1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Disp; use Exp_Disp;
34 with Exp_Ch6; use Exp_Ch6;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Tss; use Exp_Tss;
37 with Exp_Util; use Exp_Util;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Ghost; use Ghost;
41 with Inline; use Inline;
42 with Itypes; use Itypes;
44 with Lib.Xref; use Lib.Xref;
45 with Namet; use Namet;
46 with Nmake; use Nmake;
47 with Nlists; use Nlists;
49 with Output; use Output;
50 with Par_SCO; use Par_SCO;
51 with Restrict; use Restrict;
52 with Rident; use Rident;
53 with Rtsfind; use Rtsfind;
55 with Sem_Aux; use Sem_Aux;
56 with Sem_Aggr; use Sem_Aggr;
57 with Sem_Attr; use Sem_Attr;
58 with Sem_Cat; use Sem_Cat;
59 with Sem_Ch4; use Sem_Ch4;
60 with Sem_Ch3; use Sem_Ch3;
61 with Sem_Ch6; use Sem_Ch6;
62 with Sem_Ch8; use Sem_Ch8;
63 with Sem_Ch13; use Sem_Ch13;
64 with Sem_Dim; use Sem_Dim;
65 with Sem_Disp; use Sem_Disp;
66 with Sem_Dist; use Sem_Dist;
67 with Sem_Elim; use Sem_Elim;
68 with Sem_Elab; use Sem_Elab;
69 with Sem_Eval; use Sem_Eval;
70 with Sem_Intr; use Sem_Intr;
71 with Sem_Util; use Sem_Util;
72 with Targparm; use Targparm;
73 with Sem_Type; use Sem_Type;
74 with Sem_Warn; use Sem_Warn;
75 with Sinfo; use Sinfo;
76 with Sinfo.CN; use Sinfo.CN;
77 with Snames; use Snames;
78 with Stand; use Stand;
79 with Stringt; use Stringt;
80 with Style; use Style;
81 with Tbuild; use Tbuild;
82 with Uintp; use Uintp;
83 with Urealp; use Urealp;
85 package body Sem_Res is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use (N : Node_Id);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
116 -- Given a call node, N, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
122 -- If the type of the object being initialized uses the secondary stack
123 -- directly or indirectly, create a transient scope for the call to the
124 -- init proc. This is because we do not create transient scopes for the
125 -- initialization of individual components within the init proc itself.
126 -- Could be optimized away perhaps?
128 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
129 -- N is the node for a logical operator. If the operator is predefined, and
130 -- the root type of the operands is Standard.Boolean, then a check is made
131 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
132 -- the style check for Style_Check_Boolean_And_Or.
134 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
135 -- N is either an indexed component or a selected component. This function
136 -- returns true if the prefix refers to an object that has an address
137 -- clause (the case in which we may want to issue a warning).
139 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
195 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
196 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
209 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
211 function Operator_Kind
213 Is_Binary : Boolean) return Node_Kind;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
236 -- Ditto, for arithmetic unary operators
238 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
242 procedure Make_Call_Into_Operator
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so that
248 -- operands are resolved properly. Recall that predefined operators do not
249 -- have a full signature and special resolution rules apply.
251 procedure Rewrite_Renamed_Operator
255 -- An operator can rename another, e.g. in an instantiation. In that
256 -- case, the proper operator node must be constructed and resolved.
258 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
259 -- The String_Literal_Subtype is built for all strings that are not
260 -- operands of a static concatenation operation. If the argument is not
261 -- a N_String_Literal node, then the call has no effect.
263 procedure Set_Slice_Subtype (N : Node_Id);
264 -- Build subtype of array type, with the range specified by the slice
266 procedure Simplify_Type_Conversion (N : Node_Id);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Rounding or Truncation attribute.
271 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
277 -------------------------
278 -- Ambiguous_Character --
279 -------------------------
281 procedure Ambiguous_Character (C : Node_Id) is
285 if Nkind (C) = N_Character_Literal then
286 Error_Msg_N ("ambiguous character literal", C);
288 -- First the ones in Standard
290 Error_Msg_N ("\\possible interpretation: Character!", C);
291 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
293 -- Include Wide_Wide_Character in Ada 2005 mode
295 if Ada_Version >= Ada_2005 then
296 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
299 -- Now any other types that match
301 E := Current_Entity (C);
302 while Present (E) loop
303 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
307 end Ambiguous_Character;
309 -------------------------
310 -- Analyze_And_Resolve --
311 -------------------------
313 procedure Analyze_And_Resolve (N : Node_Id) is
317 end Analyze_And_Resolve;
319 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
323 end Analyze_And_Resolve;
325 -- Versions with check(s) suppressed
327 procedure Analyze_And_Resolve
332 Scop : constant Entity_Id := Current_Scope;
335 if Suppress = All_Checks then
337 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
339 Scope_Suppress.Suppress := (others => True);
340 Analyze_And_Resolve (N, Typ);
341 Scope_Suppress.Suppress := Sva;
346 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
348 Scope_Suppress.Suppress (Suppress) := True;
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress.Suppress (Suppress) := Svg;
354 if Current_Scope /= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
366 end Analyze_And_Resolve;
368 procedure Analyze_And_Resolve
372 Scop : constant Entity_Id := Current_Scope;
375 if Suppress = All_Checks then
377 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
379 Scope_Suppress.Suppress := (others => True);
380 Analyze_And_Resolve (N);
381 Scope_Suppress.Suppress := Sva;
386 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
388 Scope_Suppress.Suppress (Suppress) := True;
389 Analyze_And_Resolve (N);
390 Scope_Suppress.Suppress (Suppress) := Svg;
394 if Current_Scope /= Scop and then Scope_Is_Transient then
395 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
398 end Analyze_And_Resolve;
400 ----------------------------
401 -- Check_Discriminant_Use --
402 ----------------------------
404 procedure Check_Discriminant_Use (N : Node_Id) is
405 PN : constant Node_Id := Parent (N);
406 Disc : constant Entity_Id := Entity (N);
411 -- Any use in a spec-expression is legal
413 if In_Spec_Expression then
416 elsif Nkind (PN) = N_Range then
418 -- Discriminant cannot be used to constrain a scalar type
422 if Nkind (P) = N_Range_Constraint
423 and then Nkind (Parent (P)) = N_Subtype_Indication
424 and then Nkind (Parent (Parent (P))) = N_Component_Definition
426 Error_Msg_N ("discriminant cannot constrain scalar type", N);
428 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
430 -- The following check catches the unusual case where a
431 -- discriminant appears within an index constraint that is part
432 -- of a larger expression within a constraint on a component,
433 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
434 -- check case of record components, and note that a similar check
435 -- should also apply in the case of discriminant constraints
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
446 if Ekind (Current_Scope) = E_Record_Type
447 and then Scope (Disc) = Current_Scope
449 (Nkind (Parent (P)) = N_Subtype_Indication
451 Nkind_In (Parent (Parent (P)), N_Component_Definition,
452 N_Subtype_Declaration)
453 and then Paren_Count (N) = 0)
456 ("discriminant must appear alone in component constraint", N);
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large : declare
477 function Large_Storage_Type (T : Entity_Id) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type (T : Entity_Id) return Boolean is
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value (Type_Low_Bound (T))
493 and then Compile_Time_Known_Value (Type_High_Bound (T))
495 Minimum_Size (T, Biased => True) >=
496 RM_Size (Standard_Positive);
497 end Large_Storage_Type;
499 -- Start of processing for Check_Large
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type (Etype (Disc)) then
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
512 if Is_Limited_Type (Scope (Disc)) then
516 -- Check that it is the high bound
518 if N /= High_Bound (PN)
519 or else No (Discriminant_Default_Value (Disc))
524 -- Check the array allows a large range at this bound. First
529 if Nkind (SI) /= N_Subtype_Indication then
533 T := Entity (Subtype_Mark (SI));
535 if not Is_Array_Type (T) then
539 -- Next, find the dimension
541 TB := First_Index (T);
542 CB := First (Constraints (P));
544 and then Present (TB)
545 and then Present (CB)
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type (Etype (TB)) then
562 -- Warn about the danger
565 ("??creation of & object may raise Storage_Error!",
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
577 N_Discriminant_Association)
579 if Paren_Count (N) > 0 then
581 ("discriminant in constraint must appear alone", N);
583 elsif Nkind (N) = N_Expanded_Name
584 and then Comes_From_Source (N)
587 ("discriminant must appear alone as a direct name", N);
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
598 while not Nkind_In (P, N_Component_Declaration,
599 N_Subtype_Indication,
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind (P) = N_Subtype_Indication
613 and then Nkind_In (Parent (P), N_Component_Definition,
614 N_Derived_Type_Definition)
615 and then D = Constraint (P))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind (P) = N_Subtype_Indication
622 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
623 or else Nkind (P) = N_Entry_Declaration
624 or else Nkind (D) = N_Defining_Identifier
627 ("discriminant in constraint must appear alone", N);
630 end Check_Discriminant_Use;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
638 if Is_Invisible_Operator (N, T) then
639 Error_Msg_NE -- CODEFIX
640 ("operator for} is not directly visible!", N, First_Subtype (T));
641 Error_Msg_N -- CODEFIX
642 ("use clause would make operation legal!", N);
644 end Check_For_Visible_Operator;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name (Pref)
674 and then Ekind (Entity (Pref)) = E_In_Parameter
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version >= Ada_2005
683 and then Is_Entity_Name (Pref)
684 and then Is_Access_Type (Etype (Pref))
685 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
687 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
691 Check_Fully_Declared (Typ, Parent (Pref));
693 end Check_Fully_Declared_Prefix;
695 ------------------------------
696 -- Check_Infinite_Recursion --
697 ------------------------------
699 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
703 function Same_Argument_List return Boolean;
704 -- Check whether list of actuals is identical to list of formals of
705 -- called function (which is also the enclosing scope).
707 ------------------------
708 -- Same_Argument_List --
709 ------------------------
711 function Same_Argument_List return Boolean is
717 if not Is_Entity_Name (Name (N)) then
720 Subp := Entity (Name (N));
723 F := First_Formal (Subp);
724 A := First_Actual (N);
725 while Present (F) and then Present (A) loop
726 if not Is_Entity_Name (A) or else Entity (A) /= F then
735 end Same_Argument_List;
737 -- Start of processing for Check_Infinite_Recursion
740 -- Special case, if this is a procedure call and is a call to the
741 -- current procedure with the same argument list, then this is for
742 -- sure an infinite recursion and we insert a call to raise SE.
744 if Is_List_Member (N)
745 and then List_Length (List_Containing (N)) = 1
746 and then Same_Argument_List
749 P : constant Node_Id := Parent (N);
751 if Nkind (P) = N_Handled_Sequence_Of_Statements
752 and then Nkind (Parent (P)) = N_Subprogram_Body
753 and then Is_Empty_List (Declarations (Parent (P)))
755 Error_Msg_Warn := SPARK_Mode /= On;
756 Error_Msg_N ("!infinite recursion<<", N);
757 Error_Msg_N ("\!Storage_Error [<<", N);
759 Make_Raise_Storage_Error (Sloc (N),
760 Reason => SE_Infinite_Recursion));
766 -- If not that special case, search up tree, quitting if we reach a
767 -- construct (e.g. a conditional) that tells us that this is not a
768 -- case for an infinite recursion warning.
774 -- If no parent, then we were not inside a subprogram, this can for
775 -- example happen when processing certain pragmas in a spec. Just
776 -- return False in this case.
782 -- Done if we get to subprogram body, this is definitely an infinite
783 -- recursion case if we did not find anything to stop us.
785 exit when Nkind (P) = N_Subprogram_Body;
787 -- If appearing in conditional, result is false
789 if Nkind_In (P, N_Or_Else,
798 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
799 and then C /= First (Statements (P))
801 -- If the call is the expression of a return statement and the
802 -- actuals are identical to the formals, it's worth a warning.
803 -- However, we skip this if there is an immediately preceding
804 -- raise statement, since the call is never executed.
806 -- Furthermore, this corresponds to a common idiom:
808 -- function F (L : Thing) return Boolean is
810 -- raise Program_Error;
814 -- for generating a stub function
816 if Nkind (Parent (N)) = N_Simple_Return_Statement
817 and then Same_Argument_List
819 exit when not Is_List_Member (Parent (N));
821 -- OK, return statement is in a statement list, look for raise
827 -- Skip past N_Freeze_Entity nodes generated by expansion
829 Nod := Prev (Parent (N));
831 and then Nkind (Nod) = N_Freeze_Entity
836 -- If no raise statement, give warning. We look at the
837 -- original node, because in the case of "raise ... with
838 -- ...", the node has been transformed into a call.
840 exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
842 (Nkind (Nod) not in N_Raise_xxx_Error
843 or else Present (Condition (Nod)));
854 Error_Msg_Warn := SPARK_Mode /= On;
855 Error_Msg_N ("!possible infinite recursion<<", N);
856 Error_Msg_N ("\!??Storage_Error ]<<", N);
859 end Check_Infinite_Recursion;
861 -------------------------------
862 -- Check_Initialization_Call --
863 -------------------------------
865 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
866 Typ : constant Entity_Id := Etype (First_Formal (Nam));
868 function Uses_SS (T : Entity_Id) return Boolean;
869 -- Check whether the creation of an object of the type will involve
870 -- use of the secondary stack. If T is a record type, this is true
871 -- if the expression for some component uses the secondary stack, e.g.
872 -- through a call to a function that returns an unconstrained value.
873 -- False if T is controlled, because cleanups occur elsewhere.
879 function Uses_SS (T : Entity_Id) return Boolean is
882 Full_Type : Entity_Id := Underlying_Type (T);
885 -- Normally we want to use the underlying type, but if it's not set
886 -- then continue with T.
888 if not Present (Full_Type) then
892 if Is_Controlled (Full_Type) then
895 elsif Is_Array_Type (Full_Type) then
896 return Uses_SS (Component_Type (Full_Type));
898 elsif Is_Record_Type (Full_Type) then
899 Comp := First_Component (Full_Type);
900 while Present (Comp) loop
901 if Ekind (Comp) = E_Component
902 and then Nkind (Parent (Comp)) = N_Component_Declaration
904 -- The expression for a dynamic component may be rewritten
905 -- as a dereference, so retrieve original node.
907 Expr := Original_Node (Expression (Parent (Comp)));
909 -- Return True if the expression is a call to a function
910 -- (including an attribute function such as Image, or a
911 -- user-defined operator) with a result that requires a
914 if (Nkind (Expr) = N_Function_Call
915 or else Nkind (Expr) in N_Op
916 or else (Nkind (Expr) = N_Attribute_Reference
917 and then Present (Expressions (Expr))))
918 and then Requires_Transient_Scope (Etype (Expr))
922 elsif Uses_SS (Etype (Comp)) then
927 Next_Component (Comp);
937 -- Start of processing for Check_Initialization_Call
940 -- Establish a transient scope if the type needs it
942 if Uses_SS (Typ) then
943 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
945 end Check_Initialization_Call;
947 ---------------------------------------
948 -- Check_No_Direct_Boolean_Operators --
949 ---------------------------------------
951 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
953 if Scope (Entity (N)) = Standard_Standard
954 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
956 -- Restriction only applies to original source code
958 if Comes_From_Source (N) then
959 Check_Restriction (No_Direct_Boolean_Operators, N);
963 -- Do style check (but skip if in instance, error is on template)
966 if not In_Instance then
967 Check_Boolean_Operator (N);
970 end Check_No_Direct_Boolean_Operators;
972 ------------------------------
973 -- Check_Parameterless_Call --
974 ------------------------------
976 procedure Check_Parameterless_Call (N : Node_Id) is
979 function Prefix_Is_Access_Subp return Boolean;
980 -- If the prefix is of an access_to_subprogram type, the node must be
981 -- rewritten as a call. Ditto if the prefix is overloaded and all its
982 -- interpretations are access to subprograms.
984 ---------------------------
985 -- Prefix_Is_Access_Subp --
986 ---------------------------
988 function Prefix_Is_Access_Subp return Boolean is
993 -- If the context is an attribute reference that can apply to
994 -- functions, this is never a parameterless call (RM 4.1.4(6)).
996 if Nkind (Parent (N)) = N_Attribute_Reference
997 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1004 if not Is_Overloaded (N) then
1006 Ekind (Etype (N)) = E_Subprogram_Type
1007 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1009 Get_First_Interp (N, I, It);
1010 while Present (It.Typ) loop
1011 if Ekind (It.Typ) /= E_Subprogram_Type
1012 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1017 Get_Next_Interp (I, It);
1022 end Prefix_Is_Access_Subp;
1024 -- Start of processing for Check_Parameterless_Call
1027 -- Defend against junk stuff if errors already detected
1029 if Total_Errors_Detected /= 0 then
1030 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1032 elsif Nkind (N) in N_Has_Chars
1033 and then Chars (N) in Error_Name_Or_No_Name
1041 -- If the context expects a value, and the name is a procedure, this is
1042 -- most likely a missing 'Access. Don't try to resolve the parameterless
1043 -- call, error will be caught when the outer call is analyzed.
1045 if Is_Entity_Name (N)
1046 and then Ekind (Entity (N)) = E_Procedure
1047 and then not Is_Overloaded (N)
1049 Nkind_In (Parent (N), N_Parameter_Association,
1051 N_Procedure_Call_Statement)
1056 -- Rewrite as call if overloadable entity that is (or could be, in the
1057 -- overloaded case) a function call. If we know for sure that the entity
1058 -- is an enumeration literal, we do not rewrite it.
1060 -- If the entity is the name of an operator, it cannot be a call because
1061 -- operators cannot have default parameters. In this case, this must be
1062 -- a string whose contents coincide with an operator name. Set the kind
1063 -- of the node appropriately.
1065 if (Is_Entity_Name (N)
1066 and then Nkind (N) /= N_Operator_Symbol
1067 and then Is_Overloadable (Entity (N))
1068 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1069 or else Is_Overloaded (N)))
1071 -- Rewrite as call if it is an explicit dereference of an expression of
1072 -- a subprogram access type, and the subprogram type is not that of a
1073 -- procedure or entry.
1076 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1078 -- Rewrite as call if it is a selected component which is a function,
1079 -- this is the case of a call to a protected function (which may be
1080 -- overloaded with other protected operations).
1083 (Nkind (N) = N_Selected_Component
1084 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1086 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1088 and then Is_Overloaded (Selector_Name (N)))))
1090 -- If one of the above three conditions is met, rewrite as call. Apply
1091 -- the rewriting only once.
1094 if Nkind (Parent (N)) /= N_Function_Call
1095 or else N /= Name (Parent (N))
1098 -- This may be a prefixed call that was not fully analyzed, e.g.
1099 -- an actual in an instance.
1101 if Ada_Version >= Ada_2005
1102 and then Nkind (N) = N_Selected_Component
1103 and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
1105 Analyze_Selected_Component (N);
1107 if Nkind (N) /= N_Selected_Component then
1112 -- The node is the name of the parameterless call. Preserve its
1113 -- descendants, which may be complex expressions.
1115 Nam := Relocate_Node (N);
1117 -- If overloaded, overload set belongs to new copy
1119 Save_Interps (N, Nam);
1121 -- Change node to parameterless function call (note that the
1122 -- Parameter_Associations associations field is left set to Empty,
1123 -- its normal default value since there are no parameters)
1125 Change_Node (N, N_Function_Call);
1127 Set_Sloc (N, Sloc (Nam));
1131 elsif Nkind (N) = N_Parameter_Association then
1132 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1134 elsif Nkind (N) = N_Operator_Symbol then
1135 Change_Operator_Symbol_To_String_Literal (N);
1136 Set_Is_Overloaded (N, False);
1137 Set_Etype (N, Any_String);
1139 end Check_Parameterless_Call;
1141 --------------------------------
1142 -- Is_Atomic_Ref_With_Address --
1143 --------------------------------
1145 function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
1146 Pref : constant Node_Id := Prefix (N);
1149 if not Is_Entity_Name (Pref) then
1154 Pent : constant Entity_Id := Entity (Pref);
1155 Ptyp : constant Entity_Id := Etype (Pent);
1157 return not Is_Access_Type (Ptyp)
1158 and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
1159 and then Present (Address_Clause (Pent));
1162 end Is_Atomic_Ref_With_Address;
1164 -----------------------------
1165 -- Is_Definite_Access_Type --
1166 -----------------------------
1168 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1169 Btyp : constant Entity_Id := Base_Type (E);
1171 return Ekind (Btyp) = E_Access_Type
1172 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1173 and then Comes_From_Source (Btyp));
1174 end Is_Definite_Access_Type;
1176 ----------------------
1177 -- Is_Predefined_Op --
1178 ----------------------
1180 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1182 -- Predefined operators are intrinsic subprograms
1184 if not Is_Intrinsic_Subprogram (Nam) then
1188 -- A call to a back-end builtin is never a predefined operator
1190 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1194 return not Is_Generic_Instance (Nam)
1195 and then Chars (Nam) in Any_Operator_Name
1196 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
1197 end Is_Predefined_Op;
1199 -----------------------------
1200 -- Make_Call_Into_Operator --
1201 -----------------------------
1203 procedure Make_Call_Into_Operator
1208 Op_Name : constant Name_Id := Chars (Op_Id);
1209 Act1 : Node_Id := First_Actual (N);
1210 Act2 : Node_Id := Next_Actual (Act1);
1211 Error : Boolean := False;
1212 Func : constant Entity_Id := Entity (Name (N));
1213 Is_Binary : constant Boolean := Present (Act2);
1215 Opnd_Type : Entity_Id;
1216 Orig_Type : Entity_Id := Empty;
1219 type Kind_Test is access function (E : Entity_Id) return Boolean;
1221 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1222 -- If the operand is not universal, and the operator is given by an
1223 -- expanded name, verify that the operand has an interpretation with a
1224 -- type defined in the given scope of the operator.
1226 function Type_In_P (Test : Kind_Test) return Entity_Id;
1227 -- Find a type of the given class in package Pack that contains the
1230 ---------------------------
1231 -- Operand_Type_In_Scope --
1232 ---------------------------
1234 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1235 Nod : constant Node_Id := Right_Opnd (Op_Node);
1240 if not Is_Overloaded (Nod) then
1241 return Scope (Base_Type (Etype (Nod))) = S;
1244 Get_First_Interp (Nod, I, It);
1245 while Present (It.Typ) loop
1246 if Scope (Base_Type (It.Typ)) = S then
1250 Get_Next_Interp (I, It);
1255 end Operand_Type_In_Scope;
1261 function Type_In_P (Test : Kind_Test) return Entity_Id is
1264 function In_Decl return Boolean;
1265 -- Verify that node is not part of the type declaration for the
1266 -- candidate type, which would otherwise be invisible.
1272 function In_Decl return Boolean is
1273 Decl_Node : constant Node_Id := Parent (E);
1279 if Etype (E) = Any_Type then
1282 elsif No (Decl_Node) then
1287 and then Nkind (N2) /= N_Compilation_Unit
1289 if N2 = Decl_Node then
1300 -- Start of processing for Type_In_P
1303 -- If the context type is declared in the prefix package, this is the
1304 -- desired base type.
1306 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
1307 return Base_Type (Typ);
1310 E := First_Entity (Pack);
1311 while Present (E) loop
1312 if Test (E) and then not In_Decl then
1323 -- Start of processing for Make_Call_Into_Operator
1326 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1331 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1332 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1333 Save_Interps (Act1, Left_Opnd (Op_Node));
1334 Save_Interps (Act2, Right_Opnd (Op_Node));
1335 Act1 := Left_Opnd (Op_Node);
1336 Act2 := Right_Opnd (Op_Node);
1341 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1342 Save_Interps (Act1, Right_Opnd (Op_Node));
1343 Act1 := Right_Opnd (Op_Node);
1346 -- If the operator is denoted by an expanded name, and the prefix is
1347 -- not Standard, but the operator is a predefined one whose scope is
1348 -- Standard, then this is an implicit_operator, inserted as an
1349 -- interpretation by the procedure of the same name. This procedure
1350 -- overestimates the presence of implicit operators, because it does
1351 -- not examine the type of the operands. Verify now that the operand
1352 -- type appears in the given scope. If right operand is universal,
1353 -- check the other operand. In the case of concatenation, either
1354 -- argument can be the component type, so check the type of the result.
1355 -- If both arguments are literals, look for a type of the right kind
1356 -- defined in the given scope. This elaborate nonsense is brought to
1357 -- you courtesy of b33302a. The type itself must be frozen, so we must
1358 -- find the type of the proper class in the given scope.
1360 -- A final wrinkle is the multiplication operator for fixed point types,
1361 -- which is defined in Standard only, and not in the scope of the
1362 -- fixed point type itself.
1364 if Nkind (Name (N)) = N_Expanded_Name then
1365 Pack := Entity (Prefix (Name (N)));
1367 -- If this is a package renaming, get renamed entity, which will be
1368 -- the scope of the operands if operaton is type-correct.
1370 if Present (Renamed_Entity (Pack)) then
1371 Pack := Renamed_Entity (Pack);
1374 -- If the entity being called is defined in the given package, it is
1375 -- a renaming of a predefined operator, and known to be legal.
1377 if Scope (Entity (Name (N))) = Pack
1378 and then Pack /= Standard_Standard
1382 -- Visibility does not need to be checked in an instance: if the
1383 -- operator was not visible in the generic it has been diagnosed
1384 -- already, else there is an implicit copy of it in the instance.
1386 elsif In_Instance then
1389 elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1390 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1391 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1393 if Pack /= Standard_Standard then
1397 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1400 elsif Ada_Version >= Ada_2005
1401 and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1402 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1407 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1409 if Op_Name = Name_Op_Concat then
1410 Opnd_Type := Base_Type (Typ);
1412 elsif (Scope (Opnd_Type) = Standard_Standard
1414 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1416 and then not Comes_From_Source (Opnd_Type))
1418 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1421 if Scope (Opnd_Type) = Standard_Standard then
1423 -- Verify that the scope contains a type that corresponds to
1424 -- the given literal. Optimize the case where Pack is Standard.
1426 if Pack /= Standard_Standard then
1428 if Opnd_Type = Universal_Integer then
1429 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1431 elsif Opnd_Type = Universal_Real then
1432 Orig_Type := Type_In_P (Is_Real_Type'Access);
1434 elsif Opnd_Type = Any_String then
1435 Orig_Type := Type_In_P (Is_String_Type'Access);
1437 elsif Opnd_Type = Any_Access then
1438 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1440 elsif Opnd_Type = Any_Composite then
1441 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1443 if Present (Orig_Type) then
1444 if Has_Private_Component (Orig_Type) then
1447 Set_Etype (Act1, Orig_Type);
1450 Set_Etype (Act2, Orig_Type);
1459 Error := No (Orig_Type);
1462 elsif Ekind (Opnd_Type) = E_Allocator_Type
1463 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1467 -- If the type is defined elsewhere, and the operator is not
1468 -- defined in the given scope (by a renaming declaration, e.g.)
1469 -- then this is an error as well. If an extension of System is
1470 -- present, and the type may be defined there, Pack must be
1473 elsif Scope (Opnd_Type) /= Pack
1474 and then Scope (Op_Id) /= Pack
1475 and then (No (System_Aux_Id)
1476 or else Scope (Opnd_Type) /= System_Aux_Id
1477 or else Pack /= Scope (System_Aux_Id))
1479 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1482 Error := not Operand_Type_In_Scope (Pack);
1485 elsif Pack = Standard_Standard
1486 and then not Operand_Type_In_Scope (Standard_Standard)
1493 Error_Msg_Node_2 := Pack;
1495 ("& not declared in&", N, Selector_Name (Name (N)));
1496 Set_Etype (N, Any_Type);
1499 -- Detect a mismatch between the context type and the result type
1500 -- in the named package, which is otherwise not detected if the
1501 -- operands are universal. Check is only needed if source entity is
1502 -- an operator, not a function that renames an operator.
1504 elsif Nkind (Parent (N)) /= N_Type_Conversion
1505 and then Ekind (Entity (Name (N))) = E_Operator
1506 and then Is_Numeric_Type (Typ)
1507 and then not Is_Universal_Numeric_Type (Typ)
1508 and then Scope (Base_Type (Typ)) /= Pack
1509 and then not In_Instance
1511 if Is_Fixed_Point_Type (Typ)
1512 and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
1514 -- Already checked above
1518 -- Operator may be defined in an extension of System
1520 elsif Present (System_Aux_Id)
1521 and then Scope (Opnd_Type) = System_Aux_Id
1526 -- Could we use Wrong_Type here??? (this would require setting
1527 -- Etype (N) to the actual type found where Typ was expected).
1529 Error_Msg_NE ("expect }", N, Typ);
1534 Set_Chars (Op_Node, Op_Name);
1536 if not Is_Private_Type (Etype (N)) then
1537 Set_Etype (Op_Node, Base_Type (Etype (N)));
1539 Set_Etype (Op_Node, Etype (N));
1542 -- If this is a call to a function that renames a predefined equality,
1543 -- the renaming declaration provides a type that must be used to
1544 -- resolve the operands. This must be done now because resolution of
1545 -- the equality node will not resolve any remaining ambiguity, and it
1546 -- assumes that the first operand is not overloaded.
1548 if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
1549 and then Ekind (Func) = E_Function
1550 and then Is_Overloaded (Act1)
1552 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1553 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1556 Set_Entity (Op_Node, Op_Id);
1557 Generate_Reference (Op_Id, N, ' ');
1559 -- Do rewrite setting Comes_From_Source on the result if the original
1560 -- call came from source. Although it is not strictly the case that the
1561 -- operator as such comes from the source, logically it corresponds
1562 -- exactly to the function call in the source, so it should be marked
1563 -- this way (e.g. to make sure that validity checks work fine).
1566 CS : constant Boolean := Comes_From_Source (N);
1568 Rewrite (N, Op_Node);
1569 Set_Comes_From_Source (N, CS);
1572 -- If this is an arithmetic operator and the result type is private,
1573 -- the operands and the result must be wrapped in conversion to
1574 -- expose the underlying numeric type and expand the proper checks,
1575 -- e.g. on division.
1577 if Is_Private_Type (Typ) then
1579 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1580 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1581 Resolve_Intrinsic_Operator (N, Typ);
1583 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1584 Resolve_Intrinsic_Unary_Operator (N, Typ);
1593 -- If in ASIS_Mode, propagate operand types to original actuals of
1594 -- function call, which would otherwise not be fully resolved. If
1595 -- the call has already been constant-folded, nothing to do. We
1596 -- relocate the operand nodes rather than copy them, to preserve
1597 -- original_node pointers, given that the operands themselves may
1598 -- have been rewritten. If the call was itself a rewriting of an
1599 -- operator node, nothing to do.
1602 and then Nkind (N) in N_Op
1603 and then Nkind (Original_Node (N)) = N_Function_Call
1607 R : constant Node_Id := Right_Opnd (N);
1609 Old_First : constant Node_Id :=
1610 First (Parameter_Associations (Original_Node (N)));
1616 Old_Sec := Next (Old_First);
1618 -- If the original call has named associations, replace the
1619 -- explicit actual parameter in the association with the proper
1620 -- resolved operand.
1622 if Nkind (Old_First) = N_Parameter_Association then
1623 if Chars (Selector_Name (Old_First)) =
1624 Chars (First_Entity (Op_Id))
1626 Rewrite (Explicit_Actual_Parameter (Old_First),
1629 Rewrite (Explicit_Actual_Parameter (Old_First),
1634 Rewrite (Old_First, Relocate_Node (L));
1637 if Nkind (Old_Sec) = N_Parameter_Association then
1638 if Chars (Selector_Name (Old_Sec)) =
1639 Chars (First_Entity (Op_Id))
1641 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1644 Rewrite (Explicit_Actual_Parameter (Old_Sec),
1649 Rewrite (Old_Sec, Relocate_Node (R));
1653 if Nkind (Old_First) = N_Parameter_Association then
1654 Rewrite (Explicit_Actual_Parameter (Old_First),
1657 Rewrite (Old_First, Relocate_Node (R));
1662 Set_Parent (Original_Node (N), Parent (N));
1664 end Make_Call_Into_Operator;
1670 function Operator_Kind
1672 Is_Binary : Boolean) return Node_Kind
1677 -- Use CASE statement or array???
1680 if Op_Name = Name_Op_And then
1682 elsif Op_Name = Name_Op_Or then
1684 elsif Op_Name = Name_Op_Xor then
1686 elsif Op_Name = Name_Op_Eq then
1688 elsif Op_Name = Name_Op_Ne then
1690 elsif Op_Name = Name_Op_Lt then
1692 elsif Op_Name = Name_Op_Le then
1694 elsif Op_Name = Name_Op_Gt then
1696 elsif Op_Name = Name_Op_Ge then
1698 elsif Op_Name = Name_Op_Add then
1700 elsif Op_Name = Name_Op_Subtract then
1701 Kind := N_Op_Subtract;
1702 elsif Op_Name = Name_Op_Concat then
1703 Kind := N_Op_Concat;
1704 elsif Op_Name = Name_Op_Multiply then
1705 Kind := N_Op_Multiply;
1706 elsif Op_Name = Name_Op_Divide then
1707 Kind := N_Op_Divide;
1708 elsif Op_Name = Name_Op_Mod then
1710 elsif Op_Name = Name_Op_Rem then
1712 elsif Op_Name = Name_Op_Expon then
1715 raise Program_Error;
1721 if Op_Name = Name_Op_Add then
1723 elsif Op_Name = Name_Op_Subtract then
1725 elsif Op_Name = Name_Op_Abs then
1727 elsif Op_Name = Name_Op_Not then
1730 raise Program_Error;
1737 ----------------------------
1738 -- Preanalyze_And_Resolve --
1739 ----------------------------
1741 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1742 Save_Full_Analysis : constant Boolean := Full_Analysis;
1745 Full_Analysis := False;
1746 Expander_Mode_Save_And_Set (False);
1748 -- Normally, we suppress all checks for this preanalysis. There is no
1749 -- point in processing them now, since they will be applied properly
1750 -- and in the proper location when the default expressions reanalyzed
1751 -- and reexpanded later on. We will also have more information at that
1752 -- point for possible suppression of individual checks.
1754 -- However, in SPARK mode, most expansion is suppressed, and this
1755 -- later reanalysis and reexpansion may not occur. SPARK mode does
1756 -- require the setting of checking flags for proof purposes, so we
1757 -- do the SPARK preanalysis without suppressing checks.
1759 -- This special handling for SPARK mode is required for example in the
1760 -- case of Ada 2012 constructs such as quantified expressions, which are
1761 -- expanded in two separate steps.
1763 if GNATprove_Mode then
1764 Analyze_And_Resolve (N, T);
1766 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1769 Expander_Mode_Restore;
1770 Full_Analysis := Save_Full_Analysis;
1771 end Preanalyze_And_Resolve;
1773 -- Version without context type
1775 procedure Preanalyze_And_Resolve (N : Node_Id) is
1776 Save_Full_Analysis : constant Boolean := Full_Analysis;
1779 Full_Analysis := False;
1780 Expander_Mode_Save_And_Set (False);
1783 Resolve (N, Etype (N), Suppress => All_Checks);
1785 Expander_Mode_Restore;
1786 Full_Analysis := Save_Full_Analysis;
1787 end Preanalyze_And_Resolve;
1789 ----------------------------------
1790 -- Replace_Actual_Discriminants --
1791 ----------------------------------
1793 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1794 Loc : constant Source_Ptr := Sloc (N);
1795 Tsk : Node_Id := Empty;
1797 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1798 -- Comment needed???
1804 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1808 if Nkind (Nod) = N_Identifier then
1809 Ent := Entity (Nod);
1812 and then Ekind (Ent) = E_Discriminant
1815 Make_Selected_Component (Loc,
1816 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1817 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1819 Set_Etype (Nod, Etype (Ent));
1827 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1829 -- Start of processing for Replace_Actual_Discriminants
1832 if not Expander_Active then
1836 if Nkind (Name (N)) = N_Selected_Component then
1837 Tsk := Prefix (Name (N));
1839 elsif Nkind (Name (N)) = N_Indexed_Component then
1840 Tsk := Prefix (Prefix (Name (N)));
1846 Replace_Discrs (Default);
1848 end Replace_Actual_Discriminants;
1854 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1855 Ambiguous : Boolean := False;
1856 Ctx_Type : Entity_Id := Typ;
1857 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1858 Err_Type : Entity_Id := Empty;
1859 Found : Boolean := False;
1862 I1 : Interp_Index := 0; -- prevent junk warning
1865 Seen : Entity_Id := Empty; -- prevent junk warning
1867 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1868 -- Determine whether a node comes from a predefined library unit or
1871 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1872 -- Try and fix up a literal so that it matches its expected type. New
1873 -- literals are manufactured if necessary to avoid cascaded errors.
1875 procedure Report_Ambiguous_Argument;
1876 -- Additional diagnostics when an ambiguous call has an ambiguous
1877 -- argument (typically a controlling actual).
1879 procedure Resolution_Failed;
1880 -- Called when attempt at resolving current expression fails
1882 ------------------------------------
1883 -- Comes_From_Predefined_Lib_Unit --
1884 -------------------------------------
1886 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1889 Sloc (Nod) = Standard_Location
1890 or else Is_Predefined_File_Name
1891 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
1892 end Comes_From_Predefined_Lib_Unit;
1894 --------------------
1895 -- Patch_Up_Value --
1896 --------------------
1898 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1900 if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
1902 Make_Real_Literal (Sloc (N),
1903 Realval => UR_From_Uint (Intval (N))));
1904 Set_Etype (N, Universal_Real);
1905 Set_Is_Static_Expression (N);
1907 elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
1909 Make_Integer_Literal (Sloc (N),
1910 Intval => UR_To_Uint (Realval (N))));
1911 Set_Etype (N, Universal_Integer);
1912 Set_Is_Static_Expression (N);
1914 elsif Nkind (N) = N_String_Literal
1915 and then Is_Character_Type (Typ)
1917 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1919 Make_Character_Literal (Sloc (N),
1921 Char_Literal_Value =>
1922 UI_From_Int (Character'Pos ('A'))));
1923 Set_Etype (N, Any_Character);
1924 Set_Is_Static_Expression (N);
1926 elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
1928 Make_String_Literal (Sloc (N),
1929 Strval => End_String));
1931 elsif Nkind (N) = N_Range then
1932 Patch_Up_Value (Low_Bound (N), Typ);
1933 Patch_Up_Value (High_Bound (N), Typ);
1937 -------------------------------
1938 -- Report_Ambiguous_Argument --
1939 -------------------------------
1941 procedure Report_Ambiguous_Argument is
1942 Arg : constant Node_Id := First (Parameter_Associations (N));
1947 if Nkind (Arg) = N_Function_Call
1948 and then Is_Entity_Name (Name (Arg))
1949 and then Is_Overloaded (Name (Arg))
1951 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
1953 -- Could use comments on what is going on here???
1955 Get_First_Interp (Name (Arg), I, It);
1956 while Present (It.Nam) loop
1957 Error_Msg_Sloc := Sloc (It.Nam);
1959 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
1960 Error_Msg_N ("interpretation (inherited) #!", Arg);
1962 Error_Msg_N ("interpretation #!", Arg);
1965 Get_Next_Interp (I, It);
1968 end Report_Ambiguous_Argument;
1970 -----------------------
1971 -- Resolution_Failed --
1972 -----------------------
1974 procedure Resolution_Failed is
1976 Patch_Up_Value (N, Typ);
1978 -- Set the type to the desired one to minimize cascaded errors. Note
1979 -- that this is an approximation and does not work in all cases.
1983 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1984 Set_Is_Overloaded (N, False);
1986 -- The caller will return without calling the expander, so we need
1987 -- to set the analyzed flag. Note that it is fine to set Analyzed
1988 -- to True even if we are in the middle of a shallow analysis,
1989 -- (see the spec of sem for more details) since this is an error
1990 -- situation anyway, and there is no point in repeating the
1991 -- analysis later (indeed it won't work to repeat it later, since
1992 -- we haven't got a clear resolution of which entity is being
1995 Set_Analyzed (N, True);
1997 end Resolution_Failed;
1999 -- Start of processing for Resolve
2006 -- Access attribute on remote subprogram cannot be used for a non-remote
2007 -- access-to-subprogram type.
2009 if Nkind (N) = N_Attribute_Reference
2010 and then Nam_In (Attribute_Name (N), Name_Access,
2011 Name_Unrestricted_Access,
2012 Name_Unchecked_Access)
2013 and then Comes_From_Source (N)
2014 and then Is_Entity_Name (Prefix (N))
2015 and then Is_Subprogram (Entity (Prefix (N)))
2016 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
2017 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
2020 ("prefix must statically denote a non-remote subprogram", N);
2023 From_Lib := Comes_From_Predefined_Lib_Unit (N);
2025 -- If the context is a Remote_Access_To_Subprogram, access attributes
2026 -- must be resolved with the corresponding fat pointer. There is no need
2027 -- to check for the attribute name since the return type of an
2028 -- attribute is never a remote type.
2030 if Nkind (N) = N_Attribute_Reference
2031 and then Comes_From_Source (N)
2032 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
2035 Attr : constant Attribute_Id :=
2036 Get_Attribute_Id (Attribute_Name (N));
2037 Pref : constant Node_Id := Prefix (N);
2040 Is_Remote : Boolean := True;
2043 -- Check that Typ is a remote access-to-subprogram type
2045 if Is_Remote_Access_To_Subprogram_Type (Typ) then
2047 -- Prefix (N) must statically denote a remote subprogram
2048 -- declared in a package specification.
2050 if Attr = Attribute_Access or else
2051 Attr = Attribute_Unchecked_Access or else
2052 Attr = Attribute_Unrestricted_Access
2054 Decl := Unit_Declaration_Node (Entity (Pref));
2056 if Nkind (Decl) = N_Subprogram_Body then
2057 Spec := Corresponding_Spec (Decl);
2059 if Present (Spec) then
2060 Decl := Unit_Declaration_Node (Spec);
2064 Spec := Parent (Decl);
2066 if not Is_Entity_Name (Prefix (N))
2067 or else Nkind (Spec) /= N_Package_Specification
2069 not Is_Remote_Call_Interface (Defining_Entity (Spec))
2073 ("prefix must statically denote a remote subprogram ",
2077 -- If we are generating code in distributed mode, perform
2078 -- semantic checks against corresponding remote entities.
2081 and then Get_PCS_Name /= Name_No_DSA
2083 Check_Subtype_Conformant
2084 (New_Id => Entity (Prefix (N)),
2085 Old_Id => Designated_Type
2086 (Corresponding_Remote_Type (Typ)),
2090 Process_Remote_AST_Attribute (N, Typ);
2098 Debug_A_Entry ("resolving ", N);
2100 if Debug_Flag_V then
2101 Write_Overloads (N);
2104 if Comes_From_Source (N) then
2105 if Is_Fixed_Point_Type (Typ) then
2106 Check_Restriction (No_Fixed_Point, N);
2108 elsif Is_Floating_Point_Type (Typ)
2109 and then Typ /= Universal_Real
2110 and then Typ /= Any_Real
2112 Check_Restriction (No_Floating_Point, N);
2116 -- Return if already analyzed
2118 if Analyzed (N) then
2119 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2120 Analyze_Dimension (N);
2123 -- Any case of Any_Type as the Etype value means that we had a
2126 elsif Etype (N) = Any_Type then
2127 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2131 Check_Parameterless_Call (N);
2133 -- The resolution of an Expression_With_Actions is determined by
2136 if Nkind (N) = N_Expression_With_Actions then
2137 Resolve (Expression (N), Typ);
2140 Expr_Type := Etype (Expression (N));
2142 -- If not overloaded, then we know the type, and all that needs doing
2143 -- is to check that this type is compatible with the context.
2145 elsif not Is_Overloaded (N) then
2146 Found := Covers (Typ, Etype (N));
2147 Expr_Type := Etype (N);
2149 -- In the overloaded case, we must select the interpretation that
2150 -- is compatible with the context (i.e. the type passed to Resolve)
2153 -- Loop through possible interpretations
2155 Get_First_Interp (N, I, It);
2156 Interp_Loop : while Present (It.Typ) loop
2157 if Debug_Flag_V then
2158 Write_Str ("Interp: ");
2162 -- We are only interested in interpretations that are compatible
2163 -- with the expected type, any other interpretations are ignored.
2165 if not Covers (Typ, It.Typ) then
2166 if Debug_Flag_V then
2167 Write_Str (" interpretation incompatible with context");
2172 -- Skip the current interpretation if it is disabled by an
2173 -- abstract operator. This action is performed only when the
2174 -- type against which we are resolving is the same as the
2175 -- type of the interpretation.
2177 if Ada_Version >= Ada_2005
2178 and then It.Typ = Typ
2179 and then Typ /= Universal_Integer
2180 and then Typ /= Universal_Real
2181 and then Present (It.Abstract_Op)
2183 if Debug_Flag_V then
2184 Write_Line ("Skip.");
2190 -- First matching interpretation
2196 Expr_Type := It.Typ;
2198 -- Matching interpretation that is not the first, maybe an
2199 -- error, but there are some cases where preference rules are
2200 -- used to choose between the two possibilities. These and
2201 -- some more obscure cases are handled in Disambiguate.
2204 -- If the current statement is part of a predefined library
2205 -- unit, then all interpretations which come from user level
2206 -- packages should not be considered. Check previous and
2210 if not Comes_From_Predefined_Lib_Unit (It.Nam) then
2213 elsif not Comes_From_Predefined_Lib_Unit (Seen) then
2215 -- Previous interpretation must be discarded
2219 Expr_Type := It.Typ;
2220 Set_Entity (N, Seen);
2225 -- Otherwise apply further disambiguation steps
2227 Error_Msg_Sloc := Sloc (Seen);
2228 It1 := Disambiguate (N, I1, I, Typ);
2230 -- Disambiguation has succeeded. Skip the remaining
2233 if It1 /= No_Interp then
2235 Expr_Type := It1.Typ;
2237 while Present (It.Typ) loop
2238 Get_Next_Interp (I, It);
2242 -- Before we issue an ambiguity complaint, check for the
2243 -- case of a subprogram call where at least one of the
2244 -- arguments is Any_Type, and if so suppress the message,
2245 -- since it is a cascaded error. This can also happen for
2246 -- a generalized indexing operation.
2248 if Nkind (N) in N_Subprogram_Call
2249 or else (Nkind (N) = N_Indexed_Component
2250 and then Present (Generalized_Indexing (N)))
2257 if Nkind (N) = N_Indexed_Component then
2258 Rewrite (N, Generalized_Indexing (N));
2261 A := First_Actual (N);
2262 while Present (A) loop
2265 if Nkind (E) = N_Parameter_Association then
2266 E := Explicit_Actual_Parameter (E);
2269 if Etype (E) = Any_Type then
2270 if Debug_Flag_V then
2271 Write_Str ("Any_Type in call");
2282 elsif Nkind (N) in N_Binary_Op
2283 and then (Etype (Left_Opnd (N)) = Any_Type
2284 or else Etype (Right_Opnd (N)) = Any_Type)
2288 elsif Nkind (N) in N_Unary_Op
2289 and then Etype (Right_Opnd (N)) = Any_Type
2294 -- Not that special case, so issue message using the flag
2295 -- Ambiguous to control printing of the header message
2296 -- only at the start of an ambiguous set.
2298 if not Ambiguous then
2299 if Nkind (N) = N_Function_Call
2300 and then Nkind (Name (N)) = N_Explicit_Dereference
2303 ("ambiguous expression (cannot resolve indirect "
2306 Error_Msg_NE -- CODEFIX
2307 ("ambiguous expression (cannot resolve&)!",
2313 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2315 ("\\possible interpretation (inherited)#!", N);
2317 Error_Msg_N -- CODEFIX
2318 ("\\possible interpretation#!", N);
2321 if Nkind (N) in N_Subprogram_Call
2322 and then Present (Parameter_Associations (N))
2324 Report_Ambiguous_Argument;
2328 Error_Msg_Sloc := Sloc (It.Nam);
2330 -- By default, the error message refers to the candidate
2331 -- interpretation. But if it is a predefined operator, it
2332 -- is implicitly declared at the declaration of the type
2333 -- of the operand. Recover the sloc of that declaration
2334 -- for the error message.
2336 if Nkind (N) in N_Op
2337 and then Scope (It.Nam) = Standard_Standard
2338 and then not Is_Overloaded (Right_Opnd (N))
2339 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2342 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2344 if Comes_From_Source (Err_Type)
2345 and then Present (Parent (Err_Type))
2347 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2350 elsif Nkind (N) in N_Binary_Op
2351 and then Scope (It.Nam) = Standard_Standard
2352 and then not Is_Overloaded (Left_Opnd (N))
2353 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2356 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2358 if Comes_From_Source (Err_Type)
2359 and then Present (Parent (Err_Type))
2361 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2364 -- If this is an indirect call, use the subprogram_type
2365 -- in the message, to have a meaningful location. Also
2366 -- indicate if this is an inherited operation, created
2367 -- by a type declaration.
2369 elsif Nkind (N) = N_Function_Call
2370 and then Nkind (Name (N)) = N_Explicit_Dereference
2371 and then Is_Type (It.Nam)
2375 Sloc (Associated_Node_For_Itype (Err_Type));
2380 if Nkind (N) in N_Op
2381 and then Scope (It.Nam) = Standard_Standard
2382 and then Present (Err_Type)
2384 -- Special-case the message for universal_fixed
2385 -- operators, which are not declared with the type
2386 -- of the operand, but appear forever in Standard.
2388 if It.Typ = Universal_Fixed
2389 and then Scope (It.Nam) = Standard_Standard
2392 ("\\possible interpretation as universal_fixed "
2393 & "operation (RM 4.5.5 (19))", N);
2396 ("\\possible interpretation (predefined)#!", N);
2400 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2403 ("\\possible interpretation (inherited)#!", N);
2405 Error_Msg_N -- CODEFIX
2406 ("\\possible interpretation#!", N);
2412 -- We have a matching interpretation, Expr_Type is the type
2413 -- from this interpretation, and Seen is the entity.
2415 -- For an operator, just set the entity name. The type will be
2416 -- set by the specific operator resolution routine.
2418 if Nkind (N) in N_Op then
2419 Set_Entity (N, Seen);
2420 Generate_Reference (Seen, N);
2422 elsif Nkind (N) = N_Case_Expression then
2423 Set_Etype (N, Expr_Type);
2425 elsif Nkind (N) = N_Character_Literal then
2426 Set_Etype (N, Expr_Type);
2428 elsif Nkind (N) = N_If_Expression then
2429 Set_Etype (N, Expr_Type);
2431 -- AI05-0139-2: Expression is overloaded because type has
2432 -- implicit dereference. If type matches context, no implicit
2433 -- dereference is involved.
2435 elsif Has_Implicit_Dereference (Expr_Type) then
2436 Set_Etype (N, Expr_Type);
2437 Set_Is_Overloaded (N, False);
2440 elsif Is_Overloaded (N)
2441 and then Present (It.Nam)
2442 and then Ekind (It.Nam) = E_Discriminant
2443 and then Has_Implicit_Dereference (It.Nam)
2445 -- If the node is a general indexing, the dereference is
2446 -- is inserted when resolving the rewritten form, else
2449 if Nkind (N) /= N_Indexed_Component
2450 or else No (Generalized_Indexing (N))
2452 Build_Explicit_Dereference (N, It.Nam);
2455 -- For an explicit dereference, attribute reference, range,
2456 -- short-circuit form (which is not an operator node), or call
2457 -- with a name that is an explicit dereference, there is
2458 -- nothing to be done at this point.
2460 elsif Nkind_In (N, N_Explicit_Dereference,
2461 N_Attribute_Reference,
2463 N_Indexed_Component,
2466 N_Selected_Component,
2468 or else Nkind (Name (N)) = N_Explicit_Dereference
2472 -- For procedure or function calls, set the type of the name,
2473 -- and also the entity pointer for the prefix.
2475 elsif Nkind (N) in N_Subprogram_Call
2476 and then Is_Entity_Name (Name (N))
2478 Set_Etype (Name (N), Expr_Type);
2479 Set_Entity (Name (N), Seen);
2480 Generate_Reference (Seen, Name (N));
2482 elsif Nkind (N) = N_Function_Call
2483 and then Nkind (Name (N)) = N_Selected_Component
2485 Set_Etype (Name (N), Expr_Type);
2486 Set_Entity (Selector_Name (Name (N)), Seen);
2487 Generate_Reference (Seen, Selector_Name (Name (N)));
2489 -- For all other cases, just set the type of the Name
2492 Set_Etype (Name (N), Expr_Type);
2499 -- Move to next interpretation
2501 exit Interp_Loop when No (It.Typ);
2503 Get_Next_Interp (I, It);
2504 end loop Interp_Loop;
2507 -- At this stage Found indicates whether or not an acceptable
2508 -- interpretation exists. If not, then we have an error, except that if
2509 -- the context is Any_Type as a result of some other error, then we
2510 -- suppress the error report.
2513 if Typ /= Any_Type then
2515 -- If type we are looking for is Void, then this is the procedure
2516 -- call case, and the error is simply that what we gave is not a
2517 -- procedure name (we think of procedure calls as expressions with
2518 -- types internally, but the user doesn't think of them this way).
2520 if Typ = Standard_Void_Type then
2522 -- Special case message if function used as a procedure
2524 if Nkind (N) = N_Procedure_Call_Statement
2525 and then Is_Entity_Name (Name (N))
2526 and then Ekind (Entity (Name (N))) = E_Function
2529 ("cannot use function & in a procedure call",
2530 Name (N), Entity (Name (N)));
2532 -- Otherwise give general message (not clear what cases this
2533 -- covers, but no harm in providing for them).
2536 Error_Msg_N ("expect procedure name in procedure call", N);
2541 -- Otherwise we do have a subexpression with the wrong type
2543 -- Check for the case of an allocator which uses an access type
2544 -- instead of the designated type. This is a common error and we
2545 -- specialize the message, posting an error on the operand of the
2546 -- allocator, complaining that we expected the designated type of
2549 elsif Nkind (N) = N_Allocator
2550 and then Is_Access_Type (Typ)
2551 and then Is_Access_Type (Etype (N))
2552 and then Designated_Type (Etype (N)) = Typ
2554 Wrong_Type (Expression (N), Designated_Type (Typ));
2557 -- Check for view mismatch on Null in instances, for which the
2558 -- view-swapping mechanism has no identifier.
2560 elsif (In_Instance or else In_Inlined_Body)
2561 and then (Nkind (N) = N_Null)
2562 and then Is_Private_Type (Typ)
2563 and then Is_Access_Type (Full_View (Typ))
2565 Resolve (N, Full_View (Typ));
2569 -- Check for an aggregate. Sometimes we can get bogus aggregates
2570 -- from misuse of parentheses, and we are about to complain about
2571 -- the aggregate without even looking inside it.
2573 -- Instead, if we have an aggregate of type Any_Composite, then
2574 -- analyze and resolve the component fields, and then only issue
2575 -- another message if we get no errors doing this (otherwise
2576 -- assume that the errors in the aggregate caused the problem).
2578 elsif Nkind (N) = N_Aggregate
2579 and then Etype (N) = Any_Composite
2581 -- Disable expansion in any case. If there is a type mismatch
2582 -- it may be fatal to try to expand the aggregate. The flag
2583 -- would otherwise be set to false when the error is posted.
2585 Expander_Active := False;
2588 procedure Check_Aggr (Aggr : Node_Id);
2589 -- Check one aggregate, and set Found to True if we have a
2590 -- definite error in any of its elements
2592 procedure Check_Elmt (Aelmt : Node_Id);
2593 -- Check one element of aggregate and set Found to True if
2594 -- we definitely have an error in the element.
2600 procedure Check_Aggr (Aggr : Node_Id) is
2604 if Present (Expressions (Aggr)) then
2605 Elmt := First (Expressions (Aggr));
2606 while Present (Elmt) loop
2612 if Present (Component_Associations (Aggr)) then
2613 Elmt := First (Component_Associations (Aggr));
2614 while Present (Elmt) loop
2616 -- If this is a default-initialized component, then
2617 -- there is nothing to check. The box will be
2618 -- replaced by the appropriate call during late
2621 if not Box_Present (Elmt) then
2622 Check_Elmt (Expression (Elmt));
2634 procedure Check_Elmt (Aelmt : Node_Id) is
2636 -- If we have a nested aggregate, go inside it (to
2637 -- attempt a naked analyze-resolve of the aggregate can
2638 -- cause undesirable cascaded errors). Do not resolve
2639 -- expression if it needs a type from context, as for
2640 -- integer * fixed expression.
2642 if Nkind (Aelmt) = N_Aggregate then
2648 if not Is_Overloaded (Aelmt)
2649 and then Etype (Aelmt) /= Any_Fixed
2654 if Etype (Aelmt) = Any_Type then
2665 -- Looks like we have a type error, but check for special case
2666 -- of Address wanted, integer found, with the configuration pragma
2667 -- Allow_Integer_Address active. If we have this case, introduce
2668 -- an unchecked conversion to allow the integer expression to be
2669 -- treated as an Address. The reverse case of integer wanted,
2670 -- Address found, is treated in an analogous manner.
2672 if Address_Integer_Convert_OK (Typ, Etype (N)) then
2673 Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
2674 Analyze_And_Resolve (N, Typ);
2677 -- Under relaxed RM semantics silently replace occurrences of null
2678 -- by System.Address_Null.
2680 elsif Null_To_Null_Address_Convert_OK (N, Typ) then
2681 Replace_Null_By_Null_Address (N);
2682 Analyze_And_Resolve (N, Typ);
2686 -- That special Allow_Integer_Address check did not apply, so we
2687 -- have a real type error. If an error message was issued already,
2688 -- Found got reset to True, so if it's still False, issue standard
2689 -- Wrong_Type message.
2692 if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
2694 Subp_Name : Node_Id;
2697 if Is_Entity_Name (Name (N)) then
2698 Subp_Name := Name (N);
2700 elsif Nkind (Name (N)) = N_Selected_Component then
2702 -- Protected operation: retrieve operation name
2704 Subp_Name := Selector_Name (Name (N));
2707 raise Program_Error;
2710 Error_Msg_Node_2 := Typ;
2712 ("no visible interpretation of& matches expected type&",
2716 if All_Errors_Mode then
2718 Index : Interp_Index;
2722 Error_Msg_N ("\\possible interpretations:", N);
2724 Get_First_Interp (Name (N), Index, It);
2725 while Present (It.Nam) loop
2726 Error_Msg_Sloc := Sloc (It.Nam);
2727 Error_Msg_Node_2 := It.Nam;
2729 ("\\ type& for & declared#", N, It.Typ);
2730 Get_Next_Interp (Index, It);
2735 Error_Msg_N ("\use -gnatf for details", N);
2739 Wrong_Type (N, Typ);
2747 -- Test if we have more than one interpretation for the context
2749 elsif Ambiguous then
2753 -- Only one intepretation
2756 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2757 -- the "+" on T is abstract, and the operands are of universal type,
2758 -- the above code will have (incorrectly) resolved the "+" to the
2759 -- universal one in Standard. Therefore check for this case and give
2760 -- an error. We can't do this earlier, because it would cause legal
2761 -- cases to get errors (when some other type has an abstract "+").
2763 if Ada_Version >= Ada_2005
2764 and then Nkind (N) in N_Op
2765 and then Is_Overloaded (N)
2766 and then Is_Universal_Numeric_Type (Etype (Entity (N)))
2768 Get_First_Interp (N, I, It);
2769 while Present (It.Typ) loop
2770 if Present (It.Abstract_Op) and then
2771 Etype (It.Abstract_Op) = Typ
2774 ("cannot call abstract subprogram &!", N, It.Abstract_Op);
2778 Get_Next_Interp (I, It);
2782 -- Here we have an acceptable interpretation for the context
2784 -- Propagate type information and normalize tree for various
2785 -- predefined operations. If the context only imposes a class of
2786 -- types, rather than a specific type, propagate the actual type
2789 if Typ = Any_Integer or else
2790 Typ = Any_Boolean or else
2791 Typ = Any_Modular or else
2792 Typ = Any_Real or else
2795 Ctx_Type := Expr_Type;
2797 -- Any_Fixed is legal in a real context only if a specific fixed-
2798 -- point type is imposed. If Norman Cohen can be confused by this,
2799 -- it deserves a separate message.
2802 and then Expr_Type = Any_Fixed
2804 Error_Msg_N ("illegal context for mixed mode operation", N);
2805 Set_Etype (N, Universal_Real);
2806 Ctx_Type := Universal_Real;
2810 -- A user-defined operator is transformed into a function call at
2811 -- this point, so that further processing knows that operators are
2812 -- really operators (i.e. are predefined operators). User-defined
2813 -- operators that are intrinsic are just renamings of the predefined
2814 -- ones, and need not be turned into calls either, but if they rename
2815 -- a different operator, we must transform the node accordingly.
2816 -- Instantiations of Unchecked_Conversion are intrinsic but are
2817 -- treated as functions, even if given an operator designator.
2819 if Nkind (N) in N_Op
2820 and then Present (Entity (N))
2821 and then Ekind (Entity (N)) /= E_Operator
2823 if not Is_Predefined_Op (Entity (N)) then
2824 Rewrite_Operator_As_Call (N, Entity (N));
2826 elsif Present (Alias (Entity (N)))
2828 Nkind (Parent (Parent (Entity (N)))) =
2829 N_Subprogram_Renaming_Declaration
2831 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2833 -- If the node is rewritten, it will be fully resolved in
2834 -- Rewrite_Renamed_Operator.
2836 if Analyzed (N) then
2842 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)");
2988 -- The expression is definitely NOT overloaded at this point, so
2989 -- we reset the Is_Overloaded flag to avoid any confusion when
2990 -- reanalyzing the node.
2992 Set_Is_Overloaded (N, False);
2994 -- Freeze expression type, entity if it is a name, and designated
2995 -- type if it is an allocator (RM 13.14(10,11,13)).
2997 -- Now that the resolution of the type of the node is complete, and
2998 -- we did not detect an error, we can expand this node. We skip the
2999 -- expand call if we are in a default expression, see section
3000 -- "Handling of Default Expressions" in Sem spec.
3002 Debug_A_Exit ("resolving ", N, " (done)");
3004 -- We unconditionally freeze the expression, even if we are in
3005 -- default expression mode (the Freeze_Expression routine tests this
3006 -- flag and only freezes static types if it is set).
3008 -- Ada 2012 (AI05-177): The declaration of an expression function
3009 -- does not cause freezing, but we never reach here in that case.
3010 -- Here we are resolving the corresponding expanded body, so we do
3011 -- need to perform normal freezing.
3013 Freeze_Expression (N);
3015 -- Now we can do the expansion
3025 -- Version with check(s) suppressed
3027 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3029 if Suppress = All_Checks then
3031 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3033 Scope_Suppress.Suppress := (others => True);
3035 Scope_Suppress.Suppress := Sva;
3040 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3042 Scope_Suppress.Suppress (Suppress) := True;
3044 Scope_Suppress.Suppress (Suppress) := Svg;
3053 -- Version with implicit type
3055 procedure Resolve (N : Node_Id) is
3057 Resolve (N, Etype (N));
3060 ---------------------
3061 -- Resolve_Actuals --
3062 ---------------------
3064 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3065 Loc : constant Source_Ptr := Sloc (N);
3071 Prev : Node_Id := Empty;
3075 Real_Subp : Entity_Id;
3076 -- If the subprogram being called is an inherited operation for
3077 -- a formal derived type in an instance, Real_Subp is the subprogram
3078 -- that will be called. It may have different formal names than the
3079 -- operation of the formal in the generic, so after actual is resolved
3080 -- the name of the actual in a named association must carry the name
3081 -- of the actual of the subprogram being called.
3083 procedure Check_Aliased_Parameter;
3084 -- Check rules on aliased parameters and related accessibility rules
3085 -- in (RM 3.10.2 (10.2-10.4)).
3087 procedure Check_Argument_Order;
3088 -- Performs a check for the case where the actuals are all simple
3089 -- identifiers that correspond to the formal names, but in the wrong
3090 -- order, which is considered suspicious and cause for a warning.
3092 procedure Check_Prefixed_Call;
3093 -- If the original node is an overloaded call in prefix notation,
3094 -- insert an 'Access or a dereference as needed over the first actual.
3095 -- Try_Object_Operation has already verified that there is a valid
3096 -- interpretation, but the form of the actual can only be determined
3097 -- once the primitive operation is identified.
3099 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id);
3100 -- Emit an error concerning the illegal usage of an effectively volatile
3101 -- object in interfering context (SPARK RM 7.13(12)).
3103 procedure Insert_Default;
3104 -- If the actual is missing in a call, insert in the actuals list
3105 -- an instance of the default expression. The insertion is always
3106 -- a named association.
3108 procedure Property_Error
3111 Prop_Nam : Name_Id);
3112 -- Emit an error concerning variable Var with entity Var_Id that has
3113 -- enabled property Prop_Nam when it acts as an actual parameter in a
3114 -- call and the corresponding formal parameter is of mode IN.
3116 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
3117 -- Check whether T1 and T2, or their full views, are derived from a
3118 -- common type. Used to enforce the restrictions on array conversions
3121 function Static_Concatenation (N : Node_Id) return Boolean;
3122 -- Predicate to determine whether an actual that is a concatenation
3123 -- will be evaluated statically and does not need a transient scope.
3124 -- This must be determined before the actual is resolved and expanded
3125 -- because if needed the transient scope must be introduced earlier.
3127 -----------------------------
3128 -- Check_Aliased_Parameter --
3129 -----------------------------
3131 procedure Check_Aliased_Parameter is
3132 Nominal_Subt : Entity_Id;
3135 if Is_Aliased (F) then
3136 if Is_Tagged_Type (A_Typ) then
3139 elsif Is_Aliased_View (A) then
3140 if Is_Constr_Subt_For_U_Nominal (A_Typ) then
3141 Nominal_Subt := Base_Type (A_Typ);
3143 Nominal_Subt := A_Typ;
3146 if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
3149 -- In a generic body assume the worst for generic formals:
3150 -- they can have a constrained partial view (AI05-041).
3152 elsif Has_Discriminants (F_Typ)
3153 and then not Is_Constrained (F_Typ)
3154 and then not Has_Constrained_Partial_View (F_Typ)
3155 and then not Is_Generic_Type (F_Typ)
3160 Error_Msg_NE ("untagged actual does not match "
3161 & "aliased formal&", A, F);
3165 Error_Msg_NE ("actual for aliased formal& must be "
3166 & "aliased object", A, F);
3169 if Ekind (Nam) = E_Procedure then
3172 elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
3173 if Nkind (Parent (N)) = N_Type_Conversion
3174 and then Type_Access_Level (Etype (Parent (N))) <
3175 Object_Access_Level (A)
3177 Error_Msg_N ("aliased actual has wrong accessibility", A);
3180 elsif Nkind (Parent (N)) = N_Qualified_Expression
3181 and then Nkind (Parent (Parent (N))) = N_Allocator
3182 and then Type_Access_Level (Etype (Parent (Parent (N)))) <
3183 Object_Access_Level (A)
3186 ("aliased actual in allocator has wrong accessibility", A);
3189 end Check_Aliased_Parameter;
3191 --------------------------
3192 -- Check_Argument_Order --
3193 --------------------------
3195 procedure Check_Argument_Order is
3197 -- Nothing to do if no parameters, or original node is neither a
3198 -- function call nor a procedure call statement (happens in the
3199 -- operator-transformed-to-function call case), or the call does
3200 -- not come from source, or this warning is off.
3202 if not Warn_On_Parameter_Order
3203 or else No (Parameter_Associations (N))
3204 or else Nkind (Original_Node (N)) not in N_Subprogram_Call
3205 or else not Comes_From_Source (N)
3211 Nargs : constant Nat := List_Length (Parameter_Associations (N));
3214 -- Nothing to do if only one parameter
3220 -- Here if at least two arguments
3223 Actuals : array (1 .. Nargs) of Node_Id;
3227 Wrong_Order : Boolean := False;
3228 -- Set True if an out of order case is found
3231 -- Collect identifier names of actuals, fail if any actual is
3232 -- not a simple identifier, and record max length of name.
3234 Actual := First (Parameter_Associations (N));
3235 for J in Actuals'Range loop
3236 if Nkind (Actual) /= N_Identifier then
3239 Actuals (J) := Actual;
3244 -- If we got this far, all actuals are identifiers and the list
3245 -- of their names is stored in the Actuals array.
3247 Formal := First_Formal (Nam);
3248 for J in Actuals'Range loop
3250 -- If we ran out of formals, that's odd, probably an error
3251 -- which will be detected elsewhere, but abandon the search.
3257 -- If name matches and is in order OK
3259 if Chars (Formal) = Chars (Actuals (J)) then
3263 -- If no match, see if it is elsewhere in list and if so
3264 -- flag potential wrong order if type is compatible.
3266 for K in Actuals'Range loop
3267 if Chars (Formal) = Chars (Actuals (K))
3269 Has_Compatible_Type (Actuals (K), Etype (Formal))
3271 Wrong_Order := True;
3281 <<Continue>> Next_Formal (Formal);
3284 -- If Formals left over, also probably an error, skip warning
3286 if Present (Formal) then
3290 -- Here we give the warning if something was out of order
3294 ("?P?actuals for this call may be in wrong order", N);
3298 end Check_Argument_Order;
3300 -------------------------
3301 -- Check_Prefixed_Call --
3302 -------------------------
3304 procedure Check_Prefixed_Call is
3305 Act : constant Node_Id := First_Actual (N);
3306 A_Type : constant Entity_Id := Etype (Act);
3307 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
3308 Orig : constant Node_Id := Original_Node (N);
3312 -- Check whether the call is a prefixed call, with or without
3313 -- additional actuals.
3315 if Nkind (Orig) = N_Selected_Component
3317 (Nkind (Orig) = N_Indexed_Component
3318 and then Nkind (Prefix (Orig)) = N_Selected_Component
3319 and then Is_Entity_Name (Prefix (Prefix (Orig)))
3320 and then Is_Entity_Name (Act)
3321 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3323 if Is_Access_Type (A_Type)
3324 and then not Is_Access_Type (F_Type)
3326 -- Introduce dereference on object in prefix
3329 Make_Explicit_Dereference (Sloc (Act),
3330 Prefix => Relocate_Node (Act));
3331 Rewrite (Act, New_A);
3334 elsif Is_Access_Type (F_Type)
3335 and then not Is_Access_Type (A_Type)
3337 -- Introduce an implicit 'Access in prefix
3339 if not Is_Aliased_View (Act) then
3341 ("object in prefixed call to& must be aliased "
3342 & "(RM 4.1.3 (13 1/2))",
3347 Make_Attribute_Reference (Loc,
3348 Attribute_Name => Name_Access,
3349 Prefix => Relocate_Node (Act)));
3354 end Check_Prefixed_Call;
3356 ---------------------------------------
3357 -- Flag_Effectively_Volatile_Objects --
3358 ---------------------------------------
3360 procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id) is
3361 function Flag_Object (N : Node_Id) return Traverse_Result;
3362 -- Determine whether arbitrary node N denotes an effectively volatile
3363 -- object and if it does, emit an error.
3369 function Flag_Object (N : Node_Id) return Traverse_Result is
3373 -- Do not consider nested function calls because they have already
3374 -- been processed during their own resolution.
3376 if Nkind (N) = N_Function_Call then
3379 elsif Is_Entity_Name (N) and then Present (Entity (N)) then
3383 and then Is_Effectively_Volatile (Id)
3384 and then (Async_Writers_Enabled (Id)
3385 or else Effective_Reads_Enabled (Id))
3388 ("volatile object cannot appear in this context (SPARK "
3389 & "RM 7.1.3(11))", N);
3397 procedure Flag_Objects is new Traverse_Proc (Flag_Object);
3399 -- Start of processing for Flag_Effectively_Volatile_Objects
3402 Flag_Objects (Expr);
3403 end Flag_Effectively_Volatile_Objects;
3405 --------------------
3406 -- Insert_Default --
3407 --------------------
3409 procedure Insert_Default is
3414 -- Missing argument in call, nothing to insert
3416 if No (Default_Value (F)) then
3420 -- Note that we do a full New_Copy_Tree, so that any associated
3421 -- Itypes are properly copied. This may not be needed any more,
3422 -- but it does no harm as a safety measure. Defaults of a generic
3423 -- formal may be out of bounds of the corresponding actual (see
3424 -- cc1311b) and an additional check may be required.
3429 New_Scope => Current_Scope,
3432 -- Propagate dimension information, if any.
3434 Copy_Dimensions (Default_Value (F), Actval);
3436 if Is_Concurrent_Type (Scope (Nam))
3437 and then Has_Discriminants (Scope (Nam))
3439 Replace_Actual_Discriminants (N, Actval);
3442 if Is_Overloadable (Nam)
3443 and then Present (Alias (Nam))
3445 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3446 and then not Is_Tagged_Type (Etype (F))
3448 -- If default is a real literal, do not introduce a
3449 -- conversion whose effect may depend on the run-time
3450 -- size of universal real.
3452 if Nkind (Actval) = N_Real_Literal then
3453 Set_Etype (Actval, Base_Type (Etype (F)));
3455 Actval := Unchecked_Convert_To (Etype (F), Actval);
3459 if Is_Scalar_Type (Etype (F)) then
3460 Enable_Range_Check (Actval);
3463 Set_Parent (Actval, N);
3465 -- Resolve aggregates with their base type, to avoid scope
3466 -- anomalies: the subtype was first built in the subprogram
3467 -- declaration, and the current call may be nested.
3469 if Nkind (Actval) = N_Aggregate then
3470 Analyze_And_Resolve (Actval, Etype (F));
3472 Analyze_And_Resolve (Actval, Etype (Actval));
3476 Set_Parent (Actval, N);
3478 -- See note above concerning aggregates
3480 if Nkind (Actval) = N_Aggregate
3481 and then Has_Discriminants (Etype (Actval))
3483 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3485 -- Resolve entities with their own type, which may differ from
3486 -- the type of a reference in a generic context (the view
3487 -- swapping mechanism did not anticipate the re-analysis of
3488 -- default values in calls).
3490 elsif Is_Entity_Name (Actval) then
3491 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3494 Analyze_And_Resolve (Actval, Etype (Actval));
3498 -- If default is a tag indeterminate function call, propagate tag
3499 -- to obtain proper dispatching.
3501 if Is_Controlling_Formal (F)
3502 and then Nkind (Default_Value (F)) = N_Function_Call
3504 Set_Is_Controlling_Actual (Actval);
3508 -- If the default expression raises constraint error, then just
3509 -- silently replace it with an N_Raise_Constraint_Error node, since
3510 -- we already gave the warning on the subprogram spec. If node is
3511 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3512 -- the warnings removal machinery.
3514 if Raises_Constraint_Error (Actval)
3515 and then Nkind (Actval) /= N_Raise_Constraint_Error
3518 Make_Raise_Constraint_Error (Loc,
3519 Reason => CE_Range_Check_Failed));
3520 Set_Raises_Constraint_Error (Actval);
3521 Set_Etype (Actval, Etype (F));
3525 Make_Parameter_Association (Loc,
3526 Explicit_Actual_Parameter => Actval,
3527 Selector_Name => Make_Identifier (Loc, Chars (F)));
3529 -- Case of insertion is first named actual
3531 if No (Prev) or else
3532 Nkind (Parent (Prev)) /= N_Parameter_Association
3534 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3535 Set_First_Named_Actual (N, Actval);
3538 if No (Parameter_Associations (N)) then
3539 Set_Parameter_Associations (N, New_List (Assoc));
3541 Append (Assoc, Parameter_Associations (N));
3545 Insert_After (Prev, Assoc);
3548 -- Case of insertion is not first named actual
3551 Set_Next_Named_Actual
3552 (Assoc, Next_Named_Actual (Parent (Prev)));
3553 Set_Next_Named_Actual (Parent (Prev), Actval);
3554 Append (Assoc, Parameter_Associations (N));
3557 Mark_Rewrite_Insertion (Assoc);
3558 Mark_Rewrite_Insertion (Actval);
3563 --------------------
3564 -- Property_Error --
3565 --------------------
3567 procedure Property_Error
3573 Error_Msg_Name_1 := Prop_Nam;
3575 ("external variable & with enabled property % cannot appear as "
3576 & "actual in procedure call (SPARK RM 7.1.3(10))", Var, Var_Id);
3577 Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
3584 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3585 FT1 : Entity_Id := T1;
3586 FT2 : Entity_Id := T2;
3589 if Is_Private_Type (T1)
3590 and then Present (Full_View (T1))
3592 FT1 := Full_View (T1);
3595 if Is_Private_Type (T2)
3596 and then Present (Full_View (T2))
3598 FT2 := Full_View (T2);
3601 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3604 --------------------------
3605 -- Static_Concatenation --
3606 --------------------------
3608 function Static_Concatenation (N : Node_Id) return Boolean is
3611 when N_String_Literal =>
3616 -- Concatenation is static when both operands are static and
3617 -- the concatenation operator is a predefined one.
3619 return Scope (Entity (N)) = Standard_Standard
3621 Static_Concatenation (Left_Opnd (N))
3623 Static_Concatenation (Right_Opnd (N));
3626 if Is_Entity_Name (N) then
3628 Ent : constant Entity_Id := Entity (N);
3630 return Ekind (Ent) = E_Constant
3631 and then Present (Constant_Value (Ent))
3633 Is_OK_Static_Expression (Constant_Value (Ent));
3640 end Static_Concatenation;
3642 -- Start of processing for Resolve_Actuals
3645 Check_Argument_Order;
3647 if Is_Overloadable (Nam)
3648 and then Is_Inherited_Operation (Nam)
3649 and then In_Instance
3650 and then Present (Alias (Nam))
3651 and then Present (Overridden_Operation (Alias (Nam)))
3653 Real_Subp := Alias (Nam);
3658 if Present (First_Actual (N)) then
3659 Check_Prefixed_Call;
3662 A := First_Actual (N);
3663 F := First_Formal (Nam);
3665 if Present (Real_Subp) then
3666 Real_F := First_Formal (Real_Subp);
3669 while Present (F) loop
3670 if No (A) and then Needs_No_Actuals (Nam) then
3673 -- If we have an error in any actual or formal, indicated by a type
3674 -- of Any_Type, then abandon resolution attempt, and set result type
3675 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3676 -- type is imposed from context.
3678 elsif (Present (A) and then Etype (A) = Any_Type)
3679 or else Etype (F) = Any_Type
3681 if Nkind (A) /= N_Raise_Expression then
3682 Set_Etype (N, Any_Type);
3687 -- Case where actual is present
3689 -- If the actual is an entity, generate a reference to it now. We
3690 -- do this before the actual is resolved, because a formal of some
3691 -- protected subprogram, or a task discriminant, will be rewritten
3692 -- during expansion, and the source entity reference may be lost.
3695 and then Is_Entity_Name (A)
3696 and then Comes_From_Source (A)
3698 Orig_A := Entity (A);
3700 if Present (Orig_A) then
3701 if Is_Formal (Orig_A)
3702 and then Ekind (F) /= E_In_Parameter
3704 Generate_Reference (Orig_A, A, 'm');
3706 elsif not Is_Overloaded (A) then
3707 if Ekind (F) /= E_Out_Parameter then
3708 Generate_Reference (Orig_A, A);
3710 -- RM 6.4.1(12): For an out parameter that is passed by
3711 -- copy, the formal parameter object is created, and:
3713 -- * For an access type, the formal parameter is initialized
3714 -- from the value of the actual, without checking that the
3715 -- value satisfies any constraint, any predicate, or any
3716 -- exclusion of the null value.
3718 -- * For a scalar type that has the Default_Value aspect
3719 -- specified, the formal parameter is initialized from the
3720 -- value of the actual, without checking that the value
3721 -- satisfies any constraint or any predicate.
3722 -- I do not understand why this case is included??? this is
3723 -- not a case where an OUT parameter is treated as IN OUT.
3725 -- * For a composite type with discriminants or that has
3726 -- implicit initial values for any subcomponents, the
3727 -- behavior is as for an in out parameter passed by copy.
3729 -- Hence for these cases we generate the read reference now
3730 -- (the write reference will be generated later by
3731 -- Note_Possible_Modification).
3733 elsif Is_By_Copy_Type (Etype (F))
3735 (Is_Access_Type (Etype (F))
3737 (Is_Scalar_Type (Etype (F))
3739 Present (Default_Aspect_Value (Etype (F))))
3741 (Is_Composite_Type (Etype (F))
3742 and then (Has_Discriminants (Etype (F))
3743 or else Is_Partially_Initialized_Type
3746 Generate_Reference (Orig_A, A);
3753 and then (Nkind (Parent (A)) /= N_Parameter_Association
3754 or else Chars (Selector_Name (Parent (A))) = Chars (F))
3756 -- If style checking mode on, check match of formal name
3759 if Nkind (Parent (A)) = N_Parameter_Association then
3760 Check_Identifier (Selector_Name (Parent (A)), F);
3764 -- If the formal is Out or In_Out, do not resolve and expand the
3765 -- conversion, because it is subsequently expanded into explicit
3766 -- temporaries and assignments. However, the object of the
3767 -- conversion can be resolved. An exception is the case of tagged
3768 -- type conversion with a class-wide actual. In that case we want
3769 -- the tag check to occur and no temporary will be needed (no
3770 -- representation change can occur) and the parameter is passed by
3771 -- reference, so we go ahead and resolve the type conversion.
3772 -- Another exception is the case of reference to component or
3773 -- subcomponent of a bit-packed array, in which case we want to
3774 -- defer expansion to the point the in and out assignments are
3777 if Ekind (F) /= E_In_Parameter
3778 and then Nkind (A) = N_Type_Conversion
3779 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3781 if Ekind (F) = E_In_Out_Parameter
3782 and then Is_Array_Type (Etype (F))
3784 -- In a view conversion, the conversion must be legal in
3785 -- both directions, and thus both component types must be
3786 -- aliased, or neither (4.6 (8)).
3788 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3789 -- the privacy requirement should not apply to generic
3790 -- types, and should be checked in an instance. ARG query
3793 if Has_Aliased_Components (Etype (Expression (A))) /=
3794 Has_Aliased_Components (Etype (F))
3797 ("both component types in a view conversion must be"
3798 & " aliased, or neither", A);
3800 -- Comment here??? what set of cases???
3803 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3805 -- Check view conv between unrelated by ref array types
3807 if Is_By_Reference_Type (Etype (F))
3808 or else Is_By_Reference_Type (Etype (Expression (A)))
3811 ("view conversion between unrelated by reference "
3812 & "array types not allowed (\'A'I-00246)", A);
3814 -- In Ada 2005 mode, check view conversion component
3815 -- type cannot be private, tagged, or volatile. Note
3816 -- that we only apply this to source conversions. The
3817 -- generated code can contain conversions which are
3818 -- not subject to this test, and we cannot extract the
3819 -- component type in such cases since it is not present.
3821 elsif Comes_From_Source (A)
3822 and then Ada_Version >= Ada_2005
3825 Comp_Type : constant Entity_Id :=
3827 (Etype (Expression (A)));
3829 if (Is_Private_Type (Comp_Type)
3830 and then not Is_Generic_Type (Comp_Type))
3831 or else Is_Tagged_Type (Comp_Type)
3832 or else Is_Volatile (Comp_Type)
3835 ("component type of a view conversion cannot"
3836 & " be private, tagged, or volatile"
3845 -- Resolve expression if conversion is all OK
3847 if (Conversion_OK (A)
3848 or else Valid_Conversion (A, Etype (A), Expression (A)))
3849 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3851 Resolve (Expression (A));
3854 -- If the actual is a function call that returns a limited
3855 -- unconstrained object that needs finalization, create a
3856 -- transient scope for it, so that it can receive the proper
3857 -- finalization list.
3859 elsif Nkind (A) = N_Function_Call
3860 and then Is_Limited_Record (Etype (F))
3861 and then not Is_Constrained (Etype (F))
3862 and then Expander_Active
3863 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3865 Establish_Transient_Scope (A, Sec_Stack => False);
3866 Resolve (A, Etype (F));
3868 -- A small optimization: if one of the actuals is a concatenation
3869 -- create a block around a procedure call to recover stack space.
3870 -- This alleviates stack usage when several procedure calls in
3871 -- the same statement list use concatenation. We do not perform
3872 -- this wrapping for code statements, where the argument is a
3873 -- static string, and we want to preserve warnings involving
3874 -- sequences of such statements.
3876 elsif Nkind (A) = N_Op_Concat
3877 and then Nkind (N) = N_Procedure_Call_Statement
3878 and then Expander_Active
3880 not (Is_Intrinsic_Subprogram (Nam)
3881 and then Chars (Nam) = Name_Asm)
3882 and then not Static_Concatenation (A)
3884 Establish_Transient_Scope (A, Sec_Stack => False);
3885 Resolve (A, Etype (F));
3888 if Nkind (A) = N_Type_Conversion
3889 and then Is_Array_Type (Etype (F))
3890 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3892 (Is_Limited_Type (Etype (F))
3893 or else Is_Limited_Type (Etype (Expression (A))))
3896 ("conversion between unrelated limited array types "
3897 & "not allowed ('A'I-00246)", A);
3899 if Is_Limited_Type (Etype (F)) then
3900 Explain_Limited_Type (Etype (F), A);
3903 if Is_Limited_Type (Etype (Expression (A))) then
3904 Explain_Limited_Type (Etype (Expression (A)), A);
3908 -- (Ada 2005: AI-251): If the actual is an allocator whose
3909 -- directly designated type is a class-wide interface, we build
3910 -- an anonymous access type to use it as the type of the
3911 -- allocator. Later, when the subprogram call is expanded, if
3912 -- the interface has a secondary dispatch table the expander
3913 -- will add a type conversion to force the correct displacement
3916 if Nkind (A) = N_Allocator then
3918 DDT : constant Entity_Id :=
3919 Directly_Designated_Type (Base_Type (Etype (F)));
3921 New_Itype : Entity_Id;
3924 if Is_Class_Wide_Type (DDT)
3925 and then Is_Interface (DDT)
3927 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3928 Set_Etype (New_Itype, Etype (A));
3929 Set_Directly_Designated_Type
3930 (New_Itype, Directly_Designated_Type (Etype (A)));
3931 Set_Etype (A, New_Itype);
3934 -- Ada 2005, AI-162:If the actual is an allocator, the
3935 -- innermost enclosing statement is the master of the
3936 -- created object. This needs to be done with expansion
3937 -- enabled only, otherwise the transient scope will not
3938 -- be removed in the expansion of the wrapped construct.
3940 if (Is_Controlled (DDT) or else Has_Task (DDT))
3941 and then Expander_Active
3943 Establish_Transient_Scope (A, Sec_Stack => False);
3947 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3948 Check_Restriction (No_Access_Parameter_Allocators, A);
3952 -- (Ada 2005): The call may be to a primitive operation of a
3953 -- tagged synchronized type, declared outside of the type. In
3954 -- this case the controlling actual must be converted to its
3955 -- corresponding record type, which is the formal type. The
3956 -- actual may be a subtype, either because of a constraint or
3957 -- because it is a generic actual, so use base type to locate
3960 F_Typ := Base_Type (Etype (F));
3962 if Is_Tagged_Type (F_Typ)
3963 and then (Is_Concurrent_Type (F_Typ)
3964 or else Is_Concurrent_Record_Type (F_Typ))
3966 -- If the actual is overloaded, look for an interpretation
3967 -- that has a synchronized type.
3969 if not Is_Overloaded (A) then
3970 A_Typ := Base_Type (Etype (A));
3974 Index : Interp_Index;
3978 Get_First_Interp (A, Index, It);
3979 while Present (It.Typ) loop
3980 if Is_Concurrent_Type (It.Typ)
3981 or else Is_Concurrent_Record_Type (It.Typ)
3983 A_Typ := Base_Type (It.Typ);
3987 Get_Next_Interp (Index, It);
3993 Full_A_Typ : Entity_Id;
3996 if Present (Full_View (A_Typ)) then
3997 Full_A_Typ := Base_Type (Full_View (A_Typ));
3999 Full_A_Typ := A_Typ;
4002 -- Tagged synchronized type (case 1): the actual is a
4005 if Is_Concurrent_Type (A_Typ)
4006 and then Corresponding_Record_Type (A_Typ) = F_Typ
4009 Unchecked_Convert_To
4010 (Corresponding_Record_Type (A_Typ), A));
4011 Resolve (A, Etype (F));
4013 -- Tagged synchronized type (case 2): the formal is a
4016 elsif Ekind (Full_A_Typ) = E_Record_Type
4018 (Corresponding_Concurrent_Type (Full_A_Typ))
4019 and then Is_Concurrent_Type (F_Typ)
4020 and then Present (Corresponding_Record_Type (F_Typ))
4021 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
4023 Resolve (A, Corresponding_Record_Type (F_Typ));
4028 Resolve (A, Etype (F));
4032 -- Not a synchronized operation
4035 Resolve (A, Etype (F));
4042 -- An actual cannot be an untagged formal incomplete type
4044 if Ekind (A_Typ) = E_Incomplete_Type
4045 and then not Is_Tagged_Type (A_Typ)
4046 and then Is_Generic_Type (A_Typ)
4049 ("invalid use of untagged formal incomplete type", A);
4052 if Comes_From_Source (Original_Node (N))
4053 and then Nkind_In (Original_Node (N), N_Function_Call,
4054 N_Procedure_Call_Statement)
4056 -- In formal mode, check that actual parameters matching
4057 -- formals of tagged types are objects (or ancestor type
4058 -- conversions of objects), not general expressions.
4060 if Is_Actual_Tagged_Parameter (A) then
4061 if Is_SPARK_05_Object_Reference (A) then
4064 elsif Nkind (A) = N_Type_Conversion then
4066 Operand : constant Node_Id := Expression (A);
4067 Operand_Typ : constant Entity_Id := Etype (Operand);
4068 Target_Typ : constant Entity_Id := A_Typ;
4071 if not Is_SPARK_05_Object_Reference (Operand) then
4072 Check_SPARK_05_Restriction
4073 ("object required", Operand);
4075 -- In formal mode, the only view conversions are those
4076 -- involving ancestor conversion of an extended type.
4079 (Is_Tagged_Type (Target_Typ)
4080 and then not Is_Class_Wide_Type (Target_Typ)
4081 and then Is_Tagged_Type (Operand_Typ)
4082 and then not Is_Class_Wide_Type (Operand_Typ)
4083 and then Is_Ancestor (Target_Typ, Operand_Typ))
4086 (F, E_Out_Parameter, E_In_Out_Parameter)
4088 Check_SPARK_05_Restriction
4089 ("ancestor conversion is the only permitted "
4090 & "view conversion", A);
4092 Check_SPARK_05_Restriction
4093 ("ancestor conversion required", A);
4102 Check_SPARK_05_Restriction ("object required", A);
4105 -- In formal mode, the only view conversions are those
4106 -- involving ancestor conversion of an extended type.
4108 elsif Nkind (A) = N_Type_Conversion
4109 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
4111 Check_SPARK_05_Restriction
4112 ("ancestor conversion is the only permitted view "
4117 -- has warnings suppressed, then we reset Never_Set_In_Source for
4118 -- the calling entity. The reason for this is to catch cases like
4119 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4120 -- uses trickery to modify an IN parameter.
4122 if Ekind (F) = E_In_Parameter
4123 and then Is_Entity_Name (A)
4124 and then Present (Entity (A))
4125 and then Ekind (Entity (A)) = E_Variable
4126 and then Has_Warnings_Off (F_Typ)
4128 Set_Never_Set_In_Source (Entity (A), False);
4131 -- Perform error checks for IN and IN OUT parameters
4133 if Ekind (F) /= E_Out_Parameter then
4135 -- Check unset reference. For scalar parameters, it is clearly
4136 -- wrong to pass an uninitialized value as either an IN or
4137 -- IN-OUT parameter. For composites, it is also clearly an
4138 -- error to pass a completely uninitialized value as an IN
4139 -- parameter, but the case of IN OUT is trickier. We prefer
4140 -- not to give a warning here. For example, suppose there is
4141 -- a routine that sets some component of a record to False.
4142 -- It is perfectly reasonable to make this IN-OUT and allow
4143 -- either initialized or uninitialized records to be passed
4146 -- For partially initialized composite values, we also avoid
4147 -- warnings, since it is quite likely that we are passing a
4148 -- partially initialized value and only the initialized fields
4149 -- will in fact be read in the subprogram.
4151 if Is_Scalar_Type (A_Typ)
4152 or else (Ekind (F) = E_In_Parameter
4153 and then not Is_Partially_Initialized_Type (A_Typ))
4155 Check_Unset_Reference (A);
4158 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4159 -- actual to a nested call, since this constitutes a reading of
4160 -- the parameter, which is not allowed.
4162 if Ada_Version = Ada_83
4163 and then Is_Entity_Name (A)
4164 and then Ekind (Entity (A)) = E_Out_Parameter
4166 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
4170 -- Case of OUT or IN OUT parameter
4172 if Ekind (F) /= E_In_Parameter then
4174 -- For an Out parameter, check for useless assignment. Note
4175 -- that we can't set Last_Assignment this early, because we may
4176 -- kill current values in Resolve_Call, and that call would
4177 -- clobber the Last_Assignment field.
4179 -- Note: call Warn_On_Useless_Assignment before doing the check
4180 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4181 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4182 -- reflects the last assignment, not this one.
4184 if Ekind (F) = E_Out_Parameter then
4185 if Warn_On_Modified_As_Out_Parameter (F)
4186 and then Is_Entity_Name (A)
4187 and then Present (Entity (A))
4188 and then Comes_From_Source (N)
4190 Warn_On_Useless_Assignment (Entity (A), A);
4194 -- Validate the form of the actual. Note that the call to
4195 -- Is_OK_Variable_For_Out_Formal generates the required
4196 -- reference in this case.
4198 -- A call to an initialization procedure for an aggregate
4199 -- component may initialize a nested component of a constant
4200 -- designated object. In this context the object is variable.
4202 if not Is_OK_Variable_For_Out_Formal (A)
4203 and then not Is_Init_Proc (Nam)
4205 Error_Msg_NE ("actual for& must be a variable", A, F);
4207 if Is_Subprogram (Current_Scope) then
4208 if Is_Invariant_Procedure (Current_Scope)
4209 or else Is_Partial_Invariant_Procedure (Current_Scope)
4212 ("function used in invariant cannot modify its "
4215 elsif Is_Predicate_Function (Current_Scope) then
4217 ("function used in predicate cannot modify its "
4223 -- What's the following about???
4225 if Is_Entity_Name (A) then
4226 Kill_Checks (Entity (A));
4232 if Etype (A) = Any_Type then
4233 Set_Etype (N, Any_Type);
4237 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4239 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
4241 -- Apply predicate tests except in certain special cases. Note
4242 -- that it might be more consistent to apply these only when
4243 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4244 -- for the outbound predicate tests ??? In any case indicate
4245 -- the function being called, for better warnings if the call
4246 -- leads to an infinite recursion.
4248 if Predicate_Tests_On_Arguments (Nam) then
4249 Apply_Predicate_Check (A, F_Typ, Nam);
4252 -- Apply required constraint checks
4254 -- Gigi looks at the check flag and uses the appropriate types.
4255 -- For now since one flag is used there is an optimization
4256 -- which might not be done in the IN OUT case since Gigi does
4257 -- not do any analysis. More thought required about this ???
4259 -- In fact is this comment obsolete??? doesn't the expander now
4260 -- generate all these tests anyway???
4262 if Is_Scalar_Type (Etype (A)) then
4263 Apply_Scalar_Range_Check (A, F_Typ);
4265 elsif Is_Array_Type (Etype (A)) then
4266 Apply_Length_Check (A, F_Typ);
4268 elsif Is_Record_Type (F_Typ)
4269 and then Has_Discriminants (F_Typ)
4270 and then Is_Constrained (F_Typ)
4271 and then (not Is_Derived_Type (F_Typ)
4272 or else Comes_From_Source (Nam))
4274 Apply_Discriminant_Check (A, F_Typ);
4276 -- For view conversions of a discriminated object, apply
4277 -- check to object itself, the conversion alreay has the
4280 if Nkind (A) = N_Type_Conversion
4281 and then Is_Constrained (Etype (Expression (A)))
4283 Apply_Discriminant_Check (Expression (A), F_Typ);
4286 elsif Is_Access_Type (F_Typ)
4287 and then Is_Array_Type (Designated_Type (F_Typ))
4288 and then Is_Constrained (Designated_Type (F_Typ))
4290 Apply_Length_Check (A, F_Typ);
4292 elsif Is_Access_Type (F_Typ)
4293 and then Has_Discriminants (Designated_Type (F_Typ))
4294 and then Is_Constrained (Designated_Type (F_Typ))
4296 Apply_Discriminant_Check (A, F_Typ);
4299 Apply_Range_Check (A, F_Typ);
4302 -- Ada 2005 (AI-231): Note that the controlling parameter case
4303 -- already existed in Ada 95, which is partially checked
4304 -- elsewhere (see Checks), and we don't want the warning
4305 -- message to differ.
4307 if Is_Access_Type (F_Typ)
4308 and then Can_Never_Be_Null (F_Typ)
4309 and then Known_Null (A)
4311 if Is_Controlling_Formal (F) then
4312 Apply_Compile_Time_Constraint_Error
4314 Msg => "null value not allowed here??",
4315 Reason => CE_Access_Check_Failed);
4317 elsif Ada_Version >= Ada_2005 then
4318 Apply_Compile_Time_Constraint_Error
4320 Msg => "(Ada 2005) null not allowed in "
4321 & "null-excluding formal??",
4322 Reason => CE_Null_Not_Allowed);
4327 -- Checks for OUT parameters and IN OUT parameters
4329 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
4331 -- If there is a type conversion, to make sure the return value
4332 -- meets the constraints of the variable before the conversion.
4334 if Nkind (A) = N_Type_Conversion then
4335 if Is_Scalar_Type (A_Typ) then
4336 Apply_Scalar_Range_Check
4337 (Expression (A), Etype (Expression (A)), A_Typ);
4340 (Expression (A), Etype (Expression (A)), A_Typ);
4343 -- If no conversion apply scalar range checks and length checks
4344 -- base on the subtype of the actual (NOT that of the formal).
4347 if Is_Scalar_Type (F_Typ) then
4348 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
4349 elsif Is_Array_Type (F_Typ)
4350 and then Ekind (F) = E_Out_Parameter
4352 Apply_Length_Check (A, F_Typ);
4354 Apply_Range_Check (A, A_Typ, F_Typ);
4358 -- Note: we do not apply the predicate checks for the case of
4359 -- OUT and IN OUT parameters. They are instead applied in the
4360 -- Expand_Actuals routine in Exp_Ch6.
4363 -- An actual associated with an access parameter is implicitly
4364 -- converted to the anonymous access type of the formal and must
4365 -- satisfy the legality checks for access conversions.
4367 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4368 if not Valid_Conversion (A, F_Typ, A) then
4370 ("invalid implicit conversion for access parameter", A);
4373 -- If the actual is an access selected component of a variable,
4374 -- the call may modify its designated object. It is reasonable
4375 -- to treat this as a potential modification of the enclosing
4376 -- record, to prevent spurious warnings that it should be
4377 -- declared as a constant, because intuitively programmers
4378 -- regard the designated subcomponent as part of the record.
4380 if Nkind (A) = N_Selected_Component
4381 and then Is_Entity_Name (Prefix (A))
4382 and then not Is_Constant_Object (Entity (Prefix (A)))
4384 Note_Possible_Modification (A, Sure => False);
4388 -- Check bad case of atomic/volatile argument (RM C.6(12))
4390 if Is_By_Reference_Type (Etype (F))
4391 and then Comes_From_Source (N)
4393 if Is_Atomic_Object (A)
4394 and then not Is_Atomic (Etype (F))
4397 ("cannot pass atomic argument to non-atomic formal&",
4400 elsif Is_Volatile_Object (A)
4401 and then not Is_Volatile (Etype (F))
4404 ("cannot pass volatile argument to non-volatile formal&",
4409 -- Check that subprograms don't have improper controlling
4410 -- arguments (RM 3.9.2 (9)).
4412 -- A primitive operation may have an access parameter of an
4413 -- incomplete tagged type, but a dispatching call is illegal
4414 -- if the type is still incomplete.
4416 if Is_Controlling_Formal (F) then
4417 Set_Is_Controlling_Actual (A);
4419 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
4421 Desig : constant Entity_Id := Designated_Type (Etype (F));
4423 if Ekind (Desig) = E_Incomplete_Type
4424 and then No (Full_View (Desig))
4425 and then No (Non_Limited_View (Desig))
4428 ("premature use of incomplete type& "
4429 & "in dispatching call", A, Desig);
4434 elsif Nkind (A) = N_Explicit_Dereference then
4435 Validate_Remote_Access_To_Class_Wide_Type (A);
4438 -- Apply legality rule 3.9.2 (9/1)
4440 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
4441 and then not Is_Class_Wide_Type (F_Typ)
4442 and then not Is_Controlling_Formal (F)
4443 and then not In_Instance
4445 Error_Msg_N ("class-wide argument not allowed here!", A);
4447 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4448 Error_Msg_Node_2 := F_Typ;
4450 ("& is not a dispatching operation of &!", A, Nam);
4453 -- Apply the checks described in 3.10.2(27): if the context is a
4454 -- specific access-to-object, the actual cannot be class-wide.
4455 -- Use base type to exclude access_to_subprogram cases.
4457 elsif Is_Access_Type (A_Typ)
4458 and then Is_Access_Type (F_Typ)
4459 and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
4460 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
4461 or else (Nkind (A) = N_Attribute_Reference
4463 Is_Class_Wide_Type (Etype (Prefix (A)))))
4464 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
4465 and then not Is_Controlling_Formal (F)
4467 -- Disable these checks for call to imported C++ subprograms
4470 (Is_Entity_Name (Name (N))
4471 and then Is_Imported (Entity (Name (N)))
4472 and then Convention (Entity (Name (N))) = Convention_CPP)
4475 ("access to class-wide argument not allowed here!", A);
4477 if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
4478 Error_Msg_Node_2 := Designated_Type (F_Typ);
4480 ("& is not a dispatching operation of &!", A, Nam);
4484 Check_Aliased_Parameter;
4488 -- If it is a named association, treat the selector_name as a
4489 -- proper identifier, and mark the corresponding entity.
4491 if Nkind (Parent (A)) = N_Parameter_Association
4493 -- Ignore reference in SPARK mode, as it refers to an entity not
4494 -- in scope at the point of reference, so the reference should
4495 -- be ignored for computing effects of subprograms.
4497 and then not GNATprove_Mode
4499 -- If subprogram is overridden, use name of formal that
4502 if Present (Real_Subp) then
4503 Set_Entity (Selector_Name (Parent (A)), Real_F);
4504 Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
4507 Set_Entity (Selector_Name (Parent (A)), F);
4508 Generate_Reference (F, Selector_Name (Parent (A)));
4509 Set_Etype (Selector_Name (Parent (A)), F_Typ);
4510 Generate_Reference (F_Typ, N, ' ');
4516 if Ekind (F) /= E_Out_Parameter then
4517 Check_Unset_Reference (A);
4520 -- The following checks are only relevant when SPARK_Mode is on as
4521 -- they are not standard Ada legality rule. Internally generated
4522 -- temporaries are ignored.
4524 if SPARK_Mode = On and then Comes_From_Source (A) then
4526 -- An effectively volatile object may act as an actual when the
4527 -- corresponding formal is of a non-scalar effectively volatile
4528 -- type (SPARK RM 7.1.3(11)).
4530 if not Is_Scalar_Type (Etype (F))
4531 and then Is_Effectively_Volatile (Etype (F))
4535 -- An effectively volatile object may act as an actual in a
4536 -- call to an instance of Unchecked_Conversion.
4537 -- (SPARK RM 7.1.3(11)).
4539 elsif Is_Unchecked_Conversion_Instance (Nam) then
4542 -- The actual denotes an object
4544 elsif Is_Effectively_Volatile_Object (A) then
4546 ("volatile object cannot act as actual in a call (SPARK "
4547 & "RM 7.1.3(11))", A);
4549 -- Otherwise the actual denotes an expression. Inspect the
4550 -- expression and flag each effectively volatile object with
4551 -- enabled property Async_Writers or Effective_Reads as illegal
4552 -- because it apprears within an interfering context. Note that
4553 -- this is usually done in Resolve_Entity_Name, but when the
4554 -- effectively volatile object appears as an actual in a call,
4555 -- the call must be resolved first.
4558 Flag_Effectively_Volatile_Objects (A);
4561 -- Detect an external variable with an enabled property that
4562 -- does not match the mode of the corresponding formal in a
4563 -- procedure call. Functions are not considered because they
4564 -- cannot have effectively volatile formal parameters in the
4567 if Ekind (Nam) = E_Procedure
4568 and then Ekind (F) = E_In_Parameter
4569 and then Is_Entity_Name (A)
4570 and then Present (Entity (A))
4571 and then Ekind (Entity (A)) = E_Variable
4575 if Async_Readers_Enabled (A_Id) then
4576 Property_Error (A, A_Id, Name_Async_Readers);
4577 elsif Effective_Reads_Enabled (A_Id) then
4578 Property_Error (A, A_Id, Name_Effective_Reads);
4579 elsif Effective_Writes_Enabled (A_Id) then
4580 Property_Error (A, A_Id, Name_Effective_Writes);
4585 -- A formal parameter of a specific tagged type whose related
4586 -- subprogram is subject to pragma Extensions_Visible with value
4587 -- "False" cannot act as an actual in a subprogram with value
4588 -- "True" (SPARK RM 6.1.7(3)).
4590 if Is_EVF_Expression (A)
4591 and then Extensions_Visible_Status (Nam) =
4592 Extensions_Visible_True
4595 ("formal parameter cannot act as actual parameter when "
4596 & "Extensions_Visible is False", A);
4598 ("\subprogram & has Extensions_Visible True", A, Nam);
4601 -- The actual parameter of a Ghost subprogram whose formal is of
4602 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4604 if Comes_From_Source (Nam)
4605 and then Is_Ghost_Entity (Nam)
4606 and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
4607 and then Is_Entity_Name (A)
4608 and then Present (Entity (A))
4609 and then not Is_Ghost_Entity (Entity (A))
4612 ("non-ghost variable & cannot appear as actual in call to "
4613 & "ghost procedure", A, Entity (A));
4615 if Ekind (F) = E_In_Out_Parameter then
4616 Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
4618 Error_Msg_N ("\corresponding formal has mode OUT", A);
4624 -- Case where actual is not present
4632 if Present (Real_Subp) then
4633 Next_Formal (Real_F);
4636 end Resolve_Actuals;
4638 -----------------------
4639 -- Resolve_Allocator --
4640 -----------------------
4642 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
4643 Desig_T : constant Entity_Id := Designated_Type (Typ);
4644 E : constant Node_Id := Expression (N);
4646 Discrim : Entity_Id;
4649 Assoc : Node_Id := Empty;
4652 procedure Check_Allocator_Discrim_Accessibility
4653 (Disc_Exp : Node_Id;
4654 Alloc_Typ : Entity_Id);
4655 -- Check that accessibility level associated with an access discriminant
4656 -- initialized in an allocator by the expression Disc_Exp is not deeper
4657 -- than the level of the allocator type Alloc_Typ. An error message is
4658 -- issued if this condition is violated. Specialized checks are done for
4659 -- the cases of a constraint expression which is an access attribute or
4660 -- an access discriminant.
4662 function In_Dispatching_Context return Boolean;
4663 -- If the allocator is an actual in a call, it is allowed to be class-
4664 -- wide when the context is not because it is a controlling actual.
4666 -------------------------------------------
4667 -- Check_Allocator_Discrim_Accessibility --
4668 -------------------------------------------
4670 procedure Check_Allocator_Discrim_Accessibility
4671 (Disc_Exp : Node_Id;
4672 Alloc_Typ : Entity_Id)
4675 if Type_Access_Level (Etype (Disc_Exp)) >
4676 Deepest_Type_Access_Level (Alloc_Typ)
4679 ("operand type has deeper level than allocator type", Disc_Exp);
4681 -- When the expression is an Access attribute the level of the prefix
4682 -- object must not be deeper than that of the allocator's type.
4684 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4685 and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
4687 and then Object_Access_Level (Prefix (Disc_Exp)) >
4688 Deepest_Type_Access_Level (Alloc_Typ)
4691 ("prefix of attribute has deeper level than allocator type",
4694 -- When the expression is an access discriminant the check is against
4695 -- the level of the prefix object.
4697 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4698 and then Nkind (Disc_Exp) = N_Selected_Component
4699 and then Object_Access_Level (Prefix (Disc_Exp)) >
4700 Deepest_Type_Access_Level (Alloc_Typ)
4703 ("access discriminant has deeper level than allocator type",
4706 -- All other cases are legal
4711 end Check_Allocator_Discrim_Accessibility;
4713 ----------------------------
4714 -- In_Dispatching_Context --
4715 ----------------------------
4717 function In_Dispatching_Context return Boolean is
4718 Par : constant Node_Id := Parent (N);
4721 return Nkind (Par) in N_Subprogram_Call
4722 and then Is_Entity_Name (Name (Par))
4723 and then Is_Dispatching_Operation (Entity (Name (Par)));
4724 end In_Dispatching_Context;
4726 -- Start of processing for Resolve_Allocator
4729 -- Replace general access with specific type
4731 if Ekind (Etype (N)) = E_Allocator_Type then
4732 Set_Etype (N, Base_Type (Typ));
4735 if Is_Abstract_Type (Typ) then
4736 Error_Msg_N ("type of allocator cannot be abstract", N);
4739 -- For qualified expression, resolve the expression using the given
4740 -- subtype (nothing to do for type mark, subtype indication)
4742 if Nkind (E) = N_Qualified_Expression then
4743 if Is_Class_Wide_Type (Etype (E))
4744 and then not Is_Class_Wide_Type (Desig_T)
4745 and then not In_Dispatching_Context
4748 ("class-wide allocator not allowed for this access type", N);
4751 Resolve (Expression (E), Etype (E));
4752 Check_Non_Static_Context (Expression (E));
4753 Check_Unset_Reference (Expression (E));
4755 -- Allocators generated by the build-in-place expansion mechanism
4756 -- are explicitly marked as coming from source but do not need to be
4757 -- checked for limited initialization. To exclude this case, ensure
4758 -- that the parent of the allocator is a source node.
4760 if Is_Limited_Type (Etype (E))
4761 and then Comes_From_Source (N)
4762 and then Comes_From_Source (Parent (N))
4763 and then not In_Instance_Body
4765 if not OK_For_Limited_Init (Etype (E), Expression (E)) then
4766 if Nkind (Parent (N)) = N_Assignment_Statement then
4768 ("illegal expression for initialized allocator of a "
4769 & "limited type (RM 7.5 (2.7/2))", N);
4772 ("initialization not allowed for limited types", N);
4775 Explain_Limited_Type (Etype (E), N);
4779 -- A qualified expression requires an exact match of the type. Class-
4780 -- wide matching is not allowed.
4782 if (Is_Class_Wide_Type (Etype (Expression (E)))
4783 or else Is_Class_Wide_Type (Etype (E)))
4784 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4786 Wrong_Type (Expression (E), Etype (E));
4789 -- Calls to build-in-place functions are not currently supported in
4790 -- allocators for access types associated with a simple storage pool.
4791 -- Supporting such allocators may require passing additional implicit
4792 -- parameters to build-in-place functions (or a significant revision
4793 -- of the current b-i-p implementation to unify the handling for
4794 -- multiple kinds of storage pools). ???
4796 if Is_Limited_View (Desig_T)
4797 and then Nkind (Expression (E)) = N_Function_Call
4800 Pool : constant Entity_Id :=
4801 Associated_Storage_Pool (Root_Type (Typ));
4805 Present (Get_Rep_Pragma
4806 (Etype (Pool), Name_Simple_Storage_Pool_Type))
4809 ("limited function calls not yet supported in simple "
4810 & "storage pool allocators", Expression (E));
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).
4821 -- We can't use Valid_Conversion to perform this check because in
4822 -- general the type of the allocator is unrelated to the type of
4823 -- the access discriminant.
4825 if Ekind (Typ) /= E_Anonymous_Access_Type
4826 or else Is_Local_Anonymous_Access (Typ)
4828 Subtyp := Entity (Subtype_Mark (E));
4830 Aggr := Original_Node (Expression (E));
4832 if Has_Discriminants (Subtyp)
4833 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4835 Discrim := First_Discriminant (Base_Type (Subtyp));
4837 -- Get the first component expression of the aggregate
4839 if Present (Expressions (Aggr)) then
4840 Disc_Exp := First (Expressions (Aggr));
4842 elsif Present (Component_Associations (Aggr)) then
4843 Assoc := First (Component_Associations (Aggr));
4845 if Present (Assoc) then
4846 Disc_Exp := Expression (Assoc);
4855 while Present (Discrim) and then Present (Disc_Exp) loop
4856 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4857 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4860 Next_Discriminant (Discrim);
4862 if Present (Discrim) then
4863 if Present (Assoc) then
4865 Disc_Exp := Expression (Assoc);
4867 elsif Present (Next (Disc_Exp)) then
4871 Assoc := First (Component_Associations (Aggr));
4873 if Present (Assoc) then
4874 Disc_Exp := Expression (Assoc);
4884 -- For a subtype mark or subtype indication, freeze the subtype
4887 Freeze_Expression (E);
4889 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4891 ("initialization required for access-to-constant allocator", N);
4894 -- A special accessibility check is needed for allocators that
4895 -- constrain access discriminants. The level of the type of the
4896 -- expression used to constrain an access discriminant cannot be
4897 -- deeper than the type of the allocator (in contrast to access
4898 -- parameters, where the level of the actual can be arbitrary).
4899 -- We can't use Valid_Conversion to perform this check because
4900 -- in general the type of the allocator is unrelated to the type
4901 -- of the access discriminant.
4903 if Nkind (Original_Node (E)) = N_Subtype_Indication
4904 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4905 or else Is_Local_Anonymous_Access (Typ))
4907 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4909 if Has_Discriminants (Subtyp) then
4910 Discrim := First_Discriminant (Base_Type (Subtyp));
4911 Constr := First (Constraints (Constraint (Original_Node (E))));
4912 while Present (Discrim) and then Present (Constr) loop
4913 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4914 if Nkind (Constr) = N_Discriminant_Association then
4915 Disc_Exp := Original_Node (Expression (Constr));
4917 Disc_Exp := Original_Node (Constr);
4920 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4923 Next_Discriminant (Discrim);
4930 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4931 -- check that the level of the type of the created object is not deeper
4932 -- than the level of the allocator's access type, since extensions can
4933 -- now occur at deeper levels than their ancestor types. This is a
4934 -- static accessibility level check; a run-time check is also needed in
4935 -- the case of an initialized allocator with a class-wide argument (see
4936 -- Expand_Allocator_Expression).
4938 if Ada_Version >= Ada_2005
4939 and then Is_Class_Wide_Type (Desig_T)
4942 Exp_Typ : Entity_Id;
4945 if Nkind (E) = N_Qualified_Expression then
4946 Exp_Typ := Etype (E);
4947 elsif Nkind (E) = N_Subtype_Indication then
4948 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4950 Exp_Typ := Entity (E);
4953 if Type_Access_Level (Exp_Typ) >
4954 Deepest_Type_Access_Level (Typ)
4956 if In_Instance_Body then
4957 Error_Msg_Warn := SPARK_Mode /= On;
4959 ("type in allocator has deeper level than "
4960 & "designated class-wide type<<", E);
4961 Error_Msg_N ("\Program_Error [<<", E);
4963 Make_Raise_Program_Error (Sloc (N),
4964 Reason => PE_Accessibility_Check_Failed));
4967 -- Do not apply Ada 2005 accessibility checks on a class-wide
4968 -- allocator if the type given in the allocator is a formal
4969 -- type. A run-time check will be performed in the instance.
4971 elsif not Is_Generic_Type (Exp_Typ) then
4972 Error_Msg_N ("type in allocator has deeper level than "
4973 & "designated class-wide type", E);
4979 -- Check for allocation from an empty storage pool
4981 if No_Pool_Assigned (Typ) then
4982 Error_Msg_N ("allocation from empty storage pool!", N);
4984 -- If the context is an unchecked conversion, as may happen within an
4985 -- inlined subprogram, the allocator is being resolved with its own
4986 -- anonymous type. In that case, if the target type has a specific
4987 -- storage pool, it must be inherited explicitly by the allocator type.
4989 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4990 and then No (Associated_Storage_Pool (Typ))
4992 Set_Associated_Storage_Pool
4993 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4996 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4997 Check_Restriction (No_Anonymous_Allocators, N);
5000 -- Check that an allocator with task parts isn't for a nested access
5001 -- type when restriction No_Task_Hierarchy applies.
5003 if not Is_Library_Level_Entity (Base_Type (Typ))
5004 and then Has_Task (Base_Type (Desig_T))
5006 Check_Restriction (No_Task_Hierarchy, N);
5009 -- An illegal allocator may be rewritten as a raise Program_Error
5012 if Nkind (N) = N_Allocator then
5014 -- An anonymous access discriminant is the definition of a
5017 if Ekind (Typ) = E_Anonymous_Access_Type
5018 and then Nkind (Associated_Node_For_Itype (Typ)) =
5019 N_Discriminant_Specification
5022 Discr : constant Entity_Id :=
5023 Defining_Identifier (Associated_Node_For_Itype (Typ));
5026 Check_Restriction (No_Coextensions, N);
5028 -- Ada 2012 AI05-0052: If the designated type of the allocator
5029 -- is limited, then the allocator shall not be used to define
5030 -- the value of an access discriminant unless the discriminated
5031 -- type is immutably limited.
5033 if Ada_Version >= Ada_2012
5034 and then Is_Limited_Type (Desig_T)
5035 and then not Is_Limited_View (Scope (Discr))
5038 ("only immutably limited types can have anonymous "
5039 & "access discriminants designating a limited type", N);
5043 -- Avoid marking an allocator as a dynamic coextension if it is
5044 -- within a static construct.
5046 if not Is_Static_Coextension (N) then
5047 Set_Is_Dynamic_Coextension (N);
5050 -- Cleanup for potential static coextensions
5053 Set_Is_Dynamic_Coextension (N, False);
5054 Set_Is_Static_Coextension (N, False);
5058 -- Report a simple error: if the designated object is a local task,
5059 -- its body has not been seen yet, and its activation will fail an
5060 -- elaboration check.
5062 if Is_Task_Type (Desig_T)
5063 and then Scope (Base_Type (Desig_T)) = Current_Scope
5064 and then Is_Compilation_Unit (Current_Scope)
5065 and then Ekind (Current_Scope) = E_Package
5066 and then not In_Package_Body (Current_Scope)
5068 Error_Msg_Warn := SPARK_Mode /= On;
5069 Error_Msg_N ("cannot activate task before body seen<<", N);
5070 Error_Msg_N ("\Program_Error [<<", N);
5073 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5074 -- type with a task component on a subpool. This action must raise
5075 -- Program_Error at runtime.
5077 if Ada_Version >= Ada_2012
5078 and then Nkind (N) = N_Allocator
5079 and then Present (Subpool_Handle_Name (N))
5080 and then Has_Task (Desig_T)
5082 Error_Msg_Warn := SPARK_Mode /= On;
5083 Error_Msg_N ("cannot allocate task on subpool<<", N);
5084 Error_Msg_N ("\Program_Error [<<", N);
5087 Make_Raise_Program_Error (Sloc (N),
5088 Reason => PE_Explicit_Raise));
5091 end Resolve_Allocator;
5093 ---------------------------
5094 -- Resolve_Arithmetic_Op --
5095 ---------------------------
5097 -- Used for resolving all arithmetic operators except exponentiation
5099 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
5100 L : constant Node_Id := Left_Opnd (N);
5101 R : constant Node_Id := Right_Opnd (N);
5102 TL : constant Entity_Id := Base_Type (Etype (L));
5103 TR : constant Entity_Id := Base_Type (Etype (R));
5107 B_Typ : constant Entity_Id := Base_Type (Typ);
5108 -- We do the resolution using the base type, because intermediate values
5109 -- in expressions always are of the base type, not a subtype of it.
5111 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
5112 -- Returns True if N is in a context that expects "any real type"
5114 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
5115 -- Return True iff given type is Integer or universal real/integer
5117 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
5118 -- Choose type of integer literal in fixed-point operation to conform
5119 -- to available fixed-point type. T is the type of the other operand,
5120 -- which is needed to determine the expected type of N.
5122 procedure Set_Operand_Type (N : Node_Id);
5123 -- Set operand type to T if universal
5125 -------------------------------
5126 -- Expected_Type_Is_Any_Real --
5127 -------------------------------
5129 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
5131 -- N is the expression after "delta" in a fixed_point_definition;
5134 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
5135 N_Decimal_Fixed_Point_Definition,
5137 -- N is one of the bounds in a real_range_specification;
5140 N_Real_Range_Specification,
5142 -- N is the expression of a delta_constraint;
5145 N_Delta_Constraint);
5146 end Expected_Type_Is_Any_Real;
5148 -----------------------------
5149 -- Is_Integer_Or_Universal --
5150 -----------------------------
5152 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
5154 Index : Interp_Index;
5158 if not Is_Overloaded (N) then
5160 return Base_Type (T) = Base_Type (Standard_Integer)
5161 or else T = Universal_Integer
5162 or else T = Universal_Real;
5164 Get_First_Interp (N, Index, It);
5165 while Present (It.Typ) loop
5166 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
5167 or else It.Typ = Universal_Integer
5168 or else It.Typ = Universal_Real
5173 Get_Next_Interp (Index, It);
5178 end Is_Integer_Or_Universal;
5180 ----------------------------
5181 -- Set_Mixed_Mode_Operand --
5182 ----------------------------
5184 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
5185 Index : Interp_Index;
5189 if Universal_Interpretation (N) = Universal_Integer then
5191 -- A universal integer literal is resolved as standard integer
5192 -- except in the case of a fixed-point result, where we leave it
5193 -- as universal (to be handled by Exp_Fixd later on)
5195 if Is_Fixed_Point_Type (T) then
5196 Resolve (N, Universal_Integer);
5198 Resolve (N, Standard_Integer);
5201 elsif Universal_Interpretation (N) = Universal_Real
5202 and then (T = Base_Type (Standard_Integer)
5203 or else T = Universal_Integer
5204 or else T = Universal_Real)
5206 -- A universal real can appear in a fixed-type context. We resolve
5207 -- the literal with that context, even though this might raise an
5208 -- exception prematurely (the other operand may be zero).
5212 elsif Etype (N) = Base_Type (Standard_Integer)
5213 and then T = Universal_Real
5214 and then Is_Overloaded (N)
5216 -- Integer arg in mixed-mode operation. Resolve with universal
5217 -- type, in case preference rule must be applied.
5219 Resolve (N, Universal_Integer);
5222 and then B_Typ /= Universal_Fixed
5224 -- Not a mixed-mode operation, resolve with context
5228 elsif Etype (N) = Any_Fixed then
5230 -- N may itself be a mixed-mode operation, so use context type
5234 elsif Is_Fixed_Point_Type (T)
5235 and then B_Typ = Universal_Fixed
5236 and then Is_Overloaded (N)
5238 -- Must be (fixed * fixed) operation, operand must have one
5239 -- compatible interpretation.
5241 Resolve (N, Any_Fixed);
5243 elsif Is_Fixed_Point_Type (B_Typ)
5244 and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
5245 and then Is_Overloaded (N)
5247 -- C * F(X) in a fixed context, where C is a real literal or a
5248 -- fixed-point expression. F must have either a fixed type
5249 -- interpretation or an integer interpretation, but not both.
5251 Get_First_Interp (N, Index, It);
5252 while Present (It.Typ) loop
5253 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
5254 if Analyzed (N) then
5255 Error_Msg_N ("ambiguous operand in fixed operation", N);
5257 Resolve (N, Standard_Integer);
5260 elsif Is_Fixed_Point_Type (It.Typ) then
5261 if Analyzed (N) then
5262 Error_Msg_N ("ambiguous operand in fixed operation", N);
5264 Resolve (N, It.Typ);
5268 Get_Next_Interp (Index, It);
5271 -- Reanalyze the literal with the fixed type of the context. If
5272 -- context is Universal_Fixed, we are within a conversion, leave
5273 -- the literal as a universal real because there is no usable
5274 -- fixed type, and the target of the conversion plays no role in
5288 if B_Typ = Universal_Fixed
5289 and then Nkind (Op2) = N_Real_Literal
5291 T2 := Universal_Real;
5296 Set_Analyzed (Op2, False);
5303 end Set_Mixed_Mode_Operand;
5305 ----------------------
5306 -- Set_Operand_Type --
5307 ----------------------
5309 procedure Set_Operand_Type (N : Node_Id) is
5311 if Etype (N) = Universal_Integer
5312 or else Etype (N) = Universal_Real
5316 end Set_Operand_Type;
5318 -- Start of processing for Resolve_Arithmetic_Op
5321 if Comes_From_Source (N)
5322 and then Ekind (Entity (N)) = E_Function
5323 and then Is_Imported (Entity (N))
5324 and then Is_Intrinsic_Subprogram (Entity (N))
5326 Resolve_Intrinsic_Operator (N, Typ);
5329 -- Special-case for mixed-mode universal expressions or fixed point type
5330 -- operation: each argument is resolved separately. The same treatment
5331 -- is required if one of the operands of a fixed point operation is
5332 -- universal real, since in this case we don't do a conversion to a
5333 -- specific fixed-point type (instead the expander handles the case).
5335 -- Set the type of the node to its universal interpretation because
5336 -- legality checks on an exponentiation operand need the context.
5338 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
5339 and then Present (Universal_Interpretation (L))
5340 and then Present (Universal_Interpretation (R))
5342 Set_Etype (N, B_Typ);
5343 Resolve (L, Universal_Interpretation (L));
5344 Resolve (R, Universal_Interpretation (R));
5346 elsif (B_Typ = Universal_Real
5347 or else Etype (N) = Universal_Fixed
5348 or else (Etype (N) = Any_Fixed
5349 and then Is_Fixed_Point_Type (B_Typ))
5350 or else (Is_Fixed_Point_Type (B_Typ)
5351 and then (Is_Integer_Or_Universal (L)
5353 Is_Integer_Or_Universal (R))))
5354 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5356 if TL = Universal_Integer or else TR = Universal_Integer then
5357 Check_For_Visible_Operator (N, B_Typ);
5360 -- If context is a fixed type and one operand is integer, the other
5361 -- is resolved with the type of the context.
5363 if Is_Fixed_Point_Type (B_Typ)
5364 and then (Base_Type (TL) = Base_Type (Standard_Integer)
5365 or else TL = Universal_Integer)
5370 elsif Is_Fixed_Point_Type (B_Typ)
5371 and then (Base_Type (TR) = Base_Type (Standard_Integer)
5372 or else TR = Universal_Integer)
5378 Set_Mixed_Mode_Operand (L, TR);
5379 Set_Mixed_Mode_Operand (R, TL);
5382 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5383 -- multiplying operators from being used when the expected type is
5384 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5385 -- some cases where the expected type is actually Any_Real;
5386 -- Expected_Type_Is_Any_Real takes care of that case.
5388 if Etype (N) = Universal_Fixed
5389 or else Etype (N) = Any_Fixed
5391 if B_Typ = Universal_Fixed
5392 and then not Expected_Type_Is_Any_Real (N)
5393 and then not Nkind_In (Parent (N), N_Type_Conversion,
5394 N_Unchecked_Type_Conversion)
5396 Error_Msg_N ("type cannot be determined from context!", N);
5397 Error_Msg_N ("\explicit conversion to result type required", N);
5399 Set_Etype (L, Any_Type);
5400 Set_Etype (R, Any_Type);
5403 if Ada_Version = Ada_83
5404 and then Etype (N) = Universal_Fixed
5406 Nkind_In (Parent (N), N_Type_Conversion,
5407 N_Unchecked_Type_Conversion)
5410 ("(Ada 83) fixed-point operation needs explicit "
5414 -- The expected type is "any real type" in contexts like
5416 -- type T is delta <universal_fixed-expression> ...
5418 -- in which case we need to set the type to Universal_Real
5419 -- so that static expression evaluation will work properly.
5421 if Expected_Type_Is_Any_Real (N) then
5422 Set_Etype (N, Universal_Real);
5424 Set_Etype (N, B_Typ);
5428 elsif Is_Fixed_Point_Type (B_Typ)
5429 and then (Is_Integer_Or_Universal (L)
5430 or else Nkind (L) = N_Real_Literal
5431 or else Nkind (R) = N_Real_Literal
5432 or else Is_Integer_Or_Universal (R))
5434 Set_Etype (N, B_Typ);
5436 elsif Etype (N) = Any_Fixed then
5438 -- If no previous errors, this is only possible if one operand is
5439 -- overloaded and the context is universal. Resolve as such.
5441 Set_Etype (N, B_Typ);
5445 if (TL = Universal_Integer or else TL = Universal_Real)
5447 (TR = Universal_Integer or else TR = Universal_Real)
5449 Check_For_Visible_Operator (N, B_Typ);
5452 -- If the context is Universal_Fixed and the operands are also
5453 -- universal fixed, this is an error, unless there is only one
5454 -- applicable fixed_point type (usually Duration).
5456 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
5457 T := Unique_Fixed_Point_Type (N);
5459 if T = Any_Type then
5472 -- If one of the arguments was resolved to a non-universal type.
5473 -- label the result of the operation itself with the same type.
5474 -- Do the same for the universal argument, if any.
5476 T := Intersect_Types (L, R);
5477 Set_Etype (N, Base_Type (T));
5478 Set_Operand_Type (L);
5479 Set_Operand_Type (R);
5482 Generate_Operator_Reference (N, Typ);
5483 Analyze_Dimension (N);
5484 Eval_Arithmetic_Op (N);
5486 -- In SPARK, a multiplication or division with operands of fixed point
5487 -- types must be qualified or explicitly converted to identify the
5490 if (Is_Fixed_Point_Type (Etype (L))
5491 or else Is_Fixed_Point_Type (Etype (R)))
5492 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
5494 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
5496 Check_SPARK_05_Restriction
5497 ("operation should be qualified or explicitly converted", N);
5500 -- Set overflow and division checking bit
5502 if Nkind (N) in N_Op then
5503 if not Overflow_Checks_Suppressed (Etype (N)) then
5504 Enable_Overflow_Check (N);
5507 -- Give warning if explicit division by zero
5509 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
5510 and then not Division_Checks_Suppressed (Etype (N))
5512 Rop := Right_Opnd (N);
5514 if Compile_Time_Known_Value (Rop)
5515 and then ((Is_Integer_Type (Etype (Rop))
5516 and then Expr_Value (Rop) = Uint_0)
5518 (Is_Real_Type (Etype (Rop))
5519 and then Expr_Value_R (Rop) = Ureal_0))
5521 -- Specialize the warning message according to the operation.
5522 -- When SPARK_Mode is On, force a warning instead of an error
5523 -- in that case, as this likely corresponds to deactivated
5524 -- code. The following warnings are for the case
5529 -- For division, we have two cases, for float division
5530 -- of an unconstrained float type, on a machine where
5531 -- Machine_Overflows is false, we don't get an exception
5532 -- at run-time, but rather an infinity or Nan. The Nan
5533 -- case is pretty obscure, so just warn about infinities.
5535 if Is_Floating_Point_Type (Typ)
5536 and then not Is_Constrained (Typ)
5537 and then not Machine_Overflows_On_Target
5540 ("float division by zero, may generate "
5541 & "'+'/'- infinity??", Right_Opnd (N));
5543 -- For all other cases, we get a Constraint_Error
5546 Apply_Compile_Time_Constraint_Error
5547 (N, "division by zero??", CE_Divide_By_Zero,
5548 Loc => Sloc (Right_Opnd (N)),
5549 Warn => SPARK_Mode = On);
5553 Apply_Compile_Time_Constraint_Error
5554 (N, "rem with zero divisor??", CE_Divide_By_Zero,
5555 Loc => Sloc (Right_Opnd (N)),
5556 Warn => SPARK_Mode = On);
5559 Apply_Compile_Time_Constraint_Error
5560 (N, "mod with zero divisor??", CE_Divide_By_Zero,
5561 Loc => Sloc (Right_Opnd (N)),
5562 Warn => SPARK_Mode = On);
5564 -- Division by zero can only happen with division, rem,
5565 -- and mod operations.
5568 raise Program_Error;
5571 -- In GNATprove mode, we enable the division check so that
5572 -- GNATprove will issue a message if it cannot be proved.
5574 if GNATprove_Mode then
5575 Activate_Division_Check (N);
5578 -- Otherwise just set the flag to check at run time
5581 Activate_Division_Check (N);
5585 -- If Restriction No_Implicit_Conditionals is active, then it is
5586 -- violated if either operand can be negative for mod, or for rem
5587 -- if both operands can be negative.
5589 if Restriction_Check_Required (No_Implicit_Conditionals)
5590 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
5599 -- Set if corresponding operand might be negative
5603 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5604 LNeg := (not OK) or else Lo < 0;
5607 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
5608 RNeg := (not OK) or else Lo < 0;
5610 -- Check if we will be generating conditionals. There are two
5611 -- cases where that can happen, first for REM, the only case
5612 -- is largest negative integer mod -1, where the division can
5613 -- overflow, but we still have to give the right result. The
5614 -- front end generates a test for this annoying case. Here we
5615 -- just test if both operands can be negative (that's what the
5616 -- expander does, so we match its logic here).
5618 -- The second case is mod where either operand can be negative.
5619 -- In this case, the back end has to generate additional tests.
5621 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
5623 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
5625 Check_Restriction (No_Implicit_Conditionals, N);
5631 Check_Unset_Reference (L);
5632 Check_Unset_Reference (R);
5633 end Resolve_Arithmetic_Op;
5639 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
5640 function Same_Or_Aliased_Subprograms
5642 E : Entity_Id) return Boolean;
5643 -- Returns True if the subprogram entity S is the same as E or else
5644 -- S is an alias of E.
5646 ---------------------------------
5647 -- Same_Or_Aliased_Subprograms --
5648 ---------------------------------
5650 function Same_Or_Aliased_Subprograms
5652 E : Entity_Id) return Boolean
5654 Subp_Alias : constant Entity_Id := Alias (S);
5656 return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
5657 end Same_Or_Aliased_Subprograms;
5661 Loc : constant Source_Ptr := Sloc (N);
5662 Subp : constant Node_Id := Name (N);
5663 Body_Id : Entity_Id;
5673 -- Start of processing for Resolve_Call
5676 -- The context imposes a unique interpretation with type Typ on a
5677 -- procedure or function call. Find the entity of the subprogram that
5678 -- yields the expected type, and propagate the corresponding formal
5679 -- constraints on the actuals. The caller has established that an
5680 -- interpretation exists, and emitted an error if not unique.
5682 -- First deal with the case of a call to an access-to-subprogram,
5683 -- dereference made explicit in Analyze_Call.
5685 if Ekind (Etype (Subp)) = E_Subprogram_Type then
5686 if not Is_Overloaded (Subp) then
5687 Nam := Etype (Subp);
5690 -- Find the interpretation whose type (a subprogram type) has a
5691 -- return type that is compatible with the context. Analysis of
5692 -- the node has established that one exists.
5696 Get_First_Interp (Subp, I, It);
5697 while Present (It.Typ) loop
5698 if Covers (Typ, Etype (It.Typ)) then
5703 Get_Next_Interp (I, It);
5707 raise Program_Error;
5711 -- If the prefix is not an entity, then resolve it
5713 if not Is_Entity_Name (Subp) then
5714 Resolve (Subp, Nam);
5717 -- For an indirect call, we always invalidate checks, since we do not
5718 -- know whether the subprogram is local or global. Yes we could do
5719 -- better here, e.g. by knowing that there are no local subprograms,
5720 -- but it does not seem worth the effort. Similarly, we kill all
5721 -- knowledge of current constant values.
5723 Kill_Current_Values;
5725 -- If this is a procedure call which is really an entry call, do
5726 -- the conversion of the procedure call to an entry call. Protected
5727 -- operations use the same circuitry because the name in the call
5728 -- can be an arbitrary expression with special resolution rules.
5730 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
5731 or else (Is_Entity_Name (Subp)
5732 and then Ekind (Entity (Subp)) = E_Entry)
5734 Resolve_Entry_Call (N, Typ);
5735 Check_Elab_Call (N);
5737 -- Kill checks and constant values, as above for indirect case
5738 -- Who knows what happens when another task is activated?
5740 Kill_Current_Values;
5743 -- Normal subprogram call with name established in Resolve
5745 elsif not (Is_Type (Entity (Subp))) then
5746 Nam := Entity (Subp);
5747 Set_Entity_With_Checks (Subp, Nam);
5749 -- Otherwise we must have the case of an overloaded call
5752 pragma Assert (Is_Overloaded (Subp));
5754 -- Initialize Nam to prevent warning (we know it will be assigned
5755 -- in the loop below, but the compiler does not know that).
5759 Get_First_Interp (Subp, I, It);
5760 while Present (It.Typ) loop
5761 if Covers (Typ, It.Typ) then
5763 Set_Entity_With_Checks (Subp, Nam);
5767 Get_Next_Interp (I, It);
5771 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5772 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
5773 and then Nkind (Subp) /= N_Explicit_Dereference
5774 and then Present (Parameter_Associations (N))
5776 -- The prefix is a parameterless function call that returns an access
5777 -- to subprogram. If parameters are present in the current call, add
5778 -- add an explicit dereference. We use the base type here because
5779 -- within an instance these may be subtypes.
5781 -- The dereference is added either in Analyze_Call or here. Should
5782 -- be consolidated ???
5784 Set_Is_Overloaded (Subp, False);
5785 Set_Etype (Subp, Etype (Nam));
5786 Insert_Explicit_Dereference (Subp);
5787 Nam := Designated_Type (Etype (Nam));
5788 Resolve (Subp, Nam);
5791 -- Check that a call to Current_Task does not occur in an entry body
5793 if Is_RTE (Nam, RE_Current_Task) then
5802 -- Exclude calls that occur within the default of a formal
5803 -- parameter of the entry, since those are evaluated outside
5806 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
5808 if Nkind (P) = N_Entry_Body
5809 or else (Nkind (P) = N_Subprogram_Body
5810 and then Is_Entry_Barrier_Function (P))
5813 Error_Msg_Warn := SPARK_Mode /= On;
5815 ("& should not be used in entry body (RM C.7(17))<<",
5817 Error_Msg_NE ("\Program_Error [<<", N, Nam);
5819 Make_Raise_Program_Error (Loc,
5820 Reason => PE_Current_Task_In_Entry_Body));
5821 Set_Etype (N, Rtype);
5828 -- Check that a procedure call does not occur in the context of the
5829 -- entry call statement of a conditional or timed entry call. Note that
5830 -- the case of a call to a subprogram renaming of an entry will also be
5831 -- rejected. The test for N not being an N_Entry_Call_Statement is
5832 -- defensive, covering the possibility that the processing of entry
5833 -- calls might reach this point due to later modifications of the code
5836 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5837 and then Nkind (N) /= N_Entry_Call_Statement
5838 and then Entry_Call_Statement (Parent (N)) = N
5840 if Ada_Version < Ada_2005 then
5841 Error_Msg_N ("entry call required in select statement", N);
5843 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5844 -- for a procedure_or_entry_call, the procedure_name or
5845 -- procedure_prefix of the procedure_call_statement shall denote
5846 -- an entry renamed by a procedure, or (a view of) a primitive
5847 -- subprogram of a limited interface whose first parameter is
5848 -- a controlling parameter.
5850 elsif Nkind (N) = N_Procedure_Call_Statement
5851 and then not Is_Renamed_Entry (Nam)
5852 and then not Is_Controlling_Limited_Procedure (Nam)
5855 ("entry call or dispatching primitive of interface required", N);
5859 -- If the SPARK_05 restriction is active, we are not allowed
5860 -- to have a call to a subprogram before we see its completion.
5862 if not Has_Completion (Nam)
5863 and then Restriction_Check_Required (SPARK_05)
5865 -- Don't flag strange internal calls
5867 and then Comes_From_Source (N)
5868 and then Comes_From_Source (Nam)
5870 -- Only flag calls in extended main source
5872 and then In_Extended_Main_Source_Unit (Nam)
5873 and then In_Extended_Main_Source_Unit (N)
5875 -- Exclude enumeration literals from this processing
5877 and then Ekind (Nam) /= E_Enumeration_Literal
5879 Check_SPARK_05_Restriction
5880 ("call to subprogram cannot appear before its body", N);
5883 -- Check that this is not a call to a protected procedure or entry from
5884 -- within a protected function.
5886 Check_Internal_Protected_Use (N, Nam);
5888 -- Freeze the subprogram name if not in a spec-expression. Note that
5889 -- we freeze procedure calls as well as function calls. Procedure calls
5890 -- are not frozen according to the rules (RM 13.14(14)) because it is
5891 -- impossible to have a procedure call to a non-frozen procedure in
5892 -- pure Ada, but in the code that we generate in the expander, this
5893 -- rule needs extending because we can generate procedure calls that
5896 -- In Ada 2012, expression functions may be called within pre/post
5897 -- conditions of subsequent functions or expression functions. Such
5898 -- calls do not freeze when they appear within generated bodies,
5899 -- (including the body of another expression function) which would
5900 -- place the freeze node in the wrong scope. An expression function
5901 -- is frozen in the usual fashion, by the appearance of a real body,
5902 -- or at the end of a declarative part.
5904 if Is_Entity_Name (Subp)
5905 and then not In_Spec_Expression
5906 and then not Is_Expression_Function_Or_Completion (Current_Scope)
5908 (not Is_Expression_Function_Or_Completion (Entity (Subp))
5909 or else Scope (Entity (Subp)) = Current_Scope)
5911 Freeze_Expression (Subp);
5914 -- For a predefined operator, the type of the result is the type imposed
5915 -- by context, except for a predefined operation on universal fixed.
5916 -- Otherwise The type of the call is the type returned by the subprogram
5919 if Is_Predefined_Op (Nam) then
5920 if Etype (N) /= Universal_Fixed then
5924 -- If the subprogram returns an array type, and the context requires the
5925 -- component type of that array type, the node is really an indexing of
5926 -- the parameterless call. Resolve as such. A pathological case occurs
5927 -- when the type of the component is an access to the array type. In
5928 -- this case the call is truly ambiguous.
5930 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
5932 ((Is_Array_Type (Etype (Nam))
5933 and then Covers (Typ, Component_Type (Etype (Nam))))
5935 (Is_Access_Type (Etype (Nam))
5936 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5938 Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
5941 Index_Node : Node_Id;
5943 Ret_Type : constant Entity_Id := Etype (Nam);
5946 if Is_Access_Type (Ret_Type)
5947 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5950 ("cannot disambiguate function call and indexing", N);
5952 New_Subp := Relocate_Node (Subp);
5954 -- The called entity may be an explicit dereference, in which
5955 -- case there is no entity to set.
5957 if Nkind (New_Subp) /= N_Explicit_Dereference then
5958 Set_Entity (Subp, Nam);
5961 if (Is_Array_Type (Ret_Type)
5962 and then Component_Type (Ret_Type) /= Any_Type)
5964 (Is_Access_Type (Ret_Type)
5966 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
5968 if Needs_No_Actuals (Nam) then
5970 -- Indexed call to a parameterless function
5973 Make_Indexed_Component (Loc,
5975 Make_Function_Call (Loc, Name => New_Subp),
5976 Expressions => Parameter_Associations (N));
5978 -- An Ada 2005 prefixed call to a primitive operation
5979 -- whose first parameter is the prefix. This prefix was
5980 -- prepended to the parameter list, which is actually a
5981 -- list of indexes. Remove the prefix in order to build
5982 -- the proper indexed component.
5985 Make_Indexed_Component (Loc,
5987 Make_Function_Call (Loc,
5989 Parameter_Associations =>
5991 (Remove_Head (Parameter_Associations (N)))),
5992 Expressions => Parameter_Associations (N));
5995 -- Preserve the parenthesis count of the node
5997 Set_Paren_Count (Index_Node, Paren_Count (N));
5999 -- Since we are correcting a node classification error made
6000 -- by the parser, we call Replace rather than Rewrite.
6002 Replace (N, Index_Node);
6004 Set_Etype (Prefix (N), Ret_Type);
6006 Resolve_Indexed_Component (N, Typ);
6007 Check_Elab_Call (Prefix (N));
6015 -- If the function returns the limited view of type, the call must
6016 -- appear in a context in which the non-limited view is available.
6017 -- As is done in Try_Object_Operation, use the available view to
6018 -- prevent back-end confusion.
6020 if From_Limited_With (Etype (Nam)) then
6021 Set_Etype (Nam, Available_View (Etype (Nam)));
6024 Set_Etype (N, Etype (Nam));
6027 -- In the case where the call is to an overloaded subprogram, Analyze
6028 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6029 -- such a case Normalize_Actuals needs to be called once more to order
6030 -- the actuals correctly. Otherwise the call will have the ordering
6031 -- given by the last overloaded subprogram whether this is the correct
6032 -- one being called or not.
6034 if Is_Overloaded (Subp) then
6035 Normalize_Actuals (N, Nam, False, Norm_OK);
6036 pragma Assert (Norm_OK);
6039 -- In any case, call is fully resolved now. Reset Overload flag, to
6040 -- prevent subsequent overload resolution if node is analyzed again
6042 Set_Is_Overloaded (Subp, False);
6043 Set_Is_Overloaded (N, False);
6045 -- A Ghost entity must appear in a specific context
6047 if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
6048 Check_Ghost_Context (Nam, N);
6051 -- If we are calling the current subprogram from immediately within its
6052 -- body, then that is the case where we can sometimes detect cases of
6053 -- infinite recursion statically. Do not try this in case restriction
6054 -- No_Recursion is in effect anyway, and do it only for source calls.
6056 if Comes_From_Source (N) then
6057 Scop := Current_Scope;
6059 -- Check violation of SPARK_05 restriction which does not permit
6060 -- a subprogram body to contain a call to the subprogram directly.
6062 if Restriction_Check_Required (SPARK_05)
6063 and then Same_Or_Aliased_Subprograms (Nam, Scop)
6065 Check_SPARK_05_Restriction
6066 ("subprogram may not contain direct call to itself", N);
6069 -- Issue warning for possible infinite recursion in the absence
6070 -- of the No_Recursion restriction.
6072 if Same_Or_Aliased_Subprograms (Nam, Scop)
6073 and then not Restriction_Active (No_Recursion)
6074 and then Check_Infinite_Recursion (N)
6076 -- Here we detected and flagged an infinite recursion, so we do
6077 -- not need to test the case below for further warnings. Also we
6078 -- are all done if we now have a raise SE node.
6080 if Nkind (N) = N_Raise_Storage_Error then
6084 -- If call is to immediately containing subprogram, then check for
6085 -- the case of a possible run-time detectable infinite recursion.
6088 Scope_Loop : while Scop /= Standard_Standard loop
6089 if Same_Or_Aliased_Subprograms (Nam, Scop) then
6091 -- Although in general case, recursion is not statically
6092 -- checkable, the case of calling an immediately containing
6093 -- subprogram is easy to catch.
6095 Check_Restriction (No_Recursion, N);
6097 -- If the recursive call is to a parameterless subprogram,
6098 -- then even if we can't statically detect infinite
6099 -- recursion, this is pretty suspicious, and we output a
6100 -- warning. Furthermore, we will try later to detect some
6101 -- cases here at run time by expanding checking code (see
6102 -- Detect_Infinite_Recursion in package Exp_Ch6).
6104 -- If the recursive call is within a handler, do not emit a
6105 -- warning, because this is a common idiom: loop until input
6106 -- is correct, catch illegal input in handler and restart.
6108 if No (First_Formal (Nam))
6109 and then Etype (Nam) = Standard_Void_Type
6110 and then not Error_Posted (N)
6111 and then Nkind (Parent (N)) /= N_Exception_Handler
6113 -- For the case of a procedure call. We give the message
6114 -- only if the call is the first statement in a sequence
6115 -- of statements, or if all previous statements are
6116 -- simple assignments. This is simply a heuristic to
6117 -- decrease false positives, without losing too many good
6118 -- warnings. The idea is that these previous statements
6119 -- may affect global variables the procedure depends on.
6120 -- We also exclude raise statements, that may arise from
6121 -- constraint checks and are probably unrelated to the
6122 -- intended control flow.
6124 if Nkind (N) = N_Procedure_Call_Statement
6125 and then Is_List_Member (N)
6131 while Present (P) loop
6132 if not Nkind_In (P, N_Assignment_Statement,
6133 N_Raise_Constraint_Error)
6143 -- Do not give warning if we are in a conditional context
6146 K : constant Node_Kind := Nkind (Parent (N));
6148 if (K = N_Loop_Statement
6149 and then Present (Iteration_Scheme (Parent (N))))
6150 or else K = N_If_Statement
6151 or else K = N_Elsif_Part
6152 or else K = N_Case_Statement_Alternative
6158 -- Here warning is to be issued
6160 Set_Has_Recursive_Call (Nam);
6161 Error_Msg_Warn := SPARK_Mode /= On;
6162 Error_Msg_N ("possible infinite recursion<<!", N);
6163 Error_Msg_N ("\Storage_Error ]<<!", N);
6169 Scop := Scope (Scop);
6170 end loop Scope_Loop;
6174 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6176 Check_Obsolescent_2005_Entity (Nam, Subp);
6178 -- If subprogram name is a predefined operator, it was given in
6179 -- functional notation. Replace call node with operator node, so
6180 -- that actuals can be resolved appropriately.
6182 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
6183 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
6186 elsif Present (Alias (Nam))
6187 and then Is_Predefined_Op (Alias (Nam))
6189 Resolve_Actuals (N, Nam);
6190 Make_Call_Into_Operator (N, Typ, Alias (Nam));
6194 -- Create a transient scope if the resulting type requires it
6196 -- There are several notable exceptions:
6198 -- a) In init procs, the transient scope overhead is not needed, and is
6199 -- even incorrect when the call is a nested initialization call for a
6200 -- component whose expansion may generate adjust calls. However, if the
6201 -- call is some other procedure call within an initialization procedure
6202 -- (for example a call to Create_Task in the init_proc of the task
6203 -- run-time record) a transient scope must be created around this call.
6205 -- b) Enumeration literal pseudo-calls need no transient scope
6207 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6208 -- functions) do not use the secondary stack even though the return
6209 -- type may be unconstrained.
6211 -- d) Calls to a build-in-place function, since such functions may
6212 -- allocate their result directly in a target object, and cases where
6213 -- the result does get allocated in the secondary stack are checked for
6214 -- within the specialized Exp_Ch6 procedures for expanding those
6215 -- build-in-place calls.
6217 -- e) If the subprogram is marked Inline_Always, then even if it returns
6218 -- an unconstrained type the call does not require use of the secondary
6219 -- stack. However, inlining will only take place if the body to inline
6220 -- is already present. It may not be available if e.g. the subprogram is
6221 -- declared in a child instance.
6223 -- If this is an initialization call for a type whose construction
6224 -- uses the secondary stack, and it is not a nested call to initialize
6225 -- a component, we do need to create a transient scope for it. We
6226 -- check for this by traversing the type in Check_Initialization_Call.
6229 and then Has_Pragma_Inline (Nam)
6230 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
6231 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
6235 elsif Ekind (Nam) = E_Enumeration_Literal
6236 or else Is_Build_In_Place_Function (Nam)
6237 or else Is_Intrinsic_Subprogram (Nam)
6241 elsif Expander_Active
6242 and then Is_Type (Etype (Nam))
6243 and then Requires_Transient_Scope (Etype (Nam))
6245 (not Within_Init_Proc
6247 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
6249 Establish_Transient_Scope (N, Sec_Stack => True);
6251 -- If the call appears within the bounds of a loop, it will
6252 -- be rewritten and reanalyzed, nothing left to do here.
6254 if Nkind (N) /= N_Function_Call then
6258 elsif Is_Init_Proc (Nam)
6259 and then not Within_Init_Proc
6261 Check_Initialization_Call (N, Nam);
6264 -- A protected function cannot be called within the definition of the
6265 -- enclosing protected type, unless it is part of a pre/postcondition
6266 -- on another protected operation. This may appear in the entry wrapper
6267 -- created for an entry with preconditions.
6269 if Is_Protected_Type (Scope (Nam))
6270 and then In_Open_Scopes (Scope (Nam))
6271 and then not Has_Completion (Scope (Nam))
6272 and then not In_Spec_Expression
6273 and then not Is_Entry_Wrapper (Current_Scope)
6276 ("& cannot be called before end of protected definition", N, Nam);
6279 -- Propagate interpretation to actuals, and add default expressions
6282 if Present (First_Formal (Nam)) then
6283 Resolve_Actuals (N, Nam);
6285 -- Overloaded literals are rewritten as function calls, for purpose of
6286 -- resolution. After resolution, we can replace the call with the
6289 elsif Ekind (Nam) = E_Enumeration_Literal then
6290 Copy_Node (Subp, N);
6291 Resolve_Entity_Name (N, Typ);
6293 -- Avoid validation, since it is a static function call
6295 Generate_Reference (Nam, Subp);
6299 -- If the subprogram is not global, then kill all saved values and
6300 -- checks. This is a bit conservative, since in many cases we could do
6301 -- better, but it is not worth the effort. Similarly, we kill constant
6302 -- values. However we do not need to do this for internal entities
6303 -- (unless they are inherited user-defined subprograms), since they
6304 -- are not in the business of molesting local values.
6306 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6307 -- kill all checks and values for calls to global subprograms. This
6308 -- takes care of the case where an access to a local subprogram is
6309 -- taken, and could be passed directly or indirectly and then called
6310 -- from almost any context.
6312 -- Note: we do not do this step till after resolving the actuals. That
6313 -- way we still take advantage of the current value information while
6314 -- scanning the actuals.
6316 -- We suppress killing values if we are processing the nodes associated
6317 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6318 -- type kills all the values as part of analyzing the code that
6319 -- initializes the dispatch tables.
6321 if Inside_Freezing_Actions = 0
6322 and then (not Is_Library_Level_Entity (Nam)
6323 or else Suppress_Value_Tracking_On_Call
6324 (Nearest_Dynamic_Scope (Current_Scope)))
6325 and then (Comes_From_Source (Nam)
6326 or else (Present (Alias (Nam))
6327 and then Comes_From_Source (Alias (Nam))))
6329 Kill_Current_Values;
6332 -- If we are warning about unread OUT parameters, this is the place to
6333 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6334 -- after the above call to Kill_Current_Values (since that call clears
6335 -- the Last_Assignment field of all local variables).
6337 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
6338 and then Comes_From_Source (N)
6339 and then In_Extended_Main_Source_Unit (N)
6346 F := First_Formal (Nam);
6347 A := First_Actual (N);
6348 while Present (F) and then Present (A) loop
6349 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
6350 and then Warn_On_Modified_As_Out_Parameter (F)
6351 and then Is_Entity_Name (A)
6352 and then Present (Entity (A))
6353 and then Comes_From_Source (N)
6354 and then Safe_To_Capture_Value (N, Entity (A))
6356 Set_Last_Assignment (Entity (A), A);
6365 -- If the subprogram is a primitive operation, check whether or not
6366 -- it is a correct dispatching call.
6368 if Is_Overloadable (Nam)
6369 and then Is_Dispatching_Operation (Nam)
6371 Check_Dispatching_Call (N);
6373 elsif Ekind (Nam) /= E_Subprogram_Type
6374 and then Is_Abstract_Subprogram (Nam)
6375 and then not In_Instance
6377 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
6380 -- If this is a dispatching call, generate the appropriate reference,
6381 -- for better source navigation in GPS.
6383 if Is_Overloadable (Nam)
6384 and then Present (Controlling_Argument (N))
6386 Generate_Reference (Nam, Subp, 'R');
6388 -- Normal case, not a dispatching call: generate a call reference
6391 Generate_Reference (Nam, Subp, 's');
6394 if Is_Intrinsic_Subprogram (Nam) then
6395 Check_Intrinsic_Call (N);
6398 -- Check for violation of restriction No_Specific_Termination_Handlers
6399 -- and warn on a potentially blocking call to Abort_Task.
6401 if Restriction_Check_Required (No_Specific_Termination_Handlers)
6402 and then (Is_RTE (Nam, RE_Set_Specific_Handler)
6404 Is_RTE (Nam, RE_Specific_Handler))
6406 Check_Restriction (No_Specific_Termination_Handlers, N);
6408 elsif Is_RTE (Nam, RE_Abort_Task) then
6409 Check_Potentially_Blocking_Operation (N);
6412 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6413 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6414 -- need to check the second argument to determine whether it is an
6415 -- absolute or relative timing event.
6417 if Restriction_Check_Required (No_Relative_Delay)
6418 and then Is_RTE (Nam, RE_Set_Handler)
6419 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
6421 Check_Restriction (No_Relative_Delay, N);
6424 -- Issue an error for a call to an eliminated subprogram. This routine
6425 -- will not perform the check if the call appears within a default
6428 Check_For_Eliminated_Subprogram (Subp, Nam);
6430 -- In formal mode, the primitive operations of a tagged type or type
6431 -- extension do not include functions that return the tagged type.
6433 if Nkind (N) = N_Function_Call
6434 and then Is_Tagged_Type (Etype (N))
6435 and then Is_Entity_Name (Name (N))
6436 and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
6438 Check_SPARK_05_Restriction ("function not inherited", N);
6441 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6442 -- class-wide and the call dispatches on result in a context that does
6443 -- not provide a tag, the call raises Program_Error.
6445 if Nkind (N) = N_Function_Call
6446 and then In_Instance
6447 and then Is_Generic_Actual_Type (Typ)
6448 and then Is_Class_Wide_Type (Typ)
6449 and then Has_Controlling_Result (Nam)
6450 and then Nkind (Parent (N)) = N_Object_Declaration
6452 -- Verify that none of the formals are controlling
6455 Call_OK : Boolean := False;
6459 F := First_Formal (Nam);
6460 while Present (F) loop
6461 if Is_Controlling_Formal (F) then
6470 Error_Msg_Warn := SPARK_Mode /= On;
6471 Error_Msg_N ("!cannot determine tag of result<<", N);
6472 Error_Msg_N ("\Program_Error [<<!", N);
6474 Make_Raise_Program_Error (Sloc (N),
6475 Reason => PE_Explicit_Raise));
6480 -- Check for calling a function with OUT or IN OUT parameter when the
6481 -- calling context (us right now) is not Ada 2012, so does not allow
6482 -- OUT or IN OUT parameters in function calls. Functions declared in
6483 -- a predefined unit are OK, as they may be called indirectly from a
6484 -- user-declared instantiation.
6486 if Ada_Version < Ada_2012
6487 and then Ekind (Nam) = E_Function
6488 and then Has_Out_Or_In_Out_Parameter (Nam)
6489 and then not In_Predefined_Unit (Nam)
6491 Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
6492 Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
6495 -- Check the dimensions of the actuals in the call. For function calls,
6496 -- propagate the dimensions from the returned type to N.
6498 Analyze_Dimension_Call (N, Nam);
6500 -- All done, evaluate call and deal with elaboration issues
6503 Check_Elab_Call (N);
6505 -- In GNATprove mode, expansion is disabled, but we want to inline some
6506 -- subprograms to facilitate formal verification. Indirect calls through
6507 -- a subprogram type or within a generic cannot be inlined. Inlining is
6508 -- performed only for calls subject to SPARK_Mode on.
6511 and then SPARK_Mode = On
6512 and then Is_Overloadable (Nam)
6513 and then not Inside_A_Generic
6515 Nam_UA := Ultimate_Alias (Nam);
6516 Nam_Decl := Unit_Declaration_Node (Nam_UA);
6518 if Nkind (Nam_Decl) = N_Subprogram_Declaration then
6519 Body_Id := Corresponding_Body (Nam_Decl);
6521 -- Nothing to do if the subprogram is not eligible for inlining in
6524 if not Is_Inlined_Always (Nam_UA)
6525 or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
6529 -- Calls cannot be inlined inside assertions, as GNATprove treats
6530 -- assertions as logic expressions.
6532 elsif In_Assertion_Expr /= 0 then
6534 ("cannot inline & (in assertion expression)?", N, Nam_UA);
6536 -- Calls cannot be inlined inside default expressions
6538 elsif In_Default_Expr then
6540 ("cannot inline & (in default expression)?", N, Nam_UA);
6542 -- Inlining should not be performed during pre-analysis
6544 elsif Full_Analysis then
6546 -- With the one-pass inlining technique, a call cannot be
6547 -- inlined if the corresponding body has not been seen yet.
6549 if No (Body_Id) then
6551 ("cannot inline & (body not seen yet)?", N, Nam_UA);
6553 -- Nothing to do if there is no body to inline, indicating that
6554 -- the subprogram is not suitable for inlining in GNATprove
6557 elsif No (Body_To_Inline (Nam_Decl)) then
6560 -- Do not inline calls inside expression functions, as this
6561 -- would prevent interpreting them as logical formulas in
6564 elsif Present (Current_Subprogram)
6566 Is_Expression_Function_Or_Completion (Current_Subprogram)
6569 ("cannot inline & (inside expression function)?",
6572 -- Calls cannot be inlined inside potentially unevaluated
6573 -- expressions, as this would create complex actions inside
6574 -- expressions, that are not handled by GNATprove.
6576 elsif Is_Potentially_Unevaluated (N) then
6578 ("cannot inline & (in potentially unevaluated context)?",
6581 -- Otherwise, inline the call
6584 Expand_Inlined_Call (N, Nam_UA, Nam);
6590 Warn_On_Overlapping_Actuals (Nam, N);
6593 -----------------------------
6594 -- Resolve_Case_Expression --
6595 -----------------------------
6597 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
6600 Alt_Typ : Entity_Id;
6604 Alt := First (Alternatives (N));
6605 while Present (Alt) loop
6606 Alt_Expr := Expression (Alt);
6607 Resolve (Alt_Expr, Typ);
6608 Alt_Typ := Etype (Alt_Expr);
6610 -- When the expression is of a scalar subtype different from the
6611 -- result subtype, then insert a conversion to ensure the generation
6612 -- of a constraint check.
6614 if Is_Scalar_Type (Alt_Typ) and then Alt_Typ /= Typ then
6615 Rewrite (Alt_Expr, Convert_To (Typ, Alt_Expr));
6616 Analyze_And_Resolve (Alt_Expr, Typ);
6622 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6623 -- dynamically tagged must be known statically.
6625 if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
6626 Alt := First (Alternatives (N));
6627 Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
6629 while Present (Alt) loop
6630 if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
6632 ("all or none of the dependent expressions can be "
6633 & "dynamically tagged", N);
6641 Eval_Case_Expression (N);
6642 end Resolve_Case_Expression;
6644 -------------------------------
6645 -- Resolve_Character_Literal --
6646 -------------------------------
6648 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
6649 B_Typ : constant Entity_Id := Base_Type (Typ);
6653 -- Verify that the character does belong to the type of the context
6655 Set_Etype (N, B_Typ);
6656 Eval_Character_Literal (N);
6658 -- Wide_Wide_Character literals must always be defined, since the set
6659 -- of wide wide character literals is complete, i.e. if a character
6660 -- literal is accepted by the parser, then it is OK for wide wide
6661 -- character (out of range character literals are rejected).
6663 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6666 -- Always accept character literal for type Any_Character, which
6667 -- occurs in error situations and in comparisons of literals, both
6668 -- of which should accept all literals.
6670 elsif B_Typ = Any_Character then
6673 -- For Standard.Character or a type derived from it, check that the
6674 -- literal is in range.
6676 elsif Root_Type (B_Typ) = Standard_Character then
6677 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6681 -- For Standard.Wide_Character or a type derived from it, check that the
6682 -- literal is in range.
6684 elsif Root_Type (B_Typ) = Standard_Wide_Character then
6685 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
6689 -- For Standard.Wide_Wide_Character or a type derived from it, we
6690 -- know the literal is in range, since the parser checked.
6692 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
6695 -- If the entity is already set, this has already been resolved in a
6696 -- generic context, or comes from expansion. Nothing else to do.
6698 elsif Present (Entity (N)) then
6701 -- Otherwise we have a user defined character type, and we can use the
6702 -- standard visibility mechanisms to locate the referenced entity.
6705 C := Current_Entity (N);
6706 while Present (C) loop
6707 if Etype (C) = B_Typ then
6708 Set_Entity_With_Checks (N, C);
6709 Generate_Reference (C, N);
6717 -- If we fall through, then the literal does not match any of the
6718 -- entries of the enumeration type. This isn't just a constraint error
6719 -- situation, it is an illegality (see RM 4.2).
6722 ("character not defined for }", N, First_Subtype (B_Typ));
6723 end Resolve_Character_Literal;
6725 ---------------------------
6726 -- Resolve_Comparison_Op --
6727 ---------------------------
6729 -- Context requires a boolean type, and plays no role in resolution.
6730 -- Processing identical to that for equality operators. The result type is
6731 -- the base type, which matters when pathological subtypes of booleans with
6732 -- limited ranges are used.
6734 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
6735 L : constant Node_Id := Left_Opnd (N);
6736 R : constant Node_Id := Right_Opnd (N);
6740 -- If this is an intrinsic operation which is not predefined, use the
6741 -- types of its declared arguments to resolve the possibly overloaded
6742 -- operands. Otherwise the operands are unambiguous and specify the
6745 if Scope (Entity (N)) /= Standard_Standard then
6746 T := Etype (First_Entity (Entity (N)));
6749 T := Find_Unique_Type (L, R);
6751 if T = Any_Fixed then
6752 T := Unique_Fixed_Point_Type (L);
6756 Set_Etype (N, Base_Type (Typ));
6757 Generate_Reference (T, N, ' ');
6759 -- Skip remaining processing if already set to Any_Type
6761 if T = Any_Type then
6765 -- Deal with other error cases
6767 if T = Any_String or else
6768 T = Any_Composite or else
6771 if T = Any_Character then
6772 Ambiguous_Character (L);
6774 Error_Msg_N ("ambiguous operands for comparison", N);
6777 Set_Etype (N, Any_Type);
6781 -- Resolve the operands if types OK
6785 Check_Unset_Reference (L);
6786 Check_Unset_Reference (R);
6787 Generate_Operator_Reference (N, T);
6788 Check_Low_Bound_Tested (N);
6790 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6791 -- types or array types except String.
6793 if Is_Boolean_Type (T) then
6794 Check_SPARK_05_Restriction
6795 ("comparison is not defined on Boolean type", N);
6797 elsif Is_Array_Type (T)
6798 and then Base_Type (T) /= Standard_String
6800 Check_SPARK_05_Restriction
6801 ("comparison is not defined on array types other than String", N);
6804 -- Check comparison on unordered enumeration
6806 if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
6807 Error_Msg_Sloc := Sloc (Etype (L));
6809 ("comparison on unordered enumeration type& declared#?U?",
6813 -- Evaluate the relation (note we do this after the above check since
6814 -- this Eval call may change N to True/False.
6816 Analyze_Dimension (N);
6817 Eval_Relational_Op (N);
6818 end Resolve_Comparison_Op;
6820 -----------------------------------------
6821 -- Resolve_Discrete_Subtype_Indication --
6822 -----------------------------------------
6824 procedure Resolve_Discrete_Subtype_Indication
6832 Analyze (Subtype_Mark (N));
6833 S := Entity (Subtype_Mark (N));
6835 if Nkind (Constraint (N)) /= N_Range_Constraint then
6836 Error_Msg_N ("expect range constraint for discrete type", N);
6837 Set_Etype (N, Any_Type);
6840 R := Range_Expression (Constraint (N));
6848 if Base_Type (S) /= Base_Type (Typ) then
6850 ("expect subtype of }", N, First_Subtype (Typ));
6852 -- Rewrite the constraint as a range of Typ
6853 -- to allow compilation to proceed further.
6856 Rewrite (Low_Bound (R),
6857 Make_Attribute_Reference (Sloc (Low_Bound (R)),
6858 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6859 Attribute_Name => Name_First));
6860 Rewrite (High_Bound (R),
6861 Make_Attribute_Reference (Sloc (High_Bound (R)),
6862 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
6863 Attribute_Name => Name_First));
6867 Set_Etype (N, Etype (R));
6869 -- Additionally, we must check that the bounds are compatible
6870 -- with the given subtype, which might be different from the
6871 -- type of the context.
6873 Apply_Range_Check (R, S);
6875 -- ??? If the above check statically detects a Constraint_Error
6876 -- it replaces the offending bound(s) of the range R with a
6877 -- Constraint_Error node. When the itype which uses these bounds
6878 -- is frozen the resulting call to Duplicate_Subexpr generates
6879 -- a new temporary for the bounds.
6881 -- Unfortunately there are other itypes that are also made depend
6882 -- on these bounds, so when Duplicate_Subexpr is called they get
6883 -- a forward reference to the newly created temporaries and Gigi
6884 -- aborts on such forward references. This is probably sign of a
6885 -- more fundamental problem somewhere else in either the order of
6886 -- itype freezing or the way certain itypes are constructed.
6888 -- To get around this problem we call Remove_Side_Effects right
6889 -- away if either bounds of R are a Constraint_Error.
6892 L : constant Node_Id := Low_Bound (R);
6893 H : constant Node_Id := High_Bound (R);
6896 if Nkind (L) = N_Raise_Constraint_Error then
6897 Remove_Side_Effects (L);
6900 if Nkind (H) = N_Raise_Constraint_Error then
6901 Remove_Side_Effects (H);
6905 Check_Unset_Reference (Low_Bound (R));
6906 Check_Unset_Reference (High_Bound (R));
6909 end Resolve_Discrete_Subtype_Indication;
6911 -------------------------
6912 -- Resolve_Entity_Name --
6913 -------------------------
6915 -- Used to resolve identifiers and expanded names
6917 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6918 function Is_Assignment_Or_Object_Expression
6920 Expr : Node_Id) return Boolean;
6921 -- Determine whether node Context denotes an assignment statement or an
6922 -- object declaration whose expression is node Expr.
6924 ----------------------------------------
6925 -- Is_Assignment_Or_Object_Expression --
6926 ----------------------------------------
6928 function Is_Assignment_Or_Object_Expression
6930 Expr : Node_Id) return Boolean
6933 if Nkind_In (Context, N_Assignment_Statement,
6934 N_Object_Declaration)
6935 and then Expression (Context) = Expr
6939 -- Check whether a construct that yields a name is the expression of
6940 -- an assignment statement or an object declaration.
6942 elsif (Nkind_In (Context, N_Attribute_Reference,
6943 N_Explicit_Dereference,
6944 N_Indexed_Component,
6945 N_Selected_Component,
6947 and then Prefix (Context) = Expr)
6949 (Nkind_In (Context, N_Type_Conversion,
6950 N_Unchecked_Type_Conversion)
6951 and then Expression (Context) = Expr)
6954 Is_Assignment_Or_Object_Expression
6955 (Context => Parent (Context),
6958 -- Otherwise the context is not an assignment statement or an object
6964 end Is_Assignment_Or_Object_Expression;
6968 E : constant Entity_Id := Entity (N);
6971 -- Start of processing for Resolve_Entity_Name
6974 -- If garbage from errors, set to Any_Type and return
6976 if No (E) and then Total_Errors_Detected /= 0 then
6977 Set_Etype (N, Any_Type);
6981 -- Replace named numbers by corresponding literals. Note that this is
6982 -- the one case where Resolve_Entity_Name must reset the Etype, since
6983 -- it is currently marked as universal.
6985 if Ekind (E) = E_Named_Integer then
6987 Eval_Named_Integer (N);
6989 elsif Ekind (E) = E_Named_Real then
6991 Eval_Named_Real (N);
6993 -- For enumeration literals, we need to make sure that a proper style
6994 -- check is done, since such literals are overloaded, and thus we did
6995 -- not do a style check during the first phase of analysis.
6997 elsif Ekind (E) = E_Enumeration_Literal then
6998 Set_Entity_With_Checks (N, E);
6999 Eval_Entity_Name (N);
7001 -- Case of (sub)type name appearing in a context where an expression
7002 -- is expected. This is legal if occurrence is a current instance.
7003 -- See RM 8.6 (17/3).
7005 elsif Is_Type (E) then
7006 if Is_Current_Instance (N) then
7009 -- Any other use is an error
7013 ("invalid use of subtype mark in expression or call", N);
7016 -- Check discriminant use if entity is discriminant in current scope,
7017 -- i.e. discriminant of record or concurrent type currently being
7018 -- analyzed. Uses in corresponding body are unrestricted.
7020 elsif Ekind (E) = E_Discriminant
7021 and then Scope (E) = Current_Scope
7022 and then not Has_Completion (Current_Scope)
7024 Check_Discriminant_Use (N);
7026 -- A parameterless generic function cannot appear in a context that
7027 -- requires resolution.
7029 elsif Ekind (E) = E_Generic_Function then
7030 Error_Msg_N ("illegal use of generic function", N);
7032 -- In Ada 83 an OUT parameter cannot be read
7034 elsif Ekind (E) = E_Out_Parameter
7035 and then (Nkind (Parent (N)) in N_Op
7036 or else Nkind (Parent (N)) = N_Explicit_Dereference
7037 or else Is_Assignment_Or_Object_Expression
7038 (Context => Parent (N),
7041 if Ada_Version = Ada_83 then
7042 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
7045 -- In all other cases, just do the possible static evaluation
7048 -- A deferred constant that appears in an expression must have a
7049 -- completion, unless it has been removed by in-place expansion of
7050 -- an aggregate. A constant that is a renaming does not need
7053 if Ekind (E) = E_Constant
7054 and then Comes_From_Source (E)
7055 and then No (Constant_Value (E))
7056 and then Is_Frozen (Etype (E))
7057 and then not In_Spec_Expression
7058 and then not Is_Imported (E)
7059 and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7061 if No_Initialization (Parent (E))
7062 or else (Present (Full_View (E))
7063 and then No_Initialization (Parent (Full_View (E))))
7068 ("deferred constant is frozen before completion", N);
7072 Eval_Entity_Name (N);
7077 -- When the entity appears in a parameter association, retrieve the
7078 -- related subprogram call.
7080 if Nkind (Par) = N_Parameter_Association then
7081 Par := Parent (Par);
7084 if Comes_From_Source (N) then
7086 -- The following checks are only relevant when SPARK_Mode is on as
7087 -- they are not standard Ada legality rules.
7089 if SPARK_Mode = On then
7091 -- An effectively volatile object subject to enabled properties
7092 -- Async_Writers or Effective_Reads must appear in non-interfering
7093 -- context (SPARK RM 7.1.3(12)).
7096 and then Is_Effectively_Volatile (E)
7097 and then (Async_Writers_Enabled (E)
7098 or else Effective_Reads_Enabled (E))
7099 and then not Is_OK_Volatile_Context (Par, N)
7102 ("volatile object cannot appear in this context "
7103 & "(SPARK RM 7.1.3(12))", N);
7106 -- Check for possible elaboration issues with respect to reads of
7107 -- variables. The act of renaming the variable is not considered a
7108 -- read as it simply establishes an alias.
7110 if Ekind (E) = E_Variable
7111 and then Dynamic_Elaboration_Checks
7112 and then Nkind (Par) /= N_Object_Renaming_Declaration
7114 Check_Elab_Call (N);
7117 -- The variable may eventually become a constituent of a single
7118 -- protected/task type. Record the reference now and verify its
7119 -- legality when analyzing the contract of the variable
7122 if Ekind (E) = E_Variable then
7123 Record_Possible_Part_Of_Reference (E, N);
7127 -- A Ghost entity must appear in a specific context
7129 if Is_Ghost_Entity (E) then
7130 Check_Ghost_Context (E, N);
7133 end Resolve_Entity_Name;
7139 procedure Resolve_Entry (Entry_Name : Node_Id) is
7140 Loc : constant Source_Ptr := Sloc (Entry_Name);
7148 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
7149 -- If the bounds of the entry family being called depend on task
7150 -- discriminants, build a new index subtype where a discriminant is
7151 -- replaced with the value of the discriminant of the target task.
7152 -- The target task is the prefix of the entry name in the call.
7154 -----------------------
7155 -- Actual_Index_Type --
7156 -----------------------
7158 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
7159 Typ : constant Entity_Id := Entry_Index_Type (E);
7160 Tsk : constant Entity_Id := Scope (E);
7161 Lo : constant Node_Id := Type_Low_Bound (Typ);
7162 Hi : constant Node_Id := Type_High_Bound (Typ);
7165 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
7166 -- If the bound is given by a discriminant, replace with a reference
7167 -- to the discriminant of the same name in the target task. If the
7168 -- entry name is the target of a requeue statement and the entry is
7169 -- in the current protected object, the bound to be used is the
7170 -- discriminal of the object (see Apply_Range_Checks for details of
7171 -- the transformation).
7173 -----------------------------
7174 -- Actual_Discriminant_Ref --
7175 -----------------------------
7177 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
7178 Typ : constant Entity_Id := Etype (Bound);
7182 Remove_Side_Effects (Bound);
7184 if not Is_Entity_Name (Bound)
7185 or else Ekind (Entity (Bound)) /= E_Discriminant
7189 elsif Is_Protected_Type (Tsk)
7190 and then In_Open_Scopes (Tsk)
7191 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
7193 -- Note: here Bound denotes a discriminant of the corresponding
7194 -- record type tskV, whose discriminal is a formal of the
7195 -- init-proc tskVIP. What we want is the body discriminal,
7196 -- which is associated to the discriminant of the original
7197 -- concurrent type tsk.
7199 return New_Occurrence_Of
7200 (Find_Body_Discriminal (Entity (Bound)), Loc);
7204 Make_Selected_Component (Loc,
7205 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
7206 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
7211 end Actual_Discriminant_Ref;
7213 -- Start of processing for Actual_Index_Type
7216 if not Has_Discriminants (Tsk)
7217 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
7219 return Entry_Index_Type (E);
7222 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
7223 Set_Etype (New_T, Base_Type (Typ));
7224 Set_Size_Info (New_T, Typ);
7225 Set_RM_Size (New_T, RM_Size (Typ));
7226 Set_Scalar_Range (New_T,
7227 Make_Range (Sloc (Entry_Name),
7228 Low_Bound => Actual_Discriminant_Ref (Lo),
7229 High_Bound => Actual_Discriminant_Ref (Hi)));
7233 end Actual_Index_Type;
7235 -- Start of processing for Resolve_Entry
7238 -- Find name of entry being called, and resolve prefix of name with its
7239 -- own type. The prefix can be overloaded, and the name and signature of
7240 -- the entry must be taken into account.
7242 if Nkind (Entry_Name) = N_Indexed_Component then
7244 -- Case of dealing with entry family within the current tasks
7246 E_Name := Prefix (Entry_Name);
7249 E_Name := Entry_Name;
7252 if Is_Entity_Name (E_Name) then
7254 -- Entry call to an entry (or entry family) in the current task. This
7255 -- is legal even though the task will deadlock. Rewrite as call to
7258 -- This can also be a call to an entry in an enclosing task. If this
7259 -- is a single task, we have to retrieve its name, because the scope
7260 -- of the entry is the task type, not the object. If the enclosing
7261 -- task is a task type, the identity of the task is given by its own
7264 -- Finally this can be a requeue on an entry of the same task or
7265 -- protected object.
7267 S := Scope (Entity (E_Name));
7269 for J in reverse 0 .. Scope_Stack.Last loop
7270 if Is_Task_Type (Scope_Stack.Table (J).Entity)
7271 and then not Comes_From_Source (S)
7273 -- S is an enclosing task or protected object. The concurrent
7274 -- declaration has been converted into a type declaration, and
7275 -- the object itself has an object declaration that follows
7276 -- the type in the same declarative part.
7278 Tsk := Next_Entity (S);
7279 while Etype (Tsk) /= S loop
7286 elsif S = Scope_Stack.Table (J).Entity then
7288 -- Call to current task. Will be transformed into call to Self
7296 Make_Selected_Component (Loc,
7297 Prefix => New_Occurrence_Of (S, Loc),
7299 New_Occurrence_Of (Entity (E_Name), Loc));
7300 Rewrite (E_Name, New_N);
7303 elsif Nkind (Entry_Name) = N_Selected_Component
7304 and then Is_Overloaded (Prefix (Entry_Name))
7306 -- Use the entry name (which must be unique at this point) to find
7307 -- the prefix that returns the corresponding task/protected type.
7310 Pref : constant Node_Id := Prefix (Entry_Name);
7311 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
7316 Get_First_Interp (Pref, I, It);
7317 while Present (It.Typ) loop
7318 if Scope (Ent) = It.Typ then
7319 Set_Etype (Pref, It.Typ);
7323 Get_Next_Interp (I, It);
7328 if Nkind (Entry_Name) = N_Selected_Component then
7329 Resolve (Prefix (Entry_Name));
7331 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7332 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7333 Resolve (Prefix (Prefix (Entry_Name)));
7334 Index := First (Expressions (Entry_Name));
7335 Resolve (Index, Entry_Index_Type (Nam));
7337 -- Up to this point the expression could have been the actual in a
7338 -- simple entry call, and be given by a named association.
7340 if Nkind (Index) = N_Parameter_Association then
7341 Error_Msg_N ("expect expression for entry index", Index);
7343 Apply_Range_Check (Index, Actual_Index_Type (Nam));
7348 ------------------------
7349 -- Resolve_Entry_Call --
7350 ------------------------
7352 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
7353 Entry_Name : constant Node_Id := Name (N);
7354 Loc : constant Source_Ptr := Sloc (Entry_Name);
7356 First_Named : Node_Id;
7363 -- We kill all checks here, because it does not seem worth the effort to
7364 -- do anything better, an entry call is a big operation.
7368 -- Processing of the name is similar for entry calls and protected
7369 -- operation calls. Once the entity is determined, we can complete
7370 -- the resolution of the actuals.
7372 -- The selector may be overloaded, in the case of a protected object
7373 -- with overloaded functions. The type of the context is used for
7376 if Nkind (Entry_Name) = N_Selected_Component
7377 and then Is_Overloaded (Selector_Name (Entry_Name))
7378 and then Typ /= Standard_Void_Type
7385 Get_First_Interp (Selector_Name (Entry_Name), I, It);
7386 while Present (It.Typ) loop
7387 if Covers (Typ, It.Typ) then
7388 Set_Entity (Selector_Name (Entry_Name), It.Nam);
7389 Set_Etype (Entry_Name, It.Typ);
7391 Generate_Reference (It.Typ, N, ' ');
7394 Get_Next_Interp (I, It);
7399 Resolve_Entry (Entry_Name);
7401 if Nkind (Entry_Name) = N_Selected_Component then
7403 -- Simple entry call
7405 Nam := Entity (Selector_Name (Entry_Name));
7406 Obj := Prefix (Entry_Name);
7407 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
7409 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7411 -- Call to member of entry family
7413 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
7414 Obj := Prefix (Prefix (Entry_Name));
7415 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
7418 -- We cannot in general check the maximum depth of protected entry calls
7419 -- at compile time. But we can tell that any protected entry call at all
7420 -- violates a specified nesting depth of zero.
7422 if Is_Protected_Type (Scope (Nam)) then
7423 Check_Restriction (Max_Entry_Queue_Length, N);
7426 -- Use context type to disambiguate a protected function that can be
7427 -- called without actuals and that returns an array type, and where the
7428 -- argument list may be an indexing of the returned value.
7430 if Ekind (Nam) = E_Function
7431 and then Needs_No_Actuals (Nam)
7432 and then Present (Parameter_Associations (N))
7434 ((Is_Array_Type (Etype (Nam))
7435 and then Covers (Typ, Component_Type (Etype (Nam))))
7437 or else (Is_Access_Type (Etype (Nam))
7438 and then Is_Array_Type (Designated_Type (Etype (Nam)))
7442 Component_Type (Designated_Type (Etype (Nam))))))
7445 Index_Node : Node_Id;
7449 Make_Indexed_Component (Loc,
7451 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
7452 Expressions => Parameter_Associations (N));
7454 -- Since we are correcting a node classification error made by the
7455 -- parser, we call Replace rather than Rewrite.
7457 Replace (N, Index_Node);
7458 Set_Etype (Prefix (N), Etype (Nam));
7460 Resolve_Indexed_Component (N, Typ);
7465 if Ekind_In (Nam, E_Entry, E_Entry_Family)
7466 and then Present (Contract_Wrapper (Nam))
7467 and then Current_Scope /= Contract_Wrapper (Nam)
7470 -- Note the entity being called before rewriting the call, so that
7471 -- it appears used at this point.
7473 Generate_Reference (Nam, Entry_Name, 'r');
7475 -- Rewrite as call to the precondition wrapper, adding the task
7476 -- object to the list of actuals. If the call is to a member of an
7477 -- entry family, include the index as well.
7481 New_Actuals : List_Id;
7484 New_Actuals := New_List (Obj);
7486 if Nkind (Entry_Name) = N_Indexed_Component then
7487 Append_To (New_Actuals,
7488 New_Copy_Tree (First (Expressions (Entry_Name))));
7491 Append_List (Parameter_Associations (N), New_Actuals);
7493 Make_Procedure_Call_Statement (Loc,
7495 New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
7496 Parameter_Associations => New_Actuals);
7497 Rewrite (N, New_Call);
7499 -- Preanalyze and resolve new call. Current procedure is called
7500 -- from Resolve_Call, after which expansion will take place.
7502 Preanalyze_And_Resolve (N);
7507 -- The operation name may have been overloaded. Order the actuals
7508 -- according to the formals of the resolved entity, and set the return
7509 -- type to that of the operation.
7512 Normalize_Actuals (N, Nam, False, Norm_OK);
7513 pragma Assert (Norm_OK);
7514 Set_Etype (N, Etype (Nam));
7516 -- Reset the Is_Overloaded flag, since resolution is now completed
7518 -- Simple entry call
7520 if Nkind (Entry_Name) = N_Selected_Component then
7521 Set_Is_Overloaded (Selector_Name (Entry_Name), False);
7523 -- Call to a member of an entry family
7525 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
7526 Set_Is_Overloaded (Selector_Name (Prefix (Entry_Name)), False);
7530 Resolve_Actuals (N, Nam);
7531 Check_Internal_Protected_Use (N, Nam);
7533 -- Create a call reference to the entry
7535 Generate_Reference (Nam, Entry_Name, 's');
7537 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
7538 Check_Potentially_Blocking_Operation (N);
7541 -- Verify that a procedure call cannot masquerade as an entry
7542 -- call where an entry call is expected.
7544 if Ekind (Nam) = E_Procedure then
7545 if Nkind (Parent (N)) = N_Entry_Call_Alternative
7546 and then N = Entry_Call_Statement (Parent (N))
7548 Error_Msg_N ("entry call required in select statement", N);
7550 elsif Nkind (Parent (N)) = N_Triggering_Alternative
7551 and then N = Triggering_Statement (Parent (N))
7553 Error_Msg_N ("triggering statement cannot be procedure call", N);
7555 elsif Ekind (Scope (Nam)) = E_Task_Type
7556 and then not In_Open_Scopes (Scope (Nam))
7558 Error_Msg_N ("task has no entry with this name", Entry_Name);
7562 -- After resolution, entry calls and protected procedure calls are
7563 -- changed into entry calls, for expansion. The structure of the node
7564 -- does not change, so it can safely be done in place. Protected
7565 -- function calls must keep their structure because they are
7568 if Ekind (Nam) /= E_Function then
7570 -- A protected operation that is not a function may modify the
7571 -- corresponding object, and cannot apply to a constant. If this
7572 -- is an internal call, the prefix is the type itself.
7574 if Is_Protected_Type (Scope (Nam))
7575 and then not Is_Variable (Obj)
7576 and then (not Is_Entity_Name (Obj)
7577 or else not Is_Type (Entity (Obj)))
7580 ("prefix of protected procedure or entry call must be variable",
7584 Actuals := Parameter_Associations (N);
7585 First_Named := First_Named_Actual (N);
7588 Make_Entry_Call_Statement (Loc,
7590 Parameter_Associations => Actuals));
7592 Set_First_Named_Actual (N, First_Named);
7593 Set_Analyzed (N, True);
7595 -- Protected functions can return on the secondary stack, in which
7596 -- case we must trigger the transient scope mechanism.
7598 elsif Expander_Active
7599 and then Requires_Transient_Scope (Etype (Nam))
7601 Establish_Transient_Scope (N, Sec_Stack => True);
7603 end Resolve_Entry_Call;
7605 -------------------------
7606 -- Resolve_Equality_Op --
7607 -------------------------
7609 -- Both arguments must have the same type, and the boolean context does
7610 -- not participate in the resolution. The first pass verifies that the
7611 -- interpretation is not ambiguous, and the type of the left argument is
7612 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7613 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7614 -- though they carry a single (universal) type. Diagnose this case here.
7616 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
7617 L : constant Node_Id := Left_Opnd (N);
7618 R : constant Node_Id := Right_Opnd (N);
7619 T : Entity_Id := Find_Unique_Type (L, R);
7621 procedure Check_If_Expression (Cond : Node_Id);
7622 -- The resolution rule for if expressions requires that each such must
7623 -- have a unique type. This means that if several dependent expressions
7624 -- are of a non-null anonymous access type, and the context does not
7625 -- impose an expected type (as can be the case in an equality operation)
7626 -- the expression must be rejected.
7628 procedure Explain_Redundancy (N : Node_Id);
7629 -- Attempt to explain the nature of a redundant comparison with True. If
7630 -- the expression N is too complex, this routine issues a general error
7633 function Find_Unique_Access_Type return Entity_Id;
7634 -- In the case of allocators and access attributes, the context must
7635 -- provide an indication of the specific access type to be used. If
7636 -- one operand is of such a "generic" access type, check whether there
7637 -- is a specific visible access type that has the same designated type.
7638 -- This is semantically dubious, and of no interest to any real code,
7639 -- but c48008a makes it all worthwhile.
7641 -------------------------
7642 -- Check_If_Expression --
7643 -------------------------
7645 procedure Check_If_Expression (Cond : Node_Id) is
7646 Then_Expr : Node_Id;
7647 Else_Expr : Node_Id;
7650 if Nkind (Cond) = N_If_Expression then
7651 Then_Expr := Next (First (Expressions (Cond)));
7652 Else_Expr := Next (Then_Expr);
7654 if Nkind (Then_Expr) /= N_Null
7655 and then Nkind (Else_Expr) /= N_Null
7657 Error_Msg_N ("cannot determine type of if expression", Cond);
7660 end Check_If_Expression;
7662 ------------------------
7663 -- Explain_Redundancy --
7664 ------------------------
7666 procedure Explain_Redundancy (N : Node_Id) is
7674 -- Strip the operand down to an entity
7677 if Nkind (Val) = N_Selected_Component then
7678 Val := Selector_Name (Val);
7684 -- The construct denotes an entity
7686 if Is_Entity_Name (Val) and then Present (Entity (Val)) then
7687 Val_Id := Entity (Val);
7689 -- Do not generate an error message when the comparison is done
7690 -- against the enumeration literal Standard.True.
7692 if Ekind (Val_Id) /= E_Enumeration_Literal then
7694 -- Build a customized error message
7697 Add_Str_To_Name_Buffer ("?r?");
7699 if Ekind (Val_Id) = E_Component then
7700 Add_Str_To_Name_Buffer ("component ");
7702 elsif Ekind (Val_Id) = E_Constant then
7703 Add_Str_To_Name_Buffer ("constant ");
7705 elsif Ekind (Val_Id) = E_Discriminant then
7706 Add_Str_To_Name_Buffer ("discriminant ");
7708 elsif Is_Formal (Val_Id) then
7709 Add_Str_To_Name_Buffer ("parameter ");
7711 elsif Ekind (Val_Id) = E_Variable then
7712 Add_Str_To_Name_Buffer ("variable ");
7715 Add_Str_To_Name_Buffer ("& is always True!");
7718 Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
7721 -- The construct is too complex to disect, issue a general message
7724 Error_Msg_N ("?r?expression is always True!", Val);
7726 end Explain_Redundancy;
7728 -----------------------------
7729 -- Find_Unique_Access_Type --
7730 -----------------------------
7732 function Find_Unique_Access_Type return Entity_Id is
7738 if Ekind_In (Etype (R), E_Allocator_Type,
7739 E_Access_Attribute_Type)
7741 Acc := Designated_Type (Etype (R));
7743 elsif Ekind_In (Etype (L), E_Allocator_Type,
7744 E_Access_Attribute_Type)
7746 Acc := Designated_Type (Etype (L));
7752 while S /= Standard_Standard loop
7753 E := First_Entity (S);
7754 while Present (E) loop
7756 and then Is_Access_Type (E)
7757 and then Ekind (E) /= E_Allocator_Type
7758 and then Designated_Type (E) = Base_Type (Acc)
7770 end Find_Unique_Access_Type;
7772 -- Start of processing for Resolve_Equality_Op
7775 Set_Etype (N, Base_Type (Typ));
7776 Generate_Reference (T, N, ' ');
7778 if T = Any_Fixed then
7779 T := Unique_Fixed_Point_Type (L);
7782 if T /= Any_Type then
7783 if T = Any_String or else
7784 T = Any_Composite or else
7787 if T = Any_Character then
7788 Ambiguous_Character (L);
7790 Error_Msg_N ("ambiguous operands for equality", N);
7793 Set_Etype (N, Any_Type);
7796 elsif T = Any_Access
7797 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
7799 T := Find_Unique_Access_Type;
7802 Error_Msg_N ("ambiguous operands for equality", N);
7803 Set_Etype (N, Any_Type);
7807 -- If expressions must have a single type, and if the context does
7808 -- not impose one the dependent expressions cannot be anonymous
7811 -- Why no similar processing for case expressions???
7813 elsif Ada_Version >= Ada_2012
7814 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
7815 E_Anonymous_Access_Subprogram_Type)
7816 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
7817 E_Anonymous_Access_Subprogram_Type)
7819 Check_If_Expression (L);
7820 Check_If_Expression (R);
7826 -- In SPARK, equality operators = and /= for array types other than
7827 -- String are only defined when, for each index position, the
7828 -- operands have equal static bounds.
7830 if Is_Array_Type (T) then
7832 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7833 -- operation if not needed.
7835 if Restriction_Check_Required (SPARK_05)
7836 and then Base_Type (T) /= Standard_String
7837 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
7838 and then Etype (L) /= Any_Composite -- or else L in error
7839 and then Etype (R) /= Any_Composite -- or else R in error
7840 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
7842 Check_SPARK_05_Restriction
7843 ("array types should have matching static bounds", N);
7847 -- If the unique type is a class-wide type then it will be expanded
7848 -- into a dispatching call to the predefined primitive. Therefore we
7849 -- check here for potential violation of such restriction.
7851 if Is_Class_Wide_Type (T) then
7852 Check_Restriction (No_Dispatching_Calls, N);
7855 if Warn_On_Redundant_Constructs
7856 and then Comes_From_Source (N)
7857 and then Comes_From_Source (R)
7858 and then Is_Entity_Name (R)
7859 and then Entity (R) = Standard_True
7861 Error_Msg_N -- CODEFIX
7862 ("?r?comparison with True is redundant!", N);
7863 Explain_Redundancy (Original_Node (R));
7866 Check_Unset_Reference (L);
7867 Check_Unset_Reference (R);
7868 Generate_Operator_Reference (N, T);
7869 Check_Low_Bound_Tested (N);
7871 -- If this is an inequality, it may be the implicit inequality
7872 -- created for a user-defined operation, in which case the corres-
7873 -- ponding equality operation is not intrinsic, and the operation
7874 -- cannot be constant-folded. Else fold.
7876 if Nkind (N) = N_Op_Eq
7877 or else Comes_From_Source (Entity (N))
7878 or else Ekind (Entity (N)) = E_Operator
7879 or else Is_Intrinsic_Subprogram
7880 (Corresponding_Equality (Entity (N)))
7882 Analyze_Dimension (N);
7883 Eval_Relational_Op (N);
7885 elsif Nkind (N) = N_Op_Ne
7886 and then Is_Abstract_Subprogram (Entity (N))
7888 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
7891 -- Ada 2005: If one operand is an anonymous access type, convert the
7892 -- other operand to it, to ensure that the underlying types match in
7893 -- the back-end. Same for access_to_subprogram, and the conversion
7894 -- verifies that the types are subtype conformant.
7896 -- We apply the same conversion in the case one of the operands is a
7897 -- private subtype of the type of the other.
7899 -- Why the Expander_Active test here ???
7903 (Ekind_In (T, E_Anonymous_Access_Type,
7904 E_Anonymous_Access_Subprogram_Type)
7905 or else Is_Private_Type (T))
7907 if Etype (L) /= T then
7909 Make_Unchecked_Type_Conversion (Sloc (L),
7910 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
7911 Expression => Relocate_Node (L)));
7912 Analyze_And_Resolve (L, T);
7915 if (Etype (R)) /= T then
7917 Make_Unchecked_Type_Conversion (Sloc (R),
7918 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
7919 Expression => Relocate_Node (R)));
7920 Analyze_And_Resolve (R, T);
7924 end Resolve_Equality_Op;
7926 ----------------------------------
7927 -- Resolve_Explicit_Dereference --
7928 ----------------------------------
7930 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
7931 Loc : constant Source_Ptr := Sloc (N);
7933 P : constant Node_Id := Prefix (N);
7936 -- The candidate prefix type, if overloaded
7942 Check_Fully_Declared_Prefix (Typ, P);
7945 -- A useful optimization: check whether the dereference denotes an
7946 -- element of a container, and if so rewrite it as a call to the
7947 -- corresponding Element function.
7949 -- Disabled for now, on advice of ARG. A more restricted form of the
7950 -- predicate might be acceptable ???
7952 -- if Is_Container_Element (N) then
7956 if Is_Overloaded (P) then
7958 -- Use the context type to select the prefix that has the correct
7959 -- designated type. Keep the first match, which will be the inner-
7962 Get_First_Interp (P, I, It);
7964 while Present (It.Typ) loop
7965 if Is_Access_Type (It.Typ)
7966 and then Covers (Typ, Designated_Type (It.Typ))
7972 -- Remove access types that do not match, but preserve access
7973 -- to subprogram interpretations, in case a further dereference
7974 -- is needed (see below).
7976 elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
7980 Get_Next_Interp (I, It);
7983 if Present (P_Typ) then
7985 Set_Etype (N, Designated_Type (P_Typ));
7988 -- If no interpretation covers the designated type of the prefix,
7989 -- this is the pathological case where not all implementations of
7990 -- the prefix allow the interpretation of the node as a call. Now
7991 -- that the expected type is known, Remove other interpretations
7992 -- from prefix, rewrite it as a call, and resolve again, so that
7993 -- the proper call node is generated.
7995 Get_First_Interp (P, I, It);
7996 while Present (It.Typ) loop
7997 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
8001 Get_Next_Interp (I, It);
8005 Make_Function_Call (Loc,
8007 Make_Explicit_Dereference (Loc,
8009 Parameter_Associations => New_List);
8011 Save_Interps (N, New_N);
8013 Analyze_And_Resolve (N, Typ);
8017 -- If not overloaded, resolve P with its own type
8023 -- If the prefix might be null, add an access check
8025 if Is_Access_Type (Etype (P))
8026 and then not Can_Never_Be_Null (Etype (P))
8028 Apply_Access_Check (N);
8031 -- If the designated type is a packed unconstrained array type, and the
8032 -- explicit dereference is not in the context of an attribute reference,
8033 -- then we must compute and set the actual subtype, since it is needed
8034 -- by Gigi. The reason we exclude the attribute case is that this is
8035 -- handled fine by Gigi, and in fact we use such attributes to build the
8036 -- actual subtype. We also exclude generated code (which builds actual
8037 -- subtypes directly if they are needed).
8039 if Is_Array_Type (Etype (N))
8040 and then Is_Packed (Etype (N))
8041 and then not Is_Constrained (Etype (N))
8042 and then Nkind (Parent (N)) /= N_Attribute_Reference
8043 and then Comes_From_Source (N)
8045 Set_Etype (N, Get_Actual_Subtype (N));
8048 Analyze_Dimension (N);
8050 -- Note: No Eval processing is required for an explicit dereference,
8051 -- because such a name can never be static.
8053 end Resolve_Explicit_Dereference;
8055 -------------------------------------
8056 -- Resolve_Expression_With_Actions --
8057 -------------------------------------
8059 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
8063 -- If N has no actions, and its expression has been constant folded,
8064 -- then rewrite N as just its expression. Note, we can't do this in
8065 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8066 -- Expression (N) to be expanded again.
8068 if Is_Empty_List (Actions (N))
8069 and then Compile_Time_Known_Value (Expression (N))
8071 Rewrite (N, Expression (N));
8073 end Resolve_Expression_With_Actions;
8075 ----------------------------------
8076 -- Resolve_Generalized_Indexing --
8077 ----------------------------------
8079 procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
8080 Indexing : constant Node_Id := Generalized_Indexing (N);
8086 -- In ASIS mode, propagate the information about the indexes back to
8087 -- to the original indexing node. The generalized indexing is either
8088 -- a function call, or a dereference of one. The actuals include the
8089 -- prefix of the original node, which is the container expression.
8092 Resolve (Indexing, Typ);
8093 Set_Etype (N, Etype (Indexing));
8094 Set_Is_Overloaded (N, False);
8097 while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
8099 Call := Prefix (Call);
8102 if Nkind (Call) = N_Function_Call then
8103 Indexes := Parameter_Associations (Call);
8104 Pref := Remove_Head (Indexes);
8105 Set_Expressions (N, Indexes);
8107 -- If expression is to be reanalyzed, reset Generalized_Indexing
8108 -- to recreate call node, as is the case when the expression is
8109 -- part of an expression function.
8111 if In_Spec_Expression then
8112 Set_Generalized_Indexing (N, Empty);
8115 Set_Prefix (N, Pref);
8119 Rewrite (N, Indexing);
8122 end Resolve_Generalized_Indexing;
8124 ---------------------------
8125 -- Resolve_If_Expression --
8126 ---------------------------
8128 procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
8129 Condition : constant Node_Id := First (Expressions (N));
8130 Then_Expr : constant Node_Id := Next (Condition);
8131 Else_Expr : Node_Id := Next (Then_Expr);
8132 Else_Typ : Entity_Id;
8133 Then_Typ : Entity_Id;
8136 Resolve (Condition, Any_Boolean);
8137 Resolve (Then_Expr, Typ);
8138 Then_Typ := Etype (Then_Expr);
8140 -- When the "then" expression is of a scalar subtype different from the
8141 -- result subtype, then insert a conversion to ensure the generation of
8142 -- a constraint check. The same is done for the else part below, again
8143 -- comparing subtypes rather than base types.
8145 if Is_Scalar_Type (Then_Typ)
8146 and then Then_Typ /= Typ
8148 Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
8149 Analyze_And_Resolve (Then_Expr, Typ);
8152 -- If ELSE expression present, just resolve using the determined type
8153 -- If type is universal, resolve to any member of the class.
8155 if Present (Else_Expr) then
8156 if Typ = Universal_Integer then
8157 Resolve (Else_Expr, Any_Integer);
8159 elsif Typ = Universal_Real then
8160 Resolve (Else_Expr, Any_Real);
8163 Resolve (Else_Expr, Typ);
8166 Else_Typ := Etype (Else_Expr);
8168 if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
8169 Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
8170 Analyze_And_Resolve (Else_Expr, Typ);
8172 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8173 -- dynamically tagged must be known statically.
8175 elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
8176 if Is_Dynamically_Tagged (Then_Expr) /=
8177 Is_Dynamically_Tagged (Else_Expr)
8179 Error_Msg_N ("all or none of the dependent expressions "
8180 & "can be dynamically tagged", N);
8184 -- If no ELSE expression is present, root type must be Standard.Boolean
8185 -- and we provide a Standard.True result converted to the appropriate
8186 -- Boolean type (in case it is a derived boolean type).
8188 elsif Root_Type (Typ) = Standard_Boolean then
8190 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
8191 Analyze_And_Resolve (Else_Expr, Typ);
8192 Append_To (Expressions (N), Else_Expr);
8195 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
8196 Append_To (Expressions (N), Error);
8200 Eval_If_Expression (N);
8201 end Resolve_If_Expression;
8203 -------------------------------
8204 -- Resolve_Indexed_Component --
8205 -------------------------------
8207 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
8208 Name : constant Node_Id := Prefix (N);
8210 Array_Type : Entity_Id := Empty; -- to prevent junk warning
8214 if Present (Generalized_Indexing (N)) then
8215 Resolve_Generalized_Indexing (N, Typ);
8219 if Is_Overloaded (Name) then
8221 -- Use the context type to select the prefix that yields the correct
8227 I1 : Interp_Index := 0;
8228 P : constant Node_Id := Prefix (N);
8229 Found : Boolean := False;
8232 Get_First_Interp (P, I, It);
8233 while Present (It.Typ) loop
8234 if (Is_Array_Type (It.Typ)
8235 and then Covers (Typ, Component_Type (It.Typ)))
8236 or else (Is_Access_Type (It.Typ)
8237 and then Is_Array_Type (Designated_Type (It.Typ))
8241 Component_Type (Designated_Type (It.Typ))))
8244 It := Disambiguate (P, I1, I, Any_Type);
8246 if It = No_Interp then
8247 Error_Msg_N ("ambiguous prefix for indexing", N);
8253 Array_Type := It.Typ;
8259 Array_Type := It.Typ;
8264 Get_Next_Interp (I, It);
8269 Array_Type := Etype (Name);
8272 Resolve (Name, Array_Type);
8273 Array_Type := Get_Actual_Subtype_If_Available (Name);
8275 -- If prefix is access type, dereference to get real array type.
8276 -- Note: we do not apply an access check because the expander always
8277 -- introduces an explicit dereference, and the check will happen there.
8279 if Is_Access_Type (Array_Type) then
8280 Array_Type := Designated_Type (Array_Type);
8283 -- If name was overloaded, set component type correctly now
8284 -- If a misplaced call to an entry family (which has no index types)
8285 -- return. Error will be diagnosed from calling context.
8287 if Is_Array_Type (Array_Type) then
8288 Set_Etype (N, Component_Type (Array_Type));
8293 Index := First_Index (Array_Type);
8294 Expr := First (Expressions (N));
8296 -- The prefix may have resolved to a string literal, in which case its
8297 -- etype has a special representation. This is only possible currently
8298 -- if the prefix is a static concatenation, written in functional
8301 if Ekind (Array_Type) = E_String_Literal_Subtype then
8302 Resolve (Expr, Standard_Positive);
8305 while Present (Index) and Present (Expr) loop
8306 Resolve (Expr, Etype (Index));
8307 Check_Unset_Reference (Expr);
8309 if Is_Scalar_Type (Etype (Expr)) then
8310 Apply_Scalar_Range_Check (Expr, Etype (Index));
8312 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
8320 Analyze_Dimension (N);
8322 -- Do not generate the warning on suspicious index if we are analyzing
8323 -- package Ada.Tags; otherwise we will report the warning with the
8324 -- Prims_Ptr field of the dispatch table.
8326 if Scope (Etype (Prefix (N))) = Standard_Standard
8328 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
8331 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
8332 Eval_Indexed_Component (N);
8335 -- If the array type is atomic, and the component is not atomic, then
8336 -- this is worth a warning, since we have a situation where the access
8337 -- to the component may cause extra read/writes of the atomic array
8338 -- object, or partial word accesses, which could be unexpected.
8340 if Nkind (N) = N_Indexed_Component
8341 and then Is_Atomic_Ref_With_Address (N)
8342 and then not (Has_Atomic_Components (Array_Type)
8343 or else (Is_Entity_Name (Prefix (N))
8344 and then Has_Atomic_Components
8345 (Entity (Prefix (N)))))
8346 and then not Is_Atomic (Component_Type (Array_Type))
8349 ("??access to non-atomic component of atomic array", Prefix (N));
8351 ("??\may cause unexpected accesses to atomic object", Prefix (N));
8353 end Resolve_Indexed_Component;
8355 -----------------------------
8356 -- Resolve_Integer_Literal --
8357 -----------------------------
8359 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
8362 Eval_Integer_Literal (N);
8363 end Resolve_Integer_Literal;
8365 --------------------------------
8366 -- Resolve_Intrinsic_Operator --
8367 --------------------------------
8369 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
8370 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8375 function Convert_Operand (Opnd : Node_Id) return Node_Id;
8376 -- If the operand is a literal, it cannot be the expression in a
8377 -- conversion. Use a qualified expression instead.
8379 ---------------------
8380 -- Convert_Operand --
8381 ---------------------
8383 function Convert_Operand (Opnd : Node_Id) return Node_Id is
8384 Loc : constant Source_Ptr := Sloc (Opnd);
8388 if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
8390 Make_Qualified_Expression (Loc,
8391 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
8392 Expression => Relocate_Node (Opnd));
8396 Res := Unchecked_Convert_To (Btyp, Opnd);
8400 end Convert_Operand;
8402 -- Start of processing for Resolve_Intrinsic_Operator
8405 -- We must preserve the original entity in a generic setting, so that
8406 -- the legality of the operation can be verified in an instance.
8408 if not Expander_Active then
8413 while Scope (Op) /= Standard_Standard loop
8415 pragma Assert (Present (Op));
8419 Set_Is_Overloaded (N, False);
8421 -- If the result or operand types are private, rewrite with unchecked
8422 -- conversions on the operands and the result, to expose the proper
8423 -- underlying numeric type.
8425 if Is_Private_Type (Typ)
8426 or else Is_Private_Type (Etype (Left_Opnd (N)))
8427 or else Is_Private_Type (Etype (Right_Opnd (N)))
8429 Arg1 := Convert_Operand (Left_Opnd (N));
8431 if Nkind (N) = N_Op_Expon then
8432 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
8434 Arg2 := Convert_Operand (Right_Opnd (N));
8437 if Nkind (Arg1) = N_Type_Conversion then
8438 Save_Interps (Left_Opnd (N), Expression (Arg1));
8441 if Nkind (Arg2) = N_Type_Conversion then
8442 Save_Interps (Right_Opnd (N), Expression (Arg2));
8445 Set_Left_Opnd (N, Arg1);
8446 Set_Right_Opnd (N, Arg2);
8448 Set_Etype (N, Btyp);
8449 Rewrite (N, Unchecked_Convert_To (Typ, N));
8452 elsif Typ /= Etype (Left_Opnd (N))
8453 or else Typ /= Etype (Right_Opnd (N))
8455 -- Add explicit conversion where needed, and save interpretations in
8456 -- case operands are overloaded.
8458 Arg1 := Convert_To (Typ, Left_Opnd (N));
8459 Arg2 := Convert_To (Typ, Right_Opnd (N));
8461 if Nkind (Arg1) = N_Type_Conversion then
8462 Save_Interps (Left_Opnd (N), Expression (Arg1));
8464 Save_Interps (Left_Opnd (N), Arg1);
8467 if Nkind (Arg2) = N_Type_Conversion then
8468 Save_Interps (Right_Opnd (N), Expression (Arg2));
8470 Save_Interps (Right_Opnd (N), Arg2);
8473 Rewrite (Left_Opnd (N), Arg1);
8474 Rewrite (Right_Opnd (N), Arg2);
8477 Resolve_Arithmetic_Op (N, Typ);
8480 Resolve_Arithmetic_Op (N, Typ);
8482 end Resolve_Intrinsic_Operator;
8484 --------------------------------------
8485 -- Resolve_Intrinsic_Unary_Operator --
8486 --------------------------------------
8488 procedure Resolve_Intrinsic_Unary_Operator
8492 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
8498 while Scope (Op) /= Standard_Standard loop
8500 pragma Assert (Present (Op));
8505 if Is_Private_Type (Typ) then
8506 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
8507 Save_Interps (Right_Opnd (N), Expression (Arg2));
8509 Set_Right_Opnd (N, Arg2);
8511 Set_Etype (N, Btyp);
8512 Rewrite (N, Unchecked_Convert_To (Typ, N));
8516 Resolve_Unary_Op (N, Typ);
8518 end Resolve_Intrinsic_Unary_Operator;
8520 ------------------------
8521 -- Resolve_Logical_Op --
8522 ------------------------
8524 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
8528 Check_No_Direct_Boolean_Operators (N);
8530 -- Predefined operations on scalar types yield the base type. On the
8531 -- other hand, logical operations on arrays yield the type of the
8532 -- arguments (and the context).
8534 if Is_Array_Type (Typ) then
8537 B_Typ := Base_Type (Typ);
8540 -- The following test is required because the operands of the operation
8541 -- may be literals, in which case the resulting type appears to be
8542 -- compatible with a signed integer type, when in fact it is compatible
8543 -- only with modular types. If the context itself is universal, the
8544 -- operation is illegal.
8546 if not Valid_Boolean_Arg (Typ) then
8547 Error_Msg_N ("invalid context for logical operation", N);
8548 Set_Etype (N, Any_Type);
8551 elsif Typ = Any_Modular then
8553 ("no modular type available in this context", N);
8554 Set_Etype (N, Any_Type);
8557 elsif Is_Modular_Integer_Type (Typ)
8558 and then Etype (Left_Opnd (N)) = Universal_Integer
8559 and then Etype (Right_Opnd (N)) = Universal_Integer
8561 Check_For_Visible_Operator (N, B_Typ);
8564 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8565 -- is active and the result type is standard Boolean (do not mess with
8566 -- ops that return a nonstandard Boolean type, because something strange
8569 -- Note: you might expect this replacement to be done during expansion,
8570 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8571 -- is used, no part of the right operand of an "and" or "or" operator
8572 -- should be executed if the left operand would short-circuit the
8573 -- evaluation of the corresponding "and then" or "or else". If we left
8574 -- the replacement to expansion time, then run-time checks associated
8575 -- with such operands would be evaluated unconditionally, due to being
8576 -- before the condition prior to the rewriting as short-circuit forms
8577 -- during expansion.
8579 if Short_Circuit_And_Or
8580 and then B_Typ = Standard_Boolean
8581 and then Nkind_In (N, N_Op_And, N_Op_Or)
8583 -- Mark the corresponding putative SCO operator as truly a logical
8584 -- (and short-circuit) operator.
8586 if Generate_SCO and then Comes_From_Source (N) then
8587 Set_SCO_Logical_Operator (N);
8590 if Nkind (N) = N_Op_And then
8592 Make_And_Then (Sloc (N),
8593 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8594 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8595 Analyze_And_Resolve (N, B_Typ);
8597 -- Case of OR changed to OR ELSE
8601 Make_Or_Else (Sloc (N),
8602 Left_Opnd => Relocate_Node (Left_Opnd (N)),
8603 Right_Opnd => Relocate_Node (Right_Opnd (N))));
8604 Analyze_And_Resolve (N, B_Typ);
8607 -- Return now, since analysis of the rewritten ops will take care of
8608 -- other reference bookkeeping and expression folding.
8613 Resolve (Left_Opnd (N), B_Typ);
8614 Resolve (Right_Opnd (N), B_Typ);
8616 Check_Unset_Reference (Left_Opnd (N));
8617 Check_Unset_Reference (Right_Opnd (N));
8619 Set_Etype (N, B_Typ);
8620 Generate_Operator_Reference (N, B_Typ);
8621 Eval_Logical_Op (N);
8623 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8624 -- only when both operands have same static lower and higher bounds. Of
8625 -- course the types have to match, so only check if operands are
8626 -- compatible and the node itself has no errors.
8628 if Is_Array_Type (B_Typ)
8629 and then Nkind (N) in N_Binary_Op
8632 Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
8633 Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
8636 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8637 -- operation if not needed.
8639 if Restriction_Check_Required (SPARK_05)
8640 and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
8641 and then Left_Typ /= Any_Composite -- or Left_Opnd in error
8642 and then Right_Typ /= Any_Composite -- or Right_Opnd in error
8643 and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
8645 Check_SPARK_05_Restriction
8646 ("array types should have matching static bounds", N);
8650 end Resolve_Logical_Op;
8652 ---------------------------
8653 -- Resolve_Membership_Op --
8654 ---------------------------
8656 -- The context can only be a boolean type, and does not determine the
8657 -- arguments. Arguments should be unambiguous, but the preference rule for
8658 -- universal types applies.
8660 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
8661 pragma Warnings (Off, Typ);
8663 L : constant Node_Id := Left_Opnd (N);
8664 R : constant Node_Id := Right_Opnd (N);
8667 procedure Resolve_Set_Membership;
8668 -- Analysis has determined a unique type for the left operand. Use it to
8669 -- resolve the disjuncts.
8671 ----------------------------
8672 -- Resolve_Set_Membership --
8673 ----------------------------
8675 procedure Resolve_Set_Membership is
8680 -- If the left operand is overloaded, find type compatible with not
8681 -- overloaded alternative of the right operand.
8683 if Is_Overloaded (L) then
8685 Alt := First (Alternatives (N));
8686 while Present (Alt) loop
8687 if not Is_Overloaded (Alt) then
8688 Ltyp := Intersect_Types (L, Alt);
8695 -- Unclear how to resolve expression if all alternatives are also
8699 Error_Msg_N ("ambiguous expression", N);
8708 Alt := First (Alternatives (N));
8709 while Present (Alt) loop
8711 -- Alternative is an expression, a range
8712 -- or a subtype mark.
8714 if not Is_Entity_Name (Alt)
8715 or else not Is_Type (Entity (Alt))
8717 Resolve (Alt, Ltyp);
8723 -- Check for duplicates for discrete case
8725 if Is_Discrete_Type (Ltyp) then
8732 Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
8736 -- Loop checking duplicates. This is quadratic, but giant sets
8737 -- are unlikely in this context so it's a reasonable choice.
8740 Alt := First (Alternatives (N));
8741 while Present (Alt) loop
8742 if Is_OK_Static_Expression (Alt)
8743 and then (Nkind_In (Alt, N_Integer_Literal,
8744 N_Character_Literal)
8745 or else Nkind (Alt) in N_Has_Entity)
8748 Alts (Nalts) := (Alt, Expr_Value (Alt));
8750 for J in 1 .. Nalts - 1 loop
8751 if Alts (J).Val = Alts (Nalts).Val then
8752 Error_Msg_Sloc := Sloc (Alts (J).Alt);
8753 Error_Msg_N ("duplicate of value given#??", Alt);
8762 end Resolve_Set_Membership;
8764 -- Start of processing for Resolve_Membership_Op
8767 if L = Error or else R = Error then
8771 if Present (Alternatives (N)) then
8772 Resolve_Set_Membership;
8775 elsif not Is_Overloaded (R)
8777 (Etype (R) = Universal_Integer
8779 Etype (R) = Universal_Real)
8780 and then Is_Overloaded (L)
8784 -- Ada 2005 (AI-251): Support the following case:
8786 -- type I is interface;
8787 -- type T is tagged ...
8789 -- function Test (O : I'Class) is
8791 -- return O in T'Class.
8794 -- In this case we have nothing else to do. The membership test will be
8795 -- done at run time.
8797 elsif Ada_Version >= Ada_2005
8798 and then Is_Class_Wide_Type (Etype (L))
8799 and then Is_Interface (Etype (L))
8800 and then Is_Class_Wide_Type (Etype (R))
8801 and then not Is_Interface (Etype (R))
8805 T := Intersect_Types (L, R);
8808 -- If mixed-mode operations are present and operands are all literal,
8809 -- the only interpretation involves Duration, which is probably not
8810 -- the intention of the programmer.
8812 if T = Any_Fixed then
8813 T := Unique_Fixed_Point_Type (N);
8815 if T = Any_Type then
8821 Check_Unset_Reference (L);
8823 if Nkind (R) = N_Range
8824 and then not Is_Scalar_Type (T)
8826 Error_Msg_N ("scalar type required for range", R);
8829 if Is_Entity_Name (R) then
8830 Freeze_Expression (R);
8833 Check_Unset_Reference (R);
8836 -- Here after resolving membership operation
8840 Eval_Membership_Op (N);
8841 end Resolve_Membership_Op;
8847 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
8848 Loc : constant Source_Ptr := Sloc (N);
8851 -- Handle restriction against anonymous null access values This
8852 -- restriction can be turned off using -gnatdj.
8854 -- Ada 2005 (AI-231): Remove restriction
8856 if Ada_Version < Ada_2005
8857 and then not Debug_Flag_J
8858 and then Ekind (Typ) = E_Anonymous_Access_Type
8859 and then Comes_From_Source (N)
8861 -- In the common case of a call which uses an explicitly null value
8862 -- for an access parameter, give specialized error message.
8864 if Nkind (Parent (N)) in N_Subprogram_Call then
8866 ("null is not allowed as argument for an access parameter", N);
8868 -- Standard message for all other cases (are there any?)
8872 ("null cannot be of an anonymous access type", N);
8876 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8877 -- assignment to a null-excluding object
8879 if Ada_Version >= Ada_2005
8880 and then Can_Never_Be_Null (Typ)
8881 and then Nkind (Parent (N)) = N_Assignment_Statement
8883 if not Inside_Init_Proc then
8885 (Compile_Time_Constraint_Error (N,
8886 "(Ada 2005) null not allowed in null-excluding objects??"),
8887 Make_Raise_Constraint_Error (Loc,
8888 Reason => CE_Access_Check_Failed));
8891 Make_Raise_Constraint_Error (Loc,
8892 Reason => CE_Access_Check_Failed));
8896 -- In a distributed context, null for a remote access to subprogram may
8897 -- need to be replaced with a special record aggregate. In this case,
8898 -- return after having done the transformation.
8900 if (Ekind (Typ) = E_Record_Type
8901 or else Is_Remote_Access_To_Subprogram_Type (Typ))
8902 and then Remote_AST_Null_Value (N, Typ)
8907 -- The null literal takes its type from the context
8912 -----------------------
8913 -- Resolve_Op_Concat --
8914 -----------------------
8916 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
8918 -- We wish to avoid deep recursion, because concatenations are often
8919 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8920 -- operands nonrecursively until we find something that is not a simple
8921 -- concatenation (A in this case). We resolve that, and then walk back
8922 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8923 -- to do the rest of the work at each level. The Parent pointers allow
8924 -- us to avoid recursion, and thus avoid running out of memory. See also
8925 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8931 -- The following code is equivalent to:
8933 -- Resolve_Op_Concat_First (NN, Typ);
8934 -- Resolve_Op_Concat_Arg (N, ...);
8935 -- Resolve_Op_Concat_Rest (N, Typ);
8937 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8938 -- operand is a concatenation.
8940 -- Walk down left operands
8943 Resolve_Op_Concat_First (NN, Typ);
8944 Op1 := Left_Opnd (NN);
8945 exit when not (Nkind (Op1) = N_Op_Concat
8946 and then not Is_Array_Type (Component_Type (Typ))
8947 and then Entity (Op1) = Entity (NN));
8951 -- Now (given the above example) NN is A&B and Op1 is A
8953 -- First resolve Op1 ...
8955 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
8957 -- ... then walk NN back up until we reach N (where we started), calling
8958 -- Resolve_Op_Concat_Rest along the way.
8961 Resolve_Op_Concat_Rest (NN, Typ);
8966 if Base_Type (Etype (N)) /= Standard_String then
8967 Check_SPARK_05_Restriction
8968 ("result of concatenation should have type String", N);
8970 end Resolve_Op_Concat;
8972 ---------------------------
8973 -- Resolve_Op_Concat_Arg --
8974 ---------------------------
8976 procedure Resolve_Op_Concat_Arg
8982 Btyp : constant Entity_Id := Base_Type (Typ);
8983 Ctyp : constant Entity_Id := Component_Type (Typ);
8988 or else (not Is_Overloaded (Arg)
8989 and then Etype (Arg) /= Any_Composite
8990 and then Covers (Ctyp, Etype (Arg)))
8992 Resolve (Arg, Ctyp);
8994 Resolve (Arg, Btyp);
8997 -- If both Array & Array and Array & Component are visible, there is a
8998 -- potential ambiguity that must be reported.
9000 elsif Has_Compatible_Type (Arg, Ctyp) then
9001 if Nkind (Arg) = N_Aggregate
9002 and then Is_Composite_Type (Ctyp)
9004 if Is_Private_Type (Ctyp) then
9005 Resolve (Arg, Btyp);
9007 -- If the operation is user-defined and not overloaded use its
9008 -- profile. The operation may be a renaming, in which case it has
9009 -- been rewritten, and we want the original profile.
9011 elsif not Is_Overloaded (N)
9012 and then Comes_From_Source (Entity (Original_Node (N)))
9013 and then Ekind (Entity (Original_Node (N))) = E_Function
9017 (Next_Formal (First_Formal (Entity (Original_Node (N))))));
9020 -- Otherwise an aggregate may match both the array type and the
9024 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
9025 Set_Etype (Arg, Any_Type);
9029 if Is_Overloaded (Arg)
9030 and then Has_Compatible_Type (Arg, Typ)
9031 and then Etype (Arg) /= Any_Type
9039 Get_First_Interp (Arg, I, It);
9041 Get_Next_Interp (I, It);
9043 -- Special-case the error message when the overloading is
9044 -- caused by a function that yields an array and can be
9045 -- called without parameters.
9047 if It.Nam = Func then
9048 Error_Msg_Sloc := Sloc (Func);
9049 Error_Msg_N ("ambiguous call to function#", Arg);
9051 ("\\interpretation as call yields&", Arg, Typ);
9053 ("\\interpretation as indexing of call yields&",
9054 Arg, Component_Type (Typ));
9057 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
9059 Get_First_Interp (Arg, I, It);
9060 while Present (It.Nam) loop
9061 Error_Msg_Sloc := Sloc (It.Nam);
9063 if Base_Type (It.Typ) = Btyp
9065 Base_Type (It.Typ) = Base_Type (Ctyp)
9067 Error_Msg_N -- CODEFIX
9068 ("\\possible interpretation#", Arg);
9071 Get_Next_Interp (I, It);
9077 Resolve (Arg, Component_Type (Typ));
9079 if Nkind (Arg) = N_String_Literal then
9080 Set_Etype (Arg, Component_Type (Typ));
9083 if Arg = Left_Opnd (N) then
9084 Set_Is_Component_Left_Opnd (N);
9086 Set_Is_Component_Right_Opnd (N);
9091 Resolve (Arg, Btyp);
9094 -- Concatenation is restricted in SPARK: each operand must be either a
9095 -- string literal, the name of a string constant, a static character or
9096 -- string expression, or another concatenation. Arg cannot be a
9097 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9098 -- separately on each final operand, past concatenation operations.
9100 if Is_Character_Type (Etype (Arg)) then
9101 if not Is_OK_Static_Expression (Arg) then
9102 Check_SPARK_05_Restriction
9103 ("character operand for concatenation should be static", Arg);
9106 elsif Is_String_Type (Etype (Arg)) then
9107 if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
9108 and then Is_Constant_Object (Entity (Arg)))
9109 and then not Is_OK_Static_Expression (Arg)
9111 Check_SPARK_05_Restriction
9112 ("string operand for concatenation should be static", Arg);
9115 -- Do not issue error on an operand that is neither a character nor a
9116 -- string, as the error is issued in Resolve_Op_Concat.
9122 Check_Unset_Reference (Arg);
9123 end Resolve_Op_Concat_Arg;
9125 -----------------------------
9126 -- Resolve_Op_Concat_First --
9127 -----------------------------
9129 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
9130 Btyp : constant Entity_Id := Base_Type (Typ);
9131 Op1 : constant Node_Id := Left_Opnd (N);
9132 Op2 : constant Node_Id := Right_Opnd (N);
9135 -- The parser folds an enormous sequence of concatenations of string
9136 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9137 -- in the right operand. If the expression resolves to a predefined "&"
9138 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9139 -- we give an error. See P_Simple_Expression in Par.Ch4.
9141 if Nkind (Op2) = N_String_Literal
9142 and then Is_Folded_In_Parser (Op2)
9143 and then Ekind (Entity (N)) = E_Function
9145 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
9146 and then String_Length (Strval (Op1)) = 0);
9147 Error_Msg_N ("too many user-defined concatenations", N);
9151 Set_Etype (N, Btyp);
9153 if Is_Limited_Composite (Btyp) then
9154 Error_Msg_N ("concatenation not available for limited array", N);
9155 Explain_Limited_Type (Btyp, N);
9157 end Resolve_Op_Concat_First;
9159 ----------------------------
9160 -- Resolve_Op_Concat_Rest --
9161 ----------------------------
9163 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
9164 Op1 : constant Node_Id := Left_Opnd (N);
9165 Op2 : constant Node_Id := Right_Opnd (N);
9168 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
9170 Generate_Operator_Reference (N, Typ);
9172 if Is_String_Type (Typ) then
9173 Eval_Concatenation (N);
9176 -- If this is not a static concatenation, but the result is a string
9177 -- type (and not an array of strings) ensure that static string operands
9178 -- have their subtypes properly constructed.
9180 if Nkind (N) /= N_String_Literal
9181 and then Is_Character_Type (Component_Type (Typ))
9183 Set_String_Literal_Subtype (Op1, Typ);
9184 Set_String_Literal_Subtype (Op2, Typ);
9186 end Resolve_Op_Concat_Rest;
9188 ----------------------
9189 -- Resolve_Op_Expon --
9190 ----------------------
9192 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
9193 B_Typ : constant Entity_Id := Base_Type (Typ);
9196 -- Catch attempts to do fixed-point exponentiation with universal
9197 -- operands, which is a case where the illegality is not caught during
9198 -- normal operator analysis. This is not done in preanalysis mode
9199 -- since the tree is not fully decorated during preanalysis.
9201 if Full_Analysis then
9202 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
9203 Error_Msg_N ("exponentiation not available for fixed point", N);
9206 elsif Nkind (Parent (N)) in N_Op
9207 and then Is_Fixed_Point_Type (Etype (Parent (N)))
9208 and then Etype (N) = Universal_Real
9209 and then Comes_From_Source (N)
9211 Error_Msg_N ("exponentiation not available for fixed point", N);
9216 if Comes_From_Source (N)
9217 and then Ekind (Entity (N)) = E_Function
9218 and then Is_Imported (Entity (N))
9219 and then Is_Intrinsic_Subprogram (Entity (N))
9221 Resolve_Intrinsic_Operator (N, Typ);
9225 if Etype (Left_Opnd (N)) = Universal_Integer
9226 or else Etype (Left_Opnd (N)) = Universal_Real
9228 Check_For_Visible_Operator (N, B_Typ);
9231 -- We do the resolution using the base type, because intermediate values
9232 -- in expressions are always of the base type, not a subtype of it.
9234 Resolve (Left_Opnd (N), B_Typ);
9235 Resolve (Right_Opnd (N), Standard_Integer);
9237 -- For integer types, right argument must be in Natural range
9239 if Is_Integer_Type (Typ) then
9240 Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
9243 Check_Unset_Reference (Left_Opnd (N));
9244 Check_Unset_Reference (Right_Opnd (N));
9246 Set_Etype (N, B_Typ);
9247 Generate_Operator_Reference (N, B_Typ);
9249 Analyze_Dimension (N);
9251 if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
9252 -- Evaluate the exponentiation operator for dimensioned type
9254 Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
9259 -- Set overflow checking bit. Much cleverer code needed here eventually
9260 -- and perhaps the Resolve routines should be separated for the various
9261 -- arithmetic operations, since they will need different processing. ???
9263 if Nkind (N) in N_Op then
9264 if not Overflow_Checks_Suppressed (Etype (N)) then
9265 Enable_Overflow_Check (N);
9268 end Resolve_Op_Expon;
9270 --------------------
9271 -- Resolve_Op_Not --
9272 --------------------
9274 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
9277 function Parent_Is_Boolean return Boolean;
9278 -- This function determines if the parent node is a boolean operator or
9279 -- operation (comparison op, membership test, or short circuit form) and
9280 -- the not in question is the left operand of this operation. Note that
9281 -- if the not is in parens, then false is returned.
9283 -----------------------
9284 -- Parent_Is_Boolean --
9285 -----------------------
9287 function Parent_Is_Boolean return Boolean is
9289 if Paren_Count (N) /= 0 then
9293 case Nkind (Parent (N)) is
9308 return Left_Opnd (Parent (N)) = N;
9314 end Parent_Is_Boolean;
9316 -- Start of processing for Resolve_Op_Not
9319 -- Predefined operations on scalar types yield the base type. On the
9320 -- other hand, logical operations on arrays yield the type of the
9321 -- arguments (and the context).
9323 if Is_Array_Type (Typ) then
9326 B_Typ := Base_Type (Typ);
9329 -- Straightforward case of incorrect arguments
9331 if not Valid_Boolean_Arg (Typ) then
9332 Error_Msg_N ("invalid operand type for operator&", N);
9333 Set_Etype (N, Any_Type);
9336 -- Special case of probable missing parens
9338 elsif Typ = Universal_Integer or else Typ = Any_Modular then
9339 if Parent_Is_Boolean then
9341 ("operand of not must be enclosed in parentheses",
9345 ("no modular type available in this context", N);
9348 Set_Etype (N, Any_Type);
9351 -- OK resolution of NOT
9354 -- Warn if non-boolean types involved. This is a case like not a < b
9355 -- where a and b are modular, where we will get (not a) < b and most
9356 -- likely not (a < b) was intended.
9358 if Warn_On_Questionable_Missing_Parens
9359 and then not Is_Boolean_Type (Typ)
9360 and then Parent_Is_Boolean
9362 Error_Msg_N ("?q?not expression should be parenthesized here!", N);
9365 -- Warn on double negation if checking redundant constructs
9367 if Warn_On_Redundant_Constructs
9368 and then Comes_From_Source (N)
9369 and then Comes_From_Source (Right_Opnd (N))
9370 and then Root_Type (Typ) = Standard_Boolean
9371 and then Nkind (Right_Opnd (N)) = N_Op_Not
9373 Error_Msg_N ("redundant double negation?r?", N);
9376 -- Complete resolution and evaluation of NOT
9378 Resolve (Right_Opnd (N), B_Typ);
9379 Check_Unset_Reference (Right_Opnd (N));
9380 Set_Etype (N, B_Typ);
9381 Generate_Operator_Reference (N, B_Typ);
9386 -----------------------------
9387 -- Resolve_Operator_Symbol --
9388 -----------------------------
9390 -- Nothing to be done, all resolved already
9392 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
9393 pragma Warnings (Off, N);
9394 pragma Warnings (Off, Typ);
9398 end Resolve_Operator_Symbol;
9400 ----------------------------------
9401 -- Resolve_Qualified_Expression --
9402 ----------------------------------
9404 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
9405 pragma Warnings (Off, Typ);
9407 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
9408 Expr : constant Node_Id := Expression (N);
9411 Resolve (Expr, Target_Typ);
9413 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9414 -- operation if not needed.
9416 if Restriction_Check_Required (SPARK_05)
9417 and then Is_Array_Type (Target_Typ)
9418 and then Is_Array_Type (Etype (Expr))
9419 and then Etype (Expr) /= Any_Composite -- or else Expr in error
9420 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
9422 Check_SPARK_05_Restriction
9423 ("array types should have matching static bounds", N);
9426 -- A qualified expression requires an exact match of the type, class-
9427 -- wide matching is not allowed. However, if the qualifying type is
9428 -- specific and the expression has a class-wide type, it may still be
9429 -- okay, since it can be the result of the expansion of a call to a
9430 -- dispatching function, so we also have to check class-wideness of the
9431 -- type of the expression's original node.
9433 if (Is_Class_Wide_Type (Target_Typ)
9435 (Is_Class_Wide_Type (Etype (Expr))
9436 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
9437 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
9439 Wrong_Type (Expr, Target_Typ);
9442 -- If the target type is unconstrained, then we reset the type of the
9443 -- result from the type of the expression. For other cases, the actual
9444 -- subtype of the expression is the target type.
9446 if Is_Composite_Type (Target_Typ)
9447 and then not Is_Constrained (Target_Typ)
9449 Set_Etype (N, Etype (Expr));
9452 Analyze_Dimension (N);
9453 Eval_Qualified_Expression (N);
9455 -- If we still have a qualified expression after the static evaluation,
9456 -- then apply a scalar range check if needed. The reason that we do this
9457 -- after the Eval call is that otherwise, the application of the range
9458 -- check may convert an illegal static expression and result in warning
9459 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9461 if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
9462 Apply_Scalar_Range_Check (Expr, Typ);
9465 -- Finally, check whether a predicate applies to the target type. This
9466 -- comes from AI12-0100. As for type conversions, check the enclosing
9467 -- context to prevent an infinite expansion.
9469 if Has_Predicates (Target_Typ) then
9470 if Nkind (Parent (N)) = N_Function_Call
9471 and then Present (Name (Parent (N)))
9472 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
9474 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
9478 -- In the case of a qualified expression in an allocator, the check
9479 -- is applied when expanding the allocator, so avoid redundant check.
9481 elsif Nkind (N) = N_Qualified_Expression
9482 and then Nkind (Parent (N)) /= N_Allocator
9484 Apply_Predicate_Check (N, Target_Typ);
9487 end Resolve_Qualified_Expression;
9489 ------------------------------
9490 -- Resolve_Raise_Expression --
9491 ------------------------------
9493 procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
9495 if Typ = Raise_Type then
9496 Error_Msg_N ("cannot find unique type for raise expression", N);
9497 Set_Etype (N, Any_Type);
9501 end Resolve_Raise_Expression;
9507 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
9508 L : constant Node_Id := Low_Bound (N);
9509 H : constant Node_Id := High_Bound (N);
9511 function First_Last_Ref return Boolean;
9512 -- Returns True if N is of the form X'First .. X'Last where X is the
9513 -- same entity for both attributes.
9515 --------------------
9516 -- First_Last_Ref --
9517 --------------------
9519 function First_Last_Ref return Boolean is
9520 Lorig : constant Node_Id := Original_Node (L);
9521 Horig : constant Node_Id := Original_Node (H);
9524 if Nkind (Lorig) = N_Attribute_Reference
9525 and then Nkind (Horig) = N_Attribute_Reference
9526 and then Attribute_Name (Lorig) = Name_First
9527 and then Attribute_Name (Horig) = Name_Last
9530 PL : constant Node_Id := Prefix (Lorig);
9531 PH : constant Node_Id := Prefix (Horig);
9533 if Is_Entity_Name (PL)
9534 and then Is_Entity_Name (PH)
9535 and then Entity (PL) = Entity (PH)
9545 -- Start of processing for Resolve_Range
9552 -- Check for inappropriate range on unordered enumeration type
9554 if Bad_Unordered_Enumeration_Reference (N, Typ)
9556 -- Exclude X'First .. X'Last if X is the same entity for both
9558 and then not First_Last_Ref
9560 Error_Msg_Sloc := Sloc (Typ);
9562 ("subrange of unordered enumeration type& declared#?U?", N, Typ);
9565 Check_Unset_Reference (L);
9566 Check_Unset_Reference (H);
9568 -- We have to check the bounds for being within the base range as
9569 -- required for a non-static context. Normally this is automatic and
9570 -- done as part of evaluating expressions, but the N_Range node is an
9571 -- exception, since in GNAT we consider this node to be a subexpression,
9572 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9573 -- this, but that would put the test on the main evaluation path for
9576 Check_Non_Static_Context (L);
9577 Check_Non_Static_Context (H);
9579 -- Check for an ambiguous range over character literals. This will
9580 -- happen with a membership test involving only literals.
9582 if Typ = Any_Character then
9583 Ambiguous_Character (L);
9584 Set_Etype (N, Any_Type);
9588 -- If bounds are static, constant-fold them, so size computations are
9589 -- identical between front-end and back-end. Do not perform this
9590 -- transformation while analyzing generic units, as type information
9591 -- would be lost when reanalyzing the constant node in the instance.
9593 if Is_Discrete_Type (Typ) and then Expander_Active then
9594 if Is_OK_Static_Expression (L) then
9595 Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
9598 if Is_OK_Static_Expression (H) then
9599 Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
9604 --------------------------
9605 -- Resolve_Real_Literal --
9606 --------------------------
9608 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
9609 Actual_Typ : constant Entity_Id := Etype (N);
9612 -- Special processing for fixed-point literals to make sure that the
9613 -- value is an exact multiple of small where this is required. We skip
9614 -- this for the universal real case, and also for generic types.
9616 if Is_Fixed_Point_Type (Typ)
9617 and then Typ /= Universal_Fixed
9618 and then Typ /= Any_Fixed
9619 and then not Is_Generic_Type (Typ)
9622 Val : constant Ureal := Realval (N);
9623 Cintr : constant Ureal := Val / Small_Value (Typ);
9624 Cint : constant Uint := UR_Trunc (Cintr);
9625 Den : constant Uint := Norm_Den (Cintr);
9629 -- Case of literal is not an exact multiple of the Small
9633 -- For a source program literal for a decimal fixed-point type,
9634 -- this is statically illegal (RM 4.9(36)).
9636 if Is_Decimal_Fixed_Point_Type (Typ)
9637 and then Actual_Typ = Universal_Real
9638 and then Comes_From_Source (N)
9640 Error_Msg_N ("value has extraneous low order digits", N);
9643 -- Generate a warning if literal from source
9645 if Is_OK_Static_Expression (N)
9646 and then Warn_On_Bad_Fixed_Value
9649 ("?b?static fixed-point value is not a multiple of Small!",
9653 -- Replace literal by a value that is the exact representation
9654 -- of a value of the type, i.e. a multiple of the small value,
9655 -- by truncation, since Machine_Rounds is false for all GNAT
9656 -- fixed-point types (RM 4.9(38)).
9658 Stat := Is_OK_Static_Expression (N);
9660 Make_Real_Literal (Sloc (N),
9661 Realval => Small_Value (Typ) * Cint));
9663 Set_Is_Static_Expression (N, Stat);
9666 -- In all cases, set the corresponding integer field
9668 Set_Corresponding_Integer_Value (N, Cint);
9672 -- Now replace the actual type by the expected type as usual
9675 Eval_Real_Literal (N);
9676 end Resolve_Real_Literal;
9678 -----------------------
9679 -- Resolve_Reference --
9680 -----------------------
9682 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
9683 P : constant Node_Id := Prefix (N);
9686 -- Replace general access with specific type
9688 if Ekind (Etype (N)) = E_Allocator_Type then
9689 Set_Etype (N, Base_Type (Typ));
9692 Resolve (P, Designated_Type (Etype (N)));
9694 -- If we are taking the reference of a volatile entity, then treat it as
9695 -- a potential modification of this entity. This is too conservative,
9696 -- but necessary because remove side effects can cause transformations
9697 -- of normal assignments into reference sequences that otherwise fail to
9698 -- notice the modification.
9700 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
9701 Note_Possible_Modification (P, Sure => False);
9703 end Resolve_Reference;
9705 --------------------------------
9706 -- Resolve_Selected_Component --
9707 --------------------------------
9709 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
9711 Comp1 : Entity_Id := Empty; -- prevent junk warning
9712 P : constant Node_Id := Prefix (N);
9713 S : constant Node_Id := Selector_Name (N);
9714 T : Entity_Id := Etype (P);
9716 I1 : Interp_Index := 0; -- prevent junk warning
9721 function Init_Component return Boolean;
9722 -- Check whether this is the initialization of a component within an
9723 -- init proc (by assignment or call to another init proc). If true,
9724 -- there is no need for a discriminant check.
9726 --------------------
9727 -- Init_Component --
9728 --------------------
9730 function Init_Component return Boolean is
9732 return Inside_Init_Proc
9733 and then Nkind (Prefix (N)) = N_Identifier
9734 and then Chars (Prefix (N)) = Name_uInit
9735 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
9738 -- Start of processing for Resolve_Selected_Component
9741 if Is_Overloaded (P) then
9743 -- Use the context type to select the prefix that has a selector
9744 -- of the correct name and type.
9747 Get_First_Interp (P, I, It);
9749 Search : while Present (It.Typ) loop
9750 if Is_Access_Type (It.Typ) then
9751 T := Designated_Type (It.Typ);
9756 -- Locate selected component. For a private prefix the selector
9757 -- can denote a discriminant.
9759 if Is_Record_Type (T) or else Is_Private_Type (T) then
9761 -- The visible components of a class-wide type are those of
9764 if Is_Class_Wide_Type (T) then
9768 Comp := First_Entity (T);
9769 while Present (Comp) loop
9770 if Chars (Comp) = Chars (S)
9771 and then Covers (Typ, Etype (Comp))
9780 It := Disambiguate (P, I1, I, Any_Type);
9782 if It = No_Interp then
9784 ("ambiguous prefix for selected component", N);
9791 -- There may be an implicit dereference. Retrieve
9792 -- designated record type.
9794 if Is_Access_Type (It1.Typ) then
9795 T := Designated_Type (It1.Typ);
9800 if Scope (Comp1) /= T then
9802 -- Resolution chooses the new interpretation.
9803 -- Find the component with the right name.
9805 Comp1 := First_Entity (T);
9806 while Present (Comp1)
9807 and then Chars (Comp1) /= Chars (S)
9809 Comp1 := Next_Entity (Comp1);
9818 Comp := Next_Entity (Comp);
9822 Get_Next_Interp (I, It);
9825 -- There must be a legal interpretation at this point
9827 pragma Assert (Found);
9828 Resolve (P, It1.Typ);
9830 Set_Entity_With_Checks (S, Comp1);
9833 -- Resolve prefix with its type
9838 -- Generate cross-reference. We needed to wait until full overloading
9839 -- resolution was complete to do this, since otherwise we can't tell if
9840 -- we are an lvalue or not.
9842 if May_Be_Lvalue (N) then
9843 Generate_Reference (Entity (S), S, 'm');
9845 Generate_Reference (Entity (S), S, 'r');
9848 -- If prefix is an access type, the node will be transformed into an
9849 -- explicit dereference during expansion. The type of the node is the
9850 -- designated type of that of the prefix.
9852 if Is_Access_Type (Etype (P)) then
9853 T := Designated_Type (Etype (P));
9854 Check_Fully_Declared_Prefix (T, P);
9859 -- Set flag for expander if discriminant check required on a component
9860 -- appearing within a variant.
9862 if Has_Discriminants (T)
9863 and then Ekind (Entity (S)) = E_Component
9864 and then Present (Original_Record_Component (Entity (S)))
9865 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
9867 Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
9868 and then not Discriminant_Checks_Suppressed (T)
9869 and then not Init_Component
9871 Set_Do_Discriminant_Check (N);
9874 if Ekind (Entity (S)) = E_Void then
9875 Error_Msg_N ("premature use of component", S);
9878 -- If the prefix is a record conversion, this may be a renamed
9879 -- discriminant whose bounds differ from those of the original
9880 -- one, so we must ensure that a range check is performed.
9882 if Nkind (P) = N_Type_Conversion
9883 and then Ekind (Entity (S)) = E_Discriminant
9884 and then Is_Discrete_Type (Typ)
9886 Set_Etype (N, Base_Type (Typ));
9889 -- Note: No Eval processing is required, because the prefix is of a
9890 -- record type, or protected type, and neither can possibly be static.
9892 -- If the record type is atomic, and the component is non-atomic, then
9893 -- this is worth a warning, since we have a situation where the access
9894 -- to the component may cause extra read/writes of the atomic array
9895 -- object, or partial word accesses, both of which may be unexpected.
9897 if Nkind (N) = N_Selected_Component
9898 and then Is_Atomic_Ref_With_Address (N)
9899 and then not Is_Atomic (Entity (S))
9900 and then not Is_Atomic (Etype (Entity (S)))
9903 ("??access to non-atomic component of atomic record",
9906 ("\??may cause unexpected accesses to atomic object",
9910 Analyze_Dimension (N);
9911 end Resolve_Selected_Component;
9917 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
9918 B_Typ : constant Entity_Id := Base_Type (Typ);
9919 L : constant Node_Id := Left_Opnd (N);
9920 R : constant Node_Id := Right_Opnd (N);
9923 -- We do the resolution using the base type, because intermediate values
9924 -- in expressions always are of the base type, not a subtype of it.
9927 Resolve (R, Standard_Natural);
9929 Check_Unset_Reference (L);
9930 Check_Unset_Reference (R);
9932 Set_Etype (N, B_Typ);
9933 Generate_Operator_Reference (N, B_Typ);
9937 ---------------------------
9938 -- Resolve_Short_Circuit --
9939 ---------------------------
9941 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
9942 B_Typ : constant Entity_Id := Base_Type (Typ);
9943 L : constant Node_Id := Left_Opnd (N);
9944 R : constant Node_Id := Right_Opnd (N);
9947 -- Ensure all actions associated with the left operand (e.g.
9948 -- finalization of transient objects) are fully evaluated locally within
9949 -- an expression with actions. This is particularly helpful for coverage
9950 -- analysis. However this should not happen in generics or if option
9951 -- Minimize_Expression_With_Actions is set.
9953 if Expander_Active and not Minimize_Expression_With_Actions then
9955 Reloc_L : constant Node_Id := Relocate_Node (L);
9957 Save_Interps (Old_N => L, New_N => Reloc_L);
9960 Make_Expression_With_Actions (Sloc (L),
9961 Actions => New_List,
9962 Expression => Reloc_L));
9964 -- Set Comes_From_Source on L to preserve warnings for unset
9967 Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
9974 -- Check for issuing warning for always False assert/check, this happens
9975 -- when assertions are turned off, in which case the pragma Assert/Check
9976 -- was transformed into:
9978 -- if False and then <condition> then ...
9980 -- and we detect this pattern
9982 if Warn_On_Assertion_Failure
9983 and then Is_Entity_Name (R)
9984 and then Entity (R) = Standard_False
9985 and then Nkind (Parent (N)) = N_If_Statement
9986 and then Nkind (N) = N_And_Then
9987 and then Is_Entity_Name (L)
9988 and then Entity (L) = Standard_False
9991 Orig : constant Node_Id := Original_Node (Parent (N));
9994 -- Special handling of Asssert pragma
9996 if Nkind (Orig) = N_Pragma
9997 and then Pragma_Name (Orig) = Name_Assert
10000 Expr : constant Node_Id :=
10003 (First (Pragma_Argument_Associations (Orig))));
10006 -- Don't warn if original condition is explicit False,
10007 -- since obviously the failure is expected in this case.
10009 if Is_Entity_Name (Expr)
10010 and then Entity (Expr) = Standard_False
10014 -- Issue warning. We do not want the deletion of the
10015 -- IF/AND-THEN to take this message with it. We achieve this
10016 -- by making sure that the expanded code points to the Sloc
10017 -- of the expression, not the original pragma.
10020 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10021 -- The source location of the expression is not usually
10022 -- the best choice here. For example, it gets located on
10023 -- the last AND keyword in a chain of boolean expressiond
10024 -- AND'ed together. It is best to put the message on the
10025 -- first character of the assertion, which is the effect
10026 -- of the First_Node call here.
10029 ("?A?assertion would fail at run time!",
10031 (First (Pragma_Argument_Associations (Orig))));
10035 -- Similar processing for Check pragma
10037 elsif Nkind (Orig) = N_Pragma
10038 and then Pragma_Name (Orig) = Name_Check
10040 -- Don't want to warn if original condition is explicit False
10043 Expr : constant Node_Id :=
10046 (Next (First (Pragma_Argument_Associations (Orig)))));
10048 if Is_Entity_Name (Expr)
10049 and then Entity (Expr) = Standard_False
10056 -- Again use Error_Msg_F rather than Error_Msg_N, see
10057 -- comment above for an explanation of why we do this.
10060 ("?A?check would fail at run time!",
10062 (Last (Pragma_Argument_Associations (Orig))));
10069 -- Continue with processing of short circuit
10071 Check_Unset_Reference (L);
10072 Check_Unset_Reference (R);
10074 Set_Etype (N, B_Typ);
10075 Eval_Short_Circuit (N);
10076 end Resolve_Short_Circuit;
10078 -------------------
10079 -- Resolve_Slice --
10080 -------------------
10082 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
10083 Drange : constant Node_Id := Discrete_Range (N);
10084 Name : constant Node_Id := Prefix (N);
10085 Array_Type : Entity_Id := Empty;
10086 Dexpr : Node_Id := Empty;
10087 Index_Type : Entity_Id;
10090 if Is_Overloaded (Name) then
10092 -- Use the context type to select the prefix that yields the correct
10097 I1 : Interp_Index := 0;
10099 P : constant Node_Id := Prefix (N);
10100 Found : Boolean := False;
10103 Get_First_Interp (P, I, It);
10104 while Present (It.Typ) loop
10105 if (Is_Array_Type (It.Typ)
10106 and then Covers (Typ, It.Typ))
10107 or else (Is_Access_Type (It.Typ)
10108 and then Is_Array_Type (Designated_Type (It.Typ))
10109 and then Covers (Typ, Designated_Type (It.Typ)))
10112 It := Disambiguate (P, I1, I, Any_Type);
10114 if It = No_Interp then
10115 Error_Msg_N ("ambiguous prefix for slicing", N);
10116 Set_Etype (N, Typ);
10120 Array_Type := It.Typ;
10125 Array_Type := It.Typ;
10130 Get_Next_Interp (I, It);
10135 Array_Type := Etype (Name);
10138 Resolve (Name, Array_Type);
10140 if Is_Access_Type (Array_Type) then
10141 Apply_Access_Check (N);
10142 Array_Type := Designated_Type (Array_Type);
10144 -- If the prefix is an access to an unconstrained array, we must use
10145 -- the actual subtype of the object to perform the index checks. The
10146 -- object denoted by the prefix is implicit in the node, so we build
10147 -- an explicit representation for it in order to compute the actual
10150 if not Is_Constrained (Array_Type) then
10151 Remove_Side_Effects (Prefix (N));
10154 Obj : constant Node_Id :=
10155 Make_Explicit_Dereference (Sloc (N),
10156 Prefix => New_Copy_Tree (Prefix (N)));
10158 Set_Etype (Obj, Array_Type);
10159 Set_Parent (Obj, Parent (N));
10160 Array_Type := Get_Actual_Subtype (Obj);
10164 elsif Is_Entity_Name (Name)
10165 or else Nkind (Name) = N_Explicit_Dereference
10166 or else (Nkind (Name) = N_Function_Call
10167 and then not Is_Constrained (Etype (Name)))
10169 Array_Type := Get_Actual_Subtype (Name);
10171 -- If the name is a selected component that depends on discriminants,
10172 -- build an actual subtype for it. This can happen only when the name
10173 -- itself is overloaded; otherwise the actual subtype is created when
10174 -- the selected component is analyzed.
10176 elsif Nkind (Name) = N_Selected_Component
10177 and then Full_Analysis
10178 and then Depends_On_Discriminant (First_Index (Array_Type))
10181 Act_Decl : constant Node_Id :=
10182 Build_Actual_Subtype_Of_Component (Array_Type, Name);
10184 Insert_Action (N, Act_Decl);
10185 Array_Type := Defining_Identifier (Act_Decl);
10188 -- Maybe this should just be "else", instead of checking for the
10189 -- specific case of slice??? This is needed for the case where the
10190 -- prefix is an Image attribute, which gets expanded to a slice, and so
10191 -- has a constrained subtype which we want to use for the slice range
10192 -- check applied below (the range check won't get done if the
10193 -- unconstrained subtype of the 'Image is used).
10195 elsif Nkind (Name) = N_Slice then
10196 Array_Type := Etype (Name);
10199 -- Obtain the type of the array index
10201 if Ekind (Array_Type) = E_String_Literal_Subtype then
10202 Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
10204 Index_Type := Etype (First_Index (Array_Type));
10207 -- If name was overloaded, set slice type correctly now
10209 Set_Etype (N, Array_Type);
10211 -- Handle the generation of a range check that compares the array index
10212 -- against the discrete_range. The check is not applied to internally
10213 -- built nodes associated with the expansion of dispatch tables. Check
10214 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10217 if Tagged_Type_Expansion
10218 and then RTU_Loaded (Ada_Tags)
10219 and then Nkind (Prefix (N)) = N_Selected_Component
10220 and then Present (Entity (Selector_Name (Prefix (N))))
10221 and then Entity (Selector_Name (Prefix (N))) =
10222 RTE_Record_Component (RE_Prims_Ptr)
10226 -- The discrete_range is specified by a subtype indication. Create a
10227 -- shallow copy and inherit the type, parent and source location from
10228 -- the discrete_range. This ensures that the range check is inserted
10229 -- relative to the slice and that the runtime exception points to the
10230 -- proper construct.
10232 elsif Is_Entity_Name (Drange) then
10233 Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
10235 Set_Etype (Dexpr, Etype (Drange));
10236 Set_Parent (Dexpr, Parent (Drange));
10237 Set_Sloc (Dexpr, Sloc (Drange));
10239 -- The discrete_range is a regular range. Resolve the bounds and remove
10240 -- their side effects.
10243 Resolve (Drange, Base_Type (Index_Type));
10245 if Nkind (Drange) = N_Range then
10246 Force_Evaluation (Low_Bound (Drange));
10247 Force_Evaluation (High_Bound (Drange));
10253 if Present (Dexpr) then
10254 Apply_Range_Check (Dexpr, Index_Type);
10257 Set_Slice_Subtype (N);
10259 -- Check bad use of type with predicates
10265 if Nkind (Drange) = N_Subtype_Indication
10266 and then Has_Predicates (Entity (Subtype_Mark (Drange)))
10268 Subt := Entity (Subtype_Mark (Drange));
10270 Subt := Etype (Drange);
10273 if Has_Predicates (Subt) then
10274 Bad_Predicated_Subtype_Use
10275 ("subtype& has predicate, not allowed in slice", Drange, Subt);
10279 -- Otherwise here is where we check suspicious indexes
10281 if Nkind (Drange) = N_Range then
10282 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
10283 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
10286 Analyze_Dimension (N);
10290 ----------------------------
10291 -- Resolve_String_Literal --
10292 ----------------------------
10294 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
10295 C_Typ : constant Entity_Id := Component_Type (Typ);
10296 R_Typ : constant Entity_Id := Root_Type (C_Typ);
10297 Loc : constant Source_Ptr := Sloc (N);
10298 Str : constant String_Id := Strval (N);
10299 Strlen : constant Nat := String_Length (Str);
10300 Subtype_Id : Entity_Id;
10301 Need_Check : Boolean;
10304 -- For a string appearing in a concatenation, defer creation of the
10305 -- string_literal_subtype until the end of the resolution of the
10306 -- concatenation, because the literal may be constant-folded away. This
10307 -- is a useful optimization for long concatenation expressions.
10309 -- If the string is an aggregate built for a single character (which
10310 -- happens in a non-static context) or a is null string to which special
10311 -- checks may apply, we build the subtype. Wide strings must also get a
10312 -- string subtype if they come from a one character aggregate. Strings
10313 -- generated by attributes might be static, but it is often hard to
10314 -- determine whether the enclosing context is static, so we generate
10315 -- subtypes for them as well, thus losing some rarer optimizations ???
10316 -- Same for strings that come from a static conversion.
10319 (Strlen = 0 and then Typ /= Standard_String)
10320 or else Nkind (Parent (N)) /= N_Op_Concat
10321 or else (N /= Left_Opnd (Parent (N))
10322 and then N /= Right_Opnd (Parent (N)))
10323 or else ((Typ = Standard_Wide_String
10324 or else Typ = Standard_Wide_Wide_String)
10325 and then Nkind (Original_Node (N)) /= N_String_Literal);
10327 -- If the resolving type is itself a string literal subtype, we can just
10328 -- reuse it, since there is no point in creating another.
10330 if Ekind (Typ) = E_String_Literal_Subtype then
10333 elsif Nkind (Parent (N)) = N_Op_Concat
10334 and then not Need_Check
10335 and then not Nkind_In (Original_Node (N), N_Character_Literal,
10336 N_Attribute_Reference,
10337 N_Qualified_Expression,
10342 -- Do not generate a string literal subtype for the default expression
10343 -- of a formal parameter in GNATprove mode. This is because the string
10344 -- subtype is associated with the freezing actions of the subprogram,
10345 -- however freezing is disabled in GNATprove mode and as a result the
10346 -- subtype is unavailable.
10348 elsif GNATprove_Mode
10349 and then Nkind (Parent (N)) = N_Parameter_Specification
10353 -- Otherwise we must create a string literal subtype. Note that the
10354 -- whole idea of string literal subtypes is simply to avoid the need
10355 -- for building a full fledged array subtype for each literal.
10358 Set_String_Literal_Subtype (N, Typ);
10359 Subtype_Id := Etype (N);
10362 if Nkind (Parent (N)) /= N_Op_Concat
10365 Set_Etype (N, Subtype_Id);
10366 Eval_String_Literal (N);
10369 if Is_Limited_Composite (Typ)
10370 or else Is_Private_Composite (Typ)
10372 Error_Msg_N ("string literal not available for private array", N);
10373 Set_Etype (N, Any_Type);
10377 -- The validity of a null string has been checked in the call to
10378 -- Eval_String_Literal.
10383 -- Always accept string literal with component type Any_Character, which
10384 -- occurs in error situations and in comparisons of literals, both of
10385 -- which should accept all literals.
10387 elsif R_Typ = Any_Character then
10390 -- If the type is bit-packed, then we always transform the string
10391 -- literal into a full fledged aggregate.
10393 elsif Is_Bit_Packed_Array (Typ) then
10396 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10399 -- For Standard.Wide_Wide_String, or any other type whose component
10400 -- type is Standard.Wide_Wide_Character, we know that all the
10401 -- characters in the string must be acceptable, since the parser
10402 -- accepted the characters as valid character literals.
10404 if R_Typ = Standard_Wide_Wide_Character then
10407 -- For the case of Standard.String, or any other type whose component
10408 -- type is Standard.Character, we must make sure that there are no
10409 -- wide characters in the string, i.e. that it is entirely composed
10410 -- of characters in range of type Character.
10412 -- If the string literal is the result of a static concatenation, the
10413 -- test has already been performed on the components, and need not be
10416 elsif R_Typ = Standard_Character
10417 and then Nkind (Original_Node (N)) /= N_Op_Concat
10419 for J in 1 .. Strlen loop
10420 if not In_Character_Range (Get_String_Char (Str, J)) then
10422 -- If we are out of range, post error. This is one of the
10423 -- very few places that we place the flag in the middle of
10424 -- a token, right under the offending wide character. Not
10425 -- quite clear if this is right wrt wide character encoding
10426 -- sequences, but it's only an error message.
10429 ("literal out of range of type Standard.Character",
10430 Source_Ptr (Int (Loc) + J));
10435 -- For the case of Standard.Wide_String, or any other type whose
10436 -- component type is Standard.Wide_Character, we must make sure that
10437 -- there are no wide characters in the string, i.e. that it is
10438 -- entirely composed of characters in range of type Wide_Character.
10440 -- If the string literal is the result of a static concatenation,
10441 -- the test has already been performed on the components, and need
10442 -- not be repeated.
10444 elsif R_Typ = Standard_Wide_Character
10445 and then Nkind (Original_Node (N)) /= N_Op_Concat
10447 for J in 1 .. Strlen loop
10448 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
10450 -- If we are out of range, post error. This is one of the
10451 -- very few places that we place the flag in the middle of
10452 -- a token, right under the offending wide character.
10454 -- This is not quite right, because characters in general
10455 -- will take more than one character position ???
10458 ("literal out of range of type Standard.Wide_Character",
10459 Source_Ptr (Int (Loc) + J));
10464 -- If the root type is not a standard character, then we will convert
10465 -- the string into an aggregate and will let the aggregate code do
10466 -- the checking. Standard Wide_Wide_Character is also OK here.
10472 -- See if the component type of the array corresponding to the string
10473 -- has compile time known bounds. If yes we can directly check
10474 -- whether the evaluation of the string will raise constraint error.
10475 -- Otherwise we need to transform the string literal into the
10476 -- corresponding character aggregate and let the aggregate code do
10479 if Is_Standard_Character_Type (R_Typ) then
10481 -- Check for the case of full range, where we are definitely OK
10483 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
10487 -- Here the range is not the complete base type range, so check
10490 Comp_Typ_Lo : constant Node_Id :=
10491 Type_Low_Bound (Component_Type (Typ));
10492 Comp_Typ_Hi : constant Node_Id :=
10493 Type_High_Bound (Component_Type (Typ));
10498 if Compile_Time_Known_Value (Comp_Typ_Lo)
10499 and then Compile_Time_Known_Value (Comp_Typ_Hi)
10501 for J in 1 .. Strlen loop
10502 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
10504 if Char_Val < Expr_Value (Comp_Typ_Lo)
10505 or else Char_Val > Expr_Value (Comp_Typ_Hi)
10507 Apply_Compile_Time_Constraint_Error
10508 (N, "character out of range??",
10509 CE_Range_Check_Failed,
10510 Loc => Source_Ptr (Int (Loc) + J));
10520 -- If we got here we meed to transform the string literal into the
10521 -- equivalent qualified positional array aggregate. This is rather
10522 -- heavy artillery for this situation, but it is hard work to avoid.
10525 Lits : constant List_Id := New_List;
10526 P : Source_Ptr := Loc + 1;
10530 -- Build the character literals, we give them source locations that
10531 -- correspond to the string positions, which is a bit tricky given
10532 -- the possible presence of wide character escape sequences.
10534 for J in 1 .. Strlen loop
10535 C := Get_String_Char (Str, J);
10536 Set_Character_Literal_Name (C);
10539 Make_Character_Literal (P,
10540 Chars => Name_Find,
10541 Char_Literal_Value => UI_From_CC (C)));
10543 if In_Character_Range (C) then
10546 -- Should we have a call to Skip_Wide here ???
10555 Make_Qualified_Expression (Loc,
10556 Subtype_Mark => New_Occurrence_Of (Typ, Loc),
10558 Make_Aggregate (Loc, Expressions => Lits)));
10560 Analyze_And_Resolve (N, Typ);
10562 end Resolve_String_Literal;
10564 -----------------------------
10565 -- Resolve_Type_Conversion --
10566 -----------------------------
10568 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
10569 Conv_OK : constant Boolean := Conversion_OK (N);
10570 Operand : constant Node_Id := Expression (N);
10571 Operand_Typ : constant Entity_Id := Etype (Operand);
10572 Target_Typ : constant Entity_Id := Etype (N);
10577 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
10578 -- Set to False to suppress cases where we want to suppress the test
10579 -- for redundancy to avoid possible false positives on this warning.
10583 and then not Valid_Conversion (N, Target_Typ, Operand)
10588 -- If the Operand Etype is Universal_Fixed, then the conversion is
10589 -- never redundant. We need this check because by the time we have
10590 -- finished the rather complex transformation, the conversion looks
10591 -- redundant when it is not.
10593 if Operand_Typ = Universal_Fixed then
10594 Test_Redundant := False;
10596 -- If the operand is marked as Any_Fixed, then special processing is
10597 -- required. This is also a case where we suppress the test for a
10598 -- redundant conversion, since most certainly it is not redundant.
10600 elsif Operand_Typ = Any_Fixed then
10601 Test_Redundant := False;
10603 -- Mixed-mode operation involving a literal. Context must be a fixed
10604 -- type which is applied to the literal subsequently.
10606 if Is_Fixed_Point_Type (Typ) then
10607 Set_Etype (Operand, Universal_Real);
10609 elsif Is_Numeric_Type (Typ)
10610 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
10611 and then (Etype (Right_Opnd (Operand)) = Universal_Real
10613 Etype (Left_Opnd (Operand)) = Universal_Real)
10615 -- Return if expression is ambiguous
10617 if Unique_Fixed_Point_Type (N) = Any_Type then
10620 -- If nothing else, the available fixed type is Duration
10623 Set_Etype (Operand, Standard_Duration);
10626 -- Resolve the real operand with largest available precision
10628 if Etype (Right_Opnd (Operand)) = Universal_Real then
10629 Rop := New_Copy_Tree (Right_Opnd (Operand));
10631 Rop := New_Copy_Tree (Left_Opnd (Operand));
10634 Resolve (Rop, Universal_Real);
10636 -- If the operand is a literal (it could be a non-static and
10637 -- illegal exponentiation) check whether the use of Duration
10638 -- is potentially inaccurate.
10640 if Nkind (Rop) = N_Real_Literal
10641 and then Realval (Rop) /= Ureal_0
10642 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
10645 ("??universal real operand can only "
10646 & "be interpreted as Duration!", Rop);
10648 ("\??precision will be lost in the conversion!", Rop);
10651 elsif Is_Numeric_Type (Typ)
10652 and then Nkind (Operand) in N_Op
10653 and then Unique_Fixed_Point_Type (N) /= Any_Type
10655 Set_Etype (Operand, Standard_Duration);
10658 Error_Msg_N ("invalid context for mixed mode operation", N);
10659 Set_Etype (Operand, Any_Type);
10666 -- In SPARK, a type conversion between array types should be restricted
10667 -- to types which have matching static bounds.
10669 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10670 -- operation if not needed.
10672 if Restriction_Check_Required (SPARK_05)
10673 and then Is_Array_Type (Target_Typ)
10674 and then Is_Array_Type (Operand_Typ)
10675 and then Operand_Typ /= Any_Composite -- or else Operand in error
10676 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
10678 Check_SPARK_05_Restriction
10679 ("array types should have matching static bounds", N);
10682 -- In formal mode, the operand of an ancestor type conversion must be an
10683 -- object (not an expression).
10685 if Is_Tagged_Type (Target_Typ)
10686 and then not Is_Class_Wide_Type (Target_Typ)
10687 and then Is_Tagged_Type (Operand_Typ)
10688 and then not Is_Class_Wide_Type (Operand_Typ)
10689 and then Is_Ancestor (Target_Typ, Operand_Typ)
10690 and then not Is_SPARK_05_Object_Reference (Operand)
10692 Check_SPARK_05_Restriction ("object required", Operand);
10695 Analyze_Dimension (N);
10697 -- Note: we do the Eval_Type_Conversion call before applying the
10698 -- required checks for a subtype conversion. This is important, since
10699 -- both are prepared under certain circumstances to change the type
10700 -- conversion to a constraint error node, but in the case of
10701 -- Eval_Type_Conversion this may reflect an illegality in the static
10702 -- case, and we would miss the illegality (getting only a warning
10703 -- message), if we applied the type conversion checks first.
10705 Eval_Type_Conversion (N);
10707 -- Even when evaluation is not possible, we may be able to simplify the
10708 -- conversion or its expression. This needs to be done before applying
10709 -- checks, since otherwise the checks may use the original expression
10710 -- and defeat the simplifications. This is specifically the case for
10711 -- elimination of the floating-point Truncation attribute in
10712 -- float-to-int conversions.
10714 Simplify_Type_Conversion (N);
10716 -- If after evaluation we still have a type conversion, then we may need
10717 -- to apply checks required for a subtype conversion.
10719 -- Skip these type conversion checks if universal fixed operands
10720 -- operands involved, since range checks are handled separately for
10721 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10723 if Nkind (N) = N_Type_Conversion
10724 and then not Is_Generic_Type (Root_Type (Target_Typ))
10725 and then Target_Typ /= Universal_Fixed
10726 and then Operand_Typ /= Universal_Fixed
10728 Apply_Type_Conversion_Checks (N);
10731 -- Issue warning for conversion of simple object to its own type. We
10732 -- have to test the original nodes, since they may have been rewritten
10733 -- by various optimizations.
10735 Orig_N := Original_Node (N);
10737 -- Here we test for a redundant conversion if the warning mode is
10738 -- active (and was not locally reset), and we have a type conversion
10739 -- from source not appearing in a generic instance.
10742 and then Nkind (Orig_N) = N_Type_Conversion
10743 and then Comes_From_Source (Orig_N)
10744 and then not In_Instance
10746 Orig_N := Original_Node (Expression (Orig_N));
10747 Orig_T := Target_Typ;
10749 -- If the node is part of a larger expression, the Target_Type
10750 -- may not be the original type of the node if the context is a
10751 -- condition. Recover original type to see if conversion is needed.
10753 if Is_Boolean_Type (Orig_T)
10754 and then Nkind (Parent (N)) in N_Op
10756 Orig_T := Etype (Parent (N));
10759 -- If we have an entity name, then give the warning if the entity
10760 -- is the right type, or if it is a loop parameter covered by the
10761 -- original type (that's needed because loop parameters have an
10762 -- odd subtype coming from the bounds).
10764 if (Is_Entity_Name (Orig_N)
10766 (Etype (Entity (Orig_N)) = Orig_T
10768 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
10769 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
10771 -- If not an entity, then type of expression must match
10773 or else Etype (Orig_N) = Orig_T
10775 -- One more check, do not give warning if the analyzed conversion
10776 -- has an expression with non-static bounds, and the bounds of the
10777 -- target are static. This avoids junk warnings in cases where the
10778 -- conversion is necessary to establish staticness, for example in
10779 -- a case statement.
10781 if not Is_OK_Static_Subtype (Operand_Typ)
10782 and then Is_OK_Static_Subtype (Target_Typ)
10786 -- Finally, if this type conversion occurs in a context requiring
10787 -- a prefix, and the expression is a qualified expression then the
10788 -- type conversion is not redundant, since a qualified expression
10789 -- is not a prefix, whereas a type conversion is. For example, "X
10790 -- := T'(Funx(...)).Y;" is illegal because a selected component
10791 -- requires a prefix, but a type conversion makes it legal: "X :=
10792 -- T(T'(Funx(...))).Y;"
10794 -- In Ada 2012, a qualified expression is a name, so this idiom is
10795 -- no longer needed, but we still suppress the warning because it
10796 -- seems unfriendly for warnings to pop up when you switch to the
10797 -- newer language version.
10799 elsif Nkind (Orig_N) = N_Qualified_Expression
10800 and then Nkind_In (Parent (N), N_Attribute_Reference,
10801 N_Indexed_Component,
10802 N_Selected_Component,
10804 N_Explicit_Dereference)
10808 -- Never warn on conversion to Long_Long_Integer'Base since
10809 -- that is most likely an artifact of the extended overflow
10810 -- checking and comes from complex expanded code.
10812 elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
10815 -- Here we give the redundant conversion warning. If it is an
10816 -- entity, give the name of the entity in the message. If not,
10817 -- just mention the expression.
10819 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10822 if Is_Entity_Name (Orig_N) then
10823 Error_Msg_Node_2 := Orig_T;
10824 Error_Msg_NE -- CODEFIX
10825 ("??redundant conversion, & is of type &!",
10826 N, Entity (Orig_N));
10829 ("??redundant conversion, expression is of type&!",
10836 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10837 -- No need to perform any interface conversion if the type of the
10838 -- expression coincides with the target type.
10840 if Ada_Version >= Ada_2005
10841 and then Expander_Active
10842 and then Operand_Typ /= Target_Typ
10845 Opnd : Entity_Id := Operand_Typ;
10846 Target : Entity_Id := Target_Typ;
10849 -- If the type of the operand is a limited view, use nonlimited
10850 -- view when available. If it is a class-wide type, recover the
10851 -- class-wide type of the nonlimited view.
10853 if From_Limited_With (Opnd)
10854 and then Has_Non_Limited_View (Opnd)
10856 Opnd := Non_Limited_View (Opnd);
10857 Set_Etype (Expression (N), Opnd);
10860 if Is_Access_Type (Opnd) then
10861 Opnd := Designated_Type (Opnd);
10864 if Is_Access_Type (Target_Typ) then
10865 Target := Designated_Type (Target);
10868 if Opnd = Target then
10871 -- Conversion from interface type
10873 elsif Is_Interface (Opnd) then
10875 -- Ada 2005 (AI-217): Handle entities from limited views
10877 if From_Limited_With (Opnd) then
10878 Error_Msg_Qual_Level := 99;
10879 Error_Msg_NE -- CODEFIX
10880 ("missing WITH clause on package &", N,
10881 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
10883 ("type conversions require visibility of the full view",
10886 elsif From_Limited_With (Target)
10888 (Is_Access_Type (Target_Typ)
10889 and then Present (Non_Limited_View (Etype (Target))))
10891 Error_Msg_Qual_Level := 99;
10892 Error_Msg_NE -- CODEFIX
10893 ("missing WITH clause on package &", N,
10894 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
10896 ("type conversions require visibility of the full view",
10900 Expand_Interface_Conversion (N);
10903 -- Conversion to interface type
10905 elsif Is_Interface (Target) then
10909 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
10910 Opnd := Etype (Opnd);
10913 if Is_Class_Wide_Type (Opnd)
10914 or else Interface_Present_In_Ancestor
10918 Expand_Interface_Conversion (N);
10920 Error_Msg_Name_1 := Chars (Etype (Target));
10921 Error_Msg_Name_2 := Chars (Opnd);
10923 ("wrong interface conversion (% is not a progenitor "
10930 -- Ada 2012: if target type has predicates, the result requires a
10931 -- predicate check. If the context is a call to another predicate
10932 -- check we must prevent infinite recursion.
10934 if Has_Predicates (Target_Typ) then
10935 if Nkind (Parent (N)) = N_Function_Call
10936 and then Present (Name (Parent (N)))
10937 and then (Is_Predicate_Function (Entity (Name (Parent (N))))
10939 Is_Predicate_Function_M (Entity (Name (Parent (N)))))
10944 Apply_Predicate_Check (N, Target_Typ);
10948 -- If at this stage we have a real to integer conversion, make sure
10949 -- that the Do_Range_Check flag is set, because such conversions in
10950 -- general need a range check. We only need this if expansion is off
10951 -- or we are in GNATProve mode.
10953 if Nkind (N) = N_Type_Conversion
10954 and then (GNATprove_Mode or not Expander_Active)
10955 and then Is_Integer_Type (Target_Typ)
10956 and then Is_Real_Type (Operand_Typ)
10958 Set_Do_Range_Check (Operand);
10961 -- Generating C code a type conversion of an access to constrained
10962 -- array type to access to unconstrained array type involves building
10963 -- a fat pointer which in general cannot be generated on the fly. We
10964 -- remove side effects in order to store the result of the conversion
10965 -- into a temporary.
10968 and then Nkind (N) = N_Type_Conversion
10969 and then Nkind (Parent (N)) /= N_Object_Declaration
10970 and then Is_Access_Type (Etype (N))
10971 and then Is_Array_Type (Designated_Type (Etype (N)))
10972 and then not Is_Constrained (Designated_Type (Etype (N)))
10973 and then Is_Constrained (Designated_Type (Etype (Expression (N))))
10975 Remove_Side_Effects (N);
10977 end Resolve_Type_Conversion;
10979 ----------------------
10980 -- Resolve_Unary_Op --
10981 ----------------------
10983 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
10984 B_Typ : constant Entity_Id := Base_Type (Typ);
10985 R : constant Node_Id := Right_Opnd (N);
10991 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
10992 Error_Msg_Name_1 := Chars (Typ);
10993 Check_SPARK_05_Restriction
10994 ("unary operator not defined for modular type%", N);
10997 -- Deal with intrinsic unary operators
10999 if Comes_From_Source (N)
11000 and then Ekind (Entity (N)) = E_Function
11001 and then Is_Imported (Entity (N))
11002 and then Is_Intrinsic_Subprogram (Entity (N))
11004 Resolve_Intrinsic_Unary_Operator (N, Typ);
11008 -- Deal with universal cases
11010 if Etype (R) = Universal_Integer
11012 Etype (R) = Universal_Real
11014 Check_For_Visible_Operator (N, B_Typ);
11017 Set_Etype (N, B_Typ);
11018 Resolve (R, B_Typ);
11020 -- Generate warning for expressions like abs (x mod 2)
11022 if Warn_On_Redundant_Constructs
11023 and then Nkind (N) = N_Op_Abs
11025 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
11027 if OK and then Hi >= Lo and then Lo >= 0 then
11028 Error_Msg_N -- CODEFIX
11029 ("?r?abs applied to known non-negative value has no effect", N);
11033 -- Deal with reference generation
11035 Check_Unset_Reference (R);
11036 Generate_Operator_Reference (N, B_Typ);
11037 Analyze_Dimension (N);
11040 -- Set overflow checking bit. Much cleverer code needed here eventually
11041 -- and perhaps the Resolve routines should be separated for the various
11042 -- arithmetic operations, since they will need different processing ???
11044 if Nkind (N) in N_Op then
11045 if not Overflow_Checks_Suppressed (Etype (N)) then
11046 Enable_Overflow_Check (N);
11050 -- Generate warning for expressions like -5 mod 3 for integers. No need
11051 -- to worry in the floating-point case, since parens do not affect the
11052 -- result so there is no point in giving in a warning.
11055 Norig : constant Node_Id := Original_Node (N);
11064 if Warn_On_Questionable_Missing_Parens
11065 and then Comes_From_Source (Norig)
11066 and then Is_Integer_Type (Typ)
11067 and then Nkind (Norig) = N_Op_Minus
11069 Rorig := Original_Node (Right_Opnd (Norig));
11071 -- We are looking for cases where the right operand is not
11072 -- parenthesized, and is a binary operator, multiply, divide, or
11073 -- mod. These are the cases where the grouping can affect results.
11075 if Paren_Count (Rorig) = 0
11076 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
11078 -- For mod, we always give the warning, since the value is
11079 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11080 -- -(5 mod 315)). But for the other cases, the only concern is
11081 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11082 -- overflows, but (-2) * 64 does not). So we try to give the
11083 -- message only when overflow is possible.
11085 if Nkind (Rorig) /= N_Op_Mod
11086 and then Compile_Time_Known_Value (R)
11088 Val := Expr_Value (R);
11090 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
11091 HB := Expr_Value (Type_High_Bound (Typ));
11093 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
11096 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
11097 LB := Expr_Value (Type_Low_Bound (Typ));
11099 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
11102 -- Note that the test below is deliberately excluding the
11103 -- largest negative number, since that is a potentially
11104 -- troublesome case (e.g. -2 * x, where the result is the
11105 -- largest negative integer has an overflow with 2 * x).
11107 if Val > LB and then Val <= HB then
11112 -- For the multiplication case, the only case we have to worry
11113 -- about is when (-a)*b is exactly the largest negative number
11114 -- so that -(a*b) can cause overflow. This can only happen if
11115 -- a is a power of 2, and more generally if any operand is a
11116 -- constant that is not a power of 2, then the parentheses
11117 -- cannot affect whether overflow occurs. We only bother to
11118 -- test the left most operand
11120 -- Loop looking at left operands for one that has known value
11123 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
11124 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
11125 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
11127 -- Operand value of 0 or 1 skips warning
11132 -- Otherwise check power of 2, if power of 2, warn, if
11133 -- anything else, skip warning.
11136 while Lval /= 2 loop
11137 if Lval mod 2 = 1 then
11148 -- Keep looking at left operands
11150 Opnd := Left_Opnd (Opnd);
11151 end loop Opnd_Loop;
11153 -- For rem or "/" we can only have a problematic situation
11154 -- if the divisor has a value of minus one or one. Otherwise
11155 -- overflow is impossible (divisor > 1) or we have a case of
11156 -- division by zero in any case.
11158 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
11159 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
11160 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
11165 -- If we fall through warning should be issued
11167 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11170 ("??unary minus expression should be parenthesized here!", N);
11174 end Resolve_Unary_Op;
11176 ----------------------------------
11177 -- Resolve_Unchecked_Expression --
11178 ----------------------------------
11180 procedure Resolve_Unchecked_Expression
11185 Resolve (Expression (N), Typ, Suppress => All_Checks);
11186 Set_Etype (N, Typ);
11187 end Resolve_Unchecked_Expression;
11189 ---------------------------------------
11190 -- Resolve_Unchecked_Type_Conversion --
11191 ---------------------------------------
11193 procedure Resolve_Unchecked_Type_Conversion
11197 pragma Warnings (Off, Typ);
11199 Operand : constant Node_Id := Expression (N);
11200 Opnd_Type : constant Entity_Id := Etype (Operand);
11203 -- Resolve operand using its own type
11205 Resolve (Operand, Opnd_Type);
11207 -- In an inlined context, the unchecked conversion may be applied
11208 -- to a literal, in which case its type is the type of the context.
11209 -- (In other contexts conversions cannot apply to literals).
11212 and then (Opnd_Type = Any_Character or else
11213 Opnd_Type = Any_Integer or else
11214 Opnd_Type = Any_Real)
11216 Set_Etype (Operand, Typ);
11219 Analyze_Dimension (N);
11220 Eval_Unchecked_Conversion (N);
11221 end Resolve_Unchecked_Type_Conversion;
11223 ------------------------------
11224 -- Rewrite_Operator_As_Call --
11225 ------------------------------
11227 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
11228 Loc : constant Source_Ptr := Sloc (N);
11229 Actuals : constant List_Id := New_List;
11233 if Nkind (N) in N_Binary_Op then
11234 Append (Left_Opnd (N), Actuals);
11237 Append (Right_Opnd (N), Actuals);
11240 Make_Function_Call (Sloc => Loc,
11241 Name => New_Occurrence_Of (Nam, Loc),
11242 Parameter_Associations => Actuals);
11244 Preserve_Comes_From_Source (New_N, N);
11245 Preserve_Comes_From_Source (Name (New_N), N);
11246 Rewrite (N, New_N);
11247 Set_Etype (N, Etype (Nam));
11248 end Rewrite_Operator_As_Call;
11250 ------------------------------
11251 -- Rewrite_Renamed_Operator --
11252 ------------------------------
11254 procedure Rewrite_Renamed_Operator
11259 Nam : constant Name_Id := Chars (Op);
11260 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
11264 -- Do not perform this transformation within a pre/postcondition,
11265 -- because the expression will be re-analyzed, and the transformation
11266 -- might affect the visibility of the operator, e.g. in an instance.
11267 -- Note that fully analyzed and expanded pre/postconditions appear as
11268 -- pragma Check equivalents.
11270 if In_Pre_Post_Condition (N) then
11274 -- Rewrite the operator node using the real operator, not its renaming.
11275 -- Exclude user-defined intrinsic operations of the same name, which are
11276 -- treated separately and rewritten as calls.
11278 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
11279 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
11280 Set_Chars (Op_Node, Nam);
11281 Set_Etype (Op_Node, Etype (N));
11282 Set_Entity (Op_Node, Op);
11283 Set_Right_Opnd (Op_Node, Right_Opnd (N));
11285 -- Indicate that both the original entity and its renaming are
11286 -- referenced at this point.
11288 Generate_Reference (Entity (N), N);
11289 Generate_Reference (Op, N);
11292 Set_Left_Opnd (Op_Node, Left_Opnd (N));
11295 Rewrite (N, Op_Node);
11297 -- If the context type is private, add the appropriate conversions so
11298 -- that the operator is applied to the full view. This is done in the
11299 -- routines that resolve intrinsic operators.
11301 if Is_Intrinsic_Subprogram (Op) and then Is_Private_Type (Typ) then
11303 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
11304 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
11305 Resolve_Intrinsic_Operator (N, Typ);
11307 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
11308 Resolve_Intrinsic_Unary_Operator (N, Typ);
11315 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
11317 -- Operator renames a user-defined operator of the same name. Use the
11318 -- original operator in the node, which is the one Gigi knows about.
11320 Set_Entity (N, Op);
11321 Set_Is_Overloaded (N, False);
11323 end Rewrite_Renamed_Operator;
11325 -----------------------
11326 -- Set_Slice_Subtype --
11327 -----------------------
11329 -- Build an implicit subtype declaration to represent the type delivered by
11330 -- the slice. This is an abbreviated version of an array subtype. We define
11331 -- an index subtype for the slice, using either the subtype name or the
11332 -- discrete range of the slice. To be consistent with index usage elsewhere
11333 -- we create a list header to hold the single index. This list is not
11334 -- otherwise attached to the syntax tree.
11336 procedure Set_Slice_Subtype (N : Node_Id) is
11337 Loc : constant Source_Ptr := Sloc (N);
11338 Index_List : constant List_Id := New_List;
11340 Index_Subtype : Entity_Id;
11341 Index_Type : Entity_Id;
11342 Slice_Subtype : Entity_Id;
11343 Drange : constant Node_Id := Discrete_Range (N);
11346 Index_Type := Base_Type (Etype (Drange));
11348 if Is_Entity_Name (Drange) then
11349 Index_Subtype := Entity (Drange);
11352 -- We force the evaluation of a range. This is definitely needed in
11353 -- the renamed case, and seems safer to do unconditionally. Note in
11354 -- any case that since we will create and insert an Itype referring
11355 -- to this range, we must make sure any side effect removal actions
11356 -- are inserted before the Itype definition.
11358 if Nkind (Drange) = N_Range then
11359 Force_Evaluation (Low_Bound (Drange));
11360 Force_Evaluation (High_Bound (Drange));
11362 -- If the discrete range is given by a subtype indication, the
11363 -- type of the slice is the base of the subtype mark.
11365 elsif Nkind (Drange) = N_Subtype_Indication then
11367 R : constant Node_Id := Range_Expression (Constraint (Drange));
11369 Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
11370 Force_Evaluation (Low_Bound (R));
11371 Force_Evaluation (High_Bound (R));
11375 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11377 -- Take a new copy of Drange (where bounds have been rewritten to
11378 -- reference side-effect-free names). Using a separate tree ensures
11379 -- that further expansion (e.g. while rewriting a slice assignment
11380 -- into a FOR loop) does not attempt to remove side effects on the
11381 -- bounds again (which would cause the bounds in the index subtype
11382 -- definition to refer to temporaries before they are defined) (the
11383 -- reason is that some names are considered side effect free here
11384 -- for the subtype, but not in the context of a loop iteration
11387 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
11388 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
11389 Set_Etype (Index_Subtype, Index_Type);
11390 Set_Size_Info (Index_Subtype, Index_Type);
11391 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11394 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
11396 Index := New_Occurrence_Of (Index_Subtype, Loc);
11397 Set_Etype (Index, Index_Subtype);
11398 Append (Index, Index_List);
11400 Set_First_Index (Slice_Subtype, Index);
11401 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
11402 Set_Is_Constrained (Slice_Subtype, True);
11404 Check_Compile_Time_Size (Slice_Subtype);
11406 -- The Etype of the existing Slice node is reset to this slice subtype.
11407 -- Its bounds are obtained from its first index.
11409 Set_Etype (N, Slice_Subtype);
11411 -- For packed slice subtypes, freeze immediately (except in the case of
11412 -- being in a "spec expression" where we never freeze when we first see
11413 -- the expression).
11415 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
11416 Freeze_Itype (Slice_Subtype, N);
11418 -- For all other cases insert an itype reference in the slice's actions
11419 -- so that the itype is frozen at the proper place in the tree (i.e. at
11420 -- the point where actions for the slice are analyzed). Note that this
11421 -- is different from freezing the itype immediately, which might be
11422 -- premature (e.g. if the slice is within a transient scope). This needs
11423 -- to be done only if expansion is enabled.
11425 elsif Expander_Active then
11426 Ensure_Defined (Typ => Slice_Subtype, N => N);
11428 end Set_Slice_Subtype;
11430 --------------------------------
11431 -- Set_String_Literal_Subtype --
11432 --------------------------------
11434 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
11435 Loc : constant Source_Ptr := Sloc (N);
11436 Low_Bound : constant Node_Id :=
11437 Type_Low_Bound (Etype (First_Index (Typ)));
11438 Subtype_Id : Entity_Id;
11441 if Nkind (N) /= N_String_Literal then
11445 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
11446 Set_String_Literal_Length (Subtype_Id, UI_From_Int
11447 (String_Length (Strval (N))));
11448 Set_Etype (Subtype_Id, Base_Type (Typ));
11449 Set_Is_Constrained (Subtype_Id);
11450 Set_Etype (N, Subtype_Id);
11452 -- The low bound is set from the low bound of the corresponding index
11453 -- type. Note that we do not store the high bound in the string literal
11454 -- subtype, but it can be deduced if necessary from the length and the
11457 if Is_OK_Static_Expression (Low_Bound) then
11458 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
11460 -- If the lower bound is not static we create a range for the string
11461 -- literal, using the index type and the known length of the literal.
11462 -- The index type is not necessarily Positive, so the upper bound is
11463 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11467 Index_List : constant List_Id := New_List;
11468 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
11469 High_Bound : constant Node_Id :=
11470 Make_Attribute_Reference (Loc,
11471 Attribute_Name => Name_Val,
11473 New_Occurrence_Of (Index_Type, Loc),
11474 Expressions => New_List (
11477 Make_Attribute_Reference (Loc,
11478 Attribute_Name => Name_Pos,
11480 New_Occurrence_Of (Index_Type, Loc),
11482 New_List (New_Copy_Tree (Low_Bound))),
11484 Make_Integer_Literal (Loc,
11485 String_Length (Strval (N)) - 1))));
11487 Array_Subtype : Entity_Id;
11490 Index_Subtype : Entity_Id;
11493 if Is_Integer_Type (Index_Type) then
11494 Set_String_Literal_Low_Bound
11495 (Subtype_Id, Make_Integer_Literal (Loc, 1));
11498 -- If the index type is an enumeration type, build bounds
11499 -- expression with attributes.
11501 Set_String_Literal_Low_Bound
11503 Make_Attribute_Reference (Loc,
11504 Attribute_Name => Name_First,
11506 New_Occurrence_Of (Base_Type (Index_Type), Loc)));
11507 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
11510 Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
11512 -- Build bona fide subtype for the string, and wrap it in an
11513 -- unchecked conversion, because the backend expects the
11514 -- String_Literal_Subtype to have a static lower bound.
11517 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
11518 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
11519 Set_Scalar_Range (Index_Subtype, Drange);
11520 Set_Parent (Drange, N);
11521 Analyze_And_Resolve (Drange, Index_Type);
11523 -- In the context, the Index_Type may already have a constraint,
11524 -- so use common base type on string subtype. The base type may
11525 -- be used when generating attributes of the string, for example
11526 -- in the context of a slice assignment.
11528 Set_Etype (Index_Subtype, Base_Type (Index_Type));
11529 Set_Size_Info (Index_Subtype, Index_Type);
11530 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
11532 Array_Subtype := Create_Itype (E_Array_Subtype, N);
11534 Index := New_Occurrence_Of (Index_Subtype, Loc);
11535 Set_Etype (Index, Index_Subtype);
11536 Append (Index, Index_List);
11538 Set_First_Index (Array_Subtype, Index);
11539 Set_Etype (Array_Subtype, Base_Type (Typ));
11540 Set_Is_Constrained (Array_Subtype, True);
11543 Make_Unchecked_Type_Conversion (Loc,
11544 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
11545 Expression => Relocate_Node (N)));
11546 Set_Etype (N, Array_Subtype);
11549 end Set_String_Literal_Subtype;
11551 ------------------------------
11552 -- Simplify_Type_Conversion --
11553 ------------------------------
11555 procedure Simplify_Type_Conversion (N : Node_Id) is
11557 if Nkind (N) = N_Type_Conversion then
11559 Operand : constant Node_Id := Expression (N);
11560 Target_Typ : constant Entity_Id := Etype (N);
11561 Opnd_Typ : constant Entity_Id := Etype (Operand);
11564 -- Special processing if the conversion is the expression of a
11565 -- Rounding or Truncation attribute reference. In this case we
11568 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11574 -- with the Float_Truncate flag set to False or True respectively,
11575 -- which is more efficient.
11577 if Is_Floating_Point_Type (Opnd_Typ)
11579 (Is_Integer_Type (Target_Typ)
11580 or else (Is_Fixed_Point_Type (Target_Typ)
11581 and then Conversion_OK (N)))
11582 and then Nkind (Operand) = N_Attribute_Reference
11583 and then Nam_In (Attribute_Name (Operand), Name_Rounding,
11587 Truncate : constant Boolean :=
11588 Attribute_Name (Operand) = Name_Truncation;
11591 Relocate_Node (First (Expressions (Operand))));
11592 Set_Float_Truncate (N, Truncate);
11597 end Simplify_Type_Conversion;
11599 -----------------------------
11600 -- Unique_Fixed_Point_Type --
11601 -----------------------------
11603 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
11604 T1 : Entity_Id := Empty;
11609 procedure Fixed_Point_Error;
11610 -- Give error messages for true ambiguity. Messages are posted on node
11611 -- N, and entities T1, T2 are the possible interpretations.
11613 -----------------------
11614 -- Fixed_Point_Error --
11615 -----------------------
11617 procedure Fixed_Point_Error is
11619 Error_Msg_N ("ambiguous universal_fixed_expression", N);
11620 Error_Msg_NE ("\\possible interpretation as}", N, T1);
11621 Error_Msg_NE ("\\possible interpretation as}", N, T2);
11622 end Fixed_Point_Error;
11624 -- Start of processing for Unique_Fixed_Point_Type
11627 -- The operations on Duration are visible, so Duration is always a
11628 -- possible interpretation.
11630 T1 := Standard_Duration;
11632 -- Look for fixed-point types in enclosing scopes
11634 Scop := Current_Scope;
11635 while Scop /= Standard_Standard loop
11636 T2 := First_Entity (Scop);
11637 while Present (T2) loop
11638 if Is_Fixed_Point_Type (T2)
11639 and then Current_Entity (T2) = T2
11640 and then Scope (Base_Type (T2)) = Scop
11642 if Present (T1) then
11653 Scop := Scope (Scop);
11656 -- Look for visible fixed type declarations in the context
11658 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
11659 while Present (Item) loop
11660 if Nkind (Item) = N_With_Clause then
11661 Scop := Entity (Name (Item));
11662 T2 := First_Entity (Scop);
11663 while Present (T2) loop
11664 if Is_Fixed_Point_Type (T2)
11665 and then Scope (Base_Type (T2)) = Scop
11666 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
11668 if Present (T1) then
11683 if Nkind (N) = N_Real_Literal then
11685 ("??real literal interpreted as }!", N, T1);
11688 ("??universal_fixed expression interpreted as }!", N, T1);
11692 end Unique_Fixed_Point_Type;
11694 ----------------------
11695 -- Valid_Conversion --
11696 ----------------------
11698 function Valid_Conversion
11700 Target : Entity_Id;
11702 Report_Errs : Boolean := True) return Boolean
11704 Target_Type : constant Entity_Id := Base_Type (Target);
11705 Opnd_Type : Entity_Id := Etype (Operand);
11706 Inc_Ancestor : Entity_Id;
11708 function Conversion_Check
11710 Msg : String) return Boolean;
11711 -- Little routine to post Msg if Valid is False, returns Valid value
11713 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
11714 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11716 procedure Conversion_Error_NE
11718 N : Node_Or_Entity_Id;
11719 E : Node_Or_Entity_Id);
11720 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11722 function Valid_Tagged_Conversion
11723 (Target_Type : Entity_Id;
11724 Opnd_Type : Entity_Id) return Boolean;
11725 -- Specifically test for validity of tagged conversions
11727 function Valid_Array_Conversion return Boolean;
11728 -- Check index and component conformance, and accessibility levels if
11729 -- the component types are anonymous access types (Ada 2005).
11731 ----------------------
11732 -- Conversion_Check --
11733 ----------------------
11735 function Conversion_Check
11737 Msg : String) return Boolean
11742 -- A generic unit has already been analyzed and we have verified
11743 -- that a particular conversion is OK in that context. Since the
11744 -- instance is reanalyzed without relying on the relationships
11745 -- established during the analysis of the generic, it is possible
11746 -- to end up with inconsistent views of private types. Do not emit
11747 -- the error message in such cases. The rest of the machinery in
11748 -- Valid_Conversion still ensures the proper compatibility of
11749 -- target and operand types.
11751 and then not In_Instance
11753 Conversion_Error_N (Msg, Operand);
11757 end Conversion_Check;
11759 ------------------------
11760 -- Conversion_Error_N --
11761 ------------------------
11763 procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
11765 if Report_Errs then
11766 Error_Msg_N (Msg, N);
11768 end Conversion_Error_N;
11770 -------------------------
11771 -- Conversion_Error_NE --
11772 -------------------------
11774 procedure Conversion_Error_NE
11776 N : Node_Or_Entity_Id;
11777 E : Node_Or_Entity_Id)
11780 if Report_Errs then
11781 Error_Msg_NE (Msg, N, E);
11783 end Conversion_Error_NE;
11785 ----------------------------
11786 -- Valid_Array_Conversion --
11787 ----------------------------
11789 function Valid_Array_Conversion return Boolean is
11790 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
11791 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
11793 Opnd_Index : Node_Id;
11794 Opnd_Index_Type : Entity_Id;
11796 Target_Comp_Type : constant Entity_Id :=
11797 Component_Type (Target_Type);
11798 Target_Comp_Base : constant Entity_Id :=
11799 Base_Type (Target_Comp_Type);
11801 Target_Index : Node_Id;
11802 Target_Index_Type : Entity_Id;
11805 -- Error if wrong number of dimensions
11808 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
11811 ("incompatible number of dimensions for conversion", Operand);
11814 -- Number of dimensions matches
11817 -- Loop through indexes of the two arrays
11819 Target_Index := First_Index (Target_Type);
11820 Opnd_Index := First_Index (Opnd_Type);
11821 while Present (Target_Index) and then Present (Opnd_Index) loop
11822 Target_Index_Type := Etype (Target_Index);
11823 Opnd_Index_Type := Etype (Opnd_Index);
11825 -- Error if index types are incompatible
11827 if not (Is_Integer_Type (Target_Index_Type)
11828 and then Is_Integer_Type (Opnd_Index_Type))
11829 and then (Root_Type (Target_Index_Type)
11830 /= Root_Type (Opnd_Index_Type))
11833 ("incompatible index types for array conversion",
11838 Next_Index (Target_Index);
11839 Next_Index (Opnd_Index);
11842 -- If component types have same base type, all set
11844 if Target_Comp_Base = Opnd_Comp_Base then
11847 -- Here if base types of components are not the same. The only
11848 -- time this is allowed is if we have anonymous access types.
11850 -- The conversion of arrays of anonymous access types can lead
11851 -- to dangling pointers. AI-392 formalizes the accessibility
11852 -- checks that must be applied to such conversions to prevent
11853 -- out-of-scope references.
11856 (Target_Comp_Base, E_Anonymous_Access_Type,
11857 E_Anonymous_Access_Subprogram_Type)
11858 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
11860 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
11862 if Type_Access_Level (Target_Type) <
11863 Deepest_Type_Access_Level (Opnd_Type)
11865 if In_Instance_Body then
11866 Error_Msg_Warn := SPARK_Mode /= On;
11868 ("source array type has deeper accessibility "
11869 & "level than target<<", Operand);
11870 Conversion_Error_N ("\Program_Error [<<", Operand);
11872 Make_Raise_Program_Error (Sloc (N),
11873 Reason => PE_Accessibility_Check_Failed));
11874 Set_Etype (N, Target_Type);
11877 -- Conversion not allowed because of accessibility levels
11881 ("source array type has deeper accessibility "
11882 & "level than target", Operand);
11890 -- All other cases where component base types do not match
11894 ("incompatible component types for array conversion",
11899 -- Check that component subtypes statically match. For numeric
11900 -- types this means that both must be either constrained or
11901 -- unconstrained. For enumeration types the bounds must match.
11902 -- All of this is checked in Subtypes_Statically_Match.
11904 if not Subtypes_Statically_Match
11905 (Target_Comp_Type, Opnd_Comp_Type)
11908 ("component subtypes must statically match", Operand);
11914 end Valid_Array_Conversion;
11916 -----------------------------
11917 -- Valid_Tagged_Conversion --
11918 -----------------------------
11920 function Valid_Tagged_Conversion
11921 (Target_Type : Entity_Id;
11922 Opnd_Type : Entity_Id) return Boolean
11925 -- Upward conversions are allowed (RM 4.6(22))
11927 if Covers (Target_Type, Opnd_Type)
11928 or else Is_Ancestor (Target_Type, Opnd_Type)
11932 -- Downward conversion are allowed if the operand is class-wide
11935 elsif Is_Class_Wide_Type (Opnd_Type)
11936 and then Covers (Opnd_Type, Target_Type)
11940 elsif Covers (Opnd_Type, Target_Type)
11941 or else Is_Ancestor (Opnd_Type, Target_Type)
11944 Conversion_Check (False,
11945 "downward conversion of tagged objects not allowed");
11947 -- Ada 2005 (AI-251): The conversion to/from interface types is
11948 -- always valid. The types involved may be class-wide (sub)types.
11950 elsif Is_Interface (Etype (Base_Type (Target_Type)))
11951 or else Is_Interface (Etype (Base_Type (Opnd_Type)))
11955 -- If the operand is a class-wide type obtained through a limited_
11956 -- with clause, and the context includes the nonlimited view, use
11957 -- it to determine whether the conversion is legal.
11959 elsif Is_Class_Wide_Type (Opnd_Type)
11960 and then From_Limited_With (Opnd_Type)
11961 and then Present (Non_Limited_View (Etype (Opnd_Type)))
11962 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
11966 elsif Is_Access_Type (Opnd_Type)
11967 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
11972 Conversion_Error_NE
11973 ("invalid tagged conversion, not compatible with}",
11974 N, First_Subtype (Opnd_Type));
11977 end Valid_Tagged_Conversion;
11979 -- Start of processing for Valid_Conversion
11982 Check_Parameterless_Call (Operand);
11984 if Is_Overloaded (Operand) then
11994 -- Remove procedure calls, which syntactically cannot appear in
11995 -- this context, but which cannot be removed by type checking,
11996 -- because the context does not impose a type.
11998 -- The node may be labelled overloaded, but still contain only one
11999 -- interpretation because others were discarded earlier. If this
12000 -- is the case, retain the single interpretation if legal.
12002 Get_First_Interp (Operand, I, It);
12003 Opnd_Type := It.Typ;
12004 Get_Next_Interp (I, It);
12006 if Present (It.Typ)
12007 and then Opnd_Type /= Standard_Void_Type
12009 -- More than one candidate interpretation is available
12011 Get_First_Interp (Operand, I, It);
12012 while Present (It.Typ) loop
12013 if It.Typ = Standard_Void_Type then
12017 -- When compiling for a system where Address is of a visible
12018 -- integer type, spurious ambiguities can be produced when
12019 -- arithmetic operations have a literal operand and return
12020 -- System.Address or a descendant of it. These ambiguities
12021 -- are usually resolved by the context, but for conversions
12022 -- there is no context type and the removal of the spurious
12023 -- operations must be done explicitly here.
12025 if not Address_Is_Private
12026 and then Is_Descendant_Of_Address (It.Typ)
12031 Get_Next_Interp (I, It);
12035 Get_First_Interp (Operand, I, It);
12039 if No (It.Typ) then
12040 Conversion_Error_N ("illegal operand in conversion", Operand);
12044 Get_Next_Interp (I, It);
12046 if Present (It.Typ) then
12049 It1 := Disambiguate (Operand, I1, I, Any_Type);
12051 if It1 = No_Interp then
12053 ("ambiguous operand in conversion", Operand);
12055 -- If the interpretation involves a standard operator, use
12056 -- the location of the type, which may be user-defined.
12058 if Sloc (It.Nam) = Standard_Location then
12059 Error_Msg_Sloc := Sloc (It.Typ);
12061 Error_Msg_Sloc := Sloc (It.Nam);
12064 Conversion_Error_N -- CODEFIX
12065 ("\\possible interpretation#!", Operand);
12067 if Sloc (N1) = Standard_Location then
12068 Error_Msg_Sloc := Sloc (T1);
12070 Error_Msg_Sloc := Sloc (N1);
12073 Conversion_Error_N -- CODEFIX
12074 ("\\possible interpretation#!", Operand);
12080 Set_Etype (Operand, It1.Typ);
12081 Opnd_Type := It1.Typ;
12085 -- Deal with conversion of integer type to address if the pragma
12086 -- Allow_Integer_Address is in effect. We convert the conversion to
12087 -- an unchecked conversion in this case and we are all done.
12089 if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
12090 Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
12091 Analyze_And_Resolve (N, Target_Type);
12095 -- If we are within a child unit, check whether the type of the
12096 -- expression has an ancestor in a parent unit, in which case it
12097 -- belongs to its derivation class even if the ancestor is private.
12098 -- See RM 7.3.1 (5.2/3).
12100 Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
12104 if Is_Numeric_Type (Target_Type) then
12106 -- A universal fixed expression can be converted to any numeric type
12108 if Opnd_Type = Universal_Fixed then
12111 -- Also no need to check when in an instance or inlined body, because
12112 -- the legality has been established when the template was analyzed.
12113 -- Furthermore, numeric conversions may occur where only a private
12114 -- view of the operand type is visible at the instantiation point.
12115 -- This results in a spurious error if we check that the operand type
12116 -- is a numeric type.
12118 -- Note: in a previous version of this unit, the following tests were
12119 -- applied only for generated code (Comes_From_Source set to False),
12120 -- but in fact the test is required for source code as well, since
12121 -- this situation can arise in source code.
12123 elsif In_Instance or else In_Inlined_Body then
12126 -- Otherwise we need the conversion check
12129 return Conversion_Check
12130 (Is_Numeric_Type (Opnd_Type)
12132 (Present (Inc_Ancestor)
12133 and then Is_Numeric_Type (Inc_Ancestor)),
12134 "illegal operand for numeric conversion");
12139 elsif Is_Array_Type (Target_Type) then
12140 if not Is_Array_Type (Opnd_Type)
12141 or else Opnd_Type = Any_Composite
12142 or else Opnd_Type = Any_String
12145 ("illegal operand for array conversion", Operand);
12149 return Valid_Array_Conversion;
12152 -- Ada 2005 (AI-251): Internally generated conversions of access to
12153 -- interface types added to force the displacement of the pointer to
12154 -- reference the corresponding dispatch table.
12156 elsif not Comes_From_Source (N)
12157 and then Is_Access_Type (Target_Type)
12158 and then Is_Interface (Designated_Type (Target_Type))
12162 -- Ada 2005 (AI-251): Anonymous access types where target references an
12165 elsif Is_Access_Type (Opnd_Type)
12166 and then Ekind_In (Target_Type, E_General_Access_Type,
12167 E_Anonymous_Access_Type)
12168 and then Is_Interface (Directly_Designated_Type (Target_Type))
12170 -- Check the static accessibility rule of 4.6(17). Note that the
12171 -- check is not enforced when within an instance body, since the
12172 -- RM requires such cases to be caught at run time.
12174 -- If the operand is a rewriting of an allocator no check is needed
12175 -- because there are no accessibility issues.
12177 if Nkind (Original_Node (N)) = N_Allocator then
12180 elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
12181 if Type_Access_Level (Opnd_Type) >
12182 Deepest_Type_Access_Level (Target_Type)
12184 -- In an instance, this is a run-time check, but one we know
12185 -- will fail, so generate an appropriate warning. The raise
12186 -- will be generated by Expand_N_Type_Conversion.
12188 if In_Instance_Body then
12189 Error_Msg_Warn := SPARK_Mode /= On;
12191 ("cannot convert local pointer to non-local access type<<",
12193 Conversion_Error_N ("\Program_Error [<<", Operand);
12197 ("cannot convert local pointer to non-local access type",
12202 -- Special accessibility checks are needed in the case of access
12203 -- discriminants declared for a limited type.
12205 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12206 and then not Is_Local_Anonymous_Access (Opnd_Type)
12208 -- When the operand is a selected access discriminant the check
12209 -- needs to be made against the level of the object denoted by
12210 -- the prefix of the selected name (Object_Access_Level handles
12211 -- checking the prefix of the operand for this case).
12213 if Nkind (Operand) = N_Selected_Component
12214 and then Object_Access_Level (Operand) >
12215 Deepest_Type_Access_Level (Target_Type)
12217 -- In an instance, this is a run-time check, but one we know
12218 -- will fail, so generate an appropriate warning. The raise
12219 -- will be generated by Expand_N_Type_Conversion.
12221 if In_Instance_Body then
12222 Error_Msg_Warn := SPARK_Mode /= On;
12224 ("cannot convert access discriminant to non-local "
12225 & "access type<<", Operand);
12226 Conversion_Error_N ("\Program_Error [<<", Operand);
12228 -- Real error if not in instance body
12232 ("cannot convert access discriminant to non-local "
12233 & "access type", Operand);
12238 -- The case of a reference to an access discriminant from
12239 -- within a limited type declaration (which will appear as
12240 -- a discriminal) is always illegal because the level of the
12241 -- discriminant is considered to be deeper than any (nameable)
12244 if Is_Entity_Name (Operand)
12245 and then not Is_Local_Anonymous_Access (Opnd_Type)
12247 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12248 and then Present (Discriminal_Link (Entity (Operand)))
12251 ("discriminant has deeper accessibility level than target",
12260 -- General and anonymous access types
12262 elsif Ekind_In (Target_Type, E_General_Access_Type,
12263 E_Anonymous_Access_Type)
12266 (Is_Access_Type (Opnd_Type)
12268 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
12269 E_Access_Protected_Subprogram_Type),
12270 "must be an access-to-object type")
12272 if Is_Access_Constant (Opnd_Type)
12273 and then not Is_Access_Constant (Target_Type)
12276 ("access-to-constant operand type not allowed", Operand);
12280 -- Check the static accessibility rule of 4.6(17). Note that the
12281 -- check is not enforced when within an instance body, since the RM
12282 -- requires such cases to be caught at run time.
12284 if Ekind (Target_Type) /= E_Anonymous_Access_Type
12285 or else Is_Local_Anonymous_Access (Target_Type)
12286 or else Nkind (Associated_Node_For_Itype (Target_Type)) =
12287 N_Object_Declaration
12289 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12290 -- conversions from an anonymous access type to a named general
12291 -- access type. Such conversions are not allowed in the case of
12292 -- access parameters and stand-alone objects of an anonymous
12293 -- access type. The implicit conversion case is recognized by
12294 -- testing that Comes_From_Source is False and that it's been
12295 -- rewritten. The Comes_From_Source test isn't sufficient because
12296 -- nodes in inlined calls to predefined library routines can have
12297 -- Comes_From_Source set to False. (Is there a better way to test
12298 -- for implicit conversions???)
12300 if Ada_Version >= Ada_2012
12301 and then not Comes_From_Source (N)
12302 and then N /= Original_Node (N)
12303 and then Ekind (Target_Type) = E_General_Access_Type
12304 and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
12306 if Is_Itype (Opnd_Type) then
12308 -- Implicit conversions aren't allowed for objects of an
12309 -- anonymous access type, since such objects have nonstatic
12310 -- levels in Ada 2012.
12312 if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
12313 N_Object_Declaration
12316 ("implicit conversion of stand-alone anonymous "
12317 & "access object not allowed", Operand);
12320 -- Implicit conversions aren't allowed for anonymous access
12321 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12322 -- is done to exclude anonymous access results.
12324 elsif not Is_Local_Anonymous_Access (Opnd_Type)
12325 and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
12326 N_Function_Specification,
12327 N_Procedure_Specification)
12330 ("implicit conversion of anonymous access formal "
12331 & "not allowed", Operand);
12334 -- This is a case where there's an enclosing object whose
12335 -- to which the "statically deeper than" relationship does
12336 -- not apply (such as an access discriminant selected from
12337 -- a dereference of an access parameter).
12339 elsif Object_Access_Level (Operand)
12340 = Scope_Depth (Standard_Standard)
12343 ("implicit conversion of anonymous access value "
12344 & "not allowed", Operand);
12347 -- In other cases, the level of the operand's type must be
12348 -- statically less deep than that of the target type, else
12349 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12351 elsif Type_Access_Level (Opnd_Type) >
12352 Deepest_Type_Access_Level (Target_Type)
12355 ("implicit conversion of anonymous access value "
12356 & "violates accessibility", Operand);
12361 elsif Type_Access_Level (Opnd_Type) >
12362 Deepest_Type_Access_Level (Target_Type)
12364 -- In an instance, this is a run-time check, but one we know
12365 -- will fail, so generate an appropriate warning. The raise
12366 -- will be generated by Expand_N_Type_Conversion.
12368 if In_Instance_Body then
12369 Error_Msg_Warn := SPARK_Mode /= On;
12371 ("cannot convert local pointer to non-local access type<<",
12373 Conversion_Error_N ("\Program_Error [<<", Operand);
12375 -- If not in an instance body, this is a real error
12378 -- Avoid generation of spurious error message
12380 if not Error_Posted (N) then
12382 ("cannot convert local pointer to non-local access type",
12389 -- Special accessibility checks are needed in the case of access
12390 -- discriminants declared for a limited type.
12392 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
12393 and then not Is_Local_Anonymous_Access (Opnd_Type)
12395 -- When the operand is a selected access discriminant the check
12396 -- needs to be made against the level of the object denoted by
12397 -- the prefix of the selected name (Object_Access_Level handles
12398 -- checking the prefix of the operand for this case).
12400 if Nkind (Operand) = N_Selected_Component
12401 and then Object_Access_Level (Operand) >
12402 Deepest_Type_Access_Level (Target_Type)
12404 -- In an instance, this is a run-time check, but one we know
12405 -- will fail, so generate an appropriate warning. The raise
12406 -- will be generated by Expand_N_Type_Conversion.
12408 if In_Instance_Body then
12409 Error_Msg_Warn := SPARK_Mode /= On;
12411 ("cannot convert access discriminant to non-local "
12412 & "access type<<", Operand);
12413 Conversion_Error_N ("\Program_Error [<<", Operand);
12415 -- If not in an instance body, this is a real error
12419 ("cannot convert access discriminant to non-local "
12420 & "access type", Operand);
12425 -- The case of a reference to an access discriminant from
12426 -- within a limited type declaration (which will appear as
12427 -- a discriminal) is always illegal because the level of the
12428 -- discriminant is considered to be deeper than any (nameable)
12431 if Is_Entity_Name (Operand)
12433 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
12434 and then Present (Discriminal_Link (Entity (Operand)))
12437 ("discriminant has deeper accessibility level than target",
12444 -- In the presence of limited_with clauses we have to use nonlimited
12445 -- views, if available.
12447 Check_Limited : declare
12448 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
12449 -- Helper function to handle limited views
12451 --------------------------
12452 -- Full_Designated_Type --
12453 --------------------------
12455 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
12456 Desig : constant Entity_Id := Designated_Type (T);
12459 -- Handle the limited view of a type
12461 if From_Limited_With (Desig)
12462 and then Has_Non_Limited_View (Desig)
12464 return Available_View (Desig);
12468 end Full_Designated_Type;
12470 -- Local Declarations
12472 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
12473 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
12475 Same_Base : constant Boolean :=
12476 Base_Type (Target) = Base_Type (Opnd);
12478 -- Start of processing for Check_Limited
12481 if Is_Tagged_Type (Target) then
12482 return Valid_Tagged_Conversion (Target, Opnd);
12485 if not Same_Base then
12486 Conversion_Error_NE
12487 ("target designated type not compatible with }",
12488 N, Base_Type (Opnd));
12491 -- Ada 2005 AI-384: legality rule is symmetric in both
12492 -- designated types. The conversion is legal (with possible
12493 -- constraint check) if either designated type is
12496 elsif Subtypes_Statically_Match (Target, Opnd)
12498 (Has_Discriminants (Target)
12500 (not Is_Constrained (Opnd)
12501 or else not Is_Constrained (Target)))
12503 -- Special case, if Value_Size has been used to make the
12504 -- sizes different, the conversion is not allowed even
12505 -- though the subtypes statically match.
12507 if Known_Static_RM_Size (Target)
12508 and then Known_Static_RM_Size (Opnd)
12509 and then RM_Size (Target) /= RM_Size (Opnd)
12511 Conversion_Error_NE
12512 ("target designated subtype not compatible with }",
12514 Conversion_Error_NE
12515 ("\because sizes of the two designated subtypes differ",
12519 -- Normal case where conversion is allowed
12527 ("target designated subtype not compatible with }",
12534 -- Access to subprogram types. If the operand is an access parameter,
12535 -- the type has a deeper accessibility that any master, and cannot be
12536 -- assigned. We must make an exception if the conversion is part of an
12537 -- assignment and the target is the return object of an extended return
12538 -- statement, because in that case the accessibility check takes place
12539 -- after the return.
12541 elsif Is_Access_Subprogram_Type (Target_Type)
12543 -- Note: this test of Opnd_Type is there to prevent entering this
12544 -- branch in the case of a remote access to subprogram type, which
12545 -- is internally represented as an E_Record_Type.
12547 and then Is_Access_Type (Opnd_Type)
12549 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
12550 and then Is_Entity_Name (Operand)
12551 and then Ekind (Entity (Operand)) = E_In_Parameter
12553 (Nkind (Parent (N)) /= N_Assignment_Statement
12554 or else not Is_Entity_Name (Name (Parent (N)))
12555 or else not Is_Return_Object (Entity (Name (Parent (N)))))
12558 ("illegal attempt to store anonymous access to subprogram",
12561 ("\value has deeper accessibility than any master "
12562 & "(RM 3.10.2 (13))",
12566 ("\use named access type for& instead of access parameter",
12567 Operand, Entity (Operand));
12570 -- Check that the designated types are subtype conformant
12572 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
12573 Old_Id => Designated_Type (Opnd_Type),
12576 -- Check the static accessibility rule of 4.6(20)
12578 if Type_Access_Level (Opnd_Type) >
12579 Deepest_Type_Access_Level (Target_Type)
12582 ("operand type has deeper accessibility level than target",
12585 -- Check that if the operand type is declared in a generic body,
12586 -- then the target type must be declared within that same body
12587 -- (enforces last sentence of 4.6(20)).
12589 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
12591 O_Gen : constant Node_Id :=
12592 Enclosing_Generic_Body (Opnd_Type);
12597 T_Gen := Enclosing_Generic_Body (Target_Type);
12598 while Present (T_Gen) and then T_Gen /= O_Gen loop
12599 T_Gen := Enclosing_Generic_Body (T_Gen);
12602 if T_Gen /= O_Gen then
12604 ("target type must be declared in same generic body "
12605 & "as operand type", N);
12612 -- Remote access to subprogram types
12614 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
12615 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
12617 -- It is valid to convert from one RAS type to another provided
12618 -- that their specification statically match.
12620 -- Note: at this point, remote access to subprogram types have been
12621 -- expanded to their E_Record_Type representation, and we need to
12622 -- go back to the original access type definition using the
12623 -- Corresponding_Remote_Type attribute in order to check that the
12624 -- designated profiles match.
12626 pragma Assert (Ekind (Target_Type) = E_Record_Type);
12627 pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
12629 Check_Subtype_Conformant
12631 Designated_Type (Corresponding_Remote_Type (Target_Type)),
12633 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
12638 -- If it was legal in the generic, it's legal in the instance
12640 elsif In_Instance_Body then
12643 -- If both are tagged types, check legality of view conversions
12645 elsif Is_Tagged_Type (Target_Type)
12647 Is_Tagged_Type (Opnd_Type)
12649 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
12651 -- Types derived from the same root type are convertible
12653 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
12656 -- In an instance or an inlined body, there may be inconsistent views of
12657 -- the same type, or of types derived from a common root.
12659 elsif (In_Instance or In_Inlined_Body)
12661 Root_Type (Underlying_Type (Target_Type)) =
12662 Root_Type (Underlying_Type (Opnd_Type))
12666 -- Special check for common access type error case
12668 elsif Ekind (Target_Type) = E_Access_Type
12669 and then Is_Access_Type (Opnd_Type)
12671 Conversion_Error_N ("target type must be general access type!", N);
12672 Conversion_Error_NE -- CODEFIX
12673 ("add ALL to }!", N, Target_Type);
12676 -- Here we have a real conversion error
12679 Conversion_Error_NE
12680 ("invalid conversion, not compatible with }", N, Opnd_Type);
12683 end Valid_Conversion;