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 Tbuild; use Tbuild;
76 with Uintp; use Uintp;
77 with Urealp; use Urealp;
79 package body Sem_Res is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the
87 -- type information recursively to the descendants of N. If the node
88 -- is not overloaded, its Etype is established in the first pass. If
89 -- overloaded, the Resolve routines set the correct type. For arith.
90 -- operators, the Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 procedure Check_Discriminant_Use (N : Node_Id);
95 -- Enforce the restrictions on the use of discriminants when constraining
96 -- a component of a discriminated type (record or concurrent type).
98 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
99 -- Given a node for an operator associated with type T, check that
100 -- the operator is visible. Operators all of whose operands are
101 -- universal must be checked for visibility during resolution
102 -- because their type is not determinable based on their operands.
104 procedure Check_Fully_Declared_Prefix
107 -- Check that the type of the prefix of a dereference is not incomplete
109 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
110 -- Given a call node, N, which is known to occur immediately within the
111 -- subprogram being called, determines whether it is a detectable case of
112 -- an infinite recursion, and if so, outputs appropriate messages. Returns
113 -- True if an infinite recursion is detected, and False otherwise.
115 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
116 -- If the type of the object being initialized uses the secondary stack
117 -- directly or indirectly, create a transient scope for the call to the
118 -- init proc. This is because we do not create transient scopes for the
119 -- initialization of individual components within the init proc itself.
120 -- Could be optimized away perhaps?
122 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
123 -- Determine whether E is an access type declared by an access
124 -- declaration, and not an (anonymous) allocator type.
126 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
127 -- Utility to check whether the name in the call is a predefined
128 -- operator, in which case the call is made into an operator node.
129 -- An instance of an intrinsic conversion operation may be given
130 -- an operator name, but is not treated like an operator.
132 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
133 -- If a default expression in entry call N depends on the discriminants
134 -- of the task, it must be replaced with a reference to the discriminant
135 -- of the task being called.
137 procedure Resolve_Op_Concat_Arg
142 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
143 -- concatenation operator. The operand is either of the array type or of
144 -- the component type. If the operand is an aggregate, and the component
145 -- type is composite, this is ambiguous if component type has aggregates.
147 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
148 -- Does the first part of the work of Resolve_Op_Concat
150 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
151 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
152 -- has been resolved. See Resolve_Op_Concat for details.
154 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
155 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
156 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
157 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
158 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
159 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
164 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
165 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
166 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
187 function Operator_Kind
189 Is_Binary : Boolean) return Node_Kind;
190 -- Utility to map the name of an operator into the corresponding Node. Used
191 -- by other node rewriting procedures.
193 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
194 -- Resolve actuals of call, and add default expressions for missing ones.
195 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
196 -- called subprogram.
198 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
199 -- Called from Resolve_Call, when the prefix denotes an entry or element
200 -- of entry family. Actuals are resolved as for subprograms, and the node
201 -- is rebuilt as an entry call. Also called for protected operations. Typ
202 -- is the context type, which is used when the operation is a protected
203 -- function with no arguments, and the return value is indexed.
205 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
206 -- A call to a user-defined intrinsic operator is rewritten as a call
207 -- to the corresponding predefined operator, with suitable conversions.
209 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
210 -- Ditto, for unary operators (only arithmetic ones)
212 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
213 -- If an operator node resolves to a call to a user-defined operator,
214 -- rewrite the node as a function call.
216 procedure Make_Call_Into_Operator
220 -- Inverse transformation: if an operator is given in functional notation,
221 -- then after resolving the node, transform into an operator node, so
222 -- that operands are resolved properly. Recall that predefined operators
223 -- do not have a full signature and special resolution rules apply.
225 procedure Rewrite_Renamed_Operator
229 -- An operator can rename another, e.g. in an instantiation. In that
230 -- case, the proper operator node must be constructed and resolved.
232 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
233 -- The String_Literal_Subtype is built for all strings that are not
234 -- operands of a static concatenation operation. If the argument is
235 -- not a N_String_Literal node, then the call has no effect.
237 procedure Set_Slice_Subtype (N : Node_Id);
238 -- Build subtype of array type, with the range specified by the slice
240 procedure Simplify_Type_Conversion (N : Node_Id);
241 -- Called after N has been resolved and evaluated, but before range checks
242 -- have been applied. Currently simplifies a combination of floating-point
243 -- to integer conversion and Truncation attribute.
245 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
246 -- A universal_fixed expression in an universal context is unambiguous
247 -- if there is only one applicable fixed point type. Determining whether
248 -- there is only one requires a search over all visible entities, and
249 -- happens only in very pathological cases (see 6115-006).
251 function Valid_Conversion
254 Operand : Node_Id) return Boolean;
255 -- Verify legality rules given in 4.6 (8-23). Target is the target
256 -- type of the conversion, which may be an implicit conversion of
257 -- an actual parameter to an anonymous access type (in which case
258 -- N denotes the actual parameter and N = Operand).
260 -------------------------
261 -- Ambiguous_Character --
262 -------------------------
264 procedure Ambiguous_Character (C : Node_Id) is
268 if Nkind (C) = N_Character_Literal then
269 Error_Msg_N ("ambiguous character literal", C);
271 -- First the ones in Standard
274 ("\\possible interpretation: Character!", C);
276 ("\\possible interpretation: Wide_Character!", C);
278 -- Include Wide_Wide_Character in Ada 2005 mode
280 if Ada_Version >= Ada_05 then
282 ("\\possible interpretation: Wide_Wide_Character!", C);
285 -- Now any other types that match
287 E := Current_Entity (C);
288 while Present (E) loop
289 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
293 end Ambiguous_Character;
295 -------------------------
296 -- Analyze_And_Resolve --
297 -------------------------
299 procedure Analyze_And_Resolve (N : Node_Id) is
303 end Analyze_And_Resolve;
305 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
309 end Analyze_And_Resolve;
311 -- Version withs check(s) suppressed
313 procedure Analyze_And_Resolve
318 Scop : constant Entity_Id := Current_Scope;
321 if Suppress = All_Checks then
323 Svg : constant Suppress_Array := Scope_Suppress;
325 Scope_Suppress := (others => True);
326 Analyze_And_Resolve (N, Typ);
327 Scope_Suppress := Svg;
332 Svg : constant Boolean := Scope_Suppress (Suppress);
335 Scope_Suppress (Suppress) := True;
336 Analyze_And_Resolve (N, Typ);
337 Scope_Suppress (Suppress) := Svg;
341 if Current_Scope /= Scop
342 and then Scope_Is_Transient
344 -- This can only happen if a transient scope was created
345 -- for an inner expression, which will be removed upon
346 -- completion of the analysis of an enclosing construct.
347 -- The transient scope must have the suppress status of
348 -- the enclosing environment, not of this Analyze call.
350 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
353 end Analyze_And_Resolve;
355 procedure Analyze_And_Resolve
359 Scop : constant Entity_Id := Current_Scope;
362 if Suppress = All_Checks then
364 Svg : constant Suppress_Array := Scope_Suppress;
366 Scope_Suppress := (others => True);
367 Analyze_And_Resolve (N);
368 Scope_Suppress := Svg;
373 Svg : constant Boolean := Scope_Suppress (Suppress);
376 Scope_Suppress (Suppress) := True;
377 Analyze_And_Resolve (N);
378 Scope_Suppress (Suppress) := Svg;
382 if Current_Scope /= Scop
383 and then Scope_Is_Transient
385 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
388 end Analyze_And_Resolve;
390 ----------------------------
391 -- Check_Discriminant_Use --
392 ----------------------------
394 procedure Check_Discriminant_Use (N : Node_Id) is
395 PN : constant Node_Id := Parent (N);
396 Disc : constant Entity_Id := Entity (N);
401 -- Any use in a spec-expression is legal
403 if In_Spec_Expression then
406 elsif Nkind (PN) = N_Range then
408 -- Discriminant cannot be used to constrain a scalar type
412 if Nkind (P) = N_Range_Constraint
413 and then Nkind (Parent (P)) = N_Subtype_Indication
414 and then Nkind (Parent (Parent (P))) = N_Component_Definition
416 Error_Msg_N ("discriminant cannot constrain scalar type", N);
418 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
420 -- The following check catches the unusual case where
421 -- a discriminant appears within an index constraint
422 -- that is part of a larger expression within a constraint
423 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
424 -- For now we only check case of record components, and
425 -- note that a similar check should also apply in the
426 -- case of discriminant constraints below. ???
428 -- Note that the check for N_Subtype_Declaration below is to
429 -- detect the valid use of discriminants in the constraints of a
430 -- subtype declaration when this subtype declaration appears
431 -- inside the scope of a record type (which is syntactically
432 -- illegal, but which may be created as part of derived type
433 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
436 if Ekind (Current_Scope) = E_Record_Type
437 and then Scope (Disc) = Current_Scope
439 (Nkind (Parent (P)) = N_Subtype_Indication
441 Nkind_In (Parent (Parent (P)), N_Component_Definition,
442 N_Subtype_Declaration)
443 and then Paren_Count (N) = 0)
446 ("discriminant must appear alone in component constraint", N);
450 -- Detect a common error:
452 -- type R (D : Positive := 100) is record
453 -- Name : String (1 .. D);
456 -- The default value causes an object of type R to be allocated
457 -- with room for Positive'Last characters. The RM does not mandate
458 -- the allocation of the maximum size, but that is what GNAT does
459 -- so we should warn the programmer that there is a problem.
461 Check_Large : declare
467 function Large_Storage_Type (T : Entity_Id) return Boolean;
468 -- Return True if type T has a large enough range that
469 -- any array whose index type covered the whole range of
470 -- the type would likely raise Storage_Error.
472 ------------------------
473 -- Large_Storage_Type --
474 ------------------------
476 function Large_Storage_Type (T : Entity_Id) return Boolean is
478 -- The type is considered large if its bounds are known at
479 -- compile time and if it requires at least as many bits as
480 -- a Positive to store the possible values.
482 return Compile_Time_Known_Value (Type_Low_Bound (T))
483 and then Compile_Time_Known_Value (Type_High_Bound (T))
485 Minimum_Size (T, Biased => True) >=
486 RM_Size (Standard_Positive);
487 end Large_Storage_Type;
489 -- Start of processing for Check_Large
492 -- Check that the Disc has a large range
494 if not Large_Storage_Type (Etype (Disc)) then
498 -- If the enclosing type is limited, we allocate only the
499 -- default value, not the maximum, and there is no need for
502 if Is_Limited_Type (Scope (Disc)) then
506 -- Check that it is the high bound
508 if N /= High_Bound (PN)
509 or else No (Discriminant_Default_Value (Disc))
514 -- Check the array allows a large range at this bound.
515 -- First find the array
519 if Nkind (SI) /= N_Subtype_Indication then
523 T := Entity (Subtype_Mark (SI));
525 if not Is_Array_Type (T) then
529 -- Next, find the dimension
531 TB := First_Index (T);
532 CB := First (Constraints (P));
534 and then Present (TB)
535 and then Present (CB)
546 -- Now, check the dimension has a large range
548 if not Large_Storage_Type (Etype (TB)) then
552 -- Warn about the danger
555 ("?creation of & object may raise Storage_Error!",
564 -- Legal case is in index or discriminant constraint
566 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
567 N_Discriminant_Association)
569 if Paren_Count (N) > 0 then
571 ("discriminant in constraint must appear alone", N);
573 elsif Nkind (N) = N_Expanded_Name
574 and then Comes_From_Source (N)
577 ("discriminant must appear alone as a direct name", N);
582 -- Otherwise, context is an expression. It should not be within
583 -- (i.e. a subexpression of) a constraint for a component.
588 while not Nkind_In (P, N_Component_Declaration,
589 N_Subtype_Indication,
597 -- If the discriminant is used in an expression that is a bound
598 -- of a scalar type, an Itype is created and the bounds are attached
599 -- to its range, not to the original subtype indication. Such use
600 -- is of course a double fault.
602 if (Nkind (P) = N_Subtype_Indication
603 and then Nkind_In (Parent (P), N_Component_Definition,
604 N_Derived_Type_Definition)
605 and then D = Constraint (P))
607 -- The constraint itself may be given by a subtype indication,
608 -- rather than by a more common discrete range.
610 or else (Nkind (P) = N_Subtype_Indication
612 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
613 or else Nkind (P) = N_Entry_Declaration
614 or else Nkind (D) = N_Defining_Identifier
617 ("discriminant in constraint must appear alone", N);
620 end Check_Discriminant_Use;
622 --------------------------------
623 -- Check_For_Visible_Operator --
624 --------------------------------
626 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
628 if Is_Invisible_Operator (N, T) then
630 ("operator for} is not directly visible!", N, First_Subtype (T));
631 Error_Msg_N ("use clause would make operation legal!", N);
633 end Check_For_Visible_Operator;
635 ----------------------------------
636 -- Check_Fully_Declared_Prefix --
637 ----------------------------------
639 procedure Check_Fully_Declared_Prefix
644 -- Check that the designated type of the prefix of a dereference is
645 -- not an incomplete type. This cannot be done unconditionally, because
646 -- dereferences of private types are legal in default expressions. This
647 -- case is taken care of in Check_Fully_Declared, called below. There
648 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
650 -- This consideration also applies to similar checks for allocators,
651 -- qualified expressions, and type conversions.
653 -- An additional exception concerns other per-object expressions that
654 -- are not directly related to component declarations, in particular
655 -- representation pragmas for tasks. These will be per-object
656 -- expressions if they depend on discriminants or some global entity.
657 -- If the task has access discriminants, the designated type may be
658 -- incomplete at the point the expression is resolved. This resolution
659 -- takes place within the body of the initialization procedure, where
660 -- the discriminant is replaced by its discriminal.
662 if Is_Entity_Name (Pref)
663 and then Ekind (Entity (Pref)) = E_In_Parameter
667 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
668 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
669 -- Analyze_Object_Renaming, and Freeze_Entity.
671 elsif Ada_Version >= Ada_05
672 and then Is_Entity_Name (Pref)
673 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
675 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
679 Check_Fully_Declared (Typ, Parent (Pref));
681 end Check_Fully_Declared_Prefix;
683 ------------------------------
684 -- Check_Infinite_Recursion --
685 ------------------------------
687 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
691 function Same_Argument_List return Boolean;
692 -- Check whether list of actuals is identical to list of formals
693 -- of called function (which is also the enclosing scope).
695 ------------------------
696 -- Same_Argument_List --
697 ------------------------
699 function Same_Argument_List return Boolean is
705 if not Is_Entity_Name (Name (N)) then
708 Subp := Entity (Name (N));
711 F := First_Formal (Subp);
712 A := First_Actual (N);
713 while Present (F) and then Present (A) loop
714 if not Is_Entity_Name (A)
715 or else Entity (A) /= F
725 end Same_Argument_List;
727 -- Start of processing for Check_Infinite_Recursion
730 -- Special case, if this is a procedure call and is a call to the
731 -- current procedure with the same argument list, then this is for
732 -- sure an infinite recursion and we insert a call to raise SE.
734 if Is_List_Member (N)
735 and then List_Length (List_Containing (N)) = 1
736 and then Same_Argument_List
739 P : constant Node_Id := Parent (N);
741 if Nkind (P) = N_Handled_Sequence_Of_Statements
742 and then Nkind (Parent (P)) = N_Subprogram_Body
743 and then Is_Empty_List (Declarations (Parent (P)))
745 Error_Msg_N ("!?infinite recursion", N);
746 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
748 Make_Raise_Storage_Error (Sloc (N),
749 Reason => SE_Infinite_Recursion));
755 -- If not that special case, search up tree, quitting if we reach a
756 -- construct (e.g. a conditional) that tells us that this is not a
757 -- case for an infinite recursion warning.
763 -- If no parent, then we were not inside a subprogram, this can for
764 -- example happen when processing certain pragmas in a spec. Just
765 -- return False in this case.
771 -- Done if we get to subprogram body, this is definitely an infinite
772 -- recursion case if we did not find anything to stop us.
774 exit when Nkind (P) = N_Subprogram_Body;
776 -- If appearing in conditional, result is false
778 if Nkind_In (P, N_Or_Else,
785 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
786 and then C /= First (Statements (P))
788 -- If the call is the expression of a return statement and the
789 -- actuals are identical to the formals, it's worth a warning.
790 -- However, we skip this if there is an immediately preceding
791 -- raise statement, since the call is never executed.
793 -- Furthermore, this corresponds to a common idiom:
795 -- function F (L : Thing) return Boolean is
797 -- raise Program_Error;
801 -- for generating a stub function
803 if Nkind (Parent (N)) = N_Simple_Return_Statement
804 and then Same_Argument_List
806 exit when not Is_List_Member (Parent (N));
808 -- OK, return statement is in a statement list, look for raise
814 -- Skip past N_Freeze_Entity nodes generated by expansion
816 Nod := Prev (Parent (N));
818 and then Nkind (Nod) = N_Freeze_Entity
823 -- If no raise statement, give warning
825 exit when Nkind (Nod) /= N_Raise_Statement
827 (Nkind (Nod) not in N_Raise_xxx_Error
828 or else Present (Condition (Nod)));
839 Error_Msg_N ("!?possible infinite recursion", N);
840 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
843 end Check_Infinite_Recursion;
845 -------------------------------
846 -- Check_Initialization_Call --
847 -------------------------------
849 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
850 Typ : constant Entity_Id := Etype (First_Formal (Nam));
852 function Uses_SS (T : Entity_Id) return Boolean;
853 -- Check whether the creation of an object of the type will involve
854 -- use of the secondary stack. If T is a record type, this is true
855 -- if the expression for some component uses the secondary stack, e.g.
856 -- through a call to a function that returns an unconstrained value.
857 -- False if T is controlled, because cleanups occur elsewhere.
863 function Uses_SS (T : Entity_Id) return Boolean is
866 Full_Type : Entity_Id := Underlying_Type (T);
869 -- Normally we want to use the underlying type, but if it's not set
870 -- then continue with T.
872 if not Present (Full_Type) then
876 if Is_Controlled (Full_Type) then
879 elsif Is_Array_Type (Full_Type) then
880 return Uses_SS (Component_Type (Full_Type));
882 elsif Is_Record_Type (Full_Type) then
883 Comp := First_Component (Full_Type);
884 while Present (Comp) loop
885 if Ekind (Comp) = E_Component
886 and then Nkind (Parent (Comp)) = N_Component_Declaration
888 -- The expression for a dynamic component may be rewritten
889 -- as a dereference, so retrieve original node.
891 Expr := Original_Node (Expression (Parent (Comp)));
893 -- Return True if the expression is a call to a function
894 -- (including an attribute function such as Image) with
895 -- a result that requires a transient scope.
897 if (Nkind (Expr) = N_Function_Call
898 or else (Nkind (Expr) = N_Attribute_Reference
899 and then Present (Expressions (Expr))))
900 and then Requires_Transient_Scope (Etype (Expr))
904 elsif Uses_SS (Etype (Comp)) then
909 Next_Component (Comp);
919 -- Start of processing for Check_Initialization_Call
922 -- Establish a transient scope if the type needs it
924 if Uses_SS (Typ) then
925 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
927 end Check_Initialization_Call;
929 ------------------------------
930 -- Check_Parameterless_Call --
931 ------------------------------
933 procedure Check_Parameterless_Call (N : Node_Id) is
936 function Prefix_Is_Access_Subp return Boolean;
937 -- If the prefix is of an access_to_subprogram type, the node must be
938 -- rewritten as a call. Ditto if the prefix is overloaded and all its
939 -- interpretations are access to subprograms.
941 ---------------------------
942 -- Prefix_Is_Access_Subp --
943 ---------------------------
945 function Prefix_Is_Access_Subp return Boolean is
950 if not Is_Overloaded (N) then
952 Ekind (Etype (N)) = E_Subprogram_Type
953 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
955 Get_First_Interp (N, I, It);
956 while Present (It.Typ) loop
957 if Ekind (It.Typ) /= E_Subprogram_Type
958 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
963 Get_Next_Interp (I, It);
968 end Prefix_Is_Access_Subp;
970 -- Start of processing for Check_Parameterless_Call
973 -- Defend against junk stuff if errors already detected
975 if Total_Errors_Detected /= 0 then
976 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
978 elsif Nkind (N) in N_Has_Chars
979 and then Chars (N) in Error_Name_Or_No_Name
987 -- If the context expects a value, and the name is a procedure, this is
988 -- most likely a missing 'Access. Don't try to resolve the parameterless
989 -- call, error will be caught when the outer call is analyzed.
991 if Is_Entity_Name (N)
992 and then Ekind (Entity (N)) = E_Procedure
993 and then not Is_Overloaded (N)
995 Nkind_In (Parent (N), N_Parameter_Association,
997 N_Procedure_Call_Statement)
1002 -- Rewrite as call if overloadable entity that is (or could be, in the
1003 -- overloaded case) a function call. If we know for sure that the entity
1004 -- is an enumeration literal, we do not rewrite it.
1006 if (Is_Entity_Name (N)
1007 and then Is_Overloadable (Entity (N))
1008 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1009 or else Is_Overloaded (N)))
1011 -- Rewrite as call if it is an explicit deference of an expression of
1012 -- a subprogram access type, and the subprogram type is not that of a
1013 -- procedure or entry.
1016 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1018 -- Rewrite as call if it is a selected component which is a function,
1019 -- this is the case of a call to a protected function (which may be
1020 -- overloaded with other protected operations).
1023 (Nkind (N) = N_Selected_Component
1024 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1026 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1028 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1029 and then Is_Overloaded (Selector_Name (N)))))
1031 -- If one of the above three conditions is met, rewrite as call.
1032 -- Apply the rewriting only once.
1035 if Nkind (Parent (N)) /= N_Function_Call
1036 or else N /= Name (Parent (N))
1038 Nam := New_Copy (N);
1040 -- If overloaded, overload set belongs to new copy
1042 Save_Interps (N, Nam);
1044 -- Change node to parameterless function call (note that the
1045 -- Parameter_Associations associations field is left set to Empty,
1046 -- its normal default value since there are no parameters)
1048 Change_Node (N, N_Function_Call);
1050 Set_Sloc (N, Sloc (Nam));
1054 elsif Nkind (N) = N_Parameter_Association then
1055 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1057 end Check_Parameterless_Call;
1059 -----------------------------
1060 -- Is_Definite_Access_Type --
1061 -----------------------------
1063 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1064 Btyp : constant Entity_Id := Base_Type (E);
1066 return Ekind (Btyp) = E_Access_Type
1067 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1068 and then Comes_From_Source (Btyp));
1069 end Is_Definite_Access_Type;
1071 ----------------------
1072 -- Is_Predefined_Op --
1073 ----------------------
1075 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1077 return Is_Intrinsic_Subprogram (Nam)
1078 and then not Is_Generic_Instance (Nam)
1079 and then Chars (Nam) in Any_Operator_Name
1080 and then (No (Alias (Nam))
1081 or else Is_Predefined_Op (Alias (Nam)));
1082 end Is_Predefined_Op;
1084 -----------------------------
1085 -- Make_Call_Into_Operator --
1086 -----------------------------
1088 procedure Make_Call_Into_Operator
1093 Op_Name : constant Name_Id := Chars (Op_Id);
1094 Act1 : Node_Id := First_Actual (N);
1095 Act2 : Node_Id := Next_Actual (Act1);
1096 Error : Boolean := False;
1097 Func : constant Entity_Id := Entity (Name (N));
1098 Is_Binary : constant Boolean := Present (Act2);
1100 Opnd_Type : Entity_Id;
1101 Orig_Type : Entity_Id := Empty;
1104 type Kind_Test is access function (E : Entity_Id) return Boolean;
1106 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1107 -- If the operand is not universal, and the operator is given by a
1108 -- expanded name, verify that the operand has an interpretation with
1109 -- a type defined in the given scope of the operator.
1111 function Type_In_P (Test : Kind_Test) return Entity_Id;
1112 -- Find a type of the given class in the package Pack that contains
1115 ---------------------------
1116 -- Operand_Type_In_Scope --
1117 ---------------------------
1119 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1120 Nod : constant Node_Id := Right_Opnd (Op_Node);
1125 if not Is_Overloaded (Nod) then
1126 return Scope (Base_Type (Etype (Nod))) = S;
1129 Get_First_Interp (Nod, I, It);
1130 while Present (It.Typ) loop
1131 if Scope (Base_Type (It.Typ)) = S then
1135 Get_Next_Interp (I, It);
1140 end Operand_Type_In_Scope;
1146 function Type_In_P (Test : Kind_Test) return Entity_Id is
1149 function In_Decl return Boolean;
1150 -- Verify that node is not part of the type declaration for the
1151 -- candidate type, which would otherwise be invisible.
1157 function In_Decl return Boolean is
1158 Decl_Node : constant Node_Id := Parent (E);
1164 if Etype (E) = Any_Type then
1167 elsif No (Decl_Node) then
1172 and then Nkind (N2) /= N_Compilation_Unit
1174 if N2 = Decl_Node then
1185 -- Start of processing for Type_In_P
1188 -- If the context type is declared in the prefix package, this
1189 -- is the desired base type.
1191 if Scope (Base_Type (Typ)) = Pack
1194 return Base_Type (Typ);
1197 E := First_Entity (Pack);
1198 while Present (E) loop
1200 and then not In_Decl
1212 -- Start of processing for Make_Call_Into_Operator
1215 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1220 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1221 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1222 Save_Interps (Act1, Left_Opnd (Op_Node));
1223 Save_Interps (Act2, Right_Opnd (Op_Node));
1224 Act1 := Left_Opnd (Op_Node);
1225 Act2 := Right_Opnd (Op_Node);
1230 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1231 Save_Interps (Act1, Right_Opnd (Op_Node));
1232 Act1 := Right_Opnd (Op_Node);
1235 -- If the operator is denoted by an expanded name, and the prefix is
1236 -- not Standard, but the operator is a predefined one whose scope is
1237 -- Standard, then this is an implicit_operator, inserted as an
1238 -- interpretation by the procedure of the same name. This procedure
1239 -- overestimates the presence of implicit operators, because it does
1240 -- not examine the type of the operands. Verify now that the operand
1241 -- type appears in the given scope. If right operand is universal,
1242 -- check the other operand. In the case of concatenation, either
1243 -- argument can be the component type, so check the type of the result.
1244 -- If both arguments are literals, look for a type of the right kind
1245 -- defined in the given scope. This elaborate nonsense is brought to
1246 -- you courtesy of b33302a. The type itself must be frozen, so we must
1247 -- find the type of the proper class in the given scope.
1249 -- A final wrinkle is the multiplication operator for fixed point
1250 -- types, which is defined in Standard only, and not in the scope of
1251 -- the fixed_point type itself.
1253 if Nkind (Name (N)) = N_Expanded_Name then
1254 Pack := Entity (Prefix (Name (N)));
1256 -- If the entity being called is defined in the given package,
1257 -- it is a renaming of a predefined operator, and known to be
1260 if Scope (Entity (Name (N))) = Pack
1261 and then Pack /= Standard_Standard
1265 -- Visibility does not need to be checked in an instance: if the
1266 -- operator was not visible in the generic it has been diagnosed
1267 -- already, else there is an implicit copy of it in the instance.
1269 elsif In_Instance then
1272 elsif (Op_Name = Name_Op_Multiply
1273 or else Op_Name = Name_Op_Divide)
1274 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1275 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1277 if Pack /= Standard_Standard then
1281 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1284 elsif Ada_Version >= Ada_05
1285 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1286 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1291 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1293 if Op_Name = Name_Op_Concat then
1294 Opnd_Type := Base_Type (Typ);
1296 elsif (Scope (Opnd_Type) = Standard_Standard
1298 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1300 and then not Comes_From_Source (Opnd_Type))
1302 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1305 if Scope (Opnd_Type) = Standard_Standard then
1307 -- Verify that the scope contains a type that corresponds to
1308 -- the given literal. Optimize the case where Pack is Standard.
1310 if Pack /= Standard_Standard then
1312 if Opnd_Type = Universal_Integer then
1313 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1315 elsif Opnd_Type = Universal_Real then
1316 Orig_Type := Type_In_P (Is_Real_Type'Access);
1318 elsif Opnd_Type = Any_String then
1319 Orig_Type := Type_In_P (Is_String_Type'Access);
1321 elsif Opnd_Type = Any_Access then
1322 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1324 elsif Opnd_Type = Any_Composite then
1325 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1327 if Present (Orig_Type) then
1328 if Has_Private_Component (Orig_Type) then
1331 Set_Etype (Act1, Orig_Type);
1334 Set_Etype (Act2, Orig_Type);
1343 Error := No (Orig_Type);
1346 elsif Ekind (Opnd_Type) = E_Allocator_Type
1347 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1351 -- If the type is defined elsewhere, and the operator is not
1352 -- defined in the given scope (by a renaming declaration, e.g.)
1353 -- then this is an error as well. If an extension of System is
1354 -- present, and the type may be defined there, Pack must be
1357 elsif Scope (Opnd_Type) /= Pack
1358 and then Scope (Op_Id) /= Pack
1359 and then (No (System_Aux_Id)
1360 or else Scope (Opnd_Type) /= System_Aux_Id
1361 or else Pack /= Scope (System_Aux_Id))
1363 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1366 Error := not Operand_Type_In_Scope (Pack);
1369 elsif Pack = Standard_Standard
1370 and then not Operand_Type_In_Scope (Standard_Standard)
1377 Error_Msg_Node_2 := Pack;
1379 ("& not declared in&", N, Selector_Name (Name (N)));
1380 Set_Etype (N, Any_Type);
1385 Set_Chars (Op_Node, Op_Name);
1387 if not Is_Private_Type (Etype (N)) then
1388 Set_Etype (Op_Node, Base_Type (Etype (N)));
1390 Set_Etype (Op_Node, Etype (N));
1393 -- If this is a call to a function that renames a predefined equality,
1394 -- the renaming declaration provides a type that must be used to
1395 -- resolve the operands. This must be done now because resolution of
1396 -- the equality node will not resolve any remaining ambiguity, and it
1397 -- assumes that the first operand is not overloaded.
1399 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1400 and then Ekind (Func) = E_Function
1401 and then Is_Overloaded (Act1)
1403 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1404 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1407 Set_Entity (Op_Node, Op_Id);
1408 Generate_Reference (Op_Id, N, ' ');
1410 -- Do rewrite setting Comes_From_Source on the result if the original
1411 -- call came from source. Although it is not strictly the case that the
1412 -- operator as such comes from the source, logically it corresponds
1413 -- exactly to the function call in the source, so it should be marked
1414 -- this way (e.g. to make sure that validity checks work fine).
1417 CS : constant Boolean := Comes_From_Source (N);
1419 Rewrite (N, Op_Node);
1420 Set_Comes_From_Source (N, CS);
1423 -- If this is an arithmetic operator and the result type is private,
1424 -- the operands and the result must be wrapped in conversion to
1425 -- expose the underlying numeric type and expand the proper checks,
1426 -- e.g. on division.
1428 if Is_Private_Type (Typ) then
1430 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1431 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1432 Resolve_Intrinsic_Operator (N, Typ);
1434 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1435 Resolve_Intrinsic_Unary_Operator (N, Typ);
1444 -- For predefined operators on literals, the operation freezes
1447 if Present (Orig_Type) then
1448 Set_Etype (Act1, Orig_Type);
1449 Freeze_Expression (Act1);
1451 end Make_Call_Into_Operator;
1457 function Operator_Kind
1459 Is_Binary : Boolean) return Node_Kind
1465 if Op_Name = Name_Op_And then
1467 elsif Op_Name = Name_Op_Or then
1469 elsif Op_Name = Name_Op_Xor then
1471 elsif Op_Name = Name_Op_Eq then
1473 elsif Op_Name = Name_Op_Ne then
1475 elsif Op_Name = Name_Op_Lt then
1477 elsif Op_Name = Name_Op_Le then
1479 elsif Op_Name = Name_Op_Gt then
1481 elsif Op_Name = Name_Op_Ge then
1483 elsif Op_Name = Name_Op_Add then
1485 elsif Op_Name = Name_Op_Subtract then
1486 Kind := N_Op_Subtract;
1487 elsif Op_Name = Name_Op_Concat then
1488 Kind := N_Op_Concat;
1489 elsif Op_Name = Name_Op_Multiply then
1490 Kind := N_Op_Multiply;
1491 elsif Op_Name = Name_Op_Divide then
1492 Kind := N_Op_Divide;
1493 elsif Op_Name = Name_Op_Mod then
1495 elsif Op_Name = Name_Op_Rem then
1497 elsif Op_Name = Name_Op_Expon then
1500 raise Program_Error;
1506 if Op_Name = Name_Op_Add then
1508 elsif Op_Name = Name_Op_Subtract then
1510 elsif Op_Name = Name_Op_Abs then
1512 elsif Op_Name = Name_Op_Not then
1515 raise Program_Error;
1522 ----------------------------
1523 -- Preanalyze_And_Resolve --
1524 ----------------------------
1526 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1527 Save_Full_Analysis : constant Boolean := Full_Analysis;
1530 Full_Analysis := False;
1531 Expander_Mode_Save_And_Set (False);
1533 -- We suppress all checks for this analysis, since the checks will
1534 -- be applied properly, and in the right location, when the default
1535 -- expression is reanalyzed and reexpanded later on.
1537 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1539 Expander_Mode_Restore;
1540 Full_Analysis := Save_Full_Analysis;
1541 end Preanalyze_And_Resolve;
1543 -- Version without context type
1545 procedure Preanalyze_And_Resolve (N : Node_Id) is
1546 Save_Full_Analysis : constant Boolean := Full_Analysis;
1549 Full_Analysis := False;
1550 Expander_Mode_Save_And_Set (False);
1553 Resolve (N, Etype (N), Suppress => All_Checks);
1555 Expander_Mode_Restore;
1556 Full_Analysis := Save_Full_Analysis;
1557 end Preanalyze_And_Resolve;
1559 ----------------------------------
1560 -- Replace_Actual_Discriminants --
1561 ----------------------------------
1563 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1564 Loc : constant Source_Ptr := Sloc (N);
1565 Tsk : Node_Id := Empty;
1567 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1573 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1577 if Nkind (Nod) = N_Identifier then
1578 Ent := Entity (Nod);
1581 and then Ekind (Ent) = E_Discriminant
1584 Make_Selected_Component (Loc,
1585 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1586 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1588 Set_Etype (Nod, Etype (Ent));
1596 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1598 -- Start of processing for Replace_Actual_Discriminants
1601 if not Expander_Active then
1605 if Nkind (Name (N)) = N_Selected_Component then
1606 Tsk := Prefix (Name (N));
1608 elsif Nkind (Name (N)) = N_Indexed_Component then
1609 Tsk := Prefix (Prefix (Name (N)));
1615 Replace_Discrs (Default);
1617 end Replace_Actual_Discriminants;
1623 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1624 Ambiguous : Boolean := False;
1625 Ctx_Type : Entity_Id := Typ;
1626 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1627 Err_Type : Entity_Id := Empty;
1628 Found : Boolean := False;
1631 I1 : Interp_Index := 0; -- prevent junk warning
1634 Seen : Entity_Id := Empty; -- prevent junk warning
1636 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1637 -- Determine whether a node comes from a predefined library unit or
1640 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1641 -- Try and fix up a literal so that it matches its expected type. New
1642 -- literals are manufactured if necessary to avoid cascaded errors.
1644 procedure Resolution_Failed;
1645 -- Called when attempt at resolving current expression fails
1647 ------------------------------------
1648 -- Comes_From_Predefined_Lib_Unit --
1649 -------------------------------------
1651 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1654 Sloc (Nod) = Standard_Location
1655 or else Is_Predefined_File_Name (Unit_File_Name (
1656 Get_Source_Unit (Sloc (Nod))));
1657 end Comes_From_Predefined_Lib_Unit;
1659 --------------------
1660 -- Patch_Up_Value --
1661 --------------------
1663 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1665 if Nkind (N) = N_Integer_Literal
1666 and then Is_Real_Type (Typ)
1669 Make_Real_Literal (Sloc (N),
1670 Realval => UR_From_Uint (Intval (N))));
1671 Set_Etype (N, Universal_Real);
1672 Set_Is_Static_Expression (N);
1674 elsif Nkind (N) = N_Real_Literal
1675 and then Is_Integer_Type (Typ)
1678 Make_Integer_Literal (Sloc (N),
1679 Intval => UR_To_Uint (Realval (N))));
1680 Set_Etype (N, Universal_Integer);
1681 Set_Is_Static_Expression (N);
1683 elsif Nkind (N) = N_String_Literal
1684 and then Is_Character_Type (Typ)
1686 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1688 Make_Character_Literal (Sloc (N),
1690 Char_Literal_Value =>
1691 UI_From_Int (Character'Pos ('A'))));
1692 Set_Etype (N, Any_Character);
1693 Set_Is_Static_Expression (N);
1695 elsif Nkind (N) /= N_String_Literal
1696 and then Is_String_Type (Typ)
1699 Make_String_Literal (Sloc (N),
1700 Strval => End_String));
1702 elsif Nkind (N) = N_Range then
1703 Patch_Up_Value (Low_Bound (N), Typ);
1704 Patch_Up_Value (High_Bound (N), Typ);
1708 -----------------------
1709 -- Resolution_Failed --
1710 -----------------------
1712 procedure Resolution_Failed is
1714 Patch_Up_Value (N, Typ);
1716 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1717 Set_Is_Overloaded (N, False);
1719 -- The caller will return without calling the expander, so we need
1720 -- to set the analyzed flag. Note that it is fine to set Analyzed
1721 -- to True even if we are in the middle of a shallow analysis,
1722 -- (see the spec of sem for more details) since this is an error
1723 -- situation anyway, and there is no point in repeating the
1724 -- analysis later (indeed it won't work to repeat it later, since
1725 -- we haven't got a clear resolution of which entity is being
1728 Set_Analyzed (N, True);
1730 end Resolution_Failed;
1732 -- Start of processing for Resolve
1739 -- Access attribute on remote subprogram cannot be used for
1740 -- a non-remote access-to-subprogram type.
1742 if Nkind (N) = N_Attribute_Reference
1743 and then (Attribute_Name (N) = Name_Access
1744 or else Attribute_Name (N) = Name_Unrestricted_Access
1745 or else Attribute_Name (N) = Name_Unchecked_Access)
1746 and then Comes_From_Source (N)
1747 and then Is_Entity_Name (Prefix (N))
1748 and then Is_Subprogram (Entity (Prefix (N)))
1749 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1750 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1753 ("prefix must statically denote a non-remote subprogram", N);
1756 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1758 -- If the context is a Remote_Access_To_Subprogram, access attributes
1759 -- must be resolved with the corresponding fat pointer. There is no need
1760 -- to check for the attribute name since the return type of an
1761 -- attribute is never a remote type.
1763 if Nkind (N) = N_Attribute_Reference
1764 and then Comes_From_Source (N)
1765 and then (Is_Remote_Call_Interface (Typ)
1766 or else Is_Remote_Types (Typ))
1769 Attr : constant Attribute_Id :=
1770 Get_Attribute_Id (Attribute_Name (N));
1771 Pref : constant Node_Id := Prefix (N);
1774 Is_Remote : Boolean := True;
1777 -- Check that Typ is a remote access-to-subprogram type
1779 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1780 -- Prefix (N) must statically denote a remote subprogram
1781 -- declared in a package specification.
1783 if Attr = Attribute_Access then
1784 Decl := Unit_Declaration_Node (Entity (Pref));
1786 if Nkind (Decl) = N_Subprogram_Body then
1787 Spec := Corresponding_Spec (Decl);
1789 if not No (Spec) then
1790 Decl := Unit_Declaration_Node (Spec);
1794 Spec := Parent (Decl);
1796 if not Is_Entity_Name (Prefix (N))
1797 or else Nkind (Spec) /= N_Package_Specification
1799 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1803 ("prefix must statically denote a remote subprogram ",
1808 -- If we are generating code for a distributed program.
1809 -- perform semantic checks against the corresponding
1812 if (Attr = Attribute_Access
1813 or else Attr = Attribute_Unchecked_Access
1814 or else Attr = Attribute_Unrestricted_Access)
1815 and then Expander_Active
1816 and then Get_PCS_Name /= Name_No_DSA
1818 Check_Subtype_Conformant
1819 (New_Id => Entity (Prefix (N)),
1820 Old_Id => Designated_Type
1821 (Corresponding_Remote_Type (Typ)),
1825 Process_Remote_AST_Attribute (N, Typ);
1832 Debug_A_Entry ("resolving ", N);
1834 if Comes_From_Source (N) then
1835 if Is_Fixed_Point_Type (Typ) then
1836 Check_Restriction (No_Fixed_Point, N);
1838 elsif Is_Floating_Point_Type (Typ)
1839 and then Typ /= Universal_Real
1840 and then Typ /= Any_Real
1842 Check_Restriction (No_Floating_Point, N);
1846 -- Return if already analyzed
1848 if Analyzed (N) then
1849 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1852 -- Return if type = Any_Type (previous error encountered)
1854 elsif Etype (N) = Any_Type then
1855 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1859 Check_Parameterless_Call (N);
1861 -- If not overloaded, then we know the type, and all that needs doing
1862 -- is to check that this type is compatible with the context.
1864 if not Is_Overloaded (N) then
1865 Found := Covers (Typ, Etype (N));
1866 Expr_Type := Etype (N);
1868 -- In the overloaded case, we must select the interpretation that
1869 -- is compatible with the context (i.e. the type passed to Resolve)
1872 -- Loop through possible interpretations
1874 Get_First_Interp (N, I, It);
1875 Interp_Loop : while Present (It.Typ) loop
1877 -- We are only interested in interpretations that are compatible
1878 -- with the expected type, any other interpretations are ignored.
1880 if not Covers (Typ, It.Typ) then
1881 if Debug_Flag_V then
1882 Write_Str (" interpretation incompatible with context");
1887 -- Skip the current interpretation if it is disabled by an
1888 -- abstract operator. This action is performed only when the
1889 -- type against which we are resolving is the same as the
1890 -- type of the interpretation.
1892 if Ada_Version >= Ada_05
1893 and then It.Typ = Typ
1894 and then Typ /= Universal_Integer
1895 and then Typ /= Universal_Real
1896 and then Present (It.Abstract_Op)
1901 -- First matching interpretation
1907 Expr_Type := It.Typ;
1909 -- Matching interpretation that is not the first, maybe an
1910 -- error, but there are some cases where preference rules are
1911 -- used to choose between the two possibilities. These and
1912 -- some more obscure cases are handled in Disambiguate.
1915 -- If the current statement is part of a predefined library
1916 -- unit, then all interpretations which come from user level
1917 -- packages should not be considered.
1920 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1925 Error_Msg_Sloc := Sloc (Seen);
1926 It1 := Disambiguate (N, I1, I, Typ);
1928 -- Disambiguation has succeeded. Skip the remaining
1931 if It1 /= No_Interp then
1933 Expr_Type := It1.Typ;
1935 while Present (It.Typ) loop
1936 Get_Next_Interp (I, It);
1940 -- Before we issue an ambiguity complaint, check for
1941 -- the case of a subprogram call where at least one
1942 -- of the arguments is Any_Type, and if so, suppress
1943 -- the message, since it is a cascaded error.
1945 if Nkind_In (N, N_Function_Call,
1946 N_Procedure_Call_Statement)
1953 A := First_Actual (N);
1954 while Present (A) loop
1957 if Nkind (E) = N_Parameter_Association then
1958 E := Explicit_Actual_Parameter (E);
1961 if Etype (E) = Any_Type then
1962 if Debug_Flag_V then
1963 Write_Str ("Any_Type in call");
1974 elsif Nkind (N) in N_Binary_Op
1975 and then (Etype (Left_Opnd (N)) = Any_Type
1976 or else Etype (Right_Opnd (N)) = Any_Type)
1980 elsif Nkind (N) in N_Unary_Op
1981 and then Etype (Right_Opnd (N)) = Any_Type
1986 -- Not that special case, so issue message using the
1987 -- flag Ambiguous to control printing of the header
1988 -- message only at the start of an ambiguous set.
1990 if not Ambiguous then
1991 if Nkind (N) = N_Function_Call
1992 and then Nkind (Name (N)) = N_Explicit_Dereference
1995 ("ambiguous expression "
1996 & "(cannot resolve indirect call)!", N);
1998 Error_Msg_NE -- CODEFIX
1999 ("ambiguous expression (cannot resolve&)!",
2005 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2007 ("\\possible interpretation (inherited)#!", N);
2009 Error_Msg_N -- CODEFIX
2010 ("\\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 -- CODEFIX
2093 ("\\possible interpretation#!", N);
2099 -- We have a matching interpretation, Expr_Type is the type
2100 -- from this interpretation, and Seen is the entity.
2102 -- For an operator, just set the entity name. The type will be
2103 -- set by the specific operator resolution routine.
2105 if Nkind (N) in N_Op then
2106 Set_Entity (N, Seen);
2107 Generate_Reference (Seen, N);
2109 elsif Nkind (N) = N_Character_Literal then
2110 Set_Etype (N, Expr_Type);
2112 -- For an explicit dereference, attribute reference, range,
2113 -- short-circuit form (which is not an operator node), or call
2114 -- with a name that is an explicit dereference, there is
2115 -- nothing to be done at this point.
2117 elsif Nkind_In (N, N_Explicit_Dereference,
2118 N_Attribute_Reference,
2120 N_Indexed_Component,
2123 N_Selected_Component,
2125 or else Nkind (Name (N)) = N_Explicit_Dereference
2129 -- For procedure or function calls, set the type of the name,
2130 -- and also the entity pointer for the prefix
2132 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2133 and then (Is_Entity_Name (Name (N))
2134 or else Nkind (Name (N)) = N_Operator_Symbol)
2136 Set_Etype (Name (N), Expr_Type);
2137 Set_Entity (Name (N), Seen);
2138 Generate_Reference (Seen, Name (N));
2140 elsif Nkind (N) = N_Function_Call
2141 and then Nkind (Name (N)) = N_Selected_Component
2143 Set_Etype (Name (N), Expr_Type);
2144 Set_Entity (Selector_Name (Name (N)), Seen);
2145 Generate_Reference (Seen, Selector_Name (Name (N)));
2147 -- For all other cases, just set the type of the Name
2150 Set_Etype (Name (N), Expr_Type);
2157 -- Move to next interpretation
2159 exit Interp_Loop when No (It.Typ);
2161 Get_Next_Interp (I, It);
2162 end loop Interp_Loop;
2165 -- At this stage Found indicates whether or not an acceptable
2166 -- interpretation exists. If not, then we have an error, except
2167 -- that if the context is Any_Type as a result of some other error,
2168 -- then we suppress the error report.
2171 if Typ /= Any_Type then
2173 -- If type we are looking for is Void, then this is the procedure
2174 -- call case, and the error is simply that what we gave is not a
2175 -- procedure name (we think of procedure calls as expressions with
2176 -- types internally, but the user doesn't think of them this way!)
2178 if Typ = Standard_Void_Type then
2180 -- Special case message if function used as a procedure
2182 if Nkind (N) = N_Procedure_Call_Statement
2183 and then Is_Entity_Name (Name (N))
2184 and then Ekind (Entity (Name (N))) = E_Function
2187 ("cannot use function & in a procedure call",
2188 Name (N), Entity (Name (N)));
2190 -- Otherwise give general message (not clear what cases this
2191 -- covers, but no harm in providing for them!)
2194 Error_Msg_N ("expect procedure name in procedure call", N);
2199 -- Otherwise we do have a subexpression with the wrong type
2201 -- Check for the case of an allocator which uses an access type
2202 -- instead of the designated type. This is a common error and we
2203 -- specialize the message, posting an error on the operand of the
2204 -- allocator, complaining that we expected the designated type of
2207 elsif Nkind (N) = N_Allocator
2208 and then Ekind (Typ) in Access_Kind
2209 and then Ekind (Etype (N)) in Access_Kind
2210 and then Designated_Type (Etype (N)) = Typ
2212 Wrong_Type (Expression (N), Designated_Type (Typ));
2215 -- Check for view mismatch on Null in instances, for which the
2216 -- view-swapping mechanism has no identifier.
2218 elsif (In_Instance or else In_Inlined_Body)
2219 and then (Nkind (N) = N_Null)
2220 and then Is_Private_Type (Typ)
2221 and then Is_Access_Type (Full_View (Typ))
2223 Resolve (N, Full_View (Typ));
2227 -- Check for an aggregate. Sometimes we can get bogus aggregates
2228 -- from misuse of parentheses, and we are about to complain about
2229 -- the aggregate without even looking inside it.
2231 -- Instead, if we have an aggregate of type Any_Composite, then
2232 -- analyze and resolve the component fields, and then only issue
2233 -- another message if we get no errors doing this (otherwise
2234 -- assume that the errors in the aggregate caused the problem).
2236 elsif Nkind (N) = N_Aggregate
2237 and then Etype (N) = Any_Composite
2239 -- Disable expansion in any case. If there is a type mismatch
2240 -- it may be fatal to try to expand the aggregate. The flag
2241 -- would otherwise be set to false when the error is posted.
2243 Expander_Active := False;
2246 procedure Check_Aggr (Aggr : Node_Id);
2247 -- Check one aggregate, and set Found to True if we have a
2248 -- definite error in any of its elements
2250 procedure Check_Elmt (Aelmt : Node_Id);
2251 -- Check one element of aggregate and set Found to True if
2252 -- we definitely have an error in the element.
2258 procedure Check_Aggr (Aggr : Node_Id) is
2262 if Present (Expressions (Aggr)) then
2263 Elmt := First (Expressions (Aggr));
2264 while Present (Elmt) loop
2270 if Present (Component_Associations (Aggr)) then
2271 Elmt := First (Component_Associations (Aggr));
2272 while Present (Elmt) loop
2274 -- If this is a default-initialized component, then
2275 -- there is nothing to check. The box will be
2276 -- replaced by the appropriate call during late
2279 if not Box_Present (Elmt) then
2280 Check_Elmt (Expression (Elmt));
2292 procedure Check_Elmt (Aelmt : Node_Id) is
2294 -- If we have a nested aggregate, go inside it (to
2295 -- attempt a naked analyze-resolve of the aggregate
2296 -- can cause undesirable cascaded errors). Do not
2297 -- resolve expression if it needs a type from context,
2298 -- as for integer * fixed expression.
2300 if Nkind (Aelmt) = N_Aggregate then
2306 if not Is_Overloaded (Aelmt)
2307 and then Etype (Aelmt) /= Any_Fixed
2312 if Etype (Aelmt) = Any_Type then
2323 -- If an error message was issued already, Found got reset
2324 -- to True, so if it is still False, issue the standard
2325 -- Wrong_Type message.
2328 if Is_Overloaded (N)
2329 and then Nkind (N) = N_Function_Call
2332 Subp_Name : Node_Id;
2334 if Is_Entity_Name (Name (N)) then
2335 Subp_Name := Name (N);
2337 elsif Nkind (Name (N)) = N_Selected_Component then
2339 -- Protected operation: retrieve operation name
2341 Subp_Name := Selector_Name (Name (N));
2343 raise Program_Error;
2346 Error_Msg_Node_2 := Typ;
2347 Error_Msg_NE ("no visible interpretation of&" &
2348 " matches expected type&", N, Subp_Name);
2351 if All_Errors_Mode then
2353 Index : Interp_Index;
2357 Error_Msg_N ("\\possible interpretations:", N);
2359 Get_First_Interp (Name (N), Index, It);
2360 while Present (It.Nam) loop
2361 Error_Msg_Sloc := Sloc (It.Nam);
2362 Error_Msg_Node_2 := It.Nam;
2364 ("\\ type& for & declared#", N, It.Typ);
2365 Get_Next_Interp (Index, It);
2370 Error_Msg_N ("\use -gnatf for details", N);
2373 Wrong_Type (N, Typ);
2381 -- Test if we have more than one interpretation for the context
2383 elsif Ambiguous then
2387 -- Here we have an acceptable interpretation for the context
2390 -- Propagate type information and normalize tree for various
2391 -- predefined operations. If the context only imposes a class of
2392 -- types, rather than a specific type, propagate the actual type
2395 if Typ = Any_Integer
2396 or else Typ = Any_Boolean
2397 or else Typ = Any_Modular
2398 or else Typ = Any_Real
2399 or else Typ = Any_Discrete
2401 Ctx_Type := Expr_Type;
2403 -- Any_Fixed is legal in a real context only if a specific
2404 -- fixed point type is imposed. If Norman Cohen can be
2405 -- confused by this, it deserves a separate message.
2408 and then Expr_Type = Any_Fixed
2410 Error_Msg_N ("illegal context for mixed mode operation", N);
2411 Set_Etype (N, Universal_Real);
2412 Ctx_Type := Universal_Real;
2416 -- A user-defined operator is transformed into a function call at
2417 -- this point, so that further processing knows that operators are
2418 -- really operators (i.e. are predefined operators). User-defined
2419 -- operators that are intrinsic are just renamings of the predefined
2420 -- ones, and need not be turned into calls either, but if they rename
2421 -- a different operator, we must transform the node accordingly.
2422 -- Instantiations of Unchecked_Conversion are intrinsic but are
2423 -- treated as functions, even if given an operator designator.
2425 if Nkind (N) in N_Op
2426 and then Present (Entity (N))
2427 and then Ekind (Entity (N)) /= E_Operator
2430 if not Is_Predefined_Op (Entity (N)) then
2431 Rewrite_Operator_As_Call (N, Entity (N));
2433 elsif Present (Alias (Entity (N)))
2435 Nkind (Parent (Parent (Entity (N)))) =
2436 N_Subprogram_Renaming_Declaration
2438 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2440 -- If the node is rewritten, it will be fully resolved in
2441 -- Rewrite_Renamed_Operator.
2443 if Analyzed (N) then
2449 case N_Subexpr'(Nkind (N)) is
2451 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2453 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2455 when N_And_Then | N_Or_Else
2456 => Resolve_Short_Circuit (N, Ctx_Type);
2458 when N_Attribute_Reference
2459 => Resolve_Attribute (N, Ctx_Type);
2461 when N_Character_Literal
2462 => Resolve_Character_Literal (N, Ctx_Type);
2464 when N_Conditional_Expression
2465 => Resolve_Conditional_Expression (N, Ctx_Type);
2467 when N_Expanded_Name
2468 => Resolve_Entity_Name (N, Ctx_Type);
2470 when N_Extension_Aggregate
2471 => Resolve_Extension_Aggregate (N, Ctx_Type);
2473 when N_Explicit_Dereference
2474 => Resolve_Explicit_Dereference (N, Ctx_Type);
2476 when N_Function_Call
2477 => Resolve_Call (N, Ctx_Type);
2480 => Resolve_Entity_Name (N, Ctx_Type);
2482 when N_Indexed_Component
2483 => Resolve_Indexed_Component (N, Ctx_Type);
2485 when N_Integer_Literal
2486 => Resolve_Integer_Literal (N, Ctx_Type);
2488 when N_Membership_Test
2489 => Resolve_Membership_Op (N, Ctx_Type);
2491 when N_Null => Resolve_Null (N, Ctx_Type);
2493 when N_Op_And | N_Op_Or | N_Op_Xor
2494 => Resolve_Logical_Op (N, Ctx_Type);
2496 when N_Op_Eq | N_Op_Ne
2497 => Resolve_Equality_Op (N, Ctx_Type);
2499 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2500 => Resolve_Comparison_Op (N, Ctx_Type);
2502 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2504 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2505 N_Op_Divide | N_Op_Mod | N_Op_Rem
2507 => Resolve_Arithmetic_Op (N, Ctx_Type);
2509 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2511 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2513 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2514 => Resolve_Unary_Op (N, Ctx_Type);
2516 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2518 when N_Procedure_Call_Statement
2519 => Resolve_Call (N, Ctx_Type);
2521 when N_Operator_Symbol
2522 => Resolve_Operator_Symbol (N, Ctx_Type);
2524 when N_Qualified_Expression
2525 => Resolve_Qualified_Expression (N, Ctx_Type);
2527 when N_Raise_xxx_Error
2528 => Set_Etype (N, Ctx_Type);
2530 when N_Range => Resolve_Range (N, Ctx_Type);
2533 => Resolve_Real_Literal (N, Ctx_Type);
2535 when N_Reference => Resolve_Reference (N, Ctx_Type);
2537 when N_Selected_Component
2538 => Resolve_Selected_Component (N, Ctx_Type);
2540 when N_Slice => Resolve_Slice (N, Ctx_Type);
2542 when N_String_Literal
2543 => Resolve_String_Literal (N, Ctx_Type);
2545 when N_Subprogram_Info
2546 => Resolve_Subprogram_Info (N, Ctx_Type);
2548 when N_Type_Conversion
2549 => Resolve_Type_Conversion (N, Ctx_Type);
2551 when N_Unchecked_Expression =>
2552 Resolve_Unchecked_Expression (N, Ctx_Type);
2554 when N_Unchecked_Type_Conversion =>
2555 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2559 -- If the subexpression was replaced by a non-subexpression, then
2560 -- all we do is to expand it. The only legitimate case we know of
2561 -- is converting procedure call statement to entry call statements,
2562 -- but there may be others, so we are making this test general.
2564 if Nkind (N) not in N_Subexpr then
2565 Debug_A_Exit ("resolving ", N, " (done)");
2570 -- The expression is definitely NOT overloaded at this point, so
2571 -- we reset the Is_Overloaded flag to avoid any confusion when
2572 -- reanalyzing the node.
2574 Set_Is_Overloaded (N, False);
2576 -- Freeze expression type, entity if it is a name, and designated
2577 -- type if it is an allocator (RM 13.14(10,11,13)).
2579 -- Now that the resolution of the type of the node is complete,
2580 -- and we did not detect an error, we can expand this node. We
2581 -- skip the expand call if we are in a default expression, see
2582 -- section "Handling of Default Expressions" in Sem spec.
2584 Debug_A_Exit ("resolving ", N, " (done)");
2586 -- We unconditionally freeze the expression, even if we are in
2587 -- default expression mode (the Freeze_Expression routine tests
2588 -- this flag and only freezes static types if it is set).
2590 Freeze_Expression (N);
2592 -- Now we can do the expansion
2602 -- Version with check(s) suppressed
2604 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2606 if Suppress = All_Checks then
2608 Svg : constant Suppress_Array := Scope_Suppress;
2610 Scope_Suppress := (others => True);
2612 Scope_Suppress := Svg;
2617 Svg : constant Boolean := Scope_Suppress (Suppress);
2619 Scope_Suppress (Suppress) := True;
2621 Scope_Suppress (Suppress) := Svg;
2630 -- Version with implicit type
2632 procedure Resolve (N : Node_Id) is
2634 Resolve (N, Etype (N));
2637 ---------------------
2638 -- Resolve_Actuals --
2639 ---------------------
2641 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2642 Loc : constant Source_Ptr := Sloc (N);
2647 Prev : Node_Id := Empty;
2650 procedure Check_Argument_Order;
2651 -- Performs a check for the case where the actuals are all simple
2652 -- identifiers that correspond to the formal names, but in the wrong
2653 -- order, which is considered suspicious and cause for a warning.
2655 procedure Check_Prefixed_Call;
2656 -- If the original node is an overloaded call in prefix notation,
2657 -- insert an 'Access or a dereference as needed over the first actual.
2658 -- Try_Object_Operation has already verified that there is a valid
2659 -- interpretation, but the form of the actual can only be determined
2660 -- once the primitive operation is identified.
2662 procedure Insert_Default;
2663 -- If the actual is missing in a call, insert in the actuals list
2664 -- an instance of the default expression. The insertion is always
2665 -- a named association.
2667 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2668 -- Check whether T1 and T2, or their full views, are derived from a
2669 -- common type. Used to enforce the restrictions on array conversions
2672 function Static_Concatenation (N : Node_Id) return Boolean;
2673 -- Predicate to determine whether an actual that is a concatenation
2674 -- will be evaluated statically and does not need a transient scope.
2675 -- This must be determined before the actual is resolved and expanded
2676 -- because if needed the transient scope must be introduced earlier.
2678 --------------------------
2679 -- Check_Argument_Order --
2680 --------------------------
2682 procedure Check_Argument_Order is
2684 -- Nothing to do if no parameters, or original node is neither a
2685 -- function call nor a procedure call statement (happens in the
2686 -- operator-transformed-to-function call case), or the call does
2687 -- not come from source, or this warning is off.
2689 if not Warn_On_Parameter_Order
2691 No (Parameter_Associations (N))
2693 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2696 not Comes_From_Source (N)
2702 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2705 -- Nothing to do if only one parameter
2711 -- Here if at least two arguments
2714 Actuals : array (1 .. Nargs) of Node_Id;
2718 Wrong_Order : Boolean := False;
2719 -- Set True if an out of order case is found
2722 -- Collect identifier names of actuals, fail if any actual is
2723 -- not a simple identifier, and record max length of name.
2725 Actual := First (Parameter_Associations (N));
2726 for J in Actuals'Range loop
2727 if Nkind (Actual) /= N_Identifier then
2730 Actuals (J) := Actual;
2735 -- If we got this far, all actuals are identifiers and the list
2736 -- of their names is stored in the Actuals array.
2738 Formal := First_Formal (Nam);
2739 for J in Actuals'Range loop
2741 -- If we ran out of formals, that's odd, probably an error
2742 -- which will be detected elsewhere, but abandon the search.
2748 -- If name matches and is in order OK
2750 if Chars (Formal) = Chars (Actuals (J)) then
2754 -- If no match, see if it is elsewhere in list and if so
2755 -- flag potential wrong order if type is compatible.
2757 for K in Actuals'Range loop
2758 if Chars (Formal) = Chars (Actuals (K))
2760 Has_Compatible_Type (Actuals (K), Etype (Formal))
2762 Wrong_Order := True;
2772 <<Continue>> Next_Formal (Formal);
2775 -- If Formals left over, also probably an error, skip warning
2777 if Present (Formal) then
2781 -- Here we give the warning if something was out of order
2785 ("actuals for this call may be in wrong order?", N);
2789 end Check_Argument_Order;
2791 -------------------------
2792 -- Check_Prefixed_Call --
2793 -------------------------
2795 procedure Check_Prefixed_Call is
2796 Act : constant Node_Id := First_Actual (N);
2797 A_Type : constant Entity_Id := Etype (Act);
2798 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2799 Orig : constant Node_Id := Original_Node (N);
2803 -- Check whether the call is a prefixed call, with or without
2804 -- additional actuals.
2806 if Nkind (Orig) = N_Selected_Component
2808 (Nkind (Orig) = N_Indexed_Component
2809 and then Nkind (Prefix (Orig)) = N_Selected_Component
2810 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2811 and then Is_Entity_Name (Act)
2812 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2814 if Is_Access_Type (A_Type)
2815 and then not Is_Access_Type (F_Type)
2817 -- Introduce dereference on object in prefix
2820 Make_Explicit_Dereference (Sloc (Act),
2821 Prefix => Relocate_Node (Act));
2822 Rewrite (Act, New_A);
2825 elsif Is_Access_Type (F_Type)
2826 and then not Is_Access_Type (A_Type)
2828 -- Introduce an implicit 'Access in prefix
2830 if not Is_Aliased_View (Act) then
2832 ("object in prefixed call to& must be aliased"
2833 & " (RM-2005 4.3.1 (13))",
2838 Make_Attribute_Reference (Loc,
2839 Attribute_Name => Name_Access,
2840 Prefix => Relocate_Node (Act)));
2845 end Check_Prefixed_Call;
2847 --------------------
2848 -- Insert_Default --
2849 --------------------
2851 procedure Insert_Default is
2856 -- Missing argument in call, nothing to insert
2858 if No (Default_Value (F)) then
2862 -- Note that we do a full New_Copy_Tree, so that any associated
2863 -- Itypes are properly copied. This may not be needed any more,
2864 -- but it does no harm as a safety measure! Defaults of a generic
2865 -- formal may be out of bounds of the corresponding actual (see
2866 -- cc1311b) and an additional check may be required.
2871 New_Scope => Current_Scope,
2874 if Is_Concurrent_Type (Scope (Nam))
2875 and then Has_Discriminants (Scope (Nam))
2877 Replace_Actual_Discriminants (N, Actval);
2880 if Is_Overloadable (Nam)
2881 and then Present (Alias (Nam))
2883 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2884 and then not Is_Tagged_Type (Etype (F))
2886 -- If default is a real literal, do not introduce a
2887 -- conversion whose effect may depend on the run-time
2888 -- size of universal real.
2890 if Nkind (Actval) = N_Real_Literal then
2891 Set_Etype (Actval, Base_Type (Etype (F)));
2893 Actval := Unchecked_Convert_To (Etype (F), Actval);
2897 if Is_Scalar_Type (Etype (F)) then
2898 Enable_Range_Check (Actval);
2901 Set_Parent (Actval, N);
2903 -- Resolve aggregates with their base type, to avoid scope
2904 -- anomalies: the subtype was first built in the subprogram
2905 -- declaration, and the current call may be nested.
2907 if Nkind (Actval) = N_Aggregate
2908 and then Has_Discriminants (Etype (Actval))
2910 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2912 Analyze_And_Resolve (Actval, Etype (Actval));
2916 Set_Parent (Actval, N);
2918 -- See note above concerning aggregates
2920 if Nkind (Actval) = N_Aggregate
2921 and then Has_Discriminants (Etype (Actval))
2923 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2925 -- Resolve entities with their own type, which may differ
2926 -- from the type of a reference in a generic context (the
2927 -- view swapping mechanism did not anticipate the re-analysis
2928 -- of default values in calls).
2930 elsif Is_Entity_Name (Actval) then
2931 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2934 Analyze_And_Resolve (Actval, Etype (Actval));
2938 -- If default is a tag indeterminate function call, propagate
2939 -- tag to obtain proper dispatching.
2941 if Is_Controlling_Formal (F)
2942 and then Nkind (Default_Value (F)) = N_Function_Call
2944 Set_Is_Controlling_Actual (Actval);
2949 -- If the default expression raises constraint error, then just
2950 -- silently replace it with an N_Raise_Constraint_Error node,
2951 -- since we already gave the warning on the subprogram spec.
2953 if Raises_Constraint_Error (Actval) then
2955 Make_Raise_Constraint_Error (Loc,
2956 Reason => CE_Range_Check_Failed));
2957 Set_Raises_Constraint_Error (Actval);
2958 Set_Etype (Actval, Etype (F));
2962 Make_Parameter_Association (Loc,
2963 Explicit_Actual_Parameter => Actval,
2964 Selector_Name => Make_Identifier (Loc, Chars (F)));
2966 -- Case of insertion is first named actual
2968 if No (Prev) or else
2969 Nkind (Parent (Prev)) /= N_Parameter_Association
2971 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2972 Set_First_Named_Actual (N, Actval);
2975 if No (Parameter_Associations (N)) then
2976 Set_Parameter_Associations (N, New_List (Assoc));
2978 Append (Assoc, Parameter_Associations (N));
2982 Insert_After (Prev, Assoc);
2985 -- Case of insertion is not first named actual
2988 Set_Next_Named_Actual
2989 (Assoc, Next_Named_Actual (Parent (Prev)));
2990 Set_Next_Named_Actual (Parent (Prev), Actval);
2991 Append (Assoc, Parameter_Associations (N));
2994 Mark_Rewrite_Insertion (Assoc);
2995 Mark_Rewrite_Insertion (Actval);
3004 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3005 FT1 : Entity_Id := T1;
3006 FT2 : Entity_Id := T2;
3009 if Is_Private_Type (T1)
3010 and then Present (Full_View (T1))
3012 FT1 := Full_View (T1);
3015 if Is_Private_Type (T2)
3016 and then Present (Full_View (T2))
3018 FT2 := Full_View (T2);
3021 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3024 --------------------------
3025 -- Static_Concatenation --
3026 --------------------------
3028 function Static_Concatenation (N : Node_Id) return Boolean is
3031 when N_String_Literal =>
3036 -- Concatenation is static when both operands are static
3037 -- and the concatenation operator is a predefined one.
3039 return Scope (Entity (N)) = Standard_Standard
3041 Static_Concatenation (Left_Opnd (N))
3043 Static_Concatenation (Right_Opnd (N));
3046 if Is_Entity_Name (N) then
3048 Ent : constant Entity_Id := Entity (N);
3050 return Ekind (Ent) = E_Constant
3051 and then Present (Constant_Value (Ent))
3053 Is_Static_Expression (Constant_Value (Ent));
3060 end Static_Concatenation;
3062 -- Start of processing for Resolve_Actuals
3065 Check_Argument_Order;
3067 if Present (First_Actual (N)) then
3068 Check_Prefixed_Call;
3071 A := First_Actual (N);
3072 F := First_Formal (Nam);
3073 while Present (F) loop
3074 if No (A) and then Needs_No_Actuals (Nam) then
3077 -- If we have an error in any actual or formal, indicated by a type
3078 -- of Any_Type, then abandon resolution attempt, and set result type
3081 elsif (Present (A) and then Etype (A) = Any_Type)
3082 or else Etype (F) = Any_Type
3084 Set_Etype (N, Any_Type);
3088 -- Case where actual is present
3090 -- If the actual is an entity, generate a reference to it now. We
3091 -- do this before the actual is resolved, because a formal of some
3092 -- protected subprogram, or a task discriminant, will be rewritten
3093 -- during expansion, and the reference to the source entity may
3097 and then Is_Entity_Name (A)
3098 and then Comes_From_Source (N)
3100 Orig_A := Entity (A);
3102 if Present (Orig_A) then
3103 if Is_Formal (Orig_A)
3104 and then Ekind (F) /= E_In_Parameter
3106 Generate_Reference (Orig_A, A, 'm');
3107 elsif not Is_Overloaded (A) then
3108 Generate_Reference (Orig_A, A);
3114 and then (Nkind (Parent (A)) /= N_Parameter_Association
3116 Chars (Selector_Name (Parent (A))) = Chars (F))
3118 -- If style checking mode on, check match of formal name
3121 if Nkind (Parent (A)) = N_Parameter_Association then
3122 Check_Identifier (Selector_Name (Parent (A)), F);
3126 -- If the formal is Out or In_Out, do not resolve and expand the
3127 -- conversion, because it is subsequently expanded into explicit
3128 -- temporaries and assignments. However, the object of the
3129 -- conversion can be resolved. An exception is the case of tagged
3130 -- type conversion with a class-wide actual. In that case we want
3131 -- the tag check to occur and no temporary will be needed (no
3132 -- representation change can occur) and the parameter is passed by
3133 -- reference, so we go ahead and resolve the type conversion.
3134 -- Another exception is the case of reference to component or
3135 -- subcomponent of a bit-packed array, in which case we want to
3136 -- defer expansion to the point the in and out assignments are
3139 if Ekind (F) /= E_In_Parameter
3140 and then Nkind (A) = N_Type_Conversion
3141 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3143 if Ekind (F) = E_In_Out_Parameter
3144 and then Is_Array_Type (Etype (F))
3146 if Has_Aliased_Components (Etype (Expression (A)))
3147 /= Has_Aliased_Components (Etype (F))
3150 -- In a view conversion, the conversion must be legal in
3151 -- both directions, and thus both component types must be
3152 -- aliased, or neither (4.6 (8)).
3154 -- The additional rule 4.6 (24.9.2) seems unduly
3155 -- restrictive: the privacy requirement should not apply
3156 -- to generic types, and should be checked in an
3157 -- instance. ARG query is in order ???
3160 ("both component types in a view conversion must be"
3161 & " aliased, or neither", A);
3164 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3166 if Is_By_Reference_Type (Etype (F))
3167 or else Is_By_Reference_Type (Etype (Expression (A)))
3170 ("view conversion between unrelated by reference " &
3171 "array types not allowed (\'A'I-00246)", A);
3174 Comp_Type : constant Entity_Id :=
3176 (Etype (Expression (A)));
3178 if Comes_From_Source (A)
3179 and then Ada_Version >= Ada_05
3181 ((Is_Private_Type (Comp_Type)
3182 and then not Is_Generic_Type (Comp_Type))
3183 or else Is_Tagged_Type (Comp_Type)
3184 or else Is_Volatile (Comp_Type))
3187 ("component type of a view conversion cannot"
3188 & " be private, tagged, or volatile"
3197 if (Conversion_OK (A)
3198 or else Valid_Conversion (A, Etype (A), Expression (A)))
3199 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3201 Resolve (Expression (A));
3204 -- If the actual is a function call that returns a limited
3205 -- unconstrained object that needs finalization, create a
3206 -- transient scope for it, so that it can receive the proper
3207 -- finalization list.
3209 elsif Nkind (A) = N_Function_Call
3210 and then Is_Limited_Record (Etype (F))
3211 and then not Is_Constrained (Etype (F))
3212 and then Expander_Active
3214 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3216 Establish_Transient_Scope (A, False);
3218 -- A small optimization: if one of the actuals is a concatenation
3219 -- create a block around a procedure call to recover stack space.
3220 -- This alleviates stack usage when several procedure calls in
3221 -- the same statement list use concatenation. We do not perform
3222 -- this wrapping for code statements, where the argument is a
3223 -- static string, and we want to preserve warnings involving
3224 -- sequences of such statements.
3226 elsif Nkind (A) = N_Op_Concat
3227 and then Nkind (N) = N_Procedure_Call_Statement
3228 and then Expander_Active
3230 not (Is_Intrinsic_Subprogram (Nam)
3231 and then Chars (Nam) = Name_Asm)
3232 and then not Static_Concatenation (A)
3234 Establish_Transient_Scope (A, False);
3235 Resolve (A, Etype (F));
3238 if Nkind (A) = N_Type_Conversion
3239 and then Is_Array_Type (Etype (F))
3240 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3242 (Is_Limited_Type (Etype (F))
3243 or else Is_Limited_Type (Etype (Expression (A))))
3246 ("conversion between unrelated limited array types " &
3247 "not allowed (\A\I-00246)", A);
3249 if Is_Limited_Type (Etype (F)) then
3250 Explain_Limited_Type (Etype (F), A);
3253 if Is_Limited_Type (Etype (Expression (A))) then
3254 Explain_Limited_Type (Etype (Expression (A)), A);
3258 -- (Ada 2005: AI-251): If the actual is an allocator whose
3259 -- directly designated type is a class-wide interface, we build
3260 -- an anonymous access type to use it as the type of the
3261 -- allocator. Later, when the subprogram call is expanded, if
3262 -- the interface has a secondary dispatch table the expander
3263 -- will add a type conversion to force the correct displacement
3266 if Nkind (A) = N_Allocator then
3268 DDT : constant Entity_Id :=
3269 Directly_Designated_Type (Base_Type (Etype (F)));
3271 New_Itype : Entity_Id;
3274 if Is_Class_Wide_Type (DDT)
3275 and then Is_Interface (DDT)
3277 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3278 Set_Etype (New_Itype, Etype (A));
3279 Set_Directly_Designated_Type (New_Itype,
3280 Directly_Designated_Type (Etype (A)));
3281 Set_Etype (A, New_Itype);
3284 -- Ada 2005, AI-162:If the actual is an allocator, the
3285 -- innermost enclosing statement is the master of the
3286 -- created object. This needs to be done with expansion
3287 -- enabled only, otherwise the transient scope will not
3288 -- be removed in the expansion of the wrapped construct.
3290 if (Is_Controlled (DDT) or else Has_Task (DDT))
3291 and then Expander_Active
3293 Establish_Transient_Scope (A, False);
3298 -- (Ada 2005): The call may be to a primitive operation of
3299 -- a tagged synchronized type, declared outside of the type.
3300 -- In this case the controlling actual must be converted to
3301 -- its corresponding record type, which is the formal type.
3302 -- The actual may be a subtype, either because of a constraint
3303 -- or because it is a generic actual, so use base type to
3304 -- locate concurrent type.
3306 A_Typ := Base_Type (Etype (A));
3307 F_Typ := Base_Type (Etype (F));
3310 Full_A_Typ : Entity_Id;
3313 if Present (Full_View (A_Typ)) then
3314 Full_A_Typ := Base_Type (Full_View (A_Typ));
3316 Full_A_Typ := A_Typ;
3319 -- Tagged synchronized type (case 1): the actual is a
3322 if Is_Concurrent_Type (A_Typ)
3323 and then Corresponding_Record_Type (A_Typ) = F_Typ
3326 Unchecked_Convert_To
3327 (Corresponding_Record_Type (A_Typ), A));
3328 Resolve (A, Etype (F));
3330 -- Tagged synchronized type (case 2): the formal is a
3333 elsif Ekind (Full_A_Typ) = E_Record_Type
3335 (Corresponding_Concurrent_Type (Full_A_Typ))
3336 and then Is_Concurrent_Type (F_Typ)
3337 and then Present (Corresponding_Record_Type (F_Typ))
3338 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3340 Resolve (A, Corresponding_Record_Type (F_Typ));
3345 Resolve (A, Etype (F));
3353 -- For mode IN, if actual is an entity, and the type of the formal
3354 -- has warnings suppressed, then we reset Never_Set_In_Source for
3355 -- the calling entity. The reason for this is to catch cases like
3356 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3357 -- uses trickery to modify an IN parameter.
3359 if Ekind (F) = E_In_Parameter
3360 and then Is_Entity_Name (A)
3361 and then Present (Entity (A))
3362 and then Ekind (Entity (A)) = E_Variable
3363 and then Has_Warnings_Off (F_Typ)
3365 Set_Never_Set_In_Source (Entity (A), False);
3368 -- Perform error checks for IN and IN OUT parameters
3370 if Ekind (F) /= E_Out_Parameter then
3372 -- Check unset reference. For scalar parameters, it is clearly
3373 -- wrong to pass an uninitialized value as either an IN or
3374 -- IN-OUT parameter. For composites, it is also clearly an
3375 -- error to pass a completely uninitialized value as an IN
3376 -- parameter, but the case of IN OUT is trickier. We prefer
3377 -- not to give a warning here. For example, suppose there is
3378 -- a routine that sets some component of a record to False.
3379 -- It is perfectly reasonable to make this IN-OUT and allow
3380 -- either initialized or uninitialized records to be passed
3383 -- For partially initialized composite values, we also avoid
3384 -- warnings, since it is quite likely that we are passing a
3385 -- partially initialized value and only the initialized fields
3386 -- will in fact be read in the subprogram.
3388 if Is_Scalar_Type (A_Typ)
3389 or else (Ekind (F) = E_In_Parameter
3390 and then not Is_Partially_Initialized_Type (A_Typ))
3392 Check_Unset_Reference (A);
3395 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3396 -- actual to a nested call, since this is case of reading an
3397 -- out parameter, which is not allowed.
3399 if Ada_Version = Ada_83
3400 and then Is_Entity_Name (A)
3401 and then Ekind (Entity (A)) = E_Out_Parameter
3403 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3407 -- Case of OUT or IN OUT parameter
3409 if Ekind (F) /= E_In_Parameter then
3411 -- For an Out parameter, check for useless assignment. Note
3412 -- that we can't set Last_Assignment this early, because we may
3413 -- kill current values in Resolve_Call, and that call would
3414 -- clobber the Last_Assignment field.
3416 -- Note: call Warn_On_Useless_Assignment before doing the check
3417 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3418 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3419 -- reflects the last assignment, not this one!
3421 if Ekind (F) = E_Out_Parameter then
3422 if Warn_On_Modified_As_Out_Parameter (F)
3423 and then Is_Entity_Name (A)
3424 and then Present (Entity (A))
3425 and then Comes_From_Source (N)
3427 Warn_On_Useless_Assignment (Entity (A), A);
3431 -- Validate the form of the actual. Note that the call to
3432 -- Is_OK_Variable_For_Out_Formal generates the required
3433 -- reference in this case.
3435 if not Is_OK_Variable_For_Out_Formal (A) then
3436 Error_Msg_NE ("actual for& must be a variable", A, F);
3439 -- What's the following about???
3441 if Is_Entity_Name (A) then
3442 Kill_Checks (Entity (A));
3448 if Etype (A) = Any_Type then
3449 Set_Etype (N, Any_Type);
3453 -- Apply appropriate range checks for in, out, and in-out
3454 -- parameters. Out and in-out parameters also need a separate
3455 -- check, if there is a type conversion, to make sure the return
3456 -- value meets the constraints of the variable before the
3459 -- Gigi looks at the check flag and uses the appropriate types.
3460 -- For now since one flag is used there is an optimization which
3461 -- might not be done in the In Out case since Gigi does not do
3462 -- any analysis. More thought required about this ???
3464 if Ekind (F) = E_In_Parameter
3465 or else Ekind (F) = E_In_Out_Parameter
3467 if Is_Scalar_Type (Etype (A)) then
3468 Apply_Scalar_Range_Check (A, F_Typ);
3470 elsif Is_Array_Type (Etype (A)) then
3471 Apply_Length_Check (A, F_Typ);
3473 elsif Is_Record_Type (F_Typ)
3474 and then Has_Discriminants (F_Typ)
3475 and then Is_Constrained (F_Typ)
3476 and then (not Is_Derived_Type (F_Typ)
3477 or else Comes_From_Source (Nam))
3479 Apply_Discriminant_Check (A, F_Typ);
3481 elsif Is_Access_Type (F_Typ)
3482 and then Is_Array_Type (Designated_Type (F_Typ))
3483 and then Is_Constrained (Designated_Type (F_Typ))
3485 Apply_Length_Check (A, F_Typ);
3487 elsif Is_Access_Type (F_Typ)
3488 and then Has_Discriminants (Designated_Type (F_Typ))
3489 and then Is_Constrained (Designated_Type (F_Typ))
3491 Apply_Discriminant_Check (A, F_Typ);
3494 Apply_Range_Check (A, F_Typ);
3497 -- Ada 2005 (AI-231)
3499 if Ada_Version >= Ada_05
3500 and then Is_Access_Type (F_Typ)
3501 and then Can_Never_Be_Null (F_Typ)
3502 and then Known_Null (A)
3504 Apply_Compile_Time_Constraint_Error
3506 Msg => "(Ada 2005) null not allowed in "
3507 & "null-excluding formal?",
3508 Reason => CE_Null_Not_Allowed);
3512 if Ekind (F) = E_Out_Parameter
3513 or else Ekind (F) = E_In_Out_Parameter
3515 if Nkind (A) = N_Type_Conversion then
3516 if Is_Scalar_Type (A_Typ) then
3517 Apply_Scalar_Range_Check
3518 (Expression (A), Etype (Expression (A)), A_Typ);
3521 (Expression (A), Etype (Expression (A)), A_Typ);
3525 if Is_Scalar_Type (F_Typ) then
3526 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3528 elsif Is_Array_Type (F_Typ)
3529 and then Ekind (F) = E_Out_Parameter
3531 Apply_Length_Check (A, F_Typ);
3534 Apply_Range_Check (A, A_Typ, F_Typ);
3539 -- An actual associated with an access parameter is implicitly
3540 -- converted to the anonymous access type of the formal and must
3541 -- satisfy the legality checks for access conversions.
3543 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3544 if not Valid_Conversion (A, F_Typ, A) then
3546 ("invalid implicit conversion for access parameter", A);
3550 -- Check bad case of atomic/volatile argument (RM C.6(12))
3552 if Is_By_Reference_Type (Etype (F))
3553 and then Comes_From_Source (N)
3555 if Is_Atomic_Object (A)
3556 and then not Is_Atomic (Etype (F))
3559 ("cannot pass atomic argument to non-atomic formal",
3562 elsif Is_Volatile_Object (A)
3563 and then not Is_Volatile (Etype (F))
3566 ("cannot pass volatile argument to non-volatile formal",
3571 -- Check that subprograms don't have improper controlling
3572 -- arguments (RM 3.9.2 (9)).
3574 -- A primitive operation may have an access parameter of an
3575 -- incomplete tagged type, but a dispatching call is illegal
3576 -- if the type is still incomplete.
3578 if Is_Controlling_Formal (F) then
3579 Set_Is_Controlling_Actual (A);
3581 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3583 Desig : constant Entity_Id := Designated_Type (Etype (F));
3585 if Ekind (Desig) = E_Incomplete_Type
3586 and then No (Full_View (Desig))
3587 and then No (Non_Limited_View (Desig))
3590 ("premature use of incomplete type& " &
3591 "in dispatching call", A, Desig);
3596 elsif Nkind (A) = N_Explicit_Dereference then
3597 Validate_Remote_Access_To_Class_Wide_Type (A);
3600 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3601 and then not Is_Class_Wide_Type (F_Typ)
3602 and then not Is_Controlling_Formal (F)
3604 Error_Msg_N ("class-wide argument not allowed here!", A);
3606 if Is_Subprogram (Nam)
3607 and then Comes_From_Source (Nam)
3609 Error_Msg_Node_2 := F_Typ;
3611 ("& is not a dispatching operation of &!", A, Nam);
3614 elsif Is_Access_Type (A_Typ)
3615 and then Is_Access_Type (F_Typ)
3616 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3617 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3618 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3619 or else (Nkind (A) = N_Attribute_Reference
3621 Is_Class_Wide_Type (Etype (Prefix (A)))))
3622 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3623 and then not Is_Controlling_Formal (F)
3626 ("access to class-wide argument not allowed here!", A);
3628 if Is_Subprogram (Nam)
3629 and then Comes_From_Source (Nam)
3631 Error_Msg_Node_2 := Designated_Type (F_Typ);
3633 ("& is not a dispatching operation of &!", A, Nam);
3639 -- If it is a named association, treat the selector_name as
3640 -- a proper identifier, and mark the corresponding entity.
3642 if Nkind (Parent (A)) = N_Parameter_Association then
3643 Set_Entity (Selector_Name (Parent (A)), F);
3644 Generate_Reference (F, Selector_Name (Parent (A)));
3645 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3646 Generate_Reference (F_Typ, N, ' ');
3651 if Ekind (F) /= E_Out_Parameter then
3652 Check_Unset_Reference (A);
3657 -- Case where actual is not present
3665 end Resolve_Actuals;
3667 -----------------------
3668 -- Resolve_Allocator --
3669 -----------------------
3671 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3672 E : constant Node_Id := Expression (N);
3674 Discrim : Entity_Id;
3677 Assoc : Node_Id := Empty;
3680 procedure Check_Allocator_Discrim_Accessibility
3681 (Disc_Exp : Node_Id;
3682 Alloc_Typ : Entity_Id);
3683 -- Check that accessibility level associated with an access discriminant
3684 -- initialized in an allocator by the expression Disc_Exp is not deeper
3685 -- than the level of the allocator type Alloc_Typ. An error message is
3686 -- issued if this condition is violated. Specialized checks are done for
3687 -- the cases of a constraint expression which is an access attribute or
3688 -- an access discriminant.
3690 function In_Dispatching_Context return Boolean;
3691 -- If the allocator is an actual in a call, it is allowed to be class-
3692 -- wide when the context is not because it is a controlling actual.
3694 procedure Propagate_Coextensions (Root : Node_Id);
3695 -- Propagate all nested coextensions which are located one nesting
3696 -- level down the tree to the node Root. Example:
3699 -- Level_1_Coextension
3700 -- Level_2_Coextension
3702 -- The algorithm is paired with delay actions done by the Expander. In
3703 -- the above example, assume all coextensions are controlled types.
3704 -- The cycle of analysis, resolution and expansion will yield:
3706 -- 1) Analyze Top_Record
3707 -- 2) Analyze Level_1_Coextension
3708 -- 3) Analyze Level_2_Coextension
3709 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3711 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3712 -- generated to capture the allocated object. Temp_1 is attached
3713 -- to the coextension chain of Level_2_Coextension.
3714 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3715 -- coextension. A forward tree traversal is performed which finds
3716 -- Level_2_Coextension's list and copies its contents into its
3718 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3719 -- generated to capture the allocated object. Temp_2 is attached
3720 -- to the coextension chain of Level_1_Coextension. Currently, the
3721 -- contents of the list are [Temp_2, Temp_1].
3722 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3723 -- finds Level_1_Coextension's list and copies its contents into
3725 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3726 -- Temp_2 and attach them to Top_Record's finalization list.
3728 -------------------------------------------
3729 -- Check_Allocator_Discrim_Accessibility --
3730 -------------------------------------------
3732 procedure Check_Allocator_Discrim_Accessibility
3733 (Disc_Exp : Node_Id;
3734 Alloc_Typ : Entity_Id)
3737 if Type_Access_Level (Etype (Disc_Exp)) >
3738 Type_Access_Level (Alloc_Typ)
3741 ("operand type has deeper level than allocator type", Disc_Exp);
3743 -- When the expression is an Access attribute the level of the prefix
3744 -- object must not be deeper than that of the allocator's type.
3746 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3747 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3749 and then Object_Access_Level (Prefix (Disc_Exp))
3750 > Type_Access_Level (Alloc_Typ)
3753 ("prefix of attribute has deeper level than allocator type",
3756 -- When the expression is an access discriminant the check is against
3757 -- the level of the prefix object.
3759 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3760 and then Nkind (Disc_Exp) = N_Selected_Component
3761 and then Object_Access_Level (Prefix (Disc_Exp))
3762 > Type_Access_Level (Alloc_Typ)
3765 ("access discriminant has deeper level than allocator type",
3768 -- All other cases are legal
3773 end Check_Allocator_Discrim_Accessibility;
3775 ----------------------------
3776 -- In_Dispatching_Context --
3777 ----------------------------
3779 function In_Dispatching_Context return Boolean is
3780 Par : constant Node_Id := Parent (N);
3782 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3783 and then Is_Entity_Name (Name (Par))
3784 and then Is_Dispatching_Operation (Entity (Name (Par)));
3785 end In_Dispatching_Context;
3787 ----------------------------
3788 -- Propagate_Coextensions --
3789 ----------------------------
3791 procedure Propagate_Coextensions (Root : Node_Id) is
3793 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3794 -- Copy the contents of list From into list To, preserving the
3795 -- order of elements.
3797 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3798 -- Recognize an allocator or a rewritten allocator node and add it
3799 -- along with its nested coextensions to the list of Root.
3805 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3806 From_Elmt : Elmt_Id;
3808 From_Elmt := First_Elmt (From);
3809 while Present (From_Elmt) loop
3810 Append_Elmt (Node (From_Elmt), To);
3811 Next_Elmt (From_Elmt);
3815 -----------------------
3816 -- Process_Allocator --
3817 -----------------------
3819 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3820 Orig_Nod : Node_Id := Nod;
3823 -- This is a possible rewritten subtype indication allocator. Any
3824 -- nested coextensions will appear as discriminant constraints.
3826 if Nkind (Nod) = N_Identifier
3827 and then Present (Original_Node (Nod))
3828 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3832 Discr_Elmt : Elmt_Id;
3835 if Is_Record_Type (Entity (Nod)) then
3837 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3838 while Present (Discr_Elmt) loop
3839 Discr := Node (Discr_Elmt);
3841 if Nkind (Discr) = N_Identifier
3842 and then Present (Original_Node (Discr))
3843 and then Nkind (Original_Node (Discr)) = N_Allocator
3844 and then Present (Coextensions (
3845 Original_Node (Discr)))
3847 if No (Coextensions (Root)) then
3848 Set_Coextensions (Root, New_Elmt_List);
3852 (From => Coextensions (Original_Node (Discr)),
3853 To => Coextensions (Root));
3856 Next_Elmt (Discr_Elmt);
3859 -- There is no need to continue the traversal of this
3860 -- subtree since all the information has already been
3867 -- Case of either a stand alone allocator or a rewritten allocator
3868 -- with an aggregate.
3871 if Present (Original_Node (Nod)) then
3872 Orig_Nod := Original_Node (Nod);
3875 if Nkind (Orig_Nod) = N_Allocator then
3877 -- Propagate the list of nested coextensions to the Root
3878 -- allocator. This is done through list copy since a single
3879 -- allocator may have multiple coextensions. Do not touch
3880 -- coextensions roots.
3882 if not Is_Coextension_Root (Orig_Nod)
3883 and then Present (Coextensions (Orig_Nod))
3885 if No (Coextensions (Root)) then
3886 Set_Coextensions (Root, New_Elmt_List);
3890 (From => Coextensions (Orig_Nod),
3891 To => Coextensions (Root));
3894 -- There is no need to continue the traversal of this
3895 -- subtree since all the information has already been
3902 -- Keep on traversing, looking for the next allocator
3905 end Process_Allocator;
3907 procedure Process_Allocators is
3908 new Traverse_Proc (Process_Allocator);
3910 -- Start of processing for Propagate_Coextensions
3913 Process_Allocators (Expression (Root));
3914 end Propagate_Coextensions;
3916 -- Start of processing for Resolve_Allocator
3919 -- Replace general access with specific type
3921 if Ekind (Etype (N)) = E_Allocator_Type then
3922 Set_Etype (N, Base_Type (Typ));
3925 if Is_Abstract_Type (Typ) then
3926 Error_Msg_N ("type of allocator cannot be abstract", N);
3929 -- For qualified expression, resolve the expression using the
3930 -- given subtype (nothing to do for type mark, subtype indication)
3932 if Nkind (E) = N_Qualified_Expression then
3933 if Is_Class_Wide_Type (Etype (E))
3934 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3935 and then not In_Dispatching_Context
3938 ("class-wide allocator not allowed for this access type", N);
3941 Resolve (Expression (E), Etype (E));
3942 Check_Unset_Reference (Expression (E));
3944 -- A qualified expression requires an exact match of the type,
3945 -- class-wide matching is not allowed.
3947 if (Is_Class_Wide_Type (Etype (Expression (E)))
3948 or else Is_Class_Wide_Type (Etype (E)))
3949 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3951 Wrong_Type (Expression (E), Etype (E));
3954 -- A special accessibility check is needed for allocators that
3955 -- constrain access discriminants. The level of the type of the
3956 -- expression used to constrain an access discriminant cannot be
3957 -- deeper than the type of the allocator (in contrast to access
3958 -- parameters, where the level of the actual can be arbitrary).
3960 -- We can't use Valid_Conversion to perform this check because
3961 -- in general the type of the allocator is unrelated to the type
3962 -- of the access discriminant.
3964 if Ekind (Typ) /= E_Anonymous_Access_Type
3965 or else Is_Local_Anonymous_Access (Typ)
3967 Subtyp := Entity (Subtype_Mark (E));
3969 Aggr := Original_Node (Expression (E));
3971 if Has_Discriminants (Subtyp)
3972 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
3974 Discrim := First_Discriminant (Base_Type (Subtyp));
3976 -- Get the first component expression of the aggregate
3978 if Present (Expressions (Aggr)) then
3979 Disc_Exp := First (Expressions (Aggr));
3981 elsif Present (Component_Associations (Aggr)) then
3982 Assoc := First (Component_Associations (Aggr));
3984 if Present (Assoc) then
3985 Disc_Exp := Expression (Assoc);
3994 while Present (Discrim) and then Present (Disc_Exp) loop
3995 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3996 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
3999 Next_Discriminant (Discrim);
4001 if Present (Discrim) then
4002 if Present (Assoc) then
4004 Disc_Exp := Expression (Assoc);
4006 elsif Present (Next (Disc_Exp)) then
4010 Assoc := First (Component_Associations (Aggr));
4012 if Present (Assoc) then
4013 Disc_Exp := Expression (Assoc);
4023 -- For a subtype mark or subtype indication, freeze the subtype
4026 Freeze_Expression (E);
4028 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4030 ("initialization required for access-to-constant allocator", N);
4033 -- A special accessibility check is needed for allocators that
4034 -- constrain access discriminants. The level of the type of the
4035 -- expression used to constrain an access discriminant cannot be
4036 -- deeper than the type of the allocator (in contrast to access
4037 -- parameters, where the level of the actual can be arbitrary).
4038 -- We can't use Valid_Conversion to perform this check because
4039 -- in general the type of the allocator is unrelated to the type
4040 -- of the access discriminant.
4042 if Nkind (Original_Node (E)) = N_Subtype_Indication
4043 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4044 or else Is_Local_Anonymous_Access (Typ))
4046 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4048 if Has_Discriminants (Subtyp) then
4049 Discrim := First_Discriminant (Base_Type (Subtyp));
4050 Constr := First (Constraints (Constraint (Original_Node (E))));
4051 while Present (Discrim) and then Present (Constr) loop
4052 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4053 if Nkind (Constr) = N_Discriminant_Association then
4054 Disc_Exp := Original_Node (Expression (Constr));
4056 Disc_Exp := Original_Node (Constr);
4059 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4062 Next_Discriminant (Discrim);
4069 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4070 -- check that the level of the type of the created object is not deeper
4071 -- than the level of the allocator's access type, since extensions can
4072 -- now occur at deeper levels than their ancestor types. This is a
4073 -- static accessibility level check; a run-time check is also needed in
4074 -- the case of an initialized allocator with a class-wide argument (see
4075 -- Expand_Allocator_Expression).
4077 if Ada_Version >= Ada_05
4078 and then Is_Class_Wide_Type (Designated_Type (Typ))
4081 Exp_Typ : Entity_Id;
4084 if Nkind (E) = N_Qualified_Expression then
4085 Exp_Typ := Etype (E);
4086 elsif Nkind (E) = N_Subtype_Indication then
4087 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4089 Exp_Typ := Entity (E);
4092 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4093 if In_Instance_Body then
4094 Error_Msg_N ("?type in allocator has deeper level than" &
4095 " designated class-wide type", E);
4096 Error_Msg_N ("\?Program_Error will be raised at run time",
4099 Make_Raise_Program_Error (Sloc (N),
4100 Reason => PE_Accessibility_Check_Failed));
4103 -- Do not apply Ada 2005 accessibility checks on a class-wide
4104 -- allocator if the type given in the allocator is a formal
4105 -- type. A run-time check will be performed in the instance.
4107 elsif not Is_Generic_Type (Exp_Typ) then
4108 Error_Msg_N ("type in allocator has deeper level than" &
4109 " designated class-wide type", E);
4115 -- Check for allocation from an empty storage pool
4117 if No_Pool_Assigned (Typ) then
4119 Loc : constant Source_Ptr := Sloc (N);
4121 Error_Msg_N ("?allocation from empty storage pool!", N);
4122 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4124 Make_Raise_Storage_Error (Loc,
4125 Reason => SE_Empty_Storage_Pool));
4128 -- If the context is an unchecked conversion, as may happen within
4129 -- an inlined subprogram, the allocator is being resolved with its
4130 -- own anonymous type. In that case, if the target type has a specific
4131 -- storage pool, it must be inherited explicitly by the allocator type.
4133 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4134 and then No (Associated_Storage_Pool (Typ))
4136 Set_Associated_Storage_Pool
4137 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4140 -- An erroneous allocator may be rewritten as a raise Program_Error
4143 if Nkind (N) = N_Allocator then
4145 -- An anonymous access discriminant is the definition of a
4148 if Ekind (Typ) = E_Anonymous_Access_Type
4149 and then Nkind (Associated_Node_For_Itype (Typ)) =
4150 N_Discriminant_Specification
4152 -- Avoid marking an allocator as a dynamic coextension if it is
4153 -- within a static construct.
4155 if not Is_Static_Coextension (N) then
4156 Set_Is_Dynamic_Coextension (N);
4159 -- Cleanup for potential static coextensions
4162 Set_Is_Dynamic_Coextension (N, False);
4163 Set_Is_Static_Coextension (N, False);
4166 -- There is no need to propagate any nested coextensions if they
4167 -- are marked as static since they will be rewritten on the spot.
4169 if not Is_Static_Coextension (N) then
4170 Propagate_Coextensions (N);
4173 end Resolve_Allocator;
4175 ---------------------------
4176 -- Resolve_Arithmetic_Op --
4177 ---------------------------
4179 -- Used for resolving all arithmetic operators except exponentiation
4181 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4182 L : constant Node_Id := Left_Opnd (N);
4183 R : constant Node_Id := Right_Opnd (N);
4184 TL : constant Entity_Id := Base_Type (Etype (L));
4185 TR : constant Entity_Id := Base_Type (Etype (R));
4189 B_Typ : constant Entity_Id := Base_Type (Typ);
4190 -- We do the resolution using the base type, because intermediate values
4191 -- in expressions always are of the base type, not a subtype of it.
4193 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4194 -- Returns True if N is in a context that expects "any real type"
4196 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4197 -- Return True iff given type is Integer or universal real/integer
4199 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4200 -- Choose type of integer literal in fixed-point operation to conform
4201 -- to available fixed-point type. T is the type of the other operand,
4202 -- which is needed to determine the expected type of N.
4204 procedure Set_Operand_Type (N : Node_Id);
4205 -- Set operand type to T if universal
4207 -------------------------------
4208 -- Expected_Type_Is_Any_Real --
4209 -------------------------------
4211 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4213 -- N is the expression after "delta" in a fixed_point_definition;
4216 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4217 N_Decimal_Fixed_Point_Definition,
4219 -- N is one of the bounds in a real_range_specification;
4222 N_Real_Range_Specification,
4224 -- N is the expression of a delta_constraint;
4227 N_Delta_Constraint);
4228 end Expected_Type_Is_Any_Real;
4230 -----------------------------
4231 -- Is_Integer_Or_Universal --
4232 -----------------------------
4234 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4236 Index : Interp_Index;
4240 if not Is_Overloaded (N) then
4242 return Base_Type (T) = Base_Type (Standard_Integer)
4243 or else T = Universal_Integer
4244 or else T = Universal_Real;
4246 Get_First_Interp (N, Index, It);
4247 while Present (It.Typ) loop
4248 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4249 or else It.Typ = Universal_Integer
4250 or else It.Typ = Universal_Real
4255 Get_Next_Interp (Index, It);
4260 end Is_Integer_Or_Universal;
4262 ----------------------------
4263 -- Set_Mixed_Mode_Operand --
4264 ----------------------------
4266 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4267 Index : Interp_Index;
4271 if Universal_Interpretation (N) = Universal_Integer then
4273 -- A universal integer literal is resolved as standard integer
4274 -- except in the case of a fixed-point result, where we leave it
4275 -- as universal (to be handled by Exp_Fixd later on)
4277 if Is_Fixed_Point_Type (T) then
4278 Resolve (N, Universal_Integer);
4280 Resolve (N, Standard_Integer);
4283 elsif Universal_Interpretation (N) = Universal_Real
4284 and then (T = Base_Type (Standard_Integer)
4285 or else T = Universal_Integer
4286 or else T = Universal_Real)
4288 -- A universal real can appear in a fixed-type context. We resolve
4289 -- the literal with that context, even though this might raise an
4290 -- exception prematurely (the other operand may be zero).
4294 elsif Etype (N) = Base_Type (Standard_Integer)
4295 and then T = Universal_Real
4296 and then Is_Overloaded (N)
4298 -- Integer arg in mixed-mode operation. Resolve with universal
4299 -- type, in case preference rule must be applied.
4301 Resolve (N, Universal_Integer);
4304 and then B_Typ /= Universal_Fixed
4306 -- Not a mixed-mode operation, resolve with context
4310 elsif Etype (N) = Any_Fixed then
4312 -- N may itself be a mixed-mode operation, so use context type
4316 elsif Is_Fixed_Point_Type (T)
4317 and then B_Typ = Universal_Fixed
4318 and then Is_Overloaded (N)
4320 -- Must be (fixed * fixed) operation, operand must have one
4321 -- compatible interpretation.
4323 Resolve (N, Any_Fixed);
4325 elsif Is_Fixed_Point_Type (B_Typ)
4326 and then (T = Universal_Real
4327 or else Is_Fixed_Point_Type (T))
4328 and then Is_Overloaded (N)
4330 -- C * F(X) in a fixed context, where C is a real literal or a
4331 -- fixed-point expression. F must have either a fixed type
4332 -- interpretation or an integer interpretation, but not both.
4334 Get_First_Interp (N, Index, It);
4335 while Present (It.Typ) loop
4336 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4338 if Analyzed (N) then
4339 Error_Msg_N ("ambiguous operand in fixed operation", N);
4341 Resolve (N, Standard_Integer);
4344 elsif Is_Fixed_Point_Type (It.Typ) then
4346 if Analyzed (N) then
4347 Error_Msg_N ("ambiguous operand in fixed operation", N);
4349 Resolve (N, It.Typ);
4353 Get_Next_Interp (Index, It);
4356 -- Reanalyze the literal with the fixed type of the context. If
4357 -- context is Universal_Fixed, we are within a conversion, leave
4358 -- the literal as a universal real because there is no usable
4359 -- fixed type, and the target of the conversion plays no role in
4373 if B_Typ = Universal_Fixed
4374 and then Nkind (Op2) = N_Real_Literal
4376 T2 := Universal_Real;
4381 Set_Analyzed (Op2, False);
4388 end Set_Mixed_Mode_Operand;
4390 ----------------------
4391 -- Set_Operand_Type --
4392 ----------------------
4394 procedure Set_Operand_Type (N : Node_Id) is
4396 if Etype (N) = Universal_Integer
4397 or else Etype (N) = Universal_Real
4401 end Set_Operand_Type;
4403 -- Start of processing for Resolve_Arithmetic_Op
4406 if Comes_From_Source (N)
4407 and then Ekind (Entity (N)) = E_Function
4408 and then Is_Imported (Entity (N))
4409 and then Is_Intrinsic_Subprogram (Entity (N))
4411 Resolve_Intrinsic_Operator (N, Typ);
4414 -- Special-case for mixed-mode universal expressions or fixed point
4415 -- type operation: each argument is resolved separately. The same
4416 -- treatment is required if one of the operands of a fixed point
4417 -- operation is universal real, since in this case we don't do a
4418 -- conversion to a specific fixed-point type (instead the expander
4419 -- takes care of the case).
4421 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4422 and then Present (Universal_Interpretation (L))
4423 and then Present (Universal_Interpretation (R))
4425 Resolve (L, Universal_Interpretation (L));
4426 Resolve (R, Universal_Interpretation (R));
4427 Set_Etype (N, B_Typ);
4429 elsif (B_Typ = Universal_Real
4430 or else Etype (N) = Universal_Fixed
4431 or else (Etype (N) = Any_Fixed
4432 and then Is_Fixed_Point_Type (B_Typ))
4433 or else (Is_Fixed_Point_Type (B_Typ)
4434 and then (Is_Integer_Or_Universal (L)
4436 Is_Integer_Or_Universal (R))))
4437 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4439 if TL = Universal_Integer or else TR = Universal_Integer then
4440 Check_For_Visible_Operator (N, B_Typ);
4443 -- If context is a fixed type and one operand is integer, the
4444 -- other is resolved with the type of the context.
4446 if Is_Fixed_Point_Type (B_Typ)
4447 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4448 or else TL = Universal_Integer)
4453 elsif Is_Fixed_Point_Type (B_Typ)
4454 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4455 or else TR = Universal_Integer)
4461 Set_Mixed_Mode_Operand (L, TR);
4462 Set_Mixed_Mode_Operand (R, TL);
4465 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4466 -- multiplying operators from being used when the expected type is
4467 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4468 -- some cases where the expected type is actually Any_Real;
4469 -- Expected_Type_Is_Any_Real takes care of that case.
4471 if Etype (N) = Universal_Fixed
4472 or else Etype (N) = Any_Fixed
4474 if B_Typ = Universal_Fixed
4475 and then not Expected_Type_Is_Any_Real (N)
4476 and then not Nkind_In (Parent (N), N_Type_Conversion,
4477 N_Unchecked_Type_Conversion)
4479 Error_Msg_N ("type cannot be determined from context!", N);
4480 Error_Msg_N ("\explicit conversion to result type required", N);
4482 Set_Etype (L, Any_Type);
4483 Set_Etype (R, Any_Type);
4486 if Ada_Version = Ada_83
4487 and then Etype (N) = Universal_Fixed
4489 Nkind_In (Parent (N), N_Type_Conversion,
4490 N_Unchecked_Type_Conversion)
4493 ("(Ada 83) fixed-point operation "
4494 & "needs explicit conversion", N);
4497 -- The expected type is "any real type" in contexts like
4498 -- type T is delta <universal_fixed-expression> ...
4499 -- in which case we need to set the type to Universal_Real
4500 -- so that static expression evaluation will work properly.
4502 if Expected_Type_Is_Any_Real (N) then
4503 Set_Etype (N, Universal_Real);
4505 Set_Etype (N, B_Typ);
4509 elsif Is_Fixed_Point_Type (B_Typ)
4510 and then (Is_Integer_Or_Universal (L)
4511 or else Nkind (L) = N_Real_Literal
4512 or else Nkind (R) = N_Real_Literal
4513 or else Is_Integer_Or_Universal (R))
4515 Set_Etype (N, B_Typ);
4517 elsif Etype (N) = Any_Fixed then
4519 -- If no previous errors, this is only possible if one operand
4520 -- is overloaded and the context is universal. Resolve as such.
4522 Set_Etype (N, B_Typ);
4526 if (TL = Universal_Integer or else TL = Universal_Real)
4528 (TR = Universal_Integer or else TR = Universal_Real)
4530 Check_For_Visible_Operator (N, B_Typ);
4533 -- If the context is Universal_Fixed and the operands are also
4534 -- universal fixed, this is an error, unless there is only one
4535 -- applicable fixed_point type (usually duration).
4537 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4538 T := Unique_Fixed_Point_Type (N);
4540 if T = Any_Type then
4553 -- If one of the arguments was resolved to a non-universal type.
4554 -- label the result of the operation itself with the same type.
4555 -- Do the same for the universal argument, if any.
4557 T := Intersect_Types (L, R);
4558 Set_Etype (N, Base_Type (T));
4559 Set_Operand_Type (L);
4560 Set_Operand_Type (R);
4563 Generate_Operator_Reference (N, Typ);
4564 Eval_Arithmetic_Op (N);
4566 -- Set overflow and division checking bit. Much cleverer code needed
4567 -- here eventually and perhaps the Resolve routines should be separated
4568 -- for the various arithmetic operations, since they will need
4569 -- different processing. ???
4571 if Nkind (N) in N_Op then
4572 if not Overflow_Checks_Suppressed (Etype (N)) then
4573 Enable_Overflow_Check (N);
4576 -- Give warning if explicit division by zero
4578 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4579 and then not Division_Checks_Suppressed (Etype (N))
4581 Rop := Right_Opnd (N);
4583 if Compile_Time_Known_Value (Rop)
4584 and then ((Is_Integer_Type (Etype (Rop))
4585 and then Expr_Value (Rop) = Uint_0)
4587 (Is_Real_Type (Etype (Rop))
4588 and then Expr_Value_R (Rop) = Ureal_0))
4590 -- Specialize the warning message according to the operation
4594 Apply_Compile_Time_Constraint_Error
4595 (N, "division by zero?", CE_Divide_By_Zero,
4596 Loc => Sloc (Right_Opnd (N)));
4599 Apply_Compile_Time_Constraint_Error
4600 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4601 Loc => Sloc (Right_Opnd (N)));
4604 Apply_Compile_Time_Constraint_Error
4605 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4606 Loc => Sloc (Right_Opnd (N)));
4608 -- Division by zero can only happen with division, rem,
4609 -- and mod operations.
4612 raise Program_Error;
4615 -- Otherwise just set the flag to check at run time
4618 Activate_Division_Check (N);
4622 -- If Restriction No_Implicit_Conditionals is active, then it is
4623 -- violated if either operand can be negative for mod, or for rem
4624 -- if both operands can be negative.
4626 if Restrictions.Set (No_Implicit_Conditionals)
4627 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4636 -- Set if corresponding operand might be negative
4639 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4640 LNeg := (not OK) or else Lo < 0;
4642 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4643 RNeg := (not OK) or else Lo < 0;
4645 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4647 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4649 Check_Restriction (No_Implicit_Conditionals, N);
4655 Check_Unset_Reference (L);
4656 Check_Unset_Reference (R);
4657 end Resolve_Arithmetic_Op;
4663 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4664 Loc : constant Source_Ptr := Sloc (N);
4665 Subp : constant Node_Id := Name (N);
4674 -- The context imposes a unique interpretation with type Typ on a
4675 -- procedure or function call. Find the entity of the subprogram that
4676 -- yields the expected type, and propagate the corresponding formal
4677 -- constraints on the actuals. The caller has established that an
4678 -- interpretation exists, and emitted an error if not unique.
4680 -- First deal with the case of a call to an access-to-subprogram,
4681 -- dereference made explicit in Analyze_Call.
4683 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4684 if not Is_Overloaded (Subp) then
4685 Nam := Etype (Subp);
4688 -- Find the interpretation whose type (a subprogram type) has a
4689 -- return type that is compatible with the context. Analysis of
4690 -- the node has established that one exists.
4694 Get_First_Interp (Subp, I, It);
4695 while Present (It.Typ) loop
4696 if Covers (Typ, Etype (It.Typ)) then
4701 Get_Next_Interp (I, It);
4705 raise Program_Error;
4709 -- If the prefix is not an entity, then resolve it
4711 if not Is_Entity_Name (Subp) then
4712 Resolve (Subp, Nam);
4715 -- For an indirect call, we always invalidate checks, since we do not
4716 -- know whether the subprogram is local or global. Yes we could do
4717 -- better here, e.g. by knowing that there are no local subprograms,
4718 -- but it does not seem worth the effort. Similarly, we kill all
4719 -- knowledge of current constant values.
4721 Kill_Current_Values;
4723 -- If this is a procedure call which is really an entry call, do
4724 -- the conversion of the procedure call to an entry call. Protected
4725 -- operations use the same circuitry because the name in the call
4726 -- can be an arbitrary expression with special resolution rules.
4728 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4729 or else (Is_Entity_Name (Subp)
4730 and then Ekind (Entity (Subp)) = E_Entry)
4732 Resolve_Entry_Call (N, Typ);
4733 Check_Elab_Call (N);
4735 -- Kill checks and constant values, as above for indirect case
4736 -- Who knows what happens when another task is activated?
4738 Kill_Current_Values;
4741 -- Normal subprogram call with name established in Resolve
4743 elsif not (Is_Type (Entity (Subp))) then
4744 Nam := Entity (Subp);
4745 Set_Entity_With_Style_Check (Subp, Nam);
4747 -- Otherwise we must have the case of an overloaded call
4750 pragma Assert (Is_Overloaded (Subp));
4752 -- Initialize Nam to prevent warning (we know it will be assigned
4753 -- in the loop below, but the compiler does not know that).
4757 Get_First_Interp (Subp, I, It);
4758 while Present (It.Typ) loop
4759 if Covers (Typ, It.Typ) then
4761 Set_Entity_With_Style_Check (Subp, Nam);
4765 Get_Next_Interp (I, It);
4769 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4770 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4771 and then Nkind (Subp) /= N_Explicit_Dereference
4772 and then Present (Parameter_Associations (N))
4774 -- The prefix is a parameterless function call that returns an access
4775 -- to subprogram. If parameters are present in the current call, add
4776 -- add an explicit dereference. We use the base type here because
4777 -- within an instance these may be subtypes.
4779 -- The dereference is added either in Analyze_Call or here. Should
4780 -- be consolidated ???
4782 Set_Is_Overloaded (Subp, False);
4783 Set_Etype (Subp, Etype (Nam));
4784 Insert_Explicit_Dereference (Subp);
4785 Nam := Designated_Type (Etype (Nam));
4786 Resolve (Subp, Nam);
4789 -- Check that a call to Current_Task does not occur in an entry body
4791 if Is_RTE (Nam, RE_Current_Task) then
4800 -- Exclude calls that occur within the default of a formal
4801 -- parameter of the entry, since those are evaluated outside
4804 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4806 if Nkind (P) = N_Entry_Body
4807 or else (Nkind (P) = N_Subprogram_Body
4808 and then Is_Entry_Barrier_Function (P))
4812 ("?& should not be used in entry body (RM C.7(17))",
4815 ("\Program_Error will be raised at run time?", N, Nam);
4817 Make_Raise_Program_Error (Loc,
4818 Reason => PE_Current_Task_In_Entry_Body));
4819 Set_Etype (N, Rtype);
4826 -- Check that a procedure call does not occur in the context of the
4827 -- entry call statement of a conditional or timed entry call. Note that
4828 -- the case of a call to a subprogram renaming of an entry will also be
4829 -- rejected. The test for N not being an N_Entry_Call_Statement is
4830 -- defensive, covering the possibility that the processing of entry
4831 -- calls might reach this point due to later modifications of the code
4834 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4835 and then Nkind (N) /= N_Entry_Call_Statement
4836 and then Entry_Call_Statement (Parent (N)) = N
4838 if Ada_Version < Ada_05 then
4839 Error_Msg_N ("entry call required in select statement", N);
4841 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4842 -- for a procedure_or_entry_call, the procedure_name or
4843 -- procedure_prefix of the procedure_call_statement shall denote
4844 -- an entry renamed by a procedure, or (a view of) a primitive
4845 -- subprogram of a limited interface whose first parameter is
4846 -- a controlling parameter.
4848 elsif Nkind (N) = N_Procedure_Call_Statement
4849 and then not Is_Renamed_Entry (Nam)
4850 and then not Is_Controlling_Limited_Procedure (Nam)
4853 ("entry call or dispatching primitive of interface required", N);
4857 -- Check that this is not a call to a protected procedure or entry from
4858 -- within a protected function.
4860 if Ekind (Current_Scope) = E_Function
4861 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4862 and then Ekind (Nam) /= E_Function
4863 and then Scope (Nam) = Scope (Current_Scope)
4865 Error_Msg_N ("within protected function, protected " &
4866 "object is constant", N);
4867 Error_Msg_N ("\cannot call operation that may modify it", N);
4870 -- Freeze the subprogram name if not in a spec-expression. Note that we
4871 -- freeze procedure calls as well as function calls. Procedure calls are
4872 -- not frozen according to the rules (RM 13.14(14)) because it is
4873 -- impossible to have a procedure call to a non-frozen procedure in pure
4874 -- Ada, but in the code that we generate in the expander, this rule
4875 -- needs extending because we can generate procedure calls that need
4878 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4879 Freeze_Expression (Subp);
4882 -- For a predefined operator, the type of the result is the type imposed
4883 -- by context, except for a predefined operation on universal fixed.
4884 -- Otherwise The type of the call is the type returned by the subprogram
4887 if Is_Predefined_Op (Nam) then
4888 if Etype (N) /= Universal_Fixed then
4892 -- If the subprogram returns an array type, and the context requires the
4893 -- component type of that array type, the node is really an indexing of
4894 -- the parameterless call. Resolve as such. A pathological case occurs
4895 -- when the type of the component is an access to the array type. In
4896 -- this case the call is truly ambiguous.
4898 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4900 ((Is_Array_Type (Etype (Nam))
4901 and then Covers (Typ, Component_Type (Etype (Nam))))
4902 or else (Is_Access_Type (Etype (Nam))
4903 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4906 Component_Type (Designated_Type (Etype (Nam))))))
4909 Index_Node : Node_Id;
4911 Ret_Type : constant Entity_Id := Etype (Nam);
4914 if Is_Access_Type (Ret_Type)
4915 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4918 ("cannot disambiguate function call and indexing", N);
4920 New_Subp := Relocate_Node (Subp);
4921 Set_Entity (Subp, Nam);
4923 if Component_Type (Ret_Type) /= Any_Type then
4924 if Needs_No_Actuals (Nam) then
4926 -- Indexed call to a parameterless function
4929 Make_Indexed_Component (Loc,
4931 Make_Function_Call (Loc,
4933 Expressions => Parameter_Associations (N));
4935 -- An Ada 2005 prefixed call to a primitive operation
4936 -- whose first parameter is the prefix. This prefix was
4937 -- prepended to the parameter list, which is actually a
4938 -- list of indices. Remove the prefix in order to build
4939 -- the proper indexed component.
4942 Make_Indexed_Component (Loc,
4944 Make_Function_Call (Loc,
4946 Parameter_Associations =>
4948 (Remove_Head (Parameter_Associations (N)))),
4949 Expressions => Parameter_Associations (N));
4952 -- Since we are correcting a node classification error made
4953 -- by the parser, we call Replace rather than Rewrite.
4955 Replace (N, Index_Node);
4956 Set_Etype (Prefix (N), Ret_Type);
4958 Resolve_Indexed_Component (N, Typ);
4959 Check_Elab_Call (Prefix (N));
4967 Set_Etype (N, Etype (Nam));
4970 -- In the case where the call is to an overloaded subprogram, Analyze
4971 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
4972 -- such a case Normalize_Actuals needs to be called once more to order
4973 -- the actuals correctly. Otherwise the call will have the ordering
4974 -- given by the last overloaded subprogram whether this is the correct
4975 -- one being called or not.
4977 if Is_Overloaded (Subp) then
4978 Normalize_Actuals (N, Nam, False, Norm_OK);
4979 pragma Assert (Norm_OK);
4982 -- In any case, call is fully resolved now. Reset Overload flag, to
4983 -- prevent subsequent overload resolution if node is analyzed again
4985 Set_Is_Overloaded (Subp, False);
4986 Set_Is_Overloaded (N, False);
4988 -- If we are calling the current subprogram from immediately within its
4989 -- body, then that is the case where we can sometimes detect cases of
4990 -- infinite recursion statically. Do not try this in case restriction
4991 -- No_Recursion is in effect anyway, and do it only for source calls.
4993 if Comes_From_Source (N) then
4994 Scop := Current_Scope;
4996 -- Issue warning for possible infinite recursion in the absence
4997 -- of the No_Recursion restriction.
5000 and then not Restriction_Active (No_Recursion)
5001 and then Check_Infinite_Recursion (N)
5003 -- Here we detected and flagged an infinite recursion, so we do
5004 -- not need to test the case below for further warnings. Also if
5005 -- we now have a raise SE node, we are all done.
5007 if Nkind (N) = N_Raise_Storage_Error then
5011 -- If call is to immediately containing subprogram, then check for
5012 -- the case of a possible run-time detectable infinite recursion.
5015 Scope_Loop : while Scop /= Standard_Standard loop
5018 -- Although in general case, recursion is not statically
5019 -- checkable, the case of calling an immediately containing
5020 -- subprogram is easy to catch.
5022 Check_Restriction (No_Recursion, N);
5024 -- If the recursive call is to a parameterless subprogram,
5025 -- then even if we can't statically detect infinite
5026 -- recursion, this is pretty suspicious, and we output a
5027 -- warning. Furthermore, we will try later to detect some
5028 -- cases here at run time by expanding checking code (see
5029 -- Detect_Infinite_Recursion in package Exp_Ch6).
5031 -- If the recursive call is within a handler, do not emit a
5032 -- warning, because this is a common idiom: loop until input
5033 -- is correct, catch illegal input in handler and restart.
5035 if No (First_Formal (Nam))
5036 and then Etype (Nam) = Standard_Void_Type
5037 and then not Error_Posted (N)
5038 and then Nkind (Parent (N)) /= N_Exception_Handler
5040 -- For the case of a procedure call. We give the message
5041 -- only if the call is the first statement in a sequence
5042 -- of statements, or if all previous statements are
5043 -- simple assignments. This is simply a heuristic to
5044 -- decrease false positives, without losing too many good
5045 -- warnings. The idea is that these previous statements
5046 -- may affect global variables the procedure depends on.
5048 if Nkind (N) = N_Procedure_Call_Statement
5049 and then Is_List_Member (N)
5055 while Present (P) loop
5056 if Nkind (P) /= N_Assignment_Statement then
5065 -- Do not give warning if we are in a conditional context
5068 K : constant Node_Kind := Nkind (Parent (N));
5070 if (K = N_Loop_Statement
5071 and then Present (Iteration_Scheme (Parent (N))))
5072 or else K = N_If_Statement
5073 or else K = N_Elsif_Part
5074 or else K = N_Case_Statement_Alternative
5080 -- Here warning is to be issued
5082 Set_Has_Recursive_Call (Nam);
5084 ("?possible infinite recursion!", N);
5086 ("\?Storage_Error may be raised at run time!", N);
5092 Scop := Scope (Scop);
5093 end loop Scope_Loop;
5097 -- If subprogram name is a predefined operator, it was given in
5098 -- functional notation. Replace call node with operator node, so
5099 -- that actuals can be resolved appropriately.
5101 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5102 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5105 elsif Present (Alias (Nam))
5106 and then Is_Predefined_Op (Alias (Nam))
5108 Resolve_Actuals (N, Nam);
5109 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5113 -- Create a transient scope if the resulting type requires it
5115 -- There are several notable exceptions:
5117 -- a) In init procs, the transient scope overhead is not needed, and is
5118 -- even incorrect when the call is a nested initialization call for a
5119 -- component whose expansion may generate adjust calls. However, if the
5120 -- call is some other procedure call within an initialization procedure
5121 -- (for example a call to Create_Task in the init_proc of the task
5122 -- run-time record) a transient scope must be created around this call.
5124 -- b) Enumeration literal pseudo-calls need no transient scope
5126 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5127 -- functions) do not use the secondary stack even though the return
5128 -- type may be unconstrained.
5130 -- d) Calls to a build-in-place function, since such functions may
5131 -- allocate their result directly in a target object, and cases where
5132 -- the result does get allocated in the secondary stack are checked for
5133 -- within the specialized Exp_Ch6 procedures for expanding those
5134 -- build-in-place calls.
5136 -- e) If the subprogram is marked Inline_Always, then even if it returns
5137 -- an unconstrained type the call does not require use of the secondary
5138 -- stack. However, inlining will only take place if the body to inline
5139 -- is already present. It may not be available if e.g. the subprogram is
5140 -- declared in a child instance.
5142 -- If this is an initialization call for a type whose construction
5143 -- uses the secondary stack, and it is not a nested call to initialize
5144 -- a component, we do need to create a transient scope for it. We
5145 -- check for this by traversing the type in Check_Initialization_Call.
5148 and then Has_Pragma_Inline_Always (Nam)
5149 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5150 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5154 elsif Ekind (Nam) = E_Enumeration_Literal
5155 or else Is_Build_In_Place_Function (Nam)
5156 or else Is_Intrinsic_Subprogram (Nam)
5160 elsif Expander_Active
5161 and then Is_Type (Etype (Nam))
5162 and then Requires_Transient_Scope (Etype (Nam))
5164 (not Within_Init_Proc
5166 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5168 Establish_Transient_Scope (N, Sec_Stack => True);
5170 -- If the call appears within the bounds of a loop, it will
5171 -- be rewritten and reanalyzed, nothing left to do here.
5173 if Nkind (N) /= N_Function_Call then
5177 elsif Is_Init_Proc (Nam)
5178 and then not Within_Init_Proc
5180 Check_Initialization_Call (N, Nam);
5183 -- A protected function cannot be called within the definition of the
5184 -- enclosing protected type.
5186 if Is_Protected_Type (Scope (Nam))
5187 and then In_Open_Scopes (Scope (Nam))
5188 and then not Has_Completion (Scope (Nam))
5191 ("& cannot be called before end of protected definition", N, Nam);
5194 -- Propagate interpretation to actuals, and add default expressions
5197 if Present (First_Formal (Nam)) then
5198 Resolve_Actuals (N, Nam);
5200 -- Overloaded literals are rewritten as function calls, for purpose of
5201 -- resolution. After resolution, we can replace the call with the
5204 elsif Ekind (Nam) = E_Enumeration_Literal then
5205 Copy_Node (Subp, N);
5206 Resolve_Entity_Name (N, Typ);
5208 -- Avoid validation, since it is a static function call
5210 Generate_Reference (Nam, Subp);
5214 -- If the subprogram is not global, then kill all saved values and
5215 -- checks. This is a bit conservative, since in many cases we could do
5216 -- better, but it is not worth the effort. Similarly, we kill constant
5217 -- values. However we do not need to do this for internal entities
5218 -- (unless they are inherited user-defined subprograms), since they
5219 -- are not in the business of molesting local values.
5221 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5222 -- kill all checks and values for calls to global subprograms. This
5223 -- takes care of the case where an access to a local subprogram is
5224 -- taken, and could be passed directly or indirectly and then called
5225 -- from almost any context.
5227 -- Note: we do not do this step till after resolving the actuals. That
5228 -- way we still take advantage of the current value information while
5229 -- scanning the actuals.
5231 -- We suppress killing values if we are processing the nodes associated
5232 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5233 -- type kills all the values as part of analyzing the code that
5234 -- initializes the dispatch tables.
5236 if Inside_Freezing_Actions = 0
5237 and then (not Is_Library_Level_Entity (Nam)
5238 or else Suppress_Value_Tracking_On_Call
5239 (Nearest_Dynamic_Scope (Current_Scope)))
5240 and then (Comes_From_Source (Nam)
5241 or else (Present (Alias (Nam))
5242 and then Comes_From_Source (Alias (Nam))))
5244 Kill_Current_Values;
5247 -- If we are warning about unread OUT parameters, this is the place to
5248 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5249 -- after the above call to Kill_Current_Values (since that call clears
5250 -- the Last_Assignment field of all local variables).
5252 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5253 and then Comes_From_Source (N)
5254 and then In_Extended_Main_Source_Unit (N)
5261 F := First_Formal (Nam);
5262 A := First_Actual (N);
5263 while Present (F) and then Present (A) loop
5264 if (Ekind (F) = E_Out_Parameter
5266 Ekind (F) = E_In_Out_Parameter)
5267 and then Warn_On_Modified_As_Out_Parameter (F)
5268 and then Is_Entity_Name (A)
5269 and then Present (Entity (A))
5270 and then Comes_From_Source (N)
5271 and then Safe_To_Capture_Value (N, Entity (A))
5273 Set_Last_Assignment (Entity (A), A);
5282 -- If the subprogram is a primitive operation, check whether or not
5283 -- it is a correct dispatching call.
5285 if Is_Overloadable (Nam)
5286 and then Is_Dispatching_Operation (Nam)
5288 Check_Dispatching_Call (N);
5290 elsif Ekind (Nam) /= E_Subprogram_Type
5291 and then Is_Abstract_Subprogram (Nam)
5292 and then not In_Instance
5294 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5297 -- If this is a dispatching call, generate the appropriate reference,
5298 -- for better source navigation in GPS.
5300 if Is_Overloadable (Nam)
5301 and then Present (Controlling_Argument (N))
5303 Generate_Reference (Nam, Subp, 'R');
5305 -- Normal case, not a dispatching call
5308 Generate_Reference (Nam, Subp);
5311 if Is_Intrinsic_Subprogram (Nam) then
5312 Check_Intrinsic_Call (N);
5315 -- Check for violation of restriction No_Specific_Termination_Handlers
5316 -- and warn on a potentially blocking call to Abort_Task.
5318 if Is_RTE (Nam, RE_Set_Specific_Handler)
5320 Is_RTE (Nam, RE_Specific_Handler)
5322 Check_Restriction (No_Specific_Termination_Handlers, N);
5324 elsif Is_RTE (Nam, RE_Abort_Task) then
5325 Check_Potentially_Blocking_Operation (N);
5328 -- Issue an error for a call to an eliminated subprogram
5330 Check_For_Eliminated_Subprogram (Subp, Nam);
5332 -- All done, evaluate call and deal with elaboration issues
5335 Check_Elab_Call (N);
5338 -------------------------------
5339 -- Resolve_Character_Literal --
5340 -------------------------------
5342 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5343 B_Typ : constant Entity_Id := Base_Type (Typ);
5347 -- Verify that the character does belong to the type of the context
5349 Set_Etype (N, B_Typ);
5350 Eval_Character_Literal (N);
5352 -- Wide_Wide_Character literals must always be defined, since the set
5353 -- of wide wide character literals is complete, i.e. if a character
5354 -- literal is accepted by the parser, then it is OK for wide wide
5355 -- character (out of range character literals are rejected).
5357 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5360 -- Always accept character literal for type Any_Character, which
5361 -- occurs in error situations and in comparisons of literals, both
5362 -- of which should accept all literals.
5364 elsif B_Typ = Any_Character then
5367 -- For Standard.Character or a type derived from it, check that
5368 -- the literal is in range
5370 elsif Root_Type (B_Typ) = Standard_Character then
5371 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5375 -- For Standard.Wide_Character or a type derived from it, check
5376 -- that the literal is in range
5378 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5379 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5383 -- For Standard.Wide_Wide_Character or a type derived from it, we
5384 -- know the literal is in range, since the parser checked!
5386 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5389 -- If the entity is already set, this has already been resolved in a
5390 -- generic context, or comes from expansion. Nothing else to do.
5392 elsif Present (Entity (N)) then
5395 -- Otherwise we have a user defined character type, and we can use the
5396 -- standard visibility mechanisms to locate the referenced entity.
5399 C := Current_Entity (N);
5400 while Present (C) loop
5401 if Etype (C) = B_Typ then
5402 Set_Entity_With_Style_Check (N, C);
5403 Generate_Reference (C, N);
5411 -- If we fall through, then the literal does not match any of the
5412 -- entries of the enumeration type. This isn't just a constraint
5413 -- error situation, it is an illegality (see RM 4.2).
5416 ("character not defined for }", N, First_Subtype (B_Typ));
5417 end Resolve_Character_Literal;
5419 ---------------------------
5420 -- Resolve_Comparison_Op --
5421 ---------------------------
5423 -- Context requires a boolean type, and plays no role in resolution.
5424 -- Processing identical to that for equality operators. The result
5425 -- type is the base type, which matters when pathological subtypes of
5426 -- booleans with limited ranges are used.
5428 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5429 L : constant Node_Id := Left_Opnd (N);
5430 R : constant Node_Id := Right_Opnd (N);
5434 -- If this is an intrinsic operation which is not predefined, use the
5435 -- types of its declared arguments to resolve the possibly overloaded
5436 -- operands. Otherwise the operands are unambiguous and specify the
5439 if Scope (Entity (N)) /= Standard_Standard then
5440 T := Etype (First_Entity (Entity (N)));
5443 T := Find_Unique_Type (L, R);
5445 if T = Any_Fixed then
5446 T := Unique_Fixed_Point_Type (L);
5450 Set_Etype (N, Base_Type (Typ));
5451 Generate_Reference (T, N, ' ');
5453 if T /= Any_Type then
5454 if T = Any_String or else
5455 T = Any_Composite or else
5458 if T = Any_Character then
5459 Ambiguous_Character (L);
5461 Error_Msg_N ("ambiguous operands for comparison", N);
5464 Set_Etype (N, Any_Type);
5470 Check_Unset_Reference (L);
5471 Check_Unset_Reference (R);
5472 Generate_Operator_Reference (N, T);
5473 Check_Low_Bound_Tested (N);
5474 Eval_Relational_Op (N);
5477 end Resolve_Comparison_Op;
5479 ------------------------------------
5480 -- Resolve_Conditional_Expression --
5481 ------------------------------------
5483 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5484 Condition : constant Node_Id := First (Expressions (N));
5485 Then_Expr : constant Node_Id := Next (Condition);
5486 Else_Expr : constant Node_Id := Next (Then_Expr);
5488 Resolve (Condition, Standard_Boolean);
5489 Resolve (Then_Expr, Typ);
5490 Resolve (Else_Expr, Typ);
5492 Eval_Conditional_Expression (N);
5493 end Resolve_Conditional_Expression;
5495 -----------------------------------------
5496 -- Resolve_Discrete_Subtype_Indication --
5497 -----------------------------------------
5499 procedure Resolve_Discrete_Subtype_Indication
5507 Analyze (Subtype_Mark (N));
5508 S := Entity (Subtype_Mark (N));
5510 if Nkind (Constraint (N)) /= N_Range_Constraint then
5511 Error_Msg_N ("expect range constraint for discrete type", N);
5512 Set_Etype (N, Any_Type);
5515 R := Range_Expression (Constraint (N));
5523 if Base_Type (S) /= Base_Type (Typ) then
5525 ("expect subtype of }", N, First_Subtype (Typ));
5527 -- Rewrite the constraint as a range of Typ
5528 -- to allow compilation to proceed further.
5531 Rewrite (Low_Bound (R),
5532 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5533 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5534 Attribute_Name => Name_First));
5535 Rewrite (High_Bound (R),
5536 Make_Attribute_Reference (Sloc (High_Bound (R)),
5537 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5538 Attribute_Name => Name_First));
5542 Set_Etype (N, Etype (R));
5544 -- Additionally, we must check that the bounds are compatible
5545 -- with the given subtype, which might be different from the
5546 -- type of the context.
5548 Apply_Range_Check (R, S);
5550 -- ??? If the above check statically detects a Constraint_Error
5551 -- it replaces the offending bound(s) of the range R with a
5552 -- Constraint_Error node. When the itype which uses these bounds
5553 -- is frozen the resulting call to Duplicate_Subexpr generates
5554 -- a new temporary for the bounds.
5556 -- Unfortunately there are other itypes that are also made depend
5557 -- on these bounds, so when Duplicate_Subexpr is called they get
5558 -- a forward reference to the newly created temporaries and Gigi
5559 -- aborts on such forward references. This is probably sign of a
5560 -- more fundamental problem somewhere else in either the order of
5561 -- itype freezing or the way certain itypes are constructed.
5563 -- To get around this problem we call Remove_Side_Effects right
5564 -- away if either bounds of R are a Constraint_Error.
5567 L : constant Node_Id := Low_Bound (R);
5568 H : constant Node_Id := High_Bound (R);
5571 if Nkind (L) = N_Raise_Constraint_Error then
5572 Remove_Side_Effects (L);
5575 if Nkind (H) = N_Raise_Constraint_Error then
5576 Remove_Side_Effects (H);
5580 Check_Unset_Reference (Low_Bound (R));
5581 Check_Unset_Reference (High_Bound (R));
5584 end Resolve_Discrete_Subtype_Indication;
5586 -------------------------
5587 -- Resolve_Entity_Name --
5588 -------------------------
5590 -- Used to resolve identifiers and expanded names
5592 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5593 E : constant Entity_Id := Entity (N);
5596 -- If garbage from errors, set to Any_Type and return
5598 if No (E) and then Total_Errors_Detected /= 0 then
5599 Set_Etype (N, Any_Type);
5603 -- Replace named numbers by corresponding literals. Note that this is
5604 -- the one case where Resolve_Entity_Name must reset the Etype, since
5605 -- it is currently marked as universal.
5607 if Ekind (E) = E_Named_Integer then
5609 Eval_Named_Integer (N);
5611 elsif Ekind (E) = E_Named_Real then
5613 Eval_Named_Real (N);
5615 -- Allow use of subtype only if it is a concurrent type where we are
5616 -- currently inside the body. This will eventually be expanded into a
5617 -- call to Self (for tasks) or _object (for protected objects). Any
5618 -- other use of a subtype is invalid.
5620 elsif Is_Type (E) then
5621 if Is_Concurrent_Type (E)
5622 and then In_Open_Scopes (E)
5627 ("invalid use of subtype mark in expression or call", N);
5630 -- Check discriminant use if entity is discriminant in current scope,
5631 -- i.e. discriminant of record or concurrent type currently being
5632 -- analyzed. Uses in corresponding body are unrestricted.
5634 elsif Ekind (E) = E_Discriminant
5635 and then Scope (E) = Current_Scope
5636 and then not Has_Completion (Current_Scope)
5638 Check_Discriminant_Use (N);
5640 -- A parameterless generic function cannot appear in a context that
5641 -- requires resolution.
5643 elsif Ekind (E) = E_Generic_Function then
5644 Error_Msg_N ("illegal use of generic function", N);
5646 elsif Ekind (E) = E_Out_Parameter
5647 and then Ada_Version = Ada_83
5648 and then (Nkind (Parent (N)) in N_Op
5649 or else (Nkind (Parent (N)) = N_Assignment_Statement
5650 and then N = Expression (Parent (N)))
5651 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5653 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5655 -- In all other cases, just do the possible static evaluation
5658 -- A deferred constant that appears in an expression must have a
5659 -- completion, unless it has been removed by in-place expansion of
5662 if Ekind (E) = E_Constant
5663 and then Comes_From_Source (E)
5664 and then No (Constant_Value (E))
5665 and then Is_Frozen (Etype (E))
5666 and then not In_Spec_Expression
5667 and then not Is_Imported (E)
5670 if No_Initialization (Parent (E))
5671 or else (Present (Full_View (E))
5672 and then No_Initialization (Parent (Full_View (E))))
5677 "deferred constant is frozen before completion", N);
5681 Eval_Entity_Name (N);
5683 end Resolve_Entity_Name;
5689 procedure Resolve_Entry (Entry_Name : Node_Id) is
5690 Loc : constant Source_Ptr := Sloc (Entry_Name);
5698 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5699 -- If the bounds of the entry family being called depend on task
5700 -- discriminants, build a new index subtype where a discriminant is
5701 -- replaced with the value of the discriminant of the target task.
5702 -- The target task is the prefix of the entry name in the call.
5704 -----------------------
5705 -- Actual_Index_Type --
5706 -----------------------
5708 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5709 Typ : constant Entity_Id := Entry_Index_Type (E);
5710 Tsk : constant Entity_Id := Scope (E);
5711 Lo : constant Node_Id := Type_Low_Bound (Typ);
5712 Hi : constant Node_Id := Type_High_Bound (Typ);
5715 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5716 -- If the bound is given by a discriminant, replace with a reference
5717 -- to the discriminant of the same name in the target task. If the
5718 -- entry name is the target of a requeue statement and the entry is
5719 -- in the current protected object, the bound to be used is the
5720 -- discriminal of the object (see apply_range_checks for details of
5721 -- the transformation).
5723 -----------------------------
5724 -- Actual_Discriminant_Ref --
5725 -----------------------------
5727 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5728 Typ : constant Entity_Id := Etype (Bound);
5732 Remove_Side_Effects (Bound);
5734 if not Is_Entity_Name (Bound)
5735 or else Ekind (Entity (Bound)) /= E_Discriminant
5739 elsif Is_Protected_Type (Tsk)
5740 and then In_Open_Scopes (Tsk)
5741 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5743 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5747 Make_Selected_Component (Loc,
5748 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5749 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5754 end Actual_Discriminant_Ref;
5756 -- Start of processing for Actual_Index_Type
5759 if not Has_Discriminants (Tsk)
5760 or else (not Is_Entity_Name (Lo)
5762 not Is_Entity_Name (Hi))
5764 return Entry_Index_Type (E);
5767 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5768 Set_Etype (New_T, Base_Type (Typ));
5769 Set_Size_Info (New_T, Typ);
5770 Set_RM_Size (New_T, RM_Size (Typ));
5771 Set_Scalar_Range (New_T,
5772 Make_Range (Sloc (Entry_Name),
5773 Low_Bound => Actual_Discriminant_Ref (Lo),
5774 High_Bound => Actual_Discriminant_Ref (Hi)));
5778 end Actual_Index_Type;
5780 -- Start of processing of Resolve_Entry
5783 -- Find name of entry being called, and resolve prefix of name
5784 -- with its own type. The prefix can be overloaded, and the name
5785 -- and signature of the entry must be taken into account.
5787 if Nkind (Entry_Name) = N_Indexed_Component then
5789 -- Case of dealing with entry family within the current tasks
5791 E_Name := Prefix (Entry_Name);
5794 E_Name := Entry_Name;
5797 if Is_Entity_Name (E_Name) then
5799 -- Entry call to an entry (or entry family) in the current task. This
5800 -- is legal even though the task will deadlock. Rewrite as call to
5803 -- This can also be a call to an entry in an enclosing task. If this
5804 -- is a single task, we have to retrieve its name, because the scope
5805 -- of the entry is the task type, not the object. If the enclosing
5806 -- task is a task type, the identity of the task is given by its own
5809 -- Finally this can be a requeue on an entry of the same task or
5810 -- protected object.
5812 S := Scope (Entity (E_Name));
5814 for J in reverse 0 .. Scope_Stack.Last loop
5815 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5816 and then not Comes_From_Source (S)
5818 -- S is an enclosing task or protected object. The concurrent
5819 -- declaration has been converted into a type declaration, and
5820 -- the object itself has an object declaration that follows
5821 -- the type in the same declarative part.
5823 Tsk := Next_Entity (S);
5824 while Etype (Tsk) /= S loop
5831 elsif S = Scope_Stack.Table (J).Entity then
5833 -- Call to current task. Will be transformed into call to Self
5841 Make_Selected_Component (Loc,
5842 Prefix => New_Occurrence_Of (S, Loc),
5844 New_Occurrence_Of (Entity (E_Name), Loc));
5845 Rewrite (E_Name, New_N);
5848 elsif Nkind (Entry_Name) = N_Selected_Component
5849 and then Is_Overloaded (Prefix (Entry_Name))
5851 -- Use the entry name (which must be unique at this point) to find
5852 -- the prefix that returns the corresponding task type or protected
5856 Pref : constant Node_Id := Prefix (Entry_Name);
5857 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5862 Get_First_Interp (Pref, I, It);
5863 while Present (It.Typ) loop
5864 if Scope (Ent) = It.Typ then
5865 Set_Etype (Pref, It.Typ);
5869 Get_Next_Interp (I, It);
5874 if Nkind (Entry_Name) = N_Selected_Component then
5875 Resolve (Prefix (Entry_Name));
5877 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5878 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5879 Resolve (Prefix (Prefix (Entry_Name)));
5880 Index := First (Expressions (Entry_Name));
5881 Resolve (Index, Entry_Index_Type (Nam));
5883 -- Up to this point the expression could have been the actual in a
5884 -- simple entry call, and be given by a named association.
5886 if Nkind (Index) = N_Parameter_Association then
5887 Error_Msg_N ("expect expression for entry index", Index);
5889 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5894 ------------------------
5895 -- Resolve_Entry_Call --
5896 ------------------------
5898 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5899 Entry_Name : constant Node_Id := Name (N);
5900 Loc : constant Source_Ptr := Sloc (Entry_Name);
5902 First_Named : Node_Id;
5909 -- We kill all checks here, because it does not seem worth the effort to
5910 -- do anything better, an entry call is a big operation.
5914 -- Processing of the name is similar for entry calls and protected
5915 -- operation calls. Once the entity is determined, we can complete
5916 -- the resolution of the actuals.
5918 -- The selector may be overloaded, in the case of a protected object
5919 -- with overloaded functions. The type of the context is used for
5922 if Nkind (Entry_Name) = N_Selected_Component
5923 and then Is_Overloaded (Selector_Name (Entry_Name))
5924 and then Typ /= Standard_Void_Type
5931 Get_First_Interp (Selector_Name (Entry_Name), I, It);
5932 while Present (It.Typ) loop
5933 if Covers (Typ, It.Typ) then
5934 Set_Entity (Selector_Name (Entry_Name), It.Nam);
5935 Set_Etype (Entry_Name, It.Typ);
5937 Generate_Reference (It.Typ, N, ' ');
5940 Get_Next_Interp (I, It);
5945 Resolve_Entry (Entry_Name);
5947 if Nkind (Entry_Name) = N_Selected_Component then
5949 -- Simple entry call
5951 Nam := Entity (Selector_Name (Entry_Name));
5952 Obj := Prefix (Entry_Name);
5953 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
5955 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5957 -- Call to member of entry family
5959 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5960 Obj := Prefix (Prefix (Entry_Name));
5961 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
5964 -- We cannot in general check the maximum depth of protected entry
5965 -- calls at compile time. But we can tell that any protected entry
5966 -- call at all violates a specified nesting depth of zero.
5968 if Is_Protected_Type (Scope (Nam)) then
5969 Check_Restriction (Max_Entry_Queue_Length, N);
5972 -- Use context type to disambiguate a protected function that can be
5973 -- called without actuals and that returns an array type, and where
5974 -- the argument list may be an indexing of the returned value.
5976 if Ekind (Nam) = E_Function
5977 and then Needs_No_Actuals (Nam)
5978 and then Present (Parameter_Associations (N))
5980 ((Is_Array_Type (Etype (Nam))
5981 and then Covers (Typ, Component_Type (Etype (Nam))))
5983 or else (Is_Access_Type (Etype (Nam))
5984 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5985 and then Covers (Typ,
5986 Component_Type (Designated_Type (Etype (Nam))))))
5989 Index_Node : Node_Id;
5993 Make_Indexed_Component (Loc,
5995 Make_Function_Call (Loc,
5996 Name => Relocate_Node (Entry_Name)),
5997 Expressions => Parameter_Associations (N));
5999 -- Since we are correcting a node classification error made by
6000 -- the parser, we call Replace rather than Rewrite.
6002 Replace (N, Index_Node);
6003 Set_Etype (Prefix (N), Etype (Nam));
6005 Resolve_Indexed_Component (N, Typ);
6010 -- The operation name may have been overloaded. Order the actuals
6011 -- according to the formals of the resolved entity, and set the
6012 -- return type to that of the operation.
6015 Normalize_Actuals (N, Nam, False, Norm_OK);
6016 pragma Assert (Norm_OK);
6017 Set_Etype (N, Etype (Nam));
6020 Resolve_Actuals (N, Nam);
6021 Generate_Reference (Nam, Entry_Name);
6023 if Ekind (Nam) = E_Entry
6024 or else Ekind (Nam) = E_Entry_Family
6026 Check_Potentially_Blocking_Operation (N);
6029 -- Verify that a procedure call cannot masquerade as an entry
6030 -- call where an entry call is expected.
6032 if Ekind (Nam) = E_Procedure then
6033 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6034 and then N = Entry_Call_Statement (Parent (N))
6036 Error_Msg_N ("entry call required in select statement", N);
6038 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6039 and then N = Triggering_Statement (Parent (N))
6041 Error_Msg_N ("triggering statement cannot be procedure call", N);
6043 elsif Ekind (Scope (Nam)) = E_Task_Type
6044 and then not In_Open_Scopes (Scope (Nam))
6046 Error_Msg_N ("task has no entry with this name", Entry_Name);
6050 -- After resolution, entry calls and protected procedure calls are
6051 -- changed into entry calls, for expansion. The structure of the node
6052 -- does not change, so it can safely be done in place. Protected
6053 -- function calls must keep their structure because they are
6056 if Ekind (Nam) /= E_Function then
6058 -- A protected operation that is not a function may modify the
6059 -- corresponding object, and cannot apply to a constant. If this
6060 -- is an internal call, the prefix is the type itself.
6062 if Is_Protected_Type (Scope (Nam))
6063 and then not Is_Variable (Obj)
6064 and then (not Is_Entity_Name (Obj)
6065 or else not Is_Type (Entity (Obj)))
6068 ("prefix of protected procedure or entry call must be variable",
6072 Actuals := Parameter_Associations (N);
6073 First_Named := First_Named_Actual (N);
6076 Make_Entry_Call_Statement (Loc,
6078 Parameter_Associations => Actuals));
6080 Set_First_Named_Actual (N, First_Named);
6081 Set_Analyzed (N, True);
6083 -- Protected functions can return on the secondary stack, in which
6084 -- case we must trigger the transient scope mechanism.
6086 elsif Expander_Active
6087 and then Requires_Transient_Scope (Etype (Nam))
6089 Establish_Transient_Scope (N, Sec_Stack => True);
6091 end Resolve_Entry_Call;
6093 -------------------------
6094 -- Resolve_Equality_Op --
6095 -------------------------
6097 -- Both arguments must have the same type, and the boolean context does
6098 -- not participate in the resolution. The first pass verifies that the
6099 -- interpretation is not ambiguous, and the type of the left argument is
6100 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6101 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6102 -- though they carry a single (universal) type. Diagnose this case here.
6104 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6105 L : constant Node_Id := Left_Opnd (N);
6106 R : constant Node_Id := Right_Opnd (N);
6107 T : Entity_Id := Find_Unique_Type (L, R);
6109 function Find_Unique_Access_Type return Entity_Id;
6110 -- In the case of allocators, make a last-ditch attempt to find a single
6111 -- access type with the right designated type. This is semantically
6112 -- dubious, and of no interest to any real code, but c48008a makes it
6115 -----------------------------
6116 -- Find_Unique_Access_Type --
6117 -----------------------------
6119 function Find_Unique_Access_Type return Entity_Id is
6125 if Ekind (Etype (R)) = E_Allocator_Type then
6126 Acc := Designated_Type (Etype (R));
6127 elsif Ekind (Etype (L)) = E_Allocator_Type then
6128 Acc := Designated_Type (Etype (L));
6134 while S /= Standard_Standard loop
6135 E := First_Entity (S);
6136 while Present (E) loop
6138 and then Is_Access_Type (E)
6139 and then Ekind (E) /= E_Allocator_Type
6140 and then Designated_Type (E) = Base_Type (Acc)
6152 end Find_Unique_Access_Type;
6154 -- Start of processing for Resolve_Equality_Op
6157 Set_Etype (N, Base_Type (Typ));
6158 Generate_Reference (T, N, ' ');
6160 if T = Any_Fixed then
6161 T := Unique_Fixed_Point_Type (L);
6164 if T /= Any_Type then
6166 or else T = Any_Composite
6167 or else T = Any_Character
6169 if T = Any_Character then
6170 Ambiguous_Character (L);
6172 Error_Msg_N ("ambiguous operands for equality", N);
6175 Set_Etype (N, Any_Type);
6178 elsif T = Any_Access
6179 or else Ekind (T) = E_Allocator_Type
6180 or else Ekind (T) = E_Access_Attribute_Type
6182 T := Find_Unique_Access_Type;
6185 Error_Msg_N ("ambiguous operands for equality", N);
6186 Set_Etype (N, Any_Type);
6194 -- If the unique type is a class-wide type then it will be expanded
6195 -- into a dispatching call to the predefined primitive. Therefore we
6196 -- check here for potential violation of such restriction.
6198 if Is_Class_Wide_Type (T) then
6199 Check_Restriction (No_Dispatching_Calls, N);
6202 if Warn_On_Redundant_Constructs
6203 and then Comes_From_Source (N)
6204 and then Is_Entity_Name (R)
6205 and then Entity (R) = Standard_True
6206 and then Comes_From_Source (R)
6208 Error_Msg_N ("?comparison with True is redundant!", R);
6211 Check_Unset_Reference (L);
6212 Check_Unset_Reference (R);
6213 Generate_Operator_Reference (N, T);
6214 Check_Low_Bound_Tested (N);
6216 -- If this is an inequality, it may be the implicit inequality
6217 -- created for a user-defined operation, in which case the corres-
6218 -- ponding equality operation is not intrinsic, and the operation
6219 -- cannot be constant-folded. Else fold.
6221 if Nkind (N) = N_Op_Eq
6222 or else Comes_From_Source (Entity (N))
6223 or else Ekind (Entity (N)) = E_Operator
6224 or else Is_Intrinsic_Subprogram
6225 (Corresponding_Equality (Entity (N)))
6227 Eval_Relational_Op (N);
6229 elsif Nkind (N) = N_Op_Ne
6230 and then Is_Abstract_Subprogram (Entity (N))
6232 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6235 -- Ada 2005: If one operand is an anonymous access type, convert the
6236 -- other operand to it, to ensure that the underlying types match in
6237 -- the back-end. Same for access_to_subprogram, and the conversion
6238 -- verifies that the types are subtype conformant.
6240 -- We apply the same conversion in the case one of the operands is a
6241 -- private subtype of the type of the other.
6243 -- Why the Expander_Active test here ???
6247 (Ekind (T) = E_Anonymous_Access_Type
6248 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6249 or else Is_Private_Type (T))
6251 if Etype (L) /= T then
6253 Make_Unchecked_Type_Conversion (Sloc (L),
6254 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6255 Expression => Relocate_Node (L)));
6256 Analyze_And_Resolve (L, T);
6259 if (Etype (R)) /= T then
6261 Make_Unchecked_Type_Conversion (Sloc (R),
6262 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6263 Expression => Relocate_Node (R)));
6264 Analyze_And_Resolve (R, T);
6268 end Resolve_Equality_Op;
6270 ----------------------------------
6271 -- Resolve_Explicit_Dereference --
6272 ----------------------------------
6274 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6275 Loc : constant Source_Ptr := Sloc (N);
6277 P : constant Node_Id := Prefix (N);
6282 Check_Fully_Declared_Prefix (Typ, P);
6284 if Is_Overloaded (P) then
6286 -- Use the context type to select the prefix that has the correct
6289 Get_First_Interp (P, I, It);
6290 while Present (It.Typ) loop
6291 exit when Is_Access_Type (It.Typ)
6292 and then Covers (Typ, Designated_Type (It.Typ));
6293 Get_Next_Interp (I, It);
6296 if Present (It.Typ) then
6297 Resolve (P, It.Typ);
6299 -- If no interpretation covers the designated type of the prefix,
6300 -- this is the pathological case where not all implementations of
6301 -- the prefix allow the interpretation of the node as a call. Now
6302 -- that the expected type is known, Remove other interpretations
6303 -- from prefix, rewrite it as a call, and resolve again, so that
6304 -- the proper call node is generated.
6306 Get_First_Interp (P, I, It);
6307 while Present (It.Typ) loop
6308 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6312 Get_Next_Interp (I, It);
6316 Make_Function_Call (Loc,
6318 Make_Explicit_Dereference (Loc,
6320 Parameter_Associations => New_List);
6322 Save_Interps (N, New_N);
6324 Analyze_And_Resolve (N, Typ);
6328 Set_Etype (N, Designated_Type (It.Typ));
6334 if Is_Access_Type (Etype (P)) then
6335 Apply_Access_Check (N);
6338 -- If the designated type is a packed unconstrained array type, and the
6339 -- explicit dereference is not in the context of an attribute reference,
6340 -- then we must compute and set the actual subtype, since it is needed
6341 -- by Gigi. The reason we exclude the attribute case is that this is
6342 -- handled fine by Gigi, and in fact we use such attributes to build the
6343 -- actual subtype. We also exclude generated code (which builds actual
6344 -- subtypes directly if they are needed).
6346 if Is_Array_Type (Etype (N))
6347 and then Is_Packed (Etype (N))
6348 and then not Is_Constrained (Etype (N))
6349 and then Nkind (Parent (N)) /= N_Attribute_Reference
6350 and then Comes_From_Source (N)
6352 Set_Etype (N, Get_Actual_Subtype (N));
6355 -- Note: there is no Eval processing required for an explicit deference,
6356 -- because the type is known to be an allocators, and allocator
6357 -- expressions can never be static.
6359 end Resolve_Explicit_Dereference;
6361 -------------------------------
6362 -- Resolve_Indexed_Component --
6363 -------------------------------
6365 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6366 Name : constant Node_Id := Prefix (N);
6368 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6372 if Is_Overloaded (Name) then
6374 -- Use the context type to select the prefix that yields the correct
6380 I1 : Interp_Index := 0;
6381 P : constant Node_Id := Prefix (N);
6382 Found : Boolean := False;
6385 Get_First_Interp (P, I, It);
6386 while Present (It.Typ) loop
6387 if (Is_Array_Type (It.Typ)
6388 and then Covers (Typ, Component_Type (It.Typ)))
6389 or else (Is_Access_Type (It.Typ)
6390 and then Is_Array_Type (Designated_Type (It.Typ))
6392 (Typ, Component_Type (Designated_Type (It.Typ))))
6395 It := Disambiguate (P, I1, I, Any_Type);
6397 if It = No_Interp then
6398 Error_Msg_N ("ambiguous prefix for indexing", N);
6404 Array_Type := It.Typ;
6410 Array_Type := It.Typ;
6415 Get_Next_Interp (I, It);
6420 Array_Type := Etype (Name);
6423 Resolve (Name, Array_Type);
6424 Array_Type := Get_Actual_Subtype_If_Available (Name);
6426 -- If prefix is access type, dereference to get real array type.
6427 -- Note: we do not apply an access check because the expander always
6428 -- introduces an explicit dereference, and the check will happen there.
6430 if Is_Access_Type (Array_Type) then
6431 Array_Type := Designated_Type (Array_Type);
6434 -- If name was overloaded, set component type correctly now
6435 -- If a misplaced call to an entry family (which has no index types)
6436 -- return. Error will be diagnosed from calling context.
6438 if Is_Array_Type (Array_Type) then
6439 Set_Etype (N, Component_Type (Array_Type));
6444 Index := First_Index (Array_Type);
6445 Expr := First (Expressions (N));
6447 -- The prefix may have resolved to a string literal, in which case its
6448 -- etype has a special representation. This is only possible currently
6449 -- if the prefix is a static concatenation, written in functional
6452 if Ekind (Array_Type) = E_String_Literal_Subtype then
6453 Resolve (Expr, Standard_Positive);
6456 while Present (Index) and Present (Expr) loop
6457 Resolve (Expr, Etype (Index));
6458 Check_Unset_Reference (Expr);
6460 if Is_Scalar_Type (Etype (Expr)) then
6461 Apply_Scalar_Range_Check (Expr, Etype (Index));
6463 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6471 -- Do not generate the warning on suspicious index if we are analyzing
6472 -- package Ada.Tags; otherwise we will report the warning with the
6473 -- Prims_Ptr field of the dispatch table.
6475 if Scope (Etype (Prefix (N))) = Standard_Standard
6477 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6480 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6481 Eval_Indexed_Component (N);
6483 end Resolve_Indexed_Component;
6485 -----------------------------
6486 -- Resolve_Integer_Literal --
6487 -----------------------------
6489 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6492 Eval_Integer_Literal (N);
6493 end Resolve_Integer_Literal;
6495 --------------------------------
6496 -- Resolve_Intrinsic_Operator --
6497 --------------------------------
6499 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6500 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6507 while Scope (Op) /= Standard_Standard loop
6509 pragma Assert (Present (Op));
6513 Set_Is_Overloaded (N, False);
6515 -- If the operand type is private, rewrite with suitable conversions on
6516 -- the operands and the result, to expose the proper underlying numeric
6519 if Is_Private_Type (Typ) then
6520 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6522 if Nkind (N) = N_Op_Expon then
6523 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6525 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6528 Save_Interps (Left_Opnd (N), Expression (Arg1));
6529 Save_Interps (Right_Opnd (N), Expression (Arg2));
6531 Set_Left_Opnd (N, Arg1);
6532 Set_Right_Opnd (N, Arg2);
6534 Set_Etype (N, Btyp);
6535 Rewrite (N, Unchecked_Convert_To (Typ, N));
6538 elsif Typ /= Etype (Left_Opnd (N))
6539 or else Typ /= Etype (Right_Opnd (N))
6541 -- Add explicit conversion where needed, and save interpretations in
6542 -- case operands are overloaded.
6544 Arg1 := Convert_To (Typ, Left_Opnd (N));
6545 Arg2 := Convert_To (Typ, Right_Opnd (N));
6547 if Nkind (Arg1) = N_Type_Conversion then
6548 Save_Interps (Left_Opnd (N), Expression (Arg1));
6550 Save_Interps (Left_Opnd (N), Arg1);
6553 if Nkind (Arg2) = N_Type_Conversion then
6554 Save_Interps (Right_Opnd (N), Expression (Arg2));
6556 Save_Interps (Right_Opnd (N), Arg2);
6559 Rewrite (Left_Opnd (N), Arg1);
6560 Rewrite (Right_Opnd (N), Arg2);
6563 Resolve_Arithmetic_Op (N, Typ);
6566 Resolve_Arithmetic_Op (N, Typ);
6568 end Resolve_Intrinsic_Operator;
6570 --------------------------------------
6571 -- Resolve_Intrinsic_Unary_Operator --
6572 --------------------------------------
6574 procedure Resolve_Intrinsic_Unary_Operator
6578 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6584 while Scope (Op) /= Standard_Standard loop
6586 pragma Assert (Present (Op));
6591 if Is_Private_Type (Typ) then
6592 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6593 Save_Interps (Right_Opnd (N), Expression (Arg2));
6595 Set_Right_Opnd (N, Arg2);
6597 Set_Etype (N, Btyp);
6598 Rewrite (N, Unchecked_Convert_To (Typ, N));
6602 Resolve_Unary_Op (N, Typ);
6604 end Resolve_Intrinsic_Unary_Operator;
6606 ------------------------
6607 -- Resolve_Logical_Op --
6608 ------------------------
6610 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6612 N_Opr : constant Node_Kind := Nkind (N);
6615 -- Predefined operations on scalar types yield the base type. On the
6616 -- other hand, logical operations on arrays yield the type of the
6617 -- arguments (and the context).
6619 if Is_Array_Type (Typ) then
6622 B_Typ := Base_Type (Typ);
6625 -- The following test is required because the operands of the operation
6626 -- may be literals, in which case the resulting type appears to be
6627 -- compatible with a signed integer type, when in fact it is compatible
6628 -- only with modular types. If the context itself is universal, the
6629 -- operation is illegal.
6631 if not Valid_Boolean_Arg (Typ) then
6632 Error_Msg_N ("invalid context for logical operation", N);
6633 Set_Etype (N, Any_Type);
6636 elsif Typ = Any_Modular then
6638 ("no modular type available in this context", N);
6639 Set_Etype (N, Any_Type);
6641 elsif Is_Modular_Integer_Type (Typ)
6642 and then Etype (Left_Opnd (N)) = Universal_Integer
6643 and then Etype (Right_Opnd (N)) = Universal_Integer
6645 Check_For_Visible_Operator (N, B_Typ);
6648 Resolve (Left_Opnd (N), B_Typ);
6649 Resolve (Right_Opnd (N), B_Typ);
6651 Check_Unset_Reference (Left_Opnd (N));
6652 Check_Unset_Reference (Right_Opnd (N));
6654 Set_Etype (N, B_Typ);
6655 Generate_Operator_Reference (N, B_Typ);
6656 Eval_Logical_Op (N);
6658 -- Check for violation of restriction No_Direct_Boolean_Operators
6659 -- if the operator was not eliminated by the Eval_Logical_Op call.
6661 if Nkind (N) = N_Opr
6662 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
6664 Check_Restriction (No_Direct_Boolean_Operators, N);
6666 end Resolve_Logical_Op;
6668 ---------------------------
6669 -- Resolve_Membership_Op --
6670 ---------------------------
6672 -- The context can only be a boolean type, and does not determine
6673 -- the arguments. Arguments should be unambiguous, but the preference
6674 -- rule for universal types applies.
6676 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6677 pragma Warnings (Off, Typ);
6679 L : constant Node_Id := Left_Opnd (N);
6680 R : constant Node_Id := Right_Opnd (N);
6684 if L = Error or else R = Error then
6688 if not Is_Overloaded (R)
6690 (Etype (R) = Universal_Integer or else
6691 Etype (R) = Universal_Real)
6692 and then Is_Overloaded (L)
6696 -- Ada 2005 (AI-251): Support the following case:
6698 -- type I is interface;
6699 -- type T is tagged ...
6701 -- function Test (O : I'Class) is
6703 -- return O in T'Class.
6706 -- In this case we have nothing else to do. The membership test will be
6707 -- done at run-time.
6709 elsif Ada_Version >= Ada_05
6710 and then Is_Class_Wide_Type (Etype (L))
6711 and then Is_Interface (Etype (L))
6712 and then Is_Class_Wide_Type (Etype (R))
6713 and then not Is_Interface (Etype (R))
6718 T := Intersect_Types (L, R);
6722 Check_Unset_Reference (L);
6724 if Nkind (R) = N_Range
6725 and then not Is_Scalar_Type (T)
6727 Error_Msg_N ("scalar type required for range", R);
6730 if Is_Entity_Name (R) then
6731 Freeze_Expression (R);
6734 Check_Unset_Reference (R);
6737 Eval_Membership_Op (N);
6738 end Resolve_Membership_Op;
6744 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6745 Loc : constant Source_Ptr := Sloc (N);
6748 -- Handle restriction against anonymous null access values This
6749 -- restriction can be turned off using -gnatdj.
6751 -- Ada 2005 (AI-231): Remove restriction
6753 if Ada_Version < Ada_05
6754 and then not Debug_Flag_J
6755 and then Ekind (Typ) = E_Anonymous_Access_Type
6756 and then Comes_From_Source (N)
6758 -- In the common case of a call which uses an explicitly null value
6759 -- for an access parameter, give specialized error message.
6761 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6765 ("null is not allowed as argument for an access parameter", N);
6767 -- Standard message for all other cases (are there any?)
6771 ("null cannot be of an anonymous access type", N);
6775 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6776 -- assignment to a null-excluding object
6778 if Ada_Version >= Ada_05
6779 and then Can_Never_Be_Null (Typ)
6780 and then Nkind (Parent (N)) = N_Assignment_Statement
6782 if not Inside_Init_Proc then
6784 (Compile_Time_Constraint_Error (N,
6785 "(Ada 2005) null not allowed in null-excluding objects?"),
6786 Make_Raise_Constraint_Error (Loc,
6787 Reason => CE_Access_Check_Failed));
6790 Make_Raise_Constraint_Error (Loc,
6791 Reason => CE_Access_Check_Failed));
6795 -- In a distributed context, null for a remote access to subprogram may
6796 -- need to be replaced with a special record aggregate. In this case,
6797 -- return after having done the transformation.
6799 if (Ekind (Typ) = E_Record_Type
6800 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6801 and then Remote_AST_Null_Value (N, Typ)
6806 -- The null literal takes its type from the context
6811 -----------------------
6812 -- Resolve_Op_Concat --
6813 -----------------------
6815 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6817 -- We wish to avoid deep recursion, because concatenations are often
6818 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6819 -- operands nonrecursively until we find something that is not a simple
6820 -- concatenation (A in this case). We resolve that, and then walk back
6821 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6822 -- to do the rest of the work at each level. The Parent pointers allow
6823 -- us to avoid recursion, and thus avoid running out of memory. See also
6824 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6830 -- The following code is equivalent to:
6832 -- Resolve_Op_Concat_First (NN, Typ);
6833 -- Resolve_Op_Concat_Arg (N, ...);
6834 -- Resolve_Op_Concat_Rest (N, Typ);
6836 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6837 -- operand is a concatenation.
6839 -- Walk down left operands
6842 Resolve_Op_Concat_First (NN, Typ);
6843 Op1 := Left_Opnd (NN);
6844 exit when not (Nkind (Op1) = N_Op_Concat
6845 and then not Is_Array_Type (Component_Type (Typ))
6846 and then Entity (Op1) = Entity (NN));
6850 -- Now (given the above example) NN is A&B and Op1 is A
6852 -- First resolve Op1 ...
6854 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6856 -- ... then walk NN back up until we reach N (where we started), calling
6857 -- Resolve_Op_Concat_Rest along the way.
6860 Resolve_Op_Concat_Rest (NN, Typ);
6864 end Resolve_Op_Concat;
6866 ---------------------------
6867 -- Resolve_Op_Concat_Arg --
6868 ---------------------------
6870 procedure Resolve_Op_Concat_Arg
6876 Btyp : constant Entity_Id := Base_Type (Typ);
6881 or else (not Is_Overloaded (Arg)
6882 and then Etype (Arg) /= Any_Composite
6883 and then Covers (Component_Type (Typ), Etype (Arg)))
6885 Resolve (Arg, Component_Type (Typ));
6887 Resolve (Arg, Btyp);
6890 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6891 if Nkind (Arg) = N_Aggregate
6892 and then Is_Composite_Type (Component_Type (Typ))
6894 if Is_Private_Type (Component_Type (Typ)) then
6895 Resolve (Arg, Btyp);
6897 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6898 Set_Etype (Arg, Any_Type);
6902 if Is_Overloaded (Arg)
6903 and then Has_Compatible_Type (Arg, Typ)
6904 and then Etype (Arg) /= Any_Type
6912 Get_First_Interp (Arg, I, It);
6914 Get_Next_Interp (I, It);
6916 -- Special-case the error message when the overloading is
6917 -- caused by a function that yields an array and can be
6918 -- called without parameters.
6920 if It.Nam = Func then
6921 Error_Msg_Sloc := Sloc (Func);
6922 Error_Msg_N ("ambiguous call to function#", Arg);
6924 ("\\interpretation as call yields&", Arg, Typ);
6926 ("\\interpretation as indexing of call yields&",
6927 Arg, Component_Type (Typ));
6931 ("ambiguous operand for concatenation!", Arg);
6932 Get_First_Interp (Arg, I, It);
6933 while Present (It.Nam) loop
6934 Error_Msg_Sloc := Sloc (It.Nam);
6936 if Base_Type (It.Typ) = Base_Type (Typ)
6937 or else Base_Type (It.Typ) =
6938 Base_Type (Component_Type (Typ))
6940 Error_Msg_N -- CODEFIX
6941 ("\\possible interpretation#", Arg);
6944 Get_Next_Interp (I, It);
6950 Resolve (Arg, Component_Type (Typ));
6952 if Nkind (Arg) = N_String_Literal then
6953 Set_Etype (Arg, Component_Type (Typ));
6956 if Arg = Left_Opnd (N) then
6957 Set_Is_Component_Left_Opnd (N);
6959 Set_Is_Component_Right_Opnd (N);
6964 Resolve (Arg, Btyp);
6967 Check_Unset_Reference (Arg);
6968 end Resolve_Op_Concat_Arg;
6970 -----------------------------
6971 -- Resolve_Op_Concat_First --
6972 -----------------------------
6974 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
6975 Btyp : constant Entity_Id := Base_Type (Typ);
6976 Op1 : constant Node_Id := Left_Opnd (N);
6977 Op2 : constant Node_Id := Right_Opnd (N);
6980 -- The parser folds an enormous sequence of concatenations of string
6981 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
6982 -- in the right operand. If the expression resolves to a predefined "&"
6983 -- operator, all is well. Otherwise, the parser's folding is wrong, so
6984 -- we give an error. See P_Simple_Expression in Par.Ch4.
6986 if Nkind (Op2) = N_String_Literal
6987 and then Is_Folded_In_Parser (Op2)
6988 and then Ekind (Entity (N)) = E_Function
6990 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
6991 and then String_Length (Strval (Op1)) = 0);
6992 Error_Msg_N ("too many user-defined concatenations", N);
6996 Set_Etype (N, Btyp);
6998 if Is_Limited_Composite (Btyp) then
6999 Error_Msg_N ("concatenation not available for limited array", N);
7000 Explain_Limited_Type (Btyp, N);
7002 end Resolve_Op_Concat_First;
7004 ----------------------------
7005 -- Resolve_Op_Concat_Rest --
7006 ----------------------------
7008 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7009 Op1 : constant Node_Id := Left_Opnd (N);
7010 Op2 : constant Node_Id := Right_Opnd (N);
7013 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7015 Generate_Operator_Reference (N, Typ);
7017 if Is_String_Type (Typ) then
7018 Eval_Concatenation (N);
7021 -- If this is not a static concatenation, but the result is a string
7022 -- type (and not an array of strings) ensure that static string operands
7023 -- have their subtypes properly constructed.
7025 if Nkind (N) /= N_String_Literal
7026 and then Is_Character_Type (Component_Type (Typ))
7028 Set_String_Literal_Subtype (Op1, Typ);
7029 Set_String_Literal_Subtype (Op2, Typ);
7031 end Resolve_Op_Concat_Rest;
7033 ----------------------
7034 -- Resolve_Op_Expon --
7035 ----------------------
7037 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7038 B_Typ : constant Entity_Id := Base_Type (Typ);
7041 -- Catch attempts to do fixed-point exponentiation with universal
7042 -- operands, which is a case where the illegality is not caught during
7043 -- normal operator analysis.
7045 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7046 Error_Msg_N ("exponentiation not available for fixed point", N);
7050 if Comes_From_Source (N)
7051 and then Ekind (Entity (N)) = E_Function
7052 and then Is_Imported (Entity (N))
7053 and then Is_Intrinsic_Subprogram (Entity (N))
7055 Resolve_Intrinsic_Operator (N, Typ);
7059 if Etype (Left_Opnd (N)) = Universal_Integer
7060 or else Etype (Left_Opnd (N)) = Universal_Real
7062 Check_For_Visible_Operator (N, B_Typ);
7065 -- We do the resolution using the base type, because intermediate values
7066 -- in expressions always are of the base type, not a subtype of it.
7068 Resolve (Left_Opnd (N), B_Typ);
7069 Resolve (Right_Opnd (N), Standard_Integer);
7071 Check_Unset_Reference (Left_Opnd (N));
7072 Check_Unset_Reference (Right_Opnd (N));
7074 Set_Etype (N, B_Typ);
7075 Generate_Operator_Reference (N, B_Typ);
7078 -- Set overflow checking bit. Much cleverer code needed here eventually
7079 -- and perhaps the Resolve routines should be separated for the various
7080 -- arithmetic operations, since they will need different processing. ???
7082 if Nkind (N) in N_Op then
7083 if not Overflow_Checks_Suppressed (Etype (N)) then
7084 Enable_Overflow_Check (N);
7087 end Resolve_Op_Expon;
7089 --------------------
7090 -- Resolve_Op_Not --
7091 --------------------
7093 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7096 function Parent_Is_Boolean return Boolean;
7097 -- This function determines if the parent node is a boolean operator
7098 -- or operation (comparison op, membership test, or short circuit form)
7099 -- and the not in question is the left operand of this operation.
7100 -- Note that if the not is in parens, then false is returned.
7102 -----------------------
7103 -- Parent_Is_Boolean --
7104 -----------------------
7106 function Parent_Is_Boolean return Boolean is
7108 if Paren_Count (N) /= 0 then
7112 case Nkind (Parent (N)) is
7127 return Left_Opnd (Parent (N)) = N;
7133 end Parent_Is_Boolean;
7135 -- Start of processing for Resolve_Op_Not
7138 -- Predefined operations on scalar types yield the base type. On the
7139 -- other hand, logical operations on arrays yield the type of the
7140 -- arguments (and the context).
7142 if Is_Array_Type (Typ) then
7145 B_Typ := Base_Type (Typ);
7148 -- Straightforward case of incorrect arguments
7150 if not Valid_Boolean_Arg (Typ) then
7151 Error_Msg_N ("invalid operand type for operator&", N);
7152 Set_Etype (N, Any_Type);
7155 -- Special case of probable missing parens
7157 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7158 if Parent_Is_Boolean then
7160 ("operand of not must be enclosed in parentheses",
7164 ("no modular type available in this context", N);
7167 Set_Etype (N, Any_Type);
7170 -- OK resolution of not
7173 -- Warn if non-boolean types involved. This is a case like not a < b
7174 -- where a and b are modular, where we will get (not a) < b and most
7175 -- likely not (a < b) was intended.
7177 if Warn_On_Questionable_Missing_Parens
7178 and then not Is_Boolean_Type (Typ)
7179 and then Parent_Is_Boolean
7181 Error_Msg_N ("?not expression should be parenthesized here!", N);
7184 -- Warn on double negation if checking redundant constructs
7186 if Warn_On_Redundant_Constructs
7187 and then Comes_From_Source (N)
7188 and then Comes_From_Source (Right_Opnd (N))
7189 and then Root_Type (Typ) = Standard_Boolean
7190 and then Nkind (Right_Opnd (N)) = N_Op_Not
7192 Error_Msg_N ("redundant double negation?", N);
7195 -- Complete resolution and evaluation of NOT
7197 Resolve (Right_Opnd (N), B_Typ);
7198 Check_Unset_Reference (Right_Opnd (N));
7199 Set_Etype (N, B_Typ);
7200 Generate_Operator_Reference (N, B_Typ);
7205 -----------------------------
7206 -- Resolve_Operator_Symbol --
7207 -----------------------------
7209 -- Nothing to be done, all resolved already
7211 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7212 pragma Warnings (Off, N);
7213 pragma Warnings (Off, Typ);
7217 end Resolve_Operator_Symbol;
7219 ----------------------------------
7220 -- Resolve_Qualified_Expression --
7221 ----------------------------------
7223 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7224 pragma Warnings (Off, Typ);
7226 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7227 Expr : constant Node_Id := Expression (N);
7230 Resolve (Expr, Target_Typ);
7232 -- A qualified expression requires an exact match of the type,
7233 -- class-wide matching is not allowed. However, if the qualifying
7234 -- type is specific and the expression has a class-wide type, it
7235 -- may still be okay, since it can be the result of the expansion
7236 -- of a call to a dispatching function, so we also have to check
7237 -- class-wideness of the type of the expression's original node.
7239 if (Is_Class_Wide_Type (Target_Typ)
7241 (Is_Class_Wide_Type (Etype (Expr))
7242 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7243 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7245 Wrong_Type (Expr, Target_Typ);
7248 -- If the target type is unconstrained, then we reset the type of
7249 -- the result from the type of the expression. For other cases, the
7250 -- actual subtype of the expression is the target type.
7252 if Is_Composite_Type (Target_Typ)
7253 and then not Is_Constrained (Target_Typ)
7255 Set_Etype (N, Etype (Expr));
7258 Eval_Qualified_Expression (N);
7259 end Resolve_Qualified_Expression;
7265 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7266 L : constant Node_Id := Low_Bound (N);
7267 H : constant Node_Id := High_Bound (N);
7274 Check_Unset_Reference (L);
7275 Check_Unset_Reference (H);
7277 -- We have to check the bounds for being within the base range as
7278 -- required for a non-static context. Normally this is automatic and
7279 -- done as part of evaluating expressions, but the N_Range node is an
7280 -- exception, since in GNAT we consider this node to be a subexpression,
7281 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7282 -- this, but that would put the test on the main evaluation path for
7285 Check_Non_Static_Context (L);
7286 Check_Non_Static_Context (H);
7288 -- Check for an ambiguous range over character literals. This will
7289 -- happen with a membership test involving only literals.
7291 if Typ = Any_Character then
7292 Ambiguous_Character (L);
7293 Set_Etype (N, Any_Type);
7297 -- If bounds are static, constant-fold them, so size computations
7298 -- are identical between front-end and back-end. Do not perform this
7299 -- transformation while analyzing generic units, as type information
7300 -- would then be lost when reanalyzing the constant node in the
7303 if Is_Discrete_Type (Typ) and then Expander_Active then
7304 if Is_OK_Static_Expression (L) then
7305 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7308 if Is_OK_Static_Expression (H) then
7309 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7314 --------------------------
7315 -- Resolve_Real_Literal --
7316 --------------------------
7318 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7319 Actual_Typ : constant Entity_Id := Etype (N);
7322 -- Special processing for fixed-point literals to make sure that the
7323 -- value is an exact multiple of small where this is required. We
7324 -- skip this for the universal real case, and also for generic types.
7326 if Is_Fixed_Point_Type (Typ)
7327 and then Typ /= Universal_Fixed
7328 and then Typ /= Any_Fixed
7329 and then not Is_Generic_Type (Typ)
7332 Val : constant Ureal := Realval (N);
7333 Cintr : constant Ureal := Val / Small_Value (Typ);
7334 Cint : constant Uint := UR_Trunc (Cintr);
7335 Den : constant Uint := Norm_Den (Cintr);
7339 -- Case of literal is not an exact multiple of the Small
7343 -- For a source program literal for a decimal fixed-point
7344 -- type, this is statically illegal (RM 4.9(36)).
7346 if Is_Decimal_Fixed_Point_Type (Typ)
7347 and then Actual_Typ = Universal_Real
7348 and then Comes_From_Source (N)
7350 Error_Msg_N ("value has extraneous low order digits", N);
7353 -- Generate a warning if literal from source
7355 if Is_Static_Expression (N)
7356 and then Warn_On_Bad_Fixed_Value
7359 ("?static fixed-point value is not a multiple of Small!",
7363 -- Replace literal by a value that is the exact representation
7364 -- of a value of the type, i.e. a multiple of the small value,
7365 -- by truncation, since Machine_Rounds is false for all GNAT
7366 -- fixed-point types (RM 4.9(38)).
7368 Stat := Is_Static_Expression (N);
7370 Make_Real_Literal (Sloc (N),
7371 Realval => Small_Value (Typ) * Cint));
7373 Set_Is_Static_Expression (N, Stat);
7376 -- In all cases, set the corresponding integer field
7378 Set_Corresponding_Integer_Value (N, Cint);
7382 -- Now replace the actual type by the expected type as usual
7385 Eval_Real_Literal (N);
7386 end Resolve_Real_Literal;
7388 -----------------------
7389 -- Resolve_Reference --
7390 -----------------------
7392 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7393 P : constant Node_Id := Prefix (N);
7396 -- Replace general access with specific type
7398 if Ekind (Etype (N)) = E_Allocator_Type then
7399 Set_Etype (N, Base_Type (Typ));
7402 Resolve (P, Designated_Type (Etype (N)));
7404 -- If we are taking the reference of a volatile entity, then treat
7405 -- it as a potential modification of this entity. This is much too
7406 -- conservative, but is necessary because remove side effects can
7407 -- result in transformations of normal assignments into reference
7408 -- sequences that otherwise fail to notice the modification.
7410 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7411 Note_Possible_Modification (P, Sure => False);
7413 end Resolve_Reference;
7415 --------------------------------
7416 -- Resolve_Selected_Component --
7417 --------------------------------
7419 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7421 Comp1 : Entity_Id := Empty; -- prevent junk warning
7422 P : constant Node_Id := Prefix (N);
7423 S : constant Node_Id := Selector_Name (N);
7424 T : Entity_Id := Etype (P);
7426 I1 : Interp_Index := 0; -- prevent junk warning
7431 function Init_Component return Boolean;
7432 -- Check whether this is the initialization of a component within an
7433 -- init proc (by assignment or call to another init proc). If true,
7434 -- there is no need for a discriminant check.
7436 --------------------
7437 -- Init_Component --
7438 --------------------
7440 function Init_Component return Boolean is
7442 return Inside_Init_Proc
7443 and then Nkind (Prefix (N)) = N_Identifier
7444 and then Chars (Prefix (N)) = Name_uInit
7445 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7448 -- Start of processing for Resolve_Selected_Component
7451 if Is_Overloaded (P) then
7453 -- Use the context type to select the prefix that has a selector
7454 -- of the correct name and type.
7457 Get_First_Interp (P, I, It);
7459 Search : while Present (It.Typ) loop
7460 if Is_Access_Type (It.Typ) then
7461 T := Designated_Type (It.Typ);
7466 if Is_Record_Type (T) then
7468 -- The visible components of a class-wide type are those of
7471 if Is_Class_Wide_Type (T) then
7475 Comp := First_Entity (T);
7476 while Present (Comp) loop
7477 if Chars (Comp) = Chars (S)
7478 and then Covers (Etype (Comp), Typ)
7487 It := Disambiguate (P, I1, I, Any_Type);
7489 if It = No_Interp then
7491 ("ambiguous prefix for selected component", N);
7498 -- There may be an implicit dereference. Retrieve
7499 -- designated record type.
7501 if Is_Access_Type (It1.Typ) then
7502 T := Designated_Type (It1.Typ);
7507 if Scope (Comp1) /= T then
7509 -- Resolution chooses the new interpretation.
7510 -- Find the component with the right name.
7512 Comp1 := First_Entity (T);
7513 while Present (Comp1)
7514 and then Chars (Comp1) /= Chars (S)
7516 Comp1 := Next_Entity (Comp1);
7525 Comp := Next_Entity (Comp);
7530 Get_Next_Interp (I, It);
7533 Resolve (P, It1.Typ);
7535 Set_Entity_With_Style_Check (S, Comp1);
7538 -- Resolve prefix with its type
7543 -- Generate cross-reference. We needed to wait until full overloading
7544 -- resolution was complete to do this, since otherwise we can't tell if
7545 -- we are an Lvalue of not.
7547 if May_Be_Lvalue (N) then
7548 Generate_Reference (Entity (S), S, 'm');
7550 Generate_Reference (Entity (S), S, 'r');
7553 -- If prefix is an access type, the node will be transformed into an
7554 -- explicit dereference during expansion. The type of the node is the
7555 -- designated type of that of the prefix.
7557 if Is_Access_Type (Etype (P)) then
7558 T := Designated_Type (Etype (P));
7559 Check_Fully_Declared_Prefix (T, P);
7564 if Has_Discriminants (T)
7565 and then (Ekind (Entity (S)) = E_Component
7567 Ekind (Entity (S)) = E_Discriminant)
7568 and then Present (Original_Record_Component (Entity (S)))
7569 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7570 and then Present (Discriminant_Checking_Func
7571 (Original_Record_Component (Entity (S))))
7572 and then not Discriminant_Checks_Suppressed (T)
7573 and then not Init_Component
7575 Set_Do_Discriminant_Check (N);
7578 if Ekind (Entity (S)) = E_Void then
7579 Error_Msg_N ("premature use of component", S);
7582 -- If the prefix is a record conversion, this may be a renamed
7583 -- discriminant whose bounds differ from those of the original
7584 -- one, so we must ensure that a range check is performed.
7586 if Nkind (P) = N_Type_Conversion
7587 and then Ekind (Entity (S)) = E_Discriminant
7588 and then Is_Discrete_Type (Typ)
7590 Set_Etype (N, Base_Type (Typ));
7593 -- Note: No Eval processing is required, because the prefix is of a
7594 -- record type, or protected type, and neither can possibly be static.
7596 end Resolve_Selected_Component;
7602 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7603 B_Typ : constant Entity_Id := Base_Type (Typ);
7604 L : constant Node_Id := Left_Opnd (N);
7605 R : constant Node_Id := Right_Opnd (N);
7608 -- We do the resolution using the base type, because intermediate values
7609 -- in expressions always are of the base type, not a subtype of it.
7612 Resolve (R, Standard_Natural);
7614 Check_Unset_Reference (L);
7615 Check_Unset_Reference (R);
7617 Set_Etype (N, B_Typ);
7618 Generate_Operator_Reference (N, B_Typ);
7622 ---------------------------
7623 -- Resolve_Short_Circuit --
7624 ---------------------------
7626 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7627 B_Typ : constant Entity_Id := Base_Type (Typ);
7628 L : constant Node_Id := Left_Opnd (N);
7629 R : constant Node_Id := Right_Opnd (N);
7635 -- Check for issuing warning for always False assert/check, this happens
7636 -- when assertions are turned off, in which case the pragma Assert/Check
7637 -- was transformed into:
7639 -- if False and then <condition> then ...
7641 -- and we detect this pattern
7643 if Warn_On_Assertion_Failure
7644 and then Is_Entity_Name (R)
7645 and then Entity (R) = Standard_False
7646 and then Nkind (Parent (N)) = N_If_Statement
7647 and then Nkind (N) = N_And_Then
7648 and then Is_Entity_Name (L)
7649 and then Entity (L) = Standard_False
7652 Orig : constant Node_Id := Original_Node (Parent (N));
7655 if Nkind (Orig) = N_Pragma
7656 and then Pragma_Name (Orig) = Name_Assert
7658 -- Don't want to warn if original condition is explicit False
7661 Expr : constant Node_Id :=
7664 (First (Pragma_Argument_Associations (Orig))));
7666 if Is_Entity_Name (Expr)
7667 and then Entity (Expr) = Standard_False
7671 -- Issue warning. Note that we don't want to make this
7672 -- an unconditional warning, because if the assert is
7673 -- within deleted code we do not want the warning. But
7674 -- we do not want the deletion of the IF/AND-THEN to
7675 -- take this message with it. We achieve this by making
7676 -- sure that the expanded code points to the Sloc of
7677 -- the expression, not the original pragma.
7679 Error_Msg_N ("?assertion would fail at run-time", Orig);
7683 -- Similar processing for Check pragma
7685 elsif Nkind (Orig) = N_Pragma
7686 and then Pragma_Name (Orig) = Name_Check
7688 -- Don't want to warn if original condition is explicit False
7691 Expr : constant Node_Id :=
7695 (Pragma_Argument_Associations (Orig)))));
7697 if Is_Entity_Name (Expr)
7698 and then Entity (Expr) = Standard_False
7702 Error_Msg_N ("?check would fail at run-time", Orig);
7709 -- Continue with processing of short circuit
7711 Check_Unset_Reference (L);
7712 Check_Unset_Reference (R);
7714 Set_Etype (N, B_Typ);
7715 Eval_Short_Circuit (N);
7716 end Resolve_Short_Circuit;
7722 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7723 Name : constant Node_Id := Prefix (N);
7724 Drange : constant Node_Id := Discrete_Range (N);
7725 Array_Type : Entity_Id := Empty;
7729 if Is_Overloaded (Name) then
7731 -- Use the context type to select the prefix that yields the correct
7736 I1 : Interp_Index := 0;
7738 P : constant Node_Id := Prefix (N);
7739 Found : Boolean := False;
7742 Get_First_Interp (P, I, It);
7743 while Present (It.Typ) loop
7744 if (Is_Array_Type (It.Typ)
7745 and then Covers (Typ, It.Typ))
7746 or else (Is_Access_Type (It.Typ)
7747 and then Is_Array_Type (Designated_Type (It.Typ))
7748 and then Covers (Typ, Designated_Type (It.Typ)))
7751 It := Disambiguate (P, I1, I, Any_Type);
7753 if It = No_Interp then
7754 Error_Msg_N ("ambiguous prefix for slicing", N);
7759 Array_Type := It.Typ;
7764 Array_Type := It.Typ;
7769 Get_Next_Interp (I, It);
7774 Array_Type := Etype (Name);
7777 Resolve (Name, Array_Type);
7779 if Is_Access_Type (Array_Type) then
7780 Apply_Access_Check (N);
7781 Array_Type := Designated_Type (Array_Type);
7783 -- If the prefix is an access to an unconstrained array, we must use
7784 -- the actual subtype of the object to perform the index checks. The
7785 -- object denoted by the prefix is implicit in the node, so we build
7786 -- an explicit representation for it in order to compute the actual
7789 if not Is_Constrained (Array_Type) then
7790 Remove_Side_Effects (Prefix (N));
7793 Obj : constant Node_Id :=
7794 Make_Explicit_Dereference (Sloc (N),
7795 Prefix => New_Copy_Tree (Prefix (N)));
7797 Set_Etype (Obj, Array_Type);
7798 Set_Parent (Obj, Parent (N));
7799 Array_Type := Get_Actual_Subtype (Obj);
7803 elsif Is_Entity_Name (Name)
7804 or else (Nkind (Name) = N_Function_Call
7805 and then not Is_Constrained (Etype (Name)))
7807 Array_Type := Get_Actual_Subtype (Name);
7809 -- If the name is a selected component that depends on discriminants,
7810 -- build an actual subtype for it. This can happen only when the name
7811 -- itself is overloaded; otherwise the actual subtype is created when
7812 -- the selected component is analyzed.
7814 elsif Nkind (Name) = N_Selected_Component
7815 and then Full_Analysis
7816 and then Depends_On_Discriminant (First_Index (Array_Type))
7819 Act_Decl : constant Node_Id :=
7820 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7822 Insert_Action (N, Act_Decl);
7823 Array_Type := Defining_Identifier (Act_Decl);
7827 -- If name was overloaded, set slice type correctly now
7829 Set_Etype (N, Array_Type);
7831 -- If the range is specified by a subtype mark, no resolution is
7832 -- necessary. Else resolve the bounds, and apply needed checks.
7834 if not Is_Entity_Name (Drange) then
7835 Index := First_Index (Array_Type);
7836 Resolve (Drange, Base_Type (Etype (Index)));
7838 if Nkind (Drange) = N_Range
7840 -- Do not apply the range check to nodes associated with the
7841 -- frontend expansion of the dispatch table. We first check
7842 -- if Ada.Tags is already loaded to void the addition of an
7843 -- undesired dependence on such run-time unit.
7846 (not Tagged_Type_Expansion
7848 (RTU_Loaded (Ada_Tags)
7849 and then Nkind (Prefix (N)) = N_Selected_Component
7850 and then Present (Entity (Selector_Name (Prefix (N))))
7851 and then Entity (Selector_Name (Prefix (N))) =
7852 RTE_Record_Component (RE_Prims_Ptr)))
7854 Apply_Range_Check (Drange, Etype (Index));
7858 Set_Slice_Subtype (N);
7860 if Nkind (Drange) = N_Range then
7861 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7862 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7868 ----------------------------
7869 -- Resolve_String_Literal --
7870 ----------------------------
7872 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7873 C_Typ : constant Entity_Id := Component_Type (Typ);
7874 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7875 Loc : constant Source_Ptr := Sloc (N);
7876 Str : constant String_Id := Strval (N);
7877 Strlen : constant Nat := String_Length (Str);
7878 Subtype_Id : Entity_Id;
7879 Need_Check : Boolean;
7882 -- For a string appearing in a concatenation, defer creation of the
7883 -- string_literal_subtype until the end of the resolution of the
7884 -- concatenation, because the literal may be constant-folded away. This
7885 -- is a useful optimization for long concatenation expressions.
7887 -- If the string is an aggregate built for a single character (which
7888 -- happens in a non-static context) or a is null string to which special
7889 -- checks may apply, we build the subtype. Wide strings must also get a
7890 -- string subtype if they come from a one character aggregate. Strings
7891 -- generated by attributes might be static, but it is often hard to
7892 -- determine whether the enclosing context is static, so we generate
7893 -- subtypes for them as well, thus losing some rarer optimizations ???
7894 -- Same for strings that come from a static conversion.
7897 (Strlen = 0 and then Typ /= Standard_String)
7898 or else Nkind (Parent (N)) /= N_Op_Concat
7899 or else (N /= Left_Opnd (Parent (N))
7900 and then N /= Right_Opnd (Parent (N)))
7901 or else ((Typ = Standard_Wide_String
7902 or else Typ = Standard_Wide_Wide_String)
7903 and then Nkind (Original_Node (N)) /= N_String_Literal);
7905 -- If the resolving type is itself a string literal subtype, we can just
7906 -- reuse it, since there is no point in creating another.
7908 if Ekind (Typ) = E_String_Literal_Subtype then
7911 elsif Nkind (Parent (N)) = N_Op_Concat
7912 and then not Need_Check
7913 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7914 N_Attribute_Reference,
7915 N_Qualified_Expression,
7920 -- Otherwise we must create a string literal subtype. Note that the
7921 -- whole idea of string literal subtypes is simply to avoid the need
7922 -- for building a full fledged array subtype for each literal.
7925 Set_String_Literal_Subtype (N, Typ);
7926 Subtype_Id := Etype (N);
7929 if Nkind (Parent (N)) /= N_Op_Concat
7932 Set_Etype (N, Subtype_Id);
7933 Eval_String_Literal (N);
7936 if Is_Limited_Composite (Typ)
7937 or else Is_Private_Composite (Typ)
7939 Error_Msg_N ("string literal not available for private array", N);
7940 Set_Etype (N, Any_Type);
7944 -- The validity of a null string has been checked in the call to
7945 -- Eval_String_Literal.
7950 -- Always accept string literal with component type Any_Character, which
7951 -- occurs in error situations and in comparisons of literals, both of
7952 -- which should accept all literals.
7954 elsif R_Typ = Any_Character then
7957 -- If the type is bit-packed, then we always transform the string
7958 -- literal into a full fledged aggregate.
7960 elsif Is_Bit_Packed_Array (Typ) then
7963 -- Deal with cases of Wide_Wide_String, Wide_String, and String
7966 -- For Standard.Wide_Wide_String, or any other type whose component
7967 -- type is Standard.Wide_Wide_Character, we know that all the
7968 -- characters in the string must be acceptable, since the parser
7969 -- accepted the characters as valid character literals.
7971 if R_Typ = Standard_Wide_Wide_Character then
7974 -- For the case of Standard.String, or any other type whose component
7975 -- type is Standard.Character, we must make sure that there are no
7976 -- wide characters in the string, i.e. that it is entirely composed
7977 -- of characters in range of type Character.
7979 -- If the string literal is the result of a static concatenation, the
7980 -- test has already been performed on the components, and need not be
7983 elsif R_Typ = Standard_Character
7984 and then Nkind (Original_Node (N)) /= N_Op_Concat
7986 for J in 1 .. Strlen loop
7987 if not In_Character_Range (Get_String_Char (Str, J)) then
7989 -- If we are out of range, post error. This is one of the
7990 -- very few places that we place the flag in the middle of
7991 -- a token, right under the offending wide character. Not
7992 -- quite clear if this is right wrt wide character encoding
7993 -- sequences, but it's only an error message!
7996 ("literal out of range of type Standard.Character",
7997 Source_Ptr (Int (Loc) + J));
8002 -- For the case of Standard.Wide_String, or any other type whose
8003 -- component type is Standard.Wide_Character, we must make sure that
8004 -- there are no wide characters in the string, i.e. that it is
8005 -- entirely composed of characters in range of type Wide_Character.
8007 -- If the string literal is the result of a static concatenation,
8008 -- the test has already been performed on the components, and need
8011 elsif R_Typ = Standard_Wide_Character
8012 and then Nkind (Original_Node (N)) /= N_Op_Concat
8014 for J in 1 .. Strlen loop
8015 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8017 -- If we are out of range, post error. This is one of the
8018 -- very few places that we place the flag in the middle of
8019 -- a token, right under the offending wide character.
8021 -- This is not quite right, because characters in general
8022 -- will take more than one character position ???
8025 ("literal out of range of type Standard.Wide_Character",
8026 Source_Ptr (Int (Loc) + J));
8031 -- If the root type is not a standard character, then we will convert
8032 -- the string into an aggregate and will let the aggregate code do
8033 -- the checking. Standard Wide_Wide_Character is also OK here.
8039 -- See if the component type of the array corresponding to the string
8040 -- has compile time known bounds. If yes we can directly check
8041 -- whether the evaluation of the string will raise constraint error.
8042 -- Otherwise we need to transform the string literal into the
8043 -- corresponding character aggregate and let the aggregate
8044 -- code do the checking.
8046 if Is_Standard_Character_Type (R_Typ) then
8048 -- Check for the case of full range, where we are definitely OK
8050 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8054 -- Here the range is not the complete base type range, so check
8057 Comp_Typ_Lo : constant Node_Id :=
8058 Type_Low_Bound (Component_Type (Typ));
8059 Comp_Typ_Hi : constant Node_Id :=
8060 Type_High_Bound (Component_Type (Typ));
8065 if Compile_Time_Known_Value (Comp_Typ_Lo)
8066 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8068 for J in 1 .. Strlen loop
8069 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8071 if Char_Val < Expr_Value (Comp_Typ_Lo)
8072 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8074 Apply_Compile_Time_Constraint_Error
8075 (N, "character out of range?", CE_Range_Check_Failed,
8076 Loc => Source_Ptr (Int (Loc) + J));
8086 -- If we got here we meed to transform the string literal into the
8087 -- equivalent qualified positional array aggregate. This is rather
8088 -- heavy artillery for this situation, but it is hard work to avoid.
8091 Lits : constant List_Id := New_List;
8092 P : Source_Ptr := Loc + 1;
8096 -- Build the character literals, we give them source locations that
8097 -- correspond to the string positions, which is a bit tricky given
8098 -- the possible presence of wide character escape sequences.
8100 for J in 1 .. Strlen loop
8101 C := Get_String_Char (Str, J);
8102 Set_Character_Literal_Name (C);
8105 Make_Character_Literal (P,
8107 Char_Literal_Value => UI_From_CC (C)));
8109 if In_Character_Range (C) then
8112 -- Should we have a call to Skip_Wide here ???
8120 Make_Qualified_Expression (Loc,
8121 Subtype_Mark => New_Reference_To (Typ, Loc),
8123 Make_Aggregate (Loc, Expressions => Lits)));
8125 Analyze_And_Resolve (N, Typ);
8127 end Resolve_String_Literal;
8129 -----------------------------
8130 -- Resolve_Subprogram_Info --
8131 -----------------------------
8133 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8136 end Resolve_Subprogram_Info;
8138 -----------------------------
8139 -- Resolve_Type_Conversion --
8140 -----------------------------
8142 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8143 Conv_OK : constant Boolean := Conversion_OK (N);
8144 Operand : constant Node_Id := Expression (N);
8145 Operand_Typ : constant Entity_Id := Etype (Operand);
8146 Target_Typ : constant Entity_Id := Etype (N);
8153 and then not Valid_Conversion (N, Target_Typ, Operand)
8158 if Etype (Operand) = Any_Fixed then
8160 -- Mixed-mode operation involving a literal. Context must be a fixed
8161 -- type which is applied to the literal subsequently.
8163 if Is_Fixed_Point_Type (Typ) then
8164 Set_Etype (Operand, Universal_Real);
8166 elsif Is_Numeric_Type (Typ)
8167 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8168 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8170 Etype (Left_Opnd (Operand)) = Universal_Real)
8172 -- Return if expression is ambiguous
8174 if Unique_Fixed_Point_Type (N) = Any_Type then
8177 -- If nothing else, the available fixed type is Duration
8180 Set_Etype (Operand, Standard_Duration);
8183 -- Resolve the real operand with largest available precision
8185 if Etype (Right_Opnd (Operand)) = Universal_Real then
8186 Rop := New_Copy_Tree (Right_Opnd (Operand));
8188 Rop := New_Copy_Tree (Left_Opnd (Operand));
8191 Resolve (Rop, Universal_Real);
8193 -- If the operand is a literal (it could be a non-static and
8194 -- illegal exponentiation) check whether the use of Duration
8195 -- is potentially inaccurate.
8197 if Nkind (Rop) = N_Real_Literal
8198 and then Realval (Rop) /= Ureal_0
8199 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8202 ("?universal real operand can only " &
8203 "be interpreted as Duration!",
8206 ("\?precision will be lost in the conversion!", Rop);
8209 elsif Is_Numeric_Type (Typ)
8210 and then Nkind (Operand) in N_Op
8211 and then Unique_Fixed_Point_Type (N) /= Any_Type
8213 Set_Etype (Operand, Standard_Duration);
8216 Error_Msg_N ("invalid context for mixed mode operation", N);
8217 Set_Etype (Operand, Any_Type);
8224 -- Note: we do the Eval_Type_Conversion call before applying the
8225 -- required checks for a subtype conversion. This is important, since
8226 -- both are prepared under certain circumstances to change the type
8227 -- conversion to a constraint error node, but in the case of
8228 -- Eval_Type_Conversion this may reflect an illegality in the static
8229 -- case, and we would miss the illegality (getting only a warning
8230 -- message), if we applied the type conversion checks first.
8232 Eval_Type_Conversion (N);
8234 -- Even when evaluation is not possible, we may be able to simplify the
8235 -- conversion or its expression. This needs to be done before applying
8236 -- checks, since otherwise the checks may use the original expression
8237 -- and defeat the simplifications. This is specifically the case for
8238 -- elimination of the floating-point Truncation attribute in
8239 -- float-to-int conversions.
8241 Simplify_Type_Conversion (N);
8243 -- If after evaluation we still have a type conversion, then we may need
8244 -- to apply checks required for a subtype conversion.
8246 -- Skip these type conversion checks if universal fixed operands
8247 -- operands involved, since range checks are handled separately for
8248 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8250 if Nkind (N) = N_Type_Conversion
8251 and then not Is_Generic_Type (Root_Type (Target_Typ))
8252 and then Target_Typ /= Universal_Fixed
8253 and then Operand_Typ /= Universal_Fixed
8255 Apply_Type_Conversion_Checks (N);
8258 -- Issue warning for conversion of simple object to its own type. We
8259 -- have to test the original nodes, since they may have been rewritten
8260 -- by various optimizations.
8262 Orig_N := Original_Node (N);
8264 if Warn_On_Redundant_Constructs
8265 and then Comes_From_Source (Orig_N)
8266 and then Nkind (Orig_N) = N_Type_Conversion
8267 and then not In_Instance
8269 Orig_N := Original_Node (Expression (Orig_N));
8270 Orig_T := Target_Typ;
8272 -- If the node is part of a larger expression, the Target_Type
8273 -- may not be the original type of the node if the context is a
8274 -- condition. Recover original type to see if conversion is needed.
8276 if Is_Boolean_Type (Orig_T)
8277 and then Nkind (Parent (N)) in N_Op
8279 Orig_T := Etype (Parent (N));
8282 if Is_Entity_Name (Orig_N)
8284 (Etype (Entity (Orig_N)) = Orig_T
8286 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8287 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8289 Error_Msg_Node_2 := Orig_T;
8290 Error_Msg_NE -- CODEFIX
8291 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8295 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8296 -- No need to perform any interface conversion if the type of the
8297 -- expression coincides with the target type.
8299 if Ada_Version >= Ada_05
8300 and then Expander_Active
8301 and then Operand_Typ /= Target_Typ
8304 Opnd : Entity_Id := Operand_Typ;
8305 Target : Entity_Id := Target_Typ;
8308 if Is_Access_Type (Opnd) then
8309 Opnd := Directly_Designated_Type (Opnd);
8312 if Is_Access_Type (Target_Typ) then
8313 Target := Directly_Designated_Type (Target);
8316 if Opnd = Target then
8319 -- Conversion from interface type
8321 elsif Is_Interface (Opnd) then
8323 -- Ada 2005 (AI-217): Handle entities from limited views
8325 if From_With_Type (Opnd) then
8326 Error_Msg_Qual_Level := 99;
8327 Error_Msg_NE ("missing WITH clause on package &", N,
8328 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8330 ("type conversions require visibility of the full view",
8333 elsif From_With_Type (Target)
8335 (Is_Access_Type (Target_Typ)
8336 and then Present (Non_Limited_View (Etype (Target))))
8338 Error_Msg_Qual_Level := 99;
8339 Error_Msg_NE ("missing WITH clause on package &", N,
8340 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8342 ("type conversions require visibility of the full view",
8346 Expand_Interface_Conversion (N, Is_Static => False);
8349 -- Conversion to interface type
8351 elsif Is_Interface (Target) then
8355 if Ekind (Opnd) = E_Protected_Subtype
8356 or else Ekind (Opnd) = E_Task_Subtype
8358 Opnd := Etype (Opnd);
8361 if not Interface_Present_In_Ancestor
8365 if Is_Class_Wide_Type (Opnd) then
8367 -- The static analysis is not enough to know if the
8368 -- interface is implemented or not. Hence we must pass
8369 -- the work to the expander to generate code to evaluate
8370 -- the conversion at run-time.
8372 Expand_Interface_Conversion (N, Is_Static => False);
8375 Error_Msg_Name_1 := Chars (Etype (Target));
8376 Error_Msg_Name_2 := Chars (Opnd);
8378 ("wrong interface conversion (% is not a progenitor " &
8383 Expand_Interface_Conversion (N);
8388 end Resolve_Type_Conversion;
8390 ----------------------
8391 -- Resolve_Unary_Op --
8392 ----------------------
8394 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8395 B_Typ : constant Entity_Id := Base_Type (Typ);
8396 R : constant Node_Id := Right_Opnd (N);
8402 -- Deal with intrinsic unary operators
8404 if Comes_From_Source (N)
8405 and then Ekind (Entity (N)) = E_Function
8406 and then Is_Imported (Entity (N))
8407 and then Is_Intrinsic_Subprogram (Entity (N))
8409 Resolve_Intrinsic_Unary_Operator (N, Typ);
8413 -- Deal with universal cases
8415 if Etype (R) = Universal_Integer
8417 Etype (R) = Universal_Real
8419 Check_For_Visible_Operator (N, B_Typ);
8422 Set_Etype (N, B_Typ);
8425 -- Generate warning for expressions like abs (x mod 2)
8427 if Warn_On_Redundant_Constructs
8428 and then Nkind (N) = N_Op_Abs
8430 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8432 if OK and then Hi >= Lo and then Lo >= 0 then
8434 ("?abs applied to known non-negative value has no effect", N);
8438 -- Deal with reference generation
8440 Check_Unset_Reference (R);
8441 Generate_Operator_Reference (N, B_Typ);
8444 -- Set overflow checking bit. Much cleverer code needed here eventually
8445 -- and perhaps the Resolve routines should be separated for the various
8446 -- arithmetic operations, since they will need different processing ???
8448 if Nkind (N) in N_Op then
8449 if not Overflow_Checks_Suppressed (Etype (N)) then
8450 Enable_Overflow_Check (N);
8454 -- Generate warning for expressions like -5 mod 3 for integers. No need
8455 -- to worry in the floating-point case, since parens do not affect the
8456 -- result so there is no point in giving in a warning.
8459 Norig : constant Node_Id := Original_Node (N);
8468 if Warn_On_Questionable_Missing_Parens
8469 and then Comes_From_Source (Norig)
8470 and then Is_Integer_Type (Typ)
8471 and then Nkind (Norig) = N_Op_Minus
8473 Rorig := Original_Node (Right_Opnd (Norig));
8475 -- We are looking for cases where the right operand is not
8476 -- parenthesized, and is a binary operator, multiply, divide, or
8477 -- mod. These are the cases where the grouping can affect results.
8479 if Paren_Count (Rorig) = 0
8480 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8482 -- For mod, we always give the warning, since the value is
8483 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8484 -- -(5 mod 315)). But for the other cases, the only concern is
8485 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8486 -- overflows, but (-2) * 64 does not). So we try to give the
8487 -- message only when overflow is possible.
8489 if Nkind (Rorig) /= N_Op_Mod
8490 and then Compile_Time_Known_Value (R)
8492 Val := Expr_Value (R);
8494 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8495 HB := Expr_Value (Type_High_Bound (Typ));
8497 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8500 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8501 LB := Expr_Value (Type_Low_Bound (Typ));
8503 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8506 -- Note that the test below is deliberately excluding the
8507 -- largest negative number, since that is a potentially
8508 -- troublesome case (e.g. -2 * x, where the result is the
8509 -- largest negative integer has an overflow with 2 * x).
8511 if Val > LB and then Val <= HB then
8516 -- For the multiplication case, the only case we have to worry
8517 -- about is when (-a)*b is exactly the largest negative number
8518 -- so that -(a*b) can cause overflow. This can only happen if
8519 -- a is a power of 2, and more generally if any operand is a
8520 -- constant that is not a power of 2, then the parentheses
8521 -- cannot affect whether overflow occurs. We only bother to
8522 -- test the left most operand
8524 -- Loop looking at left operands for one that has known value
8527 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8528 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8529 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8531 -- Operand value of 0 or 1 skips warning
8536 -- Otherwise check power of 2, if power of 2, warn, if
8537 -- anything else, skip warning.
8540 while Lval /= 2 loop
8541 if Lval mod 2 = 1 then
8552 -- Keep looking at left operands
8554 Opnd := Left_Opnd (Opnd);
8557 -- For rem or "/" we can only have a problematic situation
8558 -- if the divisor has a value of minus one or one. Otherwise
8559 -- overflow is impossible (divisor > 1) or we have a case of
8560 -- division by zero in any case.
8562 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8563 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8564 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8569 -- If we fall through warning should be issued
8572 ("?unary minus expression should be parenthesized here!", N);
8576 end Resolve_Unary_Op;
8578 ----------------------------------
8579 -- Resolve_Unchecked_Expression --
8580 ----------------------------------
8582 procedure Resolve_Unchecked_Expression
8587 Resolve (Expression (N), Typ, Suppress => All_Checks);
8589 end Resolve_Unchecked_Expression;
8591 ---------------------------------------
8592 -- Resolve_Unchecked_Type_Conversion --
8593 ---------------------------------------
8595 procedure Resolve_Unchecked_Type_Conversion
8599 pragma Warnings (Off, Typ);
8601 Operand : constant Node_Id := Expression (N);
8602 Opnd_Type : constant Entity_Id := Etype (Operand);
8605 -- Resolve operand using its own type
8607 Resolve (Operand, Opnd_Type);
8608 Eval_Unchecked_Conversion (N);
8610 end Resolve_Unchecked_Type_Conversion;
8612 ------------------------------
8613 -- Rewrite_Operator_As_Call --
8614 ------------------------------
8616 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8617 Loc : constant Source_Ptr := Sloc (N);
8618 Actuals : constant List_Id := New_List;
8622 if Nkind (N) in N_Binary_Op then
8623 Append (Left_Opnd (N), Actuals);
8626 Append (Right_Opnd (N), Actuals);
8629 Make_Function_Call (Sloc => Loc,
8630 Name => New_Occurrence_Of (Nam, Loc),
8631 Parameter_Associations => Actuals);
8633 Preserve_Comes_From_Source (New_N, N);
8634 Preserve_Comes_From_Source (Name (New_N), N);
8636 Set_Etype (N, Etype (Nam));
8637 end Rewrite_Operator_As_Call;
8639 ------------------------------
8640 -- Rewrite_Renamed_Operator --
8641 ------------------------------
8643 procedure Rewrite_Renamed_Operator
8648 Nam : constant Name_Id := Chars (Op);
8649 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8653 -- Rewrite the operator node using the real operator, not its renaming.
8654 -- Exclude user-defined intrinsic operations of the same name, which are
8655 -- treated separately and rewritten as calls.
8657 if Ekind (Op) /= E_Function
8658 or else Chars (N) /= Nam
8660 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8661 Set_Chars (Op_Node, Nam);
8662 Set_Etype (Op_Node, Etype (N));
8663 Set_Entity (Op_Node, Op);
8664 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8666 -- Indicate that both the original entity and its renaming are
8667 -- referenced at this point.
8669 Generate_Reference (Entity (N), N);
8670 Generate_Reference (Op, N);
8673 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8676 Rewrite (N, Op_Node);
8678 -- If the context type is private, add the appropriate conversions
8679 -- so that the operator is applied to the full view. This is done
8680 -- in the routines that resolve intrinsic operators,
8682 if Is_Intrinsic_Subprogram (Op)
8683 and then Is_Private_Type (Typ)
8686 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8687 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8688 Resolve_Intrinsic_Operator (N, Typ);
8690 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8691 Resolve_Intrinsic_Unary_Operator (N, Typ);
8698 elsif Ekind (Op) = E_Function
8699 and then Is_Intrinsic_Subprogram (Op)
8701 -- Operator renames a user-defined operator of the same name. Use
8702 -- the original operator in the node, which is the one that Gigi
8706 Set_Is_Overloaded (N, False);
8708 end Rewrite_Renamed_Operator;
8710 -----------------------
8711 -- Set_Slice_Subtype --
8712 -----------------------
8714 -- Build an implicit subtype declaration to represent the type delivered
8715 -- by the slice. This is an abbreviated version of an array subtype. We
8716 -- define an index subtype for the slice, using either the subtype name
8717 -- or the discrete range of the slice. To be consistent with index usage
8718 -- elsewhere, we create a list header to hold the single index. This list
8719 -- is not otherwise attached to the syntax tree.
8721 procedure Set_Slice_Subtype (N : Node_Id) is
8722 Loc : constant Source_Ptr := Sloc (N);
8723 Index_List : constant List_Id := New_List;
8725 Index_Subtype : Entity_Id;
8726 Index_Type : Entity_Id;
8727 Slice_Subtype : Entity_Id;
8728 Drange : constant Node_Id := Discrete_Range (N);
8731 if Is_Entity_Name (Drange) then
8732 Index_Subtype := Entity (Drange);
8735 -- We force the evaluation of a range. This is definitely needed in
8736 -- the renamed case, and seems safer to do unconditionally. Note in
8737 -- any case that since we will create and insert an Itype referring
8738 -- to this range, we must make sure any side effect removal actions
8739 -- are inserted before the Itype definition.
8741 if Nkind (Drange) = N_Range then
8742 Force_Evaluation (Low_Bound (Drange));
8743 Force_Evaluation (High_Bound (Drange));
8746 Index_Type := Base_Type (Etype (Drange));
8748 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8750 Set_Scalar_Range (Index_Subtype, Drange);
8751 Set_Etype (Index_Subtype, Index_Type);
8752 Set_Size_Info (Index_Subtype, Index_Type);
8753 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8756 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8758 Index := New_Occurrence_Of (Index_Subtype, Loc);
8759 Set_Etype (Index, Index_Subtype);
8760 Append (Index, Index_List);
8762 Set_First_Index (Slice_Subtype, Index);
8763 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8764 Set_Is_Constrained (Slice_Subtype, True);
8766 Check_Compile_Time_Size (Slice_Subtype);
8768 -- The Etype of the existing Slice node is reset to this slice subtype.
8769 -- Its bounds are obtained from its first index.
8771 Set_Etype (N, Slice_Subtype);
8773 -- In the packed case, this must be immediately frozen
8775 -- Couldn't we always freeze here??? and if we did, then the above
8776 -- call to Check_Compile_Time_Size could be eliminated, which would
8777 -- be nice, because then that routine could be made private to Freeze.
8779 -- Why the test for In_Spec_Expression here ???
8781 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8782 Freeze_Itype (Slice_Subtype, N);
8785 end Set_Slice_Subtype;
8787 --------------------------------
8788 -- Set_String_Literal_Subtype --
8789 --------------------------------
8791 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8792 Loc : constant Source_Ptr := Sloc (N);
8793 Low_Bound : constant Node_Id :=
8794 Type_Low_Bound (Etype (First_Index (Typ)));
8795 Subtype_Id : Entity_Id;
8798 if Nkind (N) /= N_String_Literal then
8802 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8803 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8804 (String_Length (Strval (N))));
8805 Set_Etype (Subtype_Id, Base_Type (Typ));
8806 Set_Is_Constrained (Subtype_Id);
8807 Set_Etype (N, Subtype_Id);
8809 if Is_OK_Static_Expression (Low_Bound) then
8811 -- The low bound is set from the low bound of the corresponding
8812 -- index type. Note that we do not store the high bound in the
8813 -- string literal subtype, but it can be deduced if necessary
8814 -- from the length and the low bound.
8816 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8819 Set_String_Literal_Low_Bound
8820 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8821 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8823 -- Build bona fide subtype for the string, and wrap it in an
8824 -- unchecked conversion, because the backend expects the
8825 -- String_Literal_Subtype to have a static lower bound.
8828 Index_List : constant List_Id := New_List;
8829 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8830 High_Bound : constant Node_Id :=
8832 Left_Opnd => New_Copy_Tree (Low_Bound),
8834 Make_Integer_Literal (Loc,
8835 String_Length (Strval (N)) - 1));
8836 Array_Subtype : Entity_Id;
8837 Index_Subtype : Entity_Id;
8843 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8844 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8845 Set_Scalar_Range (Index_Subtype, Drange);
8846 Set_Parent (Drange, N);
8847 Analyze_And_Resolve (Drange, Index_Type);
8849 -- In the context, the Index_Type may already have a constraint,
8850 -- so use common base type on string subtype. The base type may
8851 -- be used when generating attributes of the string, for example
8852 -- in the context of a slice assignment.
8854 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8855 Set_Size_Info (Index_Subtype, Index_Type);
8856 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8858 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8860 Index := New_Occurrence_Of (Index_Subtype, Loc);
8861 Set_Etype (Index, Index_Subtype);
8862 Append (Index, Index_List);
8864 Set_First_Index (Array_Subtype, Index);
8865 Set_Etype (Array_Subtype, Base_Type (Typ));
8866 Set_Is_Constrained (Array_Subtype, True);
8869 Make_Unchecked_Type_Conversion (Loc,
8870 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8871 Expression => Relocate_Node (N)));
8872 Set_Etype (N, Array_Subtype);
8875 end Set_String_Literal_Subtype;
8877 ------------------------------
8878 -- Simplify_Type_Conversion --
8879 ------------------------------
8881 procedure Simplify_Type_Conversion (N : Node_Id) is
8883 if Nkind (N) = N_Type_Conversion then
8885 Operand : constant Node_Id := Expression (N);
8886 Target_Typ : constant Entity_Id := Etype (N);
8887 Opnd_Typ : constant Entity_Id := Etype (Operand);
8890 if Is_Floating_Point_Type (Opnd_Typ)
8892 (Is_Integer_Type (Target_Typ)
8893 or else (Is_Fixed_Point_Type (Target_Typ)
8894 and then Conversion_OK (N)))
8895 and then Nkind (Operand) = N_Attribute_Reference
8896 and then Attribute_Name (Operand) = Name_Truncation
8898 -- Special processing required if the conversion is the expression
8899 -- of a Truncation attribute reference. In this case we replace:
8901 -- ityp (ftyp'Truncation (x))
8907 -- with the Float_Truncate flag set, which is more efficient
8911 Relocate_Node (First (Expressions (Operand))));
8912 Set_Float_Truncate (N, True);
8916 end Simplify_Type_Conversion;
8918 -----------------------------
8919 -- Unique_Fixed_Point_Type --
8920 -----------------------------
8922 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8923 T1 : Entity_Id := Empty;
8928 procedure Fixed_Point_Error;
8929 -- Give error messages for true ambiguity. Messages are posted on node
8930 -- N, and entities T1, T2 are the possible interpretations.
8932 -----------------------
8933 -- Fixed_Point_Error --
8934 -----------------------
8936 procedure Fixed_Point_Error is
8938 Error_Msg_N ("ambiguous universal_fixed_expression", N);
8939 Error_Msg_NE ("\\possible interpretation as}", N, T1);
8940 Error_Msg_NE ("\\possible interpretation as}", N, T2);
8941 end Fixed_Point_Error;
8943 -- Start of processing for Unique_Fixed_Point_Type
8946 -- The operations on Duration are visible, so Duration is always a
8947 -- possible interpretation.
8949 T1 := Standard_Duration;
8951 -- Look for fixed-point types in enclosing scopes
8953 Scop := Current_Scope;
8954 while Scop /= Standard_Standard loop
8955 T2 := First_Entity (Scop);
8956 while Present (T2) loop
8957 if Is_Fixed_Point_Type (T2)
8958 and then Current_Entity (T2) = T2
8959 and then Scope (Base_Type (T2)) = Scop
8961 if Present (T1) then
8972 Scop := Scope (Scop);
8975 -- Look for visible fixed type declarations in the context
8977 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
8978 while Present (Item) loop
8979 if Nkind (Item) = N_With_Clause then
8980 Scop := Entity (Name (Item));
8981 T2 := First_Entity (Scop);
8982 while Present (T2) loop
8983 if Is_Fixed_Point_Type (T2)
8984 and then Scope (Base_Type (T2)) = Scop
8985 and then (Is_Potentially_Use_Visible (T2)
8986 or else In_Use (T2))
8988 if Present (T1) then
9003 if Nkind (N) = N_Real_Literal then
9004 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9006 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9010 end Unique_Fixed_Point_Type;
9012 ----------------------
9013 -- Valid_Conversion --
9014 ----------------------
9016 function Valid_Conversion
9019 Operand : Node_Id) return Boolean
9021 Target_Type : constant Entity_Id := Base_Type (Target);
9022 Opnd_Type : Entity_Id := Etype (Operand);
9024 function Conversion_Check
9026 Msg : String) return Boolean;
9027 -- Little routine to post Msg if Valid is False, returns Valid value
9029 function Valid_Tagged_Conversion
9030 (Target_Type : Entity_Id;
9031 Opnd_Type : Entity_Id) return Boolean;
9032 -- Specifically test for validity of tagged conversions
9034 function Valid_Array_Conversion return Boolean;
9035 -- Check index and component conformance, and accessibility levels
9036 -- if the component types are anonymous access types (Ada 2005)
9038 ----------------------
9039 -- Conversion_Check --
9040 ----------------------
9042 function Conversion_Check
9044 Msg : String) return Boolean
9048 Error_Msg_N (Msg, Operand);
9052 end Conversion_Check;
9054 ----------------------------
9055 -- Valid_Array_Conversion --
9056 ----------------------------
9058 function Valid_Array_Conversion return Boolean
9060 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9061 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9063 Opnd_Index : Node_Id;
9064 Opnd_Index_Type : Entity_Id;
9066 Target_Comp_Type : constant Entity_Id :=
9067 Component_Type (Target_Type);
9068 Target_Comp_Base : constant Entity_Id :=
9069 Base_Type (Target_Comp_Type);
9071 Target_Index : Node_Id;
9072 Target_Index_Type : Entity_Id;
9075 -- Error if wrong number of dimensions
9078 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9081 ("incompatible number of dimensions for conversion", Operand);
9084 -- Number of dimensions matches
9087 -- Loop through indexes of the two arrays
9089 Target_Index := First_Index (Target_Type);
9090 Opnd_Index := First_Index (Opnd_Type);
9091 while Present (Target_Index) and then Present (Opnd_Index) loop
9092 Target_Index_Type := Etype (Target_Index);
9093 Opnd_Index_Type := Etype (Opnd_Index);
9095 -- Error if index types are incompatible
9097 if not (Is_Integer_Type (Target_Index_Type)
9098 and then Is_Integer_Type (Opnd_Index_Type))
9099 and then (Root_Type (Target_Index_Type)
9100 /= Root_Type (Opnd_Index_Type))
9103 ("incompatible index types for array conversion",
9108 Next_Index (Target_Index);
9109 Next_Index (Opnd_Index);
9112 -- If component types have same base type, all set
9114 if Target_Comp_Base = Opnd_Comp_Base then
9117 -- Here if base types of components are not the same. The only
9118 -- time this is allowed is if we have anonymous access types.
9120 -- The conversion of arrays of anonymous access types can lead
9121 -- to dangling pointers. AI-392 formalizes the accessibility
9122 -- checks that must be applied to such conversions to prevent
9123 -- out-of-scope references.
9126 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9128 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9129 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9131 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9133 if Type_Access_Level (Target_Type) <
9134 Type_Access_Level (Opnd_Type)
9136 if In_Instance_Body then
9137 Error_Msg_N ("?source array type " &
9138 "has deeper accessibility level than target", Operand);
9139 Error_Msg_N ("\?Program_Error will be raised at run time",
9142 Make_Raise_Program_Error (Sloc (N),
9143 Reason => PE_Accessibility_Check_Failed));
9144 Set_Etype (N, Target_Type);
9147 -- Conversion not allowed because of accessibility levels
9150 Error_Msg_N ("source array type " &
9151 "has deeper accessibility level than target", Operand);
9158 -- All other cases where component base types do not match
9162 ("incompatible component types for array conversion",
9167 -- Check that component subtypes statically match. For numeric
9168 -- types this means that both must be either constrained or
9169 -- unconstrained. For enumeration types the bounds must match.
9170 -- All of this is checked in Subtypes_Statically_Match.
9172 if not Subtypes_Statically_Match
9173 (Target_Comp_Type, Opnd_Comp_Type)
9176 ("component subtypes must statically match", Operand);
9182 end Valid_Array_Conversion;
9184 -----------------------------
9185 -- Valid_Tagged_Conversion --
9186 -----------------------------
9188 function Valid_Tagged_Conversion
9189 (Target_Type : Entity_Id;
9190 Opnd_Type : Entity_Id) return Boolean
9193 -- Upward conversions are allowed (RM 4.6(22))
9195 if Covers (Target_Type, Opnd_Type)
9196 or else Is_Ancestor (Target_Type, Opnd_Type)
9200 -- Downward conversion are allowed if the operand is class-wide
9203 elsif Is_Class_Wide_Type (Opnd_Type)
9204 and then Covers (Opnd_Type, Target_Type)
9208 elsif Covers (Opnd_Type, Target_Type)
9209 or else Is_Ancestor (Opnd_Type, Target_Type)
9212 Conversion_Check (False,
9213 "downward conversion of tagged objects not allowed");
9215 -- Ada 2005 (AI-251): The conversion to/from interface types is
9218 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9221 -- If the operand is a class-wide type obtained through a limited_
9222 -- with clause, and the context includes the non-limited view, use
9223 -- it to determine whether the conversion is legal.
9225 elsif Is_Class_Wide_Type (Opnd_Type)
9226 and then From_With_Type (Opnd_Type)
9227 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9228 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9232 elsif Is_Access_Type (Opnd_Type)
9233 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9239 ("invalid tagged conversion, not compatible with}",
9240 N, First_Subtype (Opnd_Type));
9243 end Valid_Tagged_Conversion;
9245 -- Start of processing for Valid_Conversion
9248 Check_Parameterless_Call (Operand);
9250 if Is_Overloaded (Operand) then
9259 -- Remove procedure calls, which syntactically cannot appear in
9260 -- this context, but which cannot be removed by type checking,
9261 -- because the context does not impose a type.
9263 -- When compiling for VMS, spurious ambiguities can be produced
9264 -- when arithmetic operations have a literal operand and return
9265 -- System.Address or a descendant of it. These ambiguities are
9266 -- otherwise resolved by the context, but for conversions there
9267 -- is no context type and the removal of the spurious operations
9268 -- must be done explicitly here.
9270 -- The node may be labelled overloaded, but still contain only
9271 -- one interpretation because others were discarded in previous
9272 -- filters. If this is the case, retain the single interpretation
9275 Get_First_Interp (Operand, I, It);
9276 Opnd_Type := It.Typ;
9277 Get_Next_Interp (I, It);
9280 and then Opnd_Type /= Standard_Void_Type
9282 -- More than one candidate interpretation is available
9284 Get_First_Interp (Operand, I, It);
9285 while Present (It.Typ) loop
9286 if It.Typ = Standard_Void_Type then
9290 if Present (System_Aux_Id)
9291 and then Is_Descendent_Of_Address (It.Typ)
9296 Get_Next_Interp (I, It);
9300 Get_First_Interp (Operand, I, It);
9305 Error_Msg_N ("illegal operand in conversion", Operand);
9309 Get_Next_Interp (I, It);
9311 if Present (It.Typ) then
9313 It1 := Disambiguate (Operand, I1, I, Any_Type);
9315 if It1 = No_Interp then
9316 Error_Msg_N ("ambiguous operand in conversion", Operand);
9318 Error_Msg_Sloc := Sloc (It.Nam);
9319 Error_Msg_N -- CODEFIX
9320 ("\\possible interpretation#!", Operand);
9322 Error_Msg_Sloc := Sloc (N1);
9323 Error_Msg_N -- CODEFIX
9324 ("\\possible interpretation#!", Operand);
9330 Set_Etype (Operand, It1.Typ);
9331 Opnd_Type := It1.Typ;
9337 if Is_Numeric_Type (Target_Type) then
9339 -- A universal fixed expression can be converted to any numeric type
9341 if Opnd_Type = Universal_Fixed then
9344 -- Also no need to check when in an instance or inlined body, because
9345 -- the legality has been established when the template was analyzed.
9346 -- Furthermore, numeric conversions may occur where only a private
9347 -- view of the operand type is visible at the instantiation point.
9348 -- This results in a spurious error if we check that the operand type
9349 -- is a numeric type.
9351 -- Note: in a previous version of this unit, the following tests were
9352 -- applied only for generated code (Comes_From_Source set to False),
9353 -- but in fact the test is required for source code as well, since
9354 -- this situation can arise in source code.
9356 elsif In_Instance or else In_Inlined_Body then
9359 -- Otherwise we need the conversion check
9362 return Conversion_Check
9363 (Is_Numeric_Type (Opnd_Type),
9364 "illegal operand for numeric conversion");
9369 elsif Is_Array_Type (Target_Type) then
9370 if not Is_Array_Type (Opnd_Type)
9371 or else Opnd_Type = Any_Composite
9372 or else Opnd_Type = Any_String
9375 ("illegal operand for array conversion", Operand);
9378 return Valid_Array_Conversion;
9381 -- Ada 2005 (AI-251): Anonymous access types where target references an
9384 elsif (Ekind (Target_Type) = E_General_Access_Type
9386 Ekind (Target_Type) = E_Anonymous_Access_Type)
9387 and then Is_Interface (Directly_Designated_Type (Target_Type))
9389 -- Check the static accessibility rule of 4.6(17). Note that the
9390 -- check is not enforced when within an instance body, since the
9391 -- RM requires such cases to be caught at run time.
9393 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9394 if Type_Access_Level (Opnd_Type) >
9395 Type_Access_Level (Target_Type)
9397 -- In an instance, this is a run-time check, but one we know
9398 -- will fail, so generate an appropriate warning. The raise
9399 -- will be generated by Expand_N_Type_Conversion.
9401 if In_Instance_Body then
9403 ("?cannot convert local pointer to non-local access type",
9406 ("\?Program_Error will be raised at run time", Operand);
9409 ("cannot convert local pointer to non-local access type",
9414 -- Special accessibility checks are needed in the case of access
9415 -- discriminants declared for a limited type.
9417 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9418 and then not Is_Local_Anonymous_Access (Opnd_Type)
9420 -- When the operand is a selected access discriminant the check
9421 -- needs to be made against the level of the object denoted by
9422 -- the prefix of the selected name (Object_Access_Level handles
9423 -- checking the prefix of the operand for this case).
9425 if Nkind (Operand) = N_Selected_Component
9426 and then Object_Access_Level (Operand) >
9427 Type_Access_Level (Target_Type)
9429 -- In an instance, this is a run-time check, but one we know
9430 -- will fail, so generate an appropriate warning. The raise
9431 -- will be generated by Expand_N_Type_Conversion.
9433 if In_Instance_Body then
9435 ("?cannot convert access discriminant to non-local" &
9436 " access type", Operand);
9438 ("\?Program_Error will be raised at run time", Operand);
9441 ("cannot convert access discriminant to non-local" &
9442 " access type", Operand);
9447 -- The case of a reference to an access discriminant from
9448 -- within a limited type declaration (which will appear as
9449 -- a discriminal) is always illegal because the level of the
9450 -- discriminant is considered to be deeper than any (nameable)
9453 if Is_Entity_Name (Operand)
9454 and then not Is_Local_Anonymous_Access (Opnd_Type)
9455 and then (Ekind (Entity (Operand)) = E_In_Parameter
9456 or else Ekind (Entity (Operand)) = E_Constant)
9457 and then Present (Discriminal_Link (Entity (Operand)))
9460 ("discriminant has deeper accessibility level than target",
9469 -- General and anonymous access types
9471 elsif (Ekind (Target_Type) = E_General_Access_Type
9472 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9475 (Is_Access_Type (Opnd_Type)
9476 and then Ekind (Opnd_Type) /=
9477 E_Access_Subprogram_Type
9478 and then Ekind (Opnd_Type) /=
9479 E_Access_Protected_Subprogram_Type,
9480 "must be an access-to-object type")
9482 if Is_Access_Constant (Opnd_Type)
9483 and then not Is_Access_Constant (Target_Type)
9486 ("access-to-constant operand type not allowed", Operand);
9490 -- Check the static accessibility rule of 4.6(17). Note that the
9491 -- check is not enforced when within an instance body, since the RM
9492 -- requires such cases to be caught at run time.
9494 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9495 or else Is_Local_Anonymous_Access (Target_Type)
9497 if Type_Access_Level (Opnd_Type)
9498 > Type_Access_Level (Target_Type)
9500 -- In an instance, this is a run-time check, but one we know
9501 -- will fail, so generate an appropriate warning. The raise
9502 -- will be generated by Expand_N_Type_Conversion.
9504 if In_Instance_Body then
9506 ("?cannot convert local pointer to non-local access type",
9509 ("\?Program_Error will be raised at run time", Operand);
9512 -- Avoid generation of spurious error message
9514 if not Error_Posted (N) then
9516 ("cannot convert local pointer to non-local access type",
9523 -- Special accessibility checks are needed in the case of access
9524 -- discriminants declared for a limited type.
9526 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9527 and then not Is_Local_Anonymous_Access (Opnd_Type)
9530 -- When the operand is a selected access discriminant the check
9531 -- needs to be made against the level of the object denoted by
9532 -- the prefix of the selected name (Object_Access_Level handles
9533 -- checking the prefix of the operand for this case).
9535 if Nkind (Operand) = N_Selected_Component
9536 and then Object_Access_Level (Operand) >
9537 Type_Access_Level (Target_Type)
9539 -- In an instance, this is a run-time check, but one we know
9540 -- will fail, so generate an appropriate warning. The raise
9541 -- will be generated by Expand_N_Type_Conversion.
9543 if In_Instance_Body then
9545 ("?cannot convert access discriminant to non-local" &
9546 " access type", Operand);
9548 ("\?Program_Error will be raised at run time",
9553 ("cannot convert access discriminant to non-local" &
9554 " access type", Operand);
9559 -- The case of a reference to an access discriminant from
9560 -- within a limited type declaration (which will appear as
9561 -- a discriminal) is always illegal because the level of the
9562 -- discriminant is considered to be deeper than any (nameable)
9565 if Is_Entity_Name (Operand)
9566 and then (Ekind (Entity (Operand)) = E_In_Parameter
9567 or else Ekind (Entity (Operand)) = E_Constant)
9568 and then Present (Discriminal_Link (Entity (Operand)))
9571 ("discriminant has deeper accessibility level than target",
9578 -- Need some comments here, and a name for this block ???
9581 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9582 -- Helper function to handle limited views
9584 --------------------------
9585 -- Full_Designated_Type --
9586 --------------------------
9588 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9589 Desig : constant Entity_Id := Designated_Type (T);
9591 if From_With_Type (Desig)
9592 and then Is_Incomplete_Type (Desig)
9593 and then Present (Non_Limited_View (Desig))
9595 return Non_Limited_View (Desig);
9599 end Full_Designated_Type;
9601 -- Local Declarations
9603 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9604 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9606 Same_Base : constant Boolean :=
9607 Base_Type (Target) = Base_Type (Opnd);
9609 -- Start of processing for ???
9612 if Is_Tagged_Type (Target) then
9613 return Valid_Tagged_Conversion (Target, Opnd);
9616 if not Same_Base then
9618 ("target designated type not compatible with }",
9619 N, Base_Type (Opnd));
9622 -- Ada 2005 AI-384: legality rule is symmetric in both
9623 -- designated types. The conversion is legal (with possible
9624 -- constraint check) if either designated type is
9627 elsif Subtypes_Statically_Match (Target, Opnd)
9629 (Has_Discriminants (Target)
9631 (not Is_Constrained (Opnd)
9632 or else not Is_Constrained (Target)))
9634 -- Special case, if Value_Size has been used to make the
9635 -- sizes different, the conversion is not allowed even
9636 -- though the subtypes statically match.
9638 if Known_Static_RM_Size (Target)
9639 and then Known_Static_RM_Size (Opnd)
9640 and then RM_Size (Target) /= RM_Size (Opnd)
9643 ("target designated subtype not compatible with }",
9646 ("\because sizes of the two designated subtypes differ",
9650 -- Normal case where conversion is allowed
9658 ("target designated subtype not compatible with }",
9665 -- Access to subprogram types. If the operand is an access parameter,
9666 -- the type has a deeper accessibility that any master, and cannot
9667 -- be assigned. We must make an exception if the conversion is part
9668 -- of an assignment and the target is the return object of an extended
9669 -- return statement, because in that case the accessibility check
9670 -- takes place after the return.
9672 elsif Is_Access_Subprogram_Type (Target_Type)
9673 and then No (Corresponding_Remote_Type (Opnd_Type))
9675 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9676 and then Is_Entity_Name (Operand)
9677 and then Ekind (Entity (Operand)) = E_In_Parameter
9679 (Nkind (Parent (N)) /= N_Assignment_Statement
9680 or else not Is_Entity_Name (Name (Parent (N)))
9681 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9684 ("illegal attempt to store anonymous access to subprogram",
9687 ("\value has deeper accessibility than any master " &
9692 ("\use named access type for& instead of access parameter",
9693 Operand, Entity (Operand));
9696 -- Check that the designated types are subtype conformant
9698 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9699 Old_Id => Designated_Type (Opnd_Type),
9702 -- Check the static accessibility rule of 4.6(20)
9704 if Type_Access_Level (Opnd_Type) >
9705 Type_Access_Level (Target_Type)
9708 ("operand type has deeper accessibility level than target",
9711 -- Check that if the operand type is declared in a generic body,
9712 -- then the target type must be declared within that same body
9713 -- (enforces last sentence of 4.6(20)).
9715 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9717 O_Gen : constant Node_Id :=
9718 Enclosing_Generic_Body (Opnd_Type);
9723 T_Gen := Enclosing_Generic_Body (Target_Type);
9724 while Present (T_Gen) and then T_Gen /= O_Gen loop
9725 T_Gen := Enclosing_Generic_Body (T_Gen);
9728 if T_Gen /= O_Gen then
9730 ("target type must be declared in same generic body"
9731 & " as operand type", N);
9738 -- Remote subprogram access types
9740 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9741 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9743 -- It is valid to convert from one RAS type to another provided
9744 -- that their specification statically match.
9746 Check_Subtype_Conformant
9748 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9750 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9755 -- If both are tagged types, check legality of view conversions
9757 elsif Is_Tagged_Type (Target_Type)
9758 and then Is_Tagged_Type (Opnd_Type)
9760 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9762 -- Types derived from the same root type are convertible
9764 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9767 -- In an instance or an inlined body, there may be inconsistent
9768 -- views of the same type, or of types derived from a common root.
9770 elsif (In_Instance or In_Inlined_Body)
9772 Root_Type (Underlying_Type (Target_Type)) =
9773 Root_Type (Underlying_Type (Opnd_Type))
9777 -- Special check for common access type error case
9779 elsif Ekind (Target_Type) = E_Access_Type
9780 and then Is_Access_Type (Opnd_Type)
9782 Error_Msg_N ("target type must be general access type!", N);
9783 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9787 Error_Msg_NE ("invalid conversion, not compatible with }",
9791 end Valid_Conversion;