1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 Elists; use Elists;
32 with Errout; use Errout;
33 with Expander; use Expander;
34 with Exp_Disp; use Exp_Disp;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Tss; use Exp_Tss;
38 with Exp_Util; use Exp_Util;
39 with Fname; use Fname;
40 with Freeze; use Freeze;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch4; use Sem_Ch4;
58 with Sem_Ch6; use Sem_Ch6;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Elab; use Sem_Elab;
64 with Sem_Eval; use Sem_Eval;
65 with Sem_Intr; use Sem_Intr;
66 with Sem_Util; use Sem_Util;
67 with Sem_Type; use Sem_Type;
68 with Sem_Warn; use Sem_Warn;
69 with Sinfo; use Sinfo;
70 with Snames; use Snames;
71 with Stand; use Stand;
72 with Stringt; use Stringt;
73 with Style; use Style;
74 with Targparm; use Targparm;
75 with Tbuild; use Tbuild;
76 with Uintp; use Uintp;
77 with Urealp; use Urealp;
79 package body Sem_Res is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the
87 -- type information recursively to the descendants of N. If the node
88 -- is not overloaded, its Etype is established in the first pass. If
89 -- overloaded, the Resolve routines set the correct type. For arith.
90 -- operators, the Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 procedure Check_Discriminant_Use (N : Node_Id);
95 -- Enforce the restrictions on the use of discriminants when constraining
96 -- a component of a discriminated type (record or concurrent type).
98 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
99 -- Given a node for an operator associated with type T, check that
100 -- the operator is visible. Operators all of whose operands are
101 -- universal must be checked for visibility during resolution
102 -- because their type is not determinable based on their operands.
104 procedure Check_Fully_Declared_Prefix
107 -- Check that the type of the prefix of a dereference is not incomplete
109 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
110 -- Given a call node, N, which is known to occur immediately within the
111 -- subprogram being called, determines whether it is a detectable case of
112 -- an infinite recursion, and if so, outputs appropriate messages. Returns
113 -- True if an infinite recursion is detected, and False otherwise.
115 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
116 -- If the type of the object being initialized uses the secondary stack
117 -- directly or indirectly, create a transient scope for the call to the
118 -- init proc. This is because we do not create transient scopes for the
119 -- initialization of individual components within the init proc itself.
120 -- Could be optimized away perhaps?
122 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
123 -- Determine whether E is an access type declared by an access
124 -- declaration, and not an (anonymous) allocator type.
126 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
127 -- Utility to check whether the name in the call is a predefined
128 -- operator, in which case the call is made into an operator node.
129 -- An instance of an intrinsic conversion operation may be given
130 -- an operator name, but is not treated like an operator.
132 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
133 -- If a default expression in entry call N depends on the discriminants
134 -- of the task, it must be replaced with a reference to the discriminant
135 -- of the task being called.
137 procedure Resolve_Op_Concat_Arg
142 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
143 -- concatenation operator. The operand is either of the array type or of
144 -- the component type. If the operand is an aggregate, and the component
145 -- type is composite, this is ambiguous if component type has aggregates.
147 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
148 -- Does the first part of the work of Resolve_Op_Concat
150 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
151 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
152 -- has been resolved. See Resolve_Op_Concat for details.
154 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
155 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
156 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
157 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
158 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
159 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
164 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
165 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
166 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
187 function Operator_Kind
189 Is_Binary : Boolean) return Node_Kind;
190 -- Utility to map the name of an operator into the corresponding Node. Used
191 -- by other node rewriting procedures.
193 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
194 -- Resolve actuals of call, and add default expressions for missing ones.
195 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
196 -- called subprogram.
198 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
199 -- Called from Resolve_Call, when the prefix denotes an entry or element
200 -- of entry family. Actuals are resolved as for subprograms, and the node
201 -- is rebuilt as an entry call. Also called for protected operations. Typ
202 -- is the context type, which is used when the operation is a protected
203 -- function with no arguments, and the return value is indexed.
205 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
206 -- A call to a user-defined intrinsic operator is rewritten as a call
207 -- to the corresponding predefined operator, with suitable conversions.
209 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
210 -- Ditto, for unary operators (only arithmetic ones)
212 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
213 -- If an operator node resolves to a call to a user-defined operator,
214 -- rewrite the node as a function call.
216 procedure Make_Call_Into_Operator
220 -- Inverse transformation: if an operator is given in functional notation,
221 -- then after resolving the node, transform into an operator node, so
222 -- that operands are resolved properly. Recall that predefined operators
223 -- do not have a full signature and special resolution rules apply.
225 procedure Rewrite_Renamed_Operator
229 -- An operator can rename another, e.g. in an instantiation. In that
230 -- case, the proper operator node must be constructed and resolved.
232 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
233 -- The String_Literal_Subtype is built for all strings that are not
234 -- operands of a static concatenation operation. If the argument is
235 -- not a N_String_Literal node, then the call has no effect.
237 procedure Set_Slice_Subtype (N : Node_Id);
238 -- Build subtype of array type, with the range specified by the slice
240 procedure Simplify_Type_Conversion (N : Node_Id);
241 -- Called after N has been resolved and evaluated, but before range checks
242 -- have been applied. Currently simplifies a combination of floating-point
243 -- to integer conversion and Truncation attribute.
245 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
246 -- A universal_fixed expression in an universal context is unambiguous
247 -- if there is only one applicable fixed point type. Determining whether
248 -- there is only one requires a search over all visible entities, and
249 -- happens only in very pathological cases (see 6115-006).
251 function Valid_Conversion
254 Operand : Node_Id) return Boolean;
255 -- Verify legality rules given in 4.6 (8-23). Target is the target
256 -- type of the conversion, which may be an implicit conversion of
257 -- an actual parameter to an anonymous access type (in which case
258 -- N denotes the actual parameter and N = Operand).
260 -------------------------
261 -- Ambiguous_Character --
262 -------------------------
264 procedure Ambiguous_Character (C : Node_Id) is
268 if Nkind (C) = N_Character_Literal then
269 Error_Msg_N ("ambiguous character literal", C);
271 -- First the ones in Standard
274 ("\\possible interpretation: Character!", C);
276 ("\\possible interpretation: Wide_Character!", C);
278 -- Include Wide_Wide_Character in Ada 2005 mode
280 if Ada_Version >= Ada_05 then
282 ("\\possible interpretation: Wide_Wide_Character!", C);
285 -- Now any other types that match
287 E := Current_Entity (C);
288 while Present (E) loop
289 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
293 end Ambiguous_Character;
295 -------------------------
296 -- Analyze_And_Resolve --
297 -------------------------
299 procedure Analyze_And_Resolve (N : Node_Id) is
303 end Analyze_And_Resolve;
305 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
309 end Analyze_And_Resolve;
311 -- Version withs check(s) suppressed
313 procedure Analyze_And_Resolve
318 Scop : constant Entity_Id := Current_Scope;
321 if Suppress = All_Checks then
323 Svg : constant Suppress_Array := Scope_Suppress;
325 Scope_Suppress := (others => True);
326 Analyze_And_Resolve (N, Typ);
327 Scope_Suppress := Svg;
332 Svg : constant Boolean := Scope_Suppress (Suppress);
335 Scope_Suppress (Suppress) := True;
336 Analyze_And_Resolve (N, Typ);
337 Scope_Suppress (Suppress) := Svg;
341 if Current_Scope /= Scop
342 and then Scope_Is_Transient
344 -- This can only happen if a transient scope was created
345 -- for an inner expression, which will be removed upon
346 -- completion of the analysis of an enclosing construct.
347 -- The transient scope must have the suppress status of
348 -- the enclosing environment, not of this Analyze call.
350 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
353 end Analyze_And_Resolve;
355 procedure Analyze_And_Resolve
359 Scop : constant Entity_Id := Current_Scope;
362 if Suppress = All_Checks then
364 Svg : constant Suppress_Array := Scope_Suppress;
366 Scope_Suppress := (others => True);
367 Analyze_And_Resolve (N);
368 Scope_Suppress := Svg;
373 Svg : constant Boolean := Scope_Suppress (Suppress);
376 Scope_Suppress (Suppress) := True;
377 Analyze_And_Resolve (N);
378 Scope_Suppress (Suppress) := Svg;
382 if Current_Scope /= Scop
383 and then Scope_Is_Transient
385 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
388 end Analyze_And_Resolve;
390 ----------------------------
391 -- Check_Discriminant_Use --
392 ----------------------------
394 procedure Check_Discriminant_Use (N : Node_Id) is
395 PN : constant Node_Id := Parent (N);
396 Disc : constant Entity_Id := Entity (N);
401 -- Any use in a spec-expression is legal
403 if In_Spec_Expression then
406 elsif Nkind (PN) = N_Range then
408 -- Discriminant cannot be used to constrain a scalar type
412 if Nkind (P) = N_Range_Constraint
413 and then Nkind (Parent (P)) = N_Subtype_Indication
414 and then Nkind (Parent (Parent (P))) = N_Component_Definition
416 Error_Msg_N ("discriminant cannot constrain scalar type", N);
418 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
420 -- The following check catches the unusual case where
421 -- a discriminant appears within an index constraint
422 -- that is part of a larger expression within a constraint
423 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
424 -- For now we only check case of record components, and
425 -- note that a similar check should also apply in the
426 -- case of discriminant constraints below. ???
428 -- Note that the check for N_Subtype_Declaration below is to
429 -- detect the valid use of discriminants in the constraints of a
430 -- subtype declaration when this subtype declaration appears
431 -- inside the scope of a record type (which is syntactically
432 -- illegal, but which may be created as part of derived type
433 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
436 if Ekind (Current_Scope) = E_Record_Type
437 and then Scope (Disc) = Current_Scope
439 (Nkind (Parent (P)) = N_Subtype_Indication
441 Nkind_In (Parent (Parent (P)), N_Component_Definition,
442 N_Subtype_Declaration)
443 and then Paren_Count (N) = 0)
446 ("discriminant must appear alone in component constraint", N);
450 -- Detect a common error:
452 -- type R (D : Positive := 100) is record
453 -- Name : String (1 .. D);
456 -- The default value causes an object of type R to be allocated
457 -- with room for Positive'Last characters. The RM does not mandate
458 -- the allocation of the maximum size, but that is what GNAT does
459 -- so we should warn the programmer that there is a problem.
461 Check_Large : declare
467 function Large_Storage_Type (T : Entity_Id) return Boolean;
468 -- Return True if type T has a large enough range that
469 -- any array whose index type covered the whole range of
470 -- the type would likely raise Storage_Error.
472 ------------------------
473 -- Large_Storage_Type --
474 ------------------------
476 function Large_Storage_Type (T : Entity_Id) return Boolean is
478 -- The type is considered large if its bounds are known at
479 -- compile time and if it requires at least as many bits as
480 -- a Positive to store the possible values.
482 return Compile_Time_Known_Value (Type_Low_Bound (T))
483 and then Compile_Time_Known_Value (Type_High_Bound (T))
485 Minimum_Size (T, Biased => True) >=
486 RM_Size (Standard_Positive);
487 end Large_Storage_Type;
489 -- Start of processing for Check_Large
492 -- Check that the Disc has a large range
494 if not Large_Storage_Type (Etype (Disc)) then
498 -- If the enclosing type is limited, we allocate only the
499 -- default value, not the maximum, and there is no need for
502 if Is_Limited_Type (Scope (Disc)) then
506 -- Check that it is the high bound
508 if N /= High_Bound (PN)
509 or else No (Discriminant_Default_Value (Disc))
514 -- Check the array allows a large range at this bound.
515 -- First find the array
519 if Nkind (SI) /= N_Subtype_Indication then
523 T := Entity (Subtype_Mark (SI));
525 if not Is_Array_Type (T) then
529 -- Next, find the dimension
531 TB := First_Index (T);
532 CB := First (Constraints (P));
534 and then Present (TB)
535 and then Present (CB)
546 -- Now, check the dimension has a large range
548 if not Large_Storage_Type (Etype (TB)) then
552 -- Warn about the danger
555 ("?creation of & object may raise Storage_Error!",
564 -- Legal case is in index or discriminant constraint
566 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
567 N_Discriminant_Association)
569 if Paren_Count (N) > 0 then
571 ("discriminant in constraint must appear alone", N);
573 elsif Nkind (N) = N_Expanded_Name
574 and then Comes_From_Source (N)
577 ("discriminant must appear alone as a direct name", N);
582 -- Otherwise, context is an expression. It should not be within
583 -- (i.e. a subexpression of) a constraint for a component.
588 while not Nkind_In (P, N_Component_Declaration,
589 N_Subtype_Indication,
597 -- If the discriminant is used in an expression that is a bound
598 -- of a scalar type, an Itype is created and the bounds are attached
599 -- to its range, not to the original subtype indication. Such use
600 -- is of course a double fault.
602 if (Nkind (P) = N_Subtype_Indication
603 and then Nkind_In (Parent (P), N_Component_Definition,
604 N_Derived_Type_Definition)
605 and then D = Constraint (P))
607 -- The constraint itself may be given by a subtype indication,
608 -- rather than by a more common discrete range.
610 or else (Nkind (P) = N_Subtype_Indication
612 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
613 or else Nkind (P) = N_Entry_Declaration
614 or else Nkind (D) = N_Defining_Identifier
617 ("discriminant in constraint must appear alone", N);
620 end Check_Discriminant_Use;
622 --------------------------------
623 -- Check_For_Visible_Operator --
624 --------------------------------
626 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
628 if Is_Invisible_Operator (N, T) then
630 ("operator for} is not directly visible!", N, First_Subtype (T));
631 Error_Msg_N ("use clause would make operation legal!", N);
633 end Check_For_Visible_Operator;
635 ----------------------------------
636 -- Check_Fully_Declared_Prefix --
637 ----------------------------------
639 procedure Check_Fully_Declared_Prefix
644 -- Check that the designated type of the prefix of a dereference is
645 -- not an incomplete type. This cannot be done unconditionally, because
646 -- dereferences of private types are legal in default expressions. This
647 -- case is taken care of in Check_Fully_Declared, called below. There
648 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
650 -- This consideration also applies to similar checks for allocators,
651 -- qualified expressions, and type conversions.
653 -- An additional exception concerns other per-object expressions that
654 -- are not directly related to component declarations, in particular
655 -- representation pragmas for tasks. These will be per-object
656 -- expressions if they depend on discriminants or some global entity.
657 -- If the task has access discriminants, the designated type may be
658 -- incomplete at the point the expression is resolved. This resolution
659 -- takes place within the body of the initialization procedure, where
660 -- the discriminant is replaced by its discriminal.
662 if Is_Entity_Name (Pref)
663 and then Ekind (Entity (Pref)) = E_In_Parameter
667 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
668 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
669 -- Analyze_Object_Renaming, and Freeze_Entity.
671 elsif Ada_Version >= Ada_05
672 and then Is_Entity_Name (Pref)
673 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
675 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
679 Check_Fully_Declared (Typ, Parent (Pref));
681 end Check_Fully_Declared_Prefix;
683 ------------------------------
684 -- Check_Infinite_Recursion --
685 ------------------------------
687 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
691 function Same_Argument_List return Boolean;
692 -- Check whether list of actuals is identical to list of formals
693 -- of called function (which is also the enclosing scope).
695 ------------------------
696 -- Same_Argument_List --
697 ------------------------
699 function Same_Argument_List return Boolean is
705 if not Is_Entity_Name (Name (N)) then
708 Subp := Entity (Name (N));
711 F := First_Formal (Subp);
712 A := First_Actual (N);
713 while Present (F) and then Present (A) loop
714 if not Is_Entity_Name (A)
715 or else Entity (A) /= F
725 end Same_Argument_List;
727 -- Start of processing for Check_Infinite_Recursion
730 -- Special case, if this is a procedure call and is a call to the
731 -- current procedure with the same argument list, then this is for
732 -- sure an infinite recursion and we insert a call to raise SE.
734 if Is_List_Member (N)
735 and then List_Length (List_Containing (N)) = 1
736 and then Same_Argument_List
739 P : constant Node_Id := Parent (N);
741 if Nkind (P) = N_Handled_Sequence_Of_Statements
742 and then Nkind (Parent (P)) = N_Subprogram_Body
743 and then Is_Empty_List (Declarations (Parent (P)))
745 Error_Msg_N ("!?infinite recursion", N);
746 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
748 Make_Raise_Storage_Error (Sloc (N),
749 Reason => SE_Infinite_Recursion));
755 -- If not that special case, search up tree, quitting if we reach a
756 -- construct (e.g. a conditional) that tells us that this is not a
757 -- case for an infinite recursion warning.
763 -- If no parent, then we were not inside a subprogram, this can for
764 -- example happen when processing certain pragmas in a spec. Just
765 -- return False in this case.
771 -- Done if we get to subprogram body, this is definitely an infinite
772 -- recursion case if we did not find anything to stop us.
774 exit when Nkind (P) = N_Subprogram_Body;
776 -- If appearing in conditional, result is false
778 if Nkind_In (P, N_Or_Else,
785 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
786 and then C /= First (Statements (P))
788 -- If the call is the expression of a return statement and the
789 -- actuals are identical to the formals, it's worth a warning.
790 -- However, we skip this if there is an immediately preceding
791 -- raise statement, since the call is never executed.
793 -- Furthermore, this corresponds to a common idiom:
795 -- function F (L : Thing) return Boolean is
797 -- raise Program_Error;
801 -- for generating a stub function
803 if Nkind (Parent (N)) = N_Simple_Return_Statement
804 and then Same_Argument_List
806 exit when not Is_List_Member (Parent (N));
808 -- OK, return statement is in a statement list, look for raise
814 -- Skip past N_Freeze_Entity nodes generated by expansion
816 Nod := Prev (Parent (N));
818 and then Nkind (Nod) = N_Freeze_Entity
823 -- If no raise statement, give warning
825 exit when Nkind (Nod) /= N_Raise_Statement
827 (Nkind (Nod) not in N_Raise_xxx_Error
828 or else Present (Condition (Nod)));
839 Error_Msg_N ("!?possible infinite recursion", N);
840 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
843 end Check_Infinite_Recursion;
845 -------------------------------
846 -- Check_Initialization_Call --
847 -------------------------------
849 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
850 Typ : constant Entity_Id := Etype (First_Formal (Nam));
852 function Uses_SS (T : Entity_Id) return Boolean;
853 -- Check whether the creation of an object of the type will involve
854 -- use of the secondary stack. If T is a record type, this is true
855 -- if the expression for some component uses the secondary stack, e.g.
856 -- through a call to a function that returns an unconstrained value.
857 -- False if T is controlled, because cleanups occur elsewhere.
863 function Uses_SS (T : Entity_Id) return Boolean is
866 Full_Type : Entity_Id := Underlying_Type (T);
869 -- Normally we want to use the underlying type, but if it's not set
870 -- then continue with T.
872 if not Present (Full_Type) then
876 if Is_Controlled (Full_Type) then
879 elsif Is_Array_Type (Full_Type) then
880 return Uses_SS (Component_Type (Full_Type));
882 elsif Is_Record_Type (Full_Type) then
883 Comp := First_Component (Full_Type);
884 while Present (Comp) loop
885 if Ekind (Comp) = E_Component
886 and then Nkind (Parent (Comp)) = N_Component_Declaration
888 -- The expression for a dynamic component may be rewritten
889 -- as a dereference, so retrieve original node.
891 Expr := Original_Node (Expression (Parent (Comp)));
893 -- Return True if the expression is a call to a function
894 -- (including an attribute function such as Image) with
895 -- a result that requires a transient scope.
897 if (Nkind (Expr) = N_Function_Call
898 or else (Nkind (Expr) = N_Attribute_Reference
899 and then Present (Expressions (Expr))))
900 and then Requires_Transient_Scope (Etype (Expr))
904 elsif Uses_SS (Etype (Comp)) then
909 Next_Component (Comp);
919 -- Start of processing for Check_Initialization_Call
922 -- Establish a transient scope if the type needs it
924 if Uses_SS (Typ) then
925 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
927 end Check_Initialization_Call;
929 ------------------------------
930 -- Check_Parameterless_Call --
931 ------------------------------
933 procedure Check_Parameterless_Call (N : Node_Id) is
936 function Prefix_Is_Access_Subp return Boolean;
937 -- If the prefix is of an access_to_subprogram type, the node must be
938 -- rewritten as a call. Ditto if the prefix is overloaded and all its
939 -- interpretations are access to subprograms.
941 ---------------------------
942 -- Prefix_Is_Access_Subp --
943 ---------------------------
945 function Prefix_Is_Access_Subp return Boolean is
950 if not Is_Overloaded (N) then
952 Ekind (Etype (N)) = E_Subprogram_Type
953 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
955 Get_First_Interp (N, I, It);
956 while Present (It.Typ) loop
957 if Ekind (It.Typ) /= E_Subprogram_Type
958 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
963 Get_Next_Interp (I, It);
968 end Prefix_Is_Access_Subp;
970 -- Start of processing for Check_Parameterless_Call
973 -- Defend against junk stuff if errors already detected
975 if Total_Errors_Detected /= 0 then
976 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
978 elsif Nkind (N) in N_Has_Chars
979 and then Chars (N) in Error_Name_Or_No_Name
987 -- If the context expects a value, and the name is a procedure, this is
988 -- most likely a missing 'Access. Don't try to resolve the parameterless
989 -- call, error will be caught when the outer call is analyzed.
991 if Is_Entity_Name (N)
992 and then Ekind (Entity (N)) = E_Procedure
993 and then not Is_Overloaded (N)
995 Nkind_In (Parent (N), N_Parameter_Association,
997 N_Procedure_Call_Statement)
1002 -- Rewrite as call if overloadable entity that is (or could be, in the
1003 -- overloaded case) a function call. If we know for sure that the entity
1004 -- is an enumeration literal, we do not rewrite it.
1006 if (Is_Entity_Name (N)
1007 and then Is_Overloadable (Entity (N))
1008 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1009 or else Is_Overloaded (N)))
1011 -- Rewrite as call if it is an explicit deference of an expression of
1012 -- a subprogram access type, and the subprogram type is not that of a
1013 -- procedure or entry.
1016 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1018 -- Rewrite as call if it is a selected component which is a function,
1019 -- this is the case of a call to a protected function (which may be
1020 -- overloaded with other protected operations).
1023 (Nkind (N) = N_Selected_Component
1024 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1026 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1028 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1029 and then Is_Overloaded (Selector_Name (N)))))
1031 -- If one of the above three conditions is met, rewrite as call.
1032 -- Apply the rewriting only once.
1035 if Nkind (Parent (N)) /= N_Function_Call
1036 or else N /= Name (Parent (N))
1038 Nam := New_Copy (N);
1040 -- If overloaded, overload set belongs to new copy
1042 Save_Interps (N, Nam);
1044 -- Change node to parameterless function call (note that the
1045 -- Parameter_Associations associations field is left set to Empty,
1046 -- its normal default value since there are no parameters)
1048 Change_Node (N, N_Function_Call);
1050 Set_Sloc (N, Sloc (Nam));
1054 elsif Nkind (N) = N_Parameter_Association then
1055 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1057 end Check_Parameterless_Call;
1059 -----------------------------
1060 -- Is_Definite_Access_Type --
1061 -----------------------------
1063 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1064 Btyp : constant Entity_Id := Base_Type (E);
1066 return Ekind (Btyp) = E_Access_Type
1067 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1068 and then Comes_From_Source (Btyp));
1069 end Is_Definite_Access_Type;
1071 ----------------------
1072 -- Is_Predefined_Op --
1073 ----------------------
1075 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1077 return Is_Intrinsic_Subprogram (Nam)
1078 and then not Is_Generic_Instance (Nam)
1079 and then Chars (Nam) in Any_Operator_Name
1080 and then (No (Alias (Nam))
1081 or else Is_Predefined_Op (Alias (Nam)));
1082 end Is_Predefined_Op;
1084 -----------------------------
1085 -- Make_Call_Into_Operator --
1086 -----------------------------
1088 procedure Make_Call_Into_Operator
1093 Op_Name : constant Name_Id := Chars (Op_Id);
1094 Act1 : Node_Id := First_Actual (N);
1095 Act2 : Node_Id := Next_Actual (Act1);
1096 Error : Boolean := False;
1097 Func : constant Entity_Id := Entity (Name (N));
1098 Is_Binary : constant Boolean := Present (Act2);
1100 Opnd_Type : Entity_Id;
1101 Orig_Type : Entity_Id := Empty;
1104 type Kind_Test is access function (E : Entity_Id) return Boolean;
1106 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1107 -- If the operand is not universal, and the operator is given by a
1108 -- expanded name, verify that the operand has an interpretation with
1109 -- a type defined in the given scope of the operator.
1111 function Type_In_P (Test : Kind_Test) return Entity_Id;
1112 -- Find a type of the given class in the package Pack that contains
1115 ---------------------------
1116 -- Operand_Type_In_Scope --
1117 ---------------------------
1119 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1120 Nod : constant Node_Id := Right_Opnd (Op_Node);
1125 if not Is_Overloaded (Nod) then
1126 return Scope (Base_Type (Etype (Nod))) = S;
1129 Get_First_Interp (Nod, I, It);
1130 while Present (It.Typ) loop
1131 if Scope (Base_Type (It.Typ)) = S then
1135 Get_Next_Interp (I, It);
1140 end Operand_Type_In_Scope;
1146 function Type_In_P (Test : Kind_Test) return Entity_Id is
1149 function In_Decl return Boolean;
1150 -- Verify that node is not part of the type declaration for the
1151 -- candidate type, which would otherwise be invisible.
1157 function In_Decl return Boolean is
1158 Decl_Node : constant Node_Id := Parent (E);
1164 if Etype (E) = Any_Type then
1167 elsif No (Decl_Node) then
1172 and then Nkind (N2) /= N_Compilation_Unit
1174 if N2 = Decl_Node then
1185 -- Start of processing for Type_In_P
1188 -- If the context type is declared in the prefix package, this
1189 -- is the desired base type.
1191 if Scope (Base_Type (Typ)) = Pack
1194 return Base_Type (Typ);
1197 E := First_Entity (Pack);
1198 while Present (E) loop
1200 and then not In_Decl
1212 -- Start of processing for Make_Call_Into_Operator
1215 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1220 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1221 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1222 Save_Interps (Act1, Left_Opnd (Op_Node));
1223 Save_Interps (Act2, Right_Opnd (Op_Node));
1224 Act1 := Left_Opnd (Op_Node);
1225 Act2 := Right_Opnd (Op_Node);
1230 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1231 Save_Interps (Act1, Right_Opnd (Op_Node));
1232 Act1 := Right_Opnd (Op_Node);
1235 -- If the operator is denoted by an expanded name, and the prefix is
1236 -- not Standard, but the operator is a predefined one whose scope is
1237 -- Standard, then this is an implicit_operator, inserted as an
1238 -- interpretation by the procedure of the same name. This procedure
1239 -- overestimates the presence of implicit operators, because it does
1240 -- not examine the type of the operands. Verify now that the operand
1241 -- type appears in the given scope. If right operand is universal,
1242 -- check the other operand. In the case of concatenation, either
1243 -- argument can be the component type, so check the type of the result.
1244 -- If both arguments are literals, look for a type of the right kind
1245 -- defined in the given scope. This elaborate nonsense is brought to
1246 -- you courtesy of b33302a. The type itself must be frozen, so we must
1247 -- find the type of the proper class in the given scope.
1249 -- A final wrinkle is the multiplication operator for fixed point
1250 -- types, which is defined in Standard only, and not in the scope of
1251 -- the fixed_point type itself.
1253 if Nkind (Name (N)) = N_Expanded_Name then
1254 Pack := Entity (Prefix (Name (N)));
1256 -- If the entity being called is defined in the given package,
1257 -- it is a renaming of a predefined operator, and known to be
1260 if Scope (Entity (Name (N))) = Pack
1261 and then Pack /= Standard_Standard
1265 -- Visibility does not need to be checked in an instance: if the
1266 -- operator was not visible in the generic it has been diagnosed
1267 -- already, else there is an implicit copy of it in the instance.
1269 elsif In_Instance then
1272 elsif (Op_Name = Name_Op_Multiply
1273 or else Op_Name = Name_Op_Divide)
1274 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1275 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1277 if Pack /= Standard_Standard then
1281 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1284 elsif Ada_Version >= Ada_05
1285 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1286 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1291 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1293 if Op_Name = Name_Op_Concat then
1294 Opnd_Type := Base_Type (Typ);
1296 elsif (Scope (Opnd_Type) = Standard_Standard
1298 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1300 and then not Comes_From_Source (Opnd_Type))
1302 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1305 if Scope (Opnd_Type) = Standard_Standard then
1307 -- Verify that the scope contains a type that corresponds to
1308 -- the given literal. Optimize the case where Pack is Standard.
1310 if Pack /= Standard_Standard then
1312 if Opnd_Type = Universal_Integer then
1313 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1315 elsif Opnd_Type = Universal_Real then
1316 Orig_Type := Type_In_P (Is_Real_Type'Access);
1318 elsif Opnd_Type = Any_String then
1319 Orig_Type := Type_In_P (Is_String_Type'Access);
1321 elsif Opnd_Type = Any_Access then
1322 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1324 elsif Opnd_Type = Any_Composite then
1325 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1327 if Present (Orig_Type) then
1328 if Has_Private_Component (Orig_Type) then
1331 Set_Etype (Act1, Orig_Type);
1334 Set_Etype (Act2, Orig_Type);
1343 Error := No (Orig_Type);
1346 elsif Ekind (Opnd_Type) = E_Allocator_Type
1347 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1351 -- If the type is defined elsewhere, and the operator is not
1352 -- defined in the given scope (by a renaming declaration, e.g.)
1353 -- then this is an error as well. If an extension of System is
1354 -- present, and the type may be defined there, Pack must be
1357 elsif Scope (Opnd_Type) /= Pack
1358 and then Scope (Op_Id) /= Pack
1359 and then (No (System_Aux_Id)
1360 or else Scope (Opnd_Type) /= System_Aux_Id
1361 or else Pack /= Scope (System_Aux_Id))
1363 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1366 Error := not Operand_Type_In_Scope (Pack);
1369 elsif Pack = Standard_Standard
1370 and then not Operand_Type_In_Scope (Standard_Standard)
1377 Error_Msg_Node_2 := Pack;
1379 ("& not declared in&", N, Selector_Name (Name (N)));
1380 Set_Etype (N, Any_Type);
1385 Set_Chars (Op_Node, Op_Name);
1387 if not Is_Private_Type (Etype (N)) then
1388 Set_Etype (Op_Node, Base_Type (Etype (N)));
1390 Set_Etype (Op_Node, Etype (N));
1393 -- If this is a call to a function that renames a predefined equality,
1394 -- the renaming declaration provides a type that must be used to
1395 -- resolve the operands. This must be done now because resolution of
1396 -- the equality node will not resolve any remaining ambiguity, and it
1397 -- assumes that the first operand is not overloaded.
1399 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1400 and then Ekind (Func) = E_Function
1401 and then Is_Overloaded (Act1)
1403 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1404 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1407 Set_Entity (Op_Node, Op_Id);
1408 Generate_Reference (Op_Id, N, ' ');
1410 -- Do rewrite setting Comes_From_Source on the result if the original
1411 -- call came from source. Although it is not strictly the case that the
1412 -- operator as such comes from the source, logically it corresponds
1413 -- exactly to the function call in the source, so it should be marked
1414 -- this way (e.g. to make sure that validity checks work fine).
1417 CS : constant Boolean := Comes_From_Source (N);
1419 Rewrite (N, Op_Node);
1420 Set_Comes_From_Source (N, CS);
1423 -- If this is an arithmetic operator and the result type is private,
1424 -- the operands and the result must be wrapped in conversion to
1425 -- expose the underlying numeric type and expand the proper checks,
1426 -- e.g. on division.
1428 if Is_Private_Type (Typ) then
1430 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1431 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1432 Resolve_Intrinsic_Operator (N, Typ);
1434 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1435 Resolve_Intrinsic_Unary_Operator (N, Typ);
1444 -- For predefined operators on literals, the operation freezes
1447 if Present (Orig_Type) then
1448 Set_Etype (Act1, Orig_Type);
1449 Freeze_Expression (Act1);
1451 end Make_Call_Into_Operator;
1457 function Operator_Kind
1459 Is_Binary : Boolean) return Node_Kind
1465 if Op_Name = Name_Op_And then
1467 elsif Op_Name = Name_Op_Or then
1469 elsif Op_Name = Name_Op_Xor then
1471 elsif Op_Name = Name_Op_Eq then
1473 elsif Op_Name = Name_Op_Ne then
1475 elsif Op_Name = Name_Op_Lt then
1477 elsif Op_Name = Name_Op_Le then
1479 elsif Op_Name = Name_Op_Gt then
1481 elsif Op_Name = Name_Op_Ge then
1483 elsif Op_Name = Name_Op_Add then
1485 elsif Op_Name = Name_Op_Subtract then
1486 Kind := N_Op_Subtract;
1487 elsif Op_Name = Name_Op_Concat then
1488 Kind := N_Op_Concat;
1489 elsif Op_Name = Name_Op_Multiply then
1490 Kind := N_Op_Multiply;
1491 elsif Op_Name = Name_Op_Divide then
1492 Kind := N_Op_Divide;
1493 elsif Op_Name = Name_Op_Mod then
1495 elsif Op_Name = Name_Op_Rem then
1497 elsif Op_Name = Name_Op_Expon then
1500 raise Program_Error;
1506 if Op_Name = Name_Op_Add then
1508 elsif Op_Name = Name_Op_Subtract then
1510 elsif Op_Name = Name_Op_Abs then
1512 elsif Op_Name = Name_Op_Not then
1515 raise Program_Error;
1522 ----------------------------
1523 -- Preanalyze_And_Resolve --
1524 ----------------------------
1526 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1527 Save_Full_Analysis : constant Boolean := Full_Analysis;
1530 Full_Analysis := False;
1531 Expander_Mode_Save_And_Set (False);
1533 -- We suppress all checks for this analysis, since the checks will
1534 -- be applied properly, and in the right location, when the default
1535 -- expression is reanalyzed and reexpanded later on.
1537 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1539 Expander_Mode_Restore;
1540 Full_Analysis := Save_Full_Analysis;
1541 end Preanalyze_And_Resolve;
1543 -- Version without context type
1545 procedure Preanalyze_And_Resolve (N : Node_Id) is
1546 Save_Full_Analysis : constant Boolean := Full_Analysis;
1549 Full_Analysis := False;
1550 Expander_Mode_Save_And_Set (False);
1553 Resolve (N, Etype (N), Suppress => All_Checks);
1555 Expander_Mode_Restore;
1556 Full_Analysis := Save_Full_Analysis;
1557 end Preanalyze_And_Resolve;
1559 ----------------------------------
1560 -- Replace_Actual_Discriminants --
1561 ----------------------------------
1563 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1564 Loc : constant Source_Ptr := Sloc (N);
1565 Tsk : Node_Id := Empty;
1567 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1573 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1577 if Nkind (Nod) = N_Identifier then
1578 Ent := Entity (Nod);
1581 and then Ekind (Ent) = E_Discriminant
1584 Make_Selected_Component (Loc,
1585 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1586 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1588 Set_Etype (Nod, Etype (Ent));
1596 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1598 -- Start of processing for Replace_Actual_Discriminants
1601 if not Expander_Active then
1605 if Nkind (Name (N)) = N_Selected_Component then
1606 Tsk := Prefix (Name (N));
1608 elsif Nkind (Name (N)) = N_Indexed_Component then
1609 Tsk := Prefix (Prefix (Name (N)));
1615 Replace_Discrs (Default);
1617 end Replace_Actual_Discriminants;
1623 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1624 Ambiguous : Boolean := False;
1625 Ctx_Type : Entity_Id := Typ;
1626 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1627 Err_Type : Entity_Id := Empty;
1628 Found : Boolean := False;
1631 I1 : Interp_Index := 0; -- prevent junk warning
1634 Seen : Entity_Id := Empty; -- prevent junk warning
1636 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1637 -- Determine whether a node comes from a predefined library unit or
1640 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1641 -- Try and fix up a literal so that it matches its expected type. New
1642 -- literals are manufactured if necessary to avoid cascaded errors.
1644 procedure Resolution_Failed;
1645 -- Called when attempt at resolving current expression fails
1647 ------------------------------------
1648 -- Comes_From_Predefined_Lib_Unit --
1649 -------------------------------------
1651 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1654 Sloc (Nod) = Standard_Location
1655 or else Is_Predefined_File_Name (Unit_File_Name (
1656 Get_Source_Unit (Sloc (Nod))));
1657 end Comes_From_Predefined_Lib_Unit;
1659 --------------------
1660 -- Patch_Up_Value --
1661 --------------------
1663 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1665 if Nkind (N) = N_Integer_Literal
1666 and then Is_Real_Type (Typ)
1669 Make_Real_Literal (Sloc (N),
1670 Realval => UR_From_Uint (Intval (N))));
1671 Set_Etype (N, Universal_Real);
1672 Set_Is_Static_Expression (N);
1674 elsif Nkind (N) = N_Real_Literal
1675 and then Is_Integer_Type (Typ)
1678 Make_Integer_Literal (Sloc (N),
1679 Intval => UR_To_Uint (Realval (N))));
1680 Set_Etype (N, Universal_Integer);
1681 Set_Is_Static_Expression (N);
1683 elsif Nkind (N) = N_String_Literal
1684 and then Is_Character_Type (Typ)
1686 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1688 Make_Character_Literal (Sloc (N),
1690 Char_Literal_Value =>
1691 UI_From_Int (Character'Pos ('A'))));
1692 Set_Etype (N, Any_Character);
1693 Set_Is_Static_Expression (N);
1695 elsif Nkind (N) /= N_String_Literal
1696 and then Is_String_Type (Typ)
1699 Make_String_Literal (Sloc (N),
1700 Strval => End_String));
1702 elsif Nkind (N) = N_Range then
1703 Patch_Up_Value (Low_Bound (N), Typ);
1704 Patch_Up_Value (High_Bound (N), Typ);
1708 -----------------------
1709 -- Resolution_Failed --
1710 -----------------------
1712 procedure Resolution_Failed is
1714 Patch_Up_Value (N, Typ);
1716 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1717 Set_Is_Overloaded (N, False);
1719 -- The caller will return without calling the expander, so we need
1720 -- to set the analyzed flag. Note that it is fine to set Analyzed
1721 -- to True even if we are in the middle of a shallow analysis,
1722 -- (see the spec of sem for more details) since this is an error
1723 -- situation anyway, and there is no point in repeating the
1724 -- analysis later (indeed it won't work to repeat it later, since
1725 -- we haven't got a clear resolution of which entity is being
1728 Set_Analyzed (N, True);
1730 end Resolution_Failed;
1732 -- Start of processing for Resolve
1739 -- Access attribute on remote subprogram cannot be used for
1740 -- a non-remote access-to-subprogram type.
1742 if Nkind (N) = N_Attribute_Reference
1743 and then (Attribute_Name (N) = Name_Access
1744 or else Attribute_Name (N) = Name_Unrestricted_Access
1745 or else Attribute_Name (N) = Name_Unchecked_Access)
1746 and then Comes_From_Source (N)
1747 and then Is_Entity_Name (Prefix (N))
1748 and then Is_Subprogram (Entity (Prefix (N)))
1749 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1750 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1753 ("prefix must statically denote a non-remote subprogram", N);
1756 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1758 -- If the context is a Remote_Access_To_Subprogram, access attributes
1759 -- must be resolved with the corresponding fat pointer. There is no need
1760 -- to check for the attribute name since the return type of an
1761 -- attribute is never a remote type.
1763 if Nkind (N) = N_Attribute_Reference
1764 and then Comes_From_Source (N)
1765 and then (Is_Remote_Call_Interface (Typ)
1766 or else Is_Remote_Types (Typ))
1769 Attr : constant Attribute_Id :=
1770 Get_Attribute_Id (Attribute_Name (N));
1771 Pref : constant Node_Id := Prefix (N);
1774 Is_Remote : Boolean := True;
1777 -- Check that Typ is a remote access-to-subprogram type
1779 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1780 -- Prefix (N) must statically denote a remote subprogram
1781 -- declared in a package specification.
1783 if Attr = Attribute_Access then
1784 Decl := Unit_Declaration_Node (Entity (Pref));
1786 if Nkind (Decl) = N_Subprogram_Body then
1787 Spec := Corresponding_Spec (Decl);
1789 if not No (Spec) then
1790 Decl := Unit_Declaration_Node (Spec);
1794 Spec := Parent (Decl);
1796 if not Is_Entity_Name (Prefix (N))
1797 or else Nkind (Spec) /= N_Package_Specification
1799 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1803 ("prefix must statically denote a remote subprogram ",
1808 -- If we are generating code for a distributed program.
1809 -- perform semantic checks against the corresponding
1812 if (Attr = Attribute_Access
1813 or else Attr = Attribute_Unchecked_Access
1814 or else Attr = Attribute_Unrestricted_Access)
1815 and then Expander_Active
1816 and then Get_PCS_Name /= Name_No_DSA
1818 Check_Subtype_Conformant
1819 (New_Id => Entity (Prefix (N)),
1820 Old_Id => Designated_Type
1821 (Corresponding_Remote_Type (Typ)),
1825 Process_Remote_AST_Attribute (N, Typ);
1832 Debug_A_Entry ("resolving ", N);
1834 if Comes_From_Source (N) then
1835 if Is_Fixed_Point_Type (Typ) then
1836 Check_Restriction (No_Fixed_Point, N);
1838 elsif Is_Floating_Point_Type (Typ)
1839 and then Typ /= Universal_Real
1840 and then Typ /= Any_Real
1842 Check_Restriction (No_Floating_Point, N);
1846 -- Return if already analyzed
1848 if Analyzed (N) then
1849 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1852 -- Return if type = Any_Type (previous error encountered)
1854 elsif Etype (N) = Any_Type then
1855 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1859 Check_Parameterless_Call (N);
1861 -- If not overloaded, then we know the type, and all that needs doing
1862 -- is to check that this type is compatible with the context.
1864 if not Is_Overloaded (N) then
1865 Found := Covers (Typ, Etype (N));
1866 Expr_Type := Etype (N);
1868 -- In the overloaded case, we must select the interpretation that
1869 -- is compatible with the context (i.e. the type passed to Resolve)
1872 -- Loop through possible interpretations
1874 Get_First_Interp (N, I, It);
1875 Interp_Loop : while Present (It.Typ) loop
1877 -- We are only interested in interpretations that are compatible
1878 -- with the expected type, any other interpretations are ignored.
1880 if not Covers (Typ, It.Typ) then
1881 if Debug_Flag_V then
1882 Write_Str (" interpretation incompatible with context");
1887 -- Skip the current interpretation if it is disabled by an
1888 -- abstract operator. This action is performed only when the
1889 -- type against which we are resolving is the same as the
1890 -- type of the interpretation.
1892 if Ada_Version >= Ada_05
1893 and then It.Typ = Typ
1894 and then Typ /= Universal_Integer
1895 and then Typ /= Universal_Real
1896 and then Present (It.Abstract_Op)
1901 -- First matching interpretation
1907 Expr_Type := It.Typ;
1909 -- Matching interpretation that is not the first, maybe an
1910 -- error, but there are some cases where preference rules are
1911 -- used to choose between the two possibilities. These and
1912 -- some more obscure cases are handled in Disambiguate.
1915 -- If the current statement is part of a predefined library
1916 -- unit, then all interpretations which come from user level
1917 -- packages should not be considered.
1920 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1925 Error_Msg_Sloc := Sloc (Seen);
1926 It1 := Disambiguate (N, I1, I, Typ);
1928 -- Disambiguation has succeeded. Skip the remaining
1931 if It1 /= No_Interp then
1933 Expr_Type := It1.Typ;
1935 while Present (It.Typ) loop
1936 Get_Next_Interp (I, It);
1940 -- Before we issue an ambiguity complaint, check for
1941 -- the case of a subprogram call where at least one
1942 -- of the arguments is Any_Type, and if so, suppress
1943 -- the message, since it is a cascaded error.
1945 if Nkind_In (N, N_Function_Call,
1946 N_Procedure_Call_Statement)
1953 A := First_Actual (N);
1954 while Present (A) loop
1957 if Nkind (E) = N_Parameter_Association then
1958 E := Explicit_Actual_Parameter (E);
1961 if Etype (E) = Any_Type then
1962 if Debug_Flag_V then
1963 Write_Str ("Any_Type in call");
1974 elsif Nkind (N) in N_Binary_Op
1975 and then (Etype (Left_Opnd (N)) = Any_Type
1976 or else Etype (Right_Opnd (N)) = Any_Type)
1980 elsif Nkind (N) in N_Unary_Op
1981 and then Etype (Right_Opnd (N)) = Any_Type
1986 -- Not that special case, so issue message using the
1987 -- flag Ambiguous to control printing of the header
1988 -- message only at the start of an ambiguous set.
1990 if not Ambiguous then
1991 if Nkind (N) = N_Function_Call
1992 and then Nkind (Name (N)) = N_Explicit_Dereference
1995 ("ambiguous expression "
1996 & "(cannot resolve indirect call)!", N);
1999 ("ambiguous expression (cannot resolve&)!",
2005 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2007 ("\\possible interpretation (inherited)#!", N);
2009 Error_Msg_N ("\\possible interpretation#!", N);
2013 Error_Msg_Sloc := Sloc (It.Nam);
2015 -- By default, the error message refers to the candidate
2016 -- interpretation. But if it is a predefined operator, it
2017 -- is implicitly declared at the declaration of the type
2018 -- of the operand. Recover the sloc of that declaration
2019 -- for the error message.
2021 if Nkind (N) in N_Op
2022 and then Scope (It.Nam) = Standard_Standard
2023 and then not Is_Overloaded (Right_Opnd (N))
2024 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2027 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2029 if Comes_From_Source (Err_Type)
2030 and then Present (Parent (Err_Type))
2032 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2035 elsif Nkind (N) in N_Binary_Op
2036 and then Scope (It.Nam) = Standard_Standard
2037 and then not Is_Overloaded (Left_Opnd (N))
2038 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2041 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2043 if Comes_From_Source (Err_Type)
2044 and then Present (Parent (Err_Type))
2046 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2049 -- If this is an indirect call, use the subprogram_type
2050 -- in the message, to have a meaningful location.
2051 -- Indicate as well if this is an inherited operation,
2052 -- created by a type declaration.
2054 elsif Nkind (N) = N_Function_Call
2055 and then Nkind (Name (N)) = N_Explicit_Dereference
2056 and then Is_Type (It.Nam)
2060 Sloc (Associated_Node_For_Itype (Err_Type));
2065 if Nkind (N) in N_Op
2066 and then Scope (It.Nam) = Standard_Standard
2067 and then Present (Err_Type)
2069 -- Special-case the message for universal_fixed
2070 -- operators, which are not declared with the type
2071 -- of the operand, but appear forever in Standard.
2073 if It.Typ = Universal_Fixed
2074 and then Scope (It.Nam) = Standard_Standard
2077 ("\\possible interpretation as " &
2078 "universal_fixed operation " &
2079 "(RM 4.5.5 (19))", N);
2082 ("\\possible interpretation (predefined)#!", N);
2086 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2089 ("\\possible interpretation (inherited)#!", N);
2091 Error_Msg_N ("\\possible interpretation#!", N);
2097 -- We have a matching interpretation, Expr_Type is the type
2098 -- from this interpretation, and Seen is the entity.
2100 -- For an operator, just set the entity name. The type will be
2101 -- set by the specific operator resolution routine.
2103 if Nkind (N) in N_Op then
2104 Set_Entity (N, Seen);
2105 Generate_Reference (Seen, N);
2107 elsif Nkind (N) = N_Character_Literal then
2108 Set_Etype (N, Expr_Type);
2110 -- For an explicit dereference, attribute reference, range,
2111 -- short-circuit form (which is not an operator node), or call
2112 -- with a name that is an explicit dereference, there is
2113 -- nothing to be done at this point.
2115 elsif Nkind_In (N, N_Explicit_Dereference,
2116 N_Attribute_Reference,
2118 N_Indexed_Component,
2121 N_Selected_Component,
2123 or else Nkind (Name (N)) = N_Explicit_Dereference
2127 -- For procedure or function calls, set the type of the name,
2128 -- and also the entity pointer for the prefix
2130 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2131 and then (Is_Entity_Name (Name (N))
2132 or else Nkind (Name (N)) = N_Operator_Symbol)
2134 Set_Etype (Name (N), Expr_Type);
2135 Set_Entity (Name (N), Seen);
2136 Generate_Reference (Seen, Name (N));
2138 elsif Nkind (N) = N_Function_Call
2139 and then Nkind (Name (N)) = N_Selected_Component
2141 Set_Etype (Name (N), Expr_Type);
2142 Set_Entity (Selector_Name (Name (N)), Seen);
2143 Generate_Reference (Seen, Selector_Name (Name (N)));
2145 -- For all other cases, just set the type of the Name
2148 Set_Etype (Name (N), Expr_Type);
2155 -- Move to next interpretation
2157 exit Interp_Loop when No (It.Typ);
2159 Get_Next_Interp (I, It);
2160 end loop Interp_Loop;
2163 -- At this stage Found indicates whether or not an acceptable
2164 -- interpretation exists. If not, then we have an error, except
2165 -- that if the context is Any_Type as a result of some other error,
2166 -- then we suppress the error report.
2169 if Typ /= Any_Type then
2171 -- If type we are looking for is Void, then this is the procedure
2172 -- call case, and the error is simply that what we gave is not a
2173 -- procedure name (we think of procedure calls as expressions with
2174 -- types internally, but the user doesn't think of them this way!)
2176 if Typ = Standard_Void_Type then
2178 -- Special case message if function used as a procedure
2180 if Nkind (N) = N_Procedure_Call_Statement
2181 and then Is_Entity_Name (Name (N))
2182 and then Ekind (Entity (Name (N))) = E_Function
2185 ("cannot use function & in a procedure call",
2186 Name (N), Entity (Name (N)));
2188 -- Otherwise give general message (not clear what cases this
2189 -- covers, but no harm in providing for them!)
2192 Error_Msg_N ("expect procedure name in procedure call", N);
2197 -- Otherwise we do have a subexpression with the wrong type
2199 -- Check for the case of an allocator which uses an access type
2200 -- instead of the designated type. This is a common error and we
2201 -- specialize the message, posting an error on the operand of the
2202 -- allocator, complaining that we expected the designated type of
2205 elsif Nkind (N) = N_Allocator
2206 and then Ekind (Typ) in Access_Kind
2207 and then Ekind (Etype (N)) in Access_Kind
2208 and then Designated_Type (Etype (N)) = Typ
2210 Wrong_Type (Expression (N), Designated_Type (Typ));
2213 -- Check for view mismatch on Null in instances, for which the
2214 -- view-swapping mechanism has no identifier.
2216 elsif (In_Instance or else In_Inlined_Body)
2217 and then (Nkind (N) = N_Null)
2218 and then Is_Private_Type (Typ)
2219 and then Is_Access_Type (Full_View (Typ))
2221 Resolve (N, Full_View (Typ));
2225 -- Check for an aggregate. Sometimes we can get bogus aggregates
2226 -- from misuse of parentheses, and we are about to complain about
2227 -- the aggregate without even looking inside it.
2229 -- Instead, if we have an aggregate of type Any_Composite, then
2230 -- analyze and resolve the component fields, and then only issue
2231 -- another message if we get no errors doing this (otherwise
2232 -- assume that the errors in the aggregate caused the problem).
2234 elsif Nkind (N) = N_Aggregate
2235 and then Etype (N) = Any_Composite
2237 -- Disable expansion in any case. If there is a type mismatch
2238 -- it may be fatal to try to expand the aggregate. The flag
2239 -- would otherwise be set to false when the error is posted.
2241 Expander_Active := False;
2244 procedure Check_Aggr (Aggr : Node_Id);
2245 -- Check one aggregate, and set Found to True if we have a
2246 -- definite error in any of its elements
2248 procedure Check_Elmt (Aelmt : Node_Id);
2249 -- Check one element of aggregate and set Found to True if
2250 -- we definitely have an error in the element.
2256 procedure Check_Aggr (Aggr : Node_Id) is
2260 if Present (Expressions (Aggr)) then
2261 Elmt := First (Expressions (Aggr));
2262 while Present (Elmt) loop
2268 if Present (Component_Associations (Aggr)) then
2269 Elmt := First (Component_Associations (Aggr));
2270 while Present (Elmt) loop
2272 -- If this is a default-initialized component, then
2273 -- there is nothing to check. The box will be
2274 -- replaced by the appropriate call during late
2277 if not Box_Present (Elmt) then
2278 Check_Elmt (Expression (Elmt));
2290 procedure Check_Elmt (Aelmt : Node_Id) is
2292 -- If we have a nested aggregate, go inside it (to
2293 -- attempt a naked analyze-resolve of the aggregate
2294 -- can cause undesirable cascaded errors). Do not
2295 -- resolve expression if it needs a type from context,
2296 -- as for integer * fixed expression.
2298 if Nkind (Aelmt) = N_Aggregate then
2304 if not Is_Overloaded (Aelmt)
2305 and then Etype (Aelmt) /= Any_Fixed
2310 if Etype (Aelmt) = Any_Type then
2321 -- If an error message was issued already, Found got reset
2322 -- to True, so if it is still False, issue the standard
2323 -- Wrong_Type message.
2326 if Is_Overloaded (N)
2327 and then Nkind (N) = N_Function_Call
2330 Subp_Name : Node_Id;
2332 if Is_Entity_Name (Name (N)) then
2333 Subp_Name := Name (N);
2335 elsif Nkind (Name (N)) = N_Selected_Component then
2337 -- Protected operation: retrieve operation name
2339 Subp_Name := Selector_Name (Name (N));
2341 raise Program_Error;
2344 Error_Msg_Node_2 := Typ;
2345 Error_Msg_NE ("no visible interpretation of&" &
2346 " matches expected type&", N, Subp_Name);
2349 if All_Errors_Mode then
2351 Index : Interp_Index;
2355 Error_Msg_N ("\\possible interpretations:", N);
2357 Get_First_Interp (Name (N), Index, It);
2358 while Present (It.Nam) loop
2359 Error_Msg_Sloc := Sloc (It.Nam);
2360 Error_Msg_Node_2 := It.Nam;
2362 ("\\ type& for & declared#", N, It.Typ);
2363 Get_Next_Interp (Index, It);
2368 Error_Msg_N ("\use -gnatf for details", N);
2371 Wrong_Type (N, Typ);
2379 -- Test if we have more than one interpretation for the context
2381 elsif Ambiguous then
2385 -- Here we have an acceptable interpretation for the context
2388 -- Propagate type information and normalize tree for various
2389 -- predefined operations. If the context only imposes a class of
2390 -- types, rather than a specific type, propagate the actual type
2393 if Typ = Any_Integer
2394 or else Typ = Any_Boolean
2395 or else Typ = Any_Modular
2396 or else Typ = Any_Real
2397 or else Typ = Any_Discrete
2399 Ctx_Type := Expr_Type;
2401 -- Any_Fixed is legal in a real context only if a specific
2402 -- fixed point type is imposed. If Norman Cohen can be
2403 -- confused by this, it deserves a separate message.
2406 and then Expr_Type = Any_Fixed
2408 Error_Msg_N ("illegal context for mixed mode operation", N);
2409 Set_Etype (N, Universal_Real);
2410 Ctx_Type := Universal_Real;
2414 -- A user-defined operator is transformed into a function call at
2415 -- this point, so that further processing knows that operators are
2416 -- really operators (i.e. are predefined operators). User-defined
2417 -- operators that are intrinsic are just renamings of the predefined
2418 -- ones, and need not be turned into calls either, but if they rename
2419 -- a different operator, we must transform the node accordingly.
2420 -- Instantiations of Unchecked_Conversion are intrinsic but are
2421 -- treated as functions, even if given an operator designator.
2423 if Nkind (N) in N_Op
2424 and then Present (Entity (N))
2425 and then Ekind (Entity (N)) /= E_Operator
2428 if not Is_Predefined_Op (Entity (N)) then
2429 Rewrite_Operator_As_Call (N, Entity (N));
2431 elsif Present (Alias (Entity (N)))
2433 Nkind (Parent (Parent (Entity (N)))) =
2434 N_Subprogram_Renaming_Declaration
2436 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2438 -- If the node is rewritten, it will be fully resolved in
2439 -- Rewrite_Renamed_Operator.
2441 if Analyzed (N) then
2447 case N_Subexpr'(Nkind (N)) is
2449 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2451 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2453 when N_And_Then | N_Or_Else
2454 => Resolve_Short_Circuit (N, Ctx_Type);
2456 when N_Attribute_Reference
2457 => Resolve_Attribute (N, Ctx_Type);
2459 when N_Character_Literal
2460 => Resolve_Character_Literal (N, Ctx_Type);
2462 when N_Conditional_Expression
2463 => Resolve_Conditional_Expression (N, Ctx_Type);
2465 when N_Expanded_Name
2466 => Resolve_Entity_Name (N, Ctx_Type);
2468 when N_Extension_Aggregate
2469 => Resolve_Extension_Aggregate (N, Ctx_Type);
2471 when N_Explicit_Dereference
2472 => Resolve_Explicit_Dereference (N, Ctx_Type);
2474 when N_Function_Call
2475 => Resolve_Call (N, Ctx_Type);
2478 => Resolve_Entity_Name (N, Ctx_Type);
2480 when N_Indexed_Component
2481 => Resolve_Indexed_Component (N, Ctx_Type);
2483 when N_Integer_Literal
2484 => Resolve_Integer_Literal (N, Ctx_Type);
2486 when N_Membership_Test
2487 => Resolve_Membership_Op (N, Ctx_Type);
2489 when N_Null => Resolve_Null (N, Ctx_Type);
2491 when N_Op_And | N_Op_Or | N_Op_Xor
2492 => Resolve_Logical_Op (N, Ctx_Type);
2494 when N_Op_Eq | N_Op_Ne
2495 => Resolve_Equality_Op (N, Ctx_Type);
2497 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2498 => Resolve_Comparison_Op (N, Ctx_Type);
2500 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2502 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2503 N_Op_Divide | N_Op_Mod | N_Op_Rem
2505 => Resolve_Arithmetic_Op (N, Ctx_Type);
2507 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2509 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2511 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2512 => Resolve_Unary_Op (N, Ctx_Type);
2514 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2516 when N_Procedure_Call_Statement
2517 => Resolve_Call (N, Ctx_Type);
2519 when N_Operator_Symbol
2520 => Resolve_Operator_Symbol (N, Ctx_Type);
2522 when N_Qualified_Expression
2523 => Resolve_Qualified_Expression (N, Ctx_Type);
2525 when N_Raise_xxx_Error
2526 => Set_Etype (N, Ctx_Type);
2528 when N_Range => Resolve_Range (N, Ctx_Type);
2531 => Resolve_Real_Literal (N, Ctx_Type);
2533 when N_Reference => Resolve_Reference (N, Ctx_Type);
2535 when N_Selected_Component
2536 => Resolve_Selected_Component (N, Ctx_Type);
2538 when N_Slice => Resolve_Slice (N, Ctx_Type);
2540 when N_String_Literal
2541 => Resolve_String_Literal (N, Ctx_Type);
2543 when N_Subprogram_Info
2544 => Resolve_Subprogram_Info (N, Ctx_Type);
2546 when N_Type_Conversion
2547 => Resolve_Type_Conversion (N, Ctx_Type);
2549 when N_Unchecked_Expression =>
2550 Resolve_Unchecked_Expression (N, Ctx_Type);
2552 when N_Unchecked_Type_Conversion =>
2553 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2557 -- If the subexpression was replaced by a non-subexpression, then
2558 -- all we do is to expand it. The only legitimate case we know of
2559 -- is converting procedure call statement to entry call statements,
2560 -- but there may be others, so we are making this test general.
2562 if Nkind (N) not in N_Subexpr then
2563 Debug_A_Exit ("resolving ", N, " (done)");
2568 -- The expression is definitely NOT overloaded at this point, so
2569 -- we reset the Is_Overloaded flag to avoid any confusion when
2570 -- reanalyzing the node.
2572 Set_Is_Overloaded (N, False);
2574 -- Freeze expression type, entity if it is a name, and designated
2575 -- type if it is an allocator (RM 13.14(10,11,13)).
2577 -- Now that the resolution of the type of the node is complete,
2578 -- and we did not detect an error, we can expand this node. We
2579 -- skip the expand call if we are in a default expression, see
2580 -- section "Handling of Default Expressions" in Sem spec.
2582 Debug_A_Exit ("resolving ", N, " (done)");
2584 -- We unconditionally freeze the expression, even if we are in
2585 -- default expression mode (the Freeze_Expression routine tests
2586 -- this flag and only freezes static types if it is set).
2588 Freeze_Expression (N);
2590 -- Now we can do the expansion
2600 -- Version with check(s) suppressed
2602 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2604 if Suppress = All_Checks then
2606 Svg : constant Suppress_Array := Scope_Suppress;
2608 Scope_Suppress := (others => True);
2610 Scope_Suppress := Svg;
2615 Svg : constant Boolean := Scope_Suppress (Suppress);
2617 Scope_Suppress (Suppress) := True;
2619 Scope_Suppress (Suppress) := Svg;
2628 -- Version with implicit type
2630 procedure Resolve (N : Node_Id) is
2632 Resolve (N, Etype (N));
2635 ---------------------
2636 -- Resolve_Actuals --
2637 ---------------------
2639 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2640 Loc : constant Source_Ptr := Sloc (N);
2645 Prev : Node_Id := Empty;
2648 procedure Check_Argument_Order;
2649 -- Performs a check for the case where the actuals are all simple
2650 -- identifiers that correspond to the formal names, but in the wrong
2651 -- order, which is considered suspicious and cause for a warning.
2653 procedure Check_Prefixed_Call;
2654 -- If the original node is an overloaded call in prefix notation,
2655 -- insert an 'Access or a dereference as needed over the first actual.
2656 -- Try_Object_Operation has already verified that there is a valid
2657 -- interpretation, but the form of the actual can only be determined
2658 -- once the primitive operation is identified.
2660 procedure Insert_Default;
2661 -- If the actual is missing in a call, insert in the actuals list
2662 -- an instance of the default expression. The insertion is always
2663 -- a named association.
2665 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2666 -- Check whether T1 and T2, or their full views, are derived from a
2667 -- common type. Used to enforce the restrictions on array conversions
2670 --------------------------
2671 -- Check_Argument_Order --
2672 --------------------------
2674 procedure Check_Argument_Order is
2676 -- Nothing to do if no parameters, or original node is neither a
2677 -- function call nor a procedure call statement (happens in the
2678 -- operator-transformed-to-function call case), or the call does
2679 -- not come from source, or this warning is off.
2681 if not Warn_On_Parameter_Order
2683 No (Parameter_Associations (N))
2685 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2688 not Comes_From_Source (N)
2694 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2697 -- Nothing to do if only one parameter
2703 -- Here if at least two arguments
2706 Actuals : array (1 .. Nargs) of Node_Id;
2710 Wrong_Order : Boolean := False;
2711 -- Set True if an out of order case is found
2714 -- Collect identifier names of actuals, fail if any actual is
2715 -- not a simple identifier, and record max length of name.
2717 Actual := First (Parameter_Associations (N));
2718 for J in Actuals'Range loop
2719 if Nkind (Actual) /= N_Identifier then
2722 Actuals (J) := Actual;
2727 -- If we got this far, all actuals are identifiers and the list
2728 -- of their names is stored in the Actuals array.
2730 Formal := First_Formal (Nam);
2731 for J in Actuals'Range loop
2733 -- If we ran out of formals, that's odd, probably an error
2734 -- which will be detected elsewhere, but abandon the search.
2740 -- If name matches and is in order OK
2742 if Chars (Formal) = Chars (Actuals (J)) then
2746 -- If no match, see if it is elsewhere in list and if so
2747 -- flag potential wrong order if type is compatible.
2749 for K in Actuals'Range loop
2750 if Chars (Formal) = Chars (Actuals (K))
2752 Has_Compatible_Type (Actuals (K), Etype (Formal))
2754 Wrong_Order := True;
2764 <<Continue>> Next_Formal (Formal);
2767 -- If Formals left over, also probably an error, skip warning
2769 if Present (Formal) then
2773 -- Here we give the warning if something was out of order
2777 ("actuals for this call may be in wrong order?", N);
2781 end Check_Argument_Order;
2783 -------------------------
2784 -- Check_Prefixed_Call --
2785 -------------------------
2787 procedure Check_Prefixed_Call is
2788 Act : constant Node_Id := First_Actual (N);
2789 A_Type : constant Entity_Id := Etype (Act);
2790 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2791 Orig : constant Node_Id := Original_Node (N);
2795 -- Check whether the call is a prefixed call, with or without
2796 -- additional actuals.
2798 if Nkind (Orig) = N_Selected_Component
2800 (Nkind (Orig) = N_Indexed_Component
2801 and then Nkind (Prefix (Orig)) = N_Selected_Component
2802 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2803 and then Is_Entity_Name (Act)
2804 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2806 if Is_Access_Type (A_Type)
2807 and then not Is_Access_Type (F_Type)
2809 -- Introduce dereference on object in prefix
2812 Make_Explicit_Dereference (Sloc (Act),
2813 Prefix => Relocate_Node (Act));
2814 Rewrite (Act, New_A);
2817 elsif Is_Access_Type (F_Type)
2818 and then not Is_Access_Type (A_Type)
2820 -- Introduce an implicit 'Access in prefix
2822 if not Is_Aliased_View (Act) then
2824 ("object in prefixed call to& must be aliased"
2825 & " (RM-2005 4.3.1 (13))",
2830 Make_Attribute_Reference (Loc,
2831 Attribute_Name => Name_Access,
2832 Prefix => Relocate_Node (Act)));
2837 end Check_Prefixed_Call;
2839 --------------------
2840 -- Insert_Default --
2841 --------------------
2843 procedure Insert_Default is
2848 -- Missing argument in call, nothing to insert
2850 if No (Default_Value (F)) then
2854 -- Note that we do a full New_Copy_Tree, so that any associated
2855 -- Itypes are properly copied. This may not be needed any more,
2856 -- but it does no harm as a safety measure! Defaults of a generic
2857 -- formal may be out of bounds of the corresponding actual (see
2858 -- cc1311b) and an additional check may be required.
2863 New_Scope => Current_Scope,
2866 if Is_Concurrent_Type (Scope (Nam))
2867 and then Has_Discriminants (Scope (Nam))
2869 Replace_Actual_Discriminants (N, Actval);
2872 if Is_Overloadable (Nam)
2873 and then Present (Alias (Nam))
2875 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2876 and then not Is_Tagged_Type (Etype (F))
2878 -- If default is a real literal, do not introduce a
2879 -- conversion whose effect may depend on the run-time
2880 -- size of universal real.
2882 if Nkind (Actval) = N_Real_Literal then
2883 Set_Etype (Actval, Base_Type (Etype (F)));
2885 Actval := Unchecked_Convert_To (Etype (F), Actval);
2889 if Is_Scalar_Type (Etype (F)) then
2890 Enable_Range_Check (Actval);
2893 Set_Parent (Actval, N);
2895 -- Resolve aggregates with their base type, to avoid scope
2896 -- anomalies: the subtype was first built in the subprogram
2897 -- declaration, and the current call may be nested.
2899 if Nkind (Actval) = N_Aggregate
2900 and then Has_Discriminants (Etype (Actval))
2902 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2904 Analyze_And_Resolve (Actval, Etype (Actval));
2908 Set_Parent (Actval, N);
2910 -- See note above concerning aggregates
2912 if Nkind (Actval) = N_Aggregate
2913 and then Has_Discriminants (Etype (Actval))
2915 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2917 -- Resolve entities with their own type, which may differ
2918 -- from the type of a reference in a generic context (the
2919 -- view swapping mechanism did not anticipate the re-analysis
2920 -- of default values in calls).
2922 elsif Is_Entity_Name (Actval) then
2923 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2926 Analyze_And_Resolve (Actval, Etype (Actval));
2930 -- If default is a tag indeterminate function call, propagate
2931 -- tag to obtain proper dispatching.
2933 if Is_Controlling_Formal (F)
2934 and then Nkind (Default_Value (F)) = N_Function_Call
2936 Set_Is_Controlling_Actual (Actval);
2941 -- If the default expression raises constraint error, then just
2942 -- silently replace it with an N_Raise_Constraint_Error node,
2943 -- since we already gave the warning on the subprogram spec.
2945 if Raises_Constraint_Error (Actval) then
2947 Make_Raise_Constraint_Error (Loc,
2948 Reason => CE_Range_Check_Failed));
2949 Set_Raises_Constraint_Error (Actval);
2950 Set_Etype (Actval, Etype (F));
2954 Make_Parameter_Association (Loc,
2955 Explicit_Actual_Parameter => Actval,
2956 Selector_Name => Make_Identifier (Loc, Chars (F)));
2958 -- Case of insertion is first named actual
2960 if No (Prev) or else
2961 Nkind (Parent (Prev)) /= N_Parameter_Association
2963 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2964 Set_First_Named_Actual (N, Actval);
2967 if No (Parameter_Associations (N)) then
2968 Set_Parameter_Associations (N, New_List (Assoc));
2970 Append (Assoc, Parameter_Associations (N));
2974 Insert_After (Prev, Assoc);
2977 -- Case of insertion is not first named actual
2980 Set_Next_Named_Actual
2981 (Assoc, Next_Named_Actual (Parent (Prev)));
2982 Set_Next_Named_Actual (Parent (Prev), Actval);
2983 Append (Assoc, Parameter_Associations (N));
2986 Mark_Rewrite_Insertion (Assoc);
2987 Mark_Rewrite_Insertion (Actval);
2996 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2997 FT1 : Entity_Id := T1;
2998 FT2 : Entity_Id := T2;
3001 if Is_Private_Type (T1)
3002 and then Present (Full_View (T1))
3004 FT1 := Full_View (T1);
3007 if Is_Private_Type (T2)
3008 and then Present (Full_View (T2))
3010 FT2 := Full_View (T2);
3013 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3016 -- Start of processing for Resolve_Actuals
3019 Check_Argument_Order;
3021 if Present (First_Actual (N)) then
3022 Check_Prefixed_Call;
3025 A := First_Actual (N);
3026 F := First_Formal (Nam);
3027 while Present (F) loop
3028 if No (A) and then Needs_No_Actuals (Nam) then
3031 -- If we have an error in any actual or formal, indicated by
3032 -- a type of Any_Type, then abandon resolution attempt, and
3033 -- set result type to Any_Type.
3035 elsif (Present (A) and then Etype (A) = Any_Type)
3036 or else Etype (F) = Any_Type
3038 Set_Etype (N, Any_Type);
3042 -- Case where actual is present
3044 -- If the actual is an entity, generate a reference to it now. We
3045 -- do this before the actual is resolved, because a formal of some
3046 -- protected subprogram, or a task discriminant, will be rewritten
3047 -- during expansion, and the reference to the source entity may
3051 and then Is_Entity_Name (A)
3052 and then Comes_From_Source (N)
3054 Orig_A := Entity (A);
3056 if Present (Orig_A) then
3057 if Is_Formal (Orig_A)
3058 and then Ekind (F) /= E_In_Parameter
3060 Generate_Reference (Orig_A, A, 'm');
3061 elsif not Is_Overloaded (A) then
3062 Generate_Reference (Orig_A, A);
3068 and then (Nkind (Parent (A)) /= N_Parameter_Association
3070 Chars (Selector_Name (Parent (A))) = Chars (F))
3072 -- If style checking mode on, check match of formal name
3075 if Nkind (Parent (A)) = N_Parameter_Association then
3076 Check_Identifier (Selector_Name (Parent (A)), F);
3080 -- If the formal is Out or In_Out, do not resolve and expand the
3081 -- conversion, because it is subsequently expanded into explicit
3082 -- temporaries and assignments. However, the object of the
3083 -- conversion can be resolved. An exception is the case of tagged
3084 -- type conversion with a class-wide actual. In that case we want
3085 -- the tag check to occur and no temporary will be needed (no
3086 -- representation change can occur) and the parameter is passed by
3087 -- reference, so we go ahead and resolve the type conversion.
3088 -- Another exception is the case of reference to component or
3089 -- subcomponent of a bit-packed array, in which case we want to
3090 -- defer expansion to the point the in and out assignments are
3093 if Ekind (F) /= E_In_Parameter
3094 and then Nkind (A) = N_Type_Conversion
3095 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3097 if Ekind (F) = E_In_Out_Parameter
3098 and then Is_Array_Type (Etype (F))
3100 if Has_Aliased_Components (Etype (Expression (A)))
3101 /= Has_Aliased_Components (Etype (F))
3104 -- In a view conversion, the conversion must be legal in
3105 -- both directions, and thus both component types must be
3106 -- aliased, or neither (4.6 (8)).
3108 -- The additional rule 4.6 (24.9.2) seems unduly
3109 -- restrictive: the privacy requirement should not
3110 -- apply to generic types, and should be checked in
3111 -- an instance. ARG query is in order.
3114 ("both component types in a view conversion must be"
3115 & " aliased, or neither", A);
3118 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3120 if Is_By_Reference_Type (Etype (F))
3121 or else Is_By_Reference_Type (Etype (Expression (A)))
3124 ("view conversion between unrelated by reference " &
3125 "array types not allowed (\'A'I-00246)", A);
3128 Comp_Type : constant Entity_Id :=
3130 (Etype (Expression (A)));
3132 if Comes_From_Source (A)
3133 and then Ada_Version >= Ada_05
3135 ((Is_Private_Type (Comp_Type)
3136 and then not Is_Generic_Type (Comp_Type))
3137 or else Is_Tagged_Type (Comp_Type)
3138 or else Is_Volatile (Comp_Type))
3141 ("component type of a view conversion cannot"
3142 & " be private, tagged, or volatile"
3151 if (Conversion_OK (A)
3152 or else Valid_Conversion (A, Etype (A), Expression (A)))
3153 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3155 Resolve (Expression (A));
3158 -- If the actual is a function call that returns a limited
3159 -- unconstrained object that needs finalization, create a
3160 -- transient scope for it, so that it can receive the proper
3161 -- finalization list.
3163 elsif Nkind (A) = N_Function_Call
3164 and then Is_Limited_Record (Etype (F))
3165 and then not Is_Constrained (Etype (F))
3166 and then Expander_Active
3168 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3170 Establish_Transient_Scope (A, False);
3173 if Nkind (A) = N_Type_Conversion
3174 and then Is_Array_Type (Etype (F))
3175 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3177 (Is_Limited_Type (Etype (F))
3178 or else Is_Limited_Type (Etype (Expression (A))))
3181 ("conversion between unrelated limited array types " &
3182 "not allowed (\A\I-00246)", A);
3184 if Is_Limited_Type (Etype (F)) then
3185 Explain_Limited_Type (Etype (F), A);
3188 if Is_Limited_Type (Etype (Expression (A))) then
3189 Explain_Limited_Type (Etype (Expression (A)), A);
3193 -- (Ada 2005: AI-251): If the actual is an allocator whose
3194 -- directly designated type is a class-wide interface, we build
3195 -- an anonymous access type to use it as the type of the
3196 -- allocator. Later, when the subprogram call is expanded, if
3197 -- the interface has a secondary dispatch table the expander
3198 -- will add a type conversion to force the correct displacement
3201 if Nkind (A) = N_Allocator then
3203 DDT : constant Entity_Id :=
3204 Directly_Designated_Type (Base_Type (Etype (F)));
3206 New_Itype : Entity_Id;
3209 if Is_Class_Wide_Type (DDT)
3210 and then Is_Interface (DDT)
3212 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3213 Set_Etype (New_Itype, Etype (A));
3214 Set_Directly_Designated_Type (New_Itype,
3215 Directly_Designated_Type (Etype (A)));
3216 Set_Etype (A, New_Itype);
3219 -- Ada 2005, AI-162:If the actual is an allocator, the
3220 -- innermost enclosing statement is the master of the
3221 -- created object. This needs to be done with expansion
3222 -- enabled only, otherwise the transient scope will not
3223 -- be removed in the expansion of the wrapped construct.
3225 if (Is_Controlled (DDT) or else Has_Task (DDT))
3226 and then Expander_Active
3228 Establish_Transient_Scope (A, False);
3233 -- (Ada 2005): The call may be to a primitive operation of
3234 -- a tagged synchronized type, declared outside of the type.
3235 -- In this case the controlling actual must be converted to
3236 -- its corresponding record type, which is the formal type.
3237 -- The actual may be a subtype, either because of a constraint
3238 -- or because it is a generic actual, so use base type to
3239 -- locate concurrent type.
3241 A_Typ := Base_Type (Etype (A));
3242 F_Typ := Base_Type (Etype (F));
3245 Full_A_Typ : Entity_Id;
3248 if Present (Full_View (A_Typ)) then
3249 Full_A_Typ := Base_Type (Full_View (A_Typ));
3251 Full_A_Typ := A_Typ;
3254 -- Tagged synchronized type (case 1): the actual is a
3257 if Is_Concurrent_Type (A_Typ)
3258 and then Corresponding_Record_Type (A_Typ) = F_Typ
3261 Unchecked_Convert_To
3262 (Corresponding_Record_Type (A_Typ), A));
3263 Resolve (A, Etype (F));
3265 -- Tagged synchronized type (case 2): the formal is a
3268 elsif Ekind (Full_A_Typ) = E_Record_Type
3270 (Corresponding_Concurrent_Type (Full_A_Typ))
3271 and then Is_Concurrent_Type (F_Typ)
3272 and then Present (Corresponding_Record_Type (F_Typ))
3273 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3275 Resolve (A, Corresponding_Record_Type (F_Typ));
3280 Resolve (A, Etype (F));
3288 -- For mode IN, if actual is an entity, and the type of the formal
3289 -- has warnings suppressed, then we reset Never_Set_In_Source for
3290 -- the calling entity. The reason for this is to catch cases like
3291 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3292 -- uses trickery to modify an IN parameter.
3294 if Ekind (F) = E_In_Parameter
3295 and then Is_Entity_Name (A)
3296 and then Present (Entity (A))
3297 and then Ekind (Entity (A)) = E_Variable
3298 and then Has_Warnings_Off (F_Typ)
3300 Set_Never_Set_In_Source (Entity (A), False);
3303 -- Perform error checks for IN and IN OUT parameters
3305 if Ekind (F) /= E_Out_Parameter then
3307 -- Check unset reference. For scalar parameters, it is clearly
3308 -- wrong to pass an uninitialized value as either an IN or
3309 -- IN-OUT parameter. For composites, it is also clearly an
3310 -- error to pass a completely uninitialized value as an IN
3311 -- parameter, but the case of IN OUT is trickier. We prefer
3312 -- not to give a warning here. For example, suppose there is
3313 -- a routine that sets some component of a record to False.
3314 -- It is perfectly reasonable to make this IN-OUT and allow
3315 -- either initialized or uninitialized records to be passed
3318 -- For partially initialized composite values, we also avoid
3319 -- warnings, since it is quite likely that we are passing a
3320 -- partially initialized value and only the initialized fields
3321 -- will in fact be read in the subprogram.
3323 if Is_Scalar_Type (A_Typ)
3324 or else (Ekind (F) = E_In_Parameter
3325 and then not Is_Partially_Initialized_Type (A_Typ))
3327 Check_Unset_Reference (A);
3330 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3331 -- actual to a nested call, since this is case of reading an
3332 -- out parameter, which is not allowed.
3334 if Ada_Version = Ada_83
3335 and then Is_Entity_Name (A)
3336 and then Ekind (Entity (A)) = E_Out_Parameter
3338 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3342 -- Case of OUT or IN OUT parameter
3344 if Ekind (F) /= E_In_Parameter then
3346 -- For an Out parameter, check for useless assignment. Note
3347 -- that we can't set Last_Assignment this early, because we may
3348 -- kill current values in Resolve_Call, and that call would
3349 -- clobber the Last_Assignment field.
3351 -- Note: call Warn_On_Useless_Assignment before doing the check
3352 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3353 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3354 -- reflects the last assignment, not this one!
3356 if Ekind (F) = E_Out_Parameter then
3357 if Warn_On_Modified_As_Out_Parameter (F)
3358 and then Is_Entity_Name (A)
3359 and then Present (Entity (A))
3360 and then Comes_From_Source (N)
3362 Warn_On_Useless_Assignment (Entity (A), A);
3366 -- Validate the form of the actual. Note that the call to
3367 -- Is_OK_Variable_For_Out_Formal generates the required
3368 -- reference in this case.
3370 if not Is_OK_Variable_For_Out_Formal (A) then
3371 Error_Msg_NE ("actual for& must be a variable", A, F);
3374 -- What's the following about???
3376 if Is_Entity_Name (A) then
3377 Kill_Checks (Entity (A));
3383 if Etype (A) = Any_Type then
3384 Set_Etype (N, Any_Type);
3388 -- Apply appropriate range checks for in, out, and in-out
3389 -- parameters. Out and in-out parameters also need a separate
3390 -- check, if there is a type conversion, to make sure the return
3391 -- value meets the constraints of the variable before the
3394 -- Gigi looks at the check flag and uses the appropriate types.
3395 -- For now since one flag is used there is an optimization which
3396 -- might not be done in the In Out case since Gigi does not do
3397 -- any analysis. More thought required about this ???
3399 if Ekind (F) = E_In_Parameter
3400 or else Ekind (F) = E_In_Out_Parameter
3402 if Is_Scalar_Type (Etype (A)) then
3403 Apply_Scalar_Range_Check (A, F_Typ);
3405 elsif Is_Array_Type (Etype (A)) then
3406 Apply_Length_Check (A, F_Typ);
3408 elsif Is_Record_Type (F_Typ)
3409 and then Has_Discriminants (F_Typ)
3410 and then Is_Constrained (F_Typ)
3411 and then (not Is_Derived_Type (F_Typ)
3412 or else Comes_From_Source (Nam))
3414 Apply_Discriminant_Check (A, F_Typ);
3416 elsif Is_Access_Type (F_Typ)
3417 and then Is_Array_Type (Designated_Type (F_Typ))
3418 and then Is_Constrained (Designated_Type (F_Typ))
3420 Apply_Length_Check (A, F_Typ);
3422 elsif Is_Access_Type (F_Typ)
3423 and then Has_Discriminants (Designated_Type (F_Typ))
3424 and then Is_Constrained (Designated_Type (F_Typ))
3426 Apply_Discriminant_Check (A, F_Typ);
3429 Apply_Range_Check (A, F_Typ);
3432 -- Ada 2005 (AI-231)
3434 if Ada_Version >= Ada_05
3435 and then Is_Access_Type (F_Typ)
3436 and then Can_Never_Be_Null (F_Typ)
3437 and then Known_Null (A)
3439 Apply_Compile_Time_Constraint_Error
3441 Msg => "(Ada 2005) null not allowed in "
3442 & "null-excluding formal?",
3443 Reason => CE_Null_Not_Allowed);
3447 if Ekind (F) = E_Out_Parameter
3448 or else Ekind (F) = E_In_Out_Parameter
3450 if Nkind (A) = N_Type_Conversion then
3451 if Is_Scalar_Type (A_Typ) then
3452 Apply_Scalar_Range_Check
3453 (Expression (A), Etype (Expression (A)), A_Typ);
3456 (Expression (A), Etype (Expression (A)), A_Typ);
3460 if Is_Scalar_Type (F_Typ) then
3461 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3463 elsif Is_Array_Type (F_Typ)
3464 and then Ekind (F) = E_Out_Parameter
3466 Apply_Length_Check (A, F_Typ);
3469 Apply_Range_Check (A, A_Typ, F_Typ);
3474 -- An actual associated with an access parameter is implicitly
3475 -- converted to the anonymous access type of the formal and must
3476 -- satisfy the legality checks for access conversions.
3478 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3479 if not Valid_Conversion (A, F_Typ, A) then
3481 ("invalid implicit conversion for access parameter", A);
3485 -- Check bad case of atomic/volatile argument (RM C.6(12))
3487 if Is_By_Reference_Type (Etype (F))
3488 and then Comes_From_Source (N)
3490 if Is_Atomic_Object (A)
3491 and then not Is_Atomic (Etype (F))
3494 ("cannot pass atomic argument to non-atomic formal",
3497 elsif Is_Volatile_Object (A)
3498 and then not Is_Volatile (Etype (F))
3501 ("cannot pass volatile argument to non-volatile formal",
3506 -- Check that subprograms don't have improper controlling
3507 -- arguments (RM 3.9.2 (9))
3509 -- A primitive operation may have an access parameter of an
3510 -- incomplete tagged type, but a dispatching call is illegal
3511 -- if the type is still incomplete.
3513 if Is_Controlling_Formal (F) then
3514 Set_Is_Controlling_Actual (A);
3516 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3518 Desig : constant Entity_Id := Designated_Type (Etype (F));
3520 if Ekind (Desig) = E_Incomplete_Type
3521 and then No (Full_View (Desig))
3522 and then No (Non_Limited_View (Desig))
3525 ("premature use of incomplete type& " &
3526 "in dispatching call", A, Desig);
3531 elsif Nkind (A) = N_Explicit_Dereference then
3532 Validate_Remote_Access_To_Class_Wide_Type (A);
3535 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3536 and then not Is_Class_Wide_Type (F_Typ)
3537 and then not Is_Controlling_Formal (F)
3539 Error_Msg_N ("class-wide argument not allowed here!", A);
3541 if Is_Subprogram (Nam)
3542 and then Comes_From_Source (Nam)
3544 Error_Msg_Node_2 := F_Typ;
3546 ("& is not a dispatching operation of &!", A, Nam);
3549 elsif Is_Access_Type (A_Typ)
3550 and then Is_Access_Type (F_Typ)
3551 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3552 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3553 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3554 or else (Nkind (A) = N_Attribute_Reference
3556 Is_Class_Wide_Type (Etype (Prefix (A)))))
3557 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3558 and then not Is_Controlling_Formal (F)
3561 ("access to class-wide argument not allowed here!", A);
3563 if Is_Subprogram (Nam)
3564 and then Comes_From_Source (Nam)
3566 Error_Msg_Node_2 := Designated_Type (F_Typ);
3568 ("& is not a dispatching operation of &!", A, Nam);
3574 -- If it is a named association, treat the selector_name as
3575 -- a proper identifier, and mark the corresponding entity.
3577 if Nkind (Parent (A)) = N_Parameter_Association then
3578 Set_Entity (Selector_Name (Parent (A)), F);
3579 Generate_Reference (F, Selector_Name (Parent (A)));
3580 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3581 Generate_Reference (F_Typ, N, ' ');
3586 if Ekind (F) /= E_Out_Parameter then
3587 Check_Unset_Reference (A);
3592 -- Case where actual is not present
3600 end Resolve_Actuals;
3602 -----------------------
3603 -- Resolve_Allocator --
3604 -----------------------
3606 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3607 E : constant Node_Id := Expression (N);
3609 Discrim : Entity_Id;
3612 Assoc : Node_Id := Empty;
3615 procedure Check_Allocator_Discrim_Accessibility
3616 (Disc_Exp : Node_Id;
3617 Alloc_Typ : Entity_Id);
3618 -- Check that accessibility level associated with an access discriminant
3619 -- initialized in an allocator by the expression Disc_Exp is not deeper
3620 -- than the level of the allocator type Alloc_Typ. An error message is
3621 -- issued if this condition is violated. Specialized checks are done for
3622 -- the cases of a constraint expression which is an access attribute or
3623 -- an access discriminant.
3625 function In_Dispatching_Context return Boolean;
3626 -- If the allocator is an actual in a call, it is allowed to be class-
3627 -- wide when the context is not because it is a controlling actual.
3629 procedure Propagate_Coextensions (Root : Node_Id);
3630 -- Propagate all nested coextensions which are located one nesting
3631 -- level down the tree to the node Root. Example:
3634 -- Level_1_Coextension
3635 -- Level_2_Coextension
3637 -- The algorithm is paired with delay actions done by the Expander. In
3638 -- the above example, assume all coextensions are controlled types.
3639 -- The cycle of analysis, resolution and expansion will yield:
3641 -- 1) Analyze Top_Record
3642 -- 2) Analyze Level_1_Coextension
3643 -- 3) Analyze Level_2_Coextension
3644 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3646 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3647 -- generated to capture the allocated object. Temp_1 is attached
3648 -- to the coextension chain of Level_2_Coextension.
3649 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3650 -- coextension. A forward tree traversal is performed which finds
3651 -- Level_2_Coextension's list and copies its contents into its
3653 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3654 -- generated to capture the allocated object. Temp_2 is attached
3655 -- to the coextension chain of Level_1_Coextension. Currently, the
3656 -- contents of the list are [Temp_2, Temp_1].
3657 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3658 -- finds Level_1_Coextension's list and copies its contents into
3660 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3661 -- Temp_2 and attach them to Top_Record's finalization list.
3663 -------------------------------------------
3664 -- Check_Allocator_Discrim_Accessibility --
3665 -------------------------------------------
3667 procedure Check_Allocator_Discrim_Accessibility
3668 (Disc_Exp : Node_Id;
3669 Alloc_Typ : Entity_Id)
3672 if Type_Access_Level (Etype (Disc_Exp)) >
3673 Type_Access_Level (Alloc_Typ)
3676 ("operand type has deeper level than allocator type", Disc_Exp);
3678 -- When the expression is an Access attribute the level of the prefix
3679 -- object must not be deeper than that of the allocator's type.
3681 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3682 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3684 and then Object_Access_Level (Prefix (Disc_Exp))
3685 > Type_Access_Level (Alloc_Typ)
3688 ("prefix of attribute has deeper level than allocator type",
3691 -- When the expression is an access discriminant the check is against
3692 -- the level of the prefix object.
3694 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3695 and then Nkind (Disc_Exp) = N_Selected_Component
3696 and then Object_Access_Level (Prefix (Disc_Exp))
3697 > Type_Access_Level (Alloc_Typ)
3700 ("access discriminant has deeper level than allocator type",
3703 -- All other cases are legal
3708 end Check_Allocator_Discrim_Accessibility;
3710 ----------------------------
3711 -- In_Dispatching_Context --
3712 ----------------------------
3714 function In_Dispatching_Context return Boolean is
3715 Par : constant Node_Id := Parent (N);
3717 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3718 and then Is_Entity_Name (Name (Par))
3719 and then Is_Dispatching_Operation (Entity (Name (Par)));
3720 end In_Dispatching_Context;
3722 ----------------------------
3723 -- Propagate_Coextensions --
3724 ----------------------------
3726 procedure Propagate_Coextensions (Root : Node_Id) is
3728 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3729 -- Copy the contents of list From into list To, preserving the
3730 -- order of elements.
3732 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3733 -- Recognize an allocator or a rewritten allocator node and add it
3734 -- along with its nested coextensions to the list of Root.
3740 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3741 From_Elmt : Elmt_Id;
3743 From_Elmt := First_Elmt (From);
3744 while Present (From_Elmt) loop
3745 Append_Elmt (Node (From_Elmt), To);
3746 Next_Elmt (From_Elmt);
3750 -----------------------
3751 -- Process_Allocator --
3752 -----------------------
3754 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3755 Orig_Nod : Node_Id := Nod;
3758 -- This is a possible rewritten subtype indication allocator. Any
3759 -- nested coextensions will appear as discriminant constraints.
3761 if Nkind (Nod) = N_Identifier
3762 and then Present (Original_Node (Nod))
3763 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3767 Discr_Elmt : Elmt_Id;
3770 if Is_Record_Type (Entity (Nod)) then
3772 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3773 while Present (Discr_Elmt) loop
3774 Discr := Node (Discr_Elmt);
3776 if Nkind (Discr) = N_Identifier
3777 and then Present (Original_Node (Discr))
3778 and then Nkind (Original_Node (Discr)) = N_Allocator
3779 and then Present (Coextensions (
3780 Original_Node (Discr)))
3782 if No (Coextensions (Root)) then
3783 Set_Coextensions (Root, New_Elmt_List);
3787 (From => Coextensions (Original_Node (Discr)),
3788 To => Coextensions (Root));
3791 Next_Elmt (Discr_Elmt);
3794 -- There is no need to continue the traversal of this
3795 -- subtree since all the information has already been
3802 -- Case of either a stand alone allocator or a rewritten allocator
3803 -- with an aggregate.
3806 if Present (Original_Node (Nod)) then
3807 Orig_Nod := Original_Node (Nod);
3810 if Nkind (Orig_Nod) = N_Allocator then
3812 -- Propagate the list of nested coextensions to the Root
3813 -- allocator. This is done through list copy since a single
3814 -- allocator may have multiple coextensions. Do not touch
3815 -- coextensions roots.
3817 if not Is_Coextension_Root (Orig_Nod)
3818 and then Present (Coextensions (Orig_Nod))
3820 if No (Coextensions (Root)) then
3821 Set_Coextensions (Root, New_Elmt_List);
3825 (From => Coextensions (Orig_Nod),
3826 To => Coextensions (Root));
3829 -- There is no need to continue the traversal of this
3830 -- subtree since all the information has already been
3837 -- Keep on traversing, looking for the next allocator
3840 end Process_Allocator;
3842 procedure Process_Allocators is
3843 new Traverse_Proc (Process_Allocator);
3845 -- Start of processing for Propagate_Coextensions
3848 Process_Allocators (Expression (Root));
3849 end Propagate_Coextensions;
3851 -- Start of processing for Resolve_Allocator
3854 -- Replace general access with specific type
3856 if Ekind (Etype (N)) = E_Allocator_Type then
3857 Set_Etype (N, Base_Type (Typ));
3860 if Is_Abstract_Type (Typ) then
3861 Error_Msg_N ("type of allocator cannot be abstract", N);
3864 -- For qualified expression, resolve the expression using the
3865 -- given subtype (nothing to do for type mark, subtype indication)
3867 if Nkind (E) = N_Qualified_Expression then
3868 if Is_Class_Wide_Type (Etype (E))
3869 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3870 and then not In_Dispatching_Context
3873 ("class-wide allocator not allowed for this access type", N);
3876 Resolve (Expression (E), Etype (E));
3877 Check_Unset_Reference (Expression (E));
3879 -- A qualified expression requires an exact match of the type,
3880 -- class-wide matching is not allowed.
3882 if (Is_Class_Wide_Type (Etype (Expression (E)))
3883 or else Is_Class_Wide_Type (Etype (E)))
3884 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3886 Wrong_Type (Expression (E), Etype (E));
3889 -- A special accessibility check is needed for allocators that
3890 -- constrain access discriminants. The level of the type of the
3891 -- expression used to constrain an access discriminant cannot be
3892 -- deeper than the type of the allocator (in contrast to access
3893 -- parameters, where the level of the actual can be arbitrary).
3895 -- We can't use Valid_Conversion to perform this check because
3896 -- in general the type of the allocator is unrelated to the type
3897 -- of the access discriminant.
3899 if Ekind (Typ) /= E_Anonymous_Access_Type
3900 or else Is_Local_Anonymous_Access (Typ)
3902 Subtyp := Entity (Subtype_Mark (E));
3904 Aggr := Original_Node (Expression (E));
3906 if Has_Discriminants (Subtyp)
3907 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
3909 Discrim := First_Discriminant (Base_Type (Subtyp));
3911 -- Get the first component expression of the aggregate
3913 if Present (Expressions (Aggr)) then
3914 Disc_Exp := First (Expressions (Aggr));
3916 elsif Present (Component_Associations (Aggr)) then
3917 Assoc := First (Component_Associations (Aggr));
3919 if Present (Assoc) then
3920 Disc_Exp := Expression (Assoc);
3929 while Present (Discrim) and then Present (Disc_Exp) loop
3930 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3931 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
3934 Next_Discriminant (Discrim);
3936 if Present (Discrim) then
3937 if Present (Assoc) then
3939 Disc_Exp := Expression (Assoc);
3941 elsif Present (Next (Disc_Exp)) then
3945 Assoc := First (Component_Associations (Aggr));
3947 if Present (Assoc) then
3948 Disc_Exp := Expression (Assoc);
3958 -- For a subtype mark or subtype indication, freeze the subtype
3961 Freeze_Expression (E);
3963 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
3965 ("initialization required for access-to-constant allocator", N);
3968 -- A special accessibility check is needed for allocators that
3969 -- constrain access discriminants. The level of the type of the
3970 -- expression used to constrain an access discriminant cannot be
3971 -- deeper than the type of the allocator (in contrast to access
3972 -- parameters, where the level of the actual can be arbitrary).
3973 -- We can't use Valid_Conversion to perform this check because
3974 -- in general the type of the allocator is unrelated to the type
3975 -- of the access discriminant.
3977 if Nkind (Original_Node (E)) = N_Subtype_Indication
3978 and then (Ekind (Typ) /= E_Anonymous_Access_Type
3979 or else Is_Local_Anonymous_Access (Typ))
3981 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
3983 if Has_Discriminants (Subtyp) then
3984 Discrim := First_Discriminant (Base_Type (Subtyp));
3985 Constr := First (Constraints (Constraint (Original_Node (E))));
3986 while Present (Discrim) and then Present (Constr) loop
3987 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3988 if Nkind (Constr) = N_Discriminant_Association then
3989 Disc_Exp := Original_Node (Expression (Constr));
3991 Disc_Exp := Original_Node (Constr);
3994 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
3997 Next_Discriminant (Discrim);
4004 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4005 -- check that the level of the type of the created object is not deeper
4006 -- than the level of the allocator's access type, since extensions can
4007 -- now occur at deeper levels than their ancestor types. This is a
4008 -- static accessibility level check; a run-time check is also needed in
4009 -- the case of an initialized allocator with a class-wide argument (see
4010 -- Expand_Allocator_Expression).
4012 if Ada_Version >= Ada_05
4013 and then Is_Class_Wide_Type (Designated_Type (Typ))
4016 Exp_Typ : Entity_Id;
4019 if Nkind (E) = N_Qualified_Expression then
4020 Exp_Typ := Etype (E);
4021 elsif Nkind (E) = N_Subtype_Indication then
4022 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4024 Exp_Typ := Entity (E);
4027 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4028 if In_Instance_Body then
4029 Error_Msg_N ("?type in allocator has deeper level than" &
4030 " designated class-wide type", E);
4031 Error_Msg_N ("\?Program_Error will be raised at run time",
4034 Make_Raise_Program_Error (Sloc (N),
4035 Reason => PE_Accessibility_Check_Failed));
4038 -- Do not apply Ada 2005 accessibility checks on a class-wide
4039 -- allocator if the type given in the allocator is a formal
4040 -- type. A run-time check will be performed in the instance.
4042 elsif not Is_Generic_Type (Exp_Typ) then
4043 Error_Msg_N ("type in allocator has deeper level than" &
4044 " designated class-wide type", E);
4050 -- Check for allocation from an empty storage pool
4052 if No_Pool_Assigned (Typ) then
4054 Loc : constant Source_Ptr := Sloc (N);
4056 Error_Msg_N ("?allocation from empty storage pool!", N);
4057 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4059 Make_Raise_Storage_Error (Loc,
4060 Reason => SE_Empty_Storage_Pool));
4063 -- If the context is an unchecked conversion, as may happen within
4064 -- an inlined subprogram, the allocator is being resolved with its
4065 -- own anonymous type. In that case, if the target type has a specific
4066 -- storage pool, it must be inherited explicitly by the allocator type.
4068 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4069 and then No (Associated_Storage_Pool (Typ))
4071 Set_Associated_Storage_Pool
4072 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4075 -- An erroneous allocator may be rewritten as a raise Program_Error
4078 if Nkind (N) = N_Allocator then
4080 -- An anonymous access discriminant is the definition of a
4083 if Ekind (Typ) = E_Anonymous_Access_Type
4084 and then Nkind (Associated_Node_For_Itype (Typ)) =
4085 N_Discriminant_Specification
4087 -- Avoid marking an allocator as a dynamic coextension if it is
4088 -- within a static construct.
4090 if not Is_Static_Coextension (N) then
4091 Set_Is_Dynamic_Coextension (N);
4094 -- Cleanup for potential static coextensions
4097 Set_Is_Dynamic_Coextension (N, False);
4098 Set_Is_Static_Coextension (N, False);
4101 -- There is no need to propagate any nested coextensions if they
4102 -- are marked as static since they will be rewritten on the spot.
4104 if not Is_Static_Coextension (N) then
4105 Propagate_Coextensions (N);
4108 end Resolve_Allocator;
4110 ---------------------------
4111 -- Resolve_Arithmetic_Op --
4112 ---------------------------
4114 -- Used for resolving all arithmetic operators except exponentiation
4116 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4117 L : constant Node_Id := Left_Opnd (N);
4118 R : constant Node_Id := Right_Opnd (N);
4119 TL : constant Entity_Id := Base_Type (Etype (L));
4120 TR : constant Entity_Id := Base_Type (Etype (R));
4124 B_Typ : constant Entity_Id := Base_Type (Typ);
4125 -- We do the resolution using the base type, because intermediate values
4126 -- in expressions always are of the base type, not a subtype of it.
4128 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4129 -- Returns True if N is in a context that expects "any real type"
4131 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4132 -- Return True iff given type is Integer or universal real/integer
4134 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4135 -- Choose type of integer literal in fixed-point operation to conform
4136 -- to available fixed-point type. T is the type of the other operand,
4137 -- which is needed to determine the expected type of N.
4139 procedure Set_Operand_Type (N : Node_Id);
4140 -- Set operand type to T if universal
4142 -------------------------------
4143 -- Expected_Type_Is_Any_Real --
4144 -------------------------------
4146 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4148 -- N is the expression after "delta" in a fixed_point_definition;
4151 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4152 N_Decimal_Fixed_Point_Definition,
4154 -- N is one of the bounds in a real_range_specification;
4157 N_Real_Range_Specification,
4159 -- N is the expression of a delta_constraint;
4162 N_Delta_Constraint);
4163 end Expected_Type_Is_Any_Real;
4165 -----------------------------
4166 -- Is_Integer_Or_Universal --
4167 -----------------------------
4169 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4171 Index : Interp_Index;
4175 if not Is_Overloaded (N) then
4177 return Base_Type (T) = Base_Type (Standard_Integer)
4178 or else T = Universal_Integer
4179 or else T = Universal_Real;
4181 Get_First_Interp (N, Index, It);
4182 while Present (It.Typ) loop
4183 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4184 or else It.Typ = Universal_Integer
4185 or else It.Typ = Universal_Real
4190 Get_Next_Interp (Index, It);
4195 end Is_Integer_Or_Universal;
4197 ----------------------------
4198 -- Set_Mixed_Mode_Operand --
4199 ----------------------------
4201 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4202 Index : Interp_Index;
4206 if Universal_Interpretation (N) = Universal_Integer then
4208 -- A universal integer literal is resolved as standard integer
4209 -- except in the case of a fixed-point result, where we leave it
4210 -- as universal (to be handled by Exp_Fixd later on)
4212 if Is_Fixed_Point_Type (T) then
4213 Resolve (N, Universal_Integer);
4215 Resolve (N, Standard_Integer);
4218 elsif Universal_Interpretation (N) = Universal_Real
4219 and then (T = Base_Type (Standard_Integer)
4220 or else T = Universal_Integer
4221 or else T = Universal_Real)
4223 -- A universal real can appear in a fixed-type context. We resolve
4224 -- the literal with that context, even though this might raise an
4225 -- exception prematurely (the other operand may be zero).
4229 elsif Etype (N) = Base_Type (Standard_Integer)
4230 and then T = Universal_Real
4231 and then Is_Overloaded (N)
4233 -- Integer arg in mixed-mode operation. Resolve with universal
4234 -- type, in case preference rule must be applied.
4236 Resolve (N, Universal_Integer);
4239 and then B_Typ /= Universal_Fixed
4241 -- Not a mixed-mode operation, resolve with context
4245 elsif Etype (N) = Any_Fixed then
4247 -- N may itself be a mixed-mode operation, so use context type
4251 elsif Is_Fixed_Point_Type (T)
4252 and then B_Typ = Universal_Fixed
4253 and then Is_Overloaded (N)
4255 -- Must be (fixed * fixed) operation, operand must have one
4256 -- compatible interpretation.
4258 Resolve (N, Any_Fixed);
4260 elsif Is_Fixed_Point_Type (B_Typ)
4261 and then (T = Universal_Real
4262 or else Is_Fixed_Point_Type (T))
4263 and then Is_Overloaded (N)
4265 -- C * F(X) in a fixed context, where C is a real literal or a
4266 -- fixed-point expression. F must have either a fixed type
4267 -- interpretation or an integer interpretation, but not both.
4269 Get_First_Interp (N, Index, It);
4270 while Present (It.Typ) loop
4271 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4273 if Analyzed (N) then
4274 Error_Msg_N ("ambiguous operand in fixed operation", N);
4276 Resolve (N, Standard_Integer);
4279 elsif Is_Fixed_Point_Type (It.Typ) then
4281 if Analyzed (N) then
4282 Error_Msg_N ("ambiguous operand in fixed operation", N);
4284 Resolve (N, It.Typ);
4288 Get_Next_Interp (Index, It);
4291 -- Reanalyze the literal with the fixed type of the context. If
4292 -- context is Universal_Fixed, we are within a conversion, leave
4293 -- the literal as a universal real because there is no usable
4294 -- fixed type, and the target of the conversion plays no role in
4308 if B_Typ = Universal_Fixed
4309 and then Nkind (Op2) = N_Real_Literal
4311 T2 := Universal_Real;
4316 Set_Analyzed (Op2, False);
4323 end Set_Mixed_Mode_Operand;
4325 ----------------------
4326 -- Set_Operand_Type --
4327 ----------------------
4329 procedure Set_Operand_Type (N : Node_Id) is
4331 if Etype (N) = Universal_Integer
4332 or else Etype (N) = Universal_Real
4336 end Set_Operand_Type;
4338 -- Start of processing for Resolve_Arithmetic_Op
4341 if Comes_From_Source (N)
4342 and then Ekind (Entity (N)) = E_Function
4343 and then Is_Imported (Entity (N))
4344 and then Is_Intrinsic_Subprogram (Entity (N))
4346 Resolve_Intrinsic_Operator (N, Typ);
4349 -- Special-case for mixed-mode universal expressions or fixed point
4350 -- type operation: each argument is resolved separately. The same
4351 -- treatment is required if one of the operands of a fixed point
4352 -- operation is universal real, since in this case we don't do a
4353 -- conversion to a specific fixed-point type (instead the expander
4354 -- takes care of the case).
4356 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4357 and then Present (Universal_Interpretation (L))
4358 and then Present (Universal_Interpretation (R))
4360 Resolve (L, Universal_Interpretation (L));
4361 Resolve (R, Universal_Interpretation (R));
4362 Set_Etype (N, B_Typ);
4364 elsif (B_Typ = Universal_Real
4365 or else Etype (N) = Universal_Fixed
4366 or else (Etype (N) = Any_Fixed
4367 and then Is_Fixed_Point_Type (B_Typ))
4368 or else (Is_Fixed_Point_Type (B_Typ)
4369 and then (Is_Integer_Or_Universal (L)
4371 Is_Integer_Or_Universal (R))))
4372 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4374 if TL = Universal_Integer or else TR = Universal_Integer then
4375 Check_For_Visible_Operator (N, B_Typ);
4378 -- If context is a fixed type and one operand is integer, the
4379 -- other is resolved with the type of the context.
4381 if Is_Fixed_Point_Type (B_Typ)
4382 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4383 or else TL = Universal_Integer)
4388 elsif Is_Fixed_Point_Type (B_Typ)
4389 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4390 or else TR = Universal_Integer)
4396 Set_Mixed_Mode_Operand (L, TR);
4397 Set_Mixed_Mode_Operand (R, TL);
4400 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4401 -- multiplying operators from being used when the expected type is
4402 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4403 -- some cases where the expected type is actually Any_Real;
4404 -- Expected_Type_Is_Any_Real takes care of that case.
4406 if Etype (N) = Universal_Fixed
4407 or else Etype (N) = Any_Fixed
4409 if B_Typ = Universal_Fixed
4410 and then not Expected_Type_Is_Any_Real (N)
4411 and then not Nkind_In (Parent (N), N_Type_Conversion,
4412 N_Unchecked_Type_Conversion)
4414 Error_Msg_N ("type cannot be determined from context!", N);
4415 Error_Msg_N ("\explicit conversion to result type required", N);
4417 Set_Etype (L, Any_Type);
4418 Set_Etype (R, Any_Type);
4421 if Ada_Version = Ada_83
4422 and then Etype (N) = Universal_Fixed
4424 Nkind_In (Parent (N), N_Type_Conversion,
4425 N_Unchecked_Type_Conversion)
4428 ("(Ada 83) fixed-point operation "
4429 & "needs explicit conversion", N);
4432 -- The expected type is "any real type" in contexts like
4433 -- type T is delta <universal_fixed-expression> ...
4434 -- in which case we need to set the type to Universal_Real
4435 -- so that static expression evaluation will work properly.
4437 if Expected_Type_Is_Any_Real (N) then
4438 Set_Etype (N, Universal_Real);
4440 Set_Etype (N, B_Typ);
4444 elsif Is_Fixed_Point_Type (B_Typ)
4445 and then (Is_Integer_Or_Universal (L)
4446 or else Nkind (L) = N_Real_Literal
4447 or else Nkind (R) = N_Real_Literal
4448 or else Is_Integer_Or_Universal (R))
4450 Set_Etype (N, B_Typ);
4452 elsif Etype (N) = Any_Fixed then
4454 -- If no previous errors, this is only possible if one operand
4455 -- is overloaded and the context is universal. Resolve as such.
4457 Set_Etype (N, B_Typ);
4461 if (TL = Universal_Integer or else TL = Universal_Real)
4463 (TR = Universal_Integer or else TR = Universal_Real)
4465 Check_For_Visible_Operator (N, B_Typ);
4468 -- If the context is Universal_Fixed and the operands are also
4469 -- universal fixed, this is an error, unless there is only one
4470 -- applicable fixed_point type (usually duration).
4472 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4473 T := Unique_Fixed_Point_Type (N);
4475 if T = Any_Type then
4488 -- If one of the arguments was resolved to a non-universal type.
4489 -- label the result of the operation itself with the same type.
4490 -- Do the same for the universal argument, if any.
4492 T := Intersect_Types (L, R);
4493 Set_Etype (N, Base_Type (T));
4494 Set_Operand_Type (L);
4495 Set_Operand_Type (R);
4498 Generate_Operator_Reference (N, Typ);
4499 Eval_Arithmetic_Op (N);
4501 -- Set overflow and division checking bit. Much cleverer code needed
4502 -- here eventually and perhaps the Resolve routines should be separated
4503 -- for the various arithmetic operations, since they will need
4504 -- different processing. ???
4506 if Nkind (N) in N_Op then
4507 if not Overflow_Checks_Suppressed (Etype (N)) then
4508 Enable_Overflow_Check (N);
4511 -- Give warning if explicit division by zero
4513 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4514 and then not Division_Checks_Suppressed (Etype (N))
4516 Rop := Right_Opnd (N);
4518 if Compile_Time_Known_Value (Rop)
4519 and then ((Is_Integer_Type (Etype (Rop))
4520 and then Expr_Value (Rop) = Uint_0)
4522 (Is_Real_Type (Etype (Rop))
4523 and then Expr_Value_R (Rop) = Ureal_0))
4525 -- Specialize the warning message according to the operation
4529 Apply_Compile_Time_Constraint_Error
4530 (N, "division by zero?", CE_Divide_By_Zero,
4531 Loc => Sloc (Right_Opnd (N)));
4534 Apply_Compile_Time_Constraint_Error
4535 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4536 Loc => Sloc (Right_Opnd (N)));
4539 Apply_Compile_Time_Constraint_Error
4540 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4541 Loc => Sloc (Right_Opnd (N)));
4543 -- Division by zero can only happen with division, rem,
4544 -- and mod operations.
4547 raise Program_Error;
4550 -- Otherwise just set the flag to check at run time
4553 Activate_Division_Check (N);
4557 -- If Restriction No_Implicit_Conditionals is active, then it is
4558 -- violated if either operand can be negative for mod, or for rem
4559 -- if both operands can be negative.
4561 if Restrictions.Set (No_Implicit_Conditionals)
4562 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4571 -- Set if corresponding operand might be negative
4574 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4575 LNeg := (not OK) or else Lo < 0;
4577 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4578 RNeg := (not OK) or else Lo < 0;
4580 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4582 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4584 Check_Restriction (No_Implicit_Conditionals, N);
4590 Check_Unset_Reference (L);
4591 Check_Unset_Reference (R);
4592 end Resolve_Arithmetic_Op;
4598 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4599 Loc : constant Source_Ptr := Sloc (N);
4600 Subp : constant Node_Id := Name (N);
4609 -- The context imposes a unique interpretation with type Typ on a
4610 -- procedure or function call. Find the entity of the subprogram that
4611 -- yields the expected type, and propagate the corresponding formal
4612 -- constraints on the actuals. The caller has established that an
4613 -- interpretation exists, and emitted an error if not unique.
4615 -- First deal with the case of a call to an access-to-subprogram,
4616 -- dereference made explicit in Analyze_Call.
4618 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4619 if not Is_Overloaded (Subp) then
4620 Nam := Etype (Subp);
4623 -- Find the interpretation whose type (a subprogram type) has a
4624 -- return type that is compatible with the context. Analysis of
4625 -- the node has established that one exists.
4629 Get_First_Interp (Subp, I, It);
4630 while Present (It.Typ) loop
4631 if Covers (Typ, Etype (It.Typ)) then
4636 Get_Next_Interp (I, It);
4640 raise Program_Error;
4644 -- If the prefix is not an entity, then resolve it
4646 if not Is_Entity_Name (Subp) then
4647 Resolve (Subp, Nam);
4650 -- For an indirect call, we always invalidate checks, since we do not
4651 -- know whether the subprogram is local or global. Yes we could do
4652 -- better here, e.g. by knowing that there are no local subprograms,
4653 -- but it does not seem worth the effort. Similarly, we kill all
4654 -- knowledge of current constant values.
4656 Kill_Current_Values;
4658 -- If this is a procedure call which is really an entry call, do
4659 -- the conversion of the procedure call to an entry call. Protected
4660 -- operations use the same circuitry because the name in the call
4661 -- can be an arbitrary expression with special resolution rules.
4663 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4664 or else (Is_Entity_Name (Subp)
4665 and then Ekind (Entity (Subp)) = E_Entry)
4667 Resolve_Entry_Call (N, Typ);
4668 Check_Elab_Call (N);
4670 -- Kill checks and constant values, as above for indirect case
4671 -- Who knows what happens when another task is activated?
4673 Kill_Current_Values;
4676 -- Normal subprogram call with name established in Resolve
4678 elsif not (Is_Type (Entity (Subp))) then
4679 Nam := Entity (Subp);
4680 Set_Entity_With_Style_Check (Subp, Nam);
4682 -- Otherwise we must have the case of an overloaded call
4685 pragma Assert (Is_Overloaded (Subp));
4686 Nam := Empty; -- We know that it will be assigned in loop below
4688 Get_First_Interp (Subp, I, It);
4689 while Present (It.Typ) loop
4690 if Covers (Typ, It.Typ) then
4692 Set_Entity_With_Style_Check (Subp, Nam);
4696 Get_Next_Interp (I, It);
4700 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4701 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4702 and then Nkind (Subp) /= N_Explicit_Dereference
4703 and then Present (Parameter_Associations (N))
4705 -- The prefix is a parameterless function call that returns an access
4706 -- to subprogram. If parameters are present in the current call, add
4707 -- add an explicit dereference. We use the base type here because
4708 -- within an instance these may be subtypes.
4710 -- The dereference is added either in Analyze_Call or here. Should
4711 -- be consolidated ???
4713 Set_Is_Overloaded (Subp, False);
4714 Set_Etype (Subp, Etype (Nam));
4715 Insert_Explicit_Dereference (Subp);
4716 Nam := Designated_Type (Etype (Nam));
4717 Resolve (Subp, Nam);
4720 -- Check that a call to Current_Task does not occur in an entry body
4722 if Is_RTE (Nam, RE_Current_Task) then
4731 -- Exclude calls that occur within the default of a formal
4732 -- parameter of the entry, since those are evaluated outside
4735 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4737 if Nkind (P) = N_Entry_Body
4738 or else (Nkind (P) = N_Subprogram_Body
4739 and then Is_Entry_Barrier_Function (P))
4743 ("?& should not be used in entry body (RM C.7(17))",
4746 ("\Program_Error will be raised at run time?", N, Nam);
4748 Make_Raise_Program_Error (Loc,
4749 Reason => PE_Current_Task_In_Entry_Body));
4750 Set_Etype (N, Rtype);
4757 -- Check that a procedure call does not occur in the context of the
4758 -- entry call statement of a conditional or timed entry call. Note that
4759 -- the case of a call to a subprogram renaming of an entry will also be
4760 -- rejected. The test for N not being an N_Entry_Call_Statement is
4761 -- defensive, covering the possibility that the processing of entry
4762 -- calls might reach this point due to later modifications of the code
4765 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4766 and then Nkind (N) /= N_Entry_Call_Statement
4767 and then Entry_Call_Statement (Parent (N)) = N
4769 if Ada_Version < Ada_05 then
4770 Error_Msg_N ("entry call required in select statement", N);
4772 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4773 -- for a procedure_or_entry_call, the procedure_name or
4774 -- procedure_prefix of the procedure_call_statement shall denote
4775 -- an entry renamed by a procedure, or (a view of) a primitive
4776 -- subprogram of a limited interface whose first parameter is
4777 -- a controlling parameter.
4779 elsif Nkind (N) = N_Procedure_Call_Statement
4780 and then not Is_Renamed_Entry (Nam)
4781 and then not Is_Controlling_Limited_Procedure (Nam)
4784 ("entry call or dispatching primitive of interface required", N);
4788 -- Check that this is not a call to a protected procedure or entry from
4789 -- within a protected function.
4791 if Ekind (Current_Scope) = E_Function
4792 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4793 and then Ekind (Nam) /= E_Function
4794 and then Scope (Nam) = Scope (Current_Scope)
4796 Error_Msg_N ("within protected function, protected " &
4797 "object is constant", N);
4798 Error_Msg_N ("\cannot call operation that may modify it", N);
4801 -- Freeze the subprogram name if not in a spec-expression. Note that we
4802 -- freeze procedure calls as well as function calls. Procedure calls are
4803 -- not frozen according to the rules (RM 13.14(14)) because it is
4804 -- impossible to have a procedure call to a non-frozen procedure in pure
4805 -- Ada, but in the code that we generate in the expander, this rule
4806 -- needs extending because we can generate procedure calls that need
4809 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4810 Freeze_Expression (Subp);
4813 -- For a predefined operator, the type of the result is the type imposed
4814 -- by context, except for a predefined operation on universal fixed.
4815 -- Otherwise The type of the call is the type returned by the subprogram
4818 if Is_Predefined_Op (Nam) then
4819 if Etype (N) /= Universal_Fixed then
4823 -- If the subprogram returns an array type, and the context requires the
4824 -- component type of that array type, the node is really an indexing of
4825 -- the parameterless call. Resolve as such. A pathological case occurs
4826 -- when the type of the component is an access to the array type. In
4827 -- this case the call is truly ambiguous.
4829 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4831 ((Is_Array_Type (Etype (Nam))
4832 and then Covers (Typ, Component_Type (Etype (Nam))))
4833 or else (Is_Access_Type (Etype (Nam))
4834 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4837 Component_Type (Designated_Type (Etype (Nam))))))
4840 Index_Node : Node_Id;
4842 Ret_Type : constant Entity_Id := Etype (Nam);
4845 if Is_Access_Type (Ret_Type)
4846 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4849 ("cannot disambiguate function call and indexing", N);
4851 New_Subp := Relocate_Node (Subp);
4852 Set_Entity (Subp, Nam);
4854 if Component_Type (Ret_Type) /= Any_Type then
4855 if Needs_No_Actuals (Nam) then
4857 -- Indexed call to a parameterless function
4860 Make_Indexed_Component (Loc,
4862 Make_Function_Call (Loc,
4864 Expressions => Parameter_Associations (N));
4866 -- An Ada 2005 prefixed call to a primitive operation
4867 -- whose first parameter is the prefix. This prefix was
4868 -- prepended to the parameter list, which is actually a
4869 -- list of indices. Remove the prefix in order to build
4870 -- the proper indexed component.
4873 Make_Indexed_Component (Loc,
4875 Make_Function_Call (Loc,
4877 Parameter_Associations =>
4879 (Remove_Head (Parameter_Associations (N)))),
4880 Expressions => Parameter_Associations (N));
4883 -- Since we are correcting a node classification error made
4884 -- by the parser, we call Replace rather than Rewrite.
4886 Replace (N, Index_Node);
4887 Set_Etype (Prefix (N), Ret_Type);
4889 Resolve_Indexed_Component (N, Typ);
4890 Check_Elab_Call (Prefix (N));
4898 Set_Etype (N, Etype (Nam));
4901 -- In the case where the call is to an overloaded subprogram, Analyze
4902 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
4903 -- such a case Normalize_Actuals needs to be called once more to order
4904 -- the actuals correctly. Otherwise the call will have the ordering
4905 -- given by the last overloaded subprogram whether this is the correct
4906 -- one being called or not.
4908 if Is_Overloaded (Subp) then
4909 Normalize_Actuals (N, Nam, False, Norm_OK);
4910 pragma Assert (Norm_OK);
4913 -- In any case, call is fully resolved now. Reset Overload flag, to
4914 -- prevent subsequent overload resolution if node is analyzed again
4916 Set_Is_Overloaded (Subp, False);
4917 Set_Is_Overloaded (N, False);
4919 -- If we are calling the current subprogram from immediately within its
4920 -- body, then that is the case where we can sometimes detect cases of
4921 -- infinite recursion statically. Do not try this in case restriction
4922 -- No_Recursion is in effect anyway, and do it only for source calls.
4924 if Comes_From_Source (N) then
4925 Scop := Current_Scope;
4927 -- Issue warning for possible infinite recursion in the absence
4928 -- of the No_Recursion restriction.
4931 and then not Restriction_Active (No_Recursion)
4932 and then Check_Infinite_Recursion (N)
4934 -- Here we detected and flagged an infinite recursion, so we do
4935 -- not need to test the case below for further warnings. Also if
4936 -- we now have a raise SE node, we are all done.
4938 if Nkind (N) = N_Raise_Storage_Error then
4942 -- If call is to immediately containing subprogram, then check for
4943 -- the case of a possible run-time detectable infinite recursion.
4946 Scope_Loop : while Scop /= Standard_Standard loop
4949 -- Although in general case, recursion is not statically
4950 -- checkable, the case of calling an immediately containing
4951 -- subprogram is easy to catch.
4953 Check_Restriction (No_Recursion, N);
4955 -- If the recursive call is to a parameterless subprogram,
4956 -- then even if we can't statically detect infinite
4957 -- recursion, this is pretty suspicious, and we output a
4958 -- warning. Furthermore, we will try later to detect some
4959 -- cases here at run time by expanding checking code (see
4960 -- Detect_Infinite_Recursion in package Exp_Ch6).
4962 -- If the recursive call is within a handler, do not emit a
4963 -- warning, because this is a common idiom: loop until input
4964 -- is correct, catch illegal input in handler and restart.
4966 if No (First_Formal (Nam))
4967 and then Etype (Nam) = Standard_Void_Type
4968 and then not Error_Posted (N)
4969 and then Nkind (Parent (N)) /= N_Exception_Handler
4971 -- For the case of a procedure call. We give the message
4972 -- only if the call is the first statement in a sequence
4973 -- of statements, or if all previous statements are
4974 -- simple assignments. This is simply a heuristic to
4975 -- decrease false positives, without losing too many good
4976 -- warnings. The idea is that these previous statements
4977 -- may affect global variables the procedure depends on.
4979 if Nkind (N) = N_Procedure_Call_Statement
4980 and then Is_List_Member (N)
4986 while Present (P) loop
4987 if Nkind (P) /= N_Assignment_Statement then
4996 -- Do not give warning if we are in a conditional context
4999 K : constant Node_Kind := Nkind (Parent (N));
5001 if (K = N_Loop_Statement
5002 and then Present (Iteration_Scheme (Parent (N))))
5003 or else K = N_If_Statement
5004 or else K = N_Elsif_Part
5005 or else K = N_Case_Statement_Alternative
5011 -- Here warning is to be issued
5013 Set_Has_Recursive_Call (Nam);
5015 ("?possible infinite recursion!", N);
5017 ("\?Storage_Error may be raised at run time!", N);
5023 Scop := Scope (Scop);
5024 end loop Scope_Loop;
5028 -- If subprogram name is a predefined operator, it was given in
5029 -- functional notation. Replace call node with operator node, so
5030 -- that actuals can be resolved appropriately.
5032 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5033 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5036 elsif Present (Alias (Nam))
5037 and then Is_Predefined_Op (Alias (Nam))
5039 Resolve_Actuals (N, Nam);
5040 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5044 -- Create a transient scope if the resulting type requires it
5046 -- There are several notable exceptions:
5048 -- a) In init procs, the transient scope overhead is not needed, and is
5049 -- even incorrect when the call is a nested initialization call for a
5050 -- component whose expansion may generate adjust calls. However, if the
5051 -- call is some other procedure call within an initialization procedure
5052 -- (for example a call to Create_Task in the init_proc of the task
5053 -- run-time record) a transient scope must be created around this call.
5055 -- b) Enumeration literal pseudo-calls need no transient scope
5057 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5058 -- functions) do not use the secondary stack even though the return
5059 -- type may be unconstrained.
5061 -- d) Calls to a build-in-place function, since such functions may
5062 -- allocate their result directly in a target object, and cases where
5063 -- the result does get allocated in the secondary stack are checked for
5064 -- within the specialized Exp_Ch6 procedures for expanding those
5065 -- build-in-place calls.
5067 -- e) If the subprogram is marked Inline_Always, then even if it returns
5068 -- an unconstrained type the call does not require use of the secondary
5069 -- stack. However, inlining will only take place if the body to inline
5070 -- is already present. It may not be available if e.g. the subprogram is
5071 -- declared in a child instance.
5073 -- If this is an initialization call for a type whose construction
5074 -- uses the secondary stack, and it is not a nested call to initialize
5075 -- a component, we do need to create a transient scope for it. We
5076 -- check for this by traversing the type in Check_Initialization_Call.
5079 and then Has_Pragma_Inline_Always (Nam)
5080 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5081 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5085 elsif Ekind (Nam) = E_Enumeration_Literal
5086 or else Is_Build_In_Place_Function (Nam)
5087 or else Is_Intrinsic_Subprogram (Nam)
5091 elsif Expander_Active
5092 and then Is_Type (Etype (Nam))
5093 and then Requires_Transient_Scope (Etype (Nam))
5095 (not Within_Init_Proc
5097 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5099 Establish_Transient_Scope (N, Sec_Stack => True);
5101 -- If the call appears within the bounds of a loop, it will
5102 -- be rewritten and reanalyzed, nothing left to do here.
5104 if Nkind (N) /= N_Function_Call then
5108 elsif Is_Init_Proc (Nam)
5109 and then not Within_Init_Proc
5111 Check_Initialization_Call (N, Nam);
5114 -- A protected function cannot be called within the definition of the
5115 -- enclosing protected type.
5117 if Is_Protected_Type (Scope (Nam))
5118 and then In_Open_Scopes (Scope (Nam))
5119 and then not Has_Completion (Scope (Nam))
5122 ("& cannot be called before end of protected definition", N, Nam);
5125 -- Propagate interpretation to actuals, and add default expressions
5128 if Present (First_Formal (Nam)) then
5129 Resolve_Actuals (N, Nam);
5131 -- Overloaded literals are rewritten as function calls, for
5132 -- purpose of resolution. After resolution, we can replace
5133 -- the call with the literal itself.
5135 elsif Ekind (Nam) = E_Enumeration_Literal then
5136 Copy_Node (Subp, N);
5137 Resolve_Entity_Name (N, Typ);
5139 -- Avoid validation, since it is a static function call
5141 Generate_Reference (Nam, Subp);
5145 -- If the subprogram is not global, then kill all saved values and
5146 -- checks. This is a bit conservative, since in many cases we could do
5147 -- better, but it is not worth the effort. Similarly, we kill constant
5148 -- values. However we do not need to do this for internal entities
5149 -- (unless they are inherited user-defined subprograms), since they
5150 -- are not in the business of molesting local values.
5152 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5153 -- kill all checks and values for calls to global subprograms. This
5154 -- takes care of the case where an access to a local subprogram is
5155 -- taken, and could be passed directly or indirectly and then called
5156 -- from almost any context.
5158 -- Note: we do not do this step till after resolving the actuals. That
5159 -- way we still take advantage of the current value information while
5160 -- scanning the actuals.
5162 -- We suppress killing values if we are processing the nodes associated
5163 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5164 -- type kills all the values as part of analyzing the code that
5165 -- initializes the dispatch tables.
5167 if Inside_Freezing_Actions = 0
5168 and then (not Is_Library_Level_Entity (Nam)
5169 or else Suppress_Value_Tracking_On_Call
5170 (Nearest_Dynamic_Scope (Current_Scope)))
5171 and then (Comes_From_Source (Nam)
5172 or else (Present (Alias (Nam))
5173 and then Comes_From_Source (Alias (Nam))))
5175 Kill_Current_Values;
5178 -- If we are warning about unread OUT parameters, this is the place to
5179 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5180 -- after the above call to Kill_Current_Values (since that call clears
5181 -- the Last_Assignment field of all local variables).
5183 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5184 and then Comes_From_Source (N)
5185 and then In_Extended_Main_Source_Unit (N)
5192 F := First_Formal (Nam);
5193 A := First_Actual (N);
5194 while Present (F) and then Present (A) loop
5195 if (Ekind (F) = E_Out_Parameter
5196 or else Ekind (F) = E_In_Out_Parameter)
5197 and then Warn_On_Modified_As_Out_Parameter (F)
5198 and then Is_Entity_Name (A)
5199 and then Present (Entity (A))
5200 and then Comes_From_Source (N)
5201 and then Safe_To_Capture_Value (N, Entity (A))
5203 Set_Last_Assignment (Entity (A), A);
5212 -- If the subprogram is a primitive operation, check whether or not
5213 -- it is a correct dispatching call.
5215 if Is_Overloadable (Nam)
5216 and then Is_Dispatching_Operation (Nam)
5218 Check_Dispatching_Call (N);
5220 elsif Ekind (Nam) /= E_Subprogram_Type
5221 and then Is_Abstract_Subprogram (Nam)
5222 and then not In_Instance
5224 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5227 -- If this is a dispatching call, generate the appropriate reference,
5228 -- for better source navigation in GPS.
5230 if Is_Overloadable (Nam)
5231 and then Present (Controlling_Argument (N))
5233 Generate_Reference (Nam, Subp, 'R');
5235 -- Normal case, not a dispatching call
5238 Generate_Reference (Nam, Subp);
5241 if Is_Intrinsic_Subprogram (Nam) then
5242 Check_Intrinsic_Call (N);
5245 -- Check for violation of restriction No_Specific_Termination_Handlers
5246 -- and warn on a potentially blocking call to Abort_Task.
5248 if Is_RTE (Nam, RE_Set_Specific_Handler)
5250 Is_RTE (Nam, RE_Specific_Handler)
5252 Check_Restriction (No_Specific_Termination_Handlers, N);
5254 elsif Is_RTE (Nam, RE_Abort_Task) then
5255 Check_Potentially_Blocking_Operation (N);
5258 -- All done, evaluate call and deal with elaboration issues
5261 Check_Elab_Call (N);
5264 -------------------------------
5265 -- Resolve_Character_Literal --
5266 -------------------------------
5268 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5269 B_Typ : constant Entity_Id := Base_Type (Typ);
5273 -- Verify that the character does belong to the type of the context
5275 Set_Etype (N, B_Typ);
5276 Eval_Character_Literal (N);
5278 -- Wide_Wide_Character literals must always be defined, since the set
5279 -- of wide wide character literals is complete, i.e. if a character
5280 -- literal is accepted by the parser, then it is OK for wide wide
5281 -- character (out of range character literals are rejected).
5283 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5286 -- Always accept character literal for type Any_Character, which
5287 -- occurs in error situations and in comparisons of literals, both
5288 -- of which should accept all literals.
5290 elsif B_Typ = Any_Character then
5293 -- For Standard.Character or a type derived from it, check that
5294 -- the literal is in range
5296 elsif Root_Type (B_Typ) = Standard_Character then
5297 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5301 -- For Standard.Wide_Character or a type derived from it, check
5302 -- that the literal is in range
5304 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5305 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5309 -- For Standard.Wide_Wide_Character or a type derived from it, we
5310 -- know the literal is in range, since the parser checked!
5312 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5315 -- If the entity is already set, this has already been resolved in
5316 -- a generic context, or comes from expansion. Nothing else to do.
5318 elsif Present (Entity (N)) then
5321 -- Otherwise we have a user defined character type, and we can use
5322 -- the standard visibility mechanisms to locate the referenced entity
5325 C := Current_Entity (N);
5326 while Present (C) loop
5327 if Etype (C) = B_Typ then
5328 Set_Entity_With_Style_Check (N, C);
5329 Generate_Reference (C, N);
5337 -- If we fall through, then the literal does not match any of the
5338 -- entries of the enumeration type. This isn't just a constraint
5339 -- error situation, it is an illegality (see RM 4.2).
5342 ("character not defined for }", N, First_Subtype (B_Typ));
5343 end Resolve_Character_Literal;
5345 ---------------------------
5346 -- Resolve_Comparison_Op --
5347 ---------------------------
5349 -- Context requires a boolean type, and plays no role in resolution.
5350 -- Processing identical to that for equality operators. The result
5351 -- type is the base type, which matters when pathological subtypes of
5352 -- booleans with limited ranges are used.
5354 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5355 L : constant Node_Id := Left_Opnd (N);
5356 R : constant Node_Id := Right_Opnd (N);
5360 -- If this is an intrinsic operation which is not predefined, use
5361 -- the types of its declared arguments to resolve the possibly
5362 -- overloaded operands. Otherwise the operands are unambiguous and
5363 -- specify the expected type.
5365 if Scope (Entity (N)) /= Standard_Standard then
5366 T := Etype (First_Entity (Entity (N)));
5369 T := Find_Unique_Type (L, R);
5371 if T = Any_Fixed then
5372 T := Unique_Fixed_Point_Type (L);
5376 Set_Etype (N, Base_Type (Typ));
5377 Generate_Reference (T, N, ' ');
5379 if T /= Any_Type then
5381 or else T = Any_Composite
5382 or else T = Any_Character
5384 if T = Any_Character then
5385 Ambiguous_Character (L);
5387 Error_Msg_N ("ambiguous operands for comparison", N);
5390 Set_Etype (N, Any_Type);
5396 Check_Unset_Reference (L);
5397 Check_Unset_Reference (R);
5398 Generate_Operator_Reference (N, T);
5399 Check_Low_Bound_Tested (N);
5400 Eval_Relational_Op (N);
5403 end Resolve_Comparison_Op;
5405 ------------------------------------
5406 -- Resolve_Conditional_Expression --
5407 ------------------------------------
5409 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5410 Condition : constant Node_Id := First (Expressions (N));
5411 Then_Expr : constant Node_Id := Next (Condition);
5412 Else_Expr : constant Node_Id := Next (Then_Expr);
5415 Resolve (Condition, Standard_Boolean);
5416 Resolve (Then_Expr, Typ);
5417 Resolve (Else_Expr, Typ);
5420 Eval_Conditional_Expression (N);
5421 end Resolve_Conditional_Expression;
5423 -----------------------------------------
5424 -- Resolve_Discrete_Subtype_Indication --
5425 -----------------------------------------
5427 procedure Resolve_Discrete_Subtype_Indication
5435 Analyze (Subtype_Mark (N));
5436 S := Entity (Subtype_Mark (N));
5438 if Nkind (Constraint (N)) /= N_Range_Constraint then
5439 Error_Msg_N ("expect range constraint for discrete type", N);
5440 Set_Etype (N, Any_Type);
5443 R := Range_Expression (Constraint (N));
5451 if Base_Type (S) /= Base_Type (Typ) then
5453 ("expect subtype of }", N, First_Subtype (Typ));
5455 -- Rewrite the constraint as a range of Typ
5456 -- to allow compilation to proceed further.
5459 Rewrite (Low_Bound (R),
5460 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5461 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5462 Attribute_Name => Name_First));
5463 Rewrite (High_Bound (R),
5464 Make_Attribute_Reference (Sloc (High_Bound (R)),
5465 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5466 Attribute_Name => Name_First));
5470 Set_Etype (N, Etype (R));
5472 -- Additionally, we must check that the bounds are compatible
5473 -- with the given subtype, which might be different from the
5474 -- type of the context.
5476 Apply_Range_Check (R, S);
5478 -- ??? If the above check statically detects a Constraint_Error
5479 -- it replaces the offending bound(s) of the range R with a
5480 -- Constraint_Error node. When the itype which uses these bounds
5481 -- is frozen the resulting call to Duplicate_Subexpr generates
5482 -- a new temporary for the bounds.
5484 -- Unfortunately there are other itypes that are also made depend
5485 -- on these bounds, so when Duplicate_Subexpr is called they get
5486 -- a forward reference to the newly created temporaries and Gigi
5487 -- aborts on such forward references. This is probably sign of a
5488 -- more fundamental problem somewhere else in either the order of
5489 -- itype freezing or the way certain itypes are constructed.
5491 -- To get around this problem we call Remove_Side_Effects right
5492 -- away if either bounds of R are a Constraint_Error.
5495 L : constant Node_Id := Low_Bound (R);
5496 H : constant Node_Id := High_Bound (R);
5499 if Nkind (L) = N_Raise_Constraint_Error then
5500 Remove_Side_Effects (L);
5503 if Nkind (H) = N_Raise_Constraint_Error then
5504 Remove_Side_Effects (H);
5508 Check_Unset_Reference (Low_Bound (R));
5509 Check_Unset_Reference (High_Bound (R));
5512 end Resolve_Discrete_Subtype_Indication;
5514 -------------------------
5515 -- Resolve_Entity_Name --
5516 -------------------------
5518 -- Used to resolve identifiers and expanded names
5520 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5521 E : constant Entity_Id := Entity (N);
5524 -- If garbage from errors, set to Any_Type and return
5526 if No (E) and then Total_Errors_Detected /= 0 then
5527 Set_Etype (N, Any_Type);
5531 -- Replace named numbers by corresponding literals. Note that this is
5532 -- the one case where Resolve_Entity_Name must reset the Etype, since
5533 -- it is currently marked as universal.
5535 if Ekind (E) = E_Named_Integer then
5537 Eval_Named_Integer (N);
5539 elsif Ekind (E) = E_Named_Real then
5541 Eval_Named_Real (N);
5543 -- Allow use of subtype only if it is a concurrent type where we are
5544 -- currently inside the body. This will eventually be expanded
5545 -- into a call to Self (for tasks) or _object (for protected
5546 -- objects). Any other use of a subtype is invalid.
5548 elsif Is_Type (E) then
5549 if Is_Concurrent_Type (E)
5550 and then In_Open_Scopes (E)
5555 ("invalid use of subtype mark in expression or call", N);
5558 -- Check discriminant use if entity is discriminant in current scope,
5559 -- i.e. discriminant of record or concurrent type currently being
5560 -- analyzed. Uses in corresponding body are unrestricted.
5562 elsif Ekind (E) = E_Discriminant
5563 and then Scope (E) = Current_Scope
5564 and then not Has_Completion (Current_Scope)
5566 Check_Discriminant_Use (N);
5568 -- A parameterless generic function cannot appear in a context that
5569 -- requires resolution.
5571 elsif Ekind (E) = E_Generic_Function then
5572 Error_Msg_N ("illegal use of generic function", N);
5574 elsif Ekind (E) = E_Out_Parameter
5575 and then Ada_Version = Ada_83
5576 and then (Nkind (Parent (N)) in N_Op
5577 or else (Nkind (Parent (N)) = N_Assignment_Statement
5578 and then N = Expression (Parent (N)))
5579 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5581 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5583 -- In all other cases, just do the possible static evaluation
5586 -- A deferred constant that appears in an expression must have
5587 -- a completion, unless it has been removed by in-place expansion
5590 if Ekind (E) = E_Constant
5591 and then Comes_From_Source (E)
5592 and then No (Constant_Value (E))
5593 and then Is_Frozen (Etype (E))
5594 and then not In_Spec_Expression
5595 and then not Is_Imported (E)
5598 if No_Initialization (Parent (E))
5599 or else (Present (Full_View (E))
5600 and then No_Initialization (Parent (Full_View (E))))
5605 "deferred constant is frozen before completion", N);
5609 Eval_Entity_Name (N);
5611 end Resolve_Entity_Name;
5617 procedure Resolve_Entry (Entry_Name : Node_Id) is
5618 Loc : constant Source_Ptr := Sloc (Entry_Name);
5626 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5627 -- If the bounds of the entry family being called depend on task
5628 -- discriminants, build a new index subtype where a discriminant is
5629 -- replaced with the value of the discriminant of the target task.
5630 -- The target task is the prefix of the entry name in the call.
5632 -----------------------
5633 -- Actual_Index_Type --
5634 -----------------------
5636 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5637 Typ : constant Entity_Id := Entry_Index_Type (E);
5638 Tsk : constant Entity_Id := Scope (E);
5639 Lo : constant Node_Id := Type_Low_Bound (Typ);
5640 Hi : constant Node_Id := Type_High_Bound (Typ);
5643 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5644 -- If the bound is given by a discriminant, replace with a reference
5645 -- to the discriminant of the same name in the target task.
5646 -- If the entry name is the target of a requeue statement and the
5647 -- entry is in the current protected object, the bound to be used
5648 -- is the discriminal of the object (see apply_range_checks for
5649 -- details of the transformation).
5651 -----------------------------
5652 -- Actual_Discriminant_Ref --
5653 -----------------------------
5655 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5656 Typ : constant Entity_Id := Etype (Bound);
5660 Remove_Side_Effects (Bound);
5662 if not Is_Entity_Name (Bound)
5663 or else Ekind (Entity (Bound)) /= E_Discriminant
5667 elsif Is_Protected_Type (Tsk)
5668 and then In_Open_Scopes (Tsk)
5669 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5671 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5675 Make_Selected_Component (Loc,
5676 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5677 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5682 end Actual_Discriminant_Ref;
5684 -- Start of processing for Actual_Index_Type
5687 if not Has_Discriminants (Tsk)
5688 or else (not Is_Entity_Name (Lo)
5689 and then not Is_Entity_Name (Hi))
5691 return Entry_Index_Type (E);
5694 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5695 Set_Etype (New_T, Base_Type (Typ));
5696 Set_Size_Info (New_T, Typ);
5697 Set_RM_Size (New_T, RM_Size (Typ));
5698 Set_Scalar_Range (New_T,
5699 Make_Range (Sloc (Entry_Name),
5700 Low_Bound => Actual_Discriminant_Ref (Lo),
5701 High_Bound => Actual_Discriminant_Ref (Hi)));
5705 end Actual_Index_Type;
5707 -- Start of processing of Resolve_Entry
5710 -- Find name of entry being called, and resolve prefix of name
5711 -- with its own type. The prefix can be overloaded, and the name
5712 -- and signature of the entry must be taken into account.
5714 if Nkind (Entry_Name) = N_Indexed_Component then
5716 -- Case of dealing with entry family within the current tasks
5718 E_Name := Prefix (Entry_Name);
5721 E_Name := Entry_Name;
5724 if Is_Entity_Name (E_Name) then
5725 -- Entry call to an entry (or entry family) in the current task.
5726 -- This is legal even though the task will deadlock. Rewrite as
5727 -- call to current task.
5729 -- This can also be a call to an entry in an enclosing task.
5730 -- If this is a single task, we have to retrieve its name,
5731 -- because the scope of the entry is the task type, not the
5732 -- object. If the enclosing task is a task type, the identity
5733 -- of the task is given by its own self variable.
5735 -- Finally this can be a requeue on an entry of the same task
5736 -- or protected object.
5738 S := Scope (Entity (E_Name));
5740 for J in reverse 0 .. Scope_Stack.Last loop
5742 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5743 and then not Comes_From_Source (S)
5745 -- S is an enclosing task or protected object. The concurrent
5746 -- declaration has been converted into a type declaration, and
5747 -- the object itself has an object declaration that follows
5748 -- the type in the same declarative part.
5750 Tsk := Next_Entity (S);
5751 while Etype (Tsk) /= S loop
5758 elsif S = Scope_Stack.Table (J).Entity then
5760 -- Call to current task. Will be transformed into call to Self
5768 Make_Selected_Component (Loc,
5769 Prefix => New_Occurrence_Of (S, Loc),
5771 New_Occurrence_Of (Entity (E_Name), Loc));
5772 Rewrite (E_Name, New_N);
5775 elsif Nkind (Entry_Name) = N_Selected_Component
5776 and then Is_Overloaded (Prefix (Entry_Name))
5778 -- Use the entry name (which must be unique at this point) to
5779 -- find the prefix that returns the corresponding task type or
5783 Pref : constant Node_Id := Prefix (Entry_Name);
5784 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5789 Get_First_Interp (Pref, I, It);
5790 while Present (It.Typ) loop
5791 if Scope (Ent) = It.Typ then
5792 Set_Etype (Pref, It.Typ);
5796 Get_Next_Interp (I, It);
5801 if Nkind (Entry_Name) = N_Selected_Component then
5802 Resolve (Prefix (Entry_Name));
5804 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5805 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5806 Resolve (Prefix (Prefix (Entry_Name)));
5807 Index := First (Expressions (Entry_Name));
5808 Resolve (Index, Entry_Index_Type (Nam));
5810 -- Up to this point the expression could have been the actual
5811 -- in a simple entry call, and be given by a named association.
5813 if Nkind (Index) = N_Parameter_Association then
5814 Error_Msg_N ("expect expression for entry index", Index);
5816 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5821 ------------------------
5822 -- Resolve_Entry_Call --
5823 ------------------------
5825 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5826 Entry_Name : constant Node_Id := Name (N);
5827 Loc : constant Source_Ptr := Sloc (Entry_Name);
5829 First_Named : Node_Id;
5836 -- We kill all checks here, because it does not seem worth the
5837 -- effort to do anything better, an entry call is a big operation.
5841 -- Processing of the name is similar for entry calls and protected
5842 -- operation calls. Once the entity is determined, we can complete
5843 -- the resolution of the actuals.
5845 -- The selector may be overloaded, in the case of a protected object
5846 -- with overloaded functions. The type of the context is used for
5849 if Nkind (Entry_Name) = N_Selected_Component
5850 and then Is_Overloaded (Selector_Name (Entry_Name))
5851 and then Typ /= Standard_Void_Type
5858 Get_First_Interp (Selector_Name (Entry_Name), I, It);
5859 while Present (It.Typ) loop
5860 if Covers (Typ, It.Typ) then
5861 Set_Entity (Selector_Name (Entry_Name), It.Nam);
5862 Set_Etype (Entry_Name, It.Typ);
5864 Generate_Reference (It.Typ, N, ' ');
5867 Get_Next_Interp (I, It);
5872 Resolve_Entry (Entry_Name);
5874 if Nkind (Entry_Name) = N_Selected_Component then
5876 -- Simple entry call
5878 Nam := Entity (Selector_Name (Entry_Name));
5879 Obj := Prefix (Entry_Name);
5880 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
5882 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5884 -- Call to member of entry family
5886 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5887 Obj := Prefix (Prefix (Entry_Name));
5888 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
5891 -- We cannot in general check the maximum depth of protected entry
5892 -- calls at compile time. But we can tell that any protected entry
5893 -- call at all violates a specified nesting depth of zero.
5895 if Is_Protected_Type (Scope (Nam)) then
5896 Check_Restriction (Max_Entry_Queue_Length, N);
5899 -- Use context type to disambiguate a protected function that can be
5900 -- called without actuals and that returns an array type, and where
5901 -- the argument list may be an indexing of the returned value.
5903 if Ekind (Nam) = E_Function
5904 and then Needs_No_Actuals (Nam)
5905 and then Present (Parameter_Associations (N))
5907 ((Is_Array_Type (Etype (Nam))
5908 and then Covers (Typ, Component_Type (Etype (Nam))))
5910 or else (Is_Access_Type (Etype (Nam))
5911 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5912 and then Covers (Typ,
5913 Component_Type (Designated_Type (Etype (Nam))))))
5916 Index_Node : Node_Id;
5920 Make_Indexed_Component (Loc,
5922 Make_Function_Call (Loc,
5923 Name => Relocate_Node (Entry_Name)),
5924 Expressions => Parameter_Associations (N));
5926 -- Since we are correcting a node classification error made by
5927 -- the parser, we call Replace rather than Rewrite.
5929 Replace (N, Index_Node);
5930 Set_Etype (Prefix (N), Etype (Nam));
5932 Resolve_Indexed_Component (N, Typ);
5937 -- The operation name may have been overloaded. Order the actuals
5938 -- according to the formals of the resolved entity, and set the
5939 -- return type to that of the operation.
5942 Normalize_Actuals (N, Nam, False, Norm_OK);
5943 pragma Assert (Norm_OK);
5944 Set_Etype (N, Etype (Nam));
5947 Resolve_Actuals (N, Nam);
5948 Generate_Reference (Nam, Entry_Name);
5950 if Ekind (Nam) = E_Entry
5951 or else Ekind (Nam) = E_Entry_Family
5953 Check_Potentially_Blocking_Operation (N);
5956 -- Verify that a procedure call cannot masquerade as an entry
5957 -- call where an entry call is expected.
5959 if Ekind (Nam) = E_Procedure then
5960 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5961 and then N = Entry_Call_Statement (Parent (N))
5963 Error_Msg_N ("entry call required in select statement", N);
5965 elsif Nkind (Parent (N)) = N_Triggering_Alternative
5966 and then N = Triggering_Statement (Parent (N))
5968 Error_Msg_N ("triggering statement cannot be procedure call", N);
5970 elsif Ekind (Scope (Nam)) = E_Task_Type
5971 and then not In_Open_Scopes (Scope (Nam))
5973 Error_Msg_N ("task has no entry with this name", Entry_Name);
5977 -- After resolution, entry calls and protected procedure calls
5978 -- are changed into entry calls, for expansion. The structure
5979 -- of the node does not change, so it can safely be done in place.
5980 -- Protected function calls must keep their structure because they
5981 -- are subexpressions.
5983 if Ekind (Nam) /= E_Function then
5985 -- A protected operation that is not a function may modify the
5986 -- corresponding object, and cannot apply to a constant.
5987 -- If this is an internal call, the prefix is the type itself.
5989 if Is_Protected_Type (Scope (Nam))
5990 and then not Is_Variable (Obj)
5991 and then (not Is_Entity_Name (Obj)
5992 or else not Is_Type (Entity (Obj)))
5995 ("prefix of protected procedure or entry call must be variable",
5999 Actuals := Parameter_Associations (N);
6000 First_Named := First_Named_Actual (N);
6003 Make_Entry_Call_Statement (Loc,
6005 Parameter_Associations => Actuals));
6007 Set_First_Named_Actual (N, First_Named);
6008 Set_Analyzed (N, True);
6010 -- Protected functions can return on the secondary stack, in which
6011 -- case we must trigger the transient scope mechanism.
6013 elsif Expander_Active
6014 and then Requires_Transient_Scope (Etype (Nam))
6016 Establish_Transient_Scope (N, Sec_Stack => True);
6018 end Resolve_Entry_Call;
6020 -------------------------
6021 -- Resolve_Equality_Op --
6022 -------------------------
6024 -- Both arguments must have the same type, and the boolean context
6025 -- does not participate in the resolution. The first pass verifies
6026 -- that the interpretation is not ambiguous, and the type of the left
6027 -- argument is correctly set, or is Any_Type in case of ambiguity.
6028 -- If both arguments are strings or aggregates, allocators, or Null,
6029 -- they are ambiguous even though they carry a single (universal) type.
6030 -- Diagnose this case here.
6032 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6033 L : constant Node_Id := Left_Opnd (N);
6034 R : constant Node_Id := Right_Opnd (N);
6035 T : Entity_Id := Find_Unique_Type (L, R);
6037 function Find_Unique_Access_Type return Entity_Id;
6038 -- In the case of allocators, make a last-ditch attempt to find a single
6039 -- access type with the right designated type. This is semantically
6040 -- dubious, and of no interest to any real code, but c48008a makes it
6043 -----------------------------
6044 -- Find_Unique_Access_Type --
6045 -----------------------------
6047 function Find_Unique_Access_Type return Entity_Id is
6053 if Ekind (Etype (R)) = E_Allocator_Type then
6054 Acc := Designated_Type (Etype (R));
6055 elsif Ekind (Etype (L)) = E_Allocator_Type then
6056 Acc := Designated_Type (Etype (L));
6062 while S /= Standard_Standard loop
6063 E := First_Entity (S);
6064 while Present (E) loop
6066 and then Is_Access_Type (E)
6067 and then Ekind (E) /= E_Allocator_Type
6068 and then Designated_Type (E) = Base_Type (Acc)
6080 end Find_Unique_Access_Type;
6082 -- Start of processing for Resolve_Equality_Op
6085 Set_Etype (N, Base_Type (Typ));
6086 Generate_Reference (T, N, ' ');
6088 if T = Any_Fixed then
6089 T := Unique_Fixed_Point_Type (L);
6092 if T /= Any_Type then
6094 or else T = Any_Composite
6095 or else T = Any_Character
6097 if T = Any_Character then
6098 Ambiguous_Character (L);
6100 Error_Msg_N ("ambiguous operands for equality", N);
6103 Set_Etype (N, Any_Type);
6106 elsif T = Any_Access
6107 or else Ekind (T) = E_Allocator_Type
6108 or else Ekind (T) = E_Access_Attribute_Type
6110 T := Find_Unique_Access_Type;
6113 Error_Msg_N ("ambiguous operands for equality", N);
6114 Set_Etype (N, Any_Type);
6122 -- If the unique type is a class-wide type then it will be expanded
6123 -- into a dispatching call to the predefined primitive. Therefore we
6124 -- check here for potential violation of such restriction.
6126 if Is_Class_Wide_Type (T) then
6127 Check_Restriction (No_Dispatching_Calls, N);
6130 if Warn_On_Redundant_Constructs
6131 and then Comes_From_Source (N)
6132 and then Is_Entity_Name (R)
6133 and then Entity (R) = Standard_True
6134 and then Comes_From_Source (R)
6136 Error_Msg_N ("?comparison with True is redundant!", R);
6139 Check_Unset_Reference (L);
6140 Check_Unset_Reference (R);
6141 Generate_Operator_Reference (N, T);
6142 Check_Low_Bound_Tested (N);
6144 -- If this is an inequality, it may be the implicit inequality
6145 -- created for a user-defined operation, in which case the corres-
6146 -- ponding equality operation is not intrinsic, and the operation
6147 -- cannot be constant-folded. Else fold.
6149 if Nkind (N) = N_Op_Eq
6150 or else Comes_From_Source (Entity (N))
6151 or else Ekind (Entity (N)) = E_Operator
6152 or else Is_Intrinsic_Subprogram
6153 (Corresponding_Equality (Entity (N)))
6155 Eval_Relational_Op (N);
6157 elsif Nkind (N) = N_Op_Ne
6158 and then Is_Abstract_Subprogram (Entity (N))
6160 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6163 -- Ada 2005: If one operand is an anonymous access type, convert
6164 -- the other operand to it, to ensure that the underlying types
6165 -- match in the back-end. Same for access_to_subprogram, and the
6166 -- conversion verifies that the types are subtype conformant.
6168 -- We apply the same conversion in the case one of the operands is
6169 -- a private subtype of the type of the other.
6171 -- Why the Expander_Active test here ???
6175 (Ekind (T) = E_Anonymous_Access_Type
6176 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6177 or else Is_Private_Type (T))
6179 if Etype (L) /= T then
6181 Make_Unchecked_Type_Conversion (Sloc (L),
6182 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6183 Expression => Relocate_Node (L)));
6184 Analyze_And_Resolve (L, T);
6187 if (Etype (R)) /= T then
6189 Make_Unchecked_Type_Conversion (Sloc (R),
6190 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6191 Expression => Relocate_Node (R)));
6192 Analyze_And_Resolve (R, T);
6196 end Resolve_Equality_Op;
6198 ----------------------------------
6199 -- Resolve_Explicit_Dereference --
6200 ----------------------------------
6202 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6203 Loc : constant Source_Ptr := Sloc (N);
6205 P : constant Node_Id := Prefix (N);
6210 Check_Fully_Declared_Prefix (Typ, P);
6212 if Is_Overloaded (P) then
6214 -- Use the context type to select the prefix that has the correct
6217 Get_First_Interp (P, I, It);
6218 while Present (It.Typ) loop
6219 exit when Is_Access_Type (It.Typ)
6220 and then Covers (Typ, Designated_Type (It.Typ));
6221 Get_Next_Interp (I, It);
6224 if Present (It.Typ) then
6225 Resolve (P, It.Typ);
6227 -- If no interpretation covers the designated type of the prefix,
6228 -- this is the pathological case where not all implementations of
6229 -- the prefix allow the interpretation of the node as a call. Now
6230 -- that the expected type is known, Remove other interpretations
6231 -- from prefix, rewrite it as a call, and resolve again, so that
6232 -- the proper call node is generated.
6234 Get_First_Interp (P, I, It);
6235 while Present (It.Typ) loop
6236 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6240 Get_Next_Interp (I, It);
6244 Make_Function_Call (Loc,
6246 Make_Explicit_Dereference (Loc,
6248 Parameter_Associations => New_List);
6250 Save_Interps (N, New_N);
6252 Analyze_And_Resolve (N, Typ);
6256 Set_Etype (N, Designated_Type (It.Typ));
6262 if Is_Access_Type (Etype (P)) then
6263 Apply_Access_Check (N);
6266 -- If the designated type is a packed unconstrained array type, and the
6267 -- explicit dereference is not in the context of an attribute reference,
6268 -- then we must compute and set the actual subtype, since it is needed
6269 -- by Gigi. The reason we exclude the attribute case is that this is
6270 -- handled fine by Gigi, and in fact we use such attributes to build the
6271 -- actual subtype. We also exclude generated code (which builds actual
6272 -- subtypes directly if they are needed).
6274 if Is_Array_Type (Etype (N))
6275 and then Is_Packed (Etype (N))
6276 and then not Is_Constrained (Etype (N))
6277 and then Nkind (Parent (N)) /= N_Attribute_Reference
6278 and then Comes_From_Source (N)
6280 Set_Etype (N, Get_Actual_Subtype (N));
6283 -- Note: there is no Eval processing required for an explicit deference,
6284 -- because the type is known to be an allocators, and allocator
6285 -- expressions can never be static.
6287 end Resolve_Explicit_Dereference;
6289 -------------------------------
6290 -- Resolve_Indexed_Component --
6291 -------------------------------
6293 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6294 Name : constant Node_Id := Prefix (N);
6296 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6300 if Is_Overloaded (Name) then
6302 -- Use the context type to select the prefix that yields the correct
6308 I1 : Interp_Index := 0;
6309 P : constant Node_Id := Prefix (N);
6310 Found : Boolean := False;
6313 Get_First_Interp (P, I, It);
6314 while Present (It.Typ) loop
6315 if (Is_Array_Type (It.Typ)
6316 and then Covers (Typ, Component_Type (It.Typ)))
6317 or else (Is_Access_Type (It.Typ)
6318 and then Is_Array_Type (Designated_Type (It.Typ))
6320 (Typ, Component_Type (Designated_Type (It.Typ))))
6323 It := Disambiguate (P, I1, I, Any_Type);
6325 if It = No_Interp then
6326 Error_Msg_N ("ambiguous prefix for indexing", N);
6332 Array_Type := It.Typ;
6338 Array_Type := It.Typ;
6343 Get_Next_Interp (I, It);
6348 Array_Type := Etype (Name);
6351 Resolve (Name, Array_Type);
6352 Array_Type := Get_Actual_Subtype_If_Available (Name);
6354 -- If prefix is access type, dereference to get real array type.
6355 -- Note: we do not apply an access check because the expander always
6356 -- introduces an explicit dereference, and the check will happen there.
6358 if Is_Access_Type (Array_Type) then
6359 Array_Type := Designated_Type (Array_Type);
6362 -- If name was overloaded, set component type correctly now
6363 -- If a misplaced call to an entry family (which has no index types)
6364 -- return. Error will be diagnosed from calling context.
6366 if Is_Array_Type (Array_Type) then
6367 Set_Etype (N, Component_Type (Array_Type));
6372 Index := First_Index (Array_Type);
6373 Expr := First (Expressions (N));
6375 -- The prefix may have resolved to a string literal, in which case its
6376 -- etype has a special representation. This is only possible currently
6377 -- if the prefix is a static concatenation, written in functional
6380 if Ekind (Array_Type) = E_String_Literal_Subtype then
6381 Resolve (Expr, Standard_Positive);
6384 while Present (Index) and Present (Expr) loop
6385 Resolve (Expr, Etype (Index));
6386 Check_Unset_Reference (Expr);
6388 if Is_Scalar_Type (Etype (Expr)) then
6389 Apply_Scalar_Range_Check (Expr, Etype (Index));
6391 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6399 -- Do not generate the warning on suspicious index if we are analyzing
6400 -- package Ada.Tags; otherwise we will report the warning with the
6401 -- Prims_Ptr field of the dispatch table.
6403 if Scope (Etype (Prefix (N))) = Standard_Standard
6405 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6408 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6409 Eval_Indexed_Component (N);
6411 end Resolve_Indexed_Component;
6413 -----------------------------
6414 -- Resolve_Integer_Literal --
6415 -----------------------------
6417 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6420 Eval_Integer_Literal (N);
6421 end Resolve_Integer_Literal;
6423 --------------------------------
6424 -- Resolve_Intrinsic_Operator --
6425 --------------------------------
6427 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6428 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6435 while Scope (Op) /= Standard_Standard loop
6437 pragma Assert (Present (Op));
6441 Set_Is_Overloaded (N, False);
6443 -- If the operand type is private, rewrite with suitable conversions on
6444 -- the operands and the result, to expose the proper underlying numeric
6447 if Is_Private_Type (Typ) then
6448 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6450 if Nkind (N) = N_Op_Expon then
6451 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6453 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6456 Save_Interps (Left_Opnd (N), Expression (Arg1));
6457 Save_Interps (Right_Opnd (N), Expression (Arg2));
6459 Set_Left_Opnd (N, Arg1);
6460 Set_Right_Opnd (N, Arg2);
6462 Set_Etype (N, Btyp);
6463 Rewrite (N, Unchecked_Convert_To (Typ, N));
6466 elsif Typ /= Etype (Left_Opnd (N))
6467 or else Typ /= Etype (Right_Opnd (N))
6469 -- Add explicit conversion where needed, and save interpretations
6470 -- in case operands are overloaded.
6472 Arg1 := Convert_To (Typ, Left_Opnd (N));
6473 Arg2 := Convert_To (Typ, Right_Opnd (N));
6475 if Nkind (Arg1) = N_Type_Conversion then
6476 Save_Interps (Left_Opnd (N), Expression (Arg1));
6478 Save_Interps (Left_Opnd (N), Arg1);
6481 if Nkind (Arg2) = N_Type_Conversion then
6482 Save_Interps (Right_Opnd (N), Expression (Arg2));
6484 Save_Interps (Right_Opnd (N), Arg2);
6487 Rewrite (Left_Opnd (N), Arg1);
6488 Rewrite (Right_Opnd (N), Arg2);
6491 Resolve_Arithmetic_Op (N, Typ);
6494 Resolve_Arithmetic_Op (N, Typ);
6496 end Resolve_Intrinsic_Operator;
6498 --------------------------------------
6499 -- Resolve_Intrinsic_Unary_Operator --
6500 --------------------------------------
6502 procedure Resolve_Intrinsic_Unary_Operator
6506 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6512 while Scope (Op) /= Standard_Standard loop
6514 pragma Assert (Present (Op));
6519 if Is_Private_Type (Typ) then
6520 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6521 Save_Interps (Right_Opnd (N), Expression (Arg2));
6523 Set_Right_Opnd (N, Arg2);
6525 Set_Etype (N, Btyp);
6526 Rewrite (N, Unchecked_Convert_To (Typ, N));
6530 Resolve_Unary_Op (N, Typ);
6532 end Resolve_Intrinsic_Unary_Operator;
6534 ------------------------
6535 -- Resolve_Logical_Op --
6536 ------------------------
6538 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6540 N_Opr : constant Node_Kind := Nkind (N);
6543 -- Predefined operations on scalar types yield the base type. On the
6544 -- other hand, logical operations on arrays yield the type of the
6545 -- arguments (and the context).
6547 if Is_Array_Type (Typ) then
6550 B_Typ := Base_Type (Typ);
6553 -- The following test is required because the operands of the operation
6554 -- may be literals, in which case the resulting type appears to be
6555 -- compatible with a signed integer type, when in fact it is compatible
6556 -- only with modular types. If the context itself is universal, the
6557 -- operation is illegal.
6559 if not Valid_Boolean_Arg (Typ) then
6560 Error_Msg_N ("invalid context for logical operation", N);
6561 Set_Etype (N, Any_Type);
6564 elsif Typ = Any_Modular then
6566 ("no modular type available in this context", N);
6567 Set_Etype (N, Any_Type);
6569 elsif Is_Modular_Integer_Type (Typ)
6570 and then Etype (Left_Opnd (N)) = Universal_Integer
6571 and then Etype (Right_Opnd (N)) = Universal_Integer
6573 Check_For_Visible_Operator (N, B_Typ);
6576 Resolve (Left_Opnd (N), B_Typ);
6577 Resolve (Right_Opnd (N), B_Typ);
6579 Check_Unset_Reference (Left_Opnd (N));
6580 Check_Unset_Reference (Right_Opnd (N));
6582 Set_Etype (N, B_Typ);
6583 Generate_Operator_Reference (N, B_Typ);
6584 Eval_Logical_Op (N);
6586 -- Check for violation of restriction No_Direct_Boolean_Operators
6587 -- if the operator was not eliminated by the Eval_Logical_Op call.
6589 if Nkind (N) = N_Opr
6590 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
6592 Check_Restriction (No_Direct_Boolean_Operators, N);
6594 end Resolve_Logical_Op;
6596 ---------------------------
6597 -- Resolve_Membership_Op --
6598 ---------------------------
6600 -- The context can only be a boolean type, and does not determine
6601 -- the arguments. Arguments should be unambiguous, but the preference
6602 -- rule for universal types applies.
6604 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6605 pragma Warnings (Off, Typ);
6607 L : constant Node_Id := Left_Opnd (N);
6608 R : constant Node_Id := Right_Opnd (N);
6612 if L = Error or else R = Error then
6616 if not Is_Overloaded (R)
6618 (Etype (R) = Universal_Integer or else
6619 Etype (R) = Universal_Real)
6620 and then Is_Overloaded (L)
6624 -- Ada 2005 (AI-251): Give support to the following case:
6626 -- type I is interface;
6627 -- type T is tagged ...
6629 -- function Test (O : I'Class) is
6631 -- return O in T'Class.
6634 -- In this case we have nothing else to do; the membership test will be
6635 -- done at run-time.
6637 elsif Ada_Version >= Ada_05
6638 and then Is_Class_Wide_Type (Etype (L))
6639 and then Is_Interface (Etype (L))
6640 and then Is_Class_Wide_Type (Etype (R))
6641 and then not Is_Interface (Etype (R))
6646 T := Intersect_Types (L, R);
6650 Check_Unset_Reference (L);
6652 if Nkind (R) = N_Range
6653 and then not Is_Scalar_Type (T)
6655 Error_Msg_N ("scalar type required for range", R);
6658 if Is_Entity_Name (R) then
6659 Freeze_Expression (R);
6662 Check_Unset_Reference (R);
6665 Eval_Membership_Op (N);
6666 end Resolve_Membership_Op;
6672 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6673 Loc : constant Source_Ptr := Sloc (N);
6676 -- Handle restriction against anonymous null access values This
6677 -- restriction can be turned off using -gnatdj.
6679 -- Ada 2005 (AI-231): Remove restriction
6681 if Ada_Version < Ada_05
6682 and then not Debug_Flag_J
6683 and then Ekind (Typ) = E_Anonymous_Access_Type
6684 and then Comes_From_Source (N)
6686 -- In the common case of a call which uses an explicitly null
6687 -- value for an access parameter, give specialized error message.
6689 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6693 ("null is not allowed as argument for an access parameter", N);
6695 -- Standard message for all other cases (are there any?)
6699 ("null cannot be of an anonymous access type", N);
6703 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6704 -- assignment to a null-excluding object
6706 if Ada_Version >= Ada_05
6707 and then Can_Never_Be_Null (Typ)
6708 and then Nkind (Parent (N)) = N_Assignment_Statement
6710 if not Inside_Init_Proc then
6712 (Compile_Time_Constraint_Error (N,
6713 "(Ada 2005) null not allowed in null-excluding objects?"),
6714 Make_Raise_Constraint_Error (Loc,
6715 Reason => CE_Access_Check_Failed));
6718 Make_Raise_Constraint_Error (Loc,
6719 Reason => CE_Access_Check_Failed));
6723 -- In a distributed context, null for a remote access to subprogram
6724 -- may need to be replaced with a special record aggregate. In this
6725 -- case, return after having done the transformation.
6727 if (Ekind (Typ) = E_Record_Type
6728 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6729 and then Remote_AST_Null_Value (N, Typ)
6734 -- The null literal takes its type from the context
6739 -----------------------
6740 -- Resolve_Op_Concat --
6741 -----------------------
6743 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6745 -- We wish to avoid deep recursion, because concatenations are often
6746 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6747 -- operands nonrecursively until we find something that is not a simple
6748 -- concatenation (A in this case). We resolve that, and then walk back
6749 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6750 -- to do the rest of the work at each level. The Parent pointers allow
6751 -- us to avoid recursion, and thus avoid running out of memory. See also
6752 -- Sem_Ch4.Analyze_Concatenation, where a similar hack is used.
6758 -- The following code is equivalent to:
6760 -- Resolve_Op_Concat_First (NN, Typ);
6761 -- Resolve_Op_Concat_Arg (N, ...);
6762 -- Resolve_Op_Concat_Rest (N, Typ);
6764 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6765 -- operand is a concatenation.
6767 -- Walk down left operands
6770 Resolve_Op_Concat_First (NN, Typ);
6771 Op1 := Left_Opnd (NN);
6772 exit when not (Nkind (Op1) = N_Op_Concat
6773 and then not Is_Array_Type (Component_Type (Typ))
6774 and then Entity (Op1) = Entity (NN));
6778 -- Now (given the above example) NN is A&B and Op1 is A
6780 -- First resolve Op1 ...
6782 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6784 -- ... then walk NN back up until we reach N (where we started), calling
6785 -- Resolve_Op_Concat_Rest along the way.
6788 Resolve_Op_Concat_Rest (NN, Typ);
6792 end Resolve_Op_Concat;
6794 ---------------------------
6795 -- Resolve_Op_Concat_Arg --
6796 ---------------------------
6798 procedure Resolve_Op_Concat_Arg
6804 Btyp : constant Entity_Id := Base_Type (Typ);
6809 or else (not Is_Overloaded (Arg)
6810 and then Etype (Arg) /= Any_Composite
6811 and then Covers (Component_Type (Typ), Etype (Arg)))
6813 Resolve (Arg, Component_Type (Typ));
6815 Resolve (Arg, Btyp);
6818 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6819 if Nkind (Arg) = N_Aggregate
6820 and then Is_Composite_Type (Component_Type (Typ))
6822 if Is_Private_Type (Component_Type (Typ)) then
6823 Resolve (Arg, Btyp);
6825 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6826 Set_Etype (Arg, Any_Type);
6830 if Is_Overloaded (Arg)
6831 and then Has_Compatible_Type (Arg, Typ)
6832 and then Etype (Arg) /= Any_Type
6840 Get_First_Interp (Arg, I, It);
6842 Get_Next_Interp (I, It);
6844 -- Special-case the error message when the overloading is
6845 -- caused by a function that yields an array and can be
6846 -- called without parameters.
6848 if It.Nam = Func then
6849 Error_Msg_Sloc := Sloc (Func);
6850 Error_Msg_N ("ambiguous call to function#", Arg);
6852 ("\\interpretation as call yields&", Arg, Typ);
6854 ("\\interpretation as indexing of call yields&",
6855 Arg, Component_Type (Typ));
6859 ("ambiguous operand for concatenation!", Arg);
6860 Get_First_Interp (Arg, I, It);
6861 while Present (It.Nam) loop
6862 Error_Msg_Sloc := Sloc (It.Nam);
6864 if Base_Type (It.Typ) = Base_Type (Typ)
6865 or else Base_Type (It.Typ) =
6866 Base_Type (Component_Type (Typ))
6868 Error_Msg_N ("\\possible interpretation#", Arg);
6871 Get_Next_Interp (I, It);
6877 Resolve (Arg, Component_Type (Typ));
6879 if Nkind (Arg) = N_String_Literal then
6880 Set_Etype (Arg, Component_Type (Typ));
6883 if Arg = Left_Opnd (N) then
6884 Set_Is_Component_Left_Opnd (N);
6886 Set_Is_Component_Right_Opnd (N);
6891 Resolve (Arg, Btyp);
6894 Check_Unset_Reference (Arg);
6895 end Resolve_Op_Concat_Arg;
6897 -----------------------------
6898 -- Resolve_Op_Concat_First --
6899 -----------------------------
6901 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
6902 Btyp : constant Entity_Id := Base_Type (Typ);
6903 Op1 : constant Node_Id := Left_Opnd (N);
6904 Op2 : constant Node_Id := Right_Opnd (N);
6907 -- The parser folds an enormous sequence of concatenations of string
6908 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
6909 -- in the right. If the expression resolves to a predefined "&"
6910 -- operator, all is well. Otherwise, the parser's folding is wrong, so
6911 -- we give an error. See P_Simple_Expression in Par.Ch4.
6913 if Nkind (Op2) = N_String_Literal
6914 and then Is_Folded_In_Parser (Op2)
6915 and then Ekind (Entity (N)) = E_Function
6917 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
6918 and then String_Length (Strval (Op1)) = 0);
6919 Error_Msg_N ("too many user-defined concatenations", N);
6923 Set_Etype (N, Btyp);
6925 if Is_Limited_Composite (Btyp) then
6926 Error_Msg_N ("concatenation not available for limited array", N);
6927 Explain_Limited_Type (Btyp, N);
6929 end Resolve_Op_Concat_First;
6931 ----------------------------
6932 -- Resolve_Op_Concat_Rest --
6933 ----------------------------
6935 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
6936 Op1 : constant Node_Id := Left_Opnd (N);
6937 Op2 : constant Node_Id := Right_Opnd (N);
6940 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
6942 Generate_Operator_Reference (N, Typ);
6944 if Is_String_Type (Typ) then
6945 Eval_Concatenation (N);
6948 -- If this is not a static concatenation, but the result is a
6949 -- string type (and not an array of strings) ensure that static
6950 -- string operands have their subtypes properly constructed.
6952 if Nkind (N) /= N_String_Literal
6953 and then Is_Character_Type (Component_Type (Typ))
6955 Set_String_Literal_Subtype (Op1, Typ);
6956 Set_String_Literal_Subtype (Op2, Typ);
6958 end Resolve_Op_Concat_Rest;
6960 ----------------------
6961 -- Resolve_Op_Expon --
6962 ----------------------
6964 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
6965 B_Typ : constant Entity_Id := Base_Type (Typ);
6968 -- Catch attempts to do fixed-point exponentiation with universal
6969 -- operands, which is a case where the illegality is not caught during
6970 -- normal operator analysis.
6972 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
6973 Error_Msg_N ("exponentiation not available for fixed point", N);
6977 if Comes_From_Source (N)
6978 and then Ekind (Entity (N)) = E_Function
6979 and then Is_Imported (Entity (N))
6980 and then Is_Intrinsic_Subprogram (Entity (N))
6982 Resolve_Intrinsic_Operator (N, Typ);
6986 if Etype (Left_Opnd (N)) = Universal_Integer
6987 or else Etype (Left_Opnd (N)) = Universal_Real
6989 Check_For_Visible_Operator (N, B_Typ);
6992 -- We do the resolution using the base type, because intermediate values
6993 -- in expressions always are of the base type, not a subtype of it.
6995 Resolve (Left_Opnd (N), B_Typ);
6996 Resolve (Right_Opnd (N), Standard_Integer);
6998 Check_Unset_Reference (Left_Opnd (N));
6999 Check_Unset_Reference (Right_Opnd (N));
7001 Set_Etype (N, B_Typ);
7002 Generate_Operator_Reference (N, B_Typ);
7005 -- Set overflow checking bit. Much cleverer code needed here eventually
7006 -- and perhaps the Resolve routines should be separated for the various
7007 -- arithmetic operations, since they will need different processing. ???
7009 if Nkind (N) in N_Op then
7010 if not Overflow_Checks_Suppressed (Etype (N)) then
7011 Enable_Overflow_Check (N);
7014 end Resolve_Op_Expon;
7016 --------------------
7017 -- Resolve_Op_Not --
7018 --------------------
7020 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7023 function Parent_Is_Boolean return Boolean;
7024 -- This function determines if the parent node is a boolean operator
7025 -- or operation (comparison op, membership test, or short circuit form)
7026 -- and the not in question is the left operand of this operation.
7027 -- Note that if the not is in parens, then false is returned.
7029 -----------------------
7030 -- Parent_Is_Boolean --
7031 -----------------------
7033 function Parent_Is_Boolean return Boolean is
7035 if Paren_Count (N) /= 0 then
7039 case Nkind (Parent (N)) is
7054 return Left_Opnd (Parent (N)) = N;
7060 end Parent_Is_Boolean;
7062 -- Start of processing for Resolve_Op_Not
7065 -- Predefined operations on scalar types yield the base type. On the
7066 -- other hand, logical operations on arrays yield the type of the
7067 -- arguments (and the context).
7069 if Is_Array_Type (Typ) then
7072 B_Typ := Base_Type (Typ);
7075 -- Straightforward case of incorrect arguments
7077 if not Valid_Boolean_Arg (Typ) then
7078 Error_Msg_N ("invalid operand type for operator&", N);
7079 Set_Etype (N, Any_Type);
7082 -- Special case of probable missing parens
7084 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7085 if Parent_Is_Boolean then
7087 ("operand of not must be enclosed in parentheses",
7091 ("no modular type available in this context", N);
7094 Set_Etype (N, Any_Type);
7097 -- OK resolution of not
7100 -- Warn if non-boolean types involved. This is a case like not a < b
7101 -- where a and b are modular, where we will get (not a) < b and most
7102 -- likely not (a < b) was intended.
7104 if Warn_On_Questionable_Missing_Parens
7105 and then not Is_Boolean_Type (Typ)
7106 and then Parent_Is_Boolean
7108 Error_Msg_N ("?not expression should be parenthesized here!", N);
7111 -- Warn on double negation if checking redundant constructs
7113 if Warn_On_Redundant_Constructs
7114 and then Comes_From_Source (N)
7115 and then Comes_From_Source (Right_Opnd (N))
7116 and then Root_Type (Typ) = Standard_Boolean
7117 and then Nkind (Right_Opnd (N)) = N_Op_Not
7119 Error_Msg_N ("redundant double negation?", N);
7122 -- Complete resolution and evaluation of NOT
7124 Resolve (Right_Opnd (N), B_Typ);
7125 Check_Unset_Reference (Right_Opnd (N));
7126 Set_Etype (N, B_Typ);
7127 Generate_Operator_Reference (N, B_Typ);
7132 -----------------------------
7133 -- Resolve_Operator_Symbol --
7134 -----------------------------
7136 -- Nothing to be done, all resolved already
7138 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7139 pragma Warnings (Off, N);
7140 pragma Warnings (Off, Typ);
7144 end Resolve_Operator_Symbol;
7146 ----------------------------------
7147 -- Resolve_Qualified_Expression --
7148 ----------------------------------
7150 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7151 pragma Warnings (Off, Typ);
7153 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7154 Expr : constant Node_Id := Expression (N);
7157 Resolve (Expr, Target_Typ);
7159 -- A qualified expression requires an exact match of the type,
7160 -- class-wide matching is not allowed. However, if the qualifying
7161 -- type is specific and the expression has a class-wide type, it
7162 -- may still be okay, since it can be the result of the expansion
7163 -- of a call to a dispatching function, so we also have to check
7164 -- class-wideness of the type of the expression's original node.
7166 if (Is_Class_Wide_Type (Target_Typ)
7168 (Is_Class_Wide_Type (Etype (Expr))
7169 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7170 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7172 Wrong_Type (Expr, Target_Typ);
7175 -- If the target type is unconstrained, then we reset the type of
7176 -- the result from the type of the expression. For other cases, the
7177 -- actual subtype of the expression is the target type.
7179 if Is_Composite_Type (Target_Typ)
7180 and then not Is_Constrained (Target_Typ)
7182 Set_Etype (N, Etype (Expr));
7185 Eval_Qualified_Expression (N);
7186 end Resolve_Qualified_Expression;
7192 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7193 L : constant Node_Id := Low_Bound (N);
7194 H : constant Node_Id := High_Bound (N);
7201 Check_Unset_Reference (L);
7202 Check_Unset_Reference (H);
7204 -- We have to check the bounds for being within the base range as
7205 -- required for a non-static context. Normally this is automatic and
7206 -- done as part of evaluating expressions, but the N_Range node is an
7207 -- exception, since in GNAT we consider this node to be a subexpression,
7208 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7209 -- this, but that would put the test on the main evaluation path for
7212 Check_Non_Static_Context (L);
7213 Check_Non_Static_Context (H);
7215 -- Check for an ambiguous range over character literals. This will
7216 -- happen with a membership test involving only literals.
7218 if Typ = Any_Character then
7219 Ambiguous_Character (L);
7220 Set_Etype (N, Any_Type);
7224 -- If bounds are static, constant-fold them, so size computations
7225 -- are identical between front-end and back-end. Do not perform this
7226 -- transformation while analyzing generic units, as type information
7227 -- would then be lost when reanalyzing the constant node in the
7230 if Is_Discrete_Type (Typ) and then Expander_Active then
7231 if Is_OK_Static_Expression (L) then
7232 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7235 if Is_OK_Static_Expression (H) then
7236 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7241 --------------------------
7242 -- Resolve_Real_Literal --
7243 --------------------------
7245 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7246 Actual_Typ : constant Entity_Id := Etype (N);
7249 -- Special processing for fixed-point literals to make sure that the
7250 -- value is an exact multiple of small where this is required. We
7251 -- skip this for the universal real case, and also for generic types.
7253 if Is_Fixed_Point_Type (Typ)
7254 and then Typ /= Universal_Fixed
7255 and then Typ /= Any_Fixed
7256 and then not Is_Generic_Type (Typ)
7259 Val : constant Ureal := Realval (N);
7260 Cintr : constant Ureal := Val / Small_Value (Typ);
7261 Cint : constant Uint := UR_Trunc (Cintr);
7262 Den : constant Uint := Norm_Den (Cintr);
7266 -- Case of literal is not an exact multiple of the Small
7270 -- For a source program literal for a decimal fixed-point
7271 -- type, this is statically illegal (RM 4.9(36)).
7273 if Is_Decimal_Fixed_Point_Type (Typ)
7274 and then Actual_Typ = Universal_Real
7275 and then Comes_From_Source (N)
7277 Error_Msg_N ("value has extraneous low order digits", N);
7280 -- Generate a warning if literal from source
7282 if Is_Static_Expression (N)
7283 and then Warn_On_Bad_Fixed_Value
7286 ("?static fixed-point value is not a multiple of Small!",
7290 -- Replace literal by a value that is the exact representation
7291 -- of a value of the type, i.e. a multiple of the small value,
7292 -- by truncation, since Machine_Rounds is false for all GNAT
7293 -- fixed-point types (RM 4.9(38)).
7295 Stat := Is_Static_Expression (N);
7297 Make_Real_Literal (Sloc (N),
7298 Realval => Small_Value (Typ) * Cint));
7300 Set_Is_Static_Expression (N, Stat);
7303 -- In all cases, set the corresponding integer field
7305 Set_Corresponding_Integer_Value (N, Cint);
7309 -- Now replace the actual type by the expected type as usual
7312 Eval_Real_Literal (N);
7313 end Resolve_Real_Literal;
7315 -----------------------
7316 -- Resolve_Reference --
7317 -----------------------
7319 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7320 P : constant Node_Id := Prefix (N);
7323 -- Replace general access with specific type
7325 if Ekind (Etype (N)) = E_Allocator_Type then
7326 Set_Etype (N, Base_Type (Typ));
7329 Resolve (P, Designated_Type (Etype (N)));
7331 -- If we are taking the reference of a volatile entity, then treat
7332 -- it as a potential modification of this entity. This is much too
7333 -- conservative, but is necessary because remove side effects can
7334 -- result in transformations of normal assignments into reference
7335 -- sequences that otherwise fail to notice the modification.
7337 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7338 Note_Possible_Modification (P, Sure => False);
7340 end Resolve_Reference;
7342 --------------------------------
7343 -- Resolve_Selected_Component --
7344 --------------------------------
7346 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7348 Comp1 : Entity_Id := Empty; -- prevent junk warning
7349 P : constant Node_Id := Prefix (N);
7350 S : constant Node_Id := Selector_Name (N);
7351 T : Entity_Id := Etype (P);
7353 I1 : Interp_Index := 0; -- prevent junk warning
7358 function Init_Component return Boolean;
7359 -- Check whether this is the initialization of a component within an
7360 -- init proc (by assignment or call to another init proc). If true,
7361 -- there is no need for a discriminant check.
7363 --------------------
7364 -- Init_Component --
7365 --------------------
7367 function Init_Component return Boolean is
7369 return Inside_Init_Proc
7370 and then Nkind (Prefix (N)) = N_Identifier
7371 and then Chars (Prefix (N)) = Name_uInit
7372 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7375 -- Start of processing for Resolve_Selected_Component
7378 if Is_Overloaded (P) then
7380 -- Use the context type to select the prefix that has a selector
7381 -- of the correct name and type.
7384 Get_First_Interp (P, I, It);
7386 Search : while Present (It.Typ) loop
7387 if Is_Access_Type (It.Typ) then
7388 T := Designated_Type (It.Typ);
7393 if Is_Record_Type (T) then
7395 -- The visible components of a class-wide type are those of
7398 if Is_Class_Wide_Type (T) then
7402 Comp := First_Entity (T);
7403 while Present (Comp) loop
7404 if Chars (Comp) = Chars (S)
7405 and then Covers (Etype (Comp), Typ)
7414 It := Disambiguate (P, I1, I, Any_Type);
7416 if It = No_Interp then
7418 ("ambiguous prefix for selected component", N);
7425 -- There may be an implicit dereference. Retrieve
7426 -- designated record type.
7428 if Is_Access_Type (It1.Typ) then
7429 T := Designated_Type (It1.Typ);
7434 if Scope (Comp1) /= T then
7436 -- Resolution chooses the new interpretation.
7437 -- Find the component with the right name.
7439 Comp1 := First_Entity (T);
7440 while Present (Comp1)
7441 and then Chars (Comp1) /= Chars (S)
7443 Comp1 := Next_Entity (Comp1);
7452 Comp := Next_Entity (Comp);
7457 Get_Next_Interp (I, It);
7460 Resolve (P, It1.Typ);
7462 Set_Entity_With_Style_Check (S, Comp1);
7465 -- Resolve prefix with its type
7470 -- Generate cross-reference. We needed to wait until full overloading
7471 -- resolution was complete to do this, since otherwise we can't tell if
7472 -- we are an Lvalue of not.
7474 if May_Be_Lvalue (N) then
7475 Generate_Reference (Entity (S), S, 'm');
7477 Generate_Reference (Entity (S), S, 'r');
7480 -- If prefix is an access type, the node will be transformed into an
7481 -- explicit dereference during expansion. The type of the node is the
7482 -- designated type of that of the prefix.
7484 if Is_Access_Type (Etype (P)) then
7485 T := Designated_Type (Etype (P));
7486 Check_Fully_Declared_Prefix (T, P);
7491 if Has_Discriminants (T)
7492 and then (Ekind (Entity (S)) = E_Component
7494 Ekind (Entity (S)) = E_Discriminant)
7495 and then Present (Original_Record_Component (Entity (S)))
7496 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7497 and then Present (Discriminant_Checking_Func
7498 (Original_Record_Component (Entity (S))))
7499 and then not Discriminant_Checks_Suppressed (T)
7500 and then not Init_Component
7502 Set_Do_Discriminant_Check (N);
7505 if Ekind (Entity (S)) = E_Void then
7506 Error_Msg_N ("premature use of component", S);
7509 -- If the prefix is a record conversion, this may be a renamed
7510 -- discriminant whose bounds differ from those of the original
7511 -- one, so we must ensure that a range check is performed.
7513 if Nkind (P) = N_Type_Conversion
7514 and then Ekind (Entity (S)) = E_Discriminant
7515 and then Is_Discrete_Type (Typ)
7517 Set_Etype (N, Base_Type (Typ));
7520 -- Note: No Eval processing is required, because the prefix is of a
7521 -- record type, or protected type, and neither can possibly be static.
7523 end Resolve_Selected_Component;
7529 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7530 B_Typ : constant Entity_Id := Base_Type (Typ);
7531 L : constant Node_Id := Left_Opnd (N);
7532 R : constant Node_Id := Right_Opnd (N);
7535 -- We do the resolution using the base type, because intermediate values
7536 -- in expressions always are of the base type, not a subtype of it.
7539 Resolve (R, Standard_Natural);
7541 Check_Unset_Reference (L);
7542 Check_Unset_Reference (R);
7544 Set_Etype (N, B_Typ);
7545 Generate_Operator_Reference (N, B_Typ);
7549 ---------------------------
7550 -- Resolve_Short_Circuit --
7551 ---------------------------
7553 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7554 B_Typ : constant Entity_Id := Base_Type (Typ);
7555 L : constant Node_Id := Left_Opnd (N);
7556 R : constant Node_Id := Right_Opnd (N);
7562 -- Check for issuing warning for always False assert/check, this happens
7563 -- when assertions are turned off, in which case the pragma Assert/Check
7564 -- was transformed into:
7566 -- if False and then <condition> then ...
7568 -- and we detect this pattern
7570 if Warn_On_Assertion_Failure
7571 and then Is_Entity_Name (R)
7572 and then Entity (R) = Standard_False
7573 and then Nkind (Parent (N)) = N_If_Statement
7574 and then Nkind (N) = N_And_Then
7575 and then Is_Entity_Name (L)
7576 and then Entity (L) = Standard_False
7579 Orig : constant Node_Id := Original_Node (Parent (N));
7582 if Nkind (Orig) = N_Pragma
7583 and then Pragma_Name (Orig) = Name_Assert
7585 -- Don't want to warn if original condition is explicit False
7588 Expr : constant Node_Id :=
7591 (First (Pragma_Argument_Associations (Orig))));
7593 if Is_Entity_Name (Expr)
7594 and then Entity (Expr) = Standard_False
7598 -- Issue warning. Note that we don't want to make this
7599 -- an unconditional warning, because if the assert is
7600 -- within deleted code we do not want the warning. But
7601 -- we do not want the deletion of the IF/AND-THEN to
7602 -- take this message with it. We achieve this by making
7603 -- sure that the expanded code points to the Sloc of
7604 -- the expression, not the original pragma.
7606 Error_Msg_N ("?assertion would fail at run-time", Orig);
7610 -- Similar processing for Check pragma
7612 elsif Nkind (Orig) = N_Pragma
7613 and then Pragma_Name (Orig) = Name_Check
7615 -- Don't want to warn if original condition is explicit False
7618 Expr : constant Node_Id :=
7622 (Pragma_Argument_Associations (Orig)))));
7624 if Is_Entity_Name (Expr)
7625 and then Entity (Expr) = Standard_False
7629 Error_Msg_N ("?check would fail at run-time", Orig);
7636 -- Continue with processing of short circuit
7638 Check_Unset_Reference (L);
7639 Check_Unset_Reference (R);
7641 Set_Etype (N, B_Typ);
7642 Eval_Short_Circuit (N);
7643 end Resolve_Short_Circuit;
7649 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7650 Name : constant Node_Id := Prefix (N);
7651 Drange : constant Node_Id := Discrete_Range (N);
7652 Array_Type : Entity_Id := Empty;
7656 if Is_Overloaded (Name) then
7658 -- Use the context type to select the prefix that yields the
7659 -- correct array type.
7663 I1 : Interp_Index := 0;
7665 P : constant Node_Id := Prefix (N);
7666 Found : Boolean := False;
7669 Get_First_Interp (P, I, It);
7670 while Present (It.Typ) loop
7671 if (Is_Array_Type (It.Typ)
7672 and then Covers (Typ, It.Typ))
7673 or else (Is_Access_Type (It.Typ)
7674 and then Is_Array_Type (Designated_Type (It.Typ))
7675 and then Covers (Typ, Designated_Type (It.Typ)))
7678 It := Disambiguate (P, I1, I, Any_Type);
7680 if It = No_Interp then
7681 Error_Msg_N ("ambiguous prefix for slicing", N);
7686 Array_Type := It.Typ;
7691 Array_Type := It.Typ;
7696 Get_Next_Interp (I, It);
7701 Array_Type := Etype (Name);
7704 Resolve (Name, Array_Type);
7706 if Is_Access_Type (Array_Type) then
7707 Apply_Access_Check (N);
7708 Array_Type := Designated_Type (Array_Type);
7710 -- If the prefix is an access to an unconstrained array, we must use
7711 -- the actual subtype of the object to perform the index checks. The
7712 -- object denoted by the prefix is implicit in the node, so we build
7713 -- an explicit representation for it in order to compute the actual
7716 if not Is_Constrained (Array_Type) then
7717 Remove_Side_Effects (Prefix (N));
7720 Obj : constant Node_Id :=
7721 Make_Explicit_Dereference (Sloc (N),
7722 Prefix => New_Copy_Tree (Prefix (N)));
7724 Set_Etype (Obj, Array_Type);
7725 Set_Parent (Obj, Parent (N));
7726 Array_Type := Get_Actual_Subtype (Obj);
7730 elsif Is_Entity_Name (Name)
7731 or else (Nkind (Name) = N_Function_Call
7732 and then not Is_Constrained (Etype (Name)))
7734 Array_Type := Get_Actual_Subtype (Name);
7736 -- If the name is a selected component that depends on discriminants,
7737 -- build an actual subtype for it. This can happen only when the name
7738 -- itself is overloaded; otherwise the actual subtype is created when
7739 -- the selected component is analyzed.
7741 elsif Nkind (Name) = N_Selected_Component
7742 and then Full_Analysis
7743 and then Depends_On_Discriminant (First_Index (Array_Type))
7746 Act_Decl : constant Node_Id :=
7747 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7749 Insert_Action (N, Act_Decl);
7750 Array_Type := Defining_Identifier (Act_Decl);
7754 -- If name was overloaded, set slice type correctly now
7756 Set_Etype (N, Array_Type);
7758 -- If the range is specified by a subtype mark, no resolution is
7759 -- necessary. Else resolve the bounds, and apply needed checks.
7761 if not Is_Entity_Name (Drange) then
7762 Index := First_Index (Array_Type);
7763 Resolve (Drange, Base_Type (Etype (Index)));
7765 if Nkind (Drange) = N_Range
7767 -- Do not apply the range check to nodes associated with the
7768 -- frontend expansion of the dispatch table. We first check
7769 -- if Ada.Tags is already loaded to void the addition of an
7770 -- undesired dependence on such run-time unit.
7775 (RTU_Loaded (Ada_Tags)
7776 and then Nkind (Prefix (N)) = N_Selected_Component
7777 and then Present (Entity (Selector_Name (Prefix (N))))
7778 and then Entity (Selector_Name (Prefix (N))) =
7779 RTE_Record_Component (RE_Prims_Ptr)))
7781 Apply_Range_Check (Drange, Etype (Index));
7785 Set_Slice_Subtype (N);
7787 if Nkind (Drange) = N_Range then
7788 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7789 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7795 ----------------------------
7796 -- Resolve_String_Literal --
7797 ----------------------------
7799 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7800 C_Typ : constant Entity_Id := Component_Type (Typ);
7801 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7802 Loc : constant Source_Ptr := Sloc (N);
7803 Str : constant String_Id := Strval (N);
7804 Strlen : constant Nat := String_Length (Str);
7805 Subtype_Id : Entity_Id;
7806 Need_Check : Boolean;
7809 -- For a string appearing in a concatenation, defer creation of the
7810 -- string_literal_subtype until the end of the resolution of the
7811 -- concatenation, because the literal may be constant-folded away. This
7812 -- is a useful optimization for long concatenation expressions.
7814 -- If the string is an aggregate built for a single character (which
7815 -- happens in a non-static context) or a is null string to which special
7816 -- checks may apply, we build the subtype. Wide strings must also get a
7817 -- string subtype if they come from a one character aggregate. Strings
7818 -- generated by attributes might be static, but it is often hard to
7819 -- determine whether the enclosing context is static, so we generate
7820 -- subtypes for them as well, thus losing some rarer optimizations ???
7821 -- Same for strings that come from a static conversion.
7824 (Strlen = 0 and then Typ /= Standard_String)
7825 or else Nkind (Parent (N)) /= N_Op_Concat
7826 or else (N /= Left_Opnd (Parent (N))
7827 and then N /= Right_Opnd (Parent (N)))
7828 or else ((Typ = Standard_Wide_String
7829 or else Typ = Standard_Wide_Wide_String)
7830 and then Nkind (Original_Node (N)) /= N_String_Literal);
7832 -- If the resolving type is itself a string literal subtype, we
7833 -- can just reuse it, since there is no point in creating another.
7835 if Ekind (Typ) = E_String_Literal_Subtype then
7838 elsif Nkind (Parent (N)) = N_Op_Concat
7839 and then not Need_Check
7840 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7841 N_Attribute_Reference,
7842 N_Qualified_Expression,
7847 -- Otherwise we must create a string literal subtype. Note that the
7848 -- whole idea of string literal subtypes is simply to avoid the need
7849 -- for building a full fledged array subtype for each literal.
7852 Set_String_Literal_Subtype (N, Typ);
7853 Subtype_Id := Etype (N);
7856 if Nkind (Parent (N)) /= N_Op_Concat
7859 Set_Etype (N, Subtype_Id);
7860 Eval_String_Literal (N);
7863 if Is_Limited_Composite (Typ)
7864 or else Is_Private_Composite (Typ)
7866 Error_Msg_N ("string literal not available for private array", N);
7867 Set_Etype (N, Any_Type);
7871 -- The validity of a null string has been checked in the
7872 -- call to Eval_String_Literal.
7877 -- Always accept string literal with component type Any_Character, which
7878 -- occurs in error situations and in comparisons of literals, both of
7879 -- which should accept all literals.
7881 elsif R_Typ = Any_Character then
7884 -- If the type is bit-packed, then we always transform the string
7885 -- literal into a full fledged aggregate.
7887 elsif Is_Bit_Packed_Array (Typ) then
7890 -- Deal with cases of Wide_Wide_String, Wide_String, and String
7893 -- For Standard.Wide_Wide_String, or any other type whose component
7894 -- type is Standard.Wide_Wide_Character, we know that all the
7895 -- characters in the string must be acceptable, since the parser
7896 -- accepted the characters as valid character literals.
7898 if R_Typ = Standard_Wide_Wide_Character then
7901 -- For the case of Standard.String, or any other type whose component
7902 -- type is Standard.Character, we must make sure that there are no
7903 -- wide characters in the string, i.e. that it is entirely composed
7904 -- of characters in range of type Character.
7906 -- If the string literal is the result of a static concatenation, the
7907 -- test has already been performed on the components, and need not be
7910 elsif R_Typ = Standard_Character
7911 and then Nkind (Original_Node (N)) /= N_Op_Concat
7913 for J in 1 .. Strlen loop
7914 if not In_Character_Range (Get_String_Char (Str, J)) then
7916 -- If we are out of range, post error. This is one of the
7917 -- very few places that we place the flag in the middle of
7918 -- a token, right under the offending wide character.
7921 ("literal out of range of type Standard.Character",
7922 Source_Ptr (Int (Loc) + J));
7927 -- For the case of Standard.Wide_String, or any other type whose
7928 -- component type is Standard.Wide_Character, we must make sure that
7929 -- there are no wide characters in the string, i.e. that it is
7930 -- entirely composed of characters in range of type Wide_Character.
7932 -- If the string literal is the result of a static concatenation,
7933 -- the test has already been performed on the components, and need
7936 elsif R_Typ = Standard_Wide_Character
7937 and then Nkind (Original_Node (N)) /= N_Op_Concat
7939 for J in 1 .. Strlen loop
7940 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
7942 -- If we are out of range, post error. This is one of the
7943 -- very few places that we place the flag in the middle of
7944 -- a token, right under the offending wide character.
7946 -- This is not quite right, because characters in general
7947 -- will take more than one character position ???
7950 ("literal out of range of type Standard.Wide_Character",
7951 Source_Ptr (Int (Loc) + J));
7956 -- If the root type is not a standard character, then we will convert
7957 -- the string into an aggregate and will let the aggregate code do
7958 -- the checking. Standard Wide_Wide_Character is also OK here.
7964 -- See if the component type of the array corresponding to the string
7965 -- has compile time known bounds. If yes we can directly check
7966 -- whether the evaluation of the string will raise constraint error.
7967 -- Otherwise we need to transform the string literal into the
7968 -- corresponding character aggregate and let the aggregate
7969 -- code do the checking.
7971 if Is_Standard_Character_Type (R_Typ) then
7973 -- Check for the case of full range, where we are definitely OK
7975 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
7979 -- Here the range is not the complete base type range, so check
7982 Comp_Typ_Lo : constant Node_Id :=
7983 Type_Low_Bound (Component_Type (Typ));
7984 Comp_Typ_Hi : constant Node_Id :=
7985 Type_High_Bound (Component_Type (Typ));
7990 if Compile_Time_Known_Value (Comp_Typ_Lo)
7991 and then Compile_Time_Known_Value (Comp_Typ_Hi)
7993 for J in 1 .. Strlen loop
7994 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
7996 if Char_Val < Expr_Value (Comp_Typ_Lo)
7997 or else Char_Val > Expr_Value (Comp_Typ_Hi)
7999 Apply_Compile_Time_Constraint_Error
8000 (N, "character out of range?", CE_Range_Check_Failed,
8001 Loc => Source_Ptr (Int (Loc) + J));
8011 -- If we got here we meed to transform the string literal into the
8012 -- equivalent qualified positional array aggregate. This is rather
8013 -- heavy artillery for this situation, but it is hard work to avoid.
8016 Lits : constant List_Id := New_List;
8017 P : Source_Ptr := Loc + 1;
8021 -- Build the character literals, we give them source locations that
8022 -- correspond to the string positions, which is a bit tricky given
8023 -- the possible presence of wide character escape sequences.
8025 for J in 1 .. Strlen loop
8026 C := Get_String_Char (Str, J);
8027 Set_Character_Literal_Name (C);
8030 Make_Character_Literal (P,
8032 Char_Literal_Value => UI_From_CC (C)));
8034 if In_Character_Range (C) then
8037 -- Should we have a call to Skip_Wide here ???
8045 Make_Qualified_Expression (Loc,
8046 Subtype_Mark => New_Reference_To (Typ, Loc),
8048 Make_Aggregate (Loc, Expressions => Lits)));
8050 Analyze_And_Resolve (N, Typ);
8052 end Resolve_String_Literal;
8054 -----------------------------
8055 -- Resolve_Subprogram_Info --
8056 -----------------------------
8058 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8061 end Resolve_Subprogram_Info;
8063 -----------------------------
8064 -- Resolve_Type_Conversion --
8065 -----------------------------
8067 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8068 Conv_OK : constant Boolean := Conversion_OK (N);
8069 Operand : constant Node_Id := Expression (N);
8070 Operand_Typ : constant Entity_Id := Etype (Operand);
8071 Target_Typ : constant Entity_Id := Etype (N);
8078 and then not Valid_Conversion (N, Target_Typ, Operand)
8083 if Etype (Operand) = Any_Fixed then
8085 -- Mixed-mode operation involving a literal. Context must be a fixed
8086 -- type which is applied to the literal subsequently.
8088 if Is_Fixed_Point_Type (Typ) then
8089 Set_Etype (Operand, Universal_Real);
8091 elsif Is_Numeric_Type (Typ)
8092 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8093 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8095 Etype (Left_Opnd (Operand)) = Universal_Real)
8097 -- Return if expression is ambiguous
8099 if Unique_Fixed_Point_Type (N) = Any_Type then
8102 -- If nothing else, the available fixed type is Duration
8105 Set_Etype (Operand, Standard_Duration);
8108 -- Resolve the real operand with largest available precision
8110 if Etype (Right_Opnd (Operand)) = Universal_Real then
8111 Rop := New_Copy_Tree (Right_Opnd (Operand));
8113 Rop := New_Copy_Tree (Left_Opnd (Operand));
8116 Resolve (Rop, Universal_Real);
8118 -- If the operand is a literal (it could be a non-static and
8119 -- illegal exponentiation) check whether the use of Duration
8120 -- is potentially inaccurate.
8122 if Nkind (Rop) = N_Real_Literal
8123 and then Realval (Rop) /= Ureal_0
8124 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8127 ("?universal real operand can only " &
8128 "be interpreted as Duration!",
8131 ("\?precision will be lost in the conversion!", Rop);
8134 elsif Is_Numeric_Type (Typ)
8135 and then Nkind (Operand) in N_Op
8136 and then Unique_Fixed_Point_Type (N) /= Any_Type
8138 Set_Etype (Operand, Standard_Duration);
8141 Error_Msg_N ("invalid context for mixed mode operation", N);
8142 Set_Etype (Operand, Any_Type);
8149 -- Note: we do the Eval_Type_Conversion call before applying the
8150 -- required checks for a subtype conversion. This is important,
8151 -- since both are prepared under certain circumstances to change
8152 -- the type conversion to a constraint error node, but in the case
8153 -- of Eval_Type_Conversion this may reflect an illegality in the
8154 -- static case, and we would miss the illegality (getting only a
8155 -- warning message), if we applied the type conversion checks first.
8157 Eval_Type_Conversion (N);
8159 -- Even when evaluation is not possible, we may be able to simplify
8160 -- the conversion or its expression. This needs to be done before
8161 -- applying checks, since otherwise the checks may use the original
8162 -- expression and defeat the simplifications. This is specifically
8163 -- the case for elimination of the floating-point Truncation
8164 -- attribute in float-to-int conversions.
8166 Simplify_Type_Conversion (N);
8168 -- If after evaluation we still have a type conversion, then we
8169 -- may need to apply checks required for a subtype conversion.
8171 -- Skip these type conversion checks if universal fixed operands
8172 -- operands involved, since range checks are handled separately for
8173 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8175 if Nkind (N) = N_Type_Conversion
8176 and then not Is_Generic_Type (Root_Type (Target_Typ))
8177 and then Target_Typ /= Universal_Fixed
8178 and then Operand_Typ /= Universal_Fixed
8180 Apply_Type_Conversion_Checks (N);
8183 -- Issue warning for conversion of simple object to its own type
8184 -- We have to test the original nodes, since they may have been
8185 -- rewritten by various optimizations.
8187 Orig_N := Original_Node (N);
8189 if Warn_On_Redundant_Constructs
8190 and then Comes_From_Source (Orig_N)
8191 and then Nkind (Orig_N) = N_Type_Conversion
8192 and then not In_Instance
8194 Orig_N := Original_Node (Expression (Orig_N));
8195 Orig_T := Target_Typ;
8197 -- If the node is part of a larger expression, the Target_Type
8198 -- may not be the original type of the node if the context is a
8199 -- condition. Recover original type to see if conversion is needed.
8201 if Is_Boolean_Type (Orig_T)
8202 and then Nkind (Parent (N)) in N_Op
8204 Orig_T := Etype (Parent (N));
8207 if Is_Entity_Name (Orig_N)
8209 (Etype (Entity (Orig_N)) = Orig_T
8211 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8212 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8214 Error_Msg_Node_2 := Orig_T;
8216 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8220 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8221 -- No need to perform any interface conversion if the type of the
8222 -- expression coincides with the target type.
8224 if Ada_Version >= Ada_05
8225 and then Expander_Active
8226 and then Operand_Typ /= Target_Typ
8229 Opnd : Entity_Id := Operand_Typ;
8230 Target : Entity_Id := Target_Typ;
8233 if Is_Access_Type (Opnd) then
8234 Opnd := Directly_Designated_Type (Opnd);
8237 if Is_Access_Type (Target_Typ) then
8238 Target := Directly_Designated_Type (Target);
8241 if Opnd = Target then
8244 -- Conversion from interface type
8246 elsif Is_Interface (Opnd) then
8248 -- Ada 2005 (AI-217): Handle entities from limited views
8250 if From_With_Type (Opnd) then
8251 Error_Msg_Qual_Level := 99;
8252 Error_Msg_NE ("missing with-clause on package &", N,
8253 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8255 ("type conversions require visibility of the full view",
8258 elsif From_With_Type (Target)
8260 (Is_Access_Type (Target_Typ)
8261 and then Present (Non_Limited_View (Etype (Target))))
8263 Error_Msg_Qual_Level := 99;
8264 Error_Msg_NE ("missing with-clause on package &", N,
8265 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8267 ("type conversions require visibility of the full view",
8271 Expand_Interface_Conversion (N, Is_Static => False);
8274 -- Conversion to interface type
8276 elsif Is_Interface (Target) then
8280 if Ekind (Opnd) = E_Protected_Subtype
8281 or else Ekind (Opnd) = E_Task_Subtype
8283 Opnd := Etype (Opnd);
8286 if not Interface_Present_In_Ancestor
8290 if Is_Class_Wide_Type (Opnd) then
8292 -- The static analysis is not enough to know if the
8293 -- interface is implemented or not. Hence we must pass
8294 -- the work to the expander to generate code to evaluate
8295 -- the conversion at run-time.
8297 Expand_Interface_Conversion (N, Is_Static => False);
8300 Error_Msg_Name_1 := Chars (Etype (Target));
8301 Error_Msg_Name_2 := Chars (Opnd);
8303 ("wrong interface conversion (% is not a progenitor " &
8308 Expand_Interface_Conversion (N);
8313 end Resolve_Type_Conversion;
8315 ----------------------
8316 -- Resolve_Unary_Op --
8317 ----------------------
8319 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8320 B_Typ : constant Entity_Id := Base_Type (Typ);
8321 R : constant Node_Id := Right_Opnd (N);
8327 -- Deal with intrinsic unary operators
8329 if Comes_From_Source (N)
8330 and then Ekind (Entity (N)) = E_Function
8331 and then Is_Imported (Entity (N))
8332 and then Is_Intrinsic_Subprogram (Entity (N))
8334 Resolve_Intrinsic_Unary_Operator (N, Typ);
8338 -- Deal with universal cases
8340 if Etype (R) = Universal_Integer
8342 Etype (R) = Universal_Real
8344 Check_For_Visible_Operator (N, B_Typ);
8347 Set_Etype (N, B_Typ);
8350 -- Generate warning for expressions like abs (x mod 2)
8352 if Warn_On_Redundant_Constructs
8353 and then Nkind (N) = N_Op_Abs
8355 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8357 if OK and then Hi >= Lo and then Lo >= 0 then
8359 ("?abs applied to known non-negative value has no effect", N);
8363 -- Deal with reference generation
8365 Check_Unset_Reference (R);
8366 Generate_Operator_Reference (N, B_Typ);
8369 -- Set overflow checking bit. Much cleverer code needed here eventually
8370 -- and perhaps the Resolve routines should be separated for the various
8371 -- arithmetic operations, since they will need different processing ???
8373 if Nkind (N) in N_Op then
8374 if not Overflow_Checks_Suppressed (Etype (N)) then
8375 Enable_Overflow_Check (N);
8379 -- Generate warning for expressions like -5 mod 3 for integers. No
8380 -- need to worry in the floating-point case, since parens do not affect
8381 -- the result so there is no point in giving in a warning.
8384 Norig : constant Node_Id := Original_Node (N);
8393 if Warn_On_Questionable_Missing_Parens
8394 and then Comes_From_Source (Norig)
8395 and then Is_Integer_Type (Typ)
8396 and then Nkind (Norig) = N_Op_Minus
8398 Rorig := Original_Node (Right_Opnd (Norig));
8400 -- We are looking for cases where the right operand is not
8401 -- parenthesized, and is a binary operator, multiply, divide, or
8402 -- mod. These are the cases where the grouping can affect results.
8404 if Paren_Count (Rorig) = 0
8405 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8407 -- For mod, we always give the warning, since the value is
8408 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8409 -- (5 mod 315)). But for the other cases, the only concern is
8410 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8411 -- overflows, but (-2) * 64 does not). So we try to give the
8412 -- message only when overflow is possible.
8414 if Nkind (Rorig) /= N_Op_Mod
8415 and then Compile_Time_Known_Value (R)
8417 Val := Expr_Value (R);
8419 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8420 HB := Expr_Value (Type_High_Bound (Typ));
8422 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8425 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8426 LB := Expr_Value (Type_Low_Bound (Typ));
8428 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8431 -- Note that the test below is deliberately excluding
8432 -- the largest negative number, since that is a potentially
8433 -- troublesome case (e.g. -2 * x, where the result is the
8434 -- largest negative integer has an overflow with 2 * x).
8436 if Val > LB and then Val <= HB then
8441 -- For the multiplication case, the only case we have to worry
8442 -- about is when (-a)*b is exactly the largest negative number
8443 -- so that -(a*b) can cause overflow. This can only happen if
8444 -- a is a power of 2, and more generally if any operand is a
8445 -- constant that is not a power of 2, then the parentheses
8446 -- cannot affect whether overflow occurs. We only bother to
8447 -- test the left most operand
8449 -- Loop looking at left operands for one that has known value
8452 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8453 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8454 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8456 -- Operand value of 0 or 1 skips warning
8461 -- Otherwise check power of 2, if power of 2, warn, if
8462 -- anything else, skip warning.
8465 while Lval /= 2 loop
8466 if Lval mod 2 = 1 then
8477 -- Keep looking at left operands
8479 Opnd := Left_Opnd (Opnd);
8482 -- For rem or "/" we can only have a problematic situation
8483 -- if the divisor has a value of minus one or one. Otherwise
8484 -- overflow is impossible (divisor > 1) or we have a case of
8485 -- division by zero in any case.
8487 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8488 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8489 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8494 -- If we fall through warning should be issued
8497 ("?unary minus expression should be parenthesized here!", N);
8501 end Resolve_Unary_Op;
8503 ----------------------------------
8504 -- Resolve_Unchecked_Expression --
8505 ----------------------------------
8507 procedure Resolve_Unchecked_Expression
8512 Resolve (Expression (N), Typ, Suppress => All_Checks);
8514 end Resolve_Unchecked_Expression;
8516 ---------------------------------------
8517 -- Resolve_Unchecked_Type_Conversion --
8518 ---------------------------------------
8520 procedure Resolve_Unchecked_Type_Conversion
8524 pragma Warnings (Off, Typ);
8526 Operand : constant Node_Id := Expression (N);
8527 Opnd_Type : constant Entity_Id := Etype (Operand);
8530 -- Resolve operand using its own type
8532 Resolve (Operand, Opnd_Type);
8533 Eval_Unchecked_Conversion (N);
8535 end Resolve_Unchecked_Type_Conversion;
8537 ------------------------------
8538 -- Rewrite_Operator_As_Call --
8539 ------------------------------
8541 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8542 Loc : constant Source_Ptr := Sloc (N);
8543 Actuals : constant List_Id := New_List;
8547 if Nkind (N) in N_Binary_Op then
8548 Append (Left_Opnd (N), Actuals);
8551 Append (Right_Opnd (N), Actuals);
8554 Make_Function_Call (Sloc => Loc,
8555 Name => New_Occurrence_Of (Nam, Loc),
8556 Parameter_Associations => Actuals);
8558 Preserve_Comes_From_Source (New_N, N);
8559 Preserve_Comes_From_Source (Name (New_N), N);
8561 Set_Etype (N, Etype (Nam));
8562 end Rewrite_Operator_As_Call;
8564 ------------------------------
8565 -- Rewrite_Renamed_Operator --
8566 ------------------------------
8568 procedure Rewrite_Renamed_Operator
8573 Nam : constant Name_Id := Chars (Op);
8574 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8578 -- Rewrite the operator node using the real operator, not its
8579 -- renaming. Exclude user-defined intrinsic operations of the same
8580 -- name, which are treated separately and rewritten as calls.
8582 if Ekind (Op) /= E_Function
8583 or else Chars (N) /= Nam
8585 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8586 Set_Chars (Op_Node, Nam);
8587 Set_Etype (Op_Node, Etype (N));
8588 Set_Entity (Op_Node, Op);
8589 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8591 -- Indicate that both the original entity and its renaming are
8592 -- referenced at this point.
8594 Generate_Reference (Entity (N), N);
8595 Generate_Reference (Op, N);
8598 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8601 Rewrite (N, Op_Node);
8603 -- If the context type is private, add the appropriate conversions
8604 -- so that the operator is applied to the full view. This is done
8605 -- in the routines that resolve intrinsic operators,
8607 if Is_Intrinsic_Subprogram (Op)
8608 and then Is_Private_Type (Typ)
8611 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8612 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8613 Resolve_Intrinsic_Operator (N, Typ);
8615 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8616 Resolve_Intrinsic_Unary_Operator (N, Typ);
8623 elsif Ekind (Op) = E_Function
8624 and then Is_Intrinsic_Subprogram (Op)
8626 -- Operator renames a user-defined operator of the same name. Use
8627 -- the original operator in the node, which is the one that Gigi
8631 Set_Is_Overloaded (N, False);
8633 end Rewrite_Renamed_Operator;
8635 -----------------------
8636 -- Set_Slice_Subtype --
8637 -----------------------
8639 -- Build an implicit subtype declaration to represent the type delivered
8640 -- by the slice. This is an abbreviated version of an array subtype. We
8641 -- define an index subtype for the slice, using either the subtype name
8642 -- or the discrete range of the slice. To be consistent with index usage
8643 -- elsewhere, we create a list header to hold the single index. This list
8644 -- is not otherwise attached to the syntax tree.
8646 procedure Set_Slice_Subtype (N : Node_Id) is
8647 Loc : constant Source_Ptr := Sloc (N);
8648 Index_List : constant List_Id := New_List;
8650 Index_Subtype : Entity_Id;
8651 Index_Type : Entity_Id;
8652 Slice_Subtype : Entity_Id;
8653 Drange : constant Node_Id := Discrete_Range (N);
8656 if Is_Entity_Name (Drange) then
8657 Index_Subtype := Entity (Drange);
8660 -- We force the evaluation of a range. This is definitely needed in
8661 -- the renamed case, and seems safer to do unconditionally. Note in
8662 -- any case that since we will create and insert an Itype referring
8663 -- to this range, we must make sure any side effect removal actions
8664 -- are inserted before the Itype definition.
8666 if Nkind (Drange) = N_Range then
8667 Force_Evaluation (Low_Bound (Drange));
8668 Force_Evaluation (High_Bound (Drange));
8671 Index_Type := Base_Type (Etype (Drange));
8673 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8675 Set_Scalar_Range (Index_Subtype, Drange);
8676 Set_Etype (Index_Subtype, Index_Type);
8677 Set_Size_Info (Index_Subtype, Index_Type);
8678 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8681 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8683 Index := New_Occurrence_Of (Index_Subtype, Loc);
8684 Set_Etype (Index, Index_Subtype);
8685 Append (Index, Index_List);
8687 Set_First_Index (Slice_Subtype, Index);
8688 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8689 Set_Is_Constrained (Slice_Subtype, True);
8691 Check_Compile_Time_Size (Slice_Subtype);
8693 -- The Etype of the existing Slice node is reset to this slice subtype.
8694 -- Its bounds are obtained from its first index.
8696 Set_Etype (N, Slice_Subtype);
8698 -- In the packed case, this must be immediately frozen
8700 -- Couldn't we always freeze here??? and if we did, then the above
8701 -- call to Check_Compile_Time_Size could be eliminated, which would
8702 -- be nice, because then that routine could be made private to Freeze.
8704 -- Why the test for In_Spec_Expression here ???
8706 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8707 Freeze_Itype (Slice_Subtype, N);
8710 end Set_Slice_Subtype;
8712 --------------------------------
8713 -- Set_String_Literal_Subtype --
8714 --------------------------------
8716 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8717 Loc : constant Source_Ptr := Sloc (N);
8718 Low_Bound : constant Node_Id :=
8719 Type_Low_Bound (Etype (First_Index (Typ)));
8720 Subtype_Id : Entity_Id;
8723 if Nkind (N) /= N_String_Literal then
8727 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8728 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8729 (String_Length (Strval (N))));
8730 Set_Etype (Subtype_Id, Base_Type (Typ));
8731 Set_Is_Constrained (Subtype_Id);
8732 Set_Etype (N, Subtype_Id);
8734 if Is_OK_Static_Expression (Low_Bound) then
8736 -- The low bound is set from the low bound of the corresponding
8737 -- index type. Note that we do not store the high bound in the
8738 -- string literal subtype, but it can be deduced if necessary
8739 -- from the length and the low bound.
8741 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8744 Set_String_Literal_Low_Bound
8745 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8746 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8748 -- Build bona fide subtype for the string, and wrap it in an
8749 -- unchecked conversion, because the backend expects the
8750 -- String_Literal_Subtype to have a static lower bound.
8753 Index_List : constant List_Id := New_List;
8754 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8755 High_Bound : constant Node_Id :=
8757 Left_Opnd => New_Copy_Tree (Low_Bound),
8759 Make_Integer_Literal (Loc,
8760 String_Length (Strval (N)) - 1));
8761 Array_Subtype : Entity_Id;
8762 Index_Subtype : Entity_Id;
8768 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8769 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8770 Set_Scalar_Range (Index_Subtype, Drange);
8771 Set_Parent (Drange, N);
8772 Analyze_And_Resolve (Drange, Index_Type);
8774 -- In the context, the Index_Type may already have a constraint,
8775 -- so use common base type on string subtype. The base type may
8776 -- be used when generating attributes of the string, for example
8777 -- in the context of a slice assignment.
8779 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8780 Set_Size_Info (Index_Subtype, Index_Type);
8781 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8783 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8785 Index := New_Occurrence_Of (Index_Subtype, Loc);
8786 Set_Etype (Index, Index_Subtype);
8787 Append (Index, Index_List);
8789 Set_First_Index (Array_Subtype, Index);
8790 Set_Etype (Array_Subtype, Base_Type (Typ));
8791 Set_Is_Constrained (Array_Subtype, True);
8794 Make_Unchecked_Type_Conversion (Loc,
8795 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8796 Expression => Relocate_Node (N)));
8797 Set_Etype (N, Array_Subtype);
8800 end Set_String_Literal_Subtype;
8802 ------------------------------
8803 -- Simplify_Type_Conversion --
8804 ------------------------------
8806 procedure Simplify_Type_Conversion (N : Node_Id) is
8808 if Nkind (N) = N_Type_Conversion then
8810 Operand : constant Node_Id := Expression (N);
8811 Target_Typ : constant Entity_Id := Etype (N);
8812 Opnd_Typ : constant Entity_Id := Etype (Operand);
8815 if Is_Floating_Point_Type (Opnd_Typ)
8817 (Is_Integer_Type (Target_Typ)
8818 or else (Is_Fixed_Point_Type (Target_Typ)
8819 and then Conversion_OK (N)))
8820 and then Nkind (Operand) = N_Attribute_Reference
8821 and then Attribute_Name (Operand) = Name_Truncation
8823 -- Special processing required if the conversion is the expression
8824 -- of a Truncation attribute reference. In this case we replace:
8826 -- ityp (ftyp'Truncation (x))
8832 -- with the Float_Truncate flag set, which is more efficient
8836 Relocate_Node (First (Expressions (Operand))));
8837 Set_Float_Truncate (N, True);
8841 end Simplify_Type_Conversion;
8843 -----------------------------
8844 -- Unique_Fixed_Point_Type --
8845 -----------------------------
8847 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8848 T1 : Entity_Id := Empty;
8853 procedure Fixed_Point_Error;
8854 -- If true ambiguity, give details
8856 -----------------------
8857 -- Fixed_Point_Error --
8858 -----------------------
8860 procedure Fixed_Point_Error is
8862 Error_Msg_N ("ambiguous universal_fixed_expression", N);
8863 Error_Msg_NE ("\\possible interpretation as}", N, T1);
8864 Error_Msg_NE ("\\possible interpretation as}", N, T2);
8865 end Fixed_Point_Error;
8867 -- Start of processing for Unique_Fixed_Point_Type
8870 -- The operations on Duration are visible, so Duration is always a
8871 -- possible interpretation.
8873 T1 := Standard_Duration;
8875 -- Look for fixed-point types in enclosing scopes
8877 Scop := Current_Scope;
8878 while Scop /= Standard_Standard loop
8879 T2 := First_Entity (Scop);
8880 while Present (T2) loop
8881 if Is_Fixed_Point_Type (T2)
8882 and then Current_Entity (T2) = T2
8883 and then Scope (Base_Type (T2)) = Scop
8885 if Present (T1) then
8896 Scop := Scope (Scop);
8899 -- Look for visible fixed type declarations in the context
8901 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
8902 while Present (Item) loop
8903 if Nkind (Item) = N_With_Clause then
8904 Scop := Entity (Name (Item));
8905 T2 := First_Entity (Scop);
8906 while Present (T2) loop
8907 if Is_Fixed_Point_Type (T2)
8908 and then Scope (Base_Type (T2)) = Scop
8909 and then (Is_Potentially_Use_Visible (T2)
8910 or else In_Use (T2))
8912 if Present (T1) then
8927 if Nkind (N) = N_Real_Literal then
8928 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
8930 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
8934 end Unique_Fixed_Point_Type;
8936 ----------------------
8937 -- Valid_Conversion --
8938 ----------------------
8940 function Valid_Conversion
8943 Operand : Node_Id) return Boolean
8945 Target_Type : constant Entity_Id := Base_Type (Target);
8946 Opnd_Type : Entity_Id := Etype (Operand);
8948 function Conversion_Check
8950 Msg : String) return Boolean;
8951 -- Little routine to post Msg if Valid is False, returns Valid value
8953 function Valid_Tagged_Conversion
8954 (Target_Type : Entity_Id;
8955 Opnd_Type : Entity_Id) return Boolean;
8956 -- Specifically test for validity of tagged conversions
8958 function Valid_Array_Conversion return Boolean;
8959 -- Check index and component conformance, and accessibility levels
8960 -- if the component types are anonymous access types (Ada 2005)
8962 ----------------------
8963 -- Conversion_Check --
8964 ----------------------
8966 function Conversion_Check
8968 Msg : String) return Boolean
8972 Error_Msg_N (Msg, Operand);
8976 end Conversion_Check;
8978 ----------------------------
8979 -- Valid_Array_Conversion --
8980 ----------------------------
8982 function Valid_Array_Conversion return Boolean
8984 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
8985 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
8987 Opnd_Index : Node_Id;
8988 Opnd_Index_Type : Entity_Id;
8990 Target_Comp_Type : constant Entity_Id :=
8991 Component_Type (Target_Type);
8992 Target_Comp_Base : constant Entity_Id :=
8993 Base_Type (Target_Comp_Type);
8995 Target_Index : Node_Id;
8996 Target_Index_Type : Entity_Id;
8999 -- Error if wrong number of dimensions
9002 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9005 ("incompatible number of dimensions for conversion", Operand);
9008 -- Number of dimensions matches
9011 -- Loop through indexes of the two arrays
9013 Target_Index := First_Index (Target_Type);
9014 Opnd_Index := First_Index (Opnd_Type);
9015 while Present (Target_Index) and then Present (Opnd_Index) loop
9016 Target_Index_Type := Etype (Target_Index);
9017 Opnd_Index_Type := Etype (Opnd_Index);
9019 -- Error if index types are incompatible
9021 if not (Is_Integer_Type (Target_Index_Type)
9022 and then Is_Integer_Type (Opnd_Index_Type))
9023 and then (Root_Type (Target_Index_Type)
9024 /= Root_Type (Opnd_Index_Type))
9027 ("incompatible index types for array conversion",
9032 Next_Index (Target_Index);
9033 Next_Index (Opnd_Index);
9036 -- If component types have same base type, all set
9038 if Target_Comp_Base = Opnd_Comp_Base then
9041 -- Here if base types of components are not the same. The only
9042 -- time this is allowed is if we have anonymous access types.
9044 -- The conversion of arrays of anonymous access types can lead
9045 -- to dangling pointers. AI-392 formalizes the accessibility
9046 -- checks that must be applied to such conversions to prevent
9047 -- out-of-scope references.
9050 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9052 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9053 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9055 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9057 if Type_Access_Level (Target_Type) <
9058 Type_Access_Level (Opnd_Type)
9060 if In_Instance_Body then
9061 Error_Msg_N ("?source array type " &
9062 "has deeper accessibility level than target", Operand);
9063 Error_Msg_N ("\?Program_Error will be raised at run time",
9066 Make_Raise_Program_Error (Sloc (N),
9067 Reason => PE_Accessibility_Check_Failed));
9068 Set_Etype (N, Target_Type);
9071 -- Conversion not allowed because of accessibility levels
9074 Error_Msg_N ("source array type " &
9075 "has deeper accessibility level than target", Operand);
9082 -- All other cases where component base types do not match
9086 ("incompatible component types for array conversion",
9091 -- Check that component subtypes statically match. For numeric
9092 -- types this means that both must be either constrained or
9093 -- unconstrained. For enumeration types the bounds must match.
9094 -- All of this is checked in Subtypes_Statically_Match.
9096 if not Subtypes_Statically_Match
9097 (Target_Comp_Type, Opnd_Comp_Type)
9100 ("component subtypes must statically match", Operand);
9106 end Valid_Array_Conversion;
9108 -----------------------------
9109 -- Valid_Tagged_Conversion --
9110 -----------------------------
9112 function Valid_Tagged_Conversion
9113 (Target_Type : Entity_Id;
9114 Opnd_Type : Entity_Id) return Boolean
9117 -- Upward conversions are allowed (RM 4.6(22))
9119 if Covers (Target_Type, Opnd_Type)
9120 or else Is_Ancestor (Target_Type, Opnd_Type)
9124 -- Downward conversion are allowed if the operand is class-wide
9127 elsif Is_Class_Wide_Type (Opnd_Type)
9128 and then Covers (Opnd_Type, Target_Type)
9132 elsif Covers (Opnd_Type, Target_Type)
9133 or else Is_Ancestor (Opnd_Type, Target_Type)
9136 Conversion_Check (False,
9137 "downward conversion of tagged objects not allowed");
9139 -- Ada 2005 (AI-251): The conversion to/from interface types is
9142 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9145 -- If the operand is a class-wide type obtained through a limited_
9146 -- with clause, and the context includes the non-limited view, use
9147 -- it to determine whether the conversion is legal.
9149 elsif Is_Class_Wide_Type (Opnd_Type)
9150 and then From_With_Type (Opnd_Type)
9151 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9152 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9156 elsif Is_Access_Type (Opnd_Type)
9157 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9163 ("invalid tagged conversion, not compatible with}",
9164 N, First_Subtype (Opnd_Type));
9167 end Valid_Tagged_Conversion;
9169 -- Start of processing for Valid_Conversion
9172 Check_Parameterless_Call (Operand);
9174 if Is_Overloaded (Operand) then
9183 -- Remove procedure calls, which syntactically cannot appear
9184 -- in this context, but which cannot be removed by type checking,
9185 -- because the context does not impose a type.
9187 -- When compiling for VMS, spurious ambiguities can be produced
9188 -- when arithmetic operations have a literal operand and return
9189 -- System.Address or a descendant of it. These ambiguities are
9190 -- otherwise resolved by the context, but for conversions there
9191 -- is no context type and the removal of the spurious operations
9192 -- must be done explicitly here.
9194 -- The node may be labelled overloaded, but still contain only
9195 -- one interpretation because others were discarded in previous
9196 -- filters. If this is the case, retain the single interpretation
9199 Get_First_Interp (Operand, I, It);
9200 Opnd_Type := It.Typ;
9201 Get_Next_Interp (I, It);
9204 and then Opnd_Type /= Standard_Void_Type
9206 -- More than one candidate interpretation is available
9208 Get_First_Interp (Operand, I, It);
9209 while Present (It.Typ) loop
9210 if It.Typ = Standard_Void_Type then
9214 if Present (System_Aux_Id)
9215 and then Is_Descendent_Of_Address (It.Typ)
9220 Get_Next_Interp (I, It);
9224 Get_First_Interp (Operand, I, It);
9229 Error_Msg_N ("illegal operand in conversion", Operand);
9233 Get_Next_Interp (I, It);
9235 if Present (It.Typ) then
9237 It1 := Disambiguate (Operand, I1, I, Any_Type);
9239 if It1 = No_Interp then
9240 Error_Msg_N ("ambiguous operand in conversion", Operand);
9242 Error_Msg_Sloc := Sloc (It.Nam);
9243 Error_Msg_N ("\\possible interpretation#!", Operand);
9245 Error_Msg_Sloc := Sloc (N1);
9246 Error_Msg_N ("\\possible interpretation#!", Operand);
9252 Set_Etype (Operand, It1.Typ);
9253 Opnd_Type := It1.Typ;
9259 if Is_Numeric_Type (Target_Type) then
9261 -- A universal fixed expression can be converted to any numeric type
9263 if Opnd_Type = Universal_Fixed then
9266 -- Also no need to check when in an instance or inlined body, because
9267 -- the legality has been established when the template was analyzed.
9268 -- Furthermore, numeric conversions may occur where only a private
9269 -- view of the operand type is visible at the instantiation point.
9270 -- This results in a spurious error if we check that the operand type
9271 -- is a numeric type.
9273 -- Note: in a previous version of this unit, the following tests were
9274 -- applied only for generated code (Comes_From_Source set to False),
9275 -- but in fact the test is required for source code as well, since
9276 -- this situation can arise in source code.
9278 elsif In_Instance or else In_Inlined_Body then
9281 -- Otherwise we need the conversion check
9284 return Conversion_Check
9285 (Is_Numeric_Type (Opnd_Type),
9286 "illegal operand for numeric conversion");
9291 elsif Is_Array_Type (Target_Type) then
9292 if not Is_Array_Type (Opnd_Type)
9293 or else Opnd_Type = Any_Composite
9294 or else Opnd_Type = Any_String
9297 ("illegal operand for array conversion", Operand);
9300 return Valid_Array_Conversion;
9303 -- Ada 2005 (AI-251): Anonymous access types where target references an
9306 elsif (Ekind (Target_Type) = E_General_Access_Type
9308 Ekind (Target_Type) = E_Anonymous_Access_Type)
9309 and then Is_Interface (Directly_Designated_Type (Target_Type))
9311 -- Check the static accessibility rule of 4.6(17). Note that the
9312 -- check is not enforced when within an instance body, since the RM
9313 -- requires such cases to be caught at run time.
9315 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9316 if Type_Access_Level (Opnd_Type) >
9317 Type_Access_Level (Target_Type)
9319 -- In an instance, this is a run-time check, but one we know
9320 -- will fail, so generate an appropriate warning. The raise
9321 -- will be generated by Expand_N_Type_Conversion.
9323 if In_Instance_Body then
9325 ("?cannot convert local pointer to non-local access type",
9328 ("\?Program_Error will be raised at run time", Operand);
9331 ("cannot convert local pointer to non-local access type",
9336 -- Special accessibility checks are needed in the case of access
9337 -- discriminants declared for a limited type.
9339 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9340 and then not Is_Local_Anonymous_Access (Opnd_Type)
9342 -- When the operand is a selected access discriminant the check
9343 -- needs to be made against the level of the object denoted by
9344 -- the prefix of the selected name. (Object_Access_Level
9345 -- handles checking the prefix of the operand for this case.)
9347 if Nkind (Operand) = N_Selected_Component
9348 and then Object_Access_Level (Operand) >
9349 Type_Access_Level (Target_Type)
9351 -- In an instance, this is a run-time check, but one we
9352 -- know will fail, so generate an appropriate warning.
9353 -- The raise will be generated by Expand_N_Type_Conversion.
9355 if In_Instance_Body then
9357 ("?cannot convert access discriminant to non-local" &
9358 " access type", Operand);
9360 ("\?Program_Error will be raised at run time", Operand);
9363 ("cannot convert access discriminant to non-local" &
9364 " access type", Operand);
9369 -- The case of a reference to an access discriminant from
9370 -- within a limited type declaration (which will appear as
9371 -- a discriminal) is always illegal because the level of the
9372 -- discriminant is considered to be deeper than any (nameable)
9375 if Is_Entity_Name (Operand)
9376 and then not Is_Local_Anonymous_Access (Opnd_Type)
9377 and then (Ekind (Entity (Operand)) = E_In_Parameter
9378 or else Ekind (Entity (Operand)) = E_Constant)
9379 and then Present (Discriminal_Link (Entity (Operand)))
9382 ("discriminant has deeper accessibility level than target",
9391 -- General and anonymous access types
9393 elsif (Ekind (Target_Type) = E_General_Access_Type
9394 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9397 (Is_Access_Type (Opnd_Type)
9398 and then Ekind (Opnd_Type) /=
9399 E_Access_Subprogram_Type
9400 and then Ekind (Opnd_Type) /=
9401 E_Access_Protected_Subprogram_Type,
9402 "must be an access-to-object type")
9404 if Is_Access_Constant (Opnd_Type)
9405 and then not Is_Access_Constant (Target_Type)
9408 ("access-to-constant operand type not allowed", Operand);
9412 -- Check the static accessibility rule of 4.6(17). Note that the
9413 -- check is not enforced when within an instance body, since the RM
9414 -- requires such cases to be caught at run time.
9416 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9417 or else Is_Local_Anonymous_Access (Target_Type)
9419 if Type_Access_Level (Opnd_Type)
9420 > Type_Access_Level (Target_Type)
9422 -- In an instance, this is a run-time check, but one we
9423 -- know will fail, so generate an appropriate warning.
9424 -- The raise will be generated by Expand_N_Type_Conversion.
9426 if In_Instance_Body then
9428 ("?cannot convert local pointer to non-local access type",
9431 ("\?Program_Error will be raised at run time", Operand);
9434 -- Avoid generation of spurious error message
9436 if not Error_Posted (N) then
9438 ("cannot convert local pointer to non-local access type",
9445 -- Special accessibility checks are needed in the case of access
9446 -- discriminants declared for a limited type.
9448 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9449 and then not Is_Local_Anonymous_Access (Opnd_Type)
9452 -- When the operand is a selected access discriminant the check
9453 -- needs to be made against the level of the object denoted by
9454 -- the prefix of the selected name. (Object_Access_Level
9455 -- handles checking the prefix of the operand for this case.)
9457 if Nkind (Operand) = N_Selected_Component
9458 and then Object_Access_Level (Operand) >
9459 Type_Access_Level (Target_Type)
9461 -- In an instance, this is a run-time check, but one we
9462 -- know will fail, so generate an appropriate warning.
9463 -- The raise will be generated by Expand_N_Type_Conversion.
9465 if In_Instance_Body then
9467 ("?cannot convert access discriminant to non-local" &
9468 " access type", Operand);
9470 ("\?Program_Error will be raised at run time",
9475 ("cannot convert access discriminant to non-local" &
9476 " access type", Operand);
9481 -- The case of a reference to an access discriminant from
9482 -- within a limited type declaration (which will appear as
9483 -- a discriminal) is always illegal because the level of the
9484 -- discriminant is considered to be deeper than any (nameable)
9487 if Is_Entity_Name (Operand)
9488 and then (Ekind (Entity (Operand)) = E_In_Parameter
9489 or else Ekind (Entity (Operand)) = E_Constant)
9490 and then Present (Discriminal_Link (Entity (Operand)))
9493 ("discriminant has deeper accessibility level than target",
9501 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9502 -- Helper function to handle limited views
9504 --------------------------
9505 -- Full_Designated_Type --
9506 --------------------------
9508 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9509 Desig : constant Entity_Id := Designated_Type (T);
9511 if From_With_Type (Desig)
9512 and then Is_Incomplete_Type (Desig)
9513 and then Present (Non_Limited_View (Desig))
9515 return Non_Limited_View (Desig);
9519 end Full_Designated_Type;
9521 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9522 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9524 Same_Base : constant Boolean :=
9525 Base_Type (Target) = Base_Type (Opnd);
9528 if Is_Tagged_Type (Target) then
9529 return Valid_Tagged_Conversion (Target, Opnd);
9532 if not Same_Base then
9534 ("target designated type not compatible with }",
9535 N, Base_Type (Opnd));
9538 -- Ada 2005 AI-384: legality rule is symmetric in both
9539 -- designated types. The conversion is legal (with possible
9540 -- constraint check) if either designated type is
9543 elsif Subtypes_Statically_Match (Target, Opnd)
9545 (Has_Discriminants (Target)
9547 (not Is_Constrained (Opnd)
9548 or else not Is_Constrained (Target)))
9550 -- Special case, if Value_Size has been used to make the
9551 -- sizes different, the conversion is not allowed even
9552 -- though the subtypes statically match.
9554 if Known_Static_RM_Size (Target)
9555 and then Known_Static_RM_Size (Opnd)
9556 and then RM_Size (Target) /= RM_Size (Opnd)
9559 ("target designated subtype not compatible with }",
9562 ("\because sizes of the two designated subtypes differ",
9566 -- Normal case where conversion is allowed
9574 ("target designated subtype not compatible with }",
9581 -- Access to subprogram types. If the operand is an access parameter,
9582 -- the type has a deeper accessibility that any master, and cannot
9583 -- be assigned. We must make an exception if the conversion is part
9584 -- of an assignment and the target is the return object of an extended
9585 -- return statement, because in that case the accessibility check
9586 -- takes place after the return.
9588 elsif Is_Access_Subprogram_Type (Target_Type)
9589 and then No (Corresponding_Remote_Type (Opnd_Type))
9591 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9592 and then Is_Entity_Name (Operand)
9593 and then Ekind (Entity (Operand)) = E_In_Parameter
9595 (Nkind (Parent (N)) /= N_Assignment_Statement
9596 or else not Is_Entity_Name (Name (Parent (N)))
9597 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9600 ("illegal attempt to store anonymous access to subprogram",
9603 ("\value has deeper accessibility than any master " &
9608 ("\use named access type for& instead of access parameter",
9609 Operand, Entity (Operand));
9612 -- Check that the designated types are subtype conformant
9614 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9615 Old_Id => Designated_Type (Opnd_Type),
9618 -- Check the static accessibility rule of 4.6(20)
9620 if Type_Access_Level (Opnd_Type) >
9621 Type_Access_Level (Target_Type)
9624 ("operand type has deeper accessibility level than target",
9627 -- Check that if the operand type is declared in a generic body,
9628 -- then the target type must be declared within that same body
9629 -- (enforces last sentence of 4.6(20)).
9631 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9633 O_Gen : constant Node_Id :=
9634 Enclosing_Generic_Body (Opnd_Type);
9639 T_Gen := Enclosing_Generic_Body (Target_Type);
9640 while Present (T_Gen) and then T_Gen /= O_Gen loop
9641 T_Gen := Enclosing_Generic_Body (T_Gen);
9644 if T_Gen /= O_Gen then
9646 ("target type must be declared in same generic body"
9647 & " as operand type", N);
9654 -- Remote subprogram access types
9656 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9657 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9659 -- It is valid to convert from one RAS type to another provided
9660 -- that their specification statically match.
9662 Check_Subtype_Conformant
9664 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9666 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9671 -- If both are tagged types, check legality of view conversions
9673 elsif Is_Tagged_Type (Target_Type)
9674 and then Is_Tagged_Type (Opnd_Type)
9676 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9678 -- Types derived from the same root type are convertible
9680 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9683 -- In an instance or an inlined body, there may be inconsistent
9684 -- views of the same type, or of types derived from a common root.
9686 elsif (In_Instance or In_Inlined_Body)
9688 Root_Type (Underlying_Type (Target_Type)) =
9689 Root_Type (Underlying_Type (Opnd_Type))
9693 -- Special check for common access type error case
9695 elsif Ekind (Target_Type) = E_Access_Type
9696 and then Is_Access_Type (Opnd_Type)
9698 Error_Msg_N ("target type must be general access type!", N);
9699 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9704 Error_Msg_NE ("invalid conversion, not compatible with }",
9709 end Valid_Conversion;