1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2019, 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_Ch6; use Exp_Ch6;
34 with Exp_Ch7; use Exp_Ch7;
35 with Exp_Disp; use Exp_Disp;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Freeze; use Freeze;
39 with Ghost; use Ghost;
40 with Inline; use Inline;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Par_SCO; use Par_SCO;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Aux; use Sem_Aux;
57 with Sem_Cat; use Sem_Cat;
58 with Sem_Ch3; use Sem_Ch3;
59 with Sem_Ch4; use Sem_Ch4;
60 with Sem_Ch6; use Sem_Ch6;
61 with Sem_Ch8; use Sem_Ch8;
62 with Sem_Ch13; use Sem_Ch13;
63 with Sem_Dim; use Sem_Dim;
64 with Sem_Disp; use Sem_Disp;
65 with Sem_Dist; use Sem_Dist;
66 with Sem_Elab; use Sem_Elab;
67 with Sem_Elim; use Sem_Elim;
68 with Sem_Eval; use Sem_Eval;
69 with Sem_Intr; use Sem_Intr;
70 with Sem_Mech; use Sem_Mech;
71 with Sem_Type; use Sem_Type;
72 with Sem_Util; use Sem_Util;
73 with Sem_Warn; use Sem_Warn;
74 with Sinfo; use Sinfo;
75 with Sinfo.CN; use Sinfo.CN;
76 with Snames; use Snames;
77 with Stand; use Stand;
78 with Stringt; use Stringt;
79 with Style; use Style;
80 with Targparm; use Targparm;
81 with Tbuild; use Tbuild;
82 with Uintp; use Uintp;
83 with Urealp; use Urealp;
85 package body Sem_Res is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use (N : Node_Id);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion (Call : Node_Id) return Boolean;
116 -- Given a call node, Call, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
122 -- N is the node for a logical operator. If the operator is predefined, and
123 -- the root type of the operands is Standard.Boolean, then a check is made
124 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
125 -- the style check for Style_Check_Boolean_And_Or.
127 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
128 -- N is either an indexed component or a selected component. This function
129 -- returns true if the prefix refers to an object that has an address
130 -- clause (the case in which we may want to issue a warning).
132 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
133 -- Determine whether E is an access type declared by an access declaration,
134 -- and not an (anonymous) allocator type.
136 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
137 -- Utility to check whether the entity for an operator is a predefined
138 -- operator, in which case the expression is left as an operator in the
139 -- tree (else it is rewritten into a call). An instance of an intrinsic
140 -- conversion operation may be given an operator name, but is not treated
141 -- like an operator. Note that an operator that is an imported back-end
142 -- builtin has convention Intrinsic, but is expected to be rewritten into
143 -- a call, so such an operator is not treated as predefined by this
146 procedure Preanalyze_And_Resolve
149 With_Freezing : Boolean);
150 -- Subsidiary of public versions of Preanalyze_And_Resolve.
152 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
153 -- If a default expression in entry call N depends on the discriminants
154 -- of the task, it must be replaced with a reference to the discriminant
155 -- of the task being called.
157 procedure Resolve_Op_Concat_Arg
162 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
163 -- concatenation operator. The operand is either of the array type or of
164 -- the component type. If the operand is an aggregate, and the component
165 -- type is composite, this is ambiguous if component type has aggregates.
167 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
168 -- Does the first part of the work of Resolve_Op_Concat
170 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
171 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
172 -- has been resolved. See Resolve_Op_Concat for details.
174 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Target_Name (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
211 function Operator_Kind
213 Is_Binary : Boolean) return Node_Kind;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
236 -- Ditto, for arithmetic unary operators
238 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
242 procedure Make_Call_Into_Operator
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so that
248 -- operands are resolved properly. Recall that predefined operators do not
249 -- have a full signature and special resolution rules apply.
251 procedure Rewrite_Renamed_Operator
255 -- An operator can rename another, e.g. in an instantiation. In that
256 -- case, the proper operator node must be constructed and resolved.
258 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
259 -- The String_Literal_Subtype is built for all strings that are not
260 -- operands of a static concatenation operation. If the argument is not
261 -- a N_String_Literal node, then the call has no effect.
263 procedure Set_Slice_Subtype (N : Node_Id);
264 -- Build subtype of array type, with the range specified by the slice
266 procedure Simplify_Type_Conversion (N : Node_Id);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Rounding or Truncation attribute.
271 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
277 -------------------------
278 -- Ambiguous_Character --
279 -------------------------
281 procedure Ambiguous_Character (C : Node_Id) is
285 if Nkind (C) = N_Character_Literal then
286 Error_Msg_N ("ambiguous character literal", C);
288 -- First the ones in Standard
290 Error_Msg_N ("\\possible interpretation: Character!", C);
291 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
293 -- Include Wide_Wide_Character in Ada 2005 mode
295 if Ada_Version >= Ada_2005 then
296 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
299 -- Now any other types that match
301 E := Current_Entity (C);
302 while Present (E) loop
303 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
307 end Ambiguous_Character;
309 -------------------------
310 -- Analyze_And_Resolve --
311 -------------------------
313 procedure Analyze_And_Resolve (N : Node_Id) is
317 end Analyze_And_Resolve;
319 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
323 end Analyze_And_Resolve;
325 -- Versions with check(s) suppressed
327 procedure Analyze_And_Resolve
332 Scop : constant Entity_Id := Current_Scope;
335 if Suppress = All_Checks then
337 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
339 Scope_Suppress.Suppress := (others => True);
340 Analyze_And_Resolve (N, Typ);
341 Scope_Suppress.Suppress := Sva;
346 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
348 Scope_Suppress.Suppress (Suppress) := True;
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress.Suppress (Suppress) := Svg;
354 if Current_Scope /= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
366 end Analyze_And_Resolve;
368 procedure Analyze_And_Resolve
372 Scop : constant Entity_Id := Current_Scope;
375 if Suppress = All_Checks then
377 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
379 Scope_Suppress.Suppress := (others => True);
380 Analyze_And_Resolve (N);
381 Scope_Suppress.Suppress := Sva;
386 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
388 Scope_Suppress.Suppress (Suppress) := True;
389 Analyze_And_Resolve (N);
390 Scope_Suppress.Suppress (Suppress) := Svg;
394 if Current_Scope /= Scop and then Scope_Is_Transient then
395 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
398 end Analyze_And_Resolve;
400 ----------------------------
401 -- Check_Discriminant_Use --
402 ----------------------------
404 procedure Check_Discriminant_Use (N : Node_Id) is
405 PN : constant Node_Id := Parent (N);
406 Disc : constant Entity_Id := Entity (N);
411 -- Any use in a spec-expression is legal
413 if In_Spec_Expression then
416 elsif Nkind (PN) = N_Range then
418 -- Discriminant cannot be used to constrain a scalar type
422 if Nkind (P) = N_Range_Constraint
423 and then Nkind (Parent (P)) = N_Subtype_Indication
424 and then Nkind (Parent (Parent (P))) = N_Component_Definition
426 Error_Msg_N ("discriminant cannot constrain scalar type", N);
428 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
430 -- The following check catches the unusual case where a
431 -- discriminant appears within an index constraint that is part
432 -- of a larger expression within a constraint on a component,
433 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
434 -- check case of record components, and note that a similar check
435 -- should also apply in the case of discriminant constraints
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
446 if Ekind (Current_Scope) = E_Record_Type
447 and then Scope (Disc) = Current_Scope
449 (Nkind (Parent (P)) = N_Subtype_Indication
451 Nkind_In (Parent (Parent (P)), N_Component_Definition,
452 N_Subtype_Declaration)
453 and then Paren_Count (N) = 0)
456 ("discriminant must appear alone in component constraint", N);
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large : declare
477 function Large_Storage_Type (T : Entity_Id) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type (T : Entity_Id) return Boolean is
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value (Type_Low_Bound (T))
493 and then Compile_Time_Known_Value (Type_High_Bound (T))
495 Minimum_Size (T, Biased => True) >=
496 RM_Size (Standard_Positive);
497 end Large_Storage_Type;
499 -- Start of processing for Check_Large
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type (Etype (Disc)) then
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
512 if Is_Limited_Type (Scope (Disc)) then
516 -- Check that it is the high bound
518 if N /= High_Bound (PN)
519 or else No (Discriminant_Default_Value (Disc))
524 -- Check the array allows a large range at this bound. First
529 if Nkind (SI) /= N_Subtype_Indication then
533 T := Entity (Subtype_Mark (SI));
535 if not Is_Array_Type (T) then
539 -- Next, find the dimension
541 TB := First_Index (T);
542 CB := First (Constraints (P));
544 and then Present (TB)
545 and then Present (CB)
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type (Etype (TB)) then
562 -- Warn about the danger
565 ("??creation of & object may raise Storage_Error!",
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
577 N_Discriminant_Association)
579 if Paren_Count (N) > 0 then
581 ("discriminant in constraint must appear alone", N);
583 elsif Nkind (N) = N_Expanded_Name
584 and then Comes_From_Source (N)
587 ("discriminant must appear alone as a direct name", N);
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
598 while not Nkind_In (P, N_Component_Declaration,
599 N_Subtype_Indication,
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind (P) = N_Subtype_Indication
613 and then Nkind_In (Parent (P), N_Component_Definition,
614 N_Derived_Type_Definition)
615 and then D = Constraint (P))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind (P) = N_Subtype_Indication
622 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
623 or else Nkind (P) = N_Entry_Declaration
624 or else Nkind (D) = N_Defining_Identifier
627 ("discriminant in constraint must appear alone", N);
630 end Check_Discriminant_Use;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
638 if Is_Invisible_Operator (N, T) then
639 Error_Msg_NE -- CODEFIX
640 ("operator for} is not directly visible!", N, First_Subtype (T));
641 Error_Msg_N -- CODEFIX
642 ("use clause would make operation legal!", N);
644 end Check_For_Visible_Operator;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name (Pref)
674 and then Ekind (Entity (Pref)) = E_In_Parameter
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version >= Ada_2005
683 and then Is_Entity_Name (Pref)
684 and then Is_Access_Type (Etype (Pref))
685 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
687 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
691 Check_Fully_Declared (Typ, Parent (Pref));
693 end Check_Fully_Declared_Prefix;
695 ------------------------------
696 -- Check_Infinite_Recursion --
697 ------------------------------
699 function Check_Infinite_Recursion (Call : Node_Id) return Boolean is
700 function Enclosing_Declaration_Or_Statement (N : Node_Id) return Node_Id;
701 -- Return the nearest enclosing declaration or statement that houses
704 function Invoked_With_Different_Arguments (N : Node_Id) return Boolean;
705 -- Determine whether call N invokes the related enclosing subprogram
706 -- with actuals that differ from the subprogram's formals.
708 function Is_Conditional_Statement (N : Node_Id) return Boolean;
709 -- Determine whether arbitrary node N denotes a conditional construct
711 function Is_Control_Flow_Statement (N : Node_Id) return Boolean;
712 -- Determine whether arbitrary node N denotes a control flow statement
713 -- or a construct that may contains such a statement.
715 function Is_Immediately_Within_Body (N : Node_Id) return Boolean;
716 -- Determine whether arbitrary node N appears immediately within the
717 -- statements of an entry or subprogram body.
719 function Is_Raise_Idiom (N : Node_Id) return Boolean;
720 -- Determine whether arbitrary node N appears immediately within the
721 -- body of an entry or subprogram, and is preceded by a single raise
724 function Is_Raise_Statement (N : Node_Id) return Boolean;
725 -- Determine whether arbitrary node N denotes a raise statement
727 function Is_Sole_Statement (N : Node_Id) return Boolean;
728 -- Determine whether arbitrary node N is the sole source statement in
729 -- the body of the enclosing subprogram.
731 function Preceded_By_Control_Flow_Statement (N : Node_Id) return Boolean;
732 -- Determine whether arbitrary node N is preceded by a control flow
735 function Within_Conditional_Statement (N : Node_Id) return Boolean;
736 -- Determine whether arbitrary node N appears within a conditional
739 ----------------------------------------
740 -- Enclosing_Declaration_Or_Statement --
741 ----------------------------------------
743 function Enclosing_Declaration_Or_Statement
744 (N : Node_Id) return Node_Id
750 while Present (Par) loop
751 if Is_Declaration (Par) or else Is_Statement (Par) then
754 -- Prevent the search from going too far
756 elsif Is_Body_Or_Package_Declaration (Par) then
764 end Enclosing_Declaration_Or_Statement;
766 --------------------------------------
767 -- Invoked_With_Different_Arguments --
768 --------------------------------------
770 function Invoked_With_Different_Arguments (N : Node_Id) return Boolean is
771 Subp : constant Entity_Id := Entity (Name (N));
777 -- Determine whether the formals of the invoked subprogram are not
778 -- used as actuals in the call.
780 Actual := First_Actual (Call);
781 Formal := First_Formal (Subp);
782 while Present (Actual) and then Present (Formal) loop
784 -- The current actual does not match the current formal
786 if not (Is_Entity_Name (Actual)
787 and then Entity (Actual) = Formal)
792 Next_Actual (Actual);
793 Next_Formal (Formal);
797 end Invoked_With_Different_Arguments;
799 ------------------------------
800 -- Is_Conditional_Statement --
801 ------------------------------
803 function Is_Conditional_Statement (N : Node_Id) return Boolean is
806 Nkind_In (N, N_And_Then,
812 end Is_Conditional_Statement;
814 -------------------------------
815 -- Is_Control_Flow_Statement --
816 -------------------------------
818 function Is_Control_Flow_Statement (N : Node_Id) return Boolean is
820 -- It is assumed that all statements may affect the control flow in
821 -- some way. A raise statement may be expanded into a non-statement
824 return Is_Statement (N) or else Is_Raise_Statement (N);
825 end Is_Control_Flow_Statement;
827 --------------------------------
828 -- Is_Immediately_Within_Body --
829 --------------------------------
831 function Is_Immediately_Within_Body (N : Node_Id) return Boolean is
832 HSS : constant Node_Id := Parent (N);
836 Nkind (HSS) = N_Handled_Sequence_Of_Statements
837 and then Nkind_In (Parent (HSS), N_Entry_Body, N_Subprogram_Body)
838 and then Is_List_Member (N)
839 and then List_Containing (N) = Statements (HSS);
840 end Is_Immediately_Within_Body;
846 function Is_Raise_Idiom (N : Node_Id) return Boolean is
847 Raise_Stmt : Node_Id;
851 if Is_Immediately_Within_Body (N) then
853 -- Assume that no raise statement has been seen yet
857 -- Examine the statements preceding the input node, skipping
858 -- internally-generated constructs.
861 while Present (Stmt) loop
863 -- Multiple raise statements violate the idiom
865 if Is_Raise_Statement (Stmt) then
866 if Present (Raise_Stmt) then
872 elsif Comes_From_Source (Stmt) then
879 -- At this point the node must be preceded by a raise statement,
880 -- and the raise statement has to be the sole statement within
881 -- the enclosing entry or subprogram body.
884 Present (Raise_Stmt) and then Is_Sole_Statement (Raise_Stmt);
890 ------------------------
891 -- Is_Raise_Statement --
892 ------------------------
894 function Is_Raise_Statement (N : Node_Id) return Boolean is
896 -- A raise statement may be transfomed into a Raise_xxx_Error node
899 Nkind (N) = N_Raise_Statement
900 or else Nkind (N) in N_Raise_xxx_Error;
901 end Is_Raise_Statement;
903 -----------------------
904 -- Is_Sole_Statement --
905 -----------------------
907 function Is_Sole_Statement (N : Node_Id) return Boolean is
911 -- The input node appears within the statements of an entry or
912 -- subprogram body. Examine the statements preceding the node.
914 if Is_Immediately_Within_Body (N) then
917 while Present (Stmt) loop
919 -- The statement is preceded by another statement or a source
920 -- construct. This indicates that the node does not appear by
923 if Is_Control_Flow_Statement (Stmt)
924 or else Comes_From_Source (Stmt)
935 -- The input node is within a construct nested inside the entry or
939 end Is_Sole_Statement;
941 ----------------------------------------
942 -- Preceded_By_Control_Flow_Statement --
943 ----------------------------------------
945 function Preceded_By_Control_Flow_Statement
946 (N : Node_Id) return Boolean
951 if Is_List_Member (N) then
954 -- Examine the statements preceding the input node
956 while Present (Stmt) loop
957 if Is_Control_Flow_Statement (Stmt) then
967 -- Assume that the node is part of some control flow statement
970 end Preceded_By_Control_Flow_Statement;
972 ----------------------------------
973 -- Within_Conditional_Statement --
974 ----------------------------------
976 function Within_Conditional_Statement (N : Node_Id) return Boolean is
981 while Present (Stmt) loop
982 if Is_Conditional_Statement (Stmt) then
985 -- Prevent the search from going too far
987 elsif Is_Body_Or_Package_Declaration (Stmt) then
991 Stmt := Parent (Stmt);
995 end Within_Conditional_Statement;
999 Call_Context : constant Node_Id :=
1000 Enclosing_Declaration_Or_Statement (Call);
1002 -- Start of processing for Check_Infinite_Recursion
1005 -- The call is assumed to be safe when the enclosing subprogram is
1006 -- invoked with actuals other than its formals.
1008 -- procedure Proc (F1 : ...; F2 : ...; ...; FN : ...) is
1011 -- Proc (A1, A2, ..., AN);
1015 if Invoked_With_Different_Arguments (Call) then
1018 -- The call is assumed to be safe when the invocation of the enclosing
1019 -- subprogram depends on a conditional statement.
1021 -- procedure Proc (F1 : ...; F2 : ...; ...; FN : ...) is
1024 -- if Some_Condition then
1025 -- Proc (F1, F2, ..., FN);
1030 elsif Within_Conditional_Statement (Call) then
1033 -- The context of the call is assumed to be safe when the invocation of
1034 -- the enclosing subprogram is preceded by some control flow statement.
1036 -- procedure Proc (F1 : ...; F2 : ...; ...; FN : ...) is
1039 -- if Some_Condition then
1043 -- Proc (F1, F2, ..., FN);
1047 elsif Preceded_By_Control_Flow_Statement (Call_Context) then
1050 -- Detect an idiom where the context of the call is preceded by a single
1053 -- procedure Proc (F1 : ...; F2 : ...; ...; FN : ...) is
1056 -- Proc (F1, F2, ..., FN);
1059 elsif Is_Raise_Idiom (Call_Context) then
1063 -- At this point it is certain that infinite recursion will take place
1064 -- as long as the call is executed. Detect a case where the context of
1065 -- the call is the sole source statement within the subprogram body.
1067 -- procedure Proc (F1 : ...; F2 : ...; ...; FN : ...) is
1069 -- Proc (F1, F2, ..., FN);
1072 -- Install an explicit raise to prevent the infinite recursion.
1074 if Is_Sole_Statement (Call_Context) then
1075 Error_Msg_Warn := SPARK_Mode /= On;
1076 Error_Msg_N ("!infinite recursion<<", Call);
1077 Error_Msg_N ("\!Storage_Error [<<", Call);
1079 Insert_Action (Call,
1080 Make_Raise_Storage_Error (Sloc (Call),
1081 Reason => SE_Infinite_Recursion));
1083 -- Otherwise infinite recursion could take place, considering other flow
1084 -- control constructs such as gotos, exit statements, etc.
1087 Error_Msg_Warn := SPARK_Mode /= On;
1088 Error_Msg_N ("!possible infinite recursion<<", Call);
1089 Error_Msg_N ("\!??Storage_Error ]<<", Call);
1093 end Check_Infinite_Recursion;
1095 ---------------------------------------
1096 -- Check_No_Direct_Boolean_Operators --
1097 ---------------------------------------
1099 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
1101 if Scope (Entity (N)) = Standard_Standard
1102 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
1104 -- Restriction only applies to original source code
1106 if Comes_From_Source (N) then
1107 Check_Restriction (No_Direct_Boolean_Operators, N);
1111 -- Do style check (but skip if in instance, error is on template)
1114 if not In_Instance then
1115 Check_Boolean_Operator (N);
1118 end Check_No_Direct_Boolean_Operators;
1120 ------------------------------
1121 -- Check_Parameterless_Call --
1122 ------------------------------
1124 procedure Check_Parameterless_Call (N : Node_Id) is
1127 function Prefix_Is_Access_Subp return Boolean;
1128 -- If the prefix is of an access_to_subprogram type, the node must be
1129 -- rewritten as a call. Ditto if the prefix is overloaded and all its
1130 -- interpretations are access to subprograms.
1132 ---------------------------
1133 -- Prefix_Is_Access_Subp --
1134 ---------------------------
1136 function Prefix_Is_Access_Subp return Boolean is
1141 -- If the context is an attribute reference that can apply to
1142 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1144 if Nkind (Parent (N)) = N_Attribute_Reference
1145 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1152 if not Is_Overloaded (N) then
1154 Ekind (Etype (N)) = E_Subprogram_Type
1155 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1157 Get_First_Interp (N, I, It);
1158 while Present (It.Typ) loop
1159 if Ekind (It.Typ) /= E_Subprogram_Type
1160 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1165 Get_Next_Interp (I, It);
1170 end Prefix_Is_Access_Subp;
1172 -- Start of processing for Check_Parameterless_Call
1175 -- Defend against junk stuff if errors already detected
1177 if Total_Errors_Detected /= 0 then
1178 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1180 elsif Nkind (N) in N_Has_Chars
1181 and then not Is_Valid_Name (Chars (N))
1189 -- If the context expects a value, and the name is a procedure, this is
1190 -- most likely a missing 'Access. Don't try to resolve the parameterless
1191 -- call, error will be caught when the outer call is analyzed.
1193 if Is_Entity_Name (N)
1194 and then Ekind (Entity (N)) = E_Procedure
1195 and then not Is_Overloaded (N)
1197 Nkind_In (Parent (N), N_Parameter_Association,
1199 N_Procedure_Call_Statement)
1204 -- Rewrite as call if overloadable entity that is (or could be, in the
1205 -- overloaded case) a function call. If we know for sure that the entity
1206 -- is an enumeration literal, we do not rewrite it.
1208 -- If the entity is the name of an operator, it cannot be a call because
1209 -- operators cannot have default parameters. In this case, this must be
1210 -- a string whose contents coincide with an operator name. Set the kind
1211 -- of the node appropriately.
1213 if (Is_Entity_Name (N)
1214 and then Nkind (N) /= N_Operator_Symbol
1215 and then Is_Overloadable (Entity (N))
1216 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1217 or else Is_Overloaded (N)))
1219 -- Rewrite as call if it is an explicit dereference of an expression of
1220 -- a subprogram access type, and the subprogram type is not that of a
1221 -- procedure or entry.
1224 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1226 -- Rewrite as call if it is a selected component which is a function,
1227 -- this is the case of a call to a protected function (which may be
1228 -- overloaded with other protected operations).
1231 (Nkind (N) = N_Selected_Component
1232 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1234 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1236 and then Is_Overloaded (Selector_Name (N)))))
1238 -- If one of the above three conditions is met, rewrite as call. Apply
1239 -- the rewriting only once.
1242 if Nkind (Parent (N)) /= N_Function_Call
1243 or else N /= Name (Parent (N))
1246 -- This may be a prefixed call that was not fully analyzed, e.g.
1247 -- an actual in an instance.
1249 if Ada_Version >= Ada_2005
1250 and then Nkind (N) = N_Selected_Component
1251 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1253 Analyze_Selected_Component (N);
1255 if Nkind (N) /= N_Selected_Component then
1260 -- The node is the name of the parameterless call. Preserve its
1261 -- descendants, which may be complex expressions.
1263 Nam := Relocate_Node (N);
1265 -- If overloaded, overload set belongs to new copy
1267 Save_Interps (N, Nam);
1269 -- Change node to parameterless function call (note that the
1270 -- Parameter_Associations associations field is left set to Empty,
1271 -- its normal default value since there are no parameters)
1273 Change_Node (N, N_Function_Call);
1275 Set_Sloc (N, Sloc (Nam));
1279 elsif Nkind (N) = N_Parameter_Association then
1280 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1282 elsif Nkind (N) = N_Operator_Symbol then
1283 Change_Operator_Symbol_To_String_Literal (N);
1284 Set_Is_Overloaded (N, False);
1285 Set_Etype (N, Any_String);
1287 end Check_Parameterless_Call;
1289 --------------------------------
1290 -- Is_Atomic_Ref_With_Address --
1291 --------------------------------
1293 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1294 Pref : constant Node_Id := Prefix (N);
1297 if not Is_Entity_Name (Pref) then
1302 Pent : constant Entity_Id := Entity (Pref);
1303 Ptyp : constant Entity_Id := Etype (Pent);
1305 return not Is_Access_Type (Ptyp)
1306 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1307 and then Present (Address_Clause (Pent));
1310 end Is_Atomic_Ref_With_Address;
1312 -----------------------------
1313 -- Is_Definite_Access_Type --
1314 -----------------------------
1316 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1317 Btyp : constant Entity_Id := Base_Type (E);
1319 return Ekind (Btyp) = E_Access_Type
1320 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1321 and then Comes_From_Source (Btyp));
1322 end Is_Definite_Access_Type;
1324 ----------------------
1325 -- Is_Predefined_Op --
1326 ----------------------
1328 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1330 -- Predefined operators are intrinsic subprograms
1332 if not Is_Intrinsic_Subprogram (Nam) then
1336 -- A call to a back-end builtin is never a predefined operator
1338 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1342 return not Is_Generic_Instance (Nam)
1343 and then Chars (Nam) in Any_Operator_Name
1344 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1345 end Is_Predefined_Op;
1347 -----------------------------
1348 -- Make_Call_Into_Operator --
1349 -----------------------------
1351 procedure Make_Call_Into_Operator
1356 Op_Name : constant Name_Id := Chars (Op_Id);
1357 Act1 : Node_Id := First_Actual (N);
1358 Act2 : Node_Id := Next_Actual (Act1);
1359 Error : Boolean := False;
1360 Func : constant Entity_Id := Entity (Name (N));
1361 Is_Binary : constant Boolean := Present (Act2);
1363 Opnd_Type : Entity_Id := Empty;
1364 Orig_Type : Entity_Id := Empty;
1367 type Kind_Test is access function (E : Entity_Id) return Boolean;
1369 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1370 -- If the operand is not universal, and the operator is given by an
1371 -- expanded name, verify that the operand has an interpretation with a
1372 -- type defined in the given scope of the operator.
1374 function Type_In_P (Test : Kind_Test) return Entity_Id;
1375 -- Find a type of the given class in package Pack that contains the
1378 ---------------------------
1379 -- Operand_Type_In_Scope --
1380 ---------------------------
1382 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1383 Nod : constant Node_Id := Right_Opnd (Op_Node);
1388 if not Is_Overloaded (Nod) then
1389 return Scope (Base_Type (Etype (Nod))) = S;
1392 Get_First_Interp (Nod, I, It);
1393 while Present (It.Typ) loop
1394 if Scope (Base_Type (It.Typ)) = S then
1398 Get_Next_Interp (I, It);
1403 end Operand_Type_In_Scope;
1409 function Type_In_P (Test : Kind_Test) return Entity_Id is
1412 function In_Decl return Boolean;
1413 -- Verify that node is not part of the type declaration for the
1414 -- candidate type, which would otherwise be invisible.
1420 function In_Decl return Boolean is
1421 Decl_Node : constant Node_Id := Parent (E);
1427 if Etype (E) = Any_Type then
1430 elsif No (Decl_Node) then
1435 and then Nkind (N2) /= N_Compilation_Unit
1437 if N2 = Decl_Node then
1448 -- Start of processing for Type_In_P
1451 -- If the context type is declared in the prefix package, this is the
1452 -- desired base type.
1454 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1455 return Base_Type (Typ);
1458 E := First_Entity (Pack);
1459 while Present (E) loop
1460 if Test (E) and then not In_Decl then
1471 -- Start of processing for Make_Call_Into_Operator
1474 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1476 -- Ensure that the corresponding operator has the same parent as the
1477 -- original call. This guarantees that parent traversals performed by
1478 -- the ABE mechanism succeed.
1480 Set_Parent (Op_Node, Parent (N));
1485 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1486 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1487 Save_Interps (Act1, Left_Opnd (Op_Node));
1488 Save_Interps (Act2, Right_Opnd (Op_Node));
1489 Act1 := Left_Opnd (Op_Node);
1490 Act2 := Right_Opnd (Op_Node);
1495 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1496 Save_Interps (Act1, Right_Opnd (Op_Node));
1497 Act1 := Right_Opnd (Op_Node);
1500 -- If the operator is denoted by an expanded name, and the prefix is
1501 -- not Standard, but the operator is a predefined one whose scope is
1502 -- Standard, then this is an implicit_operator, inserted as an
1503 -- interpretation by the procedure of the same name. This procedure
1504 -- overestimates the presence of implicit operators, because it does
1505 -- not examine the type of the operands. Verify now that the operand
1506 -- type appears in the given scope. If right operand is universal,
1507 -- check the other operand. In the case of concatenation, either
1508 -- argument can be the component type, so check the type of the result.
1509 -- If both arguments are literals, look for a type of the right kind
1510 -- defined in the given scope. This elaborate nonsense is brought to
1511 -- you courtesy of b33302a. The type itself must be frozen, so we must
1512 -- find the type of the proper class in the given scope.
1514 -- A final wrinkle is the multiplication operator for fixed point types,
1515 -- which is defined in Standard only, and not in the scope of the
1516 -- fixed point type itself.
1518 if Nkind (Name (N)) = N_Expanded_Name then
1519 Pack := Entity (Prefix (Name (N)));
1521 -- If this is a package renaming, get renamed entity, which will be
1522 -- the scope of the operands if operaton is type-correct.
1524 if Present (Renamed_Entity (Pack)) then
1525 Pack := Renamed_Entity (Pack);
1528 -- If the entity being called is defined in the given package, it is
1529 -- a renaming of a predefined operator, and known to be legal.
1531 if Scope (Entity (Name (N))) = Pack
1532 and then Pack /= Standard_Standard
1536 -- Visibility does not need to be checked in an instance: if the
1537 -- operator was not visible in the generic it has been diagnosed
1538 -- already, else there is an implicit copy of it in the instance.
1540 elsif In_Instance then
1543 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1544 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1545 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1547 if Pack /= Standard_Standard then
1551 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1554 elsif Ada_Version >= Ada_2005
1555 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1556 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1561 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1563 if Op_Name = Name_Op_Concat then
1564 Opnd_Type := Base_Type (Typ);
1566 elsif (Scope (Opnd_Type) = Standard_Standard
1568 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1570 and then not Comes_From_Source (Opnd_Type))
1572 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1575 if Scope (Opnd_Type) = Standard_Standard then
1577 -- Verify that the scope contains a type that corresponds to
1578 -- the given literal. Optimize the case where Pack is Standard.
1580 if Pack /= Standard_Standard then
1581 if Opnd_Type = Universal_Integer then
1582 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1584 elsif Opnd_Type = Universal_Real then
1585 Orig_Type := Type_In_P (Is_Real_Type'Access);
1587 elsif Opnd_Type = Any_String then
1588 Orig_Type := Type_In_P (Is_String_Type'Access);
1590 elsif Opnd_Type = Any_Access then
1591 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1593 elsif Opnd_Type = Any_Composite then
1594 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1596 if Present (Orig_Type) then
1597 if Has_Private_Component (Orig_Type) then
1600 Set_Etype (Act1, Orig_Type);
1603 Set_Etype (Act2, Orig_Type);
1612 Error := No (Orig_Type);
1615 elsif Ekind (Opnd_Type) = E_Allocator_Type
1616 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1620 -- If the type is defined elsewhere, and the operator is not
1621 -- defined in the given scope (by a renaming declaration, e.g.)
1622 -- then this is an error as well. If an extension of System is
1623 -- present, and the type may be defined there, Pack must be
1626 elsif Scope (Opnd_Type) /= Pack
1627 and then Scope (Op_Id) /= Pack
1628 and then (No (System_Aux_Id)
1629 or else Scope (Opnd_Type) /= System_Aux_Id
1630 or else Pack /= Scope (System_Aux_Id))
1632 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1635 Error := not Operand_Type_In_Scope (Pack);
1638 elsif Pack = Standard_Standard
1639 and then not Operand_Type_In_Scope (Standard_Standard)
1646 Error_Msg_Node_2 := Pack;
1648 ("& not declared in&", N, Selector_Name (Name (N)));
1649 Set_Etype (N, Any_Type);
1652 -- Detect a mismatch between the context type and the result type
1653 -- in the named package, which is otherwise not detected if the
1654 -- operands are universal. Check is only needed if source entity is
1655 -- an operator, not a function that renames an operator.
1657 elsif Nkind (Parent (N)) /= N_Type_Conversion
1658 and then Ekind (Entity (Name (N))) = E_Operator
1659 and then Is_Numeric_Type (Typ)
1660 and then not Is_Universal_Numeric_Type (Typ)
1661 and then Scope (Base_Type (Typ)) /= Pack
1662 and then not In_Instance
1664 if Is_Fixed_Point_Type (Typ)
1665 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1667 -- Already checked above
1671 -- Operator may be defined in an extension of System
1673 elsif Present (System_Aux_Id)
1674 and then Present (Opnd_Type)
1675 and then Scope (Opnd_Type) = System_Aux_Id
1680 -- Could we use Wrong_Type here??? (this would require setting
1681 -- Etype (N) to the actual type found where Typ was expected).
1683 Error_Msg_NE ("expect }", N, Typ);
1688 Set_Chars (Op_Node, Op_Name);
1690 if not Is_Private_Type (Etype (N)) then
1691 Set_Etype (Op_Node, Base_Type (Etype (N)));
1693 Set_Etype (Op_Node, Etype (N));
1696 -- If this is a call to a function that renames a predefined equality,
1697 -- the renaming declaration provides a type that must be used to
1698 -- resolve the operands. This must be done now because resolution of
1699 -- the equality node will not resolve any remaining ambiguity, and it
1700 -- assumes that the first operand is not overloaded.
1702 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1703 and then Ekind (Func) = E_Function
1704 and then Is_Overloaded (Act1)
1706 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1707 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1710 Set_Entity (Op_Node, Op_Id);
1711 Generate_Reference (Op_Id, N, ' ');
1713 -- Do rewrite setting Comes_From_Source on the result if the original
1714 -- call came from source. Although it is not strictly the case that the
1715 -- operator as such comes from the source, logically it corresponds
1716 -- exactly to the function call in the source, so it should be marked
1717 -- this way (e.g. to make sure that validity checks work fine).
1720 CS : constant Boolean := Comes_From_Source (N);
1722 Rewrite (N, Op_Node);
1723 Set_Comes_From_Source (N, CS);
1726 -- If this is an arithmetic operator and the result type is private,
1727 -- the operands and the result must be wrapped in conversion to
1728 -- expose the underlying numeric type and expand the proper checks,
1729 -- e.g. on division.
1731 if Is_Private_Type (Typ) then
1741 Resolve_Intrinsic_Operator (N, Typ);
1747 Resolve_Intrinsic_Unary_Operator (N, Typ);
1756 -- If in ASIS_Mode, propagate operand types to original actuals of
1757 -- function call, which would otherwise not be fully resolved. If
1758 -- the call has already been constant-folded, nothing to do. We
1759 -- relocate the operand nodes rather than copy them, to preserve
1760 -- original_node pointers, given that the operands themselves may
1761 -- have been rewritten. If the call was itself a rewriting of an
1762 -- operator node, nothing to do.
1765 and then Nkind (N) in N_Op
1766 and then Nkind (Original_Node (N)) = N_Function_Call
1770 R : constant Node_Id := Right_Opnd (N);
1772 Old_First : constant Node_Id :=
1773 First (Parameter_Associations (Original_Node (N)));
1779 Old_Sec := Next (Old_First);
1781 -- If the original call has named associations, replace the
1782 -- explicit actual parameter in the association with the proper
1783 -- resolved operand.
1785 if Nkind (Old_First) = N_Parameter_Association then
1786 if Chars (Selector_Name (Old_First)) =
1787 Chars (First_Entity (Op_Id))
1789 Rewrite (Explicit_Actual_Parameter (Old_First),
1792 Rewrite (Explicit_Actual_Parameter (Old_First),
1797 Rewrite (Old_First, Relocate_Node (L));
1800 if Nkind (Old_Sec) = N_Parameter_Association then
1801 if Chars (Selector_Name (Old_Sec)) =
1802 Chars (First_Entity (Op_Id))
1804 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1807 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1812 Rewrite (Old_Sec, Relocate_Node (R));
1816 if Nkind (Old_First) = N_Parameter_Association then
1817 Rewrite (Explicit_Actual_Parameter (Old_First),
1820 Rewrite (Old_First, Relocate_Node (R));
1825 Set_Parent (Original_Node (N), Parent (N));
1827 end Make_Call_Into_Operator;
1833 function Operator_Kind
1835 Is_Binary : Boolean) return Node_Kind
1840 -- Use CASE statement or array???
1843 if Op_Name = Name_Op_And then
1845 elsif Op_Name = Name_Op_Or then
1847 elsif Op_Name = Name_Op_Xor then
1849 elsif Op_Name = Name_Op_Eq then
1851 elsif Op_Name = Name_Op_Ne then
1853 elsif Op_Name = Name_Op_Lt then
1855 elsif Op_Name = Name_Op_Le then
1857 elsif Op_Name = Name_Op_Gt then
1859 elsif Op_Name = Name_Op_Ge then
1861 elsif Op_Name = Name_Op_Add then
1863 elsif Op_Name = Name_Op_Subtract then
1864 Kind := N_Op_Subtract;
1865 elsif Op_Name = Name_Op_Concat then
1866 Kind := N_Op_Concat;
1867 elsif Op_Name = Name_Op_Multiply then
1868 Kind := N_Op_Multiply;
1869 elsif Op_Name = Name_Op_Divide then
1870 Kind := N_Op_Divide;
1871 elsif Op_Name = Name_Op_Mod then
1873 elsif Op_Name = Name_Op_Rem then
1875 elsif Op_Name = Name_Op_Expon then
1878 raise Program_Error;
1884 if Op_Name = Name_Op_Add then
1886 elsif Op_Name = Name_Op_Subtract then
1888 elsif Op_Name = Name_Op_Abs then
1890 elsif Op_Name = Name_Op_Not then
1893 raise Program_Error;
1900 ----------------------------
1901 -- Preanalyze_And_Resolve --
1902 ----------------------------
1904 procedure Preanalyze_And_Resolve
1907 With_Freezing : Boolean)
1909 Save_Full_Analysis : constant Boolean := Full_Analysis;
1910 Save_Must_Not_Freeze : constant Boolean := Must_Not_Freeze (N);
1911 Save_Preanalysis_Count : constant Nat :=
1912 Inside_Preanalysis_Without_Freezing;
1914 pragma Assert (Nkind (N) in N_Subexpr);
1916 if not With_Freezing then
1917 Set_Must_Not_Freeze (N);
1918 Inside_Preanalysis_Without_Freezing :=
1919 Inside_Preanalysis_Without_Freezing + 1;
1922 Full_Analysis := False;
1923 Expander_Mode_Save_And_Set (False);
1925 -- Normally, we suppress all checks for this preanalysis. There is no
1926 -- point in processing them now, since they will be applied properly
1927 -- and in the proper location when the default expressions reanalyzed
1928 -- and reexpanded later on. We will also have more information at that
1929 -- point for possible suppression of individual checks.
1931 -- However, in SPARK mode, most expansion is suppressed, and this
1932 -- later reanalysis and reexpansion may not occur. SPARK mode does
1933 -- require the setting of checking flags for proof purposes, so we
1934 -- do the SPARK preanalysis without suppressing checks.
1936 -- This special handling for SPARK mode is required for example in the
1937 -- case of Ada 2012 constructs such as quantified expressions, which are
1938 -- expanded in two separate steps.
1940 if GNATprove_Mode then
1941 Analyze_And_Resolve (N, T);
1943 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1946 Expander_Mode_Restore;
1947 Full_Analysis := Save_Full_Analysis;
1948 Set_Must_Not_Freeze (N, Save_Must_Not_Freeze);
1950 if not With_Freezing then
1951 Inside_Preanalysis_Without_Freezing :=
1952 Inside_Preanalysis_Without_Freezing - 1;
1956 (Inside_Preanalysis_Without_Freezing = Save_Preanalysis_Count);
1957 end Preanalyze_And_Resolve;
1959 ----------------------------
1960 -- Preanalyze_And_Resolve --
1961 ----------------------------
1963 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1965 Preanalyze_And_Resolve (N, T, With_Freezing => False);
1966 end Preanalyze_And_Resolve;
1968 -- Version without context type
1970 procedure Preanalyze_And_Resolve (N : Node_Id) is
1971 Save_Full_Analysis : constant Boolean := Full_Analysis;
1974 Full_Analysis := False;
1975 Expander_Mode_Save_And_Set (False);
1978 Resolve (N, Etype (N), Suppress => All_Checks);
1980 Expander_Mode_Restore;
1981 Full_Analysis := Save_Full_Analysis;
1982 end Preanalyze_And_Resolve;
1984 ------------------------------------------
1985 -- Preanalyze_With_Freezing_And_Resolve --
1986 ------------------------------------------
1988 procedure Preanalyze_With_Freezing_And_Resolve
1993 Preanalyze_And_Resolve (N, T, With_Freezing => True);
1994 end Preanalyze_With_Freezing_And_Resolve;
1996 ----------------------------------
1997 -- Replace_Actual_Discriminants --
1998 ----------------------------------
2000 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
2001 Loc : constant Source_Ptr := Sloc (N);
2002 Tsk : Node_Id := Empty;
2004 function Process_Discr (Nod : Node_Id) return Traverse_Result;
2005 -- Comment needed???
2011 function Process_Discr (Nod : Node_Id) return Traverse_Result is
2015 if Nkind (Nod) = N_Identifier then
2016 Ent := Entity (Nod);
2019 and then Ekind (Ent) = E_Discriminant
2022 Make_Selected_Component (Loc,
2023 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
2024 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
2026 Set_Etype (Nod, Etype (Ent));
2034 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
2036 -- Start of processing for Replace_Actual_Discriminants
2039 if Expander_Active then
2042 -- Allow the replacement of concurrent discriminants in GNATprove even
2043 -- though this is a light expansion activity. Note that generic units
2044 -- are not modified.
2046 elsif GNATprove_Mode and not Inside_A_Generic then
2053 if Nkind (Name (N)) = N_Selected_Component then
2054 Tsk := Prefix (Name (N));
2056 elsif Nkind (Name (N)) = N_Indexed_Component then
2057 Tsk := Prefix (Prefix (Name (N)));
2060 if Present (Tsk) then
2061 Replace_Discrs (Default);
2063 end Replace_Actual_Discriminants;
2069 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
2070 Ambiguous : Boolean := False;
2071 Ctx_Type : Entity_Id := Typ;
2072 Expr_Type : Entity_Id := Empty; -- prevent junk warning
2073 Err_Type : Entity_Id := Empty;
2074 Found : Boolean := False;
2077 I1 : Interp_Index := 0; -- prevent junk warning
2080 Seen : Entity_Id := Empty; -- prevent junk warning
2082 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
2083 -- Determine whether a node comes from a predefined library unit or
2086 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
2087 -- Try and fix up a literal so that it matches its expected type. New
2088 -- literals are manufactured if necessary to avoid cascaded errors.
2090 procedure Report_Ambiguous_Argument;
2091 -- Additional diagnostics when an ambiguous call has an ambiguous
2092 -- argument (typically a controlling actual).
2094 procedure Resolution_Failed;
2095 -- Called when attempt at resolving current expression fails
2097 ------------------------------------
2098 -- Comes_From_Predefined_Lib_Unit --
2099 -------------------------------------
2101 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
2104 Sloc (Nod) = Standard_Location or else In_Predefined_Unit (Nod);
2105 end Comes_From_Predefined_Lib_Unit;
2107 --------------------
2108 -- Patch_Up_Value --
2109 --------------------
2111 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
2113 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
2115 Make_Real_Literal (Sloc (N),
2116 Realval => UR_From_Uint (Intval (N))));
2117 Set_Etype (N, Universal_Real);
2118 Set_Is_Static_Expression (N);
2120 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
2122 Make_Integer_Literal (Sloc (N),
2123 Intval => UR_To_Uint (Realval (N))));
2124 Set_Etype (N, Universal_Integer);
2125 Set_Is_Static_Expression (N);
2127 elsif Nkind (N) = N_String_Literal
2128 and then Is_Character_Type (Typ)
2130 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
2132 Make_Character_Literal (Sloc (N),
2134 Char_Literal_Value =>
2135 UI_From_Int (Character'Pos ('A'))));
2136 Set_Etype (N, Any_Character);
2137 Set_Is_Static_Expression (N);
2139 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
2141 Make_String_Literal (Sloc (N),
2142 Strval => End_String));
2144 elsif Nkind (N) = N_Range then
2145 Patch_Up_Value (Low_Bound (N), Typ);
2146 Patch_Up_Value (High_Bound (N), Typ);
2150 -------------------------------
2151 -- Report_Ambiguous_Argument --
2152 -------------------------------
2154 procedure Report_Ambiguous_Argument is
2155 Arg : constant Node_Id := First (Parameter_Associations (N));
2160 if Nkind (Arg) = N_Function_Call
2161 and then Is_Entity_Name (Name (Arg))
2162 and then Is_Overloaded (Name (Arg))
2164 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
2166 -- Could use comments on what is going on here???
2168 Get_First_Interp (Name (Arg), I, It);
2169 while Present (It.Nam) loop
2170 Error_Msg_Sloc := Sloc (It.Nam);
2172 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
2173 Error_Msg_N ("interpretation (inherited) #!", Arg);
2175 Error_Msg_N ("interpretation #!", Arg);
2178 Get_Next_Interp (I, It);
2181 end Report_Ambiguous_Argument;
2183 -----------------------
2184 -- Resolution_Failed --
2185 -----------------------
2187 procedure Resolution_Failed is
2189 Patch_Up_Value (N, Typ);
2191 -- Set the type to the desired one to minimize cascaded errors. Note
2192 -- that this is an approximation and does not work in all cases.
2196 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
2197 Set_Is_Overloaded (N, False);
2199 -- The caller will return without calling the expander, so we need
2200 -- to set the analyzed flag. Note that it is fine to set Analyzed
2201 -- to True even if we are in the middle of a shallow analysis,
2202 -- (see the spec of sem for more details) since this is an error
2203 -- situation anyway, and there is no point in repeating the
2204 -- analysis later (indeed it won't work to repeat it later, since
2205 -- we haven't got a clear resolution of which entity is being
2208 Set_Analyzed (N, True);
2210 end Resolution_Failed;
2212 -- Start of processing for Resolve
2219 -- Access attribute on remote subprogram cannot be used for a non-remote
2220 -- access-to-subprogram type.
2222 if Nkind (N) = N_Attribute_Reference
2223 and then Nam_In (Attribute_Name (N), Name_Access,
2224 Name_Unrestricted_Access,
2225 Name_Unchecked_Access)
2226 and then Comes_From_Source (N)
2227 and then Is_Entity_Name (Prefix (N))
2228 and then Is_Subprogram (Entity (Prefix (N)))
2229 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2230 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2233 ("prefix must statically denote a non-remote subprogram", N);
2236 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2238 -- If the context is a Remote_Access_To_Subprogram, access attributes
2239 -- must be resolved with the corresponding fat pointer. There is no need
2240 -- to check for the attribute name since the return type of an
2241 -- attribute is never a remote type.
2243 if Nkind (N) = N_Attribute_Reference
2244 and then Comes_From_Source (N)
2245 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2248 Attr : constant Attribute_Id :=
2249 Get_Attribute_Id (Attribute_Name (N));
2250 Pref : constant Node_Id := Prefix (N);
2253 Is_Remote : Boolean := True;
2256 -- Check that Typ is a remote access-to-subprogram type
2258 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2260 -- Prefix (N) must statically denote a remote subprogram
2261 -- declared in a package specification.
2263 if Attr = Attribute_Access or else
2264 Attr = Attribute_Unchecked_Access or else
2265 Attr = Attribute_Unrestricted_Access
2267 Decl := Unit_Declaration_Node (Entity (Pref));
2269 if Nkind (Decl) = N_Subprogram_Body then
2270 Spec := Corresponding_Spec (Decl);
2272 if Present (Spec) then
2273 Decl := Unit_Declaration_Node (Spec);
2277 Spec := Parent (Decl);
2279 if not Is_Entity_Name (Prefix (N))
2280 or else Nkind (Spec) /= N_Package_Specification
2282 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2286 ("prefix must statically denote a remote subprogram ",
2290 -- If we are generating code in distributed mode, perform
2291 -- semantic checks against corresponding remote entities.
2294 and then Get_PCS_Name /= Name_No_DSA
2296 Check_Subtype_Conformant
2297 (New_Id => Entity (Prefix (N)),
2298 Old_Id => Designated_Type
2299 (Corresponding_Remote_Type (Typ)),
2303 Process_Remote_AST_Attribute (N, Typ);
2311 Debug_A_Entry ("resolving ", N);
2313 if Debug_Flag_V then
2314 Write_Overloads (N);
2317 if Comes_From_Source (N) then
2318 if Is_Fixed_Point_Type (Typ) then
2319 Check_Restriction (No_Fixed_Point, N);
2321 elsif Is_Floating_Point_Type (Typ)
2322 and then Typ /= Universal_Real
2323 and then Typ /= Any_Real
2325 Check_Restriction (No_Floating_Point, N);
2329 -- Return if already analyzed
2331 if Analyzed (N) then
2332 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2333 Analyze_Dimension (N);
2336 -- Any case of Any_Type as the Etype value means that we had a
2339 elsif Etype (N) = Any_Type then
2340 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2344 Check_Parameterless_Call (N);
2346 -- The resolution of an Expression_With_Actions is determined by
2349 if Nkind (N) = N_Expression_With_Actions then
2350 Resolve (Expression (N), Typ);
2353 Expr_Type := Etype (Expression (N));
2355 -- If not overloaded, then we know the type, and all that needs doing
2356 -- is to check that this type is compatible with the context.
2358 elsif not Is_Overloaded (N) then
2359 Found := Covers (Typ, Etype (N));
2360 Expr_Type := Etype (N);
2362 -- In the overloaded case, we must select the interpretation that
2363 -- is compatible with the context (i.e. the type passed to Resolve)
2366 -- Loop through possible interpretations
2368 Get_First_Interp (N, I, It);
2369 Interp_Loop : while Present (It.Typ) loop
2370 if Debug_Flag_V then
2371 Write_Str ("Interp: ");
2375 -- We are only interested in interpretations that are compatible
2376 -- with the expected type, any other interpretations are ignored.
2378 if not Covers (Typ, It.Typ) then
2379 if Debug_Flag_V then
2380 Write_Str (" interpretation incompatible with context");
2385 -- Skip the current interpretation if it is disabled by an
2386 -- abstract operator. This action is performed only when the
2387 -- type against which we are resolving is the same as the
2388 -- type of the interpretation.
2390 if Ada_Version >= Ada_2005
2391 and then It.Typ = Typ
2392 and then Typ /= Universal_Integer
2393 and then Typ /= Universal_Real
2394 and then Present (It.Abstract_Op)
2396 if Debug_Flag_V then
2397 Write_Line ("Skip.");
2403 -- First matching interpretation
2409 Expr_Type := It.Typ;
2411 -- Matching interpretation that is not the first, maybe an
2412 -- error, but there are some cases where preference rules are
2413 -- used to choose between the two possibilities. These and
2414 -- some more obscure cases are handled in Disambiguate.
2417 -- If the current statement is part of a predefined library
2418 -- unit, then all interpretations which come from user level
2419 -- packages should not be considered. Check previous and
2423 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2426 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2428 -- Previous interpretation must be discarded
2432 Expr_Type := It.Typ;
2433 Set_Entity (N, Seen);
2438 -- Otherwise apply further disambiguation steps
2440 Error_Msg_Sloc := Sloc (Seen);
2441 It1 := Disambiguate (N, I1, I, Typ);
2443 -- Disambiguation has succeeded. Skip the remaining
2446 if It1 /= No_Interp then
2448 Expr_Type := It1.Typ;
2450 while Present (It.Typ) loop
2451 Get_Next_Interp (I, It);
2455 -- Before we issue an ambiguity complaint, check for the
2456 -- case of a subprogram call where at least one of the
2457 -- arguments is Any_Type, and if so suppress the message,
2458 -- since it is a cascaded error. This can also happen for
2459 -- a generalized indexing operation.
2461 if Nkind (N) in N_Subprogram_Call
2462 or else (Nkind (N) = N_Indexed_Component
2463 and then Present (Generalized_Indexing (N)))
2470 if Nkind (N) = N_Indexed_Component then
2471 Rewrite (N, Generalized_Indexing (N));
2474 A := First_Actual (N);
2475 while Present (A) loop
2478 if Nkind (E) = N_Parameter_Association then
2479 E := Explicit_Actual_Parameter (E);
2482 if Etype (E) = Any_Type then
2483 if Debug_Flag_V then
2484 Write_Str ("Any_Type in call");
2495 elsif Nkind (N) in N_Binary_Op
2496 and then (Etype (Left_Opnd (N)) = Any_Type
2497 or else Etype (Right_Opnd (N)) = Any_Type)
2501 elsif Nkind (N) in N_Unary_Op
2502 and then Etype (Right_Opnd (N)) = Any_Type
2507 -- Not that special case, so issue message using the flag
2508 -- Ambiguous to control printing of the header message
2509 -- only at the start of an ambiguous set.
2511 if not Ambiguous then
2512 if Nkind (N) = N_Function_Call
2513 and then Nkind (Name (N)) = N_Explicit_Dereference
2516 ("ambiguous expression (cannot resolve indirect "
2519 Error_Msg_NE -- CODEFIX
2520 ("ambiguous expression (cannot resolve&)!",
2526 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2528 ("\\possible interpretation (inherited)#!", N);
2530 Error_Msg_N -- CODEFIX
2531 ("\\possible interpretation#!", N);
2534 if Nkind (N) in N_Subprogram_Call
2535 and then Present (Parameter_Associations (N))
2537 Report_Ambiguous_Argument;
2541 Error_Msg_Sloc := Sloc (It.Nam);
2543 -- By default, the error message refers to the candidate
2544 -- interpretation. But if it is a predefined operator, it
2545 -- is implicitly declared at the declaration of the type
2546 -- of the operand. Recover the sloc of that declaration
2547 -- for the error message.
2549 if Nkind (N) in N_Op
2550 and then Scope (It.Nam) = Standard_Standard
2551 and then not Is_Overloaded (Right_Opnd (N))
2552 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2555 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2557 if Comes_From_Source (Err_Type)
2558 and then Present (Parent (Err_Type))
2560 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2563 elsif Nkind (N) in N_Binary_Op
2564 and then Scope (It.Nam) = Standard_Standard
2565 and then not Is_Overloaded (Left_Opnd (N))
2566 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2569 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2571 if Comes_From_Source (Err_Type)
2572 and then Present (Parent (Err_Type))
2574 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2577 -- If this is an indirect call, use the subprogram_type
2578 -- in the message, to have a meaningful location. Also
2579 -- indicate if this is an inherited operation, created
2580 -- by a type declaration.
2582 elsif Nkind (N) = N_Function_Call
2583 and then Nkind (Name (N)) = N_Explicit_Dereference
2584 and then Is_Type (It.Nam)
2588 Sloc (Associated_Node_For_Itype (Err_Type));
2593 if Nkind (N) in N_Op
2594 and then Scope (It.Nam) = Standard_Standard
2595 and then Present (Err_Type)
2597 -- Special-case the message for universal_fixed
2598 -- operators, which are not declared with the type
2599 -- of the operand, but appear forever in Standard.
2601 if It.Typ = Universal_Fixed
2602 and then Scope (It.Nam) = Standard_Standard
2605 ("\\possible interpretation as universal_fixed "
2606 & "operation (RM 4.5.5 (19))", N);
2609 ("\\possible interpretation (predefined)#!", N);
2613 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2616 ("\\possible interpretation (inherited)#!", N);
2618 Error_Msg_N -- CODEFIX
2619 ("\\possible interpretation#!", N);
2625 -- We have a matching interpretation, Expr_Type is the type
2626 -- from this interpretation, and Seen is the entity.
2628 -- For an operator, just set the entity name. The type will be
2629 -- set by the specific operator resolution routine.
2631 if Nkind (N) in N_Op then
2632 Set_Entity (N, Seen);
2633 Generate_Reference (Seen, N);
2635 elsif Nkind_In (N, N_Case_Expression,
2636 N_Character_Literal,
2640 Set_Etype (N, Expr_Type);
2642 -- AI05-0139-2: Expression is overloaded because type has
2643 -- implicit dereference. The context may be the one that
2644 -- requires implicit dereferemce.
2646 elsif Has_Implicit_Dereference (Expr_Type) then
2647 Set_Etype (N, Expr_Type);
2648 Set_Is_Overloaded (N, False);
2650 -- If the expression is an entity, generate a reference
2651 -- to it, as this is not done for an overloaded construct
2654 if Is_Entity_Name (N)
2655 and then Comes_From_Source (N)
2657 Generate_Reference (Entity (N), N);
2659 -- Examine access discriminants of entity type,
2660 -- to check whether one of them yields the
2665 First_Discriminant (Etype (Entity (N)));
2668 while Present (Disc) loop
2669 exit when Is_Access_Type (Etype (Disc))
2670 and then Has_Implicit_Dereference (Disc)
2671 and then Designated_Type (Etype (Disc)) = Typ;
2673 Next_Discriminant (Disc);
2676 if Present (Disc) then
2677 Build_Explicit_Dereference (N, Disc);
2684 elsif Is_Overloaded (N)
2685 and then Present (It.Nam)
2686 and then Ekind (It.Nam) = E_Discriminant
2687 and then Has_Implicit_Dereference (It.Nam)
2689 -- If the node is a general indexing, the dereference is
2690 -- is inserted when resolving the rewritten form, else
2693 if Nkind (N) /= N_Indexed_Component
2694 or else No (Generalized_Indexing (N))
2696 Build_Explicit_Dereference (N, It.Nam);
2699 -- For an explicit dereference, attribute reference, range,
2700 -- short-circuit form (which is not an operator node), or call
2701 -- with a name that is an explicit dereference, there is
2702 -- nothing to be done at this point.
2704 elsif Nkind_In (N, N_Attribute_Reference,
2706 N_Explicit_Dereference,
2708 N_Indexed_Component,
2711 N_Selected_Component,
2713 or else Nkind (Name (N)) = N_Explicit_Dereference
2717 -- For procedure or function calls, set the type of the name,
2718 -- and also the entity pointer for the prefix.
2720 elsif Nkind (N) in N_Subprogram_Call
2721 and then Is_Entity_Name (Name (N))
2723 Set_Etype (Name (N), Expr_Type);
2724 Set_Entity (Name (N), Seen);
2725 Generate_Reference (Seen, Name (N));
2727 elsif Nkind (N) = N_Function_Call
2728 and then Nkind (Name (N)) = N_Selected_Component
2730 Set_Etype (Name (N), Expr_Type);
2731 Set_Entity (Selector_Name (Name (N)), Seen);
2732 Generate_Reference (Seen, Selector_Name (Name (N)));
2734 -- For all other cases, just set the type of the Name
2737 Set_Etype (Name (N), Expr_Type);
2744 -- Move to next interpretation
2746 exit Interp_Loop when No (It.Typ);
2748 Get_Next_Interp (I, It);
2749 end loop Interp_Loop;
2752 -- At this stage Found indicates whether or not an acceptable
2753 -- interpretation exists. If not, then we have an error, except that if
2754 -- the context is Any_Type as a result of some other error, then we
2755 -- suppress the error report.
2758 if Typ /= Any_Type then
2760 -- If type we are looking for is Void, then this is the procedure
2761 -- call case, and the error is simply that what we gave is not a
2762 -- procedure name (we think of procedure calls as expressions with
2763 -- types internally, but the user doesn't think of them this way).
2765 if Typ = Standard_Void_Type then
2767 -- Special case message if function used as a procedure
2769 if Nkind (N) = N_Procedure_Call_Statement
2770 and then Is_Entity_Name (Name (N))
2771 and then Ekind (Entity (Name (N))) = E_Function
2774 ("cannot use call to function & as a statement",
2775 Name (N), Entity (Name (N)));
2777 ("\return value of a function call cannot be ignored",
2780 -- Otherwise give general message (not clear what cases this
2781 -- covers, but no harm in providing for them).
2784 Error_Msg_N ("expect procedure name in procedure call", N);
2789 -- Otherwise we do have a subexpression with the wrong type
2791 -- Check for the case of an allocator which uses an access type
2792 -- instead of the designated type. This is a common error and we
2793 -- specialize the message, posting an error on the operand of the
2794 -- allocator, complaining that we expected the designated type of
2797 elsif Nkind (N) = N_Allocator
2798 and then Is_Access_Type (Typ)
2799 and then Is_Access_Type (Etype (N))
2800 and then Designated_Type (Etype (N)) = Typ
2802 Wrong_Type (Expression (N), Designated_Type (Typ));
2805 -- Check for view mismatch on Null in instances, for which the
2806 -- view-swapping mechanism has no identifier.
2808 elsif (In_Instance or else In_Inlined_Body)
2809 and then (Nkind (N) = N_Null)
2810 and then Is_Private_Type (Typ)
2811 and then Is_Access_Type (Full_View (Typ))
2813 Resolve (N, Full_View (Typ));
2817 -- Check for an aggregate. Sometimes we can get bogus aggregates
2818 -- from misuse of parentheses, and we are about to complain about
2819 -- the aggregate without even looking inside it.
2821 -- Instead, if we have an aggregate of type Any_Composite, then
2822 -- analyze and resolve the component fields, and then only issue
2823 -- another message if we get no errors doing this (otherwise
2824 -- assume that the errors in the aggregate caused the problem).
2826 elsif Nkind (N) = N_Aggregate
2827 and then Etype (N) = Any_Composite
2829 -- Disable expansion in any case. If there is a type mismatch
2830 -- it may be fatal to try to expand the aggregate. The flag
2831 -- would otherwise be set to false when the error is posted.
2833 Expander_Active := False;
2836 procedure Check_Aggr (Aggr : Node_Id);
2837 -- Check one aggregate, and set Found to True if we have a
2838 -- definite error in any of its elements
2840 procedure Check_Elmt (Aelmt : Node_Id);
2841 -- Check one element of aggregate and set Found to True if
2842 -- we definitely have an error in the element.
2848 procedure Check_Aggr (Aggr : Node_Id) is
2852 if Present (Expressions (Aggr)) then
2853 Elmt := First (Expressions (Aggr));
2854 while Present (Elmt) loop
2860 if Present (Component_Associations (Aggr)) then
2861 Elmt := First (Component_Associations (Aggr));
2862 while Present (Elmt) loop
2864 -- If this is a default-initialized component, then
2865 -- there is nothing to check. The box will be
2866 -- replaced by the appropriate call during late
2869 if Nkind (Elmt) /= N_Iterated_Component_Association
2870 and then not Box_Present (Elmt)
2872 Check_Elmt (Expression (Elmt));
2884 procedure Check_Elmt (Aelmt : Node_Id) is
2886 -- If we have a nested aggregate, go inside it (to
2887 -- attempt a naked analyze-resolve of the aggregate can
2888 -- cause undesirable cascaded errors). Do not resolve
2889 -- expression if it needs a type from context, as for
2890 -- integer * fixed expression.
2892 if Nkind (Aelmt) = N_Aggregate then
2898 if not Is_Overloaded (Aelmt)
2899 and then Etype (Aelmt) /= Any_Fixed
2904 if Etype (Aelmt) = Any_Type then
2915 -- Looks like we have a type error, but check for special case
2916 -- of Address wanted, integer found, with the configuration pragma
2917 -- Allow_Integer_Address active. If we have this case, introduce
2918 -- an unchecked conversion to allow the integer expression to be
2919 -- treated as an Address. The reverse case of integer wanted,
2920 -- Address found, is treated in an analogous manner.
2922 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2923 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2924 Analyze_And_Resolve (N, Typ);
2927 -- Under relaxed RM semantics silently replace occurrences of null
2928 -- by System.Address_Null.
2930 elsif Null_To_Null_Address_Convert_OK (N, Typ) then
2931 Replace_Null_By_Null_Address (N);
2932 Analyze_And_Resolve (N, Typ);
2936 -- That special Allow_Integer_Address check did not apply, so we
2937 -- have a real type error. If an error message was issued already,
2938 -- Found got reset to True, so if it's still False, issue standard
2939 -- Wrong_Type message.
2942 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2944 Subp_Name : Node_Id;
2947 if Is_Entity_Name (Name (N)) then
2948 Subp_Name := Name (N);
2950 elsif Nkind (Name (N)) = N_Selected_Component then
2952 -- Protected operation: retrieve operation name
2954 Subp_Name := Selector_Name (Name (N));
2957 raise Program_Error;
2960 Error_Msg_Node_2 := Typ;
2962 ("no visible interpretation of& matches expected type&",
2966 if All_Errors_Mode then
2968 Index : Interp_Index;
2972 Error_Msg_N ("\\possible interpretations:", N);
2974 Get_First_Interp (Name (N), Index, It);
2975 while Present (It.Nam) loop
2976 Error_Msg_Sloc := Sloc (It.Nam);
2977 Error_Msg_Node_2 := It.Nam;
2979 ("\\ type& for & declared#", N, It.Typ);
2980 Get_Next_Interp (Index, It);
2985 Error_Msg_N ("\use -gnatf for details", N);
2989 Wrong_Type (N, Typ);
2997 -- Test if we have more than one interpretation for the context
2999 elsif Ambiguous then
3003 -- Only one intepretation
3006 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
3007 -- the "+" on T is abstract, and the operands are of universal type,
3008 -- the above code will have (incorrectly) resolved the "+" to the
3009 -- universal one in Standard. Therefore check for this case and give
3010 -- an error. We can't do this earlier, because it would cause legal
3011 -- cases to get errors (when some other type has an abstract "+").
3013 if Ada_Version >= Ada_2005
3014 and then Nkind (N) in N_Op
3015 and then Is_Overloaded (N)
3016 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
3018 Get_First_Interp (N, I, It);
3019 while Present (It.Typ) loop
3020 if Present (It.Abstract_Op) and then
3021 Etype (It.Abstract_Op) = Typ
3024 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
3028 Get_Next_Interp (I, It);
3032 -- Here we have an acceptable interpretation for the context
3034 -- Propagate type information and normalize tree for various
3035 -- predefined operations. If the context only imposes a class of
3036 -- types, rather than a specific type, propagate the actual type
3039 if Typ = Any_Integer or else
3040 Typ = Any_Boolean or else
3041 Typ = Any_Modular or else
3042 Typ = Any_Real or else
3045 Ctx_Type := Expr_Type;
3047 -- Any_Fixed is legal in a real context only if a specific fixed-
3048 -- point type is imposed. If Norman Cohen can be confused by this,
3049 -- it deserves a separate message.
3052 and then Expr_Type = Any_Fixed
3054 Error_Msg_N ("illegal context for mixed mode operation", N);
3055 Set_Etype (N, Universal_Real);
3056 Ctx_Type := Universal_Real;
3060 -- A user-defined operator is transformed into a function call at
3061 -- this point, so that further processing knows that operators are
3062 -- really operators (i.e. are predefined operators). User-defined
3063 -- operators that are intrinsic are just renamings of the predefined
3064 -- ones, and need not be turned into calls either, but if they rename
3065 -- a different operator, we must transform the node accordingly.
3066 -- Instantiations of Unchecked_Conversion are intrinsic but are
3067 -- treated as functions, even if given an operator designator.
3069 if Nkind (N) in N_Op
3070 and then Present (Entity (N))
3071 and then Ekind (Entity (N)) /= E_Operator
3073 if not Is_Predefined_Op (Entity (N)) then
3074 Rewrite_Operator_As_Call (N, Entity (N));
3076 elsif Present (Alias (Entity (N)))
3078 Nkind (Parent (Parent (Entity (N)))) =
3079 N_Subprogram_Renaming_Declaration
3081 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
3083 -- If the node is rewritten, it will be fully resolved in
3084 -- Rewrite_Renamed_Operator.
3086 if Analyzed (N) then
3092 case N_Subexpr'(Nkind (N)) is
3094 Resolve_Aggregate (N, Ctx_Type);
3097 Resolve_Allocator (N, Ctx_Type);
3099 when N_Short_Circuit =>
3100 Resolve_Short_Circuit (N, Ctx_Type);
3102 when N_Attribute_Reference =>
3103 Resolve_Attribute (N, Ctx_Type);
3105 when N_Case_Expression =>
3106 Resolve_Case_Expression (N, Ctx_Type);
3108 when N_Character_Literal =>
3109 Resolve_Character_Literal (N, Ctx_Type);
3111 when N_Delta_Aggregate =>
3112 Resolve_Delta_Aggregate (N, Ctx_Type);
3114 when N_Expanded_Name =>
3115 Resolve_Entity_Name (N, Ctx_Type);
3117 when N_Explicit_Dereference =>
3118 Resolve_Explicit_Dereference (N, Ctx_Type);
3120 when N_Expression_With_Actions =>
3121 Resolve_Expression_With_Actions (N, Ctx_Type);
3123 when N_Extension_Aggregate =>
3124 Resolve_Extension_Aggregate (N, Ctx_Type);
3126 when N_Function_Call =>
3127 Resolve_Call (N, Ctx_Type);
3129 when N_Identifier =>
3130 Resolve_Entity_Name (N, Ctx_Type);
3132 when N_If_Expression =>
3133 Resolve_If_Expression (N, Ctx_Type);
3135 when N_Indexed_Component =>
3136 Resolve_Indexed_Component (N, Ctx_Type);
3138 when N_Integer_Literal =>
3139 Resolve_Integer_Literal (N, Ctx_Type);
3141 when N_Membership_Test =>
3142 Resolve_Membership_Op (N, Ctx_Type);
3145 Resolve_Null (N, Ctx_Type);
3151 Resolve_Logical_Op (N, Ctx_Type);
3156 Resolve_Equality_Op (N, Ctx_Type);
3163 Resolve_Comparison_Op (N, Ctx_Type);
3166 Resolve_Op_Not (N, Ctx_Type);
3175 Resolve_Arithmetic_Op (N, Ctx_Type);
3178 Resolve_Op_Concat (N, Ctx_Type);
3181 Resolve_Op_Expon (N, Ctx_Type);
3187 Resolve_Unary_Op (N, Ctx_Type);
3190 Resolve_Shift (N, Ctx_Type);
3192 when N_Procedure_Call_Statement =>
3193 Resolve_Call (N, Ctx_Type);
3195 when N_Operator_Symbol =>
3196 Resolve_Operator_Symbol (N, Ctx_Type);
3198 when N_Qualified_Expression =>
3199 Resolve_Qualified_Expression (N, Ctx_Type);
3201 -- Why is the following null, needs a comment ???
3203 when N_Quantified_Expression =>
3206 when N_Raise_Expression =>
3207 Resolve_Raise_Expression (N, Ctx_Type);
3209 when N_Raise_xxx_Error =>
3210 Set_Etype (N, Ctx_Type);
3213 Resolve_Range (N, Ctx_Type);
3215 when N_Real_Literal =>
3216 Resolve_Real_Literal (N, Ctx_Type);
3219 Resolve_Reference (N, Ctx_Type);
3221 when N_Selected_Component =>
3222 Resolve_Selected_Component (N, Ctx_Type);
3225 Resolve_Slice (N, Ctx_Type);
3227 when N_String_Literal =>
3228 Resolve_String_Literal (N, Ctx_Type);
3230 when N_Target_Name =>
3231 Resolve_Target_Name (N, Ctx_Type);
3233 when N_Type_Conversion =>
3234 Resolve_Type_Conversion (N, Ctx_Type);
3236 when N_Unchecked_Expression =>
3237 Resolve_Unchecked_Expression (N, Ctx_Type);
3239 when N_Unchecked_Type_Conversion =>
3240 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
3243 -- Mark relevant use-type and use-package clauses as effective using
3244 -- the original node because constant folding may have occured and
3245 -- removed references that need to be examined.
3247 if Nkind (Original_Node (N)) in N_Op then
3248 Mark_Use_Clauses (Original_Node (N));
3251 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
3252 -- expression of an anonymous access type that occurs in the context
3253 -- of a named general access type, except when the expression is that
3254 -- of a membership test. This ensures proper legality checking in
3255 -- terms of allowed conversions (expressions that would be illegal to
3256 -- convert implicitly are allowed in membership tests).
3258 if Ada_Version >= Ada_2012
3259 and then Ekind (Base_Type (Ctx_Type)) = E_General_Access_Type
3260 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3261 and then Nkind (Parent (N)) not in N_Membership_Test
3263 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3264 Analyze_And_Resolve (N, Ctx_Type);
3267 -- If the subexpression was replaced by a non-subexpression, then
3268 -- all we do is to expand it. The only legitimate case we know of
3269 -- is converting procedure call statement to entry call statements,
3270 -- but there may be others, so we are making this test general.
3272 if Nkind (N) not in N_Subexpr then
3273 Debug_A_Exit ("resolving ", N, " (done)");
3278 -- The expression is definitely NOT overloaded at this point, so
3279 -- we reset the Is_Overloaded flag to avoid any confusion when
3280 -- reanalyzing the node.
3282 Set_Is_Overloaded (N, False);
3284 -- Freeze expression type, entity if it is a name, and designated
3285 -- type if it is an allocator (RM 13.14(10,11,13)).
3287 -- Now that the resolution of the type of the node is complete, and
3288 -- we did not detect an error, we can expand this node. We skip the
3289 -- expand call if we are in a default expression, see section
3290 -- "Handling of Default Expressions" in Sem spec.
3292 Debug_A_Exit ("resolving ", N, " (done)");
3294 -- We unconditionally freeze the expression, even if we are in
3295 -- default expression mode (the Freeze_Expression routine tests this
3296 -- flag and only freezes static types if it is set).
3298 -- Ada 2012 (AI05-177): The declaration of an expression function
3299 -- does not cause freezing, but we never reach here in that case.
3300 -- Here we are resolving the corresponding expanded body, so we do
3301 -- need to perform normal freezing.
3303 -- As elsewhere we do not emit freeze node within a generic. We make
3304 -- an exception for entities that are expressions, only to detect
3305 -- misuses of deferred constants and preserve the output of various
3308 if not Inside_A_Generic or else Is_Entity_Name (N) then
3309 Freeze_Expression (N);
3312 -- Now we can do the expansion
3322 -- Version with check(s) suppressed
3324 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3326 if Suppress = All_Checks then
3328 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3330 Scope_Suppress.Suppress := (others => True);
3332 Scope_Suppress.Suppress := Sva;
3337 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3339 Scope_Suppress.Suppress (Suppress) := True;
3341 Scope_Suppress.Suppress (Suppress) := Svg;
3350 -- Version with implicit type
3352 procedure Resolve (N : Node_Id) is
3354 Resolve (N, Etype (N));
3357 ---------------------
3358 -- Resolve_Actuals --
3359 ---------------------
3361 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3362 Loc : constant Source_Ptr := Sloc (N);
3365 A_Typ : Entity_Id := Empty; -- init to avoid warning
3368 Prev : Node_Id := Empty;
3370 Real_F : Entity_Id := Empty; -- init to avoid warning
3372 Real_Subp : Entity_Id;
3373 -- If the subprogram being called is an inherited operation for
3374 -- a formal derived type in an instance, Real_Subp is the subprogram
3375 -- that will be called. It may have different formal names than the
3376 -- operation of the formal in the generic, so after actual is resolved
3377 -- the name of the actual in a named association must carry the name
3378 -- of the actual of the subprogram being called.
3380 procedure Check_Aliased_Parameter;
3381 -- Check rules on aliased parameters and related accessibility rules
3382 -- in (RM 3.10.2 (10.2-10.4)).
3384 procedure Check_Argument_Order;
3385 -- Performs a check for the case where the actuals are all simple
3386 -- identifiers that correspond to the formal names, but in the wrong
3387 -- order, which is considered suspicious and cause for a warning.
3389 procedure Check_Prefixed_Call;
3390 -- If the original node is an overloaded call in prefix notation,
3391 -- insert an 'Access or a dereference as needed over the first actual.
3392 -- Try_Object_Operation has already verified that there is a valid
3393 -- interpretation, but the form of the actual can only be determined
3394 -- once the primitive operation is identified.
3396 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id);
3397 -- Emit an error concerning the illegal usage of an effectively volatile
3398 -- object in interfering context (SPARK RM 7.13(12)).
3400 procedure Insert_Default;
3401 -- If the actual is missing in a call, insert in the actuals list
3402 -- an instance of the default expression. The insertion is always
3403 -- a named association.
3405 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3406 -- Check whether T1 and T2, or their full views, are derived from a
3407 -- common type. Used to enforce the restrictions on array conversions
3410 function Static_Concatenation (N : Node_Id) return Boolean;
3411 -- Predicate to determine whether an actual that is a concatenation
3412 -- will be evaluated statically and does not need a transient scope.
3413 -- This must be determined before the actual is resolved and expanded
3414 -- because if needed the transient scope must be introduced earlier.
3416 -----------------------------
3417 -- Check_Aliased_Parameter --
3418 -----------------------------
3420 procedure Check_Aliased_Parameter is
3421 Nominal_Subt : Entity_Id;
3424 if Is_Aliased (F) then
3425 if Is_Tagged_Type (A_Typ) then
3428 elsif Is_Aliased_View (A) then
3429 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3430 Nominal_Subt := Base_Type (A_Typ);
3432 Nominal_Subt := A_Typ;
3435 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3438 -- In a generic body assume the worst for generic formals:
3439 -- they can have a constrained partial view (AI05-041).
3441 elsif Has_Discriminants (F_Typ)
3442 and then not Is_Constrained (F_Typ)
3443 and then not Has_Constrained_Partial_View (F_Typ)
3444 and then not Is_Generic_Type (F_Typ)
3449 Error_Msg_NE ("untagged actual does not match "
3450 & "aliased formal&", A, F);
3454 Error_Msg_NE ("actual for aliased formal& must be "
3455 & "aliased object", A, F);
3458 if Ekind (Nam) = E_Procedure then
3461 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3462 if Nkind (Parent (N)) = N_Type_Conversion
3463 and then Type_Access_Level (Etype (Parent (N))) <
3464 Object_Access_Level (A)
3466 Error_Msg_N ("aliased actual has wrong accessibility", A);
3469 elsif Nkind (Parent (N)) = N_Qualified_Expression
3470 and then Nkind (Parent (Parent (N))) = N_Allocator
3471 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3472 Object_Access_Level (A)
3475 ("aliased actual in allocator has wrong accessibility", A);
3478 end Check_Aliased_Parameter;
3480 --------------------------
3481 -- Check_Argument_Order --
3482 --------------------------
3484 procedure Check_Argument_Order is
3486 -- Nothing to do if no parameters, or original node is neither a
3487 -- function call nor a procedure call statement (happens in the
3488 -- operator-transformed-to-function call case), or the call is to an
3489 -- operator symbol (which is usually in infix form), or the call does
3490 -- not come from source, or this warning is off.
3492 if not Warn_On_Parameter_Order
3493 or else No (Parameter_Associations (N))
3494 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3495 or else (Nkind (Name (N)) = N_Identifier
3496 and then Present (Entity (Name (N)))
3497 and then Nkind (Entity (Name (N))) =
3498 N_Defining_Operator_Symbol)
3499 or else not Comes_From_Source (N)
3505 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3508 -- Nothing to do if only one parameter
3514 -- Here if at least two arguments
3517 Actuals : array (1 .. Nargs) of Node_Id;
3521 Wrong_Order : Boolean := False;
3522 -- Set True if an out of order case is found
3525 -- Collect identifier names of actuals, fail if any actual is
3526 -- not a simple identifier, and record max length of name.
3528 Actual := First (Parameter_Associations (N));
3529 for J in Actuals'Range loop
3530 if Nkind (Actual) /= N_Identifier then
3533 Actuals (J) := Actual;
3538 -- If we got this far, all actuals are identifiers and the list
3539 -- of their names is stored in the Actuals array.
3541 Formal := First_Formal (Nam);
3542 for J in Actuals'Range loop
3544 -- If we ran out of formals, that's odd, probably an error
3545 -- which will be detected elsewhere, but abandon the search.
3551 -- If name matches and is in order OK
3553 if Chars (Formal) = Chars (Actuals (J)) then
3557 -- If no match, see if it is elsewhere in list and if so
3558 -- flag potential wrong order if type is compatible.
3560 for K in Actuals'Range loop
3561 if Chars (Formal) = Chars (Actuals (K))
3563 Has_Compatible_Type (Actuals (K), Etype (Formal))
3565 Wrong_Order := True;
3575 <<Continue>> Next_Formal (Formal);
3578 -- If Formals left over, also probably an error, skip warning
3580 if Present (Formal) then
3584 -- Here we give the warning if something was out of order
3588 ("?P?actuals for this call may be in wrong order", N);
3592 end Check_Argument_Order;
3594 -------------------------
3595 -- Check_Prefixed_Call --
3596 -------------------------
3598 procedure Check_Prefixed_Call is
3599 Act : constant Node_Id := First_Actual (N);
3600 A_Type : constant Entity_Id := Etype (Act);
3601 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3602 Orig : constant Node_Id := Original_Node (N);
3606 -- Check whether the call is a prefixed call, with or without
3607 -- additional actuals.
3609 if Nkind (Orig) = N_Selected_Component
3611 (Nkind (Orig) = N_Indexed_Component
3612 and then Nkind (Prefix (Orig)) = N_Selected_Component
3613 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3614 and then Is_Entity_Name (Act)
3615 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3617 if Is_Access_Type (A_Type)
3618 and then not Is_Access_Type (F_Type)
3620 -- Introduce dereference on object in prefix
3623 Make_Explicit_Dereference (Sloc (Act),
3624 Prefix => Relocate_Node (Act));
3625 Rewrite (Act, New_A);
3628 elsif Is_Access_Type (F_Type)
3629 and then not Is_Access_Type (A_Type)
3631 -- Introduce an implicit 'Access in prefix
3633 if not Is_Aliased_View (Act) then
3635 ("object in prefixed call to& must be aliased "
3636 & "(RM 4.1.3 (13 1/2))",
3641 Make_Attribute_Reference (Loc,
3642 Attribute_Name => Name_Access,
3643 Prefix => Relocate_Node (Act)));
3648 end Check_Prefixed_Call;
3650 ---------------------------------------
3651 -- Flag_Effectively_Volatile_Objects --
3652 ---------------------------------------
3654 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id) is
3655 function Flag_Object (N : Node_Id) return Traverse_Result;
3656 -- Determine whether arbitrary node N denotes an effectively volatile
3657 -- object and if it does, emit an error.
3663 function Flag_Object (N : Node_Id) return Traverse_Result is
3667 -- Do not consider nested function calls because they have already
3668 -- been processed during their own resolution.
3670 if Nkind (N) = N_Function_Call then
3673 elsif Is_Entity_Name (N) and then Present (Entity (N)) then
3677 and then Is_Effectively_Volatile (Id)
3678 and then (Async_Writers_Enabled (Id)
3679 or else Effective_Reads_Enabled (Id))
3682 ("volatile object cannot appear in this context (SPARK "
3683 & "RM 7.1.3(11))", N);
3691 procedure Flag_Objects is new Traverse_Proc (Flag_Object);
3693 -- Start of processing for Flag_Effectively_Volatile_Objects
3696 Flag_Objects (Expr);
3697 end Flag_Effectively_Volatile_Objects;
3699 --------------------
3700 -- Insert_Default --
3701 --------------------
3703 procedure Insert_Default is
3708 -- Missing argument in call, nothing to insert
3710 if No (Default_Value (F)) then
3714 -- Note that we do a full New_Copy_Tree, so that any associated
3715 -- Itypes are properly copied. This may not be needed any more,
3716 -- but it does no harm as a safety measure. Defaults of a generic
3717 -- formal may be out of bounds of the corresponding actual (see
3718 -- cc1311b) and an additional check may be required.
3723 New_Scope => Current_Scope,
3726 -- Propagate dimension information, if any.
3728 Copy_Dimensions (Default_Value (F), Actval);
3730 if Is_Concurrent_Type (Scope (Nam))
3731 and then Has_Discriminants (Scope (Nam))
3733 Replace_Actual_Discriminants (N, Actval);
3736 if Is_Overloadable (Nam)
3737 and then Present (Alias (Nam))
3739 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3740 and then not Is_Tagged_Type (Etype (F))
3742 -- If default is a real literal, do not introduce a
3743 -- conversion whose effect may depend on the run-time
3744 -- size of universal real.
3746 if Nkind (Actval) = N_Real_Literal then
3747 Set_Etype (Actval, Base_Type (Etype (F)));
3749 Actval := Unchecked_Convert_To (Etype (F), Actval);
3753 if Is_Scalar_Type (Etype (F)) then
3754 Enable_Range_Check (Actval);
3757 Set_Parent (Actval, N);
3759 -- Resolve aggregates with their base type, to avoid scope
3760 -- anomalies: the subtype was first built in the subprogram
3761 -- declaration, and the current call may be nested.
3763 if Nkind (Actval) = N_Aggregate then
3764 Analyze_And_Resolve (Actval, Etype (F));
3766 Analyze_And_Resolve (Actval, Etype (Actval));
3770 Set_Parent (Actval, N);
3772 -- See note above concerning aggregates
3774 if Nkind (Actval) = N_Aggregate
3775 and then Has_Discriminants (Etype (Actval))
3777 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3779 -- Resolve entities with their own type, which may differ from
3780 -- the type of a reference in a generic context (the view
3781 -- swapping mechanism did not anticipate the re-analysis of
3782 -- default values in calls).
3784 elsif Is_Entity_Name (Actval) then
3785 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3788 Analyze_And_Resolve (Actval, Etype (Actval));
3792 -- If default is a tag indeterminate function call, propagate tag
3793 -- to obtain proper dispatching.
3795 if Is_Controlling_Formal (F)
3796 and then Nkind (Default_Value (F)) = N_Function_Call
3798 Set_Is_Controlling_Actual (Actval);
3802 -- If the default expression raises constraint error, then just
3803 -- silently replace it with an N_Raise_Constraint_Error node, since
3804 -- we already gave the warning on the subprogram spec. If node is
3805 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3806 -- the warnings removal machinery.
3808 if Raises_Constraint_Error (Actval)
3809 and then Nkind (Actval) /= N_Raise_Constraint_Error
3812 Make_Raise_Constraint_Error (Loc,
3813 Reason => CE_Range_Check_Failed));
3815 Set_Raises_Constraint_Error (Actval);
3816 Set_Etype (Actval, Etype (F));
3820 Make_Parameter_Association (Loc,
3821 Explicit_Actual_Parameter => Actval,
3822 Selector_Name => Make_Identifier (Loc, Chars (F)));
3824 -- Case of insertion is first named actual
3827 or else Nkind (Parent (Prev)) /= N_Parameter_Association
3829 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3830 Set_First_Named_Actual (N, Actval);
3833 if No (Parameter_Associations (N)) then
3834 Set_Parameter_Associations (N, New_List (Assoc));
3836 Append (Assoc, Parameter_Associations (N));
3840 Insert_After (Prev, Assoc);
3843 -- Case of insertion is not first named actual
3846 Set_Next_Named_Actual
3847 (Assoc, Next_Named_Actual (Parent (Prev)));
3848 Set_Next_Named_Actual (Parent (Prev), Actval);
3849 Append (Assoc, Parameter_Associations (N));
3852 Mark_Rewrite_Insertion (Assoc);
3853 Mark_Rewrite_Insertion (Actval);
3862 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3863 FT1 : Entity_Id := T1;
3864 FT2 : Entity_Id := T2;
3867 if Is_Private_Type (T1)
3868 and then Present (Full_View (T1))
3870 FT1 := Full_View (T1);
3873 if Is_Private_Type (T2)
3874 and then Present (Full_View (T2))
3876 FT2 := Full_View (T2);
3879 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3882 --------------------------
3883 -- Static_Concatenation --
3884 --------------------------
3886 function Static_Concatenation (N : Node_Id) return Boolean is
3889 when N_String_Literal =>
3894 -- Concatenation is static when both operands are static and
3895 -- the concatenation operator is a predefined one.
3897 return Scope (Entity (N)) = Standard_Standard
3899 Static_Concatenation (Left_Opnd (N))
3901 Static_Concatenation (Right_Opnd (N));
3904 if Is_Entity_Name (N) then
3906 Ent : constant Entity_Id := Entity (N);
3908 return Ekind (Ent) = E_Constant
3909 and then Present (Constant_Value (Ent))
3911 Is_OK_Static_Expression (Constant_Value (Ent));
3918 end Static_Concatenation;
3920 -- Start of processing for Resolve_Actuals
3923 Check_Argument_Order;
3925 if Is_Overloadable (Nam)
3926 and then Is_Inherited_Operation (Nam)
3927 and then In_Instance
3928 and then Present (Alias (Nam))
3929 and then Present (Overridden_Operation (Alias (Nam)))
3931 Real_Subp := Alias (Nam);
3936 if Present (First_Actual (N)) then
3937 Check_Prefixed_Call;
3940 A := First_Actual (N);
3941 F := First_Formal (Nam);
3943 if Present (Real_Subp) then
3944 Real_F := First_Formal (Real_Subp);
3947 while Present (F) loop
3948 if No (A) and then Needs_No_Actuals (Nam) then
3951 -- If we have an error in any actual or formal, indicated by a type
3952 -- of Any_Type, then abandon resolution attempt, and set result type
3953 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3954 -- type is imposed from context.
3956 elsif (Present (A) and then Etype (A) = Any_Type)
3957 or else Etype (F) = Any_Type
3959 if Nkind (A) /= N_Raise_Expression then
3960 Set_Etype (N, Any_Type);
3965 -- Case where actual is present
3967 -- If the actual is an entity, generate a reference to it now. We
3968 -- do this before the actual is resolved, because a formal of some
3969 -- protected subprogram, or a task discriminant, will be rewritten
3970 -- during expansion, and the source entity reference may be lost.
3973 and then Is_Entity_Name (A)
3974 and then Comes_From_Source (A)
3976 -- Annotate the tree by creating a variable reference marker when
3977 -- the actual denotes a variable reference, in case the reference
3978 -- is folded or optimized away. The variable reference marker is
3979 -- automatically saved for later examination by the ABE Processing
3980 -- phase. The status of the reference is set as follows:
3984 -- write IN OUT, OUT
3986 if Needs_Variable_Reference_Marker
3990 Build_Variable_Reference_Marker
3992 Read => Ekind (F) /= E_Out_Parameter,
3993 Write => Ekind (F) /= E_In_Parameter);
3996 Orig_A := Entity (A);
3998 if Present (Orig_A) then
3999 if Is_Formal (Orig_A)
4000 and then Ekind (F) /= E_In_Parameter
4002 Generate_Reference (Orig_A, A, 'm');
4004 elsif not Is_Overloaded (A) then
4005 if Ekind (F) /= E_Out_Parameter then
4006 Generate_Reference (Orig_A, A);
4008 -- RM 6.4.1(12): For an out parameter that is passed by
4009 -- copy, the formal parameter object is created, and:
4011 -- * For an access type, the formal parameter is initialized
4012 -- from the value of the actual, without checking that the
4013 -- value satisfies any constraint, any predicate, or any
4014 -- exclusion of the null value.
4016 -- * For a scalar type that has the Default_Value aspect
4017 -- specified, the formal parameter is initialized from the
4018 -- value of the actual, without checking that the value
4019 -- satisfies any constraint or any predicate.
4020 -- I do not understand why this case is included??? this is
4021 -- not a case where an OUT parameter is treated as IN OUT.
4023 -- * For a composite type with discriminants or that has
4024 -- implicit initial values for any subcomponents, the
4025 -- behavior is as for an in out parameter passed by copy.
4027 -- Hence for these cases we generate the read reference now
4028 -- (the write reference will be generated later by
4029 -- Note_Possible_Modification).
4031 elsif Is_By_Copy_Type (Etype (F))
4033 (Is_Access_Type (Etype (F))
4035 (Is_Scalar_Type (Etype (F))
4037 Present (Default_Aspect_Value (Etype (F))))
4039 (Is_Composite_Type (Etype (F))
4040 and then (Has_Discriminants (Etype (F))
4041 or else Is_Partially_Initialized_Type
4044 Generate_Reference (Orig_A, A);
4051 and then (Nkind (Parent (A)) /= N_Parameter_Association
4052 or else Chars (Selector_Name (Parent (A))) = Chars (F))
4054 -- If style checking mode on, check match of formal name
4057 if Nkind (Parent (A)) = N_Parameter_Association then
4058 Check_Identifier (Selector_Name (Parent (A)), F);
4062 -- If the formal is Out or In_Out, do not resolve and expand the
4063 -- conversion, because it is subsequently expanded into explicit
4064 -- temporaries and assignments. However, the object of the
4065 -- conversion can be resolved. An exception is the case of tagged
4066 -- type conversion with a class-wide actual. In that case we want
4067 -- the tag check to occur and no temporary will be needed (no
4068 -- representation change can occur) and the parameter is passed by
4069 -- reference, so we go ahead and resolve the type conversion.
4070 -- Another exception is the case of reference to component or
4071 -- subcomponent of a bit-packed array, in which case we want to
4072 -- defer expansion to the point the in and out assignments are
4075 if Ekind (F) /= E_In_Parameter
4076 and then Nkind (A) = N_Type_Conversion
4077 and then not Is_Class_Wide_Type (Etype (Expression (A)))
4078 and then not Is_Interface (Etype (A))
4080 if Ekind (F) = E_In_Out_Parameter
4081 and then Is_Array_Type (Etype (F))
4083 -- In a view conversion, the conversion must be legal in
4084 -- both directions, and thus both component types must be
4085 -- aliased, or neither (4.6 (8)).
4087 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
4088 -- the privacy requirement should not apply to generic
4089 -- types, and should be checked in an instance. ARG query
4092 if Has_Aliased_Components (Etype (Expression (A))) /=
4093 Has_Aliased_Components (Etype (F))
4096 ("both component types in a view conversion must be"
4097 & " aliased, or neither", A);
4099 -- Comment here??? what set of cases???
4102 not Same_Ancestor (Etype (F), Etype (Expression (A)))
4104 -- Check view conv between unrelated by ref array types
4106 if Is_By_Reference_Type (Etype (F))
4107 or else Is_By_Reference_Type (Etype (Expression (A)))
4110 ("view conversion between unrelated by reference "
4111 & "array types not allowed (\'A'I-00246)", A);
4113 -- In Ada 2005 mode, check view conversion component
4114 -- type cannot be private, tagged, or volatile. Note
4115 -- that we only apply this to source conversions. The
4116 -- generated code can contain conversions which are
4117 -- not subject to this test, and we cannot extract the
4118 -- component type in such cases since it is not present.
4120 elsif Comes_From_Source (A)
4121 and then Ada_Version >= Ada_2005
4124 Comp_Type : constant Entity_Id :=
4126 (Etype (Expression (A)));
4128 if (Is_Private_Type (Comp_Type)
4129 and then not Is_Generic_Type (Comp_Type))
4130 or else Is_Tagged_Type (Comp_Type)
4131 or else Is_Volatile (Comp_Type)
4134 ("component type of a view conversion cannot"
4135 & " be private, tagged, or volatile"
4144 -- Resolve expression if conversion is all OK
4146 if (Conversion_OK (A)
4147 or else Valid_Conversion (A, Etype (A), Expression (A)))
4148 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
4150 Resolve (Expression (A));
4153 -- If the actual is a function call that returns a limited
4154 -- unconstrained object that needs finalization, create a
4155 -- transient scope for it, so that it can receive the proper
4156 -- finalization list.
4158 elsif Expander_Active
4159 and then Nkind (A) = N_Function_Call
4160 and then Is_Limited_Record (Etype (F))
4161 and then not Is_Constrained (Etype (F))
4162 and then (Needs_Finalization (Etype (F))
4163 or else Has_Task (Etype (F)))
4165 Establish_Transient_Scope (A, Manage_Sec_Stack => False);
4166 Resolve (A, Etype (F));
4168 -- A small optimization: if one of the actuals is a concatenation
4169 -- create a block around a procedure call to recover stack space.
4170 -- This alleviates stack usage when several procedure calls in
4171 -- the same statement list use concatenation. We do not perform
4172 -- this wrapping for code statements, where the argument is a
4173 -- static string, and we want to preserve warnings involving
4174 -- sequences of such statements.
4176 elsif Expander_Active
4177 and then Nkind (A) = N_Op_Concat
4178 and then Nkind (N) = N_Procedure_Call_Statement
4179 and then not (Is_Intrinsic_Subprogram (Nam)
4180 and then Chars (Nam) = Name_Asm)
4181 and then not Static_Concatenation (A)
4183 Establish_Transient_Scope (A, Manage_Sec_Stack => False);
4184 Resolve (A, Etype (F));
4187 if Nkind (A) = N_Type_Conversion
4188 and then Is_Array_Type (Etype (F))
4189 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
4191 (Is_Limited_Type (Etype (F))
4192 or else Is_Limited_Type (Etype (Expression (A))))
4195 ("conversion between unrelated limited array types not "
4196 & "allowed ('A'I-00246)", A);
4198 if Is_Limited_Type (Etype (F)) then
4199 Explain_Limited_Type (Etype (F), A);
4202 if Is_Limited_Type (Etype (Expression (A))) then
4203 Explain_Limited_Type (Etype (Expression (A)), A);
4207 -- (Ada 2005: AI-251): If the actual is an allocator whose
4208 -- directly designated type is a class-wide interface, we build
4209 -- an anonymous access type to use it as the type of the
4210 -- allocator. Later, when the subprogram call is expanded, if
4211 -- the interface has a secondary dispatch table the expander
4212 -- will add a type conversion to force the correct displacement
4215 if Nkind (A) = N_Allocator then
4217 DDT : constant Entity_Id :=
4218 Directly_Designated_Type (Base_Type (Etype (F)));
4221 -- Displace the pointer to the object to reference its
4222 -- secondary dispatch table.
4224 if Is_Class_Wide_Type (DDT)
4225 and then Is_Interface (DDT)
4227 Rewrite (A, Convert_To (Etype (F), Relocate_Node (A)));
4228 Analyze_And_Resolve (A, Etype (F),
4229 Suppress => Access_Check);
4232 -- Ada 2005, AI-162:If the actual is an allocator, the
4233 -- innermost enclosing statement is the master of the
4234 -- created object. This needs to be done with expansion
4235 -- enabled only, otherwise the transient scope will not
4236 -- be removed in the expansion of the wrapped construct.
4239 and then (Needs_Finalization (DDT)
4240 or else Has_Task (DDT))
4242 Establish_Transient_Scope
4243 (A, Manage_Sec_Stack => False);
4247 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4248 Check_Restriction (No_Access_Parameter_Allocators, A);
4252 -- (Ada 2005): The call may be to a primitive operation of a
4253 -- tagged synchronized type, declared outside of the type. In
4254 -- this case the controlling actual must be converted to its
4255 -- corresponding record type, which is the formal type. The
4256 -- actual may be a subtype, either because of a constraint or
4257 -- because it is a generic actual, so use base type to locate
4260 F_Typ := Base_Type (Etype (F));
4262 if Is_Tagged_Type (F_Typ)
4263 and then (Is_Concurrent_Type (F_Typ)
4264 or else Is_Concurrent_Record_Type (F_Typ))
4266 -- If the actual is overloaded, look for an interpretation
4267 -- that has a synchronized type.
4269 if not Is_Overloaded (A) then
4270 A_Typ := Base_Type (Etype (A));
4274 Index : Interp_Index;
4278 Get_First_Interp (A, Index, It);
4279 while Present (It.Typ) loop
4280 if Is_Concurrent_Type (It.Typ)
4281 or else Is_Concurrent_Record_Type (It.Typ)
4283 A_Typ := Base_Type (It.Typ);
4287 Get_Next_Interp (Index, It);
4293 Full_A_Typ : Entity_Id;
4296 if Present (Full_View (A_Typ)) then
4297 Full_A_Typ := Base_Type (Full_View (A_Typ));
4299 Full_A_Typ := A_Typ;
4302 -- Tagged synchronized type (case 1): the actual is a
4305 if Is_Concurrent_Type (A_Typ)
4306 and then Corresponding_Record_Type (A_Typ) = F_Typ
4309 Unchecked_Convert_To
4310 (Corresponding_Record_Type (A_Typ), A));
4311 Resolve (A, Etype (F));
4313 -- Tagged synchronized type (case 2): the formal is a
4316 elsif Ekind (Full_A_Typ) = E_Record_Type
4318 (Corresponding_Concurrent_Type (Full_A_Typ))
4319 and then Is_Concurrent_Type (F_Typ)
4320 and then Present (Corresponding_Record_Type (F_Typ))
4321 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4323 Resolve (A, Corresponding_Record_Type (F_Typ));
4328 Resolve (A, Etype (F));
4332 -- Not a synchronized operation
4335 Resolve (A, Etype (F));
4342 -- An actual cannot be an untagged formal incomplete type
4344 if Ekind (A_Typ) = E_Incomplete_Type
4345 and then not Is_Tagged_Type (A_Typ)
4346 and then Is_Generic_Type (A_Typ)
4349 ("invalid use of untagged formal incomplete type", A);
4352 if Comes_From_Source (Original_Node (N))
4353 and then Nkind_In (Original_Node (N), N_Function_Call,
4354 N_Procedure_Call_Statement)
4356 -- In formal mode, check that actual parameters matching
4357 -- formals of tagged types are objects (or ancestor type
4358 -- conversions of objects), not general expressions.
4360 if Is_Actual_Tagged_Parameter (A) then
4361 if Is_SPARK_05_Object_Reference (A) then
4364 elsif Nkind (A) = N_Type_Conversion then
4366 Operand : constant Node_Id := Expression (A);
4367 Operand_Typ : constant Entity_Id := Etype (Operand);
4368 Target_Typ : constant Entity_Id := A_Typ;
4371 if not Is_SPARK_05_Object_Reference (Operand) then
4372 Check_SPARK_05_Restriction
4373 ("object required", Operand);
4375 -- In formal mode, the only view conversions are those
4376 -- involving ancestor conversion of an extended type.
4379 (Is_Tagged_Type (Target_Typ)
4380 and then not Is_Class_Wide_Type (Target_Typ)
4381 and then Is_Tagged_Type (Operand_Typ)
4382 and then not Is_Class_Wide_Type (Operand_Typ)
4383 and then Is_Ancestor (Target_Typ, Operand_Typ))
4386 (F, E_Out_Parameter, E_In_Out_Parameter)
4388 Check_SPARK_05_Restriction
4389 ("ancestor conversion is the only permitted "
4390 & "view conversion", A);
4392 Check_SPARK_05_Restriction
4393 ("ancestor conversion required", A);
4402 Check_SPARK_05_Restriction ("object required", A);
4405 -- In formal mode, the only view conversions are those
4406 -- involving ancestor conversion of an extended type.
4408 elsif Nkind (A) = N_Type_Conversion
4409 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4411 Check_SPARK_05_Restriction
4412 ("ancestor conversion is the only permitted view "
4417 -- has warnings suppressed, then we reset Never_Set_In_Source for
4418 -- the calling entity. The reason for this is to catch cases like
4419 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4420 -- uses trickery to modify an IN parameter.
4422 if Ekind (F) = E_In_Parameter
4423 and then Is_Entity_Name (A)
4424 and then Present (Entity (A))
4425 and then Ekind (Entity (A)) = E_Variable
4426 and then Has_Warnings_Off (F_Typ)
4428 Set_Never_Set_In_Source (Entity (A), False);
4431 -- Perform error checks for IN and IN OUT parameters
4433 if Ekind (F) /= E_Out_Parameter then
4435 -- Check unset reference. For scalar parameters, it is clearly
4436 -- wrong to pass an uninitialized value as either an IN or
4437 -- IN-OUT parameter. For composites, it is also clearly an
4438 -- error to pass a completely uninitialized value as an IN
4439 -- parameter, but the case of IN OUT is trickier. We prefer
4440 -- not to give a warning here. For example, suppose there is
4441 -- a routine that sets some component of a record to False.
4442 -- It is perfectly reasonable to make this IN-OUT and allow
4443 -- either initialized or uninitialized records to be passed
4446 -- For partially initialized composite values, we also avoid
4447 -- warnings, since it is quite likely that we are passing a
4448 -- partially initialized value and only the initialized fields
4449 -- will in fact be read in the subprogram.
4451 if Is_Scalar_Type (A_Typ)
4452 or else (Ekind (F) = E_In_Parameter
4453 and then not Is_Partially_Initialized_Type (A_Typ))
4455 Check_Unset_Reference (A);
4458 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4459 -- actual to a nested call, since this constitutes a reading of
4460 -- the parameter, which is not allowed.
4462 if Ada_Version = Ada_83
4463 and then Is_Entity_Name (A)
4464 and then Ekind (Entity (A)) = E_Out_Parameter
4466 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4470 -- In -gnatd.q mode, forget that a given array is constant when
4471 -- it is passed as an IN parameter to a foreign-convention
4472 -- subprogram. This is in case the subprogram evilly modifies the
4473 -- object. Of course, correct code would use IN OUT.
4476 and then Ekind (F) = E_In_Parameter
4477 and then Has_Foreign_Convention (Nam)
4478 and then Is_Array_Type (F_Typ)
4479 and then Nkind (A) in N_Has_Entity
4480 and then Present (Entity (A))
4482 Set_Is_True_Constant (Entity (A), False);
4485 -- Case of OUT or IN OUT parameter
4487 if Ekind (F) /= E_In_Parameter then
4489 -- For an Out parameter, check for useless assignment. Note
4490 -- that we can't set Last_Assignment this early, because we may
4491 -- kill current values in Resolve_Call, and that call would
4492 -- clobber the Last_Assignment field.
4494 -- Note: call Warn_On_Useless_Assignment before doing the check
4495 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4496 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4497 -- reflects the last assignment, not this one.
4499 if Ekind (F) = E_Out_Parameter then
4500 if Warn_On_Modified_As_Out_Parameter (F)
4501 and then Is_Entity_Name (A)
4502 and then Present (Entity (A))
4503 and then Comes_From_Source (N)
4505 Warn_On_Useless_Assignment (Entity (A), A);
4509 -- Validate the form of the actual. Note that the call to
4510 -- Is_OK_Variable_For_Out_Formal generates the required
4511 -- reference in this case.
4513 -- A call to an initialization procedure for an aggregate
4514 -- component may initialize a nested component of a constant
4515 -- designated object. In this context the object is variable.
4517 if not Is_OK_Variable_For_Out_Formal (A)
4518 and then not Is_Init_Proc (Nam)
4520 Error_Msg_NE ("actual for& must be a variable", A, F);
4522 if Is_Subprogram (Current_Scope) then
4523 if Is_Invariant_Procedure (Current_Scope)
4524 or else Is_Partial_Invariant_Procedure (Current_Scope)
4527 ("function used in invariant cannot modify its "
4530 elsif Is_Predicate_Function (Current_Scope) then
4532 ("function used in predicate cannot modify its "
4538 -- What's the following about???
4540 if Is_Entity_Name (A) then
4541 Kill_Checks (Entity (A));
4547 if A_Typ = Any_Type then
4548 Set_Etype (N, Any_Type);
4552 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4554 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4556 -- Apply predicate tests except in certain special cases. Note
4557 -- that it might be more consistent to apply these only when
4558 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4559 -- for the outbound predicate tests ??? In any case indicate
4560 -- the function being called, for better warnings if the call
4561 -- leads to an infinite recursion.
4563 if Predicate_Tests_On_Arguments (Nam) then
4564 Apply_Predicate_Check (A, F_Typ, Nam);
4567 -- Apply required constraint checks
4569 if Is_Scalar_Type (A_Typ) then
4570 Apply_Scalar_Range_Check (A, F_Typ);
4572 elsif Is_Array_Type (A_Typ) then
4573 Apply_Length_Check (A, F_Typ);
4575 elsif Is_Record_Type (F_Typ)
4576 and then Has_Discriminants (F_Typ)
4577 and then Is_Constrained (F_Typ)
4578 and then (not Is_Derived_Type (F_Typ)
4579 or else Comes_From_Source (Nam))
4581 Apply_Discriminant_Check (A, F_Typ);
4583 -- For view conversions of a discriminated object, apply
4584 -- check to object itself, the conversion alreay has the
4587 if Nkind (A) = N_Type_Conversion
4588 and then Is_Constrained (Etype (Expression (A)))
4590 Apply_Discriminant_Check (Expression (A), F_Typ);
4593 elsif Is_Access_Type (F_Typ)
4594 and then Is_Array_Type (Designated_Type (F_Typ))
4595 and then Is_Constrained (Designated_Type (F_Typ))
4597 Apply_Length_Check (A, F_Typ);
4599 elsif Is_Access_Type (F_Typ)
4600 and then Has_Discriminants (Designated_Type (F_Typ))
4601 and then Is_Constrained (Designated_Type (F_Typ))
4603 Apply_Discriminant_Check (A, F_Typ);
4606 Apply_Range_Check (A, F_Typ);
4609 -- Ada 2005 (AI-231): Note that the controlling parameter case
4610 -- already existed in Ada 95, which is partially checked
4611 -- elsewhere (see Checks), and we don't want the warning
4612 -- message to differ.
4614 if Is_Access_Type (F_Typ)
4615 and then Can_Never_Be_Null (F_Typ)
4616 and then Known_Null (A)
4618 if Is_Controlling_Formal (F) then
4619 Apply_Compile_Time_Constraint_Error
4621 Msg => "null value not allowed here??",
4622 Reason => CE_Access_Check_Failed);
4624 elsif Ada_Version >= Ada_2005 then
4625 Apply_Compile_Time_Constraint_Error
4627 Msg => "(Ada 2005) null not allowed in "
4628 & "null-excluding formal??",
4629 Reason => CE_Null_Not_Allowed);
4634 -- Checks for OUT parameters and IN OUT parameters
4636 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4638 -- If there is a type conversion, make sure the return value
4639 -- meets the constraints of the variable before the conversion.
4641 if Nkind (A) = N_Type_Conversion then
4642 if Is_Scalar_Type (A_Typ) then
4644 -- Special case here tailored to Exp_Ch6.Is_Legal_Copy,
4645 -- which would prevent the check from being generated.
4646 -- This is for Starlet only though, so long obsolete.
4648 if Mechanism (F) = By_Reference
4649 and then Is_Valued_Procedure (Nam)
4653 Apply_Scalar_Range_Check
4654 (Expression (A), Etype (Expression (A)), A_Typ);
4657 -- In addition the return value must meet the constraints
4658 -- of the object type (see the comment below).
4660 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4664 (Expression (A), Etype (Expression (A)), A_Typ);
4667 -- If no conversion, apply scalar range checks and length check
4668 -- based on the subtype of the actual (NOT that of the formal).
4669 -- This indicates that the check takes place on return from the
4670 -- call. During expansion the required constraint checks are
4671 -- inserted. In GNATprove mode, in the absence of expansion,
4672 -- the flag indicates that the returned value is valid.
4675 if Is_Scalar_Type (F_Typ) then
4676 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4678 elsif Is_Array_Type (F_Typ)
4679 and then Ekind (F) = E_Out_Parameter
4681 Apply_Length_Check (A, F_Typ);
4684 Apply_Range_Check (A, A_Typ, F_Typ);
4688 -- Note: we do not apply the predicate checks for the case of
4689 -- OUT and IN OUT parameters. They are instead applied in the
4690 -- Expand_Actuals routine in Exp_Ch6.
4693 -- An actual associated with an access parameter is implicitly
4694 -- converted to the anonymous access type of the formal and must
4695 -- satisfy the legality checks for access conversions.
4697 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4698 if not Valid_Conversion (A, F_Typ, A) then
4700 ("invalid implicit conversion for access parameter", A);
4703 -- If the actual is an access selected component of a variable,
4704 -- the call may modify its designated object. It is reasonable
4705 -- to treat this as a potential modification of the enclosing
4706 -- record, to prevent spurious warnings that it should be
4707 -- declared as a constant, because intuitively programmers
4708 -- regard the designated subcomponent as part of the record.
4710 if Nkind (A) = N_Selected_Component
4711 and then Is_Entity_Name (Prefix (A))
4712 and then not Is_Constant_Object (Entity (Prefix (A)))
4714 Note_Possible_Modification (A, Sure => False);
4718 -- Check illegal cases of atomic/volatile actual (RM C.6(12,13))
4720 if (Is_By_Reference_Type (Etype (F)) or else Is_Aliased (F))
4721 and then Comes_From_Source (N)
4723 if Is_Atomic_Object (A)
4724 and then not Is_Atomic (Etype (F))
4727 ("cannot pass atomic object to nonatomic formal&",
4730 ("\which is passed by reference (RM C.6(12))", A);
4732 elsif Is_Volatile_Object (A)
4733 and then not Is_Volatile (Etype (F))
4736 ("cannot pass volatile object to nonvolatile formal&",
4739 ("\which is passed by reference (RM C.6(12))", A);
4742 if Ada_Version >= Ada_2020
4743 and then Is_Subcomponent_Of_Atomic_Object (A)
4744 and then not Is_Atomic_Object (A)
4747 ("cannot pass nonatomic subcomponent of atomic object",
4750 ("\to formal & which is passed by reference (RM C.6(13))",
4755 -- Check that subprograms don't have improper controlling
4756 -- arguments (RM 3.9.2 (9)).
4758 -- A primitive operation may have an access parameter of an
4759 -- incomplete tagged type, but a dispatching call is illegal
4760 -- if the type is still incomplete.
4762 if Is_Controlling_Formal (F) then
4763 Set_Is_Controlling_Actual (A);
4765 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4767 Desig : constant Entity_Id := Designated_Type (Etype (F));
4769 if Ekind (Desig) = E_Incomplete_Type
4770 and then No (Full_View (Desig))
4771 and then No (Non_Limited_View (Desig))
4774 ("premature use of incomplete type& "
4775 & "in dispatching call", A, Desig);
4780 elsif Nkind (A) = N_Explicit_Dereference then
4781 Validate_Remote_Access_To_Class_Wide_Type (A);
4784 -- Apply legality rule 3.9.2 (9/1)
4786 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4787 and then not Is_Class_Wide_Type (F_Typ)
4788 and then not Is_Controlling_Formal (F)
4789 and then not In_Instance
4791 Error_Msg_N ("class-wide argument not allowed here!", A);
4793 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4794 Error_Msg_Node_2 := F_Typ;
4796 ("& is not a dispatching operation of &!", A, Nam);
4799 -- Apply the checks described in 3.10.2(27): if the context is a
4800 -- specific access-to-object, the actual cannot be class-wide.
4801 -- Use base type to exclude access_to_subprogram cases.
4803 elsif Is_Access_Type (A_Typ)
4804 and then Is_Access_Type (F_Typ)
4805 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4806 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4807 or else (Nkind (A) = N_Attribute_Reference
4809 Is_Class_Wide_Type (Etype (Prefix (A)))))
4810 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4811 and then not Is_Controlling_Formal (F)
4813 -- Disable these checks for call to imported C++ subprograms
4816 (Is_Entity_Name (Name (N))
4817 and then Is_Imported (Entity (Name (N)))
4818 and then Convention (Entity (Name (N))) = Convention_CPP)
4821 ("access to class-wide argument not allowed here!", A);
4823 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4824 Error_Msg_Node_2 := Designated_Type (F_Typ);
4826 ("& is not a dispatching operation of &!", A, Nam);
4830 Check_Aliased_Parameter;
4834 -- If it is a named association, treat the selector_name as a
4835 -- proper identifier, and mark the corresponding entity.
4837 if Nkind (Parent (A)) = N_Parameter_Association
4839 -- Ignore reference in SPARK mode, as it refers to an entity not
4840 -- in scope at the point of reference, so the reference should
4841 -- be ignored for computing effects of subprograms.
4843 and then not GNATprove_Mode
4845 -- If subprogram is overridden, use name of formal that
4848 if Present (Real_Subp) then
4849 Set_Entity (Selector_Name (Parent (A)), Real_F);
4850 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4853 Set_Entity (Selector_Name (Parent (A)), F);
4854 Generate_Reference (F, Selector_Name (Parent (A)));
4855 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4856 Generate_Reference (F_Typ, N, ' ');
4862 if Ekind (F) /= E_Out_Parameter then
4863 Check_Unset_Reference (A);
4866 -- The following checks are only relevant when SPARK_Mode is on as
4867 -- they are not standard Ada legality rule. Internally generated
4868 -- temporaries are ignored.
4870 if SPARK_Mode = On and then Comes_From_Source (A) then
4872 -- An effectively volatile object may act as an actual when the
4873 -- corresponding formal is of a non-scalar effectively volatile
4874 -- type (SPARK RM 7.1.3(11)).
4876 if not Is_Scalar_Type (Etype (F))
4877 and then Is_Effectively_Volatile (Etype (F))
4881 -- An effectively volatile object may act as an actual in a
4882 -- call to an instance of Unchecked_Conversion.
4883 -- (SPARK RM 7.1.3(11)).
4885 elsif Is_Unchecked_Conversion_Instance (Nam) then
4888 -- The actual denotes an object
4890 elsif Is_Effectively_Volatile_Object (A) then
4892 ("volatile object cannot act as actual in a call (SPARK "
4893 & "RM 7.1.3(11))", A);
4895 -- Otherwise the actual denotes an expression. Inspect the
4896 -- expression and flag each effectively volatile object with
4897 -- enabled property Async_Writers or Effective_Reads as illegal
4898 -- because it apprears within an interfering context. Note that
4899 -- this is usually done in Resolve_Entity_Name, but when the
4900 -- effectively volatile object appears as an actual in a call,
4901 -- the call must be resolved first.
4904 Flag_Effectively_Volatile_Objects (A);
4907 -- An effectively volatile variable cannot act as an actual
4908 -- parameter in a procedure call when the variable has enabled
4909 -- property Effective_Reads and the corresponding formal is of
4910 -- mode IN (SPARK RM 7.1.3(10)).
4912 if Ekind (Nam) = E_Procedure
4913 and then Ekind (F) = E_In_Parameter
4914 and then Is_Entity_Name (A)
4918 if Ekind (A_Id) = E_Variable
4919 and then Is_Effectively_Volatile (Etype (A_Id))
4920 and then Effective_Reads_Enabled (A_Id)
4923 ("effectively volatile variable & cannot appear as "
4924 & "actual in procedure call", A, A_Id);
4926 Error_Msg_Name_1 := Name_Effective_Reads;
4927 Error_Msg_N ("\\variable has enabled property %", A);
4928 Error_Msg_N ("\\corresponding formal has mode IN", A);
4933 -- A formal parameter of a specific tagged type whose related
4934 -- subprogram is subject to pragma Extensions_Visible with value
4935 -- "False" cannot act as an actual in a subprogram with value
4936 -- "True" (SPARK RM 6.1.7(3)).
4938 if Is_EVF_Expression (A)
4939 and then Extensions_Visible_Status (Nam) =
4940 Extensions_Visible_True
4943 ("formal parameter cannot act as actual parameter when "
4944 & "Extensions_Visible is False", A);
4946 ("\subprogram & has Extensions_Visible True", A, Nam);
4949 -- The actual parameter of a Ghost subprogram whose formal is of
4950 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4952 if Comes_From_Source (Nam)
4953 and then Is_Ghost_Entity (Nam)
4954 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4955 and then Is_Entity_Name (A)
4956 and then Present (Entity (A))
4957 and then not Is_Ghost_Entity (Entity (A))
4960 ("non-ghost variable & cannot appear as actual in call to "
4961 & "ghost procedure", A, Entity (A));
4963 if Ekind (F) = E_In_Out_Parameter then
4964 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4966 Error_Msg_N ("\corresponding formal has mode OUT", A);
4972 -- Case where actual is not present
4980 if Present (Real_Subp) then
4981 Next_Formal (Real_F);
4984 end Resolve_Actuals;
4986 -----------------------
4987 -- Resolve_Allocator --
4988 -----------------------
4990 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4991 Desig_T : constant Entity_Id := Designated_Type (Typ);
4992 E : constant Node_Id := Expression (N);
4994 Discrim : Entity_Id;
4997 Assoc : Node_Id := Empty;
5000 procedure Check_Allocator_Discrim_Accessibility
5001 (Disc_Exp : Node_Id;
5002 Alloc_Typ : Entity_Id);
5003 -- Check that accessibility level associated with an access discriminant
5004 -- initialized in an allocator by the expression Disc_Exp is not deeper
5005 -- than the level of the allocator type Alloc_Typ. An error message is
5006 -- issued if this condition is violated. Specialized checks are done for
5007 -- the cases of a constraint expression which is an access attribute or
5008 -- an access discriminant.
5010 procedure Check_Allocator_Discrim_Accessibility_Exprs
5011 (Curr_Exp : Node_Id;
5012 Alloc_Typ : Entity_Id);
5013 -- Dispatch checks performed by Check_Allocator_Discrim_Accessibility
5014 -- across all expressions within a given conditional expression.
5016 function In_Dispatching_Context return Boolean;
5017 -- If the allocator is an actual in a call, it is allowed to be class-
5018 -- wide when the context is not because it is a controlling actual.
5020 -------------------------------------------
5021 -- Check_Allocator_Discrim_Accessibility --
5022 -------------------------------------------
5024 procedure Check_Allocator_Discrim_Accessibility
5025 (Disc_Exp : Node_Id;
5026 Alloc_Typ : Entity_Id)
5029 if Type_Access_Level (Etype (Disc_Exp)) >
5030 Deepest_Type_Access_Level (Alloc_Typ)
5033 ("operand type has deeper level than allocator type", Disc_Exp);
5035 -- When the expression is an Access attribute the level of the prefix
5036 -- object must not be deeper than that of the allocator's type.
5038 elsif Nkind (Disc_Exp) = N_Attribute_Reference
5039 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
5041 and then Object_Access_Level (Prefix (Disc_Exp)) >
5042 Deepest_Type_Access_Level (Alloc_Typ)
5045 ("prefix of attribute has deeper level than allocator type",
5048 -- When the expression is an access discriminant the check is against
5049 -- the level of the prefix object.
5051 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
5052 and then Nkind (Disc_Exp) = N_Selected_Component
5053 and then Object_Access_Level (Prefix (Disc_Exp)) >
5054 Deepest_Type_Access_Level (Alloc_Typ)
5057 ("access discriminant has deeper level than allocator type",
5060 -- All other cases are legal
5065 end Check_Allocator_Discrim_Accessibility;
5067 -------------------------------------------------
5068 -- Check_Allocator_Discrim_Accessibility_Exprs --
5069 -------------------------------------------------
5071 procedure Check_Allocator_Discrim_Accessibility_Exprs
5072 (Curr_Exp : Node_Id;
5073 Alloc_Typ : Entity_Id)
5077 Disc_Exp : constant Node_Id := Original_Node (Curr_Exp);
5079 -- When conditional expressions are constant folded we know at
5080 -- compile time which expression to check - so don't bother with
5081 -- the rest of the cases.
5083 if Nkind (Curr_Exp) = N_Attribute_Reference then
5084 Check_Allocator_Discrim_Accessibility (Curr_Exp, Alloc_Typ);
5086 -- Non-constant-folded if expressions
5088 elsif Nkind (Disc_Exp) = N_If_Expression then
5089 -- Check both expressions if they are still present in the face
5092 Expr := Next (First (Expressions (Disc_Exp)));
5093 if Present (Expr) then
5094 Check_Allocator_Discrim_Accessibility_Exprs (Expr, Alloc_Typ);
5095 Expr := Next (Expr);
5096 if Present (Expr) then
5097 Check_Allocator_Discrim_Accessibility_Exprs
5102 -- Non-constant-folded case expressions
5104 elsif Nkind (Disc_Exp) = N_Case_Expression then
5105 -- Check all alternatives
5107 Alt := First (Alternatives (Disc_Exp));
5108 while Present (Alt) loop
5109 Check_Allocator_Discrim_Accessibility_Exprs
5110 (Expression (Alt), Alloc_Typ);
5115 -- Base case, check the accessibility of the original node of the
5119 Check_Allocator_Discrim_Accessibility (Disc_Exp, Alloc_Typ);
5121 end Check_Allocator_Discrim_Accessibility_Exprs;
5123 ----------------------------
5124 -- In_Dispatching_Context --
5125 ----------------------------
5127 function In_Dispatching_Context return Boolean is
5128 Par : constant Node_Id := Parent (N);
5131 return Nkind (Par) in N_Subprogram_Call
5132 and then Is_Entity_Name (Name (Par))
5133 and then Is_Dispatching_Operation (Entity (Name (Par)));
5134 end In_Dispatching_Context;
5136 -- Start of processing for Resolve_Allocator
5139 -- Replace general access with specific type
5141 if Ekind (Etype (N)) = E_Allocator_Type then
5142 Set_Etype (N, Base_Type (Typ));
5145 if Is_Abstract_Type (Typ) then
5146 Error_Msg_N ("type of allocator cannot be abstract", N);
5149 -- For qualified expression, resolve the expression using the given
5150 -- subtype (nothing to do for type mark, subtype indication)
5152 if Nkind (E) = N_Qualified_Expression then
5153 if Is_Class_Wide_Type (Etype (E))
5154 and then not Is_Class_Wide_Type (Desig_T)
5155 and then not In_Dispatching_Context
5158 ("class-wide allocator not allowed for this access type", N);
5161 Resolve (Expression (E), Etype (E));
5162 Check_Non_Static_Context (Expression (E));
5163 Check_Unset_Reference (Expression (E));
5165 -- Allocators generated by the build-in-place expansion mechanism
5166 -- are explicitly marked as coming from source but do not need to be
5167 -- checked for limited initialization. To exclude this case, ensure
5168 -- that the parent of the allocator is a source node.
5169 -- The return statement constructed for an Expression_Function does
5170 -- not come from source but requires a limited check.
5172 if Is_Limited_Type (Etype (E))
5173 and then Comes_From_Source (N)
5175 (Comes_From_Source (Parent (N))
5177 (Ekind (Current_Scope) = E_Function
5178 and then Nkind (Original_Node (Unit_Declaration_Node
5179 (Current_Scope))) = N_Expression_Function))
5180 and then not In_Instance_Body
5182 if not OK_For_Limited_Init (Etype (E), Expression (E)) then
5183 if Nkind (Parent (N)) = N_Assignment_Statement then
5185 ("illegal expression for initialized allocator of a "
5186 & "limited type (RM 7.5 (2.7/2))", N);
5189 ("initialization not allowed for limited types", N);
5192 Explain_Limited_Type (Etype (E), N);
5196 -- A qualified expression requires an exact match of the type. Class-
5197 -- wide matching is not allowed.
5199 if (Is_Class_Wide_Type (Etype (Expression (E)))
5200 or else Is_Class_Wide_Type (Etype (E)))
5201 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
5203 Wrong_Type (Expression (E), Etype (E));
5206 -- Calls to build-in-place functions are not currently supported in
5207 -- allocators for access types associated with a simple storage pool.
5208 -- Supporting such allocators may require passing additional implicit
5209 -- parameters to build-in-place functions (or a significant revision
5210 -- of the current b-i-p implementation to unify the handling for
5211 -- multiple kinds of storage pools). ???
5213 if Is_Limited_View (Desig_T)
5214 and then Nkind (Expression (E)) = N_Function_Call
5217 Pool : constant Entity_Id :=
5218 Associated_Storage_Pool (Root_Type (Typ));
5222 Present (Get_Rep_Pragma
5223 (Etype (Pool), Name_Simple_Storage_Pool_Type))
5226 ("limited function calls not yet supported in simple "
5227 & "storage pool allocators", Expression (E));
5232 -- A special accessibility check is needed for allocators that
5233 -- constrain access discriminants. The level of the type of the
5234 -- expression used to constrain an access discriminant cannot be
5235 -- deeper than the type of the allocator (in contrast to access
5236 -- parameters, where the level of the actual can be arbitrary).
5238 -- We can't use Valid_Conversion to perform this check because in
5239 -- general the type of the allocator is unrelated to the type of
5240 -- the access discriminant.
5242 if Ekind (Typ) /= E_Anonymous_Access_Type
5243 or else Is_Local_Anonymous_Access (Typ)
5245 Subtyp := Entity (Subtype_Mark (E));
5247 Aggr := Original_Node (Expression (E));
5249 if Has_Discriminants (Subtyp)
5250 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
5252 Discrim := First_Discriminant (Base_Type (Subtyp));
5254 -- Get the first component expression of the aggregate
5256 if Present (Expressions (Aggr)) then
5257 Disc_Exp := First (Expressions (Aggr));
5259 elsif Present (Component_Associations (Aggr)) then
5260 Assoc := First (Component_Associations (Aggr));
5262 if Present (Assoc) then
5263 Disc_Exp := Expression (Assoc);
5272 while Present (Discrim) and then Present (Disc_Exp) loop
5273 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
5274 Check_Allocator_Discrim_Accessibility_Exprs
5278 Next_Discriminant (Discrim);
5280 if Present (Discrim) then
5281 if Present (Assoc) then
5283 Disc_Exp := Expression (Assoc);
5285 elsif Present (Next (Disc_Exp)) then
5289 Assoc := First (Component_Associations (Aggr));
5291 if Present (Assoc) then
5292 Disc_Exp := Expression (Assoc);
5302 -- For a subtype mark or subtype indication, freeze the subtype
5305 Freeze_Expression (E);
5307 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
5309 ("initialization required for access-to-constant allocator", N);
5312 -- A special accessibility check is needed for allocators that
5313 -- constrain access discriminants. The level of the type of the
5314 -- expression used to constrain an access discriminant cannot be
5315 -- deeper than the type of the allocator (in contrast to access
5316 -- parameters, where the level of the actual can be arbitrary).
5317 -- We can't use Valid_Conversion to perform this check because
5318 -- in general the type of the allocator is unrelated to the type
5319 -- of the access discriminant.
5321 if Nkind (Original_Node (E)) = N_Subtype_Indication
5322 and then (Ekind (Typ) /= E_Anonymous_Access_Type
5323 or else Is_Local_Anonymous_Access (Typ))
5325 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
5327 if Has_Discriminants (Subtyp) then
5328 Discrim := First_Discriminant (Base_Type (Subtyp));
5329 Constr := First (Constraints (Constraint (Original_Node (E))));
5330 while Present (Discrim) and then Present (Constr) loop
5331 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
5332 if Nkind (Constr) = N_Discriminant_Association then
5333 Disc_Exp := Expression (Constr);
5338 Check_Allocator_Discrim_Accessibility_Exprs
5342 Next_Discriminant (Discrim);
5349 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
5350 -- check that the level of the type of the created object is not deeper
5351 -- than the level of the allocator's access type, since extensions can
5352 -- now occur at deeper levels than their ancestor types. This is a
5353 -- static accessibility level check; a run-time check is also needed in
5354 -- the case of an initialized allocator with a class-wide argument (see
5355 -- Expand_Allocator_Expression).
5357 if Ada_Version >= Ada_2005
5358 and then Is_Class_Wide_Type (Desig_T)
5361 Exp_Typ : Entity_Id;
5364 if Nkind (E) = N_Qualified_Expression then
5365 Exp_Typ := Etype (E);
5366 elsif Nkind (E) = N_Subtype_Indication then
5367 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
5369 Exp_Typ := Entity (E);
5372 if Type_Access_Level (Exp_Typ) >
5373 Deepest_Type_Access_Level (Typ)
5375 if In_Instance_Body then
5376 Error_Msg_Warn := SPARK_Mode /= On;
5378 ("type in allocator has deeper level than designated "
5379 & "class-wide type<<", E);
5380 Error_Msg_N ("\Program_Error [<<", E);
5383 Make_Raise_Program_Error (Sloc (N),
5384 Reason => PE_Accessibility_Check_Failed));
5387 -- Do not apply Ada 2005 accessibility checks on a class-wide
5388 -- allocator if the type given in the allocator is a formal
5389 -- type. A run-time check will be performed in the instance.
5391 elsif not Is_Generic_Type (Exp_Typ) then
5393 ("type in allocator has deeper level than designated "
5394 & "class-wide type", E);
5400 -- Check for allocation from an empty storage pool. But do not complain
5401 -- if it's a return statement for a build-in-place function, because the
5402 -- allocator is there just in case the caller uses an allocator. If the
5403 -- caller does use an allocator, it will be caught at the call site.
5405 if No_Pool_Assigned (Typ)
5406 and then not Alloc_For_BIP_Return (N)
5408 Error_Msg_N ("allocation from empty storage pool!", N);
5410 -- If the context is an unchecked conversion, as may happen within an
5411 -- inlined subprogram, the allocator is being resolved with its own
5412 -- anonymous type. In that case, if the target type has a specific
5413 -- storage pool, it must be inherited explicitly by the allocator type.
5415 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
5416 and then No (Associated_Storage_Pool (Typ))
5418 Set_Associated_Storage_Pool
5419 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
5422 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
5423 Check_Restriction (No_Anonymous_Allocators, N);
5426 -- Check that an allocator with task parts isn't for a nested access
5427 -- type when restriction No_Task_Hierarchy applies.
5429 if not Is_Library_Level_Entity (Base_Type (Typ))
5430 and then Has_Task (Base_Type (Desig_T))
5432 Check_Restriction (No_Task_Hierarchy, N);
5435 -- An illegal allocator may be rewritten as a raise Program_Error
5438 if Nkind (N) = N_Allocator then
5440 -- Avoid coextension processing for an allocator that is the
5441 -- expansion of a build-in-place function call.
5443 if Nkind (Original_Node (N)) = N_Allocator
5444 and then Nkind (Expression (Original_Node (N))) =
5445 N_Qualified_Expression
5446 and then Nkind (Expression (Expression (Original_Node (N)))) =
5448 and then Is_Expanded_Build_In_Place_Call
5449 (Expression (Expression (Original_Node (N))))
5451 null; -- b-i-p function call case
5454 -- An anonymous access discriminant is the definition of a
5457 if Ekind (Typ) = E_Anonymous_Access_Type
5458 and then Nkind (Associated_Node_For_Itype (Typ)) =
5459 N_Discriminant_Specification
5462 Discr : constant Entity_Id :=
5463 Defining_Identifier (Associated_Node_For_Itype (Typ));
5466 Check_Restriction (No_Coextensions, N);
5468 -- Ada 2012 AI05-0052: If the designated type of the
5469 -- allocator is limited, then the allocator shall not
5470 -- be used to define the value of an access discriminant
5471 -- unless the discriminated type is immutably limited.
5473 if Ada_Version >= Ada_2012
5474 and then Is_Limited_Type (Desig_T)
5475 and then not Is_Limited_View (Scope (Discr))
5478 ("only immutably limited types can have anonymous "
5479 & "access discriminants designating a limited type",
5484 -- Avoid marking an allocator as a dynamic coextension if it is
5485 -- within a static construct.
5487 if not Is_Static_Coextension (N) then
5488 Set_Is_Dynamic_Coextension (N);
5490 -- Finalization and deallocation of coextensions utilizes an
5491 -- approximate implementation which does not directly adhere
5492 -- to the semantic rules. Warn on potential issues involving
5495 if Is_Controlled (Desig_T) then
5497 ("??coextension will not be finalized when its "
5498 & "associated owner is deallocated or finalized", N);
5501 ("??coextension will not be deallocated when its "
5502 & "associated owner is deallocated", N);
5506 -- Cleanup for potential static coextensions
5509 Set_Is_Dynamic_Coextension (N, False);
5510 Set_Is_Static_Coextension (N, False);
5512 -- Anonymous access-to-controlled objects are not finalized on
5513 -- time because this involves run-time ownership and currently
5514 -- this property is not available. In rare cases the object may
5515 -- not be finalized at all. Warn on potential issues involving
5516 -- anonymous access-to-controlled objects.
5518 if Ekind (Typ) = E_Anonymous_Access_Type
5519 and then Is_Controlled_Active (Desig_T)
5522 ("??object designated by anonymous access object might "
5523 & "not be finalized until its enclosing library unit "
5524 & "goes out of scope", N);
5525 Error_Msg_N ("\use named access type instead", N);
5531 -- Report a simple error: if the designated object is a local task,
5532 -- its body has not been seen yet, and its activation will fail an
5533 -- elaboration check.
5535 if Is_Task_Type (Desig_T)
5536 and then Scope (Base_Type (Desig_T)) = Current_Scope
5537 and then Is_Compilation_Unit (Current_Scope)
5538 and then Ekind (Current_Scope) = E_Package
5539 and then not In_Package_Body (Current_Scope)
5541 Error_Msg_Warn := SPARK_Mode /= On;
5542 Error_Msg_N ("cannot activate task before body seen<<", N);
5543 Error_Msg_N ("\Program_Error [<<", N);
5546 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5547 -- type with a task component on a subpool. This action must raise
5548 -- Program_Error at runtime.
5550 if Ada_Version >= Ada_2012
5551 and then Nkind (N) = N_Allocator
5552 and then Present (Subpool_Handle_Name (N))
5553 and then Has_Task (Desig_T)
5555 Error_Msg_Warn := SPARK_Mode /= On;
5556 Error_Msg_N ("cannot allocate task on subpool<<", N);
5557 Error_Msg_N ("\Program_Error [<<", N);
5560 Make_Raise_Program_Error (Sloc (N),
5561 Reason => PE_Explicit_Raise));
5564 end Resolve_Allocator;
5566 ---------------------------
5567 -- Resolve_Arithmetic_Op --
5568 ---------------------------
5570 -- Used for resolving all arithmetic operators except exponentiation
5572 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5573 L : constant Node_Id := Left_Opnd (N);
5574 R : constant Node_Id := Right_Opnd (N);
5575 TL : constant Entity_Id := Base_Type (Etype (L));
5576 TR : constant Entity_Id := Base_Type (Etype (R));
5580 B_Typ : constant Entity_Id := Base_Type (Typ);
5581 -- We do the resolution using the base type, because intermediate values
5582 -- in expressions always are of the base type, not a subtype of it.
5584 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5585 -- Returns True if N is in a context that expects "any real type"
5587 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5588 -- Return True iff given type is Integer or universal real/integer
5590 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5591 -- Choose type of integer literal in fixed-point operation to conform
5592 -- to available fixed-point type. T is the type of the other operand,
5593 -- which is needed to determine the expected type of N.
5595 procedure Set_Operand_Type (N : Node_Id);
5596 -- Set operand type to T if universal
5598 -------------------------------
5599 -- Expected_Type_Is_Any_Real --
5600 -------------------------------
5602 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5604 -- N is the expression after "delta" in a fixed_point_definition;
5607 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5608 N_Decimal_Fixed_Point_Definition,
5610 -- N is one of the bounds in a real_range_specification;
5613 N_Real_Range_Specification,
5615 -- N is the expression of a delta_constraint;
5618 N_Delta_Constraint);
5619 end Expected_Type_Is_Any_Real;
5621 -----------------------------
5622 -- Is_Integer_Or_Universal --
5623 -----------------------------
5625 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5627 Index : Interp_Index;
5631 if not Is_Overloaded (N) then
5633 return Base_Type (T) = Base_Type (Standard_Integer)
5634 or else T = Universal_Integer
5635 or else T = Universal_Real;
5637 Get_First_Interp (N, Index, It);
5638 while Present (It.Typ) loop
5639 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5640 or else It.Typ = Universal_Integer
5641 or else It.Typ = Universal_Real
5646 Get_Next_Interp (Index, It);
5651 end Is_Integer_Or_Universal;
5653 ----------------------------
5654 -- Set_Mixed_Mode_Operand --
5655 ----------------------------
5657 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5658 Index : Interp_Index;
5662 if Universal_Interpretation (N) = Universal_Integer then
5664 -- A universal integer literal is resolved as standard integer
5665 -- except in the case of a fixed-point result, where we leave it
5666 -- as universal (to be handled by Exp_Fixd later on)
5668 if Is_Fixed_Point_Type (T) then
5669 Resolve (N, Universal_Integer);
5671 Resolve (N, Standard_Integer);
5674 elsif Universal_Interpretation (N) = Universal_Real
5675 and then (T = Base_Type (Standard_Integer)
5676 or else T = Universal_Integer
5677 or else T = Universal_Real)
5679 -- A universal real can appear in a fixed-type context. We resolve
5680 -- the literal with that context, even though this might raise an
5681 -- exception prematurely (the other operand may be zero).
5685 elsif Etype (N) = Base_Type (Standard_Integer)
5686 and then T = Universal_Real
5687 and then Is_Overloaded (N)
5689 -- Integer arg in mixed-mode operation. Resolve with universal
5690 -- type, in case preference rule must be applied.
5692 Resolve (N, Universal_Integer);
5694 elsif Etype (N) = T and then B_Typ /= Universal_Fixed then
5696 -- If the operand is part of a fixed multiplication operation,
5697 -- a conversion will be applied to each operand, so resolve it
5698 -- with its own type.
5700 if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then
5704 -- Not a mixed-mode operation, resolve with context
5709 elsif Etype (N) = Any_Fixed then
5711 -- N may itself be a mixed-mode operation, so use context type
5715 elsif Is_Fixed_Point_Type (T)
5716 and then B_Typ = Universal_Fixed
5717 and then Is_Overloaded (N)
5719 -- Must be (fixed * fixed) operation, operand must have one
5720 -- compatible interpretation.
5722 Resolve (N, Any_Fixed);
5724 elsif Is_Fixed_Point_Type (B_Typ)
5725 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5726 and then Is_Overloaded (N)
5728 -- C * F(X) in a fixed context, where C is a real literal or a
5729 -- fixed-point expression. F must have either a fixed type
5730 -- interpretation or an integer interpretation, but not both.
5732 Get_First_Interp (N, Index, It);
5733 while Present (It.Typ) loop
5734 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5735 if Analyzed (N) then
5736 Error_Msg_N ("ambiguous operand in fixed operation", N);
5738 Resolve (N, Standard_Integer);
5741 elsif Is_Fixed_Point_Type (It.Typ) then
5742 if Analyzed (N) then
5743 Error_Msg_N ("ambiguous operand in fixed operation", N);
5745 Resolve (N, It.Typ);
5749 Get_Next_Interp (Index, It);
5752 -- Reanalyze the literal with the fixed type of the context. If
5753 -- context is Universal_Fixed, we are within a conversion, leave
5754 -- the literal as a universal real because there is no usable
5755 -- fixed type, and the target of the conversion plays no role in
5769 if B_Typ = Universal_Fixed
5770 and then Nkind (Op2) = N_Real_Literal
5772 T2 := Universal_Real;
5777 Set_Analyzed (Op2, False);
5781 -- A universal real conditional expression can appear in a fixed-type
5782 -- context and must be resolved with that context to facilitate the
5783 -- code generation in the back end. However, If the context is
5784 -- Universal_fixed (i.e. as an operand of a multiplication/division
5785 -- involving a fixed-point operand) the conditional expression must
5786 -- resolve to a unique visible fixed_point type, normally Duration.
5788 elsif Nkind_In (N, N_Case_Expression, N_If_Expression)
5789 and then Etype (N) = Universal_Real
5790 and then Is_Fixed_Point_Type (B_Typ)
5792 if B_Typ = Universal_Fixed then
5793 Resolve (N, Unique_Fixed_Point_Type (N));
5802 end Set_Mixed_Mode_Operand;
5804 ----------------------
5805 -- Set_Operand_Type --
5806 ----------------------
5808 procedure Set_Operand_Type (N : Node_Id) is
5810 if Etype (N) = Universal_Integer
5811 or else Etype (N) = Universal_Real
5815 end Set_Operand_Type;
5817 -- Start of processing for Resolve_Arithmetic_Op
5820 if Comes_From_Source (N)
5821 and then Ekind (Entity (N)) = E_Function
5822 and then Is_Imported (Entity (N))
5823 and then Is_Intrinsic_Subprogram (Entity (N))
5825 Resolve_Intrinsic_Operator (N, Typ);
5828 -- Special-case for mixed-mode universal expressions or fixed point type
5829 -- operation: each argument is resolved separately. The same treatment
5830 -- is required if one of the operands of a fixed point operation is
5831 -- universal real, since in this case we don't do a conversion to a
5832 -- specific fixed-point type (instead the expander handles the case).
5834 -- Set the type of the node to its universal interpretation because
5835 -- legality checks on an exponentiation operand need the context.
5837 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5838 and then Present (Universal_Interpretation (L))
5839 and then Present (Universal_Interpretation (R))
5841 Set_Etype (N, B_Typ);
5842 Resolve (L, Universal_Interpretation (L));
5843 Resolve (R, Universal_Interpretation (R));
5845 elsif (B_Typ = Universal_Real
5846 or else Etype (N) = Universal_Fixed
5847 or else (Etype (N) = Any_Fixed
5848 and then Is_Fixed_Point_Type (B_Typ))
5849 or else (Is_Fixed_Point_Type (B_Typ)
5850 and then (Is_Integer_Or_Universal (L)
5852 Is_Integer_Or_Universal (R))))
5853 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5855 if TL = Universal_Integer or else TR = Universal_Integer then
5856 Check_For_Visible_Operator (N, B_Typ);
5859 -- If context is a fixed type and one operand is integer, the other
5860 -- is resolved with the type of the context.
5862 if Is_Fixed_Point_Type (B_Typ)
5863 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5864 or else TL = Universal_Integer)
5869 elsif Is_Fixed_Point_Type (B_Typ)
5870 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5871 or else TR = Universal_Integer)
5876 -- If both operands are universal and the context is a floating
5877 -- point type, the operands are resolved to the type of the context.
5879 elsif Is_Floating_Point_Type (B_Typ) then
5884 Set_Mixed_Mode_Operand (L, TR);
5885 Set_Mixed_Mode_Operand (R, TL);
5888 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5889 -- multiplying operators from being used when the expected type is
5890 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5891 -- some cases where the expected type is actually Any_Real;
5892 -- Expected_Type_Is_Any_Real takes care of that case.
5894 if Etype (N) = Universal_Fixed
5895 or else Etype (N) = Any_Fixed
5897 if B_Typ = Universal_Fixed
5898 and then not Expected_Type_Is_Any_Real (N)
5899 and then not Nkind_In (Parent (N), N_Type_Conversion,
5900 N_Unchecked_Type_Conversion)
5902 Error_Msg_N ("type cannot be determined from context!", N);
5903 Error_Msg_N ("\explicit conversion to result type required", N);
5905 Set_Etype (L, Any_Type);
5906 Set_Etype (R, Any_Type);
5909 if Ada_Version = Ada_83
5910 and then Etype (N) = Universal_Fixed
5912 Nkind_In (Parent (N), N_Type_Conversion,
5913 N_Unchecked_Type_Conversion)
5916 ("(Ada 83) fixed-point operation needs explicit "
5920 -- The expected type is "any real type" in contexts like
5922 -- type T is delta <universal_fixed-expression> ...
5924 -- in which case we need to set the type to Universal_Real
5925 -- so that static expression evaluation will work properly.
5927 if Expected_Type_Is_Any_Real (N) then
5928 Set_Etype (N, Universal_Real);
5930 Set_Etype (N, B_Typ);
5934 elsif Is_Fixed_Point_Type (B_Typ)
5935 and then (Is_Integer_Or_Universal (L)
5936 or else Nkind (L) = N_Real_Literal
5937 or else Nkind (R) = N_Real_Literal
5938 or else Is_Integer_Or_Universal (R))
5940 Set_Etype (N, B_Typ);
5942 elsif Etype (N) = Any_Fixed then
5944 -- If no previous errors, this is only possible if one operand is
5945 -- overloaded and the context is universal. Resolve as such.
5947 Set_Etype (N, B_Typ);
5951 if (TL = Universal_Integer or else TL = Universal_Real)
5953 (TR = Universal_Integer or else TR = Universal_Real)
5955 Check_For_Visible_Operator (N, B_Typ);
5958 -- If the context is Universal_Fixed and the operands are also
5959 -- universal fixed, this is an error, unless there is only one
5960 -- applicable fixed_point type (usually Duration).
5962 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5963 T := Unique_Fixed_Point_Type (N);
5965 if T = Any_Type then
5978 -- If one of the arguments was resolved to a non-universal type.
5979 -- label the result of the operation itself with the same type.
5980 -- Do the same for the universal argument, if any.
5982 T := Intersect_Types (L, R);
5983 Set_Etype (N, Base_Type (T));
5984 Set_Operand_Type (L);
5985 Set_Operand_Type (R);
5988 Generate_Operator_Reference (N, Typ);
5989 Analyze_Dimension (N);
5990 Eval_Arithmetic_Op (N);
5992 -- In SPARK, a multiplication or division with operands of fixed point
5993 -- types must be qualified or explicitly converted to identify the
5996 if (Is_Fixed_Point_Type (Etype (L))
5997 or else Is_Fixed_Point_Type (Etype (R)))
5998 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
6000 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
6002 Check_SPARK_05_Restriction
6003 ("operation should be qualified or explicitly converted", N);
6006 -- Set overflow and division checking bit
6008 if Nkind (N) in N_Op then
6009 if not Overflow_Checks_Suppressed (Etype (N)) then
6010 Enable_Overflow_Check (N);
6013 -- Give warning if explicit division by zero
6015 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
6016 and then not Division_Checks_Suppressed (Etype (N))
6018 Rop := Right_Opnd (N);
6020 if Compile_Time_Known_Value (Rop)
6021 and then ((Is_Integer_Type (Etype (Rop))
6022 and then Expr_Value (Rop) = Uint_0)
6024 (Is_Real_Type (Etype (Rop))
6025 and then Expr_Value_R (Rop) = Ureal_0))
6027 -- Specialize the warning message according to the operation.
6028 -- When SPARK_Mode is On, force a warning instead of an error
6029 -- in that case, as this likely corresponds to deactivated
6030 -- code. The following warnings are for the case
6035 -- For division, we have two cases, for float division
6036 -- of an unconstrained float type, on a machine where
6037 -- Machine_Overflows is false, we don't get an exception
6038 -- at run-time, but rather an infinity or Nan. The Nan
6039 -- case is pretty obscure, so just warn about infinities.
6041 if Is_Floating_Point_Type (Typ)
6042 and then not Is_Constrained (Typ)
6043 and then not Machine_Overflows_On_Target
6046 ("float division by zero, may generate "
6047 & "'+'/'- infinity??", Right_Opnd (N));
6049 -- For all other cases, we get a Constraint_Error
6052 Apply_Compile_Time_Constraint_Error
6053 (N, "division by zero??", CE_Divide_By_Zero,
6054 Loc => Sloc (Right_Opnd (N)),
6055 Warn => SPARK_Mode = On);
6059 Apply_Compile_Time_Constraint_Error
6060 (N, "rem with zero divisor??", CE_Divide_By_Zero,
6061 Loc => Sloc (Right_Opnd (N)),
6062 Warn => SPARK_Mode = On);
6065 Apply_Compile_Time_Constraint_Error
6066 (N, "mod with zero divisor??", CE_Divide_By_Zero,
6067 Loc => Sloc (Right_Opnd (N)),
6068 Warn => SPARK_Mode = On);
6070 -- Division by zero can only happen with division, rem,
6071 -- and mod operations.
6074 raise Program_Error;
6077 -- In GNATprove mode, we enable the division check so that
6078 -- GNATprove will issue a message if it cannot be proved.
6080 if GNATprove_Mode then
6081 Activate_Division_Check (N);
6084 -- Otherwise just set the flag to check at run time
6087 Activate_Division_Check (N);
6091 -- If Restriction No_Implicit_Conditionals is active, then it is
6092 -- violated if either operand can be negative for mod, or for rem
6093 -- if both operands can be negative.
6095 if Restriction_Check_Required (No_Implicit_Conditionals)
6096 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
6105 -- Set if corresponding operand might be negative
6109 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
6110 LNeg := (not OK) or else Lo < 0;
6113 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
6114 RNeg := (not OK) or else Lo < 0;
6116 -- Check if we will be generating conditionals. There are two
6117 -- cases where that can happen, first for REM, the only case
6118 -- is largest negative integer mod -1, where the division can
6119 -- overflow, but we still have to give the right result. The
6120 -- front end generates a test for this annoying case. Here we
6121 -- just test if both operands can be negative (that's what the
6122 -- expander does, so we match its logic here).
6124 -- The second case is mod where either operand can be negative.
6125 -- In this case, the back end has to generate additional tests.
6127 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
6129 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
6131 Check_Restriction (No_Implicit_Conditionals, N);
6137 Check_Unset_Reference (L);
6138 Check_Unset_Reference (R);
6139 end Resolve_Arithmetic_Op;
6145 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
6146 function Same_Or_Aliased_Subprograms
6148 E : Entity_Id) return Boolean;
6149 -- Returns True if the subprogram entity S is the same as E or else
6150 -- S is an alias of E.
6152 ---------------------------------
6153 -- Same_Or_Aliased_Subprograms --
6154 ---------------------------------
6156 function Same_Or_Aliased_Subprograms
6158 E : Entity_Id) return Boolean
6160 Subp_Alias : constant Entity_Id := Alias (S);
6162 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
6163 end Same_Or_Aliased_Subprograms;
6167 Loc : constant Source_Ptr := Sloc (N);
6168 Subp : constant Node_Id := Name (N);
6169 Body_Id : Entity_Id;
6179 -- Start of processing for Resolve_Call
6182 -- Preserve relevant elaboration-related attributes of the context which
6183 -- are no longer available or very expensive to recompute once analysis,
6184 -- resolution, and expansion are over.
6186 Mark_Elaboration_Attributes
6192 -- The context imposes a unique interpretation with type Typ on a
6193 -- procedure or function call. Find the entity of the subprogram that
6194 -- yields the expected type, and propagate the corresponding formal
6195 -- constraints on the actuals. The caller has established that an
6196 -- interpretation exists, and emitted an error if not unique.
6198 -- First deal with the case of a call to an access-to-subprogram,
6199 -- dereference made explicit in Analyze_Call.
6201 if Ekind (Etype (Subp)) = E_Subprogram_Type then
6202 if not Is_Overloaded (Subp) then
6203 Nam := Etype (Subp);
6206 -- Find the interpretation whose type (a subprogram type) has a
6207 -- return type that is compatible with the context. Analysis of
6208 -- the node has established that one exists.
6212 Get_First_Interp (Subp, I, It);
6213 while Present (It.Typ) loop
6214 if Covers (Typ, Etype (It.Typ)) then
6219 Get_Next_Interp (I, It);
6223 raise Program_Error;
6227 -- If the prefix is not an entity, then resolve it
6229 if not Is_Entity_Name (Subp) then
6230 Resolve (Subp, Nam);
6233 -- For an indirect call, we always invalidate checks, since we do not
6234 -- know whether the subprogram is local or global. Yes we could do
6235 -- better here, e.g. by knowing that there are no local subprograms,
6236 -- but it does not seem worth the effort. Similarly, we kill all
6237 -- knowledge of current constant values.
6239 Kill_Current_Values;
6241 -- If this is a procedure call which is really an entry call, do
6242 -- the conversion of the procedure call to an entry call. Protected
6243 -- operations use the same circuitry because the name in the call
6244 -- can be an arbitrary expression with special resolution rules.
6246 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
6247 or else (Is_Entity_Name (Subp)
6248 and then Ekind_In (Entity (Subp), E_Entry, E_Entry_Family))
6250 Resolve_Entry_Call (N, Typ);
6252 if Legacy_Elaboration_Checks then
6253 Check_Elab_Call (N);
6256 -- Annotate the tree by creating a call marker in case the original
6257 -- call is transformed by expansion. The call marker is automatically
6258 -- saved for later examination by the ABE Processing phase.
6260 Build_Call_Marker (N);
6262 -- Kill checks and constant values, as above for indirect case
6263 -- Who knows what happens when another task is activated?
6265 Kill_Current_Values;
6268 -- Normal subprogram call with name established in Resolve
6270 elsif not (Is_Type (Entity (Subp))) then
6271 Nam := Entity (Subp);
6272 Set_Entity_With_Checks (Subp, Nam);
6274 -- Otherwise we must have the case of an overloaded call
6277 pragma Assert (Is_Overloaded (Subp));
6279 -- Initialize Nam to prevent warning (we know it will be assigned
6280 -- in the loop below, but the compiler does not know that).
6284 Get_First_Interp (Subp, I, It);
6285 while Present (It.Typ) loop
6286 if Covers (Typ, It.Typ) then
6288 Set_Entity_With_Checks (Subp, Nam);
6292 Get_Next_Interp (I, It);
6296 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
6297 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
6298 and then Nkind (Subp) /= N_Explicit_Dereference
6299 and then Present (Parameter_Associations (N))
6301 -- The prefix is a parameterless function call that returns an access
6302 -- to subprogram. If parameters are present in the current call, add
6303 -- add an explicit dereference. We use the base type here because
6304 -- within an instance these may be subtypes.
6306 -- The dereference is added either in Analyze_Call or here. Should
6307 -- be consolidated ???
6309 Set_Is_Overloaded (Subp, False);
6310 Set_Etype (Subp, Etype (Nam));
6311 Insert_Explicit_Dereference (Subp);
6312 Nam := Designated_Type (Etype (Nam));
6313 Resolve (Subp, Nam);
6316 -- Check that a call to Current_Task does not occur in an entry body
6318 if Is_RTE (Nam, RE_Current_Task) then
6327 -- Exclude calls that occur within the default of a formal
6328 -- parameter of the entry, since those are evaluated outside
6331 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
6333 if Nkind (P) = N_Entry_Body
6334 or else (Nkind (P) = N_Subprogram_Body
6335 and then Is_Entry_Barrier_Function (P))
6338 Error_Msg_Warn := SPARK_Mode /= On;
6340 ("& should not be used in entry body (RM C.7(17))<<",
6342 Error_Msg_NE ("\Program_Error [<<", N, Nam);
6344 Make_Raise_Program_Error (Loc,
6345 Reason => PE_Current_Task_In_Entry_Body));
6346 Set_Etype (N, Rtype);
6353 -- Check that a procedure call does not occur in the context of the
6354 -- entry call statement of a conditional or timed entry call. Note that
6355 -- the case of a call to a subprogram renaming of an entry will also be
6356 -- rejected. The test for N not being an N_Entry_Call_Statement is
6357 -- defensive, covering the possibility that the processing of entry
6358 -- calls might reach this point due to later modifications of the code
6361 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6362 and then Nkind (N) /= N_Entry_Call_Statement
6363 and then Entry_Call_Statement (Parent (N)) = N
6365 if Ada_Version < Ada_2005 then
6366 Error_Msg_N ("entry call required in select statement", N);
6368 -- Ada 2005 (AI-345): If a procedure_call_statement is used
6369 -- for a procedure_or_entry_call, the procedure_name or
6370 -- procedure_prefix of the procedure_call_statement shall denote
6371 -- an entry renamed by a procedure, or (a view of) a primitive
6372 -- subprogram of a limited interface whose first parameter is
6373 -- a controlling parameter.
6375 elsif Nkind (N) = N_Procedure_Call_Statement
6376 and then not Is_Renamed_Entry (Nam)
6377 and then not Is_Controlling_Limited_Procedure (Nam)
6380 ("entry call or dispatching primitive of interface required", N);
6384 -- If the SPARK_05 restriction is active, we are not allowed
6385 -- to have a call to a subprogram before we see its completion.
6387 if not Has_Completion (Nam)
6388 and then Restriction_Check_Required (SPARK_05)
6390 -- Don't flag strange internal calls
6392 and then Comes_From_Source (N)
6393 and then Comes_From_Source (Nam)
6395 -- Only flag calls in extended main source
6397 and then In_Extended_Main_Source_Unit (Nam)
6398 and then In_Extended_Main_Source_Unit (N)
6400 -- Exclude enumeration literals from this processing
6402 and then Ekind (Nam) /= E_Enumeration_Literal
6404 Check_SPARK_05_Restriction
6405 ("call to subprogram cannot appear before its body", N);
6408 -- Check that this is not a call to a protected procedure or entry from
6409 -- within a protected function.
6411 Check_Internal_Protected_Use (N, Nam);
6413 -- Freeze the subprogram name if not in a spec-expression. Note that
6414 -- we freeze procedure calls as well as function calls. Procedure calls
6415 -- are not frozen according to the rules (RM 13.14(14)) because it is
6416 -- impossible to have a procedure call to a non-frozen procedure in
6417 -- pure Ada, but in the code that we generate in the expander, this
6418 -- rule needs extending because we can generate procedure calls that
6421 -- In Ada 2012, expression functions may be called within pre/post
6422 -- conditions of subsequent functions or expression functions. Such
6423 -- calls do not freeze when they appear within generated bodies,
6424 -- (including the body of another expression function) which would
6425 -- place the freeze node in the wrong scope. An expression function
6426 -- is frozen in the usual fashion, by the appearance of a real body,
6427 -- or at the end of a declarative part. However an implicit call to
6428 -- an expression function may appear when it is part of a default
6429 -- expression in a call to an initialization procedure, and must be
6430 -- frozen now, even if the body is inserted at a later point.
6431 -- Otherwise, the call freezes the expression if expander is active,
6432 -- for example as part of an object declaration.
6434 if Is_Entity_Name (Subp)
6435 and then not In_Spec_Expression
6436 and then not Is_Expression_Function_Or_Completion (Current_Scope)
6438 (not Is_Expression_Function_Or_Completion (Entity (Subp))
6439 or else Expander_Active)
6441 if Is_Expression_Function (Entity (Subp)) then
6443 -- Force freeze of expression function in call
6445 Set_Comes_From_Source (Subp, True);
6446 Set_Must_Not_Freeze (Subp, False);
6449 Freeze_Expression (Subp);
6452 -- For a predefined operator, the type of the result is the type imposed
6453 -- by context, except for a predefined operation on universal fixed.
6454 -- Otherwise the type of the call is the type returned by the subprogram
6457 if Is_Predefined_Op (Nam) then
6458 if Etype (N) /= Universal_Fixed then
6462 -- If the subprogram returns an array type, and the context requires the
6463 -- component type of that array type, the node is really an indexing of
6464 -- the parameterless call. Resolve as such. A pathological case occurs
6465 -- when the type of the component is an access to the array type. In
6466 -- this case the call is truly ambiguous. If the call is to an intrinsic
6467 -- subprogram, it can't be an indexed component. This check is necessary
6468 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
6469 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
6470 -- pointers to the same array), the compiler gets confused and does an
6471 -- infinite recursion.
6473 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
6475 ((Is_Array_Type (Etype (Nam))
6476 and then Covers (Typ, Component_Type (Etype (Nam))))
6478 (Is_Access_Type (Etype (Nam))
6479 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6481 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))
6482 and then not Is_Intrinsic_Subprogram (Entity (Subp))))
6485 Index_Node : Node_Id;
6487 Ret_Type : constant Entity_Id := Etype (Nam);
6490 -- If this is a parameterless call there is no ambiguity and the
6491 -- call has the type of the function.
6493 if No (First_Actual (N)) then
6494 Set_Etype (N, Etype (Nam));
6496 if Present (First_Formal (Nam)) then
6497 Resolve_Actuals (N, Nam);
6500 -- Annotate the tree by creating a call marker in case the
6501 -- original call is transformed by expansion. The call marker
6502 -- is automatically saved for later examination by the ABE
6503 -- Processing phase.
6505 Build_Call_Marker (N);
6507 elsif Is_Access_Type (Ret_Type)
6509 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
6512 ("cannot disambiguate function call and indexing", N);
6514 New_Subp := Relocate_Node (Subp);
6516 -- The called entity may be an explicit dereference, in which
6517 -- case there is no entity to set.
6519 if Nkind (New_Subp) /= N_Explicit_Dereference then
6520 Set_Entity (Subp, Nam);
6523 if (Is_Array_Type (Ret_Type)
6524 and then Component_Type (Ret_Type) /= Any_Type)
6526 (Is_Access_Type (Ret_Type)
6528 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
6530 if Needs_No_Actuals (Nam) then
6532 -- Indexed call to a parameterless function
6535 Make_Indexed_Component (Loc,
6537 Make_Function_Call (Loc, Name => New_Subp),
6538 Expressions => Parameter_Associations (N));
6540 -- An Ada 2005 prefixed call to a primitive operation
6541 -- whose first parameter is the prefix. This prefix was
6542 -- prepended to the parameter list, which is actually a
6543 -- list of indexes. Remove the prefix in order to build
6544 -- the proper indexed component.
6547 Make_Indexed_Component (Loc,
6549 Make_Function_Call (Loc,
6551 Parameter_Associations =>
6553 (Remove_Head (Parameter_Associations (N)))),
6554 Expressions => Parameter_Associations (N));
6557 -- Preserve the parenthesis count of the node
6559 Set_Paren_Count (Index_Node, Paren_Count (N));
6561 -- Since we are correcting a node classification error made
6562 -- by the parser, we call Replace rather than Rewrite.
6564 Replace (N, Index_Node);
6566 Set_Etype (Prefix (N), Ret_Type);
6568 Resolve_Indexed_Component (N, Typ);
6570 if Legacy_Elaboration_Checks then
6571 Check_Elab_Call (Prefix (N));
6574 -- Annotate the tree by creating a call marker in case
6575 -- the original call is transformed by expansion. The call
6576 -- marker is automatically saved for later examination by
6577 -- the ABE Processing phase.
6579 Build_Call_Marker (Prefix (N));
6587 -- If the called function is not declared in the main unit and it
6588 -- returns the limited view of type then use the available view (as
6589 -- is done in Try_Object_Operation) to prevent back-end confusion;
6590 -- for the function entity itself. The call must appear in a context
6591 -- where the nonlimited view is available. If the function entity is
6592 -- in the extended main unit then no action is needed, because the
6593 -- back end handles this case. In either case the type of the call
6594 -- is the nonlimited view.
6596 if From_Limited_With (Etype (Nam))
6597 and then Present (Available_View (Etype (Nam)))
6599 Set_Etype (N, Available_View (Etype (Nam)));
6601 if not In_Extended_Main_Code_Unit (Nam) then
6602 Set_Etype (Nam, Available_View (Etype (Nam)));
6606 Set_Etype (N, Etype (Nam));
6610 -- In the case where the call is to an overloaded subprogram, Analyze
6611 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6612 -- such a case Normalize_Actuals needs to be called once more to order
6613 -- the actuals correctly. Otherwise the call will have the ordering
6614 -- given by the last overloaded subprogram whether this is the correct
6615 -- one being called or not.
6617 if Is_Overloaded (Subp) then
6618 Normalize_Actuals (N, Nam, False, Norm_OK);
6619 pragma Assert (Norm_OK);
6622 -- In any case, call is fully resolved now. Reset Overload flag, to
6623 -- prevent subsequent overload resolution if node is analyzed again
6625 Set_Is_Overloaded (Subp, False);
6626 Set_Is_Overloaded (N, False);
6628 -- A Ghost entity must appear in a specific context
6630 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6631 Check_Ghost_Context (Nam, N);
6634 -- If we are calling the current subprogram from immediately within its
6635 -- body, then that is the case where we can sometimes detect cases of
6636 -- infinite recursion statically. Do not try this in case restriction
6637 -- No_Recursion is in effect anyway, and do it only for source calls.
6639 if Comes_From_Source (N) then
6640 Scop := Current_Scope;
6642 -- Check violation of SPARK_05 restriction which does not permit
6643 -- a subprogram body to contain a call to the subprogram directly.
6645 if Restriction_Check_Required (SPARK_05)
6646 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6648 Check_SPARK_05_Restriction
6649 ("subprogram may not contain direct call to itself", N);
6652 -- Issue warning for possible infinite recursion in the absence
6653 -- of the No_Recursion restriction.
6655 if Same_Or_Aliased_Subprograms (Nam, Scop)
6656 and then not Restriction_Active (No_Recursion)
6657 and then Check_Infinite_Recursion (N)
6659 -- Here we detected and flagged an infinite recursion, so we do
6660 -- not need to test the case below for further warnings. Also we
6661 -- are all done if we now have a raise SE node.
6663 if Nkind (N) = N_Raise_Storage_Error then
6667 -- If call is to immediately containing subprogram, then check for
6668 -- the case of a possible run-time detectable infinite recursion.
6671 Scope_Loop : while Scop /= Standard_Standard loop
6672 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6674 -- Although in general case, recursion is not statically
6675 -- checkable, the case of calling an immediately containing
6676 -- subprogram is easy to catch.
6678 if not Is_Ignored_Ghost_Entity (Nam) then
6679 Check_Restriction (No_Recursion, N);
6682 -- If the recursive call is to a parameterless subprogram,
6683 -- then even if we can't statically detect infinite
6684 -- recursion, this is pretty suspicious, and we output a
6685 -- warning. Furthermore, we will try later to detect some
6686 -- cases here at run time by expanding checking code (see
6687 -- Detect_Infinite_Recursion in package Exp_Ch6).
6689 -- If the recursive call is within a handler, do not emit a
6690 -- warning, because this is a common idiom: loop until input
6691 -- is correct, catch illegal input in handler and restart.
6693 if No (First_Formal (Nam))
6694 and then Etype (Nam) = Standard_Void_Type
6695 and then not Error_Posted (N)
6696 and then Nkind (Parent (N)) /= N_Exception_Handler
6698 -- For the case of a procedure call. We give the message
6699 -- only if the call is the first statement in a sequence
6700 -- of statements, or if all previous statements are
6701 -- simple assignments. This is simply a heuristic to
6702 -- decrease false positives, without losing too many good
6703 -- warnings. The idea is that these previous statements
6704 -- may affect global variables the procedure depends on.
6705 -- We also exclude raise statements, that may arise from
6706 -- constraint checks and are probably unrelated to the
6707 -- intended control flow.
6709 if Nkind (N) = N_Procedure_Call_Statement
6710 and then Is_List_Member (N)
6716 while Present (P) loop
6717 if not Nkind_In (P, N_Assignment_Statement,
6718 N_Raise_Constraint_Error)
6728 -- Do not give warning if we are in a conditional context
6731 K : constant Node_Kind := Nkind (Parent (N));
6733 if (K = N_Loop_Statement
6734 and then Present (Iteration_Scheme (Parent (N))))
6735 or else K = N_If_Statement
6736 or else K = N_Elsif_Part
6737 or else K = N_Case_Statement_Alternative
6743 -- Here warning is to be issued
6745 Set_Has_Recursive_Call (Nam);
6746 Error_Msg_Warn := SPARK_Mode /= On;
6747 Error_Msg_N ("possible infinite recursion<<!", N);
6748 Error_Msg_N ("\Storage_Error ]<<!", N);
6754 Scop := Scope (Scop);
6755 end loop Scope_Loop;
6759 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6761 Check_Obsolescent_2005_Entity (Nam, Subp);
6763 -- If subprogram name is a predefined operator, it was given in
6764 -- functional notation. Replace call node with operator node, so
6765 -- that actuals can be resolved appropriately.
6767 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6768 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6771 elsif Present (Alias (Nam))
6772 and then Is_Predefined_Op (Alias (Nam))
6774 Resolve_Actuals (N, Nam);
6775 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6779 -- Create a transient scope if the resulting type requires it
6781 -- There are several notable exceptions:
6783 -- a) In init procs, the transient scope overhead is not needed, and is
6784 -- even incorrect when the call is a nested initialization call for a
6785 -- component whose expansion may generate adjust calls. However, if the
6786 -- call is some other procedure call within an initialization procedure
6787 -- (for example a call to Create_Task in the init_proc of the task
6788 -- run-time record) a transient scope must be created around this call.
6790 -- b) Enumeration literal pseudo-calls need no transient scope
6792 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6793 -- functions) do not use the secondary stack even though the return
6794 -- type may be unconstrained.
6796 -- d) Calls to a build-in-place function, since such functions may
6797 -- allocate their result directly in a target object, and cases where
6798 -- the result does get allocated in the secondary stack are checked for
6799 -- within the specialized Exp_Ch6 procedures for expanding those
6800 -- build-in-place calls.
6802 -- e) Calls to inlinable expression functions do not use the secondary
6803 -- stack (since the call will be replaced by its returned object).
6805 -- f) If the subprogram is marked Inline_Always, then even if it returns
6806 -- an unconstrained type the call does not require use of the secondary
6807 -- stack. However, inlining will only take place if the body to inline
6808 -- is already present. It may not be available if e.g. the subprogram is
6809 -- declared in a child instance.
6812 and then Has_Pragma_Inline (Nam)
6813 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6814 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6818 elsif Ekind (Nam) = E_Enumeration_Literal
6819 or else Is_Build_In_Place_Function (Nam)
6820 or else Is_Intrinsic_Subprogram (Nam)
6821 or else Is_Inlinable_Expression_Function (Nam)
6825 -- A return statement from an ignored Ghost function does not use the
6826 -- secondary stack (or any other one).
6828 elsif Expander_Active
6829 and then Ekind_In (Nam, E_Function, E_Subprogram_Type)
6830 and then Requires_Transient_Scope (Etype (Nam))
6831 and then not Is_Ignored_Ghost_Entity (Nam)
6833 Establish_Transient_Scope (N, Manage_Sec_Stack => True);
6835 -- If the call appears within the bounds of a loop, it will be
6836 -- rewritten and reanalyzed, nothing left to do here.
6838 if Nkind (N) /= N_Function_Call then
6843 -- A protected function cannot be called within the definition of the
6844 -- enclosing protected type, unless it is part of a pre/postcondition
6845 -- on another protected operation. This may appear in the entry wrapper
6846 -- created for an entry with preconditions.
6848 if Is_Protected_Type (Scope (Nam))
6849 and then In_Open_Scopes (Scope (Nam))
6850 and then not Has_Completion (Scope (Nam))
6851 and then not In_Spec_Expression
6852 and then not Is_Entry_Wrapper (Current_Scope)
6855 ("& cannot be called before end of protected definition", N, Nam);
6858 -- Propagate interpretation to actuals, and add default expressions
6861 if Present (First_Formal (Nam)) then
6862 Resolve_Actuals (N, Nam);
6864 -- Overloaded literals are rewritten as function calls, for purpose of
6865 -- resolution. After resolution, we can replace the call with the
6868 elsif Ekind (Nam) = E_Enumeration_Literal then
6869 Copy_Node (Subp, N);
6870 Resolve_Entity_Name (N, Typ);
6872 -- Avoid validation, since it is a static function call
6874 Generate_Reference (Nam, Subp);
6878 -- If the subprogram is not global, then kill all saved values and
6879 -- checks. This is a bit conservative, since in many cases we could do
6880 -- better, but it is not worth the effort. Similarly, we kill constant
6881 -- values. However we do not need to do this for internal entities
6882 -- (unless they are inherited user-defined subprograms), since they
6883 -- are not in the business of molesting local values.
6885 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6886 -- kill all checks and values for calls to global subprograms. This
6887 -- takes care of the case where an access to a local subprogram is
6888 -- taken, and could be passed directly or indirectly and then called
6889 -- from almost any context.
6891 -- Note: we do not do this step till after resolving the actuals. That
6892 -- way we still take advantage of the current value information while
6893 -- scanning the actuals.
6895 -- We suppress killing values if we are processing the nodes associated
6896 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6897 -- type kills all the values as part of analyzing the code that
6898 -- initializes the dispatch tables.
6900 if Inside_Freezing_Actions = 0
6901 and then (not Is_Library_Level_Entity (Nam)
6902 or else Suppress_Value_Tracking_On_Call
6903 (Nearest_Dynamic_Scope (Current_Scope)))
6904 and then (Comes_From_Source (Nam)
6905 or else (Present (Alias (Nam))
6906 and then Comes_From_Source (Alias (Nam))))
6908 Kill_Current_Values;
6911 -- If we are warning about unread OUT parameters, this is the place to
6912 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6913 -- after the above call to Kill_Current_Values (since that call clears
6914 -- the Last_Assignment field of all local variables).
6916 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6917 and then Comes_From_Source (N)
6918 and then In_Extended_Main_Source_Unit (N)
6925 F := First_Formal (Nam);
6926 A := First_Actual (N);
6927 while Present (F) and then Present (A) loop
6928 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6929 and then Warn_On_Modified_As_Out_Parameter (F)
6930 and then Is_Entity_Name (A)
6931 and then Present (Entity (A))
6932 and then Comes_From_Source (N)
6933 and then Safe_To_Capture_Value (N, Entity (A))
6935 Set_Last_Assignment (Entity (A), A);
6944 -- If the subprogram is a primitive operation, check whether or not
6945 -- it is a correct dispatching call.
6947 if Is_Overloadable (Nam)
6948 and then Is_Dispatching_Operation (Nam)
6950 Check_Dispatching_Call (N);
6952 elsif Ekind (Nam) /= E_Subprogram_Type
6953 and then Is_Abstract_Subprogram (Nam)
6954 and then not In_Instance
6956 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6959 -- If this is a dispatching call, generate the appropriate reference,
6960 -- for better source navigation in GNAT Studio.
6962 if Is_Overloadable (Nam)
6963 and then Present (Controlling_Argument (N))
6965 Generate_Reference (Nam, Subp, 'R');
6967 -- Normal case, not a dispatching call: generate a call reference
6970 Generate_Reference (Nam, Subp, 's');
6973 if Is_Intrinsic_Subprogram (Nam) then
6974 Check_Intrinsic_Call (N);
6977 -- Check for violation of restriction No_Specific_Termination_Handlers
6978 -- and warn on a potentially blocking call to Abort_Task.
6980 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6981 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6983 Is_RTE (Nam, RE_Specific_Handler))
6985 Check_Restriction (No_Specific_Termination_Handlers, N);
6987 elsif Is_RTE (Nam, RE_Abort_Task) then
6988 Check_Potentially_Blocking_Operation (N);
6991 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6992 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6993 -- need to check the second argument to determine whether it is an
6994 -- absolute or relative timing event.
6996 if Restriction_Check_Required (No_Relative_Delay)
6997 and then Is_RTE (Nam, RE_Set_Handler)
6998 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
7000 Check_Restriction (No_Relative_Delay, N);
7003 -- Issue an error for a call to an eliminated subprogram. This routine
7004 -- will not perform the check if the call appears within a default
7007 Check_For_Eliminated_Subprogram (Subp, Nam);
7009 -- In formal mode, the primitive operations of a tagged type or type
7010 -- extension do not include functions that return the tagged type.
7012 if Nkind (N) = N_Function_Call
7013 and then Is_Tagged_Type (Etype (N))
7014 and then Is_Entity_Name (Name (N))
7015 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
7017 Check_SPARK_05_Restriction ("function not inherited", N);
7020 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
7021 -- class-wide and the call dispatches on result in a context that does
7022 -- not provide a tag, the call raises Program_Error.
7024 if Nkind (N) = N_Function_Call
7025 and then In_Instance
7026 and then Is_Generic_Actual_Type (Typ)
7027 and then Is_Class_Wide_Type (Typ)
7028 and then Has_Controlling_Result (Nam)
7029 and then Nkind (Parent (N)) = N_Object_Declaration
7031 -- Verify that none of the formals are controlling
7034 Call_OK : Boolean := False;
7038 F := First_Formal (Nam);
7039 while Present (F) loop
7040 if Is_Controlling_Formal (F) then
7049 Error_Msg_Warn := SPARK_Mode /= On;
7050 Error_Msg_N ("!cannot determine tag of result<<", N);
7051 Error_Msg_N ("\Program_Error [<<!", N);
7053 Make_Raise_Program_Error (Sloc (N),
7054 Reason => PE_Explicit_Raise));
7059 -- Check for calling a function with OUT or IN OUT parameter when the
7060 -- calling context (us right now) is not Ada 2012, so does not allow
7061 -- OUT or IN OUT parameters in function calls. Functions declared in
7062 -- a predefined unit are OK, as they may be called indirectly from a
7063 -- user-declared instantiation.
7065 if Ada_Version < Ada_2012
7066 and then Ekind (Nam) = E_Function
7067 and then Has_Out_Or_In_Out_Parameter (Nam)
7068 and then not In_Predefined_Unit (Nam)
7070 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
7071 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
7074 -- Check the dimensions of the actuals in the call. For function calls,
7075 -- propagate the dimensions from the returned type to N.
7077 Analyze_Dimension_Call (N, Nam);
7079 -- All done, evaluate call and deal with elaboration issues
7083 if Legacy_Elaboration_Checks then
7084 Check_Elab_Call (N);
7087 -- Annotate the tree by creating a call marker in case the original call
7088 -- is transformed by expansion. The call marker is automatically saved
7089 -- for later examination by the ABE Processing phase.
7091 Build_Call_Marker (N);
7093 Mark_Use_Clauses (Subp);
7095 Warn_On_Overlapping_Actuals (Nam, N);
7097 -- In GNATprove mode, expansion is disabled, but we want to inline some
7098 -- subprograms to facilitate formal verification. Indirect calls through
7099 -- a subprogram type or within a generic cannot be inlined. Inlining is
7100 -- performed only for calls subject to SPARK_Mode on.
7103 and then SPARK_Mode = On
7104 and then Is_Overloadable (Nam)
7105 and then not Inside_A_Generic
7107 Nam_UA := Ultimate_Alias (Nam);
7108 Nam_Decl := Unit_Declaration_Node (Nam_UA);
7110 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
7111 Body_Id := Corresponding_Body (Nam_Decl);
7113 -- Nothing to do if the subprogram is not eligible for inlining in
7114 -- GNATprove mode, or inlining is disabled with switch -gnatdm
7116 if not Is_Inlined_Always (Nam_UA)
7117 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
7118 or else Debug_Flag_M
7122 -- Calls cannot be inlined inside assertions, as GNATprove treats
7123 -- assertions as logic expressions. Only issue a message when the
7124 -- body has been seen, otherwise this leads to spurious messages
7125 -- on expression functions.
7127 elsif In_Assertion_Expr /= 0 then
7128 if Present (Body_Id) then
7130 ("cannot inline & (in assertion expression)?", N, Nam_UA);
7133 -- Calls cannot be inlined inside default expressions
7135 elsif In_Default_Expr then
7137 ("cannot inline & (in default expression)?", N, Nam_UA);
7139 -- Calls cannot be inlined inside quantified expressions, which
7140 -- are left in expression form for GNATprove. Since these
7141 -- expressions are only preanalyzed, we need to detect the failure
7142 -- to inline outside of the case for Full_Analysis below.
7144 elsif In_Quantified_Expression (N) then
7146 ("cannot inline & (in quantified expression)?", N, Nam_UA);
7148 -- Inlining should not be performed during preanalysis
7150 elsif Full_Analysis then
7152 -- Do not inline calls inside expression functions or functions
7153 -- generated by the front end for subtype predicates, as this
7154 -- would prevent interpreting them as logical formulas in
7155 -- GNATprove. Only issue a message when the body has been seen,
7156 -- otherwise this leads to spurious messages on callees that
7157 -- are themselves expression functions.
7159 if Present (Current_Subprogram)
7161 (Is_Expression_Function_Or_Completion (Current_Subprogram)
7162 or else Is_Predicate_Function (Current_Subprogram)
7163 or else Is_Invariant_Procedure (Current_Subprogram)
7164 or else Is_DIC_Procedure (Current_Subprogram))
7166 if Present (Body_Id)
7167 and then Present (Body_To_Inline (Nam_Decl))
7169 if Is_Predicate_Function (Current_Subprogram) then
7171 ("cannot inline & (inside predicate)?",
7174 elsif Is_Invariant_Procedure (Current_Subprogram) then
7176 ("cannot inline & (inside invariant)?",
7179 elsif Is_DIC_Procedure (Current_Subprogram) then
7181 ("cannot inline & (inside Default_Initial_Condition)?",
7186 ("cannot inline & (inside expression function)?",
7191 -- Cannot inline a call inside the definition of a record type,
7192 -- typically inside the constraints of the type. Calls in
7193 -- default expressions are also not inlined, but this is
7194 -- filtered out above when testing In_Default_Expr.
7196 elsif Is_Record_Type (Current_Scope) then
7198 ("cannot inline & (inside record type)?", N, Nam_UA);
7200 -- With the one-pass inlining technique, a call cannot be
7201 -- inlined if the corresponding body has not been seen yet.
7203 elsif No (Body_Id) then
7205 ("cannot inline & (body not seen yet)?", N, Nam_UA);
7207 -- Nothing to do if there is no body to inline, indicating that
7208 -- the subprogram is not suitable for inlining in GNATprove
7211 elsif No (Body_To_Inline (Nam_Decl)) then
7214 -- Calls cannot be inlined inside potentially unevaluated
7215 -- expressions, as this would create complex actions inside
7216 -- expressions, that are not handled by GNATprove.
7218 elsif Is_Potentially_Unevaluated (N) then
7220 ("cannot inline & (in potentially unevaluated context)?",
7223 -- Calls cannot be inlined inside the conditions of while
7224 -- loops, as this would create complex actions inside
7225 -- the condition, that are not handled by GNATprove.
7227 elsif In_While_Loop_Condition (N) then
7229 ("cannot inline & (in while loop condition)?", N, Nam_UA);
7231 -- Do not inline calls which would possibly lead to missing a
7232 -- type conversion check on an input parameter.
7234 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode (N, Nam) then
7236 ("cannot inline & (possible check on input parameters)?",
7239 -- Otherwise, inline the call, issuing an info message when
7243 if Debug_Flag_Underscore_F then
7245 ("info: analyzing call to & in context?", N, Nam_UA);
7248 Expand_Inlined_Call (N, Nam_UA, Nam);
7255 -----------------------------
7256 -- Resolve_Case_Expression --
7257 -----------------------------
7259 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
7262 Alt_Typ : Entity_Id;
7266 Alt := First (Alternatives (N));
7267 while Present (Alt) loop
7268 Alt_Expr := Expression (Alt);
7270 if Error_Posted (Alt_Expr) then
7274 Resolve (Alt_Expr, Typ);
7275 Alt_Typ := Etype (Alt_Expr);
7277 -- When the expression is of a scalar subtype different from the
7278 -- result subtype, then insert a conversion to ensure the generation
7279 -- of a constraint check.
7281 if Is_Scalar_Type (Alt_Typ) and then Alt_Typ /= Typ then
7282 Rewrite (Alt_Expr, Convert_To (Typ, Alt_Expr));
7283 Analyze_And_Resolve (Alt_Expr, Typ);
7289 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
7290 -- dynamically tagged must be known statically.
7292 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
7293 Alt := First (Alternatives (N));
7294 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
7296 while Present (Alt) loop
7297 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
7299 ("all or none of the dependent expressions can be "
7300 & "dynamically tagged", N);
7308 Eval_Case_Expression (N);
7309 Analyze_Dimension (N);
7310 end Resolve_Case_Expression;
7312 -------------------------------
7313 -- Resolve_Character_Literal --
7314 -------------------------------
7316 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
7317 B_Typ : constant Entity_Id := Base_Type (Typ);
7321 -- Verify that the character does belong to the type of the context
7323 Set_Etype (N, B_Typ);
7324 Eval_Character_Literal (N);
7326 -- Wide_Wide_Character literals must always be defined, since the set
7327 -- of wide wide character literals is complete, i.e. if a character
7328 -- literal is accepted by the parser, then it is OK for wide wide
7329 -- character (out of range character literals are rejected).
7331 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
7334 -- Always accept character literal for type Any_Character, which
7335 -- occurs in error situations and in comparisons of literals, both
7336 -- of which should accept all literals.
7338 elsif B_Typ = Any_Character then
7341 -- For Standard.Character or a type derived from it, check that the
7342 -- literal is in range.
7344 elsif Root_Type (B_Typ) = Standard_Character then
7345 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
7349 -- For Standard.Wide_Character or a type derived from it, check that the
7350 -- literal is in range.
7352 elsif Root_Type (B_Typ) = Standard_Wide_Character then
7353 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
7357 -- If the entity is already set, this has already been resolved in a
7358 -- generic context, or comes from expansion. Nothing else to do.
7360 elsif Present (Entity (N)) then
7363 -- Otherwise we have a user defined character type, and we can use the
7364 -- standard visibility mechanisms to locate the referenced entity.
7367 C := Current_Entity (N);
7368 while Present (C) loop
7369 if Etype (C) = B_Typ then
7370 Set_Entity_With_Checks (N, C);
7371 Generate_Reference (C, N);
7379 -- If we fall through, then the literal does not match any of the
7380 -- entries of the enumeration type. This isn't just a constraint error
7381 -- situation, it is an illegality (see RM 4.2).
7384 ("character not defined for }", N, First_Subtype (B_Typ));
7385 end Resolve_Character_Literal;
7387 ---------------------------
7388 -- Resolve_Comparison_Op --
7389 ---------------------------
7391 -- Context requires a boolean type, and plays no role in resolution.
7392 -- Processing identical to that for equality operators. The result type is
7393 -- the base type, which matters when pathological subtypes of booleans with
7394 -- limited ranges are used.
7396 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
7397 L : constant Node_Id := Left_Opnd (N);
7398 R : constant Node_Id := Right_Opnd (N);
7402 -- If this is an intrinsic operation which is not predefined, use the
7403 -- types of its declared arguments to resolve the possibly overloaded
7404 -- operands. Otherwise the operands are unambiguous and specify the
7407 if Scope (Entity (N)) /= Standard_Standard then
7408 T := Etype (First_Entity (Entity (N)));
7411 T := Find_Unique_Type (L, R);
7413 if T = Any_Fixed then
7414 T := Unique_Fixed_Point_Type (L);
7418 Set_Etype (N, Base_Type (Typ));
7419 Generate_Reference (T, N, ' ');
7421 -- Skip remaining processing if already set to Any_Type
7423 if T = Any_Type then
7427 -- Deal with other error cases
7429 if T = Any_String or else
7430 T = Any_Composite or else
7433 if T = Any_Character then
7434 Ambiguous_Character (L);
7436 Error_Msg_N ("ambiguous operands for comparison", N);
7439 Set_Etype (N, Any_Type);
7443 -- Resolve the operands if types OK
7447 Check_Unset_Reference (L);
7448 Check_Unset_Reference (R);
7449 Generate_Operator_Reference (N, T);
7450 Check_Low_Bound_Tested (N);
7452 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
7453 -- types or array types except String.
7455 if Is_Boolean_Type (T) then
7456 Check_SPARK_05_Restriction
7457 ("comparison is not defined on Boolean type", N);
7459 elsif Is_Array_Type (T)
7460 and then Base_Type (T) /= Standard_String
7462 Check_SPARK_05_Restriction
7463 ("comparison is not defined on array types other than String", N);
7466 -- Check comparison on unordered enumeration
7468 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
7469 Error_Msg_Sloc := Sloc (Etype (L));
7471 ("comparison on unordered enumeration type& declared#?U?",
7475 Analyze_Dimension (N);
7477 -- Evaluate the relation (note we do this after the above check since
7478 -- this Eval call may change N to True/False. Skip this evaluation
7479 -- inside assertions, in order to keep assertions as written by users
7480 -- for tools that rely on these, e.g. GNATprove for loop invariants.
7481 -- Except evaluation is still performed even inside assertions for
7482 -- comparisons between values of universal type, which are useless
7483 -- for static analysis tools, and not supported even by GNATprove.
7485 if In_Assertion_Expr = 0
7486 or else (Is_Universal_Numeric_Type (Etype (L))
7488 Is_Universal_Numeric_Type (Etype (R)))
7490 Eval_Relational_Op (N);
7492 end Resolve_Comparison_Op;
7494 -----------------------------------------
7495 -- Resolve_Discrete_Subtype_Indication --
7496 -----------------------------------------
7498 procedure Resolve_Discrete_Subtype_Indication
7506 Analyze (Subtype_Mark (N));
7507 S := Entity (Subtype_Mark (N));
7509 if Nkind (Constraint (N)) /= N_Range_Constraint then
7510 Error_Msg_N ("expect range constraint for discrete type", N);
7511 Set_Etype (N, Any_Type);
7514 R := Range_Expression (Constraint (N));
7522 if Base_Type (S) /= Base_Type (Typ) then
7524 ("expect subtype of }", N, First_Subtype (Typ));
7526 -- Rewrite the constraint as a range of Typ
7527 -- to allow compilation to proceed further.
7530 Rewrite (Low_Bound (R),
7531 Make_Attribute_Reference (Sloc (Low_Bound (R)),
7532 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
7533 Attribute_Name => Name_First));
7534 Rewrite (High_Bound (R),
7535 Make_Attribute_Reference (Sloc (High_Bound (R)),
7536 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
7537 Attribute_Name => Name_First));
7541 Set_Etype (N, Etype (R));
7543 -- Additionally, we must check that the bounds are compatible
7544 -- with the given subtype, which might be different from the
7545 -- type of the context.
7547 Apply_Range_Check (R, S);
7549 -- ??? If the above check statically detects a Constraint_Error
7550 -- it replaces the offending bound(s) of the range R with a
7551 -- Constraint_Error node. When the itype which uses these bounds
7552 -- is frozen the resulting call to Duplicate_Subexpr generates
7553 -- a new temporary for the bounds.
7555 -- Unfortunately there are other itypes that are also made depend
7556 -- on these bounds, so when Duplicate_Subexpr is called they get
7557 -- a forward reference to the newly created temporaries and Gigi
7558 -- aborts on such forward references. This is probably sign of a
7559 -- more fundamental problem somewhere else in either the order of
7560 -- itype freezing or the way certain itypes are constructed.
7562 -- To get around this problem we call Remove_Side_Effects right
7563 -- away if either bounds of R are a Constraint_Error.
7566 L : constant Node_Id := Low_Bound (R);
7567 H : constant Node_Id := High_Bound (R);
7570 if Nkind (L) = N_Raise_Constraint_Error then
7571 Remove_Side_Effects (L);
7574 if Nkind (H) = N_Raise_Constraint_Error then
7575 Remove_Side_Effects (H);
7579 Check_Unset_Reference (Low_Bound (R));
7580 Check_Unset_Reference (High_Bound (R));
7583 end Resolve_Discrete_Subtype_Indication;
7585 -------------------------
7586 -- Resolve_Entity_Name --
7587 -------------------------
7589 -- Used to resolve identifiers and expanded names
7591 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
7592 function Is_Assignment_Or_Object_Expression
7594 Expr : Node_Id) return Boolean;
7595 -- Determine whether node Context denotes an assignment statement or an
7596 -- object declaration whose expression is node Expr.
7598 ----------------------------------------
7599 -- Is_Assignment_Or_Object_Expression --
7600 ----------------------------------------
7602 function Is_Assignment_Or_Object_Expression
7604 Expr : Node_Id) return Boolean
7607 if Nkind_In (Context, N_Assignment_Statement,
7608 N_Object_Declaration)
7609 and then Expression (Context) = Expr
7613 -- Check whether a construct that yields a name is the expression of
7614 -- an assignment statement or an object declaration.
7616 elsif (Nkind_In (Context, N_Attribute_Reference,
7617 N_Explicit_Dereference,
7618 N_Indexed_Component,
7619 N_Selected_Component,
7621 and then Prefix (Context) = Expr)
7623 (Nkind_In (Context, N_Type_Conversion,
7624 N_Unchecked_Type_Conversion)
7625 and then Expression (Context) = Expr)
7628 Is_Assignment_Or_Object_Expression
7629 (Context => Parent (Context),
7632 -- Otherwise the context is not an assignment statement or an object
7638 end Is_Assignment_Or_Object_Expression;
7642 E : constant Entity_Id := Entity (N);
7645 -- Start of processing for Resolve_Entity_Name
7648 -- If garbage from errors, set to Any_Type and return
7650 if No (E) and then Total_Errors_Detected /= 0 then
7651 Set_Etype (N, Any_Type);
7655 -- Replace named numbers by corresponding literals. Note that this is
7656 -- the one case where Resolve_Entity_Name must reset the Etype, since
7657 -- it is currently marked as universal.
7659 if Ekind (E) = E_Named_Integer then
7661 Eval_Named_Integer (N);
7663 elsif Ekind (E) = E_Named_Real then
7665 Eval_Named_Real (N);
7667 -- For enumeration literals, we need to make sure that a proper style
7668 -- check is done, since such literals are overloaded, and thus we did
7669 -- not do a style check during the first phase of analysis.
7671 elsif Ekind (E) = E_Enumeration_Literal then
7672 Set_Entity_With_Checks (N, E);
7673 Eval_Entity_Name (N);
7675 -- Case of (sub)type name appearing in a context where an expression
7676 -- is expected. This is legal if occurrence is a current instance.
7677 -- See RM 8.6 (17/3).
7679 elsif Is_Type (E) then
7680 if Is_Current_Instance (N) then
7683 -- Any other use is an error
7687 ("invalid use of subtype mark in expression or call", N);
7690 -- Check discriminant use if entity is discriminant in current scope,
7691 -- i.e. discriminant of record or concurrent type currently being
7692 -- analyzed. Uses in corresponding body are unrestricted.
7694 elsif Ekind (E) = E_Discriminant
7695 and then Scope (E) = Current_Scope
7696 and then not Has_Completion (Current_Scope)
7698 Check_Discriminant_Use (N);
7700 -- A parameterless generic function cannot appear in a context that
7701 -- requires resolution.
7703 elsif Ekind (E) = E_Generic_Function then
7704 Error_Msg_N ("illegal use of generic function", N);
7706 -- In Ada 83 an OUT parameter cannot be read, but attributes of
7707 -- array types (i.e. bounds and length) are legal.
7709 elsif Ekind (E) = E_Out_Parameter
7710 and then (Nkind (Parent (N)) /= N_Attribute_Reference
7711 or else Is_Scalar_Type (Etype (E)))
7713 and then (Nkind (Parent (N)) in N_Op
7714 or else Nkind (Parent (N)) = N_Explicit_Dereference
7715 or else Is_Assignment_Or_Object_Expression
7716 (Context => Parent (N),
7719 if Ada_Version = Ada_83 then
7720 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7723 -- In all other cases, just do the possible static evaluation
7726 -- A deferred constant that appears in an expression must have a
7727 -- completion, unless it has been removed by in-place expansion of
7728 -- an aggregate. A constant that is a renaming does not need
7731 if Ekind (E) = E_Constant
7732 and then Comes_From_Source (E)
7733 and then No (Constant_Value (E))
7734 and then Is_Frozen (Etype (E))
7735 and then not In_Spec_Expression
7736 and then not Is_Imported (E)
7737 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7739 if No_Initialization (Parent (E))
7740 or else (Present (Full_View (E))
7741 and then No_Initialization (Parent (Full_View (E))))
7746 ("deferred constant is frozen before completion", N);
7750 Eval_Entity_Name (N);
7755 -- When the entity appears in a parameter association, retrieve the
7756 -- related subprogram call.
7758 if Nkind (Par) = N_Parameter_Association then
7759 Par := Parent (Par);
7762 if Comes_From_Source (N) then
7764 -- The following checks are only relevant when SPARK_Mode is on as
7765 -- they are not standard Ada legality rules.
7767 if SPARK_Mode = On then
7769 -- An effectively volatile object subject to enabled properties
7770 -- Async_Writers or Effective_Reads must appear in non-interfering
7771 -- context (SPARK RM 7.1.3(12)).
7774 and then Is_Effectively_Volatile (E)
7775 and then (Async_Writers_Enabled (E)
7776 or else Effective_Reads_Enabled (E))
7777 and then not Is_OK_Volatile_Context (Par, N)
7780 ("volatile object cannot appear in this context "
7781 & "(SPARK RM 7.1.3(12))", N);
7784 -- Check for possible elaboration issues with respect to reads of
7785 -- variables. The act of renaming the variable is not considered a
7786 -- read as it simply establishes an alias.
7788 if Legacy_Elaboration_Checks
7789 and then Ekind (E) = E_Variable
7790 and then Dynamic_Elaboration_Checks
7791 and then Nkind (Par) /= N_Object_Renaming_Declaration
7793 Check_Elab_Call (N);
7797 -- The variable may eventually become a constituent of a single
7798 -- protected/task type. Record the reference now and verify its
7799 -- legality when analyzing the contract of the variable
7802 if Ekind (E) = E_Variable then
7803 Record_Possible_Part_Of_Reference (E, N);
7806 -- A Ghost entity must appear in a specific context
7808 if Is_Ghost_Entity (E) then
7809 Check_Ghost_Context (E, N);
7813 -- We may be resolving an entity within expanded code, so a reference to
7814 -- an entity should be ignored when calculating effective use clauses to
7815 -- avoid inappropriate marking.
7817 if Comes_From_Source (N) then
7818 Mark_Use_Clauses (E);
7820 end Resolve_Entity_Name;
7826 procedure Resolve_Entry (Entry_Name : Node_Id) is
7827 Loc : constant Source_Ptr := Sloc (Entry_Name);
7835 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7836 -- If the bounds of the entry family being called depend on task
7837 -- discriminants, build a new index subtype where a discriminant is
7838 -- replaced with the value of the discriminant of the target task.
7839 -- The target task is the prefix of the entry name in the call.
7841 -----------------------
7842 -- Actual_Index_Type --
7843 -----------------------
7845 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7846 Typ : constant Entity_Id := Entry_Index_Type (E);
7847 Tsk : constant Entity_Id := Scope (E);
7848 Lo : constant Node_Id := Type_Low_Bound (Typ);
7849 Hi : constant Node_Id := Type_High_Bound (Typ);
7852 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7853 -- If the bound is given by a discriminant, replace with a reference
7854 -- to the discriminant of the same name in the target task. If the
7855 -- entry name is the target of a requeue statement and the entry is
7856 -- in the current protected object, the bound to be used is the
7857 -- discriminal of the object (see Apply_Range_Checks for details of
7858 -- the transformation).
7860 -----------------------------
7861 -- Actual_Discriminant_Ref --
7862 -----------------------------
7864 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7865 Typ : constant Entity_Id := Etype (Bound);
7869 Remove_Side_Effects (Bound);
7871 if not Is_Entity_Name (Bound)
7872 or else Ekind (Entity (Bound)) /= E_Discriminant
7876 elsif Is_Protected_Type (Tsk)
7877 and then In_Open_Scopes (Tsk)
7878 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7880 -- Note: here Bound denotes a discriminant of the corresponding
7881 -- record type tskV, whose discriminal is a formal of the
7882 -- init-proc tskVIP. What we want is the body discriminal,
7883 -- which is associated to the discriminant of the original
7884 -- concurrent type tsk.
7886 return New_Occurrence_Of
7887 (Find_Body_Discriminal (Entity (Bound)), Loc);
7891 Make_Selected_Component (Loc,
7892 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7893 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7898 end Actual_Discriminant_Ref;
7900 -- Start of processing for Actual_Index_Type
7903 if not Has_Discriminants (Tsk)
7904 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7906 return Entry_Index_Type (E);
7909 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7910 Set_Etype (New_T, Base_Type (Typ));
7911 Set_Size_Info (New_T, Typ);
7912 Set_RM_Size (New_T, RM_Size (Typ));
7913 Set_Scalar_Range (New_T,
7914 Make_Range (Sloc (Entry_Name),
7915 Low_Bound => Actual_Discriminant_Ref (Lo),
7916 High_Bound => Actual_Discriminant_Ref (Hi)));
7920 end Actual_Index_Type;
7922 -- Start of processing for Resolve_Entry
7925 -- Find name of entry being called, and resolve prefix of name with its
7926 -- own type. The prefix can be overloaded, and the name and signature of
7927 -- the entry must be taken into account.
7929 if Nkind (Entry_Name) = N_Indexed_Component then
7931 -- Case of dealing with entry family within the current tasks
7933 E_Name := Prefix (Entry_Name);
7936 E_Name := Entry_Name;
7939 if Is_Entity_Name (E_Name) then
7941 -- Entry call to an entry (or entry family) in the current task. This
7942 -- is legal even though the task will deadlock. Rewrite as call to
7945 -- This can also be a call to an entry in an enclosing task. If this
7946 -- is a single task, we have to retrieve its name, because the scope
7947 -- of the entry is the task type, not the object. If the enclosing
7948 -- task is a task type, the identity of the task is given by its own
7951 -- Finally this can be a requeue on an entry of the same task or
7952 -- protected object.
7954 S := Scope (Entity (E_Name));
7956 for J in reverse 0 .. Scope_Stack.Last loop
7957 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7958 and then not Comes_From_Source (S)
7960 -- S is an enclosing task or protected object. The concurrent
7961 -- declaration has been converted into a type declaration, and
7962 -- the object itself has an object declaration that follows
7963 -- the type in the same declarative part.
7965 Tsk := Next_Entity (S);
7966 while Etype (Tsk) /= S loop
7973 elsif S = Scope_Stack.Table (J).Entity then
7975 -- Call to current task. Will be transformed into call to Self
7983 Make_Selected_Component (Loc,
7984 Prefix => New_Occurrence_Of (S, Loc),
7986 New_Occurrence_Of (Entity (E_Name), Loc));
7987 Rewrite (E_Name, New_N);
7990 elsif Nkind (Entry_Name) = N_Selected_Component
7991 and then Is_Overloaded (Prefix (Entry_Name))
7993 -- Use the entry name (which must be unique at this point) to find
7994 -- the prefix that returns the corresponding task/protected type.
7997 Pref : constant Node_Id := Prefix (Entry_Name);
7998 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
8003 Get_First_Interp (Pref, I, It);
8004 while Present (It.Typ) loop
8005 if Scope (Ent) = It.Typ then
8006 Set_Etype (Pref, It.Typ);
8010 Get_Next_Interp (I, It);
8015 if Nkind (Entry_Name) = N_Selected_Component then
8016 Resolve (Prefix (Entry_Name));
8018 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
8019 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
8020 Resolve (Prefix (Prefix (Entry_Name)));
8021 Index := First (Expressions (Entry_Name));
8022 Resolve (Index, Entry_Index_Type (Nam));
8024 -- Generate a reference for the index when it denotes an entity
8026 if Is_Entity_Name (Index) then
8027 Generate_Reference (Entity (Index), Nam);
8030 -- Up to this point the expression could have been the actual in a
8031 -- simple entry call, and be given by a named association.
8033 if Nkind (Index) = N_Parameter_Association then
8034 Error_Msg_N ("expect expression for entry index", Index);
8036 Apply_Range_Check (Index, Actual_Index_Type (Nam));
8041 ------------------------
8042 -- Resolve_Entry_Call --
8043 ------------------------
8045 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
8046 Entry_Name : constant Node_Id := Name (N);
8047 Loc : constant Source_Ptr := Sloc (Entry_Name);
8055 -- We kill all checks here, because it does not seem worth the effort to
8056 -- do anything better, an entry call is a big operation.
8060 -- Processing of the name is similar for entry calls and protected
8061 -- operation calls. Once the entity is determined, we can complete
8062 -- the resolution of the actuals.
8064 -- The selector may be overloaded, in the case of a protected object
8065 -- with overloaded functions. The type of the context is used for
8068 if Nkind (Entry_Name) = N_Selected_Component
8069 and then Is_Overloaded (Selector_Name (Entry_Name))
8070 and then Typ /= Standard_Void_Type
8077 Get_First_Interp (Selector_Name (Entry_Name), I, It);
8078 while Present (It.Typ) loop
8079 if Covers (Typ, It.Typ) then
8080 Set_Entity (Selector_Name (Entry_Name), It.Nam);
8081 Set_Etype (Entry_Name, It.Typ);
8083 Generate_Reference (It.Typ, N, ' ');
8086 Get_Next_Interp (I, It);
8091 Resolve_Entry (Entry_Name);
8093 if Nkind (Entry_Name) = N_Selected_Component then
8095 -- Simple entry or protected operation call
8097 Nam := Entity (Selector_Name (Entry_Name));
8098 Obj := Prefix (Entry_Name);
8100 if Is_Subprogram (Nam) then
8101 Check_For_Eliminated_Subprogram (Entry_Name, Nam);
8104 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
8106 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
8108 -- Call to member of entry family
8110 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
8111 Obj := Prefix (Prefix (Entry_Name));
8112 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
8115 -- We cannot in general check the maximum depth of protected entry calls
8116 -- at compile time. But we can tell that any protected entry call at all
8117 -- violates a specified nesting depth of zero.
8119 if Is_Protected_Type (Scope (Nam)) then
8120 Check_Restriction (Max_Entry_Queue_Length, N);
8123 -- Use context type to disambiguate a protected function that can be
8124 -- called without actuals and that returns an array type, and where the
8125 -- argument list may be an indexing of the returned value.
8127 if Ekind (Nam) = E_Function
8128 and then Needs_No_Actuals (Nam)
8129 and then Present (Parameter_Associations (N))
8131 ((Is_Array_Type (Etype (Nam))
8132 and then Covers (Typ, Component_Type (Etype (Nam))))
8134 or else (Is_Access_Type (Etype (Nam))
8135 and then Is_Array_Type (Designated_Type (Etype (Nam)))
8139 Component_Type (Designated_Type (Etype (Nam))))))
8142 Index_Node : Node_Id;
8146 Make_Indexed_Component (Loc,
8148 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
8149 Expressions => Parameter_Associations (N));
8151 -- Since we are correcting a node classification error made by the
8152 -- parser, we call Replace rather than Rewrite.
8154 Replace (N, Index_Node);
8155 Set_Etype (Prefix (N), Etype (Nam));
8157 Resolve_Indexed_Component (N, Typ);
8162 if Ekind_In (Nam, E_Entry, E_Entry_Family)
8163 and then Present (Contract_Wrapper (Nam))
8164 and then Current_Scope /= Contract_Wrapper (Nam)
8166 -- Note the entity being called before rewriting the call, so that
8167 -- it appears used at this point.
8169 Generate_Reference (Nam, Entry_Name, 'r');
8171 -- Rewrite as call to the precondition wrapper, adding the task
8172 -- object to the list of actuals. If the call is to a member of an
8173 -- entry family, include the index as well.
8177 New_Actuals : List_Id;
8180 New_Actuals := New_List (Obj);
8182 if Nkind (Entry_Name) = N_Indexed_Component then
8183 Append_To (New_Actuals,
8184 New_Copy_Tree (First (Expressions (Entry_Name))));
8187 Append_List (Parameter_Associations (N), New_Actuals);
8189 Make_Procedure_Call_Statement (Loc,
8191 New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
8192 Parameter_Associations => New_Actuals);
8193 Rewrite (N, New_Call);
8195 -- Preanalyze and resolve new call. Current procedure is called
8196 -- from Resolve_Call, after which expansion will take place.
8198 Preanalyze_And_Resolve (N);
8203 -- The operation name may have been overloaded. Order the actuals
8204 -- according to the formals of the resolved entity, and set the return
8205 -- type to that of the operation.
8208 Normalize_Actuals (N, Nam, False, Norm_OK);
8209 pragma Assert (Norm_OK);
8210 Set_Etype (N, Etype (Nam));
8212 -- Reset the Is_Overloaded flag, since resolution is now completed
8214 -- Simple entry call
8216 if Nkind (Entry_Name) = N_Selected_Component then
8217 Set_Is_Overloaded (Selector_Name (Entry_Name), False);
8219 -- Call to a member of an entry family
8221 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
8222 Set_Is_Overloaded (Selector_Name (Prefix (Entry_Name)), False);
8226 Resolve_Actuals (N, Nam);
8227 Check_Internal_Protected_Use (N, Nam);
8229 -- Create a call reference to the entry
8231 Generate_Reference (Nam, Entry_Name, 's');
8233 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
8234 Check_Potentially_Blocking_Operation (N);
8237 -- Verify that a procedure call cannot masquerade as an entry
8238 -- call where an entry call is expected.
8240 if Ekind (Nam) = E_Procedure then
8241 if Nkind (Parent (N)) = N_Entry_Call_Alternative
8242 and then N = Entry_Call_Statement (Parent (N))
8244 Error_Msg_N ("entry call required in select statement", N);
8246 elsif Nkind (Parent (N)) = N_Triggering_Alternative
8247 and then N = Triggering_Statement (Parent (N))
8249 Error_Msg_N ("triggering statement cannot be procedure call", N);
8251 elsif Ekind (Scope (Nam)) = E_Task_Type
8252 and then not In_Open_Scopes (Scope (Nam))
8254 Error_Msg_N ("task has no entry with this name", Entry_Name);
8258 -- After resolution, entry calls and protected procedure calls are
8259 -- changed into entry calls, for expansion. The structure of the node
8260 -- does not change, so it can safely be done in place. Protected
8261 -- function calls must keep their structure because they are
8264 if Ekind (Nam) /= E_Function then
8266 -- A protected operation that is not a function may modify the
8267 -- corresponding object, and cannot apply to a constant. If this
8268 -- is an internal call, the prefix is the type itself.
8270 if Is_Protected_Type (Scope (Nam))
8271 and then not Is_Variable (Obj)
8272 and then (not Is_Entity_Name (Obj)
8273 or else not Is_Type (Entity (Obj)))
8276 ("prefix of protected procedure or entry call must be variable",
8281 Entry_Call : Node_Id;
8285 Make_Entry_Call_Statement (Loc,
8287 Parameter_Associations => Parameter_Associations (N));
8289 -- Inherit relevant attributes from the original call
8291 Set_First_Named_Actual
8292 (Entry_Call, First_Named_Actual (N));
8294 Set_Is_Elaboration_Checks_OK_Node
8295 (Entry_Call, Is_Elaboration_Checks_OK_Node (N));
8297 Set_Is_Elaboration_Warnings_OK_Node
8298 (Entry_Call, Is_Elaboration_Warnings_OK_Node (N));
8300 Set_Is_SPARK_Mode_On_Node
8301 (Entry_Call, Is_SPARK_Mode_On_Node (N));
8303 Rewrite (N, Entry_Call);
8304 Set_Analyzed (N, True);
8307 -- Protected functions can return on the secondary stack, in which case
8308 -- we must trigger the transient scope mechanism.
8310 elsif Expander_Active
8311 and then Requires_Transient_Scope (Etype (Nam))
8313 Establish_Transient_Scope (N, Manage_Sec_Stack => True);
8315 end Resolve_Entry_Call;
8317 -------------------------
8318 -- Resolve_Equality_Op --
8319 -------------------------
8321 -- Both arguments must have the same type, and the boolean context does
8322 -- not participate in the resolution. The first pass verifies that the
8323 -- interpretation is not ambiguous, and the type of the left argument is
8324 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
8325 -- are strings or aggregates, allocators, or Null, they are ambiguous even
8326 -- though they carry a single (universal) type. Diagnose this case here.
8328 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
8329 L : constant Node_Id := Left_Opnd (N);
8330 R : constant Node_Id := Right_Opnd (N);
8331 T : Entity_Id := Find_Unique_Type (L, R);
8333 procedure Check_If_Expression (Cond : Node_Id);
8334 -- The resolution rule for if expressions requires that each such must
8335 -- have a unique type. This means that if several dependent expressions
8336 -- are of a non-null anonymous access type, and the context does not
8337 -- impose an expected type (as can be the case in an equality operation)
8338 -- the expression must be rejected.
8340 procedure Explain_Redundancy (N : Node_Id);
8341 -- Attempt to explain the nature of a redundant comparison with True. If
8342 -- the expression N is too complex, this routine issues a general error
8345 function Find_Unique_Access_Type return Entity_Id;
8346 -- In the case of allocators and access attributes, the context must
8347 -- provide an indication of the specific access type to be used. If
8348 -- one operand is of such a "generic" access type, check whether there
8349 -- is a specific visible access type that has the same designated type.
8350 -- This is semantically dubious, and of no interest to any real code,
8351 -- but c48008a makes it all worthwhile.
8353 -------------------------
8354 -- Check_If_Expression --
8355 -------------------------
8357 procedure Check_If_Expression (Cond : Node_Id) is
8358 Then_Expr : Node_Id;
8359 Else_Expr : Node_Id;
8362 if Nkind (Cond) = N_If_Expression then
8363 Then_Expr := Next (First (Expressions (Cond)));
8364 Else_Expr := Next (Then_Expr);
8366 if Nkind (Then_Expr) /= N_Null
8367 and then Nkind (Else_Expr) /= N_Null
8369 Error_Msg_N ("cannot determine type of if expression", Cond);
8372 end Check_If_Expression;
8374 ------------------------
8375 -- Explain_Redundancy --
8376 ------------------------
8378 procedure Explain_Redundancy (N : Node_Id) is
8386 -- Strip the operand down to an entity
8389 if Nkind (Val) = N_Selected_Component then
8390 Val := Selector_Name (Val);
8396 -- The construct denotes an entity
8398 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
8399 Val_Id := Entity (Val);
8401 -- Do not generate an error message when the comparison is done
8402 -- against the enumeration literal Standard.True.
8404 if Ekind (Val_Id) /= E_Enumeration_Literal then
8406 -- Build a customized error message
8409 Add_Str_To_Name_Buffer ("?r?");
8411 if Ekind (Val_Id) = E_Component then
8412 Add_Str_To_Name_Buffer ("component ");
8414 elsif Ekind (Val_Id) = E_Constant then
8415 Add_Str_To_Name_Buffer ("constant ");
8417 elsif Ekind (Val_Id) = E_Discriminant then
8418 Add_Str_To_Name_Buffer ("discriminant ");
8420 elsif Is_Formal (Val_Id) then
8421 Add_Str_To_Name_Buffer ("parameter ");
8423 elsif Ekind (Val_Id) = E_Variable then
8424 Add_Str_To_Name_Buffer ("variable ");
8427 Add_Str_To_Name_Buffer ("& is always True!");
8430 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
8433 -- The construct is too complex to disect, issue a general message
8436 Error_Msg_N ("?r?expression is always True!", Val);
8438 end Explain_Redundancy;
8440 -----------------------------
8441 -- Find_Unique_Access_Type --
8442 -----------------------------
8444 function Find_Unique_Access_Type return Entity_Id is
8450 if Ekind_In (Etype (R), E_Allocator_Type,
8451 E_Access_Attribute_Type)
8453 Acc := Designated_Type (Etype (R));
8455 elsif Ekind_In (Etype (L), E_Allocator_Type,
8456 E_Access_Attribute_Type)
8458 Acc := Designated_Type (Etype (L));
8464 while S /= Standard_Standard loop
8465 E := First_Entity (S);
8466 while Present (E) loop
8468 and then Is_Access_Type (E)
8469 and then Ekind (E) /= E_Allocator_Type
8470 and then Designated_Type (E) = Base_Type (Acc)
8482 end Find_Unique_Access_Type;
8484 -- Start of processing for Resolve_Equality_Op
8487 Set_Etype (N, Base_Type (Typ));
8488 Generate_Reference (T, N, ' ');
8490 if T = Any_Fixed then
8491 T := Unique_Fixed_Point_Type (L);
8494 if T /= Any_Type then
8495 if T = Any_String or else
8496 T = Any_Composite or else
8499 if T = Any_Character then
8500 Ambiguous_Character (L);
8502 Error_Msg_N ("ambiguous operands for equality", N);
8505 Set_Etype (N, Any_Type);
8508 elsif T = Any_Access
8509 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
8511 T := Find_Unique_Access_Type;
8514 Error_Msg_N ("ambiguous operands for equality", N);
8515 Set_Etype (N, Any_Type);
8519 -- If expressions must have a single type, and if the context does
8520 -- not impose one the dependent expressions cannot be anonymous
8523 -- Why no similar processing for case expressions???
8525 elsif Ada_Version >= Ada_2012
8526 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
8527 E_Anonymous_Access_Subprogram_Type)
8528 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
8529 E_Anonymous_Access_Subprogram_Type)
8531 Check_If_Expression (L);
8532 Check_If_Expression (R);
8538 -- In SPARK, equality operators = and /= for array types other than
8539 -- String are only defined when, for each index position, the
8540 -- operands have equal static bounds.
8542 if Is_Array_Type (T) then
8544 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8545 -- operation if not needed.
8547 if Restriction_Check_Required (SPARK_05)
8548 and then Base_Type (T) /= Standard_String
8549 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
8550 and then Etype (L) /= Any_Composite -- or else L in error
8551 and then Etype (R) /= Any_Composite -- or else R in error
8552 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
8554 Check_SPARK_05_Restriction
8555 ("array types should have matching static bounds", N);
8559 -- If the unique type is a class-wide type then it will be expanded
8560 -- into a dispatching call to the predefined primitive. Therefore we
8561 -- check here for potential violation of such restriction.
8563 if Is_Class_Wide_Type (T) then
8564 Check_Restriction (No_Dispatching_Calls, N);
8567 -- Only warn for redundant equality comparison to True for objects
8568 -- (e.g. "X = True") and operations (e.g. "(X < Y) = True"). For
8569 -- other expressions, it may be a matter of preference to write
8570 -- "Expr = True" or "Expr".
8572 if Warn_On_Redundant_Constructs
8573 and then Comes_From_Source (N)
8574 and then Comes_From_Source (R)
8575 and then Is_Entity_Name (R)
8576 and then Entity (R) = Standard_True
8578 ((Is_Entity_Name (L) and then Is_Object (Entity (L)))
8582 Error_Msg_N -- CODEFIX
8583 ("?r?comparison with True is redundant!", N);
8584 Explain_Redundancy (Original_Node (R));
8587 -- If the equality is overloaded and the operands have resolved
8588 -- properly, set the proper equality operator on the node. The
8589 -- current setting is the first one found during analysis, which
8590 -- is not necessarily the one to which the node has resolved.
8592 if Is_Overloaded (N) then
8598 Get_First_Interp (N, I, It);
8600 -- If the equality is user-defined, the type of the operands
8601 -- matches that of the formals. For a predefined operator,
8602 -- it is the scope that matters, given that the predefined
8603 -- equality has Any_Type formals. In either case the result
8604 -- type (most often Boolean) must match the context. The scope
8605 -- is either that of the type, if there is a generated equality
8606 -- (when there is an equality for the component type), or else
8607 -- Standard otherwise.
8609 while Present (It.Typ) loop
8610 if Etype (It.Nam) = Typ
8612 (Etype (First_Entity (It.Nam)) = Etype (L)
8613 or else Scope (It.Nam) = Standard_Standard
8614 or else Scope (It.Nam) = Scope (T))
8616 Set_Entity (N, It.Nam);
8618 Set_Is_Overloaded (N, False);
8622 Get_Next_Interp (I, It);
8625 -- If expansion is active and this is an inherited operation,
8626 -- replace it with its ancestor. This must not be done during
8627 -- preanalysis because the type may not be frozen yet, as when
8628 -- the context is a precondition or postcondition.
8630 if Present (Alias (Entity (N))) and then Expander_Active then
8631 Set_Entity (N, Alias (Entity (N)));
8636 Check_Unset_Reference (L);
8637 Check_Unset_Reference (R);
8638 Generate_Operator_Reference (N, T);
8639 Check_Low_Bound_Tested (N);
8641 -- If this is an inequality, it may be the implicit inequality
8642 -- created for a user-defined operation, in which case the corres-
8643 -- ponding equality operation is not intrinsic, and the operation
8644 -- cannot be constant-folded. Else fold.
8646 if Nkind (N) = N_Op_Eq
8647 or else Comes_From_Source (Entity (N))
8648 or else Ekind (Entity (N)) = E_Operator
8649 or else Is_Intrinsic_Subprogram
8650 (Corresponding_Equality (Entity (N)))
8652 Analyze_Dimension (N);
8653 Eval_Relational_Op (N);
8655 elsif Nkind (N) = N_Op_Ne
8656 and then Is_Abstract_Subprogram (Entity (N))
8658 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
8661 -- Ada 2005: If one operand is an anonymous access type, convert the
8662 -- other operand to it, to ensure that the underlying types match in
8663 -- the back-end. Same for access_to_subprogram, and the conversion
8664 -- verifies that the types are subtype conformant.
8666 -- We apply the same conversion in the case one of the operands is a
8667 -- private subtype of the type of the other.
8669 -- Why the Expander_Active test here ???
8673 (Ekind_In (T, E_Anonymous_Access_Type,
8674 E_Anonymous_Access_Subprogram_Type)
8675 or else Is_Private_Type (T))
8677 if Etype (L) /= T then
8679 Make_Unchecked_Type_Conversion (Sloc (L),
8680 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
8681 Expression => Relocate_Node (L)));
8682 Analyze_And_Resolve (L, T);
8685 if (Etype (R)) /= T then
8687 Make_Unchecked_Type_Conversion (Sloc (R),
8688 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
8689 Expression => Relocate_Node (R)));
8690 Analyze_And_Resolve (R, T);
8694 end Resolve_Equality_Op;
8696 ----------------------------------
8697 -- Resolve_Explicit_Dereference --
8698 ----------------------------------
8700 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
8701 Loc : constant Source_Ptr := Sloc (N);
8703 P : constant Node_Id := Prefix (N);
8706 -- The candidate prefix type, if overloaded
8712 Check_Fully_Declared_Prefix (Typ, P);
8715 -- A useful optimization: check whether the dereference denotes an
8716 -- element of a container, and if so rewrite it as a call to the
8717 -- corresponding Element function.
8719 -- Disabled for now, on advice of ARG. A more restricted form of the
8720 -- predicate might be acceptable ???
8722 -- if Is_Container_Element (N) then
8726 if Is_Overloaded (P) then
8728 -- Use the context type to select the prefix that has the correct
8729 -- designated type. Keep the first match, which will be the inner-
8732 Get_First_Interp (P, I, It);
8734 while Present (It.Typ) loop
8735 if Is_Access_Type (It.Typ)
8736 and then Covers (Typ, Designated_Type (It.Typ))
8742 -- Remove access types that do not match, but preserve access
8743 -- to subprogram interpretations, in case a further dereference
8744 -- is needed (see below).
8746 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8750 Get_Next_Interp (I, It);
8753 if Present (P_Typ) then
8755 Set_Etype (N, Designated_Type (P_Typ));
8758 -- If no interpretation covers the designated type of the prefix,
8759 -- this is the pathological case where not all implementations of
8760 -- the prefix allow the interpretation of the node as a call. Now
8761 -- that the expected type is known, Remove other interpretations
8762 -- from prefix, rewrite it as a call, and resolve again, so that
8763 -- the proper call node is generated.
8765 Get_First_Interp (P, I, It);
8766 while Present (It.Typ) loop
8767 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8771 Get_Next_Interp (I, It);
8775 Make_Function_Call (Loc,
8777 Make_Explicit_Dereference (Loc,
8779 Parameter_Associations => New_List);
8781 Save_Interps (N, New_N);
8783 Analyze_And_Resolve (N, Typ);
8787 -- If not overloaded, resolve P with its own type
8793 -- If the prefix might be null, add an access check
8795 if Is_Access_Type (Etype (P))
8796 and then not Can_Never_Be_Null (Etype (P))
8798 Apply_Access_Check (N);
8801 -- If the designated type is a packed unconstrained array type, and the
8802 -- explicit dereference is not in the context of an attribute reference,
8803 -- then we must compute and set the actual subtype, since it is needed
8804 -- by Gigi. The reason we exclude the attribute case is that this is
8805 -- handled fine by Gigi, and in fact we use such attributes to build the
8806 -- actual subtype. We also exclude generated code (which builds actual
8807 -- subtypes directly if they are needed).
8809 if Is_Array_Type (Etype (N))
8810 and then Is_Packed (Etype (N))
8811 and then not Is_Constrained (Etype (N))
8812 and then Nkind (Parent (N)) /= N_Attribute_Reference
8813 and then Comes_From_Source (N)
8815 Set_Etype (N, Get_Actual_Subtype (N));
8818 Analyze_Dimension (N);
8820 -- Note: No Eval processing is required for an explicit dereference,
8821 -- because such a name can never be static.
8823 end Resolve_Explicit_Dereference;
8825 -------------------------------------
8826 -- Resolve_Expression_With_Actions --
8827 -------------------------------------
8829 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8833 -- If N has no actions, and its expression has been constant folded,
8834 -- then rewrite N as just its expression. Note, we can't do this in
8835 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8836 -- Expression (N) to be expanded again.
8838 if Is_Empty_List (Actions (N))
8839 and then Compile_Time_Known_Value (Expression (N))
8841 Rewrite (N, Expression (N));
8843 end Resolve_Expression_With_Actions;
8845 ----------------------------------
8846 -- Resolve_Generalized_Indexing --
8847 ----------------------------------
8849 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8850 Indexing : constant Node_Id := Generalized_Indexing (N);
8856 -- In ASIS mode, propagate the information about the indexes back to
8857 -- to the original indexing node. The generalized indexing is either
8858 -- a function call, or a dereference of one. The actuals include the
8859 -- prefix of the original node, which is the container expression.
8862 Resolve (Indexing, Typ);
8863 Set_Etype (N, Etype (Indexing));
8864 Set_Is_Overloaded (N, False);
8867 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8869 Call := Prefix (Call);
8872 if Nkind (Call) = N_Function_Call then
8873 Indexes := New_Copy_List (Parameter_Associations (Call));
8874 Pref := Remove_Head (Indexes);
8875 Set_Expressions (N, Indexes);
8877 -- If expression is to be reanalyzed, reset Generalized_Indexing
8878 -- to recreate call node, as is the case when the expression is
8879 -- part of an expression function.
8881 if In_Spec_Expression then
8882 Set_Generalized_Indexing (N, Empty);
8885 Set_Prefix (N, Pref);
8889 Rewrite (N, Indexing);
8892 end Resolve_Generalized_Indexing;
8894 ---------------------------
8895 -- Resolve_If_Expression --
8896 ---------------------------
8898 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8899 procedure Apply_Check (Expr : Node_Id);
8900 -- When a dependent expression is of a subtype different from
8901 -- the context subtype, then insert a qualification to ensure
8902 -- the generation of a constraint check. This was previously
8903 -- for scalar types. For array types apply a length check, given
8904 -- that the context in general allows sliding, while a qualified
8905 -- expression forces equality of bounds.
8911 procedure Apply_Check (Expr : Node_Id) is
8912 Expr_Typ : constant Entity_Id := Etype (Expr);
8913 Loc : constant Source_Ptr := Sloc (Expr);
8917 or else Is_Tagged_Type (Typ)
8918 or else Is_Access_Type (Typ)
8919 or else not Is_Constrained (Typ)
8920 or else Inside_A_Generic
8924 elsif Is_Array_Type (Typ) then
8925 Apply_Length_Check (Expr, Typ);
8929 Make_Qualified_Expression (Loc,
8930 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
8931 Expression => Relocate_Node (Expr)));
8933 Analyze_And_Resolve (Expr, Typ);
8939 Condition : constant Node_Id := First (Expressions (N));
8940 Else_Expr : Node_Id;
8941 Then_Expr : Node_Id;
8943 -- Start of processing for Resolve_If_Expression
8946 -- Defend against malformed expressions
8948 if No (Condition) then
8952 Then_Expr := Next (Condition);
8954 if No (Then_Expr) then
8958 Else_Expr := Next (Then_Expr);
8960 Resolve (Condition, Any_Boolean);
8961 Resolve (Then_Expr, Typ);
8962 Apply_Check (Then_Expr);
8964 -- If ELSE expression present, just resolve using the determined type
8965 -- If type is universal, resolve to any member of the class.
8967 if Present (Else_Expr) then
8968 if Typ = Universal_Integer then
8969 Resolve (Else_Expr, Any_Integer);
8971 elsif Typ = Universal_Real then
8972 Resolve (Else_Expr, Any_Real);
8975 Resolve (Else_Expr, Typ);
8978 Apply_Check (Else_Expr);
8980 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8981 -- dynamically tagged must be known statically.
8983 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8984 if Is_Dynamically_Tagged (Then_Expr) /=
8985 Is_Dynamically_Tagged (Else_Expr)
8987 Error_Msg_N ("all or none of the dependent expressions "
8988 & "can be dynamically tagged", N);
8992 -- If no ELSE expression is present, root type must be Standard.Boolean
8993 -- and we provide a Standard.True result converted to the appropriate
8994 -- Boolean type (in case it is a derived boolean type).
8996 elsif Root_Type (Typ) = Standard_Boolean then
8998 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8999 Analyze_And_Resolve (Else_Expr, Typ);
9000 Append_To (Expressions (N), Else_Expr);
9003 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
9004 Append_To (Expressions (N), Error);
9009 if not Error_Posted (N) then
9010 Eval_If_Expression (N);
9013 Analyze_Dimension (N);
9014 end Resolve_If_Expression;
9016 -------------------------------
9017 -- Resolve_Indexed_Component --
9018 -------------------------------
9020 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
9021 Name : constant Node_Id := Prefix (N);
9023 Array_Type : Entity_Id := Empty; -- to prevent junk warning
9027 if Present (Generalized_Indexing (N)) then
9028 Resolve_Generalized_Indexing (N, Typ);
9032 if Is_Overloaded (Name) then
9034 -- Use the context type to select the prefix that yields the correct
9040 I1 : Interp_Index := 0;
9041 P : constant Node_Id := Prefix (N);
9042 Found : Boolean := False;
9045 Get_First_Interp (P, I, It);
9046 while Present (It.Typ) loop
9047 if (Is_Array_Type (It.Typ)
9048 and then Covers (Typ, Component_Type (It.Typ)))
9049 or else (Is_Access_Type (It.Typ)
9050 and then Is_Array_Type (Designated_Type (It.Typ))
9054 Component_Type (Designated_Type (It.Typ))))
9057 It := Disambiguate (P, I1, I, Any_Type);
9059 if It = No_Interp then
9060 Error_Msg_N ("ambiguous prefix for indexing", N);
9066 Array_Type := It.Typ;
9072 Array_Type := It.Typ;
9077 Get_Next_Interp (I, It);
9082 Array_Type := Etype (Name);
9085 Resolve (Name, Array_Type);
9086 Array_Type := Get_Actual_Subtype_If_Available (Name);
9088 -- If prefix is access type, dereference to get real array type.
9089 -- Note: we do not apply an access check because the expander always
9090 -- introduces an explicit dereference, and the check will happen there.
9092 if Is_Access_Type (Array_Type) then
9093 Array_Type := Designated_Type (Array_Type);
9096 -- If name was overloaded, set component type correctly now
9097 -- If a misplaced call to an entry family (which has no index types)
9098 -- return. Error will be diagnosed from calling context.
9100 if Is_Array_Type (Array_Type) then
9101 Set_Etype (N, Component_Type (Array_Type));
9106 Index := First_Index (Array_Type);
9107 Expr := First (Expressions (N));
9109 -- The prefix may have resolved to a string literal, in which case its
9110 -- etype has a special representation. This is only possible currently
9111 -- if the prefix is a static concatenation, written in functional
9114 if Ekind (Array_Type) = E_String_Literal_Subtype then
9115 Resolve (Expr, Standard_Positive);
9118 while Present (Index) and Present (Expr) loop
9119 Resolve (Expr, Etype (Index));
9120 Check_Unset_Reference (Expr);
9122 if Is_Scalar_Type (Etype (Expr)) then
9123 Apply_Scalar_Range_Check (Expr, Etype (Index));
9125 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
9133 Analyze_Dimension (N);
9135 -- Do not generate the warning on suspicious index if we are analyzing
9136 -- package Ada.Tags; otherwise we will report the warning with the
9137 -- Prims_Ptr field of the dispatch table.
9139 if Scope (Etype (Prefix (N))) = Standard_Standard
9141 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
9144 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
9145 Eval_Indexed_Component (N);
9148 -- If the array type is atomic, and the component is not atomic, then
9149 -- this is worth a warning, since we have a situation where the access
9150 -- to the component may cause extra read/writes of the atomic array
9151 -- object, or partial word accesses, which could be unexpected.
9153 if Nkind (N) = N_Indexed_Component
9154 and then Is_Atomic_Ref_With_Address (N)
9155 and then not (Has_Atomic_Components (Array_Type)
9156 or else (Is_Entity_Name (Prefix (N))
9157 and then Has_Atomic_Components
9158 (Entity (Prefix (N)))))
9159 and then not Is_Atomic (Component_Type (Array_Type))
9162 ("??access to non-atomic component of atomic array", Prefix (N));
9164 ("??\may cause unexpected accesses to atomic object", Prefix (N));
9166 end Resolve_Indexed_Component;
9168 -----------------------------
9169 -- Resolve_Integer_Literal --
9170 -----------------------------
9172 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
9175 Eval_Integer_Literal (N);
9176 end Resolve_Integer_Literal;
9178 --------------------------------
9179 -- Resolve_Intrinsic_Operator --
9180 --------------------------------
9182 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
9183 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
9188 function Convert_Operand (Opnd : Node_Id) return Node_Id;
9189 -- If the operand is a literal, it cannot be the expression in a
9190 -- conversion. Use a qualified expression instead.
9192 ---------------------
9193 -- Convert_Operand --
9194 ---------------------
9196 function Convert_Operand (Opnd : Node_Id) return Node_Id is
9197 Loc : constant Source_Ptr := Sloc (Opnd);
9201 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
9203 Make_Qualified_Expression (Loc,
9204 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
9205 Expression => Relocate_Node (Opnd));
9209 Res := Unchecked_Convert_To (Btyp, Opnd);
9213 end Convert_Operand;
9215 -- Start of processing for Resolve_Intrinsic_Operator
9218 -- We must preserve the original entity in a generic setting, so that
9219 -- the legality of the operation can be verified in an instance.
9221 if not Expander_Active then
9226 while Scope (Op) /= Standard_Standard loop
9228 pragma Assert (Present (Op));
9232 Set_Is_Overloaded (N, False);
9234 -- If the result or operand types are private, rewrite with unchecked
9235 -- conversions on the operands and the result, to expose the proper
9236 -- underlying numeric type.
9238 if Is_Private_Type (Typ)
9239 or else Is_Private_Type (Etype (Left_Opnd (N)))
9240 or else Is_Private_Type (Etype (Right_Opnd (N)))
9242 Arg1 := Convert_Operand (Left_Opnd (N));
9244 if Nkind (N) = N_Op_Expon then
9245 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
9247 Arg2 := Convert_Operand (Right_Opnd (N));
9250 if Nkind (Arg1) = N_Type_Conversion then
9251 Save_Interps (Left_Opnd (N), Expression (Arg1));
9254 if Nkind (Arg2) = N_Type_Conversion then
9255 Save_Interps (Right_Opnd (N), Expression (Arg2));
9258 Set_Left_Opnd (N, Arg1);
9259 Set_Right_Opnd (N, Arg2);
9261 Set_Etype (N, Btyp);
9262 Rewrite (N, Unchecked_Convert_To (Typ, N));
9265 elsif Typ /= Etype (Left_Opnd (N))
9266 or else Typ /= Etype (Right_Opnd (N))
9268 -- Add explicit conversion where needed, and save interpretations in
9269 -- case operands are overloaded.
9271 Arg1 := Convert_To (Typ, Left_Opnd (N));
9272 Arg2 := Convert_To (Typ, Right_Opnd (N));
9274 if Nkind (Arg1) = N_Type_Conversion then
9275 Save_Interps (Left_Opnd (N), Expression (Arg1));
9277 Save_Interps (Left_Opnd (N), Arg1);
9280 if Nkind (Arg2) = N_Type_Conversion then
9281 Save_Interps (Right_Opnd (N), Expression (Arg2));
9283 Save_Interps (Right_Opnd (N), Arg2);
9286 Rewrite (Left_Opnd (N), Arg1);
9287 Rewrite (Right_Opnd (N), Arg2);
9290 Resolve_Arithmetic_Op (N, Typ);
9293 Resolve_Arithmetic_Op (N, Typ);
9295 end Resolve_Intrinsic_Operator;
9297 --------------------------------------
9298 -- Resolve_Intrinsic_Unary_Operator --
9299 --------------------------------------
9301 procedure Resolve_Intrinsic_Unary_Operator
9305 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
9311 while Scope (Op) /= Standard_Standard loop
9313 pragma Assert (Present (Op));
9318 if Is_Private_Type (Typ) then
9319 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
9320 Save_Interps (Right_Opnd (N), Expression (Arg2));
9322 Set_Right_Opnd (N, Arg2);
9324 Set_Etype (N, Btyp);
9325 Rewrite (N, Unchecked_Convert_To (Typ, N));
9329 Resolve_Unary_Op (N, Typ);
9331 end Resolve_Intrinsic_Unary_Operator;
9333 ------------------------
9334 -- Resolve_Logical_Op --
9335 ------------------------
9337 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
9341 Check_No_Direct_Boolean_Operators (N);
9343 -- Predefined operations on scalar types yield the base type. On the
9344 -- other hand, logical operations on arrays yield the type of the
9345 -- arguments (and the context).
9347 if Is_Array_Type (Typ) then
9350 B_Typ := Base_Type (Typ);
9353 -- The following test is required because the operands of the operation
9354 -- may be literals, in which case the resulting type appears to be
9355 -- compatible with a signed integer type, when in fact it is compatible
9356 -- only with modular types. If the context itself is universal, the
9357 -- operation is illegal.
9359 if not Valid_Boolean_Arg (Typ) then
9360 Error_Msg_N ("invalid context for logical operation", N);
9361 Set_Etype (N, Any_Type);
9364 elsif Typ = Any_Modular then
9366 ("no modular type available in this context", N);
9367 Set_Etype (N, Any_Type);
9370 elsif Is_Modular_Integer_Type (Typ)
9371 and then Etype (Left_Opnd (N)) = Universal_Integer
9372 and then Etype (Right_Opnd (N)) = Universal_Integer
9374 Check_For_Visible_Operator (N, B_Typ);
9377 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
9378 -- is active and the result type is standard Boolean (do not mess with
9379 -- ops that return a nonstandard Boolean type, because something strange
9382 -- Note: you might expect this replacement to be done during expansion,
9383 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
9384 -- is used, no part of the right operand of an "and" or "or" operator
9385 -- should be executed if the left operand would short-circuit the
9386 -- evaluation of the corresponding "and then" or "or else". If we left
9387 -- the replacement to expansion time, then run-time checks associated
9388 -- with such operands would be evaluated unconditionally, due to being
9389 -- before the condition prior to the rewriting as short-circuit forms
9390 -- during expansion.
9392 if Short_Circuit_And_Or
9393 and then B_Typ = Standard_Boolean
9394 and then Nkind_In (N, N_Op_And, N_Op_Or)
9396 -- Mark the corresponding putative SCO operator as truly a logical
9397 -- (and short-circuit) operator.
9399 if Generate_SCO and then Comes_From_Source (N) then
9400 Set_SCO_Logical_Operator (N);
9403 if Nkind (N) = N_Op_And then
9405 Make_And_Then (Sloc (N),
9406 Left_Opnd => Relocate_Node (Left_Opnd (N)),
9407 Right_Opnd => Relocate_Node (Right_Opnd (N))));
9408 Analyze_And_Resolve (N, B_Typ);
9410 -- Case of OR changed to OR ELSE
9414 Make_Or_Else (Sloc (N),
9415 Left_Opnd => Relocate_Node (Left_Opnd (N)),
9416 Right_Opnd => Relocate_Node (Right_Opnd (N))));
9417 Analyze_And_Resolve (N, B_Typ);
9420 -- Return now, since analysis of the rewritten ops will take care of
9421 -- other reference bookkeeping and expression folding.
9426 Resolve (Left_Opnd (N), B_Typ);
9427 Resolve (Right_Opnd (N), B_Typ);
9429 Check_Unset_Reference (Left_Opnd (N));
9430 Check_Unset_Reference (Right_Opnd (N));
9432 Set_Etype (N, B_Typ);
9433 Generate_Operator_Reference (N, B_Typ);
9434 Eval_Logical_Op (N);
9436 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
9437 -- only when both operands have same static lower and higher bounds. Of
9438 -- course the types have to match, so only check if operands are
9439 -- compatible and the node itself has no errors.
9441 if Is_Array_Type (B_Typ)
9442 and then Nkind (N) in N_Binary_Op
9445 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
9446 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
9449 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9450 -- operation if not needed.
9452 if Restriction_Check_Required (SPARK_05)
9453 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
9454 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
9455 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
9456 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
9458 Check_SPARK_05_Restriction
9459 ("array types should have matching static bounds", N);
9463 end Resolve_Logical_Op;
9465 ---------------------------
9466 -- Resolve_Membership_Op --
9467 ---------------------------
9469 -- The context can only be a boolean type, and does not determine the
9470 -- arguments. Arguments should be unambiguous, but the preference rule for
9471 -- universal types applies.
9473 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
9474 pragma Warnings (Off, Typ);
9476 L : constant Node_Id := Left_Opnd (N);
9477 R : constant Node_Id := Right_Opnd (N);
9480 procedure Resolve_Set_Membership;
9481 -- Analysis has determined a unique type for the left operand. Use it to
9482 -- resolve the disjuncts.
9484 ----------------------------
9485 -- Resolve_Set_Membership --
9486 ----------------------------
9488 procedure Resolve_Set_Membership is
9493 -- If the left operand is overloaded, find type compatible with not
9494 -- overloaded alternative of the right operand.
9496 if Is_Overloaded (L) then
9498 Alt := First (Alternatives (N));
9499 while Present (Alt) loop
9500 if not Is_Overloaded (Alt) then
9501 Ltyp := Intersect_Types (L, Alt);
9508 -- Unclear how to resolve expression if all alternatives are also
9512 Error_Msg_N ("ambiguous expression", N);
9521 Alt := First (Alternatives (N));
9522 while Present (Alt) loop
9524 -- Alternative is an expression, a range
9525 -- or a subtype mark.
9527 if not Is_Entity_Name (Alt)
9528 or else not Is_Type (Entity (Alt))
9530 Resolve (Alt, Ltyp);
9536 -- Check for duplicates for discrete case
9538 if Is_Discrete_Type (Ltyp) then
9545 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
9549 -- Loop checking duplicates. This is quadratic, but giant sets
9550 -- are unlikely in this context so it's a reasonable choice.
9553 Alt := First (Alternatives (N));
9554 while Present (Alt) loop
9555 if Is_OK_Static_Expression (Alt)
9556 and then (Nkind_In (Alt, N_Integer_Literal,
9557 N_Character_Literal)
9558 or else Nkind (Alt) in N_Has_Entity)
9561 Alts (Nalts) := (Alt, Expr_Value (Alt));
9563 for J in 1 .. Nalts - 1 loop
9564 if Alts (J).Val = Alts (Nalts).Val then
9565 Error_Msg_Sloc := Sloc (Alts (J).Alt);
9566 Error_Msg_N ("duplicate of value given#??", Alt);
9576 -- RM 4.5.2 (28.1/3) specifies that for types other than records or
9577 -- limited types, evaluation of a membership test uses the predefined
9578 -- equality for the type. This may be confusing to users, and the
9579 -- following warning appears useful for the most common case.
9581 if Is_Scalar_Type (Ltyp)
9582 and then Present (Get_User_Defined_Eq (Ltyp))
9585 ("membership test on& uses predefined equality?", N, Ltyp);
9587 ("\even if user-defined equality exists (RM 4.5.2 (28.1/3)?", N);
9589 end Resolve_Set_Membership;
9591 -- Start of processing for Resolve_Membership_Op
9594 if L = Error or else R = Error then
9598 if Present (Alternatives (N)) then
9599 Resolve_Set_Membership;
9602 elsif not Is_Overloaded (R)
9604 (Etype (R) = Universal_Integer
9606 Etype (R) = Universal_Real)
9607 and then Is_Overloaded (L)
9611 -- Ada 2005 (AI-251): Support the following case:
9613 -- type I is interface;
9614 -- type T is tagged ...
9616 -- function Test (O : I'Class) is
9618 -- return O in T'Class.
9621 -- In this case we have nothing else to do. The membership test will be
9622 -- done at run time.
9624 elsif Ada_Version >= Ada_2005
9625 and then Is_Class_Wide_Type (Etype (L))
9626 and then Is_Interface (Etype (L))
9627 and then not Is_Interface (Etype (R))
9631 T := Intersect_Types (L, R);
9634 -- If mixed-mode operations are present and operands are all literal,
9635 -- the only interpretation involves Duration, which is probably not
9636 -- the intention of the programmer.
9638 if T = Any_Fixed then
9639 T := Unique_Fixed_Point_Type (N);
9641 if T = Any_Type then
9647 Check_Unset_Reference (L);
9649 if Nkind (R) = N_Range
9650 and then not Is_Scalar_Type (T)
9652 Error_Msg_N ("scalar type required for range", R);
9655 if Is_Entity_Name (R) then
9656 Freeze_Expression (R);
9659 Check_Unset_Reference (R);
9662 -- Here after resolving membership operation
9666 Eval_Membership_Op (N);
9667 end Resolve_Membership_Op;
9673 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
9674 Loc : constant Source_Ptr := Sloc (N);
9677 -- Handle restriction against anonymous null access values This
9678 -- restriction can be turned off using -gnatdj.
9680 -- Ada 2005 (AI-231): Remove restriction
9682 if Ada_Version < Ada_2005
9683 and then not Debug_Flag_J
9684 and then Ekind (Typ) = E_Anonymous_Access_Type
9685 and then Comes_From_Source (N)
9687 -- In the common case of a call which uses an explicitly null value
9688 -- for an access parameter, give specialized error message.
9690 if Nkind (Parent (N)) in N_Subprogram_Call then
9692 ("null is not allowed as argument for an access parameter", N);
9694 -- Standard message for all other cases (are there any?)
9698 ("null cannot be of an anonymous access type", N);
9702 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
9703 -- assignment to a null-excluding object.
9705 if Ada_Version >= Ada_2005
9706 and then Can_Never_Be_Null (Typ)
9707 and then Nkind (Parent (N)) = N_Assignment_Statement
9709 if Inside_Init_Proc then
9711 -- Decide whether to generate an if_statement around our
9712 -- null-excluding check to avoid them on certain internal object
9713 -- declarations by looking at the type the current Init_Proc
9717 -- if T1b_skip_null_excluding_check then
9718 -- [constraint_error "access check failed"]
9721 if Needs_Conditional_Null_Excluding_Check
9722 (Etype (First_Formal (Enclosing_Init_Proc)))
9725 Make_If_Statement (Loc,
9727 Make_Identifier (Loc,
9729 (Chars (Typ), "_skip_null_excluding_check")),
9732 Make_Raise_Constraint_Error (Loc,
9733 Reason => CE_Access_Check_Failed))));
9735 -- Otherwise, simply create the check
9739 Make_Raise_Constraint_Error (Loc,
9740 Reason => CE_Access_Check_Failed));
9744 (Compile_Time_Constraint_Error (N,
9745 "(Ada 2005) null not allowed in null-excluding objects??"),
9746 Make_Raise_Constraint_Error (Loc,
9747 Reason => CE_Access_Check_Failed));
9751 -- In a distributed context, null for a remote access to subprogram may
9752 -- need to be replaced with a special record aggregate. In this case,
9753 -- return after having done the transformation.
9755 if (Ekind (Typ) = E_Record_Type
9756 or else Is_Remote_Access_To_Subprogram_Type (Typ))
9757 and then Remote_AST_Null_Value (N, Typ)
9762 -- The null literal takes its type from the context
9767 -----------------------
9768 -- Resolve_Op_Concat --
9769 -----------------------
9771 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
9773 -- We wish to avoid deep recursion, because concatenations are often
9774 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
9775 -- operands nonrecursively until we find something that is not a simple
9776 -- concatenation (A in this case). We resolve that, and then walk back
9777 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9778 -- to do the rest of the work at each level. The Parent pointers allow
9779 -- us to avoid recursion, and thus avoid running out of memory. See also
9780 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9786 -- The following code is equivalent to:
9788 -- Resolve_Op_Concat_First (NN, Typ);
9789 -- Resolve_Op_Concat_Arg (N, ...);
9790 -- Resolve_Op_Concat_Rest (N, Typ);
9792 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9793 -- operand is a concatenation.
9795 -- Walk down left operands
9798 Resolve_Op_Concat_First (NN, Typ);
9799 Op1 := Left_Opnd (NN);
9800 exit when not (Nkind (Op1) = N_Op_Concat
9801 and then not Is_Array_Type (Component_Type (Typ))
9802 and then Entity (Op1) = Entity (NN));
9806 -- Now (given the above example) NN is A&B and Op1 is A
9808 -- First resolve Op1 ...
9810 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
9812 -- ... then walk NN back up until we reach N (where we started), calling
9813 -- Resolve_Op_Concat_Rest along the way.
9816 Resolve_Op_Concat_Rest (NN, Typ);
9821 if Base_Type (Etype (N)) /= Standard_String then
9822 Check_SPARK_05_Restriction
9823 ("result of concatenation should have type String", N);
9825 end Resolve_Op_Concat;
9827 ---------------------------
9828 -- Resolve_Op_Concat_Arg --
9829 ---------------------------
9831 procedure Resolve_Op_Concat_Arg
9837 Btyp : constant Entity_Id := Base_Type (Typ);
9838 Ctyp : constant Entity_Id := Component_Type (Typ);
9843 or else (not Is_Overloaded (Arg)
9844 and then Etype (Arg) /= Any_Composite
9845 and then Covers (Ctyp, Etype (Arg)))
9847 Resolve (Arg, Ctyp);
9849 Resolve (Arg, Btyp);
9852 -- If both Array & Array and Array & Component are visible, there is a
9853 -- potential ambiguity that must be reported.
9855 elsif Has_Compatible_Type (Arg, Ctyp) then
9856 if Nkind (Arg) = N_Aggregate
9857 and then Is_Composite_Type (Ctyp)
9859 if Is_Private_Type (Ctyp) then
9860 Resolve (Arg, Btyp);
9862 -- If the operation is user-defined and not overloaded use its
9863 -- profile. The operation may be a renaming, in which case it has
9864 -- been rewritten, and we want the original profile.
9866 elsif not Is_Overloaded (N)
9867 and then Comes_From_Source (Entity (Original_Node (N)))
9868 and then Ekind (Entity (Original_Node (N))) = E_Function
9872 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9875 -- Otherwise an aggregate may match both the array type and the
9879 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9880 Set_Etype (Arg, Any_Type);
9884 if Is_Overloaded (Arg)
9885 and then Has_Compatible_Type (Arg, Typ)
9886 and then Etype (Arg) /= Any_Type
9894 Get_First_Interp (Arg, I, It);
9896 Get_Next_Interp (I, It);
9898 -- Special-case the error message when the overloading is
9899 -- caused by a function that yields an array and can be
9900 -- called without parameters.
9902 if It.Nam = Func then
9903 Error_Msg_Sloc := Sloc (Func);
9904 Error_Msg_N ("ambiguous call to function#", Arg);
9906 ("\\interpretation as call yields&", Arg, Typ);
9908 ("\\interpretation as indexing of call yields&",
9909 Arg, Component_Type (Typ));
9912 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9914 Get_First_Interp (Arg, I, It);
9915 while Present (It.Nam) loop
9916 Error_Msg_Sloc := Sloc (It.Nam);
9918 if Base_Type (It.Typ) = Btyp
9920 Base_Type (It.Typ) = Base_Type (Ctyp)
9922 Error_Msg_N -- CODEFIX
9923 ("\\possible interpretation#", Arg);
9926 Get_Next_Interp (I, It);
9932 Resolve (Arg, Component_Type (Typ));
9934 if Nkind (Arg) = N_String_Literal then
9935 Set_Etype (Arg, Component_Type (Typ));
9938 if Arg = Left_Opnd (N) then
9939 Set_Is_Component_Left_Opnd (N);
9941 Set_Is_Component_Right_Opnd (N);
9946 Resolve (Arg, Btyp);
9949 -- Concatenation is restricted in SPARK: each operand must be either a
9950 -- string literal, the name of a string constant, a static character or
9951 -- string expression, or another concatenation. Arg cannot be a
9952 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9953 -- separately on each final operand, past concatenation operations.
9955 if Is_Character_Type (Etype (Arg)) then
9956 if not Is_OK_Static_Expression (Arg) then
9957 Check_SPARK_05_Restriction
9958 ("character operand for concatenation should be static", Arg);
9961 elsif Is_String_Type (Etype (Arg)) then
9962 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9963 and then Is_Constant_Object (Entity (Arg)))
9964 and then not Is_OK_Static_Expression (Arg)
9966 Check_SPARK_05_Restriction
9967 ("string operand for concatenation should be static", Arg);
9970 -- Do not issue error on an operand that is neither a character nor a
9971 -- string, as the error is issued in Resolve_Op_Concat.
9977 Check_Unset_Reference (Arg);
9978 end Resolve_Op_Concat_Arg;
9980 -----------------------------
9981 -- Resolve_Op_Concat_First --
9982 -----------------------------
9984 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9985 Btyp : constant Entity_Id := Base_Type (Typ);
9986 Op1 : constant Node_Id := Left_Opnd (N);
9987 Op2 : constant Node_Id := Right_Opnd (N);
9990 -- The parser folds an enormous sequence of concatenations of string
9991 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9992 -- in the right operand. If the expression resolves to a predefined "&"
9993 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9994 -- we give an error. See P_Simple_Expression in Par.Ch4.
9996 if Nkind (Op2) = N_String_Literal
9997 and then Is_Folded_In_Parser (Op2)
9998 and then Ekind (Entity (N)) = E_Function
10000 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
10001 and then String_Length (Strval (Op1)) = 0);
10002 Error_Msg_N ("too many user-defined concatenations", N);
10006 Set_Etype (N, Btyp);
10008 if Is_Limited_Composite (Btyp) then
10009 Error_Msg_N ("concatenation not available for limited array", N);
10010 Explain_Limited_Type (Btyp, N);
10012 end Resolve_Op_Concat_First;
10014 ----------------------------
10015 -- Resolve_Op_Concat_Rest --
10016 ----------------------------
10018 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
10019 Op1 : constant Node_Id := Left_Opnd (N);
10020 Op2 : constant Node_Id := Right_Opnd (N);
10023 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
10025 Generate_Operator_Reference (N, Typ);
10027 if Is_String_Type (Typ) then
10028 Eval_Concatenation (N);
10031 -- If this is not a static concatenation, but the result is a string
10032 -- type (and not an array of strings) ensure that static string operands
10033 -- have their subtypes properly constructed.
10035 if Nkind (N) /= N_String_Literal
10036 and then Is_Character_Type (Component_Type (Typ))
10038 Set_String_Literal_Subtype (Op1, Typ);
10039 Set_String_Literal_Subtype (Op2, Typ);
10041 end Resolve_Op_Concat_Rest;
10043 ----------------------
10044 -- Resolve_Op_Expon --
10045 ----------------------
10047 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
10048 B_Typ : constant Entity_Id := Base_Type (Typ);
10051 -- Catch attempts to do fixed-point exponentiation with universal
10052 -- operands, which is a case where the illegality is not caught during
10053 -- normal operator analysis. This is not done in preanalysis mode
10054 -- since the tree is not fully decorated during preanalysis.
10056 if Full_Analysis then
10057 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
10058 Error_Msg_N ("exponentiation not available for fixed point", N);
10061 elsif Nkind (Parent (N)) in N_Op
10062 and then Present (Etype (Parent (N)))
10063 and then Is_Fixed_Point_Type (Etype (Parent (N)))
10064 and then Etype (N) = Universal_Real
10065 and then Comes_From_Source (N)
10067 Error_Msg_N ("exponentiation not available for fixed point", N);
10072 if Comes_From_Source (N)
10073 and then Ekind (Entity (N)) = E_Function
10074 and then Is_Imported (Entity (N))
10075 and then Is_Intrinsic_Subprogram (Entity (N))
10077 Resolve_Intrinsic_Operator (N, Typ);
10081 if Etype (Left_Opnd (N)) = Universal_Integer
10082 or else Etype (Left_Opnd (N)) = Universal_Real
10084 Check_For_Visible_Operator (N, B_Typ);
10087 -- We do the resolution using the base type, because intermediate values
10088 -- in expressions are always of the base type, not a subtype of it.
10090 Resolve (Left_Opnd (N), B_Typ);
10091 Resolve (Right_Opnd (N), Standard_Integer);
10093 -- For integer types, right argument must be in Natural range
10095 if Is_Integer_Type (Typ) then
10096 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
10099 Check_Unset_Reference (Left_Opnd (N));
10100 Check_Unset_Reference (Right_Opnd (N));
10102 Set_Etype (N, B_Typ);
10103 Generate_Operator_Reference (N, B_Typ);
10105 Analyze_Dimension (N);
10107 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
10108 -- Evaluate the exponentiation operator for dimensioned type
10110 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
10115 -- Set overflow checking bit. Much cleverer code needed here eventually
10116 -- and perhaps the Resolve routines should be separated for the various
10117 -- arithmetic operations, since they will need different processing. ???
10119 if Nkind (N) in N_Op then
10120 if not Overflow_Checks_Suppressed (Etype (N)) then
10121 Enable_Overflow_Check (N);
10124 end Resolve_Op_Expon;
10126 --------------------
10127 -- Resolve_Op_Not --
10128 --------------------
10130 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
10133 function Parent_Is_Boolean return Boolean;
10134 -- This function determines if the parent node is a boolean operator or
10135 -- operation (comparison op, membership test, or short circuit form) and
10136 -- the not in question is the left operand of this operation. Note that
10137 -- if the not is in parens, then false is returned.
10139 -----------------------
10140 -- Parent_Is_Boolean --
10141 -----------------------
10143 function Parent_Is_Boolean return Boolean is
10145 if Paren_Count (N) /= 0 then
10149 case Nkind (Parent (N)) is
10164 return Left_Opnd (Parent (N)) = N;
10170 end Parent_Is_Boolean;
10172 -- Start of processing for Resolve_Op_Not
10175 -- Predefined operations on scalar types yield the base type. On the
10176 -- other hand, logical operations on arrays yield the type of the
10177 -- arguments (and the context).
10179 if Is_Array_Type (Typ) then
10182 B_Typ := Base_Type (Typ);
10185 -- Straightforward case of incorrect arguments
10187 if not Valid_Boolean_Arg (Typ) then
10188 Error_Msg_N ("invalid operand type for operator&", N);
10189 Set_Etype (N, Any_Type);
10192 -- Special case of probable missing parens
10194 elsif Typ = Universal_Integer or else Typ = Any_Modular then
10195 if Parent_Is_Boolean then
10197 ("operand of not must be enclosed in parentheses",
10201 ("no modular type available in this context", N);
10204 Set_Etype (N, Any_Type);
10207 -- OK resolution of NOT
10210 -- Warn if non-boolean types involved. This is a case like not a < b
10211 -- where a and b are modular, where we will get (not a) < b and most
10212 -- likely not (a < b) was intended.
10214 if Warn_On_Questionable_Missing_Parens
10215 and then not Is_Boolean_Type (Typ)
10216 and then Parent_Is_Boolean
10218 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
10221 -- Warn on double negation if checking redundant constructs
10223 if Warn_On_Redundant_Constructs
10224 and then Comes_From_Source (N)
10225 and then Comes_From_Source (Right_Opnd (N))
10226 and then Root_Type (Typ) = Standard_Boolean
10227 and then Nkind (Right_Opnd (N)) = N_Op_Not
10229 Error_Msg_N ("redundant double negation?r?", N);
10232 -- Complete resolution and evaluation of NOT
10233 -- If argument is an equality and expected type is boolean, that
10234 -- expected type has no effect on resolution, and there are
10235 -- special rules for resolution of Eq, Neq in the presence of
10236 -- overloaded operands, so we directly call its resolution routines.
10239 Opnd : constant Node_Id := Right_Opnd (N);
10243 if B_Typ = Standard_Boolean
10244 and then Nkind_In (Opnd, N_Op_Eq, N_Op_Ne)
10245 and then Is_Overloaded (Opnd)
10247 Resolve_Equality_Op (Opnd, B_Typ);
10248 Op_Id := Entity (Opnd);
10250 if Ekind (Op_Id) = E_Function
10251 and then not Is_Intrinsic_Subprogram (Op_Id)
10253 Rewrite_Operator_As_Call (Opnd, Op_Id);
10256 if not Inside_A_Generic or else Is_Entity_Name (Opnd) then
10257 Freeze_Expression (Opnd);
10263 Resolve (Opnd, B_Typ);
10266 Check_Unset_Reference (Opnd);
10269 Set_Etype (N, B_Typ);
10270 Generate_Operator_Reference (N, B_Typ);
10273 end Resolve_Op_Not;
10275 -----------------------------
10276 -- Resolve_Operator_Symbol --
10277 -----------------------------
10279 -- Nothing to be done, all resolved already
10281 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
10282 pragma Warnings (Off, N);
10283 pragma Warnings (Off, Typ);
10287 end Resolve_Operator_Symbol;
10289 ----------------------------------
10290 -- Resolve_Qualified_Expression --
10291 ----------------------------------
10293 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
10294 pragma Warnings (Off, Typ);
10296 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
10297 Expr : constant Node_Id := Expression (N);
10300 Resolve (Expr, Target_Typ);
10302 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10303 -- operation if not needed.
10305 if Restriction_Check_Required (SPARK_05)
10306 and then Is_Array_Type (Target_Typ)
10307 and then Is_Array_Type (Etype (Expr))
10308 and then Etype (Expr) /= Any_Composite -- or else Expr in error
10309 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
10311 Check_SPARK_05_Restriction
10312 ("array types should have matching static bounds", N);
10315 -- A qualified expression requires an exact match of the type, class-
10316 -- wide matching is not allowed. However, if the qualifying type is
10317 -- specific and the expression has a class-wide type, it may still be
10318 -- okay, since it can be the result of the expansion of a call to a
10319 -- dispatching function, so we also have to check class-wideness of the
10320 -- type of the expression's original node.
10322 if (Is_Class_Wide_Type (Target_Typ)
10324 (Is_Class_Wide_Type (Etype (Expr))
10325 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
10326 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
10328 Wrong_Type (Expr, Target_Typ);
10331 -- If the target type is unconstrained, then we reset the type of the
10332 -- result from the type of the expression. For other cases, the actual
10333 -- subtype of the expression is the target type.
10335 if Is_Composite_Type (Target_Typ)
10336 and then not Is_Constrained (Target_Typ)
10338 Set_Etype (N, Etype (Expr));
10341 Analyze_Dimension (N);
10342 Eval_Qualified_Expression (N);
10344 -- If we still have a qualified expression after the static evaluation,
10345 -- then apply a scalar range check if needed. The reason that we do this
10346 -- after the Eval call is that otherwise, the application of the range
10347 -- check may convert an illegal static expression and result in warning
10348 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
10350 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
10351 Apply_Scalar_Range_Check (Expr, Typ);
10354 -- Finally, check whether a predicate applies to the target type. This
10355 -- comes from AI12-0100. As for type conversions, check the enclosing
10356 -- context to prevent an infinite expansion.
10358 if Has_Predicates (Target_Typ) then
10359 if Nkind (Parent (N)) = N_Function_Call
10360 and then Present (Name (Parent (N)))
10361 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10363 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10367 -- In the case of a qualified expression in an allocator, the check
10368 -- is applied when expanding the allocator, so avoid redundant check.
10370 elsif Nkind (N) = N_Qualified_Expression
10371 and then Nkind (Parent (N)) /= N_Allocator
10373 Apply_Predicate_Check (N, Target_Typ);
10376 end Resolve_Qualified_Expression;
10378 ------------------------------
10379 -- Resolve_Raise_Expression --
10380 ------------------------------
10382 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
10384 if Typ = Raise_Type then
10385 Error_Msg_N ("cannot find unique type for raise expression", N);
10386 Set_Etype (N, Any_Type);
10388 Set_Etype (N, Typ);
10390 end Resolve_Raise_Expression;
10392 -------------------
10393 -- Resolve_Range --
10394 -------------------
10396 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
10397 L : constant Node_Id := Low_Bound (N);
10398 H : constant Node_Id := High_Bound (N);
10400 function First_Last_Ref return Boolean;
10401 -- Returns True if N is of the form X'First .. X'Last where X is the
10402 -- same entity for both attributes.
10404 --------------------
10405 -- First_Last_Ref --
10406 --------------------
10408 function First_Last_Ref return Boolean is
10409 Lorig : constant Node_Id := Original_Node (L);
10410 Horig : constant Node_Id := Original_Node (H);
10413 if Nkind (Lorig) = N_Attribute_Reference
10414 and then Nkind (Horig) = N_Attribute_Reference
10415 and then Attribute_Name (Lorig) = Name_First
10416 and then Attribute_Name (Horig) = Name_Last
10419 PL : constant Node_Id := Prefix (Lorig);
10420 PH : constant Node_Id := Prefix (Horig);
10422 if Is_Entity_Name (PL)
10423 and then Is_Entity_Name (PH)
10424 and then Entity (PL) = Entity (PH)
10432 end First_Last_Ref;
10434 -- Start of processing for Resolve_Range
10437 Set_Etype (N, Typ);
10439 -- The lower bound should be in Typ. The higher bound can be in Typ's
10440 -- base type if the range is null. It may still be invalid if it is
10441 -- higher than the lower bound. This is checked later in the context in
10442 -- which the range appears.
10445 Resolve (H, Base_Type (Typ));
10447 -- Reanalyze the lower bound after both bounds have been analyzed, so
10448 -- that the range is known to be static or not by now. This may trigger
10449 -- more compile-time evaluation, which is useful for static analysis
10450 -- with GNATprove. This is not needed for compilation or static analysis
10451 -- with CodePeer, as full expansion does that evaluation then.
10453 if GNATprove_Mode then
10454 Set_Analyzed (L, False);
10458 -- Check for inappropriate range on unordered enumeration type
10460 if Bad_Unordered_Enumeration_Reference (N, Typ)
10462 -- Exclude X'First .. X'Last if X is the same entity for both
10464 and then not First_Last_Ref
10466 Error_Msg_Sloc := Sloc (Typ);
10468 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
10471 Check_Unset_Reference (L);
10472 Check_Unset_Reference (H);
10474 -- We have to check the bounds for being within the base range as
10475 -- required for a non-static context. Normally this is automatic and
10476 -- done as part of evaluating expressions, but the N_Range node is an
10477 -- exception, since in GNAT we consider this node to be a subexpression,
10478 -- even though in Ada it is not. The circuit in Sem_Eval could check for
10479 -- this, but that would put the test on the main evaluation path for
10482 Check_Non_Static_Context (L);
10483 Check_Non_Static_Context (H);
10485 -- Check for an ambiguous range over character literals. This will
10486 -- happen with a membership test involving only literals.
10488 if Typ = Any_Character then
10489 Ambiguous_Character (L);
10490 Set_Etype (N, Any_Type);
10494 -- If bounds are static, constant-fold them, so size computations are
10495 -- identical between front-end and back-end. Do not perform this
10496 -- transformation while analyzing generic units, as type information
10497 -- would be lost when reanalyzing the constant node in the instance.
10499 if Is_Discrete_Type (Typ) and then Expander_Active then
10500 if Is_OK_Static_Expression (L) then
10501 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
10504 if Is_OK_Static_Expression (H) then
10505 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
10510 --------------------------
10511 -- Resolve_Real_Literal --
10512 --------------------------
10514 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
10515 Actual_Typ : constant Entity_Id := Etype (N);
10518 -- Special processing for fixed-point literals to make sure that the
10519 -- value is an exact multiple of small where this is required. We skip
10520 -- this for the universal real case, and also for generic types.
10522 if Is_Fixed_Point_Type (Typ)
10523 and then Typ /= Universal_Fixed
10524 and then Typ /= Any_Fixed
10525 and then not Is_Generic_Type (Typ)
10528 Val : constant Ureal := Realval (N);
10529 Cintr : constant Ureal := Val / Small_Value (Typ);
10530 Cint : constant Uint := UR_Trunc (Cintr);
10531 Den : constant Uint := Norm_Den (Cintr);
10535 -- Case of literal is not an exact multiple of the Small
10539 -- For a source program literal for a decimal fixed-point type,
10540 -- this is statically illegal (RM 4.9(36)).
10542 if Is_Decimal_Fixed_Point_Type (Typ)
10543 and then Actual_Typ = Universal_Real
10544 and then Comes_From_Source (N)
10546 Error_Msg_N ("value has extraneous low order digits", N);
10549 -- Generate a warning if literal from source
10551 if Is_OK_Static_Expression (N)
10552 and then Warn_On_Bad_Fixed_Value
10555 ("?b?static fixed-point value is not a multiple of Small!",
10559 -- Replace literal by a value that is the exact representation
10560 -- of a value of the type, i.e. a multiple of the small value,
10561 -- by truncation, since Machine_Rounds is false for all GNAT
10562 -- fixed-point types (RM 4.9(38)).
10564 Stat := Is_OK_Static_Expression (N);
10566 Make_Real_Literal (Sloc (N),
10567 Realval => Small_Value (Typ) * Cint));
10569 Set_Is_Static_Expression (N, Stat);
10572 -- In all cases, set the corresponding integer field
10574 Set_Corresponding_Integer_Value (N, Cint);
10578 -- Now replace the actual type by the expected type as usual
10580 Set_Etype (N, Typ);
10581 Eval_Real_Literal (N);
10582 end Resolve_Real_Literal;
10584 -----------------------
10585 -- Resolve_Reference --
10586 -----------------------
10588 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
10589 P : constant Node_Id := Prefix (N);
10592 -- Replace general access with specific type
10594 if Ekind (Etype (N)) = E_Allocator_Type then
10595 Set_Etype (N, Base_Type (Typ));
10598 Resolve (P, Designated_Type (Etype (N)));
10600 -- If we are taking the reference of a volatile entity, then treat it as
10601 -- a potential modification of this entity. This is too conservative,
10602 -- but necessary because remove side effects can cause transformations
10603 -- of normal assignments into reference sequences that otherwise fail to
10604 -- notice the modification.
10606 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
10607 Note_Possible_Modification (P, Sure => False);
10609 end Resolve_Reference;
10611 --------------------------------
10612 -- Resolve_Selected_Component --
10613 --------------------------------
10615 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
10617 Comp1 : Entity_Id := Empty; -- prevent junk warning
10618 P : constant Node_Id := Prefix (N);
10619 S : constant Node_Id := Selector_Name (N);
10620 T : Entity_Id := Etype (P);
10622 I1 : Interp_Index := 0; -- prevent junk warning
10627 function Init_Component return Boolean;
10628 -- Check whether this is the initialization of a component within an
10629 -- init proc (by assignment or call to another init proc). If true,
10630 -- there is no need for a discriminant check.
10632 --------------------
10633 -- Init_Component --
10634 --------------------
10636 function Init_Component return Boolean is
10638 return Inside_Init_Proc
10639 and then Nkind (Prefix (N)) = N_Identifier
10640 and then Chars (Prefix (N)) = Name_uInit
10641 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
10642 end Init_Component;
10644 -- Start of processing for Resolve_Selected_Component
10647 if Is_Overloaded (P) then
10649 -- Use the context type to select the prefix that has a selector
10650 -- of the correct name and type.
10653 Get_First_Interp (P, I, It);
10655 Search : while Present (It.Typ) loop
10656 if Is_Access_Type (It.Typ) then
10657 T := Designated_Type (It.Typ);
10662 -- Locate selected component. For a private prefix the selector
10663 -- can denote a discriminant.
10665 if Is_Record_Type (T) or else Is_Private_Type (T) then
10667 -- The visible components of a class-wide type are those of
10670 if Is_Class_Wide_Type (T) then
10674 Comp := First_Entity (T);
10675 while Present (Comp) loop
10676 if Chars (Comp) = Chars (S)
10677 and then Covers (Typ, Etype (Comp))
10686 It := Disambiguate (P, I1, I, Any_Type);
10688 if It = No_Interp then
10690 ("ambiguous prefix for selected component", N);
10691 Set_Etype (N, Typ);
10697 -- There may be an implicit dereference. Retrieve
10698 -- designated record type.
10700 if Is_Access_Type (It1.Typ) then
10701 T := Designated_Type (It1.Typ);
10706 if Scope (Comp1) /= T then
10708 -- Resolution chooses the new interpretation.
10709 -- Find the component with the right name.
10711 Comp1 := First_Entity (T);
10712 while Present (Comp1)
10713 and then Chars (Comp1) /= Chars (S)
10715 Comp1 := Next_Entity (Comp1);
10724 Comp := Next_Entity (Comp);
10728 Get_Next_Interp (I, It);
10731 -- There must be a legal interpretation at this point
10733 pragma Assert (Found);
10734 Resolve (P, It1.Typ);
10736 -- In general the expected type is the type of the context, not the
10737 -- type of the candidate selected component.
10739 Set_Etype (N, Typ);
10740 Set_Entity_With_Checks (S, Comp1);
10742 -- The type of the context and that of the component are
10743 -- compatible and in general identical, but if they are anonymous
10744 -- access-to-subprogram types, the relevant type is that of the
10745 -- component. This matters in Unnest_Subprograms mode, where the
10746 -- relevant context is the one in which the type is declared, not
10747 -- the point of use. This determines what activation record to use.
10749 if Ekind (Typ) = E_Anonymous_Access_Subprogram_Type then
10750 Set_Etype (N, Etype (Comp1));
10752 -- When the type of the component is an access to a class-wide type
10753 -- the relevant type is that of the component (since in such case we
10754 -- may need to generate implicit type conversions or dispatching
10757 elsif Is_Access_Type (Typ)
10758 and then not Is_Class_Wide_Type (Designated_Type (Typ))
10759 and then Is_Class_Wide_Type (Designated_Type (Etype (Comp1)))
10761 Set_Etype (N, Etype (Comp1));
10765 -- Resolve prefix with its type
10770 -- Generate cross-reference. We needed to wait until full overloading
10771 -- resolution was complete to do this, since otherwise we can't tell if
10772 -- we are an lvalue or not.
10774 if May_Be_Lvalue (N) then
10775 Generate_Reference (Entity (S), S, 'm');
10777 Generate_Reference (Entity (S), S, 'r');
10780 -- If prefix is an access type, the node will be transformed into an
10781 -- explicit dereference during expansion. The type of the node is the
10782 -- designated type of that of the prefix.
10784 if Is_Access_Type (Etype (P)) then
10785 T := Designated_Type (Etype (P));
10786 Check_Fully_Declared_Prefix (T, P);
10791 -- If the prefix is an entity it may have a deferred reference set
10792 -- during analysis of the selected component. After resolution we
10793 -- can transform it into a proper reference. This prevents spurious
10794 -- warnings on useless assignments when the same selected component
10795 -- is the actual for an out parameter in a subsequent call.
10797 if Is_Entity_Name (P)
10798 and then Has_Deferred_Reference (Entity (P))
10800 if May_Be_Lvalue (N) then
10801 Generate_Reference (Entity (P), P, 'm');
10803 Generate_Reference (Entity (P), P, 'r');
10808 -- Set flag for expander if discriminant check required on a component
10809 -- appearing within a variant.
10811 if Has_Discriminants (T)
10812 and then Ekind (Entity (S)) = E_Component
10813 and then Present (Original_Record_Component (Entity (S)))
10814 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
10816 Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
10817 and then not Discriminant_Checks_Suppressed (T)
10818 and then not Init_Component
10820 Set_Do_Discriminant_Check (N);
10823 if Ekind (Entity (S)) = E_Void then
10824 Error_Msg_N ("premature use of component", S);
10827 -- If the prefix is a record conversion, this may be a renamed
10828 -- discriminant whose bounds differ from those of the original
10829 -- one, so we must ensure that a range check is performed.
10831 if Nkind (P) = N_Type_Conversion
10832 and then Ekind (Entity (S)) = E_Discriminant
10833 and then Is_Discrete_Type (Typ)
10835 Set_Etype (N, Base_Type (Typ));
10838 -- Note: No Eval processing is required, because the prefix is of a
10839 -- record type, or protected type, and neither can possibly be static.
10841 -- If the record type is atomic, and the component is non-atomic, then
10842 -- this is worth a warning, since we have a situation where the access
10843 -- to the component may cause extra read/writes of the atomic array
10844 -- object, or partial word accesses, both of which may be unexpected.
10846 if Nkind (N) = N_Selected_Component
10847 and then Is_Atomic_Ref_With_Address (N)
10848 and then not Is_Atomic (Entity (S))
10849 and then not Is_Atomic (Etype (Entity (S)))
10852 ("??access to non-atomic component of atomic record",
10855 ("\??may cause unexpected accesses to atomic object",
10859 Analyze_Dimension (N);
10860 end Resolve_Selected_Component;
10862 -------------------
10863 -- Resolve_Shift --
10864 -------------------
10866 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
10867 B_Typ : constant Entity_Id := Base_Type (Typ);
10868 L : constant Node_Id := Left_Opnd (N);
10869 R : constant Node_Id := Right_Opnd (N);
10872 -- We do the resolution using the base type, because intermediate values
10873 -- in expressions always are of the base type, not a subtype of it.
10875 Resolve (L, B_Typ);
10876 Resolve (R, Standard_Natural);
10878 Check_Unset_Reference (L);
10879 Check_Unset_Reference (R);
10881 Set_Etype (N, B_Typ);
10882 Generate_Operator_Reference (N, B_Typ);
10886 ---------------------------
10887 -- Resolve_Short_Circuit --
10888 ---------------------------
10890 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
10891 B_Typ : constant Entity_Id := Base_Type (Typ);
10892 L : constant Node_Id := Left_Opnd (N);
10893 R : constant Node_Id := Right_Opnd (N);
10896 -- Ensure all actions associated with the left operand (e.g.
10897 -- finalization of transient objects) are fully evaluated locally within
10898 -- an expression with actions. This is particularly helpful for coverage
10899 -- analysis. However this should not happen in generics or if option
10900 -- Minimize_Expression_With_Actions is set.
10902 if Expander_Active and not Minimize_Expression_With_Actions then
10904 Reloc_L : constant Node_Id := Relocate_Node (L);
10906 Save_Interps (Old_N => L, New_N => Reloc_L);
10909 Make_Expression_With_Actions (Sloc (L),
10910 Actions => New_List,
10911 Expression => Reloc_L));
10913 -- Set Comes_From_Source on L to preserve warnings for unset
10916 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
10920 Resolve (L, B_Typ);
10921 Resolve (R, B_Typ);
10923 -- Check for issuing warning for always False assert/check, this happens
10924 -- when assertions are turned off, in which case the pragma Assert/Check
10925 -- was transformed into:
10927 -- if False and then <condition> then ...
10929 -- and we detect this pattern
10931 if Warn_On_Assertion_Failure
10932 and then Is_Entity_Name (R)
10933 and then Entity (R) = Standard_False
10934 and then Nkind (Parent (N)) = N_If_Statement
10935 and then Nkind (N) = N_And_Then
10936 and then Is_Entity_Name (L)
10937 and then Entity (L) = Standard_False
10940 Orig : constant Node_Id := Original_Node (Parent (N));
10943 -- Special handling of Asssert pragma
10945 if Nkind (Orig) = N_Pragma
10946 and then Pragma_Name (Orig) = Name_Assert
10949 Expr : constant Node_Id :=
10952 (First (Pragma_Argument_Associations (Orig))));
10955 -- Don't warn if original condition is explicit False,
10956 -- since obviously the failure is expected in this case.
10958 if Is_Entity_Name (Expr)
10959 and then Entity (Expr) = Standard_False
10963 -- Issue warning. We do not want the deletion of the
10964 -- IF/AND-THEN to take this message with it. We achieve this
10965 -- by making sure that the expanded code points to the Sloc
10966 -- of the expression, not the original pragma.
10969 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10970 -- The source location of the expression is not usually
10971 -- the best choice here. For example, it gets located on
10972 -- the last AND keyword in a chain of boolean expressiond
10973 -- AND'ed together. It is best to put the message on the
10974 -- first character of the assertion, which is the effect
10975 -- of the First_Node call here.
10978 ("?A?assertion would fail at run time!",
10980 (First (Pragma_Argument_Associations (Orig))));
10984 -- Similar processing for Check pragma
10986 elsif Nkind (Orig) = N_Pragma
10987 and then Pragma_Name (Orig) = Name_Check
10989 -- Don't want to warn if original condition is explicit False
10992 Expr : constant Node_Id :=
10995 (Next (First (Pragma_Argument_Associations (Orig)))));
10997 if Is_Entity_Name (Expr)
10998 and then Entity (Expr) = Standard_False
11005 -- Again use Error_Msg_F rather than Error_Msg_N, see
11006 -- comment above for an explanation of why we do this.
11009 ("?A?check would fail at run time!",
11011 (Last (Pragma_Argument_Associations (Orig))));
11018 -- Continue with processing of short circuit
11020 Check_Unset_Reference (L);
11021 Check_Unset_Reference (R);
11023 Set_Etype (N, B_Typ);
11024 Eval_Short_Circuit (N);
11025 end Resolve_Short_Circuit;
11027 -------------------
11028 -- Resolve_Slice --
11029 -------------------
11031 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
11032 Drange : constant Node_Id := Discrete_Range (N);
11033 Name : constant Node_Id := Prefix (N);
11034 Array_Type : Entity_Id := Empty;
11035 Dexpr : Node_Id := Empty;
11036 Index_Type : Entity_Id;
11039 if Is_Overloaded (Name) then
11041 -- Use the context type to select the prefix that yields the correct
11046 I1 : Interp_Index := 0;
11048 P : constant Node_Id := Prefix (N);
11049 Found : Boolean := False;
11052 Get_First_Interp (P, I, It);
11053 while Present (It.Typ) loop
11054 if (Is_Array_Type (It.Typ)
11055 and then Covers (Typ, It.Typ))
11056 or else (Is_Access_Type (It.Typ)
11057 and then Is_Array_Type (Designated_Type (It.Typ))
11058 and then Covers (Typ, Designated_Type (It.Typ)))
11061 It := Disambiguate (P, I1, I, Any_Type);
11063 if It = No_Interp then
11064 Error_Msg_N ("ambiguous prefix for slicing", N);
11065 Set_Etype (N, Typ);
11069 Array_Type := It.Typ;
11074 Array_Type := It.Typ;
11079 Get_Next_Interp (I, It);
11084 Array_Type := Etype (Name);
11087 Resolve (Name, Array_Type);
11089 if Is_Access_Type (Array_Type) then
11090 Apply_Access_Check (N);
11091 Array_Type := Designated_Type (Array_Type);
11093 -- If the prefix is an access to an unconstrained array, we must use
11094 -- the actual subtype of the object to perform the index checks. The
11095 -- object denoted by the prefix is implicit in the node, so we build
11096 -- an explicit representation for it in order to compute the actual
11099 if not Is_Constrained (Array_Type) then
11100 Remove_Side_Effects (Prefix (N));
11103 Obj : constant Node_Id :=
11104 Make_Explicit_Dereference (Sloc (N),
11105 Prefix => New_Copy_Tree (Prefix (N)));
11107 Set_Etype (Obj, Array_Type);
11108 Set_Parent (Obj, Parent (N));
11109 Array_Type := Get_Actual_Subtype (Obj);
11113 elsif Is_Entity_Name (Name)
11114 or else Nkind (Name) = N_Explicit_Dereference
11115 or else (Nkind (Name) = N_Function_Call
11116 and then not Is_Constrained (Etype (Name)))
11118 Array_Type := Get_Actual_Subtype (Name);
11120 -- If the name is a selected component that depends on discriminants,
11121 -- build an actual subtype for it. This can happen only when the name
11122 -- itself is overloaded; otherwise the actual subtype is created when
11123 -- the selected component is analyzed.
11125 elsif Nkind (Name) = N_Selected_Component
11126 and then Full_Analysis
11127 and then Depends_On_Discriminant (First_Index (Array_Type))
11130 Act_Decl : constant Node_Id :=
11131 Build_Actual_Subtype_Of_Component (Array_Type, Name);
11133 Insert_Action (N, Act_Decl);
11134 Array_Type := Defining_Identifier (Act_Decl);
11137 -- Maybe this should just be "else", instead of checking for the
11138 -- specific case of slice??? This is needed for the case where the
11139 -- prefix is an Image attribute, which gets expanded to a slice, and so
11140 -- has a constrained subtype which we want to use for the slice range
11141 -- check applied below (the range check won't get done if the
11142 -- unconstrained subtype of the 'Image is used).
11144 elsif Nkind (Name) = N_Slice then
11145 Array_Type := Etype (Name);
11148 -- Obtain the type of the array index
11150 if Ekind (Array_Type) = E_String_Literal_Subtype then
11151 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
11153 Index_Type := Etype (First_Index (Array_Type));
11156 -- If name was overloaded, set slice type correctly now
11158 Set_Etype (N, Array_Type);
11160 -- Handle the generation of a range check that compares the array index
11161 -- against the discrete_range. The check is not applied to internally
11162 -- built nodes associated with the expansion of dispatch tables. Check
11163 -- that Ada.Tags has already been loaded to avoid extra dependencies on
11166 if Tagged_Type_Expansion
11167 and then RTU_Loaded (Ada_Tags)
11168 and then Nkind (Prefix (N)) = N_Selected_Component
11169 and then Present (Entity (Selector_Name (Prefix (N))))
11170 and then Entity (Selector_Name (Prefix (N))) =
11171 RTE_Record_Component (RE_Prims_Ptr)
11175 -- The discrete_range is specified by a subtype indication. Create a
11176 -- shallow copy and inherit the type, parent and source location from
11177 -- the discrete_range. This ensures that the range check is inserted
11178 -- relative to the slice and that the runtime exception points to the
11179 -- proper construct.
11181 elsif Is_Entity_Name (Drange) then
11182 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
11184 Set_Etype (Dexpr, Etype (Drange));
11185 Set_Parent (Dexpr, Parent (Drange));
11186 Set_Sloc (Dexpr, Sloc (Drange));
11188 -- The discrete_range is a regular range. Resolve the bounds and remove
11189 -- their side effects.
11192 Resolve (Drange, Base_Type (Index_Type));
11194 if Nkind (Drange) = N_Range then
11195 Force_Evaluation (Low_Bound (Drange));
11196 Force_Evaluation (High_Bound (Drange));
11202 if Present (Dexpr) then
11203 Apply_Range_Check (Dexpr, Index_Type);
11206 Set_Slice_Subtype (N);
11208 -- Check bad use of type with predicates
11214 if Nkind (Drange) = N_Subtype_Indication
11215 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
11217 Subt := Entity (Subtype_Mark (Drange));
11219 Subt := Etype (Drange);
11222 if Has_Predicates (Subt) then
11223 Bad_Predicated_Subtype_Use
11224 ("subtype& has predicate, not allowed in slice", Drange, Subt);
11228 -- Otherwise here is where we check suspicious indexes
11230 if Nkind (Drange) = N_Range then
11231 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
11232 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
11235 Analyze_Dimension (N);
11239 ----------------------------
11240 -- Resolve_String_Literal --
11241 ----------------------------
11243 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
11244 C_Typ : constant Entity_Id := Component_Type (Typ);
11245 R_Typ : constant Entity_Id := Root_Type (C_Typ);
11246 Loc : constant Source_Ptr := Sloc (N);
11247 Str : constant String_Id := Strval (N);
11248 Strlen : constant Nat := String_Length (Str);
11249 Subtype_Id : Entity_Id;
11250 Need_Check : Boolean;
11253 -- For a string appearing in a concatenation, defer creation of the
11254 -- string_literal_subtype until the end of the resolution of the
11255 -- concatenation, because the literal may be constant-folded away. This
11256 -- is a useful optimization for long concatenation expressions.
11258 -- If the string is an aggregate built for a single character (which
11259 -- happens in a non-static context) or a is null string to which special
11260 -- checks may apply, we build the subtype. Wide strings must also get a
11261 -- string subtype if they come from a one character aggregate. Strings
11262 -- generated by attributes might be static, but it is often hard to
11263 -- determine whether the enclosing context is static, so we generate
11264 -- subtypes for them as well, thus losing some rarer optimizations ???
11265 -- Same for strings that come from a static conversion.
11268 (Strlen = 0 and then Typ /= Standard_String)
11269 or else Nkind (Parent (N)) /= N_Op_Concat
11270 or else (N /= Left_Opnd (Parent (N))
11271 and then N /= Right_Opnd (Parent (N)))
11272 or else ((Typ = Standard_Wide_String
11273 or else Typ = Standard_Wide_Wide_String)
11274 and then Nkind (Original_Node (N)) /= N_String_Literal);
11276 -- If the resolving type is itself a string literal subtype, we can just
11277 -- reuse it, since there is no point in creating another.
11279 if Ekind (Typ) = E_String_Literal_Subtype then
11282 elsif Nkind (Parent (N)) = N_Op_Concat
11283 and then not Need_Check
11284 and then not Nkind_In (Original_Node (N), N_Character_Literal,
11285 N_Attribute_Reference,
11286 N_Qualified_Expression,
11291 -- Do not generate a string literal subtype for the default expression
11292 -- of a formal parameter in GNATprove mode. This is because the string
11293 -- subtype is associated with the freezing actions of the subprogram,
11294 -- however freezing is disabled in GNATprove mode and as a result the
11295 -- subtype is unavailable.
11297 elsif GNATprove_Mode
11298 and then Nkind (Parent (N)) = N_Parameter_Specification
11302 -- Otherwise we must create a string literal subtype. Note that the
11303 -- whole idea of string literal subtypes is simply to avoid the need
11304 -- for building a full fledged array subtype for each literal.
11307 Set_String_Literal_Subtype (N, Typ);
11308 Subtype_Id := Etype (N);
11311 if Nkind (Parent (N)) /= N_Op_Concat
11314 Set_Etype (N, Subtype_Id);
11315 Eval_String_Literal (N);
11318 if Is_Limited_Composite (Typ)
11319 or else Is_Private_Composite (Typ)
11321 Error_Msg_N ("string literal not available for private array", N);
11322 Set_Etype (N, Any_Type);
11326 -- The validity of a null string has been checked in the call to
11327 -- Eval_String_Literal.
11332 -- Always accept string literal with component type Any_Character, which
11333 -- occurs in error situations and in comparisons of literals, both of
11334 -- which should accept all literals.
11336 elsif R_Typ = Any_Character then
11339 -- If the type is bit-packed, then we always transform the string
11340 -- literal into a full fledged aggregate.
11342 elsif Is_Bit_Packed_Array (Typ) then
11345 -- Deal with cases of Wide_Wide_String, Wide_String, and String
11348 -- For Standard.Wide_Wide_String, or any other type whose component
11349 -- type is Standard.Wide_Wide_Character, we know that all the
11350 -- characters in the string must be acceptable, since the parser
11351 -- accepted the characters as valid character literals.
11353 if R_Typ = Standard_Wide_Wide_Character then
11356 -- For the case of Standard.String, or any other type whose component
11357 -- type is Standard.Character, we must make sure that there are no
11358 -- wide characters in the string, i.e. that it is entirely composed
11359 -- of characters in range of type Character.
11361 -- If the string literal is the result of a static concatenation, the
11362 -- test has already been performed on the components, and need not be
11365 elsif R_Typ = Standard_Character
11366 and then Nkind (Original_Node (N)) /= N_Op_Concat
11368 for J in 1 .. Strlen loop
11369 if not In_Character_Range (Get_String_Char (Str, J)) then
11371 -- If we are out of range, post error. This is one of the
11372 -- very few places that we place the flag in the middle of
11373 -- a token, right under the offending wide character. Not
11374 -- quite clear if this is right wrt wide character encoding
11375 -- sequences, but it's only an error message.
11378 ("literal out of range of type Standard.Character",
11379 Source_Ptr (Int (Loc) + J));
11384 -- For the case of Standard.Wide_String, or any other type whose
11385 -- component type is Standard.Wide_Character, we must make sure that
11386 -- there are no wide characters in the string, i.e. that it is
11387 -- entirely composed of characters in range of type Wide_Character.
11389 -- If the string literal is the result of a static concatenation,
11390 -- the test has already been performed on the components, and need
11391 -- not be repeated.
11393 elsif R_Typ = Standard_Wide_Character
11394 and then Nkind (Original_Node (N)) /= N_Op_Concat
11396 for J in 1 .. Strlen loop
11397 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
11399 -- If we are out of range, post error. This is one of the
11400 -- very few places that we place the flag in the middle of
11401 -- a token, right under the offending wide character.
11403 -- This is not quite right, because characters in general
11404 -- will take more than one character position ???
11407 ("literal out of range of type Standard.Wide_Character",
11408 Source_Ptr (Int (Loc) + J));
11413 -- If the root type is not a standard character, then we will convert
11414 -- the string into an aggregate and will let the aggregate code do
11415 -- the checking. Standard Wide_Wide_Character is also OK here.
11421 -- See if the component type of the array corresponding to the string
11422 -- has compile time known bounds. If yes we can directly check
11423 -- whether the evaluation of the string will raise constraint error.
11424 -- Otherwise we need to transform the string literal into the
11425 -- corresponding character aggregate and let the aggregate code do
11426 -- the checking. We use the same transformation if the component
11427 -- type has a static predicate, which will be applied to each
11428 -- character when the aggregate is resolved.
11430 if Is_Standard_Character_Type (R_Typ) then
11432 -- Check for the case of full range, where we are definitely OK
11434 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
11438 -- Here the range is not the complete base type range, so check
11441 Comp_Typ_Lo : constant Node_Id :=
11442 Type_Low_Bound (Component_Type (Typ));
11443 Comp_Typ_Hi : constant Node_Id :=
11444 Type_High_Bound (Component_Type (Typ));
11449 if Compile_Time_Known_Value (Comp_Typ_Lo)
11450 and then Compile_Time_Known_Value (Comp_Typ_Hi)
11452 for J in 1 .. Strlen loop
11453 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
11455 if Char_Val < Expr_Value (Comp_Typ_Lo)
11456 or else Char_Val > Expr_Value (Comp_Typ_Hi)
11458 Apply_Compile_Time_Constraint_Error
11459 (N, "character out of range??",
11460 CE_Range_Check_Failed,
11461 Loc => Source_Ptr (Int (Loc) + J));
11465 if not Has_Static_Predicate (C_Typ) then
11473 -- If we got here we meed to transform the string literal into the
11474 -- equivalent qualified positional array aggregate. This is rather
11475 -- heavy artillery for this situation, but it is hard work to avoid.
11478 Lits : constant List_Id := New_List;
11479 P : Source_Ptr := Loc + 1;
11483 -- Build the character literals, we give them source locations that
11484 -- correspond to the string positions, which is a bit tricky given
11485 -- the possible presence of wide character escape sequences.
11487 for J in 1 .. Strlen loop
11488 C := Get_String_Char (Str, J);
11489 Set_Character_Literal_Name (C);
11492 Make_Character_Literal (P,
11493 Chars => Name_Find,
11494 Char_Literal_Value => UI_From_CC (C)));
11496 if In_Character_Range (C) then
11499 -- Should we have a call to Skip_Wide here ???
11508 Make_Qualified_Expression (Loc,
11509 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
11511 Make_Aggregate (Loc, Expressions => Lits)));
11513 Analyze_And_Resolve (N, Typ);
11515 end Resolve_String_Literal;
11517 -------------------------
11518 -- Resolve_Target_Name --
11519 -------------------------
11521 procedure Resolve_Target_Name (N : Node_Id; Typ : Entity_Id) is
11523 Set_Etype (N, Typ);
11524 end Resolve_Target_Name;
11526 -----------------------------
11527 -- Resolve_Type_Conversion --
11528 -----------------------------
11530 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
11531 Conv_OK : constant Boolean := Conversion_OK (N);
11532 Operand : constant Node_Id := Expression (N);
11533 Operand_Typ : constant Entity_Id := Etype (Operand);
11534 Target_Typ : constant Entity_Id := Etype (N);
11539 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
11540 -- Set to False to suppress cases where we want to suppress the test
11541 -- for redundancy to avoid possible false positives on this warning.
11545 and then not Valid_Conversion (N, Target_Typ, Operand)
11550 -- If the Operand Etype is Universal_Fixed, then the conversion is
11551 -- never redundant. We need this check because by the time we have
11552 -- finished the rather complex transformation, the conversion looks
11553 -- redundant when it is not.
11555 if Operand_Typ = Universal_Fixed then
11556 Test_Redundant := False;
11558 -- If the operand is marked as Any_Fixed, then special processing is
11559 -- required. This is also a case where we suppress the test for a
11560 -- redundant conversion, since most certainly it is not redundant.
11562 elsif Operand_Typ = Any_Fixed then
11563 Test_Redundant := False;
11565 -- Mixed-mode operation involving a literal. Context must be a fixed
11566 -- type which is applied to the literal subsequently.
11568 -- Multiplication and division involving two fixed type operands must
11569 -- yield a universal real because the result is computed in arbitrary
11572 if Is_Fixed_Point_Type (Typ)
11573 and then Nkind_In (Operand, N_Op_Divide, N_Op_Multiply)
11574 and then Etype (Left_Opnd (Operand)) = Any_Fixed
11575 and then Etype (Right_Opnd (Operand)) = Any_Fixed
11577 Set_Etype (Operand, Universal_Real);
11579 elsif Is_Numeric_Type (Typ)
11580 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
11581 and then (Etype (Right_Opnd (Operand)) = Universal_Real
11583 Etype (Left_Opnd (Operand)) = Universal_Real)
11585 -- Return if expression is ambiguous
11587 if Unique_Fixed_Point_Type (N) = Any_Type then
11590 -- If nothing else, the available fixed type is Duration
11593 Set_Etype (Operand, Standard_Duration);
11596 -- Resolve the real operand with largest available precision
11598 if Etype (Right_Opnd (Operand)) = Universal_Real then
11599 Rop := New_Copy_Tree (Right_Opnd (Operand));
11601 Rop := New_Copy_Tree (Left_Opnd (Operand));
11604 Resolve (Rop, Universal_Real);
11606 -- If the operand is a literal (it could be a non-static and
11607 -- illegal exponentiation) check whether the use of Duration
11608 -- is potentially inaccurate.
11610 if Nkind (Rop) = N_Real_Literal
11611 and then Realval (Rop) /= Ureal_0
11612 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
11615 ("??universal real operand can only "
11616 & "be interpreted as Duration!", Rop);
11618 ("\??precision will be lost in the conversion!", Rop);
11621 elsif Is_Numeric_Type (Typ)
11622 and then Nkind (Operand) in N_Op
11623 and then Unique_Fixed_Point_Type (N) /= Any_Type
11625 Set_Etype (Operand, Standard_Duration);
11628 Error_Msg_N ("invalid context for mixed mode operation", N);
11629 Set_Etype (Operand, Any_Type);
11636 -- In SPARK, a type conversion between array types should be restricted
11637 -- to types which have matching static bounds.
11639 -- Protect call to Matching_Static_Array_Bounds to avoid costly
11640 -- operation if not needed.
11642 if Restriction_Check_Required (SPARK_05)
11643 and then Is_Array_Type (Target_Typ)
11644 and then Is_Array_Type (Operand_Typ)
11645 and then Operand_Typ /= Any_Composite -- or else Operand in error
11646 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
11648 Check_SPARK_05_Restriction
11649 ("array types should have matching static bounds", N);
11652 -- In formal mode, the operand of an ancestor type conversion must be an
11653 -- object (not an expression).
11655 if Is_Tagged_Type (Target_Typ)
11656 and then not Is_Class_Wide_Type (Target_Typ)
11657 and then Is_Tagged_Type (Operand_Typ)
11658 and then not Is_Class_Wide_Type (Operand_Typ)
11659 and then Is_Ancestor (Target_Typ, Operand_Typ)
11660 and then not Is_SPARK_05_Object_Reference (Operand)
11662 Check_SPARK_05_Restriction ("object required", Operand);
11665 Analyze_Dimension (N);
11667 -- Note: we do the Eval_Type_Conversion call before applying the
11668 -- required checks for a subtype conversion. This is important, since
11669 -- both are prepared under certain circumstances to change the type
11670 -- conversion to a constraint error node, but in the case of
11671 -- Eval_Type_Conversion this may reflect an illegality in the static
11672 -- case, and we would miss the illegality (getting only a warning
11673 -- message), if we applied the type conversion checks first.
11675 Eval_Type_Conversion (N);
11677 -- Even when evaluation is not possible, we may be able to simplify the
11678 -- conversion or its expression. This needs to be done before applying
11679 -- checks, since otherwise the checks may use the original expression
11680 -- and defeat the simplifications. This is specifically the case for
11681 -- elimination of the floating-point Truncation attribute in
11682 -- float-to-int conversions.
11684 Simplify_Type_Conversion (N);
11686 -- If after evaluation we still have a type conversion, then we may need
11687 -- to apply checks required for a subtype conversion.
11689 -- Skip these type conversion checks if universal fixed operands
11690 -- operands involved, since range checks are handled separately for
11691 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
11693 if Nkind (N) = N_Type_Conversion
11694 and then not Is_Generic_Type (Root_Type (Target_Typ))
11695 and then Target_Typ /= Universal_Fixed
11696 and then Operand_Typ /= Universal_Fixed
11698 Apply_Type_Conversion_Checks (N);
11701 -- Issue warning for conversion of simple object to its own type. We
11702 -- have to test the original nodes, since they may have been rewritten
11703 -- by various optimizations.
11705 Orig_N := Original_Node (N);
11707 -- Here we test for a redundant conversion if the warning mode is
11708 -- active (and was not locally reset), and we have a type conversion
11709 -- from source not appearing in a generic instance.
11712 and then Nkind (Orig_N) = N_Type_Conversion
11713 and then Comes_From_Source (Orig_N)
11714 and then not In_Instance
11716 Orig_N := Original_Node (Expression (Orig_N));
11717 Orig_T := Target_Typ;
11719 -- If the node is part of a larger expression, the Target_Type
11720 -- may not be the original type of the node if the context is a
11721 -- condition. Recover original type to see if conversion is needed.
11723 if Is_Boolean_Type (Orig_T)
11724 and then Nkind (Parent (N)) in N_Op
11726 Orig_T := Etype (Parent (N));
11729 -- If we have an entity name, then give the warning if the entity
11730 -- is the right type, or if it is a loop parameter covered by the
11731 -- original type (that's needed because loop parameters have an
11732 -- odd subtype coming from the bounds).
11734 if (Is_Entity_Name (Orig_N)
11736 (Etype (Entity (Orig_N)) = Orig_T
11738 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
11739 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
11741 -- If not an entity, then type of expression must match
11743 or else Etype (Orig_N) = Orig_T
11745 -- One more check, do not give warning if the analyzed conversion
11746 -- has an expression with non-static bounds, and the bounds of the
11747 -- target are static. This avoids junk warnings in cases where the
11748 -- conversion is necessary to establish staticness, for example in
11749 -- a case statement.
11751 if not Is_OK_Static_Subtype (Operand_Typ)
11752 and then Is_OK_Static_Subtype (Target_Typ)
11756 -- Finally, if this type conversion occurs in a context requiring
11757 -- a prefix, and the expression is a qualified expression then the
11758 -- type conversion is not redundant, since a qualified expression
11759 -- is not a prefix, whereas a type conversion is. For example, "X
11760 -- := T'(Funx(...)).Y;" is illegal because a selected component
11761 -- requires a prefix, but a type conversion makes it legal: "X :=
11762 -- T(T'(Funx(...))).Y;"
11764 -- In Ada 2012, a qualified expression is a name, so this idiom is
11765 -- no longer needed, but we still suppress the warning because it
11766 -- seems unfriendly for warnings to pop up when you switch to the
11767 -- newer language version.
11769 elsif Nkind (Orig_N) = N_Qualified_Expression
11770 and then Nkind_In (Parent (N), N_Attribute_Reference,
11771 N_Indexed_Component,
11772 N_Selected_Component,
11774 N_Explicit_Dereference)
11778 -- Never warn on conversion to Long_Long_Integer'Base since
11779 -- that is most likely an artifact of the extended overflow
11780 -- checking and comes from complex expanded code.
11782 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
11785 -- Here we give the redundant conversion warning. If it is an
11786 -- entity, give the name of the entity in the message. If not,
11787 -- just mention the expression.
11789 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
11792 if Is_Entity_Name (Orig_N) then
11793 Error_Msg_Node_2 := Orig_T;
11794 Error_Msg_NE -- CODEFIX
11795 ("??redundant conversion, & is of type &!",
11796 N, Entity (Orig_N));
11799 ("??redundant conversion, expression is of type&!",
11806 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
11807 -- No need to perform any interface conversion if the type of the
11808 -- expression coincides with the target type.
11810 if Ada_Version >= Ada_2005
11811 and then Expander_Active
11812 and then Operand_Typ /= Target_Typ
11815 Opnd : Entity_Id := Operand_Typ;
11816 Target : Entity_Id := Target_Typ;
11819 -- If the type of the operand is a limited view, use nonlimited
11820 -- view when available. If it is a class-wide type, recover the
11821 -- class-wide type of the nonlimited view.
11823 if From_Limited_With (Opnd)
11824 and then Has_Non_Limited_View (Opnd)
11826 Opnd := Non_Limited_View (Opnd);
11827 Set_Etype (Expression (N), Opnd);
11830 -- It seems that Non_Limited_View should also be applied for
11831 -- Target when it has a limited view, but that leads to missing
11832 -- error checks on interface conversions further below. ???
11834 if Is_Access_Type (Opnd) then
11835 Opnd := Designated_Type (Opnd);
11837 -- If the type of the operand is a limited view, use nonlimited
11838 -- view when available. If it is a class-wide type, recover the
11839 -- class-wide type of the nonlimited view.
11841 if From_Limited_With (Opnd)
11842 and then Has_Non_Limited_View (Opnd)
11844 Opnd := Non_Limited_View (Opnd);
11848 if Is_Access_Type (Target_Typ) then
11849 Target := Designated_Type (Target);
11851 -- If the target type is a limited view, use nonlimited view
11854 if From_Limited_With (Target)
11855 and then Has_Non_Limited_View (Target)
11857 Target := Non_Limited_View (Target);
11861 if Opnd = Target then
11864 -- Conversion from interface type
11866 -- It seems that it would be better for the error checks below
11867 -- to be performed as part of Validate_Conversion (and maybe some
11868 -- of the error checks above could be moved as well?). ???
11870 elsif Is_Interface (Opnd) then
11872 -- Ada 2005 (AI-217): Handle entities from limited views
11874 if From_Limited_With (Opnd) then
11875 Error_Msg_Qual_Level := 99;
11876 Error_Msg_NE -- CODEFIX
11877 ("missing WITH clause on package &", N,
11878 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
11880 ("type conversions require visibility of the full view",
11883 elsif From_Limited_With (Target)
11885 (Is_Access_Type (Target_Typ)
11886 and then Present (Non_Limited_View (Etype (Target))))
11888 Error_Msg_Qual_Level := 99;
11889 Error_Msg_NE -- CODEFIX
11890 ("missing WITH clause on package &", N,
11891 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
11893 ("type conversions require visibility of the full view",
11897 Expand_Interface_Conversion (N);
11900 -- Conversion to interface type
11902 elsif Is_Interface (Target) then
11906 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
11907 Opnd := Etype (Opnd);
11910 if Is_Class_Wide_Type (Opnd)
11911 or else Interface_Present_In_Ancestor
11915 Expand_Interface_Conversion (N);
11917 Error_Msg_Name_1 := Chars (Etype (Target));
11918 Error_Msg_Name_2 := Chars (Opnd);
11920 ("wrong interface conversion (% is not a progenitor "
11927 -- Ada 2012: once the type conversion is resolved, check whether the
11928 -- operand statisfies the static predicate of the target type.
11930 if Has_Predicates (Target_Typ) then
11931 Check_Expression_Against_Static_Predicate (N, Target_Typ);
11934 -- If at this stage we have a real to integer conversion, make sure that
11935 -- the Do_Range_Check flag is set, because such conversions in general
11936 -- need a range check. We only need this if expansion is off.
11937 -- In GNATprove mode, we only do that when converting from fixed-point
11938 -- (as floating-point to integer conversions are now handled in
11939 -- GNATprove mode).
11941 if Nkind (N) = N_Type_Conversion
11942 and then not Expander_Active
11943 and then Is_Integer_Type (Target_Typ)
11944 and then (Is_Fixed_Point_Type (Operand_Typ)
11945 or else (not GNATprove_Mode
11946 and then Is_Floating_Point_Type (Operand_Typ)))
11947 and then not Range_Checks_Suppressed (Target_Typ)
11948 and then not Range_Checks_Suppressed (Operand_Typ)
11950 Set_Do_Range_Check (Operand);
11953 -- Generating C code a type conversion of an access to constrained
11954 -- array type to access to unconstrained array type involves building
11955 -- a fat pointer which in general cannot be generated on the fly. We
11956 -- remove side effects in order to store the result of the conversion
11957 -- into a temporary.
11959 if Modify_Tree_For_C
11960 and then Nkind (N) = N_Type_Conversion
11961 and then Nkind (Parent (N)) /= N_Object_Declaration
11962 and then Is_Access_Type (Etype (N))
11963 and then Is_Array_Type (Designated_Type (Etype (N)))
11964 and then not Is_Constrained (Designated_Type (Etype (N)))
11965 and then Is_Constrained (Designated_Type (Etype (Expression (N))))
11967 Remove_Side_Effects (N);
11969 end Resolve_Type_Conversion;
11971 ----------------------
11972 -- Resolve_Unary_Op --
11973 ----------------------
11975 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
11976 B_Typ : constant Entity_Id := Base_Type (Typ);
11977 R : constant Node_Id := Right_Opnd (N);
11983 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
11984 Error_Msg_Name_1 := Chars (Typ);
11985 Check_SPARK_05_Restriction
11986 ("unary operator not defined for modular type%", N);
11989 -- Deal with intrinsic unary operators
11991 if Comes_From_Source (N)
11992 and then Ekind (Entity (N)) = E_Function
11993 and then Is_Imported (Entity (N))
11994 and then Is_Intrinsic_Subprogram (Entity (N))
11996 Resolve_Intrinsic_Unary_Operator (N, Typ);
12000 -- Deal with universal cases
12002 if Etype (R) = Universal_Integer
12004 Etype (R) = Universal_Real
12006 Check_For_Visible_Operator (N, B_Typ);
12009 Set_Etype (N, B_Typ);
12010 Resolve (R, B_Typ);
12012 -- Generate warning for expressions like abs (x mod 2)
12014 if Warn_On_Redundant_Constructs
12015 and then Nkind (N) = N_Op_Abs
12017 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
12019 if OK and then Hi >= Lo and then Lo >= 0 then
12020 Error_Msg_N -- CODEFIX
12021 ("?r?abs applied to known non-negative value has no effect", N);
12025 -- Deal with reference generation
12027 Check_Unset_Reference (R);
12028 Generate_Operator_Reference (N, B_Typ);
12029 Analyze_Dimension (N);
12032 -- Set overflow checking bit. Much cleverer code needed here eventually
12033 -- and perhaps the Resolve routines should be separated for the various
12034 -- arithmetic operations, since they will need different processing ???
12036 if Nkind (N) in N_Op then
12037 if not Overflow_Checks_Suppressed (Etype (N)) then
12038 Enable_Overflow_Check (N);
12042 -- Generate warning for expressions like -5 mod 3 for integers. No need
12043 -- to worry in the floating-point case, since parens do not affect the
12044 -- result so there is no point in giving in a warning.
12047 Norig : constant Node_Id := Original_Node (N);
12056 if Warn_On_Questionable_Missing_Parens
12057 and then Comes_From_Source (Norig)
12058 and then Is_Integer_Type (Typ)
12059 and then Nkind (Norig) = N_Op_Minus
12061 Rorig := Original_Node (Right_Opnd (Norig));
12063 -- We are looking for cases where the right operand is not
12064 -- parenthesized, and is a binary operator, multiply, divide, or
12065 -- mod. These are the cases where the grouping can affect results.
12067 if Paren_Count (Rorig) = 0
12068 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
12070 -- For mod, we always give the warning, since the value is
12071 -- affected by the parenthesization (e.g. (-5) mod 315 /=
12072 -- -(5 mod 315)). But for the other cases, the only concern is
12073 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
12074 -- overflows, but (-2) * 64 does not). So we try to give the
12075 -- message only when overflow is possible.
12077 if Nkind (Rorig) /= N_Op_Mod
12078 and then Compile_Time_Known_Value (R)
12080 Val := Expr_Value (R);
12082 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
12083 HB := Expr_Value (Type_High_Bound (Typ));
12085 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
12088 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
12089 LB := Expr_Value (Type_Low_Bound (Typ));
12091 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
12094 -- Note that the test below is deliberately excluding the
12095 -- largest negative number, since that is a potentially
12096 -- troublesome case (e.g. -2 * x, where the result is the
12097 -- largest negative integer has an overflow with 2 * x).
12099 if Val > LB and then Val <= HB then
12104 -- For the multiplication case, the only case we have to worry
12105 -- about is when (-a)*b is exactly the largest negative number
12106 -- so that -(a*b) can cause overflow. This can only happen if
12107 -- a is a power of 2, and more generally if any operand is a
12108 -- constant that is not a power of 2, then the parentheses
12109 -- cannot affect whether overflow occurs. We only bother to
12110 -- test the left most operand
12112 -- Loop looking at left operands for one that has known value
12115 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
12116 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
12117 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
12119 -- Operand value of 0 or 1 skips warning
12124 -- Otherwise check power of 2, if power of 2, warn, if
12125 -- anything else, skip warning.
12128 while Lval /= 2 loop
12129 if Lval mod 2 = 1 then
12140 -- Keep looking at left operands
12142 Opnd := Left_Opnd (Opnd);
12143 end loop Opnd_Loop;
12145 -- For rem or "/" we can only have a problematic situation
12146 -- if the divisor has a value of minus one or one. Otherwise
12147 -- overflow is impossible (divisor > 1) or we have a case of
12148 -- division by zero in any case.
12150 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
12151 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
12152 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
12157 -- If we fall through warning should be issued
12159 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
12162 ("??unary minus expression should be parenthesized here!", N);
12166 end Resolve_Unary_Op;
12168 ----------------------------------
12169 -- Resolve_Unchecked_Expression --
12170 ----------------------------------
12172 procedure Resolve_Unchecked_Expression
12177 Resolve (Expression (N), Typ, Suppress => All_Checks);
12178 Set_Etype (N, Typ);
12179 end Resolve_Unchecked_Expression;
12181 ---------------------------------------
12182 -- Resolve_Unchecked_Type_Conversion --
12183 ---------------------------------------
12185 procedure Resolve_Unchecked_Type_Conversion
12189 pragma Warnings (Off, Typ);
12191 Operand : constant Node_Id := Expression (N);
12192 Opnd_Type : constant Entity_Id := Etype (Operand);
12195 -- Resolve operand using its own type
12197 Resolve (Operand, Opnd_Type);
12199 -- In an inlined context, the unchecked conversion may be applied
12200 -- to a literal, in which case its type is the type of the context.
12201 -- (In other contexts conversions cannot apply to literals).
12204 and then (Opnd_Type = Any_Character or else
12205 Opnd_Type = Any_Integer or else
12206 Opnd_Type = Any_Real)
12208 Set_Etype (Operand, Typ);
12211 Analyze_Dimension (N);
12212 Eval_Unchecked_Conversion (N);
12213 end Resolve_Unchecked_Type_Conversion;
12215 ------------------------------
12216 -- Rewrite_Operator_As_Call --
12217 ------------------------------
12219 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
12220 Loc : constant Source_Ptr := Sloc (N);
12221 Actuals : constant List_Id := New_List;
12225 if Nkind (N) in N_Binary_Op then
12226 Append (Left_Opnd (N), Actuals);
12229 Append (Right_Opnd (N), Actuals);
12232 Make_Function_Call (Sloc => Loc,
12233 Name => New_Occurrence_Of (Nam, Loc),
12234 Parameter_Associations => Actuals);
12236 Preserve_Comes_From_Source (New_N, N);
12237 Preserve_Comes_From_Source (Name (New_N), N);
12238 Rewrite (N, New_N);
12239 Set_Etype (N, Etype (Nam));
12240 end Rewrite_Operator_As_Call;
12242 ------------------------------
12243 -- Rewrite_Renamed_Operator --
12244 ------------------------------
12246 procedure Rewrite_Renamed_Operator
12251 Nam : constant Name_Id := Chars (Op);
12252 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
12256 -- Do not perform this transformation within a pre/postcondition,
12257 -- because the expression will be reanalyzed, and the transformation
12258 -- might affect the visibility of the operator, e.g. in an instance.
12259 -- Note that fully analyzed and expanded pre/postconditions appear as
12260 -- pragma Check equivalents.
12262 if In_Pre_Post_Condition (N) then
12266 -- Likewise when an expression function is being preanalyzed, since the
12267 -- expression will be reanalyzed as part of the generated body.
12269 if In_Spec_Expression then
12271 S : constant Entity_Id := Current_Scope_No_Loops;
12273 if Ekind (S) = E_Function
12274 and then Nkind (Original_Node (Unit_Declaration_Node (S))) =
12275 N_Expression_Function
12282 -- Rewrite the operator node using the real operator, not its renaming.
12283 -- Exclude user-defined intrinsic operations of the same name, which are
12284 -- treated separately and rewritten as calls.
12286 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
12287 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
12288 Set_Chars (Op_Node, Nam);
12289 Set_Etype (Op_Node, Etype (N));
12290 Set_Entity (Op_Node, Op);
12291 Set_Right_Opnd (Op_Node, Right_Opnd (N));
12293 -- Indicate that both the original entity and its renaming are
12294 -- referenced at this point.
12296 Generate_Reference (Entity (N), N);
12297 Generate_Reference (Op, N);
12300 Set_Left_Opnd (Op_Node, Left_Opnd (N));
12303 Rewrite (N, Op_Node);
12305 -- If the context type is private, add the appropriate conversions so
12306 -- that the operator is applied to the full view. This is done in the
12307 -- routines that resolve intrinsic operators.
12309 if Is_Intrinsic_Subprogram (Op) and then Is_Private_Type (Typ) then
12319 Resolve_Intrinsic_Operator (N, Typ);
12325 Resolve_Intrinsic_Unary_Operator (N, Typ);
12332 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
12334 -- Operator renames a user-defined operator of the same name. Use the
12335 -- original operator in the node, which is the one Gigi knows about.
12337 Set_Entity (N, Op);
12338 Set_Is_Overloaded (N, False);
12340 end Rewrite_Renamed_Operator;
12342 -----------------------
12343 -- Set_Slice_Subtype --
12344 -----------------------
12346 -- Build an implicit subtype declaration to represent the type delivered by
12347 -- the slice. This is an abbreviated version of an array subtype. We define
12348 -- an index subtype for the slice, using either the subtype name or the
12349 -- discrete range of the slice. To be consistent with index usage elsewhere
12350 -- we create a list header to hold the single index. This list is not
12351 -- otherwise attached to the syntax tree.
12353 procedure Set_Slice_Subtype (N : Node_Id) is
12354 Loc : constant Source_Ptr := Sloc (N);
12355 Index_List : constant List_Id := New_List;
12357 Index_Subtype : Entity_Id;
12358 Index_Type : Entity_Id;
12359 Slice_Subtype : Entity_Id;
12360 Drange : constant Node_Id := Discrete_Range (N);
12363 Index_Type := Base_Type (Etype (Drange));
12365 if Is_Entity_Name (Drange) then
12366 Index_Subtype := Entity (Drange);
12369 -- We force the evaluation of a range. This is definitely needed in
12370 -- the renamed case, and seems safer to do unconditionally. Note in
12371 -- any case that since we will create and insert an Itype referring
12372 -- to this range, we must make sure any side effect removal actions
12373 -- are inserted before the Itype definition.
12375 if Nkind (Drange) = N_Range then
12376 Force_Evaluation (Low_Bound (Drange));
12377 Force_Evaluation (High_Bound (Drange));
12379 -- If the discrete range is given by a subtype indication, the
12380 -- type of the slice is the base of the subtype mark.
12382 elsif Nkind (Drange) = N_Subtype_Indication then
12384 R : constant Node_Id := Range_Expression (Constraint (Drange));
12386 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
12387 Force_Evaluation (Low_Bound (R));
12388 Force_Evaluation (High_Bound (R));
12392 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
12394 -- Take a new copy of Drange (where bounds have been rewritten to
12395 -- reference side-effect-free names). Using a separate tree ensures
12396 -- that further expansion (e.g. while rewriting a slice assignment
12397 -- into a FOR loop) does not attempt to remove side effects on the
12398 -- bounds again (which would cause the bounds in the index subtype
12399 -- definition to refer to temporaries before they are defined) (the
12400 -- reason is that some names are considered side effect free here
12401 -- for the subtype, but not in the context of a loop iteration
12404 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
12405 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
12406 Set_Etype (Index_Subtype, Index_Type);
12407 Set_Size_Info (Index_Subtype, Index_Type);
12408 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
12409 Set_Is_Constrained (Index_Subtype);
12412 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
12414 Index := New_Occurrence_Of (Index_Subtype, Loc);
12415 Set_Etype (Index, Index_Subtype);
12416 Append (Index, Index_List);
12418 Set_First_Index (Slice_Subtype, Index);
12419 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
12420 Set_Is_Constrained (Slice_Subtype, True);
12422 Check_Compile_Time_Size (Slice_Subtype);
12424 -- The Etype of the existing Slice node is reset to this slice subtype.
12425 -- Its bounds are obtained from its first index.
12427 Set_Etype (N, Slice_Subtype);
12429 -- For bit-packed slice subtypes, freeze immediately (except in the case
12430 -- of being in a "spec expression" where we never freeze when we first
12431 -- see the expression).
12433 if Is_Bit_Packed_Array (Slice_Subtype) and not In_Spec_Expression then
12434 Freeze_Itype (Slice_Subtype, N);
12436 -- For all other cases insert an itype reference in the slice's actions
12437 -- so that the itype is frozen at the proper place in the tree (i.e. at
12438 -- the point where actions for the slice are analyzed). Note that this
12439 -- is different from freezing the itype immediately, which might be
12440 -- premature (e.g. if the slice is within a transient scope). This needs
12441 -- to be done only if expansion is enabled.
12443 elsif Expander_Active then
12444 Ensure_Defined (Typ => Slice_Subtype, N => N);
12446 end Set_Slice_Subtype;
12448 --------------------------------
12449 -- Set_String_Literal_Subtype --
12450 --------------------------------
12452 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
12453 Loc : constant Source_Ptr := Sloc (N);
12454 Low_Bound : constant Node_Id :=
12455 Type_Low_Bound (Etype (First_Index (Typ)));
12456 Subtype_Id : Entity_Id;
12459 if Nkind (N) /= N_String_Literal then
12463 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
12464 Set_String_Literal_Length (Subtype_Id, UI_From_Int
12465 (String_Length (Strval (N))));
12466 Set_Etype (Subtype_Id, Base_Type (Typ));
12467 Set_Is_Constrained (Subtype_Id);
12468 Set_Etype (N, Subtype_Id);
12470 -- The low bound is set from the low bound of the corresponding index
12471 -- type. Note that we do not store the high bound in the string literal
12472 -- subtype, but it can be deduced if necessary from the length and the
12475 if Is_OK_Static_Expression (Low_Bound) then
12476 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
12478 -- If the lower bound is not static we create a range for the string
12479 -- literal, using the index type and the known length of the literal.
12480 -- The index type is not necessarily Positive, so the upper bound is
12481 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
12485 Index_List : constant List_Id := New_List;
12486 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
12487 High_Bound : constant Node_Id :=
12488 Make_Attribute_Reference (Loc,
12489 Attribute_Name => Name_Val,
12491 New_Occurrence_Of (Index_Type, Loc),
12492 Expressions => New_List (
12495 Make_Attribute_Reference (Loc,
12496 Attribute_Name => Name_Pos,
12498 New_Occurrence_Of (Index_Type, Loc),
12500 New_List (New_Copy_Tree (Low_Bound))),
12502 Make_Integer_Literal (Loc,
12503 String_Length (Strval (N)) - 1))));
12505 Array_Subtype : Entity_Id;
12508 Index_Subtype : Entity_Id;
12511 if Is_Integer_Type (Index_Type) then
12512 Set_String_Literal_Low_Bound
12513 (Subtype_Id, Make_Integer_Literal (Loc, 1));
12516 -- If the index type is an enumeration type, build bounds
12517 -- expression with attributes.
12519 Set_String_Literal_Low_Bound
12521 Make_Attribute_Reference (Loc,
12522 Attribute_Name => Name_First,
12524 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
12525 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
12528 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
12530 -- Build bona fide subtype for the string, and wrap it in an
12531 -- unchecked conversion, because the back end expects the
12532 -- String_Literal_Subtype to have a static lower bound.
12535 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
12536 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
12537 Set_Scalar_Range (Index_Subtype, Drange);
12538 Set_Parent (Drange, N);
12539 Analyze_And_Resolve (Drange, Index_Type);
12541 -- In this context, the Index_Type may already have a constraint,
12542 -- so use common base type on string subtype. The base type may
12543 -- be used when generating attributes of the string, for example
12544 -- in the context of a slice assignment.
12546 Set_Etype (Index_Subtype, Base_Type (Index_Type));
12547 Set_Size_Info (Index_Subtype, Index_Type);
12548 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
12550 Array_Subtype := Create_Itype (E_Array_Subtype, N);
12552 Index := New_Occurrence_Of (Index_Subtype, Loc);
12553 Set_Etype (Index, Index_Subtype);
12554 Append (Index, Index_List);
12556 Set_First_Index (Array_Subtype, Index);
12557 Set_Etype (Array_Subtype, Base_Type (Typ));
12558 Set_Is_Constrained (Array_Subtype, True);
12561 Make_Unchecked_Type_Conversion (Loc,
12562 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
12563 Expression => Relocate_Node (N)));
12564 Set_Etype (N, Array_Subtype);
12567 end Set_String_Literal_Subtype;
12569 ------------------------------
12570 -- Simplify_Type_Conversion --
12571 ------------------------------
12573 procedure Simplify_Type_Conversion (N : Node_Id) is
12575 if Nkind (N) = N_Type_Conversion then
12577 Operand : constant Node_Id := Expression (N);
12578 Target_Typ : constant Entity_Id := Etype (N);
12579 Opnd_Typ : constant Entity_Id := Etype (Operand);
12582 -- Special processing if the conversion is the expression of a
12583 -- Rounding or Truncation attribute reference. In this case we
12586 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
12592 -- with the Float_Truncate flag set to False or True respectively,
12593 -- which is more efficient. We reuse Rounding for Machine_Rounding
12594 -- as System.Fat_Gen, which is a permissible behavior.
12596 if Is_Floating_Point_Type (Opnd_Typ)
12598 (Is_Integer_Type (Target_Typ)
12599 or else (Is_Fixed_Point_Type (Target_Typ)
12600 and then Conversion_OK (N)))
12601 and then Nkind (Operand) = N_Attribute_Reference
12602 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
12603 Name_Machine_Rounding,
12607 Truncate : constant Boolean :=
12608 Attribute_Name (Operand) = Name_Truncation;
12611 Relocate_Node (First (Expressions (Operand))));
12612 Set_Float_Truncate (N, Truncate);
12617 end Simplify_Type_Conversion;
12619 -----------------------------
12620 -- Unique_Fixed_Point_Type --
12621 -----------------------------
12623 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
12624 procedure Fixed_Point_Error (T1 : Entity_Id; T2 : Entity_Id);
12625 -- Give error messages for true ambiguity. Messages are posted on node
12626 -- N, and entities T1, T2 are the possible interpretations.
12628 -----------------------
12629 -- Fixed_Point_Error --
12630 -----------------------
12632 procedure Fixed_Point_Error (T1 : Entity_Id; T2 : Entity_Id) is
12634 Error_Msg_N ("ambiguous universal_fixed_expression", N);
12635 Error_Msg_NE ("\\possible interpretation as}", N, T1);
12636 Error_Msg_NE ("\\possible interpretation as}", N, T2);
12637 end Fixed_Point_Error;
12647 -- Start of processing for Unique_Fixed_Point_Type
12650 -- The operations on Duration are visible, so Duration is always a
12651 -- possible interpretation.
12653 T1 := Standard_Duration;
12655 -- Look for fixed-point types in enclosing scopes
12657 Scop := Current_Scope;
12658 while Scop /= Standard_Standard loop
12659 T2 := First_Entity (Scop);
12660 while Present (T2) loop
12661 if Is_Fixed_Point_Type (T2)
12662 and then Current_Entity (T2) = T2
12663 and then Scope (Base_Type (T2)) = Scop
12665 if Present (T1) then
12666 Fixed_Point_Error (T1, T2);
12676 Scop := Scope (Scop);
12679 -- Look for visible fixed type declarations in the context
12681 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
12682 while Present (Item) loop
12683 if Nkind (Item) = N_With_Clause then
12684 Scop := Entity (Name (Item));
12685 T2 := First_Entity (Scop);
12686 while Present (T2) loop
12687 if Is_Fixed_Point_Type (T2)
12688 and then Scope (Base_Type (T2)) = Scop
12689 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
12691 if Present (T1) then
12692 Fixed_Point_Error (T1, T2);
12706 if Nkind (N) = N_Real_Literal then
12707 Error_Msg_NE ("??real literal interpreted as }!", N, T1);
12710 -- When the context is a type conversion, issue the warning on the
12711 -- expression of the conversion because it is the actual operation.
12713 if Nkind_In (N, N_Type_Conversion, N_Unchecked_Type_Conversion) then
12714 ErrN := Expression (N);
12720 ("??universal_fixed expression interpreted as }!", ErrN, T1);
12724 end Unique_Fixed_Point_Type;
12726 ----------------------
12727 -- Valid_Conversion --
12728 ----------------------
12730 function Valid_Conversion
12732 Target : Entity_Id;
12734 Report_Errs : Boolean := True) return Boolean
12736 Target_Type : constant Entity_Id := Base_Type (Target);
12737 Opnd_Type : Entity_Id := Etype (Operand);
12738 Inc_Ancestor : Entity_Id;
12740 function Conversion_Check
12742 Msg : String) return Boolean;
12743 -- Little routine to post Msg if Valid is False, returns Valid value
12745 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
12746 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
12748 procedure Conversion_Error_NE
12750 N : Node_Or_Entity_Id;
12751 E : Node_Or_Entity_Id);
12752 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
12754 function In_Instance_Code return Boolean;
12755 -- Return True if expression is within an instance but is not in one of
12756 -- the actuals of the instantiation. Type conversions within an instance
12757 -- are not rechecked because type visbility may lead to spurious errors,
12758 -- but conversions in an actual for a formal object must be checked.
12760 function Valid_Tagged_Conversion
12761 (Target_Type : Entity_Id;
12762 Opnd_Type : Entity_Id) return Boolean;
12763 -- Specifically test for validity of tagged conversions
12765 function Valid_Array_Conversion return Boolean;
12766 -- Check index and component conformance, and accessibility levels if
12767 -- the component types are anonymous access types (Ada 2005).
12769 ----------------------
12770 -- Conversion_Check --
12771 ----------------------
12773 function Conversion_Check
12775 Msg : String) return Boolean
12780 -- A generic unit has already been analyzed and we have verified
12781 -- that a particular conversion is OK in that context. Since the
12782 -- instance is reanalyzed without relying on the relationships
12783 -- established during the analysis of the generic, it is possible
12784 -- to end up with inconsistent views of private types. Do not emit
12785 -- the error message in such cases. The rest of the machinery in
12786 -- Valid_Conversion still ensures the proper compatibility of
12787 -- target and operand types.
12789 and then not In_Instance_Code
12791 Conversion_Error_N (Msg, Operand);
12795 end Conversion_Check;
12797 ------------------------
12798 -- Conversion_Error_N --
12799 ------------------------
12801 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
12803 if Report_Errs then
12804 Error_Msg_N (Msg, N);
12806 end Conversion_Error_N;
12808 -------------------------
12809 -- Conversion_Error_NE --
12810 -------------------------
12812 procedure Conversion_Error_NE
12814 N : Node_Or_Entity_Id;
12815 E : Node_Or_Entity_Id)
12818 if Report_Errs then
12819 Error_Msg_NE (Msg, N, E);
12821 end Conversion_Error_NE;
12823 ----------------------
12824 -- In_Instance_Code --
12825 ----------------------
12827 function In_Instance_Code return Boolean is
12831 if not In_Instance then
12836 while Present (Par) loop
12838 -- The expression is part of an actual object if it appears in
12839 -- the generated object declaration in the instance.
12841 if Nkind (Par) = N_Object_Declaration
12842 and then Present (Corresponding_Generic_Association (Par))
12848 Nkind (Par) in N_Statement_Other_Than_Procedure_Call
12849 or else Nkind (Par) in N_Subprogram_Call
12850 or else Nkind (Par) in N_Declaration;
12853 Par := Parent (Par);
12856 -- Otherwise the expression appears within the instantiated unit
12860 end In_Instance_Code;
12862 ----------------------------
12863 -- Valid_Array_Conversion --
12864 ----------------------------
12866 function Valid_Array_Conversion return Boolean is
12867 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
12868 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
12870 Opnd_Index : Node_Id;
12871 Opnd_Index_Type : Entity_Id;
12873 Target_Comp_Type : constant Entity_Id :=
12874 Component_Type (Target_Type);
12875 Target_Comp_Base : constant Entity_Id :=
12876 Base_Type (Target_Comp_Type);
12878 Target_Index : Node_Id;
12879 Target_Index_Type : Entity_Id;
12882 -- Error if wrong number of dimensions
12885 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
12888 ("incompatible number of dimensions for conversion", Operand);
12891 -- Number of dimensions matches
12894 -- Loop through indexes of the two arrays
12896 Target_Index := First_Index (Target_Type);
12897 Opnd_Index := First_Index (Opnd_Type);
12898 while Present (Target_Index) and then Present (Opnd_Index) loop
12899 Target_Index_Type := Etype (Target_Index);
12900 Opnd_Index_Type := Etype (Opnd_Index);
12902 -- Error if index types are incompatible
12904 if not (Is_Integer_Type (Target_Index_Type)
12905 and then Is_Integer_Type (Opnd_Index_Type))
12906 and then (Root_Type (Target_Index_Type)
12907 /= Root_Type (Opnd_Index_Type))
12910 ("incompatible index types for array conversion",
12915 Next_Index (Target_Index);
12916 Next_Index (Opnd_Index);
12919 -- If component types have same base type, all set
12921 if Target_Comp_Base = Opnd_Comp_Base then
12924 -- Here if base types of components are not the same. The only
12925 -- time this is allowed is if we have anonymous access types.
12927 -- The conversion of arrays of anonymous access types can lead
12928 -- to dangling pointers. AI-392 formalizes the accessibility
12929 -- checks that must be applied to such conversions to prevent
12930 -- out-of-scope references.
12933 (Target_Comp_Base, E_Anonymous_Access_Type,
12934 E_Anonymous_Access_Subprogram_Type)
12935 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
12937 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
12939 if Type_Access_Level (Target_Type) <
12940 Deepest_Type_Access_Level (Opnd_Type)
12942 if In_Instance_Body then
12943 Error_Msg_Warn := SPARK_Mode /= On;
12945 ("source array type has deeper accessibility "
12946 & "level than target<<", Operand);
12947 Conversion_Error_N ("\Program_Error [<<", Operand);
12949 Make_Raise_Program_Error (Sloc (N),
12950 Reason => PE_Accessibility_Check_Failed));
12951 Set_Etype (N, Target_Type);
12954 -- Conversion not allowed because of accessibility levels
12958 ("source array type has deeper accessibility "
12959 & "level than target", Operand);
12967 -- All other cases where component base types do not match
12971 ("incompatible component types for array conversion",
12976 -- Check that component subtypes statically match. For numeric
12977 -- types this means that both must be either constrained or
12978 -- unconstrained. For enumeration types the bounds must match.
12979 -- All of this is checked in Subtypes_Statically_Match.
12981 if not Subtypes_Statically_Match
12982 (Target_Comp_Type, Opnd_Comp_Type)
12985 ("component subtypes must statically match", Operand);
12991 end Valid_Array_Conversion;
12993 -----------------------------
12994 -- Valid_Tagged_Conversion --
12995 -----------------------------
12997 function Valid_Tagged_Conversion
12998 (Target_Type : Entity_Id;
12999 Opnd_Type : Entity_Id) return Boolean
13002 -- Upward conversions are allowed (RM 4.6(22))
13004 if Covers (Target_Type, Opnd_Type)
13005 or else Is_Ancestor (Target_Type, Opnd_Type)
13009 -- Downward conversion are allowed if the operand is class-wide
13012 elsif Is_Class_Wide_Type (Opnd_Type)
13013 and then Covers (Opnd_Type, Target_Type)
13017 elsif Covers (Opnd_Type, Target_Type)
13018 or else Is_Ancestor (Opnd_Type, Target_Type)
13021 Conversion_Check (False,
13022 "downward conversion of tagged objects not allowed");
13024 -- Ada 2005 (AI-251): The conversion to/from interface types is
13025 -- always valid. The types involved may be class-wide (sub)types.
13027 elsif Is_Interface (Etype (Base_Type (Target_Type)))
13028 or else Is_Interface (Etype (Base_Type (Opnd_Type)))
13032 -- If the operand is a class-wide type obtained through a limited_
13033 -- with clause, and the context includes the nonlimited view, use
13034 -- it to determine whether the conversion is legal.
13036 elsif Is_Class_Wide_Type (Opnd_Type)
13037 and then From_Limited_With (Opnd_Type)
13038 and then Present (Non_Limited_View (Etype (Opnd_Type)))
13039 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
13043 elsif Is_Access_Type (Opnd_Type)
13044 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
13049 Conversion_Error_NE
13050 ("invalid tagged conversion, not compatible with}",
13051 N, First_Subtype (Opnd_Type));
13054 end Valid_Tagged_Conversion;
13056 -- Start of processing for Valid_Conversion
13059 Check_Parameterless_Call (Operand);
13061 if Is_Overloaded (Operand) then
13071 -- Remove procedure calls, which syntactically cannot appear in
13072 -- this context, but which cannot be removed by type checking,
13073 -- because the context does not impose a type.
13075 -- The node may be labelled overloaded, but still contain only one
13076 -- interpretation because others were discarded earlier. If this
13077 -- is the case, retain the single interpretation if legal.
13079 Get_First_Interp (Operand, I, It);
13080 Opnd_Type := It.Typ;
13081 Get_Next_Interp (I, It);
13083 if Present (It.Typ)
13084 and then Opnd_Type /= Standard_Void_Type
13086 -- More than one candidate interpretation is available
13088 Get_First_Interp (Operand, I, It);
13089 while Present (It.Typ) loop
13090 if It.Typ = Standard_Void_Type then
13094 -- When compiling for a system where Address is of a visible
13095 -- integer type, spurious ambiguities can be produced when
13096 -- arithmetic operations have a literal operand and return
13097 -- System.Address or a descendant of it. These ambiguities
13098 -- are usually resolved by the context, but for conversions
13099 -- there is no context type and the removal of the spurious
13100 -- operations must be done explicitly here.
13102 if not Address_Is_Private
13103 and then Is_Descendant_Of_Address (It.Typ)
13108 Get_Next_Interp (I, It);
13112 Get_First_Interp (Operand, I, It);
13116 if No (It.Typ) then
13117 Conversion_Error_N ("illegal operand in conversion", Operand);
13121 Get_Next_Interp (I, It);
13123 if Present (It.Typ) then
13126 It1 := Disambiguate (Operand, I1, I, Any_Type);
13128 if It1 = No_Interp then
13130 ("ambiguous operand in conversion", Operand);
13132 -- If the interpretation involves a standard operator, use
13133 -- the location of the type, which may be user-defined.
13135 if Sloc (It.Nam) = Standard_Location then
13136 Error_Msg_Sloc := Sloc (It.Typ);
13138 Error_Msg_Sloc := Sloc (It.Nam);
13141 Conversion_Error_N -- CODEFIX
13142 ("\\possible interpretation#!", Operand);
13144 if Sloc (N1) = Standard_Location then
13145 Error_Msg_Sloc := Sloc (T1);
13147 Error_Msg_Sloc := Sloc (N1);
13150 Conversion_Error_N -- CODEFIX
13151 ("\\possible interpretation#!", Operand);
13157 Set_Etype (Operand, It1.Typ);
13158 Opnd_Type := It1.Typ;
13162 -- Deal with conversion of integer type to address if the pragma
13163 -- Allow_Integer_Address is in effect. We convert the conversion to
13164 -- an unchecked conversion in this case and we are all done.
13166 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
13167 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
13168 Analyze_And_Resolve (N, Target_Type);
13172 -- If we are within a child unit, check whether the type of the
13173 -- expression has an ancestor in a parent unit, in which case it
13174 -- belongs to its derivation class even if the ancestor is private.
13175 -- See RM 7.3.1 (5.2/3).
13177 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
13181 if Is_Numeric_Type (Target_Type) then
13183 -- A universal fixed expression can be converted to any numeric type
13185 if Opnd_Type = Universal_Fixed then
13188 -- Also no need to check when in an instance or inlined body, because
13189 -- the legality has been established when the template was analyzed.
13190 -- Furthermore, numeric conversions may occur where only a private
13191 -- view of the operand type is visible at the instantiation point.
13192 -- This results in a spurious error if we check that the operand type
13193 -- is a numeric type.
13195 -- Note: in a previous version of this unit, the following tests were
13196 -- applied only for generated code (Comes_From_Source set to False),
13197 -- but in fact the test is required for source code as well, since
13198 -- this situation can arise in source code.
13200 elsif In_Instance_Code or else In_Inlined_Body then
13203 -- Otherwise we need the conversion check
13206 return Conversion_Check
13207 (Is_Numeric_Type (Opnd_Type)
13209 (Present (Inc_Ancestor)
13210 and then Is_Numeric_Type (Inc_Ancestor)),
13211 "illegal operand for numeric conversion");
13216 elsif Is_Array_Type (Target_Type) then
13217 if not Is_Array_Type (Opnd_Type)
13218 or else Opnd_Type = Any_Composite
13219 or else Opnd_Type = Any_String
13222 ("illegal operand for array conversion", Operand);
13226 return Valid_Array_Conversion;
13229 -- Ada 2005 (AI-251): Internally generated conversions of access to
13230 -- interface types added to force the displacement of the pointer to
13231 -- reference the corresponding dispatch table.
13233 elsif not Comes_From_Source (N)
13234 and then Is_Access_Type (Target_Type)
13235 and then Is_Interface (Designated_Type (Target_Type))
13239 -- Ada 2005 (AI-251): Anonymous access types where target references an
13242 elsif Is_Access_Type (Opnd_Type)
13243 and then Ekind_In (Target_Type, E_General_Access_Type,
13244 E_Anonymous_Access_Type)
13245 and then Is_Interface (Directly_Designated_Type (Target_Type))
13247 -- Check the static accessibility rule of 4.6(17). Note that the
13248 -- check is not enforced when within an instance body, since the
13249 -- RM requires such cases to be caught at run time.
13251 -- If the operand is a rewriting of an allocator no check is needed
13252 -- because there are no accessibility issues.
13254 if Nkind (Original_Node (N)) = N_Allocator then
13257 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
13258 if Type_Access_Level (Opnd_Type) >
13259 Deepest_Type_Access_Level (Target_Type)
13261 -- In an instance, this is a run-time check, but one we know
13262 -- will fail, so generate an appropriate warning. The raise
13263 -- will be generated by Expand_N_Type_Conversion.
13265 if In_Instance_Body then
13266 Error_Msg_Warn := SPARK_Mode /= On;
13268 ("cannot convert local pointer to non-local access type<<",
13270 Conversion_Error_N ("\Program_Error [<<", Operand);
13274 ("cannot convert local pointer to non-local access type",
13279 -- Special accessibility checks are needed in the case of access
13280 -- discriminants declared for a limited type.
13282 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
13283 and then not Is_Local_Anonymous_Access (Opnd_Type)
13285 -- When the operand is a selected access discriminant the check
13286 -- needs to be made against the level of the object denoted by
13287 -- the prefix of the selected name (Object_Access_Level handles
13288 -- checking the prefix of the operand for this case).
13290 if Nkind (Operand) = N_Selected_Component
13291 and then Object_Access_Level (Operand) >
13292 Deepest_Type_Access_Level (Target_Type)
13294 -- In an instance, this is a run-time check, but one we know
13295 -- will fail, so generate an appropriate warning. The raise
13296 -- will be generated by Expand_N_Type_Conversion.
13298 if In_Instance_Body then
13299 Error_Msg_Warn := SPARK_Mode /= On;
13301 ("cannot convert access discriminant to non-local "
13302 & "access type<<", Operand);
13303 Conversion_Error_N ("\Program_Error [<<", Operand);
13305 -- Real error if not in instance body
13309 ("cannot convert access discriminant to non-local "
13310 & "access type", Operand);
13315 -- The case of a reference to an access discriminant from
13316 -- within a limited type declaration (which will appear as
13317 -- a discriminal) is always illegal because the level of the
13318 -- discriminant is considered to be deeper than any (nameable)
13321 if Is_Entity_Name (Operand)
13322 and then not Is_Local_Anonymous_Access (Opnd_Type)
13324 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
13325 and then Present (Discriminal_Link (Entity (Operand)))
13328 ("discriminant has deeper accessibility level than target",
13337 -- General and anonymous access types
13339 elsif Ekind_In (Target_Type, E_General_Access_Type,
13340 E_Anonymous_Access_Type)
13343 (Is_Access_Type (Opnd_Type)
13345 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
13346 E_Access_Protected_Subprogram_Type),
13347 "must be an access-to-object type")
13349 if Is_Access_Constant (Opnd_Type)
13350 and then not Is_Access_Constant (Target_Type)
13353 ("access-to-constant operand type not allowed", Operand);
13357 -- Check the static accessibility rule of 4.6(17). Note that the
13358 -- check is not enforced when within an instance body, since the RM
13359 -- requires such cases to be caught at run time.
13361 if Ekind (Target_Type) /= E_Anonymous_Access_Type
13362 or else Is_Local_Anonymous_Access (Target_Type)
13363 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
13364 N_Object_Declaration
13366 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
13367 -- conversions from an anonymous access type to a named general
13368 -- access type. Such conversions are not allowed in the case of
13369 -- access parameters and stand-alone objects of an anonymous
13370 -- access type. The implicit conversion case is recognized by
13371 -- testing that Comes_From_Source is False and that it's been
13372 -- rewritten. The Comes_From_Source test isn't sufficient because
13373 -- nodes in inlined calls to predefined library routines can have
13374 -- Comes_From_Source set to False. (Is there a better way to test
13375 -- for implicit conversions???)
13377 if Ada_Version >= Ada_2012
13378 and then not Comes_From_Source (N)
13379 and then Is_Rewrite_Substitution (N)
13380 and then Ekind (Base_Type (Target_Type)) = E_General_Access_Type
13381 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
13383 if Is_Itype (Opnd_Type) then
13385 -- Implicit conversions aren't allowed for objects of an
13386 -- anonymous access type, since such objects have nonstatic
13387 -- levels in Ada 2012.
13389 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
13390 N_Object_Declaration
13393 ("implicit conversion of stand-alone anonymous "
13394 & "access object not allowed", Operand);
13397 -- Implicit conversions aren't allowed for anonymous access
13398 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
13399 -- is done to exclude anonymous access results.
13401 elsif not Is_Local_Anonymous_Access (Opnd_Type)
13402 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
13403 N_Function_Specification,
13404 N_Procedure_Specification)
13407 ("implicit conversion of anonymous access formal "
13408 & "not allowed", Operand);
13411 -- This is a case where there's an enclosing object whose
13412 -- to which the "statically deeper than" relationship does
13413 -- not apply (such as an access discriminant selected from
13414 -- a dereference of an access parameter).
13416 elsif Object_Access_Level (Operand)
13417 = Scope_Depth (Standard_Standard)
13420 ("implicit conversion of anonymous access value "
13421 & "not allowed", Operand);
13424 -- In other cases, the level of the operand's type must be
13425 -- statically less deep than that of the target type, else
13426 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
13428 elsif Type_Access_Level (Opnd_Type) >
13429 Deepest_Type_Access_Level (Target_Type)
13432 ("implicit conversion of anonymous access value "
13433 & "violates accessibility", Operand);
13438 elsif Type_Access_Level (Opnd_Type) >
13439 Deepest_Type_Access_Level (Target_Type)
13441 -- In an instance, this is a run-time check, but one we know
13442 -- will fail, so generate an appropriate warning. The raise
13443 -- will be generated by Expand_N_Type_Conversion.
13445 if In_Instance_Body then
13446 Error_Msg_Warn := SPARK_Mode /= On;
13448 ("cannot convert local pointer to non-local access type<<",
13450 Conversion_Error_N ("\Program_Error [<<", Operand);
13452 -- If not in an instance body, this is a real error
13455 -- Avoid generation of spurious error message
13457 if not Error_Posted (N) then
13459 ("cannot convert local pointer to non-local access type",
13466 -- Special accessibility checks are needed in the case of access
13467 -- discriminants declared for a limited type.
13469 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
13470 and then not Is_Local_Anonymous_Access (Opnd_Type)
13472 -- When the operand is a selected access discriminant the check
13473 -- needs to be made against the level of the object denoted by
13474 -- the prefix of the selected name (Object_Access_Level handles
13475 -- checking the prefix of the operand for this case).
13477 if Nkind (Operand) = N_Selected_Component
13478 and then Object_Access_Level (Operand) >
13479 Deepest_Type_Access_Level (Target_Type)
13481 -- In an instance, this is a run-time check, but one we know
13482 -- will fail, so generate an appropriate warning. The raise
13483 -- will be generated by Expand_N_Type_Conversion.
13485 if In_Instance_Body then
13486 Error_Msg_Warn := SPARK_Mode /= On;
13488 ("cannot convert access discriminant to non-local "
13489 & "access type<<", Operand);
13490 Conversion_Error_N ("\Program_Error [<<", Operand);
13492 -- If not in an instance body, this is a real error
13496 ("cannot convert access discriminant to non-local "
13497 & "access type", Operand);
13502 -- The case of a reference to an access discriminant from
13503 -- within a limited type declaration (which will appear as
13504 -- a discriminal) is always illegal because the level of the
13505 -- discriminant is considered to be deeper than any (nameable)
13508 if Is_Entity_Name (Operand)
13510 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
13511 and then Present (Discriminal_Link (Entity (Operand)))
13514 ("discriminant has deeper accessibility level than target",
13521 -- In the presence of limited_with clauses we have to use nonlimited
13522 -- views, if available.
13524 Check_Limited : declare
13525 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
13526 -- Helper function to handle limited views
13528 --------------------------
13529 -- Full_Designated_Type --
13530 --------------------------
13532 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
13533 Desig : constant Entity_Id := Designated_Type (T);
13536 -- Handle the limited view of a type
13538 if From_Limited_With (Desig)
13539 and then Has_Non_Limited_View (Desig)
13541 return Available_View (Desig);
13545 end Full_Designated_Type;
13547 -- Local Declarations
13549 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
13550 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
13552 Same_Base : constant Boolean :=
13553 Base_Type (Target) = Base_Type (Opnd);
13555 -- Start of processing for Check_Limited
13558 if Is_Tagged_Type (Target) then
13559 return Valid_Tagged_Conversion (Target, Opnd);
13562 if not Same_Base then
13563 Conversion_Error_NE
13564 ("target designated type not compatible with }",
13565 N, Base_Type (Opnd));
13568 -- Ada 2005 AI-384: legality rule is symmetric in both
13569 -- designated types. The conversion is legal (with possible
13570 -- constraint check) if either designated type is
13573 elsif Subtypes_Statically_Match (Target, Opnd)
13575 (Has_Discriminants (Target)
13577 (not Is_Constrained (Opnd)
13578 or else not Is_Constrained (Target)))
13580 -- Special case, if Value_Size has been used to make the
13581 -- sizes different, the conversion is not allowed even
13582 -- though the subtypes statically match.
13584 if Known_Static_RM_Size (Target)
13585 and then Known_Static_RM_Size (Opnd)
13586 and then RM_Size (Target) /= RM_Size (Opnd)
13588 Conversion_Error_NE
13589 ("target designated subtype not compatible with }",
13591 Conversion_Error_NE
13592 ("\because sizes of the two designated subtypes differ",
13596 -- Normal case where conversion is allowed
13604 ("target designated subtype not compatible with }",
13611 -- Access to subprogram types. If the operand is an access parameter,
13612 -- the type has a deeper accessibility that any master, and cannot be
13613 -- assigned. We must make an exception if the conversion is part of an
13614 -- assignment and the target is the return object of an extended return
13615 -- statement, because in that case the accessibility check takes place
13616 -- after the return.
13618 elsif Is_Access_Subprogram_Type (Target_Type)
13620 -- Note: this test of Opnd_Type is there to prevent entering this
13621 -- branch in the case of a remote access to subprogram type, which
13622 -- is internally represented as an E_Record_Type.
13624 and then Is_Access_Type (Opnd_Type)
13626 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
13627 and then Is_Entity_Name (Operand)
13628 and then Ekind (Entity (Operand)) = E_In_Parameter
13630 (Nkind (Parent (N)) /= N_Assignment_Statement
13631 or else not Is_Entity_Name (Name (Parent (N)))
13632 or else not Is_Return_Object (Entity (Name (Parent (N)))))
13635 ("illegal attempt to store anonymous access to subprogram",
13638 ("\value has deeper accessibility than any master "
13639 & "(RM 3.10.2 (13))",
13643 ("\use named access type for& instead of access parameter",
13644 Operand, Entity (Operand));
13647 -- Check that the designated types are subtype conformant
13649 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
13650 Old_Id => Designated_Type (Opnd_Type),
13653 -- Check the static accessibility rule of 4.6(20)
13655 if Type_Access_Level (Opnd_Type) >
13656 Deepest_Type_Access_Level (Target_Type)
13659 ("operand type has deeper accessibility level than target",
13662 -- Check that if the operand type is declared in a generic body,
13663 -- then the target type must be declared within that same body
13664 -- (enforces last sentence of 4.6(20)).
13666 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
13668 O_Gen : constant Node_Id :=
13669 Enclosing_Generic_Body (Opnd_Type);
13674 T_Gen := Enclosing_Generic_Body (Target_Type);
13675 while Present (T_Gen) and then T_Gen /= O_Gen loop
13676 T_Gen := Enclosing_Generic_Body (T_Gen);
13679 if T_Gen /= O_Gen then
13681 ("target type must be declared in same generic body "
13682 & "as operand type", N);
13689 -- Remote access to subprogram types
13691 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
13692 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
13694 -- It is valid to convert from one RAS type to another provided
13695 -- that their specification statically match.
13697 -- Note: at this point, remote access to subprogram types have been
13698 -- expanded to their E_Record_Type representation, and we need to
13699 -- go back to the original access type definition using the
13700 -- Corresponding_Remote_Type attribute in order to check that the
13701 -- designated profiles match.
13703 pragma Assert (Ekind (Target_Type) = E_Record_Type);
13704 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
13706 Check_Subtype_Conformant
13708 Designated_Type (Corresponding_Remote_Type (Target_Type)),
13710 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
13715 -- If it was legal in the generic, it's legal in the instance
13717 elsif In_Instance_Body then
13720 -- If both are tagged types, check legality of view conversions
13722 elsif Is_Tagged_Type (Target_Type)
13724 Is_Tagged_Type (Opnd_Type)
13726 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
13728 -- Types derived from the same root type are convertible
13730 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
13733 -- In an instance or an inlined body, there may be inconsistent views of
13734 -- the same type, or of types derived from a common root.
13736 elsif (In_Instance or In_Inlined_Body)
13738 Root_Type (Underlying_Type (Target_Type)) =
13739 Root_Type (Underlying_Type (Opnd_Type))
13743 -- Special check for common access type error case
13745 elsif Ekind (Target_Type) = E_Access_Type
13746 and then Is_Access_Type (Opnd_Type)
13748 Conversion_Error_N ("target type must be general access type!", N);
13749 Conversion_Error_NE -- CODEFIX
13750 ("add ALL to }!", N, Target_Type);
13753 -- Here we have a real conversion error
13756 -- Check for missing regular with_clause when only a limited view of
13757 -- target is available.
13759 if From_Limited_With (Opnd_Type) and then In_Package_Body then
13760 Conversion_Error_NE
13761 ("invalid conversion, not compatible with limited view of }",
13763 Conversion_Error_NE
13764 ("\add with_clause for& to current unit!", N, Scope (Opnd_Type));
13766 elsif Is_Access_Type (Opnd_Type)
13767 and then From_Limited_With (Designated_Type (Opnd_Type))
13768 and then In_Package_Body
13770 Conversion_Error_NE
13771 ("invalid conversion, not compatible with }", N, Opnd_Type);
13772 Conversion_Error_NE
13773 ("\add with_clause for& to current unit!",
13774 N, Scope (Designated_Type (Opnd_Type)));
13777 Conversion_Error_NE
13778 ("invalid conversion, not compatible with }", N, Opnd_Type);
13783 end Valid_Conversion;