1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2006, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Debug_A; use Debug_A;
31 with Einfo; use Einfo;
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 Freeze; use Freeze;
40 with Itypes; use Itypes;
42 with Lib.Xref; use Lib.Xref;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
45 with Nlists; use Nlists;
47 with Output; use Output;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
52 with Sem_Aggr; use Sem_Aggr;
53 with Sem_Attr; use Sem_Attr;
54 with Sem_Cat; use Sem_Cat;
55 with Sem_Ch4; use Sem_Ch4;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch8; use Sem_Ch8;
58 with Sem_Disp; use Sem_Disp;
59 with Sem_Dist; use Sem_Dist;
60 with Sem_Elab; use Sem_Elab;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Intr; use Sem_Intr;
63 with Sem_Util; use Sem_Util;
64 with Sem_Type; use Sem_Type;
65 with Sem_Warn; use Sem_Warn;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Stand; use Stand;
69 with Stringt; use Stringt;
70 with Tbuild; use Tbuild;
71 with Uintp; use Uintp;
72 with Urealp; use Urealp;
74 package body Sem_Res is
76 -----------------------
77 -- Local Subprograms --
78 -----------------------
80 -- Second pass (top-down) type checking and overload resolution procedures
81 -- Typ is the type required by context. These procedures propagate the
82 -- type information recursively to the descendants of N. If the node
83 -- is not overloaded, its Etype is established in the first pass. If
84 -- overloaded, the Resolve routines set the correct type. For arith.
85 -- operators, the Etype is the base type of the context.
87 -- Note that Resolve_Attribute is separated off in Sem_Attr
89 procedure Ambiguous_Character (C : Node_Id);
90 -- Give list of candidate interpretations when a character literal cannot
93 procedure Check_Discriminant_Use (N : Node_Id);
94 -- Enforce the restrictions on the use of discriminants when constraining
95 -- a component of a discriminated type (record or concurrent type).
97 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
98 -- Given a node for an operator associated with type T, check that
99 -- the operator is visible. Operators all of whose operands are
100 -- universal must be checked for visibility during resolution
101 -- because their type is not determinable based on their operands.
103 procedure Check_Fully_Declared_Prefix
106 -- Check that the type of the prefix of a dereference is not incomplete
108 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
109 -- Given a call node, N, which is known to occur immediately within the
110 -- subprogram being called, determines whether it is a detectable case of
111 -- an infinite recursion, and if so, outputs appropriate messages. Returns
112 -- True if an infinite recursion is detected, and False otherwise.
114 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
115 -- If the type of the object being initialized uses the secondary stack
116 -- directly or indirectly, create a transient scope for the call to the
117 -- init proc. This is because we do not create transient scopes for the
118 -- initialization of individual components within the init proc itself.
119 -- Could be optimized away perhaps?
121 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
122 -- Utility to check whether the name in the call is a predefined
123 -- operator, in which case the call is made into an operator node.
124 -- An instance of an intrinsic conversion operation may be given
125 -- an operator name, but is not treated like an operator.
127 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
128 -- If a default expression in entry call N depends on the discriminants
129 -- of the task, it must be replaced with a reference to the discriminant
130 -- of the task being called.
132 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
133 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
134 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
135 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
136 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
137 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
138 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
139 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
140 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
141 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
142 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
143 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
144 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
145 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
146 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
147 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
148 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
149 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
150 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
151 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
152 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
153 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
154 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
155 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
156 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
157 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
158 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
159 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
165 function Operator_Kind
167 Is_Binary : Boolean) return Node_Kind;
168 -- Utility to map the name of an operator into the corresponding Node. Used
169 -- by other node rewriting procedures.
171 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
172 -- Resolve actuals of call, and add default expressions for missing ones.
173 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
174 -- called subprogram.
176 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
177 -- Called from Resolve_Call, when the prefix denotes an entry or element
178 -- of entry family. Actuals are resolved as for subprograms, and the node
179 -- is rebuilt as an entry call. Also called for protected operations. Typ
180 -- is the context type, which is used when the operation is a protected
181 -- function with no arguments, and the return value is indexed.
183 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
184 -- A call to a user-defined intrinsic operator is rewritten as a call
185 -- to the corresponding predefined operator, with suitable conversions.
187 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
188 -- Ditto, for unary operators (only arithmetic ones)
190 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
191 -- If an operator node resolves to a call to a user-defined operator,
192 -- rewrite the node as a function call.
194 procedure Make_Call_Into_Operator
198 -- Inverse transformation: if an operator is given in functional notation,
199 -- then after resolving the node, transform into an operator node, so
200 -- that operands are resolved properly. Recall that predefined operators
201 -- do not have a full signature and special resolution rules apply.
203 procedure Rewrite_Renamed_Operator
207 -- An operator can rename another, e.g. in an instantiation. In that
208 -- case, the proper operator node must be constructed and resolved.
210 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
211 -- The String_Literal_Subtype is built for all strings that are not
212 -- operands of a static concatenation operation. If the argument is
213 -- not a N_String_Literal node, then the call has no effect.
215 procedure Set_Slice_Subtype (N : Node_Id);
216 -- Build subtype of array type, with the range specified by the slice
218 procedure Simplify_Type_Conversion (N : Node_Id);
219 -- Called after N has been resolved and evaluated, but before range checks
220 -- have been applied. Currently simplifies a combination of floating-point
221 -- to integer conversion and Truncation attribute.
223 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
224 -- A universal_fixed expression in an universal context is unambiguous
225 -- if there is only one applicable fixed point type. Determining whether
226 -- there is only one requires a search over all visible entities, and
227 -- happens only in very pathological cases (see 6115-006).
229 function Valid_Conversion
232 Operand : Node_Id) return Boolean;
233 -- Verify legality rules given in 4.6 (8-23). Target is the target
234 -- type of the conversion, which may be an implicit conversion of
235 -- an actual parameter to an anonymous access type (in which case
236 -- N denotes the actual parameter and N = Operand).
238 -------------------------
239 -- Ambiguous_Character --
240 -------------------------
242 procedure Ambiguous_Character (C : Node_Id) is
246 if Nkind (C) = N_Character_Literal then
247 Error_Msg_N ("ambiguous character literal", C);
249 ("\\possible interpretations: Character, Wide_Character!", C);
251 E := Current_Entity (C);
252 while Present (E) loop
253 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
257 end Ambiguous_Character;
259 -------------------------
260 -- Analyze_And_Resolve --
261 -------------------------
263 procedure Analyze_And_Resolve (N : Node_Id) is
267 end Analyze_And_Resolve;
269 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
273 end Analyze_And_Resolve;
275 -- Version withs check(s) suppressed
277 procedure Analyze_And_Resolve
282 Scop : constant Entity_Id := Current_Scope;
285 if Suppress = All_Checks then
287 Svg : constant Suppress_Array := Scope_Suppress;
289 Scope_Suppress := (others => True);
290 Analyze_And_Resolve (N, Typ);
291 Scope_Suppress := Svg;
296 Svg : constant Boolean := Scope_Suppress (Suppress);
299 Scope_Suppress (Suppress) := True;
300 Analyze_And_Resolve (N, Typ);
301 Scope_Suppress (Suppress) := Svg;
305 if Current_Scope /= Scop
306 and then Scope_Is_Transient
308 -- This can only happen if a transient scope was created
309 -- for an inner expression, which will be removed upon
310 -- completion of the analysis of an enclosing construct.
311 -- The transient scope must have the suppress status of
312 -- the enclosing environment, not of this Analyze call.
314 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
317 end Analyze_And_Resolve;
319 procedure Analyze_And_Resolve
323 Scop : constant Entity_Id := Current_Scope;
326 if Suppress = All_Checks then
328 Svg : constant Suppress_Array := Scope_Suppress;
330 Scope_Suppress := (others => True);
331 Analyze_And_Resolve (N);
332 Scope_Suppress := Svg;
337 Svg : constant Boolean := Scope_Suppress (Suppress);
340 Scope_Suppress (Suppress) := True;
341 Analyze_And_Resolve (N);
342 Scope_Suppress (Suppress) := Svg;
346 if Current_Scope /= Scop
347 and then Scope_Is_Transient
349 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
352 end Analyze_And_Resolve;
354 ----------------------------
355 -- Check_Discriminant_Use --
356 ----------------------------
358 procedure Check_Discriminant_Use (N : Node_Id) is
359 PN : constant Node_Id := Parent (N);
360 Disc : constant Entity_Id := Entity (N);
365 -- Any use in a default expression is legal
367 if In_Default_Expression then
370 elsif Nkind (PN) = N_Range then
372 -- Discriminant cannot be used to constrain a scalar type
376 if Nkind (P) = N_Range_Constraint
377 and then Nkind (Parent (P)) = N_Subtype_Indication
378 and then Nkind (Parent (Parent (P))) = N_Component_Definition
380 Error_Msg_N ("discriminant cannot constrain scalar type", N);
382 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
384 -- The following check catches the unusual case where
385 -- a discriminant appears within an index constraint
386 -- that is part of a larger expression within a constraint
387 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
388 -- For now we only check case of record components, and
389 -- note that a similar check should also apply in the
390 -- case of discriminant constraints below. ???
392 -- Note that the check for N_Subtype_Declaration below is to
393 -- detect the valid use of discriminants in the constraints of a
394 -- subtype declaration when this subtype declaration appears
395 -- inside the scope of a record type (which is syntactically
396 -- illegal, but which may be created as part of derived type
397 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
400 if Ekind (Current_Scope) = E_Record_Type
401 and then Scope (Disc) = Current_Scope
403 (Nkind (Parent (P)) = N_Subtype_Indication
405 (Nkind (Parent (Parent (P))) = N_Component_Definition
407 Nkind (Parent (Parent (P))) = N_Subtype_Declaration)
408 and then Paren_Count (N) = 0)
411 ("discriminant must appear alone in component constraint", N);
415 -- Detect a common beginner error:
417 -- type R (D : Positive := 100) is record
418 -- Name : String (1 .. D);
421 -- The default value causes an object of type R to be
422 -- allocated with room for Positive'Last characters.
430 function Large_Storage_Type (T : Entity_Id) return Boolean;
431 -- Return True if type T has a large enough range that
432 -- any array whose index type covered the whole range of
433 -- the type would likely raise Storage_Error.
435 ------------------------
436 -- Large_Storage_Type --
437 ------------------------
439 function Large_Storage_Type (T : Entity_Id) return Boolean is
444 T = Standard_Positive
446 T = Standard_Natural;
447 end Large_Storage_Type;
450 -- Check that the Disc has a large range
452 if not Large_Storage_Type (Etype (Disc)) then
456 -- If the enclosing type is limited, we allocate only the
457 -- default value, not the maximum, and there is no need for
460 if Is_Limited_Type (Scope (Disc)) then
464 -- Check that it is the high bound
466 if N /= High_Bound (PN)
467 or else No (Discriminant_Default_Value (Disc))
472 -- Check the array allows a large range at this bound.
473 -- First find the array
477 if Nkind (SI) /= N_Subtype_Indication then
481 T := Entity (Subtype_Mark (SI));
483 if not Is_Array_Type (T) then
487 -- Next, find the dimension
489 TB := First_Index (T);
490 CB := First (Constraints (P));
492 and then Present (TB)
493 and then Present (CB)
504 -- Now, check the dimension has a large range
506 if not Large_Storage_Type (Etype (TB)) then
510 -- Warn about the danger
513 ("creation of & object may raise Storage_Error?",
522 -- Legal case is in index or discriminant constraint
524 elsif Nkind (PN) = N_Index_Or_Discriminant_Constraint
525 or else Nkind (PN) = N_Discriminant_Association
527 if Paren_Count (N) > 0 then
529 ("discriminant in constraint must appear alone", N);
531 elsif Nkind (N) = N_Expanded_Name
532 and then Comes_From_Source (N)
535 ("discriminant must appear alone as a direct name", N);
540 -- Otherwise, context is an expression. It should not be within
541 -- (i.e. a subexpression of) a constraint for a component.
546 while Nkind (P) /= N_Component_Declaration
547 and then Nkind (P) /= N_Subtype_Indication
548 and then Nkind (P) /= N_Entry_Declaration
555 -- If the discriminant is used in an expression that is a bound
556 -- of a scalar type, an Itype is created and the bounds are attached
557 -- to its range, not to the original subtype indication. Such use
558 -- is of course a double fault.
560 if (Nkind (P) = N_Subtype_Indication
562 (Nkind (Parent (P)) = N_Component_Definition
564 Nkind (Parent (P)) = N_Derived_Type_Definition)
565 and then D = Constraint (P))
567 -- The constraint itself may be given by a subtype indication,
568 -- rather than by a more common discrete range.
570 or else (Nkind (P) = N_Subtype_Indication
572 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
573 or else Nkind (P) = N_Entry_Declaration
574 or else Nkind (D) = N_Defining_Identifier
577 ("discriminant in constraint must appear alone", N);
580 end Check_Discriminant_Use;
582 --------------------------------
583 -- Check_For_Visible_Operator --
584 --------------------------------
586 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
588 if Is_Invisible_Operator (N, T) then
590 ("operator for} is not directly visible!", N, First_Subtype (T));
591 Error_Msg_N ("use clause would make operation legal!", N);
593 end Check_For_Visible_Operator;
595 ----------------------------------
596 -- Check_Fully_Declared_Prefix --
597 ----------------------------------
599 procedure Check_Fully_Declared_Prefix
604 -- Check that the designated type of the prefix of a dereference is
605 -- not an incomplete type. This cannot be done unconditionally, because
606 -- dereferences of private types are legal in default expressions. This
607 -- case is taken care of in Check_Fully_Declared, called below. There
608 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
610 -- This consideration also applies to similar checks for allocators,
611 -- qualified expressions, and type conversions.
613 -- An additional exception concerns other per-object expressions that
614 -- are not directly related to component declarations, in particular
615 -- representation pragmas for tasks. These will be per-object
616 -- expressions if they depend on discriminants or some global entity.
617 -- If the task has access discriminants, the designated type may be
618 -- incomplete at the point the expression is resolved. This resolution
619 -- takes place within the body of the initialization procedure, where
620 -- the discriminant is replaced by its discriminal.
622 if Is_Entity_Name (Pref)
623 and then Ekind (Entity (Pref)) = E_In_Parameter
627 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
628 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
629 -- Analyze_Object_Renaming, and Freeze_Entity.
631 elsif Ada_Version >= Ada_05
632 and then Is_Entity_Name (Pref)
633 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
635 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
639 Check_Fully_Declared (Typ, Parent (Pref));
641 end Check_Fully_Declared_Prefix;
643 ------------------------------
644 -- Check_Infinite_Recursion --
645 ------------------------------
647 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
651 function Same_Argument_List return Boolean;
652 -- Check whether list of actuals is identical to list of formals
653 -- of called function (which is also the enclosing scope).
655 ------------------------
656 -- Same_Argument_List --
657 ------------------------
659 function Same_Argument_List return Boolean is
665 if not Is_Entity_Name (Name (N)) then
668 Subp := Entity (Name (N));
671 F := First_Formal (Subp);
672 A := First_Actual (N);
673 while Present (F) and then Present (A) loop
674 if not Is_Entity_Name (A)
675 or else Entity (A) /= F
685 end Same_Argument_List;
687 -- Start of processing for Check_Infinite_Recursion
690 -- Loop moving up tree, quitting if something tells us we are
691 -- definitely not in an infinite recursion situation.
696 exit when Nkind (P) = N_Subprogram_Body;
698 if Nkind (P) = N_Or_Else or else
699 Nkind (P) = N_And_Then or else
700 Nkind (P) = N_If_Statement or else
701 Nkind (P) = N_Case_Statement
705 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
706 and then C /= First (Statements (P))
708 -- If the call is the expression of a return statement and
709 -- the actuals are identical to the formals, it's worth a
710 -- warning. However, we skip this if there is an immediately
711 -- preceding raise statement, since the call is never executed.
713 -- Furthermore, this corresponds to a common idiom:
715 -- function F (L : Thing) return Boolean is
717 -- raise Program_Error;
721 -- for generating a stub function
723 if Nkind (Parent (N)) = N_Return_Statement
724 and then Same_Argument_List
726 exit when not Is_List_Member (Parent (N));
728 -- OK, return statement is in a statement list, look for raise
734 -- Skip past N_Freeze_Entity nodes generated by expansion
736 Nod := Prev (Parent (N));
738 and then Nkind (Nod) = N_Freeze_Entity
743 -- If no raise statement, give warning
745 exit when Nkind (Nod) /= N_Raise_Statement
747 (Nkind (Nod) not in N_Raise_xxx_Error
748 or else Present (Condition (Nod)));
759 Error_Msg_N ("possible infinite recursion?", N);
760 Error_Msg_N ("\Storage_Error may be raised at run time?", N);
763 end Check_Infinite_Recursion;
765 -------------------------------
766 -- Check_Initialization_Call --
767 -------------------------------
769 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
770 Typ : constant Entity_Id := Etype (First_Formal (Nam));
772 function Uses_SS (T : Entity_Id) return Boolean;
773 -- Check whether the creation of an object of the type will involve
774 -- use of the secondary stack. If T is a record type, this is true
775 -- if the expression for some component uses the secondary stack, eg.
776 -- through a call to a function that returns an unconstrained value.
777 -- False if T is controlled, because cleanups occur elsewhere.
783 function Uses_SS (T : Entity_Id) return Boolean is
788 if Is_Controlled (T) then
791 elsif Is_Array_Type (T) then
792 return Uses_SS (Component_Type (T));
794 elsif Is_Record_Type (T) then
795 Comp := First_Component (T);
796 while Present (Comp) loop
797 if Ekind (Comp) = E_Component
798 and then Nkind (Parent (Comp)) = N_Component_Declaration
800 Expr := Expression (Parent (Comp));
802 -- The expression for a dynamic component may be
803 -- rewritten as a dereference. Retrieve original
806 if Nkind (Original_Node (Expr)) = N_Function_Call
807 and then Requires_Transient_Scope (Etype (Expr))
811 elsif Uses_SS (Etype (Comp)) then
816 Next_Component (Comp);
826 -- Start of processing for Check_Initialization_Call
829 -- Establish a transient scope if the type needs it
831 if Uses_SS (Typ) then
832 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
834 end Check_Initialization_Call;
836 ------------------------------
837 -- Check_Parameterless_Call --
838 ------------------------------
840 procedure Check_Parameterless_Call (N : Node_Id) is
843 function Prefix_Is_Access_Subp return Boolean;
844 -- If the prefix is of an access_to_subprogram type, the node must be
845 -- rewritten as a call. Ditto if the prefix is overloaded and all its
846 -- interpretations are access to subprograms.
848 ---------------------------
849 -- Prefix_Is_Access_Subp --
850 ---------------------------
852 function Prefix_Is_Access_Subp return Boolean is
857 if not Is_Overloaded (N) then
859 Ekind (Etype (N)) = E_Subprogram_Type
860 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
862 Get_First_Interp (N, I, It);
863 while Present (It.Typ) loop
864 if Ekind (It.Typ) /= E_Subprogram_Type
865 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
870 Get_Next_Interp (I, It);
875 end Prefix_Is_Access_Subp;
877 -- Start of processing for Check_Parameterless_Call
880 -- Defend against junk stuff if errors already detected
882 if Total_Errors_Detected /= 0 then
883 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
885 elsif Nkind (N) in N_Has_Chars
886 and then Chars (N) in Error_Name_Or_No_Name
894 -- If the context expects a value, and the name is a procedure,
895 -- this is most likely a missing 'Access. Do not try to resolve
896 -- the parameterless call, error will be caught when the outer
899 if Is_Entity_Name (N)
900 and then Ekind (Entity (N)) = E_Procedure
901 and then not Is_Overloaded (N)
903 (Nkind (Parent (N)) = N_Parameter_Association
904 or else Nkind (Parent (N)) = N_Function_Call
905 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
910 -- Rewrite as call if overloadable entity that is (or could be, in
911 -- the overloaded case) a function call. If we know for sure that
912 -- the entity is an enumeration literal, we do not rewrite it.
914 if (Is_Entity_Name (N)
915 and then Is_Overloadable (Entity (N))
916 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
917 or else Is_Overloaded (N)))
919 -- Rewrite as call if it is an explicit deference of an expression of
920 -- a subprogram access type, and the suprogram type is not that of a
921 -- procedure or entry.
924 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
926 -- Rewrite as call if it is a selected component which is a function,
927 -- this is the case of a call to a protected function (which may be
928 -- overloaded with other protected operations).
931 (Nkind (N) = N_Selected_Component
932 and then (Ekind (Entity (Selector_Name (N))) = E_Function
934 ((Ekind (Entity (Selector_Name (N))) = E_Entry
936 Ekind (Entity (Selector_Name (N))) = E_Procedure)
937 and then Is_Overloaded (Selector_Name (N)))))
939 -- If one of the above three conditions is met, rewrite as call.
940 -- Apply the rewriting only once.
943 if Nkind (Parent (N)) /= N_Function_Call
944 or else N /= Name (Parent (N))
948 -- If overloaded, overload set belongs to new copy
950 Save_Interps (N, Nam);
952 -- Change node to parameterless function call (note that the
953 -- Parameter_Associations associations field is left set to Empty,
954 -- its normal default value since there are no parameters)
956 Change_Node (N, N_Function_Call);
958 Set_Sloc (N, Sloc (Nam));
962 elsif Nkind (N) = N_Parameter_Association then
963 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
965 end Check_Parameterless_Call;
967 ----------------------
968 -- Is_Predefined_Op --
969 ----------------------
971 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
973 return Is_Intrinsic_Subprogram (Nam)
974 and then not Is_Generic_Instance (Nam)
975 and then Chars (Nam) in Any_Operator_Name
976 and then (No (Alias (Nam))
977 or else Is_Predefined_Op (Alias (Nam)));
978 end Is_Predefined_Op;
980 -----------------------------
981 -- Make_Call_Into_Operator --
982 -----------------------------
984 procedure Make_Call_Into_Operator
989 Op_Name : constant Name_Id := Chars (Op_Id);
990 Act1 : Node_Id := First_Actual (N);
991 Act2 : Node_Id := Next_Actual (Act1);
992 Error : Boolean := False;
993 Func : constant Entity_Id := Entity (Name (N));
994 Is_Binary : constant Boolean := Present (Act2);
996 Opnd_Type : Entity_Id;
997 Orig_Type : Entity_Id := Empty;
1000 type Kind_Test is access function (E : Entity_Id) return Boolean;
1002 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
1003 -- Determine whether E is an access type declared by an access decla-
1004 -- ration, and not an (anonymous) allocator type.
1006 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1007 -- If the operand is not universal, and the operator is given by a
1008 -- expanded name, verify that the operand has an interpretation with
1009 -- a type defined in the given scope of the operator.
1011 function Type_In_P (Test : Kind_Test) return Entity_Id;
1012 -- Find a type of the given class in the package Pack that contains
1015 -----------------------------
1016 -- Is_Definite_Access_Type --
1017 -----------------------------
1019 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1020 Btyp : constant Entity_Id := Base_Type (E);
1022 return Ekind (Btyp) = E_Access_Type
1023 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1024 and then Comes_From_Source (Btyp));
1025 end Is_Definite_Access_Type;
1027 ---------------------------
1028 -- Operand_Type_In_Scope --
1029 ---------------------------
1031 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1032 Nod : constant Node_Id := Right_Opnd (Op_Node);
1037 if not Is_Overloaded (Nod) then
1038 return Scope (Base_Type (Etype (Nod))) = S;
1041 Get_First_Interp (Nod, I, It);
1042 while Present (It.Typ) loop
1043 if Scope (Base_Type (It.Typ)) = S then
1047 Get_Next_Interp (I, It);
1052 end Operand_Type_In_Scope;
1058 function Type_In_P (Test : Kind_Test) return Entity_Id is
1061 function In_Decl return Boolean;
1062 -- Verify that node is not part of the type declaration for the
1063 -- candidate type, which would otherwise be invisible.
1069 function In_Decl return Boolean is
1070 Decl_Node : constant Node_Id := Parent (E);
1076 if Etype (E) = Any_Type then
1079 elsif No (Decl_Node) then
1084 and then Nkind (N2) /= N_Compilation_Unit
1086 if N2 = Decl_Node then
1097 -- Start of processing for Type_In_P
1100 -- If the context type is declared in the prefix package, this
1101 -- is the desired base type.
1103 if Scope (Base_Type (Typ)) = Pack
1106 return Base_Type (Typ);
1109 E := First_Entity (Pack);
1110 while Present (E) loop
1112 and then not In_Decl
1124 -- Start of processing for Make_Call_Into_Operator
1127 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1132 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1133 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1134 Save_Interps (Act1, Left_Opnd (Op_Node));
1135 Save_Interps (Act2, Right_Opnd (Op_Node));
1136 Act1 := Left_Opnd (Op_Node);
1137 Act2 := Right_Opnd (Op_Node);
1142 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1143 Save_Interps (Act1, Right_Opnd (Op_Node));
1144 Act1 := Right_Opnd (Op_Node);
1147 -- If the operator is denoted by an expanded name, and the prefix is
1148 -- not Standard, but the operator is a predefined one whose scope is
1149 -- Standard, then this is an implicit_operator, inserted as an
1150 -- interpretation by the procedure of the same name. This procedure
1151 -- overestimates the presence of implicit operators, because it does
1152 -- not examine the type of the operands. Verify now that the operand
1153 -- type appears in the given scope. If right operand is universal,
1154 -- check the other operand. In the case of concatenation, either
1155 -- argument can be the component type, so check the type of the result.
1156 -- If both arguments are literals, look for a type of the right kind
1157 -- defined in the given scope. This elaborate nonsense is brought to
1158 -- you courtesy of b33302a. The type itself must be frozen, so we must
1159 -- find the type of the proper class in the given scope.
1161 -- A final wrinkle is the multiplication operator for fixed point
1162 -- types, which is defined in Standard only, and not in the scope of
1163 -- the fixed_point type itself.
1165 if Nkind (Name (N)) = N_Expanded_Name then
1166 Pack := Entity (Prefix (Name (N)));
1168 -- If the entity being called is defined in the given package,
1169 -- it is a renaming of a predefined operator, and known to be
1172 if Scope (Entity (Name (N))) = Pack
1173 and then Pack /= Standard_Standard
1177 -- Visibility does not need to be checked in an instance: if the
1178 -- operator was not visible in the generic it has been diagnosed
1179 -- already, else there is an implicit copy of it in the instance.
1181 elsif In_Instance then
1184 elsif (Op_Name = Name_Op_Multiply
1185 or else Op_Name = Name_Op_Divide)
1186 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1187 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1189 if Pack /= Standard_Standard then
1193 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1196 elsif Ada_Version >= Ada_05
1197 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1198 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1203 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1205 if Op_Name = Name_Op_Concat then
1206 Opnd_Type := Base_Type (Typ);
1208 elsif (Scope (Opnd_Type) = Standard_Standard
1210 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1212 and then not Comes_From_Source (Opnd_Type))
1214 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1217 if Scope (Opnd_Type) = Standard_Standard then
1219 -- Verify that the scope contains a type that corresponds to
1220 -- the given literal. Optimize the case where Pack is Standard.
1222 if Pack /= Standard_Standard then
1224 if Opnd_Type = Universal_Integer then
1225 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1227 elsif Opnd_Type = Universal_Real then
1228 Orig_Type := Type_In_P (Is_Real_Type'Access);
1230 elsif Opnd_Type = Any_String then
1231 Orig_Type := Type_In_P (Is_String_Type'Access);
1233 elsif Opnd_Type = Any_Access then
1234 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1236 elsif Opnd_Type = Any_Composite then
1237 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1239 if Present (Orig_Type) then
1240 if Has_Private_Component (Orig_Type) then
1243 Set_Etype (Act1, Orig_Type);
1246 Set_Etype (Act2, Orig_Type);
1255 Error := No (Orig_Type);
1258 elsif Ekind (Opnd_Type) = E_Allocator_Type
1259 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1263 -- If the type is defined elsewhere, and the operator is not
1264 -- defined in the given scope (by a renaming declaration, e.g.)
1265 -- then this is an error as well. If an extension of System is
1266 -- present, and the type may be defined there, Pack must be
1269 elsif Scope (Opnd_Type) /= Pack
1270 and then Scope (Op_Id) /= Pack
1271 and then (No (System_Aux_Id)
1272 or else Scope (Opnd_Type) /= System_Aux_Id
1273 or else Pack /= Scope (System_Aux_Id))
1275 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1278 Error := not Operand_Type_In_Scope (Pack);
1281 elsif Pack = Standard_Standard
1282 and then not Operand_Type_In_Scope (Standard_Standard)
1289 Error_Msg_Node_2 := Pack;
1291 ("& not declared in&", N, Selector_Name (Name (N)));
1292 Set_Etype (N, Any_Type);
1297 Set_Chars (Op_Node, Op_Name);
1299 if not Is_Private_Type (Etype (N)) then
1300 Set_Etype (Op_Node, Base_Type (Etype (N)));
1302 Set_Etype (Op_Node, Etype (N));
1305 -- If this is a call to a function that renames a predefined equality,
1306 -- the renaming declaration provides a type that must be used to
1307 -- resolve the operands. This must be done now because resolution of
1308 -- the equality node will not resolve any remaining ambiguity, and it
1309 -- assumes that the first operand is not overloaded.
1311 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1312 and then Ekind (Func) = E_Function
1313 and then Is_Overloaded (Act1)
1315 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1316 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1319 Set_Entity (Op_Node, Op_Id);
1320 Generate_Reference (Op_Id, N, ' ');
1321 Rewrite (N, Op_Node);
1323 -- If this is an arithmetic operator and the result type is private,
1324 -- the operands and the result must be wrapped in conversion to
1325 -- expose the underlying numeric type and expand the proper checks,
1326 -- e.g. on division.
1328 if Is_Private_Type (Typ) then
1330 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1331 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1332 Resolve_Intrinsic_Operator (N, Typ);
1334 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1335 Resolve_Intrinsic_Unary_Operator (N, Typ);
1344 -- For predefined operators on literals, the operation freezes
1347 if Present (Orig_Type) then
1348 Set_Etype (Act1, Orig_Type);
1349 Freeze_Expression (Act1);
1351 end Make_Call_Into_Operator;
1357 function Operator_Kind
1359 Is_Binary : Boolean) return Node_Kind
1365 if Op_Name = Name_Op_And then Kind := N_Op_And;
1366 elsif Op_Name = Name_Op_Or then Kind := N_Op_Or;
1367 elsif Op_Name = Name_Op_Xor then Kind := N_Op_Xor;
1368 elsif Op_Name = Name_Op_Eq then Kind := N_Op_Eq;
1369 elsif Op_Name = Name_Op_Ne then Kind := N_Op_Ne;
1370 elsif Op_Name = Name_Op_Lt then Kind := N_Op_Lt;
1371 elsif Op_Name = Name_Op_Le then Kind := N_Op_Le;
1372 elsif Op_Name = Name_Op_Gt then Kind := N_Op_Gt;
1373 elsif Op_Name = Name_Op_Ge then Kind := N_Op_Ge;
1374 elsif Op_Name = Name_Op_Add then Kind := N_Op_Add;
1375 elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Subtract;
1376 elsif Op_Name = Name_Op_Concat then Kind := N_Op_Concat;
1377 elsif Op_Name = Name_Op_Multiply then Kind := N_Op_Multiply;
1378 elsif Op_Name = Name_Op_Divide then Kind := N_Op_Divide;
1379 elsif Op_Name = Name_Op_Mod then Kind := N_Op_Mod;
1380 elsif Op_Name = Name_Op_Rem then Kind := N_Op_Rem;
1381 elsif Op_Name = Name_Op_Expon then Kind := N_Op_Expon;
1383 raise Program_Error;
1389 if Op_Name = Name_Op_Add then Kind := N_Op_Plus;
1390 elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Minus;
1391 elsif Op_Name = Name_Op_Abs then Kind := N_Op_Abs;
1392 elsif Op_Name = Name_Op_Not then Kind := N_Op_Not;
1394 raise Program_Error;
1401 -----------------------------
1402 -- Pre_Analyze_And_Resolve --
1403 -----------------------------
1405 procedure Pre_Analyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1406 Save_Full_Analysis : constant Boolean := Full_Analysis;
1409 Full_Analysis := False;
1410 Expander_Mode_Save_And_Set (False);
1412 -- We suppress all checks for this analysis, since the checks will
1413 -- be applied properly, and in the right location, when the default
1414 -- expression is reanalyzed and reexpanded later on.
1416 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1418 Expander_Mode_Restore;
1419 Full_Analysis := Save_Full_Analysis;
1420 end Pre_Analyze_And_Resolve;
1422 -- Version without context type
1424 procedure Pre_Analyze_And_Resolve (N : Node_Id) is
1425 Save_Full_Analysis : constant Boolean := Full_Analysis;
1428 Full_Analysis := False;
1429 Expander_Mode_Save_And_Set (False);
1432 Resolve (N, Etype (N), Suppress => All_Checks);
1434 Expander_Mode_Restore;
1435 Full_Analysis := Save_Full_Analysis;
1436 end Pre_Analyze_And_Resolve;
1438 ----------------------------------
1439 -- Replace_Actual_Discriminants --
1440 ----------------------------------
1442 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1443 Loc : constant Source_Ptr := Sloc (N);
1444 Tsk : Node_Id := Empty;
1446 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1452 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1456 if Nkind (Nod) = N_Identifier then
1457 Ent := Entity (Nod);
1460 and then Ekind (Ent) = E_Discriminant
1463 Make_Selected_Component (Loc,
1464 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1465 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1467 Set_Etype (Nod, Etype (Ent));
1475 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1477 -- Start of processing for Replace_Actual_Discriminants
1480 if not Expander_Active then
1484 if Nkind (Name (N)) = N_Selected_Component then
1485 Tsk := Prefix (Name (N));
1487 elsif Nkind (Name (N)) = N_Indexed_Component then
1488 Tsk := Prefix (Prefix (Name (N)));
1494 Replace_Discrs (Default);
1496 end Replace_Actual_Discriminants;
1502 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1504 I1 : Interp_Index := 0; -- prevent junk warning
1507 Found : Boolean := False;
1508 Seen : Entity_Id := Empty; -- prevent junk warning
1509 Ctx_Type : Entity_Id := Typ;
1510 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1511 Err_Type : Entity_Id := Empty;
1512 Ambiguous : Boolean := False;
1514 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1515 -- Try and fix up a literal so that it matches its expected type. New
1516 -- literals are manufactured if necessary to avoid cascaded errors.
1518 procedure Resolution_Failed;
1519 -- Called when attempt at resolving current expression fails
1521 --------------------
1522 -- Patch_Up_Value --
1523 --------------------
1525 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1527 if Nkind (N) = N_Integer_Literal
1528 and then Is_Real_Type (Typ)
1531 Make_Real_Literal (Sloc (N),
1532 Realval => UR_From_Uint (Intval (N))));
1533 Set_Etype (N, Universal_Real);
1534 Set_Is_Static_Expression (N);
1536 elsif Nkind (N) = N_Real_Literal
1537 and then Is_Integer_Type (Typ)
1540 Make_Integer_Literal (Sloc (N),
1541 Intval => UR_To_Uint (Realval (N))));
1542 Set_Etype (N, Universal_Integer);
1543 Set_Is_Static_Expression (N);
1544 elsif Nkind (N) = N_String_Literal
1545 and then Is_Character_Type (Typ)
1547 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1549 Make_Character_Literal (Sloc (N),
1551 Char_Literal_Value =>
1552 UI_From_Int (Character'Pos ('A'))));
1553 Set_Etype (N, Any_Character);
1554 Set_Is_Static_Expression (N);
1556 elsif Nkind (N) /= N_String_Literal
1557 and then Is_String_Type (Typ)
1560 Make_String_Literal (Sloc (N),
1561 Strval => End_String));
1563 elsif Nkind (N) = N_Range then
1564 Patch_Up_Value (Low_Bound (N), Typ);
1565 Patch_Up_Value (High_Bound (N), Typ);
1569 -----------------------
1570 -- Resolution_Failed --
1571 -----------------------
1573 procedure Resolution_Failed is
1575 Patch_Up_Value (N, Typ);
1577 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1578 Set_Is_Overloaded (N, False);
1580 -- The caller will return without calling the expander, so we need
1581 -- to set the analyzed flag. Note that it is fine to set Analyzed
1582 -- to True even if we are in the middle of a shallow analysis,
1583 -- (see the spec of sem for more details) since this is an error
1584 -- situation anyway, and there is no point in repeating the
1585 -- analysis later (indeed it won't work to repeat it later, since
1586 -- we haven't got a clear resolution of which entity is being
1589 Set_Analyzed (N, True);
1591 end Resolution_Failed;
1593 -- Start of processing for Resolve
1600 -- Access attribute on remote subprogram cannot be used for
1601 -- a non-remote access-to-subprogram type.
1603 if Nkind (N) = N_Attribute_Reference
1604 and then (Attribute_Name (N) = Name_Access
1605 or else Attribute_Name (N) = Name_Unrestricted_Access
1606 or else Attribute_Name (N) = Name_Unchecked_Access)
1607 and then Comes_From_Source (N)
1608 and then Is_Entity_Name (Prefix (N))
1609 and then Is_Subprogram (Entity (Prefix (N)))
1610 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1611 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1614 ("prefix must statically denote a non-remote subprogram", N);
1617 -- If the context is a Remote_Access_To_Subprogram, access attributes
1618 -- must be resolved with the corresponding fat pointer. There is no need
1619 -- to check for the attribute name since the return type of an
1620 -- attribute is never a remote type.
1622 if Nkind (N) = N_Attribute_Reference
1623 and then Comes_From_Source (N)
1624 and then (Is_Remote_Call_Interface (Typ)
1625 or else Is_Remote_Types (Typ))
1628 Attr : constant Attribute_Id :=
1629 Get_Attribute_Id (Attribute_Name (N));
1630 Pref : constant Node_Id := Prefix (N);
1633 Is_Remote : Boolean := True;
1636 -- Check that Typ is a remote access-to-subprogram type
1638 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1639 -- Prefix (N) must statically denote a remote subprogram
1640 -- declared in a package specification.
1642 if Attr = Attribute_Access then
1643 Decl := Unit_Declaration_Node (Entity (Pref));
1645 if Nkind (Decl) = N_Subprogram_Body then
1646 Spec := Corresponding_Spec (Decl);
1648 if not No (Spec) then
1649 Decl := Unit_Declaration_Node (Spec);
1653 Spec := Parent (Decl);
1655 if not Is_Entity_Name (Prefix (N))
1656 or else Nkind (Spec) /= N_Package_Specification
1658 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1662 ("prefix must statically denote a remote subprogram ",
1667 -- If we are generating code for a distributed program.
1668 -- perform semantic checks against the corresponding
1671 if (Attr = Attribute_Access
1672 or else Attr = Attribute_Unchecked_Access
1673 or else Attr = Attribute_Unrestricted_Access)
1674 and then Expander_Active
1675 and then Get_PCS_Name /= Name_No_DSA
1677 Check_Subtype_Conformant
1678 (New_Id => Entity (Prefix (N)),
1679 Old_Id => Designated_Type
1680 (Corresponding_Remote_Type (Typ)),
1683 Process_Remote_AST_Attribute (N, Typ);
1690 Debug_A_Entry ("resolving ", N);
1692 if Comes_From_Source (N) then
1693 if Is_Fixed_Point_Type (Typ) then
1694 Check_Restriction (No_Fixed_Point, N);
1696 elsif Is_Floating_Point_Type (Typ)
1697 and then Typ /= Universal_Real
1698 and then Typ /= Any_Real
1700 Check_Restriction (No_Floating_Point, N);
1704 -- Return if already analyzed
1706 if Analyzed (N) then
1707 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1710 -- Return if type = Any_Type (previous error encountered)
1712 elsif Etype (N) = Any_Type then
1713 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1717 Check_Parameterless_Call (N);
1719 -- If not overloaded, then we know the type, and all that needs doing
1720 -- is to check that this type is compatible with the context.
1722 if not Is_Overloaded (N) then
1723 Found := Covers (Typ, Etype (N));
1724 Expr_Type := Etype (N);
1726 -- In the overloaded case, we must select the interpretation that
1727 -- is compatible with the context (i.e. the type passed to Resolve)
1730 -- Loop through possible interpretations
1732 Get_First_Interp (N, I, It);
1733 Interp_Loop : while Present (It.Typ) loop
1735 -- We are only interested in interpretations that are compatible
1736 -- with the expected type, any other interpretations are ignored
1738 if not Covers (Typ, It.Typ) then
1739 if Debug_Flag_V then
1740 Write_Str (" interpretation incompatible with context");
1745 -- First matching interpretation
1751 Expr_Type := It.Typ;
1753 -- Matching interpretation that is not the first, maybe an
1754 -- error, but there are some cases where preference rules are
1755 -- used to choose between the two possibilities. These and
1756 -- some more obscure cases are handled in Disambiguate.
1759 Error_Msg_Sloc := Sloc (Seen);
1760 It1 := Disambiguate (N, I1, I, Typ);
1762 -- Disambiguation has succeeded. Skip the remaining
1765 if It1 /= No_Interp then
1767 Expr_Type := It1.Typ;
1769 while Present (It.Typ) loop
1770 Get_Next_Interp (I, It);
1774 -- Before we issue an ambiguity complaint, check for
1775 -- the case of a subprogram call where at least one
1776 -- of the arguments is Any_Type, and if so, suppress
1777 -- the message, since it is a cascaded error.
1779 if Nkind (N) = N_Function_Call
1780 or else Nkind (N) = N_Procedure_Call_Statement
1787 A := First_Actual (N);
1788 while Present (A) loop
1791 if Nkind (E) = N_Parameter_Association then
1792 E := Explicit_Actual_Parameter (E);
1795 if Etype (E) = Any_Type then
1796 if Debug_Flag_V then
1797 Write_Str ("Any_Type in call");
1808 elsif Nkind (N) in N_Binary_Op
1809 and then (Etype (Left_Opnd (N)) = Any_Type
1810 or else Etype (Right_Opnd (N)) = Any_Type)
1814 elsif Nkind (N) in N_Unary_Op
1815 and then Etype (Right_Opnd (N)) = Any_Type
1820 -- Not that special case, so issue message using the
1821 -- flag Ambiguous to control printing of the header
1822 -- message only at the start of an ambiguous set.
1824 if not Ambiguous then
1825 if Nkind (N) = N_Function_Call
1826 and then Nkind (Name (N)) = N_Explicit_Dereference
1829 ("ambiguous expression "
1830 & "(cannot resolve indirect call)!", N);
1833 ("ambiguous expression (cannot resolve&)!",
1839 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
1841 ("\\possible interpretation (inherited)#!", N);
1843 Error_Msg_N ("\\possible interpretation#!", N);
1847 Error_Msg_Sloc := Sloc (It.Nam);
1849 -- By default, the error message refers to the candidate
1850 -- interpretation. But if it is a predefined operator, it
1851 -- is implicitly declared at the declaration of the type
1852 -- of the operand. Recover the sloc of that declaration
1853 -- for the error message.
1855 if Nkind (N) in N_Op
1856 and then Scope (It.Nam) = Standard_Standard
1857 and then not Is_Overloaded (Right_Opnd (N))
1858 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
1861 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
1863 if Comes_From_Source (Err_Type)
1864 and then Present (Parent (Err_Type))
1866 Error_Msg_Sloc := Sloc (Parent (Err_Type));
1869 elsif Nkind (N) in N_Binary_Op
1870 and then Scope (It.Nam) = Standard_Standard
1871 and then not Is_Overloaded (Left_Opnd (N))
1872 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
1875 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
1877 if Comes_From_Source (Err_Type)
1878 and then Present (Parent (Err_Type))
1880 Error_Msg_Sloc := Sloc (Parent (Err_Type));
1883 -- If this is an indirect call, use the subprogram_type
1884 -- in the message, to have a meaningful location.
1885 -- Indicate as well if this is an inherited operation,
1886 -- created by a type declaration.
1888 elsif Nkind (N) = N_Function_Call
1889 and then Nkind (Name (N)) = N_Explicit_Dereference
1890 and then Is_Type (It.Nam)
1894 Sloc (Associated_Node_For_Itype (Err_Type));
1899 if Nkind (N) in N_Op
1900 and then Scope (It.Nam) = Standard_Standard
1901 and then Present (Err_Type)
1904 ("\\possible interpretation (predefined)#!", N);
1907 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
1910 ("\\possible interpretation (inherited)#!", N);
1912 Error_Msg_N ("\\possible interpretation#!", N);
1918 -- We have a matching interpretation, Expr_Type is the type
1919 -- from this interpretation, and Seen is the entity.
1921 -- For an operator, just set the entity name. The type will be
1922 -- set by the specific operator resolution routine.
1924 if Nkind (N) in N_Op then
1925 Set_Entity (N, Seen);
1926 Generate_Reference (Seen, N);
1928 elsif Nkind (N) = N_Character_Literal then
1929 Set_Etype (N, Expr_Type);
1931 -- For an explicit dereference, attribute reference, range,
1932 -- short-circuit form (which is not an operator node), or call
1933 -- with a name that is an explicit dereference, there is
1934 -- nothing to be done at this point.
1936 elsif Nkind (N) = N_Explicit_Dereference
1937 or else Nkind (N) = N_Attribute_Reference
1938 or else Nkind (N) = N_And_Then
1939 or else Nkind (N) = N_Indexed_Component
1940 or else Nkind (N) = N_Or_Else
1941 or else Nkind (N) = N_Range
1942 or else Nkind (N) = N_Selected_Component
1943 or else Nkind (N) = N_Slice
1944 or else Nkind (Name (N)) = N_Explicit_Dereference
1948 -- For procedure or function calls, set the type of the name,
1949 -- and also the entity pointer for the prefix
1951 elsif (Nkind (N) = N_Procedure_Call_Statement
1952 or else Nkind (N) = N_Function_Call)
1953 and then (Is_Entity_Name (Name (N))
1954 or else Nkind (Name (N)) = N_Operator_Symbol)
1956 Set_Etype (Name (N), Expr_Type);
1957 Set_Entity (Name (N), Seen);
1958 Generate_Reference (Seen, Name (N));
1960 elsif Nkind (N) = N_Function_Call
1961 and then Nkind (Name (N)) = N_Selected_Component
1963 Set_Etype (Name (N), Expr_Type);
1964 Set_Entity (Selector_Name (Name (N)), Seen);
1965 Generate_Reference (Seen, Selector_Name (Name (N)));
1967 -- For all other cases, just set the type of the Name
1970 Set_Etype (Name (N), Expr_Type);
1975 -- Move to next interpretation
1977 exit Interp_Loop when No (It.Typ);
1979 Get_Next_Interp (I, It);
1980 end loop Interp_Loop;
1983 -- At this stage Found indicates whether or not an acceptable
1984 -- interpretation exists. If not, then we have an error, except
1985 -- that if the context is Any_Type as a result of some other error,
1986 -- then we suppress the error report.
1989 if Typ /= Any_Type then
1991 -- If type we are looking for is Void, then this is the procedure
1992 -- call case, and the error is simply that what we gave is not a
1993 -- procedure name (we think of procedure calls as expressions with
1994 -- types internally, but the user doesn't think of them this way!)
1996 if Typ = Standard_Void_Type then
1998 -- Special case message if function used as a procedure
2000 if Nkind (N) = N_Procedure_Call_Statement
2001 and then Is_Entity_Name (Name (N))
2002 and then Ekind (Entity (Name (N))) = E_Function
2005 ("cannot use function & in a procedure call",
2006 Name (N), Entity (Name (N)));
2008 -- Otherwise give general message (not clear what cases this
2009 -- covers, but no harm in providing for them!)
2012 Error_Msg_N ("expect procedure name in procedure call", N);
2017 -- Otherwise we do have a subexpression with the wrong type
2019 -- Check for the case of an allocator which uses an access type
2020 -- instead of the designated type. This is a common error and we
2021 -- specialize the message, posting an error on the operand of the
2022 -- allocator, complaining that we expected the designated type of
2025 elsif Nkind (N) = N_Allocator
2026 and then Ekind (Typ) in Access_Kind
2027 and then Ekind (Etype (N)) in Access_Kind
2028 and then Designated_Type (Etype (N)) = Typ
2030 Wrong_Type (Expression (N), Designated_Type (Typ));
2033 -- Check for view mismatch on Null in instances, for which the
2034 -- view-swapping mechanism has no identifier.
2036 elsif (In_Instance or else In_Inlined_Body)
2037 and then (Nkind (N) = N_Null)
2038 and then Is_Private_Type (Typ)
2039 and then Is_Access_Type (Full_View (Typ))
2041 Resolve (N, Full_View (Typ));
2045 -- Check for an aggregate. Sometimes we can get bogus aggregates
2046 -- from misuse of parentheses, and we are about to complain about
2047 -- the aggregate without even looking inside it.
2049 -- Instead, if we have an aggregate of type Any_Composite, then
2050 -- analyze and resolve the component fields, and then only issue
2051 -- another message if we get no errors doing this (otherwise
2052 -- assume that the errors in the aggregate caused the problem).
2054 elsif Nkind (N) = N_Aggregate
2055 and then Etype (N) = Any_Composite
2057 -- Disable expansion in any case. If there is a type mismatch
2058 -- it may be fatal to try to expand the aggregate. The flag
2059 -- would otherwise be set to false when the error is posted.
2061 Expander_Active := False;
2064 procedure Check_Aggr (Aggr : Node_Id);
2065 -- Check one aggregate, and set Found to True if we have a
2066 -- definite error in any of its elements
2068 procedure Check_Elmt (Aelmt : Node_Id);
2069 -- Check one element of aggregate and set Found to True if
2070 -- we definitely have an error in the element.
2076 procedure Check_Aggr (Aggr : Node_Id) is
2080 if Present (Expressions (Aggr)) then
2081 Elmt := First (Expressions (Aggr));
2082 while Present (Elmt) loop
2088 if Present (Component_Associations (Aggr)) then
2089 Elmt := First (Component_Associations (Aggr));
2090 while Present (Elmt) loop
2092 -- If this is a default-initialized component, then
2093 -- there is nothing to check. The box will be
2094 -- replaced by the appropriate call during late
2097 if not Box_Present (Elmt) then
2098 Check_Elmt (Expression (Elmt));
2110 procedure Check_Elmt (Aelmt : Node_Id) is
2112 -- If we have a nested aggregate, go inside it (to
2113 -- attempt a naked analyze-resolve of the aggregate
2114 -- can cause undesirable cascaded errors). Do not
2115 -- resolve expression if it needs a type from context,
2116 -- as for integer * fixed expression.
2118 if Nkind (Aelmt) = N_Aggregate then
2124 if not Is_Overloaded (Aelmt)
2125 and then Etype (Aelmt) /= Any_Fixed
2130 if Etype (Aelmt) = Any_Type then
2141 -- If an error message was issued already, Found got reset
2142 -- to True, so if it is still False, issue the standard
2143 -- Wrong_Type message.
2146 if Is_Overloaded (N)
2147 and then Nkind (N) = N_Function_Call
2150 Subp_Name : Node_Id;
2152 if Is_Entity_Name (Name (N)) then
2153 Subp_Name := Name (N);
2155 elsif Nkind (Name (N)) = N_Selected_Component then
2157 -- Protected operation: retrieve operation name
2159 Subp_Name := Selector_Name (Name (N));
2161 raise Program_Error;
2164 Error_Msg_Node_2 := Typ;
2165 Error_Msg_NE ("no visible interpretation of&" &
2166 " matches expected type&", N, Subp_Name);
2169 if All_Errors_Mode then
2171 Index : Interp_Index;
2175 Error_Msg_N ("\\possible interpretations:", N);
2177 Get_First_Interp (Name (N), Index, It);
2178 while Present (It.Nam) loop
2179 Error_Msg_Sloc := Sloc (It.Nam);
2180 Error_Msg_Node_2 := It.Typ;
2181 Error_Msg_NE ("\& declared#, type&", N, It.Nam);
2182 Get_Next_Interp (Index, It);
2186 Error_Msg_N ("\use -gnatf for details", N);
2189 Wrong_Type (N, Typ);
2197 -- Test if we have more than one interpretation for the context
2199 elsif Ambiguous then
2203 -- Here we have an acceptable interpretation for the context
2206 -- Propagate type information and normalize tree for various
2207 -- predefined operations. If the context only imposes a class of
2208 -- types, rather than a specific type, propagate the actual type
2211 if Typ = Any_Integer
2212 or else Typ = Any_Boolean
2213 or else Typ = Any_Modular
2214 or else Typ = Any_Real
2215 or else Typ = Any_Discrete
2217 Ctx_Type := Expr_Type;
2219 -- Any_Fixed is legal in a real context only if a specific
2220 -- fixed point type is imposed. If Norman Cohen can be
2221 -- confused by this, it deserves a separate message.
2224 and then Expr_Type = Any_Fixed
2226 Error_Msg_N ("illegal context for mixed mode operation", N);
2227 Set_Etype (N, Universal_Real);
2228 Ctx_Type := Universal_Real;
2232 -- A user-defined operator is tranformed into a function call at
2233 -- this point, so that further processing knows that operators are
2234 -- really operators (i.e. are predefined operators). User-defined
2235 -- operators that are intrinsic are just renamings of the predefined
2236 -- ones, and need not be turned into calls either, but if they rename
2237 -- a different operator, we must transform the node accordingly.
2238 -- Instantiations of Unchecked_Conversion are intrinsic but are
2239 -- treated as functions, even if given an operator designator.
2241 if Nkind (N) in N_Op
2242 and then Present (Entity (N))
2243 and then Ekind (Entity (N)) /= E_Operator
2246 if not Is_Predefined_Op (Entity (N)) then
2247 Rewrite_Operator_As_Call (N, Entity (N));
2249 elsif Present (Alias (Entity (N)))
2251 Nkind (Parent (Parent (Entity (N))))
2252 = N_Subprogram_Renaming_Declaration
2254 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2256 -- If the node is rewritten, it will be fully resolved in
2257 -- Rewrite_Renamed_Operator.
2259 if Analyzed (N) then
2265 case N_Subexpr'(Nkind (N)) is
2267 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2269 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2271 when N_And_Then | N_Or_Else
2272 => Resolve_Short_Circuit (N, Ctx_Type);
2274 when N_Attribute_Reference
2275 => Resolve_Attribute (N, Ctx_Type);
2277 when N_Character_Literal
2278 => Resolve_Character_Literal (N, Ctx_Type);
2280 when N_Conditional_Expression
2281 => Resolve_Conditional_Expression (N, Ctx_Type);
2283 when N_Expanded_Name
2284 => Resolve_Entity_Name (N, Ctx_Type);
2286 when N_Extension_Aggregate
2287 => Resolve_Extension_Aggregate (N, Ctx_Type);
2289 when N_Explicit_Dereference
2290 => Resolve_Explicit_Dereference (N, Ctx_Type);
2292 when N_Function_Call
2293 => Resolve_Call (N, Ctx_Type);
2296 => Resolve_Entity_Name (N, Ctx_Type);
2298 when N_Indexed_Component
2299 => Resolve_Indexed_Component (N, Ctx_Type);
2301 when N_Integer_Literal
2302 => Resolve_Integer_Literal (N, Ctx_Type);
2304 when N_Membership_Test
2305 => Resolve_Membership_Op (N, Ctx_Type);
2307 when N_Null => Resolve_Null (N, Ctx_Type);
2309 when N_Op_And | N_Op_Or | N_Op_Xor
2310 => Resolve_Logical_Op (N, Ctx_Type);
2312 when N_Op_Eq | N_Op_Ne
2313 => Resolve_Equality_Op (N, Ctx_Type);
2315 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2316 => Resolve_Comparison_Op (N, Ctx_Type);
2318 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2320 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2321 N_Op_Divide | N_Op_Mod | N_Op_Rem
2323 => Resolve_Arithmetic_Op (N, Ctx_Type);
2325 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2327 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2329 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2330 => Resolve_Unary_Op (N, Ctx_Type);
2332 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2334 when N_Procedure_Call_Statement
2335 => Resolve_Call (N, Ctx_Type);
2337 when N_Operator_Symbol
2338 => Resolve_Operator_Symbol (N, Ctx_Type);
2340 when N_Qualified_Expression
2341 => Resolve_Qualified_Expression (N, Ctx_Type);
2343 when N_Raise_xxx_Error
2344 => Set_Etype (N, Ctx_Type);
2346 when N_Range => Resolve_Range (N, Ctx_Type);
2349 => Resolve_Real_Literal (N, Ctx_Type);
2351 when N_Reference => Resolve_Reference (N, Ctx_Type);
2353 when N_Selected_Component
2354 => Resolve_Selected_Component (N, Ctx_Type);
2356 when N_Slice => Resolve_Slice (N, Ctx_Type);
2358 when N_String_Literal
2359 => Resolve_String_Literal (N, Ctx_Type);
2361 when N_Subprogram_Info
2362 => Resolve_Subprogram_Info (N, Ctx_Type);
2364 when N_Type_Conversion
2365 => Resolve_Type_Conversion (N, Ctx_Type);
2367 when N_Unchecked_Expression =>
2368 Resolve_Unchecked_Expression (N, Ctx_Type);
2370 when N_Unchecked_Type_Conversion =>
2371 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2375 -- If the subexpression was replaced by a non-subexpression, then
2376 -- all we do is to expand it. The only legitimate case we know of
2377 -- is converting procedure call statement to entry call statements,
2378 -- but there may be others, so we are making this test general.
2380 if Nkind (N) not in N_Subexpr then
2381 Debug_A_Exit ("resolving ", N, " (done)");
2386 -- The expression is definitely NOT overloaded at this point, so
2387 -- we reset the Is_Overloaded flag to avoid any confusion when
2388 -- reanalyzing the node.
2390 Set_Is_Overloaded (N, False);
2392 -- Freeze expression type, entity if it is a name, and designated
2393 -- type if it is an allocator (RM 13.14(10,11,13)).
2395 -- Now that the resolution of the type of the node is complete,
2396 -- and we did not detect an error, we can expand this node. We
2397 -- skip the expand call if we are in a default expression, see
2398 -- section "Handling of Default Expressions" in Sem spec.
2400 Debug_A_Exit ("resolving ", N, " (done)");
2402 -- We unconditionally freeze the expression, even if we are in
2403 -- default expression mode (the Freeze_Expression routine tests
2404 -- this flag and only freezes static types if it is set).
2406 Freeze_Expression (N);
2408 -- Now we can do the expansion
2418 -- Version with check(s) suppressed
2420 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2422 if Suppress = All_Checks then
2424 Svg : constant Suppress_Array := Scope_Suppress;
2426 Scope_Suppress := (others => True);
2428 Scope_Suppress := Svg;
2433 Svg : constant Boolean := Scope_Suppress (Suppress);
2435 Scope_Suppress (Suppress) := True;
2437 Scope_Suppress (Suppress) := Svg;
2446 -- Version with implicit type
2448 procedure Resolve (N : Node_Id) is
2450 Resolve (N, Etype (N));
2453 ---------------------
2454 -- Resolve_Actuals --
2455 ---------------------
2457 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2458 Loc : constant Source_Ptr := Sloc (N);
2463 Prev : Node_Id := Empty;
2465 procedure Insert_Default;
2466 -- If the actual is missing in a call, insert in the actuals list
2467 -- an instance of the default expression. The insertion is always
2468 -- a named association.
2470 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2471 -- Check whether T1 and T2, or their full views, are derived from a
2472 -- common type. Used to enforce the restrictions on array conversions
2475 --------------------
2476 -- Insert_Default --
2477 --------------------
2479 procedure Insert_Default is
2484 -- Missing argument in call, nothing to insert
2486 if No (Default_Value (F)) then
2490 -- Note that we do a full New_Copy_Tree, so that any associated
2491 -- Itypes are properly copied. This may not be needed any more,
2492 -- but it does no harm as a safety measure! Defaults of a generic
2493 -- formal may be out of bounds of the corresponding actual (see
2494 -- cc1311b) and an additional check may be required.
2496 Actval := New_Copy_Tree (Default_Value (F),
2497 New_Scope => Current_Scope, New_Sloc => Loc);
2499 if Is_Concurrent_Type (Scope (Nam))
2500 and then Has_Discriminants (Scope (Nam))
2502 Replace_Actual_Discriminants (N, Actval);
2505 if Is_Overloadable (Nam)
2506 and then Present (Alias (Nam))
2508 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2509 and then not Is_Tagged_Type (Etype (F))
2511 -- If default is a real literal, do not introduce a
2512 -- conversion whose effect may depend on the run-time
2513 -- size of universal real.
2515 if Nkind (Actval) = N_Real_Literal then
2516 Set_Etype (Actval, Base_Type (Etype (F)));
2518 Actval := Unchecked_Convert_To (Etype (F), Actval);
2522 if Is_Scalar_Type (Etype (F)) then
2523 Enable_Range_Check (Actval);
2526 Set_Parent (Actval, N);
2528 -- Resolve aggregates with their base type, to avoid scope
2529 -- anomalies: the subtype was first built in the suprogram
2530 -- declaration, and the current call may be nested.
2532 if Nkind (Actval) = N_Aggregate
2533 and then Has_Discriminants (Etype (Actval))
2535 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2537 Analyze_And_Resolve (Actval, Etype (Actval));
2541 Set_Parent (Actval, N);
2543 -- See note above concerning aggregates
2545 if Nkind (Actval) = N_Aggregate
2546 and then Has_Discriminants (Etype (Actval))
2548 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2550 -- Resolve entities with their own type, which may differ
2551 -- from the type of a reference in a generic context (the
2552 -- view swapping mechanism did not anticipate the re-analysis
2553 -- of default values in calls).
2555 elsif Is_Entity_Name (Actval) then
2556 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2559 Analyze_And_Resolve (Actval, Etype (Actval));
2563 -- If default is a tag indeterminate function call, propagate
2564 -- tag to obtain proper dispatching.
2566 if Is_Controlling_Formal (F)
2567 and then Nkind (Default_Value (F)) = N_Function_Call
2569 Set_Is_Controlling_Actual (Actval);
2574 -- If the default expression raises constraint error, then just
2575 -- silently replace it with an N_Raise_Constraint_Error node,
2576 -- since we already gave the warning on the subprogram spec.
2578 if Raises_Constraint_Error (Actval) then
2580 Make_Raise_Constraint_Error (Loc,
2581 Reason => CE_Range_Check_Failed));
2582 Set_Raises_Constraint_Error (Actval);
2583 Set_Etype (Actval, Etype (F));
2587 Make_Parameter_Association (Loc,
2588 Explicit_Actual_Parameter => Actval,
2589 Selector_Name => Make_Identifier (Loc, Chars (F)));
2591 -- Case of insertion is first named actual
2593 if No (Prev) or else
2594 Nkind (Parent (Prev)) /= N_Parameter_Association
2596 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2597 Set_First_Named_Actual (N, Actval);
2600 if No (Parameter_Associations (N)) then
2601 Set_Parameter_Associations (N, New_List (Assoc));
2603 Append (Assoc, Parameter_Associations (N));
2607 Insert_After (Prev, Assoc);
2610 -- Case of insertion is not first named actual
2613 Set_Next_Named_Actual
2614 (Assoc, Next_Named_Actual (Parent (Prev)));
2615 Set_Next_Named_Actual (Parent (Prev), Actval);
2616 Append (Assoc, Parameter_Associations (N));
2619 Mark_Rewrite_Insertion (Assoc);
2620 Mark_Rewrite_Insertion (Actval);
2629 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2630 FT1 : Entity_Id := T1;
2631 FT2 : Entity_Id := T2;
2634 if Is_Private_Type (T1)
2635 and then Present (Full_View (T1))
2637 FT1 := Full_View (T1);
2640 if Is_Private_Type (T2)
2641 and then Present (Full_View (T2))
2643 FT2 := Full_View (T2);
2646 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
2649 -- Start of processing for Resolve_Actuals
2652 A := First_Actual (N);
2653 F := First_Formal (Nam);
2654 while Present (F) loop
2655 if No (A) and then Needs_No_Actuals (Nam) then
2658 -- If we have an error in any actual or formal, indicated by
2659 -- a type of Any_Type, then abandon resolution attempt, and
2660 -- set result type to Any_Type.
2662 elsif (Present (A) and then Etype (A) = Any_Type)
2663 or else Etype (F) = Any_Type
2665 Set_Etype (N, Any_Type);
2670 and then (Nkind (Parent (A)) /= N_Parameter_Association
2672 Chars (Selector_Name (Parent (A))) = Chars (F))
2674 -- If the formal is Out or In_Out, do not resolve and expand the
2675 -- conversion, because it is subsequently expanded into explicit
2676 -- temporaries and assignments. However, the object of the
2677 -- conversion can be resolved. An exception is the case of tagged
2678 -- type conversion with a class-wide actual. In that case we want
2679 -- the tag check to occur and no temporary will be needed (no
2680 -- representation change can occur) and the parameter is passed by
2681 -- reference, so we go ahead and resolve the type conversion.
2682 -- Another exception is the case of reference to component or
2683 -- subcomponent of a bit-packed array, in which case we want to
2684 -- defer expansion to the point the in and out assignments are
2687 if Ekind (F) /= E_In_Parameter
2688 and then Nkind (A) = N_Type_Conversion
2689 and then not Is_Class_Wide_Type (Etype (Expression (A)))
2691 if Ekind (F) = E_In_Out_Parameter
2692 and then Is_Array_Type (Etype (F))
2694 if Has_Aliased_Components (Etype (Expression (A)))
2695 /= Has_Aliased_Components (Etype (F))
2697 if Ada_Version < Ada_05 then
2699 ("both component types in a view conversion must be"
2700 & " aliased, or neither", A);
2702 -- Ada 2005: rule is relaxed (see AI-363)
2704 elsif Has_Aliased_Components (Etype (F))
2706 not Has_Aliased_Components (Etype (Expression (A)))
2709 ("view conversion operand must have aliased " &
2712 ("\since target type has aliased components", N);
2715 elsif not Same_Ancestor (Etype (F), Etype (Expression (A)))
2717 (Is_By_Reference_Type (Etype (F))
2718 or else Is_By_Reference_Type (Etype (Expression (A))))
2721 ("view conversion between unrelated by reference " &
2722 "array types not allowed (\'A'I-00246)", A);
2726 if (Conversion_OK (A)
2727 or else Valid_Conversion (A, Etype (A), Expression (A)))
2728 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
2730 Resolve (Expression (A));
2734 if Nkind (A) = N_Type_Conversion
2735 and then Is_Array_Type (Etype (F))
2736 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
2738 (Is_Limited_Type (Etype (F))
2739 or else Is_Limited_Type (Etype (Expression (A))))
2742 ("conversion between unrelated limited array types " &
2743 "not allowed (\A\I-00246)", A);
2745 if Is_Limited_Type (Etype (F)) then
2746 Explain_Limited_Type (Etype (F), A);
2749 if Is_Limited_Type (Etype (Expression (A))) then
2750 Explain_Limited_Type (Etype (Expression (A)), A);
2754 -- (Ada 2005: AI-251): If the actual is an allocator whose
2755 -- directly designated type is a class-wide interface, we build
2756 -- an anonymous access type to use it as the type of the
2757 -- allocator. Later, when the subprogram call is expanded, if
2758 -- the interface has a secondary dispatch table the expander
2759 -- will add a type conversion to force the correct displacement
2762 if Nkind (A) = N_Allocator then
2764 DDT : constant Entity_Id :=
2765 Directly_Designated_Type (Base_Type (Etype (F)));
2766 New_Itype : Entity_Id;
2768 if Is_Class_Wide_Type (DDT)
2769 and then Is_Interface (DDT)
2771 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
2772 Set_Etype (New_Itype, Etype (A));
2773 Init_Size_Align (New_Itype);
2774 Set_Directly_Designated_Type (New_Itype,
2775 Directly_Designated_Type (Etype (A)));
2776 Set_Etype (A, New_Itype);
2779 -- Ada 2005, AI-162:If the actual is an allocator, the
2780 -- innermost enclosing statement is the master of the
2783 if Is_Controlled (DDT)
2784 or else Has_Task (DDT)
2786 Establish_Transient_Scope (A, False);
2791 Resolve (A, Etype (F));
2797 -- Perform error checks for IN and IN OUT parameters
2799 if Ekind (F) /= E_Out_Parameter then
2801 -- Check unset reference. For scalar parameters, it is clearly
2802 -- wrong to pass an uninitialized value as either an IN or
2803 -- IN-OUT parameter. For composites, it is also clearly an
2804 -- error to pass a completely uninitialized value as an IN
2805 -- parameter, but the case of IN OUT is trickier. We prefer
2806 -- not to give a warning here. For example, suppose there is
2807 -- a routine that sets some component of a record to False.
2808 -- It is perfectly reasonable to make this IN-OUT and allow
2809 -- either initialized or uninitialized records to be passed
2812 -- For partially initialized composite values, we also avoid
2813 -- warnings, since it is quite likely that we are passing a
2814 -- partially initialized value and only the initialized fields
2815 -- will in fact be read in the subprogram.
2817 if Is_Scalar_Type (A_Typ)
2818 or else (Ekind (F) = E_In_Parameter
2819 and then not Is_Partially_Initialized_Type (A_Typ))
2821 Check_Unset_Reference (A);
2824 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
2825 -- actual to a nested call, since this is case of reading an
2826 -- out parameter, which is not allowed.
2828 if Ada_Version = Ada_83
2829 and then Is_Entity_Name (A)
2830 and then Ekind (Entity (A)) = E_Out_Parameter
2832 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
2836 if Ekind (F) /= E_In_Parameter
2837 and then not Is_OK_Variable_For_Out_Formal (A)
2839 Error_Msg_NE ("actual for& must be a variable", A, F);
2841 if Is_Entity_Name (A) then
2842 Kill_Checks (Entity (A));
2848 if Etype (A) = Any_Type then
2849 Set_Etype (N, Any_Type);
2853 -- Apply appropriate range checks for in, out, and in-out
2854 -- parameters. Out and in-out parameters also need a separate
2855 -- check, if there is a type conversion, to make sure the return
2856 -- value meets the constraints of the variable before the
2859 -- Gigi looks at the check flag and uses the appropriate types.
2860 -- For now since one flag is used there is an optimization which
2861 -- might not be done in the In Out case since Gigi does not do
2862 -- any analysis. More thought required about this ???
2864 if Ekind (F) = E_In_Parameter
2865 or else Ekind (F) = E_In_Out_Parameter
2867 if Is_Scalar_Type (Etype (A)) then
2868 Apply_Scalar_Range_Check (A, F_Typ);
2870 elsif Is_Array_Type (Etype (A)) then
2871 Apply_Length_Check (A, F_Typ);
2873 elsif Is_Record_Type (F_Typ)
2874 and then Has_Discriminants (F_Typ)
2875 and then Is_Constrained (F_Typ)
2876 and then (not Is_Derived_Type (F_Typ)
2877 or else Comes_From_Source (Nam))
2879 Apply_Discriminant_Check (A, F_Typ);
2881 elsif Is_Access_Type (F_Typ)
2882 and then Is_Array_Type (Designated_Type (F_Typ))
2883 and then Is_Constrained (Designated_Type (F_Typ))
2885 Apply_Length_Check (A, F_Typ);
2887 elsif Is_Access_Type (F_Typ)
2888 and then Has_Discriminants (Designated_Type (F_Typ))
2889 and then Is_Constrained (Designated_Type (F_Typ))
2891 Apply_Discriminant_Check (A, F_Typ);
2894 Apply_Range_Check (A, F_Typ);
2897 -- Ada 2005 (AI-231)
2899 if Ada_Version >= Ada_05
2900 and then Is_Access_Type (F_Typ)
2901 and then Can_Never_Be_Null (F_Typ)
2902 and then Nkind (A) = N_Null
2904 Apply_Compile_Time_Constraint_Error
2906 Msg => "(Ada 2005) NULL not allowed in "
2907 & "null-excluding formal?",
2908 Reason => CE_Null_Not_Allowed);
2912 if Ekind (F) = E_Out_Parameter
2913 or else Ekind (F) = E_In_Out_Parameter
2915 if Nkind (A) = N_Type_Conversion then
2916 if Is_Scalar_Type (A_Typ) then
2917 Apply_Scalar_Range_Check
2918 (Expression (A), Etype (Expression (A)), A_Typ);
2921 (Expression (A), Etype (Expression (A)), A_Typ);
2925 if Is_Scalar_Type (F_Typ) then
2926 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
2928 elsif Is_Array_Type (F_Typ)
2929 and then Ekind (F) = E_Out_Parameter
2931 Apply_Length_Check (A, F_Typ);
2934 Apply_Range_Check (A, A_Typ, F_Typ);
2939 -- An actual associated with an access parameter is implicitly
2940 -- converted to the anonymous access type of the formal and
2941 -- must satisfy the legality checks for access conversions.
2943 if Ekind (F_Typ) = E_Anonymous_Access_Type then
2944 if not Valid_Conversion (A, F_Typ, A) then
2946 ("invalid implicit conversion for access parameter", A);
2950 -- Check bad case of atomic/volatile argument (RM C.6(12))
2952 if Is_By_Reference_Type (Etype (F))
2953 and then Comes_From_Source (N)
2955 if Is_Atomic_Object (A)
2956 and then not Is_Atomic (Etype (F))
2959 ("cannot pass atomic argument to non-atomic formal",
2962 elsif Is_Volatile_Object (A)
2963 and then not Is_Volatile (Etype (F))
2966 ("cannot pass volatile argument to non-volatile formal",
2971 -- Check that subprograms don't have improper controlling
2972 -- arguments (RM 3.9.2 (9))
2974 -- A primitive operation may have an access parameter of an
2975 -- incomplete tagged type, but a dispatching call is illegal
2976 -- if the type is still incomplete.
2978 if Is_Controlling_Formal (F) then
2979 Set_Is_Controlling_Actual (A);
2981 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
2983 Desig : constant Entity_Id := Designated_Type (Etype (F));
2985 if Ekind (Desig) = E_Incomplete_Type
2986 and then No (Full_View (Desig))
2987 and then No (Non_Limited_View (Desig))
2990 ("premature use of incomplete type& " &
2991 "in dispatching call", A, Desig);
2996 elsif Nkind (A) = N_Explicit_Dereference then
2997 Validate_Remote_Access_To_Class_Wide_Type (A);
3000 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3001 and then not Is_Class_Wide_Type (F_Typ)
3002 and then not Is_Controlling_Formal (F)
3004 Error_Msg_N ("class-wide argument not allowed here!", A);
3006 if Is_Subprogram (Nam)
3007 and then Comes_From_Source (Nam)
3009 Error_Msg_Node_2 := F_Typ;
3011 ("& is not a dispatching operation of &!", A, Nam);
3014 elsif Is_Access_Type (A_Typ)
3015 and then Is_Access_Type (F_Typ)
3016 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3017 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3018 or else (Nkind (A) = N_Attribute_Reference
3020 Is_Class_Wide_Type (Etype (Prefix (A)))))
3021 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3022 and then not Is_Controlling_Formal (F)
3025 ("access to class-wide argument not allowed here!", A);
3027 if Is_Subprogram (Nam)
3028 and then Comes_From_Source (Nam)
3030 Error_Msg_Node_2 := Designated_Type (F_Typ);
3032 ("& is not a dispatching operation of &!", A, Nam);
3038 -- If it is a named association, treat the selector_name as
3039 -- a proper identifier, and mark the corresponding entity.
3041 if Nkind (Parent (A)) = N_Parameter_Association then
3042 Set_Entity (Selector_Name (Parent (A)), F);
3043 Generate_Reference (F, Selector_Name (Parent (A)));
3044 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3045 Generate_Reference (F_Typ, N, ' ');
3050 if Ekind (F) /= E_Out_Parameter then
3051 Check_Unset_Reference (A);
3056 -- Case where actual is not present
3064 end Resolve_Actuals;
3066 -----------------------
3067 -- Resolve_Allocator --
3068 -----------------------
3070 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3071 E : constant Node_Id := Expression (N);
3073 Discrim : Entity_Id;
3077 function In_Dispatching_Context return Boolean;
3078 -- If the allocator is an actual in a call, it is allowed to be
3079 -- class-wide when the context is not because it is a controlling
3082 ----------------------------
3083 -- In_Dispatching_Context --
3084 ----------------------------
3086 function In_Dispatching_Context return Boolean is
3087 Par : constant Node_Id := Parent (N);
3090 return (Nkind (Par) = N_Function_Call
3091 or else Nkind (Par) = N_Procedure_Call_Statement)
3092 and then Is_Entity_Name (Name (Par))
3093 and then Is_Dispatching_Operation (Entity (Name (Par)));
3094 end In_Dispatching_Context;
3096 -- Start of processing for Resolve_Allocator
3099 -- Replace general access with specific type
3101 if Ekind (Etype (N)) = E_Allocator_Type then
3102 Set_Etype (N, Base_Type (Typ));
3105 if Is_Abstract_Type (Typ) then
3106 Error_Msg_N ("type of allocator cannot be abstract", N);
3109 -- For qualified expression, resolve the expression using the
3110 -- given subtype (nothing to do for type mark, subtype indication)
3112 if Nkind (E) = N_Qualified_Expression then
3113 if Is_Class_Wide_Type (Etype (E))
3114 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3115 and then not In_Dispatching_Context
3118 ("class-wide allocator not allowed for this access type", N);
3121 Resolve (Expression (E), Etype (E));
3122 Check_Unset_Reference (Expression (E));
3124 -- A qualified expression requires an exact match of the type,
3125 -- class-wide matching is not allowed.
3127 if (Is_Class_Wide_Type (Etype (Expression (E)))
3128 or else Is_Class_Wide_Type (Etype (E)))
3129 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3131 Wrong_Type (Expression (E), Etype (E));
3134 -- For a subtype mark or subtype indication, freeze the subtype
3137 Freeze_Expression (E);
3139 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
3141 ("initialization required for access-to-constant allocator", N);
3144 -- A special accessibility check is needed for allocators that
3145 -- constrain access discriminants. The level of the type of the
3146 -- expression used to contrain an access discriminant cannot be
3147 -- deeper than the type of the allocator (in constrast to access
3148 -- parameters, where the level of the actual can be arbitrary).
3149 -- We can't use Valid_Conversion to perform this check because
3150 -- in general the type of the allocator is unrelated to the type
3151 -- of the access discriminant. Note that specialized checks are
3152 -- needed for the cases of a constraint expression which is an
3153 -- access attribute or an access discriminant.
3155 if Nkind (Original_Node (E)) = N_Subtype_Indication
3156 and then Ekind (Typ) /= E_Anonymous_Access_Type
3158 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
3160 if Has_Discriminants (Subtyp) then
3161 Discrim := First_Discriminant (Base_Type (Subtyp));
3162 Constr := First (Constraints (Constraint (Original_Node (E))));
3163 while Present (Discrim) and then Present (Constr) loop
3164 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
3165 if Nkind (Constr) = N_Discriminant_Association then
3166 Disc_Exp := Original_Node (Expression (Constr));
3168 Disc_Exp := Original_Node (Constr);
3171 if Type_Access_Level (Etype (Disc_Exp))
3172 > Type_Access_Level (Typ)
3175 ("operand type has deeper level than allocator type",
3178 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3179 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3181 and then Object_Access_Level (Prefix (Disc_Exp))
3182 > Type_Access_Level (Typ)
3185 ("prefix of attribute has deeper level than"
3186 & " allocator type", Disc_Exp);
3188 -- When the operand is an access discriminant the check
3189 -- is against the level of the prefix object.
3191 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3192 and then Nkind (Disc_Exp) = N_Selected_Component
3193 and then Object_Access_Level (Prefix (Disc_Exp))
3194 > Type_Access_Level (Typ)
3197 ("access discriminant has deeper level than"
3198 & " allocator type", Disc_Exp);
3201 Next_Discriminant (Discrim);
3208 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
3209 -- check that the level of the type of the created object is not deeper
3210 -- than the level of the allocator's access type, since extensions can
3211 -- now occur at deeper levels than their ancestor types. This is a
3212 -- static accessibility level check; a run-time check is also needed in
3213 -- the case of an initialized allocator with a class-wide argument (see
3214 -- Expand_Allocator_Expression).
3216 if Ada_Version >= Ada_05
3217 and then Is_Class_Wide_Type (Designated_Type (Typ))
3220 Exp_Typ : Entity_Id;
3223 if Nkind (E) = N_Qualified_Expression then
3224 Exp_Typ := Etype (E);
3225 elsif Nkind (E) = N_Subtype_Indication then
3226 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
3228 Exp_Typ := Entity (E);
3231 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
3232 if In_Instance_Body then
3233 Error_Msg_N ("?type in allocator has deeper level than" &
3234 " designated class-wide type", E);
3235 Error_Msg_N ("\?Program_Error will be raised at run time",
3238 Make_Raise_Program_Error (Sloc (N),
3239 Reason => PE_Accessibility_Check_Failed));
3242 -- Do not apply Ada 2005 accessibility checks on a class-wide
3243 -- allocator if the type given in the allocator is a formal
3244 -- type. A run-time check will be performed in the instance.
3246 elsif not Is_Generic_Type (Exp_Typ) then
3247 Error_Msg_N ("type in allocator has deeper level than" &
3248 " designated class-wide type", E);
3254 -- Check for allocation from an empty storage pool
3256 if No_Pool_Assigned (Typ) then
3258 Loc : constant Source_Ptr := Sloc (N);
3260 Error_Msg_N ("?allocation from empty storage pool", N);
3261 Error_Msg_N ("\?Storage_Error will be raised at run time", N);
3263 Make_Raise_Storage_Error (Loc,
3264 Reason => SE_Empty_Storage_Pool));
3267 -- If the context is an unchecked conversion, as may happen within
3268 -- an inlined subprogram, the allocator is being resolved with its
3269 -- own anonymous type. In that case, if the target type has a specific
3270 -- storage pool, it must be inherited explicitly by the allocator type.
3272 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
3273 and then No (Associated_Storage_Pool (Typ))
3275 Set_Associated_Storage_Pool
3276 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
3278 end Resolve_Allocator;
3280 ---------------------------
3281 -- Resolve_Arithmetic_Op --
3282 ---------------------------
3284 -- Used for resolving all arithmetic operators except exponentiation
3286 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
3287 L : constant Node_Id := Left_Opnd (N);
3288 R : constant Node_Id := Right_Opnd (N);
3289 TL : constant Entity_Id := Base_Type (Etype (L));
3290 TR : constant Entity_Id := Base_Type (Etype (R));
3294 B_Typ : constant Entity_Id := Base_Type (Typ);
3295 -- We do the resolution using the base type, because intermediate values
3296 -- in expressions always are of the base type, not a subtype of it.
3298 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
3299 -- Returns True if N is in a context that expects "any real type"
3301 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
3302 -- Return True iff given type is Integer or universal real/integer
3304 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
3305 -- Choose type of integer literal in fixed-point operation to conform
3306 -- to available fixed-point type. T is the type of the other operand,
3307 -- which is needed to determine the expected type of N.
3309 procedure Set_Operand_Type (N : Node_Id);
3310 -- Set operand type to T if universal
3312 -------------------------------
3313 -- Expected_Type_Is_Any_Real --
3314 -------------------------------
3316 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
3318 -- N is the expression after "delta" in a fixed_point_definition;
3321 return Nkind (Parent (N)) = N_Ordinary_Fixed_Point_Definition
3322 or else Nkind (Parent (N)) = N_Decimal_Fixed_Point_Definition
3324 -- N is one of the bounds in a real_range_specification;
3327 or else Nkind (Parent (N)) = N_Real_Range_Specification
3329 -- N is the expression of a delta_constraint;
3332 or else Nkind (Parent (N)) = N_Delta_Constraint;
3333 end Expected_Type_Is_Any_Real;
3335 -----------------------------
3336 -- Is_Integer_Or_Universal --
3337 -----------------------------
3339 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
3341 Index : Interp_Index;
3345 if not Is_Overloaded (N) then
3347 return Base_Type (T) = Base_Type (Standard_Integer)
3348 or else T = Universal_Integer
3349 or else T = Universal_Real;
3351 Get_First_Interp (N, Index, It);
3352 while Present (It.Typ) loop
3353 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
3354 or else It.Typ = Universal_Integer
3355 or else It.Typ = Universal_Real
3360 Get_Next_Interp (Index, It);
3365 end Is_Integer_Or_Universal;
3367 ----------------------------
3368 -- Set_Mixed_Mode_Operand --
3369 ----------------------------
3371 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
3372 Index : Interp_Index;
3376 if Universal_Interpretation (N) = Universal_Integer then
3378 -- A universal integer literal is resolved as standard integer
3379 -- except in the case of a fixed-point result, where we leave it
3380 -- as universal (to be handled by Exp_Fixd later on)
3382 if Is_Fixed_Point_Type (T) then
3383 Resolve (N, Universal_Integer);
3385 Resolve (N, Standard_Integer);
3388 elsif Universal_Interpretation (N) = Universal_Real
3389 and then (T = Base_Type (Standard_Integer)
3390 or else T = Universal_Integer
3391 or else T = Universal_Real)
3393 -- A universal real can appear in a fixed-type context. We resolve
3394 -- the literal with that context, even though this might raise an
3395 -- exception prematurely (the other operand may be zero).
3399 elsif Etype (N) = Base_Type (Standard_Integer)
3400 and then T = Universal_Real
3401 and then Is_Overloaded (N)
3403 -- Integer arg in mixed-mode operation. Resolve with universal
3404 -- type, in case preference rule must be applied.
3406 Resolve (N, Universal_Integer);
3409 and then B_Typ /= Universal_Fixed
3411 -- Not a mixed-mode operation, resolve with context
3415 elsif Etype (N) = Any_Fixed then
3417 -- N may itself be a mixed-mode operation, so use context type
3421 elsif Is_Fixed_Point_Type (T)
3422 and then B_Typ = Universal_Fixed
3423 and then Is_Overloaded (N)
3425 -- Must be (fixed * fixed) operation, operand must have one
3426 -- compatible interpretation.
3428 Resolve (N, Any_Fixed);
3430 elsif Is_Fixed_Point_Type (B_Typ)
3431 and then (T = Universal_Real
3432 or else Is_Fixed_Point_Type (T))
3433 and then Is_Overloaded (N)
3435 -- C * F(X) in a fixed context, where C is a real literal or a
3436 -- fixed-point expression. F must have either a fixed type
3437 -- interpretation or an integer interpretation, but not both.
3439 Get_First_Interp (N, Index, It);
3440 while Present (It.Typ) loop
3441 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
3443 if Analyzed (N) then
3444 Error_Msg_N ("ambiguous operand in fixed operation", N);
3446 Resolve (N, Standard_Integer);
3449 elsif Is_Fixed_Point_Type (It.Typ) then
3451 if Analyzed (N) then
3452 Error_Msg_N ("ambiguous operand in fixed operation", N);
3454 Resolve (N, It.Typ);
3458 Get_Next_Interp (Index, It);
3461 -- Reanalyze the literal with the fixed type of the context. If
3462 -- context is Universal_Fixed, we are within a conversion, leave
3463 -- the literal as a universal real because there is no usable
3464 -- fixed type, and the target of the conversion plays no role in
3478 if B_Typ = Universal_Fixed
3479 and then Nkind (Op2) = N_Real_Literal
3481 T2 := Universal_Real;
3486 Set_Analyzed (Op2, False);
3493 end Set_Mixed_Mode_Operand;
3495 ----------------------
3496 -- Set_Operand_Type --
3497 ----------------------
3499 procedure Set_Operand_Type (N : Node_Id) is
3501 if Etype (N) = Universal_Integer
3502 or else Etype (N) = Universal_Real
3506 end Set_Operand_Type;
3508 -- Start of processing for Resolve_Arithmetic_Op
3511 if Comes_From_Source (N)
3512 and then Ekind (Entity (N)) = E_Function
3513 and then Is_Imported (Entity (N))
3514 and then Is_Intrinsic_Subprogram (Entity (N))
3516 Resolve_Intrinsic_Operator (N, Typ);
3519 -- Special-case for mixed-mode universal expressions or fixed point
3520 -- type operation: each argument is resolved separately. The same
3521 -- treatment is required if one of the operands of a fixed point
3522 -- operation is universal real, since in this case we don't do a
3523 -- conversion to a specific fixed-point type (instead the expander
3524 -- takes care of the case).
3526 elsif (B_Typ = Universal_Integer
3527 or else B_Typ = Universal_Real)
3528 and then Present (Universal_Interpretation (L))
3529 and then Present (Universal_Interpretation (R))
3531 Resolve (L, Universal_Interpretation (L));
3532 Resolve (R, Universal_Interpretation (R));
3533 Set_Etype (N, B_Typ);
3535 elsif (B_Typ = Universal_Real
3536 or else Etype (N) = Universal_Fixed
3537 or else (Etype (N) = Any_Fixed
3538 and then Is_Fixed_Point_Type (B_Typ))
3539 or else (Is_Fixed_Point_Type (B_Typ)
3540 and then (Is_Integer_Or_Universal (L)
3542 Is_Integer_Or_Universal (R))))
3543 and then (Nkind (N) = N_Op_Multiply or else
3544 Nkind (N) = N_Op_Divide)
3546 if TL = Universal_Integer or else TR = Universal_Integer then
3547 Check_For_Visible_Operator (N, B_Typ);
3550 -- If context is a fixed type and one operand is integer, the
3551 -- other is resolved with the type of the context.
3553 if Is_Fixed_Point_Type (B_Typ)
3554 and then (Base_Type (TL) = Base_Type (Standard_Integer)
3555 or else TL = Universal_Integer)
3560 elsif Is_Fixed_Point_Type (B_Typ)
3561 and then (Base_Type (TR) = Base_Type (Standard_Integer)
3562 or else TR = Universal_Integer)
3568 Set_Mixed_Mode_Operand (L, TR);
3569 Set_Mixed_Mode_Operand (R, TL);
3572 -- Check the rule in RM05-4.5.5(19.1/2) disallowing the
3573 -- universal_fixed multiplying operators from being used when the
3574 -- expected type is also universal_fixed. Note that B_Typ will be
3575 -- Universal_Fixed in some cases where the expected type is actually
3576 -- Any_Real; Expected_Type_Is_Any_Real takes care of that case.
3578 if Etype (N) = Universal_Fixed
3579 or else Etype (N) = Any_Fixed
3581 if B_Typ = Universal_Fixed
3582 and then not Expected_Type_Is_Any_Real (N)
3583 and then Nkind (Parent (N)) /= N_Type_Conversion
3584 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3587 ("type cannot be determined from context!", N);
3589 ("\explicit conversion to result type required", N);
3591 Set_Etype (L, Any_Type);
3592 Set_Etype (R, Any_Type);
3595 if Ada_Version = Ada_83
3596 and then Etype (N) = Universal_Fixed
3597 and then Nkind (Parent (N)) /= N_Type_Conversion
3598 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3601 ("(Ada 83) fixed-point operation " &
3602 "needs explicit conversion",
3606 -- The expected type is "any real type" in contexts like
3607 -- type T is delta <universal_fixed-expression> ...
3608 -- in which case we need to set the type to Universal_Real
3609 -- so that static expression evaluation will work properly.
3611 if Expected_Type_Is_Any_Real (N) then
3612 Set_Etype (N, Universal_Real);
3614 Set_Etype (N, B_Typ);
3618 elsif Is_Fixed_Point_Type (B_Typ)
3619 and then (Is_Integer_Or_Universal (L)
3620 or else Nkind (L) = N_Real_Literal
3621 or else Nkind (R) = N_Real_Literal
3623 Is_Integer_Or_Universal (R))
3625 Set_Etype (N, B_Typ);
3627 elsif Etype (N) = Any_Fixed then
3629 -- If no previous errors, this is only possible if one operand
3630 -- is overloaded and the context is universal. Resolve as such.
3632 Set_Etype (N, B_Typ);
3636 if (TL = Universal_Integer or else TL = Universal_Real)
3637 and then (TR = Universal_Integer or else TR = Universal_Real)
3639 Check_For_Visible_Operator (N, B_Typ);
3642 -- If the context is Universal_Fixed and the operands are also
3643 -- universal fixed, this is an error, unless there is only one
3644 -- applicable fixed_point type (usually duration).
3646 if B_Typ = Universal_Fixed
3647 and then Etype (L) = Universal_Fixed
3649 T := Unique_Fixed_Point_Type (N);
3651 if T = Any_Type then
3664 -- If one of the arguments was resolved to a non-universal type.
3665 -- label the result of the operation itself with the same type.
3666 -- Do the same for the universal argument, if any.
3668 T := Intersect_Types (L, R);
3669 Set_Etype (N, Base_Type (T));
3670 Set_Operand_Type (L);
3671 Set_Operand_Type (R);
3674 Generate_Operator_Reference (N, Typ);
3675 Eval_Arithmetic_Op (N);
3677 -- Set overflow and division checking bit. Much cleverer code needed
3678 -- here eventually and perhaps the Resolve routines should be separated
3679 -- for the various arithmetic operations, since they will need
3680 -- different processing. ???
3682 if Nkind (N) in N_Op then
3683 if not Overflow_Checks_Suppressed (Etype (N)) then
3684 Enable_Overflow_Check (N);
3687 -- Give warning if explicit division by zero
3689 if (Nkind (N) = N_Op_Divide
3690 or else Nkind (N) = N_Op_Rem
3691 or else Nkind (N) = N_Op_Mod)
3692 and then not Division_Checks_Suppressed (Etype (N))
3694 Rop := Right_Opnd (N);
3696 if Compile_Time_Known_Value (Rop)
3697 and then ((Is_Integer_Type (Etype (Rop))
3698 and then Expr_Value (Rop) = Uint_0)
3700 (Is_Real_Type (Etype (Rop))
3701 and then Expr_Value_R (Rop) = Ureal_0))
3703 -- Specialize the warning message according to the operation
3707 Apply_Compile_Time_Constraint_Error
3708 (N, "division by zero?", CE_Divide_By_Zero,
3709 Loc => Sloc (Right_Opnd (N)));
3712 Apply_Compile_Time_Constraint_Error
3713 (N, "rem with zero divisor?", CE_Divide_By_Zero,
3714 Loc => Sloc (Right_Opnd (N)));
3717 Apply_Compile_Time_Constraint_Error
3718 (N, "mod with zero divisor?", CE_Divide_By_Zero,
3719 Loc => Sloc (Right_Opnd (N)));
3721 -- Division by zero can only happen with division, rem,
3722 -- and mod operations.
3725 raise Program_Error;
3728 -- Otherwise just set the flag to check at run time
3731 Set_Do_Division_Check (N);
3736 Check_Unset_Reference (L);
3737 Check_Unset_Reference (R);
3738 end Resolve_Arithmetic_Op;
3744 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
3745 Loc : constant Source_Ptr := Sloc (N);
3746 Subp : constant Node_Id := Name (N);
3755 -- The context imposes a unique interpretation with type Typ on a
3756 -- procedure or function call. Find the entity of the subprogram that
3757 -- yields the expected type, and propagate the corresponding formal
3758 -- constraints on the actuals. The caller has established that an
3759 -- interpretation exists, and emitted an error if not unique.
3761 -- First deal with the case of a call to an access-to-subprogram,
3762 -- dereference made explicit in Analyze_Call.
3764 if Ekind (Etype (Subp)) = E_Subprogram_Type then
3765 if not Is_Overloaded (Subp) then
3766 Nam := Etype (Subp);
3769 -- Find the interpretation whose type (a subprogram type) has a
3770 -- return type that is compatible with the context. Analysis of
3771 -- the node has established that one exists.
3775 Get_First_Interp (Subp, I, It);
3776 while Present (It.Typ) loop
3777 if Covers (Typ, Etype (It.Typ)) then
3782 Get_Next_Interp (I, It);
3786 raise Program_Error;
3790 -- If the prefix is not an entity, then resolve it
3792 if not Is_Entity_Name (Subp) then
3793 Resolve (Subp, Nam);
3796 -- For an indirect call, we always invalidate checks, since we do not
3797 -- know whether the subprogram is local or global. Yes we could do
3798 -- better here, e.g. by knowing that there are no local subprograms,
3799 -- but it does not seem worth the effort. Similarly, we kill all
3800 -- knowledge of current constant values.
3802 Kill_Current_Values;
3804 -- If this is a procedure call which is really an entry call, do the
3805 -- conversion of the procedure call to an entry call. Protected
3806 -- operations use the same circuitry because the name in the call can be
3807 -- an arbitrary expression with special resolution rules.
3809 elsif Nkind (Subp) = N_Selected_Component
3810 or else Nkind (Subp) = N_Indexed_Component
3811 or else (Is_Entity_Name (Subp)
3812 and then Ekind (Entity (Subp)) = E_Entry)
3814 Resolve_Entry_Call (N, Typ);
3815 Check_Elab_Call (N);
3817 -- Kill checks and constant values, as above for indirect case
3818 -- Who knows what happens when another task is activated?
3820 Kill_Current_Values;
3823 -- Normal subprogram call with name established in Resolve
3825 elsif not (Is_Type (Entity (Subp))) then
3826 Nam := Entity (Subp);
3827 Set_Entity_With_Style_Check (Subp, Nam);
3828 Generate_Reference (Nam, Subp);
3830 -- Otherwise we must have the case of an overloaded call
3833 pragma Assert (Is_Overloaded (Subp));
3834 Nam := Empty; -- We know that it will be assigned in loop below
3836 Get_First_Interp (Subp, I, It);
3837 while Present (It.Typ) loop
3838 if Covers (Typ, It.Typ) then
3840 Set_Entity_With_Style_Check (Subp, Nam);
3841 Generate_Reference (Nam, Subp);
3845 Get_Next_Interp (I, It);
3849 -- Check that a call to Current_Task does not occur in an entry body
3851 if Is_RTE (Nam, RE_Current_Task) then
3861 if Nkind (P) = N_Entry_Body
3862 or else (Nkind (P) = N_Subprogram_Body
3863 and then Is_Entry_Barrier_Function (P))
3867 ("& should not be used in entry body ('R'M C.7(17))?",
3870 ("\Program_Error will be raised at run time?", N, Nam);
3872 Make_Raise_Program_Error (Loc,
3873 Reason => PE_Current_Task_In_Entry_Body));
3874 Set_Etype (N, Rtype);
3881 -- Cannot call thread body directly
3883 if Is_Thread_Body (Nam) then
3884 Error_Msg_N ("cannot call thread body directly", N);
3887 -- Check that a procedure call does not occur in the context of the
3888 -- entry call statement of a conditional or timed entry call. Note that
3889 -- the case of a call to a subprogram renaming of an entry will also be
3890 -- rejected. The test for N not being an N_Entry_Call_Statement is
3891 -- defensive, covering the possibility that the processing of entry
3892 -- calls might reach this point due to later modifications of the code
3895 if Nkind (Parent (N)) = N_Entry_Call_Alternative
3896 and then Nkind (N) /= N_Entry_Call_Statement
3897 and then Entry_Call_Statement (Parent (N)) = N
3899 if Ada_Version < Ada_05 then
3900 Error_Msg_N ("entry call required in select statement", N);
3902 -- Ada 2005 (AI-345): If a procedure_call_statement is used
3903 -- for a procedure_or_entry_call, the procedure_name or pro-
3904 -- cedure_prefix of the procedure_call_statement shall denote
3905 -- an entry renamed by a procedure, or (a view of) a primitive
3906 -- subprogram of a limited interface whose first parameter is
3907 -- a controlling parameter.
3909 elsif Nkind (N) = N_Procedure_Call_Statement
3910 and then not Is_Renamed_Entry (Nam)
3911 and then not Is_Controlling_Limited_Procedure (Nam)
3914 ("entry call or dispatching primitive of interface required", N);
3918 -- Check that this is not a call to a protected procedure or
3919 -- entry from within a protected function.
3921 if Ekind (Current_Scope) = E_Function
3922 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
3923 and then Ekind (Nam) /= E_Function
3924 and then Scope (Nam) = Scope (Current_Scope)
3926 Error_Msg_N ("within protected function, protected " &
3927 "object is constant", N);
3928 Error_Msg_N ("\cannot call operation that may modify it", N);
3931 -- Freeze the subprogram name if not in default expression. Note that we
3932 -- freeze procedure calls as well as function calls. Procedure calls are
3933 -- not frozen according to the rules (RM 13.14(14)) because it is
3934 -- impossible to have a procedure call to a non-frozen procedure in pure
3935 -- Ada, but in the code that we generate in the expander, this rule
3936 -- needs extending because we can generate procedure calls that need
3939 if Is_Entity_Name (Subp) and then not In_Default_Expression then
3940 Freeze_Expression (Subp);
3943 -- For a predefined operator, the type of the result is the type imposed
3944 -- by context, except for a predefined operation on universal fixed.
3945 -- Otherwise The type of the call is the type returned by the subprogram
3948 if Is_Predefined_Op (Nam) then
3949 if Etype (N) /= Universal_Fixed then
3953 -- If the subprogram returns an array type, and the context requires the
3954 -- component type of that array type, the node is really an indexing of
3955 -- the parameterless call. Resolve as such. A pathological case occurs
3956 -- when the type of the component is an access to the array type. In
3957 -- this case the call is truly ambiguous.
3959 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
3961 ((Is_Array_Type (Etype (Nam))
3962 and then Covers (Typ, Component_Type (Etype (Nam))))
3963 or else (Is_Access_Type (Etype (Nam))
3964 and then Is_Array_Type (Designated_Type (Etype (Nam)))
3967 Component_Type (Designated_Type (Etype (Nam))))))
3970 Index_Node : Node_Id;
3972 Ret_Type : constant Entity_Id := Etype (Nam);
3975 if Is_Access_Type (Ret_Type)
3976 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
3979 ("cannot disambiguate function call and indexing", N);
3981 New_Subp := Relocate_Node (Subp);
3982 Set_Entity (Subp, Nam);
3984 if Component_Type (Ret_Type) /= Any_Type then
3985 if Needs_No_Actuals (Nam) then
3987 -- Indexed call to a parameterless function
3990 Make_Indexed_Component (Loc,
3992 Make_Function_Call (Loc,
3994 Expressions => Parameter_Associations (N));
3996 -- An Ada 2005 prefixed call to a primitive operation
3997 -- whose first parameter is the prefix. This prefix was
3998 -- prepended to the parameter list, which is actually a
3999 -- list of indices. Remove the prefix in order to build
4000 -- the proper indexed component.
4003 Make_Indexed_Component (Loc,
4005 Make_Function_Call (Loc,
4007 Parameter_Associations =>
4009 (Remove_Head (Parameter_Associations (N)))),
4010 Expressions => Parameter_Associations (N));
4013 -- Since we are correcting a node classification error made
4014 -- by the parser, we call Replace rather than Rewrite.
4016 Replace (N, Index_Node);
4017 Set_Etype (Prefix (N), Ret_Type);
4019 Resolve_Indexed_Component (N, Typ);
4020 Check_Elab_Call (Prefix (N));
4028 Set_Etype (N, Etype (Nam));
4031 -- In the case where the call is to an overloaded subprogram, Analyze
4032 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
4033 -- such a case Normalize_Actuals needs to be called once more to order
4034 -- the actuals correctly. Otherwise the call will have the ordering
4035 -- given by the last overloaded subprogram whether this is the correct
4036 -- one being called or not.
4038 if Is_Overloaded (Subp) then
4039 Normalize_Actuals (N, Nam, False, Norm_OK);
4040 pragma Assert (Norm_OK);
4043 -- In any case, call is fully resolved now. Reset Overload flag, to
4044 -- prevent subsequent overload resolution if node is analyzed again
4046 Set_Is_Overloaded (Subp, False);
4047 Set_Is_Overloaded (N, False);
4049 -- If we are calling the current subprogram from immediately within its
4050 -- body, then that is the case where we can sometimes detect cases of
4051 -- infinite recursion statically. Do not try this in case restriction
4052 -- No_Recursion is in effect anyway.
4054 Scop := Current_Scope;
4057 and then not Restriction_Active (No_Recursion)
4058 and then Check_Infinite_Recursion (N)
4060 -- Here we detected and flagged an infinite recursion, so we do
4061 -- not need to test the case below for further warnings.
4065 -- If call is to immediately containing subprogram, then check for
4066 -- the case of a possible run-time detectable infinite recursion.
4069 Scope_Loop : while Scop /= Standard_Standard loop
4072 -- Although in general recursion is not statically checkable,
4073 -- the case of calling an immediately containing subprogram
4074 -- is easy to catch.
4076 Check_Restriction (No_Recursion, N);
4078 -- If the recursive call is to a parameterless subprogram, then
4079 -- even if we can't statically detect infinite recursion, this
4080 -- is pretty suspicious, and we output a warning. Furthermore,
4081 -- we will try later to detect some cases here at run time by
4082 -- expanding checking code (see Detect_Infinite_Recursion in
4083 -- package Exp_Ch6).
4085 -- If the recursive call is within a handler we do not emit a
4086 -- warning, because this is a common idiom: loop until input
4087 -- is correct, catch illegal input in handler and restart.
4089 if No (First_Formal (Nam))
4090 and then Etype (Nam) = Standard_Void_Type
4091 and then not Error_Posted (N)
4092 and then Nkind (Parent (N)) /= N_Exception_Handler
4094 -- For the case of a procedure call. We give the message
4095 -- only if the call is the first statement in a sequence of
4096 -- statements, or if all previous statements are simple
4097 -- assignments. This is simply a heuristic to decrease false
4098 -- positives, without losing too many good warnings. The
4099 -- idea is that these previous statements may affect global
4100 -- variables the procedure depends on.
4102 if Nkind (N) = N_Procedure_Call_Statement
4103 and then Is_List_Member (N)
4109 while Present (P) loop
4110 if Nkind (P) /= N_Assignment_Statement then
4119 -- Do not give warning if we are in a conditional context
4122 K : constant Node_Kind := Nkind (Parent (N));
4124 if (K = N_Loop_Statement
4125 and then Present (Iteration_Scheme (Parent (N))))
4126 or else K = N_If_Statement
4127 or else K = N_Elsif_Part
4128 or else K = N_Case_Statement_Alternative
4134 -- Here warning is to be issued
4136 Set_Has_Recursive_Call (Nam);
4137 Error_Msg_N ("possible infinite recursion?", N);
4138 Error_Msg_N ("\Storage_Error may be raised at run time?", N);
4144 Scop := Scope (Scop);
4145 end loop Scope_Loop;
4148 -- If subprogram name is a predefined operator, it was given in
4149 -- functional notation. Replace call node with operator node, so
4150 -- that actuals can be resolved appropriately.
4152 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
4153 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
4156 elsif Present (Alias (Nam))
4157 and then Is_Predefined_Op (Alias (Nam))
4159 Resolve_Actuals (N, Nam);
4160 Make_Call_Into_Operator (N, Typ, Alias (Nam));
4164 -- Create a transient scope if the resulting type requires it
4166 -- There are 4 notable exceptions: in init procs, the transient scope
4167 -- overhead is not needed and even incorrect due to the actual expansion
4168 -- of adjust calls; the second case is enumeration literal pseudo calls;
4169 -- the third case is intrinsic subprograms (Unchecked_Conversion and
4170 -- source information functions) that do not use the secondary stack
4171 -- even though the return type is unconstrained; the fourth case is a
4172 -- call to a build-in-place function, since such functions may allocate
4173 -- their result directly in a target object, and cases where the result
4174 -- does get allocated in the secondary stack are checked for within the
4175 -- specialized Exp_Ch6 procedures for expanding build-in-place calls.
4177 -- If this is an initialization call for a type whose initialization
4178 -- uses the secondary stack, we also need to create a transient scope
4179 -- for it, precisely because we will not do it within the init proc
4182 -- If the subprogram is marked Inlined_Always, then even if it returns
4183 -- an unconstrained type the call does not require use of the secondary
4187 and then Present (First_Rep_Item (Nam))
4188 and then Nkind (First_Rep_Item (Nam)) = N_Pragma
4189 and then Chars (First_Rep_Item (Nam)) = Name_Inline_Always
4193 elsif Expander_Active
4194 and then Is_Type (Etype (Nam))
4195 and then Requires_Transient_Scope (Etype (Nam))
4196 and then not Is_Build_In_Place_Function (Nam)
4197 and then Ekind (Nam) /= E_Enumeration_Literal
4198 and then not Within_Init_Proc
4199 and then not Is_Intrinsic_Subprogram (Nam)
4201 Establish_Transient_Scope (N, Sec_Stack => True);
4203 -- If the call appears within the bounds of a loop, it will
4204 -- be rewritten and reanalyzed, nothing left to do here.
4206 if Nkind (N) /= N_Function_Call then
4210 elsif Is_Init_Proc (Nam)
4211 and then not Within_Init_Proc
4213 Check_Initialization_Call (N, Nam);
4216 -- A protected function cannot be called within the definition of the
4217 -- enclosing protected type.
4219 if Is_Protected_Type (Scope (Nam))
4220 and then In_Open_Scopes (Scope (Nam))
4221 and then not Has_Completion (Scope (Nam))
4224 ("& cannot be called before end of protected definition", N, Nam);
4227 -- Propagate interpretation to actuals, and add default expressions
4230 if Present (First_Formal (Nam)) then
4231 Resolve_Actuals (N, Nam);
4233 -- Overloaded literals are rewritten as function calls, for
4234 -- purpose of resolution. After resolution, we can replace
4235 -- the call with the literal itself.
4237 elsif Ekind (Nam) = E_Enumeration_Literal then
4238 Copy_Node (Subp, N);
4239 Resolve_Entity_Name (N, Typ);
4241 -- Avoid validation, since it is a static function call
4246 -- If the subprogram is not global, then kill all checks. This is a bit
4247 -- conservative, since in many cases we could do better, but it is not
4248 -- worth the effort. Similarly, we kill constant values. However we do
4249 -- not need to do this for internal entities (unless they are inherited
4250 -- user-defined subprograms), since they are not in the business of
4251 -- molesting global values.
4253 -- Note: we do not do this step till after resolving the actuals. That
4254 -- way we still take advantage of the current value information while
4255 -- scanning the actuals.
4257 if not Is_Library_Level_Entity (Nam)
4258 and then (Comes_From_Source (Nam)
4259 or else (Present (Alias (Nam))
4260 and then Comes_From_Source (Alias (Nam))))
4262 Kill_Current_Values;
4265 -- If the subprogram is a primitive operation, check whether or not
4266 -- it is a correct dispatching call.
4268 if Is_Overloadable (Nam)
4269 and then Is_Dispatching_Operation (Nam)
4271 Check_Dispatching_Call (N);
4273 elsif Ekind (Nam) /= E_Subprogram_Type
4274 and then Is_Abstract_Subprogram (Nam)
4275 and then not In_Instance
4277 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
4280 if Is_Intrinsic_Subprogram (Nam) then
4281 Check_Intrinsic_Call (N);
4285 Check_Elab_Call (N);
4288 -------------------------------
4289 -- Resolve_Character_Literal --
4290 -------------------------------
4292 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
4293 B_Typ : constant Entity_Id := Base_Type (Typ);
4297 -- Verify that the character does belong to the type of the context
4299 Set_Etype (N, B_Typ);
4300 Eval_Character_Literal (N);
4302 -- Wide_Wide_Character literals must always be defined, since the set
4303 -- of wide wide character literals is complete, i.e. if a character
4304 -- literal is accepted by the parser, then it is OK for wide wide
4305 -- character (out of range character literals are rejected).
4307 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
4310 -- Always accept character literal for type Any_Character, which
4311 -- occurs in error situations and in comparisons of literals, both
4312 -- of which should accept all literals.
4314 elsif B_Typ = Any_Character then
4317 -- For Standard.Character or a type derived from it, check that
4318 -- the literal is in range
4320 elsif Root_Type (B_Typ) = Standard_Character then
4321 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
4325 -- For Standard.Wide_Character or a type derived from it, check
4326 -- that the literal is in range
4328 elsif Root_Type (B_Typ) = Standard_Wide_Character then
4329 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
4333 -- For Standard.Wide_Wide_Character or a type derived from it, we
4334 -- know the literal is in range, since the parser checked!
4336 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
4339 -- If the entity is already set, this has already been resolved in
4340 -- a generic context, or comes from expansion. Nothing else to do.
4342 elsif Present (Entity (N)) then
4345 -- Otherwise we have a user defined character type, and we can use
4346 -- the standard visibility mechanisms to locate the referenced entity
4349 C := Current_Entity (N);
4350 while Present (C) loop
4351 if Etype (C) = B_Typ then
4352 Set_Entity_With_Style_Check (N, C);
4353 Generate_Reference (C, N);
4361 -- If we fall through, then the literal does not match any of the
4362 -- entries of the enumeration type. This isn't just a constraint
4363 -- error situation, it is an illegality (see RM 4.2).
4366 ("character not defined for }", N, First_Subtype (B_Typ));
4367 end Resolve_Character_Literal;
4369 ---------------------------
4370 -- Resolve_Comparison_Op --
4371 ---------------------------
4373 -- Context requires a boolean type, and plays no role in resolution.
4374 -- Processing identical to that for equality operators. The result
4375 -- type is the base type, which matters when pathological subtypes of
4376 -- booleans with limited ranges are used.
4378 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
4379 L : constant Node_Id := Left_Opnd (N);
4380 R : constant Node_Id := Right_Opnd (N);
4384 -- If this is an intrinsic operation which is not predefined, use
4385 -- the types of its declared arguments to resolve the possibly
4386 -- overloaded operands. Otherwise the operands are unambiguous and
4387 -- specify the expected type.
4389 if Scope (Entity (N)) /= Standard_Standard then
4390 T := Etype (First_Entity (Entity (N)));
4393 T := Find_Unique_Type (L, R);
4395 if T = Any_Fixed then
4396 T := Unique_Fixed_Point_Type (L);
4400 Set_Etype (N, Base_Type (Typ));
4401 Generate_Reference (T, N, ' ');
4403 if T /= Any_Type then
4405 or else T = Any_Composite
4406 or else T = Any_Character
4408 if T = Any_Character then
4409 Ambiguous_Character (L);
4411 Error_Msg_N ("ambiguous operands for comparison", N);
4414 Set_Etype (N, Any_Type);
4420 Check_Unset_Reference (L);
4421 Check_Unset_Reference (R);
4422 Generate_Operator_Reference (N, T);
4423 Eval_Relational_Op (N);
4426 end Resolve_Comparison_Op;
4428 ------------------------------------
4429 -- Resolve_Conditional_Expression --
4430 ------------------------------------
4432 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
4433 Condition : constant Node_Id := First (Expressions (N));
4434 Then_Expr : constant Node_Id := Next (Condition);
4435 Else_Expr : constant Node_Id := Next (Then_Expr);
4438 Resolve (Condition, Standard_Boolean);
4439 Resolve (Then_Expr, Typ);
4440 Resolve (Else_Expr, Typ);
4443 Eval_Conditional_Expression (N);
4444 end Resolve_Conditional_Expression;
4446 -----------------------------------------
4447 -- Resolve_Discrete_Subtype_Indication --
4448 -----------------------------------------
4450 procedure Resolve_Discrete_Subtype_Indication
4458 Analyze (Subtype_Mark (N));
4459 S := Entity (Subtype_Mark (N));
4461 if Nkind (Constraint (N)) /= N_Range_Constraint then
4462 Error_Msg_N ("expect range constraint for discrete type", N);
4463 Set_Etype (N, Any_Type);
4466 R := Range_Expression (Constraint (N));
4474 if Base_Type (S) /= Base_Type (Typ) then
4476 ("expect subtype of }", N, First_Subtype (Typ));
4478 -- Rewrite the constraint as a range of Typ
4479 -- to allow compilation to proceed further.
4482 Rewrite (Low_Bound (R),
4483 Make_Attribute_Reference (Sloc (Low_Bound (R)),
4484 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4485 Attribute_Name => Name_First));
4486 Rewrite (High_Bound (R),
4487 Make_Attribute_Reference (Sloc (High_Bound (R)),
4488 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4489 Attribute_Name => Name_First));
4493 Set_Etype (N, Etype (R));
4495 -- Additionally, we must check that the bounds are compatible
4496 -- with the given subtype, which might be different from the
4497 -- type of the context.
4499 Apply_Range_Check (R, S);
4501 -- ??? If the above check statically detects a Constraint_Error
4502 -- it replaces the offending bound(s) of the range R with a
4503 -- Constraint_Error node. When the itype which uses these bounds
4504 -- is frozen the resulting call to Duplicate_Subexpr generates
4505 -- a new temporary for the bounds.
4507 -- Unfortunately there are other itypes that are also made depend
4508 -- on these bounds, so when Duplicate_Subexpr is called they get
4509 -- a forward reference to the newly created temporaries and Gigi
4510 -- aborts on such forward references. This is probably sign of a
4511 -- more fundamental problem somewhere else in either the order of
4512 -- itype freezing or the way certain itypes are constructed.
4514 -- To get around this problem we call Remove_Side_Effects right
4515 -- away if either bounds of R are a Constraint_Error.
4518 L : constant Node_Id := Low_Bound (R);
4519 H : constant Node_Id := High_Bound (R);
4522 if Nkind (L) = N_Raise_Constraint_Error then
4523 Remove_Side_Effects (L);
4526 if Nkind (H) = N_Raise_Constraint_Error then
4527 Remove_Side_Effects (H);
4531 Check_Unset_Reference (Low_Bound (R));
4532 Check_Unset_Reference (High_Bound (R));
4535 end Resolve_Discrete_Subtype_Indication;
4537 -------------------------
4538 -- Resolve_Entity_Name --
4539 -------------------------
4541 -- Used to resolve identifiers and expanded names
4543 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
4544 E : constant Entity_Id := Entity (N);
4547 -- If garbage from errors, set to Any_Type and return
4549 if No (E) and then Total_Errors_Detected /= 0 then
4550 Set_Etype (N, Any_Type);
4554 -- Replace named numbers by corresponding literals. Note that this is
4555 -- the one case where Resolve_Entity_Name must reset the Etype, since
4556 -- it is currently marked as universal.
4558 if Ekind (E) = E_Named_Integer then
4560 Eval_Named_Integer (N);
4562 elsif Ekind (E) = E_Named_Real then
4564 Eval_Named_Real (N);
4566 -- Allow use of subtype only if it is a concurrent type where we are
4567 -- currently inside the body. This will eventually be expanded
4568 -- into a call to Self (for tasks) or _object (for protected
4569 -- objects). Any other use of a subtype is invalid.
4571 elsif Is_Type (E) then
4572 if Is_Concurrent_Type (E)
4573 and then In_Open_Scopes (E)
4578 ("invalid use of subtype mark in expression or call", N);
4581 -- Check discriminant use if entity is discriminant in current scope,
4582 -- i.e. discriminant of record or concurrent type currently being
4583 -- analyzed. Uses in corresponding body are unrestricted.
4585 elsif Ekind (E) = E_Discriminant
4586 and then Scope (E) = Current_Scope
4587 and then not Has_Completion (Current_Scope)
4589 Check_Discriminant_Use (N);
4591 -- A parameterless generic function cannot appear in a context that
4592 -- requires resolution.
4594 elsif Ekind (E) = E_Generic_Function then
4595 Error_Msg_N ("illegal use of generic function", N);
4597 elsif Ekind (E) = E_Out_Parameter
4598 and then Ada_Version = Ada_83
4599 and then (Nkind (Parent (N)) in N_Op
4600 or else (Nkind (Parent (N)) = N_Assignment_Statement
4601 and then N = Expression (Parent (N)))
4602 or else Nkind (Parent (N)) = N_Explicit_Dereference)
4604 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
4606 -- In all other cases, just do the possible static evaluation
4609 -- A deferred constant that appears in an expression must have
4610 -- a completion, unless it has been removed by in-place expansion
4613 if Ekind (E) = E_Constant
4614 and then Comes_From_Source (E)
4615 and then No (Constant_Value (E))
4616 and then Is_Frozen (Etype (E))
4617 and then not In_Default_Expression
4618 and then not Is_Imported (E)
4621 if No_Initialization (Parent (E))
4622 or else (Present (Full_View (E))
4623 and then No_Initialization (Parent (Full_View (E))))
4628 "deferred constant is frozen before completion", N);
4632 Eval_Entity_Name (N);
4634 end Resolve_Entity_Name;
4640 procedure Resolve_Entry (Entry_Name : Node_Id) is
4641 Loc : constant Source_Ptr := Sloc (Entry_Name);
4649 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
4650 -- If the bounds of the entry family being called depend on task
4651 -- discriminants, build a new index subtype where a discriminant is
4652 -- replaced with the value of the discriminant of the target task.
4653 -- The target task is the prefix of the entry name in the call.
4655 -----------------------
4656 -- Actual_Index_Type --
4657 -----------------------
4659 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
4660 Typ : constant Entity_Id := Entry_Index_Type (E);
4661 Tsk : constant Entity_Id := Scope (E);
4662 Lo : constant Node_Id := Type_Low_Bound (Typ);
4663 Hi : constant Node_Id := Type_High_Bound (Typ);
4666 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
4667 -- If the bound is given by a discriminant, replace with a reference
4668 -- to the discriminant of the same name in the target task.
4669 -- If the entry name is the target of a requeue statement and the
4670 -- entry is in the current protected object, the bound to be used
4671 -- is the discriminal of the object (see apply_range_checks for
4672 -- details of the transformation).
4674 -----------------------------
4675 -- Actual_Discriminant_Ref --
4676 -----------------------------
4678 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
4679 Typ : constant Entity_Id := Etype (Bound);
4683 Remove_Side_Effects (Bound);
4685 if not Is_Entity_Name (Bound)
4686 or else Ekind (Entity (Bound)) /= E_Discriminant
4690 elsif Is_Protected_Type (Tsk)
4691 and then In_Open_Scopes (Tsk)
4692 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
4694 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
4698 Make_Selected_Component (Loc,
4699 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
4700 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
4705 end Actual_Discriminant_Ref;
4707 -- Start of processing for Actual_Index_Type
4710 if not Has_Discriminants (Tsk)
4711 or else (not Is_Entity_Name (Lo)
4712 and then not Is_Entity_Name (Hi))
4714 return Entry_Index_Type (E);
4717 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
4718 Set_Etype (New_T, Base_Type (Typ));
4719 Set_Size_Info (New_T, Typ);
4720 Set_RM_Size (New_T, RM_Size (Typ));
4721 Set_Scalar_Range (New_T,
4722 Make_Range (Sloc (Entry_Name),
4723 Low_Bound => Actual_Discriminant_Ref (Lo),
4724 High_Bound => Actual_Discriminant_Ref (Hi)));
4728 end Actual_Index_Type;
4730 -- Start of processing of Resolve_Entry
4733 -- Find name of entry being called, and resolve prefix of name
4734 -- with its own type. The prefix can be overloaded, and the name
4735 -- and signature of the entry must be taken into account.
4737 if Nkind (Entry_Name) = N_Indexed_Component then
4739 -- Case of dealing with entry family within the current tasks
4741 E_Name := Prefix (Entry_Name);
4744 E_Name := Entry_Name;
4747 if Is_Entity_Name (E_Name) then
4748 -- Entry call to an entry (or entry family) in the current task.
4749 -- This is legal even though the task will deadlock. Rewrite as
4750 -- call to current task.
4752 -- This can also be a call to an entry in an enclosing task.
4753 -- If this is a single task, we have to retrieve its name,
4754 -- because the scope of the entry is the task type, not the
4755 -- object. If the enclosing task is a task type, the identity
4756 -- of the task is given by its own self variable.
4758 -- Finally this can be a requeue on an entry of the same task
4759 -- or protected object.
4761 S := Scope (Entity (E_Name));
4763 for J in reverse 0 .. Scope_Stack.Last loop
4765 if Is_Task_Type (Scope_Stack.Table (J).Entity)
4766 and then not Comes_From_Source (S)
4768 -- S is an enclosing task or protected object. The concurrent
4769 -- declaration has been converted into a type declaration, and
4770 -- the object itself has an object declaration that follows
4771 -- the type in the same declarative part.
4773 Tsk := Next_Entity (S);
4774 while Etype (Tsk) /= S loop
4781 elsif S = Scope_Stack.Table (J).Entity then
4783 -- Call to current task. Will be transformed into call to Self
4791 Make_Selected_Component (Loc,
4792 Prefix => New_Occurrence_Of (S, Loc),
4794 New_Occurrence_Of (Entity (E_Name), Loc));
4795 Rewrite (E_Name, New_N);
4798 elsif Nkind (Entry_Name) = N_Selected_Component
4799 and then Is_Overloaded (Prefix (Entry_Name))
4801 -- Use the entry name (which must be unique at this point) to
4802 -- find the prefix that returns the corresponding task type or
4806 Pref : constant Node_Id := Prefix (Entry_Name);
4807 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
4812 Get_First_Interp (Pref, I, It);
4813 while Present (It.Typ) loop
4814 if Scope (Ent) = It.Typ then
4815 Set_Etype (Pref, It.Typ);
4819 Get_Next_Interp (I, It);
4824 if Nkind (Entry_Name) = N_Selected_Component then
4825 Resolve (Prefix (Entry_Name));
4827 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4828 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4829 Resolve (Prefix (Prefix (Entry_Name)));
4830 Index := First (Expressions (Entry_Name));
4831 Resolve (Index, Entry_Index_Type (Nam));
4833 -- Up to this point the expression could have been the actual
4834 -- in a simple entry call, and be given by a named association.
4836 if Nkind (Index) = N_Parameter_Association then
4837 Error_Msg_N ("expect expression for entry index", Index);
4839 Apply_Range_Check (Index, Actual_Index_Type (Nam));
4844 ------------------------
4845 -- Resolve_Entry_Call --
4846 ------------------------
4848 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
4849 Entry_Name : constant Node_Id := Name (N);
4850 Loc : constant Source_Ptr := Sloc (Entry_Name);
4852 First_Named : Node_Id;
4859 -- We kill all checks here, because it does not seem worth the
4860 -- effort to do anything better, an entry call is a big operation.
4864 -- Processing of the name is similar for entry calls and protected
4865 -- operation calls. Once the entity is determined, we can complete
4866 -- the resolution of the actuals.
4868 -- The selector may be overloaded, in the case of a protected object
4869 -- with overloaded functions. The type of the context is used for
4872 if Nkind (Entry_Name) = N_Selected_Component
4873 and then Is_Overloaded (Selector_Name (Entry_Name))
4874 and then Typ /= Standard_Void_Type
4881 Get_First_Interp (Selector_Name (Entry_Name), I, It);
4882 while Present (It.Typ) loop
4883 if Covers (Typ, It.Typ) then
4884 Set_Entity (Selector_Name (Entry_Name), It.Nam);
4885 Set_Etype (Entry_Name, It.Typ);
4887 Generate_Reference (It.Typ, N, ' ');
4890 Get_Next_Interp (I, It);
4895 Resolve_Entry (Entry_Name);
4897 if Nkind (Entry_Name) = N_Selected_Component then
4899 -- Simple entry call
4901 Nam := Entity (Selector_Name (Entry_Name));
4902 Obj := Prefix (Entry_Name);
4903 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
4905 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4907 -- Call to member of entry family
4909 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4910 Obj := Prefix (Prefix (Entry_Name));
4911 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
4914 -- We cannot in general check the maximum depth of protected entry
4915 -- calls at compile time. But we can tell that any protected entry
4916 -- call at all violates a specified nesting depth of zero.
4918 if Is_Protected_Type (Scope (Nam)) then
4919 Check_Restriction (Max_Entry_Queue_Length, N);
4922 -- Use context type to disambiguate a protected function that can be
4923 -- called without actuals and that returns an array type, and where
4924 -- the argument list may be an indexing of the returned value.
4926 if Ekind (Nam) = E_Function
4927 and then Needs_No_Actuals (Nam)
4928 and then Present (Parameter_Associations (N))
4930 ((Is_Array_Type (Etype (Nam))
4931 and then Covers (Typ, Component_Type (Etype (Nam))))
4933 or else (Is_Access_Type (Etype (Nam))
4934 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4935 and then Covers (Typ,
4936 Component_Type (Designated_Type (Etype (Nam))))))
4939 Index_Node : Node_Id;
4943 Make_Indexed_Component (Loc,
4945 Make_Function_Call (Loc,
4946 Name => Relocate_Node (Entry_Name)),
4947 Expressions => Parameter_Associations (N));
4949 -- Since we are correcting a node classification error made by
4950 -- the parser, we call Replace rather than Rewrite.
4952 Replace (N, Index_Node);
4953 Set_Etype (Prefix (N), Etype (Nam));
4955 Resolve_Indexed_Component (N, Typ);
4960 -- The operation name may have been overloaded. Order the actuals
4961 -- according to the formals of the resolved entity, and set the
4962 -- return type to that of the operation.
4965 Normalize_Actuals (N, Nam, False, Norm_OK);
4966 pragma Assert (Norm_OK);
4967 Set_Etype (N, Etype (Nam));
4970 Resolve_Actuals (N, Nam);
4971 Generate_Reference (Nam, Entry_Name);
4973 if Ekind (Nam) = E_Entry
4974 or else Ekind (Nam) = E_Entry_Family
4976 Check_Potentially_Blocking_Operation (N);
4979 -- Verify that a procedure call cannot masquerade as an entry
4980 -- call where an entry call is expected.
4982 if Ekind (Nam) = E_Procedure then
4983 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4984 and then N = Entry_Call_Statement (Parent (N))
4986 Error_Msg_N ("entry call required in select statement", N);
4988 elsif Nkind (Parent (N)) = N_Triggering_Alternative
4989 and then N = Triggering_Statement (Parent (N))
4991 Error_Msg_N ("triggering statement cannot be procedure call", N);
4993 elsif Ekind (Scope (Nam)) = E_Task_Type
4994 and then not In_Open_Scopes (Scope (Nam))
4996 Error_Msg_N ("task has no entry with this name", Entry_Name);
5000 -- After resolution, entry calls and protected procedure calls
5001 -- are changed into entry calls, for expansion. The structure
5002 -- of the node does not change, so it can safely be done in place.
5003 -- Protected function calls must keep their structure because they
5004 -- are subexpressions.
5006 if Ekind (Nam) /= E_Function then
5008 -- A protected operation that is not a function may modify the
5009 -- corresponding object, and cannot apply to a constant.
5010 -- If this is an internal call, the prefix is the type itself.
5012 if Is_Protected_Type (Scope (Nam))
5013 and then not Is_Variable (Obj)
5014 and then (not Is_Entity_Name (Obj)
5015 or else not Is_Type (Entity (Obj)))
5018 ("prefix of protected procedure or entry call must be variable",
5022 Actuals := Parameter_Associations (N);
5023 First_Named := First_Named_Actual (N);
5026 Make_Entry_Call_Statement (Loc,
5028 Parameter_Associations => Actuals));
5030 Set_First_Named_Actual (N, First_Named);
5031 Set_Analyzed (N, True);
5033 -- Protected functions can return on the secondary stack, in which
5034 -- case we must trigger the transient scope mechanism.
5036 elsif Expander_Active
5037 and then Requires_Transient_Scope (Etype (Nam))
5039 Establish_Transient_Scope (N, Sec_Stack => True);
5041 end Resolve_Entry_Call;
5043 -------------------------
5044 -- Resolve_Equality_Op --
5045 -------------------------
5047 -- Both arguments must have the same type, and the boolean context
5048 -- does not participate in the resolution. The first pass verifies
5049 -- that the interpretation is not ambiguous, and the type of the left
5050 -- argument is correctly set, or is Any_Type in case of ambiguity.
5051 -- If both arguments are strings or aggregates, allocators, or Null,
5052 -- they are ambiguous even though they carry a single (universal) type.
5053 -- Diagnose this case here.
5055 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
5056 L : constant Node_Id := Left_Opnd (N);
5057 R : constant Node_Id := Right_Opnd (N);
5058 T : Entity_Id := Find_Unique_Type (L, R);
5060 function Find_Unique_Access_Type return Entity_Id;
5061 -- In the case of allocators, make a last-ditch attempt to find a single
5062 -- access type with the right designated type. This is semantically
5063 -- dubious, and of no interest to any real code, but c48008a makes it
5066 -----------------------------
5067 -- Find_Unique_Access_Type --
5068 -----------------------------
5070 function Find_Unique_Access_Type return Entity_Id is
5076 if Ekind (Etype (R)) = E_Allocator_Type then
5077 Acc := Designated_Type (Etype (R));
5079 elsif Ekind (Etype (L)) = E_Allocator_Type then
5080 Acc := Designated_Type (Etype (L));
5087 while S /= Standard_Standard loop
5088 E := First_Entity (S);
5089 while Present (E) loop
5091 and then Is_Access_Type (E)
5092 and then Ekind (E) /= E_Allocator_Type
5093 and then Designated_Type (E) = Base_Type (Acc)
5105 end Find_Unique_Access_Type;
5107 -- Start of processing for Resolve_Equality_Op
5110 Set_Etype (N, Base_Type (Typ));
5111 Generate_Reference (T, N, ' ');
5113 if T = Any_Fixed then
5114 T := Unique_Fixed_Point_Type (L);
5117 if T /= Any_Type then
5119 or else T = Any_Composite
5120 or else T = Any_Character
5122 if T = Any_Character then
5123 Ambiguous_Character (L);
5125 Error_Msg_N ("ambiguous operands for equality", N);
5128 Set_Etype (N, Any_Type);
5131 elsif T = Any_Access
5132 or else Ekind (T) = E_Allocator_Type
5133 or else Ekind (T) = E_Access_Attribute_Type
5135 T := Find_Unique_Access_Type;
5138 Error_Msg_N ("ambiguous operands for equality", N);
5139 Set_Etype (N, Any_Type);
5147 -- If the unique type is a class-wide type then it will be expanded
5148 -- into a dispatching call to the predefined primitive. Therefore we
5149 -- check here for potential violation of such restriction.
5151 if Is_Class_Wide_Type (T) then
5152 Check_Restriction (No_Dispatching_Calls, N);
5155 if Warn_On_Redundant_Constructs
5156 and then Comes_From_Source (N)
5157 and then Is_Entity_Name (R)
5158 and then Entity (R) = Standard_True
5159 and then Comes_From_Source (R)
5161 Error_Msg_N ("comparison with True is redundant?", R);
5164 Check_Unset_Reference (L);
5165 Check_Unset_Reference (R);
5166 Generate_Operator_Reference (N, T);
5168 -- If this is an inequality, it may be the implicit inequality
5169 -- created for a user-defined operation, in which case the corres-
5170 -- ponding equality operation is not intrinsic, and the operation
5171 -- cannot be constant-folded. Else fold.
5173 if Nkind (N) = N_Op_Eq
5174 or else Comes_From_Source (Entity (N))
5175 or else Ekind (Entity (N)) = E_Operator
5176 or else Is_Intrinsic_Subprogram
5177 (Corresponding_Equality (Entity (N)))
5179 Eval_Relational_Op (N);
5180 elsif Nkind (N) = N_Op_Ne
5181 and then Is_Abstract_Subprogram (Entity (N))
5183 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
5186 -- Ada 2005: If one operand is an anonymous access type, convert
5187 -- the other operand to it, to ensure that the underlying types
5188 -- match in the back-end.
5189 -- We apply the same conversion in the case one of the operands is
5190 -- a private subtype of the type of the other.
5193 and then (Ekind (T) = E_Anonymous_Access_Type
5194 or else Is_Private_Type (T))
5196 if Etype (L) /= T then
5198 Make_Unchecked_Type_Conversion (Sloc (L),
5199 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
5200 Expression => Relocate_Node (L)));
5201 Analyze_And_Resolve (L, T);
5204 if (Etype (R)) /= T then
5206 Make_Unchecked_Type_Conversion (Sloc (R),
5207 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
5208 Expression => Relocate_Node (R)));
5209 Analyze_And_Resolve (R, T);
5213 end Resolve_Equality_Op;
5215 ----------------------------------
5216 -- Resolve_Explicit_Dereference --
5217 ----------------------------------
5219 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
5220 Loc : constant Source_Ptr := Sloc (N);
5222 P : constant Node_Id := Prefix (N);
5227 Check_Fully_Declared_Prefix (Typ, P);
5229 if Is_Overloaded (P) then
5231 -- Use the context type to select the prefix that has the correct
5234 Get_First_Interp (P, I, It);
5235 while Present (It.Typ) loop
5236 exit when Is_Access_Type (It.Typ)
5237 and then Covers (Typ, Designated_Type (It.Typ));
5238 Get_Next_Interp (I, It);
5241 if Present (It.Typ) then
5242 Resolve (P, It.Typ);
5244 -- If no interpretation covers the designated type of the prefix,
5245 -- this is the pathological case where not all implementations of
5246 -- the prefix allow the interpretation of the node as a call. Now
5247 -- that the expected type is known, Remove other interpretations
5248 -- from prefix, rewrite it as a call, and resolve again, so that
5249 -- the proper call node is generated.
5251 Get_First_Interp (P, I, It);
5252 while Present (It.Typ) loop
5253 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
5257 Get_Next_Interp (I, It);
5261 Make_Function_Call (Loc,
5263 Make_Explicit_Dereference (Loc,
5265 Parameter_Associations => New_List);
5267 Save_Interps (N, New_N);
5269 Analyze_And_Resolve (N, Typ);
5273 Set_Etype (N, Designated_Type (It.Typ));
5279 if Is_Access_Type (Etype (P)) then
5280 Apply_Access_Check (N);
5283 -- If the designated type is a packed unconstrained array type, and the
5284 -- explicit dereference is not in the context of an attribute reference,
5285 -- then we must compute and set the actual subtype, since it is needed
5286 -- by Gigi. The reason we exclude the attribute case is that this is
5287 -- handled fine by Gigi, and in fact we use such attributes to build the
5288 -- actual subtype. We also exclude generated code (which builds actual
5289 -- subtypes directly if they are needed).
5291 if Is_Array_Type (Etype (N))
5292 and then Is_Packed (Etype (N))
5293 and then not Is_Constrained (Etype (N))
5294 and then Nkind (Parent (N)) /= N_Attribute_Reference
5295 and then Comes_From_Source (N)
5297 Set_Etype (N, Get_Actual_Subtype (N));
5300 -- Note: there is no Eval processing required for an explicit deference,
5301 -- because the type is known to be an allocators, and allocator
5302 -- expressions can never be static.
5304 end Resolve_Explicit_Dereference;
5306 -------------------------------
5307 -- Resolve_Indexed_Component --
5308 -------------------------------
5310 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
5311 Name : constant Node_Id := Prefix (N);
5313 Array_Type : Entity_Id := Empty; -- to prevent junk warning
5317 if Is_Overloaded (Name) then
5319 -- Use the context type to select the prefix that yields the correct
5325 I1 : Interp_Index := 0;
5326 P : constant Node_Id := Prefix (N);
5327 Found : Boolean := False;
5330 Get_First_Interp (P, I, It);
5331 while Present (It.Typ) loop
5332 if (Is_Array_Type (It.Typ)
5333 and then Covers (Typ, Component_Type (It.Typ)))
5334 or else (Is_Access_Type (It.Typ)
5335 and then Is_Array_Type (Designated_Type (It.Typ))
5337 (Typ, Component_Type (Designated_Type (It.Typ))))
5340 It := Disambiguate (P, I1, I, Any_Type);
5342 if It = No_Interp then
5343 Error_Msg_N ("ambiguous prefix for indexing", N);
5349 Array_Type := It.Typ;
5355 Array_Type := It.Typ;
5360 Get_Next_Interp (I, It);
5365 Array_Type := Etype (Name);
5368 Resolve (Name, Array_Type);
5369 Array_Type := Get_Actual_Subtype_If_Available (Name);
5371 -- If prefix is access type, dereference to get real array type.
5372 -- Note: we do not apply an access check because the expander always
5373 -- introduces an explicit dereference, and the check will happen there.
5375 if Is_Access_Type (Array_Type) then
5376 Array_Type := Designated_Type (Array_Type);
5379 -- If name was overloaded, set component type correctly now
5381 Set_Etype (N, Component_Type (Array_Type));
5383 Index := First_Index (Array_Type);
5384 Expr := First (Expressions (N));
5386 -- The prefix may have resolved to a string literal, in which case its
5387 -- etype has a special representation. This is only possible currently
5388 -- if the prefix is a static concatenation, written in functional
5391 if Ekind (Array_Type) = E_String_Literal_Subtype then
5392 Resolve (Expr, Standard_Positive);
5395 while Present (Index) and Present (Expr) loop
5396 Resolve (Expr, Etype (Index));
5397 Check_Unset_Reference (Expr);
5399 if Is_Scalar_Type (Etype (Expr)) then
5400 Apply_Scalar_Range_Check (Expr, Etype (Index));
5402 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
5410 -- Do not generate the warning on suspicious index if we are analyzing
5411 -- package Ada.Tags; otherwise we will report the warning with the
5412 -- Prims_Ptr field of the dispatch table.
5414 if Scope (Etype (Prefix (N))) = Standard_Standard
5416 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
5419 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
5420 Eval_Indexed_Component (N);
5422 end Resolve_Indexed_Component;
5424 -----------------------------
5425 -- Resolve_Integer_Literal --
5426 -----------------------------
5428 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
5431 Eval_Integer_Literal (N);
5432 end Resolve_Integer_Literal;
5434 --------------------------------
5435 -- Resolve_Intrinsic_Operator --
5436 --------------------------------
5438 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
5439 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
5446 while Scope (Op) /= Standard_Standard loop
5448 pragma Assert (Present (Op));
5452 Set_Is_Overloaded (N, False);
5454 -- If the operand type is private, rewrite with suitable conversions on
5455 -- the operands and the result, to expose the proper underlying numeric
5458 if Is_Private_Type (Typ) then
5459 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
5461 if Nkind (N) = N_Op_Expon then
5462 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
5464 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5467 Save_Interps (Left_Opnd (N), Expression (Arg1));
5468 Save_Interps (Right_Opnd (N), Expression (Arg2));
5470 Set_Left_Opnd (N, Arg1);
5471 Set_Right_Opnd (N, Arg2);
5473 Set_Etype (N, Btyp);
5474 Rewrite (N, Unchecked_Convert_To (Typ, N));
5477 elsif Typ /= Etype (Left_Opnd (N))
5478 or else Typ /= Etype (Right_Opnd (N))
5480 -- Add explicit conversion where needed, and save interpretations
5481 -- in case operands are overloaded.
5483 Arg1 := Convert_To (Typ, Left_Opnd (N));
5484 Arg2 := Convert_To (Typ, Right_Opnd (N));
5486 if Nkind (Arg1) = N_Type_Conversion then
5487 Save_Interps (Left_Opnd (N), Expression (Arg1));
5489 Save_Interps (Left_Opnd (N), Arg1);
5492 if Nkind (Arg2) = N_Type_Conversion then
5493 Save_Interps (Right_Opnd (N), Expression (Arg2));
5495 Save_Interps (Right_Opnd (N), Arg2);
5498 Rewrite (Left_Opnd (N), Arg1);
5499 Rewrite (Right_Opnd (N), Arg2);
5502 Resolve_Arithmetic_Op (N, Typ);
5505 Resolve_Arithmetic_Op (N, Typ);
5507 end Resolve_Intrinsic_Operator;
5509 --------------------------------------
5510 -- Resolve_Intrinsic_Unary_Operator --
5511 --------------------------------------
5513 procedure Resolve_Intrinsic_Unary_Operator
5517 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
5523 while Scope (Op) /= Standard_Standard loop
5525 pragma Assert (Present (Op));
5530 if Is_Private_Type (Typ) then
5531 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5532 Save_Interps (Right_Opnd (N), Expression (Arg2));
5534 Set_Right_Opnd (N, Arg2);
5536 Set_Etype (N, Btyp);
5537 Rewrite (N, Unchecked_Convert_To (Typ, N));
5541 Resolve_Unary_Op (N, Typ);
5543 end Resolve_Intrinsic_Unary_Operator;
5545 ------------------------
5546 -- Resolve_Logical_Op --
5547 ------------------------
5549 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
5551 N_Opr : constant Node_Kind := Nkind (N);
5554 -- Predefined operations on scalar types yield the base type. On the
5555 -- other hand, logical operations on arrays yield the type of the
5556 -- arguments (and the context).
5558 if Is_Array_Type (Typ) then
5561 B_Typ := Base_Type (Typ);
5564 -- The following test is required because the operands of the operation
5565 -- may be literals, in which case the resulting type appears to be
5566 -- compatible with a signed integer type, when in fact it is compatible
5567 -- only with modular types. If the context itself is universal, the
5568 -- operation is illegal.
5570 if not Valid_Boolean_Arg (Typ) then
5571 Error_Msg_N ("invalid context for logical operation", N);
5572 Set_Etype (N, Any_Type);
5575 elsif Typ = Any_Modular then
5577 ("no modular type available in this context", N);
5578 Set_Etype (N, Any_Type);
5580 elsif Is_Modular_Integer_Type (Typ)
5581 and then Etype (Left_Opnd (N)) = Universal_Integer
5582 and then Etype (Right_Opnd (N)) = Universal_Integer
5584 Check_For_Visible_Operator (N, B_Typ);
5587 Resolve (Left_Opnd (N), B_Typ);
5588 Resolve (Right_Opnd (N), B_Typ);
5590 Check_Unset_Reference (Left_Opnd (N));
5591 Check_Unset_Reference (Right_Opnd (N));
5593 Set_Etype (N, B_Typ);
5594 Generate_Operator_Reference (N, B_Typ);
5595 Eval_Logical_Op (N);
5597 -- Check for violation of restriction No_Direct_Boolean_Operators
5598 -- if the operator was not eliminated by the Eval_Logical_Op call.
5600 if Nkind (N) = N_Opr
5601 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
5603 Check_Restriction (No_Direct_Boolean_Operators, N);
5605 end Resolve_Logical_Op;
5607 ---------------------------
5608 -- Resolve_Membership_Op --
5609 ---------------------------
5611 -- The context can only be a boolean type, and does not determine
5612 -- the arguments. Arguments should be unambiguous, but the preference
5613 -- rule for universal types applies.
5615 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
5616 pragma Warnings (Off, Typ);
5618 L : constant Node_Id := Left_Opnd (N);
5619 R : constant Node_Id := Right_Opnd (N);
5623 if L = Error or else R = Error then
5627 if not Is_Overloaded (R)
5629 (Etype (R) = Universal_Integer or else
5630 Etype (R) = Universal_Real)
5631 and then Is_Overloaded (L)
5635 -- Ada 2005 (AI-251): Give support to the following case:
5637 -- type I is interface;
5638 -- type T is tagged ...
5640 -- function Test (O : I'Class) is
5642 -- return O in T'Class.
5645 -- In this case we have nothing else to do; the membership test will be
5646 -- done at run-time.
5648 elsif Ada_Version >= Ada_05
5649 and then Is_Class_Wide_Type (Etype (L))
5650 and then Is_Interface (Etype (L))
5651 and then Is_Class_Wide_Type (Etype (R))
5652 and then not Is_Interface (Etype (R))
5657 T := Intersect_Types (L, R);
5661 Check_Unset_Reference (L);
5663 if Nkind (R) = N_Range
5664 and then not Is_Scalar_Type (T)
5666 Error_Msg_N ("scalar type required for range", R);
5669 if Is_Entity_Name (R) then
5670 Freeze_Expression (R);
5673 Check_Unset_Reference (R);
5676 Eval_Membership_Op (N);
5677 end Resolve_Membership_Op;
5683 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
5685 -- Handle restriction against anonymous null access values This
5686 -- restriction can be turned off using -gnatdh.
5688 -- Ada 2005 (AI-231): Remove restriction
5690 if Ada_Version < Ada_05
5691 and then not Debug_Flag_J
5692 and then Ekind (Typ) = E_Anonymous_Access_Type
5693 and then Comes_From_Source (N)
5695 -- In the common case of a call which uses an explicitly null
5696 -- value for an access parameter, give specialized error msg
5698 if Nkind (Parent (N)) = N_Procedure_Call_Statement
5700 Nkind (Parent (N)) = N_Function_Call
5703 ("null is not allowed as argument for an access parameter", N);
5705 -- Standard message for all other cases (are there any?)
5709 ("null cannot be of an anonymous access type", N);
5713 -- In a distributed context, null for a remote access to subprogram
5714 -- may need to be replaced with a special record aggregate. In this
5715 -- case, return after having done the transformation.
5717 if (Ekind (Typ) = E_Record_Type
5718 or else Is_Remote_Access_To_Subprogram_Type (Typ))
5719 and then Remote_AST_Null_Value (N, Typ)
5724 -- The null literal takes its type from the context
5729 -----------------------
5730 -- Resolve_Op_Concat --
5731 -----------------------
5733 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
5734 Btyp : constant Entity_Id := Base_Type (Typ);
5735 Op1 : constant Node_Id := Left_Opnd (N);
5736 Op2 : constant Node_Id := Right_Opnd (N);
5738 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean);
5739 -- Internal procedure to resolve one operand of concatenation operator.
5740 -- The operand is either of the array type or of the component type.
5741 -- If the operand is an aggregate, and the component type is composite,
5742 -- this is ambiguous if component type has aggregates.
5744 -------------------------------
5745 -- Resolve_Concatenation_Arg --
5746 -------------------------------
5748 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean) is
5752 or else (not Is_Overloaded (Arg)
5753 and then Etype (Arg) /= Any_Composite
5754 and then Covers (Component_Type (Typ), Etype (Arg)))
5756 Resolve (Arg, Component_Type (Typ));
5758 Resolve (Arg, Btyp);
5761 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
5763 if Nkind (Arg) = N_Aggregate
5764 and then Is_Composite_Type (Component_Type (Typ))
5766 if Is_Private_Type (Component_Type (Typ)) then
5767 Resolve (Arg, Btyp);
5770 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
5771 Set_Etype (Arg, Any_Type);
5775 if Is_Overloaded (Arg)
5776 and then Has_Compatible_Type (Arg, Typ)
5777 and then Etype (Arg) /= Any_Type
5786 Get_First_Interp (Arg, I, It);
5788 Get_Next_Interp (I, It);
5790 -- Special-case the error message when the overloading
5791 -- is caused by a function that yields and array and
5792 -- can be called without parameters.
5794 if It.Nam = Func then
5795 Error_Msg_Sloc := Sloc (Func);
5796 Error_Msg_N ("\ambiguous call to function#", Arg);
5798 ("\\interpretation as call yields&", Arg, Typ);
5800 ("\\interpretation as indexing of call yields&",
5801 Arg, Component_Type (Typ));
5805 ("ambiguous operand for concatenation!", Arg);
5806 Get_First_Interp (Arg, I, It);
5807 while Present (It.Nam) loop
5808 Error_Msg_Sloc := Sloc (It.Nam);
5810 if Base_Type (It.Typ) = Base_Type (Typ)
5811 or else Base_Type (It.Typ) =
5812 Base_Type (Component_Type (Typ))
5814 Error_Msg_N ("\\possible interpretation#", Arg);
5817 Get_Next_Interp (I, It);
5823 Resolve (Arg, Component_Type (Typ));
5825 if Nkind (Arg) = N_String_Literal then
5826 Set_Etype (Arg, Component_Type (Typ));
5829 if Arg = Left_Opnd (N) then
5830 Set_Is_Component_Left_Opnd (N);
5832 Set_Is_Component_Right_Opnd (N);
5837 Resolve (Arg, Btyp);
5840 Check_Unset_Reference (Arg);
5841 end Resolve_Concatenation_Arg;
5843 -- Start of processing for Resolve_Op_Concat
5846 Set_Etype (N, Btyp);
5848 if Is_Limited_Composite (Btyp) then
5849 Error_Msg_N ("concatenation not available for limited array", N);
5850 Explain_Limited_Type (Btyp, N);
5853 -- If the operands are themselves concatenations, resolve them as such
5854 -- directly. This removes several layers of recursion and allows GNAT to
5855 -- handle larger multiple concatenations.
5857 if Nkind (Op1) = N_Op_Concat
5858 and then not Is_Array_Type (Component_Type (Typ))
5859 and then Entity (Op1) = Entity (N)
5861 Resolve_Op_Concat (Op1, Typ);
5863 Resolve_Concatenation_Arg
5864 (Op1, Is_Component_Left_Opnd (N));
5867 if Nkind (Op2) = N_Op_Concat
5868 and then not Is_Array_Type (Component_Type (Typ))
5869 and then Entity (Op2) = Entity (N)
5871 Resolve_Op_Concat (Op2, Typ);
5873 Resolve_Concatenation_Arg
5874 (Op2, Is_Component_Right_Opnd (N));
5877 Generate_Operator_Reference (N, Typ);
5879 if Is_String_Type (Typ) then
5880 Eval_Concatenation (N);
5883 -- If this is not a static concatenation, but the result is a
5884 -- string type (and not an array of strings) insure that static
5885 -- string operands have their subtypes properly constructed.
5887 if Nkind (N) /= N_String_Literal
5888 and then Is_Character_Type (Component_Type (Typ))
5890 Set_String_Literal_Subtype (Op1, Typ);
5891 Set_String_Literal_Subtype (Op2, Typ);
5893 end Resolve_Op_Concat;
5895 ----------------------
5896 -- Resolve_Op_Expon --
5897 ----------------------
5899 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
5900 B_Typ : constant Entity_Id := Base_Type (Typ);
5903 -- Catch attempts to do fixed-point exponentation with universal
5904 -- operands, which is a case where the illegality is not caught during
5905 -- normal operator analysis.
5907 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
5908 Error_Msg_N ("exponentiation not available for fixed point", N);
5912 if Comes_From_Source (N)
5913 and then Ekind (Entity (N)) = E_Function
5914 and then Is_Imported (Entity (N))
5915 and then Is_Intrinsic_Subprogram (Entity (N))
5917 Resolve_Intrinsic_Operator (N, Typ);
5921 if Etype (Left_Opnd (N)) = Universal_Integer
5922 or else Etype (Left_Opnd (N)) = Universal_Real
5924 Check_For_Visible_Operator (N, B_Typ);
5927 -- We do the resolution using the base type, because intermediate values
5928 -- in expressions always are of the base type, not a subtype of it.
5930 Resolve (Left_Opnd (N), B_Typ);
5931 Resolve (Right_Opnd (N), Standard_Integer);
5933 Check_Unset_Reference (Left_Opnd (N));
5934 Check_Unset_Reference (Right_Opnd (N));
5936 Set_Etype (N, B_Typ);
5937 Generate_Operator_Reference (N, B_Typ);
5940 -- Set overflow checking bit. Much cleverer code needed here eventually
5941 -- and perhaps the Resolve routines should be separated for the various
5942 -- arithmetic operations, since they will need different processing. ???
5944 if Nkind (N) in N_Op then
5945 if not Overflow_Checks_Suppressed (Etype (N)) then
5946 Enable_Overflow_Check (N);
5949 end Resolve_Op_Expon;
5951 --------------------
5952 -- Resolve_Op_Not --
5953 --------------------
5955 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
5958 function Parent_Is_Boolean return Boolean;
5959 -- This function determines if the parent node is a boolean operator
5960 -- or operation (comparison op, membership test, or short circuit form)
5961 -- and the not in question is the left operand of this operation.
5962 -- Note that if the not is in parens, then false is returned.
5964 -----------------------
5965 -- Parent_Is_Boolean --
5966 -----------------------
5968 function Parent_Is_Boolean return Boolean is
5970 if Paren_Count (N) /= 0 then
5974 case Nkind (Parent (N)) is
5989 return Left_Opnd (Parent (N)) = N;
5995 end Parent_Is_Boolean;
5997 -- Start of processing for Resolve_Op_Not
6000 -- Predefined operations on scalar types yield the base type. On the
6001 -- other hand, logical operations on arrays yield the type of the
6002 -- arguments (and the context).
6004 if Is_Array_Type (Typ) then
6007 B_Typ := Base_Type (Typ);
6010 -- Straigtforward case of incorrect arguments
6012 if not Valid_Boolean_Arg (Typ) then
6013 Error_Msg_N ("invalid operand type for operator&", N);
6014 Set_Etype (N, Any_Type);
6017 -- Special case of probable missing parens
6019 elsif Typ = Universal_Integer or else Typ = Any_Modular then
6020 if Parent_Is_Boolean then
6022 ("operand of not must be enclosed in parentheses",
6026 ("no modular type available in this context", N);
6029 Set_Etype (N, Any_Type);
6032 -- OK resolution of not
6035 -- Warn if non-boolean types involved. This is a case like not a < b
6036 -- where a and b are modular, where we will get (not a) < b and most
6037 -- likely not (a < b) was intended.
6039 if Warn_On_Questionable_Missing_Parens
6040 and then not Is_Boolean_Type (Typ)
6041 and then Parent_Is_Boolean
6043 Error_Msg_N ("?not expression should be parenthesized here", N);
6046 Resolve (Right_Opnd (N), B_Typ);
6047 Check_Unset_Reference (Right_Opnd (N));
6048 Set_Etype (N, B_Typ);
6049 Generate_Operator_Reference (N, B_Typ);
6054 -----------------------------
6055 -- Resolve_Operator_Symbol --
6056 -----------------------------
6058 -- Nothing to be done, all resolved already
6060 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
6061 pragma Warnings (Off, N);
6062 pragma Warnings (Off, Typ);
6066 end Resolve_Operator_Symbol;
6068 ----------------------------------
6069 -- Resolve_Qualified_Expression --
6070 ----------------------------------
6072 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
6073 pragma Warnings (Off, Typ);
6075 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
6076 Expr : constant Node_Id := Expression (N);
6079 Resolve (Expr, Target_Typ);
6081 -- A qualified expression requires an exact match of the type,
6082 -- class-wide matching is not allowed. However, if the qualifying
6083 -- type is specific and the expression has a class-wide type, it
6084 -- may still be okay, since it can be the result of the expansion
6085 -- of a call to a dispatching function, so we also have to check
6086 -- class-wideness of the type of the expression's original node.
6088 if (Is_Class_Wide_Type (Target_Typ)
6090 (Is_Class_Wide_Type (Etype (Expr))
6091 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
6092 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
6094 Wrong_Type (Expr, Target_Typ);
6097 -- If the target type is unconstrained, then we reset the type of
6098 -- the result from the type of the expression. For other cases, the
6099 -- actual subtype of the expression is the target type.
6101 if Is_Composite_Type (Target_Typ)
6102 and then not Is_Constrained (Target_Typ)
6104 Set_Etype (N, Etype (Expr));
6107 Eval_Qualified_Expression (N);
6108 end Resolve_Qualified_Expression;
6114 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
6115 L : constant Node_Id := Low_Bound (N);
6116 H : constant Node_Id := High_Bound (N);
6123 Check_Unset_Reference (L);
6124 Check_Unset_Reference (H);
6126 -- We have to check the bounds for being within the base range as
6127 -- required for a non-static context. Normally this is automatic and
6128 -- done as part of evaluating expressions, but the N_Range node is an
6129 -- exception, since in GNAT we consider this node to be a subexpression,
6130 -- even though in Ada it is not. The circuit in Sem_Eval could check for
6131 -- this, but that would put the test on the main evaluation path for
6134 Check_Non_Static_Context (L);
6135 Check_Non_Static_Context (H);
6137 -- If bounds are static, constant-fold them, so size computations
6138 -- are identical between front-end and back-end. Do not perform this
6139 -- transformation while analyzing generic units, as type information
6140 -- would then be lost when reanalyzing the constant node in the
6143 if Is_Discrete_Type (Typ) and then Expander_Active then
6144 if Is_OK_Static_Expression (L) then
6145 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
6148 if Is_OK_Static_Expression (H) then
6149 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
6154 --------------------------
6155 -- Resolve_Real_Literal --
6156 --------------------------
6158 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
6159 Actual_Typ : constant Entity_Id := Etype (N);
6162 -- Special processing for fixed-point literals to make sure that the
6163 -- value is an exact multiple of small where this is required. We
6164 -- skip this for the universal real case, and also for generic types.
6166 if Is_Fixed_Point_Type (Typ)
6167 and then Typ /= Universal_Fixed
6168 and then Typ /= Any_Fixed
6169 and then not Is_Generic_Type (Typ)
6172 Val : constant Ureal := Realval (N);
6173 Cintr : constant Ureal := Val / Small_Value (Typ);
6174 Cint : constant Uint := UR_Trunc (Cintr);
6175 Den : constant Uint := Norm_Den (Cintr);
6179 -- Case of literal is not an exact multiple of the Small
6183 -- For a source program literal for a decimal fixed-point
6184 -- type, this is statically illegal (RM 4.9(36)).
6186 if Is_Decimal_Fixed_Point_Type (Typ)
6187 and then Actual_Typ = Universal_Real
6188 and then Comes_From_Source (N)
6190 Error_Msg_N ("value has extraneous low order digits", N);
6193 -- Generate a warning if literal from source
6195 if Is_Static_Expression (N)
6196 and then Warn_On_Bad_Fixed_Value
6199 ("static fixed-point value is not a multiple of Small?",
6203 -- Replace literal by a value that is the exact representation
6204 -- of a value of the type, i.e. a multiple of the small value,
6205 -- by truncation, since Machine_Rounds is false for all GNAT
6206 -- fixed-point types (RM 4.9(38)).
6208 Stat := Is_Static_Expression (N);
6210 Make_Real_Literal (Sloc (N),
6211 Realval => Small_Value (Typ) * Cint));
6213 Set_Is_Static_Expression (N, Stat);
6216 -- In all cases, set the corresponding integer field
6218 Set_Corresponding_Integer_Value (N, Cint);
6222 -- Now replace the actual type by the expected type as usual
6225 Eval_Real_Literal (N);
6226 end Resolve_Real_Literal;
6228 -----------------------
6229 -- Resolve_Reference --
6230 -----------------------
6232 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
6233 P : constant Node_Id := Prefix (N);
6236 -- Replace general access with specific type
6238 if Ekind (Etype (N)) = E_Allocator_Type then
6239 Set_Etype (N, Base_Type (Typ));
6242 Resolve (P, Designated_Type (Etype (N)));
6244 -- If we are taking the reference of a volatile entity, then treat
6245 -- it as a potential modification of this entity. This is much too
6246 -- conservative, but is necessary because remove side effects can
6247 -- result in transformations of normal assignments into reference
6248 -- sequences that otherwise fail to notice the modification.
6250 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
6251 Note_Possible_Modification (P);
6253 end Resolve_Reference;
6255 --------------------------------
6256 -- Resolve_Selected_Component --
6257 --------------------------------
6259 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
6261 Comp1 : Entity_Id := Empty; -- prevent junk warning
6262 P : constant Node_Id := Prefix (N);
6263 S : constant Node_Id := Selector_Name (N);
6264 T : Entity_Id := Etype (P);
6266 I1 : Interp_Index := 0; -- prevent junk warning
6271 function Init_Component return Boolean;
6272 -- Check whether this is the initialization of a component within an
6273 -- init proc (by assignment or call to another init proc). If true,
6274 -- there is no need for a discriminant check.
6276 --------------------
6277 -- Init_Component --
6278 --------------------
6280 function Init_Component return Boolean is
6282 return Inside_Init_Proc
6283 and then Nkind (Prefix (N)) = N_Identifier
6284 and then Chars (Prefix (N)) = Name_uInit
6285 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
6288 -- Start of processing for Resolve_Selected_Component
6291 if Is_Overloaded (P) then
6293 -- Use the context type to select the prefix that has a selector
6294 -- of the correct name and type.
6297 Get_First_Interp (P, I, It);
6299 Search : while Present (It.Typ) loop
6300 if Is_Access_Type (It.Typ) then
6301 T := Designated_Type (It.Typ);
6306 if Is_Record_Type (T) then
6307 Comp := First_Entity (T);
6308 while Present (Comp) loop
6309 if Chars (Comp) = Chars (S)
6310 and then Covers (Etype (Comp), Typ)
6319 It := Disambiguate (P, I1, I, Any_Type);
6321 if It = No_Interp then
6323 ("ambiguous prefix for selected component", N);
6330 -- There may be an implicit dereference. Retrieve
6331 -- designated record type.
6333 if Is_Access_Type (It1.Typ) then
6334 T := Designated_Type (It1.Typ);
6339 if Scope (Comp1) /= T then
6341 -- Resolution chooses the new interpretation.
6342 -- Find the component with the right name.
6344 Comp1 := First_Entity (T);
6345 while Present (Comp1)
6346 and then Chars (Comp1) /= Chars (S)
6348 Comp1 := Next_Entity (Comp1);
6357 Comp := Next_Entity (Comp);
6362 Get_Next_Interp (I, It);
6365 Resolve (P, It1.Typ);
6367 Set_Entity_With_Style_Check (S, Comp1);
6370 -- Resolve prefix with its type
6375 -- Generate cross-reference. We needed to wait until full overloading
6376 -- resolution was complete to do this, since otherwise we can't tell if
6377 -- we are an Lvalue of not.
6379 if May_Be_Lvalue (N) then
6380 Generate_Reference (Entity (S), S, 'm');
6382 Generate_Reference (Entity (S), S, 'r');
6385 -- If prefix is an access type, the node will be transformed into an
6386 -- explicit dereference during expansion. The type of the node is the
6387 -- designated type of that of the prefix.
6389 if Is_Access_Type (Etype (P)) then
6390 T := Designated_Type (Etype (P));
6391 Check_Fully_Declared_Prefix (T, P);
6396 if Has_Discriminants (T)
6397 and then (Ekind (Entity (S)) = E_Component
6399 Ekind (Entity (S)) = E_Discriminant)
6400 and then Present (Original_Record_Component (Entity (S)))
6401 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
6402 and then Present (Discriminant_Checking_Func
6403 (Original_Record_Component (Entity (S))))
6404 and then not Discriminant_Checks_Suppressed (T)
6405 and then not Init_Component
6407 Set_Do_Discriminant_Check (N);
6410 if Ekind (Entity (S)) = E_Void then
6411 Error_Msg_N ("premature use of component", S);
6414 -- If the prefix is a record conversion, this may be a renamed
6415 -- discriminant whose bounds differ from those of the original
6416 -- one, so we must ensure that a range check is performed.
6418 if Nkind (P) = N_Type_Conversion
6419 and then Ekind (Entity (S)) = E_Discriminant
6420 and then Is_Discrete_Type (Typ)
6422 Set_Etype (N, Base_Type (Typ));
6425 -- Note: No Eval processing is required, because the prefix is of a
6426 -- record type, or protected type, and neither can possibly be static.
6428 end Resolve_Selected_Component;
6434 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
6435 B_Typ : constant Entity_Id := Base_Type (Typ);
6436 L : constant Node_Id := Left_Opnd (N);
6437 R : constant Node_Id := Right_Opnd (N);
6440 -- We do the resolution using the base type, because intermediate values
6441 -- in expressions always are of the base type, not a subtype of it.
6444 Resolve (R, Standard_Natural);
6446 Check_Unset_Reference (L);
6447 Check_Unset_Reference (R);
6449 Set_Etype (N, B_Typ);
6450 Generate_Operator_Reference (N, B_Typ);
6454 ---------------------------
6455 -- Resolve_Short_Circuit --
6456 ---------------------------
6458 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
6459 B_Typ : constant Entity_Id := Base_Type (Typ);
6460 L : constant Node_Id := Left_Opnd (N);
6461 R : constant Node_Id := Right_Opnd (N);
6467 Check_Unset_Reference (L);
6468 Check_Unset_Reference (R);
6470 Set_Etype (N, B_Typ);
6471 Eval_Short_Circuit (N);
6472 end Resolve_Short_Circuit;
6478 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
6479 Name : constant Node_Id := Prefix (N);
6480 Drange : constant Node_Id := Discrete_Range (N);
6481 Array_Type : Entity_Id := Empty;
6485 if Is_Overloaded (Name) then
6487 -- Use the context type to select the prefix that yields the
6488 -- correct array type.
6492 I1 : Interp_Index := 0;
6494 P : constant Node_Id := Prefix (N);
6495 Found : Boolean := False;
6498 Get_First_Interp (P, I, It);
6499 while Present (It.Typ) loop
6500 if (Is_Array_Type (It.Typ)
6501 and then Covers (Typ, It.Typ))
6502 or else (Is_Access_Type (It.Typ)
6503 and then Is_Array_Type (Designated_Type (It.Typ))
6504 and then Covers (Typ, Designated_Type (It.Typ)))
6507 It := Disambiguate (P, I1, I, Any_Type);
6509 if It = No_Interp then
6510 Error_Msg_N ("ambiguous prefix for slicing", N);
6515 Array_Type := It.Typ;
6520 Array_Type := It.Typ;
6525 Get_Next_Interp (I, It);
6530 Array_Type := Etype (Name);
6533 Resolve (Name, Array_Type);
6535 if Is_Access_Type (Array_Type) then
6536 Apply_Access_Check (N);
6537 Array_Type := Designated_Type (Array_Type);
6539 -- If the prefix is an access to an unconstrained array, we must use
6540 -- the actual subtype of the object to perform the index checks. The
6541 -- object denoted by the prefix is implicit in the node, so we build
6542 -- an explicit representation for it in order to compute the actual
6545 if not Is_Constrained (Array_Type) then
6546 Remove_Side_Effects (Prefix (N));
6549 Obj : constant Node_Id :=
6550 Make_Explicit_Dereference (Sloc (N),
6551 Prefix => New_Copy_Tree (Prefix (N)));
6553 Set_Etype (Obj, Array_Type);
6554 Set_Parent (Obj, Parent (N));
6555 Array_Type := Get_Actual_Subtype (Obj);
6559 elsif Is_Entity_Name (Name)
6560 or else (Nkind (Name) = N_Function_Call
6561 and then not Is_Constrained (Etype (Name)))
6563 Array_Type := Get_Actual_Subtype (Name);
6566 -- If name was overloaded, set slice type correctly now
6568 Set_Etype (N, Array_Type);
6570 -- If the range is specified by a subtype mark, no resolution is
6571 -- necessary. Else resolve the bounds, and apply needed checks.
6573 if not Is_Entity_Name (Drange) then
6574 Index := First_Index (Array_Type);
6575 Resolve (Drange, Base_Type (Etype (Index)));
6577 if Nkind (Drange) = N_Range
6579 -- Do not apply the range check to nodes associated with the
6580 -- frontend expansion of the dispatch table. We first check
6581 -- if Ada.Tags is already loaded to void the addition of an
6582 -- undesired dependence on such run-time unit.
6585 (RTU_Loaded (Ada_Tags)
6586 and then Nkind (Prefix (N)) = N_Selected_Component
6587 and then Present (Entity (Selector_Name (Prefix (N))))
6588 and then Entity (Selector_Name (Prefix (N)))
6589 = RTE_Record_Component (RE_Prims_Ptr))
6591 Apply_Range_Check (Drange, Etype (Index));
6595 Set_Slice_Subtype (N);
6597 if Nkind (Drange) = N_Range then
6598 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
6599 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
6605 ----------------------------
6606 -- Resolve_String_Literal --
6607 ----------------------------
6609 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
6610 C_Typ : constant Entity_Id := Component_Type (Typ);
6611 R_Typ : constant Entity_Id := Root_Type (C_Typ);
6612 Loc : constant Source_Ptr := Sloc (N);
6613 Str : constant String_Id := Strval (N);
6614 Strlen : constant Nat := String_Length (Str);
6615 Subtype_Id : Entity_Id;
6616 Need_Check : Boolean;
6619 -- For a string appearing in a concatenation, defer creation of the
6620 -- string_literal_subtype until the end of the resolution of the
6621 -- concatenation, because the literal may be constant-folded away. This
6622 -- is a useful optimization for long concatenation expressions.
6624 -- If the string is an aggregate built for a single character (which
6625 -- happens in a non-static context) or a is null string to which special
6626 -- checks may apply, we build the subtype. Wide strings must also get a
6627 -- string subtype if they come from a one character aggregate. Strings
6628 -- generated by attributes might be static, but it is often hard to
6629 -- determine whether the enclosing context is static, so we generate
6630 -- subtypes for them as well, thus losing some rarer optimizations ???
6631 -- Same for strings that come from a static conversion.
6634 (Strlen = 0 and then Typ /= Standard_String)
6635 or else Nkind (Parent (N)) /= N_Op_Concat
6636 or else (N /= Left_Opnd (Parent (N))
6637 and then N /= Right_Opnd (Parent (N)))
6638 or else ((Typ = Standard_Wide_String
6639 or else Typ = Standard_Wide_Wide_String)
6640 and then Nkind (Original_Node (N)) /= N_String_Literal);
6642 -- If the resolving type is itself a string literal subtype, we
6643 -- can just reuse it, since there is no point in creating another.
6645 if Ekind (Typ) = E_String_Literal_Subtype then
6648 elsif Nkind (Parent (N)) = N_Op_Concat
6649 and then not Need_Check
6650 and then Nkind (Original_Node (N)) /= N_Character_Literal
6651 and then Nkind (Original_Node (N)) /= N_Attribute_Reference
6652 and then Nkind (Original_Node (N)) /= N_Qualified_Expression
6653 and then Nkind (Original_Node (N)) /= N_Type_Conversion
6657 -- Otherwise we must create a string literal subtype. Note that the
6658 -- whole idea of string literal subtypes is simply to avoid the need
6659 -- for building a full fledged array subtype for each literal.
6661 Set_String_Literal_Subtype (N, Typ);
6662 Subtype_Id := Etype (N);
6665 if Nkind (Parent (N)) /= N_Op_Concat
6668 Set_Etype (N, Subtype_Id);
6669 Eval_String_Literal (N);
6672 if Is_Limited_Composite (Typ)
6673 or else Is_Private_Composite (Typ)
6675 Error_Msg_N ("string literal not available for private array", N);
6676 Set_Etype (N, Any_Type);
6680 -- The validity of a null string has been checked in the
6681 -- call to Eval_String_Literal.
6686 -- Always accept string literal with component type Any_Character, which
6687 -- occurs in error situations and in comparisons of literals, both of
6688 -- which should accept all literals.
6690 elsif R_Typ = Any_Character then
6693 -- If the type is bit-packed, then we always tranform the string literal
6694 -- into a full fledged aggregate.
6696 elsif Is_Bit_Packed_Array (Typ) then
6699 -- Deal with cases of Wide_Wide_String, Wide_String, and String
6702 -- For Standard.Wide_Wide_String, or any other type whose component
6703 -- type is Standard.Wide_Wide_Character, we know that all the
6704 -- characters in the string must be acceptable, since the parser
6705 -- accepted the characters as valid character literals.
6707 if R_Typ = Standard_Wide_Wide_Character then
6710 -- For the case of Standard.String, or any other type whose component
6711 -- type is Standard.Character, we must make sure that there are no
6712 -- wide characters in the string, i.e. that it is entirely composed
6713 -- of characters in range of type Character.
6715 -- If the string literal is the result of a static concatenation, the
6716 -- test has already been performed on the components, and need not be
6719 elsif R_Typ = Standard_Character
6720 and then Nkind (Original_Node (N)) /= N_Op_Concat
6722 for J in 1 .. Strlen loop
6723 if not In_Character_Range (Get_String_Char (Str, J)) then
6725 -- If we are out of range, post error. This is one of the
6726 -- very few places that we place the flag in the middle of
6727 -- a token, right under the offending wide character.
6730 ("literal out of range of type Standard.Character",
6731 Source_Ptr (Int (Loc) + J));
6736 -- For the case of Standard.Wide_String, or any other type whose
6737 -- component type is Standard.Wide_Character, we must make sure that
6738 -- there are no wide characters in the string, i.e. that it is
6739 -- entirely composed of characters in range of type Wide_Character.
6741 -- If the string literal is the result of a static concatenation,
6742 -- the test has already been performed on the components, and need
6745 elsif R_Typ = Standard_Wide_Character
6746 and then Nkind (Original_Node (N)) /= N_Op_Concat
6748 for J in 1 .. Strlen loop
6749 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
6751 -- If we are out of range, post error. This is one of the
6752 -- very few places that we place the flag in the middle of
6753 -- a token, right under the offending wide character.
6755 -- This is not quite right, because characters in general
6756 -- will take more than one character position ???
6759 ("literal out of range of type Standard.Wide_Character",
6760 Source_Ptr (Int (Loc) + J));
6765 -- If the root type is not a standard character, then we will convert
6766 -- the string into an aggregate and will let the aggregate code do
6767 -- the checking. Standard Wide_Wide_Character is also OK here.
6773 -- See if the component type of the array corresponding to the string
6774 -- has compile time known bounds. If yes we can directly check
6775 -- whether the evaluation of the string will raise constraint error.
6776 -- Otherwise we need to transform the string literal into the
6777 -- corresponding character aggregate and let the aggregate
6778 -- code do the checking.
6780 if R_Typ = Standard_Character
6781 or else R_Typ = Standard_Wide_Character
6782 or else R_Typ = Standard_Wide_Wide_Character
6784 -- Check for the case of full range, where we are definitely OK
6786 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
6790 -- Here the range is not the complete base type range, so check
6793 Comp_Typ_Lo : constant Node_Id :=
6794 Type_Low_Bound (Component_Type (Typ));
6795 Comp_Typ_Hi : constant Node_Id :=
6796 Type_High_Bound (Component_Type (Typ));
6801 if Compile_Time_Known_Value (Comp_Typ_Lo)
6802 and then Compile_Time_Known_Value (Comp_Typ_Hi)
6804 for J in 1 .. Strlen loop
6805 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
6807 if Char_Val < Expr_Value (Comp_Typ_Lo)
6808 or else Char_Val > Expr_Value (Comp_Typ_Hi)
6810 Apply_Compile_Time_Constraint_Error
6811 (N, "character out of range?", CE_Range_Check_Failed,
6812 Loc => Source_Ptr (Int (Loc) + J));
6822 -- If we got here we meed to transform the string literal into the
6823 -- equivalent qualified positional array aggregate. This is rather
6824 -- heavy artillery for this situation, but it is hard work to avoid.
6827 Lits : constant List_Id := New_List;
6828 P : Source_Ptr := Loc + 1;
6832 -- Build the character literals, we give them source locations that
6833 -- correspond to the string positions, which is a bit tricky given
6834 -- the possible presence of wide character escape sequences.
6836 for J in 1 .. Strlen loop
6837 C := Get_String_Char (Str, J);
6838 Set_Character_Literal_Name (C);
6841 Make_Character_Literal (P,
6843 Char_Literal_Value => UI_From_CC (C)));
6845 if In_Character_Range (C) then
6848 -- Should we have a call to Skip_Wide here ???
6856 Make_Qualified_Expression (Loc,
6857 Subtype_Mark => New_Reference_To (Typ, Loc),
6859 Make_Aggregate (Loc, Expressions => Lits)));
6861 Analyze_And_Resolve (N, Typ);
6863 end Resolve_String_Literal;
6865 -----------------------------
6866 -- Resolve_Subprogram_Info --
6867 -----------------------------
6869 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
6872 end Resolve_Subprogram_Info;
6874 -----------------------------
6875 -- Resolve_Type_Conversion --
6876 -----------------------------
6878 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
6879 Conv_OK : constant Boolean := Conversion_OK (N);
6880 Target_Type : Entity_Id := Etype (N);
6882 Opnd_Type : Entity_Id;
6888 Operand := Expression (N);
6891 and then not Valid_Conversion (N, Target_Type, Operand)
6896 if Etype (Operand) = Any_Fixed then
6898 -- Mixed-mode operation involving a literal. Context must be a fixed
6899 -- type which is applied to the literal subsequently.
6901 if Is_Fixed_Point_Type (Typ) then
6902 Set_Etype (Operand, Universal_Real);
6904 elsif Is_Numeric_Type (Typ)
6905 and then (Nkind (Operand) = N_Op_Multiply
6906 or else Nkind (Operand) = N_Op_Divide)
6907 and then (Etype (Right_Opnd (Operand)) = Universal_Real
6908 or else Etype (Left_Opnd (Operand)) = Universal_Real)
6910 -- Return if expression is ambiguous
6912 if Unique_Fixed_Point_Type (N) = Any_Type then
6915 -- If nothing else, the available fixed type is Duration
6918 Set_Etype (Operand, Standard_Duration);
6921 -- Resolve the real operand with largest available precision
6923 if Etype (Right_Opnd (Operand)) = Universal_Real then
6924 Rop := New_Copy_Tree (Right_Opnd (Operand));
6926 Rop := New_Copy_Tree (Left_Opnd (Operand));
6929 Resolve (Rop, Universal_Real);
6931 -- If the operand is a literal (it could be a non-static and
6932 -- illegal exponentiation) check whether the use of Duration
6933 -- is potentially inaccurate.
6935 if Nkind (Rop) = N_Real_Literal
6936 and then Realval (Rop) /= Ureal_0
6937 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
6940 ("universal real operand can only " &
6941 "be interpreted as Duration?",
6944 ("\precision will be lost in the conversion", Rop);
6947 elsif Is_Numeric_Type (Typ)
6948 and then Nkind (Operand) in N_Op
6949 and then Unique_Fixed_Point_Type (N) /= Any_Type
6951 Set_Etype (Operand, Standard_Duration);
6954 Error_Msg_N ("invalid context for mixed mode operation", N);
6955 Set_Etype (Operand, Any_Type);
6960 Opnd_Type := Etype (Operand);
6963 -- Note: we do the Eval_Type_Conversion call before applying the
6964 -- required checks for a subtype conversion. This is important,
6965 -- since both are prepared under certain circumstances to change
6966 -- the type conversion to a constraint error node, but in the case
6967 -- of Eval_Type_Conversion this may reflect an illegality in the
6968 -- static case, and we would miss the illegality (getting only a
6969 -- warning message), if we applied the type conversion checks first.
6971 Eval_Type_Conversion (N);
6973 -- Even when evaluation is not possible, we may be able to simplify
6974 -- the conversion or its expression. This needs to be done before
6975 -- applying checks, since otherwise the checks may use the original
6976 -- expression and defeat the simplifications. The is specifically
6977 -- the case for elimination of the floating-point Truncation
6978 -- attribute in float-to-int conversions.
6980 Simplify_Type_Conversion (N);
6982 -- If after evaluation, we still have a type conversion, then we
6983 -- may need to apply checks required for a subtype conversion.
6985 -- Skip these type conversion checks if universal fixed operands
6986 -- operands involved, since range checks are handled separately for
6987 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
6989 if Nkind (N) = N_Type_Conversion
6990 and then not Is_Generic_Type (Root_Type (Target_Type))
6991 and then Target_Type /= Universal_Fixed
6992 and then Opnd_Type /= Universal_Fixed
6994 Apply_Type_Conversion_Checks (N);
6997 -- Issue warning for conversion of simple object to its own type
6998 -- We have to test the original nodes, since they may have been
6999 -- rewritten by various optimizations.
7001 Orig_N := Original_Node (N);
7003 if Warn_On_Redundant_Constructs
7004 and then Comes_From_Source (Orig_N)
7005 and then Nkind (Orig_N) = N_Type_Conversion
7006 and then not In_Instance
7008 Orig_N := Original_Node (Expression (Orig_N));
7009 Orig_T := Target_Type;
7011 -- If the node is part of a larger expression, the Target_Type
7012 -- may not be the original type of the node if the context is a
7013 -- condition. Recover original type to see if conversion is needed.
7015 if Is_Boolean_Type (Orig_T)
7016 and then Nkind (Parent (N)) in N_Op
7018 Orig_T := Etype (Parent (N));
7021 if Is_Entity_Name (Orig_N)
7022 and then Etype (Entity (Orig_N)) = Orig_T
7025 ("?useless conversion, & has this type", N, Entity (Orig_N));
7029 -- Ada 2005 (AI-251): Handle conversions to abstract interface types
7030 -- No need to perform any interface conversion if the type of the
7031 -- expression coincides with the target type.
7033 if Ada_Version >= Ada_05
7034 and then Expander_Active
7035 and then Opnd_Type /= Target_Type
7037 if Is_Access_Type (Target_Type) then
7038 Target_Type := Directly_Designated_Type (Target_Type);
7041 if Is_Class_Wide_Type (Target_Type) then
7042 Target_Type := Etype (Target_Type);
7045 if Is_Interface (Target_Type) then
7046 if Is_Access_Type (Opnd_Type) then
7047 Opnd_Type := Directly_Designated_Type (Opnd_Type);
7050 if Is_Class_Wide_Type (Opnd_Type) then
7051 Opnd_Type := Etype (Opnd_Type);
7056 if Ekind (Opnd_Type) = E_Protected_Subtype
7057 or else Ekind (Opnd_Type) = E_Task_Subtype
7059 Opnd_Type := Etype (Opnd_Type);
7062 if not Interface_Present_In_Ancestor
7064 Iface => Target_Type)
7066 -- The static analysis is not enough to know if the interface
7067 -- is implemented or not. Hence we must pass the work to the
7068 -- expander to generate the required code to evaluate the
7069 -- conversion at run-time.
7071 Expand_Interface_Conversion (N, Is_Static => False);
7074 Expand_Interface_Conversion (N);
7077 -- Ada 2005 (AI-251): Conversion from a class-wide interface to a
7080 elsif Is_Class_Wide_Type (Opnd_Type)
7081 and then Is_Interface (Opnd_Type)
7083 Expand_Interface_Conversion (N, Is_Static => False);
7086 end Resolve_Type_Conversion;
7088 ----------------------
7089 -- Resolve_Unary_Op --
7090 ----------------------
7092 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
7093 B_Typ : constant Entity_Id := Base_Type (Typ);
7094 R : constant Node_Id := Right_Opnd (N);
7100 -- Deal with intrincis unary operators
7102 if Comes_From_Source (N)
7103 and then Ekind (Entity (N)) = E_Function
7104 and then Is_Imported (Entity (N))
7105 and then Is_Intrinsic_Subprogram (Entity (N))
7107 Resolve_Intrinsic_Unary_Operator (N, Typ);
7111 -- Deal with universal cases
7113 if Etype (R) = Universal_Integer
7115 Etype (R) = Universal_Real
7117 Check_For_Visible_Operator (N, B_Typ);
7120 Set_Etype (N, B_Typ);
7123 -- Generate warning for expressions like abs (x mod 2)
7125 if Warn_On_Redundant_Constructs
7126 and then Nkind (N) = N_Op_Abs
7128 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
7130 if OK and then Hi >= Lo and then Lo >= 0 then
7132 ("?abs applied to known non-negative value has no effect", N);
7136 -- Deal with reference generation
7138 Check_Unset_Reference (R);
7139 Generate_Operator_Reference (N, B_Typ);
7142 -- Set overflow checking bit. Much cleverer code needed here eventually
7143 -- and perhaps the Resolve routines should be separated for the various
7144 -- arithmetic operations, since they will need different processing ???
7146 if Nkind (N) in N_Op then
7147 if not Overflow_Checks_Suppressed (Etype (N)) then
7148 Enable_Overflow_Check (N);
7152 -- Generate warning for expressions like -5 mod 3 for integers. No
7153 -- need to worry in the floating-point case, since parens do not affect
7154 -- the result so there is no point in giving in a warning.
7157 Norig : constant Node_Id := Original_Node (N);
7166 if Warn_On_Questionable_Missing_Parens
7167 and then Comes_From_Source (Norig)
7168 and then Is_Integer_Type (Typ)
7169 and then Nkind (Norig) = N_Op_Minus
7171 Rorig := Original_Node (Right_Opnd (Norig));
7173 -- We are looking for cases where the right operand is not
7174 -- parenthesized, and is a bianry operator, multiply, divide, or
7175 -- mod. These are the cases where the grouping can affect results.
7177 if Paren_Count (Rorig) = 0
7178 and then (Nkind (Rorig) = N_Op_Mod
7180 Nkind (Rorig) = N_Op_Multiply
7182 Nkind (Rorig) = N_Op_Divide)
7184 -- For mod, we always give the warning, since the value is
7185 -- affected by the parenthesization (e.g. (-5) mod 315 /=
7186 -- (5 mod 315)). But for the other cases, the only concern is
7187 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
7188 -- overflows, but (-2) * 64 does not). So we try to give the
7189 -- message only when overflow is possible.
7191 if Nkind (Rorig) /= N_Op_Mod
7192 and then Compile_Time_Known_Value (R)
7194 Val := Expr_Value (R);
7196 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
7197 HB := Expr_Value (Type_High_Bound (Typ));
7199 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
7202 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
7203 LB := Expr_Value (Type_Low_Bound (Typ));
7205 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
7208 -- Note that the test below is deliberately excluding
7209 -- the largest negative number, since that is a potentially
7210 -- troublesome case (e.g. -2 * x, where the result is the
7211 -- largest negative integer has an overflow with 2 * x).
7213 if Val > LB and then Val <= HB then
7218 -- For the multiplication case, the only case we have to worry
7219 -- about is when (-a)*b is exactly the largest negative number
7220 -- so that -(a*b) can cause overflow. This can only happen if
7221 -- a is a power of 2, and more generally if any operand is a
7222 -- constant that is not a power of 2, then the parentheses
7223 -- cannot affect whether overflow occurs. We only bother to
7224 -- test the left most operand
7226 -- Loop looking at left operands for one that has known value
7229 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
7230 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
7231 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
7233 -- Operand value of 0 or 1 skips warning
7238 -- Otherwise check power of 2, if power of 2, warn, if
7239 -- anything else, skip warning.
7242 while Lval /= 2 loop
7243 if Lval mod 2 = 1 then
7254 -- Keep looking at left operands
7256 Opnd := Left_Opnd (Opnd);
7259 -- For rem or "/" we can only have a problematic situation
7260 -- if the divisor has a value of minus one or one. Otherwise
7261 -- overflow is impossible (divisor > 1) or we have a case of
7262 -- division by zero in any case.
7264 if (Nkind (Rorig) = N_Op_Divide
7266 Nkind (Rorig) = N_Op_Rem)
7267 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
7268 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
7273 -- If we fall through warning should be issued
7276 ("?unary minus expression should be parenthesized here", N);
7280 end Resolve_Unary_Op;
7282 ----------------------------------
7283 -- Resolve_Unchecked_Expression --
7284 ----------------------------------
7286 procedure Resolve_Unchecked_Expression
7291 Resolve (Expression (N), Typ, Suppress => All_Checks);
7293 end Resolve_Unchecked_Expression;
7295 ---------------------------------------
7296 -- Resolve_Unchecked_Type_Conversion --
7297 ---------------------------------------
7299 procedure Resolve_Unchecked_Type_Conversion
7303 pragma Warnings (Off, Typ);
7305 Operand : constant Node_Id := Expression (N);
7306 Opnd_Type : constant Entity_Id := Etype (Operand);
7309 -- Resolve operand using its own type
7311 Resolve (Operand, Opnd_Type);
7312 Eval_Unchecked_Conversion (N);
7314 end Resolve_Unchecked_Type_Conversion;
7316 ------------------------------
7317 -- Rewrite_Operator_As_Call --
7318 ------------------------------
7320 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
7321 Loc : constant Source_Ptr := Sloc (N);
7322 Actuals : constant List_Id := New_List;
7326 if Nkind (N) in N_Binary_Op then
7327 Append (Left_Opnd (N), Actuals);
7330 Append (Right_Opnd (N), Actuals);
7333 Make_Function_Call (Sloc => Loc,
7334 Name => New_Occurrence_Of (Nam, Loc),
7335 Parameter_Associations => Actuals);
7337 Preserve_Comes_From_Source (New_N, N);
7338 Preserve_Comes_From_Source (Name (New_N), N);
7340 Set_Etype (N, Etype (Nam));
7341 end Rewrite_Operator_As_Call;
7343 ------------------------------
7344 -- Rewrite_Renamed_Operator --
7345 ------------------------------
7347 procedure Rewrite_Renamed_Operator
7352 Nam : constant Name_Id := Chars (Op);
7353 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
7357 -- Rewrite the operator node using the real operator, not its
7358 -- renaming. Exclude user-defined intrinsic operations of the same
7359 -- name, which are treated separately and rewritten as calls.
7361 if Ekind (Op) /= E_Function
7362 or else Chars (N) /= Nam
7364 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
7365 Set_Chars (Op_Node, Nam);
7366 Set_Etype (Op_Node, Etype (N));
7367 Set_Entity (Op_Node, Op);
7368 Set_Right_Opnd (Op_Node, Right_Opnd (N));
7370 -- Indicate that both the original entity and its renaming
7371 -- are referenced at this point.
7373 Generate_Reference (Entity (N), N);
7374 Generate_Reference (Op, N);
7377 Set_Left_Opnd (Op_Node, Left_Opnd (N));
7380 Rewrite (N, Op_Node);
7382 -- If the context type is private, add the appropriate conversions
7383 -- so that the operator is applied to the full view. This is done
7384 -- in the routines that resolve intrinsic operators,
7386 if Is_Intrinsic_Subprogram (Op)
7387 and then Is_Private_Type (Typ)
7390 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
7391 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
7392 Resolve_Intrinsic_Operator (N, Typ);
7394 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
7395 Resolve_Intrinsic_Unary_Operator (N, Typ);
7402 elsif Ekind (Op) = E_Function
7403 and then Is_Intrinsic_Subprogram (Op)
7405 -- Operator renames a user-defined operator of the same name. Use
7406 -- the original operator in the node, which is the one that gigi
7410 Set_Is_Overloaded (N, False);
7412 end Rewrite_Renamed_Operator;
7414 -----------------------
7415 -- Set_Slice_Subtype --
7416 -----------------------
7418 -- Build an implicit subtype declaration to represent the type delivered
7419 -- by the slice. This is an abbreviated version of an array subtype. We
7420 -- define an index subtype for the slice, using either the subtype name
7421 -- or the discrete range of the slice. To be consistent with index usage
7422 -- elsewhere, we create a list header to hold the single index. This list
7423 -- is not otherwise attached to the syntax tree.
7425 procedure Set_Slice_Subtype (N : Node_Id) is
7426 Loc : constant Source_Ptr := Sloc (N);
7427 Index_List : constant List_Id := New_List;
7429 Index_Subtype : Entity_Id;
7430 Index_Type : Entity_Id;
7431 Slice_Subtype : Entity_Id;
7432 Drange : constant Node_Id := Discrete_Range (N);
7435 if Is_Entity_Name (Drange) then
7436 Index_Subtype := Entity (Drange);
7439 -- We force the evaluation of a range. This is definitely needed in
7440 -- the renamed case, and seems safer to do unconditionally. Note in
7441 -- any case that since we will create and insert an Itype referring
7442 -- to this range, we must make sure any side effect removal actions
7443 -- are inserted before the Itype definition.
7445 if Nkind (Drange) = N_Range then
7446 Force_Evaluation (Low_Bound (Drange));
7447 Force_Evaluation (High_Bound (Drange));
7450 Index_Type := Base_Type (Etype (Drange));
7452 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
7454 Set_Scalar_Range (Index_Subtype, Drange);
7455 Set_Etype (Index_Subtype, Index_Type);
7456 Set_Size_Info (Index_Subtype, Index_Type);
7457 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
7460 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
7462 Index := New_Occurrence_Of (Index_Subtype, Loc);
7463 Set_Etype (Index, Index_Subtype);
7464 Append (Index, Index_List);
7466 Set_First_Index (Slice_Subtype, Index);
7467 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
7468 Set_Is_Constrained (Slice_Subtype, True);
7469 Init_Size_Align (Slice_Subtype);
7471 Check_Compile_Time_Size (Slice_Subtype);
7473 -- The Etype of the existing Slice node is reset to this slice
7474 -- subtype. Its bounds are obtained from its first index.
7476 Set_Etype (N, Slice_Subtype);
7478 -- In the packed case, this must be immediately frozen
7480 -- Couldn't we always freeze here??? and if we did, then the above
7481 -- call to Check_Compile_Time_Size could be eliminated, which would
7482 -- be nice, because then that routine could be made private to Freeze.
7484 if Is_Packed (Slice_Subtype) and not In_Default_Expression then
7485 Freeze_Itype (Slice_Subtype, N);
7488 end Set_Slice_Subtype;
7490 --------------------------------
7491 -- Set_String_Literal_Subtype --
7492 --------------------------------
7494 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
7495 Loc : constant Source_Ptr := Sloc (N);
7496 Low_Bound : constant Node_Id :=
7497 Type_Low_Bound (Etype (First_Index (Typ)));
7498 Subtype_Id : Entity_Id;
7501 if Nkind (N) /= N_String_Literal then
7505 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
7506 Set_String_Literal_Length (Subtype_Id, UI_From_Int
7507 (String_Length (Strval (N))));
7508 Set_Etype (Subtype_Id, Base_Type (Typ));
7509 Set_Is_Constrained (Subtype_Id);
7510 Set_Etype (N, Subtype_Id);
7512 if Is_OK_Static_Expression (Low_Bound) then
7514 -- The low bound is set from the low bound of the corresponding
7515 -- index type. Note that we do not store the high bound in the
7516 -- string literal subtype, but it can be deduced if necessary
7517 -- from the length and the low bound.
7519 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
7522 Set_String_Literal_Low_Bound
7523 (Subtype_Id, Make_Integer_Literal (Loc, 1));
7524 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
7526 -- Build bona fide subtypes for the string, and wrap it in an
7527 -- unchecked conversion, because the backend expects the
7528 -- String_Literal_Subtype to have a static lower bound.
7531 Index_List : constant List_Id := New_List;
7532 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
7533 High_Bound : constant Node_Id :=
7535 Left_Opnd => New_Copy_Tree (Low_Bound),
7537 Make_Integer_Literal (Loc,
7538 String_Length (Strval (N)) - 1));
7539 Array_Subtype : Entity_Id;
7540 Index_Subtype : Entity_Id;
7546 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
7547 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
7548 Set_Scalar_Range (Index_Subtype, Drange);
7549 Set_Parent (Drange, N);
7550 Analyze_And_Resolve (Drange, Index_Type);
7552 Set_Etype (Index_Subtype, Index_Type);
7553 Set_Size_Info (Index_Subtype, Index_Type);
7554 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
7556 Array_Subtype := Create_Itype (E_Array_Subtype, N);
7558 Index := New_Occurrence_Of (Index_Subtype, Loc);
7559 Set_Etype (Index, Index_Subtype);
7560 Append (Index, Index_List);
7562 Set_First_Index (Array_Subtype, Index);
7563 Set_Etype (Array_Subtype, Base_Type (Typ));
7564 Set_Is_Constrained (Array_Subtype, True);
7565 Init_Size_Align (Array_Subtype);
7568 Make_Unchecked_Type_Conversion (Loc,
7569 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
7570 Expression => Relocate_Node (N)));
7571 Set_Etype (N, Array_Subtype);
7574 end Set_String_Literal_Subtype;
7576 ------------------------------
7577 -- Simplify_Type_Conversion --
7578 ------------------------------
7580 procedure Simplify_Type_Conversion (N : Node_Id) is
7582 if Nkind (N) = N_Type_Conversion then
7584 Operand : constant Node_Id := Expression (N);
7585 Target_Typ : constant Entity_Id := Etype (N);
7586 Opnd_Typ : constant Entity_Id := Etype (Operand);
7589 if Is_Floating_Point_Type (Opnd_Typ)
7591 (Is_Integer_Type (Target_Typ)
7592 or else (Is_Fixed_Point_Type (Target_Typ)
7593 and then Conversion_OK (N)))
7594 and then Nkind (Operand) = N_Attribute_Reference
7595 and then Attribute_Name (Operand) = Name_Truncation
7597 -- Special processing required if the conversion is the expression
7598 -- of a Truncation attribute reference. In this case we replace:
7600 -- ityp (ftyp'Truncation (x))
7606 -- with the Float_Truncate flag set, which is more efficient
7610 Relocate_Node (First (Expressions (Operand))));
7611 Set_Float_Truncate (N, True);
7615 end Simplify_Type_Conversion;
7617 -----------------------------
7618 -- Unique_Fixed_Point_Type --
7619 -----------------------------
7621 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
7622 T1 : Entity_Id := Empty;
7627 procedure Fixed_Point_Error;
7628 -- If true ambiguity, give details
7630 -----------------------
7631 -- Fixed_Point_Error --
7632 -----------------------
7634 procedure Fixed_Point_Error is
7636 Error_Msg_N ("ambiguous universal_fixed_expression", N);
7637 Error_Msg_NE ("\\possible interpretation as}", N, T1);
7638 Error_Msg_NE ("\\possible interpretation as}", N, T2);
7639 end Fixed_Point_Error;
7641 -- Start of processing for Unique_Fixed_Point_Type
7644 -- The operations on Duration are visible, so Duration is always a
7645 -- possible interpretation.
7647 T1 := Standard_Duration;
7649 -- Look for fixed-point types in enclosing scopes
7651 Scop := Current_Scope;
7652 while Scop /= Standard_Standard loop
7653 T2 := First_Entity (Scop);
7654 while Present (T2) loop
7655 if Is_Fixed_Point_Type (T2)
7656 and then Current_Entity (T2) = T2
7657 and then Scope (Base_Type (T2)) = Scop
7659 if Present (T1) then
7670 Scop := Scope (Scop);
7673 -- Look for visible fixed type declarations in the context
7675 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
7676 while Present (Item) loop
7677 if Nkind (Item) = N_With_Clause then
7678 Scop := Entity (Name (Item));
7679 T2 := First_Entity (Scop);
7680 while Present (T2) loop
7681 if Is_Fixed_Point_Type (T2)
7682 and then Scope (Base_Type (T2)) = Scop
7683 and then (Is_Potentially_Use_Visible (T2)
7684 or else In_Use (T2))
7686 if Present (T1) then
7701 if Nkind (N) = N_Real_Literal then
7702 Error_Msg_NE ("real literal interpreted as }?", N, T1);
7705 Error_Msg_NE ("universal_fixed expression interpreted as }?", N, T1);
7709 end Unique_Fixed_Point_Type;
7711 ----------------------
7712 -- Valid_Conversion --
7713 ----------------------
7715 function Valid_Conversion
7718 Operand : Node_Id) return Boolean
7720 Target_Type : constant Entity_Id := Base_Type (Target);
7721 Opnd_Type : Entity_Id := Etype (Operand);
7723 function Conversion_Check
7725 Msg : String) return Boolean;
7726 -- Little routine to post Msg if Valid is False, returns Valid value
7728 function Valid_Tagged_Conversion
7729 (Target_Type : Entity_Id;
7730 Opnd_Type : Entity_Id) return Boolean;
7731 -- Specifically test for validity of tagged conversions
7733 function Valid_Array_Conversion return Boolean;
7734 -- Check index and component conformance, and accessibility levels
7735 -- if the component types are anonymous access types (Ada 2005)
7737 ----------------------
7738 -- Conversion_Check --
7739 ----------------------
7741 function Conversion_Check
7743 Msg : String) return Boolean
7747 Error_Msg_N (Msg, Operand);
7751 end Conversion_Check;
7753 ----------------------------
7754 -- Valid_Array_Conversion --
7755 ----------------------------
7757 function Valid_Array_Conversion return Boolean
7759 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
7760 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
7762 Opnd_Index : Node_Id;
7763 Opnd_Index_Type : Entity_Id;
7765 Target_Comp_Type : constant Entity_Id :=
7766 Component_Type (Target_Type);
7767 Target_Comp_Base : constant Entity_Id :=
7768 Base_Type (Target_Comp_Type);
7770 Target_Index : Node_Id;
7771 Target_Index_Type : Entity_Id;
7774 -- Error if wrong number of dimensions
7777 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
7780 ("incompatible number of dimensions for conversion", Operand);
7783 -- Number of dimensions matches
7786 -- Loop through indexes of the two arrays
7788 Target_Index := First_Index (Target_Type);
7789 Opnd_Index := First_Index (Opnd_Type);
7790 while Present (Target_Index) and then Present (Opnd_Index) loop
7791 Target_Index_Type := Etype (Target_Index);
7792 Opnd_Index_Type := Etype (Opnd_Index);
7794 -- Error if index types are incompatible
7796 if not (Is_Integer_Type (Target_Index_Type)
7797 and then Is_Integer_Type (Opnd_Index_Type))
7798 and then (Root_Type (Target_Index_Type)
7799 /= Root_Type (Opnd_Index_Type))
7802 ("incompatible index types for array conversion",
7807 Next_Index (Target_Index);
7808 Next_Index (Opnd_Index);
7811 -- If component types have same base type, all set
7813 if Target_Comp_Base = Opnd_Comp_Base then
7816 -- Here if base types of components are not the same. The only
7817 -- time this is allowed is if we have anonymous access types.
7819 -- The conversion of arrays of anonymous access types can lead
7820 -- to dangling pointers. AI-392 formalizes the accessibility
7821 -- checks that must be applied to such conversions to prevent
7822 -- out-of-scope references.
7825 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
7827 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
7828 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
7830 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
7832 if Type_Access_Level (Target_Type) <
7833 Type_Access_Level (Opnd_Type)
7835 if In_Instance_Body then
7836 Error_Msg_N ("?source array type " &
7837 "has deeper accessibility level than target", Operand);
7838 Error_Msg_N ("\?Program_Error will be raised at run time",
7841 Make_Raise_Program_Error (Sloc (N),
7842 Reason => PE_Accessibility_Check_Failed));
7843 Set_Etype (N, Target_Type);
7846 -- Conversion not allowed because of accessibility levels
7849 Error_Msg_N ("source array type " &
7850 "has deeper accessibility level than target", Operand);
7857 -- All other cases where component base types do not match
7861 ("incompatible component types for array conversion",
7866 -- Check that component subtypes statically match
7868 if Is_Constrained (Target_Comp_Type) /=
7869 Is_Constrained (Opnd_Comp_Type)
7870 or else not Subtypes_Statically_Match
7871 (Target_Comp_Type, Opnd_Comp_Type)
7874 ("component subtypes must statically match", Operand);
7880 end Valid_Array_Conversion;
7882 -----------------------------
7883 -- Valid_Tagged_Conversion --
7884 -----------------------------
7886 function Valid_Tagged_Conversion
7887 (Target_Type : Entity_Id;
7888 Opnd_Type : Entity_Id) return Boolean
7891 -- Upward conversions are allowed (RM 4.6(22))
7893 if Covers (Target_Type, Opnd_Type)
7894 or else Is_Ancestor (Target_Type, Opnd_Type)
7898 -- Downward conversion are allowed if the operand is class-wide
7901 elsif Is_Class_Wide_Type (Opnd_Type)
7902 and then Covers (Opnd_Type, Target_Type)
7906 elsif Covers (Opnd_Type, Target_Type)
7907 or else Is_Ancestor (Opnd_Type, Target_Type)
7910 Conversion_Check (False,
7911 "downward conversion of tagged objects not allowed");
7913 -- Ada 2005 (AI-251): The conversion to/from interface types is
7916 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
7919 elsif Is_Access_Type (Opnd_Type)
7920 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
7926 ("invalid tagged conversion, not compatible with}",
7927 N, First_Subtype (Opnd_Type));
7930 end Valid_Tagged_Conversion;
7932 -- Start of processing for Valid_Conversion
7935 Check_Parameterless_Call (Operand);
7937 if Is_Overloaded (Operand) then
7946 -- Remove procedure calls, which syntactically cannot appear
7947 -- in this context, but which cannot be removed by type checking,
7948 -- because the context does not impose a type.
7950 -- When compiling for VMS, spurious ambiguities can be produced
7951 -- when arithmetic operations have a literal operand and return
7952 -- System.Address or a descendant of it. These ambiguities are
7953 -- otherwise resolved by the context, but for conversions there
7954 -- is no context type and the removal of the spurious operations
7955 -- must be done explicitly here.
7957 -- The node may be labelled overloaded, but still contain only
7958 -- one interpretation because others were discarded in previous
7959 -- filters. If this is the case, retain the single interpretation
7962 Get_First_Interp (Operand, I, It);
7963 Opnd_Type := It.Typ;
7964 Get_Next_Interp (I, It);
7967 and then Opnd_Type /= Standard_Void_Type
7969 -- More than one candidate interpretation is available
7971 Get_First_Interp (Operand, I, It);
7972 while Present (It.Typ) loop
7973 if It.Typ = Standard_Void_Type then
7977 if Present (System_Aux_Id)
7978 and then Is_Descendent_Of_Address (It.Typ)
7983 Get_Next_Interp (I, It);
7987 Get_First_Interp (Operand, I, It);
7992 Error_Msg_N ("illegal operand in conversion", Operand);
7996 Get_Next_Interp (I, It);
7998 if Present (It.Typ) then
8000 It1 := Disambiguate (Operand, I1, I, Any_Type);
8002 if It1 = No_Interp then
8003 Error_Msg_N ("ambiguous operand in conversion", Operand);
8005 Error_Msg_Sloc := Sloc (It.Nam);
8006 Error_Msg_N ("\\possible interpretation#!", Operand);
8008 Error_Msg_Sloc := Sloc (N1);
8009 Error_Msg_N ("\\possible interpretation#!", Operand);
8015 Set_Etype (Operand, It1.Typ);
8016 Opnd_Type := It1.Typ;
8022 if Is_Numeric_Type (Target_Type) then
8024 -- A universal fixed expression can be converted to any numeric type
8026 if Opnd_Type = Universal_Fixed then
8029 -- Also no need to check when in an instance or inlined body, because
8030 -- the legality has been established when the template was analyzed.
8031 -- Furthermore, numeric conversions may occur where only a private
8032 -- view of the operand type is visible at the instanciation point.
8033 -- This results in a spurious error if we check that the operand type
8034 -- is a numeric type.
8036 -- Note: in a previous version of this unit, the following tests were
8037 -- applied only for generated code (Comes_From_Source set to False),
8038 -- but in fact the test is required for source code as well, since
8039 -- this situation can arise in source code.
8041 elsif In_Instance or else In_Inlined_Body then
8044 -- Otherwise we need the conversion check
8047 return Conversion_Check
8048 (Is_Numeric_Type (Opnd_Type),
8049 "illegal operand for numeric conversion");
8054 elsif Is_Array_Type (Target_Type) then
8055 if not Is_Array_Type (Opnd_Type)
8056 or else Opnd_Type = Any_Composite
8057 or else Opnd_Type = Any_String
8060 ("illegal operand for array conversion", Operand);
8063 return Valid_Array_Conversion;
8066 -- Anonymous access types where target references an interface
8068 elsif (Ekind (Target_Type) = E_General_Access_Type
8070 Ekind (Target_Type) = E_Anonymous_Access_Type)
8071 and then Is_Interface (Directly_Designated_Type (Target_Type))
8073 -- Check the static accessibility rule of 4.6(17). Note that the
8074 -- check is not enforced when within an instance body, since the RM
8075 -- requires such cases to be caught at run time.
8077 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
8078 if Type_Access_Level (Opnd_Type) >
8079 Type_Access_Level (Target_Type)
8081 -- In an instance, this is a run-time check, but one we know
8082 -- will fail, so generate an appropriate warning. The raise
8083 -- will be generated by Expand_N_Type_Conversion.
8085 if In_Instance_Body then
8087 ("?cannot convert local pointer to non-local access type",
8090 ("\?Program_Error will be raised at run time", Operand);
8093 ("cannot convert local pointer to non-local access type",
8098 -- Special accessibility checks are needed in the case of access
8099 -- discriminants declared for a limited type.
8101 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
8102 and then not Is_Local_Anonymous_Access (Opnd_Type)
8104 -- When the operand is a selected access discriminant the check
8105 -- needs to be made against the level of the object denoted by
8106 -- the prefix of the selected name. (Object_Access_Level
8107 -- handles checking the prefix of the operand for this case.)
8109 if Nkind (Operand) = N_Selected_Component
8110 and then Object_Access_Level (Operand) >
8111 Type_Access_Level (Target_Type)
8113 -- In an instance, this is a run-time check, but one we
8114 -- know will fail, so generate an appropriate warning.
8115 -- The raise will be generated by Expand_N_Type_Conversion.
8117 if In_Instance_Body then
8119 ("?cannot convert access discriminant to non-local" &
8120 " access type", Operand);
8122 ("\?Program_Error will be raised at run time", Operand);
8125 ("cannot convert access discriminant to non-local" &
8126 " access type", Operand);
8131 -- The case of a reference to an access discriminant from
8132 -- within a limited type declaration (which will appear as
8133 -- a discriminal) is always illegal because the level of the
8134 -- discriminant is considered to be deeper than any (namable)
8137 if Is_Entity_Name (Operand)
8138 and then not Is_Local_Anonymous_Access (Opnd_Type)
8139 and then (Ekind (Entity (Operand)) = E_In_Parameter
8140 or else Ekind (Entity (Operand)) = E_Constant)
8141 and then Present (Discriminal_Link (Entity (Operand)))
8144 ("discriminant has deeper accessibility level than target",
8153 -- General and anonymous access types
8155 elsif (Ekind (Target_Type) = E_General_Access_Type
8156 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
8159 (Is_Access_Type (Opnd_Type)
8160 and then Ekind (Opnd_Type) /=
8161 E_Access_Subprogram_Type
8162 and then Ekind (Opnd_Type) /=
8163 E_Access_Protected_Subprogram_Type,
8164 "must be an access-to-object type")
8166 if Is_Access_Constant (Opnd_Type)
8167 and then not Is_Access_Constant (Target_Type)
8170 ("access-to-constant operand type not allowed", Operand);
8174 -- Check the static accessibility rule of 4.6(17). Note that the
8175 -- check is not enforced when within an instance body, since the RM
8176 -- requires such cases to be caught at run time.
8178 if Ekind (Target_Type) /= E_Anonymous_Access_Type
8179 or else Is_Local_Anonymous_Access (Target_Type)
8181 if Type_Access_Level (Opnd_Type)
8182 > Type_Access_Level (Target_Type)
8184 -- In an instance, this is a run-time check, but one we
8185 -- know will fail, so generate an appropriate warning.
8186 -- The raise will be generated by Expand_N_Type_Conversion.
8188 if In_Instance_Body then
8190 ("?cannot convert local pointer to non-local access type",
8193 ("\?Program_Error will be raised at run time", Operand);
8197 ("cannot convert local pointer to non-local access type",
8202 -- Special accessibility checks are needed in the case of access
8203 -- discriminants declared for a limited type.
8205 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
8206 and then not Is_Local_Anonymous_Access (Opnd_Type)
8209 -- When the operand is a selected access discriminant the check
8210 -- needs to be made against the level of the object denoted by
8211 -- the prefix of the selected name. (Object_Access_Level
8212 -- handles checking the prefix of the operand for this case.)
8214 if Nkind (Operand) = N_Selected_Component
8215 and then Object_Access_Level (Operand)
8216 > Type_Access_Level (Target_Type)
8218 -- In an instance, this is a run-time check, but one we
8219 -- know will fail, so generate an appropriate warning.
8220 -- The raise will be generated by Expand_N_Type_Conversion.
8222 if In_Instance_Body then
8224 ("?cannot convert access discriminant to non-local" &
8225 " access type", Operand);
8227 ("\?Program_Error will be raised at run time",
8232 ("cannot convert access discriminant to non-local" &
8233 " access type", Operand);
8238 -- The case of a reference to an access discriminant from
8239 -- within a limited type declaration (which will appear as
8240 -- a discriminal) is always illegal because the level of the
8241 -- discriminant is considered to be deeper than any (namable)
8244 if Is_Entity_Name (Operand)
8245 and then (Ekind (Entity (Operand)) = E_In_Parameter
8246 or else Ekind (Entity (Operand)) = E_Constant)
8247 and then Present (Discriminal_Link (Entity (Operand)))
8250 ("discriminant has deeper accessibility level than target",
8258 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
8259 -- Helper function to handle limited views
8261 --------------------------
8262 -- Full_Designated_Type --
8263 --------------------------
8265 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
8266 Desig : constant Entity_Id := Designated_Type (T);
8268 if From_With_Type (Desig)
8269 and then Is_Incomplete_Type (Desig)
8270 and then Present (Non_Limited_View (Desig))
8272 return Non_Limited_View (Desig);
8276 end Full_Designated_Type;
8278 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
8279 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
8281 Same_Base : constant Boolean :=
8282 Base_Type (Target) = Base_Type (Opnd);
8285 if Is_Tagged_Type (Target) then
8286 return Valid_Tagged_Conversion (Target, Opnd);
8289 if not Same_Base then
8291 ("target designated type not compatible with }",
8292 N, Base_Type (Opnd));
8295 -- Ada 2005 AI-384: legality rule is symmetric in both
8296 -- designated types. The conversion is legal (with possible
8297 -- constraint check) if either designated type is
8300 elsif Subtypes_Statically_Match (Target, Opnd)
8302 (Has_Discriminants (Target)
8304 (not Is_Constrained (Opnd)
8305 or else not Is_Constrained (Target)))
8311 ("target designated subtype not compatible with }",
8318 -- Subprogram access types
8320 elsif (Ekind (Target_Type) = E_Access_Subprogram_Type
8322 Ekind (Target_Type) = E_Anonymous_Access_Subprogram_Type)
8323 and then No (Corresponding_Remote_Type (Opnd_Type))
8326 Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
8329 ("illegal attempt to store anonymous access to subprogram",
8332 ("\value has deeper accessibility than any master " &
8333 "('R'M 3.10.2 (13))",
8336 if Is_Entity_Name (Operand)
8337 and then Ekind (Entity (Operand)) = E_In_Parameter
8340 ("\use named access type for& instead of access parameter",
8341 Operand, Entity (Operand));
8345 -- Check that the designated types are subtype conformant
8347 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
8348 Old_Id => Designated_Type (Opnd_Type),
8351 -- Check the static accessibility rule of 4.6(20)
8353 if Type_Access_Level (Opnd_Type) >
8354 Type_Access_Level (Target_Type)
8357 ("operand type has deeper accessibility level than target",
8360 -- Check that if the operand type is declared in a generic body,
8361 -- then the target type must be declared within that same body
8362 -- (enforces last sentence of 4.6(20)).
8364 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
8366 O_Gen : constant Node_Id :=
8367 Enclosing_Generic_Body (Opnd_Type);
8372 T_Gen := Enclosing_Generic_Body (Target_Type);
8373 while Present (T_Gen) and then T_Gen /= O_Gen loop
8374 T_Gen := Enclosing_Generic_Body (T_Gen);
8377 if T_Gen /= O_Gen then
8379 ("target type must be declared in same generic body"
8380 & " as operand type", N);
8387 -- Remote subprogram access types
8389 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
8390 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
8392 -- It is valid to convert from one RAS type to another provided
8393 -- that their specification statically match.
8395 Check_Subtype_Conformant
8397 Designated_Type (Corresponding_Remote_Type (Target_Type)),
8399 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
8406 elsif Is_Tagged_Type (Target_Type) then
8407 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
8409 -- Types derived from the same root type are convertible
8411 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
8414 -- In an instance, there may be inconsistent views of the same
8415 -- type, or types derived from the same type.
8418 and then Underlying_Type (Target_Type) = Underlying_Type (Opnd_Type)
8422 -- Special check for common access type error case
8424 elsif Ekind (Target_Type) = E_Access_Type
8425 and then Is_Access_Type (Opnd_Type)
8427 Error_Msg_N ("target type must be general access type!", N);
8428 Error_Msg_NE ("add ALL to }!", N, Target_Type);
8433 Error_Msg_NE ("invalid conversion, not compatible with }",
8438 end Valid_Conversion;
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