1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Inline; use Inline;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch4; use Sem_Ch4;
58 with Sem_Ch6; use Sem_Ch6;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Dim; use Sem_Dim;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Elim; use Sem_Elim;
65 with Sem_Elab; use Sem_Elab;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Intr; use Sem_Intr;
68 with Sem_Util; use Sem_Util;
69 with Targparm; use Targparm;
70 with Sem_Type; use Sem_Type;
71 with Sem_Warn; use Sem_Warn;
72 with Sinfo; use Sinfo;
73 with Sinfo.CN; use Sinfo.CN;
74 with Snames; use Snames;
75 with Stand; use Stand;
76 with Stringt; use Stringt;
77 with Style; use Style;
78 with Tbuild; use Tbuild;
79 with Uintp; use Uintp;
80 with Urealp; use Urealp;
82 package body Sem_Res is
84 -----------------------
85 -- Local Subprograms --
86 -----------------------
88 -- Second pass (top-down) type checking and overload resolution procedures
89 -- Typ is the type required by context. These procedures propagate the type
90 -- information recursively to the descendants of N. If the node is not
91 -- overloaded, its Etype is established in the first pass. If overloaded,
92 -- the Resolve routines set the correct type. For arith. operators, the
93 -- Etype is the base type of the context.
95 -- Note that Resolve_Attribute is separated off in Sem_Attr
97 procedure Check_Discriminant_Use (N : Node_Id);
98 -- Enforce the restrictions on the use of discriminants when constraining
99 -- a component of a discriminated type (record or concurrent type).
101 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
102 -- Given a node for an operator associated with type T, check that
103 -- the operator is visible. Operators all of whose operands are
104 -- universal must be checked for visibility during resolution
105 -- because their type is not determinable based on their operands.
107 procedure Check_Fully_Declared_Prefix
110 -- Check that the type of the prefix of a dereference is not incomplete
112 procedure Check_Ghost_Context (Ghost_Id : Entity_Id; Ghost_Ref : Node_Id);
113 -- Determine whether node Ghost_Ref appears within a Ghost-friendly context
114 -- where Ghost entity Ghost_Id can safely reside.
116 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
117 -- Given a call node, N, which is known to occur immediately within the
118 -- subprogram being called, determines whether it is a detectable case of
119 -- an infinite recursion, and if so, outputs appropriate messages. Returns
120 -- True if an infinite recursion is detected, and False otherwise.
122 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
123 -- If the type of the object being initialized uses the secondary stack
124 -- directly or indirectly, create a transient scope for the call to the
125 -- init proc. This is because we do not create transient scopes for the
126 -- initialization of individual components within the init proc itself.
127 -- Could be optimized away perhaps?
129 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
130 -- N is the node for a logical operator. If the operator is predefined, and
131 -- the root type of the operands is Standard.Boolean, then a check is made
132 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
133 -- the style check for Style_Check_Boolean_And_Or.
135 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
136 -- N is either an indexed component or a selected component. This function
137 -- returns true if the prefix refers to an object that has an address
138 -- clause (the case in which we may want to issue a warning).
140 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
141 -- Determine whether E is an access type declared by an access declaration,
142 -- and not an (anonymous) allocator type.
144 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
145 -- Utility to check whether the entity for an operator is a predefined
146 -- operator, in which case the expression is left as an operator in the
147 -- tree (else it is rewritten into a call). An instance of an intrinsic
148 -- conversion operation may be given an operator name, but is not treated
149 -- like an operator. Note that an operator that is an imported back-end
150 -- builtin has convention Intrinsic, but is expected to be rewritten into
151 -- a call, so such an operator is not treated as predefined by this
154 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
155 -- If a default expression in entry call N depends on the discriminants
156 -- of the task, it must be replaced with a reference to the discriminant
157 -- of the task being called.
159 procedure Resolve_Op_Concat_Arg
164 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
165 -- concatenation operator. The operand is either of the array type or of
166 -- the component type. If the operand is an aggregate, and the component
167 -- type is composite, this is ambiguous if component type has aggregates.
169 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
170 -- Does the first part of the work of Resolve_Op_Concat
172 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
173 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
174 -- has been resolved. See Resolve_Op_Concat for details.
176 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
210 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
212 function Operator_Kind
214 Is_Binary : Boolean) return Node_Kind;
215 -- Utility to map the name of an operator into the corresponding Node. Used
216 -- by other node rewriting procedures.
218 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
219 -- Resolve actuals of call, and add default expressions for missing ones.
220 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
221 -- called subprogram.
223 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
224 -- Called from Resolve_Call, when the prefix denotes an entry or element
225 -- of entry family. Actuals are resolved as for subprograms, and the node
226 -- is rebuilt as an entry call. Also called for protected operations. Typ
227 -- is the context type, which is used when the operation is a protected
228 -- function with no arguments, and the return value is indexed.
230 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
231 -- A call to a user-defined intrinsic operator is rewritten as a call to
232 -- the corresponding predefined operator, with suitable conversions. Note
233 -- that this applies only for intrinsic operators that denote predefined
234 -- operators, not ones that are intrinsic imports of back-end builtins.
236 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
237 -- Ditto, for arithmetic unary operators
239 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
240 -- If an operator node resolves to a call to a user-defined operator,
241 -- rewrite the node as a function call.
243 procedure Make_Call_Into_Operator
247 -- Inverse transformation: if an operator is given in functional notation,
248 -- then after resolving the node, transform into an operator node, so
249 -- that operands are resolved properly. Recall that predefined operators
250 -- do not have a full signature and special resolution rules apply.
252 procedure Rewrite_Renamed_Operator
256 -- An operator can rename another, e.g. in an instantiation. In that
257 -- case, the proper operator node must be constructed and resolved.
259 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
260 -- The String_Literal_Subtype is built for all strings that are not
261 -- operands of a static concatenation operation. If the argument is
262 -- not a N_String_Literal node, then the call has no effect.
264 procedure Set_Slice_Subtype (N : Node_Id);
265 -- Build subtype of array type, with the range specified by the slice
267 procedure Simplify_Type_Conversion (N : Node_Id);
268 -- Called after N has been resolved and evaluated, but before range checks
269 -- have been applied. Currently simplifies a combination of floating-point
270 -- to integer conversion and Rounding or Truncation attribute.
272 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
273 -- A universal_fixed expression in an universal context is unambiguous if
274 -- there is only one applicable fixed point type. Determining whether there
275 -- is only one requires a search over all visible entities, and happens
276 -- only in very pathological cases (see 6115-006).
278 -------------------------
279 -- Ambiguous_Character --
280 -------------------------
282 procedure Ambiguous_Character (C : Node_Id) is
286 if Nkind (C) = N_Character_Literal then
287 Error_Msg_N ("ambiguous character literal", C);
289 -- First the ones in Standard
291 Error_Msg_N ("\\possible interpretation: Character!", C);
292 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
294 -- Include Wide_Wide_Character in Ada 2005 mode
296 if Ada_Version >= Ada_2005 then
297 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
300 -- Now any other types that match
302 E := Current_Entity (C);
303 while Present (E) loop
304 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
308 end Ambiguous_Character;
310 -------------------------
311 -- Analyze_And_Resolve --
312 -------------------------
314 procedure Analyze_And_Resolve (N : Node_Id) is
318 end Analyze_And_Resolve;
320 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
324 end Analyze_And_Resolve;
326 -- Versions with check(s) suppressed
328 procedure Analyze_And_Resolve
333 Scop : constant Entity_Id := Current_Scope;
336 if Suppress = All_Checks then
338 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
340 Scope_Suppress.Suppress := (others => True);
341 Analyze_And_Resolve (N, Typ);
342 Scope_Suppress.Suppress := Sva;
347 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
349 Scope_Suppress.Suppress (Suppress) := True;
350 Analyze_And_Resolve (N, Typ);
351 Scope_Suppress.Suppress (Suppress) := Svg;
355 if Current_Scope /= Scop
356 and then Scope_Is_Transient
358 -- This can only happen if a transient scope was created for an inner
359 -- expression, which will be removed upon completion of the analysis
360 -- of an enclosing construct. The transient scope must have the
361 -- suppress status of the enclosing environment, not of this Analyze
364 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
367 end Analyze_And_Resolve;
369 procedure Analyze_And_Resolve
373 Scop : constant Entity_Id := Current_Scope;
376 if Suppress = All_Checks then
378 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
380 Scope_Suppress.Suppress := (others => True);
381 Analyze_And_Resolve (N);
382 Scope_Suppress.Suppress := Sva;
387 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
389 Scope_Suppress.Suppress (Suppress) := True;
390 Analyze_And_Resolve (N);
391 Scope_Suppress.Suppress (Suppress) := Svg;
395 if Current_Scope /= Scop and then Scope_Is_Transient then
396 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
399 end Analyze_And_Resolve;
401 ----------------------------
402 -- Check_Discriminant_Use --
403 ----------------------------
405 procedure Check_Discriminant_Use (N : Node_Id) is
406 PN : constant Node_Id := Parent (N);
407 Disc : constant Entity_Id := Entity (N);
412 -- Any use in a spec-expression is legal
414 if In_Spec_Expression then
417 elsif Nkind (PN) = N_Range then
419 -- Discriminant cannot be used to constrain a scalar type
423 if Nkind (P) = N_Range_Constraint
424 and then Nkind (Parent (P)) = N_Subtype_Indication
425 and then Nkind (Parent (Parent (P))) = N_Component_Definition
427 Error_Msg_N ("discriminant cannot constrain scalar type", N);
429 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
431 -- The following check catches the unusual case where a
432 -- discriminant appears within an index constraint that is part of
433 -- a larger expression within a constraint on a component, e.g. "C
434 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
435 -- of record components, and note that a similar check should also
436 -- apply in the case of discriminant constraints below. ???
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_Ghost_Context --
697 -------------------------
699 procedure Check_Ghost_Context (Ghost_Id : Entity_Id; Ghost_Ref : Node_Id) is
700 procedure Check_Ghost_Policy (Id : Entity_Id; Err_N : Node_Id);
701 -- Verify that the Ghost policy at the point of declaration of entity Id
702 -- matches the policy at the point of reference. If this is not the case
703 -- emit an error at Err_N.
705 function Is_OK_Ghost_Context (Context : Node_Id) return Boolean;
706 -- Determine whether node Context denotes a Ghost-friendly context where
707 -- a Ghost entity can safely reside.
709 -------------------------
710 -- Is_OK_Ghost_Context --
711 -------------------------
713 function Is_OK_Ghost_Context (Context : Node_Id) return Boolean is
714 function Is_Ghost_Declaration (Decl : Node_Id) return Boolean;
715 -- Determine whether node Decl is a Ghost declaration or appears
716 -- within a Ghost declaration.
718 --------------------------
719 -- Is_Ghost_Declaration --
720 --------------------------
722 function Is_Ghost_Declaration (Decl : Node_Id) return Boolean is
728 -- Climb the parent chain looking for an object declaration
731 while Present (Par) loop
733 when N_Abstract_Subprogram_Declaration |
734 N_Exception_Declaration |
735 N_Exception_Renaming_Declaration |
736 N_Full_Type_Declaration |
737 N_Generic_Function_Renaming_Declaration |
738 N_Generic_Package_Declaration |
739 N_Generic_Package_Renaming_Declaration |
740 N_Generic_Procedure_Renaming_Declaration |
741 N_Generic_Subprogram_Declaration |
742 N_Number_Declaration |
743 N_Object_Declaration |
744 N_Object_Renaming_Declaration |
745 N_Package_Declaration |
746 N_Package_Renaming_Declaration |
747 N_Private_Extension_Declaration |
748 N_Private_Type_Declaration |
749 N_Subprogram_Declaration |
750 N_Subprogram_Renaming_Declaration |
751 N_Subtype_Declaration =>
752 return Is_Subject_To_Ghost (Par);
760 -- A reference to a Ghost entity may appear as the default
761 -- expression of a formal parameter of a subprogram body. This
762 -- context must be treated as suitable because the relation
763 -- between the spec and the body has not been established and
764 -- the body is not marked as Ghost yet. The real check was
765 -- performed on the spec.
767 if Nkind (Par) = N_Parameter_Specification
768 and then Nkind (Parent (Parent (Par))) = N_Subprogram_Body
772 -- References to Ghost entities may be relocated in internally
775 elsif Nkind (Par) = N_Subprogram_Body
776 and then not Comes_From_Source (Par)
778 Subp_Id := Corresponding_Spec (Par);
780 -- The original context is an expression function that has
781 -- been split into a spec and a body. The context is OK as
782 -- long as the the initial declaration is Ghost.
784 if Present (Subp_Id) then
786 Original_Node (Unit_Declaration_Node (Subp_Id));
788 if Nkind (Subp_Decl) = N_Expression_Function then
789 return Is_Subject_To_Ghost (Subp_Decl);
793 -- Otherwise this is either an internal body or an internal
794 -- completion. Both are OK because the real check was done
795 -- before expansion activities.
800 -- Prevent the search from going too far
802 if Is_Body_Or_Package_Declaration (Par) then
810 end Is_Ghost_Declaration;
812 -- Start of processing for Is_OK_Ghost_Context
815 -- The Ghost entity appears within an assertion expression
817 if In_Assertion_Expr > 0 then
820 -- The Ghost entity is part of a declaration or its completion
822 elsif Is_Ghost_Declaration (Context) then
825 -- The Ghost entity is referenced within a Ghost statement
827 elsif Is_Ghost_Statement_Or_Pragma (Context) then
833 end Is_OK_Ghost_Context;
835 ------------------------
836 -- Check_Ghost_Policy --
837 ------------------------
839 procedure Check_Ghost_Policy (Id : Entity_Id; Err_N : Node_Id) is
840 Policy : constant Name_Id := Policy_In_Effect (Name_Ghost);
843 -- The Ghost policy in effect a the point of declaration and at the
844 -- point of use must match (SPARK RM 6.9(14)).
846 if Is_Checked_Ghost_Entity (Id) and then Policy = Name_Ignore then
847 Error_Msg_Sloc := Sloc (Err_N);
849 Error_Msg_N ("incompatible ghost policies in effect", Err_N);
850 Error_Msg_NE ("\& declared with ghost policy Check", Err_N, Id);
851 Error_Msg_NE ("\& used # with ghost policy Ignore", Err_N, Id);
853 elsif Is_Ignored_Ghost_Entity (Id) and then Policy = Name_Check then
854 Error_Msg_Sloc := Sloc (Err_N);
856 Error_Msg_N ("incompatible ghost policies in effect", Err_N);
857 Error_Msg_NE ("\& declared with ghost policy Ignore", Err_N, Id);
858 Error_Msg_NE ("\& used # with ghost policy Check", Err_N, Id);
860 end Check_Ghost_Policy;
862 -- Start of processing for Check_Ghost_Context
865 -- Once it has been established that the reference to the Ghost entity
866 -- is within a suitable context, ensure that the policy at the point of
867 -- declaration and at the point of use match.
869 if Is_OK_Ghost_Context (Ghost_Ref) then
870 Check_Ghost_Policy (Ghost_Id, Ghost_Ref);
872 -- Otherwise the Ghost entity appears in a non-Ghost context and affects
873 -- its behavior or value.
877 ("ghost entity cannot appear in this context (SPARK RM 6.9(12))",
880 end Check_Ghost_Context;
882 ------------------------------
883 -- Check_Infinite_Recursion --
884 ------------------------------
886 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
890 function Same_Argument_List return Boolean;
891 -- Check whether list of actuals is identical to list of formals of
892 -- called function (which is also the enclosing scope).
894 ------------------------
895 -- Same_Argument_List --
896 ------------------------
898 function Same_Argument_List return Boolean is
904 if not Is_Entity_Name (Name (N)) then
907 Subp := Entity (Name (N));
910 F := First_Formal (Subp);
911 A := First_Actual (N);
912 while Present (F) and then Present (A) loop
913 if not Is_Entity_Name (A)
914 or else Entity (A) /= F
924 end Same_Argument_List;
926 -- Start of processing for Check_Infinite_Recursion
929 -- Special case, if this is a procedure call and is a call to the
930 -- current procedure with the same argument list, then this is for
931 -- sure an infinite recursion and we insert a call to raise SE.
933 if Is_List_Member (N)
934 and then List_Length (List_Containing (N)) = 1
935 and then Same_Argument_List
938 P : constant Node_Id := Parent (N);
940 if Nkind (P) = N_Handled_Sequence_Of_Statements
941 and then Nkind (Parent (P)) = N_Subprogram_Body
942 and then Is_Empty_List (Declarations (Parent (P)))
944 Error_Msg_Warn := SPARK_Mode /= On;
945 Error_Msg_N ("!infinite recursion<<", N);
946 Error_Msg_N ("\!Storage_Error [<<", N);
948 Make_Raise_Storage_Error (Sloc (N),
949 Reason => SE_Infinite_Recursion));
955 -- If not that special case, search up tree, quitting if we reach a
956 -- construct (e.g. a conditional) that tells us that this is not a
957 -- case for an infinite recursion warning.
963 -- If no parent, then we were not inside a subprogram, this can for
964 -- example happen when processing certain pragmas in a spec. Just
965 -- return False in this case.
971 -- Done if we get to subprogram body, this is definitely an infinite
972 -- recursion case if we did not find anything to stop us.
974 exit when Nkind (P) = N_Subprogram_Body;
976 -- If appearing in conditional, result is false
978 if Nkind_In (P, N_Or_Else,
987 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
988 and then C /= First (Statements (P))
990 -- If the call is the expression of a return statement and the
991 -- actuals are identical to the formals, it's worth a warning.
992 -- However, we skip this if there is an immediately preceding
993 -- raise statement, since the call is never executed.
995 -- Furthermore, this corresponds to a common idiom:
997 -- function F (L : Thing) return Boolean is
999 -- raise Program_Error;
1003 -- for generating a stub function
1005 if Nkind (Parent (N)) = N_Simple_Return_Statement
1006 and then Same_Argument_List
1008 exit when not Is_List_Member (Parent (N));
1010 -- OK, return statement is in a statement list, look for raise
1016 -- Skip past N_Freeze_Entity nodes generated by expansion
1018 Nod := Prev (Parent (N));
1020 and then Nkind (Nod) = N_Freeze_Entity
1025 -- If no raise statement, give warning. We look at the
1026 -- original node, because in the case of "raise ... with
1027 -- ...", the node has been transformed into a call.
1029 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
1031 (Nkind (Nod) not in N_Raise_xxx_Error
1032 or else Present (Condition (Nod)));
1043 Error_Msg_Warn := SPARK_Mode /= On;
1044 Error_Msg_N ("!possible infinite recursion<<", N);
1045 Error_Msg_N ("\!??Storage_Error ]<<", N);
1048 end Check_Infinite_Recursion;
1050 -------------------------------
1051 -- Check_Initialization_Call --
1052 -------------------------------
1054 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
1055 Typ : constant Entity_Id := Etype (First_Formal (Nam));
1057 function Uses_SS (T : Entity_Id) return Boolean;
1058 -- Check whether the creation of an object of the type will involve
1059 -- use of the secondary stack. If T is a record type, this is true
1060 -- if the expression for some component uses the secondary stack, e.g.
1061 -- through a call to a function that returns an unconstrained value.
1062 -- False if T is controlled, because cleanups occur elsewhere.
1068 function Uses_SS (T : Entity_Id) return Boolean is
1071 Full_Type : Entity_Id := Underlying_Type (T);
1074 -- Normally we want to use the underlying type, but if it's not set
1075 -- then continue with T.
1077 if not Present (Full_Type) then
1081 if Is_Controlled (Full_Type) then
1084 elsif Is_Array_Type (Full_Type) then
1085 return Uses_SS (Component_Type (Full_Type));
1087 elsif Is_Record_Type (Full_Type) then
1088 Comp := First_Component (Full_Type);
1089 while Present (Comp) loop
1090 if Ekind (Comp) = E_Component
1091 and then Nkind (Parent (Comp)) = N_Component_Declaration
1093 -- The expression for a dynamic component may be rewritten
1094 -- as a dereference, so retrieve original node.
1096 Expr := Original_Node (Expression (Parent (Comp)));
1098 -- Return True if the expression is a call to a function
1099 -- (including an attribute function such as Image, or a
1100 -- user-defined operator) with a result that requires a
1103 if (Nkind (Expr) = N_Function_Call
1104 or else Nkind (Expr) in N_Op
1105 or else (Nkind (Expr) = N_Attribute_Reference
1106 and then Present (Expressions (Expr))))
1107 and then Requires_Transient_Scope (Etype (Expr))
1111 elsif Uses_SS (Etype (Comp)) then
1116 Next_Component (Comp);
1126 -- Start of processing for Check_Initialization_Call
1129 -- Establish a transient scope if the type needs it
1131 if Uses_SS (Typ) then
1132 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
1134 end Check_Initialization_Call;
1136 ---------------------------------------
1137 -- Check_No_Direct_Boolean_Operators --
1138 ---------------------------------------
1140 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
1142 if Scope (Entity (N)) = Standard_Standard
1143 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
1145 -- Restriction only applies to original source code
1147 if Comes_From_Source (N) then
1148 Check_Restriction (No_Direct_Boolean_Operators, N);
1152 -- Do style check (but skip if in instance, error is on template)
1155 if not In_Instance then
1156 Check_Boolean_Operator (N);
1159 end Check_No_Direct_Boolean_Operators;
1161 ------------------------------
1162 -- Check_Parameterless_Call --
1163 ------------------------------
1165 procedure Check_Parameterless_Call (N : Node_Id) is
1168 function Prefix_Is_Access_Subp return Boolean;
1169 -- If the prefix is of an access_to_subprogram type, the node must be
1170 -- rewritten as a call. Ditto if the prefix is overloaded and all its
1171 -- interpretations are access to subprograms.
1173 ---------------------------
1174 -- Prefix_Is_Access_Subp --
1175 ---------------------------
1177 function Prefix_Is_Access_Subp return Boolean is
1182 -- If the context is an attribute reference that can apply to
1183 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1185 if Nkind (Parent (N)) = N_Attribute_Reference
1186 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1193 if not Is_Overloaded (N) then
1195 Ekind (Etype (N)) = E_Subprogram_Type
1196 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1198 Get_First_Interp (N, I, It);
1199 while Present (It.Typ) loop
1200 if Ekind (It.Typ) /= E_Subprogram_Type
1201 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1206 Get_Next_Interp (I, It);
1211 end Prefix_Is_Access_Subp;
1213 -- Start of processing for Check_Parameterless_Call
1216 -- Defend against junk stuff if errors already detected
1218 if Total_Errors_Detected /= 0 then
1219 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1221 elsif Nkind (N) in N_Has_Chars
1222 and then Chars (N) in Error_Name_Or_No_Name
1230 -- If the context expects a value, and the name is a procedure, this is
1231 -- most likely a missing 'Access. Don't try to resolve the parameterless
1232 -- call, error will be caught when the outer call is analyzed.
1234 if Is_Entity_Name (N)
1235 and then Ekind (Entity (N)) = E_Procedure
1236 and then not Is_Overloaded (N)
1238 Nkind_In (Parent (N), N_Parameter_Association,
1240 N_Procedure_Call_Statement)
1245 -- Rewrite as call if overloadable entity that is (or could be, in the
1246 -- overloaded case) a function call. If we know for sure that the entity
1247 -- is an enumeration literal, we do not rewrite it.
1249 -- If the entity is the name of an operator, it cannot be a call because
1250 -- operators cannot have default parameters. In this case, this must be
1251 -- a string whose contents coincide with an operator name. Set the kind
1252 -- of the node appropriately.
1254 if (Is_Entity_Name (N)
1255 and then Nkind (N) /= N_Operator_Symbol
1256 and then Is_Overloadable (Entity (N))
1257 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1258 or else Is_Overloaded (N)))
1260 -- Rewrite as call if it is an explicit dereference of an expression of
1261 -- a subprogram access type, and the subprogram type is not that of a
1262 -- procedure or entry.
1265 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1267 -- Rewrite as call if it is a selected component which is a function,
1268 -- this is the case of a call to a protected function (which may be
1269 -- overloaded with other protected operations).
1272 (Nkind (N) = N_Selected_Component
1273 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1275 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1277 and then Is_Overloaded (Selector_Name (N)))))
1279 -- If one of the above three conditions is met, rewrite as call. Apply
1280 -- the rewriting only once.
1283 if Nkind (Parent (N)) /= N_Function_Call
1284 or else N /= Name (Parent (N))
1287 -- This may be a prefixed call that was not fully analyzed, e.g.
1288 -- an actual in an instance.
1290 if Ada_Version >= Ada_2005
1291 and then Nkind (N) = N_Selected_Component
1292 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1294 Analyze_Selected_Component (N);
1296 if Nkind (N) /= N_Selected_Component then
1301 -- The node is the name of the parameterless call. Preserve its
1302 -- descendants, which may be complex expressions.
1304 Nam := Relocate_Node (N);
1306 -- If overloaded, overload set belongs to new copy
1308 Save_Interps (N, Nam);
1310 -- Change node to parameterless function call (note that the
1311 -- Parameter_Associations associations field is left set to Empty,
1312 -- its normal default value since there are no parameters)
1314 Change_Node (N, N_Function_Call);
1316 Set_Sloc (N, Sloc (Nam));
1320 elsif Nkind (N) = N_Parameter_Association then
1321 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1323 elsif Nkind (N) = N_Operator_Symbol then
1324 Change_Operator_Symbol_To_String_Literal (N);
1325 Set_Is_Overloaded (N, False);
1326 Set_Etype (N, Any_String);
1328 end Check_Parameterless_Call;
1330 --------------------------------
1331 -- Is_Atomic_Ref_With_Address --
1332 --------------------------------
1334 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1335 Pref : constant Node_Id := Prefix (N);
1338 if not Is_Entity_Name (Pref) then
1343 Pent : constant Entity_Id := Entity (Pref);
1344 Ptyp : constant Entity_Id := Etype (Pent);
1346 return not Is_Access_Type (Ptyp)
1347 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1348 and then Present (Address_Clause (Pent));
1351 end Is_Atomic_Ref_With_Address;
1353 -----------------------------
1354 -- Is_Definite_Access_Type --
1355 -----------------------------
1357 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1358 Btyp : constant Entity_Id := Base_Type (E);
1360 return Ekind (Btyp) = E_Access_Type
1361 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1362 and then Comes_From_Source (Btyp));
1363 end Is_Definite_Access_Type;
1365 ----------------------
1366 -- Is_Predefined_Op --
1367 ----------------------
1369 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1371 -- Predefined operators are intrinsic subprograms
1373 if not Is_Intrinsic_Subprogram (Nam) then
1377 -- A call to a back-end builtin is never a predefined operator
1379 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1383 return not Is_Generic_Instance (Nam)
1384 and then Chars (Nam) in Any_Operator_Name
1385 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1386 end Is_Predefined_Op;
1388 -----------------------------
1389 -- Make_Call_Into_Operator --
1390 -----------------------------
1392 procedure Make_Call_Into_Operator
1397 Op_Name : constant Name_Id := Chars (Op_Id);
1398 Act1 : Node_Id := First_Actual (N);
1399 Act2 : Node_Id := Next_Actual (Act1);
1400 Error : Boolean := False;
1401 Func : constant Entity_Id := Entity (Name (N));
1402 Is_Binary : constant Boolean := Present (Act2);
1404 Opnd_Type : Entity_Id;
1405 Orig_Type : Entity_Id := Empty;
1408 type Kind_Test is access function (E : Entity_Id) return Boolean;
1410 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1411 -- If the operand is not universal, and the operator is given by an
1412 -- expanded name, verify that the operand has an interpretation with a
1413 -- type defined in the given scope of the operator.
1415 function Type_In_P (Test : Kind_Test) return Entity_Id;
1416 -- Find a type of the given class in package Pack that contains the
1419 ---------------------------
1420 -- Operand_Type_In_Scope --
1421 ---------------------------
1423 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1424 Nod : constant Node_Id := Right_Opnd (Op_Node);
1429 if not Is_Overloaded (Nod) then
1430 return Scope (Base_Type (Etype (Nod))) = S;
1433 Get_First_Interp (Nod, I, It);
1434 while Present (It.Typ) loop
1435 if Scope (Base_Type (It.Typ)) = S then
1439 Get_Next_Interp (I, It);
1444 end Operand_Type_In_Scope;
1450 function Type_In_P (Test : Kind_Test) return Entity_Id is
1453 function In_Decl return Boolean;
1454 -- Verify that node is not part of the type declaration for the
1455 -- candidate type, which would otherwise be invisible.
1461 function In_Decl return Boolean is
1462 Decl_Node : constant Node_Id := Parent (E);
1468 if Etype (E) = Any_Type then
1471 elsif No (Decl_Node) then
1476 and then Nkind (N2) /= N_Compilation_Unit
1478 if N2 = Decl_Node then
1489 -- Start of processing for Type_In_P
1492 -- If the context type is declared in the prefix package, this is the
1493 -- desired base type.
1495 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1496 return Base_Type (Typ);
1499 E := First_Entity (Pack);
1500 while Present (E) loop
1502 and then not In_Decl
1514 -- Start of processing for Make_Call_Into_Operator
1517 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1522 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1523 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1524 Save_Interps (Act1, Left_Opnd (Op_Node));
1525 Save_Interps (Act2, Right_Opnd (Op_Node));
1526 Act1 := Left_Opnd (Op_Node);
1527 Act2 := Right_Opnd (Op_Node);
1532 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1533 Save_Interps (Act1, Right_Opnd (Op_Node));
1534 Act1 := Right_Opnd (Op_Node);
1537 -- If the operator is denoted by an expanded name, and the prefix is
1538 -- not Standard, but the operator is a predefined one whose scope is
1539 -- Standard, then this is an implicit_operator, inserted as an
1540 -- interpretation by the procedure of the same name. This procedure
1541 -- overestimates the presence of implicit operators, because it does
1542 -- not examine the type of the operands. Verify now that the operand
1543 -- type appears in the given scope. If right operand is universal,
1544 -- check the other operand. In the case of concatenation, either
1545 -- argument can be the component type, so check the type of the result.
1546 -- If both arguments are literals, look for a type of the right kind
1547 -- defined in the given scope. This elaborate nonsense is brought to
1548 -- you courtesy of b33302a. The type itself must be frozen, so we must
1549 -- find the type of the proper class in the given scope.
1551 -- A final wrinkle is the multiplication operator for fixed point types,
1552 -- which is defined in Standard only, and not in the scope of the
1553 -- fixed point type itself.
1555 if Nkind (Name (N)) = N_Expanded_Name then
1556 Pack := Entity (Prefix (Name (N)));
1558 -- If this is a package renaming, get renamed entity, which will be
1559 -- the scope of the operands if operaton is type-correct.
1561 if Present (Renamed_Entity (Pack)) then
1562 Pack := Renamed_Entity (Pack);
1565 -- If the entity being called is defined in the given package, it is
1566 -- a renaming of a predefined operator, and known to be legal.
1568 if Scope (Entity (Name (N))) = Pack
1569 and then Pack /= Standard_Standard
1573 -- Visibility does not need to be checked in an instance: if the
1574 -- operator was not visible in the generic it has been diagnosed
1575 -- already, else there is an implicit copy of it in the instance.
1577 elsif In_Instance then
1580 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1581 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1582 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1584 if Pack /= Standard_Standard then
1588 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1591 elsif Ada_Version >= Ada_2005
1592 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1593 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1598 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1600 if Op_Name = Name_Op_Concat then
1601 Opnd_Type := Base_Type (Typ);
1603 elsif (Scope (Opnd_Type) = Standard_Standard
1605 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1607 and then not Comes_From_Source (Opnd_Type))
1609 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1612 if Scope (Opnd_Type) = Standard_Standard then
1614 -- Verify that the scope contains a type that corresponds to
1615 -- the given literal. Optimize the case where Pack is Standard.
1617 if Pack /= Standard_Standard then
1619 if Opnd_Type = Universal_Integer then
1620 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1622 elsif Opnd_Type = Universal_Real then
1623 Orig_Type := Type_In_P (Is_Real_Type'Access);
1625 elsif Opnd_Type = Any_String then
1626 Orig_Type := Type_In_P (Is_String_Type'Access);
1628 elsif Opnd_Type = Any_Access then
1629 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1631 elsif Opnd_Type = Any_Composite then
1632 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1634 if Present (Orig_Type) then
1635 if Has_Private_Component (Orig_Type) then
1638 Set_Etype (Act1, Orig_Type);
1641 Set_Etype (Act2, Orig_Type);
1650 Error := No (Orig_Type);
1653 elsif Ekind (Opnd_Type) = E_Allocator_Type
1654 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1658 -- If the type is defined elsewhere, and the operator is not
1659 -- defined in the given scope (by a renaming declaration, e.g.)
1660 -- then this is an error as well. If an extension of System is
1661 -- present, and the type may be defined there, Pack must be
1664 elsif Scope (Opnd_Type) /= Pack
1665 and then Scope (Op_Id) /= Pack
1666 and then (No (System_Aux_Id)
1667 or else Scope (Opnd_Type) /= System_Aux_Id
1668 or else Pack /= Scope (System_Aux_Id))
1670 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1673 Error := not Operand_Type_In_Scope (Pack);
1676 elsif Pack = Standard_Standard
1677 and then not Operand_Type_In_Scope (Standard_Standard)
1684 Error_Msg_Node_2 := Pack;
1686 ("& not declared in&", N, Selector_Name (Name (N)));
1687 Set_Etype (N, Any_Type);
1690 -- Detect a mismatch between the context type and the result type
1691 -- in the named package, which is otherwise not detected if the
1692 -- operands are universal. Check is only needed if source entity is
1693 -- an operator, not a function that renames an operator.
1695 elsif Nkind (Parent (N)) /= N_Type_Conversion
1696 and then Ekind (Entity (Name (N))) = E_Operator
1697 and then Is_Numeric_Type (Typ)
1698 and then not Is_Universal_Numeric_Type (Typ)
1699 and then Scope (Base_Type (Typ)) /= Pack
1700 and then not In_Instance
1702 if Is_Fixed_Point_Type (Typ)
1703 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1705 -- Already checked above
1709 -- Operator may be defined in an extension of System
1711 elsif Present (System_Aux_Id)
1712 and then Scope (Opnd_Type) = System_Aux_Id
1717 -- Could we use Wrong_Type here??? (this would require setting
1718 -- Etype (N) to the actual type found where Typ was expected).
1720 Error_Msg_NE ("expect }", N, Typ);
1725 Set_Chars (Op_Node, Op_Name);
1727 if not Is_Private_Type (Etype (N)) then
1728 Set_Etype (Op_Node, Base_Type (Etype (N)));
1730 Set_Etype (Op_Node, Etype (N));
1733 -- If this is a call to a function that renames a predefined equality,
1734 -- the renaming declaration provides a type that must be used to
1735 -- resolve the operands. This must be done now because resolution of
1736 -- the equality node will not resolve any remaining ambiguity, and it
1737 -- assumes that the first operand is not overloaded.
1739 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1740 and then Ekind (Func) = E_Function
1741 and then Is_Overloaded (Act1)
1743 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1744 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1747 Set_Entity (Op_Node, Op_Id);
1748 Generate_Reference (Op_Id, N, ' ');
1750 -- Do rewrite setting Comes_From_Source on the result if the original
1751 -- call came from source. Although it is not strictly the case that the
1752 -- operator as such comes from the source, logically it corresponds
1753 -- exactly to the function call in the source, so it should be marked
1754 -- this way (e.g. to make sure that validity checks work fine).
1757 CS : constant Boolean := Comes_From_Source (N);
1759 Rewrite (N, Op_Node);
1760 Set_Comes_From_Source (N, CS);
1763 -- If this is an arithmetic operator and the result type is private,
1764 -- the operands and the result must be wrapped in conversion to
1765 -- expose the underlying numeric type and expand the proper checks,
1766 -- e.g. on division.
1768 if Is_Private_Type (Typ) then
1770 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1771 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1772 Resolve_Intrinsic_Operator (N, Typ);
1774 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1775 Resolve_Intrinsic_Unary_Operator (N, Typ);
1784 -- If in ASIS_Mode, propagate operand types to original actuals of
1785 -- function call, which would otherwise not be fully resolved. If
1786 -- the call has already been constant-folded, nothing to do. We
1787 -- relocate the operand nodes rather than copy them, to preserve
1788 -- original_node pointers, given that the operands themselves may
1789 -- have been rewritten. If the call was itself a rewriting of an
1790 -- operator node, nothing to do.
1793 and then Nkind (N) in N_Op
1794 and then Nkind (Original_Node (N)) = N_Function_Call
1798 R : constant Node_Id := Right_Opnd (N);
1800 Old_First : constant Node_Id :=
1801 First (Parameter_Associations (Original_Node (N)));
1807 Old_Sec := Next (Old_First);
1809 -- If the original call has named associations, replace the
1810 -- explicit actual parameter in the association with the proper
1811 -- resolved operand.
1813 if Nkind (Old_First) = N_Parameter_Association then
1814 if Chars (Selector_Name (Old_First)) =
1815 Chars (First_Entity (Op_Id))
1817 Rewrite (Explicit_Actual_Parameter (Old_First),
1820 Rewrite (Explicit_Actual_Parameter (Old_First),
1825 Rewrite (Old_First, Relocate_Node (L));
1828 if Nkind (Old_Sec) = N_Parameter_Association then
1829 if Chars (Selector_Name (Old_Sec)) =
1830 Chars (First_Entity (Op_Id))
1832 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1835 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1840 Rewrite (Old_Sec, Relocate_Node (R));
1844 if Nkind (Old_First) = N_Parameter_Association then
1845 Rewrite (Explicit_Actual_Parameter (Old_First),
1848 Rewrite (Old_First, Relocate_Node (R));
1853 Set_Parent (Original_Node (N), Parent (N));
1855 end Make_Call_Into_Operator;
1861 function Operator_Kind
1863 Is_Binary : Boolean) return Node_Kind
1868 -- Use CASE statement or array???
1871 if Op_Name = Name_Op_And then
1873 elsif Op_Name = Name_Op_Or then
1875 elsif Op_Name = Name_Op_Xor then
1877 elsif Op_Name = Name_Op_Eq then
1879 elsif Op_Name = Name_Op_Ne then
1881 elsif Op_Name = Name_Op_Lt then
1883 elsif Op_Name = Name_Op_Le then
1885 elsif Op_Name = Name_Op_Gt then
1887 elsif Op_Name = Name_Op_Ge then
1889 elsif Op_Name = Name_Op_Add then
1891 elsif Op_Name = Name_Op_Subtract then
1892 Kind := N_Op_Subtract;
1893 elsif Op_Name = Name_Op_Concat then
1894 Kind := N_Op_Concat;
1895 elsif Op_Name = Name_Op_Multiply then
1896 Kind := N_Op_Multiply;
1897 elsif Op_Name = Name_Op_Divide then
1898 Kind := N_Op_Divide;
1899 elsif Op_Name = Name_Op_Mod then
1901 elsif Op_Name = Name_Op_Rem then
1903 elsif Op_Name = Name_Op_Expon then
1906 raise Program_Error;
1912 if Op_Name = Name_Op_Add then
1914 elsif Op_Name = Name_Op_Subtract then
1916 elsif Op_Name = Name_Op_Abs then
1918 elsif Op_Name = Name_Op_Not then
1921 raise Program_Error;
1928 ----------------------------
1929 -- Preanalyze_And_Resolve --
1930 ----------------------------
1932 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1933 Save_Full_Analysis : constant Boolean := Full_Analysis;
1936 Full_Analysis := False;
1937 Expander_Mode_Save_And_Set (False);
1939 -- Normally, we suppress all checks for this preanalysis. There is no
1940 -- point in processing them now, since they will be applied properly
1941 -- and in the proper location when the default expressions reanalyzed
1942 -- and reexpanded later on. We will also have more information at that
1943 -- point for possible suppression of individual checks.
1945 -- However, in SPARK mode, most expansion is suppressed, and this
1946 -- later reanalysis and reexpansion may not occur. SPARK mode does
1947 -- require the setting of checking flags for proof purposes, so we
1948 -- do the SPARK preanalysis without suppressing checks.
1950 -- This special handling for SPARK mode is required for example in the
1951 -- case of Ada 2012 constructs such as quantified expressions, which are
1952 -- expanded in two separate steps.
1954 if GNATprove_Mode then
1955 Analyze_And_Resolve (N, T);
1957 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1960 Expander_Mode_Restore;
1961 Full_Analysis := Save_Full_Analysis;
1962 end Preanalyze_And_Resolve;
1964 -- Version without context type
1966 procedure Preanalyze_And_Resolve (N : Node_Id) is
1967 Save_Full_Analysis : constant Boolean := Full_Analysis;
1970 Full_Analysis := False;
1971 Expander_Mode_Save_And_Set (False);
1974 Resolve (N, Etype (N), Suppress => All_Checks);
1976 Expander_Mode_Restore;
1977 Full_Analysis := Save_Full_Analysis;
1978 end Preanalyze_And_Resolve;
1980 ----------------------------------
1981 -- Replace_Actual_Discriminants --
1982 ----------------------------------
1984 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1985 Loc : constant Source_Ptr := Sloc (N);
1986 Tsk : Node_Id := Empty;
1988 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1989 -- Comment needed???
1995 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1999 if Nkind (Nod) = N_Identifier then
2000 Ent := Entity (Nod);
2003 and then Ekind (Ent) = E_Discriminant
2006 Make_Selected_Component (Loc,
2007 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
2008 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
2010 Set_Etype (Nod, Etype (Ent));
2018 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
2020 -- Start of processing for Replace_Actual_Discriminants
2023 if not Expander_Active then
2027 if Nkind (Name (N)) = N_Selected_Component then
2028 Tsk := Prefix (Name (N));
2030 elsif Nkind (Name (N)) = N_Indexed_Component then
2031 Tsk := Prefix (Prefix (Name (N)));
2037 Replace_Discrs (Default);
2039 end Replace_Actual_Discriminants;
2045 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
2046 Ambiguous : Boolean := False;
2047 Ctx_Type : Entity_Id := Typ;
2048 Expr_Type : Entity_Id := Empty; -- prevent junk warning
2049 Err_Type : Entity_Id := Empty;
2050 Found : Boolean := False;
2053 I1 : Interp_Index := 0; -- prevent junk warning
2056 Seen : Entity_Id := Empty; -- prevent junk warning
2058 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
2059 -- Determine whether a node comes from a predefined library unit or
2062 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
2063 -- Try and fix up a literal so that it matches its expected type. New
2064 -- literals are manufactured if necessary to avoid cascaded errors.
2066 procedure Report_Ambiguous_Argument;
2067 -- Additional diagnostics when an ambiguous call has an ambiguous
2068 -- argument (typically a controlling actual).
2070 procedure Resolution_Failed;
2071 -- Called when attempt at resolving current expression fails
2073 ------------------------------------
2074 -- Comes_From_Predefined_Lib_Unit --
2075 -------------------------------------
2077 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
2080 Sloc (Nod) = Standard_Location
2081 or else Is_Predefined_File_Name
2082 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
2083 end Comes_From_Predefined_Lib_Unit;
2085 --------------------
2086 -- Patch_Up_Value --
2087 --------------------
2089 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
2091 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
2093 Make_Real_Literal (Sloc (N),
2094 Realval => UR_From_Uint (Intval (N))));
2095 Set_Etype (N, Universal_Real);
2096 Set_Is_Static_Expression (N);
2098 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
2100 Make_Integer_Literal (Sloc (N),
2101 Intval => UR_To_Uint (Realval (N))));
2102 Set_Etype (N, Universal_Integer);
2103 Set_Is_Static_Expression (N);
2105 elsif Nkind (N) = N_String_Literal
2106 and then Is_Character_Type (Typ)
2108 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
2110 Make_Character_Literal (Sloc (N),
2112 Char_Literal_Value =>
2113 UI_From_Int (Character'Pos ('A'))));
2114 Set_Etype (N, Any_Character);
2115 Set_Is_Static_Expression (N);
2117 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
2119 Make_String_Literal (Sloc (N),
2120 Strval => End_String));
2122 elsif Nkind (N) = N_Range then
2123 Patch_Up_Value (Low_Bound (N), Typ);
2124 Patch_Up_Value (High_Bound (N), Typ);
2128 -------------------------------
2129 -- Report_Ambiguous_Argument --
2130 -------------------------------
2132 procedure Report_Ambiguous_Argument is
2133 Arg : constant Node_Id := First (Parameter_Associations (N));
2138 if Nkind (Arg) = N_Function_Call
2139 and then Is_Entity_Name (Name (Arg))
2140 and then Is_Overloaded (Name (Arg))
2142 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
2144 -- Could use comments on what is going on here???
2146 Get_First_Interp (Name (Arg), I, It);
2147 while Present (It.Nam) loop
2148 Error_Msg_Sloc := Sloc (It.Nam);
2150 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
2151 Error_Msg_N ("interpretation (inherited) #!", Arg);
2153 Error_Msg_N ("interpretation #!", Arg);
2156 Get_Next_Interp (I, It);
2159 end Report_Ambiguous_Argument;
2161 -----------------------
2162 -- Resolution_Failed --
2163 -----------------------
2165 procedure Resolution_Failed is
2167 Patch_Up_Value (N, Typ);
2169 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
2170 Set_Is_Overloaded (N, False);
2172 -- The caller will return without calling the expander, so we need
2173 -- to set the analyzed flag. Note that it is fine to set Analyzed
2174 -- to True even if we are in the middle of a shallow analysis,
2175 -- (see the spec of sem for more details) since this is an error
2176 -- situation anyway, and there is no point in repeating the
2177 -- analysis later (indeed it won't work to repeat it later, since
2178 -- we haven't got a clear resolution of which entity is being
2181 Set_Analyzed (N, True);
2183 end Resolution_Failed;
2185 -- Start of processing for Resolve
2192 -- Access attribute on remote subprogram cannot be used for a non-remote
2193 -- access-to-subprogram type.
2195 if Nkind (N) = N_Attribute_Reference
2196 and then Nam_In (Attribute_Name (N), Name_Access,
2197 Name_Unrestricted_Access,
2198 Name_Unchecked_Access)
2199 and then Comes_From_Source (N)
2200 and then Is_Entity_Name (Prefix (N))
2201 and then Is_Subprogram (Entity (Prefix (N)))
2202 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2203 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2206 ("prefix must statically denote a non-remote subprogram", N);
2209 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2211 -- If the context is a Remote_Access_To_Subprogram, access attributes
2212 -- must be resolved with the corresponding fat pointer. There is no need
2213 -- to check for the attribute name since the return type of an
2214 -- attribute is never a remote type.
2216 if Nkind (N) = N_Attribute_Reference
2217 and then Comes_From_Source (N)
2218 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2221 Attr : constant Attribute_Id :=
2222 Get_Attribute_Id (Attribute_Name (N));
2223 Pref : constant Node_Id := Prefix (N);
2226 Is_Remote : Boolean := True;
2229 -- Check that Typ is a remote access-to-subprogram type
2231 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2233 -- Prefix (N) must statically denote a remote subprogram
2234 -- declared in a package specification.
2236 if Attr = Attribute_Access or else
2237 Attr = Attribute_Unchecked_Access or else
2238 Attr = Attribute_Unrestricted_Access
2240 Decl := Unit_Declaration_Node (Entity (Pref));
2242 if Nkind (Decl) = N_Subprogram_Body then
2243 Spec := Corresponding_Spec (Decl);
2245 if Present (Spec) then
2246 Decl := Unit_Declaration_Node (Spec);
2250 Spec := Parent (Decl);
2252 if not Is_Entity_Name (Prefix (N))
2253 or else Nkind (Spec) /= N_Package_Specification
2255 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2259 ("prefix must statically denote a remote subprogram ",
2263 -- If we are generating code in distributed mode, perform
2264 -- semantic checks against corresponding remote entities.
2267 and then Get_PCS_Name /= Name_No_DSA
2269 Check_Subtype_Conformant
2270 (New_Id => Entity (Prefix (N)),
2271 Old_Id => Designated_Type
2272 (Corresponding_Remote_Type (Typ)),
2276 Process_Remote_AST_Attribute (N, Typ);
2284 Debug_A_Entry ("resolving ", N);
2286 if Debug_Flag_V then
2287 Write_Overloads (N);
2290 if Comes_From_Source (N) then
2291 if Is_Fixed_Point_Type (Typ) then
2292 Check_Restriction (No_Fixed_Point, N);
2294 elsif Is_Floating_Point_Type (Typ)
2295 and then Typ /= Universal_Real
2296 and then Typ /= Any_Real
2298 Check_Restriction (No_Floating_Point, N);
2302 -- Return if already analyzed
2304 if Analyzed (N) then
2305 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2306 Analyze_Dimension (N);
2309 -- Any case of Any_Type as the Etype value means that we had a
2312 elsif Etype (N) = Any_Type then
2313 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2317 Check_Parameterless_Call (N);
2319 -- The resolution of an Expression_With_Actions is determined by
2322 if Nkind (N) = N_Expression_With_Actions then
2323 Resolve (Expression (N), Typ);
2326 Expr_Type := Etype (Expression (N));
2328 -- If not overloaded, then we know the type, and all that needs doing
2329 -- is to check that this type is compatible with the context.
2331 elsif not Is_Overloaded (N) then
2332 Found := Covers (Typ, Etype (N));
2333 Expr_Type := Etype (N);
2335 -- In the overloaded case, we must select the interpretation that
2336 -- is compatible with the context (i.e. the type passed to Resolve)
2339 -- Loop through possible interpretations
2341 Get_First_Interp (N, I, It);
2342 Interp_Loop : while Present (It.Typ) loop
2344 if Debug_Flag_V then
2345 Write_Str ("Interp: ");
2349 -- We are only interested in interpretations that are compatible
2350 -- with the expected type, any other interpretations are ignored.
2352 if not Covers (Typ, It.Typ) then
2353 if Debug_Flag_V then
2354 Write_Str (" interpretation incompatible with context");
2359 -- Skip the current interpretation if it is disabled by an
2360 -- abstract operator. This action is performed only when the
2361 -- type against which we are resolving is the same as the
2362 -- type of the interpretation.
2364 if Ada_Version >= Ada_2005
2365 and then It.Typ = Typ
2366 and then Typ /= Universal_Integer
2367 and then Typ /= Universal_Real
2368 and then Present (It.Abstract_Op)
2370 if Debug_Flag_V then
2371 Write_Line ("Skip.");
2377 -- First matching interpretation
2383 Expr_Type := It.Typ;
2385 -- Matching interpretation that is not the first, maybe an
2386 -- error, but there are some cases where preference rules are
2387 -- used to choose between the two possibilities. These and
2388 -- some more obscure cases are handled in Disambiguate.
2391 -- If the current statement is part of a predefined library
2392 -- unit, then all interpretations which come from user level
2393 -- packages should not be considered. Check previous and
2397 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2400 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2402 -- Previous interpretation must be discarded
2406 Expr_Type := It.Typ;
2407 Set_Entity (N, Seen);
2412 -- Otherwise apply further disambiguation steps
2414 Error_Msg_Sloc := Sloc (Seen);
2415 It1 := Disambiguate (N, I1, I, Typ);
2417 -- Disambiguation has succeeded. Skip the remaining
2420 if It1 /= No_Interp then
2422 Expr_Type := It1.Typ;
2424 while Present (It.Typ) loop
2425 Get_Next_Interp (I, It);
2429 -- Before we issue an ambiguity complaint, check for
2430 -- the case of a subprogram call where at least one
2431 -- of the arguments is Any_Type, and if so, suppress
2432 -- the message, since it is a cascaded error.
2434 if Nkind (N) in N_Subprogram_Call then
2440 A := First_Actual (N);
2441 while Present (A) loop
2444 if Nkind (E) = N_Parameter_Association then
2445 E := Explicit_Actual_Parameter (E);
2448 if Etype (E) = Any_Type then
2449 if Debug_Flag_V then
2450 Write_Str ("Any_Type in call");
2461 elsif Nkind (N) in N_Binary_Op
2462 and then (Etype (Left_Opnd (N)) = Any_Type
2463 or else Etype (Right_Opnd (N)) = Any_Type)
2467 elsif Nkind (N) in N_Unary_Op
2468 and then Etype (Right_Opnd (N)) = Any_Type
2473 -- Not that special case, so issue message using the
2474 -- flag Ambiguous to control printing of the header
2475 -- message only at the start of an ambiguous set.
2477 if not Ambiguous then
2478 if Nkind (N) = N_Function_Call
2479 and then Nkind (Name (N)) = N_Explicit_Dereference
2482 ("ambiguous expression "
2483 & "(cannot resolve indirect call)!", N);
2485 Error_Msg_NE -- CODEFIX
2486 ("ambiguous expression (cannot resolve&)!",
2492 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2494 ("\\possible interpretation (inherited)#!", N);
2496 Error_Msg_N -- CODEFIX
2497 ("\\possible interpretation#!", N);
2500 if Nkind (N) in N_Subprogram_Call
2501 and then Present (Parameter_Associations (N))
2503 Report_Ambiguous_Argument;
2507 Error_Msg_Sloc := Sloc (It.Nam);
2509 -- By default, the error message refers to the candidate
2510 -- interpretation. But if it is a predefined operator, it
2511 -- is implicitly declared at the declaration of the type
2512 -- of the operand. Recover the sloc of that declaration
2513 -- for the error message.
2515 if Nkind (N) in N_Op
2516 and then Scope (It.Nam) = Standard_Standard
2517 and then not Is_Overloaded (Right_Opnd (N))
2518 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2521 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2523 if Comes_From_Source (Err_Type)
2524 and then Present (Parent (Err_Type))
2526 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2529 elsif Nkind (N) in N_Binary_Op
2530 and then Scope (It.Nam) = Standard_Standard
2531 and then not Is_Overloaded (Left_Opnd (N))
2532 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2535 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2537 if Comes_From_Source (Err_Type)
2538 and then Present (Parent (Err_Type))
2540 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2543 -- If this is an indirect call, use the subprogram_type
2544 -- in the message, to have a meaningful location. Also
2545 -- indicate if this is an inherited operation, created
2546 -- by a type declaration.
2548 elsif Nkind (N) = N_Function_Call
2549 and then Nkind (Name (N)) = N_Explicit_Dereference
2550 and then Is_Type (It.Nam)
2554 Sloc (Associated_Node_For_Itype (Err_Type));
2559 if Nkind (N) in N_Op
2560 and then Scope (It.Nam) = Standard_Standard
2561 and then Present (Err_Type)
2563 -- Special-case the message for universal_fixed
2564 -- operators, which are not declared with the type
2565 -- of the operand, but appear forever in Standard.
2567 if It.Typ = Universal_Fixed
2568 and then Scope (It.Nam) = Standard_Standard
2571 ("\\possible interpretation as universal_fixed "
2572 & "operation (RM 4.5.5 (19))", N);
2575 ("\\possible interpretation (predefined)#!", N);
2579 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2582 ("\\possible interpretation (inherited)#!", N);
2584 Error_Msg_N -- CODEFIX
2585 ("\\possible interpretation#!", N);
2591 -- We have a matching interpretation, Expr_Type is the type
2592 -- from this interpretation, and Seen is the entity.
2594 -- For an operator, just set the entity name. The type will be
2595 -- set by the specific operator resolution routine.
2597 if Nkind (N) in N_Op then
2598 Set_Entity (N, Seen);
2599 Generate_Reference (Seen, N);
2601 elsif Nkind (N) = N_Case_Expression then
2602 Set_Etype (N, Expr_Type);
2604 elsif Nkind (N) = N_Character_Literal then
2605 Set_Etype (N, Expr_Type);
2607 elsif Nkind (N) = N_If_Expression then
2608 Set_Etype (N, Expr_Type);
2610 -- AI05-0139-2: Expression is overloaded because type has
2611 -- implicit dereference. If type matches context, no implicit
2612 -- dereference is involved.
2614 elsif Has_Implicit_Dereference (Expr_Type) then
2615 Set_Etype (N, Expr_Type);
2616 Set_Is_Overloaded (N, False);
2619 elsif Is_Overloaded (N)
2620 and then Present (It.Nam)
2621 and then Ekind (It.Nam) = E_Discriminant
2622 and then Has_Implicit_Dereference (It.Nam)
2624 -- If the node is a general indexing, the dereference is
2625 -- is inserted when resolving the rewritten form, else
2628 if Nkind (N) /= N_Indexed_Component
2629 or else No (Generalized_Indexing (N))
2631 Build_Explicit_Dereference (N, It.Nam);
2634 -- For an explicit dereference, attribute reference, range,
2635 -- short-circuit form (which is not an operator node), or call
2636 -- with a name that is an explicit dereference, there is
2637 -- nothing to be done at this point.
2639 elsif Nkind_In (N, N_Explicit_Dereference,
2640 N_Attribute_Reference,
2642 N_Indexed_Component,
2645 N_Selected_Component,
2647 or else Nkind (Name (N)) = N_Explicit_Dereference
2651 -- For procedure or function calls, set the type of the name,
2652 -- and also the entity pointer for the prefix.
2654 elsif Nkind (N) in N_Subprogram_Call
2655 and then Is_Entity_Name (Name (N))
2657 Set_Etype (Name (N), Expr_Type);
2658 Set_Entity (Name (N), Seen);
2659 Generate_Reference (Seen, Name (N));
2661 elsif Nkind (N) = N_Function_Call
2662 and then Nkind (Name (N)) = N_Selected_Component
2664 Set_Etype (Name (N), Expr_Type);
2665 Set_Entity (Selector_Name (Name (N)), Seen);
2666 Generate_Reference (Seen, Selector_Name (Name (N)));
2668 -- For all other cases, just set the type of the Name
2671 Set_Etype (Name (N), Expr_Type);
2678 -- Move to next interpretation
2680 exit Interp_Loop when No (It.Typ);
2682 Get_Next_Interp (I, It);
2683 end loop Interp_Loop;
2686 -- At this stage Found indicates whether or not an acceptable
2687 -- interpretation exists. If not, then we have an error, except that if
2688 -- the context is Any_Type as a result of some other error, then we
2689 -- suppress the error report.
2692 if Typ /= Any_Type then
2694 -- If type we are looking for is Void, then this is the procedure
2695 -- call case, and the error is simply that what we gave is not a
2696 -- procedure name (we think of procedure calls as expressions with
2697 -- types internally, but the user doesn't think of them this way).
2699 if Typ = Standard_Void_Type then
2701 -- Special case message if function used as a procedure
2703 if Nkind (N) = N_Procedure_Call_Statement
2704 and then Is_Entity_Name (Name (N))
2705 and then Ekind (Entity (Name (N))) = E_Function
2708 ("cannot use function & in a procedure call",
2709 Name (N), Entity (Name (N)));
2711 -- Otherwise give general message (not clear what cases this
2712 -- covers, but no harm in providing for them).
2715 Error_Msg_N ("expect procedure name in procedure call", N);
2720 -- Otherwise we do have a subexpression with the wrong type
2722 -- Check for the case of an allocator which uses an access type
2723 -- instead of the designated type. This is a common error and we
2724 -- specialize the message, posting an error on the operand of the
2725 -- allocator, complaining that we expected the designated type of
2728 elsif Nkind (N) = N_Allocator
2729 and then Is_Access_Type (Typ)
2730 and then Is_Access_Type (Etype (N))
2731 and then Designated_Type (Etype (N)) = Typ
2733 Wrong_Type (Expression (N), Designated_Type (Typ));
2736 -- Check for view mismatch on Null in instances, for which the
2737 -- view-swapping mechanism has no identifier.
2739 elsif (In_Instance or else In_Inlined_Body)
2740 and then (Nkind (N) = N_Null)
2741 and then Is_Private_Type (Typ)
2742 and then Is_Access_Type (Full_View (Typ))
2744 Resolve (N, Full_View (Typ));
2748 -- Check for an aggregate. Sometimes we can get bogus aggregates
2749 -- from misuse of parentheses, and we are about to complain about
2750 -- the aggregate without even looking inside it.
2752 -- Instead, if we have an aggregate of type Any_Composite, then
2753 -- analyze and resolve the component fields, and then only issue
2754 -- another message if we get no errors doing this (otherwise
2755 -- assume that the errors in the aggregate caused the problem).
2757 elsif Nkind (N) = N_Aggregate
2758 and then Etype (N) = Any_Composite
2760 -- Disable expansion in any case. If there is a type mismatch
2761 -- it may be fatal to try to expand the aggregate. The flag
2762 -- would otherwise be set to false when the error is posted.
2764 Expander_Active := False;
2767 procedure Check_Aggr (Aggr : Node_Id);
2768 -- Check one aggregate, and set Found to True if we have a
2769 -- definite error in any of its elements
2771 procedure Check_Elmt (Aelmt : Node_Id);
2772 -- Check one element of aggregate and set Found to True if
2773 -- we definitely have an error in the element.
2779 procedure Check_Aggr (Aggr : Node_Id) is
2783 if Present (Expressions (Aggr)) then
2784 Elmt := First (Expressions (Aggr));
2785 while Present (Elmt) loop
2791 if Present (Component_Associations (Aggr)) then
2792 Elmt := First (Component_Associations (Aggr));
2793 while Present (Elmt) loop
2795 -- If this is a default-initialized component, then
2796 -- there is nothing to check. The box will be
2797 -- replaced by the appropriate call during late
2800 if not Box_Present (Elmt) then
2801 Check_Elmt (Expression (Elmt));
2813 procedure Check_Elmt (Aelmt : Node_Id) is
2815 -- If we have a nested aggregate, go inside it (to
2816 -- attempt a naked analyze-resolve of the aggregate can
2817 -- cause undesirable cascaded errors). Do not resolve
2818 -- expression if it needs a type from context, as for
2819 -- integer * fixed expression.
2821 if Nkind (Aelmt) = N_Aggregate then
2827 if not Is_Overloaded (Aelmt)
2828 and then Etype (Aelmt) /= Any_Fixed
2833 if Etype (Aelmt) = Any_Type then
2844 -- Looks like we have a type error, but check for special case
2845 -- of Address wanted, integer found, with the configuration pragma
2846 -- Allow_Integer_Address active. If we have this case, introduce
2847 -- an unchecked conversion to allow the integer expression to be
2848 -- treated as an Address. The reverse case of integer wanted,
2849 -- Address found, is treated in an analogous manner.
2851 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2852 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2853 Analyze_And_Resolve (N, Typ);
2857 -- That special Allow_Integer_Address check did not appply, so we
2858 -- have a real type error. If an error message was issued already,
2859 -- Found got reset to True, so if it's still False, issue standard
2860 -- Wrong_Type message.
2863 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2865 Subp_Name : Node_Id;
2868 if Is_Entity_Name (Name (N)) then
2869 Subp_Name := Name (N);
2871 elsif Nkind (Name (N)) = N_Selected_Component then
2873 -- Protected operation: retrieve operation name
2875 Subp_Name := Selector_Name (Name (N));
2878 raise Program_Error;
2881 Error_Msg_Node_2 := Typ;
2883 ("no visible interpretation of& "
2884 & "matches expected type&", N, Subp_Name);
2887 if All_Errors_Mode then
2889 Index : Interp_Index;
2893 Error_Msg_N ("\\possible interpretations:", N);
2895 Get_First_Interp (Name (N), Index, It);
2896 while Present (It.Nam) loop
2897 Error_Msg_Sloc := Sloc (It.Nam);
2898 Error_Msg_Node_2 := It.Nam;
2900 ("\\ type& for & declared#", N, It.Typ);
2901 Get_Next_Interp (Index, It);
2906 Error_Msg_N ("\use -gnatf for details", N);
2910 Wrong_Type (N, Typ);
2918 -- Test if we have more than one interpretation for the context
2920 elsif Ambiguous then
2924 -- Only one intepretation
2927 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2928 -- the "+" on T is abstract, and the operands are of universal type,
2929 -- the above code will have (incorrectly) resolved the "+" to the
2930 -- universal one in Standard. Therefore check for this case and give
2931 -- an error. We can't do this earlier, because it would cause legal
2932 -- cases to get errors (when some other type has an abstract "+").
2934 if Ada_Version >= Ada_2005
2935 and then Nkind (N) in N_Op
2936 and then Is_Overloaded (N)
2937 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2939 Get_First_Interp (N, I, It);
2940 while Present (It.Typ) loop
2941 if Present (It.Abstract_Op) and then
2942 Etype (It.Abstract_Op) = Typ
2945 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2949 Get_Next_Interp (I, It);
2953 -- Here we have an acceptable interpretation for the context
2955 -- Propagate type information and normalize tree for various
2956 -- predefined operations. If the context only imposes a class of
2957 -- types, rather than a specific type, propagate the actual type
2960 if Typ = Any_Integer or else
2961 Typ = Any_Boolean or else
2962 Typ = Any_Modular or else
2963 Typ = Any_Real or else
2966 Ctx_Type := Expr_Type;
2968 -- Any_Fixed is legal in a real context only if a specific fixed-
2969 -- point type is imposed. If Norman Cohen can be confused by this,
2970 -- it deserves a separate message.
2973 and then Expr_Type = Any_Fixed
2975 Error_Msg_N ("illegal context for mixed mode operation", N);
2976 Set_Etype (N, Universal_Real);
2977 Ctx_Type := Universal_Real;
2981 -- A user-defined operator is transformed into a function call at
2982 -- this point, so that further processing knows that operators are
2983 -- really operators (i.e. are predefined operators). User-defined
2984 -- operators that are intrinsic are just renamings of the predefined
2985 -- ones, and need not be turned into calls either, but if they rename
2986 -- a different operator, we must transform the node accordingly.
2987 -- Instantiations of Unchecked_Conversion are intrinsic but are
2988 -- treated as functions, even if given an operator designator.
2990 if Nkind (N) in N_Op
2991 and then Present (Entity (N))
2992 and then Ekind (Entity (N)) /= E_Operator
2995 if not Is_Predefined_Op (Entity (N)) then
2996 Rewrite_Operator_As_Call (N, Entity (N));
2998 elsif Present (Alias (Entity (N)))
3000 Nkind (Parent (Parent (Entity (N)))) =
3001 N_Subprogram_Renaming_Declaration
3003 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
3005 -- If the node is rewritten, it will be fully resolved in
3006 -- Rewrite_Renamed_Operator.
3008 if Analyzed (N) then
3014 case N_Subexpr'(Nkind (N)) is
3016 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
3018 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
3020 when N_Short_Circuit
3021 => Resolve_Short_Circuit (N, Ctx_Type);
3023 when N_Attribute_Reference
3024 => Resolve_Attribute (N, Ctx_Type);
3026 when N_Case_Expression
3027 => Resolve_Case_Expression (N, Ctx_Type);
3029 when N_Character_Literal
3030 => Resolve_Character_Literal (N, Ctx_Type);
3032 when N_Expanded_Name
3033 => Resolve_Entity_Name (N, Ctx_Type);
3035 when N_Explicit_Dereference
3036 => Resolve_Explicit_Dereference (N, Ctx_Type);
3038 when N_Expression_With_Actions
3039 => Resolve_Expression_With_Actions (N, Ctx_Type);
3041 when N_Extension_Aggregate
3042 => Resolve_Extension_Aggregate (N, Ctx_Type);
3044 when N_Function_Call
3045 => Resolve_Call (N, Ctx_Type);
3048 => Resolve_Entity_Name (N, Ctx_Type);
3050 when N_If_Expression
3051 => Resolve_If_Expression (N, Ctx_Type);
3053 when N_Indexed_Component
3054 => Resolve_Indexed_Component (N, Ctx_Type);
3056 when N_Integer_Literal
3057 => Resolve_Integer_Literal (N, Ctx_Type);
3059 when N_Membership_Test
3060 => Resolve_Membership_Op (N, Ctx_Type);
3062 when N_Null => Resolve_Null (N, Ctx_Type);
3064 when N_Op_And | N_Op_Or | N_Op_Xor
3065 => Resolve_Logical_Op (N, Ctx_Type);
3067 when N_Op_Eq | N_Op_Ne
3068 => Resolve_Equality_Op (N, Ctx_Type);
3070 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
3071 => Resolve_Comparison_Op (N, Ctx_Type);
3073 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
3075 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
3076 N_Op_Divide | N_Op_Mod | N_Op_Rem
3078 => Resolve_Arithmetic_Op (N, Ctx_Type);
3080 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
3082 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
3084 when N_Op_Plus | N_Op_Minus | N_Op_Abs
3085 => Resolve_Unary_Op (N, Ctx_Type);
3087 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
3089 when N_Procedure_Call_Statement
3090 => Resolve_Call (N, Ctx_Type);
3092 when N_Operator_Symbol
3093 => Resolve_Operator_Symbol (N, Ctx_Type);
3095 when N_Qualified_Expression
3096 => Resolve_Qualified_Expression (N, Ctx_Type);
3098 -- Why is the following null, needs a comment ???
3100 when N_Quantified_Expression
3103 when N_Raise_Expression
3104 => Resolve_Raise_Expression (N, Ctx_Type);
3106 when N_Raise_xxx_Error
3107 => Set_Etype (N, Ctx_Type);
3109 when N_Range => Resolve_Range (N, Ctx_Type);
3112 => Resolve_Real_Literal (N, Ctx_Type);
3114 when N_Reference => Resolve_Reference (N, Ctx_Type);
3116 when N_Selected_Component
3117 => Resolve_Selected_Component (N, Ctx_Type);
3119 when N_Slice => Resolve_Slice (N, Ctx_Type);
3121 when N_String_Literal
3122 => Resolve_String_Literal (N, Ctx_Type);
3124 when N_Type_Conversion
3125 => Resolve_Type_Conversion (N, Ctx_Type);
3127 when N_Unchecked_Expression =>
3128 Resolve_Unchecked_Expression (N, Ctx_Type);
3130 when N_Unchecked_Type_Conversion =>
3131 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
3134 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
3135 -- expression of an anonymous access type that occurs in the context
3136 -- of a named general access type, except when the expression is that
3137 -- of a membership test. This ensures proper legality checking in
3138 -- terms of allowed conversions (expressions that would be illegal to
3139 -- convert implicitly are allowed in membership tests).
3141 if Ada_Version >= Ada_2012
3142 and then Ekind (Ctx_Type) = E_General_Access_Type
3143 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3144 and then Nkind (Parent (N)) not in N_Membership_Test
3146 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3147 Analyze_And_Resolve (N, Ctx_Type);
3150 -- If the subexpression was replaced by a non-subexpression, then
3151 -- all we do is to expand it. The only legitimate case we know of
3152 -- is converting procedure call statement to entry call statements,
3153 -- but there may be others, so we are making this test general.
3155 if Nkind (N) not in N_Subexpr then
3156 Debug_A_Exit ("resolving ", N, " (done)");
3161 -- The expression is definitely NOT overloaded at this point, so
3162 -- we reset the Is_Overloaded flag to avoid any confusion when
3163 -- reanalyzing the node.
3165 Set_Is_Overloaded (N, False);
3167 -- Freeze expression type, entity if it is a name, and designated
3168 -- type if it is an allocator (RM 13.14(10,11,13)).
3170 -- Now that the resolution of the type of the node is complete, and
3171 -- we did not detect an error, we can expand this node. We skip the
3172 -- expand call if we are in a default expression, see section
3173 -- "Handling of Default Expressions" in Sem spec.
3175 Debug_A_Exit ("resolving ", N, " (done)");
3177 -- We unconditionally freeze the expression, even if we are in
3178 -- default expression mode (the Freeze_Expression routine tests this
3179 -- flag and only freezes static types if it is set).
3181 -- Ada 2012 (AI05-177): The declaration of an expression function
3182 -- does not cause freezing, but we never reach here in that case.
3183 -- Here we are resolving the corresponding expanded body, so we do
3184 -- need to perform normal freezing.
3186 Freeze_Expression (N);
3188 -- Now we can do the expansion
3198 -- Version with check(s) suppressed
3200 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3202 if Suppress = All_Checks then
3204 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3206 Scope_Suppress.Suppress := (others => True);
3208 Scope_Suppress.Suppress := Sva;
3213 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3215 Scope_Suppress.Suppress (Suppress) := True;
3217 Scope_Suppress.Suppress (Suppress) := Svg;
3226 -- Version with implicit type
3228 procedure Resolve (N : Node_Id) is
3230 Resolve (N, Etype (N));
3233 ---------------------
3234 -- Resolve_Actuals --
3235 ---------------------
3237 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3238 Loc : constant Source_Ptr := Sloc (N);
3244 Prev : Node_Id := Empty;
3247 procedure Check_Aliased_Parameter;
3248 -- Check rules on aliased parameters and related accessibility rules
3249 -- in (RM 3.10.2 (10.2-10.4)).
3251 procedure Check_Argument_Order;
3252 -- Performs a check for the case where the actuals are all simple
3253 -- identifiers that correspond to the formal names, but in the wrong
3254 -- order, which is considered suspicious and cause for a warning.
3256 procedure Check_Prefixed_Call;
3257 -- If the original node is an overloaded call in prefix notation,
3258 -- insert an 'Access or a dereference as needed over the first actual.
3259 -- Try_Object_Operation has already verified that there is a valid
3260 -- interpretation, but the form of the actual can only be determined
3261 -- once the primitive operation is identified.
3263 procedure Insert_Default;
3264 -- If the actual is missing in a call, insert in the actuals list
3265 -- an instance of the default expression. The insertion is always
3266 -- a named association.
3268 procedure Property_Error
3271 Prop_Nam : Name_Id);
3272 -- Emit an error concerning variable Var with entity Var_Id that has
3273 -- enabled property Prop_Nam when it acts as an actual parameter in a
3274 -- call and the corresponding formal parameter is of mode IN.
3276 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3277 -- Check whether T1 and T2, or their full views, are derived from a
3278 -- common type. Used to enforce the restrictions on array conversions
3281 function Static_Concatenation (N : Node_Id) return Boolean;
3282 -- Predicate to determine whether an actual that is a concatenation
3283 -- will be evaluated statically and does not need a transient scope.
3284 -- This must be determined before the actual is resolved and expanded
3285 -- because if needed the transient scope must be introduced earlier.
3287 ------------------------------
3288 -- Check_Aliased_Parameter --
3289 ------------------------------
3291 procedure Check_Aliased_Parameter is
3292 Nominal_Subt : Entity_Id;
3295 if Is_Aliased (F) then
3296 if Is_Tagged_Type (A_Typ) then
3299 elsif Is_Aliased_View (A) then
3300 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3301 Nominal_Subt := Base_Type (A_Typ);
3303 Nominal_Subt := A_Typ;
3306 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3309 -- In a generic body assume the worst for generic formals:
3310 -- they can have a constrained partial view (AI05-041).
3312 elsif Has_Discriminants (F_Typ)
3313 and then not Is_Constrained (F_Typ)
3314 and then not Has_Constrained_Partial_View (F_Typ)
3315 and then not Is_Generic_Type (F_Typ)
3320 Error_Msg_NE ("untagged actual does not match "
3321 & "aliased formal&", A, F);
3325 Error_Msg_NE ("actual for aliased formal& must be "
3326 & "aliased object", A, F);
3329 if Ekind (Nam) = E_Procedure then
3332 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3333 if Nkind (Parent (N)) = N_Type_Conversion
3334 and then Type_Access_Level (Etype (Parent (N))) <
3335 Object_Access_Level (A)
3337 Error_Msg_N ("aliased actual has wrong accessibility", A);
3340 elsif Nkind (Parent (N)) = N_Qualified_Expression
3341 and then Nkind (Parent (Parent (N))) = N_Allocator
3342 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3343 Object_Access_Level (A)
3346 ("aliased actual in allocator has wrong accessibility", A);
3349 end Check_Aliased_Parameter;
3351 --------------------------
3352 -- Check_Argument_Order --
3353 --------------------------
3355 procedure Check_Argument_Order is
3357 -- Nothing to do if no parameters, or original node is neither a
3358 -- function call nor a procedure call statement (happens in the
3359 -- operator-transformed-to-function call case), or the call does
3360 -- not come from source, or this warning is off.
3362 if not Warn_On_Parameter_Order
3363 or else No (Parameter_Associations (N))
3364 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3365 or else not Comes_From_Source (N)
3371 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3374 -- Nothing to do if only one parameter
3380 -- Here if at least two arguments
3383 Actuals : array (1 .. Nargs) of Node_Id;
3387 Wrong_Order : Boolean := False;
3388 -- Set True if an out of order case is found
3391 -- Collect identifier names of actuals, fail if any actual is
3392 -- not a simple identifier, and record max length of name.
3394 Actual := First (Parameter_Associations (N));
3395 for J in Actuals'Range loop
3396 if Nkind (Actual) /= N_Identifier then
3399 Actuals (J) := Actual;
3404 -- If we got this far, all actuals are identifiers and the list
3405 -- of their names is stored in the Actuals array.
3407 Formal := First_Formal (Nam);
3408 for J in Actuals'Range loop
3410 -- If we ran out of formals, that's odd, probably an error
3411 -- which will be detected elsewhere, but abandon the search.
3417 -- If name matches and is in order OK
3419 if Chars (Formal) = Chars (Actuals (J)) then
3423 -- If no match, see if it is elsewhere in list and if so
3424 -- flag potential wrong order if type is compatible.
3426 for K in Actuals'Range loop
3427 if Chars (Formal) = Chars (Actuals (K))
3429 Has_Compatible_Type (Actuals (K), Etype (Formal))
3431 Wrong_Order := True;
3441 <<Continue>> Next_Formal (Formal);
3444 -- If Formals left over, also probably an error, skip warning
3446 if Present (Formal) then
3450 -- Here we give the warning if something was out of order
3454 ("?P?actuals for this call may be in wrong order", N);
3458 end Check_Argument_Order;
3460 -------------------------
3461 -- Check_Prefixed_Call --
3462 -------------------------
3464 procedure Check_Prefixed_Call is
3465 Act : constant Node_Id := First_Actual (N);
3466 A_Type : constant Entity_Id := Etype (Act);
3467 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3468 Orig : constant Node_Id := Original_Node (N);
3472 -- Check whether the call is a prefixed call, with or without
3473 -- additional actuals.
3475 if Nkind (Orig) = N_Selected_Component
3477 (Nkind (Orig) = N_Indexed_Component
3478 and then Nkind (Prefix (Orig)) = N_Selected_Component
3479 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3480 and then Is_Entity_Name (Act)
3481 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3483 if Is_Access_Type (A_Type)
3484 and then not Is_Access_Type (F_Type)
3486 -- Introduce dereference on object in prefix
3489 Make_Explicit_Dereference (Sloc (Act),
3490 Prefix => Relocate_Node (Act));
3491 Rewrite (Act, New_A);
3494 elsif Is_Access_Type (F_Type)
3495 and then not Is_Access_Type (A_Type)
3497 -- Introduce an implicit 'Access in prefix
3499 if not Is_Aliased_View (Act) then
3501 ("object in prefixed call to& must be aliased "
3502 & "(RM 4.1.3 (13 1/2))",
3507 Make_Attribute_Reference (Loc,
3508 Attribute_Name => Name_Access,
3509 Prefix => Relocate_Node (Act)));
3514 end Check_Prefixed_Call;
3516 --------------------
3517 -- Insert_Default --
3518 --------------------
3520 procedure Insert_Default is
3525 -- Missing argument in call, nothing to insert
3527 if No (Default_Value (F)) then
3531 -- Note that we do a full New_Copy_Tree, so that any associated
3532 -- Itypes are properly copied. This may not be needed any more,
3533 -- but it does no harm as a safety measure. Defaults of a generic
3534 -- formal may be out of bounds of the corresponding actual (see
3535 -- cc1311b) and an additional check may be required.
3540 New_Scope => Current_Scope,
3543 if Is_Concurrent_Type (Scope (Nam))
3544 and then Has_Discriminants (Scope (Nam))
3546 Replace_Actual_Discriminants (N, Actval);
3549 if Is_Overloadable (Nam)
3550 and then Present (Alias (Nam))
3552 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3553 and then not Is_Tagged_Type (Etype (F))
3555 -- If default is a real literal, do not introduce a
3556 -- conversion whose effect may depend on the run-time
3557 -- size of universal real.
3559 if Nkind (Actval) = N_Real_Literal then
3560 Set_Etype (Actval, Base_Type (Etype (F)));
3562 Actval := Unchecked_Convert_To (Etype (F), Actval);
3566 if Is_Scalar_Type (Etype (F)) then
3567 Enable_Range_Check (Actval);
3570 Set_Parent (Actval, N);
3572 -- Resolve aggregates with their base type, to avoid scope
3573 -- anomalies: the subtype was first built in the subprogram
3574 -- declaration, and the current call may be nested.
3576 if Nkind (Actval) = N_Aggregate then
3577 Analyze_And_Resolve (Actval, Etype (F));
3579 Analyze_And_Resolve (Actval, Etype (Actval));
3583 Set_Parent (Actval, N);
3585 -- See note above concerning aggregates
3587 if Nkind (Actval) = N_Aggregate
3588 and then Has_Discriminants (Etype (Actval))
3590 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3592 -- Resolve entities with their own type, which may differ from
3593 -- the type of a reference in a generic context (the view
3594 -- swapping mechanism did not anticipate the re-analysis of
3595 -- default values in calls).
3597 elsif Is_Entity_Name (Actval) then
3598 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3601 Analyze_And_Resolve (Actval, Etype (Actval));
3605 -- If default is a tag indeterminate function call, propagate tag
3606 -- to obtain proper dispatching.
3608 if Is_Controlling_Formal (F)
3609 and then Nkind (Default_Value (F)) = N_Function_Call
3611 Set_Is_Controlling_Actual (Actval);
3616 -- If the default expression raises constraint error, then just
3617 -- silently replace it with an N_Raise_Constraint_Error node, since
3618 -- we already gave the warning on the subprogram spec. If node is
3619 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3620 -- the warnings removal machinery.
3622 if Raises_Constraint_Error (Actval)
3623 and then Nkind (Actval) /= N_Raise_Constraint_Error
3626 Make_Raise_Constraint_Error (Loc,
3627 Reason => CE_Range_Check_Failed));
3628 Set_Raises_Constraint_Error (Actval);
3629 Set_Etype (Actval, Etype (F));
3633 Make_Parameter_Association (Loc,
3634 Explicit_Actual_Parameter => Actval,
3635 Selector_Name => Make_Identifier (Loc, Chars (F)));
3637 -- Case of insertion is first named actual
3639 if No (Prev) or else
3640 Nkind (Parent (Prev)) /= N_Parameter_Association
3642 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3643 Set_First_Named_Actual (N, Actval);
3646 if No (Parameter_Associations (N)) then
3647 Set_Parameter_Associations (N, New_List (Assoc));
3649 Append (Assoc, Parameter_Associations (N));
3653 Insert_After (Prev, Assoc);
3656 -- Case of insertion is not first named actual
3659 Set_Next_Named_Actual
3660 (Assoc, Next_Named_Actual (Parent (Prev)));
3661 Set_Next_Named_Actual (Parent (Prev), Actval);
3662 Append (Assoc, Parameter_Associations (N));
3665 Mark_Rewrite_Insertion (Assoc);
3666 Mark_Rewrite_Insertion (Actval);
3671 --------------------
3672 -- Property_Error --
3673 --------------------
3675 procedure Property_Error
3681 Error_Msg_Name_1 := Prop_Nam;
3683 ("external variable & with enabled property % cannot appear as "
3684 & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id);
3685 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3692 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3693 FT1 : Entity_Id := T1;
3694 FT2 : Entity_Id := T2;
3697 if Is_Private_Type (T1)
3698 and then Present (Full_View (T1))
3700 FT1 := Full_View (T1);
3703 if Is_Private_Type (T2)
3704 and then Present (Full_View (T2))
3706 FT2 := Full_View (T2);
3709 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3712 --------------------------
3713 -- Static_Concatenation --
3714 --------------------------
3716 function Static_Concatenation (N : Node_Id) return Boolean is
3719 when N_String_Literal =>
3724 -- Concatenation is static when both operands are static and
3725 -- the concatenation operator is a predefined one.
3727 return Scope (Entity (N)) = Standard_Standard
3729 Static_Concatenation (Left_Opnd (N))
3731 Static_Concatenation (Right_Opnd (N));
3734 if Is_Entity_Name (N) then
3736 Ent : constant Entity_Id := Entity (N);
3738 return Ekind (Ent) = E_Constant
3739 and then Present (Constant_Value (Ent))
3741 Is_OK_Static_Expression (Constant_Value (Ent));
3748 end Static_Concatenation;
3750 -- Start of processing for Resolve_Actuals
3753 Check_Argument_Order;
3754 Check_Function_Writable_Actuals (N);
3756 if Present (First_Actual (N)) then
3757 Check_Prefixed_Call;
3760 A := First_Actual (N);
3761 F := First_Formal (Nam);
3762 while Present (F) loop
3763 if No (A) and then Needs_No_Actuals (Nam) then
3766 -- If we have an error in any actual or formal, indicated by a type
3767 -- of Any_Type, then abandon resolution attempt, and set result type
3768 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3769 -- type is imposed from context.
3771 elsif (Present (A) and then Etype (A) = Any_Type)
3772 or else Etype (F) = Any_Type
3774 if Nkind (A) /= N_Raise_Expression then
3775 Set_Etype (N, Any_Type);
3780 -- Case where actual is present
3782 -- If the actual is an entity, generate a reference to it now. We
3783 -- do this before the actual is resolved, because a formal of some
3784 -- protected subprogram, or a task discriminant, will be rewritten
3785 -- during expansion, and the source entity reference may be lost.
3788 and then Is_Entity_Name (A)
3789 and then Comes_From_Source (N)
3791 Orig_A := Entity (A);
3793 if Present (Orig_A) then
3794 if Is_Formal (Orig_A)
3795 and then Ekind (F) /= E_In_Parameter
3797 Generate_Reference (Orig_A, A, 'm');
3799 elsif not Is_Overloaded (A) then
3800 if Ekind (F) /= E_Out_Parameter then
3801 Generate_Reference (Orig_A, A);
3803 -- RM 6.4.1(12): For an out parameter that is passed by
3804 -- copy, the formal parameter object is created, and:
3806 -- * For an access type, the formal parameter is initialized
3807 -- from the value of the actual, without checking that the
3808 -- value satisfies any constraint, any predicate, or any
3809 -- exclusion of the null value.
3811 -- * For a scalar type that has the Default_Value aspect
3812 -- specified, the formal parameter is initialized from the
3813 -- value of the actual, without checking that the value
3814 -- satisfies any constraint or any predicate.
3815 -- I do not understand why this case is included??? this is
3816 -- not a case where an OUT parameter is treated as IN OUT.
3818 -- * For a composite type with discriminants or that has
3819 -- implicit initial values for any subcomponents, the
3820 -- behavior is as for an in out parameter passed by copy.
3822 -- Hence for these cases we generate the read reference now
3823 -- (the write reference will be generated later by
3824 -- Note_Possible_Modification).
3826 elsif Is_By_Copy_Type (Etype (F))
3828 (Is_Access_Type (Etype (F))
3830 (Is_Scalar_Type (Etype (F))
3832 Present (Default_Aspect_Value (Etype (F))))
3834 (Is_Composite_Type (Etype (F))
3835 and then (Has_Discriminants (Etype (F))
3836 or else Is_Partially_Initialized_Type
3839 Generate_Reference (Orig_A, A);
3846 and then (Nkind (Parent (A)) /= N_Parameter_Association
3847 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3849 -- If style checking mode on, check match of formal name
3852 if Nkind (Parent (A)) = N_Parameter_Association then
3853 Check_Identifier (Selector_Name (Parent (A)), F);
3857 -- If the formal is Out or In_Out, do not resolve and expand the
3858 -- conversion, because it is subsequently expanded into explicit
3859 -- temporaries and assignments. However, the object of the
3860 -- conversion can be resolved. An exception is the case of tagged
3861 -- type conversion with a class-wide actual. In that case we want
3862 -- the tag check to occur and no temporary will be needed (no
3863 -- representation change can occur) and the parameter is passed by
3864 -- reference, so we go ahead and resolve the type conversion.
3865 -- Another exception is the case of reference to component or
3866 -- subcomponent of a bit-packed array, in which case we want to
3867 -- defer expansion to the point the in and out assignments are
3870 if Ekind (F) /= E_In_Parameter
3871 and then Nkind (A) = N_Type_Conversion
3872 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3874 if Ekind (F) = E_In_Out_Parameter
3875 and then Is_Array_Type (Etype (F))
3877 -- In a view conversion, the conversion must be legal in
3878 -- both directions, and thus both component types must be
3879 -- aliased, or neither (4.6 (8)).
3881 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3882 -- the privacy requirement should not apply to generic
3883 -- types, and should be checked in an instance. ARG query
3886 if Has_Aliased_Components (Etype (Expression (A))) /=
3887 Has_Aliased_Components (Etype (F))
3890 ("both component types in a view conversion must be"
3891 & " aliased, or neither", A);
3893 -- Comment here??? what set of cases???
3896 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3898 -- Check view conv between unrelated by ref array types
3900 if Is_By_Reference_Type (Etype (F))
3901 or else Is_By_Reference_Type (Etype (Expression (A)))
3904 ("view conversion between unrelated by reference "
3905 & "array types not allowed (\'A'I-00246)", A);
3907 -- In Ada 2005 mode, check view conversion component
3908 -- type cannot be private, tagged, or volatile. Note
3909 -- that we only apply this to source conversions. The
3910 -- generated code can contain conversions which are
3911 -- not subject to this test, and we cannot extract the
3912 -- component type in such cases since it is not present.
3914 elsif Comes_From_Source (A)
3915 and then Ada_Version >= Ada_2005
3918 Comp_Type : constant Entity_Id :=
3920 (Etype (Expression (A)));
3922 if (Is_Private_Type (Comp_Type)
3923 and then not Is_Generic_Type (Comp_Type))
3924 or else Is_Tagged_Type (Comp_Type)
3925 or else Is_Volatile (Comp_Type)
3928 ("component type of a view conversion cannot"
3929 & " be private, tagged, or volatile"
3938 -- Resolve expression if conversion is all OK
3940 if (Conversion_OK (A)
3941 or else Valid_Conversion (A, Etype (A), Expression (A)))
3942 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3944 Resolve (Expression (A));
3947 -- If the actual is a function call that returns a limited
3948 -- unconstrained object that needs finalization, create a
3949 -- transient scope for it, so that it can receive the proper
3950 -- finalization list.
3952 elsif Nkind (A) = N_Function_Call
3953 and then Is_Limited_Record (Etype (F))
3954 and then not Is_Constrained (Etype (F))
3955 and then Expander_Active
3956 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3958 Establish_Transient_Scope (A, Sec_Stack => False);
3959 Resolve (A, Etype (F));
3961 -- A small optimization: if one of the actuals is a concatenation
3962 -- create a block around a procedure call to recover stack space.
3963 -- This alleviates stack usage when several procedure calls in
3964 -- the same statement list use concatenation. We do not perform
3965 -- this wrapping for code statements, where the argument is a
3966 -- static string, and we want to preserve warnings involving
3967 -- sequences of such statements.
3969 elsif Nkind (A) = N_Op_Concat
3970 and then Nkind (N) = N_Procedure_Call_Statement
3971 and then Expander_Active
3973 not (Is_Intrinsic_Subprogram (Nam)
3974 and then Chars (Nam) = Name_Asm)
3975 and then not Static_Concatenation (A)
3977 Establish_Transient_Scope (A, Sec_Stack => False);
3978 Resolve (A, Etype (F));
3981 if Nkind (A) = N_Type_Conversion
3982 and then Is_Array_Type (Etype (F))
3983 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3985 (Is_Limited_Type (Etype (F))
3986 or else Is_Limited_Type (Etype (Expression (A))))
3989 ("conversion between unrelated limited array types "
3990 & "not allowed ('A'I-00246)", A);
3992 if Is_Limited_Type (Etype (F)) then
3993 Explain_Limited_Type (Etype (F), A);
3996 if Is_Limited_Type (Etype (Expression (A))) then
3997 Explain_Limited_Type (Etype (Expression (A)), A);
4001 -- (Ada 2005: AI-251): If the actual is an allocator whose
4002 -- directly designated type is a class-wide interface, we build
4003 -- an anonymous access type to use it as the type of the
4004 -- allocator. Later, when the subprogram call is expanded, if
4005 -- the interface has a secondary dispatch table the expander
4006 -- will add a type conversion to force the correct displacement
4009 if Nkind (A) = N_Allocator then
4011 DDT : constant Entity_Id :=
4012 Directly_Designated_Type (Base_Type (Etype (F)));
4014 New_Itype : Entity_Id;
4017 if Is_Class_Wide_Type (DDT)
4018 and then Is_Interface (DDT)
4020 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
4021 Set_Etype (New_Itype, Etype (A));
4022 Set_Directly_Designated_Type
4023 (New_Itype, Directly_Designated_Type (Etype (A)));
4024 Set_Etype (A, New_Itype);
4027 -- Ada 2005, AI-162:If the actual is an allocator, the
4028 -- innermost enclosing statement is the master of the
4029 -- created object. This needs to be done with expansion
4030 -- enabled only, otherwise the transient scope will not
4031 -- be removed in the expansion of the wrapped construct.
4033 if (Is_Controlled (DDT) or else Has_Task (DDT))
4034 and then Expander_Active
4036 Establish_Transient_Scope (A, Sec_Stack => False);
4040 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4041 Check_Restriction (No_Access_Parameter_Allocators, A);
4045 -- (Ada 2005): The call may be to a primitive operation of a
4046 -- tagged synchronized type, declared outside of the type. In
4047 -- this case the controlling actual must be converted to its
4048 -- corresponding record type, which is the formal type. The
4049 -- actual may be a subtype, either because of a constraint or
4050 -- because it is a generic actual, so use base type to locate
4053 F_Typ := Base_Type (Etype (F));
4055 if Is_Tagged_Type (F_Typ)
4056 and then (Is_Concurrent_Type (F_Typ)
4057 or else Is_Concurrent_Record_Type (F_Typ))
4059 -- If the actual is overloaded, look for an interpretation
4060 -- that has a synchronized type.
4062 if not Is_Overloaded (A) then
4063 A_Typ := Base_Type (Etype (A));
4067 Index : Interp_Index;
4071 Get_First_Interp (A, Index, It);
4072 while Present (It.Typ) loop
4073 if Is_Concurrent_Type (It.Typ)
4074 or else Is_Concurrent_Record_Type (It.Typ)
4076 A_Typ := Base_Type (It.Typ);
4080 Get_Next_Interp (Index, It);
4086 Full_A_Typ : Entity_Id;
4089 if Present (Full_View (A_Typ)) then
4090 Full_A_Typ := Base_Type (Full_View (A_Typ));
4092 Full_A_Typ := A_Typ;
4095 -- Tagged synchronized type (case 1): the actual is a
4098 if Is_Concurrent_Type (A_Typ)
4099 and then Corresponding_Record_Type (A_Typ) = F_Typ
4102 Unchecked_Convert_To
4103 (Corresponding_Record_Type (A_Typ), A));
4104 Resolve (A, Etype (F));
4106 -- Tagged synchronized type (case 2): the formal is a
4109 elsif Ekind (Full_A_Typ) = E_Record_Type
4111 (Corresponding_Concurrent_Type (Full_A_Typ))
4112 and then Is_Concurrent_Type (F_Typ)
4113 and then Present (Corresponding_Record_Type (F_Typ))
4114 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4116 Resolve (A, Corresponding_Record_Type (F_Typ));
4121 Resolve (A, Etype (F));
4125 -- Not a synchronized operation
4128 Resolve (A, Etype (F));
4135 -- An actual cannot be an untagged formal incomplete type
4137 if Ekind (A_Typ) = E_Incomplete_Type
4138 and then not Is_Tagged_Type (A_Typ)
4139 and then Is_Generic_Type (A_Typ)
4142 ("invalid use of untagged formal incomplete type", A);
4145 if Comes_From_Source (Original_Node (N))
4146 and then Nkind_In (Original_Node (N), N_Function_Call,
4147 N_Procedure_Call_Statement)
4149 -- In formal mode, check that actual parameters matching
4150 -- formals of tagged types are objects (or ancestor type
4151 -- conversions of objects), not general expressions.
4153 if Is_Actual_Tagged_Parameter (A) then
4154 if Is_SPARK_05_Object_Reference (A) then
4157 elsif Nkind (A) = N_Type_Conversion then
4159 Operand : constant Node_Id := Expression (A);
4160 Operand_Typ : constant Entity_Id := Etype (Operand);
4161 Target_Typ : constant Entity_Id := A_Typ;
4164 if not Is_SPARK_05_Object_Reference (Operand) then
4165 Check_SPARK_05_Restriction
4166 ("object required", Operand);
4168 -- In formal mode, the only view conversions are those
4169 -- involving ancestor conversion of an extended type.
4172 (Is_Tagged_Type (Target_Typ)
4173 and then not Is_Class_Wide_Type (Target_Typ)
4174 and then Is_Tagged_Type (Operand_Typ)
4175 and then not Is_Class_Wide_Type (Operand_Typ)
4176 and then Is_Ancestor (Target_Typ, Operand_Typ))
4179 (F, E_Out_Parameter, E_In_Out_Parameter)
4181 Check_SPARK_05_Restriction
4182 ("ancestor conversion is the only permitted "
4183 & "view conversion", A);
4185 Check_SPARK_05_Restriction
4186 ("ancestor conversion required", A);
4195 Check_SPARK_05_Restriction ("object required", A);
4198 -- In formal mode, the only view conversions are those
4199 -- involving ancestor conversion of an extended type.
4201 elsif Nkind (A) = N_Type_Conversion
4202 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4204 Check_SPARK_05_Restriction
4205 ("ancestor conversion is the only permitted view "
4210 -- has warnings suppressed, then we reset Never_Set_In_Source for
4211 -- the calling entity. The reason for this is to catch cases like
4212 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4213 -- uses trickery to modify an IN parameter.
4215 if Ekind (F) = E_In_Parameter
4216 and then Is_Entity_Name (A)
4217 and then Present (Entity (A))
4218 and then Ekind (Entity (A)) = E_Variable
4219 and then Has_Warnings_Off (F_Typ)
4221 Set_Never_Set_In_Source (Entity (A), False);
4224 -- Perform error checks for IN and IN OUT parameters
4226 if Ekind (F) /= E_Out_Parameter then
4228 -- Check unset reference. For scalar parameters, it is clearly
4229 -- wrong to pass an uninitialized value as either an IN or
4230 -- IN-OUT parameter. For composites, it is also clearly an
4231 -- error to pass a completely uninitialized value as an IN
4232 -- parameter, but the case of IN OUT is trickier. We prefer
4233 -- not to give a warning here. For example, suppose there is
4234 -- a routine that sets some component of a record to False.
4235 -- It is perfectly reasonable to make this IN-OUT and allow
4236 -- either initialized or uninitialized records to be passed
4239 -- For partially initialized composite values, we also avoid
4240 -- warnings, since it is quite likely that we are passing a
4241 -- partially initialized value and only the initialized fields
4242 -- will in fact be read in the subprogram.
4244 if Is_Scalar_Type (A_Typ)
4245 or else (Ekind (F) = E_In_Parameter
4246 and then not Is_Partially_Initialized_Type (A_Typ))
4248 Check_Unset_Reference (A);
4251 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4252 -- actual to a nested call, since this is case of reading an
4253 -- out parameter, which is not allowed.
4255 if Ada_Version = Ada_83
4256 and then Is_Entity_Name (A)
4257 and then Ekind (Entity (A)) = E_Out_Parameter
4259 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4263 -- Case of OUT or IN OUT parameter
4265 if Ekind (F) /= E_In_Parameter then
4267 -- For an Out parameter, check for useless assignment. Note
4268 -- that we can't set Last_Assignment this early, because we may
4269 -- kill current values in Resolve_Call, and that call would
4270 -- clobber the Last_Assignment field.
4272 -- Note: call Warn_On_Useless_Assignment before doing the check
4273 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4274 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4275 -- reflects the last assignment, not this one.
4277 if Ekind (F) = E_Out_Parameter then
4278 if Warn_On_Modified_As_Out_Parameter (F)
4279 and then Is_Entity_Name (A)
4280 and then Present (Entity (A))
4281 and then Comes_From_Source (N)
4283 Warn_On_Useless_Assignment (Entity (A), A);
4287 -- Validate the form of the actual. Note that the call to
4288 -- Is_OK_Variable_For_Out_Formal generates the required
4289 -- reference in this case.
4291 -- A call to an initialization procedure for an aggregate
4292 -- component may initialize a nested component of a constant
4293 -- designated object. In this context the object is variable.
4295 if not Is_OK_Variable_For_Out_Formal (A)
4296 and then not Is_Init_Proc (Nam)
4298 Error_Msg_NE ("actual for& must be a variable", A, F);
4300 if Is_Subprogram (Current_Scope)
4302 (Is_Invariant_Procedure (Current_Scope)
4303 or else Is_Predicate_Function (Current_Scope))
4306 ("function used in predicate cannot "
4307 & "modify its argument", F);
4311 -- What's the following about???
4313 if Is_Entity_Name (A) then
4314 Kill_Checks (Entity (A));
4320 if Etype (A) = Any_Type then
4321 Set_Etype (N, Any_Type);
4325 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4327 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4329 -- Apply predicate tests except in certain special cases. Note
4330 -- that it might be more consistent to apply these only when
4331 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4332 -- for the outbound predicate tests ???
4334 if Predicate_Tests_On_Arguments (Nam) then
4335 Apply_Predicate_Check (A, F_Typ);
4338 -- Apply required constraint checks
4340 -- Gigi looks at the check flag and uses the appropriate types.
4341 -- For now since one flag is used there is an optimization
4342 -- which might not be done in the IN OUT case since Gigi does
4343 -- not do any analysis. More thought required about this ???
4345 -- In fact is this comment obsolete??? doesn't the expander now
4346 -- generate all these tests anyway???
4348 if Is_Scalar_Type (Etype (A)) then
4349 Apply_Scalar_Range_Check (A, F_Typ);
4351 elsif Is_Array_Type (Etype (A)) then
4352 Apply_Length_Check (A, F_Typ);
4354 elsif Is_Record_Type (F_Typ)
4355 and then Has_Discriminants (F_Typ)
4356 and then Is_Constrained (F_Typ)
4357 and then (not Is_Derived_Type (F_Typ)
4358 or else Comes_From_Source (Nam))
4360 Apply_Discriminant_Check (A, F_Typ);
4362 -- For view conversions of a discriminated object, apply
4363 -- check to object itself, the conversion alreay has the
4366 if Nkind (A) = N_Type_Conversion
4367 and then Is_Constrained (Etype (Expression (A)))
4369 Apply_Discriminant_Check (Expression (A), F_Typ);
4372 elsif Is_Access_Type (F_Typ)
4373 and then Is_Array_Type (Designated_Type (F_Typ))
4374 and then Is_Constrained (Designated_Type (F_Typ))
4376 Apply_Length_Check (A, F_Typ);
4378 elsif Is_Access_Type (F_Typ)
4379 and then Has_Discriminants (Designated_Type (F_Typ))
4380 and then Is_Constrained (Designated_Type (F_Typ))
4382 Apply_Discriminant_Check (A, F_Typ);
4385 Apply_Range_Check (A, F_Typ);
4388 -- Ada 2005 (AI-231): Note that the controlling parameter case
4389 -- already existed in Ada 95, which is partially checked
4390 -- elsewhere (see Checks), and we don't want the warning
4391 -- message to differ.
4393 if Is_Access_Type (F_Typ)
4394 and then Can_Never_Be_Null (F_Typ)
4395 and then Known_Null (A)
4397 if Is_Controlling_Formal (F) then
4398 Apply_Compile_Time_Constraint_Error
4400 Msg => "null value not allowed here??",
4401 Reason => CE_Access_Check_Failed);
4403 elsif Ada_Version >= Ada_2005 then
4404 Apply_Compile_Time_Constraint_Error
4406 Msg => "(Ada 2005) null not allowed in "
4407 & "null-excluding formal??",
4408 Reason => CE_Null_Not_Allowed);
4413 -- Checks for OUT parameters and IN OUT parameters
4415 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4417 -- If there is a type conversion, to make sure the return value
4418 -- meets the constraints of the variable before the conversion.
4420 if Nkind (A) = N_Type_Conversion then
4421 if Is_Scalar_Type (A_Typ) then
4422 Apply_Scalar_Range_Check
4423 (Expression (A), Etype (Expression (A)), A_Typ);
4426 (Expression (A), Etype (Expression (A)), A_Typ);
4429 -- If no conversion apply scalar range checks and length checks
4430 -- base on the subtype of the actual (NOT that of the formal).
4433 if Is_Scalar_Type (F_Typ) then
4434 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4435 elsif Is_Array_Type (F_Typ)
4436 and then Ekind (F) = E_Out_Parameter
4438 Apply_Length_Check (A, F_Typ);
4440 Apply_Range_Check (A, A_Typ, F_Typ);
4444 -- Note: we do not apply the predicate checks for the case of
4445 -- OUT and IN OUT parameters. They are instead applied in the
4446 -- Expand_Actuals routine in Exp_Ch6.
4449 -- An actual associated with an access parameter is implicitly
4450 -- converted to the anonymous access type of the formal and must
4451 -- satisfy the legality checks for access conversions.
4453 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4454 if not Valid_Conversion (A, F_Typ, A) then
4456 ("invalid implicit conversion for access parameter", A);
4459 -- If the actual is an access selected component of a variable,
4460 -- the call may modify its designated object. It is reasonable
4461 -- to treat this as a potential modification of the enclosing
4462 -- record, to prevent spurious warnings that it should be
4463 -- declared as a constant, because intuitively programmers
4464 -- regard the designated subcomponent as part of the record.
4466 if Nkind (A) = N_Selected_Component
4467 and then Is_Entity_Name (Prefix (A))
4468 and then not Is_Constant_Object (Entity (Prefix (A)))
4470 Note_Possible_Modification (A, Sure => False);
4474 -- Check bad case of atomic/volatile argument (RM C.6(12))
4476 if Is_By_Reference_Type (Etype (F))
4477 and then Comes_From_Source (N)
4479 if Is_Atomic_Object (A)
4480 and then not Is_Atomic (Etype (F))
4483 ("cannot pass atomic argument to non-atomic formal&",
4486 elsif Is_Volatile_Object (A)
4487 and then not Is_Volatile (Etype (F))
4490 ("cannot pass volatile argument to non-volatile formal&",
4495 -- Check that subprograms don't have improper controlling
4496 -- arguments (RM 3.9.2 (9)).
4498 -- A primitive operation may have an access parameter of an
4499 -- incomplete tagged type, but a dispatching call is illegal
4500 -- if the type is still incomplete.
4502 if Is_Controlling_Formal (F) then
4503 Set_Is_Controlling_Actual (A);
4505 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4507 Desig : constant Entity_Id := Designated_Type (Etype (F));
4509 if Ekind (Desig) = E_Incomplete_Type
4510 and then No (Full_View (Desig))
4511 and then No (Non_Limited_View (Desig))
4514 ("premature use of incomplete type& "
4515 & "in dispatching call", A, Desig);
4520 elsif Nkind (A) = N_Explicit_Dereference then
4521 Validate_Remote_Access_To_Class_Wide_Type (A);
4524 -- Apply legality rule 3.9.2 (9/1)
4526 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4527 and then not Is_Class_Wide_Type (F_Typ)
4528 and then not Is_Controlling_Formal (F)
4529 and then not In_Instance
4531 Error_Msg_N ("class-wide argument not allowed here!", A);
4533 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4534 Error_Msg_Node_2 := F_Typ;
4536 ("& is not a dispatching operation of &!", A, Nam);
4539 -- Apply the checks described in 3.10.2(27): if the context is a
4540 -- specific access-to-object, the actual cannot be class-wide.
4541 -- Use base type to exclude access_to_subprogram cases.
4543 elsif Is_Access_Type (A_Typ)
4544 and then Is_Access_Type (F_Typ)
4545 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4546 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4547 or else (Nkind (A) = N_Attribute_Reference
4549 Is_Class_Wide_Type (Etype (Prefix (A)))))
4550 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4551 and then not Is_Controlling_Formal (F)
4553 -- Disable these checks for call to imported C++ subprograms
4556 (Is_Entity_Name (Name (N))
4557 and then Is_Imported (Entity (Name (N)))
4558 and then Convention (Entity (Name (N))) = Convention_CPP)
4561 ("access to class-wide argument not allowed here!", A);
4563 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4564 Error_Msg_Node_2 := Designated_Type (F_Typ);
4566 ("& is not a dispatching operation of &!", A, Nam);
4570 Check_Aliased_Parameter;
4574 -- If it is a named association, treat the selector_name as a
4575 -- proper identifier, and mark the corresponding entity.
4577 if Nkind (Parent (A)) = N_Parameter_Association
4579 -- Ignore reference in SPARK mode, as it refers to an entity not
4580 -- in scope at the point of reference, so the reference should
4581 -- be ignored for computing effects of subprograms.
4583 and then not GNATprove_Mode
4585 Set_Entity (Selector_Name (Parent (A)), F);
4586 Generate_Reference (F, Selector_Name (Parent (A)));
4587 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4588 Generate_Reference (F_Typ, N, ' ');
4593 if Ekind (F) /= E_Out_Parameter then
4594 Check_Unset_Reference (A);
4597 -- The following checks are only relevant when SPARK_Mode is on as
4598 -- they are not standard Ada legality rule. Internally generated
4599 -- temporaries are ignored.
4602 and then Is_Effectively_Volatile_Object (A)
4603 and then Comes_From_Source (A)
4605 -- An effectively volatile object may act as an actual
4606 -- parameter when the corresponding formal is of a non-scalar
4609 if Is_Volatile (Etype (F))
4610 and then not Is_Scalar_Type (Etype (F))
4614 -- An effectively volatile object may act as an actual
4615 -- parameter in a call to an instance of Unchecked_Conversion.
4617 elsif Is_Unchecked_Conversion_Instance (Nam) then
4622 ("volatile object cannot act as actual in a call (SPARK "
4623 & "RM 7.1.3(12))", A);
4626 -- Detect an external variable with an enabled property that
4627 -- does not match the mode of the corresponding formal in a
4628 -- procedure call. Functions are not considered because they
4629 -- cannot have effectively volatile formal parameters in the
4632 if Ekind (Nam) = E_Procedure
4633 and then Is_Entity_Name (A)
4634 and then Present (Entity (A))
4635 and then Ekind (Entity (A)) = E_Variable
4639 if Ekind (F) = E_In_Parameter then
4640 if Async_Readers_Enabled (A_Id) then
4641 Property_Error (A, A_Id, Name_Async_Readers);
4642 elsif Effective_Reads_Enabled (A_Id) then
4643 Property_Error (A, A_Id, Name_Effective_Reads);
4644 elsif Effective_Writes_Enabled (A_Id) then
4645 Property_Error (A, A_Id, Name_Effective_Writes);
4648 elsif Ekind (F) = E_Out_Parameter
4649 and then Async_Writers_Enabled (A_Id)
4651 Error_Msg_Name_1 := Name_Async_Writers;
4653 ("external variable & with enabled property % cannot "
4654 & "appear as actual in procedure call "
4655 & "(SPARK RM 7.1.3(11))", A, A_Id);
4657 ("\\corresponding formal parameter has mode Out", A);
4662 -- A formal parameter of a specific tagged type whose related
4663 -- subprogram is subject to pragma Extensions_Visible with value
4664 -- "False" cannot act as an actual in a subprogram with value
4665 -- "True" (SPARK RM 6.1.7(3)).
4667 if Is_EVF_Expression (A)
4668 and then Extensions_Visible_Status (Nam) =
4669 Extensions_Visible_True
4672 ("formal parameter with Extensions_Visible False cannot act "
4673 & "as actual parameter", A);
4675 ("\subprogram & has Extensions_Visible True", A, Nam);
4678 -- The actual parameter of a Ghost subprogram whose formal is of
4679 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(13)).
4681 if Is_Ghost_Entity (Nam)
4682 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4683 and then Is_Entity_Name (A)
4684 and then Present (Entity (A))
4685 and then not Is_Ghost_Entity (Entity (A))
4688 ("non-ghost variable & cannot appear as actual in call to "
4689 & "ghost procedure", A, Entity (A));
4691 if Ekind (F) = E_In_Out_Parameter then
4692 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4694 Error_Msg_N ("\corresponding formal has mode OUT", A);
4700 -- Case where actual is not present
4708 end Resolve_Actuals;
4710 -----------------------
4711 -- Resolve_Allocator --
4712 -----------------------
4714 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4715 Desig_T : constant Entity_Id := Designated_Type (Typ);
4716 E : constant Node_Id := Expression (N);
4718 Discrim : Entity_Id;
4721 Assoc : Node_Id := Empty;
4724 procedure Check_Allocator_Discrim_Accessibility
4725 (Disc_Exp : Node_Id;
4726 Alloc_Typ : Entity_Id);
4727 -- Check that accessibility level associated with an access discriminant
4728 -- initialized in an allocator by the expression Disc_Exp is not deeper
4729 -- than the level of the allocator type Alloc_Typ. An error message is
4730 -- issued if this condition is violated. Specialized checks are done for
4731 -- the cases of a constraint expression which is an access attribute or
4732 -- an access discriminant.
4734 function In_Dispatching_Context return Boolean;
4735 -- If the allocator is an actual in a call, it is allowed to be class-
4736 -- wide when the context is not because it is a controlling actual.
4738 -------------------------------------------
4739 -- Check_Allocator_Discrim_Accessibility --
4740 -------------------------------------------
4742 procedure Check_Allocator_Discrim_Accessibility
4743 (Disc_Exp : Node_Id;
4744 Alloc_Typ : Entity_Id)
4747 if Type_Access_Level (Etype (Disc_Exp)) >
4748 Deepest_Type_Access_Level (Alloc_Typ)
4751 ("operand type has deeper level than allocator type", Disc_Exp);
4753 -- When the expression is an Access attribute the level of the prefix
4754 -- object must not be deeper than that of the allocator's type.
4756 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4757 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4759 and then Object_Access_Level (Prefix (Disc_Exp)) >
4760 Deepest_Type_Access_Level (Alloc_Typ)
4763 ("prefix of attribute has deeper level than allocator type",
4766 -- When the expression is an access discriminant the check is against
4767 -- the level of the prefix object.
4769 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4770 and then Nkind (Disc_Exp) = N_Selected_Component
4771 and then Object_Access_Level (Prefix (Disc_Exp)) >
4772 Deepest_Type_Access_Level (Alloc_Typ)
4775 ("access discriminant has deeper level than allocator type",
4778 -- All other cases are legal
4783 end Check_Allocator_Discrim_Accessibility;
4785 ----------------------------
4786 -- In_Dispatching_Context --
4787 ----------------------------
4789 function In_Dispatching_Context return Boolean is
4790 Par : constant Node_Id := Parent (N);
4793 return Nkind (Par) in N_Subprogram_Call
4794 and then Is_Entity_Name (Name (Par))
4795 and then Is_Dispatching_Operation (Entity (Name (Par)));
4796 end In_Dispatching_Context;
4798 -- Start of processing for Resolve_Allocator
4801 -- Replace general access with specific type
4803 if Ekind (Etype (N)) = E_Allocator_Type then
4804 Set_Etype (N, Base_Type (Typ));
4807 if Is_Abstract_Type (Typ) then
4808 Error_Msg_N ("type of allocator cannot be abstract", N);
4811 -- For qualified expression, resolve the expression using the given
4812 -- subtype (nothing to do for type mark, subtype indication)
4814 if Nkind (E) = N_Qualified_Expression then
4815 if Is_Class_Wide_Type (Etype (E))
4816 and then not Is_Class_Wide_Type (Desig_T)
4817 and then not In_Dispatching_Context
4820 ("class-wide allocator not allowed for this access type", N);
4823 Resolve (Expression (E), Etype (E));
4824 Check_Non_Static_Context (Expression (E));
4825 Check_Unset_Reference (Expression (E));
4827 -- A qualified expression requires an exact match of the type.
4828 -- Class-wide matching is not allowed.
4830 if (Is_Class_Wide_Type (Etype (Expression (E)))
4831 or else Is_Class_Wide_Type (Etype (E)))
4832 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4834 Wrong_Type (Expression (E), Etype (E));
4837 -- Calls to build-in-place functions are not currently supported in
4838 -- allocators for access types associated with a simple storage pool.
4839 -- Supporting such allocators may require passing additional implicit
4840 -- parameters to build-in-place functions (or a significant revision
4841 -- of the current b-i-p implementation to unify the handling for
4842 -- multiple kinds of storage pools). ???
4844 if Is_Limited_View (Desig_T)
4845 and then Nkind (Expression (E)) = N_Function_Call
4848 Pool : constant Entity_Id :=
4849 Associated_Storage_Pool (Root_Type (Typ));
4853 Present (Get_Rep_Pragma
4854 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4857 ("limited function calls not yet supported in simple "
4858 & "storage pool allocators", Expression (E));
4863 -- A special accessibility check is needed for allocators that
4864 -- constrain access discriminants. The level of the type of the
4865 -- expression used to constrain an access discriminant cannot be
4866 -- deeper than the type of the allocator (in contrast to access
4867 -- parameters, where the level of the actual can be arbitrary).
4869 -- We can't use Valid_Conversion to perform this check because in
4870 -- general the type of the allocator is unrelated to the type of
4871 -- the access discriminant.
4873 if Ekind (Typ) /= E_Anonymous_Access_Type
4874 or else Is_Local_Anonymous_Access (Typ)
4876 Subtyp := Entity (Subtype_Mark (E));
4878 Aggr := Original_Node (Expression (E));
4880 if Has_Discriminants (Subtyp)
4881 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4883 Discrim := First_Discriminant (Base_Type (Subtyp));
4885 -- Get the first component expression of the aggregate
4887 if Present (Expressions (Aggr)) then
4888 Disc_Exp := First (Expressions (Aggr));
4890 elsif Present (Component_Associations (Aggr)) then
4891 Assoc := First (Component_Associations (Aggr));
4893 if Present (Assoc) then
4894 Disc_Exp := Expression (Assoc);
4903 while Present (Discrim) and then Present (Disc_Exp) loop
4904 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4905 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4908 Next_Discriminant (Discrim);
4910 if Present (Discrim) then
4911 if Present (Assoc) then
4913 Disc_Exp := Expression (Assoc);
4915 elsif Present (Next (Disc_Exp)) then
4919 Assoc := First (Component_Associations (Aggr));
4921 if Present (Assoc) then
4922 Disc_Exp := Expression (Assoc);
4932 -- For a subtype mark or subtype indication, freeze the subtype
4935 Freeze_Expression (E);
4937 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4939 ("initialization required for access-to-constant allocator", N);
4942 -- A special accessibility check is needed for allocators that
4943 -- constrain access discriminants. The level of the type of the
4944 -- expression used to constrain an access discriminant cannot be
4945 -- deeper than the type of the allocator (in contrast to access
4946 -- parameters, where the level of the actual can be arbitrary).
4947 -- We can't use Valid_Conversion to perform this check because
4948 -- in general the type of the allocator is unrelated to the type
4949 -- of the access discriminant.
4951 if Nkind (Original_Node (E)) = N_Subtype_Indication
4952 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4953 or else Is_Local_Anonymous_Access (Typ))
4955 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4957 if Has_Discriminants (Subtyp) then
4958 Discrim := First_Discriminant (Base_Type (Subtyp));
4959 Constr := First (Constraints (Constraint (Original_Node (E))));
4960 while Present (Discrim) and then Present (Constr) loop
4961 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4962 if Nkind (Constr) = N_Discriminant_Association then
4963 Disc_Exp := Original_Node (Expression (Constr));
4965 Disc_Exp := Original_Node (Constr);
4968 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4971 Next_Discriminant (Discrim);
4978 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4979 -- check that the level of the type of the created object is not deeper
4980 -- than the level of the allocator's access type, since extensions can
4981 -- now occur at deeper levels than their ancestor types. This is a
4982 -- static accessibility level check; a run-time check is also needed in
4983 -- the case of an initialized allocator with a class-wide argument (see
4984 -- Expand_Allocator_Expression).
4986 if Ada_Version >= Ada_2005
4987 and then Is_Class_Wide_Type (Desig_T)
4990 Exp_Typ : Entity_Id;
4993 if Nkind (E) = N_Qualified_Expression then
4994 Exp_Typ := Etype (E);
4995 elsif Nkind (E) = N_Subtype_Indication then
4996 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4998 Exp_Typ := Entity (E);
5001 if Type_Access_Level (Exp_Typ) >
5002 Deepest_Type_Access_Level (Typ)
5004 if In_Instance_Body then
5005 Error_Msg_Warn := SPARK_Mode /= On;
5007 ("type in allocator has deeper level than "
5008 & "designated class-wide type<<", E);
5009 Error_Msg_N ("\Program_Error [<<", E);
5011 Make_Raise_Program_Error (Sloc (N),
5012 Reason => PE_Accessibility_Check_Failed));
5015 -- Do not apply Ada 2005 accessibility checks on a class-wide
5016 -- allocator if the type given in the allocator is a formal
5017 -- type. A run-time check will be performed in the instance.
5019 elsif not Is_Generic_Type (Exp_Typ) then
5020 Error_Msg_N ("type in allocator has deeper level than "
5021 & "designated class-wide type", E);
5027 -- Check for allocation from an empty storage pool
5029 if No_Pool_Assigned (Typ) then
5030 Error_Msg_N ("allocation from empty storage pool!", N);
5032 -- If the context is an unchecked conversion, as may happen within an
5033 -- inlined subprogram, the allocator is being resolved with its own
5034 -- anonymous type. In that case, if the target type has a specific
5035 -- storage pool, it must be inherited explicitly by the allocator type.
5037 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
5038 and then No (Associated_Storage_Pool (Typ))
5040 Set_Associated_Storage_Pool
5041 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
5044 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
5045 Check_Restriction (No_Anonymous_Allocators, N);
5048 -- Check that an allocator with task parts isn't for a nested access
5049 -- type when restriction No_Task_Hierarchy applies.
5051 if not Is_Library_Level_Entity (Base_Type (Typ))
5052 and then Has_Task (Base_Type (Desig_T))
5054 Check_Restriction (No_Task_Hierarchy, N);
5057 -- An illegal allocator may be rewritten as a raise Program_Error
5060 if Nkind (N) = N_Allocator then
5062 -- An anonymous access discriminant is the definition of a
5065 if Ekind (Typ) = E_Anonymous_Access_Type
5066 and then Nkind (Associated_Node_For_Itype (Typ)) =
5067 N_Discriminant_Specification
5070 Discr : constant Entity_Id :=
5071 Defining_Identifier (Associated_Node_For_Itype (Typ));
5074 Check_Restriction (No_Coextensions, N);
5076 -- Ada 2012 AI05-0052: If the designated type of the allocator
5077 -- is limited, then the allocator shall not be used to define
5078 -- the value of an access discriminant unless the discriminated
5079 -- type is immutably limited.
5081 if Ada_Version >= Ada_2012
5082 and then Is_Limited_Type (Desig_T)
5083 and then not Is_Limited_View (Scope (Discr))
5086 ("only immutably limited types can have anonymous "
5087 & "access discriminants designating a limited type", N);
5091 -- Avoid marking an allocator as a dynamic coextension if it is
5092 -- within a static construct.
5094 if not Is_Static_Coextension (N) then
5095 Set_Is_Dynamic_Coextension (N);
5098 -- Cleanup for potential static coextensions
5101 Set_Is_Dynamic_Coextension (N, False);
5102 Set_Is_Static_Coextension (N, False);
5106 -- Report a simple error: if the designated object is a local task,
5107 -- its body has not been seen yet, and its activation will fail an
5108 -- elaboration check.
5110 if Is_Task_Type (Desig_T)
5111 and then Scope (Base_Type (Desig_T)) = Current_Scope
5112 and then Is_Compilation_Unit (Current_Scope)
5113 and then Ekind (Current_Scope) = E_Package
5114 and then not In_Package_Body (Current_Scope)
5116 Error_Msg_Warn := SPARK_Mode /= On;
5117 Error_Msg_N ("cannot activate task before body seen<<", N);
5118 Error_Msg_N ("\Program_Error [<<", N);
5121 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5122 -- type with a task component on a subpool. This action must raise
5123 -- Program_Error at runtime.
5125 if Ada_Version >= Ada_2012
5126 and then Nkind (N) = N_Allocator
5127 and then Present (Subpool_Handle_Name (N))
5128 and then Has_Task (Desig_T)
5130 Error_Msg_Warn := SPARK_Mode /= On;
5131 Error_Msg_N ("cannot allocate task on subpool<<", N);
5132 Error_Msg_N ("\Program_Error [<<", N);
5135 Make_Raise_Program_Error (Sloc (N),
5136 Reason => PE_Explicit_Raise));
5139 end Resolve_Allocator;
5141 ---------------------------
5142 -- Resolve_Arithmetic_Op --
5143 ---------------------------
5145 -- Used for resolving all arithmetic operators except exponentiation
5147 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5148 L : constant Node_Id := Left_Opnd (N);
5149 R : constant Node_Id := Right_Opnd (N);
5150 TL : constant Entity_Id := Base_Type (Etype (L));
5151 TR : constant Entity_Id := Base_Type (Etype (R));
5155 B_Typ : constant Entity_Id := Base_Type (Typ);
5156 -- We do the resolution using the base type, because intermediate values
5157 -- in expressions always are of the base type, not a subtype of it.
5159 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5160 -- Returns True if N is in a context that expects "any real type"
5162 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5163 -- Return True iff given type is Integer or universal real/integer
5165 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5166 -- Choose type of integer literal in fixed-point operation to conform
5167 -- to available fixed-point type. T is the type of the other operand,
5168 -- which is needed to determine the expected type of N.
5170 procedure Set_Operand_Type (N : Node_Id);
5171 -- Set operand type to T if universal
5173 -------------------------------
5174 -- Expected_Type_Is_Any_Real --
5175 -------------------------------
5177 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5179 -- N is the expression after "delta" in a fixed_point_definition;
5182 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5183 N_Decimal_Fixed_Point_Definition,
5185 -- N is one of the bounds in a real_range_specification;
5188 N_Real_Range_Specification,
5190 -- N is the expression of a delta_constraint;
5193 N_Delta_Constraint);
5194 end Expected_Type_Is_Any_Real;
5196 -----------------------------
5197 -- Is_Integer_Or_Universal --
5198 -----------------------------
5200 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5202 Index : Interp_Index;
5206 if not Is_Overloaded (N) then
5208 return Base_Type (T) = Base_Type (Standard_Integer)
5209 or else T = Universal_Integer
5210 or else T = Universal_Real;
5212 Get_First_Interp (N, Index, It);
5213 while Present (It.Typ) loop
5214 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5215 or else It.Typ = Universal_Integer
5216 or else It.Typ = Universal_Real
5221 Get_Next_Interp (Index, It);
5226 end Is_Integer_Or_Universal;
5228 ----------------------------
5229 -- Set_Mixed_Mode_Operand --
5230 ----------------------------
5232 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5233 Index : Interp_Index;
5237 if Universal_Interpretation (N) = Universal_Integer then
5239 -- A universal integer literal is resolved as standard integer
5240 -- except in the case of a fixed-point result, where we leave it
5241 -- as universal (to be handled by Exp_Fixd later on)
5243 if Is_Fixed_Point_Type (T) then
5244 Resolve (N, Universal_Integer);
5246 Resolve (N, Standard_Integer);
5249 elsif Universal_Interpretation (N) = Universal_Real
5250 and then (T = Base_Type (Standard_Integer)
5251 or else T = Universal_Integer
5252 or else T = Universal_Real)
5254 -- A universal real can appear in a fixed-type context. We resolve
5255 -- the literal with that context, even though this might raise an
5256 -- exception prematurely (the other operand may be zero).
5260 elsif Etype (N) = Base_Type (Standard_Integer)
5261 and then T = Universal_Real
5262 and then Is_Overloaded (N)
5264 -- Integer arg in mixed-mode operation. Resolve with universal
5265 -- type, in case preference rule must be applied.
5267 Resolve (N, Universal_Integer);
5270 and then B_Typ /= Universal_Fixed
5272 -- Not a mixed-mode operation, resolve with context
5276 elsif Etype (N) = Any_Fixed then
5278 -- N may itself be a mixed-mode operation, so use context type
5282 elsif Is_Fixed_Point_Type (T)
5283 and then B_Typ = Universal_Fixed
5284 and then Is_Overloaded (N)
5286 -- Must be (fixed * fixed) operation, operand must have one
5287 -- compatible interpretation.
5289 Resolve (N, Any_Fixed);
5291 elsif Is_Fixed_Point_Type (B_Typ)
5292 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5293 and then Is_Overloaded (N)
5295 -- C * F(X) in a fixed context, where C is a real literal or a
5296 -- fixed-point expression. F must have either a fixed type
5297 -- interpretation or an integer interpretation, but not both.
5299 Get_First_Interp (N, Index, It);
5300 while Present (It.Typ) loop
5301 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5302 if Analyzed (N) then
5303 Error_Msg_N ("ambiguous operand in fixed operation", N);
5305 Resolve (N, Standard_Integer);
5308 elsif Is_Fixed_Point_Type (It.Typ) then
5309 if Analyzed (N) then
5310 Error_Msg_N ("ambiguous operand in fixed operation", N);
5312 Resolve (N, It.Typ);
5316 Get_Next_Interp (Index, It);
5319 -- Reanalyze the literal with the fixed type of the context. If
5320 -- context is Universal_Fixed, we are within a conversion, leave
5321 -- the literal as a universal real because there is no usable
5322 -- fixed type, and the target of the conversion plays no role in
5336 if B_Typ = Universal_Fixed
5337 and then Nkind (Op2) = N_Real_Literal
5339 T2 := Universal_Real;
5344 Set_Analyzed (Op2, False);
5351 end Set_Mixed_Mode_Operand;
5353 ----------------------
5354 -- Set_Operand_Type --
5355 ----------------------
5357 procedure Set_Operand_Type (N : Node_Id) is
5359 if Etype (N) = Universal_Integer
5360 or else Etype (N) = Universal_Real
5364 end Set_Operand_Type;
5366 -- Start of processing for Resolve_Arithmetic_Op
5369 if Comes_From_Source (N)
5370 and then Ekind (Entity (N)) = E_Function
5371 and then Is_Imported (Entity (N))
5372 and then Is_Intrinsic_Subprogram (Entity (N))
5374 Resolve_Intrinsic_Operator (N, Typ);
5377 -- Special-case for mixed-mode universal expressions or fixed point type
5378 -- operation: each argument is resolved separately. The same treatment
5379 -- is required if one of the operands of a fixed point operation is
5380 -- universal real, since in this case we don't do a conversion to a
5381 -- specific fixed-point type (instead the expander handles the case).
5383 -- Set the type of the node to its universal interpretation because
5384 -- legality checks on an exponentiation operand need the context.
5386 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5387 and then Present (Universal_Interpretation (L))
5388 and then Present (Universal_Interpretation (R))
5390 Set_Etype (N, B_Typ);
5391 Resolve (L, Universal_Interpretation (L));
5392 Resolve (R, Universal_Interpretation (R));
5394 elsif (B_Typ = Universal_Real
5395 or else Etype (N) = Universal_Fixed
5396 or else (Etype (N) = Any_Fixed
5397 and then Is_Fixed_Point_Type (B_Typ))
5398 or else (Is_Fixed_Point_Type (B_Typ)
5399 and then (Is_Integer_Or_Universal (L)
5401 Is_Integer_Or_Universal (R))))
5402 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5404 if TL = Universal_Integer or else TR = Universal_Integer then
5405 Check_For_Visible_Operator (N, B_Typ);
5408 -- If context is a fixed type and one operand is integer, the other
5409 -- is resolved with the type of the context.
5411 if Is_Fixed_Point_Type (B_Typ)
5412 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5413 or else TL = Universal_Integer)
5418 elsif Is_Fixed_Point_Type (B_Typ)
5419 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5420 or else TR = Universal_Integer)
5426 Set_Mixed_Mode_Operand (L, TR);
5427 Set_Mixed_Mode_Operand (R, TL);
5430 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5431 -- multiplying operators from being used when the expected type is
5432 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5433 -- some cases where the expected type is actually Any_Real;
5434 -- Expected_Type_Is_Any_Real takes care of that case.
5436 if Etype (N) = Universal_Fixed
5437 or else Etype (N) = Any_Fixed
5439 if B_Typ = Universal_Fixed
5440 and then not Expected_Type_Is_Any_Real (N)
5441 and then not Nkind_In (Parent (N), N_Type_Conversion,
5442 N_Unchecked_Type_Conversion)
5444 Error_Msg_N ("type cannot be determined from context!", N);
5445 Error_Msg_N ("\explicit conversion to result type required", N);
5447 Set_Etype (L, Any_Type);
5448 Set_Etype (R, Any_Type);
5451 if Ada_Version = Ada_83
5452 and then Etype (N) = Universal_Fixed
5454 Nkind_In (Parent (N), N_Type_Conversion,
5455 N_Unchecked_Type_Conversion)
5458 ("(Ada 83) fixed-point operation "
5459 & "needs explicit conversion", N);
5462 -- The expected type is "any real type" in contexts like
5464 -- type T is delta <universal_fixed-expression> ...
5466 -- in which case we need to set the type to Universal_Real
5467 -- so that static expression evaluation will work properly.
5469 if Expected_Type_Is_Any_Real (N) then
5470 Set_Etype (N, Universal_Real);
5472 Set_Etype (N, B_Typ);
5476 elsif Is_Fixed_Point_Type (B_Typ)
5477 and then (Is_Integer_Or_Universal (L)
5478 or else Nkind (L) = N_Real_Literal
5479 or else Nkind (R) = N_Real_Literal
5480 or else Is_Integer_Or_Universal (R))
5482 Set_Etype (N, B_Typ);
5484 elsif Etype (N) = Any_Fixed then
5486 -- If no previous errors, this is only possible if one operand is
5487 -- overloaded and the context is universal. Resolve as such.
5489 Set_Etype (N, B_Typ);
5493 if (TL = Universal_Integer or else TL = Universal_Real)
5495 (TR = Universal_Integer or else TR = Universal_Real)
5497 Check_For_Visible_Operator (N, B_Typ);
5500 -- If the context is Universal_Fixed and the operands are also
5501 -- universal fixed, this is an error, unless there is only one
5502 -- applicable fixed_point type (usually Duration).
5504 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5505 T := Unique_Fixed_Point_Type (N);
5507 if T = Any_Type then
5520 -- If one of the arguments was resolved to a non-universal type.
5521 -- label the result of the operation itself with the same type.
5522 -- Do the same for the universal argument, if any.
5524 T := Intersect_Types (L, R);
5525 Set_Etype (N, Base_Type (T));
5526 Set_Operand_Type (L);
5527 Set_Operand_Type (R);
5530 Generate_Operator_Reference (N, Typ);
5531 Analyze_Dimension (N);
5532 Eval_Arithmetic_Op (N);
5534 -- In SPARK, a multiplication or division with operands of fixed point
5535 -- types must be qualified or explicitly converted to identify the
5538 if (Is_Fixed_Point_Type (Etype (L))
5539 or else Is_Fixed_Point_Type (Etype (R)))
5540 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5542 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5544 Check_SPARK_05_Restriction
5545 ("operation should be qualified or explicitly converted", N);
5548 -- Set overflow and division checking bit
5550 if Nkind (N) in N_Op then
5551 if not Overflow_Checks_Suppressed (Etype (N)) then
5552 Enable_Overflow_Check (N);
5555 -- Give warning if explicit division by zero
5557 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5558 and then not Division_Checks_Suppressed (Etype (N))
5560 Rop := Right_Opnd (N);
5562 if Compile_Time_Known_Value (Rop)
5563 and then ((Is_Integer_Type (Etype (Rop))
5564 and then Expr_Value (Rop) = Uint_0)
5566 (Is_Real_Type (Etype (Rop))
5567 and then Expr_Value_R (Rop) = Ureal_0))
5569 -- Specialize the warning message according to the operation.
5570 -- The following warnings are for the case
5575 -- For division, we have two cases, for float division
5576 -- of an unconstrained float type, on a machine where
5577 -- Machine_Overflows is false, we don't get an exception
5578 -- at run-time, but rather an infinity or Nan. The Nan
5579 -- case is pretty obscure, so just warn about infinities.
5581 if Is_Floating_Point_Type (Typ)
5582 and then not Is_Constrained (Typ)
5583 and then not Machine_Overflows_On_Target
5586 ("float division by zero, may generate "
5587 & "'+'/'- infinity??", Right_Opnd (N));
5589 -- For all other cases, we get a Constraint_Error
5592 Apply_Compile_Time_Constraint_Error
5593 (N, "division by zero??", CE_Divide_By_Zero,
5594 Loc => Sloc (Right_Opnd (N)));
5598 Apply_Compile_Time_Constraint_Error
5599 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5600 Loc => Sloc (Right_Opnd (N)));
5603 Apply_Compile_Time_Constraint_Error
5604 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5605 Loc => Sloc (Right_Opnd (N)));
5607 -- Division by zero can only happen with division, rem,
5608 -- and mod operations.
5611 raise Program_Error;
5614 -- Otherwise just set the flag to check at run time
5617 Activate_Division_Check (N);
5621 -- If Restriction No_Implicit_Conditionals is active, then it is
5622 -- violated if either operand can be negative for mod, or for rem
5623 -- if both operands can be negative.
5625 if Restriction_Check_Required (No_Implicit_Conditionals)
5626 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5635 -- Set if corresponding operand might be negative
5639 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5640 LNeg := (not OK) or else Lo < 0;
5643 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5644 RNeg := (not OK) or else Lo < 0;
5646 -- Check if we will be generating conditionals. There are two
5647 -- cases where that can happen, first for REM, the only case
5648 -- is largest negative integer mod -1, where the division can
5649 -- overflow, but we still have to give the right result. The
5650 -- front end generates a test for this annoying case. Here we
5651 -- just test if both operands can be negative (that's what the
5652 -- expander does, so we match its logic here).
5654 -- The second case is mod where either operand can be negative.
5655 -- In this case, the back end has to generate additional tests.
5657 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5659 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5661 Check_Restriction (No_Implicit_Conditionals, N);
5667 Check_Unset_Reference (L);
5668 Check_Unset_Reference (R);
5669 Check_Function_Writable_Actuals (N);
5670 end Resolve_Arithmetic_Op;
5676 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5677 function Same_Or_Aliased_Subprograms
5679 E : Entity_Id) return Boolean;
5680 -- Returns True if the subprogram entity S is the same as E or else
5681 -- S is an alias of E.
5683 ---------------------------------
5684 -- Same_Or_Aliased_Subprograms --
5685 ---------------------------------
5687 function Same_Or_Aliased_Subprograms
5689 E : Entity_Id) return Boolean
5691 Subp_Alias : constant Entity_Id := Alias (S);
5693 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5694 end Same_Or_Aliased_Subprograms;
5698 Loc : constant Source_Ptr := Sloc (N);
5699 Subp : constant Node_Id := Name (N);
5700 Body_Id : Entity_Id;
5710 -- Start of processing for Resolve_Call
5713 -- The context imposes a unique interpretation with type Typ on a
5714 -- procedure or function call. Find the entity of the subprogram that
5715 -- yields the expected type, and propagate the corresponding formal
5716 -- constraints on the actuals. The caller has established that an
5717 -- interpretation exists, and emitted an error if not unique.
5719 -- First deal with the case of a call to an access-to-subprogram,
5720 -- dereference made explicit in Analyze_Call.
5722 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5723 if not Is_Overloaded (Subp) then
5724 Nam := Etype (Subp);
5727 -- Find the interpretation whose type (a subprogram type) has a
5728 -- return type that is compatible with the context. Analysis of
5729 -- the node has established that one exists.
5733 Get_First_Interp (Subp, I, It);
5734 while Present (It.Typ) loop
5735 if Covers (Typ, Etype (It.Typ)) then
5740 Get_Next_Interp (I, It);
5744 raise Program_Error;
5748 -- If the prefix is not an entity, then resolve it
5750 if not Is_Entity_Name (Subp) then
5751 Resolve (Subp, Nam);
5754 -- For an indirect call, we always invalidate checks, since we do not
5755 -- know whether the subprogram is local or global. Yes we could do
5756 -- better here, e.g. by knowing that there are no local subprograms,
5757 -- but it does not seem worth the effort. Similarly, we kill all
5758 -- knowledge of current constant values.
5760 Kill_Current_Values;
5762 -- If this is a procedure call which is really an entry call, do
5763 -- the conversion of the procedure call to an entry call. Protected
5764 -- operations use the same circuitry because the name in the call
5765 -- can be an arbitrary expression with special resolution rules.
5767 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5768 or else (Is_Entity_Name (Subp)
5769 and then Ekind (Entity (Subp)) = E_Entry)
5771 Resolve_Entry_Call (N, Typ);
5772 Check_Elab_Call (N);
5774 -- Kill checks and constant values, as above for indirect case
5775 -- Who knows what happens when another task is activated?
5777 Kill_Current_Values;
5780 -- Normal subprogram call with name established in Resolve
5782 elsif not (Is_Type (Entity (Subp))) then
5783 Nam := Entity (Subp);
5784 Set_Entity_With_Checks (Subp, Nam);
5786 -- Otherwise we must have the case of an overloaded call
5789 pragma Assert (Is_Overloaded (Subp));
5791 -- Initialize Nam to prevent warning (we know it will be assigned
5792 -- in the loop below, but the compiler does not know that).
5796 Get_First_Interp (Subp, I, It);
5797 while Present (It.Typ) loop
5798 if Covers (Typ, It.Typ) then
5800 Set_Entity_With_Checks (Subp, Nam);
5804 Get_Next_Interp (I, It);
5808 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5809 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5810 and then Nkind (Subp) /= N_Explicit_Dereference
5811 and then Present (Parameter_Associations (N))
5813 -- The prefix is a parameterless function call that returns an access
5814 -- to subprogram. If parameters are present in the current call, add
5815 -- add an explicit dereference. We use the base type here because
5816 -- within an instance these may be subtypes.
5818 -- The dereference is added either in Analyze_Call or here. Should
5819 -- be consolidated ???
5821 Set_Is_Overloaded (Subp, False);
5822 Set_Etype (Subp, Etype (Nam));
5823 Insert_Explicit_Dereference (Subp);
5824 Nam := Designated_Type (Etype (Nam));
5825 Resolve (Subp, Nam);
5828 -- Check that a call to Current_Task does not occur in an entry body
5830 if Is_RTE (Nam, RE_Current_Task) then
5839 -- Exclude calls that occur within the default of a formal
5840 -- parameter of the entry, since those are evaluated outside
5843 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5845 if Nkind (P) = N_Entry_Body
5846 or else (Nkind (P) = N_Subprogram_Body
5847 and then Is_Entry_Barrier_Function (P))
5850 Error_Msg_Warn := SPARK_Mode /= On;
5852 ("& should not be used in entry body (RM C.7(17))<<",
5854 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5856 Make_Raise_Program_Error (Loc,
5857 Reason => PE_Current_Task_In_Entry_Body));
5858 Set_Etype (N, Rtype);
5865 -- Check that a procedure call does not occur in the context of the
5866 -- entry call statement of a conditional or timed entry call. Note that
5867 -- the case of a call to a subprogram renaming of an entry will also be
5868 -- rejected. The test for N not being an N_Entry_Call_Statement is
5869 -- defensive, covering the possibility that the processing of entry
5870 -- calls might reach this point due to later modifications of the code
5873 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5874 and then Nkind (N) /= N_Entry_Call_Statement
5875 and then Entry_Call_Statement (Parent (N)) = N
5877 if Ada_Version < Ada_2005 then
5878 Error_Msg_N ("entry call required in select statement", N);
5880 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5881 -- for a procedure_or_entry_call, the procedure_name or
5882 -- procedure_prefix of the procedure_call_statement shall denote
5883 -- an entry renamed by a procedure, or (a view of) a primitive
5884 -- subprogram of a limited interface whose first parameter is
5885 -- a controlling parameter.
5887 elsif Nkind (N) = N_Procedure_Call_Statement
5888 and then not Is_Renamed_Entry (Nam)
5889 and then not Is_Controlling_Limited_Procedure (Nam)
5892 ("entry call or dispatching primitive of interface required", N);
5896 -- If the SPARK_05 restriction is active, we are not allowed
5897 -- to have a call to a subprogram before we see its completion.
5899 if not Has_Completion (Nam)
5900 and then Restriction_Check_Required (SPARK_05)
5902 -- Don't flag strange internal calls
5904 and then Comes_From_Source (N)
5905 and then Comes_From_Source (Nam)
5907 -- Only flag calls in extended main source
5909 and then In_Extended_Main_Source_Unit (Nam)
5910 and then In_Extended_Main_Source_Unit (N)
5912 -- Exclude enumeration literals from this processing
5914 and then Ekind (Nam) /= E_Enumeration_Literal
5916 Check_SPARK_05_Restriction
5917 ("call to subprogram cannot appear before its body", N);
5920 -- Check that this is not a call to a protected procedure or entry from
5921 -- within a protected function.
5923 Check_Internal_Protected_Use (N, Nam);
5925 -- Freeze the subprogram name if not in a spec-expression. Note that
5926 -- we freeze procedure calls as well as function calls. Procedure calls
5927 -- are not frozen according to the rules (RM 13.14(14)) because it is
5928 -- impossible to have a procedure call to a non-frozen procedure in
5929 -- pure Ada, but in the code that we generate in the expander, this
5930 -- rule needs extending because we can generate procedure calls that
5933 -- In Ada 2012, expression functions may be called within pre/post
5934 -- conditions of subsequent functions or expression functions. Such
5935 -- calls do not freeze when they appear within generated bodies,
5936 -- (including the body of another expression function) which would
5937 -- place the freeze node in the wrong scope. An expression function
5938 -- is frozen in the usual fashion, by the appearance of a real body,
5939 -- or at the end of a declarative part.
5941 if Is_Entity_Name (Subp) and then not In_Spec_Expression
5942 and then not Is_Expression_Function (Current_Scope)
5944 (not Is_Expression_Function (Entity (Subp))
5945 or else Scope (Entity (Subp)) = Current_Scope)
5947 Freeze_Expression (Subp);
5950 -- For a predefined operator, the type of the result is the type imposed
5951 -- by context, except for a predefined operation on universal fixed.
5952 -- Otherwise The type of the call is the type returned by the subprogram
5955 if Is_Predefined_Op (Nam) then
5956 if Etype (N) /= Universal_Fixed then
5960 -- If the subprogram returns an array type, and the context requires the
5961 -- component type of that array type, the node is really an indexing of
5962 -- the parameterless call. Resolve as such. A pathological case occurs
5963 -- when the type of the component is an access to the array type. In
5964 -- this case the call is truly ambiguous.
5966 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5968 ((Is_Array_Type (Etype (Nam))
5969 and then Covers (Typ, Component_Type (Etype (Nam))))
5971 (Is_Access_Type (Etype (Nam))
5972 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5974 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5977 Index_Node : Node_Id;
5979 Ret_Type : constant Entity_Id := Etype (Nam);
5982 if Is_Access_Type (Ret_Type)
5983 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5986 ("cannot disambiguate function call and indexing", N);
5988 New_Subp := Relocate_Node (Subp);
5990 -- The called entity may be an explicit dereference, in which
5991 -- case there is no entity to set.
5993 if Nkind (New_Subp) /= N_Explicit_Dereference then
5994 Set_Entity (Subp, Nam);
5997 if (Is_Array_Type (Ret_Type)
5998 and then Component_Type (Ret_Type) /= Any_Type)
6000 (Is_Access_Type (Ret_Type)
6002 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
6004 if Needs_No_Actuals (Nam) then
6006 -- Indexed call to a parameterless function
6009 Make_Indexed_Component (Loc,
6011 Make_Function_Call (Loc, Name => New_Subp),
6012 Expressions => Parameter_Associations (N));
6014 -- An Ada 2005 prefixed call to a primitive operation
6015 -- whose first parameter is the prefix. This prefix was
6016 -- prepended to the parameter list, which is actually a
6017 -- list of indexes. Remove the prefix in order to build
6018 -- the proper indexed component.
6021 Make_Indexed_Component (Loc,
6023 Make_Function_Call (Loc,
6025 Parameter_Associations =>
6027 (Remove_Head (Parameter_Associations (N)))),
6028 Expressions => Parameter_Associations (N));
6031 -- Preserve the parenthesis count of the node
6033 Set_Paren_Count (Index_Node, Paren_Count (N));
6035 -- Since we are correcting a node classification error made
6036 -- by the parser, we call Replace rather than Rewrite.
6038 Replace (N, Index_Node);
6040 Set_Etype (Prefix (N), Ret_Type);
6042 Resolve_Indexed_Component (N, Typ);
6043 Check_Elab_Call (Prefix (N));
6051 Set_Etype (N, Etype (Nam));
6054 -- In the case where the call is to an overloaded subprogram, Analyze
6055 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6056 -- such a case Normalize_Actuals needs to be called once more to order
6057 -- the actuals correctly. Otherwise the call will have the ordering
6058 -- given by the last overloaded subprogram whether this is the correct
6059 -- one being called or not.
6061 if Is_Overloaded (Subp) then
6062 Normalize_Actuals (N, Nam, False, Norm_OK);
6063 pragma Assert (Norm_OK);
6066 -- In any case, call is fully resolved now. Reset Overload flag, to
6067 -- prevent subsequent overload resolution if node is analyzed again
6069 Set_Is_Overloaded (Subp, False);
6070 Set_Is_Overloaded (N, False);
6072 -- A Ghost entity must appear in a specific context
6074 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6075 Check_Ghost_Context (Nam, N);
6078 -- If we are calling the current subprogram from immediately within its
6079 -- body, then that is the case where we can sometimes detect cases of
6080 -- infinite recursion statically. Do not try this in case restriction
6081 -- No_Recursion is in effect anyway, and do it only for source calls.
6083 if Comes_From_Source (N) then
6084 Scop := Current_Scope;
6086 -- Check violation of SPARK_05 restriction which does not permit
6087 -- a subprogram body to contain a call to the subprogram directly.
6089 if Restriction_Check_Required (SPARK_05)
6090 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6092 Check_SPARK_05_Restriction
6093 ("subprogram may not contain direct call to itself", N);
6096 -- Issue warning for possible infinite recursion in the absence
6097 -- of the No_Recursion restriction.
6099 if Same_Or_Aliased_Subprograms (Nam, Scop)
6100 and then not Restriction_Active (No_Recursion)
6101 and then Check_Infinite_Recursion (N)
6103 -- Here we detected and flagged an infinite recursion, so we do
6104 -- not need to test the case below for further warnings. Also we
6105 -- are all done if we now have a raise SE node.
6107 if Nkind (N) = N_Raise_Storage_Error then
6111 -- If call is to immediately containing subprogram, then check for
6112 -- the case of a possible run-time detectable infinite recursion.
6115 Scope_Loop : while Scop /= Standard_Standard loop
6116 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6118 -- Although in general case, recursion is not statically
6119 -- checkable, the case of calling an immediately containing
6120 -- subprogram is easy to catch.
6122 Check_Restriction (No_Recursion, N);
6124 -- If the recursive call is to a parameterless subprogram,
6125 -- then even if we can't statically detect infinite
6126 -- recursion, this is pretty suspicious, and we output a
6127 -- warning. Furthermore, we will try later to detect some
6128 -- cases here at run time by expanding checking code (see
6129 -- Detect_Infinite_Recursion in package Exp_Ch6).
6131 -- If the recursive call is within a handler, do not emit a
6132 -- warning, because this is a common idiom: loop until input
6133 -- is correct, catch illegal input in handler and restart.
6135 if No (First_Formal (Nam))
6136 and then Etype (Nam) = Standard_Void_Type
6137 and then not Error_Posted (N)
6138 and then Nkind (Parent (N)) /= N_Exception_Handler
6140 -- For the case of a procedure call. We give the message
6141 -- only if the call is the first statement in a sequence
6142 -- of statements, or if all previous statements are
6143 -- simple assignments. This is simply a heuristic to
6144 -- decrease false positives, without losing too many good
6145 -- warnings. The idea is that these previous statements
6146 -- may affect global variables the procedure depends on.
6147 -- We also exclude raise statements, that may arise from
6148 -- constraint checks and are probably unrelated to the
6149 -- intended control flow.
6151 if Nkind (N) = N_Procedure_Call_Statement
6152 and then Is_List_Member (N)
6158 while Present (P) loop
6159 if not Nkind_In (P, N_Assignment_Statement,
6160 N_Raise_Constraint_Error)
6170 -- Do not give warning if we are in a conditional context
6173 K : constant Node_Kind := Nkind (Parent (N));
6175 if (K = N_Loop_Statement
6176 and then Present (Iteration_Scheme (Parent (N))))
6177 or else K = N_If_Statement
6178 or else K = N_Elsif_Part
6179 or else K = N_Case_Statement_Alternative
6185 -- Here warning is to be issued
6187 Set_Has_Recursive_Call (Nam);
6188 Error_Msg_Warn := SPARK_Mode /= On;
6189 Error_Msg_N ("possible infinite recursion<<!", N);
6190 Error_Msg_N ("\Storage_Error ]<<!", N);
6196 Scop := Scope (Scop);
6197 end loop Scope_Loop;
6201 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6203 Check_Obsolescent_2005_Entity (Nam, Subp);
6205 -- If subprogram name is a predefined operator, it was given in
6206 -- functional notation. Replace call node with operator node, so
6207 -- that actuals can be resolved appropriately.
6209 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6210 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6213 elsif Present (Alias (Nam))
6214 and then Is_Predefined_Op (Alias (Nam))
6216 Resolve_Actuals (N, Nam);
6217 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6221 -- Create a transient scope if the resulting type requires it
6223 -- There are several notable exceptions:
6225 -- a) In init procs, the transient scope overhead is not needed, and is
6226 -- even incorrect when the call is a nested initialization call for a
6227 -- component whose expansion may generate adjust calls. However, if the
6228 -- call is some other procedure call within an initialization procedure
6229 -- (for example a call to Create_Task in the init_proc of the task
6230 -- run-time record) a transient scope must be created around this call.
6232 -- b) Enumeration literal pseudo-calls need no transient scope
6234 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6235 -- functions) do not use the secondary stack even though the return
6236 -- type may be unconstrained.
6238 -- d) Calls to a build-in-place function, since such functions may
6239 -- allocate their result directly in a target object, and cases where
6240 -- the result does get allocated in the secondary stack are checked for
6241 -- within the specialized Exp_Ch6 procedures for expanding those
6242 -- build-in-place calls.
6244 -- e) If the subprogram is marked Inline_Always, then even if it returns
6245 -- an unconstrained type the call does not require use of the secondary
6246 -- stack. However, inlining will only take place if the body to inline
6247 -- is already present. It may not be available if e.g. the subprogram is
6248 -- declared in a child instance.
6250 -- If this is an initialization call for a type whose construction
6251 -- uses the secondary stack, and it is not a nested call to initialize
6252 -- a component, we do need to create a transient scope for it. We
6253 -- check for this by traversing the type in Check_Initialization_Call.
6256 and then Has_Pragma_Inline (Nam)
6257 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6258 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6262 elsif Ekind (Nam) = E_Enumeration_Literal
6263 or else Is_Build_In_Place_Function (Nam)
6264 or else Is_Intrinsic_Subprogram (Nam)
6268 elsif Expander_Active
6269 and then Is_Type (Etype (Nam))
6270 and then Requires_Transient_Scope (Etype (Nam))
6272 (not Within_Init_Proc
6274 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6276 Establish_Transient_Scope (N, Sec_Stack => True);
6278 -- If the call appears within the bounds of a loop, it will
6279 -- be rewritten and reanalyzed, nothing left to do here.
6281 if Nkind (N) /= N_Function_Call then
6285 elsif Is_Init_Proc (Nam)
6286 and then not Within_Init_Proc
6288 Check_Initialization_Call (N, Nam);
6291 -- A protected function cannot be called within the definition of the
6292 -- enclosing protected type, unless it is part of a pre/postcondition
6293 -- on another protected operation.
6295 if Is_Protected_Type (Scope (Nam))
6296 and then In_Open_Scopes (Scope (Nam))
6297 and then not Has_Completion (Scope (Nam))
6298 and then not In_Spec_Expression
6301 ("& cannot be called before end of protected definition", N, Nam);
6304 -- Propagate interpretation to actuals, and add default expressions
6307 if Present (First_Formal (Nam)) then
6308 Resolve_Actuals (N, Nam);
6310 -- Overloaded literals are rewritten as function calls, for purpose of
6311 -- resolution. After resolution, we can replace the call with the
6314 elsif Ekind (Nam) = E_Enumeration_Literal then
6315 Copy_Node (Subp, N);
6316 Resolve_Entity_Name (N, Typ);
6318 -- Avoid validation, since it is a static function call
6320 Generate_Reference (Nam, Subp);
6324 -- If the subprogram is not global, then kill all saved values and
6325 -- checks. This is a bit conservative, since in many cases we could do
6326 -- better, but it is not worth the effort. Similarly, we kill constant
6327 -- values. However we do not need to do this for internal entities
6328 -- (unless they are inherited user-defined subprograms), since they
6329 -- are not in the business of molesting local values.
6331 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6332 -- kill all checks and values for calls to global subprograms. This
6333 -- takes care of the case where an access to a local subprogram is
6334 -- taken, and could be passed directly or indirectly and then called
6335 -- from almost any context.
6337 -- Note: we do not do this step till after resolving the actuals. That
6338 -- way we still take advantage of the current value information while
6339 -- scanning the actuals.
6341 -- We suppress killing values if we are processing the nodes associated
6342 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6343 -- type kills all the values as part of analyzing the code that
6344 -- initializes the dispatch tables.
6346 if Inside_Freezing_Actions = 0
6347 and then (not Is_Library_Level_Entity (Nam)
6348 or else Suppress_Value_Tracking_On_Call
6349 (Nearest_Dynamic_Scope (Current_Scope)))
6350 and then (Comes_From_Source (Nam)
6351 or else (Present (Alias (Nam))
6352 and then Comes_From_Source (Alias (Nam))))
6354 Kill_Current_Values;
6357 -- If we are warning about unread OUT parameters, this is the place to
6358 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6359 -- after the above call to Kill_Current_Values (since that call clears
6360 -- the Last_Assignment field of all local variables).
6362 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6363 and then Comes_From_Source (N)
6364 and then In_Extended_Main_Source_Unit (N)
6371 F := First_Formal (Nam);
6372 A := First_Actual (N);
6373 while Present (F) and then Present (A) loop
6374 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6375 and then Warn_On_Modified_As_Out_Parameter (F)
6376 and then Is_Entity_Name (A)
6377 and then Present (Entity (A))
6378 and then Comes_From_Source (N)
6379 and then Safe_To_Capture_Value (N, Entity (A))
6381 Set_Last_Assignment (Entity (A), A);
6390 -- If the subprogram is a primitive operation, check whether or not
6391 -- it is a correct dispatching call.
6393 if Is_Overloadable (Nam)
6394 and then Is_Dispatching_Operation (Nam)
6396 Check_Dispatching_Call (N);
6398 elsif Ekind (Nam) /= E_Subprogram_Type
6399 and then Is_Abstract_Subprogram (Nam)
6400 and then not In_Instance
6402 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6405 -- If this is a dispatching call, generate the appropriate reference,
6406 -- for better source navigation in GPS.
6408 if Is_Overloadable (Nam)
6409 and then Present (Controlling_Argument (N))
6411 Generate_Reference (Nam, Subp, 'R');
6413 -- Normal case, not a dispatching call: generate a call reference
6416 Generate_Reference (Nam, Subp, 's');
6419 if Is_Intrinsic_Subprogram (Nam) then
6420 Check_Intrinsic_Call (N);
6423 -- Check for violation of restriction No_Specific_Termination_Handlers
6424 -- and warn on a potentially blocking call to Abort_Task.
6426 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6427 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6429 Is_RTE (Nam, RE_Specific_Handler))
6431 Check_Restriction (No_Specific_Termination_Handlers, N);
6433 elsif Is_RTE (Nam, RE_Abort_Task) then
6434 Check_Potentially_Blocking_Operation (N);
6437 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6438 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6439 -- need to check the second argument to determine whether it is an
6440 -- absolute or relative timing event.
6442 if Restriction_Check_Required (No_Relative_Delay)
6443 and then Is_RTE (Nam, RE_Set_Handler)
6444 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6446 Check_Restriction (No_Relative_Delay, N);
6449 -- Issue an error for a call to an eliminated subprogram. This routine
6450 -- will not perform the check if the call appears within a default
6453 Check_For_Eliminated_Subprogram (Subp, Nam);
6455 -- In formal mode, the primitive operations of a tagged type or type
6456 -- extension do not include functions that return the tagged type.
6458 if Nkind (N) = N_Function_Call
6459 and then Is_Tagged_Type (Etype (N))
6460 and then Is_Entity_Name (Name (N))
6461 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6463 Check_SPARK_05_Restriction ("function not inherited", N);
6466 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6467 -- class-wide and the call dispatches on result in a context that does
6468 -- not provide a tag, the call raises Program_Error.
6470 if Nkind (N) = N_Function_Call
6471 and then In_Instance
6472 and then Is_Generic_Actual_Type (Typ)
6473 and then Is_Class_Wide_Type (Typ)
6474 and then Has_Controlling_Result (Nam)
6475 and then Nkind (Parent (N)) = N_Object_Declaration
6477 -- Verify that none of the formals are controlling
6480 Call_OK : Boolean := False;
6484 F := First_Formal (Nam);
6485 while Present (F) loop
6486 if Is_Controlling_Formal (F) then
6495 Error_Msg_Warn := SPARK_Mode /= On;
6496 Error_Msg_N ("!cannot determine tag of result<<", N);
6497 Error_Msg_N ("\Program_Error [<<!", N);
6499 Make_Raise_Program_Error (Sloc (N),
6500 Reason => PE_Explicit_Raise));
6505 -- Check for calling a function with OUT or IN OUT parameter when the
6506 -- calling context (us right now) is not Ada 2012, so does not allow
6507 -- OUT or IN OUT parameters in function calls.
6509 if Ada_Version < Ada_2012
6510 and then Ekind (Nam) = E_Function
6511 and then Has_Out_Or_In_Out_Parameter (Nam)
6513 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6514 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6517 -- Check the dimensions of the actuals in the call. For function calls,
6518 -- propagate the dimensions from the returned type to N.
6520 Analyze_Dimension_Call (N, Nam);
6522 -- All done, evaluate call and deal with elaboration issues
6525 Check_Elab_Call (N);
6527 -- In GNATprove mode, expansion is disabled, but we want to inline some
6528 -- subprograms to facilitate formal verification. Indirect calls through
6529 -- a subprogram type or within a generic cannot be inlined. Inlining is
6530 -- performed only for calls subject to SPARK_Mode on.
6533 and then SPARK_Mode = On
6534 and then Is_Overloadable (Nam)
6535 and then not Inside_A_Generic
6537 Nam_UA := Ultimate_Alias (Nam);
6538 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6540 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6541 Body_Id := Corresponding_Body (Nam_Decl);
6543 -- Nothing to do if the subprogram is not eligible for inlining in
6546 if not Is_Inlined_Always (Nam_UA)
6547 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6551 -- Calls cannot be inlined inside assertions, as GNATprove treats
6552 -- assertions as logic expressions.
6554 elsif In_Assertion_Expr /= 0 then
6555 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6556 Error_Msg_N ("\call appears in assertion expression", N);
6557 Set_Is_Inlined_Always (Nam_UA, False);
6559 -- Calls cannot be inlined inside default expressions
6561 elsif In_Default_Expr then
6562 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6563 Error_Msg_N ("\call appears in default expression", N);
6564 Set_Is_Inlined_Always (Nam_UA, False);
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 ("?no contextual analysis of & (body not seen yet)",
6577 Set_Is_Inlined_Always (Nam_UA, False);
6579 -- Nothing to do if there is no body to inline, indicating that
6580 -- the subprogram is not suitable for inlining in GNATprove
6583 elsif No (Body_To_Inline (Nam_Decl)) then
6586 -- Calls cannot be inlined inside potentially unevaluated
6587 -- expressions, as this would create complex actions inside
6588 -- expressions, that are not handled by GNATprove.
6590 elsif Is_Potentially_Unevaluated (N) then
6591 Error_Msg_NE ("?no contextual analysis of &", N, Nam);
6593 ("\call appears in potentially unevaluated context", N);
6594 Set_Is_Inlined_Always (Nam_UA, False);
6596 -- Otherwise, inline the call
6599 Expand_Inlined_Call (N, Nam_UA, Nam);
6605 Warn_On_Overlapping_Actuals (Nam, N);
6608 -----------------------------
6609 -- Resolve_Case_Expression --
6610 -----------------------------
6612 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6616 Alt := First (Alternatives (N));
6617 while Present (Alt) loop
6618 Resolve (Expression (Alt), Typ);
6623 Eval_Case_Expression (N);
6624 end Resolve_Case_Expression;
6626 -------------------------------
6627 -- Resolve_Character_Literal --
6628 -------------------------------
6630 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6631 B_Typ : constant Entity_Id := Base_Type (Typ);
6635 -- Verify that the character does belong to the type of the context
6637 Set_Etype (N, B_Typ);
6638 Eval_Character_Literal (N);
6640 -- Wide_Wide_Character literals must always be defined, since the set
6641 -- of wide wide character literals is complete, i.e. if a character
6642 -- literal is accepted by the parser, then it is OK for wide wide
6643 -- character (out of range character literals are rejected).
6645 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6648 -- Always accept character literal for type Any_Character, which
6649 -- occurs in error situations and in comparisons of literals, both
6650 -- of which should accept all literals.
6652 elsif B_Typ = Any_Character then
6655 -- For Standard.Character or a type derived from it, check that the
6656 -- literal is in range.
6658 elsif Root_Type (B_Typ) = Standard_Character then
6659 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6663 -- For Standard.Wide_Character or a type derived from it, check that the
6664 -- literal is in range.
6666 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6667 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6671 -- For Standard.Wide_Wide_Character or a type derived from it, we
6672 -- know the literal is in range, since the parser checked.
6674 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6677 -- If the entity is already set, this has already been resolved in a
6678 -- generic context, or comes from expansion. Nothing else to do.
6680 elsif Present (Entity (N)) then
6683 -- Otherwise we have a user defined character type, and we can use the
6684 -- standard visibility mechanisms to locate the referenced entity.
6687 C := Current_Entity (N);
6688 while Present (C) loop
6689 if Etype (C) = B_Typ then
6690 Set_Entity_With_Checks (N, C);
6691 Generate_Reference (C, N);
6699 -- If we fall through, then the literal does not match any of the
6700 -- entries of the enumeration type. This isn't just a constraint error
6701 -- situation, it is an illegality (see RM 4.2).
6704 ("character not defined for }", N, First_Subtype (B_Typ));
6705 end Resolve_Character_Literal;
6707 ---------------------------
6708 -- Resolve_Comparison_Op --
6709 ---------------------------
6711 -- Context requires a boolean type, and plays no role in resolution.
6712 -- Processing identical to that for equality operators. The result type is
6713 -- the base type, which matters when pathological subtypes of booleans with
6714 -- limited ranges are used.
6716 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6717 L : constant Node_Id := Left_Opnd (N);
6718 R : constant Node_Id := Right_Opnd (N);
6722 -- If this is an intrinsic operation which is not predefined, use the
6723 -- types of its declared arguments to resolve the possibly overloaded
6724 -- operands. Otherwise the operands are unambiguous and specify the
6727 if Scope (Entity (N)) /= Standard_Standard then
6728 T := Etype (First_Entity (Entity (N)));
6731 T := Find_Unique_Type (L, R);
6733 if T = Any_Fixed then
6734 T := Unique_Fixed_Point_Type (L);
6738 Set_Etype (N, Base_Type (Typ));
6739 Generate_Reference (T, N, ' ');
6741 -- Skip remaining processing if already set to Any_Type
6743 if T = Any_Type then
6747 -- Deal with other error cases
6749 if T = Any_String or else
6750 T = Any_Composite or else
6753 if T = Any_Character then
6754 Ambiguous_Character (L);
6756 Error_Msg_N ("ambiguous operands for comparison", N);
6759 Set_Etype (N, Any_Type);
6763 -- Resolve the operands if types OK
6767 Check_Unset_Reference (L);
6768 Check_Unset_Reference (R);
6769 Generate_Operator_Reference (N, T);
6770 Check_Low_Bound_Tested (N);
6772 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6773 -- types or array types except String.
6775 if Is_Boolean_Type (T) then
6776 Check_SPARK_05_Restriction
6777 ("comparison is not defined on Boolean type", N);
6779 elsif Is_Array_Type (T)
6780 and then Base_Type (T) /= Standard_String
6782 Check_SPARK_05_Restriction
6783 ("comparison is not defined on array types other than String", N);
6786 -- Check comparison on unordered enumeration
6788 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6789 Error_Msg_Sloc := Sloc (Etype (L));
6791 ("comparison on unordered enumeration type& declared#?U?",
6795 -- Evaluate the relation (note we do this after the above check since
6796 -- this Eval call may change N to True/False.
6798 Analyze_Dimension (N);
6799 Eval_Relational_Op (N);
6800 end Resolve_Comparison_Op;
6802 -----------------------------------------
6803 -- Resolve_Discrete_Subtype_Indication --
6804 -----------------------------------------
6806 procedure Resolve_Discrete_Subtype_Indication
6814 Analyze (Subtype_Mark (N));
6815 S := Entity (Subtype_Mark (N));
6817 if Nkind (Constraint (N)) /= N_Range_Constraint then
6818 Error_Msg_N ("expect range constraint for discrete type", N);
6819 Set_Etype (N, Any_Type);
6822 R := Range_Expression (Constraint (N));
6830 if Base_Type (S) /= Base_Type (Typ) then
6832 ("expect subtype of }", N, First_Subtype (Typ));
6834 -- Rewrite the constraint as a range of Typ
6835 -- to allow compilation to proceed further.
6838 Rewrite (Low_Bound (R),
6839 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6840 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6841 Attribute_Name => Name_First));
6842 Rewrite (High_Bound (R),
6843 Make_Attribute_Reference (Sloc (High_Bound (R)),
6844 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6845 Attribute_Name => Name_First));
6849 Set_Etype (N, Etype (R));
6851 -- Additionally, we must check that the bounds are compatible
6852 -- with the given subtype, which might be different from the
6853 -- type of the context.
6855 Apply_Range_Check (R, S);
6857 -- ??? If the above check statically detects a Constraint_Error
6858 -- it replaces the offending bound(s) of the range R with a
6859 -- Constraint_Error node. When the itype which uses these bounds
6860 -- is frozen the resulting call to Duplicate_Subexpr generates
6861 -- a new temporary for the bounds.
6863 -- Unfortunately there are other itypes that are also made depend
6864 -- on these bounds, so when Duplicate_Subexpr is called they get
6865 -- a forward reference to the newly created temporaries and Gigi
6866 -- aborts on such forward references. This is probably sign of a
6867 -- more fundamental problem somewhere else in either the order of
6868 -- itype freezing or the way certain itypes are constructed.
6870 -- To get around this problem we call Remove_Side_Effects right
6871 -- away if either bounds of R are a Constraint_Error.
6874 L : constant Node_Id := Low_Bound (R);
6875 H : constant Node_Id := High_Bound (R);
6878 if Nkind (L) = N_Raise_Constraint_Error then
6879 Remove_Side_Effects (L);
6882 if Nkind (H) = N_Raise_Constraint_Error then
6883 Remove_Side_Effects (H);
6887 Check_Unset_Reference (Low_Bound (R));
6888 Check_Unset_Reference (High_Bound (R));
6891 end Resolve_Discrete_Subtype_Indication;
6893 -------------------------
6894 -- Resolve_Entity_Name --
6895 -------------------------
6897 -- Used to resolve identifiers and expanded names
6899 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6900 function Is_OK_Volatile_Context
6902 Obj_Ref : Node_Id) return Boolean;
6903 -- Determine whether node Context denotes a "non-interfering context"
6904 -- (as defined in SPARK RM 7.1.3(13)) where volatile reference Obj_Ref
6905 -- can safely reside.
6907 ----------------------------
6908 -- Is_OK_Volatile_Context --
6909 ----------------------------
6911 function Is_OK_Volatile_Context
6913 Obj_Ref : Node_Id) return Boolean
6915 function Within_Check (Nod : Node_Id) return Boolean;
6916 -- Determine whether an arbitrary node appears in a check node
6918 function Within_Procedure_Call (Nod : Node_Id) return Boolean;
6919 -- Determine whether an arbitrary node appears in a procedure call
6925 function Within_Check (Nod : Node_Id) return Boolean is
6929 -- Climb the parent chain looking for a check node
6932 while Present (Par) loop
6933 if Nkind (Par) in N_Raise_xxx_Error then
6936 -- Prevent the search from going too far
6938 elsif Is_Body_Or_Package_Declaration (Par) then
6942 Par := Parent (Par);
6948 ---------------------------
6949 -- Within_Procedure_Call --
6950 ---------------------------
6952 function Within_Procedure_Call (Nod : Node_Id) return Boolean is
6956 -- Climb the parent chain looking for a procedure call
6959 while Present (Par) loop
6960 if Nkind (Par) = N_Procedure_Call_Statement then
6963 -- Prevent the search from going too far
6965 elsif Is_Body_Or_Package_Declaration (Par) then
6969 Par := Parent (Par);
6973 end Within_Procedure_Call;
6975 -- Start of processing for Is_OK_Volatile_Context
6978 -- The volatile object appears on either side of an assignment
6980 if Nkind (Context) = N_Assignment_Statement then
6983 -- The volatile object is part of the initialization expression of
6984 -- another object. Ensure that the climb of the parent chain came
6985 -- from the expression side and not from the name side.
6987 elsif Nkind (Context) = N_Object_Declaration
6988 and then Present (Expression (Context))
6989 and then Expression (Context) = Obj_Ref
6993 -- The volatile object appears as an actual parameter in a call to an
6994 -- instance of Unchecked_Conversion whose result is renamed.
6996 elsif Nkind (Context) = N_Function_Call
6997 and then Is_Unchecked_Conversion_Instance (Entity (Name (Context)))
6998 and then Nkind (Parent (Context)) = N_Object_Renaming_Declaration
7002 -- The volatile object appears as the prefix of a name occurring
7003 -- in a non-interfering context.
7005 elsif Nkind_In (Context, N_Attribute_Reference,
7006 N_Indexed_Component,
7007 N_Selected_Component,
7009 and then Prefix (Context) = Obj_Ref
7010 and then Is_OK_Volatile_Context
7011 (Context => Parent (Context),
7016 -- The volatile object appears as the expression of a type conversion
7017 -- occurring in a non-interfering context.
7019 elsif Nkind_In (Context, N_Type_Conversion,
7020 N_Unchecked_Type_Conversion)
7021 and then Expression (Context) = Obj_Ref
7022 and then Is_OK_Volatile_Context
7023 (Context => Parent (Context),
7028 -- Allow references to volatile objects in various checks. This is
7029 -- not a direct SPARK 2014 requirement.
7031 elsif Within_Check (Context) then
7034 -- Assume that references to effectively volatile objects that appear
7035 -- as actual parameters in a procedure call are always legal. A full
7036 -- legality check is done when the actuals are resolved.
7038 elsif Within_Procedure_Call (Context) then
7041 -- Otherwise the context is not suitable for an effectively volatile
7047 end Is_OK_Volatile_Context;
7051 E : constant Entity_Id := Entity (N);
7054 -- Start of processing for Resolve_Entity_Name
7057 -- If garbage from errors, set to Any_Type and return
7059 if No (E) and then Total_Errors_Detected /= 0 then
7060 Set_Etype (N, Any_Type);
7064 -- Replace named numbers by corresponding literals. Note that this is
7065 -- the one case where Resolve_Entity_Name must reset the Etype, since
7066 -- it is currently marked as universal.
7068 if Ekind (E) = E_Named_Integer then
7070 Eval_Named_Integer (N);
7072 elsif Ekind (E) = E_Named_Real then
7074 Eval_Named_Real (N);
7076 -- For enumeration literals, we need to make sure that a proper style
7077 -- check is done, since such literals are overloaded, and thus we did
7078 -- not do a style check during the first phase of analysis.
7080 elsif Ekind (E) = E_Enumeration_Literal then
7081 Set_Entity_With_Checks (N, E);
7082 Eval_Entity_Name (N);
7084 -- Case of subtype name appearing as an operand in expression
7086 elsif Is_Type (E) then
7088 -- Allow use of subtype if it is a concurrent type where we are
7089 -- currently inside the body. This will eventually be expanded into a
7090 -- call to Self (for tasks) or _object (for protected objects). Any
7091 -- other use of a subtype is invalid.
7093 if Is_Concurrent_Type (E)
7094 and then In_Open_Scopes (E)
7098 -- Any other use is an error
7102 ("invalid use of subtype mark in expression or call", N);
7105 -- Check discriminant use if entity is discriminant in current scope,
7106 -- i.e. discriminant of record or concurrent type currently being
7107 -- analyzed. Uses in corresponding body are unrestricted.
7109 elsif Ekind (E) = E_Discriminant
7110 and then Scope (E) = Current_Scope
7111 and then not Has_Completion (Current_Scope)
7113 Check_Discriminant_Use (N);
7115 -- A parameterless generic function cannot appear in a context that
7116 -- requires resolution.
7118 elsif Ekind (E) = E_Generic_Function then
7119 Error_Msg_N ("illegal use of generic function", N);
7121 elsif Ekind (E) = E_Out_Parameter
7122 and then Ada_Version = Ada_83
7123 and then (Nkind (Parent (N)) in N_Op
7124 or else (Nkind (Parent (N)) = N_Assignment_Statement
7125 and then N = Expression (Parent (N)))
7126 or else Nkind (Parent (N)) = N_Explicit_Dereference)
7128 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7130 -- In all other cases, just do the possible static evaluation
7133 -- A deferred constant that appears in an expression must have a
7134 -- completion, unless it has been removed by in-place expansion of
7137 if Ekind (E) = E_Constant
7138 and then Comes_From_Source (E)
7139 and then No (Constant_Value (E))
7140 and then Is_Frozen (Etype (E))
7141 and then not In_Spec_Expression
7142 and then not Is_Imported (E)
7144 if No_Initialization (Parent (E))
7145 or else (Present (Full_View (E))
7146 and then No_Initialization (Parent (Full_View (E))))
7151 "deferred constant is frozen before completion", N);
7155 Eval_Entity_Name (N);
7160 -- When the entity appears in a parameter association, retrieve the
7161 -- related subprogram call.
7163 if Nkind (Par) = N_Parameter_Association then
7164 Par := Parent (Par);
7167 -- The following checks are only relevant when SPARK_Mode is on as they
7168 -- are not standard Ada legality rules. An effectively volatile object
7169 -- subject to enabled properties Async_Writers or Effective_Reads must
7170 -- appear in a specific context.
7173 and then Is_Object (E)
7174 and then Is_Effectively_Volatile (E)
7176 (Async_Writers_Enabled (E) or else Effective_Reads_Enabled (E))
7177 and then Comes_From_Source (N)
7179 -- The effectively volatile objects appears in a "non-interfering
7180 -- context" as defined in SPARK RM 7.1.3(13).
7182 if Is_OK_Volatile_Context (Par, N) then
7185 -- Otherwise the context causes a side effect with respect to the
7186 -- effectively volatile object.
7190 ("volatile object cannot appear in this context "
7191 & "(SPARK RM 7.1.3(13))", N);
7195 -- A Ghost entity must appear in a specific context
7197 if Is_Ghost_Entity (E) and then Comes_From_Source (N) then
7198 Check_Ghost_Context (E, N);
7200 end Resolve_Entity_Name;
7206 procedure Resolve_Entry (Entry_Name : Node_Id) is
7207 Loc : constant Source_Ptr := Sloc (Entry_Name);
7215 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7216 -- If the bounds of the entry family being called depend on task
7217 -- discriminants, build a new index subtype where a discriminant is
7218 -- replaced with the value of the discriminant of the target task.
7219 -- The target task is the prefix of the entry name in the call.
7221 -----------------------
7222 -- Actual_Index_Type --
7223 -----------------------
7225 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7226 Typ : constant Entity_Id := Entry_Index_Type (E);
7227 Tsk : constant Entity_Id := Scope (E);
7228 Lo : constant Node_Id := Type_Low_Bound (Typ);
7229 Hi : constant Node_Id := Type_High_Bound (Typ);
7232 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7233 -- If the bound is given by a discriminant, replace with a reference
7234 -- to the discriminant of the same name in the target task. If the
7235 -- entry name is the target of a requeue statement and the entry is
7236 -- in the current protected object, the bound to be used is the
7237 -- discriminal of the object (see Apply_Range_Checks for details of
7238 -- the transformation).
7240 -----------------------------
7241 -- Actual_Discriminant_Ref --
7242 -----------------------------
7244 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7245 Typ : constant Entity_Id := Etype (Bound);
7249 Remove_Side_Effects (Bound);
7251 if not Is_Entity_Name (Bound)
7252 or else Ekind (Entity (Bound)) /= E_Discriminant
7256 elsif Is_Protected_Type (Tsk)
7257 and then In_Open_Scopes (Tsk)
7258 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7260 -- Note: here Bound denotes a discriminant of the corresponding
7261 -- record type tskV, whose discriminal is a formal of the
7262 -- init-proc tskVIP. What we want is the body discriminal,
7263 -- which is associated to the discriminant of the original
7264 -- concurrent type tsk.
7266 return New_Occurrence_Of
7267 (Find_Body_Discriminal (Entity (Bound)), Loc);
7271 Make_Selected_Component (Loc,
7272 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7273 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7278 end Actual_Discriminant_Ref;
7280 -- Start of processing for Actual_Index_Type
7283 if not Has_Discriminants (Tsk)
7284 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7286 return Entry_Index_Type (E);
7289 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7290 Set_Etype (New_T, Base_Type (Typ));
7291 Set_Size_Info (New_T, Typ);
7292 Set_RM_Size (New_T, RM_Size (Typ));
7293 Set_Scalar_Range (New_T,
7294 Make_Range (Sloc (Entry_Name),
7295 Low_Bound => Actual_Discriminant_Ref (Lo),
7296 High_Bound => Actual_Discriminant_Ref (Hi)));
7300 end Actual_Index_Type;
7302 -- Start of processing of Resolve_Entry
7305 -- Find name of entry being called, and resolve prefix of name with its
7306 -- own type. The prefix can be overloaded, and the name and signature of
7307 -- the entry must be taken into account.
7309 if Nkind (Entry_Name) = N_Indexed_Component then
7311 -- Case of dealing with entry family within the current tasks
7313 E_Name := Prefix (Entry_Name);
7316 E_Name := Entry_Name;
7319 if Is_Entity_Name (E_Name) then
7321 -- Entry call to an entry (or entry family) in the current task. This
7322 -- is legal even though the task will deadlock. Rewrite as call to
7325 -- This can also be a call to an entry in an enclosing task. If this
7326 -- is a single task, we have to retrieve its name, because the scope
7327 -- of the entry is the task type, not the object. If the enclosing
7328 -- task is a task type, the identity of the task is given by its own
7331 -- Finally this can be a requeue on an entry of the same task or
7332 -- protected object.
7334 S := Scope (Entity (E_Name));
7336 for J in reverse 0 .. Scope_Stack.Last loop
7337 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7338 and then not Comes_From_Source (S)
7340 -- S is an enclosing task or protected object. The concurrent
7341 -- declaration has been converted into a type declaration, and
7342 -- the object itself has an object declaration that follows
7343 -- the type in the same declarative part.
7345 Tsk := Next_Entity (S);
7346 while Etype (Tsk) /= S loop
7353 elsif S = Scope_Stack.Table (J).Entity then
7355 -- Call to current task. Will be transformed into call to Self
7363 Make_Selected_Component (Loc,
7364 Prefix => New_Occurrence_Of (S, Loc),
7366 New_Occurrence_Of (Entity (E_Name), Loc));
7367 Rewrite (E_Name, New_N);
7370 elsif Nkind (Entry_Name) = N_Selected_Component
7371 and then Is_Overloaded (Prefix (Entry_Name))
7373 -- Use the entry name (which must be unique at this point) to find
7374 -- the prefix that returns the corresponding task/protected type.
7377 Pref : constant Node_Id := Prefix (Entry_Name);
7378 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7383 Get_First_Interp (Pref, I, It);
7384 while Present (It.Typ) loop
7385 if Scope (Ent) = It.Typ then
7386 Set_Etype (Pref, It.Typ);
7390 Get_Next_Interp (I, It);
7395 if Nkind (Entry_Name) = N_Selected_Component then
7396 Resolve (Prefix (Entry_Name));
7398 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7399 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7400 Resolve (Prefix (Prefix (Entry_Name)));
7401 Index := First (Expressions (Entry_Name));
7402 Resolve (Index, Entry_Index_Type (Nam));
7404 -- Up to this point the expression could have been the actual in a
7405 -- simple entry call, and be given by a named association.
7407 if Nkind (Index) = N_Parameter_Association then
7408 Error_Msg_N ("expect expression for entry index", Index);
7410 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7415 ------------------------
7416 -- Resolve_Entry_Call --
7417 ------------------------
7419 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7420 Entry_Name : constant Node_Id := Name (N);
7421 Loc : constant Source_Ptr := Sloc (Entry_Name);
7423 First_Named : Node_Id;
7430 -- We kill all checks here, because it does not seem worth the effort to
7431 -- do anything better, an entry call is a big operation.
7435 -- Processing of the name is similar for entry calls and protected
7436 -- operation calls. Once the entity is determined, we can complete
7437 -- the resolution of the actuals.
7439 -- The selector may be overloaded, in the case of a protected object
7440 -- with overloaded functions. The type of the context is used for
7443 if Nkind (Entry_Name) = N_Selected_Component
7444 and then Is_Overloaded (Selector_Name (Entry_Name))
7445 and then Typ /= Standard_Void_Type
7452 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7453 while Present (It.Typ) loop
7454 if Covers (Typ, It.Typ) then
7455 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7456 Set_Etype (Entry_Name, It.Typ);
7458 Generate_Reference (It.Typ, N, ' ');
7461 Get_Next_Interp (I, It);
7466 Resolve_Entry (Entry_Name);
7468 if Nkind (Entry_Name) = N_Selected_Component then
7470 -- Simple entry call
7472 Nam := Entity (Selector_Name (Entry_Name));
7473 Obj := Prefix (Entry_Name);
7474 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7476 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7478 -- Call to member of entry family
7480 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7481 Obj := Prefix (Prefix (Entry_Name));
7482 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7485 -- We cannot in general check the maximum depth of protected entry calls
7486 -- at compile time. But we can tell that any protected entry call at all
7487 -- violates a specified nesting depth of zero.
7489 if Is_Protected_Type (Scope (Nam)) then
7490 Check_Restriction (Max_Entry_Queue_Length, N);
7493 -- Use context type to disambiguate a protected function that can be
7494 -- called without actuals and that returns an array type, and where the
7495 -- argument list may be an indexing of the returned value.
7497 if Ekind (Nam) = E_Function
7498 and then Needs_No_Actuals (Nam)
7499 and then Present (Parameter_Associations (N))
7501 ((Is_Array_Type (Etype (Nam))
7502 and then Covers (Typ, Component_Type (Etype (Nam))))
7504 or else (Is_Access_Type (Etype (Nam))
7505 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7509 Component_Type (Designated_Type (Etype (Nam))))))
7512 Index_Node : Node_Id;
7516 Make_Indexed_Component (Loc,
7518 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7519 Expressions => Parameter_Associations (N));
7521 -- Since we are correcting a node classification error made by the
7522 -- parser, we call Replace rather than Rewrite.
7524 Replace (N, Index_Node);
7525 Set_Etype (Prefix (N), Etype (Nam));
7527 Resolve_Indexed_Component (N, Typ);
7532 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7533 and then Present (PPC_Wrapper (Nam))
7534 and then Current_Scope /= PPC_Wrapper (Nam)
7536 -- Rewrite as call to the precondition wrapper, adding the task
7537 -- object to the list of actuals. If the call is to a member of an
7538 -- entry family, include the index as well.
7542 New_Actuals : List_Id;
7545 New_Actuals := New_List (Obj);
7547 if Nkind (Entry_Name) = N_Indexed_Component then
7548 Append_To (New_Actuals,
7549 New_Copy_Tree (First (Expressions (Entry_Name))));
7552 Append_List (Parameter_Associations (N), New_Actuals);
7554 Make_Procedure_Call_Statement (Loc,
7556 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
7557 Parameter_Associations => New_Actuals);
7558 Rewrite (N, New_Call);
7560 -- Preanalyze and resolve new call. Current procedure is called
7561 -- from Resolve_Call, after which expansion will take place.
7563 Preanalyze_And_Resolve (N);
7568 -- The operation name may have been overloaded. Order the actuals
7569 -- according to the formals of the resolved entity, and set the return
7570 -- type to that of the operation.
7573 Normalize_Actuals (N, Nam, False, Norm_OK);
7574 pragma Assert (Norm_OK);
7575 Set_Etype (N, Etype (Nam));
7578 Resolve_Actuals (N, Nam);
7579 Check_Internal_Protected_Use (N, Nam);
7581 -- Create a call reference to the entry
7583 Generate_Reference (Nam, Entry_Name, 's');
7585 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7586 Check_Potentially_Blocking_Operation (N);
7589 -- Verify that a procedure call cannot masquerade as an entry
7590 -- call where an entry call is expected.
7592 if Ekind (Nam) = E_Procedure then
7593 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7594 and then N = Entry_Call_Statement (Parent (N))
7596 Error_Msg_N ("entry call required in select statement", N);
7598 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7599 and then N = Triggering_Statement (Parent (N))
7601 Error_Msg_N ("triggering statement cannot be procedure call", N);
7603 elsif Ekind (Scope (Nam)) = E_Task_Type
7604 and then not In_Open_Scopes (Scope (Nam))
7606 Error_Msg_N ("task has no entry with this name", Entry_Name);
7610 -- After resolution, entry calls and protected procedure calls are
7611 -- changed into entry calls, for expansion. The structure of the node
7612 -- does not change, so it can safely be done in place. Protected
7613 -- function calls must keep their structure because they are
7616 if Ekind (Nam) /= E_Function then
7618 -- A protected operation that is not a function may modify the
7619 -- corresponding object, and cannot apply to a constant. If this
7620 -- is an internal call, the prefix is the type itself.
7622 if Is_Protected_Type (Scope (Nam))
7623 and then not Is_Variable (Obj)
7624 and then (not Is_Entity_Name (Obj)
7625 or else not Is_Type (Entity (Obj)))
7628 ("prefix of protected procedure or entry call must be variable",
7632 Actuals := Parameter_Associations (N);
7633 First_Named := First_Named_Actual (N);
7636 Make_Entry_Call_Statement (Loc,
7638 Parameter_Associations => Actuals));
7640 Set_First_Named_Actual (N, First_Named);
7641 Set_Analyzed (N, True);
7643 -- Protected functions can return on the secondary stack, in which
7644 -- case we must trigger the transient scope mechanism.
7646 elsif Expander_Active
7647 and then Requires_Transient_Scope (Etype (Nam))
7649 Establish_Transient_Scope (N, Sec_Stack => True);
7651 end Resolve_Entry_Call;
7653 -------------------------
7654 -- Resolve_Equality_Op --
7655 -------------------------
7657 -- Both arguments must have the same type, and the boolean context does
7658 -- not participate in the resolution. The first pass verifies that the
7659 -- interpretation is not ambiguous, and the type of the left argument is
7660 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7661 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7662 -- though they carry a single (universal) type. Diagnose this case here.
7664 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7665 L : constant Node_Id := Left_Opnd (N);
7666 R : constant Node_Id := Right_Opnd (N);
7667 T : Entity_Id := Find_Unique_Type (L, R);
7669 procedure Check_If_Expression (Cond : Node_Id);
7670 -- The resolution rule for if expressions requires that each such must
7671 -- have a unique type. This means that if several dependent expressions
7672 -- are of a non-null anonymous access type, and the context does not
7673 -- impose an expected type (as can be the case in an equality operation)
7674 -- the expression must be rejected.
7676 procedure Explain_Redundancy (N : Node_Id);
7677 -- Attempt to explain the nature of a redundant comparison with True. If
7678 -- the expression N is too complex, this routine issues a general error
7681 function Find_Unique_Access_Type return Entity_Id;
7682 -- In the case of allocators and access attributes, the context must
7683 -- provide an indication of the specific access type to be used. If
7684 -- one operand is of such a "generic" access type, check whether there
7685 -- is a specific visible access type that has the same designated type.
7686 -- This is semantically dubious, and of no interest to any real code,
7687 -- but c48008a makes it all worthwhile.
7689 -------------------------
7690 -- Check_If_Expression --
7691 -------------------------
7693 procedure Check_If_Expression (Cond : Node_Id) is
7694 Then_Expr : Node_Id;
7695 Else_Expr : Node_Id;
7698 if Nkind (Cond) = N_If_Expression then
7699 Then_Expr := Next (First (Expressions (Cond)));
7700 Else_Expr := Next (Then_Expr);
7702 if Nkind (Then_Expr) /= N_Null
7703 and then Nkind (Else_Expr) /= N_Null
7705 Error_Msg_N ("cannot determine type of if expression", Cond);
7708 end Check_If_Expression;
7710 ------------------------
7711 -- Explain_Redundancy --
7712 ------------------------
7714 procedure Explain_Redundancy (N : Node_Id) is
7722 -- Strip the operand down to an entity
7725 if Nkind (Val) = N_Selected_Component then
7726 Val := Selector_Name (Val);
7732 -- The construct denotes an entity
7734 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7735 Val_Id := Entity (Val);
7737 -- Do not generate an error message when the comparison is done
7738 -- against the enumeration literal Standard.True.
7740 if Ekind (Val_Id) /= E_Enumeration_Literal then
7742 -- Build a customized error message
7745 Add_Str_To_Name_Buffer ("?r?");
7747 if Ekind (Val_Id) = E_Component then
7748 Add_Str_To_Name_Buffer ("component ");
7750 elsif Ekind (Val_Id) = E_Constant then
7751 Add_Str_To_Name_Buffer ("constant ");
7753 elsif Ekind (Val_Id) = E_Discriminant then
7754 Add_Str_To_Name_Buffer ("discriminant ");
7756 elsif Is_Formal (Val_Id) then
7757 Add_Str_To_Name_Buffer ("parameter ");
7759 elsif Ekind (Val_Id) = E_Variable then
7760 Add_Str_To_Name_Buffer ("variable ");
7763 Add_Str_To_Name_Buffer ("& is always True!");
7766 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7769 -- The construct is too complex to disect, issue a general message
7772 Error_Msg_N ("?r?expression is always True!", Val);
7774 end Explain_Redundancy;
7776 -----------------------------
7777 -- Find_Unique_Access_Type --
7778 -----------------------------
7780 function Find_Unique_Access_Type return Entity_Id is
7786 if Ekind_In (Etype (R), E_Allocator_Type,
7787 E_Access_Attribute_Type)
7789 Acc := Designated_Type (Etype (R));
7791 elsif Ekind_In (Etype (L), E_Allocator_Type,
7792 E_Access_Attribute_Type)
7794 Acc := Designated_Type (Etype (L));
7800 while S /= Standard_Standard loop
7801 E := First_Entity (S);
7802 while Present (E) loop
7804 and then Is_Access_Type (E)
7805 and then Ekind (E) /= E_Allocator_Type
7806 and then Designated_Type (E) = Base_Type (Acc)
7818 end Find_Unique_Access_Type;
7820 -- Start of processing for Resolve_Equality_Op
7823 Set_Etype (N, Base_Type (Typ));
7824 Generate_Reference (T, N, ' ');
7826 if T = Any_Fixed then
7827 T := Unique_Fixed_Point_Type (L);
7830 if T /= Any_Type then
7831 if T = Any_String or else
7832 T = Any_Composite or else
7835 if T = Any_Character then
7836 Ambiguous_Character (L);
7838 Error_Msg_N ("ambiguous operands for equality", N);
7841 Set_Etype (N, Any_Type);
7844 elsif T = Any_Access
7845 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7847 T := Find_Unique_Access_Type;
7850 Error_Msg_N ("ambiguous operands for equality", N);
7851 Set_Etype (N, Any_Type);
7855 -- If expressions must have a single type, and if the context does
7856 -- not impose one the dependent expressions cannot be anonymous
7859 -- Why no similar processing for case expressions???
7861 elsif Ada_Version >= Ada_2012
7862 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7863 E_Anonymous_Access_Subprogram_Type)
7864 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7865 E_Anonymous_Access_Subprogram_Type)
7867 Check_If_Expression (L);
7868 Check_If_Expression (R);
7874 -- In SPARK, equality operators = and /= for array types other than
7875 -- String are only defined when, for each index position, the
7876 -- operands have equal static bounds.
7878 if Is_Array_Type (T) then
7880 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7881 -- operation if not needed.
7883 if Restriction_Check_Required (SPARK_05)
7884 and then Base_Type (T) /= Standard_String
7885 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7886 and then Etype (L) /= Any_Composite -- or else L in error
7887 and then Etype (R) /= Any_Composite -- or else R in error
7888 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7890 Check_SPARK_05_Restriction
7891 ("array types should have matching static bounds", N);
7895 -- If the unique type is a class-wide type then it will be expanded
7896 -- into a dispatching call to the predefined primitive. Therefore we
7897 -- check here for potential violation of such restriction.
7899 if Is_Class_Wide_Type (T) then
7900 Check_Restriction (No_Dispatching_Calls, N);
7903 if Warn_On_Redundant_Constructs
7904 and then Comes_From_Source (N)
7905 and then Comes_From_Source (R)
7906 and then Is_Entity_Name (R)
7907 and then Entity (R) = Standard_True
7909 Error_Msg_N -- CODEFIX
7910 ("?r?comparison with True is redundant!", N);
7911 Explain_Redundancy (Original_Node (R));
7914 Check_Unset_Reference (L);
7915 Check_Unset_Reference (R);
7916 Generate_Operator_Reference (N, T);
7917 Check_Low_Bound_Tested (N);
7919 -- If this is an inequality, it may be the implicit inequality
7920 -- created for a user-defined operation, in which case the corres-
7921 -- ponding equality operation is not intrinsic, and the operation
7922 -- cannot be constant-folded. Else fold.
7924 if Nkind (N) = N_Op_Eq
7925 or else Comes_From_Source (Entity (N))
7926 or else Ekind (Entity (N)) = E_Operator
7927 or else Is_Intrinsic_Subprogram
7928 (Corresponding_Equality (Entity (N)))
7930 Analyze_Dimension (N);
7931 Eval_Relational_Op (N);
7933 elsif Nkind (N) = N_Op_Ne
7934 and then Is_Abstract_Subprogram (Entity (N))
7936 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7939 -- Ada 2005: If one operand is an anonymous access type, convert the
7940 -- other operand to it, to ensure that the underlying types match in
7941 -- the back-end. Same for access_to_subprogram, and the conversion
7942 -- verifies that the types are subtype conformant.
7944 -- We apply the same conversion in the case one of the operands is a
7945 -- private subtype of the type of the other.
7947 -- Why the Expander_Active test here ???
7951 (Ekind_In (T, E_Anonymous_Access_Type,
7952 E_Anonymous_Access_Subprogram_Type)
7953 or else Is_Private_Type (T))
7955 if Etype (L) /= T then
7957 Make_Unchecked_Type_Conversion (Sloc (L),
7958 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7959 Expression => Relocate_Node (L)));
7960 Analyze_And_Resolve (L, T);
7963 if (Etype (R)) /= T then
7965 Make_Unchecked_Type_Conversion (Sloc (R),
7966 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7967 Expression => Relocate_Node (R)));
7968 Analyze_And_Resolve (R, T);
7972 end Resolve_Equality_Op;
7974 ----------------------------------
7975 -- Resolve_Explicit_Dereference --
7976 ----------------------------------
7978 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7979 Loc : constant Source_Ptr := Sloc (N);
7981 P : constant Node_Id := Prefix (N);
7984 -- The candidate prefix type, if overloaded
7990 Check_Fully_Declared_Prefix (Typ, P);
7993 -- A useful optimization: check whether the dereference denotes an
7994 -- element of a container, and if so rewrite it as a call to the
7995 -- corresponding Element function.
7997 -- Disabled for now, on advice of ARG. A more restricted form of the
7998 -- predicate might be acceptable ???
8000 -- if Is_Container_Element (N) then
8004 if Is_Overloaded (P) then
8006 -- Use the context type to select the prefix that has the correct
8007 -- designated type. Keep the first match, which will be the inner-
8010 Get_First_Interp (P, I, It);
8012 while Present (It.Typ) loop
8013 if Is_Access_Type (It.Typ)
8014 and then Covers (Typ, Designated_Type (It.Typ))
8020 -- Remove access types that do not match, but preserve access
8021 -- to subprogram interpretations, in case a further dereference
8022 -- is needed (see below).
8024 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8028 Get_Next_Interp (I, It);
8031 if Present (P_Typ) then
8033 Set_Etype (N, Designated_Type (P_Typ));
8036 -- If no interpretation covers the designated type of the prefix,
8037 -- this is the pathological case where not all implementations of
8038 -- the prefix allow the interpretation of the node as a call. Now
8039 -- that the expected type is known, Remove other interpretations
8040 -- from prefix, rewrite it as a call, and resolve again, so that
8041 -- the proper call node is generated.
8043 Get_First_Interp (P, I, It);
8044 while Present (It.Typ) loop
8045 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8049 Get_Next_Interp (I, It);
8053 Make_Function_Call (Loc,
8055 Make_Explicit_Dereference (Loc,
8057 Parameter_Associations => New_List);
8059 Save_Interps (N, New_N);
8061 Analyze_And_Resolve (N, Typ);
8065 -- If not overloaded, resolve P with its own type
8071 if Is_Access_Type (Etype (P)) then
8072 Apply_Access_Check (N);
8075 -- If the designated type is a packed unconstrained array type, and the
8076 -- explicit dereference is not in the context of an attribute reference,
8077 -- then we must compute and set the actual subtype, since it is needed
8078 -- by Gigi. The reason we exclude the attribute case is that this is
8079 -- handled fine by Gigi, and in fact we use such attributes to build the
8080 -- actual subtype. We also exclude generated code (which builds actual
8081 -- subtypes directly if they are needed).
8083 if Is_Array_Type (Etype (N))
8084 and then Is_Packed (Etype (N))
8085 and then not Is_Constrained (Etype (N))
8086 and then Nkind (Parent (N)) /= N_Attribute_Reference
8087 and then Comes_From_Source (N)
8089 Set_Etype (N, Get_Actual_Subtype (N));
8092 -- Note: No Eval processing is required for an explicit dereference,
8093 -- because such a name can never be static.
8095 end Resolve_Explicit_Dereference;
8097 -------------------------------------
8098 -- Resolve_Expression_With_Actions --
8099 -------------------------------------
8101 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8105 -- If N has no actions, and its expression has been constant folded,
8106 -- then rewrite N as just its expression. Note, we can't do this in
8107 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8108 -- Expression (N) to be expanded again.
8110 if Is_Empty_List (Actions (N))
8111 and then Compile_Time_Known_Value (Expression (N))
8113 Rewrite (N, Expression (N));
8115 end Resolve_Expression_With_Actions;
8117 ----------------------------------
8118 -- Resolve_Generalized_Indexing --
8119 ----------------------------------
8121 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8122 Indexing : constant Node_Id := Generalized_Indexing (N);
8128 -- In ASIS mode, propagate the information about the indices back to
8129 -- to the original indexing node. The generalized indexing is either
8130 -- a function call, or a dereference of one. The actuals include the
8131 -- prefix of the original node, which is the container expression.
8134 Resolve (Indexing, Typ);
8135 Set_Etype (N, Etype (Indexing));
8136 Set_Is_Overloaded (N, False);
8139 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8141 Call := Prefix (Call);
8144 if Nkind (Call) = N_Function_Call then
8145 Indices := Parameter_Associations (Call);
8146 Pref := Remove_Head (Indices);
8147 Set_Expressions (N, Indices);
8148 Set_Prefix (N, Pref);
8152 Rewrite (N, Indexing);
8155 end Resolve_Generalized_Indexing;
8157 ---------------------------
8158 -- Resolve_If_Expression --
8159 ---------------------------
8161 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8162 Condition : constant Node_Id := First (Expressions (N));
8163 Then_Expr : constant Node_Id := Next (Condition);
8164 Else_Expr : Node_Id := Next (Then_Expr);
8165 Else_Typ : Entity_Id;
8166 Then_Typ : Entity_Id;
8169 Resolve (Condition, Any_Boolean);
8170 Resolve (Then_Expr, Typ);
8171 Then_Typ := Etype (Then_Expr);
8173 -- When the "then" expression is of a scalar subtype different from the
8174 -- result subtype, then insert a conversion to ensure the generation of
8175 -- a constraint check. The same is done for the else part below, again
8176 -- comparing subtypes rather than base types.
8178 if Is_Scalar_Type (Then_Typ)
8179 and then Then_Typ /= Typ
8181 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8182 Analyze_And_Resolve (Then_Expr, Typ);
8185 -- If ELSE expression present, just resolve using the determined type
8187 if Present (Else_Expr) then
8188 Resolve (Else_Expr, Typ);
8189 Else_Typ := Etype (Else_Expr);
8191 if Is_Scalar_Type (Else_Typ)
8192 and then Else_Typ /= Typ
8194 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8195 Analyze_And_Resolve (Else_Expr, Typ);
8198 -- If no ELSE expression is present, root type must be Standard.Boolean
8199 -- and we provide a Standard.True result converted to the appropriate
8200 -- Boolean type (in case it is a derived boolean type).
8202 elsif Root_Type (Typ) = Standard_Boolean then
8204 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8205 Analyze_And_Resolve (Else_Expr, Typ);
8206 Append_To (Expressions (N), Else_Expr);
8209 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8210 Append_To (Expressions (N), Error);
8214 Eval_If_Expression (N);
8215 end Resolve_If_Expression;
8217 -------------------------------
8218 -- Resolve_Indexed_Component --
8219 -------------------------------
8221 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8222 Name : constant Node_Id := Prefix (N);
8224 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8228 if Present (Generalized_Indexing (N)) then
8229 Resolve_Generalized_Indexing (N, Typ);
8233 if Is_Overloaded (Name) then
8235 -- Use the context type to select the prefix that yields the correct
8241 I1 : Interp_Index := 0;
8242 P : constant Node_Id := Prefix (N);
8243 Found : Boolean := False;
8246 Get_First_Interp (P, I, It);
8247 while Present (It.Typ) loop
8248 if (Is_Array_Type (It.Typ)
8249 and then Covers (Typ, Component_Type (It.Typ)))
8250 or else (Is_Access_Type (It.Typ)
8251 and then Is_Array_Type (Designated_Type (It.Typ))
8255 Component_Type (Designated_Type (It.Typ))))
8258 It := Disambiguate (P, I1, I, Any_Type);
8260 if It = No_Interp then
8261 Error_Msg_N ("ambiguous prefix for indexing", N);
8267 Array_Type := It.Typ;
8273 Array_Type := It.Typ;
8278 Get_Next_Interp (I, It);
8283 Array_Type := Etype (Name);
8286 Resolve (Name, Array_Type);
8287 Array_Type := Get_Actual_Subtype_If_Available (Name);
8289 -- If prefix is access type, dereference to get real array type.
8290 -- Note: we do not apply an access check because the expander always
8291 -- introduces an explicit dereference, and the check will happen there.
8293 if Is_Access_Type (Array_Type) then
8294 Array_Type := Designated_Type (Array_Type);
8297 -- If name was overloaded, set component type correctly now
8298 -- If a misplaced call to an entry family (which has no index types)
8299 -- return. Error will be diagnosed from calling context.
8301 if Is_Array_Type (Array_Type) then
8302 Set_Etype (N, Component_Type (Array_Type));
8307 Index := First_Index (Array_Type);
8308 Expr := First (Expressions (N));
8310 -- The prefix may have resolved to a string literal, in which case its
8311 -- etype has a special representation. This is only possible currently
8312 -- if the prefix is a static concatenation, written in functional
8315 if Ekind (Array_Type) = E_String_Literal_Subtype then
8316 Resolve (Expr, Standard_Positive);
8319 while Present (Index) and Present (Expr) loop
8320 Resolve (Expr, Etype (Index));
8321 Check_Unset_Reference (Expr);
8323 if Is_Scalar_Type (Etype (Expr)) then
8324 Apply_Scalar_Range_Check (Expr, Etype (Index));
8326 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8334 Analyze_Dimension (N);
8336 -- Do not generate the warning on suspicious index if we are analyzing
8337 -- package Ada.Tags; otherwise we will report the warning with the
8338 -- Prims_Ptr field of the dispatch table.
8340 if Scope (Etype (Prefix (N))) = Standard_Standard
8342 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8345 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8346 Eval_Indexed_Component (N);
8349 -- If the array type is atomic, and the component is not atomic, then
8350 -- this is worth a warning, since we have a situation where the access
8351 -- to the component may cause extra read/writes of the atomic array
8352 -- object, or partial word accesses, which could be unexpected.
8354 if Nkind (N) = N_Indexed_Component
8355 and then Is_Atomic_Ref_With_Address (N)
8356 and then not (Has_Atomic_Components (Array_Type)
8357 or else (Is_Entity_Name (Prefix (N))
8358 and then Has_Atomic_Components
8359 (Entity (Prefix (N)))))
8360 and then not Is_Atomic (Component_Type (Array_Type))
8362 Error_Msg_N ("??access to non-atomic component of atomic array",
8364 Error_Msg_N ("??\may cause unexpected accesses to atomic object",
8367 end Resolve_Indexed_Component;
8369 -----------------------------
8370 -- Resolve_Integer_Literal --
8371 -----------------------------
8373 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8376 Eval_Integer_Literal (N);
8377 end Resolve_Integer_Literal;
8379 --------------------------------
8380 -- Resolve_Intrinsic_Operator --
8381 --------------------------------
8383 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8384 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8389 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8390 -- If the operand is a literal, it cannot be the expression in a
8391 -- conversion. Use a qualified expression instead.
8393 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8394 Loc : constant Source_Ptr := Sloc (Opnd);
8397 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8399 Make_Qualified_Expression (Loc,
8400 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8401 Expression => Relocate_Node (Opnd));
8405 Res := Unchecked_Convert_To (Btyp, Opnd);
8409 end Convert_Operand;
8411 -- Start of processing for Resolve_Intrinsic_Operator
8414 -- We must preserve the original entity in a generic setting, so that
8415 -- the legality of the operation can be verified in an instance.
8417 if not Expander_Active then
8422 while Scope (Op) /= Standard_Standard loop
8424 pragma Assert (Present (Op));
8428 Set_Is_Overloaded (N, False);
8430 -- If the result or operand types are private, rewrite with unchecked
8431 -- conversions on the operands and the result, to expose the proper
8432 -- underlying numeric type.
8434 if Is_Private_Type (Typ)
8435 or else Is_Private_Type (Etype (Left_Opnd (N)))
8436 or else Is_Private_Type (Etype (Right_Opnd (N)))
8438 Arg1 := Convert_Operand (Left_Opnd (N));
8439 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
8440 -- What on earth is this commented out fragment of code???
8442 if Nkind (N) = N_Op_Expon then
8443 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8445 Arg2 := Convert_Operand (Right_Opnd (N));
8448 if Nkind (Arg1) = N_Type_Conversion then
8449 Save_Interps (Left_Opnd (N), Expression (Arg1));
8452 if Nkind (Arg2) = N_Type_Conversion then
8453 Save_Interps (Right_Opnd (N), Expression (Arg2));
8456 Set_Left_Opnd (N, Arg1);
8457 Set_Right_Opnd (N, Arg2);
8459 Set_Etype (N, Btyp);
8460 Rewrite (N, Unchecked_Convert_To (Typ, N));
8463 elsif Typ /= Etype (Left_Opnd (N))
8464 or else Typ /= Etype (Right_Opnd (N))
8466 -- Add explicit conversion where needed, and save interpretations in
8467 -- case operands are overloaded.
8469 Arg1 := Convert_To (Typ, Left_Opnd (N));
8470 Arg2 := Convert_To (Typ, Right_Opnd (N));
8472 if Nkind (Arg1) = N_Type_Conversion then
8473 Save_Interps (Left_Opnd (N), Expression (Arg1));
8475 Save_Interps (Left_Opnd (N), Arg1);
8478 if Nkind (Arg2) = N_Type_Conversion then
8479 Save_Interps (Right_Opnd (N), Expression (Arg2));
8481 Save_Interps (Right_Opnd (N), Arg2);
8484 Rewrite (Left_Opnd (N), Arg1);
8485 Rewrite (Right_Opnd (N), Arg2);
8488 Resolve_Arithmetic_Op (N, Typ);
8491 Resolve_Arithmetic_Op (N, Typ);
8493 end Resolve_Intrinsic_Operator;
8495 --------------------------------------
8496 -- Resolve_Intrinsic_Unary_Operator --
8497 --------------------------------------
8499 procedure Resolve_Intrinsic_Unary_Operator
8503 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8509 while Scope (Op) /= Standard_Standard loop
8511 pragma Assert (Present (Op));
8516 if Is_Private_Type (Typ) then
8517 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8518 Save_Interps (Right_Opnd (N), Expression (Arg2));
8520 Set_Right_Opnd (N, Arg2);
8522 Set_Etype (N, Btyp);
8523 Rewrite (N, Unchecked_Convert_To (Typ, N));
8527 Resolve_Unary_Op (N, Typ);
8529 end Resolve_Intrinsic_Unary_Operator;
8531 ------------------------
8532 -- Resolve_Logical_Op --
8533 ------------------------
8535 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8539 Check_No_Direct_Boolean_Operators (N);
8541 -- Predefined operations on scalar types yield the base type. On the
8542 -- other hand, logical operations on arrays yield the type of the
8543 -- arguments (and the context).
8545 if Is_Array_Type (Typ) then
8548 B_Typ := Base_Type (Typ);
8551 -- The following test is required because the operands of the operation
8552 -- may be literals, in which case the resulting type appears to be
8553 -- compatible with a signed integer type, when in fact it is compatible
8554 -- only with modular types. If the context itself is universal, the
8555 -- operation is illegal.
8557 if not Valid_Boolean_Arg (Typ) then
8558 Error_Msg_N ("invalid context for logical operation", N);
8559 Set_Etype (N, Any_Type);
8562 elsif Typ = Any_Modular then
8564 ("no modular type available in this context", N);
8565 Set_Etype (N, Any_Type);
8568 elsif Is_Modular_Integer_Type (Typ)
8569 and then Etype (Left_Opnd (N)) = Universal_Integer
8570 and then Etype (Right_Opnd (N)) = Universal_Integer
8572 Check_For_Visible_Operator (N, B_Typ);
8575 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8576 -- is active and the result type is standard Boolean (do not mess with
8577 -- ops that return a nonstandard Boolean type, because something strange
8580 -- Note: you might expect this replacement to be done during expansion,
8581 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8582 -- is used, no part of the right operand of an "and" or "or" operator
8583 -- should be executed if the left operand would short-circuit the
8584 -- evaluation of the corresponding "and then" or "or else". If we left
8585 -- the replacement to expansion time, then run-time checks associated
8586 -- with such operands would be evaluated unconditionally, due to being
8587 -- before the condition prior to the rewriting as short-circuit forms
8588 -- during expansion.
8590 if Short_Circuit_And_Or
8591 and then B_Typ = Standard_Boolean
8592 and then Nkind_In (N, N_Op_And, N_Op_Or)
8594 if Nkind (N) = N_Op_And then
8596 Make_And_Then (Sloc (N),
8597 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8598 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8599 Analyze_And_Resolve (N, B_Typ);
8601 -- Case of OR changed to OR ELSE
8605 Make_Or_Else (Sloc (N),
8606 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8607 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8608 Analyze_And_Resolve (N, B_Typ);
8611 -- Return now, since analysis of the rewritten ops will take care of
8612 -- other reference bookkeeping and expression folding.
8617 Resolve (Left_Opnd (N), B_Typ);
8618 Resolve (Right_Opnd (N), B_Typ);
8620 Check_Unset_Reference (Left_Opnd (N));
8621 Check_Unset_Reference (Right_Opnd (N));
8623 Set_Etype (N, B_Typ);
8624 Generate_Operator_Reference (N, B_Typ);
8625 Eval_Logical_Op (N);
8627 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8628 -- only when both operands have same static lower and higher bounds. Of
8629 -- course the types have to match, so only check if operands are
8630 -- compatible and the node itself has no errors.
8632 if Is_Array_Type (B_Typ)
8633 and then Nkind (N) in N_Binary_Op
8636 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8637 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8640 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8641 -- operation if not needed.
8643 if Restriction_Check_Required (SPARK_05)
8644 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8645 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8646 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8647 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8649 Check_SPARK_05_Restriction
8650 ("array types should have matching static bounds", N);
8655 Check_Function_Writable_Actuals (N);
8656 end Resolve_Logical_Op;
8658 ---------------------------
8659 -- Resolve_Membership_Op --
8660 ---------------------------
8662 -- The context can only be a boolean type, and does not determine the
8663 -- arguments. Arguments should be unambiguous, but the preference rule for
8664 -- universal types applies.
8666 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8667 pragma Warnings (Off, Typ);
8669 L : constant Node_Id := Left_Opnd (N);
8670 R : constant Node_Id := Right_Opnd (N);
8673 procedure Resolve_Set_Membership;
8674 -- Analysis has determined a unique type for the left operand. Use it to
8675 -- resolve the disjuncts.
8677 ----------------------------
8678 -- Resolve_Set_Membership --
8679 ----------------------------
8681 procedure Resolve_Set_Membership is
8683 Ltyp : constant Entity_Id := Etype (L);
8688 Alt := First (Alternatives (N));
8689 while Present (Alt) loop
8691 -- Alternative is an expression, a range
8692 -- or a subtype mark.
8694 if not Is_Entity_Name (Alt)
8695 or else not Is_Type (Entity (Alt))
8697 Resolve (Alt, Ltyp);
8703 -- Check for duplicates for discrete case
8705 if Is_Discrete_Type (Ltyp) then
8712 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8716 -- Loop checking duplicates. This is quadratic, but giant sets
8717 -- are unlikely in this context so it's a reasonable choice.
8720 Alt := First (Alternatives (N));
8721 while Present (Alt) loop
8722 if Is_OK_Static_Expression (Alt)
8723 and then (Nkind_In (Alt, N_Integer_Literal,
8724 N_Character_Literal)
8725 or else Nkind (Alt) in N_Has_Entity)
8728 Alts (Nalts) := (Alt, Expr_Value (Alt));
8730 for J in 1 .. Nalts - 1 loop
8731 if Alts (J).Val = Alts (Nalts).Val then
8732 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8733 Error_Msg_N ("duplicate of value given#??", Alt);
8742 end Resolve_Set_Membership;
8744 -- Start of processing for Resolve_Membership_Op
8747 if L = Error or else R = Error then
8751 if Present (Alternatives (N)) then
8752 Resolve_Set_Membership;
8755 elsif not Is_Overloaded (R)
8757 (Etype (R) = Universal_Integer
8759 Etype (R) = Universal_Real)
8760 and then Is_Overloaded (L)
8764 -- Ada 2005 (AI-251): Support the following case:
8766 -- type I is interface;
8767 -- type T is tagged ...
8769 -- function Test (O : I'Class) is
8771 -- return O in T'Class.
8774 -- In this case we have nothing else to do. The membership test will be
8775 -- done at run time.
8777 elsif Ada_Version >= Ada_2005
8778 and then Is_Class_Wide_Type (Etype (L))
8779 and then Is_Interface (Etype (L))
8780 and then Is_Class_Wide_Type (Etype (R))
8781 and then not Is_Interface (Etype (R))
8785 T := Intersect_Types (L, R);
8788 -- If mixed-mode operations are present and operands are all literal,
8789 -- the only interpretation involves Duration, which is probably not
8790 -- the intention of the programmer.
8792 if T = Any_Fixed then
8793 T := Unique_Fixed_Point_Type (N);
8795 if T = Any_Type then
8801 Check_Unset_Reference (L);
8803 if Nkind (R) = N_Range
8804 and then not Is_Scalar_Type (T)
8806 Error_Msg_N ("scalar type required for range", R);
8809 if Is_Entity_Name (R) then
8810 Freeze_Expression (R);
8813 Check_Unset_Reference (R);
8816 -- Here after resolving membership operation
8820 Eval_Membership_Op (N);
8821 Check_Function_Writable_Actuals (N);
8822 end Resolve_Membership_Op;
8828 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8829 Loc : constant Source_Ptr := Sloc (N);
8832 -- Handle restriction against anonymous null access values This
8833 -- restriction can be turned off using -gnatdj.
8835 -- Ada 2005 (AI-231): Remove restriction
8837 if Ada_Version < Ada_2005
8838 and then not Debug_Flag_J
8839 and then Ekind (Typ) = E_Anonymous_Access_Type
8840 and then Comes_From_Source (N)
8842 -- In the common case of a call which uses an explicitly null value
8843 -- for an access parameter, give specialized error message.
8845 if Nkind (Parent (N)) in N_Subprogram_Call then
8847 ("null is not allowed as argument for an access parameter", N);
8849 -- Standard message for all other cases (are there any?)
8853 ("null cannot be of an anonymous access type", N);
8857 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8858 -- assignment to a null-excluding object
8860 if Ada_Version >= Ada_2005
8861 and then Can_Never_Be_Null (Typ)
8862 and then Nkind (Parent (N)) = N_Assignment_Statement
8864 if not Inside_Init_Proc then
8866 (Compile_Time_Constraint_Error (N,
8867 "(Ada 2005) null not allowed in null-excluding objects??"),
8868 Make_Raise_Constraint_Error (Loc,
8869 Reason => CE_Access_Check_Failed));
8872 Make_Raise_Constraint_Error (Loc,
8873 Reason => CE_Access_Check_Failed));
8877 -- In a distributed context, null for a remote access to subprogram may
8878 -- need to be replaced with a special record aggregate. In this case,
8879 -- return after having done the transformation.
8881 if (Ekind (Typ) = E_Record_Type
8882 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8883 and then Remote_AST_Null_Value (N, Typ)
8888 -- The null literal takes its type from the context
8893 -----------------------
8894 -- Resolve_Op_Concat --
8895 -----------------------
8897 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8899 -- We wish to avoid deep recursion, because concatenations are often
8900 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8901 -- operands nonrecursively until we find something that is not a simple
8902 -- concatenation (A in this case). We resolve that, and then walk back
8903 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8904 -- to do the rest of the work at each level. The Parent pointers allow
8905 -- us to avoid recursion, and thus avoid running out of memory. See also
8906 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8912 -- The following code is equivalent to:
8914 -- Resolve_Op_Concat_First (NN, Typ);
8915 -- Resolve_Op_Concat_Arg (N, ...);
8916 -- Resolve_Op_Concat_Rest (N, Typ);
8918 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8919 -- operand is a concatenation.
8921 -- Walk down left operands
8924 Resolve_Op_Concat_First (NN, Typ);
8925 Op1 := Left_Opnd (NN);
8926 exit when not (Nkind (Op1) = N_Op_Concat
8927 and then not Is_Array_Type (Component_Type (Typ))
8928 and then Entity (Op1) = Entity (NN));
8932 -- Now (given the above example) NN is A&B and Op1 is A
8934 -- First resolve Op1 ...
8936 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8938 -- ... then walk NN back up until we reach N (where we started), calling
8939 -- Resolve_Op_Concat_Rest along the way.
8942 Resolve_Op_Concat_Rest (NN, Typ);
8947 if Base_Type (Etype (N)) /= Standard_String then
8948 Check_SPARK_05_Restriction
8949 ("result of concatenation should have type String", N);
8951 end Resolve_Op_Concat;
8953 ---------------------------
8954 -- Resolve_Op_Concat_Arg --
8955 ---------------------------
8957 procedure Resolve_Op_Concat_Arg
8963 Btyp : constant Entity_Id := Base_Type (Typ);
8964 Ctyp : constant Entity_Id := Component_Type (Typ);
8969 or else (not Is_Overloaded (Arg)
8970 and then Etype (Arg) /= Any_Composite
8971 and then Covers (Ctyp, Etype (Arg)))
8973 Resolve (Arg, Ctyp);
8975 Resolve (Arg, Btyp);
8978 -- If both Array & Array and Array & Component are visible, there is a
8979 -- potential ambiguity that must be reported.
8981 elsif Has_Compatible_Type (Arg, Ctyp) then
8982 if Nkind (Arg) = N_Aggregate
8983 and then Is_Composite_Type (Ctyp)
8985 if Is_Private_Type (Ctyp) then
8986 Resolve (Arg, Btyp);
8988 -- If the operation is user-defined and not overloaded use its
8989 -- profile. The operation may be a renaming, in which case it has
8990 -- been rewritten, and we want the original profile.
8992 elsif not Is_Overloaded (N)
8993 and then Comes_From_Source (Entity (Original_Node (N)))
8994 and then Ekind (Entity (Original_Node (N))) = E_Function
8998 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9001 -- Otherwise an aggregate may match both the array type and the
9005 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9006 Set_Etype (Arg, Any_Type);
9010 if Is_Overloaded (Arg)
9011 and then Has_Compatible_Type (Arg, Typ)
9012 and then Etype (Arg) /= Any_Type
9020 Get_First_Interp (Arg, I, It);
9022 Get_Next_Interp (I, It);
9024 -- Special-case the error message when the overloading is
9025 -- caused by a function that yields an array and can be
9026 -- called without parameters.
9028 if It.Nam = Func then
9029 Error_Msg_Sloc := Sloc (Func);
9030 Error_Msg_N ("ambiguous call to function#", Arg);
9032 ("\\interpretation as call yields&", Arg, Typ);
9034 ("\\interpretation as indexing of call yields&",
9035 Arg, Component_Type (Typ));
9038 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9040 Get_First_Interp (Arg, I, It);
9041 while Present (It.Nam) loop
9042 Error_Msg_Sloc := Sloc (It.Nam);
9044 if Base_Type (It.Typ) = Btyp
9046 Base_Type (It.Typ) = Base_Type (Ctyp)
9048 Error_Msg_N -- CODEFIX
9049 ("\\possible interpretation#", Arg);
9052 Get_Next_Interp (I, It);
9058 Resolve (Arg, Component_Type (Typ));
9060 if Nkind (Arg) = N_String_Literal then
9061 Set_Etype (Arg, Component_Type (Typ));
9064 if Arg = Left_Opnd (N) then
9065 Set_Is_Component_Left_Opnd (N);
9067 Set_Is_Component_Right_Opnd (N);
9072 Resolve (Arg, Btyp);
9075 -- Concatenation is restricted in SPARK: each operand must be either a
9076 -- string literal, the name of a string constant, a static character or
9077 -- string expression, or another concatenation. Arg cannot be a
9078 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9079 -- separately on each final operand, past concatenation operations.
9081 if Is_Character_Type (Etype (Arg)) then
9082 if not Is_OK_Static_Expression (Arg) then
9083 Check_SPARK_05_Restriction
9084 ("character operand for concatenation should be static", Arg);
9087 elsif Is_String_Type (Etype (Arg)) then
9088 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9089 and then Is_Constant_Object (Entity (Arg)))
9090 and then not Is_OK_Static_Expression (Arg)
9092 Check_SPARK_05_Restriction
9093 ("string operand for concatenation should be static", Arg);
9096 -- Do not issue error on an operand that is neither a character nor a
9097 -- string, as the error is issued in Resolve_Op_Concat.
9103 Check_Unset_Reference (Arg);
9104 end Resolve_Op_Concat_Arg;
9106 -----------------------------
9107 -- Resolve_Op_Concat_First --
9108 -----------------------------
9110 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9111 Btyp : constant Entity_Id := Base_Type (Typ);
9112 Op1 : constant Node_Id := Left_Opnd (N);
9113 Op2 : constant Node_Id := Right_Opnd (N);
9116 -- The parser folds an enormous sequence of concatenations of string
9117 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9118 -- in the right operand. If the expression resolves to a predefined "&"
9119 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9120 -- we give an error. See P_Simple_Expression in Par.Ch4.
9122 if Nkind (Op2) = N_String_Literal
9123 and then Is_Folded_In_Parser (Op2)
9124 and then Ekind (Entity (N)) = E_Function
9126 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9127 and then String_Length (Strval (Op1)) = 0);
9128 Error_Msg_N ("too many user-defined concatenations", N);
9132 Set_Etype (N, Btyp);
9134 if Is_Limited_Composite (Btyp) then
9135 Error_Msg_N ("concatenation not available for limited array", N);
9136 Explain_Limited_Type (Btyp, N);
9138 end Resolve_Op_Concat_First;
9140 ----------------------------
9141 -- Resolve_Op_Concat_Rest --
9142 ----------------------------
9144 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9145 Op1 : constant Node_Id := Left_Opnd (N);
9146 Op2 : constant Node_Id := Right_Opnd (N);
9149 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9151 Generate_Operator_Reference (N, Typ);
9153 if Is_String_Type (Typ) then
9154 Eval_Concatenation (N);
9157 -- If this is not a static concatenation, but the result is a string
9158 -- type (and not an array of strings) ensure that static string operands
9159 -- have their subtypes properly constructed.
9161 if Nkind (N) /= N_String_Literal
9162 and then Is_Character_Type (Component_Type (Typ))
9164 Set_String_Literal_Subtype (Op1, Typ);
9165 Set_String_Literal_Subtype (Op2, Typ);
9167 end Resolve_Op_Concat_Rest;
9169 ----------------------
9170 -- Resolve_Op_Expon --
9171 ----------------------
9173 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9174 B_Typ : constant Entity_Id := Base_Type (Typ);
9177 -- Catch attempts to do fixed-point exponentiation with universal
9178 -- operands, which is a case where the illegality is not caught during
9179 -- normal operator analysis. This is not done in preanalysis mode
9180 -- since the tree is not fully decorated during preanalysis.
9182 if Full_Analysis then
9183 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9184 Error_Msg_N ("exponentiation not available for fixed point", N);
9187 elsif Nkind (Parent (N)) in N_Op
9188 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9189 and then Etype (N) = Universal_Real
9190 and then Comes_From_Source (N)
9192 Error_Msg_N ("exponentiation not available for fixed point", N);
9197 if Comes_From_Source (N)
9198 and then Ekind (Entity (N)) = E_Function
9199 and then Is_Imported (Entity (N))
9200 and then Is_Intrinsic_Subprogram (Entity (N))
9202 Resolve_Intrinsic_Operator (N, Typ);
9206 if Etype (Left_Opnd (N)) = Universal_Integer
9207 or else Etype (Left_Opnd (N)) = Universal_Real
9209 Check_For_Visible_Operator (N, B_Typ);
9212 -- We do the resolution using the base type, because intermediate values
9213 -- in expressions are always of the base type, not a subtype of it.
9215 Resolve (Left_Opnd (N), B_Typ);
9216 Resolve (Right_Opnd (N), Standard_Integer);
9218 -- For integer types, right argument must be in Natural range
9220 if Is_Integer_Type (Typ) then
9221 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9224 Check_Unset_Reference (Left_Opnd (N));
9225 Check_Unset_Reference (Right_Opnd (N));
9227 Set_Etype (N, B_Typ);
9228 Generate_Operator_Reference (N, B_Typ);
9230 Analyze_Dimension (N);
9232 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9233 -- Evaluate the exponentiation operator for dimensioned type
9235 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9240 -- Set overflow checking bit. Much cleverer code needed here eventually
9241 -- and perhaps the Resolve routines should be separated for the various
9242 -- arithmetic operations, since they will need different processing. ???
9244 if Nkind (N) in N_Op then
9245 if not Overflow_Checks_Suppressed (Etype (N)) then
9246 Enable_Overflow_Check (N);
9249 end Resolve_Op_Expon;
9251 --------------------
9252 -- Resolve_Op_Not --
9253 --------------------
9255 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9258 function Parent_Is_Boolean return Boolean;
9259 -- This function determines if the parent node is a boolean operator or
9260 -- operation (comparison op, membership test, or short circuit form) and
9261 -- the not in question is the left operand of this operation. Note that
9262 -- if the not is in parens, then false is returned.
9264 -----------------------
9265 -- Parent_Is_Boolean --
9266 -----------------------
9268 function Parent_Is_Boolean return Boolean is
9270 if Paren_Count (N) /= 0 then
9274 case Nkind (Parent (N)) is
9289 return Left_Opnd (Parent (N)) = N;
9295 end Parent_Is_Boolean;
9297 -- Start of processing for Resolve_Op_Not
9300 -- Predefined operations on scalar types yield the base type. On the
9301 -- other hand, logical operations on arrays yield the type of the
9302 -- arguments (and the context).
9304 if Is_Array_Type (Typ) then
9307 B_Typ := Base_Type (Typ);
9310 -- Straightforward case of incorrect arguments
9312 if not Valid_Boolean_Arg (Typ) then
9313 Error_Msg_N ("invalid operand type for operator&", N);
9314 Set_Etype (N, Any_Type);
9317 -- Special case of probable missing parens
9319 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9320 if Parent_Is_Boolean then
9322 ("operand of not must be enclosed in parentheses",
9326 ("no modular type available in this context", N);
9329 Set_Etype (N, Any_Type);
9332 -- OK resolution of NOT
9335 -- Warn if non-boolean types involved. This is a case like not a < b
9336 -- where a and b are modular, where we will get (not a) < b and most
9337 -- likely not (a < b) was intended.
9339 if Warn_On_Questionable_Missing_Parens
9340 and then not Is_Boolean_Type (Typ)
9341 and then Parent_Is_Boolean
9343 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9346 -- Warn on double negation if checking redundant constructs
9348 if Warn_On_Redundant_Constructs
9349 and then Comes_From_Source (N)
9350 and then Comes_From_Source (Right_Opnd (N))
9351 and then Root_Type (Typ) = Standard_Boolean
9352 and then Nkind (Right_Opnd (N)) = N_Op_Not
9354 Error_Msg_N ("redundant double negation?r?", N);
9357 -- Complete resolution and evaluation of NOT
9359 Resolve (Right_Opnd (N), B_Typ);
9360 Check_Unset_Reference (Right_Opnd (N));
9361 Set_Etype (N, B_Typ);
9362 Generate_Operator_Reference (N, B_Typ);
9367 -----------------------------
9368 -- Resolve_Operator_Symbol --
9369 -----------------------------
9371 -- Nothing to be done, all resolved already
9373 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9374 pragma Warnings (Off, N);
9375 pragma Warnings (Off, Typ);
9379 end Resolve_Operator_Symbol;
9381 ----------------------------------
9382 -- Resolve_Qualified_Expression --
9383 ----------------------------------
9385 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9386 pragma Warnings (Off, Typ);
9388 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9389 Expr : constant Node_Id := Expression (N);
9392 Resolve (Expr, Target_Typ);
9394 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9395 -- operation if not needed.
9397 if Restriction_Check_Required (SPARK_05)
9398 and then Is_Array_Type (Target_Typ)
9399 and then Is_Array_Type (Etype (Expr))
9400 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9401 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9403 Check_SPARK_05_Restriction
9404 ("array types should have matching static bounds", N);
9407 -- A qualified expression requires an exact match of the type, class-
9408 -- wide matching is not allowed. However, if the qualifying type is
9409 -- specific and the expression has a class-wide type, it may still be
9410 -- okay, since it can be the result of the expansion of a call to a
9411 -- dispatching function, so we also have to check class-wideness of the
9412 -- type of the expression's original node.
9414 if (Is_Class_Wide_Type (Target_Typ)
9416 (Is_Class_Wide_Type (Etype (Expr))
9417 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9418 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9420 Wrong_Type (Expr, Target_Typ);
9423 -- If the target type is unconstrained, then we reset the type of the
9424 -- result from the type of the expression. For other cases, the actual
9425 -- subtype of the expression is the target type.
9427 if Is_Composite_Type (Target_Typ)
9428 and then not Is_Constrained (Target_Typ)
9430 Set_Etype (N, Etype (Expr));
9433 Analyze_Dimension (N);
9434 Eval_Qualified_Expression (N);
9436 -- If we still have a qualified expression after the static evaluation,
9437 -- then apply a scalar range check if needed. The reason that we do this
9438 -- after the Eval call is that otherwise, the application of the range
9439 -- check may convert an illegal static expression and result in warning
9440 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9442 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9443 Apply_Scalar_Range_Check (Expr, Typ);
9445 end Resolve_Qualified_Expression;
9447 ------------------------------
9448 -- Resolve_Raise_Expression --
9449 ------------------------------
9451 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9453 if Typ = Raise_Type then
9454 Error_Msg_N ("cannot find unique type for raise expression", N);
9455 Set_Etype (N, Any_Type);
9459 end Resolve_Raise_Expression;
9465 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9466 L : constant Node_Id := Low_Bound (N);
9467 H : constant Node_Id := High_Bound (N);
9469 function First_Last_Ref return Boolean;
9470 -- Returns True if N is of the form X'First .. X'Last where X is the
9471 -- same entity for both attributes.
9473 --------------------
9474 -- First_Last_Ref --
9475 --------------------
9477 function First_Last_Ref return Boolean is
9478 Lorig : constant Node_Id := Original_Node (L);
9479 Horig : constant Node_Id := Original_Node (H);
9482 if Nkind (Lorig) = N_Attribute_Reference
9483 and then Nkind (Horig) = N_Attribute_Reference
9484 and then Attribute_Name (Lorig) = Name_First
9485 and then Attribute_Name (Horig) = Name_Last
9488 PL : constant Node_Id := Prefix (Lorig);
9489 PH : constant Node_Id := Prefix (Horig);
9491 if Is_Entity_Name (PL)
9492 and then Is_Entity_Name (PH)
9493 and then Entity (PL) = Entity (PH)
9503 -- Start of processing for Resolve_Range
9510 -- Check for inappropriate range on unordered enumeration type
9512 if Bad_Unordered_Enumeration_Reference (N, Typ)
9514 -- Exclude X'First .. X'Last if X is the same entity for both
9516 and then not First_Last_Ref
9518 Error_Msg_Sloc := Sloc (Typ);
9520 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9523 Check_Unset_Reference (L);
9524 Check_Unset_Reference (H);
9526 -- We have to check the bounds for being within the base range as
9527 -- required for a non-static context. Normally this is automatic and
9528 -- done as part of evaluating expressions, but the N_Range node is an
9529 -- exception, since in GNAT we consider this node to be a subexpression,
9530 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9531 -- this, but that would put the test on the main evaluation path for
9534 Check_Non_Static_Context (L);
9535 Check_Non_Static_Context (H);
9537 -- Check for an ambiguous range over character literals. This will
9538 -- happen with a membership test involving only literals.
9540 if Typ = Any_Character then
9541 Ambiguous_Character (L);
9542 Set_Etype (N, Any_Type);
9546 -- If bounds are static, constant-fold them, so size computations are
9547 -- identical between front-end and back-end. Do not perform this
9548 -- transformation while analyzing generic units, as type information
9549 -- would be lost when reanalyzing the constant node in the instance.
9551 if Is_Discrete_Type (Typ) and then Expander_Active then
9552 if Is_OK_Static_Expression (L) then
9553 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9556 if Is_OK_Static_Expression (H) then
9557 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9562 --------------------------
9563 -- Resolve_Real_Literal --
9564 --------------------------
9566 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9567 Actual_Typ : constant Entity_Id := Etype (N);
9570 -- Special processing for fixed-point literals to make sure that the
9571 -- value is an exact multiple of small where this is required. We skip
9572 -- this for the universal real case, and also for generic types.
9574 if Is_Fixed_Point_Type (Typ)
9575 and then Typ /= Universal_Fixed
9576 and then Typ /= Any_Fixed
9577 and then not Is_Generic_Type (Typ)
9580 Val : constant Ureal := Realval (N);
9581 Cintr : constant Ureal := Val / Small_Value (Typ);
9582 Cint : constant Uint := UR_Trunc (Cintr);
9583 Den : constant Uint := Norm_Den (Cintr);
9587 -- Case of literal is not an exact multiple of the Small
9591 -- For a source program literal for a decimal fixed-point type,
9592 -- this is statically illegal (RM 4.9(36)).
9594 if Is_Decimal_Fixed_Point_Type (Typ)
9595 and then Actual_Typ = Universal_Real
9596 and then Comes_From_Source (N)
9598 Error_Msg_N ("value has extraneous low order digits", N);
9601 -- Generate a warning if literal from source
9603 if Is_OK_Static_Expression (N)
9604 and then Warn_On_Bad_Fixed_Value
9607 ("?b?static fixed-point value is not a multiple of Small!",
9611 -- Replace literal by a value that is the exact representation
9612 -- of a value of the type, i.e. a multiple of the small value,
9613 -- by truncation, since Machine_Rounds is false for all GNAT
9614 -- fixed-point types (RM 4.9(38)).
9616 Stat := Is_OK_Static_Expression (N);
9618 Make_Real_Literal (Sloc (N),
9619 Realval => Small_Value (Typ) * Cint));
9621 Set_Is_Static_Expression (N, Stat);
9624 -- In all cases, set the corresponding integer field
9626 Set_Corresponding_Integer_Value (N, Cint);
9630 -- Now replace the actual type by the expected type as usual
9633 Eval_Real_Literal (N);
9634 end Resolve_Real_Literal;
9636 -----------------------
9637 -- Resolve_Reference --
9638 -----------------------
9640 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9641 P : constant Node_Id := Prefix (N);
9644 -- Replace general access with specific type
9646 if Ekind (Etype (N)) = E_Allocator_Type then
9647 Set_Etype (N, Base_Type (Typ));
9650 Resolve (P, Designated_Type (Etype (N)));
9652 -- If we are taking the reference of a volatile entity, then treat it as
9653 -- a potential modification of this entity. This is too conservative,
9654 -- but necessary because remove side effects can cause transformations
9655 -- of normal assignments into reference sequences that otherwise fail to
9656 -- notice the modification.
9658 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9659 Note_Possible_Modification (P, Sure => False);
9661 end Resolve_Reference;
9663 --------------------------------
9664 -- Resolve_Selected_Component --
9665 --------------------------------
9667 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9669 Comp1 : Entity_Id := Empty; -- prevent junk warning
9670 P : constant Node_Id := Prefix (N);
9671 S : constant Node_Id := Selector_Name (N);
9672 T : Entity_Id := Etype (P);
9674 I1 : Interp_Index := 0; -- prevent junk warning
9679 function Init_Component return Boolean;
9680 -- Check whether this is the initialization of a component within an
9681 -- init proc (by assignment or call to another init proc). If true,
9682 -- there is no need for a discriminant check.
9684 --------------------
9685 -- Init_Component --
9686 --------------------
9688 function Init_Component return Boolean is
9690 return Inside_Init_Proc
9691 and then Nkind (Prefix (N)) = N_Identifier
9692 and then Chars (Prefix (N)) = Name_uInit
9693 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9696 -- Start of processing for Resolve_Selected_Component
9699 if Is_Overloaded (P) then
9701 -- Use the context type to select the prefix that has a selector
9702 -- of the correct name and type.
9705 Get_First_Interp (P, I, It);
9707 Search : while Present (It.Typ) loop
9708 if Is_Access_Type (It.Typ) then
9709 T := Designated_Type (It.Typ);
9714 -- Locate selected component. For a private prefix the selector
9715 -- can denote a discriminant.
9717 if Is_Record_Type (T) or else Is_Private_Type (T) then
9719 -- The visible components of a class-wide type are those of
9722 if Is_Class_Wide_Type (T) then
9726 Comp := First_Entity (T);
9727 while Present (Comp) loop
9728 if Chars (Comp) = Chars (S)
9729 and then Covers (Typ, Etype (Comp))
9738 It := Disambiguate (P, I1, I, Any_Type);
9740 if It = No_Interp then
9742 ("ambiguous prefix for selected component", N);
9749 -- There may be an implicit dereference. Retrieve
9750 -- designated record type.
9752 if Is_Access_Type (It1.Typ) then
9753 T := Designated_Type (It1.Typ);
9758 if Scope (Comp1) /= T then
9760 -- Resolution chooses the new interpretation.
9761 -- Find the component with the right name.
9763 Comp1 := First_Entity (T);
9764 while Present (Comp1)
9765 and then Chars (Comp1) /= Chars (S)
9767 Comp1 := Next_Entity (Comp1);
9776 Comp := Next_Entity (Comp);
9780 Get_Next_Interp (I, It);
9783 -- There must be a legal interpretation at this point
9785 pragma Assert (Found);
9786 Resolve (P, It1.Typ);
9788 Set_Entity_With_Checks (S, Comp1);
9791 -- Resolve prefix with its type
9796 -- Generate cross-reference. We needed to wait until full overloading
9797 -- resolution was complete to do this, since otherwise we can't tell if
9798 -- we are an lvalue or not.
9800 if May_Be_Lvalue (N) then
9801 Generate_Reference (Entity (S), S, 'm');
9803 Generate_Reference (Entity (S), S, 'r');
9806 -- If prefix is an access type, the node will be transformed into an
9807 -- explicit dereference during expansion. The type of the node is the
9808 -- designated type of that of the prefix.
9810 if Is_Access_Type (Etype (P)) then
9811 T := Designated_Type (Etype (P));
9812 Check_Fully_Declared_Prefix (T, P);
9817 -- Set flag for expander if discriminant check required
9819 if Has_Discriminants (T)
9820 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
9821 and then Present (Original_Record_Component (Entity (S)))
9822 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9823 and then not Discriminant_Checks_Suppressed (T)
9824 and then not Init_Component
9826 Set_Do_Discriminant_Check (N);
9829 if Ekind (Entity (S)) = E_Void then
9830 Error_Msg_N ("premature use of component", S);
9833 -- If the prefix is a record conversion, this may be a renamed
9834 -- discriminant whose bounds differ from those of the original
9835 -- one, so we must ensure that a range check is performed.
9837 if Nkind (P) = N_Type_Conversion
9838 and then Ekind (Entity (S)) = E_Discriminant
9839 and then Is_Discrete_Type (Typ)
9841 Set_Etype (N, Base_Type (Typ));
9844 -- Note: No Eval processing is required, because the prefix is of a
9845 -- record type, or protected type, and neither can possibly be static.
9847 -- If the record type is atomic, and the component is non-atomic, then
9848 -- this is worth a warning, since we have a situation where the access
9849 -- to the component may cause extra read/writes of the atomic array
9850 -- object, or partial word accesses, both of which may be unexpected.
9852 if Nkind (N) = N_Selected_Component
9853 and then Is_Atomic_Ref_With_Address (N)
9854 and then not Is_Atomic (Entity (S))
9855 and then not Is_Atomic (Etype (Entity (S)))
9858 ("??access to non-atomic component of atomic record",
9861 ("\??may cause unexpected accesses to atomic object",
9865 Analyze_Dimension (N);
9866 end Resolve_Selected_Component;
9872 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9873 B_Typ : constant Entity_Id := Base_Type (Typ);
9874 L : constant Node_Id := Left_Opnd (N);
9875 R : constant Node_Id := Right_Opnd (N);
9878 -- We do the resolution using the base type, because intermediate values
9879 -- in expressions always are of the base type, not a subtype of it.
9882 Resolve (R, Standard_Natural);
9884 Check_Unset_Reference (L);
9885 Check_Unset_Reference (R);
9887 Set_Etype (N, B_Typ);
9888 Generate_Operator_Reference (N, B_Typ);
9892 ---------------------------
9893 -- Resolve_Short_Circuit --
9894 ---------------------------
9896 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9897 B_Typ : constant Entity_Id := Base_Type (Typ);
9898 L : constant Node_Id := Left_Opnd (N);
9899 R : constant Node_Id := Right_Opnd (N);
9902 -- Ensure all actions associated with the left operand (e.g.
9903 -- finalization of transient controlled objects) are fully evaluated
9904 -- locally within an expression with actions. This is particularly
9905 -- helpful for coverage analysis. However this should not happen in
9908 if Expander_Active then
9910 Reloc_L : constant Node_Id := Relocate_Node (L);
9912 Save_Interps (Old_N => L, New_N => Reloc_L);
9915 Make_Expression_With_Actions (Sloc (L),
9916 Actions => New_List,
9917 Expression => Reloc_L));
9919 -- Set Comes_From_Source on L to preserve warnings for unset
9922 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9929 -- Check for issuing warning for always False assert/check, this happens
9930 -- when assertions are turned off, in which case the pragma Assert/Check
9931 -- was transformed into:
9933 -- if False and then <condition> then ...
9935 -- and we detect this pattern
9937 if Warn_On_Assertion_Failure
9938 and then Is_Entity_Name (R)
9939 and then Entity (R) = Standard_False
9940 and then Nkind (Parent (N)) = N_If_Statement
9941 and then Nkind (N) = N_And_Then
9942 and then Is_Entity_Name (L)
9943 and then Entity (L) = Standard_False
9946 Orig : constant Node_Id := Original_Node (Parent (N));
9949 -- Special handling of Asssert pragma
9951 if Nkind (Orig) = N_Pragma
9952 and then Pragma_Name (Orig) = Name_Assert
9955 Expr : constant Node_Id :=
9958 (First (Pragma_Argument_Associations (Orig))));
9961 -- Don't warn if original condition is explicit False,
9962 -- since obviously the failure is expected in this case.
9964 if Is_Entity_Name (Expr)
9965 and then Entity (Expr) = Standard_False
9969 -- Issue warning. We do not want the deletion of the
9970 -- IF/AND-THEN to take this message with it. We achieve this
9971 -- by making sure that the expanded code points to the Sloc
9972 -- of the expression, not the original pragma.
9975 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
9976 -- The source location of the expression is not usually
9977 -- the best choice here. For example, it gets located on
9978 -- the last AND keyword in a chain of boolean expressiond
9979 -- AND'ed together. It is best to put the message on the
9980 -- first character of the assertion, which is the effect
9981 -- of the First_Node call here.
9984 ("?A?assertion would fail at run time!",
9986 (First (Pragma_Argument_Associations (Orig))));
9990 -- Similar processing for Check pragma
9992 elsif Nkind (Orig) = N_Pragma
9993 and then Pragma_Name (Orig) = Name_Check
9995 -- Don't want to warn if original condition is explicit False
9998 Expr : constant Node_Id :=
10001 (Next (First (Pragma_Argument_Associations (Orig)))));
10003 if Is_Entity_Name (Expr)
10004 and then Entity (Expr) = Standard_False
10011 -- Again use Error_Msg_F rather than Error_Msg_N, see
10012 -- comment above for an explanation of why we do this.
10015 ("?A?check would fail at run time!",
10017 (Last (Pragma_Argument_Associations (Orig))));
10024 -- Continue with processing of short circuit
10026 Check_Unset_Reference (L);
10027 Check_Unset_Reference (R);
10029 Set_Etype (N, B_Typ);
10030 Eval_Short_Circuit (N);
10031 end Resolve_Short_Circuit;
10033 -------------------
10034 -- Resolve_Slice --
10035 -------------------
10037 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10038 Drange : constant Node_Id := Discrete_Range (N);
10039 Name : constant Node_Id := Prefix (N);
10040 Array_Type : Entity_Id := Empty;
10041 Dexpr : Node_Id := Empty;
10042 Index_Type : Entity_Id;
10045 if Is_Overloaded (Name) then
10047 -- Use the context type to select the prefix that yields the correct
10052 I1 : Interp_Index := 0;
10054 P : constant Node_Id := Prefix (N);
10055 Found : Boolean := False;
10058 Get_First_Interp (P, I, It);
10059 while Present (It.Typ) loop
10060 if (Is_Array_Type (It.Typ)
10061 and then Covers (Typ, It.Typ))
10062 or else (Is_Access_Type (It.Typ)
10063 and then Is_Array_Type (Designated_Type (It.Typ))
10064 and then Covers (Typ, Designated_Type (It.Typ)))
10067 It := Disambiguate (P, I1, I, Any_Type);
10069 if It = No_Interp then
10070 Error_Msg_N ("ambiguous prefix for slicing", N);
10071 Set_Etype (N, Typ);
10075 Array_Type := It.Typ;
10080 Array_Type := It.Typ;
10085 Get_Next_Interp (I, It);
10090 Array_Type := Etype (Name);
10093 Resolve (Name, Array_Type);
10095 if Is_Access_Type (Array_Type) then
10096 Apply_Access_Check (N);
10097 Array_Type := Designated_Type (Array_Type);
10099 -- If the prefix is an access to an unconstrained array, we must use
10100 -- the actual subtype of the object to perform the index checks. The
10101 -- object denoted by the prefix is implicit in the node, so we build
10102 -- an explicit representation for it in order to compute the actual
10105 if not Is_Constrained (Array_Type) then
10106 Remove_Side_Effects (Prefix (N));
10109 Obj : constant Node_Id :=
10110 Make_Explicit_Dereference (Sloc (N),
10111 Prefix => New_Copy_Tree (Prefix (N)));
10113 Set_Etype (Obj, Array_Type);
10114 Set_Parent (Obj, Parent (N));
10115 Array_Type := Get_Actual_Subtype (Obj);
10119 elsif Is_Entity_Name (Name)
10120 or else Nkind (Name) = N_Explicit_Dereference
10121 or else (Nkind (Name) = N_Function_Call
10122 and then not Is_Constrained (Etype (Name)))
10124 Array_Type := Get_Actual_Subtype (Name);
10126 -- If the name is a selected component that depends on discriminants,
10127 -- build an actual subtype for it. This can happen only when the name
10128 -- itself is overloaded; otherwise the actual subtype is created when
10129 -- the selected component is analyzed.
10131 elsif Nkind (Name) = N_Selected_Component
10132 and then Full_Analysis
10133 and then Depends_On_Discriminant (First_Index (Array_Type))
10136 Act_Decl : constant Node_Id :=
10137 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10139 Insert_Action (N, Act_Decl);
10140 Array_Type := Defining_Identifier (Act_Decl);
10143 -- Maybe this should just be "else", instead of checking for the
10144 -- specific case of slice??? This is needed for the case where the
10145 -- prefix is an Image attribute, which gets expanded to a slice, and so
10146 -- has a constrained subtype which we want to use for the slice range
10147 -- check applied below (the range check won't get done if the
10148 -- unconstrained subtype of the 'Image is used).
10150 elsif Nkind (Name) = N_Slice then
10151 Array_Type := Etype (Name);
10154 -- Obtain the type of the array index
10156 if Ekind (Array_Type) = E_String_Literal_Subtype then
10157 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10159 Index_Type := Etype (First_Index (Array_Type));
10162 -- If name was overloaded, set slice type correctly now
10164 Set_Etype (N, Array_Type);
10166 -- Handle the generation of a range check that compares the array index
10167 -- against the discrete_range. The check is not applied to internally
10168 -- built nodes associated with the expansion of dispatch tables. Check
10169 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10172 if Tagged_Type_Expansion
10173 and then RTU_Loaded (Ada_Tags)
10174 and then Nkind (Prefix (N)) = N_Selected_Component
10175 and then Present (Entity (Selector_Name (Prefix (N))))
10176 and then Entity (Selector_Name (Prefix (N))) =
10177 RTE_Record_Component (RE_Prims_Ptr)
10181 -- The discrete_range is specified by a subtype indication. Create a
10182 -- shallow copy and inherit the type, parent and source location from
10183 -- the discrete_range. This ensures that the range check is inserted
10184 -- relative to the slice and that the runtime exception points to the
10185 -- proper construct.
10187 elsif Is_Entity_Name (Drange) then
10188 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10190 Set_Etype (Dexpr, Etype (Drange));
10191 Set_Parent (Dexpr, Parent (Drange));
10192 Set_Sloc (Dexpr, Sloc (Drange));
10194 -- The discrete_range is a regular range. Resolve the bounds and remove
10195 -- their side effects.
10198 Resolve (Drange, Base_Type (Index_Type));
10200 if Nkind (Drange) = N_Range then
10201 Force_Evaluation (Low_Bound (Drange));
10202 Force_Evaluation (High_Bound (Drange));
10208 if Present (Dexpr) then
10209 Apply_Range_Check (Dexpr, Index_Type);
10212 Set_Slice_Subtype (N);
10214 -- Check bad use of type with predicates
10220 if Nkind (Drange) = N_Subtype_Indication
10221 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10223 Subt := Entity (Subtype_Mark (Drange));
10225 Subt := Etype (Drange);
10228 if Has_Predicates (Subt) then
10229 Bad_Predicated_Subtype_Use
10230 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10234 -- Otherwise here is where we check suspicious indexes
10236 if Nkind (Drange) = N_Range then
10237 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10238 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10241 Analyze_Dimension (N);
10245 ----------------------------
10246 -- Resolve_String_Literal --
10247 ----------------------------
10249 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10250 C_Typ : constant Entity_Id := Component_Type (Typ);
10251 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10252 Loc : constant Source_Ptr := Sloc (N);
10253 Str : constant String_Id := Strval (N);
10254 Strlen : constant Nat := String_Length (Str);
10255 Subtype_Id : Entity_Id;
10256 Need_Check : Boolean;
10259 -- For a string appearing in a concatenation, defer creation of the
10260 -- string_literal_subtype until the end of the resolution of the
10261 -- concatenation, because the literal may be constant-folded away. This
10262 -- is a useful optimization for long concatenation expressions.
10264 -- If the string is an aggregate built for a single character (which
10265 -- happens in a non-static context) or a is null string to which special
10266 -- checks may apply, we build the subtype. Wide strings must also get a
10267 -- string subtype if they come from a one character aggregate. Strings
10268 -- generated by attributes might be static, but it is often hard to
10269 -- determine whether the enclosing context is static, so we generate
10270 -- subtypes for them as well, thus losing some rarer optimizations ???
10271 -- Same for strings that come from a static conversion.
10274 (Strlen = 0 and then Typ /= Standard_String)
10275 or else Nkind (Parent (N)) /= N_Op_Concat
10276 or else (N /= Left_Opnd (Parent (N))
10277 and then N /= Right_Opnd (Parent (N)))
10278 or else ((Typ = Standard_Wide_String
10279 or else Typ = Standard_Wide_Wide_String)
10280 and then Nkind (Original_Node (N)) /= N_String_Literal);
10282 -- If the resolving type is itself a string literal subtype, we can just
10283 -- reuse it, since there is no point in creating another.
10285 if Ekind (Typ) = E_String_Literal_Subtype then
10288 elsif Nkind (Parent (N)) = N_Op_Concat
10289 and then not Need_Check
10290 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10291 N_Attribute_Reference,
10292 N_Qualified_Expression,
10297 -- Do not generate a string literal subtype for the default expression
10298 -- of a formal parameter in GNATprove mode. This is because the string
10299 -- subtype is associated with the freezing actions of the subprogram,
10300 -- however freezing is disabled in GNATprove mode and as a result the
10301 -- subtype is unavailable.
10303 elsif GNATprove_Mode
10304 and then Nkind (Parent (N)) = N_Parameter_Specification
10308 -- Otherwise we must create a string literal subtype. Note that the
10309 -- whole idea of string literal subtypes is simply to avoid the need
10310 -- for building a full fledged array subtype for each literal.
10313 Set_String_Literal_Subtype (N, Typ);
10314 Subtype_Id := Etype (N);
10317 if Nkind (Parent (N)) /= N_Op_Concat
10320 Set_Etype (N, Subtype_Id);
10321 Eval_String_Literal (N);
10324 if Is_Limited_Composite (Typ)
10325 or else Is_Private_Composite (Typ)
10327 Error_Msg_N ("string literal not available for private array", N);
10328 Set_Etype (N, Any_Type);
10332 -- The validity of a null string has been checked in the call to
10333 -- Eval_String_Literal.
10338 -- Always accept string literal with component type Any_Character, which
10339 -- occurs in error situations and in comparisons of literals, both of
10340 -- which should accept all literals.
10342 elsif R_Typ = Any_Character then
10345 -- If the type is bit-packed, then we always transform the string
10346 -- literal into a full fledged aggregate.
10348 elsif Is_Bit_Packed_Array (Typ) then
10351 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10354 -- For Standard.Wide_Wide_String, or any other type whose component
10355 -- type is Standard.Wide_Wide_Character, we know that all the
10356 -- characters in the string must be acceptable, since the parser
10357 -- accepted the characters as valid character literals.
10359 if R_Typ = Standard_Wide_Wide_Character then
10362 -- For the case of Standard.String, or any other type whose component
10363 -- type is Standard.Character, we must make sure that there are no
10364 -- wide characters in the string, i.e. that it is entirely composed
10365 -- of characters in range of type Character.
10367 -- If the string literal is the result of a static concatenation, the
10368 -- test has already been performed on the components, and need not be
10371 elsif R_Typ = Standard_Character
10372 and then Nkind (Original_Node (N)) /= N_Op_Concat
10374 for J in 1 .. Strlen loop
10375 if not In_Character_Range (Get_String_Char (Str, J)) then
10377 -- If we are out of range, post error. This is one of the
10378 -- very few places that we place the flag in the middle of
10379 -- a token, right under the offending wide character. Not
10380 -- quite clear if this is right wrt wide character encoding
10381 -- sequences, but it's only an error message.
10384 ("literal out of range of type Standard.Character",
10385 Source_Ptr (Int (Loc) + J));
10390 -- For the case of Standard.Wide_String, or any other type whose
10391 -- component type is Standard.Wide_Character, we must make sure that
10392 -- there are no wide characters in the string, i.e. that it is
10393 -- entirely composed of characters in range of type Wide_Character.
10395 -- If the string literal is the result of a static concatenation,
10396 -- the test has already been performed on the components, and need
10397 -- not be repeated.
10399 elsif R_Typ = Standard_Wide_Character
10400 and then Nkind (Original_Node (N)) /= N_Op_Concat
10402 for J in 1 .. Strlen loop
10403 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10405 -- If we are out of range, post error. This is one of the
10406 -- very few places that we place the flag in the middle of
10407 -- a token, right under the offending wide character.
10409 -- This is not quite right, because characters in general
10410 -- will take more than one character position ???
10413 ("literal out of range of type Standard.Wide_Character",
10414 Source_Ptr (Int (Loc) + J));
10419 -- If the root type is not a standard character, then we will convert
10420 -- the string into an aggregate and will let the aggregate code do
10421 -- the checking. Standard Wide_Wide_Character is also OK here.
10427 -- See if the component type of the array corresponding to the string
10428 -- has compile time known bounds. If yes we can directly check
10429 -- whether the evaluation of the string will raise constraint error.
10430 -- Otherwise we need to transform the string literal into the
10431 -- corresponding character aggregate and let the aggregate code do
10434 if Is_Standard_Character_Type (R_Typ) then
10436 -- Check for the case of full range, where we are definitely OK
10438 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10442 -- Here the range is not the complete base type range, so check
10445 Comp_Typ_Lo : constant Node_Id :=
10446 Type_Low_Bound (Component_Type (Typ));
10447 Comp_Typ_Hi : constant Node_Id :=
10448 Type_High_Bound (Component_Type (Typ));
10453 if Compile_Time_Known_Value (Comp_Typ_Lo)
10454 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10456 for J in 1 .. Strlen loop
10457 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10459 if Char_Val < Expr_Value (Comp_Typ_Lo)
10460 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10462 Apply_Compile_Time_Constraint_Error
10463 (N, "character out of range??",
10464 CE_Range_Check_Failed,
10465 Loc => Source_Ptr (Int (Loc) + J));
10475 -- If we got here we meed to transform the string literal into the
10476 -- equivalent qualified positional array aggregate. This is rather
10477 -- heavy artillery for this situation, but it is hard work to avoid.
10480 Lits : constant List_Id := New_List;
10481 P : Source_Ptr := Loc + 1;
10485 -- Build the character literals, we give them source locations that
10486 -- correspond to the string positions, which is a bit tricky given
10487 -- the possible presence of wide character escape sequences.
10489 for J in 1 .. Strlen loop
10490 C := Get_String_Char (Str, J);
10491 Set_Character_Literal_Name (C);
10494 Make_Character_Literal (P,
10495 Chars => Name_Find,
10496 Char_Literal_Value => UI_From_CC (C)));
10498 if In_Character_Range (C) then
10501 -- Should we have a call to Skip_Wide here ???
10510 Make_Qualified_Expression (Loc,
10511 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10513 Make_Aggregate (Loc, Expressions => Lits)));
10515 Analyze_And_Resolve (N, Typ);
10517 end Resolve_String_Literal;
10519 -----------------------------
10520 -- Resolve_Type_Conversion --
10521 -----------------------------
10523 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10524 Conv_OK : constant Boolean := Conversion_OK (N);
10525 Operand : constant Node_Id := Expression (N);
10526 Operand_Typ : constant Entity_Id := Etype (Operand);
10527 Target_Typ : constant Entity_Id := Etype (N);
10532 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10533 -- Set to False to suppress cases where we want to suppress the test
10534 -- for redundancy to avoid possible false positives on this warning.
10538 and then not Valid_Conversion (N, Target_Typ, Operand)
10543 -- If the Operand Etype is Universal_Fixed, then the conversion is
10544 -- never redundant. We need this check because by the time we have
10545 -- finished the rather complex transformation, the conversion looks
10546 -- redundant when it is not.
10548 if Operand_Typ = Universal_Fixed then
10549 Test_Redundant := False;
10551 -- If the operand is marked as Any_Fixed, then special processing is
10552 -- required. This is also a case where we suppress the test for a
10553 -- redundant conversion, since most certainly it is not redundant.
10555 elsif Operand_Typ = Any_Fixed then
10556 Test_Redundant := False;
10558 -- Mixed-mode operation involving a literal. Context must be a fixed
10559 -- type which is applied to the literal subsequently.
10561 if Is_Fixed_Point_Type (Typ) then
10562 Set_Etype (Operand, Universal_Real);
10564 elsif Is_Numeric_Type (Typ)
10565 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10566 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10568 Etype (Left_Opnd (Operand)) = Universal_Real)
10570 -- Return if expression is ambiguous
10572 if Unique_Fixed_Point_Type (N) = Any_Type then
10575 -- If nothing else, the available fixed type is Duration
10578 Set_Etype (Operand, Standard_Duration);
10581 -- Resolve the real operand with largest available precision
10583 if Etype (Right_Opnd (Operand)) = Universal_Real then
10584 Rop := New_Copy_Tree (Right_Opnd (Operand));
10586 Rop := New_Copy_Tree (Left_Opnd (Operand));
10589 Resolve (Rop, Universal_Real);
10591 -- If the operand is a literal (it could be a non-static and
10592 -- illegal exponentiation) check whether the use of Duration
10593 -- is potentially inaccurate.
10595 if Nkind (Rop) = N_Real_Literal
10596 and then Realval (Rop) /= Ureal_0
10597 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10600 ("??universal real operand can only "
10601 & "be interpreted as Duration!", Rop);
10603 ("\??precision will be lost in the conversion!", Rop);
10606 elsif Is_Numeric_Type (Typ)
10607 and then Nkind (Operand) in N_Op
10608 and then Unique_Fixed_Point_Type (N) /= Any_Type
10610 Set_Etype (Operand, Standard_Duration);
10613 Error_Msg_N ("invalid context for mixed mode operation", N);
10614 Set_Etype (Operand, Any_Type);
10621 -- In SPARK, a type conversion between array types should be restricted
10622 -- to types which have matching static bounds.
10624 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10625 -- operation if not needed.
10627 if Restriction_Check_Required (SPARK_05)
10628 and then Is_Array_Type (Target_Typ)
10629 and then Is_Array_Type (Operand_Typ)
10630 and then Operand_Typ /= Any_Composite -- or else Operand in error
10631 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10633 Check_SPARK_05_Restriction
10634 ("array types should have matching static bounds", N);
10637 -- In formal mode, the operand of an ancestor type conversion must be an
10638 -- object (not an expression).
10640 if Is_Tagged_Type (Target_Typ)
10641 and then not Is_Class_Wide_Type (Target_Typ)
10642 and then Is_Tagged_Type (Operand_Typ)
10643 and then not Is_Class_Wide_Type (Operand_Typ)
10644 and then Is_Ancestor (Target_Typ, Operand_Typ)
10645 and then not Is_SPARK_05_Object_Reference (Operand)
10647 Check_SPARK_05_Restriction ("object required", Operand);
10650 Analyze_Dimension (N);
10652 -- Note: we do the Eval_Type_Conversion call before applying the
10653 -- required checks for a subtype conversion. This is important, since
10654 -- both are prepared under certain circumstances to change the type
10655 -- conversion to a constraint error node, but in the case of
10656 -- Eval_Type_Conversion this may reflect an illegality in the static
10657 -- case, and we would miss the illegality (getting only a warning
10658 -- message), if we applied the type conversion checks first.
10660 Eval_Type_Conversion (N);
10662 -- Even when evaluation is not possible, we may be able to simplify the
10663 -- conversion or its expression. This needs to be done before applying
10664 -- checks, since otherwise the checks may use the original expression
10665 -- and defeat the simplifications. This is specifically the case for
10666 -- elimination of the floating-point Truncation attribute in
10667 -- float-to-int conversions.
10669 Simplify_Type_Conversion (N);
10671 -- If after evaluation we still have a type conversion, then we may need
10672 -- to apply checks required for a subtype conversion.
10674 -- Skip these type conversion checks if universal fixed operands
10675 -- operands involved, since range checks are handled separately for
10676 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10678 if Nkind (N) = N_Type_Conversion
10679 and then not Is_Generic_Type (Root_Type (Target_Typ))
10680 and then Target_Typ /= Universal_Fixed
10681 and then Operand_Typ /= Universal_Fixed
10683 Apply_Type_Conversion_Checks (N);
10686 -- Issue warning for conversion of simple object to its own type. We
10687 -- have to test the original nodes, since they may have been rewritten
10688 -- by various optimizations.
10690 Orig_N := Original_Node (N);
10692 -- Here we test for a redundant conversion if the warning mode is
10693 -- active (and was not locally reset), and we have a type conversion
10694 -- from source not appearing in a generic instance.
10697 and then Nkind (Orig_N) = N_Type_Conversion
10698 and then Comes_From_Source (Orig_N)
10699 and then not In_Instance
10701 Orig_N := Original_Node (Expression (Orig_N));
10702 Orig_T := Target_Typ;
10704 -- If the node is part of a larger expression, the Target_Type
10705 -- may not be the original type of the node if the context is a
10706 -- condition. Recover original type to see if conversion is needed.
10708 if Is_Boolean_Type (Orig_T)
10709 and then Nkind (Parent (N)) in N_Op
10711 Orig_T := Etype (Parent (N));
10714 -- If we have an entity name, then give the warning if the entity
10715 -- is the right type, or if it is a loop parameter covered by the
10716 -- original type (that's needed because loop parameters have an
10717 -- odd subtype coming from the bounds).
10719 if (Is_Entity_Name (Orig_N)
10721 (Etype (Entity (Orig_N)) = Orig_T
10723 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10724 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10726 -- If not an entity, then type of expression must match
10728 or else Etype (Orig_N) = Orig_T
10730 -- One more check, do not give warning if the analyzed conversion
10731 -- has an expression with non-static bounds, and the bounds of the
10732 -- target are static. This avoids junk warnings in cases where the
10733 -- conversion is necessary to establish staticness, for example in
10734 -- a case statement.
10736 if not Is_OK_Static_Subtype (Operand_Typ)
10737 and then Is_OK_Static_Subtype (Target_Typ)
10741 -- Finally, if this type conversion occurs in a context requiring
10742 -- a prefix, and the expression is a qualified expression then the
10743 -- type conversion is not redundant, since a qualified expression
10744 -- is not a prefix, whereas a type conversion is. For example, "X
10745 -- := T'(Funx(...)).Y;" is illegal because a selected component
10746 -- requires a prefix, but a type conversion makes it legal: "X :=
10747 -- T(T'(Funx(...))).Y;"
10749 -- In Ada 2012, a qualified expression is a name, so this idiom is
10750 -- no longer needed, but we still suppress the warning because it
10751 -- seems unfriendly for warnings to pop up when you switch to the
10752 -- newer language version.
10754 elsif Nkind (Orig_N) = N_Qualified_Expression
10755 and then Nkind_In (Parent (N), N_Attribute_Reference,
10756 N_Indexed_Component,
10757 N_Selected_Component,
10759 N_Explicit_Dereference)
10763 -- Never warn on conversion to Long_Long_Integer'Base since
10764 -- that is most likely an artifact of the extended overflow
10765 -- checking and comes from complex expanded code.
10767 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10770 -- Here we give the redundant conversion warning. If it is an
10771 -- entity, give the name of the entity in the message. If not,
10772 -- just mention the expression.
10774 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10777 if Is_Entity_Name (Orig_N) then
10778 Error_Msg_Node_2 := Orig_T;
10779 Error_Msg_NE -- CODEFIX
10780 ("??redundant conversion, & is of type &!",
10781 N, Entity (Orig_N));
10784 ("??redundant conversion, expression is of type&!",
10791 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10792 -- No need to perform any interface conversion if the type of the
10793 -- expression coincides with the target type.
10795 if Ada_Version >= Ada_2005
10796 and then Expander_Active
10797 and then Operand_Typ /= Target_Typ
10800 Opnd : Entity_Id := Operand_Typ;
10801 Target : Entity_Id := Target_Typ;
10804 -- If the type of the operand is a limited view, use the non-
10805 -- limited view when available.
10807 if From_Limited_With (Opnd)
10808 and then Ekind (Opnd) in Incomplete_Kind
10809 and then Present (Non_Limited_View (Opnd))
10811 Opnd := Non_Limited_View (Opnd);
10812 Set_Etype (Expression (N), Opnd);
10815 if Is_Access_Type (Opnd) then
10816 Opnd := Designated_Type (Opnd);
10819 if Is_Access_Type (Target_Typ) then
10820 Target := Designated_Type (Target);
10823 if Opnd = Target then
10826 -- Conversion from interface type
10828 elsif Is_Interface (Opnd) then
10830 -- Ada 2005 (AI-217): Handle entities from limited views
10832 if From_Limited_With (Opnd) then
10833 Error_Msg_Qual_Level := 99;
10834 Error_Msg_NE -- CODEFIX
10835 ("missing WITH clause on package &", N,
10836 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10838 ("type conversions require visibility of the full view",
10841 elsif From_Limited_With (Target)
10843 (Is_Access_Type (Target_Typ)
10844 and then Present (Non_Limited_View (Etype (Target))))
10846 Error_Msg_Qual_Level := 99;
10847 Error_Msg_NE -- CODEFIX
10848 ("missing WITH clause on package &", N,
10849 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10851 ("type conversions require visibility of the full view",
10855 Expand_Interface_Conversion (N);
10858 -- Conversion to interface type
10860 elsif Is_Interface (Target) then
10864 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10865 Opnd := Etype (Opnd);
10868 if Is_Class_Wide_Type (Opnd)
10869 or else Interface_Present_In_Ancestor
10873 Expand_Interface_Conversion (N);
10875 Error_Msg_Name_1 := Chars (Etype (Target));
10876 Error_Msg_Name_2 := Chars (Opnd);
10878 ("wrong interface conversion (% is not a progenitor "
10885 -- Ada 2012: if target type has predicates, the result requires a
10886 -- predicate check. If the context is a call to another predicate
10887 -- check we must prevent infinite recursion.
10889 if Has_Predicates (Target_Typ) then
10890 if Nkind (Parent (N)) = N_Function_Call
10891 and then Present (Name (Parent (N)))
10892 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10894 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10899 Apply_Predicate_Check (N, Target_Typ);
10903 -- If at this stage we have a real to integer conversion, make sure
10904 -- that the Do_Range_Check flag is set, because such conversions in
10905 -- general need a range check. We only need this if expansion is off
10906 -- or we are in GNATProve mode.
10908 if Nkind (N) = N_Type_Conversion
10909 and then (GNATprove_Mode or not Expander_Active)
10910 and then Is_Integer_Type (Target_Typ)
10911 and then Is_Real_Type (Operand_Typ)
10913 Set_Do_Range_Check (Operand);
10915 end Resolve_Type_Conversion;
10917 ----------------------
10918 -- Resolve_Unary_Op --
10919 ----------------------
10921 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
10922 B_Typ : constant Entity_Id := Base_Type (Typ);
10923 R : constant Node_Id := Right_Opnd (N);
10929 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
10930 Error_Msg_Name_1 := Chars (Typ);
10931 Check_SPARK_05_Restriction
10932 ("unary operator not defined for modular type%", N);
10935 -- Deal with intrinsic unary operators
10937 if Comes_From_Source (N)
10938 and then Ekind (Entity (N)) = E_Function
10939 and then Is_Imported (Entity (N))
10940 and then Is_Intrinsic_Subprogram (Entity (N))
10942 Resolve_Intrinsic_Unary_Operator (N, Typ);
10946 -- Deal with universal cases
10948 if Etype (R) = Universal_Integer
10950 Etype (R) = Universal_Real
10952 Check_For_Visible_Operator (N, B_Typ);
10955 Set_Etype (N, B_Typ);
10956 Resolve (R, B_Typ);
10958 -- Generate warning for expressions like abs (x mod 2)
10960 if Warn_On_Redundant_Constructs
10961 and then Nkind (N) = N_Op_Abs
10963 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
10965 if OK and then Hi >= Lo and then Lo >= 0 then
10966 Error_Msg_N -- CODEFIX
10967 ("?r?abs applied to known non-negative value has no effect", N);
10971 -- Deal with reference generation
10973 Check_Unset_Reference (R);
10974 Generate_Operator_Reference (N, B_Typ);
10975 Analyze_Dimension (N);
10978 -- Set overflow checking bit. Much cleverer code needed here eventually
10979 -- and perhaps the Resolve routines should be separated for the various
10980 -- arithmetic operations, since they will need different processing ???
10982 if Nkind (N) in N_Op then
10983 if not Overflow_Checks_Suppressed (Etype (N)) then
10984 Enable_Overflow_Check (N);
10988 -- Generate warning for expressions like -5 mod 3 for integers. No need
10989 -- to worry in the floating-point case, since parens do not affect the
10990 -- result so there is no point in giving in a warning.
10993 Norig : constant Node_Id := Original_Node (N);
11002 if Warn_On_Questionable_Missing_Parens
11003 and then Comes_From_Source (Norig)
11004 and then Is_Integer_Type (Typ)
11005 and then Nkind (Norig) = N_Op_Minus
11007 Rorig := Original_Node (Right_Opnd (Norig));
11009 -- We are looking for cases where the right operand is not
11010 -- parenthesized, and is a binary operator, multiply, divide, or
11011 -- mod. These are the cases where the grouping can affect results.
11013 if Paren_Count (Rorig) = 0
11014 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11016 -- For mod, we always give the warning, since the value is
11017 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11018 -- -(5 mod 315)). But for the other cases, the only concern is
11019 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11020 -- overflows, but (-2) * 64 does not). So we try to give the
11021 -- message only when overflow is possible.
11023 if Nkind (Rorig) /= N_Op_Mod
11024 and then Compile_Time_Known_Value (R)
11026 Val := Expr_Value (R);
11028 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11029 HB := Expr_Value (Type_High_Bound (Typ));
11031 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11034 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11035 LB := Expr_Value (Type_Low_Bound (Typ));
11037 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11040 -- Note that the test below is deliberately excluding the
11041 -- largest negative number, since that is a potentially
11042 -- troublesome case (e.g. -2 * x, where the result is the
11043 -- largest negative integer has an overflow with 2 * x).
11045 if Val > LB and then Val <= HB then
11050 -- For the multiplication case, the only case we have to worry
11051 -- about is when (-a)*b is exactly the largest negative number
11052 -- so that -(a*b) can cause overflow. This can only happen if
11053 -- a is a power of 2, and more generally if any operand is a
11054 -- constant that is not a power of 2, then the parentheses
11055 -- cannot affect whether overflow occurs. We only bother to
11056 -- test the left most operand
11058 -- Loop looking at left operands for one that has known value
11061 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11062 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11063 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11065 -- Operand value of 0 or 1 skips warning
11070 -- Otherwise check power of 2, if power of 2, warn, if
11071 -- anything else, skip warning.
11074 while Lval /= 2 loop
11075 if Lval mod 2 = 1 then
11086 -- Keep looking at left operands
11088 Opnd := Left_Opnd (Opnd);
11089 end loop Opnd_Loop;
11091 -- For rem or "/" we can only have a problematic situation
11092 -- if the divisor has a value of minus one or one. Otherwise
11093 -- overflow is impossible (divisor > 1) or we have a case of
11094 -- division by zero in any case.
11096 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11097 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11098 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11103 -- If we fall through warning should be issued
11105 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11108 ("??unary minus expression should be parenthesized here!", N);
11112 end Resolve_Unary_Op;
11114 ----------------------------------
11115 -- Resolve_Unchecked_Expression --
11116 ----------------------------------
11118 procedure Resolve_Unchecked_Expression
11123 Resolve (Expression (N), Typ, Suppress => All_Checks);
11124 Set_Etype (N, Typ);
11125 end Resolve_Unchecked_Expression;
11127 ---------------------------------------
11128 -- Resolve_Unchecked_Type_Conversion --
11129 ---------------------------------------
11131 procedure Resolve_Unchecked_Type_Conversion
11135 pragma Warnings (Off, Typ);
11137 Operand : constant Node_Id := Expression (N);
11138 Opnd_Type : constant Entity_Id := Etype (Operand);
11141 -- Resolve operand using its own type
11143 Resolve (Operand, Opnd_Type);
11145 -- In an inlined context, the unchecked conversion may be applied
11146 -- to a literal, in which case its type is the type of the context.
11147 -- (In other contexts conversions cannot apply to literals).
11150 and then (Opnd_Type = Any_Character or else
11151 Opnd_Type = Any_Integer or else
11152 Opnd_Type = Any_Real)
11154 Set_Etype (Operand, Typ);
11157 Analyze_Dimension (N);
11158 Eval_Unchecked_Conversion (N);
11159 end Resolve_Unchecked_Type_Conversion;
11161 ------------------------------
11162 -- Rewrite_Operator_As_Call --
11163 ------------------------------
11165 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11166 Loc : constant Source_Ptr := Sloc (N);
11167 Actuals : constant List_Id := New_List;
11171 if Nkind (N) in N_Binary_Op then
11172 Append (Left_Opnd (N), Actuals);
11175 Append (Right_Opnd (N), Actuals);
11178 Make_Function_Call (Sloc => Loc,
11179 Name => New_Occurrence_Of (Nam, Loc),
11180 Parameter_Associations => Actuals);
11182 Preserve_Comes_From_Source (New_N, N);
11183 Preserve_Comes_From_Source (Name (New_N), N);
11184 Rewrite (N, New_N);
11185 Set_Etype (N, Etype (Nam));
11186 end Rewrite_Operator_As_Call;
11188 ------------------------------
11189 -- Rewrite_Renamed_Operator --
11190 ------------------------------
11192 procedure Rewrite_Renamed_Operator
11197 Nam : constant Name_Id := Chars (Op);
11198 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11202 -- Do not perform this transformation within a pre/postcondition,
11203 -- because the expression will be re-analyzed, and the transformation
11204 -- might affect the visibility of the operator, e.g. in an instance.
11206 if In_Assertion_Expr > 0 then
11210 -- Rewrite the operator node using the real operator, not its renaming.
11211 -- Exclude user-defined intrinsic operations of the same name, which are
11212 -- treated separately and rewritten as calls.
11214 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11215 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11216 Set_Chars (Op_Node, Nam);
11217 Set_Etype (Op_Node, Etype (N));
11218 Set_Entity (Op_Node, Op);
11219 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11221 -- Indicate that both the original entity and its renaming are
11222 -- referenced at this point.
11224 Generate_Reference (Entity (N), N);
11225 Generate_Reference (Op, N);
11228 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11231 Rewrite (N, Op_Node);
11233 -- If the context type is private, add the appropriate conversions so
11234 -- that the operator is applied to the full view. This is done in the
11235 -- routines that resolve intrinsic operators.
11237 if Is_Intrinsic_Subprogram (Op)
11238 and then Is_Private_Type (Typ)
11241 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11242 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11243 Resolve_Intrinsic_Operator (N, Typ);
11245 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11246 Resolve_Intrinsic_Unary_Operator (N, Typ);
11253 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11255 -- Operator renames a user-defined operator of the same name. Use the
11256 -- original operator in the node, which is the one Gigi knows about.
11258 Set_Entity (N, Op);
11259 Set_Is_Overloaded (N, False);
11261 end Rewrite_Renamed_Operator;
11263 -----------------------
11264 -- Set_Slice_Subtype --
11265 -----------------------
11267 -- Build an implicit subtype declaration to represent the type delivered by
11268 -- the slice. This is an abbreviated version of an array subtype. We define
11269 -- an index subtype for the slice, using either the subtype name or the
11270 -- discrete range of the slice. To be consistent with index usage elsewhere
11271 -- we create a list header to hold the single index. This list is not
11272 -- otherwise attached to the syntax tree.
11274 procedure Set_Slice_Subtype (N : Node_Id) is
11275 Loc : constant Source_Ptr := Sloc (N);
11276 Index_List : constant List_Id := New_List;
11278 Index_Subtype : Entity_Id;
11279 Index_Type : Entity_Id;
11280 Slice_Subtype : Entity_Id;
11281 Drange : constant Node_Id := Discrete_Range (N);
11284 Index_Type := Base_Type (Etype (Drange));
11286 if Is_Entity_Name (Drange) then
11287 Index_Subtype := Entity (Drange);
11290 -- We force the evaluation of a range. This is definitely needed in
11291 -- the renamed case, and seems safer to do unconditionally. Note in
11292 -- any case that since we will create and insert an Itype referring
11293 -- to this range, we must make sure any side effect removal actions
11294 -- are inserted before the Itype definition.
11296 if Nkind (Drange) = N_Range then
11297 Force_Evaluation (Low_Bound (Drange));
11298 Force_Evaluation (High_Bound (Drange));
11300 -- If the discrete range is given by a subtype indication, the
11301 -- type of the slice is the base of the subtype mark.
11303 elsif Nkind (Drange) = N_Subtype_Indication then
11305 R : constant Node_Id := Range_Expression (Constraint (Drange));
11307 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11308 Force_Evaluation (Low_Bound (R));
11309 Force_Evaluation (High_Bound (R));
11313 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11315 -- Take a new copy of Drange (where bounds have been rewritten to
11316 -- reference side-effect-free names). Using a separate tree ensures
11317 -- that further expansion (e.g. while rewriting a slice assignment
11318 -- into a FOR loop) does not attempt to remove side effects on the
11319 -- bounds again (which would cause the bounds in the index subtype
11320 -- definition to refer to temporaries before they are defined) (the
11321 -- reason is that some names are considered side effect free here
11322 -- for the subtype, but not in the context of a loop iteration
11325 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11326 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11327 Set_Etype (Index_Subtype, Index_Type);
11328 Set_Size_Info (Index_Subtype, Index_Type);
11329 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11332 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11334 Index := New_Occurrence_Of (Index_Subtype, Loc);
11335 Set_Etype (Index, Index_Subtype);
11336 Append (Index, Index_List);
11338 Set_First_Index (Slice_Subtype, Index);
11339 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11340 Set_Is_Constrained (Slice_Subtype, True);
11342 Check_Compile_Time_Size (Slice_Subtype);
11344 -- The Etype of the existing Slice node is reset to this slice subtype.
11345 -- Its bounds are obtained from its first index.
11347 Set_Etype (N, Slice_Subtype);
11349 -- For packed slice subtypes, freeze immediately (except in the case of
11350 -- being in a "spec expression" where we never freeze when we first see
11351 -- the expression).
11353 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11354 Freeze_Itype (Slice_Subtype, N);
11356 -- For all other cases insert an itype reference in the slice's actions
11357 -- so that the itype is frozen at the proper place in the tree (i.e. at
11358 -- the point where actions for the slice are analyzed). Note that this
11359 -- is different from freezing the itype immediately, which might be
11360 -- premature (e.g. if the slice is within a transient scope). This needs
11361 -- to be done only if expansion is enabled.
11363 elsif Expander_Active then
11364 Ensure_Defined (Typ => Slice_Subtype, N => N);
11366 end Set_Slice_Subtype;
11368 --------------------------------
11369 -- Set_String_Literal_Subtype --
11370 --------------------------------
11372 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11373 Loc : constant Source_Ptr := Sloc (N);
11374 Low_Bound : constant Node_Id :=
11375 Type_Low_Bound (Etype (First_Index (Typ)));
11376 Subtype_Id : Entity_Id;
11379 if Nkind (N) /= N_String_Literal then
11383 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11384 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11385 (String_Length (Strval (N))));
11386 Set_Etype (Subtype_Id, Base_Type (Typ));
11387 Set_Is_Constrained (Subtype_Id);
11388 Set_Etype (N, Subtype_Id);
11390 -- The low bound is set from the low bound of the corresponding index
11391 -- type. Note that we do not store the high bound in the string literal
11392 -- subtype, but it can be deduced if necessary from the length and the
11395 if Is_OK_Static_Expression (Low_Bound) then
11396 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11398 -- If the lower bound is not static we create a range for the string
11399 -- literal, using the index type and the known length of the literal.
11400 -- The index type is not necessarily Positive, so the upper bound is
11401 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11405 Index_List : constant List_Id := New_List;
11406 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11407 High_Bound : constant Node_Id :=
11408 Make_Attribute_Reference (Loc,
11409 Attribute_Name => Name_Val,
11411 New_Occurrence_Of (Index_Type, Loc),
11412 Expressions => New_List (
11415 Make_Attribute_Reference (Loc,
11416 Attribute_Name => Name_Pos,
11418 New_Occurrence_Of (Index_Type, Loc),
11420 New_List (New_Copy_Tree (Low_Bound))),
11422 Make_Integer_Literal (Loc,
11423 String_Length (Strval (N)) - 1))));
11425 Array_Subtype : Entity_Id;
11428 Index_Subtype : Entity_Id;
11431 if Is_Integer_Type (Index_Type) then
11432 Set_String_Literal_Low_Bound
11433 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11436 -- If the index type is an enumeration type, build bounds
11437 -- expression with attributes.
11439 Set_String_Literal_Low_Bound
11441 Make_Attribute_Reference (Loc,
11442 Attribute_Name => Name_First,
11444 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11445 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11448 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11450 -- Build bona fide subtype for the string, and wrap it in an
11451 -- unchecked conversion, because the backend expects the
11452 -- String_Literal_Subtype to have a static lower bound.
11455 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11456 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11457 Set_Scalar_Range (Index_Subtype, Drange);
11458 Set_Parent (Drange, N);
11459 Analyze_And_Resolve (Drange, Index_Type);
11461 -- In the context, the Index_Type may already have a constraint,
11462 -- so use common base type on string subtype. The base type may
11463 -- be used when generating attributes of the string, for example
11464 -- in the context of a slice assignment.
11466 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11467 Set_Size_Info (Index_Subtype, Index_Type);
11468 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11470 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11472 Index := New_Occurrence_Of (Index_Subtype, Loc);
11473 Set_Etype (Index, Index_Subtype);
11474 Append (Index, Index_List);
11476 Set_First_Index (Array_Subtype, Index);
11477 Set_Etype (Array_Subtype, Base_Type (Typ));
11478 Set_Is_Constrained (Array_Subtype, True);
11481 Make_Unchecked_Type_Conversion (Loc,
11482 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11483 Expression => Relocate_Node (N)));
11484 Set_Etype (N, Array_Subtype);
11487 end Set_String_Literal_Subtype;
11489 ------------------------------
11490 -- Simplify_Type_Conversion --
11491 ------------------------------
11493 procedure Simplify_Type_Conversion (N : Node_Id) is
11495 if Nkind (N) = N_Type_Conversion then
11497 Operand : constant Node_Id := Expression (N);
11498 Target_Typ : constant Entity_Id := Etype (N);
11499 Opnd_Typ : constant Entity_Id := Etype (Operand);
11502 -- Special processing if the conversion is the expression of a
11503 -- Rounding or Truncation attribute reference. In this case we
11506 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11512 -- with the Float_Truncate flag set to False or True respectively,
11513 -- which is more efficient.
11515 if Is_Floating_Point_Type (Opnd_Typ)
11517 (Is_Integer_Type (Target_Typ)
11518 or else (Is_Fixed_Point_Type (Target_Typ)
11519 and then Conversion_OK (N)))
11520 and then Nkind (Operand) = N_Attribute_Reference
11521 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11525 Truncate : constant Boolean :=
11526 Attribute_Name (Operand) = Name_Truncation;
11529 Relocate_Node (First (Expressions (Operand))));
11530 Set_Float_Truncate (N, Truncate);
11535 end Simplify_Type_Conversion;
11537 -----------------------------
11538 -- Unique_Fixed_Point_Type --
11539 -----------------------------
11541 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11542 T1 : Entity_Id := Empty;
11547 procedure Fixed_Point_Error;
11548 -- Give error messages for true ambiguity. Messages are posted on node
11549 -- N, and entities T1, T2 are the possible interpretations.
11551 -----------------------
11552 -- Fixed_Point_Error --
11553 -----------------------
11555 procedure Fixed_Point_Error is
11557 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11558 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11559 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11560 end Fixed_Point_Error;
11562 -- Start of processing for Unique_Fixed_Point_Type
11565 -- The operations on Duration are visible, so Duration is always a
11566 -- possible interpretation.
11568 T1 := Standard_Duration;
11570 -- Look for fixed-point types in enclosing scopes
11572 Scop := Current_Scope;
11573 while Scop /= Standard_Standard loop
11574 T2 := First_Entity (Scop);
11575 while Present (T2) loop
11576 if Is_Fixed_Point_Type (T2)
11577 and then Current_Entity (T2) = T2
11578 and then Scope (Base_Type (T2)) = Scop
11580 if Present (T1) then
11591 Scop := Scope (Scop);
11594 -- Look for visible fixed type declarations in the context
11596 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11597 while Present (Item) loop
11598 if Nkind (Item) = N_With_Clause then
11599 Scop := Entity (Name (Item));
11600 T2 := First_Entity (Scop);
11601 while Present (T2) loop
11602 if Is_Fixed_Point_Type (T2)
11603 and then Scope (Base_Type (T2)) = Scop
11604 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11606 if Present (T1) then
11621 if Nkind (N) = N_Real_Literal then
11623 ("??real literal interpreted as }!", N, T1);
11626 ("??universal_fixed expression interpreted as }!", N, T1);
11630 end Unique_Fixed_Point_Type;
11632 ----------------------
11633 -- Valid_Conversion --
11634 ----------------------
11636 function Valid_Conversion
11638 Target : Entity_Id;
11640 Report_Errs : Boolean := True) return Boolean
11642 Target_Type : constant Entity_Id := Base_Type (Target);
11643 Opnd_Type : Entity_Id := Etype (Operand);
11644 Inc_Ancestor : Entity_Id;
11646 function Conversion_Check
11648 Msg : String) return Boolean;
11649 -- Little routine to post Msg if Valid is False, returns Valid value
11651 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11652 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11654 procedure Conversion_Error_NE
11656 N : Node_Or_Entity_Id;
11657 E : Node_Or_Entity_Id);
11658 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11660 function Valid_Tagged_Conversion
11661 (Target_Type : Entity_Id;
11662 Opnd_Type : Entity_Id) return Boolean;
11663 -- Specifically test for validity of tagged conversions
11665 function Valid_Array_Conversion return Boolean;
11666 -- Check index and component conformance, and accessibility levels if
11667 -- the component types are anonymous access types (Ada 2005).
11669 ----------------------
11670 -- Conversion_Check --
11671 ----------------------
11673 function Conversion_Check
11675 Msg : String) return Boolean
11680 -- A generic unit has already been analyzed and we have verified
11681 -- that a particular conversion is OK in that context. Since the
11682 -- instance is reanalyzed without relying on the relationships
11683 -- established during the analysis of the generic, it is possible
11684 -- to end up with inconsistent views of private types. Do not emit
11685 -- the error message in such cases. The rest of the machinery in
11686 -- Valid_Conversion still ensures the proper compatibility of
11687 -- target and operand types.
11689 and then not In_Instance
11691 Conversion_Error_N (Msg, Operand);
11695 end Conversion_Check;
11697 ------------------------
11698 -- Conversion_Error_N --
11699 ------------------------
11701 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11703 if Report_Errs then
11704 Error_Msg_N (Msg, N);
11706 end Conversion_Error_N;
11708 -------------------------
11709 -- Conversion_Error_NE --
11710 -------------------------
11712 procedure Conversion_Error_NE
11714 N : Node_Or_Entity_Id;
11715 E : Node_Or_Entity_Id)
11718 if Report_Errs then
11719 Error_Msg_NE (Msg, N, E);
11721 end Conversion_Error_NE;
11723 ----------------------------
11724 -- Valid_Array_Conversion --
11725 ----------------------------
11727 function Valid_Array_Conversion return Boolean
11729 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11730 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11732 Opnd_Index : Node_Id;
11733 Opnd_Index_Type : Entity_Id;
11735 Target_Comp_Type : constant Entity_Id :=
11736 Component_Type (Target_Type);
11737 Target_Comp_Base : constant Entity_Id :=
11738 Base_Type (Target_Comp_Type);
11740 Target_Index : Node_Id;
11741 Target_Index_Type : Entity_Id;
11744 -- Error if wrong number of dimensions
11747 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11750 ("incompatible number of dimensions for conversion", Operand);
11753 -- Number of dimensions matches
11756 -- Loop through indexes of the two arrays
11758 Target_Index := First_Index (Target_Type);
11759 Opnd_Index := First_Index (Opnd_Type);
11760 while Present (Target_Index) and then Present (Opnd_Index) loop
11761 Target_Index_Type := Etype (Target_Index);
11762 Opnd_Index_Type := Etype (Opnd_Index);
11764 -- Error if index types are incompatible
11766 if not (Is_Integer_Type (Target_Index_Type)
11767 and then Is_Integer_Type (Opnd_Index_Type))
11768 and then (Root_Type (Target_Index_Type)
11769 /= Root_Type (Opnd_Index_Type))
11772 ("incompatible index types for array conversion",
11777 Next_Index (Target_Index);
11778 Next_Index (Opnd_Index);
11781 -- If component types have same base type, all set
11783 if Target_Comp_Base = Opnd_Comp_Base then
11786 -- Here if base types of components are not the same. The only
11787 -- time this is allowed is if we have anonymous access types.
11789 -- The conversion of arrays of anonymous access types can lead
11790 -- to dangling pointers. AI-392 formalizes the accessibility
11791 -- checks that must be applied to such conversions to prevent
11792 -- out-of-scope references.
11795 (Target_Comp_Base, E_Anonymous_Access_Type,
11796 E_Anonymous_Access_Subprogram_Type)
11797 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11799 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11801 if Type_Access_Level (Target_Type) <
11802 Deepest_Type_Access_Level (Opnd_Type)
11804 if In_Instance_Body then
11805 Error_Msg_Warn := SPARK_Mode /= On;
11807 ("source array type has deeper accessibility "
11808 & "level than target<<", Operand);
11809 Conversion_Error_N ("\Program_Error [<<", Operand);
11811 Make_Raise_Program_Error (Sloc (N),
11812 Reason => PE_Accessibility_Check_Failed));
11813 Set_Etype (N, Target_Type);
11816 -- Conversion not allowed because of accessibility levels
11820 ("source array type has deeper accessibility "
11821 & "level than target", Operand);
11829 -- All other cases where component base types do not match
11833 ("incompatible component types for array conversion",
11838 -- Check that component subtypes statically match. For numeric
11839 -- types this means that both must be either constrained or
11840 -- unconstrained. For enumeration types the bounds must match.
11841 -- All of this is checked in Subtypes_Statically_Match.
11843 if not Subtypes_Statically_Match
11844 (Target_Comp_Type, Opnd_Comp_Type)
11847 ("component subtypes must statically match", Operand);
11853 end Valid_Array_Conversion;
11855 -----------------------------
11856 -- Valid_Tagged_Conversion --
11857 -----------------------------
11859 function Valid_Tagged_Conversion
11860 (Target_Type : Entity_Id;
11861 Opnd_Type : Entity_Id) return Boolean
11864 -- Upward conversions are allowed (RM 4.6(22))
11866 if Covers (Target_Type, Opnd_Type)
11867 or else Is_Ancestor (Target_Type, Opnd_Type)
11871 -- Downward conversion are allowed if the operand is class-wide
11874 elsif Is_Class_Wide_Type (Opnd_Type)
11875 and then Covers (Opnd_Type, Target_Type)
11879 elsif Covers (Opnd_Type, Target_Type)
11880 or else Is_Ancestor (Opnd_Type, Target_Type)
11883 Conversion_Check (False,
11884 "downward conversion of tagged objects not allowed");
11886 -- Ada 2005 (AI-251): The conversion to/from interface types is
11889 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
11892 -- If the operand is a class-wide type obtained through a limited_
11893 -- with clause, and the context includes the non-limited view, use
11894 -- it to determine whether the conversion is legal.
11896 elsif Is_Class_Wide_Type (Opnd_Type)
11897 and then From_Limited_With (Opnd_Type)
11898 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11899 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11903 elsif Is_Access_Type (Opnd_Type)
11904 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11909 Conversion_Error_NE
11910 ("invalid tagged conversion, not compatible with}",
11911 N, First_Subtype (Opnd_Type));
11914 end Valid_Tagged_Conversion;
11916 -- Start of processing for Valid_Conversion
11919 Check_Parameterless_Call (Operand);
11921 if Is_Overloaded (Operand) then
11931 -- Remove procedure calls, which syntactically cannot appear in
11932 -- this context, but which cannot be removed by type checking,
11933 -- because the context does not impose a type.
11935 -- The node may be labelled overloaded, but still contain only one
11936 -- interpretation because others were discarded earlier. If this
11937 -- is the case, retain the single interpretation if legal.
11939 Get_First_Interp (Operand, I, It);
11940 Opnd_Type := It.Typ;
11941 Get_Next_Interp (I, It);
11943 if Present (It.Typ)
11944 and then Opnd_Type /= Standard_Void_Type
11946 -- More than one candidate interpretation is available
11948 Get_First_Interp (Operand, I, It);
11949 while Present (It.Typ) loop
11950 if It.Typ = Standard_Void_Type then
11954 -- When compiling for a system where Address is of a visible
11955 -- integer type, spurious ambiguities can be produced when
11956 -- arithmetic operations have a literal operand and return
11957 -- System.Address or a descendant of it. These ambiguities
11958 -- are usually resolved by the context, but for conversions
11959 -- there is no context type and the removal of the spurious
11960 -- operations must be done explicitly here.
11962 if not Address_Is_Private
11963 and then Is_Descendent_Of_Address (It.Typ)
11968 Get_Next_Interp (I, It);
11972 Get_First_Interp (Operand, I, It);
11976 if No (It.Typ) then
11977 Conversion_Error_N ("illegal operand in conversion", Operand);
11981 Get_Next_Interp (I, It);
11983 if Present (It.Typ) then
11986 It1 := Disambiguate (Operand, I1, I, Any_Type);
11988 if It1 = No_Interp then
11990 ("ambiguous operand in conversion", Operand);
11992 -- If the interpretation involves a standard operator, use
11993 -- the location of the type, which may be user-defined.
11995 if Sloc (It.Nam) = Standard_Location then
11996 Error_Msg_Sloc := Sloc (It.Typ);
11998 Error_Msg_Sloc := Sloc (It.Nam);
12001 Conversion_Error_N -- CODEFIX
12002 ("\\possible interpretation#!", Operand);
12004 if Sloc (N1) = Standard_Location then
12005 Error_Msg_Sloc := Sloc (T1);
12007 Error_Msg_Sloc := Sloc (N1);
12010 Conversion_Error_N -- CODEFIX
12011 ("\\possible interpretation#!", Operand);
12017 Set_Etype (Operand, It1.Typ);
12018 Opnd_Type := It1.Typ;
12022 -- Deal with conversion of integer type to address if the pragma
12023 -- Allow_Integer_Address is in effect. We convert the conversion to
12024 -- an unchecked conversion in this case and we are all done.
12026 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12027 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12028 Analyze_And_Resolve (N, Target_Type);
12032 -- If we are within a child unit, check whether the type of the
12033 -- expression has an ancestor in a parent unit, in which case it
12034 -- belongs to its derivation class even if the ancestor is private.
12035 -- See RM 7.3.1 (5.2/3).
12037 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12041 if Is_Numeric_Type (Target_Type) then
12043 -- A universal fixed expression can be converted to any numeric type
12045 if Opnd_Type = Universal_Fixed then
12048 -- Also no need to check when in an instance or inlined body, because
12049 -- the legality has been established when the template was analyzed.
12050 -- Furthermore, numeric conversions may occur where only a private
12051 -- view of the operand type is visible at the instantiation point.
12052 -- This results in a spurious error if we check that the operand type
12053 -- is a numeric type.
12055 -- Note: in a previous version of this unit, the following tests were
12056 -- applied only for generated code (Comes_From_Source set to False),
12057 -- but in fact the test is required for source code as well, since
12058 -- this situation can arise in source code.
12060 elsif In_Instance or else In_Inlined_Body then
12063 -- Otherwise we need the conversion check
12066 return Conversion_Check
12067 (Is_Numeric_Type (Opnd_Type)
12069 (Present (Inc_Ancestor)
12070 and then Is_Numeric_Type (Inc_Ancestor)),
12071 "illegal operand for numeric conversion");
12076 elsif Is_Array_Type (Target_Type) then
12077 if not Is_Array_Type (Opnd_Type)
12078 or else Opnd_Type = Any_Composite
12079 or else Opnd_Type = Any_String
12082 ("illegal operand for array conversion", Operand);
12086 return Valid_Array_Conversion;
12089 -- Ada 2005 (AI-251): Internally generated conversions of access to
12090 -- interface types added to force the displacement of the pointer to
12091 -- reference the corresponding dispatch table.
12093 elsif not Comes_From_Source (N)
12094 and then Is_Access_Type (Target_Type)
12095 and then Is_Interface (Designated_Type (Target_Type))
12099 -- Ada 2005 (AI-251): Anonymous access types where target references an
12102 elsif Ekind_In (Target_Type, E_General_Access_Type,
12103 E_Anonymous_Access_Type)
12104 and then Is_Interface (Directly_Designated_Type (Target_Type))
12106 -- Check the static accessibility rule of 4.6(17). Note that the
12107 -- check is not enforced when within an instance body, since the
12108 -- RM requires such cases to be caught at run time.
12110 -- If the operand is a rewriting of an allocator no check is needed
12111 -- because there are no accessibility issues.
12113 if Nkind (Original_Node (N)) = N_Allocator then
12116 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12117 if Type_Access_Level (Opnd_Type) >
12118 Deepest_Type_Access_Level (Target_Type)
12120 -- In an instance, this is a run-time check, but one we know
12121 -- will fail, so generate an appropriate warning. The raise
12122 -- will be generated by Expand_N_Type_Conversion.
12124 if In_Instance_Body then
12125 Error_Msg_Warn := SPARK_Mode /= On;
12127 ("cannot convert local pointer to non-local access type<<",
12129 Conversion_Error_N ("\Program_Error [<<", Operand);
12133 ("cannot convert local pointer to non-local access type",
12138 -- Special accessibility checks are needed in the case of access
12139 -- discriminants declared for a limited type.
12141 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12142 and then not Is_Local_Anonymous_Access (Opnd_Type)
12144 -- When the operand is a selected access discriminant the check
12145 -- needs to be made against the level of the object denoted by
12146 -- the prefix of the selected name (Object_Access_Level handles
12147 -- checking the prefix of the operand for this case).
12149 if Nkind (Operand) = N_Selected_Component
12150 and then Object_Access_Level (Operand) >
12151 Deepest_Type_Access_Level (Target_Type)
12153 -- In an instance, this is a run-time check, but one we know
12154 -- will fail, so generate an appropriate warning. The raise
12155 -- will be generated by Expand_N_Type_Conversion.
12157 if In_Instance_Body then
12158 Error_Msg_Warn := SPARK_Mode /= On;
12160 ("cannot convert access discriminant to non-local "
12161 & "access type<<", Operand);
12162 Conversion_Error_N ("\Program_Error [<<", Operand);
12164 -- Real error if not in instance body
12168 ("cannot convert access discriminant to non-local "
12169 & "access type", Operand);
12174 -- The case of a reference to an access discriminant from
12175 -- within a limited type declaration (which will appear as
12176 -- a discriminal) is always illegal because the level of the
12177 -- discriminant is considered to be deeper than any (nameable)
12180 if Is_Entity_Name (Operand)
12181 and then not Is_Local_Anonymous_Access (Opnd_Type)
12183 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12184 and then Present (Discriminal_Link (Entity (Operand)))
12187 ("discriminant has deeper accessibility level than target",
12196 -- General and anonymous access types
12198 elsif Ekind_In (Target_Type, E_General_Access_Type,
12199 E_Anonymous_Access_Type)
12202 (Is_Access_Type (Opnd_Type)
12204 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12205 E_Access_Protected_Subprogram_Type),
12206 "must be an access-to-object type")
12208 if Is_Access_Constant (Opnd_Type)
12209 and then not Is_Access_Constant (Target_Type)
12212 ("access-to-constant operand type not allowed", Operand);
12216 -- Check the static accessibility rule of 4.6(17). Note that the
12217 -- check is not enforced when within an instance body, since the RM
12218 -- requires such cases to be caught at run time.
12220 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12221 or else Is_Local_Anonymous_Access (Target_Type)
12222 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12223 N_Object_Declaration
12225 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12226 -- conversions from an anonymous access type to a named general
12227 -- access type. Such conversions are not allowed in the case of
12228 -- access parameters and stand-alone objects of an anonymous
12229 -- access type. The implicit conversion case is recognized by
12230 -- testing that Comes_From_Source is False and that it's been
12231 -- rewritten. The Comes_From_Source test isn't sufficient because
12232 -- nodes in inlined calls to predefined library routines can have
12233 -- Comes_From_Source set to False. (Is there a better way to test
12234 -- for implicit conversions???)
12236 if Ada_Version >= Ada_2012
12237 and then not Comes_From_Source (N)
12238 and then N /= Original_Node (N)
12239 and then Ekind (Target_Type) = E_General_Access_Type
12240 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12242 if Is_Itype (Opnd_Type) then
12244 -- Implicit conversions aren't allowed for objects of an
12245 -- anonymous access type, since such objects have nonstatic
12246 -- levels in Ada 2012.
12248 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12249 N_Object_Declaration
12252 ("implicit conversion of stand-alone anonymous "
12253 & "access object not allowed", Operand);
12256 -- Implicit conversions aren't allowed for anonymous access
12257 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12258 -- is done to exclude anonymous access results.
12260 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12261 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12262 N_Function_Specification,
12263 N_Procedure_Specification)
12266 ("implicit conversion of anonymous access formal "
12267 & "not allowed", Operand);
12270 -- This is a case where there's an enclosing object whose
12271 -- to which the "statically deeper than" relationship does
12272 -- not apply (such as an access discriminant selected from
12273 -- a dereference of an access parameter).
12275 elsif Object_Access_Level (Operand)
12276 = Scope_Depth (Standard_Standard)
12279 ("implicit conversion of anonymous access value "
12280 & "not allowed", Operand);
12283 -- In other cases, the level of the operand's type must be
12284 -- statically less deep than that of the target type, else
12285 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12287 elsif Type_Access_Level (Opnd_Type) >
12288 Deepest_Type_Access_Level (Target_Type)
12291 ("implicit conversion of anonymous access value "
12292 & "violates accessibility", Operand);
12297 elsif Type_Access_Level (Opnd_Type) >
12298 Deepest_Type_Access_Level (Target_Type)
12300 -- In an instance, this is a run-time check, but one we know
12301 -- will fail, so generate an appropriate warning. The raise
12302 -- will be generated by Expand_N_Type_Conversion.
12304 if In_Instance_Body then
12305 Error_Msg_Warn := SPARK_Mode /= On;
12307 ("cannot convert local pointer to non-local access type<<",
12309 Conversion_Error_N ("\Program_Error [<<", Operand);
12311 -- If not in an instance body, this is a real error
12314 -- Avoid generation of spurious error message
12316 if not Error_Posted (N) then
12318 ("cannot convert local pointer to non-local access type",
12325 -- Special accessibility checks are needed in the case of access
12326 -- discriminants declared for a limited type.
12328 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12329 and then not Is_Local_Anonymous_Access (Opnd_Type)
12331 -- When the operand is a selected access discriminant the check
12332 -- needs to be made against the level of the object denoted by
12333 -- the prefix of the selected name (Object_Access_Level handles
12334 -- checking the prefix of the operand for this case).
12336 if Nkind (Operand) = N_Selected_Component
12337 and then Object_Access_Level (Operand) >
12338 Deepest_Type_Access_Level (Target_Type)
12340 -- In an instance, this is a run-time check, but one we know
12341 -- will fail, so generate an appropriate warning. The raise
12342 -- will be generated by Expand_N_Type_Conversion.
12344 if In_Instance_Body then
12345 Error_Msg_Warn := SPARK_Mode /= On;
12347 ("cannot convert access discriminant to non-local "
12348 & "access type<<", Operand);
12349 Conversion_Error_N ("\Program_Error [<<", Operand);
12351 -- If not in an instance body, this is a real error
12355 ("cannot convert access discriminant to non-local "
12356 & "access type", Operand);
12361 -- The case of a reference to an access discriminant from
12362 -- within a limited type declaration (which will appear as
12363 -- a discriminal) is always illegal because the level of the
12364 -- discriminant is considered to be deeper than any (nameable)
12367 if Is_Entity_Name (Operand)
12369 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12370 and then Present (Discriminal_Link (Entity (Operand)))
12373 ("discriminant has deeper accessibility level than target",
12380 -- In the presence of limited_with clauses we have to use non-limited
12381 -- views, if available.
12383 Check_Limited : declare
12384 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12385 -- Helper function to handle limited views
12387 --------------------------
12388 -- Full_Designated_Type --
12389 --------------------------
12391 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12392 Desig : constant Entity_Id := Designated_Type (T);
12395 -- Handle the limited view of a type
12397 if Is_Incomplete_Type (Desig)
12398 and then From_Limited_With (Desig)
12399 and then Present (Non_Limited_View (Desig))
12401 return Available_View (Desig);
12405 end Full_Designated_Type;
12407 -- Local Declarations
12409 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12410 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12412 Same_Base : constant Boolean :=
12413 Base_Type (Target) = Base_Type (Opnd);
12415 -- Start of processing for Check_Limited
12418 if Is_Tagged_Type (Target) then
12419 return Valid_Tagged_Conversion (Target, Opnd);
12422 if not Same_Base then
12423 Conversion_Error_NE
12424 ("target designated type not compatible with }",
12425 N, Base_Type (Opnd));
12428 -- Ada 2005 AI-384: legality rule is symmetric in both
12429 -- designated types. The conversion is legal (with possible
12430 -- constraint check) if either designated type is
12433 elsif Subtypes_Statically_Match (Target, Opnd)
12435 (Has_Discriminants (Target)
12437 (not Is_Constrained (Opnd)
12438 or else not Is_Constrained (Target)))
12440 -- Special case, if Value_Size has been used to make the
12441 -- sizes different, the conversion is not allowed even
12442 -- though the subtypes statically match.
12444 if Known_Static_RM_Size (Target)
12445 and then Known_Static_RM_Size (Opnd)
12446 and then RM_Size (Target) /= RM_Size (Opnd)
12448 Conversion_Error_NE
12449 ("target designated subtype not compatible with }",
12451 Conversion_Error_NE
12452 ("\because sizes of the two designated subtypes differ",
12456 -- Normal case where conversion is allowed
12464 ("target designated subtype not compatible with }",
12471 -- Access to subprogram types. If the operand is an access parameter,
12472 -- the type has a deeper accessibility that any master, and cannot be
12473 -- assigned. We must make an exception if the conversion is part of an
12474 -- assignment and the target is the return object of an extended return
12475 -- statement, because in that case the accessibility check takes place
12476 -- after the return.
12478 elsif Is_Access_Subprogram_Type (Target_Type)
12480 -- Note: this test of Opnd_Type is there to prevent entering this
12481 -- branch in the case of a remote access to subprogram type, which
12482 -- is internally represented as an E_Record_Type.
12484 and then Is_Access_Type (Opnd_Type)
12486 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12487 and then Is_Entity_Name (Operand)
12488 and then Ekind (Entity (Operand)) = E_In_Parameter
12490 (Nkind (Parent (N)) /= N_Assignment_Statement
12491 or else not Is_Entity_Name (Name (Parent (N)))
12492 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12495 ("illegal attempt to store anonymous access to subprogram",
12498 ("\value has deeper accessibility than any master "
12499 & "(RM 3.10.2 (13))",
12503 ("\use named access type for& instead of access parameter",
12504 Operand, Entity (Operand));
12507 -- Check that the designated types are subtype conformant
12509 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12510 Old_Id => Designated_Type (Opnd_Type),
12513 -- Check the static accessibility rule of 4.6(20)
12515 if Type_Access_Level (Opnd_Type) >
12516 Deepest_Type_Access_Level (Target_Type)
12519 ("operand type has deeper accessibility level than target",
12522 -- Check that if the operand type is declared in a generic body,
12523 -- then the target type must be declared within that same body
12524 -- (enforces last sentence of 4.6(20)).
12526 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12528 O_Gen : constant Node_Id :=
12529 Enclosing_Generic_Body (Opnd_Type);
12534 T_Gen := Enclosing_Generic_Body (Target_Type);
12535 while Present (T_Gen) and then T_Gen /= O_Gen loop
12536 T_Gen := Enclosing_Generic_Body (T_Gen);
12539 if T_Gen /= O_Gen then
12541 ("target type must be declared in same generic body "
12542 & "as operand type", N);
12549 -- Remote access to subprogram types
12551 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12552 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12554 -- It is valid to convert from one RAS type to another provided
12555 -- that their specification statically match.
12557 -- Note: at this point, remote access to subprogram types have been
12558 -- expanded to their E_Record_Type representation, and we need to
12559 -- go back to the original access type definition using the
12560 -- Corresponding_Remote_Type attribute in order to check that the
12561 -- designated profiles match.
12563 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12564 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12566 Check_Subtype_Conformant
12568 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12570 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12575 -- If it was legal in the generic, it's legal in the instance
12577 elsif In_Instance_Body then
12580 -- If both are tagged types, check legality of view conversions
12582 elsif Is_Tagged_Type (Target_Type)
12584 Is_Tagged_Type (Opnd_Type)
12586 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12588 -- Types derived from the same root type are convertible
12590 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12593 -- In an instance or an inlined body, there may be inconsistent views of
12594 -- the same type, or of types derived from a common root.
12596 elsif (In_Instance or In_Inlined_Body)
12598 Root_Type (Underlying_Type (Target_Type)) =
12599 Root_Type (Underlying_Type (Opnd_Type))
12603 -- Special check for common access type error case
12605 elsif Ekind (Target_Type) = E_Access_Type
12606 and then Is_Access_Type (Opnd_Type)
12608 Conversion_Error_N ("target type must be general access type!", N);
12609 Conversion_Error_NE -- CODEFIX
12610 ("add ALL to }!", N, Target_Type);
12613 -- Here we have a real conversion error
12616 Conversion_Error_NE
12617 ("invalid conversion, not compatible with }", N, Opnd_Type);
12620 end Valid_Conversion;