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 function Static_Concatenation (N : Node_Id) return Boolean;
2672 -- Predicate to determine whether an actual that is a concatenation
2673 -- will be evaluated statically and does not need a transient scope.
2674 -- This must be determined before the actual is resolved and expanded
2675 -- because if needed the transient scope must be introduced earlier.
2677 --------------------------
2678 -- Check_Argument_Order --
2679 --------------------------
2681 procedure Check_Argument_Order is
2683 -- Nothing to do if no parameters, or original node is neither a
2684 -- function call nor a procedure call statement (happens in the
2685 -- operator-transformed-to-function call case), or the call does
2686 -- not come from source, or this warning is off.
2688 if not Warn_On_Parameter_Order
2690 No (Parameter_Associations (N))
2692 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2695 not Comes_From_Source (N)
2701 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2704 -- Nothing to do if only one parameter
2710 -- Here if at least two arguments
2713 Actuals : array (1 .. Nargs) of Node_Id;
2717 Wrong_Order : Boolean := False;
2718 -- Set True if an out of order case is found
2721 -- Collect identifier names of actuals, fail if any actual is
2722 -- not a simple identifier, and record max length of name.
2724 Actual := First (Parameter_Associations (N));
2725 for J in Actuals'Range loop
2726 if Nkind (Actual) /= N_Identifier then
2729 Actuals (J) := Actual;
2734 -- If we got this far, all actuals are identifiers and the list
2735 -- of their names is stored in the Actuals array.
2737 Formal := First_Formal (Nam);
2738 for J in Actuals'Range loop
2740 -- If we ran out of formals, that's odd, probably an error
2741 -- which will be detected elsewhere, but abandon the search.
2747 -- If name matches and is in order OK
2749 if Chars (Formal) = Chars (Actuals (J)) then
2753 -- If no match, see if it is elsewhere in list and if so
2754 -- flag potential wrong order if type is compatible.
2756 for K in Actuals'Range loop
2757 if Chars (Formal) = Chars (Actuals (K))
2759 Has_Compatible_Type (Actuals (K), Etype (Formal))
2761 Wrong_Order := True;
2771 <<Continue>> Next_Formal (Formal);
2774 -- If Formals left over, also probably an error, skip warning
2776 if Present (Formal) then
2780 -- Here we give the warning if something was out of order
2784 ("actuals for this call may be in wrong order?", N);
2788 end Check_Argument_Order;
2790 -------------------------
2791 -- Check_Prefixed_Call --
2792 -------------------------
2794 procedure Check_Prefixed_Call is
2795 Act : constant Node_Id := First_Actual (N);
2796 A_Type : constant Entity_Id := Etype (Act);
2797 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2798 Orig : constant Node_Id := Original_Node (N);
2802 -- Check whether the call is a prefixed call, with or without
2803 -- additional actuals.
2805 if Nkind (Orig) = N_Selected_Component
2807 (Nkind (Orig) = N_Indexed_Component
2808 and then Nkind (Prefix (Orig)) = N_Selected_Component
2809 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2810 and then Is_Entity_Name (Act)
2811 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2813 if Is_Access_Type (A_Type)
2814 and then not Is_Access_Type (F_Type)
2816 -- Introduce dereference on object in prefix
2819 Make_Explicit_Dereference (Sloc (Act),
2820 Prefix => Relocate_Node (Act));
2821 Rewrite (Act, New_A);
2824 elsif Is_Access_Type (F_Type)
2825 and then not Is_Access_Type (A_Type)
2827 -- Introduce an implicit 'Access in prefix
2829 if not Is_Aliased_View (Act) then
2831 ("object in prefixed call to& must be aliased"
2832 & " (RM-2005 4.3.1 (13))",
2837 Make_Attribute_Reference (Loc,
2838 Attribute_Name => Name_Access,
2839 Prefix => Relocate_Node (Act)));
2844 end Check_Prefixed_Call;
2846 --------------------
2847 -- Insert_Default --
2848 --------------------
2850 procedure Insert_Default is
2855 -- Missing argument in call, nothing to insert
2857 if No (Default_Value (F)) then
2861 -- Note that we do a full New_Copy_Tree, so that any associated
2862 -- Itypes are properly copied. This may not be needed any more,
2863 -- but it does no harm as a safety measure! Defaults of a generic
2864 -- formal may be out of bounds of the corresponding actual (see
2865 -- cc1311b) and an additional check may be required.
2870 New_Scope => Current_Scope,
2873 if Is_Concurrent_Type (Scope (Nam))
2874 and then Has_Discriminants (Scope (Nam))
2876 Replace_Actual_Discriminants (N, Actval);
2879 if Is_Overloadable (Nam)
2880 and then Present (Alias (Nam))
2882 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2883 and then not Is_Tagged_Type (Etype (F))
2885 -- If default is a real literal, do not introduce a
2886 -- conversion whose effect may depend on the run-time
2887 -- size of universal real.
2889 if Nkind (Actval) = N_Real_Literal then
2890 Set_Etype (Actval, Base_Type (Etype (F)));
2892 Actval := Unchecked_Convert_To (Etype (F), Actval);
2896 if Is_Scalar_Type (Etype (F)) then
2897 Enable_Range_Check (Actval);
2900 Set_Parent (Actval, N);
2902 -- Resolve aggregates with their base type, to avoid scope
2903 -- anomalies: the subtype was first built in the subprogram
2904 -- declaration, and the current call may be nested.
2906 if Nkind (Actval) = N_Aggregate
2907 and then Has_Discriminants (Etype (Actval))
2909 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2911 Analyze_And_Resolve (Actval, Etype (Actval));
2915 Set_Parent (Actval, N);
2917 -- See note above concerning aggregates
2919 if Nkind (Actval) = N_Aggregate
2920 and then Has_Discriminants (Etype (Actval))
2922 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2924 -- Resolve entities with their own type, which may differ
2925 -- from the type of a reference in a generic context (the
2926 -- view swapping mechanism did not anticipate the re-analysis
2927 -- of default values in calls).
2929 elsif Is_Entity_Name (Actval) then
2930 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2933 Analyze_And_Resolve (Actval, Etype (Actval));
2937 -- If default is a tag indeterminate function call, propagate
2938 -- tag to obtain proper dispatching.
2940 if Is_Controlling_Formal (F)
2941 and then Nkind (Default_Value (F)) = N_Function_Call
2943 Set_Is_Controlling_Actual (Actval);
2948 -- If the default expression raises constraint error, then just
2949 -- silently replace it with an N_Raise_Constraint_Error node,
2950 -- since we already gave the warning on the subprogram spec.
2952 if Raises_Constraint_Error (Actval) then
2954 Make_Raise_Constraint_Error (Loc,
2955 Reason => CE_Range_Check_Failed));
2956 Set_Raises_Constraint_Error (Actval);
2957 Set_Etype (Actval, Etype (F));
2961 Make_Parameter_Association (Loc,
2962 Explicit_Actual_Parameter => Actval,
2963 Selector_Name => Make_Identifier (Loc, Chars (F)));
2965 -- Case of insertion is first named actual
2967 if No (Prev) or else
2968 Nkind (Parent (Prev)) /= N_Parameter_Association
2970 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2971 Set_First_Named_Actual (N, Actval);
2974 if No (Parameter_Associations (N)) then
2975 Set_Parameter_Associations (N, New_List (Assoc));
2977 Append (Assoc, Parameter_Associations (N));
2981 Insert_After (Prev, Assoc);
2984 -- Case of insertion is not first named actual
2987 Set_Next_Named_Actual
2988 (Assoc, Next_Named_Actual (Parent (Prev)));
2989 Set_Next_Named_Actual (Parent (Prev), Actval);
2990 Append (Assoc, Parameter_Associations (N));
2993 Mark_Rewrite_Insertion (Assoc);
2994 Mark_Rewrite_Insertion (Actval);
3003 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3004 FT1 : Entity_Id := T1;
3005 FT2 : Entity_Id := T2;
3008 if Is_Private_Type (T1)
3009 and then Present (Full_View (T1))
3011 FT1 := Full_View (T1);
3014 if Is_Private_Type (T2)
3015 and then Present (Full_View (T2))
3017 FT2 := Full_View (T2);
3020 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3023 --------------------------
3024 -- Static_Concatenation --
3025 --------------------------
3027 function Static_Concatenation (N : Node_Id) return Boolean is
3030 when N_String_Literal =>
3035 -- Concatenation is static when both operands are static
3036 -- and the concatenation operator is a predefined one.
3038 return Scope (Entity (N)) = Standard_Standard
3040 Static_Concatenation (Left_Opnd (N))
3042 Static_Concatenation (Right_Opnd (N));
3045 if Is_Entity_Name (N) then
3047 Ent : constant Entity_Id := Entity (N);
3049 return Ekind (Ent) = E_Constant
3050 and then Present (Constant_Value (Ent))
3052 Is_Static_Expression (Constant_Value (Ent));
3059 end Static_Concatenation;
3061 -- Start of processing for Resolve_Actuals
3064 Check_Argument_Order;
3066 if Present (First_Actual (N)) then
3067 Check_Prefixed_Call;
3070 A := First_Actual (N);
3071 F := First_Formal (Nam);
3072 while Present (F) loop
3073 if No (A) and then Needs_No_Actuals (Nam) then
3076 -- If we have an error in any actual or formal, indicated by a type
3077 -- of Any_Type, then abandon resolution attempt, and set result type
3080 elsif (Present (A) and then Etype (A) = Any_Type)
3081 or else Etype (F) = Any_Type
3083 Set_Etype (N, Any_Type);
3087 -- Case where actual is present
3089 -- If the actual is an entity, generate a reference to it now. We
3090 -- do this before the actual is resolved, because a formal of some
3091 -- protected subprogram, or a task discriminant, will be rewritten
3092 -- during expansion, and the reference to the source entity may
3096 and then Is_Entity_Name (A)
3097 and then Comes_From_Source (N)
3099 Orig_A := Entity (A);
3101 if Present (Orig_A) then
3102 if Is_Formal (Orig_A)
3103 and then Ekind (F) /= E_In_Parameter
3105 Generate_Reference (Orig_A, A, 'm');
3106 elsif not Is_Overloaded (A) then
3107 Generate_Reference (Orig_A, A);
3113 and then (Nkind (Parent (A)) /= N_Parameter_Association
3115 Chars (Selector_Name (Parent (A))) = Chars (F))
3117 -- If style checking mode on, check match of formal name
3120 if Nkind (Parent (A)) = N_Parameter_Association then
3121 Check_Identifier (Selector_Name (Parent (A)), F);
3125 -- If the formal is Out or In_Out, do not resolve and expand the
3126 -- conversion, because it is subsequently expanded into explicit
3127 -- temporaries and assignments. However, the object of the
3128 -- conversion can be resolved. An exception is the case of tagged
3129 -- type conversion with a class-wide actual. In that case we want
3130 -- the tag check to occur and no temporary will be needed (no
3131 -- representation change can occur) and the parameter is passed by
3132 -- reference, so we go ahead and resolve the type conversion.
3133 -- Another exception is the case of reference to component or
3134 -- subcomponent of a bit-packed array, in which case we want to
3135 -- defer expansion to the point the in and out assignments are
3138 if Ekind (F) /= E_In_Parameter
3139 and then Nkind (A) = N_Type_Conversion
3140 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3142 if Ekind (F) = E_In_Out_Parameter
3143 and then Is_Array_Type (Etype (F))
3145 if Has_Aliased_Components (Etype (Expression (A)))
3146 /= Has_Aliased_Components (Etype (F))
3149 -- In a view conversion, the conversion must be legal in
3150 -- both directions, and thus both component types must be
3151 -- aliased, or neither (4.6 (8)).
3153 -- The additional rule 4.6 (24.9.2) seems unduly
3154 -- restrictive: the privacy requirement should not apply
3155 -- to generic types, and should be checked in an
3156 -- instance. ARG query is in order ???
3159 ("both component types in a view conversion must be"
3160 & " aliased, or neither", A);
3163 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3165 if Is_By_Reference_Type (Etype (F))
3166 or else Is_By_Reference_Type (Etype (Expression (A)))
3169 ("view conversion between unrelated by reference " &
3170 "array types not allowed (\'A'I-00246)", A);
3173 Comp_Type : constant Entity_Id :=
3175 (Etype (Expression (A)));
3177 if Comes_From_Source (A)
3178 and then Ada_Version >= Ada_05
3180 ((Is_Private_Type (Comp_Type)
3181 and then not Is_Generic_Type (Comp_Type))
3182 or else Is_Tagged_Type (Comp_Type)
3183 or else Is_Volatile (Comp_Type))
3186 ("component type of a view conversion cannot"
3187 & " be private, tagged, or volatile"
3196 if (Conversion_OK (A)
3197 or else Valid_Conversion (A, Etype (A), Expression (A)))
3198 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3200 Resolve (Expression (A));
3203 -- If the actual is a function call that returns a limited
3204 -- unconstrained object that needs finalization, create a
3205 -- transient scope for it, so that it can receive the proper
3206 -- finalization list.
3208 elsif Nkind (A) = N_Function_Call
3209 and then Is_Limited_Record (Etype (F))
3210 and then not Is_Constrained (Etype (F))
3211 and then Expander_Active
3213 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3215 Establish_Transient_Scope (A, False);
3217 -- A small optimization: if one of the actuals is a concatenation
3218 -- create a block around a procedure call to recover stack space.
3219 -- This alleviates stack usage when several procedure calls in
3220 -- the same statement list use concatenation. We do not perform
3221 -- this wrapping for code statements, where the argument is a
3222 -- static string, and we want to preserve warnings involving
3223 -- sequences of such statements.
3225 elsif Nkind (A) = N_Op_Concat
3226 and then Nkind (N) = N_Procedure_Call_Statement
3227 and then Expander_Active
3229 not (Is_Intrinsic_Subprogram (Nam)
3230 and then Chars (Nam) = Name_Asm)
3231 and then not Static_Concatenation (A)
3233 Establish_Transient_Scope (A, False);
3234 Resolve (A, Etype (F));
3237 if Nkind (A) = N_Type_Conversion
3238 and then Is_Array_Type (Etype (F))
3239 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3241 (Is_Limited_Type (Etype (F))
3242 or else Is_Limited_Type (Etype (Expression (A))))
3245 ("conversion between unrelated limited array types " &
3246 "not allowed (\A\I-00246)", A);
3248 if Is_Limited_Type (Etype (F)) then
3249 Explain_Limited_Type (Etype (F), A);
3252 if Is_Limited_Type (Etype (Expression (A))) then
3253 Explain_Limited_Type (Etype (Expression (A)), A);
3257 -- (Ada 2005: AI-251): If the actual is an allocator whose
3258 -- directly designated type is a class-wide interface, we build
3259 -- an anonymous access type to use it as the type of the
3260 -- allocator. Later, when the subprogram call is expanded, if
3261 -- the interface has a secondary dispatch table the expander
3262 -- will add a type conversion to force the correct displacement
3265 if Nkind (A) = N_Allocator then
3267 DDT : constant Entity_Id :=
3268 Directly_Designated_Type (Base_Type (Etype (F)));
3270 New_Itype : Entity_Id;
3273 if Is_Class_Wide_Type (DDT)
3274 and then Is_Interface (DDT)
3276 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3277 Set_Etype (New_Itype, Etype (A));
3278 Set_Directly_Designated_Type (New_Itype,
3279 Directly_Designated_Type (Etype (A)));
3280 Set_Etype (A, New_Itype);
3283 -- Ada 2005, AI-162:If the actual is an allocator, the
3284 -- innermost enclosing statement is the master of the
3285 -- created object. This needs to be done with expansion
3286 -- enabled only, otherwise the transient scope will not
3287 -- be removed in the expansion of the wrapped construct.
3289 if (Is_Controlled (DDT) or else Has_Task (DDT))
3290 and then Expander_Active
3292 Establish_Transient_Scope (A, False);
3297 -- (Ada 2005): The call may be to a primitive operation of
3298 -- a tagged synchronized type, declared outside of the type.
3299 -- In this case the controlling actual must be converted to
3300 -- its corresponding record type, which is the formal type.
3301 -- The actual may be a subtype, either because of a constraint
3302 -- or because it is a generic actual, so use base type to
3303 -- locate concurrent type.
3305 A_Typ := Base_Type (Etype (A));
3306 F_Typ := Base_Type (Etype (F));
3309 Full_A_Typ : Entity_Id;
3312 if Present (Full_View (A_Typ)) then
3313 Full_A_Typ := Base_Type (Full_View (A_Typ));
3315 Full_A_Typ := A_Typ;
3318 -- Tagged synchronized type (case 1): the actual is a
3321 if Is_Concurrent_Type (A_Typ)
3322 and then Corresponding_Record_Type (A_Typ) = F_Typ
3325 Unchecked_Convert_To
3326 (Corresponding_Record_Type (A_Typ), A));
3327 Resolve (A, Etype (F));
3329 -- Tagged synchronized type (case 2): the formal is a
3332 elsif Ekind (Full_A_Typ) = E_Record_Type
3334 (Corresponding_Concurrent_Type (Full_A_Typ))
3335 and then Is_Concurrent_Type (F_Typ)
3336 and then Present (Corresponding_Record_Type (F_Typ))
3337 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3339 Resolve (A, Corresponding_Record_Type (F_Typ));
3344 Resolve (A, Etype (F));
3352 -- For mode IN, if actual is an entity, and the type of the formal
3353 -- has warnings suppressed, then we reset Never_Set_In_Source for
3354 -- the calling entity. The reason for this is to catch cases like
3355 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3356 -- uses trickery to modify an IN parameter.
3358 if Ekind (F) = E_In_Parameter
3359 and then Is_Entity_Name (A)
3360 and then Present (Entity (A))
3361 and then Ekind (Entity (A)) = E_Variable
3362 and then Has_Warnings_Off (F_Typ)
3364 Set_Never_Set_In_Source (Entity (A), False);
3367 -- Perform error checks for IN and IN OUT parameters
3369 if Ekind (F) /= E_Out_Parameter then
3371 -- Check unset reference. For scalar parameters, it is clearly
3372 -- wrong to pass an uninitialized value as either an IN or
3373 -- IN-OUT parameter. For composites, it is also clearly an
3374 -- error to pass a completely uninitialized value as an IN
3375 -- parameter, but the case of IN OUT is trickier. We prefer
3376 -- not to give a warning here. For example, suppose there is
3377 -- a routine that sets some component of a record to False.
3378 -- It is perfectly reasonable to make this IN-OUT and allow
3379 -- either initialized or uninitialized records to be passed
3382 -- For partially initialized composite values, we also avoid
3383 -- warnings, since it is quite likely that we are passing a
3384 -- partially initialized value and only the initialized fields
3385 -- will in fact be read in the subprogram.
3387 if Is_Scalar_Type (A_Typ)
3388 or else (Ekind (F) = E_In_Parameter
3389 and then not Is_Partially_Initialized_Type (A_Typ))
3391 Check_Unset_Reference (A);
3394 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3395 -- actual to a nested call, since this is case of reading an
3396 -- out parameter, which is not allowed.
3398 if Ada_Version = Ada_83
3399 and then Is_Entity_Name (A)
3400 and then Ekind (Entity (A)) = E_Out_Parameter
3402 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3406 -- Case of OUT or IN OUT parameter
3408 if Ekind (F) /= E_In_Parameter then
3410 -- For an Out parameter, check for useless assignment. Note
3411 -- that we can't set Last_Assignment this early, because we may
3412 -- kill current values in Resolve_Call, and that call would
3413 -- clobber the Last_Assignment field.
3415 -- Note: call Warn_On_Useless_Assignment before doing the check
3416 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3417 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3418 -- reflects the last assignment, not this one!
3420 if Ekind (F) = E_Out_Parameter then
3421 if Warn_On_Modified_As_Out_Parameter (F)
3422 and then Is_Entity_Name (A)
3423 and then Present (Entity (A))
3424 and then Comes_From_Source (N)
3426 Warn_On_Useless_Assignment (Entity (A), A);
3430 -- Validate the form of the actual. Note that the call to
3431 -- Is_OK_Variable_For_Out_Formal generates the required
3432 -- reference in this case.
3434 if not Is_OK_Variable_For_Out_Formal (A) then
3435 Error_Msg_NE ("actual for& must be a variable", A, F);
3438 -- What's the following about???
3440 if Is_Entity_Name (A) then
3441 Kill_Checks (Entity (A));
3447 if Etype (A) = Any_Type then
3448 Set_Etype (N, Any_Type);
3452 -- Apply appropriate range checks for in, out, and in-out
3453 -- parameters. Out and in-out parameters also need a separate
3454 -- check, if there is a type conversion, to make sure the return
3455 -- value meets the constraints of the variable before the
3458 -- Gigi looks at the check flag and uses the appropriate types.
3459 -- For now since one flag is used there is an optimization which
3460 -- might not be done in the In Out case since Gigi does not do
3461 -- any analysis. More thought required about this ???
3463 if Ekind (F) = E_In_Parameter
3464 or else Ekind (F) = E_In_Out_Parameter
3466 if Is_Scalar_Type (Etype (A)) then
3467 Apply_Scalar_Range_Check (A, F_Typ);
3469 elsif Is_Array_Type (Etype (A)) then
3470 Apply_Length_Check (A, F_Typ);
3472 elsif Is_Record_Type (F_Typ)
3473 and then Has_Discriminants (F_Typ)
3474 and then Is_Constrained (F_Typ)
3475 and then (not Is_Derived_Type (F_Typ)
3476 or else Comes_From_Source (Nam))
3478 Apply_Discriminant_Check (A, F_Typ);
3480 elsif Is_Access_Type (F_Typ)
3481 and then Is_Array_Type (Designated_Type (F_Typ))
3482 and then Is_Constrained (Designated_Type (F_Typ))
3484 Apply_Length_Check (A, F_Typ);
3486 elsif Is_Access_Type (F_Typ)
3487 and then Has_Discriminants (Designated_Type (F_Typ))
3488 and then Is_Constrained (Designated_Type (F_Typ))
3490 Apply_Discriminant_Check (A, F_Typ);
3493 Apply_Range_Check (A, F_Typ);
3496 -- Ada 2005 (AI-231)
3498 if Ada_Version >= Ada_05
3499 and then Is_Access_Type (F_Typ)
3500 and then Can_Never_Be_Null (F_Typ)
3501 and then Known_Null (A)
3503 Apply_Compile_Time_Constraint_Error
3505 Msg => "(Ada 2005) null not allowed in "
3506 & "null-excluding formal?",
3507 Reason => CE_Null_Not_Allowed);
3511 if Ekind (F) = E_Out_Parameter
3512 or else Ekind (F) = E_In_Out_Parameter
3514 if Nkind (A) = N_Type_Conversion then
3515 if Is_Scalar_Type (A_Typ) then
3516 Apply_Scalar_Range_Check
3517 (Expression (A), Etype (Expression (A)), A_Typ);
3520 (Expression (A), Etype (Expression (A)), A_Typ);
3524 if Is_Scalar_Type (F_Typ) then
3525 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3527 elsif Is_Array_Type (F_Typ)
3528 and then Ekind (F) = E_Out_Parameter
3530 Apply_Length_Check (A, F_Typ);
3533 Apply_Range_Check (A, A_Typ, F_Typ);
3538 -- An actual associated with an access parameter is implicitly
3539 -- converted to the anonymous access type of the formal and must
3540 -- satisfy the legality checks for access conversions.
3542 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3543 if not Valid_Conversion (A, F_Typ, A) then
3545 ("invalid implicit conversion for access parameter", A);
3549 -- Check bad case of atomic/volatile argument (RM C.6(12))
3551 if Is_By_Reference_Type (Etype (F))
3552 and then Comes_From_Source (N)
3554 if Is_Atomic_Object (A)
3555 and then not Is_Atomic (Etype (F))
3558 ("cannot pass atomic argument to non-atomic formal",
3561 elsif Is_Volatile_Object (A)
3562 and then not Is_Volatile (Etype (F))
3565 ("cannot pass volatile argument to non-volatile formal",
3570 -- Check that subprograms don't have improper controlling
3571 -- arguments (RM 3.9.2 (9)).
3573 -- A primitive operation may have an access parameter of an
3574 -- incomplete tagged type, but a dispatching call is illegal
3575 -- if the type is still incomplete.
3577 if Is_Controlling_Formal (F) then
3578 Set_Is_Controlling_Actual (A);
3580 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3582 Desig : constant Entity_Id := Designated_Type (Etype (F));
3584 if Ekind (Desig) = E_Incomplete_Type
3585 and then No (Full_View (Desig))
3586 and then No (Non_Limited_View (Desig))
3589 ("premature use of incomplete type& " &
3590 "in dispatching call", A, Desig);
3595 elsif Nkind (A) = N_Explicit_Dereference then
3596 Validate_Remote_Access_To_Class_Wide_Type (A);
3599 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3600 and then not Is_Class_Wide_Type (F_Typ)
3601 and then not Is_Controlling_Formal (F)
3603 Error_Msg_N ("class-wide argument not allowed here!", A);
3605 if Is_Subprogram (Nam)
3606 and then Comes_From_Source (Nam)
3608 Error_Msg_Node_2 := F_Typ;
3610 ("& is not a dispatching operation of &!", A, Nam);
3613 elsif Is_Access_Type (A_Typ)
3614 and then Is_Access_Type (F_Typ)
3615 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3616 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3617 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3618 or else (Nkind (A) = N_Attribute_Reference
3620 Is_Class_Wide_Type (Etype (Prefix (A)))))
3621 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3622 and then not Is_Controlling_Formal (F)
3625 ("access to class-wide argument not allowed here!", A);
3627 if Is_Subprogram (Nam)
3628 and then Comes_From_Source (Nam)
3630 Error_Msg_Node_2 := Designated_Type (F_Typ);
3632 ("& is not a dispatching operation of &!", A, Nam);
3638 -- If it is a named association, treat the selector_name as
3639 -- a proper identifier, and mark the corresponding entity.
3641 if Nkind (Parent (A)) = N_Parameter_Association then
3642 Set_Entity (Selector_Name (Parent (A)), F);
3643 Generate_Reference (F, Selector_Name (Parent (A)));
3644 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3645 Generate_Reference (F_Typ, N, ' ');
3650 if Ekind (F) /= E_Out_Parameter then
3651 Check_Unset_Reference (A);
3656 -- Case where actual is not present
3664 end Resolve_Actuals;
3666 -----------------------
3667 -- Resolve_Allocator --
3668 -----------------------
3670 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3671 E : constant Node_Id := Expression (N);
3673 Discrim : Entity_Id;
3676 Assoc : Node_Id := Empty;
3679 procedure Check_Allocator_Discrim_Accessibility
3680 (Disc_Exp : Node_Id;
3681 Alloc_Typ : Entity_Id);
3682 -- Check that accessibility level associated with an access discriminant
3683 -- initialized in an allocator by the expression Disc_Exp is not deeper
3684 -- than the level of the allocator type Alloc_Typ. An error message is
3685 -- issued if this condition is violated. Specialized checks are done for
3686 -- the cases of a constraint expression which is an access attribute or
3687 -- an access discriminant.
3689 function In_Dispatching_Context return Boolean;
3690 -- If the allocator is an actual in a call, it is allowed to be class-
3691 -- wide when the context is not because it is a controlling actual.
3693 procedure Propagate_Coextensions (Root : Node_Id);
3694 -- Propagate all nested coextensions which are located one nesting
3695 -- level down the tree to the node Root. Example:
3698 -- Level_1_Coextension
3699 -- Level_2_Coextension
3701 -- The algorithm is paired with delay actions done by the Expander. In
3702 -- the above example, assume all coextensions are controlled types.
3703 -- The cycle of analysis, resolution and expansion will yield:
3705 -- 1) Analyze Top_Record
3706 -- 2) Analyze Level_1_Coextension
3707 -- 3) Analyze Level_2_Coextension
3708 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3710 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3711 -- generated to capture the allocated object. Temp_1 is attached
3712 -- to the coextension chain of Level_2_Coextension.
3713 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3714 -- coextension. A forward tree traversal is performed which finds
3715 -- Level_2_Coextension's list and copies its contents into its
3717 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3718 -- generated to capture the allocated object. Temp_2 is attached
3719 -- to the coextension chain of Level_1_Coextension. Currently, the
3720 -- contents of the list are [Temp_2, Temp_1].
3721 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3722 -- finds Level_1_Coextension's list and copies its contents into
3724 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3725 -- Temp_2 and attach them to Top_Record's finalization list.
3727 -------------------------------------------
3728 -- Check_Allocator_Discrim_Accessibility --
3729 -------------------------------------------
3731 procedure Check_Allocator_Discrim_Accessibility
3732 (Disc_Exp : Node_Id;
3733 Alloc_Typ : Entity_Id)
3736 if Type_Access_Level (Etype (Disc_Exp)) >
3737 Type_Access_Level (Alloc_Typ)
3740 ("operand type has deeper level than allocator type", Disc_Exp);
3742 -- When the expression is an Access attribute the level of the prefix
3743 -- object must not be deeper than that of the allocator's type.
3745 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3746 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3748 and then Object_Access_Level (Prefix (Disc_Exp))
3749 > Type_Access_Level (Alloc_Typ)
3752 ("prefix of attribute has deeper level than allocator type",
3755 -- When the expression is an access discriminant the check is against
3756 -- the level of the prefix object.
3758 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3759 and then Nkind (Disc_Exp) = N_Selected_Component
3760 and then Object_Access_Level (Prefix (Disc_Exp))
3761 > Type_Access_Level (Alloc_Typ)
3764 ("access discriminant has deeper level than allocator type",
3767 -- All other cases are legal
3772 end Check_Allocator_Discrim_Accessibility;
3774 ----------------------------
3775 -- In_Dispatching_Context --
3776 ----------------------------
3778 function In_Dispatching_Context return Boolean is
3779 Par : constant Node_Id := Parent (N);
3781 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3782 and then Is_Entity_Name (Name (Par))
3783 and then Is_Dispatching_Operation (Entity (Name (Par)));
3784 end In_Dispatching_Context;
3786 ----------------------------
3787 -- Propagate_Coextensions --
3788 ----------------------------
3790 procedure Propagate_Coextensions (Root : Node_Id) is
3792 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3793 -- Copy the contents of list From into list To, preserving the
3794 -- order of elements.
3796 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3797 -- Recognize an allocator or a rewritten allocator node and add it
3798 -- along with its nested coextensions to the list of Root.
3804 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3805 From_Elmt : Elmt_Id;
3807 From_Elmt := First_Elmt (From);
3808 while Present (From_Elmt) loop
3809 Append_Elmt (Node (From_Elmt), To);
3810 Next_Elmt (From_Elmt);
3814 -----------------------
3815 -- Process_Allocator --
3816 -----------------------
3818 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3819 Orig_Nod : Node_Id := Nod;
3822 -- This is a possible rewritten subtype indication allocator. Any
3823 -- nested coextensions will appear as discriminant constraints.
3825 if Nkind (Nod) = N_Identifier
3826 and then Present (Original_Node (Nod))
3827 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3831 Discr_Elmt : Elmt_Id;
3834 if Is_Record_Type (Entity (Nod)) then
3836 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3837 while Present (Discr_Elmt) loop
3838 Discr := Node (Discr_Elmt);
3840 if Nkind (Discr) = N_Identifier
3841 and then Present (Original_Node (Discr))
3842 and then Nkind (Original_Node (Discr)) = N_Allocator
3843 and then Present (Coextensions (
3844 Original_Node (Discr)))
3846 if No (Coextensions (Root)) then
3847 Set_Coextensions (Root, New_Elmt_List);
3851 (From => Coextensions (Original_Node (Discr)),
3852 To => Coextensions (Root));
3855 Next_Elmt (Discr_Elmt);
3858 -- There is no need to continue the traversal of this
3859 -- subtree since all the information has already been
3866 -- Case of either a stand alone allocator or a rewritten allocator
3867 -- with an aggregate.
3870 if Present (Original_Node (Nod)) then
3871 Orig_Nod := Original_Node (Nod);
3874 if Nkind (Orig_Nod) = N_Allocator then
3876 -- Propagate the list of nested coextensions to the Root
3877 -- allocator. This is done through list copy since a single
3878 -- allocator may have multiple coextensions. Do not touch
3879 -- coextensions roots.
3881 if not Is_Coextension_Root (Orig_Nod)
3882 and then Present (Coextensions (Orig_Nod))
3884 if No (Coextensions (Root)) then
3885 Set_Coextensions (Root, New_Elmt_List);
3889 (From => Coextensions (Orig_Nod),
3890 To => Coextensions (Root));
3893 -- There is no need to continue the traversal of this
3894 -- subtree since all the information has already been
3901 -- Keep on traversing, looking for the next allocator
3904 end Process_Allocator;
3906 procedure Process_Allocators is
3907 new Traverse_Proc (Process_Allocator);
3909 -- Start of processing for Propagate_Coextensions
3912 Process_Allocators (Expression (Root));
3913 end Propagate_Coextensions;
3915 -- Start of processing for Resolve_Allocator
3918 -- Replace general access with specific type
3920 if Ekind (Etype (N)) = E_Allocator_Type then
3921 Set_Etype (N, Base_Type (Typ));
3924 if Is_Abstract_Type (Typ) then
3925 Error_Msg_N ("type of allocator cannot be abstract", N);
3928 -- For qualified expression, resolve the expression using the
3929 -- given subtype (nothing to do for type mark, subtype indication)
3931 if Nkind (E) = N_Qualified_Expression then
3932 if Is_Class_Wide_Type (Etype (E))
3933 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3934 and then not In_Dispatching_Context
3937 ("class-wide allocator not allowed for this access type", N);
3940 Resolve (Expression (E), Etype (E));
3941 Check_Unset_Reference (Expression (E));
3943 -- A qualified expression requires an exact match of the type,
3944 -- class-wide matching is not allowed.
3946 if (Is_Class_Wide_Type (Etype (Expression (E)))
3947 or else Is_Class_Wide_Type (Etype (E)))
3948 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3950 Wrong_Type (Expression (E), Etype (E));
3953 -- A special accessibility check is needed for allocators that
3954 -- constrain access discriminants. The level of the type of the
3955 -- expression used to constrain an access discriminant cannot be
3956 -- deeper than the type of the allocator (in contrast to access
3957 -- parameters, where the level of the actual can be arbitrary).
3959 -- We can't use Valid_Conversion to perform this check because
3960 -- in general the type of the allocator is unrelated to the type
3961 -- of the access discriminant.
3963 if Ekind (Typ) /= E_Anonymous_Access_Type
3964 or else Is_Local_Anonymous_Access (Typ)
3966 Subtyp := Entity (Subtype_Mark (E));
3968 Aggr := Original_Node (Expression (E));
3970 if Has_Discriminants (Subtyp)
3971 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
3973 Discrim := First_Discriminant (Base_Type (Subtyp));
3975 -- Get the first component expression of the aggregate
3977 if Present (Expressions (Aggr)) then
3978 Disc_Exp := First (Expressions (Aggr));
3980 elsif Present (Component_Associations (Aggr)) then
3981 Assoc := First (Component_Associations (Aggr));
3983 if Present (Assoc) then
3984 Disc_Exp := Expression (Assoc);
3993 while Present (Discrim) and then Present (Disc_Exp) loop
3994 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3995 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
3998 Next_Discriminant (Discrim);
4000 if Present (Discrim) then
4001 if Present (Assoc) then
4003 Disc_Exp := Expression (Assoc);
4005 elsif Present (Next (Disc_Exp)) then
4009 Assoc := First (Component_Associations (Aggr));
4011 if Present (Assoc) then
4012 Disc_Exp := Expression (Assoc);
4022 -- For a subtype mark or subtype indication, freeze the subtype
4025 Freeze_Expression (E);
4027 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4029 ("initialization required for access-to-constant allocator", N);
4032 -- A special accessibility check is needed for allocators that
4033 -- constrain access discriminants. The level of the type of the
4034 -- expression used to constrain an access discriminant cannot be
4035 -- deeper than the type of the allocator (in contrast to access
4036 -- parameters, where the level of the actual can be arbitrary).
4037 -- We can't use Valid_Conversion to perform this check because
4038 -- in general the type of the allocator is unrelated to the type
4039 -- of the access discriminant.
4041 if Nkind (Original_Node (E)) = N_Subtype_Indication
4042 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4043 or else Is_Local_Anonymous_Access (Typ))
4045 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4047 if Has_Discriminants (Subtyp) then
4048 Discrim := First_Discriminant (Base_Type (Subtyp));
4049 Constr := First (Constraints (Constraint (Original_Node (E))));
4050 while Present (Discrim) and then Present (Constr) loop
4051 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4052 if Nkind (Constr) = N_Discriminant_Association then
4053 Disc_Exp := Original_Node (Expression (Constr));
4055 Disc_Exp := Original_Node (Constr);
4058 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4061 Next_Discriminant (Discrim);
4068 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4069 -- check that the level of the type of the created object is not deeper
4070 -- than the level of the allocator's access type, since extensions can
4071 -- now occur at deeper levels than their ancestor types. This is a
4072 -- static accessibility level check; a run-time check is also needed in
4073 -- the case of an initialized allocator with a class-wide argument (see
4074 -- Expand_Allocator_Expression).
4076 if Ada_Version >= Ada_05
4077 and then Is_Class_Wide_Type (Designated_Type (Typ))
4080 Exp_Typ : Entity_Id;
4083 if Nkind (E) = N_Qualified_Expression then
4084 Exp_Typ := Etype (E);
4085 elsif Nkind (E) = N_Subtype_Indication then
4086 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4088 Exp_Typ := Entity (E);
4091 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4092 if In_Instance_Body then
4093 Error_Msg_N ("?type in allocator has deeper level than" &
4094 " designated class-wide type", E);
4095 Error_Msg_N ("\?Program_Error will be raised at run time",
4098 Make_Raise_Program_Error (Sloc (N),
4099 Reason => PE_Accessibility_Check_Failed));
4102 -- Do not apply Ada 2005 accessibility checks on a class-wide
4103 -- allocator if the type given in the allocator is a formal
4104 -- type. A run-time check will be performed in the instance.
4106 elsif not Is_Generic_Type (Exp_Typ) then
4107 Error_Msg_N ("type in allocator has deeper level than" &
4108 " designated class-wide type", E);
4114 -- Check for allocation from an empty storage pool
4116 if No_Pool_Assigned (Typ) then
4118 Loc : constant Source_Ptr := Sloc (N);
4120 Error_Msg_N ("?allocation from empty storage pool!", N);
4121 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4123 Make_Raise_Storage_Error (Loc,
4124 Reason => SE_Empty_Storage_Pool));
4127 -- If the context is an unchecked conversion, as may happen within
4128 -- an inlined subprogram, the allocator is being resolved with its
4129 -- own anonymous type. In that case, if the target type has a specific
4130 -- storage pool, it must be inherited explicitly by the allocator type.
4132 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4133 and then No (Associated_Storage_Pool (Typ))
4135 Set_Associated_Storage_Pool
4136 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4139 -- An erroneous allocator may be rewritten as a raise Program_Error
4142 if Nkind (N) = N_Allocator then
4144 -- An anonymous access discriminant is the definition of a
4147 if Ekind (Typ) = E_Anonymous_Access_Type
4148 and then Nkind (Associated_Node_For_Itype (Typ)) =
4149 N_Discriminant_Specification
4151 -- Avoid marking an allocator as a dynamic coextension if it is
4152 -- within a static construct.
4154 if not Is_Static_Coextension (N) then
4155 Set_Is_Dynamic_Coextension (N);
4158 -- Cleanup for potential static coextensions
4161 Set_Is_Dynamic_Coextension (N, False);
4162 Set_Is_Static_Coextension (N, False);
4165 -- There is no need to propagate any nested coextensions if they
4166 -- are marked as static since they will be rewritten on the spot.
4168 if not Is_Static_Coextension (N) then
4169 Propagate_Coextensions (N);
4172 end Resolve_Allocator;
4174 ---------------------------
4175 -- Resolve_Arithmetic_Op --
4176 ---------------------------
4178 -- Used for resolving all arithmetic operators except exponentiation
4180 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4181 L : constant Node_Id := Left_Opnd (N);
4182 R : constant Node_Id := Right_Opnd (N);
4183 TL : constant Entity_Id := Base_Type (Etype (L));
4184 TR : constant Entity_Id := Base_Type (Etype (R));
4188 B_Typ : constant Entity_Id := Base_Type (Typ);
4189 -- We do the resolution using the base type, because intermediate values
4190 -- in expressions always are of the base type, not a subtype of it.
4192 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4193 -- Returns True if N is in a context that expects "any real type"
4195 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4196 -- Return True iff given type is Integer or universal real/integer
4198 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4199 -- Choose type of integer literal in fixed-point operation to conform
4200 -- to available fixed-point type. T is the type of the other operand,
4201 -- which is needed to determine the expected type of N.
4203 procedure Set_Operand_Type (N : Node_Id);
4204 -- Set operand type to T if universal
4206 -------------------------------
4207 -- Expected_Type_Is_Any_Real --
4208 -------------------------------
4210 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4212 -- N is the expression after "delta" in a fixed_point_definition;
4215 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4216 N_Decimal_Fixed_Point_Definition,
4218 -- N is one of the bounds in a real_range_specification;
4221 N_Real_Range_Specification,
4223 -- N is the expression of a delta_constraint;
4226 N_Delta_Constraint);
4227 end Expected_Type_Is_Any_Real;
4229 -----------------------------
4230 -- Is_Integer_Or_Universal --
4231 -----------------------------
4233 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4235 Index : Interp_Index;
4239 if not Is_Overloaded (N) then
4241 return Base_Type (T) = Base_Type (Standard_Integer)
4242 or else T = Universal_Integer
4243 or else T = Universal_Real;
4245 Get_First_Interp (N, Index, It);
4246 while Present (It.Typ) loop
4247 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4248 or else It.Typ = Universal_Integer
4249 or else It.Typ = Universal_Real
4254 Get_Next_Interp (Index, It);
4259 end Is_Integer_Or_Universal;
4261 ----------------------------
4262 -- Set_Mixed_Mode_Operand --
4263 ----------------------------
4265 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4266 Index : Interp_Index;
4270 if Universal_Interpretation (N) = Universal_Integer then
4272 -- A universal integer literal is resolved as standard integer
4273 -- except in the case of a fixed-point result, where we leave it
4274 -- as universal (to be handled by Exp_Fixd later on)
4276 if Is_Fixed_Point_Type (T) then
4277 Resolve (N, Universal_Integer);
4279 Resolve (N, Standard_Integer);
4282 elsif Universal_Interpretation (N) = Universal_Real
4283 and then (T = Base_Type (Standard_Integer)
4284 or else T = Universal_Integer
4285 or else T = Universal_Real)
4287 -- A universal real can appear in a fixed-type context. We resolve
4288 -- the literal with that context, even though this might raise an
4289 -- exception prematurely (the other operand may be zero).
4293 elsif Etype (N) = Base_Type (Standard_Integer)
4294 and then T = Universal_Real
4295 and then Is_Overloaded (N)
4297 -- Integer arg in mixed-mode operation. Resolve with universal
4298 -- type, in case preference rule must be applied.
4300 Resolve (N, Universal_Integer);
4303 and then B_Typ /= Universal_Fixed
4305 -- Not a mixed-mode operation, resolve with context
4309 elsif Etype (N) = Any_Fixed then
4311 -- N may itself be a mixed-mode operation, so use context type
4315 elsif Is_Fixed_Point_Type (T)
4316 and then B_Typ = Universal_Fixed
4317 and then Is_Overloaded (N)
4319 -- Must be (fixed * fixed) operation, operand must have one
4320 -- compatible interpretation.
4322 Resolve (N, Any_Fixed);
4324 elsif Is_Fixed_Point_Type (B_Typ)
4325 and then (T = Universal_Real
4326 or else Is_Fixed_Point_Type (T))
4327 and then Is_Overloaded (N)
4329 -- C * F(X) in a fixed context, where C is a real literal or a
4330 -- fixed-point expression. F must have either a fixed type
4331 -- interpretation or an integer interpretation, but not both.
4333 Get_First_Interp (N, Index, It);
4334 while Present (It.Typ) loop
4335 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4337 if Analyzed (N) then
4338 Error_Msg_N ("ambiguous operand in fixed operation", N);
4340 Resolve (N, Standard_Integer);
4343 elsif Is_Fixed_Point_Type (It.Typ) then
4345 if Analyzed (N) then
4346 Error_Msg_N ("ambiguous operand in fixed operation", N);
4348 Resolve (N, It.Typ);
4352 Get_Next_Interp (Index, It);
4355 -- Reanalyze the literal with the fixed type of the context. If
4356 -- context is Universal_Fixed, we are within a conversion, leave
4357 -- the literal as a universal real because there is no usable
4358 -- fixed type, and the target of the conversion plays no role in
4372 if B_Typ = Universal_Fixed
4373 and then Nkind (Op2) = N_Real_Literal
4375 T2 := Universal_Real;
4380 Set_Analyzed (Op2, False);
4387 end Set_Mixed_Mode_Operand;
4389 ----------------------
4390 -- Set_Operand_Type --
4391 ----------------------
4393 procedure Set_Operand_Type (N : Node_Id) is
4395 if Etype (N) = Universal_Integer
4396 or else Etype (N) = Universal_Real
4400 end Set_Operand_Type;
4402 -- Start of processing for Resolve_Arithmetic_Op
4405 if Comes_From_Source (N)
4406 and then Ekind (Entity (N)) = E_Function
4407 and then Is_Imported (Entity (N))
4408 and then Is_Intrinsic_Subprogram (Entity (N))
4410 Resolve_Intrinsic_Operator (N, Typ);
4413 -- Special-case for mixed-mode universal expressions or fixed point
4414 -- type operation: each argument is resolved separately. The same
4415 -- treatment is required if one of the operands of a fixed point
4416 -- operation is universal real, since in this case we don't do a
4417 -- conversion to a specific fixed-point type (instead the expander
4418 -- takes care of the case).
4420 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4421 and then Present (Universal_Interpretation (L))
4422 and then Present (Universal_Interpretation (R))
4424 Resolve (L, Universal_Interpretation (L));
4425 Resolve (R, Universal_Interpretation (R));
4426 Set_Etype (N, B_Typ);
4428 elsif (B_Typ = Universal_Real
4429 or else Etype (N) = Universal_Fixed
4430 or else (Etype (N) = Any_Fixed
4431 and then Is_Fixed_Point_Type (B_Typ))
4432 or else (Is_Fixed_Point_Type (B_Typ)
4433 and then (Is_Integer_Or_Universal (L)
4435 Is_Integer_Or_Universal (R))))
4436 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4438 if TL = Universal_Integer or else TR = Universal_Integer then
4439 Check_For_Visible_Operator (N, B_Typ);
4442 -- If context is a fixed type and one operand is integer, the
4443 -- other is resolved with the type of the context.
4445 if Is_Fixed_Point_Type (B_Typ)
4446 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4447 or else TL = Universal_Integer)
4452 elsif Is_Fixed_Point_Type (B_Typ)
4453 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4454 or else TR = Universal_Integer)
4460 Set_Mixed_Mode_Operand (L, TR);
4461 Set_Mixed_Mode_Operand (R, TL);
4464 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4465 -- multiplying operators from being used when the expected type is
4466 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4467 -- some cases where the expected type is actually Any_Real;
4468 -- Expected_Type_Is_Any_Real takes care of that case.
4470 if Etype (N) = Universal_Fixed
4471 or else Etype (N) = Any_Fixed
4473 if B_Typ = Universal_Fixed
4474 and then not Expected_Type_Is_Any_Real (N)
4475 and then not Nkind_In (Parent (N), N_Type_Conversion,
4476 N_Unchecked_Type_Conversion)
4478 Error_Msg_N ("type cannot be determined from context!", N);
4479 Error_Msg_N ("\explicit conversion to result type required", N);
4481 Set_Etype (L, Any_Type);
4482 Set_Etype (R, Any_Type);
4485 if Ada_Version = Ada_83
4486 and then Etype (N) = Universal_Fixed
4488 Nkind_In (Parent (N), N_Type_Conversion,
4489 N_Unchecked_Type_Conversion)
4492 ("(Ada 83) fixed-point operation "
4493 & "needs explicit conversion", N);
4496 -- The expected type is "any real type" in contexts like
4497 -- type T is delta <universal_fixed-expression> ...
4498 -- in which case we need to set the type to Universal_Real
4499 -- so that static expression evaluation will work properly.
4501 if Expected_Type_Is_Any_Real (N) then
4502 Set_Etype (N, Universal_Real);
4504 Set_Etype (N, B_Typ);
4508 elsif Is_Fixed_Point_Type (B_Typ)
4509 and then (Is_Integer_Or_Universal (L)
4510 or else Nkind (L) = N_Real_Literal
4511 or else Nkind (R) = N_Real_Literal
4512 or else Is_Integer_Or_Universal (R))
4514 Set_Etype (N, B_Typ);
4516 elsif Etype (N) = Any_Fixed then
4518 -- If no previous errors, this is only possible if one operand
4519 -- is overloaded and the context is universal. Resolve as such.
4521 Set_Etype (N, B_Typ);
4525 if (TL = Universal_Integer or else TL = Universal_Real)
4527 (TR = Universal_Integer or else TR = Universal_Real)
4529 Check_For_Visible_Operator (N, B_Typ);
4532 -- If the context is Universal_Fixed and the operands are also
4533 -- universal fixed, this is an error, unless there is only one
4534 -- applicable fixed_point type (usually duration).
4536 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4537 T := Unique_Fixed_Point_Type (N);
4539 if T = Any_Type then
4552 -- If one of the arguments was resolved to a non-universal type.
4553 -- label the result of the operation itself with the same type.
4554 -- Do the same for the universal argument, if any.
4556 T := Intersect_Types (L, R);
4557 Set_Etype (N, Base_Type (T));
4558 Set_Operand_Type (L);
4559 Set_Operand_Type (R);
4562 Generate_Operator_Reference (N, Typ);
4563 Eval_Arithmetic_Op (N);
4565 -- Set overflow and division checking bit. Much cleverer code needed
4566 -- here eventually and perhaps the Resolve routines should be separated
4567 -- for the various arithmetic operations, since they will need
4568 -- different processing. ???
4570 if Nkind (N) in N_Op then
4571 if not Overflow_Checks_Suppressed (Etype (N)) then
4572 Enable_Overflow_Check (N);
4575 -- Give warning if explicit division by zero
4577 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4578 and then not Division_Checks_Suppressed (Etype (N))
4580 Rop := Right_Opnd (N);
4582 if Compile_Time_Known_Value (Rop)
4583 and then ((Is_Integer_Type (Etype (Rop))
4584 and then Expr_Value (Rop) = Uint_0)
4586 (Is_Real_Type (Etype (Rop))
4587 and then Expr_Value_R (Rop) = Ureal_0))
4589 -- Specialize the warning message according to the operation
4593 Apply_Compile_Time_Constraint_Error
4594 (N, "division by zero?", CE_Divide_By_Zero,
4595 Loc => Sloc (Right_Opnd (N)));
4598 Apply_Compile_Time_Constraint_Error
4599 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4600 Loc => Sloc (Right_Opnd (N)));
4603 Apply_Compile_Time_Constraint_Error
4604 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4605 Loc => Sloc (Right_Opnd (N)));
4607 -- Division by zero can only happen with division, rem,
4608 -- and mod operations.
4611 raise Program_Error;
4614 -- Otherwise just set the flag to check at run time
4617 Activate_Division_Check (N);
4621 -- If Restriction No_Implicit_Conditionals is active, then it is
4622 -- violated if either operand can be negative for mod, or for rem
4623 -- if both operands can be negative.
4625 if Restrictions.Set (No_Implicit_Conditionals)
4626 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4635 -- Set if corresponding operand might be negative
4638 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4639 LNeg := (not OK) or else Lo < 0;
4641 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4642 RNeg := (not OK) or else Lo < 0;
4644 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4646 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4648 Check_Restriction (No_Implicit_Conditionals, N);
4654 Check_Unset_Reference (L);
4655 Check_Unset_Reference (R);
4656 end Resolve_Arithmetic_Op;
4662 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4663 Loc : constant Source_Ptr := Sloc (N);
4664 Subp : constant Node_Id := Name (N);
4673 -- The context imposes a unique interpretation with type Typ on a
4674 -- procedure or function call. Find the entity of the subprogram that
4675 -- yields the expected type, and propagate the corresponding formal
4676 -- constraints on the actuals. The caller has established that an
4677 -- interpretation exists, and emitted an error if not unique.
4679 -- First deal with the case of a call to an access-to-subprogram,
4680 -- dereference made explicit in Analyze_Call.
4682 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4683 if not Is_Overloaded (Subp) then
4684 Nam := Etype (Subp);
4687 -- Find the interpretation whose type (a subprogram type) has a
4688 -- return type that is compatible with the context. Analysis of
4689 -- the node has established that one exists.
4693 Get_First_Interp (Subp, I, It);
4694 while Present (It.Typ) loop
4695 if Covers (Typ, Etype (It.Typ)) then
4700 Get_Next_Interp (I, It);
4704 raise Program_Error;
4708 -- If the prefix is not an entity, then resolve it
4710 if not Is_Entity_Name (Subp) then
4711 Resolve (Subp, Nam);
4714 -- For an indirect call, we always invalidate checks, since we do not
4715 -- know whether the subprogram is local or global. Yes we could do
4716 -- better here, e.g. by knowing that there are no local subprograms,
4717 -- but it does not seem worth the effort. Similarly, we kill all
4718 -- knowledge of current constant values.
4720 Kill_Current_Values;
4722 -- If this is a procedure call which is really an entry call, do
4723 -- the conversion of the procedure call to an entry call. Protected
4724 -- operations use the same circuitry because the name in the call
4725 -- can be an arbitrary expression with special resolution rules.
4727 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4728 or else (Is_Entity_Name (Subp)
4729 and then Ekind (Entity (Subp)) = E_Entry)
4731 Resolve_Entry_Call (N, Typ);
4732 Check_Elab_Call (N);
4734 -- Kill checks and constant values, as above for indirect case
4735 -- Who knows what happens when another task is activated?
4737 Kill_Current_Values;
4740 -- Normal subprogram call with name established in Resolve
4742 elsif not (Is_Type (Entity (Subp))) then
4743 Nam := Entity (Subp);
4744 Set_Entity_With_Style_Check (Subp, Nam);
4746 -- Otherwise we must have the case of an overloaded call
4749 pragma Assert (Is_Overloaded (Subp));
4751 -- Initialize Nam to prevent warning (we know it will be assigned
4752 -- in the loop below, but the compiler does not know that).
4756 Get_First_Interp (Subp, I, It);
4757 while Present (It.Typ) loop
4758 if Covers (Typ, It.Typ) then
4760 Set_Entity_With_Style_Check (Subp, Nam);
4764 Get_Next_Interp (I, It);
4768 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4769 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4770 and then Nkind (Subp) /= N_Explicit_Dereference
4771 and then Present (Parameter_Associations (N))
4773 -- The prefix is a parameterless function call that returns an access
4774 -- to subprogram. If parameters are present in the current call, add
4775 -- add an explicit dereference. We use the base type here because
4776 -- within an instance these may be subtypes.
4778 -- The dereference is added either in Analyze_Call or here. Should
4779 -- be consolidated ???
4781 Set_Is_Overloaded (Subp, False);
4782 Set_Etype (Subp, Etype (Nam));
4783 Insert_Explicit_Dereference (Subp);
4784 Nam := Designated_Type (Etype (Nam));
4785 Resolve (Subp, Nam);
4788 -- Check that a call to Current_Task does not occur in an entry body
4790 if Is_RTE (Nam, RE_Current_Task) then
4799 -- Exclude calls that occur within the default of a formal
4800 -- parameter of the entry, since those are evaluated outside
4803 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4805 if Nkind (P) = N_Entry_Body
4806 or else (Nkind (P) = N_Subprogram_Body
4807 and then Is_Entry_Barrier_Function (P))
4811 ("?& should not be used in entry body (RM C.7(17))",
4814 ("\Program_Error will be raised at run time?", N, Nam);
4816 Make_Raise_Program_Error (Loc,
4817 Reason => PE_Current_Task_In_Entry_Body));
4818 Set_Etype (N, Rtype);
4825 -- Check that a procedure call does not occur in the context of the
4826 -- entry call statement of a conditional or timed entry call. Note that
4827 -- the case of a call to a subprogram renaming of an entry will also be
4828 -- rejected. The test for N not being an N_Entry_Call_Statement is
4829 -- defensive, covering the possibility that the processing of entry
4830 -- calls might reach this point due to later modifications of the code
4833 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4834 and then Nkind (N) /= N_Entry_Call_Statement
4835 and then Entry_Call_Statement (Parent (N)) = N
4837 if Ada_Version < Ada_05 then
4838 Error_Msg_N ("entry call required in select statement", N);
4840 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4841 -- for a procedure_or_entry_call, the procedure_name or
4842 -- procedure_prefix of the procedure_call_statement shall denote
4843 -- an entry renamed by a procedure, or (a view of) a primitive
4844 -- subprogram of a limited interface whose first parameter is
4845 -- a controlling parameter.
4847 elsif Nkind (N) = N_Procedure_Call_Statement
4848 and then not Is_Renamed_Entry (Nam)
4849 and then not Is_Controlling_Limited_Procedure (Nam)
4852 ("entry call or dispatching primitive of interface required", N);
4856 -- Check that this is not a call to a protected procedure or entry from
4857 -- within a protected function.
4859 if Ekind (Current_Scope) = E_Function
4860 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4861 and then Ekind (Nam) /= E_Function
4862 and then Scope (Nam) = Scope (Current_Scope)
4864 Error_Msg_N ("within protected function, protected " &
4865 "object is constant", N);
4866 Error_Msg_N ("\cannot call operation that may modify it", N);
4869 -- Freeze the subprogram name if not in a spec-expression. Note that we
4870 -- freeze procedure calls as well as function calls. Procedure calls are
4871 -- not frozen according to the rules (RM 13.14(14)) because it is
4872 -- impossible to have a procedure call to a non-frozen procedure in pure
4873 -- Ada, but in the code that we generate in the expander, this rule
4874 -- needs extending because we can generate procedure calls that need
4877 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4878 Freeze_Expression (Subp);
4881 -- For a predefined operator, the type of the result is the type imposed
4882 -- by context, except for a predefined operation on universal fixed.
4883 -- Otherwise The type of the call is the type returned by the subprogram
4886 if Is_Predefined_Op (Nam) then
4887 if Etype (N) /= Universal_Fixed then
4891 -- If the subprogram returns an array type, and the context requires the
4892 -- component type of that array type, the node is really an indexing of
4893 -- the parameterless call. Resolve as such. A pathological case occurs
4894 -- when the type of the component is an access to the array type. In
4895 -- this case the call is truly ambiguous.
4897 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4899 ((Is_Array_Type (Etype (Nam))
4900 and then Covers (Typ, Component_Type (Etype (Nam))))
4901 or else (Is_Access_Type (Etype (Nam))
4902 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4905 Component_Type (Designated_Type (Etype (Nam))))))
4908 Index_Node : Node_Id;
4910 Ret_Type : constant Entity_Id := Etype (Nam);
4913 if Is_Access_Type (Ret_Type)
4914 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4917 ("cannot disambiguate function call and indexing", N);
4919 New_Subp := Relocate_Node (Subp);
4920 Set_Entity (Subp, Nam);
4922 if Component_Type (Ret_Type) /= Any_Type then
4923 if Needs_No_Actuals (Nam) then
4925 -- Indexed call to a parameterless function
4928 Make_Indexed_Component (Loc,
4930 Make_Function_Call (Loc,
4932 Expressions => Parameter_Associations (N));
4934 -- An Ada 2005 prefixed call to a primitive operation
4935 -- whose first parameter is the prefix. This prefix was
4936 -- prepended to the parameter list, which is actually a
4937 -- list of indices. Remove the prefix in order to build
4938 -- the proper indexed component.
4941 Make_Indexed_Component (Loc,
4943 Make_Function_Call (Loc,
4945 Parameter_Associations =>
4947 (Remove_Head (Parameter_Associations (N)))),
4948 Expressions => Parameter_Associations (N));
4951 -- Since we are correcting a node classification error made
4952 -- by the parser, we call Replace rather than Rewrite.
4954 Replace (N, Index_Node);
4955 Set_Etype (Prefix (N), Ret_Type);
4957 Resolve_Indexed_Component (N, Typ);
4958 Check_Elab_Call (Prefix (N));
4966 Set_Etype (N, Etype (Nam));
4969 -- In the case where the call is to an overloaded subprogram, Analyze
4970 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
4971 -- such a case Normalize_Actuals needs to be called once more to order
4972 -- the actuals correctly. Otherwise the call will have the ordering
4973 -- given by the last overloaded subprogram whether this is the correct
4974 -- one being called or not.
4976 if Is_Overloaded (Subp) then
4977 Normalize_Actuals (N, Nam, False, Norm_OK);
4978 pragma Assert (Norm_OK);
4981 -- In any case, call is fully resolved now. Reset Overload flag, to
4982 -- prevent subsequent overload resolution if node is analyzed again
4984 Set_Is_Overloaded (Subp, False);
4985 Set_Is_Overloaded (N, False);
4987 -- If we are calling the current subprogram from immediately within its
4988 -- body, then that is the case where we can sometimes detect cases of
4989 -- infinite recursion statically. Do not try this in case restriction
4990 -- No_Recursion is in effect anyway, and do it only for source calls.
4992 if Comes_From_Source (N) then
4993 Scop := Current_Scope;
4995 -- Issue warning for possible infinite recursion in the absence
4996 -- of the No_Recursion restriction.
4999 and then not Restriction_Active (No_Recursion)
5000 and then Check_Infinite_Recursion (N)
5002 -- Here we detected and flagged an infinite recursion, so we do
5003 -- not need to test the case below for further warnings. Also if
5004 -- we now have a raise SE node, we are all done.
5006 if Nkind (N) = N_Raise_Storage_Error then
5010 -- If call is to immediately containing subprogram, then check for
5011 -- the case of a possible run-time detectable infinite recursion.
5014 Scope_Loop : while Scop /= Standard_Standard loop
5017 -- Although in general case, recursion is not statically
5018 -- checkable, the case of calling an immediately containing
5019 -- subprogram is easy to catch.
5021 Check_Restriction (No_Recursion, N);
5023 -- If the recursive call is to a parameterless subprogram,
5024 -- then even if we can't statically detect infinite
5025 -- recursion, this is pretty suspicious, and we output a
5026 -- warning. Furthermore, we will try later to detect some
5027 -- cases here at run time by expanding checking code (see
5028 -- Detect_Infinite_Recursion in package Exp_Ch6).
5030 -- If the recursive call is within a handler, do not emit a
5031 -- warning, because this is a common idiom: loop until input
5032 -- is correct, catch illegal input in handler and restart.
5034 if No (First_Formal (Nam))
5035 and then Etype (Nam) = Standard_Void_Type
5036 and then not Error_Posted (N)
5037 and then Nkind (Parent (N)) /= N_Exception_Handler
5039 -- For the case of a procedure call. We give the message
5040 -- only if the call is the first statement in a sequence
5041 -- of statements, or if all previous statements are
5042 -- simple assignments. This is simply a heuristic to
5043 -- decrease false positives, without losing too many good
5044 -- warnings. The idea is that these previous statements
5045 -- may affect global variables the procedure depends on.
5047 if Nkind (N) = N_Procedure_Call_Statement
5048 and then Is_List_Member (N)
5054 while Present (P) loop
5055 if Nkind (P) /= N_Assignment_Statement then
5064 -- Do not give warning if we are in a conditional context
5067 K : constant Node_Kind := Nkind (Parent (N));
5069 if (K = N_Loop_Statement
5070 and then Present (Iteration_Scheme (Parent (N))))
5071 or else K = N_If_Statement
5072 or else K = N_Elsif_Part
5073 or else K = N_Case_Statement_Alternative
5079 -- Here warning is to be issued
5081 Set_Has_Recursive_Call (Nam);
5083 ("?possible infinite recursion!", N);
5085 ("\?Storage_Error may be raised at run time!", N);
5091 Scop := Scope (Scop);
5092 end loop Scope_Loop;
5096 -- If subprogram name is a predefined operator, it was given in
5097 -- functional notation. Replace call node with operator node, so
5098 -- that actuals can be resolved appropriately.
5100 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5101 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5104 elsif Present (Alias (Nam))
5105 and then Is_Predefined_Op (Alias (Nam))
5107 Resolve_Actuals (N, Nam);
5108 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5112 -- Create a transient scope if the resulting type requires it
5114 -- There are several notable exceptions:
5116 -- a) In init procs, the transient scope overhead is not needed, and is
5117 -- even incorrect when the call is a nested initialization call for a
5118 -- component whose expansion may generate adjust calls. However, if the
5119 -- call is some other procedure call within an initialization procedure
5120 -- (for example a call to Create_Task in the init_proc of the task
5121 -- run-time record) a transient scope must be created around this call.
5123 -- b) Enumeration literal pseudo-calls need no transient scope
5125 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5126 -- functions) do not use the secondary stack even though the return
5127 -- type may be unconstrained.
5129 -- d) Calls to a build-in-place function, since such functions may
5130 -- allocate their result directly in a target object, and cases where
5131 -- the result does get allocated in the secondary stack are checked for
5132 -- within the specialized Exp_Ch6 procedures for expanding those
5133 -- build-in-place calls.
5135 -- e) If the subprogram is marked Inline_Always, then even if it returns
5136 -- an unconstrained type the call does not require use of the secondary
5137 -- stack. However, inlining will only take place if the body to inline
5138 -- is already present. It may not be available if e.g. the subprogram is
5139 -- declared in a child instance.
5141 -- If this is an initialization call for a type whose construction
5142 -- uses the secondary stack, and it is not a nested call to initialize
5143 -- a component, we do need to create a transient scope for it. We
5144 -- check for this by traversing the type in Check_Initialization_Call.
5147 and then Has_Pragma_Inline_Always (Nam)
5148 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5149 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5153 elsif Ekind (Nam) = E_Enumeration_Literal
5154 or else Is_Build_In_Place_Function (Nam)
5155 or else Is_Intrinsic_Subprogram (Nam)
5159 elsif Expander_Active
5160 and then Is_Type (Etype (Nam))
5161 and then Requires_Transient_Scope (Etype (Nam))
5163 (not Within_Init_Proc
5165 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5167 Establish_Transient_Scope (N, Sec_Stack => True);
5169 -- If the call appears within the bounds of a loop, it will
5170 -- be rewritten and reanalyzed, nothing left to do here.
5172 if Nkind (N) /= N_Function_Call then
5176 elsif Is_Init_Proc (Nam)
5177 and then not Within_Init_Proc
5179 Check_Initialization_Call (N, Nam);
5182 -- A protected function cannot be called within the definition of the
5183 -- enclosing protected type.
5185 if Is_Protected_Type (Scope (Nam))
5186 and then In_Open_Scopes (Scope (Nam))
5187 and then not Has_Completion (Scope (Nam))
5190 ("& cannot be called before end of protected definition", N, Nam);
5193 -- Propagate interpretation to actuals, and add default expressions
5196 if Present (First_Formal (Nam)) then
5197 Resolve_Actuals (N, Nam);
5199 -- Overloaded literals are rewritten as function calls, for purpose of
5200 -- resolution. After resolution, we can replace the call with the
5203 elsif Ekind (Nam) = E_Enumeration_Literal then
5204 Copy_Node (Subp, N);
5205 Resolve_Entity_Name (N, Typ);
5207 -- Avoid validation, since it is a static function call
5209 Generate_Reference (Nam, Subp);
5213 -- If the subprogram is not global, then kill all saved values and
5214 -- checks. This is a bit conservative, since in many cases we could do
5215 -- better, but it is not worth the effort. Similarly, we kill constant
5216 -- values. However we do not need to do this for internal entities
5217 -- (unless they are inherited user-defined subprograms), since they
5218 -- are not in the business of molesting local values.
5220 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5221 -- kill all checks and values for calls to global subprograms. This
5222 -- takes care of the case where an access to a local subprogram is
5223 -- taken, and could be passed directly or indirectly and then called
5224 -- from almost any context.
5226 -- Note: we do not do this step till after resolving the actuals. That
5227 -- way we still take advantage of the current value information while
5228 -- scanning the actuals.
5230 -- We suppress killing values if we are processing the nodes associated
5231 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5232 -- type kills all the values as part of analyzing the code that
5233 -- initializes the dispatch tables.
5235 if Inside_Freezing_Actions = 0
5236 and then (not Is_Library_Level_Entity (Nam)
5237 or else Suppress_Value_Tracking_On_Call
5238 (Nearest_Dynamic_Scope (Current_Scope)))
5239 and then (Comes_From_Source (Nam)
5240 or else (Present (Alias (Nam))
5241 and then Comes_From_Source (Alias (Nam))))
5243 Kill_Current_Values;
5246 -- If we are warning about unread OUT parameters, this is the place to
5247 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5248 -- after the above call to Kill_Current_Values (since that call clears
5249 -- the Last_Assignment field of all local variables).
5251 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5252 and then Comes_From_Source (N)
5253 and then In_Extended_Main_Source_Unit (N)
5260 F := First_Formal (Nam);
5261 A := First_Actual (N);
5262 while Present (F) and then Present (A) loop
5263 if (Ekind (F) = E_Out_Parameter
5265 Ekind (F) = E_In_Out_Parameter)
5266 and then Warn_On_Modified_As_Out_Parameter (F)
5267 and then Is_Entity_Name (A)
5268 and then Present (Entity (A))
5269 and then Comes_From_Source (N)
5270 and then Safe_To_Capture_Value (N, Entity (A))
5272 Set_Last_Assignment (Entity (A), A);
5281 -- If the subprogram is a primitive operation, check whether or not
5282 -- it is a correct dispatching call.
5284 if Is_Overloadable (Nam)
5285 and then Is_Dispatching_Operation (Nam)
5287 Check_Dispatching_Call (N);
5289 elsif Ekind (Nam) /= E_Subprogram_Type
5290 and then Is_Abstract_Subprogram (Nam)
5291 and then not In_Instance
5293 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5296 -- If this is a dispatching call, generate the appropriate reference,
5297 -- for better source navigation in GPS.
5299 if Is_Overloadable (Nam)
5300 and then Present (Controlling_Argument (N))
5302 Generate_Reference (Nam, Subp, 'R');
5304 -- Normal case, not a dispatching call
5307 Generate_Reference (Nam, Subp);
5310 if Is_Intrinsic_Subprogram (Nam) then
5311 Check_Intrinsic_Call (N);
5314 -- Check for violation of restriction No_Specific_Termination_Handlers
5315 -- and warn on a potentially blocking call to Abort_Task.
5317 if Is_RTE (Nam, RE_Set_Specific_Handler)
5319 Is_RTE (Nam, RE_Specific_Handler)
5321 Check_Restriction (No_Specific_Termination_Handlers, N);
5323 elsif Is_RTE (Nam, RE_Abort_Task) then
5324 Check_Potentially_Blocking_Operation (N);
5327 -- Issue an error for a call to an eliminated subprogram
5329 Check_For_Eliminated_Subprogram (Subp, Nam);
5331 -- All done, evaluate call and deal with elaboration issues
5334 Check_Elab_Call (N);
5337 -------------------------------
5338 -- Resolve_Character_Literal --
5339 -------------------------------
5341 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5342 B_Typ : constant Entity_Id := Base_Type (Typ);
5346 -- Verify that the character does belong to the type of the context
5348 Set_Etype (N, B_Typ);
5349 Eval_Character_Literal (N);
5351 -- Wide_Wide_Character literals must always be defined, since the set
5352 -- of wide wide character literals is complete, i.e. if a character
5353 -- literal is accepted by the parser, then it is OK for wide wide
5354 -- character (out of range character literals are rejected).
5356 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5359 -- Always accept character literal for type Any_Character, which
5360 -- occurs in error situations and in comparisons of literals, both
5361 -- of which should accept all literals.
5363 elsif B_Typ = Any_Character then
5366 -- For Standard.Character or a type derived from it, check that
5367 -- the literal is in range
5369 elsif Root_Type (B_Typ) = Standard_Character then
5370 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5374 -- For Standard.Wide_Character or a type derived from it, check
5375 -- that the literal is in range
5377 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5378 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5382 -- For Standard.Wide_Wide_Character or a type derived from it, we
5383 -- know the literal is in range, since the parser checked!
5385 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5388 -- If the entity is already set, this has already been resolved in a
5389 -- generic context, or comes from expansion. Nothing else to do.
5391 elsif Present (Entity (N)) then
5394 -- Otherwise we have a user defined character type, and we can use the
5395 -- standard visibility mechanisms to locate the referenced entity.
5398 C := Current_Entity (N);
5399 while Present (C) loop
5400 if Etype (C) = B_Typ then
5401 Set_Entity_With_Style_Check (N, C);
5402 Generate_Reference (C, N);
5410 -- If we fall through, then the literal does not match any of the
5411 -- entries of the enumeration type. This isn't just a constraint
5412 -- error situation, it is an illegality (see RM 4.2).
5415 ("character not defined for }", N, First_Subtype (B_Typ));
5416 end Resolve_Character_Literal;
5418 ---------------------------
5419 -- Resolve_Comparison_Op --
5420 ---------------------------
5422 -- Context requires a boolean type, and plays no role in resolution.
5423 -- Processing identical to that for equality operators. The result
5424 -- type is the base type, which matters when pathological subtypes of
5425 -- booleans with limited ranges are used.
5427 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5428 L : constant Node_Id := Left_Opnd (N);
5429 R : constant Node_Id := Right_Opnd (N);
5433 -- If this is an intrinsic operation which is not predefined, use the
5434 -- types of its declared arguments to resolve the possibly overloaded
5435 -- operands. Otherwise the operands are unambiguous and specify the
5438 if Scope (Entity (N)) /= Standard_Standard then
5439 T := Etype (First_Entity (Entity (N)));
5442 T := Find_Unique_Type (L, R);
5444 if T = Any_Fixed then
5445 T := Unique_Fixed_Point_Type (L);
5449 Set_Etype (N, Base_Type (Typ));
5450 Generate_Reference (T, N, ' ');
5452 if T /= Any_Type then
5453 if T = Any_String or else
5454 T = Any_Composite or else
5457 if T = Any_Character then
5458 Ambiguous_Character (L);
5460 Error_Msg_N ("ambiguous operands for comparison", N);
5463 Set_Etype (N, Any_Type);
5469 Check_Unset_Reference (L);
5470 Check_Unset_Reference (R);
5471 Generate_Operator_Reference (N, T);
5472 Check_Low_Bound_Tested (N);
5473 Eval_Relational_Op (N);
5476 end Resolve_Comparison_Op;
5478 ------------------------------------
5479 -- Resolve_Conditional_Expression --
5480 ------------------------------------
5482 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5483 Condition : constant Node_Id := First (Expressions (N));
5484 Then_Expr : constant Node_Id := Next (Condition);
5485 Else_Expr : constant Node_Id := Next (Then_Expr);
5487 Resolve (Condition, Standard_Boolean);
5488 Resolve (Then_Expr, Typ);
5489 Resolve (Else_Expr, Typ);
5491 Eval_Conditional_Expression (N);
5492 end Resolve_Conditional_Expression;
5494 -----------------------------------------
5495 -- Resolve_Discrete_Subtype_Indication --
5496 -----------------------------------------
5498 procedure Resolve_Discrete_Subtype_Indication
5506 Analyze (Subtype_Mark (N));
5507 S := Entity (Subtype_Mark (N));
5509 if Nkind (Constraint (N)) /= N_Range_Constraint then
5510 Error_Msg_N ("expect range constraint for discrete type", N);
5511 Set_Etype (N, Any_Type);
5514 R := Range_Expression (Constraint (N));
5522 if Base_Type (S) /= Base_Type (Typ) then
5524 ("expect subtype of }", N, First_Subtype (Typ));
5526 -- Rewrite the constraint as a range of Typ
5527 -- to allow compilation to proceed further.
5530 Rewrite (Low_Bound (R),
5531 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5532 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5533 Attribute_Name => Name_First));
5534 Rewrite (High_Bound (R),
5535 Make_Attribute_Reference (Sloc (High_Bound (R)),
5536 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5537 Attribute_Name => Name_First));
5541 Set_Etype (N, Etype (R));
5543 -- Additionally, we must check that the bounds are compatible
5544 -- with the given subtype, which might be different from the
5545 -- type of the context.
5547 Apply_Range_Check (R, S);
5549 -- ??? If the above check statically detects a Constraint_Error
5550 -- it replaces the offending bound(s) of the range R with a
5551 -- Constraint_Error node. When the itype which uses these bounds
5552 -- is frozen the resulting call to Duplicate_Subexpr generates
5553 -- a new temporary for the bounds.
5555 -- Unfortunately there are other itypes that are also made depend
5556 -- on these bounds, so when Duplicate_Subexpr is called they get
5557 -- a forward reference to the newly created temporaries and Gigi
5558 -- aborts on such forward references. This is probably sign of a
5559 -- more fundamental problem somewhere else in either the order of
5560 -- itype freezing or the way certain itypes are constructed.
5562 -- To get around this problem we call Remove_Side_Effects right
5563 -- away if either bounds of R are a Constraint_Error.
5566 L : constant Node_Id := Low_Bound (R);
5567 H : constant Node_Id := High_Bound (R);
5570 if Nkind (L) = N_Raise_Constraint_Error then
5571 Remove_Side_Effects (L);
5574 if Nkind (H) = N_Raise_Constraint_Error then
5575 Remove_Side_Effects (H);
5579 Check_Unset_Reference (Low_Bound (R));
5580 Check_Unset_Reference (High_Bound (R));
5583 end Resolve_Discrete_Subtype_Indication;
5585 -------------------------
5586 -- Resolve_Entity_Name --
5587 -------------------------
5589 -- Used to resolve identifiers and expanded names
5591 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5592 E : constant Entity_Id := Entity (N);
5595 -- If garbage from errors, set to Any_Type and return
5597 if No (E) and then Total_Errors_Detected /= 0 then
5598 Set_Etype (N, Any_Type);
5602 -- Replace named numbers by corresponding literals. Note that this is
5603 -- the one case where Resolve_Entity_Name must reset the Etype, since
5604 -- it is currently marked as universal.
5606 if Ekind (E) = E_Named_Integer then
5608 Eval_Named_Integer (N);
5610 elsif Ekind (E) = E_Named_Real then
5612 Eval_Named_Real (N);
5614 -- Allow use of subtype only if it is a concurrent type where we are
5615 -- currently inside the body. This will eventually be expanded into a
5616 -- call to Self (for tasks) or _object (for protected objects). Any
5617 -- other use of a subtype is invalid.
5619 elsif Is_Type (E) then
5620 if Is_Concurrent_Type (E)
5621 and then In_Open_Scopes (E)
5626 ("invalid use of subtype mark in expression or call", N);
5629 -- Check discriminant use if entity is discriminant in current scope,
5630 -- i.e. discriminant of record or concurrent type currently being
5631 -- analyzed. Uses in corresponding body are unrestricted.
5633 elsif Ekind (E) = E_Discriminant
5634 and then Scope (E) = Current_Scope
5635 and then not Has_Completion (Current_Scope)
5637 Check_Discriminant_Use (N);
5639 -- A parameterless generic function cannot appear in a context that
5640 -- requires resolution.
5642 elsif Ekind (E) = E_Generic_Function then
5643 Error_Msg_N ("illegal use of generic function", N);
5645 elsif Ekind (E) = E_Out_Parameter
5646 and then Ada_Version = Ada_83
5647 and then (Nkind (Parent (N)) in N_Op
5648 or else (Nkind (Parent (N)) = N_Assignment_Statement
5649 and then N = Expression (Parent (N)))
5650 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5652 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5654 -- In all other cases, just do the possible static evaluation
5657 -- A deferred constant that appears in an expression must have a
5658 -- completion, unless it has been removed by in-place expansion of
5661 if Ekind (E) = E_Constant
5662 and then Comes_From_Source (E)
5663 and then No (Constant_Value (E))
5664 and then Is_Frozen (Etype (E))
5665 and then not In_Spec_Expression
5666 and then not Is_Imported (E)
5669 if No_Initialization (Parent (E))
5670 or else (Present (Full_View (E))
5671 and then No_Initialization (Parent (Full_View (E))))
5676 "deferred constant is frozen before completion", N);
5680 Eval_Entity_Name (N);
5682 end Resolve_Entity_Name;
5688 procedure Resolve_Entry (Entry_Name : Node_Id) is
5689 Loc : constant Source_Ptr := Sloc (Entry_Name);
5697 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5698 -- If the bounds of the entry family being called depend on task
5699 -- discriminants, build a new index subtype where a discriminant is
5700 -- replaced with the value of the discriminant of the target task.
5701 -- The target task is the prefix of the entry name in the call.
5703 -----------------------
5704 -- Actual_Index_Type --
5705 -----------------------
5707 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5708 Typ : constant Entity_Id := Entry_Index_Type (E);
5709 Tsk : constant Entity_Id := Scope (E);
5710 Lo : constant Node_Id := Type_Low_Bound (Typ);
5711 Hi : constant Node_Id := Type_High_Bound (Typ);
5714 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5715 -- If the bound is given by a discriminant, replace with a reference
5716 -- to the discriminant of the same name in the target task. If the
5717 -- entry name is the target of a requeue statement and the entry is
5718 -- in the current protected object, the bound to be used is the
5719 -- discriminal of the object (see apply_range_checks for details of
5720 -- the transformation).
5722 -----------------------------
5723 -- Actual_Discriminant_Ref --
5724 -----------------------------
5726 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5727 Typ : constant Entity_Id := Etype (Bound);
5731 Remove_Side_Effects (Bound);
5733 if not Is_Entity_Name (Bound)
5734 or else Ekind (Entity (Bound)) /= E_Discriminant
5738 elsif Is_Protected_Type (Tsk)
5739 and then In_Open_Scopes (Tsk)
5740 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5742 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5746 Make_Selected_Component (Loc,
5747 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5748 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5753 end Actual_Discriminant_Ref;
5755 -- Start of processing for Actual_Index_Type
5758 if not Has_Discriminants (Tsk)
5759 or else (not Is_Entity_Name (Lo)
5761 not Is_Entity_Name (Hi))
5763 return Entry_Index_Type (E);
5766 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5767 Set_Etype (New_T, Base_Type (Typ));
5768 Set_Size_Info (New_T, Typ);
5769 Set_RM_Size (New_T, RM_Size (Typ));
5770 Set_Scalar_Range (New_T,
5771 Make_Range (Sloc (Entry_Name),
5772 Low_Bound => Actual_Discriminant_Ref (Lo),
5773 High_Bound => Actual_Discriminant_Ref (Hi)));
5777 end Actual_Index_Type;
5779 -- Start of processing of Resolve_Entry
5782 -- Find name of entry being called, and resolve prefix of name
5783 -- with its own type. The prefix can be overloaded, and the name
5784 -- and signature of the entry must be taken into account.
5786 if Nkind (Entry_Name) = N_Indexed_Component then
5788 -- Case of dealing with entry family within the current tasks
5790 E_Name := Prefix (Entry_Name);
5793 E_Name := Entry_Name;
5796 if Is_Entity_Name (E_Name) then
5798 -- Entry call to an entry (or entry family) in the current task. This
5799 -- is legal even though the task will deadlock. Rewrite as call to
5802 -- This can also be a call to an entry in an enclosing task. If this
5803 -- is a single task, we have to retrieve its name, because the scope
5804 -- of the entry is the task type, not the object. If the enclosing
5805 -- task is a task type, the identity of the task is given by its own
5808 -- Finally this can be a requeue on an entry of the same task or
5809 -- protected object.
5811 S := Scope (Entity (E_Name));
5813 for J in reverse 0 .. Scope_Stack.Last loop
5814 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5815 and then not Comes_From_Source (S)
5817 -- S is an enclosing task or protected object. The concurrent
5818 -- declaration has been converted into a type declaration, and
5819 -- the object itself has an object declaration that follows
5820 -- the type in the same declarative part.
5822 Tsk := Next_Entity (S);
5823 while Etype (Tsk) /= S loop
5830 elsif S = Scope_Stack.Table (J).Entity then
5832 -- Call to current task. Will be transformed into call to Self
5840 Make_Selected_Component (Loc,
5841 Prefix => New_Occurrence_Of (S, Loc),
5843 New_Occurrence_Of (Entity (E_Name), Loc));
5844 Rewrite (E_Name, New_N);
5847 elsif Nkind (Entry_Name) = N_Selected_Component
5848 and then Is_Overloaded (Prefix (Entry_Name))
5850 -- Use the entry name (which must be unique at this point) to find
5851 -- the prefix that returns the corresponding task type or protected
5855 Pref : constant Node_Id := Prefix (Entry_Name);
5856 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5861 Get_First_Interp (Pref, I, It);
5862 while Present (It.Typ) loop
5863 if Scope (Ent) = It.Typ then
5864 Set_Etype (Pref, It.Typ);
5868 Get_Next_Interp (I, It);
5873 if Nkind (Entry_Name) = N_Selected_Component then
5874 Resolve (Prefix (Entry_Name));
5876 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5877 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5878 Resolve (Prefix (Prefix (Entry_Name)));
5879 Index := First (Expressions (Entry_Name));
5880 Resolve (Index, Entry_Index_Type (Nam));
5882 -- Up to this point the expression could have been the actual in a
5883 -- simple entry call, and be given by a named association.
5885 if Nkind (Index) = N_Parameter_Association then
5886 Error_Msg_N ("expect expression for entry index", Index);
5888 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5893 ------------------------
5894 -- Resolve_Entry_Call --
5895 ------------------------
5897 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5898 Entry_Name : constant Node_Id := Name (N);
5899 Loc : constant Source_Ptr := Sloc (Entry_Name);
5901 First_Named : Node_Id;
5908 -- We kill all checks here, because it does not seem worth the effort to
5909 -- do anything better, an entry call is a big operation.
5913 -- Processing of the name is similar for entry calls and protected
5914 -- operation calls. Once the entity is determined, we can complete
5915 -- the resolution of the actuals.
5917 -- The selector may be overloaded, in the case of a protected object
5918 -- with overloaded functions. The type of the context is used for
5921 if Nkind (Entry_Name) = N_Selected_Component
5922 and then Is_Overloaded (Selector_Name (Entry_Name))
5923 and then Typ /= Standard_Void_Type
5930 Get_First_Interp (Selector_Name (Entry_Name), I, It);
5931 while Present (It.Typ) loop
5932 if Covers (Typ, It.Typ) then
5933 Set_Entity (Selector_Name (Entry_Name), It.Nam);
5934 Set_Etype (Entry_Name, It.Typ);
5936 Generate_Reference (It.Typ, N, ' ');
5939 Get_Next_Interp (I, It);
5944 Resolve_Entry (Entry_Name);
5946 if Nkind (Entry_Name) = N_Selected_Component then
5948 -- Simple entry call
5950 Nam := Entity (Selector_Name (Entry_Name));
5951 Obj := Prefix (Entry_Name);
5952 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
5954 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5956 -- Call to member of entry family
5958 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5959 Obj := Prefix (Prefix (Entry_Name));
5960 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
5963 -- We cannot in general check the maximum depth of protected entry
5964 -- calls at compile time. But we can tell that any protected entry
5965 -- call at all violates a specified nesting depth of zero.
5967 if Is_Protected_Type (Scope (Nam)) then
5968 Check_Restriction (Max_Entry_Queue_Length, N);
5971 -- Use context type to disambiguate a protected function that can be
5972 -- called without actuals and that returns an array type, and where
5973 -- the argument list may be an indexing of the returned value.
5975 if Ekind (Nam) = E_Function
5976 and then Needs_No_Actuals (Nam)
5977 and then Present (Parameter_Associations (N))
5979 ((Is_Array_Type (Etype (Nam))
5980 and then Covers (Typ, Component_Type (Etype (Nam))))
5982 or else (Is_Access_Type (Etype (Nam))
5983 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5984 and then Covers (Typ,
5985 Component_Type (Designated_Type (Etype (Nam))))))
5988 Index_Node : Node_Id;
5992 Make_Indexed_Component (Loc,
5994 Make_Function_Call (Loc,
5995 Name => Relocate_Node (Entry_Name)),
5996 Expressions => Parameter_Associations (N));
5998 -- Since we are correcting a node classification error made by
5999 -- the parser, we call Replace rather than Rewrite.
6001 Replace (N, Index_Node);
6002 Set_Etype (Prefix (N), Etype (Nam));
6004 Resolve_Indexed_Component (N, Typ);
6009 -- The operation name may have been overloaded. Order the actuals
6010 -- according to the formals of the resolved entity, and set the
6011 -- return type to that of the operation.
6014 Normalize_Actuals (N, Nam, False, Norm_OK);
6015 pragma Assert (Norm_OK);
6016 Set_Etype (N, Etype (Nam));
6019 Resolve_Actuals (N, Nam);
6020 Generate_Reference (Nam, Entry_Name);
6022 if Ekind (Nam) = E_Entry
6023 or else Ekind (Nam) = E_Entry_Family
6025 Check_Potentially_Blocking_Operation (N);
6028 -- Verify that a procedure call cannot masquerade as an entry
6029 -- call where an entry call is expected.
6031 if Ekind (Nam) = E_Procedure then
6032 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6033 and then N = Entry_Call_Statement (Parent (N))
6035 Error_Msg_N ("entry call required in select statement", N);
6037 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6038 and then N = Triggering_Statement (Parent (N))
6040 Error_Msg_N ("triggering statement cannot be procedure call", N);
6042 elsif Ekind (Scope (Nam)) = E_Task_Type
6043 and then not In_Open_Scopes (Scope (Nam))
6045 Error_Msg_N ("task has no entry with this name", Entry_Name);
6049 -- After resolution, entry calls and protected procedure calls are
6050 -- changed into entry calls, for expansion. The structure of the node
6051 -- does not change, so it can safely be done in place. Protected
6052 -- function calls must keep their structure because they are
6055 if Ekind (Nam) /= E_Function then
6057 -- A protected operation that is not a function may modify the
6058 -- corresponding object, and cannot apply to a constant. If this
6059 -- is an internal call, the prefix is the type itself.
6061 if Is_Protected_Type (Scope (Nam))
6062 and then not Is_Variable (Obj)
6063 and then (not Is_Entity_Name (Obj)
6064 or else not Is_Type (Entity (Obj)))
6067 ("prefix of protected procedure or entry call must be variable",
6071 Actuals := Parameter_Associations (N);
6072 First_Named := First_Named_Actual (N);
6075 Make_Entry_Call_Statement (Loc,
6077 Parameter_Associations => Actuals));
6079 Set_First_Named_Actual (N, First_Named);
6080 Set_Analyzed (N, True);
6082 -- Protected functions can return on the secondary stack, in which
6083 -- case we must trigger the transient scope mechanism.
6085 elsif Expander_Active
6086 and then Requires_Transient_Scope (Etype (Nam))
6088 Establish_Transient_Scope (N, Sec_Stack => True);
6090 end Resolve_Entry_Call;
6092 -------------------------
6093 -- Resolve_Equality_Op --
6094 -------------------------
6096 -- Both arguments must have the same type, and the boolean context does
6097 -- not participate in the resolution. The first pass verifies that the
6098 -- interpretation is not ambiguous, and the type of the left argument is
6099 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6100 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6101 -- though they carry a single (universal) type. Diagnose this case here.
6103 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6104 L : constant Node_Id := Left_Opnd (N);
6105 R : constant Node_Id := Right_Opnd (N);
6106 T : Entity_Id := Find_Unique_Type (L, R);
6108 function Find_Unique_Access_Type return Entity_Id;
6109 -- In the case of allocators, make a last-ditch attempt to find a single
6110 -- access type with the right designated type. This is semantically
6111 -- dubious, and of no interest to any real code, but c48008a makes it
6114 -----------------------------
6115 -- Find_Unique_Access_Type --
6116 -----------------------------
6118 function Find_Unique_Access_Type return Entity_Id is
6124 if Ekind (Etype (R)) = E_Allocator_Type then
6125 Acc := Designated_Type (Etype (R));
6126 elsif Ekind (Etype (L)) = E_Allocator_Type then
6127 Acc := Designated_Type (Etype (L));
6133 while S /= Standard_Standard loop
6134 E := First_Entity (S);
6135 while Present (E) loop
6137 and then Is_Access_Type (E)
6138 and then Ekind (E) /= E_Allocator_Type
6139 and then Designated_Type (E) = Base_Type (Acc)
6151 end Find_Unique_Access_Type;
6153 -- Start of processing for Resolve_Equality_Op
6156 Set_Etype (N, Base_Type (Typ));
6157 Generate_Reference (T, N, ' ');
6159 if T = Any_Fixed then
6160 T := Unique_Fixed_Point_Type (L);
6163 if T /= Any_Type then
6165 or else T = Any_Composite
6166 or else T = Any_Character
6168 if T = Any_Character then
6169 Ambiguous_Character (L);
6171 Error_Msg_N ("ambiguous operands for equality", N);
6174 Set_Etype (N, Any_Type);
6177 elsif T = Any_Access
6178 or else Ekind (T) = E_Allocator_Type
6179 or else Ekind (T) = E_Access_Attribute_Type
6181 T := Find_Unique_Access_Type;
6184 Error_Msg_N ("ambiguous operands for equality", N);
6185 Set_Etype (N, Any_Type);
6193 -- If the unique type is a class-wide type then it will be expanded
6194 -- into a dispatching call to the predefined primitive. Therefore we
6195 -- check here for potential violation of such restriction.
6197 if Is_Class_Wide_Type (T) then
6198 Check_Restriction (No_Dispatching_Calls, N);
6201 if Warn_On_Redundant_Constructs
6202 and then Comes_From_Source (N)
6203 and then Is_Entity_Name (R)
6204 and then Entity (R) = Standard_True
6205 and then Comes_From_Source (R)
6207 Error_Msg_N ("?comparison with True is redundant!", R);
6210 Check_Unset_Reference (L);
6211 Check_Unset_Reference (R);
6212 Generate_Operator_Reference (N, T);
6213 Check_Low_Bound_Tested (N);
6215 -- If this is an inequality, it may be the implicit inequality
6216 -- created for a user-defined operation, in which case the corres-
6217 -- ponding equality operation is not intrinsic, and the operation
6218 -- cannot be constant-folded. Else fold.
6220 if Nkind (N) = N_Op_Eq
6221 or else Comes_From_Source (Entity (N))
6222 or else Ekind (Entity (N)) = E_Operator
6223 or else Is_Intrinsic_Subprogram
6224 (Corresponding_Equality (Entity (N)))
6226 Eval_Relational_Op (N);
6228 elsif Nkind (N) = N_Op_Ne
6229 and then Is_Abstract_Subprogram (Entity (N))
6231 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6234 -- Ada 2005: If one operand is an anonymous access type, convert the
6235 -- other operand to it, to ensure that the underlying types match in
6236 -- the back-end. Same for access_to_subprogram, and the conversion
6237 -- verifies that the types are subtype conformant.
6239 -- We apply the same conversion in the case one of the operands is a
6240 -- private subtype of the type of the other.
6242 -- Why the Expander_Active test here ???
6246 (Ekind (T) = E_Anonymous_Access_Type
6247 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6248 or else Is_Private_Type (T))
6250 if Etype (L) /= T then
6252 Make_Unchecked_Type_Conversion (Sloc (L),
6253 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6254 Expression => Relocate_Node (L)));
6255 Analyze_And_Resolve (L, T);
6258 if (Etype (R)) /= T then
6260 Make_Unchecked_Type_Conversion (Sloc (R),
6261 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6262 Expression => Relocate_Node (R)));
6263 Analyze_And_Resolve (R, T);
6267 end Resolve_Equality_Op;
6269 ----------------------------------
6270 -- Resolve_Explicit_Dereference --
6271 ----------------------------------
6273 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6274 Loc : constant Source_Ptr := Sloc (N);
6276 P : constant Node_Id := Prefix (N);
6281 Check_Fully_Declared_Prefix (Typ, P);
6283 if Is_Overloaded (P) then
6285 -- Use the context type to select the prefix that has the correct
6288 Get_First_Interp (P, I, It);
6289 while Present (It.Typ) loop
6290 exit when Is_Access_Type (It.Typ)
6291 and then Covers (Typ, Designated_Type (It.Typ));
6292 Get_Next_Interp (I, It);
6295 if Present (It.Typ) then
6296 Resolve (P, It.Typ);
6298 -- If no interpretation covers the designated type of the prefix,
6299 -- this is the pathological case where not all implementations of
6300 -- the prefix allow the interpretation of the node as a call. Now
6301 -- that the expected type is known, Remove other interpretations
6302 -- from prefix, rewrite it as a call, and resolve again, so that
6303 -- the proper call node is generated.
6305 Get_First_Interp (P, I, It);
6306 while Present (It.Typ) loop
6307 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6311 Get_Next_Interp (I, It);
6315 Make_Function_Call (Loc,
6317 Make_Explicit_Dereference (Loc,
6319 Parameter_Associations => New_List);
6321 Save_Interps (N, New_N);
6323 Analyze_And_Resolve (N, Typ);
6327 Set_Etype (N, Designated_Type (It.Typ));
6333 if Is_Access_Type (Etype (P)) then
6334 Apply_Access_Check (N);
6337 -- If the designated type is a packed unconstrained array type, and the
6338 -- explicit dereference is not in the context of an attribute reference,
6339 -- then we must compute and set the actual subtype, since it is needed
6340 -- by Gigi. The reason we exclude the attribute case is that this is
6341 -- handled fine by Gigi, and in fact we use such attributes to build the
6342 -- actual subtype. We also exclude generated code (which builds actual
6343 -- subtypes directly if they are needed).
6345 if Is_Array_Type (Etype (N))
6346 and then Is_Packed (Etype (N))
6347 and then not Is_Constrained (Etype (N))
6348 and then Nkind (Parent (N)) /= N_Attribute_Reference
6349 and then Comes_From_Source (N)
6351 Set_Etype (N, Get_Actual_Subtype (N));
6354 -- Note: there is no Eval processing required for an explicit deference,
6355 -- because the type is known to be an allocators, and allocator
6356 -- expressions can never be static.
6358 end Resolve_Explicit_Dereference;
6360 -------------------------------
6361 -- Resolve_Indexed_Component --
6362 -------------------------------
6364 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6365 Name : constant Node_Id := Prefix (N);
6367 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6371 if Is_Overloaded (Name) then
6373 -- Use the context type to select the prefix that yields the correct
6379 I1 : Interp_Index := 0;
6380 P : constant Node_Id := Prefix (N);
6381 Found : Boolean := False;
6384 Get_First_Interp (P, I, It);
6385 while Present (It.Typ) loop
6386 if (Is_Array_Type (It.Typ)
6387 and then Covers (Typ, Component_Type (It.Typ)))
6388 or else (Is_Access_Type (It.Typ)
6389 and then Is_Array_Type (Designated_Type (It.Typ))
6391 (Typ, Component_Type (Designated_Type (It.Typ))))
6394 It := Disambiguate (P, I1, I, Any_Type);
6396 if It = No_Interp then
6397 Error_Msg_N ("ambiguous prefix for indexing", N);
6403 Array_Type := It.Typ;
6409 Array_Type := It.Typ;
6414 Get_Next_Interp (I, It);
6419 Array_Type := Etype (Name);
6422 Resolve (Name, Array_Type);
6423 Array_Type := Get_Actual_Subtype_If_Available (Name);
6425 -- If prefix is access type, dereference to get real array type.
6426 -- Note: we do not apply an access check because the expander always
6427 -- introduces an explicit dereference, and the check will happen there.
6429 if Is_Access_Type (Array_Type) then
6430 Array_Type := Designated_Type (Array_Type);
6433 -- If name was overloaded, set component type correctly now
6434 -- If a misplaced call to an entry family (which has no index types)
6435 -- return. Error will be diagnosed from calling context.
6437 if Is_Array_Type (Array_Type) then
6438 Set_Etype (N, Component_Type (Array_Type));
6443 Index := First_Index (Array_Type);
6444 Expr := First (Expressions (N));
6446 -- The prefix may have resolved to a string literal, in which case its
6447 -- etype has a special representation. This is only possible currently
6448 -- if the prefix is a static concatenation, written in functional
6451 if Ekind (Array_Type) = E_String_Literal_Subtype then
6452 Resolve (Expr, Standard_Positive);
6455 while Present (Index) and Present (Expr) loop
6456 Resolve (Expr, Etype (Index));
6457 Check_Unset_Reference (Expr);
6459 if Is_Scalar_Type (Etype (Expr)) then
6460 Apply_Scalar_Range_Check (Expr, Etype (Index));
6462 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6470 -- Do not generate the warning on suspicious index if we are analyzing
6471 -- package Ada.Tags; otherwise we will report the warning with the
6472 -- Prims_Ptr field of the dispatch table.
6474 if Scope (Etype (Prefix (N))) = Standard_Standard
6476 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6479 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6480 Eval_Indexed_Component (N);
6482 end Resolve_Indexed_Component;
6484 -----------------------------
6485 -- Resolve_Integer_Literal --
6486 -----------------------------
6488 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6491 Eval_Integer_Literal (N);
6492 end Resolve_Integer_Literal;
6494 --------------------------------
6495 -- Resolve_Intrinsic_Operator --
6496 --------------------------------
6498 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6499 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6506 while Scope (Op) /= Standard_Standard loop
6508 pragma Assert (Present (Op));
6512 Set_Is_Overloaded (N, False);
6514 -- If the operand type is private, rewrite with suitable conversions on
6515 -- the operands and the result, to expose the proper underlying numeric
6518 if Is_Private_Type (Typ) then
6519 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6521 if Nkind (N) = N_Op_Expon then
6522 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6524 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6527 Save_Interps (Left_Opnd (N), Expression (Arg1));
6528 Save_Interps (Right_Opnd (N), Expression (Arg2));
6530 Set_Left_Opnd (N, Arg1);
6531 Set_Right_Opnd (N, Arg2);
6533 Set_Etype (N, Btyp);
6534 Rewrite (N, Unchecked_Convert_To (Typ, N));
6537 elsif Typ /= Etype (Left_Opnd (N))
6538 or else Typ /= Etype (Right_Opnd (N))
6540 -- Add explicit conversion where needed, and save interpretations in
6541 -- case operands are overloaded.
6543 Arg1 := Convert_To (Typ, Left_Opnd (N));
6544 Arg2 := Convert_To (Typ, Right_Opnd (N));
6546 if Nkind (Arg1) = N_Type_Conversion then
6547 Save_Interps (Left_Opnd (N), Expression (Arg1));
6549 Save_Interps (Left_Opnd (N), Arg1);
6552 if Nkind (Arg2) = N_Type_Conversion then
6553 Save_Interps (Right_Opnd (N), Expression (Arg2));
6555 Save_Interps (Right_Opnd (N), Arg2);
6558 Rewrite (Left_Opnd (N), Arg1);
6559 Rewrite (Right_Opnd (N), Arg2);
6562 Resolve_Arithmetic_Op (N, Typ);
6565 Resolve_Arithmetic_Op (N, Typ);
6567 end Resolve_Intrinsic_Operator;
6569 --------------------------------------
6570 -- Resolve_Intrinsic_Unary_Operator --
6571 --------------------------------------
6573 procedure Resolve_Intrinsic_Unary_Operator
6577 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6583 while Scope (Op) /= Standard_Standard loop
6585 pragma Assert (Present (Op));
6590 if Is_Private_Type (Typ) then
6591 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6592 Save_Interps (Right_Opnd (N), Expression (Arg2));
6594 Set_Right_Opnd (N, Arg2);
6596 Set_Etype (N, Btyp);
6597 Rewrite (N, Unchecked_Convert_To (Typ, N));
6601 Resolve_Unary_Op (N, Typ);
6603 end Resolve_Intrinsic_Unary_Operator;
6605 ------------------------
6606 -- Resolve_Logical_Op --
6607 ------------------------
6609 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6611 N_Opr : constant Node_Kind := Nkind (N);
6614 -- Predefined operations on scalar types yield the base type. On the
6615 -- other hand, logical operations on arrays yield the type of the
6616 -- arguments (and the context).
6618 if Is_Array_Type (Typ) then
6621 B_Typ := Base_Type (Typ);
6624 -- The following test is required because the operands of the operation
6625 -- may be literals, in which case the resulting type appears to be
6626 -- compatible with a signed integer type, when in fact it is compatible
6627 -- only with modular types. If the context itself is universal, the
6628 -- operation is illegal.
6630 if not Valid_Boolean_Arg (Typ) then
6631 Error_Msg_N ("invalid context for logical operation", N);
6632 Set_Etype (N, Any_Type);
6635 elsif Typ = Any_Modular then
6637 ("no modular type available in this context", N);
6638 Set_Etype (N, Any_Type);
6640 elsif Is_Modular_Integer_Type (Typ)
6641 and then Etype (Left_Opnd (N)) = Universal_Integer
6642 and then Etype (Right_Opnd (N)) = Universal_Integer
6644 Check_For_Visible_Operator (N, B_Typ);
6647 Resolve (Left_Opnd (N), B_Typ);
6648 Resolve (Right_Opnd (N), B_Typ);
6650 Check_Unset_Reference (Left_Opnd (N));
6651 Check_Unset_Reference (Right_Opnd (N));
6653 Set_Etype (N, B_Typ);
6654 Generate_Operator_Reference (N, B_Typ);
6655 Eval_Logical_Op (N);
6657 -- Check for violation of restriction No_Direct_Boolean_Operators
6658 -- if the operator was not eliminated by the Eval_Logical_Op call.
6660 if Nkind (N) = N_Opr
6661 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
6663 Check_Restriction (No_Direct_Boolean_Operators, N);
6665 end Resolve_Logical_Op;
6667 ---------------------------
6668 -- Resolve_Membership_Op --
6669 ---------------------------
6671 -- The context can only be a boolean type, and does not determine
6672 -- the arguments. Arguments should be unambiguous, but the preference
6673 -- rule for universal types applies.
6675 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6676 pragma Warnings (Off, Typ);
6678 L : constant Node_Id := Left_Opnd (N);
6679 R : constant Node_Id := Right_Opnd (N);
6683 if L = Error or else R = Error then
6687 if not Is_Overloaded (R)
6689 (Etype (R) = Universal_Integer or else
6690 Etype (R) = Universal_Real)
6691 and then Is_Overloaded (L)
6695 -- Ada 2005 (AI-251): Support the following case:
6697 -- type I is interface;
6698 -- type T is tagged ...
6700 -- function Test (O : I'Class) is
6702 -- return O in T'Class.
6705 -- In this case we have nothing else to do. The membership test will be
6706 -- done at run-time.
6708 elsif Ada_Version >= Ada_05
6709 and then Is_Class_Wide_Type (Etype (L))
6710 and then Is_Interface (Etype (L))
6711 and then Is_Class_Wide_Type (Etype (R))
6712 and then not Is_Interface (Etype (R))
6717 T := Intersect_Types (L, R);
6721 Check_Unset_Reference (L);
6723 if Nkind (R) = N_Range
6724 and then not Is_Scalar_Type (T)
6726 Error_Msg_N ("scalar type required for range", R);
6729 if Is_Entity_Name (R) then
6730 Freeze_Expression (R);
6733 Check_Unset_Reference (R);
6736 Eval_Membership_Op (N);
6737 end Resolve_Membership_Op;
6743 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6744 Loc : constant Source_Ptr := Sloc (N);
6747 -- Handle restriction against anonymous null access values This
6748 -- restriction can be turned off using -gnatdj.
6750 -- Ada 2005 (AI-231): Remove restriction
6752 if Ada_Version < Ada_05
6753 and then not Debug_Flag_J
6754 and then Ekind (Typ) = E_Anonymous_Access_Type
6755 and then Comes_From_Source (N)
6757 -- In the common case of a call which uses an explicitly null value
6758 -- for an access parameter, give specialized error message.
6760 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6764 ("null is not allowed as argument for an access parameter", N);
6766 -- Standard message for all other cases (are there any?)
6770 ("null cannot be of an anonymous access type", N);
6774 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6775 -- assignment to a null-excluding object
6777 if Ada_Version >= Ada_05
6778 and then Can_Never_Be_Null (Typ)
6779 and then Nkind (Parent (N)) = N_Assignment_Statement
6781 if not Inside_Init_Proc then
6783 (Compile_Time_Constraint_Error (N,
6784 "(Ada 2005) null not allowed in null-excluding objects?"),
6785 Make_Raise_Constraint_Error (Loc,
6786 Reason => CE_Access_Check_Failed));
6789 Make_Raise_Constraint_Error (Loc,
6790 Reason => CE_Access_Check_Failed));
6794 -- In a distributed context, null for a remote access to subprogram may
6795 -- need to be replaced with a special record aggregate. In this case,
6796 -- return after having done the transformation.
6798 if (Ekind (Typ) = E_Record_Type
6799 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6800 and then Remote_AST_Null_Value (N, Typ)
6805 -- The null literal takes its type from the context
6810 -----------------------
6811 -- Resolve_Op_Concat --
6812 -----------------------
6814 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6816 -- We wish to avoid deep recursion, because concatenations are often
6817 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6818 -- operands nonrecursively until we find something that is not a simple
6819 -- concatenation (A in this case). We resolve that, and then walk back
6820 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6821 -- to do the rest of the work at each level. The Parent pointers allow
6822 -- us to avoid recursion, and thus avoid running out of memory. See also
6823 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6829 -- The following code is equivalent to:
6831 -- Resolve_Op_Concat_First (NN, Typ);
6832 -- Resolve_Op_Concat_Arg (N, ...);
6833 -- Resolve_Op_Concat_Rest (N, Typ);
6835 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6836 -- operand is a concatenation.
6838 -- Walk down left operands
6841 Resolve_Op_Concat_First (NN, Typ);
6842 Op1 := Left_Opnd (NN);
6843 exit when not (Nkind (Op1) = N_Op_Concat
6844 and then not Is_Array_Type (Component_Type (Typ))
6845 and then Entity (Op1) = Entity (NN));
6849 -- Now (given the above example) NN is A&B and Op1 is A
6851 -- First resolve Op1 ...
6853 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6855 -- ... then walk NN back up until we reach N (where we started), calling
6856 -- Resolve_Op_Concat_Rest along the way.
6859 Resolve_Op_Concat_Rest (NN, Typ);
6863 end Resolve_Op_Concat;
6865 ---------------------------
6866 -- Resolve_Op_Concat_Arg --
6867 ---------------------------
6869 procedure Resolve_Op_Concat_Arg
6875 Btyp : constant Entity_Id := Base_Type (Typ);
6880 or else (not Is_Overloaded (Arg)
6881 and then Etype (Arg) /= Any_Composite
6882 and then Covers (Component_Type (Typ), Etype (Arg)))
6884 Resolve (Arg, Component_Type (Typ));
6886 Resolve (Arg, Btyp);
6889 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6890 if Nkind (Arg) = N_Aggregate
6891 and then Is_Composite_Type (Component_Type (Typ))
6893 if Is_Private_Type (Component_Type (Typ)) then
6894 Resolve (Arg, Btyp);
6896 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6897 Set_Etype (Arg, Any_Type);
6901 if Is_Overloaded (Arg)
6902 and then Has_Compatible_Type (Arg, Typ)
6903 and then Etype (Arg) /= Any_Type
6911 Get_First_Interp (Arg, I, It);
6913 Get_Next_Interp (I, It);
6915 -- Special-case the error message when the overloading is
6916 -- caused by a function that yields an array and can be
6917 -- called without parameters.
6919 if It.Nam = Func then
6920 Error_Msg_Sloc := Sloc (Func);
6921 Error_Msg_N ("ambiguous call to function#", Arg);
6923 ("\\interpretation as call yields&", Arg, Typ);
6925 ("\\interpretation as indexing of call yields&",
6926 Arg, Component_Type (Typ));
6930 ("ambiguous operand for concatenation!", Arg);
6931 Get_First_Interp (Arg, I, It);
6932 while Present (It.Nam) loop
6933 Error_Msg_Sloc := Sloc (It.Nam);
6935 if Base_Type (It.Typ) = Base_Type (Typ)
6936 or else Base_Type (It.Typ) =
6937 Base_Type (Component_Type (Typ))
6939 Error_Msg_N ("\\possible interpretation#", Arg);
6942 Get_Next_Interp (I, It);
6948 Resolve (Arg, Component_Type (Typ));
6950 if Nkind (Arg) = N_String_Literal then
6951 Set_Etype (Arg, Component_Type (Typ));
6954 if Arg = Left_Opnd (N) then
6955 Set_Is_Component_Left_Opnd (N);
6957 Set_Is_Component_Right_Opnd (N);
6962 Resolve (Arg, Btyp);
6965 Check_Unset_Reference (Arg);
6966 end Resolve_Op_Concat_Arg;
6968 -----------------------------
6969 -- Resolve_Op_Concat_First --
6970 -----------------------------
6972 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
6973 Btyp : constant Entity_Id := Base_Type (Typ);
6974 Op1 : constant Node_Id := Left_Opnd (N);
6975 Op2 : constant Node_Id := Right_Opnd (N);
6978 -- The parser folds an enormous sequence of concatenations of string
6979 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
6980 -- in the right. If the expression resolves to a predefined "&"
6981 -- operator, all is well. Otherwise, the parser's folding is wrong, so
6982 -- we give an error. See P_Simple_Expression in Par.Ch4.
6984 if Nkind (Op2) = N_String_Literal
6985 and then Is_Folded_In_Parser (Op2)
6986 and then Ekind (Entity (N)) = E_Function
6988 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
6989 and then String_Length (Strval (Op1)) = 0);
6990 Error_Msg_N ("too many user-defined concatenations", N);
6994 Set_Etype (N, Btyp);
6996 if Is_Limited_Composite (Btyp) then
6997 Error_Msg_N ("concatenation not available for limited array", N);
6998 Explain_Limited_Type (Btyp, N);
7000 end Resolve_Op_Concat_First;
7002 ----------------------------
7003 -- Resolve_Op_Concat_Rest --
7004 ----------------------------
7006 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7007 Op1 : constant Node_Id := Left_Opnd (N);
7008 Op2 : constant Node_Id := Right_Opnd (N);
7011 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7013 Generate_Operator_Reference (N, Typ);
7015 if Is_String_Type (Typ) then
7016 Eval_Concatenation (N);
7019 -- If this is not a static concatenation, but the result is a string
7020 -- type (and not an array of strings) ensure that static string operands
7021 -- have their subtypes properly constructed.
7023 if Nkind (N) /= N_String_Literal
7024 and then Is_Character_Type (Component_Type (Typ))
7026 Set_String_Literal_Subtype (Op1, Typ);
7027 Set_String_Literal_Subtype (Op2, Typ);
7029 end Resolve_Op_Concat_Rest;
7031 ----------------------
7032 -- Resolve_Op_Expon --
7033 ----------------------
7035 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7036 B_Typ : constant Entity_Id := Base_Type (Typ);
7039 -- Catch attempts to do fixed-point exponentiation with universal
7040 -- operands, which is a case where the illegality is not caught during
7041 -- normal operator analysis.
7043 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7044 Error_Msg_N ("exponentiation not available for fixed point", N);
7048 if Comes_From_Source (N)
7049 and then Ekind (Entity (N)) = E_Function
7050 and then Is_Imported (Entity (N))
7051 and then Is_Intrinsic_Subprogram (Entity (N))
7053 Resolve_Intrinsic_Operator (N, Typ);
7057 if Etype (Left_Opnd (N)) = Universal_Integer
7058 or else Etype (Left_Opnd (N)) = Universal_Real
7060 Check_For_Visible_Operator (N, B_Typ);
7063 -- We do the resolution using the base type, because intermediate values
7064 -- in expressions always are of the base type, not a subtype of it.
7066 Resolve (Left_Opnd (N), B_Typ);
7067 Resolve (Right_Opnd (N), Standard_Integer);
7069 Check_Unset_Reference (Left_Opnd (N));
7070 Check_Unset_Reference (Right_Opnd (N));
7072 Set_Etype (N, B_Typ);
7073 Generate_Operator_Reference (N, B_Typ);
7076 -- Set overflow checking bit. Much cleverer code needed here eventually
7077 -- and perhaps the Resolve routines should be separated for the various
7078 -- arithmetic operations, since they will need different processing. ???
7080 if Nkind (N) in N_Op then
7081 if not Overflow_Checks_Suppressed (Etype (N)) then
7082 Enable_Overflow_Check (N);
7085 end Resolve_Op_Expon;
7087 --------------------
7088 -- Resolve_Op_Not --
7089 --------------------
7091 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7094 function Parent_Is_Boolean return Boolean;
7095 -- This function determines if the parent node is a boolean operator
7096 -- or operation (comparison op, membership test, or short circuit form)
7097 -- and the not in question is the left operand of this operation.
7098 -- Note that if the not is in parens, then false is returned.
7100 -----------------------
7101 -- Parent_Is_Boolean --
7102 -----------------------
7104 function Parent_Is_Boolean return Boolean is
7106 if Paren_Count (N) /= 0 then
7110 case Nkind (Parent (N)) is
7125 return Left_Opnd (Parent (N)) = N;
7131 end Parent_Is_Boolean;
7133 -- Start of processing for Resolve_Op_Not
7136 -- Predefined operations on scalar types yield the base type. On the
7137 -- other hand, logical operations on arrays yield the type of the
7138 -- arguments (and the context).
7140 if Is_Array_Type (Typ) then
7143 B_Typ := Base_Type (Typ);
7146 -- Straightforward case of incorrect arguments
7148 if not Valid_Boolean_Arg (Typ) then
7149 Error_Msg_N ("invalid operand type for operator&", N);
7150 Set_Etype (N, Any_Type);
7153 -- Special case of probable missing parens
7155 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7156 if Parent_Is_Boolean then
7158 ("operand of not must be enclosed in parentheses",
7162 ("no modular type available in this context", N);
7165 Set_Etype (N, Any_Type);
7168 -- OK resolution of not
7171 -- Warn if non-boolean types involved. This is a case like not a < b
7172 -- where a and b are modular, where we will get (not a) < b and most
7173 -- likely not (a < b) was intended.
7175 if Warn_On_Questionable_Missing_Parens
7176 and then not Is_Boolean_Type (Typ)
7177 and then Parent_Is_Boolean
7179 Error_Msg_N ("?not expression should be parenthesized here!", N);
7182 -- Warn on double negation if checking redundant constructs
7184 if Warn_On_Redundant_Constructs
7185 and then Comes_From_Source (N)
7186 and then Comes_From_Source (Right_Opnd (N))
7187 and then Root_Type (Typ) = Standard_Boolean
7188 and then Nkind (Right_Opnd (N)) = N_Op_Not
7190 Error_Msg_N ("redundant double negation?", N);
7193 -- Complete resolution and evaluation of NOT
7195 Resolve (Right_Opnd (N), B_Typ);
7196 Check_Unset_Reference (Right_Opnd (N));
7197 Set_Etype (N, B_Typ);
7198 Generate_Operator_Reference (N, B_Typ);
7203 -----------------------------
7204 -- Resolve_Operator_Symbol --
7205 -----------------------------
7207 -- Nothing to be done, all resolved already
7209 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7210 pragma Warnings (Off, N);
7211 pragma Warnings (Off, Typ);
7215 end Resolve_Operator_Symbol;
7217 ----------------------------------
7218 -- Resolve_Qualified_Expression --
7219 ----------------------------------
7221 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7222 pragma Warnings (Off, Typ);
7224 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7225 Expr : constant Node_Id := Expression (N);
7228 Resolve (Expr, Target_Typ);
7230 -- A qualified expression requires an exact match of the type,
7231 -- class-wide matching is not allowed. However, if the qualifying
7232 -- type is specific and the expression has a class-wide type, it
7233 -- may still be okay, since it can be the result of the expansion
7234 -- of a call to a dispatching function, so we also have to check
7235 -- class-wideness of the type of the expression's original node.
7237 if (Is_Class_Wide_Type (Target_Typ)
7239 (Is_Class_Wide_Type (Etype (Expr))
7240 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7241 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7243 Wrong_Type (Expr, Target_Typ);
7246 -- If the target type is unconstrained, then we reset the type of
7247 -- the result from the type of the expression. For other cases, the
7248 -- actual subtype of the expression is the target type.
7250 if Is_Composite_Type (Target_Typ)
7251 and then not Is_Constrained (Target_Typ)
7253 Set_Etype (N, Etype (Expr));
7256 Eval_Qualified_Expression (N);
7257 end Resolve_Qualified_Expression;
7263 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7264 L : constant Node_Id := Low_Bound (N);
7265 H : constant Node_Id := High_Bound (N);
7272 Check_Unset_Reference (L);
7273 Check_Unset_Reference (H);
7275 -- We have to check the bounds for being within the base range as
7276 -- required for a non-static context. Normally this is automatic and
7277 -- done as part of evaluating expressions, but the N_Range node is an
7278 -- exception, since in GNAT we consider this node to be a subexpression,
7279 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7280 -- this, but that would put the test on the main evaluation path for
7283 Check_Non_Static_Context (L);
7284 Check_Non_Static_Context (H);
7286 -- Check for an ambiguous range over character literals. This will
7287 -- happen with a membership test involving only literals.
7289 if Typ = Any_Character then
7290 Ambiguous_Character (L);
7291 Set_Etype (N, Any_Type);
7295 -- If bounds are static, constant-fold them, so size computations
7296 -- are identical between front-end and back-end. Do not perform this
7297 -- transformation while analyzing generic units, as type information
7298 -- would then be lost when reanalyzing the constant node in the
7301 if Is_Discrete_Type (Typ) and then Expander_Active then
7302 if Is_OK_Static_Expression (L) then
7303 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7306 if Is_OK_Static_Expression (H) then
7307 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7312 --------------------------
7313 -- Resolve_Real_Literal --
7314 --------------------------
7316 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7317 Actual_Typ : constant Entity_Id := Etype (N);
7320 -- Special processing for fixed-point literals to make sure that the
7321 -- value is an exact multiple of small where this is required. We
7322 -- skip this for the universal real case, and also for generic types.
7324 if Is_Fixed_Point_Type (Typ)
7325 and then Typ /= Universal_Fixed
7326 and then Typ /= Any_Fixed
7327 and then not Is_Generic_Type (Typ)
7330 Val : constant Ureal := Realval (N);
7331 Cintr : constant Ureal := Val / Small_Value (Typ);
7332 Cint : constant Uint := UR_Trunc (Cintr);
7333 Den : constant Uint := Norm_Den (Cintr);
7337 -- Case of literal is not an exact multiple of the Small
7341 -- For a source program literal for a decimal fixed-point
7342 -- type, this is statically illegal (RM 4.9(36)).
7344 if Is_Decimal_Fixed_Point_Type (Typ)
7345 and then Actual_Typ = Universal_Real
7346 and then Comes_From_Source (N)
7348 Error_Msg_N ("value has extraneous low order digits", N);
7351 -- Generate a warning if literal from source
7353 if Is_Static_Expression (N)
7354 and then Warn_On_Bad_Fixed_Value
7357 ("?static fixed-point value is not a multiple of Small!",
7361 -- Replace literal by a value that is the exact representation
7362 -- of a value of the type, i.e. a multiple of the small value,
7363 -- by truncation, since Machine_Rounds is false for all GNAT
7364 -- fixed-point types (RM 4.9(38)).
7366 Stat := Is_Static_Expression (N);
7368 Make_Real_Literal (Sloc (N),
7369 Realval => Small_Value (Typ) * Cint));
7371 Set_Is_Static_Expression (N, Stat);
7374 -- In all cases, set the corresponding integer field
7376 Set_Corresponding_Integer_Value (N, Cint);
7380 -- Now replace the actual type by the expected type as usual
7383 Eval_Real_Literal (N);
7384 end Resolve_Real_Literal;
7386 -----------------------
7387 -- Resolve_Reference --
7388 -----------------------
7390 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7391 P : constant Node_Id := Prefix (N);
7394 -- Replace general access with specific type
7396 if Ekind (Etype (N)) = E_Allocator_Type then
7397 Set_Etype (N, Base_Type (Typ));
7400 Resolve (P, Designated_Type (Etype (N)));
7402 -- If we are taking the reference of a volatile entity, then treat
7403 -- it as a potential modification of this entity. This is much too
7404 -- conservative, but is necessary because remove side effects can
7405 -- result in transformations of normal assignments into reference
7406 -- sequences that otherwise fail to notice the modification.
7408 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7409 Note_Possible_Modification (P, Sure => False);
7411 end Resolve_Reference;
7413 --------------------------------
7414 -- Resolve_Selected_Component --
7415 --------------------------------
7417 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7419 Comp1 : Entity_Id := Empty; -- prevent junk warning
7420 P : constant Node_Id := Prefix (N);
7421 S : constant Node_Id := Selector_Name (N);
7422 T : Entity_Id := Etype (P);
7424 I1 : Interp_Index := 0; -- prevent junk warning
7429 function Init_Component return Boolean;
7430 -- Check whether this is the initialization of a component within an
7431 -- init proc (by assignment or call to another init proc). If true,
7432 -- there is no need for a discriminant check.
7434 --------------------
7435 -- Init_Component --
7436 --------------------
7438 function Init_Component return Boolean is
7440 return Inside_Init_Proc
7441 and then Nkind (Prefix (N)) = N_Identifier
7442 and then Chars (Prefix (N)) = Name_uInit
7443 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7446 -- Start of processing for Resolve_Selected_Component
7449 if Is_Overloaded (P) then
7451 -- Use the context type to select the prefix that has a selector
7452 -- of the correct name and type.
7455 Get_First_Interp (P, I, It);
7457 Search : while Present (It.Typ) loop
7458 if Is_Access_Type (It.Typ) then
7459 T := Designated_Type (It.Typ);
7464 if Is_Record_Type (T) then
7466 -- The visible components of a class-wide type are those of
7469 if Is_Class_Wide_Type (T) then
7473 Comp := First_Entity (T);
7474 while Present (Comp) loop
7475 if Chars (Comp) = Chars (S)
7476 and then Covers (Etype (Comp), Typ)
7485 It := Disambiguate (P, I1, I, Any_Type);
7487 if It = No_Interp then
7489 ("ambiguous prefix for selected component", N);
7496 -- There may be an implicit dereference. Retrieve
7497 -- designated record type.
7499 if Is_Access_Type (It1.Typ) then
7500 T := Designated_Type (It1.Typ);
7505 if Scope (Comp1) /= T then
7507 -- Resolution chooses the new interpretation.
7508 -- Find the component with the right name.
7510 Comp1 := First_Entity (T);
7511 while Present (Comp1)
7512 and then Chars (Comp1) /= Chars (S)
7514 Comp1 := Next_Entity (Comp1);
7523 Comp := Next_Entity (Comp);
7528 Get_Next_Interp (I, It);
7531 Resolve (P, It1.Typ);
7533 Set_Entity_With_Style_Check (S, Comp1);
7536 -- Resolve prefix with its type
7541 -- Generate cross-reference. We needed to wait until full overloading
7542 -- resolution was complete to do this, since otherwise we can't tell if
7543 -- we are an Lvalue of not.
7545 if May_Be_Lvalue (N) then
7546 Generate_Reference (Entity (S), S, 'm');
7548 Generate_Reference (Entity (S), S, 'r');
7551 -- If prefix is an access type, the node will be transformed into an
7552 -- explicit dereference during expansion. The type of the node is the
7553 -- designated type of that of the prefix.
7555 if Is_Access_Type (Etype (P)) then
7556 T := Designated_Type (Etype (P));
7557 Check_Fully_Declared_Prefix (T, P);
7562 if Has_Discriminants (T)
7563 and then (Ekind (Entity (S)) = E_Component
7565 Ekind (Entity (S)) = E_Discriminant)
7566 and then Present (Original_Record_Component (Entity (S)))
7567 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7568 and then Present (Discriminant_Checking_Func
7569 (Original_Record_Component (Entity (S))))
7570 and then not Discriminant_Checks_Suppressed (T)
7571 and then not Init_Component
7573 Set_Do_Discriminant_Check (N);
7576 if Ekind (Entity (S)) = E_Void then
7577 Error_Msg_N ("premature use of component", S);
7580 -- If the prefix is a record conversion, this may be a renamed
7581 -- discriminant whose bounds differ from those of the original
7582 -- one, so we must ensure that a range check is performed.
7584 if Nkind (P) = N_Type_Conversion
7585 and then Ekind (Entity (S)) = E_Discriminant
7586 and then Is_Discrete_Type (Typ)
7588 Set_Etype (N, Base_Type (Typ));
7591 -- Note: No Eval processing is required, because the prefix is of a
7592 -- record type, or protected type, and neither can possibly be static.
7594 end Resolve_Selected_Component;
7600 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7601 B_Typ : constant Entity_Id := Base_Type (Typ);
7602 L : constant Node_Id := Left_Opnd (N);
7603 R : constant Node_Id := Right_Opnd (N);
7606 -- We do the resolution using the base type, because intermediate values
7607 -- in expressions always are of the base type, not a subtype of it.
7610 Resolve (R, Standard_Natural);
7612 Check_Unset_Reference (L);
7613 Check_Unset_Reference (R);
7615 Set_Etype (N, B_Typ);
7616 Generate_Operator_Reference (N, B_Typ);
7620 ---------------------------
7621 -- Resolve_Short_Circuit --
7622 ---------------------------
7624 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7625 B_Typ : constant Entity_Id := Base_Type (Typ);
7626 L : constant Node_Id := Left_Opnd (N);
7627 R : constant Node_Id := Right_Opnd (N);
7633 -- Check for issuing warning for always False assert/check, this happens
7634 -- when assertions are turned off, in which case the pragma Assert/Check
7635 -- was transformed into:
7637 -- if False and then <condition> then ...
7639 -- and we detect this pattern
7641 if Warn_On_Assertion_Failure
7642 and then Is_Entity_Name (R)
7643 and then Entity (R) = Standard_False
7644 and then Nkind (Parent (N)) = N_If_Statement
7645 and then Nkind (N) = N_And_Then
7646 and then Is_Entity_Name (L)
7647 and then Entity (L) = Standard_False
7650 Orig : constant Node_Id := Original_Node (Parent (N));
7653 if Nkind (Orig) = N_Pragma
7654 and then Pragma_Name (Orig) = Name_Assert
7656 -- Don't want to warn if original condition is explicit False
7659 Expr : constant Node_Id :=
7662 (First (Pragma_Argument_Associations (Orig))));
7664 if Is_Entity_Name (Expr)
7665 and then Entity (Expr) = Standard_False
7669 -- Issue warning. Note that we don't want to make this
7670 -- an unconditional warning, because if the assert is
7671 -- within deleted code we do not want the warning. But
7672 -- we do not want the deletion of the IF/AND-THEN to
7673 -- take this message with it. We achieve this by making
7674 -- sure that the expanded code points to the Sloc of
7675 -- the expression, not the original pragma.
7677 Error_Msg_N ("?assertion would fail at run-time", Orig);
7681 -- Similar processing for Check pragma
7683 elsif Nkind (Orig) = N_Pragma
7684 and then Pragma_Name (Orig) = Name_Check
7686 -- Don't want to warn if original condition is explicit False
7689 Expr : constant Node_Id :=
7693 (Pragma_Argument_Associations (Orig)))));
7695 if Is_Entity_Name (Expr)
7696 and then Entity (Expr) = Standard_False
7700 Error_Msg_N ("?check would fail at run-time", Orig);
7707 -- Continue with processing of short circuit
7709 Check_Unset_Reference (L);
7710 Check_Unset_Reference (R);
7712 Set_Etype (N, B_Typ);
7713 Eval_Short_Circuit (N);
7714 end Resolve_Short_Circuit;
7720 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7721 Name : constant Node_Id := Prefix (N);
7722 Drange : constant Node_Id := Discrete_Range (N);
7723 Array_Type : Entity_Id := Empty;
7727 if Is_Overloaded (Name) then
7729 -- Use the context type to select the prefix that yields the correct
7734 I1 : Interp_Index := 0;
7736 P : constant Node_Id := Prefix (N);
7737 Found : Boolean := False;
7740 Get_First_Interp (P, I, It);
7741 while Present (It.Typ) loop
7742 if (Is_Array_Type (It.Typ)
7743 and then Covers (Typ, It.Typ))
7744 or else (Is_Access_Type (It.Typ)
7745 and then Is_Array_Type (Designated_Type (It.Typ))
7746 and then Covers (Typ, Designated_Type (It.Typ)))
7749 It := Disambiguate (P, I1, I, Any_Type);
7751 if It = No_Interp then
7752 Error_Msg_N ("ambiguous prefix for slicing", N);
7757 Array_Type := It.Typ;
7762 Array_Type := It.Typ;
7767 Get_Next_Interp (I, It);
7772 Array_Type := Etype (Name);
7775 Resolve (Name, Array_Type);
7777 if Is_Access_Type (Array_Type) then
7778 Apply_Access_Check (N);
7779 Array_Type := Designated_Type (Array_Type);
7781 -- If the prefix is an access to an unconstrained array, we must use
7782 -- the actual subtype of the object to perform the index checks. The
7783 -- object denoted by the prefix is implicit in the node, so we build
7784 -- an explicit representation for it in order to compute the actual
7787 if not Is_Constrained (Array_Type) then
7788 Remove_Side_Effects (Prefix (N));
7791 Obj : constant Node_Id :=
7792 Make_Explicit_Dereference (Sloc (N),
7793 Prefix => New_Copy_Tree (Prefix (N)));
7795 Set_Etype (Obj, Array_Type);
7796 Set_Parent (Obj, Parent (N));
7797 Array_Type := Get_Actual_Subtype (Obj);
7801 elsif Is_Entity_Name (Name)
7802 or else (Nkind (Name) = N_Function_Call
7803 and then not Is_Constrained (Etype (Name)))
7805 Array_Type := Get_Actual_Subtype (Name);
7807 -- If the name is a selected component that depends on discriminants,
7808 -- build an actual subtype for it. This can happen only when the name
7809 -- itself is overloaded; otherwise the actual subtype is created when
7810 -- the selected component is analyzed.
7812 elsif Nkind (Name) = N_Selected_Component
7813 and then Full_Analysis
7814 and then Depends_On_Discriminant (First_Index (Array_Type))
7817 Act_Decl : constant Node_Id :=
7818 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7820 Insert_Action (N, Act_Decl);
7821 Array_Type := Defining_Identifier (Act_Decl);
7825 -- If name was overloaded, set slice type correctly now
7827 Set_Etype (N, Array_Type);
7829 -- If the range is specified by a subtype mark, no resolution is
7830 -- necessary. Else resolve the bounds, and apply needed checks.
7832 if not Is_Entity_Name (Drange) then
7833 Index := First_Index (Array_Type);
7834 Resolve (Drange, Base_Type (Etype (Index)));
7836 if Nkind (Drange) = N_Range
7838 -- Do not apply the range check to nodes associated with the
7839 -- frontend expansion of the dispatch table. We first check
7840 -- if Ada.Tags is already loaded to void the addition of an
7841 -- undesired dependence on such run-time unit.
7846 (RTU_Loaded (Ada_Tags)
7847 and then Nkind (Prefix (N)) = N_Selected_Component
7848 and then Present (Entity (Selector_Name (Prefix (N))))
7849 and then Entity (Selector_Name (Prefix (N))) =
7850 RTE_Record_Component (RE_Prims_Ptr)))
7852 Apply_Range_Check (Drange, Etype (Index));
7856 Set_Slice_Subtype (N);
7858 if Nkind (Drange) = N_Range then
7859 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7860 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7866 ----------------------------
7867 -- Resolve_String_Literal --
7868 ----------------------------
7870 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7871 C_Typ : constant Entity_Id := Component_Type (Typ);
7872 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7873 Loc : constant Source_Ptr := Sloc (N);
7874 Str : constant String_Id := Strval (N);
7875 Strlen : constant Nat := String_Length (Str);
7876 Subtype_Id : Entity_Id;
7877 Need_Check : Boolean;
7880 -- For a string appearing in a concatenation, defer creation of the
7881 -- string_literal_subtype until the end of the resolution of the
7882 -- concatenation, because the literal may be constant-folded away. This
7883 -- is a useful optimization for long concatenation expressions.
7885 -- If the string is an aggregate built for a single character (which
7886 -- happens in a non-static context) or a is null string to which special
7887 -- checks may apply, we build the subtype. Wide strings must also get a
7888 -- string subtype if they come from a one character aggregate. Strings
7889 -- generated by attributes might be static, but it is often hard to
7890 -- determine whether the enclosing context is static, so we generate
7891 -- subtypes for them as well, thus losing some rarer optimizations ???
7892 -- Same for strings that come from a static conversion.
7895 (Strlen = 0 and then Typ /= Standard_String)
7896 or else Nkind (Parent (N)) /= N_Op_Concat
7897 or else (N /= Left_Opnd (Parent (N))
7898 and then N /= Right_Opnd (Parent (N)))
7899 or else ((Typ = Standard_Wide_String
7900 or else Typ = Standard_Wide_Wide_String)
7901 and then Nkind (Original_Node (N)) /= N_String_Literal);
7903 -- If the resolving type is itself a string literal subtype, we can just
7904 -- reuse it, since there is no point in creating another.
7906 if Ekind (Typ) = E_String_Literal_Subtype then
7909 elsif Nkind (Parent (N)) = N_Op_Concat
7910 and then not Need_Check
7911 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7912 N_Attribute_Reference,
7913 N_Qualified_Expression,
7918 -- Otherwise we must create a string literal subtype. Note that the
7919 -- whole idea of string literal subtypes is simply to avoid the need
7920 -- for building a full fledged array subtype for each literal.
7923 Set_String_Literal_Subtype (N, Typ);
7924 Subtype_Id := Etype (N);
7927 if Nkind (Parent (N)) /= N_Op_Concat
7930 Set_Etype (N, Subtype_Id);
7931 Eval_String_Literal (N);
7934 if Is_Limited_Composite (Typ)
7935 or else Is_Private_Composite (Typ)
7937 Error_Msg_N ("string literal not available for private array", N);
7938 Set_Etype (N, Any_Type);
7942 -- The validity of a null string has been checked in the call to
7943 -- Eval_String_Literal.
7948 -- Always accept string literal with component type Any_Character, which
7949 -- occurs in error situations and in comparisons of literals, both of
7950 -- which should accept all literals.
7952 elsif R_Typ = Any_Character then
7955 -- If the type is bit-packed, then we always transform the string
7956 -- literal into a full fledged aggregate.
7958 elsif Is_Bit_Packed_Array (Typ) then
7961 -- Deal with cases of Wide_Wide_String, Wide_String, and String
7964 -- For Standard.Wide_Wide_String, or any other type whose component
7965 -- type is Standard.Wide_Wide_Character, we know that all the
7966 -- characters in the string must be acceptable, since the parser
7967 -- accepted the characters as valid character literals.
7969 if R_Typ = Standard_Wide_Wide_Character then
7972 -- For the case of Standard.String, or any other type whose component
7973 -- type is Standard.Character, we must make sure that there are no
7974 -- wide characters in the string, i.e. that it is entirely composed
7975 -- of characters in range of type Character.
7977 -- If the string literal is the result of a static concatenation, the
7978 -- test has already been performed on the components, and need not be
7981 elsif R_Typ = Standard_Character
7982 and then Nkind (Original_Node (N)) /= N_Op_Concat
7984 for J in 1 .. Strlen loop
7985 if not In_Character_Range (Get_String_Char (Str, J)) then
7987 -- If we are out of range, post error. This is one of the
7988 -- very few places that we place the flag in the middle of
7989 -- a token, right under the offending wide character. Not
7990 -- quite clear if this is right wrt wide character encoding
7991 -- sequences, but it's only an error message!
7994 ("literal out of range of type Standard.Character",
7995 Source_Ptr (Int (Loc) + J));
8000 -- For the case of Standard.Wide_String, or any other type whose
8001 -- component type is Standard.Wide_Character, we must make sure that
8002 -- there are no wide characters in the string, i.e. that it is
8003 -- entirely composed of characters in range of type Wide_Character.
8005 -- If the string literal is the result of a static concatenation,
8006 -- the test has already been performed on the components, and need
8009 elsif R_Typ = Standard_Wide_Character
8010 and then Nkind (Original_Node (N)) /= N_Op_Concat
8012 for J in 1 .. Strlen loop
8013 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8015 -- If we are out of range, post error. This is one of the
8016 -- very few places that we place the flag in the middle of
8017 -- a token, right under the offending wide character.
8019 -- This is not quite right, because characters in general
8020 -- will take more than one character position ???
8023 ("literal out of range of type Standard.Wide_Character",
8024 Source_Ptr (Int (Loc) + J));
8029 -- If the root type is not a standard character, then we will convert
8030 -- the string into an aggregate and will let the aggregate code do
8031 -- the checking. Standard Wide_Wide_Character is also OK here.
8037 -- See if the component type of the array corresponding to the string
8038 -- has compile time known bounds. If yes we can directly check
8039 -- whether the evaluation of the string will raise constraint error.
8040 -- Otherwise we need to transform the string literal into the
8041 -- corresponding character aggregate and let the aggregate
8042 -- code do the checking.
8044 if Is_Standard_Character_Type (R_Typ) then
8046 -- Check for the case of full range, where we are definitely OK
8048 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8052 -- Here the range is not the complete base type range, so check
8055 Comp_Typ_Lo : constant Node_Id :=
8056 Type_Low_Bound (Component_Type (Typ));
8057 Comp_Typ_Hi : constant Node_Id :=
8058 Type_High_Bound (Component_Type (Typ));
8063 if Compile_Time_Known_Value (Comp_Typ_Lo)
8064 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8066 for J in 1 .. Strlen loop
8067 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8069 if Char_Val < Expr_Value (Comp_Typ_Lo)
8070 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8072 Apply_Compile_Time_Constraint_Error
8073 (N, "character out of range?", CE_Range_Check_Failed,
8074 Loc => Source_Ptr (Int (Loc) + J));
8084 -- If we got here we meed to transform the string literal into the
8085 -- equivalent qualified positional array aggregate. This is rather
8086 -- heavy artillery for this situation, but it is hard work to avoid.
8089 Lits : constant List_Id := New_List;
8090 P : Source_Ptr := Loc + 1;
8094 -- Build the character literals, we give them source locations that
8095 -- correspond to the string positions, which is a bit tricky given
8096 -- the possible presence of wide character escape sequences.
8098 for J in 1 .. Strlen loop
8099 C := Get_String_Char (Str, J);
8100 Set_Character_Literal_Name (C);
8103 Make_Character_Literal (P,
8105 Char_Literal_Value => UI_From_CC (C)));
8107 if In_Character_Range (C) then
8110 -- Should we have a call to Skip_Wide here ???
8118 Make_Qualified_Expression (Loc,
8119 Subtype_Mark => New_Reference_To (Typ, Loc),
8121 Make_Aggregate (Loc, Expressions => Lits)));
8123 Analyze_And_Resolve (N, Typ);
8125 end Resolve_String_Literal;
8127 -----------------------------
8128 -- Resolve_Subprogram_Info --
8129 -----------------------------
8131 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8134 end Resolve_Subprogram_Info;
8136 -----------------------------
8137 -- Resolve_Type_Conversion --
8138 -----------------------------
8140 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8141 Conv_OK : constant Boolean := Conversion_OK (N);
8142 Operand : constant Node_Id := Expression (N);
8143 Operand_Typ : constant Entity_Id := Etype (Operand);
8144 Target_Typ : constant Entity_Id := Etype (N);
8151 and then not Valid_Conversion (N, Target_Typ, Operand)
8156 if Etype (Operand) = Any_Fixed then
8158 -- Mixed-mode operation involving a literal. Context must be a fixed
8159 -- type which is applied to the literal subsequently.
8161 if Is_Fixed_Point_Type (Typ) then
8162 Set_Etype (Operand, Universal_Real);
8164 elsif Is_Numeric_Type (Typ)
8165 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8166 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8168 Etype (Left_Opnd (Operand)) = Universal_Real)
8170 -- Return if expression is ambiguous
8172 if Unique_Fixed_Point_Type (N) = Any_Type then
8175 -- If nothing else, the available fixed type is Duration
8178 Set_Etype (Operand, Standard_Duration);
8181 -- Resolve the real operand with largest available precision
8183 if Etype (Right_Opnd (Operand)) = Universal_Real then
8184 Rop := New_Copy_Tree (Right_Opnd (Operand));
8186 Rop := New_Copy_Tree (Left_Opnd (Operand));
8189 Resolve (Rop, Universal_Real);
8191 -- If the operand is a literal (it could be a non-static and
8192 -- illegal exponentiation) check whether the use of Duration
8193 -- is potentially inaccurate.
8195 if Nkind (Rop) = N_Real_Literal
8196 and then Realval (Rop) /= Ureal_0
8197 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8200 ("?universal real operand can only " &
8201 "be interpreted as Duration!",
8204 ("\?precision will be lost in the conversion!", Rop);
8207 elsif Is_Numeric_Type (Typ)
8208 and then Nkind (Operand) in N_Op
8209 and then Unique_Fixed_Point_Type (N) /= Any_Type
8211 Set_Etype (Operand, Standard_Duration);
8214 Error_Msg_N ("invalid context for mixed mode operation", N);
8215 Set_Etype (Operand, Any_Type);
8222 -- Note: we do the Eval_Type_Conversion call before applying the
8223 -- required checks for a subtype conversion. This is important, since
8224 -- both are prepared under certain circumstances to change the type
8225 -- conversion to a constraint error node, but in the case of
8226 -- Eval_Type_Conversion this may reflect an illegality in the static
8227 -- case, and we would miss the illegality (getting only a warning
8228 -- message), if we applied the type conversion checks first.
8230 Eval_Type_Conversion (N);
8232 -- Even when evaluation is not possible, we may be able to simplify the
8233 -- conversion or its expression. This needs to be done before applying
8234 -- checks, since otherwise the checks may use the original expression
8235 -- and defeat the simplifications. This is specifically the case for
8236 -- elimination of the floating-point Truncation attribute in
8237 -- float-to-int conversions.
8239 Simplify_Type_Conversion (N);
8241 -- If after evaluation we still have a type conversion, then we may need
8242 -- to apply checks required for a subtype conversion.
8244 -- Skip these type conversion checks if universal fixed operands
8245 -- operands involved, since range checks are handled separately for
8246 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8248 if Nkind (N) = N_Type_Conversion
8249 and then not Is_Generic_Type (Root_Type (Target_Typ))
8250 and then Target_Typ /= Universal_Fixed
8251 and then Operand_Typ /= Universal_Fixed
8253 Apply_Type_Conversion_Checks (N);
8256 -- Issue warning for conversion of simple object to its own type. We
8257 -- have to test the original nodes, since they may have been rewritten
8258 -- by various optimizations.
8260 Orig_N := Original_Node (N);
8262 if Warn_On_Redundant_Constructs
8263 and then Comes_From_Source (Orig_N)
8264 and then Nkind (Orig_N) = N_Type_Conversion
8265 and then not In_Instance
8267 Orig_N := Original_Node (Expression (Orig_N));
8268 Orig_T := Target_Typ;
8270 -- If the node is part of a larger expression, the Target_Type
8271 -- may not be the original type of the node if the context is a
8272 -- condition. Recover original type to see if conversion is needed.
8274 if Is_Boolean_Type (Orig_T)
8275 and then Nkind (Parent (N)) in N_Op
8277 Orig_T := Etype (Parent (N));
8280 if Is_Entity_Name (Orig_N)
8282 (Etype (Entity (Orig_N)) = Orig_T
8284 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8285 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8287 Error_Msg_Node_2 := Orig_T;
8289 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8293 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8294 -- No need to perform any interface conversion if the type of the
8295 -- expression coincides with the target type.
8297 if Ada_Version >= Ada_05
8298 and then Expander_Active
8299 and then Operand_Typ /= Target_Typ
8302 Opnd : Entity_Id := Operand_Typ;
8303 Target : Entity_Id := Target_Typ;
8306 if Is_Access_Type (Opnd) then
8307 Opnd := Directly_Designated_Type (Opnd);
8310 if Is_Access_Type (Target_Typ) then
8311 Target := Directly_Designated_Type (Target);
8314 if Opnd = Target then
8317 -- Conversion from interface type
8319 elsif Is_Interface (Opnd) then
8321 -- Ada 2005 (AI-217): Handle entities from limited views
8323 if From_With_Type (Opnd) then
8324 Error_Msg_Qual_Level := 99;
8325 Error_Msg_NE ("missing WITH clause on package &", N,
8326 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8328 ("type conversions require visibility of the full view",
8331 elsif From_With_Type (Target)
8333 (Is_Access_Type (Target_Typ)
8334 and then Present (Non_Limited_View (Etype (Target))))
8336 Error_Msg_Qual_Level := 99;
8337 Error_Msg_NE ("missing WITH clause on package &", N,
8338 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8340 ("type conversions require visibility of the full view",
8344 Expand_Interface_Conversion (N, Is_Static => False);
8347 -- Conversion to interface type
8349 elsif Is_Interface (Target) then
8353 if Ekind (Opnd) = E_Protected_Subtype
8354 or else Ekind (Opnd) = E_Task_Subtype
8356 Opnd := Etype (Opnd);
8359 if not Interface_Present_In_Ancestor
8363 if Is_Class_Wide_Type (Opnd) then
8365 -- The static analysis is not enough to know if the
8366 -- interface is implemented or not. Hence we must pass
8367 -- the work to the expander to generate code to evaluate
8368 -- the conversion at run-time.
8370 Expand_Interface_Conversion (N, Is_Static => False);
8373 Error_Msg_Name_1 := Chars (Etype (Target));
8374 Error_Msg_Name_2 := Chars (Opnd);
8376 ("wrong interface conversion (% is not a progenitor " &
8381 Expand_Interface_Conversion (N);
8386 end Resolve_Type_Conversion;
8388 ----------------------
8389 -- Resolve_Unary_Op --
8390 ----------------------
8392 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8393 B_Typ : constant Entity_Id := Base_Type (Typ);
8394 R : constant Node_Id := Right_Opnd (N);
8400 -- Deal with intrinsic unary operators
8402 if Comes_From_Source (N)
8403 and then Ekind (Entity (N)) = E_Function
8404 and then Is_Imported (Entity (N))
8405 and then Is_Intrinsic_Subprogram (Entity (N))
8407 Resolve_Intrinsic_Unary_Operator (N, Typ);
8411 -- Deal with universal cases
8413 if Etype (R) = Universal_Integer
8415 Etype (R) = Universal_Real
8417 Check_For_Visible_Operator (N, B_Typ);
8420 Set_Etype (N, B_Typ);
8423 -- Generate warning for expressions like abs (x mod 2)
8425 if Warn_On_Redundant_Constructs
8426 and then Nkind (N) = N_Op_Abs
8428 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8430 if OK and then Hi >= Lo and then Lo >= 0 then
8432 ("?abs applied to known non-negative value has no effect", N);
8436 -- Deal with reference generation
8438 Check_Unset_Reference (R);
8439 Generate_Operator_Reference (N, B_Typ);
8442 -- Set overflow checking bit. Much cleverer code needed here eventually
8443 -- and perhaps the Resolve routines should be separated for the various
8444 -- arithmetic operations, since they will need different processing ???
8446 if Nkind (N) in N_Op then
8447 if not Overflow_Checks_Suppressed (Etype (N)) then
8448 Enable_Overflow_Check (N);
8452 -- Generate warning for expressions like -5 mod 3 for integers. No need
8453 -- to worry in the floating-point case, since parens do not affect the
8454 -- result so there is no point in giving in a warning.
8457 Norig : constant Node_Id := Original_Node (N);
8466 if Warn_On_Questionable_Missing_Parens
8467 and then Comes_From_Source (Norig)
8468 and then Is_Integer_Type (Typ)
8469 and then Nkind (Norig) = N_Op_Minus
8471 Rorig := Original_Node (Right_Opnd (Norig));
8473 -- We are looking for cases where the right operand is not
8474 -- parenthesized, and is a binary operator, multiply, divide, or
8475 -- mod. These are the cases where the grouping can affect results.
8477 if Paren_Count (Rorig) = 0
8478 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8480 -- For mod, we always give the warning, since the value is
8481 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8482 -- -(5 mod 315)). But for the other cases, the only concern is
8483 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8484 -- overflows, but (-2) * 64 does not). So we try to give the
8485 -- message only when overflow is possible.
8487 if Nkind (Rorig) /= N_Op_Mod
8488 and then Compile_Time_Known_Value (R)
8490 Val := Expr_Value (R);
8492 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8493 HB := Expr_Value (Type_High_Bound (Typ));
8495 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8498 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8499 LB := Expr_Value (Type_Low_Bound (Typ));
8501 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8504 -- Note that the test below is deliberately excluding the
8505 -- largest negative number, since that is a potentially
8506 -- troublesome case (e.g. -2 * x, where the result is the
8507 -- largest negative integer has an overflow with 2 * x).
8509 if Val > LB and then Val <= HB then
8514 -- For the multiplication case, the only case we have to worry
8515 -- about is when (-a)*b is exactly the largest negative number
8516 -- so that -(a*b) can cause overflow. This can only happen if
8517 -- a is a power of 2, and more generally if any operand is a
8518 -- constant that is not a power of 2, then the parentheses
8519 -- cannot affect whether overflow occurs. We only bother to
8520 -- test the left most operand
8522 -- Loop looking at left operands for one that has known value
8525 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8526 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8527 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8529 -- Operand value of 0 or 1 skips warning
8534 -- Otherwise check power of 2, if power of 2, warn, if
8535 -- anything else, skip warning.
8538 while Lval /= 2 loop
8539 if Lval mod 2 = 1 then
8550 -- Keep looking at left operands
8552 Opnd := Left_Opnd (Opnd);
8555 -- For rem or "/" we can only have a problematic situation
8556 -- if the divisor has a value of minus one or one. Otherwise
8557 -- overflow is impossible (divisor > 1) or we have a case of
8558 -- division by zero in any case.
8560 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8561 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8562 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8567 -- If we fall through warning should be issued
8570 ("?unary minus expression should be parenthesized here!", N);
8574 end Resolve_Unary_Op;
8576 ----------------------------------
8577 -- Resolve_Unchecked_Expression --
8578 ----------------------------------
8580 procedure Resolve_Unchecked_Expression
8585 Resolve (Expression (N), Typ, Suppress => All_Checks);
8587 end Resolve_Unchecked_Expression;
8589 ---------------------------------------
8590 -- Resolve_Unchecked_Type_Conversion --
8591 ---------------------------------------
8593 procedure Resolve_Unchecked_Type_Conversion
8597 pragma Warnings (Off, Typ);
8599 Operand : constant Node_Id := Expression (N);
8600 Opnd_Type : constant Entity_Id := Etype (Operand);
8603 -- Resolve operand using its own type
8605 Resolve (Operand, Opnd_Type);
8606 Eval_Unchecked_Conversion (N);
8608 end Resolve_Unchecked_Type_Conversion;
8610 ------------------------------
8611 -- Rewrite_Operator_As_Call --
8612 ------------------------------
8614 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8615 Loc : constant Source_Ptr := Sloc (N);
8616 Actuals : constant List_Id := New_List;
8620 if Nkind (N) in N_Binary_Op then
8621 Append (Left_Opnd (N), Actuals);
8624 Append (Right_Opnd (N), Actuals);
8627 Make_Function_Call (Sloc => Loc,
8628 Name => New_Occurrence_Of (Nam, Loc),
8629 Parameter_Associations => Actuals);
8631 Preserve_Comes_From_Source (New_N, N);
8632 Preserve_Comes_From_Source (Name (New_N), N);
8634 Set_Etype (N, Etype (Nam));
8635 end Rewrite_Operator_As_Call;
8637 ------------------------------
8638 -- Rewrite_Renamed_Operator --
8639 ------------------------------
8641 procedure Rewrite_Renamed_Operator
8646 Nam : constant Name_Id := Chars (Op);
8647 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8651 -- Rewrite the operator node using the real operator, not its renaming.
8652 -- Exclude user-defined intrinsic operations of the same name, which are
8653 -- treated separately and rewritten as calls.
8655 if Ekind (Op) /= E_Function
8656 or else Chars (N) /= Nam
8658 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8659 Set_Chars (Op_Node, Nam);
8660 Set_Etype (Op_Node, Etype (N));
8661 Set_Entity (Op_Node, Op);
8662 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8664 -- Indicate that both the original entity and its renaming are
8665 -- referenced at this point.
8667 Generate_Reference (Entity (N), N);
8668 Generate_Reference (Op, N);
8671 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8674 Rewrite (N, Op_Node);
8676 -- If the context type is private, add the appropriate conversions
8677 -- so that the operator is applied to the full view. This is done
8678 -- in the routines that resolve intrinsic operators,
8680 if Is_Intrinsic_Subprogram (Op)
8681 and then Is_Private_Type (Typ)
8684 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8685 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8686 Resolve_Intrinsic_Operator (N, Typ);
8688 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8689 Resolve_Intrinsic_Unary_Operator (N, Typ);
8696 elsif Ekind (Op) = E_Function
8697 and then Is_Intrinsic_Subprogram (Op)
8699 -- Operator renames a user-defined operator of the same name. Use
8700 -- the original operator in the node, which is the one that Gigi
8704 Set_Is_Overloaded (N, False);
8706 end Rewrite_Renamed_Operator;
8708 -----------------------
8709 -- Set_Slice_Subtype --
8710 -----------------------
8712 -- Build an implicit subtype declaration to represent the type delivered
8713 -- by the slice. This is an abbreviated version of an array subtype. We
8714 -- define an index subtype for the slice, using either the subtype name
8715 -- or the discrete range of the slice. To be consistent with index usage
8716 -- elsewhere, we create a list header to hold the single index. This list
8717 -- is not otherwise attached to the syntax tree.
8719 procedure Set_Slice_Subtype (N : Node_Id) is
8720 Loc : constant Source_Ptr := Sloc (N);
8721 Index_List : constant List_Id := New_List;
8723 Index_Subtype : Entity_Id;
8724 Index_Type : Entity_Id;
8725 Slice_Subtype : Entity_Id;
8726 Drange : constant Node_Id := Discrete_Range (N);
8729 if Is_Entity_Name (Drange) then
8730 Index_Subtype := Entity (Drange);
8733 -- We force the evaluation of a range. This is definitely needed in
8734 -- the renamed case, and seems safer to do unconditionally. Note in
8735 -- any case that since we will create and insert an Itype referring
8736 -- to this range, we must make sure any side effect removal actions
8737 -- are inserted before the Itype definition.
8739 if Nkind (Drange) = N_Range then
8740 Force_Evaluation (Low_Bound (Drange));
8741 Force_Evaluation (High_Bound (Drange));
8744 Index_Type := Base_Type (Etype (Drange));
8746 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8748 Set_Scalar_Range (Index_Subtype, Drange);
8749 Set_Etype (Index_Subtype, Index_Type);
8750 Set_Size_Info (Index_Subtype, Index_Type);
8751 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8754 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8756 Index := New_Occurrence_Of (Index_Subtype, Loc);
8757 Set_Etype (Index, Index_Subtype);
8758 Append (Index, Index_List);
8760 Set_First_Index (Slice_Subtype, Index);
8761 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8762 Set_Is_Constrained (Slice_Subtype, True);
8764 Check_Compile_Time_Size (Slice_Subtype);
8766 -- The Etype of the existing Slice node is reset to this slice subtype.
8767 -- Its bounds are obtained from its first index.
8769 Set_Etype (N, Slice_Subtype);
8771 -- In the packed case, this must be immediately frozen
8773 -- Couldn't we always freeze here??? and if we did, then the above
8774 -- call to Check_Compile_Time_Size could be eliminated, which would
8775 -- be nice, because then that routine could be made private to Freeze.
8777 -- Why the test for In_Spec_Expression here ???
8779 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8780 Freeze_Itype (Slice_Subtype, N);
8783 end Set_Slice_Subtype;
8785 --------------------------------
8786 -- Set_String_Literal_Subtype --
8787 --------------------------------
8789 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8790 Loc : constant Source_Ptr := Sloc (N);
8791 Low_Bound : constant Node_Id :=
8792 Type_Low_Bound (Etype (First_Index (Typ)));
8793 Subtype_Id : Entity_Id;
8796 if Nkind (N) /= N_String_Literal then
8800 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8801 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8802 (String_Length (Strval (N))));
8803 Set_Etype (Subtype_Id, Base_Type (Typ));
8804 Set_Is_Constrained (Subtype_Id);
8805 Set_Etype (N, Subtype_Id);
8807 if Is_OK_Static_Expression (Low_Bound) then
8809 -- The low bound is set from the low bound of the corresponding
8810 -- index type. Note that we do not store the high bound in the
8811 -- string literal subtype, but it can be deduced if necessary
8812 -- from the length and the low bound.
8814 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8817 Set_String_Literal_Low_Bound
8818 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8819 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8821 -- Build bona fide subtype for the string, and wrap it in an
8822 -- unchecked conversion, because the backend expects the
8823 -- String_Literal_Subtype to have a static lower bound.
8826 Index_List : constant List_Id := New_List;
8827 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8828 High_Bound : constant Node_Id :=
8830 Left_Opnd => New_Copy_Tree (Low_Bound),
8832 Make_Integer_Literal (Loc,
8833 String_Length (Strval (N)) - 1));
8834 Array_Subtype : Entity_Id;
8835 Index_Subtype : Entity_Id;
8841 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8842 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8843 Set_Scalar_Range (Index_Subtype, Drange);
8844 Set_Parent (Drange, N);
8845 Analyze_And_Resolve (Drange, Index_Type);
8847 -- In the context, the Index_Type may already have a constraint,
8848 -- so use common base type on string subtype. The base type may
8849 -- be used when generating attributes of the string, for example
8850 -- in the context of a slice assignment.
8852 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8853 Set_Size_Info (Index_Subtype, Index_Type);
8854 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8856 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8858 Index := New_Occurrence_Of (Index_Subtype, Loc);
8859 Set_Etype (Index, Index_Subtype);
8860 Append (Index, Index_List);
8862 Set_First_Index (Array_Subtype, Index);
8863 Set_Etype (Array_Subtype, Base_Type (Typ));
8864 Set_Is_Constrained (Array_Subtype, True);
8867 Make_Unchecked_Type_Conversion (Loc,
8868 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8869 Expression => Relocate_Node (N)));
8870 Set_Etype (N, Array_Subtype);
8873 end Set_String_Literal_Subtype;
8875 ------------------------------
8876 -- Simplify_Type_Conversion --
8877 ------------------------------
8879 procedure Simplify_Type_Conversion (N : Node_Id) is
8881 if Nkind (N) = N_Type_Conversion then
8883 Operand : constant Node_Id := Expression (N);
8884 Target_Typ : constant Entity_Id := Etype (N);
8885 Opnd_Typ : constant Entity_Id := Etype (Operand);
8888 if Is_Floating_Point_Type (Opnd_Typ)
8890 (Is_Integer_Type (Target_Typ)
8891 or else (Is_Fixed_Point_Type (Target_Typ)
8892 and then Conversion_OK (N)))
8893 and then Nkind (Operand) = N_Attribute_Reference
8894 and then Attribute_Name (Operand) = Name_Truncation
8896 -- Special processing required if the conversion is the expression
8897 -- of a Truncation attribute reference. In this case we replace:
8899 -- ityp (ftyp'Truncation (x))
8905 -- with the Float_Truncate flag set, which is more efficient
8909 Relocate_Node (First (Expressions (Operand))));
8910 Set_Float_Truncate (N, True);
8914 end Simplify_Type_Conversion;
8916 -----------------------------
8917 -- Unique_Fixed_Point_Type --
8918 -----------------------------
8920 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8921 T1 : Entity_Id := Empty;
8926 procedure Fixed_Point_Error;
8927 -- Give error messages for true ambiguity. Messages are posted on node
8928 -- N, and entities T1, T2 are the possible interpretations.
8930 -----------------------
8931 -- Fixed_Point_Error --
8932 -----------------------
8934 procedure Fixed_Point_Error is
8936 Error_Msg_N ("ambiguous universal_fixed_expression", N);
8937 Error_Msg_NE ("\\possible interpretation as}", N, T1);
8938 Error_Msg_NE ("\\possible interpretation as}", N, T2);
8939 end Fixed_Point_Error;
8941 -- Start of processing for Unique_Fixed_Point_Type
8944 -- The operations on Duration are visible, so Duration is always a
8945 -- possible interpretation.
8947 T1 := Standard_Duration;
8949 -- Look for fixed-point types in enclosing scopes
8951 Scop := Current_Scope;
8952 while Scop /= Standard_Standard loop
8953 T2 := First_Entity (Scop);
8954 while Present (T2) loop
8955 if Is_Fixed_Point_Type (T2)
8956 and then Current_Entity (T2) = T2
8957 and then Scope (Base_Type (T2)) = Scop
8959 if Present (T1) then
8970 Scop := Scope (Scop);
8973 -- Look for visible fixed type declarations in the context
8975 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
8976 while Present (Item) loop
8977 if Nkind (Item) = N_With_Clause then
8978 Scop := Entity (Name (Item));
8979 T2 := First_Entity (Scop);
8980 while Present (T2) loop
8981 if Is_Fixed_Point_Type (T2)
8982 and then Scope (Base_Type (T2)) = Scop
8983 and then (Is_Potentially_Use_Visible (T2)
8984 or else In_Use (T2))
8986 if Present (T1) then
9001 if Nkind (N) = N_Real_Literal then
9002 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9004 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9008 end Unique_Fixed_Point_Type;
9010 ----------------------
9011 -- Valid_Conversion --
9012 ----------------------
9014 function Valid_Conversion
9017 Operand : Node_Id) return Boolean
9019 Target_Type : constant Entity_Id := Base_Type (Target);
9020 Opnd_Type : Entity_Id := Etype (Operand);
9022 function Conversion_Check
9024 Msg : String) return Boolean;
9025 -- Little routine to post Msg if Valid is False, returns Valid value
9027 function Valid_Tagged_Conversion
9028 (Target_Type : Entity_Id;
9029 Opnd_Type : Entity_Id) return Boolean;
9030 -- Specifically test for validity of tagged conversions
9032 function Valid_Array_Conversion return Boolean;
9033 -- Check index and component conformance, and accessibility levels
9034 -- if the component types are anonymous access types (Ada 2005)
9036 ----------------------
9037 -- Conversion_Check --
9038 ----------------------
9040 function Conversion_Check
9042 Msg : String) return Boolean
9046 Error_Msg_N (Msg, Operand);
9050 end Conversion_Check;
9052 ----------------------------
9053 -- Valid_Array_Conversion --
9054 ----------------------------
9056 function Valid_Array_Conversion return Boolean
9058 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9059 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9061 Opnd_Index : Node_Id;
9062 Opnd_Index_Type : Entity_Id;
9064 Target_Comp_Type : constant Entity_Id :=
9065 Component_Type (Target_Type);
9066 Target_Comp_Base : constant Entity_Id :=
9067 Base_Type (Target_Comp_Type);
9069 Target_Index : Node_Id;
9070 Target_Index_Type : Entity_Id;
9073 -- Error if wrong number of dimensions
9076 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9079 ("incompatible number of dimensions for conversion", Operand);
9082 -- Number of dimensions matches
9085 -- Loop through indexes of the two arrays
9087 Target_Index := First_Index (Target_Type);
9088 Opnd_Index := First_Index (Opnd_Type);
9089 while Present (Target_Index) and then Present (Opnd_Index) loop
9090 Target_Index_Type := Etype (Target_Index);
9091 Opnd_Index_Type := Etype (Opnd_Index);
9093 -- Error if index types are incompatible
9095 if not (Is_Integer_Type (Target_Index_Type)
9096 and then Is_Integer_Type (Opnd_Index_Type))
9097 and then (Root_Type (Target_Index_Type)
9098 /= Root_Type (Opnd_Index_Type))
9101 ("incompatible index types for array conversion",
9106 Next_Index (Target_Index);
9107 Next_Index (Opnd_Index);
9110 -- If component types have same base type, all set
9112 if Target_Comp_Base = Opnd_Comp_Base then
9115 -- Here if base types of components are not the same. The only
9116 -- time this is allowed is if we have anonymous access types.
9118 -- The conversion of arrays of anonymous access types can lead
9119 -- to dangling pointers. AI-392 formalizes the accessibility
9120 -- checks that must be applied to such conversions to prevent
9121 -- out-of-scope references.
9124 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9126 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9127 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9129 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9131 if Type_Access_Level (Target_Type) <
9132 Type_Access_Level (Opnd_Type)
9134 if In_Instance_Body then
9135 Error_Msg_N ("?source array type " &
9136 "has deeper accessibility level than target", Operand);
9137 Error_Msg_N ("\?Program_Error will be raised at run time",
9140 Make_Raise_Program_Error (Sloc (N),
9141 Reason => PE_Accessibility_Check_Failed));
9142 Set_Etype (N, Target_Type);
9145 -- Conversion not allowed because of accessibility levels
9148 Error_Msg_N ("source array type " &
9149 "has deeper accessibility level than target", Operand);
9156 -- All other cases where component base types do not match
9160 ("incompatible component types for array conversion",
9165 -- Check that component subtypes statically match. For numeric
9166 -- types this means that both must be either constrained or
9167 -- unconstrained. For enumeration types the bounds must match.
9168 -- All of this is checked in Subtypes_Statically_Match.
9170 if not Subtypes_Statically_Match
9171 (Target_Comp_Type, Opnd_Comp_Type)
9174 ("component subtypes must statically match", Operand);
9180 end Valid_Array_Conversion;
9182 -----------------------------
9183 -- Valid_Tagged_Conversion --
9184 -----------------------------
9186 function Valid_Tagged_Conversion
9187 (Target_Type : Entity_Id;
9188 Opnd_Type : Entity_Id) return Boolean
9191 -- Upward conversions are allowed (RM 4.6(22))
9193 if Covers (Target_Type, Opnd_Type)
9194 or else Is_Ancestor (Target_Type, Opnd_Type)
9198 -- Downward conversion are allowed if the operand is class-wide
9201 elsif Is_Class_Wide_Type (Opnd_Type)
9202 and then Covers (Opnd_Type, Target_Type)
9206 elsif Covers (Opnd_Type, Target_Type)
9207 or else Is_Ancestor (Opnd_Type, Target_Type)
9210 Conversion_Check (False,
9211 "downward conversion of tagged objects not allowed");
9213 -- Ada 2005 (AI-251): The conversion to/from interface types is
9216 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9219 -- If the operand is a class-wide type obtained through a limited_
9220 -- with clause, and the context includes the non-limited view, use
9221 -- it to determine whether the conversion is legal.
9223 elsif Is_Class_Wide_Type (Opnd_Type)
9224 and then From_With_Type (Opnd_Type)
9225 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9226 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9230 elsif Is_Access_Type (Opnd_Type)
9231 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9237 ("invalid tagged conversion, not compatible with}",
9238 N, First_Subtype (Opnd_Type));
9241 end Valid_Tagged_Conversion;
9243 -- Start of processing for Valid_Conversion
9246 Check_Parameterless_Call (Operand);
9248 if Is_Overloaded (Operand) then
9257 -- Remove procedure calls, which syntactically cannot appear in
9258 -- this context, but which cannot be removed by type checking,
9259 -- because the context does not impose a type.
9261 -- When compiling for VMS, spurious ambiguities can be produced
9262 -- when arithmetic operations have a literal operand and return
9263 -- System.Address or a descendant of it. These ambiguities are
9264 -- otherwise resolved by the context, but for conversions there
9265 -- is no context type and the removal of the spurious operations
9266 -- must be done explicitly here.
9268 -- The node may be labelled overloaded, but still contain only
9269 -- one interpretation because others were discarded in previous
9270 -- filters. If this is the case, retain the single interpretation
9273 Get_First_Interp (Operand, I, It);
9274 Opnd_Type := It.Typ;
9275 Get_Next_Interp (I, It);
9278 and then Opnd_Type /= Standard_Void_Type
9280 -- More than one candidate interpretation is available
9282 Get_First_Interp (Operand, I, It);
9283 while Present (It.Typ) loop
9284 if It.Typ = Standard_Void_Type then
9288 if Present (System_Aux_Id)
9289 and then Is_Descendent_Of_Address (It.Typ)
9294 Get_Next_Interp (I, It);
9298 Get_First_Interp (Operand, I, It);
9303 Error_Msg_N ("illegal operand in conversion", Operand);
9307 Get_Next_Interp (I, It);
9309 if Present (It.Typ) then
9311 It1 := Disambiguate (Operand, I1, I, Any_Type);
9313 if It1 = No_Interp then
9314 Error_Msg_N ("ambiguous operand in conversion", Operand);
9316 Error_Msg_Sloc := Sloc (It.Nam);
9317 Error_Msg_N ("\\possible interpretation#!", Operand);
9319 Error_Msg_Sloc := Sloc (N1);
9320 Error_Msg_N ("\\possible interpretation#!", Operand);
9326 Set_Etype (Operand, It1.Typ);
9327 Opnd_Type := It1.Typ;
9333 if Is_Numeric_Type (Target_Type) then
9335 -- A universal fixed expression can be converted to any numeric type
9337 if Opnd_Type = Universal_Fixed then
9340 -- Also no need to check when in an instance or inlined body, because
9341 -- the legality has been established when the template was analyzed.
9342 -- Furthermore, numeric conversions may occur where only a private
9343 -- view of the operand type is visible at the instantiation point.
9344 -- This results in a spurious error if we check that the operand type
9345 -- is a numeric type.
9347 -- Note: in a previous version of this unit, the following tests were
9348 -- applied only for generated code (Comes_From_Source set to False),
9349 -- but in fact the test is required for source code as well, since
9350 -- this situation can arise in source code.
9352 elsif In_Instance or else In_Inlined_Body then
9355 -- Otherwise we need the conversion check
9358 return Conversion_Check
9359 (Is_Numeric_Type (Opnd_Type),
9360 "illegal operand for numeric conversion");
9365 elsif Is_Array_Type (Target_Type) then
9366 if not Is_Array_Type (Opnd_Type)
9367 or else Opnd_Type = Any_Composite
9368 or else Opnd_Type = Any_String
9371 ("illegal operand for array conversion", Operand);
9374 return Valid_Array_Conversion;
9377 -- Ada 2005 (AI-251): Anonymous access types where target references an
9380 elsif (Ekind (Target_Type) = E_General_Access_Type
9382 Ekind (Target_Type) = E_Anonymous_Access_Type)
9383 and then Is_Interface (Directly_Designated_Type (Target_Type))
9385 -- Check the static accessibility rule of 4.6(17). Note that the
9386 -- check is not enforced when within an instance body, since the
9387 -- RM requires such cases to be caught at run time.
9389 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9390 if Type_Access_Level (Opnd_Type) >
9391 Type_Access_Level (Target_Type)
9393 -- In an instance, this is a run-time check, but one we know
9394 -- will fail, so generate an appropriate warning. The raise
9395 -- will be generated by Expand_N_Type_Conversion.
9397 if In_Instance_Body then
9399 ("?cannot convert local pointer to non-local access type",
9402 ("\?Program_Error will be raised at run time", Operand);
9405 ("cannot convert local pointer to non-local access type",
9410 -- Special accessibility checks are needed in the case of access
9411 -- discriminants declared for a limited type.
9413 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9414 and then not Is_Local_Anonymous_Access (Opnd_Type)
9416 -- When the operand is a selected access discriminant the check
9417 -- needs to be made against the level of the object denoted by
9418 -- the prefix of the selected name (Object_Access_Level handles
9419 -- checking the prefix of the operand for this case).
9421 if Nkind (Operand) = N_Selected_Component
9422 and then Object_Access_Level (Operand) >
9423 Type_Access_Level (Target_Type)
9425 -- In an instance, this is a run-time check, but one we know
9426 -- will fail, so generate an appropriate warning. The raise
9427 -- will be generated by Expand_N_Type_Conversion.
9429 if In_Instance_Body then
9431 ("?cannot convert access discriminant to non-local" &
9432 " access type", Operand);
9434 ("\?Program_Error will be raised at run time", Operand);
9437 ("cannot convert access discriminant to non-local" &
9438 " access type", Operand);
9443 -- The case of a reference to an access discriminant from
9444 -- within a limited type declaration (which will appear as
9445 -- a discriminal) is always illegal because the level of the
9446 -- discriminant is considered to be deeper than any (nameable)
9449 if Is_Entity_Name (Operand)
9450 and then not Is_Local_Anonymous_Access (Opnd_Type)
9451 and then (Ekind (Entity (Operand)) = E_In_Parameter
9452 or else Ekind (Entity (Operand)) = E_Constant)
9453 and then Present (Discriminal_Link (Entity (Operand)))
9456 ("discriminant has deeper accessibility level than target",
9465 -- General and anonymous access types
9467 elsif (Ekind (Target_Type) = E_General_Access_Type
9468 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9471 (Is_Access_Type (Opnd_Type)
9472 and then Ekind (Opnd_Type) /=
9473 E_Access_Subprogram_Type
9474 and then Ekind (Opnd_Type) /=
9475 E_Access_Protected_Subprogram_Type,
9476 "must be an access-to-object type")
9478 if Is_Access_Constant (Opnd_Type)
9479 and then not Is_Access_Constant (Target_Type)
9482 ("access-to-constant operand type not allowed", Operand);
9486 -- Check the static accessibility rule of 4.6(17). Note that the
9487 -- check is not enforced when within an instance body, since the RM
9488 -- requires such cases to be caught at run time.
9490 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9491 or else Is_Local_Anonymous_Access (Target_Type)
9493 if Type_Access_Level (Opnd_Type)
9494 > Type_Access_Level (Target_Type)
9496 -- In an instance, this is a run-time check, but one we know
9497 -- will fail, so generate an appropriate warning. The raise
9498 -- will be generated by Expand_N_Type_Conversion.
9500 if In_Instance_Body then
9502 ("?cannot convert local pointer to non-local access type",
9505 ("\?Program_Error will be raised at run time", Operand);
9508 -- Avoid generation of spurious error message
9510 if not Error_Posted (N) then
9512 ("cannot convert local pointer to non-local access type",
9519 -- Special accessibility checks are needed in the case of access
9520 -- discriminants declared for a limited type.
9522 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9523 and then not Is_Local_Anonymous_Access (Opnd_Type)
9526 -- When the operand is a selected access discriminant the check
9527 -- needs to be made against the level of the object denoted by
9528 -- the prefix of the selected name (Object_Access_Level handles
9529 -- checking the prefix of the operand for this case).
9531 if Nkind (Operand) = N_Selected_Component
9532 and then Object_Access_Level (Operand) >
9533 Type_Access_Level (Target_Type)
9535 -- In an instance, this is a run-time check, but one we know
9536 -- will fail, so generate an appropriate warning. The raise
9537 -- will be generated by Expand_N_Type_Conversion.
9539 if In_Instance_Body then
9541 ("?cannot convert access discriminant to non-local" &
9542 " access type", Operand);
9544 ("\?Program_Error will be raised at run time",
9549 ("cannot convert access discriminant to non-local" &
9550 " access type", Operand);
9555 -- The case of a reference to an access discriminant from
9556 -- within a limited type declaration (which will appear as
9557 -- a discriminal) is always illegal because the level of the
9558 -- discriminant is considered to be deeper than any (nameable)
9561 if Is_Entity_Name (Operand)
9562 and then (Ekind (Entity (Operand)) = E_In_Parameter
9563 or else Ekind (Entity (Operand)) = E_Constant)
9564 and then Present (Discriminal_Link (Entity (Operand)))
9567 ("discriminant has deeper accessibility level than target",
9574 -- Need some comments here, and a name for this block ???
9577 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9578 -- Helper function to handle limited views
9580 --------------------------
9581 -- Full_Designated_Type --
9582 --------------------------
9584 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9585 Desig : constant Entity_Id := Designated_Type (T);
9587 if From_With_Type (Desig)
9588 and then Is_Incomplete_Type (Desig)
9589 and then Present (Non_Limited_View (Desig))
9591 return Non_Limited_View (Desig);
9595 end Full_Designated_Type;
9597 -- Local Declarations
9599 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9600 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9602 Same_Base : constant Boolean :=
9603 Base_Type (Target) = Base_Type (Opnd);
9605 -- Start of processing for ???
9608 if Is_Tagged_Type (Target) then
9609 return Valid_Tagged_Conversion (Target, Opnd);
9612 if not Same_Base then
9614 ("target designated type not compatible with }",
9615 N, Base_Type (Opnd));
9618 -- Ada 2005 AI-384: legality rule is symmetric in both
9619 -- designated types. The conversion is legal (with possible
9620 -- constraint check) if either designated type is
9623 elsif Subtypes_Statically_Match (Target, Opnd)
9625 (Has_Discriminants (Target)
9627 (not Is_Constrained (Opnd)
9628 or else not Is_Constrained (Target)))
9630 -- Special case, if Value_Size has been used to make the
9631 -- sizes different, the conversion is not allowed even
9632 -- though the subtypes statically match.
9634 if Known_Static_RM_Size (Target)
9635 and then Known_Static_RM_Size (Opnd)
9636 and then RM_Size (Target) /= RM_Size (Opnd)
9639 ("target designated subtype not compatible with }",
9642 ("\because sizes of the two designated subtypes differ",
9646 -- Normal case where conversion is allowed
9654 ("target designated subtype not compatible with }",
9661 -- Access to subprogram types. If the operand is an access parameter,
9662 -- the type has a deeper accessibility that any master, and cannot
9663 -- be assigned. We must make an exception if the conversion is part
9664 -- of an assignment and the target is the return object of an extended
9665 -- return statement, because in that case the accessibility check
9666 -- takes place after the return.
9668 elsif Is_Access_Subprogram_Type (Target_Type)
9669 and then No (Corresponding_Remote_Type (Opnd_Type))
9671 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9672 and then Is_Entity_Name (Operand)
9673 and then Ekind (Entity (Operand)) = E_In_Parameter
9675 (Nkind (Parent (N)) /= N_Assignment_Statement
9676 or else not Is_Entity_Name (Name (Parent (N)))
9677 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9680 ("illegal attempt to store anonymous access to subprogram",
9683 ("\value has deeper accessibility than any master " &
9688 ("\use named access type for& instead of access parameter",
9689 Operand, Entity (Operand));
9692 -- Check that the designated types are subtype conformant
9694 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9695 Old_Id => Designated_Type (Opnd_Type),
9698 -- Check the static accessibility rule of 4.6(20)
9700 if Type_Access_Level (Opnd_Type) >
9701 Type_Access_Level (Target_Type)
9704 ("operand type has deeper accessibility level than target",
9707 -- Check that if the operand type is declared in a generic body,
9708 -- then the target type must be declared within that same body
9709 -- (enforces last sentence of 4.6(20)).
9711 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9713 O_Gen : constant Node_Id :=
9714 Enclosing_Generic_Body (Opnd_Type);
9719 T_Gen := Enclosing_Generic_Body (Target_Type);
9720 while Present (T_Gen) and then T_Gen /= O_Gen loop
9721 T_Gen := Enclosing_Generic_Body (T_Gen);
9724 if T_Gen /= O_Gen then
9726 ("target type must be declared in same generic body"
9727 & " as operand type", N);
9734 -- Remote subprogram access types
9736 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9737 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9739 -- It is valid to convert from one RAS type to another provided
9740 -- that their specification statically match.
9742 Check_Subtype_Conformant
9744 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9746 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9751 -- If both are tagged types, check legality of view conversions
9753 elsif Is_Tagged_Type (Target_Type)
9754 and then Is_Tagged_Type (Opnd_Type)
9756 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9758 -- Types derived from the same root type are convertible
9760 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9763 -- In an instance or an inlined body, there may be inconsistent
9764 -- views of the same type, or of types derived from a common root.
9766 elsif (In_Instance or In_Inlined_Body)
9768 Root_Type (Underlying_Type (Target_Type)) =
9769 Root_Type (Underlying_Type (Opnd_Type))
9773 -- Special check for common access type error case
9775 elsif Ekind (Target_Type) = E_Access_Type
9776 and then Is_Access_Type (Opnd_Type)
9778 Error_Msg_N ("target type must be general access type!", N);
9779 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9783 Error_Msg_NE ("invalid conversion, not compatible with }",
9787 end Valid_Conversion;
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