1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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_Elim; use Sem_Elim;
64 with Sem_Elab; use Sem_Elab;
65 with Sem_Eval; use Sem_Eval;
66 with Sem_Intr; use Sem_Intr;
67 with Sem_Util; use Sem_Util;
68 with Sem_Type; use Sem_Type;
69 with Sem_Warn; use Sem_Warn;
70 with Sinfo; use Sinfo;
71 with Snames; use Snames;
72 with Stand; use Stand;
73 with Stringt; use Stringt;
74 with Style; use Style;
75 with Targparm; use Targparm;
76 with Tbuild; use Tbuild;
77 with Uintp; use Uintp;
78 with Urealp; use Urealp;
80 package body Sem_Res is
82 -----------------------
83 -- Local Subprograms --
84 -----------------------
86 -- Second pass (top-down) type checking and overload resolution procedures
87 -- Typ is the type required by context. These procedures propagate the
88 -- type information recursively to the descendants of N. If the node
89 -- is not overloaded, its Etype is established in the first pass. If
90 -- overloaded, the Resolve routines set the correct type. For arith.
91 -- operators, the Etype is the base type of the context.
93 -- Note that Resolve_Attribute is separated off in Sem_Attr
95 procedure Check_Discriminant_Use (N : Node_Id);
96 -- Enforce the restrictions on the use of discriminants when constraining
97 -- a component of a discriminated type (record or concurrent type).
99 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
100 -- Given a node for an operator associated with type T, check that
101 -- the operator is visible. Operators all of whose operands are
102 -- universal must be checked for visibility during resolution
103 -- because their type is not determinable based on their operands.
105 procedure Check_Fully_Declared_Prefix
108 -- Check that the type of the prefix of a dereference is not incomplete
110 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
111 -- Given a call node, N, which is known to occur immediately within the
112 -- subprogram being called, determines whether it is a detectable case of
113 -- an infinite recursion, and if so, outputs appropriate messages. Returns
114 -- True if an infinite recursion is detected, and False otherwise.
116 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
117 -- If the type of the object being initialized uses the secondary stack
118 -- directly or indirectly, create a transient scope for the call to the
119 -- init proc. This is because we do not create transient scopes for the
120 -- initialization of individual components within the init proc itself.
121 -- Could be optimized away perhaps?
123 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
124 -- Determine whether E is an access type declared by an access
125 -- declaration, and not an (anonymous) allocator type.
127 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
128 -- Utility to check whether the name in the call is a predefined
129 -- operator, in which case the call is made into an operator node.
130 -- An instance of an intrinsic conversion operation may be given
131 -- an operator name, but is not treated like an operator.
133 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
134 -- If a default expression in entry call N depends on the discriminants
135 -- of the task, it must be replaced with a reference to the discriminant
136 -- of the task being called.
138 procedure Resolve_Op_Concat_Arg
143 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
144 -- concatenation operator. The operand is either of the array type or of
145 -- the component type. If the operand is an aggregate, and the component
146 -- type is composite, this is ambiguous if component type has aggregates.
148 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
149 -- Does the first part of the work of Resolve_Op_Concat
151 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
152 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
153 -- has been resolved. See Resolve_Op_Concat for details.
155 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
156 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
157 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
158 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
159 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
164 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
165 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
166 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
188 function Operator_Kind
190 Is_Binary : Boolean) return Node_Kind;
191 -- Utility to map the name of an operator into the corresponding Node. Used
192 -- by other node rewriting procedures.
194 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
195 -- Resolve actuals of call, and add default expressions for missing ones.
196 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
197 -- called subprogram.
199 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
200 -- Called from Resolve_Call, when the prefix denotes an entry or element
201 -- of entry family. Actuals are resolved as for subprograms, and the node
202 -- is rebuilt as an entry call. Also called for protected operations. Typ
203 -- is the context type, which is used when the operation is a protected
204 -- function with no arguments, and the return value is indexed.
206 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
207 -- A call to a user-defined intrinsic operator is rewritten as a call
208 -- to the corresponding predefined operator, with suitable conversions.
210 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
211 -- Ditto, for unary operators (only arithmetic ones)
213 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
214 -- If an operator node resolves to a call to a user-defined operator,
215 -- rewrite the node as a function call.
217 procedure Make_Call_Into_Operator
221 -- Inverse transformation: if an operator is given in functional notation,
222 -- then after resolving the node, transform into an operator node, so
223 -- that operands are resolved properly. Recall that predefined operators
224 -- do not have a full signature and special resolution rules apply.
226 procedure Rewrite_Renamed_Operator
230 -- An operator can rename another, e.g. in an instantiation. In that
231 -- case, the proper operator node must be constructed and resolved.
233 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
234 -- The String_Literal_Subtype is built for all strings that are not
235 -- operands of a static concatenation operation. If the argument is
236 -- not a N_String_Literal node, then the call has no effect.
238 procedure Set_Slice_Subtype (N : Node_Id);
239 -- Build subtype of array type, with the range specified by the slice
241 procedure Simplify_Type_Conversion (N : Node_Id);
242 -- Called after N has been resolved and evaluated, but before range checks
243 -- have been applied. Currently simplifies a combination of floating-point
244 -- to integer conversion and Truncation attribute.
246 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
247 -- A universal_fixed expression in an universal context is unambiguous
248 -- if there is only one applicable fixed point type. Determining whether
249 -- there is only one requires a search over all visible entities, and
250 -- happens only in very pathological cases (see 6115-006).
252 function Valid_Conversion
255 Operand : Node_Id) return Boolean;
256 -- Verify legality rules given in 4.6 (8-23). Target is the target
257 -- type of the conversion, which may be an implicit conversion of
258 -- an actual parameter to an anonymous access type (in which case
259 -- N denotes the actual parameter and N = Operand).
261 -------------------------
262 -- Ambiguous_Character --
263 -------------------------
265 procedure Ambiguous_Character (C : Node_Id) is
269 if Nkind (C) = N_Character_Literal then
270 Error_Msg_N ("ambiguous character literal", C);
272 -- First the ones in Standard
275 ("\\possible interpretation: Character!", C);
277 ("\\possible interpretation: Wide_Character!", C);
279 -- Include Wide_Wide_Character in Ada 2005 mode
281 if Ada_Version >= Ada_05 then
283 ("\\possible interpretation: Wide_Wide_Character!", C);
286 -- Now any other types that match
288 E := Current_Entity (C);
289 while Present (E) loop
290 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
294 end Ambiguous_Character;
296 -------------------------
297 -- Analyze_And_Resolve --
298 -------------------------
300 procedure Analyze_And_Resolve (N : Node_Id) is
304 end Analyze_And_Resolve;
306 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
310 end Analyze_And_Resolve;
312 -- Version withs check(s) suppressed
314 procedure Analyze_And_Resolve
319 Scop : constant Entity_Id := Current_Scope;
322 if Suppress = All_Checks then
324 Svg : constant Suppress_Array := Scope_Suppress;
326 Scope_Suppress := (others => True);
327 Analyze_And_Resolve (N, Typ);
328 Scope_Suppress := Svg;
333 Svg : constant Boolean := Scope_Suppress (Suppress);
336 Scope_Suppress (Suppress) := True;
337 Analyze_And_Resolve (N, Typ);
338 Scope_Suppress (Suppress) := Svg;
342 if Current_Scope /= Scop
343 and then Scope_Is_Transient
345 -- This can only happen if a transient scope was created
346 -- for an inner expression, which will be removed upon
347 -- completion of the analysis of an enclosing construct.
348 -- The transient scope must have the suppress status of
349 -- the enclosing environment, not of this Analyze call.
351 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
354 end Analyze_And_Resolve;
356 procedure Analyze_And_Resolve
360 Scop : constant Entity_Id := Current_Scope;
363 if Suppress = All_Checks then
365 Svg : constant Suppress_Array := Scope_Suppress;
367 Scope_Suppress := (others => True);
368 Analyze_And_Resolve (N);
369 Scope_Suppress := Svg;
374 Svg : constant Boolean := Scope_Suppress (Suppress);
377 Scope_Suppress (Suppress) := True;
378 Analyze_And_Resolve (N);
379 Scope_Suppress (Suppress) := Svg;
383 if Current_Scope /= Scop
384 and then Scope_Is_Transient
386 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
389 end Analyze_And_Resolve;
391 ----------------------------
392 -- Check_Discriminant_Use --
393 ----------------------------
395 procedure Check_Discriminant_Use (N : Node_Id) is
396 PN : constant Node_Id := Parent (N);
397 Disc : constant Entity_Id := Entity (N);
402 -- Any use in a spec-expression is legal
404 if In_Spec_Expression then
407 elsif Nkind (PN) = N_Range then
409 -- Discriminant cannot be used to constrain a scalar type
413 if Nkind (P) = N_Range_Constraint
414 and then Nkind (Parent (P)) = N_Subtype_Indication
415 and then Nkind (Parent (Parent (P))) = N_Component_Definition
417 Error_Msg_N ("discriminant cannot constrain scalar type", N);
419 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
421 -- The following check catches the unusual case where
422 -- a discriminant appears within an index constraint
423 -- that is part of a larger expression within a constraint
424 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
425 -- For now we only check case of record components, and
426 -- note that a similar check should also apply in the
427 -- case of discriminant constraints below. ???
429 -- Note that the check for N_Subtype_Declaration below is to
430 -- detect the valid use of discriminants in the constraints of a
431 -- subtype declaration when this subtype declaration appears
432 -- inside the scope of a record type (which is syntactically
433 -- illegal, but which may be created as part of derived type
434 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
437 if Ekind (Current_Scope) = E_Record_Type
438 and then Scope (Disc) = Current_Scope
440 (Nkind (Parent (P)) = N_Subtype_Indication
442 Nkind_In (Parent (Parent (P)), N_Component_Definition,
443 N_Subtype_Declaration)
444 and then Paren_Count (N) = 0)
447 ("discriminant must appear alone in component constraint", N);
451 -- Detect a common error:
453 -- type R (D : Positive := 100) is record
454 -- Name : String (1 .. D);
457 -- The default value causes an object of type R to be allocated
458 -- with room for Positive'Last characters. The RM does not mandate
459 -- the allocation of the maximum size, but that is what GNAT does
460 -- so we should warn the programmer that there is a problem.
462 Check_Large : declare
468 function Large_Storage_Type (T : Entity_Id) return Boolean;
469 -- Return True if type T has a large enough range that
470 -- any array whose index type covered the whole range of
471 -- the type would likely raise Storage_Error.
473 ------------------------
474 -- Large_Storage_Type --
475 ------------------------
477 function Large_Storage_Type (T : Entity_Id) return Boolean is
479 -- The type is considered large if its bounds are known at
480 -- compile time and if it requires at least as many bits as
481 -- a Positive to store the possible values.
483 return Compile_Time_Known_Value (Type_Low_Bound (T))
484 and then Compile_Time_Known_Value (Type_High_Bound (T))
486 Minimum_Size (T, Biased => True) >=
487 RM_Size (Standard_Positive);
488 end Large_Storage_Type;
490 -- Start of processing for Check_Large
493 -- Check that the Disc has a large range
495 if not Large_Storage_Type (Etype (Disc)) then
499 -- If the enclosing type is limited, we allocate only the
500 -- default value, not the maximum, and there is no need for
503 if Is_Limited_Type (Scope (Disc)) then
507 -- Check that it is the high bound
509 if N /= High_Bound (PN)
510 or else No (Discriminant_Default_Value (Disc))
515 -- Check the array allows a large range at this bound.
516 -- First find the array
520 if Nkind (SI) /= N_Subtype_Indication then
524 T := Entity (Subtype_Mark (SI));
526 if not Is_Array_Type (T) then
530 -- Next, find the dimension
532 TB := First_Index (T);
533 CB := First (Constraints (P));
535 and then Present (TB)
536 and then Present (CB)
547 -- Now, check the dimension has a large range
549 if not Large_Storage_Type (Etype (TB)) then
553 -- Warn about the danger
556 ("?creation of & object may raise Storage_Error!",
565 -- Legal case is in index or discriminant constraint
567 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
568 N_Discriminant_Association)
570 if Paren_Count (N) > 0 then
572 ("discriminant in constraint must appear alone", N);
574 elsif Nkind (N) = N_Expanded_Name
575 and then Comes_From_Source (N)
578 ("discriminant must appear alone as a direct name", N);
583 -- Otherwise, context is an expression. It should not be within
584 -- (i.e. a subexpression of) a constraint for a component.
589 while not Nkind_In (P, N_Component_Declaration,
590 N_Subtype_Indication,
598 -- If the discriminant is used in an expression that is a bound
599 -- of a scalar type, an Itype is created and the bounds are attached
600 -- to its range, not to the original subtype indication. Such use
601 -- is of course a double fault.
603 if (Nkind (P) = N_Subtype_Indication
604 and then Nkind_In (Parent (P), N_Component_Definition,
605 N_Derived_Type_Definition)
606 and then D = Constraint (P))
608 -- The constraint itself may be given by a subtype indication,
609 -- rather than by a more common discrete range.
611 or else (Nkind (P) = N_Subtype_Indication
613 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
614 or else Nkind (P) = N_Entry_Declaration
615 or else Nkind (D) = N_Defining_Identifier
618 ("discriminant in constraint must appear alone", N);
621 end Check_Discriminant_Use;
623 --------------------------------
624 -- Check_For_Visible_Operator --
625 --------------------------------
627 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
629 if Is_Invisible_Operator (N, T) then
631 ("operator for} is not directly visible!", N, First_Subtype (T));
632 Error_Msg_N ("use clause would make operation legal!", N);
634 end Check_For_Visible_Operator;
636 ----------------------------------
637 -- Check_Fully_Declared_Prefix --
638 ----------------------------------
640 procedure Check_Fully_Declared_Prefix
645 -- Check that the designated type of the prefix of a dereference is
646 -- not an incomplete type. This cannot be done unconditionally, because
647 -- dereferences of private types are legal in default expressions. This
648 -- case is taken care of in Check_Fully_Declared, called below. There
649 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
651 -- This consideration also applies to similar checks for allocators,
652 -- qualified expressions, and type conversions.
654 -- An additional exception concerns other per-object expressions that
655 -- are not directly related to component declarations, in particular
656 -- representation pragmas for tasks. These will be per-object
657 -- expressions if they depend on discriminants or some global entity.
658 -- If the task has access discriminants, the designated type may be
659 -- incomplete at the point the expression is resolved. This resolution
660 -- takes place within the body of the initialization procedure, where
661 -- the discriminant is replaced by its discriminal.
663 if Is_Entity_Name (Pref)
664 and then Ekind (Entity (Pref)) = E_In_Parameter
668 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
669 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
670 -- Analyze_Object_Renaming, and Freeze_Entity.
672 elsif Ada_Version >= Ada_05
673 and then Is_Entity_Name (Pref)
674 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
676 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
680 Check_Fully_Declared (Typ, Parent (Pref));
682 end Check_Fully_Declared_Prefix;
684 ------------------------------
685 -- Check_Infinite_Recursion --
686 ------------------------------
688 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
692 function Same_Argument_List return Boolean;
693 -- Check whether list of actuals is identical to list of formals
694 -- of called function (which is also the enclosing scope).
696 ------------------------
697 -- Same_Argument_List --
698 ------------------------
700 function Same_Argument_List return Boolean is
706 if not Is_Entity_Name (Name (N)) then
709 Subp := Entity (Name (N));
712 F := First_Formal (Subp);
713 A := First_Actual (N);
714 while Present (F) and then Present (A) loop
715 if not Is_Entity_Name (A)
716 or else Entity (A) /= F
726 end Same_Argument_List;
728 -- Start of processing for Check_Infinite_Recursion
731 -- Special case, if this is a procedure call and is a call to the
732 -- current procedure with the same argument list, then this is for
733 -- sure an infinite recursion and we insert a call to raise SE.
735 if Is_List_Member (N)
736 and then List_Length (List_Containing (N)) = 1
737 and then Same_Argument_List
740 P : constant Node_Id := Parent (N);
742 if Nkind (P) = N_Handled_Sequence_Of_Statements
743 and then Nkind (Parent (P)) = N_Subprogram_Body
744 and then Is_Empty_List (Declarations (Parent (P)))
746 Error_Msg_N ("!?infinite recursion", N);
747 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
749 Make_Raise_Storage_Error (Sloc (N),
750 Reason => SE_Infinite_Recursion));
756 -- If not that special case, search up tree, quitting if we reach a
757 -- construct (e.g. a conditional) that tells us that this is not a
758 -- case for an infinite recursion warning.
764 -- If no parent, then we were not inside a subprogram, this can for
765 -- example happen when processing certain pragmas in a spec. Just
766 -- return False in this case.
772 -- Done if we get to subprogram body, this is definitely an infinite
773 -- recursion case if we did not find anything to stop us.
775 exit when Nkind (P) = N_Subprogram_Body;
777 -- If appearing in conditional, result is false
779 if Nkind_In (P, N_Or_Else,
786 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
787 and then C /= First (Statements (P))
789 -- If the call is the expression of a return statement and the
790 -- actuals are identical to the formals, it's worth a warning.
791 -- However, we skip this if there is an immediately preceding
792 -- raise statement, since the call is never executed.
794 -- Furthermore, this corresponds to a common idiom:
796 -- function F (L : Thing) return Boolean is
798 -- raise Program_Error;
802 -- for generating a stub function
804 if Nkind (Parent (N)) = N_Simple_Return_Statement
805 and then Same_Argument_List
807 exit when not Is_List_Member (Parent (N));
809 -- OK, return statement is in a statement list, look for raise
815 -- Skip past N_Freeze_Entity nodes generated by expansion
817 Nod := Prev (Parent (N));
819 and then Nkind (Nod) = N_Freeze_Entity
824 -- If no raise statement, give warning
826 exit when Nkind (Nod) /= N_Raise_Statement
828 (Nkind (Nod) not in N_Raise_xxx_Error
829 or else Present (Condition (Nod)));
840 Error_Msg_N ("!?possible infinite recursion", N);
841 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
844 end Check_Infinite_Recursion;
846 -------------------------------
847 -- Check_Initialization_Call --
848 -------------------------------
850 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
851 Typ : constant Entity_Id := Etype (First_Formal (Nam));
853 function Uses_SS (T : Entity_Id) return Boolean;
854 -- Check whether the creation of an object of the type will involve
855 -- use of the secondary stack. If T is a record type, this is true
856 -- if the expression for some component uses the secondary stack, e.g.
857 -- through a call to a function that returns an unconstrained value.
858 -- False if T is controlled, because cleanups occur elsewhere.
864 function Uses_SS (T : Entity_Id) return Boolean is
867 Full_Type : Entity_Id := Underlying_Type (T);
870 -- Normally we want to use the underlying type, but if it's not set
871 -- then continue with T.
873 if not Present (Full_Type) then
877 if Is_Controlled (Full_Type) then
880 elsif Is_Array_Type (Full_Type) then
881 return Uses_SS (Component_Type (Full_Type));
883 elsif Is_Record_Type (Full_Type) then
884 Comp := First_Component (Full_Type);
885 while Present (Comp) loop
886 if Ekind (Comp) = E_Component
887 and then Nkind (Parent (Comp)) = N_Component_Declaration
889 -- The expression for a dynamic component may be rewritten
890 -- as a dereference, so retrieve original node.
892 Expr := Original_Node (Expression (Parent (Comp)));
894 -- Return True if the expression is a call to a function
895 -- (including an attribute function such as Image) with
896 -- a result that requires a transient scope.
898 if (Nkind (Expr) = N_Function_Call
899 or else (Nkind (Expr) = N_Attribute_Reference
900 and then Present (Expressions (Expr))))
901 and then Requires_Transient_Scope (Etype (Expr))
905 elsif Uses_SS (Etype (Comp)) then
910 Next_Component (Comp);
920 -- Start of processing for Check_Initialization_Call
923 -- Establish a transient scope if the type needs it
925 if Uses_SS (Typ) then
926 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
928 end Check_Initialization_Call;
930 ------------------------------
931 -- Check_Parameterless_Call --
932 ------------------------------
934 procedure Check_Parameterless_Call (N : Node_Id) is
937 function Prefix_Is_Access_Subp return Boolean;
938 -- If the prefix is of an access_to_subprogram type, the node must be
939 -- rewritten as a call. Ditto if the prefix is overloaded and all its
940 -- interpretations are access to subprograms.
942 ---------------------------
943 -- Prefix_Is_Access_Subp --
944 ---------------------------
946 function Prefix_Is_Access_Subp return Boolean is
951 if not Is_Overloaded (N) then
953 Ekind (Etype (N)) = E_Subprogram_Type
954 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
956 Get_First_Interp (N, I, It);
957 while Present (It.Typ) loop
958 if Ekind (It.Typ) /= E_Subprogram_Type
959 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
964 Get_Next_Interp (I, It);
969 end Prefix_Is_Access_Subp;
971 -- Start of processing for Check_Parameterless_Call
974 -- Defend against junk stuff if errors already detected
976 if Total_Errors_Detected /= 0 then
977 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
979 elsif Nkind (N) in N_Has_Chars
980 and then Chars (N) in Error_Name_Or_No_Name
988 -- If the context expects a value, and the name is a procedure, this is
989 -- most likely a missing 'Access. Don't try to resolve the parameterless
990 -- call, error will be caught when the outer call is analyzed.
992 if Is_Entity_Name (N)
993 and then Ekind (Entity (N)) = E_Procedure
994 and then not Is_Overloaded (N)
996 Nkind_In (Parent (N), N_Parameter_Association,
998 N_Procedure_Call_Statement)
1003 -- Rewrite as call if overloadable entity that is (or could be, in the
1004 -- overloaded case) a function call. If we know for sure that the entity
1005 -- is an enumeration literal, we do not rewrite it.
1007 if (Is_Entity_Name (N)
1008 and then Is_Overloadable (Entity (N))
1009 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1010 or else Is_Overloaded (N)))
1012 -- Rewrite as call if it is an explicit deference of an expression of
1013 -- a subprogram access type, and the subprogram type is not that of a
1014 -- procedure or entry.
1017 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1019 -- Rewrite as call if it is a selected component which is a function,
1020 -- this is the case of a call to a protected function (which may be
1021 -- overloaded with other protected operations).
1024 (Nkind (N) = N_Selected_Component
1025 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1027 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1029 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1030 and then Is_Overloaded (Selector_Name (N)))))
1032 -- If one of the above three conditions is met, rewrite as call.
1033 -- Apply the rewriting only once.
1036 if Nkind (Parent (N)) /= N_Function_Call
1037 or else N /= Name (Parent (N))
1039 Nam := New_Copy (N);
1041 -- If overloaded, overload set belongs to new copy
1043 Save_Interps (N, Nam);
1045 -- Change node to parameterless function call (note that the
1046 -- Parameter_Associations associations field is left set to Empty,
1047 -- its normal default value since there are no parameters)
1049 Change_Node (N, N_Function_Call);
1051 Set_Sloc (N, Sloc (Nam));
1055 elsif Nkind (N) = N_Parameter_Association then
1056 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1058 end Check_Parameterless_Call;
1060 -----------------------------
1061 -- Is_Definite_Access_Type --
1062 -----------------------------
1064 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1065 Btyp : constant Entity_Id := Base_Type (E);
1067 return Ekind (Btyp) = E_Access_Type
1068 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1069 and then Comes_From_Source (Btyp));
1070 end Is_Definite_Access_Type;
1072 ----------------------
1073 -- Is_Predefined_Op --
1074 ----------------------
1076 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1078 return Is_Intrinsic_Subprogram (Nam)
1079 and then not Is_Generic_Instance (Nam)
1080 and then Chars (Nam) in Any_Operator_Name
1081 and then (No (Alias (Nam))
1082 or else Is_Predefined_Op (Alias (Nam)));
1083 end Is_Predefined_Op;
1085 -----------------------------
1086 -- Make_Call_Into_Operator --
1087 -----------------------------
1089 procedure Make_Call_Into_Operator
1094 Op_Name : constant Name_Id := Chars (Op_Id);
1095 Act1 : Node_Id := First_Actual (N);
1096 Act2 : Node_Id := Next_Actual (Act1);
1097 Error : Boolean := False;
1098 Func : constant Entity_Id := Entity (Name (N));
1099 Is_Binary : constant Boolean := Present (Act2);
1101 Opnd_Type : Entity_Id;
1102 Orig_Type : Entity_Id := Empty;
1105 type Kind_Test is access function (E : Entity_Id) return Boolean;
1107 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1108 -- If the operand is not universal, and the operator is given by a
1109 -- expanded name, verify that the operand has an interpretation with
1110 -- a type defined in the given scope of the operator.
1112 function Type_In_P (Test : Kind_Test) return Entity_Id;
1113 -- Find a type of the given class in the package Pack that contains
1116 ---------------------------
1117 -- Operand_Type_In_Scope --
1118 ---------------------------
1120 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1121 Nod : constant Node_Id := Right_Opnd (Op_Node);
1126 if not Is_Overloaded (Nod) then
1127 return Scope (Base_Type (Etype (Nod))) = S;
1130 Get_First_Interp (Nod, I, It);
1131 while Present (It.Typ) loop
1132 if Scope (Base_Type (It.Typ)) = S then
1136 Get_Next_Interp (I, It);
1141 end Operand_Type_In_Scope;
1147 function Type_In_P (Test : Kind_Test) return Entity_Id is
1150 function In_Decl return Boolean;
1151 -- Verify that node is not part of the type declaration for the
1152 -- candidate type, which would otherwise be invisible.
1158 function In_Decl return Boolean is
1159 Decl_Node : constant Node_Id := Parent (E);
1165 if Etype (E) = Any_Type then
1168 elsif No (Decl_Node) then
1173 and then Nkind (N2) /= N_Compilation_Unit
1175 if N2 = Decl_Node then
1186 -- Start of processing for Type_In_P
1189 -- If the context type is declared in the prefix package, this
1190 -- is the desired base type.
1192 if Scope (Base_Type (Typ)) = Pack
1195 return Base_Type (Typ);
1198 E := First_Entity (Pack);
1199 while Present (E) loop
1201 and then not In_Decl
1213 -- Start of processing for Make_Call_Into_Operator
1216 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1221 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1222 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1223 Save_Interps (Act1, Left_Opnd (Op_Node));
1224 Save_Interps (Act2, Right_Opnd (Op_Node));
1225 Act1 := Left_Opnd (Op_Node);
1226 Act2 := Right_Opnd (Op_Node);
1231 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1232 Save_Interps (Act1, Right_Opnd (Op_Node));
1233 Act1 := Right_Opnd (Op_Node);
1236 -- If the operator is denoted by an expanded name, and the prefix is
1237 -- not Standard, but the operator is a predefined one whose scope is
1238 -- Standard, then this is an implicit_operator, inserted as an
1239 -- interpretation by the procedure of the same name. This procedure
1240 -- overestimates the presence of implicit operators, because it does
1241 -- not examine the type of the operands. Verify now that the operand
1242 -- type appears in the given scope. If right operand is universal,
1243 -- check the other operand. In the case of concatenation, either
1244 -- argument can be the component type, so check the type of the result.
1245 -- If both arguments are literals, look for a type of the right kind
1246 -- defined in the given scope. This elaborate nonsense is brought to
1247 -- you courtesy of b33302a. The type itself must be frozen, so we must
1248 -- find the type of the proper class in the given scope.
1250 -- A final wrinkle is the multiplication operator for fixed point
1251 -- types, which is defined in Standard only, and not in the scope of
1252 -- the fixed_point type itself.
1254 if Nkind (Name (N)) = N_Expanded_Name then
1255 Pack := Entity (Prefix (Name (N)));
1257 -- If the entity being called is defined in the given package,
1258 -- it is a renaming of a predefined operator, and known to be
1261 if Scope (Entity (Name (N))) = Pack
1262 and then Pack /= Standard_Standard
1266 -- Visibility does not need to be checked in an instance: if the
1267 -- operator was not visible in the generic it has been diagnosed
1268 -- already, else there is an implicit copy of it in the instance.
1270 elsif In_Instance then
1273 elsif (Op_Name = Name_Op_Multiply
1274 or else Op_Name = Name_Op_Divide)
1275 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1276 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1278 if Pack /= Standard_Standard then
1282 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1285 elsif Ada_Version >= Ada_05
1286 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1287 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1292 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1294 if Op_Name = Name_Op_Concat then
1295 Opnd_Type := Base_Type (Typ);
1297 elsif (Scope (Opnd_Type) = Standard_Standard
1299 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1301 and then not Comes_From_Source (Opnd_Type))
1303 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1306 if Scope (Opnd_Type) = Standard_Standard then
1308 -- Verify that the scope contains a type that corresponds to
1309 -- the given literal. Optimize the case where Pack is Standard.
1311 if Pack /= Standard_Standard then
1313 if Opnd_Type = Universal_Integer then
1314 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1316 elsif Opnd_Type = Universal_Real then
1317 Orig_Type := Type_In_P (Is_Real_Type'Access);
1319 elsif Opnd_Type = Any_String then
1320 Orig_Type := Type_In_P (Is_String_Type'Access);
1322 elsif Opnd_Type = Any_Access then
1323 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1325 elsif Opnd_Type = Any_Composite then
1326 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1328 if Present (Orig_Type) then
1329 if Has_Private_Component (Orig_Type) then
1332 Set_Etype (Act1, Orig_Type);
1335 Set_Etype (Act2, Orig_Type);
1344 Error := No (Orig_Type);
1347 elsif Ekind (Opnd_Type) = E_Allocator_Type
1348 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1352 -- If the type is defined elsewhere, and the operator is not
1353 -- defined in the given scope (by a renaming declaration, e.g.)
1354 -- then this is an error as well. If an extension of System is
1355 -- present, and the type may be defined there, Pack must be
1358 elsif Scope (Opnd_Type) /= Pack
1359 and then Scope (Op_Id) /= Pack
1360 and then (No (System_Aux_Id)
1361 or else Scope (Opnd_Type) /= System_Aux_Id
1362 or else Pack /= Scope (System_Aux_Id))
1364 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1367 Error := not Operand_Type_In_Scope (Pack);
1370 elsif Pack = Standard_Standard
1371 and then not Operand_Type_In_Scope (Standard_Standard)
1378 Error_Msg_Node_2 := Pack;
1380 ("& not declared in&", N, Selector_Name (Name (N)));
1381 Set_Etype (N, Any_Type);
1386 Set_Chars (Op_Node, Op_Name);
1388 if not Is_Private_Type (Etype (N)) then
1389 Set_Etype (Op_Node, Base_Type (Etype (N)));
1391 Set_Etype (Op_Node, Etype (N));
1394 -- If this is a call to a function that renames a predefined equality,
1395 -- the renaming declaration provides a type that must be used to
1396 -- resolve the operands. This must be done now because resolution of
1397 -- the equality node will not resolve any remaining ambiguity, and it
1398 -- assumes that the first operand is not overloaded.
1400 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1401 and then Ekind (Func) = E_Function
1402 and then Is_Overloaded (Act1)
1404 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1405 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1408 Set_Entity (Op_Node, Op_Id);
1409 Generate_Reference (Op_Id, N, ' ');
1411 -- Do rewrite setting Comes_From_Source on the result if the original
1412 -- call came from source. Although it is not strictly the case that the
1413 -- operator as such comes from the source, logically it corresponds
1414 -- exactly to the function call in the source, so it should be marked
1415 -- this way (e.g. to make sure that validity checks work fine).
1418 CS : constant Boolean := Comes_From_Source (N);
1420 Rewrite (N, Op_Node);
1421 Set_Comes_From_Source (N, CS);
1424 -- If this is an arithmetic operator and the result type is private,
1425 -- the operands and the result must be wrapped in conversion to
1426 -- expose the underlying numeric type and expand the proper checks,
1427 -- e.g. on division.
1429 if Is_Private_Type (Typ) then
1431 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1432 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1433 Resolve_Intrinsic_Operator (N, Typ);
1435 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1436 Resolve_Intrinsic_Unary_Operator (N, Typ);
1445 -- For predefined operators on literals, the operation freezes
1448 if Present (Orig_Type) then
1449 Set_Etype (Act1, Orig_Type);
1450 Freeze_Expression (Act1);
1452 end Make_Call_Into_Operator;
1458 function Operator_Kind
1460 Is_Binary : Boolean) return Node_Kind
1466 if Op_Name = Name_Op_And then
1468 elsif Op_Name = Name_Op_Or then
1470 elsif Op_Name = Name_Op_Xor then
1472 elsif Op_Name = Name_Op_Eq then
1474 elsif Op_Name = Name_Op_Ne then
1476 elsif Op_Name = Name_Op_Lt then
1478 elsif Op_Name = Name_Op_Le then
1480 elsif Op_Name = Name_Op_Gt then
1482 elsif Op_Name = Name_Op_Ge then
1484 elsif Op_Name = Name_Op_Add then
1486 elsif Op_Name = Name_Op_Subtract then
1487 Kind := N_Op_Subtract;
1488 elsif Op_Name = Name_Op_Concat then
1489 Kind := N_Op_Concat;
1490 elsif Op_Name = Name_Op_Multiply then
1491 Kind := N_Op_Multiply;
1492 elsif Op_Name = Name_Op_Divide then
1493 Kind := N_Op_Divide;
1494 elsif Op_Name = Name_Op_Mod then
1496 elsif Op_Name = Name_Op_Rem then
1498 elsif Op_Name = Name_Op_Expon then
1501 raise Program_Error;
1507 if Op_Name = Name_Op_Add then
1509 elsif Op_Name = Name_Op_Subtract then
1511 elsif Op_Name = Name_Op_Abs then
1513 elsif Op_Name = Name_Op_Not then
1516 raise Program_Error;
1523 ----------------------------
1524 -- Preanalyze_And_Resolve --
1525 ----------------------------
1527 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1528 Save_Full_Analysis : constant Boolean := Full_Analysis;
1531 Full_Analysis := False;
1532 Expander_Mode_Save_And_Set (False);
1534 -- We suppress all checks for this analysis, since the checks will
1535 -- be applied properly, and in the right location, when the default
1536 -- expression is reanalyzed and reexpanded later on.
1538 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1540 Expander_Mode_Restore;
1541 Full_Analysis := Save_Full_Analysis;
1542 end Preanalyze_And_Resolve;
1544 -- Version without context type
1546 procedure Preanalyze_And_Resolve (N : Node_Id) is
1547 Save_Full_Analysis : constant Boolean := Full_Analysis;
1550 Full_Analysis := False;
1551 Expander_Mode_Save_And_Set (False);
1554 Resolve (N, Etype (N), Suppress => All_Checks);
1556 Expander_Mode_Restore;
1557 Full_Analysis := Save_Full_Analysis;
1558 end Preanalyze_And_Resolve;
1560 ----------------------------------
1561 -- Replace_Actual_Discriminants --
1562 ----------------------------------
1564 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1565 Loc : constant Source_Ptr := Sloc (N);
1566 Tsk : Node_Id := Empty;
1568 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1574 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1578 if Nkind (Nod) = N_Identifier then
1579 Ent := Entity (Nod);
1582 and then Ekind (Ent) = E_Discriminant
1585 Make_Selected_Component (Loc,
1586 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1587 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1589 Set_Etype (Nod, Etype (Ent));
1597 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1599 -- Start of processing for Replace_Actual_Discriminants
1602 if not Expander_Active then
1606 if Nkind (Name (N)) = N_Selected_Component then
1607 Tsk := Prefix (Name (N));
1609 elsif Nkind (Name (N)) = N_Indexed_Component then
1610 Tsk := Prefix (Prefix (Name (N)));
1616 Replace_Discrs (Default);
1618 end Replace_Actual_Discriminants;
1624 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1625 Ambiguous : Boolean := False;
1626 Ctx_Type : Entity_Id := Typ;
1627 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1628 Err_Type : Entity_Id := Empty;
1629 Found : Boolean := False;
1632 I1 : Interp_Index := 0; -- prevent junk warning
1635 Seen : Entity_Id := Empty; -- prevent junk warning
1637 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1638 -- Determine whether a node comes from a predefined library unit or
1641 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1642 -- Try and fix up a literal so that it matches its expected type. New
1643 -- literals are manufactured if necessary to avoid cascaded errors.
1645 procedure Resolution_Failed;
1646 -- Called when attempt at resolving current expression fails
1648 ------------------------------------
1649 -- Comes_From_Predefined_Lib_Unit --
1650 -------------------------------------
1652 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1655 Sloc (Nod) = Standard_Location
1656 or else Is_Predefined_File_Name (Unit_File_Name (
1657 Get_Source_Unit (Sloc (Nod))));
1658 end Comes_From_Predefined_Lib_Unit;
1660 --------------------
1661 -- Patch_Up_Value --
1662 --------------------
1664 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1666 if Nkind (N) = N_Integer_Literal
1667 and then Is_Real_Type (Typ)
1670 Make_Real_Literal (Sloc (N),
1671 Realval => UR_From_Uint (Intval (N))));
1672 Set_Etype (N, Universal_Real);
1673 Set_Is_Static_Expression (N);
1675 elsif Nkind (N) = N_Real_Literal
1676 and then Is_Integer_Type (Typ)
1679 Make_Integer_Literal (Sloc (N),
1680 Intval => UR_To_Uint (Realval (N))));
1681 Set_Etype (N, Universal_Integer);
1682 Set_Is_Static_Expression (N);
1684 elsif Nkind (N) = N_String_Literal
1685 and then Is_Character_Type (Typ)
1687 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1689 Make_Character_Literal (Sloc (N),
1691 Char_Literal_Value =>
1692 UI_From_Int (Character'Pos ('A'))));
1693 Set_Etype (N, Any_Character);
1694 Set_Is_Static_Expression (N);
1696 elsif Nkind (N) /= N_String_Literal
1697 and then Is_String_Type (Typ)
1700 Make_String_Literal (Sloc (N),
1701 Strval => End_String));
1703 elsif Nkind (N) = N_Range then
1704 Patch_Up_Value (Low_Bound (N), Typ);
1705 Patch_Up_Value (High_Bound (N), Typ);
1709 -----------------------
1710 -- Resolution_Failed --
1711 -----------------------
1713 procedure Resolution_Failed is
1715 Patch_Up_Value (N, Typ);
1717 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1718 Set_Is_Overloaded (N, False);
1720 -- The caller will return without calling the expander, so we need
1721 -- to set the analyzed flag. Note that it is fine to set Analyzed
1722 -- to True even if we are in the middle of a shallow analysis,
1723 -- (see the spec of sem for more details) since this is an error
1724 -- situation anyway, and there is no point in repeating the
1725 -- analysis later (indeed it won't work to repeat it later, since
1726 -- we haven't got a clear resolution of which entity is being
1729 Set_Analyzed (N, True);
1731 end Resolution_Failed;
1733 -- Start of processing for Resolve
1740 -- Access attribute on remote subprogram cannot be used for
1741 -- a non-remote access-to-subprogram type.
1743 if Nkind (N) = N_Attribute_Reference
1744 and then (Attribute_Name (N) = Name_Access
1745 or else Attribute_Name (N) = Name_Unrestricted_Access
1746 or else Attribute_Name (N) = Name_Unchecked_Access)
1747 and then Comes_From_Source (N)
1748 and then Is_Entity_Name (Prefix (N))
1749 and then Is_Subprogram (Entity (Prefix (N)))
1750 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1751 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1754 ("prefix must statically denote a non-remote subprogram", N);
1757 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1759 -- If the context is a Remote_Access_To_Subprogram, access attributes
1760 -- must be resolved with the corresponding fat pointer. There is no need
1761 -- to check for the attribute name since the return type of an
1762 -- attribute is never a remote type.
1764 if Nkind (N) = N_Attribute_Reference
1765 and then Comes_From_Source (N)
1766 and then (Is_Remote_Call_Interface (Typ)
1767 or else Is_Remote_Types (Typ))
1770 Attr : constant Attribute_Id :=
1771 Get_Attribute_Id (Attribute_Name (N));
1772 Pref : constant Node_Id := Prefix (N);
1775 Is_Remote : Boolean := True;
1778 -- Check that Typ is a remote access-to-subprogram type
1780 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1781 -- Prefix (N) must statically denote a remote subprogram
1782 -- declared in a package specification.
1784 if Attr = Attribute_Access then
1785 Decl := Unit_Declaration_Node (Entity (Pref));
1787 if Nkind (Decl) = N_Subprogram_Body then
1788 Spec := Corresponding_Spec (Decl);
1790 if not No (Spec) then
1791 Decl := Unit_Declaration_Node (Spec);
1795 Spec := Parent (Decl);
1797 if not Is_Entity_Name (Prefix (N))
1798 or else Nkind (Spec) /= N_Package_Specification
1800 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1804 ("prefix must statically denote a remote subprogram ",
1809 -- If we are generating code for a distributed program.
1810 -- perform semantic checks against the corresponding
1813 if (Attr = Attribute_Access
1814 or else Attr = Attribute_Unchecked_Access
1815 or else Attr = Attribute_Unrestricted_Access)
1816 and then Expander_Active
1817 and then Get_PCS_Name /= Name_No_DSA
1819 Check_Subtype_Conformant
1820 (New_Id => Entity (Prefix (N)),
1821 Old_Id => Designated_Type
1822 (Corresponding_Remote_Type (Typ)),
1826 Process_Remote_AST_Attribute (N, Typ);
1833 Debug_A_Entry ("resolving ", N);
1835 if Comes_From_Source (N) then
1836 if Is_Fixed_Point_Type (Typ) then
1837 Check_Restriction (No_Fixed_Point, N);
1839 elsif Is_Floating_Point_Type (Typ)
1840 and then Typ /= Universal_Real
1841 and then Typ /= Any_Real
1843 Check_Restriction (No_Floating_Point, N);
1847 -- Return if already analyzed
1849 if Analyzed (N) then
1850 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1853 -- Return if type = Any_Type (previous error encountered)
1855 elsif Etype (N) = Any_Type then
1856 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1860 Check_Parameterless_Call (N);
1862 -- If not overloaded, then we know the type, and all that needs doing
1863 -- is to check that this type is compatible with the context.
1865 if not Is_Overloaded (N) then
1866 Found := Covers (Typ, Etype (N));
1867 Expr_Type := Etype (N);
1869 -- In the overloaded case, we must select the interpretation that
1870 -- is compatible with the context (i.e. the type passed to Resolve)
1873 -- Loop through possible interpretations
1875 Get_First_Interp (N, I, It);
1876 Interp_Loop : while Present (It.Typ) loop
1878 -- We are only interested in interpretations that are compatible
1879 -- with the expected type, any other interpretations are ignored.
1881 if not Covers (Typ, It.Typ) then
1882 if Debug_Flag_V then
1883 Write_Str (" interpretation incompatible with context");
1888 -- Skip the current interpretation if it is disabled by an
1889 -- abstract operator. This action is performed only when the
1890 -- type against which we are resolving is the same as the
1891 -- type of the interpretation.
1893 if Ada_Version >= Ada_05
1894 and then It.Typ = Typ
1895 and then Typ /= Universal_Integer
1896 and then Typ /= Universal_Real
1897 and then Present (It.Abstract_Op)
1902 -- First matching interpretation
1908 Expr_Type := It.Typ;
1910 -- Matching interpretation that is not the first, maybe an
1911 -- error, but there are some cases where preference rules are
1912 -- used to choose between the two possibilities. These and
1913 -- some more obscure cases are handled in Disambiguate.
1916 -- If the current statement is part of a predefined library
1917 -- unit, then all interpretations which come from user level
1918 -- packages should not be considered.
1921 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1926 Error_Msg_Sloc := Sloc (Seen);
1927 It1 := Disambiguate (N, I1, I, Typ);
1929 -- Disambiguation has succeeded. Skip the remaining
1932 if It1 /= No_Interp then
1934 Expr_Type := It1.Typ;
1936 while Present (It.Typ) loop
1937 Get_Next_Interp (I, It);
1941 -- Before we issue an ambiguity complaint, check for
1942 -- the case of a subprogram call where at least one
1943 -- of the arguments is Any_Type, and if so, suppress
1944 -- the message, since it is a cascaded error.
1946 if Nkind_In (N, N_Function_Call,
1947 N_Procedure_Call_Statement)
1954 A := First_Actual (N);
1955 while Present (A) loop
1958 if Nkind (E) = N_Parameter_Association then
1959 E := Explicit_Actual_Parameter (E);
1962 if Etype (E) = Any_Type then
1963 if Debug_Flag_V then
1964 Write_Str ("Any_Type in call");
1975 elsif Nkind (N) in N_Binary_Op
1976 and then (Etype (Left_Opnd (N)) = Any_Type
1977 or else Etype (Right_Opnd (N)) = Any_Type)
1981 elsif Nkind (N) in N_Unary_Op
1982 and then Etype (Right_Opnd (N)) = Any_Type
1987 -- Not that special case, so issue message using the
1988 -- flag Ambiguous to control printing of the header
1989 -- message only at the start of an ambiguous set.
1991 if not Ambiguous then
1992 if Nkind (N) = N_Function_Call
1993 and then Nkind (Name (N)) = N_Explicit_Dereference
1996 ("ambiguous expression "
1997 & "(cannot resolve indirect call)!", N);
2000 ("ambiguous expression (cannot resolve&)!",
2006 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2008 ("\\possible interpretation (inherited)#!", N);
2010 Error_Msg_N ("\\possible interpretation#!", N);
2014 Error_Msg_Sloc := Sloc (It.Nam);
2016 -- By default, the error message refers to the candidate
2017 -- interpretation. But if it is a predefined operator, it
2018 -- is implicitly declared at the declaration of the type
2019 -- of the operand. Recover the sloc of that declaration
2020 -- for the error message.
2022 if Nkind (N) in N_Op
2023 and then Scope (It.Nam) = Standard_Standard
2024 and then not Is_Overloaded (Right_Opnd (N))
2025 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2028 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2030 if Comes_From_Source (Err_Type)
2031 and then Present (Parent (Err_Type))
2033 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2036 elsif Nkind (N) in N_Binary_Op
2037 and then Scope (It.Nam) = Standard_Standard
2038 and then not Is_Overloaded (Left_Opnd (N))
2039 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2042 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2044 if Comes_From_Source (Err_Type)
2045 and then Present (Parent (Err_Type))
2047 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2050 -- If this is an indirect call, use the subprogram_type
2051 -- in the message, to have a meaningful location.
2052 -- Indicate as well if this is an inherited operation,
2053 -- created by a type declaration.
2055 elsif Nkind (N) = N_Function_Call
2056 and then Nkind (Name (N)) = N_Explicit_Dereference
2057 and then Is_Type (It.Nam)
2061 Sloc (Associated_Node_For_Itype (Err_Type));
2066 if Nkind (N) in N_Op
2067 and then Scope (It.Nam) = Standard_Standard
2068 and then Present (Err_Type)
2070 -- Special-case the message for universal_fixed
2071 -- operators, which are not declared with the type
2072 -- of the operand, but appear forever in Standard.
2074 if It.Typ = Universal_Fixed
2075 and then Scope (It.Nam) = Standard_Standard
2078 ("\\possible interpretation as " &
2079 "universal_fixed operation " &
2080 "(RM 4.5.5 (19))", N);
2083 ("\\possible interpretation (predefined)#!", N);
2087 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2090 ("\\possible interpretation (inherited)#!", N);
2092 Error_Msg_N ("\\possible interpretation#!", N);
2098 -- We have a matching interpretation, Expr_Type is the type
2099 -- from this interpretation, and Seen is the entity.
2101 -- For an operator, just set the entity name. The type will be
2102 -- set by the specific operator resolution routine.
2104 if Nkind (N) in N_Op then
2105 Set_Entity (N, Seen);
2106 Generate_Reference (Seen, N);
2108 elsif Nkind (N) = N_Character_Literal then
2109 Set_Etype (N, Expr_Type);
2111 -- For an explicit dereference, attribute reference, range,
2112 -- short-circuit form (which is not an operator node), or call
2113 -- with a name that is an explicit dereference, there is
2114 -- nothing to be done at this point.
2116 elsif Nkind_In (N, N_Explicit_Dereference,
2117 N_Attribute_Reference,
2119 N_Indexed_Component,
2122 N_Selected_Component,
2124 or else Nkind (Name (N)) = N_Explicit_Dereference
2128 -- For procedure or function calls, set the type of the name,
2129 -- and also the entity pointer for the prefix
2131 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2132 and then (Is_Entity_Name (Name (N))
2133 or else Nkind (Name (N)) = N_Operator_Symbol)
2135 Set_Etype (Name (N), Expr_Type);
2136 Set_Entity (Name (N), Seen);
2137 Generate_Reference (Seen, Name (N));
2139 elsif Nkind (N) = N_Function_Call
2140 and then Nkind (Name (N)) = N_Selected_Component
2142 Set_Etype (Name (N), Expr_Type);
2143 Set_Entity (Selector_Name (Name (N)), Seen);
2144 Generate_Reference (Seen, Selector_Name (Name (N)));
2146 -- For all other cases, just set the type of the Name
2149 Set_Etype (Name (N), Expr_Type);
2156 -- Move to next interpretation
2158 exit Interp_Loop when No (It.Typ);
2160 Get_Next_Interp (I, It);
2161 end loop Interp_Loop;
2164 -- At this stage Found indicates whether or not an acceptable
2165 -- interpretation exists. If not, then we have an error, except
2166 -- that if the context is Any_Type as a result of some other error,
2167 -- then we suppress the error report.
2170 if Typ /= Any_Type then
2172 -- If type we are looking for is Void, then this is the procedure
2173 -- call case, and the error is simply that what we gave is not a
2174 -- procedure name (we think of procedure calls as expressions with
2175 -- types internally, but the user doesn't think of them this way!)
2177 if Typ = Standard_Void_Type then
2179 -- Special case message if function used as a procedure
2181 if Nkind (N) = N_Procedure_Call_Statement
2182 and then Is_Entity_Name (Name (N))
2183 and then Ekind (Entity (Name (N))) = E_Function
2186 ("cannot use function & in a procedure call",
2187 Name (N), Entity (Name (N)));
2189 -- Otherwise give general message (not clear what cases this
2190 -- covers, but no harm in providing for them!)
2193 Error_Msg_N ("expect procedure name in procedure call", N);
2198 -- Otherwise we do have a subexpression with the wrong type
2200 -- Check for the case of an allocator which uses an access type
2201 -- instead of the designated type. This is a common error and we
2202 -- specialize the message, posting an error on the operand of the
2203 -- allocator, complaining that we expected the designated type of
2206 elsif Nkind (N) = N_Allocator
2207 and then Ekind (Typ) in Access_Kind
2208 and then Ekind (Etype (N)) in Access_Kind
2209 and then Designated_Type (Etype (N)) = Typ
2211 Wrong_Type (Expression (N), Designated_Type (Typ));
2214 -- Check for view mismatch on Null in instances, for which the
2215 -- view-swapping mechanism has no identifier.
2217 elsif (In_Instance or else In_Inlined_Body)
2218 and then (Nkind (N) = N_Null)
2219 and then Is_Private_Type (Typ)
2220 and then Is_Access_Type (Full_View (Typ))
2222 Resolve (N, Full_View (Typ));
2226 -- Check for an aggregate. Sometimes we can get bogus aggregates
2227 -- from misuse of parentheses, and we are about to complain about
2228 -- the aggregate without even looking inside it.
2230 -- Instead, if we have an aggregate of type Any_Composite, then
2231 -- analyze and resolve the component fields, and then only issue
2232 -- another message if we get no errors doing this (otherwise
2233 -- assume that the errors in the aggregate caused the problem).
2235 elsif Nkind (N) = N_Aggregate
2236 and then Etype (N) = Any_Composite
2238 -- Disable expansion in any case. If there is a type mismatch
2239 -- it may be fatal to try to expand the aggregate. The flag
2240 -- would otherwise be set to false when the error is posted.
2242 Expander_Active := False;
2245 procedure Check_Aggr (Aggr : Node_Id);
2246 -- Check one aggregate, and set Found to True if we have a
2247 -- definite error in any of its elements
2249 procedure Check_Elmt (Aelmt : Node_Id);
2250 -- Check one element of aggregate and set Found to True if
2251 -- we definitely have an error in the element.
2257 procedure Check_Aggr (Aggr : Node_Id) is
2261 if Present (Expressions (Aggr)) then
2262 Elmt := First (Expressions (Aggr));
2263 while Present (Elmt) loop
2269 if Present (Component_Associations (Aggr)) then
2270 Elmt := First (Component_Associations (Aggr));
2271 while Present (Elmt) loop
2273 -- If this is a default-initialized component, then
2274 -- there is nothing to check. The box will be
2275 -- replaced by the appropriate call during late
2278 if not Box_Present (Elmt) then
2279 Check_Elmt (Expression (Elmt));
2291 procedure Check_Elmt (Aelmt : Node_Id) is
2293 -- If we have a nested aggregate, go inside it (to
2294 -- attempt a naked analyze-resolve of the aggregate
2295 -- can cause undesirable cascaded errors). Do not
2296 -- resolve expression if it needs a type from context,
2297 -- as for integer * fixed expression.
2299 if Nkind (Aelmt) = N_Aggregate then
2305 if not Is_Overloaded (Aelmt)
2306 and then Etype (Aelmt) /= Any_Fixed
2311 if Etype (Aelmt) = Any_Type then
2322 -- If an error message was issued already, Found got reset
2323 -- to True, so if it is still False, issue the standard
2324 -- Wrong_Type message.
2327 if Is_Overloaded (N)
2328 and then Nkind (N) = N_Function_Call
2331 Subp_Name : Node_Id;
2333 if Is_Entity_Name (Name (N)) then
2334 Subp_Name := Name (N);
2336 elsif Nkind (Name (N)) = N_Selected_Component then
2338 -- Protected operation: retrieve operation name
2340 Subp_Name := Selector_Name (Name (N));
2342 raise Program_Error;
2345 Error_Msg_Node_2 := Typ;
2346 Error_Msg_NE ("no visible interpretation of&" &
2347 " matches expected type&", N, Subp_Name);
2350 if All_Errors_Mode then
2352 Index : Interp_Index;
2356 Error_Msg_N ("\\possible interpretations:", N);
2358 Get_First_Interp (Name (N), Index, It);
2359 while Present (It.Nam) loop
2360 Error_Msg_Sloc := Sloc (It.Nam);
2361 Error_Msg_Node_2 := It.Nam;
2363 ("\\ type& for & declared#", N, It.Typ);
2364 Get_Next_Interp (Index, It);
2369 Error_Msg_N ("\use -gnatf for details", N);
2372 Wrong_Type (N, Typ);
2380 -- Test if we have more than one interpretation for the context
2382 elsif Ambiguous then
2386 -- Here we have an acceptable interpretation for the context
2389 -- Propagate type information and normalize tree for various
2390 -- predefined operations. If the context only imposes a class of
2391 -- types, rather than a specific type, propagate the actual type
2394 if Typ = Any_Integer
2395 or else Typ = Any_Boolean
2396 or else Typ = Any_Modular
2397 or else Typ = Any_Real
2398 or else Typ = Any_Discrete
2400 Ctx_Type := Expr_Type;
2402 -- Any_Fixed is legal in a real context only if a specific
2403 -- fixed point type is imposed. If Norman Cohen can be
2404 -- confused by this, it deserves a separate message.
2407 and then Expr_Type = Any_Fixed
2409 Error_Msg_N ("illegal context for mixed mode operation", N);
2410 Set_Etype (N, Universal_Real);
2411 Ctx_Type := Universal_Real;
2415 -- A user-defined operator is transformed into a function call at
2416 -- this point, so that further processing knows that operators are
2417 -- really operators (i.e. are predefined operators). User-defined
2418 -- operators that are intrinsic are just renamings of the predefined
2419 -- ones, and need not be turned into calls either, but if they rename
2420 -- a different operator, we must transform the node accordingly.
2421 -- Instantiations of Unchecked_Conversion are intrinsic but are
2422 -- treated as functions, even if given an operator designator.
2424 if Nkind (N) in N_Op
2425 and then Present (Entity (N))
2426 and then Ekind (Entity (N)) /= E_Operator
2429 if not Is_Predefined_Op (Entity (N)) then
2430 Rewrite_Operator_As_Call (N, Entity (N));
2432 elsif Present (Alias (Entity (N)))
2434 Nkind (Parent (Parent (Entity (N)))) =
2435 N_Subprogram_Renaming_Declaration
2437 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2439 -- If the node is rewritten, it will be fully resolved in
2440 -- Rewrite_Renamed_Operator.
2442 if Analyzed (N) then
2448 case N_Subexpr'(Nkind (N)) is
2450 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2452 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2454 when N_And_Then | N_Or_Else
2455 => Resolve_Short_Circuit (N, Ctx_Type);
2457 when N_Attribute_Reference
2458 => Resolve_Attribute (N, Ctx_Type);
2460 when N_Character_Literal
2461 => Resolve_Character_Literal (N, Ctx_Type);
2463 when N_Conditional_Expression
2464 => Resolve_Conditional_Expression (N, Ctx_Type);
2466 when N_Expanded_Name
2467 => Resolve_Entity_Name (N, Ctx_Type);
2469 when N_Extension_Aggregate
2470 => Resolve_Extension_Aggregate (N, Ctx_Type);
2472 when N_Explicit_Dereference
2473 => Resolve_Explicit_Dereference (N, Ctx_Type);
2475 when N_Function_Call
2476 => Resolve_Call (N, Ctx_Type);
2479 => Resolve_Entity_Name (N, Ctx_Type);
2481 when N_Indexed_Component
2482 => Resolve_Indexed_Component (N, Ctx_Type);
2484 when N_Integer_Literal
2485 => Resolve_Integer_Literal (N, Ctx_Type);
2487 when N_Membership_Test
2488 => Resolve_Membership_Op (N, Ctx_Type);
2490 when N_Null => Resolve_Null (N, Ctx_Type);
2492 when N_Op_And | N_Op_Or | N_Op_Xor
2493 => Resolve_Logical_Op (N, Ctx_Type);
2495 when N_Op_Eq | N_Op_Ne
2496 => Resolve_Equality_Op (N, Ctx_Type);
2498 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2499 => Resolve_Comparison_Op (N, Ctx_Type);
2501 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2503 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2504 N_Op_Divide | N_Op_Mod | N_Op_Rem
2506 => Resolve_Arithmetic_Op (N, Ctx_Type);
2508 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2510 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2512 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2513 => Resolve_Unary_Op (N, Ctx_Type);
2515 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2517 when N_Procedure_Call_Statement
2518 => Resolve_Call (N, Ctx_Type);
2520 when N_Operator_Symbol
2521 => Resolve_Operator_Symbol (N, Ctx_Type);
2523 when N_Qualified_Expression
2524 => Resolve_Qualified_Expression (N, Ctx_Type);
2526 when N_Raise_xxx_Error
2527 => Set_Etype (N, Ctx_Type);
2529 when N_Range => Resolve_Range (N, Ctx_Type);
2532 => Resolve_Real_Literal (N, Ctx_Type);
2534 when N_Reference => Resolve_Reference (N, Ctx_Type);
2536 when N_Selected_Component
2537 => Resolve_Selected_Component (N, Ctx_Type);
2539 when N_Slice => Resolve_Slice (N, Ctx_Type);
2541 when N_String_Literal
2542 => Resolve_String_Literal (N, Ctx_Type);
2544 when N_Subprogram_Info
2545 => Resolve_Subprogram_Info (N, Ctx_Type);
2547 when N_Type_Conversion
2548 => Resolve_Type_Conversion (N, Ctx_Type);
2550 when N_Unchecked_Expression =>
2551 Resolve_Unchecked_Expression (N, Ctx_Type);
2553 when N_Unchecked_Type_Conversion =>
2554 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2558 -- If the subexpression was replaced by a non-subexpression, then
2559 -- all we do is to expand it. The only legitimate case we know of
2560 -- is converting procedure call statement to entry call statements,
2561 -- but there may be others, so we are making this test general.
2563 if Nkind (N) not in N_Subexpr then
2564 Debug_A_Exit ("resolving ", N, " (done)");
2569 -- The expression is definitely NOT overloaded at this point, so
2570 -- we reset the Is_Overloaded flag to avoid any confusion when
2571 -- reanalyzing the node.
2573 Set_Is_Overloaded (N, False);
2575 -- Freeze expression type, entity if it is a name, and designated
2576 -- type if it is an allocator (RM 13.14(10,11,13)).
2578 -- Now that the resolution of the type of the node is complete,
2579 -- and we did not detect an error, we can expand this node. We
2580 -- skip the expand call if we are in a default expression, see
2581 -- section "Handling of Default Expressions" in Sem spec.
2583 Debug_A_Exit ("resolving ", N, " (done)");
2585 -- We unconditionally freeze the expression, even if we are in
2586 -- default expression mode (the Freeze_Expression routine tests
2587 -- this flag and only freezes static types if it is set).
2589 Freeze_Expression (N);
2591 -- Now we can do the expansion
2601 -- Version with check(s) suppressed
2603 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2605 if Suppress = All_Checks then
2607 Svg : constant Suppress_Array := Scope_Suppress;
2609 Scope_Suppress := (others => True);
2611 Scope_Suppress := Svg;
2616 Svg : constant Boolean := Scope_Suppress (Suppress);
2618 Scope_Suppress (Suppress) := True;
2620 Scope_Suppress (Suppress) := Svg;
2629 -- Version with implicit type
2631 procedure Resolve (N : Node_Id) is
2633 Resolve (N, Etype (N));
2636 ---------------------
2637 -- Resolve_Actuals --
2638 ---------------------
2640 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2641 Loc : constant Source_Ptr := Sloc (N);
2646 Prev : Node_Id := Empty;
2649 procedure Check_Argument_Order;
2650 -- Performs a check for the case where the actuals are all simple
2651 -- identifiers that correspond to the formal names, but in the wrong
2652 -- order, which is considered suspicious and cause for a warning.
2654 procedure Check_Prefixed_Call;
2655 -- If the original node is an overloaded call in prefix notation,
2656 -- insert an 'Access or a dereference as needed over the first actual.
2657 -- Try_Object_Operation has already verified that there is a valid
2658 -- interpretation, but the form of the actual can only be determined
2659 -- once the primitive operation is identified.
2661 procedure Insert_Default;
2662 -- If the actual is missing in a call, insert in the actuals list
2663 -- an instance of the default expression. The insertion is always
2664 -- a named association.
2666 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2667 -- Check whether T1 and T2, or their full views, are derived from a
2668 -- common type. Used to enforce the restrictions on array conversions
2671 --------------------------
2672 -- Check_Argument_Order --
2673 --------------------------
2675 procedure Check_Argument_Order is
2677 -- Nothing to do if no parameters, or original node is neither a
2678 -- function call nor a procedure call statement (happens in the
2679 -- operator-transformed-to-function call case), or the call does
2680 -- not come from source, or this warning is off.
2682 if not Warn_On_Parameter_Order
2684 No (Parameter_Associations (N))
2686 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2689 not Comes_From_Source (N)
2695 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2698 -- Nothing to do if only one parameter
2704 -- Here if at least two arguments
2707 Actuals : array (1 .. Nargs) of Node_Id;
2711 Wrong_Order : Boolean := False;
2712 -- Set True if an out of order case is found
2715 -- Collect identifier names of actuals, fail if any actual is
2716 -- not a simple identifier, and record max length of name.
2718 Actual := First (Parameter_Associations (N));
2719 for J in Actuals'Range loop
2720 if Nkind (Actual) /= N_Identifier then
2723 Actuals (J) := Actual;
2728 -- If we got this far, all actuals are identifiers and the list
2729 -- of their names is stored in the Actuals array.
2731 Formal := First_Formal (Nam);
2732 for J in Actuals'Range loop
2734 -- If we ran out of formals, that's odd, probably an error
2735 -- which will be detected elsewhere, but abandon the search.
2741 -- If name matches and is in order OK
2743 if Chars (Formal) = Chars (Actuals (J)) then
2747 -- If no match, see if it is elsewhere in list and if so
2748 -- flag potential wrong order if type is compatible.
2750 for K in Actuals'Range loop
2751 if Chars (Formal) = Chars (Actuals (K))
2753 Has_Compatible_Type (Actuals (K), Etype (Formal))
2755 Wrong_Order := True;
2765 <<Continue>> Next_Formal (Formal);
2768 -- If Formals left over, also probably an error, skip warning
2770 if Present (Formal) then
2774 -- Here we give the warning if something was out of order
2778 ("actuals for this call may be in wrong order?", N);
2782 end Check_Argument_Order;
2784 -------------------------
2785 -- Check_Prefixed_Call --
2786 -------------------------
2788 procedure Check_Prefixed_Call is
2789 Act : constant Node_Id := First_Actual (N);
2790 A_Type : constant Entity_Id := Etype (Act);
2791 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2792 Orig : constant Node_Id := Original_Node (N);
2796 -- Check whether the call is a prefixed call, with or without
2797 -- additional actuals.
2799 if Nkind (Orig) = N_Selected_Component
2801 (Nkind (Orig) = N_Indexed_Component
2802 and then Nkind (Prefix (Orig)) = N_Selected_Component
2803 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2804 and then Is_Entity_Name (Act)
2805 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2807 if Is_Access_Type (A_Type)
2808 and then not Is_Access_Type (F_Type)
2810 -- Introduce dereference on object in prefix
2813 Make_Explicit_Dereference (Sloc (Act),
2814 Prefix => Relocate_Node (Act));
2815 Rewrite (Act, New_A);
2818 elsif Is_Access_Type (F_Type)
2819 and then not Is_Access_Type (A_Type)
2821 -- Introduce an implicit 'Access in prefix
2823 if not Is_Aliased_View (Act) then
2825 ("object in prefixed call to& must be aliased"
2826 & " (RM-2005 4.3.1 (13))",
2831 Make_Attribute_Reference (Loc,
2832 Attribute_Name => Name_Access,
2833 Prefix => Relocate_Node (Act)));
2838 end Check_Prefixed_Call;
2840 --------------------
2841 -- Insert_Default --
2842 --------------------
2844 procedure Insert_Default is
2849 -- Missing argument in call, nothing to insert
2851 if No (Default_Value (F)) then
2855 -- Note that we do a full New_Copy_Tree, so that any associated
2856 -- Itypes are properly copied. This may not be needed any more,
2857 -- but it does no harm as a safety measure! Defaults of a generic
2858 -- formal may be out of bounds of the corresponding actual (see
2859 -- cc1311b) and an additional check may be required.
2864 New_Scope => Current_Scope,
2867 if Is_Concurrent_Type (Scope (Nam))
2868 and then Has_Discriminants (Scope (Nam))
2870 Replace_Actual_Discriminants (N, Actval);
2873 if Is_Overloadable (Nam)
2874 and then Present (Alias (Nam))
2876 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2877 and then not Is_Tagged_Type (Etype (F))
2879 -- If default is a real literal, do not introduce a
2880 -- conversion whose effect may depend on the run-time
2881 -- size of universal real.
2883 if Nkind (Actval) = N_Real_Literal then
2884 Set_Etype (Actval, Base_Type (Etype (F)));
2886 Actval := Unchecked_Convert_To (Etype (F), Actval);
2890 if Is_Scalar_Type (Etype (F)) then
2891 Enable_Range_Check (Actval);
2894 Set_Parent (Actval, N);
2896 -- Resolve aggregates with their base type, to avoid scope
2897 -- anomalies: the subtype was first built in the subprogram
2898 -- declaration, and the current call may be nested.
2900 if Nkind (Actval) = N_Aggregate
2901 and then Has_Discriminants (Etype (Actval))
2903 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2905 Analyze_And_Resolve (Actval, Etype (Actval));
2909 Set_Parent (Actval, N);
2911 -- See note above concerning aggregates
2913 if Nkind (Actval) = N_Aggregate
2914 and then Has_Discriminants (Etype (Actval))
2916 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2918 -- Resolve entities with their own type, which may differ
2919 -- from the type of a reference in a generic context (the
2920 -- view swapping mechanism did not anticipate the re-analysis
2921 -- of default values in calls).
2923 elsif Is_Entity_Name (Actval) then
2924 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2927 Analyze_And_Resolve (Actval, Etype (Actval));
2931 -- If default is a tag indeterminate function call, propagate
2932 -- tag to obtain proper dispatching.
2934 if Is_Controlling_Formal (F)
2935 and then Nkind (Default_Value (F)) = N_Function_Call
2937 Set_Is_Controlling_Actual (Actval);
2942 -- If the default expression raises constraint error, then just
2943 -- silently replace it with an N_Raise_Constraint_Error node,
2944 -- since we already gave the warning on the subprogram spec.
2946 if Raises_Constraint_Error (Actval) then
2948 Make_Raise_Constraint_Error (Loc,
2949 Reason => CE_Range_Check_Failed));
2950 Set_Raises_Constraint_Error (Actval);
2951 Set_Etype (Actval, Etype (F));
2955 Make_Parameter_Association (Loc,
2956 Explicit_Actual_Parameter => Actval,
2957 Selector_Name => Make_Identifier (Loc, Chars (F)));
2959 -- Case of insertion is first named actual
2961 if No (Prev) or else
2962 Nkind (Parent (Prev)) /= N_Parameter_Association
2964 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2965 Set_First_Named_Actual (N, Actval);
2968 if No (Parameter_Associations (N)) then
2969 Set_Parameter_Associations (N, New_List (Assoc));
2971 Append (Assoc, Parameter_Associations (N));
2975 Insert_After (Prev, Assoc);
2978 -- Case of insertion is not first named actual
2981 Set_Next_Named_Actual
2982 (Assoc, Next_Named_Actual (Parent (Prev)));
2983 Set_Next_Named_Actual (Parent (Prev), Actval);
2984 Append (Assoc, Parameter_Associations (N));
2987 Mark_Rewrite_Insertion (Assoc);
2988 Mark_Rewrite_Insertion (Actval);
2997 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2998 FT1 : Entity_Id := T1;
2999 FT2 : Entity_Id := T2;
3002 if Is_Private_Type (T1)
3003 and then Present (Full_View (T1))
3005 FT1 := Full_View (T1);
3008 if Is_Private_Type (T2)
3009 and then Present (Full_View (T2))
3011 FT2 := Full_View (T2);
3014 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3017 -- Start of processing for Resolve_Actuals
3020 Check_Argument_Order;
3022 if Present (First_Actual (N)) then
3023 Check_Prefixed_Call;
3026 A := First_Actual (N);
3027 F := First_Formal (Nam);
3028 while Present (F) loop
3029 if No (A) and then Needs_No_Actuals (Nam) then
3032 -- If we have an error in any actual or formal, indicated by
3033 -- a type of Any_Type, then abandon resolution attempt, and
3034 -- set result type to Any_Type.
3036 elsif (Present (A) and then Etype (A) = Any_Type)
3037 or else Etype (F) = Any_Type
3039 Set_Etype (N, Any_Type);
3043 -- Case where actual is present
3045 -- If the actual is an entity, generate a reference to it now. We
3046 -- do this before the actual is resolved, because a formal of some
3047 -- protected subprogram, or a task discriminant, will be rewritten
3048 -- during expansion, and the reference to the source entity may
3052 and then Is_Entity_Name (A)
3053 and then Comes_From_Source (N)
3055 Orig_A := Entity (A);
3057 if Present (Orig_A) then
3058 if Is_Formal (Orig_A)
3059 and then Ekind (F) /= E_In_Parameter
3061 Generate_Reference (Orig_A, A, 'm');
3062 elsif not Is_Overloaded (A) then
3063 Generate_Reference (Orig_A, A);
3069 and then (Nkind (Parent (A)) /= N_Parameter_Association
3071 Chars (Selector_Name (Parent (A))) = Chars (F))
3073 -- If style checking mode on, check match of formal name
3076 if Nkind (Parent (A)) = N_Parameter_Association then
3077 Check_Identifier (Selector_Name (Parent (A)), F);
3081 -- If the formal is Out or In_Out, do not resolve and expand the
3082 -- conversion, because it is subsequently expanded into explicit
3083 -- temporaries and assignments. However, the object of the
3084 -- conversion can be resolved. An exception is the case of tagged
3085 -- type conversion with a class-wide actual. In that case we want
3086 -- the tag check to occur and no temporary will be needed (no
3087 -- representation change can occur) and the parameter is passed by
3088 -- reference, so we go ahead and resolve the type conversion.
3089 -- Another exception is the case of reference to component or
3090 -- subcomponent of a bit-packed array, in which case we want to
3091 -- defer expansion to the point the in and out assignments are
3094 if Ekind (F) /= E_In_Parameter
3095 and then Nkind (A) = N_Type_Conversion
3096 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3098 if Ekind (F) = E_In_Out_Parameter
3099 and then Is_Array_Type (Etype (F))
3101 if Has_Aliased_Components (Etype (Expression (A)))
3102 /= Has_Aliased_Components (Etype (F))
3105 -- In a view conversion, the conversion must be legal in
3106 -- both directions, and thus both component types must be
3107 -- aliased, or neither (4.6 (8)).
3109 -- The additional rule 4.6 (24.9.2) seems unduly
3110 -- restrictive: the privacy requirement should not
3111 -- apply to generic types, and should be checked in
3112 -- an instance. ARG query is in order.
3115 ("both component types in a view conversion must be"
3116 & " aliased, or neither", A);
3119 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3121 if Is_By_Reference_Type (Etype (F))
3122 or else Is_By_Reference_Type (Etype (Expression (A)))
3125 ("view conversion between unrelated by reference " &
3126 "array types not allowed (\'A'I-00246)", A);
3129 Comp_Type : constant Entity_Id :=
3131 (Etype (Expression (A)));
3133 if Comes_From_Source (A)
3134 and then Ada_Version >= Ada_05
3136 ((Is_Private_Type (Comp_Type)
3137 and then not Is_Generic_Type (Comp_Type))
3138 or else Is_Tagged_Type (Comp_Type)
3139 or else Is_Volatile (Comp_Type))
3142 ("component type of a view conversion cannot"
3143 & " be private, tagged, or volatile"
3152 if (Conversion_OK (A)
3153 or else Valid_Conversion (A, Etype (A), Expression (A)))
3154 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3156 Resolve (Expression (A));
3159 -- If the actual is a function call that returns a limited
3160 -- unconstrained object that needs finalization, create a
3161 -- transient scope for it, so that it can receive the proper
3162 -- finalization list.
3164 elsif Nkind (A) = N_Function_Call
3165 and then Is_Limited_Record (Etype (F))
3166 and then not Is_Constrained (Etype (F))
3167 and then Expander_Active
3169 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3171 Establish_Transient_Scope (A, False);
3173 -- A small optimization: if one of the actuals is a concatenation
3174 -- create a block around a procedure call to recover stack space.
3175 -- This alleviates stack usage when several procedure calls in
3176 -- the same statement list use concatenation. We do not perform
3177 -- this wrapping for code statements, where the argument is a
3178 -- static string, and we want to preserve warnings involving
3179 -- sequences of such statements.
3181 elsif Nkind (A) = N_Op_Concat
3182 and then Nkind (N) = N_Procedure_Call_Statement
3183 and then Expander_Active
3185 not (Is_Intrinsic_Subprogram (Nam)
3186 and then Chars (Nam) = Name_Asm)
3188 Establish_Transient_Scope (A, False);
3189 Resolve (A, Etype (F));
3192 if Nkind (A) = N_Type_Conversion
3193 and then Is_Array_Type (Etype (F))
3194 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3196 (Is_Limited_Type (Etype (F))
3197 or else Is_Limited_Type (Etype (Expression (A))))
3200 ("conversion between unrelated limited array types " &
3201 "not allowed (\A\I-00246)", A);
3203 if Is_Limited_Type (Etype (F)) then
3204 Explain_Limited_Type (Etype (F), A);
3207 if Is_Limited_Type (Etype (Expression (A))) then
3208 Explain_Limited_Type (Etype (Expression (A)), A);
3212 -- (Ada 2005: AI-251): If the actual is an allocator whose
3213 -- directly designated type is a class-wide interface, we build
3214 -- an anonymous access type to use it as the type of the
3215 -- allocator. Later, when the subprogram call is expanded, if
3216 -- the interface has a secondary dispatch table the expander
3217 -- will add a type conversion to force the correct displacement
3220 if Nkind (A) = N_Allocator then
3222 DDT : constant Entity_Id :=
3223 Directly_Designated_Type (Base_Type (Etype (F)));
3225 New_Itype : Entity_Id;
3228 if Is_Class_Wide_Type (DDT)
3229 and then Is_Interface (DDT)
3231 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3232 Set_Etype (New_Itype, Etype (A));
3233 Set_Directly_Designated_Type (New_Itype,
3234 Directly_Designated_Type (Etype (A)));
3235 Set_Etype (A, New_Itype);
3238 -- Ada 2005, AI-162:If the actual is an allocator, the
3239 -- innermost enclosing statement is the master of the
3240 -- created object. This needs to be done with expansion
3241 -- enabled only, otherwise the transient scope will not
3242 -- be removed in the expansion of the wrapped construct.
3244 if (Is_Controlled (DDT) or else Has_Task (DDT))
3245 and then Expander_Active
3247 Establish_Transient_Scope (A, False);
3252 -- (Ada 2005): The call may be to a primitive operation of
3253 -- a tagged synchronized type, declared outside of the type.
3254 -- In this case the controlling actual must be converted to
3255 -- its corresponding record type, which is the formal type.
3256 -- The actual may be a subtype, either because of a constraint
3257 -- or because it is a generic actual, so use base type to
3258 -- locate concurrent type.
3260 A_Typ := Base_Type (Etype (A));
3261 F_Typ := Base_Type (Etype (F));
3264 Full_A_Typ : Entity_Id;
3267 if Present (Full_View (A_Typ)) then
3268 Full_A_Typ := Base_Type (Full_View (A_Typ));
3270 Full_A_Typ := A_Typ;
3273 -- Tagged synchronized type (case 1): the actual is a
3276 if Is_Concurrent_Type (A_Typ)
3277 and then Corresponding_Record_Type (A_Typ) = F_Typ
3280 Unchecked_Convert_To
3281 (Corresponding_Record_Type (A_Typ), A));
3282 Resolve (A, Etype (F));
3284 -- Tagged synchronized type (case 2): the formal is a
3287 elsif Ekind (Full_A_Typ) = E_Record_Type
3289 (Corresponding_Concurrent_Type (Full_A_Typ))
3290 and then Is_Concurrent_Type (F_Typ)
3291 and then Present (Corresponding_Record_Type (F_Typ))
3292 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3294 Resolve (A, Corresponding_Record_Type (F_Typ));
3299 Resolve (A, Etype (F));
3307 -- For mode IN, if actual is an entity, and the type of the formal
3308 -- has warnings suppressed, then we reset Never_Set_In_Source for
3309 -- the calling entity. The reason for this is to catch cases like
3310 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3311 -- uses trickery to modify an IN parameter.
3313 if Ekind (F) = E_In_Parameter
3314 and then Is_Entity_Name (A)
3315 and then Present (Entity (A))
3316 and then Ekind (Entity (A)) = E_Variable
3317 and then Has_Warnings_Off (F_Typ)
3319 Set_Never_Set_In_Source (Entity (A), False);
3322 -- Perform error checks for IN and IN OUT parameters
3324 if Ekind (F) /= E_Out_Parameter then
3326 -- Check unset reference. For scalar parameters, it is clearly
3327 -- wrong to pass an uninitialized value as either an IN or
3328 -- IN-OUT parameter. For composites, it is also clearly an
3329 -- error to pass a completely uninitialized value as an IN
3330 -- parameter, but the case of IN OUT is trickier. We prefer
3331 -- not to give a warning here. For example, suppose there is
3332 -- a routine that sets some component of a record to False.
3333 -- It is perfectly reasonable to make this IN-OUT and allow
3334 -- either initialized or uninitialized records to be passed
3337 -- For partially initialized composite values, we also avoid
3338 -- warnings, since it is quite likely that we are passing a
3339 -- partially initialized value and only the initialized fields
3340 -- will in fact be read in the subprogram.
3342 if Is_Scalar_Type (A_Typ)
3343 or else (Ekind (F) = E_In_Parameter
3344 and then not Is_Partially_Initialized_Type (A_Typ))
3346 Check_Unset_Reference (A);
3349 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3350 -- actual to a nested call, since this is case of reading an
3351 -- out parameter, which is not allowed.
3353 if Ada_Version = Ada_83
3354 and then Is_Entity_Name (A)
3355 and then Ekind (Entity (A)) = E_Out_Parameter
3357 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3361 -- Case of OUT or IN OUT parameter
3363 if Ekind (F) /= E_In_Parameter then
3365 -- For an Out parameter, check for useless assignment. Note
3366 -- that we can't set Last_Assignment this early, because we may
3367 -- kill current values in Resolve_Call, and that call would
3368 -- clobber the Last_Assignment field.
3370 -- Note: call Warn_On_Useless_Assignment before doing the check
3371 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3372 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3373 -- reflects the last assignment, not this one!
3375 if Ekind (F) = E_Out_Parameter then
3376 if Warn_On_Modified_As_Out_Parameter (F)
3377 and then Is_Entity_Name (A)
3378 and then Present (Entity (A))
3379 and then Comes_From_Source (N)
3381 Warn_On_Useless_Assignment (Entity (A), A);
3385 -- Validate the form of the actual. Note that the call to
3386 -- Is_OK_Variable_For_Out_Formal generates the required
3387 -- reference in this case.
3389 if not Is_OK_Variable_For_Out_Formal (A) then
3390 Error_Msg_NE ("actual for& must be a variable", A, F);
3393 -- What's the following about???
3395 if Is_Entity_Name (A) then
3396 Kill_Checks (Entity (A));
3402 if Etype (A) = Any_Type then
3403 Set_Etype (N, Any_Type);
3407 -- Apply appropriate range checks for in, out, and in-out
3408 -- parameters. Out and in-out parameters also need a separate
3409 -- check, if there is a type conversion, to make sure the return
3410 -- value meets the constraints of the variable before the
3413 -- Gigi looks at the check flag and uses the appropriate types.
3414 -- For now since one flag is used there is an optimization which
3415 -- might not be done in the In Out case since Gigi does not do
3416 -- any analysis. More thought required about this ???
3418 if Ekind (F) = E_In_Parameter
3419 or else Ekind (F) = E_In_Out_Parameter
3421 if Is_Scalar_Type (Etype (A)) then
3422 Apply_Scalar_Range_Check (A, F_Typ);
3424 elsif Is_Array_Type (Etype (A)) then
3425 Apply_Length_Check (A, F_Typ);
3427 elsif Is_Record_Type (F_Typ)
3428 and then Has_Discriminants (F_Typ)
3429 and then Is_Constrained (F_Typ)
3430 and then (not Is_Derived_Type (F_Typ)
3431 or else Comes_From_Source (Nam))
3433 Apply_Discriminant_Check (A, F_Typ);
3435 elsif Is_Access_Type (F_Typ)
3436 and then Is_Array_Type (Designated_Type (F_Typ))
3437 and then Is_Constrained (Designated_Type (F_Typ))
3439 Apply_Length_Check (A, F_Typ);
3441 elsif Is_Access_Type (F_Typ)
3442 and then Has_Discriminants (Designated_Type (F_Typ))
3443 and then Is_Constrained (Designated_Type (F_Typ))
3445 Apply_Discriminant_Check (A, F_Typ);
3448 Apply_Range_Check (A, F_Typ);
3451 -- Ada 2005 (AI-231)
3453 if Ada_Version >= Ada_05
3454 and then Is_Access_Type (F_Typ)
3455 and then Can_Never_Be_Null (F_Typ)
3456 and then Known_Null (A)
3458 Apply_Compile_Time_Constraint_Error
3460 Msg => "(Ada 2005) null not allowed in "
3461 & "null-excluding formal?",
3462 Reason => CE_Null_Not_Allowed);
3466 if Ekind (F) = E_Out_Parameter
3467 or else Ekind (F) = E_In_Out_Parameter
3469 if Nkind (A) = N_Type_Conversion then
3470 if Is_Scalar_Type (A_Typ) then
3471 Apply_Scalar_Range_Check
3472 (Expression (A), Etype (Expression (A)), A_Typ);
3475 (Expression (A), Etype (Expression (A)), A_Typ);
3479 if Is_Scalar_Type (F_Typ) then
3480 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3482 elsif Is_Array_Type (F_Typ)
3483 and then Ekind (F) = E_Out_Parameter
3485 Apply_Length_Check (A, F_Typ);
3488 Apply_Range_Check (A, A_Typ, F_Typ);
3493 -- An actual associated with an access parameter is implicitly
3494 -- converted to the anonymous access type of the formal and must
3495 -- satisfy the legality checks for access conversions.
3497 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3498 if not Valid_Conversion (A, F_Typ, A) then
3500 ("invalid implicit conversion for access parameter", A);
3504 -- Check bad case of atomic/volatile argument (RM C.6(12))
3506 if Is_By_Reference_Type (Etype (F))
3507 and then Comes_From_Source (N)
3509 if Is_Atomic_Object (A)
3510 and then not Is_Atomic (Etype (F))
3513 ("cannot pass atomic argument to non-atomic formal",
3516 elsif Is_Volatile_Object (A)
3517 and then not Is_Volatile (Etype (F))
3520 ("cannot pass volatile argument to non-volatile formal",
3525 -- Check that subprograms don't have improper controlling
3526 -- arguments (RM 3.9.2 (9))
3528 -- A primitive operation may have an access parameter of an
3529 -- incomplete tagged type, but a dispatching call is illegal
3530 -- if the type is still incomplete.
3532 if Is_Controlling_Formal (F) then
3533 Set_Is_Controlling_Actual (A);
3535 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3537 Desig : constant Entity_Id := Designated_Type (Etype (F));
3539 if Ekind (Desig) = E_Incomplete_Type
3540 and then No (Full_View (Desig))
3541 and then No (Non_Limited_View (Desig))
3544 ("premature use of incomplete type& " &
3545 "in dispatching call", A, Desig);
3550 elsif Nkind (A) = N_Explicit_Dereference then
3551 Validate_Remote_Access_To_Class_Wide_Type (A);
3554 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3555 and then not Is_Class_Wide_Type (F_Typ)
3556 and then not Is_Controlling_Formal (F)
3558 Error_Msg_N ("class-wide argument not allowed here!", A);
3560 if Is_Subprogram (Nam)
3561 and then Comes_From_Source (Nam)
3563 Error_Msg_Node_2 := F_Typ;
3565 ("& is not a dispatching operation of &!", A, Nam);
3568 elsif Is_Access_Type (A_Typ)
3569 and then Is_Access_Type (F_Typ)
3570 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3571 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3572 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3573 or else (Nkind (A) = N_Attribute_Reference
3575 Is_Class_Wide_Type (Etype (Prefix (A)))))
3576 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3577 and then not Is_Controlling_Formal (F)
3580 ("access to class-wide argument not allowed here!", A);
3582 if Is_Subprogram (Nam)
3583 and then Comes_From_Source (Nam)
3585 Error_Msg_Node_2 := Designated_Type (F_Typ);
3587 ("& is not a dispatching operation of &!", A, Nam);
3593 -- If it is a named association, treat the selector_name as
3594 -- a proper identifier, and mark the corresponding entity.
3596 if Nkind (Parent (A)) = N_Parameter_Association then
3597 Set_Entity (Selector_Name (Parent (A)), F);
3598 Generate_Reference (F, Selector_Name (Parent (A)));
3599 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3600 Generate_Reference (F_Typ, N, ' ');
3605 if Ekind (F) /= E_Out_Parameter then
3606 Check_Unset_Reference (A);
3611 -- Case where actual is not present
3619 end Resolve_Actuals;
3621 -----------------------
3622 -- Resolve_Allocator --
3623 -----------------------
3625 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3626 E : constant Node_Id := Expression (N);
3628 Discrim : Entity_Id;
3631 Assoc : Node_Id := Empty;
3634 procedure Check_Allocator_Discrim_Accessibility
3635 (Disc_Exp : Node_Id;
3636 Alloc_Typ : Entity_Id);
3637 -- Check that accessibility level associated with an access discriminant
3638 -- initialized in an allocator by the expression Disc_Exp is not deeper
3639 -- than the level of the allocator type Alloc_Typ. An error message is
3640 -- issued if this condition is violated. Specialized checks are done for
3641 -- the cases of a constraint expression which is an access attribute or
3642 -- an access discriminant.
3644 function In_Dispatching_Context return Boolean;
3645 -- If the allocator is an actual in a call, it is allowed to be class-
3646 -- wide when the context is not because it is a controlling actual.
3648 procedure Propagate_Coextensions (Root : Node_Id);
3649 -- Propagate all nested coextensions which are located one nesting
3650 -- level down the tree to the node Root. Example:
3653 -- Level_1_Coextension
3654 -- Level_2_Coextension
3656 -- The algorithm is paired with delay actions done by the Expander. In
3657 -- the above example, assume all coextensions are controlled types.
3658 -- The cycle of analysis, resolution and expansion will yield:
3660 -- 1) Analyze Top_Record
3661 -- 2) Analyze Level_1_Coextension
3662 -- 3) Analyze Level_2_Coextension
3663 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3665 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3666 -- generated to capture the allocated object. Temp_1 is attached
3667 -- to the coextension chain of Level_2_Coextension.
3668 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3669 -- coextension. A forward tree traversal is performed which finds
3670 -- Level_2_Coextension's list and copies its contents into its
3672 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3673 -- generated to capture the allocated object. Temp_2 is attached
3674 -- to the coextension chain of Level_1_Coextension. Currently, the
3675 -- contents of the list are [Temp_2, Temp_1].
3676 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3677 -- finds Level_1_Coextension's list and copies its contents into
3679 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3680 -- Temp_2 and attach them to Top_Record's finalization list.
3682 -------------------------------------------
3683 -- Check_Allocator_Discrim_Accessibility --
3684 -------------------------------------------
3686 procedure Check_Allocator_Discrim_Accessibility
3687 (Disc_Exp : Node_Id;
3688 Alloc_Typ : Entity_Id)
3691 if Type_Access_Level (Etype (Disc_Exp)) >
3692 Type_Access_Level (Alloc_Typ)
3695 ("operand type has deeper level than allocator type", Disc_Exp);
3697 -- When the expression is an Access attribute the level of the prefix
3698 -- object must not be deeper than that of the allocator's type.
3700 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3701 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3703 and then Object_Access_Level (Prefix (Disc_Exp))
3704 > Type_Access_Level (Alloc_Typ)
3707 ("prefix of attribute has deeper level than allocator type",
3710 -- When the expression is an access discriminant the check is against
3711 -- the level of the prefix object.
3713 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3714 and then Nkind (Disc_Exp) = N_Selected_Component
3715 and then Object_Access_Level (Prefix (Disc_Exp))
3716 > Type_Access_Level (Alloc_Typ)
3719 ("access discriminant has deeper level than allocator type",
3722 -- All other cases are legal
3727 end Check_Allocator_Discrim_Accessibility;
3729 ----------------------------
3730 -- In_Dispatching_Context --
3731 ----------------------------
3733 function In_Dispatching_Context return Boolean is
3734 Par : constant Node_Id := Parent (N);
3736 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3737 and then Is_Entity_Name (Name (Par))
3738 and then Is_Dispatching_Operation (Entity (Name (Par)));
3739 end In_Dispatching_Context;
3741 ----------------------------
3742 -- Propagate_Coextensions --
3743 ----------------------------
3745 procedure Propagate_Coextensions (Root : Node_Id) is
3747 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3748 -- Copy the contents of list From into list To, preserving the
3749 -- order of elements.
3751 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3752 -- Recognize an allocator or a rewritten allocator node and add it
3753 -- along with its nested coextensions to the list of Root.
3759 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3760 From_Elmt : Elmt_Id;
3762 From_Elmt := First_Elmt (From);
3763 while Present (From_Elmt) loop
3764 Append_Elmt (Node (From_Elmt), To);
3765 Next_Elmt (From_Elmt);
3769 -----------------------
3770 -- Process_Allocator --
3771 -----------------------
3773 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3774 Orig_Nod : Node_Id := Nod;
3777 -- This is a possible rewritten subtype indication allocator. Any
3778 -- nested coextensions will appear as discriminant constraints.
3780 if Nkind (Nod) = N_Identifier
3781 and then Present (Original_Node (Nod))
3782 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3786 Discr_Elmt : Elmt_Id;
3789 if Is_Record_Type (Entity (Nod)) then
3791 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3792 while Present (Discr_Elmt) loop
3793 Discr := Node (Discr_Elmt);
3795 if Nkind (Discr) = N_Identifier
3796 and then Present (Original_Node (Discr))
3797 and then Nkind (Original_Node (Discr)) = N_Allocator
3798 and then Present (Coextensions (
3799 Original_Node (Discr)))
3801 if No (Coextensions (Root)) then
3802 Set_Coextensions (Root, New_Elmt_List);
3806 (From => Coextensions (Original_Node (Discr)),
3807 To => Coextensions (Root));
3810 Next_Elmt (Discr_Elmt);
3813 -- There is no need to continue the traversal of this
3814 -- subtree since all the information has already been
3821 -- Case of either a stand alone allocator or a rewritten allocator
3822 -- with an aggregate.
3825 if Present (Original_Node (Nod)) then
3826 Orig_Nod := Original_Node (Nod);
3829 if Nkind (Orig_Nod) = N_Allocator then
3831 -- Propagate the list of nested coextensions to the Root
3832 -- allocator. This is done through list copy since a single
3833 -- allocator may have multiple coextensions. Do not touch
3834 -- coextensions roots.
3836 if not Is_Coextension_Root (Orig_Nod)
3837 and then Present (Coextensions (Orig_Nod))
3839 if No (Coextensions (Root)) then
3840 Set_Coextensions (Root, New_Elmt_List);
3844 (From => Coextensions (Orig_Nod),
3845 To => Coextensions (Root));
3848 -- There is no need to continue the traversal of this
3849 -- subtree since all the information has already been
3856 -- Keep on traversing, looking for the next allocator
3859 end Process_Allocator;
3861 procedure Process_Allocators is
3862 new Traverse_Proc (Process_Allocator);
3864 -- Start of processing for Propagate_Coextensions
3867 Process_Allocators (Expression (Root));
3868 end Propagate_Coextensions;
3870 -- Start of processing for Resolve_Allocator
3873 -- Replace general access with specific type
3875 if Ekind (Etype (N)) = E_Allocator_Type then
3876 Set_Etype (N, Base_Type (Typ));
3879 if Is_Abstract_Type (Typ) then
3880 Error_Msg_N ("type of allocator cannot be abstract", N);
3883 -- For qualified expression, resolve the expression using the
3884 -- given subtype (nothing to do for type mark, subtype indication)
3886 if Nkind (E) = N_Qualified_Expression then
3887 if Is_Class_Wide_Type (Etype (E))
3888 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3889 and then not In_Dispatching_Context
3892 ("class-wide allocator not allowed for this access type", N);
3895 Resolve (Expression (E), Etype (E));
3896 Check_Unset_Reference (Expression (E));
3898 -- A qualified expression requires an exact match of the type,
3899 -- class-wide matching is not allowed.
3901 if (Is_Class_Wide_Type (Etype (Expression (E)))
3902 or else Is_Class_Wide_Type (Etype (E)))
3903 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3905 Wrong_Type (Expression (E), Etype (E));
3908 -- A special accessibility check is needed for allocators that
3909 -- constrain access discriminants. The level of the type of the
3910 -- expression used to constrain an access discriminant cannot be
3911 -- deeper than the type of the allocator (in contrast to access
3912 -- parameters, where the level of the actual can be arbitrary).
3914 -- We can't use Valid_Conversion to perform this check because
3915 -- in general the type of the allocator is unrelated to the type
3916 -- of the access discriminant.
3918 if Ekind (Typ) /= E_Anonymous_Access_Type
3919 or else Is_Local_Anonymous_Access (Typ)
3921 Subtyp := Entity (Subtype_Mark (E));
3923 Aggr := Original_Node (Expression (E));
3925 if Has_Discriminants (Subtyp)
3926 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
3928 Discrim := First_Discriminant (Base_Type (Subtyp));
3930 -- Get the first component expression of the aggregate
3932 if Present (Expressions (Aggr)) then
3933 Disc_Exp := First (Expressions (Aggr));
3935 elsif Present (Component_Associations (Aggr)) then
3936 Assoc := First (Component_Associations (Aggr));
3938 if Present (Assoc) then
3939 Disc_Exp := Expression (Assoc);
3948 while Present (Discrim) and then Present (Disc_Exp) loop
3949 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3950 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
3953 Next_Discriminant (Discrim);
3955 if Present (Discrim) then
3956 if Present (Assoc) then
3958 Disc_Exp := Expression (Assoc);
3960 elsif Present (Next (Disc_Exp)) then
3964 Assoc := First (Component_Associations (Aggr));
3966 if Present (Assoc) then
3967 Disc_Exp := Expression (Assoc);
3977 -- For a subtype mark or subtype indication, freeze the subtype
3980 Freeze_Expression (E);
3982 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
3984 ("initialization required for access-to-constant allocator", N);
3987 -- A special accessibility check is needed for allocators that
3988 -- constrain access discriminants. The level of the type of the
3989 -- expression used to constrain an access discriminant cannot be
3990 -- deeper than the type of the allocator (in contrast to access
3991 -- parameters, where the level of the actual can be arbitrary).
3992 -- We can't use Valid_Conversion to perform this check because
3993 -- in general the type of the allocator is unrelated to the type
3994 -- of the access discriminant.
3996 if Nkind (Original_Node (E)) = N_Subtype_Indication
3997 and then (Ekind (Typ) /= E_Anonymous_Access_Type
3998 or else Is_Local_Anonymous_Access (Typ))
4000 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4002 if Has_Discriminants (Subtyp) then
4003 Discrim := First_Discriminant (Base_Type (Subtyp));
4004 Constr := First (Constraints (Constraint (Original_Node (E))));
4005 while Present (Discrim) and then Present (Constr) loop
4006 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4007 if Nkind (Constr) = N_Discriminant_Association then
4008 Disc_Exp := Original_Node (Expression (Constr));
4010 Disc_Exp := Original_Node (Constr);
4013 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4016 Next_Discriminant (Discrim);
4023 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4024 -- check that the level of the type of the created object is not deeper
4025 -- than the level of the allocator's access type, since extensions can
4026 -- now occur at deeper levels than their ancestor types. This is a
4027 -- static accessibility level check; a run-time check is also needed in
4028 -- the case of an initialized allocator with a class-wide argument (see
4029 -- Expand_Allocator_Expression).
4031 if Ada_Version >= Ada_05
4032 and then Is_Class_Wide_Type (Designated_Type (Typ))
4035 Exp_Typ : Entity_Id;
4038 if Nkind (E) = N_Qualified_Expression then
4039 Exp_Typ := Etype (E);
4040 elsif Nkind (E) = N_Subtype_Indication then
4041 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4043 Exp_Typ := Entity (E);
4046 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4047 if In_Instance_Body then
4048 Error_Msg_N ("?type in allocator has deeper level than" &
4049 " designated class-wide type", E);
4050 Error_Msg_N ("\?Program_Error will be raised at run time",
4053 Make_Raise_Program_Error (Sloc (N),
4054 Reason => PE_Accessibility_Check_Failed));
4057 -- Do not apply Ada 2005 accessibility checks on a class-wide
4058 -- allocator if the type given in the allocator is a formal
4059 -- type. A run-time check will be performed in the instance.
4061 elsif not Is_Generic_Type (Exp_Typ) then
4062 Error_Msg_N ("type in allocator has deeper level than" &
4063 " designated class-wide type", E);
4069 -- Check for allocation from an empty storage pool
4071 if No_Pool_Assigned (Typ) then
4073 Loc : constant Source_Ptr := Sloc (N);
4075 Error_Msg_N ("?allocation from empty storage pool!", N);
4076 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4078 Make_Raise_Storage_Error (Loc,
4079 Reason => SE_Empty_Storage_Pool));
4082 -- If the context is an unchecked conversion, as may happen within
4083 -- an inlined subprogram, the allocator is being resolved with its
4084 -- own anonymous type. In that case, if the target type has a specific
4085 -- storage pool, it must be inherited explicitly by the allocator type.
4087 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4088 and then No (Associated_Storage_Pool (Typ))
4090 Set_Associated_Storage_Pool
4091 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4094 -- An erroneous allocator may be rewritten as a raise Program_Error
4097 if Nkind (N) = N_Allocator then
4099 -- An anonymous access discriminant is the definition of a
4102 if Ekind (Typ) = E_Anonymous_Access_Type
4103 and then Nkind (Associated_Node_For_Itype (Typ)) =
4104 N_Discriminant_Specification
4106 -- Avoid marking an allocator as a dynamic coextension if it is
4107 -- within a static construct.
4109 if not Is_Static_Coextension (N) then
4110 Set_Is_Dynamic_Coextension (N);
4113 -- Cleanup for potential static coextensions
4116 Set_Is_Dynamic_Coextension (N, False);
4117 Set_Is_Static_Coextension (N, False);
4120 -- There is no need to propagate any nested coextensions if they
4121 -- are marked as static since they will be rewritten on the spot.
4123 if not Is_Static_Coextension (N) then
4124 Propagate_Coextensions (N);
4127 end Resolve_Allocator;
4129 ---------------------------
4130 -- Resolve_Arithmetic_Op --
4131 ---------------------------
4133 -- Used for resolving all arithmetic operators except exponentiation
4135 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4136 L : constant Node_Id := Left_Opnd (N);
4137 R : constant Node_Id := Right_Opnd (N);
4138 TL : constant Entity_Id := Base_Type (Etype (L));
4139 TR : constant Entity_Id := Base_Type (Etype (R));
4143 B_Typ : constant Entity_Id := Base_Type (Typ);
4144 -- We do the resolution using the base type, because intermediate values
4145 -- in expressions always are of the base type, not a subtype of it.
4147 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4148 -- Returns True if N is in a context that expects "any real type"
4150 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4151 -- Return True iff given type is Integer or universal real/integer
4153 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4154 -- Choose type of integer literal in fixed-point operation to conform
4155 -- to available fixed-point type. T is the type of the other operand,
4156 -- which is needed to determine the expected type of N.
4158 procedure Set_Operand_Type (N : Node_Id);
4159 -- Set operand type to T if universal
4161 -------------------------------
4162 -- Expected_Type_Is_Any_Real --
4163 -------------------------------
4165 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4167 -- N is the expression after "delta" in a fixed_point_definition;
4170 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4171 N_Decimal_Fixed_Point_Definition,
4173 -- N is one of the bounds in a real_range_specification;
4176 N_Real_Range_Specification,
4178 -- N is the expression of a delta_constraint;
4181 N_Delta_Constraint);
4182 end Expected_Type_Is_Any_Real;
4184 -----------------------------
4185 -- Is_Integer_Or_Universal --
4186 -----------------------------
4188 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4190 Index : Interp_Index;
4194 if not Is_Overloaded (N) then
4196 return Base_Type (T) = Base_Type (Standard_Integer)
4197 or else T = Universal_Integer
4198 or else T = Universal_Real;
4200 Get_First_Interp (N, Index, It);
4201 while Present (It.Typ) loop
4202 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4203 or else It.Typ = Universal_Integer
4204 or else It.Typ = Universal_Real
4209 Get_Next_Interp (Index, It);
4214 end Is_Integer_Or_Universal;
4216 ----------------------------
4217 -- Set_Mixed_Mode_Operand --
4218 ----------------------------
4220 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4221 Index : Interp_Index;
4225 if Universal_Interpretation (N) = Universal_Integer then
4227 -- A universal integer literal is resolved as standard integer
4228 -- except in the case of a fixed-point result, where we leave it
4229 -- as universal (to be handled by Exp_Fixd later on)
4231 if Is_Fixed_Point_Type (T) then
4232 Resolve (N, Universal_Integer);
4234 Resolve (N, Standard_Integer);
4237 elsif Universal_Interpretation (N) = Universal_Real
4238 and then (T = Base_Type (Standard_Integer)
4239 or else T = Universal_Integer
4240 or else T = Universal_Real)
4242 -- A universal real can appear in a fixed-type context. We resolve
4243 -- the literal with that context, even though this might raise an
4244 -- exception prematurely (the other operand may be zero).
4248 elsif Etype (N) = Base_Type (Standard_Integer)
4249 and then T = Universal_Real
4250 and then Is_Overloaded (N)
4252 -- Integer arg in mixed-mode operation. Resolve with universal
4253 -- type, in case preference rule must be applied.
4255 Resolve (N, Universal_Integer);
4258 and then B_Typ /= Universal_Fixed
4260 -- Not a mixed-mode operation, resolve with context
4264 elsif Etype (N) = Any_Fixed then
4266 -- N may itself be a mixed-mode operation, so use context type
4270 elsif Is_Fixed_Point_Type (T)
4271 and then B_Typ = Universal_Fixed
4272 and then Is_Overloaded (N)
4274 -- Must be (fixed * fixed) operation, operand must have one
4275 -- compatible interpretation.
4277 Resolve (N, Any_Fixed);
4279 elsif Is_Fixed_Point_Type (B_Typ)
4280 and then (T = Universal_Real
4281 or else Is_Fixed_Point_Type (T))
4282 and then Is_Overloaded (N)
4284 -- C * F(X) in a fixed context, where C is a real literal or a
4285 -- fixed-point expression. F must have either a fixed type
4286 -- interpretation or an integer interpretation, but not both.
4288 Get_First_Interp (N, Index, It);
4289 while Present (It.Typ) loop
4290 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4292 if Analyzed (N) then
4293 Error_Msg_N ("ambiguous operand in fixed operation", N);
4295 Resolve (N, Standard_Integer);
4298 elsif Is_Fixed_Point_Type (It.Typ) then
4300 if Analyzed (N) then
4301 Error_Msg_N ("ambiguous operand in fixed operation", N);
4303 Resolve (N, It.Typ);
4307 Get_Next_Interp (Index, It);
4310 -- Reanalyze the literal with the fixed type of the context. If
4311 -- context is Universal_Fixed, we are within a conversion, leave
4312 -- the literal as a universal real because there is no usable
4313 -- fixed type, and the target of the conversion plays no role in
4327 if B_Typ = Universal_Fixed
4328 and then Nkind (Op2) = N_Real_Literal
4330 T2 := Universal_Real;
4335 Set_Analyzed (Op2, False);
4342 end Set_Mixed_Mode_Operand;
4344 ----------------------
4345 -- Set_Operand_Type --
4346 ----------------------
4348 procedure Set_Operand_Type (N : Node_Id) is
4350 if Etype (N) = Universal_Integer
4351 or else Etype (N) = Universal_Real
4355 end Set_Operand_Type;
4357 -- Start of processing for Resolve_Arithmetic_Op
4360 if Comes_From_Source (N)
4361 and then Ekind (Entity (N)) = E_Function
4362 and then Is_Imported (Entity (N))
4363 and then Is_Intrinsic_Subprogram (Entity (N))
4365 Resolve_Intrinsic_Operator (N, Typ);
4368 -- Special-case for mixed-mode universal expressions or fixed point
4369 -- type operation: each argument is resolved separately. The same
4370 -- treatment is required if one of the operands of a fixed point
4371 -- operation is universal real, since in this case we don't do a
4372 -- conversion to a specific fixed-point type (instead the expander
4373 -- takes care of the case).
4375 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4376 and then Present (Universal_Interpretation (L))
4377 and then Present (Universal_Interpretation (R))
4379 Resolve (L, Universal_Interpretation (L));
4380 Resolve (R, Universal_Interpretation (R));
4381 Set_Etype (N, B_Typ);
4383 elsif (B_Typ = Universal_Real
4384 or else Etype (N) = Universal_Fixed
4385 or else (Etype (N) = Any_Fixed
4386 and then Is_Fixed_Point_Type (B_Typ))
4387 or else (Is_Fixed_Point_Type (B_Typ)
4388 and then (Is_Integer_Or_Universal (L)
4390 Is_Integer_Or_Universal (R))))
4391 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4393 if TL = Universal_Integer or else TR = Universal_Integer then
4394 Check_For_Visible_Operator (N, B_Typ);
4397 -- If context is a fixed type and one operand is integer, the
4398 -- other is resolved with the type of the context.
4400 if Is_Fixed_Point_Type (B_Typ)
4401 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4402 or else TL = Universal_Integer)
4407 elsif Is_Fixed_Point_Type (B_Typ)
4408 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4409 or else TR = Universal_Integer)
4415 Set_Mixed_Mode_Operand (L, TR);
4416 Set_Mixed_Mode_Operand (R, TL);
4419 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4420 -- multiplying operators from being used when the expected type is
4421 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4422 -- some cases where the expected type is actually Any_Real;
4423 -- Expected_Type_Is_Any_Real takes care of that case.
4425 if Etype (N) = Universal_Fixed
4426 or else Etype (N) = Any_Fixed
4428 if B_Typ = Universal_Fixed
4429 and then not Expected_Type_Is_Any_Real (N)
4430 and then not Nkind_In (Parent (N), N_Type_Conversion,
4431 N_Unchecked_Type_Conversion)
4433 Error_Msg_N ("type cannot be determined from context!", N);
4434 Error_Msg_N ("\explicit conversion to result type required", N);
4436 Set_Etype (L, Any_Type);
4437 Set_Etype (R, Any_Type);
4440 if Ada_Version = Ada_83
4441 and then Etype (N) = Universal_Fixed
4443 Nkind_In (Parent (N), N_Type_Conversion,
4444 N_Unchecked_Type_Conversion)
4447 ("(Ada 83) fixed-point operation "
4448 & "needs explicit conversion", N);
4451 -- The expected type is "any real type" in contexts like
4452 -- type T is delta <universal_fixed-expression> ...
4453 -- in which case we need to set the type to Universal_Real
4454 -- so that static expression evaluation will work properly.
4456 if Expected_Type_Is_Any_Real (N) then
4457 Set_Etype (N, Universal_Real);
4459 Set_Etype (N, B_Typ);
4463 elsif Is_Fixed_Point_Type (B_Typ)
4464 and then (Is_Integer_Or_Universal (L)
4465 or else Nkind (L) = N_Real_Literal
4466 or else Nkind (R) = N_Real_Literal
4467 or else Is_Integer_Or_Universal (R))
4469 Set_Etype (N, B_Typ);
4471 elsif Etype (N) = Any_Fixed then
4473 -- If no previous errors, this is only possible if one operand
4474 -- is overloaded and the context is universal. Resolve as such.
4476 Set_Etype (N, B_Typ);
4480 if (TL = Universal_Integer or else TL = Universal_Real)
4482 (TR = Universal_Integer or else TR = Universal_Real)
4484 Check_For_Visible_Operator (N, B_Typ);
4487 -- If the context is Universal_Fixed and the operands are also
4488 -- universal fixed, this is an error, unless there is only one
4489 -- applicable fixed_point type (usually duration).
4491 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4492 T := Unique_Fixed_Point_Type (N);
4494 if T = Any_Type then
4507 -- If one of the arguments was resolved to a non-universal type.
4508 -- label the result of the operation itself with the same type.
4509 -- Do the same for the universal argument, if any.
4511 T := Intersect_Types (L, R);
4512 Set_Etype (N, Base_Type (T));
4513 Set_Operand_Type (L);
4514 Set_Operand_Type (R);
4517 Generate_Operator_Reference (N, Typ);
4518 Eval_Arithmetic_Op (N);
4520 -- Set overflow and division checking bit. Much cleverer code needed
4521 -- here eventually and perhaps the Resolve routines should be separated
4522 -- for the various arithmetic operations, since they will need
4523 -- different processing. ???
4525 if Nkind (N) in N_Op then
4526 if not Overflow_Checks_Suppressed (Etype (N)) then
4527 Enable_Overflow_Check (N);
4530 -- Give warning if explicit division by zero
4532 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4533 and then not Division_Checks_Suppressed (Etype (N))
4535 Rop := Right_Opnd (N);
4537 if Compile_Time_Known_Value (Rop)
4538 and then ((Is_Integer_Type (Etype (Rop))
4539 and then Expr_Value (Rop) = Uint_0)
4541 (Is_Real_Type (Etype (Rop))
4542 and then Expr_Value_R (Rop) = Ureal_0))
4544 -- Specialize the warning message according to the operation
4548 Apply_Compile_Time_Constraint_Error
4549 (N, "division by zero?", CE_Divide_By_Zero,
4550 Loc => Sloc (Right_Opnd (N)));
4553 Apply_Compile_Time_Constraint_Error
4554 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4555 Loc => Sloc (Right_Opnd (N)));
4558 Apply_Compile_Time_Constraint_Error
4559 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4560 Loc => Sloc (Right_Opnd (N)));
4562 -- Division by zero can only happen with division, rem,
4563 -- and mod operations.
4566 raise Program_Error;
4569 -- Otherwise just set the flag to check at run time
4572 Activate_Division_Check (N);
4576 -- If Restriction No_Implicit_Conditionals is active, then it is
4577 -- violated if either operand can be negative for mod, or for rem
4578 -- if both operands can be negative.
4580 if Restrictions.Set (No_Implicit_Conditionals)
4581 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4590 -- Set if corresponding operand might be negative
4593 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4594 LNeg := (not OK) or else Lo < 0;
4596 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4597 RNeg := (not OK) or else Lo < 0;
4599 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4601 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4603 Check_Restriction (No_Implicit_Conditionals, N);
4609 Check_Unset_Reference (L);
4610 Check_Unset_Reference (R);
4611 end Resolve_Arithmetic_Op;
4617 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4618 Loc : constant Source_Ptr := Sloc (N);
4619 Subp : constant Node_Id := Name (N);
4628 -- The context imposes a unique interpretation with type Typ on a
4629 -- procedure or function call. Find the entity of the subprogram that
4630 -- yields the expected type, and propagate the corresponding formal
4631 -- constraints on the actuals. The caller has established that an
4632 -- interpretation exists, and emitted an error if not unique.
4634 -- First deal with the case of a call to an access-to-subprogram,
4635 -- dereference made explicit in Analyze_Call.
4637 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4638 if not Is_Overloaded (Subp) then
4639 Nam := Etype (Subp);
4642 -- Find the interpretation whose type (a subprogram type) has a
4643 -- return type that is compatible with the context. Analysis of
4644 -- the node has established that one exists.
4648 Get_First_Interp (Subp, I, It);
4649 while Present (It.Typ) loop
4650 if Covers (Typ, Etype (It.Typ)) then
4655 Get_Next_Interp (I, It);
4659 raise Program_Error;
4663 -- If the prefix is not an entity, then resolve it
4665 if not Is_Entity_Name (Subp) then
4666 Resolve (Subp, Nam);
4669 -- For an indirect call, we always invalidate checks, since we do not
4670 -- know whether the subprogram is local or global. Yes we could do
4671 -- better here, e.g. by knowing that there are no local subprograms,
4672 -- but it does not seem worth the effort. Similarly, we kill all
4673 -- knowledge of current constant values.
4675 Kill_Current_Values;
4677 -- If this is a procedure call which is really an entry call, do
4678 -- the conversion of the procedure call to an entry call. Protected
4679 -- operations use the same circuitry because the name in the call
4680 -- can be an arbitrary expression with special resolution rules.
4682 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4683 or else (Is_Entity_Name (Subp)
4684 and then Ekind (Entity (Subp)) = E_Entry)
4686 Resolve_Entry_Call (N, Typ);
4687 Check_Elab_Call (N);
4689 -- Kill checks and constant values, as above for indirect case
4690 -- Who knows what happens when another task is activated?
4692 Kill_Current_Values;
4695 -- Normal subprogram call with name established in Resolve
4697 elsif not (Is_Type (Entity (Subp))) then
4698 Nam := Entity (Subp);
4699 Set_Entity_With_Style_Check (Subp, Nam);
4701 -- Otherwise we must have the case of an overloaded call
4704 pragma Assert (Is_Overloaded (Subp));
4705 Nam := Empty; -- We know that it will be assigned in loop below
4707 Get_First_Interp (Subp, I, It);
4708 while Present (It.Typ) loop
4709 if Covers (Typ, It.Typ) then
4711 Set_Entity_With_Style_Check (Subp, Nam);
4715 Get_Next_Interp (I, It);
4719 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4720 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4721 and then Nkind (Subp) /= N_Explicit_Dereference
4722 and then Present (Parameter_Associations (N))
4724 -- The prefix is a parameterless function call that returns an access
4725 -- to subprogram. If parameters are present in the current call, add
4726 -- add an explicit dereference. We use the base type here because
4727 -- within an instance these may be subtypes.
4729 -- The dereference is added either in Analyze_Call or here. Should
4730 -- be consolidated ???
4732 Set_Is_Overloaded (Subp, False);
4733 Set_Etype (Subp, Etype (Nam));
4734 Insert_Explicit_Dereference (Subp);
4735 Nam := Designated_Type (Etype (Nam));
4736 Resolve (Subp, Nam);
4739 -- Check that a call to Current_Task does not occur in an entry body
4741 if Is_RTE (Nam, RE_Current_Task) then
4750 -- Exclude calls that occur within the default of a formal
4751 -- parameter of the entry, since those are evaluated outside
4754 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4756 if Nkind (P) = N_Entry_Body
4757 or else (Nkind (P) = N_Subprogram_Body
4758 and then Is_Entry_Barrier_Function (P))
4762 ("?& should not be used in entry body (RM C.7(17))",
4765 ("\Program_Error will be raised at run time?", N, Nam);
4767 Make_Raise_Program_Error (Loc,
4768 Reason => PE_Current_Task_In_Entry_Body));
4769 Set_Etype (N, Rtype);
4776 -- Check that a procedure call does not occur in the context of the
4777 -- entry call statement of a conditional or timed entry call. Note that
4778 -- the case of a call to a subprogram renaming of an entry will also be
4779 -- rejected. The test for N not being an N_Entry_Call_Statement is
4780 -- defensive, covering the possibility that the processing of entry
4781 -- calls might reach this point due to later modifications of the code
4784 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4785 and then Nkind (N) /= N_Entry_Call_Statement
4786 and then Entry_Call_Statement (Parent (N)) = N
4788 if Ada_Version < Ada_05 then
4789 Error_Msg_N ("entry call required in select statement", N);
4791 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4792 -- for a procedure_or_entry_call, the procedure_name or
4793 -- procedure_prefix of the procedure_call_statement shall denote
4794 -- an entry renamed by a procedure, or (a view of) a primitive
4795 -- subprogram of a limited interface whose first parameter is
4796 -- a controlling parameter.
4798 elsif Nkind (N) = N_Procedure_Call_Statement
4799 and then not Is_Renamed_Entry (Nam)
4800 and then not Is_Controlling_Limited_Procedure (Nam)
4803 ("entry call or dispatching primitive of interface required", N);
4807 -- Check that this is not a call to a protected procedure or entry from
4808 -- within a protected function.
4810 if Ekind (Current_Scope) = E_Function
4811 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4812 and then Ekind (Nam) /= E_Function
4813 and then Scope (Nam) = Scope (Current_Scope)
4815 Error_Msg_N ("within protected function, protected " &
4816 "object is constant", N);
4817 Error_Msg_N ("\cannot call operation that may modify it", N);
4820 -- Freeze the subprogram name if not in a spec-expression. Note that we
4821 -- freeze procedure calls as well as function calls. Procedure calls are
4822 -- not frozen according to the rules (RM 13.14(14)) because it is
4823 -- impossible to have a procedure call to a non-frozen procedure in pure
4824 -- Ada, but in the code that we generate in the expander, this rule
4825 -- needs extending because we can generate procedure calls that need
4828 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4829 Freeze_Expression (Subp);
4832 -- For a predefined operator, the type of the result is the type imposed
4833 -- by context, except for a predefined operation on universal fixed.
4834 -- Otherwise The type of the call is the type returned by the subprogram
4837 if Is_Predefined_Op (Nam) then
4838 if Etype (N) /= Universal_Fixed then
4842 -- If the subprogram returns an array type, and the context requires the
4843 -- component type of that array type, the node is really an indexing of
4844 -- the parameterless call. Resolve as such. A pathological case occurs
4845 -- when the type of the component is an access to the array type. In
4846 -- this case the call is truly ambiguous.
4848 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4850 ((Is_Array_Type (Etype (Nam))
4851 and then Covers (Typ, Component_Type (Etype (Nam))))
4852 or else (Is_Access_Type (Etype (Nam))
4853 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4856 Component_Type (Designated_Type (Etype (Nam))))))
4859 Index_Node : Node_Id;
4861 Ret_Type : constant Entity_Id := Etype (Nam);
4864 if Is_Access_Type (Ret_Type)
4865 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4868 ("cannot disambiguate function call and indexing", N);
4870 New_Subp := Relocate_Node (Subp);
4871 Set_Entity (Subp, Nam);
4873 if Component_Type (Ret_Type) /= Any_Type then
4874 if Needs_No_Actuals (Nam) then
4876 -- Indexed call to a parameterless function
4879 Make_Indexed_Component (Loc,
4881 Make_Function_Call (Loc,
4883 Expressions => Parameter_Associations (N));
4885 -- An Ada 2005 prefixed call to a primitive operation
4886 -- whose first parameter is the prefix. This prefix was
4887 -- prepended to the parameter list, which is actually a
4888 -- list of indices. Remove the prefix in order to build
4889 -- the proper indexed component.
4892 Make_Indexed_Component (Loc,
4894 Make_Function_Call (Loc,
4896 Parameter_Associations =>
4898 (Remove_Head (Parameter_Associations (N)))),
4899 Expressions => Parameter_Associations (N));
4902 -- Since we are correcting a node classification error made
4903 -- by the parser, we call Replace rather than Rewrite.
4905 Replace (N, Index_Node);
4906 Set_Etype (Prefix (N), Ret_Type);
4908 Resolve_Indexed_Component (N, Typ);
4909 Check_Elab_Call (Prefix (N));
4917 Set_Etype (N, Etype (Nam));
4920 -- In the case where the call is to an overloaded subprogram, Analyze
4921 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
4922 -- such a case Normalize_Actuals needs to be called once more to order
4923 -- the actuals correctly. Otherwise the call will have the ordering
4924 -- given by the last overloaded subprogram whether this is the correct
4925 -- one being called or not.
4927 if Is_Overloaded (Subp) then
4928 Normalize_Actuals (N, Nam, False, Norm_OK);
4929 pragma Assert (Norm_OK);
4932 -- In any case, call is fully resolved now. Reset Overload flag, to
4933 -- prevent subsequent overload resolution if node is analyzed again
4935 Set_Is_Overloaded (Subp, False);
4936 Set_Is_Overloaded (N, False);
4938 -- If we are calling the current subprogram from immediately within its
4939 -- body, then that is the case where we can sometimes detect cases of
4940 -- infinite recursion statically. Do not try this in case restriction
4941 -- No_Recursion is in effect anyway, and do it only for source calls.
4943 if Comes_From_Source (N) then
4944 Scop := Current_Scope;
4946 -- Issue warning for possible infinite recursion in the absence
4947 -- of the No_Recursion restriction.
4950 and then not Restriction_Active (No_Recursion)
4951 and then Check_Infinite_Recursion (N)
4953 -- Here we detected and flagged an infinite recursion, so we do
4954 -- not need to test the case below for further warnings. Also if
4955 -- we now have a raise SE node, we are all done.
4957 if Nkind (N) = N_Raise_Storage_Error then
4961 -- If call is to immediately containing subprogram, then check for
4962 -- the case of a possible run-time detectable infinite recursion.
4965 Scope_Loop : while Scop /= Standard_Standard loop
4968 -- Although in general case, recursion is not statically
4969 -- checkable, the case of calling an immediately containing
4970 -- subprogram is easy to catch.
4972 Check_Restriction (No_Recursion, N);
4974 -- If the recursive call is to a parameterless subprogram,
4975 -- then even if we can't statically detect infinite
4976 -- recursion, this is pretty suspicious, and we output a
4977 -- warning. Furthermore, we will try later to detect some
4978 -- cases here at run time by expanding checking code (see
4979 -- Detect_Infinite_Recursion in package Exp_Ch6).
4981 -- If the recursive call is within a handler, do not emit a
4982 -- warning, because this is a common idiom: loop until input
4983 -- is correct, catch illegal input in handler and restart.
4985 if No (First_Formal (Nam))
4986 and then Etype (Nam) = Standard_Void_Type
4987 and then not Error_Posted (N)
4988 and then Nkind (Parent (N)) /= N_Exception_Handler
4990 -- For the case of a procedure call. We give the message
4991 -- only if the call is the first statement in a sequence
4992 -- of statements, or if all previous statements are
4993 -- simple assignments. This is simply a heuristic to
4994 -- decrease false positives, without losing too many good
4995 -- warnings. The idea is that these previous statements
4996 -- may affect global variables the procedure depends on.
4998 if Nkind (N) = N_Procedure_Call_Statement
4999 and then Is_List_Member (N)
5005 while Present (P) loop
5006 if Nkind (P) /= N_Assignment_Statement then
5015 -- Do not give warning if we are in a conditional context
5018 K : constant Node_Kind := Nkind (Parent (N));
5020 if (K = N_Loop_Statement
5021 and then Present (Iteration_Scheme (Parent (N))))
5022 or else K = N_If_Statement
5023 or else K = N_Elsif_Part
5024 or else K = N_Case_Statement_Alternative
5030 -- Here warning is to be issued
5032 Set_Has_Recursive_Call (Nam);
5034 ("?possible infinite recursion!", N);
5036 ("\?Storage_Error may be raised at run time!", N);
5042 Scop := Scope (Scop);
5043 end loop Scope_Loop;
5047 -- If subprogram name is a predefined operator, it was given in
5048 -- functional notation. Replace call node with operator node, so
5049 -- that actuals can be resolved appropriately.
5051 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5052 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5055 elsif Present (Alias (Nam))
5056 and then Is_Predefined_Op (Alias (Nam))
5058 Resolve_Actuals (N, Nam);
5059 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5063 -- Create a transient scope if the resulting type requires it
5065 -- There are several notable exceptions:
5067 -- a) In init procs, the transient scope overhead is not needed, and is
5068 -- even incorrect when the call is a nested initialization call for a
5069 -- component whose expansion may generate adjust calls. However, if the
5070 -- call is some other procedure call within an initialization procedure
5071 -- (for example a call to Create_Task in the init_proc of the task
5072 -- run-time record) a transient scope must be created around this call.
5074 -- b) Enumeration literal pseudo-calls need no transient scope
5076 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5077 -- functions) do not use the secondary stack even though the return
5078 -- type may be unconstrained.
5080 -- d) Calls to a build-in-place function, since such functions may
5081 -- allocate their result directly in a target object, and cases where
5082 -- the result does get allocated in the secondary stack are checked for
5083 -- within the specialized Exp_Ch6 procedures for expanding those
5084 -- build-in-place calls.
5086 -- e) If the subprogram is marked Inline_Always, then even if it returns
5087 -- an unconstrained type the call does not require use of the secondary
5088 -- stack. However, inlining will only take place if the body to inline
5089 -- is already present. It may not be available if e.g. the subprogram is
5090 -- declared in a child instance.
5092 -- If this is an initialization call for a type whose construction
5093 -- uses the secondary stack, and it is not a nested call to initialize
5094 -- a component, we do need to create a transient scope for it. We
5095 -- check for this by traversing the type in Check_Initialization_Call.
5098 and then Has_Pragma_Inline_Always (Nam)
5099 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5100 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5104 elsif Ekind (Nam) = E_Enumeration_Literal
5105 or else Is_Build_In_Place_Function (Nam)
5106 or else Is_Intrinsic_Subprogram (Nam)
5110 elsif Expander_Active
5111 and then Is_Type (Etype (Nam))
5112 and then Requires_Transient_Scope (Etype (Nam))
5114 (not Within_Init_Proc
5116 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5118 Establish_Transient_Scope (N, Sec_Stack => True);
5120 -- If the call appears within the bounds of a loop, it will
5121 -- be rewritten and reanalyzed, nothing left to do here.
5123 if Nkind (N) /= N_Function_Call then
5127 elsif Is_Init_Proc (Nam)
5128 and then not Within_Init_Proc
5130 Check_Initialization_Call (N, Nam);
5133 -- A protected function cannot be called within the definition of the
5134 -- enclosing protected type.
5136 if Is_Protected_Type (Scope (Nam))
5137 and then In_Open_Scopes (Scope (Nam))
5138 and then not Has_Completion (Scope (Nam))
5141 ("& cannot be called before end of protected definition", N, Nam);
5144 -- Propagate interpretation to actuals, and add default expressions
5147 if Present (First_Formal (Nam)) then
5148 Resolve_Actuals (N, Nam);
5150 -- Overloaded literals are rewritten as function calls, for
5151 -- purpose of resolution. After resolution, we can replace
5152 -- the call with the literal itself.
5154 elsif Ekind (Nam) = E_Enumeration_Literal then
5155 Copy_Node (Subp, N);
5156 Resolve_Entity_Name (N, Typ);
5158 -- Avoid validation, since it is a static function call
5160 Generate_Reference (Nam, Subp);
5164 -- If the subprogram is not global, then kill all saved values and
5165 -- checks. This is a bit conservative, since in many cases we could do
5166 -- better, but it is not worth the effort. Similarly, we kill constant
5167 -- values. However we do not need to do this for internal entities
5168 -- (unless they are inherited user-defined subprograms), since they
5169 -- are not in the business of molesting local values.
5171 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5172 -- kill all checks and values for calls to global subprograms. This
5173 -- takes care of the case where an access to a local subprogram is
5174 -- taken, and could be passed directly or indirectly and then called
5175 -- from almost any context.
5177 -- Note: we do not do this step till after resolving the actuals. That
5178 -- way we still take advantage of the current value information while
5179 -- scanning the actuals.
5181 -- We suppress killing values if we are processing the nodes associated
5182 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5183 -- type kills all the values as part of analyzing the code that
5184 -- initializes the dispatch tables.
5186 if Inside_Freezing_Actions = 0
5187 and then (not Is_Library_Level_Entity (Nam)
5188 or else Suppress_Value_Tracking_On_Call
5189 (Nearest_Dynamic_Scope (Current_Scope)))
5190 and then (Comes_From_Source (Nam)
5191 or else (Present (Alias (Nam))
5192 and then Comes_From_Source (Alias (Nam))))
5194 Kill_Current_Values;
5197 -- If we are warning about unread OUT parameters, this is the place to
5198 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5199 -- after the above call to Kill_Current_Values (since that call clears
5200 -- the Last_Assignment field of all local variables).
5202 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5203 and then Comes_From_Source (N)
5204 and then In_Extended_Main_Source_Unit (N)
5211 F := First_Formal (Nam);
5212 A := First_Actual (N);
5213 while Present (F) and then Present (A) loop
5214 if (Ekind (F) = E_Out_Parameter
5215 or else Ekind (F) = E_In_Out_Parameter)
5216 and then Warn_On_Modified_As_Out_Parameter (F)
5217 and then Is_Entity_Name (A)
5218 and then Present (Entity (A))
5219 and then Comes_From_Source (N)
5220 and then Safe_To_Capture_Value (N, Entity (A))
5222 Set_Last_Assignment (Entity (A), A);
5231 -- If the subprogram is a primitive operation, check whether or not
5232 -- it is a correct dispatching call.
5234 if Is_Overloadable (Nam)
5235 and then Is_Dispatching_Operation (Nam)
5237 Check_Dispatching_Call (N);
5239 elsif Ekind (Nam) /= E_Subprogram_Type
5240 and then Is_Abstract_Subprogram (Nam)
5241 and then not In_Instance
5243 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5246 -- If this is a dispatching call, generate the appropriate reference,
5247 -- for better source navigation in GPS.
5249 if Is_Overloadable (Nam)
5250 and then Present (Controlling_Argument (N))
5252 Generate_Reference (Nam, Subp, 'R');
5254 -- Normal case, not a dispatching call
5257 Generate_Reference (Nam, Subp);
5260 if Is_Intrinsic_Subprogram (Nam) then
5261 Check_Intrinsic_Call (N);
5264 -- Check for violation of restriction No_Specific_Termination_Handlers
5265 -- and warn on a potentially blocking call to Abort_Task.
5267 if Is_RTE (Nam, RE_Set_Specific_Handler)
5269 Is_RTE (Nam, RE_Specific_Handler)
5271 Check_Restriction (No_Specific_Termination_Handlers, N);
5273 elsif Is_RTE (Nam, RE_Abort_Task) then
5274 Check_Potentially_Blocking_Operation (N);
5277 -- Issue an error for a call to an eliminated subprogram
5279 Check_For_Eliminated_Subprogram (Subp, Nam);
5281 -- All done, evaluate call and deal with elaboration issues
5284 Check_Elab_Call (N);
5287 -------------------------------
5288 -- Resolve_Character_Literal --
5289 -------------------------------
5291 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5292 B_Typ : constant Entity_Id := Base_Type (Typ);
5296 -- Verify that the character does belong to the type of the context
5298 Set_Etype (N, B_Typ);
5299 Eval_Character_Literal (N);
5301 -- Wide_Wide_Character literals must always be defined, since the set
5302 -- of wide wide character literals is complete, i.e. if a character
5303 -- literal is accepted by the parser, then it is OK for wide wide
5304 -- character (out of range character literals are rejected).
5306 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5309 -- Always accept character literal for type Any_Character, which
5310 -- occurs in error situations and in comparisons of literals, both
5311 -- of which should accept all literals.
5313 elsif B_Typ = Any_Character then
5316 -- For Standard.Character or a type derived from it, check that
5317 -- the literal is in range
5319 elsif Root_Type (B_Typ) = Standard_Character then
5320 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5324 -- For Standard.Wide_Character or a type derived from it, check
5325 -- that the literal is in range
5327 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5328 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5332 -- For Standard.Wide_Wide_Character or a type derived from it, we
5333 -- know the literal is in range, since the parser checked!
5335 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5338 -- If the entity is already set, this has already been resolved in
5339 -- a generic context, or comes from expansion. Nothing else to do.
5341 elsif Present (Entity (N)) then
5344 -- Otherwise we have a user defined character type, and we can use
5345 -- the standard visibility mechanisms to locate the referenced entity
5348 C := Current_Entity (N);
5349 while Present (C) loop
5350 if Etype (C) = B_Typ then
5351 Set_Entity_With_Style_Check (N, C);
5352 Generate_Reference (C, N);
5360 -- If we fall through, then the literal does not match any of the
5361 -- entries of the enumeration type. This isn't just a constraint
5362 -- error situation, it is an illegality (see RM 4.2).
5365 ("character not defined for }", N, First_Subtype (B_Typ));
5366 end Resolve_Character_Literal;
5368 ---------------------------
5369 -- Resolve_Comparison_Op --
5370 ---------------------------
5372 -- Context requires a boolean type, and plays no role in resolution.
5373 -- Processing identical to that for equality operators. The result
5374 -- type is the base type, which matters when pathological subtypes of
5375 -- booleans with limited ranges are used.
5377 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5378 L : constant Node_Id := Left_Opnd (N);
5379 R : constant Node_Id := Right_Opnd (N);
5383 -- If this is an intrinsic operation which is not predefined, use
5384 -- the types of its declared arguments to resolve the possibly
5385 -- overloaded operands. Otherwise the operands are unambiguous and
5386 -- specify the expected type.
5388 if Scope (Entity (N)) /= Standard_Standard then
5389 T := Etype (First_Entity (Entity (N)));
5392 T := Find_Unique_Type (L, R);
5394 if T = Any_Fixed then
5395 T := Unique_Fixed_Point_Type (L);
5399 Set_Etype (N, Base_Type (Typ));
5400 Generate_Reference (T, N, ' ');
5402 if T /= Any_Type then
5404 or else T = Any_Composite
5405 or else T = Any_Character
5407 if T = Any_Character then
5408 Ambiguous_Character (L);
5410 Error_Msg_N ("ambiguous operands for comparison", N);
5413 Set_Etype (N, Any_Type);
5419 Check_Unset_Reference (L);
5420 Check_Unset_Reference (R);
5421 Generate_Operator_Reference (N, T);
5422 Check_Low_Bound_Tested (N);
5423 Eval_Relational_Op (N);
5426 end Resolve_Comparison_Op;
5428 ------------------------------------
5429 -- Resolve_Conditional_Expression --
5430 ------------------------------------
5432 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5433 Condition : constant Node_Id := First (Expressions (N));
5434 Then_Expr : constant Node_Id := Next (Condition);
5435 Else_Expr : constant Node_Id := Next (Then_Expr);
5438 Resolve (Condition, Standard_Boolean);
5439 Resolve (Then_Expr, Typ);
5440 Resolve (Else_Expr, Typ);
5443 Eval_Conditional_Expression (N);
5444 end Resolve_Conditional_Expression;
5446 -----------------------------------------
5447 -- Resolve_Discrete_Subtype_Indication --
5448 -----------------------------------------
5450 procedure Resolve_Discrete_Subtype_Indication
5458 Analyze (Subtype_Mark (N));
5459 S := Entity (Subtype_Mark (N));
5461 if Nkind (Constraint (N)) /= N_Range_Constraint then
5462 Error_Msg_N ("expect range constraint for discrete type", N);
5463 Set_Etype (N, Any_Type);
5466 R := Range_Expression (Constraint (N));
5474 if Base_Type (S) /= Base_Type (Typ) then
5476 ("expect subtype of }", N, First_Subtype (Typ));
5478 -- Rewrite the constraint as a range of Typ
5479 -- to allow compilation to proceed further.
5482 Rewrite (Low_Bound (R),
5483 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5484 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5485 Attribute_Name => Name_First));
5486 Rewrite (High_Bound (R),
5487 Make_Attribute_Reference (Sloc (High_Bound (R)),
5488 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5489 Attribute_Name => Name_First));
5493 Set_Etype (N, Etype (R));
5495 -- Additionally, we must check that the bounds are compatible
5496 -- with the given subtype, which might be different from the
5497 -- type of the context.
5499 Apply_Range_Check (R, S);
5501 -- ??? If the above check statically detects a Constraint_Error
5502 -- it replaces the offending bound(s) of the range R with a
5503 -- Constraint_Error node. When the itype which uses these bounds
5504 -- is frozen the resulting call to Duplicate_Subexpr generates
5505 -- a new temporary for the bounds.
5507 -- Unfortunately there are other itypes that are also made depend
5508 -- on these bounds, so when Duplicate_Subexpr is called they get
5509 -- a forward reference to the newly created temporaries and Gigi
5510 -- aborts on such forward references. This is probably sign of a
5511 -- more fundamental problem somewhere else in either the order of
5512 -- itype freezing or the way certain itypes are constructed.
5514 -- To get around this problem we call Remove_Side_Effects right
5515 -- away if either bounds of R are a Constraint_Error.
5518 L : constant Node_Id := Low_Bound (R);
5519 H : constant Node_Id := High_Bound (R);
5522 if Nkind (L) = N_Raise_Constraint_Error then
5523 Remove_Side_Effects (L);
5526 if Nkind (H) = N_Raise_Constraint_Error then
5527 Remove_Side_Effects (H);
5531 Check_Unset_Reference (Low_Bound (R));
5532 Check_Unset_Reference (High_Bound (R));
5535 end Resolve_Discrete_Subtype_Indication;
5537 -------------------------
5538 -- Resolve_Entity_Name --
5539 -------------------------
5541 -- Used to resolve identifiers and expanded names
5543 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5544 E : constant Entity_Id := Entity (N);
5547 -- If garbage from errors, set to Any_Type and return
5549 if No (E) and then Total_Errors_Detected /= 0 then
5550 Set_Etype (N, Any_Type);
5554 -- Replace named numbers by corresponding literals. Note that this is
5555 -- the one case where Resolve_Entity_Name must reset the Etype, since
5556 -- it is currently marked as universal.
5558 if Ekind (E) = E_Named_Integer then
5560 Eval_Named_Integer (N);
5562 elsif Ekind (E) = E_Named_Real then
5564 Eval_Named_Real (N);
5566 -- Allow use of subtype only if it is a concurrent type where we are
5567 -- currently inside the body. This will eventually be expanded
5568 -- into a call to Self (for tasks) or _object (for protected
5569 -- objects). Any other use of a subtype is invalid.
5571 elsif Is_Type (E) then
5572 if Is_Concurrent_Type (E)
5573 and then In_Open_Scopes (E)
5578 ("invalid use of subtype mark in expression or call", N);
5581 -- Check discriminant use if entity is discriminant in current scope,
5582 -- i.e. discriminant of record or concurrent type currently being
5583 -- analyzed. Uses in corresponding body are unrestricted.
5585 elsif Ekind (E) = E_Discriminant
5586 and then Scope (E) = Current_Scope
5587 and then not Has_Completion (Current_Scope)
5589 Check_Discriminant_Use (N);
5591 -- A parameterless generic function cannot appear in a context that
5592 -- requires resolution.
5594 elsif Ekind (E) = E_Generic_Function then
5595 Error_Msg_N ("illegal use of generic function", N);
5597 elsif Ekind (E) = E_Out_Parameter
5598 and then Ada_Version = Ada_83
5599 and then (Nkind (Parent (N)) in N_Op
5600 or else (Nkind (Parent (N)) = N_Assignment_Statement
5601 and then N = Expression (Parent (N)))
5602 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5604 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5606 -- In all other cases, just do the possible static evaluation
5609 -- A deferred constant that appears in an expression must have
5610 -- a completion, unless it has been removed by in-place expansion
5613 if Ekind (E) = E_Constant
5614 and then Comes_From_Source (E)
5615 and then No (Constant_Value (E))
5616 and then Is_Frozen (Etype (E))
5617 and then not In_Spec_Expression
5618 and then not Is_Imported (E)
5621 if No_Initialization (Parent (E))
5622 or else (Present (Full_View (E))
5623 and then No_Initialization (Parent (Full_View (E))))
5628 "deferred constant is frozen before completion", N);
5632 Eval_Entity_Name (N);
5634 end Resolve_Entity_Name;
5640 procedure Resolve_Entry (Entry_Name : Node_Id) is
5641 Loc : constant Source_Ptr := Sloc (Entry_Name);
5649 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5650 -- If the bounds of the entry family being called depend on task
5651 -- discriminants, build a new index subtype where a discriminant is
5652 -- replaced with the value of the discriminant of the target task.
5653 -- The target task is the prefix of the entry name in the call.
5655 -----------------------
5656 -- Actual_Index_Type --
5657 -----------------------
5659 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5660 Typ : constant Entity_Id := Entry_Index_Type (E);
5661 Tsk : constant Entity_Id := Scope (E);
5662 Lo : constant Node_Id := Type_Low_Bound (Typ);
5663 Hi : constant Node_Id := Type_High_Bound (Typ);
5666 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5667 -- If the bound is given by a discriminant, replace with a reference
5668 -- to the discriminant of the same name in the target task.
5669 -- If the entry name is the target of a requeue statement and the
5670 -- entry is in the current protected object, the bound to be used
5671 -- is the discriminal of the object (see apply_range_checks for
5672 -- details of the transformation).
5674 -----------------------------
5675 -- Actual_Discriminant_Ref --
5676 -----------------------------
5678 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5679 Typ : constant Entity_Id := Etype (Bound);
5683 Remove_Side_Effects (Bound);
5685 if not Is_Entity_Name (Bound)
5686 or else Ekind (Entity (Bound)) /= E_Discriminant
5690 elsif Is_Protected_Type (Tsk)
5691 and then In_Open_Scopes (Tsk)
5692 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5694 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5698 Make_Selected_Component (Loc,
5699 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5700 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5705 end Actual_Discriminant_Ref;
5707 -- Start of processing for Actual_Index_Type
5710 if not Has_Discriminants (Tsk)
5711 or else (not Is_Entity_Name (Lo)
5712 and then not Is_Entity_Name (Hi))
5714 return Entry_Index_Type (E);
5717 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5718 Set_Etype (New_T, Base_Type (Typ));
5719 Set_Size_Info (New_T, Typ);
5720 Set_RM_Size (New_T, RM_Size (Typ));
5721 Set_Scalar_Range (New_T,
5722 Make_Range (Sloc (Entry_Name),
5723 Low_Bound => Actual_Discriminant_Ref (Lo),
5724 High_Bound => Actual_Discriminant_Ref (Hi)));
5728 end Actual_Index_Type;
5730 -- Start of processing of Resolve_Entry
5733 -- Find name of entry being called, and resolve prefix of name
5734 -- with its own type. The prefix can be overloaded, and the name
5735 -- and signature of the entry must be taken into account.
5737 if Nkind (Entry_Name) = N_Indexed_Component then
5739 -- Case of dealing with entry family within the current tasks
5741 E_Name := Prefix (Entry_Name);
5744 E_Name := Entry_Name;
5747 if Is_Entity_Name (E_Name) then
5748 -- Entry call to an entry (or entry family) in the current task.
5749 -- This is legal even though the task will deadlock. Rewrite as
5750 -- call to current task.
5752 -- This can also be a call to an entry in an enclosing task.
5753 -- If this is a single task, we have to retrieve its name,
5754 -- because the scope of the entry is the task type, not the
5755 -- object. If the enclosing task is a task type, the identity
5756 -- of the task is given by its own self variable.
5758 -- Finally this can be a requeue on an entry of the same task
5759 -- or protected object.
5761 S := Scope (Entity (E_Name));
5763 for J in reverse 0 .. Scope_Stack.Last loop
5765 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5766 and then not Comes_From_Source (S)
5768 -- S is an enclosing task or protected object. The concurrent
5769 -- declaration has been converted into a type declaration, and
5770 -- the object itself has an object declaration that follows
5771 -- the type in the same declarative part.
5773 Tsk := Next_Entity (S);
5774 while Etype (Tsk) /= S loop
5781 elsif S = Scope_Stack.Table (J).Entity then
5783 -- Call to current task. Will be transformed into call to Self
5791 Make_Selected_Component (Loc,
5792 Prefix => New_Occurrence_Of (S, Loc),
5794 New_Occurrence_Of (Entity (E_Name), Loc));
5795 Rewrite (E_Name, New_N);
5798 elsif Nkind (Entry_Name) = N_Selected_Component
5799 and then Is_Overloaded (Prefix (Entry_Name))
5801 -- Use the entry name (which must be unique at this point) to
5802 -- find the prefix that returns the corresponding task type or
5806 Pref : constant Node_Id := Prefix (Entry_Name);
5807 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5812 Get_First_Interp (Pref, I, It);
5813 while Present (It.Typ) loop
5814 if Scope (Ent) = It.Typ then
5815 Set_Etype (Pref, It.Typ);
5819 Get_Next_Interp (I, It);
5824 if Nkind (Entry_Name) = N_Selected_Component then
5825 Resolve (Prefix (Entry_Name));
5827 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5828 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5829 Resolve (Prefix (Prefix (Entry_Name)));
5830 Index := First (Expressions (Entry_Name));
5831 Resolve (Index, Entry_Index_Type (Nam));
5833 -- Up to this point the expression could have been the actual
5834 -- in a simple entry call, and be given by a named association.
5836 if Nkind (Index) = N_Parameter_Association then
5837 Error_Msg_N ("expect expression for entry index", Index);
5839 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5844 ------------------------
5845 -- Resolve_Entry_Call --
5846 ------------------------
5848 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5849 Entry_Name : constant Node_Id := Name (N);
5850 Loc : constant Source_Ptr := Sloc (Entry_Name);
5852 First_Named : Node_Id;
5859 -- We kill all checks here, because it does not seem worth the
5860 -- effort to do anything better, an entry call is a big operation.
5864 -- Processing of the name is similar for entry calls and protected
5865 -- operation calls. Once the entity is determined, we can complete
5866 -- the resolution of the actuals.
5868 -- The selector may be overloaded, in the case of a protected object
5869 -- with overloaded functions. The type of the context is used for
5872 if Nkind (Entry_Name) = N_Selected_Component
5873 and then Is_Overloaded (Selector_Name (Entry_Name))
5874 and then Typ /= Standard_Void_Type
5881 Get_First_Interp (Selector_Name (Entry_Name), I, It);
5882 while Present (It.Typ) loop
5883 if Covers (Typ, It.Typ) then
5884 Set_Entity (Selector_Name (Entry_Name), It.Nam);
5885 Set_Etype (Entry_Name, It.Typ);
5887 Generate_Reference (It.Typ, N, ' ');
5890 Get_Next_Interp (I, It);
5895 Resolve_Entry (Entry_Name);
5897 if Nkind (Entry_Name) = N_Selected_Component then
5899 -- Simple entry call
5901 Nam := Entity (Selector_Name (Entry_Name));
5902 Obj := Prefix (Entry_Name);
5903 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
5905 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5907 -- Call to member of entry family
5909 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5910 Obj := Prefix (Prefix (Entry_Name));
5911 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
5914 -- We cannot in general check the maximum depth of protected entry
5915 -- calls at compile time. But we can tell that any protected entry
5916 -- call at all violates a specified nesting depth of zero.
5918 if Is_Protected_Type (Scope (Nam)) then
5919 Check_Restriction (Max_Entry_Queue_Length, N);
5922 -- Use context type to disambiguate a protected function that can be
5923 -- called without actuals and that returns an array type, and where
5924 -- the argument list may be an indexing of the returned value.
5926 if Ekind (Nam) = E_Function
5927 and then Needs_No_Actuals (Nam)
5928 and then Present (Parameter_Associations (N))
5930 ((Is_Array_Type (Etype (Nam))
5931 and then Covers (Typ, Component_Type (Etype (Nam))))
5933 or else (Is_Access_Type (Etype (Nam))
5934 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5935 and then Covers (Typ,
5936 Component_Type (Designated_Type (Etype (Nam))))))
5939 Index_Node : Node_Id;
5943 Make_Indexed_Component (Loc,
5945 Make_Function_Call (Loc,
5946 Name => Relocate_Node (Entry_Name)),
5947 Expressions => Parameter_Associations (N));
5949 -- Since we are correcting a node classification error made by
5950 -- the parser, we call Replace rather than Rewrite.
5952 Replace (N, Index_Node);
5953 Set_Etype (Prefix (N), Etype (Nam));
5955 Resolve_Indexed_Component (N, Typ);
5960 -- The operation name may have been overloaded. Order the actuals
5961 -- according to the formals of the resolved entity, and set the
5962 -- return type to that of the operation.
5965 Normalize_Actuals (N, Nam, False, Norm_OK);
5966 pragma Assert (Norm_OK);
5967 Set_Etype (N, Etype (Nam));
5970 Resolve_Actuals (N, Nam);
5971 Generate_Reference (Nam, Entry_Name);
5973 if Ekind (Nam) = E_Entry
5974 or else Ekind (Nam) = E_Entry_Family
5976 Check_Potentially_Blocking_Operation (N);
5979 -- Verify that a procedure call cannot masquerade as an entry
5980 -- call where an entry call is expected.
5982 if Ekind (Nam) = E_Procedure then
5983 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5984 and then N = Entry_Call_Statement (Parent (N))
5986 Error_Msg_N ("entry call required in select statement", N);
5988 elsif Nkind (Parent (N)) = N_Triggering_Alternative
5989 and then N = Triggering_Statement (Parent (N))
5991 Error_Msg_N ("triggering statement cannot be procedure call", N);
5993 elsif Ekind (Scope (Nam)) = E_Task_Type
5994 and then not In_Open_Scopes (Scope (Nam))
5996 Error_Msg_N ("task has no entry with this name", Entry_Name);
6000 -- After resolution, entry calls and protected procedure calls
6001 -- are changed into entry calls, for expansion. The structure
6002 -- of the node does not change, so it can safely be done in place.
6003 -- Protected function calls must keep their structure because they
6004 -- are subexpressions.
6006 if Ekind (Nam) /= E_Function then
6008 -- A protected operation that is not a function may modify the
6009 -- corresponding object, and cannot apply to a constant.
6010 -- If this is an internal call, the prefix is the type itself.
6012 if Is_Protected_Type (Scope (Nam))
6013 and then not Is_Variable (Obj)
6014 and then (not Is_Entity_Name (Obj)
6015 or else not Is_Type (Entity (Obj)))
6018 ("prefix of protected procedure or entry call must be variable",
6022 Actuals := Parameter_Associations (N);
6023 First_Named := First_Named_Actual (N);
6026 Make_Entry_Call_Statement (Loc,
6028 Parameter_Associations => Actuals));
6030 Set_First_Named_Actual (N, First_Named);
6031 Set_Analyzed (N, True);
6033 -- Protected functions can return on the secondary stack, in which
6034 -- case we must trigger the transient scope mechanism.
6036 elsif Expander_Active
6037 and then Requires_Transient_Scope (Etype (Nam))
6039 Establish_Transient_Scope (N, Sec_Stack => True);
6041 end Resolve_Entry_Call;
6043 -------------------------
6044 -- Resolve_Equality_Op --
6045 -------------------------
6047 -- Both arguments must have the same type, and the boolean context
6048 -- does not participate in the resolution. The first pass verifies
6049 -- that the interpretation is not ambiguous, and the type of the left
6050 -- argument is correctly set, or is Any_Type in case of ambiguity.
6051 -- If both arguments are strings or aggregates, allocators, or Null,
6052 -- they are ambiguous even though they carry a single (universal) type.
6053 -- Diagnose this case here.
6055 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6056 L : constant Node_Id := Left_Opnd (N);
6057 R : constant Node_Id := Right_Opnd (N);
6058 T : Entity_Id := Find_Unique_Type (L, R);
6060 function Find_Unique_Access_Type return Entity_Id;
6061 -- In the case of allocators, make a last-ditch attempt to find a single
6062 -- access type with the right designated type. This is semantically
6063 -- dubious, and of no interest to any real code, but c48008a makes it
6066 -----------------------------
6067 -- Find_Unique_Access_Type --
6068 -----------------------------
6070 function Find_Unique_Access_Type return Entity_Id is
6076 if Ekind (Etype (R)) = E_Allocator_Type then
6077 Acc := Designated_Type (Etype (R));
6078 elsif Ekind (Etype (L)) = E_Allocator_Type then
6079 Acc := Designated_Type (Etype (L));
6085 while S /= Standard_Standard loop
6086 E := First_Entity (S);
6087 while Present (E) loop
6089 and then Is_Access_Type (E)
6090 and then Ekind (E) /= E_Allocator_Type
6091 and then Designated_Type (E) = Base_Type (Acc)
6103 end Find_Unique_Access_Type;
6105 -- Start of processing for Resolve_Equality_Op
6108 Set_Etype (N, Base_Type (Typ));
6109 Generate_Reference (T, N, ' ');
6111 if T = Any_Fixed then
6112 T := Unique_Fixed_Point_Type (L);
6115 if T /= Any_Type then
6117 or else T = Any_Composite
6118 or else T = Any_Character
6120 if T = Any_Character then
6121 Ambiguous_Character (L);
6123 Error_Msg_N ("ambiguous operands for equality", N);
6126 Set_Etype (N, Any_Type);
6129 elsif T = Any_Access
6130 or else Ekind (T) = E_Allocator_Type
6131 or else Ekind (T) = E_Access_Attribute_Type
6133 T := Find_Unique_Access_Type;
6136 Error_Msg_N ("ambiguous operands for equality", N);
6137 Set_Etype (N, Any_Type);
6145 -- If the unique type is a class-wide type then it will be expanded
6146 -- into a dispatching call to the predefined primitive. Therefore we
6147 -- check here for potential violation of such restriction.
6149 if Is_Class_Wide_Type (T) then
6150 Check_Restriction (No_Dispatching_Calls, N);
6153 if Warn_On_Redundant_Constructs
6154 and then Comes_From_Source (N)
6155 and then Is_Entity_Name (R)
6156 and then Entity (R) = Standard_True
6157 and then Comes_From_Source (R)
6159 Error_Msg_N ("?comparison with True is redundant!", R);
6162 Check_Unset_Reference (L);
6163 Check_Unset_Reference (R);
6164 Generate_Operator_Reference (N, T);
6165 Check_Low_Bound_Tested (N);
6167 -- If this is an inequality, it may be the implicit inequality
6168 -- created for a user-defined operation, in which case the corres-
6169 -- ponding equality operation is not intrinsic, and the operation
6170 -- cannot be constant-folded. Else fold.
6172 if Nkind (N) = N_Op_Eq
6173 or else Comes_From_Source (Entity (N))
6174 or else Ekind (Entity (N)) = E_Operator
6175 or else Is_Intrinsic_Subprogram
6176 (Corresponding_Equality (Entity (N)))
6178 Eval_Relational_Op (N);
6180 elsif Nkind (N) = N_Op_Ne
6181 and then Is_Abstract_Subprogram (Entity (N))
6183 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6186 -- Ada 2005: If one operand is an anonymous access type, convert
6187 -- the other operand to it, to ensure that the underlying types
6188 -- match in the back-end. Same for access_to_subprogram, and the
6189 -- conversion verifies that the types are subtype conformant.
6191 -- We apply the same conversion in the case one of the operands is
6192 -- a private subtype of the type of the other.
6194 -- Why the Expander_Active test here ???
6198 (Ekind (T) = E_Anonymous_Access_Type
6199 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6200 or else Is_Private_Type (T))
6202 if Etype (L) /= T then
6204 Make_Unchecked_Type_Conversion (Sloc (L),
6205 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6206 Expression => Relocate_Node (L)));
6207 Analyze_And_Resolve (L, T);
6210 if (Etype (R)) /= T then
6212 Make_Unchecked_Type_Conversion (Sloc (R),
6213 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6214 Expression => Relocate_Node (R)));
6215 Analyze_And_Resolve (R, T);
6219 end Resolve_Equality_Op;
6221 ----------------------------------
6222 -- Resolve_Explicit_Dereference --
6223 ----------------------------------
6225 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6226 Loc : constant Source_Ptr := Sloc (N);
6228 P : constant Node_Id := Prefix (N);
6233 Check_Fully_Declared_Prefix (Typ, P);
6235 if Is_Overloaded (P) then
6237 -- Use the context type to select the prefix that has the correct
6240 Get_First_Interp (P, I, It);
6241 while Present (It.Typ) loop
6242 exit when Is_Access_Type (It.Typ)
6243 and then Covers (Typ, Designated_Type (It.Typ));
6244 Get_Next_Interp (I, It);
6247 if Present (It.Typ) then
6248 Resolve (P, It.Typ);
6250 -- If no interpretation covers the designated type of the prefix,
6251 -- this is the pathological case where not all implementations of
6252 -- the prefix allow the interpretation of the node as a call. Now
6253 -- that the expected type is known, Remove other interpretations
6254 -- from prefix, rewrite it as a call, and resolve again, so that
6255 -- the proper call node is generated.
6257 Get_First_Interp (P, I, It);
6258 while Present (It.Typ) loop
6259 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6263 Get_Next_Interp (I, It);
6267 Make_Function_Call (Loc,
6269 Make_Explicit_Dereference (Loc,
6271 Parameter_Associations => New_List);
6273 Save_Interps (N, New_N);
6275 Analyze_And_Resolve (N, Typ);
6279 Set_Etype (N, Designated_Type (It.Typ));
6285 if Is_Access_Type (Etype (P)) then
6286 Apply_Access_Check (N);
6289 -- If the designated type is a packed unconstrained array type, and the
6290 -- explicit dereference is not in the context of an attribute reference,
6291 -- then we must compute and set the actual subtype, since it is needed
6292 -- by Gigi. The reason we exclude the attribute case is that this is
6293 -- handled fine by Gigi, and in fact we use such attributes to build the
6294 -- actual subtype. We also exclude generated code (which builds actual
6295 -- subtypes directly if they are needed).
6297 if Is_Array_Type (Etype (N))
6298 and then Is_Packed (Etype (N))
6299 and then not Is_Constrained (Etype (N))
6300 and then Nkind (Parent (N)) /= N_Attribute_Reference
6301 and then Comes_From_Source (N)
6303 Set_Etype (N, Get_Actual_Subtype (N));
6306 -- Note: there is no Eval processing required for an explicit deference,
6307 -- because the type is known to be an allocators, and allocator
6308 -- expressions can never be static.
6310 end Resolve_Explicit_Dereference;
6312 -------------------------------
6313 -- Resolve_Indexed_Component --
6314 -------------------------------
6316 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6317 Name : constant Node_Id := Prefix (N);
6319 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6323 if Is_Overloaded (Name) then
6325 -- Use the context type to select the prefix that yields the correct
6331 I1 : Interp_Index := 0;
6332 P : constant Node_Id := Prefix (N);
6333 Found : Boolean := False;
6336 Get_First_Interp (P, I, It);
6337 while Present (It.Typ) loop
6338 if (Is_Array_Type (It.Typ)
6339 and then Covers (Typ, Component_Type (It.Typ)))
6340 or else (Is_Access_Type (It.Typ)
6341 and then Is_Array_Type (Designated_Type (It.Typ))
6343 (Typ, Component_Type (Designated_Type (It.Typ))))
6346 It := Disambiguate (P, I1, I, Any_Type);
6348 if It = No_Interp then
6349 Error_Msg_N ("ambiguous prefix for indexing", N);
6355 Array_Type := It.Typ;
6361 Array_Type := It.Typ;
6366 Get_Next_Interp (I, It);
6371 Array_Type := Etype (Name);
6374 Resolve (Name, Array_Type);
6375 Array_Type := Get_Actual_Subtype_If_Available (Name);
6377 -- If prefix is access type, dereference to get real array type.
6378 -- Note: we do not apply an access check because the expander always
6379 -- introduces an explicit dereference, and the check will happen there.
6381 if Is_Access_Type (Array_Type) then
6382 Array_Type := Designated_Type (Array_Type);
6385 -- If name was overloaded, set component type correctly now
6386 -- If a misplaced call to an entry family (which has no index types)
6387 -- return. Error will be diagnosed from calling context.
6389 if Is_Array_Type (Array_Type) then
6390 Set_Etype (N, Component_Type (Array_Type));
6395 Index := First_Index (Array_Type);
6396 Expr := First (Expressions (N));
6398 -- The prefix may have resolved to a string literal, in which case its
6399 -- etype has a special representation. This is only possible currently
6400 -- if the prefix is a static concatenation, written in functional
6403 if Ekind (Array_Type) = E_String_Literal_Subtype then
6404 Resolve (Expr, Standard_Positive);
6407 while Present (Index) and Present (Expr) loop
6408 Resolve (Expr, Etype (Index));
6409 Check_Unset_Reference (Expr);
6411 if Is_Scalar_Type (Etype (Expr)) then
6412 Apply_Scalar_Range_Check (Expr, Etype (Index));
6414 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6422 -- Do not generate the warning on suspicious index if we are analyzing
6423 -- package Ada.Tags; otherwise we will report the warning with the
6424 -- Prims_Ptr field of the dispatch table.
6426 if Scope (Etype (Prefix (N))) = Standard_Standard
6428 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6431 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6432 Eval_Indexed_Component (N);
6434 end Resolve_Indexed_Component;
6436 -----------------------------
6437 -- Resolve_Integer_Literal --
6438 -----------------------------
6440 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6443 Eval_Integer_Literal (N);
6444 end Resolve_Integer_Literal;
6446 --------------------------------
6447 -- Resolve_Intrinsic_Operator --
6448 --------------------------------
6450 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6451 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6458 while Scope (Op) /= Standard_Standard loop
6460 pragma Assert (Present (Op));
6464 Set_Is_Overloaded (N, False);
6466 -- If the operand type is private, rewrite with suitable conversions on
6467 -- the operands and the result, to expose the proper underlying numeric
6470 if Is_Private_Type (Typ) then
6471 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6473 if Nkind (N) = N_Op_Expon then
6474 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6476 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6479 Save_Interps (Left_Opnd (N), Expression (Arg1));
6480 Save_Interps (Right_Opnd (N), Expression (Arg2));
6482 Set_Left_Opnd (N, Arg1);
6483 Set_Right_Opnd (N, Arg2);
6485 Set_Etype (N, Btyp);
6486 Rewrite (N, Unchecked_Convert_To (Typ, N));
6489 elsif Typ /= Etype (Left_Opnd (N))
6490 or else Typ /= Etype (Right_Opnd (N))
6492 -- Add explicit conversion where needed, and save interpretations
6493 -- in case operands are overloaded.
6495 Arg1 := Convert_To (Typ, Left_Opnd (N));
6496 Arg2 := Convert_To (Typ, Right_Opnd (N));
6498 if Nkind (Arg1) = N_Type_Conversion then
6499 Save_Interps (Left_Opnd (N), Expression (Arg1));
6501 Save_Interps (Left_Opnd (N), Arg1);
6504 if Nkind (Arg2) = N_Type_Conversion then
6505 Save_Interps (Right_Opnd (N), Expression (Arg2));
6507 Save_Interps (Right_Opnd (N), Arg2);
6510 Rewrite (Left_Opnd (N), Arg1);
6511 Rewrite (Right_Opnd (N), Arg2);
6514 Resolve_Arithmetic_Op (N, Typ);
6517 Resolve_Arithmetic_Op (N, Typ);
6519 end Resolve_Intrinsic_Operator;
6521 --------------------------------------
6522 -- Resolve_Intrinsic_Unary_Operator --
6523 --------------------------------------
6525 procedure Resolve_Intrinsic_Unary_Operator
6529 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6535 while Scope (Op) /= Standard_Standard loop
6537 pragma Assert (Present (Op));
6542 if Is_Private_Type (Typ) then
6543 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6544 Save_Interps (Right_Opnd (N), Expression (Arg2));
6546 Set_Right_Opnd (N, Arg2);
6548 Set_Etype (N, Btyp);
6549 Rewrite (N, Unchecked_Convert_To (Typ, N));
6553 Resolve_Unary_Op (N, Typ);
6555 end Resolve_Intrinsic_Unary_Operator;
6557 ------------------------
6558 -- Resolve_Logical_Op --
6559 ------------------------
6561 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6563 N_Opr : constant Node_Kind := Nkind (N);
6566 -- Predefined operations on scalar types yield the base type. On the
6567 -- other hand, logical operations on arrays yield the type of the
6568 -- arguments (and the context).
6570 if Is_Array_Type (Typ) then
6573 B_Typ := Base_Type (Typ);
6576 -- The following test is required because the operands of the operation
6577 -- may be literals, in which case the resulting type appears to be
6578 -- compatible with a signed integer type, when in fact it is compatible
6579 -- only with modular types. If the context itself is universal, the
6580 -- operation is illegal.
6582 if not Valid_Boolean_Arg (Typ) then
6583 Error_Msg_N ("invalid context for logical operation", N);
6584 Set_Etype (N, Any_Type);
6587 elsif Typ = Any_Modular then
6589 ("no modular type available in this context", N);
6590 Set_Etype (N, Any_Type);
6592 elsif Is_Modular_Integer_Type (Typ)
6593 and then Etype (Left_Opnd (N)) = Universal_Integer
6594 and then Etype (Right_Opnd (N)) = Universal_Integer
6596 Check_For_Visible_Operator (N, B_Typ);
6599 Resolve (Left_Opnd (N), B_Typ);
6600 Resolve (Right_Opnd (N), B_Typ);
6602 Check_Unset_Reference (Left_Opnd (N));
6603 Check_Unset_Reference (Right_Opnd (N));
6605 Set_Etype (N, B_Typ);
6606 Generate_Operator_Reference (N, B_Typ);
6607 Eval_Logical_Op (N);
6609 -- Check for violation of restriction No_Direct_Boolean_Operators
6610 -- if the operator was not eliminated by the Eval_Logical_Op call.
6612 if Nkind (N) = N_Opr
6613 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
6615 Check_Restriction (No_Direct_Boolean_Operators, N);
6617 end Resolve_Logical_Op;
6619 ---------------------------
6620 -- Resolve_Membership_Op --
6621 ---------------------------
6623 -- The context can only be a boolean type, and does not determine
6624 -- the arguments. Arguments should be unambiguous, but the preference
6625 -- rule for universal types applies.
6627 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6628 pragma Warnings (Off, Typ);
6630 L : constant Node_Id := Left_Opnd (N);
6631 R : constant Node_Id := Right_Opnd (N);
6635 if L = Error or else R = Error then
6639 if not Is_Overloaded (R)
6641 (Etype (R) = Universal_Integer or else
6642 Etype (R) = Universal_Real)
6643 and then Is_Overloaded (L)
6647 -- Ada 2005 (AI-251): Give support to the following case:
6649 -- type I is interface;
6650 -- type T is tagged ...
6652 -- function Test (O : I'Class) is
6654 -- return O in T'Class.
6657 -- In this case we have nothing else to do; the membership test will be
6658 -- done at run-time.
6660 elsif Ada_Version >= Ada_05
6661 and then Is_Class_Wide_Type (Etype (L))
6662 and then Is_Interface (Etype (L))
6663 and then Is_Class_Wide_Type (Etype (R))
6664 and then not Is_Interface (Etype (R))
6669 T := Intersect_Types (L, R);
6673 Check_Unset_Reference (L);
6675 if Nkind (R) = N_Range
6676 and then not Is_Scalar_Type (T)
6678 Error_Msg_N ("scalar type required for range", R);
6681 if Is_Entity_Name (R) then
6682 Freeze_Expression (R);
6685 Check_Unset_Reference (R);
6688 Eval_Membership_Op (N);
6689 end Resolve_Membership_Op;
6695 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6696 Loc : constant Source_Ptr := Sloc (N);
6699 -- Handle restriction against anonymous null access values This
6700 -- restriction can be turned off using -gnatdj.
6702 -- Ada 2005 (AI-231): Remove restriction
6704 if Ada_Version < Ada_05
6705 and then not Debug_Flag_J
6706 and then Ekind (Typ) = E_Anonymous_Access_Type
6707 and then Comes_From_Source (N)
6709 -- In the common case of a call which uses an explicitly null
6710 -- value for an access parameter, give specialized error message.
6712 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6716 ("null is not allowed as argument for an access parameter", N);
6718 -- Standard message for all other cases (are there any?)
6722 ("null cannot be of an anonymous access type", N);
6726 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6727 -- assignment to a null-excluding object
6729 if Ada_Version >= Ada_05
6730 and then Can_Never_Be_Null (Typ)
6731 and then Nkind (Parent (N)) = N_Assignment_Statement
6733 if not Inside_Init_Proc then
6735 (Compile_Time_Constraint_Error (N,
6736 "(Ada 2005) null not allowed in null-excluding objects?"),
6737 Make_Raise_Constraint_Error (Loc,
6738 Reason => CE_Access_Check_Failed));
6741 Make_Raise_Constraint_Error (Loc,
6742 Reason => CE_Access_Check_Failed));
6746 -- In a distributed context, null for a remote access to subprogram
6747 -- may need to be replaced with a special record aggregate. In this
6748 -- case, return after having done the transformation.
6750 if (Ekind (Typ) = E_Record_Type
6751 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6752 and then Remote_AST_Null_Value (N, Typ)
6757 -- The null literal takes its type from the context
6762 -----------------------
6763 -- Resolve_Op_Concat --
6764 -----------------------
6766 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6768 -- We wish to avoid deep recursion, because concatenations are often
6769 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6770 -- operands nonrecursively until we find something that is not a simple
6771 -- concatenation (A in this case). We resolve that, and then walk back
6772 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6773 -- to do the rest of the work at each level. The Parent pointers allow
6774 -- us to avoid recursion, and thus avoid running out of memory. See also
6775 -- Sem_Ch4.Analyze_Concatenation, where a similar hack is used.
6781 -- The following code is equivalent to:
6783 -- Resolve_Op_Concat_First (NN, Typ);
6784 -- Resolve_Op_Concat_Arg (N, ...);
6785 -- Resolve_Op_Concat_Rest (N, Typ);
6787 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6788 -- operand is a concatenation.
6790 -- Walk down left operands
6793 Resolve_Op_Concat_First (NN, Typ);
6794 Op1 := Left_Opnd (NN);
6795 exit when not (Nkind (Op1) = N_Op_Concat
6796 and then not Is_Array_Type (Component_Type (Typ))
6797 and then Entity (Op1) = Entity (NN));
6801 -- Now (given the above example) NN is A&B and Op1 is A
6803 -- First resolve Op1 ...
6805 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6807 -- ... then walk NN back up until we reach N (where we started), calling
6808 -- Resolve_Op_Concat_Rest along the way.
6811 Resolve_Op_Concat_Rest (NN, Typ);
6815 end Resolve_Op_Concat;
6817 ---------------------------
6818 -- Resolve_Op_Concat_Arg --
6819 ---------------------------
6821 procedure Resolve_Op_Concat_Arg
6827 Btyp : constant Entity_Id := Base_Type (Typ);
6832 or else (not Is_Overloaded (Arg)
6833 and then Etype (Arg) /= Any_Composite
6834 and then Covers (Component_Type (Typ), Etype (Arg)))
6836 Resolve (Arg, Component_Type (Typ));
6838 Resolve (Arg, Btyp);
6841 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6842 if Nkind (Arg) = N_Aggregate
6843 and then Is_Composite_Type (Component_Type (Typ))
6845 if Is_Private_Type (Component_Type (Typ)) then
6846 Resolve (Arg, Btyp);
6848 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6849 Set_Etype (Arg, Any_Type);
6853 if Is_Overloaded (Arg)
6854 and then Has_Compatible_Type (Arg, Typ)
6855 and then Etype (Arg) /= Any_Type
6863 Get_First_Interp (Arg, I, It);
6865 Get_Next_Interp (I, It);
6867 -- Special-case the error message when the overloading is
6868 -- caused by a function that yields an array and can be
6869 -- called without parameters.
6871 if It.Nam = Func then
6872 Error_Msg_Sloc := Sloc (Func);
6873 Error_Msg_N ("ambiguous call to function#", Arg);
6875 ("\\interpretation as call yields&", Arg, Typ);
6877 ("\\interpretation as indexing of call yields&",
6878 Arg, Component_Type (Typ));
6882 ("ambiguous operand for concatenation!", Arg);
6883 Get_First_Interp (Arg, I, It);
6884 while Present (It.Nam) loop
6885 Error_Msg_Sloc := Sloc (It.Nam);
6887 if Base_Type (It.Typ) = Base_Type (Typ)
6888 or else Base_Type (It.Typ) =
6889 Base_Type (Component_Type (Typ))
6891 Error_Msg_N ("\\possible interpretation#", Arg);
6894 Get_Next_Interp (I, It);
6900 Resolve (Arg, Component_Type (Typ));
6902 if Nkind (Arg) = N_String_Literal then
6903 Set_Etype (Arg, Component_Type (Typ));
6906 if Arg = Left_Opnd (N) then
6907 Set_Is_Component_Left_Opnd (N);
6909 Set_Is_Component_Right_Opnd (N);
6914 Resolve (Arg, Btyp);
6917 Check_Unset_Reference (Arg);
6918 end Resolve_Op_Concat_Arg;
6920 -----------------------------
6921 -- Resolve_Op_Concat_First --
6922 -----------------------------
6924 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
6925 Btyp : constant Entity_Id := Base_Type (Typ);
6926 Op1 : constant Node_Id := Left_Opnd (N);
6927 Op2 : constant Node_Id := Right_Opnd (N);
6930 -- The parser folds an enormous sequence of concatenations of string
6931 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
6932 -- in the right. If the expression resolves to a predefined "&"
6933 -- operator, all is well. Otherwise, the parser's folding is wrong, so
6934 -- we give an error. See P_Simple_Expression in Par.Ch4.
6936 if Nkind (Op2) = N_String_Literal
6937 and then Is_Folded_In_Parser (Op2)
6938 and then Ekind (Entity (N)) = E_Function
6940 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
6941 and then String_Length (Strval (Op1)) = 0);
6942 Error_Msg_N ("too many user-defined concatenations", N);
6946 Set_Etype (N, Btyp);
6948 if Is_Limited_Composite (Btyp) then
6949 Error_Msg_N ("concatenation not available for limited array", N);
6950 Explain_Limited_Type (Btyp, N);
6952 end Resolve_Op_Concat_First;
6954 ----------------------------
6955 -- Resolve_Op_Concat_Rest --
6956 ----------------------------
6958 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
6959 Op1 : constant Node_Id := Left_Opnd (N);
6960 Op2 : constant Node_Id := Right_Opnd (N);
6963 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
6965 Generate_Operator_Reference (N, Typ);
6967 if Is_String_Type (Typ) then
6968 Eval_Concatenation (N);
6971 -- If this is not a static concatenation, but the result is a
6972 -- string type (and not an array of strings) ensure that static
6973 -- string operands have their subtypes properly constructed.
6975 if Nkind (N) /= N_String_Literal
6976 and then Is_Character_Type (Component_Type (Typ))
6978 Set_String_Literal_Subtype (Op1, Typ);
6979 Set_String_Literal_Subtype (Op2, Typ);
6981 end Resolve_Op_Concat_Rest;
6983 ----------------------
6984 -- Resolve_Op_Expon --
6985 ----------------------
6987 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
6988 B_Typ : constant Entity_Id := Base_Type (Typ);
6991 -- Catch attempts to do fixed-point exponentiation with universal
6992 -- operands, which is a case where the illegality is not caught during
6993 -- normal operator analysis.
6995 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
6996 Error_Msg_N ("exponentiation not available for fixed point", N);
7000 if Comes_From_Source (N)
7001 and then Ekind (Entity (N)) = E_Function
7002 and then Is_Imported (Entity (N))
7003 and then Is_Intrinsic_Subprogram (Entity (N))
7005 Resolve_Intrinsic_Operator (N, Typ);
7009 if Etype (Left_Opnd (N)) = Universal_Integer
7010 or else Etype (Left_Opnd (N)) = Universal_Real
7012 Check_For_Visible_Operator (N, B_Typ);
7015 -- We do the resolution using the base type, because intermediate values
7016 -- in expressions always are of the base type, not a subtype of it.
7018 Resolve (Left_Opnd (N), B_Typ);
7019 Resolve (Right_Opnd (N), Standard_Integer);
7021 Check_Unset_Reference (Left_Opnd (N));
7022 Check_Unset_Reference (Right_Opnd (N));
7024 Set_Etype (N, B_Typ);
7025 Generate_Operator_Reference (N, B_Typ);
7028 -- Set overflow checking bit. Much cleverer code needed here eventually
7029 -- and perhaps the Resolve routines should be separated for the various
7030 -- arithmetic operations, since they will need different processing. ???
7032 if Nkind (N) in N_Op then
7033 if not Overflow_Checks_Suppressed (Etype (N)) then
7034 Enable_Overflow_Check (N);
7037 end Resolve_Op_Expon;
7039 --------------------
7040 -- Resolve_Op_Not --
7041 --------------------
7043 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7046 function Parent_Is_Boolean return Boolean;
7047 -- This function determines if the parent node is a boolean operator
7048 -- or operation (comparison op, membership test, or short circuit form)
7049 -- and the not in question is the left operand of this operation.
7050 -- Note that if the not is in parens, then false is returned.
7052 -----------------------
7053 -- Parent_Is_Boolean --
7054 -----------------------
7056 function Parent_Is_Boolean return Boolean is
7058 if Paren_Count (N) /= 0 then
7062 case Nkind (Parent (N)) is
7077 return Left_Opnd (Parent (N)) = N;
7083 end Parent_Is_Boolean;
7085 -- Start of processing for Resolve_Op_Not
7088 -- Predefined operations on scalar types yield the base type. On the
7089 -- other hand, logical operations on arrays yield the type of the
7090 -- arguments (and the context).
7092 if Is_Array_Type (Typ) then
7095 B_Typ := Base_Type (Typ);
7098 -- Straightforward case of incorrect arguments
7100 if not Valid_Boolean_Arg (Typ) then
7101 Error_Msg_N ("invalid operand type for operator&", N);
7102 Set_Etype (N, Any_Type);
7105 -- Special case of probable missing parens
7107 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7108 if Parent_Is_Boolean then
7110 ("operand of not must be enclosed in parentheses",
7114 ("no modular type available in this context", N);
7117 Set_Etype (N, Any_Type);
7120 -- OK resolution of not
7123 -- Warn if non-boolean types involved. This is a case like not a < b
7124 -- where a and b are modular, where we will get (not a) < b and most
7125 -- likely not (a < b) was intended.
7127 if Warn_On_Questionable_Missing_Parens
7128 and then not Is_Boolean_Type (Typ)
7129 and then Parent_Is_Boolean
7131 Error_Msg_N ("?not expression should be parenthesized here!", N);
7134 -- Warn on double negation if checking redundant constructs
7136 if Warn_On_Redundant_Constructs
7137 and then Comes_From_Source (N)
7138 and then Comes_From_Source (Right_Opnd (N))
7139 and then Root_Type (Typ) = Standard_Boolean
7140 and then Nkind (Right_Opnd (N)) = N_Op_Not
7142 Error_Msg_N ("redundant double negation?", N);
7145 -- Complete resolution and evaluation of NOT
7147 Resolve (Right_Opnd (N), B_Typ);
7148 Check_Unset_Reference (Right_Opnd (N));
7149 Set_Etype (N, B_Typ);
7150 Generate_Operator_Reference (N, B_Typ);
7155 -----------------------------
7156 -- Resolve_Operator_Symbol --
7157 -----------------------------
7159 -- Nothing to be done, all resolved already
7161 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7162 pragma Warnings (Off, N);
7163 pragma Warnings (Off, Typ);
7167 end Resolve_Operator_Symbol;
7169 ----------------------------------
7170 -- Resolve_Qualified_Expression --
7171 ----------------------------------
7173 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7174 pragma Warnings (Off, Typ);
7176 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7177 Expr : constant Node_Id := Expression (N);
7180 Resolve (Expr, Target_Typ);
7182 -- A qualified expression requires an exact match of the type,
7183 -- class-wide matching is not allowed. However, if the qualifying
7184 -- type is specific and the expression has a class-wide type, it
7185 -- may still be okay, since it can be the result of the expansion
7186 -- of a call to a dispatching function, so we also have to check
7187 -- class-wideness of the type of the expression's original node.
7189 if (Is_Class_Wide_Type (Target_Typ)
7191 (Is_Class_Wide_Type (Etype (Expr))
7192 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7193 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7195 Wrong_Type (Expr, Target_Typ);
7198 -- If the target type is unconstrained, then we reset the type of
7199 -- the result from the type of the expression. For other cases, the
7200 -- actual subtype of the expression is the target type.
7202 if Is_Composite_Type (Target_Typ)
7203 and then not Is_Constrained (Target_Typ)
7205 Set_Etype (N, Etype (Expr));
7208 Eval_Qualified_Expression (N);
7209 end Resolve_Qualified_Expression;
7215 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7216 L : constant Node_Id := Low_Bound (N);
7217 H : constant Node_Id := High_Bound (N);
7224 Check_Unset_Reference (L);
7225 Check_Unset_Reference (H);
7227 -- We have to check the bounds for being within the base range as
7228 -- required for a non-static context. Normally this is automatic and
7229 -- done as part of evaluating expressions, but the N_Range node is an
7230 -- exception, since in GNAT we consider this node to be a subexpression,
7231 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7232 -- this, but that would put the test on the main evaluation path for
7235 Check_Non_Static_Context (L);
7236 Check_Non_Static_Context (H);
7238 -- Check for an ambiguous range over character literals. This will
7239 -- happen with a membership test involving only literals.
7241 if Typ = Any_Character then
7242 Ambiguous_Character (L);
7243 Set_Etype (N, Any_Type);
7247 -- If bounds are static, constant-fold them, so size computations
7248 -- are identical between front-end and back-end. Do not perform this
7249 -- transformation while analyzing generic units, as type information
7250 -- would then be lost when reanalyzing the constant node in the
7253 if Is_Discrete_Type (Typ) and then Expander_Active then
7254 if Is_OK_Static_Expression (L) then
7255 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7258 if Is_OK_Static_Expression (H) then
7259 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7264 --------------------------
7265 -- Resolve_Real_Literal --
7266 --------------------------
7268 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7269 Actual_Typ : constant Entity_Id := Etype (N);
7272 -- Special processing for fixed-point literals to make sure that the
7273 -- value is an exact multiple of small where this is required. We
7274 -- skip this for the universal real case, and also for generic types.
7276 if Is_Fixed_Point_Type (Typ)
7277 and then Typ /= Universal_Fixed
7278 and then Typ /= Any_Fixed
7279 and then not Is_Generic_Type (Typ)
7282 Val : constant Ureal := Realval (N);
7283 Cintr : constant Ureal := Val / Small_Value (Typ);
7284 Cint : constant Uint := UR_Trunc (Cintr);
7285 Den : constant Uint := Norm_Den (Cintr);
7289 -- Case of literal is not an exact multiple of the Small
7293 -- For a source program literal for a decimal fixed-point
7294 -- type, this is statically illegal (RM 4.9(36)).
7296 if Is_Decimal_Fixed_Point_Type (Typ)
7297 and then Actual_Typ = Universal_Real
7298 and then Comes_From_Source (N)
7300 Error_Msg_N ("value has extraneous low order digits", N);
7303 -- Generate a warning if literal from source
7305 if Is_Static_Expression (N)
7306 and then Warn_On_Bad_Fixed_Value
7309 ("?static fixed-point value is not a multiple of Small!",
7313 -- Replace literal by a value that is the exact representation
7314 -- of a value of the type, i.e. a multiple of the small value,
7315 -- by truncation, since Machine_Rounds is false for all GNAT
7316 -- fixed-point types (RM 4.9(38)).
7318 Stat := Is_Static_Expression (N);
7320 Make_Real_Literal (Sloc (N),
7321 Realval => Small_Value (Typ) * Cint));
7323 Set_Is_Static_Expression (N, Stat);
7326 -- In all cases, set the corresponding integer field
7328 Set_Corresponding_Integer_Value (N, Cint);
7332 -- Now replace the actual type by the expected type as usual
7335 Eval_Real_Literal (N);
7336 end Resolve_Real_Literal;
7338 -----------------------
7339 -- Resolve_Reference --
7340 -----------------------
7342 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7343 P : constant Node_Id := Prefix (N);
7346 -- Replace general access with specific type
7348 if Ekind (Etype (N)) = E_Allocator_Type then
7349 Set_Etype (N, Base_Type (Typ));
7352 Resolve (P, Designated_Type (Etype (N)));
7354 -- If we are taking the reference of a volatile entity, then treat
7355 -- it as a potential modification of this entity. This is much too
7356 -- conservative, but is necessary because remove side effects can
7357 -- result in transformations of normal assignments into reference
7358 -- sequences that otherwise fail to notice the modification.
7360 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7361 Note_Possible_Modification (P, Sure => False);
7363 end Resolve_Reference;
7365 --------------------------------
7366 -- Resolve_Selected_Component --
7367 --------------------------------
7369 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7371 Comp1 : Entity_Id := Empty; -- prevent junk warning
7372 P : constant Node_Id := Prefix (N);
7373 S : constant Node_Id := Selector_Name (N);
7374 T : Entity_Id := Etype (P);
7376 I1 : Interp_Index := 0; -- prevent junk warning
7381 function Init_Component return Boolean;
7382 -- Check whether this is the initialization of a component within an
7383 -- init proc (by assignment or call to another init proc). If true,
7384 -- there is no need for a discriminant check.
7386 --------------------
7387 -- Init_Component --
7388 --------------------
7390 function Init_Component return Boolean is
7392 return Inside_Init_Proc
7393 and then Nkind (Prefix (N)) = N_Identifier
7394 and then Chars (Prefix (N)) = Name_uInit
7395 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7398 -- Start of processing for Resolve_Selected_Component
7401 if Is_Overloaded (P) then
7403 -- Use the context type to select the prefix that has a selector
7404 -- of the correct name and type.
7407 Get_First_Interp (P, I, It);
7409 Search : while Present (It.Typ) loop
7410 if Is_Access_Type (It.Typ) then
7411 T := Designated_Type (It.Typ);
7416 if Is_Record_Type (T) then
7418 -- The visible components of a class-wide type are those of
7421 if Is_Class_Wide_Type (T) then
7425 Comp := First_Entity (T);
7426 while Present (Comp) loop
7427 if Chars (Comp) = Chars (S)
7428 and then Covers (Etype (Comp), Typ)
7437 It := Disambiguate (P, I1, I, Any_Type);
7439 if It = No_Interp then
7441 ("ambiguous prefix for selected component", N);
7448 -- There may be an implicit dereference. Retrieve
7449 -- designated record type.
7451 if Is_Access_Type (It1.Typ) then
7452 T := Designated_Type (It1.Typ);
7457 if Scope (Comp1) /= T then
7459 -- Resolution chooses the new interpretation.
7460 -- Find the component with the right name.
7462 Comp1 := First_Entity (T);
7463 while Present (Comp1)
7464 and then Chars (Comp1) /= Chars (S)
7466 Comp1 := Next_Entity (Comp1);
7475 Comp := Next_Entity (Comp);
7480 Get_Next_Interp (I, It);
7483 Resolve (P, It1.Typ);
7485 Set_Entity_With_Style_Check (S, Comp1);
7488 -- Resolve prefix with its type
7493 -- Generate cross-reference. We needed to wait until full overloading
7494 -- resolution was complete to do this, since otherwise we can't tell if
7495 -- we are an Lvalue of not.
7497 if May_Be_Lvalue (N) then
7498 Generate_Reference (Entity (S), S, 'm');
7500 Generate_Reference (Entity (S), S, 'r');
7503 -- If prefix is an access type, the node will be transformed into an
7504 -- explicit dereference during expansion. The type of the node is the
7505 -- designated type of that of the prefix.
7507 if Is_Access_Type (Etype (P)) then
7508 T := Designated_Type (Etype (P));
7509 Check_Fully_Declared_Prefix (T, P);
7514 if Has_Discriminants (T)
7515 and then (Ekind (Entity (S)) = E_Component
7517 Ekind (Entity (S)) = E_Discriminant)
7518 and then Present (Original_Record_Component (Entity (S)))
7519 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7520 and then Present (Discriminant_Checking_Func
7521 (Original_Record_Component (Entity (S))))
7522 and then not Discriminant_Checks_Suppressed (T)
7523 and then not Init_Component
7525 Set_Do_Discriminant_Check (N);
7528 if Ekind (Entity (S)) = E_Void then
7529 Error_Msg_N ("premature use of component", S);
7532 -- If the prefix is a record conversion, this may be a renamed
7533 -- discriminant whose bounds differ from those of the original
7534 -- one, so we must ensure that a range check is performed.
7536 if Nkind (P) = N_Type_Conversion
7537 and then Ekind (Entity (S)) = E_Discriminant
7538 and then Is_Discrete_Type (Typ)
7540 Set_Etype (N, Base_Type (Typ));
7543 -- Note: No Eval processing is required, because the prefix is of a
7544 -- record type, or protected type, and neither can possibly be static.
7546 end Resolve_Selected_Component;
7552 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7553 B_Typ : constant Entity_Id := Base_Type (Typ);
7554 L : constant Node_Id := Left_Opnd (N);
7555 R : constant Node_Id := Right_Opnd (N);
7558 -- We do the resolution using the base type, because intermediate values
7559 -- in expressions always are of the base type, not a subtype of it.
7562 Resolve (R, Standard_Natural);
7564 Check_Unset_Reference (L);
7565 Check_Unset_Reference (R);
7567 Set_Etype (N, B_Typ);
7568 Generate_Operator_Reference (N, B_Typ);
7572 ---------------------------
7573 -- Resolve_Short_Circuit --
7574 ---------------------------
7576 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7577 B_Typ : constant Entity_Id := Base_Type (Typ);
7578 L : constant Node_Id := Left_Opnd (N);
7579 R : constant Node_Id := Right_Opnd (N);
7585 -- Check for issuing warning for always False assert/check, this happens
7586 -- when assertions are turned off, in which case the pragma Assert/Check
7587 -- was transformed into:
7589 -- if False and then <condition> then ...
7591 -- and we detect this pattern
7593 if Warn_On_Assertion_Failure
7594 and then Is_Entity_Name (R)
7595 and then Entity (R) = Standard_False
7596 and then Nkind (Parent (N)) = N_If_Statement
7597 and then Nkind (N) = N_And_Then
7598 and then Is_Entity_Name (L)
7599 and then Entity (L) = Standard_False
7602 Orig : constant Node_Id := Original_Node (Parent (N));
7605 if Nkind (Orig) = N_Pragma
7606 and then Pragma_Name (Orig) = Name_Assert
7608 -- Don't want to warn if original condition is explicit False
7611 Expr : constant Node_Id :=
7614 (First (Pragma_Argument_Associations (Orig))));
7616 if Is_Entity_Name (Expr)
7617 and then Entity (Expr) = Standard_False
7621 -- Issue warning. Note that we don't want to make this
7622 -- an unconditional warning, because if the assert is
7623 -- within deleted code we do not want the warning. But
7624 -- we do not want the deletion of the IF/AND-THEN to
7625 -- take this message with it. We achieve this by making
7626 -- sure that the expanded code points to the Sloc of
7627 -- the expression, not the original pragma.
7629 Error_Msg_N ("?assertion would fail at run-time", Orig);
7633 -- Similar processing for Check pragma
7635 elsif Nkind (Orig) = N_Pragma
7636 and then Pragma_Name (Orig) = Name_Check
7638 -- Don't want to warn if original condition is explicit False
7641 Expr : constant Node_Id :=
7645 (Pragma_Argument_Associations (Orig)))));
7647 if Is_Entity_Name (Expr)
7648 and then Entity (Expr) = Standard_False
7652 Error_Msg_N ("?check would fail at run-time", Orig);
7659 -- Continue with processing of short circuit
7661 Check_Unset_Reference (L);
7662 Check_Unset_Reference (R);
7664 Set_Etype (N, B_Typ);
7665 Eval_Short_Circuit (N);
7666 end Resolve_Short_Circuit;
7672 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7673 Name : constant Node_Id := Prefix (N);
7674 Drange : constant Node_Id := Discrete_Range (N);
7675 Array_Type : Entity_Id := Empty;
7679 if Is_Overloaded (Name) then
7681 -- Use the context type to select the prefix that yields the
7682 -- correct array type.
7686 I1 : Interp_Index := 0;
7688 P : constant Node_Id := Prefix (N);
7689 Found : Boolean := False;
7692 Get_First_Interp (P, I, It);
7693 while Present (It.Typ) loop
7694 if (Is_Array_Type (It.Typ)
7695 and then Covers (Typ, It.Typ))
7696 or else (Is_Access_Type (It.Typ)
7697 and then Is_Array_Type (Designated_Type (It.Typ))
7698 and then Covers (Typ, Designated_Type (It.Typ)))
7701 It := Disambiguate (P, I1, I, Any_Type);
7703 if It = No_Interp then
7704 Error_Msg_N ("ambiguous prefix for slicing", N);
7709 Array_Type := It.Typ;
7714 Array_Type := It.Typ;
7719 Get_Next_Interp (I, It);
7724 Array_Type := Etype (Name);
7727 Resolve (Name, Array_Type);
7729 if Is_Access_Type (Array_Type) then
7730 Apply_Access_Check (N);
7731 Array_Type := Designated_Type (Array_Type);
7733 -- If the prefix is an access to an unconstrained array, we must use
7734 -- the actual subtype of the object to perform the index checks. The
7735 -- object denoted by the prefix is implicit in the node, so we build
7736 -- an explicit representation for it in order to compute the actual
7739 if not Is_Constrained (Array_Type) then
7740 Remove_Side_Effects (Prefix (N));
7743 Obj : constant Node_Id :=
7744 Make_Explicit_Dereference (Sloc (N),
7745 Prefix => New_Copy_Tree (Prefix (N)));
7747 Set_Etype (Obj, Array_Type);
7748 Set_Parent (Obj, Parent (N));
7749 Array_Type := Get_Actual_Subtype (Obj);
7753 elsif Is_Entity_Name (Name)
7754 or else (Nkind (Name) = N_Function_Call
7755 and then not Is_Constrained (Etype (Name)))
7757 Array_Type := Get_Actual_Subtype (Name);
7759 -- If the name is a selected component that depends on discriminants,
7760 -- build an actual subtype for it. This can happen only when the name
7761 -- itself is overloaded; otherwise the actual subtype is created when
7762 -- the selected component is analyzed.
7764 elsif Nkind (Name) = N_Selected_Component
7765 and then Full_Analysis
7766 and then Depends_On_Discriminant (First_Index (Array_Type))
7769 Act_Decl : constant Node_Id :=
7770 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7772 Insert_Action (N, Act_Decl);
7773 Array_Type := Defining_Identifier (Act_Decl);
7777 -- If name was overloaded, set slice type correctly now
7779 Set_Etype (N, Array_Type);
7781 -- If the range is specified by a subtype mark, no resolution is
7782 -- necessary. Else resolve the bounds, and apply needed checks.
7784 if not Is_Entity_Name (Drange) then
7785 Index := First_Index (Array_Type);
7786 Resolve (Drange, Base_Type (Etype (Index)));
7788 if Nkind (Drange) = N_Range
7790 -- Do not apply the range check to nodes associated with the
7791 -- frontend expansion of the dispatch table. We first check
7792 -- if Ada.Tags is already loaded to void the addition of an
7793 -- undesired dependence on such run-time unit.
7798 (RTU_Loaded (Ada_Tags)
7799 and then Nkind (Prefix (N)) = N_Selected_Component
7800 and then Present (Entity (Selector_Name (Prefix (N))))
7801 and then Entity (Selector_Name (Prefix (N))) =
7802 RTE_Record_Component (RE_Prims_Ptr)))
7804 Apply_Range_Check (Drange, Etype (Index));
7808 Set_Slice_Subtype (N);
7810 if Nkind (Drange) = N_Range then
7811 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7812 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7818 ----------------------------
7819 -- Resolve_String_Literal --
7820 ----------------------------
7822 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7823 C_Typ : constant Entity_Id := Component_Type (Typ);
7824 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7825 Loc : constant Source_Ptr := Sloc (N);
7826 Str : constant String_Id := Strval (N);
7827 Strlen : constant Nat := String_Length (Str);
7828 Subtype_Id : Entity_Id;
7829 Need_Check : Boolean;
7832 -- For a string appearing in a concatenation, defer creation of the
7833 -- string_literal_subtype until the end of the resolution of the
7834 -- concatenation, because the literal may be constant-folded away. This
7835 -- is a useful optimization for long concatenation expressions.
7837 -- If the string is an aggregate built for a single character (which
7838 -- happens in a non-static context) or a is null string to which special
7839 -- checks may apply, we build the subtype. Wide strings must also get a
7840 -- string subtype if they come from a one character aggregate. Strings
7841 -- generated by attributes might be static, but it is often hard to
7842 -- determine whether the enclosing context is static, so we generate
7843 -- subtypes for them as well, thus losing some rarer optimizations ???
7844 -- Same for strings that come from a static conversion.
7847 (Strlen = 0 and then Typ /= Standard_String)
7848 or else Nkind (Parent (N)) /= N_Op_Concat
7849 or else (N /= Left_Opnd (Parent (N))
7850 and then N /= Right_Opnd (Parent (N)))
7851 or else ((Typ = Standard_Wide_String
7852 or else Typ = Standard_Wide_Wide_String)
7853 and then Nkind (Original_Node (N)) /= N_String_Literal);
7855 -- If the resolving type is itself a string literal subtype, we
7856 -- can just reuse it, since there is no point in creating another.
7858 if Ekind (Typ) = E_String_Literal_Subtype then
7861 elsif Nkind (Parent (N)) = N_Op_Concat
7862 and then not Need_Check
7863 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7864 N_Attribute_Reference,
7865 N_Qualified_Expression,
7870 -- Otherwise we must create a string literal subtype. Note that the
7871 -- whole idea of string literal subtypes is simply to avoid the need
7872 -- for building a full fledged array subtype for each literal.
7875 Set_String_Literal_Subtype (N, Typ);
7876 Subtype_Id := Etype (N);
7879 if Nkind (Parent (N)) /= N_Op_Concat
7882 Set_Etype (N, Subtype_Id);
7883 Eval_String_Literal (N);
7886 if Is_Limited_Composite (Typ)
7887 or else Is_Private_Composite (Typ)
7889 Error_Msg_N ("string literal not available for private array", N);
7890 Set_Etype (N, Any_Type);
7894 -- The validity of a null string has been checked in the
7895 -- call to Eval_String_Literal.
7900 -- Always accept string literal with component type Any_Character, which
7901 -- occurs in error situations and in comparisons of literals, both of
7902 -- which should accept all literals.
7904 elsif R_Typ = Any_Character then
7907 -- If the type is bit-packed, then we always transform the string
7908 -- literal into a full fledged aggregate.
7910 elsif Is_Bit_Packed_Array (Typ) then
7913 -- Deal with cases of Wide_Wide_String, Wide_String, and String
7916 -- For Standard.Wide_Wide_String, or any other type whose component
7917 -- type is Standard.Wide_Wide_Character, we know that all the
7918 -- characters in the string must be acceptable, since the parser
7919 -- accepted the characters as valid character literals.
7921 if R_Typ = Standard_Wide_Wide_Character then
7924 -- For the case of Standard.String, or any other type whose component
7925 -- type is Standard.Character, we must make sure that there are no
7926 -- wide characters in the string, i.e. that it is entirely composed
7927 -- of characters in range of type Character.
7929 -- If the string literal is the result of a static concatenation, the
7930 -- test has already been performed on the components, and need not be
7933 elsif R_Typ = Standard_Character
7934 and then Nkind (Original_Node (N)) /= N_Op_Concat
7936 for J in 1 .. Strlen loop
7937 if not In_Character_Range (Get_String_Char (Str, J)) then
7939 -- If we are out of range, post error. This is one of the
7940 -- very few places that we place the flag in the middle of
7941 -- a token, right under the offending wide character.
7944 ("literal out of range of type Standard.Character",
7945 Source_Ptr (Int (Loc) + J));
7950 -- For the case of Standard.Wide_String, or any other type whose
7951 -- component type is Standard.Wide_Character, we must make sure that
7952 -- there are no wide characters in the string, i.e. that it is
7953 -- entirely composed of characters in range of type Wide_Character.
7955 -- If the string literal is the result of a static concatenation,
7956 -- the test has already been performed on the components, and need
7959 elsif R_Typ = Standard_Wide_Character
7960 and then Nkind (Original_Node (N)) /= N_Op_Concat
7962 for J in 1 .. Strlen loop
7963 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
7965 -- If we are out of range, post error. This is one of the
7966 -- very few places that we place the flag in the middle of
7967 -- a token, right under the offending wide character.
7969 -- This is not quite right, because characters in general
7970 -- will take more than one character position ???
7973 ("literal out of range of type Standard.Wide_Character",
7974 Source_Ptr (Int (Loc) + J));
7979 -- If the root type is not a standard character, then we will convert
7980 -- the string into an aggregate and will let the aggregate code do
7981 -- the checking. Standard Wide_Wide_Character is also OK here.
7987 -- See if the component type of the array corresponding to the string
7988 -- has compile time known bounds. If yes we can directly check
7989 -- whether the evaluation of the string will raise constraint error.
7990 -- Otherwise we need to transform the string literal into the
7991 -- corresponding character aggregate and let the aggregate
7992 -- code do the checking.
7994 if Is_Standard_Character_Type (R_Typ) then
7996 -- Check for the case of full range, where we are definitely OK
7998 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8002 -- Here the range is not the complete base type range, so check
8005 Comp_Typ_Lo : constant Node_Id :=
8006 Type_Low_Bound (Component_Type (Typ));
8007 Comp_Typ_Hi : constant Node_Id :=
8008 Type_High_Bound (Component_Type (Typ));
8013 if Compile_Time_Known_Value (Comp_Typ_Lo)
8014 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8016 for J in 1 .. Strlen loop
8017 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8019 if Char_Val < Expr_Value (Comp_Typ_Lo)
8020 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8022 Apply_Compile_Time_Constraint_Error
8023 (N, "character out of range?", CE_Range_Check_Failed,
8024 Loc => Source_Ptr (Int (Loc) + J));
8034 -- If we got here we meed to transform the string literal into the
8035 -- equivalent qualified positional array aggregate. This is rather
8036 -- heavy artillery for this situation, but it is hard work to avoid.
8039 Lits : constant List_Id := New_List;
8040 P : Source_Ptr := Loc + 1;
8044 -- Build the character literals, we give them source locations that
8045 -- correspond to the string positions, which is a bit tricky given
8046 -- the possible presence of wide character escape sequences.
8048 for J in 1 .. Strlen loop
8049 C := Get_String_Char (Str, J);
8050 Set_Character_Literal_Name (C);
8053 Make_Character_Literal (P,
8055 Char_Literal_Value => UI_From_CC (C)));
8057 if In_Character_Range (C) then
8060 -- Should we have a call to Skip_Wide here ???
8068 Make_Qualified_Expression (Loc,
8069 Subtype_Mark => New_Reference_To (Typ, Loc),
8071 Make_Aggregate (Loc, Expressions => Lits)));
8073 Analyze_And_Resolve (N, Typ);
8075 end Resolve_String_Literal;
8077 -----------------------------
8078 -- Resolve_Subprogram_Info --
8079 -----------------------------
8081 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8084 end Resolve_Subprogram_Info;
8086 -----------------------------
8087 -- Resolve_Type_Conversion --
8088 -----------------------------
8090 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8091 Conv_OK : constant Boolean := Conversion_OK (N);
8092 Operand : constant Node_Id := Expression (N);
8093 Operand_Typ : constant Entity_Id := Etype (Operand);
8094 Target_Typ : constant Entity_Id := Etype (N);
8101 and then not Valid_Conversion (N, Target_Typ, Operand)
8106 if Etype (Operand) = Any_Fixed then
8108 -- Mixed-mode operation involving a literal. Context must be a fixed
8109 -- type which is applied to the literal subsequently.
8111 if Is_Fixed_Point_Type (Typ) then
8112 Set_Etype (Operand, Universal_Real);
8114 elsif Is_Numeric_Type (Typ)
8115 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8116 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8118 Etype (Left_Opnd (Operand)) = Universal_Real)
8120 -- Return if expression is ambiguous
8122 if Unique_Fixed_Point_Type (N) = Any_Type then
8125 -- If nothing else, the available fixed type is Duration
8128 Set_Etype (Operand, Standard_Duration);
8131 -- Resolve the real operand with largest available precision
8133 if Etype (Right_Opnd (Operand)) = Universal_Real then
8134 Rop := New_Copy_Tree (Right_Opnd (Operand));
8136 Rop := New_Copy_Tree (Left_Opnd (Operand));
8139 Resolve (Rop, Universal_Real);
8141 -- If the operand is a literal (it could be a non-static and
8142 -- illegal exponentiation) check whether the use of Duration
8143 -- is potentially inaccurate.
8145 if Nkind (Rop) = N_Real_Literal
8146 and then Realval (Rop) /= Ureal_0
8147 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8150 ("?universal real operand can only " &
8151 "be interpreted as Duration!",
8154 ("\?precision will be lost in the conversion!", Rop);
8157 elsif Is_Numeric_Type (Typ)
8158 and then Nkind (Operand) in N_Op
8159 and then Unique_Fixed_Point_Type (N) /= Any_Type
8161 Set_Etype (Operand, Standard_Duration);
8164 Error_Msg_N ("invalid context for mixed mode operation", N);
8165 Set_Etype (Operand, Any_Type);
8172 -- Note: we do the Eval_Type_Conversion call before applying the
8173 -- required checks for a subtype conversion. This is important,
8174 -- since both are prepared under certain circumstances to change
8175 -- the type conversion to a constraint error node, but in the case
8176 -- of Eval_Type_Conversion this may reflect an illegality in the
8177 -- static case, and we would miss the illegality (getting only a
8178 -- warning message), if we applied the type conversion checks first.
8180 Eval_Type_Conversion (N);
8182 -- Even when evaluation is not possible, we may be able to simplify
8183 -- the conversion or its expression. This needs to be done before
8184 -- applying checks, since otherwise the checks may use the original
8185 -- expression and defeat the simplifications. This is specifically
8186 -- the case for elimination of the floating-point Truncation
8187 -- attribute in float-to-int conversions.
8189 Simplify_Type_Conversion (N);
8191 -- If after evaluation we still have a type conversion, then we
8192 -- may need to apply checks required for a subtype conversion.
8194 -- Skip these type conversion checks if universal fixed operands
8195 -- operands involved, since range checks are handled separately for
8196 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8198 if Nkind (N) = N_Type_Conversion
8199 and then not Is_Generic_Type (Root_Type (Target_Typ))
8200 and then Target_Typ /= Universal_Fixed
8201 and then Operand_Typ /= Universal_Fixed
8203 Apply_Type_Conversion_Checks (N);
8206 -- Issue warning for conversion of simple object to its own type
8207 -- We have to test the original nodes, since they may have been
8208 -- rewritten by various optimizations.
8210 Orig_N := Original_Node (N);
8212 if Warn_On_Redundant_Constructs
8213 and then Comes_From_Source (Orig_N)
8214 and then Nkind (Orig_N) = N_Type_Conversion
8215 and then not In_Instance
8217 Orig_N := Original_Node (Expression (Orig_N));
8218 Orig_T := Target_Typ;
8220 -- If the node is part of a larger expression, the Target_Type
8221 -- may not be the original type of the node if the context is a
8222 -- condition. Recover original type to see if conversion is needed.
8224 if Is_Boolean_Type (Orig_T)
8225 and then Nkind (Parent (N)) in N_Op
8227 Orig_T := Etype (Parent (N));
8230 if Is_Entity_Name (Orig_N)
8232 (Etype (Entity (Orig_N)) = Orig_T
8234 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8235 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8237 Error_Msg_Node_2 := Orig_T;
8239 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8243 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8244 -- No need to perform any interface conversion if the type of the
8245 -- expression coincides with the target type.
8247 if Ada_Version >= Ada_05
8248 and then Expander_Active
8249 and then Operand_Typ /= Target_Typ
8252 Opnd : Entity_Id := Operand_Typ;
8253 Target : Entity_Id := Target_Typ;
8256 if Is_Access_Type (Opnd) then
8257 Opnd := Directly_Designated_Type (Opnd);
8260 if Is_Access_Type (Target_Typ) then
8261 Target := Directly_Designated_Type (Target);
8264 if Opnd = Target then
8267 -- Conversion from interface type
8269 elsif Is_Interface (Opnd) then
8271 -- Ada 2005 (AI-217): Handle entities from limited views
8273 if From_With_Type (Opnd) then
8274 Error_Msg_Qual_Level := 99;
8275 Error_Msg_NE ("missing with-clause on package &", N,
8276 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8278 ("type conversions require visibility of the full view",
8281 elsif From_With_Type (Target)
8283 (Is_Access_Type (Target_Typ)
8284 and then Present (Non_Limited_View (Etype (Target))))
8286 Error_Msg_Qual_Level := 99;
8287 Error_Msg_NE ("missing with-clause on package &", N,
8288 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8290 ("type conversions require visibility of the full view",
8294 Expand_Interface_Conversion (N, Is_Static => False);
8297 -- Conversion to interface type
8299 elsif Is_Interface (Target) then
8303 if Ekind (Opnd) = E_Protected_Subtype
8304 or else Ekind (Opnd) = E_Task_Subtype
8306 Opnd := Etype (Opnd);
8309 if not Interface_Present_In_Ancestor
8313 if Is_Class_Wide_Type (Opnd) then
8315 -- The static analysis is not enough to know if the
8316 -- interface is implemented or not. Hence we must pass
8317 -- the work to the expander to generate code to evaluate
8318 -- the conversion at run-time.
8320 Expand_Interface_Conversion (N, Is_Static => False);
8323 Error_Msg_Name_1 := Chars (Etype (Target));
8324 Error_Msg_Name_2 := Chars (Opnd);
8326 ("wrong interface conversion (% is not a progenitor " &
8331 Expand_Interface_Conversion (N);
8336 end Resolve_Type_Conversion;
8338 ----------------------
8339 -- Resolve_Unary_Op --
8340 ----------------------
8342 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8343 B_Typ : constant Entity_Id := Base_Type (Typ);
8344 R : constant Node_Id := Right_Opnd (N);
8350 -- Deal with intrinsic unary operators
8352 if Comes_From_Source (N)
8353 and then Ekind (Entity (N)) = E_Function
8354 and then Is_Imported (Entity (N))
8355 and then Is_Intrinsic_Subprogram (Entity (N))
8357 Resolve_Intrinsic_Unary_Operator (N, Typ);
8361 -- Deal with universal cases
8363 if Etype (R) = Universal_Integer
8365 Etype (R) = Universal_Real
8367 Check_For_Visible_Operator (N, B_Typ);
8370 Set_Etype (N, B_Typ);
8373 -- Generate warning for expressions like abs (x mod 2)
8375 if Warn_On_Redundant_Constructs
8376 and then Nkind (N) = N_Op_Abs
8378 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8380 if OK and then Hi >= Lo and then Lo >= 0 then
8382 ("?abs applied to known non-negative value has no effect", N);
8386 -- Deal with reference generation
8388 Check_Unset_Reference (R);
8389 Generate_Operator_Reference (N, B_Typ);
8392 -- Set overflow checking bit. Much cleverer code needed here eventually
8393 -- and perhaps the Resolve routines should be separated for the various
8394 -- arithmetic operations, since they will need different processing ???
8396 if Nkind (N) in N_Op then
8397 if not Overflow_Checks_Suppressed (Etype (N)) then
8398 Enable_Overflow_Check (N);
8402 -- Generate warning for expressions like -5 mod 3 for integers. No
8403 -- need to worry in the floating-point case, since parens do not affect
8404 -- the result so there is no point in giving in a warning.
8407 Norig : constant Node_Id := Original_Node (N);
8416 if Warn_On_Questionable_Missing_Parens
8417 and then Comes_From_Source (Norig)
8418 and then Is_Integer_Type (Typ)
8419 and then Nkind (Norig) = N_Op_Minus
8421 Rorig := Original_Node (Right_Opnd (Norig));
8423 -- We are looking for cases where the right operand is not
8424 -- parenthesized, and is a binary operator, multiply, divide, or
8425 -- mod. These are the cases where the grouping can affect results.
8427 if Paren_Count (Rorig) = 0
8428 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8430 -- For mod, we always give the warning, since the value is
8431 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8432 -- (5 mod 315)). But for the other cases, the only concern is
8433 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8434 -- overflows, but (-2) * 64 does not). So we try to give the
8435 -- message only when overflow is possible.
8437 if Nkind (Rorig) /= N_Op_Mod
8438 and then Compile_Time_Known_Value (R)
8440 Val := Expr_Value (R);
8442 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8443 HB := Expr_Value (Type_High_Bound (Typ));
8445 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8448 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8449 LB := Expr_Value (Type_Low_Bound (Typ));
8451 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8454 -- Note that the test below is deliberately excluding
8455 -- the largest negative number, since that is a potentially
8456 -- troublesome case (e.g. -2 * x, where the result is the
8457 -- largest negative integer has an overflow with 2 * x).
8459 if Val > LB and then Val <= HB then
8464 -- For the multiplication case, the only case we have to worry
8465 -- about is when (-a)*b is exactly the largest negative number
8466 -- so that -(a*b) can cause overflow. This can only happen if
8467 -- a is a power of 2, and more generally if any operand is a
8468 -- constant that is not a power of 2, then the parentheses
8469 -- cannot affect whether overflow occurs. We only bother to
8470 -- test the left most operand
8472 -- Loop looking at left operands for one that has known value
8475 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8476 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8477 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8479 -- Operand value of 0 or 1 skips warning
8484 -- Otherwise check power of 2, if power of 2, warn, if
8485 -- anything else, skip warning.
8488 while Lval /= 2 loop
8489 if Lval mod 2 = 1 then
8500 -- Keep looking at left operands
8502 Opnd := Left_Opnd (Opnd);
8505 -- For rem or "/" we can only have a problematic situation
8506 -- if the divisor has a value of minus one or one. Otherwise
8507 -- overflow is impossible (divisor > 1) or we have a case of
8508 -- division by zero in any case.
8510 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8511 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8512 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8517 -- If we fall through warning should be issued
8520 ("?unary minus expression should be parenthesized here!", N);
8524 end Resolve_Unary_Op;
8526 ----------------------------------
8527 -- Resolve_Unchecked_Expression --
8528 ----------------------------------
8530 procedure Resolve_Unchecked_Expression
8535 Resolve (Expression (N), Typ, Suppress => All_Checks);
8537 end Resolve_Unchecked_Expression;
8539 ---------------------------------------
8540 -- Resolve_Unchecked_Type_Conversion --
8541 ---------------------------------------
8543 procedure Resolve_Unchecked_Type_Conversion
8547 pragma Warnings (Off, Typ);
8549 Operand : constant Node_Id := Expression (N);
8550 Opnd_Type : constant Entity_Id := Etype (Operand);
8553 -- Resolve operand using its own type
8555 Resolve (Operand, Opnd_Type);
8556 Eval_Unchecked_Conversion (N);
8558 end Resolve_Unchecked_Type_Conversion;
8560 ------------------------------
8561 -- Rewrite_Operator_As_Call --
8562 ------------------------------
8564 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8565 Loc : constant Source_Ptr := Sloc (N);
8566 Actuals : constant List_Id := New_List;
8570 if Nkind (N) in N_Binary_Op then
8571 Append (Left_Opnd (N), Actuals);
8574 Append (Right_Opnd (N), Actuals);
8577 Make_Function_Call (Sloc => Loc,
8578 Name => New_Occurrence_Of (Nam, Loc),
8579 Parameter_Associations => Actuals);
8581 Preserve_Comes_From_Source (New_N, N);
8582 Preserve_Comes_From_Source (Name (New_N), N);
8584 Set_Etype (N, Etype (Nam));
8585 end Rewrite_Operator_As_Call;
8587 ------------------------------
8588 -- Rewrite_Renamed_Operator --
8589 ------------------------------
8591 procedure Rewrite_Renamed_Operator
8596 Nam : constant Name_Id := Chars (Op);
8597 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8601 -- Rewrite the operator node using the real operator, not its
8602 -- renaming. Exclude user-defined intrinsic operations of the same
8603 -- name, which are treated separately and rewritten as calls.
8605 if Ekind (Op) /= E_Function
8606 or else Chars (N) /= Nam
8608 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8609 Set_Chars (Op_Node, Nam);
8610 Set_Etype (Op_Node, Etype (N));
8611 Set_Entity (Op_Node, Op);
8612 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8614 -- Indicate that both the original entity and its renaming are
8615 -- referenced at this point.
8617 Generate_Reference (Entity (N), N);
8618 Generate_Reference (Op, N);
8621 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8624 Rewrite (N, Op_Node);
8626 -- If the context type is private, add the appropriate conversions
8627 -- so that the operator is applied to the full view. This is done
8628 -- in the routines that resolve intrinsic operators,
8630 if Is_Intrinsic_Subprogram (Op)
8631 and then Is_Private_Type (Typ)
8634 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8635 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8636 Resolve_Intrinsic_Operator (N, Typ);
8638 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8639 Resolve_Intrinsic_Unary_Operator (N, Typ);
8646 elsif Ekind (Op) = E_Function
8647 and then Is_Intrinsic_Subprogram (Op)
8649 -- Operator renames a user-defined operator of the same name. Use
8650 -- the original operator in the node, which is the one that Gigi
8654 Set_Is_Overloaded (N, False);
8656 end Rewrite_Renamed_Operator;
8658 -----------------------
8659 -- Set_Slice_Subtype --
8660 -----------------------
8662 -- Build an implicit subtype declaration to represent the type delivered
8663 -- by the slice. This is an abbreviated version of an array subtype. We
8664 -- define an index subtype for the slice, using either the subtype name
8665 -- or the discrete range of the slice. To be consistent with index usage
8666 -- elsewhere, we create a list header to hold the single index. This list
8667 -- is not otherwise attached to the syntax tree.
8669 procedure Set_Slice_Subtype (N : Node_Id) is
8670 Loc : constant Source_Ptr := Sloc (N);
8671 Index_List : constant List_Id := New_List;
8673 Index_Subtype : Entity_Id;
8674 Index_Type : Entity_Id;
8675 Slice_Subtype : Entity_Id;
8676 Drange : constant Node_Id := Discrete_Range (N);
8679 if Is_Entity_Name (Drange) then
8680 Index_Subtype := Entity (Drange);
8683 -- We force the evaluation of a range. This is definitely needed in
8684 -- the renamed case, and seems safer to do unconditionally. Note in
8685 -- any case that since we will create and insert an Itype referring
8686 -- to this range, we must make sure any side effect removal actions
8687 -- are inserted before the Itype definition.
8689 if Nkind (Drange) = N_Range then
8690 Force_Evaluation (Low_Bound (Drange));
8691 Force_Evaluation (High_Bound (Drange));
8694 Index_Type := Base_Type (Etype (Drange));
8696 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8698 Set_Scalar_Range (Index_Subtype, Drange);
8699 Set_Etype (Index_Subtype, Index_Type);
8700 Set_Size_Info (Index_Subtype, Index_Type);
8701 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8704 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8706 Index := New_Occurrence_Of (Index_Subtype, Loc);
8707 Set_Etype (Index, Index_Subtype);
8708 Append (Index, Index_List);
8710 Set_First_Index (Slice_Subtype, Index);
8711 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8712 Set_Is_Constrained (Slice_Subtype, True);
8714 Check_Compile_Time_Size (Slice_Subtype);
8716 -- The Etype of the existing Slice node is reset to this slice subtype.
8717 -- Its bounds are obtained from its first index.
8719 Set_Etype (N, Slice_Subtype);
8721 -- In the packed case, this must be immediately frozen
8723 -- Couldn't we always freeze here??? and if we did, then the above
8724 -- call to Check_Compile_Time_Size could be eliminated, which would
8725 -- be nice, because then that routine could be made private to Freeze.
8727 -- Why the test for In_Spec_Expression here ???
8729 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8730 Freeze_Itype (Slice_Subtype, N);
8733 end Set_Slice_Subtype;
8735 --------------------------------
8736 -- Set_String_Literal_Subtype --
8737 --------------------------------
8739 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8740 Loc : constant Source_Ptr := Sloc (N);
8741 Low_Bound : constant Node_Id :=
8742 Type_Low_Bound (Etype (First_Index (Typ)));
8743 Subtype_Id : Entity_Id;
8746 if Nkind (N) /= N_String_Literal then
8750 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8751 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8752 (String_Length (Strval (N))));
8753 Set_Etype (Subtype_Id, Base_Type (Typ));
8754 Set_Is_Constrained (Subtype_Id);
8755 Set_Etype (N, Subtype_Id);
8757 if Is_OK_Static_Expression (Low_Bound) then
8759 -- The low bound is set from the low bound of the corresponding
8760 -- index type. Note that we do not store the high bound in the
8761 -- string literal subtype, but it can be deduced if necessary
8762 -- from the length and the low bound.
8764 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8767 Set_String_Literal_Low_Bound
8768 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8769 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8771 -- Build bona fide subtype for the string, and wrap it in an
8772 -- unchecked conversion, because the backend expects the
8773 -- String_Literal_Subtype to have a static lower bound.
8776 Index_List : constant List_Id := New_List;
8777 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8778 High_Bound : constant Node_Id :=
8780 Left_Opnd => New_Copy_Tree (Low_Bound),
8782 Make_Integer_Literal (Loc,
8783 String_Length (Strval (N)) - 1));
8784 Array_Subtype : Entity_Id;
8785 Index_Subtype : Entity_Id;
8791 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8792 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8793 Set_Scalar_Range (Index_Subtype, Drange);
8794 Set_Parent (Drange, N);
8795 Analyze_And_Resolve (Drange, Index_Type);
8797 -- In the context, the Index_Type may already have a constraint,
8798 -- so use common base type on string subtype. The base type may
8799 -- be used when generating attributes of the string, for example
8800 -- in the context of a slice assignment.
8802 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8803 Set_Size_Info (Index_Subtype, Index_Type);
8804 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8806 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8808 Index := New_Occurrence_Of (Index_Subtype, Loc);
8809 Set_Etype (Index, Index_Subtype);
8810 Append (Index, Index_List);
8812 Set_First_Index (Array_Subtype, Index);
8813 Set_Etype (Array_Subtype, Base_Type (Typ));
8814 Set_Is_Constrained (Array_Subtype, True);
8817 Make_Unchecked_Type_Conversion (Loc,
8818 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8819 Expression => Relocate_Node (N)));
8820 Set_Etype (N, Array_Subtype);
8823 end Set_String_Literal_Subtype;
8825 ------------------------------
8826 -- Simplify_Type_Conversion --
8827 ------------------------------
8829 procedure Simplify_Type_Conversion (N : Node_Id) is
8831 if Nkind (N) = N_Type_Conversion then
8833 Operand : constant Node_Id := Expression (N);
8834 Target_Typ : constant Entity_Id := Etype (N);
8835 Opnd_Typ : constant Entity_Id := Etype (Operand);
8838 if Is_Floating_Point_Type (Opnd_Typ)
8840 (Is_Integer_Type (Target_Typ)
8841 or else (Is_Fixed_Point_Type (Target_Typ)
8842 and then Conversion_OK (N)))
8843 and then Nkind (Operand) = N_Attribute_Reference
8844 and then Attribute_Name (Operand) = Name_Truncation
8846 -- Special processing required if the conversion is the expression
8847 -- of a Truncation attribute reference. In this case we replace:
8849 -- ityp (ftyp'Truncation (x))
8855 -- with the Float_Truncate flag set, which is more efficient
8859 Relocate_Node (First (Expressions (Operand))));
8860 Set_Float_Truncate (N, True);
8864 end Simplify_Type_Conversion;
8866 -----------------------------
8867 -- Unique_Fixed_Point_Type --
8868 -----------------------------
8870 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8871 T1 : Entity_Id := Empty;
8876 procedure Fixed_Point_Error;
8877 -- If true ambiguity, give details
8879 -----------------------
8880 -- Fixed_Point_Error --
8881 -----------------------
8883 procedure Fixed_Point_Error is
8885 Error_Msg_N ("ambiguous universal_fixed_expression", N);
8886 Error_Msg_NE ("\\possible interpretation as}", N, T1);
8887 Error_Msg_NE ("\\possible interpretation as}", N, T2);
8888 end Fixed_Point_Error;
8890 -- Start of processing for Unique_Fixed_Point_Type
8893 -- The operations on Duration are visible, so Duration is always a
8894 -- possible interpretation.
8896 T1 := Standard_Duration;
8898 -- Look for fixed-point types in enclosing scopes
8900 Scop := Current_Scope;
8901 while Scop /= Standard_Standard loop
8902 T2 := First_Entity (Scop);
8903 while Present (T2) loop
8904 if Is_Fixed_Point_Type (T2)
8905 and then Current_Entity (T2) = T2
8906 and then Scope (Base_Type (T2)) = Scop
8908 if Present (T1) then
8919 Scop := Scope (Scop);
8922 -- Look for visible fixed type declarations in the context
8924 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
8925 while Present (Item) loop
8926 if Nkind (Item) = N_With_Clause then
8927 Scop := Entity (Name (Item));
8928 T2 := First_Entity (Scop);
8929 while Present (T2) loop
8930 if Is_Fixed_Point_Type (T2)
8931 and then Scope (Base_Type (T2)) = Scop
8932 and then (Is_Potentially_Use_Visible (T2)
8933 or else In_Use (T2))
8935 if Present (T1) then
8950 if Nkind (N) = N_Real_Literal then
8951 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
8953 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
8957 end Unique_Fixed_Point_Type;
8959 ----------------------
8960 -- Valid_Conversion --
8961 ----------------------
8963 function Valid_Conversion
8966 Operand : Node_Id) return Boolean
8968 Target_Type : constant Entity_Id := Base_Type (Target);
8969 Opnd_Type : Entity_Id := Etype (Operand);
8971 function Conversion_Check
8973 Msg : String) return Boolean;
8974 -- Little routine to post Msg if Valid is False, returns Valid value
8976 function Valid_Tagged_Conversion
8977 (Target_Type : Entity_Id;
8978 Opnd_Type : Entity_Id) return Boolean;
8979 -- Specifically test for validity of tagged conversions
8981 function Valid_Array_Conversion return Boolean;
8982 -- Check index and component conformance, and accessibility levels
8983 -- if the component types are anonymous access types (Ada 2005)
8985 ----------------------
8986 -- Conversion_Check --
8987 ----------------------
8989 function Conversion_Check
8991 Msg : String) return Boolean
8995 Error_Msg_N (Msg, Operand);
8999 end Conversion_Check;
9001 ----------------------------
9002 -- Valid_Array_Conversion --
9003 ----------------------------
9005 function Valid_Array_Conversion return Boolean
9007 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9008 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9010 Opnd_Index : Node_Id;
9011 Opnd_Index_Type : Entity_Id;
9013 Target_Comp_Type : constant Entity_Id :=
9014 Component_Type (Target_Type);
9015 Target_Comp_Base : constant Entity_Id :=
9016 Base_Type (Target_Comp_Type);
9018 Target_Index : Node_Id;
9019 Target_Index_Type : Entity_Id;
9022 -- Error if wrong number of dimensions
9025 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9028 ("incompatible number of dimensions for conversion", Operand);
9031 -- Number of dimensions matches
9034 -- Loop through indexes of the two arrays
9036 Target_Index := First_Index (Target_Type);
9037 Opnd_Index := First_Index (Opnd_Type);
9038 while Present (Target_Index) and then Present (Opnd_Index) loop
9039 Target_Index_Type := Etype (Target_Index);
9040 Opnd_Index_Type := Etype (Opnd_Index);
9042 -- Error if index types are incompatible
9044 if not (Is_Integer_Type (Target_Index_Type)
9045 and then Is_Integer_Type (Opnd_Index_Type))
9046 and then (Root_Type (Target_Index_Type)
9047 /= Root_Type (Opnd_Index_Type))
9050 ("incompatible index types for array conversion",
9055 Next_Index (Target_Index);
9056 Next_Index (Opnd_Index);
9059 -- If component types have same base type, all set
9061 if Target_Comp_Base = Opnd_Comp_Base then
9064 -- Here if base types of components are not the same. The only
9065 -- time this is allowed is if we have anonymous access types.
9067 -- The conversion of arrays of anonymous access types can lead
9068 -- to dangling pointers. AI-392 formalizes the accessibility
9069 -- checks that must be applied to such conversions to prevent
9070 -- out-of-scope references.
9073 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9075 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9076 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9078 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9080 if Type_Access_Level (Target_Type) <
9081 Type_Access_Level (Opnd_Type)
9083 if In_Instance_Body then
9084 Error_Msg_N ("?source array type " &
9085 "has deeper accessibility level than target", Operand);
9086 Error_Msg_N ("\?Program_Error will be raised at run time",
9089 Make_Raise_Program_Error (Sloc (N),
9090 Reason => PE_Accessibility_Check_Failed));
9091 Set_Etype (N, Target_Type);
9094 -- Conversion not allowed because of accessibility levels
9097 Error_Msg_N ("source array type " &
9098 "has deeper accessibility level than target", Operand);
9105 -- All other cases where component base types do not match
9109 ("incompatible component types for array conversion",
9114 -- Check that component subtypes statically match. For numeric
9115 -- types this means that both must be either constrained or
9116 -- unconstrained. For enumeration types the bounds must match.
9117 -- All of this is checked in Subtypes_Statically_Match.
9119 if not Subtypes_Statically_Match
9120 (Target_Comp_Type, Opnd_Comp_Type)
9123 ("component subtypes must statically match", Operand);
9129 end Valid_Array_Conversion;
9131 -----------------------------
9132 -- Valid_Tagged_Conversion --
9133 -----------------------------
9135 function Valid_Tagged_Conversion
9136 (Target_Type : Entity_Id;
9137 Opnd_Type : Entity_Id) return Boolean
9140 -- Upward conversions are allowed (RM 4.6(22))
9142 if Covers (Target_Type, Opnd_Type)
9143 or else Is_Ancestor (Target_Type, Opnd_Type)
9147 -- Downward conversion are allowed if the operand is class-wide
9150 elsif Is_Class_Wide_Type (Opnd_Type)
9151 and then Covers (Opnd_Type, Target_Type)
9155 elsif Covers (Opnd_Type, Target_Type)
9156 or else Is_Ancestor (Opnd_Type, Target_Type)
9159 Conversion_Check (False,
9160 "downward conversion of tagged objects not allowed");
9162 -- Ada 2005 (AI-251): The conversion to/from interface types is
9165 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9168 -- If the operand is a class-wide type obtained through a limited_
9169 -- with clause, and the context includes the non-limited view, use
9170 -- it to determine whether the conversion is legal.
9172 elsif Is_Class_Wide_Type (Opnd_Type)
9173 and then From_With_Type (Opnd_Type)
9174 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9175 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9179 elsif Is_Access_Type (Opnd_Type)
9180 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9186 ("invalid tagged conversion, not compatible with}",
9187 N, First_Subtype (Opnd_Type));
9190 end Valid_Tagged_Conversion;
9192 -- Start of processing for Valid_Conversion
9195 Check_Parameterless_Call (Operand);
9197 if Is_Overloaded (Operand) then
9206 -- Remove procedure calls, which syntactically cannot appear
9207 -- in this context, but which cannot be removed by type checking,
9208 -- because the context does not impose a type.
9210 -- When compiling for VMS, spurious ambiguities can be produced
9211 -- when arithmetic operations have a literal operand and return
9212 -- System.Address or a descendant of it. These ambiguities are
9213 -- otherwise resolved by the context, but for conversions there
9214 -- is no context type and the removal of the spurious operations
9215 -- must be done explicitly here.
9217 -- The node may be labelled overloaded, but still contain only
9218 -- one interpretation because others were discarded in previous
9219 -- filters. If this is the case, retain the single interpretation
9222 Get_First_Interp (Operand, I, It);
9223 Opnd_Type := It.Typ;
9224 Get_Next_Interp (I, It);
9227 and then Opnd_Type /= Standard_Void_Type
9229 -- More than one candidate interpretation is available
9231 Get_First_Interp (Operand, I, It);
9232 while Present (It.Typ) loop
9233 if It.Typ = Standard_Void_Type then
9237 if Present (System_Aux_Id)
9238 and then Is_Descendent_Of_Address (It.Typ)
9243 Get_Next_Interp (I, It);
9247 Get_First_Interp (Operand, I, It);
9252 Error_Msg_N ("illegal operand in conversion", Operand);
9256 Get_Next_Interp (I, It);
9258 if Present (It.Typ) then
9260 It1 := Disambiguate (Operand, I1, I, Any_Type);
9262 if It1 = No_Interp then
9263 Error_Msg_N ("ambiguous operand in conversion", Operand);
9265 Error_Msg_Sloc := Sloc (It.Nam);
9266 Error_Msg_N ("\\possible interpretation#!", Operand);
9268 Error_Msg_Sloc := Sloc (N1);
9269 Error_Msg_N ("\\possible interpretation#!", Operand);
9275 Set_Etype (Operand, It1.Typ);
9276 Opnd_Type := It1.Typ;
9282 if Is_Numeric_Type (Target_Type) then
9284 -- A universal fixed expression can be converted to any numeric type
9286 if Opnd_Type = Universal_Fixed then
9289 -- Also no need to check when in an instance or inlined body, because
9290 -- the legality has been established when the template was analyzed.
9291 -- Furthermore, numeric conversions may occur where only a private
9292 -- view of the operand type is visible at the instantiation point.
9293 -- This results in a spurious error if we check that the operand type
9294 -- is a numeric type.
9296 -- Note: in a previous version of this unit, the following tests were
9297 -- applied only for generated code (Comes_From_Source set to False),
9298 -- but in fact the test is required for source code as well, since
9299 -- this situation can arise in source code.
9301 elsif In_Instance or else In_Inlined_Body then
9304 -- Otherwise we need the conversion check
9307 return Conversion_Check
9308 (Is_Numeric_Type (Opnd_Type),
9309 "illegal operand for numeric conversion");
9314 elsif Is_Array_Type (Target_Type) then
9315 if not Is_Array_Type (Opnd_Type)
9316 or else Opnd_Type = Any_Composite
9317 or else Opnd_Type = Any_String
9320 ("illegal operand for array conversion", Operand);
9323 return Valid_Array_Conversion;
9326 -- Ada 2005 (AI-251): Anonymous access types where target references an
9329 elsif (Ekind (Target_Type) = E_General_Access_Type
9331 Ekind (Target_Type) = E_Anonymous_Access_Type)
9332 and then Is_Interface (Directly_Designated_Type (Target_Type))
9334 -- Check the static accessibility rule of 4.6(17). Note that the
9335 -- check is not enforced when within an instance body, since the RM
9336 -- requires such cases to be caught at run time.
9338 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9339 if Type_Access_Level (Opnd_Type) >
9340 Type_Access_Level (Target_Type)
9342 -- In an instance, this is a run-time check, but one we know
9343 -- will fail, so generate an appropriate warning. The raise
9344 -- will be generated by Expand_N_Type_Conversion.
9346 if In_Instance_Body then
9348 ("?cannot convert local pointer to non-local access type",
9351 ("\?Program_Error will be raised at run time", Operand);
9354 ("cannot convert local pointer to non-local access type",
9359 -- Special accessibility checks are needed in the case of access
9360 -- discriminants declared for a limited type.
9362 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9363 and then not Is_Local_Anonymous_Access (Opnd_Type)
9365 -- When the operand is a selected access discriminant the check
9366 -- needs to be made against the level of the object denoted by
9367 -- the prefix of the selected name. (Object_Access_Level
9368 -- handles checking the prefix of the operand for this case.)
9370 if Nkind (Operand) = N_Selected_Component
9371 and then Object_Access_Level (Operand) >
9372 Type_Access_Level (Target_Type)
9374 -- In an instance, this is a run-time check, but one we
9375 -- know will fail, so generate an appropriate warning.
9376 -- The raise will be generated by Expand_N_Type_Conversion.
9378 if In_Instance_Body then
9380 ("?cannot convert access discriminant to non-local" &
9381 " access type", Operand);
9383 ("\?Program_Error will be raised at run time", Operand);
9386 ("cannot convert access discriminant to non-local" &
9387 " access type", Operand);
9392 -- The case of a reference to an access discriminant from
9393 -- within a limited type declaration (which will appear as
9394 -- a discriminal) is always illegal because the level of the
9395 -- discriminant is considered to be deeper than any (nameable)
9398 if Is_Entity_Name (Operand)
9399 and then not Is_Local_Anonymous_Access (Opnd_Type)
9400 and then (Ekind (Entity (Operand)) = E_In_Parameter
9401 or else Ekind (Entity (Operand)) = E_Constant)
9402 and then Present (Discriminal_Link (Entity (Operand)))
9405 ("discriminant has deeper accessibility level than target",
9414 -- General and anonymous access types
9416 elsif (Ekind (Target_Type) = E_General_Access_Type
9417 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9420 (Is_Access_Type (Opnd_Type)
9421 and then Ekind (Opnd_Type) /=
9422 E_Access_Subprogram_Type
9423 and then Ekind (Opnd_Type) /=
9424 E_Access_Protected_Subprogram_Type,
9425 "must be an access-to-object type")
9427 if Is_Access_Constant (Opnd_Type)
9428 and then not Is_Access_Constant (Target_Type)
9431 ("access-to-constant operand type not allowed", Operand);
9435 -- Check the static accessibility rule of 4.6(17). Note that the
9436 -- check is not enforced when within an instance body, since the RM
9437 -- requires such cases to be caught at run time.
9439 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9440 or else Is_Local_Anonymous_Access (Target_Type)
9442 if Type_Access_Level (Opnd_Type)
9443 > Type_Access_Level (Target_Type)
9445 -- In an instance, this is a run-time check, but one we
9446 -- know will fail, so generate an appropriate warning.
9447 -- The raise will be generated by Expand_N_Type_Conversion.
9449 if In_Instance_Body then
9451 ("?cannot convert local pointer to non-local access type",
9454 ("\?Program_Error will be raised at run time", Operand);
9457 -- Avoid generation of spurious error message
9459 if not Error_Posted (N) then
9461 ("cannot convert local pointer to non-local access type",
9468 -- Special accessibility checks are needed in the case of access
9469 -- discriminants declared for a limited type.
9471 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9472 and then not Is_Local_Anonymous_Access (Opnd_Type)
9475 -- When the operand is a selected access discriminant the check
9476 -- needs to be made against the level of the object denoted by
9477 -- the prefix of the selected name. (Object_Access_Level
9478 -- handles checking the prefix of the operand for this case.)
9480 if Nkind (Operand) = N_Selected_Component
9481 and then Object_Access_Level (Operand) >
9482 Type_Access_Level (Target_Type)
9484 -- In an instance, this is a run-time check, but one we
9485 -- know will fail, so generate an appropriate warning.
9486 -- The raise will be generated by Expand_N_Type_Conversion.
9488 if In_Instance_Body then
9490 ("?cannot convert access discriminant to non-local" &
9491 " access type", Operand);
9493 ("\?Program_Error will be raised at run time",
9498 ("cannot convert access discriminant to non-local" &
9499 " access type", Operand);
9504 -- The case of a reference to an access discriminant from
9505 -- within a limited type declaration (which will appear as
9506 -- a discriminal) is always illegal because the level of the
9507 -- discriminant is considered to be deeper than any (nameable)
9510 if Is_Entity_Name (Operand)
9511 and then (Ekind (Entity (Operand)) = E_In_Parameter
9512 or else Ekind (Entity (Operand)) = E_Constant)
9513 and then Present (Discriminal_Link (Entity (Operand)))
9516 ("discriminant has deeper accessibility level than target",
9524 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9525 -- Helper function to handle limited views
9527 --------------------------
9528 -- Full_Designated_Type --
9529 --------------------------
9531 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9532 Desig : constant Entity_Id := Designated_Type (T);
9534 if From_With_Type (Desig)
9535 and then Is_Incomplete_Type (Desig)
9536 and then Present (Non_Limited_View (Desig))
9538 return Non_Limited_View (Desig);
9542 end Full_Designated_Type;
9544 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9545 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9547 Same_Base : constant Boolean :=
9548 Base_Type (Target) = Base_Type (Opnd);
9551 if Is_Tagged_Type (Target) then
9552 return Valid_Tagged_Conversion (Target, Opnd);
9555 if not Same_Base then
9557 ("target designated type not compatible with }",
9558 N, Base_Type (Opnd));
9561 -- Ada 2005 AI-384: legality rule is symmetric in both
9562 -- designated types. The conversion is legal (with possible
9563 -- constraint check) if either designated type is
9566 elsif Subtypes_Statically_Match (Target, Opnd)
9568 (Has_Discriminants (Target)
9570 (not Is_Constrained (Opnd)
9571 or else not Is_Constrained (Target)))
9573 -- Special case, if Value_Size has been used to make the
9574 -- sizes different, the conversion is not allowed even
9575 -- though the subtypes statically match.
9577 if Known_Static_RM_Size (Target)
9578 and then Known_Static_RM_Size (Opnd)
9579 and then RM_Size (Target) /= RM_Size (Opnd)
9582 ("target designated subtype not compatible with }",
9585 ("\because sizes of the two designated subtypes differ",
9589 -- Normal case where conversion is allowed
9597 ("target designated subtype not compatible with }",
9604 -- Access to subprogram types. If the operand is an access parameter,
9605 -- the type has a deeper accessibility that any master, and cannot
9606 -- be assigned. We must make an exception if the conversion is part
9607 -- of an assignment and the target is the return object of an extended
9608 -- return statement, because in that case the accessibility check
9609 -- takes place after the return.
9611 elsif Is_Access_Subprogram_Type (Target_Type)
9612 and then No (Corresponding_Remote_Type (Opnd_Type))
9614 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9615 and then Is_Entity_Name (Operand)
9616 and then Ekind (Entity (Operand)) = E_In_Parameter
9618 (Nkind (Parent (N)) /= N_Assignment_Statement
9619 or else not Is_Entity_Name (Name (Parent (N)))
9620 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9623 ("illegal attempt to store anonymous access to subprogram",
9626 ("\value has deeper accessibility than any master " &
9631 ("\use named access type for& instead of access parameter",
9632 Operand, Entity (Operand));
9635 -- Check that the designated types are subtype conformant
9637 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9638 Old_Id => Designated_Type (Opnd_Type),
9641 -- Check the static accessibility rule of 4.6(20)
9643 if Type_Access_Level (Opnd_Type) >
9644 Type_Access_Level (Target_Type)
9647 ("operand type has deeper accessibility level than target",
9650 -- Check that if the operand type is declared in a generic body,
9651 -- then the target type must be declared within that same body
9652 -- (enforces last sentence of 4.6(20)).
9654 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9656 O_Gen : constant Node_Id :=
9657 Enclosing_Generic_Body (Opnd_Type);
9662 T_Gen := Enclosing_Generic_Body (Target_Type);
9663 while Present (T_Gen) and then T_Gen /= O_Gen loop
9664 T_Gen := Enclosing_Generic_Body (T_Gen);
9667 if T_Gen /= O_Gen then
9669 ("target type must be declared in same generic body"
9670 & " as operand type", N);
9677 -- Remote subprogram access types
9679 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9680 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9682 -- It is valid to convert from one RAS type to another provided
9683 -- that their specification statically match.
9685 Check_Subtype_Conformant
9687 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9689 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9694 -- If both are tagged types, check legality of view conversions
9696 elsif Is_Tagged_Type (Target_Type)
9697 and then Is_Tagged_Type (Opnd_Type)
9699 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9701 -- Types derived from the same root type are convertible
9703 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9706 -- In an instance or an inlined body, there may be inconsistent
9707 -- views of the same type, or of types derived from a common root.
9709 elsif (In_Instance or In_Inlined_Body)
9711 Root_Type (Underlying_Type (Target_Type)) =
9712 Root_Type (Underlying_Type (Opnd_Type))
9716 -- Special check for common access type error case
9718 elsif Ekind (Target_Type) = E_Access_Type
9719 and then Is_Access_Type (Opnd_Type)
9721 Error_Msg_N ("target type must be general access type!", N);
9722 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9727 Error_Msg_NE ("invalid conversion, not compatible with }",
9732 end Valid_Conversion;
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