else Is_Interface (Etype (Base_Type (Opnd_Type)))
11980 -- If the operand is a class-wide type obtained through a limited_
11981 -- with clause, and the context includes the nonlimited view, use
11982 -- it to determine whether the conversion is legal.
11984 elsif Is_Class_Wide_Type (Opnd_Type)
11985 and then From_Limited_With (Opnd_Type)
11986 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11987 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11991 elsif Is_Access_Type (Opnd_Type)
11992 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11997 Conversion_Error_NE
11998 ("invalid tagged conversion, not compatible with}",
11999 N, First_Subtype (Opnd_Type));
12002 end Valid_Tagged_Conversion;
12004 -- Start of processing for Valid_Conversion
12007 Check_Parameterless_Call (Operand);
12009 if Is_Overloaded (Operand) then
12019 -- Remove procedure calls, which syntactically cannot appear in
12020 -- this context, but which cannot be removed by type checking,
12021 -- because the context does not impose a type.
12023 -- The node may be labelled overloaded, but still contain only one
12024 -- interpretation because others were discarded earlier. If this
12025 -- is the case, retain the single interpretation if legal.
12027 Get_First_Interp (Operand, I, It);
12028 Opnd_Type := It.Typ;
12029 Get_Next_Interp (I, It);
12031 if Present (It.Typ)
12032 and then Opnd_Type /= Standard_Void_Type
12034 -- More than one candidate interpretation is available
12036 Get_First_Interp (Operand, I, It);
12037 while Present (It.Typ) loop
12038 if It.Typ = Standard_Void_Type then
12042 -- When compiling for a system where Address is of a visible
12043 -- integer type, spurious ambiguities can be produced when
12044 -- arithmetic operations have a literal operand and return
12045 -- System.Address or a descendant of it. These ambiguities
12046 -- are usually resolved by the context, but for conversions
12047 -- there is no context type and the removal of the spurious
12048 -- operations must be done explicitly here.
12050 if not Address_Is_Private
12051 and then Is_Descendant_Of_Address (It.Typ)
12056 Get_Next_Interp (I, It);
12060 Get_First_Interp (Operand, I, It);
12064 if No (It.Typ) then
12065 Conversion_Error_N ("illegal operand in conversion", Operand);
12069 Get_Next_Interp (I, It);
12071 if Present (It.Typ) then
12074 It1 := Disambiguate (Operand, I1, I, Any_Type);
12076 if It1 = No_Interp then
12078 ("ambiguous operand in conversion", Operand);
12080 -- If the interpretation involves a standard operator, use
12081 -- the location of the type, which may be user-defined.
12083 if Sloc (It.Nam) = Standard_Location then
12084 Error_Msg_Sloc := Sloc (It.Typ);
12086 Error_Msg_Sloc := Sloc (It.Nam);
12089 Conversion_Error_N -- CODEFIX
12090 ("\\possible interpretation#!", Operand);
12092 if Sloc (N1) = Standard_Location then
12093 Error_Msg_Sloc := Sloc (T1);
12095 Error_Msg_Sloc := Sloc (N1);
12098 Conversion_Error_N -- CODEFIX
12099 ("\\possible interpretation#!", Operand);
12105 Set_Etype (Operand, It1.Typ);
12106 Opnd_Type := It1.Typ;
12110 -- Deal with conversion of integer type to address if the pragma
12111 -- Allow_Integer_Address is in effect. We convert the conversion to
12112 -- an unchecked conversion in this case and we are all done.
12114 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12115 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12116 Analyze_And_Resolve (N, Target_Type);
12120 -- If we are within a child unit, check whether the type of the
12121 -- expression has an ancestor in a parent unit, in which case it
12122 -- belongs to its derivation class even if the ancestor is private.
12123 -- See RM 7.3.1 (5.2/3).
12125 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12129 if Is_Numeric_Type (Target_Type) then
12131 -- A universal fixed expression can be converted to any numeric type
12133 if Opnd_Type = Universal_Fixed then
12136 -- Also no need to check when in an instance or inlined body, because
12137 -- the legality has been established when the template was analyzed.
12138 -- Furthermore, numeric conversions may occur where only a private
12139 -- view of the operand type is visible at the instantiation point.
12140 -- This results in a spurious error if we check that the operand type
12141 -- is a numeric type.
12143 -- Note: in a previous version of this unit, the following tests were
12144 -- applied only for generated code (Comes_From_Source set to False),
12145 -- but in fact the test is required for source code as well, since
12146 -- this situation can arise in source code.
12148 elsif In_Instance or else In_Inlined_Body then
12151 -- Otherwise we need the conversion check
12154 return Conversion_Check
12155 (Is_Numeric_Type (Opnd_Type)
12157 (Present (Inc_Ancestor)
12158 and then Is_Numeric_Type (Inc_Ancestor)),
12159 "illegal operand for numeric conversion");
12164 elsif Is_Array_Type (Target_Type) then
12165 if not Is_Array_Type (Opnd_Type)
12166 or else Opnd_Type = Any_Composite
12167 or else Opnd_Type = Any_String
12170 ("illegal operand for array conversion", Operand);
12174 return Valid_Array_Conversion;
12177 -- Ada 2005 (AI-251): Internally generated conversions of access to
12178 -- interface types added to force the displacement of the pointer to
12179 -- reference the corresponding dispatch table.
12181 elsif not Comes_From_Source (N)
12182 and then Is_Access_Type (Target_Type)
12183 and then Is_Interface (Designated_Type (Target_Type))
12187 -- Ada 2005 (AI-251): Anonymous access types where target references an
12190 elsif Is_Access_Type (Opnd_Type)
12191 and then Ekind_In (Target_Type, E_General_Access_Type,
12192 E_Anonymous_Access_Type)
12193 and then Is_Interface (Directly_Designated_Type (Target_Type))
12195 -- Check the static accessibility rule of 4.6(17). Note that the
12196 -- check is not enforced when within an instance body, since the
12197 -- RM requires such cases to be caught at run time.
12199 -- If the operand is a rewriting of an allocator no check is needed
12200 -- because there are no accessibility issues.
12202 if Nkind (Original_Node (N)) = N_Allocator then
12205 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12206 if Type_Access_Level (Opnd_Type) >
12207 Deepest_Type_Access_Level (Target_Type)
12209 -- In an instance, this is a run-time check, but one we know
12210 -- will fail, so generate an appropriate warning. The raise
12211 -- will be generated by Expand_N_Type_Conversion.
12213 if In_Instance_Body then
12214 Error_Msg_Warn := SPARK_Mode /= On;
12216 ("cannot convert local pointer to non-local access type<<",
12218 Conversion_Error_N ("\Program_Error [<<", Operand);
12222 ("cannot convert local pointer to non-local access type",
12227 -- Special accessibility checks are needed in the case of access
12228 -- discriminants declared for a limited type.
12230 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12231 and then not Is_Local_Anonymous_Access (Opnd_Type)
12233 -- When the operand is a selected access discriminant the check
12234 -- needs to be made against the level of the object denoted by
12235 -- the prefix of the selected name (Object_Access_Level handles
12236 -- checking the prefix of the operand for this case).
12238 if Nkind (Operand) = N_Selected_Component
12239 and then Object_Access_Level (Operand) >
12240 Deepest_Type_Access_Level (Target_Type)
12242 -- In an instance, this is a run-time check, but one we know
12243 -- will fail, so generate an appropriate warning. The raise
12244 -- will be generated by Expand_N_Type_Conversion.
12246 if In_Instance_Body then
12247 Error_Msg_Warn := SPARK_Mode /= On;
12249 ("cannot convert access discriminant to non-local "
12250 & "access type<<", Operand);
12251 Conversion_Error_N ("\Program_Error [<<", Operand);
12253 -- Real error if not in instance body
12257 ("cannot convert access discriminant to non-local "
12258 & "access type", Operand);
12263 -- The case of a reference to an access discriminant from
12264 -- within a limited type declaration (which will appear as
12265 -- a discriminal) is always illegal because the level of the
12266 -- discriminant is considered to be deeper than any (nameable)
12269 if Is_Entity_Name (Operand)
12270 and then not Is_Local_Anonymous_Access (Opnd_Type)
12272 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12273 and then Present (Discriminal_Link (Entity (Operand)))
12276 ("discriminant has deeper accessibility level than target",
12285 -- General and anonymous access types
12287 elsif Ekind_In (Target_Type, E_General_Access_Type,
12288 E_Anonymous_Access_Type)
12291 (Is_Access_Type (Opnd_Type)
12293 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12294 E_Access_Protected_Subprogram_Type),
12295 "must be an access-to-object type")
12297 if Is_Access_Constant (Opnd_Type)
12298 and then not Is_Access_Constant (Target_Type)
12301 ("access-to-constant operand type not allowed", Operand);
12305 -- Check the static accessibility rule of 4.6(17). Note that the
12306 -- check is not enforced when within an instance body, since the RM
12307 -- requires such cases to be caught at run time.
12309 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12310 or else Is_Local_Anonymous_Access (Target_Type)
12311 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12312 N_Object_Declaration
12314 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12315 -- conversions from an anonymous access type to a named general
12316 -- access type. Such conversions are not allowed in the case of
12317 -- access parameters and stand-alone objects of an anonymous
12318 -- access type. The implicit conversion case is recognized by
12319 -- testing that Comes_From_Source is False and that it's been
12320 -- rewritten. The Comes_From_Source test isn't sufficient because
12321 -- nodes in inlined calls to predefined library routines can have
12322 -- Comes_From_Source set to False. (Is there a better way to test
12323 -- for implicit conversions???)
12325 if Ada_Version >= Ada_2012
12326 and then not Comes_From_Source (N)
12327 and then N /= Original_Node (N)
12328 and then Ekind (Target_Type) = E_General_Access_Type
12329 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12331 if Is_Itype (Opnd_Type) then
12333 -- Implicit conversions aren't allowed for objects of an
12334 -- anonymous access type, since such objects have nonstatic
12335 -- levels in Ada 2012.
12337 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12338 N_Object_Declaration
12341 ("implicit conversion of stand-alone anonymous "
12342 & "access object not allowed", Operand);
12345 -- Implicit conversions aren't allowed for anonymous access
12346 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12347 -- is done to exclude anonymous access results.
12349 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12350 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12351 N_Function_Specification,
12352 N_Procedure_Specification)
12355 ("implicit conversion of anonymous access formal "
12356 & "not allowed", Operand);
12359 -- This is a case where there's an enclosing object whose
12360 -- to which the "statically deeper than" relationship does
12361 -- not apply (such as an access discriminant selected from
12362 -- a dereference of an access parameter).
12364 elsif Object_Access_Level (Operand)
12365 = Scope_Depth (Standard_Standard)
12368 ("implicit conversion of anonymous access value "
12369 & "not allowed", Operand);
12372 -- In other cases, the level of the operand's type must be
12373 -- statically less deep than that of the target type, else
12374 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12376 elsif Type_Access_Level (Opnd_Type) >
12377 Deepest_Type_Access_Level (Target_Type)
12380 ("implicit conversion of anonymous access value "
12381 & "violates accessibility", Operand);
12386 elsif Type_Access_Level (Opnd_Type) >
12387 Deepest_Type_Access_Level (Target_Type)
12389 -- In an instance, this is a run-time check, but one we know
12390 -- will fail, so generate an appropriate warning. The raise
12391 -- will be generated by Expand_N_Type_Conversion.
12393 if In_Instance_Body then
12394 Error_Msg_Warn := SPARK_Mode /= On;
12396 ("cannot convert local pointer to non-local access type<<",
12398 Conversion_Error_N ("\Program_Error [<<", Operand);
12400 -- If not in an instance body, this is a real error
12403 -- Avoid generation of spurious error message
12405 if not Error_Posted (N) then
12407 ("cannot convert local pointer to non-local access type",
12414 -- Special accessibility checks are needed in the case of access
12415 -- discriminants declared for a limited type.
12417 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12418 and then not Is_Local_Anonymous_Access (Opnd_Type)
12420 -- When the operand is a selected access discriminant the check
12421 -- needs to be made against the level of the object denoted by
12422 -- the prefix of the selected name (Object_Access_Level handles
12423 -- checking the prefix of the operand for this case).
12425 if Nkind (Operand) = N_Selected_Component
12426 and then Object_Access_Level (Operand) >
12427 Deepest_Type_Access_Level (Target_Type)
12429 -- In an instance, this is a run-time check, but one we know
12430 -- will fail, so generate an appropriate warning. The raise
12431 -- will be generated by Expand_N_Type_Conversion.
12433 if In_Instance_Body then
12434 Error_Msg_Warn := SPARK_Mode /= On;
12436 ("cannot convert access discriminant to non-local "
12437 & "access type<<", Operand);
12438 Conversion_Error_N ("\Program_Error [<<", Operand);
12440 -- If not in an instance body, this is a real error
12444 ("cannot convert access discriminant to non-local "
12445 & "access type", Operand);
12450 -- The case of a reference to an access discriminant from
12451 -- within a limited type declaration (which will appear as
12452 -- a discriminal) is always illegal because the level of the
12453 -- discriminant is considered to be deeper than any (nameable)
12456 if Is_Entity_Name (Operand)
12458 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12459 and then Present (Discriminal_Link (Entity (Operand)))
12462 ("discriminant has deeper accessibility level than target",
12469 -- In the presence of limited_with clauses we have to use nonlimited
12470 -- views, if available.
12472 Check_Limited : declare
12473 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12474 -- Helper function to handle limited views
12476 --------------------------
12477 -- Full_Designated_Type --
12478 --------------------------
12480 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12481 Desig : constant Entity_Id := Designated_Type (T);
12484 -- Handle the limited view of a type
12486 if From_Limited_With (Desig)
12487 and then Has_Non_Limited_View (Desig)
12489 return Available_View (Desig);
12493 end Full_Designated_Type;
12495 -- Local Declarations
12497 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12498 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12500 Same_Base : constant Boolean :=
12501 Base_Type (Target) = Base_Type (Opnd);
12503 -- Start of processing for Check_Limited
12506 if Is_Tagged_Type (Target) then
12507 return Valid_Tagged_Conversion (Target, Opnd);
12510 if not Same_Base then
12511 Conversion_Error_NE
12512 ("target designated type not compatible with }",
12513 N, Base_Type (Opnd));
12516 -- Ada 2005 AI-384: legality rule is symmetric in both
12517 -- designated types. The conversion is legal (with possible
12518 -- constraint check) if either designated type is
12521 elsif Subtypes_Statically_Match (Target, Opnd)
12523 (Has_Discriminants (Target)
12525 (not Is_Constrained (Opnd)
12526 or else not Is_Constrained (Target)))
12528 -- Special case, if Value_Size has been used to make the
12529 -- sizes different, the conversion is not allowed even
12530 -- though the subtypes statically match.
12532 if Known_Static_RM_Size (Target)
12533 and then Known_Static_RM_Size (Opnd)
12534 and then RM_Size (Target) /= RM_Size (Opnd)
12536 Conversion_Error_NE
12537 ("target designated subtype not compatible with }",
12539 Conversion_Error_NE
12540 ("\because sizes of the two designated subtypes differ",
12544 -- Normal case where conversion is allowed
12552 ("target designated subtype not compatible with }",
12559 -- Access to subprogram types. If the operand is an access parameter,
12560 -- the type has a deeper accessibility that any master, and cannot be
12561 -- assigned. We must make an exception if the conversion is part of an
12562 -- assignment and the target is the return object of an extended return
12563 -- statement, because in that case the accessibility check takes place
12564 -- after the return.
12566 elsif Is_Access_Subprogram_Type (Target_Type)
12568 -- Note: this test of Opnd_Type is there to prevent entering this
12569 -- branch in the case of a remote access to subprogram type, which
12570 -- is internally represented as an E_Record_Type.
12572 and then Is_Access_Type (Opnd_Type)
12574 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12575 and then Is_Entity_Name (Operand)
12576 and then Ekind (Entity (Operand)) = E_In_Parameter
12578 (Nkind (Parent (N)) /= N_Assignment_Statement
12579 or else not Is_Entity_Name (Name (Parent (N)))
12580 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12583 ("illegal attempt to store anonymous access to subprogram",
12586 ("\value has deeper accessibility than any master "
12587 & "(RM 3.10.2 (13))",
12591 ("\use named access type for& instead of access parameter",
12592 Operand, Entity (Operand));
12595 -- Check that the designated types are subtype conformant
12597 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12598 Old_Id => Designated_Type (Opnd_Type),
12601 -- Check the static accessibility rule of 4.6(20)
12603 if Type_Access_Level (Opnd_Type) >
12604 Deepest_Type_Access_Level (Target_Type)
12607 ("operand type has deeper accessibility level than target",
12610 -- Check that if the operand type is declared in a generic body,
12611 -- then the target type must be declared within that same body
12612 -- (enforces last sentence of 4.6(20)).
12614 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12616 O_Gen : constant Node_Id :=
12617 Enclosing_Generic_Body (Opnd_Type);
12622 T_Gen := Enclosing_Generic_Body (Target_Type);
12623 while Present (T_Gen) and then T_Gen /= O_Gen loop
12624 T_Gen := Enclosing_Generic_Body (T_Gen);
12627 if T_Gen /= O_Gen then
12629 ("target type must be declared in same generic body "
12630 & "as operand type", N);
12637 -- Remote access to subprogram types
12639 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12640 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12642 -- It is valid to convert from one RAS type to another provided
12643 -- that their specification statically match.
12645 -- Note: at this point, remote access to subprogram types have been
12646 -- expanded to their E_Record_Type representation, and we need to
12647 -- go back to the original access type definition using the
12648 -- Corresponding_Remote_Type attribute in order to check that the
12649 -- designated profiles match.
12651 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12652 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12654 Check_Subtype_Conformant
12656 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12658 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12663 -- If it was legal in the generic, it's legal in the instance
12665 elsif In_Instance_Body then
12668 -- If both are tagged types, check legality of view conversions
12670 elsif Is_Tagged_Type (Target_Type)
12672 Is_Tagged_Type (Opnd_Type)
12674 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12676 -- Types derived from the same root type are convertible
12678 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12681 -- In an instance or an inlined body, there may be inconsistent views of
12682 -- the same type, or of types derived from a common root.
12684 elsif (In_Instance or In_Inlined_Body)
12686 Root_Type (Underlying_Type (Target_Type)) =
12687 Root_Type (Underlying_Type (Opnd_Type))
12691 -- Special check for common access type error case
12693 elsif Ekind (Target_Type) = E_Access_Type
12694 and then Is_Access_Type (Opnd_Type)
12696 Conversion_Error_N ("target type must be general access type!", N);
12697 Conversion_Error_NE -- CODEFIX
12698 ("add ALL to }!", N, Target_Type);
12701 -- Here we have a real conversion error
12704 Conversion_Error_NE
12705 ("invalid conversion, not compatible with }", N, Opnd_Type);
12708 end Valid_Conversion;