1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Ghost; use Ghost;
41 with Inline; use Inline;
42 with Itypes; use Itypes;
44 with Lib.Xref; use Lib.Xref;
45 with Namet; use Namet;
46 with Nmake; use Nmake;
47 with Nlists; use Nlists;
49 with Output; use Output;
50 with Par_SCO; use Par_SCO;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Aggr; use Sem_Aggr;
57 with Sem_Attr; use Sem_Attr;
58 with Sem_Cat; use Sem_Cat;
59 with Sem_Ch4; use Sem_Ch4;
60 with Sem_Ch3; use Sem_Ch3;
61 with Sem_Ch6; use Sem_Ch6;
62 with Sem_Ch8; use Sem_Ch8;
63 with Sem_Ch13; use Sem_Ch13;
64 with Sem_Dim; use Sem_Dim;
65 with Sem_Disp; use Sem_Disp;
66 with Sem_Dist; use Sem_Dist;
67 with Sem_Elim; use Sem_Elim;
68 with Sem_Elab; use Sem_Elab;
69 with Sem_Eval; use Sem_Eval;
70 with Sem_Intr; use Sem_Intr;
71 with Sem_Util; use Sem_Util;
72 with Targparm; use Targparm;
73 with Sem_Type; use Sem_Type;
74 with Sem_Warn; use Sem_Warn;
75 with Sinfo; use Sinfo;
76 with Sinfo.CN; use Sinfo.CN;
77 with Snames; use Snames;
78 with Stand; use Stand;
79 with Stringt; use Stringt;
80 with Style; use Style;
81 with Tbuild; use Tbuild;
82 with Uintp; use Uintp;
83 with Urealp; use Urealp;
85 package body Sem_Res is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use (N : Node_Id);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
116 -- Given a call node, N, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
122 -- If the type of the object being initialized uses the secondary stack
123 -- directly or indirectly, create a transient scope for the call to the
124 -- init proc. This is because we do not create transient scopes for the
125 -- initialization of individual components within the init proc itself.
126 -- Could be optimized away perhaps?
128 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
129 -- N is the node for a logical operator. If the operator is predefined, and
130 -- the root type of the operands is Standard.Boolean, then a check is made
131 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
132 -- the style check for Style_Check_Boolean_And_Or.
134 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
135 -- N is either an indexed component or a selected component. This function
136 -- returns true if the prefix refers to an object that has an address
137 -- clause (the case in which we may want to issue a warning).
139 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
211 function Operator_Kind
213 Is_Binary : Boolean) return Node_Kind;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
236 -- Ditto, for arithmetic unary operators
238 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
242 procedure Make_Call_Into_Operator
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so that
248 -- operands are resolved properly. Recall that predefined operators do not
249 -- have a full signature and special resolution rules apply.
251 procedure Rewrite_Renamed_Operator
255 -- An operator can rename another, e.g. in an instantiation. In that
256 -- case, the proper operator node must be constructed and resolved.
258 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
259 -- The String_Literal_Subtype is built for all strings that are not
260 -- operands of a static concatenation operation. If the argument is not
261 -- a N_String_Literal node, then the call has no effect.
263 procedure Set_Slice_Subtype (N : Node_Id);
264 -- Build subtype of array type, with the range specified by the slice
266 procedure Simplify_Type_Conversion (N : Node_Id);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Rounding or Truncation attribute.
271 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
277 -------------------------
278 -- Ambiguous_Character --
279 -------------------------
281 procedure Ambiguous_Character (C : Node_Id) is
285 if Nkind (C) = N_Character_Literal then
286 Error_Msg_N ("ambiguous character literal", C);
288 -- First the ones in Standard
290 Error_Msg_N ("\\possible interpretation: Character!", C);
291 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
293 -- Include Wide_Wide_Character in Ada 2005 mode
295 if Ada_Version >= Ada_2005 then
296 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
299 -- Now any other types that match
301 E := Current_Entity (C);
302 while Present (E) loop
303 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
307 end Ambiguous_Character;
309 -------------------------
310 -- Analyze_And_Resolve --
311 -------------------------
313 procedure Analyze_And_Resolve (N : Node_Id) is
317 end Analyze_And_Resolve;
319 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
323 end Analyze_And_Resolve;
325 -- Versions with check(s) suppressed
327 procedure Analyze_And_Resolve
332 Scop : constant Entity_Id := Current_Scope;
335 if Suppress = All_Checks then
337 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
339 Scope_Suppress.Suppress := (others => True);
340 Analyze_And_Resolve (N, Typ);
341 Scope_Suppress.Suppress := Sva;
346 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
348 Scope_Suppress.Suppress (Suppress) := True;
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress.Suppress (Suppress) := Svg;
354 if Current_Scope /= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
366 end Analyze_And_Resolve;
368 procedure Analyze_And_Resolve
372 Scop : constant Entity_Id := Current_Scope;
375 if Suppress = All_Checks then
377 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
379 Scope_Suppress.Suppress := (others => True);
380 Analyze_And_Resolve (N);
381 Scope_Suppress.Suppress := Sva;
386 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
388 Scope_Suppress.Suppress (Suppress) := True;
389 Analyze_And_Resolve (N);
390 Scope_Suppress.Suppress (Suppress) := Svg;
394 if Current_Scope /= Scop and then Scope_Is_Transient then
395 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
398 end Analyze_And_Resolve;
400 ----------------------------
401 -- Check_Discriminant_Use --
402 ----------------------------
404 procedure Check_Discriminant_Use (N : Node_Id) is
405 PN : constant Node_Id := Parent (N);
406 Disc : constant Entity_Id := Entity (N);
411 -- Any use in a spec-expression is legal
413 if In_Spec_Expression then
416 elsif Nkind (PN) = N_Range then
418 -- Discriminant cannot be used to constrain a scalar type
422 if Nkind (P) = N_Range_Constraint
423 and then Nkind (Parent (P)) = N_Subtype_Indication
424 and then Nkind (Parent (Parent (P))) = N_Component_Definition
426 Error_Msg_N ("discriminant cannot constrain scalar type", N);
428 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
430 -- The following check catches the unusual case where a
431 -- discriminant appears within an index constraint that is part
432 -- of a larger expression within a constraint on a component,
433 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
434 -- check case of record components, and note that a similar check
435 -- should also apply in the case of discriminant constraints
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
446 if Ekind (Current_Scope) = E_Record_Type
447 and then Scope (Disc) = Current_Scope
449 (Nkind (Parent (P)) = N_Subtype_Indication
451 Nkind_In (Parent (Parent (P)), N_Component_Definition,
452 N_Subtype_Declaration)
453 and then Paren_Count (N) = 0)
456 ("discriminant must appear alone in component constraint", N);
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large : declare
477 function Large_Storage_Type (T : Entity_Id) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type (T : Entity_Id) return Boolean is
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value (Type_Low_Bound (T))
493 and then Compile_Time_Known_Value (Type_High_Bound (T))
495 Minimum_Size (T, Biased => True) >=
496 RM_Size (Standard_Positive);
497 end Large_Storage_Type;
499 -- Start of processing for Check_Large
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type (Etype (Disc)) then
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
512 if Is_Limited_Type (Scope (Disc)) then
516 -- Check that it is the high bound
518 if N /= High_Bound (PN)
519 or else No (Discriminant_Default_Value (Disc))
524 -- Check the array allows a large range at this bound. First
529 if Nkind (SI) /= N_Subtype_Indication then
533 T := Entity (Subtype_Mark (SI));
535 if not Is_Array_Type (T) then
539 -- Next, find the dimension
541 TB := First_Index (T);
542 CB := First (Constraints (P));
544 and then Present (TB)
545 and then Present (CB)
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type (Etype (TB)) then
562 -- Warn about the danger
565 ("??creation of & object may raise Storage_Error!",
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
577 N_Discriminant_Association)
579 if Paren_Count (N) > 0 then
581 ("discriminant in constraint must appear alone", N);
583 elsif Nkind (N) = N_Expanded_Name
584 and then Comes_From_Source (N)
587 ("discriminant must appear alone as a direct name", N);
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
598 while not Nkind_In (P, N_Component_Declaration,
599 N_Subtype_Indication,
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind (P) = N_Subtype_Indication
613 and then Nkind_In (Parent (P), N_Component_Definition,
614 N_Derived_Type_Definition)
615 and then D = Constraint (P))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind (P) = N_Subtype_Indication
622 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
623 or else Nkind (P) = N_Entry_Declaration
624 or else Nkind (D) = N_Defining_Identifier
627 ("discriminant in constraint must appear alone", N);
630 end Check_Discriminant_Use;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
638 if Is_Invisible_Operator (N, T) then
639 Error_Msg_NE -- CODEFIX
640 ("operator for} is not directly visible!", N, First_Subtype (T));
641 Error_Msg_N -- CODEFIX
642 ("use clause would make operation legal!", N);
644 end Check_For_Visible_Operator;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name (Pref)
674 and then Ekind (Entity (Pref)) = E_In_Parameter
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version >= Ada_2005
683 and then Is_Entity_Name (Pref)
684 and then Is_Access_Type (Etype (Pref))
685 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
687 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
691 Check_Fully_Declared (Typ, Parent (Pref));
693 end Check_Fully_Declared_Prefix;
695 ------------------------------
696 -- Check_Infinite_Recursion --
697 ------------------------------
699 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
703 function Same_Argument_List return Boolean;
704 -- Check whether list of actuals is identical to list of formals of
705 -- called function (which is also the enclosing scope).
707 ------------------------
708 -- Same_Argument_List --
709 ------------------------
711 function Same_Argument_List return Boolean is
717 if not Is_Entity_Name (Name (N)) then
720 Subp := Entity (Name (N));
723 F := First_Formal (Subp);
724 A := First_Actual (N);
725 while Present (F) and then Present (A) loop
726 if not Is_Entity_Name (A) or else Entity (A) /= F then
735 end Same_Argument_List;
737 -- Start of processing for Check_Infinite_Recursion
740 -- Special case, if this is a procedure call and is a call to the
741 -- current procedure with the same argument list, then this is for
742 -- sure an infinite recursion and we insert a call to raise SE.
744 if Is_List_Member (N)
745 and then List_Length (List_Containing (N)) = 1
746 and then Same_Argument_List
749 P : constant Node_Id := Parent (N);
751 if Nkind (P) = N_Handled_Sequence_Of_Statements
752 and then Nkind (Parent (P)) = N_Subprogram_Body
753 and then Is_Empty_List (Declarations (Parent (P)))
755 Error_Msg_Warn := SPARK_Mode /= On;
756 Error_Msg_N ("!infinite recursion<<", N);
757 Error_Msg_N ("\!Storage_Error [<<", N);
759 Make_Raise_Storage_Error (Sloc (N),
760 Reason => SE_Infinite_Recursion));
766 -- If not that special case, search up tree, quitting if we reach a
767 -- construct (e.g. a conditional) that tells us that this is not a
768 -- case for an infinite recursion warning.
774 -- If no parent, then we were not inside a subprogram, this can for
775 -- example happen when processing certain pragmas in a spec. Just
776 -- return False in this case.
782 -- Done if we get to subprogram body, this is definitely an infinite
783 -- recursion case if we did not find anything to stop us.
785 exit when Nkind (P) = N_Subprogram_Body;
787 -- If appearing in conditional, result is false
789 if Nkind_In (P, N_Or_Else,
798 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
799 and then C /= First (Statements (P))
801 -- If the call is the expression of a return statement and the
802 -- actuals are identical to the formals, it's worth a warning.
803 -- However, we skip this if there is an immediately preceding
804 -- raise statement, since the call is never executed.
806 -- Furthermore, this corresponds to a common idiom:
808 -- function F (L : Thing) return Boolean is
810 -- raise Program_Error;
814 -- for generating a stub function
816 if Nkind (Parent (N)) = N_Simple_Return_Statement
817 and then Same_Argument_List
819 exit when not Is_List_Member (Parent (N));
821 -- OK, return statement is in a statement list, look for raise
827 -- Skip past N_Freeze_Entity nodes generated by expansion
829 Nod := Prev (Parent (N));
831 and then Nkind (Nod) = N_Freeze_Entity
836 -- If no raise statement, give warning. We look at the
837 -- original node, because in the case of "raise ... with
838 -- ...", the node has been transformed into a call.
840 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
842 (Nkind (Nod) not in N_Raise_xxx_Error
843 or else Present (Condition (Nod)));
854 Error_Msg_Warn := SPARK_Mode /= On;
855 Error_Msg_N ("!possible infinite recursion<<", N);
856 Error_Msg_N ("\!??Storage_Error ]<<", N);
859 end Check_Infinite_Recursion;
861 -------------------------------
862 -- Check_Initialization_Call --
863 -------------------------------
865 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
866 Typ : constant Entity_Id := Etype (First_Formal (Nam));
868 function Uses_SS (T : Entity_Id) return Boolean;
869 -- Check whether the creation of an object of the type will involve
870 -- use of the secondary stack. If T is a record type, this is true
871 -- if the expression for some component uses the secondary stack, e.g.
872 -- through a call to a function that returns an unconstrained value.
873 -- False if T is controlled, because cleanups occur elsewhere.
879 function Uses_SS (T : Entity_Id) return Boolean is
882 Full_Type : Entity_Id := Underlying_Type (T);
885 -- Normally we want to use the underlying type, but if it's not set
886 -- then continue with T.
888 if not Present (Full_Type) then
892 if Is_Controlled (Full_Type) then
895 elsif Is_Array_Type (Full_Type) then
896 return Uses_SS (Component_Type (Full_Type));
898 elsif Is_Record_Type (Full_Type) then
899 Comp := First_Component (Full_Type);
900 while Present (Comp) loop
901 if Ekind (Comp) = E_Component
902 and then Nkind (Parent (Comp)) = N_Component_Declaration
904 -- The expression for a dynamic component may be rewritten
905 -- as a dereference, so retrieve original node.
907 Expr := Original_Node (Expression (Parent (Comp)));
909 -- Return True if the expression is a call to a function
910 -- (including an attribute function such as Image, or a
911 -- user-defined operator) with a result that requires a
914 if (Nkind (Expr) = N_Function_Call
915 or else Nkind (Expr) in N_Op
916 or else (Nkind (Expr) = N_Attribute_Reference
917 and then Present (Expressions (Expr))))
918 and then Requires_Transient_Scope (Etype (Expr))
922 elsif Uses_SS (Etype (Comp)) then
927 Next_Component (Comp);
937 -- Start of processing for Check_Initialization_Call
940 -- Establish a transient scope if the type needs it
942 if Uses_SS (Typ) then
943 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
945 end Check_Initialization_Call;
947 ---------------------------------------
948 -- Check_No_Direct_Boolean_Operators --
949 ---------------------------------------
951 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
953 if Scope (Entity (N)) = Standard_Standard
954 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
956 -- Restriction only applies to original source code
958 if Comes_From_Source (N) then
959 Check_Restriction (No_Direct_Boolean_Operators, N);
963 -- Do style check (but skip if in instance, error is on template)
966 if not In_Instance then
967 Check_Boolean_Operator (N);
970 end Check_No_Direct_Boolean_Operators;
972 ------------------------------
973 -- Check_Parameterless_Call --
974 ------------------------------
976 procedure Check_Parameterless_Call (N : Node_Id) is
979 function Prefix_Is_Access_Subp return Boolean;
980 -- If the prefix is of an access_to_subprogram type, the node must be
981 -- rewritten as a call. Ditto if the prefix is overloaded and all its
982 -- interpretations are access to subprograms.
984 ---------------------------
985 -- Prefix_Is_Access_Subp --
986 ---------------------------
988 function Prefix_Is_Access_Subp return Boolean is
993 -- If the context is an attribute reference that can apply to
994 -- functions, this is never a parameterless call (RM 4.1.4(6)).
996 if Nkind (Parent (N)) = N_Attribute_Reference
997 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1004 if not Is_Overloaded (N) then
1006 Ekind (Etype (N)) = E_Subprogram_Type
1007 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1009 Get_First_Interp (N, I, It);
1010 while Present (It.Typ) loop
1011 if Ekind (It.Typ) /= E_Subprogram_Type
1012 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1017 Get_Next_Interp (I, It);
1022 end Prefix_Is_Access_Subp;
1024 -- Start of processing for Check_Parameterless_Call
1027 -- Defend against junk stuff if errors already detected
1029 if Total_Errors_Detected /= 0 then
1030 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1032 elsif Nkind (N) in N_Has_Chars
1033 and then Chars (N) in Error_Name_Or_No_Name
1041 -- If the context expects a value, and the name is a procedure, this is
1042 -- most likely a missing 'Access. Don't try to resolve the parameterless
1043 -- call, error will be caught when the outer call is analyzed.
1045 if Is_Entity_Name (N)
1046 and then Ekind (Entity (N)) = E_Procedure
1047 and then not Is_Overloaded (N)
1049 Nkind_In (Parent (N), N_Parameter_Association,
1051 N_Procedure_Call_Statement)
1056 -- Rewrite as call if overloadable entity that is (or could be, in the
1057 -- overloaded case) a function call. If we know for sure that the entity
1058 -- is an enumeration literal, we do not rewrite it.
1060 -- If the entity is the name of an operator, it cannot be a call because
1061 -- operators cannot have default parameters. In this case, this must be
1062 -- a string whose contents coincide with an operator name. Set the kind
1063 -- of the node appropriately.
1065 if (Is_Entity_Name (N)
1066 and then Nkind (N) /= N_Operator_Symbol
1067 and then Is_Overloadable (Entity (N))
1068 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1069 or else Is_Overloaded (N)))
1071 -- Rewrite as call if it is an explicit dereference of an expression of
1072 -- a subprogram access type, and the subprogram type is not that of a
1073 -- procedure or entry.
1076 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1078 -- Rewrite as call if it is a selected component which is a function,
1079 -- this is the case of a call to a protected function (which may be
1080 -- overloaded with other protected operations).
1083 (Nkind (N) = N_Selected_Component
1084 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1086 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1088 and then Is_Overloaded (Selector_Name (N)))))
1090 -- If one of the above three conditions is met, rewrite as call. Apply
1091 -- the rewriting only once.
1094 if Nkind (Parent (N)) /= N_Function_Call
1095 or else N /= Name (Parent (N))
1098 -- This may be a prefixed call that was not fully analyzed, e.g.
1099 -- an actual in an instance.
1101 if Ada_Version >= Ada_2005
1102 and then Nkind (N) = N_Selected_Component
1103 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1105 Analyze_Selected_Component (N);
1107 if Nkind (N) /= N_Selected_Component then
1112 -- The node is the name of the parameterless call. Preserve its
1113 -- descendants, which may be complex expressions.
1115 Nam := Relocate_Node (N);
1117 -- If overloaded, overload set belongs to new copy
1119 Save_Interps (N, Nam);
1121 -- Change node to parameterless function call (note that the
1122 -- Parameter_Associations associations field is left set to Empty,
1123 -- its normal default value since there are no parameters)
1125 Change_Node (N, N_Function_Call);
1127 Set_Sloc (N, Sloc (Nam));
1131 elsif Nkind (N) = N_Parameter_Association then
1132 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1134 elsif Nkind (N) = N_Operator_Symbol then
1135 Change_Operator_Symbol_To_String_Literal (N);
1136 Set_Is_Overloaded (N, False);
1137 Set_Etype (N, Any_String);
1139 end Check_Parameterless_Call;
1141 --------------------------------
1142 -- Is_Atomic_Ref_With_Address --
1143 --------------------------------
1145 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1146 Pref : constant Node_Id := Prefix (N);
1149 if not Is_Entity_Name (Pref) then
1154 Pent : constant Entity_Id := Entity (Pref);
1155 Ptyp : constant Entity_Id := Etype (Pent);
1157 return not Is_Access_Type (Ptyp)
1158 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1159 and then Present (Address_Clause (Pent));
1162 end Is_Atomic_Ref_With_Address;
1164 -----------------------------
1165 -- Is_Definite_Access_Type --
1166 -----------------------------
1168 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1169 Btyp : constant Entity_Id := Base_Type (E);
1171 return Ekind (Btyp) = E_Access_Type
1172 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1173 and then Comes_From_Source (Btyp));
1174 end Is_Definite_Access_Type;
1176 ----------------------
1177 -- Is_Predefined_Op --
1178 ----------------------
1180 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1182 -- Predefined operators are intrinsic subprograms
1184 if not Is_Intrinsic_Subprogram (Nam) then
1188 -- A call to a back-end builtin is never a predefined operator
1190 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1194 return not Is_Generic_Instance (Nam)
1195 and then Chars (Nam) in Any_Operator_Name
1196 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1197 end Is_Predefined_Op;
1199 -----------------------------
1200 -- Make_Call_Into_Operator --
1201 -----------------------------
1203 procedure Make_Call_Into_Operator
1208 Op_Name : constant Name_Id := Chars (Op_Id);
1209 Act1 : Node_Id := First_Actual (N);
1210 Act2 : Node_Id := Next_Actual (Act1);
1211 Error : Boolean := False;
1212 Func : constant Entity_Id := Entity (Name (N));
1213 Is_Binary : constant Boolean := Present (Act2);
1215 Opnd_Type : Entity_Id;
1216 Orig_Type : Entity_Id := Empty;
1219 type Kind_Test is access function (E : Entity_Id) return Boolean;
1221 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1222 -- If the operand is not universal, and the operator is given by an
1223 -- expanded name, verify that the operand has an interpretation with a
1224 -- type defined in the given scope of the operator.
1226 function Type_In_P (Test : Kind_Test) return Entity_Id;
1227 -- Find a type of the given class in package Pack that contains the
1230 ---------------------------
1231 -- Operand_Type_In_Scope --
1232 ---------------------------
1234 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1235 Nod : constant Node_Id := Right_Opnd (Op_Node);
1240 if not Is_Overloaded (Nod) then
1241 return Scope (Base_Type (Etype (Nod))) = S;
1244 Get_First_Interp (Nod, I, It);
1245 while Present (It.Typ) loop
1246 if Scope (Base_Type (It.Typ)) = S then
1250 Get_Next_Interp (I, It);
1255 end Operand_Type_In_Scope;
1261 function Type_In_P (Test : Kind_Test) return Entity_Id is
1264 function In_Decl return Boolean;
1265 -- Verify that node is not part of the type declaration for the
1266 -- candidate type, which would otherwise be invisible.
1272 function In_Decl return Boolean is
1273 Decl_Node : constant Node_Id := Parent (E);
1279 if Etype (E) = Any_Type then
1282 elsif No (Decl_Node) then
1287 and then Nkind (N2) /= N_Compilation_Unit
1289 if N2 = Decl_Node then
1300 -- Start of processing for Type_In_P
1303 -- If the context type is declared in the prefix package, this is the
1304 -- desired base type.
1306 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1307 return Base_Type (Typ);
1310 E := First_Entity (Pack);
1311 while Present (E) loop
1312 if Test (E) and then not In_Decl then
1323 -- Start of processing for Make_Call_Into_Operator
1326 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1331 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1332 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1333 Save_Interps (Act1, Left_Opnd (Op_Node));
1334 Save_Interps (Act2, Right_Opnd (Op_Node));
1335 Act1 := Left_Opnd (Op_Node);
1336 Act2 := Right_Opnd (Op_Node);
1341 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1342 Save_Interps (Act1, Right_Opnd (Op_Node));
1343 Act1 := Right_Opnd (Op_Node);
1346 -- If the operator is denoted by an expanded name, and the prefix is
1347 -- not Standard, but the operator is a predefined one whose scope is
1348 -- Standard, then this is an implicit_operator, inserted as an
1349 -- interpretation by the procedure of the same name. This procedure
1350 -- overestimates the presence of implicit operators, because it does
1351 -- not examine the type of the operands. Verify now that the operand
1352 -- type appears in the given scope. If right operand is universal,
1353 -- check the other operand. In the case of concatenation, either
1354 -- argument can be the component type, so check the type of the result.
1355 -- If both arguments are literals, look for a type of the right kind
1356 -- defined in the given scope. This elaborate nonsense is brought to
1357 -- you courtesy of b33302a. The type itself must be frozen, so we must
1358 -- find the type of the proper class in the given scope.
1360 -- A final wrinkle is the multiplication operator for fixed point types,
1361 -- which is defined in Standard only, and not in the scope of the
1362 -- fixed point type itself.
1364 if Nkind (Name (N)) = N_Expanded_Name then
1365 Pack := Entity (Prefix (Name (N)));
1367 -- If this is a package renaming, get renamed entity, which will be
1368 -- the scope of the operands if operaton is type-correct.
1370 if Present (Renamed_Entity (Pack)) then
1371 Pack := Renamed_Entity (Pack);
1374 -- If the entity being called is defined in the given package, it is
1375 -- a renaming of a predefined operator, and known to be legal.
1377 if Scope (Entity (Name (N))) = Pack
1378 and then Pack /= Standard_Standard
1382 -- Visibility does not need to be checked in an instance: if the
1383 -- operator was not visible in the generic it has been diagnosed
1384 -- already, else there is an implicit copy of it in the instance.
1386 elsif In_Instance then
1389 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1390 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1391 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1393 if Pack /= Standard_Standard then
1397 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1400 elsif Ada_Version >= Ada_2005
1401 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1402 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1407 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1409 if Op_Name = Name_Op_Concat then
1410 Opnd_Type := Base_Type (Typ);
1412 elsif (Scope (Opnd_Type) = Standard_Standard
1414 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1416 and then not Comes_From_Source (Opnd_Type))
1418 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1421 if Scope (Opnd_Type) = Standard_Standard then
1423 -- Verify that the scope contains a type that corresponds to
1424 -- the given literal. Optimize the case where Pack is Standard.
1426 if Pack /= Standard_Standard then
1428 if Opnd_Type = Universal_Integer then
1429 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1431 elsif Opnd_Type = Universal_Real then
1432 Orig_Type := Type_In_P (Is_Real_Type'Access);
1434 elsif Opnd_Type = Any_String then
1435 Orig_Type := Type_In_P (Is_String_Type'Access);
1437 elsif Opnd_Type = Any_Access then
1438 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1440 elsif Opnd_Type = Any_Composite then
1441 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1443 if Present (Orig_Type) then
1444 if Has_Private_Component (Orig_Type) then
1447 Set_Etype (Act1, Orig_Type);
1450 Set_Etype (Act2, Orig_Type);
1459 Error := No (Orig_Type);
1462 elsif Ekind (Opnd_Type) = E_Allocator_Type
1463 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1467 -- If the type is defined elsewhere, and the operator is not
1468 -- defined in the given scope (by a renaming declaration, e.g.)
1469 -- then this is an error as well. If an extension of System is
1470 -- present, and the type may be defined there, Pack must be
1473 elsif Scope (Opnd_Type) /= Pack
1474 and then Scope (Op_Id) /= Pack
1475 and then (No (System_Aux_Id)
1476 or else Scope (Opnd_Type) /= System_Aux_Id
1477 or else Pack /= Scope (System_Aux_Id))
1479 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1482 Error := not Operand_Type_In_Scope (Pack);
1485 elsif Pack = Standard_Standard
1486 and then not Operand_Type_In_Scope (Standard_Standard)
1493 Error_Msg_Node_2 := Pack;
1495 ("& not declared in&", N, Selector_Name (Name (N)));
1496 Set_Etype (N, Any_Type);
1499 -- Detect a mismatch between the context type and the result type
1500 -- in the named package, which is otherwise not detected if the
1501 -- operands are universal. Check is only needed if source entity is
1502 -- an operator, not a function that renames an operator.
1504 elsif Nkind (Parent (N)) /= N_Type_Conversion
1505 and then Ekind (Entity (Name (N))) = E_Operator
1506 and then Is_Numeric_Type (Typ)
1507 and then not Is_Universal_Numeric_Type (Typ)
1508 and then Scope (Base_Type (Typ)) /= Pack
1509 and then not In_Instance
1511 if Is_Fixed_Point_Type (Typ)
1512 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1514 -- Already checked above
1518 -- Operator may be defined in an extension of System
1520 elsif Present (System_Aux_Id)
1521 and then Scope (Opnd_Type) = System_Aux_Id
1526 -- Could we use Wrong_Type here??? (this would require setting
1527 -- Etype (N) to the actual type found where Typ was expected).
1529 Error_Msg_NE ("expect }", N, Typ);
1534 Set_Chars (Op_Node, Op_Name);
1536 if not Is_Private_Type (Etype (N)) then
1537 Set_Etype (Op_Node, Base_Type (Etype (N)));
1539 Set_Etype (Op_Node, Etype (N));
1542 -- If this is a call to a function that renames a predefined equality,
1543 -- the renaming declaration provides a type that must be used to
1544 -- resolve the operands. This must be done now because resolution of
1545 -- the equality node will not resolve any remaining ambiguity, and it
1546 -- assumes that the first operand is not overloaded.
1548 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1549 and then Ekind (Func) = E_Function
1550 and then Is_Overloaded (Act1)
1552 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1553 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1556 Set_Entity (Op_Node, Op_Id);
1557 Generate_Reference (Op_Id, N, ' ');
1559 -- Do rewrite setting Comes_From_Source on the result if the original
1560 -- call came from source. Although it is not strictly the case that the
1561 -- operator as such comes from the source, logically it corresponds
1562 -- exactly to the function call in the source, so it should be marked
1563 -- this way (e.g. to make sure that validity checks work fine).
1566 CS : constant Boolean := Comes_From_Source (N);
1568 Rewrite (N, Op_Node);
1569 Set_Comes_From_Source (N, CS);
1572 -- If this is an arithmetic operator and the result type is private,
1573 -- the operands and the result must be wrapped in conversion to
1574 -- expose the underlying numeric type and expand the proper checks,
1575 -- e.g. on division.
1577 if Is_Private_Type (Typ) then
1579 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1580 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1581 Resolve_Intrinsic_Operator (N, Typ);
1583 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1584 Resolve_Intrinsic_Unary_Operator (N, Typ);
1593 -- If in ASIS_Mode, propagate operand types to original actuals of
1594 -- function call, which would otherwise not be fully resolved. If
1595 -- the call has already been constant-folded, nothing to do. We
1596 -- relocate the operand nodes rather than copy them, to preserve
1597 -- original_node pointers, given that the operands themselves may
1598 -- have been rewritten. If the call was itself a rewriting of an
1599 -- operator node, nothing to do.
1602 and then Nkind (N) in N_Op
1603 and then Nkind (Original_Node (N)) = N_Function_Call
1607 R : constant Node_Id := Right_Opnd (N);
1609 Old_First : constant Node_Id :=
1610 First (Parameter_Associations (Original_Node (N)));
1616 Old_Sec := Next (Old_First);
1618 -- If the original call has named associations, replace the
1619 -- explicit actual parameter in the association with the proper
1620 -- resolved operand.
1622 if Nkind (Old_First) = N_Parameter_Association then
1623 if Chars (Selector_Name (Old_First)) =
1624 Chars (First_Entity (Op_Id))
1626 Rewrite (Explicit_Actual_Parameter (Old_First),
1629 Rewrite (Explicit_Actual_Parameter (Old_First),
1634 Rewrite (Old_First, Relocate_Node (L));
1637 if Nkind (Old_Sec) = N_Parameter_Association then
1638 if Chars (Selector_Name (Old_Sec)) =
1639 Chars (First_Entity (Op_Id))
1641 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1644 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1649 Rewrite (Old_Sec, Relocate_Node (R));
1653 if Nkind (Old_First) = N_Parameter_Association then
1654 Rewrite (Explicit_Actual_Parameter (Old_First),
1657 Rewrite (Old_First, Relocate_Node (R));
1662 Set_Parent (Original_Node (N), Parent (N));
1664 end Make_Call_Into_Operator;
1670 function Operator_Kind
1672 Is_Binary : Boolean) return Node_Kind
1677 -- Use CASE statement or array???
1680 if Op_Name = Name_Op_And then
1682 elsif Op_Name = Name_Op_Or then
1684 elsif Op_Name = Name_Op_Xor then
1686 elsif Op_Name = Name_Op_Eq then
1688 elsif Op_Name = Name_Op_Ne then
1690 elsif Op_Name = Name_Op_Lt then
1692 elsif Op_Name = Name_Op_Le then
1694 elsif Op_Name = Name_Op_Gt then
1696 elsif Op_Name = Name_Op_Ge then
1698 elsif Op_Name = Name_Op_Add then
1700 elsif Op_Name = Name_Op_Subtract then
1701 Kind := N_Op_Subtract;
1702 elsif Op_Name = Name_Op_Concat then
1703 Kind := N_Op_Concat;
1704 elsif Op_Name = Name_Op_Multiply then
1705 Kind := N_Op_Multiply;
1706 elsif Op_Name = Name_Op_Divide then
1707 Kind := N_Op_Divide;
1708 elsif Op_Name = Name_Op_Mod then
1710 elsif Op_Name = Name_Op_Rem then
1712 elsif Op_Name = Name_Op_Expon then
1715 raise Program_Error;
1721 if Op_Name = Name_Op_Add then
1723 elsif Op_Name = Name_Op_Subtract then
1725 elsif Op_Name = Name_Op_Abs then
1727 elsif Op_Name = Name_Op_Not then
1730 raise Program_Error;
1737 ----------------------------
1738 -- Preanalyze_And_Resolve --
1739 ----------------------------
1741 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1742 Save_Full_Analysis : constant Boolean := Full_Analysis;
1745 Full_Analysis := False;
1746 Expander_Mode_Save_And_Set (False);
1748 -- Normally, we suppress all checks for this preanalysis. There is no
1749 -- point in processing them now, since they will be applied properly
1750 -- and in the proper location when the default expressions reanalyzed
1751 -- and reexpanded later on. We will also have more information at that
1752 -- point for possible suppression of individual checks.
1754 -- However, in SPARK mode, most expansion is suppressed, and this
1755 -- later reanalysis and reexpansion may not occur. SPARK mode does
1756 -- require the setting of checking flags for proof purposes, so we
1757 -- do the SPARK preanalysis without suppressing checks.
1759 -- This special handling for SPARK mode is required for example in the
1760 -- case of Ada 2012 constructs such as quantified expressions, which are
1761 -- expanded in two separate steps.
1763 if GNATprove_Mode then
1764 Analyze_And_Resolve (N, T);
1766 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1769 Expander_Mode_Restore;
1770 Full_Analysis := Save_Full_Analysis;
1771 end Preanalyze_And_Resolve;
1773 -- Version without context type
1775 procedure Preanalyze_And_Resolve (N : Node_Id) is
1776 Save_Full_Analysis : constant Boolean := Full_Analysis;
1779 Full_Analysis := False;
1780 Expander_Mode_Save_And_Set (False);
1783 Resolve (N, Etype (N), Suppress => All_Checks);
1785 Expander_Mode_Restore;
1786 Full_Analysis := Save_Full_Analysis;
1787 end Preanalyze_And_Resolve;
1789 ----------------------------------
1790 -- Replace_Actual_Discriminants --
1791 ----------------------------------
1793 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1794 Loc : constant Source_Ptr := Sloc (N);
1795 Tsk : Node_Id := Empty;
1797 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1798 -- Comment needed???
1804 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1808 if Nkind (Nod) = N_Identifier then
1809 Ent := Entity (Nod);
1812 and then Ekind (Ent) = E_Discriminant
1815 Make_Selected_Component (Loc,
1816 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1817 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1819 Set_Etype (Nod, Etype (Ent));
1827 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1829 -- Start of processing for Replace_Actual_Discriminants
1832 if not Expander_Active then
1836 if Nkind (Name (N)) = N_Selected_Component then
1837 Tsk := Prefix (Name (N));
1839 elsif Nkind (Name (N)) = N_Indexed_Component then
1840 Tsk := Prefix (Prefix (Name (N)));
1846 Replace_Discrs (Default);
1848 end Replace_Actual_Discriminants;
1854 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1855 Ambiguous : Boolean := False;
1856 Ctx_Type : Entity_Id := Typ;
1857 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1858 Err_Type : Entity_Id := Empty;
1859 Found : Boolean := False;
1862 I1 : Interp_Index := 0; -- prevent junk warning
1865 Seen : Entity_Id := Empty; -- prevent junk warning
1867 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1868 -- Determine whether a node comes from a predefined library unit or
1871 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1872 -- Try and fix up a literal so that it matches its expected type. New
1873 -- literals are manufactured if necessary to avoid cascaded errors.
1875 procedure Report_Ambiguous_Argument;
1876 -- Additional diagnostics when an ambiguous call has an ambiguous
1877 -- argument (typically a controlling actual).
1879 procedure Resolution_Failed;
1880 -- Called when attempt at resolving current expression fails
1882 ------------------------------------
1883 -- Comes_From_Predefined_Lib_Unit --
1884 -------------------------------------
1886 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1889 Sloc (Nod) = Standard_Location
1890 or else Is_Predefined_File_Name
1891 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1892 end Comes_From_Predefined_Lib_Unit;
1894 --------------------
1895 -- Patch_Up_Value --
1896 --------------------
1898 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1900 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1902 Make_Real_Literal (Sloc (N),
1903 Realval => UR_From_Uint (Intval (N))));
1904 Set_Etype (N, Universal_Real);
1905 Set_Is_Static_Expression (N);
1907 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1909 Make_Integer_Literal (Sloc (N),
1910 Intval => UR_To_Uint (Realval (N))));
1911 Set_Etype (N, Universal_Integer);
1912 Set_Is_Static_Expression (N);
1914 elsif Nkind (N) = N_String_Literal
1915 and then Is_Character_Type (Typ)
1917 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1919 Make_Character_Literal (Sloc (N),
1921 Char_Literal_Value =>
1922 UI_From_Int (Character'Pos ('A'))));
1923 Set_Etype (N, Any_Character);
1924 Set_Is_Static_Expression (N);
1926 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1928 Make_String_Literal (Sloc (N),
1929 Strval => End_String));
1931 elsif Nkind (N) = N_Range then
1932 Patch_Up_Value (Low_Bound (N), Typ);
1933 Patch_Up_Value (High_Bound (N), Typ);
1937 -------------------------------
1938 -- Report_Ambiguous_Argument --
1939 -------------------------------
1941 procedure Report_Ambiguous_Argument is
1942 Arg : constant Node_Id := First (Parameter_Associations (N));
1947 if Nkind (Arg) = N_Function_Call
1948 and then Is_Entity_Name (Name (Arg))
1949 and then Is_Overloaded (Name (Arg))
1951 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1953 -- Could use comments on what is going on here???
1955 Get_First_Interp (Name (Arg), I, It);
1956 while Present (It.Nam) loop
1957 Error_Msg_Sloc := Sloc (It.Nam);
1959 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1960 Error_Msg_N ("interpretation (inherited) #!", Arg);
1962 Error_Msg_N ("interpretation #!", Arg);
1965 Get_Next_Interp (I, It);
1968 end Report_Ambiguous_Argument;
1970 -----------------------
1971 -- Resolution_Failed --
1972 -----------------------
1974 procedure Resolution_Failed is
1976 Patch_Up_Value (N, Typ);
1978 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1979 Set_Is_Overloaded (N, False);
1981 -- The caller will return without calling the expander, so we need
1982 -- to set the analyzed flag. Note that it is fine to set Analyzed
1983 -- to True even if we are in the middle of a shallow analysis,
1984 -- (see the spec of sem for more details) since this is an error
1985 -- situation anyway, and there is no point in repeating the
1986 -- analysis later (indeed it won't work to repeat it later, since
1987 -- we haven't got a clear resolution of which entity is being
1990 Set_Analyzed (N, True);
1992 end Resolution_Failed;
1996 Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
1998 -- Start of processing for Resolve
2005 -- A declaration may be subject to pragma Ghost. Set the mode now to
2006 -- ensure that any nodes generated during analysis and expansion are
2009 if Is_Declaration (N) then
2013 -- Access attribute on remote subprogram cannot be used for a non-remote
2014 -- access-to-subprogram type.
2016 if Nkind (N) = N_Attribute_Reference
2017 and then Nam_In (Attribute_Name (N), Name_Access,
2018 Name_Unrestricted_Access,
2019 Name_Unchecked_Access)
2020 and then Comes_From_Source (N)
2021 and then Is_Entity_Name (Prefix (N))
2022 and then Is_Subprogram (Entity (Prefix (N)))
2023 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2024 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2027 ("prefix must statically denote a non-remote subprogram", N);
2030 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2032 -- If the context is a Remote_Access_To_Subprogram, access attributes
2033 -- must be resolved with the corresponding fat pointer. There is no need
2034 -- to check for the attribute name since the return type of an
2035 -- attribute is never a remote type.
2037 if Nkind (N) = N_Attribute_Reference
2038 and then Comes_From_Source (N)
2039 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2042 Attr : constant Attribute_Id :=
2043 Get_Attribute_Id (Attribute_Name (N));
2044 Pref : constant Node_Id := Prefix (N);
2047 Is_Remote : Boolean := True;
2050 -- Check that Typ is a remote access-to-subprogram type
2052 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2054 -- Prefix (N) must statically denote a remote subprogram
2055 -- declared in a package specification.
2057 if Attr = Attribute_Access or else
2058 Attr = Attribute_Unchecked_Access or else
2059 Attr = Attribute_Unrestricted_Access
2061 Decl := Unit_Declaration_Node (Entity (Pref));
2063 if Nkind (Decl) = N_Subprogram_Body then
2064 Spec := Corresponding_Spec (Decl);
2066 if Present (Spec) then
2067 Decl := Unit_Declaration_Node (Spec);
2071 Spec := Parent (Decl);
2073 if not Is_Entity_Name (Prefix (N))
2074 or else Nkind (Spec) /= N_Package_Specification
2076 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2080 ("prefix must statically denote a remote subprogram ",
2084 -- If we are generating code in distributed mode, perform
2085 -- semantic checks against corresponding remote entities.
2088 and then Get_PCS_Name /= Name_No_DSA
2090 Check_Subtype_Conformant
2091 (New_Id => Entity (Prefix (N)),
2092 Old_Id => Designated_Type
2093 (Corresponding_Remote_Type (Typ)),
2097 Process_Remote_AST_Attribute (N, Typ);
2105 Debug_A_Entry ("resolving ", N);
2107 if Debug_Flag_V then
2108 Write_Overloads (N);
2111 if Comes_From_Source (N) then
2112 if Is_Fixed_Point_Type (Typ) then
2113 Check_Restriction (No_Fixed_Point, N);
2115 elsif Is_Floating_Point_Type (Typ)
2116 and then Typ /= Universal_Real
2117 and then Typ /= Any_Real
2119 Check_Restriction (No_Floating_Point, N);
2123 -- Return if already analyzed
2125 if Analyzed (N) then
2126 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2127 Analyze_Dimension (N);
2128 Ghost_Mode := Save_Ghost_Mode;
2131 -- Any case of Any_Type as the Etype value means that we had a
2134 elsif Etype (N) = Any_Type then
2135 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2136 Ghost_Mode := Save_Ghost_Mode;
2140 Check_Parameterless_Call (N);
2142 -- The resolution of an Expression_With_Actions is determined by
2145 if Nkind (N) = N_Expression_With_Actions then
2146 Resolve (Expression (N), Typ);
2149 Expr_Type := Etype (Expression (N));
2151 -- If not overloaded, then we know the type, and all that needs doing
2152 -- is to check that this type is compatible with the context.
2154 elsif not Is_Overloaded (N) then
2155 Found := Covers (Typ, Etype (N));
2156 Expr_Type := Etype (N);
2158 -- In the overloaded case, we must select the interpretation that
2159 -- is compatible with the context (i.e. the type passed to Resolve)
2162 -- Loop through possible interpretations
2164 Get_First_Interp (N, I, It);
2165 Interp_Loop : while Present (It.Typ) loop
2166 if Debug_Flag_V then
2167 Write_Str ("Interp: ");
2171 -- We are only interested in interpretations that are compatible
2172 -- with the expected type, any other interpretations are ignored.
2174 if not Covers (Typ, It.Typ) then
2175 if Debug_Flag_V then
2176 Write_Str (" interpretation incompatible with context");
2181 -- Skip the current interpretation if it is disabled by an
2182 -- abstract operator. This action is performed only when the
2183 -- type against which we are resolving is the same as the
2184 -- type of the interpretation.
2186 if Ada_Version >= Ada_2005
2187 and then It.Typ = Typ
2188 and then Typ /= Universal_Integer
2189 and then Typ /= Universal_Real
2190 and then Present (It.Abstract_Op)
2192 if Debug_Flag_V then
2193 Write_Line ("Skip.");
2199 -- First matching interpretation
2205 Expr_Type := It.Typ;
2207 -- Matching interpretation that is not the first, maybe an
2208 -- error, but there are some cases where preference rules are
2209 -- used to choose between the two possibilities. These and
2210 -- some more obscure cases are handled in Disambiguate.
2213 -- If the current statement is part of a predefined library
2214 -- unit, then all interpretations which come from user level
2215 -- packages should not be considered. Check previous and
2219 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2222 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2224 -- Previous interpretation must be discarded
2228 Expr_Type := It.Typ;
2229 Set_Entity (N, Seen);
2234 -- Otherwise apply further disambiguation steps
2236 Error_Msg_Sloc := Sloc (Seen);
2237 It1 := Disambiguate (N, I1, I, Typ);
2239 -- Disambiguation has succeeded. Skip the remaining
2242 if It1 /= No_Interp then
2244 Expr_Type := It1.Typ;
2246 while Present (It.Typ) loop
2247 Get_Next_Interp (I, It);
2251 -- Before we issue an ambiguity complaint, check for
2252 -- the case of a subprogram call where at least one
2253 -- of the arguments is Any_Type, and if so, suppress
2254 -- the message, since it is a cascaded error.
2256 if Nkind (N) in N_Subprogram_Call then
2262 A := First_Actual (N);
2263 while Present (A) loop
2266 if Nkind (E) = N_Parameter_Association then
2267 E := Explicit_Actual_Parameter (E);
2270 if Etype (E) = Any_Type then
2271 if Debug_Flag_V then
2272 Write_Str ("Any_Type in call");
2283 elsif Nkind (N) in N_Binary_Op
2284 and then (Etype (Left_Opnd (N)) = Any_Type
2285 or else Etype (Right_Opnd (N)) = Any_Type)
2289 elsif Nkind (N) in N_Unary_Op
2290 and then Etype (Right_Opnd (N)) = Any_Type
2295 -- Not that special case, so issue message using the
2296 -- flag Ambiguous to control printing of the header
2297 -- message only at the start of an ambiguous set.
2299 if not Ambiguous then
2300 if Nkind (N) = N_Function_Call
2301 and then Nkind (Name (N)) = N_Explicit_Dereference
2304 ("ambiguous expression "
2305 & "(cannot resolve indirect call)!", N);
2307 Error_Msg_NE -- CODEFIX
2308 ("ambiguous expression (cannot resolve&)!",
2314 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2316 ("\\possible interpretation (inherited)#!", N);
2318 Error_Msg_N -- CODEFIX
2319 ("\\possible interpretation#!", N);
2322 if Nkind (N) in N_Subprogram_Call
2323 and then Present (Parameter_Associations (N))
2325 Report_Ambiguous_Argument;
2329 Error_Msg_Sloc := Sloc (It.Nam);
2331 -- By default, the error message refers to the candidate
2332 -- interpretation. But if it is a predefined operator, it
2333 -- is implicitly declared at the declaration of the type
2334 -- of the operand. Recover the sloc of that declaration
2335 -- for the error message.
2337 if Nkind (N) in N_Op
2338 and then Scope (It.Nam) = Standard_Standard
2339 and then not Is_Overloaded (Right_Opnd (N))
2340 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2343 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2345 if Comes_From_Source (Err_Type)
2346 and then Present (Parent (Err_Type))
2348 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2351 elsif Nkind (N) in N_Binary_Op
2352 and then Scope (It.Nam) = Standard_Standard
2353 and then not Is_Overloaded (Left_Opnd (N))
2354 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2357 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2359 if Comes_From_Source (Err_Type)
2360 and then Present (Parent (Err_Type))
2362 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2365 -- If this is an indirect call, use the subprogram_type
2366 -- in the message, to have a meaningful location. Also
2367 -- indicate if this is an inherited operation, created
2368 -- by a type declaration.
2370 elsif Nkind (N) = N_Function_Call
2371 and then Nkind (Name (N)) = N_Explicit_Dereference
2372 and then Is_Type (It.Nam)
2376 Sloc (Associated_Node_For_Itype (Err_Type));
2381 if Nkind (N) in N_Op
2382 and then Scope (It.Nam) = Standard_Standard
2383 and then Present (Err_Type)
2385 -- Special-case the message for universal_fixed
2386 -- operators, which are not declared with the type
2387 -- of the operand, but appear forever in Standard.
2389 if It.Typ = Universal_Fixed
2390 and then Scope (It.Nam) = Standard_Standard
2393 ("\\possible interpretation as universal_fixed "
2394 & "operation (RM 4.5.5 (19))", N);
2397 ("\\possible interpretation (predefined)#!", N);
2401 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2404 ("\\possible interpretation (inherited)#!", N);
2406 Error_Msg_N -- CODEFIX
2407 ("\\possible interpretation#!", N);
2413 -- We have a matching interpretation, Expr_Type is the type
2414 -- from this interpretation, and Seen is the entity.
2416 -- For an operator, just set the entity name. The type will be
2417 -- set by the specific operator resolution routine.
2419 if Nkind (N) in N_Op then
2420 Set_Entity (N, Seen);
2421 Generate_Reference (Seen, N);
2423 elsif Nkind (N) = N_Case_Expression then
2424 Set_Etype (N, Expr_Type);
2426 elsif Nkind (N) = N_Character_Literal then
2427 Set_Etype (N, Expr_Type);
2429 elsif Nkind (N) = N_If_Expression then
2430 Set_Etype (N, Expr_Type);
2432 -- AI05-0139-2: Expression is overloaded because type has
2433 -- implicit dereference. If type matches context, no implicit
2434 -- dereference is involved.
2436 elsif Has_Implicit_Dereference (Expr_Type) then
2437 Set_Etype (N, Expr_Type);
2438 Set_Is_Overloaded (N, False);
2441 elsif Is_Overloaded (N)
2442 and then Present (It.Nam)
2443 and then Ekind (It.Nam) = E_Discriminant
2444 and then Has_Implicit_Dereference (It.Nam)
2446 -- If the node is a general indexing, the dereference is
2447 -- is inserted when resolving the rewritten form, else
2450 if Nkind (N) /= N_Indexed_Component
2451 or else No (Generalized_Indexing (N))
2453 Build_Explicit_Dereference (N, It.Nam);
2456 -- For an explicit dereference, attribute reference, range,
2457 -- short-circuit form (which is not an operator node), or call
2458 -- with a name that is an explicit dereference, there is
2459 -- nothing to be done at this point.
2461 elsif Nkind_In (N, N_Explicit_Dereference,
2462 N_Attribute_Reference,
2464 N_Indexed_Component,
2467 N_Selected_Component,
2469 or else Nkind (Name (N)) = N_Explicit_Dereference
2473 -- For procedure or function calls, set the type of the name,
2474 -- and also the entity pointer for the prefix.
2476 elsif Nkind (N) in N_Subprogram_Call
2477 and then Is_Entity_Name (Name (N))
2479 Set_Etype (Name (N), Expr_Type);
2480 Set_Entity (Name (N), Seen);
2481 Generate_Reference (Seen, Name (N));
2483 elsif Nkind (N) = N_Function_Call
2484 and then Nkind (Name (N)) = N_Selected_Component
2486 Set_Etype (Name (N), Expr_Type);
2487 Set_Entity (Selector_Name (Name (N)), Seen);
2488 Generate_Reference (Seen, Selector_Name (Name (N)));
2490 -- For all other cases, just set the type of the Name
2493 Set_Etype (Name (N), Expr_Type);
2500 -- Move to next interpretation
2502 exit Interp_Loop when No (It.Typ);
2504 Get_Next_Interp (I, It);
2505 end loop Interp_Loop;
2508 -- At this stage Found indicates whether or not an acceptable
2509 -- interpretation exists. If not, then we have an error, except that if
2510 -- the context is Any_Type as a result of some other error, then we
2511 -- suppress the error report.
2514 if Typ /= Any_Type then
2516 -- If type we are looking for is Void, then this is the procedure
2517 -- call case, and the error is simply that what we gave is not a
2518 -- procedure name (we think of procedure calls as expressions with
2519 -- types internally, but the user doesn't think of them this way).
2521 if Typ = Standard_Void_Type then
2523 -- Special case message if function used as a procedure
2525 if Nkind (N) = N_Procedure_Call_Statement
2526 and then Is_Entity_Name (Name (N))
2527 and then Ekind (Entity (Name (N))) = E_Function
2530 ("cannot use function & in a procedure call",
2531 Name (N), Entity (Name (N)));
2533 -- Otherwise give general message (not clear what cases this
2534 -- covers, but no harm in providing for them).
2537 Error_Msg_N ("expect procedure name in procedure call", N);
2542 -- Otherwise we do have a subexpression with the wrong type
2544 -- Check for the case of an allocator which uses an access type
2545 -- instead of the designated type. This is a common error and we
2546 -- specialize the message, posting an error on the operand of the
2547 -- allocator, complaining that we expected the designated type of
2550 elsif Nkind (N) = N_Allocator
2551 and then Is_Access_Type (Typ)
2552 and then Is_Access_Type (Etype (N))
2553 and then Designated_Type (Etype (N)) = Typ
2555 Wrong_Type (Expression (N), Designated_Type (Typ));
2558 -- Check for view mismatch on Null in instances, for which the
2559 -- view-swapping mechanism has no identifier.
2561 elsif (In_Instance or else In_Inlined_Body)
2562 and then (Nkind (N) = N_Null)
2563 and then Is_Private_Type (Typ)
2564 and then Is_Access_Type (Full_View (Typ))
2566 Resolve (N, Full_View (Typ));
2568 Ghost_Mode := Save_Ghost_Mode;
2571 -- Check for an aggregate. Sometimes we can get bogus aggregates
2572 -- from misuse of parentheses, and we are about to complain about
2573 -- the aggregate without even looking inside it.
2575 -- Instead, if we have an aggregate of type Any_Composite, then
2576 -- analyze and resolve the component fields, and then only issue
2577 -- another message if we get no errors doing this (otherwise
2578 -- assume that the errors in the aggregate caused the problem).
2580 elsif Nkind (N) = N_Aggregate
2581 and then Etype (N) = Any_Composite
2583 -- Disable expansion in any case. If there is a type mismatch
2584 -- it may be fatal to try to expand the aggregate. The flag
2585 -- would otherwise be set to false when the error is posted.
2587 Expander_Active := False;
2590 procedure Check_Aggr (Aggr : Node_Id);
2591 -- Check one aggregate, and set Found to True if we have a
2592 -- definite error in any of its elements
2594 procedure Check_Elmt (Aelmt : Node_Id);
2595 -- Check one element of aggregate and set Found to True if
2596 -- we definitely have an error in the element.
2602 procedure Check_Aggr (Aggr : Node_Id) is
2606 if Present (Expressions (Aggr)) then
2607 Elmt := First (Expressions (Aggr));
2608 while Present (Elmt) loop
2614 if Present (Component_Associations (Aggr)) then
2615 Elmt := First (Component_Associations (Aggr));
2616 while Present (Elmt) loop
2618 -- If this is a default-initialized component, then
2619 -- there is nothing to check. The box will be
2620 -- replaced by the appropriate call during late
2623 if not Box_Present (Elmt) then
2624 Check_Elmt (Expression (Elmt));
2636 procedure Check_Elmt (Aelmt : Node_Id) is
2638 -- If we have a nested aggregate, go inside it (to
2639 -- attempt a naked analyze-resolve of the aggregate can
2640 -- cause undesirable cascaded errors). Do not resolve
2641 -- expression if it needs a type from context, as for
2642 -- integer * fixed expression.
2644 if Nkind (Aelmt) = N_Aggregate then
2650 if not Is_Overloaded (Aelmt)
2651 and then Etype (Aelmt) /= Any_Fixed
2656 if Etype (Aelmt) = Any_Type then
2667 -- Looks like we have a type error, but check for special case
2668 -- of Address wanted, integer found, with the configuration pragma
2669 -- Allow_Integer_Address active. If we have this case, introduce
2670 -- an unchecked conversion to allow the integer expression to be
2671 -- treated as an Address. The reverse case of integer wanted,
2672 -- Address found, is treated in an analogous manner.
2674 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2675 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2676 Analyze_And_Resolve (N, Typ);
2677 Ghost_Mode := Save_Ghost_Mode;
2681 -- That special Allow_Integer_Address check did not appply, so we
2682 -- have a real type error. If an error message was issued already,
2683 -- Found got reset to True, so if it's still False, issue standard
2684 -- Wrong_Type message.
2687 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2689 Subp_Name : Node_Id;
2692 if Is_Entity_Name (Name (N)) then
2693 Subp_Name := Name (N);
2695 elsif Nkind (Name (N)) = N_Selected_Component then
2697 -- Protected operation: retrieve operation name
2699 Subp_Name := Selector_Name (Name (N));
2702 raise Program_Error;
2705 Error_Msg_Node_2 := Typ;
2707 ("no visible interpretation of& "
2708 & "matches expected type&", N, Subp_Name);
2711 if All_Errors_Mode then
2713 Index : Interp_Index;
2717 Error_Msg_N ("\\possible interpretations:", N);
2719 Get_First_Interp (Name (N), Index, It);
2720 while Present (It.Nam) loop
2721 Error_Msg_Sloc := Sloc (It.Nam);
2722 Error_Msg_Node_2 := It.Nam;
2724 ("\\ type& for & declared#", N, It.Typ);
2725 Get_Next_Interp (Index, It);
2730 Error_Msg_N ("\use -gnatf for details", N);
2734 Wrong_Type (N, Typ);
2740 Ghost_Mode := Save_Ghost_Mode;
2743 -- Test if we have more than one interpretation for the context
2745 elsif Ambiguous then
2747 Ghost_Mode := Save_Ghost_Mode;
2750 -- Only one intepretation
2753 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2754 -- the "+" on T is abstract, and the operands are of universal type,
2755 -- the above code will have (incorrectly) resolved the "+" to the
2756 -- universal one in Standard. Therefore check for this case and give
2757 -- an error. We can't do this earlier, because it would cause legal
2758 -- cases to get errors (when some other type has an abstract "+").
2760 if Ada_Version >= Ada_2005
2761 and then Nkind (N) in N_Op
2762 and then Is_Overloaded (N)
2763 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2765 Get_First_Interp (N, I, It);
2766 while Present (It.Typ) loop
2767 if Present (It.Abstract_Op) and then
2768 Etype (It.Abstract_Op) = Typ
2771 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2775 Get_Next_Interp (I, It);
2779 -- Here we have an acceptable interpretation for the context
2781 -- Propagate type information and normalize tree for various
2782 -- predefined operations. If the context only imposes a class of
2783 -- types, rather than a specific type, propagate the actual type
2786 if Typ = Any_Integer or else
2787 Typ = Any_Boolean or else
2788 Typ = Any_Modular or else
2789 Typ = Any_Real or else
2792 Ctx_Type := Expr_Type;
2794 -- Any_Fixed is legal in a real context only if a specific fixed-
2795 -- point type is imposed. If Norman Cohen can be confused by this,
2796 -- it deserves a separate message.
2799 and then Expr_Type = Any_Fixed
2801 Error_Msg_N ("illegal context for mixed mode operation", N);
2802 Set_Etype (N, Universal_Real);
2803 Ctx_Type := Universal_Real;
2807 -- A user-defined operator is transformed into a function call at
2808 -- this point, so that further processing knows that operators are
2809 -- really operators (i.e. are predefined operators). User-defined
2810 -- operators that are intrinsic are just renamings of the predefined
2811 -- ones, and need not be turned into calls either, but if they rename
2812 -- a different operator, we must transform the node accordingly.
2813 -- Instantiations of Unchecked_Conversion are intrinsic but are
2814 -- treated as functions, even if given an operator designator.
2816 if Nkind (N) in N_Op
2817 and then Present (Entity (N))
2818 and then Ekind (Entity (N)) /= E_Operator
2821 if not Is_Predefined_Op (Entity (N)) then
2822 Rewrite_Operator_As_Call (N, Entity (N));
2824 elsif Present (Alias (Entity (N)))
2826 Nkind (Parent (Parent (Entity (N)))) =
2827 N_Subprogram_Renaming_Declaration
2829 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2831 -- If the node is rewritten, it will be fully resolved in
2832 -- Rewrite_Renamed_Operator.
2834 if Analyzed (N) then
2835 Ghost_Mode := Save_Ghost_Mode;
2841 case N_Subexpr'(Nkind (N)) is
2843 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2845 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2847 when N_Short_Circuit
2848 => Resolve_Short_Circuit (N, Ctx_Type);
2850 when N_Attribute_Reference
2851 => Resolve_Attribute (N, Ctx_Type);
2853 when N_Case_Expression
2854 => Resolve_Case_Expression (N, Ctx_Type);
2856 when N_Character_Literal
2857 => Resolve_Character_Literal (N, Ctx_Type);
2859 when N_Expanded_Name
2860 => Resolve_Entity_Name (N, Ctx_Type);
2862 when N_Explicit_Dereference
2863 => Resolve_Explicit_Dereference (N, Ctx_Type);
2865 when N_Expression_With_Actions
2866 => Resolve_Expression_With_Actions (N, Ctx_Type);
2868 when N_Extension_Aggregate
2869 => Resolve_Extension_Aggregate (N, Ctx_Type);
2871 when N_Function_Call
2872 => Resolve_Call (N, Ctx_Type);
2875 => Resolve_Entity_Name (N, Ctx_Type);
2877 when N_If_Expression
2878 => Resolve_If_Expression (N, Ctx_Type);
2880 when N_Indexed_Component
2881 => Resolve_Indexed_Component (N, Ctx_Type);
2883 when N_Integer_Literal
2884 => Resolve_Integer_Literal (N, Ctx_Type);
2886 when N_Membership_Test
2887 => Resolve_Membership_Op (N, Ctx_Type);
2889 when N_Null => Resolve_Null (N, Ctx_Type);
2891 when N_Op_And | N_Op_Or | N_Op_Xor
2892 => Resolve_Logical_Op (N, Ctx_Type);
2894 when N_Op_Eq | N_Op_Ne
2895 => Resolve_Equality_Op (N, Ctx_Type);
2897 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2898 => Resolve_Comparison_Op (N, Ctx_Type);
2900 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2902 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2903 N_Op_Divide | N_Op_Mod | N_Op_Rem
2905 => Resolve_Arithmetic_Op (N, Ctx_Type);
2907 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2909 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2911 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2912 => Resolve_Unary_Op (N, Ctx_Type);
2914 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2916 when N_Procedure_Call_Statement
2917 => Resolve_Call (N, Ctx_Type);
2919 when N_Operator_Symbol
2920 => Resolve_Operator_Symbol (N, Ctx_Type);
2922 when N_Qualified_Expression
2923 => Resolve_Qualified_Expression (N, Ctx_Type);
2925 -- Why is the following null, needs a comment ???
2927 when N_Quantified_Expression
2930 when N_Raise_Expression
2931 => Resolve_Raise_Expression (N, Ctx_Type);
2933 when N_Raise_xxx_Error
2934 => Set_Etype (N, Ctx_Type);
2936 when N_Range => Resolve_Range (N, Ctx_Type);
2939 => Resolve_Real_Literal (N, Ctx_Type);
2941 when N_Reference => Resolve_Reference (N, Ctx_Type);
2943 when N_Selected_Component
2944 => Resolve_Selected_Component (N, Ctx_Type);
2946 when N_Slice => Resolve_Slice (N, Ctx_Type);
2948 when N_String_Literal
2949 => Resolve_String_Literal (N, Ctx_Type);
2951 when N_Type_Conversion
2952 => Resolve_Type_Conversion (N, Ctx_Type);
2954 when N_Unchecked_Expression =>
2955 Resolve_Unchecked_Expression (N, Ctx_Type);
2957 when N_Unchecked_Type_Conversion =>
2958 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2961 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2962 -- expression of an anonymous access type that occurs in the context
2963 -- of a named general access type, except when the expression is that
2964 -- of a membership test. This ensures proper legality checking in
2965 -- terms of allowed conversions (expressions that would be illegal to
2966 -- convert implicitly are allowed in membership tests).
2968 if Ada_Version >= Ada_2012
2969 and then Ekind (Ctx_Type) = E_General_Access_Type
2970 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2971 and then Nkind (Parent (N)) not in N_Membership_Test
2973 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2974 Analyze_And_Resolve (N, Ctx_Type);
2977 -- If the subexpression was replaced by a non-subexpression, then
2978 -- all we do is to expand it. The only legitimate case we know of
2979 -- is converting procedure call statement to entry call statements,
2980 -- but there may be others, so we are making this test general.
2982 if Nkind (N) not in N_Subexpr then
2983 Debug_A_Exit ("resolving ", N, " (done)");
2985 Ghost_Mode := Save_Ghost_Mode;
2989 -- The expression is definitely NOT overloaded at this point, so
2990 -- we reset the Is_Overloaded flag to avoid any confusion when
2991 -- reanalyzing the node.
2993 Set_Is_Overloaded (N, False);
2995 -- Freeze expression type, entity if it is a name, and designated
2996 -- type if it is an allocator (RM 13.14(10,11,13)).
2998 -- Now that the resolution of the type of the node is complete, and
2999 -- we did not detect an error, we can expand this node. We skip the
3000 -- expand call if we are in a default expression, see section
3001 -- "Handling of Default Expressions" in Sem spec.
3003 Debug_A_Exit ("resolving ", N, " (done)");
3005 -- We unconditionally freeze the expression, even if we are in
3006 -- default expression mode (the Freeze_Expression routine tests this
3007 -- flag and only freezes static types if it is set).
3009 -- Ada 2012 (AI05-177): The declaration of an expression function
3010 -- does not cause freezing, but we never reach here in that case.
3011 -- Here we are resolving the corresponding expanded body, so we do
3012 -- need to perform normal freezing.
3014 Freeze_Expression (N);
3016 -- Now we can do the expansion
3021 Ghost_Mode := Save_Ghost_Mode;
3028 -- Version with check(s) suppressed
3030 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3032 if Suppress = All_Checks then
3034 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3036 Scope_Suppress.Suppress := (others => True);
3038 Scope_Suppress.Suppress := Sva;
3043 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3045 Scope_Suppress.Suppress (Suppress) := True;
3047 Scope_Suppress.Suppress (Suppress) := Svg;
3056 -- Version with implicit type
3058 procedure Resolve (N : Node_Id) is
3060 Resolve (N, Etype (N));
3063 ---------------------
3064 -- Resolve_Actuals --
3065 ---------------------
3067 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3068 Loc : constant Source_Ptr := Sloc (N);
3074 Prev : Node_Id := Empty;
3078 Real_Subp : Entity_Id;
3079 -- If the subprogram being called is an inherited operation for
3080 -- a formal derived type in an instance, Real_Subp is the subprogram
3081 -- that will be called. It may have different formal names than the
3082 -- operation of the formal in the generic, so after actual is resolved
3083 -- the name of the actual in a named association must carry the name
3084 -- of the actual of the subprogram being called.
3086 procedure Check_Aliased_Parameter;
3087 -- Check rules on aliased parameters and related accessibility rules
3088 -- in (RM 3.10.2 (10.2-10.4)).
3090 procedure Check_Argument_Order;
3091 -- Performs a check for the case where the actuals are all simple
3092 -- identifiers that correspond to the formal names, but in the wrong
3093 -- order, which is considered suspicious and cause for a warning.
3095 procedure Check_Prefixed_Call;
3096 -- If the original node is an overloaded call in prefix notation,
3097 -- insert an 'Access or a dereference as needed over the first actual.
3098 -- Try_Object_Operation has already verified that there is a valid
3099 -- interpretation, but the form of the actual can only be determined
3100 -- once the primitive operation is identified.
3102 procedure Insert_Default;
3103 -- If the actual is missing in a call, insert in the actuals list
3104 -- an instance of the default expression. The insertion is always
3105 -- a named association.
3107 procedure Property_Error
3110 Prop_Nam : Name_Id);
3111 -- Emit an error concerning variable Var with entity Var_Id that has
3112 -- enabled property Prop_Nam when it acts as an actual parameter in a
3113 -- call and the corresponding formal parameter is of mode IN.
3115 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3116 -- Check whether T1 and T2, or their full views, are derived from a
3117 -- common type. Used to enforce the restrictions on array conversions
3120 function Static_Concatenation (N : Node_Id) return Boolean;
3121 -- Predicate to determine whether an actual that is a concatenation
3122 -- will be evaluated statically and does not need a transient scope.
3123 -- This must be determined before the actual is resolved and expanded
3124 -- because if needed the transient scope must be introduced earlier.
3126 -----------------------------
3127 -- Check_Aliased_Parameter --
3128 -----------------------------
3130 procedure Check_Aliased_Parameter is
3131 Nominal_Subt : Entity_Id;
3134 if Is_Aliased (F) then
3135 if Is_Tagged_Type (A_Typ) then
3138 elsif Is_Aliased_View (A) then
3139 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3140 Nominal_Subt := Base_Type (A_Typ);
3142 Nominal_Subt := A_Typ;
3145 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3148 -- In a generic body assume the worst for generic formals:
3149 -- they can have a constrained partial view (AI05-041).
3151 elsif Has_Discriminants (F_Typ)
3152 and then not Is_Constrained (F_Typ)
3153 and then not Has_Constrained_Partial_View (F_Typ)
3154 and then not Is_Generic_Type (F_Typ)
3159 Error_Msg_NE ("untagged actual does not match "
3160 & "aliased formal&", A, F);
3164 Error_Msg_NE ("actual for aliased formal& must be "
3165 & "aliased object", A, F);
3168 if Ekind (Nam) = E_Procedure then
3171 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3172 if Nkind (Parent (N)) = N_Type_Conversion
3173 and then Type_Access_Level (Etype (Parent (N))) <
3174 Object_Access_Level (A)
3176 Error_Msg_N ("aliased actual has wrong accessibility", A);
3179 elsif Nkind (Parent (N)) = N_Qualified_Expression
3180 and then Nkind (Parent (Parent (N))) = N_Allocator
3181 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3182 Object_Access_Level (A)
3185 ("aliased actual in allocator has wrong accessibility", A);
3188 end Check_Aliased_Parameter;
3190 --------------------------
3191 -- Check_Argument_Order --
3192 --------------------------
3194 procedure Check_Argument_Order is
3196 -- Nothing to do if no parameters, or original node is neither a
3197 -- function call nor a procedure call statement (happens in the
3198 -- operator-transformed-to-function call case), or the call does
3199 -- not come from source, or this warning is off.
3201 if not Warn_On_Parameter_Order
3202 or else No (Parameter_Associations (N))
3203 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3204 or else not Comes_From_Source (N)
3210 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3213 -- Nothing to do if only one parameter
3219 -- Here if at least two arguments
3222 Actuals : array (1 .. Nargs) of Node_Id;
3226 Wrong_Order : Boolean := False;
3227 -- Set True if an out of order case is found
3230 -- Collect identifier names of actuals, fail if any actual is
3231 -- not a simple identifier, and record max length of name.
3233 Actual := First (Parameter_Associations (N));
3234 for J in Actuals'Range loop
3235 if Nkind (Actual) /= N_Identifier then
3238 Actuals (J) := Actual;
3243 -- If we got this far, all actuals are identifiers and the list
3244 -- of their names is stored in the Actuals array.
3246 Formal := First_Formal (Nam);
3247 for J in Actuals'Range loop
3249 -- If we ran out of formals, that's odd, probably an error
3250 -- which will be detected elsewhere, but abandon the search.
3256 -- If name matches and is in order OK
3258 if Chars (Formal) = Chars (Actuals (J)) then
3262 -- If no match, see if it is elsewhere in list and if so
3263 -- flag potential wrong order if type is compatible.
3265 for K in Actuals'Range loop
3266 if Chars (Formal) = Chars (Actuals (K))
3268 Has_Compatible_Type (Actuals (K), Etype (Formal))
3270 Wrong_Order := True;
3280 <<Continue>> Next_Formal (Formal);
3283 -- If Formals left over, also probably an error, skip warning
3285 if Present (Formal) then
3289 -- Here we give the warning if something was out of order
3293 ("?P?actuals for this call may be in wrong order", N);
3297 end Check_Argument_Order;
3299 -------------------------
3300 -- Check_Prefixed_Call --
3301 -------------------------
3303 procedure Check_Prefixed_Call is
3304 Act : constant Node_Id := First_Actual (N);
3305 A_Type : constant Entity_Id := Etype (Act);
3306 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3307 Orig : constant Node_Id := Original_Node (N);
3311 -- Check whether the call is a prefixed call, with or without
3312 -- additional actuals.
3314 if Nkind (Orig) = N_Selected_Component
3316 (Nkind (Orig) = N_Indexed_Component
3317 and then Nkind (Prefix (Orig)) = N_Selected_Component
3318 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3319 and then Is_Entity_Name (Act)
3320 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3322 if Is_Access_Type (A_Type)
3323 and then not Is_Access_Type (F_Type)
3325 -- Introduce dereference on object in prefix
3328 Make_Explicit_Dereference (Sloc (Act),
3329 Prefix => Relocate_Node (Act));
3330 Rewrite (Act, New_A);
3333 elsif Is_Access_Type (F_Type)
3334 and then not Is_Access_Type (A_Type)
3336 -- Introduce an implicit 'Access in prefix
3338 if not Is_Aliased_View (Act) then
3340 ("object in prefixed call to& must be aliased "
3341 & "(RM 4.1.3 (13 1/2))",
3346 Make_Attribute_Reference (Loc,
3347 Attribute_Name => Name_Access,
3348 Prefix => Relocate_Node (Act)));
3353 end Check_Prefixed_Call;
3355 --------------------
3356 -- Insert_Default --
3357 --------------------
3359 procedure Insert_Default is
3364 -- Missing argument in call, nothing to insert
3366 if No (Default_Value (F)) then
3370 -- Note that we do a full New_Copy_Tree, so that any associated
3371 -- Itypes are properly copied. This may not be needed any more,
3372 -- but it does no harm as a safety measure. Defaults of a generic
3373 -- formal may be out of bounds of the corresponding actual (see
3374 -- cc1311b) and an additional check may be required.
3379 New_Scope => Current_Scope,
3382 if Is_Concurrent_Type (Scope (Nam))
3383 and then Has_Discriminants (Scope (Nam))
3385 Replace_Actual_Discriminants (N, Actval);
3388 if Is_Overloadable (Nam)
3389 and then Present (Alias (Nam))
3391 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3392 and then not Is_Tagged_Type (Etype (F))
3394 -- If default is a real literal, do not introduce a
3395 -- conversion whose effect may depend on the run-time
3396 -- size of universal real.
3398 if Nkind (Actval) = N_Real_Literal then
3399 Set_Etype (Actval, Base_Type (Etype (F)));
3401 Actval := Unchecked_Convert_To (Etype (F), Actval);
3405 if Is_Scalar_Type (Etype (F)) then
3406 Enable_Range_Check (Actval);
3409 Set_Parent (Actval, N);
3411 -- Resolve aggregates with their base type, to avoid scope
3412 -- anomalies: the subtype was first built in the subprogram
3413 -- declaration, and the current call may be nested.
3415 if Nkind (Actval) = N_Aggregate then
3416 Analyze_And_Resolve (Actval, Etype (F));
3418 Analyze_And_Resolve (Actval, Etype (Actval));
3422 Set_Parent (Actval, N);
3424 -- See note above concerning aggregates
3426 if Nkind (Actval) = N_Aggregate
3427 and then Has_Discriminants (Etype (Actval))
3429 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3431 -- Resolve entities with their own type, which may differ from
3432 -- the type of a reference in a generic context (the view
3433 -- swapping mechanism did not anticipate the re-analysis of
3434 -- default values in calls).
3436 elsif Is_Entity_Name (Actval) then
3437 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3440 Analyze_And_Resolve (Actval, Etype (Actval));
3444 -- If default is a tag indeterminate function call, propagate tag
3445 -- to obtain proper dispatching.
3447 if Is_Controlling_Formal (F)
3448 and then Nkind (Default_Value (F)) = N_Function_Call
3450 Set_Is_Controlling_Actual (Actval);
3455 -- If the default expression raises constraint error, then just
3456 -- silently replace it with an N_Raise_Constraint_Error node, since
3457 -- we already gave the warning on the subprogram spec. If node is
3458 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3459 -- the warnings removal machinery.
3461 if Raises_Constraint_Error (Actval)
3462 and then Nkind (Actval) /= N_Raise_Constraint_Error
3465 Make_Raise_Constraint_Error (Loc,
3466 Reason => CE_Range_Check_Failed));
3467 Set_Raises_Constraint_Error (Actval);
3468 Set_Etype (Actval, Etype (F));
3472 Make_Parameter_Association (Loc,
3473 Explicit_Actual_Parameter => Actval,
3474 Selector_Name => Make_Identifier (Loc, Chars (F)));
3476 -- Case of insertion is first named actual
3478 if No (Prev) or else
3479 Nkind (Parent (Prev)) /= N_Parameter_Association
3481 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3482 Set_First_Named_Actual (N, Actval);
3485 if No (Parameter_Associations (N)) then
3486 Set_Parameter_Associations (N, New_List (Assoc));
3488 Append (Assoc, Parameter_Associations (N));
3492 Insert_After (Prev, Assoc);
3495 -- Case of insertion is not first named actual
3498 Set_Next_Named_Actual
3499 (Assoc, Next_Named_Actual (Parent (Prev)));
3500 Set_Next_Named_Actual (Parent (Prev), Actval);
3501 Append (Assoc, Parameter_Associations (N));
3504 Mark_Rewrite_Insertion (Assoc);
3505 Mark_Rewrite_Insertion (Actval);
3510 --------------------
3511 -- Property_Error --
3512 --------------------
3514 procedure Property_Error
3520 Error_Msg_Name_1 := Prop_Nam;
3522 ("external variable & with enabled property % cannot appear as "
3523 & "actual in procedure call (SPARK RM 7.1.3(11))", Var, Var_Id);
3524 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3531 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3532 FT1 : Entity_Id := T1;
3533 FT2 : Entity_Id := T2;
3536 if Is_Private_Type (T1)
3537 and then Present (Full_View (T1))
3539 FT1 := Full_View (T1);
3542 if Is_Private_Type (T2)
3543 and then Present (Full_View (T2))
3545 FT2 := Full_View (T2);
3548 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3551 --------------------------
3552 -- Static_Concatenation --
3553 --------------------------
3555 function Static_Concatenation (N : Node_Id) return Boolean is
3558 when N_String_Literal =>
3563 -- Concatenation is static when both operands are static and
3564 -- the concatenation operator is a predefined one.
3566 return Scope (Entity (N)) = Standard_Standard
3568 Static_Concatenation (Left_Opnd (N))
3570 Static_Concatenation (Right_Opnd (N));
3573 if Is_Entity_Name (N) then
3575 Ent : constant Entity_Id := Entity (N);
3577 return Ekind (Ent) = E_Constant
3578 and then Present (Constant_Value (Ent))
3580 Is_OK_Static_Expression (Constant_Value (Ent));
3587 end Static_Concatenation;
3589 -- Start of processing for Resolve_Actuals
3592 Check_Argument_Order;
3594 if Is_Overloadable (Nam)
3595 and then Is_Inherited_Operation (Nam)
3596 and then In_Instance
3597 and then Present (Alias (Nam))
3598 and then Present (Overridden_Operation (Alias (Nam)))
3600 Real_Subp := Alias (Nam);
3605 if Present (First_Actual (N)) then
3606 Check_Prefixed_Call;
3609 A := First_Actual (N);
3610 F := First_Formal (Nam);
3612 if Present (Real_Subp) then
3613 Real_F := First_Formal (Real_Subp);
3616 while Present (F) loop
3617 if No (A) and then Needs_No_Actuals (Nam) then
3620 -- If we have an error in any actual or formal, indicated by a type
3621 -- of Any_Type, then abandon resolution attempt, and set result type
3622 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3623 -- type is imposed from context.
3625 elsif (Present (A) and then Etype (A) = Any_Type)
3626 or else Etype (F) = Any_Type
3628 if Nkind (A) /= N_Raise_Expression then
3629 Set_Etype (N, Any_Type);
3634 -- Case where actual is present
3636 -- If the actual is an entity, generate a reference to it now. We
3637 -- do this before the actual is resolved, because a formal of some
3638 -- protected subprogram, or a task discriminant, will be rewritten
3639 -- during expansion, and the source entity reference may be lost.
3642 and then Is_Entity_Name (A)
3643 and then Comes_From_Source (N)
3645 Orig_A := Entity (A);
3647 if Present (Orig_A) then
3648 if Is_Formal (Orig_A)
3649 and then Ekind (F) /= E_In_Parameter
3651 Generate_Reference (Orig_A, A, 'm');
3653 elsif not Is_Overloaded (A) then
3654 if Ekind (F) /= E_Out_Parameter then
3655 Generate_Reference (Orig_A, A);
3657 -- RM 6.4.1(12): For an out parameter that is passed by
3658 -- copy, the formal parameter object is created, and:
3660 -- * For an access type, the formal parameter is initialized
3661 -- from the value of the actual, without checking that the
3662 -- value satisfies any constraint, any predicate, or any
3663 -- exclusion of the null value.
3665 -- * For a scalar type that has the Default_Value aspect
3666 -- specified, the formal parameter is initialized from the
3667 -- value of the actual, without checking that the value
3668 -- satisfies any constraint or any predicate.
3669 -- I do not understand why this case is included??? this is
3670 -- not a case where an OUT parameter is treated as IN OUT.
3672 -- * For a composite type with discriminants or that has
3673 -- implicit initial values for any subcomponents, the
3674 -- behavior is as for an in out parameter passed by copy.
3676 -- Hence for these cases we generate the read reference now
3677 -- (the write reference will be generated later by
3678 -- Note_Possible_Modification).
3680 elsif Is_By_Copy_Type (Etype (F))
3682 (Is_Access_Type (Etype (F))
3684 (Is_Scalar_Type (Etype (F))
3686 Present (Default_Aspect_Value (Etype (F))))
3688 (Is_Composite_Type (Etype (F))
3689 and then (Has_Discriminants (Etype (F))
3690 or else Is_Partially_Initialized_Type
3693 Generate_Reference (Orig_A, A);
3700 and then (Nkind (Parent (A)) /= N_Parameter_Association
3701 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3703 -- If style checking mode on, check match of formal name
3706 if Nkind (Parent (A)) = N_Parameter_Association then
3707 Check_Identifier (Selector_Name (Parent (A)), F);
3711 -- If the formal is Out or In_Out, do not resolve and expand the
3712 -- conversion, because it is subsequently expanded into explicit
3713 -- temporaries and assignments. However, the object of the
3714 -- conversion can be resolved. An exception is the case of tagged
3715 -- type conversion with a class-wide actual. In that case we want
3716 -- the tag check to occur and no temporary will be needed (no
3717 -- representation change can occur) and the parameter is passed by
3718 -- reference, so we go ahead and resolve the type conversion.
3719 -- Another exception is the case of reference to component or
3720 -- subcomponent of a bit-packed array, in which case we want to
3721 -- defer expansion to the point the in and out assignments are
3724 if Ekind (F) /= E_In_Parameter
3725 and then Nkind (A) = N_Type_Conversion
3726 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3728 if Ekind (F) = E_In_Out_Parameter
3729 and then Is_Array_Type (Etype (F))
3731 -- In a view conversion, the conversion must be legal in
3732 -- both directions, and thus both component types must be
3733 -- aliased, or neither (4.6 (8)).
3735 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3736 -- the privacy requirement should not apply to generic
3737 -- types, and should be checked in an instance. ARG query
3740 if Has_Aliased_Components (Etype (Expression (A))) /=
3741 Has_Aliased_Components (Etype (F))
3744 ("both component types in a view conversion must be"
3745 & " aliased, or neither", A);
3747 -- Comment here??? what set of cases???
3750 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3752 -- Check view conv between unrelated by ref array types
3754 if Is_By_Reference_Type (Etype (F))
3755 or else Is_By_Reference_Type (Etype (Expression (A)))
3758 ("view conversion between unrelated by reference "
3759 & "array types not allowed (\'A'I-00246)", A);
3761 -- In Ada 2005 mode, check view conversion component
3762 -- type cannot be private, tagged, or volatile. Note
3763 -- that we only apply this to source conversions. The
3764 -- generated code can contain conversions which are
3765 -- not subject to this test, and we cannot extract the
3766 -- component type in such cases since it is not present.
3768 elsif Comes_From_Source (A)
3769 and then Ada_Version >= Ada_2005
3772 Comp_Type : constant Entity_Id :=
3774 (Etype (Expression (A)));
3776 if (Is_Private_Type (Comp_Type)
3777 and then not Is_Generic_Type (Comp_Type))
3778 or else Is_Tagged_Type (Comp_Type)
3779 or else Is_Volatile (Comp_Type)
3782 ("component type of a view conversion cannot"
3783 & " be private, tagged, or volatile"
3792 -- Resolve expression if conversion is all OK
3794 if (Conversion_OK (A)
3795 or else Valid_Conversion (A, Etype (A), Expression (A)))
3796 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3798 Resolve (Expression (A));
3801 -- If the actual is a function call that returns a limited
3802 -- unconstrained object that needs finalization, create a
3803 -- transient scope for it, so that it can receive the proper
3804 -- finalization list.
3806 elsif Nkind (A) = N_Function_Call
3807 and then Is_Limited_Record (Etype (F))
3808 and then not Is_Constrained (Etype (F))
3809 and then Expander_Active
3810 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3812 Establish_Transient_Scope (A, Sec_Stack => False);
3813 Resolve (A, Etype (F));
3815 -- A small optimization: if one of the actuals is a concatenation
3816 -- create a block around a procedure call to recover stack space.
3817 -- This alleviates stack usage when several procedure calls in
3818 -- the same statement list use concatenation. We do not perform
3819 -- this wrapping for code statements, where the argument is a
3820 -- static string, and we want to preserve warnings involving
3821 -- sequences of such statements.
3823 elsif Nkind (A) = N_Op_Concat
3824 and then Nkind (N) = N_Procedure_Call_Statement
3825 and then Expander_Active
3827 not (Is_Intrinsic_Subprogram (Nam)
3828 and then Chars (Nam) = Name_Asm)
3829 and then not Static_Concatenation (A)
3831 Establish_Transient_Scope (A, Sec_Stack => False);
3832 Resolve (A, Etype (F));
3835 if Nkind (A) = N_Type_Conversion
3836 and then Is_Array_Type (Etype (F))
3837 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3839 (Is_Limited_Type (Etype (F))
3840 or else Is_Limited_Type (Etype (Expression (A))))
3843 ("conversion between unrelated limited array types "
3844 & "not allowed ('A'I-00246)", A);
3846 if Is_Limited_Type (Etype (F)) then
3847 Explain_Limited_Type (Etype (F), A);
3850 if Is_Limited_Type (Etype (Expression (A))) then
3851 Explain_Limited_Type (Etype (Expression (A)), A);
3855 -- (Ada 2005: AI-251): If the actual is an allocator whose
3856 -- directly designated type is a class-wide interface, we build
3857 -- an anonymous access type to use it as the type of the
3858 -- allocator. Later, when the subprogram call is expanded, if
3859 -- the interface has a secondary dispatch table the expander
3860 -- will add a type conversion to force the correct displacement
3863 if Nkind (A) = N_Allocator then
3865 DDT : constant Entity_Id :=
3866 Directly_Designated_Type (Base_Type (Etype (F)));
3868 New_Itype : Entity_Id;
3871 if Is_Class_Wide_Type (DDT)
3872 and then Is_Interface (DDT)
3874 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3875 Set_Etype (New_Itype, Etype (A));
3876 Set_Directly_Designated_Type
3877 (New_Itype, Directly_Designated_Type (Etype (A)));
3878 Set_Etype (A, New_Itype);
3881 -- Ada 2005, AI-162:If the actual is an allocator, the
3882 -- innermost enclosing statement is the master of the
3883 -- created object. This needs to be done with expansion
3884 -- enabled only, otherwise the transient scope will not
3885 -- be removed in the expansion of the wrapped construct.
3887 if (Is_Controlled (DDT) or else Has_Task (DDT))
3888 and then Expander_Active
3890 Establish_Transient_Scope (A, Sec_Stack => False);
3894 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3895 Check_Restriction (No_Access_Parameter_Allocators, A);
3899 -- (Ada 2005): The call may be to a primitive operation of a
3900 -- tagged synchronized type, declared outside of the type. In
3901 -- this case the controlling actual must be converted to its
3902 -- corresponding record type, which is the formal type. The
3903 -- actual may be a subtype, either because of a constraint or
3904 -- because it is a generic actual, so use base type to locate
3907 F_Typ := Base_Type (Etype (F));
3909 if Is_Tagged_Type (F_Typ)
3910 and then (Is_Concurrent_Type (F_Typ)
3911 or else Is_Concurrent_Record_Type (F_Typ))
3913 -- If the actual is overloaded, look for an interpretation
3914 -- that has a synchronized type.
3916 if not Is_Overloaded (A) then
3917 A_Typ := Base_Type (Etype (A));
3921 Index : Interp_Index;
3925 Get_First_Interp (A, Index, It);
3926 while Present (It.Typ) loop
3927 if Is_Concurrent_Type (It.Typ)
3928 or else Is_Concurrent_Record_Type (It.Typ)
3930 A_Typ := Base_Type (It.Typ);
3934 Get_Next_Interp (Index, It);
3940 Full_A_Typ : Entity_Id;
3943 if Present (Full_View (A_Typ)) then
3944 Full_A_Typ := Base_Type (Full_View (A_Typ));
3946 Full_A_Typ := A_Typ;
3949 -- Tagged synchronized type (case 1): the actual is a
3952 if Is_Concurrent_Type (A_Typ)
3953 and then Corresponding_Record_Type (A_Typ) = F_Typ
3956 Unchecked_Convert_To
3957 (Corresponding_Record_Type (A_Typ), A));
3958 Resolve (A, Etype (F));
3960 -- Tagged synchronized type (case 2): the formal is a
3963 elsif Ekind (Full_A_Typ) = E_Record_Type
3965 (Corresponding_Concurrent_Type (Full_A_Typ))
3966 and then Is_Concurrent_Type (F_Typ)
3967 and then Present (Corresponding_Record_Type (F_Typ))
3968 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3970 Resolve (A, Corresponding_Record_Type (F_Typ));
3975 Resolve (A, Etype (F));
3979 -- Not a synchronized operation
3982 Resolve (A, Etype (F));
3989 -- An actual cannot be an untagged formal incomplete type
3991 if Ekind (A_Typ) = E_Incomplete_Type
3992 and then not Is_Tagged_Type (A_Typ)
3993 and then Is_Generic_Type (A_Typ)
3996 ("invalid use of untagged formal incomplete type", A);
3999 if Comes_From_Source (Original_Node (N))
4000 and then Nkind_In (Original_Node (N), N_Function_Call,
4001 N_Procedure_Call_Statement)
4003 -- In formal mode, check that actual parameters matching
4004 -- formals of tagged types are objects (or ancestor type
4005 -- conversions of objects), not general expressions.
4007 if Is_Actual_Tagged_Parameter (A) then
4008 if Is_SPARK_05_Object_Reference (A) then
4011 elsif Nkind (A) = N_Type_Conversion then
4013 Operand : constant Node_Id := Expression (A);
4014 Operand_Typ : constant Entity_Id := Etype (Operand);
4015 Target_Typ : constant Entity_Id := A_Typ;
4018 if not Is_SPARK_05_Object_Reference (Operand) then
4019 Check_SPARK_05_Restriction
4020 ("object required", Operand);
4022 -- In formal mode, the only view conversions are those
4023 -- involving ancestor conversion of an extended type.
4026 (Is_Tagged_Type (Target_Typ)
4027 and then not Is_Class_Wide_Type (Target_Typ)
4028 and then Is_Tagged_Type (Operand_Typ)
4029 and then not Is_Class_Wide_Type (Operand_Typ)
4030 and then Is_Ancestor (Target_Typ, Operand_Typ))
4033 (F, E_Out_Parameter, E_In_Out_Parameter)
4035 Check_SPARK_05_Restriction
4036 ("ancestor conversion is the only permitted "
4037 & "view conversion", A);
4039 Check_SPARK_05_Restriction
4040 ("ancestor conversion required", A);
4049 Check_SPARK_05_Restriction ("object required", A);
4052 -- In formal mode, the only view conversions are those
4053 -- involving ancestor conversion of an extended type.
4055 elsif Nkind (A) = N_Type_Conversion
4056 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4058 Check_SPARK_05_Restriction
4059 ("ancestor conversion is the only permitted view "
4064 -- has warnings suppressed, then we reset Never_Set_In_Source for
4065 -- the calling entity. The reason for this is to catch cases like
4066 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4067 -- uses trickery to modify an IN parameter.
4069 if Ekind (F) = E_In_Parameter
4070 and then Is_Entity_Name (A)
4071 and then Present (Entity (A))
4072 and then Ekind (Entity (A)) = E_Variable
4073 and then Has_Warnings_Off (F_Typ)
4075 Set_Never_Set_In_Source (Entity (A), False);
4078 -- Perform error checks for IN and IN OUT parameters
4080 if Ekind (F) /= E_Out_Parameter then
4082 -- Check unset reference. For scalar parameters, it is clearly
4083 -- wrong to pass an uninitialized value as either an IN or
4084 -- IN-OUT parameter. For composites, it is also clearly an
4085 -- error to pass a completely uninitialized value as an IN
4086 -- parameter, but the case of IN OUT is trickier. We prefer
4087 -- not to give a warning here. For example, suppose there is
4088 -- a routine that sets some component of a record to False.
4089 -- It is perfectly reasonable to make this IN-OUT and allow
4090 -- either initialized or uninitialized records to be passed
4093 -- For partially initialized composite values, we also avoid
4094 -- warnings, since it is quite likely that we are passing a
4095 -- partially initialized value and only the initialized fields
4096 -- will in fact be read in the subprogram.
4098 if Is_Scalar_Type (A_Typ)
4099 or else (Ekind (F) = E_In_Parameter
4100 and then not Is_Partially_Initialized_Type (A_Typ))
4102 Check_Unset_Reference (A);
4105 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4106 -- actual to a nested call, since this constitutes a reading of
4107 -- the parameter, which is not allowed.
4109 if Ada_Version = Ada_83
4110 and then Is_Entity_Name (A)
4111 and then Ekind (Entity (A)) = E_Out_Parameter
4113 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4117 -- Case of OUT or IN OUT parameter
4119 if Ekind (F) /= E_In_Parameter then
4121 -- For an Out parameter, check for useless assignment. Note
4122 -- that we can't set Last_Assignment this early, because we may
4123 -- kill current values in Resolve_Call, and that call would
4124 -- clobber the Last_Assignment field.
4126 -- Note: call Warn_On_Useless_Assignment before doing the check
4127 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4128 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4129 -- reflects the last assignment, not this one.
4131 if Ekind (F) = E_Out_Parameter then
4132 if Warn_On_Modified_As_Out_Parameter (F)
4133 and then Is_Entity_Name (A)
4134 and then Present (Entity (A))
4135 and then Comes_From_Source (N)
4137 Warn_On_Useless_Assignment (Entity (A), A);
4141 -- Validate the form of the actual. Note that the call to
4142 -- Is_OK_Variable_For_Out_Formal generates the required
4143 -- reference in this case.
4145 -- A call to an initialization procedure for an aggregate
4146 -- component may initialize a nested component of a constant
4147 -- designated object. In this context the object is variable.
4149 if not Is_OK_Variable_For_Out_Formal (A)
4150 and then not Is_Init_Proc (Nam)
4152 Error_Msg_NE ("actual for& must be a variable", A, F);
4154 if Is_Subprogram (Current_Scope)
4156 (Is_Invariant_Procedure (Current_Scope)
4157 or else Is_Predicate_Function (Current_Scope))
4160 ("function used in predicate cannot "
4161 & "modify its argument", F);
4165 -- What's the following about???
4167 if Is_Entity_Name (A) then
4168 Kill_Checks (Entity (A));
4174 if Etype (A) = Any_Type then
4175 Set_Etype (N, Any_Type);
4179 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4181 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4183 -- Apply predicate tests except in certain special cases. Note
4184 -- that it might be more consistent to apply these only when
4185 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4186 -- for the outbound predicate tests ???
4188 if Predicate_Tests_On_Arguments (Nam) then
4189 Apply_Predicate_Check (A, F_Typ);
4192 -- Apply required constraint checks
4194 -- Gigi looks at the check flag and uses the appropriate types.
4195 -- For now since one flag is used there is an optimization
4196 -- which might not be done in the IN OUT case since Gigi does
4197 -- not do any analysis. More thought required about this ???
4199 -- In fact is this comment obsolete??? doesn't the expander now
4200 -- generate all these tests anyway???
4202 if Is_Scalar_Type (Etype (A)) then
4203 Apply_Scalar_Range_Check (A, F_Typ);
4205 elsif Is_Array_Type (Etype (A)) then
4206 Apply_Length_Check (A, F_Typ);
4208 elsif Is_Record_Type (F_Typ)
4209 and then Has_Discriminants (F_Typ)
4210 and then Is_Constrained (F_Typ)
4211 and then (not Is_Derived_Type (F_Typ)
4212 or else Comes_From_Source (Nam))
4214 Apply_Discriminant_Check (A, F_Typ);
4216 -- For view conversions of a discriminated object, apply
4217 -- check to object itself, the conversion alreay has the
4220 if Nkind (A) = N_Type_Conversion
4221 and then Is_Constrained (Etype (Expression (A)))
4223 Apply_Discriminant_Check (Expression (A), F_Typ);
4226 elsif Is_Access_Type (F_Typ)
4227 and then Is_Array_Type (Designated_Type (F_Typ))
4228 and then Is_Constrained (Designated_Type (F_Typ))
4230 Apply_Length_Check (A, F_Typ);
4232 elsif Is_Access_Type (F_Typ)
4233 and then Has_Discriminants (Designated_Type (F_Typ))
4234 and then Is_Constrained (Designated_Type (F_Typ))
4236 Apply_Discriminant_Check (A, F_Typ);
4239 Apply_Range_Check (A, F_Typ);
4242 -- Ada 2005 (AI-231): Note that the controlling parameter case
4243 -- already existed in Ada 95, which is partially checked
4244 -- elsewhere (see Checks), and we don't want the warning
4245 -- message to differ.
4247 if Is_Access_Type (F_Typ)
4248 and then Can_Never_Be_Null (F_Typ)
4249 and then Known_Null (A)
4251 if Is_Controlling_Formal (F) then
4252 Apply_Compile_Time_Constraint_Error
4254 Msg => "null value not allowed here??",
4255 Reason => CE_Access_Check_Failed);
4257 elsif Ada_Version >= Ada_2005 then
4258 Apply_Compile_Time_Constraint_Error
4260 Msg => "(Ada 2005) null not allowed in "
4261 & "null-excluding formal??",
4262 Reason => CE_Null_Not_Allowed);
4267 -- Checks for OUT parameters and IN OUT parameters
4269 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4271 -- If there is a type conversion, to make sure the return value
4272 -- meets the constraints of the variable before the conversion.
4274 if Nkind (A) = N_Type_Conversion then
4275 if Is_Scalar_Type (A_Typ) then
4276 Apply_Scalar_Range_Check
4277 (Expression (A), Etype (Expression (A)), A_Typ);
4280 (Expression (A), Etype (Expression (A)), A_Typ);
4283 -- If no conversion apply scalar range checks and length checks
4284 -- base on the subtype of the actual (NOT that of the formal).
4287 if Is_Scalar_Type (F_Typ) then
4288 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4289 elsif Is_Array_Type (F_Typ)
4290 and then Ekind (F) = E_Out_Parameter
4292 Apply_Length_Check (A, F_Typ);
4294 Apply_Range_Check (A, A_Typ, F_Typ);
4298 -- Note: we do not apply the predicate checks for the case of
4299 -- OUT and IN OUT parameters. They are instead applied in the
4300 -- Expand_Actuals routine in Exp_Ch6.
4303 -- An actual associated with an access parameter is implicitly
4304 -- converted to the anonymous access type of the formal and must
4305 -- satisfy the legality checks for access conversions.
4307 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4308 if not Valid_Conversion (A, F_Typ, A) then
4310 ("invalid implicit conversion for access parameter", A);
4313 -- If the actual is an access selected component of a variable,
4314 -- the call may modify its designated object. It is reasonable
4315 -- to treat this as a potential modification of the enclosing
4316 -- record, to prevent spurious warnings that it should be
4317 -- declared as a constant, because intuitively programmers
4318 -- regard the designated subcomponent as part of the record.
4320 if Nkind (A) = N_Selected_Component
4321 and then Is_Entity_Name (Prefix (A))
4322 and then not Is_Constant_Object (Entity (Prefix (A)))
4324 Note_Possible_Modification (A, Sure => False);
4328 -- Check bad case of atomic/volatile argument (RM C.6(12))
4330 if Is_By_Reference_Type (Etype (F))
4331 and then Comes_From_Source (N)
4333 if Is_Atomic_Object (A)
4334 and then not Is_Atomic (Etype (F))
4337 ("cannot pass atomic argument to non-atomic formal&",
4340 elsif Is_Volatile_Object (A)
4341 and then not Is_Volatile (Etype (F))
4344 ("cannot pass volatile argument to non-volatile formal&",
4349 -- Check that subprograms don't have improper controlling
4350 -- arguments (RM 3.9.2 (9)).
4352 -- A primitive operation may have an access parameter of an
4353 -- incomplete tagged type, but a dispatching call is illegal
4354 -- if the type is still incomplete.
4356 if Is_Controlling_Formal (F) then
4357 Set_Is_Controlling_Actual (A);
4359 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4361 Desig : constant Entity_Id := Designated_Type (Etype (F));
4363 if Ekind (Desig) = E_Incomplete_Type
4364 and then No (Full_View (Desig))
4365 and then No (Non_Limited_View (Desig))
4368 ("premature use of incomplete type& "
4369 & "in dispatching call", A, Desig);
4374 elsif Nkind (A) = N_Explicit_Dereference then
4375 Validate_Remote_Access_To_Class_Wide_Type (A);
4378 -- Apply legality rule 3.9.2 (9/1)
4380 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4381 and then not Is_Class_Wide_Type (F_Typ)
4382 and then not Is_Controlling_Formal (F)
4383 and then not In_Instance
4385 Error_Msg_N ("class-wide argument not allowed here!", A);
4387 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4388 Error_Msg_Node_2 := F_Typ;
4390 ("& is not a dispatching operation of &!", A, Nam);
4393 -- Apply the checks described in 3.10.2(27): if the context is a
4394 -- specific access-to-object, the actual cannot be class-wide.
4395 -- Use base type to exclude access_to_subprogram cases.
4397 elsif Is_Access_Type (A_Typ)
4398 and then Is_Access_Type (F_Typ)
4399 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4400 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4401 or else (Nkind (A) = N_Attribute_Reference
4403 Is_Class_Wide_Type (Etype (Prefix (A)))))
4404 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4405 and then not Is_Controlling_Formal (F)
4407 -- Disable these checks for call to imported C++ subprograms
4410 (Is_Entity_Name (Name (N))
4411 and then Is_Imported (Entity (Name (N)))
4412 and then Convention (Entity (Name (N))) = Convention_CPP)
4415 ("access to class-wide argument not allowed here!", A);
4417 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4418 Error_Msg_Node_2 := Designated_Type (F_Typ);
4420 ("& is not a dispatching operation of &!", A, Nam);
4424 Check_Aliased_Parameter;
4428 -- If it is a named association, treat the selector_name as a
4429 -- proper identifier, and mark the corresponding entity.
4431 if Nkind (Parent (A)) = N_Parameter_Association
4433 -- Ignore reference in SPARK mode, as it refers to an entity not
4434 -- in scope at the point of reference, so the reference should
4435 -- be ignored for computing effects of subprograms.
4437 and then not GNATprove_Mode
4439 -- If subprogram is overridden, use name of formal that
4442 if Present (Real_Subp) then
4443 Set_Entity (Selector_Name (Parent (A)), Real_F);
4444 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4447 Set_Entity (Selector_Name (Parent (A)), F);
4448 Generate_Reference (F, Selector_Name (Parent (A)));
4449 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4450 Generate_Reference (F_Typ, N, ' ');
4456 if Ekind (F) /= E_Out_Parameter then
4457 Check_Unset_Reference (A);
4460 -- The following checks are only relevant when SPARK_Mode is on as
4461 -- they are not standard Ada legality rule. Internally generated
4462 -- temporaries are ignored.
4465 and then Comes_From_Source (A)
4466 and then Is_Effectively_Volatile_Object (A)
4468 -- An effectively volatile object may act as an actual when the
4469 -- corresponding formal is of a non-scalar effectively volatile
4470 -- type (SPARK RM 7.1.3(12)).
4472 if not Is_Scalar_Type (Etype (F))
4473 and then Is_Effectively_Volatile (Etype (F))
4477 -- An effectively volatile object may act as an actual in a
4478 -- call to an instance of Unchecked_Conversion.
4479 -- (SPARK RM 7.1.3(12)).
4481 elsif Is_Unchecked_Conversion_Instance (Nam) then
4486 ("volatile object cannot act as actual in a call (SPARK "
4487 & "RM 7.1.3(12))", A);
4490 -- Detect an external variable with an enabled property that
4491 -- does not match the mode of the corresponding formal in a
4492 -- procedure call. Functions are not considered because they
4493 -- cannot have effectively volatile formal parameters in the
4496 if Ekind (Nam) = E_Procedure
4497 and then Ekind (F) = E_In_Parameter
4498 and then Is_Entity_Name (A)
4499 and then Present (Entity (A))
4500 and then Ekind (Entity (A)) = E_Variable
4504 if Async_Readers_Enabled (A_Id) then
4505 Property_Error (A, A_Id, Name_Async_Readers);
4506 elsif Effective_Reads_Enabled (A_Id) then
4507 Property_Error (A, A_Id, Name_Effective_Reads);
4508 elsif Effective_Writes_Enabled (A_Id) then
4509 Property_Error (A, A_Id, Name_Effective_Writes);
4514 -- A formal parameter of a specific tagged type whose related
4515 -- subprogram is subject to pragma Extensions_Visible with value
4516 -- "False" cannot act as an actual in a subprogram with value
4517 -- "True" (SPARK RM 6.1.7(3)).
4519 if Is_EVF_Expression (A)
4520 and then Extensions_Visible_Status (Nam) =
4521 Extensions_Visible_True
4524 ("formal parameter with Extensions_Visible False cannot act "
4525 & "as actual parameter", A);
4527 ("\subprogram & has Extensions_Visible True", A, Nam);
4530 -- The actual parameter of a Ghost subprogram whose formal is of
4531 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(13)).
4533 if Comes_From_Source (Nam)
4534 and then Is_Ghost_Entity (Nam)
4535 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4536 and then Is_Entity_Name (A)
4537 and then Present (Entity (A))
4538 and then not Is_Ghost_Entity (Entity (A))
4541 ("non-ghost variable & cannot appear as actual in call to "
4542 & "ghost procedure", A, Entity (A));
4544 if Ekind (F) = E_In_Out_Parameter then
4545 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4547 Error_Msg_N ("\corresponding formal has mode OUT", A);
4553 -- Case where actual is not present
4561 if Present (Real_Subp) then
4562 Next_Formal (Real_F);
4565 end Resolve_Actuals;
4567 -----------------------
4568 -- Resolve_Allocator --
4569 -----------------------
4571 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4572 Desig_T : constant Entity_Id := Designated_Type (Typ);
4573 E : constant Node_Id := Expression (N);
4575 Discrim : Entity_Id;
4578 Assoc : Node_Id := Empty;
4581 procedure Check_Allocator_Discrim_Accessibility
4582 (Disc_Exp : Node_Id;
4583 Alloc_Typ : Entity_Id);
4584 -- Check that accessibility level associated with an access discriminant
4585 -- initialized in an allocator by the expression Disc_Exp is not deeper
4586 -- than the level of the allocator type Alloc_Typ. An error message is
4587 -- issued if this condition is violated. Specialized checks are done for
4588 -- the cases of a constraint expression which is an access attribute or
4589 -- an access discriminant.
4591 function In_Dispatching_Context return Boolean;
4592 -- If the allocator is an actual in a call, it is allowed to be class-
4593 -- wide when the context is not because it is a controlling actual.
4595 -------------------------------------------
4596 -- Check_Allocator_Discrim_Accessibility --
4597 -------------------------------------------
4599 procedure Check_Allocator_Discrim_Accessibility
4600 (Disc_Exp : Node_Id;
4601 Alloc_Typ : Entity_Id)
4604 if Type_Access_Level (Etype (Disc_Exp)) >
4605 Deepest_Type_Access_Level (Alloc_Typ)
4608 ("operand type has deeper level than allocator type", Disc_Exp);
4610 -- When the expression is an Access attribute the level of the prefix
4611 -- object must not be deeper than that of the allocator's type.
4613 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4614 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4616 and then Object_Access_Level (Prefix (Disc_Exp)) >
4617 Deepest_Type_Access_Level (Alloc_Typ)
4620 ("prefix of attribute has deeper level than allocator type",
4623 -- When the expression is an access discriminant the check is against
4624 -- the level of the prefix object.
4626 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4627 and then Nkind (Disc_Exp) = N_Selected_Component
4628 and then Object_Access_Level (Prefix (Disc_Exp)) >
4629 Deepest_Type_Access_Level (Alloc_Typ)
4632 ("access discriminant has deeper level than allocator type",
4635 -- All other cases are legal
4640 end Check_Allocator_Discrim_Accessibility;
4642 ----------------------------
4643 -- In_Dispatching_Context --
4644 ----------------------------
4646 function In_Dispatching_Context return Boolean is
4647 Par : constant Node_Id := Parent (N);
4650 return Nkind (Par) in N_Subprogram_Call
4651 and then Is_Entity_Name (Name (Par))
4652 and then Is_Dispatching_Operation (Entity (Name (Par)));
4653 end In_Dispatching_Context;
4655 -- Start of processing for Resolve_Allocator
4658 -- Replace general access with specific type
4660 if Ekind (Etype (N)) = E_Allocator_Type then
4661 Set_Etype (N, Base_Type (Typ));
4664 if Is_Abstract_Type (Typ) then
4665 Error_Msg_N ("type of allocator cannot be abstract", N);
4668 -- For qualified expression, resolve the expression using the given
4669 -- subtype (nothing to do for type mark, subtype indication)
4671 if Nkind (E) = N_Qualified_Expression then
4672 if Is_Class_Wide_Type (Etype (E))
4673 and then not Is_Class_Wide_Type (Desig_T)
4674 and then not In_Dispatching_Context
4677 ("class-wide allocator not allowed for this access type", N);
4680 Resolve (Expression (E), Etype (E));
4681 Check_Non_Static_Context (Expression (E));
4682 Check_Unset_Reference (Expression (E));
4684 -- Allocators generated by the build-in-place expansion mechanism
4685 -- are explicitly marked as coming from source but do not need to be
4686 -- checked for limited initialization. To exclude this case, ensure
4687 -- that the parent of the allocator is a source node.
4689 if Is_Limited_Type (Etype (E))
4690 and then Comes_From_Source (N)
4691 and then Comes_From_Source (Parent (N))
4692 and then not In_Instance_Body
4694 if not OK_For_Limited_Init (Etype (E), Expression (E)) then
4695 Error_Msg_N ("initialization not allowed for limited types", N);
4696 Explain_Limited_Type (Etype (E), N);
4700 -- A qualified expression requires an exact match of the type.
4701 -- Class-wide matching is not allowed.
4703 if (Is_Class_Wide_Type (Etype (Expression (E)))
4704 or else Is_Class_Wide_Type (Etype (E)))
4705 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4707 Wrong_Type (Expression (E), Etype (E));
4710 -- Calls to build-in-place functions are not currently supported in
4711 -- allocators for access types associated with a simple storage pool.
4712 -- Supporting such allocators may require passing additional implicit
4713 -- parameters to build-in-place functions (or a significant revision
4714 -- of the current b-i-p implementation to unify the handling for
4715 -- multiple kinds of storage pools). ???
4717 if Is_Limited_View (Desig_T)
4718 and then Nkind (Expression (E)) = N_Function_Call
4721 Pool : constant Entity_Id :=
4722 Associated_Storage_Pool (Root_Type (Typ));
4726 Present (Get_Rep_Pragma
4727 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4730 ("limited function calls not yet supported in simple "
4731 & "storage pool allocators", Expression (E));
4736 -- A special accessibility check is needed for allocators that
4737 -- constrain access discriminants. The level of the type of the
4738 -- expression used to constrain an access discriminant cannot be
4739 -- deeper than the type of the allocator (in contrast to access
4740 -- parameters, where the level of the actual can be arbitrary).
4742 -- We can't use Valid_Conversion to perform this check because in
4743 -- general the type of the allocator is unrelated to the type of
4744 -- the access discriminant.
4746 if Ekind (Typ) /= E_Anonymous_Access_Type
4747 or else Is_Local_Anonymous_Access (Typ)
4749 Subtyp := Entity (Subtype_Mark (E));
4751 Aggr := Original_Node (Expression (E));
4753 if Has_Discriminants (Subtyp)
4754 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4756 Discrim := First_Discriminant (Base_Type (Subtyp));
4758 -- Get the first component expression of the aggregate
4760 if Present (Expressions (Aggr)) then
4761 Disc_Exp := First (Expressions (Aggr));
4763 elsif Present (Component_Associations (Aggr)) then
4764 Assoc := First (Component_Associations (Aggr));
4766 if Present (Assoc) then
4767 Disc_Exp := Expression (Assoc);
4776 while Present (Discrim) and then Present (Disc_Exp) loop
4777 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4778 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4781 Next_Discriminant (Discrim);
4783 if Present (Discrim) then
4784 if Present (Assoc) then
4786 Disc_Exp := Expression (Assoc);
4788 elsif Present (Next (Disc_Exp)) then
4792 Assoc := First (Component_Associations (Aggr));
4794 if Present (Assoc) then
4795 Disc_Exp := Expression (Assoc);
4805 -- For a subtype mark or subtype indication, freeze the subtype
4808 Freeze_Expression (E);
4810 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4812 ("initialization required for access-to-constant allocator", N);
4815 -- A special accessibility check is needed for allocators that
4816 -- constrain access discriminants. The level of the type of the
4817 -- expression used to constrain an access discriminant cannot be
4818 -- deeper than the type of the allocator (in contrast to access
4819 -- parameters, where the level of the actual can be arbitrary).
4820 -- We can't use Valid_Conversion to perform this check because
4821 -- in general the type of the allocator is unrelated to the type
4822 -- of the access discriminant.
4824 if Nkind (Original_Node (E)) = N_Subtype_Indication
4825 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4826 or else Is_Local_Anonymous_Access (Typ))
4828 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4830 if Has_Discriminants (Subtyp) then
4831 Discrim := First_Discriminant (Base_Type (Subtyp));
4832 Constr := First (Constraints (Constraint (Original_Node (E))));
4833 while Present (Discrim) and then Present (Constr) loop
4834 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4835 if Nkind (Constr) = N_Discriminant_Association then
4836 Disc_Exp := Original_Node (Expression (Constr));
4838 Disc_Exp := Original_Node (Constr);
4841 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4844 Next_Discriminant (Discrim);
4851 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4852 -- check that the level of the type of the created object is not deeper
4853 -- than the level of the allocator's access type, since extensions can
4854 -- now occur at deeper levels than their ancestor types. This is a
4855 -- static accessibility level check; a run-time check is also needed in
4856 -- the case of an initialized allocator with a class-wide argument (see
4857 -- Expand_Allocator_Expression).
4859 if Ada_Version >= Ada_2005
4860 and then Is_Class_Wide_Type (Desig_T)
4863 Exp_Typ : Entity_Id;
4866 if Nkind (E) = N_Qualified_Expression then
4867 Exp_Typ := Etype (E);
4868 elsif Nkind (E) = N_Subtype_Indication then
4869 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4871 Exp_Typ := Entity (E);
4874 if Type_Access_Level (Exp_Typ) >
4875 Deepest_Type_Access_Level (Typ)
4877 if In_Instance_Body then
4878 Error_Msg_Warn := SPARK_Mode /= On;
4880 ("type in allocator has deeper level than "
4881 & "designated class-wide type<<", E);
4882 Error_Msg_N ("\Program_Error [<<", E);
4884 Make_Raise_Program_Error (Sloc (N),
4885 Reason => PE_Accessibility_Check_Failed));
4888 -- Do not apply Ada 2005 accessibility checks on a class-wide
4889 -- allocator if the type given in the allocator is a formal
4890 -- type. A run-time check will be performed in the instance.
4892 elsif not Is_Generic_Type (Exp_Typ) then
4893 Error_Msg_N ("type in allocator has deeper level than "
4894 & "designated class-wide type", E);
4900 -- Check for allocation from an empty storage pool
4902 if No_Pool_Assigned (Typ) then
4903 Error_Msg_N ("allocation from empty storage pool!", N);
4905 -- If the context is an unchecked conversion, as may happen within an
4906 -- inlined subprogram, the allocator is being resolved with its own
4907 -- anonymous type. In that case, if the target type has a specific
4908 -- storage pool, it must be inherited explicitly by the allocator type.
4910 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4911 and then No (Associated_Storage_Pool (Typ))
4913 Set_Associated_Storage_Pool
4914 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4917 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4918 Check_Restriction (No_Anonymous_Allocators, N);
4921 -- Check that an allocator with task parts isn't for a nested access
4922 -- type when restriction No_Task_Hierarchy applies.
4924 if not Is_Library_Level_Entity (Base_Type (Typ))
4925 and then Has_Task (Base_Type (Desig_T))
4927 Check_Restriction (No_Task_Hierarchy, N);
4930 -- An illegal allocator may be rewritten as a raise Program_Error
4933 if Nkind (N) = N_Allocator then
4935 -- An anonymous access discriminant is the definition of a
4938 if Ekind (Typ) = E_Anonymous_Access_Type
4939 and then Nkind (Associated_Node_For_Itype (Typ)) =
4940 N_Discriminant_Specification
4943 Discr : constant Entity_Id :=
4944 Defining_Identifier (Associated_Node_For_Itype (Typ));
4947 Check_Restriction (No_Coextensions, N);
4949 -- Ada 2012 AI05-0052: If the designated type of the allocator
4950 -- is limited, then the allocator shall not be used to define
4951 -- the value of an access discriminant unless the discriminated
4952 -- type is immutably limited.
4954 if Ada_Version >= Ada_2012
4955 and then Is_Limited_Type (Desig_T)
4956 and then not Is_Limited_View (Scope (Discr))
4959 ("only immutably limited types can have anonymous "
4960 & "access discriminants designating a limited type", N);
4964 -- Avoid marking an allocator as a dynamic coextension if it is
4965 -- within a static construct.
4967 if not Is_Static_Coextension (N) then
4968 Set_Is_Dynamic_Coextension (N);
4971 -- Cleanup for potential static coextensions
4974 Set_Is_Dynamic_Coextension (N, False);
4975 Set_Is_Static_Coextension (N, False);
4979 -- Report a simple error: if the designated object is a local task,
4980 -- its body has not been seen yet, and its activation will fail an
4981 -- elaboration check.
4983 if Is_Task_Type (Desig_T)
4984 and then Scope (Base_Type (Desig_T)) = Current_Scope
4985 and then Is_Compilation_Unit (Current_Scope)
4986 and then Ekind (Current_Scope) = E_Package
4987 and then not In_Package_Body (Current_Scope)
4989 Error_Msg_Warn := SPARK_Mode /= On;
4990 Error_Msg_N ("cannot activate task before body seen<<", N);
4991 Error_Msg_N ("\Program_Error [<<", N);
4994 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
4995 -- type with a task component on a subpool. This action must raise
4996 -- Program_Error at runtime.
4998 if Ada_Version >= Ada_2012
4999 and then Nkind (N) = N_Allocator
5000 and then Present (Subpool_Handle_Name (N))
5001 and then Has_Task (Desig_T)
5003 Error_Msg_Warn := SPARK_Mode /= On;
5004 Error_Msg_N ("cannot allocate task on subpool<<", N);
5005 Error_Msg_N ("\Program_Error [<<", N);
5008 Make_Raise_Program_Error (Sloc (N),
5009 Reason => PE_Explicit_Raise));
5012 end Resolve_Allocator;
5014 ---------------------------
5015 -- Resolve_Arithmetic_Op --
5016 ---------------------------
5018 -- Used for resolving all arithmetic operators except exponentiation
5020 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5021 L : constant Node_Id := Left_Opnd (N);
5022 R : constant Node_Id := Right_Opnd (N);
5023 TL : constant Entity_Id := Base_Type (Etype (L));
5024 TR : constant Entity_Id := Base_Type (Etype (R));
5028 B_Typ : constant Entity_Id := Base_Type (Typ);
5029 -- We do the resolution using the base type, because intermediate values
5030 -- in expressions always are of the base type, not a subtype of it.
5032 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5033 -- Returns True if N is in a context that expects "any real type"
5035 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5036 -- Return True iff given type is Integer or universal real/integer
5038 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5039 -- Choose type of integer literal in fixed-point operation to conform
5040 -- to available fixed-point type. T is the type of the other operand,
5041 -- which is needed to determine the expected type of N.
5043 procedure Set_Operand_Type (N : Node_Id);
5044 -- Set operand type to T if universal
5046 -------------------------------
5047 -- Expected_Type_Is_Any_Real --
5048 -------------------------------
5050 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5052 -- N is the expression after "delta" in a fixed_point_definition;
5055 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5056 N_Decimal_Fixed_Point_Definition,
5058 -- N is one of the bounds in a real_range_specification;
5061 N_Real_Range_Specification,
5063 -- N is the expression of a delta_constraint;
5066 N_Delta_Constraint);
5067 end Expected_Type_Is_Any_Real;
5069 -----------------------------
5070 -- Is_Integer_Or_Universal --
5071 -----------------------------
5073 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5075 Index : Interp_Index;
5079 if not Is_Overloaded (N) then
5081 return Base_Type (T) = Base_Type (Standard_Integer)
5082 or else T = Universal_Integer
5083 or else T = Universal_Real;
5085 Get_First_Interp (N, Index, It);
5086 while Present (It.Typ) loop
5087 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5088 or else It.Typ = Universal_Integer
5089 or else It.Typ = Universal_Real
5094 Get_Next_Interp (Index, It);
5099 end Is_Integer_Or_Universal;
5101 ----------------------------
5102 -- Set_Mixed_Mode_Operand --
5103 ----------------------------
5105 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5106 Index : Interp_Index;
5110 if Universal_Interpretation (N) = Universal_Integer then
5112 -- A universal integer literal is resolved as standard integer
5113 -- except in the case of a fixed-point result, where we leave it
5114 -- as universal (to be handled by Exp_Fixd later on)
5116 if Is_Fixed_Point_Type (T) then
5117 Resolve (N, Universal_Integer);
5119 Resolve (N, Standard_Integer);
5122 elsif Universal_Interpretation (N) = Universal_Real
5123 and then (T = Base_Type (Standard_Integer)
5124 or else T = Universal_Integer
5125 or else T = Universal_Real)
5127 -- A universal real can appear in a fixed-type context. We resolve
5128 -- the literal with that context, even though this might raise an
5129 -- exception prematurely (the other operand may be zero).
5133 elsif Etype (N) = Base_Type (Standard_Integer)
5134 and then T = Universal_Real
5135 and then Is_Overloaded (N)
5137 -- Integer arg in mixed-mode operation. Resolve with universal
5138 -- type, in case preference rule must be applied.
5140 Resolve (N, Universal_Integer);
5143 and then B_Typ /= Universal_Fixed
5145 -- Not a mixed-mode operation, resolve with context
5149 elsif Etype (N) = Any_Fixed then
5151 -- N may itself be a mixed-mode operation, so use context type
5155 elsif Is_Fixed_Point_Type (T)
5156 and then B_Typ = Universal_Fixed
5157 and then Is_Overloaded (N)
5159 -- Must be (fixed * fixed) operation, operand must have one
5160 -- compatible interpretation.
5162 Resolve (N, Any_Fixed);
5164 elsif Is_Fixed_Point_Type (B_Typ)
5165 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5166 and then Is_Overloaded (N)
5168 -- C * F(X) in a fixed context, where C is a real literal or a
5169 -- fixed-point expression. F must have either a fixed type
5170 -- interpretation or an integer interpretation, but not both.
5172 Get_First_Interp (N, Index, It);
5173 while Present (It.Typ) loop
5174 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5175 if Analyzed (N) then
5176 Error_Msg_N ("ambiguous operand in fixed operation", N);
5178 Resolve (N, Standard_Integer);
5181 elsif Is_Fixed_Point_Type (It.Typ) then
5182 if Analyzed (N) then
5183 Error_Msg_N ("ambiguous operand in fixed operation", N);
5185 Resolve (N, It.Typ);
5189 Get_Next_Interp (Index, It);
5192 -- Reanalyze the literal with the fixed type of the context. If
5193 -- context is Universal_Fixed, we are within a conversion, leave
5194 -- the literal as a universal real because there is no usable
5195 -- fixed type, and the target of the conversion plays no role in
5209 if B_Typ = Universal_Fixed
5210 and then Nkind (Op2) = N_Real_Literal
5212 T2 := Universal_Real;
5217 Set_Analyzed (Op2, False);
5224 end Set_Mixed_Mode_Operand;
5226 ----------------------
5227 -- Set_Operand_Type --
5228 ----------------------
5230 procedure Set_Operand_Type (N : Node_Id) is
5232 if Etype (N) = Universal_Integer
5233 or else Etype (N) = Universal_Real
5237 end Set_Operand_Type;
5239 -- Start of processing for Resolve_Arithmetic_Op
5242 if Comes_From_Source (N)
5243 and then Ekind (Entity (N)) = E_Function
5244 and then Is_Imported (Entity (N))
5245 and then Is_Intrinsic_Subprogram (Entity (N))
5247 Resolve_Intrinsic_Operator (N, Typ);
5250 -- Special-case for mixed-mode universal expressions or fixed point type
5251 -- operation: each argument is resolved separately. The same treatment
5252 -- is required if one of the operands of a fixed point operation is
5253 -- universal real, since in this case we don't do a conversion to a
5254 -- specific fixed-point type (instead the expander handles the case).
5256 -- Set the type of the node to its universal interpretation because
5257 -- legality checks on an exponentiation operand need the context.
5259 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5260 and then Present (Universal_Interpretation (L))
5261 and then Present (Universal_Interpretation (R))
5263 Set_Etype (N, B_Typ);
5264 Resolve (L, Universal_Interpretation (L));
5265 Resolve (R, Universal_Interpretation (R));
5267 elsif (B_Typ = Universal_Real
5268 or else Etype (N) = Universal_Fixed
5269 or else (Etype (N) = Any_Fixed
5270 and then Is_Fixed_Point_Type (B_Typ))
5271 or else (Is_Fixed_Point_Type (B_Typ)
5272 and then (Is_Integer_Or_Universal (L)
5274 Is_Integer_Or_Universal (R))))
5275 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5277 if TL = Universal_Integer or else TR = Universal_Integer then
5278 Check_For_Visible_Operator (N, B_Typ);
5281 -- If context is a fixed type and one operand is integer, the other
5282 -- is resolved with the type of the context.
5284 if Is_Fixed_Point_Type (B_Typ)
5285 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5286 or else TL = Universal_Integer)
5291 elsif Is_Fixed_Point_Type (B_Typ)
5292 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5293 or else TR = Universal_Integer)
5299 Set_Mixed_Mode_Operand (L, TR);
5300 Set_Mixed_Mode_Operand (R, TL);
5303 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5304 -- multiplying operators from being used when the expected type is
5305 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5306 -- some cases where the expected type is actually Any_Real;
5307 -- Expected_Type_Is_Any_Real takes care of that case.
5309 if Etype (N) = Universal_Fixed
5310 or else Etype (N) = Any_Fixed
5312 if B_Typ = Universal_Fixed
5313 and then not Expected_Type_Is_Any_Real (N)
5314 and then not Nkind_In (Parent (N), N_Type_Conversion,
5315 N_Unchecked_Type_Conversion)
5317 Error_Msg_N ("type cannot be determined from context!", N);
5318 Error_Msg_N ("\explicit conversion to result type required", N);
5320 Set_Etype (L, Any_Type);
5321 Set_Etype (R, Any_Type);
5324 if Ada_Version = Ada_83
5325 and then Etype (N) = Universal_Fixed
5327 Nkind_In (Parent (N), N_Type_Conversion,
5328 N_Unchecked_Type_Conversion)
5331 ("(Ada 83) fixed-point operation needs explicit "
5335 -- The expected type is "any real type" in contexts like
5337 -- type T is delta <universal_fixed-expression> ...
5339 -- in which case we need to set the type to Universal_Real
5340 -- so that static expression evaluation will work properly.
5342 if Expected_Type_Is_Any_Real (N) then
5343 Set_Etype (N, Universal_Real);
5345 Set_Etype (N, B_Typ);
5349 elsif Is_Fixed_Point_Type (B_Typ)
5350 and then (Is_Integer_Or_Universal (L)
5351 or else Nkind (L) = N_Real_Literal
5352 or else Nkind (R) = N_Real_Literal
5353 or else Is_Integer_Or_Universal (R))
5355 Set_Etype (N, B_Typ);
5357 elsif Etype (N) = Any_Fixed then
5359 -- If no previous errors, this is only possible if one operand is
5360 -- overloaded and the context is universal. Resolve as such.
5362 Set_Etype (N, B_Typ);
5366 if (TL = Universal_Integer or else TL = Universal_Real)
5368 (TR = Universal_Integer or else TR = Universal_Real)
5370 Check_For_Visible_Operator (N, B_Typ);
5373 -- If the context is Universal_Fixed and the operands are also
5374 -- universal fixed, this is an error, unless there is only one
5375 -- applicable fixed_point type (usually Duration).
5377 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5378 T := Unique_Fixed_Point_Type (N);
5380 if T = Any_Type then
5393 -- If one of the arguments was resolved to a non-universal type.
5394 -- label the result of the operation itself with the same type.
5395 -- Do the same for the universal argument, if any.
5397 T := Intersect_Types (L, R);
5398 Set_Etype (N, Base_Type (T));
5399 Set_Operand_Type (L);
5400 Set_Operand_Type (R);
5403 Generate_Operator_Reference (N, Typ);
5404 Analyze_Dimension (N);
5405 Eval_Arithmetic_Op (N);
5407 -- In SPARK, a multiplication or division with operands of fixed point
5408 -- types must be qualified or explicitly converted to identify the
5411 if (Is_Fixed_Point_Type (Etype (L))
5412 or else Is_Fixed_Point_Type (Etype (R)))
5413 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5415 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5417 Check_SPARK_05_Restriction
5418 ("operation should be qualified or explicitly converted", N);
5421 -- Set overflow and division checking bit
5423 if Nkind (N) in N_Op then
5424 if not Overflow_Checks_Suppressed (Etype (N)) then
5425 Enable_Overflow_Check (N);
5428 -- Give warning if explicit division by zero
5430 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5431 and then not Division_Checks_Suppressed (Etype (N))
5433 Rop := Right_Opnd (N);
5435 if Compile_Time_Known_Value (Rop)
5436 and then ((Is_Integer_Type (Etype (Rop))
5437 and then Expr_Value (Rop) = Uint_0)
5439 (Is_Real_Type (Etype (Rop))
5440 and then Expr_Value_R (Rop) = Ureal_0))
5442 -- Specialize the warning message according to the operation.
5443 -- The following warnings are for the case
5448 -- For division, we have two cases, for float division
5449 -- of an unconstrained float type, on a machine where
5450 -- Machine_Overflows is false, we don't get an exception
5451 -- at run-time, but rather an infinity or Nan. The Nan
5452 -- case is pretty obscure, so just warn about infinities.
5454 if Is_Floating_Point_Type (Typ)
5455 and then not Is_Constrained (Typ)
5456 and then not Machine_Overflows_On_Target
5459 ("float division by zero, may generate "
5460 & "'+'/'- infinity??", Right_Opnd (N));
5462 -- For all other cases, we get a Constraint_Error
5465 Apply_Compile_Time_Constraint_Error
5466 (N, "division by zero??", CE_Divide_By_Zero,
5467 Loc => Sloc (Right_Opnd (N)));
5471 Apply_Compile_Time_Constraint_Error
5472 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5473 Loc => Sloc (Right_Opnd (N)));
5476 Apply_Compile_Time_Constraint_Error
5477 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5478 Loc => Sloc (Right_Opnd (N)));
5480 -- Division by zero can only happen with division, rem,
5481 -- and mod operations.
5484 raise Program_Error;
5487 -- Otherwise just set the flag to check at run time
5490 Activate_Division_Check (N);
5494 -- If Restriction No_Implicit_Conditionals is active, then it is
5495 -- violated if either operand can be negative for mod, or for rem
5496 -- if both operands can be negative.
5498 if Restriction_Check_Required (No_Implicit_Conditionals)
5499 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5508 -- Set if corresponding operand might be negative
5512 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5513 LNeg := (not OK) or else Lo < 0;
5516 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5517 RNeg := (not OK) or else Lo < 0;
5519 -- Check if we will be generating conditionals. There are two
5520 -- cases where that can happen, first for REM, the only case
5521 -- is largest negative integer mod -1, where the division can
5522 -- overflow, but we still have to give the right result. The
5523 -- front end generates a test for this annoying case. Here we
5524 -- just test if both operands can be negative (that's what the
5525 -- expander does, so we match its logic here).
5527 -- The second case is mod where either operand can be negative.
5528 -- In this case, the back end has to generate additional tests.
5530 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5532 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5534 Check_Restriction (No_Implicit_Conditionals, N);
5540 Check_Unset_Reference (L);
5541 Check_Unset_Reference (R);
5542 end Resolve_Arithmetic_Op;
5548 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5549 function Same_Or_Aliased_Subprograms
5551 E : Entity_Id) return Boolean;
5552 -- Returns True if the subprogram entity S is the same as E or else
5553 -- S is an alias of E.
5555 ---------------------------------
5556 -- Same_Or_Aliased_Subprograms --
5557 ---------------------------------
5559 function Same_Or_Aliased_Subprograms
5561 E : Entity_Id) return Boolean
5563 Subp_Alias : constant Entity_Id := Alias (S);
5565 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5566 end Same_Or_Aliased_Subprograms;
5570 Loc : constant Source_Ptr := Sloc (N);
5571 Subp : constant Node_Id := Name (N);
5572 Body_Id : Entity_Id;
5582 -- Start of processing for Resolve_Call
5585 -- The context imposes a unique interpretation with type Typ on a
5586 -- procedure or function call. Find the entity of the subprogram that
5587 -- yields the expected type, and propagate the corresponding formal
5588 -- constraints on the actuals. The caller has established that an
5589 -- interpretation exists, and emitted an error if not unique.
5591 -- First deal with the case of a call to an access-to-subprogram,
5592 -- dereference made explicit in Analyze_Call.
5594 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5595 if not Is_Overloaded (Subp) then
5596 Nam := Etype (Subp);
5599 -- Find the interpretation whose type (a subprogram type) has a
5600 -- return type that is compatible with the context. Analysis of
5601 -- the node has established that one exists.
5605 Get_First_Interp (Subp, I, It);
5606 while Present (It.Typ) loop
5607 if Covers (Typ, Etype (It.Typ)) then
5612 Get_Next_Interp (I, It);
5616 raise Program_Error;
5620 -- If the prefix is not an entity, then resolve it
5622 if not Is_Entity_Name (Subp) then
5623 Resolve (Subp, Nam);
5626 -- For an indirect call, we always invalidate checks, since we do not
5627 -- know whether the subprogram is local or global. Yes we could do
5628 -- better here, e.g. by knowing that there are no local subprograms,
5629 -- but it does not seem worth the effort. Similarly, we kill all
5630 -- knowledge of current constant values.
5632 Kill_Current_Values;
5634 -- If this is a procedure call which is really an entry call, do
5635 -- the conversion of the procedure call to an entry call. Protected
5636 -- operations use the same circuitry because the name in the call
5637 -- can be an arbitrary expression with special resolution rules.
5639 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5640 or else (Is_Entity_Name (Subp)
5641 and then Ekind (Entity (Subp)) = E_Entry)
5643 Resolve_Entry_Call (N, Typ);
5644 Check_Elab_Call (N);
5646 -- Kill checks and constant values, as above for indirect case
5647 -- Who knows what happens when another task is activated?
5649 Kill_Current_Values;
5652 -- Normal subprogram call with name established in Resolve
5654 elsif not (Is_Type (Entity (Subp))) then
5655 Nam := Entity (Subp);
5656 Set_Entity_With_Checks (Subp, Nam);
5658 -- Otherwise we must have the case of an overloaded call
5661 pragma Assert (Is_Overloaded (Subp));
5663 -- Initialize Nam to prevent warning (we know it will be assigned
5664 -- in the loop below, but the compiler does not know that).
5668 Get_First_Interp (Subp, I, It);
5669 while Present (It.Typ) loop
5670 if Covers (Typ, It.Typ) then
5672 Set_Entity_With_Checks (Subp, Nam);
5676 Get_Next_Interp (I, It);
5680 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5681 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5682 and then Nkind (Subp) /= N_Explicit_Dereference
5683 and then Present (Parameter_Associations (N))
5685 -- The prefix is a parameterless function call that returns an access
5686 -- to subprogram. If parameters are present in the current call, add
5687 -- add an explicit dereference. We use the base type here because
5688 -- within an instance these may be subtypes.
5690 -- The dereference is added either in Analyze_Call or here. Should
5691 -- be consolidated ???
5693 Set_Is_Overloaded (Subp, False);
5694 Set_Etype (Subp, Etype (Nam));
5695 Insert_Explicit_Dereference (Subp);
5696 Nam := Designated_Type (Etype (Nam));
5697 Resolve (Subp, Nam);
5700 -- Check that a call to Current_Task does not occur in an entry body
5702 if Is_RTE (Nam, RE_Current_Task) then
5711 -- Exclude calls that occur within the default of a formal
5712 -- parameter of the entry, since those are evaluated outside
5715 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5717 if Nkind (P) = N_Entry_Body
5718 or else (Nkind (P) = N_Subprogram_Body
5719 and then Is_Entry_Barrier_Function (P))
5722 Error_Msg_Warn := SPARK_Mode /= On;
5724 ("& should not be used in entry body (RM C.7(17))<<",
5726 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5728 Make_Raise_Program_Error (Loc,
5729 Reason => PE_Current_Task_In_Entry_Body));
5730 Set_Etype (N, Rtype);
5737 -- Check that a procedure call does not occur in the context of the
5738 -- entry call statement of a conditional or timed entry call. Note that
5739 -- the case of a call to a subprogram renaming of an entry will also be
5740 -- rejected. The test for N not being an N_Entry_Call_Statement is
5741 -- defensive, covering the possibility that the processing of entry
5742 -- calls might reach this point due to later modifications of the code
5745 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5746 and then Nkind (N) /= N_Entry_Call_Statement
5747 and then Entry_Call_Statement (Parent (N)) = N
5749 if Ada_Version < Ada_2005 then
5750 Error_Msg_N ("entry call required in select statement", N);
5752 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5753 -- for a procedure_or_entry_call, the procedure_name or
5754 -- procedure_prefix of the procedure_call_statement shall denote
5755 -- an entry renamed by a procedure, or (a view of) a primitive
5756 -- subprogram of a limited interface whose first parameter is
5757 -- a controlling parameter.
5759 elsif Nkind (N) = N_Procedure_Call_Statement
5760 and then not Is_Renamed_Entry (Nam)
5761 and then not Is_Controlling_Limited_Procedure (Nam)
5764 ("entry call or dispatching primitive of interface required", N);
5768 -- If the SPARK_05 restriction is active, we are not allowed
5769 -- to have a call to a subprogram before we see its completion.
5771 if not Has_Completion (Nam)
5772 and then Restriction_Check_Required (SPARK_05)
5774 -- Don't flag strange internal calls
5776 and then Comes_From_Source (N)
5777 and then Comes_From_Source (Nam)
5779 -- Only flag calls in extended main source
5781 and then In_Extended_Main_Source_Unit (Nam)
5782 and then In_Extended_Main_Source_Unit (N)
5784 -- Exclude enumeration literals from this processing
5786 and then Ekind (Nam) /= E_Enumeration_Literal
5788 Check_SPARK_05_Restriction
5789 ("call to subprogram cannot appear before its body", N);
5792 -- Check that this is not a call to a protected procedure or entry from
5793 -- within a protected function.
5795 Check_Internal_Protected_Use (N, Nam);
5797 -- Freeze the subprogram name if not in a spec-expression. Note that
5798 -- we freeze procedure calls as well as function calls. Procedure calls
5799 -- are not frozen according to the rules (RM 13.14(14)) because it is
5800 -- impossible to have a procedure call to a non-frozen procedure in
5801 -- pure Ada, but in the code that we generate in the expander, this
5802 -- rule needs extending because we can generate procedure calls that
5805 -- In Ada 2012, expression functions may be called within pre/post
5806 -- conditions of subsequent functions or expression functions. Such
5807 -- calls do not freeze when they appear within generated bodies,
5808 -- (including the body of another expression function) which would
5809 -- place the freeze node in the wrong scope. An expression function
5810 -- is frozen in the usual fashion, by the appearance of a real body,
5811 -- or at the end of a declarative part.
5813 if Is_Entity_Name (Subp)
5814 and then not In_Spec_Expression
5815 and then not Is_Expression_Function_Or_Completion (Current_Scope)
5817 (not Is_Expression_Function_Or_Completion (Entity (Subp))
5818 or else Scope (Entity (Subp)) = Current_Scope)
5820 Freeze_Expression (Subp);
5823 -- For a predefined operator, the type of the result is the type imposed
5824 -- by context, except for a predefined operation on universal fixed.
5825 -- Otherwise The type of the call is the type returned by the subprogram
5828 if Is_Predefined_Op (Nam) then
5829 if Etype (N) /= Universal_Fixed then
5833 -- If the subprogram returns an array type, and the context requires the
5834 -- component type of that array type, the node is really an indexing of
5835 -- the parameterless call. Resolve as such. A pathological case occurs
5836 -- when the type of the component is an access to the array type. In
5837 -- this case the call is truly ambiguous.
5839 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5841 ((Is_Array_Type (Etype (Nam))
5842 and then Covers (Typ, Component_Type (Etype (Nam))))
5844 (Is_Access_Type (Etype (Nam))
5845 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5847 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5850 Index_Node : Node_Id;
5852 Ret_Type : constant Entity_Id := Etype (Nam);
5855 if Is_Access_Type (Ret_Type)
5856 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5859 ("cannot disambiguate function call and indexing", N);
5861 New_Subp := Relocate_Node (Subp);
5863 -- The called entity may be an explicit dereference, in which
5864 -- case there is no entity to set.
5866 if Nkind (New_Subp) /= N_Explicit_Dereference then
5867 Set_Entity (Subp, Nam);
5870 if (Is_Array_Type (Ret_Type)
5871 and then Component_Type (Ret_Type) /= Any_Type)
5873 (Is_Access_Type (Ret_Type)
5875 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5877 if Needs_No_Actuals (Nam) then
5879 -- Indexed call to a parameterless function
5882 Make_Indexed_Component (Loc,
5884 Make_Function_Call (Loc, Name => New_Subp),
5885 Expressions => Parameter_Associations (N));
5887 -- An Ada 2005 prefixed call to a primitive operation
5888 -- whose first parameter is the prefix. This prefix was
5889 -- prepended to the parameter list, which is actually a
5890 -- list of indexes. Remove the prefix in order to build
5891 -- the proper indexed component.
5894 Make_Indexed_Component (Loc,
5896 Make_Function_Call (Loc,
5898 Parameter_Associations =>
5900 (Remove_Head (Parameter_Associations (N)))),
5901 Expressions => Parameter_Associations (N));
5904 -- Preserve the parenthesis count of the node
5906 Set_Paren_Count (Index_Node, Paren_Count (N));
5908 -- Since we are correcting a node classification error made
5909 -- by the parser, we call Replace rather than Rewrite.
5911 Replace (N, Index_Node);
5913 Set_Etype (Prefix (N), Ret_Type);
5915 Resolve_Indexed_Component (N, Typ);
5916 Check_Elab_Call (Prefix (N));
5924 Set_Etype (N, Etype (Nam));
5927 -- In the case where the call is to an overloaded subprogram, Analyze
5928 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5929 -- such a case Normalize_Actuals needs to be called once more to order
5930 -- the actuals correctly. Otherwise the call will have the ordering
5931 -- given by the last overloaded subprogram whether this is the correct
5932 -- one being called or not.
5934 if Is_Overloaded (Subp) then
5935 Normalize_Actuals (N, Nam, False, Norm_OK);
5936 pragma Assert (Norm_OK);
5939 -- In any case, call is fully resolved now. Reset Overload flag, to
5940 -- prevent subsequent overload resolution if node is analyzed again
5942 Set_Is_Overloaded (Subp, False);
5943 Set_Is_Overloaded (N, False);
5945 -- A Ghost entity must appear in a specific context
5947 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
5948 Check_Ghost_Context (Nam, N);
5951 -- If we are calling the current subprogram from immediately within its
5952 -- body, then that is the case where we can sometimes detect cases of
5953 -- infinite recursion statically. Do not try this in case restriction
5954 -- No_Recursion is in effect anyway, and do it only for source calls.
5956 if Comes_From_Source (N) then
5957 Scop := Current_Scope;
5959 -- Check violation of SPARK_05 restriction which does not permit
5960 -- a subprogram body to contain a call to the subprogram directly.
5962 if Restriction_Check_Required (SPARK_05)
5963 and then Same_Or_Aliased_Subprograms (Nam, Scop)
5965 Check_SPARK_05_Restriction
5966 ("subprogram may not contain direct call to itself", N);
5969 -- Issue warning for possible infinite recursion in the absence
5970 -- of the No_Recursion restriction.
5972 if Same_Or_Aliased_Subprograms (Nam, Scop)
5973 and then not Restriction_Active (No_Recursion)
5974 and then Check_Infinite_Recursion (N)
5976 -- Here we detected and flagged an infinite recursion, so we do
5977 -- not need to test the case below for further warnings. Also we
5978 -- are all done if we now have a raise SE node.
5980 if Nkind (N) = N_Raise_Storage_Error then
5984 -- If call is to immediately containing subprogram, then check for
5985 -- the case of a possible run-time detectable infinite recursion.
5988 Scope_Loop : while Scop /= Standard_Standard loop
5989 if Same_Or_Aliased_Subprograms (Nam, Scop) then
5991 -- Although in general case, recursion is not statically
5992 -- checkable, the case of calling an immediately containing
5993 -- subprogram is easy to catch.
5995 Check_Restriction (No_Recursion, N);
5997 -- If the recursive call is to a parameterless subprogram,
5998 -- then even if we can't statically detect infinite
5999 -- recursion, this is pretty suspicious, and we output a
6000 -- warning. Furthermore, we will try later to detect some
6001 -- cases here at run time by expanding checking code (see
6002 -- Detect_Infinite_Recursion in package Exp_Ch6).
6004 -- If the recursive call is within a handler, do not emit a
6005 -- warning, because this is a common idiom: loop until input
6006 -- is correct, catch illegal input in handler and restart.
6008 if No (First_Formal (Nam))
6009 and then Etype (Nam) = Standard_Void_Type
6010 and then not Error_Posted (N)
6011 and then Nkind (Parent (N)) /= N_Exception_Handler
6013 -- For the case of a procedure call. We give the message
6014 -- only if the call is the first statement in a sequence
6015 -- of statements, or if all previous statements are
6016 -- simple assignments. This is simply a heuristic to
6017 -- decrease false positives, without losing too many good
6018 -- warnings. The idea is that these previous statements
6019 -- may affect global variables the procedure depends on.
6020 -- We also exclude raise statements, that may arise from
6021 -- constraint checks and are probably unrelated to the
6022 -- intended control flow.
6024 if Nkind (N) = N_Procedure_Call_Statement
6025 and then Is_List_Member (N)
6031 while Present (P) loop
6032 if not Nkind_In (P, N_Assignment_Statement,
6033 N_Raise_Constraint_Error)
6043 -- Do not give warning if we are in a conditional context
6046 K : constant Node_Kind := Nkind (Parent (N));
6048 if (K = N_Loop_Statement
6049 and then Present (Iteration_Scheme (Parent (N))))
6050 or else K = N_If_Statement
6051 or else K = N_Elsif_Part
6052 or else K = N_Case_Statement_Alternative
6058 -- Here warning is to be issued
6060 Set_Has_Recursive_Call (Nam);
6061 Error_Msg_Warn := SPARK_Mode /= On;
6062 Error_Msg_N ("possible infinite recursion<<!", N);
6063 Error_Msg_N ("\Storage_Error ]<<!", N);
6069 Scop := Scope (Scop);
6070 end loop Scope_Loop;
6074 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6076 Check_Obsolescent_2005_Entity (Nam, Subp);
6078 -- If subprogram name is a predefined operator, it was given in
6079 -- functional notation. Replace call node with operator node, so
6080 -- that actuals can be resolved appropriately.
6082 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6083 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6086 elsif Present (Alias (Nam))
6087 and then Is_Predefined_Op (Alias (Nam))
6089 Resolve_Actuals (N, Nam);
6090 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6094 -- Create a transient scope if the resulting type requires it
6096 -- There are several notable exceptions:
6098 -- a) In init procs, the transient scope overhead is not needed, and is
6099 -- even incorrect when the call is a nested initialization call for a
6100 -- component whose expansion may generate adjust calls. However, if the
6101 -- call is some other procedure call within an initialization procedure
6102 -- (for example a call to Create_Task in the init_proc of the task
6103 -- run-time record) a transient scope must be created around this call.
6105 -- b) Enumeration literal pseudo-calls need no transient scope
6107 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6108 -- functions) do not use the secondary stack even though the return
6109 -- type may be unconstrained.
6111 -- d) Calls to a build-in-place function, since such functions may
6112 -- allocate their result directly in a target object, and cases where
6113 -- the result does get allocated in the secondary stack are checked for
6114 -- within the specialized Exp_Ch6 procedures for expanding those
6115 -- build-in-place calls.
6117 -- e) If the subprogram is marked Inline_Always, then even if it returns
6118 -- an unconstrained type the call does not require use of the secondary
6119 -- stack. However, inlining will only take place if the body to inline
6120 -- is already present. It may not be available if e.g. the subprogram is
6121 -- declared in a child instance.
6123 -- If this is an initialization call for a type whose construction
6124 -- uses the secondary stack, and it is not a nested call to initialize
6125 -- a component, we do need to create a transient scope for it. We
6126 -- check for this by traversing the type in Check_Initialization_Call.
6129 and then Has_Pragma_Inline (Nam)
6130 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6131 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6135 elsif Ekind (Nam) = E_Enumeration_Literal
6136 or else Is_Build_In_Place_Function (Nam)
6137 or else Is_Intrinsic_Subprogram (Nam)
6141 elsif Expander_Active
6142 and then Is_Type (Etype (Nam))
6143 and then Requires_Transient_Scope (Etype (Nam))
6145 (not Within_Init_Proc
6147 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6149 Establish_Transient_Scope (N, Sec_Stack => True);
6151 -- If the call appears within the bounds of a loop, it will
6152 -- be rewritten and reanalyzed, nothing left to do here.
6154 if Nkind (N) /= N_Function_Call then
6158 elsif Is_Init_Proc (Nam)
6159 and then not Within_Init_Proc
6161 Check_Initialization_Call (N, Nam);
6164 -- A protected function cannot be called within the definition of the
6165 -- enclosing protected type, unless it is part of a pre/postcondition
6166 -- on another protected operation.
6168 if Is_Protected_Type (Scope (Nam))
6169 and then In_Open_Scopes (Scope (Nam))
6170 and then not Has_Completion (Scope (Nam))
6171 and then not In_Spec_Expression
6174 ("& cannot be called before end of protected definition", N, Nam);
6177 -- Propagate interpretation to actuals, and add default expressions
6180 if Present (First_Formal (Nam)) then
6181 Resolve_Actuals (N, Nam);
6183 -- Overloaded literals are rewritten as function calls, for purpose of
6184 -- resolution. After resolution, we can replace the call with the
6187 elsif Ekind (Nam) = E_Enumeration_Literal then
6188 Copy_Node (Subp, N);
6189 Resolve_Entity_Name (N, Typ);
6191 -- Avoid validation, since it is a static function call
6193 Generate_Reference (Nam, Subp);
6197 -- If the subprogram is not global, then kill all saved values and
6198 -- checks. This is a bit conservative, since in many cases we could do
6199 -- better, but it is not worth the effort. Similarly, we kill constant
6200 -- values. However we do not need to do this for internal entities
6201 -- (unless they are inherited user-defined subprograms), since they
6202 -- are not in the business of molesting local values.
6204 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6205 -- kill all checks and values for calls to global subprograms. This
6206 -- takes care of the case where an access to a local subprogram is
6207 -- taken, and could be passed directly or indirectly and then called
6208 -- from almost any context.
6210 -- Note: we do not do this step till after resolving the actuals. That
6211 -- way we still take advantage of the current value information while
6212 -- scanning the actuals.
6214 -- We suppress killing values if we are processing the nodes associated
6215 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6216 -- type kills all the values as part of analyzing the code that
6217 -- initializes the dispatch tables.
6219 if Inside_Freezing_Actions = 0
6220 and then (not Is_Library_Level_Entity (Nam)
6221 or else Suppress_Value_Tracking_On_Call
6222 (Nearest_Dynamic_Scope (Current_Scope)))
6223 and then (Comes_From_Source (Nam)
6224 or else (Present (Alias (Nam))
6225 and then Comes_From_Source (Alias (Nam))))
6227 Kill_Current_Values;
6230 -- If we are warning about unread OUT parameters, this is the place to
6231 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6232 -- after the above call to Kill_Current_Values (since that call clears
6233 -- the Last_Assignment field of all local variables).
6235 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6236 and then Comes_From_Source (N)
6237 and then In_Extended_Main_Source_Unit (N)
6244 F := First_Formal (Nam);
6245 A := First_Actual (N);
6246 while Present (F) and then Present (A) loop
6247 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6248 and then Warn_On_Modified_As_Out_Parameter (F)
6249 and then Is_Entity_Name (A)
6250 and then Present (Entity (A))
6251 and then Comes_From_Source (N)
6252 and then Safe_To_Capture_Value (N, Entity (A))
6254 Set_Last_Assignment (Entity (A), A);
6263 -- If the subprogram is a primitive operation, check whether or not
6264 -- it is a correct dispatching call.
6266 if Is_Overloadable (Nam)
6267 and then Is_Dispatching_Operation (Nam)
6269 Check_Dispatching_Call (N);
6271 elsif Ekind (Nam) /= E_Subprogram_Type
6272 and then Is_Abstract_Subprogram (Nam)
6273 and then not In_Instance
6275 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6278 -- If this is a dispatching call, generate the appropriate reference,
6279 -- for better source navigation in GPS.
6281 if Is_Overloadable (Nam)
6282 and then Present (Controlling_Argument (N))
6284 Generate_Reference (Nam, Subp, 'R');
6286 -- Normal case, not a dispatching call: generate a call reference
6289 Generate_Reference (Nam, Subp, 's');
6292 if Is_Intrinsic_Subprogram (Nam) then
6293 Check_Intrinsic_Call (N);
6296 -- Check for violation of restriction No_Specific_Termination_Handlers
6297 -- and warn on a potentially blocking call to Abort_Task.
6299 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6300 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6302 Is_RTE (Nam, RE_Specific_Handler))
6304 Check_Restriction (No_Specific_Termination_Handlers, N);
6306 elsif Is_RTE (Nam, RE_Abort_Task) then
6307 Check_Potentially_Blocking_Operation (N);
6310 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6311 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6312 -- need to check the second argument to determine whether it is an
6313 -- absolute or relative timing event.
6315 if Restriction_Check_Required (No_Relative_Delay)
6316 and then Is_RTE (Nam, RE_Set_Handler)
6317 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6319 Check_Restriction (No_Relative_Delay, N);
6322 -- Issue an error for a call to an eliminated subprogram. This routine
6323 -- will not perform the check if the call appears within a default
6326 Check_For_Eliminated_Subprogram (Subp, Nam);
6328 -- In formal mode, the primitive operations of a tagged type or type
6329 -- extension do not include functions that return the tagged type.
6331 if Nkind (N) = N_Function_Call
6332 and then Is_Tagged_Type (Etype (N))
6333 and then Is_Entity_Name (Name (N))
6334 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6336 Check_SPARK_05_Restriction ("function not inherited", N);
6339 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6340 -- class-wide and the call dispatches on result in a context that does
6341 -- not provide a tag, the call raises Program_Error.
6343 if Nkind (N) = N_Function_Call
6344 and then In_Instance
6345 and then Is_Generic_Actual_Type (Typ)
6346 and then Is_Class_Wide_Type (Typ)
6347 and then Has_Controlling_Result (Nam)
6348 and then Nkind (Parent (N)) = N_Object_Declaration
6350 -- Verify that none of the formals are controlling
6353 Call_OK : Boolean := False;
6357 F := First_Formal (Nam);
6358 while Present (F) loop
6359 if Is_Controlling_Formal (F) then
6368 Error_Msg_Warn := SPARK_Mode /= On;
6369 Error_Msg_N ("!cannot determine tag of result<<", N);
6370 Error_Msg_N ("\Program_Error [<<!", N);
6372 Make_Raise_Program_Error (Sloc (N),
6373 Reason => PE_Explicit_Raise));
6378 -- Check for calling a function with OUT or IN OUT parameter when the
6379 -- calling context (us right now) is not Ada 2012, so does not allow
6380 -- OUT or IN OUT parameters in function calls. Functions declared in
6381 -- a predefined unit are OK, as they may be called indirectly from a
6382 -- user-declared instantiation.
6384 if Ada_Version < Ada_2012
6385 and then Ekind (Nam) = E_Function
6386 and then Has_Out_Or_In_Out_Parameter (Nam)
6387 and then not In_Predefined_Unit (Nam)
6389 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6390 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6393 -- Check the dimensions of the actuals in the call. For function calls,
6394 -- propagate the dimensions from the returned type to N.
6396 Analyze_Dimension_Call (N, Nam);
6398 -- All done, evaluate call and deal with elaboration issues
6401 Check_Elab_Call (N);
6403 -- In GNATprove mode, expansion is disabled, but we want to inline some
6404 -- subprograms to facilitate formal verification. Indirect calls through
6405 -- a subprogram type or within a generic cannot be inlined. Inlining is
6406 -- performed only for calls subject to SPARK_Mode on.
6409 and then SPARK_Mode = On
6410 and then Is_Overloadable (Nam)
6411 and then not Inside_A_Generic
6413 Nam_UA := Ultimate_Alias (Nam);
6414 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6416 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6417 Body_Id := Corresponding_Body (Nam_Decl);
6419 -- Nothing to do if the subprogram is not eligible for inlining in
6422 if not Is_Inlined_Always (Nam_UA)
6423 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6427 -- Calls cannot be inlined inside assertions, as GNATprove treats
6428 -- assertions as logic expressions.
6430 elsif In_Assertion_Expr /= 0 then
6431 Error_Msg_NE ("info: no contextual analysis of &?", N, Nam);
6432 Error_Msg_N ("\call appears in assertion expression", N);
6433 Set_Is_Inlined_Always (Nam_UA, False);
6435 -- Calls cannot be inlined inside default expressions
6437 elsif In_Default_Expr then
6438 Error_Msg_NE ("info: no contextual analysis of &?", N, Nam);
6439 Error_Msg_N ("\call appears in default expression", N);
6440 Set_Is_Inlined_Always (Nam_UA, False);
6442 -- Inlining should not be performed during pre-analysis
6444 elsif Full_Analysis then
6446 -- With the one-pass inlining technique, a call cannot be
6447 -- inlined if the corresponding body has not been seen yet.
6449 if No (Body_Id) then
6451 ("info: no contextual analysis of & (body not seen yet)?",
6453 Set_Is_Inlined_Always (Nam_UA, False);
6455 -- Nothing to do if there is no body to inline, indicating that
6456 -- the subprogram is not suitable for inlining in GNATprove
6459 elsif No (Body_To_Inline (Nam_Decl)) then
6462 -- Calls cannot be inlined inside potentially unevaluated
6463 -- expressions, as this would create complex actions inside
6464 -- expressions, that are not handled by GNATprove.
6466 elsif Is_Potentially_Unevaluated (N) then
6467 Error_Msg_NE ("info: no contextual analysis of &?", N, Nam);
6469 ("\call appears in potentially unevaluated context", N);
6470 Set_Is_Inlined_Always (Nam_UA, False);
6472 -- Otherwise, inline the call
6475 Expand_Inlined_Call (N, Nam_UA, Nam);
6481 Warn_On_Overlapping_Actuals (Nam, N);
6484 -----------------------------
6485 -- Resolve_Case_Expression --
6486 -----------------------------
6488 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6493 Alt := First (Alternatives (N));
6494 while Present (Alt) loop
6495 Resolve (Expression (Alt), Typ);
6499 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6500 -- dynamically tagged must be known statically.
6502 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
6503 Alt := First (Alternatives (N));
6504 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
6506 while Present (Alt) loop
6507 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
6508 Error_Msg_N ("all or none of the dependent expressions "
6509 & "can be dynamically tagged", N);
6517 Eval_Case_Expression (N);
6518 end Resolve_Case_Expression;
6520 -------------------------------
6521 -- Resolve_Character_Literal --
6522 -------------------------------
6524 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6525 B_Typ : constant Entity_Id := Base_Type (Typ);
6529 -- Verify that the character does belong to the type of the context
6531 Set_Etype (N, B_Typ);
6532 Eval_Character_Literal (N);
6534 -- Wide_Wide_Character literals must always be defined, since the set
6535 -- of wide wide character literals is complete, i.e. if a character
6536 -- literal is accepted by the parser, then it is OK for wide wide
6537 -- character (out of range character literals are rejected).
6539 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6542 -- Always accept character literal for type Any_Character, which
6543 -- occurs in error situations and in comparisons of literals, both
6544 -- of which should accept all literals.
6546 elsif B_Typ = Any_Character then
6549 -- For Standard.Character or a type derived from it, check that the
6550 -- literal is in range.
6552 elsif Root_Type (B_Typ) = Standard_Character then
6553 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6557 -- For Standard.Wide_Character or a type derived from it, check that the
6558 -- literal is in range.
6560 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6561 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6565 -- For Standard.Wide_Wide_Character or a type derived from it, we
6566 -- know the literal is in range, since the parser checked.
6568 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6571 -- If the entity is already set, this has already been resolved in a
6572 -- generic context, or comes from expansion. Nothing else to do.
6574 elsif Present (Entity (N)) then
6577 -- Otherwise we have a user defined character type, and we can use the
6578 -- standard visibility mechanisms to locate the referenced entity.
6581 C := Current_Entity (N);
6582 while Present (C) loop
6583 if Etype (C) = B_Typ then
6584 Set_Entity_With_Checks (N, C);
6585 Generate_Reference (C, N);
6593 -- If we fall through, then the literal does not match any of the
6594 -- entries of the enumeration type. This isn't just a constraint error
6595 -- situation, it is an illegality (see RM 4.2).
6598 ("character not defined for }", N, First_Subtype (B_Typ));
6599 end Resolve_Character_Literal;
6601 ---------------------------
6602 -- Resolve_Comparison_Op --
6603 ---------------------------
6605 -- Context requires a boolean type, and plays no role in resolution.
6606 -- Processing identical to that for equality operators. The result type is
6607 -- the base type, which matters when pathological subtypes of booleans with
6608 -- limited ranges are used.
6610 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6611 L : constant Node_Id := Left_Opnd (N);
6612 R : constant Node_Id := Right_Opnd (N);
6616 -- If this is an intrinsic operation which is not predefined, use the
6617 -- types of its declared arguments to resolve the possibly overloaded
6618 -- operands. Otherwise the operands are unambiguous and specify the
6621 if Scope (Entity (N)) /= Standard_Standard then
6622 T := Etype (First_Entity (Entity (N)));
6625 T := Find_Unique_Type (L, R);
6627 if T = Any_Fixed then
6628 T := Unique_Fixed_Point_Type (L);
6632 Set_Etype (N, Base_Type (Typ));
6633 Generate_Reference (T, N, ' ');
6635 -- Skip remaining processing if already set to Any_Type
6637 if T = Any_Type then
6641 -- Deal with other error cases
6643 if T = Any_String or else
6644 T = Any_Composite or else
6647 if T = Any_Character then
6648 Ambiguous_Character (L);
6650 Error_Msg_N ("ambiguous operands for comparison", N);
6653 Set_Etype (N, Any_Type);
6657 -- Resolve the operands if types OK
6661 Check_Unset_Reference (L);
6662 Check_Unset_Reference (R);
6663 Generate_Operator_Reference (N, T);
6664 Check_Low_Bound_Tested (N);
6666 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6667 -- types or array types except String.
6669 if Is_Boolean_Type (T) then
6670 Check_SPARK_05_Restriction
6671 ("comparison is not defined on Boolean type", N);
6673 elsif Is_Array_Type (T)
6674 and then Base_Type (T) /= Standard_String
6676 Check_SPARK_05_Restriction
6677 ("comparison is not defined on array types other than String", N);
6680 -- Check comparison on unordered enumeration
6682 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6683 Error_Msg_Sloc := Sloc (Etype (L));
6685 ("comparison on unordered enumeration type& declared#?U?",
6689 -- Evaluate the relation (note we do this after the above check since
6690 -- this Eval call may change N to True/False.
6692 Analyze_Dimension (N);
6693 Eval_Relational_Op (N);
6694 end Resolve_Comparison_Op;
6696 -----------------------------------------
6697 -- Resolve_Discrete_Subtype_Indication --
6698 -----------------------------------------
6700 procedure Resolve_Discrete_Subtype_Indication
6708 Analyze (Subtype_Mark (N));
6709 S := Entity (Subtype_Mark (N));
6711 if Nkind (Constraint (N)) /= N_Range_Constraint then
6712 Error_Msg_N ("expect range constraint for discrete type", N);
6713 Set_Etype (N, Any_Type);
6716 R := Range_Expression (Constraint (N));
6724 if Base_Type (S) /= Base_Type (Typ) then
6726 ("expect subtype of }", N, First_Subtype (Typ));
6728 -- Rewrite the constraint as a range of Typ
6729 -- to allow compilation to proceed further.
6732 Rewrite (Low_Bound (R),
6733 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6734 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6735 Attribute_Name => Name_First));
6736 Rewrite (High_Bound (R),
6737 Make_Attribute_Reference (Sloc (High_Bound (R)),
6738 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6739 Attribute_Name => Name_First));
6743 Set_Etype (N, Etype (R));
6745 -- Additionally, we must check that the bounds are compatible
6746 -- with the given subtype, which might be different from the
6747 -- type of the context.
6749 Apply_Range_Check (R, S);
6751 -- ??? If the above check statically detects a Constraint_Error
6752 -- it replaces the offending bound(s) of the range R with a
6753 -- Constraint_Error node. When the itype which uses these bounds
6754 -- is frozen the resulting call to Duplicate_Subexpr generates
6755 -- a new temporary for the bounds.
6757 -- Unfortunately there are other itypes that are also made depend
6758 -- on these bounds, so when Duplicate_Subexpr is called they get
6759 -- a forward reference to the newly created temporaries and Gigi
6760 -- aborts on such forward references. This is probably sign of a
6761 -- more fundamental problem somewhere else in either the order of
6762 -- itype freezing or the way certain itypes are constructed.
6764 -- To get around this problem we call Remove_Side_Effects right
6765 -- away if either bounds of R are a Constraint_Error.
6768 L : constant Node_Id := Low_Bound (R);
6769 H : constant Node_Id := High_Bound (R);
6772 if Nkind (L) = N_Raise_Constraint_Error then
6773 Remove_Side_Effects (L);
6776 if Nkind (H) = N_Raise_Constraint_Error then
6777 Remove_Side_Effects (H);
6781 Check_Unset_Reference (Low_Bound (R));
6782 Check_Unset_Reference (High_Bound (R));
6785 end Resolve_Discrete_Subtype_Indication;
6787 -------------------------
6788 -- Resolve_Entity_Name --
6789 -------------------------
6791 -- Used to resolve identifiers and expanded names
6793 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6794 function Is_Assignment_Or_Object_Expression
6796 Expr : Node_Id) return Boolean;
6797 -- Determine whether node Context denotes an assignment statement or an
6798 -- object declaration whose expression is node Expr.
6800 function Is_OK_Volatile_Context
6802 Obj_Ref : Node_Id) return Boolean;
6803 -- Determine whether node Context denotes a "non-interfering context"
6804 -- (as defined in SPARK RM 7.1.3(12)) where volatile reference Obj_Ref
6805 -- can safely reside.
6807 ----------------------------------------
6808 -- Is_Assignment_Or_Object_Expression --
6809 ----------------------------------------
6811 function Is_Assignment_Or_Object_Expression
6813 Expr : Node_Id) return Boolean
6816 if Nkind_In (Context, N_Assignment_Statement,
6817 N_Object_Declaration)
6818 and then Expression (Context) = Expr
6822 -- Check whether a construct that yields a name is the expression of
6823 -- an assignment statement or an object declaration.
6825 elsif (Nkind_In (Context, N_Attribute_Reference,
6826 N_Explicit_Dereference,
6827 N_Indexed_Component,
6828 N_Selected_Component,
6830 and then Prefix (Context) = Expr)
6832 (Nkind_In (Context, N_Type_Conversion,
6833 N_Unchecked_Type_Conversion)
6834 and then Expression (Context) = Expr)
6837 Is_Assignment_Or_Object_Expression
6838 (Context => Parent (Context),
6841 -- Otherwise the context is not an assignment statement or an object
6847 end Is_Assignment_Or_Object_Expression;
6849 ----------------------------
6850 -- Is_OK_Volatile_Context --
6851 ----------------------------
6853 function Is_OK_Volatile_Context
6855 Obj_Ref : Node_Id) return Boolean
6857 function Is_Protected_Operation_Call (Nod : Node_Id) return Boolean;
6858 -- Determine whether an arbitrary node denotes a call to a protected
6859 -- entry, function or procedure in prefixed form where the prefix is
6862 function Within_Check (Nod : Node_Id) return Boolean;
6863 -- Determine whether an arbitrary node appears in a check node
6865 function Within_Subprogram_Call (Nod : Node_Id) return Boolean;
6866 -- Determine whether an arbitrary node appears in a procedure call
6868 function Within_Volatile_Function (Id : Entity_Id) return Boolean;
6869 -- Determine whether an arbitrary entity appears in a volatile
6872 ---------------------------------
6873 -- Is_Protected_Operation_Call --
6874 ---------------------------------
6876 function Is_Protected_Operation_Call (Nod : Node_Id) return Boolean is
6881 -- A call to a protected operations retains its selected component
6882 -- form as opposed to other prefixed calls that are transformed in
6885 if Nkind (Nod) = N_Selected_Component then
6886 Pref := Prefix (Nod);
6887 Subp := Selector_Name (Nod);
6891 and then Is_Protected_Type (Etype (Pref))
6892 and then Is_Entity_Name (Subp)
6893 and then Ekind_In (Entity (Subp), E_Entry,
6900 end Is_Protected_Operation_Call;
6906 function Within_Check (Nod : Node_Id) return Boolean is
6910 -- Climb the parent chain looking for a check node
6913 while Present (Par) loop
6914 if Nkind (Par) in N_Raise_xxx_Error then
6917 -- Prevent the search from going too far
6919 elsif Is_Body_Or_Package_Declaration (Par) then
6923 Par := Parent (Par);
6929 ----------------------------
6930 -- Within_Subprogram_Call --
6931 ----------------------------
6933 function Within_Subprogram_Call (Nod : Node_Id) return Boolean is
6937 -- Climb the parent chain looking for a function or procedure call
6940 while Present (Par) loop
6941 if Nkind_In (Par, N_Function_Call,
6942 N_Procedure_Call_Statement)
6946 -- Prevent the search from going too far
6948 elsif Is_Body_Or_Package_Declaration (Par) then
6952 Par := Parent (Par);
6956 end Within_Subprogram_Call;
6958 ------------------------------
6959 -- Within_Volatile_Function --
6960 ------------------------------
6962 function Within_Volatile_Function (Id : Entity_Id) return Boolean is
6963 Func_Id : Entity_Id;
6966 -- Traverse the scope stack looking for a [generic] function
6969 while Present (Func_Id) and then Func_Id /= Standard_Standard loop
6970 if Ekind_In (Func_Id, E_Function, E_Generic_Function) then
6971 return Is_Volatile_Function (Func_Id);
6974 Func_Id := Scope (Func_Id);
6978 end Within_Volatile_Function;
6984 -- Start of processing for Is_OK_Volatile_Context
6987 -- The volatile object appears on either side of an assignment
6989 if Nkind (Context) = N_Assignment_Statement then
6992 -- The volatile object is part of the initialization expression of
6995 elsif Nkind (Context) = N_Object_Declaration
6996 and then Present (Expression (Context))
6997 and then Expression (Context) = Obj_Ref
6999 Obj_Id := Defining_Entity (Context);
7001 -- The volatile object acts as the initialization expression of an
7002 -- extended return statement. This is valid context as long as the
7003 -- function is volatile.
7005 if Is_Return_Object (Obj_Id) then
7006 return Within_Volatile_Function (Obj_Id);
7008 -- Otherwise this is a normal object initialization
7014 -- The volatile object acts as the name of a renaming declaration
7016 elsif Nkind (Context) = N_Object_Renaming_Declaration
7017 and then Name (Context) = Obj_Ref
7021 -- The volatile object appears as an actual parameter in a call to an
7022 -- instance of Unchecked_Conversion whose result is renamed.
7024 elsif Nkind (Context) = N_Function_Call
7025 and then Is_Entity_Name (Name (Context))
7026 and then Is_Unchecked_Conversion_Instance (Entity (Name (Context)))
7027 and then Nkind (Parent (Context)) = N_Object_Renaming_Declaration
7031 -- The volatile object is actually the prefix in a protected entry,
7032 -- function, or procedure call.
7034 elsif Is_Protected_Operation_Call (Context) then
7037 -- The volatile object appears as the expression of a simple return
7038 -- statement that applies to a volatile function.
7040 elsif Nkind (Context) = N_Simple_Return_Statement
7041 and then Expression (Context) = Obj_Ref
7044 Within_Volatile_Function (Return_Statement_Entity (Context));
7046 -- The volatile object appears as the prefix of a name occurring
7047 -- in a non-interfering context.
7049 elsif Nkind_In (Context, N_Attribute_Reference,
7050 N_Explicit_Dereference,
7051 N_Indexed_Component,
7052 N_Selected_Component,
7054 and then Prefix (Context) = Obj_Ref
7055 and then Is_OK_Volatile_Context
7056 (Context => Parent (Context),
7061 -- The volatile object appears as the expression of a type conversion
7062 -- occurring in a non-interfering context.
7064 elsif Nkind_In (Context, N_Type_Conversion,
7065 N_Unchecked_Type_Conversion)
7066 and then Expression (Context) = Obj_Ref
7067 and then Is_OK_Volatile_Context
7068 (Context => Parent (Context),
7073 -- Allow references to volatile objects in various checks. This is
7074 -- not a direct SPARK 2014 requirement.
7076 elsif Within_Check (Context) then
7079 -- Assume that references to effectively volatile objects that appear
7080 -- as actual parameters in a subprogram call are always legal. A full
7081 -- legality check is done when the actuals are resolved.
7083 elsif Within_Subprogram_Call (Context) then
7086 -- Otherwise the context is not suitable for an effectively volatile
7092 end Is_OK_Volatile_Context;
7096 E : constant Entity_Id := Entity (N);
7099 -- Start of processing for Resolve_Entity_Name
7102 -- If garbage from errors, set to Any_Type and return
7104 if No (E) and then Total_Errors_Detected /= 0 then
7105 Set_Etype (N, Any_Type);
7109 -- Replace named numbers by corresponding literals. Note that this is
7110 -- the one case where Resolve_Entity_Name must reset the Etype, since
7111 -- it is currently marked as universal.
7113 if Ekind (E) = E_Named_Integer then
7115 Eval_Named_Integer (N);
7117 elsif Ekind (E) = E_Named_Real then
7119 Eval_Named_Real (N);
7121 -- For enumeration literals, we need to make sure that a proper style
7122 -- check is done, since such literals are overloaded, and thus we did
7123 -- not do a style check during the first phase of analysis.
7125 elsif Ekind (E) = E_Enumeration_Literal then
7126 Set_Entity_With_Checks (N, E);
7127 Eval_Entity_Name (N);
7129 -- Case of (sub)type name appearing in a context where an expression
7130 -- is expected. This is legal if occurrence is a current instance.
7131 -- See RM 8.6 (17/3).
7133 elsif Is_Type (E) then
7134 if Is_Current_Instance (N) then
7137 -- Any other use is an error
7141 ("invalid use of subtype mark in expression or call", N);
7144 -- Check discriminant use if entity is discriminant in current scope,
7145 -- i.e. discriminant of record or concurrent type currently being
7146 -- analyzed. Uses in corresponding body are unrestricted.
7148 elsif Ekind (E) = E_Discriminant
7149 and then Scope (E) = Current_Scope
7150 and then not Has_Completion (Current_Scope)
7152 Check_Discriminant_Use (N);
7154 -- A parameterless generic function cannot appear in a context that
7155 -- requires resolution.
7157 elsif Ekind (E) = E_Generic_Function then
7158 Error_Msg_N ("illegal use of generic function", N);
7160 -- In Ada 83 an OUT parameter cannot be read
7162 elsif Ekind (E) = E_Out_Parameter
7163 and then (Nkind (Parent (N)) in N_Op
7164 or else Nkind (Parent (N)) = N_Explicit_Dereference
7165 or else Is_Assignment_Or_Object_Expression
7166 (Context => Parent (N),
7169 if Ada_Version = Ada_83 then
7170 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7173 -- In all other cases, just do the possible static evaluation
7176 -- A deferred constant that appears in an expression must have a
7177 -- completion, unless it has been removed by in-place expansion of
7178 -- an aggregate. A constant that is a renaming does not need
7181 if Ekind (E) = E_Constant
7182 and then Comes_From_Source (E)
7183 and then No (Constant_Value (E))
7184 and then Is_Frozen (Etype (E))
7185 and then not In_Spec_Expression
7186 and then not Is_Imported (E)
7187 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7189 if No_Initialization (Parent (E))
7190 or else (Present (Full_View (E))
7191 and then No_Initialization (Parent (Full_View (E))))
7196 "deferred constant is frozen before completion", N);
7200 Eval_Entity_Name (N);
7205 -- When the entity appears in a parameter association, retrieve the
7206 -- related subprogram call.
7208 if Nkind (Par) = N_Parameter_Association then
7209 Par := Parent (Par);
7212 if Comes_From_Source (N) then
7214 -- The following checks are only relevant when SPARK_Mode is on as
7215 -- they are not standard Ada legality rules.
7217 if SPARK_Mode = On then
7219 -- An effectively volatile object subject to enabled properties
7220 -- Async_Writers or Effective_Reads must appear in non-interfering
7221 -- context (SPARK RM 7.1.3(12)).
7224 and then Is_Effectively_Volatile (E)
7225 and then (Async_Writers_Enabled (E)
7226 or else Effective_Reads_Enabled (E))
7227 and then not Is_OK_Volatile_Context (Par, N)
7230 ("volatile object cannot appear in this context "
7231 & "(SPARK RM 7.1.3(12))", N);
7234 -- Check for possible elaboration issues with respect to reads of
7235 -- variables. The act of renaming the variable is not considered a
7236 -- read as it simply establishes an alias.
7238 if Ekind (E) = E_Variable
7239 and then Nkind (Par) /= N_Object_Renaming_Declaration
7241 Check_Elab_Call (N);
7245 -- A Ghost entity must appear in a specific context
7247 if Is_Ghost_Entity (E) then
7248 Check_Ghost_Context (E, N);
7251 end Resolve_Entity_Name;
7257 procedure Resolve_Entry (Entry_Name : Node_Id) is
7258 Loc : constant Source_Ptr := Sloc (Entry_Name);
7266 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7267 -- If the bounds of the entry family being called depend on task
7268 -- discriminants, build a new index subtype where a discriminant is
7269 -- replaced with the value of the discriminant of the target task.
7270 -- The target task is the prefix of the entry name in the call.
7272 -----------------------
7273 -- Actual_Index_Type --
7274 -----------------------
7276 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7277 Typ : constant Entity_Id := Entry_Index_Type (E);
7278 Tsk : constant Entity_Id := Scope (E);
7279 Lo : constant Node_Id := Type_Low_Bound (Typ);
7280 Hi : constant Node_Id := Type_High_Bound (Typ);
7283 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7284 -- If the bound is given by a discriminant, replace with a reference
7285 -- to the discriminant of the same name in the target task. If the
7286 -- entry name is the target of a requeue statement and the entry is
7287 -- in the current protected object, the bound to be used is the
7288 -- discriminal of the object (see Apply_Range_Checks for details of
7289 -- the transformation).
7291 -----------------------------
7292 -- Actual_Discriminant_Ref --
7293 -----------------------------
7295 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7296 Typ : constant Entity_Id := Etype (Bound);
7300 Remove_Side_Effects (Bound);
7302 if not Is_Entity_Name (Bound)
7303 or else Ekind (Entity (Bound)) /= E_Discriminant
7307 elsif Is_Protected_Type (Tsk)
7308 and then In_Open_Scopes (Tsk)
7309 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7311 -- Note: here Bound denotes a discriminant of the corresponding
7312 -- record type tskV, whose discriminal is a formal of the
7313 -- init-proc tskVIP. What we want is the body discriminal,
7314 -- which is associated to the discriminant of the original
7315 -- concurrent type tsk.
7317 return New_Occurrence_Of
7318 (Find_Body_Discriminal (Entity (Bound)), Loc);
7322 Make_Selected_Component (Loc,
7323 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7324 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7329 end Actual_Discriminant_Ref;
7331 -- Start of processing for Actual_Index_Type
7334 if not Has_Discriminants (Tsk)
7335 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7337 return Entry_Index_Type (E);
7340 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7341 Set_Etype (New_T, Base_Type (Typ));
7342 Set_Size_Info (New_T, Typ);
7343 Set_RM_Size (New_T, RM_Size (Typ));
7344 Set_Scalar_Range (New_T,
7345 Make_Range (Sloc (Entry_Name),
7346 Low_Bound => Actual_Discriminant_Ref (Lo),
7347 High_Bound => Actual_Discriminant_Ref (Hi)));
7351 end Actual_Index_Type;
7353 -- Start of processing for Resolve_Entry
7356 -- Find name of entry being called, and resolve prefix of name with its
7357 -- own type. The prefix can be overloaded, and the name and signature of
7358 -- the entry must be taken into account.
7360 if Nkind (Entry_Name) = N_Indexed_Component then
7362 -- Case of dealing with entry family within the current tasks
7364 E_Name := Prefix (Entry_Name);
7367 E_Name := Entry_Name;
7370 if Is_Entity_Name (E_Name) then
7372 -- Entry call to an entry (or entry family) in the current task. This
7373 -- is legal even though the task will deadlock. Rewrite as call to
7376 -- This can also be a call to an entry in an enclosing task. If this
7377 -- is a single task, we have to retrieve its name, because the scope
7378 -- of the entry is the task type, not the object. If the enclosing
7379 -- task is a task type, the identity of the task is given by its own
7382 -- Finally this can be a requeue on an entry of the same task or
7383 -- protected object.
7385 S := Scope (Entity (E_Name));
7387 for J in reverse 0 .. Scope_Stack.Last loop
7388 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7389 and then not Comes_From_Source (S)
7391 -- S is an enclosing task or protected object. The concurrent
7392 -- declaration has been converted into a type declaration, and
7393 -- the object itself has an object declaration that follows
7394 -- the type in the same declarative part.
7396 Tsk := Next_Entity (S);
7397 while Etype (Tsk) /= S loop
7404 elsif S = Scope_Stack.Table (J).Entity then
7406 -- Call to current task. Will be transformed into call to Self
7414 Make_Selected_Component (Loc,
7415 Prefix => New_Occurrence_Of (S, Loc),
7417 New_Occurrence_Of (Entity (E_Name), Loc));
7418 Rewrite (E_Name, New_N);
7421 elsif Nkind (Entry_Name) = N_Selected_Component
7422 and then Is_Overloaded (Prefix (Entry_Name))
7424 -- Use the entry name (which must be unique at this point) to find
7425 -- the prefix that returns the corresponding task/protected type.
7428 Pref : constant Node_Id := Prefix (Entry_Name);
7429 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7434 Get_First_Interp (Pref, I, It);
7435 while Present (It.Typ) loop
7436 if Scope (Ent) = It.Typ then
7437 Set_Etype (Pref, It.Typ);
7441 Get_Next_Interp (I, It);
7446 if Nkind (Entry_Name) = N_Selected_Component then
7447 Resolve (Prefix (Entry_Name));
7449 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7450 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7451 Resolve (Prefix (Prefix (Entry_Name)));
7452 Index := First (Expressions (Entry_Name));
7453 Resolve (Index, Entry_Index_Type (Nam));
7455 -- Up to this point the expression could have been the actual in a
7456 -- simple entry call, and be given by a named association.
7458 if Nkind (Index) = N_Parameter_Association then
7459 Error_Msg_N ("expect expression for entry index", Index);
7461 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7466 ------------------------
7467 -- Resolve_Entry_Call --
7468 ------------------------
7470 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7471 Entry_Name : constant Node_Id := Name (N);
7472 Loc : constant Source_Ptr := Sloc (Entry_Name);
7474 First_Named : Node_Id;
7481 -- We kill all checks here, because it does not seem worth the effort to
7482 -- do anything better, an entry call is a big operation.
7486 -- Processing of the name is similar for entry calls and protected
7487 -- operation calls. Once the entity is determined, we can complete
7488 -- the resolution of the actuals.
7490 -- The selector may be overloaded, in the case of a protected object
7491 -- with overloaded functions. The type of the context is used for
7494 if Nkind (Entry_Name) = N_Selected_Component
7495 and then Is_Overloaded (Selector_Name (Entry_Name))
7496 and then Typ /= Standard_Void_Type
7503 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7504 while Present (It.Typ) loop
7505 if Covers (Typ, It.Typ) then
7506 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7507 Set_Etype (Entry_Name, It.Typ);
7509 Generate_Reference (It.Typ, N, ' ');
7512 Get_Next_Interp (I, It);
7517 Resolve_Entry (Entry_Name);
7519 if Nkind (Entry_Name) = N_Selected_Component then
7521 -- Simple entry call
7523 Nam := Entity (Selector_Name (Entry_Name));
7524 Obj := Prefix (Entry_Name);
7525 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7527 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7529 -- Call to member of entry family
7531 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7532 Obj := Prefix (Prefix (Entry_Name));
7533 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7536 -- We cannot in general check the maximum depth of protected entry calls
7537 -- at compile time. But we can tell that any protected entry call at all
7538 -- violates a specified nesting depth of zero.
7540 if Is_Protected_Type (Scope (Nam)) then
7541 Check_Restriction (Max_Entry_Queue_Length, N);
7544 -- Use context type to disambiguate a protected function that can be
7545 -- called without actuals and that returns an array type, and where the
7546 -- argument list may be an indexing of the returned value.
7548 if Ekind (Nam) = E_Function
7549 and then Needs_No_Actuals (Nam)
7550 and then Present (Parameter_Associations (N))
7552 ((Is_Array_Type (Etype (Nam))
7553 and then Covers (Typ, Component_Type (Etype (Nam))))
7555 or else (Is_Access_Type (Etype (Nam))
7556 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7560 Component_Type (Designated_Type (Etype (Nam))))))
7563 Index_Node : Node_Id;
7567 Make_Indexed_Component (Loc,
7569 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7570 Expressions => Parameter_Associations (N));
7572 -- Since we are correcting a node classification error made by the
7573 -- parser, we call Replace rather than Rewrite.
7575 Replace (N, Index_Node);
7576 Set_Etype (Prefix (N), Etype (Nam));
7578 Resolve_Indexed_Component (N, Typ);
7583 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7584 and then Present (Contract_Wrapper (Nam))
7585 and then Current_Scope /= Contract_Wrapper (Nam)
7587 -- Rewrite as call to the precondition wrapper, adding the task
7588 -- object to the list of actuals. If the call is to a member of an
7589 -- entry family, include the index as well.
7593 New_Actuals : List_Id;
7596 New_Actuals := New_List (Obj);
7598 if Nkind (Entry_Name) = N_Indexed_Component then
7599 Append_To (New_Actuals,
7600 New_Copy_Tree (First (Expressions (Entry_Name))));
7603 Append_List (Parameter_Associations (N), New_Actuals);
7605 Make_Procedure_Call_Statement (Loc,
7607 New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
7608 Parameter_Associations => New_Actuals);
7609 Rewrite (N, New_Call);
7611 -- Preanalyze and resolve new call. Current procedure is called
7612 -- from Resolve_Call, after which expansion will take place.
7614 Preanalyze_And_Resolve (N);
7619 -- The operation name may have been overloaded. Order the actuals
7620 -- according to the formals of the resolved entity, and set the return
7621 -- type to that of the operation.
7624 Normalize_Actuals (N, Nam, False, Norm_OK);
7625 pragma Assert (Norm_OK);
7626 Set_Etype (N, Etype (Nam));
7629 Resolve_Actuals (N, Nam);
7630 Check_Internal_Protected_Use (N, Nam);
7632 -- Create a call reference to the entry
7634 Generate_Reference (Nam, Entry_Name, 's');
7636 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7637 Check_Potentially_Blocking_Operation (N);
7640 -- Verify that a procedure call cannot masquerade as an entry
7641 -- call where an entry call is expected.
7643 if Ekind (Nam) = E_Procedure then
7644 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7645 and then N = Entry_Call_Statement (Parent (N))
7647 Error_Msg_N ("entry call required in select statement", N);
7649 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7650 and then N = Triggering_Statement (Parent (N))
7652 Error_Msg_N ("triggering statement cannot be procedure call", N);
7654 elsif Ekind (Scope (Nam)) = E_Task_Type
7655 and then not In_Open_Scopes (Scope (Nam))
7657 Error_Msg_N ("task has no entry with this name", Entry_Name);
7661 -- After resolution, entry calls and protected procedure calls are
7662 -- changed into entry calls, for expansion. The structure of the node
7663 -- does not change, so it can safely be done in place. Protected
7664 -- function calls must keep their structure because they are
7667 if Ekind (Nam) /= E_Function then
7669 -- A protected operation that is not a function may modify the
7670 -- corresponding object, and cannot apply to a constant. If this
7671 -- is an internal call, the prefix is the type itself.
7673 if Is_Protected_Type (Scope (Nam))
7674 and then not Is_Variable (Obj)
7675 and then (not Is_Entity_Name (Obj)
7676 or else not Is_Type (Entity (Obj)))
7679 ("prefix of protected procedure or entry call must be variable",
7683 Actuals := Parameter_Associations (N);
7684 First_Named := First_Named_Actual (N);
7687 Make_Entry_Call_Statement (Loc,
7689 Parameter_Associations => Actuals));
7691 Set_First_Named_Actual (N, First_Named);
7692 Set_Analyzed (N, True);
7694 -- Protected functions can return on the secondary stack, in which
7695 -- case we must trigger the transient scope mechanism.
7697 elsif Expander_Active
7698 and then Requires_Transient_Scope (Etype (Nam))
7700 Establish_Transient_Scope (N, Sec_Stack => True);
7702 end Resolve_Entry_Call;
7704 -------------------------
7705 -- Resolve_Equality_Op --
7706 -------------------------
7708 -- Both arguments must have the same type, and the boolean context does
7709 -- not participate in the resolution. The first pass verifies that the
7710 -- interpretation is not ambiguous, and the type of the left argument is
7711 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7712 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7713 -- though they carry a single (universal) type. Diagnose this case here.
7715 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7716 L : constant Node_Id := Left_Opnd (N);
7717 R : constant Node_Id := Right_Opnd (N);
7718 T : Entity_Id := Find_Unique_Type (L, R);
7720 procedure Check_If_Expression (Cond : Node_Id);
7721 -- The resolution rule for if expressions requires that each such must
7722 -- have a unique type. This means that if several dependent expressions
7723 -- are of a non-null anonymous access type, and the context does not
7724 -- impose an expected type (as can be the case in an equality operation)
7725 -- the expression must be rejected.
7727 procedure Explain_Redundancy (N : Node_Id);
7728 -- Attempt to explain the nature of a redundant comparison with True. If
7729 -- the expression N is too complex, this routine issues a general error
7732 function Find_Unique_Access_Type return Entity_Id;
7733 -- In the case of allocators and access attributes, the context must
7734 -- provide an indication of the specific access type to be used. If
7735 -- one operand is of such a "generic" access type, check whether there
7736 -- is a specific visible access type that has the same designated type.
7737 -- This is semantically dubious, and of no interest to any real code,
7738 -- but c48008a makes it all worthwhile.
7740 -------------------------
7741 -- Check_If_Expression --
7742 -------------------------
7744 procedure Check_If_Expression (Cond : Node_Id) is
7745 Then_Expr : Node_Id;
7746 Else_Expr : Node_Id;
7749 if Nkind (Cond) = N_If_Expression then
7750 Then_Expr := Next (First (Expressions (Cond)));
7751 Else_Expr := Next (Then_Expr);
7753 if Nkind (Then_Expr) /= N_Null
7754 and then Nkind (Else_Expr) /= N_Null
7756 Error_Msg_N ("cannot determine type of if expression", Cond);
7759 end Check_If_Expression;
7761 ------------------------
7762 -- Explain_Redundancy --
7763 ------------------------
7765 procedure Explain_Redundancy (N : Node_Id) is
7773 -- Strip the operand down to an entity
7776 if Nkind (Val) = N_Selected_Component then
7777 Val := Selector_Name (Val);
7783 -- The construct denotes an entity
7785 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7786 Val_Id := Entity (Val);
7788 -- Do not generate an error message when the comparison is done
7789 -- against the enumeration literal Standard.True.
7791 if Ekind (Val_Id) /= E_Enumeration_Literal then
7793 -- Build a customized error message
7796 Add_Str_To_Name_Buffer ("?r?");
7798 if Ekind (Val_Id) = E_Component then
7799 Add_Str_To_Name_Buffer ("component ");
7801 elsif Ekind (Val_Id) = E_Constant then
7802 Add_Str_To_Name_Buffer ("constant ");
7804 elsif Ekind (Val_Id) = E_Discriminant then
7805 Add_Str_To_Name_Buffer ("discriminant ");
7807 elsif Is_Formal (Val_Id) then
7808 Add_Str_To_Name_Buffer ("parameter ");
7810 elsif Ekind (Val_Id) = E_Variable then
7811 Add_Str_To_Name_Buffer ("variable ");
7814 Add_Str_To_Name_Buffer ("& is always True!");
7817 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7820 -- The construct is too complex to disect, issue a general message
7823 Error_Msg_N ("?r?expression is always True!", Val);
7825 end Explain_Redundancy;
7827 -----------------------------
7828 -- Find_Unique_Access_Type --
7829 -----------------------------
7831 function Find_Unique_Access_Type return Entity_Id is
7837 if Ekind_In (Etype (R), E_Allocator_Type,
7838 E_Access_Attribute_Type)
7840 Acc := Designated_Type (Etype (R));
7842 elsif Ekind_In (Etype (L), E_Allocator_Type,
7843 E_Access_Attribute_Type)
7845 Acc := Designated_Type (Etype (L));
7851 while S /= Standard_Standard loop
7852 E := First_Entity (S);
7853 while Present (E) loop
7855 and then Is_Access_Type (E)
7856 and then Ekind (E) /= E_Allocator_Type
7857 and then Designated_Type (E) = Base_Type (Acc)
7869 end Find_Unique_Access_Type;
7871 -- Start of processing for Resolve_Equality_Op
7874 Set_Etype (N, Base_Type (Typ));
7875 Generate_Reference (T, N, ' ');
7877 if T = Any_Fixed then
7878 T := Unique_Fixed_Point_Type (L);
7881 if T /= Any_Type then
7882 if T = Any_String or else
7883 T = Any_Composite or else
7886 if T = Any_Character then
7887 Ambiguous_Character (L);
7889 Error_Msg_N ("ambiguous operands for equality", N);
7892 Set_Etype (N, Any_Type);
7895 elsif T = Any_Access
7896 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7898 T := Find_Unique_Access_Type;
7901 Error_Msg_N ("ambiguous operands for equality", N);
7902 Set_Etype (N, Any_Type);
7906 -- If expressions must have a single type, and if the context does
7907 -- not impose one the dependent expressions cannot be anonymous
7910 -- Why no similar processing for case expressions???
7912 elsif Ada_Version >= Ada_2012
7913 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7914 E_Anonymous_Access_Subprogram_Type)
7915 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7916 E_Anonymous_Access_Subprogram_Type)
7918 Check_If_Expression (L);
7919 Check_If_Expression (R);
7925 -- In SPARK, equality operators = and /= for array types other than
7926 -- String are only defined when, for each index position, the
7927 -- operands have equal static bounds.
7929 if Is_Array_Type (T) then
7931 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7932 -- operation if not needed.
7934 if Restriction_Check_Required (SPARK_05)
7935 and then Base_Type (T) /= Standard_String
7936 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7937 and then Etype (L) /= Any_Composite -- or else L in error
7938 and then Etype (R) /= Any_Composite -- or else R in error
7939 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7941 Check_SPARK_05_Restriction
7942 ("array types should have matching static bounds", N);
7946 -- If the unique type is a class-wide type then it will be expanded
7947 -- into a dispatching call to the predefined primitive. Therefore we
7948 -- check here for potential violation of such restriction.
7950 if Is_Class_Wide_Type (T) then
7951 Check_Restriction (No_Dispatching_Calls, N);
7954 if Warn_On_Redundant_Constructs
7955 and then Comes_From_Source (N)
7956 and then Comes_From_Source (R)
7957 and then Is_Entity_Name (R)
7958 and then Entity (R) = Standard_True
7960 Error_Msg_N -- CODEFIX
7961 ("?r?comparison with True is redundant!", N);
7962 Explain_Redundancy (Original_Node (R));
7965 Check_Unset_Reference (L);
7966 Check_Unset_Reference (R);
7967 Generate_Operator_Reference (N, T);
7968 Check_Low_Bound_Tested (N);
7970 -- If this is an inequality, it may be the implicit inequality
7971 -- created for a user-defined operation, in which case the corres-
7972 -- ponding equality operation is not intrinsic, and the operation
7973 -- cannot be constant-folded. Else fold.
7975 if Nkind (N) = N_Op_Eq
7976 or else Comes_From_Source (Entity (N))
7977 or else Ekind (Entity (N)) = E_Operator
7978 or else Is_Intrinsic_Subprogram
7979 (Corresponding_Equality (Entity (N)))
7981 Analyze_Dimension (N);
7982 Eval_Relational_Op (N);
7984 elsif Nkind (N) = N_Op_Ne
7985 and then Is_Abstract_Subprogram (Entity (N))
7987 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7990 -- Ada 2005: If one operand is an anonymous access type, convert the
7991 -- other operand to it, to ensure that the underlying types match in
7992 -- the back-end. Same for access_to_subprogram, and the conversion
7993 -- verifies that the types are subtype conformant.
7995 -- We apply the same conversion in the case one of the operands is a
7996 -- private subtype of the type of the other.
7998 -- Why the Expander_Active test here ???
8002 (Ekind_In (T, E_Anonymous_Access_Type,
8003 E_Anonymous_Access_Subprogram_Type)
8004 or else Is_Private_Type (T))
8006 if Etype (L) /= T then
8008 Make_Unchecked_Type_Conversion (Sloc (L),
8009 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
8010 Expression => Relocate_Node (L)));
8011 Analyze_And_Resolve (L, T);
8014 if (Etype (R)) /= T then
8016 Make_Unchecked_Type_Conversion (Sloc (R),
8017 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
8018 Expression => Relocate_Node (R)));
8019 Analyze_And_Resolve (R, T);
8023 end Resolve_Equality_Op;
8025 ----------------------------------
8026 -- Resolve_Explicit_Dereference --
8027 ----------------------------------
8029 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
8030 Loc : constant Source_Ptr := Sloc (N);
8032 P : constant Node_Id := Prefix (N);
8035 -- The candidate prefix type, if overloaded
8041 Check_Fully_Declared_Prefix (Typ, P);
8044 -- A useful optimization: check whether the dereference denotes an
8045 -- element of a container, and if so rewrite it as a call to the
8046 -- corresponding Element function.
8048 -- Disabled for now, on advice of ARG. A more restricted form of the
8049 -- predicate might be acceptable ???
8051 -- if Is_Container_Element (N) then
8055 if Is_Overloaded (P) then
8057 -- Use the context type to select the prefix that has the correct
8058 -- designated type. Keep the first match, which will be the inner-
8061 Get_First_Interp (P, I, It);
8063 while Present (It.Typ) loop
8064 if Is_Access_Type (It.Typ)
8065 and then Covers (Typ, Designated_Type (It.Typ))
8071 -- Remove access types that do not match, but preserve access
8072 -- to subprogram interpretations, in case a further dereference
8073 -- is needed (see below).
8075 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
8079 Get_Next_Interp (I, It);
8082 if Present (P_Typ) then
8084 Set_Etype (N, Designated_Type (P_Typ));
8087 -- If no interpretation covers the designated type of the prefix,
8088 -- this is the pathological case where not all implementations of
8089 -- the prefix allow the interpretation of the node as a call. Now
8090 -- that the expected type is known, Remove other interpretations
8091 -- from prefix, rewrite it as a call, and resolve again, so that
8092 -- the proper call node is generated.
8094 Get_First_Interp (P, I, It);
8095 while Present (It.Typ) loop
8096 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8100 Get_Next_Interp (I, It);
8104 Make_Function_Call (Loc,
8106 Make_Explicit_Dereference (Loc,
8108 Parameter_Associations => New_List);
8110 Save_Interps (N, New_N);
8112 Analyze_And_Resolve (N, Typ);
8116 -- If not overloaded, resolve P with its own type
8122 -- If the prefix might be null, add an access check
8124 if Is_Access_Type (Etype (P))
8125 and then not Can_Never_Be_Null (Etype (P))
8127 Apply_Access_Check (N);
8130 -- If the designated type is a packed unconstrained array type, and the
8131 -- explicit dereference is not in the context of an attribute reference,
8132 -- then we must compute and set the actual subtype, since it is needed
8133 -- by Gigi. The reason we exclude the attribute case is that this is
8134 -- handled fine by Gigi, and in fact we use such attributes to build the
8135 -- actual subtype. We also exclude generated code (which builds actual
8136 -- subtypes directly if they are needed).
8138 if Is_Array_Type (Etype (N))
8139 and then Is_Packed (Etype (N))
8140 and then not Is_Constrained (Etype (N))
8141 and then Nkind (Parent (N)) /= N_Attribute_Reference
8142 and then Comes_From_Source (N)
8144 Set_Etype (N, Get_Actual_Subtype (N));
8147 Analyze_Dimension (N);
8149 -- Note: No Eval processing is required for an explicit dereference,
8150 -- because such a name can never be static.
8152 end Resolve_Explicit_Dereference;
8154 -------------------------------------
8155 -- Resolve_Expression_With_Actions --
8156 -------------------------------------
8158 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8162 -- If N has no actions, and its expression has been constant folded,
8163 -- then rewrite N as just its expression. Note, we can't do this in
8164 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8165 -- Expression (N) to be expanded again.
8167 if Is_Empty_List (Actions (N))
8168 and then Compile_Time_Known_Value (Expression (N))
8170 Rewrite (N, Expression (N));
8172 end Resolve_Expression_With_Actions;
8174 ----------------------------------
8175 -- Resolve_Generalized_Indexing --
8176 ----------------------------------
8178 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8179 Indexing : constant Node_Id := Generalized_Indexing (N);
8185 -- In ASIS mode, propagate the information about the indexes back to
8186 -- to the original indexing node. The generalized indexing is either
8187 -- a function call, or a dereference of one. The actuals include the
8188 -- prefix of the original node, which is the container expression.
8191 Resolve (Indexing, Typ);
8192 Set_Etype (N, Etype (Indexing));
8193 Set_Is_Overloaded (N, False);
8196 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8198 Call := Prefix (Call);
8201 if Nkind (Call) = N_Function_Call then
8202 Indexes := Parameter_Associations (Call);
8203 Pref := Remove_Head (Indexes);
8204 Set_Expressions (N, Indexes);
8206 -- If expression is to be reanalyzed, reset Generalized_Indexing
8207 -- to recreate call node, as is the case when the expression is
8208 -- part of an expression function.
8210 if In_Spec_Expression then
8211 Set_Generalized_Indexing (N, Empty);
8214 Set_Prefix (N, Pref);
8218 Rewrite (N, Indexing);
8221 end Resolve_Generalized_Indexing;
8223 ---------------------------
8224 -- Resolve_If_Expression --
8225 ---------------------------
8227 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8228 Condition : constant Node_Id := First (Expressions (N));
8229 Then_Expr : constant Node_Id := Next (Condition);
8230 Else_Expr : Node_Id := Next (Then_Expr);
8231 Else_Typ : Entity_Id;
8232 Then_Typ : Entity_Id;
8235 Resolve (Condition, Any_Boolean);
8236 Resolve (Then_Expr, Typ);
8237 Then_Typ := Etype (Then_Expr);
8239 -- When the "then" expression is of a scalar subtype different from the
8240 -- result subtype, then insert a conversion to ensure the generation of
8241 -- a constraint check. The same is done for the else part below, again
8242 -- comparing subtypes rather than base types.
8244 if Is_Scalar_Type (Then_Typ)
8245 and then Then_Typ /= Typ
8247 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8248 Analyze_And_Resolve (Then_Expr, Typ);
8251 -- If ELSE expression present, just resolve using the determined type
8253 if Present (Else_Expr) then
8254 Resolve (Else_Expr, Typ);
8255 Else_Typ := Etype (Else_Expr);
8257 if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
8258 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8259 Analyze_And_Resolve (Else_Expr, Typ);
8261 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8262 -- dynamically tagged must be known statically.
8264 elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8265 if Is_Dynamically_Tagged (Then_Expr) /=
8266 Is_Dynamically_Tagged (Else_Expr)
8268 Error_Msg_N ("all or none of the dependent expressions "
8269 & "can be dynamically tagged", N);
8273 -- If no ELSE expression is present, root type must be Standard.Boolean
8274 -- and we provide a Standard.True result converted to the appropriate
8275 -- Boolean type (in case it is a derived boolean type).
8277 elsif Root_Type (Typ) = Standard_Boolean then
8279 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8280 Analyze_And_Resolve (Else_Expr, Typ);
8281 Append_To (Expressions (N), Else_Expr);
8284 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8285 Append_To (Expressions (N), Error);
8289 Eval_If_Expression (N);
8290 end Resolve_If_Expression;
8292 -------------------------------
8293 -- Resolve_Indexed_Component --
8294 -------------------------------
8296 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8297 Name : constant Node_Id := Prefix (N);
8299 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8303 if Present (Generalized_Indexing (N)) then
8304 Resolve_Generalized_Indexing (N, Typ);
8308 if Is_Overloaded (Name) then
8310 -- Use the context type to select the prefix that yields the correct
8316 I1 : Interp_Index := 0;
8317 P : constant Node_Id := Prefix (N);
8318 Found : Boolean := False;
8321 Get_First_Interp (P, I, It);
8322 while Present (It.Typ) loop
8323 if (Is_Array_Type (It.Typ)
8324 and then Covers (Typ, Component_Type (It.Typ)))
8325 or else (Is_Access_Type (It.Typ)
8326 and then Is_Array_Type (Designated_Type (It.Typ))
8330 Component_Type (Designated_Type (It.Typ))))
8333 It := Disambiguate (P, I1, I, Any_Type);
8335 if It = No_Interp then
8336 Error_Msg_N ("ambiguous prefix for indexing", N);
8342 Array_Type := It.Typ;
8348 Array_Type := It.Typ;
8353 Get_Next_Interp (I, It);
8358 Array_Type := Etype (Name);
8361 Resolve (Name, Array_Type);
8362 Array_Type := Get_Actual_Subtype_If_Available (Name);
8364 -- If prefix is access type, dereference to get real array type.
8365 -- Note: we do not apply an access check because the expander always
8366 -- introduces an explicit dereference, and the check will happen there.
8368 if Is_Access_Type (Array_Type) then
8369 Array_Type := Designated_Type (Array_Type);
8372 -- If name was overloaded, set component type correctly now
8373 -- If a misplaced call to an entry family (which has no index types)
8374 -- return. Error will be diagnosed from calling context.
8376 if Is_Array_Type (Array_Type) then
8377 Set_Etype (N, Component_Type (Array_Type));
8382 Index := First_Index (Array_Type);
8383 Expr := First (Expressions (N));
8385 -- The prefix may have resolved to a string literal, in which case its
8386 -- etype has a special representation. This is only possible currently
8387 -- if the prefix is a static concatenation, written in functional
8390 if Ekind (Array_Type) = E_String_Literal_Subtype then
8391 Resolve (Expr, Standard_Positive);
8394 while Present (Index) and Present (Expr) loop
8395 Resolve (Expr, Etype (Index));
8396 Check_Unset_Reference (Expr);
8398 if Is_Scalar_Type (Etype (Expr)) then
8399 Apply_Scalar_Range_Check (Expr, Etype (Index));
8401 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8409 Analyze_Dimension (N);
8411 -- Do not generate the warning on suspicious index if we are analyzing
8412 -- package Ada.Tags; otherwise we will report the warning with the
8413 -- Prims_Ptr field of the dispatch table.
8415 if Scope (Etype (Prefix (N))) = Standard_Standard
8417 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8420 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8421 Eval_Indexed_Component (N);
8424 -- If the array type is atomic, and the component is not atomic, then
8425 -- this is worth a warning, since we have a situation where the access
8426 -- to the component may cause extra read/writes of the atomic array
8427 -- object, or partial word accesses, which could be unexpected.
8429 if Nkind (N) = N_Indexed_Component
8430 and then Is_Atomic_Ref_With_Address (N)
8431 and then not (Has_Atomic_Components (Array_Type)
8432 or else (Is_Entity_Name (Prefix (N))
8433 and then Has_Atomic_Components
8434 (Entity (Prefix (N)))))
8435 and then not Is_Atomic (Component_Type (Array_Type))
8438 ("??access to non-atomic component of atomic array", Prefix (N));
8440 ("??\may cause unexpected accesses to atomic object", Prefix (N));
8442 end Resolve_Indexed_Component;
8444 -----------------------------
8445 -- Resolve_Integer_Literal --
8446 -----------------------------
8448 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8451 Eval_Integer_Literal (N);
8452 end Resolve_Integer_Literal;
8454 --------------------------------
8455 -- Resolve_Intrinsic_Operator --
8456 --------------------------------
8458 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8459 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8464 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8465 -- If the operand is a literal, it cannot be the expression in a
8466 -- conversion. Use a qualified expression instead.
8468 ---------------------
8469 -- Convert_Operand --
8470 ---------------------
8472 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8473 Loc : constant Source_Ptr := Sloc (Opnd);
8477 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8479 Make_Qualified_Expression (Loc,
8480 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8481 Expression => Relocate_Node (Opnd));
8485 Res := Unchecked_Convert_To (Btyp, Opnd);
8489 end Convert_Operand;
8491 -- Start of processing for Resolve_Intrinsic_Operator
8494 -- We must preserve the original entity in a generic setting, so that
8495 -- the legality of the operation can be verified in an instance.
8497 if not Expander_Active then
8502 while Scope (Op) /= Standard_Standard loop
8504 pragma Assert (Present (Op));
8508 Set_Is_Overloaded (N, False);
8510 -- If the result or operand types are private, rewrite with unchecked
8511 -- conversions on the operands and the result, to expose the proper
8512 -- underlying numeric type.
8514 if Is_Private_Type (Typ)
8515 or else Is_Private_Type (Etype (Left_Opnd (N)))
8516 or else Is_Private_Type (Etype (Right_Opnd (N)))
8518 Arg1 := Convert_Operand (Left_Opnd (N));
8520 if Nkind (N) = N_Op_Expon then
8521 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8523 Arg2 := Convert_Operand (Right_Opnd (N));
8526 if Nkind (Arg1) = N_Type_Conversion then
8527 Save_Interps (Left_Opnd (N), Expression (Arg1));
8530 if Nkind (Arg2) = N_Type_Conversion then
8531 Save_Interps (Right_Opnd (N), Expression (Arg2));
8534 Set_Left_Opnd (N, Arg1);
8535 Set_Right_Opnd (N, Arg2);
8537 Set_Etype (N, Btyp);
8538 Rewrite (N, Unchecked_Convert_To (Typ, N));
8541 elsif Typ /= Etype (Left_Opnd (N))
8542 or else Typ /= Etype (Right_Opnd (N))
8544 -- Add explicit conversion where needed, and save interpretations in
8545 -- case operands are overloaded.
8547 Arg1 := Convert_To (Typ, Left_Opnd (N));
8548 Arg2 := Convert_To (Typ, Right_Opnd (N));
8550 if Nkind (Arg1) = N_Type_Conversion then
8551 Save_Interps (Left_Opnd (N), Expression (Arg1));
8553 Save_Interps (Left_Opnd (N), Arg1);
8556 if Nkind (Arg2) = N_Type_Conversion then
8557 Save_Interps (Right_Opnd (N), Expression (Arg2));
8559 Save_Interps (Right_Opnd (N), Arg2);
8562 Rewrite (Left_Opnd (N), Arg1);
8563 Rewrite (Right_Opnd (N), Arg2);
8566 Resolve_Arithmetic_Op (N, Typ);
8569 Resolve_Arithmetic_Op (N, Typ);
8571 end Resolve_Intrinsic_Operator;
8573 --------------------------------------
8574 -- Resolve_Intrinsic_Unary_Operator --
8575 --------------------------------------
8577 procedure Resolve_Intrinsic_Unary_Operator
8581 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8587 while Scope (Op) /= Standard_Standard loop
8589 pragma Assert (Present (Op));
8594 if Is_Private_Type (Typ) then
8595 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8596 Save_Interps (Right_Opnd (N), Expression (Arg2));
8598 Set_Right_Opnd (N, Arg2);
8600 Set_Etype (N, Btyp);
8601 Rewrite (N, Unchecked_Convert_To (Typ, N));
8605 Resolve_Unary_Op (N, Typ);
8607 end Resolve_Intrinsic_Unary_Operator;
8609 ------------------------
8610 -- Resolve_Logical_Op --
8611 ------------------------
8613 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8617 Check_No_Direct_Boolean_Operators (N);
8619 -- Predefined operations on scalar types yield the base type. On the
8620 -- other hand, logical operations on arrays yield the type of the
8621 -- arguments (and the context).
8623 if Is_Array_Type (Typ) then
8626 B_Typ := Base_Type (Typ);
8629 -- The following test is required because the operands of the operation
8630 -- may be literals, in which case the resulting type appears to be
8631 -- compatible with a signed integer type, when in fact it is compatible
8632 -- only with modular types. If the context itself is universal, the
8633 -- operation is illegal.
8635 if not Valid_Boolean_Arg (Typ) then
8636 Error_Msg_N ("invalid context for logical operation", N);
8637 Set_Etype (N, Any_Type);
8640 elsif Typ = Any_Modular then
8642 ("no modular type available in this context", N);
8643 Set_Etype (N, Any_Type);
8646 elsif Is_Modular_Integer_Type (Typ)
8647 and then Etype (Left_Opnd (N)) = Universal_Integer
8648 and then Etype (Right_Opnd (N)) = Universal_Integer
8650 Check_For_Visible_Operator (N, B_Typ);
8653 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8654 -- is active and the result type is standard Boolean (do not mess with
8655 -- ops that return a nonstandard Boolean type, because something strange
8658 -- Note: you might expect this replacement to be done during expansion,
8659 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8660 -- is used, no part of the right operand of an "and" or "or" operator
8661 -- should be executed if the left operand would short-circuit the
8662 -- evaluation of the corresponding "and then" or "or else". If we left
8663 -- the replacement to expansion time, then run-time checks associated
8664 -- with such operands would be evaluated unconditionally, due to being
8665 -- before the condition prior to the rewriting as short-circuit forms
8666 -- during expansion.
8668 if Short_Circuit_And_Or
8669 and then B_Typ = Standard_Boolean
8670 and then Nkind_In (N, N_Op_And, N_Op_Or)
8672 -- Mark the corresponding putative SCO operator as truly a logical
8673 -- (and short-circuit) operator.
8675 if Generate_SCO and then Comes_From_Source (N) then
8676 Set_SCO_Logical_Operator (N);
8679 if Nkind (N) = N_Op_And then
8681 Make_And_Then (Sloc (N),
8682 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8683 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8684 Analyze_And_Resolve (N, B_Typ);
8686 -- Case of OR changed to OR ELSE
8690 Make_Or_Else (Sloc (N),
8691 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8692 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8693 Analyze_And_Resolve (N, B_Typ);
8696 -- Return now, since analysis of the rewritten ops will take care of
8697 -- other reference bookkeeping and expression folding.
8702 Resolve (Left_Opnd (N), B_Typ);
8703 Resolve (Right_Opnd (N), B_Typ);
8705 Check_Unset_Reference (Left_Opnd (N));
8706 Check_Unset_Reference (Right_Opnd (N));
8708 Set_Etype (N, B_Typ);
8709 Generate_Operator_Reference (N, B_Typ);
8710 Eval_Logical_Op (N);
8712 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8713 -- only when both operands have same static lower and higher bounds. Of
8714 -- course the types have to match, so only check if operands are
8715 -- compatible and the node itself has no errors.
8717 if Is_Array_Type (B_Typ)
8718 and then Nkind (N) in N_Binary_Op
8721 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8722 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8725 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8726 -- operation if not needed.
8728 if Restriction_Check_Required (SPARK_05)
8729 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8730 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8731 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8732 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8734 Check_SPARK_05_Restriction
8735 ("array types should have matching static bounds", N);
8739 end Resolve_Logical_Op;
8741 ---------------------------
8742 -- Resolve_Membership_Op --
8743 ---------------------------
8745 -- The context can only be a boolean type, and does not determine the
8746 -- arguments. Arguments should be unambiguous, but the preference rule for
8747 -- universal types applies.
8749 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8750 pragma Warnings (Off, Typ);
8752 L : constant Node_Id := Left_Opnd (N);
8753 R : constant Node_Id := Right_Opnd (N);
8756 procedure Resolve_Set_Membership;
8757 -- Analysis has determined a unique type for the left operand. Use it to
8758 -- resolve the disjuncts.
8760 ----------------------------
8761 -- Resolve_Set_Membership --
8762 ----------------------------
8764 procedure Resolve_Set_Membership is
8769 -- If the left operand is overloaded, find type compatible with not
8770 -- overloaded alternative of the right operand.
8772 if Is_Overloaded (L) then
8774 Alt := First (Alternatives (N));
8775 while Present (Alt) loop
8776 if not Is_Overloaded (Alt) then
8777 Ltyp := Intersect_Types (L, Alt);
8784 -- Unclear how to resolve expression if all alternatives are also
8788 Error_Msg_N ("ambiguous expression", N);
8797 Alt := First (Alternatives (N));
8798 while Present (Alt) loop
8800 -- Alternative is an expression, a range
8801 -- or a subtype mark.
8803 if not Is_Entity_Name (Alt)
8804 or else not Is_Type (Entity (Alt))
8806 Resolve (Alt, Ltyp);
8812 -- Check for duplicates for discrete case
8814 if Is_Discrete_Type (Ltyp) then
8821 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8825 -- Loop checking duplicates. This is quadratic, but giant sets
8826 -- are unlikely in this context so it's a reasonable choice.
8829 Alt := First (Alternatives (N));
8830 while Present (Alt) loop
8831 if Is_OK_Static_Expression (Alt)
8832 and then (Nkind_In (Alt, N_Integer_Literal,
8833 N_Character_Literal)
8834 or else Nkind (Alt) in N_Has_Entity)
8837 Alts (Nalts) := (Alt, Expr_Value (Alt));
8839 for J in 1 .. Nalts - 1 loop
8840 if Alts (J).Val = Alts (Nalts).Val then
8841 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8842 Error_Msg_N ("duplicate of value given#??", Alt);
8851 end Resolve_Set_Membership;
8853 -- Start of processing for Resolve_Membership_Op
8856 if L = Error or else R = Error then
8860 if Present (Alternatives (N)) then
8861 Resolve_Set_Membership;
8864 elsif not Is_Overloaded (R)
8866 (Etype (R) = Universal_Integer
8868 Etype (R) = Universal_Real)
8869 and then Is_Overloaded (L)
8873 -- Ada 2005 (AI-251): Support the following case:
8875 -- type I is interface;
8876 -- type T is tagged ...
8878 -- function Test (O : I'Class) is
8880 -- return O in T'Class.
8883 -- In this case we have nothing else to do. The membership test will be
8884 -- done at run time.
8886 elsif Ada_Version >= Ada_2005
8887 and then Is_Class_Wide_Type (Etype (L))
8888 and then Is_Interface (Etype (L))
8889 and then Is_Class_Wide_Type (Etype (R))
8890 and then not Is_Interface (Etype (R))
8894 T := Intersect_Types (L, R);
8897 -- If mixed-mode operations are present and operands are all literal,
8898 -- the only interpretation involves Duration, which is probably not
8899 -- the intention of the programmer.
8901 if T = Any_Fixed then
8902 T := Unique_Fixed_Point_Type (N);
8904 if T = Any_Type then
8910 Check_Unset_Reference (L);
8912 if Nkind (R) = N_Range
8913 and then not Is_Scalar_Type (T)
8915 Error_Msg_N ("scalar type required for range", R);
8918 if Is_Entity_Name (R) then
8919 Freeze_Expression (R);
8922 Check_Unset_Reference (R);
8925 -- Here after resolving membership operation
8929 Eval_Membership_Op (N);
8930 end Resolve_Membership_Op;
8936 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8937 Loc : constant Source_Ptr := Sloc (N);
8940 -- Handle restriction against anonymous null access values This
8941 -- restriction can be turned off using -gnatdj.
8943 -- Ada 2005 (AI-231): Remove restriction
8945 if Ada_Version < Ada_2005
8946 and then not Debug_Flag_J
8947 and then Ekind (Typ) = E_Anonymous_Access_Type
8948 and then Comes_From_Source (N)
8950 -- In the common case of a call which uses an explicitly null value
8951 -- for an access parameter, give specialized error message.
8953 if Nkind (Parent (N)) in N_Subprogram_Call then
8955 ("null is not allowed as argument for an access parameter", N);
8957 -- Standard message for all other cases (are there any?)
8961 ("null cannot be of an anonymous access type", N);
8965 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8966 -- assignment to a null-excluding object
8968 if Ada_Version >= Ada_2005
8969 and then Can_Never_Be_Null (Typ)
8970 and then Nkind (Parent (N)) = N_Assignment_Statement
8972 if not Inside_Init_Proc then
8974 (Compile_Time_Constraint_Error (N,
8975 "(Ada 2005) null not allowed in null-excluding objects??"),
8976 Make_Raise_Constraint_Error (Loc,
8977 Reason => CE_Access_Check_Failed));
8980 Make_Raise_Constraint_Error (Loc,
8981 Reason => CE_Access_Check_Failed));
8985 -- In a distributed context, null for a remote access to subprogram may
8986 -- need to be replaced with a special record aggregate. In this case,
8987 -- return after having done the transformation.
8989 if (Ekind (Typ) = E_Record_Type
8990 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8991 and then Remote_AST_Null_Value (N, Typ)
8996 -- The null literal takes its type from the context
9001 -----------------------
9002 -- Resolve_Op_Concat --
9003 -----------------------
9005 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
9007 -- We wish to avoid deep recursion, because concatenations are often
9008 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
9009 -- operands nonrecursively until we find something that is not a simple
9010 -- concatenation (A in this case). We resolve that, and then walk back
9011 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9012 -- to do the rest of the work at each level. The Parent pointers allow
9013 -- us to avoid recursion, and thus avoid running out of memory. See also
9014 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9020 -- The following code is equivalent to:
9022 -- Resolve_Op_Concat_First (NN, Typ);
9023 -- Resolve_Op_Concat_Arg (N, ...);
9024 -- Resolve_Op_Concat_Rest (N, Typ);
9026 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9027 -- operand is a concatenation.
9029 -- Walk down left operands
9032 Resolve_Op_Concat_First (NN, Typ);
9033 Op1 := Left_Opnd (NN);
9034 exit when not (Nkind (Op1) = N_Op_Concat
9035 and then not Is_Array_Type (Component_Type (Typ))
9036 and then Entity (Op1) = Entity (NN));
9040 -- Now (given the above example) NN is A&B and Op1 is A
9042 -- First resolve Op1 ...
9044 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
9046 -- ... then walk NN back up until we reach N (where we started), calling
9047 -- Resolve_Op_Concat_Rest along the way.
9050 Resolve_Op_Concat_Rest (NN, Typ);
9055 if Base_Type (Etype (N)) /= Standard_String then
9056 Check_SPARK_05_Restriction
9057 ("result of concatenation should have type String", N);
9059 end Resolve_Op_Concat;
9061 ---------------------------
9062 -- Resolve_Op_Concat_Arg --
9063 ---------------------------
9065 procedure Resolve_Op_Concat_Arg
9071 Btyp : constant Entity_Id := Base_Type (Typ);
9072 Ctyp : constant Entity_Id := Component_Type (Typ);
9077 or else (not Is_Overloaded (Arg)
9078 and then Etype (Arg) /= Any_Composite
9079 and then Covers (Ctyp, Etype (Arg)))
9081 Resolve (Arg, Ctyp);
9083 Resolve (Arg, Btyp);
9086 -- If both Array & Array and Array & Component are visible, there is a
9087 -- potential ambiguity that must be reported.
9089 elsif Has_Compatible_Type (Arg, Ctyp) then
9090 if Nkind (Arg) = N_Aggregate
9091 and then Is_Composite_Type (Ctyp)
9093 if Is_Private_Type (Ctyp) then
9094 Resolve (Arg, Btyp);
9096 -- If the operation is user-defined and not overloaded use its
9097 -- profile. The operation may be a renaming, in which case it has
9098 -- been rewritten, and we want the original profile.
9100 elsif not Is_Overloaded (N)
9101 and then Comes_From_Source (Entity (Original_Node (N)))
9102 and then Ekind (Entity (Original_Node (N))) = E_Function
9106 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9109 -- Otherwise an aggregate may match both the array type and the
9113 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9114 Set_Etype (Arg, Any_Type);
9118 if Is_Overloaded (Arg)
9119 and then Has_Compatible_Type (Arg, Typ)
9120 and then Etype (Arg) /= Any_Type
9128 Get_First_Interp (Arg, I, It);
9130 Get_Next_Interp (I, It);
9132 -- Special-case the error message when the overloading is
9133 -- caused by a function that yields an array and can be
9134 -- called without parameters.
9136 if It.Nam = Func then
9137 Error_Msg_Sloc := Sloc (Func);
9138 Error_Msg_N ("ambiguous call to function#", Arg);
9140 ("\\interpretation as call yields&", Arg, Typ);
9142 ("\\interpretation as indexing of call yields&",
9143 Arg, Component_Type (Typ));
9146 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9148 Get_First_Interp (Arg, I, It);
9149 while Present (It.Nam) loop
9150 Error_Msg_Sloc := Sloc (It.Nam);
9152 if Base_Type (It.Typ) = Btyp
9154 Base_Type (It.Typ) = Base_Type (Ctyp)
9156 Error_Msg_N -- CODEFIX
9157 ("\\possible interpretation#", Arg);
9160 Get_Next_Interp (I, It);
9166 Resolve (Arg, Component_Type (Typ));
9168 if Nkind (Arg) = N_String_Literal then
9169 Set_Etype (Arg, Component_Type (Typ));
9172 if Arg = Left_Opnd (N) then
9173 Set_Is_Component_Left_Opnd (N);
9175 Set_Is_Component_Right_Opnd (N);
9180 Resolve (Arg, Btyp);
9183 -- Concatenation is restricted in SPARK: each operand must be either a
9184 -- string literal, the name of a string constant, a static character or
9185 -- string expression, or another concatenation. Arg cannot be a
9186 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9187 -- separately on each final operand, past concatenation operations.
9189 if Is_Character_Type (Etype (Arg)) then
9190 if not Is_OK_Static_Expression (Arg) then
9191 Check_SPARK_05_Restriction
9192 ("character operand for concatenation should be static", Arg);
9195 elsif Is_String_Type (Etype (Arg)) then
9196 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9197 and then Is_Constant_Object (Entity (Arg)))
9198 and then not Is_OK_Static_Expression (Arg)
9200 Check_SPARK_05_Restriction
9201 ("string operand for concatenation should be static", Arg);
9204 -- Do not issue error on an operand that is neither a character nor a
9205 -- string, as the error is issued in Resolve_Op_Concat.
9211 Check_Unset_Reference (Arg);
9212 end Resolve_Op_Concat_Arg;
9214 -----------------------------
9215 -- Resolve_Op_Concat_First --
9216 -----------------------------
9218 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9219 Btyp : constant Entity_Id := Base_Type (Typ);
9220 Op1 : constant Node_Id := Left_Opnd (N);
9221 Op2 : constant Node_Id := Right_Opnd (N);
9224 -- The parser folds an enormous sequence of concatenations of string
9225 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9226 -- in the right operand. If the expression resolves to a predefined "&"
9227 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9228 -- we give an error. See P_Simple_Expression in Par.Ch4.
9230 if Nkind (Op2) = N_String_Literal
9231 and then Is_Folded_In_Parser (Op2)
9232 and then Ekind (Entity (N)) = E_Function
9234 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9235 and then String_Length (Strval (Op1)) = 0);
9236 Error_Msg_N ("too many user-defined concatenations", N);
9240 Set_Etype (N, Btyp);
9242 if Is_Limited_Composite (Btyp) then
9243 Error_Msg_N ("concatenation not available for limited array", N);
9244 Explain_Limited_Type (Btyp, N);
9246 end Resolve_Op_Concat_First;
9248 ----------------------------
9249 -- Resolve_Op_Concat_Rest --
9250 ----------------------------
9252 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9253 Op1 : constant Node_Id := Left_Opnd (N);
9254 Op2 : constant Node_Id := Right_Opnd (N);
9257 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9259 Generate_Operator_Reference (N, Typ);
9261 if Is_String_Type (Typ) then
9262 Eval_Concatenation (N);
9265 -- If this is not a static concatenation, but the result is a string
9266 -- type (and not an array of strings) ensure that static string operands
9267 -- have their subtypes properly constructed.
9269 if Nkind (N) /= N_String_Literal
9270 and then Is_Character_Type (Component_Type (Typ))
9272 Set_String_Literal_Subtype (Op1, Typ);
9273 Set_String_Literal_Subtype (Op2, Typ);
9275 end Resolve_Op_Concat_Rest;
9277 ----------------------
9278 -- Resolve_Op_Expon --
9279 ----------------------
9281 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9282 B_Typ : constant Entity_Id := Base_Type (Typ);
9285 -- Catch attempts to do fixed-point exponentiation with universal
9286 -- operands, which is a case where the illegality is not caught during
9287 -- normal operator analysis. This is not done in preanalysis mode
9288 -- since the tree is not fully decorated during preanalysis.
9290 if Full_Analysis then
9291 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9292 Error_Msg_N ("exponentiation not available for fixed point", N);
9295 elsif Nkind (Parent (N)) in N_Op
9296 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9297 and then Etype (N) = Universal_Real
9298 and then Comes_From_Source (N)
9300 Error_Msg_N ("exponentiation not available for fixed point", N);
9305 if Comes_From_Source (N)
9306 and then Ekind (Entity (N)) = E_Function
9307 and then Is_Imported (Entity (N))
9308 and then Is_Intrinsic_Subprogram (Entity (N))
9310 Resolve_Intrinsic_Operator (N, Typ);
9314 if Etype (Left_Opnd (N)) = Universal_Integer
9315 or else Etype (Left_Opnd (N)) = Universal_Real
9317 Check_For_Visible_Operator (N, B_Typ);
9320 -- We do the resolution using the base type, because intermediate values
9321 -- in expressions are always of the base type, not a subtype of it.
9323 Resolve (Left_Opnd (N), B_Typ);
9324 Resolve (Right_Opnd (N), Standard_Integer);
9326 -- For integer types, right argument must be in Natural range
9328 if Is_Integer_Type (Typ) then
9329 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9332 Check_Unset_Reference (Left_Opnd (N));
9333 Check_Unset_Reference (Right_Opnd (N));
9335 Set_Etype (N, B_Typ);
9336 Generate_Operator_Reference (N, B_Typ);
9338 Analyze_Dimension (N);
9340 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9341 -- Evaluate the exponentiation operator for dimensioned type
9343 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9348 -- Set overflow checking bit. Much cleverer code needed here eventually
9349 -- and perhaps the Resolve routines should be separated for the various
9350 -- arithmetic operations, since they will need different processing. ???
9352 if Nkind (N) in N_Op then
9353 if not Overflow_Checks_Suppressed (Etype (N)) then
9354 Enable_Overflow_Check (N);
9357 end Resolve_Op_Expon;
9359 --------------------
9360 -- Resolve_Op_Not --
9361 --------------------
9363 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9366 function Parent_Is_Boolean return Boolean;
9367 -- This function determines if the parent node is a boolean operator or
9368 -- operation (comparison op, membership test, or short circuit form) and
9369 -- the not in question is the left operand of this operation. Note that
9370 -- if the not is in parens, then false is returned.
9372 -----------------------
9373 -- Parent_Is_Boolean --
9374 -----------------------
9376 function Parent_Is_Boolean return Boolean is
9378 if Paren_Count (N) /= 0 then
9382 case Nkind (Parent (N)) is
9397 return Left_Opnd (Parent (N)) = N;
9403 end Parent_Is_Boolean;
9405 -- Start of processing for Resolve_Op_Not
9408 -- Predefined operations on scalar types yield the base type. On the
9409 -- other hand, logical operations on arrays yield the type of the
9410 -- arguments (and the context).
9412 if Is_Array_Type (Typ) then
9415 B_Typ := Base_Type (Typ);
9418 -- Straightforward case of incorrect arguments
9420 if not Valid_Boolean_Arg (Typ) then
9421 Error_Msg_N ("invalid operand type for operator&", N);
9422 Set_Etype (N, Any_Type);
9425 -- Special case of probable missing parens
9427 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9428 if Parent_Is_Boolean then
9430 ("operand of not must be enclosed in parentheses",
9434 ("no modular type available in this context", N);
9437 Set_Etype (N, Any_Type);
9440 -- OK resolution of NOT
9443 -- Warn if non-boolean types involved. This is a case like not a < b
9444 -- where a and b are modular, where we will get (not a) < b and most
9445 -- likely not (a < b) was intended.
9447 if Warn_On_Questionable_Missing_Parens
9448 and then not Is_Boolean_Type (Typ)
9449 and then Parent_Is_Boolean
9451 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9454 -- Warn on double negation if checking redundant constructs
9456 if Warn_On_Redundant_Constructs
9457 and then Comes_From_Source (N)
9458 and then Comes_From_Source (Right_Opnd (N))
9459 and then Root_Type (Typ) = Standard_Boolean
9460 and then Nkind (Right_Opnd (N)) = N_Op_Not
9462 Error_Msg_N ("redundant double negation?r?", N);
9465 -- Complete resolution and evaluation of NOT
9467 Resolve (Right_Opnd (N), B_Typ);
9468 Check_Unset_Reference (Right_Opnd (N));
9469 Set_Etype (N, B_Typ);
9470 Generate_Operator_Reference (N, B_Typ);
9475 -----------------------------
9476 -- Resolve_Operator_Symbol --
9477 -----------------------------
9479 -- Nothing to be done, all resolved already
9481 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9482 pragma Warnings (Off, N);
9483 pragma Warnings (Off, Typ);
9487 end Resolve_Operator_Symbol;
9489 ----------------------------------
9490 -- Resolve_Qualified_Expression --
9491 ----------------------------------
9493 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9494 pragma Warnings (Off, Typ);
9496 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9497 Expr : constant Node_Id := Expression (N);
9500 Resolve (Expr, Target_Typ);
9502 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9503 -- operation if not needed.
9505 if Restriction_Check_Required (SPARK_05)
9506 and then Is_Array_Type (Target_Typ)
9507 and then Is_Array_Type (Etype (Expr))
9508 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9509 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9511 Check_SPARK_05_Restriction
9512 ("array types should have matching static bounds", N);
9515 -- A qualified expression requires an exact match of the type, class-
9516 -- wide matching is not allowed. However, if the qualifying type is
9517 -- specific and the expression has a class-wide type, it may still be
9518 -- okay, since it can be the result of the expansion of a call to a
9519 -- dispatching function, so we also have to check class-wideness of the
9520 -- type of the expression's original node.
9522 if (Is_Class_Wide_Type (Target_Typ)
9524 (Is_Class_Wide_Type (Etype (Expr))
9525 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9526 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9528 Wrong_Type (Expr, Target_Typ);
9531 -- If the target type is unconstrained, then we reset the type of the
9532 -- result from the type of the expression. For other cases, the actual
9533 -- subtype of the expression is the target type.
9535 if Is_Composite_Type (Target_Typ)
9536 and then not Is_Constrained (Target_Typ)
9538 Set_Etype (N, Etype (Expr));
9541 Analyze_Dimension (N);
9542 Eval_Qualified_Expression (N);
9544 -- If we still have a qualified expression after the static evaluation,
9545 -- then apply a scalar range check if needed. The reason that we do this
9546 -- after the Eval call is that otherwise, the application of the range
9547 -- check may convert an illegal static expression and result in warning
9548 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9550 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9551 Apply_Scalar_Range_Check (Expr, Typ);
9553 end Resolve_Qualified_Expression;
9555 ------------------------------
9556 -- Resolve_Raise_Expression --
9557 ------------------------------
9559 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9561 if Typ = Raise_Type then
9562 Error_Msg_N ("cannot find unique type for raise expression", N);
9563 Set_Etype (N, Any_Type);
9567 end Resolve_Raise_Expression;
9573 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9574 L : constant Node_Id := Low_Bound (N);
9575 H : constant Node_Id := High_Bound (N);
9577 function First_Last_Ref return Boolean;
9578 -- Returns True if N is of the form X'First .. X'Last where X is the
9579 -- same entity for both attributes.
9581 --------------------
9582 -- First_Last_Ref --
9583 --------------------
9585 function First_Last_Ref return Boolean is
9586 Lorig : constant Node_Id := Original_Node (L);
9587 Horig : constant Node_Id := Original_Node (H);
9590 if Nkind (Lorig) = N_Attribute_Reference
9591 and then Nkind (Horig) = N_Attribute_Reference
9592 and then Attribute_Name (Lorig) = Name_First
9593 and then Attribute_Name (Horig) = Name_Last
9596 PL : constant Node_Id := Prefix (Lorig);
9597 PH : constant Node_Id := Prefix (Horig);
9599 if Is_Entity_Name (PL)
9600 and then Is_Entity_Name (PH)
9601 and then Entity (PL) = Entity (PH)
9611 -- Start of processing for Resolve_Range
9618 -- Check for inappropriate range on unordered enumeration type
9620 if Bad_Unordered_Enumeration_Reference (N, Typ)
9622 -- Exclude X'First .. X'Last if X is the same entity for both
9624 and then not First_Last_Ref
9626 Error_Msg_Sloc := Sloc (Typ);
9628 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9631 Check_Unset_Reference (L);
9632 Check_Unset_Reference (H);
9634 -- We have to check the bounds for being within the base range as
9635 -- required for a non-static context. Normally this is automatic and
9636 -- done as part of evaluating expressions, but the N_Range node is an
9637 -- exception, since in GNAT we consider this node to be a subexpression,
9638 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9639 -- this, but that would put the test on the main evaluation path for
9642 Check_Non_Static_Context (L);
9643 Check_Non_Static_Context (H);
9645 -- Check for an ambiguous range over character literals. This will
9646 -- happen with a membership test involving only literals.
9648 if Typ = Any_Character then
9649 Ambiguous_Character (L);
9650 Set_Etype (N, Any_Type);
9654 -- If bounds are static, constant-fold them, so size computations are
9655 -- identical between front-end and back-end. Do not perform this
9656 -- transformation while analyzing generic units, as type information
9657 -- would be lost when reanalyzing the constant node in the instance.
9659 if Is_Discrete_Type (Typ) and then Expander_Active then
9660 if Is_OK_Static_Expression (L) then
9661 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9664 if Is_OK_Static_Expression (H) then
9665 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9670 --------------------------
9671 -- Resolve_Real_Literal --
9672 --------------------------
9674 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9675 Actual_Typ : constant Entity_Id := Etype (N);
9678 -- Special processing for fixed-point literals to make sure that the
9679 -- value is an exact multiple of small where this is required. We skip
9680 -- this for the universal real case, and also for generic types.
9682 if Is_Fixed_Point_Type (Typ)
9683 and then Typ /= Universal_Fixed
9684 and then Typ /= Any_Fixed
9685 and then not Is_Generic_Type (Typ)
9688 Val : constant Ureal := Realval (N);
9689 Cintr : constant Ureal := Val / Small_Value (Typ);
9690 Cint : constant Uint := UR_Trunc (Cintr);
9691 Den : constant Uint := Norm_Den (Cintr);
9695 -- Case of literal is not an exact multiple of the Small
9699 -- For a source program literal for a decimal fixed-point type,
9700 -- this is statically illegal (RM 4.9(36)).
9702 if Is_Decimal_Fixed_Point_Type (Typ)
9703 and then Actual_Typ = Universal_Real
9704 and then Comes_From_Source (N)
9706 Error_Msg_N ("value has extraneous low order digits", N);
9709 -- Generate a warning if literal from source
9711 if Is_OK_Static_Expression (N)
9712 and then Warn_On_Bad_Fixed_Value
9715 ("?b?static fixed-point value is not a multiple of Small!",
9719 -- Replace literal by a value that is the exact representation
9720 -- of a value of the type, i.e. a multiple of the small value,
9721 -- by truncation, since Machine_Rounds is false for all GNAT
9722 -- fixed-point types (RM 4.9(38)).
9724 Stat := Is_OK_Static_Expression (N);
9726 Make_Real_Literal (Sloc (N),
9727 Realval => Small_Value (Typ) * Cint));
9729 Set_Is_Static_Expression (N, Stat);
9732 -- In all cases, set the corresponding integer field
9734 Set_Corresponding_Integer_Value (N, Cint);
9738 -- Now replace the actual type by the expected type as usual
9741 Eval_Real_Literal (N);
9742 end Resolve_Real_Literal;
9744 -----------------------
9745 -- Resolve_Reference --
9746 -----------------------
9748 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9749 P : constant Node_Id := Prefix (N);
9752 -- Replace general access with specific type
9754 if Ekind (Etype (N)) = E_Allocator_Type then
9755 Set_Etype (N, Base_Type (Typ));
9758 Resolve (P, Designated_Type (Etype (N)));
9760 -- If we are taking the reference of a volatile entity, then treat it as
9761 -- a potential modification of this entity. This is too conservative,
9762 -- but necessary because remove side effects can cause transformations
9763 -- of normal assignments into reference sequences that otherwise fail to
9764 -- notice the modification.
9766 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9767 Note_Possible_Modification (P, Sure => False);
9769 end Resolve_Reference;
9771 --------------------------------
9772 -- Resolve_Selected_Component --
9773 --------------------------------
9775 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9777 Comp1 : Entity_Id := Empty; -- prevent junk warning
9778 P : constant Node_Id := Prefix (N);
9779 S : constant Node_Id := Selector_Name (N);
9780 T : Entity_Id := Etype (P);
9782 I1 : Interp_Index := 0; -- prevent junk warning
9787 function Init_Component return Boolean;
9788 -- Check whether this is the initialization of a component within an
9789 -- init proc (by assignment or call to another init proc). If true,
9790 -- there is no need for a discriminant check.
9792 --------------------
9793 -- Init_Component --
9794 --------------------
9796 function Init_Component return Boolean is
9798 return Inside_Init_Proc
9799 and then Nkind (Prefix (N)) = N_Identifier
9800 and then Chars (Prefix (N)) = Name_uInit
9801 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9804 -- Start of processing for Resolve_Selected_Component
9807 if Is_Overloaded (P) then
9809 -- Use the context type to select the prefix that has a selector
9810 -- of the correct name and type.
9813 Get_First_Interp (P, I, It);
9815 Search : while Present (It.Typ) loop
9816 if Is_Access_Type (It.Typ) then
9817 T := Designated_Type (It.Typ);
9822 -- Locate selected component. For a private prefix the selector
9823 -- can denote a discriminant.
9825 if Is_Record_Type (T) or else Is_Private_Type (T) then
9827 -- The visible components of a class-wide type are those of
9830 if Is_Class_Wide_Type (T) then
9834 Comp := First_Entity (T);
9835 while Present (Comp) loop
9836 if Chars (Comp) = Chars (S)
9837 and then Covers (Typ, Etype (Comp))
9846 It := Disambiguate (P, I1, I, Any_Type);
9848 if It = No_Interp then
9850 ("ambiguous prefix for selected component", N);
9857 -- There may be an implicit dereference. Retrieve
9858 -- designated record type.
9860 if Is_Access_Type (It1.Typ) then
9861 T := Designated_Type (It1.Typ);
9866 if Scope (Comp1) /= T then
9868 -- Resolution chooses the new interpretation.
9869 -- Find the component with the right name.
9871 Comp1 := First_Entity (T);
9872 while Present (Comp1)
9873 and then Chars (Comp1) /= Chars (S)
9875 Comp1 := Next_Entity (Comp1);
9884 Comp := Next_Entity (Comp);
9888 Get_Next_Interp (I, It);
9891 -- There must be a legal interpretation at this point
9893 pragma Assert (Found);
9894 Resolve (P, It1.Typ);
9896 Set_Entity_With_Checks (S, Comp1);
9899 -- Resolve prefix with its type
9904 -- Generate cross-reference. We needed to wait until full overloading
9905 -- resolution was complete to do this, since otherwise we can't tell if
9906 -- we are an lvalue or not.
9908 if May_Be_Lvalue (N) then
9909 Generate_Reference (Entity (S), S, 'm');
9911 Generate_Reference (Entity (S), S, 'r');
9914 -- If prefix is an access type, the node will be transformed into an
9915 -- explicit dereference during expansion. The type of the node is the
9916 -- designated type of that of the prefix.
9918 if Is_Access_Type (Etype (P)) then
9919 T := Designated_Type (Etype (P));
9920 Check_Fully_Declared_Prefix (T, P);
9925 -- Set flag for expander if discriminant check required on a component
9926 -- appearing within a variant.
9928 if Has_Discriminants (T)
9929 and then Ekind (Entity (S)) = E_Component
9930 and then Present (Original_Record_Component (Entity (S)))
9931 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9933 Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
9934 and then not Discriminant_Checks_Suppressed (T)
9935 and then not Init_Component
9937 Set_Do_Discriminant_Check (N);
9940 if Ekind (Entity (S)) = E_Void then
9941 Error_Msg_N ("premature use of component", S);
9944 -- If the prefix is a record conversion, this may be a renamed
9945 -- discriminant whose bounds differ from those of the original
9946 -- one, so we must ensure that a range check is performed.
9948 if Nkind (P) = N_Type_Conversion
9949 and then Ekind (Entity (S)) = E_Discriminant
9950 and then Is_Discrete_Type (Typ)
9952 Set_Etype (N, Base_Type (Typ));
9955 -- Note: No Eval processing is required, because the prefix is of a
9956 -- record type, or protected type, and neither can possibly be static.
9958 -- If the record type is atomic, and the component is non-atomic, then
9959 -- this is worth a warning, since we have a situation where the access
9960 -- to the component may cause extra read/writes of the atomic array
9961 -- object, or partial word accesses, both of which may be unexpected.
9963 if Nkind (N) = N_Selected_Component
9964 and then Is_Atomic_Ref_With_Address (N)
9965 and then not Is_Atomic (Entity (S))
9966 and then not Is_Atomic (Etype (Entity (S)))
9969 ("??access to non-atomic component of atomic record",
9972 ("\??may cause unexpected accesses to atomic object",
9976 Analyze_Dimension (N);
9977 end Resolve_Selected_Component;
9983 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9984 B_Typ : constant Entity_Id := Base_Type (Typ);
9985 L : constant Node_Id := Left_Opnd (N);
9986 R : constant Node_Id := Right_Opnd (N);
9989 -- We do the resolution using the base type, because intermediate values
9990 -- in expressions always are of the base type, not a subtype of it.
9993 Resolve (R, Standard_Natural);
9995 Check_Unset_Reference (L);
9996 Check_Unset_Reference (R);
9998 Set_Etype (N, B_Typ);
9999 Generate_Operator_Reference (N, B_Typ);
10003 ---------------------------
10004 -- Resolve_Short_Circuit --
10005 ---------------------------
10007 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
10008 B_Typ : constant Entity_Id := Base_Type (Typ);
10009 L : constant Node_Id := Left_Opnd (N);
10010 R : constant Node_Id := Right_Opnd (N);
10013 -- Ensure all actions associated with the left operand (e.g.
10014 -- finalization of transient controlled objects) are fully evaluated
10015 -- locally within an expression with actions. This is particularly
10016 -- helpful for coverage analysis. However this should not happen in
10019 if Expander_Active then
10021 Reloc_L : constant Node_Id := Relocate_Node (L);
10023 Save_Interps (Old_N => L, New_N => Reloc_L);
10026 Make_Expression_With_Actions (Sloc (L),
10027 Actions => New_List,
10028 Expression => Reloc_L));
10030 -- Set Comes_From_Source on L to preserve warnings for unset
10033 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
10037 Resolve (L, B_Typ);
10038 Resolve (R, B_Typ);
10040 -- Check for issuing warning for always False assert/check, this happens
10041 -- when assertions are turned off, in which case the pragma Assert/Check
10042 -- was transformed into:
10044 -- if False and then <condition> then ...
10046 -- and we detect this pattern
10048 if Warn_On_Assertion_Failure
10049 and then Is_Entity_Name (R)
10050 and then Entity (R) = Standard_False
10051 and then Nkind (Parent (N)) = N_If_Statement
10052 and then Nkind (N) = N_And_Then
10053 and then Is_Entity_Name (L)
10054 and then Entity (L) = Standard_False
10057 Orig : constant Node_Id := Original_Node (Parent (N));
10060 -- Special handling of Asssert pragma
10062 if Nkind (Orig) = N_Pragma
10063 and then Pragma_Name (Orig) = Name_Assert
10066 Expr : constant Node_Id :=
10069 (First (Pragma_Argument_Associations (Orig))));
10072 -- Don't warn if original condition is explicit False,
10073 -- since obviously the failure is expected in this case.
10075 if Is_Entity_Name (Expr)
10076 and then Entity (Expr) = Standard_False
10080 -- Issue warning. We do not want the deletion of the
10081 -- IF/AND-THEN to take this message with it. We achieve this
10082 -- by making sure that the expanded code points to the Sloc
10083 -- of the expression, not the original pragma.
10086 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10087 -- The source location of the expression is not usually
10088 -- the best choice here. For example, it gets located on
10089 -- the last AND keyword in a chain of boolean expressiond
10090 -- AND'ed together. It is best to put the message on the
10091 -- first character of the assertion, which is the effect
10092 -- of the First_Node call here.
10095 ("?A?assertion would fail at run time!",
10097 (First (Pragma_Argument_Associations (Orig))));
10101 -- Similar processing for Check pragma
10103 elsif Nkind (Orig) = N_Pragma
10104 and then Pragma_Name (Orig) = Name_Check
10106 -- Don't want to warn if original condition is explicit False
10109 Expr : constant Node_Id :=
10112 (Next (First (Pragma_Argument_Associations (Orig)))));
10114 if Is_Entity_Name (Expr)
10115 and then Entity (Expr) = Standard_False
10122 -- Again use Error_Msg_F rather than Error_Msg_N, see
10123 -- comment above for an explanation of why we do this.
10126 ("?A?check would fail at run time!",
10128 (Last (Pragma_Argument_Associations (Orig))));
10135 -- Continue with processing of short circuit
10137 Check_Unset_Reference (L);
10138 Check_Unset_Reference (R);
10140 Set_Etype (N, B_Typ);
10141 Eval_Short_Circuit (N);
10142 end Resolve_Short_Circuit;
10144 -------------------
10145 -- Resolve_Slice --
10146 -------------------
10148 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10149 Drange : constant Node_Id := Discrete_Range (N);
10150 Name : constant Node_Id := Prefix (N);
10151 Array_Type : Entity_Id := Empty;
10152 Dexpr : Node_Id := Empty;
10153 Index_Type : Entity_Id;
10156 if Is_Overloaded (Name) then
10158 -- Use the context type to select the prefix that yields the correct
10163 I1 : Interp_Index := 0;
10165 P : constant Node_Id := Prefix (N);
10166 Found : Boolean := False;
10169 Get_First_Interp (P, I, It);
10170 while Present (It.Typ) loop
10171 if (Is_Array_Type (It.Typ)
10172 and then Covers (Typ, It.Typ))
10173 or else (Is_Access_Type (It.Typ)
10174 and then Is_Array_Type (Designated_Type (It.Typ))
10175 and then Covers (Typ, Designated_Type (It.Typ)))
10178 It := Disambiguate (P, I1, I, Any_Type);
10180 if It = No_Interp then
10181 Error_Msg_N ("ambiguous prefix for slicing", N);
10182 Set_Etype (N, Typ);
10186 Array_Type := It.Typ;
10191 Array_Type := It.Typ;
10196 Get_Next_Interp (I, It);
10201 Array_Type := Etype (Name);
10204 Resolve (Name, Array_Type);
10206 if Is_Access_Type (Array_Type) then
10207 Apply_Access_Check (N);
10208 Array_Type := Designated_Type (Array_Type);
10210 -- If the prefix is an access to an unconstrained array, we must use
10211 -- the actual subtype of the object to perform the index checks. The
10212 -- object denoted by the prefix is implicit in the node, so we build
10213 -- an explicit representation for it in order to compute the actual
10216 if not Is_Constrained (Array_Type) then
10217 Remove_Side_Effects (Prefix (N));
10220 Obj : constant Node_Id :=
10221 Make_Explicit_Dereference (Sloc (N),
10222 Prefix => New_Copy_Tree (Prefix (N)));
10224 Set_Etype (Obj, Array_Type);
10225 Set_Parent (Obj, Parent (N));
10226 Array_Type := Get_Actual_Subtype (Obj);
10230 elsif Is_Entity_Name (Name)
10231 or else Nkind (Name) = N_Explicit_Dereference
10232 or else (Nkind (Name) = N_Function_Call
10233 and then not Is_Constrained (Etype (Name)))
10235 Array_Type := Get_Actual_Subtype (Name);
10237 -- If the name is a selected component that depends on discriminants,
10238 -- build an actual subtype for it. This can happen only when the name
10239 -- itself is overloaded; otherwise the actual subtype is created when
10240 -- the selected component is analyzed.
10242 elsif Nkind (Name) = N_Selected_Component
10243 and then Full_Analysis
10244 and then Depends_On_Discriminant (First_Index (Array_Type))
10247 Act_Decl : constant Node_Id :=
10248 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10250 Insert_Action (N, Act_Decl);
10251 Array_Type := Defining_Identifier (Act_Decl);
10254 -- Maybe this should just be "else", instead of checking for the
10255 -- specific case of slice??? This is needed for the case where the
10256 -- prefix is an Image attribute, which gets expanded to a slice, and so
10257 -- has a constrained subtype which we want to use for the slice range
10258 -- check applied below (the range check won't get done if the
10259 -- unconstrained subtype of the 'Image is used).
10261 elsif Nkind (Name) = N_Slice then
10262 Array_Type := Etype (Name);
10265 -- Obtain the type of the array index
10267 if Ekind (Array_Type) = E_String_Literal_Subtype then
10268 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10270 Index_Type := Etype (First_Index (Array_Type));
10273 -- If name was overloaded, set slice type correctly now
10275 Set_Etype (N, Array_Type);
10277 -- Handle the generation of a range check that compares the array index
10278 -- against the discrete_range. The check is not applied to internally
10279 -- built nodes associated with the expansion of dispatch tables. Check
10280 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10283 if Tagged_Type_Expansion
10284 and then RTU_Loaded (Ada_Tags)
10285 and then Nkind (Prefix (N)) = N_Selected_Component
10286 and then Present (Entity (Selector_Name (Prefix (N))))
10287 and then Entity (Selector_Name (Prefix (N))) =
10288 RTE_Record_Component (RE_Prims_Ptr)
10292 -- The discrete_range is specified by a subtype indication. Create a
10293 -- shallow copy and inherit the type, parent and source location from
10294 -- the discrete_range. This ensures that the range check is inserted
10295 -- relative to the slice and that the runtime exception points to the
10296 -- proper construct.
10298 elsif Is_Entity_Name (Drange) then
10299 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10301 Set_Etype (Dexpr, Etype (Drange));
10302 Set_Parent (Dexpr, Parent (Drange));
10303 Set_Sloc (Dexpr, Sloc (Drange));
10305 -- The discrete_range is a regular range. Resolve the bounds and remove
10306 -- their side effects.
10309 Resolve (Drange, Base_Type (Index_Type));
10311 if Nkind (Drange) = N_Range then
10312 Force_Evaluation (Low_Bound (Drange));
10313 Force_Evaluation (High_Bound (Drange));
10319 if Present (Dexpr) then
10320 Apply_Range_Check (Dexpr, Index_Type);
10323 Set_Slice_Subtype (N);
10325 -- Check bad use of type with predicates
10331 if Nkind (Drange) = N_Subtype_Indication
10332 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10334 Subt := Entity (Subtype_Mark (Drange));
10336 Subt := Etype (Drange);
10339 if Has_Predicates (Subt) then
10340 Bad_Predicated_Subtype_Use
10341 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10345 -- Otherwise here is where we check suspicious indexes
10347 if Nkind (Drange) = N_Range then
10348 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10349 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10352 Analyze_Dimension (N);
10356 ----------------------------
10357 -- Resolve_String_Literal --
10358 ----------------------------
10360 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10361 C_Typ : constant Entity_Id := Component_Type (Typ);
10362 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10363 Loc : constant Source_Ptr := Sloc (N);
10364 Str : constant String_Id := Strval (N);
10365 Strlen : constant Nat := String_Length (Str);
10366 Subtype_Id : Entity_Id;
10367 Need_Check : Boolean;
10370 -- For a string appearing in a concatenation, defer creation of the
10371 -- string_literal_subtype until the end of the resolution of the
10372 -- concatenation, because the literal may be constant-folded away. This
10373 -- is a useful optimization for long concatenation expressions.
10375 -- If the string is an aggregate built for a single character (which
10376 -- happens in a non-static context) or a is null string to which special
10377 -- checks may apply, we build the subtype. Wide strings must also get a
10378 -- string subtype if they come from a one character aggregate. Strings
10379 -- generated by attributes might be static, but it is often hard to
10380 -- determine whether the enclosing context is static, so we generate
10381 -- subtypes for them as well, thus losing some rarer optimizations ???
10382 -- Same for strings that come from a static conversion.
10385 (Strlen = 0 and then Typ /= Standard_String)
10386 or else Nkind (Parent (N)) /= N_Op_Concat
10387 or else (N /= Left_Opnd (Parent (N))
10388 and then N /= Right_Opnd (Parent (N)))
10389 or else ((Typ = Standard_Wide_String
10390 or else Typ = Standard_Wide_Wide_String)
10391 and then Nkind (Original_Node (N)) /= N_String_Literal);
10393 -- If the resolving type is itself a string literal subtype, we can just
10394 -- reuse it, since there is no point in creating another.
10396 if Ekind (Typ) = E_String_Literal_Subtype then
10399 elsif Nkind (Parent (N)) = N_Op_Concat
10400 and then not Need_Check
10401 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10402 N_Attribute_Reference,
10403 N_Qualified_Expression,
10408 -- Do not generate a string literal subtype for the default expression
10409 -- of a formal parameter in GNATprove mode. This is because the string
10410 -- subtype is associated with the freezing actions of the subprogram,
10411 -- however freezing is disabled in GNATprove mode and as a result the
10412 -- subtype is unavailable.
10414 elsif GNATprove_Mode
10415 and then Nkind (Parent (N)) = N_Parameter_Specification
10419 -- Otherwise we must create a string literal subtype. Note that the
10420 -- whole idea of string literal subtypes is simply to avoid the need
10421 -- for building a full fledged array subtype for each literal.
10424 Set_String_Literal_Subtype (N, Typ);
10425 Subtype_Id := Etype (N);
10428 if Nkind (Parent (N)) /= N_Op_Concat
10431 Set_Etype (N, Subtype_Id);
10432 Eval_String_Literal (N);
10435 if Is_Limited_Composite (Typ)
10436 or else Is_Private_Composite (Typ)
10438 Error_Msg_N ("string literal not available for private array", N);
10439 Set_Etype (N, Any_Type);
10443 -- The validity of a null string has been checked in the call to
10444 -- Eval_String_Literal.
10449 -- Always accept string literal with component type Any_Character, which
10450 -- occurs in error situations and in comparisons of literals, both of
10451 -- which should accept all literals.
10453 elsif R_Typ = Any_Character then
10456 -- If the type is bit-packed, then we always transform the string
10457 -- literal into a full fledged aggregate.
10459 elsif Is_Bit_Packed_Array (Typ) then
10462 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10465 -- For Standard.Wide_Wide_String, or any other type whose component
10466 -- type is Standard.Wide_Wide_Character, we know that all the
10467 -- characters in the string must be acceptable, since the parser
10468 -- accepted the characters as valid character literals.
10470 if R_Typ = Standard_Wide_Wide_Character then
10473 -- For the case of Standard.String, or any other type whose component
10474 -- type is Standard.Character, we must make sure that there are no
10475 -- wide characters in the string, i.e. that it is entirely composed
10476 -- of characters in range of type Character.
10478 -- If the string literal is the result of a static concatenation, the
10479 -- test has already been performed on the components, and need not be
10482 elsif R_Typ = Standard_Character
10483 and then Nkind (Original_Node (N)) /= N_Op_Concat
10485 for J in 1 .. Strlen loop
10486 if not In_Character_Range (Get_String_Char (Str, J)) then
10488 -- If we are out of range, post error. This is one of the
10489 -- very few places that we place the flag in the middle of
10490 -- a token, right under the offending wide character. Not
10491 -- quite clear if this is right wrt wide character encoding
10492 -- sequences, but it's only an error message.
10495 ("literal out of range of type Standard.Character",
10496 Source_Ptr (Int (Loc) + J));
10501 -- For the case of Standard.Wide_String, or any other type whose
10502 -- component type is Standard.Wide_Character, we must make sure that
10503 -- there are no wide characters in the string, i.e. that it is
10504 -- entirely composed of characters in range of type Wide_Character.
10506 -- If the string literal is the result of a static concatenation,
10507 -- the test has already been performed on the components, and need
10508 -- not be repeated.
10510 elsif R_Typ = Standard_Wide_Character
10511 and then Nkind (Original_Node (N)) /= N_Op_Concat
10513 for J in 1 .. Strlen loop
10514 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10516 -- If we are out of range, post error. This is one of the
10517 -- very few places that we place the flag in the middle of
10518 -- a token, right under the offending wide character.
10520 -- This is not quite right, because characters in general
10521 -- will take more than one character position ???
10524 ("literal out of range of type Standard.Wide_Character",
10525 Source_Ptr (Int (Loc) + J));
10530 -- If the root type is not a standard character, then we will convert
10531 -- the string into an aggregate and will let the aggregate code do
10532 -- the checking. Standard Wide_Wide_Character is also OK here.
10538 -- See if the component type of the array corresponding to the string
10539 -- has compile time known bounds. If yes we can directly check
10540 -- whether the evaluation of the string will raise constraint error.
10541 -- Otherwise we need to transform the string literal into the
10542 -- corresponding character aggregate and let the aggregate code do
10545 if Is_Standard_Character_Type (R_Typ) then
10547 -- Check for the case of full range, where we are definitely OK
10549 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10553 -- Here the range is not the complete base type range, so check
10556 Comp_Typ_Lo : constant Node_Id :=
10557 Type_Low_Bound (Component_Type (Typ));
10558 Comp_Typ_Hi : constant Node_Id :=
10559 Type_High_Bound (Component_Type (Typ));
10564 if Compile_Time_Known_Value (Comp_Typ_Lo)
10565 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10567 for J in 1 .. Strlen loop
10568 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10570 if Char_Val < Expr_Value (Comp_Typ_Lo)
10571 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10573 Apply_Compile_Time_Constraint_Error
10574 (N, "character out of range??",
10575 CE_Range_Check_Failed,
10576 Loc => Source_Ptr (Int (Loc) + J));
10586 -- If we got here we meed to transform the string literal into the
10587 -- equivalent qualified positional array aggregate. This is rather
10588 -- heavy artillery for this situation, but it is hard work to avoid.
10591 Lits : constant List_Id := New_List;
10592 P : Source_Ptr := Loc + 1;
10596 -- Build the character literals, we give them source locations that
10597 -- correspond to the string positions, which is a bit tricky given
10598 -- the possible presence of wide character escape sequences.
10600 for J in 1 .. Strlen loop
10601 C := Get_String_Char (Str, J);
10602 Set_Character_Literal_Name (C);
10605 Make_Character_Literal (P,
10606 Chars => Name_Find,
10607 Char_Literal_Value => UI_From_CC (C)));
10609 if In_Character_Range (C) then
10612 -- Should we have a call to Skip_Wide here ???
10621 Make_Qualified_Expression (Loc,
10622 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10624 Make_Aggregate (Loc, Expressions => Lits)));
10626 Analyze_And_Resolve (N, Typ);
10628 end Resolve_String_Literal;
10630 -----------------------------
10631 -- Resolve_Type_Conversion --
10632 -----------------------------
10634 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10635 Conv_OK : constant Boolean := Conversion_OK (N);
10636 Operand : constant Node_Id := Expression (N);
10637 Operand_Typ : constant Entity_Id := Etype (Operand);
10638 Target_Typ : constant Entity_Id := Etype (N);
10643 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10644 -- Set to False to suppress cases where we want to suppress the test
10645 -- for redundancy to avoid possible false positives on this warning.
10649 and then not Valid_Conversion (N, Target_Typ, Operand)
10654 -- If the Operand Etype is Universal_Fixed, then the conversion is
10655 -- never redundant. We need this check because by the time we have
10656 -- finished the rather complex transformation, the conversion looks
10657 -- redundant when it is not.
10659 if Operand_Typ = Universal_Fixed then
10660 Test_Redundant := False;
10662 -- If the operand is marked as Any_Fixed, then special processing is
10663 -- required. This is also a case where we suppress the test for a
10664 -- redundant conversion, since most certainly it is not redundant.
10666 elsif Operand_Typ = Any_Fixed then
10667 Test_Redundant := False;
10669 -- Mixed-mode operation involving a literal. Context must be a fixed
10670 -- type which is applied to the literal subsequently.
10672 if Is_Fixed_Point_Type (Typ) then
10673 Set_Etype (Operand, Universal_Real);
10675 elsif Is_Numeric_Type (Typ)
10676 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10677 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10679 Etype (Left_Opnd (Operand)) = Universal_Real)
10681 -- Return if expression is ambiguous
10683 if Unique_Fixed_Point_Type (N) = Any_Type then
10686 -- If nothing else, the available fixed type is Duration
10689 Set_Etype (Operand, Standard_Duration);
10692 -- Resolve the real operand with largest available precision
10694 if Etype (Right_Opnd (Operand)) = Universal_Real then
10695 Rop := New_Copy_Tree (Right_Opnd (Operand));
10697 Rop := New_Copy_Tree (Left_Opnd (Operand));
10700 Resolve (Rop, Universal_Real);
10702 -- If the operand is a literal (it could be a non-static and
10703 -- illegal exponentiation) check whether the use of Duration
10704 -- is potentially inaccurate.
10706 if Nkind (Rop) = N_Real_Literal
10707 and then Realval (Rop) /= Ureal_0
10708 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10711 ("??universal real operand can only "
10712 & "be interpreted as Duration!", Rop);
10714 ("\??precision will be lost in the conversion!", Rop);
10717 elsif Is_Numeric_Type (Typ)
10718 and then Nkind (Operand) in N_Op
10719 and then Unique_Fixed_Point_Type (N) /= Any_Type
10721 Set_Etype (Operand, Standard_Duration);
10724 Error_Msg_N ("invalid context for mixed mode operation", N);
10725 Set_Etype (Operand, Any_Type);
10732 -- In SPARK, a type conversion between array types should be restricted
10733 -- to types which have matching static bounds.
10735 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10736 -- operation if not needed.
10738 if Restriction_Check_Required (SPARK_05)
10739 and then Is_Array_Type (Target_Typ)
10740 and then Is_Array_Type (Operand_Typ)
10741 and then Operand_Typ /= Any_Composite -- or else Operand in error
10742 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10744 Check_SPARK_05_Restriction
10745 ("array types should have matching static bounds", N);
10748 -- In formal mode, the operand of an ancestor type conversion must be an
10749 -- object (not an expression).
10751 if Is_Tagged_Type (Target_Typ)
10752 and then not Is_Class_Wide_Type (Target_Typ)
10753 and then Is_Tagged_Type (Operand_Typ)
10754 and then not Is_Class_Wide_Type (Operand_Typ)
10755 and then Is_Ancestor (Target_Typ, Operand_Typ)
10756 and then not Is_SPARK_05_Object_Reference (Operand)
10758 Check_SPARK_05_Restriction ("object required", Operand);
10761 Analyze_Dimension (N);
10763 -- Note: we do the Eval_Type_Conversion call before applying the
10764 -- required checks for a subtype conversion. This is important, since
10765 -- both are prepared under certain circumstances to change the type
10766 -- conversion to a constraint error node, but in the case of
10767 -- Eval_Type_Conversion this may reflect an illegality in the static
10768 -- case, and we would miss the illegality (getting only a warning
10769 -- message), if we applied the type conversion checks first.
10771 Eval_Type_Conversion (N);
10773 -- Even when evaluation is not possible, we may be able to simplify the
10774 -- conversion or its expression. This needs to be done before applying
10775 -- checks, since otherwise the checks may use the original expression
10776 -- and defeat the simplifications. This is specifically the case for
10777 -- elimination of the floating-point Truncation attribute in
10778 -- float-to-int conversions.
10780 Simplify_Type_Conversion (N);
10782 -- If after evaluation we still have a type conversion, then we may need
10783 -- to apply checks required for a subtype conversion.
10785 -- Skip these type conversion checks if universal fixed operands
10786 -- operands involved, since range checks are handled separately for
10787 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10789 if Nkind (N) = N_Type_Conversion
10790 and then not Is_Generic_Type (Root_Type (Target_Typ))
10791 and then Target_Typ /= Universal_Fixed
10792 and then Operand_Typ /= Universal_Fixed
10794 Apply_Type_Conversion_Checks (N);
10797 -- Issue warning for conversion of simple object to its own type. We
10798 -- have to test the original nodes, since they may have been rewritten
10799 -- by various optimizations.
10801 Orig_N := Original_Node (N);
10803 -- Here we test for a redundant conversion if the warning mode is
10804 -- active (and was not locally reset), and we have a type conversion
10805 -- from source not appearing in a generic instance.
10808 and then Nkind (Orig_N) = N_Type_Conversion
10809 and then Comes_From_Source (Orig_N)
10810 and then not In_Instance
10812 Orig_N := Original_Node (Expression (Orig_N));
10813 Orig_T := Target_Typ;
10815 -- If the node is part of a larger expression, the Target_Type
10816 -- may not be the original type of the node if the context is a
10817 -- condition. Recover original type to see if conversion is needed.
10819 if Is_Boolean_Type (Orig_T)
10820 and then Nkind (Parent (N)) in N_Op
10822 Orig_T := Etype (Parent (N));
10825 -- If we have an entity name, then give the warning if the entity
10826 -- is the right type, or if it is a loop parameter covered by the
10827 -- original type (that's needed because loop parameters have an
10828 -- odd subtype coming from the bounds).
10830 if (Is_Entity_Name (Orig_N)
10832 (Etype (Entity (Orig_N)) = Orig_T
10834 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10835 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10837 -- If not an entity, then type of expression must match
10839 or else Etype (Orig_N) = Orig_T
10841 -- One more check, do not give warning if the analyzed conversion
10842 -- has an expression with non-static bounds, and the bounds of the
10843 -- target are static. This avoids junk warnings in cases where the
10844 -- conversion is necessary to establish staticness, for example in
10845 -- a case statement.
10847 if not Is_OK_Static_Subtype (Operand_Typ)
10848 and then Is_OK_Static_Subtype (Target_Typ)
10852 -- Finally, if this type conversion occurs in a context requiring
10853 -- a prefix, and the expression is a qualified expression then the
10854 -- type conversion is not redundant, since a qualified expression
10855 -- is not a prefix, whereas a type conversion is. For example, "X
10856 -- := T'(Funx(...)).Y;" is illegal because a selected component
10857 -- requires a prefix, but a type conversion makes it legal: "X :=
10858 -- T(T'(Funx(...))).Y;"
10860 -- In Ada 2012, a qualified expression is a name, so this idiom is
10861 -- no longer needed, but we still suppress the warning because it
10862 -- seems unfriendly for warnings to pop up when you switch to the
10863 -- newer language version.
10865 elsif Nkind (Orig_N) = N_Qualified_Expression
10866 and then Nkind_In (Parent (N), N_Attribute_Reference,
10867 N_Indexed_Component,
10868 N_Selected_Component,
10870 N_Explicit_Dereference)
10874 -- Never warn on conversion to Long_Long_Integer'Base since
10875 -- that is most likely an artifact of the extended overflow
10876 -- checking and comes from complex expanded code.
10878 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10881 -- Here we give the redundant conversion warning. If it is an
10882 -- entity, give the name of the entity in the message. If not,
10883 -- just mention the expression.
10885 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10888 if Is_Entity_Name (Orig_N) then
10889 Error_Msg_Node_2 := Orig_T;
10890 Error_Msg_NE -- CODEFIX
10891 ("??redundant conversion, & is of type &!",
10892 N, Entity (Orig_N));
10895 ("??redundant conversion, expression is of type&!",
10902 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10903 -- No need to perform any interface conversion if the type of the
10904 -- expression coincides with the target type.
10906 if Ada_Version >= Ada_2005
10907 and then Expander_Active
10908 and then Operand_Typ /= Target_Typ
10911 Opnd : Entity_Id := Operand_Typ;
10912 Target : Entity_Id := Target_Typ;
10915 -- If the type of the operand is a limited view, use nonlimited
10916 -- view when available. If it is a class-wide type, recover the
10917 -- class-wide type of the nonlimited view.
10919 if From_Limited_With (Opnd)
10920 and then Has_Non_Limited_View (Opnd)
10922 Opnd := Non_Limited_View (Opnd);
10923 Set_Etype (Expression (N), Opnd);
10926 if Is_Access_Type (Opnd) then
10927 Opnd := Designated_Type (Opnd);
10930 if Is_Access_Type (Target_Typ) then
10931 Target := Designated_Type (Target);
10934 if Opnd = Target then
10937 -- Conversion from interface type
10939 elsif Is_Interface (Opnd) then
10941 -- Ada 2005 (AI-217): Handle entities from limited views
10943 if From_Limited_With (Opnd) then
10944 Error_Msg_Qual_Level := 99;
10945 Error_Msg_NE -- CODEFIX
10946 ("missing WITH clause on package &", N,
10947 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10949 ("type conversions require visibility of the full view",
10952 elsif From_Limited_With (Target)
10954 (Is_Access_Type (Target_Typ)
10955 and then Present (Non_Limited_View (Etype (Target))))
10957 Error_Msg_Qual_Level := 99;
10958 Error_Msg_NE -- CODEFIX
10959 ("missing WITH clause on package &", N,
10960 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10962 ("type conversions require visibility of the full view",
10966 Expand_Interface_Conversion (N);
10969 -- Conversion to interface type
10971 elsif Is_Interface (Target) then
10975 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10976 Opnd := Etype (Opnd);
10979 if Is_Class_Wide_Type (Opnd)
10980 or else Interface_Present_In_Ancestor
10984 Expand_Interface_Conversion (N);
10986 Error_Msg_Name_1 := Chars (Etype (Target));
10987 Error_Msg_Name_2 := Chars (Opnd);
10989 ("wrong interface conversion (% is not a progenitor "
10996 -- Ada 2012: if target type has predicates, the result requires a
10997 -- predicate check. If the context is a call to another predicate
10998 -- check we must prevent infinite recursion.
11000 if Has_Predicates (Target_Typ) then
11001 if Nkind (Parent (N)) = N_Function_Call
11002 and then Present (Name (Parent (N)))
11003 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
11005 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
11010 Apply_Predicate_Check (N, Target_Typ);
11014 -- If at this stage we have a real to integer conversion, make sure
11015 -- that the Do_Range_Check flag is set, because such conversions in
11016 -- general need a range check. We only need this if expansion is off
11017 -- or we are in GNATProve mode.
11019 if Nkind (N) = N_Type_Conversion
11020 and then (GNATprove_Mode or not Expander_Active)
11021 and then Is_Integer_Type (Target_Typ)
11022 and then Is_Real_Type (Operand_Typ)
11024 Set_Do_Range_Check (Operand);
11026 end Resolve_Type_Conversion;
11028 ----------------------
11029 -- Resolve_Unary_Op --
11030 ----------------------
11032 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
11033 B_Typ : constant Entity_Id := Base_Type (Typ);
11034 R : constant Node_Id := Right_Opnd (N);
11040 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
11041 Error_Msg_Name_1 := Chars (Typ);
11042 Check_SPARK_05_Restriction
11043 ("unary operator not defined for modular type%", N);
11046 -- Deal with intrinsic unary operators
11048 if Comes_From_Source (N)
11049 and then Ekind (Entity (N)) = E_Function
11050 and then Is_Imported (Entity (N))
11051 and then Is_Intrinsic_Subprogram (Entity (N))
11053 Resolve_Intrinsic_Unary_Operator (N, Typ);
11057 -- Deal with universal cases
11059 if Etype (R) = Universal_Integer
11061 Etype (R) = Universal_Real
11063 Check_For_Visible_Operator (N, B_Typ);
11066 Set_Etype (N, B_Typ);
11067 Resolve (R, B_Typ);
11069 -- Generate warning for expressions like abs (x mod 2)
11071 if Warn_On_Redundant_Constructs
11072 and then Nkind (N) = N_Op_Abs
11074 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
11076 if OK and then Hi >= Lo and then Lo >= 0 then
11077 Error_Msg_N -- CODEFIX
11078 ("?r?abs applied to known non-negative value has no effect", N);
11082 -- Deal with reference generation
11084 Check_Unset_Reference (R);
11085 Generate_Operator_Reference (N, B_Typ);
11086 Analyze_Dimension (N);
11089 -- Set overflow checking bit. Much cleverer code needed here eventually
11090 -- and perhaps the Resolve routines should be separated for the various
11091 -- arithmetic operations, since they will need different processing ???
11093 if Nkind (N) in N_Op then
11094 if not Overflow_Checks_Suppressed (Etype (N)) then
11095 Enable_Overflow_Check (N);
11099 -- Generate warning for expressions like -5 mod 3 for integers. No need
11100 -- to worry in the floating-point case, since parens do not affect the
11101 -- result so there is no point in giving in a warning.
11104 Norig : constant Node_Id := Original_Node (N);
11113 if Warn_On_Questionable_Missing_Parens
11114 and then Comes_From_Source (Norig)
11115 and then Is_Integer_Type (Typ)
11116 and then Nkind (Norig) = N_Op_Minus
11118 Rorig := Original_Node (Right_Opnd (Norig));
11120 -- We are looking for cases where the right operand is not
11121 -- parenthesized, and is a binary operator, multiply, divide, or
11122 -- mod. These are the cases where the grouping can affect results.
11124 if Paren_Count (Rorig) = 0
11125 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11127 -- For mod, we always give the warning, since the value is
11128 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11129 -- -(5 mod 315)). But for the other cases, the only concern is
11130 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11131 -- overflows, but (-2) * 64 does not). So we try to give the
11132 -- message only when overflow is possible.
11134 if Nkind (Rorig) /= N_Op_Mod
11135 and then Compile_Time_Known_Value (R)
11137 Val := Expr_Value (R);
11139 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11140 HB := Expr_Value (Type_High_Bound (Typ));
11142 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11145 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11146 LB := Expr_Value (Type_Low_Bound (Typ));
11148 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11151 -- Note that the test below is deliberately excluding the
11152 -- largest negative number, since that is a potentially
11153 -- troublesome case (e.g. -2 * x, where the result is the
11154 -- largest negative integer has an overflow with 2 * x).
11156 if Val > LB and then Val <= HB then
11161 -- For the multiplication case, the only case we have to worry
11162 -- about is when (-a)*b is exactly the largest negative number
11163 -- so that -(a*b) can cause overflow. This can only happen if
11164 -- a is a power of 2, and more generally if any operand is a
11165 -- constant that is not a power of 2, then the parentheses
11166 -- cannot affect whether overflow occurs. We only bother to
11167 -- test the left most operand
11169 -- Loop looking at left operands for one that has known value
11172 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11173 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11174 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11176 -- Operand value of 0 or 1 skips warning
11181 -- Otherwise check power of 2, if power of 2, warn, if
11182 -- anything else, skip warning.
11185 while Lval /= 2 loop
11186 if Lval mod 2 = 1 then
11197 -- Keep looking at left operands
11199 Opnd := Left_Opnd (Opnd);
11200 end loop Opnd_Loop;
11202 -- For rem or "/" we can only have a problematic situation
11203 -- if the divisor has a value of minus one or one. Otherwise
11204 -- overflow is impossible (divisor > 1) or we have a case of
11205 -- division by zero in any case.
11207 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11208 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11209 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11214 -- If we fall through warning should be issued
11216 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11219 ("??unary minus expression should be parenthesized here!", N);
11223 end Resolve_Unary_Op;
11225 ----------------------------------
11226 -- Resolve_Unchecked_Expression --
11227 ----------------------------------
11229 procedure Resolve_Unchecked_Expression
11234 Resolve (Expression (N), Typ, Suppress => All_Checks);
11235 Set_Etype (N, Typ);
11236 end Resolve_Unchecked_Expression;
11238 ---------------------------------------
11239 -- Resolve_Unchecked_Type_Conversion --
11240 ---------------------------------------
11242 procedure Resolve_Unchecked_Type_Conversion
11246 pragma Warnings (Off, Typ);
11248 Operand : constant Node_Id := Expression (N);
11249 Opnd_Type : constant Entity_Id := Etype (Operand);
11252 -- Resolve operand using its own type
11254 Resolve (Operand, Opnd_Type);
11256 -- In an inlined context, the unchecked conversion may be applied
11257 -- to a literal, in which case its type is the type of the context.
11258 -- (In other contexts conversions cannot apply to literals).
11261 and then (Opnd_Type = Any_Character or else
11262 Opnd_Type = Any_Integer or else
11263 Opnd_Type = Any_Real)
11265 Set_Etype (Operand, Typ);
11268 Analyze_Dimension (N);
11269 Eval_Unchecked_Conversion (N);
11270 end Resolve_Unchecked_Type_Conversion;
11272 ------------------------------
11273 -- Rewrite_Operator_As_Call --
11274 ------------------------------
11276 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11277 Loc : constant Source_Ptr := Sloc (N);
11278 Actuals : constant List_Id := New_List;
11282 if Nkind (N) in N_Binary_Op then
11283 Append (Left_Opnd (N), Actuals);
11286 Append (Right_Opnd (N), Actuals);
11289 Make_Function_Call (Sloc => Loc,
11290 Name => New_Occurrence_Of (Nam, Loc),
11291 Parameter_Associations => Actuals);
11293 Preserve_Comes_From_Source (New_N, N);
11294 Preserve_Comes_From_Source (Name (New_N), N);
11295 Rewrite (N, New_N);
11296 Set_Etype (N, Etype (Nam));
11297 end Rewrite_Operator_As_Call;
11299 ------------------------------
11300 -- Rewrite_Renamed_Operator --
11301 ------------------------------
11303 procedure Rewrite_Renamed_Operator
11308 Nam : constant Name_Id := Chars (Op);
11309 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11313 -- Do not perform this transformation within a pre/postcondition,
11314 -- because the expression will be re-analyzed, and the transformation
11315 -- might affect the visibility of the operator, e.g. in an instance.
11317 if In_Assertion_Expr > 0 then
11321 -- Rewrite the operator node using the real operator, not its renaming.
11322 -- Exclude user-defined intrinsic operations of the same name, which are
11323 -- treated separately and rewritten as calls.
11325 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11326 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11327 Set_Chars (Op_Node, Nam);
11328 Set_Etype (Op_Node, Etype (N));
11329 Set_Entity (Op_Node, Op);
11330 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11332 -- Indicate that both the original entity and its renaming are
11333 -- referenced at this point.
11335 Generate_Reference (Entity (N), N);
11336 Generate_Reference (Op, N);
11339 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11342 Rewrite (N, Op_Node);
11344 -- If the context type is private, add the appropriate conversions so
11345 -- that the operator is applied to the full view. This is done in the
11346 -- routines that resolve intrinsic operators.
11348 if Is_Intrinsic_Subprogram (Op)
11349 and then Is_Private_Type (Typ)
11352 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11353 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11354 Resolve_Intrinsic_Operator (N, Typ);
11356 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11357 Resolve_Intrinsic_Unary_Operator (N, Typ);
11364 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11366 -- Operator renames a user-defined operator of the same name. Use the
11367 -- original operator in the node, which is the one Gigi knows about.
11369 Set_Entity (N, Op);
11370 Set_Is_Overloaded (N, False);
11372 end Rewrite_Renamed_Operator;
11374 -----------------------
11375 -- Set_Slice_Subtype --
11376 -----------------------
11378 -- Build an implicit subtype declaration to represent the type delivered by
11379 -- the slice. This is an abbreviated version of an array subtype. We define
11380 -- an index subtype for the slice, using either the subtype name or the
11381 -- discrete range of the slice. To be consistent with index usage elsewhere
11382 -- we create a list header to hold the single index. This list is not
11383 -- otherwise attached to the syntax tree.
11385 procedure Set_Slice_Subtype (N : Node_Id) is
11386 Loc : constant Source_Ptr := Sloc (N);
11387 Index_List : constant List_Id := New_List;
11389 Index_Subtype : Entity_Id;
11390 Index_Type : Entity_Id;
11391 Slice_Subtype : Entity_Id;
11392 Drange : constant Node_Id := Discrete_Range (N);
11395 Index_Type := Base_Type (Etype (Drange));
11397 if Is_Entity_Name (Drange) then
11398 Index_Subtype := Entity (Drange);
11401 -- We force the evaluation of a range. This is definitely needed in
11402 -- the renamed case, and seems safer to do unconditionally. Note in
11403 -- any case that since we will create and insert an Itype referring
11404 -- to this range, we must make sure any side effect removal actions
11405 -- are inserted before the Itype definition.
11407 if Nkind (Drange) = N_Range then
11408 Force_Evaluation (Low_Bound (Drange));
11409 Force_Evaluation (High_Bound (Drange));
11411 -- If the discrete range is given by a subtype indication, the
11412 -- type of the slice is the base of the subtype mark.
11414 elsif Nkind (Drange) = N_Subtype_Indication then
11416 R : constant Node_Id := Range_Expression (Constraint (Drange));
11418 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11419 Force_Evaluation (Low_Bound (R));
11420 Force_Evaluation (High_Bound (R));
11424 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11426 -- Take a new copy of Drange (where bounds have been rewritten to
11427 -- reference side-effect-free names). Using a separate tree ensures
11428 -- that further expansion (e.g. while rewriting a slice assignment
11429 -- into a FOR loop) does not attempt to remove side effects on the
11430 -- bounds again (which would cause the bounds in the index subtype
11431 -- definition to refer to temporaries before they are defined) (the
11432 -- reason is that some names are considered side effect free here
11433 -- for the subtype, but not in the context of a loop iteration
11436 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11437 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11438 Set_Etype (Index_Subtype, Index_Type);
11439 Set_Size_Info (Index_Subtype, Index_Type);
11440 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11443 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11445 Index := New_Occurrence_Of (Index_Subtype, Loc);
11446 Set_Etype (Index, Index_Subtype);
11447 Append (Index, Index_List);
11449 Set_First_Index (Slice_Subtype, Index);
11450 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11451 Set_Is_Constrained (Slice_Subtype, True);
11453 Check_Compile_Time_Size (Slice_Subtype);
11455 -- The Etype of the existing Slice node is reset to this slice subtype.
11456 -- Its bounds are obtained from its first index.
11458 Set_Etype (N, Slice_Subtype);
11460 -- For packed slice subtypes, freeze immediately (except in the case of
11461 -- being in a "spec expression" where we never freeze when we first see
11462 -- the expression).
11464 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11465 Freeze_Itype (Slice_Subtype, N);
11467 -- For all other cases insert an itype reference in the slice's actions
11468 -- so that the itype is frozen at the proper place in the tree (i.e. at
11469 -- the point where actions for the slice are analyzed). Note that this
11470 -- is different from freezing the itype immediately, which might be
11471 -- premature (e.g. if the slice is within a transient scope). This needs
11472 -- to be done only if expansion is enabled.
11474 elsif Expander_Active then
11475 Ensure_Defined (Typ => Slice_Subtype, N => N);
11477 end Set_Slice_Subtype;
11479 --------------------------------
11480 -- Set_String_Literal_Subtype --
11481 --------------------------------
11483 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11484 Loc : constant Source_Ptr := Sloc (N);
11485 Low_Bound : constant Node_Id :=
11486 Type_Low_Bound (Etype (First_Index (Typ)));
11487 Subtype_Id : Entity_Id;
11490 if Nkind (N) /= N_String_Literal then
11494 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11495 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11496 (String_Length (Strval (N))));
11497 Set_Etype (Subtype_Id, Base_Type (Typ));
11498 Set_Is_Constrained (Subtype_Id);
11499 Set_Etype (N, Subtype_Id);
11501 -- The low bound is set from the low bound of the corresponding index
11502 -- type. Note that we do not store the high bound in the string literal
11503 -- subtype, but it can be deduced if necessary from the length and the
11506 if Is_OK_Static_Expression (Low_Bound) then
11507 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11509 -- If the lower bound is not static we create a range for the string
11510 -- literal, using the index type and the known length of the literal.
11511 -- The index type is not necessarily Positive, so the upper bound is
11512 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11516 Index_List : constant List_Id := New_List;
11517 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11518 High_Bound : constant Node_Id :=
11519 Make_Attribute_Reference (Loc,
11520 Attribute_Name => Name_Val,
11522 New_Occurrence_Of (Index_Type, Loc),
11523 Expressions => New_List (
11526 Make_Attribute_Reference (Loc,
11527 Attribute_Name => Name_Pos,
11529 New_Occurrence_Of (Index_Type, Loc),
11531 New_List (New_Copy_Tree (Low_Bound))),
11533 Make_Integer_Literal (Loc,
11534 String_Length (Strval (N)) - 1))));
11536 Array_Subtype : Entity_Id;
11539 Index_Subtype : Entity_Id;
11542 if Is_Integer_Type (Index_Type) then
11543 Set_String_Literal_Low_Bound
11544 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11547 -- If the index type is an enumeration type, build bounds
11548 -- expression with attributes.
11550 Set_String_Literal_Low_Bound
11552 Make_Attribute_Reference (Loc,
11553 Attribute_Name => Name_First,
11555 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11556 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11559 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11561 -- Build bona fide subtype for the string, and wrap it in an
11562 -- unchecked conversion, because the backend expects the
11563 -- String_Literal_Subtype to have a static lower bound.
11566 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11567 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11568 Set_Scalar_Range (Index_Subtype, Drange);
11569 Set_Parent (Drange, N);
11570 Analyze_And_Resolve (Drange, Index_Type);
11572 -- In the context, the Index_Type may already have a constraint,
11573 -- so use common base type on string subtype. The base type may
11574 -- be used when generating attributes of the string, for example
11575 -- in the context of a slice assignment.
11577 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11578 Set_Size_Info (Index_Subtype, Index_Type);
11579 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11581 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11583 Index := New_Occurrence_Of (Index_Subtype, Loc);
11584 Set_Etype (Index, Index_Subtype);
11585 Append (Index, Index_List);
11587 Set_First_Index (Array_Subtype, Index);
11588 Set_Etype (Array_Subtype, Base_Type (Typ));
11589 Set_Is_Constrained (Array_Subtype, True);
11592 Make_Unchecked_Type_Conversion (Loc,
11593 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11594 Expression => Relocate_Node (N)));
11595 Set_Etype (N, Array_Subtype);
11598 end Set_String_Literal_Subtype;
11600 ------------------------------
11601 -- Simplify_Type_Conversion --
11602 ------------------------------
11604 procedure Simplify_Type_Conversion (N : Node_Id) is
11606 if Nkind (N) = N_Type_Conversion then
11608 Operand : constant Node_Id := Expression (N);
11609 Target_Typ : constant Entity_Id := Etype (N);
11610 Opnd_Typ : constant Entity_Id := Etype (Operand);
11613 -- Special processing if the conversion is the expression of a
11614 -- Rounding or Truncation attribute reference. In this case we
11617 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11623 -- with the Float_Truncate flag set to False or True respectively,
11624 -- which is more efficient.
11626 if Is_Floating_Point_Type (Opnd_Typ)
11628 (Is_Integer_Type (Target_Typ)
11629 or else (Is_Fixed_Point_Type (Target_Typ)
11630 and then Conversion_OK (N)))
11631 and then Nkind (Operand) = N_Attribute_Reference
11632 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11636 Truncate : constant Boolean :=
11637 Attribute_Name (Operand) = Name_Truncation;
11640 Relocate_Node (First (Expressions (Operand))));
11641 Set_Float_Truncate (N, Truncate);
11646 end Simplify_Type_Conversion;
11648 -----------------------------
11649 -- Unique_Fixed_Point_Type --
11650 -----------------------------
11652 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11653 T1 : Entity_Id := Empty;
11658 procedure Fixed_Point_Error;
11659 -- Give error messages for true ambiguity. Messages are posted on node
11660 -- N, and entities T1, T2 are the possible interpretations.
11662 -----------------------
11663 -- Fixed_Point_Error --
11664 -----------------------
11666 procedure Fixed_Point_Error is
11668 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11669 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11670 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11671 end Fixed_Point_Error;
11673 -- Start of processing for Unique_Fixed_Point_Type
11676 -- The operations on Duration are visible, so Duration is always a
11677 -- possible interpretation.
11679 T1 := Standard_Duration;
11681 -- Look for fixed-point types in enclosing scopes
11683 Scop := Current_Scope;
11684 while Scop /= Standard_Standard loop
11685 T2 := First_Entity (Scop);
11686 while Present (T2) loop
11687 if Is_Fixed_Point_Type (T2)
11688 and then Current_Entity (T2) = T2
11689 and then Scope (Base_Type (T2)) = Scop
11691 if Present (T1) then
11702 Scop := Scope (Scop);
11705 -- Look for visible fixed type declarations in the context
11707 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11708 while Present (Item) loop
11709 if Nkind (Item) = N_With_Clause then
11710 Scop := Entity (Name (Item));
11711 T2 := First_Entity (Scop);
11712 while Present (T2) loop
11713 if Is_Fixed_Point_Type (T2)
11714 and then Scope (Base_Type (T2)) = Scop
11715 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11717 if Present (T1) then
11732 if Nkind (N) = N_Real_Literal then
11734 ("??real literal interpreted as }!", N, T1);
11737 ("??universal_fixed expression interpreted as }!", N, T1);
11741 end Unique_Fixed_Point_Type;
11743 ----------------------
11744 -- Valid_Conversion --
11745 ----------------------
11747 function Valid_Conversion
11749 Target : Entity_Id;
11751 Report_Errs : Boolean := True) return Boolean
11753 Target_Type : constant Entity_Id := Base_Type (Target);
11754 Opnd_Type : Entity_Id := Etype (Operand);
11755 Inc_Ancestor : Entity_Id;
11757 function Conversion_Check
11759 Msg : String) return Boolean;
11760 -- Little routine to post Msg if Valid is False, returns Valid value
11762 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11763 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11765 procedure Conversion_Error_NE
11767 N : Node_Or_Entity_Id;
11768 E : Node_Or_Entity_Id);
11769 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11771 function Valid_Tagged_Conversion
11772 (Target_Type : Entity_Id;
11773 Opnd_Type : Entity_Id) return Boolean;
11774 -- Specifically test for validity of tagged conversions
11776 function Valid_Array_Conversion return Boolean;
11777 -- Check index and component conformance, and accessibility levels if
11778 -- the component types are anonymous access types (Ada 2005).
11780 ----------------------
11781 -- Conversion_Check --
11782 ----------------------
11784 function Conversion_Check
11786 Msg : String) return Boolean
11791 -- A generic unit has already been analyzed and we have verified
11792 -- that a particular conversion is OK in that context. Since the
11793 -- instance is reanalyzed without relying on the relationships
11794 -- established during the analysis of the generic, it is possible
11795 -- to end up with inconsistent views of private types. Do not emit
11796 -- the error message in such cases. The rest of the machinery in
11797 -- Valid_Conversion still ensures the proper compatibility of
11798 -- target and operand types.
11800 and then not In_Instance
11802 Conversion_Error_N (Msg, Operand);
11806 end Conversion_Check;
11808 ------------------------
11809 -- Conversion_Error_N --
11810 ------------------------
11812 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11814 if Report_Errs then
11815 Error_Msg_N (Msg, N);
11817 end Conversion_Error_N;
11819 -------------------------
11820 -- Conversion_Error_NE --
11821 -------------------------
11823 procedure Conversion_Error_NE
11825 N : Node_Or_Entity_Id;
11826 E : Node_Or_Entity_Id)
11829 if Report_Errs then
11830 Error_Msg_NE (Msg, N, E);
11832 end Conversion_Error_NE;
11834 ----------------------------
11835 -- Valid_Array_Conversion --
11836 ----------------------------
11838 function Valid_Array_Conversion return Boolean
11840 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11841 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11843 Opnd_Index : Node_Id;
11844 Opnd_Index_Type : Entity_Id;
11846 Target_Comp_Type : constant Entity_Id :=
11847 Component_Type (Target_Type);
11848 Target_Comp_Base : constant Entity_Id :=
11849 Base_Type (Target_Comp_Type);
11851 Target_Index : Node_Id;
11852 Target_Index_Type : Entity_Id;
11855 -- Error if wrong number of dimensions
11858 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11861 ("incompatible number of dimensions for conversion", Operand);
11864 -- Number of dimensions matches
11867 -- Loop through indexes of the two arrays
11869 Target_Index := First_Index (Target_Type);
11870 Opnd_Index := First_Index (Opnd_Type);
11871 while Present (Target_Index) and then Present (Opnd_Index) loop
11872 Target_Index_Type := Etype (Target_Index);
11873 Opnd_Index_Type := Etype (Opnd_Index);
11875 -- Error if index types are incompatible
11877 if not (Is_Integer_Type (Target_Index_Type)
11878 and then Is_Integer_Type (Opnd_Index_Type))
11879 and then (Root_Type (Target_Index_Type)
11880 /= Root_Type (Opnd_Index_Type))
11883 ("incompatible index types for array conversion",
11888 Next_Index (Target_Index);
11889 Next_Index (Opnd_Index);
11892 -- If component types have same base type, all set
11894 if Target_Comp_Base = Opnd_Comp_Base then
11897 -- Here if base types of components are not the same. The only
11898 -- time this is allowed is if we have anonymous access types.
11900 -- The conversion of arrays of anonymous access types can lead
11901 -- to dangling pointers. AI-392 formalizes the accessibility
11902 -- checks that must be applied to such conversions to prevent
11903 -- out-of-scope references.
11906 (Target_Comp_Base, E_Anonymous_Access_Type,
11907 E_Anonymous_Access_Subprogram_Type)
11908 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11910 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11912 if Type_Access_Level (Target_Type) <
11913 Deepest_Type_Access_Level (Opnd_Type)
11915 if In_Instance_Body then
11916 Error_Msg_Warn := SPARK_Mode /= On;
11918 ("source array type has deeper accessibility "
11919 & "level than target<<", Operand);
11920 Conversion_Error_N ("\Program_Error [<<", Operand);
11922 Make_Raise_Program_Error (Sloc (N),
11923 Reason => PE_Accessibility_Check_Failed));
11924 Set_Etype (N, Target_Type);
11927 -- Conversion not allowed because of accessibility levels
11931 ("source array type has deeper accessibility "
11932 & "level than target", Operand);
11940 -- All other cases where component base types do not match
11944 ("incompatible component types for array conversion",
11949 -- Check that component subtypes statically match. For numeric
11950 -- types this means that both must be either constrained or
11951 -- unconstrained. For enumeration types the bounds must match.
11952 -- All of this is checked in Subtypes_Statically_Match.
11954 if not Subtypes_Statically_Match
11955 (Target_Comp_Type, Opnd_Comp_Type)
11958 ("component subtypes must statically match", Operand);
11964 end Valid_Array_Conversion;
11966 -----------------------------
11967 -- Valid_Tagged_Conversion --
11968 -----------------------------
11970 function Valid_Tagged_Conversion
11971 (Target_Type : Entity_Id;
11972 Opnd_Type : Entity_Id) return Boolean
11975 -- Upward conversions are allowed (RM 4.6(22))
11977 if Covers (Target_Type, Opnd_Type)
11978 or else Is_Ancestor (Target_Type, Opnd_Type)
11982 -- Downward conversion are allowed if the operand is class-wide
11985 elsif Is_Class_Wide_Type (Opnd_Type)
11986 and then Covers (Opnd_Type, Target_Type)
11990 elsif Covers (Opnd_Type, Target_Type)
11991 or else Is_Ancestor (Opnd_Type, Target_Type)
11994 Conversion_Check (False,
11995 "downward conversion of tagged objects not allowed");
11997 -- Ada 2005 (AI-251): The conversion to/from interface types is
12000 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
12003 -- If the operand is a class-wide type obtained through a limited_
12004 -- with clause, and the context includes the nonlimited view, use
12005 -- it to determine whether the conversion is legal.
12007 elsif Is_Class_Wide_Type (Opnd_Type)
12008 and then From_Limited_With (Opnd_Type)
12009 and then Present (Non_Limited_View (Etype (Opnd_Type)))
12010 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
12014 elsif Is_Access_Type (Opnd_Type)
12015 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
12020 Conversion_Error_NE
12021 ("invalid tagged conversion, not compatible with}",
12022 N, First_Subtype (Opnd_Type));
12025 end Valid_Tagged_Conversion;
12027 -- Start of processing for Valid_Conversion
12030 Check_Parameterless_Call (Operand);
12032 if Is_Overloaded (Operand) then
12042 -- Remove procedure calls, which syntactically cannot appear in
12043 -- this context, but which cannot be removed by type checking,
12044 -- because the context does not impose a type.
12046 -- The node may be labelled overloaded, but still contain only one
12047 -- interpretation because others were discarded earlier. If this
12048 -- is the case, retain the single interpretation if legal.
12050 Get_First_Interp (Operand, I, It);
12051 Opnd_Type := It.Typ;
12052 Get_Next_Interp (I, It);
12054 if Present (It.Typ)
12055 and then Opnd_Type /= Standard_Void_Type
12057 -- More than one candidate interpretation is available
12059 Get_First_Interp (Operand, I, It);
12060 while Present (It.Typ) loop
12061 if It.Typ = Standard_Void_Type then
12065 -- When compiling for a system where Address is of a visible
12066 -- integer type, spurious ambiguities can be produced when
12067 -- arithmetic operations have a literal operand and return
12068 -- System.Address or a descendant of it. These ambiguities
12069 -- are usually resolved by the context, but for conversions
12070 -- there is no context type and the removal of the spurious
12071 -- operations must be done explicitly here.
12073 if not Address_Is_Private
12074 and then Is_Descendent_Of_Address (It.Typ)
12079 Get_Next_Interp (I, It);
12083 Get_First_Interp (Operand, I, It);
12087 if No (It.Typ) then
12088 Conversion_Error_N ("illegal operand in conversion", Operand);
12092 Get_Next_Interp (I, It);
12094 if Present (It.Typ) then
12097 It1 := Disambiguate (Operand, I1, I, Any_Type);
12099 if It1 = No_Interp then
12101 ("ambiguous operand in conversion", Operand);
12103 -- If the interpretation involves a standard operator, use
12104 -- the location of the type, which may be user-defined.
12106 if Sloc (It.Nam) = Standard_Location then
12107 Error_Msg_Sloc := Sloc (It.Typ);
12109 Error_Msg_Sloc := Sloc (It.Nam);
12112 Conversion_Error_N -- CODEFIX
12113 ("\\possible interpretation#!", Operand);
12115 if Sloc (N1) = Standard_Location then
12116 Error_Msg_Sloc := Sloc (T1);
12118 Error_Msg_Sloc := Sloc (N1);
12121 Conversion_Error_N -- CODEFIX
12122 ("\\possible interpretation#!", Operand);
12128 Set_Etype (Operand, It1.Typ);
12129 Opnd_Type := It1.Typ;
12133 -- Deal with conversion of integer type to address if the pragma
12134 -- Allow_Integer_Address is in effect. We convert the conversion to
12135 -- an unchecked conversion in this case and we are all done.
12137 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12138 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12139 Analyze_And_Resolve (N, Target_Type);
12143 -- If we are within a child unit, check whether the type of the
12144 -- expression has an ancestor in a parent unit, in which case it
12145 -- belongs to its derivation class even if the ancestor is private.
12146 -- See RM 7.3.1 (5.2/3).
12148 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12152 if Is_Numeric_Type (Target_Type) then
12154 -- A universal fixed expression can be converted to any numeric type
12156 if Opnd_Type = Universal_Fixed then
12159 -- Also no need to check when in an instance or inlined body, because
12160 -- the legality has been established when the template was analyzed.
12161 -- Furthermore, numeric conversions may occur where only a private
12162 -- view of the operand type is visible at the instantiation point.
12163 -- This results in a spurious error if we check that the operand type
12164 -- is a numeric type.
12166 -- Note: in a previous version of this unit, the following tests were
12167 -- applied only for generated code (Comes_From_Source set to False),
12168 -- but in fact the test is required for source code as well, since
12169 -- this situation can arise in source code.
12171 elsif In_Instance or else In_Inlined_Body then
12174 -- Otherwise we need the conversion check
12177 return Conversion_Check
12178 (Is_Numeric_Type (Opnd_Type)
12180 (Present (Inc_Ancestor)
12181 and then Is_Numeric_Type (Inc_Ancestor)),
12182 "illegal operand for numeric conversion");
12187 elsif Is_Array_Type (Target_Type) then
12188 if not Is_Array_Type (Opnd_Type)
12189 or else Opnd_Type = Any_Composite
12190 or else Opnd_Type = Any_String
12193 ("illegal operand for array conversion", Operand);
12197 return Valid_Array_Conversion;
12200 -- Ada 2005 (AI-251): Internally generated conversions of access to
12201 -- interface types added to force the displacement of the pointer to
12202 -- reference the corresponding dispatch table.
12204 elsif not Comes_From_Source (N)
12205 and then Is_Access_Type (Target_Type)
12206 and then Is_Interface (Designated_Type (Target_Type))
12210 -- Ada 2005 (AI-251): Anonymous access types where target references an
12213 elsif Is_Access_Type (Opnd_Type)
12214 and then Ekind_In (Target_Type, E_General_Access_Type,
12215 E_Anonymous_Access_Type)
12216 and then Is_Interface (Directly_Designated_Type (Target_Type))
12218 -- Check the static accessibility rule of 4.6(17). Note that the
12219 -- check is not enforced when within an instance body, since the
12220 -- RM requires such cases to be caught at run time.
12222 -- If the operand is a rewriting of an allocator no check is needed
12223 -- because there are no accessibility issues.
12225 if Nkind (Original_Node (N)) = N_Allocator then
12228 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12229 if Type_Access_Level (Opnd_Type) >
12230 Deepest_Type_Access_Level (Target_Type)
12232 -- In an instance, this is a run-time check, but one we know
12233 -- will fail, so generate an appropriate warning. The raise
12234 -- will be generated by Expand_N_Type_Conversion.
12236 if In_Instance_Body then
12237 Error_Msg_Warn := SPARK_Mode /= On;
12239 ("cannot convert local pointer to non-local access type<<",
12241 Conversion_Error_N ("\Program_Error [<<", Operand);
12245 ("cannot convert local pointer to non-local access type",
12250 -- Special accessibility checks are needed in the case of access
12251 -- discriminants declared for a limited type.
12253 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12254 and then not Is_Local_Anonymous_Access (Opnd_Type)
12256 -- When the operand is a selected access discriminant the check
12257 -- needs to be made against the level of the object denoted by
12258 -- the prefix of the selected name (Object_Access_Level handles
12259 -- checking the prefix of the operand for this case).
12261 if Nkind (Operand) = N_Selected_Component
12262 and then Object_Access_Level (Operand) >
12263 Deepest_Type_Access_Level (Target_Type)
12265 -- In an instance, this is a run-time check, but one we know
12266 -- will fail, so generate an appropriate warning. The raise
12267 -- will be generated by Expand_N_Type_Conversion.
12269 if In_Instance_Body then
12270 Error_Msg_Warn := SPARK_Mode /= On;
12272 ("cannot convert access discriminant to non-local "
12273 & "access type<<", Operand);
12274 Conversion_Error_N ("\Program_Error [<<", Operand);
12276 -- Real error if not in instance body
12280 ("cannot convert access discriminant to non-local "
12281 & "access type", Operand);
12286 -- The case of a reference to an access discriminant from
12287 -- within a limited type declaration (which will appear as
12288 -- a discriminal) is always illegal because the level of the
12289 -- discriminant is considered to be deeper than any (nameable)
12292 if Is_Entity_Name (Operand)
12293 and then not Is_Local_Anonymous_Access (Opnd_Type)
12295 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12296 and then Present (Discriminal_Link (Entity (Operand)))
12299 ("discriminant has deeper accessibility level than target",
12308 -- General and anonymous access types
12310 elsif Ekind_In (Target_Type, E_General_Access_Type,
12311 E_Anonymous_Access_Type)
12314 (Is_Access_Type (Opnd_Type)
12316 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12317 E_Access_Protected_Subprogram_Type),
12318 "must be an access-to-object type")
12320 if Is_Access_Constant (Opnd_Type)
12321 and then not Is_Access_Constant (Target_Type)
12324 ("access-to-constant operand type not allowed", Operand);
12328 -- Check the static accessibility rule of 4.6(17). Note that the
12329 -- check is not enforced when within an instance body, since the RM
12330 -- requires such cases to be caught at run time.
12332 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12333 or else Is_Local_Anonymous_Access (Target_Type)
12334 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12335 N_Object_Declaration
12337 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12338 -- conversions from an anonymous access type to a named general
12339 -- access type. Such conversions are not allowed in the case of
12340 -- access parameters and stand-alone objects of an anonymous
12341 -- access type. The implicit conversion case is recognized by
12342 -- testing that Comes_From_Source is False and that it's been
12343 -- rewritten. The Comes_From_Source test isn't sufficient because
12344 -- nodes in inlined calls to predefined library routines can have
12345 -- Comes_From_Source set to False. (Is there a better way to test
12346 -- for implicit conversions???)
12348 if Ada_Version >= Ada_2012
12349 and then not Comes_From_Source (N)
12350 and then N /= Original_Node (N)
12351 and then Ekind (Target_Type) = E_General_Access_Type
12352 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12354 if Is_Itype (Opnd_Type) then
12356 -- Implicit conversions aren't allowed for objects of an
12357 -- anonymous access type, since such objects have nonstatic
12358 -- levels in Ada 2012.
12360 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12361 N_Object_Declaration
12364 ("implicit conversion of stand-alone anonymous "
12365 & "access object not allowed", Operand);
12368 -- Implicit conversions aren't allowed for anonymous access
12369 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12370 -- is done to exclude anonymous access results.
12372 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12373 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12374 N_Function_Specification,
12375 N_Procedure_Specification)
12378 ("implicit conversion of anonymous access formal "
12379 & "not allowed", Operand);
12382 -- This is a case where there's an enclosing object whose
12383 -- to which the "statically deeper than" relationship does
12384 -- not apply (such as an access discriminant selected from
12385 -- a dereference of an access parameter).
12387 elsif Object_Access_Level (Operand)
12388 = Scope_Depth (Standard_Standard)
12391 ("implicit conversion of anonymous access value "
12392 & "not allowed", Operand);
12395 -- In other cases, the level of the operand's type must be
12396 -- statically less deep than that of the target type, else
12397 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12399 elsif Type_Access_Level (Opnd_Type) >
12400 Deepest_Type_Access_Level (Target_Type)
12403 ("implicit conversion of anonymous access value "
12404 & "violates accessibility", Operand);
12409 elsif Type_Access_Level (Opnd_Type) >
12410 Deepest_Type_Access_Level (Target_Type)
12412 -- In an instance, this is a run-time check, but one we know
12413 -- will fail, so generate an appropriate warning. The raise
12414 -- will be generated by Expand_N_Type_Conversion.
12416 if In_Instance_Body then
12417 Error_Msg_Warn := SPARK_Mode /= On;
12419 ("cannot convert local pointer to non-local access type<<",
12421 Conversion_Error_N ("\Program_Error [<<", Operand);
12423 -- If not in an instance body, this is a real error
12426 -- Avoid generation of spurious error message
12428 if not Error_Posted (N) then
12430 ("cannot convert local pointer to non-local access type",
12437 -- Special accessibility checks are needed in the case of access
12438 -- discriminants declared for a limited type.
12440 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12441 and then not Is_Local_Anonymous_Access (Opnd_Type)
12443 -- When the operand is a selected access discriminant the check
12444 -- needs to be made against the level of the object denoted by
12445 -- the prefix of the selected name (Object_Access_Level handles
12446 -- checking the prefix of the operand for this case).
12448 if Nkind (Operand) = N_Selected_Component
12449 and then Object_Access_Level (Operand) >
12450 Deepest_Type_Access_Level (Target_Type)
12452 -- In an instance, this is a run-time check, but one we know
12453 -- will fail, so generate an appropriate warning. The raise
12454 -- will be generated by Expand_N_Type_Conversion.
12456 if In_Instance_Body then
12457 Error_Msg_Warn := SPARK_Mode /= On;
12459 ("cannot convert access discriminant to non-local "
12460 & "access type<<", Operand);
12461 Conversion_Error_N ("\Program_Error [<<", Operand);
12463 -- If not in an instance body, this is a real error
12467 ("cannot convert access discriminant to non-local "
12468 & "access type", Operand);
12473 -- The case of a reference to an access discriminant from
12474 -- within a limited type declaration (which will appear as
12475 -- a discriminal) is always illegal because the level of the
12476 -- discriminant is considered to be deeper than any (nameable)
12479 if Is_Entity_Name (Operand)
12481 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12482 and then Present (Discriminal_Link (Entity (Operand)))
12485 ("discriminant has deeper accessibility level than target",
12492 -- In the presence of limited_with clauses we have to use nonlimited
12493 -- views, if available.
12495 Check_Limited : declare
12496 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12497 -- Helper function to handle limited views
12499 --------------------------
12500 -- Full_Designated_Type --
12501 --------------------------
12503 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12504 Desig : constant Entity_Id := Designated_Type (T);
12507 -- Handle the limited view of a type
12509 if From_Limited_With (Desig)
12510 and then Has_Non_Limited_View (Desig)
12512 return Available_View (Desig);
12516 end Full_Designated_Type;
12518 -- Local Declarations
12520 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12521 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12523 Same_Base : constant Boolean :=
12524 Base_Type (Target) = Base_Type (Opnd);
12526 -- Start of processing for Check_Limited
12529 if Is_Tagged_Type (Target) then
12530 return Valid_Tagged_Conversion (Target, Opnd);
12533 if not Same_Base then
12534 Conversion_Error_NE
12535 ("target designated type not compatible with }",
12536 N, Base_Type (Opnd));
12539 -- Ada 2005 AI-384: legality rule is symmetric in both
12540 -- designated types. The conversion is legal (with possible
12541 -- constraint check) if either designated type is
12544 elsif Subtypes_Statically_Match (Target, Opnd)
12546 (Has_Discriminants (Target)
12548 (not Is_Constrained (Opnd)
12549 or else not Is_Constrained (Target)))
12551 -- Special case, if Value_Size has been used to make the
12552 -- sizes different, the conversion is not allowed even
12553 -- though the subtypes statically match.
12555 if Known_Static_RM_Size (Target)
12556 and then Known_Static_RM_Size (Opnd)
12557 and then RM_Size (Target) /= RM_Size (Opnd)
12559 Conversion_Error_NE
12560 ("target designated subtype not compatible with }",
12562 Conversion_Error_NE
12563 ("\because sizes of the two designated subtypes differ",
12567 -- Normal case where conversion is allowed
12575 ("target designated subtype not compatible with }",
12582 -- Access to subprogram types. If the operand is an access parameter,
12583 -- the type has a deeper accessibility that any master, and cannot be
12584 -- assigned. We must make an exception if the conversion is part of an
12585 -- assignment and the target is the return object of an extended return
12586 -- statement, because in that case the accessibility check takes place
12587 -- after the return.
12589 elsif Is_Access_Subprogram_Type (Target_Type)
12591 -- Note: this test of Opnd_Type is there to prevent entering this
12592 -- branch in the case of a remote access to subprogram type, which
12593 -- is internally represented as an E_Record_Type.
12595 and then Is_Access_Type (Opnd_Type)
12597 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12598 and then Is_Entity_Name (Operand)
12599 and then Ekind (Entity (Operand)) = E_In_Parameter
12601 (Nkind (Parent (N)) /= N_Assignment_Statement
12602 or else not Is_Entity_Name (Name (Parent (N)))
12603 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12606 ("illegal attempt to store anonymous access to subprogram",
12609 ("\value has deeper accessibility than any master "
12610 & "(RM 3.10.2 (13))",
12614 ("\use named access type for& instead of access parameter",
12615 Operand, Entity (Operand));
12618 -- Check that the designated types are subtype conformant
12620 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12621 Old_Id => Designated_Type (Opnd_Type),
12624 -- Check the static accessibility rule of 4.6(20)
12626 if Type_Access_Level (Opnd_Type) >
12627 Deepest_Type_Access_Level (Target_Type)
12630 ("operand type has deeper accessibility level than target",
12633 -- Check that if the operand type is declared in a generic body,
12634 -- then the target type must be declared within that same body
12635 -- (enforces last sentence of 4.6(20)).
12637 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12639 O_Gen : constant Node_Id :=
12640 Enclosing_Generic_Body (Opnd_Type);
12645 T_Gen := Enclosing_Generic_Body (Target_Type);
12646 while Present (T_Gen) and then T_Gen /= O_Gen loop
12647 T_Gen := Enclosing_Generic_Body (T_Gen);
12650 if T_Gen /= O_Gen then
12652 ("target type must be declared in same generic body "
12653 & "as operand type", N);
12660 -- Remote access to subprogram types
12662 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12663 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12665 -- It is valid to convert from one RAS type to another provided
12666 -- that their specification statically match.
12668 -- Note: at this point, remote access to subprogram types have been
12669 -- expanded to their E_Record_Type representation, and we need to
12670 -- go back to the original access type definition using the
12671 -- Corresponding_Remote_Type attribute in order to check that the
12672 -- designated profiles match.
12674 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12675 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12677 Check_Subtype_Conformant
12679 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12681 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12686 -- If it was legal in the generic, it's legal in the instance
12688 elsif In_Instance_Body then
12691 -- If both are tagged types, check legality of view conversions
12693 elsif Is_Tagged_Type (Target_Type)
12695 Is_Tagged_Type (Opnd_Type)
12697 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12699 -- Types derived from the same root type are convertible
12701 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12704 -- In an instance or an inlined body, there may be inconsistent views of
12705 -- the same type, or of types derived from a common root.
12707 elsif (In_Instance or In_Inlined_Body)
12709 Root_Type (Underlying_Type (Target_Type)) =
12710 Root_Type (Underlying_Type (Opnd_Type))
12714 -- Special check for common access type error case
12716 elsif Ekind (Target_Type) = E_Access_Type
12717 and then Is_Access_Type (Opnd_Type)
12719 Conversion_Error_N ("target type must be general access type!", N);
12720 Conversion_Error_NE -- CODEFIX
12721 ("add ALL to }!", N, Target_Type);
12724 -- Here we have a real conversion error
12727 Conversion_Error_NE
12728 ("invalid conversion, not compatible with }", N, Opnd_Type);
12731 end Valid_Conversion;